JP7220138B2 - Substrate bonding method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for bonding substrates, and more particularly to a method for bonding multilayer substrates using an ultraviolet addition-curable liquid silicone rubber adhesive.

Acrylic-based adhesive used when bonding another substrate such as a touch panel, cover glass, or cover film to a substrate such as a liquid crystal module (LCM) or flexible printed wiring board (FPC) of an image display device. Resins, urethane resins, and silicone adhesives are used. Bonding with such a curable adhesive eliminates gaps, improves display recognizability and durability, and suppresses glare of sunlight and the like. At present, resins such as acrylic resins are used for these bonding materials. drugs are receiving attention.

A touch panel device has a light-shielding portion derived from a support, and there are cases where poor curing of an adhesive applied under the light-shielding portion poses a problem. As a method for solving this problem, the development of addition-curable adhesives for image display devices, particularly addition-curable materials in which the addition reaction is triggered by ultraviolet irradiation instead of heating, is being actively developed (Patent Documents 1 and 2). ).

However, ultraviolet addition-curable materials may hinder curing of the addition-curing reaction by irradiation with ultraviolet rays in image display device members to be laminated together, particularly polarizing plates, touch panels, and display panels. A phenomenon is observed in which the hardening does not occur.

JP 2014-169412 A JP 2015-110752 A

The present invention has been made in view of the above circumstances, and suppresses curing inhibition caused by the image display device member when bonding the glass panel and the image display device member using an ultraviolet addition curing type liquid silicone rubber adhesive. It is an object of the present invention to provide a substrate bonding method that provides a multilayer substrate with good adhesiveness.

In order to solve the above problems, the present invention provides a method for bonding a pair of opposing glass panels and an image display device member using an ultraviolet addition-curable liquid silicone rubber adhesive, comprising:
The ultraviolet addition-curable liquid silicone rubber adhesive contains a photoactive hydrosilylation reaction catalyst,
applying the ultraviolet addition-curable liquid silicone rubber adhesive to the glass panel to form an adhesive layer; irradiating the adhesive layer with ultraviolet rays to activate the photoactive hydrosilylation reaction catalyst; and a bonding step of laminating the image display device member via the adhesive layer after irradiation.

According to the above bonding method, after applying an ultraviolet addition-curable liquid silicone rubber adhesive to a glass panel and irradiating ultraviolet rays in advance to initiate an addition reaction, the ultraviolet irradiation may inhibit the addition curing reaction. By bonding to the device member, it is possible to suppress curing inhibition from the image display device member and improve the adhesiveness to the substrate.

In this case, as the ultraviolet addition-curable liquid silicone rubber adhesive,
(A) an organopolysiloxane having a viscosity at 25° C. of 50 to 1,000,000 mPa·s and containing at least two alkenyl groups per molecule;
(B) A linear organohydrogenpolysiloxane having hydrogen atoms (Si—H groups) directly bonded to silicon atoms only at both ends of the molecular chain, or having at least two Si—H groups in one molecule Organohydrogenpolysiloxane which is a mixture of organohydrogenpolysiloxane and linear organohydrogenpolysiloxane having Si—H groups only at one end and/or only at both ends of the molecular chain: [ number of Si—H groups]/[number of alkenyl groups]=0.5 to 2.5,
as well as,
(C) one or more photoactivated hydrosilylation reaction catalysts selected from the following group: (1,5-cyclooctadienyl)diphenylplatinum complex, (1,5-cyclooctadienyl)dipropylplatinum complex, (2 ,5-norboradiene)dimethylplatinum complex, (2,5-norboradiene)diphenylplatinum complex, (cyclopentadienyl)dimethylplatinum complex, (methylcyclopentadienyl)diethylplatinum complex, (trimethylsilylcyclopentadienyl)diphenylplatinum complex, (methylcycloocta-1,5-dienyl) diethylplatinum complex, (cyclopentadienyl)trimethylplatinum complex, (cyclopentadienyl)ethyldimethylplatinum complex, (cyclopentadienyl)acetyldimethylplatinum complex, ( methylcyclopentadienyl)trimethylplatinum complex, (methylcyclopentadienyl)trihexylplatinum complex, (trimethylsilylcyclopentadienyl)trimethylplatinum complex, (dimethylphenylsilylcyclopentadienyl)triphenylplatinum complex, (cyclopentadienyl) enyl)dimethyltrimethylsilylmethylplatinum complex and bis(β-diketonato)platinum complex: an amount of 0.1 to 1,000 ppm as the mass of platinum with respect to the total mass of (A) and (B);
including
It is preferable to use one having a viscosity of 10 to 200,000 mPa·s at 25°C.

When the UV addition-curable liquid silicone rubber adhesive is used, it can be cured in a few minutes to several tens of minutes under mild temperature conditions of 100° C. or less, and a cured product with good mechanical and optical properties can be obtained. In particular, it can be cured in a short time of several minutes to several hours even at room temperature, and can maintain a low hardness with little change in hardness even after a heat resistance test, thereby suppressing stress on an image display device.

Furthermore, (B) preferably contains an organohydrogenpolysiloxane having an epoxy group, acryloxy group, methacryloxy group, alkoxysilyl group or bisphenol skeleton.

Use of such a component (B) is preferable because it provides excellent adhesiveness.

The bonding method of the present invention is particularly suitable when the surface of the image display device member to be bonded to the glass panel is a polarizing plate, a touch panel, or a display panel.

As described above, according to the bonding method of the present invention, it is possible to suppress curing inhibition caused by image display device members and provide a multilayer substrate having good adhesiveness.

1 is a schematic diagram of a plane tensile bond strength test in an example of the present invention; FIG.

As described above, there has been a demand for development of an adhesion method that suppresses curing inhibition caused by image display device members and provides a multilayer substrate with good adhesiveness.

As a result of intensive studies on the above problems, the inventors of the present invention applied an ultraviolet addition-curable liquid silicone rubber adhesive to a glass panel, irradiated with ultraviolet rays in advance to initiate an addition reaction, and then added and cured the adhesive with ultraviolet irradiation. The present inventors have found that the above problems can be solved by laminating the composition to an image display device member that may inhibit curing of the reaction, and have completed the present invention.

That is, the present invention relates to a method of bonding a pair of opposed glass panels and an image display device member using an ultraviolet addition-curable liquid silicone rubber adhesive, wherein the ultraviolet addition-curable liquid silicone rubber adhesive is a photoactivatable adhesive. applying the ultraviolet addition-curable liquid silicone rubber adhesive to the glass panel to form an adhesive layer; and a bonding step of laminating the image display device member via the adhesive layer after ultraviolet irradiation.

Although the present invention will be described in detail below, the present invention is not limited thereto.

The present invention comprises the steps of: (i) applying an ultraviolet addition-curable liquid silicone rubber adhesive containing a photoactive hydrosilylation reaction catalyst to a glass panel to form an adhesive layer; and (ii) irradiating the adhesive layer with ultraviolet rays. and (iii) a bonding step of laminating the image display device member via the adhesive layer after UV irradiation. Moreover, in addition to the above steps (i) to (iii), a pretreatment step, a curing step, and the like can be further included, if necessary.

When an image display device member such as a polarizing plate and a liquid crystal module is irradiated with ultraviolet rays, substances such as benzyl acrylate and benzyl aldehyde derived from protective coatings of the image display device member may be generated. It is believed that these substances inhibit curing in the addition reaction using a platinum catalyst. According to the bonding method of the present invention, an ultraviolet addition-curable liquid silicone rubber adhesive is applied to a glass panel, and after the addition reaction is initiated by irradiating ultraviolet rays in advance, the glass panel is bonded to the image display device member, thereby achieving the above-described effect. Good adhesion can be obtained by avoiding the generation of such curing inhibitors.

[Ultraviolet addition-curing liquid silicone rubber adhesive]
As the ultraviolet addition-curable liquid silicone rubber adhesive used in the present invention,
(A) an organopolysiloxane having a viscosity at 25° C. of 50 to 1,000,000 mPa·s and containing at least two alkenyl groups in one molecule; (B) a Si—H group at both ends of the molecular chain; A linear organohydrogenpolysiloxane having only one end of the molecular chain, or an organohydrogenpolysiloxane having at least two Si—H groups in one molecule and Si—H groups only at one end of the molecular chain and / or at both ends A mixture of linear organohydrogenpolysiloxanes having only the terminals, and (C) a photoactive catalyst selected from a platinum complex having a cyclic diene compound or the like as a ligand, having a viscosity of 10 to 200 at 25°C. ,000 mPa·s is preferably used. In addition, in the following description, the viscosity is a value measured by a rotational viscometer at 25°C.

[(A) Component]
The organopolysiloxane of component (A) contains at least 2, preferably 2 to 6, silicon-bonded alkenyl groups (hereinafter referred to as "silicon-bonded alkenyl groups") per molecule. .
The silicon-bonded alkenyl group preferably has 2 to 8 carbon atoms, more preferably 2 to 4 carbon atoms. Specific examples thereof include vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group and the like, and vinyl group is particularly preferred.

Examples of the organic group bonded to a silicon atom other than the above-mentioned alkenyl group include unsubstituted or substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms and having no aliphatic unsaturated bonds. is exemplified by linear alkyl groups, branched alkyl groups, cyclic alkyl groups, aryl groups, aralkyl groups, halogenated alkyl groups and the like. Preferred examples of linear alkyl groups include those having 1 to 10 carbon atoms such as methyl, ethyl, propyl, hexyl, octyl and decyl groups, more preferably 1 to 10 carbon atoms. 6. Preferred examples of branched chain alkyl groups include those having 1 to 10 carbon atoms such as isopropyl group, isobutyl group, tert-butyl group and 2-ethylhexyl group, and more preferably those having 1 to 6 carbon atoms. . Preferred examples of the cyclic alkyl group include those having 3 to 10 carbon atoms such as cyclopentyl group and cyclohexyl group. Preferred examples of the aryl group include those having 6 to 10 carbon atoms such as phenyl group and tolyl group. Preferred examples of aralkyl groups include those having 7 to 10 carbon atoms such as 2-phenylethyl group and 2-methyl-2-phenylethyl group. Preferred examples of halogenated alkyl groups include those having 1 to 10 carbon atoms such as 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, 2-(heptadecafluorooctyl)ethyl. and more preferably 1 to 6.

Among these, straight-chain alkyl groups and aryl groups are preferred, straight-chain alkyl groups and aryl groups having 1 to 6 carbon atoms are more preferred, and methyl and phenyl groups are particularly preferred.

The viscosity of component (A) at 25° C. is preferably in the range of 50 to 1,000,000 mPa·s, more preferably in the range of 1,000 to 100,000 mPa·s. When the viscosity is within this range, it is easy to ensure the handling workability of the composition, and it is easy to ensure good physical properties of the cured product of the composition.

The molecular structure of component (A) is not particularly limited. It is linear with Component (A) may be a single polymer having these molecular structures, a copolymer having these molecular structures, or a mixture of two or more of these polymers.

Component (A) includes, for example, dimethylpolysiloxane having both molecular chain ends blocked with dimethylvinylsiloxy groups, dimethylpolysiloxane having both molecular chain ends blocked with methylphenylvinylsiloxy groups, dimethylsiloxane/methylphenyl having both molecular chain ends blocked with dimethylvinylsiloxy groups. Siloxane copolymer, both molecular chain ends dimethylvinylsiloxy group-blocked dimethylsiloxane/methylvinylsiloxane copolymer, molecular chain both ends silanol group-blocked dimethylsiloxane/methylvinylsiloxane copolymer, molecular chain both ends silanol group-blocked dimethylsiloxane・Methylvinylsiloxane/methylphenylsiloxane copolymer, dimethylsiloxane/methylvinylsiloxane copolymer with trimethylsiloxy group-blocked at both molecular chain ends, methyl (3,3,3-trifluoropropyl) with dimethylvinylsiloxy group-blocked at both molecular chain ends ) polysiloxane, a siloxane unit represented by the formula: (CH ₃ ) ₃ SiO _1/2 and a siloxane unit represented by the formula: (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 and a siloxane unit represented by the formula: CH ₃ Examples thereof include organosiloxane copolymers comprising siloxane units represented by SiO _3/2 and siloxane units represented by the formula: (CH ₃ ) ₂ SiO _2/2 .

This organopolysiloxane (A) basically consists of a siloxane skeleton and does not contain an alkoxy group.
The (A) component organopolysiloxane may be used alone or in combination of two or more.

[(B) Component]
The organohydrogenpolysiloxane of component (B) is a component that undergoes an addition curing reaction with component (A). This organohydrogenpolysiloxane is a linear organohydrogenpolysiloxane having hydrogen atoms (Si—H groups) directly bonded to silicon atoms only at both ends of the molecular chain, or at least two Si atoms in one molecule. an organohydrogenpolysiloxane which is a mixture of an organohydrogenpolysiloxane having a —H group and a straight-chain organohydrogenpolysiloxane having Si—H groups only at one end and/or at both ends of the molecular chain; be. The organohydrogenpolysiloxane contains an organohydrogenpolysiloxane having at least two hydrogen atoms (Si—H groups) directly bonded to silicon atoms in one molecule, and the Si—H groups are present on one side of the molecular chain. It may contain a linear organohydrogenpolysiloxane having only the ends or only both ends.

The groups bonded to silicon atoms other than hydrogen atoms in component (B) include unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds of 1 to 10 carbon atoms, carbon atoms or Epoxy groups bonded to silicon atoms via oxygen atoms (e.g., γ-glycidoxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group, etc.) and acryloxy groups (e.g., γ-acryloxypropyl group etc.) or a methacryloxy group (e.g., γ-methacryloxypropyl group, etc.); an alkoxysilyl group (e.g., an ester structure, a urethane structure, an ether structure, etc.) via an alkylene group that may contain 1 or 2 ether structures. trimethoxysilyl group, triethoxysilyl group, alkoxysilyl group such as methyldimethoxysilyl group), linking group having a bisphenol skeleton, and the like.

Examples of unsubstituted or substituted monovalent hydrocarbon groups excluding aliphatic unsaturated bonds having 1 to 10 carbon atoms include straight-chain alkyl groups, branched-chain alkyl groups, cyclic alkyl groups, aryl groups, aralkyl groups, halogen Alkyl groups are exemplified. Linear alkyl groups and aryl groups having 1 to 6 carbon atoms are preferred, and methyl and phenyl groups are particularly preferred.

Examples of the organohydrogenpolysiloxane having at least two Si—H groups in one molecule include those having a linear, branched, cyclic, dendritic (dendrimer) structure, epoxy group, Organohydrogenpolysiloxane having an acryloxy group, a methacryloxy group, an alkoxysilyl group or a bisphenol skeleton is preferable because of its excellent adhesion. Specific examples of such organohydrogenpolysiloxanes include those represented by the following formulas.

（式中、各シロキサン単位の配列は任意であってよい。）

(In the formula, the arrangement of each siloxane unit may be arbitrary.)

Specific examples of linear organohydrogenpolysiloxanes having Si—H groups only at one end or only at both ends of the molecular chain include dimethylpolysiloxane blocked with dimethylhydrogensiloxy groups at both ends of the molecular chain; dimethylsiloxane/methylphenylsiloxane copolymer with dimethylhydrogensiloxy group-blocked at both ends, methylphenylpolysiloxane with dimethylhydrogensiloxy group-blocked at both ends of molecular chain, dimethylpolysiloxane with dimethylhydrogensiloxy group-blocked at one end of molecular chain, dimethylpolysiloxane at one end of molecular chain A dimethylhydrogensiloxy group-blocked dimethylsiloxane/methylphenylsiloxane copolymer, a dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane at one end of a molecular chain, and the like can be mentioned.

The component (B) may be used in combination of two or more, or may be used singly. A linear organohydrogenpolysiloxane having Si—H groups only at both ends of the molecular chain is also an organohydrogenpolysiloxane having at least two Si—H groups in one molecule, and can be used alone. can.

The viscosity of component (B) at 25° C. is not particularly limited, but is preferably in the range of 1 to 200 mPa·s. When the viscosity is within this range, it is easy to ensure the handling workability of the composition, and it is easy to ensure good physical properties of the cured product of the composition. This viscosity is a value measured by a rotational viscometer.

The compounding ratio of component (B) to component (A) preferably satisfies [number of Si—H groups]/[number of alkenyl groups]=0.5 to 2.5. When the ratio is within such a range, the curability of the composition is excellent, the hardness of the resulting cured product is appropriate, and stress is less likely to be applied to the member.

[(C) Component]
Component (C) is a photoactivatable hydrosilylation reaction catalyst which, when activated by irradiation with ultraviolet rays, causes silicon-bonded alkenyl groups in component (A) to react with silicon-bonded hydrogen atoms in component (B). It has a catalytic action that promotes the hydrosilylation reaction.

In the present invention, the component (C) is not particularly limited as long as it has activity as the above catalyst, but a platinum complex having a cyclic diene compound as a ligand is preferable, and (1,5-cyclooctadienyl)diphenyl platinum complex, (1,5-cyclooctadienyl) dipropyl platinum complex, (2,5-norboradiene) dimethyl platinum complex, (2,5-norboradiene) diphenyl platinum complex, (cyclopentadienyl) dimethyl platinum complex, ( methylcyclopentadienyl)diethylplatinum complex, (trimethylsilylcyclopentadienyl)diphenylplatinum complex, (methylcycloocta-1,5-dienyl)diethylplatinum complex, (cyclopentadienyl)trimethylplatinum complex, (cyclopentadienyl) enyl)ethyldimethylplatinum complex, (cyclopentadienyl)acetyldimethylplatinum complex, (methylcyclopentadienyl)trimethylplatinum complex, (methylcyclopentadienyl)trihexylplatinum complex, (trimethylsilylcyclopentadienyl)trimethylplatinum complex , (dimethylphenylsilylcyclopentadienyl)triphenylplatinum complex, (cyclopentadienyl)dimethyltrimethylsilylmethylplatinum complex and bis(β-diketonato)platinum complex with one or more photoactivated hydrosilylation catalysts Preferably.

The content of component (C) is preferably 0.1 to 1,000 ppm as platinum metal mass with respect to the total mass of components (A) and (B), from the viewpoint of curability and storage stability of the composition. and more preferably in an amount of 5 to 500 ppm.

[Other ingredients]
In addition to the above components (A) to (C), the composition of the present invention may contain other components depending on the purpose of the present invention. Other components include, for example, reaction control agents, adhesion aids, inorganic fillers, and the like, and these may be used alone or in combination of two or more.

The reaction control agent is not particularly limited as long as it is a compound that controls the reaction rate of the curing reaction with respect to the photoactive platinum complex curing catalyst of component (C) and further improves the storage stability of the composition. Conventionally known compounds can also be used, such as acetylene compounds, various nitrogen compounds, organic phosphorus compounds, and the like. Specifically, 1-ethynyl-1-cyclohexanol, 3-butyn-1-ol, acetylene compounds such as dimethylbis(1,1-dimethyl-2-propynyloxy)silane, triallyl isocyanurate and triallyl isocyanate Examples include various nitrogen compounds such as nurate derivatives, organic phosphorus compounds such as triphenylphosphine, and the like.

It is preferable to adjust the amount of the reaction control agent to an optimum amount for each reaction control agent to be used, since the reaction control agent has a different degree of effect of controlling the reaction rate of the curing reaction depending on the chemical structure. Workability and productivity can be improved by adding an optimum amount of the reaction control agent.

It is also possible to add an organic compound that does not contain an organosiloxane skeleton as an adhesion aid. Examples include allyl glycidyl ether, allyl benzoate, bisphenol A diallyl ether, KAYARAD R-604 (Nippon Kayaku Co., Ltd.) and the like.

Examples of inorganic fillers include crystalline silica, hollow fillers, silsesquioxane, fumed titanium dioxide, magnesium oxide, zinc oxide, aluminum hydroxide, calcium carbonate, zinc carbonate, glass fibers, and other inorganic fillers; Inorganic fillers surface-hydrophobicized with organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds and low-molecular-weight siloxane compounds; silicone rubber powders; silicone resin powders;

While the addition of inorganic fillers contributes to the improvement of the mechanical properties of the resulting silicone cured product, it may impede the transmission of ultraviolet rays and reduce curability. .

The ultraviolet addition-curable liquid silicone rubber adhesive of the present invention has a viscosity at 25°C of 10 to 200,000 mPa·s, preferably 10 to 120,000 mPa·s, more preferably 1,000 to 50,000 mPa. · s. If the viscosity is within the above range, the composition will not flow and spread excessively, making it difficult to stay on the substrate with a constant film thickness, and coating with a device will be easy.

Furthermore, the ultraviolet addition-curable liquid silicone rubber adhesive of the present invention can be suitably used without blending an organic solvent. Therefore, the composition may be diluted to an arbitrary concentration with an organic solvent such as toluene or xylene.

In principle, the ultraviolet addition-curable liquid silicone rubber adhesive of the present invention is used for laminating substrates activated by a pretreatment process added in known processes such as primer treatment, plasma treatment, and excimer light treatment. can also be used for

Examples of methods for curing the ultraviolet addition-curable liquid silicone rubber adhesive of the present invention include irradiating the liquid silicone composition with ultraviolet rays and then curing at a temperature of 40° C. or less, or after irradiating the liquid silicone composition with ultraviolet rays. , 100° C. or less, and curing within 30 minutes.

UV sources useful for curing the UV addition curable liquid silicone rubber adhesives of the present invention include conventional mercury vapor lamps designed to emit UV energy in various UV wavelength bands, metal halide lamps, Light emitting diode (LED) devices may be mentioned. For example, a useful ultraviolet wavelength range is 220-400 nm, more preferably 320-375 nm. In addition, the ultraviolet irradiation dose useful for curing is not particularly limited as long as the irradiation dose is sufficient for curing, but it is preferably 1,000 to 10,000 mJ/cm ² , more preferably 1,500 to 7,500 mJ. / ^cm2 .

Although there is no particular limitation on the time from irradiation of ultraviolet rays to bonding, it is preferable to perform the bonding until the ultraviolet addition-curable liquid silicone rubber adhesive thickens and gels.

The bonding method of the present invention can be suitably used in an image display device, and is particularly preferable as a bonding method between a polarizing plate, a touch panel, or a display panel and a glass panel (cover glass, etc.).

EXAMPLES The present invention will be specifically described below using Examples and Comparative Examples, but the present invention is not limited to these.

（式中、各シロキサン単位の配列は不定である。） [Synthesis Example 1]
100 g of a dimethylvinylsiloxy group-blocked dimethylpolysiloxane at both molecular chain ends having a viscosity at 25° C. of 5,000 mPa s, and a dimethylpolysiloxane having a viscosity of 20 mPa s and both molecular chain ends blocked with dimethylhydrogensiloxy groups, and the following formula: 0.84 g of the represented compound and 0.33 g of a 0.5% by mass solution of (methylcyclopentadienyl)trimethylplatinum complex [dimethylvinylsiloxy group-blocked dimethylpolysiloxane (viscosity 600 mPa s) at both ends of the molecular chain], 0.11 g of dimethylbis(1,1-dimethyl-2-propynyloxy)silane was mixed to prepare UV addition-curable liquid silicone rubber adhesive 1.

(In the formula, the arrangement of each siloxane unit is undefined.)

[Example 1, Comparative Example 1]
As shown in FIG. 1, the ultraviolet addition-curable liquid silicone rubber adhesive obtained in Synthesis Example 1 was applied to the first substrate 1, and an LED lamp with a wavelength of 365 nm was used to set the ultraviolet illuminance on the material surface to 100 mW/cm ² and An adhesive layer 3 was formed by irradiating ultraviolet rays under the condition of an integrated light amount of 3,000 mJ/cm ² . After irradiation with ultraviolet rays, the second substrate 2 was bonded together so that the bonding area was 25 mm×20 mm and the thickness of the bonding layer 3 was 230 μm, and left at rest at 23° C. for 24 hours. The first substrate 1 and the second substrate 2 bonded in a cross form are subjected to a load perpendicular to the bonding surface, and the plane tensile adhesive strength and cohesive failure rate (cohesive failure area occupying the entire adhesive area ratio) was measured according to JIS K 6249. Table 1 shows the results. The following substrates were used as the first substrate and the second substrate.
Glass: 25 mm × 80 mm, 5 mm thick glass plate Polarizing plate: NPF-CWQ1463VCU manufactured by Nitto Denko Co., Ltd. pasted on a support (above glass plate)

From the results in Table 1, in Example 1, curing of the ultraviolet addition-curable liquid silicone rubber adhesive progressed, and the flat tensile adhesive strength was good. On the other hand, in Comparative Example 1, in which a polarizing plate was used as the first substrate, curing inhibition of the ultraviolet addition-curable liquid silicone rubber adhesive occurred, and the substrates could not be bonded together.

From the above, it was confirmed that the adhesion method of the present invention can suppress curing inhibition due to the image display device member in UV addition curing.

It should be noted that the present invention is not limited to the above embodiments. The above-described embodiment is an example, and any device having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect is the present invention. included in the technical scope of

DESCRIPTION OF SYMBOLS 1... 1st board|substrate, 2... 2nd board|substrate, 3... Adhesion layer.

Claims (2)

A method for bonding a pair of opposed glass panels and an image display device member using an ultraviolet addition-curable liquid silicone rubber adhesive, comprising:
The ultraviolet addition-curable liquid silicone rubber adhesive contains a photoactive hydrosilylation reaction catalyst,
applying the ultraviolet addition-curable liquid silicone rubber adhesive to the glass panel to form an adhesive layer; irradiating the adhesive layer with ultraviolet rays to activate the photoactive hydrosilylation reaction catalyst; a lamination step of laminating the image display device member via the adhesive layer after irradiation ,
As the ultraviolet addition-curable liquid silicone rubber adhesive,
(A) an organopolysiloxane having a viscosity at 25° C. of 50 to 1,000,000 mPa·s and containing at least two alkenyl groups per molecule;
(B) A linear organohydrogenpolysiloxane having hydrogen atoms (Si—H groups) directly bonded to silicon atoms only at both ends of the molecular chain, or having at least two Si—H groups in one molecule Organohydrogenpolysiloxane which is a mixture of organohydrogenpolysiloxane and linear organohydrogenpolysiloxane having Si—H groups only at one end and/or only at both ends of the molecular chain: [ number of Si—H groups]/[number of alkenyl groups]=0.5 to 2.5,
as well as,
(C) one or more photoactivated hydrosilylation reaction catalysts selected from the following group
(1,5-cyclooctadienyl)diphenylplatinum complex, (1,5-cyclooctadienyl)dipropylplatinum complex, (2,5-norboradiene)dimethylplatinum complex, (2,5-norboradiene)diphenylplatinum complex, (Cyclopentadienyl) dimethyl platinum complex, (methylcyclopentadienyl) diethyl platinum complex, (trimethylsilylcyclopentadienyl) diphenyl platinum complex, (methylcycloocta-1,5-dienyl) diethyl platinum complex, (cyclopenta dienyl)trimethylplatinum complex, (cyclopentadienyl)ethyldimethylplatinum complex, (cyclopentadienyl)acetyldimethylplatinum complex, (methylcyclopentadienyl)trimethylplatinum complex, (methylcyclopentadienyl)trihexylplatinum complex , (trimethylsilylcyclopentadienyl)trimethylplatinum complex, (dimethylphenylsilylcyclopentadienyl)triphenylplatinum complex, (cyclopentadienyl)dimethyltrimethylsilylmethylplatinum complex, and bis(β-diketonato)platinum complex: (A ) and (B), an amount that is 0.1 to 1,000 ppm as the mass of platinum,
including
Using a viscosity of 10 to 200,000 mPa s at 25 ° C., and
A bonding method , wherein the (B) contains an organohydrogenpolysiloxane having an epoxy group, an acryloxy group, a methacryloxy group, an alkoxysilyl group, or a bisphenol skeleton. 2. The bonding method according to claim 1 , wherein the surface of the image display device member to be bonded to the glass panel is a polarizing plate, a touch panel, or a display panel.

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