JP2015229702A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition capable of forming a cured product excellent in excoriation resistance, molding processability and oil resistant cosmetic property.SOLUTION: There is provided a curable composition containing (A) urethane (meth)acrylate having a number average molecular weight of 5000 to 30000 obtained by reacting (a), (b) and (c) and having no yield point in a tensile stress-strain curve figure measuring a cured article thereof at 23°C and fracture point elongation of 200% or more, and (B) block aliphatic isocyanate with a weight ratio of the (A) urethane (meth)acrylate and the (B) block aliphatic isocyanate of 95:5 to 70:30. (a) chain aliphatic polycarbonate diol having a number average molecular weight of 300 to 900. (b) (meth)acrylic acid ester having a hydroxyl group and a (meth)acryloyl oxy group in an alicyclic diisocyanate (c) molecule.

Description

  The present invention contains a urethane (meth) acrylate and a blocked aliphatic isocyanate, and is a primary cured product having a particularly high moldability, and a secondary curing excellent in resistance to scratches and oily cosmetics such as sun oil. The present invention relates to a curable composition useful as a protective film on the surface of a resin thin film such as a resin film or a resin sheet, which can form a product. The primary cured product of the curable composition of the present invention is an intermediate cured product / intermediate cured product in which urethane (meth) acrylate in the curable composition is radically polymerized and crosslinked by irradiation with active energy rays such as ultraviolet rays and electron beams. The term “secondary cured product” means a coating, and the primary cured product is further formed by heating the primary cured product and forming an allophanate group by an addition reaction between the urethane group in the primary cured product and an isocyanate group that has been unblocked by heating. This means a final cured product / final cured film that has been crosslinked and cured.

  Conventionally, in order to protect the base material of a molded product and maintain aesthetics, the base material is coated with a coating agent, and various materials are used for the coating agent. Among them, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, etc., which have the property of being cured by active energy rays such as ultraviolet rays and electron beams, have been used as coating agents. It is known that (meth) acrylate forms an excellent cured film that is tough, has high mechanical strength, and is resistant to chemicals. Therefore, urethane (meth) acrylate is used in various fields as a main component of various types of coating agents that are cured with active energy rays.

  In recent years, carbonate polyol has attracted attention as a polyol compound that is a material of this urethane (meth) acrylate. This is because urethane (meth) acrylates obtained using carbonate polyol are mechanical properties, hydrolysis resistance, heat resistance, chemical resistance, weather resistance compared to those using polyether polyol or polyester polyol. This is because an excellent cured product can be obtained.

  Examples of such urethane (meth) acrylates using carbonate polyols as raw materials include polycarbonate diols using 1,5-pentanediol and 1,6-hexanediol as raw materials, organic isocyanates, and hydroxy unsaturated compounds. The urethane (meth) acrylate used is disclosed (see Patent Document 1), and the cured product of the urethane (meth) acrylate is characterized by high elongation and high strength. Further, a urethane (meth) acrylate comprising a polycarbonate diol having a number average molecular weight of 250 to 850, a diisocyanate compound, and a hydroxyl group-containing (meth) acrylic acid ester is disclosed (see Patent Document 2). A (meth) acrylate provides a cured product that exhibits silver protection performance when mixed with a (meth) acrylic ester. In addition, as a material of a curable composition having excellent physical property balance such as oil resistance, sweat resistance, hydrolysis resistance, weather resistance, flexibility, and adhesion, it is derived from an alcohol containing 2-methyl-1,3-propanediol. A urethane (meth) acrylate comprising a polycarbonate diol, a hydroxyl group-containing (meth) acrylate, and an isocyanate compound is disclosed (see Patent Document 3). Also disclosed is a urethane acrylate comprising a polycarbonate polyol having an alicyclic structure, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate as a material for a curable composition having excellent chemical resistance and flexibility. (See Patent Document 4). Furthermore, a urethane acrylate capable of forming a cured product excellent in scratch resistance and molding processability comprising a polycarbonate diol having a number average molecular weight of 300 to 1200, an alicyclic diisocyanate, and a hydroxyl group-containing (meth) acrylic ester. It is disclosed (see Patent Document 5).

JP-A-6-166737 JP 2005-171154 A JP 2008-37989 A JP 2009-227915 A JP 2012-36290 A

  When a protective (cured) film is formed using a composition containing urethane (meth) acrylate, a method of performing a curing treatment after directly applying a liquid composition to the substrate surface, and applying the composition to a film or sheet There is a method in which a protective film is formed by a curing treatment and a simultaneous molding decoration method such as film insert molding or vacuum molding using the film or sheet. In the former case, the elongation of the cured product hardly poses a problem, but in the latter case, in addition to the high scratch resistance to prevent the cured product from being scratched, the cured product is molded metal. Since it deforms according to the shape of the mold, the cured product is required to have a large elongation. However, the urethane (meth) acrylate described in Patent Documents 1 to 4 is premised on the use of the former method, and since the large elongation required for molding processing is not required, the urethane (meth) acrylate is used. From the curable composition to be contained, it is not possible to obtain a cured product having excellent scratch resistance and having a large elongation necessary for molding. Since the urethane (meth) acrylate described in Patent Document 5 is premised on use in the latter method, a cured product having excellent scratch resistance and large elongation necessary for molding can be obtained. It has a problem that it is inferior in resistance to oily cosmetics such as sun oil required when applied to indoor mounting parts.

  Therefore, the present invention is a primary cured product having excellent elongation that can be applied to molding simultaneous decoration methods such as film insert molding and vacuum molding, and secondary curing excellent in resistance to scratches and oily cosmetics such as sun oil. It is an object of the present invention to provide a curable composition capable of forming a product.

  In order to solve the above problems, the present invention has the following configuration. The curable composition of the present invention comprises (a) a chain aliphatic polycarbonate diol having a number average molecular weight of 300 to 900, (b) an alicyclic diisocyanate, and (c) one hydroxy group and one in the molecule. Tensile stress-strain of the cured product measured at 23 ° C. with urethane (meth) acrylate having a number average molecular weight of 5000 to 30000 obtained by reacting (meth) acrylic acid ester having (meth) acryloyloxy group of In the curve diagram, (A) urethane (meth) acrylate having no yield point and having an elongation at break of 200% or more and (B) blocked aliphatic isocyanate, and (A) urethane (meta The weight ratio of acrylate) to blocked aliphatic isocyanate (B) is 95: 5 to 70:30.

  The curable composition containing the urethane (meth) acrylate and the blocked aliphatic isocyanate of the present invention is a radical polymerization, cross-linking in a form in which the urethane (meth) acrylate includes the blocked aliphatic isocyanate by irradiation with active energy rays. Cured to obtain a primary cured product. The primary cured product can maintain its cross-linked structure even at a high temperature of 150 ° C., for example. In the tensile stress-strain curve diagram measured at 23 ° C., the primary cured product does not have a yield point and has an elongation at break. Since it is 200% or more, it is suitable for molding processes involving heating such as film insert molding and vacuum molding.

  Moreover, the blocking agent of the blocked aliphatic isocyanate is liberated by heating the primary cured product, and the deblocked aliphatic isocyanate reacts with the urethane bond in the skeleton molecule of urethane (meth) acrylate, and allophanate. By forming a bond, a secondary cured product can be obtained by further crosslinking the skeleton molecules of urethane (meth) acrylate. By this crosslinking with an aliphatic isocyanate, the resistance to oily cosmetics that cannot be obtained with a cured product of urethane (meth) acrylate alone is greatly improved.

  Since the secondary cured product of the curable composition of the present invention does not have a yield point, when the applied stress is within the elastic limit, it is restored to its original shape when released from the stress, and deformation does not occur. This means that when an external force that causes scratches is applied to the surface of the cured product, the external force is absorbed when the cured product dents (extends), and when the external force is removed, it returns to its original shape. This means that it does not remain and no flaws are formed. That is, it can be said that the allowable limit with respect to the external force of hardened | cured material is high, and it is excellent in abrasion resistance.

  Here, having no yield point is shown in FIG. 1, which is a tensile stress-strain curve diagram of Synthesis Example 1 described later, for example, in a tensile stress (MPa) -strain (%) curve diagram measured at 23 ° C. Thus, it shows a curve in which the tensile stress continues to increase as the strain increases, and the cured product undergoes elastic deformation until it breaks, so the shape returns to its original state when the load is unloaded. On the other hand, having a yield point means, for example, a curve having a portion where the tensile stress is reduced despite an increase in strain, as shown in FIG. 2 which is a tensile stress-strain curve diagram of Comparative Example 2 described later. Since the deformation is elastic up to the yield point, the shape will return to its original value when the load is unloaded, but after the yield point it is a plastic deformation, so if a load exceeding the yield point is applied, the load will be removed. Even if it loads, it does not return to the original shape completely.

  The blocked aliphatic isocyanate is preferably at least one of a blocked aliphatic isocyanate trimer and a blocked aliphatic isocyanate burette. The cured product of the curable composition can further improve oil resistance cosmetic properties.

  According to the curable composition of the present invention, a primary cured product excellent in molding processability, and a secondary cured product excellent in scratch resistance and oil resistance cosmetic properties can be obtained. Thereby, simultaneous decorating such as film insert molding using a film or sheet coated with a primary cured product, vacuum molding, or the like becomes possible. In addition, the primary cured product becomes a secondary cured product by heat at the time of molding, and the secondary cured product has high adhesion to the base material, and has properties such as chemical resistance and weather resistance, The substrate can be appropriately protected from the external environment.

5 is a tensile stress-strain curve diagram in Synthesis Example 1. FIG. 6 is a tensile stress-strain curve diagram in Comparative Synthesis Example 2. FIG. 2 is a tensile stress-strain curve diagram of the primary cured product after electron beam irradiation in Example 1. FIG. 2 is a tensile stress-strain curve diagram of the secondary cured product after electron beam irradiation and heating in Example 1. FIG.

  Hereinafter, the present invention will be described in detail. The curable composition of the present invention comprises (a) a chain aliphatic polycarbonate diol, (b) an alicyclic diisocyanate, (c) one hydroxy group and one (meth) acryloyloxy in the molecule. The main component is urethane (meth) acrylate (component A) obtained by reacting a (meth) acrylic acid ester having a group, and a blocked aliphatic isocyanate (component B) is added thereto.

  In this specification, the term “(meth) acrylate” is a general term for “acrylate” and “methacrylate”. Similarly, the term “(meth) acrylic acid” is a general term for “acrylic acid” and “methacrylic acid”, and the term “(meth) acryloyloxy group” is “acryloyloxy group” and “methacryloyloxy group”. Is a general term.

<(A) Chain aliphatic polycarbonate diol>
The component (a) is a chain aliphatic polycarbonate diol having two hydroxyl groups in the molecule. In this specification, “chain aliphatic” means “acyclic aliphatic”, that is, a ring structure. It means an aliphatic that does not have. The chain aliphatic polycarbonate diol can be obtained by an ester exchange reaction between an alkanediol compound and a carbonate. Specific examples of the alkanediol compound include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 1,9-nonane. Diol, 1,10-decanediol, 2-methyl-1,3-propanediol, 1,5-hexanediol, 2-methyl-1,8-octanediol, neopentyl glycol, 2-isopropyl-1,4-butane Diol, 2-ethyl-1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3-butanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, etc. And the like. These may be used alone or in combination of two or more. Among these alkanediol compounds, a chain aliphatic polycarbonate diol using an alkanediol having 4 to 6 carbon atoms is preferable because excellent characteristics of a carbonate group can be obtained. Further, a combination of a branched chain alkanediol and a linear alkanediol, specifically, a chain aliphatic polycarbonate diol using 3-methyl-1,5-pentanediol and 1,6-hexanediol in combination, or 2 -The chain aliphatic polycarbonate diol using methyl-1,3-propanediol and 1,4-butanediol in combination has a higher secondary cured product of the resulting curable composition containing urethane (meth) acrylate. It is particularly preferable because it has scratch resistance and oil-resistant cosmetic properties. Some polycarbonate diols have an aromatic ring in the molecule and others have an alicyclic structure, but urethane (meth) acrylates using this are stronger than those using chain aliphatic polycarbonate diols. In the tensile stress-strain curve diagram measured at 23 ° C., it is not preferable because it easily has a yield point.

  The number average molecular weight of the chain aliphatic polycarbonate diol of component (a) is in the range of 300-900. When a chain aliphatic polycarbonate diol having a number average molecular weight of less than 300 is used, the resulting cured product of the curable composition containing urethane (meth) acrylate has a high modulus and has a yield point in the tensile stress-strain curve diagram. It becomes easy. On the other hand, when a chain aliphatic polycarbonate diol having a number average molecular weight exceeding 900 is used, the cohesive force decreases due to a decrease in the urethane bond concentration (the hydrogen bond concentration associated therewith), and the curable composition becomes sticky. In addition, the degree of increase in the degree of crosslinking due to the allophanate bond formed by the reaction with the blocked aliphatic isocyanate is small, and the durability against oily cosmetics is not sufficiently improved. The particularly preferable range of the number average molecular weight of the chain aliphatic polycarbonate diol is 400 to 600, and the curable composition containing urethane (meth) acrylate using the chain aliphatic polycarbonate diol having the number average molecular weight in the range. The cured product is superior in scratch resistance. A urethane (meth) acrylate using an aliphatic polyether diol or an aliphatic polyester diol as a material instead of the chain aliphatic polycarbonate diol has a low cohesive force, and a cured product has a sticky feeling and is not practical.

<(B) Alicyclic diisocyanate>
Component (b) is an alicyclic diisocyanate, and a cured product of a curable composition containing urethane (meth) acrylate synthesized using the alicyclic diisocyanate is excellent in weather resistance and adhesion. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, 1,3-bisisocyanatomethylcyclohexane, 1,4-bisisocyanatomethylcyclohexane, norbornane diisocyanate, and the like. it can. These can be used individually by 1 type or in combination of 2 or more types. Diisocyanate compounds with good weather resistance include aliphatic isocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate. However, urethane (meth) acrylates using this as a material are not preferable because they give a sticky feeling to the cured product.

<(C) (Meth) acrylic acid ester having one hydroxy group and one (meth) acryloyloxy group in the molecule>
A component (c) is a component which provides radical reactivity by adding to the terminal of the urethane prepolymer obtained by making a component (a) and a component (b) react. The component (c) is not particularly limited as long as it is a hydroxy group-containing (meth) acrylic acid ester having one (meth) acryloyloxy group and one hydroxy group in the molecule. Specific examples of the component (c) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4- Hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, adduct of 2-hydroxyethyl (meth) acrylate and caprolactone, 4-hydroxybutyl (meth) acrylate and caprolactone Additives, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, tri B propylene glycol mono (meth) acrylate, tetrapropylene glycol mono (meth) acrylate. These can be used individually by 1 type or in combination of 2 or more types.

  A compound having two or more hydroxy groups in the molecule such as trimethylolpropane mono (meth) acrylate, or two or more (meth) acryloyloxy groups in the molecule such as pentaerythritol tri (meth) acrylate. The compound that has a cured product of urethane (meth) acrylate using the same has a yield point in the tensile stress-strain curve diagram measured at 23 ° C. or because the elongation at break is less than 200%. Similarly, the primary cured product of the curable composition using urethane (meth) acrylate also has a yield point in the tensile stress-strain curve diagram measured at 23 ° C., or the elongation at break is 200%. Since it becomes less than, it is not preferable.

<Urethane (meth) acrylate (component A)>
The urethane (meth) acrylate of the present invention is synthesized by reacting the above components (a), (b), and (c), and the synthesis method is not particularly limited, and various known synthesis methods. Is available. For example, the chain aliphatic polycarbonate diol of component (a) is dropped into a mixture of a cycloaliphatic diisocyanate of component (b) and a catalyst such as di-n-butyltin dilaurate at 50 to 80 ° C. To obtain a urethane prepolymer, and the component (c) hydroxyl group and (meth) acryloyloxy group-containing (meth) acrylic acid ester in the presence of a polymerization inhibitor such as hydroquinone monomethyl ether, 50 to It can manufacture by making it react at 80 degreeC. Alternatively, the component (b) and the component (c) may be reacted first, and then the component (a) may be reacted. Here, when the use ratio of the components (a), (b), and (c) is (a) / (b) / (c) = n / n + 1/2 (n is an integer of 2 or more) in terms of molar ratio, Since it can suppress that an unreacted surplus component arises and manufacturing cost can be reduced, it is preferable. Urethane (meth) acrylate is preferably reacted up to 98% or more at the end of the synthesis, and the reaction rate of the synthesis reaction can be calculated from various methods, for example, quantitative results of the amount of isocyanate according to JISK1556.

  The number average molecular weight of the synthesized urethane (meth) acrylate is in the range of 5000 to 30000. A cured product of urethane (meth) acrylate having a number average molecular weight of less than 5000 has a high modulus, has a yield point in the tensile stress-strain curve diagram, has an elongation at break of less than 200%, and has insufficient elongation. Therefore, a curable composition using this is not suitable as a main raw material of the curable composition of the present invention because of low scratch resistance and poor moldability. On the other hand, when the number average molecular weight exceeds 30000, the viscosity of urethane (meth) acrylate becomes remarkably high, which hinders the operation of applying a curable composition containing urethane (meth) acrylate to the substrate. Moreover, since the cured product is likely to be sticky, subsequent handling becomes difficult and it is not practically used.

  The urethane (meth) acrylate can be cured by irradiating energy rays such as ultraviolet rays or electron beams, and the cured product does not have a yield point in the tensile stress-strain curve diagram measured at 23 ° C. and breaks. The point elongation is 200% or more.

<Blocked aliphatic isocyanate (component B)>
The blocked aliphatic isocyanate of the present invention is an aliphatic isocyanate such as hexamethylene diisocyanate or trimethylhexamethylene diisocyanate, or isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, 1,3-bisisocyanatomethylcyclohexane, 1 , 4-bisisocyanatomethylcyclohexane, norbornane isocyanate such as norbornane diisocyanate, a trimer or a buret of isocyanate group blocked with a blocking agent such as dimethylpyrazole, diethylmalate, methylethylketoxime or ε-caprolactam And the oil-resistant cosmetic properties of the secondary cured product of the curable composition can be improved. Among these, a trimer of aliphatic isocyanate such as hexamethylene diisocyanate or a blocked aliphatic isocyanate of burette is not yellowed by heating to obtain a secondary cured product, and three isocyanate groups in one molecule. Is a structure attached to the end of an aliphatic hydrocarbon chain, which is excellent in reactivity, can further improve oil-resistant cosmetic properties, and has a flexible cross-linked structure, so that the tensile stress measured at 23 ° C.− This is preferable because it is difficult to have a yield point in the strain curve diagram, and as a result, the scratch resistance is not impaired.

  The blocking agent can be appropriately selected from dimethylpyrazole, diethyl malonate, methyl ethyl ketoxime, ε-caprolactam, etc. depending on the heating conditions for dissociating the blocking agent, but the blocking agent at a relatively low temperature. When it is necessary to dissociate dimethylpyrazole, it is preferable.

<Curable composition>
The curable composition of the present invention is constituted by mixing the urethane (meth) acrylate of component A and the blocked aliphatic isocyanate of component B in a ratio of 95: 5 to 70:30 by weight ratio. Yes.

  First, the curable composition of the present invention is cured by radical polymerization of urethane (meth) acrylate in a form including blocked aliphatic isocyanate by irradiating energy rays such as ultraviolet rays or electron beams. A primary cured product is obtained. Since the primary cured product contains an appropriate amount of blocked aliphatic isocyanate, the properties of the cured product of urethane (meth) acrylate alone are maintained without being impaired, and the primary cured product obtained by irradiation with energy rays. In the tensile stress-strain curve diagram measured at 23 ° C., there is no yield point and the elongation at break is 200% or more. That is, FIG. 3, which is a tensile stress-strain curve diagram measured at 23 ° C. in Example 1 described later, shows that it does not have a yield point and the elongation at break is 200% or more. Can understand. Therefore, the primary cured product cured by irradiation with energy rays can be applied to simultaneous molding decoration methods such as film insert molding and vacuum molding, and the blocking agent of blocked aliphatic isocyanate is released by heating at that time. The deblocked aliphatic isocyanate reacts with a urethane group in the skeleton molecule of urethane (meth) acrylate to form an allophanate group, whereby a further crosslinked secondary cured product is obtained. By this crosslinking with an aliphatic isocyanate, the resistance to oily cosmetics that cannot be obtained by curing urethane (meth) acrylate alone is greatly improved. Furthermore, since the composition of the present invention is set to a predetermined amount of the blocked aliphatic isocyanate, the crosslinking does not proceed excessively, and the secondary cured product obtained by heating the primary cured product. Also in the tensile stress-strain curve diagram measured at 23 ° C. (FIG. 4 which is a tensile stress-strain curve diagram measured at 23 ° C. in Example 1 described later), it has no yield point, and thus has excellent scratch resistance. It can be understood that physical properties are exhibited. When the ratio of the blocked aliphatic isocyanate is smaller than the above range, the resistance of the secondary cured product of the curable composition to the oily cosmetic product is not improved. On the other hand, if the ratio of the blocked aliphatic isocyanate is larger than the above range, the properties of the urethane (meth) acrylate are impaired, and the scratch resistance of the secondary cured product of the curable composition is deteriorated. .

  The energy beam source for curing the curable composition of the present invention is not particularly limited. Examples include UV lamps, electron beam accelerators, γ-ray irradiation devices, high pressure mercury lamps, metal halide lamps, xenon lamps, and carbon arc lamps. Is mentioned. In the case of curing using any energy beam source, it is preferable to replace the air with an inert gas in an energy beam irradiation atmosphere to such an extent that inhibition of curing by oxygen in the air can be prevented.

  In the curable composition of the present invention, an allophanatization catalyst can be used for the purpose of promoting the reaction between an isocyanate group and a urethane group. Examples of the allophanatization catalyst include organic zinc compounds such as bis (2,4-pentanedionato) zinc (II) and bis (2-ethylhexanoyloxy) zinc, N, N, N-trimethyl-N-2-hydroxy Tetraalkylammonium compounds such as propylammonium hydroxide, N, N, N-trimethyl-N-2-hydroxypropylammonium 2-ethylhexanoate, and organotin compounds such as di-n-butyltin dilaurate are effective. . The addition amount of the allophanatization catalyst is preferably 0.05 to 2.0% by weight with respect to the total weight of the urethane (meth) acrylate and the blocked isocyanate.

  The curable composition of the present invention preferably contains a silicon-based surface conditioner such as a silicon-based slip agent having a polymerizable unsaturated group and the leveling agent. In the case of using the silicon-based surface conditioner having a polymerizable unsaturated group, it is oriented and crosslinked in the surface layer at the time of curing, and the slip property can be maintained over a long period of time and the scratch resistance can be improved. The preferable compounding amount is 0.1 to 5% by weight. This silicone-based surface conditioner having a polymerizable unsaturated group can be obtained by condensation reaction of both terminal carbinol-modified siloxane, one terminal diol siloxane, one terminal monool siloxane and (meth) acrylic acid, or polyisocyanate and hydroxyl. It can be obtained by an addition reaction using a group-containing (meth) acrylic acid ester. Specific examples thereof include, for example, X-22-164B (manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-174DX (manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-UV 3500 (manufactured by Big Chemie Japan), BYK-UV 3570 (Bic Chemie (Manufactured by Japan). These can be used individually by 1 type or in combination of 2 or more types.

  In the curable composition of the present invention, other polymerization curable compounds can be blended within a range that does not impair the characteristics of the present invention. Specific examples thereof include polybasic acids such as phthalic acid and succinic acid, polyester poly (meth) obtained by reaction with polyhydric alcohols such as ethylene glycol, hexanediol and polyethylene glycol, and (meth) acrylic acid or derivatives thereof. Epoxy (meth) in which (meth) acrylic acid or a derivative thereof is reacted with bisphenol-type epoxy resin obtained by condensation reaction of acrylate, bisphenols such as bisphenol A, bisphenol F, bisphenol S, tetrabromobisphenol A and epichlorohydrin An organic diisocyanate compound was added to the hydroxyl group of an alcohol composed of one or a mixture of two or more of acrylate and alkanediol, polyetherdiol, polyesterdiol, spiroglycol compound, etc. A urethane (meth) acrylate other than the above obtained by reacting a socyanate group with one or more (meth) acryloyloxy groups in the molecule and a hydroxy group-containing (meth) acrylic acid ester having one hydroxy group, and hexane Diol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Such as (meth) acrylic acid ester, tetraethylene glycol di (meth) acrylic acid ester, tripropylene glycol di (meth) acrylic acid ester, polybutylene glycol di (meth) acrylic acid ester, etc. Alkylene glycol (meth) acrylic acid ester, hydroxypivalate neopentyl glycol di (meth) acrylic acid ester, tris (2-acryloyloxyethyl) isocyanurate, ditrimethylolpropane tetra (meth) acrylic acid ester, dipentaerythritol penta Polyfunctional (meth) acrylic acid ester, such as (meth) acrylic acid ester and dipentaerythritol hexa (meth) acrylic acid ester, is mentioned. These can be used alone or in combination of two or more.

  The curable composition of this invention may contain an organic solvent as needed. Examples of the organic solvent include ester solvents such as butyl acetate and ethyl acetate, ketone solvents such as methyl ethyl ketone and acetone, and aromatic organic solvents such as toluene and xylene. These organic solvents can be used alone or in combination of two or more.

  If necessary, a photopolymerization initiator can be added to the curable composition of the present invention. The type of the photopolymerization initiator is not particularly limited, and known ones can be used. Typical examples include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, Methyl orthobenzoyl benzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2-ethylanthraquinone, 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, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2- Methylamino-1- (4-morpholinophenyl) -butanone-1, diethylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4- Examples include trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and methylbenzoylformate. These may be used alone or in combination. Moreover, 0.1-10 weight% is preferable with respect to the sum total of a curable composition, and, as for the addition amount in the case of using a photoinitiator, 1-5 weight% is more preferable.

  If necessary, the curable composition of the present invention is within a range that does not impair its performance, for example, a thermal polymerization initiator, a thermoplastic polymer, a slip agent, a leveling agent, an antifoaming agent, an antioxidant, Light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, inorganic fillers, organic fillers, colorants, flame retardants, antistatic agents, surface-organic-treated inorganic fillers, and other known additives May be used.

  Since the curable composition of the present invention is excellent in scratch resistance and can form a cured product having properties such as chemical resistance and weather resistance, it can be suitably used as a film for protecting various articles. it can. In addition, the primary cured product by irradiation with energy rays is excellent in molding processability and has high adhesion to the base material, so it is suitable for sheet-like materials used for film insert molding and vacuum molding. It is useful as a protective coating for members molded with resin such as panels. In addition, the curable composition of the present invention can be formed not only by molding after forming a primary cured product by irradiation with energy rays, but can also form a film by curing after applying the composition on a substrate. .

Hereinafter, the present invention will be described in detail with reference to synthesis examples and examples. The abbreviations in Synthesis Examples and Examples are as follows.
PCD350: polycarbonate diol obtained from 1,6-hexanediol as a raw material (OH value 320.6 number average molecular weight 350)
PCD420: polycarbonate diol obtained using 3-methyl-1,5-pentanediol and 1,6-hexanediol as raw materials (OH value 267.1 number average molecular weight 420)
PCD500: polycarbonate diol obtained using 3-methyl-1,5-pentanediol and 1,6-hexanediol as raw materials (OH value 224.4 number average molecular weight 500)
PCD520: polycarbonate diol obtained by using 3-methyl-1,5-pentanediol and 1,6-hexanediol as raw materials (OH value 215.8 number average molecular weight 520)
PCD570: Polycarbonate diol obtained by using 2-methyl-1,3-propanediol and 1,4-butanediol as raw materials (OH number 196.8 number average molecular weight 570)
PCD800: polycarbonate diol obtained from 1,5-pentanediol and 1,6-hexanediol as raw materials (OH number 140.3 number average molecular weight 800)
PCD1000: polycarbonate diol obtained using 1,6-hexanediol as a raw material (OH value 112.2 number average molecular weight 1000)
PTMG650: polytetramethylene diol (OH number 172.6 number average molecular weight 650)
PCL500: polycaprolactone diol (OH value 224.4 number average molecular weight 500)
IPDI: isophorone diisocyanate NBDI: norbornane diisocyanate HMDI: bis (4-isocyanatocyclohexyl) methane HXDI: 1,3-bis (isocyanatomethyl) cyclohexane XDI: xylylene diisocyanate TMHDI: trimethylhexamethylene diisocyanate 2-HEA: 2-hydroxy Ethyl acrylate 2-HPA: 2-hydroxypropyl acrylate 4-HBA: 4-hydroxybutyl acrylate FA1: 6-hydroxyhexanoic acid 2-[(1-oxo-2-propenyl) oxy] ethyl DEGA: diethylene glycol monoacrylate TPGA: Tripro Rylene glycol monoacrylate PETA: pentaerythritol triacrylate DBTDL: di-n-butyltin dilaurate M EHQ: Hydroquinone monomethyl ether MEK: Methyl ethyl ketone BI1: Dimethylpyrazole blocked hexamethylene diisocyanate trimer BI2: Dimethylpyrazole blocked hexamethylene diisocyanate buret BI3: Dimethylpyrazole blocked isophorone diisocyanate BI4: Dimethylpyrazole blocked isophorone diisocyanate Trimer CAT1: di-n-butyltin dilaurate CAT2: bis (2,4-pentanedionato) zinc (II)

[Synthesis Example 1]
In a 2 L four-necked flask, 192.3 g of isophorone diisocyanate (IPDI), 199.9 g of methyl ethyl ketone (MEK), 0.30 g of di-n-butyltin dilaurate (DBTDL) and 0.30 g of hydroquinone monomethyl ether (MEHQ) were added. While stirring and stirring, the flask was heated to 60 ° C. with a water bath. To this, 385.0 g of polycarbonate diol PCD500 (OH number 224.4, number average molecular weight 500) and 199.9 g of methyl ethyl ketone (MEK) were charged into a dropping funnel and mixed uniformly, while maintaining the flask internal temperature at 60 ° C. The solution was dropped at a constant rate for 3 hours and stirred at the same temperature for 1 hour to react. Subsequently, 22.3 g of 2-hydroxyethyl acrylate (2-HEA) charged in another dropping funnel was dropped at a constant rate for 1 hour while maintaining the flask internal temperature at 60 ° C., and then the temperature of the flask contents was set to 70 ° C. The mixture was stirred for 2 hours until the reaction rate reached 99% or more to synthesize urethane acrylate UA1 (containing 40% methyl ethyl ketone). The end point of the reaction was determined by the isocyanate concentration. Specifically, the reaction was terminated when the reaction rate calculated based on the amount of isocyanate determined according to JISK1556 reached 99% or more.

  Urethane acrylate UA1 was measured and evaluated according to the following measurement method and evaluation method 1. The results are shown in Table 1 below. Moreover, the tensile stress-strain curve of the urethane acrylate UA1 of Synthesis Example 1 prepared according to the following film characteristic value test is shown in FIG. From the result of FIG. 1, it can be seen that the cured product of urethane acrylate UA1 has no yield point in the tensile stress-strain curve and has an elongation at break of 200% or more.

[Measurement method and evaluation method 1]
<Number average molecular weight>
The number average molecular weight of the raw material (a) component is a value calculated from the OH value, and the number average molecular weight of urethane (meth) acrylate is measured using gel permeation chromatography (HLC-8120GPC manufactured by Tosoh Corporation), and the measurement result Is a value in terms of polystyrene.

<The film characteristic value of urethane (meth) acrylate>
Urethane (meth) acrylate was applied to glass so that the dry film thickness was 100 μm, heated at 60 ° C. for 30 minutes to volatilize the solvent, and then in a nitrogen atmosphere, an electron beam accelerator (Electro by Iwasaki Electric Co., Ltd.) Curtain EC250 / 15 / 180L) An evaluation film was prepared by irradiating and curing a 5 Mrad electron beam at 175 Kv.

  The surface state was evaluated by visual inspection and finger touch on the surface of the evaluation film formed on the glass. If no abnormality was found, the state was described if there was a problem such as ○ or tack.

  This evaluation film was peeled from glass and cut into a strip shape having a width of 25 mm and a length of 90 mm as a sample, and it was 23 ° C. with a universal material testing machine (Shimadzu Corporation Autograph AG-IS) at a tensile speed of 50 mm / A tensile stress-strain curve was created from the results obtained by applying a load in minutes. In the tensile stress-strain curve, the one having no yield point was marked with ◯, the one with the yield point was marked with ×, and the elongation of the sample at the time when the sample broke was defined as the elongation at break.

[Synthesis Examples 2 to 10, Comparative Synthesis Examples 1 to 8]
The urethane acrylates UA2 to 10 and HUA1 to 8 were synthesized in the same manner as in Synthesis Example 1 except that the synthetic materials described in Table 1 below were used, and the urethane acrylates UA2 to 10 and HUA1 to 8 were measured using the above measuring method and evaluation. Measurement and evaluation were performed according to Method 1. The results are shown in Table 1 below. In addition, FIG. 2 shows a tensile stress-strain curve of urethane acrylate HUA1 of Comparative Synthesis Example 1 created according to the film characteristic value test. From the result of FIG. 2, the cured product of urethane acrylate HUA1 according to Comparative Synthesis Example 1 has a clear yield point in the tensile stress-strain curve.

[Example 1]
89 g of urethane acrylate (UA1) (weight excluding the solvent), 11 g of hexamethylene diisocyanate trimer (BI1) blocked with dimethylpyrazole (weight excluding the solvent), and dilauric acid di-n-n as the allophanatization catalyst A curable composition was prepared by mixing 0.5 g of butyltin (CAT1). The obtained curable composition was measured and evaluated for primary cured product and secondary cured product characteristic values according to the following measurement method and evaluation method 2. The results are shown in Table 2 below. Further, FIG. 3 shows the tensile stress-strain curve of the primary cured product, and FIG. 4 shows the tensile stress-strain curve of the secondary cured product. As shown in FIG. 3, the primary cured product showed an elongation of 200% or more and had no yield point, like the cured product of urethane acrylate UA1 shown in FIG. Further, as shown in FIG. 4, the secondary cured product has the urethane acrylate UA1 shown in FIG. 1 although the elongation is reduced due to the formation of allophanate groups due to the reaction of isocyanate and urethane groups to form new crosslinks. Like the cured product, it did not have a yield point.

[Measurement method and evaluation method 2]
[Primary cured product characteristic value]
The curable composition was applied to glass so that the dry film thickness became 100 μm, heated at 60 ° C. for 30 minutes to volatilize the solvent, and then in a nitrogen atmosphere, an electron beam accelerator (Electro curtain EC250 / manufactured by Iwasaki Electric Co., Ltd.) (15 / 180L) A 5 Mrad electron beam was irradiated and cured at 175 Kv to prepare a primary cured product characteristic value evaluation sample.

<Surface condition>
The surface of the primary cured product characteristic value evaluation sample formed on the glass was evaluated by visual observation and finger touch. If there was no abnormality, it was rated as ○, and if there was a tack, it was marked as ×.

<Yield point and moldability>
The primary cured product characteristic value evaluation sample was peeled from the glass and cut into a strip shape having a width of 25 mm and a length of 90 mm as a sample, and 23 ° C. using a universal material testing machine (Autograph AG-IS manufactured by Shimadzu Corporation) A tensile stress-strain curve was created from the results obtained by applying a load at a tensile speed of 50 mm / min.
Yield point: In the tensile stress-strain curve, those having no yield point were marked with ◯, and those having a yield point were marked with x.
Molding workability: In the tensile stress-strain curve, those having an elongation at break of 200% or more were evaluated as ○, and those less than 200% were evaluated as ×.

[Secondary cured product characteristic value]
After the curable composition was applied to an acrylic resin film (film thickness 75 μm) having a 1 μm acrylic urethane primer layer so that the dry film thickness was 10 μm, the solvent was volatilized by heating at 60 ° C. for 30 minutes, In a nitrogen atmosphere, after irradiating a 5 Mrad electron beam at 175 Kv with an electron beam accelerator (electrocurtain EC250 / 15/180 L) manufactured by Iwasaki Electric Co., Ltd., this sample was heat-treated at 150 ° C. for 5 minutes to evaluate a secondary cured product property value Was made.

<Surface condition>
The surface state of the secondary cured product characteristic value evaluation sample was evaluated by visual observation and finger touch. If there was no abnormality, it was rated as ○, and if there was a tack, it was marked as ×.

<Adhesion>
Using the secondary cured product characteristic value evaluation sample, it was evaluated by a 1 mm square grid cellophane tape peeling test in accordance with JIS K5400. The case where there was no cell peeling was marked with ◯, and the case where even one cell was peeled off was marked with ×.

<Yield point>
The curable composition was applied to glass so that the dry film thickness became 100 μm, heated at 60 ° C. for 30 minutes to volatilize the solvent, and then in a nitrogen atmosphere, an electron beam accelerator (Electro curtain EC250 / manufactured by Iwasaki Electric Co., Ltd.) (15/180 L) After irradiating and curing a 5 Mrad electron beam at 175 Kv, heat treatment was performed at 150 ° C. for 5 minutes to prepare a secondary cured product. This secondary cured product was peeled off from glass and cut into a strip shape having a width of 25 mm and a length of 90 mm as a sample, and a universal material testing machine (Autograph AG-IS manufactured by Shimadzu Corporation) at 23 ° C. and a tensile speed. A tensile stress-strain curve of the secondary cured product was created from the result obtained by applying a load at 50 mm / min. In the tensile stress-strain curve, those having no yield point were marked with ◯, and those having a yield point were marked with ×.

<Abrasion resistance>
The surface of the secondary cured product characteristic value evaluation sample is a steel wool # 0000 with a diameter of 45 mm and a cylinder weight of 1 kg of its own weight. , Observed after 30 minutes, ◯ indicates that no scratches are observed, Δ indicates that there are no more than 10 scratches, and X indicates that many scratches are observed.

<Chemical resistance>
After applying ethanol to the surface of the secondary cured product characteristic value evaluation sample and holding it at room temperature for 1 hour, the chemical was wiped off with absorbent cotton and visually observed. If there was no change on the surface, it was rated as ◯.

<Oil-resistant cosmetic properties>
Characteristic value evaluation of secondary cured product Apply several drops of Nivea (registered trademark) (Nivea SUN face moist smooth milk) and Copatone (registered trademark) (copatone perfect UV cut milk A) on the surface of the sample, and hold at 80 ° C for 1 hour Then, the chemicals were wiped off with absorbent cotton soaked with ethanol and visually observed. If the surface did not change, 5 was evaluated, and the one with severe trace was 1, and the evaluation was performed in five stages of 1 to 5 according to the surface state. In addition, it means that oil resistance cosmetics property is so high that a numerical value is large.

<Weather resistance>
The weather resistance was evaluated using a metal halide lamp type eye super UV tester (SUV-W131 manufactured by Iwasaki Electric Co., Ltd.) using the secondary cured product characteristic value evaluation sample. As a result, when there was no change in 100 hours, the case where there was a change such as ◯, discoloration, cracking, glossiness, etc. was marked with ×.

[Examples 2 to 15]
A curable composition was prepared in the same manner as in Example 1 except that the materials and blending amounts shown in Table 2 were used, and the obtained curable composition was measured and evaluated according to the above measurement method and evaluation method 2. . The test results are shown in Table 2 below.
[Comparative Examples 1 to 11]
A curable composition was prepared in the same manner as in Example 1 except that the materials and blending amounts shown in Table 3 were used, and the obtained curable composition was measured and evaluated according to the above measurement method and evaluation method 2. . The test results are shown in Table 3 below.

  The curable compositions of Examples 1 to 15 have no yield point in the tensile stress-strain curve of the cured product, have an elongation at break of 200% or more, and are excellent in molding processability, as well as scratch resistance and adhesion. Also, the chemical resistance, weather resistance and oil resistance cosmetic properties were excellent. The curable compositions of Comparative Examples 1 and 2 did not contain the blocked isocyanate, or the blended amount of the blocked isocyanate was too small, so that the oil resistance cosmetic properties were poor. Since the curable composition of Comparative Example 3 had an excess of blocked isocyanate, the scratch resistance was poor, and tackiness was observed in the primary cured product. Since the curable composition of Comparative Example 4 had a small number average molecular weight of urethane (meth) acrylate, the primary cured product had a yield point and the elongation at break was small. Therefore, the moldability of the primary cured product was poor and the scratch resistance of the secondary cured product was low. Since the curable composition of Comparative Example 5 uses urethane acrylate made of a chain aliphatic polycarbonate diol having a number average molecular weight of 1000, the sticky feeling of the primary cured product is increased and is not suitable for practical use. Since the curable composition of Comparative Examples 6 and 7 uses a diol compound that is not a polycarbonate diol, the stickiness of the primary cured product is increased and is not suitable for practical use. Since the curable composition of Comparative Example 8 used urethane acrylate made of aromatic isocyanate, the weather resistance and adhesion were poor. Since the curable composition of Comparative Example 9 uses urethane acrylate made of a compound having three acryloyloxy groups in one molecule as the component (c), the primary cured product has a yield point, The elongation at break was also small. Therefore, the moldability of the primary cured product and the scratch resistance of the secondary cured product were poor. Since the curable composition of Comparative Example 10 used urethane acrylate having a molecular weight of 36000, the primary cured product and the secondary cured product had stickiness and were not suitable for practical use. Since the curable composition of Comparative Example 11 uses a urethane acrylate made of a diisocyanate having no alicyclic structure, the primary cured product and the secondary cured product are sticky and not suitable for practical use.

Claims (2)

In the tensile stress-strain curve diagram measured at 23 ° C. of urethane (meth) acrylate having a number average molecular weight of 5000 to 30000 obtained by reacting the following (a), (b), and (c): And (A) urethane (meth) acrylate having no yield point and having an elongation at break of 200% or more, and (B) a blocked aliphatic isocyanate,
The curable composition whose weight ratio of said (A) urethane (meth) acrylate and said (B) blocked aliphatic isocyanate is 95: 5-70: 30.
(A) a chain aliphatic polycarbonate diol having a number average molecular weight of 300 to 900 (b) an alicyclic diisocyanate (c) having one hydroxy group and one (meth) acryloyloxy group in the molecule (meth) Acrylic ester The curable composition according to claim 1, wherein the (B) blocked aliphatic isocyanate is at least one of a blocked aliphatic isocyanate trimer and a blocked aliphatic isocyanate burette.

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