JP2003183426A - Surface treatment method for curable fluoropolyether- based rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce surface tackiness by treating the surface of a cured product of a curable fluoropolyether-based rubber composition with a specific organohydrogenpolysiloxane. <P>SOLUTION: There is provided a surface-treatment method for a cured product of a curable fluoropolyether-based rubber composition, which comprises surface-treating a cured product of a curable fluoropolyether-based rubber composition with an organohydrogenpolysiloxane represented by the formula (1), (wherein R<SP>1</SP>is a group selected from a monovalent hydrocarbon group containing independently no aliphatic unsaturated bond and a hydrogen atom, R<SP>2</SP>is a monovalent hydrocarbon group containing independently no aliphatic unsaturated bond, Rf is a monovalent substituent having a monovalent perfluoroalkyl group and the like in the molecule, and a, b and c are each an integer satisfying a≥3, b≥1, c≥0, a+b+c≤50, and 0.3≤a/(a+b+c)<1.0). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to water repellency, oil repellency,
It has excellent chemical resistance, weather resistance, and mechanical properties, and reduces the surface tackiness of the cured product of the curable fluoropolyether rubber composition that is suitable for use in O-rings, diaphragms, valve materials, roll materials, etc. Surface treatment method.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
A curable fluoropolyether rubber composition is used for a seal member and a diaphragm that improve the sealability as a component of a valve mechanism. Usually rubber material is
It has the property of adhering to the parts that are in contact with it, causing various problems.

For this reason, in order to reduce the tackiness of conventional rubber materials, surface treatment with mica, molybdenum disulfide or the like is performed.

However, in the above treatment, the effect of reducing the tackiness of the base material with the rubber material is insufficient, and there is a problem that there is a possibility of contamination due to transfer to the adhesive member.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a surface treatment method for reducing the surface tackiness of a cured product of a curable fluoropolyether rubber composition.

[0006]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies to achieve the above object, the present inventor has found that an organohydrogenpolysiloxane represented by the following general formula (1) is used. By treating the surface of the cured product of the curable fluoropolyether rubber composition,
The inventors have found that surface tackiness can be reduced, and have completed the present invention.

[Chemical 4] (In the formula, R ¹ is a group selected from an unsubstituted or substituted monovalent hydrocarbon group not independently containing an aliphatic unsaturated bond and a hydrogen atom, and R ² is independently an aliphatic unsaturated bond. An unsubstituted or substituted monovalent hydrocarbon group which does not contain R
f is a monovalent substituent having a monovalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group or a divalent perfluorooxyalkylene group in the molecule. , A, b, and c
Is a ≧ 3, b ≧ 1, c ≧ 0 and a + b + c ≦ 50,
It is an integer satisfying 0.3 ≦ a / (a + b + c) <1.0. )

Therefore, the present invention provides a surface treatment method for a cured product of a curable fluoropolyether rubber composition, which is characterized in that the surface treatment is carried out with the organohydrogenpolysiloxane represented by the general formula (1). To do.

The present invention will be described in more detail below.
The organohydrogenpolysiloxane used in the surface treatment method of the present invention is an organohydrogenpolysiloxane represented by the following general formula (1), which is a feature of the present invention and is a cured product of a fluoropolyether rubber composition. It greatly contributes to the reduction of surface tackiness.

[Chemical 5] (In the formula, R ¹ is a group selected from an unsubstituted or substituted monovalent hydrocarbon group not independently containing an aliphatic unsaturated bond and a hydrogen atom, and R ² is independently an aliphatic unsaturated bond. An unsubstituted or substituted monovalent hydrocarbon group which does not contain R
f is a monovalent substituent having a monovalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group or a divalent perfluorooxyalkylene group in the molecule. , A, b, and c
Is a ≧ 3, b ≧ 1, c ≧ 0 and a + b + c ≦ 50,
It is an integer satisfying 0.3 ≦ a / (a + b + c) <1.0. )

Here, R ¹ is a group selected from an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond and a hydrogen atom independently, and as the monovalent hydrocarbon group,
An alkyl group such as a methyl group, an ethyl group or a propyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; an aryl group such as a phenyl group or a tolyl group; and one of hydrogen atoms bonded to carbon atoms of these groups Examples thereof include halogen atoms such as chlorine, bromine and iodine, or a group substituted with a cyano group, such as a chloromethyl group.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0010] R ² is an unsubstituted or substituted monovalent hydrocarbon group free of aliphatic unsaturated bonds independently, the R ¹
The monovalent hydrocarbon group exemplified in 1. can be mentioned. Of these, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group is particularly preferable.

Rf is a monovalent substituent having either a monovalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group or a divalent perfluorooxyalkylene group in the molecule. Base, 1
As the divalent perfluoroalkyl group, the monovalent perfluorooxyalkyl group, the divalent perfluoroalkylene group, and the divalent perfluorooxyalkylene group, those represented by the following general formula can be particularly mentioned. <Monovalent perfluoroalkyl _{group> C m F 2m + 1 -} (. However, m is 1 to 20, preferably an integer of 2 to 10) <divalent perfluoroalkylene group> -C _m F _2m -(However, m is an integer of 1 to 20, preferably 2 to 10.) <Monovalent perfluorooxyalkyl group>

[Chemical 6] (However, n is an integer of 1 to 5.) <Divalent perfluorooxyalkylene group>

[Chemical 7] (P and q are integers of 1 or more, and 2 ≦ p + q ≦ 200
And r is an integer of 2 ≦ r ≦ 6. )

[Chemical 8] (R is an integer 2 ≦ r ≦ 6, s is an integer s ≧ 0, and t is t ≧
It is an integer of 0, and s and t satisfy 0 ≦ s + t ≦ 200. )

[Chemical 9] (U is an integer of 1 ≦ u ≦ 200 and v is an integer of 1 ≦ v ≦ 50.) — (CF ₂ O) _e — (CF ₂ CF ₂ O) _g —CF ₂ — (however, e and g Are each an integer of 1 to 50.)

As the divalent linking group connecting these perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group or perfluorooxyalkylene group and a silicon atom, an alkylene group, an arylene group and their combination, or an ether bond oxygen atom in these groups, an amide bond may be those obtained by interposing a carbonyl bond or the like, for _{example, -CH 2 CH 2 - -CH 2} CH 2 CH 2 - -CH 2 CH 2 _{CH 2 OCH 2 - -CH 2 CH} 2 CH 2 -NH-CO- -CH 2 CH 2 CH 2 -N (Ph) -CO- ( where, Ph
Is a phenyl group. ) —CH ₂ CH ₂ CH ₂ —N (CH ₃ ) —CO— —CH ₂ CH ₂ CH ₂ —O—CO— and the like having 2 to 12 carbon atoms.

A is an integer of 3 or more. By setting a to 3 or more, the organohydrogenpolysiloxane as the surface treatment agent can increase the crosslink density on the surface of the cured product of the fluoropolyether rubber composition and exert the desired effect of preventing tackiness. . b is an integer of 1 or more. b
By setting the ratio to 1 or more, the wettability with the fluoropolyether rubber composition can be improved and uniform application can be achieved. Furthermore, c is an integer of 0 or more.

The degree of polymerization (a + b + c) must be 50 or less, and preferably 15 or less, in order to uniformly coat and permeate the rubber layer. Degree of polymerization is 50
If it is larger, it does not uniformly penetrate into the rubber layer, and a cured layer of organohydrogenpolysiloxane is formed on the surface,
Only the surface layer becomes extremely hard and brittle.

Further, in order for the organohydrogenpolysiloxane as the surface treating agent to sufficiently exert the desired effect of preventing tackiness, the aliphatic unsaturated group and the organohydrogen in the fluoropolyether type rubber composition are used. the reaction _{Si-H + H 2 O →} Si-OH + H 2 Si-OH + Si-OH → Si-O-Si + H 2 O in addition reaction and the following occurs between the silicon-bonded hydrogen atoms in the polysiloxane, a film on the surface It is necessary to make it moderately hard, and for that purpose, a / (a + b + c) needs to be 0.3 or more.

Here, as a method for applying the organohydrogenpolysiloxane, the surface of the cured product of the fluoropolyether rubber composition is diluted with the organohydrogenpolysiloxane or optionally the organohydrogenpolysiloxane with a fluorine solvent. Gauze the solution
Examples of the method include coating by surface coating with a brush or the like, coating by spray coating, dip coating, or the like. In order to promote the above reaction and obtain a desired surface film in a short time, a method of heat treatment under the conditions of 80 to 200 ° C. and 30 to 90 minutes is preferable.

Further, organohydrogenpolysiloxane is applied in order to sufficiently exert the effect of preventing surface tackiness and prevent cracking and peeling of the surface-treated layer when the cured product of the rubber composition is deformed due to elongation or the like. The thickness of the surface-treated surface-treated layer is preferably in the range of 0.1 to 20 μm. When the surface treatment layer is less than 0.1 μm,
There is a possibility that a sufficient anti-adhesion effect of the surface treatment agent may not be obtained, and if it exceeds 20 μm, the surface treatment layer becomes very hard and brittle, so when the cured product of the rubber composition is deformed due to elongation or the like, cracks and Peeling may occur.

Next, the curable fluoropolyether rubber composition comprises (A) a linear fluoropolyether compound having alkenyl groups at both ends of the molecular chain and a perfluoroalkyl ether structure in the main chain. 100 parts by weight (B) Silica-based filler having a specific surface area of 50 m ² / g or more 10 to 40 parts by weight (C) Organosilicon compound (A) component having at least two hydrogen atoms bonded to silicon atoms in the molecule An effective amount (D) of a hydrosilylation reaction catalyst for curing the compound is preferably a curable fluoropolyether rubber composition having a catalytic amount as an essential component.

The linear fluoropolyether compound as the component (A) has alkenyl groups at both ends of the molecular chain and a perfluoroalkyl ether structure in the main chain, and is used as a base polymer for the composition. It

The alkenyl group in this linear fluoropolyether compound preferably has 2 to 8 carbon atoms. Further, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group and the like having a CH ₂ ═CH-structure at the terminal, particularly vinyl group and allyl group are preferable. The alkenyl groups may be bonded directly to both ends of the backbone of the linear fluoropolyether compound, a divalent linking group, e.g., -CH ₂ -, - CH _{2
O -, - CH 2 OCH 2} - or -Y-NR ³ -CO-
[(Wherein Y is —CH ₂ — or the following structural formula (Z)

[Chemical 10] A group represented by), or —CH ₂ —, —O
_{CH 2 -, - CH 2 OCH} 2 - or -CO-NR ³ -Y'-
[(Y ′ is —CH ₂ — or the following structural formula (Z ′)

[Chemical 11] A group represented by), R ³ is a hydrogen atom,
It is a methyl group, a phenyl group or an allyl group. ] And the like.

Examples of the perfluoroalkyl ether structure in the linear fluoropolyether compound include those represented by the following general formula. -(Rf'-O) _w- (In the formula, Rf 'has 1 to 6 carbon atoms, preferably 1 carbon atom.
Is a linear or branched perfluoroalkylene group of 3 to 3, and w is an integer of 1 to 500, preferably 2 to 400, and more preferably 10 to 200. ) Wherein - (Rf'-O) -, examples of the repeating unit represented, for _{example, -CF 2 O- -CF 2 CF 2} O- -CF 2 CF 2 CF 2 O- -CF (CF 3) CF 2 O _{- -CF 2 CF 2 CF 2 CF} 2 O- -CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 O- -C (CF 3) 2 O- and the like. Among them preferred are, -CF ₂ O _{- -CF 2 CF 2 O- -CF 2} CF 2 CF 2 O- and -CF (CF ₃₎ CF ₂ is O-.

In the perfluoroalkyl ether structure, one of these repeating units represented by — (Rf′—O) — may be used alone or in combination of two or more.

As a preferable representative example of the linear fluoropolyether compound as the component (A), the following general formula (2) CH ₂ ═CH— (X) _d —Rf ¹ — (X ′) _d —CH═CH is represented. ₂ (2) wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2
- or -Y-NR ³ -CO- (Y is -CH ₂ - or the following structural formula (Z)

[Chemical 12] A group represented by the formula), X ′ is —CH ₂ —, —O
_{CH 2 -, - CH 2 OCH} 2 - or -CO-NR ³ -Y'-
(Y ′ is —CH ₂ — or the following structural formula (Z ′)

[Chemical 13] A group represented by), R ³ is a hydrogen atom,
It is a methyl group, a phenyl group or an allyl group. Rf ¹ is 2
Is a divalent perfluoropolyether group, and d is independently 0.
Or 1. ], And preferably has a molecular weight of 400 to
100,000, particularly preferably 1,000 to 50,0
00 linear fluoropolyether compound.

In the above general formula (2), Rf ¹ is 2
A valent perfluoropolyether group, particularly one represented by the following formula is preferable.

[Chemical 14] (P and q are integers of 1 or more, and 2 ≦ p + q ≦ 200
And r is an integer of 2 ≦ r ≦ 6. )

[Chemical 15] (R is an integer 2 ≦ r ≦ 6, s is an integer s ≧ 0, and t is t ≧
It is an integer of 0, and s and t satisfy 0 ≦ s + t ≦ 200. )

[Chemical 16] (U is an integer of 1 ≦ u ≦ 200 and v is an integer of 1 ≦ v ≦ 50.) — (CF ₂ O) _e — (CF ₂ CF ₂ O) _g —CF ₂ — (however, e and g Are each an integer of 1 to 50.)

Specific examples of the linear fluoropolyether compound represented by the above general formula (2) include those represented by the following formula.

[Chemical 17]

[Chemical 18] (In the formula, x and y are each an integer of 0 to 200, and x +
y is an integer of 50 or more. )

These linear fluoropolyether compounds may be used alone or in combination of two or more.

The component (B) is a silica type filler having a specific surface area of 50 m ² / g or more. This is used to reinforce the fluoropolyether composition, and the silica-based filler has a specific surface area of at least 50 m ² / g or more in order to improve mechanical properties. There is a need to. The silica-based filler may be either dry-process silica called fumed silica or wet-process silica called precipitable silica, and these have a hydroxyl group bonded to a silicon atom on the surface thereof as organochlorosilane. , A silazane compound, a cyclic silazane compound, or a surface of which is hydrophobized with dimethylpolysiloxane having a low degree of polymerization.

The compounding amount of this silica-based filler is (A)
10 to 40 parts by weight based on 100 parts by weight of the component,
More preferably, it is 15 to 30 parts by weight. If it is less than 10 parts by weight with respect to 100 parts by weight of the component (A), the strength may not be improved, and if it is more than 40 parts by weight, the viscosity may increase so much that the compounding may be difficult.

The component (C) is an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in the molecule. The component (C) acts as a crosslinking agent and a chain extender. The organosilicon compound as the component (C) is not particularly limited as long as it has at least two hydrogen atoms bonded to silicon atoms, that is, two or more hydrosilyl groups (SiH) in one molecule. Considering compatibility with components, dispersibility, and homogeneity after curing, one or more 1
A divalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group, a divalent perfluorooxyalkylene group, and two or more, preferably three or more hydrosilyl groups. Those having are preferred. Examples of the perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group and perfluorooxyalkylene group include those represented by the following general formula. <Monovalent perfluoroalkyl _{group> C m F 2m + 1 -} (. However, m is 1 to 20, preferably an integer of 2 to 10) <divalent perfluoroalkylene group> -C _m F _2m -(However, m is an integer of 1 to 20, preferably 2 to 10.) <Monovalent perfluorooxyalkyl group>

[Chemical 19] (However, n is an integer of 1 to 5.) <Divalent perfluorooxyalkylene group>

[Chemical 20] (P and q are integers of 1 or more, and 2 ≦ p + q ≦ 200
And r is an integer of 2 ≦ r ≦ 6. )

[Chemical 21] (R is an integer 2 ≦ r ≦ 6, s is an integer s ≧ 0, and t is t ≧
It is an integer of 0, and s and t satisfy 0 ≦ s + t ≦ 200. )

[Chemical formula 22] (U is an integer of 1 ≦ u ≦ 200 and v is an integer of 1 ≦ v ≦ 50.) — (CF ₂ O) _e — (CF ₂ CF ₂ O) _g —CF ₂ — (however, e and g Are each an integer of 1 to 50.)

As the divalent linking group connecting these perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group or perfluorooxyalkylene group and a silicon atom, an alkylene group, an arylene group and a combination thereof. Alternatively, these groups may have an ether bond oxygen atom, an amide bond, a carbonyl bond or the like interposed therebetween, and for example, —CH ₂ CH ₂ —CH ₂ CH ₂ CH ₂ —CH ₂ CH ₂ CH. _{2 OCH 2 - -CH 2 CH 2} CH 2 -NH-CO- -CH 2 CH 2 CH 2 -N (Ph) -CO- ( where, Ph
Is a phenyl group. ) —CH ₂ CH ₂ CH ₂ —N (CH ₃ ) —CO— —CH ₂ CH ₂ CH ₂ —O—CO— and the like having 2 to 12 carbon atoms.

Further, the organosilicon compound of the component (C) contains a monovalent or divalent fluorine-containing substituent, that is, a perfluoroalkyl group, a perfluorooxyalkyl group, a perfluoroalkylene group or a perfluorooxyalkylene group. Examples of the monovalent substituent bonded to a silicon atom other than the monovalent organic group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, an octyl group, and a decyl group. An alkenyl group such as a vinyl group or an allyl group; an aryl group such as a phenyl group, a tolyl group or a naphthyl group; an aralkyl group such as a benzyl group or a phenylethyl group; and at least a part of hydrogen atoms of these groups is a chlorine atom, 1 to 2 carbon atoms substituted with cyano group, such as chloromethyl group, chloropropyl group, cyanoethyl group, etc. Unsubstituted or substituted hydrocarbon group and the like.

As the organosilicon compound as the component (C),
It may be in the form of a ring, a chain, a three-dimensional network or a combination thereof. The number of silicon atoms in this organosilicon compound is
Although not particularly limited, it is usually 2 to 60, preferably 3 to 30.

The component (C) may be blended in an amount effective to cure the component (A), such as an alkenyl group 1 such as a vinyl group, an allyl group or a cycloalkenyl group contained in the component (A). With respect to moles, the hydrosilyl group of the component (C),
That is, the amount of SiH group is preferably 0.5 to 5 mol, more preferably 1 to 2 mol. If it is less than 0.5 mol, the degree of crosslinking will be insufficient, and if it exceeds 5 mol, chain extension will take precedence, resulting in insufficient curing, foaming, and deterioration of heat resistance, compression set characteristics and the like. There is a risk. The blending amount of the component (C) with respect to the component (A) is usually 0.1 to 5 with respect to 100 parts by weight of the component (A).
It can be in the range of 0 parts by weight.

Examples of the hydrosilylation reaction catalyst as the component (D) include transition metals, for example, platinum group metals such as Pt, Rh and Pd, and compounds of these transition metals. Since these compounds are generally noble metal compounds and are expensive, platinum group compounds that are relatively easily available are used.

Examples of the platinum compound include chloroplatinic acid;
Examples include, but are not limited to, complexes of chloroplatinic acid with olefins such as ethylene; complexes of chloroplatinic acid with alcohols or vinyl siloxanes; platinum supported on carriers such as silica, alumina, and carbon. Not something. Examples of platinum group metal compounds other than platinum compounds include rhodium, ruthenium, iridium and palladium compounds such as RhCl (PPh ₃ ) ₃ RhCl (CO) (PPh ₃ ) ₂ RhCl (C ₂ H ₄ ) ₂ Ru ₃ ( CO) ₁₂ IrCl (CO) (PPh ₃ ) ₂ Pd (PPh ₃ ) ₄ (wherein Ph represents a phenyl group) and the like.

The amount of these catalysts to be used is not particularly limited, and a desired curing rate can be obtained with a so-called catalyst amount, but it may be supported on a simple substance such as silica or alumina or diluted with a solvent. However, since the amount of the catalyst also changes depending on the form of the catalyst and the dilution ratio, in order to obtain a cured product from an economical point of view or in a favorable manner, the amount of the platinum group metal is 0.1 in terms of the total amount of the curable composition. It is preferably in the range of about 1,000 ppm (weight), particularly about 0.1 to 500 ppm (weight).

The composition of the present invention includes the above (A) to
In addition to the component (D), various conventionally known additives may be added as optional components within a range that does not impair the effects of the present invention. Examples of such components include 1-ethyl-1-hydroxycyclohexane, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyne-
3-ol, 3-methyl-1-penten-3-ol,
Acetylene alcohol such as phenylbutynol or 3-
Methyl-3-penten-1-yne, 3,5-dimethyl-
Control agent for hydrosilylation reaction catalyst such as 3-hexene-1-yne; Compound represented by the following formula

[Chemical formula 23] Adhesion-imparting agents such as organosiloxanes having an alkoxy group, an epoxy group and a SiH group in the molecule such as; pigments (for example, iron oxide, cerium oxide, carbon black, etc.), coloring agents such as dyes, antioxidants, etc. Can be mentioned.

Regarding the constitution of the curable fluoropolyether-based rubber composition, all the essential components of the above-mentioned components (A) to (D) are treated as one composition depending on the application, so-called one-liquid type. Or, for example, a part of the component (A), a part of the component (B) and the component (C) are used as one composition, and the balance of the component (A), the balance of the component (B) and ( It may be configured as a so-called two-component type in which the component D) is the other composition, and these are mixed at the time of use.

The curable fluoropolyether rubber composition can be easily cured by leaving it at room temperature or by heating it, but usually at room temperature (for example, 10 to 30).
C.) to 200.degree. C., preferably for 5 minutes to 24 hours.

[0040]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the examples below, parts indicate parts by weight.

Example 1 To 100 parts of a polymer represented by the following formula (3) (viscosity 4.4 Pa · s, average molecular weight 16500, vinyl group content 0.012 mol / 100 g), a silica-based filler was added dimethyldi. The treated silica treated with chlorosilane (specific surface area 186 m ² / g) was blended in a planetary mixer at a blending ratio of 25 parts, and then kneaded for 1 hour. After kneading, mix heat treatment at 170 ℃ for 2 hours,
Dispersion processing was performed with three rolls to manufacture a base.

[Chemical formula 24] (However, Rf ² represents the following formula, and Me is a methyl group.)

[Chemical 25]

The vinyl group content of the silica is determined by adding KOH to the treated silica filler and then heat treating at 300 ° C.
It was measured by quantifying the ethylene gas generated at that time with a gas chromatography device.

Further, to 125 parts of this base, 0.2 part of a toluene solution of a catalyst obtained by modifying chloroplatinic acid with a compound represented by the following formula (4) (platinum concentration: 0.5% by weight),
A curable fluoropolyether rubber composition was prepared by adding 0.4 parts of a 50% toluene solution of ethynylcyclohexanol and 3.35 parts of an SiH group-containing organosilicon compound represented by the following formula (5) and mixing them uniformly. I got a thing.

[Chemical formula 26]

From the obtained composition, a cured sheet having a thickness of 0.5 mm was molded under the conditions of press cure at 150 ° C. for 5 minutes and oven cure at 200 ° C. for 4 hours.

An organohydrogenpolysiloxane represented by the following formula (6) was applied to the surface of the obtained cured product of the sheet using a paper gauze, air-dried for 30 minutes, and then 20
Heat treatment was performed under the condition of 0 ° C./1 hour, and evaluation sample 1
Was produced.

[Chemical 27]

(Preparation of Peel Test Sample) The above evaluation sample and a 25 mm wide SUS plate were used in a uniaxial press,
A peeling test sample was obtained by press-bonding at room temperature under a pressure of 1 (kg / 1 cm ³ ).

(Measurement of Adhesiveness) The prepared peel test sample was subjected to 180 at room temperature at a speed of 50 (mm / min) using a tensile tester (autograph: manufactured by Shimadzu Corporation).
Degree peeling test was performed, and the peeling load was measured.

(Measurement of Thickness of Surface Treatment Layer) The thickness of the cured product before and after the surface treatment was measured with a dial cage, and the difference was determined by the following formula to obtain the thickness of the surface treatment layer. Thickness of surface treatment layer = thickness after surface treatment−thickness before surface treatment

Table 1 shows the results of the surface condition after coating the organohydrogenpolysiloxane, the evaluation of tackiness and the thickness of the surface treatment layer.

Example 2 An organohydrogenpolysiloxane represented by the following formula (7) was applied to the surface of the cured sheet prepared in Example 1 using a paper gauze, and 3
After air-drying for 0 minutes, heat treatment was performed under the condition of 200 ° C./1 hour to prepare a sample 2 for evaluation. The surface condition, the adhesiveness evaluation and the surface treatment layer thickness evaluation were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Chemical 28]

[Comparative Example 1] Adhesion was evaluated without surface treatment of the cured sheet of Example 1.
The evaluation results are shown in Table 1.

[Comparative Example 2] An organohydrogenpolysiloxane represented by the following formula (8) was applied to the surface of the cured sheet prepared in Example 1 using a paper gauze, and 3
After air-drying for 0 minutes, heat treatment was performed under the condition of 200 ° C./1 hour to prepare a sample 2 for evaluation. The surface condition, the adhesiveness evaluation and the surface treatment layer thickness evaluation were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Chemical 29]

[0053]

[Table 1]

[0054]

The surface tackiness can be lowered by treating the surface of the cured product of the curable fluoropolyether rubber composition with the organohydrogenpolysiloxane of the present invention.

Claims (4)

[Claims] 1. A curable fluoropolyether rubber composition characterized in that a cured product of a curable fluoropolyether rubber composition is surface-treated with an organohydrogenpolysiloxane represented by the following general formula (1). Surface treatment method for cured products. [Chemical 1] (In the formula, R ¹ is a group selected from an unsubstituted or substituted monovalent hydrocarbon group not independently containing an aliphatic unsaturated bond and a hydrogen atom, and R ² is independently an aliphatic unsaturated bond. An unsubstituted or substituted monovalent hydrocarbon group which does not contain R
f is a monovalent substituent having a monovalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group or a divalent perfluorooxyalkylene group in the molecule. , A, b, and c
Is a ≧ 3, b ≧ 1, c ≧ 0 and a + b + c ≦ 50,
It is an integer satisfying 0.3 ≦ a / (a + b + c) <1.0. ) 2. The thickness of the surface-treated layer surface-treated with organohydrogenpolysiloxane is 0.1.
2. The thickness is not less than μm and not more than 20 μm.
A surface treatment method for a cured product of the curable fluoropolyether rubber composition described. 3. A straight-chain fluoropolyether compound having a (A) alkenyl group at both ends of a molecular chain and a perfluoroalkyl ether structure in the main chain of the curable fluoropolyether rubber composition. Parts by weight (B) silica-based filler having a specific surface area of 50 m ² / g or more 10 to 40 parts by weight (C) an organosilicon compound (A) component having at least two hydrogen atoms bonded to silicon atoms in the molecule 3. An effective amount (D) of hydrosilylation reaction catalyst to be cured. The surface treatment method for a cured product of a curable fluoropolyether rubber composition according to claim 1 or 2, which comprises a catalytic amount as an essential component. 4. The surface of the cured product of the curable fluoropolyether rubber composition according to claim 3, wherein the linear fluoropolyether compound as the component (A) is a compound represented by the following general formula (2). Processing method. _{CH 2 = CH- (X) d} -Rf 1 - (X ') d -CH = CH 2 (2) [ wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2
- or -Y-NR ³ -CO- (Y is -CH ₂ - or the following structural formula (Z) ## STR2 ## A group represented by the formula), X ′ is —CH ₂ —, —O
_{CH 2 -, - CH 2 OCH} 2 - or -CO-NR ³ -Y'-
(Y ′ is —CH ₂ — or the following structural formula (Z ′): A group represented by), R ³ is a hydrogen atom,
It is a methyl group, a phenyl group or an allyl group. Rf ¹ is 2
Is a divalent perfluoropolyether group, and d is independently 0.
Or 1. ]