JP2020015865A - Addition reaction curable silicone adhesive composition for applying to skin and adhesive tape for applying to skin - Google Patents

Abstract

To provide an addition reaction curable silicone adhesive composition for applying to skin which gives an adhesive layer having appropriate adhesive strength to the human skin and less deterioration of adhesive strength during re-applying and exhibiting excellent reworkability and durability.SOLUTION: There is provided an addition reaction curable silicone adhesive composition for applying to skin which comprises: (A) 55 to 95 pts.mass of a diorganopolysiloxane having two or more of alkenyl groups in one molecule; (B) an organopolysiloxane containing an RSiOunit, an SiOunit, a siloxane unit having a hydroxyl group and/or a siloxane unit having an alkoxy group having 1 to 6 carbon atoms in which the molar ratio of the RSiOunit/the SiOunit) is 0.5 to 1.5; (C) an organohydrogenpolysiloxane containing three or more Si-H groups in one molecule in an amount so that the molar ratio of (the Si-H group/the alkenyl group) is 0.5 to 3.0; and a platinum group metal-based catalyst.SELECTED DRAWING: None

Description

  The present invention is an addition-reaction-curable silicone for application to the skin, which has an appropriate adhesive strength to human skin, has a small decrease in adhesive strength due to reapplication, and provides an adhesive layer showing excellent reworkability and durability. The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape for sticking to skin using a cured product of the composition.

  The polysiloxane constituting the silicone pressure-sensitive adhesive has excellent heat resistance, cold resistance, weather resistance, electrical insulation, and chemical resistance because the main skeleton is composed of Si—O bonds having high binding energy. For this reason, they are used in severe environments such as heat-resistant tapes, electric insulating tapes, process masking tapes, and mica tapes having flame retardancy. Silicone pressure-sensitive adhesives are used for application to the skin because of their breathability and low irritation.

  For application to the skin, acrylic or rubber-based adhesives are often used. However, these adhesives have an excessively high adhesive force to an adherend such as the skin, so that the exfoliation of the skin is excessively exfoliated at the time of exfoliation, or the body hair is pulled, causing pain and discomfort, and further to the skin. Excessive irritation may cause secondary inflammation.

  In order to solve such problems, studies using a silicone pressure-sensitive adhesive for application to the skin have been advanced. In consideration of the adhesive properties at the time of sticking, it may be used by crosslinking using a peroxide or a platinum catalyst, or may be used without crosslinking (Patent Document 1: JP-A-3-200885). .

  However, when crosslinked by the method described above, although sufficient cohesive strength is obtained, the adhesive properties (tack, adhesive strength) inherent to the silicone adhesive are reduced, and the suitability of the adhesive for skin application is reduced. Sometimes. On the other hand, when the crosslinking is not performed, the cohesive force becomes insufficient, and the adhesive remains on the skin surface after peeling.

  In addition, as compared with acrylic or rubber-based adhesives, silicone adhesives have a feature that they are less likely to peel the body hair or the horny layer of the skin at the time of peeling, but they are not sufficient. For this reason, there is a problem that the adhesive strength is reduced when re-attaching after peeling. This is presumably because the adhesive surface is contaminated with keratin and body hair, and a component that inhibits adhesion remains between the adhesive surface and the skin when re-applied, resulting in a decrease in adhesive force.

  Silicone adhesives are used in medical tapes such as surgical tapes and dressing materials, and in such applications, there is temporary peeling for re-applying or observation, and it is not desirable that the adhesive strength is reduced by re-applying .

  In view of the above, there is a need for the development of a silicone adhesive for skin application that does not cause a decrease in adhesive force over time and has a small decrease in adhesive force due to reattachment, and is excellent in reworkability.

JP-A-3-200885

  The present invention has been made in view of the above circumstances, and has an appropriate adhesive strength to human skin, has a small decrease in adhesive strength when re-applied, and has an excellent reworkability and an adhesive layer exhibiting durability. An object of the present invention is to provide an addition reaction-curable silicone pressure-sensitive adhesive composition for skin application and a pressure-sensitive adhesive tape for skin using a cured product of the composition.

  The present inventors have conducted intensive studies to achieve the above object, and as a result, in the composition of the addition reaction-curable silicone pressure-sensitive adhesive composition, the Si-H group of the organohydrogenpolysiloxane relative to the alkenyl group of the diorganopolysiloxane By curing the silicone pressure-sensitive adhesive composition having a molar ratio of 0.5 to 3.0, the composition has an appropriate adhesive strength to human skin, and the adhesive strength decreases with time. It has been found that the adhesive layer does not occur, and that the adhesive layer is excellent in reworkability with little decrease in adhesive strength when re-attached, and the present invention has been accomplished.

（式中、Ｒ²は、同一又は異種の脂肪族不飽和結合を有さない炭素原子数１〜１０の１価炭化水素基であり、ａは０以上の整数、ｂは１以上の整数、ｃは０以上の整数、ｄは０以上の整数、ｅは０以上の整数、ｆは０以上の整数、ａ＋ｂ≧３であり、３≦ａ＋ｂ＋ｃ＋ｄ＋ｅ＋ｆ≦１，０００である。）
３．（Ｃ）成分の配合量が、（（Ｃ）成分中のＳｉ−Ｈ基／（Ａ）成分中のアルケニル基）のモル比が０．７５〜２．０となる量である１又は２に記載の皮膚貼付用付加反応硬化型シリコーン粘着剤組成物。
４．さらに、（Ｄ）成分として、付加反応制御剤を（Ａ）成分及び（Ｂ）成分の合計１００質量部に対して０．０５〜８質量部含有する１〜３のいずれかに記載の皮膚貼付用付加反応硬化型シリコーン粘着剤組成物。
５．基材と、この基材の少なくとも片面に、１〜４のいずれかに記載の皮膚貼付用付加反応硬化型シリコーン粘着剤組成物の硬化物からなる粘着剤層を有する皮膚貼付用粘着テープ。 Accordingly, the present invention provides the following addition reaction-curable silicone pressure-sensitive adhesive composition for skin application and an adhesive tape for skin application.
1. (A) a diorganopolysiloxane having two or more alkenyl groups in one molecule and having an alkenyl group content of 0.0005 mol / 100 g or more and less than 0.15 mol / 100 g: 55 to 95 parts by mass;
(B) R ¹ ₃ SiO _1/2 units (R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms the same or different.), A SiO ₂ units, a hydroxyl group bonded to a silicon atom containing siloxane units having the siloxane units and / or silicon atoms alkoxy group having 1 to 6 carbon atoms bonded to the molar ratio of (R ¹ ₃ SiO _1/2 units / SiO ₂ units) 0.5 a Organopolysiloxane having a molecular weight of 1.5 to 45 parts by mass (provided that the total of the components (A) and (B) is 100 parts by mass);
(C) An organohydrogenpolysiloxane having three or more Si-H groups in one molecule: the molar ratio of (Si-H group in component (C) / alkenyl group in component (A)) is 0.5. ~ 3.0,
(E) Platinum group metal-based catalyst: 1 to 5,000 ppm as platinum group metal on a mass basis relative to the total amount of components (A) and (B)
An addition-curable silicone pressure-sensitive adhesive composition for application to the skin, comprising:
2. (C) The addition-curable silicone pressure-sensitive adhesive composition for application to skin according to 1, wherein the component is an organohydrogenpolysiloxane represented by the following formula (1).

(Wherein, R ² is a monovalent hydrocarbon group having 1 to 10 carbon atoms having the same or different aliphatic unsaturated bonds, a is an integer of 0 or more, b is an integer of 1 or more, c is an integer of 0 or more, d is an integer of 0 or more, e is an integer of 0 or more, f is an integer of 0 or more, a + b ≧ 3, and 3 ≦ a + b + c + d + e + f ≦ 1,000.)
3. The amount of the component (C) is 1 or 2 in which the molar ratio of (Si—H group in the component (C) / alkenyl group in the component (A)) is 0.75 to 2.0. The addition reaction-curable silicone pressure-sensitive adhesive composition for applying to skin according to the above.
4. Furthermore, the skin patch according to any one of 1 to 3, wherein the addition reaction controlling agent is contained as a component (D) in an amount of 0.05 to 8 parts by mass based on a total of 100 parts by mass of the components (A) and (B). Reaction-curable silicone pressure-sensitive adhesive composition.
5. A pressure-sensitive adhesive tape for skin application comprising a substrate and an adhesive layer comprising a cured product of the addition-curable silicone pressure-sensitive adhesive composition for application to skin according to any one of 1 to 4 on at least one surface of the substrate.

  When the addition reaction-curable silicone pressure-sensitive adhesive composition for application to the skin of the present invention is used, it has an appropriate adhesive strength to human skin, and therefore, the substrate can be fixed to the skin. Furthermore, it is possible to provide an adhesive tape for skin that has a small decrease in adhesive strength when re-applied and is excellent in reworkability and durability.

（式中、Ｒ³は同一又は異種の炭素原子数１〜１０の１価炭化水素基であり、Ｒ³のうち少なくとも２つは炭素原子数２〜１０のアルケニル基含有有機基を含む。ｇは２以上の整数、ｈは１以上の整数、ｉは０以上の整数、ｊは０以上の整数で、１００≦ｇ＋ｈ＋ｉ＋ｊ≦２０，０００である。） Hereinafter, the present invention will be described in detail. Hereinafter, the “addition reaction-curable silicone pressure-sensitive adhesive composition for application to the skin” may be simply referred to as “silicone pressure-sensitive adhesive composition”.
<(A) component>
(A) a diorganopolysiloxane having two or more alkenyl groups in one molecule and having an alkenyl group content of 0.0005 mol / 100 g or more and less than 0.15 mol / 100 g; May be used in combination of two or more. For example, one represented by the following formula (2) can be exemplified.

(Wherein, R ³ is the same or different and is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and at least two of R ³ include an alkenyl group-containing organic group having 2 to 10 carbon atoms. G Is an integer of 2 or more, h is an integer of 1 or more, i is an integer of 0 or more, j is an integer of 0 or more, and 100 ≦ g + h + i + j ≦ 20,000.)

In the above formula, R ³ is the same or different and is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and at least two of R ³ include an alkenyl group-containing organic group having 2 to 10 carbon atoms. Examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, a cycloalkyl group such as a cyclohexyl group, and an aryl group such as a phenyl group. Further, some or all of the hydrogen atoms bonded to carbon atoms of these groups may be substituted with halogen atoms or other groups, and examples of the substituent include a trifluoromethyl group, Examples thereof include a fluoropropyl group. Among them, a saturated aliphatic group or aromatic group is preferable, and a methyl group and a phenyl group are preferable. When R ³ contains a phenyl group, the content of the phenyl group is preferably 0.1 to 30 mol% of all organic groups bonded to silicon atoms of the diorganopolysiloxane of the formula (2). When this content exceeds 30 mol%, the adhesive strength of the obtained pressure-sensitive adhesive layer to human skin may decrease.

  The alkenyl group-containing organic group is preferably an organic group having 2 to 10 carbon atoms, for example, an alkenyl group such as a vinyl group, an allyl group, a hexenyl group, an octenyl group, an acryloylpropyl group, an acryloylmethyl group, and a methacryloylpropyl group. Examples thereof include an acryloylalkyl group, a methacryloylalkyl group, a cycloalkenylalkyl group such as cyclohexenylethyl group, and an alkenyloxyalkyl group such as vinyloxypropyl group. Among them, a vinyl group is preferable from an industrial viewpoint.

  The amount of the alkenyl group contained in the component (A) is 0.0005 mol / 100 g or more and less than 0.15 mol / 100 g per 100 g of the organopolysiloxane, and is 0.0007-0. 13 mol is preferable, and 0.001 to 0.10 mol is more preferable. If the amount is less than 0.0005 mol, the curability may decrease or the holding power may decrease. When the amount is less than 0.15 mol, the obtained pressure-sensitive adhesive layer does not become hard, and an appropriate pressure-sensitive adhesive strength and tack can be obtained. The measurement of the amount of the alkenyl group is performed by an iodine value method (such as the Hanus method).

  g is an integer of 2 or more, h is an integer of 1 or more, i is an integer of 0 or more, j is an integer of 0 or more, 100 ≦ g + h + i + j ≦ 20,000, and preferably 150 ≦ g + h + i + j ≦ 15,000. If g + h + i + j is less than 100, the reactivity may decrease due to too many cross-linking points, and if it exceeds 20,000, the viscosity of the composition becomes extremely high, so that it becomes difficult to stir and mix. May be worse.

  The component (A) is usually produced by subjecting a cyclic low-molecular siloxane such as octamethylcyclotetrasiloxane to ring-opening polymerization using a catalyst, but contains a low-molecular cyclic siloxane as a raw material after polymerization. It is preferable to use a mixture obtained by distilling this under heating and reduced pressure while passing an inert gas through the reaction product.

  Further, the amount of the hydroxyl group (Si-OH group) bonded to the silicon atom contained in the component (A) is preferably 0 to 0.45% by mass and 0 to 0.40% by mass in the component (A). . The measurement of the amount of SiOH groups can be usually determined by a known method such as a Grignard method or an NMR method (the same applies hereinafter).

  The property of the diorganopolysiloxane of the component (A) may be oily or raw rubber. The viscosity of the component (A) at 25 ° C is preferably from 1,000 to 1,000,000 mPa · s, more preferably from 5,000 to 800,000 mPa · s, if it is oily. In the case of raw rubber, the viscosity of a solution dissolved in toluene is preferably from 1,000 to 100,000 mPa · s, and more preferably from 3,000 to 80,000 mPa · s, so as to have a concentration of 30% by mass. If the viscosity is less than the lower limit, the curability of the pressure-sensitive adhesive composition may decrease, or the holding power may decrease.If the viscosity exceeds the upper limit, the pressure-sensitive adhesive composition becomes too high in viscosity. Sometimes stirring becomes difficult. In this specification, the viscosity is a value measured at 25 ° C. using a BM-type rotational viscometer (the same applies hereinafter).

（１００≦ｚ１≦５，０００）

（１００≦ｚ２≦１５，０００）

（１００≦ｚ３≦１９，９９８、２≦ｚ４≦２，０００、１０２≦ｚ３＋ｚ４≦２０，０００）

（１００≦ｚ５≦１９，９９８、２≦ｚ６≦２，０００、１０２≦ｚ５＋ｚ６≦２０，０００）

（１００≦ｚ７≦１９，９９９、１≦ｚ８≦２，０００、１０１≦ｚ７＋ｚ８≦２０，０００）

（１００≦ｚ９≦１９，９９８、１≦ｚ１０≦６，０００、１≦ｚ１１≦３，０００、１０２≦ｚ９＋ｚ１０＋ｚ１１≦２０，０００） Specific examples of the component (A) include, but are not limited to, the following. Me, Vi, and Ph in the following formulas represent a methyl group, a vinyl group, and a phenyl group, respectively.

(100 ≦ z1 ≦ 5,000)

(100 ≦ z2 ≦ 15,000)

(100 ≦ z3 ≦ 19,998, 2 ≦ z4 ≦ 2,000, 102 ≦ z3 + z4 ≦ 20,000)

(100 ≦ z5 ≦ 19,998, 2 ≦ z6 ≦ 2,000, 102 ≦ z5 + z6 ≦ 20,000)

(100 ≦ z7 ≦ 19,999, 1 ≦ z8 ≦ 2,000, 101 ≦ z7 + z8 ≦ 20,000)

(100 ≦ z9 ≦ 19,998, 1 ≦ z10 ≦ 6,000, 1 ≦ z11 ≦ 3,000, 102 ≦ z9 + z10 + z11 ≦ 20,000)

<(B) component>
Component (B), R ¹ ₃ SiO _1/2 units (R ¹ is a monovalent hydrocarbon group having a carbon number of 1 to 10 identical or different.), A SiO ₂ units, silicon-bonded containing siloxane units having the siloxane units and / or silicon atoms alkoxy group having 1 to 6 carbon atoms bonded to a hydroxyl group, the molar ratio of (R ¹ ₃ SiO _1/2 units / SiO ₂ units) The organopolysiloxane is 0.5 to 1.5, and can be used alone or in combination of two or more.

R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group; a cycloalkyl group such as a cyclohexyl group; Alkyl group; aryl group such as phenyl group; alkenyl group such as vinyl group, allyl group and hexenyl group. Among them, a methyl group is preferable. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group.

The molar ratio of the (R ¹ ₃ SiO _1/2 units / SiO ₂ units) is from 0.5 to 1.5, preferably 0.6 to 1.3. When the molar ratio is less than 0.5, the adhesive strength and tack of the obtained pressure-sensitive adhesive layer decrease. On the other hand, when it exceeds 1.5, the adhesive strength and the holding power of the obtained pressure-sensitive adhesive layer decrease.

(B) component, but it is an essential R ¹ ₃ SiO _1/2 units and SiO ₂ units, in a range not impairing the characteristics of the present invention, R ¹ SiO _1.5 units and R ¹ ₂ SiO units (R ¹ is as described above), or both may be contained in the component (B). Incidentally, in the component (B), the total content of R ¹ ₃ SiO _1/2 units and SiO ₂ units, although the characteristics of the present invention is not particularly limited as long as intact, (B) the total siloxane units of component , Preferably 80 to 100 mol%, more preferably 90 to 100 mol%.

The component (B) includes a siloxane unit having a hydroxyl group bonded to a silicon atom (silanol group-containing unit) and / or a siloxane unit having an alkoxy group having 1 to 6 carbon atoms bonded to a silicon atom (alkoxy group-containing unit). The amount of the silanol group-containing unit is preferably from 0.1 to 5% by mass, more preferably from 0.2 to 4% by mass, of the hydroxyl group content in the component (B). When the hydroxyl group content exceeds 5% by mass, the tackiness of the obtained silicone pressure-sensitive adhesive layer may decrease, or the curability may decrease. When the hydroxyl group content is less than 0.1% by mass, the condensation reaction between the components (B) and the component (A) described below and the condensation reaction with the component (C) during curing become insufficient, and the adhesive strength is reduced. There is a risk. Further, the amount of the alkoxy group-containing unit is preferably such that the content of the alkoxy group is 10% by mass or less, preferably 0 to 8% by mass of the component (B). When the alkoxy group content exceeds 10% by mass, the tackiness of the obtained silicone pressure-sensitive adhesive layer may decrease, or the curability may decrease. Furthermore, the total amount of the silanol group-containing unit and the alkoxy group-containing unit is preferably from 0.1 to 12% by mass in the component (B), and more preferably from 0.2 to 10%, as the total of the hydroxyl group content and the alkoxy group content. % Is more preferred. Here, the silanol group-containing _{^{units, R 1 2 (HO) SiO}} 1/2 _{^{units, R 1 (HO) 2 SiO}} 1/2 units, R ¹ (HO) SiO units, (HO) SiO _3/2 units, etc. Can be exemplified. Further, the alkoxy group-containing _{^{units, R 1 2 (R'O) SiO}} 1/2 _{^{units, R 1 (R'O) 2 SiO}} 1/2 units, R ¹ (R'O) SiO units, (R ' O) SiO3 _{/ 2} units (R'O is the same or different and is an alkoxy group having 1 to 6 carbon atoms, and those exemplified above) can be exemplified.

  The component (B) preferably has a weight average molecular weight of 500 to 10,000, more preferably 1,000 to 8,000. The weight average molecular weight can be determined as a polystyrene equivalent weight average molecular weight in gel permeation chromatography (GPC) analysis using toluene as a developing solvent (the same applies hereinafter).

<(A) and (B) components>
Since the component (A) is 55 to 95 parts by mass and the component (B) is 5 to 45 parts by mass, the mixing ratio of the components (A) and (B) is (A) / (B) = 55 by mass ratio. / 45 to 95/5, preferably 60/40 to 90/10, more preferably 65/35 to 85/15. When the compounding ratio is less than 55/45, the reworkability of the obtained silicone pressure-sensitive adhesive layer is reduced. On the other hand, when it exceeds 95/5, the adhesive strength of the obtained silicone pressure-sensitive adhesive layer becomes insufficient.

<(C) component>
The component (C) is an organohydrogenpolysiloxane having three or more Si-H groups in one molecule, and can be used alone or in an appropriate combination of two or more. The number of Si-H groups in one molecule is 3 or more, preferably 5 to 1,000, and more preferably 8 to 500. The organohydrogenpolysiloxane of the component (C) may be linear, branched or cyclic. This organohydrogenpolysiloxane preferably has a viscosity at 25 ° C. of 1 to 5,000 mPa · s, more preferably 2 to 3,000 mPa · s.

（式中、Ｒ²は、同一又は異種の脂肪族不飽和結合を有さない炭素原子数１〜１０の１価炭化水素基であり、ａは０以上の整数、ｂは１以上の整数、ｃは０以上の整数、ｄは０以上の整数、ｅは０以上の整数、ｆは０以上の整数、ａ＋ｂ≧３であり、３≦ａ＋ｂ＋ｃ＋ｄ＋ｅ＋ｆ≦１，０００である。） Examples of the organohydrogenpolysiloxane of the component (C) include those represented by the following formula (1).

(Wherein, R ² is a monovalent hydrocarbon group having 1 to 10 carbon atoms having the same or different aliphatic unsaturated bonds, a is an integer of 0 or more, b is an integer of 1 or more, c is an integer of 0 or more, d is an integer of 0 or more, e is an integer of 0 or more, f is an integer of 0 or more, a + b ≧ 3, and 3 ≦ a + b + c + d + e + f ≦ 1,000.)

Here, R ² is the same or different, from 1 to 10 carbon atoms free of aliphatic unsaturation, preferably 1-8 monovalent hydrocarbon group, as R ² include a methyl group, ethyl Groups, alkyl groups such as propyl group and butyl group, cycloalkyl groups such as cyclohexyl group, and aryl groups such as phenyl group and tolyl group. Further, some or all of the hydrogen atoms bonded to carbon atoms of these groups may be substituted with halogen atoms or other groups, and examples of the substituent include a trifluoromethyl group, Examples thereof include a fluoropropyl group. Among them, a saturated aliphatic group or aromatic group is preferable, and a methyl group or a phenyl group is more preferable. Particularly, a methyl group is preferable.

  a is an integer of 0 or more, b is an integer of 1 or more, c is an integer of 0 or more, d is an integer of 0 or more, e is an integer of 0 or more, f is an integer of 0 or more, a + b ≧ 3, and 3 ≦ a + b + c + d + e + f ≦ 1,000, preferably 5 ≦ a + b + c + d + e + f ≦ 1,000.

（３≦ｚ１２≦１，０００）

（３≦ｚ１３≦９９９、１≦ｚ１４≦９９７、４≦ｚ１３＋ｚ１４≦１，０００）

（１≦ｚ１５≦９９９、１≦ｚ１６≦９９９、２≦ｚ１５＋ｚ１６≦１，０００）

（３≦ｚ１７≦９９８、１≦ｚ１８≦９９６、１≦ｚ１９≦９９６、５≦ｚ１７＋ｚ１８＋ｚ１９≦１，０００）

（０≦ｚ２０≦２００、０≦ｚ２１≦２００、０≦ｚ２２≦２００、１≦ｚ２３≦５０、３≦ｚ２０＋ｚ２１＋（（ｚ２２＋２）×ｚ２３）≦１，０００） Specific examples of the component (C) include, but are not limited to, the following. Me and Ph in the following formulas represent a methyl group and a phenyl group, respectively.

(3 ≦ z12 ≦ 1,000)

(3 ≦ z13 ≦ 999, 1 ≦ z14 ≦ 997, 4 ≦ z13 + z14 ≦ 1,000)

(1 ≦ z15 ≦ 999, 1 ≦ z16 ≦ 999, 2 ≦ z15 + z16 ≦ 1,000)

(3 ≦ z17 ≦ 998, 1 ≦ z18 ≦ 996, 1 ≦ z19 ≦ 996, 5 ≦ z17 + z18 + z19 ≦ 1,000)

(0 ≦ z20 ≦ 200, 0 ≦ z21 ≦ 200, 0 ≦ z22 ≦ 200, 1 ≦ z23 ≦ 50, 3 ≦ z20 + z21 + ((z22 + 2) × z23) ≦ 1,000)

  The compounding amount of the component (C) is determined by the molar ratio of the Si—H group in the component (C) to the alkenyl group in the component (A) (Si—H group in the component (C) / (A) in the component (A)). (Alkenyl group) The amount is 0.5 to 3.0, more preferably 0.6 to 2.5, and even more preferably 0.75 to 2.0. When the molar ratio is less than 0.5, the adhesive strength to the skin cannot be obtained, the crosslinking density in the cured product of the obtained silicone pressure-sensitive adhesive composition becomes low, and the cohesive strength is insufficient. On the other hand, if the molar ratio exceeds 3.0, the adhesive properties (tack, adhesive strength) inherently possessed by the silicone pressure-sensitive adhesive are lowered, and the suitability as a pressure-sensitive adhesive for skin application is lowered.

  It is presumed that the hardness of the pressure-sensitive adhesive layer affects the reworkability of the pressure-sensitive adhesive layer obtained from the usual addition reaction-curable silicone pressure-sensitive adhesive composition. If the pressure-sensitive adhesive layer is soft, the pressure-sensitive adhesive layer is deformed when the pressure-sensitive adhesive tape is peeled off the skin, and the lifting of the skin is suppressed. As a result, the surface of the pressure-sensitive adhesive is not contaminated by keratin or body hair, and the adhesive strength does not decrease when re-applied. On the other hand, if the pressure-sensitive adhesive layer is hard, when the pressure-sensitive adhesive tape is peeled off from the skin, the skin is lifted, so that irritation to the skin is increased, exfoliating keratin and body hair and contaminating the surface of the pressure-sensitive adhesive. In the present invention, by adjusting the ratio of the component (A) to the component (B) and the amount of the component (C), the silicone adhesive becomes soft and has cohesive strength, and reworkability can be obtained. Furthermore, since the adhesive is soft, it easily follows the uneven structure of the skin, and thus has excellent skin wettability.

  Here, in the silicone pressure-sensitive adhesive composition of the present invention, the total amount of Si-OH groups in the composition (for example, the total amount of Si-H groups based on the total amount of Si-OH groups in components (A) and (B)) Is preferably from 0.02 to 200,000, more preferably from 0.1 to 100,000.The above components (A) and (B) When the condensation reaction product is subjected to a condensation reaction together to obtain a condensation reaction product, the molar ratio of the total amount of Si—H groups to the amount of Si—OH groups (Si—H group / Si—OH group) is 0.05 to 200, 000 is preferable, and 0.1 to 100,000 is more preferable.

<(D) component>
The silicone pressure-sensitive adhesive composition of the present invention may further contain (D) an addition reaction control agent. (D) The addition reaction controlling agent can be used alone or in an appropriate combination of two or more. The addition reaction control agent is used before the heat curing, for example, during the preparation of the silicone pressure-sensitive adhesive composition or during the application of the silicone pressure-sensitive adhesive composition to the substrate, the treatment liquid containing the silicone pressure-sensitive adhesive composition increases the viscosity. Alternatively, it is an optional component that can be added to prevent gelation from occurring.

  Specific examples of the component (D) include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, Ethynylcyclohexanol, 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1 -Trimethylsiloxycyclohexane, bis (2,2-dimethyl-3-butynoxy) dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3 , 3-tetramethyl-1,3-divinyldisiloxane and the like.

  The compounding amount of the component (D) is in the range of 0 to 8 parts by mass with respect to 100 parts by mass of the total of the components (A) and (B). More preferably, it is in the range of 0.1 to 5 parts by mass. If the amount of the component (D) exceeds 8 parts by mass, the curability of the obtained composition may be reduced.

<(E) component>
The component (E) is a platinum group metal-based catalyst, and can be used alone or in an appropriate combination of two or more. Examples of the platinum group metal-based catalyst include chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reactant of chloroplatinic acid and an alcohol, a reactant of chloroplatinic acid and an olefin compound, and a chloroplatinic acid and a vinyl-containing siloxane. Examples include a reactant, a platinum-based catalyst such as a complex of platinum and a vinyl group-containing siloxane, and a catalyst containing a metal such as ruthenium, rhodium, palladium, and iridium. In the present invention, among these, a platinum catalyst is preferable.

  The addition amount of the component (E) is 1 to 5,000 ppm, preferably 5 to 500 ppm, more preferably 10 to 200 ppm as a platinum group metal component on a mass basis with respect to the total of the components (A) and (B). . If it is less than 1 ppm, the curability is reduced, the crosslinking density is reduced, and the holding power is reduced. If it exceeds 5,000 ppm, the usable time of the treatment bath is shortened.

<Other optional ingredients>
In the silicone pressure-sensitive adhesive composition of the present invention, optional components can be added in addition to the above components. For example, non-reactive organopolysiloxanes such as polydimethylsiloxane and polydimethyldiphenylsiloxane; phenol-based, quinone-based, amine-based, phosphorus-based, phosphite-based, sulfur-based, and thioether-based antioxidants; Benzophenone-based light stabilizers; Phosphate ester-based, halogen-based, phosphorus-based, antimony-based flame retardants; Cationic activators, anionic activators, nonionic activators, and other antistatic agents; As the solvent for lowering, aromatic hydrocarbon solvents such as toluene and xylene, hexane, heptane, octane, isooctane, decane, aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, isoparaffin, industrial gasoline, petroleum benzine, Hydrocarbon solvents such as solvent naphtha, acetone, methyl Ketone solvents such as tyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonylacetone, cyclohexanone, ethyl acetate, propyl acetate, isopropyl acetate, and acetic acid Ester solvents such as butyl and isobutyl acetate; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane and 1,4-dioxane; 2-methoxyethyl acetate; Solvents having an ester and ether moiety, such as ethoxyethyl acetate, propylene glycol monomethyl ether acetate, and 2-butoxyethyl acetate, hexamethyldisiloxane, octamethyltrisiloxane, Le cyclotetrasiloxane, decamethylcyclopentasiloxane, tris (trimethylsiloxy) methylsilane, tetrakis (trimethylsiloxy) siloxane solvents such as silane, or a mixed solvent thereof; dyes; pigments and the like can be used. These can be used alone or in combination of two or more.

<Method for producing and using silicone pressure-sensitive adhesive composition>
In the silicone pressure-sensitive adhesive composition, for example, from the viewpoint of pot life, components excluding component (E) (components (A), (B) and (C), and if necessary, component (D) and optional components) Before mixing and using the silicone pressure-sensitive adhesive composition (coating on an object), the component (D) is blended with the silicone pressure-sensitive adhesive composition and uniformly mixed.

<Use of composition>
The silicone pressure-sensitive adhesive layer can be obtained by applying the addition reaction-curable silicone pressure-sensitive adhesive composition of the present invention produced as described above to various substrates and curing it under predetermined conditions.

<Adhesive tape for attaching to skin>
For example, it can be suitably used as a pressure-sensitive adhesive tape for skin application having a substrate and an adhesive layer comprising a cured product of an addition-curable silicone pressure-sensitive adhesive composition for skin application on at least one surface of the substrate.

  As the base material, a plastic film made of paper or plastic, glass, metal, cloth, or the like is selected. Examples of the paper include high quality paper, coated paper, art paper, glassine paper, polyethylene laminated paper, kraft paper, Japanese paper, and synthetic paper. As plastic films, polyethylene films, polypropylene films, polyester films, polyimide films, polyamide films, polyurethane films, polyurea films, polyvinyl chloride films, polyvinylidene chloride films, polyvinyl alcohol films, polycarbonate films, polytetrafluoroethylene films, Examples include a polystyrene film, an ethylene-vinyl acetate copolymer film, an ethylene-vinyl alcohol copolymer film, a triacetyl cellulose film, a polyether ether ketone film, and a polyphenylene sulfide film. There is no particular limitation on the thickness and type of glass, and glass may be subjected to a chemical strengthening treatment or the like. Glass fiber can also be used, and the glass fiber may be used alone or in combination with another resin. Examples of the metal include an aluminum foil, a copper foil, a gold foil, a silver foil, and a nickel foil.

  In order to further improve the adhesion between these substrates and the silicone pressure-sensitive adhesive layer, a substrate that has been subjected to a primer treatment, a corona treatment, an etching treatment, or a plasma treatment may be used.

  The coating method may be a known coating method, such as a comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, bar coater, kiss coater, gravure coater, screen coating. Coating, dip coating, cast coating and the like. When applying, the mixture may be appropriately diluted with the solvent described in the above optional component. In this case, a 20 to 60% by mass solution of the silicone pressure-sensitive adhesive composition can be used.

  The coating amount is appropriately set depending on the application, but usually, the amount is preferably such that the thickness of the cured silicone pressure-sensitive adhesive layer is from 2 to 2,000 μm, particularly from 3 to 1,000 μm.

  The addition reaction-curable silicone pressure-sensitive adhesive composition may be cured at 70 to 250 ° C. for 10 seconds to 10 minutes, but is not limited thereto.

  The pressure-sensitive adhesive tape of the present invention may be produced by directly applying the addition reaction-curable silicone pressure-sensitive adhesive composition of the present invention to a substrate as described above, and curing to form a silicone pressure-sensitive adhesive layer, The composition may be applied to a release film or a release paper on which a release coating has been applied and cured to form a silicone pressure-sensitive adhesive layer. Good.

  Hereinafter, the present invention will be described specifically with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. In each of the examples, the viscosity is a value at 25 ° C., parts are parts by mass, ratios indicate mass ratios, and characteristic values indicate values measured by the following test methods. In each example, Me represents a methyl group, and Vi represents a vinyl group.

（式中、ｇ及びｈは上記の粘度及びビニル基量を満たす数である。）
で示されるジメチルポリシロキサン（ケイ素原子結合水酸基（Ｓｉ−ＯＨ基）量０．００７質量％）（９０．０部）、（Ｂ）成分として、（Ｂ−１）Ｍｅ₃ＳｉＯ_1/2単位、ＳｉＯ₂単位及びケイ素原子に結合した水酸基を有するシロキサン単位からなるポリシロキサン（Ｍｅ₃ＳｉＯ_1/2単位／ＳｉＯ₂単位（モル比）＝０．８０、ケイ素原子結合水酸基含有量１．２質量％、重量平均分子量４，０００）（１０．０部）、Ｎ−ヘプタン（６５．６部）、及び（Ｄ）エチニルシクロヘキサノール（０．２部）からなる溶液を室温（２５℃、以下同じ）で１２時間攪拌して、固形分が約６０質量％のシリコーン粘着剤ベース組成物Ｉを合成した。 [Synthesis Example 1]
As the component (A), the viscosity when dissolved in toluene so that the concentration of the component (A-1) becomes 30% by mass is 4,000 mPa · s, and both ends of the molecular chain are blocked with vinyl groups, and 0.002 mol / The following formula having a vinyl group content of 100 g

(In the formula, g and h are numbers satisfying the above-mentioned viscosity and vinyl group content.)
(A silicon atom-bonded hydroxyl group (Si-OH group) amount of 0.007 mass%) (90.0 parts), (B-1) Me ₃ SiO _1/2 unit as a component (B), Polysiloxane consisting of SiO ₂ units and siloxane units having hydroxyl groups bonded to silicon atoms (Me ₃ SiO _1/2 units / SiO ₂ units (molar ratio) = 0.80, silicon atom-bonded hydroxyl group content 1.2% by mass , Weight-average molecular weight 4,000) (10.0 parts), N-heptane (65.6 parts), and (D) ethynylcyclohexanol (0.2 part) at room temperature (25 ° C, the same applies hereinafter). For 12 hours to synthesize a silicone pressure-sensitive adhesive base composition I having a solid content of about 60% by mass.

（式中、ｇ及びｈは上記の粘度及びビニル基量を満たす数である。）
で示されるジメチルポリシロキサン（ケイ素原子結合水酸基（Ｓｉ−ＯＨ基）量０．００７質量％）（７０．０部）、（Ｂ）成分として、（Ｂ−１）Ｍｅ₃ＳｉＯ_1/2単位、ＳｉＯ₂単位及びケイ素原子に結合した水酸基を有するシロキサン単位からなるポリシロキサン（Ｍｅ₃ＳｉＯ_1/2単位／ＳｉＯ₂単位（モル比）＝０．８０、ケイ素原子結合水酸基含有量１．２質量％、重量平均分子量４，０００）（３０．０部）、Ｎ−ヘプタン（６５．６部）、及び（Ｄ）エチニルシクロヘキサノール（０．２部）からなる溶液を室温（２５℃、以下同じ）で１２時間攪拌して、固形分が約６０質量％のシリコーン粘着剤ベース組成物ＩＩを合成した。 [Synthesis Example 2]
As the component (A), the viscosity when dissolved in toluene so that the concentration of the component (A-1) becomes 30% by mass is 4,000 mPa · s, and both ends of the molecular chain are blocked with vinyl groups, and 0.002 mol / The following formula having a vinyl group content of 100 g

(In the formula, g and h are numbers satisfying the above-mentioned viscosity and vinyl group content.)
(Amount of silicon atom-bonded hydroxyl group (Si-OH group) 0.007% by mass) (70.0 parts), (B-1) Me ₃ SiO _1/2 unit as component (B), Polysiloxane consisting of SiO ₂ units and siloxane units having hydroxyl groups bonded to silicon atoms (Me ₃ SiO _1/2 units / SiO ₂ units (molar ratio) = 0.80, silicon atom-bonded hydroxyl group content 1.2% by mass , Weight average molecular weight 4,000) (30.0 parts), N-heptane (65.6 parts), and (D) ethynylcyclohexanol (0.2 part) at room temperature (25 ° C., the same applies hereinafter). For 12 hours to synthesize a silicone pressure-sensitive adhesive base composition II having a solid content of about 60% by mass.

（式中、ｇ及びｈは上記の粘度及びビニル基量を満たす数である。）
で示されるジメチルポリシロキサン（ケイ素原子結合水酸基（Ｓｉ−ＯＨ基）量０．００７質量％）（４０．０部）、（Ｂ）成分として、（Ｂ−１）Ｍｅ₃ＳｉＯ_1/2単位、ＳｉＯ₂単位及びケイ素原子に結合した水酸基を有するシロキサン単位からなるポリシロキサン（Ｍｅ₃ＳｉＯ_1/2単位／ＳｉＯ₂単位（モル比）＝０．８０、ケイ素原子結合水酸基含有量１．２質量％、重量平均分子量４，０００）（６０．０部）、Ｎ−ヘプタン（６５．６部）、及び（Ｄ）エチニルシクロヘキサノール（０．２部）からなる溶液を室温（２５℃、以下同じ）で１２時間攪拌して、固形分が約６０質量％のシリコーン粘着剤ベース組成物ＩＩＩを合成した。 [Synthesis Example 3]
As the component (A), the viscosity when dissolved in toluene so that the concentration of the component (A-1) becomes 30% by mass is 4,000 mPa · s, and both ends of the molecular chain are blocked with vinyl groups, and 0.002 mol / The following formula having a vinyl group content of 100 g

(In the formula, g and h are numbers satisfying the above-mentioned viscosity and vinyl group content.)
(Amount of silicon-bonded hydroxyl group (Si-OH group) 0.007% by mass) (40.0 parts), (B-1) Me ₃ SiO _1/2 unit as component (B), Polysiloxane consisting of SiO ₂ units and siloxane units having hydroxyl groups bonded to silicon atoms (Me ₃ SiO _1/2 units / SiO ₂ units (molar ratio) = 0.80, silicon atom-bonded hydroxyl group content 1.2% by mass , Weight-average molecular weight 4,000) (60.0 parts), N-heptane (65.6 parts), and (D) ethynylcyclohexanol (0.2 part) at room temperature (25 ° C, the same applies hereinafter). For 12 hours to synthesize a silicone pressure-sensitive adhesive base composition III having a solid content of about 60% by mass.

<Raw materials>
(C) Component (C-1)
Methyl hydrogen polysiloxane represented by the following formula

(C-2)
Methyl hydrogen polysiloxane represented by the following formula

(E) Component Platinum and siloxane complex containing vinyl group (containing 0.5% by mass as platinum content)

[Examples 1 to 6, Comparative Examples 1 to 4]
The silicone pressure-sensitive adhesive base composition I, the silicone pressure-sensitive adhesive base composition II or the silicone pressure-sensitive adhesive base composition III, and the component (C) are placed in a flask according to the amounts shown in the table, and 83.4 parts of N-heptane is added. Dilute and stir to dissolve. 0.8 part of the component (E) was added to the obtained solution, and the mixture was stirred and mixed to prepare a silicone pressure-sensitive adhesive composition. With respect to this silicone pressure-sensitive adhesive composition, a cured product was prepared by the method described below, and the skin adhesive strength, the adhesive strength at the time of re-application, and the adhesive strength at the time of re-application were measured according to the following measurement methods. The results are shown in the table.

[Skin adhesion]
An N-heptane 40% by mass solution of the silicone pressure-sensitive adhesive composition was applied to a polyethylene terephthalate film having a thickness of 23 μm and a width of 25 mm using an applicator so that the thickness after curing became 100 μm, and then 130 ° C. for 1 minute The composition was heated and cured under the conditions described above to produce an adhesive tape. This adhesive tape was stuck to a human forearm and allowed to stand at room temperature for about 30 minutes. At 25 ° C., one end of the adhesive tape was peeled off, and a tensile tester was used at a pulling speed of 60 ° / min. The force (N / 25 mm) required to peel off the forearm was measured at an angle.

[Skin adhesion after re-pasting]
The adhesive tape peeled off by the skin adhesive strength measurement was again attached to the human forearm and left at room temperature for about 30 minutes. At 25 ° C., one end of the adhesive tape was peeled off at 60 ° C. using a tensile tester. The force (N / 25 mm) required to peel off the forearm at an angle of 90 ° at a pulling speed of minutes was measured.

[Confirm reworkability]
In the above-mentioned measurement of skin adhesive strength, reworkability with respect to a human forearm was evaluated in three stages based on the following criteria.
<Standard>
〇: Decrease in adhesive strength when re-applied is less than 15% Δ: Decrease in adhesive strength when re-applied is 15% or more and less than 30% ×: Adhesion when re-peeled is 30% or more when re-applied Decrease rate (%) of adhesive strength at time = (skin adhesive strength-skin adhesive strength after re-application) ÷ skin adhesive strength × 100

[Evaluation of peeling from skin]
In the above-mentioned skin adhesion measurement, pain when peeling from a human forearm was evaluated in three steps based on the following criteria.
<Standard>
〇: Pain is not felt △: Some pain is felt ×: Strong pain is felt

[Appearance of adhesive tape after peeling]
In confirming the reworkability, the appearance of the pressure-sensitive adhesive tape obtained by the second re-peeling was observed, and evaluated on a three-point scale based on the following criteria.
<Evaluation criteria>
〇: Slight keratin and body hair are observed. △: Skerma and body hair are observed. ×: Severe skin and body hair are observed.

[Durability of adhesive tape]
A 40% by mass solution of the silicone pressure-sensitive adhesive composition in N-heptane is applied to a polyethylene terephthalate film having a thickness of 23 μm and a width of 25 mm using an applicator so that the thickness after curing becomes 100 μm, and then at 130 ° C. for 1 minute. It was heated and cured under the conditions to prepare an adhesive tape. This adhesive tape was stuck to the forearm of a person, and the condition of the test piece was observed 24 hours after sticking, and the following criteria were used according to the degree of deformation, wrinkling, peeling, and occurrence of adhesive residue after peeling. Based on the above, evaluation was made in three steps.
<Evaluation criteria>
〇: Almost no occurrence △: Some occurrence ×: Notable occurrence

Claims (5)

(A) a diorganopolysiloxane having two or more alkenyl groups in one molecule and having an alkenyl group content of 0.0005 mol / 100 g or more and less than 0.15 mol / 100 g: 55 to 95 parts by mass;
(B) R ¹ ₃ SiO _1/2 units (R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms the same or different.), A SiO ₂ units, a hydroxyl group bonded to a silicon atom containing siloxane units having the siloxane units and / or silicon atoms alkoxy group having 1 to 6 carbon atoms bonded to the molar ratio of (R ¹ ₃ SiO _1/2 units / SiO ₂ units) 0.5 a Organopolysiloxane having a molecular weight of 1.5 to 45 parts by mass (provided that the total of the components (A) and (B) is 100 parts by mass);
(C) An organohydrogenpolysiloxane having three or more Si-H groups in one molecule: the molar ratio of (Si-H group in component (C) / alkenyl group in component (A)) is 0.5. ~ 3.0,
(E) Platinum group metal-based catalyst: 1 to 5,000 ppm as platinum group metal on a mass basis relative to the total amount of components (A) and (B)
An addition-curable silicone pressure-sensitive adhesive composition for application to the skin, comprising: The addition-curable silicone pressure-sensitive adhesive composition for application to the skin according to claim 1, wherein the component (C) is an organohydrogenpolysiloxane represented by the following formula (1).

(Wherein, R ² is a monovalent hydrocarbon group having 1 to 10 carbon atoms having the same or different aliphatic unsaturated bonds, a is an integer of 0 or more, b is an integer of 1 or more, c is an integer of 0 or more, d is an integer of 0 or more, e is an integer of 0 or more, f is an integer of 0 or more, a + b ≧ 3, and 3 ≦ a + b + c + d + e + f ≦ 1,000.)   The compounding amount of the component (C) is such that the molar ratio of (Si—H group in the component (C) / alkenyl group in the component (A)) is 0.75 to 2.0. 3. The addition-curable silicone pressure-sensitive adhesive composition for application to skin according to item 2.   Further, as component (D), an addition reaction control agent is contained in an amount of 0.05 to 8 parts by mass based on a total of 100 parts by mass of components (A) and (B). Reaction-curable silicone pressure-sensitive adhesive composition for application to skin.   A skin patch having a base material and an adhesive layer comprising a cured product of the addition-curable silicone pressure-sensitive adhesive composition for skin sticking according to any one of claims 1 to 4 on at least one surface of the base material. Adhesive tape.