JPH06228274A - Heat-resistant optical resin - Google Patents

Abstract

PURPOSE:To obtain a heat-resistant optical resin, having a small strain in curing and excellent in transparency and heat resistance. CONSTITUTION:This heat-resistant optical resin is composed of an ultraviolet- curing resin consisting essentially of an alicyclic epoxy resin. A compound such as a diluent, a flexibilizer, a curing agent, a curing accelerator or a characteristic improver for the epoxy resin may be added as a secondary component. This resin is readily coated with hardly any shrinkage in curing and excellent in adhesion to substrates, transparency and heat resistance.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an optical waveguide, an optical lens,
The present invention relates to a heat-resistant optical resin having excellent light transmission and heat resistance, which can be used as a coating material, an optical adhesive and the like.

[0002]

2. Description of the Related Art As optical resins used in plastic optical fibers, optical waveguides, optical lenses, etc., thermoplastic resins such as polymethylmethacrylate, polystyrene, polycarbonate, etc. are used for glass such as quartz because of their economical efficiency and moldability. It is being used partly because it is better than others. However, the thermoplastic resin undergoes thermal deformation above the glass transition temperature and cannot withstand processes in environments exposed to high temperatures such as solder, vapor deposition, and sputtering. Recently, thermosetting resins such as bisphenol A epoxy resins have come to be used for optical waveguides, optical adhesives, etc. However, heat resistance is 200 ° C. or less and no one can withstand a high temperature process. In particular, many resins for optical use that have been reported so far have a thermal expansion coefficient of about 10 ⁻⁴ / ° C., and a resin film is formed on an inorganic substrate having a small thermal expansion coefficient such as silicon or quartz. In this case, even if the resin itself endured a high temperature process, swelling and cracks were generated due to the difference in the coefficient of thermal expansion, and the resin could not be used. Further, in the case of a thermosetting resin, since the shrinkage rate at the time of curing is large, the resin film is cured while including internal strain when forming a resin film on a substrate, which causes swelling or cracking in a high temperature process. was there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-resistant optical resin which has a small distortion during curing and is excellent in transparency and heat resistance.

[0004]

The present invention will be described in brief. The present invention relates to a heat-resistant optical resin, which is characterized by comprising an ultraviolet curable resin containing an aliphatic cyclic epoxy resin as a main component.

As a result of intensive studies conducted by the present inventors in order to achieve the above object, the ultraviolet curable resin containing an aliphatic cyclic epoxy resin as a main component has a low viscosity, and also has a small curing shrinkage ratio and a small thermal expansion coefficient. The inventors have found that they are extremely excellent in heat resistance and transparency, and have completed the present invention.

Aliphatic cyclic epoxy is used as the main component of the heat-resistant ultraviolet-curable resin in the present invention, and one having a high reactivity of the epoxy part is preferable. As such an example, 3,4-epoxycyclohexylmethyl-3,
4-epoxycyclohexanecarboxylate, 3,4
-Epoxycyclohexylethyl-3,4-epoxycyclohexanecarboxylate, vinylcyclohexene dioxide, allylcyclohexene dioxide, 3,4
-Epoxy-4-methylcyclohexyl-2-propylene oxide, 2- (3,4-epoxycyclohexyl-
5,5-spiro-3,4-epoxy) cyclohexane-
m-dioxane, bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxycyclohexyl) ether, bis (3,4-epoxycyclohexylmethyl) ether, Examples thereof include bis (3,4-epoxycyclohexyl) diethylsiloxane. These aliphatic cyclic epoxy compounds may be used alone or as a mixture.

As the auxiliary component of the heat-resistant ultraviolet-curable resin in the present invention, compounds such as an epoxy resin diluent, a flexibility-imparting agent, a curing agent, a curing accelerator, and a characteristic modifier can be added. Examples of such compounds include poly (oxyethylene), poly (oxypropylene), polypropylene oxide triol, polycaprolactone triol, polybutadiene diol, polybutadiene diglycidyl ether, poly-1,4- (2,3-epoxybutane)- Co-1,2- (3,4-epoxy) -Co-1,4
-Butadienediol, maleic anhydride modified polybutadiene, polybutadiene diacrylate, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, hydroxypropyl acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane Diacrylate, β-
Hydroxymethyl methacrylate, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, dibromo neopentyl glycol diglycidyl ether, phthalic acid diglycidyl ester, trimethylolpropane Polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol penta (oxyethylene) glycidyl ether,
p-tert-butylphenyl glycidyl ether, dibromophenyl glycidyl ether, lauryl alcohol pentadeca (oxyethylene) glycidyl ether, sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether, triglycidyl tris (2-
Hydroxyethyl) isocyanurate, resorcin diglycidyl ether, polytetramethylene glycol diglycidyl ether, adipic acid diglycidyl ester,
Hydroquinone diglycidyl ether, bisphenol S
Diglycidyl ether, terephthalic acid diglycidyl ester, glycidyl phthalimide, cetyl glycidyl ether, stearyl glycidyl ether, p-octylphenyl glycidyl ether, p-phenylphenyl glycidyl ether, glycidyl benzoate, glycidyl acetate, glycidyl butyrate, spiroglycol diglycidyl ether , Reduced maltose polyglycidyl ether and the like. The properties of the resin can be modified by adding these compounds individually or in a mixture to the main component.

The photoinitiator of the ultraviolet curable resin in the present invention may be any one as long as it reacts with an epoxy group by ultraviolet rays, and examples thereof include aromatic diazonium salts such as p-methoxybenzenediazonium hexafluorophosphate and triphenyl. Examples thereof include aromatic sulfonium salts such as sulfonium hexafluorophosphate, aromatic iodonium salts such as diphenyliodonium hexafluorophosphate, aromatic iodosyl salts, aromatic sulfoxonium salts, and metallocene compounds. Further, a silane coupling agent can be added to the ultraviolet curable resin of the present invention to improve the adhesiveness. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, and N-β- (aminoethyl) -γ-.
Aminopropyltriethoxysilane, N-bis [β-
(Aminoethyl)]-γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-
Methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β- (N-
Vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, methyltrimethoxysilane,
Methyltriethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium Chloride, γ-chloropropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane,
Methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltriethoxysilane, benzyltrimethylsilane, vinyltris (2-methoxyethoxy) silane, γ-methacryloxypropyltris (2-methoxyethoxy) silane, β- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, γ-
Examples thereof include ureidopropyltriethoxysilane, γ-isocyanurylpropyltriethoxysilane, and n-octyltriethoxysilane.

Since the heat-resistant UV-curable resin containing the above-mentioned main component, subcomponent, photoinitiator, silane coupling agent and the like, which is composed of an aliphatic cyclic epoxy, is a liquid at room temperature, it may be spin-coated or the like. It can be applied to substrates and wiring boards. If the viscosity of the resin is too high, it becomes difficult to apply the resin evenly. Therefore, the viscosity is preferably 10,000 poise or less. When the heat-resistant optical resin after curing is formed into a thick film, the viscosity of the resin is preferably high, and when formed into a thin film, the viscosity is preferably low. In addition, in the case of applying by spin coating, the heat-resistant optical resin after curing can be prepared by applying at low speed when forming a thick film and by applying at high speed when forming a thin film.

The applied heat-resistant ultraviolet curable resin is cured by being irradiated with ultraviolet rays from an ultraviolet light source such as a mercury lamp and can be used as a heat-resistant optical resin. Further, various patterns can be drawn by exposing the heat-resistant ultraviolet curable resin to ultraviolet rays using a mask. Since the unexposed portion is not cured, it can be removed by using a general-purpose organic solvent, for example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, alcohols such as methanol and ethanol.

Generally, curing contraction occurs when the ultraviolet curable resin is cured. When using a heat-resistant ultraviolet curable resin as a heat-resistant optical resin, when the curing shrinkage rate is large, distortion occurs between the substrate and the wiring portion, so the wiring portion is cut during curing, or peeled from the substrate, The board may break. A material having a large curing shrinkage may impair the reliability when used as a component. Further, when the heat-resistant optical resin is formed of a resin having a large curing shrinkage, the flatness thereof is deteriorated. Therefore, it is desirable that the curing shrinkage rate be 5% or less. In the case of a heat-resistant ultraviolet curable resin whose main component is an aliphatic cyclic epoxy resin, the curing shrinkage can be reduced to 5% or less.

When a resin is used as a heat-resistant optical resin, the coefficient of thermal expansion of the resin is generally higher than that of a substrate or wiring material. In many cases, thermal cycle in the environment causes distortion, causing swelling or peeling between the heat-resistant optical resin and the substrate or wiring portion. Therefore, it is desirable to make the coefficient of thermal expansion of the resin as small as possible. In the case of a heat-resistant ultraviolet curable resin whose main component is an aliphatic cyclic epoxy resin, the coefficient of thermal expansion can be reduced to 5 × 10 ⁻⁵ / ° C. or less.

When an optical resin is used in an electronic / optical mixed circuit or the like, solder heat resistance is naturally required. Further, in the case of multilayer wiring, in order to form a fine wiring pattern, when the wiring is formed on the optical resin by a sputtering method or the like, the temperature rise on the surface of the optical resin is unavoidable, so that the optical resin has heat resistance. Will be needed. A heat-resistant ultraviolet curable resin whose main component is an aliphatic cyclic epoxy resin has higher heat resistance than general epoxy resins.

[0014]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The parts in the examples are parts by weight.

Example 1 Aliphatic cyclic epoxy 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Union Carbide, trade name ERL-4)
221) Polypropylene oxide triol as an accessory component in 100 parts (manufactured by Union Carbide Co., trade name NIA
X Polyol LHT-240) 20 parts, sulfonium salt as a photoinitiator (Asahi Denka Kogyo KK, trade name Optomer SP
150) 5 parts, N-β-as a silane coupling agent
5 parts of (aminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., trade name A-1120) was mixed to obtain a heat resistant ultraviolet curable resin (Table 1).

When the viscosity of the heat-resistant ultraviolet curable resin before curing was examined, it was 5 poise. The cure shrinkage was determined by measuring the density before and after curing, and was 3.8%. The thermal expansion coefficient is a thermomechanical thermal expansion coefficient measuring device (TM70 manufactured by Vacuum Riko
The result was 4.5 × 10 ⁻⁵ / ° C. A heat resistant UV curable resin was applied on a silicon substrate by spin coating, cured by UV irradiation and cut into strips together with the substrate and immersed in a solder bath at 280 ° C for 30 seconds, resulting in no peeling or swelling. The solder heat resistance was good. The light transmittance was measured by measuring the heat resistance of the ultraviolet curable resin cured into a sheet having a thickness of 1 mm. A self-recording spectrophotometer U-3400 type (manufactured by Hitachi) was used for the measurement. FIG. 1 shows the spectrum of the cured (before treatment) sample. FIG. 2 shows a spectroscopic spectrum of the sample which was heat-treated at 300 ° C. for 1 hour. Although the sample was colorless and transparent, it became dark brown by heat treatment, and the transparency in the visible light region decreased, but the transparency in the long wavelength region was maintained. Light transmittance of 87 at wavelength of 1.3 μm
The percentage was 84% after heat treatment. Wavelength 1.55μ
In the case of m, the light transmittance was 84%, but it became 82% after the heat treatment. These characteristics are shown in Table 3. Further, the spectrum is shown as a graph showing the relationship between the wavelength (nm, horizontal axis) and the light transmittance (%, vertical axis).

Examples 2 to 29 Instead of ERL4221 as the main component in Example 1,
2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-m-dioxane (trade name ERL-423 manufactured by Union Carbide Co.)
4), bis (3,4-epoxycyclohexyl) adipate (manufactured by Union Carbide Co., trade name ERL-429)
9), or an aliphatic cyclic epoxy of vinylcyclohexene dioxide (manufactured by Union Carbide Co., trade name ERL-4206), and phenylglycidyl ether (manufactured by Nagase Chemical Industries Co., Ltd., trade name) instead of LHT-240 as an auxiliary component. Denacol EX-141), p-tert-butylphenyl glycidyl ether (manufactured by Nagase Chemical Industry Co., Ltd.,
Trade name Denacol EX-146), glycidyl phthalimide (Nagase Chemicals Co., Ltd., trade name Denacol EX-7
31), polybutadiene diglycidyl ether (manufactured by Nagase Chemical Industry Co., Ltd., trade name Denalex R-45 EPT),
Or poly-1,4- (2,3-epoxybutane) -co-
1,2- (3,4-epoxy) -co-1,4-butadienediol (manufactured by Nagase Chemicals Co., Ltd., trade name Denalex R-45EPI), instead of SP150 as a photoinitiator,
Sulfonium salt (Asahi Denka Kogyo KK, trade name Optomer S
P170) and using A-112 as the silane coupling agent.
Instead of 0, γ-aminopropyltriethoxysilane (manufactured by Nippon Unicar, trade name A-1100), γ-mercaptopropyltrimethoxysilane (manufactured by Nippon Unicar, trade name A-189), γ-methacryloxypropyl Trimethoxysilane (manufactured by Nippon Unicar, trade name A-1
74) or γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., trade name A-187), to obtain heat-resistant ultraviolet curable resins with the compounding compositions shown in Tables 1 and 2. The same evaluation as in Example 1 was performed for these. The evaluation results are shown in Tables 3 and 4. In addition, in Table 1 and Table 2, only the symbols and numbers are described as the product names.

Comparative Examples 1 to 3 Bisphenol A diglycidyl ether (manufactured by Yuka Shell Epoxy Co., trade name Epicoat 828) was used in place of the main component ERL-4221 of Example 1 and blended in the composition shown in Table 2 below. Thus, an ultraviolet curable resin was obtained. Using this ultraviolet curable resin, the same evaluations as in Examples 1 to 29 were performed. The evaluation results are shown in Table 4. Comparative Example 1 for solder heat resistance
In all of the samples, the film peeled from the substrate. In Comparative Example 3, heat treatment at 300 ° C. for 1 hour caused not only cracks in the sample but also deterioration, which made it impossible to measure the light transmittance. Spectroscopic spectra before and after heat treatment in Comparative Example 1 are shown in FIGS. 3 and 4.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

As described above, the heat-resistant optical resin of the present invention has the advantages that it is easy to apply, has a small shrinkage upon curing, and has excellent adhesion to a substrate, transparency and heat resistance. .

[Brief description of drawings]

FIG. 1 is a diagram showing a spectrum of a heat-resistant ultraviolet curable resin of Example 1.

FIG. 2 shows the heat-resistant ultraviolet curable resin of Example 1 at 300 ° C.
It is a figure which shows the spectrum of what heat-processed for a while.

FIG. 3 is a diagram showing a spectrum of an ultraviolet curable resin of Comparative Example 1.

FIG. 4 is a diagram showing a spectroscopic spectrum of the ultraviolet curable resin of Comparative Example 1 which was heat-treated at 300 ° C. for 1 hour.

Claims (1)

[Claims] 1. A heat resistant optical resin comprising an ultraviolet curable resin containing an aliphatic cyclic epoxy resin as a main component.