JP2014214270A - Curable resin composition, and cured film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable resin composition and a cured film which have such flexibility as to be capable of following deformation of three-dimensional machining, and have excellent coating film appearance, scratch resistance, contamination resistance, abrasion resistance, mechanical strength and the like.SOLUTION: A curable resin composition contains an urethane (meth)acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C): (A) a polyisocyanate compound having an alicyclic structure; (B) a chain aliphatic diol compound having 8 to 16 carbon atoms; and (C) hydroxyalkyl (meth)acrylate, and an organic solvent. The compound (B) is used in an amount of 40 wt.% or more based on total diol components.

Description

  The present invention has a flexibility capable of following the deformation during three-dimensional processing, and is excellent in coating film appearance, scratch resistance, contamination resistance, abrasion resistance, mechanical strength, and the like, and curing Relates to the membrane.

  A radical polymerization type curable resin composition can be cured in a short time by irradiation with active energy rays, and can provide a film or a molded product excellent in chemical resistance, stain resistance, weather resistance, heat resistance, etc. Since it can be used, it is widely used in various surface processing fields and cast molding applications. Among such curable resin compositions, from the viewpoint of curability and work efficiency, after manufacturing a cured film obtained by previously curing a resin composition containing polyurethane acrylate with active energy rays, and after performing a surface processing treatment, etc. A method of performing three-dimensional processing at room temperature or under heating conditions is used, and in this case, the cured film needs to have flexibility to follow the deformation during three-dimensional processing.

  Patent Document 1 discloses urethane as a reaction product of polyisocyanate, diol having an alicyclic structure, and hydroxyalkyl (meth) acrylate as a curable resin composition having such flexibility and excellent stain resistance. A (meth) acrylate oligomer curable resin composition is disclosed.

JP 2010-222568 A

  According to the detailed study by the present inventors, in the curable resin composition described in Patent Document 1, any one of coating film appearance, scratch resistance, stain resistance, abrasion resistance, and mechanical strength can be used. However, a sufficiently excellent curable resin composition has not been obtained, and in particular, a problem has been found that the scratch resistance and wear resistance are insufficient. That is, the problem of the present invention is that it has flexibility to follow the deformation of three-dimensional processing, and has excellent curable properties such as coating film appearance, scratch resistance, stain resistance, abrasion resistance, mechanical strength, etc. The object is to provide a resin composition and a cured film.

  As a result of intensive studies to solve the above problems, the present inventors have found that the curable resin composition containing a urethane (meth) acrylate oligomer obtained using a specific raw material and an organic solvent has the above problems. The inventors have found that this can be solved, and have reached the present invention. That is, the gist of the present invention resides in the following [1] to [7].

[1] A curable resin composition comprising a urethane (meth) acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C) and an organic solvent, wherein the compound (B ) Is used in an amount of 40% by weight or more of the total diol component.
Compound (A): Polyisocyanate compound having alicyclic structure (B): Chain aliphatic diol compound having 8 to 16 carbon atoms (C): Hydroxyalkyl (meth) acrylate

[2] The curable resin composition according to [1], wherein the urethane (meth) acrylate has a number average molecular weight (Mv) of 500 to 15,000.

[3] The curable resin composition according to [1] or [2], which contains a linear aliphatic diol having 8 to 16 carbon atoms as the compound (B).

[4] The curable resin composition according to any one of [1] to [3], which contains hydroxyalkyl poly (meth) acrylate as the compound (C).

[5] The curable resin composition according to any one of [1] to [4], wherein a solubility parameter of the organic solvent is 8.0 to 11.5.

[6] The urethane (meth) acrylate oligomer is obtained by reacting the compound (A) with the compound (B) to obtain a urethane prepolymer, and then reacting the compound (C) with the urethane prepolymer. The curable resin composition according to any one of [1] to [5].

[7] A cured film obtained by irradiating the curable resin composition according to any one of [1] to [6] with active energy rays.

  According to the present invention, a curable resin composition having flexibility capable of following deformation during three-dimensional processing and excellent in coating film appearance, scratch resistance, contamination resistance, abrasion resistance, mechanical strength, and the like. And a cured film is provided.

  Embodiments of the present invention will be described in detail below, but the following descriptions are representative examples of embodiments of the present invention, and the present invention is not limited to these contents. In the present invention, “(meth) acrylate” is a general term for acrylate and methacrylate, and means one or both of acrylate and methacrylate. About “(meth) acryloyl” and “(meth) acryl” Is the same. Further, in the present invention, “to” is used in the sense of including numerical values described before and after it as a lower limit value and an upper limit value.

[Curable resin composition]
The curable resin composition of the present invention is a curable resin composition containing a urethane (meth) acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C) and an organic solvent. The compound (B) is used in an amount of 40% by weight or more based on the total diol component.
Compound (A): Polyisocyanate compound having alicyclic structure (B): Chain aliphatic diol compound having 8 to 16 carbon atoms (C): Hydroxyalkyl (meth) acrylate

The curable resin composition of the present invention has flexibility capable of following deformation during three-dimensional processing, and is excellent in coating film appearance, scratch resistance, contamination resistance, abrasion resistance, mechanical strength, and the like. Compared with the curable resin composition described in Patent Document 1, the scratch resistance and the wear resistance are particularly excellent. The reason why the curable resin composition of the present invention exhibits the excellent effects as described above is not clear, but particularly the scratch resistance and wear resistance are considered to be due to the following reasons. When two or more molecules of urethane (meth) acrylate oligomers as described in Patent Document 1 are gathered, hydrogen bonds derived from urethane bonds are formed between the molecules, and hardness and rigidity are obtained, but it becomes brittle. The urethane (meth) acrylate oligomer used in the present invention is disadvantageous in that the slipping property is lowered, but by using an aliphatic diol having a long chain length (8 to 16 carbon atoms) as the compound (B) used as a raw material, It is considered that the distance between urethane bonds in the molecule is increased, brittleness due to intermolecular hydrogen bonds is eliminated, and a cured film that maintains hardness while maintaining appropriate flexibility is formed.

<Urethane (meth) acrylate oligomer>
The urethane (meth) acrylate oligomer used in the curable resin composition of the present invention uses at least the following compound (A), compound (B) and compound (C), and uses the compound (B) as a raw material. It is obtained using 40% by weight or more of the diol component.

[Compound (A)]
The compound (A) used in the present invention is a polyisocyanate having an alicyclic structure. The polyisocyanate having an alicyclic structure is a compound having an alicyclic structure and a total of two or more substituents containing an isocyanate group and / or an isocyanate group in one molecule. As the compound (A), one type may be used, or two or more types may be used. In the present invention, the isocyanate group and the substituent containing the isocyanate group may be collectively referred to as “isocyanate groups”. In the compound (A), the isocyanate groups may be the same or different.

  As a substituent containing an isocyanate group, a C1-C5 alkyl group, a C1-C5 alkenyl group, or a C1-C5 alkoxyl group containing 1 or more isocyanate groups is mentioned, for example. Among these, an alkyl group having 1 to 5 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is particularly preferable.

  Although the alicyclic structure in a compound (A) is not specifically limited, It is preferable that it is C5-C15, and it is more preferable that it is C6 or more. Moreover, it is more preferable that it is C14 or less, and it is especially preferable that it is C13 or less. Furthermore, the alicyclic structure is preferably a cycloalkylene group. Examples of the polyisocyanate having an alicyclic structure include diisocyanates having an alicyclic structure such as bis (isocyanate methyl) cyclohexane, cyclohexane diisocyanate, bis (isocyanatocyclohexyl) methane, and isophorone diisocyanate, and tris (isocyanate isophorone) isocyanurate. And triisocyanate having an alicyclic structure. Among these, it is preferable that the compound (A) contains isophorone diisocyanate.

  The number average molecular weight of the compound (A) is preferably 100 or more, and preferably 150 or more, from the viewpoint of the balance between strength and elastic modulus as a cured film obtained by curing the curable resin composition. More preferably, it is preferably 1,000 or less, and more preferably 500 or less. The number average molecular weight of the polyisocyanate is obtained from a calculated value from a chemical formula in the case of a polyisocyanate composed of a single monomer, or a calculated value from NCO% in the case of a polyisocyanate composed of two or more monomers. be able to.

[Compound (B)]
The compound (B) used in the present invention is a chain aliphatic diol having 8 to 16 carbon atoms. The chain structure in the compound (B) may be linear or branched.

Examples of the compound (B) include 1,8-octanediol, 1,9-nonanediol, 1-10 decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,14-tetracandiol, C8-16 linear aliphatic diol such as 1,16-hexadecanediol; carbon number such as 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol Examples thereof include 8 to 16 branched aliphatic diols. Among these, a linear aliphatic diol having 8 to 16 carbon atoms is preferable because a curable resin composition having excellent hardness and stain resistance can be obtained. Among these, 1,12 as the compound (B) is preferable. -It preferably contains dodecanediol.

  In the present invention, the compound (B) is used in an amount of 40% by weight or more based on the total diol component used as a raw material for the urethane (meth) acrylate oligomer. The use of compound (B) at 40% by weight or more is important from the viewpoint of improving the hardness and mechanical strength of the cured film. In order to further enhance this effect, the compound (B) is preferably 60% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more, and the upper limit is 100% by weight. %.

[Compound (C)]
The hydroxyalkyl (meth) acrylate of the compound (C) used in the present invention is a compound having one or more hydroxyl groups, one or more (meth) acryloyl groups, and a hydrocarbon group. Here, the hydrocarbon group of the hydroxyalkyl (meth) acrylate is preferably a hydrocarbon group having 1 to 30 carbon atoms, more preferably a hydrocarbon group having 1 to 15 carbon atoms, and 2 to 2 carbon atoms. The hydrocarbon group is more preferably 10 hydrocarbon groups, and particularly preferably a hydrocarbon group having 2 to 8 carbon atoms.

  Examples of the compound (C) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, cyclohexanedimethanol mono ( (Meth) acrylate, addition reaction product of 2-hydroxyethyl (meth) acrylate and caprolactone, addition reaction product of 4-hydroxybutyl (meth) acrylate and caprolactone, addition reaction product of glycidyl ether and (meth) acrylic acid, Examples include glycol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol penta (meth) acrylate.

  Among these, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol A hydroxyalkyl (meth) acrylate having an alkylene group having 2 to 4 carbon atoms between a (meth) acryloyl group such as penta (meth) acrylate and a hydroxyl group is particularly preferable from the viewpoint of mechanical strength of the resulting cured film. In particular, hydroxyalkyl poly (meth) having two or more (meth) acryloyl groups such as pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc. Acrylate is particularly preferred. Hydroxyalkyl poly (meth) acrylate has a good cross-linking structure due to the involvement of multiple (meth) acryloyl groups in the effective reaction when obtaining a cured film, coating appearance, scratch resistance, abrasion resistance, etc. The physical properties of can be improved.

  The molecular weight of the compound (C) is preferably 40 or more, more preferably 80 or more. On the other hand, the molecular weight of the compound (C) is preferably 800 or less, and more preferably 400 or less, from the viewpoint of the mechanical strength of the obtained cured film. In addition, when the compound (C) is the above addition reactant or polymer, the molecular weight means a number average molecular weight by gel permeation chromatography measurement (GPC measurement).

[Other raw material compounds]
In the raw material compound of the urethane (meth) acrylate oligomer used in the present invention, other raw material compounds other than the compound (A), the compound (B) and the compound (C) are used as long as the effects of the present invention are not significantly impaired. Also good. Examples of such other raw material compounds include, for example, chain aliphatic polyisocyanate, aromatic polyisocyanate, chain aliphatic diol having 1 to 7 carbon atoms, diol having an alicyclic structure, polyalkylene glycol, and the like. High molecular weight polyols (hereinafter referred to as “other high molecular weight polyols”), chain extenders and the like.

  A chain aliphatic polyisocyanate is a compound having a chain aliphatic structure and two or more isocyanate groups bonded thereto. A chain aliphatic polyisocyanate is preferable from the viewpoint of enhancing the weather resistance of a cured film obtained by curing the curable resin composition and imparting flexibility. The chain aliphatic structure in the chain aliphatic polyisocyanate is not particularly limited, but is preferably a linear or branched alkylene group having 1 to 6 carbon atoms. Examples of such aliphatic polyisocyanates include aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate, and aliphatic triisocyanates such as tris (isocyanatohexyl) isocyanurate. Can be mentioned. These may be used alone or in combination of two or more.

  An aromatic polyisocyanate is a compound having an aromatic structure and two or more isocyanate groups bonded thereto. Although the aromatic structure in aromatic polyisocyanate is not specifically limited, It is preferable that it is a C6-C13 bivalent aromatic group. Examples of such aromatic polyisocyanates include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, and naphthalene diisocyanate. The aromatic polyisocyanate is preferable from the viewpoint of increasing the mechanical strength of a cured film obtained by curing the curable resin composition. Examples of such aromatic polyisocyanate include tolylene diisocyanate and diphenylmethane diisocyanate. These may be used alone or in combination of two or more.

  Examples of the chain aliphatic diol having 1 to 7 carbon atoms include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7- And heptanediol. These may be used alone or in combination of two or more.

  Examples of the diol having an alicyclic structure include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. These may be used alone or in combination of two or more.

  Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol and the like. These may be used alone or in combination of two or more.

  Examples of other high molecular weight polyols include polyether diol, polyester diol, polyether ester diol, polyolefin polyol, and silicon polyol. These may be used alone or in combination of two or more.

A chain extender is a compound having two or more active hydrogens that react with isocyanate groups. Examples of the chain extender include low molecular weight diamine compounds having a number average molecular weight of less than 500, and examples include aromatics such as 2,4- or 2,6-tolylenediamine, xylylenediamine, and 4,4′-diphenylmethanediamine. Group diamine; ethylenediamine, 1,2-propylenediamine, 1,6-hexanediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, 2,2,4- or Aliphatic diamines such as 2,4,4-trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine; And 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4′-dicyclohexylmethane Min, isopropylidene cyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1,3-bis-aminomethyl cyclohexane, alicyclic diamines such as tricyclodecane diamine. These may be used alone or in combination of two or more.

[Physical properties of urethane (meth) acrylate oligomer]
The number average molecular weight (Mv) of the urethane (meth) acrylate oligomer is preferably 500 or more, more preferably 1,000 or more, still more preferably 2,000 or more, while 15,000 or less. Preferably, it is 10,000 or less, more preferably 6,000 or less. When the number average molecular weight of the urethane (meth) acrylate oligomer is not less than the above lower limit, the three-dimensional processability of the resulting cured film tends to be good. When the number average molecular weight of the urethane (meth) acrylate oligomer is not more than the above upper limit, the stain resistance of the cured film obtained from the curable resin composition tends to be good. The number average molecular weight of the urethane (meth) acrylate oligomer is related to the distance between the crosslinking points. The lower the number average molecular weight, the shorter the distance between the crosslinking points, and the larger the number average molecular weight, the longer the distance between the crosslinking points. Tend to be. The reason why the number average molecular weight affects the three-dimensional processing suitability and the stain resistance is that when the distance between the cross-linking points is long, the structure becomes flexible and easily stretched, and the three-dimensional workability is excellent. This is presumed to be due to the structure and excellent scratch resistance, stain resistance, and wear resistance. In addition, a urethane (meth) acrylate oligomer number average molecular weight can be calculated | required by gel permeation chromatography measurement (GPC measurement), and a more detailed measuring method is shown in the below-mentioned Example.

  The urethane bond amount of the urethane (meth) acrylate oligomer is preferably 10 to 30% by weight, more preferably 15 to 25% by weight. When the amount of urethane bonds is not less than the above lower limit value, mechanical strength and stain resistance tend to be improved, and when it is not more than the above upper limit value, elongation tends to be improved. In addition, said urethane bond amount is controllable by adjusting the raw material mixing | blending of a urethane (meth) acrylate oligomer.

  In the present invention, the urethane bond amount is calculated as follows. The urethane (meth) acrylate oligomer used in the present invention uses a polyisocyanate of the compound (A), a chain diol having 8 to 12 carbon atoms of the compound (B), and a hydroxyalkyl (meth) acrylate of the compound (C) as raw materials. The constituent unit in the urethane (meth) acrylate oligomer obtained can be regarded as the raw material composition used is kept as it is. From this, the total amount of urethane bonds (the total number of moles of polyisocyanate and the molecular weight of urethane bonds) in the total amount of components of the urethane (meth) acrylate oligomer (the sum of the product of the molar ratio of each raw material component and the molecular weight of each component) (The product of (59)).

[Method for producing urethane (meth) acrylate oligomer]
The urethane (meth) acrylate oligomer used in the present invention can be produced by subjecting the compound (A) to the addition reaction of the compound (B) and the compound (C). Further, the charging ratio of each raw material compound at that time is usually substantially the same as or the same as the composition of the target urethane (meth) acrylate oligomer.

These addition reactions can be carried out using any of the known methods for producing urethane (meth) acrylate oligomers. Examples of such a method include the following methods (1) to (3).
(1) The compound (A) and the compound (B) are reacted under conditions such that the isocyanate group becomes excessive to obtain a urethane prepolymer having an isocyanate terminal, and then the urethane prepolymer having the isocyanate terminal And a method of reacting the compound (C).
(2) A method in which all raw material compounds are added simultaneously and reacted.
(3) obtained by reacting the compound (A) with the compound (C) first and synthesizing a urethane (meth) acrylate prepolymer having a (meth) acryloyl group and an isocyanate group in the molecule at the same time. A method of reacting the prepolymer with compound (B).

  Among these, according to the method (1), the urethane prepolymer can be obtained by urethanizing the compound (A) with the compound (B). The target urethane (meth) acrylate oligomer has a structure obtained by urethanation reaction between the urethane prepolymer having an isocyanate group at the terminal and the compound (C). The method (1) is preferred because the molecular weight can be easily controlled, and a (meth) acryloyl group can be introduced at both ends, so that a cured film can be easily obtained.

  The amount of all isocyanate groups in the urethane (meth) acrylate oligomer and the amount of all functional groups that react with isocyanate groups such as hydroxyl groups and amino groups are usually theoretically equimolar. For this reason, the amount of the compound (A), compound (B), compound (C) and other raw material compounds used as raw materials is the amount of all isocyanate groups in the urethane (meth) acrylate oligomer and the total functional groups that react with it. The amount is an amount that is 50 to 200 mol% in terms of equimolar or mol% of the total functional group relative to the isocyanate group.

  When producing a urethane (meth) acrylate oligomer, the amount of the compound (C) used is 3 mol% with respect to the total amount of the compound containing functional groups that react with isocyanate in the compound (C) and other raw materials. The above is preferable, 5 mol% or more is more preferable, on the other hand, 70 mol% or less is preferable, 50 mol% or less is more preferable, and 30 mol% or less is particularly preferable. By this ratio, the molecular weight of the obtained urethane (meth) acrylate oligomer can be controlled. When the proportion of the compound (C) is large, the molecular weight of the urethane (meth) acrylate oligomer tends to be small, and when the proportion is small, the molecular weight tends to be large.

  Further, when a chain extender is used, the compound (B), a diol component other than the compound (B), and all polyols of other polyol components (compounds having two or more alcoholic hydroxyl groups), a chain extender, Is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, based on the total amount of the compounds used. It is particularly preferable that the amount be 95 mol% or more. When the total polyol amount is not less than the lower limit, the stability of the curable resin composition tends to be improved.

  In addition, said raw material ratio becomes a standard at the time of manufacturing a urethane (meth) acrylate oligomer. Actually, it is preferable to finely adjust the raw material blending ratio in the above range depending on the desired physical properties.

In the production of the urethane (meth) acrylate oligomer, an organic solvent can be used for the purpose of adjusting the viscosity. An organic solvent may be used individually by 1 type, and 2 or more types may be mixed and used for it. As the organic solvent, any known organic solvent can be used as long as the effects of the present invention are obtained. Preferable organic solvents include toluene, xylene, ethyl acetate, butyl acetate, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, N-methylpyrrolidone and the like. The organic solvent can be used usually at 300 parts by weight or less with respect to 100 parts by weight of the solid content in the reaction system.

  In the production of the urethane (meth) acrylate oligomer, the total content of the urethane (meth) acrylate oligomer to be produced and its raw material compound is preferably 20% by weight or more, more preferably 40% by weight or more based on the total amount of the reaction system. More preferably. The upper limit of the total content is usually 100% by weight. It is preferable for the total content of the urethane (meth) acrylate oligomer and its raw material compounds to be at least the above lower limit value because the reaction rate tends to increase and the production efficiency tends to improve.

  A catalyst can be used in the production of the urethane (meth) acrylate oligomer. The catalyst can be selected from the range in which the effects of the present invention can be obtained. For example, tin-based catalysts such as dibutyltin laurate, dibutyltin dioctoate, dioctyltin dilaurate, and dioctyltin dioctoate; bismuth tris (2- Examples thereof include bismuth-based catalysts such as ethyl hexanoate 9. The catalyst may be used alone or in combination of two or more, among which dioctyltin dilaurate is used. , Bismuth tris (2-ethylhexanoate) is preferable from the viewpoint of environmental adaptability, catalytic activity, storage stability, etc. The amount of the catalyst used has an upper limit with respect to the total content of the raw material compounds. Usually 2,000 ppm or less, preferably 1,000 ppm or less, and the lower limit is usually 10 ppm or more, preferably 30 ppm or less. In addition, when manufacturing by the method of said (1), especially the said compound (A) and the reaction which makes a compound (B) react, and obtains a urethane prepolymer, and said compound with respect to a urethane prepolymer It is preferable to use the catalyst in both reactions when (C) is subjected to an addition reaction.

  Moreover, when using the compound which contains a (meth) acryloyl group like a compound (C) at the time of manufacture of a urethane (meth) acrylate oligomer, it is preferable to use a polymerization inhibitor together. Examples of such a polymerization inhibitor include phenols such as hydroquinone, methylhydroquinone, hydroquinone monoethyl ether, dibutylhydroxytoluene, amines such as phenothiazine and diphenylamine, copper salts such as copper dibutyldithiocarbamate, and manganese acetate. Manganese salts, nitro compounds, nitroso compounds and the like can be mentioned. A polymerization inhibitor may be used individually by 1 type, and 2 or more types may be mixed and used for it. Of these, phenols are preferable as the polymerization inhibitor. The amount of the polymerization inhibitor used is usually 3,000 ppm or less, preferably 1,000 ppm or less, particularly preferably 500 ppm or less, while the lower limit is usually 50 ppm, based on the total content of the raw material compounds. Above, preferably 100 ppm or more.

  In the production of the urethane (meth) acrylate oligomer, the reaction temperature is preferably 20 ° C. or higher, preferably 40 ° C. or higher, and more preferably 60 ° C. or higher. It is preferable for the reaction temperature to be at least the above lower limit value because the reaction rate increases and the production efficiency tends to improve. The reaction temperature is preferably 120 ° C. or lower, more preferably 100 ° C. or lower. It is preferable for the reaction temperature to be equal to or lower than the above upper limit value because side reactions such as an allohanato reaction hardly occur. When the reaction system contains an organic solvent, the reaction temperature is preferably not higher than the boiling point of the organic solvent. When a compound having a (meth) acryloyl group such as compound (C) is contained, ) It is preferable that it is 70 degrees C or less from a viewpoint of preventing that an acryloyl group reacts excessively. The reaction time is usually 5 to 20 hours.

<Organic solvent>
The curable resin composition of the present invention contains an organic solvent. By using an organic solvent, the urethane (meth) acrylate oligomer is dissolved well, and the viscosity for forming a coating film when the urethane (meth) acrylate oligomer is cured by irradiation with active energy rays as described later. And a uniform cured film can be obtained.

  Any known organic solvent can be used as the organic solvent as long as the effects of the present invention are obtained. The organic solvent preferably has a solubility parameter (hereinafter referred to as “SP value”) of 8.0 to 11.5. An SP value of 8.0 or more is preferable from the viewpoint of the solubility of the urethane (meth) acrylate oligomer, and a SP value of 11.5 or less is preferable from the viewpoint of the transparency of the solution. Examples of the organic solvent in the above range include toluene (SP value: 9.1), xylene (SP value: 9.1), ethyl acetate (SP value: 8.7), butyl acetate (SP value: 8.7). ), Cyclohexanone (SP value: 9.8), methyl ethyl ketone (SP value: 9.0), methyl isobutyl ketone (SP value: 8.7), N-methylpyrrolidone (SP value: 11.2), and the like. It is done. In the present invention, the SP value represents a solubility parameter, and the value is calculated by the method proposed by Fedors et al. Specifically, it is a value obtained by referring to “POLYMER ENGINEERING AND SCIENCE, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (Pp. 147 to 154)”. The SP value is a physical property value determined by the content of the hydrophobic group or hydrophilic group of the molecule, and means a value as a mixture when a mixed solvent is used.

  The organic solvent can usually be used in an amount of 10 to 900 parts by weight with respect to 100 parts by weight of the solid content of the curable resin composition. “Solid content” as used herein means not only urethane acrylate (meth) acrylate oligomers but also all components excluding solvents, not only in solid state but also in semi-solid or viscous liquid form Is also included.

<Other ingredients>
The curable resin composition of the present invention is a component other than the urethane (meth) acrylate oligomer and the organic solvent (referred to as “other components” in the present invention) as long as the effects of the present invention are not significantly impaired. May be included). Examples of other components include an active energy ray reactive monomer, an active energy ray curable oligomer (excluding the urethane (meth) acrylate oligomer used in the present invention), a polymerization initiator, a photosensitizer, an epoxy compound, and others. And the like.

  In the curable resin composition of the present invention, the content of the urethane (meth) acrylate oligomer is 40% by weight based on the total amount of all components excluding the solvent in the curable resin composition such as the active energy ray reactive component. It is preferable that the amount be 60% by weight or more. In addition, the upper limit of this content is 100 weight%. When the content of the urethane (meth) acrylate oligomer is 40% by weight or more, the curability is good and the three-dimensional workability tends to be improved without excessively increasing the mechanical strength when the cured film is formed. Therefore, it is preferable.

  Further, in the curable resin composition of the present invention, the content of the total amount of the active energy ray-reactive component including the urethane (meth) acrylate oligomer is excellent in the curing rate and surface curability as the composition, and the tack remains. From the standpoint of absence, it is preferably 60% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and 95% by weight or more based on the total amount of the composition. Even more preferably. In addition, the upper limit of this content is 100 weight%.

Any known active energy ray-reactive monomer can be used as the active energy ray-reactive monomer as long as the effects of the present invention are obtained. These active energy ray-reactive monomers are used for the purpose of adjusting the hydrophilicity / hydrophobicity of the urethane (meth) acrylate oligomer and the physical properties such as hardness and elongation of the cured film when the resulting composition is a cured film. The An active energy ray reactive monomer may be used individually by 1 type, and 2 or more types may be mixed and used for it.

Examples of such active energy ray reactive monomers include vinyl ethers, (meth) acrylamides, and (meth) acrylates. Specific examples include styrene, α-methylstyrene, α-chlorostyrene. Aromatic vinyl monomers such as vinyltoluene and divinylbenzene; vinyl such as vinyl acetate, vinyl butyrate, N-vinylformamide, N-vinylacetamide, N-vinyl-2-pyrrolidone, N-vinylcaprolactam and divinyl adipate Ester monomers; Vinyl ethers such as ethyl vinyl ether and phenyl vinyl ether; Allyl compounds such as diallyl phthalate, trimethylolpropane diallyl ether, and allyl glycidyl ether; (meth) acrylamide, N, N-dimethylacrylamide N, N-dimethylmethacrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, Nt-butyl (meth) acrylamide, (meth) acryloylmorpholine (Meth) acrylamides such as methylenebis (meth) acrylamide; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylate-n-butyl , (Meth) acrylic acid-i-butyl, (meth) acrylic acid-t-butyl, (meth) acrylic acid hexyl, (meth) acrylic acid-2-ethylhexyl, (meth) acrylic acid lauryl, (meth) acrylic acid Stearyl, tetrahydrofurfuryl (meth) acrylate, (meth) a Morpholyl laurate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, dimethyl (meth) acrylate Aminoethyl, diethylaminoethyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl (meth) acrylate , (Meth) acrylic acid dicyclopentenyloxyethyl, (meth) acrylic acid dicyclopentanyl, (meth) acrylic acid allyl, (meth) acrylic acid-2-ethoxyethyl, (meth) acrylic acid isobornyl, (meth) Monofunctional (meth) acrylic acid such as phenyl acrylate And ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate ( n = 5-14), propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, di (meth) Polypropylene glycol acrylate (n = 5-14), di (meth) acrylic acid-1,3-butylene glycol, di (meth) acrylic acid-1,4-butanediol, di (meth) acrylic acid polybutylene glycol ( n = 3-16), di (meth) acrylic acid poly Li (1-methylbutylene glycol) (n = 5-20), di (meth) acrylic acid-1,6-hexanediol, di (meth) acrylic acid-1,9-nonanediol, di (meth) acrylic acid Neopentyl glycol, hydroxypivalate neopentyl glycol di (meth) acrylate, di (meth) acrylate dicyclopentanediol, di (meth) acrylate tricyclodecane, trimethylolpropane tri (meth) acrylate, pentaerythritol Tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hex (Meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, trimethylolpropane trioxypropyl (meth) acrylate, trimethylolpropane polyoxyethyl (meth) acrylate, trimethylolpropane polyoxypropyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) acrylate , Propylene oxide-added bisphenol A di (meth) acrylate, propylene oxide-added bisphenol F di (meth) acrylate, tri Black decanedimethanol di (meth) acrylate, bisphenol A epoxy di (meth) acrylate, polyfunctional (meth) acrylates such as bisphenol F epoxy di (meth) acrylate; and the like.

  Among these, in particular, in applications where coating properties are required for the composition of the present invention, (meth) acryloylmorpholine, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate , Molecules such as trimethylcyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, (meth) acrylamide, etc. A monofunctional (meth) acrylate having a ring structure in the inside is preferred. On the other hand, in applications where mechanical strength of the resulting cured film is required, di (meth) acrylic acid-1,4-butanediol, di (meth) ) Acrylic acid-1,6-hexanediol, di (meth) acrylic acid-1,9-nonane Dipentaglycol di (meth) acrylate, tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipenta Polyfunctional (meth) acrylates such as erythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate are preferred, and di (( Poly (ethylene glycol) acrylate (n = 5-14), polypropylene glycol di (meth) acrylate (n = 5-14), poly (butylene glycol di (meth) acrylate (n = 3-16), di (meth) )acrylic Poly (1-methyl-butylene glycol) (n = 5 to 20) Polyether (meth) acrylates are preferable.

  In the curable resin composition of the present invention, the content of the active energy ray-reactive monomer is the total amount of the composition from the viewpoint of adjusting the viscosity of the composition and adjusting physical properties such as hardness and elongation of the cured film obtained. On the other hand, it is preferably 50% by weight or less, more preferably 30% by weight or less, further preferably 20% by weight or less, and still more preferably 10% by weight or less.

  The active energy ray-curable oligomer may be used alone or in combination of two or more. Examples of the active energy ray-curable oligomer include epoxy (meth) acrylate oligomers and acrylic (meth) acrylate oligomers. In the curable resin composition of the present invention, the content of the active energy ray-reactive oligomer is 50% by weight with respect to the total amount of the composition from the viewpoint of adjusting physical properties such as hardness and elongation of the obtained cured film. It is preferably at most 30% by weight, more preferably at most 20% by weight, particularly preferably at most 10% by weight.

  The polymerization initiator is mainly used for the purpose of improving the initiation efficiency of a polymerization reaction that proceeds by irradiation with active energy rays such as ultraviolet rays and electron beams. As the polymerization initiator, a photoradical polymerization initiator which is a compound having a property of generating radicals by light is generally used, and any known photoradical polymerization initiator can be used as long as the effects of the present invention can be obtained. It is. A polymerization initiator may be used individually by 1 type, and 2 or more types may be mixed and used for it. Furthermore, you may use together radical photopolymerization initiator and a photosensitizer.

Examples of the photo radical polymerization initiator include benzophenone, 2,4,6-trimethylbenzophenone, 4,4-bis (diethylamino) benzophenone, 4-phenylbenzophenone, methylorthobenzoylbenzoate, thioxanthone, diethylthioxanthone, isopropylthioxanthone, chloro Thioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoin methyl ether, benzoin ethyl Ether, benzoin isopropyl ether, benzoin isobutyl ether, methylbenzoylformate, 2-methyl-1- [4- ( Tilthio) phenyl] -2-morpholinopropan-1-one, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4 4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, and 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl]- Phenyl] -2-methyl-propan-1-one and the like.

  Among these, benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,4,6, since the curing speed is high and the crosslinking density can be sufficiently increased. -Trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl] -2-methyl-propan-1-one 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl ] 2-Methyl-propan-1-one is more preferred.

  In addition, when the curable resin composition contains a compound having a cationically polymerizable group such as an epoxy group together with a radically polymerizable group, a photocationic polymerization initiator is used as a polymerization initiator together with the above-mentioned photoradical polymerization initiator. It may be included. Any known cationic photopolymerization initiator may be used as long as it does not significantly impair the effects of the present invention.

  The content of these polymerization initiators in the curable resin composition of the present invention is preferably 10 parts by weight or less with respect to a total of 100 parts by weight of the active energy ray reactive components, and is preferably 5 parts by weight or less. It is more preferable that It is preferable for the content of the photopolymerization initiator to be equal to or lower than the above upper limit value because the mechanical strength is not easily lowered by the initiator decomposition product.

  The photosensitizer can be used for the same purpose as the polymerization initiator. A photosensitizer may be used individually by 1 type and may be used in mixture of 2 or more types. As the photosensitizer, any known photosensitizer can be used as long as the effects of the present invention are obtained. Examples of such photosensitizers include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, amyl 4-dimethylaminobenzoate, And 4-dimethylaminoacetophenone.

  In the curable resin composition of the present invention, the content of the photosensitizer is preferably 10 parts by weight or less with respect to a total of 100 parts by weight of the active energy ray reactive components. The following is more preferable. It is preferable for the content of the photosensitizer to be not more than the above upper limit value because it is difficult for the mechanical strength to decrease due to a decrease in the crosslinking density.

The additive is optional as long as the effects of the present invention are obtained, and various materials added to a composition used for the same application can be used as the additive. An additive may be used individually by 1 type, and 2 or more types may be mixed and used for it. Examples of such additives include glass fiber, glass bead, silica, alumina, calcium carbonate, mica, zinc oxide, titanium oxide, mica, talc, kaolin, metal oxide, metal fiber, iron, lead, and metal powder. Fillers such as carbon fibers, carbon black, graphite, carbon nanotubes, carbon materials such as fullerenes such as C60 (fillers and carbon materials may be collectively referred to as “inorganic components”); Agent, heat stabilizer, ultraviolet absorber, hindered amine light stabilizer (HALS), anti-fingerprint agent, surface hydrophilizing agent, antistatic agent, slipperiness imparting agent, plasticizer, mold release agent, antifoaming agent, leveling agent, Anti-settling agents, surfactants, thixotropy imparting agents, lubricants, flame retardants, flame retardant aids, polymerization inhibitors, fillers, silane coupling agents and other modifiers; pigments, dyes, hue adjustments Colorants and the like; and, monomer and / or oligomer thereof, or a curing agent required for the synthesis of inorganic components, catalysts, curing accelerators like; and the like.

  In the curable resin composition of the present invention, the content of the additive is preferably 10 parts by weight or less with respect to a total of 100 parts by weight of the active energy ray reactive components, and is 5 parts by weight or less. More preferably. It is preferable for the content of the additive to be equal to or less than the above upper limit value because it is difficult for the mechanical strength to decrease due to a decrease in the crosslinking density.

  There are no particular limitations on the method for incorporating the optional components such as the above-mentioned additives into the curable resin composition of the present invention, and conventionally known mixing and dispersing methods may be mentioned. In addition, in order to disperse | distribute the said arbitrary component more reliably, it is preferable to perform a dispersion | distribution process using a disperser. Specifically, for example, two rolls, three rolls, bead mill, ball mill, sand mill, pebble mill, tron mill, sand grinder, seg barrier striker, planetary stirrer, high speed impeller disperser, high speed stone mill, high speed impact mill , A kneader, a homogenizer, an ultrasonic disperser and the like.

<Physical properties of curable resin composition>
The curable resin composition of the present invention preferably has a molecular weight between calculated network crosslinking points of 1,000 to 15,000. In the present invention, the “molecular weight between calculated network cross-linking points” is an average value of molecular weights between active energy ray reactive groups (hereinafter sometimes referred to as “cross-linking points”) that form a network structure in the entire composition. Means. The molecular weight between the calculated network crosslinking points correlates with the network area at the time of forming the network structure, and the larger the calculated molecular weight between the crosslinking points, the lower the crosslinking density. In the reaction of curing the curable resin composition with active energy rays, when a compound having only one active energy ray reactive group (hereinafter sometimes referred to as “monofunctional compound”) is reacted, On the other hand, when a compound having two or more active energy ray reactive groups (hereinafter sometimes referred to as “polyfunctional compound”) reacts, a network structure is formed.

  Therefore, the active energy ray reactive group possessed by the polyfunctional compound is the crosslinking point, and the calculation of the molecular weight between the calculated network crosslinking points is centered on the polyfunctional compound having the crosslinking point, and the monofunctional compound is the crosslinking possessed by the polyfunctional compound. The molecular weight between points of calculation network cross-linking points is calculated as the effect of extending the molecular weight between points, and the calculation of the molecular weight between cross-linking points of calculation network is the same reactivity of all active energy ray reactive groups. It is calculated on the assumption that all active energy ray reactive groups react by irradiation with active energy rays.

  In a polyfunctional compound single system in which only one kind of polyfunctional compound reacts, the molecular weight between calculated network crosslinking points is twice the average molecular weight per active energy ray reactive group of the polyfunctional compound. For example, (1000/2) × 2 = 1000 for a bifunctional compound with a molecular weight of 1,000, and (300/3) × 2 = 200 for a trifunctional compound with a molecular weight of 300.

On the other hand, in the mixed system of polyfunctional compounds in which multiple types of polyfunctional compounds react, the average value of the molecular weights between the calculated network cross-linking points of each of the above single systems with respect to the total number of active energy ray reactive groups contained in the composition Is the molecular weight between the calculated network cross-linking points of the composition. For example, in a composition comprising a mixture of 4 moles of a bifunctional compound having a molecular weight of 1,000 and 4 moles of a trifunctional compound having a molecular weight of 300, the total number of reactive energy ray reactive groups in the composition is 2 × 4 + 3 × 4 = 20. The molecular weight between the calculated network cross-linking points of the composition is {(1000/2) × 8 + (300/3) × 12} × (2/20) = 520.

  When the curable resin composition contains a monofunctional compound, it is calculated to form an active energy ray reactive group (that is, a crosslinking point) of the polyfunctional compound in an equimolar amount and the monofunctional compound linked to the crosslinking point. Assuming that the reaction is carried out so as to be located in the middle of the formed molecular chain, the extension of the molecular chain by the monofunctional compound at one crosslinking point is the total molecular weight of the monofunctional compound, and the total activity of the polyfunctional compound in the composition It is half of the value divided by the number of energy ray reaction radix. Here, since the molecular weight between the calculated network cross-linking points is considered to be twice the average molecular weight per cross-linking point, the amount extended by the monofunctional compound relative to the calculated molecular weight between the cross-linking points calculated for the polyfunctional compound is The value obtained by dividing the total molecular weight of the monofunctional compound by the total number of reactive energy ray reactive groups of the polyfunctional compound in the composition.

  For example, in a composition comprising a mixture of 40 mol of a monofunctional compound having a molecular weight of 100 and 4 mol of a bifunctional compound having a molecular weight of 1,000, the number of reactive energy ray reactive groups of the polyfunctional compound is 2 × 4 = 8. The extension due to the monofunctional compound in the molecular weight between the calculated network cross-linking points is 100 × 40/8 = 500. That is, the molecular weight between calculated network crosslinks of the composition is 1000 + 500 = 1500.

From the above, in the mixture of monofunctional compounds M _A molar molecular weight W _A, and f _B functional compound M _B mol molecular weight W _B, and f _C functional compound M _C mol molecular weight W _C, the composition The molecular weight between the calculated network cross-linking points of the product can be expressed by the following formula.

  The molecular weight between the calculated network crosslinking points of the curable resin composition of the present invention thus calculated is preferably 1,000 or more, more preferably 2,000 or more, and 3,000 or more. More preferably, it is particularly preferably 4,000 or more, on the other hand, preferably 15,000 or less, more preferably 12,000 or less, and particularly preferably 10,000 or less. .

  When the molecular weight between the calculated network crosslinking points is not more than the above upper limit value, the stain resistance of the cured film obtained from the curable resin composition tends to be good. Further, when the molecular weight between the calculated network cross-linking points is not less than the above lower limit value, the three-dimensional workability of the obtained cured film tends to be good. This is because the three-dimensional workability and stain resistance depend on the distance between the cross-linking points in the network structure. When this distance is increased, the structure becomes flexible and easily stretched, and the three-dimensional processability is excellent. It is presumed that this is because the structure becomes a strong structure and is excellent in stain resistance.

The molecular weight between the calculation network cross-linking points can be controlled, for example, by adding a monomer for forming a molecular weight of the urethane (meth) acrylate oligomer or a cross-linked structure. For example, when the number average molecular weight of the urethane (meth) acrylate oligomer is lowered or the polyfunctional acrylate is added, the value of the molecular weight between calculated network crosslinking points tends to be lowered.

  The viscosity of the curable resin composition of the present invention can be appropriately adjusted according to the use and usage of the curable composition, but from the viewpoints of handleability, coatability, moldability, three-dimensional formability, etc. The viscosity at 25 ° C. in a type viscometer (rotor 1 ° 34 ′ × R24) is preferably 10 mPa · s or more, more preferably 30 mPa · s or more, while 50,000 mPa · s or less. It is preferably 10,000 mPa · s or less, more preferably 5,000 mPa · s or less, and particularly preferably 2,000 mPa · s or less. The viscosity of the curable resin composition can be adjusted by, for example, the content of the urethane (meth) acrylate oligomer according to the present invention, the type of the optional component, the blending ratio thereof, and the like.

  Examples of the coating method of the curable resin composition of the present invention include a bar coater method, an applicator method, a curtain flow coater method, a roll coater method, a spray method, a gravure coater method, a comma coater method, a reverse roll coater method, and a lip coater method. Known methods such as a die coater method, a slot die coater method, an air knife coater method, and a dip coater method can be applied, and among them, a bar coater method and a gravure coater method are preferable.

  The curable resin composition of the present invention is preferably a tensile film having a tensile modulus measured by the following method of 1,000 to 4,000 MPa with respect to a cured film formed by the following method. . When this tensile elastic modulus is 1,000 to 4,000 MPa or less, excellent hardness can be obtained. A tensile modulus of 1,000 MPa or more is preferable from the viewpoints of scratch resistance, contamination resistance, wear resistance, and the like. On the other hand, if it is 4,000 MPa or less, it is preferable from the viewpoint of three-dimensional workability. This tensile elastic modulus is more preferably from 1300 to 3,000 MPa, and even more preferably from 1,500 to 2,500 MPa, from the viewpoint of making the above effects better. In addition, the film forming method and measuring method at the time of measuring this tensile elastic modulus are as follows.

(Film forming method)
A curable resin composition is coated on a polyethylene terephthalate film with a bar coater to form a coating film, and then dried at 60 ° C. for 1 minute, and accelerated using an electron beam irradiation device (CB175, manufactured by Eyegraphic). After irradiating the dried coating film with an electron beam under the conditions of a voltage of 165 kV and an irradiation dose of 5 Mrad, and further curing at 23 ° C. for 1 day to form a cured film, the cured film is peeled off from the polyethylene terephthalate film to have a film thickness of about 20 μm. A cured film is obtained.

(Tensile modulus measurement method)
The cured film is cut to a width of 10 mm, and a Tensilon tensile tester ("RTC-1210A" manufactured by Orientec Co., Ltd.) is used. The tensile modulus is measured by performing a tensile test under the conditions. More specifically, a straight line connecting the stress at 0% elongation and the stress at 0.5% elongation of the stress-strain curve (SS curve) obtained by conducting the tensile test under the above conditions is extended to 100 The stress converted at% elongation is taken as the tensile modulus.

  The curable resin composition of the present invention can be cured by an active energy ray as described later to obtain a cured product. The shape is not particularly limited, but is preferably a cured film shape as described below.

[Curing film]
The cured film of the present invention can be obtained by irradiating the curable resin composition with active energy rays. Examples of the active energy ray used for curing the curable resin composition include infrared rays, visible rays, ultraviolet rays, X rays, electron rays, α rays, β rays, γ rays and the like. It is preferable to use an electron beam or an ultraviolet ray from the viewpoint of apparatus cost and productivity. As a light source, an electron beam irradiation apparatus, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, Ar A laser, a He—Cd laser, a solid laser, a xenon lamp, a high frequency induction mercury lamp, sunlight, or the like is suitable.

The irradiation amount of the active energy ray can be appropriately selected according to the type of the active energy ray. For example, when it hardens | cures by electron beam irradiation, it is preferable that the irradiation amount is 1-15 Mrad. Moreover, when hardening by ultraviolet irradiation, it is preferable that it is 50-1,500 mJ / cm < ² >.

  When curing, any atmosphere of air, inert gas such as nitrogen or argon may be used. Moreover, you may irradiate in the sealed space between a film or glass, and a metal metal mold | die.

  The film thickness of the cured film of the present invention is appropriately determined according to the intended use, but the lower limit is preferably 1 μm, more preferably 3 μm. The upper limit is preferably 100 μm, more preferably 50 μm, and particularly preferably 20 μm. If the film thickness is equal to or greater than the above lower limit value, the appearance of design and functionality after three-dimensional processing tends to be favorable. Tends to be good.

[Laminate]
By forming the cured film of the present invention on a substrate, a laminate can be obtained (hereinafter, sometimes referred to as “the laminate of the present invention”). The laminate of the present invention is not particularly limited as long as it has a layer comprising the cured film of the present invention, and a layer other than the substrate and the cured film of the present invention is interposed between the substrate and the cured film of the present invention. You may have, and you may have on the outer side. Moreover, the said laminated body may have multiple layers of the base material and the cured film of this invention.

  As a method of obtaining a laminate having a multi-layer cured film, all layers are laminated in an uncured state and then cured with active energy rays, and the lower layer is cured with active energy rays or semi-cured. Apply a known method such as applying the upper layer and curing again with active energy rays, or applying each layer to the release film or base film and then laminating the layers in an uncured or semi-cured state. Although possible, a method of curing with an active energy ray after laminating in an uncured state is preferable from the viewpoint of improving adhesion between layers. As a method of laminating in an uncured state, a known method such as sequential coating in which the upper layer is applied after the lower layer is applied or simultaneous multilayer coating in which two or more layers are simultaneously applied from multiple slits is applied. Yes, but not necessarily.

  Examples of the base material include various kinds of polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polypropylene and polyethylene, various plastics such as nylon, polycarbonate, and (meth) acrylic resin, and plates formed of glass or metal. The article of the shape of this is mentioned. Among these, polyethylene terephthalate is preferable.

  The cured film of this invention and the laminated body obtained by forming this on a base material can be used as a coating substitute film. For example, the present invention can be effectively applied to interior and exterior building materials and various members such as automobiles, home appliances, and information electronic materials. In particular, the cured film of the present invention is useful as a decorative film using this as a top coat layer.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited at all by the following example. In addition, the value of various manufacturing conditions and evaluation results in the following examples has a meaning as a preferable value of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-described upper limit or lower limit value. A range defined by a combination of values of the following examples or values of the examples may be used.

[Measurement methods of physical properties and characteristics]
In the following Examples and Comparative Examples, the physical properties and properties of the urethane (meth) acrylate oligomer and cured film are measured and evaluated as follows.

<Physical properties of urethane (meth) acrylate oligomer>
1-1) Number average molecular weight (Mv) of urethane (meth) acrylate oligomer
Using GPC (“HLC-8120GPC” manufactured by Tosoh Corporation), tetrahydrofuran (THF) as a solvent, polystyrene as a standard sample, TSKgel superH1000 + H2000 + H3000 as a column, a liquid feeding speed of 0.5 mL / min, and a column oven temperature of 40 ° C. The number average molecular weight (GPC measurement value) of the urethane (meth) acrylate oligomer was measured.

<Physical properties of cured film>
2-1) Evaluation of coating film appearance The coating film appearance of the cured film laminated on polyethylene terephthalate obtained by the film-forming method I described later was visually evaluated according to the following criteria.
A: Uniform film thickness, and no abnormalities such as foreign matter, wrinkles, wrinkles, and crushed skin are observed on the coating surface.
(Triangle | delta): When the angle of a laminated body is changed or light is applied and stare, abnormality, such as a foreign material, a wrinkle, wrinkles, and a yuzu skin, is seen on the coating-film surface.
X: Abnormalities such as foreign matter, wrinkles, armpits, and yuzu skin are observed on the coating film surface.

2-2) The scratch resistance evaluation described later film forming method cured film laminated on a polyethylene terephthalate obtained in I, the haze value measured before the scratch test was H _1. On the other hand, under an atmosphere of 23 ° C. and 55% RH, a weight of 500 gf (per area of 4 cm ² ) was placed on a dry cloth (for cotton-JIS L 0803 compliant dyeing fastness test), and the polyethylene terephthalate obtained by the above-mentioned film forming method I the cured film surface that is laminated on Gakushin abrasion tester (manufactured by Toyo Seiki) 200 rubbed back and forth, the haze values measured immediately after the H _2. The difference between these H ₂ and H ₁ : ΔH (ΔH = H ₂ −H ₁ ) was determined. In the above, the haze value was measured in accordance with JIS K7105 using a haze meter (“HAZE METER HM-65W” manufactured by Murakami Color Research Laboratory Co., Ltd.). Further, in the same manner, in the atmosphere of 23 ° C. and 55% RH, a weight of 200 gf (per area of 4 cm ² ) was placed on steel wool (steel wool # 0000 manufactured by Nippon Steel Wool Co., Ltd.), and the above-mentioned film forming method I The cured film surface laminated on the polyethylene terephthalate obtained in (1) was rubbed back and forth 15 times with a Gakushoku abrasion tester (manufactured by Toyo Seiki).

2-3) Evaluation of stain resistance Sunscreen cream (Nivea SUN Protect Face Essence Milk manufactured by Nivea Kao Co., Ltd.) 0.005 g / cm ² on a cured film laminated on polyethylene terephthalate obtained by the film-forming method I described later. And allowed to stand at 80 ° C. for 1 hour. Thereafter, the degree of contamination after wiping off the contaminants with absorbent cotton containing water was visually evaluated. The contact conditions and evaluation criteria for each contaminant are as follows.
○: The contaminants can be completely wiped off.
Δ: Some contaminants remain.
X: The residue of a contaminant is remarkable.

2-4) Evaluation of abrasion resistance With respect to the surface of the cured film laminated on the polyethylene terephthalate obtained by the film-forming method I described later, using a wear wheel (manufactured by Calibrase: CS-10), A Taber abrasion test was performed at a load of 500 g, and the number of revolutions until the half of the substrate was exposed was evaluated. The abrasion resistance was evaluated as good when the rotational speed was 1,000 or more.

2-5) Evaluation of mechanical strength A cured film of the film formation method II described later is cut into a width of 10 mm, and a temperature of 23 ° C. and a humidity of 55 are obtained using a Tensilon tensile tester (“RTC-1210A” manufactured by Orientec). Tensile modulus was measured by performing a tensile test under the conditions of% RH, a tensile speed of 50 mm / min, and a distance between chucks of 50 mm. More specifically, a straight line connecting the stress at 0% elongation and the stress at 0.5% elongation of the stress-strain curve (SS curve) obtained by conducting the tensile test under the above conditions is extended to 100 The stress converted at% elongation was taken as the tensile modulus. If it was 1,000-4,000 MPa, it was evaluated that mechanical strength was favorable.

2-6) Evaluation of suitability for three-dimensional processing A cured film of a film forming method II described later is cut into a width of 10 mm, and a temperature of 100 ° C. is used using a Tensilon tensile tester (“MX2-500N” manufactured by Imada Co., Ltd.). The breaking elongation was measured under the conditions of a tensile speed of 40 mm / min and a distance between chucks of 40 mm. If the elongation at break was 50% or more, it was evaluated that the three-dimensional formability was good.

[Raw materials / solvents]
The raw materials and solvents used in Examples and Comparative Examples below and their abbreviations are as follows. (Compound (A))
IPDI: Isophorone diisocyanate (trade name “VESTANAT IPDI” manufactured by Evonik Degussa Japan)
(Compound (B))
1,12-DD: 1,12 dodecanediol (trade name “1,12-dodecanediol” manufactured by Ube Industries, Ltd.)
(Diol component other than compound (B))
1,6-HD: 1,6-hexanediol 1,4-CHDM: 1,4-cyclohexanedimethanol (compound (C))
V-300: mixture of 40 to 45% by weight of pentaerythritol triacrylate and 35 to 40% by weight of pentaerythritol tetraacrylate (catalog value) (trade name Biscoat 300, manufactured by Osaka Organic Chemical Co., Ltd.)
(Organic solvent)
MEK: methyl ethyl ketone (SP value: 9.0)

[Example 1]
In a four-necked flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 136 g of IPDI, 104 g of 1,12-dodecanediol, 240 g of methyl ethyl ketone, and 0.02 g of dioctyltin dilaurate were added to oil. The reaction was conducted for 9 hours while heating to 80 ° C. in a bath. After cooling to 60 ° C. after completion of the reaction, 0.1 g of dioctyltin dilaurate, 0.2 g of methyl hydroquinone and 109 g of methyl ethyl ketone were further added, and 109 g of V-300 was added dropwise to initiate the reaction. The reaction was carried out for 10 hours while heating to 70 ° C. in an oil bath, and after confirming the end point of the reaction by disappearance of the peak derived from the isocyanate (NCO) group in the infrared absorption spectrum, 300 g of methyl ethyl ketone was added, and curable resin was added. A composition was obtained. About the urethane acrylate oligomer in the obtained curable resin composition, the number average molecular weight was measured by the method of said 1-1). The obtained results are shown in Table-1.

(Film forming method I)
A curable resin composition is coated on a polyethylene terephthalate film with a bar coater to form a coating film, and then dried at 60 ° C. for 1 minute, and accelerated using an electron beam irradiation device (CB175, manufactured by Eyegraphic). Curing by irradiating the dried coating film with an electron beam under the conditions of a voltage of 165 kV and an irradiation dose of 5 Mrad, and further curing at 23 ° C. for one day to form a cured film, and a cured film having a thickness of about 5 μm is laminated on polyethylene terephthalate A membrane was obtained. About the obtained cured film, the physical-property evaluation of said 2-1) -2-4) was performed. These results are shown in Table-1.

(Film Formation Method II)
A curable resin composition is coated on a polyethylene terephthalate film with a bar coater to form a coating film, and then dried at 60 ° C. for 1 minute, and accelerated using an electron beam irradiation device (CB175, manufactured by Eyegraphic). After irradiating the dried coating film with an electron beam under the conditions of a voltage of 165 kV and an irradiation dose of 5 Mrad, and further curing at 23 ° C. for 1 day to form a cured film, the cured film is peeled off from the polyethylene terephthalate film to have a film thickness of about 20 μm. A cured film was obtained. About the obtained cured film, the physical-property evaluation of said 2-5) and 2-6) was performed. These results are shown in Table-1.

[Comparative Example 1]
Into a four-necked flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 165 g of IPDI and 76 g of 1,6-hexanediol were added, and 241 g of methyl ethyl ketone and 0.02 g of dioctyltin dilaurate were added and The reaction was conducted for 9 hours while heating to 80 ° C. in a bath. After completion of the reaction, the reaction mixture was cooled to 60 ° C., 0.1 g of dioctyltin dilaurate, 0.2 g of methyl hydroquinone and 108 g of methyl ethyl ketone were further added, and 108 g of V-300 was added dropwise to initiate the reaction. The reaction was carried out for 10 hours while heating to 70 ° C. in an oil bath, and after confirming the end point of the reaction by disappearance of the peak derived from the isocyanate (NCO) group in the infrared absorption spectrum, 300 g of methyl ethyl ketone was added, and curable resin was added. A composition was obtained.

  About the urethane acrylate oligomer in the obtained curable resin composition, it carried out similarly to Example 1, and measured the number average molecular weight by the method of said 1-1). Moreover, the curable resin composition was formed into a film in the same manner as in Example 1, and the physical properties of the above 2-1) to 2-6) were evaluated. These results are shown in Table-1.

[Comparative Example 2]
In a four-necked flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 155 g of IPDI and 86 g of 1,4-cyclohexanedimethanol were added, and 241 g of methyl ethyl ketone and 0.02 g of dioctyltin dilaurate were added. The reaction was conducted for 9 hours while heating to 80 ° C. in an oil bath. After cooling to 60 ° C. after completion of the reaction, 0.1 g of dioctyltin dilaurate, 0.2 g of methyl hydroquinone and 109 g of methyl ethyl ketone were further added, and 109 g of V-300 was added dropwise to initiate the reaction. The reaction was carried out for 10 hours while heating to 70 ° C. in an oil bath, and after confirming the end point of the reaction by disappearance of the peak derived from the isocyanate (NCO) group in the infrared absorption spectrum, 300 g of methyl ethyl ketone was added, and curable resin was added. A composition was obtained.

  About the urethane acrylate oligomer in the obtained curable resin composition, it carried out similarly to Example 1, and measured the number average molecular weight by the method of said 1-1). Moreover, the curable resin composition was formed into a film in the same manner as in Example 1, and the physical properties of the above 2-1) to 2-6) were evaluated. These results are shown in Table-1.

[Evaluation results]
As shown in Table 1, the cured film of Example 1 corresponding to the present invention has the same three-dimensional workability and mechanical strength as compared with Comparative Examples 1 and 2, but the appearance of the coating film and scratch resistance. It can be seen that it is excellent in all of resistance, contamination resistance, and abrasion resistance.

Claims (7)

A curable resin composition comprising a urethane (meth) acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C) and an organic solvent, wherein the compound (B) A curable resin composition comprising 40% by weight or more of a diol component.
Compound (A): Polyisocyanate compound having alicyclic structure (B): Chain aliphatic diol compound having 8 to 16 carbon atoms (C): Hydroxyalkyl (meth) acrylate   The curable resin composition of Claim 1 whose number average molecular weights (Mv) of the said urethane (meth) acrylate are 500-15,000.   The curable resin composition of Claim 1 or 2 containing a C8-C16 linear aliphatic diol as said compound (B).   The curable resin composition according to any one of claims 1 to 3, comprising hydroxyalkyl poly (meth) acrylate as the compound (C).   The curable resin composition according to any one of claims 1 to 4, wherein a solubility parameter of the organic solvent is 8.0 to 11.5.   The urethane (meth) acrylate oligomer is obtained by reacting the compound (A) and the compound (B) to obtain a urethane prepolymer, and then reacting the compound (C) with the urethane prepolymer. Item 6. The curable resin composition according to any one of Items 1 to 5.   The cured film obtained by irradiating an active energy ray to the curable resin composition of any one of Claims 1 thru | or 6.