JP2022123331A - Adhesive silicone gel sheet and article - Google Patents

Abstract

To provide a single-sided or double-sided silicone gel sheet that is high in surface adhesiveness, at the same time, is difficult to peel after adhesion and can be peeled without disrupting during peeling and an article using the sheet.SOLUTION: A single-sided or double-sided silicone gel sheet formed by laminating an adhesive silicone gel layer that comprises (A) a straight-chain organopolysiloxane having one silicon-bonded vinyl group at each end of a molecular chain; (B) a three-dimensional network-structure organohydrogen polysiloxane containing diorganohydrogen siloxy units and SiO4/2 units; (C) linear or branched methylhydrogen polysiloxane having SiH groups only at the ends of the molecular chains, and (D) a cured material of a curable silicone gel composition that contains an additive reaction catalyst and does not contain a filler, in which the SiH group molar ratio of components (B) and (C) is within a specific range, and the penetration of the silicone gel cured material is 30 to 80.SELECTED DRAWING: Figure 2

Description

The present invention relates to an adhesive silicone gel sheet having an adhesive silicone gel layer obtained by curing a curable silicone gel composition composed of certain specific ingredients, and in particular, the adhesive silicone gel layer has surface adhesiveness. Since the adhesive silicone gel sheet is difficult to peel off after being applied, it can be peeled off without destroying the adhesive silicone gel layer. It is.

The curable silicone gel composition comprises an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms (i.e., SiH groups), an organopolysiloxane having an alkenyl group such as a silicon-bonded vinyl group, and an addition reaction catalyst. It is prepared as an addition reaction-curable organopolysiloxane composition in which a cured product is obtained by the addition reaction of the silicon-bonded hydrogen atoms to alkenyl groups. The cured silicone gel obtained by heating this curable silicone gel composition has excellent heat resistance, weather resistance, oil resistance, cold resistance, electrical insulation, etc., and has a low elastic modulus and low stress. It is used to protect electronic parts such as in-vehicle electronic parts and consumer electronic parts. The low elastic modulus and low stress characteristic of cured silicone gels cannot be found in other elastomer products.

In addition, in recent years, due to the demand for higher reliability of automotive electronic parts and consumer electronic parts, there is a demand for materials that can maintain a low elastic modulus over a wide temperature range for cured silicone gels used for sealing. is rising. These conventional silicone gel cured products are used by filling or potting a component with a liquid silicone composition and curing it by heating. It has the disadvantage that it cannot be reused or replaced.

In order to solve such problems, a curable silicone composition comprising a branched organopolysiloxane having alkenyl groups, an organopolysiloxane having silicon-bonded hydrogen atoms, and a platinum-based catalyst for hydrosilylation reaction is generally used. Furthermore, curable silicone compositions containing inorganic fillers such as silica powder as optional components (JP-A-58-7452, JP-A-62-181357, JP-A-63-246856, Japanese Patent Application Laid-Open Nos. 5-70693 and 10-212413 (Patent Documents 1 to 5)) propose that inorganic fillers such as silica powder are used to impart strength to silicone gels. Such curable silicone compositions are used as sealing/filling agents for electric/electronic parts such as ICs (Integrated Circuits), MPUs (Micro Processing Units), and transistors (JP-A-63-246856). , and Japanese Patent Application Laid-Open No. 10-212413 (see Patent Documents 3 and 5)), the silicone gel obtained by curing tends to crack, so it cannot be peeled off cleanly, and there is a problem that repairability is poor. .

Therefore, in Japanese Patent Application Laid-Open No. 2000-327921 (Patent Document 6), alumina powder is added to the curable composition that cures by the above hydrosilylation reaction to increase the strength of the silicone gel, thereby enhancing the releasability. is proposed. However, since the amount of alumina powder used is too large, problems such as not forming a silicone gel (gel-like cured product) and being heavy have arisen.

In recent years, in the medical field and health care field, there is an increasing demand for adhesive sheets for use in transdermal absorption preparations and cosmetics, and various sheet materials for skin application have been proposed. Among them, in recent years, in applications for skin attachment, studies have been conducted using crosslinked or uncrosslinked silicone pressure-sensitive adhesives in place of conventionally used acrylic or rubber-based pressure-sensitive adhesives (Patent Document 7: Japanese Laid-Open Patent Publication No. 3-200885). However, when the silicone pressure-sensitive adhesive is cross-linked, the inherent adhesive physical properties (tackiness, adhesive strength) of the silicone pressure-sensitive adhesive are reduced, resulting in a problem of reduced suitability for skin application pressure-sensitive adhesives. When the adhesive is not crosslinked, there is a problem that the adhesive remains on the skin surface after peeling.

In order to solve such problems, a base polymer using two types of polysiloxanes with different functional groups in a specific ratio, a specific organopolysiloxane, an organohydrogenpolysiloxane, and a platinum group metal catalyst are included. An addition-curable silicone pressure-sensitive adhesive composition has been proposed (Patent Document 8: Japanese Patent Application Laid-Open No. 2020-011919). However, this silicone adhesive composition had to be diluted with an aliphatic hydrocarbon solvent. In addition, in such fields, when a cured product obtained by curing a silicone composition is used, it cannot be used because of the problem of poor persistence of sticking to the skin and peeling off over time.
In addition to the documents mentioned above, the following documents can be cited as conventional techniques related to the present invention.

JP-A-58-7452 JP-A-62-181357 JP-A-63-246856 JP-A-5-70693 JP-A-10-212413 JP-A-2000-327921 JP-A-3-200885 JP 2020-011919 A U.S. Pat. No. 3,220,972 U.S. Pat. No. 3,159,601 U.S. Pat. No. 3,159,662 U.S. Pat. No. 3,775,452

The present invention has been made to solve such problems, and a single-sided adhesive or double-sided adhesive silicone gel sheet having an adhesive silicone gel layer obtained by curing a curable silicone gel composition has adhesive properties. The surface adhesiveness of the adhesive silicone gel layer is high, and the adhesive silicone gel sheet is difficult to peel off after being attached, and at the same time, it can be peeled off without destroying the adhesive silicone gel layer when peeled off, single-sided adhesiveness or double-sided adhesiveness. An object of the present invention is to provide a flexible silicone gel sheet and an article using the silicone gel sheet.

As a result of intensive studies to achieve the above object, the present inventors have found that (A) a linear organopolysiloxane having one vinyl group bonded to a silicon atom at each end of the molecular chain as a base polymer; (B) an organohydrogenpolysiloxane having a three-dimensional network structure containing diorganohydrogensiloxy units ((H(R) ₂ SiO _1/2 ) units) and SiO _4/2 units as essential structural units (wherein R represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond.), and (C) a straight-chain having a silicon-bonded hydrogen atom (SiH group) only at the end of the molecular chain Alternatively, branched methylhydrogenpolysiloxane is adjusted to a specific blending ratio, and (D) an adhesive silicone gel layer composed of a silicone gel cured product obtained by curing in the presence of an addition reaction catalyst is laminated. A single-sided adhesive or double-sided adhesive silicone gel sheet, wherein the molar ratio (Hb/Hc) of SiH groups (Hb) in component (B) to SiH groups (Hc) in component (C) is 0.10 to 1.50 and the penetration of the cured silicone gel (according to JIS K2220) is 30 to 80. A decrease in the loss factor (tan δ) in the frequency range is suppressed, and the cured silicone gel product maintains a relatively large loss factor (tan δ) over a wide shear frequency range from low to high frequencies. Since the frequency dependence of the loss factor (tan δ) is small, it becomes an adhesive silicone gel sheet with good adhesiveness to a wide range of substrates such as human skin, metals, and plastics. It has been found that the gel layer can be peeled off without destroying it.
In addition, the curable silicone gel composition before curing has good fluidity, and the reaction progresses quickly even at relatively low temperatures, making it possible to obtain a silicone gel cured product in a short period of time. The present inventors have found that the adhesive silicone gel sheet that can be used in a wide range of fields can be obtained by preventing the thermal deterioration of the drug and the like, and have completed the present invention.

（式中、Ｒ¹はメチル基又はフェニル基であり、同一シロキサン単位中の２個のＲ¹のうち少なくとも１個はフェニル基である。ｘは１５０～８００の整数、ｙは０～５０の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。）
で表され、２３℃における粘度が５００～５０，０００ｍＰａ・ｓであるケイ素原子に結合したビニル基を分子鎖両末端にそれぞれ１個ずつ有する直鎖状オルガノポリシロキサン：１００質量部、
（Ｂ）（Ｈ（Ｒ）₂ＳｉＯ_1/2）単位とＳｉＯ_4/2単位を必須構成単位として含有する三次元網状構造のオルガノハイドロジェンポリシロキサン（式中、Ｒは脂肪族不飽和結合を含まない非置換又は置換１価炭化水素基を示す。）：０．０１～１０質量部、
（Ｃ）下記一般式（２）

［式中、ｍは０又は１であり、ｎは１０～５００の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。Ｚは下記式（３）で示される基である。

（式中、ｎは上記の通りである。）］
で表される、ケイ素原子に結合した水素原子（ＳｉＨ基）を分子鎖末端にのみ有する直鎖状又は分岐鎖状メチルハイドロジェンポリシロキサン：０．１～５０質量部、
（Ｄ）付加反応触媒：有効量
［２］
（Ｄ）成分の付加反応触媒が白金族金属系触媒である［１］に記載の片面粘着性シリコーンゲルシート。
［３］
（Ａ）成分中のビニル基（Ｖｉ）に対する（Ｂ）成分及び（Ｃ）成分中のケイ素原子に結合した水素原子の合計（Ｈ）のモル比（Ｈ／Ｖｉ）が０．６～１．５である［１］又は［２］に記載の片面粘着性シリコーンゲルシート。
［４］
シリコーンゲル硬化物の２３℃での損失係数（ｔａｎδ）がせん断周波数０．１～５０Ｈｚにおいて０．３～１．０である［１］～［３］のいずれかに記載の片面粘着性シリコーンゲルシート。
［５］
粘着性シリコーンゲル層の２３℃での表面粘着力の最大点強度が１．０～１０．０ｇｆ／ｍｍである［１］～［４］のいずれかに記載の片面粘着性シリコーンゲルシート。
［６］
基材が、プラスチックフィルム、ラミネートフィルム、不織布及び布から選ばれるものである［１］～［５］のいずれかに記載の片面粘着性シリコーンゲルシート。
［７］
基材の厚さが１～２，０００μｍであり、粘着性シリコーンゲル層の厚さが２～２，０００μｍである［１］～［６］のいずれかに記載の片面粘着性シリコーンゲルシート。
［８］
粘着性シリコーンゲル層を粘着対象基材に粘着させたのち、粘着対象基材から剥離する際に粘着性シリコーンゲル層を破壊せず剥離することができるものである［１］～［７］のいずれかに記載の片面粘着性シリコーンゲルシート。
［９］
下記（Ａ）～（Ｄ）成分を必須成分として含有し、かつフィラーを含有しない硬化性シリコーンゲル組成物の硬化物である粘着性シリコーンゲル層からなる単層構造の両面粘着性シリコーンゲルシートであって、（Ｃ）成分中のＳｉＨ基（Ｈｃ）に対する（Ｂ）成分中のＳｉＨ基（Ｈｂ）のモル比（Ｈｂ／Ｈｃ）が０．１０～１．５０であり、かつシリコーンゲル硬化物の針入度（ＪＩＳ Ｋ２２２０に準拠）が３０～８０である両面粘着性シリコーンゲルシート。
（Ａ）下記一般式（１）

（式中、Ｒ¹はメチル基又はフェニル基であり、同一シロキサン単位中の２個のＲ¹のうち少なくとも１個はフェニル基である。ｘは１５０～８００の整数、ｙは０～５０の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。）
で表され、２３℃における粘度が５００～５０，０００ｍＰａ・ｓであるケイ素原子に結合したビニル基を分子鎖両末端にそれぞれ１個ずつ有する直鎖状オルガノポリシロキサン：１００質量部、
（Ｂ）（Ｈ（Ｒ）₂ＳｉＯ_1/2）単位とＳｉＯ_4/2単位を必須構成単位として含有する三次元網状構造のオルガノハイドロジェンポリシロキサン（式中、Ｒは脂肪族不飽和結合を含まない非置換又は置換１価炭化水素基を示す。）：０．０１～１０質量部、
（Ｃ）下記一般式（２）

［式中、ｍは０又は１であり、ｎは１０～５００の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。Ｚは下記式（３）で示される基である。

（式中、ｎは上記の通りである。）］
で表される、ケイ素原子に結合した水素原子（ＳｉＨ基）を分子鎖末端にのみ有する直鎖状又は分岐鎖状メチルハイドロジェンポリシロキサン：０．１～５０質量部、
（Ｄ）付加反応触媒：有効量
［１０］
（Ｄ）成分の付加反応触媒が白金族金属系触媒である［９］に記載の両面粘着性シリコーンゲルシート。
［１１］
（Ａ）成分中のビニル基（Ｖｉ）に対する（Ｂ）成分及び（Ｃ）成分中のケイ素原子に結合した水素原子の合計（Ｈ）のモル比（Ｈ／Ｖｉ）が０．６～１．５である［９］又は［１０］に記載の両面粘着性シリコーンゲルシート。
［１２］
シリコーンゲル硬化物の２３℃での損失係数（ｔａｎδ）がせん断周波数０．１～５０Ｈｚにおいて０．３～１．０である［９］～［１１］のいずれかに記載の両面粘着性シリコーンゲルシート。
［１３］
粘着性シリコーンゲル層の２３℃での表面粘着力の最大点強度が１．０～１０．０ｇｆ／ｍｍである［９］～［１２］のいずれかに記載の両面粘着性シリコーンゲルシート。
［１４］
厚さが０．１～３００ｍｍである［９］～［１３］のいずれかに記載の両面粘着性シリコーンゲルシート。
［１５］
粘着対象基材に粘着させたのち、粘着対象基材から剥離する際に粘着性シリコーンゲル層を破壊せず剥離することができるものである［９］～［１４］のいずれかに記載の両面粘着性シリコーンゲルシート。
［１６］
［１］～［１５］のいずれかに記載の片面粘着性又は両面粘着性シリコーンゲルシートを用いた物品。 Accordingly, the present invention provides the following single-sided adhesive or double-sided adhesive silicone gel sheets and articles using the silicone gel sheets.
[1]
Adhesive silicone consisting of a cured product of a curable silicone gel composition containing no filler and containing the following components (A) to (D) as essential components on one outer surface of a sheet-like or film-like substrate. A single-sided adhesive silicone gel sheet formed by laminating a gel layer, wherein the molar ratio (Hb/Hc) of SiH groups (Hb) in component (B) to SiH groups (Hc) in component (C) is 0.0. 10 to 1.50, and a cured silicone gel sheet having a penetration of 30 to 80 (according to JIS K2220).
(A) the following general formula (1)

(wherein R ¹ is a methyl group or a phenyl group, at least one of the two R ^1s in the same siloxane unit is a phenyl group, x is an integer of 150-800, y is a is an integer, and the arrangement of each parenthesized siloxane unit may be arbitrary.)
Linear organopolysiloxane having a silicon-bonded vinyl group at each end of the molecular chain and having a viscosity of 500 to 50,000 mPa s at 23° C.: 100 parts by mass,
(B) an organohydrogenpolysiloxane having a three-dimensional network structure containing (H(R) ₂ SiO _1/2 ) units and SiO _4/2 units as essential structural units (wherein R represents an aliphatic unsaturated bond; Indicates an unsubstituted or substituted monovalent hydrocarbon group that does not contain.): 0.01 to 10 parts by mass,
(C) the following general formula (2)

[In the formula, m is 0 or 1, n is an integer of 10 to 500, and the arrangement of each bracketed siloxane unit may be arbitrary. Z is a group represented by the following formula (3).

(Wherein, n is as described above.)]
Linear or branched chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms (SiH groups) only at the molecular chain terminals represented by: 0.1 to 50 parts by mass,
(D) addition reaction catalyst: effective amount [2]
The single-sided adhesive silicone gel sheet according to [1], wherein the addition reaction catalyst of component (D) is a platinum group metal catalyst.
[3]
The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl groups (Vi) in component (A) is 0.6 to 1.0. 5, the single-sided adhesive silicone gel sheet according to [1] or [2].
[4]
The single-sided adhesive silicone gel sheet according to any one of [1] to [3], wherein the cured silicone gel has a loss factor (tan δ) at 23°C of 0.3 to 1.0 at a shear frequency of 0.1 to 50 Hz. .
[5]
The single-sided adhesive silicone gel sheet according to any one of [1] to [4], wherein the adhesive silicone gel layer has a maximum surface adhesive force strength of 1.0 to 10.0 gf/mm at 23°C.
[6]
The single-sided adhesive silicone gel sheet according to any one of [1] to [5], wherein the substrate is selected from plastic films, laminated films, nonwoven fabrics and cloth.
[7]
The single-sided adhesive silicone gel sheet according to any one of [1] to [6], wherein the substrate has a thickness of 1 to 2,000 μm and the adhesive silicone gel layer has a thickness of 2 to 2,000 μm.
[8]
[1] to [7], in which the adhesive silicone gel layer can be adhered to the adhesive target substrate and then peeled off from the adhesive target substrate without destroying the adhesive silicone gel layer. A single-sided adhesive silicone gel sheet according to any one of the above.
[9]
A double-sided adhesive silicone gel sheet with a single-layer structure consisting of an adhesive silicone gel layer that is a cured product of a curable silicone gel composition that contains the following components (A) to (D) as essential components and does not contain a filler. and the molar ratio (Hb/Hc) of the SiH groups (Hb) in component (B) to the SiH groups (Hc) in component (C) is 0.10 to 1.50, and the silicone gel cured product A double-sided adhesive silicone gel sheet with a penetration (according to JIS K2220) of 30-80.
(A) the following general formula (1)

(wherein R ¹ is a methyl group or a phenyl group, at least one of the two R ^1s in the same siloxane unit is a phenyl group, x is an integer of 150-800, y is a is an integer, and the arrangement of each parenthesized siloxane unit may be arbitrary.)
Linear organopolysiloxane having a silicon-bonded vinyl group at each end of the molecular chain and having a viscosity of 500 to 50,000 mPa s at 23° C.: 100 parts by mass,
(B) an organohydrogenpolysiloxane having a three-dimensional network structure containing (H(R) ₂ SiO _1/2 ) units and SiO _4/2 units as essential structural units (wherein R represents an aliphatic unsaturated bond; Indicates an unsubstituted or substituted monovalent hydrocarbon group that does not contain.): 0.01 to 10 parts by mass,
(C) the following general formula (2)

[In the formula, m is 0 or 1, n is an integer of 10 to 500, and the arrangement of each bracketed siloxane unit may be arbitrary. Z is a group represented by the following formula (3).

(Wherein, n is as described above.)]
Linear or branched chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms (SiH groups) only at the molecular chain terminals represented by: 0.1 to 50 parts by mass,
(D) addition reaction catalyst: effective amount [10]
The double-sided adhesive silicone gel sheet according to [9], wherein the addition reaction catalyst of component (D) is a platinum group metal catalyst.
[11]
The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl groups (Vi) in component (A) is 0.6 to 1.0. 5. The double-sided adhesive silicone gel sheet according to [9] or [10].
[12]
The double-sided adhesive silicone gel sheet according to any one of [9] to [11], wherein the cured silicone gel has a loss factor (tan δ) at 23°C of 0.3 to 1.0 at a shear frequency of 0.1 to 50 Hz. .
[13]
The double-sided adhesive silicone gel sheet according to any one of [9] to [12], wherein the adhesive silicone gel layer has a maximum surface adhesive strength at 23°C of 1.0 to 10.0 gf/mm.
[14]
The double-sided adhesive silicone gel sheet according to any one of [9] to [13], which has a thickness of 0.1 to 300 mm.
[15]
Both sides according to any one of [9] to [14], which can be peeled off from the adhesive target substrate without destroying the adhesive silicone gel layer after being adhered to the adhesive target substrate. Adhesive silicone gel sheet.
[16]
An article using the single-sided adhesive or double-sided adhesive silicone gel sheet according to any one of [1] to [15].

In the single-sided adhesive or double-sided adhesive silicone gel sheet of the present invention, the cured silicone gel (adhesive silicone gel layer) has high surface adhesiveness and a wide shear frequency range from low to high frequencies. A decrease in the loss factor (tan δ) is suppressed over a wide range of shear frequencies, a relatively large loss factor (tan δ) is maintained over a wide range of shear frequencies, and the frequency dependence of the loss factor (tan δ) is small. After that, it becomes an adhesive silicone gel sheet that is difficult to peel off and can be peeled off without destroying the adhesive silicone gel layer. Therefore, an adhesive silicone gel sheet that sticks only on one side is expected to be used for medical and healthcare applications. When used for medical and healthcare applications, it can prevent peeling over time by maintaining appropriate adhesiveness, and the adhesive silicone gel layer does not break when peeled off, leaving no adhesive silicone gel layer on the skin. In addition, there is no excessive peeling of the keratin of the skin when peeling it off, and there is no pain or discomfort caused by the pulling of body hair, or secondary inflammation caused by excessive irritation to the skin. It becomes a sticky silicone gel sheet. Adhesive silicone gel sheets with adhesive on both sides are expected to be used for automotive electronic parts, consumer electronic parts, and the like. When used in automotive electronic parts and consumer electronic parts, it facilitates the reuse and replacement of parts, leading to improved productivity and reduced waste.

FIG. 4 is a schematic explanatory diagram showing a test piece preparation process for a shear adhesion test used in the examples of the present invention. 4 is a graph showing the frequency dependence of the loss factor (tan δ) measured in Examples 1 to 3 of the present invention; 5 is a graph showing the frequency dependence of the loss factor (tan δ) measured in Comparative Examples 1 to 3 of the present invention; 5 is a graph showing the frequency dependence of the loss factor (tan δ) measured in Comparative Examples 4 to 7 of the present invention;

The adhesive silicone gel sheet of the present invention (hereinafter sometimes referred to as an adhesive gel sheet) contains the following components (A) to (D) as essential components, and is obtained by curing a filler-free curable silicone gel composition. A single-sided adhesive or double-sided adhesive gel sheet having an adhesive silicone gel layer consisting of a molar ratio of SiH groups (Hb) in component (B) to SiH groups (Hc) in component (C) (Hb/Hc) is 0.10 to 1.50, and the cured silicone gel sheet has a penetration of 30 to 80 (according to JIS K2220). Such an adhesive gel sheet is a two-layered adhesive gel sheet having adhesiveness on only one side or a single-layered adhesive gel sheet having adhesiveness on both sides. In the present invention, the adhesive gel sheet refers to adhesiveness derived from a cured product obtained by curing a curable silicone gel composition containing no filler and containing the following components (A) to (D) as essential components. The cured product of the curable silicone gel composition constituting the adhesive silicone gel layer (silicone gel cured product) is a cured product containing organopolysiloxane as a main component and having a low cross-linking density. Consistency (that is, cone penetration) measured by a method based on K2220 (1/4 cone). The 1/4 cone specified in JIS K2220 has a tip needle (hardness is Rockwell C Since the structure is equipped with a hardened steel needle with a scale of 45 to 50), in the present invention, the consistency may be referred to as needle penetration. The same shall apply hereinafter.) is 10-100, preferably 30-80. This corresponds to a material having a measured value (rubber hardness value) of 0 in the rubber hardness measurement according to JIS K6253, which is so low that it does not exhibit an effective rubber hardness value (i.e., low stress and soft). In this respect, it is different from the so-called cured silicone rubber (silicone rubber-like elastic material, silicone elastomer). In addition, the adhesiveness described here means that the adhesive gel sheet cannot be peeled off unless a stress is applied in the peeling direction when the adhesive gel sheet is attached to the base material and then peeled off.

Each component of the curable silicone gel composition used in the adhesive gel sheet of the present invention is described in detail below. In addition, in this specification, the viscosity is a value at 23°C.

（式中、Ｒ¹はメチル基又はフェニル基であり、同一シロキサン単位中の２個のＲ¹のうち少なくとも１個はフェニル基である。ｘは１５０～８００の整数、ｙは０～５０の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。） [(A) Organopolysiloxane]
Component (A) is the main ingredient (base polymer) of the curable silicone gel composition. The component (A) is represented by the following general formula (1) and has a viscosity at 23° C. of 500 to 50,000 mPa·s. It is a chain organopolysiloxane.

(wherein R ¹ is a methyl group or a phenyl group, at least one of the two R ^1s in the same siloxane unit is a phenyl group, x is an integer of 150-800, y is a is an integer, and the arrangement of each parenthesized siloxane unit may be arbitrary.)

In formula (1) above, x must be an integer of 150-800, preferably an integer of 300-600. If x is less than 150, the viscosity of the base polymer of component (A) will be low and the amount of reactive vinyl groups will be large, resulting in poor adhesion of the resulting adhesive silicone gel layer (cured silicone gel). Sex may get worse. On the other hand, if x exceeds 800, the base polymer viscosity of the component (A) increases, which adversely affects workability.

y must be an integer of 0 to 50, and when an adhesive silicone gel layer with a small change in elastic modulus even at -40°C or lower is required, the value of y is preferably an integer of 3 to 30. and more preferably an integer of 5-20. Here, if y is less than 3, there is a possibility that expected cold resistance cannot be obtained. The value of y is preferably 0 if use under low temperature conditions as described above is not assumed. Further, if y is a value exceeding 50, the base polymer viscosity of the component (A) becomes high, which adversely affects workability, and the number of phenyl groups is too large, resulting in poor defoaming. may get worse. The number of phenyl groups in the molecule is preferably 0 to 50, and when an adhesive silicone gel layer having a small change in elastic modulus even at −40° C. or below is required, 3 to 30, particularly 5 to 5 It is preferable to have 20. In the present invention, the molecular weight (or the number of repeating siloxane units in the molecule (degree of polymerization)) is, for example, a polystyrene-equivalent number-average molecular weight (or number average degree of polymerization), etc. (hereinafter the same).

The viscosity of the component (A) organopolysiloxane is 500 to 50,000 mPa· at 23° C. from the viewpoint of good handling workability and fluidity of the composition and the strength of the resulting adhesive silicone gel layer. s, preferably 2,000 to 10,000 mPa·s. The viscosity can be measured by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.) (same below).

Also, the organopolysiloxane of component (A) may be used alone or in combination of two or more.

[(B) Three-dimensional network organohydrogenpolysiloxane]
Component (B) is a component that forms a cross-linking point when the curable silicone gel composition is cross-linked. It is an essential component for providing the adhesive silicone gel layer with adequate strength so that the gel layer does not break.

The component (B) organohydrogenpolysiloxane contains (H(R) ₂ SiO _1/2 ) units (hereinafter abbreviated as M ^H units) and SiO _4/2 units (hereinafter abbreviated as Q units). An organohydrogenpolysiloxane with a three-dimensional network structure containing as an essential structural unit (wherein R represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bonds), and in the molecule It refers to an organohydrogenpolysiloxane with a three-dimensional network structure that always contains two or more M ^H units and one or more Q units in the molecule. Here, the M ^H unit and the Q unit are essential units in the molecule, but in the molecule there are (R) ₃ SiO _1/2 units (hereinafter abbreviated as M units, where R is the same as above), (R) SiO _3/2 units (hereinafter abbreviated as T units, R is the same as above) and HSiO _3/2 units (hereinafter abbreviated as T ^H units) optionally containing three-dimensional network structure organohydrogenpolysiloxanes It is possible to sufficiently obtain the effects of the present invention even when using . The three-dimensional network-like organohydrogenpolysiloxane containing M ^H units and Q units, which is the component (B), may be used alone or in combination of two or more.

The molar ratio of M ^H units to Q units in the molecule; [M ^H ]/[Q] is preferably about 0.3 to 2.0, particularly about 0.5 to 1.6 The sum of M ^H units and Q units to all siloxane units in the molecule is preferably 50 mol % or more (ie, 50 to 100 mol %), particularly 75 mol % or more (75 to 100 mol %).
Therefore, the total of M units, T units and T ^units , which are optional structural units, is 50 mol% or less (0 to 50 mol%), particularly 25 mol% or less (0 to 25 mol%). desirable.

In the above formula, R is independently an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, and usually has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclohexyl, octyl, and decyl; phenyl; , an aryl group such as a tolyl group; an aralkyl group such as a benzyl group and a phenylethyl group; 3,3-trifluoropropyl group and the like. Among them, a methyl group is preferable because it is easy to synthesize.

The amount of silicon-bonded hydrogen atoms (SiH groups) contained in the three-dimensional network organohydrogenpolysiloxane containing M ^H units and Q units of component (B) is 0.001 to 0.1 mol/g. preferably 0.003 to 0.05 mol/g. If the amount of SiH groups is less than 0.001 mol/g, the resulting curable silicone gel composition may not be sufficiently crosslinked, and the strength of the resulting adhesive silicone gel layer may decrease. If it is more than 0.1 mol/g, the resulting adhesive silicone gel layer may become brittle due to too many cross-linking points.

The SiH groups (Hb) contained in the three-dimensional network organohydrogenpolysiloxane containing M ^H units and Q units of component (B) are hydrogen atoms bonded to silicon atoms of component (C), which will be described later. The molar ratio to the SiH group (Hc) contained in the organohydrogenpolysiloxane at the end of the molecular chain must be within the range of 0.10 ≤ (Hb/Hc) ≤ 1.50. , 0.20≦(Hb/Hc)≦1.20. This is because when (Hb/Hc) is less than 0.10, the ratio of component (B) introduced as a cross-linking point decreases, so that the resulting curable silicone gel composition cannot be sufficiently cross-linked. , the strength of the resulting adhesive silicone gel layer is low. On the other hand, when (Hb/Hc) exceeds 1.50, the loss factor (tan δ) at a specific frequency of the resulting adhesive silicone gel layer decreases, resulting in decreased adhesiveness or too many cross-linking points. Therefore, the obtained adhesive silicone gel layer becomes brittle.

The viscosity at 23° C. of the three-dimensional network organohydrogenpolysiloxane containing M ^H units and Q units as component (B) is preferably 5 to 300 mPa·s, more preferably 10 to 200 mPa·s. preferable. If the viscosity is too low, the viscosity of the resulting curable silicone gel composition will be low, resulting in poor workability, and the cross-linking points will become dense, resulting in a loss factor (tan δ) of the resulting adhesive silicone gel layer at a specific frequency. If the viscosity is too high, the resulting curable silicone gel composition will have a high viscosity, which may adversely affect workability.

Component (B) is added in an amount of 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, per 100 parts by mass of organopolysiloxane (A). If the amount is less than 0.01 parts by mass, the strength of the resulting adhesive silicone gel layer will be insufficient, and the adhesive silicone gel layer will break when it is removed after application, or in the worst case, a cured product will be obtained. may not be If the amount exceeds 10 parts by mass, the loss factor (tan δ) of the resulting adhesive silicone gel layer at a specific frequency will decrease, resulting in a decrease in adhesiveness or excessive cross-linking points. layers become brittle.
The (B) component organohydrogenpolysiloxane may be used alone or in combination of two or more.

［式中、ｍは０又は１であり、ｎは１０～５００の整数であり、括弧が付された各シロキサン単位の配列は任意であってよい。Ｚは下記式（３）で示される基である。

（式中、ｎは上記の通りである。）］
で表される、ケイ素原子に結合した水素原子（ＳｉＨ基）を分子鎖末端にのみ有する直鎖状又は分岐鎖状メチルハイドロジェンポリシロキサンである。 [(C) Straight-chain or branched-chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms only at the ends of the molecular chain]
The component (C) reacts with the components (A) and (B) to act as a cross-linking agent to cross-link them. Component (C) has the following general formula (2)

[In the formula, m is 0 or 1, n is an integer of 10 to 500, and the arrangement of each bracketed siloxane unit may be arbitrary. Z is a group represented by the following formula (3).

(Wherein, n is as described above.)]
It is a linear or branched methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms (SiH groups) only at the ends of the molecular chains represented by.

In the above formula (2), m is either 0 or 1. This is due to differences in the amount of SiH contained in the three-dimensional network organohydrogenpolysiloxane containing M ^H units and Q units and the three-dimensional network structure of component (B) used, resulting in an adhesive silicone gel layer (silicone gel layer This is for facilitating adjustment of the hardness of the cured product). If m is 2 or more, the crosslinks become dense, and the loss factor (tan δ) of the resulting adhesive silicone gel layer at a specific frequency decreases, resulting in a decrease in adhesiveness. The layer may become brittle.
In the above formulas (2) and (3), n must be an integer of 10-500, preferably an integer of 20-300. If n is less than 10, the viscosity of the methylhydrogenpolysiloxane of component (C) will be low, resulting in poor workability, and the cross-linking points will be dense, resulting in loss at a specific frequency of the resulting adhesive silicone gel layer. A decrease in the coefficient (tan δ) may result in a decrease in adhesiveness. On the other hand, if n exceeds 500, the viscosity of the component (C) methylhydrogenpolysiloxane increases, which adversely affects workability.
The (C) component methylhydrogenpolysiloxane may be used singly or in combination of two or more having completely different values of m or n.

The amount of silicon-bonded hydrogen atoms (SiH groups) contained in the component (C) methylhydrogenpolysiloxane is preferably 0.0001 to 0.01 mol/g, more preferably 0.0003 to 0.005 mol. /g is more preferred. When the amount of SiH groups is less than 0.0001 mol / g, it is necessary to add a large amount of component (C) in order to achieve the desired effect of suppressing the decrease in the loss factor (tan δ) in the low frequency range. In addition to lowering the viscosity of the curable silicone gel composition, the cured silicone gel composition may not achieve the desired loss factor even when cured, which is disadvantageous in terms of cost. If it is more than 0.01 mol/g, the distance between the cross-linking points becomes narrow, so the loss factor (tan δ) in the low-frequency range of the resulting adhesive silicone gel layer decreases, resulting in a decrease in adhesiveness or cross-linking points. Since the amount is too large, the obtained adhesive silicone gel layer may become brittle.

The viscosity of the component (C) methylhydrogenpolysiloxane at 23° C. is preferably 5 to 300 mPa·s, more preferably 10 to 200 mPa·s. If the viscosity is too low, the resulting curable silicone gel composition will have a low viscosity, resulting in poor workability. ) may decrease the adhesiveness, and if it is too high, the resulting curable silicone gel composition will have a high viscosity, which may adversely affect workability.

Component (C) is added in an amount of 0.1 to 50 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of organopolysiloxane (A). If the amount is less than 0.1 parts by mass, the resulting adhesive silicone gel layer is too soft, and when it is removed after application, the adhesive silicone gel layer may be destroyed, or in the worst case, the adhesive silicone gel layer may be destroyed. You may not get it. On the other hand, when the amount exceeds 50 parts by mass, the loss factor (tan δ) of the resulting adhesive silicone gel layer at a specific frequency decreases and the adhesiveness decreases. The hardness of the silicone gel layer becomes too high.

Here, for the vinyl group (Vi) in the component (A), the three-dimensional network organohydrogenpolysiloxane containing the M ^H unit and the Q unit in the component (B) and the silicon atom in the component (C). The ratio of the total SiH groups (H) contained in the methylhydrogenpolysiloxane having bonded hydrogen atoms only at the ends of the molecular chains is preferably within the range of H/Vi = 0.6 to 1.5 in terms of molar ratio, Among them, H/Vi=0.7 to 1.1 is more preferable. If H/Vi is less than 0.6, the resulting adhesive silicone gel layer is too soft and may break when removed after application, or in the worst case, the adhesive silicone gel layer. may not be obtained. On the other hand, when H/Vi exceeds 1.5, the loss factor (tan δ) of the resulting adhesive silicone gel layer at a specific frequency decreases, resulting in decreased adhesiveness, and the resulting adhesive silicone gel layer becomes brittle. Furthermore, if H/Vi becomes high, SiH groups become excessively large, so that the obtained adhesive silicone gel layer becomes soft, foams over time, and the adhesiveness decreases. Sometimes.

[(D) Addition reaction catalyst]
Next, the addition reaction catalyst of the component (D) is a catalyst for promoting the addition reaction between the vinyl group and the hydrogen atom (that is, SiH group) bonded to the silicon atom, and is used in the hydrosilylation reaction. Examples of the catalyst include well-known catalysts such as platinum group metal-based catalysts.

As the platinum group metal-based catalyst, all known hydrosilylation reaction catalysts can be used. For example, _{simple platinum} group _metals such _{as platinum black , rhodium and palladium ; 6.wH 2} O, K ₂ PtCl ₄ .wH ₂ O, PtCl ₄ .wH ₂ O, PtCl ₂ , Na ₂ HPtCl ₄ .wH ₂ O (wherein w is an integer of 0 to 6, preferably 0 or 6), such as platinum chloride, chloroplatinic acid, and chloroplatinate; alcohol-modified chloroplatinic acid (see, for example, Patent Document 9 cited above); 10 to 12), platinum black, platinum group metals such as palladium supported on carriers such as alumina, silica, carbon; rhodium-olefin complex; chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst); platinum chloride , a complex of chloroplatinic acid or chloroplatinate and a vinyl group-containing siloxane, particularly a vinyl group-containing cyclic siloxane. Among these, from the viewpoint of compatibility and chlorine impurities, chloroplatinic acid modified with silicone is preferable. Specifically, for example, platinum obtained by modifying chloroplatinic acid with tetramethyldivinyldisiloxane. catalysts.

The amount of component (D) added is an effective amount, usually 0.1 to 1,000 ppm in terms of mass of platinum atoms, preferably 0 .5 to 300 ppm, more preferably 1 to 100 ppm.

[Other optional components]
In addition to the above components (A) to (D), the curable silicone gel composition used in the present invention may contain optional components within a range that does not impair the purpose of the present invention. However, inorganic fillers and carbon, which are commonly called fillers, are excluded. Examples of optional components include reaction inhibitors, silicon-bonded hydrogen atom- and silicon-bonded alkenyl group-free organopolysiloxanes, heat resistance imparting agents, and flame retardants when used in automotive electronic parts and consumer electronic parts. A property-imparting agent, a dye, and the like can be mentioned. In addition, when used for medical and healthcare applications, reaction inhibitors, silicon-bonded hydrogen atom- and silicon-bonded alkenyl group-free organopolysiloxanes, modified silicone oils such as polyether-modified organopolysiloxanes and acrylic-modified organopolysiloxanes , unsaturated group-free carboxylic acids and esters, long-chain hydrocarbons such as liquid paraffin, medicaments such as tulobuterol, acetaminophen and ibuprofen.

Here, the reaction inhibitor is a component for inhibiting the reaction of the composition, and specifically includes, for example, acetylene-based, amine-based, carboxylic acid ester-based, phosphorus-based, such as ethynylmethyldecylcarbinol. Reaction inhibitors such as acid esters can be used. However, when the amount of these reaction inhibitors to be added is increased, high-temperature heating is essential, so the amount to be added must be carefully considered. The amount of the reaction control agent to be added is determined in consideration of the structure of the reaction control agent, the working time required for hardening, etc., depending on the purpose. The amount to be added is not particularly limited, but it is preferable to add an effective amount that controls (suppresses) the reaction for achieving the purpose. Specifically, it is preferably about 0.0001 to 10 parts by mass per 100 parts by mass of component (A).

[Preparation and curing of curable silicone gel composition]
The curable silicone gel composition used in the adhesive gel sheet of the present invention is prepared by mixing the above components (A) to (D) (including optional components when optional components are added) in a conventional manner. It can be prepared by At that time, the components to be mixed may be divided into two or more parts as necessary and mixed, for example, a part consisting of a part of component (A) and component (D), ( It is also possible to obtain by mixing the material divided into the remainder of component A and the part consisting of component (B) and component (C).

The uncrosslinked curable silicone composition obtained by mixing can be coated or filled on a substrate as required to obtain a cured silicone gel (adhesive silicone gel layer). In this case, heating makes it possible to obtain the desired cured silicone gel (adhesive silicone gel layer) in a shorter time. A product (adhesive silicone gel layer) can be obtained. When heating, it is necessary to pay attention to the heat resistance temperature of the base material used, but it is preferable to carry out at 150° C. or less.

[Cured product of curable silicone gel composition (cured silicone gel product)]
A silicone gel cured product obtained by curing a curable silicone gel composition that contains the above components (A) to (D) as essential components and does not contain a filler has a loss factor (tan δ) value at 23°C. is within the range of 0.3 or more and 1.0 or less at a shear frequency of 0.1 to 50 Hz, when the adhesive gel sheet using this cured silicone gel (adhesive silicone gel layer) is attached It has sufficient adhesiveness and can be peeled off without destroying the adhesive silicone gel layer. Here, if the loss factor (tan δ) at 23° C. is less than 0.3 at a shear frequency of 0.1 to 50 Hz, that is, the viscosity term of the cured silicone gel in the low-frequency region is too low. The adhesiveness of the adhesive is low, and the possibility of peeling off or falling off due to vibration or shock increases. Conversely, if the loss factor (tan δ) at 23°C exceeds 1.0 at a shear frequency of 0.1 to 50 Hz, that is, the viscosity term of the cured silicone gel is too high in the low-frequency region. Adhesive gel sheets using a cured product (adhesive silicone gel layer) are good when applied, but when removed, the adhesive silicone gel layer is destroyed or the adhesiveness remains on the skin, making it uncomfortable. Sometimes. Thus, the important point of the present invention is that the value of the loss factor (tan δ) at 23° C. of the cured silicone gel at a shear frequency of 0.1 to 50 Hz is in the range of 0.3 to 1.0. Become. In order to keep the value of the loss factor (tan δ) at 23° C. of the cured silicone gel within the above range, it is necessary to The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in the components (B) and (C) to the vinyl groups (Vi) in the component, SiH groups in the component (C) ( This is achieved by setting the molar ratio (Hb/Hc) of SiH groups (Hb) in component (B) to Hc) within the above range.
The value of the loss coefficient (tan δ) of the cured silicone gel is a value obtained by a commercially available viscoelasticity measuring instrument. is described.
Viscoelasticity measuring machine: UBM Co., Ltd. Rheogel-E4000
Measurement conditions: slit shear method (width: 13 mm, depth: 10 mm, interval: 0.25 mm)
Measurement temperature: 23°C
Strain control: 30 μm, 12%
Distorted waveform: sine wave

The silicone gel cured product obtained by curing the above curable silicone gel composition has a penetration of 30 to 80 measured with a 1/4 cone based on the penetration test method described in JIS K2220. It is necessary, preferably 30-75, more preferably 35-70. When the penetration is less than 30, the resulting cured silicone gel (adhesive silicone gel layer) has a lower loss factor (tan δ) at a specific frequency, resulting in lower adhesiveness. Since the hardness of the gel layer) is too hard, the adhesive gel sheet using this may come off or rub off due to vibration, or the vibration absorbency may decrease. Conversely, if the penetration exceeds 80, the resulting cured silicone gel (adhesive silicone gel layer) will be too soft. (cured product of silicone gel) may be destroyed, or stickiness may remain on the skin, causing discomfort. In order to keep the penetration within the above range, the blending amounts of the above-described components (A), (B), and (C), and the vinyl group (Vi) in component (A). And the molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in component (C), SiH groups in component (B) to SiH groups (Hc) in component (C) (Hb ) and the like (Hb/Hc) within the above range.

[Adhesive silicone gel sheet]
The adhesive gel sheet of the present invention does not need to be limited to the application, but it is used for applications where adhesion and adhesion reliability are important (electrical and electronic parts, waterproof seal applications, vehicle applications, architectural anti-vibration applications, etc.), It is suitable for handicraft applications (hobby applications, toy applications, etc.) and medical applications (transdermal absorption preparations, bandages, surgical tapes, plasters, electrode fixing sheets for electrocardiogram measurement, etc.).

[Single-sided adhesive silicone gel sheet]
Here, on the outer surface of one of the sheet-like or film-like substrates, a cured product of a curable silicone gel composition containing the above components (A) to (D) as essential components and containing no filler is formed. Single-sided adhesive silicone gel sheets formed by laminating adhesive silicone gel layers are suitably used for medical applications (transdermal absorption preparations, bandages, surgical tapes, plasters, electrode fixing sheets for electrocardiogram measurement, etc.).

At that time, as the sheet-like or film-like substrate, one selected from plastic films, laminated films, nonwoven fabrics, and cloths can be preferably used. The thickness of the substrate is suitably in the range of 1 to 2,000 μm, preferably 5 to 1,000 μm, more preferably 10 to 300 μm. If the base material is too thick, in the case of medical applications, it may cause problems such as poor feel after application and movement problems during exercise in daily life. may become lower, or it may not be possible to maintain an appropriate shape when pasting.

The method of laminating an adhesive silicone gel layer on one outer surface of a sheet-like or film-like substrate is not particularly limited, but for example, an uncured silicone gel layer may be laminated on one outer surface of the substrate. After applying a curable silicone gel composition to a uniform thickness (predetermined thickness) using a roll, coater, applicator, etc., the composition is allowed to react for a predetermined period of time at room temperature (23°C ± 10°C). A single-sided adhesive silicone gel sheet can be obtained by laminating an adhesive silicone gel layer on one outer surface of a sheet-like or film-like substrate. Here, if heating is required, it is necessary to cure the uncured curable silicone gel composition at a temperature below the heat resistance temperature of the substrate, considering the heat resistance of the sheet or film substrate. There is If necessary, the sticky surface of the sticky silicone gel layer may be covered with a release material (release liner, etc.) to which the sticky silicone gel layer does not stick.

In the single-sided adhesive silicone gel sheet, the appropriate thickness of the adhesive silicone gel layer is in the range of 2 to 2,000 μm, and the preferable thickness of the adhesive silicone gel layer is 5 to 1,000 μm. The thickness of the silicone gel layer is 10-300 μm. If the adhesive silicone gel layer is too thick, the weight of the finished single-sided adhesive silicone gel sheet will be too heavy, so in the case of medical applications, the feel of the sheet will deteriorate after application, and there will be problems when exercising in daily life. If it is too thin, the amount of drug that can be added to the adhesive silicone gel sheet for medical applications will be small, and the expected drug effect will not be obtained. In some cases, problems such as destruction of the silicone gel layer may occur. The thinner the single-sided adhesive silicone gel sheet consisting of a sheet-like or film-like base material and an adhesive silicone gel layer, the less discomfort there is after being applied to the skin or the like.
The thickness of the single-sided adhesive silicone gel sheet (whole) is appropriately in the range of 3-4,000 μm, preferably 10-2,000 μm, more preferably 20-600 μm.

An adhesive comprising a cured product of a curable silicone gel composition containing no filler and containing the above components (A) to (D) as essential components on the outer surface of one of the sheet-like or film-like substrates. In the single-sided adhesive gel sheet obtained by laminating a flexible silicone gel layer, the maximum point strength of the surface adhesive force of the adhesive silicone gel layer is preferably in the range of 1.0 to 10.0 gf / mm, and more It is preferably in the range of 1.0 to 8.0 gf/mm. This is because when the maximum point strength of the surface adhesive force of the adhesive silicone gel layer is less than 1.0 gf/mm, the attached adhesive gel sheet is more likely to peel off, and on the contrary, it is 10.0 gf/mm. If it exceeds, the adhesive strength to the skin is too high, and the keratin of the skin may be exfoliated excessively when peeled off, or the hair may be pulled, causing pain and discomfort, as well as excessive irritation to the skin, resulting in secondary effects. may cause inflammation. In the single-sided adhesive gel sheet, in order to keep the maximum point strength of the surface adhesive force of the adhesive silicone gel layer within the above range, the blending amounts of the components (A), (B), and (C) described above, The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl group (Vi) in component (A), The molar ratio (Hb/Hc) of the SiH groups (Hb) in component (B) to the SiH groups (Hc), the thickness of the adhesive silicone gel layer, etc. are within the above ranges, and the cured silicone gel is cured at 23°C. This is achieved by keeping the value of the loss factor (tan δ) at within a predetermined range.
The method for measuring the maximum point strength of the surface adhesive force of the adhesive silicone gel layer in the single-sided adhesive gel sheet is not particularly limited. can be measured by machine. Examples of the tensile shear adhesion tester include precision universal testing machine Autograph (registered trademark) AGX-VD5kN manufactured by Shimadzu Corporation.

[Double-sided adhesive silicone gel sheet]
In addition, a double-sided adhesive gel sheet with a single-layer structure comprising an adhesive silicone gel layer that is a cured product of a curable silicone gel composition that contains the above components (A) to (D) as essential components and does not contain a filler. is suitable for applications where adhesion and adhesion reliability are important (electric and electronic parts, waterproof seal applications, automotive applications, anti-vibration applications for construction, etc.) and handicraft applications (hobbies, toys, etc.). can.
As the base material to be adhered (substrate to be adhered), for example, engineering plastics such as polybutylene terephthalate (PBT) and polyphenylene sulfide (PPS), organic resins such as general-purpose plastics such as epoxy resins, polyester resins and polycarbonate resins, Base materials of various materials such as metals such as aluminum and iron, glass, and ceramics can be applied.

A method for preparing a double-sided adhesive gel sheet with a single-layer structure consisting of an adhesive silicone gel layer can be obtained by press molding, and uses a material (liner) that makes the double-sided adhesive gel sheet non-adhesive on the top and bottom of the mold. becomes a product.

In this case, the thickness of the double-sided adhesive gel sheet is suitably in the range of 0.1-300 mm, preferably in the range of 0.5-200 mm, more preferably in the range of 1-100 mm. If the double-sided adhesive gel sheet is too thick, it will become heavy, and if the cured adhesive silicone gel layer is deformed due to vibration or expansion, the cured adhesive silicone gel layer will crack or, in the worst case, break. If it is too thin, for example, the double-sided adhesive gel sheet will deteriorate in sealing functionality as a waterproof sealant, which is a suitable application, and deterioration in vibration durability and variation followability in automotive applications, vibration isolation applications for construction, etc. decline may occur.

In addition, a double-sided adhesive gel sheet with a single-layer structure comprising an adhesive silicone gel layer that is a cured product of a curable silicone gel composition that contains the above components (A) to (D) as essential components and does not contain a filler. , the maximum point strength of the surface adhesive force of the adhesive silicone gel layer is preferably in the range of 1.0 to 10.0 gf/mm, more preferably in the range of 1.0 to 8.0 gf/mm. is preferably This is because if the maximum point strength of the surface adhesive force of the adhesive silicone gel layer is less than 1.0 gf/mm, the double-sided adhesive gel sheet attached to it is more likely to peel off, and on the contrary, it is 10.0 gf/mm. If the double-sided adhesive gel sheet becomes old, the adhesive strength becomes too high and workability decreases when replacing it or re-installing it, and in the worst case, the double-sided adhesive gel sheet breaks and remains on the substrate surface. may be lost. In the double-sided adhesive gel sheet, in order to keep the maximum point strength of the surface adhesive force of the adhesive silicone gel layer within the above range, the blending amounts of the components (A), (B), and (C) described above, The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl group (Vi) in component (A), This is achieved by setting the molar ratio (Hb/Hc) of the SiH groups (Hb) in the component (B) to the SiH groups (Hc), the thickness of the adhesive silicone gel layer, etc. within the above ranges.
The method for measuring the maximum point strength of the surface adhesive force of the adhesive silicone gel layer in the double-sided adhesive gel sheet is not particularly limited. can be measured by machine. Examples of the tensile shear adhesion tester include precision universal testing machine Autograph (registered trademark) AGX-VD5kN manufactured by Shimadzu Corporation.

The single-sided or double-sided adhesive silicone gel sheet of the present invention has moderate adhesiveness, and the cured adhesive silicone gel layer has a reduced loss factor (tan δ) over a wide range of shear frequencies from low to high frequencies. is suppressed, a relatively large loss factor (tan δ) is maintained over a wide range of shear frequencies, the frequency dependency of the loss factor (tan δ) is small, and a high-strength adhesive silicone gel layer with excellent stress relaxation is provided. Therefore, after the adhesive silicone gel layer has adhered to the adhesive target substrate, the adhesive silicone gel layer can be peeled off from the adhesive target substrate without breaking the adhesive silicone gel layer.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the following examples are not intended to limit the present invention in any way. In the examples, "part" represents "mass part", "%" represents "mass%", and "Vi" represents "vinyl group". In addition, M ^H units represent (H(CH ₃ ) ₂ SiO _1/2 ) units, and Q units represent SiO _4/2 units. The viscosity was measured with a rotational viscometer at 23°C. Penetration, adhesive strength and loss factor (tan δ) were measured by the methods described below. The maximum point strength of adhesive force (surface adhesive force) was measured using a precision universal testing machine Autograph (registered trademark) AGX-VD5kN manufactured by Shimadzu Corporation as a tensile shear adhesion tester.

[Penetration]
The penetration of the cured silicone gel used for the adhesive gel sheet was measured by placing the uncured curable silicone gel composition in a cylindrical container (inner dimensions: diameter 30 mmφ x depth 15 mm) at 23°C for 24 hours and 80°C. Cured product samples were prepared under two curing conditions of °C x 30 minutes, and measured using a 1/4 cone specified in JIS K2220. At that time, the penetration was measured using an automatic penetration meter RPM-101 manufactured by Rigosha Co., Ltd., passing those of 30 to 80, those of less than 30, those exceeding 80, and uncured. was judged to be unacceptable.

[Adhesive force]
The adhesive force of the adhesive silicone gel layer used in the resulting adhesive gel sheet was measured as follows. At that time, the uncured curable silicone gel composition was cured under two conditions: 23° C.×24 hours and 80° C.×30 minutes. Moreover, pass/fail judgment of various tests was performed as follows.

Adhesion (1);
Maximum adhesive strength to human skin (measurement of maximum adhesive strength of adhesive gel sheets that adhere only to one side)
An uncured curable silicone gel composition was applied to a PET film measuring 30 mm wide x 20 cm long x 20 µm thick using an applicator to a thickness of about 70 µm, cured, and adhered to one side of the PET film. A single-sided adhesive gel sheet with a silicone gel layer was obtained. After that, the adhesive surface of the prepared single-sided adhesive gel sheet was attached to the upper arm of the right hand, left at 23°C for about 30 minutes, and then measured with a tensile shear adhesion tester at a temperature of 23°C and a tensile speed of 60 mm/min. A 90-degree peel was carried out using a knife, and the maximum point strength obtained at the time of peeling was measured. At that time, those that were 1.0 to 10.0 gf / mm were accepted, values that deviated from the above values, or adhesive (adhesive silicone gel layer) remained on the skin after the tensile test and felt uncomfortable. was judged to be unsatisfactory.

Adhesion (2);
Adhesive strength to metal (adhesive strength measurement of adhesive gel sheet with adhesive on both sides)
The curable silicone gel composition was cured by press molding so as to have a length of 1.0 cm, a width of 2.5 cm, and a thickness of 2 mm to obtain a double-sided adhesive gel sheet. It was placed on an aluminum substrate 1 of 0 cm×2.5 cm wide×1.0 mm thick. After that, another aluminum substrate 1 was placed on the surface of the double-sided adhesive gel sheet 2 so that the adhesive area was 2.5 cm ² , and left to stand for 1 hour or more to prepare a test piece for the shear adhesion test. After that, the shear force obtained by pulling the test piece in the shear direction at a measurement temperature of 23° C. at a tensile speed of 50 mm/min using a tensile shear adhesion tester was measured as the adhesive force (maximum point strength). At that time, the case where the double-sided adhesive gel sheet adhered to only one side of the aluminum substrate was judged as acceptable, and the case where the double-sided adhesive gel sheet was destroyed and was on both sides of the aluminum substrate was judged as unacceptable.

Adhesion (3);
Adhesive strength to plastics (adhesive strength measurement of adhesive gel sheet with adhesive on both sides)
The curable silicone gel composition was cured by press molding so as to have a length of 1.0 cm, a width of 2.5 cm, and a thickness of 2 mm to obtain a double-sided adhesive gel sheet. It was placed on a polycarbonate substrate 1 of 0 cm×2.5 cm wide×2.0 mm thick. After that, another polycarbonate substrate 1 was placed on the surface of the double-sided adhesive gel sheet 2 so that the adhesive area was 2.5 cm ² , and allowed to stand for 1 hour or more to prepare a test piece for shear adhesion test. After that, the shear force obtained by pulling the test piece in the shear direction at a measurement temperature of 23° C. at a tensile speed of 50 mm/min using a tensile shear adhesion tester was measured as the adhesive force (maximum point strength). At that time, the case where the double-sided adhesive gel sheet adhered to only one side of the polycarbonate substrate was judged as acceptable, and the case where the double-sided adhesive gel sheet was destroyed and both sides were on the polycarbonate substrate was judged as unacceptable.

[Loss factor (tan δ)]
The loss factor (tan δ) of the cured silicone gel used for the adhesive gel sheet was obtained by curing and measuring the uncured curable silicone gel composition under the following conditions.
Viscoelasticity measuring machine: UBM Co., Ltd. Rheogel-E4000
Measurement conditions: slit shear method (width: 13 mm, depth: 10 mm, interval: 0.25 mm)
Curing temperature: 80°C x 30 minutes Measurement temperature: 23°C
Strain control: 30 μm, 12%
Distorted waveform: sine wave

で示される２３℃での粘度が５，０００ｍＰａ・ｓの両末端ジメチルビニルシロキシ基封鎖ジメチルポリシロキサンを１００部と、エチニルメチルデシルカルビノール（任意成分）を０．０１部加え、室温（２３℃）にて均一になるまで攪拌した。その後、（Ｂ）成分である、２３℃での粘度が４０ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０１０２ｍｏｌ／ｇであるＭ^H単位とＱ単位をモル比；［Ｍ^H］／［Ｑ］＝１．６０で含有する三次元網状メチルハイドロジェンポリシロキサンを０．１４部、（Ｃ）成分である、下記式（５）

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンを５．７部加えて均一に混合したのち、（Ｄ）成分である、白金原子を１％含有する塩化白金酸ビニルシロキサン錯体のジメチルポリシロキサン溶液を０．０７部入れ、真空脱泡機にて脱気し、組成物１を得た。得られた組成物１を２３℃で２４時間硬化したところ、針入度６１の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．３５、Ｈ／Ｖｉ＝０．８５） [Example 1]
(A) component, the following formula (4)

100 parts of both end dimethylvinylsiloxy group-blocked dimethylpolysiloxane having a viscosity of 5,000 mPa s at 23 ° C. and 0.01 part of ethynylmethyldecylcarbinol (optional component) were added, and room temperature (23 ° C. ) until uniform. After that, the molar ratio of M ^H units and Q units, which are component (B), having a viscosity of 40 mPa s at 23 ° C. and a hydrogen atom (SiH group) amount bonded to a silicon atom (SiH group) of 0.0102 mol / g; 0.14 parts of three-dimensional network methylhydrogenpolysiloxane containing M ^H ]/[Q]=1.60;

5.7 parts of dimethylpolysiloxane blocked at both ends with dimethylhydrogensiloxy groups having a viscosity of 35 mPa s at 23° C. and a silicon-bonded hydrogen atom (SiH group) content of 0.00072 mol/g was added. Then, 0.07 parts of the dimethylpolysiloxane solution of the chloroplatinic acid vinylsiloxane complex containing 1% of platinum atoms, which is the component (D), is added, deaerated with a vacuum deaerator, and the composition is Got item 1. When the obtained composition 1 was cured at 23° C. for 24 hours, a cured product with a penetration of 61 was obtained.
((Hb/Hc)=0.35, H/Vi=0.85)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を４．８部とした以外は同様の方法にて調製し、組成物２を得た。得られた組成物２を２３℃で２４時間硬化したところ、針入度７６の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．４１、Ｈ／Ｖｉ＝０．７５） [Example 2]
In Example 1, the following formula (5), which is the component (C)

The amount of dimethylpolysiloxane endblocked with dimethylhydrogensiloxy groups at both ends and having a viscosity at 23° C. of 35 mPa·s and an amount of silicon-bonded hydrogen atoms (SiH groups) of 0.00072 mol/g was added to 4. A composition 2 was obtained in the same manner except that the amount was 8 parts. The resulting composition 2 was cured at 23° C. for 24 hours to obtain a cured product with a penetration of 76.
((Hb/Hc)=0.41, H/Vi=0.75)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を７．４部とした以外は同様の方法にて調製し、組成物３を得た。得られた組成物３を２３℃で２４時間硬化したところ、針入度３０の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．２７、Ｈ／Ｖｉ＝１．０４） [Example 3]
In Example 1, the following formula (5), which is the component (C)

The amount of dimethylpolysiloxane endblocked with dimethylhydrogensiloxy groups at both ends and having a viscosity of 35 mPa·s at 23° C. and an amount of silicon-bonded hydrogen atoms (SiH groups) of 0.00072 mol/g was added to 7. A composition 3 was obtained in the same manner except that 4 parts were used. When the obtained composition 3 was cured at 23° C. for 24 hours, a cured product with a penetration of 30 was obtained.
((Hb/Hc)=0.27, H/Vi=1.04)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンを除いた以外は同様の方法にて調製し、組成物４を得た。得られた組成物４を２３℃で２４時間硬化したところ、針入度５５の硬化物を得た。
（（Ｃ）成分非含有、Ｈ／Ｖｉ＝０．４７） [Comparative Example 1]
In Example 1, the component (B), which has a viscosity at 23° C. of 40 mPa s and a silicon-bonded hydrogen atom (SiH group) content of 0.0102 mol/g, is a mol of M ^H units and Q units. 0.30 parts of three-dimensional network methylhydrogenpolysiloxane contained at a ratio of [M ^H ]/[Q] = 1.60, and the following formula (5), which is the component (C),

The same except that dimethylpolysiloxane blocked at both ends with dimethylhydrogensiloxy groups having a viscosity of 35 mPa s at 23 ° C. and a silicon-bonded hydrogen atom (SiH group) content of 0.00072 mol / g was removed. to obtain composition 4. When the obtained composition 4 was cured at 23° C. for 24 hours, a cured product with a penetration of 55 was obtained.
((C) component not included, H/Vi=0.47)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を９．２部とした以外は同様の方法にて調製し、組成物５を得た。得られた組成物５を２３℃で２４時間硬化したところ、針入度５１の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．０８、Ｈ／Ｖｉ＝１．１０） [Comparative Example 2]
In Example 1, the component (B), which has a viscosity at 23° C. of 40 mPa s and a silicon-bonded hydrogen atom (SiH group) content of 0.0102 mol/g, is a mol of M ^H units and Q units. 0.05 part of the three-dimensional network methylhydrogenpolysiloxane contained at a ratio of [M ^H ]/[Q] = 1.60;

The amount of dimethylpolysiloxane blocked at both ends with dimethylhydrogensiloxy groups having a viscosity at 23° C. of 35 mPa·s and an amount of silicon-bonded hydrogen atoms (SiH groups) of 0.00072 mol/g was added to 9. A composition 5 was obtained by preparing in the same manner except that 2 parts were used. When the obtained composition 5 was cured at 23° C. for 24 hours, a cured product with a penetration of 51 was obtained.
((Hb/Hc)=0.08, H/Vi=1.10)

で示される２３℃での粘度が１００ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．００５４５ｍｏｌ／ｇである両末端トリメチルシロキシ基封鎖ジメチル・メチルハイドロジェンポリシロキサンを０．３０部用い、（Ｃ）成分である、下記式（５）

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を４．８部とした以外は同様の方法にて調製し、組成物６を得た。得られた組成物６を２３℃で２４時間硬化したところ、針入度６０の硬化物を得た。
（（Ｂ）成分非含有、Ｈ／Ｖｉ＝０．７８） [Comparative Example 3]
In Example 1, the component (B), which has a viscosity at 23° C. of 40 mPa s and a silicon-bonded hydrogen atom (SiH group) content of 0.0102 mol/g, is a mol of M ^H units and Q units. ratio: [M ^H ] / [Q] = 1.60 instead of three-dimensional network methylhydrogenpolysiloxane, the following formula (6)

0.30 of dimethyl-methylhydrogenpolysiloxane having both ends trimethylsiloxy group-blocked and having a viscosity at 23° C. of 100 mPa s and an amount of hydrogen atoms (SiH groups) bonded to silicon atoms of 0.00545 mol/g Formula (5) below, which is used as a component (C)

The amount of dimethylpolysiloxane endblocked with dimethylhydrogensiloxy groups at both ends and having a viscosity at 23° C. of 35 mPa·s and an amount of silicon-bonded hydrogen atoms (SiH groups) of 0.00072 mol/g was added to 4. A composition 6 was obtained by preparing in the same manner except that 8 parts were used. When the obtained composition 6 was cured at 23° C. for 24 hours, a cured product with a penetration of 60 was obtained.
((B) component not included, H/Vi=0.78)

で示される２３℃での粘度が１００ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．００５４５ｍｏｌ／ｇである両末端トリメチルシロキシ基封鎖ジメチル・メチルハイドロジェンポリシロキサンを０．５０部用い、（Ｃ）成分である、下記式（５）

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンを除いた以外は同様の方法にて調製し、組成物７を得た。得られた組成物７を２３℃で２４時間硬化したところ、未硬化であった。そこで８０℃×３０分にて硬化させたところ、針入度５１の硬化物を得た。
（（Ｂ）及び（Ｃ）成分非含有、Ｈ／Ｖｉ＝０．４２） [Comparative Example 4]
In Example 1, the component (B), which has a viscosity at 23° C. of 40 mPa s and a silicon-bonded hydrogen atom (SiH group) content of 0.0102 mol/g, is a mol of M ^H units and Q units. ratio: [M ^H ] / [Q] = 1.60 instead of three-dimensional network methylhydrogenpolysiloxane, the following formula (6)

0.50 of dimethyl-methylhydrogenpolysiloxane having both ends trimethylsiloxy group-blocked and having a viscosity at 23° C. of 100 mPa s and an amount of hydrogen atoms (SiH groups) bonded to silicon atoms of 0.00545 mol/g Formula (5) below, which is used as a component (C)

The same except that dimethylpolysiloxane blocked at both ends with dimethylhydrogensiloxy groups having a viscosity of 35 mPa s at 23 ° C. and a silicon-bonded hydrogen atom (SiH group) content of 0.00072 mol / g was removed. to obtain composition 7. When the obtained composition 7 was cured at 23° C. for 24 hours, it was uncured. Then, when it was cured at 80° C. for 30 minutes, a cured product with a penetration of 51 was obtained.
((B) and (C) components not included, H/Vi=0.42)

[Comparative Example 5]
In Example 1, 1.0 part of fumed silica (trade name: Aerosil R-972 (manufactured by Evonik)) having a BET specific surface area of about 130 m ² /g was added to the obtained composition 1, Composition 8 was obtained by dispersing and mixing. When the obtained composition 8 was cured at 23° C. for 24 hours, a cured product with a penetration of 63 was obtained.
((Hb/Hc)=0.35, H/Vi=0.85)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を８．３部とした以外は同様の方法にて調製し、組成物９を得た。得られた組成物９を２３℃で２４時間硬化したところ、針入度１９の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．２４、Ｈ／Ｖｉ＝１．１４） [Comparative Example 6]
In Example 1, the following formula (5), which is the component (C)

The amount of dimethylpolysiloxane endblocked with dimethylhydrogensiloxy groups at both ends and having a viscosity of 35 mPa·s at 23° C. and a silicon-bonded hydrogen atom (SiH group) content of 0.00072 mol/g was added to 8. A composition 9 was obtained by preparing in the same manner except that 3 parts were used. When the obtained composition 9 was cured at 23° C. for 24 hours, a cured product with a penetration of 19 was obtained.
((Hb/Hc)=0.24, H/Vi=1.14)

で示される２３℃での粘度が３５ｍＰａ・ｓ、ケイ素原子に結合した水素原子（ＳｉＨ基）量が０．０００７２ｍｏｌ／ｇである両末端ジメチルハイドロジェンシロキシ基封鎖ジメチルポリシロキサンの配合量を３．８部とした以外は同様の方法にて調製し、組成物１０を得た。得られた組成物１０を２３℃で２４時間硬化したところ、針入度９０の硬化物を得た。
（（Ｈｂ／Ｈｃ）＝０．５２、Ｈ／Ｖｉ＝０．６４） [Comparative Example 7]
In Example 1, the following formula (5), which is the component (C)

The amount of dimethylpolysiloxane endblocked with dimethylhydrogensiloxy groups at both ends and having a viscosity of 35 mPa·s at 23° C. and a silicon-bonded hydrogen atom (SiH group) content of 0.00072 mol/g was added to 3. A composition 10 was obtained by preparing in the same manner except that 8 parts were used. When the obtained composition 10 was cured at 23° C. for 24 hours, a cured product with a penetration of 90 was obtained.
((Hb/Hc)=0.52, H/Vi=0.64)

Single-sided and double-sided adhesive gel sheets were produced using the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 7, and the adhesive strength was measured as described above to determine acceptance. In addition, the penetration and loss factor (tan δ) of the cured products obtained by curing the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 7 were measured by the methods described above, and a pass/fail judgment was made. gone. 2 to 4 show the measurement results of the loss factor (tan δ) at 23° C. at a shear frequency of 0.1 to 50 Hz. Table 1 shows the results of these adhesive strength, penetration, and loss factor (tan δ). Table 1 also shows (Hb/Hc) and H/Vi of the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 7.

[evaluation]
The single-sided and double-sided adhesive gel sheets produced using the compositions obtained in Examples 1 to 3 satisfy the requirements of the present invention, and have a moderate adhesion maximum point strength to human skin. , and also shows excellent adhesive strength at the maximum point to metals and plastics. In addition, since the adhesive gel sheet (adhesive silicone gel layer) is not destroyed when peeled off, it is a very useful adhesive gel sheet that is easy to handle such as re-tensioning, reuse, and replacement work. I understand.

On the other hand, in Comparative Example 1, as the organohydrogenpolysiloxane, only the organohydrogenpolysiloxane having a three-dimensional network structure containing M ^H units and Q units as essential structural units, which are the component (B), was blended. , Component (C), which is a linear or branched chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms only at the ends of its molecular chains, is not added, so the cross-linking points are densely packed, and H /Vi deviates from the range of 0.47 and 0.6 to 1.5. With such a composition, when an adhesive gel sheet is produced, it becomes an adhesive gel sheet having a moderate adhesive maximum point strength on human skin, but it also deviates from the target loss factor (tan δ). Therefore, when the adhesive gel sheet is adhered to metal or plastic, the shear displacement results in destruction of the adhesive gel sheet. As a result, the adhesive gel sheet cannot be reused, and a step of peeling off the adhesive gel sheets attached to both sides is required when replacing the adhesive gel sheet.

In Comparative Example 2, SiH groups (Hb) of an organohydrogenpolysiloxane having a three-dimensional network structure containing M ^H units and Q units, which are components (B), and silicon atoms, which are components (C), The molar ratio of SiH groups (Hc) in the straight-chain or branched-chain methylhydrogenpolysiloxane having bonded hydrogen atoms only at the ends of the molecular chains is 0.08, and 0.10 ≤ (Hb/Hc) ≤ 1 outside the .50 range. Therefore, since the amount of the component (B), which serves as a cross-linking point, is small, the adhesive (adhesive silicone gel layer) of the adhesive gel sheet is destroyed and transferred to the skin when it is peeled off after being adhered to human skin. , become uncomfortable. Also, when the adhesive gel sheet is adhered to metal or plastic, shear displacement results in destruction of the adhesive gel sheet.

Comparative Example 3 uses a methylhydrogenpolysiloxane having SiH groups in side chains instead of the organohydrogenpolysiloxane having a three-dimensional network structure containing M ^H units and Q units as essential structural units, which is the component (B). is used. Even if an adhesive gel sheet is produced using such a composition, it is possible to obtain an adhesive ^gel sheet having an appropriate maximum point strength of adhesive force. Since the cross-linking points are more dense than when using an organohydrogenpolysiloxane with a three-dimensional network structure, it deviates from the target loss factor (tan δ) and becomes sticky when peeled off after being adhered to human skin. The adhesive (adhesive silicone gel layer) of the gel sheet is destroyed and migrates to the skin, and even when it is adhered to metal or plastic, the adhesive gel sheet is destroyed due to shear displacement. .

Comparative Example 4 uses, as the organohydrogenpolysiloxane, an organohydrogenpolysiloxane having a three-dimensional network structure containing M ^H units and Q units, which are components (B), and silicon atoms, which are components (C). It uses methylhydrogenpolysiloxane having SiH groups in side chains without blending linear or branched methylhydrogenpolysiloxane having hydrogen atoms bonded to only at the ends of the molecular chains. . When an adhesive gel sheet is produced using such a composition, H/Vi deviates from the range of 0.42 and 0.6 to 1.5, and is uncured at 23°C. Therefore, the adhesive gel sheet cannot be obtained without heating. In addition, even if an adhesive gel sheet is obtained by heating, the target loss factor (tan δ) is also deviated, so the maximum point strength of moderate adhesive force to human skin is low, and there is a possibility that it will peel off after application. Unsuitable due to high cost.

Comparative Example 5 is the result of producing an adhesive gel sheet using the composition of Example 1 with a filler added. It behaves as if it has become easily destroyed, and when it is peeled off after being adhered to human skin, the adhesive (adhesive silicone gel layer) of the adhesive gel sheet is destroyed and moves to the skin, causing discomfort. When the adhesive gel sheet was adhered to metal or plastic, the result was that the adhesive gel sheet was destroyed by shear displacement.

Comparative Examples 6 and 7 deviate from the target penetration range of 30-80. Therefore, in Comparative Example 6, the penetration is 19, that is, the adhesive silicone gel layer of the adhesive gel sheet is hard, and the target loss factor (tan δ) is also deviated. At the time of peeling, the adhesive strength does not reach the maximum point strength, and the possibility of peeling after sticking increases. On the contrary, in Comparative Example 7, since the penetration was 90, that is, the adhesive silicone gel layer of the adhesive gel sheet was too soft, the target loss factor (tan δ) was also deviated, and the adhesive was not adhered to human skin. When peeled off later, the adhesive (adhesive silicone gel layer) of the adhesive gel sheet is destroyed and transferred to the skin, causing discomfort.
From the above results, the effectiveness of the present invention can be confirmed.

Since the adhesive gel sheet of the present invention has particularly high surface adhesiveness of the adhesive silicone gel layer, it is difficult to peel off after the adhesive gel sheet is attached, and can be peeled off without destroying the adhesive silicone gel layer. Therefore, when used in medical and healthcare applications, by using an adhesive gel sheet with one side sticky, it is possible to prevent peeling over time by maintaining appropriate adhesiveness, and the adhesive silicone gel layer does not break when peeled off. No sticky silicone gel layer remains on the skin. In addition, there is no excessive peeling of the keratin of the skin when peeling it off, and there is no pain or discomfort caused by the pulling of body hair, or secondary inflammation caused by excessive irritation to the skin. It becomes a sticky gel sheet. In addition, adhesive gel sheets with adhesive on both sides are expected to be used for in-vehicle electronic parts, consumer electronic parts, and the like. When used in automotive electronic parts and consumer electronic parts, it facilitates the reuse and replacement of parts, leading to improved productivity and reduced waste. Therefore, the adhesive gel sheet of the present invention has the potential to be used in a wide range of fields.

1 base material 2 double-sided adhesive gel sheet

Claims (16)

Adhesive silicone consisting of a cured product of a curable silicone gel composition containing no filler and containing the following components (A) to (D) as essential components on one outer surface of a sheet-like or film-like substrate. A single-sided adhesive silicone gel sheet formed by laminating a gel layer, wherein the molar ratio (Hb/Hc) of SiH groups (Hb) in component (B) to SiH groups (Hc) in component (C) is 0.0. 10 to 1.50, and a cured silicone gel sheet having a penetration of 30 to 80 (according to JIS K2220).
(A) the following general formula (1)

(wherein R ¹ is a methyl group or a phenyl group, at least one of the two R ^1s in the same siloxane unit is a phenyl group, x is an integer of 150-800, y is a is an integer, and the arrangement of each parenthesized siloxane unit may be arbitrary.)
Linear organopolysiloxane having a silicon-bonded vinyl group at each end of the molecular chain and having a viscosity of 500 to 50,000 mPa s at 23° C.: 100 parts by mass,
(B) an organohydrogenpolysiloxane having a three-dimensional network structure containing (H(R) ₂ SiO _1/2 ) units and SiO _4/2 units as essential structural units (wherein R represents an aliphatic unsaturated bond; Indicates an unsubstituted or substituted monovalent hydrocarbon group that does not contain.): 0.01 to 10 parts by mass,
(C) the following general formula (2)

[In the formula, m is 0 or 1, n is an integer of 10 to 500, and the arrangement of each bracketed siloxane unit may be arbitrary. Z is a group represented by the following formula (3).

(Wherein, n is as described above.)]
Linear or branched chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms (SiH groups) only at the molecular chain terminals represented by: 0.1 to 50 parts by mass,
(D) addition reaction catalyst: effective amount 2. The single-sided adhesive silicone gel sheet according to claim 1, wherein the addition reaction catalyst of component (D) is a platinum group metal catalyst. The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl groups (Vi) in component (A) is 0.6 to 1.0. 5. The single-sided adhesive silicone gel sheet according to claim 1 or 2. The single-sided adhesive silicone gel sheet according to any one of claims 1 to 3, wherein the cured silicone gel has a loss factor (tan δ) at 23°C of 0.3 to 1.0 at a shear frequency of 0.1 to 50 Hz. . 5. The single-sided adhesive silicone gel sheet according to any one of claims 1 to 4, wherein the adhesive silicone gel layer has a maximum surface adhesive strength at 23°C of 1.0 to 10.0 gf/mm. The single-sided adhesive silicone gel sheet according to any one of claims 1 to 5, wherein the substrate is selected from plastic films, laminated films, nonwoven fabrics and cloth. The single-sided adhesive silicone gel sheet according to any one of claims 1 to 6, wherein the substrate has a thickness of 1 to 2,000 µm and the adhesive silicone gel layer has a thickness of 2 to 2,000 µm. 8. The adhesive silicone gel layer can be peeled off from the adhesive target substrate without breaking the adhesive silicone gel layer after the adhesive silicone gel layer is adhered to the adhesive target substrate. The single-sided adhesive silicone gel sheet according to item 1. A double-sided adhesive silicone gel sheet with a single-layer structure consisting of an adhesive silicone gel layer that is a cured product of a curable silicone gel composition that contains the following components (A) to (D) as essential components and does not contain a filler. and the molar ratio (Hb/Hc) of the SiH groups (Hb) in component (B) to the SiH groups (Hc) in component (C) is 0.10 to 1.50, and the silicone gel cured product A double-sided adhesive silicone gel sheet with a penetration (according to JIS K2220) of 30-80.
(A) the following general formula (1)

(wherein R ¹ is a methyl group or a phenyl group, at least one of the two R ^1s in the same siloxane unit is a phenyl group, x is an integer of 150-800, y is a is an integer, and the arrangement of each parenthesized siloxane unit may be arbitrary.)
Linear organopolysiloxane having a silicon-bonded vinyl group at each end of the molecular chain and having a viscosity of 500 to 50,000 mPa s at 23° C.: 100 parts by mass,
(B) an organohydrogenpolysiloxane having a three-dimensional network structure containing (H(R) ₂ SiO _1/2 ) units and SiO _4/2 units as essential structural units (wherein R represents an aliphatic unsaturated bond; Indicates an unsubstituted or substituted monovalent hydrocarbon group that does not contain.): 0.01 to 10 parts by mass,
(C) the following general formula (2)

[In the formula, m is 0 or 1, n is an integer of 10 to 500, and the arrangement of each bracketed siloxane unit may be arbitrary. Z is a group represented by the following formula (3).

(Wherein, n is as described above.)]
Linear or branched chain methylhydrogenpolysiloxane having silicon-bonded hydrogen atoms (SiH groups) only at the molecular chain terminals represented by: 0.1 to 50 parts by mass,
(D) addition reaction catalyst: effective amount 10. The double-sided adhesive silicone gel sheet according to claim 9, wherein the addition reaction catalyst of component (D) is a platinum group metal catalyst. The molar ratio (H/Vi) of the total (H) of hydrogen atoms bonded to silicon atoms in components (B) and (C) to the vinyl groups (Vi) in component (A) is 0.6 to 1.0. 11. The double-sided adhesive silicone gel sheet according to claim 9 or 10. The double-sided adhesive silicone gel sheet according to any one of claims 9 to 11, wherein the cured silicone gel has a loss factor (tan δ) at 23°C of 0.3 to 1.0 at a shear frequency of 0.1 to 50 Hz. . 13. The double-sided adhesive silicone gel sheet according to any one of claims 9 to 12, wherein the adhesive silicone gel layer has a maximum point strength of surface adhesive force at 23°C of 1.0 to 10.0 gf/mm. The double-sided adhesive silicone gel sheet according to any one of claims 9 to 13, having a thickness of 0.1 to 300 mm. 15. Both sides according to any one of claims 9 to 14, wherein the adhesive silicone gel layer can be peeled off without breaking the adhesive silicone gel layer when it is peeled from the adhesive target substrate after being adhered to the adhesive target substrate. Adhesive silicone gel sheet. An article using the single-sided adhesive or double-sided adhesive silicone gel sheet according to any one of claims 1 to 15.

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