阅读说明：本技术 紫外线固化型氨基甲酸酯丙烯酸酯树脂、及含有其的紫外线固化型树脂组合物 (Ultraviolet-curable urethane acrylate resin and ultraviolet-curable resin composition containing same ) 是由 流尾知充 中谷圭佑 于 2020-05-26 设计创作，主要内容包括：本发明提供可形成透明性、拉伸性、防水性、及耐化学品性优异的固化涂膜的紫外线固化型氨基甲酸酯(甲基)丙烯酸酯树脂。根据本发明的紫外线固化型氨基甲酸酯(甲基)丙烯酸酯树脂是使(A)多异氰酸酯化合物、(B)二醇化合物、(C)(甲基)丙烯酸酯化合物、及(D)含羟基的氟化合物反应而得到的。(The invention provides an ultraviolet-curable urethane (meth) acrylate resin which can form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance. The ultraviolet-curable urethane (meth) acrylate resin according to the present invention is obtained by reacting (a) a polyisocyanate compound, (B) a diol compound, (C) a (meth) acrylate compound, and (D) a hydroxyl group-containing fluorine compound.)

1. An ultraviolet-curable urethane (meth) acrylate resin obtained by reacting:

(A) a polyisocyanate compound which is capable of reacting with a polyisocyanate compound,

(B) a diol compound which is a mixture of a diol compound,

(C) (meth) acrylate compound, and

(D) a fluorine compound containing a hydroxyl group.

2. The ultraviolet-curable urethane (meth) acrylate resin according to claim 1, which contains an alicyclic polyisocyanate as the component (A).

3. The ultraviolet-curable urethane (meth) acrylate resin according to claim 1 or 2, which contains a chain aliphatic diol having 2 to 6 carbon atoms as the component (B).

4. The ultraviolet-curable urethane (meth) acrylate resin according to any one of claims 1 to 3, which contains pentaerythritol triacrylate as the component (C).

5. The ultraviolet-curable urethane (meth) acrylate resin according to any one of claims 1 to 4, wherein the equivalent ratio of the component (B) to the component (A) is 0.50 to 0.80.

6. The ultraviolet-curable urethane (meth) acrylate resin according to any one of claims 1 to 5, wherein the equivalent ratio of the component (C) to the component (A) is 0.20 to 0.50.

7. The ultraviolet-curable urethane (meth) acrylate resin according to any one of claims 1 to 5, wherein the amount of the component (D) is 0.01 to 10.0% by mass based on the total amount of the components (A), (B) and (C).

8. An ultraviolet-curable resin composition comprising a photopolymerization initiator and the ultraviolet-curable urethane (meth) acrylate resin according to any one of claims 1 to 7.

9. The ultraviolet-curable resin composition according to claim 8, which is used as a coating material.

10. The ultraviolet-curable resin composition according to claim 9, wherein the coating material is used for a decorative film for in-mold molding.

11. A cured coating film comprising the ultraviolet-curable resin composition according to any one of claims 8 to 10.

12. A substrate with a coating film, comprising the cured coating film according to claim 11 on a substrate.

13. A method for producing a substrate with a coating film, comprising the steps of:

a coating step of coating the ultraviolet curable resin composition according to any one of claims 8 to 10 on at least one surface of a substrate; and

and a curing step of curing the ultraviolet-curable resin composition by ultraviolet irradiation to form a cured coating film after the coating step.

Technical Field

The present invention relates to an ultraviolet-curable urethane acrylate resin. The present invention also relates to an ultraviolet-curable resin composition containing the ultraviolet-curable urethane acrylate resin. The present invention also relates to a cured coating film formed from the ultraviolet curable resin composition, a coated substrate provided with the cured coating film, and a method for producing the coated substrate.

Background

In the field of plastic decoration for use in automobile interior and exterior parts, home appliance housings, and the like, a thermoforming method such as in-mold molding in which a functional decorative film is laminated together is widely used when plastic resin is molded in a mold frame (mold).

The decorative film used in the thermoforming is required to have stretchability for following the three-dimensional shape of the plastic as an adherend, and therefore, the resin composition applied to the film surface for imparting functionality is also required to have stretchability. As the resin composition having stretchability, a thermosetting resin composition may be used, but from the viewpoint of productivity, blocking property when the film is wound, and the like, an ultraviolet-curable resin composition is preferably used. For example, as an ultraviolet curable resin composition having a high elongation at break and excellent moldability, there has been proposed a use of a urethane acrylate oligomer obtained by reacting a polyfunctional acrylate monomer, a polyol, an isocyanate monomer or an organic polyisocyanate (see patent document 1).

In addition, from the viewpoint of chemical resistance and stain resistance, the decorative film is also required to have properties such as stain resistance (water resistance).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-111793

Disclosure of Invention

Problems to be solved by the invention

The inventors of the present application tried to add an additive (stain-proofing agent) such as a fluorine compound to a coating material (resin composition) of a decorative film in addition to a urethane acrylate resin in order to impart chemical resistance and water repellency (stain-proofing property) to a resin molded product. However, it has been found that since a resin such as a urethane acrylate oligomer described in patent document 1 has a strong cohesive force, when an additive such as a fluorine compound is added later, the resin is retained in a cured coating film and is difficult to orient on the surface of the coating film, and water repellency (stain resistance) is difficult to develop. Therefore, it is desired that the urethane acrylate resin itself exhibits water repellency (stain resistance) without adding an additive such as a fluorine compound (stain resistance agent) to the resin composition. Further, in decorating a resin molded product, since the urethane acrylate resin is located at the outermost surface, it is also desirable that the transparency is high so as not to interfere with the design of a printing layer, a pattern layer, and the like located therebelow.

The present invention has been made in view of the above-mentioned background art and the new technical problem, and an object thereof is to provide an ultraviolet-curable urethane (meth) acrylate resin capable of forming a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance.

Means for solving the problems

The present inventors have intensively studied to solve the above problems, and as a result, they have found that the above problems can be solved by using an ultraviolet-curable urethane (meth) acrylate resin obtained by reacting (a) a polyisocyanate compound, (B) a diol compound, (C) a (meth) acrylate compound, and (D) a hydroxyl group-containing fluorine compound. The present invention has been completed based on the above findings.

That is, the present invention provides the following inventions.

[1] An ultraviolet-curable urethane (meth) acrylate resin obtained by reacting:

(A) a polyisocyanate compound which is capable of reacting with a polyisocyanate compound,

(B) a diol compound which is a mixture of a diol compound,

(C) (meth) acrylate compound, and

(D) a fluorine compound containing a hydroxyl group.

[2] The ultraviolet-curable urethane (meth) acrylate resin according to [1], which contains an alicyclic polyisocyanate as the component (A).

[3] The ultraviolet-curable urethane (meth) acrylate resin according to [1] or [2], which contains a chain aliphatic diol having 2 to 6 carbon atoms as the component (B).

[4] The ultraviolet-curable urethane (meth) acrylate resin according to any one of [1] to [3], which contains pentaerythritol triacrylate as the component (C).

[5] The ultraviolet-curable urethane (meth) acrylate resin according to any one of [1] to [4], wherein the equivalent ratio of the component (B) to the component (A) is 0.50 to 0.80.

[6] The ultraviolet-curable urethane (meth) acrylate resin according to any one of [1] to [5], wherein the equivalent ratio of the component (C) to the component (A) is 0.20 to 0.50.

[7] The ultraviolet-curable urethane (meth) acrylate resin according to any one of [1] to [6], wherein the amount of the component (D) is 0.01 to 10.0% by mass based on the total amount of the components (A), (B) and (C).

[8] An ultraviolet-curable resin composition comprising a photopolymerization initiator and the ultraviolet-curable urethane (meth) acrylate resin according to any one of [1] to [7 ].

[9] The ultraviolet-curable resin composition according to [8], which is used as a coating material.

[10] The ultraviolet-curable resin composition according to [9], wherein the coating material is used for a decorative film for in-mold molding.

[11] A cured coating film comprising the ultraviolet-curable resin composition according to any one of [8] to [10 ].

[12] A substrate with a coating film, comprising the cured coating film according to [11] on a substrate.

[13] A method for producing a substrate with a coating film, comprising the steps of:

a coating step of coating the ultraviolet-curable resin composition described in any one of [8] to [10] on at least one surface of a substrate; and

and a curing step of curing the ultraviolet-curable resin composition by ultraviolet irradiation after the coating step to form a cured coating film.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide an ultraviolet-curable urethane (meth) acrylate resin that can form a cured coating film having excellent transparency, stretchability, water resistance, and chemical resistance. The present invention also provides a resin composition containing such an ultraviolet-curable urethane (meth) acrylate resin. Further, a cured coating film formed from such an ultraviolet-curable resin composition, a coated substrate provided with the cured coating film, and a method for producing a coated substrate can be provided.

Drawings

Fig. 1 is a schematic sectional view showing a substrate with a coating film according to the present invention.

Detailed Description

< UV-curable urethane (meth) acrylate resin >

The ultraviolet-curable urethane (meth) acrylate resin according to the present invention is obtained by reacting (a) a polyisocyanate compound, (B) a diol compound, (C) a (meth) acrylate compound, and (D) a hydroxyl group-containing fluorine compound. Such an ultraviolet-curable urethane (meth) acrylate resin can form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance. Therefore, the ultraviolet-curable resin composition containing an ultraviolet-curable urethane (meth) acrylate resin according to the present invention can be suitably used as a coating material, particularly as a coating material for a decorative film for in-mold molding.

In the present specification, "(meth) acrylate" represents acrylate and methacrylate, "(meth) acrylic acid" represents acrylic acid and methacrylic acid, and "(meth) acryloyl group" represents acryloyl group and methacryloyl group.

The weight average molecular weight (Mw) of the ultraviolet-curable urethane (meth) acrylate resin according to the present invention is preferably 2,000 to 30,000, more preferably 5,000 to 25,000, still more preferably 7,000 to 20,000, and particularly preferably 9,000 to 15,000. The weight average molecular weight (Mw) can be determined using Gel Permeation Chromatography (GPC). When the weight average molecular weight (Mw) is within the above numerical range, the coating composition is excellent in stretchability and therefore can be suitably used as a coating material for an in-mold decorative film.

The viscosity of the ultraviolet-curable urethane (meth) acrylate resin at 25 ℃ is preferably 100 to 3,000mPa.s, more preferably 500 to 2,000mPa.s, and still more preferably 700 to 1,500 mPa.s. When the viscosity is within the above numerical range, the processability is excellent.

((A) polyisocyanate Compound)

(A) The polyisocyanate compound of component (a) is a compound having a total of 2 or more isocyanate groups and/or substituents containing isocyanate groups in 1 molecule. The polyisocyanate compound may be used in 1 kind, or 2 or more kinds. In the present invention, the isocyanate group and the substituent containing the isocyanate group may be generically referred to as an "isocyanate group". In the polyisocyanate compound, the isocyanate groups may be the same or different.

Examples of the substituent containing an isocyanate group include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, each of which contains 1 or more isocyanate groups. Among them, an alkyl group having 1 to 5 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is particularly preferable.

The polyisocyanate is not particularly limited in kind, and examples thereof include a chain aliphatic polyisocyanate, an aromatic polyisocyanate, and an alicyclic polyisocyanate, and 1 kind of them may be used, or 2 or more kinds may be used in combination. Among them, alicyclic polyisocyanates are preferably used.

The chain aliphatic polyisocyanate is a compound having a chain aliphatic structure and 2 or more isocyanate groups bonded thereto. The chain aliphatic polyisocyanate is preferable from the viewpoint of improving the stretchability of a cured coating film of the ultraviolet curable resin composition. The structure of the chain aliphatic group in the chain aliphatic polyisocyanate is not particularly limited, and a linear or branched alkylene group having 1 to 6 carbon atoms is preferable. Examples of such a chain aliphatic polyisocyanate include: aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate, and aliphatic polyisocyanates such as tris (isocyanatohexyl) isocyanurate. These may be used alone in 1 kind, or 2 or more kinds may be used in combination.

The aromatic polyisocyanate is a compound having an aromatic structure and 2 or more isocyanate groups bonded thereto. The aromatic structure in the aromatic polyisocyanate is not particularly limited, but an aromatic structure having 6 to 13 carbon atoms is preferred. Examples of the aromatic polyisocyanate include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, and naphthalene diisocyanate. These may be used alone in 1 kind, or 2 or more kinds may be used in combination.

The alicyclic polyisocyanate is a compound having an alicyclic structure and 2 or more isocyanate groups. (A) The alicyclic structure in the component (b) is not particularly limited, but preferably has 5 to 15 carbon atoms, and more preferably has 6 or more carbon atoms. Further, the number of carbon atoms is preferably 14 or less, and particularly preferably 13 or less. In addition, as the alicyclic structure, a cycloalkylene group is preferable. Examples of the polyisocyanate having an alicyclic structure include diisocyanates having an alicyclic structure such as bis (isocyanatomethyl) cyclohexane, cyclohexane diisocyanate, bis (isocyanatocyclohexyl) methane and isophorone diisocyanate, and triisocyanates having an alicyclic structure such as tris (isocyanatoisophorone) isocyanurate. Among them, isophorone diisocyanate is preferably used in order to form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance.

((B) diol Compound)

The diol compound of component (B) is preferably a linear aliphatic diol having 2 to 6 carbon atoms, and specific examples thereof include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 2-methyl-1, 3-propanediol, neopentyl glycol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 2, 3-butanediol, 1, 2-pentanediol, 1, 5-pentanediol, 1, 2-hexanediol, and 1, 6-hexanediol. Among them, ethylene glycol is preferably used in order to form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance.

(B) The equivalent ratio of the component (A) to the component (A) is preferably 0.50 to 0.80, more preferably 0.55 to 0.75, and still more preferably 0.60 to 0.72. When the equivalent ratio of the component (B) to the component (A) is within the above range, the ultraviolet-curable urethane (meth) acrylate resin is likely to form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance.

((C) (meth) acrylate Compound)

The (C) (meth) acrylate compound is a compound having 1 or more hydroxyl groups and 1 or more (meth) acryloyl groups in the molecule. The (meth) acrylate compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the component (C) include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) Acrylate and 2-hydroxypropyl (meth) Acrylate and caprolactone adducts thereof (Placcel FA1, FA2, manufactured by Daiiguo Co., Ltd.), polyalkylene glycol mono (meth) Acrylate, OH-terminated polyalkylene glycol mono (meth) Acrylate such as polypropylene glycol mono (meth) Acrylate, ethylene oxide-modified products thereof (AM-90G, AM-130G, manufactured by Ningkohama chemical Co., Ltd., Light Acrylate EC-A, MTG-A, EHDG-AT, manufactured by Kyowa chemical Co., Ltd.), glycerol mono (meth) Acrylate (BlemGLM, manufactured by Ningkohama chemical Co., Ltd.), glycerol di (meth) Acrylate (Aronix 3560, manufactured by Toyao synthetic Co., Ltd.), isocyanuric acid (EO-modified) diacrylate (Aronix M-313, manufactured by Toyao synthetic Co., Ltd.), Aronix M-313, and the like, 315, etc.), pentaerythritol tri (meth) Acrylate (Viscoat 300, manufactured by Osaka chemical Co., Ltd., Aronix M-305, M-306, MT-3548, manufactured by Kyowa chemical Co., Ltd., Light Acrylate PE-3A, manufactured by Neozhongwa chemical Co., Ltd., NK Ester A-TMM-3L, etc.), dipentaerythritol penta (meth) Acrylate (Light Acrylate DPE-6A, manufactured by Kyowa chemical Co., Ltd., NK Ester A-DPH, etc.).

Among the above (meth) acrylates, pentaerythritol triacrylate is particularly preferably used, and may contain pentaerythritol monoacrylate, pentaerythritol diacrylate and pentaerythritol tetraacrylate. The ultraviolet-curable urethane (meth) acrylate resin using the (meth) acrylate compound is easy to form a cured coating film excellent in transparency, stretchability, water resistance and chemical resistance.

(C) The equivalent ratio of the component (A) to the component (A) is preferably 0.20 to 0.50, more preferably 0.25 to 0.45, and still more preferably 0.30 to 0.40. When the equivalent ratio of the component (C) to the component (a) is within the above range, the ultraviolet-curable urethane (meth) acrylate resin is likely to form a cured coating film excellent in transparency, stretchability, water resistance, and chemical resistance.

(D) fluorine compound containing hydroxyl group)

The fluorine-containing compound having a hydroxyl group is a compound having at least a hydroxyl group and fluorine (fluorine-containing group), and may further have a reactive group. Examples of the reactive group include a (meth) acryloyl group, a vinyl group, an allyl group, and a styryl group.

As the fluorine-containing compound having a hydroxyl group, a fluorine-containing oligomer having a hydroxyl group can be used. The hydroxyl group-containing fluorine-containing oligomer is preferably a hydroxyl group-containing fluorine-containing oligomer having a unit derived from a fluoroolefin, a unit derived from a monomer having a hydroxyl group copolymerizable with the fluoroolefin (hereinafter referred to as "monomer (m 1)"), and, if necessary, a unit derived from a fluoroolefin and a monomer other than the monomer (m1) (hereinafter referred to as "monomer (m 2)").

The fluorine-containing compound having a hydroxyl group may be a fluorine-containing oligomer having a hydroxyl group introduced into the reactive group conversion of the oligomer. As the fluorine-containing oligomer having a hydroxyl group, a fluorine-containing oligomer obtained by: a fluorine-containing oligomer obtained by reacting a fluorine-containing oligomer having a unit derived from a fluoroolefin, a unit derived from a monomer having a reactive group other than a hydroxyl group, and the monomer (m2) as required, with a compound having a reactive group reactive with the reactive group and a hydroxyl group.

The monomer (m1) is a monomer having a hydroxyl group, and may further have a reactive group other than a hydroxyl group. Examples of the monomer having a hydroxyl group include hydroxyalkyl vinyl ethers such as allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and cyclohexanediol monovinyl ether, hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether, hydroxyalkanoate esters such as vinyl hydroxypropionate and hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate. The monomer (m1) may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The monomer (m2) is a monomer having no hydroxyl group and may have a reactive group. Examples of the monomer (m2) include vinyl ether, allyl ether, vinyl formate, allyl formate, and olefin. Examples of the vinyl ether include alkyl vinyl ethers such as nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether and t-butyl vinyl ether, and cycloalkyl vinyl ethers such as cyclohexyl vinyl ether. The monomer (m2) may have the above-mentioned reactive group. The monomer (m2) may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The content of the component (D) in the ultraviolet-curable urethane (meth) acrylate resin is preferably 0.01 to 10.0% by mass, more preferably 0.5 to 5.0% by mass, based on the total amount of the components (a), (B) and (C). When the content of the component (D) is within the above range, a cured coating film excellent in transparency, stretchability, water resistance and chemical resistance can be easily formed from the ultraviolet-curable urethane (meth) acrylate resin.

Specific examples of commercially available component (D) include Ftergent 710FM, Ftergent 601ADH2 (trade name, product name of Neos corporation), Megaface F-558, Megaface F-561, Megaface F-562, Megaface F-563, Megaface F-569, Megaface F-576 (trade name, product name of DIC corporation), Surflon S-647, Surflon S-651, Surflon S-656, and Surflon S-693 (trade name, product name of AGC Seimi Chemical Co., Ltd.).

(reaction)

The ultraviolet-curable urethane (meth) acrylate resin according to the present invention is obtained by reacting the above-mentioned components (a) to (D), and the reaction conditions such as temperature and time can be appropriately set. For example, first, a polymerization inhibitor such as BHT, a tin catalyst such as dibutyltin dilaurate, and the components (A) and (B) are added to a reactor, and the reaction is carried out at 60 to 70 ℃ for 1 to 2 hours, and then the component (D) is added, and the reaction is carried out at 60 to 70 ℃ for 1 to 2 hours. Then, the component (C) is added and the reaction is carried out at 80 to 90 ℃ for 2 to 4 hours to obtain the ultraviolet-curable urethane (meth) acrylate resin according to the present invention. Although the component (D) and the component (C) may be added simultaneously, when the reactivity of the component (C) is high, the unreacted component (D) is less likely to remain when the component (D) is added before the component (C), and thus it is preferable. The end point of the reaction can be confirmed by infrared absorption analysis based on the disappearance of the peak from the isocyanate group.

(ultraviolet ray curable resin composition)

The ultraviolet-curable resin composition according to the present invention (hereinafter, may be simply referred to as "resin composition") contains at least the above-mentioned ultraviolet-curable urethane (meth) acrylate resin and a photopolymerization initiator. The coating film formed by curing the resin composition of the present invention is excellent in transparency, stretchability, water resistance, and chemical resistance. Such a resin composition can be preferably used as a coating material, particularly as a coating material for a decorative film for in-mold molding.

(photopolymerization initiator)

The photopolymerization initiator is not particularly limited, and conventionally known photopolymerization initiators for ultraviolet curing can be used. Examples of the photopolymerization initiator include acetophenone polymerization initiator, phosphine oxide polymerization initiator, benzoyl formate polymerization initiator, thioxanthone polymerization initiator, oxime ester polymerization initiator, hydroxybenzoyl polymerization initiator, benzophenone polymerization initiator, and α -aminoalkylketone polymerization initiator.

Examples of the acetophenone polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl-2-morpholinopropan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

Examples of the phosphine oxide-based polymerization initiator include bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, and the like.

Examples of the benzoylformate polymerization initiator include methylbenzoylformate.

Examples of the thioxanthone-based polymerization initiator include isopropylthioxanthone and the like.

Examples of the oxime ester polymerization initiator include 1- [4- (phenylsulfanyl) -1, 2-octanedione-2- (O-benzoyloxime) ] and 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -ethanone-1- (O-acetyloxime).

Examples of the hydroxybenzoyl-based polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, and the like.

Examples of the benzophenone-based polymerization initiator include benzophenone, 4-chlorobenzophenone, and 4,4' -diaminobenzophenone.

Examples of the α -aminoalkylphenone-based polymerization initiator include 2-methyl-1- (4-methylthiophenyl) -2-morpholino-butanone-1 and 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholine) phenyl ] -1-butanone.

From the viewpoint of curability and transparency, the content of the photopolymerization initiator is preferably 0.1% by mass or more and 15.0% by mass or less, more preferably 1.0% by mass or more and 12.0% by mass or less, and still more preferably 2.0% by mass or more and 10.0% by mass or less, based on the total amount of the nonvolatile components in the resin composition.

(other Components)

The resin composition according to the present invention may contain an ultraviolet-curable resin other than the above ultraviolet-curable urethane (meth) acrylate resin, a (meth) acrylate monomer, a thermoplastic resin, or other components other than a photopolymerization initiator, within a range not impairing the object of the present invention. As other components, an antistatic agent, a polymerization inhibitor, a non-reactive diluent, a delustering agent, an antifoaming agent, a dispersant, an anti-settling agent, a leveling agent, a dispersant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, an adhesion improver, a photosensitizer, an antibacterial agent, an antifungal agent, an antiviral agent, a silane coupling agent, a plasticizer, and the like may be added as necessary.

< method for producing resin composition >

The resin composition according to the present invention is obtained by mixing and stirring the above components using a conventionally known apparatus such as a mixer, a disperser, or a stirrer. Examples of such a device include a mixing/dispersing mill, a homogenizing/dispersing machine, a mortar mixer, a roll mill, a paint mixer, and a homogenizer.

The viscosity of the resin composition (resin solution) at 25 ℃ is preferably 100 to 3,000 mPas, more preferably 500 to 2,000 mPas, and still more preferably 700 to 1,500 mPas. The viscosity can be measured using a B-type viscometer. When the viscosity is within the above numerical range, the processability is excellent.

In the present invention, the resin composition may be diluted with a solvent as necessary to adjust the viscosity and the like suitable for application. The solvent is not particularly limited as long as it dissolves the resin component in the resin composition. Specific examples thereof include aromatic hydrocarbons (e.g., toluene, xylene, and ethylbenzene), esters or ether esters (e.g., ethyl acetate, butyl acetate, and methoxybutyl acetate), ethers (e.g., diethyl ether, tetrahydrofuran, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and diethylene glycol monoethyl ether), ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, di-N-butyl ketone, and cyclohexanone), alcohols (e.g., methanol, ethanol, N-propanol, or isopropanol, N-butanol, isobutanol, sec-butanol, or tert-butanol, 2-ethylhexanol, and benzyl alcohol), amides (e.g., dimethylformamide, dimethylacetamide, and N-methylpyrrolidone), sulfoxides (e.g., dimethyl sulfoxide), water, and mixed solvents of 2 or more of these.

(curing coating film)

The haze measured according to JIS K7136 for the cured coating film formed from the resin composition according to the present invention is preferably less than 1%, more preferably 0.7% or less, and further preferably 0.5% or less in the case of a thickness of 3 μm. The total light transmittance of the cured coating film having a thickness of 3 μm measured according to JIS K7361-1 is preferably 90% or more, more preferably 91% or more. When the haze and the total light transmittance are within the above ranges, the transparency is excellent.

The cured coating film formed from the resin composition according to the present invention has a stretchability measured at room temperature of preferably 100% or more, more preferably 115% or more, further preferably 130% or more, and further more preferably 140% or more, in the case of a thickness of 3 μm. When the value of stretchability is within the above range, the stretchability is excellent, and the composition can be suitably used as a coating material for a decorative film for in-mold molding. The detailed measurement method for stretchability is as described later.

The water contact angle of the cured coating film formed from the resin composition according to the present invention is preferably 90 ° or more, more preferably 95 ° or more, and further preferably 100 ° or more. When the water contact angle is within the above range, the water repellency is excellent and the stain resistance can be improved.

The cured coating film formed from the resin composition according to the present invention preferably has a difference in water contact angle of less than 10 °, more preferably less than 7 °, further preferably less than 5 °, and further more preferably less than 3 ° before and after a wet heat resistance test at a temperature of 85 ℃, a humidity of 85% RH, and 500 hours. If the value of the difference in water contact angle between before and after the wet heat resistance test is within the above range, the wet heat resistance is excellent and the antifouling property can be maintained for a long period of time.

< substrate with coating film >

The substrate with a coating film according to the present invention has the above-described cured coating film on the substrate. A schematic cross-sectional view of a coated substrate according to the present invention is shown in fig. 1. The substrate 10 with a coating film shown in fig. 1 has a cured coating film 12 on one surface of a substrate 11.

The substrate of the substrate with a coating film according to the present invention is not particularly limited, and conventionally known substrates can be used. For example, when the substrate with a coating film is a decorative film for in-mold molding, a thermoplastic resin film such as a polyester film, a polyolefin film, a nylon film, a polycarbonate film, or a polymethyl methacrylate film can be used as the substrate.

The cured coating film in the substrate with a coating film according to the present invention is suitable as an outermost protective layer in applications requiring multilayer coating.

The substrate with a coating film according to the present invention may further comprise another layer in applications where multi-layer coating is required. For example, the substrate with a coating film according to the present invention may be provided with another layer between the substrate and the cured coating film. Examples of other layers in the substrate with a coating film according to the present invention include an intermediate coating layer and an undercoat layer. The other layers may be constituted of only 1 layer or may be constituted of a plurality of layers.

< method for producing substrate with coating film >

The substrate with a coating film according to the present invention comprises the following steps:

a coating step of coating the resin composition on at least one surface of a base material; and

and a curing step of curing the resin composition by ultraviolet irradiation after the coating step to form a cured coating film.

Hereinafter, each step will be described in detail.

(coating Process)

The coating step is a step of coating the resin composition on one surface of the substrate by a conventionally known method. For coating, a coater such as a bar coater, a gravure coater, a roll coater (a natural roll coater, a reverse roll coater, etc.), an air knife coater, a spin coater, a blade coater, etc. may be used. Among them, a coating method using a gravure coater is preferable from the viewpoint of workability and productivity.

The coating thickness is preferably 0.5 to 50 μm after curing and drying. From the viewpoint of drying properties and curability, a more preferable upper limit is 30 μm, and from the viewpoint of water resistance and chemical resistance, a more preferable lower limit is 1 μm.

When the resin composition is diluted with a solvent and used, it is preferably dried after coating. Examples of the drying method include hot air drying (hair dryer, etc.). The drying temperature is preferably 10 to 200 ℃, and from the viewpoint of smoothness and appearance of the coating film, a more preferable upper limit is 150 ℃, and from the viewpoint of drying speed, a more preferable lower limit is 30 ℃.

(curing step)

The curing step is a step of irradiating the coated surface of the substrate with ultraviolet rays to cure the coated resin composition and form a cured coating film. Examples of the method of curing with ultraviolet rays include a method of irradiating ultraviolet rays using a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a UV-LED, or the like that emits light in a wavelength region of 200 to 500 nm. The amount of ultraviolet radiation is excellent from the viewpoints of curability of the resin composition and flexibility of the cured productIs selected to be 100 to 3,000mJ/cm²More preferably 200 to 1,000mJ/cm²。

Examples

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples.

< Synthesis of ultraviolet-curable urethane (meth) acrylate resin >

First, the following raw materials were prepared for synthesis of an ultraviolet-curable urethane (meth) acrylate resin.

(A) The components: isophorone diisocyanate

(B) The components: ethylene glycol

(C) The components: pentaerythritol triacrylate (hydroxyl number 280)

(D1) The components: reactive oligomer having hydroxyl group and fluorine-containing group (trade name: Ftergent 710FM, 50% by mass of nonvolatile component, manufactured by Neos)

(D2) The components: reactive oligomer having hydroxyl group, fluorine-containing group, and ultraviolet-reactive group (trade name: Ftergent 601ADH2, non-volatile component: 25% by mass, manufactured by Neos)

(D3) The components: oligomer containing hydroxyl group, fluorine-containing group, and lipophilic group (product name: Megaface F-576, non-volatile component: 100% by mass, manufactured by D1C Co.)

(D4) The components: oligomer having hydroxyl group, fluorine-containing group and lipophilic group (product name: Megaface F-561, manufactured by D1C Co., Ltd.; nonvolatile component: 100% by mass)

Other components: hydroxyl group-containing polydimethylsiloxane (product name: PROTECT 5000N, non-volatile component: 100% by mass, manufactured by TEGO Co., Ltd.)

111g of isophorone diisocyanate, 21.7g of ethylene glycol, 98.4g of methyl ethyl ketone, and 0.389g of dibutyltin dilaurate were put into a four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and reacted in an oil bath for 1 hour while raising the temperature to 70 ℃. Then, 5.9g of a reactive oligomer (Ftergent 710FM) having a hydroxyl group and a fluorine-containing group was added thereto and reacted for 1 hour. Then, 64g of a mixture of (meth) acrylate compounds, 0.02g of 4-methoxyphenol, and 0.06g of dibutylhydroxytoluene were added thereto, and the mixture was heated to 80 ℃ with an oil bath to react for 4 hours. The end point of the reaction was confirmed by disappearance of the peak derived from the isocyanate group in the infrared absorption analysis. After the reaction was completed, 98.4g of propylene glycol monomethyl ether was added to obtain a resin solution containing a fluorine-containing urethane acrylate resin (2).

Resin solutions containing ultraviolet-curable urethane (meth) acrylate resins (1), (3) to (9) were obtained in the same manner as in example 1, except that the respective components were reacted in accordance with the compounding described in table 1.

< evaluation of ultraviolet-curable urethane (meth) acrylate resin >

(weight average molecular weight)

The ultraviolet-curable urethane (meth) acrylate resins (1) to (9) synthesized as described above were measured by gel permeation chromatography under the following measurement conditions, and the measurement results are shown in table 1.

[ measurement conditions ]

An apparatus: "HLC-8220" (manufactured by Tosoh corporation)

Column chromatography: 1 of "TSKgel Super H4000" was connected to 2 of "TSKgel Super H2000" (all manufactured by Tosoh Co., Ltd., inner diameter: 6 mm. times. length: 15cm)

Eluent: tetrahydrofuran 99% (stabilized with BHT)

Flow rate: 0.5mL/min

The detector: differential Refractometer (RI) incorporated in HLC-8220 device

Column oven temperature: 40 deg.C

Standard substance: standard polystyrene

Sample preparation method: measuring the resin solution containing the resins (1) - (9) to a sample tube, adding tetrahydrofuran, and diluting to about 100 times

(viscosity)

The viscosity of the resin solutions containing the ultraviolet-curable urethane (meth) acrylate resins (1) to (9) synthesized as described above was measured under the following measurement conditions. The measurement results are shown in table 1.

[ measurement conditions ]

An apparatus: TV-22 type viscometer (east China machine industry system)

Using a rotor: 1 ℃ 34' XR 24

Rotor speed: 20rpm

Measurement temperature: 25 deg.C

(non-volatile component)

The resin solutions containing the ultraviolet-curable urethane (meth) acrylate resins (1) to (9) synthesized as described above were allowed to stand at 160 ℃ for 1 hour using a model VTFP-64-1S (manufactured by Isuzu), and the nonvolatile content (%) was measured from the mass difference between before and after the test. The measurement results are shown in table 1.

< preparation of ultraviolet-curable resin composition >

[ examples 1 to 7]

To 32.0 parts by mass of methyl ethyl ketone, 65.0 parts by mass of any of the ultraviolet-curable urethane (meth) acrylate Resins (2) to (8) shown in Table 2 and 3.0 parts by mass of a photopolymerization initiator (product name: Omnirad 184, manufactured by IGM Resins) were added and dissolved to obtain an ultraviolet-curable resin composition.

Comparative example 1

To 32.0 parts by mass of methyl ethyl ketone were added 65.0 parts by mass of an ultraviolet-curable urethane (meth) acrylate resin (1) and 3.0 parts by mass of a photopolymerization initiator (product name: Omnirad 184, manufactured by IGM Resins) to dissolve them, thereby obtaining an ultraviolet-curable resin composition.

[ comparative examples 2 to 5]

An ultraviolet-curable urethane (meth) acrylate resin (1) in an amount of 65.0 parts by mass, a photopolymerization initiator (product name: Omnirad 184, manufactured by IGM Resins) in an amount of 3.0 parts by mass, and a fluorine-based additive (reactive oligomer containing a hydroxyl group and a fluorine-containing group, manufactured by Neos, product name: Ftergent 710FM) in an amount of table 2 were added to methyl ethyl ketone in an amount of table 2, and dissolved to obtain an ultraviolet-curable resin composition.

Comparative example 6

To 32.0 parts by mass of methyl ethyl ketone were added 65.0 parts by mass of an ultraviolet-curable urethane (meth) acrylate resin (9) and 3.0 parts by mass of a photopolymerization initiator (product name: Omnirad 184, manufactured by IGM Resins Co., Ltd.) to dissolve them, thereby obtaining an ultraviolet-curable resin composition.

Production of substrate with coating film

Examples 1 to 7 and comparative examples 1 to 6

Each of the ultraviolet-curable urethane (meth) acrylate resins prepared in examples 1 to 7 and comparative examples 1 to 6 was coated 1 time on a PET film (product name: Cosmosine A4300, manufactured by Toyo Co., Ltd.) so that the dry film thickness became about 3 μm. Next, ultraviolet light was irradiated using a high-pressure mercury lamp (irradiation dose: 300 mJ/cm)²) The coating film is cured to form a cured coating film, thereby obtaining a substrate with a coating film.

< evaluation of Properties >

(appearance of coating film)

The state of the coating film of the substrate with the coating film produced above was visually confirmed. The appearance of the coating film was judged from the results of the confirmation according to the following criteria. The results of the determination are shown in Table 3.

[ judgment standards ]

Good: is good.

X: the leveling property was poor.

(optical Properties)

The substrate with a coating film produced as described above was measured for Haze (HZ) according to JIS K7136 and for total light transmittance (TT) according to JIS K7361-1 using a haze meter (model: NDH 4000, manufactured by Nippon Denshoku industries Co., Ltd.). The measurement results are shown in Table 3. In addition, the optical characteristics are determined according to the following criteria.

[ HZ determination criterion ]

Good: less than 1%.

X: is more than 1 percent.

[ TT criterion ]

Good: is more than 90 percent.

X: less than 90%.

(stretchability)

The substrate with a coating film produced as described above was prepared into a test piece in the form of a strip of 15mm × l50 mm. Next, the test piece was stretched at room temperature by a tensile tester (EZ-L, model manufactured by Shimadzu corporation) under the conditions of (distance between chucks: 100mm, tensile rate: 10 mm/min), and the tensile rate until cracks were generated in the coating film was visually measured. The measurement results are shown in Table 3. In addition, stretchability was judged according to the following criteria.

[ judgment standards ]

Very good: is 130% or more.

Good: is 100% or more and less than 130%.

X: less than 100%.

(Water-repellency)

The substrate with a coating film produced as described above was measured for water contact angle using a contact angle meter (model: DropMaster DM500, manufactured by Kyowa Kagaku K.K.). In the measurement, 1. mu.L of pure water was dropped, and the value after 10 seconds was confirmed. The measurement results are shown in Table 3. The water repellency was determined according to the following criteria.

[ judgment standards ]

Very good: is more than 100 degrees.

Good: is 90 DEG or more and less than 100 deg.

X: less than 90.

(Water repellency after Wet Heat resistance test)

The substrate with the coating film thus produced was allowed to stand in a cryostat (manufactured by himlex NEO FX420N) set at a temperature of 85 ℃ and a humidity of 85% RH for 500 hours, and then a test piece was taken out. The water contact angle of the test piece taken out was measured by using a contact angle meter (model: DropMaster DM500, manufactured by Kyowa Kagaku K.K.). In the measurement, 1. mu.L of pure water was dropped, and the value after 10 seconds was confirmed. The measurement results and the difference in water contact angle between before and after the wet heat resistance test are shown in Table 3. The water repellency after the wet heat resistance test was determined according to the following criteria.

[ judgment standards ]

Good: the difference in water contact angle between before and after the moist heat resistance test is less than 5 °.

And (delta): the difference in water contact angle between before and after the moist heat resistance test is 5 DEG or more and less than 10 deg.

X: the difference in water contact angle between before and after the moist heat resistance test is 10 DEG or more.

(chemical resistance)

0.5g of sunscreen cream (SPF45) made by Neutrogena was applied to the substrate with the coating film prepared above in an area of 5 cm. times.5 cm. Subsequently, the film was left standing at 80 ℃ for 4 hours, and then washed, and the state of the coating film was visually checked. The result of the confirmation is determined according to the criteria described below. The results of the determination are shown in Table 3.

[ judgment standards ]

Good: there is no anomaly.

X: whitening or bubbling occurs.

[ Table 1]

[ Table 2]

[ Table 3]

Description of the reference numerals

11 base material with coating film

12 base material

13 curing the coating film.