JP6933460B2 - UV curable resin composition and weather resistant hard coat film - Google Patents

Description

The present invention relates to an ultraviolet curable resin composition and a weather resistant hard coat film.

Conventionally, as a weather resistant hard coat film, a hard coat film containing an ultraviolet absorber is known. A weather-resistant hard coat film based on various plastic films such as polyethylene terephthalate (PET) film, acrylic film, and polycarbonate film is used.

However, the conventional weather-resistant hard coat film never has sufficient weather resistance, and the cured film has a strong yellow tint. As the name suggests, the ultraviolet curable resin composition is a resin composition that cures with ultraviolet rays, and it is necessary to add a large amount of an ultraviolet absorber in order to exhibit sufficient weather resistance performance. However, since it absorbs a large amount of ultraviolet rays, the cross-linking reaction at the time of ultraviolet curing is insufficient, resulting in insufficient curing, leading to a decrease in hardness and a decrease in adhesion to the substrate. To make up for it, it is necessary to carefully select the photopolymerization initiator. Document 1 describes a weather-resistant resin composition using a phosphine oxide-based photopolymerization initiator.

Patent No. 5948297

Since a phosphine oxide-based photopolymerization initiator has long-wavelength absorption characteristics, it is a means that can be used in combination with an ultraviolet absorber to have good ultraviolet absorption performance and weather resistance while maintaining curability during ultraviolet curing. Often used as. However, due to the long wavelength absorption characteristics, the paint cures under ordinary fluorescent lamps, so the usage environment is limited, and the yellowness of the cured coating film is slightly stronger than that of acetophenone-based photopolymerization initiators. there were. Moreover, the reactivity is not so high, and there is a problem in mass productivity at the time of film production.

The present invention is characterized by containing a (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups, one or more ultraviolet absorbers, and two or more photopolymerization initiators. Contains at least one selected from a benzophenone-based compound, a triazine-based compound, and a benzotriazole-based compound, and the photopolymerization initiator contains an oxime ester-based compound and an alkylphenone-based compound as essential components, and three or more (meth). ) With respect to 100 parts by weight of the (meth) acrylate monomer / oligomer having an acryloyl group, the ultraviolet absorber is 1 to 30 parts by weight, the total amount of the photopolymerization initiator is 1 to 20 parts by weight, and the oxime ester compound is 0. A UV curable resin composition containing 1 to 10 parts by weight and 0.1 to 5 parts by weight of a hindered amine-based light stabilizer.

The layer made of the ultraviolet curable resin composition of the present invention has high ultraviolet absorption performance and therefore has high weather resistance, and since an oxime ester compound is used as the photopolymerization initiator, the reaction rate is high and the film is produced. Mass productivity is also superior, leading to cost reduction.

Specific examples of the (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups include trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylol propanetri (meth) acrylate, and propylene oxide-modified tri. Methylolpropantri (meth) acrylate, trimethylpropantetra (meth) acrylate, tris (acryloxyethyl) isocyanurate, caprolactone-modified tris (acryloxyethyl) isocyanurate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) ) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate Examples thereof include meta) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate, and examples thereof include a mixture of two or more of these. In particular, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, or a mixture thereof is particularly preferable from the viewpoint of wear resistance and curability. Examples of the oligomer include polyfunctional urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, and acrylic acrylate.

The ultraviolet absorber contains at least one selected from benzophenone-based compounds, triazine-based compounds, and benzotriazole-based compounds. As a specific example, as the benzophenone compound, phenylsalicylate, 4-t-butylphenylsalicylate, 2,4-di-t-butylphenyl-3,5'-di-t-butyl-4'- Salicilet-based UV absorbers such as hydroxylbenzoate and 4-t-octylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4-hydroxy- 2-methoxyphenyl) methane, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 4- Examples thereof include dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4- (2-methacryloyloxyethoxy) benzophenone and the like.

Examples of triazine compounds include 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] 4,6-bis (2,4-dimethylphenyl) -1,3,5. -Triazine, 2- [4- (2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4 dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-Hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5- Triazine, 2,4-bis (2-hydroxy-4-butyloxyphenyl) -6- (2,4-bis-butyloxyphenyl) -1,3,5-triazine, 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'- Dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2, 2'-Dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy Examples thereof include hydroxyphenyltriazine-based ultraviolet absorbers such as -5,5'-disulfobenzophenone and disodium salt.

Examples of benzotriazole compounds include 2- (2'-hydroxy-5'-methylphenyl) benzotriazol and 2- [2'-hydroxy-3', 5'-bis (α, α-dimethylbenzyl) phenyl]. Bentotriazol, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) Bentotriazol, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-Chlorobenzotriazol, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzotriazol, 2- (2'-hydroxy-3) ′, 5′-di-t-amyl) benzotriazol, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazol, 2,2′-methylenebis [4- (1,1,3) , 3-Tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol] and the like.

These may be used alone or in combination of two or more. Among them, the hydroxyphenyltriazine-based ultraviolet absorber is preferable because the ultraviolet absorber itself is stable against ultraviolet rays and heat and has excellent absorption ability.

Commercially available UV absorbers include Tinuvin 326, 384-2, PS, 900, 400, 460, 477, 479 (manufactured by BASF), ADEKA STAB LA-29, 31, 36, 46, 1413 (manufactured by ADEKA Corporation). Hostabin ARO8, 3041, VSU (manufactured by Clariant) and the like can be mentioned.

The ultraviolet absorber is blended in an amount of 1 to 30 parts by weight based on 100 parts by weight of the (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups. More preferably, it is blended in an amount of 3 to 20 parts by weight. If it is less than 1 part by weight, the coating film will turn yellow during the weather resistance test and the adhesion to the base material will decrease. If it exceeds 30 parts by weight, the curability is lowered, and the pencil hardness and the adhesion to the base material are lowered.

The photopolymerization initiator contains an oxime ester compound as an essential component. Specific examples include 1,2-octanedione, 1- (4- (phenylthio)-, 2- (O-benzoyloxime)), etanone, 1- (9-ethyl-6- (2-methylbenzoyl) -9H). -Carbazole-3-yl)-, 1- (O-acetyloxime) and the like can be mentioned. Examples of commercially available oxime ester-based photopolymerization initiators include OXE01, 02, 03, 04 (manufactured by BASF), NCI-930, and N-1919 (manufactured by ADEKA Corporation).

The photopolymerization initiator used in combination is not particularly limited, and acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, benzoin, and benzoinmethyl Examples thereof include carbonyl compounds such as ether, benzoin ethyl ether and benzoin isopropyl ether, and sulfur compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone and tetramethylthium disulfide. Among them, it is preferable to mainly use an alkylphenone-based photopolymerization initiator from the viewpoints of curability, photostability, compatibility, low volatility, and low odor of the curable resin composition, and 1-hydroxycyclohexylphenylketone and 2-hydroxy Examples thereof include -2-methyl-1-phenyl-propane-1-one and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one. As a commercially available photoinitiator, Irgacure1173, 127, 184, 369, 500, 651, 754, 2959 (manufactured by BASF) and the like can be used.

The photopolymerization initiator is 1 to 20 parts by weight based on 100 parts by weight of the (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups, of which 0.1 part to 10 parts by weight of an oxime ester compound. Mix by weight. More preferably, the photopolymerization initiator is contained in an amount of 3 to 10 parts by weight, and the oxime ester compound is preferably contained in an amount of 0.3 to 5 parts by weight. If the amount is not enough, the curability is lowered and the adhesion to the base material is lowered. If the amount exceeds the above amount, yellowing of the coating film will occur due to an excessive initiator, and the raw material cost will increase.

The hindered amine-based light stabilizer interacts with the ultraviolet absorber to suppress weathering yellowing of the coating film. Specifically, for example, phenyl-4-piperidinyl carbonate, bis- (2,2,6,6-tetramethyl-4-piperidinyl) sevacate, bis- (n-methyl-2,2,6,6). -Tetramethyl-4-piperidinyl) sebacate, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2 Examples thereof include -n-butylmalonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate and the like. As commercially available products, Tinuvin123, 292, 249 (manufactured by BASF), ADEKA STAB LA-52, 57, 72, 82, 87 (manufactured by ADEKA Corporation) and the like can be used.

The hindered amine-based light stabilizer is blended in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups. If it is less than 0.1 part by weight, the coating film tends to yellow during the weather resistance test, and if it exceeds 5 parts by weight, there is a concern of bleed-out, and whitening of the coating film tends to occur.

Further, the ultraviolet curable resin composition of the present invention contains, if necessary, an organic solvent, an antioxidant, a brewing agent, a pigment, a leveling agent, an antifoaming agent, a thickener, an antioxidant, an antistatic agent, and the like. Antifogging agents, slip agents, antibacterial agents and the like may be added.

The above components are diluted with a solvent to adjust the solid content to 10 to 80%. Examples of the solvent include alcohol solvents such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol and diacetone alcohol, methyl cellosolve and ethyl cellosolve. , Cellosolve solvents such as butyl cellosolve, n-propyl cellosolve, ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, isophorone, ester solvents such as methyl formate, butyl formate, methyl acetate, butyl acetate, etc. Examples thereof include ether solvents such as diethyl ether and diisopropylate, and amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide.

Examples of the plastic film to which the ultraviolet curable resin composition is applied include polyester film, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, and polyvinylidene chloride film. , Polyvinyl alcohol film, ethylene vinyl alcohol film, polystyrene film, polycarbonate film, polymethylpentene film, polysulphon film, polyether ether ketone film, polyether sulfone film, polyetherimide film, polyimide film, fluorine resin film, nylon film , Acrylic film, cycloolefin (co) polymer film and the like.

Among them, a biaxially stretched polyester film is preferably used from the viewpoint of price, processability, dimensional stability, etc., and an acrylic film or polycarbonate film is preferably used from the viewpoint of weather resistance. The thickness of the film may be approximately 23 μm to 250 μm.

For the purpose of improving the adhesion to the ultraviolet curable resin composition, the above film is subjected to surface unevenness treatment by primer treatment, corona treatment, sandblasting method, solvent treatment, etc., chromic acid treatment, ozone / ultraviolet rays. Surface treatment such as surface oxidation treatment such as irradiation treatment can be performed.

The method of applying the ultraviolet curable resin composition is not particularly limited, and is a coating method such as a known spray coat, roll coat, die coat, air knife coat, blade coat, spin coat, reverse coat, gravure coat, wire bar, or gravure. It can be formed by printing methods such as printing, screen printing, offset printing, and inkjet printing. The dry film thickness is preferably 0.5 μm to 10 μm.

After applying the ultraviolet curable resin composition, it is dried at 60 to 120 ° C. UV-curable resin composition, using an ultraviolet irradiator at an irradiation intensity of ^{500mW / cm 2 ~3000mW / cm 2} , the amount of work hardening with ultraviolet processing 50~400mJ / cm ^2. An ultraviolet lamp is generally used as an ultraviolet source, and specific examples thereof include a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, and a metal halide lamp. It may be an inert gas such as nitrogen or argon.

Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples, but specific examples are shown and the present invention is not particularly limited thereto. The weight part indicates the solid content weight. The compounding examples in the table are all solid content weights.

Reference example 1
(A) Dipentaerythritol hexaacrylate (trade name: KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., 100% solid content) 100 parts by weight,
(B) Ultraviolet absorber (trade name: Tinuvin326, manufactured by BASF, benzotriazole type) 1.5 parts by weight,
(C1) Photopolymerization Initiator (trade name: Irgacure184, manufactured by BASF, α-hydroxyacetophenone type), 5 parts by weight,
(C2) Photopolymerization initiator (trade name: OXE01, manufactured by BASF, oxime ester type) 0.3 parts by weight,
MEK (methyl ethyl ketone) and cyclohexanone were blended as a diluting solvent to obtain an ultraviolet curable resin composition having a solid content of 40% by weight.

Next, the ultraviolet curable resin composition was applied to a PET film (trade name, 125U403, manufactured by Toray Co., Ltd.) having a thickness of 125 μm with a # 10 bar coater so that the resin film thickness after curing was 4.0 μm. , dried 80 ° C. 1 min, an irradiation intensity of 1500 mW / cm ² using UV irradiation machine (high-pressure mercury lamp), the amount of work with ultraviolet processing 150 mJ / cm ^2, to obtain a weather-resistant hard coat film.

Example 1
In Reference Example 1 , the same procedure was carried out except that (D) a hindered amine-based light stabilizer (trade name: Tinuvin249, manufactured by BASF) was blended in 2 parts by weight.

Reference example 2
In Reference Example 1 , 25 parts by weight of (B) was blended and 1 part by weight of (C2) was added, but the same procedure was carried out.

Example 2
In Reference Example 2 , the same procedure was carried out except that (D) Tinuvin 249 was blended in 2 parts by weight.

Reference example 3
In Reference Example 1 , (B) was changed to Tinuvin477 (manufactured by BASF, a triazine-based ultraviolet absorber), and (C2) was changed to OXE04 (manufactured by BASF, an oxime ester-based agent).

Reference example 4
In Reference Example 3 , the same procedure was carried out except that (B) was 25 parts by weight.

Example 3
In Reference Example 1 , (B) is 5 parts by weight of Tinuvin 477.
5 parts by weight of Tinvin479 (BASF, triazine-based UV absorber), 2 parts by weight of (D) Tinuvin249, 10 parts by weight of (C1) changed to Irgacure2959 (BASF, α-hydroxyacetophenone), (C2) ) Was changed to OXE04 to 0.5 parts by weight, and the same procedure was carried out.

Example 4
In Example 3 , (B) Tinuvin 477 was 10 parts by weight, Tinuvin 479 was 10 parts by weight, and (C2) was 2 parts by weight.

Example 5
In Example 1 , (A) was changed to urethane acrylate oligomer (trade name: RUA076MG, manufactured by Asia Industries Co., Ltd., solid content 100%), and (B) was changed to Uvinul3049 (manufactured by BASF, benzophenone-based ultraviolet absorber). The same procedure was carried out except that 5 parts by weight and (C2) were changed to NCI-930 (manufactured by ADEKA Co., Ltd., oxime ester type) to 1 part by weight.

Comparative Example 1
In Reference Example 1 , the same procedure was carried out except that (B) was set to 0.1 parts by weight.

Comparative Example 2
In Reference Example 1 , the same procedure was carried out except that (B) was set to 40 parts by weight.

Comparative Example 3
In Comparative Example 2, the same procedure was carried out except that (B) was Tinuvin 477.

Comparative Example 4
In Reference Example 3 , (B) was set to 10 parts by weight, and (C2) OXE04 was removed from the formulation in the same manner.

Comparative Example 5
In Comparative Example 4, the same procedure was carried out except that (B) was Tinuvin 479.

Comparative Example 6
In Example 3 , (C1) was set to 0.5 parts by weight, and (C2) OXE04 was removed from the formulation in the same manner.

Comparative Example 7
In Comparative Example 6, the same procedure was carried out except that (C1) was 30 parts by weight and (C2) OXE04 was blended in 15 parts by weight.

Comparative Example 8
In Comparative Example 4, 0.3 parts by weight of (C2) OXE01 was blended, and 10 parts by weight of (D) was blended, but the same procedure was carried out.

The evaluation results are shown in Tables 1 and 2.

The evaluation method was as follows.
(1) Total light transmittance: Measured based on JIS K 7361-1.
(2) Haze: Measurement of haze value (Hz): Measurement was performed by a haze meter (manufactured by Toyo Seiki Seisakusho Co., Ltd., trade name Haze Guard II) based on the provisions of JIS K 7136 (2000 version).
(3) Pencil hardness: Based on JIS K5600-5-4, evaluation was performed with a load of 750 g.
(4) b *: Measured based on JIS Z 8722.
(5) Adhesion to base material: A test was conducted based on JIS K5600, and the number of squares that were not peeled out of the 100 squares was described.
Without peeling: 100/100
With peeling: 0/100 to 99/100
(6) Weather resistance test: Irradiation was carried out at 60 ° C. for 500 hours with a ^{UVA lamp (0.63 W / m 2 @ 340 nm) using a QUV tester.} The UVA lamp was irradiated from the coating film surface. Then, the tests of (4) and (5) were carried out in the same manner.

Claims (2)

It contains a (meth) acrylate monomer / oligomer having three or more (meth) acryloyl groups, one or more ultraviolet absorbers and two or more photopolymerization initiators, and the ultraviolet absorbers are benzophenone compounds and triazine compounds. The photopolymerization initiator contains at least one selected from a compound and a benzotriazole-based compound, contains an oxime ester-based compound and an alkylphenone-based compound as essential components, and has the above-mentioned three or more (meth) acryloyl groups (meth). ) With respect to 100 parts by weight of the acrylate monomer / oligomer, 1 to 30 parts by weight of the ultraviolet absorber, 1 to 20 parts by weight of the total amount of the photopolymerization initiator, and 0.1 to 10 parts by weight of the oxime ester compound. An ultraviolet curable resin composition containing 0.1 to 5 parts by weight of a hindered amine-based light stabilizer. A weather-resistant hard coat film, wherein a coating film of the ultraviolet curable resin composition according to claim 1 is formed on a plastic base material.