JPH04178403A - Method for curing diethylentically unsaturated monomer - Google Patents

Abstract

PURPOSE:To obtain a cured resin, excellent in mass productivity, ultraviolet ray cutting properties, transparency, etc., and suitable as optical parts, etc., by blending a diethylenically unsaturated monomer with a specific photoinitiator and a specified ultraviolet ray absorber and then irradiating the resultant blend with active energy rays at a specific wavelength. CONSTITUTION:A photo-setting composition prepared by blending (A) 100 pts.wt. diethylenically unsaturated monomer [e.g. ethylene glycol di(meth)acrylate] with (B) 0.01-0.3 pt.wt. photoinitiator selected from compounds expressed by the formula (X is methyl, methoxy, etc.; n is 2 or 3; R is phenyl or methoxy), acetophenone-based photoinitiators and benzophenone-based photoinitiators and (C) 0.01-0.2 pt.wt. ultraviolet ray absorber selected from benzophenone-based ultraviolet ray absorbers and benzotriazole-based ultraviolet ray absorbers is irradiated with active energy rays at 40% ratio of energy at 370-450nm when the energy at 300-450nm is 100%.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for curing a diethylenically unsaturated monomer by irradiation with active energy rays such as ultraviolet rays. Suitable for manufacturing optical parts such as mirrors and optical discs.

[Conventional technology]

A method of manufacturing plastic lenses by irradiating a photocurable resin with ultraviolet rays from a mercury lamp as active energy rays has already been proposed (Japanese Unexamined Patent Application Publication No. 1983-1989).
194401, Japanese Patent Application Laid-Open No. 63-207632, etc.)
Although these methods have the advantage of being able to be cured in a short time by UV irradiation, the internal homogeneity of the cured resin and surface transfer accuracy are insufficient, and the transparency of the cured resin that is obtained is generally low. It had the disadvantage that its color and hue were inferior to those of polymers such as polymethyl methacrylate, polycarbonate, and diethylene glycol bisallyl carbonate. Therefore, optical parts such as lenses using cured resins obtained by conventional methods using ultraviolet rays have had many problems in practical use.

[Problem to be solved by the invention]

The present invention aims to improve the drawbacks of the conventional methods described above, and in particular, it is a curing method that is excellent in mass production and has excellent characteristics such as internal homogeneity, surface transfer accuracy, ultraviolet protection, transparency, and hue. The purpose is to provide a method suitable for manufacturing optical components that provide objects.

[Means to solve the problem]

According to the present invention, a photocurable composition comprising a diethylenically unsaturated monomer, a specific photopolymerization initiator, and a specific ultraviolet absorber in a specific ratio is coated with active energy rays having a specific wavelength. This goal was achieved by irradiating the area with light.

That is, in the method of the present invention, (A) based on 100 parts by weight of diethylenically unsaturated monomer, (B) the following formula (1) (wherein, X represents a methyl group, a methoxy group, or a chlorine atom). , n represents a number of 2 or 3, and R represents a phenyl group or a methoxy group. 0.01 to 0.3 parts by weight of the agent, and (C) a small amount selected from benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers (both 0.01 to 0.2 parts by weight of one type of ultraviolet absorber) When the energy in the wavelength range of 300 to 450 nm is taken as 100%, the photocurable composition contains 370 to 45 parts by weight.
The present invention provides a method for curing diethylenically unsaturated monomers, which comprises irradiating active energy rays in which the ratio of energy in the 0 ns wavelength range is 40% or more.

Examples of the diethylenically unsaturated monomer used in the present invention include P-bis[β-(meth)acryloyloxyethylthiofoxylylene, m-bis[β-(meth)acryloyloxyethylthiofoxylylene, −Bis[β
-(meth)acryloyloxyethyloxyethylthio]xylylene, m-bis[β-(meth)acryloyloxyethyloxyethylthio]xylylene, 4.4'-
Sulfur-containing di(meth)acrylates such as bis[β-(meth)acryloyloxyethylthio]diphenylsulfone, ethylene glycol di(meth)acrylate,
Alkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol(meth)acrylate, hexanediol di(meth)acrylate, 2.2-bis[4-( Bisphenol human skeleton-containing di(meth)acrylates such as meth)acryloyloxyphenyl]propane, its halogen-substituted derivatives, 2,2-bis(4-(2-methacryloyloxyethoxy)phenyl)propane, its halogen-substituted derivatives, m -Bis[(4-vinylphenyl)methylthio]xylylene, β,β'-bis[(4-vinylphenyl)methylthio]diethyl ether, and other styrenic compounds. Preferred diethylenically unsaturated monomers include: These are sulfur-containing di(meth)acrylates such as P-bis[β-(meth)acryloyloxyethylthiofylylene and m-bis[β-(meth)acryloyloxyethylthiofylylene.

In addition, "(meth)acryloyl" or "(meth)acryloyl" described in this specification
"(Meth)acrylate" is a general term for acryloyl and methacryloyl or acrylate and methacrylate.

The photopolymerization initiator used in the present invention has the above-mentioned formula (I)
The photoinitiator is selected from the following compounds, acetophenone photoinitiators, and benzophenone photoinitiators, and one type thereof may be used, or two or more types thereof may be used in combination.

Specific examples of photopolymerization initiators include the following.

2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4゜6-dolimethylbenzoyldiphenylphosphine oxide represented by the above-mentioned formula [I],
2.4.6-) Acylphosphine oxides and acyls such as methylbenzoyl phenylphosphinate methyl ester, 2,6-cyclobenzoyldiphenylphosphine oxide, 2,6-cymethoxybenzoyldiphenylphosphine oxide, etc. Phosphinate esters, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-diphenoxydichloroacetophenone, jetoxyacetophenone, 1-(4-isopropylphenyl) )-2-hydroxy-2-methylpropan-1-one and other acetophenone compounds, and benzophenone,
Methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 3,3'-dimethyl-
These include benzophenone compounds such as 4-methoxybenzophenone and diphenoxybenzophenone. Preferred photoinitiators are 2,4.6-)limethylbenzoyldiphenylphosphine oxide, trimethylbenzoylphenylphosphinic acid methyl ester, 1-hydroxycyclohexylphenylketone, benzophenone, and diphenoxybenzophenone.

The proportion of these photopolymerization initiators is 0.01 to 0.3 parts by weight, preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the diethylenically unsaturated monomer.

If the blending ratio of the photopolymerization initiator is too large, not only the internal homogeneity of the cured resin will be poor, but also the hue will deteriorate.

Furthermore, if the amount of photopolymerization initiator is too small, the composition cannot be sufficiently cured.

The ultraviolet absorber used in the present invention is selected from benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers, and these may be used alone or in combination of two or more.

Specific examples include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxinezophenone,
-Hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2.
2'-dihydroxy-4-methoxybenzophenone, 2
．． Benzophenone compounds such as 2'-dihydroxy-4,4'-dimethoxybenzophenone, 2- (2'-
Hydroxy-5-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-ditertiary-butylphenyl)benzotriazole, 2-(2
'-Hydroxy-3'-tacyl-5'-
Benzotriazole compounds such as (methylphenyl)benzotriazole.

The proportion of these ultraviolet absorbers is 0.01 to 0.2 parts by weight, based on 100 parts by weight of the diethylenically unsaturated monomer.
Preferably it is 0.03 to 0.1 part by weight. If the blending ratio of the ultraviolet absorber is too large, the cured product will not be sufficiently cured or the internal homogeneity of the obtained cured product will deteriorate. On the other hand, if the amount is too small, desired ultraviolet blocking properties cannot be obtained.

In the method of the present invention, when the energy in the wavelength range of 300 to 450 n- is taken as 100%, the active energy ray for curing the diethylenically unsaturated monomer is 370 to 450 nm.
b The proportion of ghee is 40% or more, preferably 50% or more,
More preferably, active energy rays occupying 60% or more are used. If the proportion of energy in the wavelength range of 370 to 450 cm is too small, the internal homogeneity of the cured product and the surface transfer accuracy will deteriorate. Active energy rays with such wavelength characteristics include a so-called metal halide lamp, Fusion System C, in which iodides and chlorides of iron, magnesium, gallium, etc. are sealed together with mercury in a discharge tube.
It can be obtained using an electrodeless lamp of type 2, type D, or the like.

It can also be obtained by passing active energy rays generated from a normal high-pressure mercury lamp or the like through a suitable filter and adjusting the wavelength modulation energy ratio to a desired ratio. As such a filter, for example, JIS B
UV34, UV36, L specified in 7113
-IA, L-38, etc. are used. Further, adjustment can also be made using a metal film, a dielectric multilayer film, or an interference filter using both.

In addition to the components (A), (B), and (C) described above, the photocurable composition used in the present invention may optionally contain a polymerization accelerator, polymerization regulator, antifogging agent, mold release agent, and other components. Additives can be added.

As a method of irradiating the photocurable composition used in the present invention with active energy rays, a mold for forming an optical component of a desired shape (for example, in the case of a lens, two glass molds constituting the desired lens shape) is used. A photocurable composition is injected into the cavity of a mold (such as a mold fixed via a gasket made of ethylene-vinyl acetate copolymer) in an inert gas atmosphere or in air, and then activated from both or one side. One method is to irradiate energy rays. Note that during irradiation, either a method of fixing the mold to the active energy rays or a method of irradiating while moving the mold on a conveyor or the like may be used.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Note that parts in the examples indicate parts by weight. In addition, various physical properties of the cured products described in the Examples were measured by the following test methods.

(1) Light transmittance: 50
The light transmittance at 0n■ was measured.

(2) Refractive index and Atsube number: Measured at 25° C. using an Atsube refractometer (manufactured by Atago Corporation).

(3) Optical distortion: The cured product obtained using the lens mold was measured with a Toshiba distortion tester (manufactured by Toshiba Glass Co., Ltd.), and those with no optical distortion were marked as ○, and those with optical distortion were marked as ×.

In addition, the amount of ultraviolet energy in the example is from the light source and the light source.
Pass through a filter and analyze with a monochromator,
The wavelength spectrum of the light intensity is measured using a photomultiplier, and using the obtained spectrum, 300 to 4
When the energy in the wavelength range of 50n- was taken as 100%, the ratio of the energy in the wavelength range of 370 to 450n- was determined. This ratio is hereinafter abbreviated as energy index.

Example 1 Sulfur-containing acrylic compound (1) CH represented by the following formula
l ”-CHg-5-C1bCH*-0-C-C=CHz
(1) (hereinafter abbreviated as monomer (1)) to 100 parts,
2.4.6-) Limethylbenzoyldiphenylphosphine oxide (hereinafter abbreviated as T?IDPO) 0.05
part, 2-hydroxy-4-octoxybenzophenone (
Add 0.05 part of [Biosoap 130" manufactured by Kyodo Yakuhin Co., Ltd.), add 0.2 part of t-butylperoxy-2-ethylhexanoate as a polymerization regulator, stir and mix uniformly, and then defoamer. The resulting composition was cast into a 6 m thick mold made of a mirror-finished glass plate and silicone rubber under an argon gas atmosphere.

Then, from a distance of 4001 cm above the glass surface of the mold, ultraviolet rays were irradiated for 8 minutes (4 minutes each from both sides of the glass) using a metal halide lamp (energy index = 53%) with an output of 80 W/ai. After demolding the obtained cured product, it was heated in an air oven at 100°C for 2 hours to obtain a colorless and transparent cured resin free of optical distortion.

This cured resin was cut and polished to the dimensions of a measurement sample to measure its physical properties, and the results of measuring its physical properties were as shown in Table 1.

In addition, the defoamed composition was similarly cast into a lens mold for a minus lens with a diameter of 80 cm and a center thickness of 1.5 cm, which was composed of a glass mold and a gasket made of ethylene-vinyl acetate copolymer, and was cured. . After demolding, it was heated in the same manner to obtain a colorless and transparent lens with no optical distortion.

Example 2 In place of 100 parts of the monomer (1) used in Example 1, a sulfur-containing acrylic compound (2) represented by the following formula (2) was used.
CH.

'-CHz-S-C1 (zcHz-0-C-C=CHz
(2) (hereinafter abbreviated as monomer (2)) was used in the same manner as in Example 1 except that 100 parts of monomer (2) was used, to obtain a colorless and transparent cured product with no optical distortion. It was processed in the same manner as in Example 1 and its physical properties were measured. The results were as shown in Table-1.

Further, in the same manner as in Example 1, a colorless and transparent lens without optical distortion was obtained by curing in a lens mold.

Example 3 A colorless and transparent cured product without optical distortion was obtained in the same manner as in Example 1 except that 0.1 part of benzophenone was used in place of 0.5 parts of TMDPOO used in Example 1. It was processed in the same manner as in Example 1 and its physical properties were measured. The results were as shown in Table-1.

Further, in the same manner as in Example 1, a colorless and transparent lens without optical distortion was obtained by curing in a lens mold.

Example 4 05 parts of TMDPOO used in Example 1 was added to 1-hydroxycyclohexylphenyl ketone "Irgacure 184".
A colorless and transparent cured product with no optical distortion was obtained in the same manner as in Example 1 except that 0.05 part of Ciba Geigy Co., Ltd. was used. It was processed in the same manner as in Example 1 and its physical properties were measured. The results are in the table-
It was as shown in 1.

Further, in the same manner as in Example 1, a colorless and transparent lens without optical distortion was obtained by curing in a lens mold.

Example 5 0.05 part of 2-hydroxy-4-octoxybenzophenone used in Example 1 was mixed with 2-(2'-hydroxy-5'
Example 1 except that 0.05 part of -methylphenyl)benzotriazole ("Biosorb 520" manufactured by Kyodo Yakuhin Co., Ltd.) was used and the ultraviolet irradiation time was changed from 8 minutes to 10 minutes (5 minutes on each side of the glass). In the same manner, a colorless and transparent cured product with no optical distortion was obtained. It was processed in the same manner as in Example 1 and its physical properties were measured. The results were as shown in Table-1.

Further, in the same manner as in Example 1, a colorless and transparent lens without optical distortion was obtained by curing in a lens mold.

Example 6 05 parts of TMDPOO used in Example 1 was added to 0.05 part of 1-hydroxycyclohexylphenyl ketone, and
Example except that the ultraviolet light source was changed from an 80 W/cm metal halide lamp to an 80 W/cm high-pressure mercury lamp and irradiated through an interference filter made of quartz glass with a metal film deposited (energy index = 62%). 1
In the same manner as above, a colorless and transparent cured product without optical distortion was obtained.

It was processed in the same manner as in Example 1 and its physical properties were measured. The results are in Table-1
It was as shown in .

Further, in the same manner as in Example 1, a colorless and transparent lens without optical distortion was obtained by curing in a lens mold.

Comparative Example 1 A cured product was obtained in the same manner as in Example 1 except that 0.05 parts of TMDPOO used in Example 1 was replaced with 0.05 parts of diethyloxanthone. The obtained cured product did not become colorless and transparent, but had a yellow color. It was processed in the same manner as in Example 1 and its physical properties were measured. The results were as shown in Table-1.

Further, when it was cured in a lens mold in the same manner as in Example 1, the obtained lens was yellow in color and had some optical distortion.

Comparative Example 2 A cured product was obtained in the same manner as in Example 1 except that the amount of TMDPOO in Example 1 was changed from 0.05 part to 0.5 part.

The obtained cured product did not become colorless and transparent but had a yellow color. It was processed in the same manner as in Example 1 and its physical properties were measured. The results are in the table-
It was as shown in 1.

Further, when it was cured in a lens mold in the same manner as in Example 1, the obtained lens was yellow and had optical distortion.

Comparative Example 3 The amount of TMDPOO in Example 1 was changed from 0.05 part to 0.00 part.
The same procedure as in Example 1 was carried out except that 5 parts were used. However, it was not sufficiently cured, so the UV irradiation time was increased to 20 minutes (10 minutes on each side of the glass), but a cured product that could be removed from the mold was not obtained.

Further, as in Example 1, the cured product was cured in a lens mold, but the cured product was not able to be removed from the mold.

Comparative Example 4 80W/C used as an ultraviolet light source in Example 3
A colorless and transparent cured product was obtained in the same manner as in Example 3, except that the metal halide lamp in I was replaced with an 80 W/CI high-pressure mercury lamp (energy index = 29%). It was processed in the same manner as in Example 1 and its physical properties were measured. The results were as shown in Table-1.

It was also cured in a lens mold in the same way. The obtained lens was colorless and transparent, but peeling from the glass mold was observed and there was some optical distortion.

Comparative Example 5 80W/C used as an ultraviolet light source in Example 4
A colorless and transparent cured product was obtained in the same manner as in Example 4, except that the metal halide lamp in I was replaced with an 80 W/cIII high-pressure mercury lamp (energy index = 29%).

It was processed in the same manner as in Example 1 and its physical properties were measured. The results are in Table-1
It was as shown in .

It was also cured in a lens mold in the same way. The obtained lens was colorless and transparent, but it peeled off from the glass mold and had some optical distortion.

Claims (1)

[Claims] (1) (A) For 100 parts by weight of diethylenically unsaturated monomer, (B) The following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, X is a methyl group , represents a methoxy group or a chlorine atom, n represents a number of 2 or 3, and R represents a phenyl group or a methoxy group), an acetophenone-based photoinitiator, and a benzophenone-based photoinitiator. (C) at least one UV absorber selected from benzophenone UV absorbers and benzotriazole UV absorbers; When the energy in the wavelength range of 300 to 450 nm is taken as 100%, the photocurable composition containing 01 to 0.2 parts by weight of 370 to 45
1. A method for curing a diethylenically unsaturated monomer, comprising irradiating active energy rays in which the ratio of energy in the wavelength range of 0 nm is 40% or more.