JP3091976B2 - Curable composition for optical parts - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photocurable composition which is cured by irradiation with active energy rays such as ultraviolet rays, and particularly relates to a lens, a prism,
The present invention relates to a photocurable composition for cast polymerization suitable for manufacturing optical components such as mirrors and optical disks.

(Prior Art) A method of manufacturing a plastic lens by irradiating a photocurable resin with ultraviolet rays such as a mercury lamp as an active energy ray has already been proposed (JP-A-61-194401, JP-A-61-194401).
No. 63-207632). This method has the advantage that it can be cured in a short time by ultraviolet irradiation, but the cured resin has insufficient internal homogeneity and surface transfer accuracy, and in general, the transparency and hue of the obtained cured resin are polymethyl methacrylate. , Polycarbonate and diethylene glycol bisallyl carbonate. Therefore, conventional optical components such as lenses using this type of ultraviolet curable resin have many problems in practical use.

(Problems to be Solved by the Invention) The present invention is intended to improve the above-mentioned disadvantages of the conventional photopolymerizable composition for producing an optical component, and in particular, internal homogeneity, surface transfer accuracy, and transparency. Another object of the present invention is to provide a photocurable composition which gives a cured product having excellent properties such as color and hue, preferably a photocurable composition suitable for producing an optical component by cast polymerization.

(Means for Solving the Problems) According to the present invention, the object is achieved by a photocurable composition in which a photopolymerizable monomer contains a specific photopolymerization initiator and a specific organic peroxide in a specific ratio. Something that could be achieved.

That is, the curable composition of the present invention comprises: (A) 100 parts by weight of a photopolymerizable diethylenically unsaturated monomer (excluding an oligomer); (In the formula, 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.) 0.01-0.
A photocurable composition for optical parts comprising 3 parts by weight and (C) 0.02 to 0.5 part by weight of an organic peroxide having a 10-hour half-life temperature in the range of 50 to 95 ° C.

Examples of the photopolymerizable diethylenically unsaturated monomer used in the present invention include p-bis [β- (meth) acryloyloxyethylthio] xylylene and m-bis [β-
(Meth) acryloyloxyethylthio] xylylene,
p-bis [β- (meth) acryloyloxyethyloxyethylthio] xylylene, m-bis [β- (meth) acryloyloxyethyloxyethylthio] xylylene, 4,4′-bis [β- (meth) acryloyloxy Sulfur-containing di (meth) acrylates such as ethylthio] diphenylsulfone, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, Alkylene glycol di (meth) acrylates such as hexanediol di (meth) acrylate, 2,2-
Bis (4- (meth) acryloyloxyphenyl) propane, its halogen derivative, 2,2-bis [4- (2-methacryloyloxyethoxy) phenyl] propane, its halogen derivative, etc. ) Acrylates, m-bis [(4-vinylphenyl) methylthio] xylylene, β, β′-bis [(4-
Styrene-based compounds such as vinylphenyl) methylthio] diethyl ether. Particularly preferred diethylenically unsaturated monomers are sulfur-containing di (meta) such as p-bis [β- (meth) acryloyloxyethylthio] xylylene and m-bis [β- (meth) acryloyloxyethylthio] xylylene. ) Acrylates.

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

Specific examples of the compound represented by the general formula (I) of the photopolymerization initiator (B) used in the present invention include, for example,
2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphine acid methyl ester, 2,6-dichlorobenzoyldisulfide Enilphos phenoxide, 2,6-
And dimethoxybenzoyldiphenylphosphine oxide. Particularly preferred photopolymerization initiators are 2,4,6-trimethylbenzoyl diphenyl phosphine oxide and trimethyl benzoyl phenyl phosphinic acid methyl ester.

One of these photopolymerization initiators may be used alone, or two or more thereof may be used in combination. The usage ratio of the photopolymerization initiator 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 ratio of the photopolymerization initiator is too large, not only the internal homogeneity of the cured product (cured resin) is deteriorated, but also the hue is deteriorated. If the proportion is too small, the composition will not be sufficiently cured.

The organic peroxide (C) used in the present invention has a 10-hour half-life temperature in the range of 50 to 95 ° C. Specific examples thereof include peroxy ketals such as 1,1-bis (tertiary butylperoxy) -3,3,5-trimethylcyclohexane and 1,1-bis (tertiary butylperoxy) cyclohexane, and tertiary. Butyl peroxypivalate, tertiary butyl peroxy (2-
Ethyl hexanoate), peroxyesters such as tertiary butyl peroxyisobutyrate, 3,5,5
Diacyl peroxides such as trimethylhexanoyl peroxide, lauroyl peroxide and benzoyl peroxide; One of these organic peroxides may be used alone, or two or more thereof may be used in combination.

The compounding ratio of the organic peroxide is 0.02 to 0.5 part by weight, preferably 0.05 to 100 parts by weight of the diethylenically unsaturated monomer.
~ 0.3 parts by weight. If the proportion of the organic peroxide is too large, not only does the hue of the cured product deteriorate, but also, in some cases, the mechanical properties of the cured product deteriorate. If the proportion is too small, the composition will not be sufficiently cured.

The curable composition of the present invention may optionally contain an ultraviolet absorber, a polymerization accelerator, a polymerization regulator, an antifogging agent, a release agent, and other additives.

The curable composition of the present invention can be polymerized and cured by appropriately combining polymerization by irradiation with active energy rays and heat polymerization. For example, after polymerization by irradiation with active energy rays such as ultraviolet rays, a method of further performing heat polymerization, a method of performing polymerization by heating simultaneously with irradiation of active energy rays, or a method of performing preliminary heat polymerization and then irradiating with active energy rays is used. It can be polymerized and cured. Among these methods of polymerizing and curing, from the viewpoint of the degree of curing, internal homogeneity, hue and the like of the polymerized and cured product, it is preferable to first irradiate with active energy rays such as ultraviolet rays and then carry out heat polymerization.

As a light source for the active energy ray irradiation, a chemical lamp, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, or the like is appropriately used. In addition, any temperature can be used for the heat polymerization, but it is usually determined in consideration of the decomposition temperature of the organic peroxide used. Generally, temperatures in the range of 70-140 ° C are used.

Hereinafter, examples and comparative examples will be described in more detail. Parts described in these examples mean parts by weight.

The physical properties of the cured products described in these examples were measured using the following test methods.

Light Transmittance Using a test piece having a thickness of 2 mm, the light transmittance of 500 nm light was measured.

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

Optical distortion was measured with a Toshiba Strain Inspector (manufactured by Toshiba Glass Co., Ltd.).

Example 1 Structural formula 100 parts of a sulfur-containing methacrylic compound represented by the formula (hereinafter referred to as a monomer), 0.05 parts of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (referred to as "TMDP"), and t-butylperoxy 0.2 parts of -2-ethylhexanoate (manufactured by NOF CORPORATION) was added, and the mixture was uniformly stirred and mixed, followed by defoaming to obtain a composition.

This composition was injected under a argon atmosphere into a 6 mm thick mold made of a mirror-finished glass plate and silicon rubber. Next, the mold was irradiated with ultraviolet light from a high-pressure mercury lamp with an output of 80 W / cm for 8 minutes (4 minutes each from both sides of the glass) from a distance of 40 cm above the glass surface of the mold. After the obtained cured product was released from the mold, it was heated in an air oven at 100 ° C. for 2 hours to obtain a cured product that was colorless and transparent and had no optical distortion.

This cured product was cut and polished to measure physical properties, processed into dimensions of a measurement sample, and the physical properties were measured.
The results were as shown in FIG.

Example 2 Instead of 100 parts of the monomer used in Example 1, the structural formula Using 100 parts of a sulfur-containing methacrylic compound represented by the following formula (this is referred to as a monomer), the composition was adjusted in the same manner as in Example 1, and the composition was cast and cured in the same manner. A colorless and transparent cured product without distortion was obtained.

 The physical properties of this cured product were as shown in Table 1.

Example 3 Instead of 0.2 parts of t-butyl peroxy-2-ethylhexanoate used in Example 1, 0.2 parts of t-butyl peroxypivalate (manufactured by NOF Corporation) was used, and the other examples were used. A composition was prepared in the same manner as described above, and cast and cured in the same manner to obtain a colorless and transparent cured product having no optical distortion.

 The physical properties of this cured product were as shown in Table 1.

Example 4 Instead of 0.2 parts of t-butylperoxy-2-ethylhexanoate used in Example 1, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (Japan A composition was prepared in the same manner as in Example 1 except for using 0.2 part of Yushi Co., Ltd., and cast and cured in the same manner to obtain a colorless and transparent cured product having no optical distortion.

 The physical properties of this cured product were as shown in Table 1.

Example 5 A composition was prepared in the same manner as in Example 1, except that 0.05 parts of 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester was used instead of 0.05 parts of TMDP used in Example 1. Then, casting and curing were performed in the same manner to obtain a cured product having no optical distortion.

 The physical properties of this cured product were as shown in Table 1.

Comparative Example 1 A composition was prepared in the same manner as in Example 1 except that 0.05 part of benzyldimethyl ketal was used instead of 0.05 part of TMDP used in Example 1, and the composition was cast and cured in the same manner. The cured product was not colorless and transparent, but was yellow.

 The physical properties of this cured product were as shown in Table 1.

Comparative Example 2 In place of 0.05 part of TMDP used in Example 1, 0.5 part of the same compound was used.
The composition was prepared in the same manner as in Example 1, and the composition was cast and cured in the same manner. As a result, the cured product did not become colorless and transparent, had a yellow color, and had optical distortion. .

 The physical properties of this cured product were as shown in Table 1.

Comparative Example 3 The same compound (0.00 parts) was used instead of 0.05 parts of TMDP used in Example 1.
The composition was prepared in the same manner as in Example 1 except that 5 parts were used, and the composition was cast in the same manner. After that, ultraviolet irradiation was performed with the same light source for 16 minutes (8 minutes each from both sides of the glass). A moldable cured product was not obtained.

Comparative Example 4 A composition was prepared in the same manner as in Example 1 except that the t-butylperoxy-2-ethylhexanoate used in Example 1 was not used at all, and the composition was cast and cured in the same manner. As a result, the cured product obtained by heating after demolding was brittle and could not be cut.

Comparative Example 5 In place of 0.2 part of t-butylperoxy-2-ethylhexanoate used in Example 1, 0.5 part of diisopropyl peroxydicarbonate was used.
A composition was prepared in the same manner as described above, and cast and cured in the same manner. The cured product obtained by heating after demolding was brittle and could not be cut.

Comparative Example 6 Instead of 0.2 parts of t-butylperoxy-2-ethylhexanoate used in Example 1, 1.0 part of the same compound was used,
Otherwise, the composition was prepared in the same manner as in Example 1 and cast and cured in the same manner. As a result, the cured product was not colorless and transparent, had a yellow color, and had optical distortion.

 The physical properties of this cured product were as shown in Table 1.

(Effect of the Invention) The photocurable composition of the present invention can provide a cured product excellent in internal homogeneity, surface transfer accuracy, transparency, and hue, and can be advantageously used for manufacturing optical components. .

Continuation of the front page (56) References JP-A-55-13794 (JP, A) JP-A-1-65111 (JP, A) JP-A-55-15471 (JP, A) JP-A-58-77890 (JP) , A) International Publication 90/13579 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 2/50 C08F 20/00-20/70 C08F 290/00-290/14 C08F 299/00-299/08 G02B 1/04

Claims (1)

(57) [Claims] (1) 100 parts by weight of a photopolymerizable diethylenically unsaturated monomer (excluding an oligomer): (In the formula, 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.) At least one photopolymerization initiator represented by the following formula: 0.01-0.
A photocurable composition for optical parts, comprising 3 parts by weight and (C) 0.02 to 0.5 part by weight of an organic peroxide having a 10-hour half-life temperature in the range of 50 to 95 ° C.