JP2012122024A - Adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive sheet which has excellent solvent resistance, does not cause an insulation defect, has excellent heat resistance and air-tightness, and has rubber elasticity.SOLUTION: The adhesive sheet 1 is obtained by providing a supporting layer 3 with an adhesive layer 2 made of a fluororesin gel. The fluororesin gel is composed of a curable perfluoropolyether gel composition at least including: (A) a straight chain perfluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain; (B) an organosilicon compound having at least two hydrogen atoms linked to silicon atoms in one molecule; (C) a hydrosilylation reaction catalyst; (D) a polyfluoromonoalkenyl compound having one alkenyl group in one molecule and also having a perfluoropolyether structure in the main chain; and (E) a straight chain polyfluoro compound.

Description

  The present invention relates to a pressure-sensitive adhesive sheet, in particular, fixing various machines, electrical / electronic components, plastic molded products, etc., temporarily fixing various components, etc. during manufacturing and inspection, building materials, signboards, transportation The present invention relates to a pressure-sensitive adhesive sheet suitable for use as a masking material or the like when a paint is placed on a machine or the like.

  Usually, the pressure-sensitive adhesive sheet is composed of a support layer and a pressure-sensitive adhesive layer. Conventionally, a nonwoven fabric or a plastic film is mainly used for the support layer, and the pressure-sensitive adhesive layer is a rubber-based pressure-sensitive adhesive mainly composed of natural rubber, Silicone pressure-sensitive adhesives (including silicone gel, the same applies hereinafter) mainly composed of polydimethylsiloxane rubber or the like, or acrylic pressure-sensitive adhesives composed mainly of n-butyl acrylate are mainly used. In addition, in order to improve the stress relaxation property and followability of the pressure-sensitive adhesive sheet, a pressure-sensitive adhesive sheet imparted with rubbery elasticity and flexibility is also known, and the support layer of such a pressure-sensitive adhesive sheet has a rubber such as silicone rubber. And a silicone gel is used for the adhesive layer.

  However, rubber adhesives, silicone adhesives, and acrylic adhesives used in the adhesive layer of conventional adhesive sheets all generate adhesive force, so the molecular weight of the molecular chain that is the main component is small. The crosslink density is also low. Further, since these pressure-sensitive adhesives often have an affinity with an organic solvent, the pressure-sensitive adhesive layer made of the above pressure-sensitive adhesive easily absorbs the organic solvent and swells when the organic solvent is present. And as a result of swelling, the adhesive force of the adhesive layer was reduced. That is, the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer of the conventional pressure-sensitive adhesive sheet has no solvent resistance.

  Among the above-mentioned pressure-sensitive adhesives, in particular, acrylic pressure-sensitive adhesives tend to migrate depending on the substrate to which unreacted monomers contained in the pressure-sensitive adhesive are attached. Moreover, since Tg exists in the hardened | cured adhesive, when it heats, the malfunction which a deformation | transformation or adhesive strength falls occurs (patent document 1). That is, the acrylic adhesive was not particularly heat resistant.

  Of the above-mentioned pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives contain a large amount of low molecular siloxane and silicone oil (Patent Document 2). Therefore, if there is a part where the electrical connection state repeats ON / OFF, for example, a coil part inside a motor, a contact of a relay, a contact of a switch, etc. near the adhesive sheet using the silicone-based adhesive, the silicone-based adhesive The low molecular siloxane and silicone oil contained in the film become silicon oxide and precipitate on each part such as a coil part, and as a result, an insulation failure may occur. That is, the silicone-based pressure-sensitive adhesive was not particularly resistant to insulation.

  Furthermore, when using a pressure sensitive adhesive sheet using a silicone pressure sensitive adhesive in the semiconductor manufacturing process or connector manufacturing process, the silicone oil contained in the silicone pressure sensitive adhesive oozes out in the vicinity of the part where the pressure sensitive adhesive sheet is peeled off. As a result, the adhesive strength decreases. Further, in the worst case, there is a problem peculiar to a silicone-based pressure-sensitive adhesive that dropping off may occur. In particular, when an adhesive sheet is used as an elastic body inside the IC package, there is a high possibility that such a problem such as dropping will occur during contact bonding in the semiconductor manufacturing process. In addition, since silicone has a high gas permeability, it may not be used in applications that require airtightness. That is, the silicone pressure-sensitive adhesive was not particularly airtight.

  In order to solve such a problem, an adhesive rubber in which a fluorine-based elastomer that is neither a silicone-based adhesive nor an acrylic adhesive is laminated has been proposed, but since an adhesive is laminated on a film, it is elastic. Can not be obtained (Patent Document 3), and there is a description of laminating fluororubbers with different adhesive strengths, but no detailed effective structure identification has been presented, and solvent resistance is required No mention is made of use in applications or applications requiring airtightness (Patent Document 4).

  It has also been proposed to laminate various types of pressure-sensitive adhesives on the fluororesin film (Patent Documents 5 to 8). Furthermore, it has also been proposed to laminate an acrylic fluorine-containing copolymer pressure-sensitive adhesive on various resins (Patent Document 9).

  However, even with these pressure-sensitive adhesive sheets, the elastic change with respect to deformation, solvent-resistant adhesive strength, and heat resistance were insufficient. Therefore, it has solvent resistance that does not decrease the adhesive strength even when it comes into contact with an organic solvent, and has insulation fault resistance that does not cause an insulation fault even if it is used near the contact portion where the electrical connection state repeats ON / OFF repeatedly. However, there has been a demand for the development of a pressure-sensitive adhesive sheet that has heat resistance that does not decrease deformation and adhesiveness even when used near a portion where heat is applied, has good airtightness, and has rubber elasticity.

JP 2010-37514 A JP 2004-025516 A JP 2004-292529 A JP 2009-013313 A JP 07-238264 A Japanese Patent Laid-Open No. 09-062188 JP 2001-354924 A JP 2010-121066 A JP 2004-292529 A

  The present invention has been made in order to solve the above-mentioned problems, and has solvent resistance that does not decrease the adhesive strength even when contacted with an organic solvent, and is in the vicinity of a contact portion where the electrical connection state repeats ON / OFF. Has insulation failure resistance that does not cause insulation failure even when used, has heat resistance that does not decrease deformation or tackiness even when used near heat, has good airtightness, rubber elasticity It aims at providing the adhesive sheet which has this. In particular, adhesive sheets with such characteristics can be used to fix various machines, electrical / electronic parts, plastic molded parts, etc., temporarily fix various parts, etc. during manufacturing and inspection, building materials, signboards, etc. The pressure-sensitive adhesive sheet can be suitably used as a masking material when a paint is placed on a transportation machine or the like.

In order to solve the above problems, in the present invention, the pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer made of a fluororesin gel on one or both sides of a support layer, and the fluororesin gel is at least
(A) Linear perfluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain: 30 to 90 parts by mass
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: effective amount of curing;
(C) Hydrosilylation reaction catalyst: catalyst amount,
(D) Polyfluoromonoalkenyl compound having one alkenyl group in one molecule and a perfluoropolyether structure in the main chain: 10 to 70 parts by mass (total of components (A) and (D) And (E) linear polyfluoro compound: a pressure-sensitive adhesive sheet comprising a curable perfluoropolyether gel composition containing 0 to 100 parts by mass. provide.

  Thus, the adhesive sheet having an adhesive layer made of a fluororesin gel on one or both sides of the support layer, wherein the fluororesin gel contains at least a predetermined amount of the components (A) to (E). If it is made of a fluoropolyether gel composition, it has solvent resistance that does not decrease the adhesive strength even when it comes into contact with an organic solvent, and it can be used near the contact portion where the electrical connection state repeats ON / OFF. A pressure-sensitive adhesive sheet that has a resistance to insulation that does not cause an insulation failure, has heat resistance that does not decrease deformation or tackiness even when used in the vicinity of heat, has good airtightness, and has rubber elasticity It becomes.

［式中、Ｘは−ＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＨ_２ＯＣＨ_２−、及び−Ｙ−ＮＲ^１−ＣＯ−（但し、Ｙは−ＣＨ_２−又は下記構造式（Ｚ）で示される基であり、Ｒ^１は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかの基である。Ｘ’は−ＣＨ_２−、−ＯＣＨ_２−、−ＣＨ_２ＯＣＨ_２−、及び−ＣＯ−ＮＲ^２−Ｙ’−（但し、Ｙ’は−ＣＨ_２−又は下記構造式（Ｚ’）で示される基であり、Ｒ^２は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかの基である。ｐは独立に０又は１であり、ｒは２〜６の整数であり、ｍ、ｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が５０〜６００となる整数である。

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）］ The component (A) is preferably a linear perfluoropolyether compound represented by the following general formula (1).

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 50 to 600.

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)]

  Thus, if the component (A) is a linear perfluoropolyether compound represented by the general formula (1), solvent resistance, insulation resistance, heat resistance, air tightness, rubber elasticity In addition, it is preferable because the pressure-sensitive adhesive sheet is less swelled with various organic solvents, has a low viscosity, is excellent in workability, and is practical.

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）
ｐは０又は１であり、Ｒｆ^１は下記一般式で表わされる基である。
Ｆ−［ＣＦ（ＣＦ_３）ＣＦ_２Ｏ］_ｗ−ＣＦ（ＣＦ_３）−
（式中、ｗは１〜５００の整数である。）］ Furthermore, the component (D) is preferably a polyfluoromonoalkenyl compound represented by the following general formula (2).
Rf ^1- (X ′) _p —CH═CH ₂ (2)
[Wherein, X ′ represents —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ represents —CH ₂ — or the following structural formula (Z And R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group.).

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)
p is 0 or 1, and Rf ¹ is a group represented by the following general formula.
_{F- [CF (CF 3) CF} 2 O] w -CF (CF 3) -
(Wherein w is an integer of 1 to 500)]

  Thus, if the component (D) is a polyfluoromonoalkenyl compound represented by the above general formula (2), the pressure-sensitive adhesive has better solvent resistance, insulation resistance, heat resistance, and airtightness. Since it becomes a sheet | seat, it is preferable.

  Further, the adhesive layer is made of the fluororesin gel having a three-dimensional network structure obtained by addition crosslinking of the curable perfluoropolyether gel composition, and the JIS-K 2220 of the fluororesin gel. Is preferably 30 to 200 °.

  Thus, when the penetration is softer around 200 °, the adhesion of the adhesive layer to the adherend is good, and when the penetration is harder around 30 °, the fluororesin gel itself has strength. Therefore, the adhesive strength is high. Moreover, if the penetration is 200 ° or less, it is possible to suppress the loss of the strength of the fluororesin gel itself, and even if it is once adhered to the adherend, a part of the adhesive layer is removed from the adherend. It is preferable because it can be suppressed. Moreover, if it is 30 degrees or more, since it can suppress that the adhesiveness to a to-be-adhered body falls, it is preferable.

  Furthermore, the support layer is preferably made of fluororubber.

  As described above, if the support layer is made of fluororubber, the support layer also has solvent resistance, insulation failure resistance, heat resistance, and airtightness, and more excellent elasticity and solvent resistance. Since it becomes an adhesive sheet, it is preferable.

The fluororubber is at least
(A) having at least two alkenyl groups in one molecule and -C _a F _2a O- in the main chain
(In the formula, a is an integer of 1 to 6.)
A linear perfluoropolyether compound having a number average molecular weight of 3,000 to 100,000 having a perfluoropolyether structure containing a repeating unit represented by: 100 parts by mass,
(B) a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: the molar ratio of SiH groups in component (b) to alkenyl groups in component (a) is 0.4 to An amount of 5.0,
(C) hydrosilylation reaction catalyst: catalyst amount, and (d) silica-based filler: 1 to 100 parts by mass,
It is preferable that it is obtained by addition-crosslinking a fluorine-containing curable composition containing.

  Thus, if the fluororubber is obtained by addition-crosslinking a fluorine-containing curable composition containing at least a predetermined amount of the above components (a) to (d), more solvent resistance and insulation resistance Since it becomes an adhesive sheet which has a support layer excellent in property, heat resistance, airtightness, and elasticity, it is preferable.

（式中、ａは１〜６の整数であり、ｑは２０〜６００の整数である。） Furthermore, the component (a) is preferably a linear perfluoropolyether compound having a perfluoropolyether structure represented by the following general formula (3).

(In the formula, a is an integer of 1 to 6, and q is an integer of 20 to 600.)

  Thus, if the component (a) is a linear perfluoropolyether compound having a perfluoropolyether structure represented by the general formula (3), solvent resistance, insulation resistance, heat resistance It is preferable because the pressure-sensitive adhesive sheet has a support layer that is less swelled with various organic solvents, in addition to its property, airtightness, and elasticity.

［式中、Ｘは−ＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＨ_２ＯＣＨ_２−、及び−Ｙ−ＮＲ^１−ＣＯ−（但し、Ｙは−ＣＨ_２−又は下記構造式（Ｚ）で示される基であり、Ｒ^１は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかである。Ｘ’は−ＣＨ_２−、−ＯＣＨ_２−、−ＣＨ_２ＯＣＨ_２−、及び−ＣＯ−ＮＲ^２−Ｙ’−（但し、Ｙ’は−ＣＨ_２−又は下記構造式（Ｚ’）で示される基であり、Ｒ^２は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかである。ｐは独立に０又は１であり、ｒは２〜６の整数であり、ｍ、ｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が２０〜６００となる整数である。］

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。） The component (a) is preferably a linear perfluoropolyether compound represented by the following general formula (4).

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 20 to 600. ]

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)

  Thus, when the component (a) is a linear perfluoropolyether compound represented by the general formula (4), solvent resistance, insulation resistance, heat resistance, airtightness, and elasticity In addition, the pressure-sensitive adhesive sheet having a support layer with less swelling with respect to various organic solvents is preferable.

  Further, the component (b) is any one of at least one monovalent perfluoro group, monovalent perfluorooxy group, divalent perfluoro group, and divalent perfluorooxy group in at least one molecule. And a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to a silicon atom.

  Such a component (b) is preferable because compatibility with the component (a), dispersibility, and uniformity after curing can be improved.

In addition, the component (d) is preferably a silica-based filler having a BET specific surface area of 30 m ² / g or more and having a hydrophobic surface.

Thus, if the component (d) is a BET specific surface area of 30 m ² / g or more, the mechanical strength can be improved, and if the silica-based filler whose surface is hydrophobized is sufficient This is preferable because it can increase the mechanical strength and suppress adverse effects such as abnormally high viscosity of the fluorine-containing curable composition.

  Furthermore, it is preferable that the rubber hardness of the fluororubber is in the range of 10 to 80 in durometer type A conforming to JIS K 6253 [durometer A].

  Thus, if the hardness is 10 or more, it is preferable because the strength is sufficient, and if it is 80 or less, the pressure-sensitive adhesive sheet has good flexibility and elasticity, and is particularly suitable for temporary fixing. Therefore, it is preferable.

  Moreover, it is preferable that the adhesive force with respect to the glass of the said fluororesin gel is the range of 0.5-5 N / 25mm.

  Thus, if the adhesive force with respect to the glass of the said fluororesin gel is the range of 0.5-5N / 25mm, it is preferable from a viewpoint of rework property and removability, and if it is 0.5N / 25mm or more especially, it will be adhesive It is preferable because peeling can be suppressed during use without being too low, and if it is 5 N / 25 mm or less, peeling is easy when re-peeling is required, and workability is improved, which is preferable.

  As described above, the pressure-sensitive adhesive sheet of the present invention having the pressure-sensitive adhesive layer made of the fluororesin gel has solvent resistance, insulation failure resistance, heat resistance, and airtightness, and has the flexibility required for the pressure-sensitive adhesive sheet (rubber It can be used even when the conventional adhesive sheet is difficult to use while maintaining elasticity.

  That is, the pressure-sensitive adhesive sheet of the present invention is used, for example, in masking for paints that may come into contact with an organic solvent or the like, in a surface mounting process such as an IC package, or in a bonding process between a substrate and a semiconductor chip inside the IC package. However, it can be used without worrying about the decrease in adhesive strength due to the absorption and swelling of organic solvents in electrical and electronic parts cleaning processes, etc. (solvent resistance), such as low molecular siloxanes, silicone oils or low molecular monomers Because it contains almost no free components, it should be used without worrying about insulation failure even in parts where the electrical connection state repeats ON / OFF, relay contacts, switch contacts, or IC mounting parts. Can be deformed (insulation failure resistance), and its deformation and adhesiveness decrease even when used near heated parts Can be used (heat resistance), can be used in areas where airtightness is required (airtightness), and has adhesive stability over time after application, and peeled off for rework Even in this case, the gel material does not remain in the affixed portion and can be used without any trouble even when reapplied (reworkability, removability).

It is sectional drawing which shows one embodiment of the adhesive sheet of this invention.

Hereinafter, although the adhesive sheet of this invention is demonstrated in detail, this invention is not limited to these.
As described above, it has been desired to develop a pressure-sensitive adhesive sheet having solvent resistance, insulation failure resistance, heat resistance, good airtightness, and rubber elasticity.

  That is, as a result of intensive research to achieve the above-mentioned problems, the present inventor should be a pressure-sensitive adhesive sheet using a fluororesin gel having high solvent resistance and containing almost no low-molecular siloxane or silicone oil for the pressure-sensitive adhesive layer. It was found that the sheet has solvent resistance, insulation resistance, heat resistance, good airtightness and rubber elasticity, and based on this knowledge, the material structure and composition of the adhesive sheet were studied As a result, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer made of a fluororesin gel on one side or both sides of the support layer, wherein the fluororesin gel contains at least a predetermined amount of the components (A) to (D). As a result, it was found that the pressure-sensitive adhesive sheet has solvent resistance, insulation resistance, heat resistance, good airtightness and rubber elasticity, and the present invention has been completed.

The present invention is an adhesive sheet having an adhesive layer made of a fluororesin gel on one side or both sides of a support layer, wherein the fluororesin gel is at least
(A) Linear perfluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain: 30 to 90 parts by mass
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: effective amount of curing;
(C) Hydrosilylation reaction catalyst: catalyst amount,
(D) Polyfluoromonoalkenyl compound having one alkenyl group in one molecule and a perfluoropolyether structure in the main chain: 10 to 70 parts by mass (total of components (A) and (D) And (E) linear polyfluoro compound: a pressure-sensitive adhesive sheet comprising a curable perfluoropolyether gel composition containing 0 to 100 parts by mass. provide.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the pressure-sensitive adhesive sheet of the present invention, wherein 1 is a pressure-sensitive adhesive sheet according to the present invention, 2 is a pressure-sensitive adhesive layer, and 3 is a support layer. As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 of the present invention has a pressure-sensitive adhesive layer 2 provided on the surface of a support layer 3. The pressure-sensitive adhesive layer 2 is a layer made of a fluororesin gel in which the curable perfluoropolyether gel composition according to the present invention has a three-dimensional network structure with a low crosslinking density.

[Fluororesin gel]
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention comprises a fluororesin gel comprising a curable perfluoropolyether gel composition containing the components (A) to (E).

<(A) component>
The component (A) of the present invention comprises a linear perfluoropolyether structure having at least two alkenyl groups in one molecule and a perfluoropolyether structure, preferably a divalent perfluoroalkyl ether structure in the main chain. It is a fluoropolyether compound.

Here, examples of the perfluoroalkyl ether structure include those containing a number of repeating units of —C _a F _2a O— (wherein a in each unit is an integer of 1 to 6). Examples thereof include those represented by the following general formula (5).
(C _a F _2a O) _q (5)
(In the formula, a is an integer of 1 to 6, and q is an integer of 50 to 600, preferably 50 to 400, more preferably 50 to 200.)

Examples of the repeating unit —C _a F _2a O— contained in the above formula (5) include the following units. In addition, the said perfluoroalkyl ether structure may be comprised by 1 type of these repeating units individually, and the combination of 2 or more types may be sufficient as it.
—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-
Of these, the following repeating units are particularly preferred.
—CF ₂ O—
-CF ₂ CF ₂ O-
-CF ₂ CF ₂ CF ₂ O-
-CF (CF ₃ ) CF ₂ O-

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。） This linear perfluoropolyether compound (A) has at least two alkenyl groups in one molecule. The alkenyl group is preferably a group having ₂ to 8 carbon atoms, particularly 2 to 6 carbon atoms, and having a CH ₂ ═CH— structure at the terminal, such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, A group having a CH ₂ ═CH— structure at the end, such as a butenyl group or a hexenyl group, particularly a vinyl group or an allyl group is preferred. This alkenyl group may be directly bonded to the end of the main chain of the linear perfluoropolyether compound, or may be a divalent linking group such as —CH ₂ —, —CH ₂ O—, —CH. ₂ OCH ₂ —, and —Y—NR ¹ —CO— (where Y is —CH ₂ — or a group represented by the following structural formula (Z), R ¹ is a hydrogen atom, a methyl group, a phenyl group, and Or any one of allyl groups). In particular, the alkenyl group is preferably bonded to both ends of the linear perfluoropolyether compound.

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）
Ｒｆ^２は二価のパーフルオロポリエーテル構造を示し、上記式（５）、即ち（Ｃ_ａＦ_２ａＯ）_ｑで示されるものが好ましい。Ｑは炭素数１〜１５の二価の炭化水素基であり、エーテル結合を含んでいてもよく、具体的にはアルキレン基、エーテル結合を含んでいてもよいアルキレン基である。ｐは独立に０又は１である。］ Examples of such a linear perfluoropolyether compound of component (A) include polyfluorodialkenyl compounds represented by the following general formula (6) or (7).
_{CH 2 = CH- (X) p} -Rf 2 - (X ') p -CH = CH 2 (6)
_{CH 2 = CH- (X) p} -Q-Rf 2 -Q- (X ') p -CH = CH 2 (7)
[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group).

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)
Rf ² represents a divalent perfluoropolyether structure and is preferably represented by the above formula (5), that is, (C _a F _2a O) _q . Q is a C1-C15 divalent hydrocarbon group which may contain an ether bond, specifically an alkylene group or an alkylene group which may contain an ether bond. p is independently 0 or 1. ]

［式中、Ｘは−ＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＨ_２ＯＣＨ_２−、及び−Ｙ−ＮＲ^１−ＣＯ−（但し、Ｙは−ＣＨ_２−又は下記構造式（Ｚ）で示される基であり、Ｒ^１は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかの基である。Ｘ’は−ＣＨ_２−、−ＯＣＨ_２−、−ＣＨ_２ＯＣＨ_２−、及び−ＣＯ−ＮＲ^２−Ｙ’−（但し、Ｙ’は−ＣＨ_２−又は下記構造式（Ｚ’）で示される基であり、Ｒ^２は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかの基である。ｐは独立に０又は１であり、ｒは２〜６の整数であり、ｍ、ｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が５０〜６００となる整数である。

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）］ Such a linear perfluoropolyether compound of component (A) is preferably a linear perfluoropolyether compound represented by the following general formula (1).

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 50 to 600.

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)]

  As described above, when the component (A) is a linear perfluoropolyether compound represented by the general formula (1), it has solvent resistance, insulation failure resistance, heat resistance, and airtightness. Swelling with respect to various organic solvents is further reduced, the viscosity is low, and the pressure-sensitive adhesive sheet is excellent in workability and practicality, which is preferable.

  The linear perfluoropolyether compound represented by the general formula (1) has a weight average molecular weight in terms of polyethylene by gel permeation chromatography (GPC) of 10,000 to 100,000, particularly 10,000 to 50,000. It is desirable that When the weight average molecular weight is 10,000 or more, it is preferable because swelling with respect to gasoline and various organic solvents becomes small. In particular, the swelling with respect to toluene is less than 6% and satisfies the characteristics as a member requiring toluene resistance. can do. Moreover, when the said weight average molecular weight is 100,000 or less, since a viscosity is low and it is excellent in workability | operativity and practicality, it is preferable.

（式中、ｍ、ｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が５０〜６００となる整数である。ｍ、ｎはそれぞれ０〜２００の整数であることが好ましく、またｍとｎの和が５０〜２００となる整数であることが好ましい。） Specific examples of the linear perfluoropolyether compound represented by the general formula (1) include those represented by the following formula.

(In the formula, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 50 to 600. m and n are each preferably an integer of 0 to 200, It is preferably an integer such that the sum of m and n is 50 to 200.)

  Furthermore, in the present invention, in order to adjust the linear perfluoropolyether compound represented by the general formula (1) to a desired weight average molecular weight according to the purpose, the linear perfluoropolyether as described above is used in advance. The compound can be subjected to a hydrosilylation reaction with an organosilicon compound containing two SiH groups in the molecule under ordinary methods and conditions to extend the chain length. The product synthesized in this way can be used as the component (A).

  The component (A) of the present invention is contained in an amount of 30 to 90 parts by mass in the curable perfluoropolyether gel composition in order to obtain a pressure-sensitive adhesive sheet having solvent resistance, insulation failure resistance, heat resistance, airtightness, and elasticity. .

<(B) component>
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) acts as a crosslinking agent and a chain extender for the component (A). However, from the viewpoint of compatibility with the component (A) or the components (C) and (D) described later, dispersibility, uniformity after curing, etc., the component (B) is at least one per molecule. A monovalent perfluoroalkyl group, a monovalent perfluorooxyalkyl group, a monovalent perfluoropolyether group, a divalent perfluoroalkylene group, or a divalent perfluorooxyalkylene group. It is preferable to use what is.

  Examples of the component (B) include known organosilicon compounds described in, for example, Japanese Patent No. 2990646 or Japanese Patent Application Laid-Open No. 2000-248166, but are not particularly limited thereto.

（式中、Ｒｆ^３は一価のパーフルオロアルキル基又は一価のパーフルオロポリエーテル基、Ｒ^３は炭素数１〜２０の一価炭化水素基、Ｒ^４は炭素数２〜２０の二価炭化水素基であり、エーテル結合、アミド結合、カルボニル結合、又はエステル結合を含んでもよい二価の連結基である。ｋは２以上の整数であり、ｌは１〜６の整数であり、かつｋとｌの和が３〜１０となる整数である。） As the organosilicon compound of the component (B) of the present invention, those represented by the following general formula (8) are particularly useful.

(In the formula, Rf ³ is a monovalent perfluoroalkyl group or monovalent perfluoropolyether group, R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ⁴ is a divalent group having 2 to 20 carbon atoms. A divalent linking group which is a hydrocarbon group and may include an ether bond, an amide bond, a carbonyl bond, or an ester bond, k is an integer of 2 or more, l is an integer of 1 to 6, and (It is an integer in which the sum of k and l is 3 to 10.)

（式中、ｎは２〜２００、好ましくは２〜１００の整数である。） Examples of the monovalent perfluoroalkyl group or monovalent perfluoropolyether group of Rf ^{3 in} the general formula (8) include groups represented by the following general formula.
Monovalent perfluoroalkyl group:
C _b F _{2b + 1} −
(However, b is an integer of 1-20, preferably 2-10.)
Monovalent perfluoropolyether group:

(In the formula, n is an integer of 2 to 200, preferably 2 to 100.)

R ³ in the general formula (8) is a monovalent hydrocarbon group having 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group. , Isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group and other alkyl groups, cyclopentyl group, cyclohexyl group, cycloheptyl group and other cycloalkyl groups, vinyl group, allyl group, propenyl group, iso Examples include alkenyl groups such as propenyl group, butenyl group and hexenyl group, aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, aralkyl groups such as benzyl group, phenylethyl group and phenylpropyl group. Preferably has no aliphatic unsaturated bond.

R ⁴ in the general formula (8) is a divalent hydrocarbon group having 2 to 20 carbon atoms, and is a divalent linking group that may include an ether bond, an amide bond, a carbonyl bond, or an ester bond. . Examples of the linking group include an alkylene group, an arylene group, a combination thereof, or an ether bond oxygen atom (—O—), an amide bond (—NRCO—), a carbonyl bond (—CO—), an ester bond (— One or two or more of (COO-) may be interposed, and those having 2 to 12 carbon atoms are preferred, and the following groups are exemplified. Note that R in the —NRCO— group is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.
—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-
(However, Ph is a phenyl group.)
_{-CH 2 CH 2 CH 2 -N (} CH 3) -CO-
—CH ₂ CH ₂ CH ₂ —O—CO—

  The blending amount of the component (B) is a curing effective amount for curing the component (A) and the later-described component (D). As the curing effective amount, the hydrosilyl group (Si-H) of the component (B) is used with respect to 1 mol of the alkenyl group of the component (A) and the component (D) described later in the curable perfluoropolyether gel composition. ) Is preferably 0.2 to 2 mol, more preferably 0.5 to 1.5 mol. When the hydrosilyl group (Si—H) of the component (B) is 0.2 mol or more, the degree of crosslinking is sufficient, and a cured product can be obtained efficiently, which is preferable. Moreover, since 2 mol or less can suppress that it foams at the time of hardening, it is preferable.

<(C) component>
The hydrosilylation reaction catalyst of the component (C) of the present invention is a catalyst that promotes the addition reaction between the alkenyl group in the component (A) and the component (D) described later and the hydrosilyl group in the component (B). . 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. Moreover, as the hydrosilylation reaction catalyst of the component (C), a platinum group metal catalyst other than the platinum compound can also be used. As platinum group metal catalysts other than the platinum compounds, rhodium, ruthenium, iridium, and palladium compounds are known. 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.

  (C) The compounding quantity of the hydrosilylation reaction catalyst of a component is a catalyst amount. As the amount of the catalyst, it is preferably blended at a ratio of 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 (D).

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）
ｐは０又は１であり、Ｒｆ^１は下記一般式で表わされる基である。
Ｆ−［ＣＦ（ＣＦ_３）ＣＦ_２Ｏ］_ｗ−ＣＦ（ＣＦ_３）−
（式中、ｗは１〜５００の整数であり、好ましくは２〜２００の整数である。）］ <(D) component>
The component (D) of the present invention is a polyfluoromonoalkenyl compound having one alkenyl group in one molecule and having a perfluoropolyether structure in the main chain. In particular, a polyfluoromonoalkenyl compound of the following formula (2) is preferable.
Rf ^1- (X ′) _p —CH═CH ₂ (2)
[Wherein, X ′ represents —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ represents —CH ₂ — or the following structural formula (Z And R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group.).

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)
p is 0 or 1, and Rf ¹ is a group represented by the following general formula.
_{F- [CF (CF 3) CF} 2 O] w -CF (CF 3) -
(W is an integer of 1 to 500, preferably an integer of 2 to 200.)]

  Thus, if the component (D) is a polyfluoromonoalkenyl compound represented by the above general formula (2), the pressure-sensitive adhesive has better solvent resistance, insulation resistance, heat resistance, and airtightness. Since it becomes a sheet | seat, it is preferable.

（上記式において、ｍは１〜２００の整数、特に好ましくは２〜１００の整数である。） Specific examples of the polyfluoromonoalkenyl compound represented by the general formula (2) include the following.

(In the above formula, m is an integer of 1 to 200, particularly preferably an integer of 2 to 100.)

  The compounding amount of the polyfluoromonoalkenyl compound represented by the above formula (2) in the curable perfluoropolyether gel composition is 10 to 70 parts by mass (the total of the (A) component and the (D) component is 100 parts by mass). Amount).

［式（９）中、Ａは式：Ｃ_ｅＦ_２ｅ＋１−（ｅは１〜３の整数である）で表される基であり、ｄは１〜５００の整数である。］

（式（１０）中、Ａは上記と同じであり、ｆ及びｈはそれぞれ１〜３００の整数である。

（式（１１）中、Ａは上記と同じであり、ｉ及びｊはそれぞれ１〜３００の整数である。） <(E) component>
Furthermore, the component (E) of the present invention is a linear polyfluoro compound. Examples of the component (E) include the following general formulas (9) to (11).

[In Formula (9), A is a group represented by the formula: C _e F _{2e + 1-} (e is an integer of 1 to 3), and d is an integer of 1 to 500. ]

(In Formula (10), A is the same as the above, and f and h are integers of 1 to 300, respectively.

(In Formula (11), A is the same as the above, and i and j are each an integer of 1 to 300.)

  The blending amount of the component (E) is different in the curable perfluoropolyether gel composition, but the component (A) and the component (D) (total of linear perfluoropolyether compound and polyfluoromonoalkenyl compound) Amount) A ratio of 0 to 100 parts by mass with respect to 100 parts by mass. Therefore, the component (E) can be excluded. In the curable perfluoropolyether rubber composition, the component (E) is preferably in a proportion of 10 to 50 parts by mass with respect to 100 parts by mass of the component (A). (E) A component may be used individually by 1 type or in combination of 2 or more types.

[Adhesive layer]
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer made of the fluororesin gel on one or both sides of the support layer. The basic structure of the adhesive layer is very similar to a general elastomer, but the crosslink density is extremely low. Therefore, the adhesive layer is easily deformed by an external force, but is not fluid. The principle that the adhesive layer develops adhesiveness is that the fluororesin gel is deformed according to the fine irregularities of the adherend due to the pressure applied when the adhesive sheet is attached, and the contact area between the two increases.

  Moreover, since the gel-like adhesive used for the conventional adhesive sheet has low crosslink density, it absorbs an organic solvent etc. and is very easy to swell. However, the pressure-sensitive adhesive layer made of the fluororesin gel used in the present invention has a feature that unlike other gel-like pressure-sensitive adhesives, the fluororesin gel has a fluorine atom in the side chain and thus is hardly swollen by an organic solvent or the like. . To clarify this, among the silicone gels used as pressure-sensitive adhesives, the most solvent-resistant fluorosilicone gel (with the silicone side chain methyl group substituted by γ-trifluoropropyl group about 50%) and Even in comparison, the fluororesin gel having the above structure is a substance having a remarkably high solvent resistance even when a swelling test is carried out in a solvent such as toluene, and the numerical value of the swelling property is one digit lower.

  The adhesive layer is composed of the fluororesin gel having a three-dimensional network structure obtained by addition crosslinking of the curable perfluoropolyether gel composition, and conforms to JIS-K 2220 of the fluororesin gel. The penetration is preferably 30 to 200 °. Thus, when the adhesion layer is soft with a penetration of about 200 ° as measured by the storage consistency of the consistency test method (according to JISK2220), the adhesion of the adhesion layer to the adherend is good, When the hardness is about 30 °, the adhesive strength is high because the fluororesin gel itself has strength. If the penetration is 200 ° or less, it is possible to suppress the loss of the strength of the fluororesin gel itself, and even if it is once adhered to the adherend, a part of the adhesive layer is removed from the adherend. Since it can suppress that, it is preferable. Moreover, if it is 30 degrees or more, since it can suppress that the adhesiveness to a to-be-adhered body falls, it is preferable.

  The adhesive strength of the fluororesin gel constituting the adhesive layer to the glass is preferably in the range of 0.5 to 5 N / 25 mm in terms of adhesive strength when the peeling speed is 300 mm / min in a 180 degree peel test. In particular, 1 to 4 N / 25 mm is preferable from the viewpoint of reworkability and removability. If it is 0.5 N / 25 mm or more, the adhesive force is not too low, and it is preferable because peeling during use can be suppressed. If it is 5 N / 25 mm or less, it becomes easy to peel off when re-peeling is necessary, and workability is improved, which is preferable.

  As for the thickness of the said adhesion layer, about 1-500 micrometers is preferable, and 5-50 micrometers is especially preferable from the point of the adhesive force to a to-be-adhered body. A thickness of 1 μm or more is preferable because the thickness is not too thin, processing is easy, and sufficient adhesive strength can be obtained. Moreover, if it is 500 micrometers or less, since the tear strength of a fluororesin gel is not too low and it becomes difficult to destroy a fluororesin gel, it is preferable.

[Support layer]
The pressure-sensitive adhesive sheet of the present invention has a support layer. The support layer is preferably a resin film containing fluorine. The support layer is made of, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer (ETFE), ethylene trifluoride chloride (PCTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). ), Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), regenerated cellulose film, diacetate cellulose film, triacetate cellulose film, tetraacetyl cellulose Film, polyethylene film, polypropylene film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polyethylene terephthalate film, polycarbonate film, polyethylene naphtha Film, polyethersulfone film, polyetheretherketone film, polysulfone film, polyetherimide film, polyimide film, polyarylate film, cycloolefin polymer film, norbornene resin film, polystyrene film, hydrochloric acid rubber film, nylon film, poly A film made of an acrylate film or the like may be used.

  However, fluororubber having elasticity and solvent resistance is particularly preferable as the support layer.

  As described above, if the support layer is made of fluororubber, the pressure-sensitive adhesive sheet has solvent resistance, insulation failure resistance, heat resistance, and airtightness, and more excellent elasticity and solvent resistance. Therefore, it is preferable.

As the fluororubber constituting the support layer, at least,
(A) having at least two alkenyl groups in one molecule and -C _a F _2a O- in the main chain
(In the formula, a is an integer of 1 to 6.)
A linear perfluoropolyether compound having a number average molecular weight of 3,000 to 100,000 having a perfluoropolyether structure containing a repeating unit represented by: 100 parts by mass,
(B) a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: the molar ratio of SiH groups in component (b) to alkenyl groups in component (a) is 0.4 to An amount of 5.0,
(C) hydrosilylation reaction catalyst: catalyst amount, and (d) silica-based filler: 1 to 100 parts by mass,
It is preferable that it is a fluororubber obtained by addition-crosslinking the fluorine-containing curable composition containing this.

  Thus, if the fluororubber is obtained by addition-crosslinking a fluorine-containing curable composition containing at least a predetermined amount of the above components (a) to (d), more solvent resistance and insulation resistance Since it becomes an adhesive sheet which has a support layer excellent in property, heat resistance, airtightness, and rubber elasticity, it is preferable.

<(A) component>
The component (a) has at least two alkenyl groups in one molecule, and —C _a F _2a O— in the main chain.
(In the formula, a is an integer of 1 to 6.)
A linear perfluoropolyether compound having a number average molecular weight of 3,000 to 100,000 having a perfluoropolyether structure containing a repeating unit represented by:

（式中、ａは１〜６の整数であり、ｑは２０〜６００の整数である。ｑは、好ましくは３０〜４００、より好ましくは３０〜２００の整数である。） Here, as a perfluoropolyether structure of the said (a) component, what is shown, for example by following General formula (3) is preferable.

(In the formula, a is an integer of 1 to 6 and q is an integer of 20 to 600. q is preferably an integer of 30 to 400, more preferably 30 to 200.)

  Thus, if the component (a) is a linear perfluoropolyether compound having a perfluoropolyether structure represented by the general formula (3), solvent resistance, insulation resistance, heat resistance It is preferable because the pressure-sensitive adhesive sheet has a support layer that is less swelled with various organic solvents, in addition to its property, airtightness, and elasticity.

Examples of the repeating unit represented by the above formula —C _a F _2a O— include the following units. In addition, the perfluoropolyether structure of the component (a) may be composed of one kind of the following repeating unit or the like, or may be a combination of two or more kinds.
—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-
Of these, the following units are particularly preferred.
—CF ₂ O—
-CF ₂ CF ₂ O-
-CF ₂ CF ₂ CF ₂ O-
-CF (CF ₃ ) CF ₂ O-

The linear perfluoropolyether compound as component (a) has at least two alkenyl groups in one molecule. As the alkenyl group, those having 2 to 8 carbon atoms, particularly 2 to 6 carbon atoms and having a CH ₂ ═CH— structure at the terminal are preferable. For example, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group , A group having a CH ₂ ═CH— structure at the end, such as a hexenyl group, particularly a vinyl group, an allyl group, and the like are preferable.

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）
Ｒｆ^１は二価のパーフルオロポリエーテル構造であり、上記式（３）、即ち−（Ｃ_ａＦ_２ａＯ）_ｑ−で示される繰り返し単位を含むものが好ましい。Ｑは炭素数１〜１５の二価の炭化水素基であり、エーテル結合を含んでいてもよく、具体的にはアルキレン基、エーテル結合を含んでいてもよいアルキレン基である。ｐは独立に０又は１である。］ Examples of the component (a) include compounds represented by the following general formula (12) or (13).
_{CH 2 = CH- (X) p} -Rf 1 - (X ') p -CH = CH 2 (12)
_{CH 2 = CH- (X) p} -Q-Rf 1 -Q- (X ') p -CH = CH 2 (13)
[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group.

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)
Rf ¹ is a divalent perfluoropolyether structure, and preferably contains a repeating unit represented by the above formula (3), that is, — (C _a F _2a O) _q —. Q is a C1-C15 divalent hydrocarbon group which may contain an ether bond, specifically an alkylene group or an alkylene group which may contain an ether bond. p is independently 0 or 1. ]

［式中、Ｘは−ＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＨ_２ＯＣＨ_２−、及び−Ｙ−ＮＲ^１−ＣＯ−（但し、Ｙは−ＣＨ_２−又は下記構造式（Ｚ）で示される基であり、Ｒ^１は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかである。Ｘ’は−ＣＨ_２−、−ＯＣＨ_２−、−ＣＨ_２ＯＣＨ_２−、及び−ＣＯ−ＮＲ^２−Ｙ’−（但し、Ｙ’は−ＣＨ_２−又は下記構造式（Ｚ’）で示される基であり、Ｒ^２は水素原子、メチル基、フェニル基、及びアリル基のいずれかである。）のいずれかである。ｐは独立に０又は１であり、ｒは２〜６の整数であり、ｍ、ｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が２０〜６００となる整数である。］

（上記構造式（Ｚ）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。）

（上記構造式（Ｚ’）はｏ，ｍ又はｐ位で示されるジメチルフェニルシリレン基である。） As such a linear perfluoropolyether compound of the component (a), a compound represented by the following general formula (4) is particularly preferable.

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 20 to 600. ]

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)

  Thus, when the component (a) is a linear perfluoropolyether compound represented by the general formula (4), solvent resistance, insulation resistance, heat resistance, airtightness, and elasticity In addition, the pressure-sensitive adhesive sheet having a support layer with less swelling with respect to various organic solvents is preferable.

  The linear perfluoropolyether compound of the above formula (4) has a number average molecular weight of 3,000 to 100,000, particularly 3,000 to 30,000, as determined by gel permeation chromatography (GPC). Is desirable. A number average molecular weight of 3,000 or more is preferable because the required chemical resistance can be satisfied, and a number average molecular weight of 100,000 or less is preferable because of compatibility with other components.

Specific examples of the linear perfluoropolyether compound represented by the general formula (4) include those represented by the following formula.

（式中、ｍ及びｎはそれぞれ０〜６００の整数であり、かつｍとｎの和が２０〜６００を満足する整数を示す。）

(In the formula, m and n are each an integer of 0 to 600, and the sum of m and n represents an integer satisfying 20 to 600.)

  Furthermore, in the present invention, in order to adjust the linear perfluoropolyether compound represented by the above formula (4) to a desired number average molecular weight according to the purpose, a linear perfluoropolyether compound as described above is used in advance. The chain length can be extended by a hydrosilylation reaction with an organosilicon compound containing two SiH groups in the molecule under ordinary methods and conditions. The product synthesized in this way can also be used as component (a). These linear fluoropolyether compounds can be used singly or in combination of two or more. The amount of component (a) is 100 parts by mass.

<(B) component>
The component (b) is a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule. The component (b) acts as a crosslinking agent and chain extender for the component (a). In consideration of compatibility with the component (a), dispersibility, and uniformity after curing, the component (b) contains at least one monovalent perfluoro group or monovalent perfluoro in at least one molecule. It preferably has any one of an oxy group, a divalent perfluoro group, and a divalent perfluorooxy group. Moreover, it is preferable that it is a fluorine-containing organosilicon compound which has 3 or more of hydrogen atoms couple | bonded with the silicon atom in 1 molecule.

（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、かつｉとｊの和が２〜２００、好ましくは２〜１００を満たす整数である。）
−（ＣＦ_２Ｏ）_ｃ−（ＣＦ_２ＣＦ_２Ｏ）_ｄ−ＣＦ_２−
（但し、ｃ及びｄはそれぞれ１〜５０の整数である。） Examples of the monovalent or divalent perfluoro group and perfluorooxy group include groups 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 sum of i and j is an integer satisfying 2 to 200, preferably 2 to 100.)
_{- (CF 2 O) c -} (CF 2 CF 2 O) d -CF 2 -
(However, c and d are each an integer of 1 to 50.)

Further, these monovalent or divalent perfluoroalkyl groups and perfluorooxy groups may be directly bonded to the silicon atom, but may be bonded to the silicon atom via a divalent linking group. . Here, the divalent linking group may be an alkylene group, an arylene group, or a combination thereof, or an ether bond oxygen atom, an amide bond, a carbonyl bond, or the like interposed therebetween. The thing of number 2-12 is preferable and the following group etc. are mentioned.
—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—

  Examples of the monovalent substituent bonded to the silicon atom other than the monovalent or divalent perfluoroalkyl group and perfluorooxy group (fluorine-containing substituent) in the organosilicon compound of component (b) include: Alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, octyl and decyl; aryl groups such as phenyl, tolyl and naphthyl; aralkyl such as benzyl and phenylethyl Group: or an unsubstituted or substituted hydrocarbon group having 1 to 20 carbon atoms such as a chloromethyl group, a chloropropyl group, a cyanoethyl group or the like in which a part of hydrogen atoms of these groups is substituted with a chlorine atom, a cyano group, or the like Can be mentioned.

  The fluorine-containing organosilicon compound as the component (b) may be cyclic or chain-like, and further may be a three-dimensional network. Further, the number of silicon atoms in the molecule in the fluorine-containing organosilicon compound is not particularly limited, but usually 2 to 60, particularly about 3 to 30 is preferable.

  Examples of such a fluorine-containing organosilicon compound as component (b) 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.

（式中、ｎ、ｍは、ｎ＝１〜５０、ｍ＝１〜５０、かつｎ＋ｍ＝２〜５０を満たす整数である。）

(In the formula, n and m are integers satisfying n = 1 to 50, m = 1 to 50, and n + m = 2 to 50.)

（式中、ｎ、ｍは、ｎ＝１〜５０、ｍ＝１〜５０、かつｎ＋ｍ＝２〜５０を満たす整数である。）

(In the formula, n and m are integers satisfying n = 1 to 50, m = 1 to 50, and n + m = 2 to 50.)

（式中、ｎ、ｍは、ｎ＝１〜５０、ｍ＝１〜５０、かつｎ＋ｍ＝２〜５０を満たす整数である。）

(In the formula, n and m are integers satisfying n = 1 to 50, m = 1 to 50, and n + m = 2 to 50.)

  The blending amount of the component (b) is usually a hydrosilyl group in the component (b), that is, SiH with respect to 1 mol of an alkenyl group such as vinyl group, allyl group, cycloalkenyl group and the like contained in the component (a). The amount is such that the group is 0.4 to 5.0 moles. The blending amount of the component (b) is more preferably 0.8 to 3.0 mol. If the amount of component (b) is such that the amount of SiH groups in component (b) is 0.4 mol or more relative to 1 mol of alkenyl groups contained in component (a), it is obtained by addition crosslinking. The degree of crosslinking of the obtained fluororubber is sufficient and the strength of the cured product is sufficient, which is preferable. If the amount of the component (b) is such that the SiH group of the component (b) is 5.0 mol or less with respect to 1 mol of the alkenyl group contained in the component (a), the component (b) This is preferable because a decrease in strength of the cured product due to an excessive component can be suppressed. Moreover, this (b) component may be used individually by 1 type, and may use 2 or more types together.

<(C) component>
The component (c) is a hydrosilylation reaction catalyst. As the hydrosilylation reaction catalyst, transition metals, for example, platinum group metals such as Pt, Rh, Pd, and compounds of these transition metals are preferably used. In the present invention, since these compounds are generally precious metal compounds and are expensive, platinum compounds that are relatively easily available are preferably used. Specific 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 vinylsiloxane, platinum / silica, alumina, or carbon. It is not limited.

As platinum group metal compounds other than platinum compounds, rhodium, ruthenium, iridium, palladium compounds and the like are known. For example, RhCl (PPh ₃ ) ₃ , RhCl (CO) (PPh ₃ ) ₂ , RhC1 (C ₂ H ₄ ) ₂ , Ru ₃ (CO) ₁₂ , IrCl (CO) (PPh ₃ ) ₂ , Pd (PPh ₃ ) ₄ (Ph represents a phenyl group). The amount of these catalysts used is not particularly limited as long as it is a catalyst amount. Although a desired curing rate can be obtained with a normal amount of catalyst, the amount of the catalyst is 0.1 to 1,000 ppm (platinum group) with respect to the total amount of the composition in order to obtain an economical viewpoint or a good cured product. Metal conversion), more preferably in the range of about 0.1 to 500 ppm (same as above).

<(D) component>
The component (d) is a silica-based filler. Examples of the silica-based filler include pulverized silica obtained by pulverizing quartz and glass, fused silica that is once melted and then formed into spherical particles, wet silica produced by adding a mineral acid to sodium silicate, and silane compounds. From the viewpoint of improving mechanical strength, a silica-based filler having a BET specific surface area of 30 m ² / g or more is preferable, and wet silica and dry silica correspond to this, Dry silica with low adsorbed moisture is preferred. Furthermore, when the wettability with the polymer component is taken into consideration, it is preferable that the surface of the silica-based filler is hydrophobized. It is preferable that the surface of the silica-based filler be hydrophobized because sufficient mechanical strength can be obtained and adverse effects such as abnormally high viscosity of the fluorinated curable composition can be suppressed. In particular, the component (d) is preferably a silica-based filler whose surface is hydrophobized with a BET specific surface area of 30 m ² / g or more.

  The compounding amount of the component (d) is 1 to 100 parts by mass with respect to 100 parts by mass of the component (a). If it is 1 part by mass or more, the reinforcing effect of the silica-based filler of component (d) is sufficiently obtained, and if it is 100 parts by mass or less, the viscosity of the fluorinated curable composition does not become too high, and the work It is preferable because of its good properties.

  In the case of a pressure-sensitive adhesive sheet for temporary fixing or use that requires elongation, it is necessary to impart rubber-like elasticity to the pressure-sensitive adhesive sheet. In that case, it is necessary to have a support layer having rubber elasticity that is stronger than the adhesive layer.

  It is preferable that the rubber hardness of the fluororubber of the support layer is in a range of 10 to 80 in durometer type A conforming to JIS K 6253 [durometer A]. If the hardness is 10 or more, it is preferable because the strength is sufficient, and if it is 80 or less, it becomes an adhesive sheet having good flexibility and elasticity, and is particularly preferable because it becomes an adhesive sheet suitable for temporary fixing or the like.

  The thickness of the support layer is preferably 10 to 2,000 μm, more preferably 30 to 500 μm from the viewpoint of followability to the adherend. If it is 10 μm or more, it is preferable because it is easy to impart rubber elasticity, and if it is 500 μm or less, it is not too heavy and the workability is good, which is also preferable in terms of cost.

[Optional ingredients]
In addition to the above-described components, both the adhesive layer and the support layer have various additives depending on the purpose in order to impart conductivity, thermal conductivity, antistatic properties, heat resistance, etc., such as titanium oxide and iron oxide. Inorganic fillers such as cerium oxide, vanadium oxide, cobalt oxide, chromium oxide, manganese oxide and other metal oxides and their composites, quartz powder, diatomaceous earth, calcium carbonate, magnesium carbonate, alumina, carbon, etc. can be added In addition, pigments, heat-resistant agents, flame retardants, plasticizers, reaction control agents, and the like may be added as long as the intended properties are not impaired. In addition, the addition amount of these arbitrary components can be made into a normal amount in the range which does not inhibit the effect of this invention.

[Method for producing adhesive sheet]
Next, the specific example of the manufacturing method of the adhesive sheet of this invention is demonstrated. The method for producing the pressure-sensitive adhesive sheet of the present invention is not limited to this. Examples of the molding method include injection molding, compression molding, injection molding, extrusion molding, transfer molding and the like when molding. When performing sheeting, calendar molding, extrusion molding, coating molding, and the like can be given. In the case of coating, it can be prepared by applying on a support by a bar coater, blade coater, spin coater, roll coater, gravure coater, flow coater, die coater, spray, screen printing or the like and drying. In the case of processing into a flat shape, it is preferable to form a sheet by calendering and then punch it into a required size. If thin film properties are required, the coating method should be selected. In order to obtain a required shape in accordance with other situations, it is possible to perform molding by selecting from the above molding methods.

<Preparation of support layer>
First, unvulcanized fluororubber is heat-molded to a predetermined thickness to obtain a support layer sheet. A surface treatment is appropriately applied to the surface of the support layer sheet having a desired shape and size. Preferably, in order to increase the contact area with the pressure-sensitive adhesive layer, a blast treatment is preferably performed. When the support layer is flat like a mirror surface, the contact area of the adhesive layer with the adherend is larger than the contact area with the support layer. As a result, when an adhesive sheet is stuck on an adherend and then peeled off, the possibility that the adhesive layer and the support layer will peel increases.

<Preparation of adhesive layer>
Next, after applying an uncrosslinked fluororesin gel having fluidity on one side of the sheet of the support layer under normal temperature conditions, the gel is formed by heating. Thus, after apply | coating a fluororesin to a support layer, the contact area of an adhesion layer and a support layer can be increased by making it gelatinize. After gelation, a plastic film such as polyester coated with a release agent made of silicone or the like is pasted on the adhesive layer. When the adhesive layer is required on both surfaces of the support layer sheet, the other surface of the support layer is coated with a fluororesin under the same conditions as described above to be gelled. After gelation, a double-sided PSA sheet with a three-layer structure can be obtained by sticking a plastic film in the same manner as described above.

  As described above, according to the present invention, it has solvent resistance that does not decrease the adhesive strength even when it comes into contact with an organic solvent, and does not cause an insulation failure even when used in the vicinity of a contact portion where the electrical connection state repeats ON / OFF. It is possible to provide a pressure-sensitive adhesive sheet that has resistance to insulation, has heat resistance that does not decrease deformation and adhesiveness even when used in the vicinity of a heat-applied part, has good airtightness, and has rubber elasticity. it can. In particular, the pressure-sensitive adhesive sheet having these characteristics fixes various machines, electrical / electronic parts, plastic molded articles, etc., temporarily fixes various parts at the time of manufacture and inspection, building materials, signs, It can be suitably used as a masking material when a paint is placed on a transportation machine or the like.

  Hereinafter, although an example and a comparative example of an adhesive sheet of the present invention are given and the present invention is explained still in detail, the present invention is not limited to these.

で表されるポリマー（（ａ）成分に相当、粘度５，５００ｍｍ^２／ｓ、数平均分子量１５，７００、ビニル基量０．０１２モル／１００ｇ）１００質量部、比表面積３００ｍ^２／ｇの乾式シリカ系充填材の表面をヘキサメチルジシラザンで処理したシリカ系充填材（（ｄ）成分に相当）５０質量部をニーダー中で１７５℃／２時間混合した。その後、プラネタリーミキサーでシリカ系充填材の配合量が１６．７質量部になるように、式（１４）のポリマー２００質量部添加して調製し、３本ロールミル処理を施した。以上調製した組成物１１６．７質量部に、下記式（１５）で表される含フッ素有機ケイ素化合物（（ｂ）成分に相当）２．９質量部、

塩化白金酸をＣＨ_２＝ＣＨＳｉＭｅ_２ＯＳｉＭｅ_２ＣＨ＝ＣＨ_２で変性した触媒のトルエン溶液（（ｃ）成分に相当、白金濃度０．５質量％）０．２質量部及びエチニルシクロヘキサノールの５０％トルエン溶液０．３質量部を加え、プラネタリーミキサーで混合し、含フッ素硬化性組成物を得た。この含フッ素硬化性組成物を１５０℃、１０分のプレス架橋（一次架橋）を行って硬化シート（１７０ｍｍ×１３０ｍｍ×０．１ｍｍ及び１３０ｍｍ×１３０ｍｍ×２ｍｍ）状の支持層を形成した。 [Example 1]
<Preparation of support layer>
The support layer has the following formula (14)

100 parts by weight of a polymer represented by the formula (equivalent to component (a), viscosity 5,500 mm ² / s, number average molecular weight 15,700, vinyl group content 0.012 mol / 100 g), specific surface area 300 m ² / g 50 parts by mass of a silica filler (corresponding to the component (d)) whose surface was treated with hexamethyldisilazane was mixed in a kneader at 175 ° C./2 hours. Then, 200 mass parts of polymers of Formula (14) were added and prepared so that the compounding quantity of a silica type filler might be 16.7 mass parts with a planetary mixer, and the 3 roll mill process was performed. 116.7 parts by mass of the composition prepared above, 2.9 parts by mass of a fluorine-containing organosilicon compound represented by the following formula (15) (corresponding to the component (b)),

0.2 parts by mass of a toluene solution of a catalyst obtained by modifying chloroplatinic acid with CH ₂ ═CHSiMe ₂ OSiMe ₂ CH═CH ₂ (corresponding to component (c), platinum concentration of 0.5% by mass) and 50% of ethynylcyclohexanol 0.3 parts by mass of a toluene solution was added and mixed with a planetary mixer to obtain a fluorine-containing curable composition. This fluorine-containing curable composition was subjected to press crosslinking (primary crosslinking) at 150 ° C. for 10 minutes to form a support layer in the form of a cured sheet (170 mm × 130 mm × 0.1 mm and 130 mm × 130 mm × 2 mm).

  The physical properties of the obtained 2 mm thick cured sheet-like support layer were measured according to JIS K6253 and JIS K6251. Hardness (durometer type A) = 40, tensile strength = 8.3 MPa, elongation at break = 410%.

<Preparation of adhesive layer>
Next, the fluororesin gel used for the adhesive layer contains 72.5 parts by mass of a polymer represented by the following formula (16) (corresponding to the component (A)) and a polymer represented by the following formula (17) (component (D) Equivalent to 27.5 parts by mass of viscosity 1000 cSt), 33 parts by mass of the polymer represented by the formula (18) (corresponding to the component (E)), 0.15 parts by mass of a 50% toluene solution of ethynylcyclohexanol, Ethanol solution of vinylsiloxane complex (corresponding to component (C), platinum metal concentration 3.0% by mass) 0.015 part by mass, compound represented by the following formula (19) (corresponding to component (B)) 26.5 mass Part was added and mixed to prepare a curable perfluoropolyether gel composition (I). When the prepared curable perfluoropolyether gel composition (I) was cured to form a fluororesin gel, the needle penetration was 70 °.

  The prepared curable perfluoropolyether gel composition (I) is printed on the above support layer (0.1 mm thick sheet) to a thickness of 0.02 mm, and then gelled at 150 ° C. for 1 hour. Thus, an adhesive layer was formed on one side of the support layer. After gelation, a polyester film coated with a silicone release agent was stuck on the adhesive layer. The film was peeled off when the following evaluation was performed. The result of each evaluation item of the adhesive sheet is shown in Table 1.

[Example 2]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the support layer was the same as in Example 1 and the fluororesin gel of the pressure-sensitive adhesive layer was prepared from the following curable perfluoropolyether gel composition (II). The result of each evaluation item of the adhesive sheet is shown in Table 1.

  In Example 2, 84.0 parts by mass of the polymer represented by the above formula (16) (corresponding to the component (A)) and the polymer represented by the above formula (17) (corresponding to the component (D), viscosity 1000 cSt). 0 parts by mass, 33 parts by mass of the polymer represented by the formula (18) (corresponding to the component (E)), 22.6 parts by mass of the compound represented by the formula (19) (corresponding to the component (B)), and other components The same amount as in Example 1 was added and mixed to prepare a curable perfluoropolyether gel composition (II). When the prepared curable perfluoropolyether gel composition (II) was cured, the needle penetration was 35 °.

[Example 3]
A laminated adhesive sheet was prepared in the same manner as in Example 1 except that the support layer was the same as in Example 1 and the fluororesin gel of the adhesive layer was prepared from the following curable perfluoropolyether gel composition (III). Table 1 shows the results of the evaluation items of the laminated adhesive sheet.

  In Example 3, 69.6 parts by mass of the polymer represented by the formula (16) (corresponding to the component (A)) and the polymer represented by the formula (17) (corresponding to the component (D), viscosity 1000 cSt) 30. 4 parts by mass, 33 parts by mass of the polymer represented by the formula (18) (corresponding to the component (E)), 26.0 parts by mass of the compound represented by the formula (19) (corresponding to the component (B)), and other components The same amount as in Example 1 was added and mixed to prepare a curable perfluoropolyether gel composition (III). The degree of needle penetration when the prepared curable perfluoropolyether gel composition (III) was cured was 100 °.

[Comparative Example 1]
Uncured dimethyl silicone type millable rubber (KE941 manufactured by Shin-Etsu Chemical Co., Ltd.) with a hardness of 40 degrees (type A) is dispensed to a thickness of 0.1 mm, and primary vulcanization is supported at 170 ° C. for 10 minutes. A layer was formed. Next, a dimethyl silicone gel having a penetration of 80 ° (KE1051 manufactured by Shin-Etsu Chemical Co., Ltd.) was printed on the support layer to a thickness of 0.02 mm, and then the gel was subjected to conditions of 150 ° C. and 1 hour. The pressure-sensitive adhesive sheet was prepared by forming a pressure-sensitive adhesive layer. After gelation, a polyester film coated with a silicone release agent was stuck on the adhesive layer. The film was peeled off when the following evaluation was performed. The evaluation results are shown in Table 1.

[Comparative Example 2]
Resin composition mainly composed of a copolymer of methacrylic acid alkyl ester (n-butyl acrylate / acrylic acid / 2-hydroxymethyl acrylate = 95/4/1) and isocyanate compound (13HS8515 manufactured by Toyo Ink) Was formed on PET having a thickness of 0.1 mm to a thickness of 0.1 mm to prepare an adhesive sheet. The evaluation results are shown in Table 1.

<Evaluation items>
Adhesive layer adhesive strength measurement The adhesive sheets prepared in Examples and Comparative Examples were cut to a width of 25 mm and a length of 10 cm, and the adhesive layer side was pasted on a 4 mm thick glass substrate, and 0.3 m at room temperature. The glass substrate and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet were peeled off at 180 ° peel at a rate of / min and the pressure-sensitive adhesive force was measured.

-Solvent resistance The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were immersed in a solvent, and the reduction rate (%) of the adhesive strength after 1 hr was measured in the same manner as described above.

-Swelling property The adhesive sheet produced in the Example and the comparative example was immersed in the solvent in toluene, and the volume expansion change rate (%) was measured.

-Long-term sticking stability The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were cut to a width of 25 mm and a length of 10 cm, and the pressure-sensitive adhesive layer side was stuck on a 4 mm-thick glass substrate, and the room temperature was 50% RH. After being stored for 1 month, the glass substrate and the adhesive layer were peeled at 180 ° peel at room temperature, the adhesive force was measured, and the rate of change (%) was measured.

・ Removability The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were cut to a width of 25 mm and a length of 10 cm, and the pressure-sensitive adhesive layer side was pasted on a 4 mm-thick glass substrate, and the humidity was 1 at room temperature of 50% RH. After storage for months, the glass substrate and the adhesive layer were peeled off at 180 ° peel at room temperature, and it was confirmed whether or not the adhesive component had transferred to the glass surface. The thing which does not transfer is set to (circle) and the thing to which an adhesion component transfers is set to x.

-Airtightness The gas permeability of oxygen at 25 ° C of the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples was measured with a gas permeability measuring device (K-315N-02) manufactured by Rika Seiki Kogyo Co., Ltd. The numerical value shows each value when natural rubber is 100.

-Elasticity with respect to deformation When the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were bent at 180 degrees, the presence or absence of damage to the pressure-sensitive adhesive sheets was confirmed. The thing without a change was set to (circle) and the thing with a crack deformation was set to x.

-Adhesiveness after heat resistance The adhesive sheets prepared in Examples and Comparative Examples were cut to a width of 25 mm and a length of 10 cm, the adhesive layer side was attached on a 4 mm thick glass substrate, and aged at 180 ° C for 100 hours. Then, after the sheet reached room temperature, the glass substrate and the adhesive layer were peeled off at 180 ° peel, and the adhesive force was measured to confirm the state of change, the transition of components, and the state of the adhesive layer.

-Insulation failure resistance The adhesive sheets prepared in the examples and comparative examples were cut to a width of 25 mm and a length of 10 cm, the adhesive layer side was pasted on the coil, and stored for one month at a room temperature of 50% RH, then conducting. Evaluated whether it was possible to detect insulation failure. If the insulation failure was caused, it was evaluated as x.

-Detection of the amount of siloxane contained in the pressure-sensitive adhesive sheet Further, in Comparative Example 1 in which silicone rubber was used for the support layer and silicone gel was used for the pressure-sensitive adhesive layer, the amount of low molecular siloxane up to D20 was detected at 100 ppm or more. In comparison with this, in the pressure-sensitive adhesive sheets according to Examples 1 to 3, the amount of low-molecular siloxane was detected only to 0.01 ppm or less. This revealed that the pressure-sensitive adhesive sheets according to Examples 1 to 3 contained almost no low molecular siloxane and no silicone oil.

  As shown above, Comparative Examples 1 and 2 have poor solvent resistance, swelling property, long-term sticking stability, removability, airtightness, deformation elasticity, adhesiveness after heat resistance, and insulation resistance. It became clear. On the other hand, according to the pressure-sensitive adhesive sheet of the present invention, not only has excellent adhesive strength, but also solvent resistance, swelling property, long-term sticking stability, removability, airtightness, deformation elasticity, post-heat-resistant adhesiveness, and resistance. It was clarified that the pressure-sensitive adhesive sheet was excellent in insulation failure.

  That is, according to the present invention, it has solvent resistance that does not decrease the adhesive strength even when it comes into contact with an organic solvent, and does not cause an insulation failure even if it is used in the vicinity of a contact portion where the electrical connection state repeats ON / OFF repeatedly. It is possible to provide a pressure-sensitive adhesive sheet that has insulation barrier properties, has heat resistance that does not decrease deformation and adhesiveness even when used in the vicinity of heat-affected portions, has good airtightness, and has rubber elasticity. It has been shown. In particular, the pressure-sensitive adhesive sheet having these characteristics fixes various machines, electrical / electronic parts, plastic molded articles, etc., temporarily fixes various parts at the time of manufacture and inspection, building materials, signs, It can be suitably used as a masking material when a paint is placed on a transportation machine or the like.

DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet, 2 ... Adhesive layer, 3 ... Support layer

Claims (12)

A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer made of a fluororesin gel on one or both sides of the support layer, wherein the fluororesin gel is at least
(A) Linear perfluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain: 30 to 90 parts by mass
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: effective amount of curing;
(C) Hydrosilylation reaction catalyst: catalyst amount,
(D) Polyfluoromonoalkenyl compound having one alkenyl group in one molecule and a perfluoropolyether structure in the main chain: 10 to 70 parts by mass (total of components (A) and (D) Is an amount of 100 parts by mass), and (E) a linear polyfluoro compound: a pressure-sensitive adhesive sheet comprising a curable perfluoropolyether gel composition containing 0 to 100 parts by mass. The pressure-sensitive adhesive sheet according to claim 1, wherein the component (A) is a linear perfluoropolyether compound represented by the following general formula (1).

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group). p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 50 to 600.

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)] The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the component (D) is a polyfluoromonoalkenyl compound represented by the following general formula (2).
Rf ^1- (X ′) _p —CH═CH ₂ (2)
[Wherein, X ′ represents —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ represents —CH ₂ — or the following structural formula (Z And R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group.).

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)
p is 0 or 1, and Rf ¹ is a group represented by the following general formula.
_{F- [CF (CF 3) CF} 2 O] w -CF (CF 3) -
(Wherein w is an integer of 1 to 500)]   The adhesive layer is made of the fluororesin gel having a three-dimensional network structure obtained by addition crosslinking of the curable perfluoropolyether gel composition, and conforms to JIS-K 2220 of the fluororesin gel. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the penetration is 30 to 200 °.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the support layer is made of fluororubber. The fluororubber is at least
(A) having at least two alkenyl groups in one molecule and -C _a F _2a O- in the main chain
(In the formula, a is an integer of 1 to 6.)
A linear perfluoropolyether compound having a number average molecular weight of 3,000 to 100,000 having a perfluoropolyether structure containing a repeating unit represented by: 100 parts by mass,
(B) a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule: the molar ratio of SiH groups in component (b) to alkenyl groups in component (a) is 0.4 to An amount of 5.0,
(C) hydrosilylation reaction catalyst: catalyst amount, and (d) silica-based filler: 1 to 100 parts by mass,
The pressure-sensitive adhesive sheet according to claim 5, wherein the pressure-sensitive adhesive sheet is obtained by addition crosslinking of a fluorine-containing curable composition containing The pressure-sensitive adhesive sheet according to claim 6, wherein the component (a) is a linear perfluoropolyether compound having a perfluoropolyether structure represented by the following general formula (3).

(In the formula, a is an integer of 1 to 6, and q is an integer of 20 to 600.) The pressure-sensitive adhesive sheet according to claim 6 or 7, wherein the component (a) is a linear perfluoropolyether compound represented by the following general formula (4).

[Wherein, X is _{-CH 2 -, - CH 2 O} -, - CH 2 OCH 2 -, and ^-Y-NR 1 -CO- (where, Y is -CH ₂ - or in the following structural formula (Z) And R ¹ is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. X ′ is —CH ₂ —, —OCH ₂ —, —CH ₂ OCH ₂ —, and —CO—NR ² —Y′— (where Y ′ is represented by —CH ₂ — or the following structural formula (Z ′)). R ² is any one of a hydrogen atom, a methyl group, a phenyl group, and an allyl group. p is independently 0 or 1, r is an integer of 2 to 6, m and n are each an integer of 0 to 600, and the sum of m and n is an integer of 20 to 600. ]

(The structural formula (Z) is a dimethylphenylsilylene group shown at the o, m, or p position.)

(The structural formula (Z ′) is a dimethylphenylsilylene group shown at the o, m, or p position.)   The component (b) is any one of at least one monovalent perfluoro group, monovalent perfluorooxy group, divalent perfluoro group, and divalent perfluorooxy group in at least one molecule. The pressure-sensitive adhesive sheet according to any one of claims 6 to 8, which is a fluorine-containing organosilicon compound having at least two hydrogen atoms bonded to silicon atoms. The pressure-sensitive adhesive according to any one of claims 6 to 9, wherein the component (d) is a silica-based filler having a BET specific surface area of 30 m ² / g or more and having a hydrophobic surface. Sheet.   11. The pressure-sensitive adhesive according to claim 5, wherein a rubber hardness of the fluororubber is in a range of 10 to 80 in a durometer type A conforming to JIS K 6253 [durometer A]. Sheet.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 11, wherein the adhesive strength of the fluororesin gel to glass is in a range of 0.5 to 5 N / 25 mm.

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