JP3405691B2 - Rubber composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rubber composition which has both low air permeability and adhesiveness with a diene rubber and has improved mechanical strength and physical properties after vulcanization.

[0002]

2. Description of the Related Art Conventionally, a bromide of a copolymer of isobutylene and p-methylstyrene has been used because of its low air permeability and good weatherability.
Halogenated butyl rubber is used as a rubber material, or its use is being studied.

However, the adhesiveness with other diene rubbers is poor, and there is a problem as a material for the rubber laminate.

Further, blending with a diene rubber has been studied, but it is the current situation that low air permeability or weather resistance and vulcanization adhesiveness with the diene rubber have not been achieved at the same time. At the present time, the mechanical strength of the blended rubber is low.

Further, in order to bring out the performance which cannot be obtained with a single rubber, a blend of two or more kinds of rubber is incompatible in many cases, and kneading with a Banbury mixer or the like (high temperature, high shear field) Therefore, even if the material is temporarily made compatible, the phase separation proceeds, and the phase separation state may differ due to the difference in the time from kneading to vulcanization, and the physical properties after vulcanization may change.

As a technique for solving the above-mentioned problems, Japanese Patent Laid-Open No. 10-81784 discloses a low air permeability functional group vulcanizable rubber and a curing agent capable of vulcanizing the functional group vulcanizable rubber. Kneading (pre-kneading) in a temperature range where the functional group vulcanizable rubber does not vulcanize, and the carbon-carbon double bond vulcanizable rubber is added to the obtained kneaded product and kneaded at 90 to 140 ° C. Then, a rubber composition obtained by selectively vulcanizing a functional group vulcanizable rubber is disclosed.

The composition described in the above publication has low air permeability,
Although it is excellent in vulcanization adhesiveness with a diene rubber, it requires two steps to perform selective vulcanization, and therefore further improvement is desired.

[0008]

DISCLOSURE OF THE INVENTION The present inventors
As a result of earnest research after considering the technology, the lower limit of kneading temperature
Increase the temperature (110 ℃ or more) and select the curing agent appropriately.
This makes it possible to perform pre- and post-vulcanization without pre-kneading.
Suppresses changes in the physical properties of, and has low air permeability and diene rubber
Being able to achieve both adhesiveness and extrusion
To find that the workability is improved and to complete the present invention
I arrived. That is, the present invention is (A) At leastp-methylstyrene and isobutylene
Containing bromide of a copolymer ofFunctional vulcanizable rubber, (B) Only the functional group vulcanizable rubber can be selectively vulcanized
Hardener and (C) Carbon-carbon double bond vulcanizable rubber Kneading the functional group vulcanizable rubber in a temperature range in which it can be vulcanized.
While selectively kneading the functional group vulcanizable rubber while
A rubber composition obtained by vulcanization (claim 1);p-me
Bromide of copolymer of tylstyrene and isobutylene
outsideFunctional group The functional group of vulcanizable rubber is hydroxyl group, carboxy
Group, amino group, isocyanate group, epoxy group, halo
Gen atom, polymer group containing fluorine atom, acid anhydride group, S
Tell, chlorosulfone, methylol and sulfo
The rubber set according to claim 1, which is at least one acid group.
(Claim 2), the curing agent is an organic curing agent and
(Or) An inorganic curing agent according to claim 1 or 2.
Composition (claim 3), The curing agent is a divalent metal (M
at least one oxide of g, Zn, Ca or Ba)
Claim 1 which is,2 orOrThreeRubber composition according to claim (claim
Four), And a kneading temperature of 110 to 150 ° C.
Requirement 1, 2,3OrFourRubber composition according to claim (claim5)
Regarding

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber composition of the present invention comprises (A) a copolymerization of at least p-methylstyrene and isobutylene.
Functional group vulcanizable rubber containing bromide of body , (B) curing agent capable of selectively vulcanizing only the functional group vulcanizable rubber, and (C) carbon-carbon double bond vulcanizable rubber A rubber composition obtained by selectively vulcanizing the functional group vulcanizable rubber while kneading the functional group vulcanizable rubber in a temperature range in which the functional group vulcanizable rubber can be vulcanized.

In the present invention, the mixture of the components (A) to (C) is kneaded in a temperature range in which the component (A) can be vulcanized. Therefore, the component (A) is selectively mixed during the kneading. Can be vulcanized. Further, in the present invention, the pre-kneading of the component (A) and the component (B) before the selective vulcanization is not performed,
Since the components (A) to (C) are kneaded from the beginning to selectively vulcanize the component (A), the manufacturing process can be shortened. Further, by performing the selective vulcanization as described above, it is possible to improve the extrusion processability, further suppress the change in the physical properties of the resulting rubber composition before and after vulcanization, and improve the mechanical strength, Effects such as low air permeability and adhesiveness with the diene rubber can be obtained.

The functional group vulcanizable rubber (hereinafter also referred to as the functional group vulcanizable rubber (A)) which is the component (A) is a rubber molded article obtained from the rubber composition of the present invention, which has excellent low air permeability. And a functional group other than the carbon-carbon double bond serves as a crosslinking point.

[0012] The functional group vulcanizable rubber (A), less
Of the copolymer of p-methylstyrene and isobutylene
Any substance containing a bromide and having a functional group as a crosslinking point may be used. Although it may have a carbon-carbon double bond,
In that case, the degree of unsaturation (IV) is 50 or less, preferably 3
It is preferably 0 or less, and further preferably has a low unsaturation (highly saturated) of 25 or less in order that the functional group can specifically serve as a crosslinking point. In other words, functional group vulcanizable rubber (A)
Is preferably one that cannot be vulcanized with sulfur or is difficult to cure.

The functional group vulcanizable rubber (A) may be a rubber having a functional group vulcanizability, and may be a rubber as a raw material (hereinafter
It may be produced by introducing a functional group into the raw material rubber (I).

Co-production of p-methylstyrene and isobutylene
Examples of the rubber having the functional group vulcanizability other than the bromide of the polymer include , for example, fluororubber, epichlorohydrin rubber, halogenated butyl rubber, chloroprene rubber , epoxylated natural rubber and acrylonitrile-butadiene rubber ( NBR) and the like. In these cases,
The functional group may not be newly introduced, but may be introduced.

Examples of the functional group vulcanizable rubber (A) produced by introducing a functional group into the raw rubber (I) include:
Raw material rubber (I) having no or insufficient functional groups contributing to vulcanization of functional groups (for example, butyl rubber, ethylene / acrylic ester copolymer rubber, ethylene-propylene-
Diene rubber (EPDM) and the like), functional groups contributing to functional group vulcanizability (groups capable of vulcanization (crosslinking) by a curing agent described later), for example, hydroxyl group (-OH), carboxyl group (-COOH), amino group (-NH _2), isocyanate group (-NCO), an epoxy group

[0016]

[Chemical 1]

Acid anhydride group

[0018]

[Chemical 2]

A halogen atom (--F, --Cl, --Br,
-I), a fluorine atom-containing polymer group, an ester group, chlorosulfonic group (-SO ₂ Cl), methylol group (-CH ₂ O
H), a sulfonate group, a nitrile group (—CN), a chloromethyl group (—CH ₂ Cl) and the like may be introduced. Among the functional groups, a halogen atom, an acid anhydride group, a carboxyl group and an epoxy group are preferable, and a halogen atom is more preferable, from the viewpoint of rapid reaction.

The above-mentioned functional group vulcanizable rubber (A) is a p-methyl rubber.
A bromide of a copolymer of styrene and isobutylene may be used alone, and p-methylstyrene and isobutylene may be used alone.
You may use it in combination of 2 or more types containing the bromide of the copolymer with . Of these, air permeability is lower than that of diene rubber such as natural rubber (NR),
Those using NBR, halogenated butyl rubber, bromide of isobutylene / p-methylstyrene copolymer rubber, chloroprene rubber, epoxidized natural rubber and EPDM are preferable. However, in the case of NBR and EPDM, it is necessary to introduce a functional group or use one that has already been introduced. These rubbers may be blended with a double bond vulcanizable rubber which is the component (C) after introducing a functional group, if necessary.

As a method for introducing the functional group into the raw rubber (I), a generally used method may be used. For example, in order to introduce a hydroxyl group, a slight double bond in the raw rubber (I) is used. There are so-called oxymercuration-demercury method or hydroboration oxidation method to be used, and hydrolysis method when the raw rubber (I) contains halogen. To introduce the carboxyl group, there is a method of oxidizing the primary alcoholic hydroxyl group with potassium permanganate or the like, or a carbonation method using a Grignard reagent. In order to introduce an amino group, there are a method of halogenating an alcoholic hydroxyl group for amination, a method of nitriding a bromide of p-methylstyrene and reducing the same. To introduce the epoxy group, there is a method using formic acid and hydrogen peroxide solution.

The amount of the above-mentioned functional group may be appropriately selected depending on the application, but is usually 0.1 to 50 per 100 repeating units.
It is preferable that there are 0.3, more preferably 0.3 to 10. Even if the amount of functional groups is large, the crosslinking density can be controlled by the amount of the curing agent (B) described later.

The number average molecular weight of the functional group vulcanizable rubber (A) is preferably 100,000 to several million, and the preferable Mooney viscosity (M
L (1 + 4) 130 degreeC) is 20-80.

Examples of the commercially available functional vulcanizable rubber (A) include EXXPRO manufactured by Exxon Chemical Co., Ltd.
90-10 (brominated isobutylene / p-methylstyrene copolymer rubber), bromobutyl 2222 (bromobutyl rubber) manufactured by Exxon Chemical Co., Ltd., chlorobutyl 1066 (chlorobutyl rubber) manufactured by Exxon Chemical Co., Showa Denko ( Co., Ltd. or DuPont Neoprene WRT (chloroprene rubber), Guthrie Co. epoxidized natural rubber, Sumitomo Chemical Co., Ltd. Esplen EMA
2752 (ethylene / acrylic acid ester copolymer rubber), Royal Tough 490 (malein oxide EPDM) manufactured by Uniroyal Co., and the like can be mentioned. Among these, EXXPRO 90-1 manufactured by Exxon Chemical Co., Ltd.
0, Royal Tough 490 manufactured by Uniroyal Corp. is preferable from the viewpoint of high reactivity.

Functional group vulcanizable rubber (A) as component (B)
A curing agent capable of selectively vulcanizing (hereinafter, also referred to as a curing agent (B)) is a functional group vulcanizable rubber (A) having a functional group other than carbon-carbon double bond present between molecules. A compound that is crosslinked (vulcanized) and specifically reacts with the functional group,
For example, organic curing agents and inorganic curing agents (excluding sulfur) described below are preferably used.

As the organic curing agent, N, N'-diethylthiourea (EUR), N-phenyl-N '-(1,
3-dimethylbutyl) -p-phenylenediamine, 4,
Polyamines such as 4'-diamino-diphenyl ether; polycarboxylic acids such as suberic acid, oxalic acid, succinic acid, adipic acid, maleic acid; ethylene glycol,
Polyols such as propylene glycol; 2,4-tolylene diisocyanate, diphenylmethane-4,4'-
Polyisocyanates such as diisocyanates; zinc diethyldithiocarbamate, dipentamethylene thiuram tetrasulfide and the like. These may be used alone or in combination of two or more. Among the organic curing agents, polyamine is a functional group vulcanizable rubber (A) when the functional groups are, for example, a carboxyl group, a halogen atom, an acid anhydride group and a hydroxyl group, and the polycarboxylic acid is an amino group and an epoxy group. Polyols and polyisocyanates are preferably used as the curing agent (B) when they have amino groups.

As the above-mentioned inorganic curing agent, Mg, Zn, C
Examples thereof include oxides, carbonates and hydroxides of divalent metals such as a and Ba. These may be used alone or in combination of two or more. When the functional group of the functional group vulcanizable rubber (A) is, for example, a halogen atom, it is preferable to use these inorganic curing agents, but from the viewpoint of high reactivity, divalent Mg, Zn, Ca or Ba. In particular, an oxide of divalent Zn is particularly preferable.

The kneading ratio of the organic curing agent is 100 parts by weight of the functional group vulcanizable rubber (A) (hereinafter, referred to as a kneading ratio) from the viewpoint of shortening the kneading time and improving the physical properties of the rubber.
It is preferably 0 to 10 parts, more preferably 0 to 3 parts. In addition, the kneading ratio of the inorganic curing agent is 1 to 20 parts with respect to 100 parts of the functional group vulcanizable rubber (A), from the viewpoint of shortening the kneading time and improving the physical properties of the rubber. Is preferably from 2 to 18 parts. These organic curing agents and inorganic curing agents may be used alone or in combination. When used in combination, each may be used within the range of the above kneading ratio, and the total kneading ratio of the curing agent (B) is 1 to 100 parts of the functional group vulcanizable rubber (A). It is preferably 30 parts, more preferably 2 to 21 parts.

Carbon-carbon double bond vulcanizable rubber (hereinafter also referred to as double bond vulcanizable rubber (C)) which is the component (C).
Has a carbon-carbon double bond as a cross-linking point.

The double bond vulcanizable rubber (C) may have a functional group other than the carbon-carbon double bond, but the content of the functional group is preferably as low as possible, and the repeating unit per 100 repeating units. 0.
It is preferably about 1 to 5 or less. However, (A)
The functional group content of the component (C) is preferably half or less as compared with the functional group content of the component. On the other hand, the carbon-carbon double bond content is preferably high, and the double bond vulcanizable rubber preferably has an unsaturation degree of 50 or more, more preferably 70 or more, and particularly 90 when it has a functional group. The above is preferable.

Examples of the double bond vulcanizable rubber (C) include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber (SBR), diene rubbers such as NBR and the like. These may be used alone or in combination of two or more. Of these, natural rubber, in terms of improving mechanical strength,
It is preferable to use SBR or NBR, and it is preferable to use natural rubber from the viewpoint of providing tackiness.

The kneading ratio of the double bond vulcanizable rubber (C) is 20 with respect to 100 parts of the functional group vulcanizable rubber (A).
~ 500 parts, further 20 to 50 parts from the viewpoint of reducing the air permeability, further 5 from the viewpoint of increasing the adhesive strength.
It is preferably from 0 to 500 parts.

The rubber composition of the present invention may further contain, as other components, a vulcanization accelerator such as stearic acid, a process oil, a filler, an antioxidant and the like, and the rubber composition of the present invention and the rubber composition. You may mix | blend in the range which does not reduce the outstanding effect of the rubber molded article obtained from. In addition,
The composition of the present invention suppresses changes in physical properties before and after vulcanization, but particularly in a composition containing an antioxidant, the effect of suppressing changes in physical properties before and after vulcanization can be remarkably exhibited. .

Examples of the antiaging agent include Nocrac 224 (manufactured by Ouchi Shinko Chemical Co., Ltd.) and Antigen FR (manufactured by Sumitomo Chemical Co., Ltd.). These are usually rubber components (total of (A) component and (B) component) 1
0.5 to 5 parts are used with respect to 00 parts.

The composition of the present invention selectively selects the component (A) while kneading the components (A) to (C) and, if necessary, the other components in a temperature range where the component (A) can be vulcanized. It is obtained by vulcanizing during kneading.

When the components (A) to (C) are mixed,
Without pre-kneading the components (A) and (B),
First, the components (A) and (C) are kneaded, and then the component (B) is added. However, there may be some difference in the time of preparation within the range of common sense for those skilled in the art. Therefore, for example, the (A) component (or (C) component), the (C) component (or (A) component) and the (B) component may be charged simultaneously or sequentially into a container for kneading.

The selective vulcanization (kneading) may be carried out within a temperature range in which the component (A) begins to vulcanize and does not cause deterioration of the obtained rubber composition, but it is called shortening of kneading time. 110-150 ℃ from the point, further 115-140
It is preferably carried out at a temperature of ° C. Further, it is preferable to knead in an open roll from the viewpoint of stabilizing the physical properties, and kneading in a Banbury mixer from the viewpoint of improving workability and workability.

The time required for the selective vulcanization is usually 3
-30 minutes, and further 4-18 minutes.

In the vulcanization of the double bond vulcanizable rubber in the rubber composition (I), for example, sulfur, which is a vulcanizing agent for the double bond vulcanizable rubber, is added in a predetermined amount (for example, the rubber component ((A)). 0.5 to 5 for 100 parts of the total of the components and the component (C))
Part) In addition to the rubber composition (I), if necessary, stearic acid,
Vulcanization accelerator such as N-tert-butyl-2-benzothiazolylsulfenamide (NS), process oil,
A filler such as carbon black and an anti-aging agent may be appropriately mixed, further kneaded at 40 to 100 ° C., molded, and then heated.

The component (B) used may be charged from the beginning, or may be charged in two or more times. For example, (A) component and (C) component and a part of (B) component are initially charged and kneaded, and (A) component is selectively vulcanized to obtain a rubber composition (I). When compounding sulfur or a vulcanization accelerator for vulcanizing the double bond vulcanizable rubber (C) into the rubber composition (II), a lumber may be charged. However, when the component (B) is charged in two or more times, first of all,
Addition of an amount of 0 to 80% by weight results in a rubber composition having good physical properties.

The rubber composition (II) has excellent vulcanization adhesion with other diene rubber compositions, and is usually molded by a molding method such as roll or extrusion, and then finally subjected to double bond addition. By vulcanizing the vulcanizable rubber (C), a rubber molded product excellent in low air permeability can be obtained. Furthermore, it has excellent mechanical strength after vulcanization and has little variation in physical properties before and after vulcanization. It also has good physical properties such as extrudability, and has high storage stability of unvulcanized rubber.

The rubber composition of the present invention can be used for various purposes, and is preferably used for tire inner liners, cases, tubes, gas hoses and the like.

As a preferred embodiment of the present invention, for example, the following rubber composition and kneading conditions can be mentioned.

Example 1 Functional group vulcanizable rubber (EXXPRO 90-10) 100 parts Organic curing agent (EUR) 0-3 parts Inorganic curing agent (ZnO) 10-18 parts Double bond vulcanizable rubber (natural Rubber) 25 to 50 parts Kneading temperature 120 to 140 ° C. Kneading time 4 to 15 minutes (However, 2 to 10 parts of ZnO is first vulcanized and then the rest is mixed.) This rubber The composition is particularly advantageous in that it has a low air permeability, suppresses an increase in Mooney viscosity over time, and can obtain a rubber molded product with little variation in physical properties.

(Example 2) Functional group vulcanizable rubber (EXXPRO 90-10) 100 parts Organic curing agent (4,4'-diamino-diphenyl ether) 0-3 parts Inorganic curing agent (ZnO) 10-18 parts Duplex Bonded vulcanizable rubber (natural rubber) 50 to 500 parts Kneading temperature 110 to 140 ° C. Kneading time 4 to 15 minutes (However, ZnO is initially 2 to 10 parts, and after selective vulcanization, This rubber composition is particularly advantageous in that it has excellent tensile properties and vulcanization adhesion to diene rubber.

As an aspect not included in the present invention,
For example, mention the following rubber composition and kneading conditions.
be able to. (Example 3) Functional group vulcanizable rubber (epoxidized natural rubber) 100 parts Organic curing agent (EUR) 1 to 3 parts Inorganic curing agent (ZnO) 10 to 18 parts Double bond vulcanizable rubber (natural rubber) 50 ˜500 parts Kneading temperature 110˜140 ° C. Kneading time 4˜12 minutes (However, 2 to 10 parts of ZnO is first mixed with the rest after selective vulcanization.) This rubber composition is It is particularly advantageous in that a rubber molded product having not only good low air permeability and vulcanization adhesiveness but also high hardness can be obtained.

(Example 4) Functional group vulcanizable rubber (halogenated butyl rubber) 100 parts Organic curing agent (EUR) 0-3 parts Inorganic curing agent (ZnO) 10-18 parts Double bond vulcanizable rubber (natural rubber) 20 to 500 parts Kneading temperature 120 to 140 ° C. Kneading time 4 to 18 minutes This rubber composition is particularly advantageous in that it has low air permeability.

[0048]

EXAMPLES Next, the rubber composition of the present invention will be specifically explained based on examples, but the present invention is not limited to these.

The raw materials and evaluation methods used in the examples and comparative examples are summarized below.

EXXPRO 90-10: Bromide of a copolymer of isobutylene and p-methylstyrene manufactured by Exxon Chemical Co., Ltd. HAF N330: Carbon black (Dia Black H) manufactured by Mitsubishi Chemical Co., Ltd. Antiaging agent FR : Antigen FR manufactured by Sumitomo Chemical Co., Ltd. Stearic acid: Zinc flower stearate manufactured by NOF CORPORATION No. 1: Zinc oxide sulfur manufactured by Mitsui Mining & Smelting Co., Ltd .: Sulfur powder accelerator manufactured by Tsurumi Chemical Co., Ltd. NS: Ouchi Shinko Chemical Co., Ltd. N-tert-butyl-2-benzothiazyl sulfenamide (Nocceller NS)

(Moonie Test) The Mooney viscosity of the green rubber composition was measured at 130 ° C. according to JIS K6300.

(Tensile Test) According to JIS K6301, a tensile test was conducted at a tensile speed of 500 mm / min using a sample of a predetermined vulcanized rubber having a JIS No. 3 dumbbell shape.

(Spring Strength) According to JIS K6253, the spring hardness of a given vulcanized rubber was measured with an A type.

(Adhesion test) A predetermined green rubber composition was rolled into a sheet having a thickness of 2 mm, and the width was 80 mm.
A rubber sheet 1 having a length of 150 mm was cut out. In addition, a blend of natural rubber and butadiene rubber in a weight ratio of 40:60 (including carbon black, sulfur and a vulcanization accelerator) was rolled into a sheet having a thickness of 2 mm, and then a width of 8
A diene rubber sheet 2 having a length of 0 mm and a length of 150 mm was cut out.

As shown in FIG. 1, a rubber sheet 1 and a diene rubber sheet 2 are brought into close contact with each other, and a member composed of a mylar sheet 4 and a thick weave 5 is inserted so that peeling starts at the interface, and the rubber is peeled off at the time of peeling. Reinforce top cloth 3 to prevent the sheet from being cut, and 170kg for 15 minutes at 10kgf /
A sample for adhesion test was prepared by vulcanization adhesion with a press pressure of cm ² . In this test, the top cloth 3 has a thickness of 1 mm and a width of 8
A polyester fiber having a length of 0 mm and a length of 150 mm and rubber-coated was used. The mylar sheet 4 is for preventing the rubber sheet 1 and the diene rubber sheet 2 from adhering over the entire surface at the time of vulcanization, and is 180 ° C.
Any material having the above melting point may be used. In this test, a polyethylene terephthalate having a thickness of 0.05 mm, a width of 80 mm and a length of 40 mm was used. Atori 5
Is inserted to start peeling at the adhesive interface. In this test, the thickness is 0.5 mm, the width is 80 mm, and the length is 80 mm.
A nylon fiber having a size of mm was used.

The adhesive strength (peel strength) of the sample was measured with a tensile tester manufactured by Intesco at a speed of 50 mm / m.
It was measured in.

(Air permeability test) A predetermined green rubber composition was vulcanized and molded by a hydraulic press to obtain a vulcanized rubber sheet having a thickness of about 1 mm. The vulcanization conditions are vulcanization pressure 100 kgf.
/ Cm ² , 170 ° C., 15 minutes.

Next, the air permeability of the obtained vulcanized rubber sheet was measured according to the ASTM D-1434-75M method to be 2
It was measured at 0 ° C. The measuring device is a constant temperature gas permeability measuring device (GTRTESTER MC manufactured by Toyo Seiki Co., Ltd.)
1) was used.

Example 1 and Comparative Example 1 The raw materials (a) shown in Table 1 were mixed in the ratio shown in Table 1 to obtain 12
The mixture was kneaded in Banbury at 0 ° C for 8 minutes. The raw material (B) shown in Table 1 was added to the obtained kneaded product (rubber composition (I)) at a ratio shown in Table 1, and the mixture was kneaded with an open roll at 50 ° C. for 5 minutes to obtain a green rubber composition (rubber). A composition (II)) was obtained. That is, the same operation was performed in Example 1 and Comparative Example 1 except that the timing of adding Zinc Hua No. 1 was different. Using the obtained green rubber composition, a sample was prepared by the above method, and an adhesion test and an air permeability test were conducted. In addition, 1 day and 8 days after the green rubber composition was obtained, the composition was vulcanized under the Mooney test and 170 ° C. for 15 minutes to obtain a vulcanized rubber. The tensile test and the spring hardness of the vulcanized rubber were measured. The results are shown in Table 1.

[0060]

[Table 1]

From Table 1, it is understood that in Comparative Example 1, the vulcanized rubber becomes hard. Further, the Mooney viscosity sharply increases with the lapse of days from the day when the green rubber composition is obtained,
There is a bad tendency that the growth rate also decreases.

On the other hand, in the case of Example 1, it can be seen that the increase in Mooney viscosity is suppressed and the change in vulcanized rubber is reduced.

From this, according to the manufacturing method of the present invention, it is possible to supply a product with less variation.

Examples 2 and 3 and Comparative Examples 2 and 3 The raw materials (a) shown in Table 2 were mixed in the proportions shown in Table 2, the mixer temperature was set to 110 ° C., and the mixer indicated temperature was 13%.
The mixture was kneaded for about 8 minutes until it reached 0 ° C. The raw material (b) shown in Table 2 was added to the obtained kneaded product at a ratio shown in Table 2, and the mixture was kneaded with an open roll at 50 ° C. for 5 minutes to obtain a green rubber composition. That is, the same operations as in Examples 2 and 3 and Comparative Examples 2 and 3 were performed except that the timing of adding Zinc Hua No. 1 was different. An adhesion test and an air permeability test were conducted using the obtained green rubber composition. Further, a tensile test was carried out on a vulcanized rubber obtained by vulcanizing the green rubber composition at 170 ° C. for 15 minutes. The results are shown in Table 2.

[0065]

[Table 2]

From Table 2, it is understood that in Comparative Examples 2 and 3, the adhesive strength with the diene rubber is small, the air permeability and the adhesive strength are not compatible, and the elongation is also small.

On the other hand, in the case of Examples 2 and 3, the adhesive strength with the diene rubber was significantly improved, air permeability and adhesive strength were compatible, the elongation was large, and the tensile strength was also improved. I understand.

Further, it was obtained by the same operation as in Examples 2 and 3 and Comparative Examples 2 and 3 except that FR 2 parts of the antioxidant was added to the raw material (a) shown in Table 2. The Mooney test of the green rubber composition was carried out in the same manner as in Example 1. As a result, the green rubber compositions of Examples 2 and 3 were suppressed from increasing the Mooney viscosity as compared with Comparative Examples 2 and 3, and were also tested. The vulcanized rubber obtained by vulcanizing in the same manner as in Example 1 was subjected to the tensile test and the spring hardness measurement in the same manner as in Example 1. As a result, the change in vulcanized rubber was also compared in Examples 2 and 3. It was smaller than Examples 2 and 3.

[0069]

EFFECTS OF THE INVENTION According to the present invention, a rubber composition having excellent extrusion processability, low air permeability and adhesiveness with a diene rubber, and improved mechanical strength and variations in physical properties before and after vulcanization. You can get things.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of adhesion test samples prepared for measuring adhesive strength in Examples and Comparative Examples.

[Explanation of symbols]

1 rubber sheet 2 Diene rubber sheet 3 top anti 4 Mylar sheet 5 thick woven

Front page continuation (51) Int.Cl. ⁷ identification code FI // B29K 21:00 B29K 21:00 105: 24 105: 24 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 7 / 00-21/00 C08L 23/28 C08L 25/16

Claims (5)

(57) [Claims] 1. (A) at least p-methylstyrene
Functional group vulcanizable rubber containing a bromide of a copolymer with isobutylene , (B) a curing agent capable of selectively vulcanizing only the functional group vulcanizable rubber, and (C) carbon-carbon double bond A rubber composition obtained by selectively vulcanizing the functional group vulcanizable rubber while kneading the vulcanizable rubber in a temperature range in which the functional group vulcanizable rubber can be vulcanized. 2. The p-methylstyrene and isobutylene
Functional group other than the bromide of the copolymer with the functional group of the vulcanizable rubber is a hydroxyl group, a carboxyl group, an amino group, an isocyanate group, an epoxy group, a halogen atom, a fluorine atom-containing polymer group, an acid anhydride group , Ester group, chlorosulfone group,
The rubber composition according to claim 1, which is at least one of a methylol group and a sulfonate group. 3. The rubber composition according to claim 1, wherein the curing agent is an organic curing agent and / or an inorganic curing agent. 4. The hardener is a divalent metal (Mg, Z
n, Ca or Ba) at least one kind of claim 1, 2 or 3 rubber composition according oxides. 5. The kneading temperature, according to claim 1 which is 110 to 150 ° C., 3 or 4 rubber composition.