JPH0819285B2 - Thermoplastic elastomer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition, more specifically, a modified ethylene-α-olefin copolymer and / or modified ethylene obtained by grafting polysiloxane. It relates to a thermoplastic elastomer composition having excellent heat resistance, which contains a copolymer in which an α-olefin-non-conjugated diene copolymer component is crosslinked.

[Conventional technology]

As the conventional polyolefin-based thermoplastic elastomer, for example, polypropylene is simply blended with ethylene-α-olefin rubber, polypropylene is blended with ethylene-α-olefin rubber, and the ethylene-α-olefin rubber portion is crosslinked. There is something I did. In the latter case, various types are manufactured depending on the type of the crosslinking agent, and most of them use an organic peroxide or a resin crosslinking agent. However, since all the thermoplastic elastomers use ethylene-α-olefin rubber, their heat resistance is limited.

[Problems to be solved by the invention]

An object of the present invention is to provide a thermoplastic elastomer composition that is more excellent in heat aging resistance than conventional polyolefin-based thermoplastic elastomer compositions.

[Means for solving problems]

The present inventors have conducted extensive studies to achieve the above-mentioned object, and as a result, modified ethylene-α-olefin copolymers and / or obtained by grafting polysiloxane to 15 to 70 parts by weight of a thermoplastic polyolefin resin. Modified ethylene-α-olefin-non-conjugated diene copolymer (hereinafter,
(Sometimes referred to as "Si-EPs") 30 to 85 parts by weight are mixed and crosslinked with an organic peroxide, a thermosetting resin or the like to obtain a thermoplastic elastomer composition having excellent heat aging resistance. The inventors have found that and reached the present invention.

That is, the present invention relates to a polyolefin-based thermoplastic resin.
15-70 parts by weight and 30-85 parts by weight of a modified ethylene-α-olefin copolymer and / or a modified ethylene-α-olefin-non-conjugated diene copolymer obtained by grafting a polysiloxane compound. The copolymer is crosslinked with a crosslinking agent.

The polyolefin-based 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, and among these, MFR (melt flow rate) is 0.5-15g / 10min (measurement condition 230 ℃, load 2160
Those of g) are preferred. If the MFR is small, the molding processability of the resulting thermoplastic elastomer composition may be poor, and if the MFR is too large, the fluidity is too high and shearing force is less likely to be applied during the crosslinking reaction, resulting in a composition in a poor dispersion state. May be obtained.

Examples of the polyolefin-based thermoplastic resin include propylene, butene-1, 3-methylbutene-1, and 4-methylpentene-1 (a) group olefin homopolymerization, and / or (a) group olefin and ethylene, Pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1.
Two or more copolymers with olefins of group (b), specifically polypropylene, polybutene-1, poly-3-methylbutene-1, poly-4-methylpentene-1, ethylene-propylene copolymer , Propylene / butene-1 copolymer, propylene-3-methylbutene-1 copolymer,
Examples thereof include propylene-4-methylpentene-1 copolymer and hexene-1,4-methylpentene-1 copolymer.

The Si-EPs used in the present invention include (a) ethylene,
(B) α-olefin or α-olefin and non-conjugated diene, (c) general formula I CH ₂ = CHCH ₂ ) _n- Si-R ¹ mX _3-m (I) (In the formula, n is an integer of 1 or more. , M is an integer of 0 to 2, X is a chlorine atom or a bromine atom, R ¹ is a hydrogen atom or a carbon number of 1 to 1.
5 means an alkyl group of 5) and / or the general formula 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, R ² , R ³ and R ⁴ are the same or different from each other, and each is a hydrogen atom or a carbon number of 1 to 1. A silane compound represented by
Copolymerization is carried out using a Natta catalyst, and (d) general formula III (In the formula, p and q are integers of 5 to 10,000, r and s are 0 or 1, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different from each other and have 1 to ¹⁰ carbon atoms. 6 alkyl group, phenyl group or vinyl group, R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are the same or different from each other and mean a hydrogen atom or a C 1-5 alkyl group). It is a graft copolymer obtained by grafting.

Examples of the α-olefin include propylene, butene-1, pentene-1, hexene-1, heptene-
1, octene-1, nonene-1, decene-1, 4-methylpentene-1, 4-methylhexene-1,4,4-dimethylpentene-1,5-methylheptene-1,6-methylheptene-1 and the like Of these, propylene is particularly preferred.

Examples of non-conjugated dienes include ethylidene norbornene, propenyl norbornene, dicyclopentadiene, 1,4-hexadiene and 4,7,8,9-tetrahydroindene.

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

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

Examples of the compound represented by the general formula I and / or II include (5-hexenyl) dimethylchlorosilane, (7-octenyl) dimethylchlorosilane, 5-methyldichlorosilyl-2-norbornene, and 5 among these compounds.
-Dimethylchlorosilyl-2-norbornene and the like are particularly preferable.

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

The Ziegler-Natta catalyst used in the present invention generally means T
Transition metals such as i, Zr, V, and Cr may be added as necessary with MgCl ₂ , Si.
A transition metal component supported on a carrier such as O ₂ or Al ₂ O ₃ , and A
It is a catalyst in which an organometallic component composed of an alkyl compound such as l, Mg and Li or a haloalkyl compound is combined. That is, as the transition metal compound, for example, a halide of a metal such as titanium, zirconium, vanadium or chromium is used, and a titanium or vanadium compound is particularly preferable. As the metal alkyl compound, for example, an alkyl compound or a haloalkyl compound of a metal such as aluminum, magnesium or lithium is used, and an organic aluminum compound is particularly preferable.

In the production of the graft copolymers (Si-EPs), first, the monomers (a) ethylene, (b) α-olefin or α-olefin and a non-conjugated diene, and (c) the general formula I and / or Alternatively, the compound represented by II is dissolved in a non-polar solvent such as n-hexane, n-heptane or cyclohexane and copolymerized using a Ziegler-Natta type catalyst. At this time, the amount of these monomers used can be changed depending on the content of the components derived from each monomer in the target copolymer.

The polymerization conditions are 0 to 100 ° C, preferably 20 to 90 ° C
At a temperature of 0 to 20 atmospheres, preferably 0 to 10 atmospheres.

In the polymerization, as a polymerization activator, for example, ethyl trichloroacetate, butyl trichloroacetate, a halogenated acetic acid ester such as dichloroacetic acid, 1,1,2,3,3-butyl pentachlorobutenoate, 1,1,2,3- A halogen-substituted butenoic acid ester such as ethyl tetrachlorobutenoate, and a halogen-containing organic compound such as α, α, α-trichlorotoluene and hexachlorobutadiene can be added.

Further, hydrogen gas, an alkylzinc compound or the like can be used as a molecular weight regulator of the copolymer at the time of polymerization.

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

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

In the copolymer, (c) the general formula I and / or
The content of the component derived from the silane compound represented by II 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 the content is too large, the degree of grafting will increase too much.
As a result, workability may deteriorate.

Next, when the reaction rate in the copolymerization reaction is sufficiently increased, (d) the compound of the general formula III is added to the system and stirred to allow the graft reaction to proceed, and then the polymerization reaction is stopped.

The amount of the compound of the general formula III added is (c) in the copolymer.
Relative to the content of (c), and it is preferably added in a ratio of 1/2 times or equimolar to the content of (c). In this case, the content of (c) was determined by infrared spectroscopic analysis of the copolymer before grafting. It can be quantified by analysis using absorption based on.

The grafting point in the graft reaction between the copolymer and the compound represented by the general formula III is the hydrogen atom of the hydroxyl group of the compound represented by the general formula III and the Si atom in the copolymer, in the present invention An example of the graft reaction is as follows.

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

Polyolefin thermoplastic resin and Si- in the present invention
The blending ratio with EPs is 15
~ 70 parts by weight, Si-EPs 30 to 85 parts by weight. If the amount of the polyolefin-based thermoplastic resin is less than 15% by weight, the fluidity of the obtained thermoplastic elastomer composition is extremely lowered, the moldability is deteriorated, and the polyolefin-based thermoplastic resin is
If it exceeds 70% by weight, the impact resistance of the obtained thermoplastic elastomer composition is lowered and the hardness becomes too high.

In the production of the thermoplastic elastomer composition of the present invention, an organic peroxide, a thermosetting resin or the like is used as a crosslinking agent.
Examples of the organic peroxide 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-butylperoxide, t-butylbenzoate, 1,1-
There are bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,4-dichlorobenzoyl peroxide and the like, and preferably 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,2'-bis (t-butylperoxy) -p-isopropylbenzene, etc. are used, and thermosetting resin Examples thereof include an alkylphenol formaldehyde resin, a melamine-formaldehyde condensate and a triazine-formaldehyde condensate, and an alkylphenol formaldehyde resin is preferably used.

The amount of the cross-linking agent, the polyolefin-based thermoplastic resin and
It is preferably used in the range of 0.1 to 10 parts by weight, more preferably 0.2 to 6 parts by weight, based on 100 parts by weight of the mixture of Si-EPs.
Parts by weight. If the amount of the cross-linking agent is too small, the cross-linking may be incomplete and the mechanical strength may be insufficient, and if it is too large, the cross-linking may result.

In the production of the thermoplastic elastomer composition of the present invention, in addition to the polyolefin-based thermoplastic resin, Si-EPs and the cross-linking agent, extender oil, a reinforcing agent, an anti-aging agent, a cross-linking aid and the like are used as necessary be able to.

Paraffin-based oils, naphthenic oils, silicone oils, etc. as extension oils, carbon black, white carbon, basic magnesium carbonate, as reinforcing agents,
Anti-aging agents such as activated calcium carbonate, phenol-based, imidazole-based, amine-based, etc.
As a crosslinking aid, sulfur, p-benzoquinone dioxime, p, p'-dibenzoylquinone dioxime, dinitrosobenzene, divinylbenzene, ethylene glycol dimethacrylate, triallyl isocyanurate, trimethylpropane trimethacrylate, liquid polybutadiene, polybutene , Polybutadiene resin, bismaleimide triazine resin and the like.

In the production of 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, propylene butene-1 copolymer, polyhexene-
An olefinic (co) polymer such as 1, poly-4-methylpentene-1 may be added within a range that does not impair the physical properties of the composition.

The thermoplastic elastomer composition of the present invention is preferably a polyolefin-based thermoplastic resin, Si-EPs and other compounding agents are crosslinked in the presence of shear stress, for example, Banbury mixer, kneader blender, continuous kneader, extrusion. Using a machine or the like, the temperature of the curing temperature of the cross-linking agent is 100 to 300 ° C, preferably 150 to 250 ° C, 0.5 to 30 minutes, preferably 1 to 20.
It is obtained by kneading separately.

〔Example〕

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

In this example, “parts” or “%” means “parts by weight” or “% by weight” unless otherwise specified. In the following examples, the content of the compound of formula I or II in the copolymer means the content in the copolymer sampled before grafting the compound of formula III. Infrared spectroscopic analysis was carried out on the film-shaped product, and the ethylene-α-olefin copolymer was previously prepared by using the general formula I or the general formula II.
For compounds and the obtained mixed sample subjected to infrared spectroscopy 1260 cm ^-1 vicinity of It was determined from a calibration curve prepared using peaks based on.

Example 1 A. Synthesis of Graft Copolymer 2 l of purified n-hexane was charged into a separable flask having a volume of 3 l and previously purged with nitrogen gas, and mixed with ethylene / propylene / hydrogen = 5/5/4 at room temperature. The gas was predissolved. Then 5-methyldichlorosilyl-2-norbornene 1.25 mmol, VOCl ₃ 0.5 mmol, AlEt _1.5 Cl _1.5
5 mmol was sequentially charged to start the polymerization reaction. During the polymerization reaction, a mixed gas of ethylene / propylene / hydrogen was fed in a gas phase, and the polymerization was continued at 20 ° C. with stirring. After 30 minutes, a small amount of the reaction solution was sampled for analysis of propylene content and content of the compound of general formula I or II, and then degassed silanol-modified silicone oil with both terminals (XF40-518, manufactured by Toshiba Silicon) Charge 2 ml,
Stop supplying mixed gas and purge with nitrogen gas 1
Stir for hours. Then dehydrated methanol as a polymerization terminator
The polymerization reaction was stopped by adding 5 ml.

In the solution of the graft copolymer thus obtained,
After a large excess of methanol was added to precipitate a polymer, it was dried with a roll heated to 100 ° C. The polymer yield was 58.3 g, and the content of 5-methyldichlorosilyl-2-norbornene was 0.45%.

B. Evaluation of physical properties Using the obtained graft copolymers (Si-EPs),
According to the formulation shown in the table, a kneader blender having an internal volume of 1 was kneaded at a set temperature of 170 ° C. for 20 minutes to obtain a thermoplastic elastomer composition. Then, injection molding was performed, and the obtained thermoplastic elastomer composition was subjected to a physical property test according to JIS K6301. The results are shown in Table 2, which shows excellent heat resistance.

Comparative Example 1 A composition was obtained and physical properties were evaluated in the same manner as in Example 1 except that ethylene propylene rubber (JSR02P manufactured by Japan Synthetic Rubber Co., Ltd.) was used instead of Si-EPs. The results are shown in Table 2, but the heat resistance was poor.

Example 2 A. Synthesis of Graft Copolymer Polymerization was carried out in the same manner as in Example 1A except that 5 ml of 5-ethylidene-2-norbornene was continuously charged during the polymerization reaction in Example 1A to obtain a graft copolymer. Obtained. The polymer yield was 47 g, the 5-methyldichlorosilyl-2-norbornene content was 0.47%, and the iodine value was 14.

B. Evaluation of physical properties Using the obtained graft copolymer (Si-EPs)
Physical properties were evaluated in the same manner as in Example 1B except that the compounding recipe shown in the table was used. The results are shown in Table 2, which shows excellent heat resistance.

Example 3 In Example 1B, 70 parts polypropylene, 30 Si-EPs
Physical properties were evaluated in the same manner as in Example 1B, except that the parts were changed. The results are shown in Table 2.

Comparative Examples 2 and 3 In Example 1B, the physical properties were evaluated in the same manner as in Example 1B except that the mixing ratio of polypropylene and Si-EPs was 80:20 (Comparative Example 2) and 10:90 (Comparative Example 3). Was done. The results are shown in Table 2. In Comparative Example 2, the amount of polypropylene used was large and the hardness was too high, and in Comparative Example 3, conversely, the amount of Si-EPs was large and the fluidity was extremely low. The moldability was poor.

〔The invention's effect〕

According to the present invention, by containing a specific modified ethylene-α-olefin- (non-conjugated diene) copolymer, a thermoplastic elastomer composition having higher heat resistance than a conventional polyolefin-based thermoplastic elastomer composition is obtained. be able to. These are useful as, for example, automobile boots, interior / exterior components, or interior / exterior components for home appliances.

Claims (2)

[Claims] 1. A thermoplastic polyolefin resin in an amount of 15 to 70 parts by weight, and (a) ethylene, (b) α-olefin or α.
- olefin and non-conjugated diene, (c) general formula _{I CH 2 = CHCH 2) n} -Si-R 1 mX 3-m (I) ( wherein, n an integer of 1 or more, m is integer of 0 to 2 , X is a chlorine atom or a bromine atom, R ¹ is a hydrogen atom or a carbon number of 1 to
5 means an alkyl group of 5) and / or the general formula 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, R ² , R ³ and R ⁴ are the same or different from each other, and each is a hydrogen atom or a carbon number of 1 to 1. A silane compound represented by
Copolymerization is carried out using a Natta catalyst, and (d) general formula III (In the formula, p and q are integers of 5 to 10,000, r and s are 0 or 1, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different from each other and have 1 to ¹⁰ carbon atoms. 6 is an alkyl group, a phenyl group or a vinyl group, and R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are the same or different from each other and mean a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). A modified ethylene-α-olefin copolymer obtained by grafting a compound and / or a modified ethylene-α-olefin-non-conjugated diene copolymer 30 to 85% by weight, and the copolymer is a crosslinking agent. A thermoplastic elastomer composition, wherein the thermoplastic elastomer composition is cross-linked. 2. The thermoplastic elastomer composition according to claim 1, wherein the crosslinking agent is an organic peroxide or a thermosetting resin.