JP2014231591A - Urethane (meth)acrylate oligomer, curable resin composition, cured product and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an urethane (meth)acrylate oligomer capable of giving a cured product excellent in alkali resistance and processing characteristics, a curable resin composition, a cured product and a laminate.SOLUTION: A urethane (meth)acrylate oligomer is obtained by reaction of at least the following compound (A), compound (B) and compound (C): compound (A): polyisocyanate; compound (B): a polycarbonate diol having a structural unit derived from an alkylene glycol with a carbon number of 7 to 14; and compound (C): hydroxyalkyl (meth)acrylate.

Description

  The 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, a cured film obtained by precuring a resin composition containing a urethane acrylate oligomer with an active energy ray was manufactured and subjected to a surface processing treatment or the like. Later, 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 the 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

  In addition to the characteristics that are improved in Patent Document 1, the alkali resistance of the cured product (cured film) and the processing suitability of the cured product (cured film) after curing are also important characteristics. That is, the subject of this invention is providing the urethane (meth) acrylate oligomer, curable resin composition, hardened | cured material, and laminated body which can give the hardened | cured material excellent in alkali resistance and the processing characteristic after hardening. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventors cured the curable resin composition containing the urethane (meth) acrylate oligomer obtained using a specific raw material, The present inventors have found that the problem can be solved and have reached the present invention. That is, the present invention is as follows.

[1] A urethane (meth) acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C).
Compound (A): Polyisocyanate compound (B): Polycarbonate diol compound (C) having a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms: Hydroxyalkyl (meth) acrylate

[2] The urethane (meth) acrylate oligomer according to [1], wherein the number average molecular weight (Mn) is 1,000 to 10,000.

[3] The urethane (meth) acrylate oligomer according to [1] or [2], wherein the compound (B) has a number average molecular weight (Mn (OHV)) of 500 to 5,000.

[4] The urethane (meth) acrylate oligomer according to any one of [1] to [3], wherein the compound (B) further has a structural unit derived from an alkylene glycol having 2 to 6 carbon atoms.

[5] In the compound (B), a ratio of a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms and a structural unit derived from an alkylene glycol having 2 to 6 carbon atoms is 1:99 to 99: The urethane (meth) acrylate oligomer according to [4], which is 1.

[6] The urethane (meth) acrylate oligomer according to any one of [1] to [5], wherein the alkylene glycol having 7 to 14 carbon atoms is 1,10-decanediol.

[7] The urethane (meth) acrylate oligomer according to any one of [4] to [6], wherein the alkylene glycol having 2 to 6 carbon atoms is 1,4-butanediol.

[8] The urethane (meth) acrylate oligomer according to any one of [1] to [7], wherein the compound (A) is a polyisocyanate having an alicyclic structure.

[9] The urethane (meth) acrylate oligomer according to any one of [1] to [8], wherein the compound (C) is a hydroxyalkyl poly (meth) acrylate.

[10] A compound obtained by reacting the compound (A) and the compound (B) to obtain a urethane prepolymer, and then reacting the compound with the compound (C). [1] to [9] The urethane (meth) acrylate oligomer according to any one of the above.

[11] A curable resin composition comprising the urethane (meth) acrylate oligomer according to any one of [1] to [10] and an organic solvent.

[12] A cured product obtained by irradiating the curable resin composition according to [11] with active energy rays.

[12] A laminate formed by forming the cured product according to [11] on a substrate.

[13] The laminate according to [12], wherein the base material is polyester.

  ADVANTAGE OF THE INVENTION According to this invention, the urethane (meth) acrylate oligomer, curable resin composition, hardened | cured material, and laminated body which can give the hardened | cured material excellent in alkali resistance and the workability after hardening are 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.

[Urethane (meth) acrylate oligomer]
The urethane (meth) acrylate oligomer of the present invention is obtained by reacting at least the following compound (A), compound (B) and compound (C).
Compound (A): Polyisocyanate compound (B): Polycarbonate diol compound (C) having a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms: Hydroxyalkyl (meth) acrylate

  According to the urethane (meth) acrylate oligomer of the present invention, a curable resin composition containing the oligomer and a cured film obtained by curing the composition are not only excellent in alkali resistance but also excellent in processing characteristics. The reason why the cured product obtained by using the urethane (meth) acrylate oligomer of the present invention has the excellent effects as described above is not clear, but is considered to be due to the following reason.

  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 of the present invention is a structural unit derived from a C7-14 alkylene glycol having a long chain length as the compound (B) used as a raw material, although there are drawbacks such as reduced water resistance and alkali resistance. By using a polycarbonate diol having, the distance between urethane bonds in the molecule is increased. This eliminates brittleness due to intermolecular hydrogen bonding, and it has excellent flexibility for processing after curing because it maintains hardness while having appropriate flexibility, and also has excellent water resistance and alkali resistance. This is thought to be due to the formation of a cured product.

[Compound (A)]
Polyisocyanate is used as the compound (A) which is a raw material compound for producing the urethane (meth) acrylate oligomer in the present invention. Polyisocyanate is a compound having two or more isocyanate groups and / or substituents containing isocyanate groups in one molecule (also referred to as “isocyanate groups” in the present invention). 1 type may be used for the polyisocyanate of a compound (A), and 2 or more types may be used for it. Moreover, in 1 type of polyisocyanate, isocyanate groups may be the same and may differ.

  As a substituent containing an isocyanate group, a C1-C5 alkyl group, an alkenyl group, or an alkoxyl group containing one or more isocyanate groups is mentioned, for example. The number of carbon atoms of the alkyl group or the like as a substituent containing an isocyanate group is more preferably 1 to 3.

  Examples of the polyisocyanate include chain aliphatic polyisocyanate, polyisocyanate having an alicyclic structure, and aromatic polyisocyanate.

  A chain aliphatic polyisocyanate is a compound having a chain aliphatic structure and two or more isocyanate groups bonded thereto. An aliphatic polyisocyanate is preferable from the viewpoint of enhancing the weather resistance of a cured product obtained by curing the curable resin composition and imparting flexibility. The aliphatic structure in the 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. It is done.

The polyisocyanate is preferably a polyisocyanate having an alicyclic structure from the viewpoint of mechanical strength and stain resistance of a cured product obtained by curing the curable resin composition of the present invention.

  The polyisocyanate having an alicyclic structure is a compound having an alicyclic structure and two or more isocyanate groups bonded thereto. The alicyclic structure in the polyisocyanate having an alicyclic structure is not particularly limited, but is preferably a cycloalkylene group having 3 to 6 carbon atoms. 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; tris (isocyanate isophorone) isocyanurate And triisocyanate having an alicyclic structure.

  The polyisocyanate having an alicyclic structure is also preferable from the viewpoint of improving the weather resistance of a cured product obtained by curing the curable resin composition. Examples of the polyisocyanate having such an alicyclic structure include bis (Isocyanate methyl) cyclohexane, cyclohexane diisocyanate, bis (isocyanatocyclohexyl) methane, isophorone diisocyanate and the like.

  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 product obtained by curing the curable resin composition, and examples of such aromatic polyisocyanate include tolylene diisocyanate and diphenylmethane 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 product 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 calculated from the chemical formula in the case of a polyisocyanate composed of a single monomer, and from the NCO% in the case of a polyisocyanate composed of two or more monomers as follows. It can be determined by the calculated value.

  About the polyisocyanate which has molecular weight distribution by GPC, the number average molecular weight can be calculated | required as follows by NCO%.

<Calculation of the number average molecular weight of polyisocyanate by NCO%>
Into an Erlenmeyer flask, 1 g of polyisocyanate and 20 mL of a 0.5 mol / L dibutylamine toluene solution are added, diluted with 100 mL of acetone, and reacted at 25 ° C. for 30 minutes. Thereafter, the solution is titrated with a 0.5 mol / liter hydrochloric acid aqueous solution. Moreover, titration is performed similarly except polyisocyanate was not put into the Erlenmeyer flask, and a blank is obtained. And NCO% and a number average molecular weight are computed by the following formula | equation.
NCO% = {(Y1-X1) × 0.5 × 42.02} / (1 × 1000) × 100
X1: Amount of hydrochloric acid aqueous solution required for titration of polyisocyanate-containing solution (mL)
Y1: Amount of aqueous hydrochloric acid required for titration of blank solution containing no polyisocyanate (mL)
(Number average molecular weight of polyisocyanate) = (42.02 / (NCO%)) × (number of NCO groups contained in one molecule of polyisocyanate)

[Compound (B)]
The compound (B) used in the present invention is a polycarbonate diol having a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms. The polycarbonate diol of the compound (B) is usually obtained by transesterification of a dihydroxy compound containing an alkylene glycol having at least 7 to 14 carbon atoms and a carbonic acid diester.

<Chemical structure of compound (B)>
The polycarbonate diol of the compound (B) has a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms. When the polycarbonate diol of the compound (B) has a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms, good alkali resistance when made into a urethane (meth) acrylate oligomer and processability after curing can be obtained. it can.

  Examples of the alkylene glycol having 7 to 14 carbon atoms include 1,7-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 6-methyl-2,8-octanediol, , 9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol. Among these, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,8-octanediol, and the balance between the alkali resistance when polyurethane is used and the processability of the cured product are excellent. 10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol are preferable, and 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12- Dodecanediol is more preferable, 1,9-nonanediol, 1,10-decanediol and 1,12-dodecanediol are more preferable, 1,10-decanediol and 1,12-dodecanediol are particularly preferable, and 1,10 -Decanediol is most preferred.

  In the polycarbonate diol of the compound (B), the ratio of the structural unit derived from alkylene glycol having 7 to 14 carbon atoms to the structural unit derived from all dihydroxy compounds is preferably 5 mol% or more, more preferably 10 mol%. It is above, More preferably, it is 20 mol% or more. Moreover, the upper limit is 100 mol%.

  The polycarbonate diol of the compound (B) preferably has a structural unit derived from an alkylene glycol having 2 to 6 carbon atoms in addition to a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms from the viewpoint of blocking resistance. At this time, the structural unit derived from the alkylene alkylene glycol having 7 to 14 carbon atoms and the structural unit derived from the alkylene glycol having 2 to 6 carbon atoms may be copolymerized polycarbonate diols. It may be a mixture of polycarbonate diols having different olefins, but is preferably copolymerized. Specific examples of the alkylene glycol having 2 to 6 carbon atoms that can be used for the polycarbonate diol of the compound (B) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,2-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 3-methyl-1,5- Examples include pentanediol and 1,6-hexanediol. Among these, 1,4-butanediol is preferable.

When the compound (B) has a structural unit derived from an alkylene glycol having 2 to 6 carbon atoms, a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms and a structure derived from an alkylene glycol having 2 to 6 carbon atoms The molar ratio of the unit is preferably 1:99 to 99: 1, and more preferably 10:90 to 50:50. Moreover, as a preferable thing of the polycarbonate diol which has a structural unit derived from a C7-C14 alkylene glycol and a structural unit derived from a C2-C6 alkylene glycol, a C8-C12 alkylene glycol is preferable. A polycarbonate diol having a structural unit derived from and a structural unit derived from an alkylene glycol having 4 to 6 carbon atoms, and most preferred is a structural unit derived from 1,10-decanediol; A polycarbonate diol having a structural unit derived from 4-butanediol can be exemplified.

  The polycarbonate diol of the compound (B) may be referred to as a dihydroxy compound other than alkylene glycol having 7 to 14 carbon atoms and alkylene glycol having 2 to 6 carbon atoms unless the effects of the present invention are impaired. May have a structural unit derived from. Specific examples of the other dihydroxy compounds include linear dihydroxy compounds (except for those corresponding to alkylene glycols having 1 to 14 carbon atoms), dihydroxy compounds having an ether structure, and branched chains. Examples include dihydroxy compounds and dihydroxy compounds having an alicyclic structure.

  When other than the above-mentioned alkylene glycol having 2 to 6 carbon atoms is used as the other dihydroxy compound, in order to effectively obtain the effects of the present invention, the structural unit derived from the entire dihydroxy compound is converted into another dihydroxy compound. The proportion of the derived structural unit is preferably 50 mol% or less, more preferably 30 mol% or less, still more preferably 20 mol% or less, and most preferably 10 mol% or less. . It is preferable that the proportion of the structural units derived from other dihydroxy compounds is not more than the above upper limit value from the viewpoint of improving the balance between alkali resistance and processability of the cured product.

In the compound (B), the ratio (molar ratio) of the structural unit derived from the diol compound used as a raw material can be determined by analyzing polycarbonate diol by ¹ H-NMR. Specific examples of this measuring method will be shown in the following examples.

  The polycarbonate diol of the compound (B) has a structural unit derived from a carbonate compound. The carbonate compound that can be used here is not particularly limited, and examples thereof include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate. Among these, diaryl carbonate is preferable from the viewpoint of reactivity.

<Method for Producing Compound (B)>
Although the manufacturing method in particular of the compound (B) used for this invention is not restrict | limited, For example, the diol compound and carbonate compound which are the above-mentioned raw material can be obtained by performing transesterification in presence of a catalyst.

  In the production of the polycarbonate diol of the compound (B), the amount of the carbonate compound used is not particularly limited, but the lower limit is preferably 0.35 mol, more preferably 0.8 mol in terms of a molar ratio based on a total of 1 mol of all dihydroxy compounds. The upper limit is preferably 1.00 mol, more preferably 0.98 mol, and still more preferably 0.97 mol. The use amount of the carbonate compound is preferably not less than the above lower limit value from the viewpoint of increasing the molecular weight to a predetermined molecular weight, and on the other hand, if it is not more than the above upper limit value, the polycarbonate diol has a terminal hydroxyl group. It is preferable from the viewpoint of controlling the molecular weight.

  Examples of compounds that can be used in the transesterification reaction in the production of compound (B) include compounds of Group 1 metals of the periodic table such as lithium, sodium, potassium, rubidium, and cesium; magnesium, calcium, strontium, barium, and the like Periodic table Group 2 metal compounds such as titanium and zirconium; Periodic table Group 5 metal compounds such as hafnium; Group 9 metal compounds such as cobalt; Zinc and the like Periodic table Group 12 metal compounds such as aluminum; Periodic table Group 13 metal compounds such as aluminum; Periodic table Group 14 metal compounds such as germanium, tin and lead; Periodic table Group 15 metals such as antimony and bismuth Compounds; lanthanide metal compounds such as lanthanum, cerium, europium, ytterbium and the like. Among these, from the viewpoint of increasing the transesterification reaction rate, compounds of Group 1 metal of the periodic table, compounds of Group 2 metal of the periodic table, compounds of Group 4 metal of the periodic table, compounds of Group 5 metal of the periodic table, Periodic table Group 9 metal compound, Periodic table Group 12 metal compound, Periodic table Group 13 metal compound, Periodic table Group 14 metal compound are preferred, Periodic table Group 1 metal compound, Periodic table A compound of Group 2 metal is more preferable, and a compound of Group 2 metal of the periodic table is more preferable. Among the compounds of Group 1 metals of the periodic table, lithium, potassium, and sodium compounds are preferable, lithium and sodium compounds are more preferable, and sodium compounds are more preferable. Among the compounds of Group 2 metals of the periodic table, magnesium, calcium and barium compounds are preferred, calcium and magnesium compounds are more preferred, and magnesium compounds are more preferred. These metal compounds are mainly used as hydroxides and salts. Examples of salts when used as a salt include halide salts such as chloride, bromide and iodide; carboxylates such as acetate, formate and benzoate; methanesulfonic acid, toluenesulfonic acid and trifluoro Examples thereof include sulfonates such as romethanesulfonic acid; phosphorus-containing salts such as phosphates, hydrogen phosphates, and dihydrogen phosphates; acetylacetonate salts. The catalyst metal can also be used as an alkoxide such as methoxide or ethoxide.

  Among these, preferably, acetate, nitrate, sulfate, carbonate, phosphate, hydroxide, halide, alkoxide of at least one metal selected from Group 2 metals of the periodic table is used, More preferred are group 2 metal acetates, carbonates, and hydroxides of the periodic table, more preferred are magnesium, calcium acetates, carbonates, and hydroxides, and particularly preferred are magnesium and calcium. Acetate is used, most preferably magnesium acetate.

  The reaction temperature of the transesterification reaction when producing the compound (B) is usually 70 to 190 ° C, preferably 100 to 180 ° C. Moreover, the pressure at this time is 0.013-102 kPa normally, Preferably it is 0.015-33 kPa.

  When the above-described catalysts are used, the catalyst usually remains in the obtained polycarbonate diol. In order to suppress the influence of the remaining catalyst, 0.8 to 5.0 mol, preferably 1.0 to 3.0 mol of a catalyst deactivator is usually used with respect to 1.0 mol of the catalyst used. It is preferable to deactivate the catalyst. After adding the catalyst deactivator, the catalyst can be efficiently deactivated by heat treatment as described later. Examples of the catalyst deactivator include inorganic phosphoric acid such as phosphoric acid and phosphorous acid; organic phosphoric acid esters such as dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, and triphenyl phosphite. A phosphorus compound is mentioned. These catalyst deactivators may be used alone or in combination of two or more.

  Inactivation of the transesterification catalyst by adding a catalyst deactivator can be performed at room temperature, but heat treatment is more efficient. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 150 ° C., more preferably 120 ° C., still more preferably 100 ° C., and the lower limit is preferably 50 ° C., more preferably 60 ° C., even more preferably. Is 70 ° C.

<Physical properties of compound (B)>
The number average molecular weight (Mn (OHV)) determined from the hydroxyl value of the polycarbonate diol used in the present invention is preferably 500 or more, more preferably 700 or more, still more preferably 800 or more, while preferably It is 5,000 or less, More preferably, it is 4,000 or less, More preferably, it is 3,000 or less. If the Mn of the polycarbonate diol is less than the lower limit, sufficient flexibility may not be obtained when urethane is used. On the other hand, if the upper limit is exceeded, the viscosity increases, and handling during polyurethane formation may be impaired.

The molecular weight distribution of the polycarbonate diol used in the present invention ([weight average molecular weight (Mw)] / [number average molecular weight (Mn)]) is not particularly limited, but the lower limit is preferably 1.5, more preferably 1 .8. The upper limit is preferably 3.5, more preferably 3.0. When the molecular weight distribution exceeds the above upper limit, the properties of the polyurethane produced using this polycarbonate diol tend to become hard at low temperatures and decrease in elongation, and an attempt is made to produce a polycarbonate diol having a molecular weight distribution less than the above lower limit. Then, an advanced purification operation such as removing the oligomer may be necessary.
The weight average molecular weight is a polystyrene-equivalent weight average molecular weight, and the number-average molecular weight is a polystyrene-equivalent number average molecular weight, and can be usually determined by measurement of gel permeation chromatography (sometimes abbreviated as GPC).

  The lower limit of the hydroxyl value of the polycarbonate diol used in the present invention is preferably 20 mg-KOH / g, more preferably 25 mg-KOH / g, still more preferably 30 mg-KOH / g, and particularly preferably 35 mg-KOH / g. The upper limit is preferably 450 mg-KOH / g, more preferably 230 mg-KOH / g, still more preferably 150 mg-KOH / g, and particularly preferably 120 mg-KOH / g. When the hydroxyl value is equal to or higher than the lower limit, the viscosity of the obtained polycarbonate diol becomes appropriate, which is preferable from the viewpoint of handling of the polycarbonate diol, and when it is equal to or lower than the upper limit, flexibility when a urethane (meth) acrylate oligomer is obtained. And from the viewpoint of low temperature characteristics.

The hydroxyl value (OH value) and the number average molecular weight (Mn (OHV)) in terms of hydroxyl value of the compound (B) can be determined as follows. That is, based on JIS K1557-1, the hydroxyl value of polycarbonate diol is measured by a method using an acetylating reagent, and Mn (OHV) can be calculated from the value by the following formula.
Mn (OHV) = 56.1 × 2 × 1000 / (hydroxyl value)

  In this invention, the compound (B) can mention the aspect used by 40 weight% or more with respect to all the diol components used as a raw material of a urethane (meth) acrylate oligomer. It is preferable to use the compound (B) at 40% by weight or more 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-linked structure due to the involvement of multiple (meth) acryloyl groups in the curing 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 100 or more, and more preferably 110 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).

  Among the above, preferred is an embodiment in which pentaerythritol tri (meth) acrylate is used as a preferable one and a mixture of pentaerythritol tetraacrylate is used as another component described later. In an embodiment using a mixture of pentaerythritol tri (meth) acrylate and pentaerythritol tetraacrylate, the weight ratio of pentaerythritol tri (meth) acrylate, which is compound (C), to pentaerythritol tetraacrylate is 20:80 to 80: It is preferably 20, and more preferably 30:70 to 70:30. As a commercial product of such a mixture, trade name Biscoat 300 (mixture of 40 to 45% by weight of pentaerythritol triacrylate and 35 to 40% by weight of pentaerythritol tetraacrylate (catalog value)) manufactured by Osaka Organic Chemical Co., Ltd. may be mentioned.

[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 chain aliphatic diols having 1 to 7 carbon atoms, diols having an alicyclic structure, polyalkylene glycols, and other high molecular weight polyols (hereinafter referred to as “other high molecular weights”). Polyol "), chain extenders and the like.

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 polycarbonate diol (excluding those corresponding to the compound (B)) 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 Amine, 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 urethane (meth) acrylate oligomer of the present invention preferably has a number average molecular weight (Mn) of 1,000 or more, and more preferably 1,500 or more. On the other hand, it is preferably 10,000 or less, more preferably 5,000 or less, and still more preferably 3,000 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 product (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 alkali resistance of the cured product (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 alkali 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. On the other hand, when this distance is shortened, the network structure is strong. It is estimated that this is because of excellent scratch resistance, alkali 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 of the present invention can be obtained by reacting at least the compound (A), 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 combined under conditions such that the isocyanate group becomes excessive (conditions where there are more than 1 molar equivalent of the compound (A) relative to 1 molar equivalent of the total diol used as a raw material). ) To obtain a urethane prepolymer having an isocyanate terminal, and then reacting the urethane prepolymer having an isocyanate terminal with 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 (meth) acryloyl groups can be introduced at both ends, and as a result, a cured product can be easily obtained.

  The amount of all isocyanate groups in the urethane (meth) acrylate oligomer of the present invention and the amount of all functional groups that react with isocyanate groups such as hydroxyl groups and amino groups are usually equimolar in theory. 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 the urethane (meth) acrylate oligomer of the present invention, the amount of the compound (C) used is based on the total amount of the compound containing functional groups that react with isocyanate in the compound (C) and other raw materials. 3 mol% or more 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 of the present invention, 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 addition, it is good also as a curable resin composition mentioned later by leaving the organic solvent used in this way as it is.

  In the production of the urethane (meth) acrylate oligomer of the present invention, the total content of the urethane (meth) acrylate oligomer to be produced and its raw material compound is preferably 20% by weight or more based on the total amount of the reaction system, and is 40% by weight. % Or more is more preferable. 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.

  In the production of the urethane (meth) acrylate oligomer of the present invention, a catalyst can be used. 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 containing a (meth) acryloyl group like a compound (C) at the time of manufacture of the urethane (meth) acrylate oligomer of this invention, 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 of the present invention, 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.

[Curable resin composition]
The curable resin composition of the present invention includes the urethane (meth) acrylate oligomer of the present invention and an organic solvent.

<Organic solvent>
In the curable resin composition of the present invention, the organic solvent dissolves the urethane (meth) acrylate oligomer satisfactorily and is applied when the urethane (meth) acrylate oligomer is cured by irradiation with active energy rays as described later. It contributes to adjusting the viscosity for forming a film and obtaining a uniform cured product (cured film).

  In the curable resin composition of the present invention, 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 of the present invention), a polymerization initiator, a photosensitizer, an epoxy compound, and other components. An additive etc. are mentioned.

  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 components including the urethane (meth) acrylate oligomer is excellent in the curing speed and surface curability as the composition, and the tack is reduced. From the standpoint of not remaining, 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 with respect to the total amount of the composition. The above is even more preferable. 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 Tetra (meth) acrylate, ditrimethylolpropane tetra (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, tricyclodecane dimethanol di (meth) acrylate, bisphenol A And polyfunctional (meth) acrylates such as epoxy di (meth) acrylate and bisphenol F epoxy di (meth) acrylate.

  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, methyl orthobenzoylbenzoate, 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.

  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 crosslinking points” means the molecular weight between active energy ray reactive groups (hereinafter sometimes referred to as “crosslinking points”) that form a network structure in the curable resin composition. Mean value. 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. .

  It exists in the tendency for the alkali resistance of the cured film obtained from a curable resin composition to become favorable that the molecular weight between calculation network crosslinking points is below the said upper limit. 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 alkali 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 of a strong structure and excellent alkali 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.

[Cured product]
The curable resin composition of this invention can be made into the hardened | cured material of this invention by irradiating an active energy ray so that it may mention later. Although the form in particular of the hardened | cured material of this invention is not limited, It is preferable to set it as the form of a cured film.

The cured product 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 50-1,500mJ / 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.

  When the cured product of the present invention is obtained in the form of a cured film cured film, the film thickness is appropriately determined according to the intended use, but is preferably 1 μm or more, more preferably 3 μm or more. Moreover, it is preferably 100 μm or less, more preferably 50 μm or less, and particularly preferably 20 μm or less. 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 product 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 a cured product is formed on the substrate of the present invention. However, the layer other than the substrate and the cured product of the present invention includes the substrate and the cured product of the present invention. You may have between and may have on the outer side. Moreover, the laminated body of this invention may have multiple layers of the base material and the hardened | cured material of this invention.

  As a method of obtaining a laminate having a multi-layered cured product, 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. However, from the viewpoint of enhancing the adhesion between the layers, a method of curing with active energy rays after laminating in an uncured state is preferable. 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 form is mentioned. Among these, polyester is preferable, and polyethylene terephthalate is particularly preferable.

  The cured product of the present invention and a laminate obtained by forming the cured product on a substrate 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 product 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]
The evaluation method of the physical property of polycarbonate diol in the following production examples is as follows.

<Quantitative determination of phenoxy group content and phenol content of polycarbonate diol>
Polycarbonate diol was dissolved in CDCl ₃ , 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, phenoxy group and phenol were identified from the signal position of each component, and each content was determined from the integral value. Was calculated. The ratio of the phenoxy group is determined from the ratio of the integral value for one proton of the phenoxy group to the integral value for one proton of the entire terminal, and the detection limit of the phenoxy group is 0.05% with respect to the entire terminal. Moreover, the detection limit of phenol content is 100 ppm as the weight of phenol with respect to the weight of the whole sample.

<Molar ratio of structural unit derived from 1,4-butanediol (1,4-BD) and structural unit derived from 1,10-decanediol (1,10-DD)>
Polycarbonate diol was dissolved in CDCl ₃ , 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, and from the signal position of each component and its integrated value, a structural unit derived from 1,4-BD and The molar ratio with the structural unit derived from 1,10-DD was determined.

<Hydroxyl value (OH value) and number average molecular weight in terms of hydroxyl value (Mn (OHV))>
Based on JIS K1557-1, the hydroxyl value of polycarbonate diol was measured by a method using an acetylating reagent, and Mn (OHV) was calculated from the value by the following formula.
Mn (OHV) = 56.1 × 2 × 1000 / (hydroxyl value)

<Measurement of APHA value>
According to JIS K0071-1 (1998), the APHA value was measured by comparing a melted polycarbonate diol with a standard solution in a colorimetric tube. As a reagent, a chromaticity standard solution of 1000 degrees (1 mg Pt / mL) (Kishida Chemical) was used.

<Physical properties of urethane (meth) acrylate oligomer and cured product>
In the following Examples and Comparative Examples, the physical properties of urethane (meth) acrylate oligomers and cured products, and methods for measuring and evaluating the properties are as follows.

1-1) Molecular weight of urethane (meth) acrylate oligomer GPC (“HLC-8120GPC” manufactured by Tosoh Corporation), THF as a solvent, polystyrene as a standard sample, TSKgel superH1000 + H2000 + H3000 as a column, and a liquid feeding speed of 0.5 mL / The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the urethane (meth) acrylate oligomer were measured at a column oven temperature of 40 ° C.

2-1) Evaluation of alkali resistance (NaOH resistance) Two drops of 10% by mass aqueous sodium hydroxide were brought into contact with the cured film laminated on polyethylene terephthalate obtained by the film-forming method I described later, and the dish was turned upside down. After coating and allowing to stand at 23 ° C. for 24 hours, the degree of contamination after wiping off contaminants with absorbent cotton containing water was evaluated by visual observation. The contact conditions and evaluation criteria for each contaminant are as follows.
○: Good state after wiping off contaminants ×: Poor state after wiping off contaminants

2-2) Evaluation of processing suitability (breaking elongation) after curing A cured film of the film forming method II described later is cut into a width of 10 mm, and a Tensilon tensile tester ("RTC-1210A" manufactured by Orientec Co., Ltd.) is used. The elongation at break was measured by performing a tensile test under the conditions of a temperature of 23 ° C., a humidity of 55% RH, a tensile speed of 50 mm / min, and a distance between chucks of 50 mm. If the elongation at break was 80% or more, it was evaluated that the processability after curing was good.

<Physical properties of cured film>
(Film Formation Method I) For NaOH Resistance Measurement The curable resin composition was 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 an electron beam irradiation device (CB175, Using a graphic), the dried coating film was irradiated with an electron beam under the conditions of an acceleration voltage of 165 kV and an irradiation dose of 5 Mrad, and further cured at 23 ° C. for one day to form a cured film, and the film thickness was about 5 μm. A cured film having a film laminated on polyethylene terephthalate was obtained. About the obtained cured film, the physical-property evaluation of said 2-1) was performed.

(Film formation method II) For coating film property measurement A curable resin composition was coated on a polyethylene terephthalate film with a 4 mil applicator to form a coating film, and then dried at 60 ° C. for 1 minute, and an electron beam irradiation device ( CB175, manufactured by Igraphic Co., Ltd.), a dried coating film was irradiated with an electron beam under the conditions of an acceleration voltage of 165 kV and an irradiation dose of 5 Mrad, and further cured at 23 ° C. for 1 day to form a cured film, and then a polyethylene terephthalate film Then, the cured film was peeled off to obtain a cured film having a thickness of about 20 μm. About the obtained cured film, the physical property evaluation of said 2-2) was performed about the obtained cured film.

[Production Example 1]
In a 5 L glass separable flask equipped with a stirrer, a distillate trap and a pressure regulator, 1,4-BD: 1355.8 g, 1,10-DD: 391.8 g, diphenyl carbonate: 2452.5 g, magnesium acetate Tetrahydrate aqueous solution: 8.4 mL (concentration: 8.4 g / L, magnesium acetate tetrahydrate: 74 mg) was added and replaced with nitrogen gas. Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Next, the pressure is lowered to 9.3 kPa over 120 minutes, and further lowered to 0.7 kPa over 30 minutes to continue the reaction, and then the temperature is raised to 170 ° C. to remove phenol and unreacted dihydroxy compounds out of the system. The mixture was reacted for 90 minutes to obtain polycarbonate diol. Table 1 shows the evaluation results of properties and physical properties of the obtained polycarbonate diol.

[Raw materials / solvents]
The raw materials and solvents used in the following examples and comparative examples are as follows.

<Compound (A)>
・ IPDI: Isophorone diisocyanate (Evonik Degussa Japan, trade name “VESTANAT IPDI”)

<Compound (B)>
Polycarbonate diol produced in Production Example 1 T4691: Polycarbonate diol T4691 (1,4-butanediol / 1,6-hexanediol (90:10 (molar ratio)) manufactured by Asahi Kasei Co., hydroxyl value: 118.7 , Mn (OHV): 945)

<Compound (C)>
V-300: Mixture (catalog value) containing 40 to 45% by weight of pentaerythritol triacrylate as compound (C) and 35 to 40% by weight of pentaerythritol tetraacrylate as the other compound (trade name, manufactured by Osaka Organic Chemical Co., Ltd.) Biscoat 300) was used.

<Organic solvent>
MEK: Methyl ethyl ketone

[Production and evaluation of urethane (meth) acrylate and cured film]
<Example 1>
In a four-necked flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 85.3 g (0.384 mol) of IPDI and 300 g (0.288 mol) of the polycarbonate diol synthesized in Production Example 1 were placed. Further, 257 g of methyl ethyl ketone and 0.03 g of dioctyltin dilaurate were added and reacted for 5 hours while heating to 60 ° C. in an oil bath. After cooling to 50 ° C. after completion of the reaction, 0.1 g of dioctyltin dilaurate, 0.3 g of methylhydroquinone and 67 g of methyl ethyl ketone were added, and 100 g of V-300 (converted to 0.196 mol in terms of pentaerythritol triacrylate (PETA)) was added dropwise. The reaction was started. The reaction was carried out for 8 hours while heating to 70 ° C. in an oil bath. After confirming the end point of the reaction by disappearance of the peak derived from the isocyanate (NCO) group in the infrared absorption spectrum, 162 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). Moreover, the curable resin composition was formed into a film by the above-mentioned film forming method, and said 2-1) and 2-2) were evaluated. The obtained results are shown in Table-2.

<Comparative Example 1>
In a four-necked flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 94 g (0.423 mol) of IPDI, 300 g (0.317 mol) of polycarbonate diol T4691 manufactured by Asahi Kasei Co., and 262 g of methyl ethyl ketone, Dioctyltin dilaurate (0.03 g) was added and reacted for 6 hours while heating to 80 ° C. in an oil bath. After cooling to 60 ° C. after completion of the reaction, 0.12 g of dioctyltin dilaurate, 0.25 g of methylhydroquinone and 73 g of methyl ethyl ketone were further added, and 110 g (0.216 mol in terms of PETA) 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, 168 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 2-1) and 2-2) were evaluated. These results are shown in Table-2.

[Evaluation results]
As shown in Table 2, it can be seen that the cured film of Example 1 corresponding to the present invention is superior to that of Comparative Example 1 in the balance between alkali resistance and processability after curing.

Claims (14)

A urethane (meth) acrylate oligomer obtained by reacting at least the following compound (A), compound (B) and compound (C).
Compound (A): Polyisocyanate compound (B): Polycarbonate diol compound (C) having a structural unit derived from an alkylene glycol having 7 to 14 carbon atoms: Hydroxyalkyl (meth) acrylate   The urethane (meth) acrylate oligomer according to claim 1, wherein the number average molecular weight (Mn) is 1,000 to 10,000.   The urethane (meth) acrylate oligomer according to claim 1 or 2, wherein the compound (B) has a number average molecular weight (Mn (OHV)) of 500 to 5,000.   The urethane (meth) acrylate oligomer according to any one of claims 1 to 3, wherein the compound (B) further has a structural unit derived from an alkylene glycol having 2 to 6 carbon atoms.   In the compound (B), the molar ratio of the structural unit derived from an alkylene glycol having 7 to 14 carbon atoms and the structural unit derived from an alkylene glycol having 2 to 6 carbon atoms is 1:99 to 99: 1. The urethane (meth) acrylate oligomer according to claim 4.   The urethane (meth) acrylate oligomer according to any one of claims 1 to 5, wherein the alkylene glycol having 7 to 14 carbon atoms is 1,10-decanediol.   The urethane (meth) acrylate oligomer according to any one of claims 4 to 6, wherein the alkylene glycol having 2 to 6 carbon atoms is 1,4-butanediol.   The urethane (meth) acrylate oligomer according to any one of claims 1 to 7, wherein the compound (A) is a polyisocyanate having an alicyclic structure.   The urethane (meth) acrylate oligomer according to any one of claims 1 to 8, wherein the compound (C) is a hydroxyalkyl poly (meth) acrylate.   The compound (A) and the compound (B) are reacted to obtain a urethane prepolymer, and then the compound (C) is reacted with the compound, thereby obtaining the urethane prepolymer. The urethane (meth) acrylate oligomer described in 1.   A curable resin composition comprising the urethane (meth) acrylate oligomer according to any one of claims 1 to 10 and an organic solvent.   A cured product obtained by irradiating the curable resin composition according to claim 11 with active energy rays.   The laminated body formed by forming the hardened | cured material of Claim 12 on a base material.   The laminated body of Claim 13 whose said base material is polyester.