JPH0649810B2 - Rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention In the present invention, a polar polymer is contained in a rubber-like polymer (hereinafter sometimes abbreviated as EP rubber) composed of ethylene and α-olefin and / or non-conjugated diene. The present invention relates to a rubber composition containing a cyclopentadiene resin to improve roll adhesion and tackiness in an unvulcanized state without lowering the vulcanization rate and physical properties of the EP rubber in the vulcanized state.

Problems to be Solved by Conventional Technology and Invention EP rubber has excellent ozone resistance, weather resistance, heat resistance, etc., and is widely used in automobile parts, building materials, and various industrial rubber products. However, there is a drawback in that the roll wrapping property and the tackiness in the unvulcanized state are inferior, which causes troubles during the processing of the product.

The roll wrapping property here means EP using a roll mill.
It is the wrapping property around a roll mill at the time of mixing a system rubber and various rubber compounding agents, and if this is insufficient, it takes a lot of labor and time to mix the rubber compounding agents.

Adhesiveness is the property of joining rubber when contacting rubber or rubber and other substances under appropriate pressure.For example, in a tire or a tube, rubber is joined to form a shape, Vulcanization is performed in this state to obtain a product, but if the adhesive strength of the unvulcanized rubber is insufficient, it will be difficult to vulcanize while maintaining the required shape, and also the adhesive force on the contact surface after vulcanization There is a problem that it is lowered and peeling is easy.

Various tackifiers and processing aids have been proposed so far in order to compensate for the above-mentioned drawbacks, but none of them have satisfactory performance. For example, coumarone resin, which is a known tackifying resin, terpene resin, little improvement in tackiness is observed in fatty petroleum resin, and when a developing oil is used, the tackiness is improved to some extent if used in a large amount, There is a drawback that the physical properties of the rubber composition after vulcanization deteriorate. Furthermore, other Japanese Patent Publication No. 46-21897 and JP-A No. 51-8.
Some tackifiers are disclosed in Japanese Patent No. 7555 and the like, but none of them are sufficient to solve the above-mentioned drawbacks.

The object of the present invention is to provide an EP with improved roll adhesion and tackiness.
A rubber composition is provided.

Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors have found that cyclopentadiene resin containing a polar group is
It was confirmed that the above-mentioned problems could be solved by compounding with P-based rubber, and the present invention was achieved.

That is, the present invention is based on 100 parts by weight of EP rubber, (In the formula, H represents hydrogen, R represents an alkyl group having 1 to 3 carbon atoms, m and n are 0 or an integer of 1 or more, and m + n =
A 5-membered ring compound having a conjugated double bond represented by
Or its Diels-Alder adduct (component A) 10
Compound (Component B) containing 0 part by weight, a polar group selected from a carboxyl group, a carboxylic acid anhydride group, an ester group, a nitrile group and an amide group and a carbon-carbon double bond 1
To 200 parts by weight, or a polar group-containing cyclopentadiene obtained by reacting 100 parts by weight of a resin obtained by polymerizing the above (component A) with 1 to 200 parts by weight of the above (component B). The present invention relates to a rubber composition containing 0.5 to 30 parts by weight of a resin.

The EP rubber used in the present invention is produced by copolymerizing ethylene, α-olefin and / or non-conjugated diene using a known catalyst such as a Ziegler-Natta catalyst. Examples of the α-olefin used as the copolymerization monomer include propylene, 1-butene, and 1-pentene, which are α-olefins having 3 to 5 carbon atoms. Of these, propylene is particularly preferable.

Examples of the non-conjugated dienes used as the copolymerization monomer include the following compounds, and at least one of them is used.

Dicyclopentadiene, tricyclopentadiene, 5-
Methyl-2,5-norbornadiene, 5-methylene-2
-Norbornene, 5-ethylidene-2-norbornene,
5-isopropylidene-2-norbornene, 5-isopropenyl-2-norbornene, 5- (1-butenyl)-
2-norbornene, cyclooctadiene, vinylcyclohexene, 1,5,9-cyclododecatriene, 6-methyl-4,7,8,9-tetrahydroindene, 2,
2'-dicyclopentenyl trans-1,2-divinylcyclobutane, 1,4-hexadiene, 2-methyl-
1,4-hexadiene, 1,6-octadiene, 1,7
-Octadiene, 1,8-nonadiene, 1,9-decadiene, 3,6-dimethyl-1,7-octadiene, 4,
Examples thereof include 5-dimethyl-1,7-octadiene, 1,4,7-octatriene, and 5-methyl-1,8-nonadiene.

Of these non-conjugated dienes, 5-ethylidene-2-norbornene and / or dicyclopentadiene are preferred.

The EP rubber used in the present invention has a composition ratio of 48 to 80 mol% ethylene, 50 to 20 mol% α-olefin and 0 to 10 mol% non-conjugated diene. In the present invention, among these EP rubbers, the Mooney viscosity [ML
_{When 1 + 4} (100 ° C.)] is 20 or more, particularly 50 or more, a more excellent effect is exhibited.

In the present invention, the polar group-containing cyclopentadiene resin blended in the EP rubber has the general formula (In the formula, H represents hydrogen, R represents an alkyl group having 1 to 3 carbon atoms, m and n are 0 or an integer of 1 or more, and m + n =
5) and / or its Diels-Alder adduct (component A) 1 having a conjugated double bond represented by
1 to 200 parts by weight of a compound (component B) containing a polar group selected from a hydroxyl group, a carboxyl group, a carboxylic acid anhydride group, an ester group, a nitrile group and an amide group, and a carbon-carbon double bond with respect to 00 parts by weight. Preferably, the component (B) is 1 to 200 with respect to 100 parts by weight of a resin obtained by copolymerizing 2 to 150 parts by weight or polymerizing the (component A).
It is produced by reacting parts by weight, preferably 2 to 150 parts by weight.

In the production of the polar group-containing cyclopentadiene resin used in the present invention, when the amount of (Component B) is less than 1 part by weight relative to 100 parts by weight of (Component A), it is wound by a roll when preparing an unvulcanized rubber. Insufficient properties, and when it exceeds 200 parts by weight, the vulcanization rate is delayed and the physical properties in the vulcanized state are deteriorated.

The copolymerization of (Component A) and (Component B) has a reaction temperature of 150.
To 300 ° C, preferably 200 to 280 ° C, and a reaction time of 10 minutes to 20 hours, preferably 1 hour to 10 hours. The homopolymerization of (Component A) has a reaction temperature of 150 to 300 ° C., preferably 200 to 28.
The reaction is carried out at 0 ° C. for 10 minutes to 20 hours, preferably 1 hour to 10 hours, or a Friedel-Crafts type catalyst such as aluminum trichloride, aluminum tribromide, boron trifluoride or titanium tetrachloride is used. Use reaction temperature 0 ~
It can be carried out at 80 ° C, preferably in the range of 20 to 50 ° C.

Next, the reaction temperature of the component (B) with the polymer of the (component A) is 100 to 300 ° C., preferably 150 to 300 ° C.
250 ° C., reaction time 10 minutes to 20 hours, preferably 1
It can be performed in the range of 10 hours to 10 hours. When carrying out the copolymerization reaction of (Component A) and (Component B) or homopolymerization of (Component A), benzene, toluene,
Aromatic hydrocarbon such as xylene is added in an amount of 5 to 10 with respect to 100 parts by weight of (Component A) + (Component B) or (Component A).
It is also possible to add 0 parts by weight. After the polymerization reaction, the solvent is removed from the reaction product by a conventional method such as distillation, but the unreacted monomer and the low polymer may be removed if necessary. Particularly when maleic anhydride is used as (Component B), a method of homopolymerizing (Component A) and then reacting (Component B) is advantageous.

As the above-mentioned (component A), cyclopentadiene, methylcyclopentadiene and the like, and as Diels-Alder adducts thereof, dicyclopentadiene,
Cyclopentadiene-methylcyclopentadiene co-dimer, tricyclopentadiene and the like, and mixtures thereof are industrially preferably used, and among these, cyclopentadiene, dicyclopentadiene or a mixture of both are particularly preferable.

It is not always necessary that cyclopentadiene, dicyclopentadiene or an alkyl-substituted derivative thereof have good purity, but it is preferable that 80% by weight or more of cyclopentadiene, dicyclopentadiene or an alkyl-substituted derivative thereof is present.

Further, by dimerizing cyclopentadiene and methylcyclopentadiene contained in the C ₅ fraction of the high temperature pyrolysis by-product oil such as naphtha, dicyclopentadiene,
After forming a mixture of dimethylcyclopentadiene, cyclopentadiene-methylcyclopentadiene co-dimer, etc.,
_{C 5,} such as _{C 5} olefins, _{C 5} paraffins by distillation
A concentrated fraction obtained by removing components and other by-products may be used.

The above-mentioned (Component B) is a compound containing a polar group selected from a carboxyl group, a carboxylic acid anhydride group, an ester group, a nitrile group and an amide group and a carbon-carbon double bond.

Among the compounds, those having a carboxyl group include unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid and itaconic acid, and those having a carboxylic acid anhydride group include maleic anhydride and itaconic anhydride. Acid anhydrides, those having an ester group include vinyl acetate, vinyl propionate, methyl acrylate, methyl protonate, methyl methacrylate, ethyl acrylate, butyl acrylate and other unsaturated esters, and flaxseed oil, tung oil and other natural esters. Examples of the unsaturated ester and those having a nitrile group include nitriles such as acrylonitrile, methacrylonitrile and crotonnitrile, and those having an amide group include acid amides such as acrylamide and methacrylamide.

Further, in the production of the above cyclopentadiene resin, it is also possible to use an unsaturated component in the petroleum fraction, particularly an unsaturated aromatic component, within the range of not more than the equivalent amount of (Component A).
For example, styrene, α-methylstyrene, vinyltoluene, indene, methylindene, and a mixture thereof can be used, and a so-called C ₉ fraction that is by-produced during decomposition of naphtha or the like is industrially preferable.

Further, the resin may be hydrogenated and used for the purpose of improving the hue or odor.

The cyclopentadiene resin used in the present invention preferably has a softening point measured by the ring and ball method (according to JIS K-2531-60) of 50 to 180 ° C., particularly 60 to 160 ° C. When the softening point is lower than 50 ° C., not only the physical properties such as modulus of the rubber composition after vulcanization remarkably decrease, but also the resin causes blocking and the scouring workability deteriorates. On the other hand, when the temperature is higher than 180 ° C., it becomes difficult to uniformly disperse in rubber.

The amount of the cyclopentadiene resin used in the present invention is 0.5 based on 100 parts by weight of EP rubber.
-30 parts by weight, preferably 2-20 parts by weight. If the compounding amount is less than 0.5 part by weight, the effect of addition is not
Roll wrapping property and tackiness are not improved. On the other hand, when the amount is more than 30 parts by weight, the vulcanization rate is delayed and the modulus of the rubber composition after vulcanization is remarkably lowered.

In the present invention, in addition to the cyclopentadiene resin, compounding agents usually used in the rubber industry, for example, reinforcing fillers, vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, softeners, antioxidants Etc. can be blended in an amount usually used as appropriate.

Further, known tackifying resins, for example, chroman resin, terpene resin, phenolic resin, etc., in the range equal to or less than the equivalent amount of the cyclopentadiene resin defined in the present invention, and the cyclopentadiene resin defined in the present invention and the known tackifying resin. Can be used in combination within a range of 30 parts by weight or less with respect to 100 parts by weight of EP rubber.

Further, in the present invention, various rubbery polymers such as natural rubber, styrene-butadiene rubber, butyl rubber, chlorinated butyl rubber, brominated butyl rubber, and butadiene-acrylonitrile rubber may be blended as necessary, but the blending amount is EP. The amount is preferably equal to or less than that of the system rubber, and if too much of the above-mentioned rubbery polymer is used, the weather resistance and heat resistance, which are the features of the EP rubber, may be impaired, which is not preferable.

The rubber composition of the present invention is obtained by mixing the EP rubber, the cyclopentadiene resin defined in the present invention, the compounding agent and the like with a mechanical mixer such as a roll mill or a Banbury mixer.

Examples Hereinafter, Examples will be shown in order to specifically clarify the content of the present invention, but these are only a few of them, and the present invention is not limited to the Examples unless it goes against the gist thereof. Absent.

Synthesis Example 1 560 g of dicyclopentadiene having a purity of 96%, 140 g of vinyl acetate and 300 g of mixed xylene were heated and reacted under stirring in an autoclave at 260 ° C. for 2.5 hours. After completion of the reaction, the autoclave was cooled, and then the content was distilled to remove unreacted monomers, low polymer and xylene, and 549 g of Resin I was obtained as a bottom residue. Resin I
The softening point of 101.5 ° C. was found to contain a large amount of ester groups by infrared spectrum.

Synthesis Example 2 525 g of dicyclopentadiene having a purity of 96%, 175 g of methyl methacrylate (MMA) and mixed xylene 3
00g in an autoclave under stirring at 260 ° C for 2
After reacting for a period of time and treating in the same manner as in Synthesis Example 1, 532 g of Resin II was obtained. Resin II has a softening point of 105.5 ° C and IR
The presence of ester bond was confirmed from the spectrum.

Synthesis Example 3 490 g dicyclopentadiene, allyl alcohol 21
0 g and 300 g of mixed xylene were charged into an autoclave, reacted at 260 ° C. for 4 hours, and treated in the same manner as in Synthesis Example 1 to obtain 527 g of Resin III. The softening point of Resin III was 88.0 ° C. and the hydroxyl value was 210 (mgKOH / g).

Synthesis Example 4 500 g of dicyclopentadiene and 50 of mixed xylene
0 g was placed in an autoclave, reacted at 260 ° C. for 1.5 hours, and treated in the same manner as in Synthesis Example 1 to give a softening point of 89.5.
358 g of 0 ° C. resin was obtained. This resin is heated and melted at 200 ° C., and 11.0 g of maleic anhydride is added,
When reacted for a time, the acid value is 15.4 at a softening point of 106.0 ° C.
(MgKOH / g) Resin IV was obtained.

Synthesis Example 5 Dicyclopentadiene 672 g, maleic anhydride 28 g
Then, 300 g of mixed xylene was charged into an autoclave, heated and reacted at 260 ° C. for 2 hours, and treated in the same manner as in Synthesis Example 1 to obtain 536 g of Resin V. The softening point of Resin V was 109.5 ° C. and the acid value was 16.8 (mgKOH / g).

Synthesis Example 6 630 g of dicyclopentadiene, 70 g of acrylic acid and 300 g of mixed xylene were charged into an autoclave, and 2
The mixture was heated at 60 ° C. for 2 hours and treated in the same manner as in Synthesis Example 1 to obtain 561 g of Resin VI. Resin VI has a softening point of 10
The acid value at 7.0 ° C. was 10.1 (mgKOH / g).

Synthesis Example 7 Dicyclopentadiene 560 g, acrylonitrile 14
0 g and 300 g of mixed xylene were charged into an autoclave, heated and reacted at 260 ° C. for 2 hours, and treated in the same manner as in Synthesis Example 1 to obtain 512 g of Resin VII. The softening point of Resin VII was 105.5 ° C., and absorption of a nitrile group was recognized from the IR spectrum. Comparative Synthetic Example 500 g of dicyclopentadiene having a purity of 96% and 500 g of mixed xylene were charged into an autoclave at 260 ° C.
After heating for 2 hours in the same manner as described in Synthesis Example 1,
63 g of resin VIII were obtained. The softening point of Resin VIII was 93 ° C.

Examples 1 to 6 and Comparative Examples 1 to 4 10 parts of each of the resins obtained in the above Synthesis Examples 1 to 7 and Comparative Synthesis Examples and the control resin were used with respect to 140 parts by weight of EP rubber.
By using parts by weight and the other ingredients shown in Table 1 and kneading with a roll mill at a roll temperature of 120 ° C., a sheet-shaped unvulcanized rubber was obtained. The winding property on the roll and the adhesive force of the unvulcanized rubber sheet when the unvulcanized rubber was prepared were examined.

Next, the vulcanization rate at 160 ° C. was measured using this unvulcanized rubber.

Further, using a press, vulcanization was performed under the conditions of 160 ° C. × 10 minutes and 100 kg / cm ² , and the hardness of the obtained vulcanized rubber was 300%.
The modulus and heat resistance were measured. The above results are shown in Table 1. The results when no resin is added are also shown in Table 1 for comparison.
It was shown to.

Physical property test i) Roll winding property: The winding state on the roll mill at the time of preparing unvulcanized rubber was observed.

X Remarkably poor, △ poor, ○ good ii) Adhesive strength: Measured with "Pykuma tester" manufactured by Toyo Seiki.

The measurement conditions are a temperature of 25 ° C., a load of 500 g, a contact time of 30 seconds, and a peeling speed of 100 mm / min.

iii) Vulcanization rate; Toyo Seiki "Oscillating Disc Rheometer"
Was measured using. The vulcanization temperature is 160 ° C. The vulcanization rate is indicated by the difference between t ₁₀ and t ₉₀ .

t ₁₀ ; time (sec) until 10% of maximum torque is shown t ₉₀ ; time (sec) until 90% of maximum torque is shown iv) hardness; measured by Shore A according to JIS K-6301 did.

v) 300% modulus; measured using a No. 3 dumbbell in accordance with JIS K-6301.

vi) Heat resistance: After being left at 150 ° C. for 3 days, the 300% modulus was measured and shown as a ratio to the 300% modulus before heat deterioration.

EFFECTS OF THE INVENTION As shown in Table 1, the rubber composition obtained by blending the EP group rubber with the polar group-containing cyclopentadiene resin described in the present invention is not vulcanized without significantly decreasing the vulcanization rate and the physical properties after vulcanization. The roll winding property and the tackiness in the state are greatly improved.

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Claims (1)

[Claims] 1. A general formula based on 100 parts by weight of a rubber-like polymer composed of ethylene and α-olefin and / or non-conjugated diene. (In the formula, H represents hydrogen, R represents an alkyl group having 1 to 3 carbon atoms, m and n are 0 or an integer of 1 or more, and m + n =
A 5-membered ring compound having a conjugated double bond represented by
Or its Diels-Alder adduct (component A) 10
Compound (Component B) containing 0 part by weight, a polar group selected from a carboxyl group, a carboxylic acid anhydride group, an ester group, a nitrile group and an amide group and a carbon-carbon double bond 1
To 200 parts by weight, or a polar group-containing cyclopentadiene obtained by reacting 100 parts by weight of a resin obtained by polymerizing the above (component A) with 1 to 200 parts by weight of the above (component B). A rubber composition comprising 0.5 to 30 parts by weight of a resin.