JPH0641523B2 - Method for cross-linking cyclic olefin copolymers - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for crosslinking a cyclic olefin copolymer which can provide a cyclic olefin copolymer having excellent heat resistance, solvent resistance, strength and the like.

[Conventional technology]

The applicant has previously proposed a new substantially amorphous polymer having a cyclic olefin structure as shown in formula (2) in the polymer. Such a polymer has excellent transparency, heat resistance, chemical resistance, solvent resistance, electrical properties, mechanical strength, moldability, and dimensional stability, and can be used in various fields. But,
Depending on the application, heat resistance, solvent resistance, or mechanical strength may be required. Therefore, if these cyclic olefin polymers are modified to improve their properties, their fields of use will be further improved. spread.

[Problems to be solved by the invention]

The problem to be solved by the present invention is to provide a method for improving the heat resistance, chemical resistance, solvent resistance, mechanical properties and the like by modifying the above-mentioned cyclic olefin copolymer.

[Means for solving problems]

That is, the present invention is a method for crosslinking a cyclic olefin copolymer by sulfur, organic peroxide or radiation,
The cyclic olefin copolymer is a random copolymer containing the cyclic olefin of formula (1) and at least ethylene as a comonomer component, and the cyclic olefin has substantially the structure of formula (2) in the copolymer. And a method for cross-linking a cyclic olefin copolymer.

(In the formula, R ^{1 to} R ¹² are hydrogen or an alkyl group, and may be the same or different, and R ⁹ or R ¹⁰ and R ¹¹ or R ¹² may form a ring with each other. Is 0, 1 or 2, and when n is 2, two R ^{5 to} R ^{8 are}
May be the same or different. ) [Action and Effect] The copolymer used for crosslinking in the present invention contains the monomer of the formula (1) and ethylene as essential components. In the copolymer,
The molar ratio of ethylene / monomer component of formula (1) is 5/95 to 95 /
5, especially in the range of 40/60 to 90/10, and when α-olefin other than ethylene is coexistent, the total amount of these monomers / the molar ratio of the monomer components of the formula (1) is 5/9.
The range of 5 to 95/5, especially 30/70 to 90/10 is preferable. Further, in the present invention, the monomer component of formula (1) is not limited to a single component, and it goes without saying that a plurality of components represented by formula (1) may be mixed.

Specific examples of the monomer component represented by the formula (1) include the following, but the examples shown here are extremely limited and are those represented by the formula (1). Anything can be the monomer component of the present invention.

Among these, n = 0 or 1 in the formula (1), that is, the formulas (3), (4), The monomer component represented by is preferable in terms of availability of the monomer or easy synthesis of the monomer. Furthermore, the one having n = 1 is more preferable than the one having n = 0 because the heat resistance is excellent.

Other α-olefins which can be copolymerized with the monomer component of formula (1) and ethylene are α-olefins having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, such as propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-
Dodecene, 1-tetradecene, 1-hexadecene, 1-
Icosene etc. can be illustrated.

Cyclic olefins other than the formula (1), which is another component that can be copolymerized with the monomer component of the formula (1), and styrenes include, for example, cyclopentene, cyclohexene, and 3,4.
-Dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene,
Examples thereof include styrene, α-methylstyrene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene and the like.
The copolymerizable polyene component includes 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6- Octadiene, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene,
5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, divinylbenzene, 1,5
Non-conjugated dienes such as hexadiene, norbornadiene, 2,3-diisopropylidene-5-norbornene, 2
-Ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-
Trienes such as octatriene and 1,4,9-decatriene can be exemplified as typical examples. Polyene components of particular interest are dicyclopentadiene, 5-vinyl norbornene and 5-ethylidene-2-norbornene.

In addition to the monomer components described above, other copolymerizable monomer components may be contained in the copolymer in a small amount within the range not impairing the object of the present invention.

The copolymer is composed of the monomer component of the formula (1) and ethylene described above in detail, and optionally other α-olefin and / or
Alternatively, it is produced by polymerizing a cyclic olefin by using a well-known Ziegler catalyst, particularly a vanadium-based Ziegler catalyst. More specifically, a prior patent application by the applicant (for example, Japanese Patent Application No. 60-110545 or 60-113074).
Is disclosed in. A characteristic of the polymer is that the monomer component of the formula (1) mainly has a structure represented by the formula (2) in the polymer, whereby the iodine value of the copolymer does not include the polyene component. Usually 5 or less but 1
When the polyene component is included, it is in the range of 2 to 50, and most of the range is 5 to 30. Also, taking the structure of formula (2) is ¹³ C
-It is also supported by NMR.

By adopting this structure, the copolymer is chemically stable, has excellent water resistance and chemical resistance to alkalis and acids, and further has excellent solvent resistance, heat resistance and weather resistance. It also has an extremely low water content.

Furthermore, many of the copolymers of the raw material of the present invention are low crystalline, and most of them are also amorphous, and melting points are not observed.

Various known methods can be used to crosslink the above-mentioned copolymer, but a method in which sulfur or an organic peroxide is blended and crosslinked, or a method in which radiation is irradiated to crosslink is particularly preferable.

Sulfur Crosslinking When the copolymer of the present invention is crosslinked with sulfur, a sulfur compound, optionally a vulcanization accelerator, and a vulcanization acceleration aid are added to the copolymer and heated to cause a crosslinking reaction. Excuse me. The blending amount of the sulfur-based compound is not particularly limited, but 0.1 to 10 relative to 100 parts by weight of the copolymer from the viewpoint of efficiently performing the crosslinking reaction and improving the physical properties of the resulting crosslinked product and economical efficiency. It is used in an amount of 0.3 to 5 parts by weight, preferably 0.1 to 20 parts by weight, and more preferably 0.2 to 10 parts by weight when a vulcanization accelerator or vulcanization accelerator auxiliary is used in combination. .

Since a copolymer crosslinked with sulfur must have an unsaturated bond, it is preferable to use a copolymer having a polyene component as a comonomer component and an iodine value in the range of 5 to 50. is there.

Various known sulfur compounds can be used to cause the crosslinking reaction, and examples thereof include sulfur, sulfur monochloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, and tetramethyl thiuramdis. Examples include rufuid and selenium dimethyldithiocarbamate. Various vulcanization accelerators can be used, and N-cyclohexyl-2-benzothiazole-sulfenamide, N-
Oxydiethylene-2-benzothiazole-sulfenamide, N, N-diisopropyl-2-benzothiazole-sulfenamide, 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl) -4-morpholinothio) benzothiazole, benzothiazyl-disulfide, and other thiazoles; diphenylenyl guanidine, triphenyl guanidine, diaorthosyl guanidine, orthosanthryl biguanide, diphenyl guanidine phthalate, and other guanidines; acetaldehyde-aniline reaction product Butyraldehyde-aniline condensate; hexamethylenetetramine, aldehyde amine such as acetaldehyde ammonia, or aldehyde-ammonia system;
Imidazoline compounds such as 2-mercaptoimidazoline; thiourea compounds such as thiocarbanilide, diethyl thiourea dibutyl thiourea, trimethyl thiourea, and diorthoritol thiourea; tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetraethyl thiuramdis Thiurams such as rufuid, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide; zinc dimethyldithiocarbamate,
Dithioate salts such as zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, and tellurium diethyldithiocarbamate; Zanthate such as zinc dibutyl xanthate; and the like.

As the vulcanization accelerator, zinc oxide, activated zinc white, zinc carbonate, complex zinc white, magnesium oxide, litharge, red lead,
Examples thereof include metal oxides such as basic lead carbonate, fatty acids such as stearic acid, oleic acid, lauric acid and lead stearate, organic amines and glycols such as triethanolamine and diethylene glycol.

Crosslinking with an organic peroxide is preferable when the copolymer is in the form of a saturated polymer, that is, when the copolymer does not contain a polyene component as a comonomer and the iodine value is 5 or less.

For the crosslinking with an organic peroxide, the usual crosslinking method with an organic peroxide, which is applied with polyolefin, can be directly applied. That is, an organic peroxide such as dicumyl peroxide is added to the copolymer of the present invention, and a crosslinking aid such as triallyl cyanurate is added, if necessary, and heating and crosslinking are performed. The blending ratio of the organic peroxide is not particularly limited, but for the same reason as the above blending ratio of sulfur, about 0.02 to 10 parts by weight, preferably 0.0 per 100 parts by weight of the copolymer.
5 to 5 parts by weight, and when a crosslinking aid is used in combination, the amount of the aid is 0.02 to 8 parts by weight, preferably 0.03 to 3 parts by weight.

Examples of the organic peroxide include 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, 1,1-di (t-butylperoxy) 3,3,5-trimethylcyclohexane,
n-Butyl-4,4-di (t-butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, t
-Butylperoxycumene, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy)
Hexin-3 and the like can be mentioned as one example, but these are extremely limited examples, and more detailed examples of organic peroxides can be found in "Crosslinking Agent Handbook" P520-published by Taisei Co., Ltd.
Shown at 535. The cross-linking aid is used to increase the cross-linking efficiency by the organic peroxide, and a compound having sulfur or a polyfunctional double bond is used. More specifically, in addition to sulfur, metaphenylene bismaleimide, quinone dioxime , 1,
2-polybutadiene, triallyl cyanurate, diallyl phthalate, ethylene glycol dimethacrylate,
Examples include trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, triallyl isocyanurate and the like.

The above-mentioned sulfur crosslinking is similar, but the crosslinking is usually 100 to 250.
C., preferably 120 to 200.degree. C., and crosslinking time is usually 10 minutes to 60 minutes, preferably 20 to 40 minutes. Particularly when the crosslinking is carried out with an organic peroxide, the crosslinking time is preferably about 4 times the half-life of the organic peroxide.

Crosslinking by radiation The copolymers of the invention also crosslink by radiation such as electron beams. In carrying out radiation crosslinking, diallyl sebacate, triallyl cyanurate, N, N'-hexamethylenebismethacrylamide, etc. may be blended in order to increase the crosslinking efficiency. Radiation dose is about 10-50Mr
Although it is ad, there is no particular problem even if it deviates from this range as long as the properties of the obtained crosslinked product do not deviate from the target range.

As the radiation, α-ray, β-ray, γ-ray or electron beam accelerator from a radioisotope, for example, Vourne-de-Glaquer type electron beam accelerator, Kotskcroft, Walton type electron beam accelerator, insulation transformer type electron beam accelerator, transformer type Gas (oil)
Ionizing radiation such as an electron beam from an insulation type electron beam accelerator, a cold cathode impact voltage type electron beam accelerator, a linear filament type electron beam accelerator or the like is preferable. However, X-rays can also be used.

When the copolymer of the present invention is cross-linked by radiation, a predetermined shape is given in advance by a method such as injection molding, extrusion molding, vacuum molding or compression molding, and then irradiation is performed, or if possible, irradiation is performed simultaneously with molding. A method can also be adopted.

The cyclic olefin copolymer cross-linked product obtained as described above contains, if necessary, an activator, a dispersant, a filler, a plasticizer, a tackifier, a colorant, a foaming agent, a foaming aid, a lubricant, and an aging agent. An inhibitor and other additives can be used in combination.

As the filler, inorganic fillers such as carbon black, white carbon (silicic acid compound), calcium carbonate, talc and clay; high styrene resin, coumarone indene resin, phenol resin, lignin, modified melamine resin,
Mention may be made of organic fillers such as petroleum resins. Of these, an inorganic filler is particularly preferably used.

Examples of the softening agent include petroleum-based softening agents such as process oil, lubricating oil, paraffin, fluid paraffin, petroleum asphalt, and petrolatum; coal tar-based softening agents such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil,
Fatty oil type softeners such as coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax and lanolin; fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate and zinc laurate; petroleum Synthetic high molecular substances such as resins;

As a plasticizer, a phthalic acid ester type, an adipic acid ester type, a sebacic acid ester type, a phosphoric acid type, etc. Is a foaming agent such as inorganic and organic pigments,
As a foaming aid such as sodium bicarbonate, ammonium carbonate, N, N'-dinitrosopentamethylenetetramine, azocarbonamide, azobisisobutyronitrile, benzenesulfonylhydrazide, toluenesulfonylhydrazide, calcium amide, paratoluenesulfonylazide Can use salicylic acid, phthalic acid, urea and the like.

In addition, a known method using an open roll mill, a Banbury mixer, a kneader, a single-screw or twin-screw extruder, etc. can be adopted for the production of the compound.

Depending on the case, the copolymer may be dissolved in a solvent and necessary additives may be mixed.

The cross-linked product obtained by the method of the present invention has excellent solvent resistance, heat resistance, mechanical strength, etc., and can be applied to electric circuit boards (for high frequencies), wire coatings, vibration damping materials, foods for microwave ovens, etc. .

〔Example〕

Example 1 Using a 2-glass polymerization vessel equipped with a stirring blade, ethylene and 2-methyl-1,4,5,8-dimethano-1,2,3,4,4 were continuously added.
Copolymerization reaction of a, 5,8,8a, -octahydronaphthalene (hereinafter abbreviated as M-DMON) was performed. That is, M-DMON concentration in the polymerization vessel from the upper part of the polymerization vessel was 60 g / M-
The toluene solution of DMON is 0.9 per hour, the vanadium concentration in the polymerization vessel is 0.5 mmol /, the toluene solution of VO (OC ₂ H ₅ ) Cl is 0.7 per hour, and the aluminum concentration in the polymerization vessel is 3 mmol / Ethyl aluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 Cl _1.5 ) in toluene solution at 0.
It was continuously fed into each polymerizer at a rate of 4. On the other hand, the polymerization solution is continuously withdrawn from the lower part of the polymerization vessel so that the polymerization solution becomes 1 in the polymerization vessel. Further, ethylene is supplied at a rate of 40 / hour and nitrogen is supplied at a rate of 80 / hour from the upper portion of the polymerization vessel. The copolymerization reaction was performed at a temperature of 10 ° C. by using a refrigerant. A small amount of methanol was added to the polymer polymerization liquid extracted from the lower part of the polymerization vessel to stop the polymerization reaction, and the mixture was poured into a large amount of isopropyl alcohol to precipitate the produced copolymer, which was washed with isopropyl alcohol. At this time, the copolymer was obtained at a rate of 30 g / h.

This copolymer was vacuum dried at 160 ° C. overnight. The ethylene composition of the copolymer by ¹³ C-NMR analysis was 66 mol%, and the intrinsic viscosity [η] measured at 135 ° C in decalin was 1.20d.
l / g, Dynamic Mechanical Analyser (DM
The glass transition temperature according to A) is 121 ° C., and the copolymer 100
The iodine value was 0.5 as measured by the amount of iodine monochloride consumed per gram (g).

To 100 g of this polymer, 5 g of zinc oxide, 1 g of stearic acid, and 3.0 g of P, P'-dibenzoylquinonedioxime were mixed and mixed at 200 ° C. by a kneader. After crushing the mixture, 1.0 g of dicumyl peroxide was made into a benzene solution and impregnated into the mixture. After removing benzene with a vacuum dryer, it was heat-crosslinked with a press molding machine at 160 ° C. for 20 minutes. The obtained sheet had a flexural modulus of 2.0 × 10 ⁴ kg / cm ² measured according to ASTM D 790 and a heat distortion temperature of 120 ° C. according to ASTM D 648 (load 4.6 kg).

Further, the molded plate having a groove having a width of 2 mm and a depth of 0.5 mm was immersed in a cyclohexane solution for 10 hours, and the solvent resistance judged from the change in the groove shape was extremely good.

Example 2 In Example 1, 5 ethylidene-2-norbornene (ENB)
The same procedure was carried out except that the polymerization was performed by adding. The results are shown in Table 1.
It was shown to.

Example 3 In Example 1, 1,4,5,8-dimethano-instead of M-DMON
1,2,3,4,4a, 5,8,8a, -octahydronaphthalene (DMON)
The same was done except that was used. The results are shown in Table 1.

Example 4 The same procedure as in Example 3 was carried out except that dicyclopentadiene (DCPD) was added and polymerization was performed. The results are shown in Table 1.

Examples 5 and 6 In Example 1, 6-ethylbicyclo [221] hept-2ene was used in place of M-DMON, and 1,4 hexadiene (1,4HD) or 5-ethylidene-2-norbornene was used. I went in the same way except I was there. The results are shown in Table 1.

Comparative Examples 1 to 6 The polymers of Examples 1 to 6 were directly press-molded and measured in the same manner as in Examples.

Example 7 100 g of the polymer of Example 2 was mixed with 5 g of zinc white and stearic acid.
1.5 g, 2-mercaptobenzothiazole 0.5 g, tetramethyl thiuram monosulfide 1.5 g and sulfur 1.0 g were added and mixed by a kneader. This mixture was press-molded at 180 ° C. for 10 minutes for crosslinking.

As a result, the flexural modulus was 2.1 × 10 ⁴ kg / cm ² , the heat distortion temperature was 123 ° C., and the solvent resistance was good.

Example 8 The polymer of Example 6 was crosslinked as in Example 7. As a result, the flexural modulus was 1.7 × 10 ⁴ kg / cm ² , and the heat distortion temperature was 75 ° C.
And the solvent resistance was good.

Example 9 0.1 wt% of triallyl cyanurate was added to the polymer of Example 1 to form a sheet having a thickness of 0.5 mm, and the sheet was irradiated with 15 Mrad of γ rays. As a result, the flexural modulus of the sheet after irradiation is 1.
8 × 10 ⁴ kg / cm ² , heat distortion temperature was 115 ° C., and solvent resistance was good.

Example 10 Pentacyclo (6,5,1,1,0,0) pentadecene-4 represented by the following structural formula in place of M-DMON in Example 1
The same procedure as in Example 1 was performed except that was used.

The results are shown in Table 1.

Example 11 In Example 1, hexacyclo (6,6,1,1,1,0,0) heptadecene represented by the following structural formula was used instead of M-DMON.
Example 1 was repeated except that 4 was used.

The results are shown in Table 1.

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Claims (1)

[Claims] 1. A method for crosslinking a cyclic olefin copolymer with sulfur, an organic peroxide or radiation, the cyclic olefin copolymer containing a cyclic olefin of formula (1) and at least ethylene as a comonomer component. A method for crosslinking a cyclic olefin copolymer, which is a random copolymer, and the cyclic olefin has substantially the structure of formula (2) in the copolymer. (In the formula, R ^{1 to} R ¹² are hydrogen or an alkyl group, and may be the same or different, and R ⁹ or R ¹⁰ and R ¹¹ or R ¹² may form a ring with each other. Is 0, 1 or 2, and when n is 2, two R ^{5 to} R ^{8 are}
May be the same or different. )