JP2011032323A - Curable fluoropolyether-based rubber composition and rubber product comprising cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable fluoropolyether-based rubber composition which is easy to mold owing to low viscosity and gives a cured product excellent in solvent resistance, chemical resistance, weather resistance, mold releasability, water repellency, oil repellency and heat resistance and excellent further in electric conductivity, and a rubber product comprising a cured product of the composition. <P>SOLUTION: The curable fluoropolyether-based rubber composition comprises: (A) a straight chain fluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in a main chain; (B) an organosilicon compound having at least two hydrogen atoms bonded to a silicon atom in one molecule; (C) multilayer carbon nanotubes; and (D) a catalyst for a hydrosilylation reaction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a curable fluoropolymer that is easy to mold with low viscosity, has excellent solvent resistance, chemical resistance, weather resistance, releasability, water repellency, oil repellency and heat resistance, and further provides a cured product with excellent electrical conductivity. The present invention relates to a polyether rubber composition and a rubber product containing a cured product thereof.

Conventionally, a linear fluoropolyether compound having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain, and at least two hydrogen atoms bonded to a silicon atom in one molecule A composition comprising the above-described organosilicon compound and a hydrosilylation reaction catalyst is excellent in properties such as heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency, weather resistance, etc. and has a good balance of these properties. It is known to give an object (Patent Document 1: Japanese Patent No. 2990646).
However, in order to impart electrical conductivity to such a fluoropolyether-based rubber composition, it is necessary to add a large amount of conductive filler. While the fluidity | liquidity of the said composition fell, there existed a problem that the elongation of the rubber | gum after hardening of the said composition fell.

Japanese Patent No. 2990646

  The present invention has been made in view of the above circumstances, and is easy to mold with low viscosity, excellent in solvent resistance, chemical resistance, weather resistance, releasability, water repellency, oil repellency and heat resistance, and further electrically conductive. An object of the present invention is to provide a curable fluoropolyether-based rubber composition that gives a cured product that is excellent in resistance and a rubber product containing the cured product.

  As a result of studies to achieve the above object, the present inventor has found that, by adding carbon nanotubes to a curable fluoropolyether rubber composition, a cured product with particularly low viscosity and excellent electrical conductivity A curable fluoropolyether-based rubber composition that gives a high molecular weight is obtained, and the present inventors have found that rubber products containing the cured product are useful.

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基、Ｒ¹は水素原子、置換若しくは非置換の一価炭化水素基、Ｘ’は−ＣＨ₂−、−ＯＣＨ₂−、−ＣＨ₂ＯＣＨ₂−又は−ＣＯ−ＮＲ¹−Ｙ’−（Ｙ’は−ＣＨ₂−又は下記構造式（Ｚ’）

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基であり、Ｒ¹は上記と同じである。Ｒｆ¹は二価のパーフルオロポリエーテル基であり、ａは独立に０又は１である。］
で表される直鎖状フルオロポリエーテル化合物である請求項１記載の硬化性フルオロポリエーテル系ゴム組成物。
請求項３：
請求項１又は２記載の硬化性フルオロポリエーテル系ゴム組成物の硬化物を含むことを特徴とするゴム製品。 Accordingly, the present invention provides the following curable fluoropolyether rubber composition and a rubber product containing the cured product.
Claim 1:
(A) a linear fluoropolyether compound having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain;
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule;
(C) multi-walled carbon nanotube,
(D) A bicurable fluoropolyether rubber composition comprising a hydrosilylation reaction catalyst.
Claim 2:
The component (A) is represented by the following general formula (1)
_{CH 2 = CH- (X) a} -Rf 1 - (X ') a -CH = CH 2 (1)
[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 - or -Y-NR ¹ -CO- (Y is -CH ₂ - or the following structural formula (Z)

O, m or p-dimethylsilylphenylene group represented by formula (I), R ¹ is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group, X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ — or —CO—NR ¹ —Y′— (Y ′ is —CH ₂ — or the following structural formula (Z ′)

O, m or p-dimethylsilylphenylene group represented by formula (I), and R ¹ is the same as above. Rf ¹ is a divalent perfluoropolyether group, and a is independently 0 or 1. ]
The curable fluoropolyether rubber composition according to claim 1, which is a linear fluoropolyether compound represented by the formula:
Claim 3:
A rubber product comprising a cured product of the curable fluoropolyether rubber composition according to claim 1.

  According to the present invention, it is easy to mold with low viscosity, and has excellent solvent resistance, chemical resistance, weather resistance, releasability, water repellency, oil repellency and heat resistance, and further provides a cured product with excellent electrical conductivity. A rubber product comprising a functional fluoropolyether rubber composition and a cured product thereof can be provided.

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基、Ｒ¹は水素原子、置換若しくは非置換の一価炭化水素基、好ましくはメチル基、フェニル基又はアリル基、Ｘ’は−ＣＨ₂−、−ＯＣＨ₂−、−ＣＨ₂ＯＣＨ₂−又は−ＣＯ−ＮＲ¹−Ｙ’−（Ｙ’は−ＣＨ₂−又は下記構造式（Ｚ’）

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基であり、Ｒ¹は上記と同じである。Ｒｆ¹は二価のパーフルオロポリエーテル基であり、ａは独立に０又は１である。］ Hereinafter, the present invention will be described in more detail.
[(A) component]
The component (A) of the present invention is a linear fluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain.
Examples of such component (A) include polyfluorodialkenyl compounds represented by the following general formula (1).
_{CH 2 = CH- (X) a} -Rf 1 - (X ') a -CH = CH 2 (1)
[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 - or -Y-NR ¹ -CO- (Y is -CH ₂ - or the following structural formula (Z)

O, m or a p-dimethylsilylphenylene group represented by formula (I), R ¹ is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group, preferably a methyl group, a phenyl group or an allyl group, X ′ Is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ — or —CO—NR ¹ —Y′— (Y ′ is —CH ₂ — or the following structural formula (Z ′)

O, m or p-dimethylsilylphenylene group represented by formula (I), and R ¹ is the same as above. Rf ¹ is a divalent perfluoropolyether group, and a is independently 0 or 1. ]

（式中、ｐ及びｑは１〜１５０の整数であって、かつｐとｑの和は、２〜２００である。また、ｒは０〜６の整数、ｔは２又は３である。）

（式中、ｕは１〜２００の整数、ｖは１〜５０の整数、ｔは上記と同じである。） Here, Rf ^{1 in the} general formula (1) is a divalent perfluoropolyether structure, and compounds represented by the following general formulas (i) and (ii) are preferable.

(In the formula, p and q are integers of 1 to 150, and the sum of p and q is 2 to 200. Also, r is an integer of 0 to 6, and t is 2 or 3.)

(In the formula, u is an integer of 1 to 200, v is an integer of 1 to 50, and t is the same as above.)

［式中、Ｘは−ＣＨ₂−、−ＣＨ₂Ｏ−、−ＣＨ₂ＯＣＨ₂−又は−Ｙ−ＮＲ¹−ＣＯ−（Ｙは−ＣＨ₂−又は下記構造式（Ｚ）

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基、Ｒ¹は水素原子、メチル基、フェニル基又はアリル基、Ｘ’は−ＣＨ₂−、−ＯＣＨ₂−、−ＣＨ₂ＯＣＨ₂−又は−ＣＯ−ＮＲ¹−Ｙ’−（Ｙ’は−ＣＨ₂−又は下記構造式（Ｚ’）

で示されるｏ，ｍ又はｐ−ジメチルシリルフェニレン基）で表される基であり、Ｒ¹は上記と同じである。ａは独立に０又は１、Ｌは２〜６の整数、ｂ及びｃはそれぞれ０〜２００の整数である。］ (A) As a preferable example of a component, the compound represented by following General formula (2) is mentioned.

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 - or -Y-NR ¹ -CO- (Y is -CH ₂ - or the following structural formula (Z)

O, m or p-dimethylsilylphenylene group represented by formula (I), R ¹ is a hydrogen atom, methyl group, phenyl group or allyl group, X ′ is —CH ₂ —, —OCH ₂ —, —CH. ₂ OCH ₂ — or —CO—NR ¹ —Y′— (Y ′ is —CH ₂ — or the following structural formula (Z ′)

O, m or p-dimethylsilylphenylene group represented by formula (I), and R ¹ is the same as above. a is independently 0 or 1, L is an integer of 2 to 6, and b and c are integers of 0 to 200, respectively. ]

[Component (B)]
The component (B) of the present invention is an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule. The component (B) functions as a crosslinking agent or chain extender for the component (A). From the viewpoint of compatibility with the component (A), dispersibility, and uniformity after curing, Those having one or more fluorine-containing groups are preferred.

（式中、ｆは２〜２００、好ましくは２〜１００、ｈは１〜３の整数である。）

（式中、ｉ及びｊは１以上の整数、ｉ＋ｊの平均は２〜２００、好ましくは２〜１００である。） Examples of the fluorine-containing group include those represented by the following general formula.
C _g F _{2g + 1} −
(In the formula, g is an integer of 1 to 20, preferably 2 to 10.)
−C _g F _2g −
(In the formula, g is an integer of 1 to 20, preferably 2 to 10.)

(In the formula, f is 2 to 200, preferably 2 to 100, and h is an integer of 1 to 3.)

(In the formula, i and j are integers of 1 or more, and the average of i + j is 2 to 200, preferably 2 to 100.)

  Examples of the component (B) having such a fluorine-containing group include the following compounds. These compounds may be used alone or in combination of two or more. In the following formulae, Me represents a methyl group, and Ph represents a phenyl group.

The blending amount of the component (B) is such that the hydrosilyl group of the component (B), that is, the Si-H group is usually added to 1 mol of an alkenyl group such as a vinyl group, allyl group, cycloalkenyl group, etc. The amount is preferably 0.5 to 5 mol, more preferably 1 to 2 mol.
If the amount is less than 0.5 mol, the degree of crosslinking may be insufficient. If the amount exceeds 5 mol, the extension of the chain length is prioritized, resulting in insufficient curing, foaming, heat resistance, compression. Permanent distortion characteristics may deteriorate.

[Component (C)]
The component (C) of the present invention is a multi-walled carbon nanotube, and acts as an additive that imparts the conductivity and rubber strength of the cured rubber.
Carbon nanotubes include single-walled and multi-walled carbon nanotubes. Since they are added to rubber and blended, multi-walled carbon nanotubes that are difficult to cut even with the shear during blending are preferred.

In general, in order to impart conductivity to a rubber material, it is necessary to add a large amount of a conductive filler to the amount of the polymer component. Therefore, there is a problem that workability at the time of processing the liquid fluororubber with LIMS moldability or the like is extremely deteriorated.
Since carbon nanotubes can be imparted with a small amount of conductivity, they are hardly affected by thickening and can be molded by the same processing method as in the prior art.
(C) As for the addition amount of a component, 0.1-10.0 mass parts is preferable with respect to 100 mass parts of (A) component. If the amount is less than 0.1 parts by mass, the conductivity may not be ensured. If the amount exceeds 10.0 parts by mass, the viscosity of the composition increases and the workability during processing deteriorates. Rubber elongation may decrease, which is not preferable.

[(D) component]
(D) component of this invention is a hydrosilylation reaction catalyst, and is a catalyst which accelerates | stimulates the addition reaction of the alkenyl group in (A) component, and the hydrosilyl group in (B) component.
Since this hydrosilylation reaction catalyst is generally a noble metal compound and is expensive, platinum or platinum compounds that are relatively easily available are often used.

Examples of the platinum compound include chloroplatinic acid or a complex of chloroplatinic acid and an olefin such as ethylene, a complex of alcohol or vinyl siloxane, metal platinum carrying silica, alumina, carbon or the like. Rhodium, ruthenium, iridium and palladium compounds are also known as platinum group metal catalysts other than platinum compounds. For example, RhCl (PPh ₃ ) ₃ , RhCl (CO) (PPh ₃ ) ₂ , Ru ₃ (CO) ₁₂ , IrCl (CO) (PPh ₃ ) ₂ , Pd (PPh ₃ ) _{4 and the} like can be exemplified.

  The compounding amount of the hydrosilylation reaction catalyst can be a catalyst amount, but is usually 0.1 to 100 ppm (in terms of platinum) with respect to 100 parts by mass of the total amount of the components (A), (B) and (C). It is preferable to mix | blend in a ratio.

[Other ingredients]
In the composition of this invention, you may add various fillers, such as a reinforcing filler, in order to improve mechanical strength besides the said (A)-(D) component.
Reinforcing fillers improve mechanical strength, thermal stability, weather resistance, chemical resistance or flame resistance, reduce thermal shrinkage during curing, and lower the thermal expansion coefficient of elastic bodies obtained by curing. Or added for the purpose of reducing gas permeability, but the main purpose is to improve mechanical strength.

  Examples of the filler include fumed silica, wet silica, pulverized silica, calcium carbonate, diatomaceous earth, carbon black, various metal oxide powders, and the like, and those treated with various surface treatment agents. Good. Among these, fumed silica is particularly preferable from the viewpoint of improving mechanical strength, and further, fumed silica treated with a silane-based surface treatment agent is preferable from the viewpoint of improving dispersibility.

  As addition amount of a filler, 5-200 mass parts is preferable with respect to 100 mass parts of (A) component. In particular, 10 to 60 parts by mass is preferable from the viewpoint of stability of mechanical properties.

Furthermore, the curable fluoropolyether rubber composition of the present invention can be blended with appropriate pigments, dyes, and the like, if necessary.
Moreover, various compounding agents can be added as long as the object of the present invention is not impaired. Examples of such an optional component include 1-ethynyl-1-hydroxycyclohexane, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1- Acetylene alcohol such as penten-3-ol, phenylbutenol, 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne, or the like, or polymethylvinylsiloxane cyclic compound And a hydrosilylation reaction catalyst control agent such as an organic phosphorus compound, whereby the curing reactivity and storage stability can be kept moderate.

[Composition and method for producing cured product]
The manufacturing method in particular of the curable composition of this invention is not restrict | limited, It can manufacture by kneading the said component. The composition may be divided into two and mixed at the time of use.
The cured product is formed by injecting the composition of the present invention into a suitable mold and curing the composition, or by coating the composition on a suitable substrate and curing the composition. By the method. Moreover, hardening can be easily performed by the process for about 10 seconds-30 minutes normally at the temperature of 100-180 degreeC.

[Use of cured product]
The curable fluoropolyether rubber-based rubber composition of the present invention is cured with excellent heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency, weather resistance, and the like by curing. Since a product (rubber) can be formed, it can be used in various applications as a cured product alone or as a rubber product of a composite material of the cured product and another substrate by the above-described cured product production method. it can. For example, sealing materials for aircraft, automobiles, chemical plants, office equipment, consumer electronics, semiconductor production lines, analytical / physical equipment, medical equipment, aircraft, fuel cells, etc., coating materials, It can be suitably used for rubber products that require semiconductivity, such as roll materials, potting materials, O-rings, masking materials, and adhesive materials in the TSV process. Especially suitable for roll materials for copiers for office machines, belt materials, calculators for consumer electronics, conductive rubber such as key rubber for mobile phones, electrical moisture-proof coating materials, and sensor potting materials can do.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In addition, a part shows a mass part by the following example.

[Example]
Production of composition Ratio of 100 parts of polymer (viscosity 5,300 mm ² / s, average molecular weight 16,000, vinyl group content 0.012 mol / 100 g) represented by the following formula (3) treated with trimethylsiloxy group Add 23 parts of fumed silica with a surface area of 200 m ² / g, mix, and after 2 hours of heat treatment at 150 ° C., disperse on a three-roll mill, and add 1.0 part of Nikkiso 30-nanoclass carbon nanotubes. And the base was produced by performing a dispersion process on a three roll mill. To 100 parts of this base, 2.74 parts of a fluorine-containing organosilicon compound represented by the following formula (4), a toluene solution of a catalyst obtained by modifying chloroplatinic acid with a compound represented by the following formula (5) (platinum concentration: 0) 0.5 parts by mass) and 0.4 parts of fluorine-modified acetylene alcohol were added and mixed to prepare Composition I.

Composition Viscosity Evaluation The viscosity of Composition I was measured according to JIS K7117.
The rubber property evaluation composition I was degassed under reduced pressure, placed on a 2 mm thick 170 mm × 130 mm rectangular frame, evacuated again, press-cured at 100 kg / cm ² , 150 ° C./10 minutes, and then 200 ° C./4. Time postcured. The test piece was cut out from the cured sample, and physical properties such as hardness, elongation, tensile strength, tear strength, etc. were measured according to JIS K6251, 6252, 6253.
The composition I for volume resistivity evaluation was degassed under reduced pressure, placed in a 1.0 mm thick 130 mm × 130 mm square frame, evacuated again, and press-cured at 100 kg / cm ² , 150 ° C./10 minutes, and then 200 Post cure was performed at 4 ° C for 4 hours. The volume resistivity of the molded sheet was measured using a digital ultrahigh resistance / microammeter manufactured by ADC Co., Ltd.

[Comparative example]
A composition II was prepared in the same manner as in Example except that 1.0 part of electrochemically electrified black HS-100 was added instead of carbon nanotubes. Further, the composition viscosity, rubber physical properties and rubber volume resistivity were evaluated in the same manner as in the examples.

  Various evaluation results of Examples and Comparative Examples are shown in Table 1.

  As shown in Table 1, the viscosity of the composition is almost the same as that of the comparative example, while maintaining the conventional rubber properties such as hardness, elongation, tensile strength and tear strength (crescent) after curing. It can also be seen that a cured product having a sufficiently low volume resistivity is formed.

Claims (3)

(A) a linear fluoropolyether compound having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain;
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule;
(C) multi-walled carbon nanotube,
(D) A bicurable fluoropolyether rubber composition comprising a hydrosilylation reaction catalyst. The component (A) is represented by the following general formula (1)
_{CH 2 = CH- (X) a} -Rf 1 - (X ') a -CH = CH 2 (1)
[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 - or -Y-NR ¹ -CO- (Y is -CH ₂ - or the following structural formula (Z)

O, m or p-dimethylsilylphenylene group represented by formula (I), R ¹ is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group, X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ — or —CO—NR ¹ —Y′— (Y ′ is —CH ₂ — or the following structural formula (Z ′)

O, m or p-dimethylsilylphenylene group represented by formula (I), and R ¹ is the same as above. Rf ¹ is a divalent perfluoropolyether group, and a is independently 0 or 1. ]
The curable fluoropolyether rubber composition according to claim 1, which is a linear fluoropolyether compound represented by the formula:   A rubber product comprising a cured product of the curable fluoropolyether rubber composition according to claim 1.