JPH0579256B2 - - Google Patents

Description

[Detailed description of the invention]

a. Industrial Application Field The present invention relates to a thermoplastic elastomer composition that is highly flexible and has improved compression set. b. Prior Art Thermoplastic polyester elastomers are multi-block copolymers having polyester and polyether repeating units or polyester and polyester in the polymer main chain, and have excellent mechanical properties, heat resistance and oil resistance. However, the polyester elastomer
Although it has the above-mentioned excellent features, it has drawbacks that limit the expansion of its applications. That is, as an elastomer, it has high hardness and poor flexibility and compression set. In order to improve this and make the material flexible, it is necessary to increase the content of soft segments in the polymer. However, it is known that when the content of soft segments is increased in the polyester elastomer, the strength decreases significantly and the heat resistance and oil resistance are also inferior. Another known softening method is to add a softener, but this method has the disadvantage that the softener bleeds during use. As a method for improving the above-mentioned drawbacks and softening thermoplastic polyester elastomers, a method is proposed in which a polystyrene-type block copolymer is blended into polyester elastomers to soften them (Japanese Patent Laid-Open No. 50-82162
), and a method of softening a polyether ester block copolymer by blending an ionomer resin in which a mono- to trivalent metal is added to a copolymer of α-olefin-α,β-unsaturated carboxylic acid (special method). 1977-
184251) is proposed. However, polyetherester elastomers softened by these methods have a drawback of high compression set. In addition, as a method for improving the compression set of thermoplastic elastomers, Collan et al.
Chemistry and Technology 53 , 141 (1980)
In order to improve the compression set of a composition consisting of polypropylene and ethylene-propylene rubber,
We propose a method called dynamic addition. However, this method involves kneading rubber and resin in a high-temperature molten state and crosslinking the rubber, but the time required for crosslinking is long and the physical properties are affected by the conditions during dynamic vulcanization. However, the disadvantage is that the quality of the product is not stable. Furthermore, by melt-blending acrylonitrile-butadiene copolymer or styrene-butadiene copolymer containing a carboxyl group and a polyvalent metal oxide to a polyether ester elastomer, it is possible to create a polyester elastomer that is flexible and has improved compression set. A method for obtaining an ether ester elastomer has been proposed (Japanese Patent Application Laid-open No. 39457/1983). However, this method has limitations such as the limited rubber components that can be used and the limited amount of the rubber component to 5 to 30% by weight, and the compression set of the obtained polyetherester elastomer is still insufficient. There is a problem. c Problems to be solved by the invention As described above, polyester elastomer has excellent mechanical properties, heat resistance, and oil resistance.
Although it is desired to expand its use, it has the drawback of poor flexibility and compression set. d Means for Solving the Problems As a result of intensive research in view of the above points, the present inventors added rubber (B) as a means to soften polyester elastomer (A), and added rubber (B) to the rubber (B). We have discovered that a thermoplastic elastomer composition with excellent flexibility and compression set can be obtained by adjusting the content of the rubber component crosslinked with a specific crosslinking monomer to a specific value, and we have developed this book. (A) 25 to 95% by weight of the polyester elastomer component
(B) a rubber crosslinked with at least one crosslinkable monomer selected from divinylbenzene, diallyl phthalate, dilyl fumarate, and trimethylolpropane triacrylate, containing a gel content of 20% or more; Rubber component 75-5
The object of the present invention is to provide a thermoplastic elastomer composition obtained by dispersing and mixing % by weight. The polyester elastomer (A) of the present invention is a polyester block copolymer, in which a high melting point crystalline segment (C) mainly composed of aromatic polyester units and an aliphatic polyether unit a and/or aliphatic polyester unit
It has a low melting point polymer segment (D) mainly consisting of (b). The aromatic polyester unit of the high melting point crystalline segment (C), which is the hard segment used above, is formed from an acid component and a glycol component, and this acid component is substantially composed of terephthalic acid and/or 2,6 - naphthalene dicarboxylic acid. In addition to terephthalic acid or 2,6-naphthalene dicarboxylic acid, small amounts of other aromatic dicarboxylic acids such as isophthalic acid or aliphatic dicarboxylic acids such as adipic acid, sebacic acid, cyclohexane-1,4-dicarboxylic acid, and dimer acid are also used. An acid may be used in combination. The glycol component forming the aromatic polyester unit is a glycol having 2 to 12 carbon atoms, such as ethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexanediol, and decanediol. The lower limit of the melting point of the high melting point crystalline segment (C) is not particularly limited, but is generally preferably 150°C or higher, particularly preferably 180°C or higher. Furthermore, the aliphatic polyether unit (a) constituting the low melting point polymer segment (D), which is the above-mentioned soft segment, is formed of polyalkylene glycol having an average molecular weight in the range of about 400 to 600, The polyalkylene glycol is, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or polyethylene glycol-polypropylene glycol block copolymer, with polytetramethylene glycol being particularly preferred. These can be used alone or as a mixture as long as the ratio of carbon number to oxygen number is 2.0 to 4.5. The aliphatic polyester unit (b), which is another unit constituting the low melting point polymer segment (D), mainly consists of an aliphatic dicarboxylic acid and a glycol. Succinic acid, adipic acid, sebacic acid,
It is decanedicarboxylic acid. In addition to the above aliphatic dicarboxylic acids, a small amount of aromatic dicarboxylic acids such as isophthalic acid may be used in combination. Further, the glycol component forming the aliphatic polyester unit (b) is a glycol component having 2 to 12 carbon atoms, and is the same as the glycol component exemplified as the glycol component forming the aromatic polyester unit of the high melting point crystalline segment (C). It is similar. The aliphatic polyester unit (b) is obtained by polycondensing the aliphatic dicarboxylic acid and the glycol component in a conventional manner, and may be a homopolyester or a copolyester, or may be obtained by ring-opening a cyclic lactone. It may also be a polylactone obtained by polymerization, such as poly-ε-caprolactone. The upper limit of its melting point is not particularly limited, but is generally preferably 130°C or lower, particularly preferably 100°C.
It is as follows. The composition ratio of the high melting point crystalline segment (C) which is a hard segment and the low melting point polymer segment (D) which is a soft segment in the polyester elastomer (A) used in the present invention is 95/5 to 95/5 by weight. 5/95
It is preferable that More preferably 70/30
~30/70. Further, as the polyester elastomer (A), an elastomer having a softening point of 100°C or higher is particularly suitable. A polyester block copolymer particularly preferably used as the polyester elastomer (A) of the present invention uses polytetramethylene terephthalate, polytrimethylene terephthalate-2,6-naphthalate as the high melting point crystalline segment (C),
It is formed using an aliphatic polyester such as polytetramethylene glycol, polytetramethylene adipate, poly-ε-caprolactone, etc. as the low melting point polymer segment (D). Further, polycarboxylic acids, polyfunctional hydroxy compounds, oxyacids, etc. may be copolymerized as part of dicarboxylic acids and glycols. The polyfunctional component is copolymerized in a range of 3 mol% or less,
Effectively acts as a viscosity increasing component. Examples of the polyfunctional component include trimellitic acid, trimesic acid, pyromellitic acid, benzophenonetetracarboxylic acid, butanetetracarboxylic acid, glycerin, pentaerythritol or their esters and acid anhydrides. The rubber (B) which is another component used in the thermoplastic elastomer composition of the present invention includes natural rubber, polyisoprene rubber, styrene-butadiene rubber, styrene-butadiene block copolymer rubber, polybutadiene rubber, and acrylonitrile rubber.
Butadiene rubber, chloroprene rubber n-butyl acrylate-butadiene copolymer, n-butyl acrylate-acrylonitrile-butadiene copolymer, 2-ethylhexyl acrylate-acrylonitrile-butadiene copolymer, etc. (meth)
diene rubber such as acrylic acid alkyl ester-butadiene copolymer, or non-diene rubber such as ethylene-propylene rubber, ethylene-propylene terpolymer rubber, acrylic rubber, fluorine rubber, or hydrogenated acrylonitrile-butadiene rubber; Hydrogenated rubbers such as hydrogenated styrene-butadiene block copolymer rubber can be mentioned. Particularly preferred among these are acrylonitrile-butadiene rubber and acrylic rubber. Among the above rubbers, those that can be produced by emulsion polymerization or those that can be made into latex by emulsifying a rubber solution are preferred. The rubber component (B) is produced by using at least one type selected from vinyl compounds containing carboxyl groups, epoxy groups, amino groups and hydroxy groups as a copolymerization component when producing the rubber component (B). It is preferable to use a produced rubber component modified with at least one selected from carboxyl groups, epoxy groups, amino groups, and hydroxy groups in place of the above-mentioned rubber component. Among these, the use of the carboxyl group-, epoxy-group or hydroxy group-modified rubber component is preferred because the mechanical properties of the thermoplastic elastomer composition are improved. Examples of the monomer containing a carboxyl group include monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, or dicarboxylic acids. Furthermore, acid anhydride groups of dicarboxylic acids, monoalkyl esters and monoamides represented by the following general formulas can also be used.

[Formula] [In the formula, R ₁ is H or CH ₃ , R ₂ is a C ₂ to C ₆ alkylene group, and R ₃ is phenylene, cyclohexylene, a C ₂ to _{C 6} alkylene group, or a divalent unsaturated carbonized Represents a hydrogen group. ] Specific carboxyl group-containing vinyl monomers include:

[ka]

[ka]

【formula】

[Formula] There are also succinic acid mono-(meth)acrylooxyester, maleic acid mono-(meth)
Acrylooxyester, phthalic acid mono-(meth)
Acryloxy ester, hexahydrophthalic acid (meth)acryloxy ester, succinic acid mono-(meth)acryloxypropyl ester, maleic acid mono-(meth)acryloxypropyl ester, phthalic acid mono(meth)acrylic ester hexahydrophthalic acid mono-
Examples include (meth)acrylooxypropyl ester, adipic acid mono(meth)acrylooxyethyl ester, and malonic acid mono(meth)acrylooxyethyl ester. Among these carboxyl group-containing vinyl monomers, acrylic acid or methacrylic acid is preferably used. As the vinyl monomer containing an epoxy group, all compounds containing a vinyl group and an epoxy group in the molecule can be used. Preferred epoxy group-containing vinyl compounds have the general formula

[Formula] [In the formula, R represents a hydrogen atom, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group. ] Compounds and general formulas represented by

There is a compound represented by the following formula: [R in the formula is the same as the above formula]. Preferred specific compounds include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, and allyl glycidyl ether. Particularly preferred epoxy group-containing vinyl compounds include glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. be. These epoxy group-containing vinyl compounds may be used alone or in combination of two or more. Furthermore, as a vinyl monomer containing a hydroxy group, the general formula

[Formula] [In the formula, R ₁ represents hydrogen or a methyl group, and R ₂ represents hydrogen or an alkyl group having 1 to 6 carbon atoms. ] Examples include acrylic acid ester compounds represented by the following. Among these, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate are preferred. These monomers having a carboxyl group, epoxy group, or hydroxyl group are contained in the rubber polymer component in an amount of 0.01 to 15% by weight, preferably 0.1 to 10% by weight.
It is preferable that they are copolymerized at a ratio of . 0.01
If it is less than 15% by weight, the improvement effect is poor, and if it is less than 15% by weight.
Exceeding this is not preferable because the glass transition temperature of the copolymer will be high and the physical properties of the rubber will be poor. The rubber component (B) used in the present invention needs to contain a gel content of 20% or more. The gel content in rubber can be determined by dissolving a piece of rubber in a good solvent such as methyl ethyl ketone or toluene and measuring the content of insoluble matter. In detail, it can be measured by the method described in Example 1. The gel content in the rubber (B) is required to be 20% or more, preferably 50% or more, and more preferably 70% or more. If the gel content is less than 20%, the compression set of the thermoplastic elastomer of the present invention will be large, resulting in poor performance as an elastomer. The above-mentioned rubber containing a gel component can be produced by copolymerizing a crosslinkable monomer in the presence of a crosslinking monomer during production of the rubber. According to this method, it is possible to obtain rubber particles containing fine gel components, so that a composition of excellent quality can be stably produced. Examples of the crosslinkable monomer include at least one crosslinkable monomer selected from divinylbenzene, diallyl phthalate, diallyl fumarate, and trimethylolpropane triacrylate. The amount of the crosslinking monomer used is preferably 0.01
~20% by weight, more preferably 0.1~10% by weight. The thermoplastic elastomer composition of the present invention has the above-mentioned properties.
It is manufactured by mixing (A) a polyester elastomer and (B) a rubber component in a specific ratio. The rubber component (B) is preferably dispersed and mixed in the component (A), and its particle size is preferably 100,000 Å or less, more preferably 10,000 Å or less, particularly preferably 5,000 Å or less, especially 3,000 Å or less. The mixing ratio of each of the above components is 25 to 95% by weight, preferably 35 to 90% by weight of the (A) polyester elastomer component.
The rubber component (B) is 75 to 5% by weight, preferably 65 to 10% by weight. The rubber component (B) is 75
If it exceeds % by weight, the fluidity of the resulting composition decreases and processing becomes difficult. Moreover, if it is less than 5% by weight, the effect of improving the flexibility of the resulting composition will not be sufficiently recognized. In order to exhibit the effects of the invention in the thermoplastic elastomer composition of the invention, it is preferable to set the temperature during mixing to a temperature equal to or higher than the melting point of the polyester elastomer component (A). If the temperature of the polyester elastomer component during mixing is lower than the melting point, not only will the stirring torque during mixing become high, but also the mixing will be insufficient and the physical properties of the resulting composition will not be fully exhibited, which is undesirable. Furthermore, if the temperature during mixing is too high, the soft component of the rubber component (B) will deteriorate due to thermal decomposition, and a composition with high physical properties will not be obtained, which is not preferable. Therefore, the temperature during mixing is preferably 5°C or more, more preferably 10°C or more higher than the melting point of the polyether ester amide, preferably 300°C.
Below, the temperature is more preferably 280°C or below. In the production of the thermoplastic elastomer composition of the present invention, known devices such as open-type mixing rolls, closed-type Banbury mixers, extruders, kneaders, continuous mixers, etc. can be used for melt-mixing each component. I can do it. The thermoplastic elastomer composition of the present invention may contain fillers such as calcium carbonate, calcium silicate, etc., to the extent that fluidity and mechanical strength are not impaired.
Clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, carbon fiber, etc., or colorants such as carbon black. , ultramarine blue, titanium oxide, zinc white, red iron, dark blue, azo pigment, nitrone pigment,
Lake pigments, phthalocyanine pigments, etc. can be blended. In addition, mineral oil-based rubber softeners called process oils or extending oils, dioctyl phthalate, dibutyl phthalate, diethyl phthalate, dimethyl phthalate, dipeptyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, Phthalate esters such as diisononyl phthalate, dimethyl isophthalate, diundecyl phthalate, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, totimethyl phosphate, tributoxyethyl phosphate, Tris chloroethyl phosphate, tris dichloropropyl phosphate, condensed phosphate ester, triphenyl phosphate, tricylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2
- Phosphate esters such as ethylhexyldiphenyl phosphate, trilauryl phosphate, tricetyl phosphate, tristearyl phosphate, and trioleithorphate, trimellitate octyl ester, trimellitate isononyl ester, trimellitate isodecyl ester trimellitic acid esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl adipate, diisobutyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol adipate, di-2-ethylhexyl azelate, dioctyl aze fatty acid esters such as ester, dioctyl sebacate, di-2-ethylhexyl sebacate, methyl acetyl ricinoleate, pyromellitic acid esters such as pyromellitic acid octyl ester, epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid alkyl ester Plasticizers such as epoxy plasticizers such as (for example, epoxidized fatty acid octyl esters), polyether plasticizers such as adipic acid ether esters, polyether esters, and polyethers can be used alone or in combination. The plasticizer is used for the purpose of improving the fluidity and reducing the hardness of the composition of the present invention, and depending on the purpose of the plasticizer, it may be included selectively in the A component or the B component of the present invention, or Those included in both components can be selected as appropriate. When using the above plasticizer in the composition of the present invention,
From the viewpoint of bleeding properties, phthalate esters, phosphate esters, epoxy plasticizers, polyether plasticizers and the like are preferred, and phthalate esters and polyether plasticizers are more preferred. Phthalate esters are mainly effective in plasticizing the A component, and polyether plasticizers are mainly effective in plasticizing the B component. When using phthalate esters, use phthalate esters with a molecular weight of 300 or more to reduce the amount of volatile components during injection molding.
It is preferable to use 20% or more of the total amount of plasticizer used, preferably 400 or more. Among the polyether plasticizers, preferred are polyether ester plasticizers with a molecular weight of 400 or more. The above plasticizer is used in an amount of 1 to 200 parts by weight per 100 parts by weight of components A+B of the present invention. Furthermore, fluidity can be improved by blending liquid rubber such as liquid NBR, liquid acrylic rubber, and liquid polybutadiene rubber within a range that does not impair mechanical strength. Furthermore, during mixing, phenylenediamine-based antioxidants (Nokrac CD, Nokrac TD, Nokrac G1, Aspik, manufactured by Ouchi Shinko Chemical Co., Ltd.) and imidazole-based antioxidants (Nokrac MB, manufactured by Ouchi Shinko Chemical Co., Ltd.) are added. , Nokrac MMB), hindered phenolic antioxidants (BHT), and various UV absorbers can be added. Also, styrene-butadiene block polymer,
Aromatic vinyl-conjugated diene block copolymers such as styrene-butadiene-styrene block polymers and styrene-butadiene-styrene radial teleblock polymers, and hydrogenated products of the block copolymers, polypropylene, polyvinyl chloride,
Polycarbonate, PET, PBT, polyacetal, polyamide, epoxy resin, vinylidene fluoride, polysulfone, ethylene-vinyl acetate copolymer, PPS resin, polyetheretherketone,
PPO resin, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer, rubber-modified PPO resin, styrene-aleimide copolymer, rubber-modified styrene-maleimide copolymer,
It can be appropriately blended with elastomers other than polyester elastomers, such as resins such as polyamide elastomers, thermoplastic elastomers, and the like. Applications of the thermoplastic elastomer composition of the present invention include body panels, bumper parts, side shields, steering wheels, joint boots, strut suspension boots, moldings,
Automotive parts such as handles, footwear such as shoe soles and sandals, electrical parts such as wire coverings, connectors and cap plugs, golf club grips, baseball bat grips, car and motorcycle grips, swimming fins, underwater glasses, etc. Used as material for cashier supplies, gaskets, waterproof cloth, hydraulic holes, fuel hoses, Freon gas hoses, power steering hoses, coil tubes, packing, rolls, garden hoses, belt keyboards, curl cords, coupling rings, dust boots, O-rings, etc. It is possible to do so. e Examples Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. In addition, physical properties were measured by the following method. Example 1 Using the emulsion polymerization recipe shown below, it was produced by carrying out emulsion polymerization under the following polymerization conditions in an autoclave with an internal volume of 20. Emulsion polymerization recipe monomer Acrylonitrile 34 parts Butadiene 59 Methacrylic acid 6 Divinylbenzene 1 Water 220 Polyoxyethylene nonyl phenyl ether (“Emulgen” manufactured by Kao Soap Co., Ltd.) 5 Tertiary dodecyl mercaptan 0.2 Ammonium persulfate 0.25 Cyanoethylated diethanolamine 0.15 Total 325.6 After the polymerization conversion rate reaches 90%, monomer 100
The polymerization was stopped by adding 0.2 parts per part of hydroxylamine sulfate. After heating the obtained polymerization product and recovering the residual monomer by steam distillation at about 70°C under reduced pressure, 2 parts of alkylated phenol was added as an antiaging agent, and then the obtained polymer was collected in a pressure tube. Pour in the latex, heat it to 110℃ to solidify the latex, and then heat the coagulated material to 80℃.
It was vacuum dried at ℃ to obtain a crosslinked carboxy-modified NBR rubber. Crosslinked carboxy-modified NBR rubber obtained above
Shred 1g and add 100g of methyl ethyl ketone,
After standing at 25°C overnight, the gel was sedimented using a high-speed centrifuge, and the supernatant was filtered off. After adding methyl ethyl ketone to the obtained gel and stirring, centrifugation was performed, and the supernatant liquid was filtered and removed. Furthermore, the same operation was repeated twice. As a result, 0.835 g of gel-like rubber was obtained. Therefore,
The content of rubber containing gel in the crosslinked carboxy-modified NBR rubber was determined to be 83.5%. Polyetherester elastomer (Toyobo Co., Ltd.)
25 g of Pelprene P40H) obtained above and 25 g of the crosslinked carboxy-modified NBR rubber obtained above were kneaded using a Brabender at 180°C and 60 rpm for 5 minutes, and then immediately rolled into a 1 mm thick sheet using a take-out roll. Molded. Then, it was heated in a hot press at 190°C for 10 minutes, then transferred to a cold press at 30°C, and press-molded by applying a pressure of 100 kg/cm ² G while cooling. Obtained thickness: 1 mm, length: 11 cm, width: 9
A JIS No. 3 dumbbell-shaped test piece was punched out from a sheet of 5 cm in length according to the method of JIS K-6301, and a tensile test was conducted on this test piece according to the method of JIS K-6301. Hardness and compression set were also measured according to the method of JIS K-6301. The results are shown in Table-1. Examples 2 to 3 The amounts of Penprene P40H and crosslinked carboxy-modified NBR rubber of Example 1 were 35 g, 15 g, and 15 g, respectively.
A composition was prepared in the same manner as in Example 1 except that the amount was changed to 35 g, and its physical properties were measured. The results are shown in Table-1. Comparative Example 1 In the emulsion polymerization recipe of Example 1, the amount of divinylbenzene was varied, and the content of rubber containing gel content was changed.
A cross-linked carboxy-modified MBR rubber of 10% or less was obtained. After kneading and molding 25 g of this crosslinked carboxy-modified NBR rubber and 25 g of Penprene P40H in the same manner as in Example 1, the physical properties thereof were evaluated. The results are shown in Table-1. Example 4 Cross-linked carboxy-modified NBR prepared in Example 1
Instead of rubber, cross-linked NBR (manufactured by Japan Synthetic Rubber Co., Ltd.)
A composition was prepared using NBR N201S) and its physical properties were evaluated. The results are shown in Table-1. Example 5 Pelprene S2000 (manufactured by Toyobo Co., Ltd.), which is a polyether, was used instead of Pelprene P40H in Example 1.
A composition was prepared in the same manner as in Example 1, except that the kneading temperature was 220° C., and its physical properties were evaluated. The results are shown in Table-1. Comparative Example 2 Crosslinked carboxy-modified NBR obtained in Comparative Example 1
A composition was prepared by kneading 25 g of rubber and 25 g of Pelprene S200, and its physical properties were evaluated. Table the results.
Shown in 1. Example 6 Instead of the crosslinked carboxy modified NBR rubber used in Example 1, a crosslinked carboxy SBR rubber (77% rubber content including gel content) obtained by polymerization according to the following formulation was used. A composition was prepared in the same manner as in Example 1 except for the above, and its physical properties were evaluated. The results are shown in Table-1. Crosslinked carboxy SBR rubber formulation Styrene 23 parts Butadiene 76 parts Divinylbenzene 1 part Comparative Example 3 Crosslinked carboxy modified NBR obtained in Comparative Example 1
After kneading 25 g of rubber and 25 g of Pelprene P40H at 190℃ for 5 minutes using a Brabender, peroxide (Perhexa 25B manufactured by NOF Corporation) was added as a crosslinking agent.
-40) was added and kneaded for an additional 5 minutes to prepare a composition, and its physical properties were evaluated. Table the results.
Shown in 1. Further, its fluidity was measured using a Koka type flow tester. Measurements were carried out by increasing the temperature from 150°C to 250°C at a heating rate of 6°C/min, but no substantial flow phenomenon was observed and the composition deteriorated due to heat. Therefore, it was found that the thermoplastic elastomer composition of the present invention exhibits almost no fluidity. Comparative Example 4 Carboxy-modified NBR was prepared using the same recipe as Comparative Example 1 except that divinylbenzene was not added.
3 g of zinc oxide as a metal compound was added to 25 g of the obtained carboxy-modified NBR and 25 g of Penprene P40H according to the method described in JP-A-54-39457.
was added and kneaded using a Brabender in the same manner as in Example 1 to obtain a composition. The physical properties of the composition were evaluated. The results are shown in Table-1. Example 7 The monomer composition of Example 1 was changed to the following formulation,
A crosslinked epoxy modified rubber using glycidyl methacrylate instead of methacrylic acid was obtained. Monomer composition Acrylonitrile 34 parts Butadiene 59 Glycidyl methacrylate 6 Ethylene glycol dimethacrylate 1 Next, a composition was prepared in the same manner as in Example 1 according to the formulation shown in Table 1, and its physical properties were evaluated. The results are shown in Table-1. Examples 8 and 9 Cross-linked carboxy-modified polymers were produced in the same manner as in Example 1, except that the monomer composition in Example 1 was changed in the amounts of methacrylic acid and cross-linkable monomer used as shown below.
NBR was prepared and kneaded with polyester elastomer to obtain a composition. Evaluate its physical properties,
The results are shown in Table-1. Monomer composition Example 8 Example 9 Acrylonitrile 33 parts 34 parts Butadiene 56.5 59 Methacrylic acid 10 2 Divinylbenzene 0.5 5 Comparative example 5 The ratio of the polyester elastomer used in Example 1 and crosslinked carboxy-modified NBR was 90:10
I tried kneading it using a Brabender, but
Because the stirring torque for mixing was too high, kneading could not be performed. Next, both components were mixed using a 4-inch roll, and then formed into a sheet using a press, which was then subjected to a tensile test.
Both the tensile strength and tensile elongation were low, and were at a level that could not be used for practical purposes. In addition, molding by injection molding etc. is difficult, and from the viewpoint of processability and physical properties, if the content of cross-linked carboxy-modified NBR exceeds the content range shown in the claims of the present invention, the resulting composition will not be suitable for practical use. I found out that I couldn't stand it. Examples 10 to 15 Polymerization was carried out under the same conditions as in Example 1, except that the monomer composition was changed to the following, to obtain a rubber with a gel content of 88%. Monomer composition (parts) Acrylonitrile 26 Butadiene 52.5 N-butyl acrylate 14 Methacrylic acid 6 Divinylbenzene 1.5 Polyether ester (manufactured by Deutral)
PIBIFLEX 40M), the above rubber component and plasticizer were mixed in the proportions shown in Table 2 in the same manner as in Example 1, and evaluated. The evaluation results are shown in Table-2.

[Table] f Effects of the Invention The present invention improves flexibility, which has been a problem with conventional thermoplastic polyester elastomers, by blending a specific amount of a rubber component containing 20% by weight or more of crosslinked rubber into a polyester elastomer. It is possible to obtain a thermoplastic elastomer with improved compression set, excellent bending resistance and mechanical strength, and excellent properties as an industrial material. Furthermore, in the present invention, a rubber component with a small particle size can be obtained by crosslinking with a specific crosslinkable monomer. By dispersing and mixing this rubber component with a small particle size into the polyester elastomer component, a composition with excellent quality can be stably produced. Furthermore, by introducing a functional group such as a carboxyl group into the rubber component, a thermoplastic elastomer with even better mechanical strength can be obtained.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (A) 25 to 95% by weight of the polyester elastomer component, (B) at least one crosslinkable monomer selected from divinylbenzene, diallyl phthalate, diallyl fumarate, and trimethylolpropane triacrylate. Rubber component 75, which is a rubber cross-linked by polymer and contains 20% or more of gel content.
A thermoplastic elastomer composition obtained by dispersing and mixing ~5% by weight. 2 (B) The rubber component is diene rubber such as polyisoprene rubber, styrene-butadiene rubber, styrene-butadiene block copolymer rubber, polybutadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, acrylic rubber, fluorine rubber, etc. Claim 1 characterized in that the rubber is at least one type of rubber selected from non-diene rubbers or hydrogenated rubbers such as hydrogenated acrylonitrile-butadiene rubber and hydrogenated styrene-butadiene block copolymer rubber. The thermoplastic elastomer composition described in . 3 (B) The rubber component is a rubber containing at least one functional group selected from a carboxyl group, an epoxy group, an amino group, and a hydroxy group. The thermoplastic elastomer composition described. 4 (B) Claims 1 to 4, wherein the rubber component is a rubber obtained by copolymerizing 0.01 to 15% by weight of a monomer having at least one functional group selected from a carboxyl group, an epoxy group, and a hydroxy group. Thermoplastic elastomer composition according to any one of Item 3. 5. (B) The thermoplastic elastomer composition according to claim 1, wherein the rubber component has a dispersed particle size of 100,000 Å or less. 6. The thermoplastic elastomer composition according to claim 1, wherein the polyester elastomer component (A) is a block copolymer having a high melting point polymer segment and a low melting point polymer segment.