JP2003138046A - Method for manufacturing rubber product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a rubber product, capable of stably developing the surface treatment effect exerted by a fluorine-based compound with the effect not destroyed or weakened through contact with various solvents. SOLUTION: The method includes a process for obtaining a molding of a crosslinked rubber through blending and kneading a rubber composition together with a 0.5-5 pts.mass of a silane coupling agent added to 100 pts.mass of the composition and molding it, a process for adhering to the surface of the molding a fluorine-based compound expressed by the formula (I) (wherein, RF is a group containing a fluoroalkyl group, R<1> is a functional group reactive with hydrolytic groups, R<2> is a hydrogen atom or an alkyl group, R<3> and R<4> are each a hydrogen atom or a univalent organic group, x is a 1-100 integer, and y is a 0-500 integer), and a process for heat-treating the molding with the specific fluorine- based compound adhering to its surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rubber product, and more specifically, a structure derived from a fluorine-based compound having a fluoroalkyl group-containing group at both ends of the molecule is present in the vicinity of the surface of a molded article. The present invention relates to a method for producing a rubber product which is securely bonded to a polymer main chain of a crosslinked rubber.

[0002]

2. Description of the Related Art Heretofore, there has been known a resin product surface-treated with a fluorine-based compound (oligomer) having fluoroalkyl groups at both ends of the molecule and having a functional group bonded to the intermediate chain. The fluorine-based compound applied to the surface treatment of such resin products has non-adhesiveness, surface lubricity, and water repellency because the fluoroalkyl groups at both ends of the molecule are bound to the intermediate chain through covalent bonds. The desired effects of the surface treatment such as imparting oil repellency, antifouling property, antibacterial property and physiological activity can be exhibited for a long period of time. Therefore, it is desirable to be able to produce a rubber product surface-treated with such a fluorine-based compound.

The following methods (1) and (2) have been introduced as a method for producing a resin product surface-treated with such a fluorine-based compound (a surface treatment method for a resin product). (1) A method of dissolving the fluorine-based compound together with a resin in an organic solvent, leaving the solvent for a certain period of time, and then removing the solvent (see JP-A No. 11-246573). (2) The fluorine-based compound is dissolved in a photopolymerizable monomer to prepare a photocurable composition, the composition is applied to the surface of a resin product (plastic), and the formed coating film is photocured. Method (see JP-A-10-245419).

[0004]

However, although the above methods (1) and (2) are suitable as a method for producing a resin product (a surface treatment method for a resin), these methods are applied to a rubber product. However, a rubber product having good surface characteristics could not be obtained. Therefore, the present inventors further tried the following methods (3) and (4).

(3) A molded body (rubber substrate) made of a crosslinked rubber is dipped in a solution of the fluorine-containing compound, dried and then heat-treated to form a film on the surface of the molded body. Method for forming (surface treatment layer). (4) A molded body (rubber substrate) made of uncrosslinked rubber is dipped in a solution of the fluorine-based compound, dried, and then heat-treated, whereby the rubber is crosslinked and the molded body concerned. A method of forming a coating film (surface treatment layer) on the surface of.

However, in the methods (3) and (4), the adhesion of the formed coating (surface treatment layer) to the molded body (rubber substrate) is small and the coating is easily peeled off. Not practical. Further, since the fluorine-based compound forming the coating is easily dissolved in various solvents, when the rubber product obtained by the method (3) or (4) is brought into contact with the solvent, the coating is corroded by the solvent.
It is melted and removed from the surface of the molded body.

The present invention has been made based on the above circumstances, and an object of the present invention is to have a group containing a fluoroalkyl group at both ends of the molecule and to which a functional group is bonded to the intermediate chain. The structure derived from the fluorinated compound can be reliably and efficiently bonded to the polymer main chain of the crosslinked rubber in the vicinity of the surface of the molded body, and the surface treatment effect of the fluorinated compound can be changed with various solvents. It is an object of the present invention to provide a method capable of producing a rubber product that can be stably expressed without being extinguished or diminished by contact.

[0008]

The method for producing a rubber product of the present invention comprises a rubber composition prepared by mixing and kneading 0.5 to 5 parts by mass of a silane coupling agent with respect to 100 parts by mass of a raw rubber. A step of obtaining a molded product made of a crosslinked rubber by molding, and a fluorine-based compound represented by the following general formula (I) on the surface of this molded product (hereinafter, also referred to as "specific fluorine-based compound"). And a step of heat-treating the molded body having the specific fluorine-based compound attached to its surface.

[0009]

[Chemical 3]

(Wherein R _F is a group containing a fluoroalkyl group, R ¹ is a functional group reactive with a hydrolyzable group, R ² is a hydrogen atom or an alkyl group, R ³ and R ^3
4 represents the same or different, a hydrogen atom or a monovalent organic group. x is an integer of 1 to 100 and y is 0 to 500
Is an integer. )

In the rubber product manufacturing method of the present invention,
The following forms are preferred. [1] Dissolution of a specific fluorine-based compound on the surface of the molded body
By applying a liquid, the fluorine-based compound
Attach to the surface of the feature. [2] The molded body is placed in a solution of a specific fluorine compound.
By dipping, the fluorine-based compound
Adhere to the surface of. [3] In the above general formula (I) showing a specific fluorine compound
By the way, R¹The functional group represented by
Or an alkoxyalkoxysilyl group. [4] In the above general formula (I) showing a specific fluorine compound
By the way, R¹The functional group represented by is a trimethoxysilyl group
To be. [5] In the above general formula (I) showing a specific fluorine compound,
By the way, R_FContains a fluoroalkyl group represented by
The group is -CF₃, -C₂F_Five, -C₃F₇, -C
₆F₁₃, -C₇F₁₅Or -CF (CF₃) [OCF₂
CF (CF₃)]_pOC ₃F₇(Where p is 0, 1
Is 2). [6] A specific fluorine compound is represented by the following formula (1)
Be a compound that [7] Reactive organic compound contained in the silane coupling agent
The functional group is a mercapto group or a vinyl group.

[0012]

[Chemical 4]

(In the formula, x'is 2 or 3.)

[0014]

[Function] By crosslinking the rubber in the presence of the silane coupling agent, a reaction between the reactive organic functional group of the silane coupling agent and the polymer main chain of the rubber occurs together with the crosslinking reaction. A crosslinked rubber having a silane coupling agent bonded to the polymer main chain is obtained.
And, after adhering a specific fluorine-based compound on the surface of the molded body made of this crosslinked rubber, by heat-treating the molded body, in the vicinity of the surface of the molded body, the functionality of the specific fluorine-based compound is The group (R ¹ ) reacts with the hydrolyzable group of the silane coupling agent bonded to the polymer main chain. As a result, a structure derived from a specific fluorine-based compound can be bonded to the polymer main chain of the crosslinked rubber near the surface of the molded body via the silane coupling agent.

As described above, a chemical bond is formed between the structure derived from the specific fluorine compound and the silane coupling agent, and between the silane coupling agent and the polymer main chain of the crosslinked rubber. Therefore, the structure (surface treatment layer) derived from the specific fluorine-based compound firmly adheres to the surface of the molded body that is the rubber base material. Furthermore, the hybrid formed by the reaction between the functional group of the specific fluorine-based compound and the hydrolyzable group of the silane coupling agent is excellent in thermal stability and chemical stability, On the other hand, it becomes insoluble or hardly soluble even in various solvents that are good solvents, so that the chemical resistance (oil resistance / solvent resistance) of the obtained rubber product can be markedly improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the method for producing a rubber product of the present invention, a step of obtaining a molded article made of a crosslinked rubber by molding a rubber composition obtained by mixing and kneading a silane coupling agent (hereinafter, also referred to as "molding step"). ) And a step of attaching a specific fluorine compound to the surface of the molded body (hereinafter,
It is also referred to as "a step of attaching a fluorine compound". ) And a step (hereinafter, also referred to as “heating step”) of heat-treating the molded body having a specific fluorine compound attached to the surface thereof.

<Molding Step> The molding step in the production method of the present invention is a step of molding a rubber composition obtained by mixing and kneading a silane coupling agent to obtain a molded article made of a crosslinked rubber. Here, "molding" means obtaining a shape of a rubber product and crosslinking the rubber.

The rubber (raw material rubber constituting the rubber composition) used in the manufacturing method of the present invention is not particularly limited, and natural rubber (NR) and isoprene rubber (I
R), butadiene rubber (BR), chloroprene rubber (C
R), butyl rubber (IIR), styrene butadiene rubber (SBR), nitrile rubber (NBR), ethylene propylene rubber (EPM, EPDM), acrylic rubber (AC
M, ANM), epichlorohydrin rubber (CO, EC
O), silicone rubber (VMQ, FVMQ), urethane rubber (AU, EU), fluororubber (FKM, FEPM)
And the like.

The silane coupling agent (constituent component of the rubber composition) used in the production method of the present invention contains a hydrolyzable group and a reactive organic functional group in one molecule, and contains a specific fluorine compound and a cross-linking agent. It reacts with each of the polymer main chains of the rubber to form a strong chemical bond between them. Examples of such a silane coupling agent include those represented by the following general formula (II).

[0020]

[Chemical 5]

In the above general formula (II) representing the silane coupling agent, R ⁵ represents an alkyl group or an alkoxyalkyl group, and R ⁶ represents an alkyl group. Also, m
Is an integer of 1 to 3, preferably 3, and n is an integer of 0 to 5, preferably 0 to 3.

By reacting the hydrolyzable group [Si (OR ⁵ ) _m R ⁶ _3-m −] contained in the silane coupling agent with the functional group (R ¹ ) contained in the specific fluorine compound, heat is generated. Hybrids with excellent stability and chemical stability are formed. Examples of such a hydrolyzable group include an alkoxysilyl group such as a trimethoxysilyl group.

In the above general formula (II) representing the silane coupling agent, R ⁷ represents an organic functional group having reactivity with the polymer main chain of rubber. Examples of the reactive organic functional group (R ⁷ ) include an amino group, a mercapto group, a vinyl group, a (meth) acryloyloxy group, an epoxy group, and a ureido group. Among these, a mercapto group having reactivity with the polymer main chain of the rubber having an unsaturated bond, a vinyl group having reactivity with the polymer main chain of the rubber having no unsaturated bond, and the like are preferable. Can be mentioned. As described above, by selecting the reactive organic functional group (R ⁷ ) depending on the type of rubber (whether or not there is an unsaturated bond in the polymer main chain), a compound of the same type as a specific fluorine-based compound can be obtained. Can be used for various rubbers.

The compounding amount of the silane coupling agent in the rubber composition varies depending on the amount of the filler compounded in the rubber composition.
The amount is 0.5 to 5 parts by mass, preferably 0.5 to 2 parts by mass, and particularly preferably 0.75 to 2 parts by mass per 00 parts by mass. When the compounding amount of the silane coupling agent is less than 0.5 part by mass, the structure derived from the specific fluorine-based compound cannot be efficiently bonded to the polymer main chain of the crosslinked rubber, and the desired structure cannot be obtained. The treatment effect cannot be imparted to the surface of the molded body. On the other hand, even if it exceeds 5 parts by mass,
It is not possible to obtain the effect of matching the blending amount.

In the rubber composition containing the raw material rubber and the silane coupling agent as essential components, a crosslinking agent, a crosslinking accelerator,
Various conventionally known compounding agents for rubber such as an anti-aging agent, a filler and a plasticizer may be contained. The kneading method for obtaining the rubber composition is not particularly limited, either.
A conventionally known method using a kneader can be adopted.

The molding method is not particularly limited, and a conventionally known method (for example, press molding) for obtaining a molded product made of a crosslinked rubber can be adopted. Here, as the rubber crosslinking conditions, for example, 140 to
It is set to 180 ° C. for 5 to 60 minutes.

In the molding step in the manufacturing method of the present invention,
By crosslinking the rubber in the presence of the silane coupling agent, a reaction between the reactive organic functional group possessed by the silane coupling agent and the polymer main chain of the rubber occurs together with the crosslinking reaction. A crosslinked rubber in which a ring agent is bonded to the polymer main chain is obtained.

<Fluorine-Based Compound Adhesion Step> In the production method of the present invention, the fluorine-based compound adhesion step is a molding (rubber substrate) made of the crosslinked rubber obtained in the above molding step.
Is a step of adhering a specific fluorine compound to the surface of.

The specific fluorine compound used in the production method of the present invention is a group (R _F ) containing a fluoroalkyl group.
Having a functional group (R ¹ ) having reactivity with a hydrolyzable group in the intermediate chain, having a molecular weight of 500 to 5
It is about 50,000 fluorine-based oligomers.

Fluoro that constitutes a specific fluorine-based compound
A group containing an alkyl group (R_F), A specific example of
CF₃, -C₂F_Five, -C₃F₇, -C₆F₁₃And −
C₇F₁₅-C_qF_{2q + 1}Represented by (q = 1 to 10)
Fluoroalkyl group; -CF (CF₃) OC₃F₇,-
CF (CF₃) [OCF₂CF (CF₃)] OC
₃F ₇, And -CF (CF₃) [OCF₂CF (CF
₃)]₂OC₃F₇A group represented by (oxyfluoroar
Examples of groups containing a xylene group and a fluoroalkyl group)
Of these, -CF (CF₃) O
C₃F₇The group represented by is particularly preferable.

The functional group (R ¹ ) constituting the specific fluorine-based compound has reactivity with the hydrolyzable group, whereby the bond with the silane coupling agent is secured. Examples of the functional group (R ¹ ) include alkoxysilyl groups such as trimethoxysilyl group and triethoxysilyl group; tri (methoxymethoxy) silyl group, tri (methoxyethoxy) silyl group, tri (ethoxymethoxy) silyl group, tri Alkoxyalkoxysilyl groups such as (ethoxyethoxy) silyl groups can be mentioned. Of these, an alkoxysilyl group is preferable, and a trimethoxysilyl group is particularly preferable. The group (R ² ) constituting the specific fluorine compound is a hydrogen atom or an alkyl group such as a methyl group.

The groups (R ³ , R ⁴ ) constituting the specific fluorine compound are the same or different groups and are hydrogen atoms or monovalent organic groups, and have a function to be imparted to the surface of the rubber. An appropriate group can be selected accordingly.
The organic group represented by R ³ or R ⁴ includes the following (i)
The groups shown in to (v) can be mentioned.

[0033]

[Chemical 6]

In the above general formula (I) showing a specific fluorine compound, x is an integer of 1 to 100, preferably 1 to 50, more preferably 1 to 10, and particularly preferably 1 to 5. To be done. Further, y is an integer of 0 to 500, preferably 0 to 100, more preferably 0 to 5
0, particularly preferably 0-10, most preferably 0-5.

The specific fluorine compound represented by the above general formula (I) is a monomer represented by the following general formula (IB) in the presence of a fluorine-containing peroxide represented by the following general formula (IA). And a monomer represented by the following general formula (IC) are polymerized.

[0036]

[Chemical 7]

Suitable compounds constituting the specific fluorine compound include compounds represented by the above formula (1) and compounds represented by the following formulas (2) to (5). In particular, the compounds represented by the above formula (1) and the following formula (2) have a large proportion of fluorine atoms (atoms contributing to the improvement of surface characteristics) in one molecule, so that the molded product (rubber substrate) It is preferable because fluorine atoms can be present on the surface of the with high efficiency.

[0038]

[Chemical 8]

[In the formulas (2) and (3),
R _F 'is of the formula: -CF (CF ₃ ) OCF ₂ CF (C
F ₃₎ a group represented by OC ₃ F _7. In formula (2), x
a is an integer of 1 to 100. In the formula (3), xb is 1 to
An integer of 100 and yb are integers of 1 to 500. ]

[0040]

[Chemical 9]

[In the formula (4), xc is an integer of 1 to 10, and y is
c is an integer of 0-100. In the formula (5), xd is 1 to
The integer of 10 and yd are the integers of 0-100. ]

In the production method of the present invention (step of attaching a fluorine-based compound), a molded article (rubber substrate) made of crosslinked rubber
As a method of adhering the specific fluorine-based compound to the surface of the, there is a method of dissolving the specific fluorine-based compound in an appropriate solvent to prepare a solution and applying the solution to the surface of the molded body. it can. Here, as the solvent for dissolving the specific fluorine-based compound, water, methanol, ethanol, tetrahydrofuran, chloroform, benzene, ethyl acetate, dimethylsulfoxide (DMSO), N, N
-Dimethylformamide (DMF), toluene, acetone, hexane, and alternative CFCs (HCFC-based, HFC-based, PFC-based) used for applications such as precision cleaning.

The solution of the specific fluorine compound is preferably acidic or alkaline, and is acidic (pH
Is particularly preferably 6 or less, particularly 3 to 5). As a result, the reaction between the functional group (R ¹ ) of the specific fluorine-based compound and the hydrolyzable group of the silane coupling agent is efficiently performed, and the formation of hybrids is promoted. Examples of the acid added to make these solutions acidic include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; organic acids such as formic acid, acetic acid, propionic acid, butanoic acid, and pentanoic acid. Of these, acetic acid is preferred.
As a method of applying a solution of a specific fluorine-based compound,
Although not particularly limited, a method of immersing the molded body in the solution (immersion method) is preferable. As a coating method for a large molded body having a wide coating area, a brush coating method, a spraying / spraying method, a method using various coaters, or the like can be adopted.

<Heating Step> The heating step in the manufacturing method of the present invention is a step of heat-treating the molded body having the specific fluorine compound attached to the surface thereof. Here, the heating conditions are defined from the viewpoint of allowing the condensation reaction between the specific fluorine compound and the silane coupling agent to proceed sufficiently. Specifically, it is set to 70 to 180 ° C. for 5 to 60 minutes. As the heat treatment method, a method using a constant temperature bath having a ventilation function is preferable.

By the heat treatment, in the vicinity of the surface of the molded body (rubber substrate), the hydrolyzable group contained in the silane coupling agent bonded to the polymer main chain and the specific fluorine compound are added. Reacts with the functional group (R ¹ ) possessed by to form a hybrid (a hybrid of a specific fluorine compound-silane coupling agent) excellent in thermal stability and chemical stability. Thereby, the structure derived from the specific fluorine-based compound can be bonded to the polymer main chain of the crosslinked rubber near the surface of the molded body via the silane coupling agent.

The following formula (6) is obtained by hydrolyzing the specific fluorine compound represented by the above formula (1) and the above general formula (I).
Silane coupling agent represented by I) (however, m = 3)
2 shows an example of a hybrid structure having a siloxane bond, which is formed by a condensation reaction with a hydrolyzate of the above.
In the following formula (6), the bonding state between the silane coupling agent and the polymer main chain is not shown, but in the rubber product obtained by the manufacturing method of the present invention, in practice,
The silane coupling agent is bonded to the polymer main chain of rubber by an organic functional group (R ⁷ ).

[0047]

[Chemical 10]

Through each of the above steps (molding step, fluorine compound attaching step, heating step), a specific fluorine compound is added to the polymer main chain of the crosslinked rubber in the vicinity of the surface of the molded article via a silane coupling agent. A rubber product (surface-treated rubber product) obtained by combining the structures derived from is obtained. In the rubber product thus obtained, a chemical bond is formed between the structure derived from the specific fluorine compound and the silane coupling agent, and between the silane coupling agent and the polymer main chain of the crosslinked rubber. Therefore, the structure (surface treatment layer) derived from the specific fluorine compound firmly adheres to the surface of the molded body. Furthermore, a functional group (R ¹ ) possessed by a specific fluorine-based compound,
The hybrid formed by the reaction with the hydrolyzable group possessed by the silane coupling agent is excellent in thermal stability and chemical stability, and even in various solvents which are good solvents for a specific fluorine compound. Since it becomes insoluble or sparingly soluble, the chemical resistance (oil resistance / solvent resistance) of the rubber product can be significantly improved. The shape of the rubber product obtained by the manufacturing method of the present invention is not particularly limited. In addition, the rubber product obtained by the manufacturing method of the present invention includes one in which some of the constituent members are made of rubber.

The rubber products obtained by the production method of the present invention include belts, pulleys, hoses, tubes, gaskets, O-rings, packings, diaphragms, wipers, rolls, cables, cushion pads, printing blankets (particularly surface layers), It can be used as a grommet, various sealing materials and various sheet materials.

[0050]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these. In the following, “part” means “part by mass”.

Preparation Example 1 95% by volume of ethanol and 5 parts of water
After adding 2 drops of acetic acid to about 100 mL of a mixed solvent consisting of volume%, the specific fluorine-based compound represented by the formula (1) is added to the mixed solvent, and the concentration of the fluorine-based compound is 1% by mass. The treatment liquid of was prepared.

Preparation Example 2 HCFC-225ca (CF
₃ CF ₂ CHCl ₂ ) and HCFC-225cb (CC
1F ₂ CF ₂ CHClF) mixed solvent “Asahi Kulin AK-225” (Asahi Glass Co., Ltd.) (about 100 mL), 2 drops of acetic acid were added to the mixed solvent, and then the specific solvent represented by the formula (2) was used. A fluorine-based compound (however, xa = 2 to 3) was added and uniformly dispersed to prepare a treatment liquid having a concentration of the fluorine-based compound of 1% by mass.

Preparation Example 3 95% by volume of methanol and 5 parts of water
After adding 2 drops of acetic acid to about 100 mL of a mixed solvent consisting of volume%, the specific fluorine compound represented by the above formula (3) (where xb = 1 to 10 and yb = 1 is added to the mixed solvent.
˜100) was added to prepare a treatment liquid having a concentration of the fluorine-based compound of 1% by mass.

<Example 1> [1] Molding step: Nitrile rubber "Nipol DN401" (Nippon Zeon Co., Ltd.) was used according to the formulation shown in Table 1 below.
Made, AN amount = 18%), 100 parts of sulfur, 1 part of sulfur, 5 parts of zinc oxide, 1 part of cross-linking accelerator "NOXCELLER ZTC" (manufactured by Ouchi Shinko Chemical Co., Ltd.), and cross-linking accelerator "NOXCELLER TOT".
-N "(manufactured by Ouchi Shinko Chemical Co., Ltd.) and 4 parts of crosslinking accelerator" NOXCELLER DM "(manufactured by Ouchi Shinko Chemical Co., Ltd.)
_{Formula: Si (OCH 3) 3 -} (CH 2) 3 -SH with a silane coupling agent represented "A-189" [manufactured by Nippon Unicar Co., Ltd.] nitrile rubber composition was kneaded by 1 part 8 inch roll An uncrosslinked rubber sheet made of a material was prepared, and the uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet (molded product as a rubber base material).

[2] Adhesion step of fluorinated compound: The crosslinked rubber sheet obtained by the above-mentioned molding step was prepared as in Preparation Example 1.
After being immersed in the treatment liquid obtained in step 3 for 30 minutes, the crosslinked rubber sheet was dried at room temperature to remove the mixed solvent, thereby adhering a specific fluorine compound to the surface of the crosslinked rubber sheet.

[3] Heating step: The crosslinked rubber sheet having a specific fluorine compound adhered to the surface thereof by the above fluorine compound adhesion step is placed in a thermostatic chamber (150 ° C.) having a ventilation function for 10 minutes. By heat treatment for minutes, a crosslinked rubber sheet (rubber product) surface-treated with the specific fluorine compound represented by the above formula (1) was produced.

Example 2 According to the formulation shown in Table 1 below, each component was kneaded in the same manner as in the molding process of Example 1 except that the compounding amount of the silane coupling agent was changed to 2 parts. An uncrosslinked rubber sheet made of a nitrile rubber composition was prepared, and this uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the obtained crosslinked rubber sheet is immersed in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, thereby the crosslinked rubber sheet. A specific fluorine compound was attached to the surface of the. Then, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes, so that the crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (1) is obtained. (Rubber product) was manufactured.

Example 3 An uncrosslinked rubber sheet made of a nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 according to the formulation shown in Table 1 below. Crosslinked rubber sheet at 150 ℃ 10
A crosslinked rubber sheet was produced by press molding for minutes. Then, this crosslinked rubber sheet was immersed in the treatment liquid obtained in Preparation Example 2 for 30 minutes, and then the crosslinked rubber sheet was dried at room temperature to remove the mixed solvent.
A specific fluorine compound was attached to the surface of the crosslinked rubber sheet. Then, in the same manner as in the heating step of Example 1,
By subjecting the crosslinked rubber sheet to heat treatment at 150 ° C. for 10 minutes, a crosslinked rubber sheet surface-treated with the specific fluorine-containing compound represented by the above formula (2) (rubber product)
Was manufactured.

Example 4 According to the formulation shown in Table 1 below, each component was kneaded in the same manner as in the molding step of Example 1 except that the compounding amount of the silane coupling agent was changed to 2 parts. An uncrosslinked rubber sheet made of a nitrile rubber composition was prepared, and this uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the crosslinked rubber sheet is immersed in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, thereby the surface of the crosslinked rubber sheet. A specific fluorine-based compound was attached to. Then, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes, so that the crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (2) is obtained. (Rubber product) was manufactured.

Example 5 An uncrosslinked rubber sheet made of a nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 according to the formulation shown in Table 1 below. Crosslinked rubber sheet at 150 ℃ 10
A crosslinked rubber sheet was produced by press molding for minutes. Then, the crosslinked rubber sheet was immersed in the treatment liquid obtained in Preparation Example 3 for 30 minutes, and then the crosslinked rubber sheet was dried at room temperature to remove the mixed solvent.
A specific fluorine compound was attached to the surface of the crosslinked rubber sheet. Then, in the same manner as in the heating step of Example 1,
By subjecting the crosslinked rubber sheet to a heat treatment at 150 ° C. for 10 minutes, a crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (3) (rubber product)
Was manufactured.

Example 6 According to the formulation shown in Table 1 below, each component was kneaded in the same manner as in the molding process of Example 1 except that the compounding amount of the silane coupling agent was changed to 2 parts. An uncrosslinked rubber sheet made of a nitrile rubber composition was prepared, and this uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the crosslinked rubber sheet is immersed in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, thereby the surface of the crosslinked rubber sheet. A specific fluorine-based compound was attached to. Thereafter, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes to give a crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (3). (Rubber product) was manufactured.

Comparative Example 1 A nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 except that the silane coupling agent was not blended according to the formulation shown in Table 1 below. A crosslinked rubber sheet (comparative rubber product) was manufactured by producing an uncrosslinked rubber sheet consisting of and press-molding the uncrosslinked rubber sheet at 150 ° C. for 10 minutes.

Comparative Example 2 A nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 except that the silane coupling agent was not blended according to the formulation shown in Table 1 below. An uncrosslinked rubber sheet made of was prepared, and the uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the obtained crosslinked rubber sheet is immersed in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, thereby the crosslinked rubber sheet. A specific fluorine compound was attached to the surface of the. Then, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes, so that the crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (1) is obtained. (Rubber product for comparison) was manufactured.

Comparative Example 3 A nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 except that the silane coupling agent was not blended according to the formulation shown in Table 1 below. An uncrosslinked rubber sheet made of was prepared, and the uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the obtained crosslinked rubber sheet is dipped in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, whereby the crosslinked rubber sheet is obtained. A specific fluorine compound was attached to the surface of the. Then, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes, so that the crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (2) is obtained. (Rubber product for comparison) was manufactured.

Comparative Example 4 A nitrile rubber composition was prepared by kneading each component in the same manner as in the molding process of Example 1 except that the silane coupling agent was not blended according to the formulation shown in Table 1 below. An uncrosslinked rubber sheet made of was prepared, and the uncrosslinked rubber sheet was press-molded at 150 ° C. for 10 minutes to prepare a crosslinked rubber sheet. Then, the obtained crosslinked rubber sheet is immersed in the treatment liquid obtained in Preparation Example 30 for 30 minutes, and then the crosslinked rubber sheet is dried at room temperature to remove the mixed solvent, thereby the crosslinked rubber sheet. A specific fluorine compound was attached to the surface of the. Thereafter, in the same manner as in the heating step of Example 1, the crosslinked rubber sheet is heat-treated at 150 ° C. for 10 minutes to give a crosslinked rubber sheet surface-treated with the specific fluorine compound represented by the above formula (3). (Rubber product for comparison) was manufactured.

<Evaluation of Sheet> X was applied to each of the crosslinked rubber sheets obtained in Examples 1 to 6 and Comparative Examples 1 to 4.
The amount of fluorine atoms present on the surface of the sheet (the number of fluorine atoms per carbon atom) was measured by a line photoelectron spectroscopy analyzer (XPS). It can be said that the larger the existing amount, the more excellent the surface properties such as water repellency and oil repellency. The results are shown in Table 1 below. The measurement conditions are as follows.

(Measurement conditions) -Model used: Perkin Elmer PHI 56
00 ESCA System, ・ Indoor pressure (pressure reduction condition): 2.8 × 10 ^-7 Pa, ・ Correction: C1s is corrected to 285.0 eV by neutralizing gun, ・ X-ray: AlKα monochrome X-ray, ・ X-ray Irradiation angle: 45 ° to 55 °, measurement area: 800 μm × 2000 μm

Further, with respect to each of the crosslinked rubber sheets obtained in Examples 1 to 6 and Comparative Examples 1 to 4, contact treatment with each solvent shown in Table 1 below (Soxhlet extraction, extraction time =
After 12 hours), the amount of fluorine atoms present on the surface of the sheet was measured again to obtain the retention rate before extraction (initial value). If the retention rate is 90% or more, it can be said that even if the solvent is brought into contact with the solvent, the desired surface characteristics exhibited by the surface-treated layer of the crosslinked rubber sheet are not lost or diminished. The results are also shown in Table 1 below.

[0069]

[Table 1]

[0070]

According to the production method of the present invention, a structure derived from a specific fluorine-based compound can be reliably and efficiently bonded to the polymer main chain of the crosslinked rubber in the vicinity of the surface of the molded article. As a result, it is possible to reliably produce a rubber product that exhibits stability without the surface treatment effect of a specific fluorine-based compound being extinguished or diminished by contact with various solvents. Further, by selecting the reactive organic functional group of the silane coupling agent according to the type of raw rubber, it is possible to use the same type of compound as a specific fluorine compound for various rubbers. Become.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F006 AA04 AB19 AB63 AB67 BA04                       DA04                 4J002 AC011 AC031 AC061 AC071                       AC081 AC091 BB151 BB181                       BD121 CH041 CK021 CP031                       EX036 FD206

Claims (8)

[Claims] 1. From 0.5 to 100 parts by mass of raw rubber.
A step of molding a rubber composition obtained by mixing and kneading 5 parts by mass of a silane coupling agent to obtain a molded article made of crosslinked rubber, and the surface of this molded article having the following general formula (I) A method for producing a rubber product, comprising: a step of adhering a fluorine-based compound shown therein; and a step of heat-treating the molded body having the fluorine-based compound adhered to the surface thereof. [Chemical 1] (In the formula, R _F is a group containing a fluoroalkyl group, R ¹
Is a functional group having reactivity with a hydrolyzable group, R ² is
A hydrogen atom or an alkyl group, R ³ and R ⁴ are the same or different and represent a hydrogen atom or a monovalent organic group. x is an integer of 1 to 100 and y is an integer of 0 to 500. ) 2. The rubber product according to claim 1, wherein the fluorine compound is applied to the surface of the molded body by applying a solution of the fluorine compound to the surface of the molded body. Manufacturing method. 3. The rubber product according to claim 1, wherein the fluorine-containing compound is attached to the surface of the molded body by immersing the molded body in a solution of the fluorine-based compound. Production method. 4. The above-mentioned general formula (I) representing the fluorine-based compound, wherein the functional group represented by R ¹ is an alkoxysilyl group or an alkoxyalkoxysilyl group. A method for manufacturing a rubber product according to any one of 1. 5. The functional group represented by R ¹ in the above general formula (I) representing the fluorine-based compound, is a trimethoxysilyl group.
A method for manufacturing a rubber product according to any one of 1. Wherein the general formula representing the fluorine compound (I), the group having a fluoroalkyl group represented by R _{F is, -CF 3, -C 2 F 5} , -C 3 F 7, −
_{C 6 F 13, -C 7 F} 15 or -CF (CF ₃₎ [OCF
₂ CF (CF ₃ )] _p OC ₃ F ₇ (wherein p is 0, 1 or 2).
A method for manufacturing the rubber product according to claim 5. 7. The method for producing a rubber product according to claim 1, wherein the fluorine-based compound is a compound represented by the following formula (1). [Chemical 2] (In the formula, x ′ is 2 or 3.) 8. The method for producing a rubber product according to claim 1, wherein the reactive organic functional group contained in the silane coupling agent is a mercapto group or a vinyl group.