JPH07117601B2 - 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 an epoxy group-containing silicon compound, 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 the 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, can be low temperature curing with an appropriate amount of curing catalyst, curability, good storage stability, high hardness, abrasion resistance, solvent resistance, An object of the present invention is to provide a hard coating agent having excellent adhesion and dyeability and capable of forming a hard coating film which is not colored during curing, and a plastic optical product having the hard coating film formed on the surface by the hard coating agent. .

Means and Actions for Solving the Problems 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 _a Si (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, an alkenyl group, a halogenated alkyl group or an aryl group, and R ³ is a hydrogen atom, an alkyl group or an alkoxyalkyl group. Alternatively, it is an acyl group, and a is 0 to
It is an integer of 2. ) An epoxy group-containing silicon compound represented by or a partial hydrolyzate thereof, silica sol, alumina sol, titania sol,
For a hard coating agent containing inorganic fine particles such as antimony oxide sol, the following general formula (2) M (SbX ₆ ) _b (2) (wherein M is a positively charged atom or ammonium group,
X is a halogen atom, and b is the valence of M. By compounding the antimony compound represented by the formula (1), the curing of the epoxy group-containing silicon compound or the partial hydrolyzate thereof can be significantly promoted, and the curing catalyst amount can be reduced. It was found that there is no coloration and the storage stability of the coating agent is good. Further, the above-mentioned antimony compound and a curing co-catalyst thereof are represented by the following general formula (3) AlY ₃ (3) (where Y is a halogen atom, a hydroxyl group, and a carbon number of 1 to 4)
Is an alkoxy group, an acyloxy group, a benzoyloxy group or a perchloric acid group. ) It is possible to shorten the curing time or lower the curing temperature by blending together with the aluminum compound represented by, and it is easy to dye with a disperse dye after coating the plastic lens, It has been found that the obtained coating film has high hardness, excellent wear resistance, solvent resistance and the like, and has good properties as a hard coating film. In this case, the antimony compound is NaSbF ₆ , and the aluminum compound is AlCl ₃ .6H ₂
By using O and using both of them together, the curing time can be shortened and the curing temperature can be lowered. From this point as well, coloring at the time of curing can be prevented, and coating on a plastic lens is also possible. Later, they discovered that dyeing with a disperse dye was easy, and completed the present invention.

Therefore, the present invention provides the following general formula (2) such as (a) the epoxy group-containing silicon compound represented by the general formula (1) or a partial hydrolyzate thereof, (b) inorganic fine particles, (c) NaSbF _{6 and the} like. A hard coating agent containing an antimony compound shown below, (d) an aluminum compound shown by the above general formula (3) such as AlCl ₃ .6H ₂ O, and a hard coating film formed by the hard coating agent on the surface. To provide plastic optical products.

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 organic dye, and is represented by the following general formula (1) R ¹ R ² _a Si (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, an alkenyl group, a halogenated alkyl group or an aryl group, and R ³ is a hydrogen atom, an alkyl group or an alkoxyalkyl group. Alternatively, it is an acyl group, and a is 0 to
It is an integer of 2, preferably 0 or 1. ) An epoxy group-containing silicon compound represented by or a partial hydrolyzate thereof is used.

Specific examples of R ¹ include a glycidoxyalkyl group having an alkyl group having 1 to 4 carbon atoms such as a glycidoxymethyl group and a glycidoxypropyl group, and an epoxycycloalkyl group. The alkyl group and halogenated alkyl group for R ² preferably have 1 to 6 carbon atoms, the alkenyl group preferably has 2 to 6 carbon atoms, and the aryl group preferably has 6 to 10 carbon atoms. Specifically, as R ² , methyl group, ethyl group, propyl group, 3-
Examples include chloropropyl group, 3,3,3-trifluoropropyl group, vinyl group, allyl group and phenyl group. Preferably has 1 to 4 carbon atoms as the alkyl group of R ^3, preferably having a carbon number of 2-8, especially 3-8 comprising alkoxy of 1 to 4 carbon atoms as an alkoxyalkyl group, particularly a R ³ Specifically, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a methoxyethyl group, an ethoxyethyl group, an acetyl group, a propionyl group and the like are shown. Specifically, as the component (a), 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltris (methoxyethoxy) silane, 3-glycidoxypropyl Methyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3 ', 4'-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3', 4'-epoxycyclohexyl) ethyltriethoxysilane, 3 -Glycidoxypropyl phenyldiethoxysilane etc. can be illustrated, and 1 type (s) or 2 or more types can be used among these.

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 usually dissolved in an organic solvent such as alcohols, ketones, esters, cellosolves and aromatic compounds 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)
The inorganic fine particles as a component contribute to the film hardness of the coating agent, and the inorganic fine particles include silica sol,
It is preferable to use one selected from antimony oxide sol, alumina sol and titania sol, particularly neutral or basic one, or to use two or more kinds in combination. in this case,
The particle size is preferably 1 to 200 mμ, particularly 5 to 100 mμ. If inorganic fine particles having a particle size smaller than 1 mμ are used, the surface hardness of the coating may be poor, and if larger than 200 mμ, the transparency of the coating may be deteriorated. As the above-mentioned inorganic fine particles, generally commercially available acidic solutions, neutral solutions, and basic solutions (colloidal solutions dispersed in water or an organic solvent) can be used. Specifically, Snowtex O, Snowtex C, Snowtex N, methanol silica sol, alumina sol 520, titanium oxide sol NTS-10R, DMF sol, Sun colloid (all manufactured by Nissan Chemical Co., Ltd.), alumina clear sol (manufactured by Kawaken Fine Chemicals Co., Ltd.),
Cataloid S (manufactured by Catalysts & Chemicals Co., Ltd.) and the like are exemplified. In addition, commercially available acidic colloidal inorganic fine particles are added to ammonia,
Neutralized or basic colloids neutralized with basic substances such as amines and metal hydroxides can also be preferably used.

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 coverage.

The component (c) of the present invention is a curing catalyst necessary for curing the mixture of (a) and (b), and in the present invention, the stability of the coating agent, the hardness of the coating, the non-yellowing property, the curability, etc. From the point, the antimony compound represented by the following general formula (2) is used.

M (SbX ₆ ) _b (2) Here, M in the formula is a positively charged atom or an ammonium group, for example, hydrogen, lithium, sodium, potassium,
Magnesium, calcium, aluminum, ammonium and the like can be mentioned, X is a halogen atom such as fluorine, chlorine, bromine and iodine, and b is the valence of M.

Specifically, such antimony compounds include lithium hexafluoroantimonate, sodium hexafluoroantimonate, potassium hexafluoroantimonate, ammonium hexafluoroantimonate, magnesium hexafluoroantimonate, aluminum hexafluoroantimonate, and lithium hexachloroantimonate. , Sodium hexachloroantimonate, etc. can be used alone or in combination of two or more.
Among these, those selected from lithium hexafluoroantimonate, sodium hexafluoroantimonate, potassium hexafluoroantimonate, ammonium hexafluoroantimonate, magnesium hexafluoroantimonate, and aluminum hexafluoroantimonate are preferably used.

The addition amount of the component (c) can be preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the component (b), as compared with the conventionally used aluminum acetylacetonate. The amount of addition can be reduced to half or less. If the amount of component (C) added is less than 0.1 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 solution may be poor.

Further, in the present invention, together with the antimony compound of the above (C) component, as the (D) component, the following general formula (3) AlY ₃ (3) (where Y is a halogen atom, a hydroxyl group, a carbon number of 1 to 4)
Is an alkoxy group, an acyloxy group, a benzoyloxy group or a perchloric acid group. It is preferable to add the aluminum compound represented by the formula (4) to the extent that the stability of the coating agent solution is not impaired. This aluminum compound acts as a co-catalyst for the above-mentioned component (c), and by adding it, the curing time of the coating agent can be shortened or the curing temperature can be lowered.

Specific examples of the aluminum compound represented by the formula (3) include aluminum chloride, hydroxy aluminum chloride, aluminum triethoxide, aluminum tripropoxide,
Examples include aluminum isopropoxide, aluminum tributoxide, aluminum triisobutoxide, aluminum acetate, aluminum propionate, aluminum benzoate, aluminum trisacetylacetonate, aluminum salicylate, aluminum lactate, and aluminum perchlorate.

Furthermore, the addition amount of the component (d) is preferably 5 parts by weight or less, particularly 3 parts by weight or less, relative to 100 parts by weight of the component (a). If the addition amount is more than 5 parts by weight, the coating agent solution Stability may deteriorate. From the viewpoint of exerting the function of the component (d), the component (d) is 0.01 parts by weight or more,
Particularly, it is preferable to add 0.05 parts by weight or more.

Among the above-mentioned components (c) and (d), in particular, the curing time of the coating agent is shortened or the curing temperature is lowered, and from the point of dyeability, AlCl ₃ .6H ₂ O and NaSbF ₆ are used in combination. Recommended to use.

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 component (a) and the component (b), and optionally the optional component, and then adding the component (c) and, if necessary, the component (d), In particular, when the partial hydrolyzate is used as the organosilicon compound, the component (a) and, if necessary, optional components are mixed, and pure water, an acidic aqueous solution such as hydrochloric acid or acetic acid is added and hydrolyzed. , (C) component, and if necessary, (D) component can be added to obtain a coating agent. 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.

Solvents that can be contained in the coating agent of the present invention include lower alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, and diacetone alcohol, and cellosolves such as methyl cellosolve, ethyl cellosolve, cellosolve acetate, and butyl cellosolve. Are preferred, and esters, ketones,
A mixture of solvents such as amides 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, but polymethyl methacrylate, polycarbonate, polystyrene, polyester, polyurethane, polythiourethane, diethylene glycol bisallyl carbonate (trade name: CR-39). Etc. 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 catalyst, but the temperature below the softening point of the plastic substrate, usually at 80 to 150 ° C. for 0.5 to 10 hours, to obtain the target cured film. it can. 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, 80% in a dye bath in which 0.1 to 1% by weight of dye is dispersed.
It can be easily dyed by immersing at -100 ° C for 5-15 minutes.

EFFECTS OF THE INVENTION According to the hard coating agent of the present invention, the curing temperature can be lowered, the coloring is small, and the storage stability is good. The obtained hard coating film has high hardness and is excellent in wear resistance, solvent resistance and adhesion.

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

[Examples 1 and 2, Comparative Examples 1 to 6] 3-glycidoxypropyltrimethoxysilane 100 g, 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 water was added dropwise over 30 minutes while stirring under ice cooling. Then, add 300 g of colloidal silica / methanol solution (Nissan Chemical Co., Ltd., nonvolatile content 30%, pH8),
After aging at 25 ° C. for 16 hours, 50 g of ethanol and 70 g of ethyl cellosolve were added to prepare a coating solution.

[Examples 3 and 4] In the above Examples, 300 g of methanol silica sol was replaced with a solution of antimony oxide sol in methanol (non-volatile content 30
%, PH 7) 100 g and a colloidal silica dimethylformamide solution (nonvolatile matter 20%, pH 8) 300 g were used in the same manner except that a mixture was prepared.

Next, after adding the curing catalyst shown in Table 1 to 100 parts by weight of the above coating liquid, it was applied to CR-39 subjected to alkali treatment by a dipping method and cured at 100 ° C. or 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.) was used at 87 ° C.
After immersion for 5 minutes, the light transmittance of the lens was measured.

Staining property with time The coating agent was stored at 20 ° C for 1 month.
The above dyeability test was conducted on the coating film applied and cured on the lens.

From the results shown in Table 1, the hard coating agent containing the antimony compound represented by the above formula (2) as a curing catalyst is hardened at a lower temperature than the one using a curing catalyst such as aluminum acetonate, and has a good wear resistance and It was confirmed that the hard coating film was excellent in solvent property and adhesiveness and had good dyeability. In addition, it was confirmed that discoloration and changes with time were small by using NaSbF ₆ and AlCl ₃ .6H ₂ O together.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Kenji Yamamoto Kenji Yamamoto 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory (72) Inventor Shigeru Mori Gunma Prefecture Annaka 2-13-1, Isobe, Ichi, Japan Shin-Etsu Chemical Co., Ltd. Silicon Silicon Electronic Materials Research Laboratory (56) References Japanese Patent Publication No. 55-39562 (JP, B2) Japanese Publication No. 62-9266 (JP, B2)

Claims (3)

[Claims] (A) The following general formula (1) R ¹ R ² _a Si (OR ³ ) _3-a (1) (wherein R ¹ is an organic group containing an epoxy group having 2 to 8 carbon atoms) A group, R ² is an alkyl group, an alkenyl group, a halogenated alkyl group or an aryl group, R ³ is a hydrogen atom or an alkyl group, an alkoxyalkyl group or an acyl group, and a is 0 to
It is an integer of 2. ) An epoxy group-containing silicon compound represented by or a partial hydrolyzate thereof, (b) inorganic fine particles, and (c) the following general formula (2) M (SbX ₆ ) _b (2) (where M in the formula is Positively charged atom or ammonium group,
X is a halogen atom, and b is the valence of M. And (d) the following general formula (3) AlY ₃ (3) (wherein Y is a halogen atom, a hydroxyl group, and a carbon number of 1 to 4)
Represents an alkoxy group, an acyloxy group, a benzoyloxy group or a perchloric acid group. ) An aluminum compound represented by 2. Na as the antimony compound of the general formula (2)
The hard coating agent according to claim 1, wherein SbF ₆ is used and AlCl ₃ .6H ₂ O is used as the aluminum compound of the general formula (3). 3. A plastic optical product comprising a hard coating film formed by the hard coating agent according to claim 1 or 2 on the surface.