CA2077136A1 - Alkyl (meth)acrylate-maleic anhydride copolymer-modified bitumen - Google Patents
Alkyl (meth)acrylate-maleic anhydride copolymer-modified bitumenInfo
- Publication number
- CA2077136A1 CA2077136A1 CA002077136A CA2077136A CA2077136A1 CA 2077136 A1 CA2077136 A1 CA 2077136A1 CA 002077136 A CA002077136 A CA 002077136A CA 2077136 A CA2077136 A CA 2077136A CA 2077136 A1 CA2077136 A1 CA 2077136A1
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- Canada
- Prior art keywords
- meth
- amount
- maleic anhydride
- acrylates
- bitumen
- 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.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L95/00—Compositions of bituminous materials, e.g. asphalt, tar, pitch
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention provides a polymer-modified bitumeniferous composition containing polymer components in the amount of 0.5-50 wt.%, wherein 20-100 wt.% of the polymeric additive is a copolymer comprises of units of: C6-C28-alkyl (meth)acrylates in the amount of 80-99.9 wt.%, maleic anhydride in the amount of 0.1-20 wt.%, and other polymerizable compounds in the amount of 0-19.9 wt.%. The polymer-modified bitumens exhibit excellent and persistent homogeneity, high elastic resilience, and a good range of plasticity.
The present invention provides a polymer-modified bitumeniferous composition containing polymer components in the amount of 0.5-50 wt.%, wherein 20-100 wt.% of the polymeric additive is a copolymer comprises of units of: C6-C28-alkyl (meth)acrylates in the amount of 80-99.9 wt.%, maleic anhydride in the amount of 0.1-20 wt.%, and other polymerizable compounds in the amount of 0-19.9 wt.%. The polymer-modified bitumens exhibit excellent and persistent homogeneity, high elastic resilience, and a good range of plasticity.
Description
2~77~36 TITLE OF THE INVENTION
ALKYL (METH)ACRYLATE-MALEIC
ANHYDRIDE COPOLYMER-MODIFIED BITUMEN
BACKGROUND OF THE INVENTION
Field of the Inventlon:
The present invention relates to polymers based on .
polyalkyl (meth)acrylates, which may be used as upgrading agents for bitumen, and for bitumen modi~ied Witil such polymers, which has improved properties.
~escription of_th Backqround:
Bitumen, which is a mixture of essentially dif~erent hydrocarbons with varying contents of paraffinic, naphthenic, and aromatic hydrocarbons, has numerous uses as a consequence of its particular properties. Thus, it is used in producing road surfaces, as a sealing and gap-filling compound, as a coating, as a protectant for structures (possibly in the ~orm of roofing paper), or as a sealant against ground water.
The peculiar properties of the product (bitumen has elastic parameters in the low to zero range depending on the crude oil from which it is obtained) cause pavement layers produced with it to be brittle at low temperatures and ~o~t at higher temperatures.
Various additives, particularly polymers, have been employed to attempt to upgrade bitumen, particularly its ,~ .
-2 2 ~7 7 rheological properties, so that, e.g., asphalt, which is a mixture of bitumen and mineral.materials used particularly in road building, will have the raquisi.te stability and cold flexibility as well as durability under increasing traffic loads. Thus, addition o~ polymers can increase the so-called "plasticity range", whic~ is the difference between the softening point and the Fraass breaking point (DIN 52 103).
When polymer addition results in a r~duced F~aass breaking point and an increased ductility (DIN 52 013), this indicates that the modified material will display improved cold flexibility. The purpose of the polymer as a bitumen-additive is to alter the visco-elastic behavior of the bitumen, i.e., to increase its plasticity range and improve its elastic resilience.
Polymers which have been studied as bitumen upgrading agents include no~ only natural and synthetic rubbers but also duroplastic resins and thermoplastics (Koerner et al., 1977 Plaste und Kautschuk, 24, 475-478). The principal polymeric bitumen-upgrading agents used industrially, heretofore, are styrene-butadiene copolymer (SB), EPDM copolymer, ethylene-vinyl acetate (EVA) copolymer, and, particularly for industrial bitumen, atactic polypropylene. Commercial PmBs include Caribit~ (SB, Shell), Olexobit~ (EPDM, BP), and Styrelf~ (SB, Elf).
Polymers based on acrylic acid esters and methacrylic acid esters, particularly polymers of alkyl methacrylic acid -3~ &
esters (PAMA), have been described as upgrading agents for bitumen. These polymers have ~ot fol~nd wide use i~ the industry, however, despite the fact that they satisfy a number of requirements as additives. The principal reason is that they do not sufficiently improve the elastic resilience of the final elastomer-modified bitumen product.
Thus, U.S. Pat. 2,420,082 describes bitumeni~erous mixtures containing bitumen and 2-5~ of poly-C8-C~0-alkyl methacrylates of unspeci~ied molecular weights. The ductility of the bikumen is improved.
U.S. Pat. 2,828,429 disclose~ bitumeniferous mixtures containing rubber and poly-C8-C~-alkyl (meth)acrylates, each being present in the amount of 0.01-0.5%. The mixtures have improved ductility. The PAMAs here have molecular weights of 5,000 to 500,000.
Ger. AS 12 40 773 and OS 23 31 727 describe bitumeniferous binders for road surfaces which binders are also upgraded with alkyl methacrylate polymers; however, detailed data on the polymers are lacking.
Polyalkyl (meth)acrylates and copolymers of alkyl (meth)acrylates are proposed as bitumen upgrading agents in Ger. OS 25 09 473. A mixed polymer is described, which is solid at normal temperature and non-sticky, and having a molecular weight of 50,000 to 500,000, containing alkyl (meth)acrylates with alkyl groups having > 6 C atoms, and further containing of units of acrylic acid or methacrylic 2~7~
acid in the ~mount of 3-20 wt.% and units of monomers-containing basic nitrogen, also in the amount of 3-20 w~.%.
Ger. OS 39 17 816 and 39 25 827 describe mixed polymers containing the same components but the amounts o~ the carboxylic acid units and the units of basic nitrogen compounds are each < 2.8 wt.%.
Jap. oS 52-141,829 discloses stagewise emulsion-polymerized additives, and PCT Pat. 88/07,067 disclos~s poly-C4-C20-alkyl methacrylates with molecular weights of c.
5,000 to c. l,000,000 which are contained in the modified bitumen in amounts of 0.01 wt.% to c. 10 wt.%. Poly Ca-C26-alkyl (meth)acrylates with molecular weights Mw > 106 are known as bitumen-modifying polymers from Ger. OS 39 17 815.
Olefinic copolymers, particularly containing units of acrylic acid and/or methacrylic acid as reactive comonomers, are described as additives ~or bitumeniferous materials in Ger. AS 11 88 807 and in PCT Pat. 87/04,174. Also, Jap. Pat.
62-79,268 discloses copolymers of isobutylene and/or styrene and/or lower acrylic acid esters with maleic acid or maleic anhydride.
Ionically crosslinked, substantially homogeneously distributed poly(meth)acrylate systems in bitumens may be obtained, according to Ger. Pat. App. P 40 06 499.9, in a two stage procedure by mixing-in acid-group-containing polymers and then mixing-in reactive metal compounds. Bitumens containing covalently crosslinked, homogeneously distributed poly(meth)acrylate systems are described in Ger. Pat. App. P
40 40 23~7. 1 In order for the polymeric additives to be industrially practical in bitumeniferous mixtures the polymeric additives must be oxidatively and thermally st:able, as well as being capable of being easily mixed into bitumen,lbPing compatible with various types of bitumen, and imparting stability to the bitumen-polymer mix ure over relatively long periods and at elevated temperatures.
The known polymeric bitumen additive~ sufficiently extend the "plasticity range" of bitumeniferous mixtures, including mineral-containing bitumeniferous mixtures; i.e., often the softening point and Fraass breaking point of such materials are favorably influenced by the known polymeric additives.
However, asphalts produced with bitumeniferous binders do not have adequate strength on aging or adequate elasticity (which parameters are determined by the elastic properties of the bitumen). An example of the effect of this in practice may be seen from the fact that quite often asphalt road surfaces are seriously deformed.
A particularly disadvantageous phenomenon in many types of bitumen is de-mixing with subsequent formation of polymer-rich and polvmer-depleted phases when state of the art bitumen additives are employed under hot storage conditions, i.e., the PmBs do not remain homogeneous and are not storage stabile.
.
~ 2~7~ ~
Thus,~a need exists for bitumen additives which are compatible with the widest possible variety of bitumen types and which are, therefor, widely usable, and which avoid the above disadvantages.
SUMMARY OF THE INVENT~ON
Accordingly, it is an ohject of the present invention to provide a polymer-modified bitumen which avoi~s the above disadvantages.
It is also an object of the present invention to provide a method of manufacturing polymer-modified bitumen which avoids the above disadvantages The above objects and others are provided by a polymer-modified bitumen which exhibits homogeneity, high elastic resilience, good cold flexibility and high thermal stability, which contains polymer components in the amount of about 0.5-50 wt.~, at least 20 wt.~ of which components contain polyalkyl (meth)acrylates, and wherein the polyalkyl (meth)acrylates contain units of C6-~8 ~meth)acrylates in the amount of about 80 to 99.9 wt.%, maleic anhydride in the amount of about 0.1 to 20 wt.%, and one or more other components with not more than one polymerizable double bond, in the amount of 0 to 19.9 wt.%, and wherein the polyalkyl (meth)acrylates are uniformly distributed in the bitumen.
-7- 2~77~
DETAILED D~SCRIP~ION OF TH.E E'REFERRED EMBODIMEN,TS
The present invention is prediaat~d upon the need to obtain homogeneous, storage-stabile polymer-modified bitumens (PmBs) modified with poly(meth)acrylates, which PmBs retain their homogeneity a~ter storage at elevated temperature~ and which, in general, have good mechanical and thermal properties. In particular, there is a need for poly(meth)acrylate modifying agents which exhibit homogeneity for virtually all types of bitumen as well~ as good technical behavior.
Surpri~ingly, it has been discovered that PmBs which have good homogeneity, and, more importantly, homogeneity which is durable, i.e., such that the PmB survives hot storage without de-mixing, can be prepared if cert~in polyalkyl (meth~acrylates are used containing maleic anhydride as a comonomer, wherewith the elastic and thermal properties of the bitumen, and thus of bitumeniferous compositions, are substantially and surprisingly improved, and the practical requirements posed are satisfied.
It is quite surprisiny that such PmBs, with homogeneity which is much improved, in degree and stability, can be provided as compared to PmBs containing merely ordinary PAMAs (which are described as bitumen~modifying agents in PCT Pat.
88/07,067 and Ger. OS 39 17 825). This is accomplished by using copolymers of long-chain alkyl (meth)acrylates and maleic anhydride, i.e., PAMAs containing maleic anhydride as a -8~ 7 ~ ~} 1~
comonomer~ Compared to the ionical:ly or covalently crosslinked and h~mogeneously distr.ibuted poly(meth)acrylate systems in bitumens according to the state of the art, the polymeric additives of the present invention are distinguished by their relatively simple structure and ease of use.
In general, the present invention provides a polymer-modified bitumen (PmB) which has homogeneity (i~e., good stability to de-mixing under hot storage), high elastic resilience, good cold flexibility, and high thermal stability, containing polymer components in the amount of 0.5 50 wt.%, at least 20 wt.% of which components comprise polyalkyl (meth)acrylates (PAMAs); wherein the PAMAs contain units of C6-C2~-alkyl (meth)acrylates in the amount of 80-99.9 wt.%, maleic anhydride in the amount of 0.1-20 wt.%, and one or more other compounds with not more than one polymerizable double bond, in the amount of 0-19~9 wt.%, and said PAMA5 are uniformly.distributed in the bitumen.
The molecular weights Mw of the C~-C28-alkyl (meth)acrylate - maleic anhydride copolymers are advantageously in the range > 30,000 up to c. 1,500,000. Moreover, the use of the maleic anhydride - olefin copolymers has further surprisingly favorable effects on the mechanical properties of the PmBs.
The alkyl (meth)acrylate copolymers and/or mixtures of copolymers, of which the compositions according to the invention are comprised, can be added to the bitumen or 9~
bitumeniferous mixture in the form of a solution of the additives, e.g.! in a suitable mineral oil, or in pure form.
Although it is known that improvsd cold flexibility (as indicated by Fraass breaking point and ductility) in PmBs can be obtained by adding polyalkyl (met:h)acrylates with molecular weights in the range 50,000 to c. 1,ooo,000; the elastic resilience and homogeneity obtained are inadequate, wherewith persistent deformations occur in the bituminous composition products (e.g., sealing rings or road urfaces), and these deformations will present substantial risks, e.g. to traffic safety. The ~erman requirements of the Technical Terms of Delivery for finished PmB, "Tl PmB 88", Part 1, Version of Dec 30, 1988, require elastic resilience of at least 50% for the various types of PmBs.
To test the elastic properties of finished elastomer-modified bitumen, the test of elastic resilience (ER) according to the sheared fiber method, in a ductilometer, based on the method of DIN 52,013, is carried out at 25C, as ~ollows:
At variance from DIN 52,013, the test bodies are drawn to a fiber length of only 2Q cm, and after termination of the advance the fibers arP cut in the middle into two sheared fiber halves, within 10 sec thereafter, with a scissors. The elastic resilience is defined as the distance between the two sheared fiber halves which is measured after 30 min. It i5 given in percent of the original elongation.
-10~
To test the homogeneityj the stability of finished PmBs to de-mixing under hot storage is determined by the following method, the so-called "tube method" ("Tl PmB").
Approximately 75 g PmB free of bubbles is poured in such a manner as to avoid bubbles into arl unpainted aluminum tube of diameter 3 cm and cylindrical height 16 cm, until the tube is filled to 2/3 of its height. Before the test material has completely cooled, the open ends of the tube are pressed together and folded over multiple times-to produce a hermetic seal, in such a way that no air is included. The tube thus sealed air-free and~air-tight is stored vertically for 3 days at 180C. After cooling to room temperature the tube is cooled by suitable means until the test material can be peeled or cut away from the aluminum metal. The test sample is cut into thirds based on height (i.e., bottom third, middle third, and top third). The ring and sphere softening points (DIN
52,011) are determined on the bottom and top sample pieces~
At variance with DIN 52,011, sample sizes of 25 g bitumen were regarded as sufficiently large for the determination of the softening.
A PmB is regarded as stabile to de-mixing if th~
difference in the ring and sphere softening points, respectively, between the bottom and top third pieces, is less than 2 K.
The Examples with comparison values according to the state of the art llelp to demonstrate the high elastic 2 ~ fi resilience and high homogeneity (i.e., good storage stability) of the inventive PmBs. The measuring methods and the tables of values are presented in Part B o~ the experimental section.
The structure of the present copolymeric additives with (meth)acrylic acid esters provides good solubility, i.e., easy miscibility into practically all types of bitumens; further, good cold flexibility; and good oxidation resistance of the present PmBs. The present PmBs are further distinguished by high ductility and broad "plasticity ranges", i.e., temperature differences between the Fraass breaking point and the softening point, measured on rings and spheres.
To produce the alkyl (meth)acrylate copolymers employed according to the present invention, long-chain alkyl esters of acrylic acid and/or particularly methacrylic acid are used as monomers wherein the alkyl groups in the ester functions have 6-28 C atoms, preferably 8-20 C atoms, particularly preferably 10-18 C atoms.
Examples of such esters are n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, isodecyl acrylate, isodecyl methacrylate, dodecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, eicosyl methacrylate, and tricosyl methacrylate, wherewith preferably the long-chain alcohols used to produce the esters are synthetic alcohols, which generally are in the form of mixtures of different alcohols, particularly in the C8-C26 range. Alcohols of this .
.
-12~
type are commercially~available, e.g.,~ under the trade names Lorol~, Alfol~, Dobanol~, and Behenyl-SR~. An exampl~ of a technical alcohol which can be used to manufacture isodecyl methacrylate is a mixture of isomeric isodecyl alcohols with mean C-number (C) = 9.9-10.3.
The prssent bitumen-modifying polyalkyl (meth)a~rylates containing maleic anhydride as a comonomer contain 80-99.9 wt.%, preferably 90-99.5 wt.%, particularly preferably 95-99 wt. %, of units of long-chain C6-C28~alkyl esters of acrylic acid, and/or preferably methacrylic acid, wherewith advantageously these esters may contain mixtures of various C6-C28 -alkyl esters. The units of the comonomer maleic anhydride are present in the amount of 0.1-20 wt.%, preferably 0.5-1o wt~%, particularly preferably 1-5 wt.%, in the copolymer or in the copolymers to be mixad.
In addition to the essential monomers contained in the present copolymeric additive, the additive may contain units of one or more other copolymerizable compounds having a double bond, in the amount of 0-19.9 wt.%, preferably 0-10 wt.%.
Examples of nonessential but useful monomers for the manufacture of the copolymers to be used according to the invention are acrylates and/or methacrylates of Cl-C5-alcohols, e.g., methyl methacrylate, isobutyl methacrylate, n-butyl acrylate, isoamyl methacrylate, and n-pentyl acrylate; also cyclopentyl methacrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl methacrylate, and multiply alkoxylated 2 ~
methacrylate esters; further, acry~ic acid, methacrylic acid, acrylonitrile, acrylamide, methaerylamlde, styrene, vinyl acetate, and particular~v nitrogen-containing, basic, polymerizable compounds, units of which are pre~erably contained in the polyalkyl (meth)acrylate addi ive in the amount of O-lO~wt.%.. . .
As basic monomers, for example, are those with tertiary amino- or amido groups, or with basic het~rocyclic groups.
Monomers with a ba.~ic nitrogen atom are, among others, dialkylaminoalkyl esters or dialkylaminoalkyl amides of (meth)acrylic acid, particularly those with a total of 7-16 C
atoms; and corresponding N-alkyl lmeth)acrylamides. Examples are dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, N-methyl (meth?acrylamide, dimethylaminoethyl (meth)acrylamide, and esters or amides of the above types but with the dimethylamino group replaced with a diethylamino, dipropylamino, dibutylamino, methylethylamino, methylbutylamino, morpholino, or piperidino group. Examples of other suitable nitrogen containing monomers are vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylimidazoline, vinylpyrazolone, vinylpiperidin~, and the (meth)acrylate esters of imidazolylalkanols or imidazolinylalkanols. For mixin~ into the bitumens the polymer components which serve to improve homogeneity and resilience, the present polyalkyl (meth)acrylates may be added to the bitumen while in solution, .' ~
-' ' , -14~
preferably in a suitable mineral oil, e.g., a highly viscous naphthene-based lubri~ating oi~, or possibly in aqueous emulsion or in pure form. According:Ly, the copolymers of the present invention may be manufactured according to the known, customarv methods via primarily radical polym~rization of the monomsrs in solution or in emulsion, or possibly in the mass (see Rauch-Puntigam, H., and Voelker, Th., 1967, "Acryl- und Methacrylverbindungen", pub. Springer-Verlag, Berlin, 1967, particularly pp. 203, 207, 230-233, 238, 327).
~ he molecular weight Mw of the inventively employed polyalkyl (meth)acrylates should be > 10,000, preferably >
30,000. Mw values up to c. 1,500,000 can be achievad. The Mw is controlled, as a rule, by the amount of the polymerization initiator in relation to the polymerizable monomers, or in relation to the use of a regulator, e.g., an alkyl mercaptan.
Known methods may be used, such as that of Rauch-Puntigam, ~., loc. cit. The molecular weight, Mw, in g/mol oP the polymer obtained, may be determined by the method of light scattering ("Ullmanns Encyklopaedie der technischen Chemie", 4th Ed., V. 15, pp. 385-287), or may be estimated from the viscosity relation ~p/c = 0.0156 x Mw0~5 , with the viscosity being measured according to DIN 7745 at 20C with chloro~orm as the solvent.
-15- 2 ~
For modi~ying the bitumens accc~rding to the present invention, the alkyl (meth)acrylates copolymerized with maleic anhydride, with the said copolymers having molecular weights preferably ~ lo,oO0, are added in ~he amount of 0.5-50 wt.%, preferably 0.5-20 wt.%, particularly preferably 1-15 wt.~, and more preferably 2-10 wt.%. The amount o~ modifying copolymer added depends on the intended use of the resulting PmB.
In addition to the alkyl (meth)acrylates copolvmerized with maleic anhydride, which copolymers are essential according to the present invention, the present PmBs may contain other known polymeric compounds, as improvers for bitumeniferous binders and mixtures. Examples are polyoleins (e.g., polyethylene and polypropylene), ethylene-vinyl acetate copolymers, or ABS copolymers, wherewith the ratio of alkyl (meth)acrylate copolymer to these other polymers may be 1:0 to 1:4, by weight. According to the invention, in this category the use of olefin copolymers modified with maleic anhydride is advantageous.
The alkyl (meth~acrylates copolymerized with maleic anhydride, after said copolymers are mixed into bitumen compositions, yield PmBs according to the present invention which are homogeneous according to tests (tube test) conducted after storage at 180C. The PmBs have elastic resilience up to c. 56-90%, as compared to values o~ c. 30-55% obtained according to the state of the art.
-16- 2~ 3~
The term "bitumen" in-th~ context of the present invention should be understood to mean any and all bitumens usable, e~g., in roadbuilding or roofing, or as a casting compound, sealing compound, or coating composition.
In the Examples hereinbelow, there are descriptions of the manufacture of the alkyl (meth)acrylates copolymerized with maleic anhydride, the manufacture of the inventive bitumen-polymer mixtures (PmBs), and the properties of the PmBs. Corresponding compari.son examples according to the state of the art are presented.
The present invention will be further illustratad by these Examples, whioh are not intended to be limitative but are provided solely ~or purposes of illustration.
Examples:
A) Synthesis of the Polymers:
1. Synthesis of the maleic anhydride - alkyl methacrylate copolymers. Examples 1-7:
In a 4 L 4-neck round-bottomed flask with a sword shaped stirrer, a re~lux condenser, and an internal thermometer/ 1000 g isodecyl methacrylate and maleic anhydride in the specified weight ratios, and 500 or 180 g (Example 3 or 5) naphthene-based oil, were heated to 75C under stirring. By passage of N2 the solution was freed ofloxygen within 1 hr. Then the polymerization was initiated with 0.2 g tert~butyl pivalate and 0.2 g tert-butyl perbenzoate. After 1 hr the temperature , -17~ 3 ~
was increased to 130C, and in Examples 3 and 5 an additional 320 y oil was added as a diluent. '; hr after the start of the reaction, 1 g tert-butyl perbenzoate was added for after-pol~merization, and an additional 500 g oil was added as a diluent.
The total duration of the polymeri~ation was 16 hr. The product was a clear, reddish brown, viscous solution with 50 wt.% polymer content. As a rule, conversion was > 97%.
Comparative_E _ e ~ 1:
The manufacturing method was analogous to that of Example 1, but without maleic anhydride.
=
comparative Examples 2 and 3:
In a 1 L ~ neck round-bottomed flask with a sword-shaped stirrer, a reflux condenser, and an internal thermometer, 500 g toluene, 52~8 g methyl acrylate or n-butyl acrylate, and 2.8 g maleic anhydride were heated to 70C, under stirring. A~ter this temperature was reached, the reaction was initiated with 0.11 g tert-butyl perpivalate. Then ~22.2 g methyl acrylate or n-butyl acrylate, 22.2 g maleic anhydride, and 1.33 g tert-butyl perpivalate were added portionwise over a period of 3 hr. 3 hx after completion of the additions, 1.0 g tert-butyl perpivalate was added for after polymerization.
The total duration of the polymerization was lO hr. The -18 2~'7~
product was a clear, colorless, viscous solution with 50 wt.%
polymer content.
The polymer was isolated by evaporation concentration on a rotational evaporator, and was dr:ied 12 hr at 70C in a vacuum drying cabinet.
B) Manufacturin~ and estlnn of polymer-modified bitumens (PmBs):
General method of manufacturinq PmBs:
A commercially available standard bitumen was heated to 150C in a flask with a sword-shaped stirrer. At this temperature, the given additive as specified in Tables Z-4 was added in the amount indicated, in the form of a 50% polymer ~solution in oil. The mixture was stirred 1 hr. After this period, in every case the polymer had been completely mixed in, and the resulting PmB was homogeneous and smooth.
The following tests were performed on the PmBs:
i) Ductility according to DIN 52 013.
ii) Softening point, "RuX", according to DIN 52 011.
iii) Elastic resilience according to ~mB Tl 89*, Sec.
3.2.1.
iv) Homogeneity following hot storage at 180C (tube test), according to PmB Tl 89, Sec. 3.2.1.
(* PmB Tl 89 rapresents "Technische Lieferbedingung fuer polymermodifiziertes Bitumen 1989".) In Table 1, infra, the polymers which were synthesized (the inventive and the compari~on polymers) are described.
.~ , ' , ~ . ' ' -19- ~7~
Tables 2-4 pr~sent test results on the present PmBs, and PmBs 12-08-92 Table 5 presents t~st results on the ~M~ which PmBs were prepared according to the state of t:he art.
Table 1 .. _. _ _ ...
Amounts of th~ ~p/c Pol_m~r monomers u~d _ Solvent ~ml/g) Example 1 990 g i80_ ecyl methacrylate 1000 g oil 81 10 g mal~ic anhydride ~ , .
Example 2 980 g i~odecyl methacrylate ~ 78 20 g maleic anhydride ~
Example 3 _ 980 ~isodecyl ethacrylat~ 1000 g oil _ 114 ~*
_ ,_ .. - ....... _._ 20 g maleic anhydride ~ ____ Example 4 950 g isodecyl m~thacrylat~1000 g oil 70 ~ . _ . . _ _ .. ..
_ _ 50 g maleic anhydride _ ~
Example 5 950 g isodecyl methacrylato1000 g oil llO ~*
~. ..... __ . _ __ _ .
_ . 50 g maleic anhydride . . _ Example 6 925 g isodecyl methacrylate 1000 g o_l 49 75 g malelc anhydrid~ _ 2xample 7 _ 900 g i~odecy e _acrylate 1000 g oil 57 100 g maleic anhydride _ _ Comparison Example l 1000 g isod~cyl methacrylate 1000 g oil 91-. . _ -- - v.. ... _ .. ___ Comparison Example 2 475 ~ methyl acrylat~ 500 ~ toluene 41 . . . ~ 25 g maleic anhydride . ____ Compari~on Example 3 47S g butyl acrylat~500 g toluen2 46_ 25 g maleic anhydride _ - .. _____ _ ~ _ __ . -~ sp/c estimated in Chloroform (DIN 7745) ** Startconcentration of the monomers : 90 %
12.08.92 ' -20- 2 0 ~7 r~ fi Table 2 = . = _ _ =
Amount of Ductility Softening Elastic Homo-Bitumen Additive at 13C point "RuK" resilience geneity (cm) _ (C) (%)- -- (,~) 1000 9 _ ~ > 150 _ 48.9 19 920 g 80 g Exam~le 1 > 150 _ 65 1.2 --- ----TT _ _ _ 940 g 60 g Example 1 _ 72 960 g 40 g Example 1 _ _ 75 _ _ _ _ _ _ ~
920 g 80 g Example 2 > 100 43.8 68 1.6 940 g 60 g Example 3 150 44.2 59 0.4 920 g 80 g Example 4 > 150 _ 56 0.5 - . . ._ _ _ __ 940 g 60 g Example 5 150 _ 45.1 _ 59 1.3 920 g 80 g Comparison > 100 _ 31 2.2 Example 1 _ - -- . T _._ ___ ____. __ _ _ __ _ _ _ _ 940 g 60 g Compari~on > 100 _ 26 1.0 Example 1 _ - _ . . ~ . . _ .
Table 3: Bitumen 13 200 from a different German refinery = _ Amount of Ductility Softening Elastic Homo-Bitumen Additive at 13C point "RuX~ re~ilisnce geneity ~ _ .... _ ~cm) ~C) (-~) (C) 1000 g _ > 100 38.~ 25 . _ . .
940 g 60 g Example 3 > 150 _ 53 0.0 _ ._ _ . _ _ _ _ 940 g 60 g Exam~le 5 ~ 100 _ 58 0.4 _ _ _ _ ~ _ . _ T
.960 g 60 g Comparison > 150 _ 36 0.4 Example 1 __ _ _ -- ~ ~
-21- 2 ~
Table 4: Bitumen 8 80 from a different German refinery , .__ = - . _ _ _ . 1 Amount of ~uctility Softe~ing Elastic Homo-8itum0n Additive at 13C point "RuK" resilience geneity ¦- _ _ _ (cm) _ ( C) (~) - (c) 1000 g _ 47 47.9 13 _~ _ _ 940 g 60 g Example 5 > 150 49.7 52 _ - _ 970 g 30 g Example 5 77 53.1 53 0.4 (100% polymer) _ . _ ~. , _ 940 g 60 g Comparison > 150 _ 17 1.0 Example 1 . ... _ ... .. _ Table 5: Bitumen B 80 from a di~ferent German refinery . . -- -- -- . --Amount of Du~tility Softening Elastic Homo-Bitumen Additive at 13C point "RuR" r~ nce geneity _ . ~cm) (C) (~) ( C) _ 940 g 60 g Compari~on 90 44.5 24 1.2 Example 2 _ . _ _ 940 g 60 g Compari~on > 120 44.0 25 2.3 Example 3 _ _ From the characterization of the bitumen mixtures of composition according to Comparison Examples 2 and 3 (Table 5), it is clear that these compositions are inferior to the examples of the present invention in elastic resilience and in ductility. Even though maleic anhydride is used as a comonomer in amounts comparable to those used in the present examples, the properties shown in Table 5 are not superior to those of the bitumen mixtures prepared with the PAMA
homopolymer according to Comparison Example 1.
~ ~rl 7 ~ r~
~7~ ~h Having described the present invention, it will be readily appar~nt to one of ordinary skill in the art that many changes and modifications may be made to the above-described embodiments without departing from the spirit and scope of the present invention.
ALKYL (METH)ACRYLATE-MALEIC
ANHYDRIDE COPOLYMER-MODIFIED BITUMEN
BACKGROUND OF THE INVENTION
Field of the Inventlon:
The present invention relates to polymers based on .
polyalkyl (meth)acrylates, which may be used as upgrading agents for bitumen, and for bitumen modi~ied Witil such polymers, which has improved properties.
~escription of_th Backqround:
Bitumen, which is a mixture of essentially dif~erent hydrocarbons with varying contents of paraffinic, naphthenic, and aromatic hydrocarbons, has numerous uses as a consequence of its particular properties. Thus, it is used in producing road surfaces, as a sealing and gap-filling compound, as a coating, as a protectant for structures (possibly in the ~orm of roofing paper), or as a sealant against ground water.
The peculiar properties of the product (bitumen has elastic parameters in the low to zero range depending on the crude oil from which it is obtained) cause pavement layers produced with it to be brittle at low temperatures and ~o~t at higher temperatures.
Various additives, particularly polymers, have been employed to attempt to upgrade bitumen, particularly its ,~ .
-2 2 ~7 7 rheological properties, so that, e.g., asphalt, which is a mixture of bitumen and mineral.materials used particularly in road building, will have the raquisi.te stability and cold flexibility as well as durability under increasing traffic loads. Thus, addition o~ polymers can increase the so-called "plasticity range", whic~ is the difference between the softening point and the Fraass breaking point (DIN 52 103).
When polymer addition results in a r~duced F~aass breaking point and an increased ductility (DIN 52 013), this indicates that the modified material will display improved cold flexibility. The purpose of the polymer as a bitumen-additive is to alter the visco-elastic behavior of the bitumen, i.e., to increase its plasticity range and improve its elastic resilience.
Polymers which have been studied as bitumen upgrading agents include no~ only natural and synthetic rubbers but also duroplastic resins and thermoplastics (Koerner et al., 1977 Plaste und Kautschuk, 24, 475-478). The principal polymeric bitumen-upgrading agents used industrially, heretofore, are styrene-butadiene copolymer (SB), EPDM copolymer, ethylene-vinyl acetate (EVA) copolymer, and, particularly for industrial bitumen, atactic polypropylene. Commercial PmBs include Caribit~ (SB, Shell), Olexobit~ (EPDM, BP), and Styrelf~ (SB, Elf).
Polymers based on acrylic acid esters and methacrylic acid esters, particularly polymers of alkyl methacrylic acid -3~ &
esters (PAMA), have been described as upgrading agents for bitumen. These polymers have ~ot fol~nd wide use i~ the industry, however, despite the fact that they satisfy a number of requirements as additives. The principal reason is that they do not sufficiently improve the elastic resilience of the final elastomer-modified bitumen product.
Thus, U.S. Pat. 2,420,082 describes bitumeni~erous mixtures containing bitumen and 2-5~ of poly-C8-C~0-alkyl methacrylates of unspeci~ied molecular weights. The ductility of the bikumen is improved.
U.S. Pat. 2,828,429 disclose~ bitumeniferous mixtures containing rubber and poly-C8-C~-alkyl (meth)acrylates, each being present in the amount of 0.01-0.5%. The mixtures have improved ductility. The PAMAs here have molecular weights of 5,000 to 500,000.
Ger. AS 12 40 773 and OS 23 31 727 describe bitumeniferous binders for road surfaces which binders are also upgraded with alkyl methacrylate polymers; however, detailed data on the polymers are lacking.
Polyalkyl (meth)acrylates and copolymers of alkyl (meth)acrylates are proposed as bitumen upgrading agents in Ger. OS 25 09 473. A mixed polymer is described, which is solid at normal temperature and non-sticky, and having a molecular weight of 50,000 to 500,000, containing alkyl (meth)acrylates with alkyl groups having > 6 C atoms, and further containing of units of acrylic acid or methacrylic 2~7~
acid in the ~mount of 3-20 wt.% and units of monomers-containing basic nitrogen, also in the amount of 3-20 w~.%.
Ger. OS 39 17 816 and 39 25 827 describe mixed polymers containing the same components but the amounts o~ the carboxylic acid units and the units of basic nitrogen compounds are each < 2.8 wt.%.
Jap. oS 52-141,829 discloses stagewise emulsion-polymerized additives, and PCT Pat. 88/07,067 disclos~s poly-C4-C20-alkyl methacrylates with molecular weights of c.
5,000 to c. l,000,000 which are contained in the modified bitumen in amounts of 0.01 wt.% to c. 10 wt.%. Poly Ca-C26-alkyl (meth)acrylates with molecular weights Mw > 106 are known as bitumen-modifying polymers from Ger. OS 39 17 815.
Olefinic copolymers, particularly containing units of acrylic acid and/or methacrylic acid as reactive comonomers, are described as additives ~or bitumeniferous materials in Ger. AS 11 88 807 and in PCT Pat. 87/04,174. Also, Jap. Pat.
62-79,268 discloses copolymers of isobutylene and/or styrene and/or lower acrylic acid esters with maleic acid or maleic anhydride.
Ionically crosslinked, substantially homogeneously distributed poly(meth)acrylate systems in bitumens may be obtained, according to Ger. Pat. App. P 40 06 499.9, in a two stage procedure by mixing-in acid-group-containing polymers and then mixing-in reactive metal compounds. Bitumens containing covalently crosslinked, homogeneously distributed poly(meth)acrylate systems are described in Ger. Pat. App. P
40 40 23~7. 1 In order for the polymeric additives to be industrially practical in bitumeniferous mixtures the polymeric additives must be oxidatively and thermally st:able, as well as being capable of being easily mixed into bitumen,lbPing compatible with various types of bitumen, and imparting stability to the bitumen-polymer mix ure over relatively long periods and at elevated temperatures.
The known polymeric bitumen additive~ sufficiently extend the "plasticity range" of bitumeniferous mixtures, including mineral-containing bitumeniferous mixtures; i.e., often the softening point and Fraass breaking point of such materials are favorably influenced by the known polymeric additives.
However, asphalts produced with bitumeniferous binders do not have adequate strength on aging or adequate elasticity (which parameters are determined by the elastic properties of the bitumen). An example of the effect of this in practice may be seen from the fact that quite often asphalt road surfaces are seriously deformed.
A particularly disadvantageous phenomenon in many types of bitumen is de-mixing with subsequent formation of polymer-rich and polvmer-depleted phases when state of the art bitumen additives are employed under hot storage conditions, i.e., the PmBs do not remain homogeneous and are not storage stabile.
.
~ 2~7~ ~
Thus,~a need exists for bitumen additives which are compatible with the widest possible variety of bitumen types and which are, therefor, widely usable, and which avoid the above disadvantages.
SUMMARY OF THE INVENT~ON
Accordingly, it is an ohject of the present invention to provide a polymer-modified bitumen which avoi~s the above disadvantages.
It is also an object of the present invention to provide a method of manufacturing polymer-modified bitumen which avoids the above disadvantages The above objects and others are provided by a polymer-modified bitumen which exhibits homogeneity, high elastic resilience, good cold flexibility and high thermal stability, which contains polymer components in the amount of about 0.5-50 wt.~, at least 20 wt.~ of which components contain polyalkyl (meth)acrylates, and wherein the polyalkyl (meth)acrylates contain units of C6-~8 ~meth)acrylates in the amount of about 80 to 99.9 wt.%, maleic anhydride in the amount of about 0.1 to 20 wt.%, and one or more other components with not more than one polymerizable double bond, in the amount of 0 to 19.9 wt.%, and wherein the polyalkyl (meth)acrylates are uniformly distributed in the bitumen.
-7- 2~77~
DETAILED D~SCRIP~ION OF TH.E E'REFERRED EMBODIMEN,TS
The present invention is prediaat~d upon the need to obtain homogeneous, storage-stabile polymer-modified bitumens (PmBs) modified with poly(meth)acrylates, which PmBs retain their homogeneity a~ter storage at elevated temperature~ and which, in general, have good mechanical and thermal properties. In particular, there is a need for poly(meth)acrylate modifying agents which exhibit homogeneity for virtually all types of bitumen as well~ as good technical behavior.
Surpri~ingly, it has been discovered that PmBs which have good homogeneity, and, more importantly, homogeneity which is durable, i.e., such that the PmB survives hot storage without de-mixing, can be prepared if cert~in polyalkyl (meth~acrylates are used containing maleic anhydride as a comonomer, wherewith the elastic and thermal properties of the bitumen, and thus of bitumeniferous compositions, are substantially and surprisingly improved, and the practical requirements posed are satisfied.
It is quite surprisiny that such PmBs, with homogeneity which is much improved, in degree and stability, can be provided as compared to PmBs containing merely ordinary PAMAs (which are described as bitumen~modifying agents in PCT Pat.
88/07,067 and Ger. OS 39 17 825). This is accomplished by using copolymers of long-chain alkyl (meth)acrylates and maleic anhydride, i.e., PAMAs containing maleic anhydride as a -8~ 7 ~ ~} 1~
comonomer~ Compared to the ionical:ly or covalently crosslinked and h~mogeneously distr.ibuted poly(meth)acrylate systems in bitumens according to the state of the art, the polymeric additives of the present invention are distinguished by their relatively simple structure and ease of use.
In general, the present invention provides a polymer-modified bitumen (PmB) which has homogeneity (i~e., good stability to de-mixing under hot storage), high elastic resilience, good cold flexibility, and high thermal stability, containing polymer components in the amount of 0.5 50 wt.%, at least 20 wt.% of which components comprise polyalkyl (meth)acrylates (PAMAs); wherein the PAMAs contain units of C6-C2~-alkyl (meth)acrylates in the amount of 80-99.9 wt.%, maleic anhydride in the amount of 0.1-20 wt.%, and one or more other compounds with not more than one polymerizable double bond, in the amount of 0-19~9 wt.%, and said PAMA5 are uniformly.distributed in the bitumen.
The molecular weights Mw of the C~-C28-alkyl (meth)acrylate - maleic anhydride copolymers are advantageously in the range > 30,000 up to c. 1,500,000. Moreover, the use of the maleic anhydride - olefin copolymers has further surprisingly favorable effects on the mechanical properties of the PmBs.
The alkyl (meth)acrylate copolymers and/or mixtures of copolymers, of which the compositions according to the invention are comprised, can be added to the bitumen or 9~
bitumeniferous mixture in the form of a solution of the additives, e.g.! in a suitable mineral oil, or in pure form.
Although it is known that improvsd cold flexibility (as indicated by Fraass breaking point and ductility) in PmBs can be obtained by adding polyalkyl (met:h)acrylates with molecular weights in the range 50,000 to c. 1,ooo,000; the elastic resilience and homogeneity obtained are inadequate, wherewith persistent deformations occur in the bituminous composition products (e.g., sealing rings or road urfaces), and these deformations will present substantial risks, e.g. to traffic safety. The ~erman requirements of the Technical Terms of Delivery for finished PmB, "Tl PmB 88", Part 1, Version of Dec 30, 1988, require elastic resilience of at least 50% for the various types of PmBs.
To test the elastic properties of finished elastomer-modified bitumen, the test of elastic resilience (ER) according to the sheared fiber method, in a ductilometer, based on the method of DIN 52,013, is carried out at 25C, as ~ollows:
At variance from DIN 52,013, the test bodies are drawn to a fiber length of only 2Q cm, and after termination of the advance the fibers arP cut in the middle into two sheared fiber halves, within 10 sec thereafter, with a scissors. The elastic resilience is defined as the distance between the two sheared fiber halves which is measured after 30 min. It i5 given in percent of the original elongation.
-10~
To test the homogeneityj the stability of finished PmBs to de-mixing under hot storage is determined by the following method, the so-called "tube method" ("Tl PmB").
Approximately 75 g PmB free of bubbles is poured in such a manner as to avoid bubbles into arl unpainted aluminum tube of diameter 3 cm and cylindrical height 16 cm, until the tube is filled to 2/3 of its height. Before the test material has completely cooled, the open ends of the tube are pressed together and folded over multiple times-to produce a hermetic seal, in such a way that no air is included. The tube thus sealed air-free and~air-tight is stored vertically for 3 days at 180C. After cooling to room temperature the tube is cooled by suitable means until the test material can be peeled or cut away from the aluminum metal. The test sample is cut into thirds based on height (i.e., bottom third, middle third, and top third). The ring and sphere softening points (DIN
52,011) are determined on the bottom and top sample pieces~
At variance with DIN 52,011, sample sizes of 25 g bitumen were regarded as sufficiently large for the determination of the softening.
A PmB is regarded as stabile to de-mixing if th~
difference in the ring and sphere softening points, respectively, between the bottom and top third pieces, is less than 2 K.
The Examples with comparison values according to the state of the art llelp to demonstrate the high elastic 2 ~ fi resilience and high homogeneity (i.e., good storage stability) of the inventive PmBs. The measuring methods and the tables of values are presented in Part B o~ the experimental section.
The structure of the present copolymeric additives with (meth)acrylic acid esters provides good solubility, i.e., easy miscibility into practically all types of bitumens; further, good cold flexibility; and good oxidation resistance of the present PmBs. The present PmBs are further distinguished by high ductility and broad "plasticity ranges", i.e., temperature differences between the Fraass breaking point and the softening point, measured on rings and spheres.
To produce the alkyl (meth)acrylate copolymers employed according to the present invention, long-chain alkyl esters of acrylic acid and/or particularly methacrylic acid are used as monomers wherein the alkyl groups in the ester functions have 6-28 C atoms, preferably 8-20 C atoms, particularly preferably 10-18 C atoms.
Examples of such esters are n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, isodecyl acrylate, isodecyl methacrylate, dodecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, eicosyl methacrylate, and tricosyl methacrylate, wherewith preferably the long-chain alcohols used to produce the esters are synthetic alcohols, which generally are in the form of mixtures of different alcohols, particularly in the C8-C26 range. Alcohols of this .
.
-12~
type are commercially~available, e.g.,~ under the trade names Lorol~, Alfol~, Dobanol~, and Behenyl-SR~. An exampl~ of a technical alcohol which can be used to manufacture isodecyl methacrylate is a mixture of isomeric isodecyl alcohols with mean C-number (C) = 9.9-10.3.
The prssent bitumen-modifying polyalkyl (meth)a~rylates containing maleic anhydride as a comonomer contain 80-99.9 wt.%, preferably 90-99.5 wt.%, particularly preferably 95-99 wt. %, of units of long-chain C6-C28~alkyl esters of acrylic acid, and/or preferably methacrylic acid, wherewith advantageously these esters may contain mixtures of various C6-C28 -alkyl esters. The units of the comonomer maleic anhydride are present in the amount of 0.1-20 wt.%, preferably 0.5-1o wt~%, particularly preferably 1-5 wt.%, in the copolymer or in the copolymers to be mixad.
In addition to the essential monomers contained in the present copolymeric additive, the additive may contain units of one or more other copolymerizable compounds having a double bond, in the amount of 0-19.9 wt.%, preferably 0-10 wt.%.
Examples of nonessential but useful monomers for the manufacture of the copolymers to be used according to the invention are acrylates and/or methacrylates of Cl-C5-alcohols, e.g., methyl methacrylate, isobutyl methacrylate, n-butyl acrylate, isoamyl methacrylate, and n-pentyl acrylate; also cyclopentyl methacrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl methacrylate, and multiply alkoxylated 2 ~
methacrylate esters; further, acry~ic acid, methacrylic acid, acrylonitrile, acrylamide, methaerylamlde, styrene, vinyl acetate, and particular~v nitrogen-containing, basic, polymerizable compounds, units of which are pre~erably contained in the polyalkyl (meth)acrylate addi ive in the amount of O-lO~wt.%.. . .
As basic monomers, for example, are those with tertiary amino- or amido groups, or with basic het~rocyclic groups.
Monomers with a ba.~ic nitrogen atom are, among others, dialkylaminoalkyl esters or dialkylaminoalkyl amides of (meth)acrylic acid, particularly those with a total of 7-16 C
atoms; and corresponding N-alkyl lmeth)acrylamides. Examples are dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, N-methyl (meth?acrylamide, dimethylaminoethyl (meth)acrylamide, and esters or amides of the above types but with the dimethylamino group replaced with a diethylamino, dipropylamino, dibutylamino, methylethylamino, methylbutylamino, morpholino, or piperidino group. Examples of other suitable nitrogen containing monomers are vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylimidazoline, vinylpyrazolone, vinylpiperidin~, and the (meth)acrylate esters of imidazolylalkanols or imidazolinylalkanols. For mixin~ into the bitumens the polymer components which serve to improve homogeneity and resilience, the present polyalkyl (meth)acrylates may be added to the bitumen while in solution, .' ~
-' ' , -14~
preferably in a suitable mineral oil, e.g., a highly viscous naphthene-based lubri~ating oi~, or possibly in aqueous emulsion or in pure form. According:Ly, the copolymers of the present invention may be manufactured according to the known, customarv methods via primarily radical polym~rization of the monomsrs in solution or in emulsion, or possibly in the mass (see Rauch-Puntigam, H., and Voelker, Th., 1967, "Acryl- und Methacrylverbindungen", pub. Springer-Verlag, Berlin, 1967, particularly pp. 203, 207, 230-233, 238, 327).
~ he molecular weight Mw of the inventively employed polyalkyl (meth)acrylates should be > 10,000, preferably >
30,000. Mw values up to c. 1,500,000 can be achievad. The Mw is controlled, as a rule, by the amount of the polymerization initiator in relation to the polymerizable monomers, or in relation to the use of a regulator, e.g., an alkyl mercaptan.
Known methods may be used, such as that of Rauch-Puntigam, ~., loc. cit. The molecular weight, Mw, in g/mol oP the polymer obtained, may be determined by the method of light scattering ("Ullmanns Encyklopaedie der technischen Chemie", 4th Ed., V. 15, pp. 385-287), or may be estimated from the viscosity relation ~p/c = 0.0156 x Mw0~5 , with the viscosity being measured according to DIN 7745 at 20C with chloro~orm as the solvent.
-15- 2 ~
For modi~ying the bitumens accc~rding to the present invention, the alkyl (meth)acrylates copolymerized with maleic anhydride, with the said copolymers having molecular weights preferably ~ lo,oO0, are added in ~he amount of 0.5-50 wt.%, preferably 0.5-20 wt.%, particularly preferably 1-15 wt.~, and more preferably 2-10 wt.%. The amount o~ modifying copolymer added depends on the intended use of the resulting PmB.
In addition to the alkyl (meth)acrylates copolvmerized with maleic anhydride, which copolymers are essential according to the present invention, the present PmBs may contain other known polymeric compounds, as improvers for bitumeniferous binders and mixtures. Examples are polyoleins (e.g., polyethylene and polypropylene), ethylene-vinyl acetate copolymers, or ABS copolymers, wherewith the ratio of alkyl (meth)acrylate copolymer to these other polymers may be 1:0 to 1:4, by weight. According to the invention, in this category the use of olefin copolymers modified with maleic anhydride is advantageous.
The alkyl (meth~acrylates copolymerized with maleic anhydride, after said copolymers are mixed into bitumen compositions, yield PmBs according to the present invention which are homogeneous according to tests (tube test) conducted after storage at 180C. The PmBs have elastic resilience up to c. 56-90%, as compared to values o~ c. 30-55% obtained according to the state of the art.
-16- 2~ 3~
The term "bitumen" in-th~ context of the present invention should be understood to mean any and all bitumens usable, e~g., in roadbuilding or roofing, or as a casting compound, sealing compound, or coating composition.
In the Examples hereinbelow, there are descriptions of the manufacture of the alkyl (meth)acrylates copolymerized with maleic anhydride, the manufacture of the inventive bitumen-polymer mixtures (PmBs), and the properties of the PmBs. Corresponding compari.son examples according to the state of the art are presented.
The present invention will be further illustratad by these Examples, whioh are not intended to be limitative but are provided solely ~or purposes of illustration.
Examples:
A) Synthesis of the Polymers:
1. Synthesis of the maleic anhydride - alkyl methacrylate copolymers. Examples 1-7:
In a 4 L 4-neck round-bottomed flask with a sword shaped stirrer, a re~lux condenser, and an internal thermometer/ 1000 g isodecyl methacrylate and maleic anhydride in the specified weight ratios, and 500 or 180 g (Example 3 or 5) naphthene-based oil, were heated to 75C under stirring. By passage of N2 the solution was freed ofloxygen within 1 hr. Then the polymerization was initiated with 0.2 g tert~butyl pivalate and 0.2 g tert-butyl perbenzoate. After 1 hr the temperature , -17~ 3 ~
was increased to 130C, and in Examples 3 and 5 an additional 320 y oil was added as a diluent. '; hr after the start of the reaction, 1 g tert-butyl perbenzoate was added for after-pol~merization, and an additional 500 g oil was added as a diluent.
The total duration of the polymeri~ation was 16 hr. The product was a clear, reddish brown, viscous solution with 50 wt.% polymer content. As a rule, conversion was > 97%.
Comparative_E _ e ~ 1:
The manufacturing method was analogous to that of Example 1, but without maleic anhydride.
=
comparative Examples 2 and 3:
In a 1 L ~ neck round-bottomed flask with a sword-shaped stirrer, a reflux condenser, and an internal thermometer, 500 g toluene, 52~8 g methyl acrylate or n-butyl acrylate, and 2.8 g maleic anhydride were heated to 70C, under stirring. A~ter this temperature was reached, the reaction was initiated with 0.11 g tert-butyl perpivalate. Then ~22.2 g methyl acrylate or n-butyl acrylate, 22.2 g maleic anhydride, and 1.33 g tert-butyl perpivalate were added portionwise over a period of 3 hr. 3 hx after completion of the additions, 1.0 g tert-butyl perpivalate was added for after polymerization.
The total duration of the polymerization was lO hr. The -18 2~'7~
product was a clear, colorless, viscous solution with 50 wt.%
polymer content.
The polymer was isolated by evaporation concentration on a rotational evaporator, and was dr:ied 12 hr at 70C in a vacuum drying cabinet.
B) Manufacturin~ and estlnn of polymer-modified bitumens (PmBs):
General method of manufacturinq PmBs:
A commercially available standard bitumen was heated to 150C in a flask with a sword-shaped stirrer. At this temperature, the given additive as specified in Tables Z-4 was added in the amount indicated, in the form of a 50% polymer ~solution in oil. The mixture was stirred 1 hr. After this period, in every case the polymer had been completely mixed in, and the resulting PmB was homogeneous and smooth.
The following tests were performed on the PmBs:
i) Ductility according to DIN 52 013.
ii) Softening point, "RuX", according to DIN 52 011.
iii) Elastic resilience according to ~mB Tl 89*, Sec.
3.2.1.
iv) Homogeneity following hot storage at 180C (tube test), according to PmB Tl 89, Sec. 3.2.1.
(* PmB Tl 89 rapresents "Technische Lieferbedingung fuer polymermodifiziertes Bitumen 1989".) In Table 1, infra, the polymers which were synthesized (the inventive and the compari~on polymers) are described.
.~ , ' , ~ . ' ' -19- ~7~
Tables 2-4 pr~sent test results on the present PmBs, and PmBs 12-08-92 Table 5 presents t~st results on the ~M~ which PmBs were prepared according to the state of t:he art.
Table 1 .. _. _ _ ...
Amounts of th~ ~p/c Pol_m~r monomers u~d _ Solvent ~ml/g) Example 1 990 g i80_ ecyl methacrylate 1000 g oil 81 10 g mal~ic anhydride ~ , .
Example 2 980 g i~odecyl methacrylate ~ 78 20 g maleic anhydride ~
Example 3 _ 980 ~isodecyl ethacrylat~ 1000 g oil _ 114 ~*
_ ,_ .. - ....... _._ 20 g maleic anhydride ~ ____ Example 4 950 g isodecyl m~thacrylat~1000 g oil 70 ~ . _ . . _ _ .. ..
_ _ 50 g maleic anhydride _ ~
Example 5 950 g isodecyl methacrylato1000 g oil llO ~*
~. ..... __ . _ __ _ .
_ . 50 g maleic anhydride . . _ Example 6 925 g isodecyl methacrylate 1000 g o_l 49 75 g malelc anhydrid~ _ 2xample 7 _ 900 g i~odecy e _acrylate 1000 g oil 57 100 g maleic anhydride _ _ Comparison Example l 1000 g isod~cyl methacrylate 1000 g oil 91-. . _ -- - v.. ... _ .. ___ Comparison Example 2 475 ~ methyl acrylat~ 500 ~ toluene 41 . . . ~ 25 g maleic anhydride . ____ Compari~on Example 3 47S g butyl acrylat~500 g toluen2 46_ 25 g maleic anhydride _ - .. _____ _ ~ _ __ . -~ sp/c estimated in Chloroform (DIN 7745) ** Startconcentration of the monomers : 90 %
12.08.92 ' -20- 2 0 ~7 r~ fi Table 2 = . = _ _ =
Amount of Ductility Softening Elastic Homo-Bitumen Additive at 13C point "RuK" resilience geneity (cm) _ (C) (%)- -- (,~) 1000 9 _ ~ > 150 _ 48.9 19 920 g 80 g Exam~le 1 > 150 _ 65 1.2 --- ----TT _ _ _ 940 g 60 g Example 1 _ 72 960 g 40 g Example 1 _ _ 75 _ _ _ _ _ _ ~
920 g 80 g Example 2 > 100 43.8 68 1.6 940 g 60 g Example 3 150 44.2 59 0.4 920 g 80 g Example 4 > 150 _ 56 0.5 - . . ._ _ _ __ 940 g 60 g Example 5 150 _ 45.1 _ 59 1.3 920 g 80 g Comparison > 100 _ 31 2.2 Example 1 _ - -- . T _._ ___ ____. __ _ _ __ _ _ _ _ 940 g 60 g Compari~on > 100 _ 26 1.0 Example 1 _ - _ . . ~ . . _ .
Table 3: Bitumen 13 200 from a different German refinery = _ Amount of Ductility Softening Elastic Homo-Bitumen Additive at 13C point "RuX~ re~ilisnce geneity ~ _ .... _ ~cm) ~C) (-~) (C) 1000 g _ > 100 38.~ 25 . _ . .
940 g 60 g Example 3 > 150 _ 53 0.0 _ ._ _ . _ _ _ _ 940 g 60 g Exam~le 5 ~ 100 _ 58 0.4 _ _ _ _ ~ _ . _ T
.960 g 60 g Comparison > 150 _ 36 0.4 Example 1 __ _ _ -- ~ ~
-21- 2 ~
Table 4: Bitumen 8 80 from a different German refinery , .__ = - . _ _ _ . 1 Amount of ~uctility Softe~ing Elastic Homo-8itum0n Additive at 13C point "RuK" resilience geneity ¦- _ _ _ (cm) _ ( C) (~) - (c) 1000 g _ 47 47.9 13 _~ _ _ 940 g 60 g Example 5 > 150 49.7 52 _ - _ 970 g 30 g Example 5 77 53.1 53 0.4 (100% polymer) _ . _ ~. , _ 940 g 60 g Comparison > 150 _ 17 1.0 Example 1 . ... _ ... .. _ Table 5: Bitumen B 80 from a di~ferent German refinery . . -- -- -- . --Amount of Du~tility Softening Elastic Homo-Bitumen Additive at 13C point "RuR" r~ nce geneity _ . ~cm) (C) (~) ( C) _ 940 g 60 g Compari~on 90 44.5 24 1.2 Example 2 _ . _ _ 940 g 60 g Compari~on > 120 44.0 25 2.3 Example 3 _ _ From the characterization of the bitumen mixtures of composition according to Comparison Examples 2 and 3 (Table 5), it is clear that these compositions are inferior to the examples of the present invention in elastic resilience and in ductility. Even though maleic anhydride is used as a comonomer in amounts comparable to those used in the present examples, the properties shown in Table 5 are not superior to those of the bitumen mixtures prepared with the PAMA
homopolymer according to Comparison Example 1.
~ ~rl 7 ~ r~
~7~ ~h Having described the present invention, it will be readily appar~nt to one of ordinary skill in the art that many changes and modifications may be made to the above-described embodiments without departing from the spirit and scope of the present invention.
Claims (9)
1. A polymer-modified bitumen, having homogeneity, high elastic resilience, good cold flexibility, and high thermal stability, which comprises polymer components in the amount of 0.5-50 wt.%., at least 20 wt.% of which components comprise modifying polyalkyl (meth)acrylates; and wherein the modifying polyalkyl (meth)acrylates comprise units of C6-C28-alkyl (meth)acrylates in the amount of 80-99.9 wt,%, maleic anhydride in the amount of 0.1-20 wt.%, and one or more other compounds with not more than one polymerizable double bond in the amount of 0-19.9 wt.%, and said modifying polyalkyl (meth)acrylates being uniformly distributed in the bitumen.
2. The homogeneous polymer-modified bitumen according to Claim 1, wherein the modifying polyalkyl (meth)acrylates contain monomer units of maleic anhydride in the amount of 0.5-10 wt.%.
3. The homogeneous polymer-modified bitumen according to Claim 1, wherein the PmB further contains maleic anhydride -olefin copolymers as bitumen-modifying polymers, in addition to copolymers of maleic anhydride and alkyl (meth)acrylate.
4. The homogeneous polymer-modified bitumen according to Claim 2, wherein the modifying polyalkyl (meth)acrylates contain monomer units of maleic anhydride in the amount of 1-5 wt. % .
5. The homogeneous polymer-modified bitumen according to Claim 1, wherein said modifying polyalkyl (meth)acrylates comprise units of C8-C20-alkyl methacrylates.
6. The homogeneous polymer-modified bitumen according to Claim 1, wherein said modifying polyalkyl (meth)acrylates comprise units of C10-C18-alkyl methacrylates.
7. The homogeneous polymer-modified bitumen according to Claim 1, wherein the modifying polyalkyl (meth)acrylates are used in the amount of 90-99.5 wt.%.
8. A method of manufacturing a polymer-modified bitumen which exhibits homogeneity, high elastic resilient, good cold flexibility, and high thermal stability; which comprises forming a mixture of bitumen and polymer, which mixture contains poly(meth)acrylate in the amount of 0.5-50 wt.%, by mixing a polymer, comprising units of C6-C28-alkyl (meth)acrylates in the amount of 80-99.9 wt.%, maleic anhydride in the amount of 0.1-20 wt%, and one or more other compounds with not more than one polymerizable double bond, in the amount of 0-49.8 wt.%.
9. The method according to Claim 8, which further comprises adding maleic anhydride - olefin copolymers as polymeric bitumen-modifying agents in addition to and along with the maleic anhydride - alkyl (meth)acrylate polymers.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4128640A DE4128640A1 (en) | 1991-08-29 | 1991-08-29 | ALKYL (METH) ACRYLATE MALE ACID ANHYDRIDE COPOLYMER-MODIFIED BITUMEN |
| DEP4128640.5 | 1991-08-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2077136A1 true CA2077136A1 (en) | 1993-03-01 |
Family
ID=6439366
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002077136A Abandoned CA2077136A1 (en) | 1991-08-29 | 1992-08-28 | Alkyl (meth)acrylate-maleic anhydride copolymer-modified bitumen |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5266615A (en) |
| EP (1) | EP0538581A1 (en) |
| CA (1) | CA2077136A1 (en) |
| DE (1) | DE4128640A1 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2726830B1 (en) * | 1994-11-10 | 1996-12-20 | Elf Aquitaine | PROCESS FOR THE PREPARATION OF BITUMEN / POLYMER COMPOSITIONS FOR THE PRODUCTION OF COATINGS AND MOTHER POLYMER SOLUTION FOR THIS PREPARATION |
| US5576363A (en) * | 1994-12-23 | 1996-11-19 | Owens Corning Fiberglas Technology, Inc. | Thermosetting asphalt |
| US5580376A (en) * | 1995-04-26 | 1996-12-03 | Ashland Inc. | Asphalt improvement |
| FR2748487B1 (en) * | 1996-05-10 | 1998-07-10 | Elf Antar France | BITUMEN / POLYMER COMPOSITIONS WITH IMPROVED STABILITY AND THEIR APPLICATION TO THE PRODUCTION OF COATINGS |
| US5773496A (en) * | 1996-05-31 | 1998-06-30 | Koch Industries, Inc. | Polymer enhanced asphalt |
| JPH10120839A (en) * | 1996-10-15 | 1998-05-12 | Sumitomo Chem Co Ltd | Asphalt improver and asphalt composition containing the same |
| US5795929A (en) * | 1997-04-22 | 1998-08-18 | Koch Enterprises, Inc. | Polymer enhanced asphalt emulsion |
| JPH1129665A (en) * | 1997-07-09 | 1999-02-02 | Sumitomo Chem Co Ltd | Asphalt modifying agent and asphalt composition containing the same agent |
| EP1350813A1 (en) * | 2002-04-01 | 2003-10-08 | Rohm And Haas Company | Polymer-modified asphalt |
| US7144933B2 (en) * | 2003-11-12 | 2006-12-05 | Eastman Chemical Company | Modified asphalt compositions |
| US7202290B2 (en) * | 2003-11-12 | 2007-04-10 | Eastman Chemical Company | Modified asphalt compositions |
| FR2949232B1 (en) * | 2009-08-18 | 2011-10-28 | Ceca Sa | BITUMINOUS COMPOSITION CONTAINING SUPRAMOLECULAR POLYMER |
| DE102017011894A1 (en) | 2017-12-21 | 2019-06-27 | Martin Müller-Roosen | Process for the production of pellets, devices for carrying out the process and the pellets producible by the process |
| CN113773660B (en) * | 2021-09-22 | 2022-11-25 | 山东格瑞特监理咨询有限公司 | Environment-friendly asphalt modifier |
| CN114381132B (en) * | 2022-01-14 | 2022-12-06 | 苏州科技大学 | Copolymer modified asphalt |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2420082A (en) * | 1943-07-22 | 1947-05-06 | Standard Oil Dev Co | Bituminous composition comprising an asphalt and a polymerized ester of methacrylic acid |
| US2828429A (en) * | 1953-07-29 | 1958-03-25 | Fata S R L | Device for operating rolling blinds |
| DE1188807B (en) * | 1961-03-22 | 1965-03-11 | Lechler Bautenschutzchemie K G | Process for the production of sealing compounds from bituminous and synthetic rubber-elastic materials |
| DE1240773B (en) * | 1962-01-02 | 1967-05-18 | British Petroleum Co | Binder for road surfaces |
| DE2331727A1 (en) * | 1973-06-22 | 1975-01-16 | Solf Karl Peter | Bitumen, tar or pitch contg. poly(meth)acrylate - as road-surfacing compsn. or adhesive of high bonding strength and softening pt. |
| DE2435753A1 (en) * | 1974-07-25 | 1976-02-12 | Basf Ag | MOLDING MATERIALS BASED ON BITUMES AND OLEFINCOPOLYMERIZATES |
| DE2509473A1 (en) * | 1975-03-05 | 1976-09-16 | Roehm Gmbh | Bitumen additives of acrylic copolymers with basic nitrogen cpds. - giving improved adhesion to mineral fillers |
| JPS52141829A (en) * | 1976-05-21 | 1977-11-26 | Mitsubishi Rayon Co | Bitumen composition |
| FR2528059A1 (en) * | 1982-06-03 | 1983-12-09 | Charbonnages Ste Chimique | COMPOSITIONS FOR SEALANTS AND PRODUCTS SO PRODUCED |
| FR2536081B1 (en) * | 1982-11-17 | 1986-06-06 | Charbonnages Ste Chimique | BITUMEN-POLYMER COMPOSITIONS APPLICABLE TO THE PRODUCTION OF ROAD BINDERS |
| JPS6279268A (en) * | 1985-10-03 | 1987-04-11 | Idemitsu Petrochem Co Ltd | Bituminous composition |
| EP0252142A4 (en) * | 1986-01-10 | 1988-06-08 | Dow Chemical Co | Bituminous compositions. |
| US4833184A (en) * | 1987-03-10 | 1989-05-23 | The Lubrizol Corporation | Acrylate polymer modified asphalt compositions |
| DE3925827A1 (en) * | 1989-08-04 | 1991-02-07 | Roehm Gmbh | Bitumen compsn. |
| EP0400437B1 (en) * | 1989-06-01 | 1993-07-21 | Röhm Gmbh | Bitumen with improved elasticity |
| DE3917816A1 (en) * | 1989-06-01 | 1990-12-06 | Roehm Gmbh | Bitumen compsn. |
| DE3917815A1 (en) * | 1989-06-01 | 1990-12-06 | Roehm Gmbh | POLYMER MODIFIED BITUMEN |
| DE4006499A1 (en) * | 1990-03-02 | 1991-09-05 | Roehm Gmbh | METAL COMPOUNDS-CONTAINING POLYMER-MODIFIED BITUMES |
| DE4040234A1 (en) * | 1990-12-15 | 1992-06-17 | Roehm Gmbh | HOMOGENEOUS, POLYALKYL (METH) ACRYLATE-MODIFIED BITUMINA |
-
1991
- 1991-08-29 DE DE4128640A patent/DE4128640A1/en not_active Withdrawn
-
1992
- 1992-08-17 US US07/930,894 patent/US5266615A/en not_active Expired - Fee Related
- 1992-08-19 EP EP92114119A patent/EP0538581A1/en not_active Ceased
- 1992-08-28 CA CA002077136A patent/CA2077136A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| DE4128640A1 (en) | 1993-03-04 |
| EP0538581A1 (en) | 1993-04-28 |
| US5266615A (en) | 1993-11-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |