JPH0948935A - Coating composition for container and container with cured coating film formed therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultraviolet-screening coating compsn. for various containers by compounding a monomer compsn. comprising a monomer having at least three (meth)acryloyloxy groups and a monomer having one or two (meth)acryloyloxy groups with an acylphosphine photopolymn. initiator and an ultraviolet absorber. SOLUTION: This compsn. is prepd. by compounding 100 pts.wt. monomer compsn. comprising. 10-90wt.% polyfunctional monomer having at least three (meth)acryloyloxy groups (pref. pentaerythritol tetraacrylate) and 90-10wt.% monomer having one or two (meth)acryloyloxy groups (pref. cyclohexyl acrylate) with 0.5-20 pts.wt acylphosphine oxide compd. (esp. pref. a compd. represented by the formula) as the photopolymn. initiator and an ultraviolet absorber. When both the photopolymn. initiator and the ultraviolet absorber used exhibit ultraviolet absorption in the wavelengths of 350-380nm, a cured coating film absorbing ultraviolet rays with wavelengths of 400nm or lower is obtd. The obtd. cured coating film also has a good printability.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition for a container and a container having a cured coating thereof. More specifically, the present invention relates to a coating composition for producing a container having an ultraviolet blocking property suitable for use as a container for raw materials, products, etc., which are easily deteriorated by ultraviolet rays, and a container coated with a cured product of the composition.

[0002]

2. Description of the Related Art Various containers such as glass and plastic are used for cosmetics, foods, medicines or quasi-drugs, health drinks,
Widely used as a container for alcoholic beverages. These containers are often supplied as colorless transparent containers, but the container or the container surface is colored depending on the purpose of use, or the container surface is matted to give the container design. Also, various treatments are performed for the purpose of preventing changes in the physical properties of the contents. Specifically, when the contents are likely to be deteriorated by ultraviolet rays, the purpose is to color the container or the container surface for the purpose of blocking the ultraviolet rays, or to prevent the ultraviolet rays from being diffusely reflected on the container surface to penetrate into the container. A container that has been matt-treated is used.

[0003] However, the conventional containers used are Ce and F in the glass raw material in order to prevent alteration of the contents.
It is manufactured by molding colored glass that is melted at high temperature by adding metal compounds such as e, Cr, Cu and Co, but it requires a high temperature to develop a color tone that suits the purpose, and the obtained color tone However, there is a problem in that it is not possible to obtain a glass bottle of uniform quality, such as different from the intended one, or the color tone differs from lot to lot. In addition, a method of etching with hydrofluoric acid (mixed with sulfuric acid in some cases) is usually used to manufacture a glass bottle whose surface has been delustered. In addition to the need for careful handling, many steps such as pickling and rinsing are required.
The waste liquid discharged from each process is also required, which raises a problem of increasing manufacturing cost.

[0004]

In a plastic container, in order to solve this problem, a method of kneading an ultraviolet absorber or the like into a container material to give an ultraviolet blocking property to the container has been found. The container obtained by this method has a problem that the kneaded ultraviolet absorber or the like is eluted into the container and the contents are altered. Therefore, as a solution to such problems, a coating material that imparts an ultraviolet blocking property to the surface of a container, is excellent in container production equipment, productivity, environmental problems, etc., and is a light-curable coating composition. As such, a glass coating composition as described in JP-A-61-209927 has been proposed, but such a conventional ultraviolet blocking coating composition has an adhesive property to a substrate. However, there is a problem such as yellowing during heating, which is not yet fully satisfactory in practical use.

The present invention has been made in view of the above circumstances, and it is a photopolymerizable coating composition capable of imparting an ultraviolet blocking property very simply by coating the surface of a container and photocuring. The purpose is to provide.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have identified a photopolymerization initiator having an ultraviolet absorbing ability at a specific wavelength and a specific ultraviolet absorbent. The coating composition containing the amount is applied to a container, and by irradiating ultraviolet rays to cure this coating film, it is found that a container having a cured coating having an excellent ultraviolet blocking property can be obtained, and the object of the present invention. To solve the problem.

That is, the present invention provides (a) 3 in one molecule.
10 to 90% by weight of a polyfunctional monomer having 1 or more (meth) acryloyloxy groups, and (b) a 1 to 2 functional monomer having 1 to 2 (meth) acryloyloxy groups in one molecule. 90 to 10% by weight of a curable composition (I)
And 0.5 to 20 with respect to 100 parts by weight of the component (I).
A first invention is a coating composition for a container, which comprises 1 part by weight of at least one acylphosphine oxide compound (c) and 2 to 30 parts by weight of an ultraviolet absorber (d). The cured film of the composition is capable of imparting excellent ultraviolet blocking properties by the action of the photopolymerization initiator and the ultraviolet absorber in the specified amounts contained therein.

The second invention of the present invention is (a) 10 to 90% by weight of a polyfunctional monomer having three or more (meth) acryloyloxy groups in one molecule, and (b) one in one molecule. A curable composition (I) containing 90 to 10% by weight of 1 to 2 functional monomer having 2 to 2 (meth) acryloyloxy groups.
40 to 95% by weight, acrylic copolymer (II) 60 to 5
% By weight, and the total amount of the component (I) and the component (II) is 10
With respect to 0 parts by weight, (c) 0.5 to 20 parts by weight of a photopolymerization initiator composed of at least one or more acylphosphine oxide compounds, and (d) 2 to 30 parts by weight of an ultraviolet absorber. A coating composition for a container, which comprises:
By using an acrylic polymer in combination with the curable composition of the invention, the leveling property and wettability of the coating film when applied to the container surface are improved, and the cured coating film is applied to the container substrate. It is possible to improve the adhesive property of the above, and it is particularly suitable for a container made of a polyolefin resin or a polyester resin, which is a material having poor adhesion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
First, the coating composition of the present invention will be described.

The curable composition (I) used in the composition of the present invention comprises (a) 10 to 90% by weight of a polyfunctional monomer having 3 or more (meth) acryloyloxy groups in one molecule, and (B) A mixture containing 90 to 10% by weight of a 1 to 2 functional monomer having 1 to 2 (meth) acryloyloxy groups in one molecule. Among these, (a) of the present invention
The polyfunctional monomer having three or more (meth) acryloyloxy groups in one molecule, which is a component, is a component that imparts curability and solvent resistance to the coating composition of the present invention.

Specific examples thereof include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate. Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol Hepta (meth) acrylate, tripentaerythritol octa (meth) acrylate, etc. are mentioned. Among the above, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate are particularly preferable in that the curing speed can be increased.

These polyfunctional monomers can be used alone or in combination of two or more. Further, 1 to 2 which is another component of the curable composition (I) of the present invention and which has 1 to 2 (meth) acryloyloxy groups in one molecule.
The bifunctional monomer (b) is a component that adjusts the curability, the degree of crosslinking, and the viscosity of the coating composition of the present invention.

Specific examples of this include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate,
t-butyl (meth) acrylate, isobutyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, 2-di Cyclopentenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth ) Acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4
Monofunctional (meth) acrylate monomers such as hydroxybutyl (meth) acrylate, (meth) acrylic acid, (meth) acryloylmorpholine; ethylene glycol di (meth) acrylate, 1,3-propylene glycol di (meth) acrylate 1,4-heptanediol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, tetraethylene glycol di (meth) acrylate, 2-butyne-1,4-di (meth) acrylate, cyclohexane-1,4-dimethanol (meth)
Acrylate, hydrogenated bisphenol A di (meth) acrylate, 1,5-pentanedi (meth) acrylate,
Trimethylolethane di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, trimethylolpropane di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 2,2-bis- (4- (meth) acryloxypropoxyphenyl) propane, 2,2-bis- (4- (meth) acryloxy (2-hydroxypropoxy) phenyl) propane, bis- (2- (meth)) Examples thereof include bifunctional (meth) acrylate monomers such as acryloyloxyethyl) phthalate.

Among the above, 2-ethylhexyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-dicyclopentenoxyethyl acrylate, isobornyl, which have good curability and low viscosity. Acrylate, tetrahydrofurfuryl acrylate, hydrogenated bisphenol A diacrylate, cyclohexane-1,
4-dimethanol diacrylate and tricyclodecane dimethanol diacrylate are particularly preferable. These one
The difunctional monomer may be used alone or in combination of two or more.

The mixing ratio of the component (a) and the component (b) in the curable composition (I) used in the present invention is
(A) / (b) = 10 to 90/90 to 10 (wt%), and particularly preferably (a) / (b) = 30 to 70 /
70 to 30 (% by weight). When the amount of the component (a) in the curable composition (I) is less than 10% by weight, the degree of crosslinking of the curable composition becomes too small and the curability decreases.
This is because a cured coating having sufficient performance such as solvent resistance cannot be obtained. On the contrary, when the content of the component (a) is more than 90% by weight, the degree of crosslinking of the curable composition becomes too high, resulting in a cured film having insufficient adhesion to the substrate.

The acylphosphine photopolymerization initiator used as the photopolymerization initiator of the component (c) in the present invention is a compound having an ultraviolet absorption wavelength in the high range of 360 to 400 nm. In the present invention, among them, the ultraviolet absorption wavelength is 370 to 370.
The range of 380 nm is preferable, and the acylphosphine compounds represented by the following general formulas (1) to (3) are particularly preferable. Since it is possible to block ultraviolet rays having a wavelength of 400 nm or less, it is possible to protect the contents of the container which are easily deteriorated by the ultraviolet rays. Further, in the case of the type in which the ultraviolet absorber is kneaded into the conventional container base material, the ultraviolet absorber may be eluted into the container contents, but the present invention is a coating material composition, and therefore this problem can be solved. It is a thing.

[0017]

Embedded image

These photopolymerization initiators may be used either individually or in combination of two or more. Further, a photopolymerization initiator other than the acylphosphine oxide-based photopolymerization initiator (c) can be used in combination, and in this case, the component (c) in the photopolymerization initiator is in the range of 5% by weight or more. It is preferable to contain. When this content is less than 5% by weight, the curability of the coating composition is lowered, and the hardness and solvent resistance of the cured coating become poor.

Other photopolymerization initiators that can be used as the component (c) of the present invention include, for example, benzoin and
Benzoin monomethyl ether, benzoin isopropyl ether, acetoin, benzyl, benzophenone,
p-methoxybenzophenone, diethoxyacetophenone, benzyldimethylketal, 2,2-diethoxyacetophenone, 1-hydroxycyclohexylphenylketone, methylphenylglyoxylate, ethylphenylglyoxylate, 2-hydroxy-2-methyl-
Examples thereof include carbonyl compounds such as 1-phenylpropan-1-one and 2-ethylanthraquinone, and sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide. Of these, 1-hydroxycyclohexyl phenyl ketone, which has good curability, is particularly preferable.

The content of the component (c) is the curable composition (I) or the acrylic copolymer (I) used in the present invention.
It can be used in the range of 0.5 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the total amount of I). When the content of the component (c) is less than 0.5 part by weight, the curability of the coating composition is lowered and the cured film has the desired physical properties. On the other hand, when the content of the component (c) is more than 20 parts by weight, the curability of the curable composition becomes too high, resulting in poor adhesion and poor yellowing of the cured coating. Occurs.

The ultraviolet absorber, which is the component (d) of the present invention, is a component used for imparting an ultraviolet blocking property to the formed cured film. Therefore, the ultraviolet absorption wavelength is 35
By using an ultraviolet absorber having a range of 0 to 380 nm, it is possible to obtain a cured coating that absorbs ultraviolet rays of 400 nm or less, which is the object of the present invention.

Specific examples thereof include 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-.
4-octyloxybenzophenone, 4-dodecyloxy-
2-hydroxybenzophenone, 2-hydroxy-4-
Octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, p- (1,1,3 , 3, -Tetramethylbutyl) phenyl salicylate, 3-hydroxyphenylbenzoate, phenylene-1,3-dibenzoate, 2- (2
-Hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-5tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy3,5-dipentylphenyl) triazole, 2
-(2-hydroxy-3,5-di-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-5-
tert-butylphenyl) benzotriazole, 2- (2
-Hydroxy-4-octyloxy-4-octyloxyfuconyl) benzotriazole and the like. These ultraviolet absorbers can be used alone or in combination of two or more.

The content of the component (d) is 2 to 30 parts by weight based on 100 parts by weight of the total amount of the curable composition (I) or the curable composition (I) and the acrylic copolymer (II). And preferably in the range of 4 to 20 parts by weight. With the coating composition containing less than 2 parts by weight of the component (d), the ultraviolet absorption is low and a cured coating having sufficient ultraviolet blocking properties cannot be obtained. On the contrary, when the amount of the component (d) is more than 30 parts by weight, the ultraviolet energy required for curing the curable composition is absorbed in the component (d) in a large amount and the curability is lowered. However, it causes deterioration of various physical properties of the cured film and yellowing.

The acrylic copolymer which is the component (II) used in the present invention is used in combination with the curable composition (I), whereby the leveling property and wettability of the coating film are improved. In addition, it is a component that can improve the adhesion of the cured coating to the substrate, especially to the substrate of a material having poor adhesion. Examples of the monomer constituting the acrylic copolymer that can be contained in the composition of the present invention include (meth) acrylic acid alkyl ester, hydroxyl group-containing (meth) acrylate, carboxy group-containing vinyl monomer, basic monomer, and styrene derivative. , Polymerizable unsaturated nitriles, vinyl esters and the like. Among these monomers (1) to (3), (meth) acrylic acid alkyl ester having good compatibility is particularly preferable.

Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate and t-butyl (meth). ) Acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like.

Specific examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, adducts of 2-hydroxyethyl (meth) acrylate and ethylene oxide,
Addition product of 2-hydroxyethyl (meth) acrylate and propylene oxide, 2-hydroxyester (meth)
Examples thereof include an adduct of 2-hydroxyethyl (meth) acrylate with an organic lactone such as an adduct of acrylate with ε-caprolactone.

Specific examples of the carboxy group-containing vinyl monomer include (meth) acrylic acid, itaconic acid, fumaric acid, crotonic acid, maleic acid, monomethyl itaconate,
Examples thereof include monobutyl itaconate, monomethyl maleate, and monobutyl itaconate.

Specific examples of the basic monomer include N-
N-alkoxy-substituted amides such as methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, glycidyl (meth) acrylate, (meth) allyl glycidyl ether, and metaglycidyl ( Examples thereof include epoxy group-containing monomers such as (meth) acrylic acid esters, dimethylaminoethyl (meth) acrylic acid, and diethylaminoethyl (meth) acrylic acid.

Specific examples of the styrene derivative include styrene, α-methylstyrene, vinyltoluene and the like. Specific examples of the polymerizable unsaturated nitriles include (meth)
Acryloyl nitrile etc. are mentioned. Specific examples of the vinyl esters include vinyl acetate and vinyl propionate.

The method for polymerizing the acrylic copolymer in the present invention may be any known polymerization method such as solution polymerization method, bulk polymerization method and emulsion polymerization method. Is desirable. For example,
When the solution polymerization method is used, the monomer mixture may be copolymerized in the presence of an organic solvent and a polymerization initiator.

When it is necessary to improve the adhesion of the cured coating to the container, the acrylic copolymer (II) is added to the curable composition (I) in an amount of 40 to 95% by weight.
The amount is preferably contained in the range of 5 to 5% by weight, and more preferably in the range of 50 to 10% by weight.

When the amount of the acrylic copolymer compounded is more than 60 parts by weight, the degree of crosslinking of the coating composition becomes too small, resulting in a cured coating film with low physical properties. Conversely, 5
If the amount is less than the weight part, the adhesiveness cannot be improved, and the cured coating film has insufficient adhesiveness to the poorly adherent material.

As the matting agent which is the component (e) of the present invention, inorganic or organic fine particles can be used. For example, as a specific example of the inorganic fine particles, glass (for example, manufactured by Toshiba Barody Co., Ltd .; trade name: GB731M, GB
731MC, etc., silica (for example, manufactured by Degussa; trade name: OK412, manufactured by Mizusawa Chemical Co., Ltd .; trade name P-52).
6, P-101, manufactured by Fuji Silysia Chemical Ltd .; trade name Sylysia 435), calcium carbonate and the like can be used.
Among these, silica having a small particle size and a matting effect is particularly preferable.

Specific examples of organic fine particles include fine particles made of polyethylene (for example, Giflat Ceramic Mfg. Co., Ltd .; trade name Hiflat T-10P-5), polycarbonate resin, polyurethane resin, fluororesin and the like. . Of these, a polycarbonate resin may be mentioned in consideration of the balance between dispersibility in the coating composition and abrasion resistance of the cured coating.

The fine particle size of the matting agent used in the present invention is not particularly limited, but a range of 1 to 25 μm, particularly a range of 2 to 15 μm can be preferably used. If the particle size is less than 1 μm, a good matting effect tends not to be obtained, while if the particle size is greater than 25 μm, the surface of the coating film obtained by curing the composition of the present invention is excessively rough. This is because there is a tendency that the appearance and the designability are deteriorated.

The content of the component (e) is 1 to 20 parts by weight based on 100 parts by weight of the total amount of the curable composition (I) or the curable composition (I) and the acrylic copolymer (II). It is particularly preferable to set the range of parts to 5 to 15 parts by weight. When the content of the component (e) is less than 1 part by weight, the matte feeling is weak and a cured coating film exhibiting a good matte feeling cannot be obtained. On the other hand, when the content of the component (e) is more than 20 parts by weight, the matte feeling is poor, the appearance is poor such as whitening and roughening, and the cured film has low physical properties due to deterioration in curability.

The coating composition of the present invention further comprises known plasticizers, defoaming agents, surfactants, leveling agents, cups, etc. within the range not impairing the coating properties such as the ultraviolet ray blocking property aimed at by the present invention. Additives such as ring agents and colorants such as pigments and dyes can be added. Particularly, in the case of glass or a resin having poor adhesion, it is preferable to add a coupling agent for the purpose of improving the adhesion of the curable film.

Further, for example, a colorant such as a pigment or a dye may be added to color the cured film to obtain a container having a further excellent ultraviolet blocking property. When opaque coloring is applied to the cured film, pigments and dyes can be used. However, when a pigment is used, a small amount causes opaque coloring, which makes it impossible to see through the contents in the container, resulting in a small design effect.
Therefore, it is preferable to use a dye because the workability for adjusting the degree of coloring density is good.

Specifically, for semitransparent coloring, the pigment may be added to the coating composition in an amount of less than 10% by weight, and the dye may be added in an amount of less than 50% by weight. On the other hand, when opaque coloring is performed, the pigment content is 10% by weight or more and the dye content is 50% by weight with respect to the coating composition.
Although it may be added in the above range, the curability is lower than that in the case of semi-transparent coloring.

The coating composition of the present invention can be used as it is for coating a container, but when it has a high viscosity,
It is preferable to adjust the viscosity to an optimum level with an organic solvent so as to be suitable for the step of applying the coating composition to a container and use it. The organic solvent that can be added to the coating composition of the present invention is not particularly limited. Specific examples of this include acetone,
Ketone compounds such as methyl ethyl ketone and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate and methoxyethyl acetate; diethyl ether, ethylene glycol dimethyl ether,
Dioxane Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ether compounds such as tetrahydrofuran; aromatic compounds such as toluene, xylene, mineral spirits; aliphatic compounds such as pentane, hexane, cyclohexane; butyl alcohol, isopropyl alcohol, etc. Examples of the alcohol compound include halogenated hydrocarbons such as methylene chloride, chlorobenzene and chloroform. Of these, toluene and butyl acetate, which have relatively low boiling points, are particularly preferable.

The method for applying the coating composition of the present invention thus obtained to a container is a known method, for example, a spray coating method, a dip coating method, a spin coating method,
A curtain coating method, a brush coating method and the like can be mentioned, but the spray coating method is preferable from the viewpoint of coating workability, smoothness of cured film, uniformity and the like.

The thickness of the coating film is not particularly limited, but is generally in the range of 1 to 50 μm, preferably 5 to 20 μm. When the film thickness is thicker than 20 μm, the curability is deteriorated, and in the case of a coating composition to which a matting agent is added, the matting agent sinks in the coating film to exert the effect of the matting agent. Can not be. If the film thickness is less than 5 μm, the ultraviolet ray blocking property becomes poor.

The coating composition of the present invention comprises a xenon lamp,
The coating film can be easily cured in a short time by irradiating ultraviolet rays using a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, a Dangsten lamp, or the like.

The container to which the cured film of the coating composition of the present invention is applied is not particularly limited to an inorganic material such as glass or an organic material such as (meth) acrylic resin or polyester resin. Thus, by using the coating composition of the present invention, it is possible to obtain a container having a coating excellent in ultraviolet ray blocking property, for example, raw materials that are easily deteriorated by ultraviolet rays, foods, pharmaceuticals, cosmetics, alcoholic beverages, etc. It can be used in all fields in which an article and / or a container substrate itself should be protected from ultraviolet rays. Further, the cured film of the coating composition of the present invention not only has an ultraviolet blocking property, but also has good stampability and printability, so without labeling or film laminating a container having this cured film,
It is possible to obtain a container which can be directly stamped or printed, and which is excellent in productivity and design, can be manufactured at low cost and saves resources.

[0045]

The present invention will be described below in detail with reference to examples. The parts used in the examples and the amounts of the components used in the tables are parts by weight, and the abbreviations used in the examples are as follows. DP6A: Dipentaerythritol Hexaacrylate THFA: Tetrahydrofurfuryl acrylate Acrylic Copolymer: (Brand Name Diinal SE-5
377; manufactured by Mitsubishi Rayon Co., Ltd. TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide [acylphosphine oxide-based photopolymerization initiator (trade name: Lucilin TPO; manufactured by BASF Japan Ltd.)] BP: benzophenone BDK: Benzyl dimethyl ketal TYN: UV absorber (trade name: Tinuvin 327; manufactured by Ciba Geigy) IPA: Isopropyl alcohol (e-1): Matting agent (trade name: Sylysia 435; manufactured by Fuji Silysia)

The method for evaluating a cured coating having a film thickness in the range of 10 to 15 μm obtained by curing the coating composition obtained in the examples is as follows. [Evaluation Method] The following evaluation was performed on the cured film obtained by applying and curing the coating composition on an acrylic plate.・ Adhesiveness (cross-cut peeling test) Cross-cut with a cutter at 1 mm intervals in 10 rows and 10 rows, and stick cellophane tape (manufactured by Nichiban Co., Ltd.) on the surface,
Before the test was set to 100/100 (no peeling), the peeling was performed in the vertical direction rapidly, and the number of peeled / 100 was described. -Hardness It carried out according to JIS K5400. The pencil I used is
It is UNI pencil 9H (hard) to 6B (soft) manufactured by Mitsubishi Pencil Co., Ltd.・ Solvent resistance MEK rubbing test ... 50 including MEK in gauze
The state of the cured film after the reciprocating rubbing test was visually evaluated. ◯: No abnormality X: Abnormality-Appearance The yellowing of the surface of the cured coating and other abnormalities were visually evaluated. ◯: No abnormality Δ: Some yellowing x: Yellowing-Glossy appearance The state of the cured film of the coating composition containing the matting agent was visually evaluated. ◯: There is a matte feeling x: There is no matte feeling ・ Ultraviolet absorption rate The ultraviolet absorption rate of the cured film was measured using a self-recording spectrophotometer, trade name U3400 type (manufactured by Hitachi, Ltd.).・ Hot stamping property A rubber stamp is pressed on the obtained cured coating at 230 ° C. for 1 second, and the stamp is imprinted. Then, the stamp is cured in the same manner as in the evaluation method of the adhesiveness (cross-cut peeling test) described above. The adhesion with the coating was evaluated. ◯: The stamp was clearly imprinted without peeling. Δ: The stamp was clearly imprinted, but there was partial peeling. ×: Whole surface peeling. ・ Printability. The cured film obtained had a film thickness of 200 μm by the screen printing method.
After printing m for 20 minutes at 60 ° C., the adhesion of the printing ink to the cured film was evaluated in the same manner as the evaluation method for the adhesion (cross-cut peeling test). ◯: Vividly printed, no peeling ×: Printing is unclear and peels off the entire surface or cannot be printed at all

Example 1 DP6A and THFA are shown in Table 1.
In 100 parts of the curable composition mixed in the ratio shown in Table 1, TPO2 as an acylphosphine oxide photopolymerization initiator was added.
Parts, TYN 10 parts as a UV absorber, toluene 6
0 parts, 60 parts of butyl acetate, and 30 parts of N-butanol were mixed by stirring to obtain a coating composition having a uniform solution. This is I
The outer surface of the acrylic plate and the acrylic container degreased and washed with PA was spray-coated so that the film thickness after drying was 5 to 10 μm, and the coating was dried at 60 ° C. for 3 minutes and then about 1000 mJ.
By irradiating with an ultraviolet ray of an energy amount of / cm ² , an acrylic plate coated with the composition having an ultraviolet blocking property and an acrylic container were obtained. As a result of this evaluation, good results as shown in Table 1 were obtained.

[0048]

[Table 1]

[Example 2] TYN1 as an ultraviolet absorber was added to 100 parts of the curable composition used in Example 1-.
Example 1 except that 0 part of each of the acylphosphine oxide-based photopolymerization initiators shown in Table 2 and 1.0 part of each of the non-acylphosphine oxide-based photopolymerization initiators were added. A coating composition was produced in the same manner. Using the obtained composition, a cured coating film was formed under the same conditions as in Example 1 and evaluated. The evaluation results are shown in Table 2.

[0050]

[Table 2]

[Example 3] Except that 100 parts of the curable composition used in Example 1 was added with TYN as an ultraviolet absorber in the amount shown in Table 3 and 2 parts of TPO as a photopolymerization initiator. A coating composition was produced in the same manner as in Example 1. Using the obtained composition, a cured coating film was formed under the same conditions as in Example 1 and evaluated. As a result, good results as shown in Table 3 were obtained.

[0052]

[Table 3]

[Example 4] Table 4 shows DP-6A and THFA.
A coating composition was obtained in the same manner as in Example 1 except that 100 parts by weight of the resin component, which was a mixture of the curable composition and the acrylic copolymer, which were mixed in the ratio shown in Table 1, was used. This is the IPA
A polypropylene resin plate and a polypropylene container, which are non-adhesive resins whose surface of the substrate has been activated by degreasing and washing with a flame treatment, were applied and cured under the same conditions as in Example 1 to obtain a cured film. When the obtained cured coating film was evaluated under the same conditions as in Example 1, the results shown in Table 4 were obtained.

[0054]

[Table 4]

[Example 5] The photopolymerization initiator in the amounts shown in Table 5 was added to 100 parts by weight of the total amount of the curable composition and the acrylic copolymer used in 4-of Example 4, and A coating composition was obtained in the same manner as in Example 1 except that 10 parts of TYN was added as an ultraviolet absorber. Using the obtained composition, a cured coating film was formed under the same conditions as in Example 4 and evaluated. As a result, good results as shown in Table 5 were obtained.

[0056]

[Table 5]

Example 6 With respect to 100 parts by weight of the total amount of the curable composition and the acrylic copolymer used in 4-of Example 4, Lucillin TPO 0.2 as a photopolymerization initiator was used.
A coating composition was obtained in the same manner as in Example 1 except that the amount of the ultraviolet absorber shown in Table 6 was added. Using the obtained composition, a cured coating film was formed under the same conditions as in Example 4 and evaluated. As a result, good results as shown in Table 6 were obtained.

[0058]

[Table 6]

[Example 7] (e-1) 1 was used as a matting agent in a solution obtained by stirring and mixing the curable composition used in Example 1.
A cured film was formed in the same manner as in Example 1 except that 5 parts were added, stirred, and uniformly dispersed to obtain a coating composition. The cured film was evaluated, and a good evaluation as shown in Table 7 below was obtained. Results were obtained.

[0060]

[Table 7]

[Example 8] Except for adding 100 parts by weight of the curable composition used in 1-of Example 1, 10 parts by weight of TYN as a UV absorber and a photopolymerization initiator in the amounts shown in Table 8 were added. In the same manner as in Example 1, 15 parts of (e-1) was added as a matting agent to the solution obtained by stirring and mixing, and the mixture was stirred and uniformly dispersed to prepare a coating composition. Using the obtained composition, a cured coating film was formed under the same conditions as in Example 1 and evaluated. As a result, good results as shown in Table 8 were obtained.

[0062]

[Table 8]

Example 9 The same as Example 1 except that the amount of TYN shown in Table 9 was used as an ultraviolet absorber for 100 parts by weight of the curable composition used in 1-of Example 1. Matting agent (e-1) 1 was added to the solution obtained by stirring and mixing.
5 parts were added and stirred to obtain a uniformly dispersed coating composition. When a cured coating was formed on the obtained composition under the same conditions as in Example 1 and this evaluation was carried out, good results were obtained as shown in Table 9.

[Table 9]

[Example 10] With respect to 100 parts by weight of the curable composition used in 1-of Example 1, 2 parts of TPO was used as a photopolymerization initiator and 10 parts of TYN was used as an ultraviolet absorber. To the solution obtained by stirring and mixing in the same manner as in Example 1, (e-1) as a matting agent was added in an amount shown in Table 10 and stirred to obtain a uniformly dispersed coating composition. When a cured coating was formed on the obtained composition under the same conditions as in Example 1 and this evaluation was carried out, good results were obtained as shown in Table 10.

[0065]

[Table 10]

[Example 11] To the solution obtained by stirring and mixing in Example 4, 15 parts of (e-1) as a matting agent was added and mixed by stirring to obtain a uniformly dispersed coating composition. . Using this composition, a cured film was formed in the same manner as in Example 1 and evaluated. As a result, good results as shown in Table 11 were obtained.

[0067]

[Table 11]

Example 12 Example 1 was repeated except that the amount of the photopolymerization initiator shown in Table 12 and 10 parts of TYN as an ultraviolet absorber were added to the solution obtained by stirring and mixing in 4-of Example 4. (E-1) was added as a matting agent to the solution obtained by stirring and uniformly mixing in the same manner as in (1) to stir to obtain a uniformly dispersed coating composition. Using this composition, a cured film was formed in the same manner as in Example 4 and evaluated.
Good results as shown in Table 12 were obtained.

[0069]

[Table 12]

[Example 13] Example 1 was repeated except that 2 parts of TPO as a photopolymerization initiator and the amount of the ultraviolet absorber shown in Table 13 were added to the solution obtained by stirring and mixing in 4-of Example 4. (E-1) as a matting agent was mixed with the solution obtained by stirring and mixing in the same manner as in (1) to obtain a coating composition in which the coating composition was uniformly dispersed. Using this composition, a cured film was formed in the same manner as in Example 4 and evaluated. As a result, good results as shown in Table 13 were obtained.

[0071]

[Table 13]

Example 14 The same procedure as in Example 7 was carried out except that 2 parts of TPO as a photopolymerization initiator and 10 parts of TYN as an ultraviolet absorber were added to the solution obtained by stirring and mixing in 1-of Example 1. A matting agent was added to the mixed solution obtained in Table 14.
The amount shown in (1) was added, and the mixture was stirred and uniformly dispersed to obtain a coating composition. Using this composition, a cured film was formed in the same manner as in Example 4 and evaluated. As a result, good results as shown in Table 14 were obtained.

[0073]

[Table 14]

[Comparative Example 1] A curable composition comprising DP6A and THFA in the amounts shown in Table 15 and T as an ultraviolet absorber.
YN, TPO as an acylphosphine oxide-based photopolymerization initiator, and 1 as a photopolymerization initiator other than the initiator.
-Hydroxycyclohexyl phenyl ketone (manufactured by Nippon Ciba Geigy; trade name: Irgacure 184);
Hydroxy-2-methyl-1-phenyl-propane-1
A coating composition was prepared in the same manner as in Example 1 except that -one was added. Using the obtained composition, a cured coating film was obtained and evaluated in the same manner as in Example 1. The results are shown in Table 15 below.
The results shown in are obtained.

[0075]

[Table 15] (* 1): 1-hydroxycyclohexyl phenyl ketone (manufactured by Nippon Ciba Geigy; trade name: Irgacure-1)
84) (* 2): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Merck; trade name: Darocur-1173)

As can be seen from the above results, the compounding amount of the polyfunctional monomer having 3 or more (meth) acryloyloxy groups in one molecule, which is the component (a) of the present invention, is 10 or less.
Although the coating composition having less than the parts can obtain a cured coating having good adhesion, appearance, and UV absorption, the degree of crosslinking of the composition becomes too small and the curability decreases, resulting in hardness and solvent resistance. It becomes a cured film with low property. On the contrary, the coating composition containing the component (a) of the present invention in an amount of more than 90 parts can give a cured coating having good hardness, solvent resistance, appearance and ultraviolet absorption, but has a crosslinking degree. Since it becomes too high, the cured film has reduced adhesion.

A coating composition containing an ultraviolet absorber in an amount of less than 2 parts has good adhesion, hardness, solvent resistance and appearance, but a cured film having poor ultraviolet absorption.
Conversely, for coating compositions with more than 30 parts UV absorber,
Although a cured coating having good adhesiveness and ultraviolet absorptivity can be obtained, since a large amount of ultraviolet energy necessary for curing the composition is lost to the ultraviolet absorber, curability, hardness, and solvent resistance are reduced, The physical properties are poor such that the cured film turns yellow.

When a coating composition containing a photopolymerization initiator in an amount of less than 0.5 part is used, a cured coating having good adhesion, appearance and ultraviolet absorption can be obtained, but the curability of the composition is high. As a result, the hardness and solvent resistance of the cured film become poor. On the other hand, when a coating composition containing the photopolymerization initiator in an amount of more than 20 parts is used, a cured film having good hardness and ultraviolet absorptivity can be obtained, but the curability of the composition becomes too high. , Physical properties such as yellowing, adhesion, and deterioration of appearance are poor. The coating composition in which the photopolymerization initiator is replaced with a photopolymerization initiator other than the acylphosphine oxide-based photopolymerization initiator becomes a cured film with reduced curability, hardness and solvent resistance.

[Comparative Example 2] Except that a curable composition comprising DP6A and THFA in an amount shown in Table 16 and a resin component comprising an acrylic copolymer, TYN as an ultraviolet absorber and a photopolymerization initiator were added. A coating composition was obtained in the same manner as in Example 1. Using the obtained composition, a cured film was obtained and evaluated in the same manner as in Example 4, and the results shown in Table 16 were obtained.

[0080]

[Table 16] (* 1): 1-hydroxycyclohexyl phenyl ketone (manufactured by Nippon Ciba Geigy; trade name: Irgacure-1)
84) (* 2): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Merck; trade name: Darocur-1173)

As can be seen from the above results, when the coating composition containing the acrylic copolymer which is the component (II) of the present invention in an amount of more than 60 parts is used, the adhesiveness, the appearance and the ultraviolet absorption are improved. Although a cured film having good properties is obtained, the degree of cross-linking of the composition is lowered, so that the cured film has poor curability, hardness, and solvent resistance. On the contrary, in the case of the coating composition containing less than 5 parts of the acrylic copolymer, the cured film has poor adhesion to the poorly adherent material.

When a coating composition containing less than 2 parts of the ultraviolet absorber is used, a cured film having good hardness, solvent resistance and appearance but poor ultraviolet absorption is obtained. On the contrary, in the case of a coating composition containing more than 30 parts of the ultraviolet absorber, the adhesiveness and the ultraviolet absorptivity are good, but a large amount of the ultraviolet energy necessary for curing the composition is lost. Therefore, the curability is reduced, and the cured film has poor physical properties such as a decrease in hardness and solvent resistance and yellowing.

When a coating composition containing less than 0.5 parts of a photopolymerization initiator is used, the adhesiveness, appearance and ultraviolet absorption are good, but the physical properties such as curability, hardness and solvent resistance are poor. It becomes a cured film. On the contrary, when a coating composition having a content of the photopolymerization initiator of more than 20 parts is used, a cured coating having good hardness and ultraviolet absorptivity can be obtained, but since the curability becomes too high, yellowing occurs. The cured film has poor adhesion and appearance.

The coating composition using a photopolymerization initiator other than the acylphosphine oxide type photopolymerization initiator which is the component (c) of the present invention is a cured film having poor curability, hardness and solvent resistance. .

[Comparative Example 3] A curable composition comprising DP6A and THFA in the amounts shown in Table 17, an ultraviolet absorber, an acylphosphine oxide-based photopolymerization initiator, rusilin TPO, and a photopolymerization initiator other than the initiator. As 1-hydroxycyclohexyl phenyl ketone (manufactured by Japan Ciba-Geigy; trade name: Irgacure-184), and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Merck; trade name: Darocur-1173). ) And a matting agent (e-1) were added to obtain a coating composition in the same manner as in Example 7. Example 1 using the obtained composition
When a cured film was formed in the same manner as in Example 1 and evaluated in the same manner as in Example 10, the results shown in Table 17 were obtained.

[0086]

[Table 17] (* 1): 1-hydroxycyclohexyl phenyl ketone (manufactured by Nippon Ciba Geigy; trade name: Irgacure-1)
84) (* 2): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Merck; trade name: Darocur-1173)

From the above results, a coating containing less than 10 parts of the compounding amount of the polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule which is the component (a) of the present invention. When the composition is used, the adhesiveness, the appearance and the ultraviolet absorptivity are good, but the degree of crosslinking becomes too small, the curability is lowered, and a cured film having poor hardness and solvent resistance is obtained. On the contrary, when a coating composition containing DP6A in an amount of more than 90 parts is used, the hardness, solvent resistance, appearance and ultraviolet absorption are good, but the degree of crosslinking of the composition is too high, and therefore the adhesion is high. The resulting cured film has poor properties.

Use of a coating composition containing an ultraviolet absorber in an amount of less than 2 parts results in a cured film having good adhesion, hardness, solvent resistance, and appearance, but poor ultraviolet absorption. On the contrary, a coating composition containing an ultraviolet absorber in an amount of more than 30 parts has good adhesiveness and ultraviolet absorptivity, but a large amount of ultraviolet energy required for curing is lost, resulting in a decrease in curability. However, the cured film has poor physical properties such as hardness, solvent resistance, and yellowing.

The coating composition prepared by incorporating the photopolymerization initiator as the component (c) of the present invention in an amount of less than 0.5 part has good adhesiveness, appearance and ultraviolet absorptivity, but curability. Is poor, the cured film has poor hardness and solvent resistance. On the contrary, the coating composition containing the component (c) in an amount of more than 20 parts has good hardness and ultraviolet absorptivity, but the curability of the composition becomes too high. Since yellowing occurs, the cured film has poor adhesion and appearance.

The coating composition in which the photopolymerization initiator is replaced with a photopolymerization initiator other than the component (c) of the present invention has a reduced curability and a cured coating with reduced hardness and solvent resistance. With a coating composition containing less than 1 part of the matting agent, the physical properties of the present invention such as the physical properties of the cured film obtained and the ultraviolet absorbing property, and a cured film having a good ultraviolet absorbing property can be obtained, but it is good. A cured coating having a matt feeling cannot be obtained.

Further, in the case of a coating composition containing more than 20 parts of the matting agent, a whitening phenomenon with a bad matte feeling occurs, or a cured film having reduced hardness and solvent resistance due to deterioration of curability. Becomes

[Comparative Example 4] A curable composition consisting of DP6A and THFA in the amounts shown in Table 18, an acrylic copolymer,
TYN as an ultraviolet absorber, Lucillin TPO as an acylphosphine oxide-based photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator other than the initiator (manufactured by Japan Ciba-Geigy; trade name: Irgacure-184), and 2-Hydroxy-2-methyl-1-phenyl-propan-1-one (Merck & Co .; trade name: Darocur-1173), the same as in Example 7 except that the matting agent (e-1) was added. A coating composition was obtained.
A cured film was formed using the obtained composition in the same manner as in Example 4 and evaluated in the same manner as in Example 1. The results shown in Table 18 were obtained.

[0093]

[Table 18] (* 1): 1-hydroxycyclohexyl phenyl ketone (manufactured by Nippon Ciba Geigy; trade name: Irgacure-1)
84) (* 2): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by Merck; trade name: Darocur-1173)

From the above results, when the coating composition containing more than 60 parts of the acrylic copolymer as the component (II) of the present invention is used, the adhesiveness, the appearance and the ultraviolet absorptivity are good. However, the degree of crosslinking of the composition becomes too small, the curability is lowered, and a cured film having poor hardness and solvent resistance is obtained. On the other hand, when a coating composition containing less than 5 parts of the acrylic copolymer is used, the cured film has poor adhesion to a substrate having poor adhesion such as polyolefin resin.

When a coating composition containing less than 0.5 part of the photopolymerization initiator as the component (c) of the present invention is used, the adhesiveness, the appearance and the ultraviolet absorptivity are good, but the composition is The curability of the product becomes poor, and the cured film has poor hardness and solvent resistance. On the contrary, the coating composition containing the component (c) in an amount of more than 20 parts has good hardness and ultraviolet absorptivity, but the curability of the composition becomes too high. Since yellowing occurs, the cured film has poor adhesion and appearance.

By using a coating composition containing more than 30 parts of the ultraviolet absorber as the component (d) of the present invention, it is possible to obtain a cured coating having good adhesion to a substrate and ultraviolet absorptivity. However, since a large amount of ultraviolet energy required for curing the composition by irradiation with ultraviolet rays is lost, curability is lowered, and the cured film has poor physical properties such as poor hardness and solvent resistance and yellowing. Become. On the contrary, when a coating composition containing less than 5 parts of the ultraviolet absorber is used, a cured coating having good adhesion, hardness, solvent resistance and appearance can be obtained, but the ultraviolet absorption is poor. It becomes a cured film.

With a coating composition containing less than 1 part of the matting agent as the component (e) of the present invention, a cured coating having the desired physical properties of the cured coating and good ultraviolet absorption can be obtained. However, a cured coating having a good matte feeling cannot be obtained. Further, in the case of a coating composition containing more than 20 parts of the matting agent, a whitening phenomenon with a bad matt feeling occurs, or a cured film with reduced hardness and solvent resistance due to reduced curability.

Table 19 shows the evaluation results of the hot stamping property and the printability in Examples 1 to 14 and Comparative Examples 1 to 4 thus performed.

[0099]

[Table 19]

[0100]

As described above, the coating composition of the present invention comprises a combination of a specific photopolymerization initiator, an ultraviolet absorber, and specific components, has an ultraviolet blocking property, and has a printing property. It is possible to form a cured coating film having good stamping property and stampability, and it is possible to provide a container excellent in designability with high productivity and at low cost. Further, the container obtained by applying and curing the coating composition of the present invention has excellent ultraviolet ray blocking properties, and thus is easily altered by ultraviolet rays, such as raw materials, foods, pharmaceuticals, cosmetics, alcoholic beverages, contents and / or container bases. It can be used in all fields where the material itself should be protected from ultraviolet rays, and has a great industrial utility value.

Claims (6)

[Claims] 1. (a) 10 to 90% by weight of a polyfunctional monomer having three or more (meth) acryloyloxy groups in one molecule, and (b) one or two (meth) in one molecule. A curable composition (I) containing 90 to 10% by weight of a bifunctional monomer having an acryloyloxy group, and the component (I) 10.
At least 1 of 0.5 to 20 parts by weight with respect to 0 parts by weight
One or more acylphosphine oxide compounds (c)
And a UV absorber (d) in an amount of 2 to 30 parts by weight, a coating composition for a container. 2. (a) 10 to 90% by weight of a polyfunctional monomer having three or more (meth) acryloyloxy groups in one molecule, and (b) one or two (meth) in one molecule. Curable composition (I) 40-95% by weight, containing 1 to 2 functional monomer having acryloyloxy group 90 to 10% by weight, acrylic copolymer (II) 60 to 5% by weight, Based on 100 parts by weight of the total amount of the component (I) and the component (II),
(C) UV blocking property containing 0.5 to 20 parts by weight of a photopolymerization initiator composed of at least one or more acylphosphine oxide compounds, and (d) 2 to 30 parts by weight of an ultraviolet absorber. A coating composition for a container capable of forming a cured coating having: 3. A curable composition (I) containing 1 to 20 parts by weight of a matting agent with respect to 100 parts by weight of the curable composition (I).
A coating composition for a container according to the above. 4. A matting agent of 1 to 20 parts by weight per 100 parts by weight of the total amount of the curable composition (I) and the acrylic copolymer (II) is contained. A coating composition for a container. 5. A container having a cured coating of the coating composition according to claim 1, claim 2, claim 3, or claim 4. 6. The container according to claim 5, which has a cured coating that blocks ultraviolet rays having a wavelength of 400 nm or less.