CA2124133A1 - (meth)acrylate system for conductive floor coatings and a process for the preparation of conductive floor coatings - Google Patents
(meth)acrylate system for conductive floor coatings and a process for the preparation of conductive floor coatingsInfo
- Publication number
- CA2124133A1 CA2124133A1 CA002124133A CA2124133A CA2124133A1 CA 2124133 A1 CA2124133 A1 CA 2124133A1 CA 002124133 A CA002124133 A CA 002124133A CA 2124133 A CA2124133 A CA 2124133A CA 2124133 A1 CA2124133 A1 CA 2124133A1
- Authority
- CA
- Canada
- Prior art keywords
- meth
- acrylate
- conductive
- fillers
- sum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
- C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
- C08F20/10—Esters
- C08F20/12—Esters of monohydric alcohols or phenols
- C08F20/14—Methyl esters, e.g. methyl (meth)acrylate
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/24—Electrically-conducting paints
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/923—Physical dimension
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/923—Physical dimension
- Y10S428/924—Composite
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/923—Physical dimension
- Y10S428/924—Composite
- Y10S428/925—Relative dimension specified
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/923—Physical dimension
- Y10S428/924—Composite
- Y10S428/926—Thickness of individual layer specified
Abstract
ABSTRACT OF THE DISCLOSURE
Electrically conductive floor coatings could not be carried out hitherto on a (meth)acrylate basis since the conductive fillers used such as carbon black, graphite or surface-treated metal powder prevented curing. According to the invention, therefore, a polymerizable (meth)acrylate system is provided which can be cured at ambient temperatures by a redox system and fulfills the requirements in respect of conductive floor coverings. (Meth)acrylates which can be used for coating, optionally containing other components such as prepolymers, plasticizers, customary additives etc., may be cured with amphorous or spheroidal graphite and/or carbon fibres and/or finely divided metal, whereby other fillers may be added. In particular, amorphous natural graphite, preferably having the particular size 20 to 1000 µm, is suitable. The coatings prepared in this way fulfill the requirements in respect of DIN 51 953. Conductive coatings, particularly floor coatings.
Electrically conductive floor coatings could not be carried out hitherto on a (meth)acrylate basis since the conductive fillers used such as carbon black, graphite or surface-treated metal powder prevented curing. According to the invention, therefore, a polymerizable (meth)acrylate system is provided which can be cured at ambient temperatures by a redox system and fulfills the requirements in respect of conductive floor coverings. (Meth)acrylates which can be used for coating, optionally containing other components such as prepolymers, plasticizers, customary additives etc., may be cured with amphorous or spheroidal graphite and/or carbon fibres and/or finely divided metal, whereby other fillers may be added. In particular, amorphous natural graphite, preferably having the particular size 20 to 1000 µm, is suitable. The coatings prepared in this way fulfill the requirements in respect of DIN 51 953. Conductive coatings, particularly floor coatings.
Description
- 212~133 The invention relates to a polymerizable, cold-setting, reactive (meth)acrylate system for conductive floor coatings and to the preparation of said coatings.
Filled methacrylate systems already belong to the prior art.
The use of mixtures based on monomeric esters of methacrylic acid and fillers as casting compound for the preparation of optionally glass fibre reinforced moulded bodies and profiles is known from DE-OS-20 28 890. The mixture according to DE-OS-20 28 890 comprises essentially a) approx. 5 to approx.
50% by wt. of monomeric esters of methacrylic acid with mono-and/or polyhydric alcohols, wherein optionally up to approx.
20% by wt. of the methacrylic acid esters may be replaced by other, polymerizable vinyl or allyl compounds, and b) approx.
95 to approx. 50% by wt. of one or more inorganic or organic solids which are insoluble in the monomer or in the monomer mixture, and may in addition contain minor quantities of dyes or pigments and, if necessary, polymerization accelerators, and the mixture is cured, preferably with the action of inherently known polymerization catalysts. DE-OS-20 28 890 proposes metal powder, inter alia, as fillers, for example, the use of finely divided iron powder or aluminum powder is described.
The well known casting compound is not very suitable as a -floor coating because of the low monomer proportion and the high filler content.
1 -~
~ . ~
Filled methacrylate systems already belong to the prior art.
The use of mixtures based on monomeric esters of methacrylic acid and fillers as casting compound for the preparation of optionally glass fibre reinforced moulded bodies and profiles is known from DE-OS-20 28 890. The mixture according to DE-OS-20 28 890 comprises essentially a) approx. 5 to approx.
50% by wt. of monomeric esters of methacrylic acid with mono-and/or polyhydric alcohols, wherein optionally up to approx.
20% by wt. of the methacrylic acid esters may be replaced by other, polymerizable vinyl or allyl compounds, and b) approx.
95 to approx. 50% by wt. of one or more inorganic or organic solids which are insoluble in the monomer or in the monomer mixture, and may in addition contain minor quantities of dyes or pigments and, if necessary, polymerization accelerators, and the mixture is cured, preferably with the action of inherently known polymerization catalysts. DE-OS-20 28 890 proposes metal powder, inter alia, as fillers, for example, the use of finely divided iron powder or aluminum powder is described.
The well known casting compound is not very suitable as a -floor coating because of the low monomer proportion and the high filler content.
1 -~
~ . ~
2~2L11 ~3 ~ ':
US-3 907 727 discloses the use of carbon black for blacki~g moulded bodies made from cast acrylat~ polymer. According to said patent, a dispersion of furnace black, acrylate polymer, methyl methacrylate monomer and a small proportion of nitrocellulose is prepared in the ~irst instance. A
catalyst is then added to said dispersion. The dispersion is then poured into the mould and heated to at least 50 C.
In view of the addition of nitrocellulose and the relatively high temperature required for polymerisation, said system is also unsuitable as a floor coating.
Filled polymer materials, e.g. mixtures o$ polybutyl methacrylate and CP-butyl acrylate-isobutylene which are filled with Ni powder, Al powder or graphite, are known from DKI, report no. 93040679707, 1993-04779. The Russian publication on which said abstract is based is concerned with the analysis of the elongation diagram of filled polymer materials. No references to floor coatings can be derived from the DKI abstract.
DE-OS 23 09 149 is concerned with polymer compounds in which the surface of a granular, inorganic substance is coated almost completely with a polyrmer material.
Inorganic substances mentioned are iron sesquioxide or carbon, inter alia, whilst monomers listed are methyl methacrylate or acrylic acid methyl ester. In an example, however, only iron sesquioxide particles are coated with - ~-polyvinyl chloride, which is polymerised at a temperature of 65 C. According to DE-OS 23 09 149, a heat-setting methacrylate system is used, whilst the inorganic particles ~
mentioned are provided with a polymer coating in order to ~ ~-produce a better strength during pressing than, ~or :~ -example, dry mixtures of inorganic substances and synthetic resin would exhibit.
,.
. . . ~ - . : : : ~ : , .: :
~12~33 Finally, a process for the polymerization of MMA in the presence of graphite is known from Angewandte Chemie 53 (1976), pages 65-72. Polymerization is carried out in S02_ containing water, a reaction between ash contained in graphite and HS03_ being assumed as an initiating reaction.
The aqueous redox system used in said publication does not seem to be suitable for the preparation of conductive floor coatings.
For some decades, electrically conductive floor coatings have been prepared on the basis of epoxides, polyurethanes or polyesters. In order to achieve conductivity, c~nductive fillers such as carbon black, graphite or surface-treated metal powders are added to the coatings. In case of (meth)acrylate coatings, said additions lead to disturbances in the curing process, however, with the result that corresponding conductive floor coatings based on (meth)acrylate could not be produced.
The preparation of conductive, acrylic (meth)acrylate coatings was, therefore, very expensive. US Patent 4,714,569 describes a coating process in which graphite and carbon black are pre-polymerized in a particular ratio with (meth)acrylic acid and functionalized (meth)acrylates, the mixture is further polymerized with an azo compound at elevated temperature, and the product obtained is cured with a cross-linking agent. Said process is unsuitable for coating large areas, particularly floors, because the required temperatures of between 80 and 90 C over several hours cannot be achieved in this case.
The present invention provides a polymerizable (meth)acrylate system which cures at ambient temperatures by mean~ of a redox system and which fulfills the requirements in respect of conductive coatings.
`` 212~33 More particularly, in one aspect, the invention provides polymerizable, cold-setting, reactive (meth)acrylate system for conductive floor coatings containing A (meth)acrylate >50 - 100% by wt.
methyl(meth)acrylate 0 - lO0~ by wt.
C2 ~ C4 (meth)acrylate 0 - 100% by wt.
2Cs (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100~ by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
,:
C 0 - 7 parts of plasticizer to 10 parts of (A + B) ~ ~
D a redox system to be kept apart from the polymerizable ~- -constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 30 10 - 40% by wt. or - 212'1133 carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of < 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to < 50% by wt.
G other fillers, based on the sum of A - G
0 ~ 92% by wt. where the sum of F + G is limited to < 93% by wt.
and fillers between 20 and 50 ~m are limited to < 30% by wt.
and those below 20 ~m to < 10% by wt.
20 H solvents based on the sum of A - E plus H S 15% by wt.
The polymerizable, cold-setting, reactive (meth)acrylate system according to the invention is composed of the components A to E, which together represent the binder, the conductive fillers F and other fillers G, and a possible proportion of a solvent H.
The binder (A to E) is, in turn, composed of polymerizable monomers A, optionally (pre)polymers B which are soluble or 4a ~24~3~
capable of swelling in said monomers, optionally plasticizer C, a redox system D, and customary additives E.
A single nonomer may be used as monomer A, e.g.
5 methyl(meth)acrylate, but a mixture is normally used. The composition of component A is:
(meth)acrylate>50 - 100% by wt.
methyl(meth)acrylate 0 - 100% by wt.
C2 ~ C4 (neth)acrylate 0 - 100% by wt.
C5 (meth)acrylate0 - S0% by wt.
polyhydric (meth)acrylates 0 - 100% by wt.
comonomers0 - 50% by wt.
vinyl aromatics0 - 30% by wt.
vinyl esters0 - 30% by wt.
Preferably, styrene is limited to max. 20% by wt. in A
because a higher content leads to disturbances during cold setting, and considerable odor problems can be expected. ~
: : ..
A constituent placed in brackets stands for its optional usability, i.e. (meth)acrylate stands for acrylate and/or methacrylate. The monomer component A contains at least > ~-50% by wt. of (meth)acrylate, monohydric (meth)acrylates with a Cl - C4 ester group being preferred. Longer-chain esters, i.e. those with a C5 or longer chain ester are 4b 212~133 limited to 50% by wt. in component A. Said esters make coatings or moulded parts more flexible, but also softer, as a result of which their performance characteristics are restricted. Preferably, polyhydric (meth)acrylates are also contained in component A, whereby component A may also be composed completely of polyhydric (meth)acrylates.
In addition to (meth)acrylates, component A may also contain other comonomers, their proportion being limited to 50% by wt. Of said comonomers, vinyl aromatics and/or vinyl esters may be contained in each case in quantities up to 30~ by wt. in component A. Higher proportions of vinyl aromatics are difficult to incorporate during polymerisation and may lead to demixing of the system.
Moreover, higher proportions of vinyl esters may cure insufficiently at low temperatures and tend to exhibit greater shrinkage.
Preferably, component A is composed of 80 - 100~ by wt. and in particular preference 90 -100~ by wt. of (meth)acrylates, since favourable performance characteristics for coatings or moulded parts may be achieved with said monomers. The proportion of C2 - C4 esters in (meth)acrylates is limited preferably to 50% by wt. in component A, said esters are contained preferably in a quantity of max. 30% by wt. and particularly advantageously in a quantity of max. 20~i by wt. in component A. Similarly, the 2C5 esters of (meth)acrylic acid are limited preferably to 30% by wt. and particularly advantageously to 15% by wt. Particularly flexible and non-soiling coating compounds can thereby be produced.
Suitable monofunctional (meth)acrylates are, in particular, methyl methacrylate, butyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyltriglycol methacrylate,hydoxypropyl methacrylate; in particular ~inyl toluene, styrene, vinyl esters are ~uitable as comonomers.
- ` 2~ 2 ~33 Poly~unctional (meth)acrylates are contained particularly advantageously in component A, their content lying normally in the region of 1 to 50% by wt. and mostly 1 to 10% by wt.
in A. The polyfunctional (meth)acrylates are used for linking polymers between linear molecules. As a result, properties such as flexibility, scratch resistance, melting point or curing processes can be manipulated.
Customary polyfunctional (meth)acrylates are triethylene glycol dimethacrylate (TEDMA), trimethylolpropane trimethacrylate (TRIM), butane-1,4-diol dimethacrylate (1,4-BDMA).
In order to ad~ust the viscosity of the binder and the process characteristics and to achieve better curing, a polymer or prepolymer may be added to component A. Said (pre)polymer should be soluble or capable of swelling in A.
Up to 2 parts of the prepolymer B to one part of A are used. In particular, poly(meth)acrylates are suitable, whereby said materials may be dissolved as solid polymer in A, or whereby a so-called syrup may be used, i.e. partially polymerised masses of corresponding monomers. Moreover, polyvinyl chloride, polyvinyl acetate, polystyrene, epoxy resins, epoxy(meth)acrylates, unsaturated polyesters, polyurethanes or mixtures thereof are suitable. Said polymers bring about in the binder e.g. special flexibility ~-properties, shrinkage control, stabiliser, skin former or process improver.
Thin coatings, i.e. those less than 5 mm, contain preferably at least 1% by wt., particularly advantageously at least 3% by wt. of a high molecular weight polymer, e.g.
poly(meth)acrylate, based on the sum of A + B.
Moreover, the binder normally contains a plasticiser, whereby up to 7 parts of a plasticiser to 10 parts of A + B
may be used. Normally, the plasticiser proportion C in the ~241~3 sum of A to C is 5 - 25~ by wt., and mostly 10 - 20~ by wt.
The plasticiser is used e.g. as an acceptor for peroxide components for the automatic 2-component mixing process (desensitising agent), to control the compressive and flexural strengths and to vary the surface tension.
Suitable plasticisers are e.g. phthalic acid esters, adipic acid esters, chlorinated paraffins, urea resins, melamine resins, modified phenolates, polyglycol urethanes.
The binder (A to E) may further contain customary additives E, of the kind mostly used in reactive (meth)acrylate systems. Said additives are used, e.g. to neutralise oxygen inhibition; in particular, paraffins in a quantity of 0.05 to 5~ by wt. in the binder A to ~ and/or phosphites in a quantity of 0.0~ to lS by wt. in A to E and also a polymer skin foxmation (paraffin-free) are suitable for this purpose. For the latter, in order to achieve a non-inhibited surface without paraffin, e.g. extremely high molecular weight polymers may be used as additive, particularly if methyl methacrylate is used alone. Methyl methacrylate evaporates on the surface even during curing and leaves behind a tack-free surface due to polymer skin formation.
In addition, defoamers, wetting agents, thixotropic agents, inhibitors, dulling agents, blueing agents, W stabilisers, polymerisation chain regulators may be added.
The binder A to E according to the invention is suitable for cold setting, e.g. contains for polymerisation a redox system composed of an accelerator and a peroxide catalyst or initiator, said components being added in sufficient quantity for the cold setting of component A. The accelerator is normally used in a quantity of 0.01 to 5~ by wt. in A to ~, particularly advantageously in a quantity of G.5 to 1.5~ by wt. In particular, amines and mercaptans ~ 2~2~33 are suitable as accelerators, dimethyl-p-toluidine, diisopropoxy-p-toluidine, diethylol-p-toluidine, dimethylaniline and glycol dimercaptoacetate are preferred.
In addition, organic metal salts which are normally used in the region of 0.001 to 2~ by wt. in A to E are used as accelerators. For example, cobalt naphthenate, copper naphthenate, cobalt oleate, copper oleate are suitable.
In particular, dibenzoyl peroxide and methyl ethyl ketone peroxide are suitable as peroxide catalyst. The peroxides are normally used in a quantity of 0.1 to 10% by wt. and in particular in a quantity of 0.5 to 5% by wt. in the binder.
Of the component D, the accelerators e.g.
dimethylparatoluidine may already be contained in the binder without polymerisation taking place at ambient temperature. By adding the remaining constituents of component D, the reaction is initiated, component D
normally being proportioned such that the tmeth)acrylate system has a pot life of 10 min to 20 min. The (meth)acrylate system according to the in~ention contains, therefore, the complete component D only immediately before use; until use, component D is contained only in part or not at all, or in other words, until polymerisation of the polymerisable constituents, the complete operative redox system must be kept apart from said constituents, whereas individual constituents of the redox system may already be premixed with polymerisable substances.
As constituent~ which are important to the invention, the (meth)acrylate system contains component F, one or more fillers, and namely based on the sum of A to F
amsrphous or spheroidal graphite 10 - 40% by wt.
or 35 carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10~ by wt.
~12~13~
or finely divided metal in the form of flakes, powder or granules with a greatest particle length s 5 mm 2 - 40% by wt.
5 or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of the conductive fillers being limited to <50~ by wt.
The amorphous or spheroidal graphite component is normally natural graphite. It is important in this connection that crystalline graphite, normally this is synthetic graphite, is not used. Only graphite whose particles are rounded is suitable ~or the polymerisable, cold-setting, reactive (meth)acrylate system according to the invention. Said graphite particles normally lie in a particle size range of 20 s x s 100 ~m, where x stands for the greatest particle length. The particles are noxmally platelets with highly rounded edges. Mostly, the graphite is used in a quantity of max. 30% by wt. and normally in a quantity of at least 20~ by wt., based on the sum of A to F.
Normally, the commercially obtainable amorphous natural graphite may be used as graphite; in the event of poor polymerisation tslow curing or none at all, tacky surface), the selection from the amorphous natural graphites by X-ray electron microscopy should be made to the effect that the amorphous natural graphite used has particularly rounded edges. In this way, the expert may easily select a suitable graphite. At least 80~ by wt. of the graphite - used should have a greatest particle length of between 20 and 1000 ~m, preferably at least 90~ by wt. h~ve a greatest particle length exceeding 20 ~m. Those graphites in which less than 20~ by wt. are below ~0 ~m and particularly less than 20~ by wt. are below 32 ~m on screening are -` 2~ 133 particularly advantageous. The natural graphites normally have a carbon proportion of >70% by wt. and mostly a correspondingly high ash proportion. The normally mineral accompanying substances in natural graphite are not troublesome, on the contrary, they reduce the inhibiting effect of graphite.
The carbon fibres to be used according to the invention normally have a length in the region of 50 to 2000 ~m and in particular preference in the region of 100 to 1000 ~m.
Depending on the purpose, fibre lengths below 500 ~m are particularly suitable. The proportion of carbon fibres in A to F is particularly advantageously 2 to 5% by wt. and in particular 3 to 4~ by wt. Said ranges are particularly ad~antageous in the case of coatings with (meth)acrylate systems because long carbon fibres readily align themselves vertically in said systems and thus project in a brush-like manner on the surface, on the one hand, and do not achieve the desired conductivity effect, on the other hand. The carbon fibres are used in particular for light-coloured coatings, since a smaller proportion is needed than with graphite. Combinations of carbon fibre and graphite are also particularly advantageous, since inexpensive coatings with good conductivity may be prepared by this means.
Moreover, metal spangles, powders and granules which preferably ha~e a greatest particle length of 5 2 mm may be used in the conductive systems according to the present invention. Said metals in the form of flakes, powder or gra~ules are also used in particular in cases where ligh~-coloured coatings are desired. Normally, the metal fillers are likewise used together with graphite. Copper, aluminium and chromium-nickel steel are suitable as metal fillers.
It is particularly important in the case of metal fillers -~
that they are neither anodised nor pre-treated with fatty . ' ' . ' ~ .
i ~ 2~133 acid or silicone oil since such metal fillers are either incompatible with (meth)acrylic systems or do not lead to the desired conductivity. If the conductive fillers F are used in mixture, smaller quantities of the individual S component F than those stated above may be used, corresponding to the proportion in the sum F, the maximum quantity of conductive fillers is limited to 50% by wt. in the system A to F.
Apart from the conductive fillers F, the systems according to the invention normally contain other fillers, whereby these are limited in the sum of A to G to 0 to 92~ by wt., and the sum of F + G is limited to s 93% by wt., and fillers between 20 and 50 ~m are limited to s 30~ by wt.
and those below 20 ~m to s 10% by wt. The particle size of fillers G is determined by screen analysis and is required for obtaining a sufficient conductivity of the cured (meth)acrylate system. If larger quantities of fillers between 20 and 50 ~m and in particular below 20 ~m than those stated are contained in the sum of A to G, the conductivity of the cured system will be impaired.
Mostly mineral fillers, e.g. quartz, chalk, heavy spar, silicon carbide etc. are used as fillers. The proportion of fillers between 20 and 50 ~m is limited to particular advantage to 20% by wt. and in particular to 10~ by wt., the proportion of fillers below 20 ~m is limited in particular to S~ by wt. (in the sum of A to G). The proportion of fillers F + G in the entire system A to G is limited to 93~ by wt., since with higher filler contents F + G sufficient binder is no longer available to obtain a solid coating or body. If coatings are prepared, the proportion F ~ G in the sum of A to G is normally limited to max. 80S by wt., the region of 60 to 80~ by wt. is particularly preferred.
, ~, . , . :, ~ , , . " : ,. . -., . ~ , . ,,, - ,.,. ,: :
212a ~ 33 Moreover, the (meth)acrylate system according to the invention may also contain one or more solvents, whose proportion in the sum of A to E + H is s 15% by wt. and normally s 10% by wt. For example, acetone, ethyl acetate, methyl ethyl ketone are suitable as solvent. The ~olvents are used in particular to adjust the viscosity of the binder, so that said binder may be mixed better with the fillers F and G.
The (meth)acrylate system according to the invention is used for the preparation of conductive coatings. In particular during the preparation of conductive floor ccatings, the component F should be added in quantities such that the completely polymerised coating (or moulded part) has a surface resistance (DIN 53 482) of 103 to 109 Ohm and/or a leakage resistance (DIN 51 953) o$ 103 to 109 Ohm. Depending on the binder used, the guantity or type of conductive fillers F required for a desired conductivity may be determined in test series with the desired conductive fillers F.
A process for the preparation of a conductive coating also belongs to the present invention, wherein a polymer~sable, cold-setting, reactive (meth)acrylate system containing -A (meth)acrylate50 - 100% by wt.
methyl(meth)acrylate0 - 100% by wt.
C2 - C4 (meth)acrylate0 - 100~ by wt.
2C5 (meth)acrylate0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100~ by wt.
comonomers 0 - 50~ by wt.
vinyl aromatics0 - 30% by wt.
vinyl esters0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to 1 part of A
212~133 C 0 - 7 parts of a plasticiser to 10 parts of (A + B) D a redox system to be kept apart from the polymerisable constituents of the system until polymerisation, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
10 ~ customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 10 - 40~ by wt.
or carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10% by wt.
or finely divided metal in the form of flakes, powder or granules with a greatest particle length of s 5 mm 2 - 40% by wt.
or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in ~;
accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to 50S by wt.
G other fillers, based on the sum of A - G
o - 92~ by wt.
where the sum of F + G is limited to s93~ by wt.
2~2~3~3 and filiers between 20 and 50 ~m are limited to s 30% by wt.
and those below 20 ~m to s 10~ by wt.
H solvents based on the sum of A - E plus H
5 15~ by wt.
is applied to a surface to be coated and allowed to cure.
Said process is characterised in particular by the fact that it may be carried out at ambient temperature, i.e.
normally at between 0 and 35 C, but also, if desired, at more extreme temperatures such as -10 to ~45 C.
The conductive coatings may, in principle, be applied to all solid substrates; asphalt, asphalt concrete, bitumen screed, concrete, screed, ceramic tiles, metal, wood (e.g.
steel, aluminium) are particularly suitable. Depending on the type of substrate, it is advantageous to apply a primer before the coating according to the invention. Said primer belongs to the prior art in the case of coatings and has the following composition, for example solid epoxy resin 30~ by wt.
xylene 60~ by wt.
butanol 10~ by wt.
Primers are described, for example, in Degadur data sheet, part 1, 2 and 3, Degussa AG, Germany.
Normally, one or more highly conductive leakage strips, fibre strands, metal foil or wires are placed on the primer in order to improve the transverse conductivity, which materials are advantageously bonded at intervals of a few metres (1 to 10 m ), mostly in a s~uare and linked to each other in an electrically conductive manner. A main conductor is connected via the electric earth conductor to zero potential.
- 2~ 2~133 It is likewise advantageous to apply a conductive lacquer to ~or beneath) the earth conductor strips which is normally composed of a binder with or without solvent and conductive fillers. Said conductive lacquer is advantageously distributed evenly over the entire surface;
favourable layer thicknesses are in the region of 0.05 to 0.5 mm and in particular between 0.1 and 0.2 mm. A
customary composition of the conductive lacquer contains, for example : ' liquid epoxy resin (epoxy equivalent 190) 33.0% by wt.
amine hardener (aliphatic polyamine) amine number 700 14.0% by wt.
ethanol 17.5% by wt.
petrol 80/110C b.p. 10.5% by wt.
amorphous natural graphite 32-75 ~m 25.0% by wt.
or reactive methacrylate syrup 65% by wt.
amorphous natural graphite 32 - 75 ~m 25~ by wt.
20 carbon fibres 100 ~m 5% by wt.
acetone 5% by wt. -After the conductive lacquer has dried or cured, the conductive coating according to the invention is normally applied to said lacquer, preferably in a thickness of between 0.2 and 5 mm, particularly favourably in a thickness of between 1 and 2 mm. This is carried out, for example, by means of a trowel, doctor, drip applicator or spray gun, or with a roller or a brush.
If desired, a slip inhibitor may be applied to the conductive coating; this is carried out conveniently before curing with coarse fillers, for example, by scattering e.g. silicon carbide, quartz sand etc. mostly with a particle size of between 0.1 and 5 mm, preferably 0.2 to 2 mm.
, , . ~ . , ~ . ~ . , . :
~, i , . , . . ., ~ ~, . -212413~
The polymerisable, cold-setting, reactive (meth)acrylate system according to the invention may be provided in various premixes. Such premixes may contain, for example, ~all details in parts by weight) 1) the binder without the catalyst or initiator, e.g.:
polymethyl methacrylate, medium molecular weight 20.2 methyl methacrylate 58.0 dibutyl phthalate 20.0 dimethyl-p-toluidine 0.5 butane-1,4-diol dimethacrylate o.s paraffin melting point 56 C 0.5 methyl ethyl ketone 0.3 styrene 1.0 2) the fillers, e.g.:
carbon fibres 0.4 mm 4.0 aluminium powder 0 - 200 ~m 33.0 titanium dioxide rutile pigment 4.0 iron oxide black pigment 2.0 3) the hardener (catalyst or initiator in desensitising agent) e.g.:
dibenzoyl peroxide 50% 2.0 or 1) reactive methacrylate resin without hardener (A - E) 60.0 2) aluminium powder 0 - 100 ~m 30.0 carbon fibre 100 ~m 5.0 pigment powder 5.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 95.0 2) carbon fibres 400 ~m 5.0 3) hardener 2.0 or ~2~133 1) reactive methacrylate resin (A - E) without hardener 75.0 2) amorphous natural graphite 32 - 75 ~m 25.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 77.0 2) amorphous natural graphite 32 - 75 ~m 10.0 carbon fibres 100 ~m 3.0 aluminium spangle 10.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 75.0 2) amorphous natural graphite 32 - 75 ~m 20.0 carbon fibres 100 ~m 3.0 3) hardener 2.0 Said premixes are mixed in situ and applied immediately;
customary pot lives are lO to 20 min at +20 C.
It was not possible hitherto to prepare conductive coatings by means of a reactive, cold-setting tmeth)acrylate system, since the customary conductive fillers demix in said systems, agglomerate in an unsuitable manner and, in particular, inhibit radical polymerisation. This is particularly the case with graphite or carbon black which, because of its oxygen-containing groups situated on the surface, scavenges the radicals required for polymerisation. For this reason, such bodies were -obtainable hitherto only by hot-setting with azo compounds.
With the fillers described in the invention in combination with (meth)acrylates and a certain redox system for curing and in combination with other omponents, it is now possible to prepare the advantageous (meth)acrylate . ' ~ 21~13~' coatings also in a conductive manner. The use of metal spangle with a greatest particle length of max. 5 mm for the preparation of a conductive (meth)acrylic coating, and the use of carbon fibres with a thickness of 5 to 30 ~m and a length of 30 to 5000 ~m for the preparation of a conductive (meth)acrylic coating and the use of metal spangle with a greatest particle length o max. 5 mm for the preparation of a conducti~e (meth)acrylic coating also, therefore, belongs to the in~ention.
The invention is explained in more detail below on the basis of figures and embodiments.
Fig. 1 shows an amorphous natural graphite;
Fig. 2 shows a crystalline synthetic graphite; and Fig. 3 shows the structure of a conductive coating.
In Fig. 1, a drawing of an amorphous natural graphite is made from an REM photograph (magnification 1000, 25 kV). A
large particle 1 with a greatest dimension of approx.
103 ~m can be seen clearly. In addition, several smaller particles 2 with a size of 2 10 ~m can be seen. Par~icles 1 and 2 are mostly discus-like, i.e. they arP flattened and more or less rounded. The surface of particles 1 and 2 is occupied by flakes 3, virtually no crystalline structures can be discerned. In contrast to this, a crystalline synthetic graphite is illustrated in Fig. 2 under the same conditions. A graphite crystal 4 having a column structure can be seen clearly. Several fracture edges 5 run over crystal 4, which all emphasiæe the crystalline structure of crystal 4, i.e. fragments of said crystal also have essentially the angular (flattened) column structure. A
peeling, ~ery elongated platelet 6 can be seen clearly.
The sur~ace of the crystal is covered only by a few flakes 7, which mostly also have an angular appearance. No cold curing can be achieved with this graphite. ~ -5 Fig. 3 represents the structure of a coating according to ;-the invention by way of example. A primer 2 is applied to a concrete substrate 1, said primer consisting of solid epoxy resin 30.0% by wt.
xylene 60.0% by wt.
butanol 10.0~ by wt.
onto which, after drying, copper conductive strips 3 of thickness 0.05 mm and width 1 cm are placed. The copper conductive strips 3 are coated with a 0.2 mm thick conductive lacquer layer 4 composed of liquid epoxy resin 33.0i% by wt.
aliphatic polyamine 14.0% ~y wt.
ethanol 17.5% by wt.
petrol 80/110C boiling point10.5% by wt.
amorphous natural graphite 32-75 ~m 25.0% by wt.
onto which, after drying, a conductive coating 5 of thickness 1 to 1.5 mm and having the composition binder A - E (without catalyst) polymethyl methacrylate, medium molecular weight 20.2 parts by wt.
methyl methacrylate 57.0 parts by wt.
dibutyl phthalate 20.0 parts by wt.
dimethyl-p-toluidine 0.5 parts by wt.
butane-1,4-diol dimethacrylate0.5 parts by wt. ~-paraffin (56C) boiling point0.5 parts by wt.
methyl ethyl ketone 0.3 parts by wt.
styrene 1.0 parts by wt.
., ~-:
~, , ,, . , :. : . ~ . , ~124133 , ~
total conductive coating compound binder A - E as above 67.0 parts by wt.
carbon fibre 0.4 mm 3.0 parts by wt.
aluminium powder 0 - 200 ~m25.0 parts by wt.
titanium dioxide rutile pigment 3.0 parts by wt.
iron oxide black pigment2.0 parts by wt.
dibenzoyl peroxide 50~2.0 parts by wt.
is applied by means of a smoothing trowel. On this coating, the surface resistance (Ro) of 5.0 x 106 Q, the earth leakage resistance (R~) of 1.9 x 106 Q and the site transition resistance (RST) Of 2.0 x lo8 Q
was determined in accordance with DIN 53 482, DIN 51 953 and VDE 0 100 and practice, Gerhard Kiefer, VDE Verlag GmbH, Berlin, page 170 ff.
US-3 907 727 discloses the use of carbon black for blacki~g moulded bodies made from cast acrylat~ polymer. According to said patent, a dispersion of furnace black, acrylate polymer, methyl methacrylate monomer and a small proportion of nitrocellulose is prepared in the ~irst instance. A
catalyst is then added to said dispersion. The dispersion is then poured into the mould and heated to at least 50 C.
In view of the addition of nitrocellulose and the relatively high temperature required for polymerisation, said system is also unsuitable as a floor coating.
Filled polymer materials, e.g. mixtures o$ polybutyl methacrylate and CP-butyl acrylate-isobutylene which are filled with Ni powder, Al powder or graphite, are known from DKI, report no. 93040679707, 1993-04779. The Russian publication on which said abstract is based is concerned with the analysis of the elongation diagram of filled polymer materials. No references to floor coatings can be derived from the DKI abstract.
DE-OS 23 09 149 is concerned with polymer compounds in which the surface of a granular, inorganic substance is coated almost completely with a polyrmer material.
Inorganic substances mentioned are iron sesquioxide or carbon, inter alia, whilst monomers listed are methyl methacrylate or acrylic acid methyl ester. In an example, however, only iron sesquioxide particles are coated with - ~-polyvinyl chloride, which is polymerised at a temperature of 65 C. According to DE-OS 23 09 149, a heat-setting methacrylate system is used, whilst the inorganic particles ~
mentioned are provided with a polymer coating in order to ~ ~-produce a better strength during pressing than, ~or :~ -example, dry mixtures of inorganic substances and synthetic resin would exhibit.
,.
. . . ~ - . : : : ~ : , .: :
~12~33 Finally, a process for the polymerization of MMA in the presence of graphite is known from Angewandte Chemie 53 (1976), pages 65-72. Polymerization is carried out in S02_ containing water, a reaction between ash contained in graphite and HS03_ being assumed as an initiating reaction.
The aqueous redox system used in said publication does not seem to be suitable for the preparation of conductive floor coatings.
For some decades, electrically conductive floor coatings have been prepared on the basis of epoxides, polyurethanes or polyesters. In order to achieve conductivity, c~nductive fillers such as carbon black, graphite or surface-treated metal powders are added to the coatings. In case of (meth)acrylate coatings, said additions lead to disturbances in the curing process, however, with the result that corresponding conductive floor coatings based on (meth)acrylate could not be produced.
The preparation of conductive, acrylic (meth)acrylate coatings was, therefore, very expensive. US Patent 4,714,569 describes a coating process in which graphite and carbon black are pre-polymerized in a particular ratio with (meth)acrylic acid and functionalized (meth)acrylates, the mixture is further polymerized with an azo compound at elevated temperature, and the product obtained is cured with a cross-linking agent. Said process is unsuitable for coating large areas, particularly floors, because the required temperatures of between 80 and 90 C over several hours cannot be achieved in this case.
The present invention provides a polymerizable (meth)acrylate system which cures at ambient temperatures by mean~ of a redox system and which fulfills the requirements in respect of conductive coatings.
`` 212~33 More particularly, in one aspect, the invention provides polymerizable, cold-setting, reactive (meth)acrylate system for conductive floor coatings containing A (meth)acrylate >50 - 100% by wt.
methyl(meth)acrylate 0 - lO0~ by wt.
C2 ~ C4 (meth)acrylate 0 - 100% by wt.
2Cs (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100~ by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
,:
C 0 - 7 parts of plasticizer to 10 parts of (A + B) ~ ~
D a redox system to be kept apart from the polymerizable ~- -constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 30 10 - 40% by wt. or - 212'1133 carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of < 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to < 50% by wt.
G other fillers, based on the sum of A - G
0 ~ 92% by wt. where the sum of F + G is limited to < 93% by wt.
and fillers between 20 and 50 ~m are limited to < 30% by wt.
and those below 20 ~m to < 10% by wt.
20 H solvents based on the sum of A - E plus H S 15% by wt.
The polymerizable, cold-setting, reactive (meth)acrylate system according to the invention is composed of the components A to E, which together represent the binder, the conductive fillers F and other fillers G, and a possible proportion of a solvent H.
The binder (A to E) is, in turn, composed of polymerizable monomers A, optionally (pre)polymers B which are soluble or 4a ~24~3~
capable of swelling in said monomers, optionally plasticizer C, a redox system D, and customary additives E.
A single nonomer may be used as monomer A, e.g.
5 methyl(meth)acrylate, but a mixture is normally used. The composition of component A is:
(meth)acrylate>50 - 100% by wt.
methyl(meth)acrylate 0 - 100% by wt.
C2 ~ C4 (neth)acrylate 0 - 100% by wt.
C5 (meth)acrylate0 - S0% by wt.
polyhydric (meth)acrylates 0 - 100% by wt.
comonomers0 - 50% by wt.
vinyl aromatics0 - 30% by wt.
vinyl esters0 - 30% by wt.
Preferably, styrene is limited to max. 20% by wt. in A
because a higher content leads to disturbances during cold setting, and considerable odor problems can be expected. ~
: : ..
A constituent placed in brackets stands for its optional usability, i.e. (meth)acrylate stands for acrylate and/or methacrylate. The monomer component A contains at least > ~-50% by wt. of (meth)acrylate, monohydric (meth)acrylates with a Cl - C4 ester group being preferred. Longer-chain esters, i.e. those with a C5 or longer chain ester are 4b 212~133 limited to 50% by wt. in component A. Said esters make coatings or moulded parts more flexible, but also softer, as a result of which their performance characteristics are restricted. Preferably, polyhydric (meth)acrylates are also contained in component A, whereby component A may also be composed completely of polyhydric (meth)acrylates.
In addition to (meth)acrylates, component A may also contain other comonomers, their proportion being limited to 50% by wt. Of said comonomers, vinyl aromatics and/or vinyl esters may be contained in each case in quantities up to 30~ by wt. in component A. Higher proportions of vinyl aromatics are difficult to incorporate during polymerisation and may lead to demixing of the system.
Moreover, higher proportions of vinyl esters may cure insufficiently at low temperatures and tend to exhibit greater shrinkage.
Preferably, component A is composed of 80 - 100~ by wt. and in particular preference 90 -100~ by wt. of (meth)acrylates, since favourable performance characteristics for coatings or moulded parts may be achieved with said monomers. The proportion of C2 - C4 esters in (meth)acrylates is limited preferably to 50% by wt. in component A, said esters are contained preferably in a quantity of max. 30% by wt. and particularly advantageously in a quantity of max. 20~i by wt. in component A. Similarly, the 2C5 esters of (meth)acrylic acid are limited preferably to 30% by wt. and particularly advantageously to 15% by wt. Particularly flexible and non-soiling coating compounds can thereby be produced.
Suitable monofunctional (meth)acrylates are, in particular, methyl methacrylate, butyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyltriglycol methacrylate,hydoxypropyl methacrylate; in particular ~inyl toluene, styrene, vinyl esters are ~uitable as comonomers.
- ` 2~ 2 ~33 Poly~unctional (meth)acrylates are contained particularly advantageously in component A, their content lying normally in the region of 1 to 50% by wt. and mostly 1 to 10% by wt.
in A. The polyfunctional (meth)acrylates are used for linking polymers between linear molecules. As a result, properties such as flexibility, scratch resistance, melting point or curing processes can be manipulated.
Customary polyfunctional (meth)acrylates are triethylene glycol dimethacrylate (TEDMA), trimethylolpropane trimethacrylate (TRIM), butane-1,4-diol dimethacrylate (1,4-BDMA).
In order to ad~ust the viscosity of the binder and the process characteristics and to achieve better curing, a polymer or prepolymer may be added to component A. Said (pre)polymer should be soluble or capable of swelling in A.
Up to 2 parts of the prepolymer B to one part of A are used. In particular, poly(meth)acrylates are suitable, whereby said materials may be dissolved as solid polymer in A, or whereby a so-called syrup may be used, i.e. partially polymerised masses of corresponding monomers. Moreover, polyvinyl chloride, polyvinyl acetate, polystyrene, epoxy resins, epoxy(meth)acrylates, unsaturated polyesters, polyurethanes or mixtures thereof are suitable. Said polymers bring about in the binder e.g. special flexibility ~-properties, shrinkage control, stabiliser, skin former or process improver.
Thin coatings, i.e. those less than 5 mm, contain preferably at least 1% by wt., particularly advantageously at least 3% by wt. of a high molecular weight polymer, e.g.
poly(meth)acrylate, based on the sum of A + B.
Moreover, the binder normally contains a plasticiser, whereby up to 7 parts of a plasticiser to 10 parts of A + B
may be used. Normally, the plasticiser proportion C in the ~241~3 sum of A to C is 5 - 25~ by wt., and mostly 10 - 20~ by wt.
The plasticiser is used e.g. as an acceptor for peroxide components for the automatic 2-component mixing process (desensitising agent), to control the compressive and flexural strengths and to vary the surface tension.
Suitable plasticisers are e.g. phthalic acid esters, adipic acid esters, chlorinated paraffins, urea resins, melamine resins, modified phenolates, polyglycol urethanes.
The binder (A to E) may further contain customary additives E, of the kind mostly used in reactive (meth)acrylate systems. Said additives are used, e.g. to neutralise oxygen inhibition; in particular, paraffins in a quantity of 0.05 to 5~ by wt. in the binder A to ~ and/or phosphites in a quantity of 0.0~ to lS by wt. in A to E and also a polymer skin foxmation (paraffin-free) are suitable for this purpose. For the latter, in order to achieve a non-inhibited surface without paraffin, e.g. extremely high molecular weight polymers may be used as additive, particularly if methyl methacrylate is used alone. Methyl methacrylate evaporates on the surface even during curing and leaves behind a tack-free surface due to polymer skin formation.
In addition, defoamers, wetting agents, thixotropic agents, inhibitors, dulling agents, blueing agents, W stabilisers, polymerisation chain regulators may be added.
The binder A to E according to the invention is suitable for cold setting, e.g. contains for polymerisation a redox system composed of an accelerator and a peroxide catalyst or initiator, said components being added in sufficient quantity for the cold setting of component A. The accelerator is normally used in a quantity of 0.01 to 5~ by wt. in A to ~, particularly advantageously in a quantity of G.5 to 1.5~ by wt. In particular, amines and mercaptans ~ 2~2~33 are suitable as accelerators, dimethyl-p-toluidine, diisopropoxy-p-toluidine, diethylol-p-toluidine, dimethylaniline and glycol dimercaptoacetate are preferred.
In addition, organic metal salts which are normally used in the region of 0.001 to 2~ by wt. in A to E are used as accelerators. For example, cobalt naphthenate, copper naphthenate, cobalt oleate, copper oleate are suitable.
In particular, dibenzoyl peroxide and methyl ethyl ketone peroxide are suitable as peroxide catalyst. The peroxides are normally used in a quantity of 0.1 to 10% by wt. and in particular in a quantity of 0.5 to 5% by wt. in the binder.
Of the component D, the accelerators e.g.
dimethylparatoluidine may already be contained in the binder without polymerisation taking place at ambient temperature. By adding the remaining constituents of component D, the reaction is initiated, component D
normally being proportioned such that the tmeth)acrylate system has a pot life of 10 min to 20 min. The (meth)acrylate system according to the in~ention contains, therefore, the complete component D only immediately before use; until use, component D is contained only in part or not at all, or in other words, until polymerisation of the polymerisable constituents, the complete operative redox system must be kept apart from said constituents, whereas individual constituents of the redox system may already be premixed with polymerisable substances.
As constituent~ which are important to the invention, the (meth)acrylate system contains component F, one or more fillers, and namely based on the sum of A to F
amsrphous or spheroidal graphite 10 - 40% by wt.
or 35 carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10~ by wt.
~12~13~
or finely divided metal in the form of flakes, powder or granules with a greatest particle length s 5 mm 2 - 40% by wt.
5 or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of the conductive fillers being limited to <50~ by wt.
The amorphous or spheroidal graphite component is normally natural graphite. It is important in this connection that crystalline graphite, normally this is synthetic graphite, is not used. Only graphite whose particles are rounded is suitable ~or the polymerisable, cold-setting, reactive (meth)acrylate system according to the invention. Said graphite particles normally lie in a particle size range of 20 s x s 100 ~m, where x stands for the greatest particle length. The particles are noxmally platelets with highly rounded edges. Mostly, the graphite is used in a quantity of max. 30% by wt. and normally in a quantity of at least 20~ by wt., based on the sum of A to F.
Normally, the commercially obtainable amorphous natural graphite may be used as graphite; in the event of poor polymerisation tslow curing or none at all, tacky surface), the selection from the amorphous natural graphites by X-ray electron microscopy should be made to the effect that the amorphous natural graphite used has particularly rounded edges. In this way, the expert may easily select a suitable graphite. At least 80~ by wt. of the graphite - used should have a greatest particle length of between 20 and 1000 ~m, preferably at least 90~ by wt. h~ve a greatest particle length exceeding 20 ~m. Those graphites in which less than 20~ by wt. are below ~0 ~m and particularly less than 20~ by wt. are below 32 ~m on screening are -` 2~ 133 particularly advantageous. The natural graphites normally have a carbon proportion of >70% by wt. and mostly a correspondingly high ash proportion. The normally mineral accompanying substances in natural graphite are not troublesome, on the contrary, they reduce the inhibiting effect of graphite.
The carbon fibres to be used according to the invention normally have a length in the region of 50 to 2000 ~m and in particular preference in the region of 100 to 1000 ~m.
Depending on the purpose, fibre lengths below 500 ~m are particularly suitable. The proportion of carbon fibres in A to F is particularly advantageously 2 to 5% by wt. and in particular 3 to 4~ by wt. Said ranges are particularly ad~antageous in the case of coatings with (meth)acrylate systems because long carbon fibres readily align themselves vertically in said systems and thus project in a brush-like manner on the surface, on the one hand, and do not achieve the desired conductivity effect, on the other hand. The carbon fibres are used in particular for light-coloured coatings, since a smaller proportion is needed than with graphite. Combinations of carbon fibre and graphite are also particularly advantageous, since inexpensive coatings with good conductivity may be prepared by this means.
Moreover, metal spangles, powders and granules which preferably ha~e a greatest particle length of 5 2 mm may be used in the conductive systems according to the present invention. Said metals in the form of flakes, powder or gra~ules are also used in particular in cases where ligh~-coloured coatings are desired. Normally, the metal fillers are likewise used together with graphite. Copper, aluminium and chromium-nickel steel are suitable as metal fillers.
It is particularly important in the case of metal fillers -~
that they are neither anodised nor pre-treated with fatty . ' ' . ' ~ .
i ~ 2~133 acid or silicone oil since such metal fillers are either incompatible with (meth)acrylic systems or do not lead to the desired conductivity. If the conductive fillers F are used in mixture, smaller quantities of the individual S component F than those stated above may be used, corresponding to the proportion in the sum F, the maximum quantity of conductive fillers is limited to 50% by wt. in the system A to F.
Apart from the conductive fillers F, the systems according to the invention normally contain other fillers, whereby these are limited in the sum of A to G to 0 to 92~ by wt., and the sum of F + G is limited to s 93% by wt., and fillers between 20 and 50 ~m are limited to s 30~ by wt.
and those below 20 ~m to s 10% by wt. The particle size of fillers G is determined by screen analysis and is required for obtaining a sufficient conductivity of the cured (meth)acrylate system. If larger quantities of fillers between 20 and 50 ~m and in particular below 20 ~m than those stated are contained in the sum of A to G, the conductivity of the cured system will be impaired.
Mostly mineral fillers, e.g. quartz, chalk, heavy spar, silicon carbide etc. are used as fillers. The proportion of fillers between 20 and 50 ~m is limited to particular advantage to 20% by wt. and in particular to 10~ by wt., the proportion of fillers below 20 ~m is limited in particular to S~ by wt. (in the sum of A to G). The proportion of fillers F + G in the entire system A to G is limited to 93~ by wt., since with higher filler contents F + G sufficient binder is no longer available to obtain a solid coating or body. If coatings are prepared, the proportion F ~ G in the sum of A to G is normally limited to max. 80S by wt., the region of 60 to 80~ by wt. is particularly preferred.
, ~, . , . :, ~ , , . " : ,. . -., . ~ , . ,,, - ,.,. ,: :
212a ~ 33 Moreover, the (meth)acrylate system according to the invention may also contain one or more solvents, whose proportion in the sum of A to E + H is s 15% by wt. and normally s 10% by wt. For example, acetone, ethyl acetate, methyl ethyl ketone are suitable as solvent. The ~olvents are used in particular to adjust the viscosity of the binder, so that said binder may be mixed better with the fillers F and G.
The (meth)acrylate system according to the invention is used for the preparation of conductive coatings. In particular during the preparation of conductive floor ccatings, the component F should be added in quantities such that the completely polymerised coating (or moulded part) has a surface resistance (DIN 53 482) of 103 to 109 Ohm and/or a leakage resistance (DIN 51 953) o$ 103 to 109 Ohm. Depending on the binder used, the guantity or type of conductive fillers F required for a desired conductivity may be determined in test series with the desired conductive fillers F.
A process for the preparation of a conductive coating also belongs to the present invention, wherein a polymer~sable, cold-setting, reactive (meth)acrylate system containing -A (meth)acrylate50 - 100% by wt.
methyl(meth)acrylate0 - 100% by wt.
C2 - C4 (meth)acrylate0 - 100~ by wt.
2C5 (meth)acrylate0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100~ by wt.
comonomers 0 - 50~ by wt.
vinyl aromatics0 - 30% by wt.
vinyl esters0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to 1 part of A
212~133 C 0 - 7 parts of a plasticiser to 10 parts of (A + B) D a redox system to be kept apart from the polymerisable constituents of the system until polymerisation, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
10 ~ customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 10 - 40~ by wt.
or carbon fibre with a thickness in the region of 5 - 30 ~m and a length in the region of 30 - 5000 ~m 1 - 10% by wt.
or finely divided metal in the form of flakes, powder or granules with a greatest particle length of s 5 mm 2 - 40% by wt.
or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in ~;
accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to 50S by wt.
G other fillers, based on the sum of A - G
o - 92~ by wt.
where the sum of F + G is limited to s93~ by wt.
2~2~3~3 and filiers between 20 and 50 ~m are limited to s 30% by wt.
and those below 20 ~m to s 10~ by wt.
H solvents based on the sum of A - E plus H
5 15~ by wt.
is applied to a surface to be coated and allowed to cure.
Said process is characterised in particular by the fact that it may be carried out at ambient temperature, i.e.
normally at between 0 and 35 C, but also, if desired, at more extreme temperatures such as -10 to ~45 C.
The conductive coatings may, in principle, be applied to all solid substrates; asphalt, asphalt concrete, bitumen screed, concrete, screed, ceramic tiles, metal, wood (e.g.
steel, aluminium) are particularly suitable. Depending on the type of substrate, it is advantageous to apply a primer before the coating according to the invention. Said primer belongs to the prior art in the case of coatings and has the following composition, for example solid epoxy resin 30~ by wt.
xylene 60~ by wt.
butanol 10~ by wt.
Primers are described, for example, in Degadur data sheet, part 1, 2 and 3, Degussa AG, Germany.
Normally, one or more highly conductive leakage strips, fibre strands, metal foil or wires are placed on the primer in order to improve the transverse conductivity, which materials are advantageously bonded at intervals of a few metres (1 to 10 m ), mostly in a s~uare and linked to each other in an electrically conductive manner. A main conductor is connected via the electric earth conductor to zero potential.
- 2~ 2~133 It is likewise advantageous to apply a conductive lacquer to ~or beneath) the earth conductor strips which is normally composed of a binder with or without solvent and conductive fillers. Said conductive lacquer is advantageously distributed evenly over the entire surface;
favourable layer thicknesses are in the region of 0.05 to 0.5 mm and in particular between 0.1 and 0.2 mm. A
customary composition of the conductive lacquer contains, for example : ' liquid epoxy resin (epoxy equivalent 190) 33.0% by wt.
amine hardener (aliphatic polyamine) amine number 700 14.0% by wt.
ethanol 17.5% by wt.
petrol 80/110C b.p. 10.5% by wt.
amorphous natural graphite 32-75 ~m 25.0% by wt.
or reactive methacrylate syrup 65% by wt.
amorphous natural graphite 32 - 75 ~m 25~ by wt.
20 carbon fibres 100 ~m 5% by wt.
acetone 5% by wt. -After the conductive lacquer has dried or cured, the conductive coating according to the invention is normally applied to said lacquer, preferably in a thickness of between 0.2 and 5 mm, particularly favourably in a thickness of between 1 and 2 mm. This is carried out, for example, by means of a trowel, doctor, drip applicator or spray gun, or with a roller or a brush.
If desired, a slip inhibitor may be applied to the conductive coating; this is carried out conveniently before curing with coarse fillers, for example, by scattering e.g. silicon carbide, quartz sand etc. mostly with a particle size of between 0.1 and 5 mm, preferably 0.2 to 2 mm.
, , . ~ . , ~ . ~ . , . :
~, i , . , . . ., ~ ~, . -212413~
The polymerisable, cold-setting, reactive (meth)acrylate system according to the invention may be provided in various premixes. Such premixes may contain, for example, ~all details in parts by weight) 1) the binder without the catalyst or initiator, e.g.:
polymethyl methacrylate, medium molecular weight 20.2 methyl methacrylate 58.0 dibutyl phthalate 20.0 dimethyl-p-toluidine 0.5 butane-1,4-diol dimethacrylate o.s paraffin melting point 56 C 0.5 methyl ethyl ketone 0.3 styrene 1.0 2) the fillers, e.g.:
carbon fibres 0.4 mm 4.0 aluminium powder 0 - 200 ~m 33.0 titanium dioxide rutile pigment 4.0 iron oxide black pigment 2.0 3) the hardener (catalyst or initiator in desensitising agent) e.g.:
dibenzoyl peroxide 50% 2.0 or 1) reactive methacrylate resin without hardener (A - E) 60.0 2) aluminium powder 0 - 100 ~m 30.0 carbon fibre 100 ~m 5.0 pigment powder 5.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 95.0 2) carbon fibres 400 ~m 5.0 3) hardener 2.0 or ~2~133 1) reactive methacrylate resin (A - E) without hardener 75.0 2) amorphous natural graphite 32 - 75 ~m 25.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 77.0 2) amorphous natural graphite 32 - 75 ~m 10.0 carbon fibres 100 ~m 3.0 aluminium spangle 10.0 3) hardener 2.0 or 1) reactive methacrylate resin (A - E) without hardener 75.0 2) amorphous natural graphite 32 - 75 ~m 20.0 carbon fibres 100 ~m 3.0 3) hardener 2.0 Said premixes are mixed in situ and applied immediately;
customary pot lives are lO to 20 min at +20 C.
It was not possible hitherto to prepare conductive coatings by means of a reactive, cold-setting tmeth)acrylate system, since the customary conductive fillers demix in said systems, agglomerate in an unsuitable manner and, in particular, inhibit radical polymerisation. This is particularly the case with graphite or carbon black which, because of its oxygen-containing groups situated on the surface, scavenges the radicals required for polymerisation. For this reason, such bodies were -obtainable hitherto only by hot-setting with azo compounds.
With the fillers described in the invention in combination with (meth)acrylates and a certain redox system for curing and in combination with other omponents, it is now possible to prepare the advantageous (meth)acrylate . ' ~ 21~13~' coatings also in a conductive manner. The use of metal spangle with a greatest particle length of max. 5 mm for the preparation of a conductive (meth)acrylic coating, and the use of carbon fibres with a thickness of 5 to 30 ~m and a length of 30 to 5000 ~m for the preparation of a conductive (meth)acrylic coating and the use of metal spangle with a greatest particle length o max. 5 mm for the preparation of a conducti~e (meth)acrylic coating also, therefore, belongs to the in~ention.
The invention is explained in more detail below on the basis of figures and embodiments.
Fig. 1 shows an amorphous natural graphite;
Fig. 2 shows a crystalline synthetic graphite; and Fig. 3 shows the structure of a conductive coating.
In Fig. 1, a drawing of an amorphous natural graphite is made from an REM photograph (magnification 1000, 25 kV). A
large particle 1 with a greatest dimension of approx.
103 ~m can be seen clearly. In addition, several smaller particles 2 with a size of 2 10 ~m can be seen. Par~icles 1 and 2 are mostly discus-like, i.e. they arP flattened and more or less rounded. The surface of particles 1 and 2 is occupied by flakes 3, virtually no crystalline structures can be discerned. In contrast to this, a crystalline synthetic graphite is illustrated in Fig. 2 under the same conditions. A graphite crystal 4 having a column structure can be seen clearly. Several fracture edges 5 run over crystal 4, which all emphasiæe the crystalline structure of crystal 4, i.e. fragments of said crystal also have essentially the angular (flattened) column structure. A
peeling, ~ery elongated platelet 6 can be seen clearly.
The sur~ace of the crystal is covered only by a few flakes 7, which mostly also have an angular appearance. No cold curing can be achieved with this graphite. ~ -5 Fig. 3 represents the structure of a coating according to ;-the invention by way of example. A primer 2 is applied to a concrete substrate 1, said primer consisting of solid epoxy resin 30.0% by wt.
xylene 60.0% by wt.
butanol 10.0~ by wt.
onto which, after drying, copper conductive strips 3 of thickness 0.05 mm and width 1 cm are placed. The copper conductive strips 3 are coated with a 0.2 mm thick conductive lacquer layer 4 composed of liquid epoxy resin 33.0i% by wt.
aliphatic polyamine 14.0% ~y wt.
ethanol 17.5% by wt.
petrol 80/110C boiling point10.5% by wt.
amorphous natural graphite 32-75 ~m 25.0% by wt.
onto which, after drying, a conductive coating 5 of thickness 1 to 1.5 mm and having the composition binder A - E (without catalyst) polymethyl methacrylate, medium molecular weight 20.2 parts by wt.
methyl methacrylate 57.0 parts by wt.
dibutyl phthalate 20.0 parts by wt.
dimethyl-p-toluidine 0.5 parts by wt.
butane-1,4-diol dimethacrylate0.5 parts by wt. ~-paraffin (56C) boiling point0.5 parts by wt.
methyl ethyl ketone 0.3 parts by wt.
styrene 1.0 parts by wt.
., ~-:
~, , ,, . , :. : . ~ . , ~124133 , ~
total conductive coating compound binder A - E as above 67.0 parts by wt.
carbon fibre 0.4 mm 3.0 parts by wt.
aluminium powder 0 - 200 ~m25.0 parts by wt.
titanium dioxide rutile pigment 3.0 parts by wt.
iron oxide black pigment2.0 parts by wt.
dibenzoyl peroxide 50~2.0 parts by wt.
is applied by means of a smoothing trowel. On this coating, the surface resistance (Ro) of 5.0 x 106 Q, the earth leakage resistance (R~) of 1.9 x 106 Q and the site transition resistance (RST) Of 2.0 x lo8 Q
was determined in accordance with DIN 53 482, DIN 51 953 and VDE 0 100 and practice, Gerhard Kiefer, VDE Verlag GmbH, Berlin, page 170 ff.
Claims (11)
1. Polymerizable, cold-setting, reactive (meth)acrylate system for conductive floor coatings containing A (meth)acrylate >50 - 100% by wt.
methyl(meth)acrylate 0 - 100% by wt.
C2 - C4 (meth)acrylate 0 - 100% by wt.
?C5 (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100% by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
C 0 - 7 parts of plasticizer to 10 parts of (A + B) D a redox system to be kept apart from the polymerizable constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spherical graphite 10 - 40% by wt. or carbon fibre with a thickness in the region of 5 - 30 µm and a length in the region of 30 - 5000 µm 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of ? 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to < 50% by wt.
G other fillers, based on the sum of A - G
0 - 92% by wt. where the sum of F + G is limited to ? 93% by wt.
and fillers between 20 and 50 µm are limited to ? 30% by wt.
and those below 20 µm to ? 10% by wt.
H solvents based on the sum of A - E plus H ? 15% by wt.
methyl(meth)acrylate 0 - 100% by wt.
C2 - C4 (meth)acrylate 0 - 100% by wt.
?C5 (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylates 0 - 100% by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
C 0 - 7 parts of plasticizer to 10 parts of (A + B) D a redox system to be kept apart from the polymerizable constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spherical graphite 10 - 40% by wt. or carbon fibre with a thickness in the region of 5 - 30 µm and a length in the region of 30 - 5000 µm 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of ? 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to < 50% by wt.
G other fillers, based on the sum of A - G
0 - 92% by wt. where the sum of F + G is limited to ? 93% by wt.
and fillers between 20 and 50 µm are limited to ? 30% by wt.
and those below 20 µm to ? 10% by wt.
H solvents based on the sum of A - E plus H ? 15% by wt.
2. (Meth)acrylate system according to claim 1, characterized in that the graphite is an amorphous natural graphite.
3. (Meth)acrylate system according to claim 1, characterized in that 80% by wt. of the graphite has a greatest particle length of between 20 and 1000 µm.
4. (Meth)acrylate system according to claim 1, 2 or 3, characterized in that the carbon fibre has a linear dimension of 50 to 2000 µm.
5. (Meth)acrylate system according to claim 4, characterized in that the carbon fibre has a linear dimension of max. 1000 µm.
6. (Meth)acrylate system according to any one of claims 1 to 3 or 5, characterized in that the metal spangles are made of copper, aluminum or a combination thereof.
7. A process for the preparation of a conductive coating with a surface resistance (DIN 53 482) of 103 to 109 Ohm and/or leakage resistance (DIN 51 953) of 103 to 109 Ohm, characterized in that polymerizable, cold-setting, reactive (meth)acrylate system containing A (meth)acrylate 50 - 100% by wt.
methyl(meth)acrylate 0 - 100% by wt.
C2 - C4 (meth)acrylate 0 - 100% by wt.
?C5 (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylate 0 - 100% by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
C 0 - 7 parts of a plasticizer to 10 parts of (A + B) D a redox system to be kept apart from the polymerizable constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 10 - 40% by wt. or carbon fibre with a thickness in the region of 5 -m and a length in the region of 30 - 5000 m 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of ? 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to 50% by wt.
G other fillers, based on the sum of A - G 0 - 92% by wt. where the sum of F + G is limited to 93% by wt.
and fillers between 20 and 50 m are limited to 30% by wt.
and those below 20 m 10% by wt.
H solvents based on the sum of A - E
plus H 15% by wt.
is applied to a surface to be coated and allowed to cure.
methyl(meth)acrylate 0 - 100% by wt.
C2 - C4 (meth)acrylate 0 - 100% by wt.
?C5 (meth)acrylate 0 - 50% by wt.
polyhydric (meth)acrylate 0 - 100% by wt.
comonomers 0 - 50% by wt.
vinyl aromatics 0 - 30% by wt.
vinyl esters 0 - 30% by wt.
B 0 - 2 parts of a (pre)polymer which is soluble or capable of swelling in A to one part of A
C 0 - 7 parts of a plasticizer to 10 parts of (A + B) D a redox system to be kept apart from the polymerizable constituents of the system until polymerization, at least in respect of one component of the redox system, containing an accelerator and a peroxide catalyst or initiator in a quantity sufficient for the cold-setting of component A
E customary additives F conductive fillers based on the sum of A - F
amorphous or spheroidal graphite 10 - 40% by wt. or carbon fibre with a thickness in the region of 5 -m and a length in the region of 30 - 5000 m 1 - 10% by wt. or finely divided metal in the form of flakes, powder or granules with a greatest particle length of ? 5 mm 2 - 40% by wt. or a mixture of two or all of said conductive fillers, the minimum quantity of each individual conductive filler in the mixture being reduced in accordance with its proportion in the mixture of conductive fillers, and the sum of conductive fillers being limited to 50% by wt.
G other fillers, based on the sum of A - G 0 - 92% by wt. where the sum of F + G is limited to 93% by wt.
and fillers between 20 and 50 m are limited to 30% by wt.
and those below 20 m 10% by wt.
H solvents based on the sum of A - E
plus H 15% by wt.
is applied to a surface to be coated and allowed to cure.
8. A process according to claim 7, characterized in that curing takes place at ambient temperature.
9. A process according to claim 7 or 8, characterized in that amorphous or spheroidal graphite is used for the preparation of a conductive, (meth)acrylic coating or conductive polymer concrete moulded parts.
10. A process according to claim 7 or 8, characterized in that carbon fibres having a thickness of 5 to 30 µm and a length of 30 to 5000 µm are used for the preparation of a conductive (meth)acrylic coating.
11. A process according to claim 7 or 8, characterized in that metal spangles with a greatest particle length of max. 5 mm are used for the preparation of a conductive (meth)acrylic coating.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4317302A DE4317302A1 (en) | 1993-05-25 | 1993-05-25 | Conductive floor coating |
| DEP4317302.0 | 1993-05-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2124133A1 true CA2124133A1 (en) | 1994-11-26 |
Family
ID=6488821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002124133A Abandoned CA2124133A1 (en) | 1993-05-25 | 1994-05-24 | (meth)acrylate system for conductive floor coatings and a process for the preparation of conductive floor coatings |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US5516546A (en) |
| EP (1) | EP0626430A1 (en) |
| CA (1) | CA2124133A1 (en) |
| DE (1) | DE4317302A1 (en) |
| FI (1) | FI942402A (en) |
| MY (1) | MY131676A (en) |
| SG (1) | SG49822A1 (en) |
| TW (1) | TW297041B (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1039506C (en) * | 1994-09-12 | 1998-08-12 | 宝山钢铁(集团)公司 | Stereo-space static electricity prevention and curing method |
| US5833452A (en) * | 1994-12-15 | 1998-11-10 | M-C Power Corporation | Coated metal sintering carriers for fuel cell electrodes |
| US6086791A (en) * | 1998-09-14 | 2000-07-11 | Progressive Coatings, Inc. | Electrically conductive exothermic coatings |
| US6107436A (en) * | 1998-10-05 | 2000-08-22 | 3M Innovative Properties Company | Polyfunctional polymer |
| US6350823B1 (en) | 1998-10-05 | 2002-02-26 | 3M Innovative Properties Company | Pavement marking composition |
| US6436315B2 (en) | 1999-03-19 | 2002-08-20 | Quantum Composites Inc. | Highly conductive molding compounds for use as fuel cell plates and the resulting products |
| US6365069B2 (en) | 1999-03-19 | 2002-04-02 | Quantum Composites Inc. | Process of injection molding highly conductive molding compounds and an apparatus for this process |
| US6251308B1 (en) | 1999-03-19 | 2001-06-26 | Premix | Highly conductive molding compounds and fuel cell bipolar plates comprising these compounds |
| JP5072140B2 (en) * | 2000-06-15 | 2012-11-14 | 新中村化学工業株式会社 | Floor coating composition and coating coating thereof |
| GB0016747D0 (en) * | 2000-07-08 | 2000-08-30 | Johnson Matthey Plc | Ink |
| WO2003037622A1 (en) * | 2001-11-01 | 2003-05-08 | Ionphase Oy | Electrically conductive covering material |
| US6752937B2 (en) * | 2001-12-17 | 2004-06-22 | Quantum Composites, Inc. | Highly conductive molding compounds having an increased distribution of large size graphite particles |
| GB0304515D0 (en) * | 2003-02-27 | 2003-04-02 | Dakocytomation Denmark As | Standard |
| GB0315991D0 (en) * | 2003-07-08 | 2003-08-13 | Dakocytomation Denmark As | Standard |
| EP1544258A1 (en) * | 2003-12-17 | 2005-06-22 | Tarkett SAS | Electrically conductive floor coverings |
| TWI381399B (en) * | 2005-07-12 | 2013-01-01 | Sulzer Metco Canada Inc | Enhanced performance conductive filler and conductive polymers made therefrom |
| BRPI0811171A2 (en) * | 2007-05-17 | 2014-12-23 | Johnson Diversey Inc | SURFACE COATING SYSTEM AND METHOD |
| US20080292801A1 (en) * | 2007-05-23 | 2008-11-27 | National Starch And Chemical Investment Holding Corporation | Corrosion-Preventive Adhesive Compositions |
| KR20080012393A (en) * | 2008-01-17 | 2008-02-11 | 김재호 | Water soluble-curable antistatic composition with excellent wear resistance and high transparency and conductive tile flooring material coated with the same |
| ITMI20130452A1 (en) * | 2013-03-26 | 2014-09-27 | Riem Service S R L | PROCESS FOR THE REGENERATION OF THE PUMPING GROUP OF A "OIL-FREE" VOLUMETRIC SCREW COMPRESSOR. |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3056750A (en) * | 1961-01-23 | 1962-10-02 | Air Reduction | Resin bonded electrical resistors and methods of producing the same |
| DE2028890A1 (en) * | 1970-06-12 | 1971-12-23 | Degussa | Filled methacrylic ester composition - based on monomer, for casting mouldings, profiles and electrical insulators |
| JPS4888184A (en) * | 1972-02-24 | 1973-11-19 | ||
| US3983075A (en) * | 1974-06-21 | 1976-09-28 | Kennecott Copper Corporation | Copper filled conductive epoxy |
| US3907727A (en) * | 1974-11-25 | 1975-09-23 | Du Pont | Process for dispersing carbon black in acrylate plastics |
| US4387115A (en) * | 1980-08-08 | 1983-06-07 | Mitsui Toatsu Chemicals, Inc. | Composition for conductive cured product |
| US4508640A (en) * | 1981-11-24 | 1985-04-02 | Showa Denko Kabushiki Kaisha | Electromagnetic wave-shielding materials |
| US4515710A (en) * | 1983-07-18 | 1985-05-07 | Gencorp Inc. | In-mold coating composition |
| US4714569A (en) * | 1986-07-22 | 1987-12-22 | Toska Co., Ltd. | Process for preparing conductive coating composition |
| US4959178A (en) * | 1987-01-27 | 1990-09-25 | Advanced Products Inc. | Actinic radiation-curable conductive polymer thick film compositions and their use thereof |
| JPS63215704A (en) * | 1987-03-04 | 1988-09-08 | Nippon Oil Co Ltd | Curable electrically conductive composition |
| US5068150A (en) * | 1988-02-01 | 1991-11-26 | Mitsui Kinzoku Kogyo Kabushiki Kaisha | Copper powder for electroconductive paints and electroconductive paint compositions |
| US5194182A (en) * | 1989-02-01 | 1993-03-16 | Union Oil Company Of California | Salt-containing polymer compositions |
| GB8920283D0 (en) * | 1989-09-07 | 1989-10-18 | Hill Robert G Q | Self temperature limiting electro-conducting composites |
| EP0563894B1 (en) * | 1992-03-31 | 1998-01-07 | Cemedine Co., Ltd. | Two-part room temperature curable composition |
-
1993
- 1993-05-25 DE DE4317302A patent/DE4317302A1/en not_active Ceased
-
1994
- 1994-05-14 TW TW083104370A patent/TW297041B/zh active
- 1994-05-17 SG SG1996006830A patent/SG49822A1/en unknown
- 1994-05-17 EP EP94107602A patent/EP0626430A1/en not_active Withdrawn
- 1994-05-20 MY MYPI94001300A patent/MY131676A/en unknown
- 1994-05-24 CA CA002124133A patent/CA2124133A1/en not_active Abandoned
- 1994-05-24 FI FI942402A patent/FI942402A/en unknown
- 1994-05-25 US US08/248,886 patent/US5516546A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| MY131676A (en) | 2007-08-30 |
| TW297041B (en) | 1997-02-01 |
| EP0626430A1 (en) | 1994-11-30 |
| US5516546A (en) | 1996-05-14 |
| DE4317302A1 (en) | 1994-12-01 |
| FI942402A (en) | 1994-11-26 |
| SG49822A1 (en) | 1998-06-15 |
| FI942402A0 (en) | 1994-05-24 |
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| FZDE | Discontinued |