JPH0699664B2 - Hard coating agent and plastic optical products - Google Patents

Description

TECHNICAL FIELD The present invention forms a coating layer (hard coating film) having features such as scratch resistance, high hardness and chemical resistance on a plastic optical article such as a plastic lens. The present invention relates to a hard coating agent and a plastic optical product having the hard coating film formed on the surface thereof.

Conventional technology and problems to be solved by the invention Conventionally, in general, a coating agent is used to impart properties such as hardness, abrasion resistance, and solvent resistance to a plastic optical product that is lightweight, easily processed, and has excellent impact resistance. As a composition (Japanese Patent Publication No. 57-2735), a composition comprising a silicon compound containing an epoxy group, colloidal silica, and an aluminum chelate has been proposed. However, in this composition, since the aluminum chelate as a curing agent is added in a large amount of 5 to 10% by weight of the resin solid content, the coating film may be colored when the coating film is cured at 110 ° C. or higher. Further, there is a problem that the hardness may be lowered by boiling boiling and may be peeled from the substrate.

Further, Japanese Patent Publication No. 9266/1987 proposes a coating agent composed of an epoxy group-containing silicon compound, colloidal silica and ammonium perchlorate, which is also used as a curing catalyst when the amount of ammonium perchlorate added is resin solid. It is as high as 1 to 2% by weight relative to the mold component, and the stability of the coating liquid is poor and discoloration is large. Similarly, JP-A-53-30361 and JP-A-60-4
In JP 6502, perchloric acid or magnesium perchlorate is also used as a curing agent, but both have strong acidity, and the change with time of the coating liquid is large. Therefore, there is a drawback that silanol generated by hydrolysis of the epoxy group-containing silane is polycondensed by these catalysts to soften the cured film.

The present invention has been made in view of the above circumstances, it is possible to reduce the amount of curing catalyst, curability, good storage stability, high hardness, abrasion resistance, solvent resistance, heat resistance, adhesion An object of the present invention is to provide a hard coating agent having excellent properties and capable of forming a hard coating film that is not colored during curing, and a plastic optical product having a hard coating film formed on the surface by the hard coating agent.

Means and Actions for Solving the Problem As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that the following general formula (1) R ¹ R ² aSi (OR ³ ) _3-a (1) ( However, in the formula, R ¹ is an organic group containing an epoxy group having 2 to 8 carbon atoms, R ² is an alkyl group, an alkenyl group, a halogenated alkyl group or an aryl group having 1 to 6 carbon atoms, and R ³ is a hydrogen atom or a carbon atom. An alkyl group, an alkoxyalkyl group or an acyl group of the formula 1 to 4, and a is an integer of 0 to 2), an epoxy group-containing silicon compound or a partial hydrolyzate thereof, and an inorganic material such as silica gel, alumina sol, titania sol. For the hard coating agent containing fine particles, the following general formula (2) is used as a curing agent. (However, in the formula, R ² and R ³ represent the same groups as described above, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a halogenated alkyl group, an aryl group, an aryl group or a benzoyl group. , B, and c are each an integer of 0 to 2) and an organic peroxide or perchlorate as a curing aid (catalyst) is used in combination to produce the above compound. Curing of the epoxy group-containing silicon compound or its partial hydrolyzate can be significantly accelerated, and the catalyst amount of organic peroxides and perchlorates can be reduced, so that there is no coloring during curing. ,
The curing time can be shortened, the storage stability of the coating agent is good due to the small amount of catalyst added, and the aluminum complex compound itself has high compatibility with the organosilicon compound, and the film thickness can be increased to coat the plastic. Even if it does not cause turbidity, it is easy to dye with a disperse dye after coating a plastic lens,
The inventors have found that the obtained coating film has high hardness, excellent wear resistance, solvent resistance, and the like, and has good characteristics as a hard coating film, and thus completed the present invention.

Although the detailed reason why the hard coating agent of the present invention exhibits excellent properties is not clear, the decomposition of the aluminum complex compound of the present invention is promoted by the oxidizing property of the peroxide or perchlorate. It is considered that the generated aluminum ion promptly causes ring-opening polymerization of epoxy group and condensation of silanol, and condensation of hydroxyl group and silanol group generated by ring-opening of epoxy group. Further, since the aluminum compound of the present invention releases aluminum ions, the β-ketoester silane enters the curing system of the resin, so that the hardness can be increased with a smaller amount of catalyst than conventional aluminum acetylacetonate. I think that the.

Therefore, the present invention provides (a) an epoxy group-containing silicon compound represented by the general formula (1) or a partial hydrolyzate thereof, (b) inorganic fine particles, (c) an aluminum complex represented by the general formula (2). A hard coating agent containing a compound, (d) an organic peroxide or a perchlorate, and a plastic optical product having a hard coating film formed on the surface by the hard coating agent.

Hereinafter, the present invention will be described in more detail.

The component (a) constituting the hard coating agent of the present invention contributes to film formation and adsorption of an organic dye, and is represented by the following general formula (1) R ¹ R ² aSi (OR ³ ) _3-a (1) ( However, in the formula, R ¹ is an organic group containing an epoxy group having 2 to 8 carbon atoms, R ² is an alkyl group, an alkenyl group, a halogenated alkyl group or an aryl group having 1 to 6 carbon atoms, and R ³ is a hydrogen atom or a carbon atom. The epoxy group-containing silicon compound represented by the formula (1) to (4) is an alkyl group, an alkoxyalkyl group or an acyl group, and a is an integer of 0 to 2, or a partial hydrolyzate thereof.

Here, as R ¹ , specifically, a glycidoxypropyl group,
Epoxy cyclohexyl group and the like are mentioned, and as R ² , methyl group, ethyl group, propyl group, 3-chloropropyl group,
Examples of the 3,3,3-trifluoropropyl group, vinyl group, allyl group, phenyl group and the like, R ³ is hydrogen atom, methyl group, ethyl group, propyl group, butyl group, methoxymethyl group, methoxyethyl group. , Ethoxyethyl group, acetyl group, propionyl group and the like. In particular,
As the component (a), 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltris (methoxyethoxy) silane, 3-glycidoxypropylmethyldimethoxysilane, 3 -Glycidoxypropyl methyldiethoxysilane, 2- (3 ', 4'-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3', 4'-epoxycyclohexyl) ethyltriethoxysilane, 3-glycidoxypropyl Examples thereof include phenyldiethoxysilane, and among these, one kind or two or more kinds may be used.

The above-mentioned epoxy group-containing silicon compound can be used as it is, or can be previously hydrolyzed to use its partially hydrolyzed product. These components (a) can be dissolved in an organic solvent such as alcohols, ketones, esters, cellosolves, etc. to form a coating agent.

Further, the hard coating agent of the present invention includes trialkoxysilanes such as methyltrialkoxysilane, vinyltrialkoxysilane, phenyltrialkoxysilane, and 3-methacryloxypropyltrialkoxysilane, and
Dialkoxysilanes such as dimethyldialkoxysilane, vinylmethyldialkoxysilane, phenylmethyldialkoxysilane, diphenyldialkoxysilane, 3-methacryloxypropylmethyldialkoxysilane, methyl silicate, ethyl silicate, propyl silicate, butyl silicate, etc. The tetraalkoxysilanes, polysilicates and the like can be added to the component (a) as optional components.

Next, the hard coating agent of the present invention is constituted (b)
Inorganic fine particles as a component contribute to the film hardness of the coating agent.
It is preferable to use one selected from alumina sol and titania sol alone or in combination of two or more kinds. In this case, the particle size is preferably 1 to 200 μm, particularly 5 to 100 μm. If inorganic fine particles having a particle size smaller than 1 μm are used, the surface hardness of the coating may be poor, and if larger than 200 μm, the transparency of the coating may be deteriorated. As the above-mentioned inorganic fine particles, generally commercially available acidic solutions or basic solutions (colloid solutions dispersed in water or an organic solvent)
Can be used, specifically, Snowtex O,
Examples include methanol silica sol, alumina sol 520, titanium oxide sol NTS-10R (all manufactured by Nissan Chemical Co., Ltd.) and alumina clear sol (manufactured by Kawaken Fine Chemical Co., Ltd.).

The blending amount of the component (b) is preferably 5 to 200 parts by weight (as solid content of the inorganic fine particles), and more preferably 20 to 100 parts by weight, relative to 100 parts by weight of the component (a). (B)
If the amount of the component is less than 5 parts by weight, a coating film having high hardness cannot be obtained, and if the amount is more than 200 parts by weight, the obtained coating film may be brittle and inferior in coatability.

The component (c) of the present invention is a curing agent necessary for curing the mixture of (a) and (b), and in the present invention, the positionability of the coating agent, hardness of the coating, non-yellowing, curability, heat resistance From the viewpoint of properties, the silicon-containing aluminum complex compound represented by the following general formula (2) is used.

(However, in the formula, R ² and R ³ represent the same groups as described above, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a halogenated alkyl group, an aryl group, an acetyl group or a benzoyl group. , B and c are each an integer of 0 to 2) Specifically, as the aluminum complex compound, (However, b is an integer of 0 to 2.) One kind or two or more kinds of the compounds shown by can be used in combination.

Among these compounds Is preferably used.

These complex compounds are easily prepared by the alkoxy group exchange reaction between the β-ketoester group-containing organosilicon compound and aluminum trialkoxide described in JP-A-63-250390.

Further, the component (d) is a peroxide or a perchlorate, which acts as a co-catalyst for the component (c), specifically, benzoyl peroxide, dicumyl peroxide, t-butyl. Peroxybenzoate, di-t-butylperoxide, 1,1-bis-t-butylperoxy-3,3,
5-trimethylcyclohexane, di-t-butylperoxydiisopropylbenzoate, 2,5-dimethyl-2,5
Examples thereof include di-t-butylperoxyhexane, sodium perchlorate, potassium perchlorate, ammonium perchlorate, magnesium perchlorate, calcium perchlorate, aluminum perchlorate and indium perchlorate.

In the present invention, the aluminum complex compound as the component (c) is used in combination with the peroxide or perchlorate as the component (d), and both components (c) and (d) are used in combination. This significantly improves the curability. Therefore, the addition amount of the component (c) is preferably 0.1 to 10 relative to 100 parts by weight of the component (b).
The amount can be adjusted to 0.2 part by weight, more preferably 0.2 to 5 parts by weight, and the addition amount can be reduced to half or less by including the component (d) as compared with the conventionally used aluminum acetylacetonate. In addition, (a) component is 0.1
If it is less than 10 parts by weight, the curability of the coating agent may be poor, and if it is more than 10 parts by weight, the stability of the coating agent solution may be poor.

Further, the addition amount of the component (d) is preferably 0.01 to 1 part by weight, and more preferably 0.1 to 100 parts by weight of the component (a).
02 to 0.5 parts by weight.

The hard coating agent of the present invention may contain various components within a range that does not impair the effects of the present invention for the purpose of improving adhesion with a plastic substrate, weather resistance, coating property, antireflection property and the like. is there. For example, polyolefin-based epoxy resin, cyclohexene oxide, polyglycidyl esters, epichlorohydrin and bisphenol A
Condensation products, epoxy resins such as glycidyl methacrylate, copolymers with acrylic compounds, benzophenone series,
Examples include benzotriazole-based and phenol-based UV absorbers. For the purpose of further improving the coating property,
Various kinds of surfactants can be blended, and particularly, block copolymers or graft copolymers of dimethylsiloxane and polyether, fluorine-based surfactants, etc. are effective.

The coating agent of the present invention can be obtained by mixing the components (a) and (b), and optionally the optional components, and then adding the components (c) and (d). When a partial hydrolyzate is used, the component (a) and, if necessary, the optional components are mixed, and pure water, an acidic aqueous solution such as hydrochloric acid or acetic acid is added and hydrolyzed.
A coating agent can be obtained by adding the component (d). When the component (b) is an acidic solution or a basic solution, it is also possible to mix the component (a) and the component (b) and hydrolyze with the acidic substance or the basic substance contained in the component (b). is there.

As the solvent that can be contained in the coating agent of the present invention, lower alcohols such as methanol, ethanol, isopropanol, butanol, and isobutanol, and cellosolves such as methyl cellosolve, ethyl cellosolve, cellosolve acetate, and butyl cellosolve are preferable,
A mixture of these with a solvent such as esters, ketones and aromatic compounds is also preferably used.

The hard coating agent of the present invention is applied to various plastics and the like. Here, the plastic material to which the hard coating agent of the present invention is applied is not particularly limited, and examples thereof include polymethyl methacrylate, polycarbonate, polystyrene, polyester, diethylene glycol bisallyl carbonate (trade name: CR-39) and the like. In this case, the hard coating agent of the present invention is applied to a plastic optical product such as a plastic lens and the like and heat-treated to obtain a protective coating film having high hardness. As a coating method, a usual coating method such as brush coating, roll coating, spray coating, flow coating, dip coating and spin coating can be adopted. Further, the curing conditions vary depending on the compounding amount of the curing agent, but the temperature is lower than the softening point of the plastic substrate, usually 0.5 to 0.5 at 80 to 150 ° C.
The desired cured film can be obtained by curing for 10 hours. Further, the cured film obtained with the coating agent of the present invention can be dyed, but when dyeing, it can be arbitrarily determined by the concentration of various disperse dyes, temperature, time and the like. Generally, by soaking in a dyebath containing 0.1 to 1% by weight of dye at 80 to 100 ° C for 5 to 15 minutes,
It can be easily dyed.

EFFECTS OF THE INVENTION According to the hard coating agent of the present invention, the amount of the curing catalyst can be reduced, the storage stability is good, and the curability is also good. Further, the obtained hard coating film has high hardness, wear resistance, solvent resistance, heat resistance,
It has excellent adhesion.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Examples and comparative examples]

3-glycidoxypropyltrimethoxysilane 100g, 3
125 g of glycidoxypropylmethyldiethoxysilane and 80 g of isobutyl alcohol were poured into a flask, and 38 g of 0.05 N dilute hydrochloric acid solution was added dropwise over 30 minutes while stirring under ice cooling. Methanol silica sol (Nissan Chemical Co., Ltd.)
(Nonvolatile content 30%), and the mixture was aged at 20 to 25 ° C. for 16 hours, and then 50 g of ethanol and 70 g of ethyl cellosolve were added to prepare a coating solution (A).

To 340 parts by weight of this coating liquid (A), the aluminum compound and the peroxide or perchlorate shown in Table 1 were added, and then applied to the alkali-treated CR-39 by the dipping method,
It was cured at 120 ° C. for 60 minutes.

Next, the properties of the obtained coating film were examined by the following method. The results are shown in Table 1.

Abrasion resistance The coating was rubbed 10 times with a load of 500 g using # 0000 steel wool, and the appearance of scratches was visually determined.

Adhesion According to JIS K-5400 Clause 6.15, the cross section of the coating was cut with a knife at 1 mm intervals to cut 11 rows and 11 rows in a horizontal direction, and after applying cellophane tape (manufactured by Nichiban Co., Ltd.), a peeling test was performed. The number of squares that did not peel off was examined.

Solvent resistance The coating was lightly rubbed 100 times with absorbent cotton impregnated with acetone, and the transparency was visually evaluated.

Coloring degree The cured film was visually evaluated.

Dyeability A CR-39 lens having a coating film formed in a 0.2% by weight aqueous solution of disperse dye Brown D (manufactured by Seiko Co., Ltd.) is heated at 95 °
After immersion for 5 minutes, the light transmittance of the lens was measured.

Heat resistance 100 ° C, the appearance after 100 hours was visually evaluated.

Claims (2)

[Claims] (A) The following general formula (1) R ¹ R ² aSi (OR ³ ) _3-a (1) (wherein R ¹ is an organic group containing an epoxy group having 2 to 8 carbon atoms) , R ² is an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a halogenated alkyl group or an aryl group, R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group or an acyl group, and a is Which is an integer of 0 to 2), an epoxy group-containing silicon compound or a partial hydrolyzate thereof, (b) inorganic fine particles, and (c) the following general formula (2) (However, in the formula, R ² and R ³ represent the same groups as described above, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a halogenated alkyl group, an aryl group, an acetyl group or a benzoyl group. , B and c are each an integer of 0 to 2) and (d) an organic peroxide or a perchlorate. 2. A plastic optical product having a hard coating film formed by the hard coating agent according to claim 1 formed on the surface thereof.