JPS63289045A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in thermal aging resistance, by mixing a thermoplastic polyolefin resin with a specified modified ethylene/alpha- olefin/(nonconjugated diene) copolymer. CONSTITUTION:A mixture of ethylene (a) with an alpha-olefin (b) and, optionally, a nonconjugated diene is copolymerized with a silane compound of formula I (wherein n >=1, m is 0-2, X is Cl or Br, R<1> is H or a 1-5C alkyl) and/or a silane compound (c) of formula II (wherein l is 0-2, k is 0-6, and R<2-4> are each R<1>) at 0-100 deg.C in the presence of a Ziegler/Natta catalyst, and a polysiloxane compound (d) of formula III (wherein p and q are each 5-10,000, r and s are each 0-1, R<5-10> are each a 1-6C alkyl, phenyl or vinyl and R<11-14> are each R<1>) is grafted onto the obtained copolymer to obtain a modified ethylene/alpha-olefin/(conjugated diene) copolymer (B). 100pts.wt. mixture comprising 15-70pts.wt. thermoplastic polyolefin resin (A) and 30-85pts.wt. component B is mixed with 0.1-10pts.wt. crosslinking agent (C) which is an organic peroxide or a thermosetting resin to obtain the title composition in which component B is crosslinked with component C.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a thermoplastic elastomer composition, and more particularly to a modified ethylene-α-olefin copolymer and/or a modified ethylene copolymer obtained by grafting polysiloxane. The present invention relates to a thermoplastic elastomer composition having excellent heat resistance and containing a copolymer in which an α-olefin-nonconjugated diene copolymer component is crosslinked.

[Conventional technology]

Conventional thermoplastic polyolefin elastomers include, for example, those obtained by simply blending polypropylene with ethylene-α-olefin rubber, and those obtained by blending polypropylene with ethylene-α-olefin rubber.
Some have crosslinked α-olefin rubber parts. Various types of the latter are manufactured depending on the type of crosslinking agent used, and most of them use organic peroxides or resin crosslinking agents. However, since both thermoplastic elastomers use ethylene-α-olefin rubber, their heat resistance is limited.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a thermoplastic elastomer composition that has better heat aging resistance than conventional polyolefin thermoplastic elastomer compositions.

[Means for solving problems]

As a result of intensive research to achieve the above object, the present inventors have discovered that a modified ethylene-α-olefin copolymer and/or Modified ethylene-α-olefin-nonconjugated diene copolymer: r
(sometimes referred to as "si-EP") 30-85f! ?
The present invention was achieved by discovering that a thermoplastic elastomer composition with excellent heat aging resistance can be obtained by mixing the "IT" part and crosslinking with an organic peroxide, a thermosetting resin, etc.

That is, the present invention provides polyolefin thermoplastic resin 1
5 to 70 parts by weight, and 30 to 85 parts by weight of a modified ethylene-α-olefin copolymer and/or a modified ethylene-α-olefin-nonconjugated diene copolymer obtained by grafting a polysiloxane compound. , and the copolymer is crosslinked with a crosslinking agent.

The polyolefin thermoplastic resin used in the present invention is
A crystalline polyolefin homopolymer and/or a crystalline olefin ethylene copolymer containing 1 to 25% by weight of ethylene, of which MFR (melt flow rate) is 0.5 to 15 g/10 min (measurement condition 230
℃ and a load of 2160 g) is preferable. If the MFR is too small, the molding processability of the resulting thermoplastic elastomer composition may deteriorate, and if the MFR is too large, the fluidity is too high and shearing force is applied during the crosslinking reaction, resulting in a composition with poor dispersion. may be obtained.

The polyolefin thermoplastic resin is a homopolymerization of propylene, butene-1,3-methylbutene-1,4-methylpentene=1 group (a) olefin, and/or a homopolymerization of an olefin of group (a) and ethylene. , pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-i undecene-1, dodecene-1, two or more copolymers with olefins of group (b), specifically is polypropylene, polybutene-1, poly-3-methylbutene-1, poly-4-methylpentene-1, ethylene-propylene copolymer, propylene-butene-1 copolymer, propylene-3-methylbutene-1 copolymer , propylene-4-methylpentene-1 copolymer, hexene-1,4-methylpentene-1 copolymer, and the like.

5i-EPfl used in the present invention has (a) ethylene, (b) α-olefin or α-olefin and non-conjugated diene, (C) general formula ■ CH2=CH+CH2) n-3t-R1mX3-m
(1) (where n is an integer of 1 or more, m is an integer of O to 2, X is a chlorine atom or a bromine atom, and R1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) A silane compound and/or a silane compound of the general formula (1) (where β is an integer of O to 2, k is an integer of O to 6, X is a chlorine atom or a bromine atom, R2, R3, and R4 are the same or different, and A silane compound represented by an atom or an alkyl group having 1 to 5 carbon atoms is copolymerized using a Ziegler-Natsuta catalyst, and is further copolymerized with (d + general formula
p and q are integers from 5 to 10,000, r and S are O
Or 1, R11, R6, R? , R8, R9 and R
10 are the same or different and are an alkyl group having 1 to 6 carbon atoms, a phenyl group or a vinyl group, Ro%R12,
R13 and R14 are the same or different from each other and are a graft copolymer obtained by grafting compounds represented by a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

Examples of the α-olefin include propylene, butene-1, pentene-1, hexene-11 heptene-1,
Octene-1, nonene-1, decene-14-methylpentene-1,4-methylhexene-1,4,4-dimethylpentene-1,5-methylhebutene-1,6-methylhebutene-1, etc. Propylene is particularly preferred.

Examples of the non-conjugated diene include ethylidenenorbornene, propenylnorbornene, dicyclopentadiene, 1,4-hexadiene, and 4,7°8.9-tetrahydroindene.

Examples of the silane compound represented by the general formula (2) include (2-propenyl)dimethylchlorosilane, (3-butenyl)dimethylchlorosilane, (4-pentenyl)dimethylchlorosilane, and (5-hexenyl)dimethylchlorosilane. , (6-hebutenyl)dimethylchlorosilane, (
7-octenyl)dimethylchlorosilane, (2-propenyl)methyldichlorosilane, (3-butenyl)methyldichlorosilane, (4-pentenyl)methyldichlorosilane, (5-hexenyl)methyldichlorosilane, (6
-hebutenyl)methyldichlorosilane, (7-octenyl)methyldichlorosilane, (2-propenyl)trichlorosilane, (3-butenyl)trichlorosilane, (4
-pentenyl) trichlorosilane, (5-hexenyl)
Examples include trichlorosilane, (6-hebutenyl)trichlorosilane, (7-octenyl)trichlorosilane, and the like.

Examples of the silane compound represented by the general formula (2) include 5-trichlorosilyl-2-norbornene, 5-methyldichlorosilyl-2-norbornene, and 5-dimethylchlorosilyl-2-norbornene.

Among these compounds, (5-hexenyl)dimethylchlorosilane, (7-octenyl)dimethylchlorosilane, 5-methyldichlorosilyl-2-norbornene, −
Particularly preferred are dimethylchlorosilyl-2-norbornene and the like.

As the compound represented by the general formula (2), commercially available silicone oils modified with hydroxyl groups at both ends and carbinol-modified silicone oils at both ends can be used. Specifically, for example, polydiphenylsiloxane-terminated silanol, polydimethylsiloxane-terminated silanol, Polydimethyldiphenylpolysiloxane-terminated diphenylsilanol, polydimethylmethylvinylsiloxane-terminated silanol, polydimethylsiloxane-terminated carbinol, and the like are used.

The Ziegler-Natsuta catalyst used in the present invention generally refers to Ti
, Zr, V-SCr and other transition metals as necessary.
It is a catalyst that combines a transition metal component supported on a carrier such as 12, S i02, A1203, and an organometallic component consisting of an alkyl compound or haloalkyl compound such as AI Mg, Li, etc. That is, as the transition metal compound, for example, a metal halide such as titanium, zirconium, vanadium, or chromium is used, and titanium or vanadium compounds are particularly preferred. As the total pressure alkyl compound, for example, an extra pressure alkyl compound such as aluminum, magnesium, lithium, etc. or a haloalkyl compound is used, and an organic aluminum compound is particularly preferred.

When producing the graft copolymers (Si-EPs), first the monomers (a1 ethylene, (b) an α-olefin or an α-olefin and a non-conjugated diene, and (C) the general formula 1 and/or The silane compound represented by (2) is dissolved in a nonpolar solvent such as n-hexane, n-hebutane, or cyclohexane, and copolymerized using a Ziegler-Natsuta type catalyst.

At this time, the amount of these monomers to be used can be varied depending on the content of the components derived from each heptamer in the desired copolymer.

Polymerization conditions include 0 to 100°C, preferably 20 to 9°C.
A temperature of 0° C. and a pressure of 0 to 20 atmospheres, preferably 0 to 10 atmospheres are preferred.

During polymerization, as a polymerization activator, for example, halogenated acetate such as ethyl trichloroacetate, butyl trichloroacetate, dichloroacetic acid, 1.1゜2.3.3-butyl pentachlorobutenoate, 1゜1.2.3- Halogen-substituted butenoic acid esters such as ethyl tetrachlorobutenoate, α,
Halogen-containing organic compounds such as α,α-trichlorotoluene and hexachlorobutadiene can be added.

Hydrogen gas is also used as a molecular weight regulator of the copolymer during polymerization.
Alkylzinc compounds and the like can also be used.

The weight ratio of ((a) ethylene/(b) α-olefin) in the copolymer thus obtained is 80/20 to 80/20 in terms of crystallinity, temperature dependence, cold resistance, mechanical strength, etc. 20
/80 is preferred, and 75/25 to 25/75 is particularly preferred.

The content of non-conjugated diene in the copolymer is preferably 30 or less in terms of iodine value, particularly preferably 25 or less, from the viewpoint of ozone resistance.

In addition, (c) the above general formula I and/or ■ in the copolymer
The content of the component derived from the silane compound represented by is preferably 0.1 to 5% by weight of the copolymer. If the content of such a silane compound is too small, the effect on improving heat resistance may be insufficient, and if it is too large, the degree of grafting will increase too much.
As a result, workability may deteriorate.

Next, when the reaction rate has sufficiently increased in the copolymerization reaction, +d) the compound of the general formula (2) is added to the system, and after stirring to advance the grafting reaction, the polymerization reaction is stopped.

The amount of the compound of general formula (■) to be added is determined relative to the content of (C) in the copolymer.
It is preferable to add it at a ratio of 2 times molar to 1 molar equivalent of i. In this case, the content of (c) can be quantified by analysis using absorption based on CII 3 before grafting.

As the polymerization terminator, for example, dehydrated methanol, dehydrated ethanol, dehydrated isopropyl alcohol, etc. are used.

Polyolefin thermoplastic resin and 5i-
The blending ratio with EP is 15 to 70 parts by weight of the polyolefin thermoplastic resin and 1 part by weight of 30 to 85 parts by weight of 5i-EP. If the polyolefin thermoplastic resin is less than 15% by weight, the fluidity of the resulting thermoplastic elastomer composition will be extremely reduced, resulting in poor moldability, and if the polyolefin thermoplastic resin exceeds 70% by weight, the resulting thermoplastic elastomer composition will have poor flowability. The impact resistance of the thermoplastic elastomer composition decreases and the hardness becomes too high.

In the production of the thermoplastic elastomer composition of the present invention, organic peroxides, thermosetting resins, etc. are used as crosslinking agents. Examples of organic peroxides include 2゜5-dimethyl-2,5
-di(t-butylperoxy)hexyne-3,2,5-
Dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, 2,2'-bis(t-butylperoxy)
-p-diisopropylbenzene, dicumyl peroxide, di-t-butyl peroxide, L-butylbenzony), i,1-bis(t-butylperoxy)-3,
Examples include 3,5-trimethylcyclohexane and 2,4-dichlorobenzoyl peroxide, preferably 2,
5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, 2,21-bis(t-butylperoxy>-p-isopropyl) Benzene and the like are used, and examples of thermosetting resins include alkylphenol formaldehyde resins, melamine-formaldehyde condensates, and triazine-formaldehyde condensates, and alkylphenol formaldehyde resins are preferably used.

The amount of the crosslinking agent is 5% to 5% of the polyolefin thermoplastic resin.
0.1 to 10 parts by weight per 100 parts by weight of the t-EP mixture
It is preferably used in a range of parts by weight, more preferably 0.2 to 6 parts by weight. If the amount of crosslinking agent is too small, crosslinking may be incomplete and mechanical strength may be insufficient; if it is too large, overcrosslinking may occur.

In producing the thermoplastic elastomer composition and composition of the present invention, in addition to the polyolefin thermoplastic resin, 5i-EP, and crosslinking agent, extender oil, reinforcing agent, anti-aging agent, crosslinking aid, etc. may be added as necessary. can be used.

Extender oils include paraffin oil, naphthenic oil, silicone oil, etc. Reinforcers include carbon black, white carbon, basic magnesium carbonate, activated calcium carbonate, etc. Anti-aging agents include phenol, imidazole, and amine types. Anti-aging agents such as sulfur, p-benzoquinone dioxime,
p, p'-dibenzoylquinone dioxime, dinitrosobenzene, divinylbenzene, ethylene glycol dimethacrylate, triallyl isocyanurate, trimethylpropane trimethacrylate]-1 liquid polybutadiene, polybutene, polybutadiene resin, bismaleimide triazine resin, etc. can be mentioned.

In addition, in producing the thermoplastic elastomer composition of the present invention, polyethylene, ethylene propylene rubber, ethylene propylene non-conjugated diene rubber, ethylene butene-1
copolymer, ethylene butene-1 non-conjugated diene copolymer,
Olefinic (co)polymers such as propylene butene-1 copolymer, polyhexene-1, and poly-4-methylpentene-1 may also be added to the extent that the physical properties of the composition are not impaired.

The thermoplastic elastomer composition of the present invention is preferably prepared by crosslinking the polyolefin thermoplastic resin, 5i-EP, and other compounding agents in the presence of shear stress, such as in a Banbury mixer, kneader-blender, or continuous kneader. , using an extruder etc. at a temperature of 100 to 30°C above the curing temperature of the crosslinking agent.
It is obtained by kneading at 0°C, preferably 150-250°C, for 0.5-30 minutes, preferably 1-20 minutes.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

In the examples, parts or % means parts by weight or % by weight unless otherwise specified. In addition, in the following examples, the content of the compound of general formula I or (2) in the copolymer means the content in the copolymer sampled before grafting the compound of general formula (1), and Infrared spectroscopic analysis was performed on the film formed, and ethylene-
An infrared spectroscopic analysis was performed on a sample obtained by mixing the compound of general formula I or general formula (■) with an α-olefin copolymer, and a calibration curve was created using the peak based on 13i-CII3 near 1260 cm-'. I asked for it.

Example I A. Synthesis of graft copolymer Purified n-hexane 21 was charged into a separable flask with a capacity of 31 which had been purged with nitrogen gas in advance, and a mixed gas of ethylene/propylene/hydrogen = 515/4 was added to it at room temperature. Pre-dissolved. Then 5-methyldichlorosilyl-2-
Norbornene 1.25 mmol, VO (1!30.5 mmol, A Z E t 18% Cj! I,!+ 5
Millimoles were sequentially charged to start the polymerization reaction. During the polymerization reaction, a mixed gas of ethylene/propylene/hydrogen was fed in the gas phase, and the polymerization was continued at 20°C with stirring.

After 30 minutes had elapsed, a small amount of the reaction solution was sampled for analysis of propylene content and compound of general formula I or H, and then degassed silicone oil modified with both terminals of silanol (XF40-518, manufactured by Toshiba Silicone Co., Ltd.) was added.
1 ml of the mixture was added, the supply of the mixed gas was stopped, and stirring was continued for 1 hour while purging with nitrogen gas. Next, 5 m It of dehydrated methanol was added as a coalescence inhibitor to stop the polymerization reaction.

A large excess of methanol was added to the graft copolymer solution thus obtained to precipitate the polymer, which was then dried with a roll heated to 100°C. Polymer yield was 58.3 g, 45% flO containing 5-methyldichlorosilyl-2-norbornene.

B. Evaluation of physical properties The obtained graft copolymers (Si-EPs) were kneaded for 20 minutes at a temperature set at 170°C using a kneader blender with an internal volume of 11 according to the formulation shown in Table 1.
A thermoplastic elastomer composition was obtained. Next, the thermoplastic elastomer composition obtained by injection molding is
A physical property test was conducted according to K6301. The results are shown in Table 2, and showed excellent heat resistance.

Table 1 *1: Polypropylene, manufactured by Mitsubishi Yuka Co., Ltd. *2: Paraffinic process oil, manufactured by Idemitsu Kosan Co., Ltd. *3: White carbon, manufactured by Nippon Silica Co., Ltd. *4...
・HAF carbon, manufactured by Mitsubishi Chemical *b...JSRf!
PRII (manufactured by Japan Synthetic Rubber Co., Ltd.) / Burkle D (manufactured by Nihon Gosei Rubber Co., Ltd.) = 9/1 (weight ratio) Comparative Example 1 In Example 1, ethylene propylene rubber (JSRO2P manufactured by Nippon Synthetic Rubber Co., Ltd.) was used instead of 5i-EP. ) A composition was obtained in the same manner as in Example 1, except that the composition was used, and the physical properties were evaluated. The results are shown in Table 2, and the heat resistance was poor.

Example 2 A. Synthesis of graft copolymer Example L except that 5 ml of 5-ethylidene-2-norbornene was continuously charged during the polymerization reaction in Example IA.
Polymerization was carried out in the same manner as A to obtain a graft copolymer. The polymer yield was 47 g, the 5-methyldichlorosilyl-2-norbornene content was 0.47%, and the iodine number was 14.

B. Evaluation of physical properties The obtained graft copolymers (Si-EPs) were used to evaluate physical properties in the same manner as in Example IB, except that the formulation shown in Table 3 was used. The results are shown in Table 2, and showed excellent heat resistance.

Table 3 *6...Heat-reactive 100 phenolic resin Example 3 manufactured by Arakawa Chemical Industry Co., Ltd. In Example IB, 70 parts of polypropylene, S 1-
The physical properties were evaluated in the same manner as in Example IB, except that 30 parts of EP were used. The results are shown in Table 2.

Comparative Examples 2 and 3 In Example IB, the blending ratio of polypropylene and 5i-EPs was 80:20 (Comparative Example 2) and 10:90.
Physical properties were evaluated in the same manner as in Example IB except that (Comparative Example 3) was used. The results are shown in Table 2. In Comparative Example 2, the amount of polypropylene used was large, resulting in too high hardness, and in Comparative Example 3, on the other hand, the amount of 5i-EPii was large (and the fluidity was extremely low). , poor moldability.

〔Effect of the invention〕

According to the present invention, certain modified ethylene-alpha olefin-
By containing the (non-conjugated diene) copolymer, a thermoplastic elastomer composition having better heat resistance than conventional polyolefin-based thermoplastic elastomer compositions can be obtained. These are useful, for example, as boots for automobiles, interior and exterior parts, or interior and exterior parts for home appliances.

Claims (2)

[Claims] (1) 15 to 70 parts by weight of polyolefin thermoplastic resin, (a) ethylene, (b) α-olefin or α-
Olefin and nonconjugated diene, (c) general formula I CH_2
=CH-(CH_2)_n-Si-R^1_mX_3_
−_m(I) (where n is an integer of 1 or more, m is 0 to 2
, X is a chlorine atom or a bromine atom, R^1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) and/or a silane compound represented by the general formula II ▼(II) (In the formula, l is an integer of 0 to 2, k is an integer of 0 to 6, X is a chlorine atom or a bromine atom, and R^2, R^3, and R^4 are the same or different from each other. , hydrogen atom or carbon number 1
A silane compound represented by (meaning an alkyl group of In the formula, p and q are integers of 5 to 10,000, and s is 0 or 1, R^5, R^6, R^7, R^8,
R^9 and R^1^0 are the same or different and are an alkyl group having 1 to 6 carbon atoms, a phenyl group or a vinyl group, R^1^1, R^1^2, R^1^3 and R ^1
Modified ethylene-α obtained by grafting a polysiloxane compound represented by ^4, which is the same or different and represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
-Olefin copolymer and/or modified ethylene-α
-Olefin-nonconjugated diene copolymer 30-85% by weight
1. A thermoplastic elastomer composition comprising: and wherein the copolymer is crosslinked with a crosslinking agent. (2) The thermoplastic elastomer composition according to claim 1, wherein the crosslinking agent is an organic peroxide or a thermosetting resin.