JPS61170701A - Plastic optical material - Google Patents

Abstract

PURPOSE:To improve impact resistant strength, surface hardness and mechanical strength by forming a titled material of the homo polymer of a specific monomer or a copolymer consisting essentially of said monomer. CONSTITUTION:The above-mentioned material is constituted of the homo polymer of the monomer expressed by the formula or the copolymer consisting essentially of said monomer. A polymn. initiator, for example, benzoyl peroxide, p-chlorobenzoyl peroxide, etc. is mixed at 0.1-10pts.wt. by 100pts.wt. the monomer with the independent monomer expressed by the formula or after mixing the same with various monomers. The mixture is subjected to a deaeration operation of the dissolved oxygen and the operation for removing the absorbed moisture. The mixture is then poured into a preliminarily prepd. mold and is gradually heated by hot wind, warm water, etc. to complete the polymn. The plastic optical material which is a colorless transparent material having >=1.55 refractive index and has excellent optical characteristics as well as the excellent mechanical characteristics such as impact resistance and surface hardness and further the high resistance to solvents and chemicals is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical plastic material whose refractive index can be varied over a wide range, and more particularly to a plastic optical material that has a high refractive index and excellent mechanical strength. It is something.

[Conventional technology]

In recent years, plastics have been attracting attention as optical materials instead of inorganic glass, and their practical use is rapidly progressing. The reason for this is that plastics have excellent properties such as light weight, impact resistance, and processability that inorganic glass does not have. In the field of optical components, glass lenses are being replaced by inorganic glass for safety reasons, especially for eyeglass lenses, which are less likely to break. However, plastic optical materials are subject to many limitations in terms of transparency, optical properties such as refractive index didispersion, weather resistance, scratch resistance, etc., and there are not many types of plastic optical materials.

Glass optical materials currently in practical use are mainly homopolymers of polymethyl methacrylate and diethylene glycol bisallyl carbonate or copolymers with polyfunctional monomers. The polymer of diethylene glycol bisallyl carbonate has properties necessary for eyeglass lenses, such as high light transmittance, high surface hardness and impact resistance, and can be precision polished, so it is used as a material for eyeglass lenses. It has become the mainstream.

On the other hand, the above-mentioned plastic optical materials have a low refractive index, and for this reason, for example, in eyeglass lenses, when compared with the same inorganic glass eyeglass lenses with negative power, the center thickness, edge thickness, and curvature become larger, resulting in poor appearance. However, it has the disadvantage of causing discomfort to the user. In addition, in camera lenses, microscope lenses, etc., lenses with a high refractive index produce chromatic aberration and two spherical aberrations due to the combination of multiple lenses.

K is advantageous in reducing coma aberration and the like.

Polystyrene, polycarbonate, and the like are examples of plastic materials with a high refractive index, but these have drawbacks in heat resistance, chemical resistance, processability, productivity, etc., and are not suitable as optical materials.

Attempts have been made to improve these problems and to develop plastic optical materials that are optically and mechanically superior, and many proposals have been made. For example, in (meth)acrylic plastic optical materials, or (wherein R is hydrogen, methyl group, and
, p + qti−'to*ttdEo ~6o!
Japanese Patent Publication No. 5B-17527 discloses a copolymer using the monomer represented by "Iff)" with other copolymer components.

JP-A-57-85002 2% JP-A-57-1049
Publication No. 01 1% Publication No. 1987-7902, Japanese Patent Application Publication No. 1983
-191708, etc.

[Problem to be solved by the invention]

The above-mentioned (meth)acrylic plastic optical materials have a relatively high refractive index of 1.55 to 1.61, but what they have in common is that in copolymers containing such monomers, , as its content increases, KIR suddenly increases.
＜, mechanical strength is reduced, and impact resistance strength and surface hardness are significantly inferior compared to homopolymers of diethylene glycol bissure and lyl carbonate or copolymers containing them. There is.

Therefore, it is desired to develop a plastic optical material that has a high refractive index and satisfies mechanical strength.

[Means to solve the problem]

In view of the above-mentioned problems, the present inventor has conducted extensive research into plastic optical materials that have a high refractive index, excellent light transmittance, light weight, and high mechanical strength.
We have considered this.

As a result, the present invention was completed based on the discovery that the presence of a carbonate group in the monomer positively affects the above-mentioned properties.

The present invention is based on the following general formula % (wherein R1 is hydrogen or a methyl group; R2 and R3 are alkylene groups having 2 to 6 carbon atoms; and X is chlorine.

Bromine, iodine or an alkyl group having 1 to 4 carbon atoms; Y is a linear or branched alkylene group having 1 to 3 carbon atoms, -
o-, -s-, -5o-, -130! −.

Atomic group selected from Tomi-C-: m + n is 1 or 1~
The present invention is a plastic optical material made of a homopolymer of a monomer represented by the integer 4 (in which +l represents an integer from 0 to 12) or a copolymer having the monomer as an essential component.

The monomer represented by the above general formula of the present invention contains a carbonate group, and a linear or branched alkylene group having 1 to 5 carbon atoms represented by Y in the formula, -o-, -s-, -
It is classified into various compounds according to atomic groups such as 5o-, -so-9-c-, and furthermore, integers such as 1.m and n are appropriately selected and combined with R'', 13, !, and 1.m, n, etc. Various compounds can be exemplified by these. Typical examples of these compounds are o o aIl!3 o, o 0IIIO
0 0Hso
o CHIo
O(H.

0 0 CT1
@0 0
C horse 0 0 C-o
o CHIo
0 cHbo
o C! 11130
0 0H.

0.

■ ■ OO O0 0.

■ ■ ■ OQ OQ OQ These include, but are not limited to.

Since the monomer of the above formula has a carbonate group, it has excellent mechanical strength. The number of carbon atoms in the alkylene group represented by R8 and Rs in the formula is preferably in the range of 2 to 6), and if it exceeds this range, the surface hardness, impact resistance, etc. will be low. Also, the integer ij1 of h+x in the formula
．． 12 is the limit, and if this is exceeded, the mechanical strength tends to decrease.

Therefore, the compound represented by the above general formula of the present invention is a new compound, but the compound can be synthesized by the following method. A typical method is to first react a corresponding difunctional alcohol with excess phosgene to obtain a difunctional cuserformate according to the formula below. Next, the compound represented by the above general formula can be obtained by reacting this difunctional chloroformic acid ester with an alcoholic hydroxyl group-containing (meth)acrylate in the presence of an alkali.

OO R1 (However, in the formula, each symbol has the same meaning as above) Alternatively, as another method, (meth)
By reacting acrylate with excess phosgene, (meth)
It can also be synthesized by synthesizing a chloroformate ester of an acrylate and then reacting it with the corresponding difunctional alcohol.

The plastic optical material of the present invention can be obtained by homopolymerizing the monomer represented by the above general formula or copolymerizing it in combination with other polymerizable monomers. Moreover, two or more types of monomers represented by the above general formula can also be used in combination. A polymer made of the monomer represented by the above general formula has a high crosslinking density, excellent surface hardness and impact resistance, and is also excellent in heat resistance and chemical resistance.

In the present invention, other polymerizable monomers that can be used in combination with the monomer represented by the above general formula include known radically polymerizable polymers such as methyl (meth)acrylate, (
meth)ethyl acrylate, butyl (meth)acrylate,
(meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid glycol, (meth)acrylic acid te)'lhydrofurfuryl, (meth)acrylic acid methyl triglycol, (meth)acrylic acid n -butoxyethyl, methylcarpitol (meth)acrylate, phenyl methacrylate,
Examples of (meth)acrylic esters such as benzyl methacrylate and 7-tyl methacrylate, and other (meth)acrylic esters include methoxydiethylene glycol (meth)acrylate and methoxytetraethylene glycol (meth)acrylate.

phenoxyethyloxyethyl (meth)acrylate,
Phenoxyethyl (meth)acrylate, phenoxyprobil (meth)acrylate.

2-Hydroxyethyl (meth)acrylate.

2-Hydroxypropyl (meth)acrylate.

Phenylglycidyl (meth)acrylate and the like can be used.

Furthermore, other examples include styrene, vinylphenol,
Vinyl compounds such as vinylnaphthalene, vinylcarbazole, vinylpyridine, vinylthiophene, vinylfuran and their halogen or alkyl substituted products, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Tetraethylene glycol dimethacrylate, 1.6
-hexanethiol dimethacrylate), 1,5-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, bisphenol A-dimethacrylate, bisphenol S-dimethacrylate, bisphenol ketone dimethacrylate, bisphenol sulfide dimethacrylate, 2-hydroxy 1. 5-dimethacryloxypropane, 2,2-bis(4-(methacryloxyethoxy)phenyl), 2,2-bis[
4-(methacryloxyjethoxy)phenyl]propane, trimethylolpropane tri(meth)acrylate,
Tetramethylolmethane tri(meth)acrylate.

tetramethylolmethanetetra(meth)acrylate,
Bisphenol-diglycidyl (meth)acrylate)
, 1,2,6-hexanetriol (meth)acrylate
), 2.2'bis[methacryloxy (glycidyl 2
-Propoxy) phenyl] polyfunctional (meth) such as propane
Acrylates.

Allyl esters such as allyl phthalate, allyl isophthalate, allyl terephthalate, allyl hetate, allyl cyanurate, allyl incyanurate, allyl maleate, allyl tumafurate, allyl naphthalenedicarboxylate, allyl methacrylate, and their derivatives. Examples include substituted carbonates and allyl carbonates represented by diethylene glycol bisallyl carbonate. Several types of such monomers may be used in combination.

In the copolymer, the composition ratio of the monomer represented by the general formula of the present invention and the above-mentioned various monomers is determined based on the optical properties 2 mechanical properties required for the desired optical material and the polymerization required during production. Although it cannot be limited uniformly because it varies depending on conditions, etc., there are 5 monomers represented by the above general formula! It is desirable that the weight be at least 10% by weight, preferably at least 10% by weight. If the amount is less than this, the resulting copolymer will not have the effect of improving surface hardness, impact strength, heat resistance, and chemical resistance.

Homopolymerization or copolymerization of the monomers represented by the above general formula of the present invention can be carried out by a known radical polymerization method.

Photopolymerization method etc. can be adopted. That is, after the monomer represented by the above general formula is used alone or mixed with the above various monomers, a polymerization initiator such as benzoyl peroxide, p-
Chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybiparate, acetyl peroxide, diisopropyl peroxydicarbonate, lauroyl peroxide, decanoyl peroxide, di-2-diethylhexyl silver oxide oxydicarbonate) + ta
11 to 10 parts by weight of rt-butylperoxy-2-ethylhexanate or the like is mixed with 100 parts by weight of the monomer. At this time, it is preferable to perform a degassing operation for dissolved oxygen and an operation for removing absorbed moisture. Next, the mixture is poured into a previously prepared container and heated gradually using hot air, hot water, etc., to complete the polymerization. At this time, the polymerization is stopped midway, and the prepolymer is taken out of the mold and reused.
Polymerization can also be completed using a prepolymer and the polymerization initiator.

The polymerization temperature and time cannot be uniformly determined because they vary depending on the composition and reactivity of the monomers used and the type and amount of the polymerization initiator, but the polymerization time is approximately 5°C to 100°C for 1 hour to 100 hours. Preferably, the polymerization is allowed to complete.

Further, the above homopolymerization or copolymerization can also be carried out by a photopolymerization method. That is, a photopolymerization catalyst such as benzine, 2-methylbenzoin, benzoin methyl ether, benzoin isopropyl ether, acetoin, butyroin, toluoin is added to the monomer or monomer mixture.

Q, 01 to 10 parts by weight of benzylbenzophenone, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, azobisinobutyronitrile, azobis-2,4-dimethylvaleronitrile + 1-chloroanthraquinone, 1,4-naphthoquinone, etc. Then, polymerize it by irradiating it with an ultraviolet lamp, mercury lamp, etc. In this case, the above-mentioned polymerization initiators can also be used together.

When producing the plastic optical material of the invention, known additives can be added in order to impart useful properties to the material or to avoid undesirable phenomena.

Such additives include, for example, 2-hydroxy-4-
177 Absorbent, hindered phenol, such as n-octoxybenzophenone, benzotriazole substituted product.

Antioxidizing agents such as hindered amines, quaternary ammonium salts, and antistatic agents such as nonionic surfactants are used. These additives may be added singly or in combination to the monomer or monomer mixture before the start of polymerization, or may be added to the prepolymer during the polymerization.

〔Example〕

The present invention will be explained in more detail with reference to Examples, but these are merely examples of embodiments of the present invention and, of course, do not limit the present invention.

The method of measuring the characteristics in the examples is as follows. Refractive index: Measured at 20°C using an Atsube refractometer.

Solvent resistance: Lens pieces were left in acetone, isopropyl alcohol, Freon 113, and water for 7 days at room temperature, and no change in the weight of the lens pieces was observed in any of the solvents, and the surface KID and Those with no cracks were rated as #1 Good (○).

Impact resistance: A lens with a center wall thickness of 2 mm was tested according to the IPDA standard, and those that passed were rated 1 good and 1 (○).

Surface hardness: Measured according to J.E. (K5400).

Example 1 99 parts by weight of a monomer represented by 0 0 0 Hg was heated to 60°C, and 1 part by weight of di-t-butyl peroxide (1 part butyl D', a product of Nippon Oil & Fats Co., Ltd.) was mixed therewith. , poured into a lens casting mold consisting of two pieces of spherical glass with a diameter of 70 cm and a gasket made of polytetrafluoroethylene resin, and heated sequentially at 80°C for 2 hours, 100°C for 2 hours, and 120°C for 10 hours. All were thermally polymerized in a hot air dryer. The mold was removed from the dryer, and the polymer was peeled off from the mold to obtain a plastic lens.

The thus obtained lens has a refractive index of 1.578, solvent resistance and impact resistance of 1 good (0), a surface hardness of 4H, and a mechanical hardness of 315"*40 fS [l
1fi'7'&Lrfi.

It had certain characteristics.

Examples 2 to 4 Monomers represented by the following formulas [11 to (IT) (1)] were thermally polymerized in the same manner as in Example 1 to obtain plastic lenses.

The refractive index, solvent resistance, impact resistance, and surface hardness of the lens thus obtained were measured, and the results are shown in Table 1.

Example 5 Example 1 except that a mixture of 50 parts by weight of the monomer represented by the above formula and 50 parts by weight of benzyl methacrylate was used.
A plastic lens was obtained by thermal polymerization in the same manner as above.

The refractive index, solvent resistance, impact resistance, and surface hardness of the obtained lens were measured, and the results are shown in Table 1.

Examples 6 to 9 Thermal polymerization was carried out in the same manner as in Example 1 except that a mixture of the monomer represented by formula [I] and other monomers shown in Table 1 was used, I got a plastic lens.

The refractive index, solvent resistance, impact resistance, and surface hardness of the obtained lens were measured, and the results are shown in Table 1.

Comparative Examples 1 to 5 Diethylene glycol bisallyl carbonate (hereinafter abbreviated as 0R-59) used as a plastic optical material, other monomers shown in Table 2, and mixtures thereof were thermally polymerized in the same manner as in Example 1. Then, a plastic lens was obtained.

The refractive index, solvent resistance, impact resistance and surface hardness of the obtained lens were measured, and the results are shown in Table 2.

〔Effect of the invention〕

A plastic optical material comprising a monomer represented by the above general formula of the present invention or a polymer or copolymer obtained by polymerizing the monomer and another polymerizable monomer has a refractive index of 1.55. It is a colorless transparent body having the above properties and has excellent optical properties.

Moreover, it has excellent mechanical properties such as impact resistance and surface hardness, as well as solvent resistance and chemical resistance, and has properties that are stronger than conventional plastic optical materials. Therefore, as a plastic optical material with a high refractive index, it is possible to provide plastic lenses that can be made thinner and lighter and have excellent mechanical strength in the field of various optical lenses such as eyeglass lenses and camera lenses. It is effective.

Claims (1)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, R^1 is hydrogen or methyl group; R^2 and R
^3 is an alkylene group having 2 to 6 carbon atoms; X is chlorine, bromine,
Iodine or an alkyl group having 1 to 4 carbon atoms; Y is a linear or branched alkylene group having 1 to 3 carbon atoms, -O-, -S-, -SO-
, -SO_2-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼; m+n is 0 or an integer from 1 to 4; k+
1 represents an integer of 0 to 12) A plastic optical material comprising a homopolymer of a monomer represented by the following formula or a copolymer having the monomer as an essential component.