JP3183726B2 - Photoreactive composition and method for producing transparent laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoreactive composition and a method for producing a transparent laminate using the composition.

[0002]

2. Description of the Related Art Conventionally, a laminate in which a resin intermediate film layer such as polyvinyl butyral is provided between two transparent molded plates such as glass has a structure in which debris does not scatter even when the surface is broken by impact. From, it is called safety glass. Examples of uses of such safety glass include, for example,
A protective cover for a display material such as a CRT display or a liquid crystal display used for a windshield of an automobile, a control device in a factory, or the like is given.

As a method for producing the above-mentioned safety glass, for example, Japanese Patent Application Laid-Open No. 62-197339 discloses a method in which a photoreactive composition is inserted between two glass plates to carry out photopolymerization. In this method, a composite of an unreacted urethane resin composition and a photoreactive acrylic monomer composition is used as the photoreactive composition, and the object is to improve the adhesion to glass and the transparency.

However, when the above method is applied to, for example, the production of a laminate of a glass plate and a polycarbonate plate or an acrylic resin plate having excellent impact destruction properties, the two materials have different coefficients of thermal expansion. There is a problem that peeling occurs at the end of the laminate due to the difference in dimensional expansion and contraction caused by the above.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a photoreactive composition having excellent transparency and adhesion and an excellent transparency. It is another object of the present invention to provide a method of manufacturing a transparent laminate in which fragments are not scattered even when a surface material is broken and peeling does not occur due to a temperature change.

[0006]

Means for Solving the Problems The photoreactive composition of the first invention comprises (a) at least one selected from the group consisting of (meth) acrylates of alkyl alcohols having an alkyl group having 4 to 12 carbon atoms. A monomer main component 10 comprising 60 to 98% by weight of at least one kind of acrylate monomer and 2 to 40% by weight of (b) a vinyl monomer having an unsaturated double bond copolymerizable with the acrylate monomer.
0 parts by weight, (c) 2 to 30 parts by weight of a compound obtained by introducing a polymerizable unsaturated double bond into a molecule using rosin as a raw material, and (d) 0.001 to 5 parts by weight of a photopolymerization initiator. (However, those containing tackifiers
Excluded) . In the method for producing a transparent laminate according to the second invention, a transparent hard plastic plate and a transparent glass plate are opposed to each other, and the photoreactive composition is injected between the two, irradiated with light, cured, and laminated. It is characterized by being a body. As described above, the above object is achieved.

Hereinafter, the first invention will be described in detail.
The main monomer component used in the first invention is 60 to 98% by weight of at least one or more acrylate-based monomers (a) selected from alkyl (meth) acrylates,
It is composed of 40 to 2% by weight of a vinyl monomer (b) copolymerizable with the acrylate monomer.

As the acrylate monomer (a), an alkyl acrylate or alkyl methacrylate having an alkyl group of 4 to 12 carbon atoms is used. Examples of these acrylate monomers include (meth) acrylic N-butyl acid, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate and the like.

These acrylate monomers (a)
Can be used alone or in combination of two or more.

Examples of the vinyl monomer (b) copolymerizable with the acrylate monomer (a) include alkyl (meth) acrylates having 1 to 3 carbon atoms, isobornyl acrylate, and (meth) acrylic acid. , Acrylamide, (meth) acrylonitrile, N-substituted acrylamide, hydroxyethyl (meth) acrylate,
Examples include N-vinylpyrrolidone, acryloylmorpholine, maleic acid, itaconic acid, N-methylolacrylamide, epoxy group terminal (meth) acrylate, and the like. Particularly preferred among these vinyl monomers (b) are isobornyl acrylate, N-vinylpyrrolidone and carboxyethyl acrylate.

In addition to the above, as the vinyl monomer (b) forming a polymer having a low glass transition temperature, for example, terahydrofurfuryl acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, fluorine acrylate, silicon acrylate and the like are also used. It is possible.

The acrylate monomer (a) and the vinyl monomer (b) are composed of an acrylate monomer 60
It is blended with 40 to 2% by weight of the vinyl monomer with respect to 98% by weight. 40% by weight of vinyl monomer
Exceeding the range is not preferred because the adhesive properties of the acrylic pressure-sensitive adhesive decrease.

The compound (c) used in the first invention is a compound obtained by introducing a polymerizable unsaturated double bond into a molecule using rosin as a raw material, and is used for improving adhesion to a plastic plate. You. As a commercially available product of such a compound (c), for example, “K1000” manufactured by Shin-Nakamura Chemical Co., Ltd.
A "and Arakawa Chemical's" Beamset 101 "
Rosin may be used as a starting material and modified by adding a (meth) acrylic double bond.

In the photoreactive composition of the first invention, if the amount of the compound (c) is too small, the effect of improving the adhesion is not obtained. If the amount is too large, the composition becomes too hard to absorb a dimensional change due to thermal expansion. It is limited to 2 to 30 parts by weight based on 100 parts by weight of the monomer main component.

The photopolymerization initiator (d) used in the present invention includes, for example, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone [trade name "Darocur 2959" manufactured by Ciba Geigy Co., Ltd.] 1-hydroxycyclohexylphenyl ketone [Circa Geigy, trade name "Irgacure 184"], 2-hydroxy-2,2-dimethylacetophenone [Ciba Geigy, trade name "Darocur 1173"], methoxyacetophenone, 2,2 Acetophenone initiators such as dimethoxy-2-phenylacetophenone; benzoin ether initiators such as benzoin ethyl ether and benzoin isopropyl ether; ketal initiators such as benzyl dimethyl ketal;
Acylphosphinoxide, acylphosphonate and the like can be mentioned.

In the photoreactive composition of the first invention, when the content of the photopolymerization initiator (d) decreases, the photopolymerization initiator (d)
Is consumed in the initial polymerization due to light energy, so that unreacted monomers are apt to remain, and not only a monomer odor remains in the obtained polymer, but also a cohesive force is reduced. In addition, the photopolymerization initiator (d) When the content of is increased, the polymerization reaction rate is increased, but the residual odor accompanying the decomposition of the photopolymerization initiator (d) becomes intense, the variation in the molecular weight of the obtained polymer is increased, and the adhesive performance is reduced. The amount is limited to 0.001 to 5 parts by weight based on 100 parts by weight of the monomer main component.

The photoreactive composition of the first invention preferably contains a polymerizable crosslinking agent in order to impart heat resistance, cohesive strength at high temperatures, and the like. Examples of such a polymerizable crosslinking agent include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, other epoxy acrylates, polyester acrylates, urethane acrylates, etc. .

The content of the polymerizable crosslinking agent is preferably not more than 5 parts by weight based on 100 parts by weight of the main monomer component, since the control of the degree of crosslinking becomes difficult as the content increases. Due to the incorporation of the above polymerizable cross-linking agent, cross-linking occurs between the polymer molecules in the course of the photopolymerization reaction, and as a result, the heat resistance of the polymer is improved, the cohesive strength at high temperature is increased, and the high temperature is maintained. Power improves.

The photoreactive composition is crosslinked during the photopolymerization by the above polymerizable crosslinking agent. However, when the degree of crosslinking is low, bubbles are generated in the intermediate layer of the laminate due to the reaction shrinkage during the polymerization.
Conversely, if the degree of cross-linking increases and the temperature changes, the stress due to the difference in the coefficient of thermal expansion cannot be dispersed, and peeling occurs at the end of the laminate, so the degree of cross-linking of the photopolymer is expressed as a gel fraction. 30 to 80% by weight is preferred.

The photoreactive composition may optionally contain
In order to improve the adhesion to the glass interface, an epoxysilane-based coupling agent may be contained.

The photoreactive composition may further contain a thickener, if necessary, for example, in order to uniformly inject it between two transparent plates. Examples of such a thickener include acrylic rubber, epichlorohydrin rubber, isoprene rubber, butyl rubber and the like.

The viscosity of the photoreactive composition is preferably adjusted to 50 to 1000 cps by using the above-mentioned thickener. If it is 50 cps or less, it is difficult to prevent the injected composition from protruding, and if it is 1000 cps or more, air bubbles are apt to be mixed during the injection, which is not preferable.

Next, the second invention will be described. Examples of the photoreactive composition used in the second invention include the same photoreactive composition as in the first invention.

Examples of the transparent hard plastic plate used in the second invention include a polycarbonate plate, an acrylic resin plate and a vinyl chloride plate.

In the second invention, in order to produce a transparent laminate, for example, a transparent hard plastic plate and a transparent glass plate are opposed to each other, and the ends are sealed. Inject the reactive composition. Next, by irradiating light with a lamp to polymerize the photoreactive composition, the hard plastic plate and the glass plate are laminated to obtain a laminate.

The lamp used for the light irradiation preferably has a light emission distribution at a wavelength of 400 nm or less. A microwave excitation mercury lamp or the like is used.

Of these, the ultra-high pressure mercury lamp efficiently emits light in the active wavelength region of the initiator, and has short wavelength light or photoreactivity that reduces the viscoelastic properties of the resulting polymer by crosslinking. This is preferable because it does not emit much long-wavelength light that evaporates the composition by heating. In particular, as an ultra-high pressure mercury lamp, a so-called water-cooled type in which a circulating water jacket is provided on the lamp has a remarkable effect.

The light intensity of the lamp is a factor that affects the degree of polymerization of the polymer obtained from the photoreactive composition, and is appropriately selected depending on the performance of the target product. For example, when a conventional cleavage-type photopolymerization initiator having an acetophenone group is blended, the light intensity in a wavelength region (usually 365 to 420 nm) effective for photodecomposition of the polymerization initiator is 0.1 to 10
A range of mW / cm ² is preferred.

When the light intensity is less than 0.1 mW / cm ^2, the variation in the induction time due to the inhibition of the oxygen reaction becomes large, and it becomes difficult to obtain a polymer having a constant polymerization degree. At a light intensity exceeding 10 mW / cm ² , it is difficult to maintain the balance between the cohesive force and the stress dispersibility because the molecular weight is significantly reduced, and it is difficult to suppress the peeling of the edge while suppressing the generation of bubbles. It will be difficult.

[0030]

The polymer obtained by the polymerization of the photoreactive composition of the first invention has a plurality of functional groups having an affinity for each of a glass plate and a plastic plate, so that it is easily cured by light irradiation. In addition, it exhibits excellent adhesiveness to both substrates for which adhesion is difficult due to differences in surface polarity. In the method for producing a transparent laminate according to the second invention, the photoreactive composition is poured between a glass plate and a plastic plate and cured to form a laminate. Thereby, exfoliation does not occur at the end portion, and even if the surface material is broken, scattering of the fragments is prevented.

EXAMPLES Next, examples of the present invention and comparative examples will be described, but the present invention is not limited to these examples.

(Example 1) 850 parts by weight of 2-ethylhexyl acrylate, 50 parts of carboxyethyl acrylate
Parts by weight, 100 parts by weight of K1000A (manufactured by Shin-Nakamura Chemical Co., Ltd.), a photopolymerization initiator ("Darocur 11" manufactured by Ciba-Geigy)
73 ") 0.5 part by weight of hexanediol diacrylate and 0.5 part by weight of hexanediol diacrylate were placed in a separable flask, and stirred until uniform, and then dissolved oxygen was removed by purging with nitrogen gas to remove the photoreactive composition. Obtained. On the other hand, a transparent polycarbonate plate (thickness 2 mm, width 200 mm, length 3
00mm) and a transparent glass plate (2mm thick, 200m wide)
m, 300 mm in length) were opposed to each other, and the ends thereof were bonded together with an adhesive tape (1 mm in thickness, 5 mm in width) of a foam base material.

After injecting the above-described photoreactive composition between the two bonded transparent plates, the light intensity of the irradiated surface is 1 mW / cm ² [a light having a maximum sensitivity at 365 nm using a high-pressure mercury lamp as a radiation source. The height of the lamp is set so that the intensity is measured by an intensity meter UVR-1 (manufactured by Tokyo Optical Machine Co., Ltd.), and irradiation is performed for 10 minutes from the glass plate side to cure the photoreactive composition. This produced a transparent laminate. At this time, the residual monomer in the photopolymer was 0.3% by weight, and the gel fraction was 70% by weight.

A glass ball was dropped on the glass surface of the laminate to break the glass surface, but no glass fragments were scattered. When the laminate was heat-treated at 40 ° C. for one week, no bubbles were generated or peeled off at the ends.

Example 2 Example 1 was repeated except that 2 parts by weight of an epoxysilane coupling agent (3-glycidoxypropyltrimethoxysilane) was added to the photoreactive composition of Example 1. Similarly, after preparing a photoreactive composition, light was irradiated in the same manner as in Example 1 to produce a transparent laminate. A steel ball was dropped on the glass surface of the laminate to break the glass surface, but no scattering of glass pieces was observed. When the laminate was heat-treated at 40 ° C. for one week, no bubbles were generated or peeled off at the ends.

(Example 3) 850 parts by weight of 2-ethylhexyl acrylate, 25 parts by weight of N-vinylpyrrolidone,
Hydroxyethyl acrylate 25 parts by weight, beam set 101, 100 parts by weight, photopolymerization initiator (“Irgacure 184” manufactured by Ciba Geigy) 0.5 part by weight, hexanediol diacrylate 0.5 part by weight, and dodecyl mercaptan 0.3 part by weight Example 1 except that parts were blended.
After preparing the photoreactive composition in the same manner as in
Irradiation was carried out in the same manner as in the above to prepare a transparent laminate. A steel ball was dropped on the glass surface of the laminate to break the glass surface, but no scattering of glass pieces was observed. When the laminate was heat-treated at 40 ° C. for one week, no bubbles were generated or peeled off at the ends. Comparative Example 1 A photoreactive composition was prepared in the same manner as in Example 1 except that K1000A was not used, and then irradiated with light in the same manner as in Example 1 to produce a transparent laminate. . At this time, the gel fraction of the residual monomer in the photopolymer was 7
It was 0% by weight. A steel ball was dropped on the glass surface of the laminate to break the glass surface, but no scattering of glass pieces was observed. However, at 40 ° C.
After heat treatment for a week, peeling was observed between the polycarbonate plate and the photopolymer.

[0036]

The photoreactive composition of the first invention is excellent in transparency, easily cured by light irradiation, and firmly adheres to both glass plates and plastic plates. According to the method for producing a transparent laminate of the second invention, a transparent laminate in which a glass plate and a plastic plate are firmly bonded to each other is obtained by the photoreactive composition of the first invention. , And even if the surface material is damaged, the fragments are not scattered and the transparency is excellent.
It is very useful as a protective cover for displays such as RT.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08F 290/00-290/14 C08F 299/00-299/08 B32B 7/10 C08F 2/46-2/50 C08F 20 / 00-20/70 C08F 220/00-220/70 C09J 1/00-201/10

Claims (2)

(57) [Claims] (1) 60-98% by weight of at least one or more acrylate monomers selected from the group consisting of (meth) acrylates of alkyl alcohols having an alkyl group having 4 to 12 carbon atoms, and (b) ) 100 parts by weight of a monomer main component consisting of 2 to 40% by weight of a vinyl monomer having an unsaturated double bond copolymerizable with the acrylate monomer, and (c) a polymerizable unsaturated monomer in a molecule using rosin as a raw material. A photoreactive composition containing 2 to 30 parts by weight of a compound into which a heavy bond is introduced and (d) 0.001 to 5 parts by weight of a photopolymerization initiator (provided that tackiness is imparted).
Excluding those containing agents) . 2. A transparent hard plastic plate and a transparent glass plate are opposed to each other, and the photoreactive composition according to claim 1 is injected between the two, and irradiated with light to be cured to form a laminate. A method for producing a transparent laminate, comprising: