JPS5986616A - Production of high-refractive index resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having a high refractive index (>=1.58) and being excellent in surface hardness, solvent resistance, high-speed moldability, etc., by copolymerizing a specified epoxy(meth)acrylate with a specified polyfunctional (meth)acrylate. CONSTITUTION:Epoxy(meth)acrylate is produced by reacting (i) an epoxy resin prepared by condensing a polyhydric phenol having two benzene nuclei in the molecule with an epihalohydrin with (ii) acrylic or methacrylic acid. The desired high-refractive index resin is produced by curing the above epoxsyacrylate with a polyfunctional (meth)acrylate other than the above epoxy(meth)acrylate by radical polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a high refractive index resin having a refractive index of 15 ψ or more, and particularly provides a method for producing a high refractive index resin with excellent high-speed moldability. Inorganic glass has been used in many applications due to its excellent transparency, hardness, scratch resistance, and weather resistance, but on the other hand, it has the disadvantages of being brittle, easily broken, and heavy. ing. On the other hand, organic glasses have advantages over inorganic glasses such as lightness, safety, processability, dyeability, etc., and currently used are polymers of polymethyl methacrylate, polycarbonate, diethylene glycol diallyl carbonate, etc. Especially in applications such as eyeglass lenses,
There are extremely high expectations for organic glass in terms of lightness and safety (resistance to breakage). However, polystyrene (refractive index 1.59) and polycarbonate (refractive index 1.59), both of which have a high refractive index, are thermoplastic polymers, so the molding method is different from the casting method, so they are used for many purposes such as lenses. It is not suitable for use in low-volume production of various types, and has poor heat resistance and solvent resistance, so its uses are naturally limited.

On the other hand, diethylene glycol diallyl carbonate polymer made by cast molding has a low refractive index (refractive index of 1.4
99), which has the disadvantage of being thicker than inorganic glass lenses. In order to improve this drawback, several prior art techniques have been disclosed for increasing the refractive index. For example, JP-A-55-13747, JP-A No. 56-61
No. 411, No. 56-61412, No. 57-2311, No. 57-2312, No. 57-23611, No. 57
-28115, 57-28116, 57-28
No. 117 and No. 57-28118 can be mentioned. However, in all of these prior arts, the desired cured product is obtained by injecting a homogeneous mixture of a monomer composition and a polymerization initiator into a casting jig and then performing thermal polymerization over a long period of time. Therefore, the rotation of the casting jig is slow, requiring a large number of casting jigs, and the energy required for polymerization, which takes a long time, is enormous, resulting in extremely low productivity.

In view of the shortcomings of the prior art, as a result of intensive research, the present inventors have found that by copolymerizing a specific epoxy (meth)acrylate and a specific polyfunctional (meth)acrylate, a high-quality product can be obtained in an extremely short period of time. It was discovered that a high refractive index resin having a refractive index and excellent surface hardness, solvent resistance, heat resistance, impact resistance, dyeability, etc. can be obtained, and the present invention was achieved. Therefore, an object of the present invention is to provide a method for producing a high refractive index resin having a refractive index of 15 or more.

Another object of the present invention is to provide desirable transparency as an optical lens;
An object of the present invention is to provide a method for producing a high refractive index resin for lenses that has no coloration.

Yet another object of the invention is excellent surface hardness.

The high refractive index resin of the present invention has general formula (1) or (6) or
is H or CH3R3 is a divalent hydrocarbon group Y and Y'
may be the same or different H or CI! or■n
represents 1 to 5] Epoxy (meth) produced by reacting an epoxy resin obtained by the condensation of a polyhydric phenol having two benzene nuclei in the molecule represented by the following with acrylic acid or methacrylic acid ) Acrylate and general formula a
t+~□ or [In the above general formulas (e) to (a), W is H or C
H.

R4 is a hydrocarbon group having 2 to 4 carbon atoms or a hydrocarbon group having an ether bond, and may be substituted with CH3 or OH.

W is 0 or S or SO2, z, z' is H or an alkyl group or C1, or Brs or an alfxyl group, P is an integer of 1 or 2, q is an integer of 1 or 2, R4)rn-〇-(However, m
is 1 to 2)] having a benzene nucleus and/or a naphthalene nucleus in the molecule (1 to 2)
) or a polyfunctional (meth)acrylate other than (6) by radical polymerization.

The epoxy (meth)acrylates represented by the general formulas (1) and (6) may be used alone or in combination. Similarly, general formula (g) ~
The polyfunctional (meth)acrylates represented by M may be used alone or in combination.

Examples of epoxy (meth)acrylates represented by general formulas (1) and (6) include epoxy resins obtained by reacting bisphenol A1 bisphenol F or brominated bisphenol A with epichlorohydrin, and acrylic acid or methacrylic acid. It is produced by reacting. Examples include epoxy (meth)acrylate.

Examples of the polyfunctional (meth)acrylates represented by general 2~(a) include bis-(β-acryloyloxyethyl) inphthalate, diacrylate of 2,2'-dihydroxynaphthalene/ethylene oxide adduct, 2
．． Examples include 2'-bis(β-acryloyloxyethoxy)biphenyl.

The mixing ratio of epoxy (meth)acrylate and polyfunctional (meth)acrylate used in the present invention is not particularly limited, but generally the weight ratio is epoxy (meth)acrylate: polyfunctional (meth)acrylate) = =l:Q, 1
used in a ratio of ~10. If the amount of epoxy (meth)acrylate is large, the impact resistance will be high, and if the amount of polyfunctional (meth)acrylate is large, the surface hardness will be high. A high refractive index resin can be obtained by copolymerizing epoxy (meth)acrylate and polyfunctional (meth)acrylate, but other polymerizable monomers are also copolymerized to improve workability, impact resistance, dyeability, etc. Polymerization is also possible.

The following polymerizable monomers are added for this purpose:
or a mixture thereof. The amount of the polymerizable monomer added is 10% or less of the total amount by weight, and for example, the following compounds are used.

Diethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, diarylidene pentaerythritol diacrylate.

In addition, anti-yellowing agents (triphenylphosphine, etc.), leveling agents (fluorinated surfactants, etc.),
A UV absorber (such as 2-(2'-hydroxy-51-methylphenyl)-2H-benzotriazole) may be added to the extent that it does not interfere with curing.

Furthermore, the copolymer according to the present invention is produced by radical polymerization, but in addition to thermal polymerization, polymerization methods using active energy rays such as ultraviolet rays and γ rays can also be used. It is also possible to obtain a high refractive index resin without optical distortion in a short time.

In particular, polymerization using ultraviolet rays has the advantage that copolymerization can be carried out in a short time and production can be significantly increased, and is particularly suitable in the present invention.

When carrying out thermal polymerization, common radical polymerization initiators such as benzoyl peroxide, diisopropyl peroxydicarbonate, and azobisisobutyronitrile can be used.

In the case of ultraviolet curing, commonly known luhenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-hydroxy-2-benzoyl-propane, azobisisobutyronitrile, benzyl,
Photosensitizers such as thioxanthone can be used.

These radical polymerization initiators or photosensitizers are used in an amount of about 5% by weight at most based on the copolymer composition.

Furthermore, in order to produce the lens according to the present invention, a homogeneous transparent mixture obtained by adding a polymerization initiator to a copolymerization composition is injected into a lens mold assembled from a glass mold and a gasket, heated, and exposed to ultraviolet rays. This is done by irradiating with irradiation or other active energy rays and then hardening and demolding.

Furthermore, the refractive index of the resin produced according to the present invention is
Although it varies depending on the blending ratio of raw materials, it is 1.58 to 1.65
It is a general transparent thermosetting resin (urea resin 1.54
, melamine resin 1.55, alkyd resin 1.55, diallyl phthalate resin 1.56, and diethylene glycol bisallyl carbonate resin 1°499). The scope of its use can be expanded to include camera lenses and other optical elements in addition to eyeglass lenses, and its industrial significance is great.

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

Example 1 380 g of an epoxy resin with an epoxy equivalent of 190 obtained by condensation of bisphenol A and epichlorohydrin (
1 mol) and 144 g of acrylic acid (2 mol of (11)) at 100°C in the presence of a lithium chloride catalyst.
Epoxy acrylate (6) was produced by heating and reacting at 120° C. for 2 hours. 100 parts by weight of this epoxy acrylate and 120 parts by weight of bis-(β-acryloyloxyethyl) inphthalate obtained by esterifying 1 mole of isophthalic acid with 2 moles of hydroxyethyl acrylate (1 m2) were mixed, and the mixture was heated to a sufficiently uniform temperature at 70°C. After that, 0.5% by weight of dimethoxyacetophenone and 0.1% by weight of triphenylphosphine (anti-yellowing agent) were dissolved in this.Into a glass eyeglass lens mold preheated to 70°C. After injecting the curable resin liquid obtained above and defoaming, it was irradiated with ultraviolet rays from a distance of 15 (M) using a 2KW high-pressure mercury lamp.The glasses were completely cured in 20 seconds and had no optical distortion when removed from the mold. I got the lens.

According to the present invention, the curing time was short as described below, and the obtained lenses had a large refractive index, high surface hardness, and good dyeability.

(To) Curing time Refractive index Pencil hardness Dyeing method Invention (light curing) 20 seconds 1585 4H◎■ The undyed property was determined by the following method.

For comparison, 0.5% by weight of dimethoxyacetophenone and 0.1% by weight of triphenylphosphine were dissolved in diethylene glycol bisallyl carbonate, and the solution was poured into the same lens mold as in Example 1, and the solution was prepared under the same conditions. When irradiated with ultraviolet rays, curing was not completed even after 10 minutes of irradiation, and no lenses were obtained. A lens with a thickness of 1/4 inch was immersed in a 0.2% Disperse Brown 3 aqueous solution, immersed and dyed at 92° C. for 20 minutes, pulled up, thoroughly washed with water, and dried. The value of E in the formula % was determined from the Okel light transmittance of 55 (h+g) of this dyed lens.

If E is 1.0 or more, the stainability is OE.If E is 0.5 or more and less than 1.0, the dyeability is OE.
If the dyeability was less than 5, the stainability was rated as ×.

Example 2 620 g of epoxy resin with an epoxy equivalent weight of 310 obtained by condensation of bisphenol A and epichlorohydrin
(1 mol) and 144 g (2 mol) of acrylic acid were reacted in the presence of 0.8 g of diethylamine hydrochloride catalyst at 100°C for 1 hour and then at 120°C for 2 hours to produce epoxy acrylate (1). . On the other hand, it was obtained by adding ethylene oxide to 2,2'-dihydroxynaphthalene. Diacrylate (v) was produced by esterifying 2°2'-dihydroxyethyloxynaphthalene with acrylic acid. 100 parts by weight of (1), 120 parts by weight of M, 50 parts by weight of trimethylolpropane triacrylate, and 1.2 parts by weight of benzoyl peroxide were mixed well, and 0.1% by weight of trimethylammonium peroxide was added as an anti-yellowing agent. Phenylphosphine and 0.2% by weight (7) 2-(2-hydroxy-57-methyl-phenyl)-2H-benzotriazole were added as an ultraviolet absorber and heated to 50°C to form a homogeneous solution. . This composition was poured into a lamp lens mold, degassed, and then placed in a 90° C. heating oven for 3 hours. The composition was completely cured and demolded to yield a lamp lens. For comparison, the obtained lens was compared with C obtained by conventional thermal polymerization
Compared to the R-39 lens (made of diethylene glycol bisallyl carbonate), the lens according to this example takes a shorter curing time as shown below, and the obtained lens has a large refractive index and a high surface hardness. The dyeability was also good.

Curing time Refractive index Pencil hardness Dyeing c Invention (thermal curing) 3 hours 1.601 3H◎
CR-39 (//) 10 lucidity ratio 1.499
2 HO0 was measured by the method described in Example 1.

Example 3 Example 1 except that 2,2′-(β-acryloyloxyethoxy)biphenyl(t)M was used instead of bis-(β-acryloyloxyethyl) inphthalate used in Example 1. Spectacle lenses were obtained in exactly the same manner as above.

According to the present invention, lenses were obtained with a short curing time, and the obtained lenses had a large refractive index, high surface hardness, and good dyeability.

Patent applicant: Showa Denko Co., Ltd. Showa Kobunshi Co., Ltd. Representative Patent Attorney Sei Kikuchi (mistake 143-

Claims (1)

[Claims] Epoxy (meth)acrylate produced by reacting an epoxy resin obtained by condensing a polyhydric phenol with two benzene nuclei in the molecule with epichlorohydrin and acrylic acid or methacrylic acid, and a benzene nucleus and/or naphthalene in the molecule. The above epoxy with a core (
A method for producing a high refractive index resin, which comprises copolymerizing and curing a polyfunctional (meth)acrylate other than meth)acrylate by radical polymerization.