CA1045808A - Polycarbonate composition having improved electrical tracking resistance - Google Patents
Polycarbonate composition having improved electrical tracking resistanceInfo
- Publication number
- CA1045808A CA1045808A CA195,849A CA195849A CA1045808A CA 1045808 A CA1045808 A CA 1045808A CA 195849 A CA195849 A CA 195849A CA 1045808 A CA1045808 A CA 1045808A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- polycarbonate
- percent
- composition
- high molecular
- 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.)
- Expired
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
- H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
- H01B3/42—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes polyesters; polyethers; polyacetals
- H01B3/421—Polyesters
- H01B3/426—Polycarbonates
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/36—Silica
Abstract
Abstract of the Disclosure The electrical tracking resistance or a high molecular weight aromatic polycarbonate composition containing silica flour or Farsil type respectively quartz flour of Farsil type is improved in comparison with glass fiber reinforced high molecular weight, aromatic polycarbonate compositions whereas the good mechanical and thermal properties of the glass fiber reinforced aromatic polycarbonate compositions are almost achieved. The polycarbonate composition of the invention optionally contains a hydrophobic inert pigment. The polycarbonate composition of the invention may be used for making components which are associated with electrical conductors.
Description
~045808 This invention relates generally to compositions which contain high molecular weight aromatic polycarbonates based on aromatic bis-hydroxy compounds, in particular on dihydroxydi-aryl compounds, and more particularly to such polycarbonates having improved electrical tracking resistance co~pared with glass fiber reinforced high molecular weight, aromatic poly-carbonate compositions.
~ ore and~more attention and consideration are being given to the electrical tracking resistance of chemical materials. An adequate electrical tracking resistance is demanded of those synthetic substances which carry voltage-conducting parts or are in contact with them. Since the sur-face of a synthetic substance may come into contact with moisture and dust, leakage current paths may form on such a surface and, as a further consequence, leakage tracks, and (surface) leakage currents may flow which, finally, may, in the case of materials inadequately resistant to leakage current, lead to breakdown and possibly to the starting of a fire.
Materials with low or inadequate resistance to (surface) leakage current should therefore, for these fields of appli-cation, be provided with a sufficiently electrical tracking resistant finish.
:, .
It is known that the electrical tracking resistance of chemical materials which consist predominantly or exclusively of aromatic polymers, such as polystyrene or aromatic poly-sulphones, is not satisfactory. Although high-molecular-. . .
weight aromatic polycarbonates based on dihydroxydiaryl com-pounds, in particular those based on bis-2-(4-hydroxyphenyl)-propane(Bisphenol A) have a resistance to the flow of (sur-face) leakage current when measured by the KB method with test solution F according to VDE (Verband Deutsche`r Elektrotechniker, ,, _ .. . _, . .. . ... . . ..
Le A 14 993 - 1 - ~ ~
':
i .............. ...
- . , :
i.e. Association of German Electrical Engineers) Instruction Sheet 0303, Part 1, of September 1964 of about 300 ~ 20, the resistance to (surface) leakage current of high-molecular-weight aromatic polycarbonates which are reinforced with glass fibers is distinctly lower or only 180 + 20. Test solution F
is a 0.1~ aqueous ammonium chloride solution.
It is therefore an object of this invention to pro-vide a high molecular weight, aromatic polycarbonate composition having improved electrical tracking resistance to surface leakage current in comparison with glass fiber reinforced, high molecular weight aromatic polycarbonate compositions, whereas the good mechanical and thermal properties of the glass fiber rein- .:
forced aromatic polycarbonate compositions are almost achieved;
another object of the invention is to provide a method for improving the resistance of a polycarbonate composition to surface leakage current having almost the good mechanical and , thermal properties of the glass fiber reinforced, high molecular weight aromatic polycarbonate compositions; a further object of the invention is to provide a molded polycarbonate composition which has almost the good mechanical and thermal properties of the glass fiber reinforced aromatic polycarbonate compositions and which has a satisfactory resistance to flow of leakage electric current and is suitable for molding parts which are associated with electrical conductors.
The foregoing objects and others are accomplished in accordance with this invention, generally speaking, by pro-viding a high molecular weight polycarbonate composition containing a silica flour of Farsil type respectively quartz flour of Farsil type. Polycarbontes containing silica are known in the art(compare the book "Polycarbonates", by Christopher and :~
Fox, Reinhold Publishing Corporation, New York, 1962, page 151);~
Le A 14 993 - 2 -. . .
.. . . . . . . . . . .
- ; , . ~ .
but it has now been found that high molecular weight aromatic polycarbonate compositions which have physical properties approaching those of a fiber-gla~ reinforced polycarbonate and having a better resistance to the flow of leakage current can be prepared by dispersing silica flour of Farsil type respectively quartz flour of Farsil type in the polycarbonate. A hydrophobic pigment which is inèrt to the polycarbonate may be included with the silica flour respectively quartz flour in the composition.
The polycarbonate compositions provided by the invention because of their resistance to surface leakage current in combination with other good physical properties are suitable for molding many different products but are particularly well suited for making parts for electrical appliances and electrical insulating compo-nents to be used for electrical engineering purposes.
The invention thus provides compostions which con-tain high-molecular weight aromatic polycarbonates based on aromatic bis-hydroxy compounds, in particular on dihydroxy-diaryl compounds, and which are characterized in that they have a content of a silica flour of Farsil type respectively quartz flour of Farsil type of about 10 percent to about 60 percent by weight, preferably of about 20 percent to about 40 percent by weight. These compositions may additionally contain a hydrophobic inert pigment, such as TiO2 or Cr203, in an amount of from about 2 percent to 20 percent by weight, preferably about 5 percent to about 10 percent by weight, the percentages by weight being in each case with respect to the weight of high-molecular-weight polycarbonate. -The compositions of the invention thus obtained have an electrical tracking resistance to surface leakage current which is at least 260 + 20 when measured by the KB method with Le A 14 993 - ~ -,' ' ;.~,.. .
- _ . . .. . .
" l~
16~4S~8 test solution F according to VDE Instruction Sheet 0303, Part 1 of September 1964.
Accordingly, the present invention pertains to a composition comprising (a) a high molecular weight aromatic polycarbonate and (b) about 10 to 60 weight percent, based on the high molecular weight polycarbonate, of silica flour of a maximum particle size less than 100 ~m and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent, based on the silica flour, wherein the flour is prepared by heating quartz materials to between 1400C and 1600C for several hours, 15 cooling them and comminuting them to size.
The present invention further pertains to a process for improving the resistance of a high molecular weight, aromatic polycarbonate to leakage current comprising dispersing in the polycarbonate about 10 to 60 weight percent, based on ` 20 the weight of the polycarbonate, of a silica flour having a particle size of less than 100 ~m and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent based on the silica flour wherein the flour is prepared by heating quartz materials to between 1400C and 1600C for several hours, cooling them and comminuting them to size.
The present invention also pertains to an electrical insulator shaped from the composition of the invention and having a minimum tracking resistance of 260 + 20 volts and LeA 14~993-ca ~ ~4~
A:~
, 1~)4S8~)1B
a minimum impact strength of about 70 kpcm/cm2.
The polycarbonates, useful for the instant invention, are those prepared by reaction of aromatic bis~hydroxy compounds, particularly of dihydroxydiarylalkanes, with phosgene or diesters of carbonic acid. Polycarbonates prepared from unsubstituted dihydroxydiarylalkanes or those prepared from dihydroxydiarylalkanes having acyl radicals which carry methyl groups or halogen atoms in the ortho- or meta-position to the hydroxyl group are included. Branched polycarbonates are also suitable.
The polycarbonates may have an average molecular weight between about 10,000 and about 100,000, preferably between about 20,000 and 40,000.
Examples of suitable aromatic bis-hydroxy compounds for preparing the polycarbonates are hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis-(hydroxyphenyl)-alkanes as for example Cl-C8-alkylene- or C2-C8-alkylidene-bisphenols, bis~hydroxyphenyl)cycloalkanes such as, for example, C5-C15-cycloalkylene- or C5-C15-cycloalkylidene-bisphenols, bis-(hydroxyphenyl)-sulphides, -ethers, -ketones, -sulphoxides or -sulphones. Further, a,~'-bis-thydroxyphenyl)-diisopropyl-benzene as well as the corresponding nuclearly alkylated or nuclearly halogenated compounds and the like. Preferred are polycarbonates based on bis-(4-hydroxyphenyl)-propane-2,2 (bisphenol A), bis-(4-hydroxy-3,5-dichlorophenyl)-propane-
~ ore and~more attention and consideration are being given to the electrical tracking resistance of chemical materials. An adequate electrical tracking resistance is demanded of those synthetic substances which carry voltage-conducting parts or are in contact with them. Since the sur-face of a synthetic substance may come into contact with moisture and dust, leakage current paths may form on such a surface and, as a further consequence, leakage tracks, and (surface) leakage currents may flow which, finally, may, in the case of materials inadequately resistant to leakage current, lead to breakdown and possibly to the starting of a fire.
Materials with low or inadequate resistance to (surface) leakage current should therefore, for these fields of appli-cation, be provided with a sufficiently electrical tracking resistant finish.
:, .
It is known that the electrical tracking resistance of chemical materials which consist predominantly or exclusively of aromatic polymers, such as polystyrene or aromatic poly-sulphones, is not satisfactory. Although high-molecular-. . .
weight aromatic polycarbonates based on dihydroxydiaryl com-pounds, in particular those based on bis-2-(4-hydroxyphenyl)-propane(Bisphenol A) have a resistance to the flow of (sur-face) leakage current when measured by the KB method with test solution F according to VDE (Verband Deutsche`r Elektrotechniker, ,, _ .. . _, . .. . ... . . ..
Le A 14 993 - 1 - ~ ~
':
i .............. ...
- . , :
i.e. Association of German Electrical Engineers) Instruction Sheet 0303, Part 1, of September 1964 of about 300 ~ 20, the resistance to (surface) leakage current of high-molecular-weight aromatic polycarbonates which are reinforced with glass fibers is distinctly lower or only 180 + 20. Test solution F
is a 0.1~ aqueous ammonium chloride solution.
It is therefore an object of this invention to pro-vide a high molecular weight, aromatic polycarbonate composition having improved electrical tracking resistance to surface leakage current in comparison with glass fiber reinforced, high molecular weight aromatic polycarbonate compositions, whereas the good mechanical and thermal properties of the glass fiber rein- .:
forced aromatic polycarbonate compositions are almost achieved;
another object of the invention is to provide a method for improving the resistance of a polycarbonate composition to surface leakage current having almost the good mechanical and , thermal properties of the glass fiber reinforced, high molecular weight aromatic polycarbonate compositions; a further object of the invention is to provide a molded polycarbonate composition which has almost the good mechanical and thermal properties of the glass fiber reinforced aromatic polycarbonate compositions and which has a satisfactory resistance to flow of leakage electric current and is suitable for molding parts which are associated with electrical conductors.
The foregoing objects and others are accomplished in accordance with this invention, generally speaking, by pro-viding a high molecular weight polycarbonate composition containing a silica flour of Farsil type respectively quartz flour of Farsil type. Polycarbontes containing silica are known in the art(compare the book "Polycarbonates", by Christopher and :~
Fox, Reinhold Publishing Corporation, New York, 1962, page 151);~
Le A 14 993 - 2 -. . .
.. . . . . . . . . . .
- ; , . ~ .
but it has now been found that high molecular weight aromatic polycarbonate compositions which have physical properties approaching those of a fiber-gla~ reinforced polycarbonate and having a better resistance to the flow of leakage current can be prepared by dispersing silica flour of Farsil type respectively quartz flour of Farsil type in the polycarbonate. A hydrophobic pigment which is inèrt to the polycarbonate may be included with the silica flour respectively quartz flour in the composition.
The polycarbonate compositions provided by the invention because of their resistance to surface leakage current in combination with other good physical properties are suitable for molding many different products but are particularly well suited for making parts for electrical appliances and electrical insulating compo-nents to be used for electrical engineering purposes.
The invention thus provides compostions which con-tain high-molecular weight aromatic polycarbonates based on aromatic bis-hydroxy compounds, in particular on dihydroxy-diaryl compounds, and which are characterized in that they have a content of a silica flour of Farsil type respectively quartz flour of Farsil type of about 10 percent to about 60 percent by weight, preferably of about 20 percent to about 40 percent by weight. These compositions may additionally contain a hydrophobic inert pigment, such as TiO2 or Cr203, in an amount of from about 2 percent to 20 percent by weight, preferably about 5 percent to about 10 percent by weight, the percentages by weight being in each case with respect to the weight of high-molecular-weight polycarbonate. -The compositions of the invention thus obtained have an electrical tracking resistance to surface leakage current which is at least 260 + 20 when measured by the KB method with Le A 14 993 - ~ -,' ' ;.~,.. .
- _ . . .. . .
" l~
16~4S~8 test solution F according to VDE Instruction Sheet 0303, Part 1 of September 1964.
Accordingly, the present invention pertains to a composition comprising (a) a high molecular weight aromatic polycarbonate and (b) about 10 to 60 weight percent, based on the high molecular weight polycarbonate, of silica flour of a maximum particle size less than 100 ~m and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent, based on the silica flour, wherein the flour is prepared by heating quartz materials to between 1400C and 1600C for several hours, 15 cooling them and comminuting them to size.
The present invention further pertains to a process for improving the resistance of a high molecular weight, aromatic polycarbonate to leakage current comprising dispersing in the polycarbonate about 10 to 60 weight percent, based on ` 20 the weight of the polycarbonate, of a silica flour having a particle size of less than 100 ~m and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent based on the silica flour wherein the flour is prepared by heating quartz materials to between 1400C and 1600C for several hours, cooling them and comminuting them to size.
The present invention also pertains to an electrical insulator shaped from the composition of the invention and having a minimum tracking resistance of 260 + 20 volts and LeA 14~993-ca ~ ~4~
A:~
, 1~)4S8~)1B
a minimum impact strength of about 70 kpcm/cm2.
The polycarbonates, useful for the instant invention, are those prepared by reaction of aromatic bis~hydroxy compounds, particularly of dihydroxydiarylalkanes, with phosgene or diesters of carbonic acid. Polycarbonates prepared from unsubstituted dihydroxydiarylalkanes or those prepared from dihydroxydiarylalkanes having acyl radicals which carry methyl groups or halogen atoms in the ortho- or meta-position to the hydroxyl group are included. Branched polycarbonates are also suitable.
The polycarbonates may have an average molecular weight between about 10,000 and about 100,000, preferably between about 20,000 and 40,000.
Examples of suitable aromatic bis-hydroxy compounds for preparing the polycarbonates are hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis-(hydroxyphenyl)-alkanes as for example Cl-C8-alkylene- or C2-C8-alkylidene-bisphenols, bis~hydroxyphenyl)cycloalkanes such as, for example, C5-C15-cycloalkylene- or C5-C15-cycloalkylidene-bisphenols, bis-(hydroxyphenyl)-sulphides, -ethers, -ketones, -sulphoxides or -sulphones. Further, a,~'-bis-thydroxyphenyl)-diisopropyl-benzene as well as the corresponding nuclearly alkylated or nuclearly halogenated compounds and the like. Preferred are polycarbonates based on bis-(4-hydroxyphenyl)-propane-2,2 (bisphenol A), bis-(4-hydroxy-3,5-dichlorophenyl)-propane-
2,2 (bisphenol A), bis-(4-hydroxy-3,5-dichlorophenyl)-propane-2,2 (tetrachlorobisphenyl A), bis-(4-hydroxy-3,5-dibromophenyl)-propane-2,2 (tetrabromobisphenol A), bis-(4-hydroxy-3,5-di-LeA 14~993-ca -4a-- ` , ~ , . .' : -1~)45808 methylphenyl)-propane-2,2 (tetramethylbisphenol A), bis-(4-hydroxyphenyl)-cyclohexane-l,l (bisphenol Z) and based on tri-nuclear bisphenols such as a,~'-bis-(~-hydroxyphenyl)-p-diisopropylbenzene.
Additional aromatic bis-hydroxy compounds suitable for the preparation of the polycarbonate are described in U. S. Patents 3,028,365; 2,999,835; 3,148,172; 3,271,368;
2,970,137; 2,991,273; 3,271,367; 3,280,078; 3,014,891; and 2,999,846.
The silica flour respectively quartz flour of Farsil type are SiO2 flours having an alkali metal oxide content or alkaline earth metal oxide content which is not greater than 1% by weight and which were obtained with the aid of a so-called sintering process and whose particle size lies between 15 0 and 100 ~m, preferably between 0 and 10 ~m. The silica flour of Farsil type respectively quartz flour of Farsil type may be prepared by a sintering process wherein quartz materials are heated for several hours to about 1400C to 1600C, cooled and comminuted (cf. French Patent Specifica-20 tion 1,288,904). (Suitable are e.g. the Grénette Farsil types 44 and 28 of the firm S.A.N.S.O.N., Cayeux-sur-Mer/
France.) A small particle size is necessary, among other reasons, to avoid damage to the screws of the extruder or injection molding machine because of the hardness of the silica flour. Unsuitable are, for example, silica flours of a particle size between 0 and 100 ~m which after grinding were calcined for 2 hours at 1000C (e.g. the types W 6, W 12 and Sikron(R) 100 of Quarzwerke GmbH, Cologne) ~ LeA 14,993-Ca -5-, . . .
10458~D8 Any suitable pigment which is hydrophobic and inert to high-molecular-weight aromatic polycarbonates, for example TiO2, Cr203, in the form of powder may be used.
A~ suitable process may be used to disperse the silica flour respectively quartz flour of Farsil type in the preparation of the compositions, according to the high-molecular-weight aromatic polycarbonates such as, for example:
1. The silica flour respectively quartz flour and, optionally, the pigment may be introduced into the polycarbonate melt.
Mixing may be effected by any known process and the mixture may be extruded or injection molded according to any known process.
2. The silica flour respectively quartz flour and, optionally, the pigment may be introduced into a solution of the poly-carbonate, the solvent evaporated as usual from the solution and the residue dried.
The compositions provided by the invention may be -used in the elctrical filed, especially for the production of articles which carry ~oltage-conducting parts or come into -contact with voltage-conducting parts.
The following Examples illustrate the improved tracking resistance, with respect to a glass reinforced polycarbonate composition, and the good physical-technological properties picture of the compositions provided by the invention and simultaneously show that other silica flours are not as well suited in this respect. I
.' -'.
Le A 14 993 - 6 -,- . -, i 1~458C~8 Example 1 About 40~ by weight of silica ~lour is added to a high-molecular-weight polycarbonate melt based on Bisphenol A
(prepared according to the process of interface condensation with phosgene, and having a rel. solution viscosity of 1.320) with the aid of a twin screw extruder. The polycarbonate bristles obtained are drawn off via a water- and air-cooled through and immediately granulated.
.. , : . ':
Example 2 According to the process described under Example 1, a mixture of 20% by weight of silica flour and 10% by weight of pigment is added to the polycarbonate.
Some selected values of the physical~technological properties in dependence on the silica flour type used and, in some cases, pigment addition, are recorded in the following Table:
Example 3 - The polycarbonate of Example 1 containing in`stead of 40 % by weight of silica flour 20 % by w~ight of milled glass i~iber.
I!
LeA 14,993 -7-,~ ~
... . . ~, 1~)45808 ~n _ _ u~
~ S h ~ O 1~ 0 0 a~ . ~
., ~ O
.. _ _ ~
,J rl ~d ' ~J~ ~.
,n ~ ~ s: ~ o ~D ~0 O U~ O ~
v~ aR h~R~ ~ . ,1 ,1 ~ o O td O ,~ u~ ~
O
. _ .
~: -l .Y O o u~ 1~ ou~ --/ ' O
o 3-, o -I ~oIn , O ~ ~ ,~
.. , V
~S~ o o ~ ' O O 1` 0 0 ~ O H + I ~) ~:
O '-I ~1 ~ U') O O ~ D h :
_ .. . 3 ~
~ ~ ' _~ ',' O t~ ~ O ~ D ~ '5i''' ` h ~1 ;
a p, ~ ", _l :'' '' h ~o ~ a~ ~a ~:
H a a H H H E~ ~ aJ O `, ~` ~ ' O i~
~ U ., D ~ Y ~ U
,...................................... ,~ ....
.C ,~ , h ~ u~ aJ ~ o , tq o ~ U ~ ~ h ~q O O ~ ~ g O~ î~
~ .rl~rl C) (~ r~ _ : '.. ~ .
r-~ tJ\ ~ ~ ,:
U ~ R ~ 0 ~ h ~ O~, !4 / ~ . ~
~: '' :-, LeA 14,993 -8- ~ ~ ~
~,. . "' . , , .. . . . , . : ~ , 16~45808 . Farsil-44 has the following chemical analysis and the .:
. .ollowing particle sizes. ~ .
.. Farsil-44 100 % finer than 60 Micron . 96 % finer than 40 Micron . 92 % finer than 28 Micron 84 % finer than 20 Micron 60 % finer than 10 Micron 34 % ~iner than 5 Micron 26 % finer than 3 Micron 14 % finer than 2 Micron 10 % finer than l Micron :. .. , . _ .
Chemical Analysis: SiO2 : 99.03% Al2O3 : 0-18% :
Fe2O3 : 0.02~ CaO : 0.5 % :
MgO : 0.I % Na2O : 0.07%
. 10 K2O : 0.03% . -t'' Although the invention is described in detail for ~j the purpose of illustration it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
', '' : ., . ' ' ' ' ' ' ' ' ..
~ ~ .
Le A 14 993 - 9 - :
.
( - ,, : '.
.
Additional aromatic bis-hydroxy compounds suitable for the preparation of the polycarbonate are described in U. S. Patents 3,028,365; 2,999,835; 3,148,172; 3,271,368;
2,970,137; 2,991,273; 3,271,367; 3,280,078; 3,014,891; and 2,999,846.
The silica flour respectively quartz flour of Farsil type are SiO2 flours having an alkali metal oxide content or alkaline earth metal oxide content which is not greater than 1% by weight and which were obtained with the aid of a so-called sintering process and whose particle size lies between 15 0 and 100 ~m, preferably between 0 and 10 ~m. The silica flour of Farsil type respectively quartz flour of Farsil type may be prepared by a sintering process wherein quartz materials are heated for several hours to about 1400C to 1600C, cooled and comminuted (cf. French Patent Specifica-20 tion 1,288,904). (Suitable are e.g. the Grénette Farsil types 44 and 28 of the firm S.A.N.S.O.N., Cayeux-sur-Mer/
France.) A small particle size is necessary, among other reasons, to avoid damage to the screws of the extruder or injection molding machine because of the hardness of the silica flour. Unsuitable are, for example, silica flours of a particle size between 0 and 100 ~m which after grinding were calcined for 2 hours at 1000C (e.g. the types W 6, W 12 and Sikron(R) 100 of Quarzwerke GmbH, Cologne) ~ LeA 14,993-Ca -5-, . . .
10458~D8 Any suitable pigment which is hydrophobic and inert to high-molecular-weight aromatic polycarbonates, for example TiO2, Cr203, in the form of powder may be used.
A~ suitable process may be used to disperse the silica flour respectively quartz flour of Farsil type in the preparation of the compositions, according to the high-molecular-weight aromatic polycarbonates such as, for example:
1. The silica flour respectively quartz flour and, optionally, the pigment may be introduced into the polycarbonate melt.
Mixing may be effected by any known process and the mixture may be extruded or injection molded according to any known process.
2. The silica flour respectively quartz flour and, optionally, the pigment may be introduced into a solution of the poly-carbonate, the solvent evaporated as usual from the solution and the residue dried.
The compositions provided by the invention may be -used in the elctrical filed, especially for the production of articles which carry ~oltage-conducting parts or come into -contact with voltage-conducting parts.
The following Examples illustrate the improved tracking resistance, with respect to a glass reinforced polycarbonate composition, and the good physical-technological properties picture of the compositions provided by the invention and simultaneously show that other silica flours are not as well suited in this respect. I
.' -'.
Le A 14 993 - 6 -,- . -, i 1~458C~8 Example 1 About 40~ by weight of silica ~lour is added to a high-molecular-weight polycarbonate melt based on Bisphenol A
(prepared according to the process of interface condensation with phosgene, and having a rel. solution viscosity of 1.320) with the aid of a twin screw extruder. The polycarbonate bristles obtained are drawn off via a water- and air-cooled through and immediately granulated.
.. , : . ':
Example 2 According to the process described under Example 1, a mixture of 20% by weight of silica flour and 10% by weight of pigment is added to the polycarbonate.
Some selected values of the physical~technological properties in dependence on the silica flour type used and, in some cases, pigment addition, are recorded in the following Table:
Example 3 - The polycarbonate of Example 1 containing in`stead of 40 % by weight of silica flour 20 % by w~ight of milled glass i~iber.
I!
LeA 14,993 -7-,~ ~
... . . ~, 1~)45808 ~n _ _ u~
~ S h ~ O 1~ 0 0 a~ . ~
., ~ O
.. _ _ ~
,J rl ~d ' ~J~ ~.
,n ~ ~ s: ~ o ~D ~0 O U~ O ~
v~ aR h~R~ ~ . ,1 ,1 ~ o O td O ,~ u~ ~
O
. _ .
~: -l .Y O o u~ 1~ ou~ --/ ' O
o 3-, o -I ~oIn , O ~ ~ ,~
.. , V
~S~ o o ~ ' O O 1` 0 0 ~ O H + I ~) ~:
O '-I ~1 ~ U') O O ~ D h :
_ .. . 3 ~
~ ~ ' _~ ',' O t~ ~ O ~ D ~ '5i''' ` h ~1 ;
a p, ~ ", _l :'' '' h ~o ~ a~ ~a ~:
H a a H H H E~ ~ aJ O `, ~` ~ ' O i~
~ U ., D ~ Y ~ U
,...................................... ,~ ....
.C ,~ , h ~ u~ aJ ~ o , tq o ~ U ~ ~ h ~q O O ~ ~ g O~ î~
~ .rl~rl C) (~ r~ _ : '.. ~ .
r-~ tJ\ ~ ~ ,:
U ~ R ~ 0 ~ h ~ O~, !4 / ~ . ~
~: '' :-, LeA 14,993 -8- ~ ~ ~
~,. . "' . , , .. . . . , . : ~ , 16~45808 . Farsil-44 has the following chemical analysis and the .:
. .ollowing particle sizes. ~ .
.. Farsil-44 100 % finer than 60 Micron . 96 % finer than 40 Micron . 92 % finer than 28 Micron 84 % finer than 20 Micron 60 % finer than 10 Micron 34 % ~iner than 5 Micron 26 % finer than 3 Micron 14 % finer than 2 Micron 10 % finer than l Micron :. .. , . _ .
Chemical Analysis: SiO2 : 99.03% Al2O3 : 0-18% :
Fe2O3 : 0.02~ CaO : 0.5 % :
MgO : 0.I % Na2O : 0.07%
. 10 K2O : 0.03% . -t'' Although the invention is described in detail for ~j the purpose of illustration it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
', '' : ., . ' ' ' ' ' ' ' ' ..
~ ~ .
Le A 14 993 - 9 - :
.
( - ,, : '.
.
Claims (12)
1. A composition comprising (a) a high molecular weight aromatic polycarbonate and (b) about 10 to 60 weight percent, based on the high molecular weight polycarbonate, of silica flour of a maximum particle size less than 100 µm and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent, based on silica flour, wherein the flour is prepared by heating quartz materials to between 1400°C and 1600°C for several hours, cooling them and comminuting them to size.
2. The composition of Claim 1 containing from about 20 percent by weight to about 40 percent by weight silica flour with respect to the weight of the polycarbonate.
3. The composition of Claim 1 containing a hydrophobic pigment which is inert to the high molecular weight aromatic polycarbonate in an amount of about 2 percent by weight to about 20 percent by weight with respect to the polycarbonate.
4. The composition of Claim 3 wherein the amount of hydrophobic inert pigment is about 5 percent by weight to about 10 percent by weight with respect to the polycarbonate.
5. The polycarbonate composition of Claim 3 wherein the pigment is titanium dioxide.
6. The polycarbonate composition of Claim 3 wherein the pigment is chromium trioxide.
7. An electrical insulator shaped from the composition of Claim 1 and having a minimum tracking resistance of 260 ? 20 volts and a minimum impact strength of about 70 kpcm/cm2.
8. An electrical insulator shaped from the composition of Claim 3 and having a minimum tracking resistance of 260 ? 20 volts and a minimum impact strength of about 60 kpcm/cm2.
9. A process for improving the resistance of a high molecular weight, aromatic polycarbonate to leakage current comprising dispersing in the polycarbonate about 10 to 60 weight percent, based on the weight of the polycarbonate, of a silica flour having a particle size of less than 100 µm and an alkali metal oxide or alkali earth metal oxide content of less than 1 weight percent based on the silica flour wherein the flour is prepared by heating quartz materials to between 1400°C and 1600°C
for several hours, cooling them and comminuting them to size.
for several hours, cooling them and comminuting them to size.
10. The process of Claim 9 wherein a hydrophobic pigment inert to the polycarbonate is dispersed in the polycarbonate.
11. The process of Claim 9 wherein about 20 to 40 weight percent of silica flour, based on the weight of the polycarbonate, is used.
12. A composition comprising (a) a high molecular weight, aromatic polycarbonate and (b) about 10 to 60 weight percent, based on the high molecular weight aromatic polycarbonate, of a silica flour having a particle size below 100 µm which before grinding was heated for several hours to between about 1400°C and 1600°C, and containing about 99.03% by weight of SiO2, about 0.18% by weight of Al2O3 about 0.02% of Fe2O3, about 0.5% by weight of CaO, about 0.1% by weight of MgO, about 0.07% by weight of Na2O and about 0.03% of K2O.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19732324427 DE2324427C3 (en) | 1973-05-15 | 1973-05-15 | Polycarbonate compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1045808A true CA1045808A (en) | 1979-01-09 |
Family
ID=5880954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA195,849A Expired CA1045808A (en) | 1973-05-15 | 1974-03-25 | Polycarbonate composition having improved electrical tracking resistance |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS554145B2 (en) |
| BE (1) | BE812887A (en) |
| CA (1) | CA1045808A (en) |
| DE (1) | DE2324427C3 (en) |
| FR (1) | FR2229729B1 (en) |
| GB (1) | GB1430034A (en) |
| IT (1) | IT1003921B (en) |
| NL (1) | NL7404157A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4478964A (en) * | 1981-06-05 | 1984-10-23 | Mobay Chemical Corporation | Polycarbonate-silicate compositions |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS588941Y2 (en) * | 1975-09-18 | 1983-02-17 | 三菱電機株式会社 | Kikanten Kayo Hiden Kino Hiden Cap |
| US4070330A (en) * | 1976-01-23 | 1978-01-24 | Mobay Chemical Corporation | High impact mineral filled polycarbonates |
| JPS52139940U (en) * | 1976-04-17 | 1977-10-24 | ||
| JPS53160610U (en) * | 1977-05-23 | 1978-12-15 | ||
| JPS543212A (en) * | 1977-06-10 | 1979-01-11 | Hitachi Ltd | Internal combustion engine distributor |
| JPS6134864Y2 (en) * | 1978-04-25 | 1986-10-09 | ||
| US4460733A (en) * | 1982-11-29 | 1984-07-17 | Mobay Chemical Corporation | Polycarbonate compositions having low gloss values |
| WO2013079599A1 (en) * | 2011-11-30 | 2013-06-06 | Bayer Intellectual Property Gmbh | Polycarbonate compositions having an improved surface |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1366532A (en) * | 1962-08-22 | 1964-07-10 | Ozalid Co Ltd | Process for treating polyesters and polycarbonates surfaces, composition for its implementation and resulting products |
| FR1361439A (en) * | 1963-04-08 | 1964-05-22 | Organico | Improved thermoplastic materials and their manufacturing process |
| DE1285175B (en) * | 1964-10-01 | 1968-12-12 | Gen Electric | Use of polycarbonates for film production |
-
1973
- 1973-05-15 DE DE19732324427 patent/DE2324427C3/en not_active Expired
-
1974
- 1974-03-25 CA CA195,849A patent/CA1045808A/en not_active Expired
- 1974-03-27 IT IT4972074A patent/IT1003921B/en active
- 1974-03-27 BE BE142493A patent/BE812887A/en unknown
- 1974-03-27 NL NL7404157A patent/NL7404157A/xx unknown
- 1974-03-28 JP JP3405274A patent/JPS554145B2/ja not_active Expired
- 1974-03-28 FR FR7410895A patent/FR2229729B1/fr not_active Expired
- 1974-03-29 GB GB1402474A patent/GB1430034A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4478964A (en) * | 1981-06-05 | 1984-10-23 | Mobay Chemical Corporation | Polycarbonate-silicate compositions |
Also Published As
| Publication number | Publication date |
|---|---|
| NL7404157A (en) | 1974-11-19 |
| BE812887A (en) | 1974-09-27 |
| DE2324427B2 (en) | 1980-11-20 |
| DE2324427A1 (en) | 1974-12-05 |
| GB1430034A (en) | 1976-03-31 |
| IT1003921B (en) | 1976-06-10 |
| FR2229729A1 (en) | 1974-12-13 |
| JPS503459A (en) | 1975-01-14 |
| JPS554145B2 (en) | 1980-01-29 |
| DE2324427C3 (en) | 1982-01-14 |
| FR2229729B1 (en) | 1978-01-06 |
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