TW201943781A - Rubber composition containing butyl rubber, resol type phenol formaldehyde co-condensation resin, and phenol - Google Patents

Abstract

An object of the present invention is to provide a rubber composition which is capable of obtaining a sufficient crosslinking speed without using a compound or resin having a halogen atom or an organic acid as a crosslinking accelerator that may cause metal corrosion, when crosslinking butyl rubber with a resin crosslinking agent. The inventors found that by using a rubber composition containing a resol type phenol formaldehyde cocondensation resin and a phenol having a specific structure, it is possible to provide a rubber composition which can obtain a sufficient crosslinking rate without using a compound or resin having a halogen atom or an organic acid as a crosslinking accelerator that may cause metal corrosion.

Description

   Rubber composition containing butyl rubber, soluble phenol resin type phenol-formaldehyde co-condensation resin, and phenols   

The invention relates to a rubber composition comprising a butyl rubber, a soluble phenol resin type phenol formaldehyde co-condensation 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 suitable for various rubber products. However, a copolymer of a butyl rubber-based isobutylene and a small amount of isoprene has a small amount of unsaturated bonds that serve as a crosslinking point, and therefore has a low crosslinking speed, and there are limitations on applicable crosslinking methods.

The industrial butyl rubber crosslinking method is generally a method using a soluble phenol resin type phenolic formaldehyde co-condensation resin as a crosslinking agent.

On the other hand, when a butyl rubber is crosslinked by using a soluble phenol resin type phenolic formaldehyde co-condensation resin as a crosslinking agent, only the resin has a slow crosslinking speed. Therefore, especially when industrially implemented, halogenated elastomers such as tin chloride and ferric chloride, chlorinated rubber, and chlorosulfonated polyethylene are commonly used in combination with halogenated elastomers, organic acids, or halogenated alkyls. Cross-linking accelerators such as phenol / formaldehyde co-condensation resin.

However, when the compound or resin containing a halogen atom or an organic acid is used as a crosslinking accelerator, problems such as corrosion of a metal mold may occur during cross-linking molding of butyl rubber. Therefore, I am exploring ways to increase the crosslinking speed without using such a crosslinking accelerator.

For example, in Japanese Patent Application Laid-Open No. 2002-234968 (Patent Document 1), a mixture of a soluble phenol resin type phenol formaldehyde co-condensation resin and a novolac type phenol formaldehyde co-condensation resin is proposed as A proposal for a method of a resin cross-linking agent has been disclosed. According to this method, the cross-linking speed can be increased without using a compound or resin containing a halogen atom or an organic acid as a cross-linking accelerator.

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2002-234968

Then, when the present inventors verified the method described in Patent Document 1 again, they found that although the crosslinking speed was improved, the resin crosslinking agent described in the aforementioned Patent Document or the rubber composition containing the resin crosslinking agent ( The non-crosslinked rubber composition) has very high adhesiveness, and causes sticking or contamination to a manufacturing apparatus in a kneading step or a molding step, and thus it is determined that it is difficult to use the resin crosslinking agent in industry.

An object of the present invention is to provide a rubber composition (uncrosslinked rubber composition) which is used when a butyl rubber is crosslinked using a resin crosslinking agent, even if a halogen atom-containing compound or Resins or organic acids as crosslinking accelerators still have excellent crosslinking speed.

As a result of careful review by the present inventors in order to solve the aforementioned problems, it was found that a rubber composition containing a soluble phenol resin type phenol-formaldehyde co-condensation resin and a phenol having a specific structure can solve the aforementioned problems. Specifically, the present invention includes the following inventions.

[1]

A rubber composition comprising a butyl rubber, a soluble phenol resin type phenol-formaldehyde co-condensation resin, and phenols. The phenols include a compound represented by the following general formula (1), and At least one phenol in the group consisting of a compound represented by the formula (2), a compound represented by the following general formula (3), and bis (4-hydroxyphenyl) fluorene.

(上述通式(1)中，R₁及R₂表示氫原子、有分枝也可以的碳數1至4的烷基、苯基、或4-羥苯基)

(In the above-mentioned general formula (1), R ₁ and R ₂ represent a hydrogen atom, a branched alkyl group having 1 to 4 carbon atoms, a phenyl group, or a 4-hydroxyphenyl group)

(In the above general formula (2), n represents an integer of 1 to 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)

[2]

The rubber composition according to [1], which contains 8 to 20 parts by weight of a soluble phenol resin type phenol-formaldehyde co-condensation resin and 0.01 to 2.0 parts by weight of phenol based on 100 parts by weight of butyl rubber.

[3]

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

[4]

A method for producing a rubber composition according to any one of [1] to [3], which is a method in which a formaldehyde-like co-condensation resin containing a soluble phenol resin-type phenol is selected from At least one phenol in the group consisting of a compound represented by 1), a compound represented by the following general formula (2), a compound represented by the following general formula (3), and bis (4-hydroxyphenyl) fluorene in advance The resin mixture is obtained by mixing, and the resin mixture is mixed with butyl rubber.

(In the above 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)

(In the above general formula (2), n represents an integer of 1 to 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)

[5]

A resin mixture containing a soluble phenol resin type phenolic formaldehyde co-condensation resin, and a resin selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the following general formula (2), and At least one phenol in the group consisting of a compound represented by formula (3) and bis (4-hydroxyphenyl) fluorene.

(In the above 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)

(In the above general formula (2), n represents an integer of 1 to 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)

[6]

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

According to the present invention, it is possible to provide a rubber composition (uncrosslinked rubber composition) which is used when a butyl rubber is crosslinked using a resin crosslinking agent, even if halogen-containing Compounds or resins or organic acids as crosslinking accelerators also have excellent crosslinking speeds. Furthermore, the adhesiveness of the rubber composition of the present invention is appropriately controlled, and it is possible to avoid sticking or contamination of the manufacturing apparatus during the molding step.

Furthermore, the crosslinked rubber composition obtained by cross-linking the rubber composition of the present invention has improved cross-linking density, processability, and formability compared to the rubber composition cross-linked by a known method. In such a case, a crosslinked rubber composition excellent in swelling resistance and solvent resistance can be provided.

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

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

Examples of the soluble phenol resin type phenol-formaldehyde co-condensation resin contained in the rubber composition of the present invention include soluble phenol resin type phenol / formaldehyde co-condensation resin, soluble phenol resin type alkyl phenol / formaldehyde co-condensation resin, Soluble phenol resin type resorcinol / phenol / formaldehyde co-condensation resin, soluble phenol resin type resorcinol / cresol / formaldehyde co-condensation resin, etc. Among these co-condensation resins, from the viewpoint of compatibility with rubber, a resorcinol-type alkylphenol / formaldehyde co-condensation resin is preferable, and the alkyl group of the alkylphenol has 1 to 20 carbon atoms. Preferred is a soluble phenol resin type alkylphenol / formaldehyde co-condensation resin that may have a branched alkyl group. The alkylphenol group may have a branched alkyl group having 4 to 12 carbon atoms. Phenolic resin type alkylphenol / formaldehyde co-condensation resin is particularly preferable. The rubber composition of the present invention may contain one or two or more soluble phenol resin type phenol-formaldehyde co-condensation resins.

The softening point of the soluble phenolic resin-type phenolic formaldehyde co-condensation resin contained in the rubber composition of the present invention is generally 120 ° C or lower, preferably 80 to 110 ° C. It depends on the type of phenols that make up the co-condensation resin. However, by using a resin with a softening point of 120 ° C or lower, the dispersibility during the preparation of the rubber composition can be improved, so the temperature during rubber kneading can be reduced and it can be easier The rubber composition of the present invention is prepared.

Specific examples of the soluble phenol resin type phenol-formaldehyde co-condensation resin contained in the rubber composition of the present invention include, in addition to the resins produced in the examples described later, Tackirol 201 manufactured by Taoka Chemical Industry Co., Ltd. 2. Hitanol 2501 manufactured by Hitachi Chemical Industries, Ltd., SP-1044, SP-1045 manufactured by Schenectady International Inc., etc.

The rubber composition of the present invention preferably contains 8 to 20 parts by weight of a soluble phenol resin type phenol-formaldehyde co-condensation resin, and more preferably 10 to 18 parts by weight, based on 100 parts by weight of butyl rubber. By setting the content of the soluble phenol resin type phenolic formaldehyde co-condensation resin to 8 parts by weight or more, the crosslinking speed can be increased, and by setting the content to 20 parts by weight or less, unreacted (without participation) Crosslinked) co-condensation resin.

The rubber composition of the present invention is selected from the group consisting of a compound represented by the general formula (1), a compound represented by the general formula (2), a compound represented by the general formula (3), and bis (4-hydroxyphenyl). Among at least one phenol (hereinafter referred to as a specific phenol) in the group consisting of 碸, specific examples of the phenol represented by the general formula (1) include bisphenol A (2, 2 -Bis (4-hydroxyphenyl) propane), bisphenol F (4,4'-dihydroxydiphenylmethane), bisphenol B (2,2-bis (4-hydroxyphenyl) butane), bis Phenol 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; specific examples of the phenols represented by the general formula (2) include bisphenol Z (1,1-bis (4-hydroxyphenyl) cyclohexane), 1,1-bis (4-hydroxyphenyl) cyclododecane and the like; specific examples of the phenols represented by the general formula (3) include 1,2-bis (4-hydroxyphenyl) ethane, 1 , 1,2,2-tetrakis (4-hydroxyphenyl) ethane and the like. The rubber composition of the present invention may contain one or more specific phenols.

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

Since the rubber composition according to the present invention can improve the crosslinking speed even if a crosslinking accelerator containing a halogen atom is not used in combination, the halogen content contained in the rubber composition of the present invention can be made 0.1% by weight or less. The halogen content contained in the rubber composition of the present invention can be quantified as follows: The rubber composition is burned and decomposed in a flask filled with oxygen, so that the content of the inorganic halogen in the generated gas is absorbed into the absorption liquid in the flask. As an analysis sample, the sample was quantified by a silver nitrate titration method, a potential difference titration method, an ion chromatography method, or the like.

The rubber composition of the present invention may contain, in addition to butyl rubber, a soluble phenol resin type phenol-formaldehyde co-condensation resin, and specific phenols, additives that are usually formulated in rubber. Examples of the additives include anti-aging agents, fillers such as carbon black, various inorganic fillers such as calcined clay, zinc oxide, stearic acid, and oils. The rubber composition of the present invention may contain one kind or two or more kinds of additives.

The method for producing a rubber composition of the present invention may be a method for producing a rubber composition by mixing a soluble phenol resin type phenol-formaldehyde co-condensation resin and a specific phenol with a butyl rubber, respectively. A method for producing a rubber composition by mixing a resin phenol formaldehyde co-condensation resin and a specific phenol into a resin mixture in advance, and then mixing the resin mixture with butyl rubber. However, a soluble phenol resin type phenol formaldehyde is used. The method of mixing the co-condensation resin and the specific phenols into a resin mixture in advance, and then mixing the resin mixture and the butyl rubber is preferable because it is easy to uniformly disperse various components in the butyl rubber dispersion.

When a soluble phenol resin type phenol formaldehyde co-condensation resin and specific phenols are mixed into a resin mixture in advance, the content ratio of the soluble phenol resin type phenol formaldehyde co-condensation resin and specific phenols in the resin mixture is relative to the soluble content. The phenol resin type phenol-formaldehyde co-condensation resin is 100 parts by weight, and the specific phenol is usually 0.05 to 25 parts by weight, preferably 0.05 to 19 parts by weight, and more preferably 0.15 to 19 parts by weight.

The crosslinked rubber composition obtained by crosslinking the rubber composition of the present invention can be obtained by crosslinking the rubber composition of the present invention described above. The method of crosslinking the rubber composition of the present invention includes, for example, a method performed by a press from the molding process to the completion of the cross-linking; the molding process and the primary crosslinking are performed using the press for 5 minutes to 15 for example. Minutes, followed by a method of secondary crosslinking, such as 30 minutes to 4 hours, in an oven or an electric furnace, but from the viewpoint of productivity of the crosslinked rubber composition, the primary crosslinking and the secondary crosslinking are performed separately The method is better.

The crosslinking temperature of the rubber composition of the present invention can be applied to the same temperature range when a resin crosslinking agent is conventionally used. Specifically, for example, 130 to 230 ° C, preferably 160 to 210 ° C, and more preferably 180 to 200 ° C.

The crosslinked rubber composition obtained by cross-linking the rubber composition of the present invention can be used as various rubber products, and is particularly suitable for use as gaskets and O-rings.

    [Example]    

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples. The softening point of the following phenolic resin-type phenolic formaldehyde co-condensation resin is a value measured according to the method of JIS K2207.

    1. Manufacturing Example of Soluble Phenolic Formaldehyde Co-Condensation Resin         <Manufacturing Example 1: Synthesis of Resin-1>    

In a 4-neck flask equipped with a reflux cooler and a thermometer, 300 g of p-tert-butylphenol (2.00 mol), 130 g of 92% by weight paraformaldehyde (4.00 mol), and 8.33 g of a 48% by weight aqueous sodium hydroxide solution were added. (0.10 mol) and 150 g of toluene. After stirring, the temperature was raised to an internal temperature of 65 ° C., and then stirred at the same temperature for 1 hour, and then raised to 88 ° C., and then stirred at the same temperature for 5 hours.

Then, it cooled to 65 degreeC, 84g of water, 90g of toluene, and 16.4g of 30 weight% sulfuric acid were added, and after stirring, it stood still and separated, and the toluene layer was obtained. Thereafter, the toluene layer was washed with water three times.

Then, 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 degree of reduced pressure reached 90torr and the internal temperature reached 121 ° C to obtain a soluble phenol resin type. 368 g of p-third butylphenol / formaldehyde co-condensation resin (Resin-1). The softening point of the obtained co-condensation resin was 110 ° C.

    2. Examples of production of soluble phenol resin type phenol-formaldehyde co-condensation resin and resin mixture of specific phenols         <Example 1: Preparation of resin mixture A-1>    

50 g of Tachirol 201 (softening point: 88 ° C, manufactured by Taoka Chemical Industry Co., Ltd., hereinafter sometimes referred to as resin 201) and 1,1, which are Tachirol 201 which is a soluble phenol resin-type third octylphenol / formaldehyde cocondensation resin 4.0 g of 2,2-tetrakis (4-hydroxyphenyl) ethane (hereinafter sometimes referred to as THPE) was placed in a mortar and mixed at 25 ° C while coarsely crushed with a grinding rod to obtain THPE-containing 54 g of resin mixture A-1 (THPE content 7.4% by weight).

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

A Bis-A-containing resin mixture A-2 (Bis-A content 0.66 weight) was obtained 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 THPE. %) 50.3 g.

    <Example 3: Production of resin mixture A-3    

54 g of Bis-A-containing resin mixture A-3 (Bis-A content 7.4% by weight) was obtained in the same manner as in Example 1 except that Bis-A4.0 g was used instead of THPE 4.0 g.

    <Example 4: Production of resin mixture A-4    

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

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

50.3 g of Bis-F-containing resin mixture A-5 (Bis-F content 0.66% by weight) was obtained 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.

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

54 g of Bis-F-containing resin mixture A-6 (Bis-F content 7.4% by weight) was obtained in the same manner as in Example 1 except that 4.0 g of Bis-F was used instead of 4.0 g of THPE.

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

A BIS-Z-containing solution was obtained 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 resin mixture A-7 (BIS-Z content 0.33% by weight).

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

50.3 g of a BIS-Z-containing resin mixture A-8 (BIS-Z content 0.66 wt%) was obtained in the same manner as in Example 1 except that 0.33 g of BIS-Z was used instead of 4.0 g of THPE.

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

Except having used 4.0 g of BIS-Z instead of 4.0 g of THPE, it carried out similarly to Example 1, and obtained 54 g of resin mixture A-9 (BIS-Z content 7.4 weight%) containing BIS-Z.

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

A TPM-containing resin mixture A-10 (TPM 0.33% by weight) was obtained in the same manner as in Example 1 except that 0.17 g of tris (4-hydroxyphenyl) methane (hereinafter, sometimes referred to as TPM) was used instead of THPE. ) 50.2g.

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

Except that 0.33 g of TPM was used instead of 4.0 g of THPE, 50.3 g of a TPM-containing resin mixture A-11 (TPM content 0.66% by weight) was obtained in the same manner as in Example 1.

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

54 g of TPM-containing resin mixture A-12 (TPM content 7.4% by weight) was obtained in the same manner as in Example 1 except that 4.0 g of TPM was used instead of 4.0 g of THPE.

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

54 g of a RES-containing resin mixture A-13 (RES content: 7.4% by weight) was obtained in the same manner as in Example 1 except that 4.0 g of resorcinol (hereinafter sometimes referred to as RES) was used instead of THPE.

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

54 g of Ph-containing resin mixture A-14 (Ph content 7.4% by weight) was obtained in the same manner as in Example 1 except that 4.0 g of phenol (hereinafter, sometimes referred to as Ph) was used instead of THPE.

    <Comparative Example 3: Preparation of Resin Mixture A-15>    

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

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

54 g of MA-containing resin mixture A-16 (MA content 7.4% by weight) was obtained in the same manner as in Example 1 except that 4.0 g of maleic anhydride (hereinafter sometimes referred to as MA) was used instead of THPE.

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

50 g of a soluble phenolic resin-type p-third butylphenol / formaldehyde co-condensation resin (resin-1) manufactured in Production Example 1 and 0.67 g of THPE were placed in a mortar, and coarsely ground at 25 ° C with a grinding rod. It was crushed and mixed, and 50.7 g of THPE-containing resin mixture B-1 (THPE content 1.3% by weight) was obtained.

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

53 g of THPE-containing resin mixture B-2 (THPE content 4.8%) was obtained in the same manner as in Example 13 except that the amount of THPE used was set to 2.5 g.

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

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

    3. Manufacturing Examples and Physical Properties Evaluation of Rubber Compositions Containing Soluble Phenolic Formaldehyde Co-Condensation Resin and Specific Phenols         <Example 16>    

Contains 100 parts by weight of butyl rubber (Polysar butyl 402), 50 parts by weight of carbon black ("Seast S" (SRF grade) manufactured by Tokai Carbon Co., Ltd.), and zinc oxide (Zhengtong Chemical Industry Co., Ltd.) zinc oxide 2 Species) 5 parts by weight, 100 parts by weight of burnt clay ("BURGESS KE" manufactured by BURGESS PIGMENT) and 1 part by weight of stearic acid ("stealic acid camellia" manufactured by Nippon Oil Corporation) masterbatch rubber ) (256g), a 6-inch open roll made by Kansai Roll Co., Ltd. (Kansai Roll Co.), which is kept at 20 ° C, was rolled up with a roll width of 2 mm. Thereafter, 16.2 g of the resin mixture A-1 (THPE content 7.4% by weight) produced in Example 1 was added, and the inversion was performed three times. Next, a roll width of 0.25 mm was set, and a triangular roll was kneaded 10 times to produce 272 g of a rubber composition.

Then, the rubber composition was heated at 190 ° C and a pressure of 6 MPa for 10 minutes to perform pressure molding. Next, the press-molded rubber sheet was placed in a vacuum oven heated to 190 ° C, and heated at 190 ° C for 150 minutes under a reduced pressure of 40 mmHg to produce a cross-linking obtained by crosslinking the rubber composition. Rubber composition (crosslinked rubber sheet).

The following tests were performed on the rubber composition and the crosslinked rubber composition obtained by the above method. The results are shown in Table 1.

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

In Example 16, the resin mixtures shown in the following Tables 1 to 3 were used, and the amounts used were changed in addition to changing the blending amounts of the co-condensed resins and additives shown in Tables 1 to 3. A rubber composition and a crosslinked rubber composition were prepared by the same method as in Example 16, and the following evaluation measurements were performed. The results are shown in Tables 1 to 3. In Tables 1 to 3, the blending amount of each component represents the blending amount (parts by weight) with respect to 100 parts by weight of the butyl rubber. 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) Cross-linking speed    

The test was performed by a method according to JIS K6300-2: 2001. Specifically, the rubber composition was heated using a rotorless rheometer (vibration angle ± 3.00 °) while heating the rubber composition obtained in Reference Examples 1 and 2 at 190 ° C and 60 minutes, respectively. Measure the change in torque, read the maximum torque (MH (dN‧m)) of the rubber composition from the measured value, and calculate the time to reach 10% of the maximum torque value and the time to reach 90%, respectively, and The vulcanization rates t (10) and t (90) were obtained. The vulcanization speeds t (10) and t (90) of Examples 16 to 27 and Comparative Examples 5 to 8 were set to the time when 10% of the maximum torque value obtained in Reference Example 1 was reached, and Time; The vulcanization speeds t (10) and t (90) for Reference Example 2 and Examples 28 to 30 are set to the time to reach 10% of the maximum torque value obtained in Reference Example 2 and the time to reach 90% .

    (2) operability (appearance)    

Visually observe the presence or absence of rubber agglomerates, foaming, deformation (thinning, etc.) on the rubber composition after kneading with a roller, the crosslinked rubber sheet after pressure molding, and the surface of the roller and die, and the roller and The mold has no pollution.

    <Characteristic Evaluation of Crosslinked Rubber Composition>         (1) Hardness    

The test was performed by a method according to JIS K6253. (Type of testing machine: A-type hardness tester (Duromete), test temperature: 25 ° C)

    (2) Tensile test    

The test was performed by a method according to JIS K6251. (Shape of test piece: No. 3 dumbbell, Tensile speed: 500mm / min, Test temperature: 25 ° C)

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

    (3) Swelling test    

A test piece was prepared by cutting a cube of 50 mm in length × 5 mm in width × 2 mm in thickness from a crosslinked rubber sheet using a microtome. Two test pieces were used as a group and dipped in toluene, and the volume change rates after immersion for 72 hours were measured. And weight change rate, and calculate the average.

    <Evaluation of rubber composition and crosslinked rubber composition>         (1) Evaluation value (value)    

The evaluation values (numerical values) of the above-mentioned respective evaluations are expressed as relative comparison values when the value of each test result obtained in Reference Example 1 is 100 for Examples 16 to 27 and Comparative Examples 5 to 8. In addition, Examples 28 to 30 are expressed as relative comparison values when the value of each test result obtained in Reference Example 2 is 100.

    (2) About relative assessment    

For the five items of cross-linking speed, handling, cross-linking density, dispersibility / formability (Tb / Eb), swelling resistance / solvent resistance, the following methods are used to compare / evaluate the results with reference examples. Tables 1 to 3. In addition, Examples 16 to 27 and Comparative Examples 5 to 8 were compared / evaluated with Reference Example 1, and Examples 28 to 30 were compared / evaluated with Reference Example 2.

    (2-1) Evaluation of cross-linking speed    

When t (10), which indicates the initial speed of cross-linking, is more than 20 points lower than each reference example, there is a concern that coking (early cross-linking) may occur. Therefore, those who decrease by 20 points or more relative to each reference example are considered to be inferior to each reference example. Also, the smaller the t (90) value that becomes the end point standard of cross-linking means that the cross-linking is faster, so when it is reduced by 5 points or more relative to each reference example, it is better than the reference example, and when it is increased by 5 points or more, it is considered inferior In each reference example. Therefore, among these two kinds of evaluation values, it is rated as A when the result is superior to each reference example, it is rated as C when it contains a poor result, and it is rated as B if it is not the other.

    (2-2) Evaluation of operability    

Visually observe the presence or absence of rubber agglomerates, foaming, deformation (thinning, etc.) of the rubber composition and the crosslinked rubber sheet after pressure-molding, as well as the surface of the roller and the mold after the roll is kneaded, and the roller and the mold The presence or absence of contamination was evaluated as B when agglutination or foaming or deformation of the rubber was confirmed, or when the roller or mold was contaminated, and A when not confirmed.

    (2-3) Evaluation of crosslink density    

The hardness, M50, M100, and maximum torque (MH) are compared with each reference example, and when it is increased by more than 3 points relative to each reference example, it is better than each reference example, and when it is reduced by more than 3 points, it is inferior to each reference example. If the difference is within the range of ± 2 points, it is considered to be the same as the reference examples. Among the aforementioned four parameters, all parameters are better than the reference example and rated as A, if there is a poor result, it is rated as C, and otherwise it is rated as B.

In Comparative Example 5, the test piece was fractured before being stretched to 50%, and M50 and M100 could not be measured. Therefore, it was evaluated as-(blank), and it was judged to be equal to or lower than Reference Example 1.

    (2-4) Dispersibility and formability (evaluated by Tb, Eb)    

Aiming at the dispersibility of the soluble phenolic resin phenolic formaldehyde co-condensation resin and phenols in the rubber composition, and the moldability of the rubber composition, the tensile test, Tb and Eb were compared with each reference example, both When the value of the value is reduced by 5 points or more relative to each reference example, it is inferior to each reference example and is evaluated as B; otherwise, the value is equal to each reference example and is evaluated as A.

    (2-5) Swell resistance and solvent resistance    

Volume change rate (difference in volume of rubber test piece before and after toluene immersion / volume of rubber test piece before toluene immersion) and weight change rate (difference in weight of rubber test piece before and after toluene immersion / toluene immersion) The weight of the rubber test piece) was compared with each reference example. When any value was increased by 4 points or more relative to each reference example, it was inferior to the reference examples and evaluated as C. When the value of both sides was reduced by more than 4 points, it was excellent. It was rated as A in each reference example, and was otherwise rated as B in the same case as each reference example.

As shown in the above Tables 1 and 3, it can be seen that the soluble phenol resin type is included when compared with the case where only the soluble phenol resin type alkylphenol / formaldehyde cocondensation resin is used as the crosslinking agent (Reference Example 1, Reference Example 2). The alkylphenol / formaldehyde co-condensation resin and specific phenols of the rubber composition of the present invention are improved in each of the above physical properties.

On the contrary, it can be seen that the rubber composition containing phenols other than specific phenols is different from that when only a soluble phenol resin-type alkylphenol / formaldehyde co-condensation resin is used as a crosslinking agent (Reference Example 1, Reference Example 2). The physical properties described above are deteriorated (Comparative Examples 5 to 8).

Claims (6)

A rubber composition comprising a butyl rubber, a soluble phenol resin type phenol-formaldehyde co-condensation resin, and phenols. The rubber composition contains a compound selected from the group consisting of At least one phenol in the group consisting of the compound represented by the general formula (2), the compound represented by the following general formula (3), and bis (4-hydroxyphenyl) fluorene is the phenol,

In the above general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a 4-hydroxyphenyl group;

In the above general formula (2), n represents an integer of 1 to 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.     The rubber composition according to item 1 of the scope of the patent application, which contains 8 to 20 parts by weight of a soluble phenol resin type phenol formaldehyde co-condensation resin and 100 to 0.01 parts by weight of phenol based on 100 parts by weight of butyl rubber. Serving.         The rubber composition according to item 1 or item 2 of the scope of patent application, wherein the content of the halogen atom contained in the rubber composition is 0.1% by weight or less.     A method for manufacturing a rubber composition according to any one of claims 1 to 3 of the scope of patent application, which is a method in which a soluble phenol resin type phenol formaldehyde co-condensation resin is selected from the group consisting of the following general formula ( At least one phenol in the group consisting of a compound represented by 1), a compound represented by the following general formula (2), a compound represented by the following general formula (3), and bis (4-hydroxyphenyl) fluorene in advance Mixing to obtain a resin mixture, and then mixing the resin mixture with butyl rubber,

In the above general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a 4-hydroxyphenyl group;

In the above general formula (2), n represents an integer of 1 to 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. A resin mixture comprising a soluble phenol resin type phenolic formaldehyde co-condensation resin, and a compound selected from a compound represented by the following general formula (1), a compound represented by the following general formula (2), and the following general formula (3) at least one phenol in the group consisting of the compound represented by bis (4-hydroxyphenyl) fluorene,

In the above general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a 4-hydroxyphenyl group;

In the above general formula (2), n represents an integer of 1 to 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.     A crosslinked rubber composition obtained by crosslinking the rubber composition described in any one of items 1 to 3 of the scope of patent application.