JP2006160923A - Solvent-free silicone adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicone adhesive composition which does not contain an organic solvent, can prevent the absorption of ultraviolet rays and the like, the contamination of electronic/electric parts, affections to human bodies, and irritation to the skins, with left/evaporated substances, has a controlled adhesive force, and can easily be repeeled without deforming or breaking an adherend. <P>SOLUTION: This solvent-free silicone adhesive composition comprises (A) a polydiorganosiloxane having at least two alkenyl group-containing organic groups in the molecule and having branches, (B) a polyorganohydrosiloxane having at least two SiH groups in the molecule, (C) a polyorganosiloxane comprising R<SP>1</SP><SB>3</SB>SiO<SB>0.5</SB>units and SiO<SB>2</SB>units and having an R<SP>1</SP><SB>3</SB>SiO<SB>0.5</SB>unit/SiO<SB>2</SB>unit molar ratio of 0.6 to 1.7 (R<SP>1</SP>is a 1 to 10C monovalent hydrocarbon group), and (D) a platinum-based catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a silicone pressure-sensitive adhesive composition having a controlled adhesive strength.

  Adhesive tapes and labels that use silicone adhesives are acrylic adhesives, rubber adhesives, etc., because the silicone adhesive layer has excellent heat resistance, cold resistance, weather resistance, electrical insulation and chemical resistance. Organic adhesives are used in harsh environments where they are altered or deteriorated. In addition, since it adheres well to various adherends, it is difficult to adhere with organic adhesives such as acrylic adhesives and rubber adhesives. Used for containing surfaces.

  For example, a pressure-sensitive adhesive tape using a silicone pressure-sensitive adhesive is used at the time of manufacturing and processing electronic / electrical parts and during assembly. When heat treatment is performed in this manufacturing process, it may be necessary to protect the entire surface or partially, masking or temporary fixing. Adhesive tapes used for such applications and adhesive tapes used in the manufacture, fixing, and binding of electronic and electrical parts exposed to high temperatures are made of silicone adhesive that has heat resistance even after heating above 250 ° C. Is preferred. However, in recent years, the process of manufacturing and processing electronic / electrical components has become multi-stage, and heating, cooling, cleaning, irradiation, and the like are repeated, and the precision and complexity of the electronic / electrical component are increasing. Furthermore, it is often processed in a closed space such as a clean room or clean booth for the purpose of dust-free.

  Attaching or masking an adhesive tape or adhesive label using a conventional silicone adhesive to the adherend, and receiving a high temperature history of 100 to 250 ° C., trace amounts of toluene, xylene, ethylbenzene, Aromatic hydrocarbons such as benzene may volatilize. These aromatic hydrocarbons are contained in the silicone pressure-sensitive adhesive composition. In a closed space in the manufacturing process of electrical / electronic parts as described above, adhesive tape using silicone adhesive is used to generate volatile substances of aromatic hydrocarbons, and UV irradiation is performed in subsequent processes. When performed, ultraviolet rays are absorbed by aromatic hydrocarbons, which may cause a problem that irradiation is not performed efficiently.

  Furthermore, recent electronic components have become smaller, finer, and thinner. When masking for protection with an adhesive tape using a silicone adhesive that has been widely used in the past, the adhesive is too strong when the masking tape is peeled off (re-peeling) after the prescribed treatment. The fine structure on the electronic component, which is the body, or the electronic component itself may be deformed or destroyed. In addition, when masking these electronic components, an operation of attaching a tape to a large area may be performed. Even when the masking tape attached to a large area is peeled off, if the adhesive force is too strong, it may be difficult to remove, or the adherend may be deformed or destroyed. Also, in addition to the adhesive tape, when sticking an adhesive processed film to an adherend, if the adhesive film is too strong, it is difficult to peel off, the adherend is deformed, And sometimes destroyed. Examples of the adherend include various electronic components, flat displays, window glass, wall surfaces, and the like, and examples of the adhesive processed film include an antifouling film, an anti-scratch film, an antireflection film, a light shielding film, and glass scattering. Prevention film, marking film for decoration and advertisement.

  In addition, in the application of adhesive tapes and labels for construction, interiors, etc., the surface of the adherend contains silicone resin or fluorine resin for the purpose of water repellency, oil repellency, dirt prevention, etc. May be treated with fluorine. A silicone adhesive may be used on such a surface because an acrylic adhesive does not adhere well. Adhesive paper for wallpaper, adhesive paper for decorative boards such as furniture, adhesive tape for waterproofing and airtightness, adhesive tape for indoor interior fixing, repair tape, decorative fixing tape, adhesive film for preventing glass scattering, adhesive for light shielding In adhesive tapes and adhesive labels used in living environments such as films and tapes for fixing automobile interiors, if aromatic hydrocarbon solvent remains, volatilizes, and stays in indoor air, it is extremely small. However, it may cause chemical allergy, sick house syndrome, chemical sensitivity, etc.

  Furthermore, in applications such as adhesives, adhesive bandages, surgical tapes, sports taping tapes, and the like that are directly applied to the skin, the presence of aromatic hydrocarbon solvent can cause irritation to the skin.

In order to solve such a problem, an organopolysiloxane having a lower alkenyl group at both ends of a linear molecular chain (not having a branch), a polyorgano containing R ₃ SiO _0.5 unit and SiO ₂ unit A solvent-free silicone pressure-sensitive adhesive composition comprising siloxane, an organohydrogenpolysiloxane having at least two SiH molecules in one molecule, and a platinum-based catalyst is known. (Patent Document 1) This product may have a low cross-linking density, an adhesive force that is higher than necessary for use in a masking tape, and inferior removability.

Japanese Patent Laid-Open No. 6-84494

  The present invention improves the above situation and prevents absorption of ultraviolet rays, contamination of electronic / electrical parts, effects on the human body, and irritation to the skin by substances that do not contain organic solvents and remain or volatilize. Another object of the present invention is to provide a silicone pressure-sensitive adhesive composition with an adjusted adhesive force that can be easily peeled off without deforming or destroying the adherend.

As a result of intensive studies, the present inventor, as a silicone pressure-sensitive adhesive composition, (A) polydiorganosiloxane (B) 1 having at least two alkenyl group-containing organic groups in one molecule and having a branch. containing polyorganohydrosiloxanes _^(C) R 1 _{3 SiO 0.5} units and SiO ₂ units having at least two SiH groups in the ^molecule, the molar ratio of _R 1 _{3 SiO 0.5} units / SiO ₂ units When a polyorganosiloxane (R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms) of 0.6 to 1.7 and (D) a solvent-free silicone pressure-sensitive adhesive composition containing a platinum-based catalyst is used. It has been found that it is effective in achieving the above-mentioned purpose.

  Furthermore, the total of the components (A) and (B) is 90 to 30 parts by mass with respect to the total of 100 parts by mass of the components (A), (B) and (C) described above. The amount of the SiH group in the component (B) relative to the alkenyl group is 0.5 to 5 and the platinum catalyst of the component (C) is 10 to 70 parts by mass (D) as the platinum component. If you use a solvent-free silicone pressure-sensitive adhesive composition that contains no organic solvent, it will absorb ultraviolet radiation, etc. due to residual or volatilized substances, contamination of electronic and electrical components, effects on the human body, It can be used effectively for adhesive tapes, adhesive films, adhesive sheets, adhesive labels, etc. that can prevent irritation and have an adhesive force that can be easily removed without deforming or destroying the adherend. Effective to achieve the above objectives I found out.

  According to the present invention, a solventless silicone pressure-sensitive adhesive composition that does not contain an aromatic solvent can be obtained. There is no harmful effect of the aromatic solvent remaining on the adhesive tape. Do not destroy or deform the adherend during re-peeling.

The polydiorgano having an alkenyl group-containing organic group having a branch in the molecule having a viscosity of 5 to 1000 mPa · s at 25 ° C., wherein the component (A) is represented by the following average composition formula (1): Siloxane.
(R ₃ SiO _1/2 ) _a- (R ₂ SiO) _b- (RSiO _3/2 ) _c- (SiO ₂ ) _d (1) (wherein R may be the same or different and has 1 to 10 carbon atoms) And at least two of R include an alkenyl group-containing organic group, a is an integer of 2 or more, b is an integer of 3 or more, c and d are integers of 0 or more, and 1 ≦ (c + d, a + b + c + d ≦ 400)

  R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and two or more of all R groups are alkenyl group-containing organic groups. Specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group or a tolyl group, and the carbon atoms of these groups Examples thereof include a 3,3,3-trifluoropropyl group, a 3-hydroxypropyl group, a 3-aminopropyl group, etc., in which part or all of the hydrogen atoms bonded to are substituted with other groups. A methyl group and a phenyl group are particularly preferable.

  The alkenyl group-containing organic group is preferably one having 2 to 10 carbon atoms, such as vinyl group, allyl group, hexenyl group, octenyl group, acryloylpropyl group, acryloylmethyl group, methacryloylpropyl group, cyclohexenylethyl group, vinyl. An oxypropyl group is preferred, and a vinyl group is particularly preferred industrially.

  Here, “a”, “b”, “c” and “d” are numbers that make the viscosity of the polydiorganosiloxane at 25 ° C. 5 to 1000 mPa · s. Specifically, “a” is an integer of 2 or more, and “b” is 3 or more. Integers, c and d are integers of 0 or more and 1 ≦ c + d and a + b + c + d ≦ 400. Preferably, a is an integer of 3 or more, b is an integer of 10 or more, and c and d are integers of 0 or more. 1 ≦ c + d, a + b + c + d ≦ 250.

Moreover, even if it is polydiorganosiloxane which has an alkenyl-group containing organic group which has a branch in the molecule | numerator whose viscosity in 25 degreeC which is shown by the following average composition formula (4) as (A) component is 5-1000 mPa * s. Good.
_{(R 3 SiO 1/2) C +} 2 - (R 2 SiO) b - (RSiO 3/2) c (4)
(However, R represents the same group as described above. B is an integer of 3 or more, c is an integer of 1 or more, and b + 2c + 2 ≦ 400.)

Furthermore, what has an alkenyl-group containing organic group at the terminal of a molecular chain so that (A) component is shown with the following average composition formula is further more preferable.
_{(XR 2 SiO 1/2) a -} (R 2 SiO) b - (RSiO 3/2) c - (SiO 2) d
_{(XR 2 SiO 1/2) C +} 2 - (R 2 SiO) b - (RSiO 3/2) c
X is an alkenyl group-containing organic group, and R, a, b, c, and d are the same as described above.

  The alkenyl group content of the component (A) is 0.005 to 0.25 mol / 100 g, preferably 0.008 to 0.1 mol / 100 g. If it is 0.005 mol / 100 g or less, the adhesive strength is too high, and if it is 0.25 mol / 100 g or more, the adhesive strength and tack are too low, it is not suitable.

  The viscosity of the component (A) is preferably 5 to 1000 mPa · s, particularly 50 to 700 mPa · s at 25 ° C. If it is 5 mPa · s or less, the curability is lowered or the adhesive strength is lowered, which is not suitable. If it exceeds 1000 mPa · s, the composition becomes too viscous and stirring and coating during production become difficult. Furthermore, (A) component may use 2 or more types together.

  The component (A) is usually produced by polymerizing a monomer such as octamethylcyclotetrasiloxane, a silane compound or siloxane compound having a dimethylvinylsiloxane unit, and a silane compound or siloxane compound having a methylsiloxane unit using a catalyst. However, since cyclic low-molecular siloxane is contained after polymerization, it is preferable to use a product obtained by distilling off this cyclic low-molecular siloxane while aerating an inert gas under heating and / or reduced pressure.

  Component (B) is a crosslinking agent, which is an organohydropolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule, and linear, branched, and cyclic compounds can be used. Specific examples of the component (B) include those represented by the following formulas (2) and (3), but are not limited thereto.

及び／または

And / or

（但し、Ｒ^２は同一または異種の脂肪族不飽和結合を有さない１価炭化水素基であり、αは０または１、ｐ、ｑは０以上の整数。αが０のときは、ｐは２以上であり、このオルガノヒドロポリシロキサンの２５℃における粘度が１〜１，０００ｍＰａ・ｓとなる数を示す。また、ｓは２以上の整数、ｔは０以上の整数で、かつ３≦ｓ＋ｔ、好ましくは３≦ｓ＋ｔ≦８の整数を示す。）

(However, R ² is a monovalent hydrocarbon group having no identical or different aliphatic unsaturated bond, α is 0 or 1, p, q is an integer of 0 or more. When α is 0, p is Is a number at which the viscosity of this organohydropolysiloxane at 25 ° C. is 1 to 1,000 mPa · s, s is an integer of 2 or more, t is an integer of 0 or more, and 3 ≦ s + t, preferably an integer of 3 ≦ s + t ≦ 8.)

Here, R ² preferably has 1 to 10 carbon atoms. For example, alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group, a cycloalkyl group such as a cyclohexyl group, a phenyl group, and a tolyl group. A 3-aminopropyl group in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with other groups such as halogen, amino group, hydroxyl group, cyano group, etc. 3,3,3-trifluoropropyl group, 3-hydroxypropyl group, 3-cyanopropyl group and the like are also exemplified. A methyl group and a phenyl group are particularly preferable.

  The viscosity of this organohydropolysiloxane at 25 ° C. is preferably 1 to 1,000 mPa · s, and more preferably 1 to 700 mPa · s. A mixture of two or more kinds may be used.

  The amount of component (B) used is such that the molar ratio of SiH groups in component (B) to alkenyl groups in component (A) is in the range of 0.5 to 5, particularly 0.8 to 3. Is preferred. If it is less than 0.5, the crosslink density is low, and the holding power may be lowered. If it exceeds 5, the crosslink density is high and sufficient adhesive strength and tack may not be obtained.

The component (C) contains R ¹ ₃ SiO _0.5 units (R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms) and SiO ₂ units, and R ¹ ₃ SiO _0.5 units / SiO ₂ It is a polyorganosiloxane having a unit molar ratio of 0.6 to 1.7. If the molar ratio of R ¹ ₃ SiO _0.5 unit / SiO ₂ unit is less than 0.6, the adhesive force and tack may be lowered, and if it exceeds 1.7, the adhesive force and holding force may be lowered.

Examples of R ¹ include an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group, a cycloalkyl group, a phenyl group, a vinyl group, an allyl group, and a hexenyl group. A methyl group is preferred.

The component (C) may contain an OH group, and the OH group content is preferably 0.01 to 4.0% by mass. When the OH group is less than 0.01% by mass, the cohesive force of the pressure-sensitive adhesive may be lowered, and when it exceeds 4.0% by mass, the tackiness of the pressure-sensitive adhesive is not preferable. It is also possible to within a range that does not impair the characteristics of the present invention contains ^R 1 _{SiO 1.5} ^units, a _R 1 2 SiO units (B) component. In addition, (B) component may use 2 or more types together.

  The blending ratio of the sum of the components (A) and (B) and the component (C) is preferably 90/10 to 30/70, particularly 70/30 to 35/65, as a mass ratio. When the total blending ratio of the polydiorganosiloxanes of the components (A) and (B) is lower than 30/70, the adhesive strength and holding power are reduced, or the viscosity of the composition becomes too high and coating becomes difficult. And if it exceeds 90/10, the adhesive strength and tack decrease.

  Component (D) is an addition reaction catalyst, containing chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reaction product of chloroplatinic acid and alcohol, a reaction product of chloroplatinic acid and an olefin compound, and containing chloroplatinic acid and a vinyl group Examples thereof include a reaction product with siloxane, a platinum-olefin complex, a platinum-vinyl group-containing siloxane complex, and a rhodium complex.

  The amount of component (D) added is preferably 5 to 2,000 ppm, more preferably 10 to 500 ppm, in terms of platinum, with respect to the sum of components (A), (B), and (C). If it is less than 5 ppm, the curability is lowered, the crosslinking density is lowered and the holding power may be lowered, and if it exceeds 2,000 ppm, the usable time of the treatment bath may be shortened.

  Component (E) is a control agent, and is added to prevent the treatment liquid from thickening or gelling before heat curing when the silicone pressure-sensitive adhesive composition is prepared or applied to the substrate. It is. Specific examples include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-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.

  (E) The compounding quantity of a component should just be the range of 0-8.0 mass parts with respect to a total of 100 mass parts of a component (A), (B), (C) component, and 0.05-2. 0 parts by mass is preferred. If it exceeds 8.0 parts by mass, curability may be lowered.

  The composition of the present invention is produced by mixing and dissolving the component (A), the component (B), the component (C), and the component (E) as necessary. When the component (C) is supplied in a form dissolved in a solvent, after the components (A), (B), and (C) are mixed, the solvent may be removed under normal temperature to heating and / or reduced pressure. Thereafter, the component (E) may be added. Usually, in this state, the container is filled for storage and transportation. When manufacturing an adhesive tape, an adhesive sheet, an adhesive label, etc., this thing is added and mixed with the (D) component as needed, and is applied to the various base materials shown later.

  Alternatively, the composition of the present invention can also be produced by adding the components (B) and (E) to a product obtained by mixing the components (A) and (C) in the presence of a base catalyst. You may use the solvent shown later together as needed. Base catalysts include metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, carbonates such as sodium carbonate and potassium carbonate, bicarbonates such as sodium bicarbonate, sodium methoxide And metal alkoxides such as potassium butoxide, organic metals such as butyl lithium, potassium silanolates, ammonia gas, aqueous ammonia, nitrogen compounds such as methylamine, trimethylamine, and triethylamine. Ammonia gas and aqueous ammonia are preferred. Although the temperature of mixing can be 20-150 degreeC, what is necessary is just to carry out normally at the reflux temperature of room temperature-the organic solvent. The time is not particularly limited, but may be 0.5 to 10 hours, preferably 1 to 6 hours.

  Furthermore, a neutralizing agent that neutralizes the base catalyst may be added as necessary after completion of the reaction. Examples of the neutralizing agent include acidic gases such as hydrogen chloride and carbon dioxide, organic acids such as acetic acid, octylic acid, and citric acid, and mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid.

  This product is usually filled in a container for storage and transportation by adjusting the concentration of volatile components to, for example, 5% by mass or less. When manufacturing adhesive tapes, adhesive sheets, adhesive labels, etc., dilute this product with an organic solvent as necessary, add and mix component (D), and apply to various substrates shown below. Is done.

  In addition to the above components, optional components can be added to the silicone pressure-sensitive adhesive composition of the present invention. For example, non-reactive polyorganosiloxanes such as polydimethylsiloxane and polydimethyldiphenylsiloxane, antioxidants such as phenols, quinones, amines, phosphoruss, phosphites, sulfurs and thioethers, hindered amines -Based, triazole-based, benzophenone-based light stabilizers, phosphate ester-based, halogen-based, phosphorus-based, antimony-based flame retardants, cationic surfactants, anionic surfactants, non-ionic surfactants and other antistatic agents, Dyes and pigments can be used.

  Furthermore, the present invention is basically used in a solvent-free system, but when a solvent is used to adjust the viscosity during coating, hexane, heptane, octane, isooctane, decane, cyclohexane, methyl Aliphatic hydrocarbon solvents such as cyclohexane and isoparaffin. Ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonyl acetone, cyclohexanone, ethyl acetate, propyl acetate, isopropyl acetate Ester solvents such as butyl acetate 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 2-functional solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, 2-butoxyethyl acetate, hexamethyldisiloxane, octamethyltrisiloxane, Data tetramethyl cyclotetrasiloxane, decamethylcyclopentasiloxane, tris (trimethylsiloxy) methylsilane, tetrakis (trimethylsiloxy) silane, siloxane solvents such or mixed solvents thereof, etc. can be used.

  Aliphatic hydrocarbon solvents such as hexane, heptane, isooctane, octane, decane, cyclohexane, methylcyclohexane and isoparaffin are preferred. A mixed solvent of an aliphatic hydrocarbon solvent and an ether solvent, an ester solvent, a multifunctional solvent having both an ether group and an ester group, or the like is also preferable.

The silicone pressure-sensitive adhesive composition formulated as described above can be applied to various substrates and cured under predetermined conditions to obtain a pressure-sensitive adhesive layer.
As a base material, plastic films such as polyester, polytetrafluoroethylene, polyimide, polyphenylene sulfide, polyamide, polycarbonate, polystyrene, polypropylene, polyethylene, polyvinyl chloride, metal foil such as aluminum foil, copper foil, Japanese paper, synthetic paper, Examples thereof include paper such as polyethylene laminated paper, cloth, glass fiber, and a composite base material formed by laminating a plurality of these.

  In order to improve the adhesion between the base material and the adhesive layer, a primer-treated, corona-treated, etched, plasma-treated, or sand-blasted material may be used. Corona treatment and primer treatment are preferred.

  Examples of primer compositions that can be used include polydiorganosiloxanes having SiOH groups at the terminals, polysiloxanes having SiH groups and / or polysiloxanes having alkoxy groups, condensation reaction catalysts, and condensation-type silicone primer compositions, vinyl And an addition-type silicone primer composition containing a polydiorganosiloxane having an alkenyl group such as a group, a polysiloxane having a SiH group, and an addition reaction catalyst.

The coating method may be applied using a known coating method, comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, screen coating, dipping. Examples thereof include coating and cast coating.
The coating amount can be 2 to 1000 μm, particularly 3 to 500 μm, as the thickness of the adhesive layer after curing.

  The curing conditions may be 80 to 130 ° C. for 30 seconds to 3 minutes, but are not limited thereto.

  An adhesive tape or the like may be produced by directly applying to the base material as described above, or after being applied to a release film or release paper that has been subjected to release coating, cured, and then applied to the base material. You may manufacture an adhesive tape etc. with the transfer method to match.

  The silicone pressure-sensitive adhesive composition formulated as described above uses a pressure-sensitive adhesive tape coated on a polyimide film (thickness 25 μm) so that the thickness of the pressure-sensitive adhesive layer is 40 μm, and peels off 180 ° as shown in JIS Z 0237. When measured by the method for measuring adhesive strength, a value of 0.01 to 4.0 N / 25 mm is preferable. Preferably, it is 0.01 to 3.0 N / 25 mm. If it is 0.01 N / 25 mm or less, the adhesive strength is too low to obtain a sufficient masking property, and if it is 4.0 N / 25 mm or more, the adhesive strength is too high and the removability may be poor.

  Although it does not specifically limit as an adherend which can be masked with the adhesive tape etc. which were manufactured using the silicone adhesive composition of this invention, The following can be illustrated. For applications such as electronic component manufacturing, metals and alloys such as stainless steel, copper, iron, aluminum, chromium, gold, etc., and metal, glass, ceramics, ceramics, and polytetrafluorocarbons whose surfaces are plated, rust-proofed, and coated. Examples thereof include resins such as ethylene, polyimide, epoxy resin, and novolac resin. In addition to the above, there are papers such as plywood, wood, Japanese paper, and synthetic paper, and a combination of a plurality of these in addition to the above.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In addition, the part in an example shows the mass part, and a characteristic value shows the measured value by the following test method. Me represents a methyl group and Vi represents a vinyl group.

The adhesive silicone adhesive composition solution was applied to a polyimide film having a thickness of 25 μm and a width of 25 mm using an applicator so that the thickness after curing was 40 μm, and then heated and cured at 120 ° C. for 1 minute. To produce an adhesive tape. This adhesive tape was affixed to a stainless steel plate and pressed by reciprocating a roller covered with a rubber layer having a weight of 2 kg. After standing at room temperature for about 20 hours, the force (N / 25 mm) required to peel the tape from the stainless steel plate at an angle of 180 ° at a speed of 300 mm / min was measured using a tensile tester.

A pressure-sensitive adhesive tape was prepared in the same manner as in the evaluation of the holding power and the adhesive strength. The adhesive tape is affixed to the lower end of the stainless steel plate so that the adhesive area is 25 × 25 mm, a weight of 1 kg is applied to the lower end of the adhesive tape, and the deviation distance after standing vertically at 250 ° C. for 1 hour is determined. Reading was measured with a microscope.

An adhesive tape was prepared in the same manner as in the probe tack adhesion evaluation. The tack of this adhesive tape was measured using a probe tack tester manufactured by Polyken.

A pressure-sensitive adhesive tape was prepared in the same manner as in the evaluation of residual toluene amount adhesive strength. About 10 cm of this adhesive tape was weighed and then sealed in a vial. After the vial was heated at 260 ° C. for 1 hour, the amount of toluene generated per unit adhesive tape mass was quantified by analyzing the gas in the vial by gas chromatography.

A pressure-sensitive adhesive tape was prepared in the same manner as in the evaluation of removability adhesive strength. This adhesive tape was affixed to a copper foil having a thickness of 50 μm, left at 150 ° C. for 1 hour, and then peeled off. The copper foil did not deform, and the surface of the adherend had no adhesive remaining and could be peeled off. The copper foil was deformed or the surface had adhesive remaining on the surface was defective.

[Example 1]
Branched vinyl group-containing polydimethylsiloxane (A-1) represented by the following average composition formula (alkenyl group content 0.025 mol / 100 g, 250 mPa · s) (36.1 parts),
_{(ViMe 2 SiO 1/2) 3 -} (Me 2 SiO) 160 - (MeSiO 3/2) 1
Polymethylhydrosiloxane (B-1) having a SiH group represented by the following formula (8.9 parts),

Ｍｅ_３ＳｉＯ_０．５単位およびＳｉＯ_２単位を含有し、Ｍｅ_３ＳｉＯ_０．５単位／ＳｉＯ_２単位のモル比が０．８５であるポリオルガノシロキサン（Ｃ）の６０％トルエン溶液（９１．７部）を混合し、９０℃、減圧下でトルエンを留去した。冷却したのち、この生成物（１００部）に、エチニルシクロヘキサノール（０．２０部）、白金分を０．５質量％含有する白金−ビニル基含有シロキサン錯体のシリコーン溶液（１．０部）を添加し混合し、シリコーン粘着剤組成物を調製した。
このシリコーン粘着剤の糊残り性、粘着力、保持力、プローブタック、再剥離性を測定した。結果を表１に示す。

A 60% toluene solution of polyorganosiloxane (C) containing _0.5 units of Me ₃ SiO and ₂ units of SiO ₂ and having a molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units of 0.85 (91.7 Part) and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 2]
Branched vinyl group-containing polydimethylsiloxane (A-1) (32.1 parts), SiH group-containing polymethylhydrosiloxane (B-1) (7.9 parts), Me ₃ SiO _0.5 unit and SiO A 60% toluene solution (100 parts) of polyorganosiloxane (C) containing ₂ units and having a molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units of 0.85 was mixed, and 90 ° C. under reduced pressure. The toluene was distilled off. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 3]
Branched vinyl group-containing polydimethylsiloxane (A-1) (72.2 parts), SiH group-containing polymethylhydrosiloxane (B-1) (17.8 parts), Me ₃ SiO _0.5 unit and SiO A 60% toluene solution (16.7 parts) of polyorganosiloxane (C) containing ₂ units and having a molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units of 0.85 was mixed, Toluene was distilled off under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 4]
Branched vinyl group-containing polydimethylsiloxane (A-2) represented by the following average composition formula (alkenyl group content 0.048 mol / 100 g, 110 mPa · s) (30.6 parts),
(ViMe ₂ SiO _1/2 ) _3- (Me ₂ SiO) _80- (MeSiO _3/2 ) ₁
Polymethylhydrosiloxane (B-1) (14.4 parts) having SiH groups, Me ₃ SiO _0.5 units and SiO ₂ units, and the molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 5]
Branched vinyl group-containing polydimethylsiloxane (A-1) (41.0 parts), polymethylhydrosiloxane (B-2) having an SiH group represented by the following formula (3.7 parts),

次式で示されるＳｉＨ基を有するポリメチルヒドロシロキサン（Ｂ−３）（０．３部）、

Polymethylhydrosiloxane (B-3) having a SiH group represented by the following formula (0.3 part),

Ｍｅ_３ＳｉＯ_０．５単位およびＳｉＯ_２単位を含有し、Ｍｅ_３ＳｉＯ_０．５単位／ＳｉＯ_２単位のモル比が０．８５であるポリオルガノシロキサン（Ｃ）の６０％トルエン溶液（９１．７部）を混合し、９０℃、減圧化でトルエンを留去した。冷却したのち、この生成物（１００部）に、エチニルシクロヘキサノール（０．２０部）、白金分を０．５質量％含有する白金−ビニル基含有シロキサン錯体のシリコーン溶液（１．０部）を添加し混合し、シリコーン粘着剤組成物を調製した。
このシリコーン粘着剤の糊残り性、粘着力、保持力、プローブタック、再剥離性を測定した。結果を表１に示す。

A 60% toluene solution of polyorganosiloxane (C) containing _0.5 units of Me ₃ SiO and ₂ units of SiO ₂ and having a molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units of 0.85 (91.7 Part), and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 6]
A branched vinyl group-containing polydimethylsiloxane (A-3) represented by the following average composition formula (alkenyl group content 0.026 mol / 100 g, 360 mPa · s) (35.8 parts),
_{(ViMe 2 SiO 1/2) 4 -} (Me 2 SiO) 200 - (MeSiO 4/2) 1
Polymethylhydrosiloxane (B-1) (9.2 parts) having SiH groups, Me ₃ SiO _0.5 units and SiO ₂ units, and the molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.

  The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Example 7]
A branched vinyl group-containing polydimethylsiloxane (A-4) represented by the following average composition formula (alkenyl group content 0.047 mol / 100 g, 220 mPa · s) (30.8 parts),
(ViMe ₂ SiO _1/2 ) _3- (Me ₂ SiO) _80- (MeSiO _3/2 ) ₂
Polymethylhydrosiloxane (B-1) (14.2 parts) having SiH groups, Me ₃ SiO _0.5 units and SiO ₂ units, and the molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.
[Example 8]
Branched vinyl group-containing polydimethylsiloxane (A-5) represented by the following average composition formula (alkenyl group content 0.031 mol / 100 g, 80 mPa · s) (34.2 parts),
(ViMe ₂ SiO _1/2 ) _2- (Me ₃ SiO _1/2 ) _2- (Me ₂ SiO) _80- (MeSiO _3/2 ) ₂
Polymethylhydrosiloxane (B-1) (10.8 parts) having SiH groups, Me ₃ SiO _0.5 units and SiO ₂ units, and the molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.
[Example 9]
Branched vinyl group-containing polydimethylsiloxane (A-6) represented by the following average composition formula (alkenyl group content: 0.020 mol / 100 g, 950 mPa · s) (37.6 parts),
_{(ViMe 2 SiO 1/2) 3 -} (ViMeSiO) 2 - (Me 2 SiO) 330 - (MeSiO 3/2) 1
Polymethylhydrosiloxane (B-1) having SiH group (7.4 parts), Me ₃ SiO _0.5 unit and SiO ₂ unit, and the molar ratio of Me ₃ SiO _0.5 unit / SiO ₂ unit is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Comparative Example 1]
Non-branched vinyl group-containing polydimethylsiloxane represented by the following formula (alkenyl group content 0.020 mol / 100 g, 400 mPa · s) (A-7) (37.6 parts),
(ViMe ₂ SiO _1/2 ) _2- (Me ₂ SiO) ₁₃₀
Polymethylhydrosiloxane (B-1) having SiH group (7.4 parts), Me ₃ SiO _0.5 unit and SiO ₂ unit, and the molar ratio of Me ₃ SiO _0.5 unit / SiO ₂ unit is A 60% toluene solution (91.7 parts) of polyorganosiloxane (C) of 0.85 was mixed, and toluene was distilled off at 90 ° C. under reduced pressure. After cooling, to this product (100 parts), ethynylcyclohexanol (0.20 part), a platinum-vinyl group-containing siloxane complex silicone solution (1.0 part) containing 0.5% by mass of platinum is added. It added and mixed and the silicone adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

[Comparative Example 2]
Non-branched vinyl group-containing polydimethylsiloxane represented by the following formula (alkenyl group content 0.007 mol / 100 g, 2200 mPa · s dissolved in toluene to a concentration of 30%) (A-8) (44.0 parts),
_{(ViMe 2 SiO 1/2) 2 -} (ViMeSiO) 14 - (Me 2 SiO) 2985
A polymethylhydrosiloxane (B-4) having an SiH group represented by the following formula (1.0 part),

Ｍｅ_３ＳｉＯ_０．５単位およびＳｉＯ_２単位を含有し、Ｍｅ_３ＳｉＯ_０．５単位／ＳｉＯ_２単位のモル比が０．８５であるポリオルガノシロキサン（Ｃ）の６０％トルエン溶液（９１．７部）、トルエン（３０．０部）を混合し、シリコーン分を約６０％とした。この生成物（１００部）に、エチニルシクロヘキサノール（０．１２部）、白金分を０．５質量％含有する白金−ビニル基含有シロキサン錯体のシリコーン溶液（０．６部）を添加し混合し、シリコーン粘着剤組成物を調製した。
このシリコーン粘着剤の糊残り性、粘着力、保持力、プローブタック、再剥離性を測定した。結果を表１に示す。

A 60% toluene solution of polyorganosiloxane (C) containing _0.5 units of Me ₃ SiO and ₂ units of SiO ₂ and having a molar ratio of Me ₃ SiO _0.5 units / SiO ₂ units of 0.85 (91.7 Part) and toluene (30.0 parts) were mixed to make the silicone content about 60%. To this product (100 parts), ethynylcyclohexanol (0.12 parts) and a platinum-vinyl group-containing siloxane complex silicone solution (0.6 parts) containing 0.5% by mass of platinum are added and mixed. A silicone pressure-sensitive adhesive composition was prepared.
The adhesive residue, adhesive strength, holding power, probe tack, and removability of this silicone adhesive were measured. The results are shown in Table 1.

Claims (7)

(A) A polydiorganosiloxane having at least two alkenyl group-containing organic groups in one molecule and a branched polydiorganosiloxane (B) A polyorganohydrosiloxane (C) R having at least two SiH groups in one molecule A polyorganosiloxane containing ¹ ₃ SiO _0.5 units and SiO ₂ units and having a molar ratio of R ¹ ₃ SiO _0.5 units / SiO ₂ units of 0.6 to 1.7 (R ¹ is carbon number 1 To 10 monovalent hydrocarbon groups)
(D) A solventless silicone pressure-sensitive adhesive composition containing a platinum-based catalyst. The total of (A) and (B) components is 90 to 30 parts by mass with respect to the total of 100 parts by mass of components (A), (B) and (C), provided that (B) The molar ratio of SiH groups in the component is such that the molar ratio is 0.5 to 5, and the platinum catalyst of component (C) is 10 to 70 parts by mass (E) contains 5 to 2000 ppm as platinum content. The solvent-free silicone pressure-sensitive adhesive composition according to 1. The component (A) is a polydiorganosiloxane having an alkenyl group-containing organic group having a branch in a molecule having a viscosity of 5 to 1000 mPa · s at 25 ° C. represented by the following average composition formula (1): 3. The solventless silicone pressure-sensitive adhesive composition according to any one of 2 above.
_{(R 3 SiO 1/2) a -} (R 2 SiO) b - (RSiO 3/2) c - (SiO 2) d
(1) (However, R is the C1-C10 monovalent hydrocarbon group which may be same or different, and at least 2 contains an alkenyl group among R. a is an integer greater than or equal to 2, b is (An integer of 3 or more, c and d are integers of 0 or more, and 1 ≦ c + d and a + b + c + d ≦ 400.) The polyorganohydrosiloxane having at least two SiH groups in one molecule, wherein the component (B) is represented by the following average composition formula (2) and / or (3) and has a viscosity at 25 ° C. of 1 to 1000 mPa · s. The solventless silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the composition is a solvent-free silicone pressure-sensitive adhesive composition.

And / or

(R ² is a monovalent hydrocarbon group having no identical or different aliphatic unsaturated bond, α is 0 or 1, p, q is an integer of 0 or more. When α is 0, p is 2 These are the numbers at which the viscosity of this organohydropolysiloxane at 25 ° C. is 1 to 1,000 mPa · s, s is an integer of 2 or more, t is an integer of 0 or more, and 3 ≦ s + t, (It preferably represents an integer of 3 ≦ s + t ≦ 8.) The component (A) is a polydiorganosiloxane having an alkenyl group-containing organic group having a branch in a molecule having a viscosity of 5 to 1000 mPa · s at 25 ° C. represented by the following average composition formula (4): 4. The solventless silicone pressure-sensitive adhesive composition according to any one of 3 above.
_{(R 3 SiO 1/2) C +} 2 - (R 2 SiO) b - (RSiO 3/2) c (4)
(However, R represents the same group as described above. B is an integer of 3 or more, c is an integer of 1 or more, and b + 2c + 2 ≦ 400.) The control agent as component (E) contains 0 to 8.0 parts by mass with respect to 100 parts by mass in total of the components (A), (B), and (C). The solvent-free silicone pressure-sensitive adhesive composition according to any one of the above. An adhesive tape coated on a polyimide film substrate (thickness: 25 μm) is used so that the adhesive strength of the silicone pressure-sensitive adhesive composition shown in any one of claims 1 to 6 is 40 μm. When measured by the 180 ° peel-off adhesive force measurement method shown in JIS Z 0237, it becomes 0.01 to 4.0 N / 25 mm.