JP2600231B2 - Anti-fog coating for inorganic glass - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an antifogging coating agent for inorganic glass having excellent durability such as scratch resistance and boiling water resistance.

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

As a method for preventing such fogging, there is a method of putting a heat ray in glass and keeping the temperature of the glass surface at a dew point or higher, a method of applying an antifogging agent to the glass surface, and the like, but the former is extremely expensive. Under the current situation, the latter cannot provide excellent surface scratch resistance and antifogging durability.

For this reason, the applicant has already applied for a composition which has improved these disadvantages (Japanese Patent Application No. 61-94638). That is,
This improved antifogging composition is obtained by adding a specific silane coupling agent to a copolymer composed of a (meth) acrylic ester and a hydroxyl group-containing polyunsaturated compound, and further adding a curing catalyst as needed. Finishing agent, a specific phosphoric ester monomer added to a specific polyfunctional (meth) acrylate monomer, and, if necessary, a curing catalyst and a specific trifunctional acrylate monomer. It has excellent scratch resistance and anti-fogging durability, and is excellent in transparency, adhesion, moisture resistance, and coating film properties such as heat cycle resistance. It has the advantage of being superior.

However, even though this composition is excellent in durability, it is insufficient in adhesion and durability of coating film hardness in applications requiring severe conditions such as boiling water immersion.

(Means for Solving the Problems) In view of such circumstances, the present inventors have conducted intensive studies and as a result, have identified a copolymer comprising a (meth) acrylic ester and a hydroxyl group-containing polymerizable unsaturated compound. Silane coupling agents and specific dicyclopentenyloxy (alkyl)
(Meth) acrylate is added, and if necessary, a primer is further added with a curing catalyst, and a specific polyfunctional (meth) acrylate monomer is added with a specific surfactant-containing phosphoric acid ester-based monomer. If necessary, a curing catalyst and a topcoat containing a specific trifunctional acrylate monomer are used to provide excellent scratch resistance and antifogging durability, as well as transparency, adhesion, and moisture resistance. The present inventors have found that an antifogging coating agent for inorganic glass having excellent coating properties such as excellent water resistance, boiling water resistance and heat cycle resistance and excellent durability can be obtained, thereby completing the present invention.

That is, the present invention provides (A) a copolymer comprising a (meth) acrylate and a hydroxyl group-containing polymerizable unsaturated compound, (B) a general formula (I) (Where Y is a vinyl group, an acryl group, a mercapto group, an amino group, and R ¹ is —CH ₂ —, —CH ₂ —CH ₂ —, —CH ₂ —
X ₂ represents CH ₂ —CH ₂ — and X ¹ represents —OCH ₃ — or —OCH ₂ CH _3, which may be the same or different. A silane coupling agent represented by the formula: and (C) a general formula (II) (Wherein, R ² in the formula represents a hydrogen atom or a methyl group, R ³
Is _{-O -, - CH 2 O -} , - CH 2 CH 2 O-, Is shown. ) Dicyclopentenyloxy (alkyl) represented by
(Meth) acrylate monomer, and if necessary, (D) a curing catalyst, and (A) / (B) / (C) are in a weight ratio of 40/10/50 to 94/1 / And (E) a general formula (III) [However, in the formula, at least three of X ² are (meth) acryloyloxy groups, the rest are hydroxyl groups, and n is an integer of 1 to 5. A polyfunctional (meth) acrylate monomer represented by the formula: and (F) a general formula (IV) (However, R ⁴ in the formula represents a hydrogen atom or a methyl group, and may be the same or different, and R ⁵ represents —CH ₂ —CH ₂ —, And each may be the same or different. M represents an integer of 1 to 50. A) a phosphoric acid ester monomer represented by the formula (V), and further, if necessary, a (G) curing catalyst and (H) a general formula (V) (However, 1 in the formula represents an integer of 1 to 5.) A trifunctional monomer of glyceryl glycidyl ether acrylate represented by the following formula (E) / (F) / (H) Is an overcoating agent having a weight ratio of 90/10/10 to 10/30/60.

Incidentally, a solvent and a known additive such as a leveling agent, an ultraviolet absorber, an antioxidant, a surfactant and the like can be further added to the coating agent, if necessary.

Specific examples of the copolymer (A) used for the undercoating agent in the present invention include (meth) acrylic esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate; Copolymers comprising such a hydroxyl group-containing polymerizable unsaturated compound, and particularly copolymers comprising methyl methacrylate and β-hydroxyethyl (meth) acrylate and / or β-hydroxypropyl (meth) acrylate. preferable.

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

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

As the dicyclopentenyloxy (alkyl) (meth) acrylate monomer (C) represented by the general formula (II) used for the undercoating agent in the present invention, any one represented by the general formula (II) can be preferably used. However, a compound in which R ² in the general formula (II) is a hydrogen atom and R ³ is —CH ₂ CH ₂ O— is particularly preferable.

Specific examples of the polyfunctional (meth) acrylate monomer (E) represented by the general formula (III) used for the overcoating agent in the present invention include trimethylolmethanetetra (meth) acrylate and trimethylolpropanetri (meth) acrylate , Trimethylolethanetri (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, preferred are trimethylolmethanetetra (meth) acrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate, and particularly preferred is dipentaerythritol hexaacrylate. .

Which can be preferably used as phosphoric acid ester monomer represented by the general formula (IV) used in the topcoat in the present invention (F) is, R ⁴ is a hydrogen atom or a methyl group in the general formula (IV), R ⁴ Is -CH ₂ -CH ₂ -or Wherein m is an integer of 10 to 25, and particularly preferred are those in which R ⁴ is a methyl group and R ⁵ is m is 20.

The antifogging coating composition of the present invention, which comprises an undercoating agent and an overcoating agent containing the above (A) to (D) and (E) to (G) as main components, has an antifogging property having sufficiently excellent durability as it is. Has, but when further excellent antifogging durability is required,
By further adding a trifunctional monomer (H) of an acrylic acid ester of glyceryl glycidyl ether represented by the general formula (V), the antifogging durability can be synergistically improved. Particularly preferred are those in which 1 in the formula is 1.

The usage ratio of (A) / (B) / (C) in the primer is as follows:
Assuming that the total amount of (A), (B) and (C) is 100% by weight,
Usually (A) is 40 to 94% by weight, (B) is 1 to 10% by weight,
(C) is 5 to 50% by weight.
82% by weight, (B) 3 to 8% by weight, and (C) 15 to 25% by weight are preferred. When the use ratio of (A) is less than 40% by weight, the anti-fogging property is reduced, and when it exceeds 94% by weight, the adhesion of boiling water to the inorganic glass is reduced.
If the proportion of (B) is less than 1% by weight, the initial adhesion to the inorganic glass decreases, and if it exceeds 10% by weight, the storage stability of the coating agent decreases, which is not preferable. Furthermore,
If the use ratio of (C) is less than 5% by weight, the adhesion to boiling water with inorganic glass is reduced, and if it exceeds 50% by weight, the initial adhesion to inorganic glass is reduced, and thus it is not preferable.

The proportion of (E), (F) and (G) in the topcoat is
Assuming that the total amount of (E), (F) and (H) is 100% by weight,
Usually (E) is 10 to 90% by weight, (F) is 10 to 30% by weight,
(H) is 0 to 60% by weight, but when (H) is not used, it is particularly preferable that (E) is 70 to 80% by weight and (F) is 30 to 20% by weight. If you use (E)
20-45% by weight, (F) 13-25% by weight, (H) 42-55
% Is especially preferred. In addition, the use ratio of (E) is 10
If the amount is less than 90% by weight, the abrasion resistance is reduced. If the amount is more than 90% by weight, the antifogging property is reduced. Also,
When the use ratio of (F) is less than 10% by weight, the anti-fogging property decreases,
If it exceeds 30% by weight, the abrasion resistance and the adhesion to the undercoating agent are reduced, so that each is not preferred.

The solvent used as necessary in the present invention includes, for the undercoating agent, for example, aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone; and for the overcoating agent. 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;
Esters such as ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate and the like can be mentioned. One of these solvents used for the undercoating agent or the overcoating agent may be used alone, or two or more of them may be used in combination.

In order to apply the antifogging coating agent of the present invention to an inorganic glass molded article to form a crosslinked cured film, irradiation with ultraviolet rays, electron beams or radiation is required. Above all, a curing method by ultraviolet irradiation is particularly preferable from a practical point of view. In this case, it is necessary to add a curing catalyst that generates radicals by irradiation with ultraviolet light to the undercoating agent and the overcoating agent.

Specific examples of the curing catalyst (D) or (G) include benzophenone, p-chlorobenzophenone, 4,4'-bis (diethylamino) benzophenone, benzoin, benzoin ethyl ether, acetophenone, 2-chlorothioxanthone, 2-ethyl Examples include pull-out and cleavage 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 amounts of these curing catalysts used are (A), (B) and (C)
0.1 to 5 parts by weight, preferably 100 parts by weight of the resin solid content of the undercoating agent composed of: and 100 parts by weight of the resin solid content of the overcoating agent composed of (E), (F) and (H) Ranges from 0.5 to 3 parts by weight. If the amount exceeds 5 parts by weight, the moisture resistance and weather resistance of the coating film are reduced, and the coating film is discolored.

The inorganic glass molded article to which the antifogging coating agent of the present invention is used is not particularly limited as long as it is produced from inorganic glass, and examples thereof include various window glasses, instrument covers, and mirrors.

The coating of the antifogging coating agent of the present invention on various inorganic glass molded articles is, for example, after applying a primer, curing at least to the extent that the coating of the topcoat is possible, then coating the topcoat, and completely curing. Just do it.

As a coating method, for example, spray coating, dip coating,
There are roll coater coating, flow coater coating, spin coater coating, and the like, which may be appropriately selected according to the shape of the object to be coated.

The coating thickness is 1 to 20 μm for the undercoat, 1 to
10 μm is suitable, but among these, from the viewpoints of adhesion, scratch resistance, antifogging property and durability, the undercoating agent is preferably 10 to 15 μm, and the overcoating agent is preferably 3 to 7 μm.

(Examples) Hereinafter, the present invention will be specifically described with reference 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-hydroxy 5 parts of ethyl methacrylate and 0.6 part of n-dodecyl mercaptan were charged and reacted at 95 ° C. for 8 hours under a nitrogen stream. When the viscosity was 8 poise, 50 ppm of a polymerization inhibitor hydroquinone was added.
After cooling, an acrylic copolymer (A-1) was obtained.

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

Examples 1 to 5 and Comparative Examples 1 to 5 Each raw material was blended with the undercoat composition and the overcoat composition shown in Table 1 to prepare antifogging paints of the present invention and comparative controls.

Then, an undercoat was applied to the inorganic glass plate with a bar coater, dried at 80 ° C. for 5 minutes, irradiated with ultraviolet light for 7 seconds using an 80 W / cm high-pressure mercury lamp (manufactured by Nippon Battery Co., Ltd.), and then the overcoat was applied with a bar coater. After coating and drying at 80 ° C. for 5 minutes, an ultraviolet ray was irradiated for 10 seconds with an 80 W / cm high-pressure mercury lamp to obtain an inorganic glass plate having a cured coating film, and the performance was evaluated by the following tests. Table 2 shows the results.

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

(2) Coating film hardness test: Measure the pencil hardness under a load of 1 kg in accordance with JIS K-5400.

(3) Scratch resistance test: The painted surface was strongly scratched with claws.
The contact of the wound was visually evaluated in the following four stages.

A: No scratch is observed.

…: Some scratches are observed.

Δ: Scratches are observed.

×: remarkable scratches are observed.

(4) Anti-fog test: After leaving the sample in a thermo-hygrostat at a temperature of 10 ° C and a relative humidity of 65% RH for 10 minutes, 0.5 to 1.0 from the painted surface
Expiration was blown from a distance of cm, and the degree of cloudiness was visually evaluated by the following four steps.

A: No fogging is observed.

…: Some clouding is observed.

Δ: Clouding is observed.

X: remarkably cloudy.

(5) Moisture resistance test: After leaving the sample in a thermo-hygrostat at 70 ° C. and a relative humidity of 100% RH for 300 hours and 500 hours, adhesion, coating film hardness and anti-fogging property were measured in the same manner as above. .

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

(7) Boiling water adhesion test: Using a water path, 98-
Place the sample vertically in a boiling water bath at 100 ° C. and boil for 4 hours. Then, after leaving at room temperature for 2 hours, the adhesion and the coating film hardness were measured in the same manner as above.

* 1) UV7000B: GO-SELLAC UV7000B [Urethane acrylic monomer manufactured by Nippon Synthetic Chemical Co., Ltd.] * 2) FA-512A: Hitaloid FA-512A [Dicyclopentenyloxy manufactured by Hitachi Chemical Co., Ltd.]
Ethyl acrylate] * 3) FA-511A: Hitaloid FA-511A [Dicyclopentenyloxy- manufactured by Hitachi Chemical Co., Ltd.]
Acrylate] * 4) DPHA: Pentadierythritol hexaarylate [Nippon Kayaku Co., Ltd.] * 5) A-TMMT: Trimethylolmethanetetraacrylate [Shin-Nakamura Chemical Co., Ltd.] * 6) PTA: Pentaerythritol tetra Acrylate [manufactured by Shin-Nakamura Chemical Co., Ltd.] * 7) 229E: New Frontier A-229E [a phosphate ester monomer manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. wherein R ⁴ is a methyl group in the general formula (IV); R ⁵ Compound with m = 20] * 8) DA-314: Denacool acrylate DA-314 [a trifunctional monomer of glyceryl glycidyl ether acryl ester manufactured by Nagase Kasei Co., Ltd. and having l = 1 in the general formula (IV)] Compound〕 (Effect of the Invention) The coating film obtained from the antifogging coating agent for inorganic glass of the present invention has excellent scratch resistance and antifogging durability, and is excellent in transparency, boiling water adhesion and moisture resistance. The coating film has good properties such as heat resistance and heat cycle resistance, and has the advantage of being extremely excellent in durability.

Claims (1)

(57) [Claims] 1. A copolymer comprising (A) a (meth) acrylate ester and a hydroxyl group-containing polymerizable unsaturated compound, and (B) a general formula (I) (Where Y is a vinyl group, an acryl group, a mercapto group, an amino group, and R ¹ is —CH ₂ —, —CH ₂ —CH ₂ —, —CH ₂ —
X represents CH ₂ —CH ₂ —, X ¹ represents —OCH ₃ or —OCH ₂ CH ₃ ,
Each may be the same or different. A silane coupling agent represented by the formula: and (C) a general formula (II) (Wherein, R ² in the formula represents a hydrogen atom or a methyl group, R ³
Is _{-O -, - CH 2 O -} , - CH 2 CH 2 O-, Is shown. ) Dicyclopentenyloxy (alkyl) represented by
(Meth) acrylate monomer, and if necessary, (D) a curing catalyst, and (A) / (B) / (C) are in a weight ratio of 40/10/50 to 94/1 / And (E) a general formula (III) [However, in the formula, at least three of X ² are (meth) acryloyloxy groups, the rest are hydroxyl groups, and n is an integer of 1 to 5. A polyfunctional (meth) acrylate monomer represented by the formula: and (F) a general formula (IV) (However, R ⁴ in the formula represents a hydrogen atom or a methyl group, and may be the same or different, and R ⁵ represents —CH ₂ —CH ₂ —, And each may be the same or different. M represents an integer of 1 to 50. A) a phosphoric acid ester monomer represented by the formula (V), and further, if necessary, a (G) curing catalyst and (H) a general formula (V) (However, 1 in the formula represents an integer of 1 to 5.) A trifunctional monomer of glyceryl glycidyl ether acrylate represented by the formula (E) / (F) / (H) A topcoat agent having a weight ratio of 90/10/10/30/60 by weight.