JP7271196B2 - Thermoplastic elastomer composition - Google Patents

Description

The present invention is a thermoplastic elastomer composition used for various molded articles used in automobiles, machinery, construction materials, clothing, electronic materials, food containers, home appliances, electrical equipment, medical tools, packaging materials, stationery and miscellaneous goods. product, a composite molded article and a doorstop packing using the thermoplastic elastomer composition.

BACKGROUND ART Conventionally, a thermoplastic elastomer composition containing a thermoplastic polyurethane has been proposed for a door stop packing used in construction materials such as housing materials. In addition, in molding, when co-extrusion molding with polar resins, especially acrylonitrile-butadiene-styrene resin (ABS resin), it is possible to heat-seal in the mold. There is a need for superior thermoplastic elastomer compositions.

For example, in Patent Document 1, by adding a softening agent, a polyester block copolymer, and a compatibilizer to a specific thermoplastic styrene elastomer, excellent flexibility and heat fusion with a polar resin can be obtained. It is disclosed that there are

JP 2018-70809 A

However, Patent Document 1 does not disclose co-extrusion molding with a polar resin such as ABS resin.

An object of the present invention is to provide a thermoplastic elastomer composition which is excellent in heat-sealability with polar resins and has fluidity suitable for co-extrusion molding, a composite molded article and a door using the thermoplastic elastomer composition. To provide a hit packing.

The present invention
[1] A thermoplastic styrene-based elastomer A, a softening agent B, a polyester block copolymer C1 and/or a polyurethane block copolymer C2, a compatibilizer D, and a thickener E, and a thermoplastic styrene-based The content of the softener B is 5 to 50 parts by mass, and the content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 is 50 to 250 parts by mass with respect to 100 parts by mass of the elastomer A. , a thermoplastic elastomer composition in which the content of the compatibilizer D is 5 to 30 parts by mass and the content of the thickener E is 5 to 30 parts by mass;
[2] The thermoplastic elastomer composition according to [1] above, wherein the thermoplastic elastomer composition has a melt viscosity of 1,200 to 2,200 Pa·S at 190°C and 180 (1/sec);
[3] The thermoplastic elastomer composition according to [1] or [2] above, wherein the thermoplastic elastomer composition has a melt mass flow rate of 3 g/10 min or less under conditions of 230°C and a nominal load of 5 kg.
[4] The thermoplastic elastomer composition according to any one of [1] to [3] above, wherein the thermoplastic elastomer composition has an A hardness of 30 to 80;
[5] The thermoplastic elastomer composition according to any one of [1] to [4] above, wherein the thermoplastic styrene elastomer A has a weight average molecular weight of 50,000 to 500,000.
[6] The thermoplastic elastomer composition according to any one of [1] to [5] above, wherein the thermoplastic styrene elastomer A contains a controlled distribution styrene block copolymer;
[7] The thermoplastic elastomer composition according to any one of [1] to [6] above, wherein the softener B contains at least one selected from paraffinic oils and naphthenic oils;
[8] The thermoplastic elastomer composition according to any one of [1] to [7] above, wherein the softener B has a kinematic viscosity of 30 to 500 mm ² /s at 40°C.
[9] Any one of [1] to [8] above, wherein the polyester-based block copolymer C1 has a hard segment and a soft segment at a mass ratio (hard segment/soft segment) of 10/90 to 30/70. a thermoplastic elastomer composition of
[10] The thermoplastic elastomer composition according to any one of [1] to [9] above, wherein the compatibilizer D contains a maleic acid-modified hydrogenated thermoplastic styrene elastomer.
[11] The above [1] to [10], wherein the thickener E contains at least one selected from the group consisting of epoxy compounds, polycarbodiimide compounds, ionomers, and (meth)acrylic acid alkyl ester polymers. The thermoplastic elastomer composition according to any one,
[12] The thermoplastic elastomer composition according to any one of [1] to [11] above, which is a thermoplastic elastomer composition for coextrusion molding with a polar resin;
[13] A composite molded article obtained by heat-sealing the thermoplastic elastomer composition according to any one of [1] to [11] and a polar resin,
[14] The molded composite according to [13] above, wherein the polar resin is an acrylonitrile-butadiene-styrene resin.
[15] The molded composite according to [13] or [14] above, which is a coextrusion molding of a thermoplastic elastomer composition and a polar resin;
[16] A doorstop packing, which is a composite molded article obtained by heat-sealing the thermoplastic elastomer composition according to any one of the above [1] to [11] and an acrylonitrile-butadiene-styrene resin, and [17] a composite molded article. is a co-extruded product of a thermoplastic elastomer composition and an acrylonitrile-butadiene-styrene resin.

The thermoplastic elastomer composition of the present invention is excellent in thermal fusion bondability and fluidity with a polar resin, and can be formed into a composite molded article suitable for use as a door stop packing by co-extrusion molding with a polar resin. be.

FIG. 2 is a cross-sectional view of a molded body molded by a main extruder in coextrusion molding in Examples. FIG. 2 is a cross-sectional view of a molded body molded by a sub extruder in coextrusion molding in Examples. FIG. 2 is a cross-sectional view of a door stop packing obtained by co-extrusion molding in an example.

The thermoplastic elastomer composition of the present invention comprises a thermoplastic styrene elastomer A, a softener B, a polyester block copolymer C1 and/or a polyurethane block copolymer C2, a compatibilizer D and a thickener E. One feature is that it contains a thickener E. Since the thickener usually lowers the fluidity of the resin, it works disadvantageously in fusion with a polar resin by injection molding. However, in co-extrusion molding, the blending of a thickener exerts a pressure on the fusion bonding interface, resulting in an unexpected effect of improving the thermal fusion bondability with the polar resin.

From the viewpoint of flexibility and moldability, the thermoplastic styrene elastomer A in the present invention preferably comprises a hard portion (hard segment) and a soft portion (soft segment). It is more preferable that the block copolymer (Z1) has a block unit (s1) of a polymer composed of a solid and a block unit (b1) of a polymer composed of a conjugated diene compound as a soft segment.

Styrenic monomers constituting the block unit (s1) include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, Examples include vinylanthracene.

The content of the block unit (s1) in the block copolymer (Z1) is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, from the viewpoint of flexibility and thermal adhesion to the polar resin. be.

Conjugated diene compounds constituting the block unit (b1) include butadiene, isoprene, 1,3-pentadiene and the like.

Hydrogenation of the block copolymer (Z1) reduces unsaturated bonds and improves heat resistance, weather resistance, and mechanical properties. . The hydrogenation rate is preferably 80% or more, more preferably 90% or more. In the present invention, the hydrogenation rate is obtained by measuring the content of carbon-carbon double bonds derived from the conjugated diene compound in the block copolymer by ¹ H-NMR spectrum before and after hydrogenation, and obtaining the measured value. can be obtained from

Specific examples of the hydrogenated block copolymer (Z1) include styrene-ethylene/butylene block copolymer, styrene-ethylene/butylene-styrene block copolymer (SEBS), and styrene-ethylene/propylene block copolymer. coalescence, styrene-ethylene/propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene/propylene block copolymer, styrene-(ethylene-ethylene/propylene)-styrene block copolymer (SEEPS), styrene- Isobutylene block copolymer, styrene-isobutylene-styrene block copolymer, (α-methylstyrene)-ethylene/butylene block copolymer, (α-methylstyrene)-ethylene/butylene-(α-methylstyrene) block copolymer A polymer etc. are mentioned. These may be used alone or as a mixture of two or more. SEBS, SEPS, and SEEPS are preferred, and SEBS is more preferred, from the viewpoint of raw material preparation and workability.

In the present invention, from the viewpoint of heat resistance, the thermoplastic styrene elastomer A has a [block unit (s1) - block unit ( Triblock copolymers of the b1)-block unit (s1)] type are preferred. Among the above hydrogenated products, triblock copolymers include SEBS, SEPS, SEEPS, SEB(S)S, styrene-isobutylene-styrene block copolymers, (α-methylstyrene)-ethylene-butylene-( α-methylstyrene) block copolymers, and the like.

The content of the triblock copolymer in the styrenic block copolymer A is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more.

The thermoplastic styrene-based elastomer A is preferably not acid-modified from the viewpoint that elastomers with various properties are industrially produced in large quantities and readily available.

The thermoplastic styrene elastomer A may be a controlled distribution styrene block copolymer. As a controlled distribution styrene block copolymer, instead of the block unit (b1), it is a copolymer unit of a conjugated diene and a styrene monomer, and has a block unit (b1') having a controlled distribution structure. things are preferred.

The block unit (b1') has two or more regions containing a conjugated diene unit as a main structural unit and one or more regions containing a styrene-based monomer unit as a main structural unit, and the block unit (s1) Both ends adjacent to are preferably regions containing conjugated diene units as main structural units.

The content of the styrenic monomer unit in the controlled distribution styrenic block copolymer A is preferably 45 to 80% by mass, more preferably 50 to 75% by mass, from the viewpoint of thermal adhesion to the polar resin. , more preferably 55 to 70% by mass. The content of the styrene monomer units in the controlled distribution styrene block copolymer A is the total amount of the styrene monomer units in the hard segment and the styrene monomer units in the soft segment.

The controlled-distribution styrene-based elastomer block copolymer is well known in the art, and is described, for example, in JP-A-2007-84821 and JP-A-2013-518170.

The weight-average molecular weight of the thermoplastic styrene elastomer A is preferably 50,000 or more, more preferably 100,000 or more, still more preferably 200,000 or more, from the viewpoint of oil bleeding resistance, heat resistance and mechanical properties. From the viewpoint of moldability during production, it is preferably 500,000 or less, more preferably 400,000 or less, and even more preferably 300,000 or less. When the thermoplastic styrene-based elastomer A is composed of a plurality of elastomers, it is preferable that the weighted average value of the weight average molecular weight of each elastomer falls within the above range.

The content of the thermoplastic styrene elastomer A in the thermoplastic elastomer composition is preferably 20-60% by mass, more preferably 35-50% by mass.

The thermoplastic styrene-based elastomer A may consist of one type, or two or more types may be used in combination. The same applies to block copolymer C2, compatibilizer D, and thickener E.

Examples of the softener B include rubber softeners such as paraffinic oils, naphthenic oils, and aromatic oils. At least one selected from paraffinic oils and naphthenic oils is preferable, and paraffinic oils are more preferable, from the viewpoint of preventing occurrence of the occurrence.

The higher the kinematic viscosity ^of the softener B at 40 ° C., the better the volatilization during heating and melting and the better ^the bleeding resistance. It is preferably 80 mm ² /s or more, ^and the lower the value, ^the easier it is ^to handle. It is 300 mm ² /s or less, more preferably 200 mm ² /s or less.

The content of the softening agent B is 5 parts by mass or more, preferably 10 parts by mass or more, relative to 100 parts by mass of the thermoplastic styrene elastomer A, from the viewpoint of flexibility. From the viewpoint of fusion bondability, it is 50 parts by mass or less, preferably 30 parts by mass or less.

The content of the softener B in the thermoplastic elastomer composition is preferably 3-20% by mass, more preferably 5-15% by mass.

The polyester-based block copolymer C1 preferably contains a hard segment and a soft segment, and has an aromatic polyester block as the hard segment and an aliphatic polyether block as the soft segment. Polyester-polyether block copolymer is more preferred.

The aromatic polyester block, which is the hard segment, includes phthalic acid, terephthalic acid, isophthalic acid, 1,4- or 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, One or more aromatic dicarboxylic acids such as 4,4'-diphenylsulfonedicarboxylic acid or alkyl esters thereof, and ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, 1,4- Polycondensation with one or more diols such as cyclohexanediol, 1,4-cyclohexanedimethanol, 4,4'-dihydroxydibiphenyl, and 2,2-bis(4'-β-hydroxyethoxydiphenyl)propane A body is preferred.

The soft segment, the aliphatic polyether block, preferably consists primarily of polyalkylene ether glycol. The weight average molecular weight of the aliphatic polyether block is preferably 400-60,000. The weight-average molecular weight of the aliphatic polyether block is obtained by measuring the molecular weight in terms of polystyrene by gel permeation chromatography in the same manner as the thermoplastic styrene-based elastomer A, to determine the weight-average molecular weight.

The polyester-based block copolymer C1 having more soft segments is advantageous in terms of heat fusion with the polar resin, but from the viewpoint of abrasion resistance, it is preferable that it has more hard segments. From this point of view, the mass ratio of the hard segment to the soft segment (hard segment/soft segment) in the polyester block copolymer C1 is preferably 10/90 to 30/70, more preferably 13/87 to 28/72. , more preferably 15/85 to 25/75.

The A hardness of the polyester block copolymer C1 is preferably 60-95, more preferably 65-90.

The melting point of the polyester block copolymer C1 is preferably 150-210°C, more preferably 160-190°C.

As the polyurethane-based block copolymer C2, a polyurethane-based block copolymer having a polyurethane block that is a condensate of a diisocyanate compound and a short-chain glycol as a hard segment and a polyester block or a polyether block as a soft segment is preferable. .

Diisocyanate compounds include phenylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and the like.

Examples of short-chain glycols include alkylene glycols having 2 to 5 carbon atoms such as ethylene glycol, propylene glycol and 1,4-butanediol.

Polyester blocks include polyalkylene adipates, polycaprolactones, polycarbonates, and the like.

Polyether blocks include poly( alkylene oxide) glycol and the like.

The polyester block and polyether block may contain condensation bonds with the diisocyanate compound.

The A hardness of the polyurethane-based block copolymer C2 is preferably 60-95, more preferably 65-90.

The content of the polyester-based block copolymer C1 and/or the polyurethane-based block copolymer C2 is such that when the polyester-based block copolymer (C1) and the polyurethane-based block copolymer (C2) exceed a certain amount, it becomes a polar resin. The heat-sealing property of is deteriorated. From this point of view, the content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 is 50 to 250 parts by mass, preferably 70 parts by mass, per 100 parts by mass of the thermoplastic styrene elastomer A. ~200 parts by mass, more preferably 70 to 150 parts by mass. In this specification, the content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 refers to the content of the polyester block copolymer C1 when each is contained alone. When the content or the content of the polyurethane-based block copolymer C2 is used in combination, it means the total content of both.

The content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 in the thermoplastic elastomer composition is preferably 25-60% by mass, more preferably 35-50% by mass.

As the compatibilizer D, acid-modified hydrogenated thermoplastic styrene-based elastomer D1, acid-modified olefin-based thermoplastic elastomer D2, and styrene-based elastomer and urethane At least one elastomer selected from the group consisting of graft polymer D3 of system elastomers is preferred. Among these, the acid-modified hydrogenated thermoplastic styrene-based elastomer D1 is more preferable from the viewpoint of heat-sealability with the polar resin.

The acid-modified hydrogenated thermoplastic styrene elastomer D1 comprises block units (s2) of a polymer comprising a styrene monomer as a hard segment and block units (b2) of a polymer comprising a conjugated diene compound as a soft segment. A hydrogenated product of the block copolymer (Z2) having is preferably acid-modified.

Styrenic monomers constituting the block unit (s2) include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, Examples include vinylanthracene.

Conjugated diene compounds constituting the block unit (b2) include butadiene, isoprene, 1,3-pentadiene and the like.

The content of the block unit (s2) in the block copolymer (Z2) is preferably 5-70% by mass, more preferably 10-60% by mass, still more preferably 20-50% by mass.

Hydrogenation of the block copolymer (Z2) may be partially or wholly, but the hydrogenation reduces unsaturated bonds, resulting in heat resistance, weather resistance and mechanical properties. be done. From these points of view, the hydrogenation rate is preferably 80% or more, more preferably 90% or more.

Specific examples of the hydrogenated block copolymer (Z2) include styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-ethylene-propylene-styrene Block copolymer, styrene-ethylene-butylene (styrene controlled distribution)-styrene block copolymer, styrene-isobutylene-styrene block copolymer, styrene-butadiene rubber, acrylonitrile-butadiene rubber, pyridine-butadiene rubber, styrene-isoprene Rubber, styrene-ethylene copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene), poly(α -methylstyrene)-polyisoprene-poly(α-methylstyrene), ethylene-propylene copolymer, styrene-chloroprene rubber and the like. These may be used alone or in a mixture of two or more. - styrene block copolymers (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymers (SEEPS), styrene-ethylene-butylene (styrene controlled distribution) - styrene block copolymers (SEB(S)S) and styrene-isobutylene-styrene block copolymer (SIBS).

Acid modification of the hydrogenated product of the block copolymer (Z2) is not particularly limited, but can be carried out, for example, by introducing a carboxyl group or an acid anhydride group into the hydrogenated product. Introduction of the above carboxyl group or acid anhydride group can be carried out according to a method known per se. Specifically, for example, a hydrogenated product, an unsaturated monocarboxylic acid exemplified by acrylic acid, methacrylic acid, etc.; an unsaturated dicarboxylic acid exemplified by maleic acid, fumaric acid, hymic acid, itaconic acid, etc.; Anhydrides of unsaturated dicarboxylic acids exemplified by maleic acid, hymic anhydride, and itaconic anhydride are heated in the presence or absence of a solvent in the presence of an organic peroxide to cause a graft reaction. can be obtained by It is also commercially available.

In the present invention, the acid-modified hydrogenated thermoplastic styrene elastomer D1 is preferably a maleic acid-modified hydrogenated thermoplastic styrene elastomer from the viewpoint of fusion bondability.

The acid modification amount of the acid-modified hydrogenated thermoplastic styrene elastomer D1 is preferably 0.5 to 5% by mass, more preferably 0.7 to 4.0% by mass, and even more preferably 1.0 to 3.0% by mass, from the viewpoint of compatibility and workability. .

The content of the compatibilizer D is 5 to 30 parts by mass, preferably 7 to 25 parts by mass, with respect to 100 parts by mass of the thermoplastic polystyrene elastomer A, from the viewpoint of improving heat-sealability to other materials. part by mass.

Also, the content of the compatibilizer D in the thermoplastic elastomer composition is preferably 2 to 11% by mass, more preferably 4 to 9% by mass.

The thickener E is preferably at least one selected from the group consisting of epoxy compound E1, polycarbodiimide compound E2, ionomer E3, and (meth)acrylic acid alkyl ester polymer E4.

As the epoxy compound E1, a copolymer of an ethylene-based monomer and/or a styrene-based monomer and an epoxy group-containing olefin-based monomer is preferable.

Ethylene-based monomers include ethylene, propylene, butene, vinyl acetate, (meth)acrylic acid, and the like.

Styrene etc. are mentioned as a styrene-type monomer.

Glycidyl (meth)acrylate is preferred as the epoxy group-containing olefinic monomer. Glycidyl (meth)acrylate has very high reactivity with the terminal functional groups of polyester block copolymer C1 and polyurethane block copolymer C2, and a copolymer containing glycidyl (meth)acrylate is blended. As a result, the viscosity of the polyester block copolymer phase is increased, and during kneading, the viscosity ratio between the polyester block copolymer phase and the thermoplastic styrene elastomer phase shrinks, and the two phases are dispersed more finely. It is possible to improve mechanical strength such as abrasion resistance. From these viewpoints, the content of glycidyl (meth)acrylate is preferably 5 to 70% by mass, more preferably 5 to 50% by mass, still more preferably 10 to 30% by mass, more preferably 10 to 30% by mass, in the monomer units. is 10 to 20% by mass. In the present invention, the content in a monomer unit means the content of the unit in all monomer units constituting the copolymer.

Specific examples of the epoxy compound E1 include ethylene-glycidyl (meth)acrylate copolymer, ethylene-propylene-glycidyl (meth)acrylate copolymer, and ethylene-butene-1-(meth)glycidyl acrylate copolymer. , ethylene-vinyl acetate-glycidyl (meth)acrylate copolymer, ethylene-glycidyl methacrylate copolymer such as ethylene-acrylic acid-glycidyl (meth)acrylate copolymer; styrene-glycidyl (meth)acrylate copolymer; coalescence, styrene-propylene-glycidyl (meth)acrylate copolymer, styrene-butene-1-(meth)glycidyl acrylate copolymer, styrene-vinyl acetate-glycidyl (meth)acrylate copolymer, styrene-acrylic Styrene-glycidyl methacrylate copolymers such as acid-glycidyl (meth)acrylate copolymers and the like are included.

The weight-average molecular weight of the epoxy compound E1 is preferably 5,000 or more, more preferably 6,000 or more, still more preferably 7,000 or more, and still more preferably 20,000 or more, because volatilization at high temperatures can be suppressed as the weight average molecular weight of the epoxy compound E1 increases. Also, since the smaller the number, the higher the reactivity, it is preferably 300,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less.

The polycarbodiimide compound E2 includes an aliphatic polycarbodiimide in which R is an aliphatic group and an aromatic polycarbodiimide in which R is a group having an aromatic group. Also, the aliphatic group is preferably linear rather than branched.

Polycarbodiimide compound E2, for example, using monoisocyanate or polyisocyanate as a raw material, in the presence of an organophosphorus compound or an organometallic compound, at a temperature of about 70 ° C. or higher, in the absence of a solvent or an inert solvent undergoes a decarboxylation condensation reaction. obtained by doing

The weight average molecular weight of the polycarbodiimide compound E2 is preferably 1,000 to 10,000, more preferably 2,000 to 9,000 from the viewpoint of ease of handling.

Ionomer E3 has a structure in which carboxyl groups are partially or completely neutralized with a metal salt in a copolymer of an ethylene monomer and an unsaturated carboxylic acid such as (meth)acrylic acid, Furthermore, it preferably has a structure in which molecular chains are crosslinked via a metal salt. Ionomers are usually used as additives for improving the transparency of thermoplastic elastomers. It is added as a thickening agent.

Ethylene-based monomers include ethylene, propylene, butene, vinyl acetate and the like, and among these, ethylene is preferred.

Examples of metal salts include monovalent metal salts such as sodium ion and potassium ion; divalent metal salts such as magnesium ion, calcium ion and zinc salt; and trivalent metal salts such as aluminum ion. Among them, sodium salts are preferred.

The melting point of ionomer E3 is preferably 50 to 150°C, more preferably 70 to 130°C, from the viewpoint of kneadability.

The melt mass flow rate (MFR) of ionomer E3 is preferably 0.05-100 g/10 min, more preferably 0.5-10 g/10 min at 190° C. and a nominal load of 2.16 kg.

The (meth)acrylic acid alkyl ester polymer E4 is a homopolymer or copolymer containing a (meth)acrylic acid alkyl ester as a monomer unit, and improves moldability by improving the fluidity of the resin. Improve.

(Meth)acrylic acid alkyl esters include n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, Examples include isobornyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, benzyl (meth)acrylate and the like.

Examples of monomer units other than (meth)acrylic acid alkyl esters include aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, and t-butylstyrene. monomer units derived from vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; monomers derived from glycidyl group-containing monomers such as glycidyl (meth)acrylate Body units; monomer units derived from vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate; monomer units derived from olefin monomers such as ethylene, propylene and isobutylene; butadiene and isoprene monomer units derived from diene-based monomers such as maleic acid and maleic anhydride; and monomer units derived from unsaturated carboxylic acid monomers such as maleic acid and maleic anhydride.

The weight average molecular weight of the (meth)acrylic acid alkyl ester polymer E4 is preferably from 500,000 to 6,000,000, more preferably from 1,000,000 to 5,000,000, and still more preferably from 3,500,000 to 5,000,000, from the viewpoint of improving fluidity and improving compatibility. be.

From the viewpoint of fluidity, the content of the thickener E is 5 to 30 parts by mass, preferably 7 to 25 parts by mass, more preferably 10 to 20 parts by mass, relative to 100 parts by mass of the thermoplastic styrene elastomer A. part by mass.

Also, the content of the thickener E in the thermoplastic elastomer composition is preferably 2 to 11% by mass, more preferably 5 to 8% by mass.

The thermoplastic elastomer composition of the present invention may optionally contain reinforcing agents such as carbon black, silica, carbon fibers and glass fibers, inorganic fillers, and insulating thermally conductive fillers, as long as the effects of the present invention are not impaired. , pigments, hydrated metal compounds, red phosphorus, ammonium polyphosphate, antimony, flame retardants such as silicone, antistatic agents, thickeners, tackifiers, cross-linking agents, cross-linking aids, heat stabilizers, antioxidants, Various additives such as a light stabilizer, an ultraviolet absorber, an antiblocking agent, a sealability improver, a release agent, a coloring agent, and a perfume may be contained.

The thermoplastic elastomer composition of the present invention comprises a thermoplastic styrene elastomer A, a softening agent B, a polyester block copolymer C1 and/or a polyurethane block copolymer C2, a compatibilizer D, and a thickener. It can be obtained by appropriately mixing agent E with additives such as an antioxidant and solidifying by cooling.

The term “mixing” as used in the present invention is not particularly limited as long as it is a method in which various raw materials are well mixed. Although they may be mixed, the mixing of raw materials is preferably carried out under conditions in which each raw material is melted.

The conditions under which the raw materials of the thermoplastic elastomer composition are melted can be defined, for example, based on the melting point of the polyester block copolymer C1 or the polyurethane block copolymer C2. The polyester-based block copolymer C1 and the polyurethane-based block copolymer C2 melt at a temperature higher than the melting point in a stationary state, but in the melt-kneading method, they melt at a temperature lower than the melting point measured in a stationary state. The higher the temperature, the lower the melt viscosity and the easier it is to mix. However, if the temperature is too high, thermal decomposition may occur. From these points of view, the preferred melting temperature range when kneading is -30°C to +100°C with respect to the melting point of the polyester block copolymer C1 or the polyurethane block copolymer C2, more preferably the melting point -20°C to +50°C.

When melt-kneading, a general extruder can be used, and a twin-screw extruder is preferably used to improve the kneading state. For feeding to the extruder, various components may be mixed in advance using a mixing device such as a Henschel mixer and supplied from one hopper, or each component may be charged into two hoppers and quantified with a screw or the like under the hopper. You can serve it while

The product obtained by mixing the raw materials constituting the thermoplastic elastomer composition can be in the form of pellets, powder, sheet, etc., depending on the application. For example, it is melted and kneaded by an extruder, extruded into a strand, cooled in cold water, and cut into cylindrical or rice grain-shaped pellets by a cutter. The obtained pellets are usually formed into desired sheet-like molded articles or die-molded articles by injection molding or extrusion molding. Also, the melt-kneaded product can be pelletized by a ruder or the like to be used as a molding raw material.

The A hardness of the thermoplastic elastomer composition is preferably 80 or less, more preferably 75 or less, from the viewpoint of flexibility. Also, it is preferably 30 or more, more preferably 60 or more.

The melt viscosity of the thermoplastic elastomer composition at 190°C and 180 (1/sec) is preferably 1,200 Pa S or higher, more preferably 1,400 Pa S or higher, and still more preferably 1,400 Pa S or higher, from the viewpoint of drawdown property. It is 1,600 Pa·S or more, and from the viewpoint of fluidity, it is preferably 2,200 Pa·S or less, more preferably 2,150 Pa·S or less, and still more preferably 2,100 Pa·S or less.

The melt mass flow rate (MFR) of the thermoplastic elastomer composition under conditions of 230° C. and a nominal load of 5 kg is preferably 3 g/10 min or less, more preferably 2 g/10 min or less, still more preferably 1 g/10 min or less.

The thermoplastic elastomer composition of the present invention is appropriately heat-molded according to a conventional method to obtain a molded article. Applications of molded articles obtained by thermoforming the thermoplastic elastomer composition of the present invention are not particularly limited, and general styrene-based elastomers, polyolefin-based elastomers, polyurethane-based elastomers, polyamide-based elastomers and acrylic-based elastomers are used. It can be used in fields where polyester-based elastomers and the like are used.

Any molding machine capable of melting a molding material can be used as an apparatus for producing a molded article using the thermoplastic elastomer composition of the present invention. Examples include kneaders, extrusion molding machines, injection molding machines, press molding machines, blow molding machines, mixing rolls and the like.

Since the thermoplastic elastomer composition of the present invention is heat-sealable to various materials, it can be suitably used for laminating members made of different materials. For example, it is used for heat-sealing to at least one member selected from the group consisting of metals, ceramics, glass and polar resins, and exhibits particularly good heat-sealing properties to polar resins.

The metal is not particularly limited, and examples thereof include aluminum, aluminum alloys, stainless steel, iron, copper, galvanized steel, magnesium, magnesium alloys, and various plated products.

Polar resins include, for example, polystyrene resins such as ABS resins, polyester resins, polycarbonates, poly(meth)acrylate resins such as polymethyl methacrylate, polyethylene oxide resins, polypropylene oxide resins, polyvinyl acetate resins, Polyamide resin, polyurethane resin, polyvinyl ether resin, polyvinyl alcohol resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyetherimide resin, polyetherketone resin, polyetheretherketone resin, LCP (liquid crystal polymer) ), polar resins such as ionomers, mixtures of two or more of these, and the like. Among these, it is particularly excellent in heat-sealability to ABS resin.

In the present invention, the heat-sealing is performed by applying heat above the melting point of the thermoplastic elastomer composition of the present invention to melt it, and then solidifying it at a temperature below the melting point, thereby fixing it to the interface of the object to be fused. It refers to the phenomenon of For applying heat, an extruder, an injection molding machine, a heat press, a heating roll machine, a hot air generator, heating steam, an ultrasonic welder, a high frequency welder, a laser, or the like can be used. Therefore, even if the interface of the fused portion has a complicated three-dimensional shape, the complicated three-dimensional shape can be satisfactorily molded and integrated.

A composite molded article in which the thermoplastic elastomer composition of the present invention is heat-sealed to a member can be molded by injection molding, injection compression molding, insert molding, multicolor molding, vacuum molding, air pressure molding, blow molding, hot press molding, foam molding, It can be obtained by molding by a method such as laser fusion molding or co-extrusion molding.

Composite molded articles in which the thermoplastic elastomer composition of the present invention is heat-sealed to a member include an insert molded article in which a polar resin is inserted into a molded article made of a thermoplastic elastomer composition, and a thermoplastic elastomer composition and a polar resin. and a composite molded article obtained by multi-color molding.

The thermoplastic elastomer composition of the present invention can be used as various molded articles depending on the application. Preferably, the thermoplastic elastomer composition and the polar resin are heat-sealed to form a composite molded article. As described above, the thermoplastic elastomer composition of the present invention can be suitably used as a thermoplastic elastomer composition for co-extrusion molding with a polar resin, and the composite molded article is a thermoplastic elastomer composition molded by co-extrusion molding. It is preferably a co-extruded product of the material and the polar resin. In co-extrusion molding, a thermoplastic elastomer composition and a polar resin are simultaneously extruded from separate extruders into a single mold to form a composite molded article in which the thermoplastic elastomer composition and the polar resin are heat-sealed. can get.

In addition, since the thermoplastic elastomer composition of the present invention is particularly excellent in heat-sealing properties with ABS resins, the present invention further provides heat-sealing properties between the thermoplastic elastomer composition of the present invention and ABS resins. Provided is a door stop packing which is a composite molded body. In general, a member that stops the door when it hits is called a "door stop". The part of the door stop that touches the door is a rubber packing, which has the effect of softening the impact and sound when the door hits, and this is called "door stop packing".

The door stop packing of the present invention is preferably a co-extruded product of the thermoplastic elastomer composition of the present invention and an ABS resin, like the composite molded product.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. Various physical properties of raw materials used in Examples and Comparative Examples were measured by the following methods.

<Component A: Thermoplastic styrene elastomer>
[Content of styrene-based monomer units]
The content of styrene and/or styrene derivatives is determined by performing proton NMR measurement with a nuclear magnetic resonance apparatus (DPX-400, manufactured by BRUKER, Germany) and quantifying the characteristic groups of styrene. The content of other monomeric units can also be determined by proton NMR measurement.

[Weight average molecular weight (Mw)]
Under the following measurement conditions, a gel permeation chromatograph is used to measure the molecular weight in terms of polystyrene to determine the weight average molecular weight.

Measuring device/pump: PU-980 manufactured by JASCO (JASCO Corporation)
・Column oven: AO-50, manufactured by Showa Denko K.K.
・Detector: Hitachi RI (differential refractometer) detector L-3300
・Column type: Showa Denko K-805L (8.0 x 300 mm) and K-804L (8.0 x 300 mm) are used in series ・Column temperature: 40℃
・Guard column: KG (4.6×10mm)
・Eluent: chloroform ・Eluent flow rate: 1.0ml/min
・Sample concentration: about 1mg/ml
・Sample solution filtration: Polytetrafluoroethylene 0.45 μm pore size disposable filter ・Standard sample for calibration curve: Showa Denko polystyrene

<Component B: Softener>
[Kinematic viscosity]
Measured at a temperature of 40°C according to JIS Z 8803.

<Component C: Polyester Block Copolymer and Polyurethane Block Copolymer>
[Hard Segment (HS) / Soft Segment (SS)]
The mass ratio (HS/SS) of the hard segment and the soft segment was determined using a nuclear magnetic resonance spectrometer (DPX-400, manufactured by BRUKER, Germany) in a deuterated chloroform solvent at a concentration of 3 to 5 vol% at 25°C by proton NMR. It is calculated from the signal intensity ratio of methylene peaks adjacent to various oxygens in the molecular structure.

[A hardness]
Leave the pressed sheet in a constant temperature and humidity room (temperature 23°C, relative humidity 50%) for 24 hours or more to stabilize the state of the sheet. Three press sheets with a thickness of 2 mm are piled up, and the A hardness is measured according to JIS K7215 "Durometer hardness test method for plastics".

[Melting point]
Using a differential scanning calorimeter (DSC) device, the temperature of the melting peak obtained by heating at 10°C/min according to the method specified in JIS K 7121 is defined as the melting point. When multiple melting peaks appear, the melting peak appearing at a lower temperature is taken as the melting point.

<Component D: compatibilizer>
[Content of styrene monomer]
It is measured using a nuclear magnetic resonance apparatus (DPX-400, manufactured by BRUKER, Germany).

[Amount of acid modification]
A blend of the base material and organic acid before modification is pressed using a 0.1 ^mm spacer, and IR is measured. is prepared, and the press plate of the acid-modified body is subjected to IR measurement (IR measurement device: FT-210 manufactured by Horiba, Ltd.) to determine the amount of modification.

<Component E: Thickener>
[Weight average molecular weight (Mw)]
Similarly to the thermoplastic styrene elastomer A, the molecular weight is measured in terms of polystyrene by gel permeation chromatography to determine the weight average molecular weight.

[Melting point]
Using a differential scanning calorimetry (DSC) device, the temperature of the melting peak obtained by heating at 10°C/min according to the method specified in JIS K 7121 is defined as the melting point. When multiple melting peaks appear, the melting peak appearing at a lower temperature is taken as the melting point.

[Carboxyl Group Concentration]
A blend of base material and organic acid before modification is pressed using a 0.1 mm spacer, IR is measured, and calibration is performed based on the amount of characteristic carbonyl absorption (1600-1900 cm ^-1 ) and the amount of organic acid charged. A line is drawn, and IR is performed on the press plate of the acid-denatured product (IR measurement device: FT-210 manufactured by Horiba, Ltd.) to calculate the concentration.

[Melt mass flow rate (MFR)]
Measured under conditions of 190°C and nominal load of 2.16 kg according to ASTM D1238.

[Content of glycidyl (meth)acrylate (GMA)]
When the epoxy compound does not contain a compound having an epoxy group other than GMA, the content of GMA is calculated from the concentration of the epoxy group measured by the method specified in JIS K 7236 in the same manner as the epoxy value. If a compound with an epoxy group is included in addition to GMA, a proton NMR measurement is performed using a nuclear magnetic resonance device (DPX-400, manufactured by BRUKER, Germany) to quantify the characteristic group of GMA. Determine quantity.

Examples 1 to 13 and Comparative Examples 1 to 9 (Example 5 is a reference example)
(1) Preparation of Thermoplastic Elastomer Composition (Pellets) Raw materials shown in Tables 7 to 9 other than the softening agent were dry-blended, and then impregnated with the softening agent to prepare a mixture. Thereafter, the mixture is melt-kneaded in an extruder under the following conditions, extruded into strands, cooled in cold water and cut into pieces of about 3 mm in diameter and about 3 mm in thickness with a cutter to obtain pellets of the thermoplastic elastomer composition. manufactured.

[Melt-kneading conditions]
Extruder: KZW32TW-60MG-NH (trade name, manufactured by Technobell Co., Ltd.)
Cylinder temperature: 180-220℃
Screw speed: 300r/min

Details of the raw materials listed in Tables 7 to 9 used in Examples and Comparative Examples are as follows.

(2) Preparation of molded body of thermoplastic elastomer composition Pellets were injection molded under the following conditions to prepare a plate of 2 mm thick×125 mm wide×125 mm long.

[Injection molding conditions]
Injection molding machine: 100MSIII-10E (trade name, manufactured by Mitsubishi Heavy Industries, Ltd.)
Injection molding temperature: 200℃
Injection pressure: 30%
Injection time: 3sec
Mold temperature: 40℃

The thermoplastic elastomer compositions obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 7-9.

[Flexibility (A hardness)]
The plate was allowed to stand in a constant temperature and humidity room (temperature 23°C, relative humidity 50%) for 24 hours or more to stabilize the state of the sheet. Three press sheets with a thickness of 2 mm were stacked, and the A hardness was measured according to JIS K7215 "Durometer hardness test method for plastics".

[Mechanical strength (tensile breaking strength)]
From the plate, a No. 3 test piece described in JIS K7113 was prepared using a die cutting machine, and a tensile tester (Autograph AG-50kND type) manufactured by Shimadzu Corporation was used in a temperature environment of 23 ° C. The specimen was pulled at a speed of 500mm/min. The stress (MPa) at which the specimen broke was recorded as the breaking strength. The higher the breaking strength, the better the mechanical strength.

〔Liquidity〕
(1) Melt mass flow rate (MFR)
Measured at 230°C and a nominal load of 5 kg in accordance with ASTM D1238.

(2) Melt viscosity
Measured with a capillary rheometer at 190°C and a shear rate of 180 sec ^-1 according to JIS K 7199.

[Co-extrusion moldability]
A thermoplastic elastomer composition and ABS resin (Daicel Polymer Co., Ltd., Zebian V500SF) are co-extruded by a co-extrusion device that combines a single-screw main extruder with a screw diameter of 40 mm and a single-screw sub-extruder with a screw diameter of 40 mm. molded into a packing. ABS resin was supplied to the main extruder, the barrel temperature and die temperature were set at 200° C., and the screw rotation speed was 14 r/min. The thermoplastic elastomer composition was supplied to the sub extruder, and the barrel temperature and die temperature were set at 180° C., and coextrusion molding was performed at a screw rotation speed of 15 r/min. FIG. 1 shows a cross-sectional view of the molded body molded by the main extruder, FIG. 2 shows a cross-sectional view of the molded body molded by the sub-extruder, and FIG. 3.
The appearance of the door stop packing thus obtained was visually observed to check for warpage and separation between the thermoplastic elastomer composition and the ABS resin.

[Thermal adhesion]
Peel strength was measured at an ambient temperature of 23° C. using a fused test piece obtained by co-extrusion molding in accordance with JIS K6854-2 "Adhesive Peeling Bond Strength Test Method (180 degree peeling)". Using the thermoplastic elastomer layer as a flexible adherend and the ABS resin layer as a rigid adherend, a tensile test was performed on the elastomer layer in a 180° direction at 50 mm/min to determine the peel strength between the surface material layer and the base material layer (unit: N/25mm) was measured.

From the above results, the thermoplastic elastomer compositions of Examples 1 to 13 are excellent in fluidity and heat-sealability with the polar resin, and by co-extrusion molding, good door contact without warping or peeling of members. It can be seen that the packing is obtained.
On the other hand, the thermoplastic elastomer compositions of Comparative Examples 1 to 3, 5, and 7 to 9 do not have proper fluidity, and the door stop packing warps. Further, the thermoplastic elastomer compositions of Comparative Examples 1, 3, 4, 6, and 8 lacked the heat-sealing property with the polar resin, so that the members of the door stop packing were peeled off.

The thermoplastic elastomer composition of the present invention is used in various molded articles used in automobiles, machinery, construction materials, clothing, electronic materials, food containers, household appliances, electrical equipment, medical tools, packaging materials, stationery and miscellaneous goods, and the like. In particular, it is suitably used as a member of a door stop packing.

Claims (17)

A thermoplastic elastomer composition containing a thermoplastic styrene elastomer A, a softening agent B, a polyester block copolymer C1 and/or a polyurethane block copolymer C2, a compatibilizer D, and a thickener E, , the polyester-based block copolymer C1 is a polyester-polyether block copolymer having an aromatic polyester block as a hard segment and an aliphatic polyether block as a soft segment, and the thermoplastic styrene-based elastomer A 100 With respect to parts by mass, the content of the softening agent B is 5 to 50 parts by mass, the content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 is 50 to 250 parts by mass, and the phase The content of the solubilizer D is 5 to 30 parts by mass, the content of the thickener E is 5 to 30 parts by mass, and the content of the softener B in the thermoplastic elastomer composition is 10.1 to 15 parts. A thermoplastic elastomer composition in which the content of the polyester block copolymer C1 and/or the polyurethane block copolymer C2 is 35 to 50% by mass. The thermoplastic elastomer composition according to Claim 1, wherein the thermoplastic elastomer composition has a melt viscosity of 1,200 to 2,200 Pa·S at 190°C and 180 (1/sec). 3. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition has a melt mass flow rate of 3 g/10 min or less under conditions of 230° C. and a nominal load of 5 kg. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the A hardness of the thermoplastic elastomer composition is 30-80. The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the thermoplastic styrene elastomer A has a weight average molecular weight of 50,000 to 500,000. The thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the thermoplastic styrene elastomer A contains a controlled distribution styrene block copolymer. The thermoplastic elastomer composition according to any one of claims 1 to 6, wherein the softener B contains at least one selected from paraffinic oils and naphthenic oils. The thermoplastic elastomer composition according to any one of claims 1 to 7, wherein the softener B has a kinematic viscosity at 40°C of 30 to 500 mm ² /s. The thermoplastic elastomer composition according to any one of claims 1 to 8, wherein the polyester-based block copolymer C1 has a hard segment and a soft segment at a mass ratio (hard segment/soft segment) of 10/90 to 30/70. . The thermoplastic elastomer composition according to any one of claims 1 to 9, wherein the compatibilizer D contains a maleic acid-modified hydrogenated thermoplastic styrene elastomer. The thermoplastic according to any one of claims 1 to 10, wherein the thickener E contains at least one selected from the group consisting of epoxy compounds, polycarbodiimide compounds, ionomers, and (meth)acrylic acid alkyl ester polymers. Elastomer composition. The thermoplastic elastomer composition according to any one of claims 1 to 11, which is a thermoplastic elastomer composition for co-extrusion molding with a polar resin. A composite molded article obtained by heat-sealing the thermoplastic elastomer composition according to any one of claims 1 to 11 and a polar resin. 14. The molded composite of claim 13, wherein the polar resin is acrylonitrile-butadiene-styrene resin. 15. The composite molded article according to claim 13 or 14, which is a co-extruded article of the thermoplastic elastomer composition and the polar resin. A doorstop packing, which is a composite molded product obtained by heat-sealing the thermoplastic elastomer composition according to any one of claims 1 to 11 and an acrylonitrile-butadiene-styrene resin. 17. The door stop packing according to claim 16, wherein the composite molded body is a co-extruded body of the thermoplastic elastomer composition and the acrylonitrile-butadiene-styrene resin.

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