JP6658184B2 - UV curable coating composition and laminate - Google Patents

Description

The present invention relates to an ultraviolet-curable coating composition and a laminate obtained by applying and curing the composition on a paper substrate having a printing ink layer. More specifically, the present invention relates to an ultraviolet-curable coating agent composition capable of forming a cured film having both abrasion resistance and post-processing suitability (resistance to cracking at bending, recoating property, and slipperiness).

Active energy ray-curable coating varnishes are practically almost solvent-free and have the advantage that curing can be completed by irradiating active energy rays for a very short time without a heat drying step. Widely used in the field of package printing for printing. Improves abrasion resistance, abrasion resistance, blocking resistance and protects the printed surface, and at the same time, imparts gloss or matte feeling, and is applied to printed matter for upgrading and cosmetics, but the package surface including inclusions In some cases, scratches are caused by the rubbing of the packages or the impact of collision during the transportation of the goods, and depending on the shape and material of the packages and the weight and hardness of the inclusions, the damages may be generated to the extent that the commercial value is impaired. However, when the crosslink density is increased to improve the friction resistance and abrasion resistance, the flexibility decreases and the material becomes brittle. There is a problem that cracks easily occur.

As an active energy ray-curable resin composition having excellent friction resistance and resistance to cracking during bending, an active energy ray-curable compound having three or more (meth) acryloyl groups and having a polyalkyleneoxy group, By adjusting the pentaerythritol derivative having three or more (meth) acryloyl groups and the active energy ray-curable compound having six or more (meth) acryloyl groups at a predetermined ratio, a suitable scratch resistance and An active energy ray-curable composition (Patent Document 1) capable of obtaining a cured coating film having both flexibility and a ratio of an acryloyl group or a methacryloyl group contained in a resin composition and a compound having a polyalkyleneoxy in a predetermined ratio A resin composition capable of adjusting a resin cured product having both appropriate hardness and flexibility by adjusting the viscosity (Patent Document 2) (Meth) acrylate obtained by adding 1 to 20 mol of alkylene oxide having 2 to 4 carbon atoms to (meth) acrylate having one hydroxyl group and three or more (meth) acryloyl groups in a molecule, and polyisocyanate An active energy ray that has a self-healing property and is capable of obtaining a coating film with less curing shrinkage by adjusting a urethane (meth) acrylate obtained by reacting the compound with a polyfunctional (meth) acrylate at a predetermined ratio. A curable composition (Patent Document 3) and the like have been proposed.

However, in the technique described in Patent Document 1, the bending resistance of the obtained coating film is evaluated by a cylindrical mandrel method, and when the mandrel diameter is about 3 mm, the coating film cracks and the flexibility is not sufficient. On the other hand, Patent Literature 2 discloses a resin composition for producing an optical component, which is excellent in hardness and pressure resistance and can adjust a fine uneven structure having flexibility. However, the friction resistance of the cured film is about 100 g in a friction test using steel wool, and more excellent friction resistance is required. Further, in the technique of Patent Document 3, since the viscosity of urethane acrylate is high, it is difficult to reduce the viscosity so that it can be used in various printers without a solvent.

JP 2013-163765 A JP-A-2009-286953 JP 2012-180487 A

Therefore, the present invention provides an ultraviolet-curable coating agent composition for a paper substrate and a transparent film substrate, which is capable of forming a cured coating film having excellent bending resistance, curability, impact resistance, friction resistance and fingerprint resistance. The purpose is to provide.

As a result of intensive studies on the above problem, the present inventors have found that the problem can be solved by using the following ultraviolet-curable coating agent composition, and have reached the present invention.

The present invention provides an ultraviolet-curable coating agent composition that does not use a solvent and is used for a paper substrate having a printing ink layer at least in part, and is characterized by the following (1) and (2). I do.
In a total amount of 100% by weight of the ultraviolet curable compound in the coating agent composition,
20 to 70% by weight of a trifunctional or higher acrylate compound (A) having an addition alkylene oxide mole number of 4 to 20;
The urethane acrylate compound (B) which is a reaction product of the aliphatic and / or alicyclic diisocyanate compound (b1) and the compound (b2) having one hydroxyl group and two or more (meth) acrylate groups is 0 to 45 weight%,
It contains 10 to 50% by weight of a trifunctional or higher acrylate compound (C) having no alkyleneoxy group.
(However, (A) and (C) exclude the case of (B).)
(2) It contains a benzophenone-based photopolymerization initiator (D).

The present invention also provides the above-mentioned ultraviolet ray, wherein the glass transition temperature of the acrylate compound (A) after curing is −40 to 10 ° C., and the glass transition temperature of the acrylate compound (C) after curing is 100 ° C. or more. The present invention relates to a curable coating composition.

Further, in the present invention, the acrylate compound (A) is an ethylene oxide and / or propylene oxide addition acrylate of at least one compound selected from the group consisting of pentaerythritol, dipentaerythritol, trimethylolpropane, and glycerin. The present invention relates to the ultraviolet-curable coating composition.

The present invention also relates to the ultraviolet-curable coating agent composition, wherein the acrylate compound (A) is an acrylate added with ethylene oxide and / or propylene oxide of trimethylolpropane.

Further, in the present invention, the compound (b2) may be selected from the group consisting of pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane di (meth) acrylate, and glyceryl di (meth) acrylate. The ultraviolet-curable coating agent composition is at least one selected from the group.

The present invention also relates to the ultraviolet-curable coating composition, further comprising a hydrogenated oil (E).

The present invention also relates to the ultraviolet-curable coating composition, further comprising resin fine particles (F) having an average particle size of 1.0 to 10.0 μm.

The present invention also relates to a laminate having a coating layer formed from the ultraviolet-curable coating composition on a paper substrate having a printing ink layer at least in part.

An ultraviolet-curable coating agent composition having excellent bending resistance and capable of forming a cured coating film having curability, impact resistance, rub resistance and fingerprint resistance was provided.

Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited thereto unless it exceeds the gist thereof. The content is not limited.

The present invention provides an ultraviolet-curable coating agent composition that does not use a solvent and is used for a paper substrate having a printing ink layer at least in part, and is characterized by the following (1) and (2). I do.
In a total amount of 100% by weight of the ultraviolet curable compound in the coating agent composition,
20 to 70% by weight of a trifunctional or higher acrylate compound (A) having an addition alkylene oxide mole number of 4 to 20;
The urethane acrylate compound (B) which is a reaction product of the aliphatic and / or alicyclic diisocyanate compound (b1) and the compound (b2) having one hydroxyl group and two or more (meth) acrylate groups is 0 to 45 weight%,
It contains 10 to 50% by weight of a trifunctional or higher acrylate compound (C) having no alkyleneoxy group.
(However, (A) and (C) exclude the case of (B).)
(2) It contains a benzophenone-based photopolymerization initiator (D).

The UV-curable coating agent composition of the present invention contains the acrylate compound (A), urethane acrylate compound (B) and acrylate compound (C) as main components and a benzophenone-based photopolymerization initiator (D) as an essential component. . In the cured coating film, the acrylate compound (A) is responsible for the flexibility of the coating film, the urethane acrylate compound (B) is responsible for the flexibility of the coating film, and the acrylate compound (C) is responsible for the hardness of the cured coating film. When (A) is 20 to 70% by weight, (B) is 0 to 45% by weight and (C) is 10 to 50% by weight in 100% by weight, bending resistance, impact resistance and friction resistance are improved. To achieve. (A) / (B) / (C) is preferably 20 to 70% / 10 to 45% / 10 to 50% (% by weight), more preferably 30 to 60% / 20 to 45% / 15 to 15%. 45% (% by weight).

If (A) is less than 20% by weight in the total amount of the ultraviolet curable compound of 100% by weight, the cured coating film is too hard and the bending resistance is reduced. If it exceeds 70% by weight, the cured coating film is too soft and rub-resistant. Is reduced. If the urethane acrylate compound (B) exceeds 45% by weight, the cured coating film cannot have both bending resistance and friction resistance. When the acrylate compound (C) is less than 10% by weight, the abrasion resistance of the cured coating film decreases, and when it exceeds 50% by weight, the bending resistance of the cured coating film decreases. When a photopolymerization initiator other than the benzophenone-based photopolymerization initiator (D) is used, the curability and the friction resistance of the cured coating film are poor.

The total of (A), (B) and (C) in the total amount of the ultraviolet curable compound of 100% by weight is not particularly limited as long as the problem of the present application can be solved, but is preferably 80% or more, more preferably 90% or more. % Or more.

In the present specification, the glass transition temperature (hereinafter, sometimes referred to as Tg) refers to an endothermic curve near the glass transition temperature measured by a differential scanning calorimeter (DSC) at a heating temperature of 10 ° C./min. Indicates the temperature at the midpoint of the tangent.

<Acrylate compound (A)>
The acrylate compound (A) is a trifunctional or higher acrylate compound (A) having an addition mole number of the alkylene oxide of 4 to 20, and has a glass transition temperature of −40 ° C. after being cured by ultraviolet light or electron beam irradiation. The temperature is preferably from 10 to 10 ° C. The alkyleneoxy group significantly reduces the Tg after curing the acrylate compound (A). When the Tg of the acrylate compound (A) is within the above range, the cured film made of the ultraviolet-curable coating composition has excellent flexibility, bending resistance, and friction resistance. The Tg of the acrylate compound (A) is more preferably -35 ° C to 0 ° C.

Examples of the alkyleneoxy group include an ethyleneoxy group, a propyleneoxy group, a trimethyleneoxy group, and a tetramethyleneoxy group, and these may be arbitrarily combined. It is preferably an ethyleneoxy group or a propyleneoxy group, and the number of moles added is preferably from 6 to 15. When the molecular weight of the acrylate compound (A) increases due to the increase in the number of moles added, the penetration of the ultraviolet-curable coating composition into the paper substrate decreases. Further, as described later, when the addition amount of the alkylene oxide is within the above range, the curability and physical properties are specifically improved when the benzophenone-based photopolymerization initiator (D) is used.

In this specification, the number of moles of addition refers to the number of moles of an alkylene oxide group added to 1 mole of a basic structure (pentaerythritol, trimethylolpropane, etc. described below), for example, ethylene oxide having 9 moles of addition. In addition trimethylolpropane triacrylate, 9 mol of ethylene oxide is added to 1 mol of trimethylolpropane. Therefore, since trimethylolpropane has three hydroxyl groups, when the three hydroxyl groups and ethylene oxide have the same reactivity, a structure in which an ethyleneoxy group is added with an average addition number of 3 mol is obtained.

In the following description, (meth) acryl or (meth) acrylate means methacryl and acryl, methacrylate and acrylate, respectively.

As the acrylate compound (A) having a glass transition temperature of −40 ° C. to 10 ° C.,
Ethylene oxide added trimethylolpropane tri (meth) acrylate (n = 6), ethylene oxide added trimethylolpropane tri (meth) acrylate (n = 9), ethylene oxide added trimethylolpropane tri (meth) acrylate (n = 15) , Ethylene oxide-added trimethylolpropane tri (meth) acrylate (n = 20),
Ethylene oxide added pentaerythritol tri / tetra (meth) acrylate (n = 6), ethylene oxide added pentaerythritol tri / tetra (meth) acrylate (n = 9), ethylene oxide added pentaerythritol tri / tetra (Meth) acrylate (n = 15), ethylene oxide-added pentaerythritol tri / tetra (meth) acrylate (n = 20),
Ethylene oxide-added dipentaerythritol penta / hexa (meth) acrylate (n = 6), ethylene oxide-added dipentaerythritol penta / hexa (meth) acrylate (n = 9), ethylene oxide-added dipentaerythritol Penta / hexa (meth) acrylate (n = 15), ethylene oxide-added dipentaerythritol penta / hexa (meth) acrylate (n = 20),
Ethylene oxide added glycerin tri (meth) acrylate (n = 6), ethylene oxide added glycerin tri (meth) acrylate (n = 9), ethylene oxide added glycerin tri (meth) acrylate (n = 12), ethylene oxide added glycerin tri (Meth) acrylate (n = 18), ethylene oxide-added glycerin tri (meth) acrylate (n = 20),
Propylene oxide-added trimethylolpropane tri (meth) acrylate (n = 6), propylene oxide-added trimethylolpropane tri (meth) acrylate (n = 9), propylene oxide-added trimethylolpropane tri (meth) acrylate (n = 15) ,
Ethylene oxide-added isocyanuric acid tri (meth) acrylate (n = 6),
Propylene oxide-added pentaerythritol tetra (meth) acrylate (n = 9), propylene oxide-added dipentaerythritol hexa (meth) acrylate (n = 12),
Propylene oxide-added pentaerythritol tetra (meth) acrylate (n = 4), propoxylated dipentaerythritol hexa (meth) acrylate (n = 12), and the like.
In addition, "/" in the notation of the above compound means or, and parentheses indicate the number of added moles of the alkylene oxide contained in the compound. For example, “(n = 3)” means that the added mole number of the alkylene oxide contained in the compound is 3. Among these, those having a molecular weight of 500 to 2,000 are preferable because the penetration into the paper substrate is suppressed. Among them, the trimethylolpropane-based, pentaerythritol-based, and dipentaerythritol-based basic structures are preferred in terms of the glass transition temperature and the molecular weight. And glycerin-based alkylene oxides of ethylene oxide and propylene oxide are preferable, and ethylene oxide-added trimethylolpropane tri (meth) acrylate is most preferable.

<Urethane acrylate compound (B)>
The urethane acrylate compound (B) is a reaction product of an aliphatic and / or alicyclic diisocyanate compound (b1) and a compound (b2) having one hydroxyl group and two or more (meth) acrylate groups. The urethane acrylate compound (B) needs to have two or more (meth) acrylate groups in order to increase the cross-linking density and exhibit hardness, and at the same time, it is necessary to impart flexibility. is necessary. When the diisocyanate compound (b1) is other than an aliphatic and / or alicyclic compound, that is, an aromatic compound is not preferable because there is a fear of yellowing.

The aliphatic and / or alicyclic diisocyanate compound (b1) includes, for example, butane-1,4-diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isopropylene diisocyanate, ethylene diisocyanate as an aliphatic diisocyanate. , 2,4-trimethylhexamethylene diisocyanate, and the like.
Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, and hydrogenation. Xylylene diisocyanate, hydrogenated m-tetramethyl xylylene diisocyanate, and the like.
Preferred are hexamethylene diisocyanate and isophorone diisocyanate, which may be trimerized and have an isocyanurate ring, or may be, for example, an adduct of trimethylolpropane.

Examples of the diisocyanate trimer having an isocyanurate ring include, for example, isocyanurate-modified isophorone diisocyanate (for example, Desmodur Z4470 manufactured by Sumika Bayer Urethane Co., Ltd.) and isocyanurate-modified hexamethylene diisocyanate (for example, Sumika Sumidur N3300 manufactured by Bayer Urethane Co., Ltd., and duranate TPA-100 and MFX-90X manufactured by Asahi Kasei Kogyo Co., Ltd.). As the adduct of trimethylolpropane, trimethylolpropane adduct hexamethylene diisocyanate (for example, Sumika Bayer) And Sumidur HT manufactured by Urethane Co., Ltd., and Duranate P-301-75E manufactured by Asahi Kasei Corporation.

Examples of the compound (b2) having one hydroxyl group and two or more (meth) acrylate groups include pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropanedi (meth) acrylate, and glyceryldi (Meth) acrylate and the like.
The product industrially available as "pentaerythritol tri (meth) acrylate" may be a mixture of pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate. When such a mixture is used, pentaerythritol tetra (meth) acrylate does not have a hydroxyl group and does not react with the diisocyanate compound (b1), but pentaerythritol tetra (meth) acrylate is coated as an acrylate compound (C) described later. May be included in the agent composition. The urethane acrylate compound (B) is preferably a reactant having a hydroxyl group / isocyanate group of 1 to 1.2, and preferably has no isocyanate group.

Examples of the method for producing the urethane acrylate compound (B) include, for example, an aliphatic and / or alicyclic diisocyanate compound (b1) and a compound (b2) having one hydroxyl group and two or more (meth) acrylate groups. And isocyanate group: hydroxyl group = 1: 1 in the presence of a polymerization terminator in an oxygen atmosphere for 3 to 6 hours. The preferred weight average molecular weight of the urethane acrylate compound (B) is from 500 to 2,000.

<Acrylate compound (C)>
The acrylate compound (C) needs to have three or more acrylate groups in the molecule to play a role of imparting hardness in the UV-curable coating composition of the present invention, and the glass transition after UV or electron beam curing. Preferably, the temperature is at least 100 ° C. When the Tg is 100 ° C. or higher, the friction resistance is excellent. Preferably it is 200 ° C. or higher.

Among the acrylate compounds (C), those having a Tg of 100 ° C. or higher include, for example, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, glyceryl tri (meth) acrylate Acrylate, ditrimethylolpropanetetra (meth) acrylate, diglyceryltetra (meth) acrylate and the like can be mentioned. Among them, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate are preferred.

<Benzophenone-based photopolymerization initiator (D)>
The ultraviolet-curable coating agent composition of the present invention essentially contains a benzophenone-based photopolymerization initiator (D). It is not particularly limited as long as it has a benzophenone structure and the polymerization reaction proceeds by generating a radical by hydrogen abstraction. Preferred examples thereof include benzophenone, 4-methylbenzophenone, and 4,4′-bis (dimethylamino). Benzophenone, 4,4'-bis (diethylamino) benzophenone, methyl-o-benzoylbenzoate, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3, 3-dimethyl-4-methoxybenzophenone and the like. Among them, 4-methylbenzophenone is preferable.

The benzophenone-based photopolymerization initiator (D) is an initiator in which radicals are generated by hydrogen abstraction and a polymerization reaction proceeds, and the acrylate compound (A) having an alkyleneoxy group and the benzophenone-based photopolymerization initiator (D) ), The benzophenone-based photopolymerization initiator (D) withdraws hydrogen derived from the alkyleneoxy group by ultraviolet irradiation, and the curing reaction proceeds, so that the curing speed is improved as compared with the case where there is no alkyleneoxy group. It is thought to be. This effect becomes more remarkable as the number of added alkyleneoxy groups increases. At the same time, the ultraviolet curable coating agent composition of the present invention has various physical properties such as bending resistance, friction resistance, and impact resistance in the coating film after ultraviolet curing by using the benzophenone-based photopolymerization initiator (D). There is an effect of improving, and these effects cannot be obtained when another photopolymerization initiator is used. In addition, since the curing speed is further increased in combination with an amine photosensitizer described later, it is more preferable to use an amine photosensitizer in combination with the benzophenone photopolymerization initiator (D).

The benzophenone-based photopolymerization initiator (D) is preferably contained in an amount of 1% to 20%, more preferably 5% to 15%, based on 100% by weight of the ultraviolet curable coating composition.

In the ultraviolet-curable coating agent composition of the present invention, a photopolymerization initiator other than the benzophenone-based photopolymerization initiator (D) may be used in combination, if necessary, as long as the above effects are not impaired.

Examples of the photopolymerization initiator include, for example, acetophenone-based photopolymerization initiators such as 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4 -Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2,2-dimethoxy-2-phenylacetophenone and the like.

Examples of the alkylphenone-based photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 2-hydroxy-2-methyl-1-phenyl-propane. -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2 -Hydroxy-2-methyl-propionyl) -benzyl] phenyl {-2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl]- - [4- (4-morpholinyl) phenyl] -1-butanone, and the like.

Examples of the benzoin-based photopolymerization initiator include benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, and 2,4-diisopropyl Thioxanthone and the like.

Examples of the anthraquinone-based photopolymerization initiator include α-acyloxime ester, benzyl, methylbenzoyl formate (“VIACURE 55”), 2-ethylanthraquinone, and the like.

Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide (“luciline TPO”) and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (“IRGACURE819”). Is mentioned.

(Photosensitizer)
Further, in the ultraviolet-curable coating agent composition of the present invention, it is preferable to use an amine-based photosensitizer as the photosensitizer. The amine-based photosensitizer promotes the hydrogen abstraction reaction of the benzophenone-based photopolymerization initiator (D) and improves the curing reaction rate. Specific examples of the amine photosensitizer include, for example, aliphatic amines such as trimethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, aniline, N-methylaniline, and N, N-dimethyl. Examples include aromatic amines such as aniline, amine (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and acryloylmorpholine, amine-based polyester acrylates, and amine-based acrylate oligomers. Among these, N-methyldiethanolamine is preferably used because it has particularly good compatibility with the composition of the present invention and photosensitivity. The amine photosensitizer is preferably used in the range of 0.1 to 20% by weight, more preferably in the range of 1 to 5% by weight, based on 100% by weight of the total of the photocurable composition.

Further, the ultraviolet-curable coating agent composition of the present invention may contain a sensitizer other than the amine-based photosensitizer, for example, biphenyl, 1,4-dimethylnaphthalene, 9-fluorenone, fluorene, phenanthrene. , Triphenylene, anthracene, 9,10-diphenylanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, benzophenone, 4,4′- Dimethoxybenzophenone, acetophenone, 4-methoxyacetophenone, benzaldehyde and the like can be used.

<Hydrogenated fats and oils (E)>
The ultraviolet-curable coating composition of the present invention preferably contains a hydrogenated oil (E). The oil (E) has the effect of applying a coating agent and being cured by ultraviolet light, and then orienting on the surface of the coating film, thereby exhibiting a fingerprint resistance function. Hydrogenated fats and oils are preferred because double bonds derived from unsaturated fatty acids do not exist and do not affect the crosslink density of the coating composition. Fats and oils have different fatty acid components depending on the plant or animal from which they are derived. For example, palm oil, soybean oil, tall oil, castor oil, and various other oils can be mentioned, and those modified with an ethyleneoxy group or a propyleneoxy group are also preferably used. From the compatibility with the mixture of the acrylate compound (A), the urethane acrylate compound (B), and the acrylate compound (C), hydrogenated palm oil and hydrogenated castor oil are preferable, and it is more preferable to use them in combination. As the hydrogenated castor oil, an ethylene oxide adduct is preferable.

<Resin fine particles (F)>
The ultraviolet-curable coating composition of the present invention preferably further contains resin fine particles (F) having an average particle size of 1.0 to 10.0 μm. Here, the average particle diameter indicates a value of an integrated value 50% (D50) in a particle size distribution obtained by a laser diffraction / scattering method. The resin fine particles (F) are mainly used for the purpose of imparting slipperiness, and prevent damage on a production line at the time of manufacturing a laminate described later. Further, it has an effect of slightly roughening the surface of the cured film of the ultraviolet-curable coating agent composition to prevent reflection of a fluorescent lamp or the like, and an effect of intentionally giving a glaring feeling to give a design property.

The resin fine particles (F) may be any resin type, for example, polyurethane resin type, polynylon resin type, polyacrylic resin type, polysilicone resin type, polystyrene resin type, melamine resin type, polyurethane acrylic resin type, polyester resin type. And polyethylene resin-based resins. These may be used in combination of two or more. Of these, urethane-based and acrylic-based resin particles are preferable, and acrylic-based resin fine particles are most preferable. The amount of the resin fine particles (F) to be added is preferably 0.05 to 5.0% by weight based on 100% by weight of the ultraviolet-curable coating composition.

(solvent)
Further, the ultraviolet-curable coating composition of the present invention preferably does not use an organic solvent and / or water as a solvent. The solvent referred to here does not correspond to a trace amount of an organic solvent or water derived from the raw material used, but means a solvent intentionally used for the purpose of dilution or lowering the viscosity. By not using an organic solvent, it contributes to environmental conservation by preventing scattering of the organic solvent (low VOC) and power saving by reducing the drying process.

In the case of using an organic solvent in the ultraviolet-curable coating agent composition of the present invention, it is preferable to use the organic solvent to a minimum extent without impairing the film performance and printing / coating performance. As the organic solvent that can be used, known organic solvents can be used, for example, alcohol solvents such as methanol, ethanol and isopropanol, ester solvents such as ethyl acetate and propyl acetate, glycol ether solvents such as propylene glycol monomethyl ether, and acetone. And ketone solvents such as methyl ethyl ketone, aromatic solvents such as toluene and xylene, and mixtures thereof.

The preferred viscosity of the ultraviolet-curable coating agent composition of the present invention is 50 to 3000 mPa · s / 25 ° C., more preferably 100 to 2000 mPa · s / 25 ° C. using a B-type viscometer. Viscosity suitable for coating with.

(Other acrylic monomers)
The ultraviolet-curable coating composition of the present invention may contain other acrylate compounds as long as the effect is not impaired.

Other acrylate compounds include acrylic monomers, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate Hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylic acid Examples include tetradecyl, hexadecyl (meth) acrylate, and octadecyl (meth) acrylate.

The acrylic monomer may have a hydroxyl group, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylate. (Meta) such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl (meth) acrylate ) Hydroxyalkyl acrylates, glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, and caprolactone-modified (meth) Acrylate and hydroxyethyl acrylamide.

Other acrylic monomers containing an amino group include, for example, (meth) acryloylmorpholine, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, ( And monoalkylamino (meth) acrylates such as monoethylaminopropyl (meth) acrylate.

Further, other acrylic monomers may have a polyether structure. For example, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, methoxypolypropylene Glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, phenoxy polypropylene glycol (meth) acrylate, and the like.

Further, the other acrylic monomer may contain two acryloyl groups. For example, ethylene glycol di (meth) acrylate, hexamethylene glycol di (meth) acrylate, nonanediol di (meth) acrylate, decanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) Acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide-modified bisphenol A-type di (meth) acrylate, propylene oxide-modified bisphenol A-type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,6-hexanediol ethylene oxide-modified di (meth) acrylate, glycerin di ( (Meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, phthalic acid diglycidyl ester di (meth) acrylate, hydroxypivalic acid-modified neopentyl Glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, 2- (meth) acryloyloxyethyl acid phosphate diester, and the like. It is.

The ultraviolet-curable coating agent composition of the present invention can appropriately contain known additives as additives, for example, a leveling agent, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, other than an amine-based photosensitizer. Sensitizers, curing agents, plasticizers, wetting agents, adhesion aids, antifoaming agents, antistatic agents, trapping agents, antiblocking agents, wax components, silica particles, resin particles, preservatives, etc. can be used. . Furthermore, oils, flame retardants, fillers, stabilizers, reinforcing agents, matting agents, grinding agents, organic fine particles, inorganic fine particles, polymer compounds (acrylic resin, polyester resin, polyurethane (urea) resin, vinyl chloride-acetic acid) Vinyl copolymer resin).

As the leveling agent, a known general leveling agent can be used as long as it has a function of imparting wettability to the substrate of the coating liquid and a function of lowering the surface tension.For example, a silicone-modified resin, a fluorine-modified resin, An alkyl-modified resin or the like can be used.

Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, hydroquinone monomethyl ether, and mono-t-. Butyl hydroquinone, pt-butylcatechol, p-methoxyphenol and the like can be mentioned.

As the ultraviolet absorber, for example, metal oxide fine particles such as titanium dioxide, zinc oxide, iron oxide, cerium oxide, thallium oxide, lead oxide, and zirconium oxide can be used as the inorganic ultraviolet absorber. Examples of organic UV absorbers include benzotriazole UV absorbers, triazine UV absorbers, benzoxazine UV absorbers, salicylate UV absorbers, diphenylmethanone UV absorbers, and 2-cyanopropenoic acid. Ester UV absorbers, anthranilate UV absorbers, cinnamic acid derivative UV absorbers, camphor derivative UV absorbers, benzalmalonate derivative UV absorbers, resorcinol UV absorbers, oxalinide UV absorbers And a coumarin derivative-based ultraviolet absorber. Above all, a benzotriazole-based ultraviolet absorber is preferable.

Examples of the benzotriazole-based ultraviolet absorber include 2- (2′-hydroxy-5′-t-octylphenyl) -benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) -benzotriazole, 2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6 [(2H-benzotriazol-2-yl) phenol]], 2- (2H-benzotriazol-2-yl) -4 -(1,1,3,3-tetramethylbutyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol and the like. Can be. Among them, 2- (2'-hydroxy-5'-t-octylphenyl) -benzotriazole and 2- (2'-hydroxy-5'-methylphenyl) -benzotriazole are particularly preferred.

Examples of the triazine-based ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol and 2,4,6-tris- (Diisobutyl-4′-amino-benzalmalonate) -s-triazine, 4,6-tris (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2- (2-hydroxy- 4-octyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxyphenyl) -4,6-bis (2,4- Dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-propyloxyphenyl) -6- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-H Proxy-4-dodecyloxy-phenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine and the like.

Examples of diphenylmethanone-based ultraviolet absorbers include diphenylmethanone, methyldiphenylmethanone, 4-hydroxydiphenylmethanone, 4-methoxydiphenylmethanone, 4-octoxydiphenylmethanone, and 4-decyloxydiphenylmethanone. , 4-dodecyloxydiphenylmethanone, 4-benzyloxydiphenylmethanone, 4,2 ', 4'-trihydroxydiphenylmethanone, 2'-hydroxy-4,4'-dimethoxydiphenylmethanone, 4- (2 -Ethylhexyloxy) -2-hydroxy-diphenylmethanone, methyl o-benzoylbenzoate, benzoin ethyl ether and the like.

Examples of the 2-cyanopropenoic acid ester ultraviolet absorber include ethyl α-cyano-β, β-diphenylpropenoic acid ester, isooctyl α-cyano-β, β-diphenylpropenoic acid ester, and the like.

Examples of the salicylate-based ultraviolet absorber include isocetyl salicylate, octyl salicylate, glycol salicylate, and phenyl salicylate.

Examples of the anthranilate UV absorber include menthyl anthranilate and the like.

Examples of the cinnamic acid derivative-based ultraviolet absorber include, for example, ethylhexyl methoxycinnamate, isopropyl methoxycinnamate, isoamyl methoxycinnamate, diisopropylmethyl cinnamate, glyceryl-ethylhexanoate dimethoxy cinnamate, methyl-α-carbomethoxy cinnamate And methyl-α-cyano-β-methyl-p-methoxycinnamate.

Examples of the camphor derivative ultraviolet absorber include benzylidene camphor, benzylidene camphor sulfonic acid, camphor benzalkonium methosulfate, terephthalidene dicamphor sulfonic acid, and polyacrylamidomethylbenzylidene camphor.

Examples of the resorcinol-based ultraviolet absorber include dibenzoyl resorcinol and bis (4-tert-butylbenzoyl resorcinol).

Examples of oxalinide-based ultraviolet absorbers include 4,4'-di-octyloxyoxanilide, 2,2'-diethoxyoxyoxanilide, and 2,2'-di-octyloxy-5,5'-. Di-tert-butyl oxanilide, 2,2'-di-dodecyloxy-5,5'-di-tert-butyl oxanilide, 2-ethoxy-2'-ethyl oxanilide, N, N'- Bis (3-dimethylaminopropyl) oxanilide, 2-ethoxy-5-tert-butyl-2'-ethoxyoxanilide and the like can be mentioned.

Examples of the coumarin derivative-based ultraviolet absorber include 7-hydroxycoumarin and the like.

The light stabilizer is one that captures radicals generated by photodegradation, for example, thiol-based, thioether-based, hindered amine-based compounds and other radical scavengers, and benzophenone-based and benzoate-based compounds such as ultraviolet absorbers And these may be used alone or in combination of two or more. Above all, it is preferable to use a hindered amine compound from the viewpoint of further improving compatibility and light stability.

Examples of the hindered amine compound include cyclohexane and N-butyl-2,2,6,6-tetramethyl-4-piperidineamine-2,4,6-trichloro-1,3,5-triazine. Reaction product of reaction product and 2-aminoethanol (trade name: Tinuvin 152 (manufactured by BASF)), bis (2,2,6,6-tetramethyl-1- (octyloxy) decandioate) A hindered amine compound having an aminoether group, such as -4-piperidinyl) ester (trade name: Tinuvin 123 (manufactured by BASF)), a reaction product of 1,1-dimethylethyl hydroperoxide and octane, N-acetyl- 3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione (trade name: Hostav) N3058 (manufactured by Clariant Japan KK)) and other N-acetyl hindered amine compounds, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (trade name: SANOL LS765 (BASF Japan KK) )), Bis (1,2,2,6,6-pentamethyl-4-piperidyl) {[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl} butylmalonate Name: Tinuvin (registered trademark) 144 (manufactured by BASF Japan Ltd.)), a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (trade name: Tinuvin ( (Registered trademark) 622LD (manufactured by BASF Japan Ltd.)), Provandioic Acid [{4-methoxyphenyl} N-alkyl hindered amine compound of [Tylene] -bis (1,2,2,6,6-pentamethyl-4-piperidyl) ester (trade name: Hostavin (registered trademark) PR-31 (manufactured by Clariant Japan KK)) Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, poly [{6- (1,1,3, 3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene} (2,2,6 , 6-Tetramethyl-4-piperidyl) imino}], 2,2'-thiobis (4-t-octylphenolate) alkylamine nickel, dibutylamine / 1,3,5-triazi N, N-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine And the like. Among them, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate are preferred.

As the curing agent, tolylene diisocyanate, an adduct derived from hexamethylene diisocyanate, and the like, a polyisocyanate compound represented by a nullate, and the like, a polyfunctional epoxy compound, a melamine compound, a metal chelate, and the like are used. Can be.

Further, the ultraviolet curable coating composition of the present invention may contain other additives in addition to the above-mentioned ones. Other additives include, for example, a thixotroping agent, a curing accelerator, a tackifier, a heat stabilizer, a fluorescent brightener, a foaming agent, a thermoplastic resin, a thermosetting resin, a conductivity imparting agent, and an improvement in moisture permeability. Agents, water repellents, hollow foams, crystallization water-containing compounds, water absorbents, hygroscopic agents, deodorants, foam stabilizers, fungicides, algal inhibitors, hydrolysis inhibitors, organic and inorganic water-soluble compounds, etc. Can be used.

As a method for producing the ultraviolet-curable coating composition of the present invention, an acrylate compound (A), a urethane acrylate compound (B), an acrylate compound (C) and a benzophenone-based photopolymerization initiator (D) are stirred with a disper or the like. It can be manufactured by stirring for about 30 minutes to 3 hours. In addition, when mixing is difficult and viscosity and the like are likely to be non-uniform, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill, or the like may be used.

When the ultraviolet-curable coating composition of the present invention contains bubbles or unexpectedly large particles, it is preferable to remove the particles by filtration or the like in order to reduce the quality of printed matter. A conventionally known filter can be used.

<Laminate>
The ultraviolet-curable coating agent composition of the present invention is effectively used as a curable composition for forming a coating film which is a coat layer (top coat layer) on various substrates having a print layer. Alternatively, it is possible to obtain a laminate having excellent adhesion to the print layer, abrasion resistance, and excellent curability with little cracking or peeling of the coat layer even when the substrate is bent.

The method for producing the laminate of the present invention is not particularly limited, but preferably, the printing ink composition is printed and dried or ultraviolet-cured on a substrate to form a printing layer, and the ultraviolet-curable type of the present invention is further formed thereon. It can be produced by printing and ultraviolet curing the coating composition.

<Paper substrate>
The substrate is preferably paper, such as ordinary paper or corrugated cardboard, and the film thickness is not particularly specified, but those having a thickness of 0.2 mm to 1.0 mm can be used, and the printed surface may be corona-treated. The surface of the paper substrate may be vapor-deposited with a metal such as aluminum for the purpose of imparting a design property, and further subjected to a surface coating treatment with an acrylic resin, a urethane resin, a polyester resin, a polyolefin resin, or another resin. Surface treatment such as corona treatment. For example, coated cardboard and mari-coated paper may be mentioned, and the UV-curable coating agent composition of the present invention is more suitable to use a paper substrate for improving physical properties such as bending resistance.

<Transparent plastic substrate>
The ultraviolet-curable coating composition of the present invention may be used for a transparent plastic substrate. Examples of such a transparent plastic substrate include a primer-coated polypropylene and a polyethylene terephthalate substrate, which can be used in the same manner as the above-mentioned paper substrate.

<Printing ink composition>
The printing ink composition includes, for example, a gravure ink composition, a flexographic ink composition, an ultraviolet curable flexographic ink composition, an offset ink composition, an ultraviolet curable offset ink composition, and other ink compositions. A printing ink composition may be used. Above all, when the ultraviolet-curable offset ink composition and the ultraviolet-curable flexographic ink composition are laminated with the ultraviolet-curable coating agent composition of the present invention, the ultraviolet-curing reaction occurs between the layers, so that the adhesiveness is improved. Therefore, an ultraviolet curable offset ink composition and an ultraviolet curable flexographic ink composition are more preferable.

The gravure ink composition, the flexographic ink composition or the offset ink composition is composed of a pigment, a binder, an additive, a solvent or water, and the binder is, for example, a nitrocellulose type, a fiber material such as cellulose acetate propionate, Chlorinated polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, acrylic, polyurethane and acrylic urethane, polyamide, polybutyral, cyclized rubber, chlorinated rubber, rosin-modified phenolic resin, alkyd Resin-based resins may be used, and these may be used in combination as appropriate.
The ultraviolet-curable offset ink composition and the ultraviolet-curable flexo ink composition contain a urethane acrylate compound resin, a diallyl phthalate (DAP) resin, an inert resin having no double bond, and the like, and further contain a monomer. Examples of the monomer include a monofunctional (meth) acrylic monomer, a polyfunctional (meth) acrylic monomer, and other monomers, and preferably include a trifunctional or higher functional polyfunctional (meth) acrylic monomer.

There are no particular restrictions on the pigment used in the printing ink composition, and organic and inorganic pigments used in general inks, paints, recording agents, and the like can be used in combination. As organic pigments, azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethineazo, dictopyrrolopyrrole, isoindoline, etc. Pigments. Although not limited to the following examples, for example, carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophtal yellow, chromophtal red, phthalocyanine blue, phthalocyanine green, dioxazine violet Quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigment, etc. No.

Examples of the white inorganic pigment as a pigment in the printing ink composition include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica. It is preferable to use titanium oxide for the pigment of the white ink in terms of coloring power, hiding power, chemical resistance, and weather resistance. From the viewpoint of printing performance, the titanium oxide is treated with silica and / or alumina and / or with polyol. Is preferred.

Examples of the inorganic pigment other than the white pigment include, but are not limited to, carbon black, aluminum powder, mica (mica), bronze powder, chrome vermillion, graphite, cadmium yellow, cadmium red, ultramarine, and navy blue. , Bengara, yellow iron oxide, iron black, titanium oxide, zinc oxide, and the like. Aluminum is in powder or paste form, but is preferably used in paste form in terms of handling and safety, leafing or non-leafing. Whether to use leafing is appropriately selected from the viewpoints of brightness and density.

In the production of the printing ink composition used in the present invention, if necessary, known additives such as a pigment derivative, a pigment dispersant, a wetting agent, an adhesion auxiliary, a leveling agent, a defoaming agent, and an antistatic agent , A trapping agent, an anti-blocking agent, a wax component, silica particles, a polymerization inhibitor, a color separation inhibitor, and the like.

<Lamination method>
As a printing method of the printing ink composition, a known method can be used. For example, a gravure printing method, a flexographic printing method, an offset printing method, a screen printing method and the like can be mentioned. The thickness of the ink layer is preferably from 0.1 μm to 15 μm. When the thickness is less than 0.1 μm, the ink coloring is insufficient, while when it exceeds 15 μm, the ink layer becomes brittle.
The printing ink composition may be any of an oil-based ink composition, a water-based ink composition, and an ultraviolet-curable ink composition, and can be dried or ultraviolet-cured after printing to form a print layer.

The method of applying the ultraviolet-curable coating agent composition is not particularly limited, and includes, for example, spray, shower, dipping, flow coating, gravure printing, flexographic printing, roll, spin, dispenser, inkjet printing, screen printing, and the like. Such as a wet coating method.

Ultraviolet rays for curing the ultraviolet-curable coating agent composition include far ultraviolet rays, ultraviolet rays, and near ultraviolet rays. On the other hand, it is possible to use an electron beam or a proton beam. In this case, curing can be performed without using a photopolymerization initiator. Is preferred.

As a method of curing by ultraviolet irradiation, using a high-pressure mercury lamp, ultra-high-pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, electrodeless discharge lamp, LED, etc. 30~5000mJ / cm ^2, it may be preferably 100~1000mJ / cm ² irradiation. After the ultraviolet irradiation, if necessary, heating can be performed to complete the curing.

The film thickness (film thickness after curing) when applying the ultraviolet curable coating composition is usually preferably 1 to 20 μm, and particularly preferably 2 to 10 μm. Within this range, there is no curing inhibition, the irradiation time of ultraviolet rays can be shortened, and the productivity is good.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the present invention, parts and% mean parts by weight and% by weight, respectively, unless otherwise specified.
For the weight average molecular weight in the examples, GPC (gel permeation chromatography) “Shodex GPC System-21” manufactured by Showa Denko KK was used. GPC is a liquid chromatography in which a substance dissolved in a solvent is separated and quantified by a difference in molecular size. Tetrohydrofuran is used as a solvent, and the weight average molecular weight is determined in terms of polystyrene.

In this specification, the glass transition temperature of the cured film formed by the acrylate compound (A) and the acrylate compound (C) was measured using a differential scanning calorimeter (DSC) on the film after ultraviolet curing. The average particle diameter in the resin fine particles (F) is a particle diameter at an integrated value of 50% (D50) in the particle size distribution obtained by a laser diffraction / scattering method.

<Production of mixture of urethane acrylate compound (B) and acrylate compound (C)>
[Synthesis Example 1]
25.4 parts of hexamethylene diisocyanate (hereinafter, referred to as “HDI”) and about pentaerythritol triacrylate were introduced into a flask equipped with a stirring blade, a thermometer, a reflux condenser, and a gas inlet tube at a temperature of 90 ° C. while blowing air into the flask. 200 parts of a mixture of 45% by weight / about 55% by weight of pentaerythritol tetraacrylate (trade name: "Aronix M303" manufactured by Toagosei Co., Ltd.) was reacted for 6 hours while stirring at 250 rpm. Note that NCO / OH in the mixture was set to 1/1. After confirming disappearance of the isocyanate group by an IR spectrum, the mixture was cooled to room temperature to obtain a mixture of UA1 and pentaerythritol tetraacrylate. The urethane acrylate compound (B) was compound UA1: the acrylate compound (C) was pentaerythritol tetraacrylate = 50: 50 (weight ratio), and the weight average molecular weight of UA1 was 800.

[Synthesis Examples 2 to 5]
With the raw materials and the mixing ratio (molar ratio) described in Table 1, a mixture of UA2 to UA5 and the acrylate compound (C) was obtained in the same manner as in Synthesis Example 1.
In addition, in Table 1,
"IPDI" represents isophorone diisocyanate,
"Isocyanurate-modified HDI" represents a compound in which hexamethylene diisocyanate is trimerized to form an isocyanurate ring,
"PET3A" represents pentaerythritol triacrylate, "PET4A" represents pentaerythritol tetraacrylate,
"DPPA" represents dipentaerythritol pentaacrylate, and "DPHA" represents dipentaerythritol hexaacrylate.
In Synthesis Examples 3 and 4, as in Synthesis Example 1, a mixture of about 45% by weight of pentaerythritol triacrylate / about 55% by weight of pentaerythritol tetraacrylate (trade name: "Aronix M303" manufactured by Toagosei Co., Ltd.) was reacted. In Synthesis Example 2, a mixture of about 45% by weight of dipentaerythritol pentaacrylate / about 55% by weight of dipentaerythritol hexaacrylate (trade name: "Aronix M400" manufactured by Toagosei Co., Ltd.) was used for the reaction. A mixture of about 25% by weight of pentaerythritol triacrylate / about 75% by weight of pentaerythritol tetraacrylate (trade name: "Aronix M452" manufactured by Toagosei Co., Ltd.) was used for the reaction.

(Example 1: Preparation of ultraviolet curable coating agent composition S1)
47 parts of an oligomer of ethylene oxide-added trimethylolpropane triacrylate (hereinafter referred to as “TMP-EO-TA”) (product name: SR499, manufactured by Sartomer Co., Tg-8 ° C.) having an addition mole number of 6, and urethane acrylate UA1: PET4A = 1: 1 mixture of 40 parts, p-methylbenzophenone 10 parts and N-methyldiethanolamine 3 parts were mixed and stirred with a disper for 40 minutes to obtain an ultraviolet curable coating composition S1.

(Examples 2 to 19: Preparation of UV curable coating agent compositions S2 to S19)
UV curable coating compositions S2 to S19 were obtained from the raw materials shown in Table 2-1 at the blending ratios described in the same manner as in Example 1.

(Comparative Examples 1 to 11: Preparation of UV curable coating agent compositions T1 to T11)
UV curable coating agent compositions T1 to T11 were obtained from the raw materials shown in Table 2-2 at the blending ratios described in the same manner as in Example 1.

The compounds described in Table 2-1 and Table 2-2 are as follows.
-TMP-EO-TA (3 mol): 3 mol of ethylene oxide-added tolmethylolpropane triacrylate, product name Miramer M3130, manufactured by MIWON, Tg 40 ° C
-TMP-EO-TA (9 mol): 9 mol of ethylene oxide-added tolmethylolpropane triacrylate, product name SR499, manufactured by Sartomer, Tg-19 ° C
-TMP-EO-TA (15 mol): 15 mol of ethylene oxide-added tolmethylolpropane triacrylate, product name SR502, manufactured by Sartomer, Tg-32 ° C
-TMP-PO-TA (6 mol): 6 mol of propylene oxide-added tolmethylolpropane triacrylate, product name SR499, manufactured by Sartomer, Tg-2 ° C
Glycerin-PO-TA (5.5 mol): 5.5 mol of propylene oxide added glycerin triacrylate, product name CD9021, manufactured by Sartomer, Tg-11 ° C
Here, Tg represents a catalog value.
Further, as acrylic fine particles having an average particle diameter of 3 μm and 6 μm, J-5P and J-7P manufactured by Negami Kogyo Co., Ltd. were used. In addition, MM-120T manufactured by Negami Kogyo Co., Ltd. was used as urethane fine particles having an average particle diameter of 3 μm.
In addition, the hydrogenated castor oil EO modified product is a hydrogenated castor oil to which ethylene oxide has been added, and EMALEX HC-30 manufactured by Nippon Emulsion Co., Ltd. was used.
As photopolymerization initiators other than the benzophenone-based photopolymerization initiator (D), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173 manufactured by Ciba Japan), 1-hydroxy-cyclohexyl-phenyl -Ketone (Irgacure 184 manufactured by Ciba Japan) and 2,2-dimethoxy-1,2-diphenylethan-1-one (Irgacure 651 manufactured by Ciba Japan) were used.

(Example 20)
<Preparation of laminate>
In Example 1, UV offset ink (FD Carton X Ink M: manufactured by Toyo Ink Co., Ltd., including trifunctional or higher functional (meth) acrylic monomer) was previously printed on coated cardboard. The obtained S1 was applied to a film thickness of 5.0 μm by dry coating with a bar coater # 3, and cured under the conditions of one high-pressure mercury lamp of 160 W / cm, irradiation distance of 10 cm and integrated light quantity of 300 mj / cm ² . Thus, a laminate SS1 was obtained. In addition, the printing conditions of the UV offset ink were such that printing was performed so that the film thickness of FD Carton X Black M was 1.0 μm using a simple color developing machine RI tester, one high-pressure mercury lamp, and an integrated light amount of 100 mj / cm ^2. And cured.

(Examples 21 to 38)
In the same manner as in Example 21, laminates SS2 to SS19 were obtained using the ultraviolet-curable coating agent compositions S2 to S19 described in Table 2-1.

(Comparative Examples 12 to 22)
In the same manner as in Example 21, laminates TT1 to TT11 were obtained using the UV-curable coating agent compositions T1 to T11 described in Table 2-2.

<Examples 21 to 38 and Comparative Examples 12 to 22>
Viscosity at 25 ° C. (using a B-type viscometer) for UV-curable coating agent compositions S1 to S19 and T1 to T11, bending resistance for laminates SS1 to SS19 (Example) and laminates TT1 to TT11 (Comparative Example) , A curing speed (integrated light amount), a friction resistance test, a slip resistance test, a bending resistance test, and the like, and the results are shown in Tables 3-1 and 3-2.

<Viscosity at 25 ° C.>
The viscosities at 25 ° C. of the ultraviolet curable coating agent compositions S1 to S19 and T1 to T11 were measured with a B-type viscometer. The criteria are as follows.
When the numerical value is 100 to 1500 mPa · s, there is no practical problem, and when the numerical value is 200 to 700 mPa · s, the viscosity is low, which is preferable.
If the viscosity is less than 100 mPa · s, bleeding into the paper substrate may occur, which is not preferable.
-If the viscosity exceeds 1500 mPa · s, the coating is difficult because the viscosity is too high.

<Curability>
The UV curable coating agent compositions S1 to S19 and T1 to T11 were applied on a glass plate with an applicator to a thickness of 250 μm, and only the integrated light amount (mj / cm ² ) was changed under the same conditions as in Example 21. After curing, the film surface was strongly pressed with a nail, and the integrated light amount when no trace was left was determined. In the practical range, the integrated light amount is 200 mj / cm ² or less.

<Friction resistance test>
The laminates SS1 to SS19 (Example) and the laminates TT1 to TT11 (Comparative Example) were set on a Gakushin testing machine, and a load of 800 g was applied between coated surfaces (face-to-face coating) or using steel wool No. 0000. Was made to learn 10 times. With respect to the coated product taken out, the degree of scratching was visually evaluated in the following five stages.
○ ・ ・ ・ ・ ・ ・ No scratches.
○ △ ・ ・ ・ ・ ・ ・ Slightly scratched.
Δ ············ Although scratches are present, the substrate is not visible.
△ × ・ ・ ・ ・ ・ ・ Scratched, part of the coated product peeled off.
×: The coated material was peeled off, and the substrate was exposed.
、, △ are in the range where there is no practical problem.

<Slipperiness>
A test was performed on the laminates SS1 to SS19 (Example) and the laminates TT1 to TT11 (Comparative Example) with a slip angle measuring device.
・: The slip angle is 20 ° or less.
○ △: The slip angle is 20 to 25 °.
Δ: The slip angle is 25 to 30 °.
Δ × ··· Slip angle is 30 to 35 °.
×: The slip angle is 35 ° or more.
、, △ are in the range where there is no practical problem.

<Fingerprint resistance test>
Fingerprint resistance tests were performed on the laminates SS1 to SS19 (Example) and the laminates TT1 to TT11 (Comparative Example). The evaluation was performed with a contact area between the finger and the sample: 1 to ² cm ² and a force for pressing the sample with the finger: about 3.0 × 10 ³ Pa, and the fingerprint resistance was evaluated.
○ ・ ・ ・ ・ ・ ・ ・ Fingerprints do not appear at all.
○ △: 5% or less of fingerprints remain.
Δ: 5 to 30% of the fingerprint remains.
Δ ×: 30 to 60% of fingerprints remain.
×: Fingerprint remains 60% or more.
、, △ are in the range where there is no practical problem.

<Bending resistance>
Regarding the laminates SS1 to SS19 (Example) and the laminates TT1 to TT11 (Comparative Example) (integrated light amount 300 mj / cm ² ), they are folded back 180 ° in the direction of the non-coating surface, and further bent 180 ° in the same part in the direction of the coating surface. Was performed, and the bending line portion was visually evaluated.
○ ・ ・ ・ ・ ・ ・ ・ Break at the bending line and no whitening.
○ △: Cracks at the bent line portion were less than 20%, slightly whitened.
・: Cracks at the bending line portion are 20 to 60%, all whitened.
△ × ・ ・ ・ ・ 60-80% of cracks in the bending line portion, all whitened.
×: The bending line portion is 100% cracked, and fragments fall off.

From the evaluation results, an ultraviolet-curable coating agent composition for forming a coat layer for protecting a substrate having a print layer on at least a part of the surface, wherein the added mole number of the alkylene oxide is 4 to 20. 20 to 70% by weight of an acrylate compound (A) having three or more functions, an aliphatic and / or alicyclic diisocyanate compound (b1), and a compound having one hydroxyl group and two or more (meth) acrylate groups (b2 ), A urethane acrylate compound (B), which is a reaction product with (B), containing 0 to 45% by weight, and an alkyleneoxy group-free trifunctional or higher acrylate compound (C) of 10 to 50% by weight, and benzophenone-based photopolymerization is started. The ultraviolet curable coating agent composition containing the agent (D) has an appropriate viscosity, and the cured film has bending resistance, rub resistance, fingerprint resistance, and glossiness. It has been found that is.

Claims (8)

An ultraviolet-curable coating agent composition that does not use a solvent and is used for a substrate having a printing ink layer on at least a part thereof, and is characterized by the following (1) and (2).
(1) In the total amount of 100% by weight of the ultraviolet curable compound in the coating agent composition,
20 to 70% by weight of a trifunctional or higher acrylate compound (A) having an addition alkylene oxide mole number of 4 to 20;
The urethane acrylate compound (B) which is a reaction product of the aliphatic and / or alicyclic diisocyanate compound (b1) and the compound (b2) having one hydroxyl group and two or more (meth) acrylate groups is 0 to 45 weight%,
It contains 10 to 50% by weight of a trifunctional or higher acrylate compound (C) having no alkyleneoxy group.
(However, (A) and (C) exclude the case of (B).)
(2) It contains a benzophenone-based photopolymerization initiator (D). The ultraviolet curing type according to claim 1, wherein the glass transition temperature of the acrylate compound (A) after curing is -40 to 10C, and the glass transition temperature of the acrylate compound (C) after curing is 100C or more. Coating composition. The acrylate compound (A) is an ethylene oxide and / or propylene oxide addition acrylate of at least one compound selected from the group consisting of pentaerythritol, dipentaerythritol, trimethylolpropane, and glycerin. 3. The ultraviolet-curable coating composition according to 1 or 2. The UV-curable coating composition according to any one of claims 1 to 3, wherein the acrylate compound (A) is an acrylate added with ethylene oxide and / or propylene oxide of trimethylolpropane. The compound (b2) is at least one selected from the group consisting of pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane di (meth) acrylate, and glyceryl di (meth) acrylate. The ultraviolet-curable coating composition according to any one of claims 1 to 4, wherein The ultraviolet-curable coating composition according to any one of claims 1 to 5, further comprising a hydrogenated fat (E). The ultraviolet curable coating composition according to any one of claims 1 to 6, further comprising resin fine particles (F) having an average particle size of 1.0 to 10.0 µm. A laminate having a coating layer formed from the ultraviolet-curable coating composition according to any one of claims 1 to 7 on a substrate having a printing ink layer at least in part.