JP7087686B2 - Photocurable fluoropolyether-based rubber composition and its cured product - Google Patents

Description

The present invention relates to a photocurable fluoropolyether-based rubber composition that is cured by irradiation with light, particularly ultraviolet rays, and a cured product thereof, and the obtained fluoropolyether-based rubber cured product is particularly excellent in compression-resistant permanent strain resistance. ..

Conventionally, heat-curable fluoropolyether-based rubber compositions have well-balanced properties such as heat resistance, low temperature resistance, chemical resistance, solvent resistance, and oil resistance, and have excellent properties, so that they are mainly used in the automobile industry. It is applied in a wide range of fields (Patent Documents 1, 2 and 3). However, since the above-mentioned heat-curing type composition requires heating to obtain a cured product, a relatively large space for installing a heating furnace is required, and large parts that do not enter the heating furnace are required. It has problems such as difficulty in application to non-heatable parts and a decrease in productivity due to the batch type molding process.

On the other hand, a room temperature curing type fluoropolyether rubber composition has been found, and as such a composition, a condensation curing type and an amide crosslinked type have been invented so far. These compositions do not require heat treatment to obtain a cured product, and the obtained cured product is excellent in heat resistance, low temperature resistance, chemical resistance, solvent resistance, oil resistance, etc., and therefore, in various fields. Applications are expected (Patent Documents 4, 5, 6, 7 and 8). However, the room temperature curing type rubber composition has problems in terms of both storage stability and quick curing, such as thickening over time during storage and taking 24 hours or more to complete curing.

Further, when the room temperature curing type fluoropolyether rubber composition is molded into an О-ring or the like and used as a gasket material, there is also a problem that sufficient performance cannot be obtained in terms of compression resistance permanent strain resistance.

Japanese Unexamined Patent Publication No. 2001-192546 Japanese Patent No. 3646775 Japanese Patent No. 4016239 Japanese Patent No. 3232221 Japanese Patent No. 3183624 Japanese Patent No. 3350347 Japanese Patent No. 3617568 Japanese Patent No. 5146690

Therefore, the present invention provides a rubber-like cured product having excellent heat resistance, low temperature resistance, chemical resistance, solvent resistance, oil resistance, etc., and also provides storage stability of the composition and good curing characteristics at room temperature. It is an object of the present invention to provide a photocurable fluoropolyether-based rubber composition and a cured product thereof, which have and gives a cured product having excellent compression-resistant permanent strain characteristics.

As a result of diligent research to solve the above problems, the present inventors have (A) a linear chain having two or more alkenyl groups in one molecule and a perfluoropolyether structure in the main chain. A polyfluoro compound, (B) a fluorine-containing organohydrogen siloxane having two or more hydrogen atoms directly connected to a silicon atom in one molecule, (C) a photoactive hydrosilylation reaction metal catalyst, and (D) a BET specific surface area of 50 m. It has been found that a photocurable fluoropolyether-based rubber composition containing ² / g or more and silica fine powder whose surface has been hydrophobized with an alkyl group-containing silicon compound and a vinyl group-containing silicon compound can achieve the above object. , The present invention has been completed. That is, the present invention provides the following photocurable fluoropolyether-based rubber composition and a cured product thereof.

［式（１）中、Ｘは－ＣＨ₂－、－ＣＨ₂Ｏ－、－ＣＨ₂ＯＣＨ₂－又は－Ｙ－ＮＲ¹－ＣＯ－
（ここで、Ｙは－ＣＨ₂－、－Ｓｉ（ＣＨ₃）₂ＣＨ₂ＣＨ₂ＣＨ₂－、－Ｓｉ（ＣＨ₃）（ＣＨ＝ＣＨ₂）ＣＨ₂ＣＨ₂ＣＨ₂－、－Ｓｉ（ＣＨ＝ＣＨ₂）₂ＣＨ₂ＣＨ₂ＣＨ₂－又は下記構造式（Ｚ）

（式（Ｚ）中、Ｒ³、Ｒ⁴はそれぞれ独立に－ＣＨ₃又は－ＣＨ＝ＣＨ₂である。）
で示されるｏ－、ｍ－又はｐ－シリルフェニレン基であり、Ｒ¹は水素原子又は非置換若しくは置換の１価炭化水素基である）であり、
Ｘ’は－ＣＨ₂－、－ＯＣＨ₂－、－ＣＨ₂ＯＣＨ₂－又は－ＣＯ－ＮＲ²－Ｙ’－
（ここで、Ｙ’は－ＣＨ₂－、－ＣＨ₂ＣＨ₂ＣＨ₂Ｓｉ（ＣＨ₃）₂－、－ＣＨ₂ＣＨ₂ＣＨ₂Ｓｉ（ＣＨ₃）（ＣＨ＝ＣＨ₂）－、－ＣＨ₂ＣＨ₂ＣＨ₂Ｓｉ（ＣＨ＝ＣＨ₂）₂－又は下記構造式（Ｚ’）

（式（Ｚ’）中、Ｒ^3'、Ｒ^4'はそれぞれ独立に－ＣＨ₃又は－ＣＨ＝ＣＨ₂である。）
で示されるｏ－、ｍ－又はｐ－シリルフェニレン基であり、Ｒ²は水素原子又は非置換若しくは置換の１価炭化水素基である）であり、ｇは独立に０又は１であり、
Ｒｆ¹は下記式（ｉ）又は（ｉｉ）である。

（式（ｉ）中、ｐ及びｑはそれぞれ０又は１～１５０の整数であって、且つｐとｑの和の平均は２～２００である。ｒは０～６の整数、ｔは２又は３である。）

（式（ｉｉ）中、ｕは１～２００の整数、ｖは１～５０の整数、ｔは２又は３である。）
で表される２価のパーフルオロポリエーテル基である。］
［６］
（Ｂ）成分の含フッ素オルガノ水素シロキサンが、１分子中に１個以上の１価のパーフルオロアルキル基、１価のパーフルオロオキシアルキル基、２価のパーフルオロアルキレン基、及び／又は２価のパーフルオロオキシアルキレン基を有するものである［１］～［５］のいずれか１項に記載の光硬化性フルオロポリエーテル系ゴム組成物。
［７］
（Ｃ）成分の光活性型ヒドロシリル化反応金属触媒が、（η⁵－シクロペンタジエニル）トリ（σ－アルキル）白金（ＩＶ）錯体である［１］～［６］のいずれか１項に記載の光硬化性フルオロポリエーテル系ゴム組成物。
［８］
（Ｅ）成分として、ヒドロシリル化反応の反応制御剤を含む［１］～［７］のいずれか１項に記載の光硬化性フルオロポリエーテル系ゴム組成物。
［９］
［１］～［８］のいずれか１項に記載の光硬化性フルオロポリエーテル系ゴム組成物の硬化物。 [1]
(A) A linear polyfluoro compound having two or more alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain: 100 parts by mass,
(B) Fluoro-containing organohydrogen siloxane having two or more hydrogen atoms directly connected to silicon atoms in one molecule: 0.5 to 3.0 mol as Si—H group with respect to 1 mol of alkenyl group of component (A) Amount,
(C) Photoactive hydrosilylation reaction metal catalyst: 0.1 to 500 ppm in terms of mass of metal atom with respect to the component (A), and
(D) Silica fine powder having a BET specific surface area of 0.1 m ² / g or more and having a surface hydrophobic treatment of an alkyl group-containing reactive silicon compound and an alkenyl group-containing reactive silicon compound: (A) component 100 A photocurable fluoropolyether-based rubber composition containing 1 to 40 parts by mass with respect to parts by mass.
[2]
The photocurable fluoropolyether-based rubber composition according to [1], wherein the silica fine powder of the component (D) is surface-treated with a silazane compound having an alkyl group and a silazane compound having an alkenyl group.
[3]
The photocurable fluoropolyether-based rubber composition according to [1] or [2], wherein the silica fine powder of the component (D) is a dry silica fine powder.
[4]
In the silica fine powder of the component (D), the surface treatment agent for the silica fine powder is 0.1 to 40 mol% of the alkenyl group-containing reactive silicon compound and 60 to 99.9 mol% of the alkyl group-containing reactive silicon compound. The item according to any one of [1] to [3], which is treated with a ratio of ratio (however, 100 mol% in total of the alkyl group-containing reactive silicon compound and the alkenyl group-containing reactive silicon compound). Photocurable fluoropolyether-based rubber composition.
[5]
The photocurable fluoropolyether-based rubber composition according to any one of [1] to [4], wherein the component (A) is a linear polyfluoro compound represented by the following formula (1).

[In formula (1), X is -CH _2- , -CH ₂ O-, -CH ₂ OCH _2- or -Y-NR ¹ -CO-
(Here, Y is -CH _2- , -Si (CH ₃ ) ₂ CH ₂ CH ₂ CH _2- , -Si (CH ₃ ) (CH = CH ₂ ) CH ₂ CH ₂ CH _2- , -Si (CH) = CH ₂ ) ₂ CH ₂ CH ₂ CH ₂ -or the following structural formula (Z)

(In equation (Z), R ³ and R ⁴ are independently -CH ₃ or -CH = CH ₂ , respectively.)
It is an o-, m- or p-silylphenylene group represented by, and R ¹ is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group).
X'is -CH _2- , -OCH _2- , -CH ₂ OCH _2- or -CO-NR ² -Y'-
(Here, Y'is -CH _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) (CH = CH ₂ )-, -CH ₂ CH ₂ CH ₂ Si (CH = CH ₂ ) ₂ -or the following structural formula (Z')

(In equation (Z ^' ), R ^3'and R 4'are independently -CH ₃ or -CH = CH _2. )
It is an o-, m- or p-silylphenylene group represented by, R ² is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group), and g is independently 0 or 1.
Rf ¹ is the following formula (i) or (ii).

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

(In equation (ii), u is an integer of 1 to 200, v is an integer of 1 to 50, and t is 2 or 3.)
It is a divalent perfluoropolyether group represented by. ]
[6]
The fluorine-containing organohydrogensiloxane (B) component is one or more monovalent perfluoroalkyl groups, monovalent perfluorooxyalkyl groups, divalent perfluoroalkylene groups, and / or divalents in one molecule. The photocurable fluoropolyether-based rubber composition according to any one of [1] to [5], which has the perfluorooxyalkylene group of the above.
[7]
In any one of [1] to [6], the photoactive hydrosilylation reaction metal catalyst of the component (C) is a (η ⁵ -cyclopentadienyl) tri (σ-alkyl) platinum (IV) complex. The photocurable fluoropolyether-based rubber composition according to the above.
[8]
The photocurable fluoropolyether-based rubber composition according to any one of [1] to [7], which comprises a reaction control agent for a hydrosilylation reaction as a component (E).
[9]
The cured product of the photocurable fluoropolyether-based rubber composition according to any one of [1] to [8].

According to the present invention, it is possible to provide a photocurable fluoropolyether-based rubber composition having excellent heat resistance, low temperature resistance, chemical resistance, solvent resistance, oil resistance and the like. Further, it is possible to provide a photocurable fluoropolyether-based rubber composition and a cured product, which exhibit storage stability and good curing characteristics, and the obtained cured rubber product exhibits good compression-resistant permanent strain resistance.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[(A) component]
The component (A) in the photocurable fluoropolyether-based rubber composition of the present invention is a linear polyfluoro compound having two or more alkenyl groups in one molecule. Here, the number of alkenyl groups is preferably 2 to 30 in one molecule, more preferably 2 to 10, and particularly preferably 2 to 6. The composition of the present invention does not contain a linear polyfluoro compound having one alkenyl group in one molecule and having a perfluoropolyether structure in the main chain.
In the component (A) of the present invention, "linearity" means that the repeating units made of perfluorooxyalkylene constituting the perfluoropolyether structure of the main chain are linearly bonded to each other. The individual repeating units themselves are branched perfluorooxyalkylene units (eg, [-CF ₂ CF (CF ₃ ) O-] units, [-CF (CF ₃ ) O-] units, etc.). May be contained.

As the component (A), a linear polyfluoro compound having a branched structure in the perfluorooxyalkylene repeating unit in the main chain represented by the following formula (1) is particularly preferable.

[In formula (1), X is -CH _2- , -CH ₂ O-, -CH ₂ OCH _2- or -Y-NR ¹ -CO-
(Here, Y is -CH _2- , -Si (CH ₃ ) ₂ CH ₂ CH ₂ CH _2- , -Si (CH ₃ ) (CH = CH ₂ ) CH ₂ CH ₂ CH _2- , -Si (CH) = CH ₂ ) ₂ CH ₂ CH ₂ CH ₂ -or the following structural formula (Z)

(In equation (Z), R ³ and R ⁴ are independently -CH ₃ or -CH = CH ₂ , respectively.)
It is an o-, m- or p-silylphenylene group represented by, and R ¹ is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group).

X'is -CH _2- , -OCH _2- , -CH ₂ OCH _2- or -CO-NR ² -Y'-
(Here, Y'is -CH _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) (CH = CH ₂ )-, -CH ₂ CH ₂ CH ₂ Si (CH = CH ₂ ) ₂ -or the following structural formula (Z')

(In equation (Z ^' ), R ^3'and R 4'are independently -CH ₃ or -CH = CH _2. )
It is an o-, m- or p-silylphenylene group represented by, and R ² is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group).

g is independently 0 or 1.
Rf ¹ is the following formula (i) or (ii)

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

(In equation (ii), u is an integer of 1 to 200, v is an integer of 1 to 50, and t is 2 or 3.)
It is a divalent perfluoropolyether group represented by. ]

Here, as R ¹ and R ² , a hydrogen atom and a hydrocarbon group having 1 to 12 carbon atoms, particularly 1 to 10 are preferable, and as the hydrocarbon group, specifically, a methyl group, an ethyl group and a propyl group are used. , Alkyl groups such as butyl group, hexyl group, cyclohexyl group, octyl group; aryl groups such as phenyl group and trill group; aralkyl groups such as benzyl group and phenylethyl group, and a part of hydrogen atom of these groups or Examples thereof include a substituted monovalent hydrocarbon group in which the whole is substituted with a halogen atom such as fluorine.

Here, Rf ¹ in the formula (1) is a divalent perfluoropolyether group, and a group represented by the following formula (i) or (ii) is preferable.

(In formula (i), p and q are 0 or an integer of 1 to 150, preferably an integer of 10 to 150, respectively, and the average sum of p and q is 2 to 200, preferably 20 to 160. In addition, r is an integer of 0 to 6, preferably an integer of 0 to 4, and t is 2 or 3).

(In formula (ii), u is an integer of 1 to 200, preferably an integer of 20 to 160, v is an integer of 1 to 50, preferably an integer of 5 to 40, and t is 2 or 3. .)

Preferred examples of ^one Rf group include, for example, the following three ((i-1), (i-2) and (ii-1)). Of these, a divalent group having the structure of the first equation is particularly preferable.

(In equation (i-1), p1 and q1 are integers of 1 to 150, respectively, and p1 + q1 (average) = 2 to 200. L is an integer of 2 to 6.)

(In equation (i-2), p2 and q2 are integers of 1 to 150, respectively, and p2 + q2 (average) = 2 to 200. L is an integer of 2 to 6.)

(In equation (ii-1), u1 is an integer of 1 to 200, and v1 is an integer of 1 to 50.)

Preferred examples of the component (A) include a compound represented by the following formula (2).

[In formula (2), X ¹ is -CH _2- , -CH ₂ O-, -CH ₂ OCH _2- or -Y-NR ¹¹ -CO- (Y indicates the same as above, R ¹¹ is hydrogen. A group represented by an atom, a methyl group, a phenyl group or an allyl group), where X ^1'is -CH _2- , -OCH _2- , -CH ₂ OCH _2- or -CO-NR ¹² -Y'. -(R ¹² indicates the same as R ¹¹ above, Y'indicates the same as above), g is independently 0 or 1, L is an integer of 2 to 6, p3 and q3 is an integer of 1 to 150, and p3 + q3 (average) = 2 to 200, respectively. ]

Specific examples of the linear polyfluoro compound represented by the formula (1) include those represented by the following formula.

(In the formula, p'and q'are integers of 1 to 150, respectively, and p'+ q'(average) = 6 to 200.)

(In the formula, p'and q'are integers of 1 to 150, respectively, and p'+ q'(average) = 6 to 200.)

(In the formula, p "and q" indicate integers of 1 to 150, respectively, and numbers satisfying p "+ q" = 2 to 200.)

The amount of the alkenyl group contained in the linear polyfluoro compound represented by the formula (1) is preferably 0.00005 to 0.00050 mol / g, more preferably 0.00007 to 0.00040 mol / g. Is. If the amount of alkenyl groups contained in the linear polyfluoro compound is too small, the physical strength of the cured product may decrease or the cured product may not be obtained. Further, if the amount of alkenyl groups is too large, the obtained cured product may be brittle and easily cracked.

The viscosity (23 ° C.) of the linear polyfluoro compound of the formula (1) is preferably 100 to 100,000 mPa · s, more preferably 500 to 50,000 mPa · s, still more preferably 1,000 to 20. It is within the range of 000 mPa · s. It is desirable to use a linear polyfluoro compound having a viscosity within this range for a photocurable composition, and to use the composition for sealing, potting, coating, impregnation, etc., because the cured product has appropriate physical properties. As the linear polyfluoro compound of the formula (1), the one having the most appropriate viscosity is selected according to the application. At this time, it is also possible to mix a low-viscosity polymer and a high-viscosity polymer and adjust the viscosity to a desired level before use. In the present invention, the viscosity can be measured by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.), and in particular, the above general formula (1) or (2). The viscosity (23 ° C.) of the linear polyfluoro compound represented by (1) can be determined by the viscosity measurement specified in JIS K7117-1.
Further, the degree of polymerization (or molecular weight) of the linear polyfluoro compound reflected by the number of repetitions of the perfluorooxyalkylene unit constituting the perfluoropolyether structure of the main chain is determined by, for example, using a fluorosolvent as a developing solvent. It can be determined as a polystyrene-equivalent number average degree of polymerization (or number average molecular weight) or the like in gel permeation chromatography (GPC) analysis.

Further, in the present invention, in order to adjust the linear polyfluoro compound of the formula (1) to a desired number average molecular weight according to the purpose, the linear polyfluoro compound is previously provided with a hydrosilyl group (Si—H) in the molecule. It is also possible to hydrosilylate the organosilicon compound containing two groups) by a usual method and conditions, and use the product having an extended chain length as the component (A).

These linear polyfluoro compounds may be used alone or in combination of two or more.
In the composition of the present invention, the component (A) is preferably contained in an amount of 50 to 98% by mass, more preferably 60 to 95% by mass, and even more preferably 70 to 90% by mass.

[(B) component]
The component (B) has 1 or more, preferably 1 to 10 fluorine-containing organic groups in one molecule, and 2 hydrogen atoms (that is, a hydrosilyl group represented by Si—H) directly connected to a silicon atom. It is a fluorine-containing organohydrogen siloxane having 3 or more, preferably 3 to 50. The component (B) functions as a cross-linking agent and / or a chain length extender for the component (A). Further, the component (B) is a fluorine-containing organic group having one or more monovalent perfluoroalkyl groups in one molecule from the viewpoint of compatibility with the component (A), dispersibility, uniformity after curing and the like. Those having a fluorine-containing group such as a monovalent perfluorooxyalkyl group, a divalent perfluoroalkylene group, and / or a divalent perfluorooxyalkylene group are preferable.

Examples of the monovalent or divalent fluorine-containing organic group include those represented by the following formulas.

(In the formula, g is an integer of 1 to 20, preferably an integer of 2 to 10.)

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

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

(In the formula, d and e are integers of 1 to 50, preferably integers of 1 to 40, respectively.)

Further, it is preferable that these perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group or perfluorooxyalkylene group and the silicon atom in the component (B) are linked by a divalent linking group. As the divalent linking group, an alkylene group, an arylene group and a combination thereof, or an ether bond (oxygen atom), an amide bond, a carbonyl bond, an ester bond, a diorganosylylene group, etc. are interposed in these groups. It may be present, and examples thereof include the following divalent linking groups having 2 to 12 carbon atoms.

(In the formula, Ph is a phenyl group and Ph'is a phenylene group.)

Further, as the monovalent or divalent fluorine-containing organic group in the fluorine-containing organohydrogen siloxane of the component (B) and the monovalent substituent bonded to a silicon atom other than the hydrogen atom bonded to the silicon atom, for example, Alkyl groups such as methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group, octyl group and decyl group; alkenyl group such as vinyl group and allyl group; aryl group such as phenyl group, trill group and naphthyl group An aralkyl group such as a benzyl group or a phenylethyl group and a carbon such as a chloromethyl group, a chloropropyl group or a cyanoethyl group in which a part or all of the hydrogen atom of these groups is substituted with a chlorine atom, a cyano group or the like. Examples thereof include an unsubstituted or substituted monovalent hydrocarbon group having a number of 1 to 20, preferably 1 to 12.

The fluorine-containing organohydrogensiloxane (B) component may be cyclic, chain-like, three-dimensional network-like, or a combination thereof. The number of silicon atoms of this fluorine-containing organohydrogenpolysiloxane is not particularly limited, but is usually about 2 to 60, preferably about 3 to 30.

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

The amount of Si—H group contained in the fluorine-containing organohydrogensiloxane of the component (B) is preferably 0.00050 to 0.01000 mol / g, more preferably 0.00100 to 0.00800 mol / g. be. If the amount of Si—H groups contained in the fluorine-containing organohydrogen siloxane is too small, the crosslink density may be insufficient and the physical properties of the obtained cured product may deteriorate. It may foam or the physical properties of the resulting cured product may change significantly over time.

The blending amount of the component (B) is 1 mol of an alkenyl group such as a vinyl group, an allyl group or a cycloalkenyl group contained in the component (A), and a hydrosilyl group in the component (B), that is, a Si—H group. Is an amount of 0.5 to 3.0 mol, preferably 0.8 to 2.0 mol. If the number of hydrosilyl groups (≡Si—H) is too small, the crosslink density becomes insufficient, and as a result, a cured product cannot be obtained. Also, if there are too many hydrosilyl groups, they will foam during curing.

[(C) component]
The component (C) is a photoactive hydrosilylation reaction metal catalyst. In the photoactive hydrosilylation reaction metal catalyst, the metal in the catalyst is activated by irradiation with light, particularly near ultraviolet rays of 300 to 400 nm, and the alkenyl group in the component (A) and the hydrosilyl group in the component (B) are activated. It is a catalyst that promotes the addition reaction with. This photoactive hydrosilylation reaction metal catalyst mainly corresponds to a platinum group metal catalyst or a nickel metal catalyst, and the platinum group metal catalyst includes platinum-based, palladium-based, and rhodium-based metal complex compounds. Examples of the nickel-based metal catalyst include nickel-based, iron-based, and cobalt-based metal complex compounds. Among them, platinum-based metal complex compounds are preferable because they are relatively easily available and exhibit good catalytic activity.

Examples of the photoactive platinum-based metal complex compound include (η ⁵ -cyclopentadienyl) tri (σ-alkyl) platinum complex compound and β-diketonato platinum complex compound, and specifically (methylcyclo). Pentazienyl) trimethyl platinum (IV), (cyclopentadienyl) trimethyl platinum (IV), (1,2,3,4,5-pentamethylcyclopentadienyl) trimethyl platinum (IV), (cyclopentadi) Enyl) dimethylethyl platinum (IV), (cyclopentadienyl) dimethylacetyl platinum (IV), (trimethylsilylcyclopentadienyl) trimethylplatinum (IV), (methoxycarbonylcyclopentadienyl) trimethylplatinum (IV), ( Dimethylphenylsilylcyclopentadienyl) trimethylcyclopentadienyl platinum (IV), trimethyl (acetylacetonato) platinum (IV), trimethyl (3,5-heptandionate) platinum (IV), trimethyl (methylacetoacetate) Platinum (IV), bis (2,4-pentandionato) platinum (II), bis (2,4-hexandionato) platinum (II), bis (2,4-heptanzionato) platinum (II), bis ( 3,5-Heptandionato) Platinum (II), Bis (1-phenyl-1,3-Butandionato) Platinum (II), Bis (1,3-Diphenyl-1,3-Propanezionato) Platinum (II), Bis (Hexafluoroacetylacetonato) Platinum (II) and the like can be mentioned.

In using these catalysts, when it is a solid catalyst, it can be used in a solid state, but in order to obtain a more uniform cured product, the catalyst is dissolved in an appropriate solvent (A). It is preferable to use it by dissolving it in a linear polyfluoro compound as a component.

The type of solvent used is not particularly limited as long as the catalyst is soluble, but a solvent in which a part of hydrogen of a hydrocarbon group is replaced with hydrogen or a part of hydrogen of a hydrocarbon group is fluorine. It is more preferable to use a mixed solvent of the solvent substituted with and the solvent in which all of the hydrogens of the hydrocarbon group are substituted with fluorine, in that the catalyst can be more uniformly dispersed in the composition.

Examples of the solvent in which a part of the hydrogen of the hydrocarbon group is replaced with fluorine include 1,3-bis (trifluoromethyl) benzene, 1,2-bis (trifluoromethyl) benzene, and 1,4-bis (tri). Fluoromethyl) benzene, 1-methyl-3- (pentafluoroethyl) benzene, 1,1,1-trifluoro-3- [3- (trifluoromethyl) phenyl] propan-2-one, 4-fluoro-3 -Methyl benzoate (trifluoromethyl) n-butyl heptafluorobutyrate, ethyl 3,5-bis (trifluoromethyl) benzoate, 2-methyl-5- (trifluoromethyl) benzaldehyde, 2,3-dimethoxybenzo Trifluoride and the like can be mentioned.

Examples of the solvent in which all of the hydrogens of the hydrocarbon group are substituted with fluorine include octafluorotoluene, (1,1,2,3,3,3-hexafluoropropoxy) perfluorobenzene, and pentafluoroethyl 2,2. , 2-Trifluoroethyl ether, Florinate (manufactured by 3M), PF5060 (manufactured by 3M), perfluoropolyether oligomer and the like.

When the catalyst is used as a solution, the preferable mixing ratio of the linear polyfluoro compound (A) to the catalyst solution is in the range of 100: 0.01 to 1.00 (mass ratio). If the amount of the catalyst solution added is more than this range, it may affect the physical properties of the cured product, while if it is less than this range, it may cause poor dispersibility in the composition. .. Therefore, the concentration of the catalyst solution may be appropriately adjusted so as to be within the range of this mixing ratio.

The amount of the component (C) used is 0.1 to 500 ppm, preferably 1 to 100 ppm in terms of mass of the metal atom in the catalyst with respect to the component (A). If the amount used is too small, the photocurable composition cannot obtain sufficient photocurability, while if it is too large, it may foam or adversely affect the heat resistance of the cured product.

[(D) component]
The surface of the component (D) is hydrophobized with a surface treatment agent having a BET specific surface area of 0.1 m ² / g or more and both an alkyl group-containing reactive silicon compound and an alkenyl group-containing reactive silicon compound. It is a fine powder of silica. Thereby, it is possible to impart appropriate physical strength and good compression-resistant permanent strain resistance to the cured product obtained from the composition of the present invention.

The BET specific surface area of the silica fine powder (after surface hydrophobic treatment) is preferably 0.1 to 1,000 m ² / g, more preferably 1 to 500 m ² / g, still more preferably 10 to 400 m ² / g, and particularly. It is preferably 20 to 300 m ² / g. When the BET specific surface area is lower than 0.1 m ² / g, dispersion stability in the composition cannot be obtained and sedimentation occurs over time, and the desired physical strength and compression permanentity of the cured product are obtained due to a decrease in the reinforcing effect. Distortion characteristics may not be obtained. Further, when the BET specific surface area is higher than 1,000 m ² / g, adsorption of components occurs in the composition, and the amount added is small due to the high thickening effect, so that the cured product has the desired physical strength and compression permanent. Distortion characteristics may not be obtained. In the present invention, the BET specific surface area can be measured by N ₂ gas adsorption of the one-point method specified in JIS Z 8830.
Examples of the fine powder silica include dry silica (foam silica or fumed silica), precipitation method silica, gel method silica, wet silica such as colloidal silica, pulverized silica, and crystalline silica (quartz fine powder) molten spherical silica. However, among these, dry silica is most preferable because of its dispersion stability in the composition and its reinforcing effect on the cured product.

The hydrophobized silica fine powder is obtained by treating a hydroxyl group (silanol group) bonded to a silicon atom on the silica surface with a surface treatment agent for both an alkyl group-containing reactive silicon compound and an alkenyl group-containing reactive silicon compound. Be done.

The alkyl group-containing reactive silicon compound is not limited to the following, but is not limited to hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, 1,3-diethyl-1,1,3,3-tetra. Silazan compounds such as methyldisilazane, 1,3-dimethyl-1,1,3,3-tetraethyldisilazane, alkoxysilane compounds such as methyltrimethoxysilane, ethyltrimethoxysilane, and propyltrimethoxysilane, trimethylchlorosilane, triethyl. Examples thereof include chlorosilane compounds such as chlorosilane, tripropylchlorosilane, dimethyldichlorosilane, diethyldichlorosilane, and dipropyldichlorosilane, but it is preferable to use a silazane compound because of workability and reactivity with the silanol group on the silica surface. In particular, it is preferable to use hexamethyldisilazane and hexaethyldisilazane.

The alkenyl group-containing reactive silicon compound is not limited to the following, but is not limited to 1,3-divinyltetramethyldisilazane, 1,3-diallyltetramethyldisilazane, and 1,3-dibutenyltetramethyldisilazane. , 1,3-Dipentenyltetramethyldisilazane, 1,3-dihexenyltetramethyldisilazane, 1,3-diheptenyltetramethyldisirazane, 1,3-dioctenyltetramethyldisilazane, 1,3 -Cilazan compounds such as dinonenyltetramethyldisilazane, 1,3-didekenyltetramethyldisilazane, 1,3-divinyltetraethyldisilazane, 1,3-dimethyltetravinyldisilazane, vinyltrimethoxysilane, allyl. Examples thereof include alkoxysilane compounds such as trimethoxysilane and butenyltrimethoxysilane, and chlorosilane compounds such as dimethylvinylchlorosilane and allyldimethylchlorosilane. However, due to workability and reactivity with silanol groups on the silica surface, silazane compounds are used. It is preferable to use, and it is particularly preferable to use 1,3-divinyltetramethyldisilazane and 1,3-diallyltetramethyldisilazane.

The alkyl group-containing reactive silicon compound and the alkenyl group-containing reactive silicon compound may be treated with a single compound, or may be treated with a combination of a plurality of compounds.

When the silica fine powder is hydrophobized, the mol ratio of the alkenyl group-containing reactive silicon compound is 0.1 to 40 mol%, and the alkyl group-containing reactive silicon compound is 60 to 99.9 mol% (however, the alkyl group-containing reactive silicon compound). It is preferable to treat with 100 mol% in total of the silicon compound and the alkenyl group-containing reactive silicon compound, and when the alkenyl group-containing reactive silicon compound is less than 0.1 mol%, the desired rubber characteristics, particularly compression. If the permanent strain property is not obtained, or conversely, if it is more than 40 mol%, the obtained cured rubber product becomes hard and brittle, and the desired rubber physical property may not be obtained.

As a method of treatment using a surface treatment agent, the silica fine powder which has not been treated in advance is directly treated with a treatment agent in the form of a powder, or the treatment agent is diluted with an appropriate solvent for treatment. Is preferable. As such a diluting solvent, hexane, toluene, acetone and the like are used.

As a surface treatment method, a known technique can be usually adopted. For example, it is necessary to put the untreated silica fine powder and the surface treatment agent in a mechanical kneading device sealed at normal pressure or in a flow layer. Depending on the above, the mixing treatment is carried out at room temperature or under heating in the presence of an inert gas. In some cases, it may be humidified, and can be prepared by kneading and then drying.

The blending amount of the component (D) is 1 to 40 parts by mass with respect to 100 parts by mass of the component (A), and is preferably in the range of 5 to 20 parts by mass. When the blending amount is less than 1 part by mass, the physical strength of the obtained cured product cannot be obtained, while when it exceeds 40 parts by mass, the fluidity of the composition is deteriorated and the curing property by light is significantly deteriorated. there's a possibility that.

The total content of the component (A), the component (B), the component (C) and the component (D) in the composition of the present invention is preferably 70 to 100% by mass, preferably 80 to 100% by mass. Is more preferable, and 90 to 100% by mass is further preferable.

[(E) component]
The photocurable fluoropolyether-based rubber composition of the present invention may further contain, as the component (E), a conventionally known reaction control agent for the hydrosilylation reaction as long as the effects of the present invention are not impaired. Thereby, the composition can obtain a better storage stability. Examples of the reaction control agent include 1-ethynyl-1-hydroxycyclohexane, 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexin-3-ol, 3-methyl-1-pentene-. Examples thereof include acetylene alcohols such as 3-ol and phenylbutynol, and acetylene compounds such as 3-methyl-3-pentene-1-in and 3,5-dimethyl-3-hexene-1-in. Further, a fluorine-containing acetylene alcohol compound represented by the following structural formula, a polymethylvinylsiloxane cyclic compound, an organic phosphorus compound and the like can also be used as a reaction control agent.

Since these reaction control agents have different control capacities depending on their chemical structures, the addition amount should be adjusted to the optimum amount. In general, if the amount of the reaction control agent added is too small, long-term storage at room temperature cannot be obtained, and if the amount of the reaction control agent added is too large, the curability becomes dull and sufficient curability may not be obtained. There is sex.

[Other ingredients]
In the composition of the present invention, in order to enhance its practicality, in addition to the above-mentioned components (A) to (E), a plasticizer, a viscosity modifier, a flexibility-imparting agent, an inorganic filler, an adhesion promoter, etc. Various compounding agents such as an adhesive aid and a silane coupling agent can be added as needed. The blending amount of these additives is arbitrary as long as the effects of the present invention are not impaired, and the characteristics of the photocurable composition and the physical properties of the cured product are not impaired.

As a plasticizer, a viscosity modifier, and a flexibility-imparting agent, a polyfluoromonoalkenyl compound represented by the following formula (3) and / or a non-functional compound represented by the following formulas (4) and / or (5). A sex linear polyfluoro compound can be used in combination.

[In the formula (3), X'is the same as above, Rf ³ is the following formula (iii), and a is 0 or 1.

(In the formula (iii), f1 is an integer of 1 or more, preferably an integer of 2 to 100, t is 2 or 3, and f1 is p + q (average) and p + q (average) with respect to ^one Rf group of the component (A) above. It is preferable that it is smaller than the sum of r and the sum of u and v.)]

(In the formula (4), D is a group represented by the formula: C _s F _{2s + 1-} (s is 1 to 3), and c1 is an integer of 1 to 200, preferably an integer of 2 to 100. In addition, c1 is preferably smaller than the sum of p + q (average) and r with respect to the Rf ¹ group of the component (A), and the sum of u and v.)

(In the formula (5), D is a group represented by the formula: C _s F _{2s + 1-} (s is 1 to 3), and d1 and e1 are integers of 1 to 200, preferably 1 to 100, respectively. It is an integer, and the sum of d1 and e1 is less than or equal to the sum of p + q (average) and r with respect to the Rf ¹ group of the component (A), and the sum of u and v.)

Specific examples of the polyfluoromonoalkenyl compound represented by the above formula (3) include the following (note that the following f1'satisfies the requirements of the above f1).

Specific examples of the linear polyfluoro compound represented by the formulas (4) and (5) include the following (note that the sum of the following c1'and d1'and e1'is described above. It satisfies the requirements of C1 and the sum of d1 and e1).

(In the formula, c1'is an integer from 1 to 200.)

(In the formula, d1'is an integer of 1 to 200, e1'is an integer of 1 to 200, and d1'+ e1'= 2 to 200.)

The blending amount of the compounds of the formulas (3) to (5) is preferably 1 to 300 parts by mass with respect to 100 parts by mass of the component (A) in the present composition, particularly the linear polyfluoro compound of the formula (1). Is 50 to 250 parts by mass. Further, the viscosity (23 ° C.) by the rotational viscometer is preferably in the range of 5 to 100,000 mPa · s for the same reason as that of the linear polyfluoro compound.

Examples of the inorganic filler include reinforcing or semi-reinforcing fillers such as quartz powder, molten quartz powder, diatomaceous earth and calcium carbonate, inorganic pigments such as iron oxide, carbon black and cobalt aluminate, titanium oxide, iron oxide and carbon. Heat resistance improver such as black, cerium oxide, cerium hydroxide, zinc carbonate, magnesium carbonate, manganese carbonate, thermal conductivity imparting agent such as alumina, boron nitride, silicon carbide, metal powder, carbon black, silver powder, conductive zinc Examples thereof include a conductivity-imparting agent such as flower.

Further, in the present invention, if necessary, an adhesion promoter such as a carboxylic acid anhydride or a titanium acid ester, an adhesion imparting agent and / or a silane coupling agent can be added.

[Photocurable fluoropolyether-based rubber composition]
In the photocurable fluoropolyether-based rubber composition of the present invention, the above-mentioned components (A) to (D), preferably the components (A) to (E), and other optional components are mixed with a planetary mixer or a loss mixer. , A mixing device such as a Hobart mixer, and if necessary, a kneading device such as a kneader or a triple roll can be used to uniformly mix the mixture.

The method for producing the photocurable fluoropolyether-based rubber composition of the present invention is not particularly limited, and can be produced by kneading the above components. Further, it may be prepared as two kinds of compositions and mixed at the time of use.

Hereinafter, an example of a method for producing a photocurable fluoropolyether-based rubber composition will be shown when the components (A) to (E) are blended.

[Manufacturing method of base compound]
First, the component (D) is blended in the range of 10 to 50 parts by mass with respect to 100 parts by mass of the component (A) under heating or no heating conditions, and kneaded under heating / depressurizing conditions or heating / pressurizing conditions. To prepare a base compound in which the component (D) is uniformly dispersed in the component (A).

Here, the compounding / kneading of the component (A) and the component (D) is carried out by using a linear polyfluoro compound as the component (A) on the surface of the hydrophobized silica fine powder as the component (D). It is done to cover well. As a result, the component (B) is less likely to be adsorbed on the silica surface of the component (D), and the components (B) and (D) are less likely to aggregate with each other, whereby the photocurable fluoropolyether-based rubber composition is formed. This is because the viscosity of silica is reduced and the photocurability is improved. The mixing and kneading of the component (A) and the component (D) can be performed by a kneading device such as a planetary mixer, a gate mixer and a kneader.

The compounding ratio of the component (A) and the component (D) in the base compound varies depending on the type of the hydrophobized silica fine powder as the component (D), but with respect to 100 parts by mass of the component (A). The component (D) is preferably 10 to 50 parts by mass. When the component (D) is less than 10 parts by mass with respect to 100 parts by mass of the component (A), it is difficult to reduce the viscosity of the final compounding composition, and the viscosity may become very high. Further, when the component (D) exceeds 50 parts by mass with respect to 100 parts by mass of the component (A), heat generation during kneading becomes intense, the mechanical properties of the composition deteriorate, and the powder is blended in a machine. It can be difficult.

The temperature and time of compounding and kneading during the production of the base compound may be appropriately determined, but the heat treatment temperature is preferably 120 to 180 ° C., and the kneading is preferably carried out for 1 hour or more so that the components are uniformly dispersed.

Since the pressure at the time of blending and kneading differs depending on the apparatus used, it is preferable to carry out under pressurization or depressurization depending on the apparatus. For example, when kneading with a planetary mixer or a gate mixer, the pressure condition is preferably a reduced pressure of −0.05 MPa or less at a gauge pressure. Further, when kneading with a kneader, the pressure condition is preferably a gauge pressure of 0.4 to 0.6 MPa. The reason for performing the operation under this condition is that the component (A) easily gets wet (easily covers) the surface of the component (D).

[Manufacturing of photocurable fluoropolyether-based rubber composition]
A predetermined amount of the above-mentioned (A) component, (B) component, (C) component and (E) component is further added to the base compound composed of the (A) component and the (D) component obtained as described above. , A photocurable fluoropolyether-based rubber composition can be obtained by uniformly mixing.

In using the photocurable fluoropolyether-based rubber composition of the present invention, a fluorine-based solvent suitable for the intended use and purpose, for example, 1,3-bis (trifluoromethyl) benzene, fluorolinerto (3M). The composition may be dissolved in a desired concentration in perfluorobutylmethyl ether, perfluorobutylethyl ether, perfluoropolyether oligomer, a mixture thereof, or the like. In particular, it is preferable to use a solvent in thin film coating applications.

[Photo-curing method for photo-curable fluoropolyether-based rubber composition]
The produced photocurable fluoropolyether-based rubber composition can be cured by light irradiation. At the time of curing, the irradiated light has a maximum peak wavelength in the region of 300 to 400 nm in the emission spectrum, and the irradiance of each wavelength in the wavelength region shorter than 300 nm is preferably 5% or less of the irradiance of the maximum peak wavelength. Is 1% or less, more preferably 0.1% or less, that is, the closer it is to 0, the more preferable. Irradiation with light having a wavelength region shorter than 300 nm and having an irradiance greater than 5% of the irradiance of the maximum peak wavelength causes decomposition of the polymer terminal group, decomposition of a part of the catalyst, and the like. Therefore, it may not be possible to obtain a sufficient cured product.

The active light species used for curing the photocurable fluoropolyether rubber composition of the present invention is not particularly limited, but ultraviolet rays, particularly near ultraviolet rays having a maximum peak wavelength of 300 to 400 nm are preferable. .. The amount of ultraviolet irradiation (illuminance) for obtaining good curability is 100 mJ / cm ² to 100,000 mJ / cm ² , preferably 1,000 mJ / cm ² to 10,000 mJ / cm ² , more preferably 1,000 mJ / cm 2 to 100,000 mJ / cm 2, as the integrated light amount. It is 5,000 to 10,000 mJ / cm ² . When the ultraviolet irradiation amount (illuminance) is less than the above range, sufficient energy cannot be obtained to activate the photoactive hydrosilylation reaction catalyst in the composition, and it is possible that a sufficient cured product cannot be obtained. There is sex. In addition, when the ultraviolet irradiation amount (illuminance) exceeds the above range, the composition is irradiated with more energy than necessary, the polymer terminal groups are decomposed, and a part of the catalyst is inactivated. , It may not be possible to obtain a sufficient cured product.

The ultraviolet irradiation may be light having a plurality of emission spectra or light having a single emission spectrum. Further, the single emission spectrum may have a broad spectrum in the region from 300 nm to 400 nm. Light having a single emission spectrum is light having a peak (ie, maximum peak wavelength) in the range of 300 nm to 400 nm, preferably 350 nm to 380 nm. Examples of the light source for irradiating such light include an ultraviolet light emitting diode (ultraviolet LED) and an ultraviolet light emitting semiconductor element light source such as an ultraviolet light emitting semiconductor laser.

Examples of the light source for irradiating light having a plurality of emission spectra include a metal halide lamp, a xenon lamp, a carbon arc lamp, a chemical lamp, a sodium lamp, a low pressure mercury lamp, a high pressure mercury lamp, a lamp such as an ultrahigh pressure mercury lamp, and the like. Examples thereof include a gas laser such as, a liquid laser of an organic dye solution, and a solid laser in which a rare earth ion is contained in an inorganic single crystal.

When the light has a peak in a wavelength region shorter than 300 nm in the emission spectrum, or a wavelength having a wavelength larger than 5% of the emission illuminance of the maximum peak wavelength in the emission spectrum exists in the wavelength region shorter than 300 nm. (For example, when the emission spectrum is broad over a wide wavelength region), an optical filter removes light having a wavelength in a wavelength region shorter than 300 nm. As a result, the irradiance of each wavelength in the wavelength region shorter than 300 nm is set to 5% or less, preferably 1% or less, more preferably 0.1% or less, still more preferably 0% of the irradiance of the maximum peak wavelength. .. When a plurality of peaks are present in the wavelength region from 300 nm to 400 nm in the emission spectrum, the peak wavelength showing the maximum absorbance among them is set as the maximum peak wavelength. The optical filter is not particularly limited as long as it cuts wavelengths shorter than 300 nm, but known ones may be used. For example, a 365 nm bandpass filter or the like can be used. The illuminance and spectral distribution of ultraviolet rays can be measured with a spectroscopic irradiance meter, for example, USR-45D (Ushio Denki).

The light irradiation device is not particularly limited, and for example, an irradiation device such as a spot type irradiation device, a surface type irradiation device, a line type irradiation device, and a conveyor type irradiation device can be used.

When the photocurable fluoropolyether rubber composition of the present invention is cured, the light irradiation time is, for example, 1 to 300 seconds, preferably 10 to 200 seconds, more preferably 30 to 150 seconds, and 1 of the light irradiation. After about 60 minutes, particularly after 5 to 30 minutes, the photocurable composition loses its fluidity and a rubber elastic body (rubber cured product) can be obtained.

[Photo-curable fluoropolyether-based rubber cured product]
The photocurable composition of the present invention containing the above components (A) to (D), preferably the components (A) to (E) as main components, is excellent in chemical resistance and solvent resistance by the photocuring method. Moreover, it is possible to form a cured rubber product having low moisture permeability. It also has excellent compression set characteristics. The formation of the cured rubber product is easily carried out by a conventionally known method such as injecting the photocurable composition of the present invention into a suitable container or coating it on a suitable substrate and then irradiating it with light to cure it. be able to.

The photocurable fluoropolyether-based rubber cured product of the present invention is, for example, for automobiles, chemical plants, semiconductor production lines, analytical / physics and chemistry equipment, medical equipment, fuel cells, inkjet printers, aircraft, etc. It can be suitably used as a member for various purposes such as for an organic EL panel.

More specifically, the cured product of the present invention and the rubber product containing the cured product include, for example, rubber parts for automobiles, specifically, diaphragms, valves, sealing materials, etc .; rubber parts for chemical plants, specifically. Sealing materials such as diaphragms for pumps, valves, hoses, packings, oil seals, gaskets, sealing materials for repairing tank pipes, etc .; rubber parts for semiconductor manufacturing lines, specifically, equipment with which chemicals come into contact. Valves that require low friction and wear resistance, such as sealing materials for diaphragms, valves, packings, gaskets, etc .; rubber parts for analytical and physics and chemistry equipment, specifically, diaphragms for pumps, valves, sealing parts ( Packing, etc.); Rubber parts for medical equipment, specifically, pumps, valves, joints, etc .; Rubber parts for fuel cells, specifically, sealing materials for fuel cells; Rubber parts for inkjet printers; Rubber parts for aircraft; Rubber parts for organic EL panels; Other rubber parts; Specifically, tent film materials, sealants, molded parts, extruded parts, covering materials, copying machine roll materials, moisture-proof coating materials for electricity, potting materials for sensors, machine tools. It is useful for sealing materials, laminated rubber cloth, etc.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following example, the part indicates a mass part. The viscosity indicates the measured value at 23 ° C. (according to JIS K7117-1). The molecular weight indicates a polystyrene-equivalent number average molecular weight in GPC analysis using a fluorine-based solvent as a developing solvent. The specific surface area was measured by N ₂ gas adsorption by the one-point method specified in JIS Z 8830.

Preparation of Hydrophobized Silica Fine Powder [Synthesis Example 1]
BET specific surface area 300 m ² / g untreated dry silica fine powder (product name AEROSIL300: trade name manufactured by Nippon Aerosil Co., Ltd.) 100 g, 1,3-divinyltetramethyldisilazane 1.1 g (0.006 mol), and A mixture of 17.3 g (0.107 mol) of hexamethyldisilazan was added, and the mixture was heated and stirred at a temperature of 200 ° C. for 120 minutes and then cooled to prepare. The BET surface area of the obtained treated silica was 182 m ² / g.

[Synthesis Example 2]
Untreated dry silica fine powder with a specific surface area of 50 m ² / g (product name AEROSIL50: trade name manufactured by Nippon Aerosil Co., Ltd.) 1,3-divinyltetramethyldisilazane 0.19 g (0.001 mol) and hexa A mixture of 2.91 g (0.018 mol) of methyldisilazan was added, and the mixture was heated and stirred at a temperature of 200 ° C. for 120 minutes and then cooled to prepare. The BET surface area of the obtained treated silica was 41 m ² / g.

[Synthesis Example 3]
Untreated dry silica fine powder with a specific surface area of 50 m ² / g (product name AEROSIL50: trade name manufactured by Nippon Aerosil Co., Ltd.) 1,3-dioctenyltetramethyldisilazane 0.35 g (0.001 mol), And 2.91 g (0.018 mol) of hexamethyldisilazane was added, and the mixture was heated and stirred at a temperature of 200 ° C. for 120 minutes and then cooled to prepare. The BET surface area of the obtained treated silica was 35 m ² / g.

[Synthesis Example 4]
A mixture of 18.3 g (0.113 mol) of hexamethyldisilazane is added to 100 g of untreated dry silica fine powder (product name AEROSIL300: trade name manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 300 m ² / g, and the temperature is 200. After heating and stirring at ° C. for 120 minutes, the mixture was cooled and prepared. The BET surface area of the obtained treated silica was 195 m ² / g.

[Synthesis Example 5]
A mixture of 3.07 g (0.019 mol) of hexamethyldisilazane is added to 100 g of untreated dry silica fine powder (product name AEROSIL50: trade name manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 50 m ² / g, and the temperature is 200. After heating and stirring at ° C. for 120 minutes, the mixture was cooled and prepared. The BET surface area of the obtained treated silica was 43 m ² / g.

Production of base compound for photocurable fluoropolyether-based rubber composition [Production example]
Hydrophobization prepared in the above synthesis examples 1 to 5 in 100 parts of a polymer represented by the following formula (6) (viscosity 9,000 mPa · s, vinyl group amount 0.00013 mol / g, number average molecular weight 15,700). Twenty parts of the treated silica fine powder was added separately by a planetary mixer and kneaded for 1 hour (Table 1). Then, the mixture was heat-treated at 150 ° C. for 1 hour under reduced pressure (−0.08 to −0.10 MPa), cooled, and then dispersed with three rolls to produce base compounds 1 to 5. In addition, the viscosities of the base compounds 1 to 5 were measured (Table 1).

Preparation of Photocurable Fluoropolyether-based Rubber Composition [Example 1]
To 120 parts of the base compound prepared in Production Example 1, 33.3 parts of the polymer represented by the formula (6) was charged into a planetary mixer and mixed until uniform. To this, 0.08 part of a 1,3-bis (trifluoromethyl) benzene solution (platinum concentration 3.0% by mass) of (methylcyclopentadienyl) trimethylplatinum (IV), 1-ethynyl-1-hydroxycyclohexane 0.06 part of a toluene solution (5.0% by mass) and 3.5 parts of a fluorine-containing organohydrogensiloxane represented by the following formula (7) (Si—H group amount 0.00500 mol / g) were sequentially added and uniformly added. It was mixed so as to be. Then, the composition was prepared by performing a defoaming operation. Table 2 shows the compositions (unit: parts by mass) of Examples and Comparative Examples.

[Example 2]
In Example 1 above, the composition was prepared in the same manner except that the base compound used was changed to the one prepared in Production Example 2 (120 parts).

[Example 3]
In Example 1 above, the composition was prepared in the same manner except that the base compound used was changed to the one prepared in Production Example 3 (120 parts).

[Comparative Example 1]
In Example 1 above, the composition was prepared in the same manner except that the base compound used was changed to the one prepared in Production Example 4 (120 parts).

[Comparative Example 2]
In Example 1 above, the composition was prepared in the same manner except that the base compound used was changed to the one prepared in Production Example 5 (120 parts).

[Evaluation of storage stability]
The photocurable compositions obtained in the above Examples and Comparative Examples were left at 23 ° C. for 2 weeks in the dark, and compared with the initial viscosity. The results are shown in Table 2. The viscosity was measured in accordance with JIS K7117-1 using a TV-10U type rotational viscometer (rod No. H7, 23 ° C., 50 rpm) manufactured by Toki Sangyo Co., Ltd. The results are shown in Table 2.

[Evaluation of photocurability]
The compositions obtained from the above Examples and Comparative Examples were applied on an aluminum substrate having a sample thickness of 1.0 mm at 25 ° C., UV irradiation was performed, and the change in elastic modulus at 25 ° C. with time was measured. .. Ares G2 manufactured by TA Instruments is used for measurement, and a 320-390 nm bandpass filter is attached to OmniCure S2000 manufactured by Lumen Dynamics for UV irradiation, and irradiation is performed at 365 nm with a UV illuminance of 100 mW / cm ² for 90 seconds. gone. The results are shown in Table 3.

From the results in Table 2, it was found that the photocurable fluoropolyether-based rubber composition of the present invention exhibited good storage stability at 23 ° C. in the light-shielded state.
Further, from the results in Table 3, it was found that the photocurable fluoropolyether-based rubber composition of the present invention exhibits good curability at 25 ° C. after UV irradiation.

[Evaluation of rubber properties of photo-cured products]
The compositions obtained in the above Examples and Comparative Examples were poured into a mold of (H) × (D) × (t) = 105 mm × 85 mm × 2 mm, respectively, and a surface irradiation type UV-LED irradiator (CCS Co., Ltd.) (Manufactured) was used for light irradiation. ^At that time, irradiation was performed at 100 mW / cm for 90 seconds so that the integrated light amount of 365 nm light was 9,000 mJ / cm ² . Immediately after the light irradiation, the light was shielded and the mixture was allowed to stand at 23 ° C. for 24 hours. After 24 hours, JIS K6250, 6251, 625
The physical characteristics of rubber were evaluated according to 3 and 6262, respectively. The results are shown in Table 4.

From the results in Table 4, it was found that the photocured product of the composition of the present invention was excellent in compression set.

Claims (8)

(A) A linear polyfluoro compound having two or more alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain, which is represented by the following formula (1) and has an alkenyl group. Linear polyfluoro compound having an amount of 0.00005 to 0.00050 mol / g: 100 parts by mass,

[In formula (1), X is -CH _2- , -CH ₂ O-, -CH ₂ OCH _2- or -Y-NR ¹ -CO-
(Here, Y is -CH _2- , -Si (CH ₃ ) ₂ CH ₂ CH ₂ CH _2- , -Si (CH ₃ ) (CH = CH ₂ ) CH ₂ CH ₂ CH _2- , -Si (CH) = CH ₂ ) ₂ CH ₂ CH ₂ CH ₂ -or the following structural formula (Z)

(In equation (Z), R ³ and R ⁴ are independently -CH ₃ or -CH = CH ₂ , respectively.)
It is an o-, m- or p-silylphenylene group represented by, and R ¹ is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group).
X'is -CH _2- , -OCH _2- , -CH ₂ OCH _2- or -CO-NR ² -Y'-
(Here, Y'is -CH _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) _2- , -CH ₂ CH ₂ CH ₂ Si (CH ₃ ) (CH = CH ₂ )-, -CH ₂ CH ₂ CH ₂ Si (CH = CH ₂ ) ₂ -or the following structural formula (Z')

(In equation (Z ^' ), R ^3'and R 4'are independently -CH ₃ or -CH = CH _2. )
It is an o-, m- or p-silylphenylene group represented by, R ² is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group), and g is independently 0 or 1.
Rf ¹ is a divalent perfluoropolyether group represented by the following formula (i) or (ii-1).

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

(In equation (ii-1), u1 is an integer of 1 to 200, and v1 is an integer of 1 to 50.) ]
(B) A fluorine-containing organohydrogensiloxane having two or more hydrogen atoms directly connected to a silicon atom in one molecule, and one or more in one molecule.

(In the formula, g is an integer of 1 to 20.) A monovalent perfluoroalkyl group represented by.

(In the formula, f is an integer of 1 to 200 and h is an integer of 1 to 3.) A monovalent perfluorooxyalkyl group represented by.

(In the formula, g is an integer of 1 to 20.) A divalent perfluoroalkylene group represented by.
And / or

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

(In the formula, d and e are integers of 1 to 50, respectively.) It has a divalent perfluorooxyalkylene group, the number of silicon atoms is 2 to 60, and the amount of Si—H group is 0. Fluoro-containing organohydrogensiloxane which is .00005 to 0.01000 mol / g and is any of cyclic, chain, three-dimensional network and combinations thereof: Si—H with respect to 1 mol of the alkenyl group of the component (A). Amount of 0.5 to 3.0 mol as a base,
(C) Photoactive hydrosilylation reaction metal catalyst: 0.1 to 500 ppm in terms of mass of metal atom with respect to the component (A), and
(D) Silica fine powder having a BET specific surface area of 0.1 m ² / g or more and having a surface hydrophobicized with an alkyl group-containing reactive silicon compound and an alkenyl group-containing reactive silicon compound, the alkenyl group. The ratio of the molar ratio of the content-reactive silicon compound is 0.1 to 40 mol% and the alkyl group-containing reactive silicon compound is 60 to 99.9 mol% (however, the alkyl group-containing reactive silicon compound and the alkenyl group-containing reactive silicon compound are contained. Silica fine powder treated with 100 mol% in total): (A) Contains 1 to 40 parts by mass with respect to 100 parts by mass of the component, and conforms to JIS K6262 at 150 ° C. × 70 hours. A photocurable fluoropolyether-based rubber composition that gives a cured rubber composition having a compression set of 11% or less. The photocurable fluoropolyether-based rubber composition according to claim 1, wherein the silica fine powder of the component (D) is surface-treated with a silazane compound having an alkyl group and a silazane compound having an alkenyl group. The photocurable fluoropolyether-based rubber composition according to claim 1 or 2, wherein the silica fine powder of the component (D) is a dry silica fine powder. The invention according to any one of claims 1 to 3, wherein Rf ¹ of the component (A) is a group selected from the following (i-1), (i-2) and (ii-1). Photocurable fluoropolyether-based rubber composition.

(In equation (i-1), p1 and q1 are integers of 1 to 150, respectively, and p1 + q1 (average) = 2 to 200. L is an integer of 2 to 6.)

(In equation (i-2), p2 and q2 are integers of 1 to 150, respectively, and p2 + q2 (average) = 2 to 200. L is an integer of 2 to 6.)

(In equation (ii-1), u1 is an integer of 1 to 200, and v1 is an integer of 1 to 50.) The perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group or perfluorooxyalkylene group in the component (B) and the silicon atom in the component (B) are linked by a divalent linking group, and the divalent group is used. The linking group according to claim 1 to 4 is an alkylene group, an arylene group and a combination thereof, or a group thereof in which an ether bond, an amide bond, a carbonyl bond, an ester bond, or a diorganosylylene group is interposed. The photocurable fluoropolyether-based rubber composition according to any one of the following items. The method according to any one of claims 1 to 5, wherein the photoactive hydrosilylation reaction metal catalyst of the component (C) is a (η ⁵ -cyclopentadienyl) tri (σ-alkyl) platinum (IV) complex. A photocurable fluoropolyether-based rubber composition. The photocurable fluoropolyether-based rubber composition according to any one of claims 1 to 6, which comprises a reaction control agent for a hydrosilylation reaction as a component (E). The cured product of the photocurable fluoropolyether-based rubber composition according to any one of claims 1 to 7.