JPS61192709A - Production of crosslinked olefin polymer - Google Patents

Abstract

PURPOSE:To improve the tensile strength and impact strength of a crosslinked product by a process applicable to a wide variety of olefin (co)polymers, by grafting a specified silane compound to an olefin polymer and crosslinking the grafted polymer in the presence of a silanol condensation catalyst in an aqueous atmosphere. CONSTITUTION:A silane compound of the formula [wherein Y is an alkylidenenorbornyl group and R<1> is a 1-8 C (substituted) monovalent hydrocarbon group, R<2> is a 1-4 C alkyl group, a is 1-3, b is a number of 0-2 which provides a+b=1-3] is grafted to an olefin polymer, and the grafted polymer is crosslinked in the presence of a silanol condensation catalyst (e.g., dibutyltin dilaurate) in an aqueous atmosphere. As said silane compound, ethylidenenorbornyltrimethoxysilane is preferable. In crosslinking said grafted polymer in an aqueous atmosphere, it is preferable that the grafted polymer containing a silanol condensation catalyst is molded and then brought into contact with water or steam at about 80-120 deg.C for about 30-80hr.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a crosslinked product obtained from an olefin polymer, which is an olefin rubber and/or an olefin resin.

BACKGROUND ART In recent years, as a method for crosslinking synthetic resins, for example, (all ethylene polyolefins are grafted with silanes such as vinyltriethoxysilane and vinyltrimethoxysilane),
The polyolefin is then crosslinked by exposing this product to water in the presence of a silanol condensation catalyst to obtain a crosslinked olefin (co)polymer having crack resistance, organic solvent resistance, and high tensile strength. 4B-1711
(No. 2) or (2) A composition obtained by blending an ethylene resin (B) and an ethylene-α-olefin copolymer rubber (C) with a modified propylene resin (A) grafted with an ethylenically unsaturated silane compound. A method has been proposed (Japanese Unexamined Patent Publication No. 115351/1983) for producing a crosslinked propylene resin having excellent impact strength and rigidity by exposing the propylene resin to water in the presence of a silanol condensation catalyst to crosslink it.

Problems to be Solved by the Invention However, although method a1 is effective as a crosslinking method for ethylene resins, it is still insufficient in terms of impact strength, rigidity, etc. when applied to propylene resins. Furthermore, in the method (b1), a specific graft-modified propylene resin must be used in combination with other specific resins, and there are limitations on the types of resins that can be used.

The present invention was made against the background of these conventional technical problems, and is an olefin-based (co)polymer crosslinked product that can be applied to a wide range of resins and has excellent tensile strength, impact strength, etc. The purpose is to provide a manufacturing method.

Means for Solving the Problems The present inventors have made extensive studies to solve the above-mentioned conventional technical problems. As a result, the present inventors found that when a new specific silane compound is adopted in the above-mentioned crosslinking method, a wide range of olefin-based ( The present invention was achieved based on the discovery that the present invention can be applied to co)polymers and that the resulting crosslinked product has excellent physical properties such as tensile strength and impact strength.

That is, the present invention provides an olefin polymer having the following general formula (1
) A method for producing a crosslinked olefin polymer is provided, which comprises grafting a silane compound represented by the following formula, and then crosslinking the product in a water atmosphere in the presence of a silanol condensation catalyst.

Ys (R')h S t (OR")4-s
4 (1) (wherein, Y is an alkylidene norbornyl group, R1 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, R8 is an alkyl group having 1 to 4 carbon atoms, and a is 1
b is an integer of 0 to 2 such that a+b is 1 to 3. ) In the present invention, the olefin polymer is an olefin rubber and/or an olefin resin.

Here, as the olefin rubber, ordinary ethylene-
Propylene copolymer rubber (EPM), ethylene-propylene-diolefin copolymer rubber (EPDM), butyl rubber (IIR), halogenated butyl rubber (X-IIR),
Examples include acrylic rubber (ACM diacrylic acid-2-chloroethyl vinyl ether copolymer rubber, ANM diacrylic acid-acrylonitrile copolymer rubber), chlorosulfonated polyethylene rubber (C3M), fluororubber (FKM), and the like.

In addition, olefin resins include homopolymers of olefin monomers such as polyethylene and polypropylene,
Alternatively, copolymers obtained by copolymerizing this with about 30% by weight or less of other olefin monomers, and mixtures thereof can be mentioned. The Mooney viscosity (M L + -4, 100°C) of these olefin rubbers is not particularly limited, but is preferably about 20 to 150, more preferably about 30 to 90. Further, the melt viscosity of the olefin resin is about 5 to 40, preferably about 10 to 30 in terms of melt flow rate (g/10 minutes, 190°C) for polyethylene resin. For polyethylene resin, the melt flow rate (g/10 min, 230°C) is 0.0.
It is about 1 to 30, preferably about 0.1 to 20.

In the present invention, the silane compound to be grafted onto the olefinic polymer has the following formula: , preferably an ethylidenenorbornyl group, R1 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, Rt
is an alkyl group having 1 to 4 carbon atoms, a is an integer of 1 to 3, and b is an integer of 0 to 2 such that a+b is 1 to 3. ) is a specific silane compound represented by Here, below the ethylidene norbornyl group C, which is a preferred embodiment of Y, rE
"NB group") refers to the following (i) and/or (i
It has a structure like i).

Specific examples of such silane compounds include ENB) rimethoxysilane, ENB l-liethoxysilane, EN
B Methyldimethoxysilane, ENB Methyljethoxysilane, ENB Ethyldimethoxysilane, ENB Ethyldimethoxysilane, ENB Phenyldimethoxysilane, ENB
Examples include NB phenyldiethoxysilane.

In the case of such a silane compound, such as ethylidenenorbornyltrimethoxysilane, 5-ethylidenebicyclo(2°2.1)hept-2 is added to a flask equipped with a dropping funnel.
- 100 parts by weight of ene and 0.02 parts of chloroplatinic acid as a catalyst.
parts by weight, heated to 60°C, and then slowly dropped 90 parts by weight of trimethoxysilane from the dropping funnel.
The addition reaction was carried out for 20 hours while keeping the liquid temperature at 60°C.
The product can be produced by stripping under reduced pressure (for example, 20 ssHg) to remove unreacted substances, and then distilling the product.

In the case of ENB phenyldimethoxysilane, 5-ethylidenebicyclo(2
,2,1) 140 parts by weight of hept-2-ene and 0.02 parts by weight of chloroplatinic acid as a catalyst were charged, heated to 60°C, and then 18 parts by weight of phenylmethoxysilane was added from the dropping funnel.
0 parts by weight was slowly added dropwise, and the addition reaction was carried out for 20 hours while keeping the liquid temperature at 80°C.
) After stripping to remove unreacted substances, it can be produced by distillation.

The proportion of the silane compound represented by the general formula (R) used is:
The amount is 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight. If the weight of the silane compound is less than about 0.1 part by weight, the crosslinking effect will be poor, while if it exceeds about 30 parts by weight, not only will the crosslinking effect not improve proportionally, but the impact resistance and tensile strength of the crosslinked product will be reduced. It is not preferable because it may deteriorate various physical properties such as.

In the present invention, the means for grafting the silane compound onto the olefin polymer is not particularly limited. Grafting here refers in a broad sense to introducing a functional group into the main chain of the polymer.

Therefore, as a means for grafting a silane compound to an olefin polymer in the present invention, for example, (1) Preferably a radical generator is used to mainly cause cleavage of the main chain. Either mix a silane compound and a radical generator and heat it to a temperature above the decomposition temperature of the radical generator, or mix the silane compound and a resin vulcanizing agent with olefin rubber and heat it to a temperature at which the resin vulcanizer effectively acts. (2) Mixing a silane compound and a sulfur vulcanizing agent with olefin rubber and heating the mixture to a temperature at which the sulfur vulcanizing agent is effective.

■When using a radical generator, compounds described in Japanese Patent Publication No. 1711/1988 can be used, preferably dicumyl peroxide, t-butyl peroxide, tate, benzoyl oxide, azobisisobutyronitrile, methyl azoisobutyrate, and the like.

At this time, based on 100 parts by weight of the olefin polymer, 0.1 to 30 parts by weight of the silane compound and 0.1 to 30 parts by weight of the radical generator. O1 to 3.0 parts by weight, preferably 0.05 to 1.0
Parts by weight are mixed and heated to a temperature above the radical generation temperature, for example, 80
The graft reaction may be caused at a temperature of -300°C, preferably 100-250°C.

When a resin vulcanizing agent is used, examples of the resin vulcanizing agent include methylolated alkylphenol formaldehyde resins and brominated alkylphenol formaldehyde resins. At this time, 0.1 part of the silane compound is added to 10 parts by weight of the olefin rubber.
~3o! ! and 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, of a resin vulcanizing agent, and using the kneading means or molding means at a temperature at which the resin vulcanizing agent effectively acts, e.g. 100-250t, preferably 150-20
A silane compound may be introduced into the main chain of the olefin rubber by heating it to a temperature of 0°C.

Furthermore, (1) When using a sulfur vulcanizing agent, the sulfur vulcanizing agent has, for example, sulfur as a main component, and dithiocarbamate 11! Examples include common sulfur vulcanization systems containing vulcanization accelerators such as thiurams, thiurams, or thiazoles.

At this time, 0.1 to 30 parts by weight of the silane compound and 0.1 part by weight of the sulfur vulcanizing agent per 100 parts by weight of the olefin rubber.
~5 parts by weight, preferably 0.5 to 3 parts by weight are mixed, and the temperature at which the sulfur vulcanizing agent acts effectively, for example, 100 to 200 °C, preferably 130 to 180 °C, is mixed using the kneading means or molding means. The silane compound may be introduced into the main chain of the olefin rubber by heating it to a temperature of .degree.

In this way, when using resin vulcanizing agents or sulfur vulcanizing agents, these vulcanizing agents act on the double bonds present in the main chain of the olefin rubber, generating radicals, which The silane compound is introduced into the main chain of the olefin rubber directly or indirectly through these vulcanizing agents.

As described above, in the present invention, a product is obtained by grafting the silane compound represented by the general formula (I) onto an olefin polymer. Crosslink.

In this case, the silanol condensation catalyst is
Examples include those described in Publication No. B-1711, and preferred examples include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, etc., which may be blended before molding the product, or dissolved or dispersed. It is used by applying or impregnating molded objects as a liquid.

The amount of these silanol condensation catalysts used is as follows:
0.01 to 10 parts by weight, preferably 0
．． 05 to 5 parts by weight.

In addition, when crosslinking in a water atmosphere, after molding the product containing the silanol condensation catalyst, the molded product is soaked in water or steam at a temperature of about 50 to 150°C, preferably about 80 to 120°C, for about 10 to 100 hours. , preferably 3
It is preferable to contact for 0 to 80 hours.

Function The present invention aims at application to a wide range of olefin polymers and improvement of various physical properties of the polymers by using a silane compound containing an alkylidenenornorbornyl group.

Effects of the Invention As described above, according to the present invention, any olefin polymer can be crosslinked by employing a new silane compound containing an alkylidenenornorbornyl group in place of a conventionally known silane compound. This makes it possible to provide a crosslinked product with excellent physical properties such as impact resistance, tensile strength, and heat resistance.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. In the examples, parts and % are based on weight unless otherwise specified.

Example 1, Comparative Example I JSRButyl 268 (manufactured by Japan Synthetic Rubber Special Co., Ltd., butyl rubber, degree of unsaturation 1.5% > 100 parts, ethylidenenorbornyltriethoxysilane 3 parts and Tackirol 250-I (manufactured by Sumitomo Chemical Co., Ltd., bromo rubber) 1 part of methylalkylphenol formaldehyde resin) was kneaded for 5 minutes at 170°C using a Banbury mixer,
A silane compound was grafted.

50 parts of show black (A, A, manufactured by Chemical Co., Ltd., carbon blank) and 2.5 parts of zinc oxide were blended into the grafted butyl rubber using a Banbury mixer.

Next, 0.2 part of dibutyltin dilaurate was kneaded into this mixture using a roll, and then test pieces for each test were formed and immersed in hot water at 100°C for 50 hours to obtain a crosslinked product (
Example 1).

A physical test was conducted using the obtained crosslinked product according to JIS K6301. The results are shown in Table 1.

As a comparative example, a crosslinked product was obtained in the same manner as in Example 1 except that vinyltrimethoxysilane was used instead of the silane compound (Comparative Example 1).

The results are shown in Table 1.

Table 1 shows that ethylidenenorbornyltriethoxysilane has superior grafting reactivity to butyl rubber compared to ordinary vinyltriethoxysilane, and the resulting crosslinked product has superior mechanical strength and heat resistance. I understand.

Table 1 Example 2, Comparative Example 2 100 parts of JSREP43 (ethylene-propylene-diene copolymer rubber manufactured by Nippon Synthetic Rubber), 3 parts of ethylidenenorbornyltrimethoxysilane and 0.15 parts of dicumyl peroxide were mixed in a Banbury mixer. - using 1
The mixture was kneaded at 75° C. for 5 minutes to graft the silane compound.

This grafted ethylene-propylene-diene copolymer rubber was added to Showblack (A) using a Banbury mixer.
, A, Carbon Blank (manufactured by Chemical Co., Ltd.), 50 parts of zinc oxide, and 1 part of stearic acid were blended.

Next, 0.2 part of dibutyltin dilaurate was kneaded into this mixture using a roll, and then test pieces for each test were formed and immersed in hot water at 100°C for 50 hours to obtain a crosslinked product (Example 2). .

A physical test was conducted using the obtained crosslinked product according to JIS K6301. The results are shown in Table 2.

As a comparative example, a crosslinked product was obtained in the same manner as in Example 2 except that vinyltrimethoxysilane was used instead of the silane compound (Comparative Example 2).

The results are shown in Table 2.

Table 2 shows that ethylidenenorbornyltrimethoxysilane has superior grafting reactivity to ethylene-propylene-diene copolymer rubber compared to ordinary vinyltrimethoxysilane, and the resulting crosslinked product has excellent mechanical strength and heat resistance. It turns out that he has excellent sex.

Table 2 Example 3, Comparative Example 3 100 parts of granular high-density polyethylene with a melt flow rate of 20 (g/10 minutes, 190°C), 3 parts of ethylidenenorbornylmethoxysilane and 0.15 parts of dicumyl peroxide were added. The mixture was mixed and melt-kneaded at 200° C. using an extruder with a diameter of 65 mm and diameter of 25 mm to graft a silane compound.

After kneading 0.2 parts of dibutyltin dilaurate into this grafted polyethylene using a roll, test pieces for each test were formed and immersed in hot water at 100°C for 50 hours to obtain a crosslinked product. Example 3) Various physical tests were conducted using the obtained crosslinked product. The results are shown in Table 3.

As a comparative example, a crosslinked product was obtained in the same manner as in Example 3 except that vinyltrimethoxysilane was used instead of the silane compound (Comparative Example 3).

The results are shown in Table 3.

From Table 3, it can be seen that ethylidenenorbornyltrimethoxysilane has superior graft reactivity to polyethylene compared to ordinary vinyltrimethoxysilane, and as a result has a large effect on improving the physical properties of polyethylene.

Table 3 Example 4, Comparative Example 4 Melt flow rate 0.3 (g/10 minutes, 230°C)
100 parts of polypropylene homopolymer of
Melt-knead at 200°C using a /D25 extruder,
A silane compound was grafted.

After kneading 0.2 parts of dibutyltin dilaurate into this grafted polyethylene using a roll, test pieces for each test were formed and immersed in hot water at 100°C for 50 hours to obtain a crosslinked product. Example 4) Various physical tests were conducted using the obtained crosslinked product. The results are shown in Table 4.

As a comparative example, a crosslinked product was obtained in the same manner as in Example 4 except that vinyltrimethoxysilane was used instead of the silane compound (Comparative Example 4).

The results are shown in Table 4.

From Table 4, it can be seen that ethylidene norbornylphenyl dimethoxysilane has superior grafting reactivity to polypropylene compared to ordinary vinyltrimethoxysilane, and as a result has a large effect on improving the physical properties of polypropylene.

Table 4 Example 5, Comparative Example 5 100 parts of JSREP 43 (manufactured by Japan Synthetic Rubber ■, ethylene-propylene-diene copolymer rubber), 3 parts of ethylidenenorbornyltriethoxysilane, 0.2 parts of tetramethylthiuram monosulfide , 0.07 part of mercaptobenzothiazole and 0.2 part of sulfur were kneaded at 160° C. for 5 minutes using a Banbury mixer to graft the silane compound.

This grafted ethylene-propylene-diene copolymer rubber was added to Showblack (A) using a Banbury mixer.
, A, manufactured by Chemical Co., Ltd., 50 parts of carbon black), 5 parts of zinc oxide, and 5 parts of stearic acid were blended.

Next, 0.2 parts of dibutyltin dilaurate was kneaded into this mixture using a roll, and then test pieces for each test were formed and immersed in hot water at 100°C for 50 hours to obtain a crosslinked product (Example 5).

A physical test was conducted using the obtained crosslinked product according to JIS K6301. The results are shown in Table 1.

As a comparative example, a crosslinked product was obtained in the same manner as in Example 5 except that vinyltrimethoxysilane was used instead of the silane compound (Comparative Example 5).

The results are shown in Table 5.

Table 5 shows that ethylidenenorbornyltriethoxysilane has superior grafting reactivity to ethylene-propylene-diene copolymer rubber compared to ordinary vinyltriethoxysilane, and has improved mechanical strength and heat resistance of the resulting crosslinked product. It can be seen that it is excellent.

Table 5

Claims (2)

[Claims] (1) Production of a crosslinked olefin polymer, which is characterized by grafting a silane compound represented by the following general formula (I) onto an olefin polymer, and then crosslinking it in a water atmosphere in the presence of a silanol condensation catalyst. Method. Y_a(R^1)_bSi(OR^2)_4_-_a_
-_b(I) (wherein, Y is an alkylidene norbornyl group, R^1 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and R^2 is an alkyl group having 1 to 4 carbon atoms. group, a is an integer of 1 to 3, b is 0 to 2 such that a+b is 1 to 3
is an integer. ) (2) The method for producing a crosslinked olefin polymer according to claim 1, wherein the alkylidene norbornyl group is an ethylidene norbornyl group.