Hardened composition

Abstract

To provide a curable composition, preferably an active energy ray-curable composition excellent in curability with a low viscosity, making the cured film excellent in cohesion force, and specifically, containing a polyfunctional urethane (meth)acrylate excellent in peel strength and repeelability without causing adhesive deposits.SOLUTION: A curable composition contains (A) a component. The (A) component: a reaction product of a polyol, an organic polyisocyanate, and a mixture (a1) which is a mixture of at least one kind of compound selected from the group consisting of a glycerol (meth)acrylate and a diglycerol (meth)acrylate, and has a hydroxyl value of 20-300 mgKOH / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition containing a urethane (meth)acrylate having two or more (meth)acryloyl groups (hereinafter referred to as "polyfunctional urethane (meth)acrylate"), and preferably to an active energy ray-curable composition. The composition of the present invention can be used for various applications, and in particular, it has faster curing properties than conventional polyfunctional urethane (meth)acrylates, and the composition gives a cured film with excellent strength and cohesive force. Therefore, the composition can be preferably used as an adhesive, pressure-sensitive adhesive, and sealant, and belongs to these technical fields. In this specification, acryloyl and / or methacryloyl groups are referred to as (meth)acryloyl groups, acrylates and / or methacrylates as (meth)acrylates, and acrylic acid and / or methacrylic acid as (meth)acrylic acid. [Background technology]

[0002] Polyfunctional urethane (meth)acrylates are excellent in curability and in the tensile strength, elongation, and toughness of the cured film, and are therefore used in various curable compositions, particularly active energy ray-curable compositions, such as coating agents, inks, pressure-sensitive adhesives, adhesives, and sealants.

[0003] Among these applications, adhesives are used in various labels and tapes, taking advantage of their ability to be peeled off after application. Among these, adhesives with weak adhesive strength are also called removable adhesives, and because they have the ability to be easily peeled off from the substrate after a certain period of time after application, they are widely used as masking tape and protective films in applications such as construction, automobile manufacturing, and electronic devices. A more specific application of removable adhesives is removable adhesive-treated paper, which is used to removably bond the opposing surfaces of folded sheets that have general information and confidential information printed on the overlapping surfaces.In recent years, this has been widely used in various notices from the perspective of automating the production of notices and protecting personal information. This removable adhesive coated paper has pressure-sensitive removable adhesive layers on predetermined portions of the overlapping surfaces so that the overlapping surfaces can be bonded together. By bringing these removable adhesive layers into contact with each other and applying strong pressure, the two surfaces will adhere to each other during normal handling, and can be removed by peeling them off.

[0004] Pressure-sensitive adhesives are broadly classified into solvent-based pressure-sensitive adhesives, emulsion-based pressure-sensitive adhesives, solvent-free pressure-sensitive adhesives, etc. depending on their form. However, active energy ray-curable pressure-sensitive adhesives, which are a type of solvent-free pressure-sensitive adhesive, are attracting attention from the perspective of reducing the solvent used and energy costs. Active energy ray-curable pressure-sensitive adhesives differ from solvent-based pressure-sensitive adhesives and emulsion-based pressure-sensitive adhesives in that they do not require a process for removing solvents such as water when forming a pressure-sensitive adhesive layer. Therefore, in recent years, active energy ray-curable pressure-sensitive adhesives have been used as environmentally friendly pressure-sensitive adhesives in a variety of fields, such as image display devices, home appliances, information devices, automotive interior / exterior components, building materials, and labels.

[0005] As a solvent-free pressure-sensitive adhesive composition, a solvent-free composition containing a polyfunctional urethane (meth)acrylate as a main component is known. Patent Document 1 discloses a composition consisting of a bifunctional urethane (meth)acrylate and a compound having one (meth)acryloyl group (hereinafter referred to as "monofunctional (meth)acrylate"). However, although the composition of this patent is solvent-free and has low viscosity, it has low curing properties, so unreacted (meth)acrylate tends to remain in the adhesive layer, and there are problems with performance such as odor and adhesive residue when used as an adhesive tape.

[0006] As such, conventional bifunctional urethane (meth)acrylates used as raw materials for adhesives have a small number of (meth)acryloyl groups in the molecule, which means they have low curing properties and cohesive strength, and are prone to leaving adhesive residue, leaving room for improvement. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-5368 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have conducted extensive research to find a curable composition containing a multifunctional urethane (meth)acrylate that has low viscosity and excellent curability, and that produces a cured film with excellent cohesive strength, specifically excellent peel strength, and excellent removability without leaving any adhesive residue, and preferably to find an active energy ray-curable composition. [Means for solving the problem]

[0009] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that a curable composition containing, as essential components, a polyol, an organic polyisocyanate, and a polyfunctional urethane (meth)acrylate obtained by a urethanization reaction of glycerin (meth)acrylate and / or diglycerin (meth)acrylate has low viscosity and excellent curing properties, and the cured film produced thereby has excellent cohesive strength, specifically excellent peel strength, and excellent removability without leaving any adhesive residue, thereby completing the present invention. The present invention will be described in detail below. [Effects of the Invention]

[0010] The composition of the present invention has low viscosity and excellent curability, and the resulting cured film has excellent cohesive strength, specifically excellent peel strength, and excellent removability without leaving any adhesive residue. Therefore, the composition of the present invention can be preferably used for pressure-sensitive adhesives, adhesives, sealants, etc. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention relates to a curable composition comprising the following component (A): Component (A): A reaction product of mixture (a1) which is a mixture of a polyol, an organic polyisocyanate, and at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, and has a hydroxyl value of 20 to 300 mgKOH / g. The component (A), the curable composition, the method of use, and applications will be described below.

[0012] 1. (A) Component The component (A) of the present invention is a reaction product of a mixture (a1) [hereinafter referred to as "mixture (a1)"] which is a mixture of a polyol, an organic polyisocyanate, and at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, and has a hydroxyl value of 20 to 300 mgKOH / g. The methods for producing the polyol, the organic polyisocyanate, the mixture (a1), and the component (A) will be described below.

[0013] 1-1. Polyol Examples of polyols include low molecular weight diols, polyether polyols, polycarbonate polyols, polyester polyols, and diols having a polyene skeleton.

[0014] Examples of low molecular weight diols include ethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, nonanediol, cyclohexanedimethanol, neopentyl glycol, 3-methyl-1,5-pentanediol, and neopentyl glycol hydroxypivalic acid ester.

[0015] The polyether polyol may be a polyalkylene glycol having two or more oxyalkylene units, and specific examples thereof include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0016] Examples of polycarbonate polyols include reaction products of carbonates with the above-mentioned low-molecular-weight diols. Specific examples of carbonates include diaryl carbonates such as diphenyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

[0017] The polyester polyol may be, for example, a reaction product of at least one selected from the group consisting of the low-molecular-weight diols, polyether polyols, and polycarbonate polyols with an acid component. Specific examples of the acid component include dibasic acids such as adipic acid, sebacic acid, succinic acid, maleic acid, phthalic acid, hexahydrophthalic acid, and terephthalic acid, or anhydrides thereof, and ring-opening reaction products of polycarbonate diol and caprolactone.

[0018] Examples of diols having a polyene skeleton include diols having a polybutadiene skeleton, diols having a polyisoprene skeleton, diols having a hydrogenated polybutadiene skeleton, and diols having a hydrogenated polyisoprene skeleton. The above polyols may be used alone or in combination of two or more.

[0019] 1-2. Organic polyisocyanates Examples of organic polyisocyanates include diisocyanates and triisocyanates. Organic polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. Specific examples of aliphatic polyisocyanates include hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and the like, as well as biurets, isocyanurates, and reaction products of these compounds with polyhydric alcohols such as trimethylolpropane. Specific examples of alicyclic isocyanates include isophorone diisocyanate, norbornane diisocyanate, 2,5(2,6)-bis(isocyanatomethyl)bicyclo[2,2,1]heptane, hydrogenated tolylene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane, as well as biurets, isocyanurates, and reaction products of these compounds with polyhydric alcohols such as trimethylolpropane. Specific examples of aromatic isocyanates include tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and the like, as well as biurets, isocyanurates, and reaction products of these compounds with polyhydric alcohols such as trimethylolpropane. As the organic polyisocyanate, aliphatic polyisocyanates and alicyclic polyisocyanates are preferred because they have excellent light resistance. As the organic polyisocyanate, an aliphatic polyisocyanate is more preferred, and hexamethylene diisocyanate is particularly preferred in that the composition has a low viscosity and the cured film has excellent cohesive strength and flexibility.

[0020] 1-3.Mixture (a1) The mixture (a1) is a mixture of at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, and has a hydroxyl value of 20 to 300 mgKOH / g.

[0021] When the mixture (a1) is a mixture of glycerin (meth)acrylate, a mixture containing glycerin diacrylate as the main component is preferred because it has excellent reactivity with organic polyisocyanates. In the case of a mixture of diglycerin (meth)acrylates, a mixture containing diglycerin triacrylate as a main component is preferred in terms of excellent reactivity with organic polyisocyanates.

[0022] The mixture (a1) can be obtained by a transesterification reaction between glycerin and / or diglycerin (hereinafter collectively referred to as "(poly)glycerin") and a monofunctional (meth)acrylate. Alternatively, the mixture (a1) can be obtained by a dehydration esterification reaction between (poly)glycerin and (meth)acrylic acid. When glycerin is used as a raw material, the mixture (a1) is a mixture of glycerin mono(meth)acrylate, di(meth)acrylate, and tri(meth)acrylate. When diglycerin is used as a raw material, the mixture (a1) is a mixture of diglycerin mono(meth)acrylate, and di(meth)acrylate, tri(meth)acrylate, and tetra(meth)acrylate. The mixture (a1) is a mixture of at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, and has a hydroxyl value of 20 to 300 mgKOH / g, preferably 30 to 290 mgKOH / g, more preferably 40 to 280 mgKOH / g. If the hydroxyl value of mixture (a1) is less than 20 mgKOH / g, the cohesive strength of the resulting composition containing component (A) will be reduced, whereas if the hydroxyl value exceeds 300 mgKOH / g, the viscosity of the resulting component (A) will be too high and the water resistance of the cured film will be reduced. In the present invention, the hydroxyl value means a value measured in accordance with the method specified in JIS K0070-1992.

[0023] Furthermore, as a mixture of glycerin (meth)acrylate, a mixture containing glycerin di(meth)acrylate (hereinafter also referred to as "GLY-DA") is more preferable. GLY-DA is a compound represented by the following formula (1) or (2).

[0024] [ka]

[0025] [In the above formula (1), R 1 and R 2 each independently represents a hydrogen atom or a methyl group.

[0026] [ka]

[0027] [In the above formula (2), R 3 and R 4 each independently represents a hydrogen atom or a methyl group.

[0028] Unless specially purified, GLY-DA is obtained as a mixture of the compound represented by formula (1) and the compound represented by formula (2) during production, and therefore these can be used as is. There are no particular restrictions on the mixing ratio of the compound represented by formula (1) and the compound represented by formula (2), and there is no problem with using them in any ratio.

[0029] The purity of GLY-DA contained in mixture (a1), as calculated using the following formula (3), is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more. By ensuring that the purity of GLY-DA is 30% or more, component (A), which is a reaction product of polyol and organic polyisocyanate, can be made to have excellent curability, and the cured film can have excellent cohesion properties.

[0030] GLY-DA purity (%) = [(D×2) / (M+D / 2+T / 3)]×100 ...Equation (3) D, M, and T in formula (3) represent the following values ​​obtained by analyzing mixture (a1) using a high-performance liquid chromatograph (hereinafter also referred to as "HPLC") equipped with an ultraviolet (UV) detector. D: GLY-DA peak area at 210 nm M: Peak area of ​​glycerin mono(meth)acrylate at 210 nm T: Peak area of ​​glycerin tri(meth)acrylate at 210 nm The peak area by HPLC means a value measured under the following conditions. Detector: UV detector, detection wavelength 210nm Column type: Column packed with silica gel modified with an alkyl group containing 18 carbon atoms Specifically, Waters ACQUITY UPLC BEH C18 (Part No. 186002350, column inner diameter 2.1 mm, column length 50 mm) Column temperature: 40℃ Eluent composition: A mixture of 0.03% by weight of trifluoroacetic acid in water and methanol Eluent flow rate: 0.3 mL / min

[0031] The mixture (a1) may be obtained by various production methods. For example, it may be obtained by a transesterification reaction between (poly)glycerin and a monofunctional (meth)acrylate in the presence of a transesterification catalyst, or by dehydration esterification of (poly)glycerin and (meth)acrylic acid in the presence of an acidic catalyst.

[0032] Among the above-mentioned production methods, the mixture (a1) obtained by the transesterification reaction of (poly)glycerin and a monofunctional (meth)acrylate is preferred because it contains fewer impurities and can produce the desired (meth)acrylate.

[0033] Furthermore, the transesterification reaction is preferably a transesterification reaction between (poly)glycerin and a monofunctional (meth)acrylate in the presence of catalysts X and Y described below. Catalyst X: One or more compounds selected from the group consisting of cyclic tertiary amines having an azabicyclo structure or salts or complexes thereof (hereinafter also referred to as "azabicyclo compounds"), amidines or salts or complexes thereof (hereinafter also referred to as "amidine compounds"), compounds having a pyridine ring or salts or complexes thereof (hereinafter also referred to as "pyridine compounds"), and phosphines or salts or complexes thereof (hereinafter also referred to as "phosphine compounds"). Catalyst Y: A compound containing zinc.

[0034] Examples of monofunctional (meth)acrylates include alkyl (meth)acrylates having an alkyl group having 1 to 8 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; alkoxyalkyl (meth)acrylates, such as 2-methoxyethyl acrylate; and N,N-dimethylaminoethyl (meth)acrylate. As the monofunctional (meth)acrylate, an alkoxyalkyl (meth)acrylate having an alkyl group with 1 to 2 carbon atoms, which promotes dissolution of (poly)glycerin and exhibits extremely good reactivity, is preferred, and 2-methoxyethyl (meth)acrylate is more preferred. As the monofunctional (meth)acrylate, acrylate is particularly preferred due to its excellent reactivity.

[0035] Among the above-mentioned compounds, the catalyst X is preferably one or more compounds selected from the group consisting of azabicyclo compounds, amidine compounds, and pyridine compounds. These compounds have excellent catalytic activity and can preferably produce the mixture (a1). In addition, they form a complex with the catalyst Y described below after the reaction is complete, and the complex can be easily removed from the reaction solution after the reaction is complete by a simple method such as adsorption. In particular, the azabicyclo compounds can be even more easily removed by filtration, adsorption, etc., because the complex with the catalyst Y is poorly soluble in the reaction solution.

[0036] Preferred examples of catalyst X include azabicyclo compounds such as quinuclidine, 3-quinuclidinone, 3-hydroxyquinuclidine, triethylenediamine (also known as 1,4-diazabicyclo[2.2.2]octane, hereinafter also referred to as "DABCO"), N-methylimidazole, 1,8-diazabicyclo[5.4.0]undec-7-ene (hereinafter also referred to as "DBU"), and 1,5-diazabicyclo[4.3.0]non-5-ene (hereinafter also referred to as "DBN"), and an example of an amidine compound such as N,N-dimethyl-4-aminopyridine (hereinafter also referred to as "DMAP"). Among these, 3-hydroxyquinuclidine, DABCO, N-methylimidazole, DBU, and DMAP are more preferred because they exhibit good reactivity with most polyhydric alcohols and are easily available.

[0037] As the catalyst Y, various compounds containing zinc can be used, but organic acid zinc and zinc diketone enolate are preferred because of their excellent reactivity. As the catalyst Y, examples of zinc organic acids such as zinc acetate, zinc propionate, zinc acrylate and zinc methacrylate are preferred, and examples of zinc diketone enolates such as zinc acetylacetonate are preferred. Among these, zinc acetate, zinc acrylate, and zinc acetylacetonate are preferred as catalyst Y, as they exhibit particularly good reactivity with most polyhydric alcohols and are readily available.

[0038] While there are no particular restrictions on the proportions of catalyst X and catalyst Y used in the method for producing mixture (a1), it is preferable to use 0.005 to 10.0 moles, and more preferably 0.05 to 5.0 moles, of catalyst X per mole of catalyst Y. By using 0.005 moles or more of catalyst X per mole of catalyst Y, it is possible to increase the amount of the target polyfunctional (meth)acrylate produced, while by using 10.0 moles or less, it is possible to suppress the production of by-products and coloration of the reaction solution and simplify the purification step after completion of the reaction.

[0039] A preferred combination of catalyst X and catalyst Y is one in which catalyst X is an azabicyclo-based compound and catalyst Y is an organic zinc acid, and a particularly preferred combination is one in which the azabicyclo-based compound is DABCO and the organic zinc acid is zinc acetate and / or zinc acrylate. This combination not only allows the production of mixture (a1) in good yield, but also provides an excellent color tone after the reaction (e.g., little yellowing), making it suitable for applications where colorless transparency is important, such as clear varnishes and hard coats. Furthermore, the catalysts mentioned above are available at relatively low cost, making this an economically advantageous production method.

[0040] The reaction temperature in the method for producing mixture (a1) is preferably 40 to 180° C., more preferably 60 to 160° C. Setting the reaction temperature to 40° C. or higher can increase the reaction rate, while setting the reaction temperature to 180° C. or lower can suppress thermal polymerization of (meth)acryloyl groups in the raw materials or product, suppress coloration of the reaction solution, and simplify the purification step after completion of the reaction.

[0041] The reaction pressure in the production of the mixture (a1) is not particularly limited as long as the predetermined reaction temperature can be maintained, and the reaction may be carried out under reduced pressure or increased pressure. The reaction pressure is preferably 0.000001 to 10 MPa (absolute pressure).

[0042] In the method for producing the mixture (a1), a monohydric alcohol derived from the monofunctional (meth)acrylate may be produced as a by-product as the transesterification reaction proceeds. When a portion (for example, about 50 mol%) of the hydroxyl groups of (poly)glycerin is (meth)acrylated, the monohydric alcohol is allowed to coexist in the reaction system to achieve an equilibrium state, the catalyst is removed by adsorption or deactivated, and then the monohydric alcohol and the raw material monofunctional (meth)acrylate are distilled off, whereby a product with a controlled acrylate rate can be stably produced.

[0043] In the method for producing the mixture (a1), the reaction can be carried out without using a solvent, but a solvent may be used if necessary. Specific examples of the solvent include hydrocarbons, ethers, crown ethers, esters, ketones, carbonate compounds, sulfones, sulfoxides, ureas or derivatives thereof, phosphine oxides, ionic liquids, silicone oil, and water. Among these solvents, hydrocarbons, ethers, carbonate compounds and ionic liquids are preferred. These solvents may be used alone or in any combination of two or more to form a mixed solvent.

[0044] In the method for producing the mixture (a1), an inert gas such as argon, helium, nitrogen, or carbon dioxide may be introduced into the system to maintain a good color tone of the reaction solution, but an oxygen-containing gas may also be introduced into the system to prevent polymerization of the (meth)acryloyl group. Specific examples of the oxygen-containing gas include air, a mixed gas of oxygen and nitrogen, and a mixed gas of oxygen and helium. The oxygen-containing gas may be introduced by dissolving it in the reaction solution or by bubbling it into the reaction solution.

[0045] In the method for producing the mixture (a1), it is preferable to add a polymerization inhibitor to the reaction liquid in order to prevent polymerization of the (meth)acryloyl group. Examples of the polymerization inhibitor include organic polymerization inhibitors, inorganic polymerization inhibitors, and organic salt polymerization inhibitors. Specific examples of organic polymerization inhibitors include phenolic compounds such as hydroquinone, tert-butylhydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, and 4-tert-butylcatechol; quinone compounds such as benzoquinone; phenothiazine, N-nitroso-N-phenylhydroxylamine ammonium; and N-oxyl compounds. Examples of the N-oxyl compounds include 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl. Among the compounds described above, it is preferable to use an N-oxyl compound as the polymerization inhibitor. As the N-oxyl compound, the compounds described above are preferable. Furthermore, as the polymerization inhibitor, it is preferable to use an N-oxyl compound in combination with another polymerization inhibitor. In this case, the polymerization inhibitor other than the N-oxyl compound is preferably a phenolic compound or phenothiazine, more preferably a phenolic compound. The polymerization inhibitor may be added singly or in any combination of two or more kinds, and may be added from the beginning or during the production process of the mixture (a1). The desired amount may be added all at once or in portions. The polymerization inhibitor may also be added continuously via a rectification column. The proportion of the polymerization inhibitor added is preferably 5 to 30,000 wtppm, more preferably 25 to 10,000 wtppm, based on the total weight of the reaction solution. By adding the polymerization inhibitor at a proportion of 5 wtppm or more, the polymerization inhibitor effect can be exhibited, and by adding the polymerization inhibitor at a proportion of 30,000 wtppm or less, coloration of the reaction solution can be suppressed, the purification step after the reaction can be simplified, and a decrease in the curing rate of the resulting mixture (a1) can be suppressed.

[0046] 1-4. Manufacturing method of component (A) The component (A) can be produced by heating and stirring a polyol, an organic polyisocyanate, and the mixture (a1) in the presence of a catalyst and a solvent, if necessary, to form a urethane. In this case, the polyol, the organic polyisocyanate, and the mixture (a1) can be charged all at once and reacted (hereinafter referred to as a "one-stage reaction"), or the polyol and the organic polyisocyanate can be reacted to produce an isocyanate group-containing prepolymer, and then the mixture (a1) can be added (hereinafter referred to as a "two-stage reaction"). The component (A) is preferably produced by a two-stage reaction, since this allows for the component (A) to be produced in an efficient manner without the reaction solution becoming highly viscous during the reaction, which would make the reaction difficult.

[0047] By reacting a polyol with an organic polyisocyanate, an isocyanate group-containing prepolymer having repeating units in the molecule is produced. By making the total amount of isocyanate groups in the organic polyisocyanate greater than the total amount of hydroxyl groups in the polyol, it is possible to produce a molecule having an isocyanate group at the molecular terminal, which can be suitably used as an isocyanate group-containing prepolymer.

[0048] As the isocyanate group-containing prepolymer, a compound having a molecular weight that is usually considered to be an oligomer can be used. The difference between oligomers and polymers lies in the number of repeating units in the molecule, and although there is no clear academic distinction between them, in the present invention, molecules with 1 to 100 repeating units in the molecule are called oligomers, and molecules with more than 100 repeating units are called polymers. The repeating units in the isocyanate group-containing prepolymer can be controlled by adjusting the ratio of the polyol to the organic polyisocyanate.

[0049] When producing an isocyanate group-containing prepolymer, the ratio of polyol to organic polyisocyanate may be appropriately set depending on the molecular weight and structure of the component (A) that is ultimately to be obtained. Specifically, the total amount of isocyanate groups in the organic polyisocyanate is preferably 1.05 to 2 moles per mole of the total amount of hydroxyl groups in the polyol. During the production of the isocyanate group-containing prepolymer, a small amount of a chain extender may be added for the purpose of adjusting the molecular weight. Examples of the chain extender include the same low-molecular-weight polyols as those mentioned above.

[0050] The above reaction proceeds without a catalyst, but in order to make the reaction proceed efficiently in a short time, a catalyst that is usually used in urethanization reactions can be used during synthesis. Specific examples of the catalyst include tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, and dibutyltin diacetylacetonate; bismuth compounds such as bismuth dioctate; iron compounds such as iron acetylacetonate; zinc compounds such as zinc acetylacetonate; and amine compounds such as triethylamine. The above catalysts may be used alone or in combination of two or more.

[0051] The amount of catalyst to be added may be a catalytic amount, for example, preferably 0.01 to 1,000 wtppm, more preferably 0.1 to 1,000 wtppm, relative to the reaction solution. By adding the catalyst in an amount of 0.01 wtppm or more, the urethane reaction can be favorably promoted, and by adding the catalyst in an amount of 1,000 wtppm or less, coloration of the resulting component (A) can be suppressed.

[0052] In the case of a one-stage reaction, the catalyst is preferably added when the polyol, the organic polyisocyanate, and the mixture (a1) are charged, and in the case of a two-stage reaction, the catalyst is preferably added when the polyol and the organic polyisocyanate are charged. Furthermore, the catalyst can also be added when the isocyanate group-containing prepolymer obtained by production is reacted with the mixture (a1), which is preferable in terms of shortening the reaction time.

[0053] If the molecular weight of component (A) produced by this reaction becomes high, the reaction mixture will become highly viscous and may become difficult to stir. For this reason, a solvent may be added to the reaction components. The solvent is preferably one that does not participate in the urethane-forming reaction, and examples thereof include organic solvents such as aromatic solvents such as toluene and xylene, and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. When an organic solvent is used, the amount added can be set appropriately depending on the viscosity of the resulting component (A), but it is preferable to set it so that it accounts for 0 to 70% by mass in the reaction solution. Here, the reaction solution means the total amount of raw material compounds when only raw material compounds are used, and means the total amount including a reaction solvent and the like when a reaction solvent and the like are used in addition to the raw material compounds. Specifically, it means a solution containing a polyol, an organic polyisocyanate, the mixture (a1), and optionally a catalyst, a solvent, a polymerization inhibitor, and the like.

[0054] As a solvent, a (meth)acrylate can be blended together with the organic solvent or in place of the organic solvent. Examples of the (meth)acrylate include a compound having an ethylenically unsaturated group other than the component (A) described below (hereinafter referred to as "component (B)"). A curable composition containing the resulting component (A) and a (meth)acrylate can be produced by carrying out a urethane reaction in the presence of such a (meth)acrylate. This composition is preferable because, unlike the case where an organic solvent is added, the composition does not need to be dried after application. When the (meth)acrylate used as a solvent is blended into the reaction solution, the blending amount may be appropriately set depending on the proportion of other (meth)acrylates to be blended into the final composition. For example, it is preferable to set the blending amount so that it is 0 to 70 mass %, and more preferably 0 to 50 mass %, in the reaction solution.

[0055] In the urethanization reaction, it is preferable to use a polymerization inhibitor to prevent polymerization of the (meth)acryloyl group of the raw material or the product, and further, an oxygen-containing gas may be introduced into the reaction solution. Examples of the oxygen-containing gas include air, a mixed gas of oxygen and nitrogen, and a mixed gas of oxygen and helium. etc. Examples of the polymerization inhibitor include organic polymerization inhibitors, inorganic polymerization inhibitors, and organic salt polymerization inhibitors. Specific examples of organic polymerization inhibitors include phenolic compounds such as hydroquinone, tert-butylhydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, and 4-tert-butylcatechol, quinone compounds such as benzoquinone, stable radicals such as galvinoxyl, 2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, phenothiazine, and N-nitroso-N-phenylhydroxylamine ammonium. Specific examples of inorganic polymerization inhibitors include copper chloride, copper sulfate, and iron sulfate. Specific examples of organic salt polymerization inhibitors include nitroso compounds such as N-nitroso-N-phenylhydroxylamine aluminum salt and ammonium N-nitrosophenylhydroxylamine, and copper dibutyldithiocarbamate. These can be used alone or in combination of two or more. The proportion of the polymerization inhibitor in the reaction liquid is preferably 5 to 20,000 wtppm, more preferably 25 to 3,000 wtppm.

[0056] The reaction temperature may be set appropriately depending on the raw materials used and the structure and molecular weight of the desired component (A), but is usually preferably 25 to 150° C., and more preferably 30 to 120° C. The reaction time may also be set appropriately depending on the raw materials used and the structure and molecular weight of the desired component (A), but is usually preferably 1 to 70 hours, and more preferably 2 to 30 hours.

[0057] The weight average molecular weight (hereinafter referred to as "Mw") of the component (A) in the present invention is preferably 3,000 to 200,000, more preferably 5,000 to 100,000, and even more preferably 10,000 to 50,000, from the viewpoint of improving the coatability and adhesive strength of the composition.

[0058] In the present invention, Mw refers to a value obtained by converting the molecular weight measured by gel permeation chromatography (hereinafter referred to as "GPC") into polystyrene equivalent, and means a value measured under the following conditions. Detector: Differential refractive index system (RI detector) Column type: Cross-linked polystyrene column Column temperature: 40℃ Eluent: tetrahydrofuran Molecular weight standard: Polystyrene

[0059] As the component (A), one type may be used alone, or two or more types may be used in combination.

[0060] 2.Curing composition The present invention relates to a curable composition containing the component (A). The composition can be produced by a conventional method, for example by stirring and mixing component (A) and, if necessary, other components. In this case, heating may be performed as necessary. The heating temperature may be appropriately set depending on the components contained in the composition used, the substrate to be coated with the composition, the purpose of use, etc., but a temperature of 30°C to 80°C is preferred.

[0061] When the composition contains the later-described component (B) [a compound having an ethylenically unsaturated group other than component (A)], the content of component (A) in the composition is preferably 1 to 90% by weight, more preferably 5 to 80% by weight, and even more preferably 10 to 50% by weight, based on 100% by weight of the total amount of components (A) and (B). By setting the proportion of component (A) to 1% by weight or more, the cured film of the composition can have excellent tensile strength and cohesive force, and by setting the proportion to 90% by weight or less, the composition can be prevented from becoming highly viscous, and favorable coatability can be achieved.

[0062] The viscosity of the composition may be appropriately set depending on the purpose, and is preferably 1 to 100,000 mPa·s. In the present invention, the viscosity refers to a value measured at 25°C using an E-type viscometer (cone-plate type viscometer).

[0063] The composition of the present invention is used as an active energy ray-curable composition and a heat-curable composition. The composition can be preferably used as an active energy ray-curable composition.

[0064] The composition of the present invention contains the above-mentioned (A) as an essential component, but various components can be blended depending on the purpose. Examples of other components include component (B) [a compound having an ethylenically unsaturated group other than component (A)], a photopolymerization initiator [hereinafter referred to as "component (C)"], an organic solvent, an antioxidant, an ultraviolet absorber, a pigment or dye, a leveling agent, a silane coupling agent, a surface modifier, and a polymer. These components will be described below. As for the other components described below, only one of the exemplified compounds may be used, or two or more of them may be used in combination.

[0065] 1)(B) Component Component (B) is an ethylenically unsaturated compound other than component (A) and is blended to impart various physical properties to the cured film of the composition. In this patent, the term "curable component" refers to a component that is cured by heat or active energy rays, and refers to components (A) and (B). Examples of the ethylenically unsaturated group in the component (B) include a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, and a (meth)allyl group, with a (meth)acryloyl group being preferred. In the following, "monofunctional" means a compound having one ethylenically unsaturated group, "○ functional" means a compound having ○ ethylenically unsaturated groups, and "polyfunctional" means a compound having two or more ethylenically unsaturated groups.

[0066] Specific examples of the monofunctional ethylenically unsaturated compound in component (B) include (meth)acrylic acid, a Michael addition dimer of acrylic acid, ω-carboxy-polycaprolactone mono(meth)acrylate, monohydroxyethyl phthalate (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl carbitol (meth)acrylate, butyl carbitol (meth)acrylate, 2-ethylhexyl carbitol (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, (meth)acrylates of alkylene oxide adducts of phenol, (meth)acrylates of alkylene oxide adducts of alkylphenol, cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. , 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, (meth)acrylate of alkylene oxide adduct of para-cumylphenol, orthophenylphenol (meth)acrylate, (meth)acrylate of alkylene oxide adduct of orthophenylphenol, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecane methylol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerin mono(meth)acrylate, mono(meth)acrylate of alkylene oxide adduct of isocyanuric acid, N-(2-(meth)acryloxyethyl)hexahydrophthalimide, N-(2-(meth)acryloxyethyl)tetrahydrophthalimide, N,N-dimethylacrylamide, acryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, and the like.

[0067] Specific examples of the bifunctional (meth)acrylate compound include polyethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, glycerin di(meth)acrylate, di(meth)acrylate of an alkylene oxide adduct of isocyanuric acid, di(meth)acrylate of an alkylene oxide adduct of bisphenol A, di(meth)acrylate of an alkylene oxide adduct of bisphenol F, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, and nonanediol di(meth)acrylate. In addition, epoxy (meth)acrylates having a bisphenol skeleton, a polyether skeleton, or a polyalkylene skeleton, urethane (meth)acrylates having a polyester skeleton, a polyether skeleton, or a polycarbonate skeleton, and polyester (meth)acrylates can also be used.

[0068] Examples of the tri- or higher functional (meth)acrylate compound include various compounds having three or more (meth)acryloyl groups, such as polyol poly(meth)acrylates such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, ditrimethylolpropane tri- or tetra(meth)acrylate, and dipentaerythritol tri-, tetra-, penta-, or hexa(meth)acrylate; Poly(meth)acrylates of polyol alkylene oxide adducts such as tri- or tetra(meth)acrylates of pentaerythritol alkylene oxide adducts, tri- or tetra(meth)acrylates of ditrimethylolpropane alkylene oxide adducts, and tri-, tetra-, penta-, or hexa(meth)acrylates of dipentaerythritol alkylene oxide adducts; Tri(meth)acrylates of alkylene oxide adducts of isocyanuric acid; and Examples include urethane (meth)acrylate, which is a reaction product of a compound having a hydroxyl group and three or more (meth)acryloyl groups, such as pentaerythritol tri(meth)acrylate, with an organic polyisocyanate. Examples of the alkylene oxide adducts include ethylene oxide adducts, propylene oxide adducts, and adducts of ethylene oxide and propylene oxide. Examples of the organic polyisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and a trimer of hexamethylene diisocyanate.

[0069] The content of component (B) is 0 to 99% by weight, more preferably 20 to 95% by weight, and even more preferably 50 to 90% by weight, based on 100 parts by weight of the total amount of components (A) and (B) (hereinafter, components (A) and (B) are collectively referred to as "curable components"). If the content of component (B) is less than 10% by mass, the composition will have high viscosity and its coatability will be reduced, whereas if it exceeds 99% by mass, the tensile strength and cohesive force of the composition may be reduced.

[0070] 2)(C) Component When the composition of the present invention is used as an active energy ray-curable composition and further as an electron beam-curable composition, it is also possible to cure the composition by electron beams without adding component (C) (photopolymerization initiator). When the composition of the present invention is used as an active energy ray-curable composition, particularly when ultraviolet light and visible light are used as the active energy rays, it is preferable that the composition further contain a (C) component from the viewpoints of ease of curing and cost. When electron beams are used as the active energy rays, it is not necessarily required to add the active energy rays, but a small amount can be added as needed to improve the curability.

[0071] Specific examples of component (C) include benzil dimethyl ketal, benzil, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, oligo[2-hydroxy-2-methyl-1-[4-1-(methylvinyl)phenyl]propanone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propan-1-one], methylvinylvinylphenyl]propanone ... aromatic ketone compounds such as 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butan-1-one, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-octylcarbazole, methyl phenylglyoxylate, ethyl anthraquinone, and phenanthrenequinone; benzophenone-based compounds such as benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4-(methylphenylthio)phenylphenylmethane, methyl-2-benzophenone, 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, and 4-methoxy-4'-dimethylaminobenzophenone; acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phenylphosphineate, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; Examples of the thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3-[3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl-oxy]-2-hydroxypropyl-N,N,N-trimethylammonium chloride, and fluorothioxanthone.

[0072] Among these compounds, α-hydroxyphenyl ketones are preferred because they have good surface curing properties even when used in thin film coatings under atmospheric conditions. Specifically, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-phenyl-propan-1-one are more preferred. Furthermore, when it is necessary to increase the thickness of the cured film, for example, when it is necessary to make it 50 μm or more, for the purpose of improving the curability inside the cured film, or when an ultraviolet absorber or pigment is used in combination, it is preferable to use an acylphosphine oxide compound such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-(2,4,6-trimethylbenzoyl)phenylphosphonate, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, or 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one in combination.

[0073] The content of component (C) is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the total amount of curable components. By making the content of component (C) 0.01 part by weight or more, the photocurability of the composition can be improved and excellent adhesion can be achieved, and by making it 15 parts by weight or less, the internal curability of the cured film can be improved and adhesion to the substrate can be improved.

[0074] 3) Thermal polymerization initiator When the composition is used as a thermosetting composition, a thermal polymerization initiator may be added. The composition of the present invention may be compounded with a thermal polymerization initiator and cured by heating. As the thermal polymerization initiator, various compounds can be used, and organic peroxides and azo-based initiators are preferred. Specific examples of organic peroxides include 1,1-bis(t-butylperoxy)2-methylcyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-dibutylperoxycyclohexyl)propane, 1, 1-bis(t-butylperoxy)cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di(m-toluoylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoe peroxyacetate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxyacetate, 2,2-bis(t-butylperoxy)butane, t-butyl peroxybenzoate, n-butyl-4,4-bis(t-butylperoxy)valerate, di-t-butylperoxyisophthalate, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane , t-butylcumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, and the like. Specific examples of azo compounds include 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, azodi-t-octane, and azodi-t-butane. These may be used alone or in combination of two or more. In addition, organic peroxides can be used in combination with a reducing agent to cause a redox reaction.

[0075] The amount of these thermal polymerization initiators used is preferably not more than 10 parts by weight per 100 parts by weight of the total amount of the curable components. When a thermal polymerization initiator is used alone, it may be carried out according to the usual means for normal radical thermal polymerization. In some cases, it may be used in combination with a photopolymerization initiator, and after photocuring, thermal curing may be carried out in order to further improve the reaction rate.

[0076] 4) Ingredients The composition of the present invention may contain an organic solvent for the purpose of improving the coating properties on the substrate.

[0077] Specific examples of organic solvents include alcohol compounds such as methanol, ethanol, isopropanol, and butanol; alkylene glycol monoether compounds such as ethylene glycol monomethyl ether and propylene glycol monomethyl ether; acetone alcohols such as diacetone alcohol; aromatic compounds such as benzene, toluene, and xylene; ester compounds such as propylene glycol monomethyl ether acetate, ethyl acetate, and butyl acetate; ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ether compounds such as dibutyl ether; and N-methylpyrrolidone. Among these, alkylene glycol monoether compounds and ketone compounds are preferred, and alkylene glycol monoether compounds are more preferred.

[0078] The content of the organic solvent is preferably 10 to 1,000 parts by weight, more preferably 50 to 500 parts by weight, and even more preferably 50 to 300 parts by weight, relative to 100 parts by weight of the total amount of the curable components. Within this range, the composition can be made to have a viscosity suitable for coating, and the composition can be easily coated by a known coating method described below.

[0079] 5) Antioxidants The antioxidant is added for the purpose of improving the durability of the cured film, such as heat resistance and weather resistance. Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of phenolic antioxidants include hindered phenols such as di-t-butylhydroxytoluene, etc. Commercially available antioxidants include AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, and AO-80 manufactured by Adeka Corporation. Examples of phosphorus-based antioxidants include phosphines such as trialkylphosphine and triarylphosphine, trialkyl phosphites, triaryl phosphites, etc. Commercially available derivatives of these antioxidants include Adeka STAB PEP-4C, PEP-8, PEP-24G, PEP-36, HP-10, 260, 522A, 329K, 1178, 1500, 135A, and 3010, manufactured by Adeka Corporation. Examples of sulfur-based antioxidants include thioether-based compounds, and commercially available products include AO-23, AO-412S, and AO-503A manufactured by Adeka Corporation. These antioxidants may be used alone or in combination of two or more. Preferred combinations of these antioxidants include a combination of a phenolic antioxidant and a phosphorus-based antioxidant, and a combination of a phenolic antioxidant and a sulfur-based antioxidant. The content of the antioxidant may be appropriately set depending on the purpose, and is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the total amount of the curable components. By making the content ratio 0.1 parts by weight or more, the durability of the composition can be improved, while by making it 5 parts by weight or less, the curability and adhesion can be improved.

[0080] 6) UV absorbers The ultraviolet absorber is added for the purpose of improving the light resistance of the cured film. Examples of the ultraviolet absorber include triazine-based ultraviolet absorbers such as TINUVIN 400, TINUVIN 405, TINUVIN 460, and TINUVIN 479, and benzotriazole-based ultraviolet absorbers such as TINUVIN 900, TINUVIN 928, and TINUVIN 1130, all of which are manufactured by BASF. The content of the ultraviolet absorber may be appropriately set depending on the purpose, and is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the total amount of the curable components. By setting the content to 0.01% by weight or more, the light resistance of the cured film can be improved, while by setting it to 5% by weight or less, the curability of the composition can be improved.

[0081] 7) Pigments and dyes Examples of the pigment include organic pigments and inorganic pigments. Specific examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow, and pyrazolone red; soluble azo pigments such as litol red, heliobordeaux, pigment scarlet, and permanent red 2B; derivatives of vat dyes such as alizarin, indanthrone, and thioindigo maroon; phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green; quinacridone organic pigments such as quinacridone red and quinacridone magenta; perylene organic pigments such as perylene red and perylene scarlet; and isoindoline. isoindolinone-based organic pigments such as perinone yellow and isoindolinone orange; pyranthrone-based organic pigments such as pyranthrone red and pyranthrone orange; thioindigo-based organic pigments; condensed azo-based organic pigments; benzimidazolone-based organic pigments; quinophthalone-based organic pigments such as quinophthalone yellow, isoindoline-based organic pigments such as isoindoline yellow; and other pigments such as flavanthrone yellow, acylamide yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, and dioxazine violet. Specific examples of the inorganic pigment include titanium oxide, barium sulfate, calcium carbonate, zinc oxide, lead sulfate, yellow lead, zinc yellow, red iron oxide (red iron (III) oxide), cadmium red, ultramarine, Prussian blue, chromium oxide green, cobalt green, umber, titanium black, and synthetic iron black. Carbon black, which is an example of the filler, can also be used as an inorganic pigment. As the dye, various conventionally known compounds can be used.

[0082] 8) Silane coupling agents The silane coupling agent is added for the purpose of improving the interfacial adhesive strength between the cured film and the substrate. There are no particular restrictions on the silane coupling agent, as long as it can contribute to improving adhesion to the substrate.

[0083] Specific examples of the silane coupling agent include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0084] The blending ratio of the silane coupling agent may be appropriately set depending on the purpose, and is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, per 100 parts by weight of the total amount of the curable components. By making the blending ratio 0.1 parts by weight or more, the adhesive strength of the composition can be improved, while by making it 10 parts by weight or less, it is possible to prevent the adhesive strength from changing over time.

[0085] 9) Surface modifiers A surface modifier may be added to the composition of the present invention for the purposes of improving leveling properties during application and increasing the slipperiness of the cured film to improve scratch resistance. Examples of the surface modifier include a surface conditioner, a surfactant, a leveling agent, an antifoaming agent, an agent for imparting smoothness, an agent for imparting antifouling property, etc., and these known surface modifiers can be used. Among them, silicone-based surface modifiers and fluorine-based surface modifiers are preferred. Specific examples include silicone-based polymers and oligomers having a silicone chain and a polyalkylene oxide chain, silicone-based polymers and oligomers having a silicone chain and a polyester chain, fluorine-based polymers and oligomers having a perfluoroalkyl group and a polyalkylene oxide chain, and fluorine-based polymers and oligomers having a perfluoroalkyl ether chain and a polyalkylene oxide chain. Furthermore, for the purpose of increasing the durability of the slipperiness, a surface modifier having an ethylenically unsaturated group, preferably a (meth)acryloyl group, in the molecule may be used.

[0086] The content of the surface modifier is preferably 0.01 to 1.0 parts by weight per 100 parts by weight of the total amount of the curable components.Within this range, the surface smoothness of the coating film is excellent.

[0087] 10) Polymer The composition of the present invention may further contain a polymer for the purpose of further improving the curl resistance of the resulting cured film. Suitable polymers include (meth)acrylic polymers, and suitable constituent monomers include methyl (meth)acrylate, cyclohexyl (meth)acrylate, (meth)acrylic acid, glycidyl (meth)acrylate, N-(2-(meth)acryloxyethyl)tetrahydrophthalimide, etc. In the case of a polymer copolymerized with (meth)acrylic acid, glycidyl (meth)acrylate may be added to introduce a (meth)acryloyl group into the polymer chain. The content of the polymer is preferably 0.01 to 10 parts by weight per 100 parts by weight of the total amount of the curable components.Within this range, the obtained cured film has better curl resistance.

[0088] The composition of the present invention may be used in a conventional manner. For example, a method of applying the composition to a substrate and then curing the composition by irradiating it with active energy rays or by heating the composition can be mentioned. Specifically, in the case of applications such as coating agents and adhesives, the composition is applied to a substrate by a normal coating method, and then, in the case of an active energy ray-curable composition, the composition is cured by irradiation with active energy rays, or in the case of a thermosetting composition, the composition is cured by heating. In the case of applications such as molding materials, the composition is poured into a predetermined mold, and then, in the case of an active energy ray-curable composition, the composition is cured by irradiation with active energy rays, or in the case of a thermosetting composition, the composition is cured by heating. The irradiation method of active energy rays and the heating method are the general methods known as conventional curing methods. It is best to adopt such a method. In addition, a method can also be employed in which the composition contains component (C) (photopolymerization initiator) and a thermal polymerization initiator in combination, and the composition is irradiated with active energy rays and then heat-cured to improve adhesion to the substrate.

[0089] The composition of the present invention can be applied to a variety of substrates, including plastics, wood, metals, inorganic materials, and paper. Specific examples of plastics include polyvinyl alcohol, cellulose acetate resins such as triacetyl cellulose and diacetyl cellulose, acrylic resins, polyethylene terephthalate, polycarbonate, polyarylate, polyethersulfone, cyclic polyolefin resins containing cyclic olefins as monomers such as norbornene, polyvinyl chloride, epoxy resins, and polyurethane resins. Wood includes natural wood and synthetic wood. Examples of metals include steel plates, metals such as aluminum and chromium, and metal oxides such as zinc oxide (ZnO) and indium tin oxide (ITO). Examples of inorganic materials include glass, mortar, concrete, and stone. Among these, plastic substrates are particularly preferred.

[0090] The thickness of the cured film of the composition on the substrate may be appropriately set depending on the purpose. The thickness of the cured film may be selected depending on the substrate to be used and the application of the substrate having the produced cured film, but is preferably 1 to 500 μm, more preferably 5 to 200 μm.

[0091] The method for applying the composition of the present invention to a substrate may be appropriately determined depending on the purpose, and examples include coating methods using a bar coater, applicator, doctor blade, dip coater, roll coater, spin coater, flow coater, knife coater, comma coater, reverse roll coater, die coater, lip coater, gravure coater, microgravure coater, etc.

[0092] Examples of active energy rays for curing the composition of the present invention include ultraviolet rays, visible light, and electron beams, with ultraviolet rays being preferred. Examples of ultraviolet irradiation devices include high-pressure mercury lamps, metal halide lamps, ultraviolet (UV) electrodeless lamps, and light-emitting diodes (LEDs). The irradiation energy should be set appropriately depending on the type of active energy ray and the compounding composition. For example, when using a high-pressure mercury lamp, the irradiation energy in the UV-A region is 10 to 10,000 mJ / cm. 2 is preferred, and 100 to 2,000 mJ / cm 2 is more preferred.

[0093] 4.Applications The composition of the present invention can be used in a variety of applications, specifically as a coating agent, a pressure sensitive adhesive, an adhesive, a sealant, and the like.

[0094] The composition of the present invention can be preferably used as an active energy ray-curable composition, and has excellent curability. The cured film thereof has excellent tensile strength and cohesive force, and therefore can be more preferably used as a pressure-sensitive adhesive, adhesive, and sealant. Suitable applications include, for example, pressure-sensitive adhesives, adhesives, and sealants used in front panels for display boards, building materials, lighting fixtures, displays and housings for mobile phones, smartphones, and tablet devices, housings for home appliances, and various lenses for eyeglasses and the like. Specific examples of the front panel for a display board include an electric bulletin board, a display, a signboard, an advertisement, and a sign. [Example]

[0095] The present invention will be described in more detail below with reference to examples and comparative examples. In the following description, "parts" means parts by weight.

[0096] 1. Manufacturing example 1) Manufacturing Example 1 [Production of mixture (a1)] A 3-liter flask equipped with a stirrer, thermometer, gas inlet tube, rectification column, and condenser was charged with 302.75 parts (3.29 mol) of glycerin (purified glycerin (trade name) manufactured by Sakamoto Pharmaceutical Co., Ltd.; hereinafter referred to as "GLY"), 2312.84 parts (17.77 mol) of 2-methoxyethyl acrylate (hereinafter referred to as "MCA"), 6.51 parts (0.06 mol) of DABCO as catalyst X, 24.07 parts (0.12 mol) of zinc acrylate as catalyst Y, 1.19 parts (0.01 mol) of hydroquinone monomethyl ether (hereinafter referred to as "MEHQ"), and 0.21 parts (0.002 mol) of phenothiazine, and an oxygen-containing gas (5% by volume oxygen, 95% by volume nitrogen) was bubbled into the liquid. While the reaction mixture was heated and stirred at a temperature in the range of 100 to 130°C, the pressure in the reaction system was adjusted to a range of 110 to 760 mmHg, and a mixture of MCA and 2-methoxyethanol (hereinafter referred to as "MEL"), which was by-produced as the transesterification reaction progressed, was withdrawn from the reaction system via a rectification column and a condenser. Furthermore, MCA in an amount equal to the weight of the withdrawn mixture was added to the reaction system as needed. 18 hours after the start of heating and stirring, the pressure in the reaction system was returned to normal pressure, and withdrawal was completed. The acrylate ratio of the hydroxyl groups of GLY was calculated from the amount of MEL produced and was found to be 57 mol %. The reaction mixture was cooled to room temperature, and the precipitate was filtered off. To remove catalyst X and catalyst Y from the filtrate, 58.7 parts of aluminum silicate (Kyoward 700SEN-S (trade name) manufactured by Kyowa Chemical Industry Co., Ltd., hereinafter referred to as "700SEN-S") was added and stirred. The mixture was then heated and stirred at 70 to 100°C for an additional hour. The adsorbed aluminum silicate was filtered off, and the filtrate was placed in a flask equipped with a stirrer, thermometer, gas inlet, distillation condenser, and pressure reduction tube. The mixture was subjected to vacuum distillation for 10 hours at a temperature of 70 to 100°C and a pressure of 0.001 to 100 mmHg while bubbling dry air through the flask. The distillate containing unreacted MCA was separated. 5.0 parts of diatomaceous earth (Radiolite (trade name) manufactured by Showa Chemical Industry Co., Ltd., hereinafter referred to as "Radiolite") was added to the filtrate, and the mixture was filtered under pressure. The resulting filtrate was designated mixture (a1). The yield of the mixture (a1) was 647 parts, which will hereinafter be referred to as mixture (a1-1). When all of the charged 302.75 parts of GLY were converted into glycerin diacrylate (hereinafter also referred to as "GLY-DA"), the yield would be 658 parts, and the yield of the above mixture (a1-1) calculated based on this was 98%. Using HPLC equipped with a UV detector, the purity of GLY-DA contained in mixture (a1-1) was calculated according to the following formula (3). The result was 63%, 23% for glycerin triacrylate (hereinafter referred to as "GLY-TA"), and 14% for glycerin monoacrylate (hereinafter referred to as "GLY-MA"). The resulting mixture (a1-1) had a viscosity of 41 mPa·s (25° C.), a hydroxyl value of 240 mgKOH / g, and an Mw of 309 as determined by GPC.

[0097] HPLC, viscosity, hydroxyl value and GPC were measured according to the following methods. ◆HPLC measurement conditions Equipment: Waters ACQUITY UPLC Detector: UV detector Detection wavelength: 210nm Column: Waters ACQUITY UPLC BEH C18 (Part No. 186002350, column inner diameter 2.1 mm, column length 50 mm) Column temperature: 40℃ Eluent composition: A mixture of 0.03% by weight of trifluoroacetic acid in water and methanol Eluent flow rate: 0.3 mL / min

[0098] ◆Method for calculating the purity of GLY-DA contained in mixture (a1-1) GLY-DA Purity % = [(D / 2) / (M+D / 2+T / 3)]×100...Equation (3) The symbols and terms in formula (1) have the following meanings: D: GLY-DA peak area at 210 nm M: GLY-MA peak area at 210 nm T: GLY-TA peak area at 210 nm

[0099] ◆Viscosity measurement conditions The viscosity was measured at 25°C using an E-type viscometer.

[0100] ◆Hydroxyl number measurement conditions Measurement was performed in accordance with JIS K0070-1992. That is, an acetylation reagent was added to the sample and heated in a warm bath. After cooling, the acid was titrated with a potassium hydroxide ethanol solution using a phenolphthalein solution as an indicator to determine the hydroxyl value. The amount of pyridine used was five times that of the method described in JIS K0070-1992.

[0101] GPC measurement conditions Apparatus: Waters GPC System Name 1515 2414 717P RI Detector: RI detector Column: Guard column: Showa Denko Shodex KFG (8 μm, 4.6 × 10 mm), two main columns: Waters Styragel HR 4E THF (7.8 × 300 mm) + Styragel HR 1THF (7.8 × 300 mm) Column temperature: 40℃ Eluent composition: THF (containing 0.03% sulfur as an internal standard), flow rate 0.75 mL / min

[0102] 2) Manufacturing Example 2 (Production of component (A)) A 1 L flask equipped with a stirrer, a thermometer, and a pipe for an oxygen / nitrogen mixed gas with an oxygen concentration of 5% (hereinafter referred to as 5% ON) was charged with 59.99 g of isophorone diisocyanate (hereinafter referred to as IPDI), 0.26 g of 2,6-di-t-butyl-4-methylphenol (hereinafter referred to as BHT), and 220.41 g of nonylphenoxyethyl acrylate (Aronix M-111 manufactured by Toagosei Co., Ltd.; hereinafter referred to as M-111) used as a diluent. The contents were stirred while blowing in 5% ON, and the temperature inside the flask was raised to 70°C. 0.005 g of iron tris(acetylacetonate) (Nippon Chemical Industry Co., Ltd., product name: Nursem ferric; hereafter referred to as Nursem) was added, followed by the gradual addition of a polyester diol (made from neopentyl glycol and adipic acid; product name: Polylite OD-X-2044, product of DIC Corporation) with a hydroxyl value of 55 mgKOH / g. A final total of 440.51 g of polyester was added. 2.43 g of 1,4-butanediol was then added, and the temperature inside the flask was raised to 80°C. When the Mw measured by GPC exceeded 32,000, 11.89 g of mixture (a1-1) was added. At this time, 0.005 g of Nursem was also added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was then terminated. The resulting reaction mixture was a mixture containing a tetrafunctional urethane acrylate (hereinafter referred to as "A-1") having a Mw of 43,000 as determined by GPC, and 30% of M-111.

[0103] 3) Manufacturing Example 3 (Production of component (A)) A 1 L flask equipped with a stirrer, a thermometer, and 5% ON piping was charged with 59.99 g of IPDI, 0.26 g of BHT, and 220.41 g of M-111 used as a diluent. The contents were stirred while blowing in 5% ON, and the temperature inside the flask was raised to 70°C. 0.005 g of Narcem was added, followed by the gradual addition of the same polyester diol with a hydroxyl value of 55 mgKOH / g as used in Production Example 2. Finally, 440.51 g of polyester was charged. The temperature inside the flask was then raised to 80°C. When the Mw of the contents measured by GPC exceeded 8,000, 11.89 g of mixture (a1-1) was added. At this time, 0.005 g of Nursem was also added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was then terminated. The resulting reaction mixture was a mixture containing a tetrafunctional urethane acrylate (hereinafter referred to as "A-2") having an Mw of 10,000 as determined by GPC, and 30% of M-111.

[0104] 4) Manufacturing Example 4 (Production of polyester-based bifunctional urethane acrylate) A 1 L flask equipped with a stirrer, a thermometer, and 5% ON piping was charged with 59.99 g of IPDI, 0.26 g of BHT, and 220.41 g of M-111 used as a diluent. The contents were stirred while blowing in 5% ON, and the temperature inside the flask was raised to 70°C. 0.005 g of Narcem was added, followed by the gradual addition of the same polyester diol with a hydroxyl value of 55 mgKOH / g as used in Production Example 2. A final total of 440.51 g of polyester was charged. 2.43 g of 1,4-butanediol was then added, and the temperature inside the flask was raised to 80°C. When the molecular weight of the contents measured by GPC exceeded 32,000, 11.36 g of 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") was added. At this time, 0.005 g of Nursem was also added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was then terminated. The resulting reaction mixture was a mixture containing a bifunctional urethane acrylate (hereinafter referred to as "A'-1") having a Mw of 41,000 as determined by GPC, and 30% of M-111.

[0105] 5) Manufacturing Example 5 (Production of polyester-based bifunctional urethane acrylate) A 1 L flask equipped with a stirrer, a thermometer, and 5% ON piping was charged with 59.99 g of IPDI, 0.26 g of BHT, and 220.41 g of M-111 used as a diluent. The contents were stirred while blowing in 5% ON, and the temperature inside the flask was raised to 70°C. 0.005 g of Narcem was added, and then the same polyester diol with a hydroxyl value of 55 mgKOH / g as used in Production Example 2 was gradually added. Finally, 440.51 g of polyester diol was charged. Thereafter, the temperature inside the flask was raised to 80°C. When the molecular weight of the contents measured by GPC exceeded 8,000, 11.36 g of HEA was added. At this time, 0.005 g of Nursem was also added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was then terminated. The resulting reaction mixture was a mixture containing a bifunctional urethane acrylate (hereinafter referred to as "A'-2") having an Mw of 9,000 as determined by GPC, and 30% of M-111.

[0106] 2. Examples and Comparative Examples 1) Production of active energy ray-curable composition The compounds shown in Table 1 below were mixed by stirring in the ratios shown in Table 1 to prepare active energy ray-curable compositions. The resulting compositions were evaluated as described below, and the results are shown in Table 2.

[0107] [Table 1]

[0108] The numbers in Table 1 indicate the number of copies. Abbreviations other than those defined above have the following meanings. M-113: Nonylphenol EO-modified (n=4) acrylate, "Aronix M-113" manufactured by Toagosei M-313: Isocyanuric acid ethylene oxide modified di- and triacrylate, Toagosei "Aronix M-313" HCPK: 1-hydroxycyclohexyl phenyl ketone, Omnirad 184 manufactured by IGM Resins

[0109] 2) Composition evaluation method (1) Viscosity The viscosity of the compositions obtained in Table 1 was measured at 25° C. using an E-type viscometer. The results are shown in Table 2.

[0110] 3) Evaluation method for cured film ◆Adhesive sheet manufacturing The composition obtained in Table 1 was applied with an applicator to a polyethylene terephthalate film (Lumirror T60 (thickness: 50 μm), manufactured by Toray Industries, Inc., 300 mm wide x 300 mm long) to form a coating film with a thickness of 20 μm. Hereinafter, this film will be referred to as "PET." Next, a release PET film (Cerapeel BKE (thickness 38 μm), manufactured by Toray Advanced Film Co., Ltd., 300 mm wide x 300 mm long, hereinafter referred to as "release PET") was laminated onto the film. Then, the film was placed in a conveyor-type ultraviolet irradiation device manufactured by Eye Graphics Co., Ltd. (160W / cm high-pressure mercury lamp, lamp height 25cm, UV-A region irradiation intensity 200mW / cm 2 (Measurement value of UV POWER PUCK manufactured by Heraeus) and irradiated with UV-A energy of 200mJ / cm from the release PET side. 2 The adhesive sheet was obtained by irradiating the adhesive sheet with ultraviolet light. The release PET was peeled off from the obtained pressure-sensitive adhesive sheet, and the evaluations described below were carried out.

[0111] (2) Acryloyl group reaction rate The acryloyl group reaction rate of the cured film was measured by infrared absorption spectroscopy (μ-ATR method) using a Spectrum 100 manufactured by PerkinElmer Japan Co., Ltd. Using the obtained ultraviolet absorption spectrum, the reaction rate of the acryloyl group was calculated according to the following formula (1). Acryloyl group reaction rate = {1 - (B2 / A2) / (B1 / A1)] × 100 (1) A1: 1724 cm originating from -C=O of the composition -1 Peak height of B1: 1405 cm originating from -CH=CH2 of the composition -1 Peak height of A2: 1724 cm originating from -C=O of the cured film -1 Peak height of B2: 1405 cm originating from -CH=CH2 of the cured film -1 Peak height of The closer this value is to 100%, the more the unsaturated double bonds that contribute to the polymerization reaction have disappeared, and the more sufficiently the composition has curability.

[0112] (3) Peel strength The adhesive strength of the obtained pressure-sensitive adhesive sheet was measured in accordance with JIS Z 0237:2009. Specifically, coated white cardboard (Maricoat, manufactured by Hokuetsu Kishu Paper Co., Ltd.; hereinafter referred to as "cardboard") was used as the adherend, and the 180° peel strength (peel speed: 300 mm / min) was measured under conditions of 23°C and 50% RH. The peel strength was measured using a universal material testing machine, Instron 5564, manufactured by Instron Japan Company Limited.

[0113] (4)Removability The surface condition of the cardboard after peeling off the PET under the same conditions as in the peel strength measurement in (3) above was visually observed and evaluated according to the following two criteria. Good: No glue residue is visible on the surface of the cardboard. ×: Glue residue is observed on the surface of the cardboard.

[0114] [Table 2]

[0115] As is clear from the results of Examples 1 and 2, the composition of the present invention has excellent curing properties, and when used as an adhesive, it has high cohesive strength, resulting in high peel strength, and also has excellent removability, resulting from little adhesive residue. In contrast, the compositions of Comparative Examples 1 and 2, which do not contain component (A), have low curing properties, and the residual unreacted monomer reduces the cohesive strength, causing adhesive residue, and the peel strength and removability are both insufficient. [Industrial Applicability]

[0116] The composition of the present invention relates to a curable composition, and can be preferably used in particular as an active energy ray-curable composition. Furthermore, specific applications of the composition of the present invention include various curable compositions such as pressure-sensitive adhesives, adhesives, and sealants.

Claims

1. A curable composition comprising the following component (A) and component (B), wherein the content of component (A) is 10 to 50 wt % relative to 100 wt % of the total amount of component (A) and component (B): Component (A): a reaction product of mixture (a1) which is a mixture of a polyol, an organic polyisocyanate, and at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, and has a hydroxyl value of 20 to 300 mg KOH / g Component (B): a compound having an ethylenically unsaturated group other than component (A).

2. 2. The curable composition according to claim 1, wherein the organic polyisocyanate is an aliphatic polyisocyanate or an alicyclic polyisocyanate.

3. The component (A) is a prepolymer having an isocyanate group produced by reacting a polyol and an organic polyisocyanate; a reaction product with a mixture (a1) of at least one compound selected from the group consisting of glycerin (meth)acrylate and diglycerin (meth)acrylate, the mixture having a hydroxyl value of 20 to 300 mg KOH / g; The curable composition according to claim 1 or 2, wherein

4. The curable composition according to any one of claims 1 to 3, wherein the weight average molecular weight of component (A) is 3,000 to 200,000.

5. An active energy ray-curable composition comprising the composition according to any one of claims 1 to 4.

6. 6. The active energy ray-curable composition according to claim 5, further comprising 0.1 to 10 parts by weight of a photopolymerization initiator, relative to 100 parts by weight of the total amount of the component (A), or relative to 100 parts by weight of the total amount of the component (A) and the component (B).

7. An active energy ray-curable coating composition comprising the composition according to claim 5 or 6.

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