JPH0684255B2 - Anti-fog coating agent for inorganic glass - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antifogging coating agent for inorganic glass, which is excellent in scratch resistance, durability and the like.

(Prior Art and Problems) Transparent inorganic glass materials are used in various fields. However, these transparent inorganic glass materials have a drawback that they become cloudy due to dew condensation when the surface temperature becomes lower than the dew point of the environment.

As a method for preventing such fogging, there are a method of putting a heat ray in the glass to keep the temperature of the glass surface above the dew point, a method of applying an antifogging agent on the glass surface, etc., but the former is extremely expensive. However, in the latter case, it is not possible to obtain a material having excellent surface scratch resistance and antifogging durability.

(Means for Solving the Problems) The inventors of the present invention have conducted intensive studies in view of such circumstances, and as a result, identified as a copolymer composed of a (meth) acrylic acid ester and a hydroxyl group-containing polymerizable unsaturated compound. Of silane coupling agent, and further an undercoating agent to which a curing catalyst is added, and a specific polyfunctional (meth) acrylate monomer to which a specific surface active group-containing phosphate ester monomer is added, Further, when a curing catalyst and a topcoat agent containing a specific trifunctional acrylic acid ester are used as required, it has excellent scratch resistance and anti-fog durability, and also has excellent transparency, adhesion and moisture resistance. It was found that an antifogging coating agent for inorganic glass, which is excellent and has excellent physical properties of the coating film such as heat cycle resistance and excellent in durability, can be obtained, and has completed the present invention.

That is, the present invention provides (A) a copolymer composed of (meth) acrylic acid ester and a hydroxyl group-containing polymerizable unsaturated compound, and (B) a general formula (I) (However, Y is a vinyl group in the formula, acryl group, a mercapto group, an amino group, R ¹ is _{-CH 2 -, - CH 2 -CH} 2 -, - CH 2 -
CH ₂ -CH ₂ - indicates, X ¹ is shows an -OCH ₃ or -OCH ₂ CH _3,
They may be the same or different. ), A silane coupling agent represented by the formula (4), and optionally (C) a curing catalyst, and (A) / (B) in a weight ratio of 90/10.
An undercoating agent having a ratio of up to 99/1, and (D) the general formula (II) [However, at least three X ² in the formula are (meth) acryloyloxy groups, the rest are hydroxyl groups, and n is an integer of 1 to 5. ] The polyfunctional (meth) acrylate monomer represented by these, and (E) General formula (III) (However, R ² in the formula represents a hydrogen atom or a methyl group, and may be the same or different, and R ³ is —CH ₂ —CH ₂ —, , Which may be the same or different. Further, m represents an integer of 1 to 50. ) A phosphoric acid ester-based monomer represented by, and optionally (F) a curing catalyst and (G) a general formula (IV) (However, 1 in the formula represents an integer of 1 to 5.) It contains a trifunctional monomer of glyceryl glycidyl ether acrylate represented by the formula (D) /
(E) / (G) is an overcoating agent having a weight ratio of 90/10/0 to 50/30/20, and an antifogging coating agent for inorganic glass is provided. If necessary, a known additive such as a solvent and a leveling agent, an ultraviolet absorber, an antioxidant and a surfactant may be added to this coating agent.

Specific examples of the copolymer (A) used as the undercoat in the present invention include (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate, and the following: Examples of the copolymer include a hydroxyl group-containing polymerizable unsaturated compound, and particularly a copolymer including methyl methacrylate and β-hydroxyethyl (meth) acrylate and / or β-hydroxypropyl (meth) acrylate. preferable.

Specific examples of the hydroxyl group-containing polymerizable unsaturated compound used in the production of the copolymer (A) include β-hydroxyethyl (meth) acrylate, β-hydroxypropyl (meth) acrylate; polyhydric alcohol and (meth) acryl. 1,6-hexanediol mono (meth) acrylate obtained by partial esterification with an acid, neopentyl glycol mono (meth) acrylate, 1,4-butanediol mono (meth) acrylate, trimethylolpropane (meth) acrylate, Pentaerythritol (meth) acrylate; and compounds obtained by addition reaction of butyl glycidyl ether, versatic acid glycidyl ester or phenyl glycidyl ether with (meth) acrylic acid.

Specific examples of the silane coupling agent (B) represented by the general formula (I) used as the undercoating agent in the present invention include vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinyl-tris (β-methoxyethoxy). ) Silane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-
Examples thereof include (aminoethyl) -γ-aminopropyltrimethoxysilane, and among them, γ-mercaptopropyltrimethoxysilane is preferable.

Specific examples of the polyfunctional (meth) acrylate monomer (D) represented by the general formula (II) used as the overcoat in the present invention include trimethylolmethane tetra (meth) acrylate and trimethylolpropane tri (meth) acrylate. Trimethylolethane tri (meth) acrylate,
Pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate Among them, trimethylolmethane tetra (meth) acrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate and dipentaerythritol hexaacrylate are preferable, and dipentaerythritol hexaacrylate is particularly preferable. is there.

What can be preferably used as the phosphoric acid ester-based monomer (E) represented by the general formula (III) used in the overcoating agent in the present invention, R ^{2 in} the formula is a hydrogen atom or a methyl group, and R ³ is —CH.
₂ -CH ₂ - or And a compound in which m is an integer of 10 to 25, and particularly preferred are those in which R ² is a methyl group and R ³ is A compound in which m is 20.

The antifogging coating composition of the present invention comprising an undercoating agent and a topcoating agent containing the above (A) to (C) and (D) to (F) as main components has an antifogging property which is sufficiently excellent in durability as it is. However, when particularly excellent antifogging durability is required, by further adding a trifunctional monomer (G) of an acrylate ester of glyceryl glycidyl ether represented by the general formula (IV), , Which can synergistically improve the antifogging durability. Among them, particularly preferable one is 1 in the formula.

The proportion of (A) and (B) used in the undercoating agent is usually 90 to 9 for (A), with the total amount of (A) and (B) being 100% by weight.
9% by weight and 10 to 1% by weight of (B) are preferable, and 92 to 95% by weight of (A) and 8 to 5% by weight of (B) are preferable. If the proportion of (A) used is less than 90% by weight, the antifogging property will decrease, and if it exceeds 99% by weight, the adhesion to the inorganic glass will decrease, which is not preferable.

The proportion of (D), (E), and (G) used in the topcoat is
With the total amount of (D), (E) and (G) being 100% by weight,
Usually (D) is 50 to 90% by weight, (E) is 30 to 10% by weight,
(G) is 0 to 20% by weight, but when (G) is not used, (D) is preferably 70 to 80% by weight and (E) is preferably 30 to 20% by weight. When using (D)
55-70 wt%, (E) 35-15 wt%, (G) 10-15
Weight% is especially preferable. The usage ratio of (D) is 50
If it is less than 10% by weight, the scratch resistance is lowered, and if it exceeds 90% by weight, the antifogging property is lowered. Also,
If the proportion of (E) used is less than 10% by weight, the antifogging property will decrease,
If it exceeds 30% by weight, the scratch resistance and the adhesion with the undercoating agent are deteriorated, which are not preferable.

Examples of the solvent used in the present invention for the undercoating agent include aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone. Examples thereof include alcohols such as methanol, ethanol, N-butyl alcohol and isopropyl alcohol; aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and methyl ethyl isobutyl ketone; ethyl acetate, butyl acetate and methyl cellosolve. acetate,
Examples thereof include esters such as ethyl cellosolve acetate. The solvent used for the undercoating agent or the overcoating agent may be used alone or as a mixture of two or more kinds.

By coating the anti-fog coating agent of the present invention on an inorganic glass molded article,
Irradiation with ultraviolet rays, electron beams or radiation is required to form a crosslinked cured film. Among them, the curing method by ultraviolet irradiation is particularly preferable from the practical viewpoint.
It is necessary to add a curing catalyst, which generates radicals upon irradiation with ultraviolet rays, to the undercoating agent and the overcoating agent.

Specific examples of the curing catalyst (C) or (F) include benzophenone, p-chlorobenzophenone, 4,4'-bis (diethylamino) benzophenone, benzoin, benzoin ethyl ether, acetophenone, 2-chlorothioxanthone, 2-ethyl. Examples thereof include abstraction type and cleavage type carbonyl compounds such as anthraquinone, 2-aminoanthraquinone, 2-chloroanthraquinone and α-hydroxyisobutylphenone, and sulfur compounds such as tetramethylthiuram and disulfide. These curing catalysts may be used alone or in combination of two or more.

The amount of these curing catalysts used is based on 100 parts by weight of the resin solid content of the undercoating agent comprising (A) and (B), and (D).
0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight per 100 parts by weight of the resin solid content of the overcoating agent consisting of (E) and (G).
The range is parts by weight. When the amount used exceeds 5 parts by weight, the moisture resistance and weather resistance of the coating film are deteriorated and the coating film is discolored, which is not preferable.

The inorganic glass molded article in which the antifogging coating agent of the present invention is used may be one produced from inorganic glass,
Examples include various window glasses, instrument covers, mirrors and the like.

For coating various inorganic glass molded articles with the antifogging coating agent of the present invention, for example, after coating an undercoating agent, at least curing is performed to such an extent that the coating of the overcoating agent is possible, and then the overcoating agent is coated and completely cured. Just do it.

The coating method includes, for example, spray coating, dip coating, roll coater coating, flow coater coating, spin coater coating, etc., and may be appropriately selected according to the shape of the article to be coated.

The coating thickness is 1 to 20 μm for the undercoat and 1 to 10 for the topcoat.
μm is suitable, but from the viewpoints of adhesion, scratch resistance, antifogging and durability, it is preferable that the undercoating agent is 10 to 15 μm and the topcoating agent is 3 to 7 μm.

(Effects of the Invention) A coating film obtained from the antifogging coating agent for inorganic glass of the present invention has excellent scratch resistance and antifogging durability, and is also excellent in transparency, adhesion and moisture resistance. In addition, the coating film has good physical properties such as heat cycle resistance, and is extremely durable.

(Example) Hereinafter, the present invention will be specifically described with reference to Examples, Examples and Comparative Examples. All parts in the examples are parts by weight.

Reference Example 1 [Production of Copolymer (A) Comprising (Meth) acrylic Acid Ester and Hydroxyl Group-Containing Polymerizable Unsaturated Compound] In a four-necked flask equipped with a condenser and a stirrer, 95 parts of methyl methacrylate, β-hydroxyl Charge 5 parts of ethyl methacrylate and 0.6 parts of n-dodecyl mercaptan,
The reaction was carried out at 95 ° C under a nitrogen stream for 8 hours, and when the viscosity was 8 poise, 50 ppm of a polymerization inhibitor hydroquinone was added and cooled to obtain an acrylic copolymer (A-1).

Reference Example 2 (same as above) Reference Example 1 except that β-hydroxypropyl acrylate was used instead of β-hydroxyethyl methacrylate.
An acrylic copolymer (A-2) was obtained in the same manner as.

Examples 1 to 5 and Comparative Examples 1 to 5 Each raw material was blended with the undercoating agent composition and the overcoating agent composition shown in Table 1 to prepare antifogging coating agents of the present invention and comparative controls.

Next, the undercoating agent was applied to the inorganic glass plate with a bar coater, dried at 80 ° C. for 5 minutes, and then irradiated with UV light for 7 seconds with a 80 W / cm high-pressure mercury lamp (Nippon Battery Co., Ltd.), and then the overcoating agent was applied with a bar coater. After coating and drying at 80 ℃ for 5 minutes, irradiate with UV light for 10 seconds by 80W / cm high pressure mercury lamp,
An inorganic glass plate having a cured coating film was obtained, and the performance was evaluated by the following tests. The results are shown in Table-2.

(1) Adhesion test: Make a cut that reaches the synthetic resin of the base from the painted surface so that 100 squares of 1.5 mm square can be made, make sure that the cellophane tape is sufficiently adhered to it, then peel off this cellophane tape vigorously Then, the remaining number of squares is counted and the denominator is expressed as 100.

(2) Coating film hardness test: According to JIS K-5400, the pencil hardness with a load of 1 kg is measured.

(3) Scratch resistance test: strongly scratch the coated surface with a claw,
The scratches were visually evaluated by the following four grades.

A: No scratches are recognized.

○: Some scratches are observed.

Δ: A scratch is recognized.

X: Remarkably scratched.

(4) Antifogging test: After leaving the sample in a constant temperature and humidity chamber at a temperature of 10 ° C and a relative humidity of 65% RH for 10 minutes, 0.5 to 1.0 from the coated surface
Exhalation was blown from a distance of cm, and the cloudiness was evaluated with the naked eye by the following four grades.

A: No cloudiness is observed.

○: Some cloudiness is observed.

Δ: Fogging is observed.

X: Remarkably cloudy is observed.

(5) Moisture resistance test: After the sample was left in a constant temperature and humidity chamber at 70 ° C. and a relative humidity of 100% RH for 300 hours and 500 hours, the adhesion, coating hardness, and antifogging property were measured in the same manner as above. .

(6) Heat cycle resistance test: Using a heat cycle testing machine (program constant temperature and humidity chamber GLP-44 manufactured by Irie Seisakusho Co., Ltd.), 70 ° C × 20% RH × 3 hours → 23 ° C × 75% RH × 1 hour → −
30 ℃ × 3 hours → 23 ℃ × 75% RH × 1hour → 70 ℃ × 95% RH ×
This cycle was repeated 6 times with 15 hours → 23 ° C. × 75% RH × 1 hour as one cycle, and then the adhesion, coating hardness and antifogging property were measured in the same manner as above.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location // B05D 5/06 Z 8720-4D 7/00 E 8720-4D C08F 220/12 MME 7242-4J 220/20 MMV 7242-4J 230/02 MNS 7242-4J 230/08 MNU 7242-4J

Claims (1)

[Claims] 1. A copolymer comprising (A) a (meth) acrylic acid ester and a hydroxyl group-containing polymerizable unsaturated compound, and (B) a general formula (I). (However, Y is a vinyl group in the formula, acryl group, a mercapto group, an amino group, R ¹ is _{-CH 2 -, - CH 2 -CH} 2 -, - CH 2 -
CH ₂ -CH ₂ - indicates, X ¹ is shows an -OCH ₃ or -OCH ₂ CH _3,
They may be the same or different. ), A silane coupling agent represented by the formula (4), and optionally (C) a curing catalyst, and (A) / (B) in a weight ratio of 90/10.
An undercoating agent having a ratio of up to 99/1, and (D) the general formula (II) [However, at least three X ² in the formula are (meth) acryloyloxy groups, the rest are hydroxyl groups, and n is an integer of 1 to 5. ] The polyfunctional (meth) acrylate monomer represented by these, and (E) General formula (III) (However, R ² in the formula represents a hydrogen atom or a methyl group, and may be the same or different, and R ³ is —CH ₂ —CH ₂ —, , Which may be the same or different. Further, m represents an integer of 1 to 50. ) A phosphoric acid ester-based monomer represented by, and optionally (F) a curing catalyst and (G) a general formula (IV) (In the formula, 1 represents an integer of 1 to 5.) A triglyceride glycidyl ether acrylate trifunctional monomer represented by the formula (1) and (D) / (E) / (G) Is an overcoating agent having a weight ratio of 90/10/0 to 50/30/20, and is an antifogging coating agent for inorganic glass.