JPH09178908A - Light scattering body having adhesiveness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light scattering body giving a flexible cured film by preparing a photosetting adhesive compsn. based on a specified copolymer and dispersing particles different from the copolymer in refractive index in the compsn. SOLUTION: A photosetting adhesive compsn. based on a copolymer of ethylene-vinyl acetate with maleic acid and/or maleic anhydride is prepd. as a matrix and particles different from the copolymer in refractive index are dispersed in the compsn. The vinyl acetate content of the copolymer is preferably 10-50wt.%. The compsn. preferably contains 0.1-10 pts.wt. photosensitizer and 0.01-5 pts.wt. silane coupling agent based on 100 pts.wt. of the copolymer. The particles are preferably fine particles different from the copolymer in refractive index by 0.01-0.2 and having 0.5-200μm average particle diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light scatterer having a photo-curing adhesive property.

[0002]

2. Description of the Related Art Light diffusing materials that have been widely used hitherto have fine irregularities on the surface of glass or a transparent resin material, or uniformly disperse transparent fine particles having different refractive indexes in the glass or transparent resin material. The transmitted light is scattered by being dispersed. Further, a technique for imparting light scattering property by coating the surface of a transparent body with a cured film of a special silane compound mixture containing fine particles (Japanese Patent Laid-Open No. 58-58).
-42454) is also proposed.

[0003]

However, the above-mentioned scatterer having irregularities on the surface is liable to be soiled on the surface, and when a liquid such as water or oil is attached to the surface, the parallel light ray transmittance is increased and the haze is increased. The value decreases (the same phenomenon that the light scattering effect largely decreases when the frosted glass gets wet). Also,
As for the method, although the above-mentioned drawbacks are eliminated, since the material for dispersing the fine particles uses a transparent material having no hard self-adhesiveness such as glass, polycarbonate resin, polyester resin, acrylic resin or styrene resin, When using the body in combination with other members,
A temporary fixing process is required for the mounting, which complicates the process, and because it is a rigid body, the conformability of the shape to a member having some curved surface (such as a lamp cover) is poor,
There are problems that the use is extremely limited, a processing step is required, and the cost becomes high.

The present invention has been made in order to improve the above circumstances, and an object thereof is to provide a light-scattering body having a cured film having adhesiveness and being highly flexible.

[0005]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that ethylene-vinyl acetate and a copolymer composed of maleic acid and / or maleic anhydride as a main component. By using the photocurable adhesive composition as a matrix and adding and dispersing particles having a refractive index different from that of the copolymer, the composition has adhesiveness, and thus a light scattering material having adhesiveness is obtained. Since this light scatterer can be provided in a sheet form or a liquid form, the conventional problems described above can be solved, and since the light scatterer itself has adhesiveness, it can be used with various members. No adhesive is required for bonding, the cross-linked structure formed by curing significantly improves durability after bonding, and the cured film is highly flexible,
The present invention has been completed by finding that it is possible to easily bond not only flat surfaces but also various curved surfaces.

That is, the present invention provides (1) a photocurable adhesive composition comprising a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride as a main component, the above-mentioned copolymer and a refractive index. (2) A photo-curable adhesive composition comprising ethylene-vinyl acetate and maleic acid and / or maleic anhydride. Polymer 10
0.1 to 10 parts by weight of a photosensitizer and 0.01 to 5 parts by weight of a silane coupling agent are added to 0 parts by weight, and light having adhesiveness according to (1). Scatterer,
(3) The photocurable adhesive composition is an acryloxy group-containing compound, a methacryloxy group-containing compound and an allyl group-containing compound, relative to 100 parts by weight of a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride. 0.1 to 50 parts by weight of at least one of them is added, and the light scatterer having adhesiveness according to (1) or (2), (4) the added particles are ethylene-acetic acid It has a refractive index difference of 0.01 to 0.2 with a copolymer of vinyl and maleic acid and / or maleic anhydride, and has an average particle diameter of 0.5 to 200 μm. And 100 parts by weight of a copolymer of maleic acid and / or maleic anhydride.
A light-scattering body having an adhesive property as described in (1), (2) or (3), characterized by being added in an amount of 05 to 50 parts by weight.

The light-scattering body according to the present invention can be provided in the form of a sheet, can be attached to various members, and can be used as a scattering sheet by curing itself. Alternatively, it may be provided in a liquid form and applied on the surface of the transparent body and then cured. Further, since the light-scattering body itself has adhesiveness, an adhesive is not required for bonding to various members, and since it is a curable type, it has excellent durability including heat resistance.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. The light-scattering body of the present invention comprises a copolymer whose main matrix is ethylene-vinyl acetate and maleic acid and / or maleic anhydride as a main component. And a photocurable adhesive composition.

The copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride used in the present invention preferably has a vinyl acetate content of 10 to 50% by weight, more preferably 14 to 45% by weight. %. If the vinyl acetate content is lower than 10% by weight, the optical uniformity of the cured light scatterer will not be sufficient, while
When the content is more than 10% by weight, the optical uniformity is good, but the strength and durability after curing may be significantly reduced.

The content of maleic acid and maleic anhydride is 0.01 to 10% by weight, particularly 0.05 to 5% by weight.
It is preferred that If this content exceeds 10% by weight, workability may decrease.

A photosensitizer may be added to the above composition from the viewpoint of imparting photocurability. Examples of the photosensitizer (photopolymerization initiator) include radical photopolymerization type initiators such as hydrogen abstraction type initiators, intramolecular cleavage type initiators, α-hydroxyalkylphenone type initiators and α-aminoalkylphenone type initiators. An initiator is preferably used. Examples of the hydrogen abstraction type initiator include benzophenone, methyl orthobenzoylbenzoate, 4-benzoyl-4′-methylphenylsulfide, isopropylthioxanthone, diethylthioxanthone, ethyl-4- (diethylamino).
Benzene zoate etc. can be mentioned. Examples of the intramolecular cleavage type initiator include benzoin ether and benzyl dimethyl ketal. 2-hydroxy-2-methyl-1-phenylpropan-1-one as an α-hydroxyalkylphenone type initiator,
Examples thereof include 1-hydroxycyclohexyl phenyl ketone, alkylphenyl glyoxylate, and diethoxyacetophenone. As the α-hydroxyalkylphenone type initiator, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-
Examples thereof include 1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, acylphosphine oxide and the like. The above photosensitizers may be used alone or in combination of two or more, and the addition amount is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the above copolymer. .

In addition to the above-mentioned photosensitizer, an organic peroxide may be added to the composition of the present invention, if necessary, whereby both photocuring and thermosetting can be used together. As the organic peroxide to be added, any one can be used as long as it decomposes at 70 ° C. or higher to generate a radical, but one having a decomposition temperature with a half-life of 10 hours of 50 ° C. or higher is more preferable.

Examples of usable organic peroxides include 2,5-dimethylhexane-2,5-dihydroxyperoxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexane- 3, di-t-butyl peroxide, t-butyl cumyl peroxide, 2,5-
Dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide, α-α′-bis (t-butylperoxyisopropyl) benzene, n-butyl-
4,4′-bis (t-butylperoxy) palerate,
1,1-bis (t-butylperoxy) butane, 1,1
-Bis (t-butylperoxy) cyclohexane, 1,
1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, t-butylperoxyacetate, methyl ethyl ketone peroxide, 2-5 dimethylhexyl-2,
5-bisperoxybenzoate, butyl hydroperoxide, p-methane hydroperoxide, p-
Chlorbenzoyl peroxide, tert-butylperoxyisobutyrate, hydroxyheptyl peroxide, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide,
Cumyl peroxy octoate, succinic acid peroxide, acetyl peroxide, t-butyl peroxy (2-ethylhexanoate), m-toluoyl peroxide, benzoyl peroxide, t-
Butyl peroxyisobutyrate, 2,4-dichlorobenzoyl peroxide and the like can be mentioned.

As the organic peroxide, one of these is used.
These may be used alone or in admixture of two or more, and the addition amount thereof is 0 based on 100 parts by weight of the above copolymer.
-10 parts by weight, especially 0.1-10 parts by weight are sufficient.

Further, a silane coupling agent can be added as an adhesion promoter to the adhesive composition of the present invention. As this silane coupling agent, vinyltriethoxysilane, vinyltris (β-methoxyethoxy)
Silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane , Vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane,
There are γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane and the like, and one of these may be used alone or two or more of them may be used in combination. The addition amount of these silane coupling agents is usually 0.1% with respect to 100 parts by weight of the copolymer.
01 to 5 parts by weight.

Furthermore, an epoxy group-containing compound other than epoxysilane can be blended as an adhesion promoter. Such epoxy group-containing compounds include triglycidyl tris (2-hydroxyethylene) isocyanurate, neopentyl glycol diglycidyl ether,
1,6-hexanediol glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol (E
O) ₅ glycidyl ether, pt-butylphenyl glycidyl ether, adipic acid diglycidyl ester,
Examples thereof include o-phthalic acid glycidyl ester, glycidyl methacrylate, and butyl glycidyl ether. A similar effect can be obtained by alloying a polymer containing an epoxy group. These epoxy group-containing compounds can be used alone or in combination of two or more, and the addition amount is usually 0.1 to 20 parts by weight with respect to 100 parts by weight of the above copolymer. .

Further, in order to improve or adjust the physical properties (mechanical strength, adhesiveness, optical characteristics, heat resistance, wet heat resistance, weather resistance, crosslinking rate) and the like of the light-scattering body having adhesiveness of the present invention, In the present invention, an acryloxy group, methacryloxy group or allyl group-containing compound can be added to the above composition.

Most commonly used compounds for this purpose are acrylic acid or methacrylic acid derivatives such as their esters and amides. In this case, the ester residues include methyl, ethyl, dodecyl, stearyl,
In addition to alkyl groups having 1 to 24 carbon atoms, particularly 1 to 18 such as lauryl, cycloalkyl groups such as cyclohexyl group, tetrahydrofurfuryl group, aminoethyl group, 2-
Examples thereof include a halogenated substituent such as a hydroethyl group, a 3-hydroxypropyl group and a 3-chloro-2-hydroxypropyl group, a substituted alkyl group such as a hydroxyl group substituted and an amino group substituted. Also, acrylic acid or methacrylic acid and ethylene glycol, triethylene glycol, polyethylene glycol, glycerin, trimethylolpropane,
Esters with polyfunctional alcohols such as pentaerythritol are also used.

A typical example of the amide is diacetone acrylamide. Further, acryl or methacrylic acid ester such as trimethylolpropane, pentaerythritol and glycerin can be used as the polyfunctional crosslinking aid.

Examples of the allyl group-containing compound include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl maleate, and the like, and one or a mixture of two or more of them may be used. 0.1 to 100 parts by weight of the above copolymer
It is used by adding 50 parts by weight, preferably 0.1 to 30 parts by weight. If it is less than 0.1 part by weight, the improving effect of improving the mechanical strength may be lowered, and if it exceeds 50 parts by weight, workability and film-forming property during preparation of the adhesive may be lowered.

In addition, a hydrocarbon resin may be added to the composition of the present invention for the purpose of improving the workability of the light-scattering body and the workability such as bonding. In this case, the added hydrocarbon may be a natural resin type or a synthetic resin type. Rosin, rosin derivatives, and terpene resins are preferably used in the natural resin system. For rosin, gum-based resins, tall oil-based resins, and wood-based resins can be used. As the rosin derivative, rosin obtained by hydrogenation, heterogeneization, polymerization, esterification, and metal salification can be used.

As the terpene resin, a terpene resin such as α-pinene and β-pinene and a terpene phenol resin can be used. Also, other natural resins such as dammar, cobal, and shellac may be used. On the other hand, in the case of synthetic resins, petroleum resins, phenol resins, and xylene resins are preferably used. As the petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin, hydrogenated petroleum resin, pure monomer petroleum resin, and cumarone indene resin can be used. As the phenolic resin, an alkylphenol resin and a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

The amount of the above-mentioned hydrocarbon resin added is appropriately selected, but it is preferably 1 to 200 parts by weight with respect to 100 parts by weight of a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride. Preferably 5 to 1
50 parts by weight.

The light source to which the light-scattering material having the adhesive property of the present invention is applied includes various light sources such as sunlight, fluorescent lamps, and LEDs, among which, not only visible light but also harmful to the human body. Many light sources emit ultraviolet rays. Therefore, the light scatterer of the present invention may contain an ultraviolet absorber in the above composition for the purpose of blocking ultraviolet rays.

As the ultraviolet absorber, known ones can be used. As the benzophenone type ultraviolet absorber,
2,4-Digidroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2,
2'-dihydroxy-4-methoxybenzophenone,
2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone and the like can be mentioned.

Further, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-) are used as triazole type ultraviolet absorbers.
3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-
t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ',
5'-di-t-aminophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t- Butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'. −
Examples thereof include hydroxybenzoate.

These ultraviolet absorbers may be used alone or in admixture of two or more, and the addition amount is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the above copolymer.

In addition to the above additives, the composition of the present invention comprises
Antiaging agents, dyes, processing aids and the like can be added within a range that does not impair the effects of the present invention.

On the other hand, the particles to be added and dispersed in the photocurable adhesive composition (matrix) may be any particles having a refractive index different from that of the ethylene-vinyl acetate copolymer, In particular, it has a refractive index difference of 0.01 to 0.2, especially 0.05 to 0.2, with an average particle diameter of the above copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride. Fine particles of 0.5 to 200 μm, particularly 1 to 200 μm are preferable, and the addition amount thereof is 0.05 to 50 parts by weight, particularly 0.1 to 45 parts by weight based on 100 parts by weight of the ethylene-vinyl acetate copolymer. Parts by weight are preferred.

Examples of such fine particles include inorganic particles such as glass, quartz, silicon oxide, calcium carbonate, titanium oxide and zinc oxide, and organic particles such as silicone resin, acrylic resin, polyethylene, polystyrene and polyurethane.

To obtain the light-scattering body of the present invention, the constituents of the composition and the particles are uniformly mixed and kneaded by an extruder, a roll, etc., and then calendered, rolled, T-die extruded, and blown. It can be used by forming a film into a desired shape by a film forming method such as. At the time of film formation, embossing may be performed for the purpose of preventing blocking, facilitating pressure bonding with an adherend, and the like.

The sheet obtained as described above can be attached to a member by a conventional method. For example, lamination can be performed using a method such as a laminating method using a hot press, a direct laminating method using an extruder or a calender, or a thermocompression bonding method using a film laminator.

Further, each component can be uniformly dissolved in a solvent that does not affect the member, applied evenly on the surface of the member, temporarily press-bonded with another member, or can be photocured as it is. .

The curing conditions for the light-scattering material having adhesiveness of the present invention depend on the type of organic peroxide,
It is desirable that the temperature is 70 to 170 ° C., particularly 70 to 150 ° C. for 2 to 60 minutes, especially 5 to 30 minutes.

[0035]

Since the light-scattering body of the present invention has adhesiveness, it is necessary to separately use a pressure-sensitive adhesive or an adhesive when the conventional light-scattering body is formed by bonding various members together. The invention reduces the number of components called adhesive layers,
Further, since the light-scattering body itself has tackiness, there is no deviation due to slippage during alignment in the bonding process, and thus the labor can be greatly reduced. In addition, the light-scattering film formed has more flexibility than conventional ones, and thus can be combined with a complex shape other than a flat surface. Moreover, since it has a cross-linked structure by photo-curing, it has excellent durability such as heat resistance and moisture heat resistance.

[0036]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] 2.0 parts by weight of benzyl dimethyl ketal per 100 parts by weight of a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride (Model E-100H manufactured by Mitsubishi Chemical Co., Ltd.) Parts, 2.0 parts by weight of triallyl isocyanurate, 0.5 parts by weight of γ-glycidoxypropyltrimethoxysilane, surface-treated calcium carbonate (Chemipron A manufactured by Chemipro Kasei Co., Ltd.) 5
After adding parts by weight and sufficiently kneading at a temperature of 90 ° C. with a mixing roll, a film having a thickness of 0.4 mm was formed by a calendar method. Install this sheet on the halogen lamp,
The front luminance (luminance meter, manufactured by Minolta: S-100) was measured and found to be 2300 cd / m ² .

Further, this sheet was sandwiched between a glass plate and a polyester film, placed in a rubber bag, and left in an oven at 80 ° C. for 15 minutes while being deaerated with a vacuum pump to pre-press the glass plate and the polyester film. Then, this was irradiated with a 4 kw mercury lamp for 30 seconds and photocured to obtain a light scatterer. When this light scatterer was placed on a halogen lamp and the front luminance was measured, it was 2500 cd.
/ M ² . Further, when the state of the light-scattering body was observed after the adhesive-composited light-scattering body was left in an oven at 100 ° C. for 500 hours, no change in appearance was observed and the front luminance was hardly changed. .

[Example 2] The components used in Example 1 were uniformly dissolved in toluene, then uniformly coated on a polyester film with a roll coater and dried sufficiently.
A 30 μm light scattering coating was provided on the polyester film. The haze value and the total light transmittance of the light scatterer thus created were measured by a color computer (manufactured by Suga Test Instruments Co., Ltd .:
When measured by SM-5), the haze value is 52.7%,
The total light transmittance was 93.7%. Further, after the light-scattering body film was left in an oven at 130 ° C. for 30 minutes to cure the coating, the haze value and the total light transmittance were measured, and the haze value was 40.0%.
The total light transmittance was 95.3%.

Claims (4)

[Claims] 1. A particle having a refractive index different from that of the above copolymer is added to and dispersed in a photocurable adhesive composition containing a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride as a main component. A light-scattering body having adhesiveness, which is characterized in that 2. The photocurable adhesive composition contains 0.1 parts by weight of a photosensitizer per 100 parts by weight of a copolymer consisting of ethylene-vinyl acetate and maleic acid and / or maleic anhydride.
10. The light-scattering body having adhesiveness according to claim 1, wherein the light-scattering body is obtained by adding 10 to 10 parts by weight and 0.01 to 5 parts by weight of a silane coupling agent. 3. A photocurable adhesive composition comprising an acryloxy group-containing compound, a methacryloxy group-containing compound and an allyl group, relative to 100 parts by weight of a copolymer of ethylene-vinyl acetate and maleic acid and / or maleic anhydride. The light scatterer having adhesiveness according to claim 1 or 2, wherein at least one of the contained compounds is added in an amount of 0.1 to 50 parts by weight. 4. The particles to be added have a refractive index difference of 0.01 to 0.2 with a copolymer comprising ethylene-vinyl acetate and maleic acid and / or maleic anhydride, and have an average particle diameter of 0. 0.5-200 μm, and ethylene-
0.05 to 50 with respect to 100 parts by weight of a copolymer composed of vinyl acetate and maleic acid and / or maleic anhydride.
The light-scattering body having adhesiveness according to claim 1, wherein the light-scattering body is added in an amount of part by weight.