KR20000001269A - Elastic polymer composition of co-hardened rubber-thermo-plasticity - Google Patents

Abstract

PURPOSE: The thermoplastic, elastic polymer provides a composition having a bridge-bonded phase of acrylic rubber to be hardened by hardener and the phase of plasticity or the matrix of technical thermoplasticity substances like ester polymer, CONSTITUTION: The composition of a thermoplastic, elastic polymer has a phase of thermoplastic ester polymer and a phase of a bridge-bonded rubber containing a functional acrylic rubber of which one is a triple polymer of ethylene-alkyl acrylate-carboxyl acid; that is vulcanized by hardener and vulcanized kinetically more than two with uniquely low LTB.

Description

Co-cured rubber-thermoplastic elastomer composition

The present invention relates to thermoplastic elastomers made from two or more functionalized acrylic rubbers. Curing agents available in small or large amounts are generally cured through the formation of covalent or ionic bonds and include compounds such as various peroxides, magnesium oxides and various epoxidized soybean oils. The present invention also relates to the dynamic vulcanization of two or more functionalized acrylic rubbers in the presence of thermoplastic polymers such as ester polymers. The dynamically vulcanized composition preferably has a single low temperature embrittlement point.

Thermoplastic elastomers are materials having both thermoplastic and elastic properties, which can be processed as thermoplastics but have the physical properties common to elastomers. Molded articles can be made from thermoplastic elastomers by extrusion, injection molding or compression molding without the time-consuming curing steps required by conventional vulcanizates. Also, thermoplastic elastomers can be reworked without the need for regeneration and many thermoplastic elastomers can also be thermally welded.

Patel's US Pat. No. 5,300,573 relates to thermoplastic elastomers comprising a single acrylic rubber and polyester resin blend covalently crosslinked.

The present invention generally relates to blends of two or more functionalized acrylic rubber components cured in the presence of industrial thermoplastics and curing agents. The functional groups may be the same or different. One of the functionalized acrylic rubbers is preferably a terpolymer derived from ethylene, alkyl acrylates and unsaturated carboxylic acids and upon curing the composition unexpectedly has only a single low temperature embrittlement point. The degree of cure of two or more acrylic rubbers is generally at least 80%. When cured, thermoplastic elastomers have good balanced properties such as good low temperature physical properties and low oil swellability.

The thermoplastic elastomer composition of the present invention generally contains a matrix or plastic phase of an industrial thermoplastic polymer compatible with at least two functionalized acrylic rubber components.

Suitable thermoplastic polymers include various ester polymers such as polyester, copolyesters, polyester block copolymers or polycarbonates, such as epoxy endcapped derivatives thereof and mixtures thereof. The various polyesters may be aromatic or aliphatic or a combination thereof and generally have an aromatic acid having a total of about C _8-15 or an aliphatic acid having a total of C _2-12 and preferably a C _3-15 and a total of C _{2- 12} and preferably derived directly or indirectly from the reaction of diols such as glycols having about C _2-4 . In general, aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polynaphthalene phthalate and the like and end-capped epoxy derivatives thereof (for example monofunctional epoxy polybutylene terephthalate) are preferred. Various polycarbonates are also available and carboxylic acid esters can be used. Suitable polycarbonates are those based on bisphenol A, ie poly (carbonyldioxyl, 4-phenyleneisopropylidene-1,4-phenylene). The various ester polymers also contain one or more polyester blocks and one or more rubber blocks, such as glycols having C _2-6 (eg polyethylene glycol) or polyethers derived from alkylene oxides having C _2-6 Block polyesters, such as the like. Preferred block polyesters are polybutyleneterephthalate-b-polyethylene glycols commercially available from DuPont as Hytrel.

The amount of at least one industrial thermoplastic resin is generally about 5-95 parts by weight, preferably about 15-60 parts by weight, preferably about 20-40 parts by weight, based on a total of 100 parts by weight of two or more functionalized acrylic rubbers. .

Given two or more functionalized acrylic rubber components they are generally compatible with each other and also with industrial thermoplastics. Acrylonitrile containing rubbers such as nitrile rubbers, for example nitrile rubbers, is excluded or substantially free of the present invention (ie less than 5% by weight, less than 3% by weight, 1% by weight based on a total of 100 parts by weight of acrylic rubber). Less than%, preferably 0% by weight). Two or more functionalized acrylic rubber components may be derived from alkyl acrylates wherein the alkyl moiety has C _1-10 and C _1-3 is preferred. Specific examples include polymers such as ethyl acrylate, butyl acrylate, ethyl-hexyl acrylate and the like. Other suitable acrylic rubbers include copolymers of ethylene and alkyl acrylates mentioned above, wherein the amount of ethylene is preferably about 10-90 mole percent, based on, for example, the total moles of ethylene and acrylate repeating groups in the copolymer, It is preferably as high as about 30-70 mole%, preferably about 40-60 mole%, resulting in a rubber having polar and nonpolar portions.

Two or more acrylic rubbers have functional groups which may be acids, ie carboxyl groups, epoxy groups, hydroxy groups and the like. Two or more rubbers may have different functional groups and may be the same functional group. Such functionalized acrylic rubber components are obtained using various comonomers in the polymerization of the above-mentioned acrylic polymers. Suitable comonomers for adding hydroxyl groups include unsaturated alcohols having about C _2-20 , preferably about C _2-10 . A specific example of hydroxy functionalized acrylic rubber is Hytemp 4404 from Nippon-Zeon. Suitable comonomers for adding pendant epoxy groups are oxirane acrylates in which the oxirane group may contain about C _3-10 and the ester group of acrylates have C _1-10 (specific example is glycidyl acrylate). Unsaturated oxiranes such as Another group of unsaturated _oxiranes are various oxirane alkenyl ethers in which the oxirane group has about C _3-10 and the alkenyl group may also have about C _3-10 and specific examples are allyl glycidyl ether to be. Examples of epoxy functionalized acrylic rubbers include acrylate AR-53 and acrylate AR-31 from Nippon-Zeon, and the like. Suitable comonomers for adding pendant carboxylic acid groups include unsaturated acids having 2 to about 15, preferably 2-10 carbon atoms. Examples of acid functionalized acrylic rubbers include ethylene-acrylate-carboxylic acid terpolymers such as Vamac G from DuPont and various carboxyl functional acrylates from Nippon-Zeon. The amount of functional groups in some acrylic polymers may be up to about 10 mole percent, preferably about 0.5-6 mole percent, preferably about 1-4 mole percent of the polymer, the total repeating group.

Unexpectedly it has been found that when using ethylene-alkyl acrylate-carboxylic acid terpolymers, two or more acrylic rubber blends show only one, i.e., a single low temperature embrittlement point (LTB) and impart good low temperature properties to the thermoplastic elastomer. Single LTB is ASTM Test No. According to D-746 it is generally below -20 ° C, preferably below -30 ° C, preferably below -40 ° C. Moreover, such terpolymer blends have good oil resistance, ie low oil swelling. This oil swelling value is at least 20 or 30%, preferably at least 40, 50 or 60% lower than the oil swelling value of the acrylic terpolymer. ASTM Test No. 3 using ASTM Reference Oil 3 for 70 hours at 125 ° C. According to D-471 the oil swelling value is generally about 20-65, preferably about 25-40, 45 or 50. The combination of low oil swelling values and a single low temperature embrittlement point is so desirable that thermoplastic elastomer compositions are available for commercially desirable end products. For example, various seals, gaskets and the like preferably have a low oil swelling value of 40 or less and a single low temperature embrittlement point (ie -20 ° C. or less).

It is highly desirable to use terpolymers as one of the functionalized acrylic rubber components. Such terpolymers are generally about 35-80 mol%, preferably about 45-55 mol%, based on the total number of repeat groups in the terpolymer, generally about 0.5-10 mol%, preferably about It contains 2-8 mole% acid repeat groups and generally about 10-60 mole%, preferably about 37-50 mole% alkyl acrylate repeat groups. Acid repeat groups are generally derived from acrylic acid or methacrylic acid. Specific commercial compounds are generally Vamac G from DuPont having about 50 mol% ethylene, about 45 mol% methyl acrylate and about 5 mol% acrylic acid. The amount of terpolymer is generally important for obtaining good oil swelling values and very desirable properties of a single low temperature embrittlement point. Thus, the amount of terpolymer used is generally about 25-75, preferably about 40-60, preferably about 45-50 parts by weight based on a total of 100 parts by weight of acrylic rubber.

An effective amount of one or more curing agents is used to co-cure the functionalized acrylic rubber and obtain appropriate thermoplastic elastomeric properties. Such effective amounts generally result in a degree of cure of at least about 80%, preferably at least about 90-95%, preferably at least about 97%, 98%, 99% and even 100%, ie full cure. Curing degree is easily measured by the amount of acrylic rubber which does not dissolve in toluene at 20 ° C. Suitable crosslinkers are covalent or ionic bonds with reactive functional groups to cure two or more functionalized acrylic rubbers. Examples of such crosslinkers include various isocyanates such as toluene diisocyanate, various isocyanate terminated polyester prepolymers, various polyols such as pentaerythritol or diols such as bisphenol A, various polyamines such as methylene dianiline and diphenyl guanidine And various epoxides such as diglycidyl ether of bisphenol A and various epoxidized oils such as soybean oil.

When, but not always, epoxidized oils are used, they contain two or more internal oxirane groups and usually, but not always, some unsaturated moiety. "Inner" means that the oxirane group does not bind to the terminal or terminal carbon atoms of the oil molecule and often does not partially bond to either of the two terminal carbon atoms of each terminal portion of the oil molecule. Upon heating, the ring opens and reacts with the acrylic rubber to crosslink or cure it. Epoxidized oils are generally known in the industry and literature and are generally derived from plants, animals or petroleum such as vegetables. Oils are generally saturated fatty acids and / or preferably unsaturated fatty acids. Epoxidized oils also include glycerides of various fatty acids, such as linseed oil, which are glycerides of linolenic acid, oleic acid and unsaturated linoleic acid and saturated fatty acids. The various fatty acids generally contain about C _10-25 , more preferably about C _14-21 . Generally the iodine value of the epoxidized oil is about 0.5-12, preferably about 1-3 or 5 or 9. The weight of the oxirane groups in the oil can vary widely, ranging from only about 1-2, more preferably from 3-4% by weight to about 10, 12 or even 15% by weight. Preferred oils include epoxidized soybean oils such as Paraplex G-62 from CP Hall Company.

Curing agents are generally used in amounts of about 0.5-12 parts by weight per 100 parts by weight of two or more functionalized acrylic rubbers. If the functionalized rubber has different functional groups thereon, the self-curing of the rubber occurs slightly (ie without hardening caused by the hardener), requiring a smaller amount of hardener, such as about 1-3 parts by weight. When the acrylic rubber functional groups are the same, larger amounts of hardener are generally required, such as about 1-5 parts by weight.

An accelerator is optionally used to reduce the curing time of two or more functionalized acrylic rubbers. Suitable promoters include various fatty acid salts that do not crosslink the functionalized rubber compound. Often these compounds also act as lubricants. Fatty acid salts generally have 12 or 14 to 20 or 25 carbon atoms. Suitable cations include alkali and alkaline earth metals, ie groups 1 and 2 of the periodic table and various transition metals, for example groups 11 and 12 of the periodic table. Specific examples of accelerators include salts of sodium, potassium, magnesium, calcium, zinc and the like and mixtures of fatty acids such as palmitic acid, stearic acid, oleic acid and the like, with potassium stearate and magnesium stearate being preferred. The amount of accelerator is in small amounts up to 10 parts by weight, preferably from about 0.1 to 4 or 5 parts by weight and often from about 0.5-1.5 parts by weight of all functionalized acrylic rubbers.

The composition of the present invention may also contain various additives in conventional amounts or in suitable amounts. When epoxidized oils are used as hardeners, various flame retardants can be used, for example, to prevent excessively rapid hardening, such as some quaternary ammonium salts. Other additives include different antioxidants, different UV stabilizers such as hindered amines, different processing aids, different colorants or pigments such as titanium dioxide, clays, silica, carbon black, talc, zinc oxide and the like. Such as various reinforcing or fillers, various flame retardants and various plasticizers such as non-reactive sulfonamides and trimellitates and various phthalate esters (eg dioctyl esters).

The co-cured thermoplastic rubber composition of the present invention is preferably cured through dynamic vulcanization. Dynamic vulcanization means vulcanizing the acrylate rubber of the composition of the present invention under high shear at curing temperatures. Thus, the rubber is generally crosslinked while blended with the thermoplastic polyester polymer. Thus, the rubber may simultaneously crosslink and disperse as microparticles of “microgels” in the thermoplastic matrix (eg polyester) or form a plastic phase and a co-continuous phase or a combination thereof. High shear sources include Brabender mixers, Banbury mixers, extruders including twin screw extruders, and the like. A unique feature of the composition of the present invention is that as the elastomeric rubber portion is crosslinked, the composition can nevertheless be processed and reworked with conventional thermoplastic processing techniques and equipment such as extrusion, injection molding, compression molding and the like. An advantage of the thermoplastic elastomers of the present invention is that the pieces, fragments and the like can be collected and reprocessed. However, two or more acrylate polymers are not phase separated and do not contain, for example, an internal phase and an external phase and the external phase may or may not contain graft binding monomers. That is, the present invention is intended to substantially reduce such geometric (eg outer shell-inner core) acrylic compounds (ie less than 5%, less than 3%, less than 1% by weight, preferably such compounds per 100 parts by weight of all acrylic rubber). Free).

Dynamically vulcanization generally involves adding co-cured acrylic rubbers and functionalized rubber components, various accelerators to a high shear mixing device such as Brabender and mixing the composition by heating to a temperature above the melting point of the thermoplastic. The mixing temperature is generally about 180-260 ° C, preferably about 220-240 ° C. The composition is mixed until the torque curve is flat (at which time the composition is mixed for a further short time, for example about 2 minutes). After mixing and curing, the thermoplastic elastomer composition was separated in a Brabender mixer, cold pressed into a pancake shape and then compression molded into a test flake.

Suitable uses of the thermoplastic elastomers of the present invention include useful molded, extruded or molded articles such as vehicle parts (eg automobiles) such as seals, tubes, hoses, gaskets, membranes, bellows and the like.

The present invention will be better understood by reference to the following examples which are intended to illustrate the invention but are not intended to limit the scope thereof.

Example

A blend of polybutylene terephthalate containing two acid functionalized acrylic rubbers was prepared and cured. Three controls and two or more functionalized cured acrylic polymer blends of the present invention were prepared according to the method shown in Table 1.

Dynamic Vulcanizers Containing PBT 2002 and Acrylate / VAMAC-G Blends Substance (% by weight) One 2 3 4 5 6 7 8 PBT 2002 ¹ 33.3 33.3 33.3 33.3 33.3 33.3 33.3 33.3 AR-71 ² 100 - - - - - - - R40-130A ³ - 100 - 75 50 25 90 10 Vamac-g ⁴ - - 100 25 50 75 10 90 Naugard 445 ⁵ 2 2 2 2 2 2 2 2 Kemamide S-221 ⁶ 2 2 2 2 2 2 2 2 Magnesium oxide - 6 6 6 6 6 6 6 Magnesum Stearate - One One One One One One One Hytemp NPC-50 ⁷ 6 - - - - - - - Potassium stearate 4 - - - - - - - Note: R40-130A is similar to AR71 and contains carboxyl groups UTS, psi 1230 2164 2011 1617 2216 2561 2254 2256 % Elongation 250 271 443 395 336 246 217 327 M 100% 625 1610 1045 983 1376 1652 1680 1210 Residual tension (%) 13 25 25 18 20 25 30 18 OS (70H, 177 ℃) 12 7 103 31 49 59 14 79 CS (70H, 150 ℃) 63 86 93 92 93 87 93 93 LTB, C -18 -18 <-60 -18 -36 -48 -18 <-60 SHORE A 77 79 70 75 77 80 81 73 Aging hot air at 177 ° C for 168 hours UTS, psi 1890 1310 1428 1011 1685 1836 1513 1636 % Elongation 175 139 195 165 274 193 177 260 M 100%, psi 1030 1244 1290 990 1410 1520 1300 1335 Shore a 78 83 73 80 77 77 84 74

Note: Polybutylene terephthalate from ¹ -Celenese Corporation

^2- Vinyl Chloroacetate Functionalized Acrylic Elastomer from Nippon Zeon ³

Carboxylic acrylate rubbers with carboxyl functionality from Nippon Zeon ⁴

-Nicpon Zeon Carboxylic Acid-Ethylene-Methylacrylate Terpolymer ⁵

-Alkylated biphenyl amine antioxidants from Uniroyal Chemical Co. ⁶

-Witco Wax Lubricant ⁷

50% active masterbatch of -quaternary ammonium salt

The composition was prepared using a Brabender mixer. The indicated functionalized acrylic rubber and various additives were ground and melt mixed and then thermoplastics were added. Once the thermoplastic melted, accelerators were added and mixed. Magnesium oxide curing agent was then added and mixed until the torque curve was flat. The mixing was continued for another 1-2 minutes.

Dynamic vulcanizates were pressed into pancake shapes and compression molded into flakes. Various physical tests were performed and their properties are listed at the bottom of Table 1.

As apparent from Table 1, generally improved ultimate tensile strengths were obtained. Examples 4-8 unexpectedly had only one cold brittle point (LTB).

The thermoplastic elastomer composition was prepared from the method of Table 2 shown below in a manner similar to that indicated above for Table 1.

Curing Agent Screening Substance (% by weight) 9 10 11 12 13 14 15 16 PBT 2002 33.3 33.3 33.3 33.3 33.3 33.3 33.3 33.3 R40-130A 100 - 50 50 50 50 50 50 Vamac-g - 100 50 50 50 50 50 50 Naugard 445 2 2 2 2 2 2 2 2 Kemamide S-221 2 2 2 2 2 2 2 2 Magnesium oxide 6 6 6 - - - - - Magnesum Stearate One One One - - One - - NPC-50 - - - 6 - - - - Potassium stearate - - - 4 - - - - Paraplex G-62 ¹ - - - 8 - - - - Trisamino ² - - - - 1.5 - - - Mondur E-501 ³ - - - - - 6 - - Corcat P-16 ⁴ - - - - - - 4 - LICA 44 ⁵ - - - - - - - 3 Physical properties UTS, psi 2164 2010 1690 1340 1570 1520 650 1320 % Elongation 271 443 335 125 145 205 106 125 M 100% 1610 1045 1250 1080 1040 750 640 1060 Residual tension (%) 25 25 13 - 15 15 - - OS (70H, 177 ℃) 7 103 38 26 29 36 29 28 CS (70H, 150 ℃) 86 93 70 51 84 72 76 72 LTB, C -18 <-60 -38 - - - - - SHORE A 79 70 81 80 82 74 72 80

Note: ^1- Epoxidized soybean oil from CPHall Company

² -Amine Curing Agent of Angus Chemical Company ³

-Prepolymer Isocyanate ^{4 from} Mobay Chemical Company

-Texaco Hardener ⁵

-Alkoxy titanate from Kenrich Petrochemical Company

As is apparent from Table 2, good physical properties were obtained for the functionalized acrylic rubber, ie Examples 11-16. Moreover, Example 11 had a very low embrittlement temperature (ie -38 ° C) and the remaining Examples 12-16 also had a very low single embrittlement temperature. The oil swelling values of Examples 11-16 were very low compared to those using only terpolymers, ie Example 10.

Various thermoplastic elastomer compositions were prepared and tested from the method of Table 3 in a manner similar to that indicated above for Table 1.

Substance (% by weight) 17 18 19 20 21 22 23 24 PBT 2002 33.3 33.3 33.3 33.3 33.3 33.3 33.3 33.3 Acrylate AR-31 ¹ 50 50 - - 50 50 - - Acrylate AR-53 ² - - 50 50 - - - - Vamac-g 50 50 50 50 - - 50 50 Acrylate R40 130A2 - - - - 50 50 - - Hytemp 4404 ³ - - - - - - 50 50 Potassium stearate 4 4 4 4 4 4 4 4 Hytemp NPC-50 - 6 - 6 - 6 - 6 Paraplex G-62 - 4 - 4 - 4 - 4 Initial physical properties UTS, psi 1240 1610 1130 1310 1540 1410 1250 9606 % Elongation 150 140 150 395 336 246 217 327 M 100% 760 1030 750 990 960 1260 1080 910 Residual tension (%) - 13 11 15 23 - - - OS (70H, 177 ℃) 36 25 34 24 5 10 38 43 CS (70H, 150 ℃) 64 54 57 46 82 58 61 63 CS (annealed) 67 48 47 40 - - 53 57 -40C LTB test P P P P F F P P SHORE A 67 75 66 74 87 83 74 74

Note: ¹ -epoxy functionalized ethyl acrylate

² -epoxy-functionalized ethyl acrylate ³

-Hydroxy functionalized ethyl acrylate from Nippon Zeon

As apparent from Table 3, Examples 21 and 22, which do not contain an ethylene-ethyl acrylate-carboxylic acid terpolymer, did not achieve a -40 ° C low temperature embrittlement point. Rather, it cracked before reaching this temperature. Examples 17-20 and 23 and 24 had a single low temperature embrittlement point. The oil swelling values of Examples 17-20 and 23-24 were also very low.

While the best and preferred embodiments have been exemplified in accordance with the patent law, the scope of the invention is not limited thereto but by the scope of the claims.

Unexpectedly it has been found that when using ethylene-alkyl acrylate-carboxylic acid terpolymers, two or more acrylic rubber blends show only one, i.e., a single low temperature embrittlement point (LTB) and impart good low temperature properties to the thermoplastic elastomer.

Claims (15)

Single low temperature embrittlement comprising a crosslinked rubber phase comprising a thermoplastic ester polymer phase and at least two dynamically vulcanized functional acrylic rubbers vulcanized with a curing agent, one of which is an ethylene-alkyl acrylate-carboxylic acid terpolymer Thermoplastic elastomer composition having a point. The method of claim 1, wherein the ester polymer is polyester, copolyester, polyester block copolymer, polycarbonate, epoxy end capped derivatives or combinations thereof and the amount of the ester polymer per 100 parts by weight of the at least two acrylic rubbers. About 5-95 parts by weight and the amount of the terpolymer is about 25-75 parts by weight per 100 parts by weight of the at least two acrylic rubbers, having a degree of cure of at least 80%. The terpolymer of claim 2 wherein at least one of the functionalized rubbers is derived from an alkyl acrylate and the alkyl group has C _1-10 and the functional group is carboxyl, epoxy, hydroxyl or a combination thereof and the terpolymer Thermoplastic elastomer having about 35-80 mol% ethylene, about 10-60 mol% acrylate and about 0.5-10 mol% carboxylic acid. 4. The thermoplastic elastomer composition of claim 3, wherein the thermoplastic elastomer composition has an oil swell value less than the oil swell value of the terpolymer. The method of claim 4 wherein the ester polymer is the polyester and the amount of the ester polymer is about 20-40 parts by weight per 100 parts by weight of the at least two acrylate rubbers and the tripolymer is about 45-55 mole% of ethylene, about A thermoplastic elastomer composition having a curing degree of at least 90% having 37-50 mol% of acrylate and about 2-8 mol% of carboxylic acid and the amount of the terpolymer is about 40-60 parts by weight per 100 parts by weight of the at least two acrylate rubbers. . 3. The thermoplastic elastomer composition according to claim 2, wherein the single low temperature embrittlement point is -20 deg. The thermoplastic elastomer composition according to claim 5, wherein the single low temperature embrittlement point is below −40 ° C. and the oil swelling value is 30% less than the tripolymer oil swelling value. Blending two or more functional-containing acrylic rubbers with a thermoplastic ester polymer and a curing agent, wherein at least one of the acrylic rubbers is an ethylene-alkyl acrylate-carboxylic acid terpolymer Dynamically vulcanizing the acrylate rubber and preparing a thermoplastic elastomer composition having a single low temperature embrittlement point Method for producing a thermoplastic elastomer composition comprising a. The method of claim 8, wherein the ester polymer is polyester, copolyester, polyester block copolymer, polycarbonate, epoxy end capped derivatives or combinations thereof and the amount of the ester polymer is 100 weight of the at least two acrylic rubbers. About 15-6 parts by weight and the amount of the terpolymer is about 25-75 parts by weight per 100 parts by weight of the two or more acrylic rubbers and the thermoplastic elastomer composition is cured to a degree of curing of 80% or more and the thermoplastic and rubber phases are Manufacturing said thermoplastic elastomer composition to have it. The amount of the curing agent of claim 9, wherein the degree of cure is at least 90% and the terpolymer has about 35-80 mol% ethylene, about 10-60 mol% acrylate and about 0.5-10 mol% carboxylic acid. And producing a thermoplastic elastomer having about 0.5-12 parts by weight per 100 parts by weight of said at least two acrylic rubbers and having an oil swelling value of at least 30% less than the oil swelling value of said terpolymer. The polymer of claim 10 wherein the polymer is the polyester and the single cold embrittlement point is below -20 ° C. and one of the acrylic rubbers is a functionalized acrylic acrylate and the alkyl moiety has C _1-10 and the functional group is Carboxyl, epoxy or hydroxyl or combinations thereof. The method of claim 11, wherein the single low temperature embrittlement point is below −40 ° C. A combination of dynamically vulcanized acrylic rubber and thermoplastic ester polymer comprising at least two functionalized acrylic rubber blends cured with a curing agent, wherein the functional groups are carboxyl groups, epoxy groups, hydroxyl groups or combinations thereof The amount of the functional group is about 10 mol% or less based on the total number of repeating units in the functionalized acrylic rubber and the curing degree of the cured rubber is about 80-100% as measured by weight percent insoluble in toluene at 20 ° C. Thermoplastic Elastomer Composition. The method of claim 13, wherein the ester polymer is polyester, copolyester, polyester block copolymer, polycarbonate, epoxy end capped derivatives or combinations thereof and the amount of the ester polymer is 100 weight of the at least two acrylic rubbers. About 15-60 parts by weight and at least one of the acrylic rubbers is an ethylene-alkyl acrylate-carboxylic acid terpolymer and the amount of the terpolymers is about 25-75 parts by weight per 100 parts by weight of the two or more acrylic rubbers and A thermoplastic elastomer composition having a single cold embrittlement point of -20 ° C. or less, wherein one alkyl group is an alkyl acrylate having C _1-10 . 15. The method of claim 14 wherein the ester polymer is polyester and the terpolymer has about 35-80 mol% ethylene, about 10-60 mol% acrylate and about 0.5-10 mol% carboxylic acid and the degree of cure is about 90-100% thermoplastic elastomer composition.