JPH0262546A - Improved optical photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain the photosensitive resin compsn. having good characteristics by incorporating a linear high-polymer material, multifunctional acrylate and/or multifunctional methacrylate having a prescribed value or below of the difference in refractive index from this material after polymn. curing, acrylate and/or methacrylate of a prescribed constitutional formula, and photopolymn. initiator into the above compsn. CONSTITUTION:Polymethyl methacrylate is used for the linear high-polymer material and a polymer of the polymethyl methacrylate and bifunctional methacrylate having a specific structure is used for the multifunctional acrylate and/or multifunctional methacrylate. The difference in the refractive index thereof from the polymethyl methacrylate is selected to <=0.15 at 0 to 80 deg.C. The acrylate and/or methacrylate expressed by the constitutional formula I (R1 is H or methyl group; R2 is <=10C alkyl group contg. a chain or ring, allyl group or allylalkyl group), for example, polymethyl methacrylate is added to the compsn. and 2-ethylanthraquinone or the like is added as the photopolymn. initiator thereto. The photosensitive resin which has the excellent optical characteristics in a wide temp. range and has durability is obtd. according to this constitution.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an optical photosensitive resin composition that provides an optical element with low light absorption and scattering loss over a wide temperature range and excellent durability. It is something.

[Conventional technology]

The technology of obtaining optical elements such as optical waveguides, holographic lenses, microprisms, and diffraction gratings by photolithography using photosensitive resin compositions has attracted attention from the viewpoint of microprocessability and mass-reproducibility unique to photolithography technology. There is.

For a method of forming an optical element (particularly an optical waveguide) using a photosensitive resin, see, for example, Optics Communications.
).

Volume 17 (1), page 129, 1976; Applied Physics Letters
sics Letters).

Vol. 24 (2), page 72, 1974; Oki Electric Research and Development Vol. 48 (3), page 73, 1981; Transactions of the Institute of Electronics and Communication Engineers J65-0 (11), page 860, 1982; Applied Optics (Appl.
ied 0ptics), Volume 17 (4).

646 Hage, 1978, etc.

[Problem that the invention seeks to solve]

The optical waveguide formed according to the above literature has an optical waveguide loss of 1
There was a problem in that it was impossible to create an element with a large waveguide length of 0 to 100 dB/m and a long waveguide length. Also, Applied Physics Letters (Appl 1edPhysics Letters)
Letters), Volume 24 (2), Page 72, 1974; Applied Oscitics (Appl.
ied Qptics), Volume 17 (4), 6
46 pages, 1978; Journal of the Institute of Electronics and Communication Engineers J65
-0 (11), p. 860, 1982; etc., it is difficult to control the composition of the photosensitive resin composition, it is necessary to distill off the monomer under reduced pressure during development, and production There was a problem with bad sex. Furthermore, conventional optical waveguides made of photosensitive resins have had the problem that optical waveguide loss changes as the temperature changes, and particularly in high humidity environments, optical waveguide loss increases significantly.

[Failure to solve the problem]

The present inventors conducted extensive research to solve the above-mentioned problems, and as a result, they arrived at the present invention.

That is, the present invention provides polyfunctional acrylates and/or This is an optical photosensitive resin composition characterized by comprising a polyfunctional methacrylate, (1) an acrylate and/or methacrylate having a structure represented by the following structural formula 1, and (2) a photopolymerization initiator.

(In the formula, % R1 is a hydrogen atom or a methyl group, R2
is a chain or ring-containing alkyl group having 10 or less carbon atoms,
It is an aryl group or an arylalkyl group. ) However, the refractive index difference between the polyfunctional acrylate and/or polyfunctional methacrylate and the linear polymer substance after polymerization and curing refers to 100 parts by weight of benzyl dimethyl ketal of the polyfunctional acrylate and/or polyfunctional methacrylate. A sample for measurement was prepared by adding and sufficiently photopolymerized and cured, and the measured value of the refractive index was measured at the wavelength of the sodium D line.

It refers to the feed value of the difference between the refractive index and the refractive index at the wavelength of the sl-IJum D line of a linear polymeric material.

As the linear polymer material used in the present invention, polycarf 1
? It is selected from polycondensation polymers such as Nate, homopolymers and copolymers of vinyl monomers, and those with excellent transparency. Examples of homopolymers include polymethyl methacrylate, polystyrene, polyvinyl chloride I, and poly-
Examples of copolymers include 4-methylpentene-1, Bori (1-methylcyclohexyl methacrylate), poly(4-methylcyclohexyl methacrylate), and poly(2-phenylethyl methacrylate). Methyl/methyl acrylate copolymer, acrylonitrile/styrene copolymer, methyl methacrylate/styrene copolymer, methyl methacrylate/cyclohexyl methacrylate copolymer, and the like. Among these linear polymeric substances, from the viewpoint of transparency, polymethyl methacrylate, polystyrene, 2-4-methylpentene-1, poly(1-methylcyclohexyl methacrylate), and poly(4-methyl methacrylate) are preferred. Methyl cyclohexyl), poly(2-phenylethyl methacrylate), methyl methacrylate/methyl acrylate copolymer Methyl methacrylate/methacrylate) kWll, cyclohexyl copolymer is used, more preferably poly(methyl methacrylate), methyl methacrylate/acrylic The acid methyl copolymer methyl methacrylate/'cyclohexyl methacrylate copolymer is used. In addition, the weight average molecular weight of these linear polymeric substances is preferably 5,000 or more in order to maintain the film thickness of the photosensitive resin composition, more preferably 20,000 to 1,000,000, and even more preferably 50,000 to 500,000. Use the one. Furthermore, the weight fraction of these linear polymeric substances in the composition is preferably 20% or more in order to be used as a solid substance, and 80% or less in order to obtain sufficient photosensitivity. is preferred.

Examples of the polyfunctional acrylate and/or polyfunctional methacrylate used in the present invention include ethylene glycol cyacrylate, ethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, and tetraethylene glycol dimethacrylate. Glycol dimethacrylate, nonaethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexane fold diacrylate, 1,6-hexane thiol dimethacrylate, propylene glycol dimethacrylate acrylate,
Propylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpronoglycol triacrylate, pentaerythritol triacrylate, compounds with the structure represented by the following structural formula 2, compounds with the structure represented by the following structural formula 3 compounds, etc.

Below margin 0=0
The refractive index difference is selected to be 0.015 or less. If an optical element is made using a composition with a refractive index difference of more than 0.015, the optical loss will be extremely large. Examples of these combinations include poly(methyl methacrylate) and bifunctional methacrylate of structural formula 2, poly(1-methylcyclohexyl methacrylate)! J ethylene glycol dimethacrylate, poly(4-methylcyclohexyl methacrylate) and neopentyl glycol diacrylate, poly(methacrylic acid-2)
-phenylethyl), bifunctional methacrylate of structural formula 3, etc. are preferred.

Examples of the acrylate and/or methacrylate having the structure represented by Structural Formula 1 used in the present invention include methyl methacrylate, ethyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, cyclohexyl methacrylate, and acrylate. 4-methylcyclohexyl acid, 1-methylcyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, 4-methylcyclohexyl methacrylate, 4-methacrylate
-1-butylcyclohexyl, phenyl methacrylate,
Examples include benzyl methacrylate.

Among these acrylates and/or methacrylates, cyclohexyl methacrylate, 4-methylcyclohexyl methacrylate, and 4-1-methacrylate are preferred.
Butylcyclohexyl, n-butyl acrylate, and methyl methacrylate are used, and from the viewpoint of ease of handling, cyclohexyl methacrylate, which has a high boiling point, is preferably used.
4-tert-butylcyclohexyl methacrylate is used.

Furthermore, the best results can be obtained when the refractive index difference between the acrylate and/or methacrylate polymer represented by Structural Formula 1 and the linear polymeric substance is selected to be 0.015 or less. .

The photopolymerization initiator used in the present invention is preferably a radical polymerization initiator, such as 2-ethylanthraquinone,
Benzoin methyl ether, benziin isopropyl ether, benzoin isobutyl ether, benzophenone, 4,4'-bis(dimethylamino)-benzophenone, be/zyl dimethyl ketal, 1-phenyl-1,2
-frononodione-2-o-(ethoxylzenyl)
Examples include oximes. Usually, these photopolymerization initiators are used in an amount of 0.0 based on the total weight of the photosensitive resin composition of the present invention.
It is preferable to use 5/100 to 5/100.

[Knowledge]

By using the optical photosensitive resin composition of the present invention, it is possible to easily produce an optical element with a small and constant optical waveguide loss in the temperature range of 0°C to 80°C and excellent moisture resistance with high productivity. can be manufactured.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to examples, but the present invention is not limited to the examples.

Example 1 58 parts of polymethyl methacrylate (manufactured by Asahi Kasei Corporation), 21 parts of bifunctional methacrylate having the structure represented by structural formula 2 (manufactured by Nippon Kayaku ■, trade name HX-220M), 21 parts of cyclohexyl methacrylate, and 2 parts of benzyl dimethyl ketal was dissolved in 135 parts of methyl ethyl ketone to form a homogeneous solution. After passing this through the mouth to remove dust, 100 μm
It was applied with a doctor blade onto a polyvinylidene fluoride film having a thickness of 90 μm and dried to obtain a transparent coating film having a thickness of 90 μm.

A linear optical waveguide with a width of 140 μm and a length of 400 μm was prepared by irradiating ultraviolet light through a photomask, developing with 1,1,1-trichloroethane, and rinsing with water.
I got a turn. When the optical transmission loss coefficient of this linear optical waveguide was measured using a He-Ne laser (output 2 mW) with a wavelength of 632.8r++n, it was found to be 1 dB at 0°C.
/m, 1dB at 20℃7271.14871 at 40℃2dB/m at 160℃, 80℃
11dB/ff! Met. In addition, when we conducted a durability test for 1000 hours at 60°C and 95% relative humidity in a constant temperature and humidity chamber for a sample of this linear optical waveguide, we found that it was 63.
The optical transmission loss coefficient at 2.8℃m is 4dB/m at 0℃
4dB/m at 120℃, 4dB/m at 40℃
m, sdB/m at 5 parts °C, and 14 dB/m at 801::.

When the refractive index of the polymerized cured product of polymethyl methacrylate and the compound of structural formula 2 was measured using an Atsube refractometer, they were 1.4940 and 1.4979 at 0°C, respectively.
．． 1.4920 and 1.4933.40℃ at 20℃
1.4901 at 1.4901 and 1.4887.1 at 80°C. ．． They were 4860 and 1.4794.

Example 2 Example October? Same as Example 1 except that methyl remethacrylate is replaced with poly(1-methylcyclohexyl methacrylate), the compound of structural formula 2 is replaced with triethylene glycol dimethacrylate, and cyclohexyl methacrylate is replaced with 2-methylcyclohexyl methacrylate. A linear waveguide with a width of 140 μm and a length of 400 μm was created by the following method. The optical transmission loss of this straight waveguide is the wavelength 632.8
When measured using a nm IIe-Ne laser (output 2 mW), it was 1 dB/m at 0°C, 201
: ldl:17m.

2 dB/'F's at 40'C 3 dB/m at 60'C.

It was 13 dB/m at 80°C. Also, regarding the sample of this linear optical waveguide, it was placed in a constant temperature and humidity chamber at 60'C195%
After conducting a relative humidity durability test for 1000 hours,
The optical transmission loss coefficient of 632.8 nm is 4d at 0°C.
B/m, 4 dB/m at 20°C, 6 dB/m at 40'C, 7 dB/m at 60°C, 80
'C was 16 dIl/m.

When the refractive index of the polymerized cured products of poly(1-methylcyclohexyl methacrylate) and triethylene glycol dimethacrylate was measured using an Atsube refractometer, they were 1.5156 and 1.5160.20 at 0°C, respectively.
1.5111 at °C and 1.5064 at 1-5125.40 °C and 1.4 at 1.4992.80 °C
971 and 1.4824.

Example 3 Example 1-4? A linear shape of @140 μm and a length of 400 mm was prepared in the same manner as in Example 1, except that methyl remethacrylate was replaced with poly(4-methylcyclohexyl methacrylate) and the compound of structural formula 2 was replaced with neopentyl glycol diacrylate. A waveguide was created. The optical transmission loss of this straight waveguide is determined by He-Ne with a wavelength of 632.8 nm.
When measured using a laser (output 2 mW),
1aB/m at 0℃, 1aB/m at 20℃
m, 1dB/ff at 40°C, 3d13/m at 1160°C, and 12aB/m at SO°C. Furthermore, when a durability test of this linear optical waveguide sample was conducted in a constant temperature and humidity chamber at 60°C and 95% relative humidity for 1000 hours, the optical transmission loss coefficient at 632.8°C was 4 dB/m at 0°C. , 4an/at 20℃
m.

5aB/m at 40℃, 7aB/m at 60℃
m.

It was 15aB/m at 80°C.

When the refractive indexes of the polymerized cured products of poly(4-methylcyclohexyl methacrylate) and neopentyl glycol diacrylate were measured using Atsube's refractive index, they were 1.5015 and 1.5009.20, respectively, at 0°C.
1.4975 at °C and 1.4976.1.4935 at 40 °C and 1.4943.1.4 at 80 °C
855 and 1.4877.

Example 4 The polymethyl methacrylate of Example 1 was replaced with sm (2-phenylethyl methacrylate), the compound of formula 2 was replaced with a bifunctional methacrylate of structural formula 3, and the cyclohexyl methacrylate was replaced with phenyl methacrylate. was made with a width of 140 μm and a length of 40 (h+
An o++ linear waveguide was created. When the optical transmission loss of this linear waveguide was measured using a He-Ne laser (output 2 mW) with a wavelength of 632.8 °Cm, it was 2aB/m at 0 °C, 2aB/m at 20 °C, 4
2dB/ly at 0℃! , 3aB at 60°C
/m was 12aB/m at 180°C. In addition, regarding the sample of this linear optical waveguide, it was
When a durability test was conducted at 5% relative humidity for 1000 hours, the optical transmission loss coefficient of 632 J nm was 5 at 0°C.
aB/m, 5aB/'m at 20℃, 6aB/m at 40℃, 8dB/7F+ at 60℃,
15dB/ff at 80℃! Met.

When the refractive index of the polymerized cured product of poly(2-phenylethyl methacrylate) and the compound of structural formula 3 was measured using an Atsube refractometer, it was 1.562 at 0°C.
9 and 1.5654.1.5592 and 1.5 at 20°C.
5556. 1.5554 and 1.5556 at 40°C
．． They were 1.5482 and 1.5454 at 80°C.

Comparative Example 1 58 parts of polymethyl methacrylate (manufactured by Mukasei Kogyo ■), 42 parts of bifunctional methacrylate having the structure represented by structural formula 2 (manufactured by Nippon Kayaku ■, trade name HX-220M), and 2 parts of benzyl dimethyl ketal. was dissolved in 135 parts of methyl ethyl ketone to form a homogeneous solution. After passing this through the mouth to remove dust, it was applied with a doctor blade onto a 100 μm thick film of atomized vinylidene, and dried to a thickness of 90 μm.
A transparent coating film with a thickness of . Irradiated with ultraviolet rays through a photomask, developed using 1.1.1-)lichloroethane, and rinsed with water to obtain a size of 140 μm in width and 4 in length.
A pattern of a linear optical waveguide with a length of 0.00 mm was obtained. When the optical transmission loss coefficient of this straight optical waveguide was measured using a He-Ne laser (output 2 mW) with a wavelength of 632.8 nm, it was 1 dB/m at 0°C, 1 aB/" at 20°C, and 1 aB/" at 40°C. 2aB/m, 60℃
5 dB/m at 580°C and 11 aB/m at 80°C. When a durability test of this linear optical waveguide sample was conducted for 1000 hours at 60°C and 95% relative humidity in a constant temperature and humidity chamber, the optical transmission loss coefficient at 632.8°Cm was 130 dB/yn at 20°C. Ivy.

Comparative Example 2 58 parts of polymethyl methacrylate (manufactured by Mukasei Kogyo ■), a bifunctional methacrylate having a structure represented by the following structural formula 4 (
42 parts of Nippon Kayaku ■, trade name MANDA) and 2 parts of benzyl dimethyl ketal to 135 parts of methyl ethyl ketone.
to make a homogeneous solution.

After passing through the mouth to remove dust, it was applied onto a 100 μm thick film of polyvinylidene buttride using a doctor blade and dried to obtain a transparent coating film with a thickness of 90 μm. Irradiate ultraviolet light through a photomask, 1,1.1-
The film was developed using dichloroethane and rinsed with water to obtain a linear optical waveguide having a width of 140 μm and a length of 400 μm. The optical transmission loss coefficient of this linear optical waveguide was measured using a He--Ne laser (output 2 mW) with a wavelength of 632.8° C.m, and was found to be 80 aB/m at 23° C.

The refractive indexes of the polymerized cured products of poly(methyl methacrylate) and the compound of structural formula 4 were measured using an Ashibe refractometer and were found to be 1A93 and 1°510, respectively, at 23°C.

(Structural formula 4 Asahi Kasei Koto Co., Ltd.

Claims (4)

[Claims] (1) A linear polymeric substance, (2) After polymerization and curing, the refractive index difference with the above linear polymer substance is 0.
A polyfunctional acrylate and/or a polyfunctional methacrylate of 0.015 or less in the temperature range of °C to 80 °C, (3) an acrylate and/or methacrylate having a structure represented by the following structural formula 1; (4) Optical photosensitive resin composition characterized by consisting of a photopolymerization initiator ▲ Numerical formula, chemical formula, table, etc. ▼ (Structural formula 1) (In the formula, R_1 is a hydrogen atom or a methyl group, R_2 is a chain-like or ring-containing alkyl group, aryl group, or arylalkyl group having 10 or less carbon atoms.)