JPS5986001A - Method for coating surface of plastic lens - Google Patents

Abstract

PURPOSE:To form a protective film with superior surface hardness, adhesive strength and durability on the surface of a plastic lens by coating the surface of the lens with a specified thermosetting resin composition and by irradiating active energy beams to cure the composition. CONSTITUTION:The surface of a plastic lens made of polymethyl methacrylate or bisphenol type polycarbonate resin is coated with a composition consisting of finely powdered silica (A), an oligomer (B) of acrylate or methacrylate having an acryloyl or methacryloyl group in the molecule, a blend (C) of multifunctional allyl or allylidene compound with multifunctional thiol, and a multifunctional acrylic or methacrylic monomer (D). The resulting film is cured by irradiating active energy beams. The component D is preferably used by 10-400pts.wt. per 100pts.wt. all of other resin components. The hardness of the film can be improved.

Description

Detailed Description of the Invention The present invention involves applying a curable resin composition containing finely powdered silicon oxide to the surface of a plastic lens made from polymethyl methacrylate or bisphenol-based polycarbonate resin, and then irradiating it with active energy rays. The present invention relates to a coating method for plastic lenses, which is characterized in that the coating is cured by coating the lens, and provides a method for surface treatment of plastic lenses, in which a coating film having excellent surface hardness, adhesion, and durability is formed on the lens surface by this method. It is. Plastic lenses have a disadvantage that their surface hardness is lower than that of glass lenses, and they are easily scratched during use. For this reason, the lens surface is often coated with a hard coat to increase the surface hardness and make it less likely to be scratched.

Conventional lens hard coating methods have been used in two ways. One is to form a protective coating on the surface of a plastic lens. The most typical method is silicone corting, and silanol, etc. This is a method in which a solution or emulsion of a plastic lens is applied to the surface of a plastic lens, and the solvent is evaporated and condensed by heating to form a coating film on the lens surface.However, the surface hardness obtained with this method is still insufficient. Also, there are drawbacks such as poor adhesion between the coating film and the plastic lens, and the need for a brimer to form the coating film.Another method is vapor deposition.

This is a method of forming an inorganic film such as aluminum oxide on the lens surface. However, this method is expensive due to poor productivity, and the vapor-deposited film has poor adhesion to the lens.
Furthermore, there are drawbacks such as the need for a top coat. The present invention has been developed by fully considering the above-mentioned conventional techniques, and provides a protective film that is easy to form, has high hardness, is durable, and has excellent adhesion. The present invention was completed by discovering a coating method with high productivity.

That is, the present invention applies to the surface of a plastic lens manufactured using polymethyl methacrylate or bisphenol-based ibolycarbonate resin.

(1) finely powdered silicon oxide, (2) at least one (meth)acrylate oligomer containing an acryloyl group or methacryloyl group in the molecule, and/or (3) a polyfunctional allyl or allylidene compound and a polyfunctional thiol. (4) a polyfunctional acrylic or methacrylic monomer, and (5) a photosensitizer in some cases, and then apply an active energy ray to cure the composition. The present invention relates to a coating method characterized by:

By applying a composition comprising dispersed silicon oxide to the surface of a plastic lens made of polymethyl methacrylate or bisphenol-based polycarbonate resin, and curing it on the spot by irradiation with active energy rays,
The present invention provides a plastic lens surface coating method for forming a protective surface coating film on the plastic lens surface that is transparent, has good adhesion to these plastics, and is highly durable. Furthermore, since these compositions have good fluidity, they are suitable for coating lenses using various coating methods.

The reason why the polyfunctional acrylic or methacrylic monomer component (4) is blended with the oligomer component (2) and/or the monomer component (3) in the present invention is as follows. Generally, polymers obtained by curing oligomer component (2) and monomer component (3) have excellent adhesion to lenses, but lack hardness. - The polymer obtained by curing the polyfunctional acrylic or methacrylic monomer component (4) has excellent hardness, but is brittle and has insufficient adhesion. Oligomer component (2) and/-strapping monomer component (3)
By using the polyfunctional monomer component (4) in combination, the characteristics of both are further exhibited. Furthermore, the fine powder silicon oxide of component (1) is combined with the oligomer component (2), which is a resin component, and/or
Since mafc is well dispersed in the mixture of monomer components (3) and (4), the coating liquid has excellent stability.

The curing time is sufficiently short, from 1 second to 10 minutes. The hardening composition according to the present invention has high hardness because it contains silicon oxide, and also contains monomers and
Since it contains the component (component (4)) and provides a cured product with a high degree of crosslinking, the cured coating film has excellent hardness and adhesion. Furthermore, since a sufficiently hardened protective film can be formed by irradiation with active energy rays for a short period of time as described above, productivity is extremely high. Incidentally, the conventionally used coating method requires a baking operation at 100° C. for 16 hours.

The finely divided silicon oxide used as component (1) in the present invention is
As the silicon oxide, fine particles having a particle size of several tens to several hundred angstroms are used. These silicon oxide particles may be surface-treated with a run-coupling agent or the like so that they can be easily dispersed in an organic liquid. A commercially available product (organosilica sol) dispersed in a strained organic liquid can also be used. The fine particles of silicon oxide become transparent after being coated.

The finely divided silicon oxide is used by being added, mixed, and dispersed in a mixture consisting of the oligomer component (2) and/or the monomer component (3), and the monomer component (4).

Examples of (meth)acrylate oligomers having acryloyl or methacryloyl groups in the molecule used in component (2) include compounds having two or more epoxy end groups in five molecules (e.g. epichlorohydrin-bisphenol A condensate, molecular weight 340- 3000) with acrylic acid or methacrylic acid, a polyester oligomer with a molecular weight of 200 to 3000 having a carboxyl group or hydroxyl group at the end, acrylic acid, methacrylic acid, acrylic acid chloride, methacrylic acid chloride, hydroxyalkyl Polyester (meth)acrylate esterified with acrylate or hydroquine alkyl methacrylate, polyether (meth)acrylate esterified with acrylic acid, methacrylic acid, acrylic acid chloride, or methacrylic acid chloride ( Meth)acrylate, a urethane (meth)acrylate obtained by esterifying a urethane oligomer with a molecular weight of 200 to 3000 with a carboxyl group or hydroxyl group at the end with acrylic acid, methacrylic acid, acrylic acid chloride, methacrylic acid chloride hydroxyalkyl acrylate or hydroxyfurkyl methacrylate. , diarylidenepentaerythritol (meth)acrylate obtained by reacting diarylidenepentaerythritol with hydroquine alkyl acrylate or hydroxyalkyl methacrylate, and the like. These may be used alone or in combination of two or more.

By changing the reaction conditions (for example, molar ratio and reaction rate), the above component (2) can be obtained with (meth)acryloyl group at one end as the main component, or with (meth)acryloyl group at both ends. However, in the present invention, considering the crosslinking density of the film of the cured product, on average 1.5 or more in one molecule,
Preferably, those having two or more (meth)acryloyl groups are preferred. The blending ratio of the polyfunctional allyl or aliphatic compound and polyfunctional thiol as the component (3) is preferably 1:0.542.0 in terms of equivalent ratio. This mixture may be used by mixing both components in the above ratio, and then mixing the oligomer component (2) and the oligomer component (4) therewith. Examples of the polyfunctional allyl or allylidene compound include diallyl tucrate, diallyl adipate, diallyl succinate, triallyl isocyanurate, and diallylidene pentaerythritol. Examples of polyfunctional thiol compounds include ethylene dithioglycol, trithioglycerin, ethylene glycol dithioglycolate, trimethylolpropane trithioglycolate, pentaerythritol trithiopropionate, pentaerythritol tetraacrylate, and the like.

Polyfunctional acrylic or methacrylic IJ as the (4) component
Examples of 7L/monomers include ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Flobylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, dipropylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol diacrylate Methacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate-1-, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol triacrylate, dipentaerythritol trimethacrylate, etc. can be mentioned.

The photosensitizer, which is the fifth component, includes pentuphenone, benzyl, benzoin, dimethoxyacetophenone,
Examples include benzoin methyl ether, pentisopropyl ether, thioxanthone, methylolumpenzyl benzoate, and azobisalkylonitrile.

These photosensitizers are preferably used in the present invention because they promote photopolymerization, especially when ultraviolet rays are used.
However, if other active energy rays are used, polymerization can proceed sufficiently without using them.

In the present invention, the blending ratio of ingredients such as dough is component (1), which is 1 part by weight of finely powdered silicon oxide, per 100 parts by weight of the total blend.
60 parts by weight may be used; if the amount of component (1) is less than this, the resulting coating film will not have sufficient hardness, and if it is more than stiff, the adhesion will be poor. The photosensitizer, which is the fifth component, is used during ultraviolet curing, and is added in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the total composition.

Next, the polyfunctional acrylic or methacrylic monomer, which is the important component (4) for improving the hardness of the coating film obtained as a resin component used in the present invention, is a component (4) of the resin component used in the present invention.
3) or 10 to 400 parts by weight per 100 parts by weight of a mixture thereof. If the amount of component (4) is less than stiffness, the resulting coating film will have insufficient hardness, and if more than this amount is used, the resulting coating film will become brittle and have insufficient adhesion.

There is no limit to the blending ratio of the (2) component and the (3) component,
Each may be used in 100 parts, or in an appropriate mixing ratio. As other components to be added to the composition used in the present invention, a solvent can be used to lower the viscosity of the coating liquid so that it can be applied thinly. Examples of solvents that can be used include methanol, ethanol, ingropanol, acetone, and ethyl acetate.

In addition, commonly used additives such as pigments, ultraviolet absorbers, leveling agents, and antistatic agents can be used.

The composition according to the present invention obtained as described above can be coated onto the surface of a plastic lens using any conventional coating method such as roller coating, flow coating, dipping, brushing, spray coating, etc. You can. After coating, the coating film is cured by irradiation with active energy rays, but if the curing composition contains a solvent, the solvent is evaporated by ventilation or the like, and then active energy rays are irradiated to cure the coating. The thickness of the coating is generally 1 to 50 microns. 1. Depending on the case, it may be coated on top of a primer.

The active energy rays used in the present invention include ultraviolet rays, X-rays, gamma rays, electron beams, etc., and the appropriate irradiation time is 1 second to 10 minutes. After irradiation, after-curing may be performed by heating to 150° C. or lower to remove strain or to complete polymerization.

As is clear from the following examples, the coating film obtained by the method of the present invention has good adhesion to the surface of a plastic lens, has a hardness of 100%, and forms a highly durable protective film. The pencil hardness is 21-I, the adhesion is 100/100 in the goblin test, and the i-t Kutt shows excellent results with no change after 500 hours of irradiation in the weather meter test.

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

Example 1 Polymethyl methacrylate produced by injection molding
After the resulting lens was washed and dried, it was spray coated with the following curable composition to a finished thickness of 7 microns.

550 weight of finely powdered silicon oxide (component ()) having a particle size of 70 was dispersed at 60°C in a resin liquid having the following composition.

Diarylidene Pentaerythritol 30 parts by weight (Component (3)) Pentaerythritol Tetrathiogtrimethylol Propane Triacrybenozoin Itepropyl ether coated lens was heated for 4 seconds with an irradiation device consisting of two 21 W high pressure mercury lamps connected together. The coating was cured by irradiation. This lens has improved surface hardness compared to before treatment, and can be processed using the conventional Bartco-1 method. lens (after coating the same lens with methylphenylsilanol,
(baked at 100℃ for 16 hours), hardness,
It had excellent adhesion and durability.

Before processing Example 1 Lens processing of methylphenylsilanol lens, 7's pencil hardness 2H4H' 3H Adhesion -100/100 60/1
00 (Goban test) Example 2 After washing and drying a lens made of bisphenol A polycarbonate manufactured by injection molding, it was coated with the following curable composition by a dipping method and coated with hot air at 50°C. The solvent was evaporated. Thickness of finishing coat - amount)
was adjusted so that it was 5 microns.

Urethane acrylate oligomer (Thiokol Co., Ltd., Uvisan, 783. Acrylo 30 parts by weight Contains 2 yl groups in 1 molecule) (Component (2)) A lens coated with pentaerythritol triacrylate was exposed to ES11 in a nitrogen stream.
8 inch electrocarteer (ES I 18 In
ch Electrocurtain) [Energy 5science Inc.
Both sides were irradiated with accelerated electrons to cure the material. The irradiation time was 15 seconds on each side. The obtained lens had improved surface hardness compared to before treatment, and was superior in hardness, adhesion, and durability compared to conventional aluminum oxide vapor deposition methods.

Before processing Example 2 Aluminum oxide lens Lens with vapor-deposited ram Pencil hardness WB 21 (H Example 3゜After washing and drying the same polymethyl methacrylate lens as in Example 1, the following curable composition was applied. A quick two-coat was applied, and the final coating thickness was -+"t' micron.

40 parts by weight of finely powdered silicon oxide (component (1)) having a particle size of 50 large was dispersed in a resin liquid having the following composition.

Diallyl phthalate (component (3)) 3
0 u benzoin itegropylether (Seishu 5))
2. The Ott coated lens was photocured under the same conditions as in Example 1. This lens has improved surface hardness compared to before treatment, and is also better than lenses made using the conventional node coating method (the same lens was coated with methylphenylsilanol and then baked at 100°C for 16 hours). It had excellent adhesion and durability.

Before processing Example 3 Methylphenylene Les/Z lens Runlanol processing lens Pencil hardness 2H41-I 3H Patent applicant: Showa Denko Co., Ltd. Showa Kobunshi Co., Ltd. Representative Patent Attorney Sei Kikuchi

Claims (1)

[Claims] On the surface of a plastic lens manufactured using polymethyl methacrylate or bisphenol polycarbonate resin. (1) finely powdered silicon oxide; (2) at least one (meth)acrylate oligomer containing an acryloyl group or a methacryloyl group in the molecule; and/or. (3) A blend of a polyfunctional allyl or allylidene compound and a polyfunctional thiol. (4) A multifunctional acrylic or methacrylic monomer, and (5) In some cases, a photosensitizer. A coating characterized by applying a composition and curing the composition by irradiating the stiffness with active energy rays. Law.