JPS635721B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic lens with excellent light transmittance, surface hardness, and scratch resistance. Alternatively, the present invention relates to a plastic lens obtained by curing a component mainly consisting of a reaction product with an unsaturated alcohol having a methacryloyl group.

In general, plastic lenses made from materials such as polycarbonate, polymethyl methacrylate, and polyallyl diglycol carbonate are lighter than conventional glass lenses, have excellent impact resistance, and can be manufactured quickly. It has the advantages of being easy to use and inexpensive, so it can be used for eyeglasses, sunglasses, cameras, etc.
It is widely used as a lens for telescopes, etc.
However, conventionally developed plastic lenses made from the above-mentioned plastic generally have significantly lower surface hardness than glass lenses, so they are susceptible to contact or collision with other objects, or being pulled by other objects. The surface is easily damaged by the action,
Therefore, not only the aesthetic appearance of the product is damaged, but also
It has the disadvantage that optical properties are significantly deteriorated.

Various methods have been proposed to overcome these drawbacks of plastic lenses. For example, a method is known in which a glass material for deposition such as silica, a silicone-based compound, or a melamine-based compound is applied to the surface of a plastic lens, and then cured to form a coating film with improved surface hardness on the surface of the plastic lens. It is being However, although the surface hardness of plastic lenses manufactured by these methods is improved, it is not completely satisfactory, and the adhesion between the coating film and the plastic lens base material is poor, so the interface between them is Cracks occur easily and the paint film peels off easily, and this tendency is particularly noticeable under high temperature and high humidity conditions;
Due to the large difference in refractive index at the interface between the coating film and the plastic lens base material, the transmittance of light rays decreases and optical distortion is likely to occur.In order to form a uniform coating film, the viscosity of the coating material must be adjusted. It is difficult to control the coating process conditions and to control the coating process conditions, which has drawbacks such as increased costs and deterioration of productivity.

The present inventors have conducted various studies to improve the drawbacks of conventional plastic lenses. As a result, a plastic lens made by curing a component mainly composed of a specific polymerizable oligomer having a spiroacetal structure in its molecular structure has been developed. It has high surface hardness, excellent wear resistance, scratch resistance, heat resistance, chemical resistance, impact resistance, light transmittance, dyeability, etc., and has extremely good cutting and abrasive properties during processing. They discovered this and completed the present invention.

That is, the present invention relates to a plastic lens obtained by curing a component mainly consisting of a reaction product of diarylidene pentaerythrite and an unsaturated alcohol having a hydroxyl group and an acryloyl or methacryloyl group in one molecule.

The diarylidene pentaerythrite used in the present invention is represented by the following formula.

Examples of the unsaturated alcohol having a hydroxyl group and an acryloyl group or a methacryloyl group in one molecule that can be a reaction partner with diarylidenepentaerythrite include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
1,6-hexanediol monoacrylate, neopentyl glycol monoacrylate, glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, 2-hydroxyethyl methacrylate, 2
-Hydroxypropyl methacrylate, glycerin dimethacrylate, trimethylolpropane dimethacrylate, pentaerythritol trimethacrylate, etc., and it is necessary to have one hydroxyl group and one or more acryloyl or methacryloyl group in one molecule. .

In the reaction between diarylidene pentaerythrite and unsaturated alcohol, 1 to 2.2 moles of unsaturated alcohol are reacted with 1 mole of diarylidene pentaerythrite.
It is carried out in the presence of an acidic catalyst such as para-toluenesulfonic acid or diethyl sulfuric acid.

The reaction product thus obtained (hereinafter abbreviated as unsaturated spiroacetal oligomer) has 1
It has at least one acryloyl group or methacryloyl group in the molecule, and its molecular weight is from 300 to
1000, preferably 400-600. If the molecular weight is less than 300, the curability is insufficient,
On the other hand, if the molecular weight is 1000 or more, the viscosity is too high and the workability is poor, and curing takes a long time, which is not preferable.

Next, as a representative example, the product obtained by the reaction of diarylidene pentaerythrite and 2-hydroxyethyl acrylate is described, as shown in the following formula [] or formula []. Unsaturated spiroacetal oligomers each having a formula [] having an acryloyl group or a formula [] having an acryloyl group at one end as a main component are obtained.

or The unsaturated spiroacetal oligomers represented by these formulas [] or [] can be easily produced by changing the reaction ratio of diarylidene pentaerythrite and unsaturated alcohol. For example, the unsaturated spiroacetal oligomers represented by the formula [] ] When producing an unsaturated spiroacetal oligomer mainly composed of
When producing an unsaturated spiroacetal oligomer having the formula [] as a main component, 1.0 to 1.2 mol of unsaturated alcohol is preferably used per 1 mol of diarylidene pentaerythritol. The unsaturated spiroacetal oligomer represented by formula [] or formula [] may be used as is, or may be used after removing components such as unreacted unsaturated alcohol.

The unsaturated spiroacetal oligomers represented by formula [] or formula [] may be used alone or in combination.

Further, if necessary, half or less of these spiroacetal oligomers may be replaced with other reactive monomers or oligomers copolymerizable with these spiroacetal oligomers. Other copolymerizable reactive monomers or oligomers may be any monomers that can be copolymerized with the unsaturated spiroacetal oligomer and can be mixed uniformly, such as styrene, methylstyrene, ethylstyrene, and chlorostyrene. Styrenic monovinyl aromatic compounds such as; nitrogen heterocyclic compounds such as vinylpyridine, 2-methyl-5-vinylpyridine, and vinylpyrrolidone; aromatic polyvinyl compounds such as divinylbenzene, divinyltoluene, and divinylnaphthalene; ethylene glycol diacrylate , ethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritate tetraacrylate, and other aliphatic polyvinyl compounds; methyl methacrylate and allyl diglycol carbonate, which have traditionally been known as materials for plastic lenses; Examples include saturated polyesters and epoxy acrylates, among which styrene-based monovinyl aromatic compounds and nitrogen heterocyclic compounds are particularly preferred in terms of improving the dyeability of organic glass. These copolymerizable reactive monomers or oligomers are
They may be used alone or in combination of two or more.

To manufacture the plastic lens of the present invention,
For example, unsaturated spiroacetal oligomers,
A method of injecting into a lens mold with a specific shape designed in advance with the shape of the final product in mind and curing it into the desired shape, or a method of curing it into an arbitrary shape without using a specific mold. Any known method may be used, such as cutting into a desired shape.

The unsaturated spiroacetal oligomer injected into the plastic lens manufacturing mold is cured by heating, light irradiation, ultraviolet ray irradiation, radiation irradiation, or the like.
In this case, it is preferable to add a polymerization initiator to the unsaturated spiroacetal oligomer. Examples of polymerization initiators include benzoin,
Photosensitizers such as benzoin methyl ether, benzoin isopropyl ether, acetophenone, benzophenone, anthraquinone; combination system of benzophenone and aliphatic amine; benzoyl peroxide, azobisisobutyronitrile, methyl ethyl ketone peroxide, t-butyl hydroper Examples include radical generators such as oxide, di-t-butyl peroxide, and dicumyl peroxide. The amount of the polymerization initiator added is 0.1 to 10 parts by weight per 100 parts by weight of the unsaturated spiroacetal oligomer.

Moreover, a polymerization accelerator, a polymerization regulator, an antifogging agent, a mold release agent, and other additives can be added to the unsaturated spiroacetal oligomer as necessary.

Heating unsaturated spiroacetal oligomers,
When curing by light irradiation, ultraviolet irradiation, radiation irradiation, etc., it is preferably carried out in the air or in an inert gas atmosphere at a temperature range from room temperature to 80°C.

Using the unsaturated spiroacetal oligomer of the present invention with a dye or pigment added,
Alternatively, a colored plastic lens can be produced by forming the plastic lens and then dyeing it.

The characteristics of the plastic lens obtained by using the unsaturated spiroacetal oligomer of the present invention are high surface hardness, abrasion resistance, scratch resistance, heat resistance, chemical resistance, impact resistance, It has excellent light transmittance and dyeability, and also has extremely good cutting and polishing properties during processing.

The plastic lens of the present invention is useful as, for example, lenses for eyeglasses, sunglasses, watches, and cameras, as well as lenses for industrial materials such as gas masks and welding protective masks.

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

Example 1 1 mol of diarylidene pentaerythrite and 2-
To 100 parts by weight of a reaction product having a molecular weight of 472, a viscosity of 3.7 poise, and a Gardner color number of 2 to 3 obtained by reacting 2 moles of hydroxypropyl acrylate, 30 parts by weight of trimethylolpropane trimethacrylate and 1 part by weight of benzoyl peroxide. Two glass plates each having a mirror-finished concave surface and a convex surface are combined, and the composition is surrounded by a polyvinyl chloride gasket,
It was poured into a mold held down by a spring-loaded clip. The mold was immersed in a hot water bath at 80°C, and after 30 minutes, the temperature of the liquid in the hot water bath was increased at a rate of 10°C per hour to carry out polymerization. After holding at 90℃ for 3 hours, 120℃
The mixture was transferred to an electric furnace at 0.degree. C., and the state was maintained for 2 hours to complete polymerization.

The light transmittance of the obtained lens was 92%, the impact resistance (distance required for the lens to break when a 50g magnetic ball was dropped) was 60cm, and the surface hardness was 5H.
In the steel wool drag test,
Almost no scratches were observed, and the lens was found to have excellent optical properties, impact resistance, and surface hardness. Further, even when this lens was immersed in trichlene or heated at 100° C. for 2 hours, no change was observed in the lens surface curvature, confirming that it had excellent solvent resistance and heat resistance. Furthermore, the lens of the present invention could be smoothly cut with a diamond wheel and had excellent cutting and polishing properties.

Example 2 The same procedure as in Example 1 was carried out using a composition obtained by adding 30 parts by weight of pentaerythritotetraacrylate and 1 part by weight of t-butylperbenzoate to 100 parts by weight of the reaction product used in Example 1. A lens with a smooth surface was obtained by polymerization.

The resulting lens has a light transmittance of 92% and impact resistance.
It was 43 cm long, had a surface hardness of 6H, and had excellent scratch resistance, solvent resistance, heat resistance, and cutting and abrasive properties.

Example 3 1 mol of diarylidene pentaerythrite and 2-
1 part by weight of benzophenone and 1 part by weight of dimethylaminoethanol are added to 100 parts by weight of a reaction product having a molecular weight of 444, a viscosity of 4.4 poise, and a Gardner color number of 2 to 3 obtained by reacting 2 moles of hydroxyethyl acrylate. The composition was poured into a glass mold having the same surface curvature as in Example 1. Next, from a distance of 10 cm on both sides of the mold.
Polymerization was performed by irradiating ultraviolet light emitted from 2KW high-pressure mercury. After 20 minutes, polymerization was completed and a lens with a smooth surface was obtained.

The resulting lens has a light transmittance of 90% and impact resistance.
60 cm, had high surface hardness, and had excellent scratch resistance, solvent resistance, heat resistance, and cutting and abrasive properties.

Example 4 To 100 parts by weight of the reaction product used in Example 3, 50 parts by weight of ethylene glycol diacrylate, 1.5 parts by weight of benzophenone, 1.5 parts by weight of dimethylaminoethanol, and 0.1 part by weight of Airol OP (trade name) as a mold release agent. Using a composition with the addition of
Polymerization was carried out in the same manner as in Example 3 to obtain a lens with a smooth surface.

The resulting lens has a light transmittance of 90% and impact resistance.
It had a surface hardness of 4H, excellent scratch resistance, solvent resistance, heat resistance, and cutting and abrasive properties.

Example 5 The same procedure as in Example 3 was carried out using a composition obtained by adding 5 parts by weight of vinylpyridine, 1 part by weight of benzophenone and 1 part by weight of dimethylaminoethanol to 100 parts by weight of the reaction product used in Example 3. A lens with a smooth surface was obtained by polymerization.

The resulting lens has a light transmittance of 92% and impact resistance.
54 cm, and had excellent surface hardness, anti-sticking properties, solvent resistance, heat resistance, and cutting and abrasive properties. Furthermore, this lens was dyed with green and light blue 5% acetic acid solutions (dye concentration 20%).
When dyed at 70°C for 2 minutes, the stainability was good.

Claims (1)

[Claims] 1. A plastic lens made by curing a component mainly consisting of a reaction product of diarylidene pentaerythrite and an unsaturated alcohol having a hydroxyl group and an acryloyl group or a methacryloyl group in one molecule.