KR20200143378A - Rubber composition containing butyl rubber, resol-type phenols formaldehyde cocondensation resin, and phenols - Google Patents

Abstract

A rubber composition containing butyl rubber, resol-type phenol formaldehyde cocondensation resin, and phenols, as the phenols, at least one selected from the group consisting of formulas (1), (2), (3) and (4) At least one selected from the group consisting of a rubber composition containing phenols and a method for producing the same, and a resol-type phenol formaldehyde cocondensation resin, and general formulas (1), (2), (3) and (4) There is provided a resin mixture containing phenols of.

Description

Rubber composition containing butyl rubber, resol-type phenols formaldehyde cocondensation resin, and phenols

The present invention relates to a rubber composition comprising a butyl rubber, a resol-type phenol formaldehyde cocondensation resin, and a phenol having a specific structure.

Butyl rubber (IIR) has excellent environmental resistance and electrical properties such as heat aging resistance, chemical resistance, and weather resistance, and is preferably used in various rubber products. However, butyl rubber is a copolymer of isobutylene and a small amount of isoprene, and since there are few unsaturated bonds serving as a crosslinking point, the crosslinking speed is slow, and there is also a limit to the applicable crosslinking method.

As an industrial crosslinking method of butyl rubber, a method of using a resol-type phenol formaldehyde cocondensation resin as a crosslinking agent is common.

On the other hand, in the case of crosslinking butyl rubber by using a resol-type phenol formaldehyde cocondensation resin as a crosslinking agent, the crosslinking speed is low with the resin alone. Therefore, in particular, when conducting industrially, usually inorganic halogen compounds such as tin chloride and ferric chloride, halogen-containing elastomers such as chloroprene rubber, chlorosulfonated polyethylene, organic acids, or halogenated alkylphenol/formaldehyde balls. Crosslinking accelerators such as condensation resins are used in combination.

However, when the above-mentioned compound or resin or organic acid having a halogen atom is used as a crosslinking accelerator, a problem of causing corrosion of a metal mold occurs during crosslinking molding of butyl rubber. Therefore, a method of improving the crosslinking rate without using such a crosslinking accelerator is being studied.

For example, Japanese Laid-Open Patent Publication No. 2002-234968 (Patent Document 1) proposes a method of using a mixture of a resol-type phenolic formaldehyde cocondensation resin and a novolac-type phenolic formaldehyde cocondensation resin as a resin crosslinking agent, According to the method, it is described that the crosslinking rate is improved even if a compound or resin having a halogen atom, or an organic acid is not used as a crosslinking accelerator.

Japanese Unexamined Patent Publication No. 2002-234968

Therefore, as a result of further testing the method described in Patent Document 1 by the present inventors, the crosslinking rate was improved, but the adhesiveness of the resin crosslinking agent described in the above patent document or the rubber composition (uncrosslinked rubber composition) containing the resin crosslinking agent It was very high, and it was found that it was difficult to industrially use the resin crosslinking agent because adhesion or contamination to the manufacturing apparatus occurred in the kneading step or the molding step.

It is an object of the present invention to use a resin crosslinking agent to crosslink butyl rubber, a rubber composition having excellent crosslinking speed (unvalued), even if a compound or resin having a halogen atom or an organic acid having a possibility of metal corrosion is not used as a crosslinking accelerator. It is to provide a bridge rubber composition).

As a result of intensive investigation by the present inventors in order to solve the above problem, it was found that a rubber composition containing a resol-type phenol formaldehyde cocondensation resin and phenols having a specific structure can solve the above problem. Specifically, the present invention includes the following inventions.

〔One〕

As a rubber composition containing butyl rubber, resol-type phenols formaldehyde cocondensation resin, and phenols,

As the phenols, the following general formula (1):

[Formula 1]

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)

Compound represented by, the following general formula (2):

[Formula 2]

(In said general formula (2), n represents the integer of 1-9.)

Compound represented by, the following general formula (3):

[Formula 3]

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)

A rubber composition containing at least one phenol selected from the group consisting of a compound represented by and bis(4-hydroxyphenyl)sulfone.

〔2〕

The rubber composition according to [1], comprising 8 to 20 parts by weight of resol-type phenols formaldehyde cocondensation resin and 0.01 to 2.0 parts by weight of phenols based on 100 parts by weight of butyl rubber.

(3)

The rubber composition according to [1] or [2], wherein the content of the halogen atom contained in the rubber composition is 0.1% by weight or less.

〔4〕

Resol-type phenols formaldehyde cocondensation resin and the following general formula (1):

[Formula 4]

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)

Compound represented by, the following general formula (2):

[Formula 5]

(In said general formula (2), n represents the integer of 1-9.)

Compound represented by, the following general formula (3):

[Formula 6]

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)

A compound represented by and at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone is mixed in advance to obtain a resin mixture, and the resin mixture and butyl rubber are mixed, [1] to [ 3] The method for producing a rubber composition according to any one of claims.

(5)

Resol-type phenols formaldehyde cocondensation resin,

The following general formula (1):

[Formula 7]

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)

Compound represented by,

The following general formula (2):

[Formula 8]

(In said general formula (2), n represents the integer of 1-9.)

Compound represented by,

The following general formula (3):

[Formula 9]

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)

Compound represented by,

And at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone

Resin mixture comprising a.

(6)

A crosslinked rubber composition obtained by crosslinking the rubber composition according to any one of [1] to [3].

According to the present invention, when crosslinking butyl rubber using a resin crosslinking agent, a rubber composition having excellent crosslinking speed without using a compound or resin or organic acid having a halogen atom that may corrode metal, or an organic acid as a crosslinking accelerator (uncrosslinked rubber Composition). In addition, the rubber composition of the present invention is suitably controlled in tackiness, and it is possible to avoid sticking or contamination to the manufacturing apparatus in the molding process.

In addition, the crosslinked rubber composition obtained by crosslinking the rubber composition of the present invention has improved crosslinking density, processability and moldability compared to a rubber composition crosslinked by a known method. In this case, crosslinking with excellent swelling resistance and solvent resistance A rubber composition can be provided.

Hereinafter, the present invention will be described in detail. The rubber composition of the present invention includes a butyl rubber, a resol-type phenol formaldehyde cocondensation resin, a compound represented by the general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3), And at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone.

The butyl rubber used in the rubber composition of the present invention is a synthetic rubber produced by copolymerization of isobutylene and isoprene, and generally has an unsaturation degree of 0.6 mol% to 2.8 mol% and a Mooney viscosity of 20 to 90 M.

As resol-type phenol formaldehyde cocondensation resin contained in the rubber composition of the present invention, for example, resol-type phenol-formaldehyde cocondensation resin, resol-type alkylphenol/formaldehyde cocondensation resin, resol-type resorcinol/phenol. Formaldehyde cocondensation resin, resol-type resorcinol, cresol, formaldehyde cocondensation resin, etc. are mentioned. Among these cocondensation resins, resol-type alkylphenol/formaldehyde cocondensation resins are preferable from the viewpoint of compatibility with rubber, and resol-type alkylphenols, which are alkyl groups in which the alkyl group of the alkylphenol may have a branch having 1 to 20 carbon atoms. A formaldehyde cocondensation resin is more preferable, and a resol-type alkylphenol-formaldehyde cocondensation resin, which is an alkyl group in which the alkyl group of the alkylphenol may have a branch having 4 to 12 carbon atoms, is particularly preferable. The rubber composition of the present invention may contain one or two or more types of resol-type phenol formaldehyde cocondensation resins.

The softening point of the resol-type phenol formaldehyde cocondensation resin contained in the rubber composition of the present invention is usually 120°C or less, preferably 80 to 110°C. Although it differs depending on the type of phenols constituting the cocondensation resin, the use of a resin with a softening point of 120°C or less improves the dispersibility when preparing the rubber composition, so that the temperature at the time of rubber kneading can be lowered, making it easier to use. Thus, the rubber composition of the present invention can be prepared.

Specific examples of the resol-type phenol formaldehyde cocondensation resin contained in the rubber composition of the present invention include, in addition to the resin prepared in the section of Examples to be described later, Takkyrol 201 manufactured by Taoka Chemical Industries, Ltd., and Hitachi Chemical Industry Co., Ltd. ) Manufactured HITANOL 2501, Schenectady International Inc. Manufacturing SP-1044, SP-1045, etc. are mentioned.

The rubber composition of the present invention preferably contains 8 to 20 parts by weight, and more preferably 10 to 18 parts by weight, of a resol-type phenol formaldehyde cocondensation resin with respect to 100 parts by weight of butyl rubber. If the content of the resol-type phenol formaldehyde cocondensation resin is 8 parts by weight or more, the crosslinking rate can be further improved, and when the content is 20 parts by weight or less, the unreacted (not involved in crosslinking) cocondensation resin Can be reduced.

Consisting of the compound represented by the general formula (1), the compound represented by the general formula (2), the compound represented by the general formula (3), and bis(4-hydroxyphenyl)sulfone contained in the rubber composition of the present invention Among at least one phenol selected from the group (hereinafter, it may be referred to as specific phenols), specifically as phenols represented by the general formula (1), for example, bisphenol A (2,2-bis(4-hydro Oxyphenyl)propane), bisphenol F (4,4'-dihydroxydiphenylmethane), bisphenol B (2,2-bis(4-hydroxyphenyl)butane), bisphenol E (1,1-bis(4 -Hydroxyphenyl)ethane), bisphenol AP (1,1-bis(4-hydroxyphenyl)-1-phenylethane), bisphenol BP (bis(4-hydroxyphenyl)diphenylmethane), and the like. , As phenols represented by the general formula (2), specifically, for example, bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), 1,1-bis(4-hydroxyphenyl)cyclodo Decane and the like can be mentioned, and specific examples of the phenols represented by the general formula (3) include 1,2-bis(4-hydroxyphenyl)ethane, 1,1,2,2-tetrakis(4- And hydroxyphenyl)ethane. The rubber composition of the present invention may contain one or two or more specific phenols.

The rubber composition of the present invention contains preferably 0.01 to 2.0 parts by weight, more preferably 0.01 to 1.5 parts by weight, still more preferably 0.03 to 1.5 parts by weight of specific phenols with respect to 100 parts by weight of butyl rubber. By setting the content of the specific phenols to 0.01 parts by weight or more, the crosslinking rate can be further improved, and by setting the content to 2.0 parts by weight or less, the dispersibility of the specific phenols in the rubber can be improved.

According to the rubber composition of the present invention, since the crosslinking rate is improved even if a crosslinking accelerator containing a halogen atom is not used in combination, it is possible to make the halogen content contained in the rubber composition of the present invention 0.1% by weight or less. The halogen component contained in the rubber composition of the present invention is used as a sample for analysis by combustion and decomposition of the rubber composition in a flask filled with oxygen, and the inorganic halogen component in the generated gas is absorbed by the absorption liquid in the flask, and the sample is used as a silver nitrate titration method and a potential difference. It can be quantified by a titration method, an ion chromatography method, or the like.

In addition to butyl rubber, resol-type phenol formaldehyde cocondensation resin, and specific phenols, the rubber composition of the present invention may contain additives conventionally blended with rubber. Examples of the additives include anti-aging agents, fillers such as carbon black, various inorganic fillers such as calcined clay, zincation, stearic acid, and oils. The rubber composition of the present invention may contain one or two or more additives.

The method for producing the rubber composition of the present invention may be a method of preparing a rubber composition by mixing a resol-type phenol formaldehyde cocondensation resin and a specific phenol with butyl rubber, respectively, or a resol-type phenol formaldehyde cocondensation resin and a specific phenol. After mixing in advance to form a resin mixture, the resin mixture and butyl rubber may be mixed to prepare a rubber composition. However, a resol-type phenol formaldehyde cocondensation resin and a specific phenol are premixed to form a resin mixture, and then the resin The method of mixing the mixture and the butyl rubber is preferable in that it is easy to uniformly disperse each component in the butyl rubber.

When the resol-type phenol formaldehyde cocondensation resin and specific phenols are mixed to form a resin mixture, the content ratio of the resol-type phenol formaldehyde cocondensation resin and the specific phenol in the resin mixture is 100 weight of the resol-type phenol formaldehyde cocondensation resin The specific phenols are usually 0.05 to 25 parts by weight, preferably 0.05 to 19 parts by weight, more preferably 0.15 to 19 parts by weight, based on parts.

The crosslinked rubber composition obtained by crosslinking the rubber composition of the present invention is obtained by crosslinking the rubber composition of the present invention described above. As a crosslinking method of the rubber composition of the present invention, for example, from molding processing to completion of crosslinking is carried out through a pressure press, or molding processing and primary crosslinking are carried out by a pressure press for, for example, 5 minutes to 15 minutes. Then, a method of performing secondary crosslinking in an oven or an electric furnace, for example, for 30 minutes to 4 hours, is exemplified. desirable.

The crosslinking temperature of the rubber composition of the present invention can be applied in the same temperature range as in the case of using a conventional resin crosslinking agent. Specifically, it is, for example, 130 to 230°C, preferably 160 to 210°C, and more preferably 180 to 200°C.

The crosslinked rubber composition obtained by crosslinking the rubber composition of the present invention can be used as various rubber products, and can be particularly preferably used as packings or O-rings.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In addition, the softening point of the resol-type phenol formaldehyde cocondensation resin described below is a value measured by a method conforming to JIS K2207.

1. Preparation of resol-type phenols formaldehyde cocondensation resin

<Production Example 1: Synthesis of Resin-1>

To a four-necked flask equipped with a reflux condenser and thermometer, p-tert-butylphenol 300 g (2.00 mol), 92 wt% paraformaldehyde 130 g (4.00 mol), 48 wt% sodium hydroxide aqueous solution 8.33 g (0.10 mol) And 150 g of toluene were added, and the inner temperature was raised to 65°C while stirring, followed by stirring at the same temperature for 1 hour, and further heating to 88°C, followed by stirring at the same temperature for 5 hours.

Then, it cooled to 65 degreeC, water 84g, toluene 90g, and 30 weight% sulfuric acid 16.4g were added, and after stirring, it left still and liquid-separated, and the toluene layer was obtained. After that, the toluene layer was washed with water 3 times.

Subsequently, the toluene layer containing the resin was concentrated under normal pressure for 1 hour until the internal temperature reached 118°C, and then concentrated under reduced pressure for 1 hour until the reduced pressure reached 90 torr and the internal temperature of 121°C, thereby resol-type p 368 g of -tert-butylphenol/formaldehyde cocondensation resin (resin-1) was obtained. The softening point of the obtained cocondensation resin was 110°C.

2. Preparation example of resin mixture of resol-type phenol formaldehyde cocondensation resin and specific phenol

<Example 1: Preparation of resin mixture A-1>

Takkyrol 201, a resol-type p-tert-octylphenol/formaldehyde cocondensation resin (softening point: 88° C., manufactured by Taoka Chemical Industries, Ltd., hereinafter sometimes referred to as resin 201) 50 g and 1,1,2, Put 4.0 g of 2-tetrakis (4-hydroxyphenyl) ethane (hereinafter sometimes referred to as THPE) in a mortar, mix it with a mortar at 25°C, and mix it with THPE. 54 g of resin mixture A-1 (THPE content 7.4 weight%) was obtained.

<Example 2: Preparation of resin mixture A-2>

In the same manner as in Example 1 except that 0.33 g of bisphenol A (hereinafter sometimes referred to as Bis-A) was used instead of 4.0 g of THPE, the resin mixture A-2 containing Bis-A (Bis-A content 0.66 wt%) 50.3 g was obtained.

<Example 3: Preparation of resin mixture A-3>

Except having used 4.0 g of Bis-A instead of 4.0 g of THPE, the same operation as in Example 1 was carried out to obtain 54 g of a resin mixture A-3 containing Bis-A (7.4% by weight of Bis-A content).

<Example 4: Preparation of resin mixture A-4>

In the same manner as in Example 1 except for using 0.17 g of bisphenol F (hereinafter, sometimes referred to as Bis-F) instead of 4.0 g of THPE, the resin mixture A-4 containing Bis-F (Bis-F content 0.33 wt%) 50.2 g was obtained.

<Example 5: Preparation of resin mixture A-5>

In the same manner as in Example 1 except that 0.33 g of Bis-F was used instead of 4.0 g of THPE, 50.3 g of a resin mixture A-5 containing Bis-F (Bis-F content 0.66% by weight) was obtained.

<Example 6: Preparation of resin mixture A-6>

Except having used 4.0 g of Bis-F instead of 4.0 g of THPE, the same operation as in Example 1 was carried out to obtain 54 g of a resin mixture A-6 containing Bis-F (7.4% by weight of Bis-F content).

<Example 7: Preparation of resin mixture A-7>

BIS-Z was prepared in the same manner as in Example 1 except that 0.17 g of 1,1-bis(4-hydroxyphenyl)cyclohexane (hereinafter, sometimes referred to as BIS-Z) was used instead of 4.0 g of THPE. 50.2 g of contained resin mixture A-7 (BIS-Z content 0.33 weight%) was obtained.

<Example 8: Preparation of resin mixture A-8>

Except having used BIS-Z 0.33g instead of THPE 4.0g, it operated similarly to Example 1, and obtained 50.3g of resin mixture A-8 (BIS-Z content 0.66 weight%) containing BIS-Z.

<Example 9: Preparation of resin mixture A-9>

Except having used 4.0 g of BIS-Z instead of 4.0 g of THPE, the same operation as in Example 1 was carried out to obtain 54 g of a resin mixture A-9 containing BIS-Z (7.4% by weight of BIS-Z content).

<Example 10: Preparation of resin mixture A-10>

In the same manner as in Example 1, except for using 0.17 g of tris(4-hydroxyphenyl)methane (hereinafter sometimes referred to as TPM) instead of 4.0 g of THPE, resin mixture A-10 containing TPM (TPM Content 0.33 wt%) 50.2 g was obtained.

<Example 11: Preparation of resin mixture A-11>

Except having used TPM 0.33g instead of THPE 4.0g, it operated similarly to Example 1, and obtained 50.3g of resin mixture A-11 (TPM content 0.66 weight%) containing TPM.

<Example 12: Preparation of resin mixture A-12>

Except having used TPM 4.0g instead of THPE 4.0g, it operated similarly to Example 1, and obtained 54 g of resin mixture A-12 (TPM content 7.4 weight%) containing TPM.

<Comparative Example 1: Preparation of resin mixture A-13>

In the same manner as in Example 1 except for using 4.0 g of resorcin (hereinafter sometimes referred to as RES) in place of THPE, 54 g of a resin mixture A-13 (RES content of 7.4% by weight) containing RES was obtained. .

<Comparative Example 2: Preparation of resin mixture A-14>

Except having used 4.0 g of phenol (hereinafter, sometimes referred to as Ph) in place of THPE, operation was carried out in the same manner as in Example 1 to obtain 54 g of a resin mixture A-14 (Ph content of 7.4% by weight) containing Ph.

<Comparative Example 3: Preparation of resin mixture A-15>

In the same manner as in Example 1 except that 4.0 g of p-cresol (hereinafter, may be referred to as p-Cr) was used instead of THPE, the resin mixture A-15 containing p-Cr (p-Cr content 7.4 Wt%) 54 g was obtained.

<Comparative Example 4: Preparation of resin mixture A-16>

In the same manner as in Example 1 except for using 4.0 g of maleic anhydride (hereinafter sometimes referred to as MA) instead of THPE, 54 g of a resin mixture A-16 (MA content of 7.4% by weight) containing MA was prepared. Got it.

<Example 13: Preparation of resin mixture B-1>

50 g of the resol-type p-tert-butylphenol/formaldehyde cocondensation resin (resin-1) prepared in Preparation Example 1 and 0.67 g of THPE were put in a mortar, and mixed at 25° C. while coarsely pulverized with a mortar, 50.7 g of a resin mixture B-1 (THPE content of 1.3% by weight) containing THPE was obtained.

<Example 14: Preparation of resin mixture B-2>

Except having set the amount of THPE to 2.5 g, it operated similarly to Example 13, and obtained the resin mixture B-2 (THPE content 4.8 weight%) 53 g containing THPE.

<Example 15: Preparation of resin mixture B-3>

A resin containing Bis-S in the same manner as in Example 13 except for using 2.5 g of bis(4-hydroxyphenyl)sulfone (bisphenol S (hereinafter, sometimes referred to as Bis-S)) instead of THPE 53 g of mixture B-3 (Bis-S content 4.8% by weight) was obtained.

3. Preparation of resol-type phenols formaldehyde cocondensation resin, and rubber composition containing specific phenols and evaluation of physical properties

<Example 16>

100 parts by weight of butyl rubber (polysubtil 402), 50 parts by weight of carbon black ("Cist S" (SRF grade) manufactured by Tokai Carbon Co., Ltd.), 50 parts by weight, zinc (Seido Chemical Co., Ltd. 2 types of zinc) 5 parts by weight A master batch rubber (256 g) containing 100 parts by weight of clay ("BURGESS KE" manufactured by Burgess Pigment) and 1 part by weight of stearic acid ("Beads stearic acid Tsubaki" manufactured by Nichiyu Corporation) was kept at 20°C. It was put into a 6-inch open roll manufactured by Kansai Roll Co., Ltd., and wound on a roll with a roll width of 2 mm. Thereafter, 16.2 g of the resin mixture A-1 (THPE content 7.4% by weight) prepared in Example 1 was added, and rewinding was performed three times. Next, it was set as the roll width of 0.25 mm, triangular passage was performed 10 times, and kneaded, and 272 g of a rubber composition was produced.

Next, the rubber composition was heated at 190° C. and under pressure to 6 MPa for 10 minutes to perform press molding. Next, the press-molded rubber sheet was placed in a vacuum oven heated at 190°C, and heated at 190°C for 150 minutes under a reduced pressure of 40 mmHg, thereby producing a crosslinked rubber composition (crosslinked rubber sheet) in which the rubber composition was crosslinked. I did.

The rubber composition and crosslinked rubber composition obtained by the above-described method were subjected to the tests described below. Table 1 shows the results.

<Examples 17 to 30, Reference Examples 1 and 2, and Comparative Examples 5 to 8>

In Example 16, the resin mixture to be used was the resin mixture shown in Tables 1 to 3 below, and the amount of the used resin mixture was also changed so that the amount of the cocondensed resin and additives shown in Tables 1 to 3 was changed. A rubber composition and a crosslinked rubber composition were produced by the same method as in 16, and the evaluation and measurement described below were performed. The results are shown in Tables 1-3. In addition, in Tables 1-3, the compounding amount of each component represents the compounding amount (part by weight) with respect to 100 parts by weight of butyl rubber. In addition, in Reference Examples 1 and 2, only Resin 201 (Reference Example 1) and Resin-1 (Reference Example 2) obtained in Production Example 1 were used instead of the resin mixture.

<Characteristic evaluation of rubber composition>

(1) crosslinking rate

The test was performed by a method conforming to JIS K6300-2: 2001. Specifically, the rubber composition was subjected to a rotational rheometer (vibration angle ±3.00°), and the rubber compositions obtained in Reference Examples 1 and 2 were respectively heated at 190° C. and 60 minutes to measure the change in torque, The maximum torque (MH (dN m)) of the rubber composition is read from the measured value, and the time to reach 10% and the time to 90% of the maximum torque value are calculated, respectively, and the vulcanization rate t(10) And t(90) was obtained. In addition, the vulcanization rates t(10) and t(90) for Examples 16 to 27 and Comparative Examples 5 to 8 are the time to reach 10% of the maximum torque value obtained in Reference Example 1, and the time to reach 90%. And the vulcanization rates t(10) and t(90) of Reference Example 2 and Examples 28 to 30 were taken as time to reach 10% of the maximum torque value obtained in Reference Example 2 and time to reach 90%. .

(2) Handling (appearance)

Visual observation of the presence or absence of rubber aggregates, foaming, or deformation (thinning, etc.) and contamination of the roll or mold on the rubber composition after kneading with a roll, crosslinked rubber sheet after press molding, and the surface of the roll and mold I did.

<Characteristic evaluation of crosslinked rubber composition>

(1) hardness

The test was conducted by a method conforming to JIS K6253 (type of testing machine: type A durometer, test temperature: 25°C).

(2) Tensile test

The test was performed by the method conforming to JIS K6251 (shape of test piece: dumbbell No. 3, tensile speed: 500 mm/min, test temperature: 25°C).

Specifically, a test piece was prepared from a crosslinked rubber sheet, and modulus M50 (MPa), M100 (MPa), breaking strength Tb (MPa), and breaking elongation Eb (%) were measured.

(3) SWELL test

One set of two test pieces produced by punching with a cutter from a crosslinked rubber sheet with a length of 50 mm × width 5 mm × thickness 2 mm, and immersed in toluene, respectively, the volume change rate and weight after immersion for 72 hours. The rate of change was measured and the average value was calculated.

<Evaluation of rubber composition and crosslinked rubber composition>

(1) About the evaluation value (numerical value)

About the evaluation values (numerical values) of each of the above evaluations, Examples 16 to 27 and Comparative Examples 5 to 8 were expressed as relative comparison values when the value of each test result obtained in Reference Example 1 was 100. Moreover, about Examples 28-30, it was shown by the relative comparison value when the value of each test result obtained in Reference Example 2 was set to 100.

(2) About relative evaluation

Tables 1 to 3 show the results of comparison and evaluation with the reference example by the following method for the five items of crosslinking rate, handling property, crosslinking density, dispersibility and moldability (Tb/Eb), swelling resistance and solvent resistance. . In addition, Examples 16 to 27 and Comparative Examples 5 to 8 were compared and evaluated with Reference Example 1 and Examples 28 to 30 with Reference Example 2.

(2-1) About evaluation of crosslinking rate

When t(10) representing the initial speed of crosslinking is 20 points or more smaller than each reference example, scorch (early crosslinking) may occur, so that the reduction of 20 points or more compared to each reference example is lower than that of each reference example. In addition, since t(90), which is the reference of the crosslinking end point, indicates that the smaller the value is crosslinked more quickly, the case where it is reduced by 5 points or more compared to each reference example is considered to be improved than each reference example. And, the case of an increase of 5 points or more was considered to be lower than each reference example. And, among these two evaluation values, when the result improved than each reference example was included: A, the case including the falling result: C, and other cases: B.

(2-2) Evaluation of handling properties

Visual observation of the presence or absence of rubber aggregates, foaming, or deformation (thinning, etc.) and contamination of the roll or mold on the rubber composition after kneading with a roll, crosslinked rubber sheet after press molding, and the surface of the roll and mold Thus, when agglomerates, foaming, deformation of rubber, or contamination of a roll or mold was confirmed: B, when not confirmed: A.

(2-3) About evaluation of crosslinking density

For hardness, M50, M100, and maximum torque (MH), when compared to each reference example, when increased by 3 points or more compared to each reference example, it is considered to be improved than each reference example, and when decreased by 3 points or more, each reference It is assumed that it is farther than the example, and the difference is within the range of ±2 points is equal to each reference example, and among the above four parameters, all parameters are improved compared to the reference example: A, when including a falling result: C, Other cases: It was set as B.

In addition, in Comparative Example 5, since the test piece was fractured before 50% elongation, M50 and M100 could not be measured, so it was set as-(blank), and it was judged to be equal to or less than that of Reference Example 1.

(2-4) Dispersibility, moldability (evaluation by Tb and Eb)

Resol-type phenols formaldehyde cocondensation resin in the rubber composition, dispersibility of phenols, and moldability of the rubber composition, during the tensile test, for Tb and Eb, respectively, compared to each reference example, the values of both are each reference example. In the case of a decrease of 5 points or more compared to, B was regarded as being inferior to each reference example, and in other cases, A was designated as equal to each reference example.

(2-5) Swelling resistance, solvent resistance

The volume change rate of the SWELL test (the difference in the volume of the rubber test piece before and after toluene immersion / the volume of the rubber test piece before toluene immersion) and the weight change rate (the difference in the weight of the rubber test piece before and after toluene immersion / the weight of the rubber test piece before toluene immersion) Compared to each reference example, when a certain value is increased by 4 points or more compared to each reference example, it is said to be lower than each reference example, C, and when both values are decreased by 4 points or more, it is said to be improved than each reference example. , In other cases, it was assumed to be equivalent to each reference example, and was referred to as B.

As shown in Tables 1 and 3, the rubber composition of the present invention containing resol-type alkylphenol-formaldehyde cocondensation resin and specific phenols uses only resol-type alkylphenol-formaldehyde cocondensation resin as a crosslinking agent. In contrast to the case (Reference Example 1, Reference Example 2), it was found that each of the above-described physical properties is improved.

In addition, the rubber composition containing phenols other than specific phenols, on the contrary, when using only resol-type alkylphenol-formaldehyde cocondensation resin as a crosslinking agent (Reference Example 1, Reference Example 2), the above-described physical properties It turned out that it deteriorates (Comparative Examples 5-8).

Claims (6)

As a rubber composition containing butyl rubber, resol-type phenols formaldehyde cocondensation resin, and phenols,
As the phenols, the following general formula (1):

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)
Compound represented by, the following general formula (2):

(In said general formula (2), n represents the integer of 1-9.)
Compound represented by, the following general formula (3):

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)
Compound represented by,
And
A rubber composition containing at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone. The method of claim 1,
A rubber composition comprising 8 to 20 parts by weight of resol-type phenols formaldehyde cocondensation resin and 0.01 to 2.0 parts by weight of phenols based on 100 parts by weight of butyl rubber. The method according to claim 1 or 2,
The rubber composition, wherein the content of the halogen atom contained in the rubber composition is 0.1% by weight or less. Resol-type phenols formaldehyde cocondensation resin and the following general formula (1):

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)
Compound represented by, the following general formula (2):

(In said general formula (2), n represents the integer of 1-9.)
Compound represented by, the following general formula (3):

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)
A compound represented by and at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone is mixed in advance to obtain a resin mixture, and the resin mixture and butyl rubber are mixed. The method for producing the rubber composition according to any one of claims 3. Resol-type phenols formaldehyde cocondensation resin,
The following general formula (1):

(In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may have a branch, a phenyl group, or a 4-hydroxyphenyl group.)
Compound represented by,
The following general formula (2):

(In said general formula (2), n represents the integer of 1-9.)
Compound represented by,
The following general formula (3):

(In the general formula (3), R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or 4-hydroxyphenyl group which may have a branch.)
Compound represented by,
And a resin mixture containing at least one phenol selected from the group consisting of bis(4-hydroxyphenyl)sulfone. A crosslinked rubber composition obtained by crosslinking the rubber composition according to any one of claims 1 to 3.