JP5550818B2 - Adhesive for optical components - Google Patents

Description

The present invention relates to an adhesive composed of a polyene-polythiol-based resin composition, an adhesive bonded with the adhesive, and an optical member. Here, “poly” indicates polyfunctionality of bifunctionality or higher.

In recent years, resin compositions that are cured by irradiation with actinic rays such as ultraviolet rays have been used in various fields as adhesives, coating agents, and the like. As one of such photocurable resin compositions, resin compositions containing polyene and polythiol as components are known (Patent Documents 1 to 10). Patent Document 10 is different from the present invention because an isocyanuric ring derivative is not used as a polythiol and an isocyanuric ring derivative is used as a polyene.

Japanese Patent Laid-Open No. 03-243626 Japanese Patent Application Laid-Open No. 07-082376 JP 07-003025 A Japanese Patent Application Laid-Open No. 09-111189 Japanese Patent Laid-Open No. 10-330450 JP 2000-102933 A JP 2001-194510 A JP 2002-182002 A JP 2003-238904 A JP 2003-277505 A

The resin composition containing polyene and polythiol as components has excellent transparency in the visible light region (400 to 800 nm), adhesiveness, and curability of the surface under air (hereinafter referred to as surface curability). As an adhesive for glass and transparent plastics, it is used in various fields such as optical parts and electronic parts.

However, in recent years, there is a background that the wavelength of an optical pickup light source such as a DVD drive is shortened to 300 to 415 nm. For this reason, the adhesive used for bonding optical members such as DVD drives has a new characteristic in addition to visible light transparency. Even when irradiated with light in the short wavelength region of 300 to 415 nm, the adhesive itself emits fluorescence. Therefore, there is a demand for a low-fluorescent adhesive that has a small amount of light and does not impair transparency in the visible light range.

An object of the present invention is to provide an adhesive comprising a low-fluorescence polyene-polythiol resin composition containing polyene and polythiol as main components, an adhesive bonded with the adhesive, and an optical component.

The solution to the above problem is achieved by adopting the following.

That is, the present invention comprises (1) a polyene containing a 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, (2) a polythiol, and (3) a photoradical polymerization initiator, and (2) the polythiol is It is an isocyanuric ring derivative represented by the general formula [1] or [2], and (3) the amount of the radical photopolymerization initiator is 0.01% by mass or more and 0.10% with respect to the total amount of polyene and polythiol. It is an adhesive for optical parts that is less than mass%,
Here, the general formulas [1] and [2] are




And R in these formulas represents a group containing a -SH group.
(1) The polyene is a polyene containing diallyl maleate and a 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, and (2) the polythiol is tris-2-hydroxyethyl-isocyanurate tris-β-mercapto It is a polythiol containing propionate, (1) the adhesive for optical components having a mass ratio of polyene to (2) polythiol in the range of 49: 1 to 1:49, and (3) initiation of radical photopolymerization. The adhesive for optical parts, wherein the agent is an alkylphenyl ketone derivative having a group represented by the following general formula [3],
Here, the general formula [3] is


X in the formula is any one selected from the group consisting of hydrogen, an alkyl group, an alkyl ether group, an alkylthioether group, and an alkylamino group, Y and Z are hydrogen or a methyl group, and R ₁ Is an alkyl group, a hydroxyalkyl group, an alkylaminoalkyl group, an alkyl ether group, an alkylphenyl group, a phenyl group, an oxime group, an acylphosphine group or a derivative thereof.
(3) The optical radical polymerization initiator is an adhesive for optical parts, characterized in that it is benzoin or a benzoin derivative represented by the following general formula [4]:
Here, the general formula [4] is


R ₂ in the formula is an alkyl group having 1 to 8 carbon atoms.
(3) The radical photopolymerization initiator is an adhesive for optical components that is one or more members selected from the group consisting of benzoin ethyl ether and benzoin propyl ether, and the adhesive for optical components has a wavelength of 200 to 450 nm, An adhesive for optical parts, characterized by being irradiated with light having an irradiation intensity of 0.1 to 10,000 mW / cm ² and an integrated irradiation amount of 10 to 100,000 mJ / cm ² and having a thickness of 0.0001 to 1 mm. It is a bonding method, and is an optical component bonded body bonded using the adhesive for optical components.

According to the present invention, by using an adhesive composed of a polyene-polythiol resin composition containing polyene and polythiol as main components, the adhesive itself even when irradiated with light having a short wavelength of 300 to 415 nm. Therefore, it is possible to provide an adhesive body and an optical component that do not impair the transparency in the visible light region.

Hereinafter, the present invention will be described in detail.

The polyene used in the present invention is an alkene having two or more carbon-carbon unsaturated bonds per molecule. Specific examples of the polyene used in the present invention include divinylbenzene, divinyltoluene and the like. Vinyl compounds, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, (meth) acrylate such as dipentaerythritol hexa (meth) acrylate, diallyl phthalate, di Rirumareeto, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, allyl compounds such as tetraallyloxyethane, allyl ether compound of polyoxypropylene diallyl ether, and the like.

The polythiol used in the present invention is a substance having an average molecular weight of 50 to 15000 having two or more thiol groups per molecule, and particularly preferred polythiols include mercapto group-substituted alkyl compounds such as dimercaptobutane and trimercaptohexane. And mercapto group-substituted allyl compounds such as dimercaptobenzene, polyhydric alcohol esters such as thioglycolic acid and thiopropionic acid, and reaction products of hydrogen sulfide with alkylene oxide adducts of polyhydric alcohols.

Specific examples of the polythiol used in the present invention include trimethylolpropane-tris- (β-thiopropinate), tris-2-hydroxyethyl-isocyanurate tris-β-mercaptopropionate, pentaerythritol. Examples include tetrakis (β-thiopropionate), 1,8-dimercapto-3,6-dioxaoctane, 1,8-dimercapto-3,6-disulfide octane, and triazine thiol.

Furthermore, it is preferable that the polythiol in the present invention is an isocyanuric ring derivative represented by the following general formula [1] or [2] because the adhesiveness, surface curability, and low fluorescence can be obtained with a good balance.

Here, the general formulas [1] and [2] are
And R in these formulas represents a group containing a -SH group.

Specific examples of the polythiol of the isocyanuric acid derivative include tris-2-hydroxyethyl-isocyanurate / tris-β-mercaptopropionate.

The polyene may be an isocyanuric ring derivative represented by the general formula [1] or [2]. In the case of polyene, R in the general formulas [1] and [2] represents a group containing a carbon-carbon double bond.

Specific examples of the (1) polyene of the isocyanuric acid derivative include triallyl isocyanurate, diallyl isocyanurate, isocyanuric acid ethylene oxide-modified tri (meth) acrylate, isocyanuric acid ethylene oxide-modified di (meth) acrylate and the like.

The mass ratio of polyene and polythiol used in the present invention is preferably in the range of 49: 1 to 1:49, particularly when the double bond in the polyene and the thiol group in the polythiol are in a chemical equivalent, good adhesion From the viewpoint of obtaining surface curability, it is most preferable. The chemical equivalent here means that (number of moles of polyene / number of double bonds of polyene molecule) and (number of moles of polythiol / number of SH groups of polythiol molecule) are equal.

The radical photopolymerization initiator in the present invention is not particularly limited as long as it is a compound that absorbs light and generates a radical capable of initiating polymerization, but is preferably a group represented by the following general formula [3]. And alkyl phenyl ketone derivatives having the same.

Here, the general formula [3] is
X in the formula is any one selected from the group consisting of hydrogen, an alkyl group, an alkyl ether group, an alkylthioether group, and an alkylamino group, Y and Z are hydrogen or a methyl group, and R ₁ Is an alkyl group, a hydroxyalkyl group, an alkylaminoalkyl group, an alkyl ether group, an alkylphenyl group, a phenyl group, an oxime group, an acylphosphine group or a derivative thereof.

Specific examples of photo radical polymerization initiators used in the present invention include benzoin derivatives such as benzyl, benzoin, benzoin benzoic acid, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, 4-phenylbenzophenone, etc. Benzophenone derivatives, alkylacetophenone derivatives such as 2,2-diethoxyacetophenone, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 1- (4-isopropylphenyl) 2-hydroxy-2-methylpropan-1-one, Α- such as-(4- (2-hydroxyethoxy) -phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. Hide Xyacetophenone derivatives, bisdiethylaminobenzophenone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) -1-Aminoalkylacetophenone derivatives such as 1-butanone-1, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6- And acylphosphine oxide derivatives such as dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide.

Furthermore, among the alkyl phenyl ketone derivatives, benzoin having low fluorescence and excellent reactivity or a benzoin derivative represented by the following general formula [4] is particularly preferable.

Here, the general formula [4] is
R ₂ in the formula is an alkyl group having 1 to 8 carbon atoms.

These radical photopolymerization initiators can be used singly or in combination of two or more, and can also be reacted in advance with polyene or polythiol, or polyene and polythiol. The blending amount of the photo radical polymerization initiator is preferably 0.01% by mass or more and 0.5% by mass or less, and particularly preferably 0.02% by mass or more and 0.3% by mass or less with respect to the total amount of polyene and polythiol. If it is 0.01 mass% or more, sufficient sclerosis | hardenability can be obtained, and if it is less than 0.5 mass%, visible light transparency will not be impaired by fluorescence emission.

In addition, the resin composition of the present invention has an adhesion improver such as a silane coupling agent, an antioxidant, a curing accelerator, a filler, a colorant, a thixotropy, if necessary, as long as the intended effect is not impaired. Additives such as an imparting agent, a plasticizer, a surfactant, a lubricant, and an antistatic agent can be added.

Examples of the transparent base material for optical parts using the adhesive comprising the resin composition of the present invention include glass materials such as quartz, quartz glass, borosilicate glass and soda glass, and halogenated substances such as potassium bromide and calcium fluoride. Single crystal ceramics such as mineral, sapphire, acrylic resin, polycarbonate resin, polystyrene resin, polyester resin, polyethylene resin, polypropylene resin, fluororesin, cellulose resin, styrene-butadiene copolymer, methyl methacrylate-styrene copolymer, silicone Resin materials such as resin and polycycloolefin resin can be exemplified.

The resin composition of the present invention can be cured by active energy rays such as light, and an optical member using an adhesive made of the resin composition can also be adhered by active energy rays such as light.

For curing or bonding with active energy rays such as light, halogen lamps, metal halide lamps, high power metal halide lamps (containing indium, etc.), low pressure mercury lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, xenon lamps, xenon excimer lamps An irradiation device using a xenon flash lamp or the like as a light source can be applied, and laser light, electron beam (EUV), or the like can also be applied.

The above apparatus can irradiate condensed light by a direct irradiation, a reflecting mirror, or the like, and collect and irradiate with a fiber or the like. A low wavelength cut filter, a heat ray cut filter, a cold mirror, or the like can also be used.

According to the present invention, a low-fluorescence polyene-polythiol resin composition containing polyene and polythiol as main components, a cured product thereof, an adhesive comprising the resin composition, and an optical member bonded using the adhesive Can be provided.

Optical component adhesive of the invention, wavelength 200 to 450 nm, irradiation intensity 0.1~10000mW / cm ^2, was irradiated with light of an integrated irradiation dose 10~100000mJ / cm ^2, a thickness of 0.0001~1mm conditions It is preferred to bond under.

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

Unless otherwise indicated in the following examples, “part” means “part by mass”.

Experimental Examples 1-7
13 parts of diallyl maleate as polyene, 17 parts of 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, and 70 parts of tris-2-hydroxyethyl-isocyanurate / tris-β-mercaptopropionate as polythiol Benzoin ethyl ether (Seiko Chemical Co., Ltd., Sequol BEE) as a radical photopolymerization initiator was added to the resulting composition in parts by mass shown in Table 1, and sufficiently stirred until each was dissolved. Manufactured.

Experimental Example 8
13 parts of diallyl maleate as polyene, 17 parts of 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, and 70 parts of tris-2-hydroxyethyl-isocyanurate / tris-β-mercaptopropionate as polythiol Benzoin propyl ether (Seiko Kagaku Co., Ltd., Sequol BPE) as a radical photopolymerization initiator was added to the resulting composition in parts by mass shown in Table 1, and each was sufficiently stirred until dissolved. Manufactured.

Experimental Example 9
30 parts of triallyl isocyanurate as a polyene, 70 parts of tris-2-hydroxyethyl-isocyanurate / tris-β-mercaptopropionate as a polythiol, and benzoin as a radical photopolymerization initiator Ethyl ether (Seiko Chemical Co., Ltd., Seikol BEE) was added at 0.1 part, and each was sufficiently stirred until dissolved to prepare a resin composition.

Experimental Example 10
A composition in which 30 parts of triallyl isocyanurate as a polyene, 70 parts of trimethylolpropane-tris- (β-thiopropinate) as a polythiol were mixed, and benzoin ethyl ether (Seiko) as a radical photopolymerization initiator were used. Chemical Co., Ltd., Seikol BEE) was added in parts by mass shown in Table 1, and each was sufficiently stirred until dissolved to prepare a resin composition.

Experimental Example 11
As a polyene, 13 parts of diallyl maleate, 17 parts of 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, and 70 parts of trimethylolpropane triacrylate were mixed with benzoin ethyl ether as a radical photopolymerization initiator. (Seiko Chemical Co., Ltd., Sequol BEE) was added at 0.3 part, and each was sufficiently stirred until dissolved to produce a resin composition.

Experimental Example 12
A polyene was mixed with 13 parts diallyl maleate, 17 parts isophorone diisocyanate 2-hydroxyethyl acrylate adduct, and polythiol with 70 parts trimethylolpropane-tris- (β-thiopropinate). As a radical photopolymerization initiator, benzoin ethyl ether (Seiko Chemical Co., Ltd., Sequol BEE) was added at 0.3 part, and each was sufficiently stirred until it was dissolved to prepare a resin composition.

The following performance evaluation was performed on the compositions obtained in the above Examples and Comparative Examples, and the results are shown in Table 1.

(1) Surface curing property The composition obtained on one side of one glass test piece (25 mm × 25 mm, thickness 2 mm) was applied with a thickness of 1 mm, and this was made by a condensing type fusion company in an air atmosphere. A sample for evaluating surface curability was obtained by using an electrodeless discharge lamp and irradiating light with an irradiation intensity of 100 mW / cm ² (365 nm) and an integrated irradiation amount of 6,000 mJ / cm ² . The evaluation method of surface curability was evaluated by finger touch according to the following criteria.
Judgment: ○ Without surface tack, △ With surface tack, × Uncured

(2) The composition obtained on one side of a quartz glass test piece (25 mm × 25 mm, thickness 2 mm) having a single light transmittance is applied, and another quartz glass test piece having the same shape is applied to the resin film thickness. Lamination was performed so as to be 10 μm. This is a composition obtained by irradiating light with an integrated irradiation amount of 6,000 mJ / cm ² through quartz glass using a condensing type electrodeless discharge lamp manufactured by Fusion, at an irradiation intensity of 100 mW / cm ² (365 nm). Was cured and adhered to obtain a sample for light transmittance evaluation. As for the light transmittance, a transmittance at a wavelength of 415 nm was measured using a spectrophotometer (manufactured by Shimadzu Corporation, UV-2550), and a value of 98% or more was evaluated as good.

(3) Fluorescence intensity Each composition is irradiated with light having an integrated irradiation amount of 6,000 mJ / cm ^{2 at} a irradiation intensity of 100 mW / cm ² (365 nm) using a condensing type electrodeless discharge lamp manufactured by Fusion. A cured product having a size of 25 mm × 25 mm and a thickness of 1 mm was prepared and used as a sample for evaluating fluorescence intensity. As for the fluorescence intensity, a fluorescence spectrophotometer (Hitachi 650-60 type) was used, and the fluorescence intensity at 415 nm at an excitation wavelength of 365 nm was measured.

Table 1 shows the following. According to the present invention, by using an isocyanuric ring derivative as a polythiol, there is an effect that the resin composition itself has little fluorescence even when irradiated with light having a short wavelength of 415 nm (Experimental Examples 1 to 9). By using an isocyanuric ring derivative as polythiol, there is also an effect that sufficient surface curability is obtained (Experimental Examples 1 to 9). When an isocyanuric ring derivative is not used as the polythiol and an isocyanuric ring derivative is used as the polyene, the resin composition itself has a lot of fluorescence when irradiated with light having a short wavelength of 415 nm (experimental). Example 10). When an isocyanuric ring derivative is not used as polyene or polythiol, the resin composition is not cured and surface curability cannot be obtained (Experimental Examples 11 to 12).

By using the adhesive comprising the polyene-polythiol resin composition of the present invention, even when light having a short wavelength of 300 to 415 nm is irradiated, the fluorescence of the adhesive itself is small and the transparency in the visible light range is impaired. No adhesives and optical components can be provided. Therefore, the present invention shows a remarkable effect in the application of optical parts and electronic parts that require low fluorescence.

Claims (7)

(1) a polyene containing a 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, (2) a polythiol, and (3) a photoradical polymerization initiator, and (2) the polythiol has the following general formula [1] or An isocyanuric ring derivative represented by [2], wherein (3) the optical radical polymerization initiator content is 0.01% by mass or more and 0.10% by mass or less based on the total amount of polyene and polythiol. Adhesive for parts.
Here, the general formulas [1] and [2] are


And R in these formulas represents a group containing a -SH group. (1) The polyene is a polyene containing diallyl maleate and a 2-hydroxyethyl acrylate adduct of isophorone diisocyanate, and (2) the polythiol is tris-2-hydroxyethyl-isocyanurate tris-β-mercapto The adhesive for optical components according to claim 1, wherein the adhesive is a polythiol containing propionate, and the mass ratio of (1) polyene to (2) polythiol is in the range of 49: 1 to 1:49. (3) The adhesive for optical components according to claim 1 or 2, wherein the radical photopolymerization initiator is an alkylphenyl ketone derivative having a group represented by the following general formula [3].
Here, the general formula [3] is


X in the formula is any one selected from the group of hydrogen, an alkyl group, an alkyl ether group, an alkylthioether group, and an alkylamino group, Y and Z are hydrogen or a methyl group, and R ₁ Is an alkyl group, a hydroxyalkyl group, an alkylaminoalkyl group, an alkyl ether group, an alkylphenyl group, a phenyl group, an oxime group, an acylphosphine group or a derivative thereof. (3) The optical component polymerization initiator according to any one of claims 1 to 3, wherein the radical photopolymerization initiator is benzoin or a benzoin derivative represented by the following general formula [4].
Here, the general formula [4] is


R ₂ in the formula is an alkyl group having 1 to 8 carbon atoms. (3) The optical component polymerization initiator according to any one of claims 1 to 4, wherein the radical photopolymerization initiator is at least one member selected from the group consisting of benzoin ethyl ether and benzoin propyl ether. The optical component adhesive according to any one of claims 1 to 5 is irradiated with light having a wavelength of 200 to 450 nm, an irradiation intensity of 0.1 to 10,000 mW / cm ² , and an integrated irradiation amount of 10 to 100,000 mJ / cm ² . A bonding method of an adhesive for optical parts, wherein the bonding is performed at 0001 to 1 mm. An optical component bonded body bonded using the optical component adhesive according to claim 1.