JPH11349821A - Thermoplastic resin composition having excellent stability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition, which is excellent in discoloration resistance, light fastness and mechanical characteristics, by compounding specified amounts of a crosslinkable elastomer, a thermoplastic resin and a lactone stabilizer to provide a partially or fully crosslinked composition. SOLUTION: The composition comprises 1 to 99 parts by weight (hereinafter referred to simply as parts) of a crosslinkable elastomer preferably made of a copolymer consisting of two or more vinyl monomers, 1 to 99 parts of a thermoplastic resin preferably made of an olefin resin, and a lactone stabilizer preferably made of a compound of the following formula and used in an amount of 0.0001 to 50 parts per 100 parts in total of the former two wherein the partially or fully crosslinked elastomer exists as islands in the matrix of the thermoplastic resin. In the formula, R1 and R2 independently represent a 1-20C hydrocarbon; m is 0 to 4; and n is 0 to 5. It is preferred that the crosslinkable elastomer consists of a copolymer of ethylene and a 3-20C α-olefin and is prepared by use of a metallocene catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent stability. More specifically,
The present invention relates to a thermoplastic resin composition having excellent discoloration resistance, light resistance, and mechanical strength.

[0002]

2. Description of the Related Art A thermoplastic resin composition has excellent impact resistance in addition to excellent moldability, and is therefore used in various fields such as automobile parts, home electric appliance parts, and OA equipment parts. However, depending on the conditions of use, its use is limited due to lack of long-term stability.

As a method for stabilizing a thermoplastic resin composition, it is known to add a phenolic antioxidant, a phosphorus antioxidant, an ultraviolet absorber and an amine light stabilizer to a resin. Thus, although some degree of stabilization is achieved, improvement in long-term stability is required. In recent years, for the purpose of automotive parts and the like, a radically crosslinkable olefin elastomer and an olefin resin having no radical crosslinkability such as PP are crosslinked while being melt-kneaded in an extruder in the presence of a radical initiator. Thermoplastic resin compositions by crosslinking are widely used.

In such a thermoplastic resin composition, ethylene-propylene-diene rubber (EPDM) has been conventionally used as an olefin elastomer. Although EPDM is excellent in crosslinkability due to the presence of a diene component in the polymer chain, it has been desired to improve the quality due to poor long-term stability such as resistance to environmental degradation.

On the other hand, JP-A-8-120127 and JP-A-9-137001 disclose a technique using an olefin elastomer produced with a metallocene catalyst. However, the composition disclosed in the above publication does not always have sufficient discoloration resistance, light resistance, and mechanical strength, and a thermoplastic resin composition that can withstand practical use is required.

[0006]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is free from the above-mentioned problems, that is, a thermoplastic resin by dynamic crosslinking excellent in discoloration resistance, light resistance and mechanical properties. It is intended to provide a composition.

[0007]

Means for Solving the Problems The present inventors have intensively studied a thermoplastic resin composition by dynamic crosslinking having excellent stability and found that a lactone-based stabilizer was used for a specific resin composition. As a result, it was surprisingly found that the stability was dramatically improved, and the present invention was completed. That is, the present invention relates to (A) 1 to 99 parts by weight of a crosslinkable elastomer,
(B) 1 to 99 parts by weight of a thermoplastic resin [(A) and (B)
Is 100 parts by weight] and (C) a lactone-based stabilizer in an amount of 0.0001 to 50 parts by weight, and a partially or completely crosslinked thermoplastic resin composition. Hereinafter, the present invention will be described in detail.

[0008] The composition of the present invention is a partially or completely crosslinked thermoplastic resin composition comprising (A) a crosslinkable elastomer, (B) a thermoplastic resin, and (C) a lactone stabilizer. . Here, it is preferable that the rubber component (A) partially or completely crosslinked exists as an "island" in the "sea" of (B). Further, (C) is particularly preferable when a lactone ring is present and has an active hydrogen at the α-position, since a stable radical is more easily generated, and radical scavenging ability is drastically improved.

Hereinafter, each component of the present invention will be described in detail. In the present invention, (A) the crosslinkable elastomer comprises:
For example, polystyrene, polyolefin, polyester, polyurethane, 1,2-polybutadiene,
It is a polyvinyl chloride type or the like, and particularly preferably a polyolefin type thermoplastic elastomer.

Among the polyolefin-based thermoplastic elastomers (A), an ethylene / α-olefin copolymer rubber is particularly preferable.
And ethylene-α-olefin copolymer rubber comprising 20 α-olefins. Α having 3 to 20 carbon atoms
Examples of the olefin include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, and the like. Is mentioned. Among them, hexene-1, 4-methylpentene-1 and octene-1 are preferred, and octene-1 is particularly preferred. Octene-1 is excellent in softening effect even in a small amount,
The obtained copolymer has excellent mechanical strength.

The polyolefin elastomer suitably used in the present invention is preferably produced by using a known metallocene catalyst or Ziegler catalyst. Generally, a metallocene-based catalyst is an IV such as titanium or zirconium.
Consisting of a cyclopentadienyl derivative of a group metal and a co-catalyst, it is not only highly active as a polymerization catalyst, but also has a narrower molecular weight distribution of the resulting polymer compared to a Ziegler-based catalyst. Α having a certain carbon number of 3 to 20
The olefin distribution is uniform and suitable.

The (A) polyolefin elastomer suitably used in the present invention preferably has an α-olefin copolymerization ratio of 1 to 50% by weight, more preferably 10 to 40% by weight, most preferably. Is 20 to 30% by weight. α-olefin copolymerization ratio is 50% by weight
If it exceeds 1, the hardness, tensile strength and the like of the composition are greatly reduced, while if it is less than 1% by weight, the hardness of the composition is high and the mechanical strength tends to be reduced.

The density is 0.8 to 0.9 g / c.
It is preferably in the range of m ³ . By using a polyolefin-based elastomer having a density in this range, a thermoplastic elastomer composition having excellent flexibility and low hardness can be obtained. In particular, when the following equation (a) is satisfied between the copolymerization ratio c (% by weight) and the density d (g / cm ³ ): -0.0026 × c + 0.9200 ≦ d ≦ −0.0026 × c + 0.9400 (a) It is more preferable because the balance between the mechanical strength and the physical properties of the hardness of the elastomer is excellent. If the density d is lower than this range, the mechanical strength is insufficient, and if the density d is higher than this range, oil bleed tends to occur, which is not preferable.

The polyolefin elastomer used in the present invention preferably has a long-chain branch.
With the presence of long-chain branching, without reducing the mechanical strength
The density can be made smaller than the ratio (% by weight) of the copolymerized α-olefin, and a low-density, low-hardness, high-strength elastomer can be obtained. The olefin elastomer having a long chain branch is described in US Pat. No. 5,278,272.

Further, the polyolefin-based elastomer includes:
It is desirable to have a melting point peak of DSC above room temperature. When it has a melting point peak, the form is stable in the temperature range below the melting point, the handleability is excellent, and the stickiness is small. Further, the melt index of the polyolefin-based elastomer used in the present invention is 0.01 to 100 g.
/ 10 minutes (190 ° C., 2.16 kg load) are preferably used, and more preferably 0.2 to 10 g / min.
10 minutes. If the amount exceeds 100 g / 10 minutes, the crosslinking property of the thermoplastic elastomer composition is insufficient, and the crosslinking rate of the thermoplastic elastomer composition is too low.
If it is less than 01 g / 10 minutes, the fluidity is poor and the processability is undesirably reduced.

(A) used in the present invention may be a mixture of a plurality of types. In such a case, it is possible to further improve the workability. In the present invention, the thermoplastic resin (B) is not particularly limited as long as it is compatible with or homogeneously dispersed with (A). For example, polystyrene, polyphenylene ether,
Polyolefin type, polyvinyl chloride type, polyamide type,
Polyesters, polyphenylene sulfides, polycarbonates, polymethacrylates and the like can be used alone or in combination of two or more. In particular, an olefin resin such as a propylene resin is preferable as the thermoplastic resin.

Specific examples of the propylene resin most preferably used in the present invention include homo isotactic polypropylene, propylene and other α-olefins such as ethylene, butene-1, pentene-1 and hexene-1. Examples include an isotactic copolymer resin with olefin (including block and random). At least one or more thermoplastic resins (B) selected from these resins are (A) and (B)
Is used at a composition ratio of 1 to 99 parts by weight based on a total of 100 parts by weight. Preferably 5 to 90 parts by weight, more preferably 2
0 to 80 parts by weight, most preferably 20 to 70 parts by weight. If the amount is less than 1 part by weight, the fluidity and processability of the composition are reduced, and if it exceeds 99 parts by weight, the flexibility of the composition is insufficient, which is not desirable.

The propylene resin used in the present invention has a melt index of 0.1 to 100 g / 10
Min (230 ° C., 2.16 kg load) is preferably used. If it exceeds 100 g / 10 minutes, the heat resistance and mechanical strength of the thermoplastic elastomer composition will be insufficient, and if it is less than 0.1 g / 10 minutes, the fluidity will be poor and the moldability will be reduced, which is not desirable. .

In the present invention, (C) the lactone-based stabilizer is added in an amount of 0.1 to 100 parts by weight of the total of (A) and (B).
0001 to 50 parts by weight are used. If the amount is less than 0.0001 part by weight, the stabilizing effect is not sufficient, and if it exceeds 50 parts by weight, the performance as a composition is reduced. (C) A lactone stabilizer is a compound having an intramolecular ester group in which a hydroxy acid is cyclized by esterification between a carboxyl group and a hydroxyl group. The lactone is preferably a 5-membered γ-lactone or a 6-membered δ-lactone. Lactones having hydrogen at the α-position are particularly preferred.

As the above (C), a compound represented by the following formula is preferable.

[0021]

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In particular, R1 is a t-butyl group, and m is 2
Wherein R 2 is a methyl group, n is 2 and substituted at the 3 and 4 positions (see below)
Is more preferred.

[0023]

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In the present invention, a softening agent can be blended as required to improve workability. The softening agent is preferably a paraffinic or naphthenic process oil. These are used in an amount of 5 to 250 parts by weight, preferably 10 to 150 parts by weight, for adjusting the hardness and flexibility of the composition. If the amount is less than 5 parts by weight, flexibility and workability are insufficient, and 250
Exceeding the parts by weight results in significant oil bleeding, which is undesirable.

The thermoplastic resin composition provided by the present invention comprises the above-mentioned (A) specific olefin elastomer, (B) propylene polymer, (C) lactone stabilizer, and rubber oil. By combining them in a specific composition ratio, the balance between stability, mechanical strength and flexibility, and workability is improved, and they can be preferably used. The thermoplastic resin composition provided by the present invention requires that the composition be partially cross-linked by a radical initiator such as an organic peroxide or a radical initiator and a crosslinking assistant. Thereby, it becomes possible to further improve the wear resistance, mechanical strength, heat resistance, and the like.

Here, specific examples of the radical initiator preferably used include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane,
1,1-bis (t-hexylperoxy) -3,3,5
-Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-
Butylperoxy) cyclododecane, 1,1-bis (t
-Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,
Peroxy ketals such as 4-bis (t-butylperoxy) butane and n-butyl-4,4-bis (t-butylperoxy) valerate; di-t-butyl peroxide, dicumyl peroxide, t -Butylcumyl peroxide, α, α′-bis (t-butylperoxy-m
-Isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5 Dialkyl peroxides such as -bis (t-butylperoxy) hexine-3; acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexa Diacyl peroxides such as noyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butylperoxyacetate, t
-Butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate,
Di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate Peroxyesters; and
Hydrogens such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide Peroxides can be mentioned.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.

These radical initiators include (A) 100
0.02 to 3 parts by weight, preferably 0.02 parts by weight,
It is used in an amount of 5 to 1 part by weight. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if it exceeds 3 parts by weight, the physical properties of the composition are not improved, which is not preferable. Further, as a crosslinking aid, divinylbenzene, triallyl isocyanurate,
Triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate,
Triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P- quinone dioxime, P, P ^'- dibenzoyl quinone dioxime, phenylmaleimide, allyl methacrylate, N, ^{N'-m-phenylene} bismaleimide, diallyl Phthalate, tetraallyloxyethane, 1,2
-Polybutadiene and the like are preferably used. These crosslinking aids may be used in combination of two or more.

These crosslinking assistants are used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, per 100 parts by weight of (A). If the amount is less than 0.1 part by weight, crosslinking is insufficient, and if it exceeds 5 parts by weight, the physical properties of the composition are not improved, and an excessive amount of a crosslinking aid remains, which is not preferable. Further, other resins and elastomers may be added to the thermoplastic resin composition of the present invention to such an extent that its characteristics are not impaired.

In particular, a block copolymer comprising at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound, or a block copolymer of this type. The addition of a block copolymer obtained by hydrogenating the coalesced oil is preferable because the oil retention can be dramatically improved.

In the present invention, the block copolymer may be, for example, AB, ABA, BABA, ABA
-BA, BABAB, (AB) ₄ Si,
It has a structure such as (BAB) ₄ Si and (BAB) ₄ Sn. The polymer block mainly composed of a vinyl aromatic compound is a copolymer block of a vinyl aromatic compound containing 50% by weight or more of a vinyl aromatic compound and a conjugated diene compound and / or a homopolymer block of a vinyl aromatic compound. Show.

The polymer block mainly composed of a conjugated diene compound refers to a copolymer block of a conjugated diene compound containing at least 50% by weight of a conjugated diene compound and a vinyl aromatic compound and / or a homopolymer block of a conjugated diene compound. Show. As the vinyl aromatic compound constituting the block copolymer, one or more of styrene, methylstyrene, 1,3-dimethylstyrene, p-tert-butylstyrene and the like can be used. Among them, styrene is preferred.

As the conjugated diene compound constituting the block copolymer, one or more of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like can be used. . Among them, butadiene, isoprene and a combination thereof are preferred. As a method for producing these block copolymers, any known method may be used, for example, a method of block-polymerizing a vinyl aromatic compound and a conjugated diene compound using a polymerization initiator such as an organic lithium compound in a hydrocarbon solvent. Can be obtained by subjecting the above block copolymer to a hydrogenation reaction. The method of the hydrogenation reaction may be any known method, for example, hydrogenation can be performed in an inert solvent in the presence of a hydrogenation catalyst. The reaction conditions for hydrogenation are at least 80% of the conjugated diene compound,
Preferably, at least 90% is selected to be hydrogenated, while less than 20%, preferably less than 10%, of the vinyl aromatic compound is hydrogenated.

The number average molecular weight of the block copolymer having the above structure is 20,000 to 300,000, preferably 30.
000 to 200,000. In the present invention, the block copolymer has mechanical properties as an elastomer, has a high oil holding ability, and has a property of being crosslinked by a radical initiator. Therefore, by having the block copolymer as one component, the composition of the present invention can hold a large amount of rubber oil, and it becomes easy to obtain a low hardness composition. In the case of the dynamic crosslinking reaction, it also functions as a crosslinkable elastomer component together with the olefin-based elastomer.

The block copolymer is used in a composition ratio of 0 to 100 parts by weight. If it exceeds 100 parts by weight, the crosslinkability of the composition decreases, which is not desirable. In particular, by adding a low molecular weight ethylene polymer having a number average molecular weight of 20,000 or less, the moldability of the composition, the surface texture of the molded product, and the like are remarkably improved, which is desirable.

In the present invention, when further excellent stability is required, if necessary, an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, an active species scavenger,
One or more stability improvers selected from a light-shielding agent, a metal deactivator, and a quencher can be blended. The amount of the above-mentioned stability improver is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, most preferably 100 parts by weight of the total amount of (A) and (B). Is 1 to 5 parts by weight.

An ultraviolet absorber as a stability improver absorbs light energy and undergoes intramolecular proton transfer to form a keto-type molecule (benzophenone or benzotriazole) or cis-trans isomerization. (Cyanoacrylate type) is a component for releasing and rendering harmless as thermal energy. Specific examples are 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-
2-hydroxybenzophenones such as 4-octoxybenzophenone, 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone), 2- (2′-hydroxy-5′-methylphenyl) benzotriazole,
2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-t-
Butylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3'-t-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-dicumylphenyl) benzotriazole, 2,2 2- (2 ′) such as' -methylenebis (4-t-octyl-6-benzotriazolyl) phenol
-Hydroxyphenyl) benzotriazoles, phenyl salicylate, resorcinol monobenzoate,
2,4-di-t-butylphenyl-3 ′, 5′-di-t
Benzoates such as -butyl-4'-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyl Substituted oxanilides such as oxanilide; and cyanoacrylates such as ethyl-α-cyano-β, β-diphenylacrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate.

A hindered amine-based light stabilizer as a stability improver decomposes hydroperoxide generated by light energy to form a stable NO—radical or NO—
It is a component for generating and stabilizing R and N-OH.
A specific example is 2,2,6,6, -tetramethyl-4-
Piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6
-Tetramethyl-4-piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl sebacate, bis (1,2,2,6,6-pentamethyl-4
-Piperidyl) sebacate, tetrakis (2,2,6)
6-tetramethyl-4-piperidyl) 1,2,3,4-
Butanetetracarboxylate, tetrakis (1,2,2
2,6,6-pentamethyl-4-piperidyl) -1,
2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1 , 2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3 ',
5'-di-t-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,
6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate, 1,6- Bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-t-octylamino-s-triazine polycondensate, 1,6-bis (2,2,2 6,6-tetramethyl-
4-piperidylamino) hexane / 2,4-dichloro-
6-morpholino-s-triazine polycondensate and the like.

An antioxidant as a stability improver stabilizes peroxide radicals such as hydroperoxy radicals generated during thermoforming or light exposure, and decomposes the generated peroxides such as hydroperoxides. It is a component for performing. Examples are hindered phenolic antioxidants and peroxide decomposers. The former is a radical chain inhibitor, and the latter decomposes the peroxide generated in the system into more stable alcohols to prevent autoxidation.

Specific examples of the hindered phenol-based antioxidant as the antioxidant include 2,6-di-t-butyl-4-methylphenol, stylated phenol, and n-octadecyl-3- (3 , 5-Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2 '
-Methylenebis (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-
Di-t-pentylphenyl) ethyl] -4,6-di-t
-Pentylphenyl acrylate, 4,4'-butylidenebis (3-methyl-6-t-butylphenol),
4,4'-thiobis (3-methyl-6-t-butylphenol), alkylated bisphenol, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 3 , 9-
Bis [2- [3- (3-t-butyl-4-hydroxy-
5-methylphenyl) -propionyloxy] -1,1-
Dimethylethyl] -2,4,8,10-tetraoxyspiro [5.5] undecane.

Specific examples of the peroxide decomposer as the antioxidant include trisnonylphenyl phosphite,
Triphenyl phosphite, tris (2,4-di-t-
Organic phosphorus peroxide decomposers such as butylphenyl) phosphite or dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipro Pionate,
It is an organic sulfur peroxide decomposer such as pentaerythrityltetrakis (3-laurylthiopropionate), ditridecyl-3,3'-thiodipropionate, 2-mercaptobenzimidazole and the like.

The active species scavenger as a stability improver is
Captures free halogen generated during molding or light exposure
It is a component for. A specific example is calcium stearate.
Metal salts such as sodium and zinc stearate,
Lucite, zeolite, magnesium oxide, organotin compound
Or an organic epoxy compound. Halogen capture above
Hydrotalcite as a scavenger is made of magnesium,
Hydrous bases such as Lucium, Zinc, Aluminum and Bismuth
Carbonates and anhydrous basic carbonates, natural and synthetic products
included. As a natural product, Mg₆A₁₂(OH)₁₆CO
_Three・ 4H_TwoO-structures. Also, synthetic products
As Mg_0.7Al _0.3(OH)_Two(CO_Three)_0.15
・ 0.54H_TwoO, Mg_4.5Al_Two(OH)₁₃CO_Three・
3.5H_TwoO, Mg_4.2Al_Two(OH)_12.4CO_Three, Z
n₆Al_Two(OH)₁₆CO_Three・ 4H_TwoO, Ca₆Al_Two
(OH)₁₆CO_Three・ 4H_TwoO, Mg₁₄Bi _Two(OH)
_29.6・ 4.2H_TwoO and the like.

As the zeolite, Na ₂ O.Al
A-type zeolite represented by ₂ O ₃ · 2SiO ₂ · H ₂ O, or zeolite substituted by a metal containing at least one metal selected from metals of Groups II and IV of the periodic table. it can. And as the substitution metal, Mg, Ca, Zn, Sr, Ba, Zr,
Sn and the like, and particularly, Ca, Zn, and Ba are preferable.

The organic epoxy compound as the active species trapping agent includes epoxidized soybean oil, tris (epoxypropyl) isocyanurate, hydroquinone diglycidyl ether, terephthalic acid diglycidyl ester, and 4,4 ′.
-Sulfobisphenol / polyglycidyl ether, N
-Glycidyl phthalimide or hydrogenated bisphenol A glycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexylspiro [5,5] -3,4-epoxy ) Cyclohexane-m-
Dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene dioxide, 4-vinylepoxycyclohexane, bis (3,4
-Epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-
3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene epoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4- Epoxy cyclohexane carboxylate), dioctyl epoxy hexahydrophthalate, di-epoxy hexahydrophthalate
Alicyclic epoxy compounds such as 2-ethylhexyl;

The light-shielding agent as a stability improving agent is a component for preventing light from reaching the inside of the polymer. Specific examples thereof include rutile-type titanium oxide (TiO ₂ ), zinc oxide (ZnO), chromium oxide (Cr ₂ O ₃ ), and cerium oxide (CeO ₂ ). The metal deactivator as a stability improver is a component for forming a chelate compound and inactivating heavy metal ions in the resin in the chelate compound. Specific examples thereof include an acid amine derivative, benzotriazole, and derivatives thereof.

A quencher as a stability improver is a component for inactivating functional groups such as a photo-excited hydroperoxide and a carbonyl group in a polymer by energy transfer, and organic nickel and the like are known. I have. Others
The following polymers may be added to the composition of the present invention to such an extent that the characteristics are not impaired. Specifically, polyethylene, polybutene, polyisobutene, ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymer, ethylene-unsaturated carboxylic acid ester copolymers such as ethylene-ethyl acrylate copolymer, ethylene- And vinyl alcohol copolymer.

Further, the thermoplastic resin composition of the present invention comprises:
It is possible to contain inorganic fillers and plasticizers to such an extent that their characteristics are not impaired. Examples of the inorganic filler used here include calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide. Examples of the plasticizer include phthalic acid esters such as polyethylene glycol and dioctyl phthalate (DOP). Also, other additives, for example, organic and inorganic pigments,
Flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents and the like are also suitably used.

For the production of the thermoplastic resin composition of the present invention,
General methods such as a Banbury mixer, a kneader, a single-screw extruder, a twin-screw extruder, and the like used in the production of ordinary resin compositions and elastomer compositions can be employed. In particular, a twin-screw extruder is preferably used to achieve dynamic crosslinking efficiently. The twin-screw extruder uniformly and finely disperses the olefin-based elastomer and the propylene-based resin, further adds another component to cause a crosslinking reaction, and continuously prepares the preferred thermoplastic elastomer composition of the present invention. More suitable for manufacturing.

Dynamic crosslinking is a processing method in which a crosslinking reaction is performed in a kneading machine in a short time, and a crosslinking time (Tc90) which is an index of a crosslinking speed is 400 seconds or less, preferably 300 seconds.
A copolymer having a length of 2 seconds or less is desirable, and more preferably 2% or less.
00 seconds or less is desirable. Here, the crosslinking time (Tc90)
Is the time required to reach 90% of the maximum degree of crosslinking (viscosity) when adding 1.0 part by weight of dicumyl peroxide as a peroxide to an elastomer and measuring the vulcanization characteristics with a rheometer at 170 ° C. It is.

When the loss tangent (23 ° C.) t in the dynamic viscoelastic properties of the olefinic elastomer satisfies the following equation (b), rubber properties such as rebound resilience are further improved, and the compression permanent Rubber characteristics such as distortion and rebound resilience are excellent, which is desirable. 0.03 ≦ t ≦ 0.08 (b) In particular, when octene-1 is used as the α-olefin and the copolymerization ratio is 26 to 30% by weight, the loss tangent t is within the above range, and It becomes an excellent elastomer. Here, the measurement of the dynamic viscoelasticity is based on the following method.

Dynamic viscoelasticity measuring device; RSA-II manufactured by Rheometrics Co., Ltd. Measurement mode; Tensile Measurement frequency; 11 Hz Heating rate; 2 ° C./min Dynamic strain; 0.1% When measured under these conditions, 23 Judgment was made from the value t of the loss tangent (tan σ) at ° C. by the equation (b).

In the present invention, the form of the olefin-based elastomer and the propylene-based resin is preferably a finely divided form such as a pellet, powder, or crumb. As a specific example, the thermoplastic resin composition of the present invention can be manufactured through the following processing steps. That is, the olefin-based elastomer, the propylene-based resin, and the lactone-based stabilizer are mixed well and then charged into a hopper of an extruder. The radical initiator and the crosslinking assistant may be added together with the olefin-based elastomer, the propylene-based polymer and the lactone-based stabilizer from the beginning, or may be added in the middle of the extruder.
The oil may be added from the middle of the extruder, or may be added separately at the beginning and during the middle. The olefin-based elastomer and the propylene-based resin may be partially added in the middle of the extruder. When heated and melted and kneaded in the extruder,
The elastomer, a radical initiator and a crosslinking assistant undergo a crosslinking reaction. Further, an oil or the like is added and melt-kneaded to make the crosslinking reaction and kneading dispersion sufficient, and then the mixture is taken out of the extruder. Pelletized to obtain pellets of the preferred thermoplastic elastomer composition of the present invention.

The degree of crosslinking is defined as a measure of the crosslinkability of the composition. 0.5 g of the thermoplastic polymer composition of the present invention is refluxed in 200 ml of xylene for 4 hours. The solution is filtered through a filter paper for quantification, the residue on the filter paper is vacuum-dried, quantified, and calculated as a ratio (%) of the weight of the residue to the weight of the olefin-based elastomer in the composition. The degree of crosslinking of the thermoplastic elastomer composition as a preferred composition of the present invention is desirably 30% or more. If it is less than 30%, crosslinking is insufficient, and heat resistance such as compression set and physical properties such as rebound resilience are reduced.

The suitable thermoplastic elastomer composition thus obtained can be used to produce various molded articles by any molding method. Injection molding, extrusion molding, compression molding, blow molding,
Calender molding, foam molding and the like are preferably used.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION

[0056]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows. (1) Surface Hardness Four sheets having a thickness of 2 mm were piled up and evaluated according to ASTM D2240 using an A type in a 23 ° C. atmosphere. (2) Tensile breaking strength [kgf / cm ² ] Evaluated at 23 ° C. according to JIS K6251. (3) Tensile elongation at break [%] Evaluated at 23 ° C. according to JIS K6251. (4) Light fastness The light fastness test was performed by a US ATLAS Electric D
Using ATLAS CI35W Weatherometer manufactured by evices Co., JI
It was performed by a method based on SK7102. The irradiation conditions were: internal temperature of the tester, 55 ° C., humidity 55%, no rain, xenon light (wavelength 340 nm, energy 0.30
W / m ² ) Irradiation for 300 hours. Using SM Color Computer Model SM-3 manufactured by Suga Test Machine Co., Ltd. of Japan a. b. Color difference Δ before and after test
E was evaluated for color tone change. The smaller the change in color tone, the higher the light resistance. (5) Discoloration resistance The test piece was heated in a gear oven at 120 ° C. for 100 hours, and the ratio of the value after the heating test to the initial value of the tensile strength at break was defined as the retention of tensile strength at break (%). It was used as an index of discoloration resistance.

The following components were used in the examples and comparative examples. (A) Crosslinkable elastomer Copolymer of ethylene and octene-1 It was produced by a method using a metallocene catalyst described in JP-A-3-1630088. The ethylene / octene-1 composition ratio of the copolymer is 72/28 (weight ratio).
(B) Thermoplastic resin polypropylene Isotactic polypropylene (referred to as PP) manufactured by Nippon Polychem Co., Ltd. (c) Stabilizer Lactone-based stabilizer Lactone-based compound [Ciba Specialty Chemicals] HP-136 (LT) manufactured by Co., Ltd.] Phosphite stabilizer Ciba Specialty Chemicals Co., Ltd., Irgafos 168 (PT) hindered phenol stabilizer Ciba Specialty Chemicals Co., Ltd. Manufactured by Irganox 1076 (referred to as OH) (d) Paraffin oil Diana Process Oil PW-3 manufactured by Idemitsu Kosan Co., Ltd.
80 (referred to as MO) (e) Radical initiator 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
Butylperoxy) hexane (trade name Perhexa 25)
B) (referred to as POX) (f) Crosslinking aid divinylbenzene (referred to as DVB) manufactured by Wako Pure Chemical Industries, Ltd.

[0058]

Examples 1 to 3 and Comparative Examples 1 to 4 As an extruder, a twin screw extruder (40 mmφ, L /
D = 47) was used. As the screw, a double screw having a kneading portion before and after the injection port was used. After mixing at the composition ratios shown in Table 1, the mixture was introduced into a twin-screw extruder (cylinder temperature: 220 ° C.) to perform melt extrusion. However, for the composition using MO, after mixing other than MO, the mixture is introduced into a twin-screw extruder (cylinder temperature 220 ° C.), and then a predetermined amount of MO is injected by a pump from an injection port at the center of the extruder. Then, melt extrusion was performed.

From the elastomer composition thus obtained, a sheet having a thickness of 2 mm was prepared by compression molding at 200 ° C., and each mechanical property and stability property were evaluated. Table 1 shows the results.

[0060]

[Table 1]

According to Table 1, it can be seen that the lactone stabilizer can impart excellent stability such as excellent light fastness and discoloration fastness.

[0062]

The thermoplastic resin composition of the present invention has excellent discoloration resistance, light resistance, and mechanical strength. The composition of the present invention can be used for automotive parts, automotive interior materials, airbag covers, mechanical parts, electrical parts, cables, hoses, belts, toys, miscellaneous goods, daily necessities, building materials, sheets, films, and other applications. It can be used widely and plays a large role in the industrial world.

Claims (6)

[Claims] 1. (A) 1 to 99 parts by weight of a crosslinkable elastomer, (B) 1 to 99 parts by weight of a thermoplastic resin [total amount of (A) and (B) is 100 parts by weight], and (C) lactone A partially or completely crosslinked thermoplastic resin composition comprising 0.0001 to 50 parts by weight based on 100 parts by weight of the total amount of the system stabilizers (A) and (B). 2. The thermoplastic resin composition according to claim 1, wherein (C) is represented by the following formula. Embedded image (R1 and R2 are hydrocarbons having 1 to 20 carbon atoms, m is 0 to 4
And n represents an integer of 0 to 5) 3. The thermoplastic resin composition according to claim 1, wherein (A) is a copolymer comprising at least two kinds of vinyl monomers. 4. A method according to claim 1, wherein (A) is ethylene and α having 3 to 20 carbon atoms.
The thermoplastic resin composition according to claim 3, which is an ethylene / α-olefin copolymer rubber composed of an olefin. 5. The method according to claim 1, wherein (B) is an olefin resin.
5. The thermoplastic resin composition according to any one of items 4 to 4. 6. The thermoplastic resin composition according to claim 1, wherein (A) is produced using a metallocene catalyst.