MXPA99002189A - Plastifiers and means processing for elastome - Google Patents

Abstract

The present invention relates to an elastomer composition, including: at least one elastomer, a plasticizer which includes at least one polymeric material having a weight average molecular weight (Mw) of 500 to 1,000,000, formed of at least one ethylenically unsaturated monomer and a curing agent, wherein at least the polymeric material is substantially permanent within the elastomer. The elastomer compositions in question have improved plasticity and ease of processing are auxiliary migration, heat extraction or solvent and compatibility problems.

Description

PLASTIFICATORS AND MEANS PROCESSING FOR ELASTOMEROS The present invention relates to elastomer compositions, a process for preparing the same and methods of plasticizing and / or improving the processability of elastomers. These compositions have improved plasticity and processability with reduced loss of the plasticizer due to extraction or migration. Elastomers are useful in many fields in a variety of applications. For example, elastomers are used in the automotive industry, in defense, in space, in drilling wells and in oil extraction. With the elastomers can be manufactured tires, seals, joints, extruded items, special parts, chaperia, etc., for use in the aforementioned industries. Accordingly, in these applications, parts made with elastomers may have to be resistant to, for example, fuel, lubricants, extreme temperatures, water, steam, or chemicals. In addition, depending on the application, it may be required that these elastomers be plasticized to provide low temperature flexibility, as well as improved elongation and traction properties. Also, it is preferable that these elastomers have a certain amount of processing facility for an efficient and economical manufacture of the required part. - To provide or improve the plasticity of the materials, plasticizers are added to the elastomers.

Specifically, plasticizers are materials which when added to a polymeric material cause an increase in workability and flexibility caused by a decrease in the glass transition temperature (Tg) of the polymer. Generally, plasticizers are of two types, internal and external. The internal plasticizers are made by creating a plasticizer polymer in place at the same time the polymer is formed. The external plasticizers are prepared completely before being added to the polymer. (Generally, use the Kirk-Othmer Chemical Technology Encyclopedia [Kirk-Othmer Encyclopedia of Chemical Technology], Volume 19, pages 258-273 for a discussion of plasticizers.) Sometimes, conventional plasticizers tend to migrate into the elastomer, "opening" to the surface and "flowing" of the elastomer so that the effective lifetime of a part made of the elastomer is shortened. This migration is exacerbated by the environments in which some of the elastomeric materials are required to work. These environments can cause "the plasticizer to be extracted from the elastomer. Subsequently, the plasticization decreases and the environment can be contaminated with the plasticizer. A conventional process for overcoming the migration problems of plasticizers is by the use of plasticizers having a high molecular weight. However, the use of these high molecular weight plasticizers results in problems in the mixing of the elastomers. That is, it was very difficult to mix and match the components in a compatible elastomeric composition. Also, the processability of these elastomers is sacrificed. Conventionally, many chemical compositions have been used for the purpose of plasticizing polymers to improve flexibility, low temperature performance, percentage elongation before breaking, Shore A hardness and resistance to tearing and cracking when struck. These physical tests are used as a real indicator of actual performance in a finished product and are well known in the art. For example, these physical tests are described in Rubber Technology, second edition, Chapters 4 and 5. Short chain (meth) acrylates have been suggested as plasticizers in rubbers. For example, hydroxyethyl and hydroxypropyl methacrylates, as well as their alkoxy derivatives, have been suggested, as plasticizers in polychloroprene compositions. (See UK Research Disclosures, Volume 211, page 403 # 21122.) Also, C 8 -C 3 alkyl methacrylates / as well as 2-ethoxy-ethyl methacrylates combined with powdered elastomers, ie natural rubber, have been suggested. styrene-butadiene, or acrylonitrile butadiene, as mild acrylic elastomeric compositions for use in dental prostheses. It is said that this combination avoids the use of plasticizers. (See Parker, S. and Braden, Biomaterials [Biomaterials] 1990, Volume 11, September.) Vulcanized rubber was plasticized with C7-C? 2 alkyl methacrylates. See Panchenko and others Kauch, I Rezina (4), 24-26 (1979)). This reference suggests that lower chain methacrylates, that is, heptyl methacrylate, have the highest plasticizing capacity. In the patent 5, 026, 807 of the United States, an ester of methacrylic acid, having a group of repeating esters within a long chain alkyl substituent, that is, between a group of C3-20 alkyls and a group of hydrocarbons C? _2o, is used as an elastomer additive. The ester was mixed with a polymer having elasticity to provide a composition having improved resistance to oil, heat and low temperature. In U.S. Patent 5,612,418, combinations of C4-C6 alkyl acrylate polyacrylate copolymers and terpolymers, C1-C3 alkyl acrylates and C2-C12 alkoxyalkyl acrylates and partially hydrogenated nitrile rubbers are described as useful in automotive motor belts, gaskets, seals, etc. However, the described compositions also contain a plasticizer additive, which indicates that the polyacrylates were not considered to have plasticizing properties. The possible use of acrylate and methacrylate polymers as plasticizers is suggested in US Patent Nos. 4, 158, 736 and 4, 103, 093. However, these patents do not disclose specific elastomer compositions or use in elastomer compositions. None of these references addresses the problem of migration of plasticizers and compatibility of plasticizers / elastomers discussed above. So far, suitable non-migrating plasticizers which are readily mixed with a variety of elastomers, including elastomers, such as fluoroelastomers which are known to be difficult to mix, have not been disclosed in the prior art. Accordingly, there is a need for a plasticizer for elastomers which has a substantial amount of permanence within the elastomer composition, but which is also compatible with the elastomer and effectively transmits the "plastic" properties to the elastomer. An example of this need can be seen in the acrylic rubber mix (ACM) on line 1, paragraph 3 on page 930 of Kirk-Othmer; Volume 8, where lower concentrations of plasticizers should be used due to the loss of plasticizers due to volatility at the higher typical ACM service temperatures and / or their ease of partial extraction by aggressive fluids where ACMs are used. Therefore, other additives are required to improve processability due to decreased levels of plasticizers. The present inventors have discovered new compositions of elastomers which are plasticized by polymeric materials prepared from at least one ethylenically unsaturated monomer and new processes for preparing them. The elastomer compositions in question have improved plasticity without migration or compatibility problems associated with prior art elastomer compositions. This is true even in elastomeric materials, such as fluoroelastomers, which until now have not had plasticizers available for use in them, or at best they have had very few. The polymeric compositions of the elastomer compositions of the present invention are present as interpenetrating networks of polymeric plasticizers and / or processing media within the polymer matrix of elastomers. The chains of polymeric (meth) acrylates are trapped within the elastomer thereby having an improved performance within the elastomer. This results in a longer life to the plasticized elastomer and the ability to add more filler product without flowing out of the filler material. This is achieved without loss of compatibility between the plasticizer and the elastomer. In a first aspect of the present invention, an elastomer composition is provided, including: (A) at least one elastomer; (B) a plasticizer comprising at least one polymeric material, having a weight average molecular weight (Mw) of 500 to 1,000,000, formed from at least one ethylenically unsaturated monomer and (C) a hardening agent, wherein at least A polymeric material is substantially permanent within the elastomer. In a second aspect of the present invention, there is provided a process for preparing an elastomer composition, including (A) providing a blend of an elastomer, at least one ethylenically unsaturated monomer or a polymeric material, having a weight average molecular weight (Mw) of 500 to 1,000,000, formed from at least one ethylenically unsaturated monomer and a hardening agent and (B) hardening the elastomer composition, wherein during hardening at least one ethylenically unsaturated monomer, if present, is polymerized in place to form an elastomer composition, wherein at least one polymeric material is substantially permanent within the elastomer.

In a third aspect of the present invention, there is provided a method for plasticizing an elastomer, comprising: (A) providing an elastomer composition according to the present invention, wherein at least one polymeric material is present in an effective amount for plasticize the elastomer. In a fourth aspect of the present invention, there is provided a method for improving the processability of an elastomer, comprising: (A) providing an elastomer composition according to the present invention, wherein at least one polymeric material is present in an effective amount to improve the processability of the elastomer. As used herein, the term "(C? -C50)", "(C -C2o)" / "(C20-C50)", etc., means a straight chain or branched chain alkyl group having 1 to 50, 1 to 20, 20-50, etc., carbon atoms per group. As used herein, the term "(meth) acrylates" includes both (meth) acrylate (s) and acrylate (s) within its scope. As used herein, the term "elastomer" refers to a polymer which passes through reversible extensibility and includes both elastomers, and thermoplastic elastomers. Also, it is understood that the term "polymeric" includes within its scope all types of molecules characterized as molecules having repeating units of atoms or molecules linked together such as oligomers, homopolymers, copolymers including block, random and alternating copolymers, polymers and grafted copolymers, terpolymers, etc. It is understood that the term "PHR" means parts per elastomer of 100 parts. In all this specification and claims, unless otherwise indicated, references to percentages are by weight, all temperatures are in degrees centigrade and all pressures are atmospheric. It should also be understood that, for the purposes of this specification and claims, the boundaries of ranges and relationships expressed herein may be combined. By. For example, if the ranges of 1-20 and 5-15 are expressed for a particular parameter, it is understood that the ranges of 1-15 or 5-20 are also contemplated. As indicated above, the elastomer compositions of the present invention include at least one elastomer. The elastomer is generally present in the elastomer composition from 20 to 99.9, preferably 40 to 99.9, more preferably 60 to 99.9 weight percent of the elastomer composition. Generally, any suitable elastomer may be used in the elastomer compositions of the present invention.

Preferably, the elastomer is a degraded, thermosetting elastomer. Suitable elastomers include, but are not limited to, natural rubbers; modified natural rubbers including those grafted with acrylates or those which are halogenated; styrene-butadiene elastomers such as styrene-butadiene rubber (SBR), SBR solution (SSBR), carboxylated SBR (XSBR), styrene-butadiene copolymer high (HS / B), pyridine (vinyl) -styrene-butadiene rubber ( PSBR); chloroprene elastomers such as polychloroprene (CR) elastomers and carboxylated polychloroprene rubber (XCR); polybutadiene elastomers including 1-2 isomers, hydroxyl, carboxyl, emulsion polybutadiene rubber (EBR) and halogen-terminated polybutadiene elastomers; butyl elastomers such as polyisoprene elastomers (IR), isoprene / isobutylene elastomers (IIR), halogenated butyl rubber (HIIR) as bromobule elastomer, chlorobutyl elastomer and polyisobutylene elastomers; nitrile elastomers such as acrylonitrile-butadiene elastomers (NBR), hydrogenated or partially hydrogenated acrylonitrile-butadiene elastomer (HNBR), nitrile-isoprene elastomers (NIR); polyethylene elastomers such as chlorinated polyethylene elastomer and chlorosulfonated ethylene elastomer; ethylene-propylene elastomers such as copolymers (EPM) and terpolymers (EPDM) of ethylene and propylene; acrylic based elastomers such as acrylate elastomers (AM), acrylate butadiene elastomer (ABR) and ethylene acrylic elastomers; silicone elastomers as organopolysiloxane elastomers; fluoroelastomers; epichlorohydrin elastomer; polyalkanemer elastomers as elastomers prepared, for example, from cyclooctene, cyclopentene, or 1,5-cyclooctadiene monomers; organic polysulfide elastomers; urethane elastomers; and mixtures or combinations thereof. In one embodiment, at least the elastomer is a styrene-butadiene elastomer, chloroprene elastomer, butyl elastomer, polybutadiene elastomer, nitrile elastomer, polyethylene elastomer, ethylene-propylene elastomer, acrylic elastomer, silicone elastomer, fluoroelastomer, epichlorohydrin elastomer, polyalkanemer elastomer, polysulfide elastomer, polysulfide elastomer, urethane elastomer, mixtures or combinations thereof. In a preferred embodiment, at least the elastomer is an acrylonitrile-butadiene elastomer, hydrogenated acrylonitrile-butadiene elastomer, partially hydrogenated acrylonitrile-butadiene elastomer, polyethylene elastomers modified as chlorinated or chlorosulfonated polyethylene elastomer, ethylene acrylic elastomer, styrene-butadiene elastomer, fluoroelastomer, or mixtures or combinations thereof. In a more preferred embodiment, at least the elastomer is acrylonitrile-butadiene elastomer, hydrogenated acrylonitrile-butadiene elastomer, partially hydrogenated acrylonitrile-butadiene elastomer, fluoroelastomer, or mixtures or combinations thereof. In the most preferred embodiment, at least the elastomer is a fluoroelastomer. The elastomer may also be a thermoplastic elastomer (TPE) having an elastomeric component and a thermoplastic component. Suitable examples include, but are not limited to, polyolefin thermoplastic elastomers, polyester / polyether thermoplastic elastomers, thermoplastic elastomers based on isoprene homopolymers and copolymers, and urethane thermoplastic elastomers. The elastomer compositions of the present invention also include at least one polymeric material formed from at least one ethylenically unsaturated monomer. The polymeric material is generally present in the elastomer composition from 1 to 100, preferably 1 to 50, more preferably 2 to 30 PHR. Generally, at least one polymeric material present in the elastomer has a weight average molecular weight (Mw) of 500 to 1,000,000, preferably 500 to 500,000, more preferably 500 to 100,000 and more preferably 500 to 50,000.

The ethylenically unsaturated monomers which are useful as monomers in the present invention include acrylic and methacrylic acid and esters thereof. Generally, the (meth) acrylates are O. to C50 (meth) acrylates. Examples of alkyl methacrylate or algayl acrylate where the alkyl group contains 1 to 6 carbon atoms (also called "low-cut" alkyl methacrylate or alkyl acrylate), are methyl methacrylate (MMA), methacrylate ethyl (EMA), methyl and ethyl acrylate, propyl methacrylate, butyl methacrylate (BMA) and butyl acrylate (BA), isobutyl methacrylate (IBMA), hexyl methacrylate and cyclohexyl, cyclohexyl acrylate and combinations thereof . Examples of the alkyl methacrylate or alkyl acrylate where the alkyl group contains from 7 to 15 carbon atoms (also called the "half-cut" alkyl methacrylates or alkyl acrylates), are 2-ethylhexyl acrylate (EHA), 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, isodecyl methacrylate (IDMA, based on a mixture of branched (Cio) alkyl isomers), undecyl methacrylate, dodecyl methacrylate (also known as lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (also known as myristyl methacrylate), pentadecyl methacrylate and combinations thereof. Also useful are: dodecyl pentadecyl methacrylate (DPMA), a mixture of linear and branched isomers of methacrylates of dodecyl, tridecyl, tetradecyl and pentadecyl; and lauryl-myristyl methacrylate (LMA), a mixture of dodecyl and tetradecyl methacrylates. The examples of the alkyl methacrylate or alkyl acrylate where the alkyl group contains from 16 to 24 carbon atoms (also called the "high-cut" alkyl methacrylates or alkyl acrylates), are hexadecyl methacrylate, heptadecyl methacrylate , octadecyl methacrylate, nonadecyl methacrylate, cosyl methacrylate, eicosyl methacrylate and combinations thereof. Also useful are: cetyl-eicosyl methacrylate (CEMA), a mixture of hexadecyl methacrylate, octadecyl, cosyl and eicosyl; and cetyl-stearyl methacrylate (SMA), a mixture of hexadecyl methacrylate and octadecyl. Mixtures of one or more (meth) acrylates of low cut, half cut or high cut can also be used. In one embodiment, at least the only monomer is a C10 to C2o alkyl (meth) acrylic monomer and at least the only polymeric material is a homopolymer or copolymer of at least C10 alkyl (meth) acrylate monomers. C2o • In a preferred embodiment, at least the only monomer is lauryl methacrylate, stearyl methacrylate, isomers thereof or a mixture thereof and at least the only polymeric material is a homopolymer of lauryl methacrylate monomer or stearyl methacrylate monomer or a copolymer of lauryl methacrylate and stearyl monomers. In one embodiment, at least the monomer is a mixture of the Co (C2o) alkyl (meth) acrylate monomers described above. For example, these mixtures include, but are not limited to, mixtures of C? 2-C? 4 monomers, or mixtures of C18-C2o monomers. In another embodiment, the monomer is a (meth) acrylate and the polymeric material is a terminally unsaturated (meth) acrylate oligomer. In one embodiment, the terminally unsaturated (meth) acrylate oligomer has at least 30 percent, preferably at least 50 percent and more preferably at least 60 percent terminal unsaturation in the oligomeric chain. In another embodiment, the terminally unsaturated butyl acrylate oligomer is 30 percent to 100 percent, preferably 50 percent to 90 percent, more preferably 60 percent to 80 percent terminal unsaturation in the oligomeric chain. In a preferred embodiment, the monomer is butyl acrylate and the polymeric material is a terminally unsaturated butyl acrylate oligomer. The alkyl and alkyl acrylate methacrylate monomers of cutting and high cutting medium described above are generally prepared by standard esterification methods using technical grades of long chain aliphatic alcohols and these commercially available alcohols are mixtures of alcohols of different chain lengths containing between 10 to 15 or 16 to 20 carbon atoms in the alkyl group. Examples of these alcohols are the various Ziegler catalyzed Alfol alcohols from Vista Chemical Company, ie, Alfol 1618 and Alfol 1620, various Ziegler-catalyzed Neodol alcohols from Shell Chemical Company, ie, Neodol 25L, and naturally derived alcohols such as TA-1618 and Procter &CO-1270; Gamble. Accordingly, for the purposes of this invention, the term alkyl (meth) acrylate includes not only the named individual alkyl (meth) acrylate product, but also includes mixtures of the alkyl (meth) acrylates with a predominant amount of the Particularly named alkyl (meth) acrylate. Another class of suitable ethylenically unsaturated monomers are vinylaromatic monomers which include, among others, styrene, α-methylstyrene, vinyltoluene, p-methylstyrene, ethylvinylbenzene, vinylnaphthalene, vinylxylenes and the like. The vinylaromatic monomers may also include their corresponding substituted counterparts, such as halogenated derivatives, ie, containing one or more halogen groups, such as fluorine, chlorine or bromine; and nitro, cyano, alkoxy, haloalkyl, carbalkoxy, carboxy, amino, alkylamino derivatives and the like. Another class of suitable ethylenically unsaturated monomers are nitrogen containing cyclic compounds and their thio analogs, such as vinylpyridines such as 2-vinylpyridine or 4-vinylpyridine and substituted C-vinylpyridines of lower alkyl (C? -8) such as: 2-methyl-5-vinyl -pyridine, 2-ethyl-5-vinylpyridine, 3-methyl-5-vinylpyridine, 2,3-dimethyl-5-vinyl-pyridine, 2-methyl-3-ethyl-5-vinylpyridine; quinoline and isoquinoline with methyl substituted, N-vinylcaprolactam, N-vinylbutyrolactam, N-vinylpyrrolidone, vinyl imidazole, N-vinylcarbazole, N-vinyl succinimide, acrylonitrile, o-, m-, or p-aminostyrene maleimide, N-vinyloxazolidone, N, N-dimethylaminoethylvinyl ether, ethyl-2-cyanoacrylate, vinyl acetonitrile, N-vinylphthalimide. Also included are N-vinyl-thio-pyrrolidone, 3-methyl-1-vinyl-pyrrolidone, 4-methyl-1-vinyl-pyrrolidone, 5, methyl-1-vinyl-pyrrolidone, 3-ethyl-1-vinyl-pyrrolidone. , 3-butyl-l-vinyl-pyrrolidone, 3,3-dimethyl-1-vinyl-pyrrolidone, 4,5-dimethyl-l-vinyl-pyrrolidone, 5,5-dimethyl-1-vinyl-pyrrolidone, 3,3 , 5-trimethyl-1-vinylpyrrolidone, 4-ethyl-1-vinyl-pyrrolidone, 5-methyl-5-ethyl-1-vinyl-pyrrolidone, 3, 4, 5-trimethyl-1-vinyl-pyrrolidone and other N- substituted lower alkyl pyrrolidones. Another class of suitable ethylenically unsaturated monomers are substituted ethylene monomers, such as vinyl acetate, vinyl chloride, vinyl fluoride, vinyl bromide, vinylidene chloride, vinylidene fluoride, vinylidene bromide, acrylonitrile, methacrylonitrile, acrylic acid and corresponding amides and esters, methacrylic acid and corresponding amides and esters. Another class of acrylic and methacrylic acid derivatives is represented by substituted alkyl acrylate and methacrylate and substituted acrylamide and methacrylamide monomers. Examples include (meth) acrylates wherein the alkyl group is substituted with halogen, such as fluorine, chlorine or bromine; and nitro, cyano, alkoxy, haloalkyl, carbalkoxy, carboxy, amino, alkylamino derivatives and the like. Each of the substituted monomers can be a single monomer or a mixture having different numbers of carbon atoms in the alkyl part. In one embodiment, the monomers are selected from the group consisting of hydroxy (C2-C6) alkyl methacrylates, hydroxy (C2-C6) alkyl acrylates, dialkylamino (C2-C6) alkyl methacrylates, dialkylamino (C2-C6) alkylacrylates, dialkylamino (C2) - C6) alkyl methacrylamides and dialkylamino (C2-C6) alkylacrylamides. The alkyl part of each monomer may be linear or branched. Examples of methacrylate and alkyl acrylate monomers substituted with one or more hydroxyl groups in the alkyl radical, especially those where the hydroxyl group is in the β position (2-position) in the alkyl radical. Preferred are the methacrylate and hydroxyalkyl acrylate monomers in which the substituted alkyl group is a (C2-C6) alkyl, branched or unbranched. Among the methacrylate and hydroxyalkyl acrylate monomers suitable for use in the present invention are 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl methacrylate, l-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, l-methyl-2-hydroxyethyl acrylate, hydroxybutyl methacrylate and 2-hydroxybutyl acrylate. hydroxybutyl. The preferred methacrylate and hydroxyalkyl acrylate monomers are HEMA, l-methyl-2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate. A mixture of the last two monomers is commonly known as "hydroxypropyl methacrylate" or HPMA. Additional examples of substituted (meth) acrylate monomers are those monomers of methacrylate and alkyl acrylate with a dialkylamino group in the alkyl radical, such as dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate and the like. Other examples of substituted (meth) acrylate monomer are cyclic nitrogen-containing compounds (previously described) and methacrylamide and dialkylaminoalkyl acrylamide monomers, such as N, N-dimethyl-aminoethyl methacrylamide, N, N-dimethyl-aminopropyl methacrylamide, N, N-dimethylaminobutyl methacrylamide, methacrylamide N, N-di-ethylaminoethyl, N, N-diethylaminopropyl methacrylamide, N, N-diethylaminobutyl methacrylamide, N- (1, 1-dimethyl-3-oxobutyl) acrylamide, N- (1, 3-) acrylamide diphenyl-1-ethyl-3-oxobutyl), methacrylamide of N - (1-methyl-1-phenyl-3-oxobutyl) and 2-hydroxyethyl acrylamide, N-methacrylamide of aminoethylethyleneurea, N-methacryloxyethylmorpholine, N-maleimide of dimethylaminopropylamine and the like. Another group of ethylenically unsaturated monomers are C2o C50 (meth) acrylates formed from synthetic C2o alcohols C50. Generally, (meth) acrylates are formed by reacting C20 to C50 synthetic alcohols or ethoxylates thereof with a low-cut alkyl (meth) acrylate in the presence of a zirconium catalyst and a suitable inhibitor. Suitable alcohols or ethoxylates are available from Baker Petrolite, Inc., St. Louis, Missouri as Unilin ™ or Unithox ™ products. In one embodiment, at least the only monomer is a monomer product of (meth) acrylate prepared from an alcohol or C2o C50 ethoxylate.

Suitable examples of these monomers and the preparation thereof are disclosed and described in U.S. Patent No. 5,856,611 issued January 5. The elastomer compositions of the present invention also include a curing agent. The hardening agent is generally present from 0.1 to 30, preferably from 0.5 to 20, more preferably from 1 to 20 PHR. Suitable examples include sulfur as powdered, colloidal, precipitated, insoluble and dispersible sulfur; sulfur-containing organic compounds capable of releasing active sulfur with thermal dissociation such as tetramethylthiuram disulfide and 4,4'-dithiomorpholine; organic peroxides such as 2,5-dimethyl-2,5-di (t-butylperoxy) hexin, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,3-bis (t-butylperoxy) isopropylbenzene , dicumyl peroxide, dibutyl peroxide, 1, l-di-t-butylperoxy-3, 3, 5-trimethylcyclohexane, t-butylcumyl peroxide, t-butylperoxyisopropyl carbonate; metal oxides such as zinc oxide, magnesium oxide and lead oxide; quinonadioximes as p-quinone-oxime and p, p-dibenzoylquinone oxime; modified alkyl phenolic resins; polyisocyanates; polyamines such as triethyleneteramine, methylenedianiline and diethylenetriamine; metal soaps including sodium stearate and potassium stearate; carboxylic acids and ammonium salts of carboxylic acids such as adipic acid, octadecyldicarboxylic acid, ammonium stearate and ammonium adipate; acid anhydrides such as maleic anhydride, pyromellitic anhydride and dodecenylsuccinic anhydride; dithiocarbamic acids such as hexamethylenediamine carbamate and zinc dimethyldithiocarbamate; polyepoxides such as 1,6-hexanediol diglycidyl ether and ethylene glycol diglycidyl ether; and polyols such as 1,4-butanediol and 1,1,1-trimethylolpropane. As understood by those skilled in the art, the preferred hardening agent will depend on the type of elastomer compositions used. For example, if the elastomer is natural rubber, styrene-butadiene elastomer, butadiene elastomer, or nitrile elastomer, the hardening agent is generally sulfur, a compound containing organic sulfur, an organic peroxide, etc. If the elastomer is butyl rubber, the hardening agent is sulfur, quinonadiamine, etc. When the elastomer is urethane rubber, the hardening agent is a polyisocyanate, a polyamine, an organic peroxide, etc. When the elastomer is ethylene-propylene copolymer, the hardening agent is sulfur, organic peroxide, etc. When the elastomer is a fluoroelastomer / the hardening agent is an organic peroxide. The elastomer compositions of the present invention may also include a degradation accelerator to be used in combination with the curing agent.

The accelerator provides reduction of the degradation time, decrease of the degradation temperature and improvement in the properties of the degraded product. The degradation accelerator is generally present from 0.1 to 30, preferably from 0.5 to 20, more preferably from 1 to 10 PHR. Suitable examples of degradation accelerators include, but are not limited to, mechaptobenzothiazole, tetramethylthiuram disulfide, zinc dimethyldithiocarbamate, for use with a sulfur hardening agent.; and 1,3-butanediol dimethacrylate, ethylene glycol dimethacrylate, 1,4-butadienol dimethacrylate, 1,6-hexanediol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, , 2'-bis (4-methacryloldiethoxyphenyl) propane, trimethylolpropanetrimethacrylate, trimethylolpropanetriacrylate, pentaerythritoltrimethacrylate, N, N'-methylene (bis) acrylamide divinylbenzene, p-quinone-oxime, P, P'-dibenzoylquinone-oxime, triazinedithiol, triallyl cyanurate, triallyl isocyanurate (TAIC), bismaleimide for use with organic peroxide hardening agents. As stated above, a method for plasticizing an elastomer is also contemplated. The method includes providing an elastomer composition according to the present invention, wherein at least the polymeric material is present in an amount effective to plasticize the elastomer. Generally, at least the polymeric material is present from 2 to 100, preferably from 2 to 60, more preferably from 2 to 30 PHR. Also contemplated is a method for improving the processability of an elastomer, including: providing an elastomer composition according to the present invention, wherein at least the polymeric material is present in an effective amount to improve the processability of the elastomer. elastomer Generally, at least the polymeric material is present from 2 to 30, preferably from 2 to 20, more preferably from 2 to 10 PHR. The following examples are provided as an illustration of the present invention. EXAMPLE 1 Preparation of Ni Thread Rubber Elastomer Composition A mixture of elastomers containing: PHR Chemigum N615B 100 (Goodyear nitrile rubber - Akron, Ohio) Akro-Zin Bar 85 (85% zinc available from 5 Akrochem - Akron, Ohio) Flectol 3 tablets (Harwick processing medium - Akron, Ohio) Carbon black N 774 60 (from Cabot - Norcross, Georgia) WB 2222 (Structol antioxidant - Stow, Ohio) 1 Peroximon DCP40 6 (40% dicumyl peroxide from Akrochem - Akron, Ohio) mixed by combining the materials, in a cold laboratory mill for ten (10) minutes without exceeding a temperature of 50 ° C. No plasticizer was included in the elastomer composition. The composition of green elastomers was hardened into sheets for 100 mil tests at 160 ° C for 25 minutes. The hardened elastomer material was measured for Tg by DMTA, Shore A Hardness (ASTM) D2240), 100% elongation (ASTM D412), elongation @ break percentage (ASTM D412), tensile strength (ASTM D412) and Rip Cutting C (ASTM D624). The results are shown in Table 1. E.TEMPLO 2 An elastomer composition was prepared according to the procedure of Example 1, except that 20 PHR of Natrorez, a natural plasticizer derived from the resin mineral tar available from Harwick of Akron, Ohio, was added to the composition. The hardened elastomer material was measured for Tg by DMTA, Shore A Hardness, 100% elongation, elongation @ break percentage, tensile strength and Die Cut C. The results are shown in Table 1. EXAMPLE 3 Prepared an elastomer composition according to the procedure of Example 1, except that 20 PHR of Paraplex G 25, a polysaccharide plasticizer available by CP Hall of Chicago, Illinois, was added to the composition. The hardened elastomer material was measured for Tg by DMTA, Shore A Hardness, 100% elongation, elongation @ break percentage, tensile strength and Die Cut C. The results are shown in Table 1. EXAMPLE 4 Prepared an elastomer composition according to the procedure of Example 1, except that 20 PHR of lauryl methacrylate monomer (LMA) was added as a plasticizer to the composition, 7.5 PHR of DCP40 was used and the hardened elastomer was thermocured at 100 ° C. C for 70 hours in a pressurized air oven. The hardened / heat-cured elastomer material was measured for Tg by DMTA, Shore A Hardness, 100% elongation, elongation @ break percentage, tensile strength and Die Cut C. The results are shown in Table 1.

Table 1 The physical test of the elastomer compositions of Examples 1-4 illustrates that the elastomer composition of the present invention (Example 4) is plasticized in a comparable or more efficient manner. The elastomer composition of Example 4 has a lower Tg and a lower Shore A hardness than the plasticizer-free elastomer composition or those having conventional plasticizers (Examples 1-3). In addition, the lower PSI in the 100% elongation and the elongation percentage at break also indicate a more efficient plasticization of the elastomer composition of the present invention. The tensile strength and rip-off C is similar to the elastomer compositions with conventional plasticizers. EXAMPLES 5-8 Elastomer compositions were prepared as in Examples 1-4. The hardened elastomer compositions were tested for solvent resistance by weight loss after immersion in chloroform at 40 ° C for 70 hours. The results are described in Table 2 as percentage of weight of extractables, percentage of loss of plasticizer by weight and for Example 4, the percentage of loss of plasticizer after thermocuration. Examples 6 and 7 were not heat cured due to the unavailability of unsaturation in these molecules, during the thermocuration, which are necessary to increase the molecular weight of polymers.

Table 2 The solvent resistance test using chloroform as solvent shows "that the elastomer composition containing the polymerized poly-LMA in its place is better than the composition of elastomers containing Natrorez 25 and slightly better than the composition containing Paraplex G 25. However When the composition is heat-cured, the resistance improves even more. The availability of unsaturation in the poly-LMA allows the further polymerization of the AML which decreases the plasticizer removal from the elastomer composition.

EXAMPLE 9 Preparation of Fluoroelastomer Composition A mixture of elastomers containing: Piffi FLS 2650 (3M Co. fluoroelastomer - St. Paul, 100 Minnesota) Cri-D 82.5 (Cri-Tec activator, Inc. - Hanover, Mass.) TAIC (Mitsubishi Int '1 Corp. degradation accelerator, New York , NY) Carbon Black N 330 (Cabot - Norcross, Georgia) 30 DC 60 (60% dicumyl peroxide from Akrochem - Akron, Ohio) it was mixed by combining the materials in a Banbury mixer and mixing for 15 minutes without heating above a temperature of 100 ° C. No plasticizer was included in the composition of elastomers. The composition of green elastomers was hardened at -160 ° C in a laboratory press. The hardened elastomer material was measured for Tg by DMTA, Shore A hardness, 100% elongation, elongation @ break percentage, tensile strength and was observed for molding compatibility. The results are shown in Table 4. EXAMPLE 10 An elastomer composition was prepared according to the procedure of Example 9, except "that 10 PHR of Paraplex G 40, a polysaccharide plasticizer, available from C.P.

Hall of Chicago, Illinois, was added to the composition. The hardened elastomer material was measured for Tg by DMTA, Shore A hardness, 100% elongation, elongation @ break percentage, tensile strength and was observed for molding compatibility. The results are shown in the Table. EXAMPLE 11 An elastomer composition was prepared according to the procedure of Example 1, except "that 10 PHR of poly-LMA / SMA (95: 5) copolymer was added to the composition and the elastomer composition postulated according to the recommendations from the manufacturer, 3M Co. The poly-LMA / SMA copolymer (95: 5) was prepared as follows. A 5 liter reaction vessel was equipped with a thermometer, a temperature controller, a purge gas inlet, a water cooled reflux condenser with purge gas outlet, a stirrer and an addition funnel. To the addition funnel was added 3354.91 grams of a homogeneous monomer mixture of 168.39 grams of cetyl-stearyl methacrylate (SMA, 96.5% pure), 3134.52 grams of lauryl-myristyl methacrylate (LMA, 98.5% pure), 3.25 grams of Vazo-67 and 48.75 grams of dodecyl mercaptan. Thirty percent (1006.47 grams) of the monomer mixture in the addition funnel was added to the reaction vessel which was then flushed with nitrogen for 30 minutes before applying heat to bring the contents to the reaction vessel at 120 ° C. When the contents of the vessel reached 120 ° C, the remainder of the monomer mixture in the addition funnel was uniformly added to the reaction vessel for 60 minutes. At the end of the addition of the monomer mixture, the content of the reaction vessel was maintained at 120 ° C for 30 minutes. At the end of the 30 minute wait, the polymerization temperature was reduced to 105 ° C before adding the first of two discrete hunter shots of the initiator, each consisting of 6.50 grams of a Vazo-67. Thirty minutes after adding the first initiator hunter shot, the second initiator hunter shot was added to the reaction while maintaining the temperature of the contents of the reaction vessel at 105 ° C. Thirty minutes after the second shot of the initiator's hunter, the batch temperature was increased to 120 ° C and maintained for 30 minutes to ensure the total consumption of the initiator. The product thus formed had a polymer solids content of 97.7 weight percent (by GCP test), a viscosity of 920 cSt at 210 ° F and a molecular weight (Mw) of 24,700. The LMA / SMA product was tested for heat stability. The copolymer was added to a flask and heated in an inert atmosphere for about 24 hours at 450 ° F (232 ° C). Samples were taken with (0.5%) and without catalyst (dicumyl peroxide). The results follow in Table 3 Table 3 As illustrated in Table 3, the stability at 232 ° C was excellent. The elastomer product was measured for Tg by DMTA, Shore A Hardness, 100% elongation, elongation @ break percentage, tensile strength and was observed for molding compatibility. The results are shown in the Table. EXAMPLE 12 An elastomer composition was prepared according to the procedure of Example 1, except that 10 PHR of terminally unsaturated butyl acrylate oligomer (o-BA) was added as a plasticizer to the composition and the hardened elastomer composition was added. Made according to the manufacturer's recommendations, 3M Co.

The terminally unsaturated BA was prepared as follows. A 35% solution of butyl acrylate (BA) monomer in acetone containing di-t-butyl peroxide (2% based on monomer) was supplied at 5 ml / min through a high pressure / temperature reactor at 275 ° C. ° C and 3500 psi. The resulting sample was distilled in a "rotovap" to remove residual BA monomer and acetone. A proton NMR spectrum of this product was consistent with the expected structure and was combined with mass spectroscopy (MS) indicating that 70% of the oligomer chains possess terminal unsaturation. An FTIR spectrum of this material showed a carbonyl extension at 1730-1740 cm -1. The oligomer was a clear, colorless fluid having the following properties: Res. BA = 200 ppm Total solids = 99.3% Tg = -71 ° C Mw = 2100 * Mn = 930 * Mw / Mn = 2.3 Viscosity = 160 cps. * Molecular weights were determined with gel permeation chromatography using an o-BA standard. The hardened elastomer material was measured for Tg by DMTA, Shore A hardness, 100% elongation, elongation @ break percentage, tensile strength and was observed for molding compatibility. The results are shown in Table 4. Table 4 The elastomer composition of the present invention (Examples 11 and 12) has Tg and Shore A hardness comparable to the elastomer composition without plasticizer or conventional plasticizers (Examples 9 and 10). In addition, the lower PSI at the 100% elongation and the elongation percentage at break also indicate an efficient plasticization of the elastomer composition of the present invention and exhibit an improved processing facility. The resistance in the traction is similar to the compositions of elastomers with conventional plasticizers. The molding compatibility, that is, the ability of the plasticizer to remain in the composition of elastomers without a change in the position and / or migration (open) to the surface during molding. The elastomer compositions of the present invention exhibited compatibility with the fluoroelastomer considering that the elastomer composition containing Paraplex failed. EXAMPLES 13-16 Elastomer compositions were prepared as in Examples 9-12. The elastomer compositions were tested for solvent resistance by immersion in diesel fuel at 40 ° C for 100 hours. The resulting physicists were measured again and described in Table 5. Table 5 A comparison of the results presented in the Table 4 (before extraction) and those in Table 5 (after extraction) illustrate the increased resistance to extraction in the elastomer compositions of the present invention and the loss of compatibility of Paraplex 40 during molding / curing. the composition of elastomers. The elastomer compositions of the present invention show comparable or enhanced plasticization after the extraction of the diesel and the conventional elastomer composition shows a decrease in plasticization when comparing Table 4 (before extraction) and Table 5 (after the removal) .

Claims (20)

1. Rei indications 1. An elastomer composition comprising: (A) at least one elastomer; (B) a plasticizer comprising at least one polymeric material, having a weight average molecular weight (Mw) of 500 to 1,000,000, formed of at least one ethylenically unsaturated monomer and (C) a curing agent, wherein less the polymeric material is substantially permanent within the elastomer. The elastomer composition of claim 1, wherein at least the ethylenically unsaturated monomer is selected from acrylic acid, methacrylic acid and esters thereof. The elastomer composition of claim 1, wherein at least the polymeric material is formed of one or more monomers selected from Cl to C20 alkyl (meth) acrylates. 4. The elastomer composition of claim 1, wherein at least the polymeric material is formed of one or more monomers selected from (meth) acrylates of the C20 to C50-chyle. The elastomer composition of claim 1, wherein at least the polymeric material is formed of one or more monomers selected from C 1 to C 20 alkyl (meth) acrylates and one or more monomers selected from alkyl (meth) acrylates. C20 to C50. The elastomer composition of claim 1, wherein at least the polymeric material is a terminally unsaturated oligomeric (meth) acrylate formed from one or more (meth) acrylate monomers. The elastomer composition of claim 1, wherein at least the monomer is lauryl (meth) acrylate. 8. The elastomer composition of claim 1, wherein at least the polymeric material comprises a copolymer of lauryl methacrylate and stearyl methacrylate. The elastomer composition of claim 1, wherein at least the monomer is a styrene-butadiene elastomer, chloroprene elastomer, butyl elastomer, polybutadiene elastomer, nitrile elastomer, polyethylene elastomer, ethylene-elastomer. propylene, acrylic elastomer, silicone elastomer, fluoroelastomer, epichlorohydrin elastomer, polyalkanemer elastomer, polysulfide elastomer, urethane elastomer, mixtures or combinations thereof. 10. The elastomer composition of claim 2, further comprising one or more monomers selected from vinylaromatic monomers, cyclic monomers containing nitrogen and its thio analogs, substituted ethylene monomers, substituted hydroxyl methacrylate monomers and (meth) acrylates and ( meth) substituted algeryl acrylamides. 11. The elastomer composition of claim 1, further comprising a filler product. The elastomer composition of claim 11, wherein the filler product is selected from carbon black, carbon fiber, calcium carbonate, natural or synthetic silica, talc, mica, wollastonite, glass spheres and fiberglass . 13. The elastomer composition of claim 1, further comprising a degradation accelerator. A process for preparing an elastomer composition, comprising: (A) providing a blend of an elastomer, at least one ethylenically unsaturated monomer or a polymeric material having a weight average molecular weight (Mw) of 500 to 1,000,000 formed from at least one ethylenically unsaturated monomer and a curing agent and (B) hardening the elastomer composition, wherein during curing, at least the ethylenically unsaturated monomer, if present, is polymerized in place to form a composition of elastomers wherein at least the polymeric material is substantially within the elastomer. 15. The process of claim 14, wherein at least the ethylenically unsaturated monomer is selected from acrylic acid, methacrylic acid and esters thereof. 16. The process of claim 14, "which further comprises: (C) heat-cure or post-cure the hardened elastomer composition. 17. A method for plasticizing an elastomer, comprising: (A) providing an elastomer composition according to claim 1, wherein at least the polymeric material is present in an amount effective to plasticize the elastomer. 18. The method according to claim 17, wherein the polymeric material is present from 2 to 100 PHR. A method for improving the processability of an elastomer, comprising: (A) providing an elastomer composition according to claim 1, wherein at least the polymeric material is present in an effective amount to improve the ease of elastomer processing. The method according to claim 19, wherein the polymeric material is present from 2 to 30 PHR.