JP2011012092A - Addition reaction-curable silicone pressure-sensitive adhesive composition, pressure-sensitive adhesive film using the same, and method for producing pressure-sensitive adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an addition reaction-curable silicone pressure-sensitive adhesive composition that can be stably cured in a short time, such as in less than 1 minute even at a low temperature such as 50-80°C and that can obtain a pressure-sensitive adhesive film excellent in adhesion characteristics and appearance without causing problems, such as deformation or swelling of a substrate upon coating, for a substrate, such as a polyolefin film having poor heat resistance and easy to swell with an organic solvent; a pressure-sensitive adhesive film using the same; and a method for producing the pressure-sensitive adhesive film.SOLUTION: The addition reaction-curable silicone pressure-sensitive adhesive composition is dispersed in an organic solvent, wherein 30-100 mass% of the total is an ether-based solvent. The method for forming a silicone pressure-sensitive adhesive layer includes coating the silicone pressure-sensitive adhesive composition on a substrate such as a polyolefin film and curing the same at a temperature in the range of 50-80°C.

Description

The present invention provides a substrate such as a polyolefin film that can be stably cured in a short time of less than 1 minute at a low temperature of 50 ° C. to 80 ° C., has poor heat resistance, and easily swells with an organic solvent. In contrast, an addition reaction curable silicone pressure sensitive adhesive composition capable of obtaining a pressure sensitive adhesive film excellent in adhesive properties and appearance without causing problems of deformation and swelling of the substrate during coating, The present invention relates to a pressure-sensitive adhesive film using the same and a method for producing a pressure-sensitive adhesive film.

The silicone-based pressure-sensitive adhesive composition has characteristics that it is excellent in electrical insulation, heat resistance, cold resistance, and adhesiveness to various adherends as compared to an acrylic or rubber-based pressure-sensitive adhesive composition. Therefore, it is used in applications such as heat-resistant tape, electrical insulating tape, heat seal tape, plating masking tape, and heat treatment masking tape. These silicone-based pressure-sensitive adhesive compositions are classified into addition reaction curable type, condensation reaction curable type, and peroxide curable type, depending on their curing mechanism. Are preferably used.

Addition reaction curable silicone-based pressure-sensitive adhesive compositions generally include diorganopolysiloxanes in which alkenyl groups are bonded to silicon atoms at both ends of a molecular chain, R ³ SiO _1/2 units (where R is An alkyl group, an alkenyl group, or a hydroxyl group) and an organopolysiloxane resin comprising SiO _4/2 units, an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, a platinum-based catalyst, and an organic solvent The silicone type pressure sensitive adhesive which consists of is known, The composition of the following patent documents 1-4 is illustrated. Moreover, it describes that some silicone type pressure sensitive adhesives (patent documents 5 to 8) can be cured at a relatively low temperature.

The use of these silicone-based pressure-sensitive adhesives dispersed in an organic solvent is generally described in the patent literature relating to silicone-based pressure-sensitive adhesives. In patent literatures and the like, organic solvents are generally widely exemplified, and aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, octane and isoparaffin, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like. Polymerization degree of ketone solvents, ester solvents such as ethyl acetate and isobutyl acetate, ether solvents such as diisopropyl ether and 1,4-dioxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane Examples include halogenated hydrocarbons such as 3-6 cyclic polysiloxanes, trichloroethylene, perchloroethylene, trifluoromethylbenzene, 1,3-bis (trifluoromethyl) benzene, methylpentafluorobenzene, and the like. And is common.

However, the organic solvent suitably used in these patent documents and the like is generally toluene or xylene, and there is no description or suggestion of the influence of the specific organic solvent on the curing characteristics at low temperature. Furthermore, there is no description or suggestion about the influence of these organic solvents on specific substrates.

Furthermore, silicone-based pressure-sensitive adhesive compositions (Patent Documents 5 to 8) whose excellent curing properties at “low temperature” are described as curing of the invention have been proposed. These pressure-sensitive adhesive compositions In practice, however, there is a problem that it takes a long time to cure at low temperatures. That is, for curing of the silicone-based pressure-sensitive adhesive composition, curing conditions of 70 ° C. for 8 hours or 80 ° C. for 4 hours (Patent Document 5) or 80 ° C. or more and 2 minutes or more (Patent Documents 6 to 8) ) Is required, and there is no disclosure of curing an addition reaction curable silicone pressure sensitive adhesive composition at a low temperature of 50 ° C. to 80 ° C. and a short curing time of less than 1 minute. . For this reason, there were problems such as an increase in cycle time in industrial mass production. In particular, these addition reaction curable silicone-based pressure-sensitive adhesive compositions are applied to base materials (films) made of polyolefins such as polypropylene films with poor heat resistance to produce pressure-sensitive adhesive film products such as adhesive tapes. It was not satisfactory enough.

JP-A 63-22886 Japanese Patent Laid-Open No. 04-335083 JP 2006-206890 A JP 2006-193598 A JP 54-48853 A Japanese Patent Laid-Open No. 06-306347 Japanese Patent Laid-Open No. 08-209104 JP 2001-354939 A

The present invention has been made to solve the above problems, and is an addition reaction curable silicone pressure-sensitive adhesive that can be stably cured in a short time of less than 1 minute even at a low temperature of 50 ° C. to 80 ° C. A composition is provided.

Furthermore, the inventors have discovered a new technical problem to be solved by the present invention. As described above, a known addition reaction curable silicone pressure-sensitive adhesive composition is generally dispersed in an organic solvent, preferably toluene or xylene, applied to a substrate, and then heat-cured. However, an addition reaction curable silicone pressure-sensitive adhesive composition dispersed in an aromatic hydrocarbon solvent such as toluene or xylene is applied to a base material (film) made of polyolefin such as polypropylene film having poor heat resistance. Then, the base material made of polyolefin swells with an organic solvent such as toluene, and deformation of the base material occurs during coating. Therefore, it is not possible to obtain a base material made of polyolefin having a pressure-sensitive adhesive layer obtained by curing an addition reaction curable silicone pressure-sensitive adhesive composition without causing problems of deformation and swelling of the base material. It was.

Therefore, the present invention is excellent in adhesive properties and appearance without causing problems of deformation and swelling of the substrate after coating even on a substrate such as a polyolefin film which has poor heat resistance and is easily swollen by an organic solvent. It is an object of the present invention to provide an addition reaction curable silicone pressure sensitive adhesive composition capable of obtaining a pressure sensitive adhesive film, a pressure sensitive adhesive film using the same, and a method for producing the pressure sensitive adhesive film.

The above object is achieved by an addition reaction curable silicone pressure sensitive adhesive composition characterized in that the content of an ether solvent is dispersed in an organic solvent in a specific range. That is, the addition reaction curable silicone pressure-sensitive adhesive composition is characterized in that “30 to 100% by mass of the whole organic solvent is dispersed in an organic solvent that is an ether solvent”. Further, the object is to apply the silicone pressure-sensitive adhesive composition onto a substrate such as a polyolefin film, and to cure the silicone pressure-sensitive adhesive composition within a range of 50 ° C to 80 ° C. Is achieved.

That is, the above purpose is
“[1] An addition reaction curable silicone pressure-sensitive adhesive composition, wherein 30 to 100% by mass of the entire organic solvent is dispersed in an organic solvent that is an ether solvent.
[2] (A) 100 parts by mass of an alkenyl group-containing polydiorganosiloxane,
(B) A polyorganosiloxane containing _0.5 unit of R ₃ SiO and ₂ units of SiO ₂ and having a molar ratio of R ₃ SiO _0.5 unit / SiO ₂ unit of 0.6 to 1.7 (R is carbon number) 1 to 10 monovalent hydrocarbon groups) 1 to 400 parts by mass,
(C) Organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si—H) in one molecule (A) The molar ratio of SiH groups in component (C) to alkenyl groups in component (A) is 2-50. The amount,
(D) Platinum-based catalyst The amount of platinum-based metal is 1 to 5000 ppm with respect to the total amount of components (A) to (C) (E) 30 to 100% by mass of the total organic solvent is the ether solvent. The addition reaction curable silicone pressure-sensitive adhesive composition according to [1], comprising an amount of 10 to 1900 parts by mass with respect to 100 parts by mass in total of the organic solvents (A) to (D). object.
[3] Addition reaction curable silicone pressure-sensitive as described in [1] or [2], wherein the component (E) is an organic solvent in which 50 to 100% by mass of the total organic solvent is a dialkyl ether Adhesive composition.
[4] Addition reaction curable silicone pressure-sensitive adhesive according to any one of [1] to [3], comprising the components (A) to (E) and acetylene alcohols as a reaction control agent. Composition.
[5] A pressure-sensitive adhesive film, wherein a cured layer of the silicone pressure-sensitive adhesive composition according to any one of [1] to [4] is laminated on at least one surface of a polyolefin film. .
[6] Silicone characterized in that the silicone pressure-sensitive adhesive composition according to any one of [1] to [4] is applied on a substrate and cured within a range of 50 ° C to 80 ° C. Method for forming a pressure sensitive adhesive layer.
[7] The silicone pressure-sensitive adhesive composition according to any one of [1] to [4] is applied to at least one surface of a polyolefin film and cured within a range of 50 ° C to 80 ° C. A method for producing a pressure-sensitive adhesive film. Is achieved.

According to the present invention, it is possible to provide an addition reaction curable silicone pressure-sensitive adhesive composition that can be stably cured in a short time of less than 1 minute even at a low temperature of 50 ° C. to 80 ° C. In addition, pressure sensitive adhesion with excellent adhesive properties and appearance without causing problems of deformation and swelling of the substrate after coating, even for substrates such as polyolefin films that are poor in heat resistance and easily swelled with organic solvents A film and a method for producing the pressure-sensitive adhesive film can be provided.

First, the addition reaction curable silicone pressure sensitive adhesive composition of the present invention will be described in detail. The addition reaction curable silicone pressure sensitive adhesive composition of the present invention is characterized in that (E) 30 to 100% by mass of the total organic solvent is dispersed in an organic solvent which is an ether solvent. By using the addition reaction curable silicone pressure-sensitive adhesive composition dispersed in such a specific organic solvent, excellent low temperature curing characteristics can be realized. Furthermore, by using such a specific organic solvent in combination with an organic solvent such as toluene and an addition reaction curable silicone pressure-sensitive adhesive composition, it can also be used for polyolefin films and the like that cause a problem of swelling of the substrate. The technical effect of not causing problems of deformation and swelling of the substrate after coating can be realized.

Said (E) component is an organic solvent whose 30-100 mass% of the whole organic solvent is an ether solvent, It is preferable that 50-100 mass% of the whole is an ether solvent, 75-100 mass% Is more preferably an ether solvent. Most preferably, the organic solvent in which the addition reaction curable silicone pressure-sensitive adhesive composition is dispersed is substantially composed of only an ether solvent, and 90 to 100% by mass of the entire organic solvent is an ether solvent. Most preferably.

The ether solvent is an organic solvent having an ether bond (—O—) in the molecule. Specifically, diethyl ether (boiling point 35 ° C.), dipropyl ether (boiling point 88-90 ° C.), diisopropyl ether. (Boiling point 69 ° C), dibutyl ether (boiling point 140-143 ° C), 1,2-dimethoxyethane (boiling point 82-83 ° C), 1,2-diethoxyethane (?), Diethylene glycol dimethyl ether (boiling point 162 ° C), diethylene glycol Examples include ether solvents such as diethyl ether (boiling point 189 ° C.), diethylene glycol dibutyl ether, propylene glycol dimethyl ether (boiling point 120 ° C.), 1,4-dioxane (boiling point 101 ° C.). In the present invention, ether solvents suitable as the component (E) are dialkyl ethers, and diisopropyl ether is most preferable in view of boiling point, safety, miscibility with water, and the like.

The organic solvent as the component (E) is characterized in that 30 to 100% by mass of the whole is an ether solvent, but may be a mixture with other non-ether solvents. For example, aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, octane and isoparaffin, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and ester solvents such as ethyl acetate and isobutyl acetate Solvents, cyclic polysiloxanes having a polymerization degree of 3-6 such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, trichlorethylene, perchloroethylene, trifluoromethylbenzene, 1,3-bis (tri Examples thereof include mixtures with halogenated hydrocarbons such as (fluoromethyl) benzene and methylpentafluorobenzene. However, as described above, in view of the technical effect of the present invention, it is advantageous not to include an organic solvent other than the ether solvent. Therefore, it is preferable to remove organic solvents other than ether solvents such as toluene and xylene as much as possible at the preparation stage of the composition of the present invention by means such as stripping.

The addition reaction curable silicone pressure-sensitive adhesive composition of the present invention includes an alkenyl group-containing polydiorganosiloxane, a polyorganosiloxane containing R ¹ ₃ SiO _0.5 units and SiO ₂ units, an organohydrogenpolysiloxane, 30-100 mass% of the whole organic solvent which is a platinum catalyst and (E) component contains the organic solvent which is an ether solvent.

The amount of the component (E) is not particularly limited as long as the other components described above can be dispersed uniformly. In general, the total amount of the above-mentioned other components is 100 parts by mass, and the amount of component (E) is preferably 10 to 1900 parts by mass, particularly 20 to 500 parts by mass. preferable. When the component (E) is an organic solvent in which 90 to 100% by mass of the whole is an ether solvent, the amount of the component (E) is 20 to 400 parts by mass with respect to 100 parts by mass of the other components. The amount is particularly preferred.

The addition reaction curable silicone pressure-sensitive adhesive composition of the present invention comprises the component (E) described above, but has low-temperature curing characteristics, adhesive characteristics of pressure-sensitive adhesive layers including adhesive residue, etc. From the viewpoint, an addition reaction curable silicone pressure-sensitive adhesive composition comprising the following components (A) to (E) is preferable. In addition, (E) component and its suitable content are as having already demonstrated.

That is, (A) an alkenyl group-containing polydiorganosiloxane, (B) a R ₃ SiO _0.5 unit and a SiO ₂ unit, and a molar ratio of R ₃ SiO _0.5 unit / SiO ₂ unit is 0.6 to 1 Polyorganosiloxane (R is a monovalent hydrocarbon group having 1 to 10 carbon atoms), (C) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si-H) in one molecule, An addition reaction curable silicone pressure-sensitive adhesive composition comprising (D) a platinum-based catalyst and (E) an organic solvent in which 30 to 100% by mass of the total organic solvent is an ether solvent is preferable.

The component (A) is an alkenyl group-containing polyorganosiloxane, and one or more alkenyl group-containing polyorganosiloxanes represented by the following formula (1) are exemplified.

In the above formula, R ¹ is an unsubstituted or substituted monovalent hydrocarbon group, specifically a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group. , Neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group and other alkyl groups; phenyl group, tolyl group, xylyl group, xylyl group, naphthyl group, biphenylyl group and other aryl groups; cyclopentyl group, cyclohexyl group A cycloalkyl group such as cycloheptyl group; an aralkyl group such as benzyl group, phenylethyl group, phenylpropyl group, methylbenzyl group; and one or more hydrogen atoms of these monovalent saturated hydrocarbon groups are a fluorine atom, chlorine A group substituted with a halogen atom such as an atom or a bromine atom, or a cyano group, such as a chloromethyl group, 2- Lomoethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, chlorophenyl group, fluorophenyl group, cyanoethyl group, 3,3,4,4,5,5,6,6,6-nonafluoro A hexyl group etc. are mentioned. Industrially, R ¹ is particularly preferably a methyl group or a phenyl group.

X is an alkenyl group having 2 to 10 carbon atoms, and examples thereof include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a pentenyl group, a hexenyl group, and a cyclohexenyl group. Preferably it is a C2-C6 alkenyl group, and a vinyl group or a hexenyl group is preferable. R ² is a group selected from R ¹ , X or a silanol group (—OH), and when s = 0, one of R ² is X. R ² is particularly preferably a vinyl group or a hexenyl group.

r is a number of 5 or more, and s is 0 or a positive number. r + s is preferably a number in the range of 100 to 100,000,000. The property of the component (A) at room temperature may be oily or raw rubber, and the viscosity of the component (A) is 50 mPa · s or more, particularly 100 mPa · s or more is preferable. At this time, two or more kinds may be used in combination. Those having a viscosity of 50 mPa · s or less are unsuitable because it is difficult to form a smooth coated surface or pressure-sensitive adhesiveness is hardly exhibited. Moreover, if it is a raw rubber-like thing, it is preferable that the viscosity when it melt | dissolves with toluene so that it may become a 30% density | concentration is 100000 mPa * s or less. In the present invention, the raw rubber-like (A) component is preferably dispersed and blended in the organic solvent which is the above-mentioned (F) component, not toluene.

The component (B) is a polyorganosiloxane that contains R ³ SiO _0.5 units and SiO ₂ units, and the molar ratio of R ³ SiO _0.5 units / SiO ₂ units is 0.6 to 1.7. The molar ratio of R ⁴ ₃ SiO _1/2 units to SiO _4/2 units constituting the component (B) is more preferably 0.5 to 1.0, still more preferably 0.6 to 0.9. Within range. This is because if the molar ratio of R ⁴ ₃ SiO _1/2 units is less than the lower limit, the pressure-sensitive adhesive strength and tack of the resulting pressure-sensitive adhesive may decrease, and the pressure sensitivity obtained when the molar ratio exceeds the upper limit. This is because the cohesive force (holding force) of the adhesive tends to decrease. In addition, RSiO _1.5 units and R ₂ SiO units can be contained in the component (B) within a range not impairing the characteristics of the present invention. The component (B) contains the molecular weight and R ³ SiO. Two or more polyorganosiloxanes having different _0.5 unit / SiO ₂ unit molar ratios can be used in combination.

R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a phenyl group, or a cycloalkyl group having 6 to 10 carbon atoms. , Benzyl group, phenylethyl group, phenylpropyl group and the like. From the viewpoint of low migration of the pressure-sensitive adhesive layer obtained by curing the composition of the present invention, it is preferable that 90 mol% or more of R is an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R of 95 to It is particularly preferable that 100 mol% is a methyl group. Moreover, the polyorganosiloxane containing a silanol group (Si-OH) may be sufficient as (B) component, and it is preferable that silanol group content is 0 to 4.0 weight%.

In the addition reaction curable silicone pressure-sensitive adhesive composition of the present invention, the components (A) and (B) may be simply mixed, or the component (A) has a silanol group. For this, a part or all of the components (A) and (B) can be used in advance as a condensation reaction product. In order to perform the condensation reaction, a mixture of components (A) and (B) dissolved in an organic solvent may be reacted at room temperature or under reflux using an alkaline catalyst. The end point of the condensation reaction can be confirmed by a slight decrease when the viscosity of the condensation reaction product becomes constant or after reaching the maximum value.

The amount of component (B) is preferably in the range of 1 to 400 parts by weight, particularly preferably in the range of 30 to 250 parts by weight, relative to 100 parts by weight of component (A). When the compounding amount of the component (B) is less than the lower limit or exceeds the upper limit, the pressure sensitive adhesiveness may be insufficient.

Component (C) is an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si—H) in one molecule, and is a cross-linking agent for the silicone-based pressure-sensitive adhesive composition according to the present invention. The component (C) is preferably an organohydrogenpolysiloxane represented by the following general formula (2), which undergoes an addition reaction (hydrosilylation reaction) with the silicon atom-bonded alkenyl group contained in the component (A). To cure and form a pressure sensitive adhesive layer. As the component (C), two or more kinds may be used in combination.

In the formula, R ¹ is an unsubstituted or substituted monovalent saturated hydrocarbon group, and examples thereof are the same as those described above. Moreover, p is a positive integer, q is an integer of 2 or more, and p and q satisfy the relationship of 10 ≦ (p + q) ≦ 200. If (p + q) is less than the lower limit, it may volatilize and not sufficiently cure depending on the curing conditions. Moreover, when the said upper limit is exceeded, a gel may produce | generate with bath aging. Furthermore, p and q preferably satisfy the relationship of 0.3 ≦ q / (p + q) ≦ 1. This is because when q / (p + q) is less than the lower limit, curing of the addition reaction curable silicone pressure-sensitive adhesive composition according to the present invention may be insufficient.

The amount of component (C) is such that the molar ratio of silicon atom-bonded hydrogen atoms (SiH) groups in component (C) to alkenyl groups in component (A) is 2 to 50, preferably The amount is 2-20. When the amount of component (C) is less than 2 silicon-bonded hydrogen atoms per alkenyl group relative to the total number of silicon-bonded alkenyl groups present in the system, curing is insufficient, Adhesive residue may be seen on the adherend after heating and holding. In addition, when the blending amount of the component (C) is such that more than 50 silicon atom-bonded hydrogen atoms per alkenyl group with respect to the total number of silicon atom-bonded alkenyl groups present in the system, (C) Ingredients may be readily visible as silicone residues.

The component (D) is a platinum-based catalyst that promotes an addition reaction (hydrosilylation reaction) between a silicon atom-bonded alkenyl group and a silicon atom-bonded hydrogen atom present in the system. Specific examples of preferable platinum-based catalysts include chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid olefin complexes, chloroplatinic acid and ketones complexes, chloroplatinic acid and vinylsiloxane complexes, platinum tetrachloride, Platinum fine powder, alumina or silica carrier with solid platinum supported, platinum black, platinum olefin complex, platinum alkenylsiloxane complex, platinum carbonyl complex, methyl methacrylate resin containing these platinum catalysts, polycarbonate Examples thereof include platinum-based catalysts of thermoplastic organic resin powders such as resins, polystyrene resins and silicone resins.

In this invention, the usage-amount of a component (D) is the range from which the amount of platinum-type metals in a component (D) will be 1-5,000 ppm with respect to the total amount of said component (A) -component (C). The range of 1 to 1,000 ppm is preferable, and the range of 5 to 200 ppm is preferable. When the amount of component (D) used is less than the above lower limit, the curing speed of the silicone-based pressure-sensitive adhesive composition is particularly slow at low temperatures of 50 ° C. to 80 ° C., which may not be practical. Moreover, when the compounding quantity of a component (E) exceeds the said upper limit, problems, such as coloring, may be produced in the obtained silicone type pressure sensitive adhesive composition.

A control agent for adjusting the curing rate such as delaying the addition reaction and suppressing curing at room temperature can be added to the addition reaction curable silicone pressure sensitive adhesive composition according to the present invention. Specifically, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-penten-3-ol, 2-phenyl-3-butyne- Alkyne alcohols such as 2-ol and 1-ethynylcyclohexanol; 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy -1-hexyne, 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne and the like and enyne compounds; 1-ethynyl-1-trimethylsiloxycyclohexane, bis (2,2 -Dimethyl-3-butynoxy) dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-teto Alkenyl siloxane such as methyl 1,3,5,7-tetra-hexenyl cyclotetrasiloxane are exemplified.

The blending amount of the control agent is an effective amount for adjusting the curing rate of the present composition, and is generally 0 to 5.0 with respect to 100 parts by mass in total of the components (A) and (B). It is preferable that it is a mass part, and 0.05-2.0 weight part is especially preferable. If it exceeds 5.0 parts by weight, the curing speed of the resulting silicone-based pressure-sensitive adhesive composition may be remarkably slowed.

Further, the addition reaction curable silicone pressure sensitive adhesive composition according to the present invention includes tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, phenyl as an adhesion promoter. Alkoxy such as trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane Silane compounds can be blended as appropriate.

In addition to the above components, optional components can be added to the addition reaction curable silicone-based pressure-sensitive adhesive composition according to the present invention. For example, non-reactive polyorganosiloxanes such as polydimethylsiloxane and polydimethyldiphenylsiloxane; antioxidants such as phenol, quinone, amine, phosphorus, phosphite, sulfur and thioether; triazole, One or more kinds of light stabilizers such as benzophenone series; flame retardants such as phosphate ester series, halogen series, phosphorus series, and antimony series; cationic surfactants, anionic surfactants, nonionic surfactants, etc. Antistatic agents; dyes, pigments and the like. In particular, the addition of an antistatic agent is preferred.

The silicone-based pressure-sensitive adhesive composition of the present invention can be prepared by mixing the above components (A) to (E) and other optional components as necessary. Uniform mixing of each component is performed by mixing using various stirrers or kneaders.

The composition of the present invention can be produced by simply mixing the components (A) to (E) uniformly. The order of addition of each component is not particularly limited, but when not used immediately after mixing, the mixture comprising component (A), (B), and component (C), component (D), and component (E) ) Can be stored separately, and both can be mixed immediately before use. These pre-cured mixtures each have the advantage that they are excellent in long-term storage stability and do not cause changes in appearance such as turbidity. Even during storage, each component may be dispersed in an organic solvent in which 30 to 100% by mass of the total organic solvent (E) is an ether solvent.

The pressure-sensitive adhesive layer can be obtained by applying the silicone-based pressure-sensitive adhesive composition according to the present invention to various substrates and curing them under predetermined conditions. Moreover, 30-100 mass% of the whole composition (E) organic solvent is disperse | distributed to the organic solvent which is an ether solvent, and the composition is easy to apply | coat uniformly to a base material. Examples of the coating method include dipping, spraying, gravure coating, offset coating, offset gravure, roll coating using an offset transfer roll coater, reverse roll coating, air knife coating, curtain coating using a curtain flow coater, and comma coating. , Meyer bar, and other methods used for forming a known cured layer can be used without limitation. The coating amount is set according to the application, but typically, the thickness of the pressure-sensitive adhesive layer after curing is 2 to 200 μm, and more preferably 2 to 50 μm.

Furthermore, after coating, it can be cured by heating at room temperature or 50 to 200 ° C. to form a pressure-sensitive adhesive layer on the surface of the substrate. The addition reaction curable silicone pressure sensitive adhesive composition of the present invention is particularly excellent in curing characteristics at low temperatures, and the addition reaction curable silicone pressure sensitive adhesive composition is coated on a substrate at 50 ° C. Even when heated at a low temperature of ˜80 ° C., it can be cured stably in a short time of 30 seconds to less than 1 minute (60 seconds). That is, by using the addition reaction curable silicone-based pressure-sensitive adhesive composition of the present invention, a substrate provided with a silicone-based pressure-sensitive adhesive layer is more preferably 55 to 80 ° C. under a temperature condition of 55 ° C. Under a temperature condition of ˜75 ° C., it can be obtained with a short curing time of 30 seconds to less than 1 minute (60 seconds).

Hereinafter, the pressure-sensitive adhesive film according to the present invention will be described in detail.
The pressure-sensitive adhesive film of the present invention is a pressure-sensitive adhesive film having a pressure-sensitive adhesive layer obtained by curing the silicone-based pressure-sensitive adhesive composition according to the present invention on a support film as a base material. It is characterized by.

Support film is polyester, polytetrafluoroethylene, polyimide, polyphenylene sulfide, polyamide, polycarbonate, polystyrene, polypropylene, polyethylene, polyvinyl chloride and other plastic films, aluminum foil, copper foil and other metal foil, Japanese paper, synthetic paper, polyethylene laminate Examples thereof include paper such as paper, cloth, glass fiber, and a composite base material formed by laminating a plurality of these.

In particular, the silicone-based pressure-sensitive adhesive composition of the present invention has excellent low-temperature curing characteristics and does not cause swelling problems, and therefore has poor heat resistance and is easily swelled by an organic solvent such as toluene, and polyolefins such as polypropylene and polyethylene. It is particularly preferable to form a pressure-sensitive adhesive layer by applying it to a support film comprising For a packing tape or the like, a stretched polyolefin film obtained by making a polyolefin-based material such as polypropylene into a transparent film by melt extrusion molding is suitably exemplified as the support film.

The thickness of the film is not particularly limited, but is usually about 5 to 300 μm. Furthermore, in order to improve the adhesion between the support film and the pressure-sensitive adhesive layer, a support film that has been subjected to primer treatment, corona treatment, etching treatment, or plasma treatment may be used. Examples of primer compositions that can be used include condensation type silicone primer compositions containing polydiorganosiloxane having SiOH groups at the ends, polysiloxanes having SiH groups and / or polysiloxanes having alkoxy groups, and condensation reaction catalysts. And an addition-type silicone primer composition containing a polydiorganopolysiloxane having an alkenyl group such as a vinyl group, a polysiloxane having a SiH group, and an addition reaction catalyst.

Even if the pressure-sensitive adhesive film of the present invention is heated at a low temperature of 50 ° C. to 80 ° C. after the silicone pressure-sensitive adhesive composition according to the present invention is applied to the support film, it is 30 seconds. It can be cured stably in a short time of less than ˜1 minute (60 seconds). That is, by using the addition reaction curable silicone-based pressure-sensitive adhesive composition of the present invention, a pressure-sensitive adhesive film, particularly preferably a pressure-sensitive adhesive film having a support film made of polyolefin, is heated to 50 ° C to 80 ° C. It can be obtained with a short curing time of 30 seconds to less than 1 minute (60 seconds) under temperature conditions, more preferably 55 to 75 ° C. Most preferably, a pressure-sensitive adhesive film can be produced under a temperature condition of 55 to 75 ° C. and a curing time of 30 to 50 seconds. The coating method is exemplified by the same method as described above.

The surface opposite to the adhesive layer surface of the support film is preferably subjected to surface treatment such as scratch prevention, stain prevention, fingerprint adhesion prevention, antiglare, antireflection, antistatic treatment and the like. Each of the surface treatments described above may be performed after the adhesive layer is applied to the support film, or the adhesive layer may be applied after the surface treatment.

Examples of the scratch prevention treatment (hard coat treatment) include treatment with a hard coat agent such as an acrylate, silicone, oxetane, inorganic or organic-inorganic hybrid.

Examples of the antifouling treatment include treatment with an antifouling treatment agent such as fluorine, silicone, ceramic, and photocatalyst.

Examples of the antireflection treatment include wet treatment by application of an antireflection agent such as fluorine or silicone, and dry treatment by vapor deposition or sputtering. Examples of the antistatic treatment include a treatment with an antistatic agent such as a surfactant, silicone, organic boron, conductive polymer, metal oxide, or vapor deposition metal.

The pressure-sensitive adhesive film produced using the silicone pressure-sensitive adhesive composition of the present invention has high flexibility and does not involve air bubbles even when attached to a non-planar object. The pressure-sensitive adhesive layer made of the silicone-based pressure-sensitive adhesive composition according to the present invention does not slip or peel by itself after being applied, but it is easy to peel by hand, so that it can be used for various displays as follows. Is preferred. TV receivers, computer monitors, monitors for personal digital assistants, monitors for monitoring, video cameras, digital cameras, mobile phones, personal digital assistants, displays for instrument panels of automobiles, instrument panels for various equipment, devices and equipment It can be used for various flat panel displays (FPD) for displaying characters, symbols, and images, such as displays, automatic ticket vending machines, and automatic teller machines. Devices include display devices such as CRT displays, liquid crystal displays, plasma displays, organic EL displays, inorganic EL displays, LED displays, surface electrolytic displays (SEDs), field emission displays (FEDs), and touch panels using these devices. Application is possible. The film of the present invention is used for such purposes as preventing damage to the display surface, preventing dirt, preventing fingerprint adhesion, preventing charging, preventing reflection, and preventing peeping.

In addition, the silicone pressure-sensitive adhesive composition of the present invention is excellent in low-temperature curing characteristics and suppresses swelling with respect to the polyolefin film, so that it can produce pressure-sensitive adhesive tapes, sheets, labels, etc. After coating on a film or release paper and curing, an adhesive tape, a sheet, a label, or the like may be produced by a transfer method that is bonded to the substrate. In particular, the silicone pressure-sensitive adhesive composition of the present invention is applied to an oriented polypropylene (OPP) tape, and is useful when producing an OPP tape for packaging having a silicone pressure-sensitive adhesive layer. That is, it exhibits excellent adhesive strength without impairing properties such as water resistance, moisture resistance, and transparency of stretched polypropylene (OPP) tape, and does not cause adhesive residue, so it is suitably used as an OPP tape for packaging. be able to.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example. In the following examples, the base material swelling property, curability and adhesive strength of the silicone-based pressure-sensitive adhesive composition were measured by the following methods. In Examples and Comparative Examples, Me represents a methyl group, and Vi represents a vinyl group. Moreover,% represents weight%.

[Substrate swelling]
The silicone pressure-sensitive adhesive composition is coated on a support made of a polyolefin base material so that the pressure-sensitive adhesive layer after curing has a thickness of about 5 μm, It was visually examined whether shrinkage / winding was observed.
When no deformation was observed, it was evaluated as “no swelling”.
Coating was possible, but when slight deformation was observed, it was evaluated as “slightly swollen”.
When deformation / shrinkage / winding of the substrate was observed at the coating stage, it was evaluated as “swelling”, and subsequent curability was not evaluated.

[Curing property]
After coating the silicone pressure-sensitive adhesive composition on a support made of a polyolefin base material so that the cured pressure-sensitive adhesive layer has a thickness of about 5 μm, this was applied at 40 ° C. to 90 ° C. An adhesive sheet was prepared by heating at a predetermined temperature for 40 seconds. Next, the surface of the pressure-sensitive adhesive sheet was rubbed with a finger to examine whether it was cured.
○: Smear is not seen at all. (Hardened)
X: Smear is seen. (Insufficient curing)
[State of substrate after curing]
After the pressure-sensitive adhesive layer was formed by heat curing, it was visually examined whether softening / deformation of the substrate was observed. If no softening / deformation was seen, it was evaluated as “no change”.

[Adhesive force]
A silicone pressure-sensitive adhesive composition is coated on a support made of a polyolefin substrate so that the cured pressure-sensitive adhesive layer has a thickness of about 5 μm, and then heated at 65 ° C. for 40 seconds. Thus, an adhesive sheet was prepared. Next, this adhesive tape was cut into a width of 25 mm to prepare an adhesive tape, and was bonded to an adherend made of a mirror surface stainless steel plate (SUS304) using a 2 kgf rubber roller. Then, it left still for 30 minutes at room temperature. The adhesive strength was measured by a 180 ° peeling method using a low-speed (300 mm / min) tensile tester.

[Example 1]
(A) Diorganopolysiloxane represented by the following average structural formula (average molecular weight 525,000, vinyl% = 0.12) 29.8 parts by weight R ¹ Me ₂ SiO (Me ₂ SiO) ₅₀₀₀ (MeViSiO) ₂₃ SiOMe ₂ R ¹
(R ¹ is an OH group or a Vi group)

(B) An _{origanopolysiloxane} resin composed of Me ₃ SiO _1/2 units and SiO _4/2 units represented by the following average structural formula (the ratio of Me ₃ SiO _1/2 units to SiO _4/2 units is _0.00 ). 13.7 parts by weight of a xylene solution containing 81.6% by weight of 8/1)

(C) Methyl hydrogen / dimethylpolysiloxane having a viscosity of 55 mPa · s represented by the following average structural formula and having both ends blocked with trimethylsiloxy groups (content of silicon atom-bonded hydrogen atoms: 1.0 wt%) 1 0.0 part by weight Me ₃ SiO (Me ₂ SiO ₂₄ (MeHSiO) ₅₀ SiMe ₃

(D) The platinum metal in the 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of chloroplatinic acid is based on the total amount of the above components (A) to (C). Amount of 50ppm in unit

(E1) 115.2 parts by weight of isopropyl ether

(F) 1-ethynyl-1-cyclohexanol 0.16 parts by weight

Was mixed to prepare a silicone-based pressure-sensitive adhesive composition P1 having an organopolysiloxane component of 25% by weight. Next, this silicone-based pressure-sensitive adhesive composition P1 was applied to a polypropylene base material and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1. Moreover, the adhesive force was 5 [g / 25mm].

[Example 2]
In the same manner as in Example 1 except that a mixed solvent consisting of 55.2 parts of hexane and 60.0 parts of isopropyl ether was used instead of the (E1) component of Example 1, the organopolysiloxane component was 25 A silicone-based pressure-sensitive adhesive composition P2 having a weight% was prepared. Next, this silicone type pressure sensitive adhesive composition P2 was applied to a polypropylene base material and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1.

[Example 3]
In the same manner as in Example 1 except that a mixed solvent consisting of 79.2 parts of hexane and 36.0 parts of isopropyl ether was used instead of the (E1) component of Example 1, the organopolysiloxane component was 25 A silicone-based pressure-sensitive adhesive composition P3 having a weight percent was prepared. Next, this silicone type pressure-sensitive adhesive composition P3 was applied to a polypropylene base material and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1.

[Example 4]
In the same manner as in Example 1 except that a mixed solvent consisting of 79.2 parts of toluene and 36.0 parts of isopropyl ether was used instead of the (E1) component of Example 1, the organopolysiloxane component was 25 A silicone-based pressure-sensitive adhesive composition P4 having a weight% was prepared. Next, this silicone type pressure sensitive adhesive composition P4 was applied to a polypropylene substrate and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1.

[Example 5]
(A) Diorganopolysiloxane represented by the following average structural formula (average molecular weight 525,000, vinyl% = 0.06) 22.0 parts by weight R ¹ Me ₂ SiO (Me ₂ SiO) ₅₀₀₀ (MeViSiO) ₁₂ SiOMe ₂ R ¹
(R ¹ is an OH group or a Vi group)

(B) An _{origanopolysiloxane} resin composed of Me ₃ SiO _1/2 units and SiO _4/2 units represented by the following average structural formula (the ratio of Me ₃ SiO _1/2 units to SiO _4/2 units is _0.00 ). 22.7 parts by weight of a xylene solution containing 81.6% by weight of 8/1) in terms of solid content

(C) Methyl hydrogen / dimethylpolysiloxane having a viscosity of 55 mPa · s represented by the following average structural formula and having both ends blocked with trimethylsiloxy groups (content of silicon atom-bonded hydrogen atoms: 1.0 wt%) 1 0.0 part by weight Me ₃ SiO (Me ₂ SiO ₂₄ (MeHSiO) ₅₀ SiMe ₃

(D) The platinum metal in the 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of chloroplatinic acid is based on the total amount of the above components (A) to (C). Amount of 50ppm in unit

(E1) 115.2 parts by weight of isopropyl ether

(F) 1-ethynyl-1-cyclohexanol 0.16 parts by weight

Was mixed to prepare a silicone-based pressure-sensitive adhesive composition P5 having an organopolysiloxane component of 25% by weight. Next, this silicone type pressure sensitive adhesive composition P5 was applied to a polypropylene substrate and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1. Moreover, the adhesive force was 290 [g / 25mm].

[Example 6]
In Example 5, an adhesive tape was prepared in the same manner as in Example 5 except that a polyethylene substrate was used instead of the polypropylene substrate. About the obtained adhesive tape, the result of having evaluated base material swelling property and sclerosis | hardenability by the said method is shown in Table 1. Moreover, the adhesive force was 90 [g / 25mm].

[Comparative Example 1]
A silicone-based pressure-sensitive adhesive having an organopolysiloxane component of 25% by weight in the same manner as in Example 1 except that 115.2 parts of (E-C1) hexane was used instead of the (E1) component of Example 1. Agent composition C1 was prepared. Next, it applied to the polypropylene base material using this silicone type pressure sensitive adhesive composition C1, and made it harden | cure at 65 degreeC-40 second, and created the adhesive tape. Table 1 shows the results of evaluation of substrate swelling and curability by the above method.

[Comparative Example 2]
A silicone-based pressure-sensitive adhesive having an organopolysiloxane component of 25% by weight in the same manner as in Example 1 except that 115.2 parts of (E-C2) toluene was used in place of the (E1) component of Example 1. Agent composition C2 was prepared. Next, this silicone-based pressure-sensitive adhesive composition C2 was applied to a polypropylene substrate and cured at 65 ° C. for 40 seconds to prepare an adhesive tape. Table 1 shows the results of evaluation of substrate swelling and curability by the above method.

[Comparative Example 3]
A silicone-based pressure-sensitive adhesive having an organopolysiloxane component of 25% by weight in the same manner as in Example 1 except that 115.2 parts of (E-C3) ethyl acetate was used in place of the (E1) component of Example 1. Adhesive composition C3 was prepared. Next, it applied to the polypropylene base material using this silicone type pressure sensitive adhesive composition C3, it was made to harden | cure at 65 degreeC-40 second, and the adhesive tape was created. Table 1 shows the results of evaluation of substrate swelling and curability by the above method.

[Example 7]
The pressure-sensitive adhesive tape was prepared by coating the polypropylene base material using the silicone-based pressure-sensitive adhesive composition P1 prepared in Example 1 and curing it at 40 ° C. for 40 seconds. Table 1 shows the results of evaluation of substrate swelling and curability by the above method.

[Example 8]
The pressure-sensitive adhesive tape was prepared by coating the polypropylene base material using the silicone-based pressure-sensitive adhesive composition P1 prepared in Example 1 and curing it at 80 ° C. for 40 seconds. The substrate swelling property and curability were evaluated by the above methods.

[Example 9]
The pressure-sensitive adhesive tape was prepared by coating on a polypropylene base material using the silicone-based pressure-sensitive adhesive composition P1 prepared in Example 1 and curing at 90 ° C. for 40 seconds. The substrate swelling property and curability were evaluated by the above methods.

（＊）（Ｂ）成分中のキシレンを除く。また、表中、溶媒の略号等は、以下の通り。
IPE：イソプロピルエーテル
Hexane：ヘキサン
Toluene：トルエン
acetic ether：酢酸エチル

(*) Excluding xylene in component (B). In the table, the abbreviations of the solvents are as follows.
IPE: Isopropyl ether
Hexane: Hexane
Toluene: Toluene
acetic ether: ethyl acetate

Claims (7)

An addition reaction curable silicone pressure-sensitive adhesive composition, wherein 30 to 100% by mass of the total organic solvent is dispersed in an organic solvent which is an ether solvent. (A) 100 parts by mass of an alkenyl group-containing polydiorganosiloxane,
(B) A polyorganosiloxane containing _0.5 unit of R ₃ SiO and ₂ units of SiO ₂ and having a molar ratio of R ₃ SiO _0.5 unit / SiO ₂ unit of 0.6 to 1.7 (R is carbon number) 1 to 10 monovalent hydrocarbon groups) 1 to 400 parts by mass,
(C) Organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si—H) in one molecule (A) The molar ratio of SiH groups in component (C) to alkenyl groups in component (A) is 2-50. The amount,
(D) Platinum-based catalyst The amount of platinum-based metal is 1 to 5000 ppm with respect to the total amount of components (A) to (C) (E) 30 to 100% by mass of the total organic solvent is the ether solvent. 2. The addition reaction curable silicone pressure-sensitive adhesive composition according to claim 1, comprising an amount of 10 to 1900 parts by mass with respect to 100 parts by mass in total of the organic solvents (A) to (D). object. The addition reaction curable silicone pressure-sensitive adhesive composition according to claim 1 or 2, wherein the component (E) is an organic solvent in which 50 to 100% by mass of the total organic solvent is a dialkyl ether. object. The addition reaction curable silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, comprising the components (A) to (E) and an acetylene alcohol as a reaction control agent. A pressure-sensitive adhesive film, wherein a cured layer of the silicone pressure-sensitive adhesive composition according to any one of claims 1 to 4 is laminated on at least one surface of a polyolefin film. A silicone pressure-sensitive adhesive layer according to any one of claims 1 to 4, wherein the silicone pressure-sensitive adhesive composition according to any one of claims 1 to 4 is applied onto a substrate and cured within a range of 50 ° C to 80 ° C. Forming method. A pressure-sensitive adhesive, wherein the silicone pressure-sensitive adhesive composition according to any one of claims 1 to 4 is applied to at least one surface of a polyolefin film and cured within a range of 50 ° C to 80 ° C. A method for producing a film.