JP2012072327A - Radical polymerizable group-containing urethane prepolymer, urethane (meth)acrylate, photocurable resin composition, hard coat film, and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radical polymerizable group-containing urethane prepolymer and urethane (meth)acrylate usable for a hard coat agent which (1) causes no tackiness just after application, (2) has flexibility to follow a curved surface of a mold when used for molding and not to cause appearance defects such as cracks and has mechanical strength allowing handling at molding temperature, and (3) shows high surface hardness sufficient as a had coat when finished as an end product; a photocurable resin composition using these compounds; and a hard coat film and a molded product using the photocurable resin composition.SOLUTION: The radical polymerizable group-containing urethane prepolymer has a molecular structure wherein (A) a compound having at least two hydroxyl groups and one free-radical polymerizable group in one molecule and a compound (B) having two or more isocyanate groups in one molecule are connected together. A side chain radical polymerizable group equivalent originating from the component (A) is 1,500 g/mol or less.

Description

  The present invention relates to a radically polymerizable group-containing urethane prepolymer, urethane (meth) acrylate, a photocurable resin composition, a hard coat film, and a molded article.

  Conventionally, a method of forming a cured film layer (hereinafter sometimes referred to as a hard coat layer) using a paint has been used in the case of imparting hardness mainly to the surface of a plastic product and improving the scratch resistance performance. It was. In particular, a hard coat layer is formed on many products in the interior and exterior of vehicles such as automobiles, home appliances and OA equipment, and the body and keypad portions of mobile phones.

  In general, a hard coat layer has been applied to a molded product by painting after molding. In other words, after molding by injection molding or the like, a method of applying a hard coat layer to the molded product by a method such as spray coating, etc., but the productivity is low because the process is divided into two, and complicated shapes There was a problem that it was difficult to uniformly form a hard coat layer on a molded product.

  On the other hand, recently, for the formation of a hard coat layer on a flat surface or a curved surface, a film having a hard coat layer (hereinafter sometimes referred to as a hard coat film) is injection-molded in a state of being inserted into a mold, and resin and Insert molding to be integrated and in-mold molding in which only a hard coat layer is transferred from a hard coat film to a molded product have been proposed. As a method for forming a hard coat layer on a hard coat film used in these molding methods, there is a system in which a hard coat agent is applied to a plastic film, dried, and then irradiated with active radiation such as ultraviolet rays as necessary. It is used.

  Since the hard coat material is usually in a liquid state or a solid state (hereinafter sometimes referred to as “tackiness”) before curing, in order to eliminate the adhesiveness, It is necessary to perform a curing process before stacking. However, since the crosslinking density of the coating film increases when the curing process is performed, the coating film becomes hard and brittle and cannot follow the curved surface in the process used for insert molding or in-mold molding, resulting in a defect in appearance such as cracks.

  If a curable resin that is not sticky at room temperature, such as some urethane acrylate resins, inconveniences such as blocking do not occur during winding or stacking. Furthermore, since it is not crosslinked at the time of molding, appearance defects such as cracks do not occur. However, when this method is used, the surface hardness after curing cannot be sufficiently increased, and the scratch resistance may be inferior. The reason is as follows. In general, a urethane acrylate resin is obtained by reacting an acrylate group-containing compound at both ends of a urethane prepolymer obtained by the reaction of a polyol having no functional group other than a hydroxyl group and a polyisocyanate having no functional group other than an isocyanate group. The radical polymerizable group can be introduced only at the terminal, and the number of radical polymerizable functional groups per molecule is limited. On the other hand, in the case of uncured and tack-free, the molecular weight of the radical polymerizable functional group density is inevitably lowered because the molecular weight must be increased. For this reason, it is difficult to obtain a urethane acrylate that is uncured, sufficiently tack-free, and sufficiently hard after curing, and that the hardness is sufficiently high due to the presence of an uncured thermoplastic polymer after curing. It was extremely difficult.

  Also, by appropriately blending a thermoplastic polymer that does not have cross-linking points, such as polystyrene and polymethyl methacrylate, and is tack-free at room temperature, and a curing material that has tack at room temperature and gives a hard coating film by the curing process. It is also possible to make it tack-free at room temperature without being cross-linked. However, the coating film may be remarkably softened by heat treatment during molding, resulting in poor appearance.

  On the other hand, Patent Document 8 and Patent Document 9 disclose the use of a compound having one (meth) acryloyl group as a part of the diol component in the production method of urethane (meth) acrylate. However, this document does not disclose any tackiness when uncured. In addition, the double bond equivalent of the urethane prepolymer disclosed in the examples is very sparse as 1700 g / mol to 6100 g / mol, which is insufficient to increase the hardness after curing to a satisfactory level. However, it could not be used as it is for the problem to be solved.

JP 2000-103987 A JP 2001-162732 A JP 2002-67238 A JP 2002-69333 A JP 2004-346228 A JP 2001-113649 A JP 2003-170540 A JP 2008-189808 A JP 2010-1414 A

  In view of the above-described problems of the prior art, the inventor has focused on the following physical properties as a curable composition used for a hard coat film for insert molding or in-mold molding. That is, (1) tackiness immediately after coating. When the film has tackiness, inconveniences such as blocking may occur when the film is wound or stacked. (2) To have flexibility and mechanical strength during molding. If it has the flexibility to follow the curved surface of the mold when it is used for molding, does not cause appearance defects such as cracks, and has enough mechanical strength to handle at the molding temperature, it may solve the problems in the conventional technology There is. (3) Surface hardness after molding. When the final product is obtained, it needs to have a high surface hardness sufficient as a hard coat.

  This invention is made | formed in view of the above point, The urethane prepolymer which can be used suitably for the hard-coat agent which can solve all the said problems (1)-(3), urethane (meth) acrylate, and It aims at providing the photocurable resin composition using this, and the hard coat film and molded article using the same.

  The inventor has set the above-mentioned problems and objectives, and as a result of various studies, the above-mentioned goals and problems have been achieved and solved, and the radical polymerizable group-containing urethane prepolymer and urethane (meth) acrylate according to the present invention are achieved. A photo-curable resin composition, a hard coat film and a molded product were completed.

  That is, in the present invention, at least (A) a compound having two hydroxyl groups and one radical polymerizable group in one molecule and (B) a compound having two or more isocyanate groups in one molecule are linked. It is a radically polymerizable group-containing urethane prepolymer having a molecular structure, wherein the side chain radically polymerizable group equivalent derived from the component (A) is 1500 g / mol or less.

In addition to the above (A) and (B), the present invention provides (C) a radical having a molecular structure in which a compound having two hydroxyl groups in one molecule and having no radical polymerizable group is linked. A polymerizable group-containing urethane prepolymer, which is a radically polymerizable group-containing urethane prepolymer having an equivalent side chain radical polymerizable group equivalent to component (A) of 1500 g / mol or less.
The above-mentioned radically polymerizable group-containing urethane prepolymer, wherein the urethane prepolymer containing an isocyanate group in the molecule further includes (D) a group that reacts with one isocyanate group and one or more (meth) acryloyl groups. A urethane (meth) acrylate obtained by reacting a compound, the above-mentioned radically polymerizable group-containing urethane prepolymer, a urethane prepolymer containing a hydroxyl group in the molecule, and (E) a group that reacts with one hydroxyl group and 1 A urethane (meth) acrylate obtained by reacting a compound containing at least one (meth) acryloyl group is also the present invention.

  The radical polymerizable group-containing urethane prepolymer and / or urethane (meth) acrylate according to the present invention can be suitably used as a photocurable resin composition containing a photopolymerization initiator and an organic solvent as essential components.

  The present invention also provides a hard coat film obtained by coating the above-mentioned photocurable resin composition on a plastic film as a hard coat agent, and further using the hard coat film to perform insert molding or in-mold. It is a molded body formed by molding.

  According to the present invention, there is substantially no tack in an uncrosslinked state immediately after coating and drying, and it has moderate flexibility and mechanical strength, and after molding, it is sufficient as a hard coat layer by irradiation with actinic radiation. Provides radically polymerizable group-containing urethane prepolymers, urethane (meth) acrylates, photocurable resin compositions using the same, hard coat films and molded products that can be suitably used for hard coating agents that exhibit high hardness It became possible to do.

  Hereinafter, the present invention will be described in detail.

  The radically polymerizable group-containing urethane prepolymer according to the present invention comprises (A) a residue of a compound having two hydroxyl groups and one radically polymerizable group in one molecule as a structural unit, and (B) one molecule. It contains a residue of a compound having two or more isocyanate groups therein, and the side chain radical polymerizable group equivalent derived from the component (A) is 1500 g / mol or less. Further, in order to adjust various physical properties, it is possible to introduce a residue of a compound having (C) two hydroxyl groups in one molecule and having no radical polymerizable group in place of (A). .

  The urethane prepolymer is also preferably used as it is as a component of the photocurable resin composition, and when it has an isocyanate at the end, it contains (D) one group that reacts with isocyanate in the molecule, and In the case where the compound containing one or more (meth) acryloyl groups and the urethane prepolymer have a hydroxyl group at the terminal, (E) one group that reacts with the hydroxyl group is contained in the molecule, and one or more ( It is also preferable to use it as a component of a photocurable resin composition by reacting with a compound containing a (meth) acryloyl group to add a (meth) acryloyl group at both ends.

  In addition, the urethane prepolymer having a hydroxyl group at the terminal and a compound containing (D) an isocyanate-reactive group and one or more (meth) acryloyl groups in the molecule, and (B) one molecule A compound having two or more isocyanate groups is mixed therein, a urethane prepolymer having an isocyanate group at the terminal or an isocyanate group (reacting with a hydroxyl group) is contained in the molecule, and at least one (meta It is also suitable as a synthesis method of the present invention to synthesize a urethane (meth) acrylate by generating a compound containing an acryloyl group in the system and reacting it as it is without isolation.

  Similarly, the urethane prepolymer having an isocyanate group at the terminal and a compound containing (E) one group that reacts with a hydroxyl group in the molecule and one or more (meth) acryloyl groups, (A) Mixing a compound having two hydroxyl groups and one radical polymerizable group in one molecule and / or (C) a compound having two hydroxyl groups in one molecule and no radical polymerizable group, In the system, a urethane prepolymer having a hydroxyl group at the terminal or a hydroxyl group (reacts with an isocyanate group) in the molecule and a compound containing one or more (meth) acryloyl groups is generated in the system and is not isolated. It is also suitable as a synthesis method of the present invention to react urethane as it is to synthesize urethane (meth) acrylate.

  Since general urethane (meth) acrylates can only have radical polymerizable groups at the ends, increasing the molecular weight to eliminate tackiness when uncured reduces the density of the polymerizable groups and decreases the performance of the cured film. As described above, since the urethane prepolymer of the present invention has a radical polymerizable group in the repeating unit, the molecular weight can be increased without decreasing the polymerizable group density.

  In the present specification, a polymer or oligomer having one or more urethane bonds in the main chain is referred to as a urethane prepolymer. A urethane prepolymer is often obtained mainly by a polyaddition reaction of a diol and a diisocyanate compound, but may be produced by other production methods. Any of those having an end group that is an isocyanate group, those having a hydroxyl group, and those having a functional group capable of reacting with these terminal groups and having a terminal group blocked with a compound having no other functional group are referred to as a urethane prepolymer in the present specification. Called. The radical polymerizable group-containing urethane prepolymer means a urethane prepolymer having a radical polymerizable group in the side chain.

  Urethane (meth) acrylate is a terminal functional group of a urethane prepolymer that is reacted with a compound having one or more (meth) acryloyl groups and one functional group capable of reacting with the terminal group. Is obtained by converting a part or all of the above to a (meth) acryloyl group-containing unit.

Known components can be used as appropriate for each component used in the synthesis, and will be described in detail below with examples.
<(A) Compound having two hydroxyl groups and one radical polymerizable group in one molecule>
This component reacts with (B) to extend the main chain of the urethane prepolymer in a linear manner and to have a radical polymerizable group on the side chain. These include, for example, trimethylolpropane mono (meth) acrylate, trimethylolethane mono (meth) acrylate, 2,3-dihydroxypropyl (meth) acrylate (also known as glycerin mono (meth) acrylate), 1,2,6-hexanetriol. Mono (meth) acrylate, 1,2,3-heptanetriol mono (meth) acrylate, 1,2,4-butanetriol mono (meth) acrylate, tris (2-hydroxyethyl) isocyanurate mono (meth) acrylate, etc. Examples thereof include mono (meth) acrylates of trifunctional alcohols. Particularly preferred is 2,3-dihydroxypropyl (meth) acrylate. These may be used alone or in combination of two or more.

These are preferably pure products, but they can be used even if different numbers of hydroxyl groups or radical polymerizable groups are mixed. The amount of impurities mixed is preferably about 10% by weight or less. If there are many impurities having 3 or more hydroxyl groups in one molecule, there is a risk of gelation, so care should be taken. However, the compound of the present invention can be used without any problem by using a compound having one hydroxyl group in one molecule as appropriate. Can be used for synthesis.
<(B) Compound having two or more isocyanate groups in one molecule>
This component serves to extend the main chain of the urethane prepolymer by reacting with a hydroxyl group and to introduce a flexible and robust urethane bond into the main chain.
(B) is a divalent to trivalent (preferably divalent) aliphatic polyisocyanate [C2-12, such as ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2, 4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate], alicyclic polyisocyanate [C4-15, such as isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), cyclohexylene diisocyanate, methylcyclohexyl Sylene diisocyanate], araliphatic polyisocyanate [C8-12, such as xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethyloxy Rylene diisocyanate (TMXDI)]; aromatic polyisocyanates [2,4- and / or 2,6-tolylene diisocyanate (TDI), diethylbenzene diisocyanate, 4,4′- and / or 2,4′-diphenylmethane diisocyanate (MDI) ), Naphthylene diisocyanate], modified products of these polyisocyanates (modified products containing urethane groups, carbodiimide groups, uretdione groups, isocyanurate groups, burette groups, etc.). These may be used alone or in combination of two or more.
Of the above (B), aromatic diisocyanates are preferable from the viewpoint of reactivity, and MDI and TDI are more preferable. From the viewpoint of weather resistance, aliphatic polyisocyanates and alicyclic polyisocyanates are preferred, and HDI, IPDI and HMDI are more preferred.
<(C) Compound having two hydroxyl groups in one molecule and no radical polymerizable group>
This component reacts with (B) to extend the main chain, but unlike (A), it does not introduce a radical polymerizable group into the side chain. In the present invention, the component (C) is not necessarily introduced, but by partially replacing the component (A), solubility in a solvent, molecular weight, radical polymerizable group density, glass transition temperature, viscosity, other resin and Easily improve the performance of photo-curing resin compositions, hard coating agents, and molded products, such as compatibility values of urethane prepolymers containing radical polymerizable groups, film formability, cured film hardness, and uncured film flexibility Can be adjusted. In addition, since many (C) components are cheap, there are many effects of reducing raw material cost by using in the range which does not affect various physical properties.

As component (C), ethylene glycol, propylene glycol; 2-methyl-1,3-propanediol, 1,3-butanediol, 2,4-heptanediol, 2,2-diethyl-1,3-propanediol 2-methyl-2-propyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3- An aliphatic dihydric alcohol in which an alkylene group such as pentanediol or 2-butyl-2-ethyl-1,3-propanediol is a trimethylene group; an aliphatic group in which an alkylene group such as 1,4-butanediol is a tetramethylene group Dihydric alcohol; alkylene such as 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,5-hexanediol An aliphatic dihydric alcohol in which is a pentamethylene group; an aliphatic dihydric alcohol in which an alkylene group such as 1,6-hexanediol or 2-ethyl-1,6-hexanediol is a hexamethylene group; 1,7-heptane An aliphatic dihydric alcohol in which an alkylene group such as diol is a heptamethylene group; an aliphatic dihydric alcohol in which an alkylene group of 1,8-octanediol or 2-methyl-1,8-octanediol is an octamethylene group; 1 , 9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,20-eicosanediol. 1,3-cyclohexanediol, 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, cyclohexane-1,4-diethanol, 2,2-bis (4-hydroxycyclohexyl) propane, 2,7- An aliphatic dihydric alcohol in which a substituent of an alkylene group such as norbornanediol forms a ring; inside an alkylene group such as diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol Aliphatic dihydric alcohols in which carbon atoms are substituted with oxygen atoms; carbon atoms inside alkylene groups such as 2,5-tetrahydrofurandimethanol and 1,4-bis (hydroxyethoxy) cyclohexane are substituted with oxygen atoms Aliphatic dihydric alcohols such substituent groups of the alkylene group form a ring are exemplified with there. Aromatics such as p-xylylene diol, p-tetrachloroxylylene diol, 1,4-bis (hydroxyethoxy) benzene, 2,2-bis [(4-hydroxyethoxy) phenyl] propane Group diol compounds, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone polyol, ethylene oxide modified bisphenol, propylene oxide modified bisphenol, polyglycol or dihydric alcohol obtained by copolymerization of ethylene oxide and propylene oxide and 2 Examples thereof include polyester polyols obtained by a dehydration condensation reaction with a basic acid. These may be used alone or in combination of two or more.
<(D) Compound containing a group that reacts with one isocyanate group and one or more (meth) acryloyl groups>
When the urethane prepolymer is synthesized under the condition that the total amount of hydroxyl groups derived from the components (A) and (C) is less than the amount of isocyanate groups derived from the component (B), the end of the urethane prepolymer to be formed becomes an isocyanate group. . When (D) is reacted with this isocyanate group, a (meth) acryloyl group can be further introduced into the terminal, and the coating strength after curing can be improved.

  When the urethane prepolymer is synthesized under a condition in which the total amount of hydroxyl groups derived from the components (A) and (C) exceeds the amount of isocyanate groups derived from the component (B), the end of the urethane prepolymer to be formed becomes a hydroxyl group. A urethane prepolymer having a hydroxyl group at the terminal, (D), and (B) are mixed, the urethane prepolymer having an isocyanate group at the terminal and an isocyanate group (reacting with a hydroxyl group) are contained in the molecule in the system, and It is also suitable as a synthesis method of the present invention to synthesize a urethane (meth) acrylate by generating a compound containing one or more (meth) acryloyl groups in the system and reacting it as it is without isolation.

Although it does not specifically limit about the group which reacts with the isocyanate group contained in (D), A hydroxyl group and a carboxyl group are mentioned. Of these, a hydroxyl group is preferred.
As the component (D), hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) Acrylate, glycerin di (meth) acrylate, trimethylolpropane di (meth) acrylate, 5-methyl-1,2,4-heptanetriol di (meth) acrylate, 1,2,6-hexanetriol di (meth) acrylate, Examples include pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate. These may be used alone or in combination of two or more. Among these, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate are preferable.
<(E) Compound containing a group that reacts with one hydroxyl group and one or more (meth) acryloyl groups>
When the urethane prepolymer is synthesized under a condition in which the total amount of hydroxyl groups derived from the components (A) and (C) exceeds the amount of isocyanate groups derived from the component (B), the end of the urethane prepolymer to be formed becomes a hydroxyl group. When (E) is reacted with this hydroxyl group, a (meth) acryloyl group can be further introduced into the terminal, and the coating strength after curing can be improved.
When the urethane prepolymer is synthesized under the condition that the total amount of hydroxyl groups derived from the components (A) and (C) is less than the amount of isocyanate groups derived from the component (B), the end of the urethane prepolymer to be formed becomes an isocyanate group. . A urethane prepolymer having an isocyanate group at the terminal is mixed with (E) and (A) and / or (C), and a urethane prepolymer having a hydroxyl group at the terminal or a hydroxyl group (reacts with an isocyanate group) in the system. As a synthesis method of the present invention, a compound containing one or more (meth) acryloyl groups is generated in the system and reacted as it is without isolation to synthesize urethane (meth) acrylate. Is preferred.

Although it does not specifically limit about the group which reacts with the hydroxyl group contained in (E), An isocyanate group, a carboxyl group, an acid anhydride structure, etc. are mentioned. Of these, an isocyanate group is preferred.
Examples of the component (E) include (meth) acryloyloxyethyl isocyanate and 1,1-bis {(meth) acryloyloxymethyl} ethyl isocyanate.
<The urethane prepolymer of the present invention, urethane (meth) acrylate synthesis method>
There are no particular limitations on the synthesis method and synthesis conditions of the radical polymerizable group-containing urethane prepolymer or urethane (meth) acrylate of the present invention, and various known synthesis methods can be suitably used.
In the step of producing a urethane prepolymer by reacting (A) and (B), or (A) and (C) and (B), each component may be charged all at once, either or all However, depending on the size, structure, etc. of the reaction vessel, it is preferable to continuously drop at least one component. The temperature in the reaction system at the time of dripping is 40-100 degreeC, Preferably it is 50-90 degreeC. When the reaction temperature is lower than 40 ° C., it takes a long time to complete the reaction, and the production efficiency is remarkably lowered. On the other hand, when the reaction temperature is higher than 100 ° C., the reaction is excessively promoted and the by-products increase, which is not preferable.
The dropping rate is not particularly limited as long as the temperature in the reaction system can be maintained. Although dripping time should just be time which can maintain the temperature in said reaction system, it is 0.5 to 30 hours normally, Preferably it is 0.5 to 20 hours. If the time is shorter than 0.5 hours, the temperature rises significantly in some cases, making temperature control difficult. On the other hand, if it is longer than 30 hours, an excessive thermal history may be given to the urethane prepolymer to cause a reaction of the polymerizable group, which is not preferable because production efficiency is also lowered. Depending on the reaction conditions, the reaction may not be completed when the dropping is completed, and the reaction can be completed by continuing the reaction operation as necessary.

  Since the produced urethane prepolymer is a tack-free solid at room temperature in a pure product, the reaction is preferably carried out in a suitable solvent. When performing in a solvent, the solvent to be used is not particularly limited, but any solvent that does not substantially contain a functional group capable of reacting with a hydroxyl group or an isocyanate group can be preferably used. Preferred solvents include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate and methoxypropyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; diethyl ether , Ether solvents such as dibutyl ether, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, and other known organic solvents. The type of organic solvent to be used is determined in consideration of the solubility of the resulting resin and the reaction temperature, but the boiling point of methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, etc. is 120 ° C. or less in terms of the difficulty of remaining the residual solvent during drying. The organic solvent is preferable. Only one type of these may be used, or two or more types may be used.

The reaction between the hydroxyl group and the isocyanate group may be carried out without a catalyst, and if a sufficient reaction rate cannot be obtained, a catalyst may be appropriately added. Examples of the catalyst include organic tin compounds such as dibutyltin dilaurate, dibutyltin dioctate and tin octoate, other organometallic compounds such as copper naphthenate, cobalt naphthenate and zinc naphthenate, triethylamine, and 1,4-diazabicyclo [2. 2.2] octane, 2,6,7-trimethyl-1-diazabicyclo [2.2.2] octane, 1,8-diazabicyclo [5.4.0] undecene, N, N-dimethylcyclohexylamine, pyridine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N, N, N ′, N′-penta Methyldiethylenetriamine, N, N, N ′, N′-tetra (3-dimethylaminopropyl) -methanediamine, N, N′-dimethyl Examples include amine compounds such as perazine and 1,2-dimethylimidazole and salts thereof, and trialkylphosphine compounds such as tri-n-butylphosphine, tri-n-hexylphosphine, tricyclohexylphosphine, and tri-n-octylphosphine. . Among these, dibutyltin dilaurate and tin octoate, which accelerate the reaction rate in a small amount and have a large effect on aliphatic isocyanate, are preferably used. The addition amount of the catalyst is preferably 0.1% by weight or less with respect to the charged amount of raw materials. If it exceeds 0.1% by weight, the catalytic effect becomes excessive, and a large amount of reaction heat is generated, which may make temperature control impossible.
In the step of producing urethane (meth) acrylate by reacting (D) or (E) with the urethane prepolymer obtained by the reaction of (A) and (B) or (A) and (C) and (B). The (D) or (E) is preferably charged into the reaction system dropwise with stirring. When the entire amount is charged in a short time, although it depends on the structure of the raw material compound, the molecular weight, the structure of the reaction vessel, the shape of the stirring blade, the stirring speed, etc., in general, the temperature rises significantly and temperature control becomes difficult. Furthermore, the reaction is excessively promoted, the viscosity of the reaction product is greatly increased, and in some cases, there is a possibility of gelation.

  In addition, the urethane prepolymer having a hydroxyl group at the terminal and a compound containing (D) an isocyanate-reactive group and one or more (meth) acryloyl groups in the molecule, and (B) one molecule A compound having two or more isocyanate groups is mixed therein, a urethane prepolymer having an isocyanate group at the terminal or an isocyanate group (reacting with a hydroxyl group) is contained in the molecule, and at least one (meta It is also suitable as a synthesis method of the present invention to synthesize a urethane (meth) acrylate by generating a compound containing an acryloyl group in the system and reacting it as it is without isolation.

Similarly, the urethane prepolymer having an isocyanate group at the terminal and a compound containing (E) one group that reacts with a hydroxyl group in the molecule and one or more (meth) acryloyl groups, (A) Mixing a compound having two hydroxyl groups and one radical polymerizable group in one molecule and / or (C) a compound having two hydroxyl groups in one molecule and no radical polymerizable group, In the system, a urethane prepolymer having a hydroxyl group at the terminal or a hydroxyl group (reacts with an isocyanate group) in the molecule and a compound containing one or more (meth) acryloyl groups is generated in the system and is not isolated. It is also suitable as a synthesis method of the present invention to react urethane as it is to synthesize urethane (meth) acrylate.
When using these production methods, each component may be added to the system all at once, or may be added dropwise or divided continuously or discontinuously.
The ratio of the urethane prepolymer end group and the functional group in (D) or (E) is not particularly limited. When (D) is reacted with an isocyanate end-containing urethane prepolymer, {functional group in (D)} / { The ratio of the terminal isocyanate group} is preferably 1.0 to 3.0, more preferably 1.05 to 2, and even more preferably 1.1 to 1.5. If the ratio is less than 1.0, the stability may be slightly lowered, and if it exceeds 3.0, the tack-free property may be lowered. In addition, when (E) is reacted with the hydroxyl group-containing urethane prepolymer, the ratio of {terminal hydroxyl group} / {functional group in (E)} is preferably 1.0 to 3.0, 1.05 It is preferable that it is -2, and it is still more preferable that it is 1.1-1.5. If the ratio is less than 1.0, the stability may be slightly lowered, and if it exceeds 3.0, the hardness of the cured coating film may not be sufficiently high.
A catalyst can be added to the reaction as necessary. Examples of the catalyst include organic tin compounds such as dibutyltin dilaurate, dibutyltin dioctate and tin octoate, other organometallic compounds such as copper naphthenate, cobalt naphthenate and zinc naphthenate, triethylamine, and 1,4-diazabicyclo [2. 2.2] octane, 2,6,7-trimethyl-1-diazabicyclo [2.2.2] octane, 1,8-diazabicyclo [5.4.0] undecene, N, N-dimethylcyclohexylamine, pyridine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N, N, N ′, N′-penta Methyldiethylenetriamine, N, N, N ′, N′-tetra (3-dimethylaminopropyl) -methanediamine, N, N′-dimethyl Examples include amine compounds such as perazine and 1,2-dimethylimidazole and salts thereof, and trialkylphosphine compounds such as tri-n-butylphosphine, tri-n-hexylphosphine, tricyclohexylphosphine, and tri-n-octylphosphine. . Among these, dibutyltin dilaurate and tin octoate, which accelerate the reaction rate in a small amount and have a large effect on aliphatic isocyanate, are preferably used. The addition amount of the catalyst is preferably 0.1% by weight or less with respect to the charged amount of raw materials. If it exceeds 0.1% by weight, the catalytic effect becomes excessive, and a large amount of reaction heat is generated, which may make temperature control impossible.
The temperature in the reaction system when (D) or (E) is dropped depends on the size, structure, etc. of the reaction vessel, but is 40 to 100 ° C., preferably 50 to 90 ° C. When it exceeds 100 ° C., a polymerization reaction of (meth) acryloyl groups is induced, which may cause excessive thickening. On the other hand, when the temperature is lower than 40 ° C., the reaction time becomes longer, and the production efficiency is remarkably lowered.
The dropping rate is not particularly limited as long as the temperature in the reaction system can be maintained.
Although dripping time should just be time which can maintain the temperature in said reaction system, it is 0.5 to 30 hours normally, Preferably it is 0.5 to 20 hours. If the time is shorter than 0.5 hours, the temperature rises significantly in some cases, making temperature control difficult. On the other hand, if it is longer than 30 hours, an excessive thermal history may be imparted to the urethane (meth) acrylate to cause a reaction of the polymerizable group, and the production efficiency is also lowered, which is not preferable. Depending on the reaction conditions, the reaction may not be completed when the dropping is completed, so that the reaction can be completed by continuing the reaction operation as necessary.

  During the reaction in the present invention, various additives can be added to the reaction system. The additive is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include a radical polymerization inhibitor, a monofunctional hydroxyl group-containing compound, and a monofunctional isocyanate group-containing compound.

The radical polymerization inhibitor is preferably added in order to suppress the gelation of the system due to the polymerization reaction of the radical polymerizable groups derived from the components (A), (D) and (E). In order to enhance the effect of the radical polymerization inhibitor, it is also effective to use bubbling of an oxygen / nitrogen mixed gas having an oxygen partial pressure of 4 to 21% in the reaction system aqueous phase.
As specific examples of the radical polymerization inhibitor, for example, the following compounds are suitable. These can use 1 type (s) or 2 or more types.
2-t-butylhydroquinone, 2-t-amylhydroquinone, 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, tris (3-t-butyl-4-hydroxybenzyl) isocyanate , Tris (3-t-amyl-4-hydroxybenzyl) isocyanate, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,1,3-tris (2 -Ethyl-4-hydroxy-5-t-amylphenyl) butane, 4.4-butylidene-bis (3-methyl-6-tert-butylphenol), 4,4-butylidene-bis (3-methyl-6-t -Amylphenol), tetrakis [methylene-3- (3-tert-butyl-4-hydroxyphenyl) propionate] methane, triethyleneglycol Rubis [3- (3-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-di-methyl-2- {β- (3-t-butyl-4-hydroxyphenyl) Propynonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris (3-tert-butyl-4-hydroxy Benzyl) benzene, N, N′-bis [3- (3-tert-butyl-4-hydroxyphenyl) propionyl] hexamethylenediamine, 3-tert-butyl-4-hydroxybenzyl phosphate diethyl ester, di (2-t -Butyl-4-hydroxyphenyl) pentaerythritol diphosphite, tris (2-t-butyl-4-hydroxyphenyl) phosphite, 2,2'-oxa Midobis [ethyl-3- (3-t-butyl-4-hydroxyphenyl) propionate], N-nitroso-N-phenylhydroxylamine aluminum, N-nitroso-N-phenylhydroxylamine ammonium, 4-hydroxy-2,2 , 6,6-tetramethylpiperidinyloxy and the like can be preferably used.

Monofunctional hydroxyl group-containing compound and monofunctional isocyanate group-containing compound act as a terminator for stopping the urethanization reaction, but when a small degree of addition is desired to adjust the degree of polymerization, a product with a desired molecular weight can be obtained. It is. Moreover, when using the component which has a 3 or more hydroxyl group as a small component or an impurity, it is effective for gelatinization suppression.
Monofunctional hydroxyl group-containing compounds include methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol, t-butanol, n-pentanol, n-hexanol, 2-ethylhexanol, n-octanol, iso Examples thereof include alcohols having 1 to 24 carbon atoms such as octanol.
Examples of the monofunctional isocyanate group-containing compound include monoisocyanates having 2 to 24 carbon atoms such as phenyl isocyanate, octadecyl isocyanate, and cyclohexyl isocyanate.

  Also, the ratio of (A) a compound having two hydroxyl groups and one radical polymerizable group in one molecule and (C) a compound having two hydroxyl groups in one molecule and having no radical polymerizable group Although there is no restriction | limiting in particular, It is preferable that {the amount of hydroxyl groups in (A)} / {the amount of hydroxyl groups in (A) + the amount of hydroxyl groups in (C)} is 0.2 to 1. More preferably, it is 0.3-1 and still more preferably 0.5-1. When this ratio is less than 0.2, the density of the radical polymerizable group contained in the urethane prepolymer side chain to be produced is small, so that the curability is lowered and the strength of the cured film may not be sufficiently increased.

The ratio of the total amount of hydroxyl groups in (A) and (C) and the amount of isocyanate groups in (B) is not particularly limited, but {hydroxyl group amount in (A) + hydroxyl group amount in (C)} / It is preferable that {isocyanate amount in (B)} is 0.5 to 2 in terms of molar ratio. More preferably, it is 0.7-1.5, More preferably, it is 0.8-1.2. When the ratio is less than 0.5 or more than 2, the average degree of polymerization is remarkably lowered, and thus there is a possibility that a tacky feeling may remain when the resulting urethane prepolymer is dried.
<Radically polymerizable group-containing urethane prepolymer>
The radical polymerizable group-containing urethane prepolymer of the present invention is obtained by the reaction of (A) and (B) or (A), (C) and (B) as described above, and is a side chain derived from the component (A). The radical polymerizable group equivalent is 1500 g / mol or less. The side chain radical polymerizable group equivalent derived from the component (A) is preferably 1200 g / mol or less, and more preferably 1000 g / mol or less. If it exceeds 1500 g / mol, the double bond density becomes too sparse, so that the crosslinking density after curing is not sufficiently high, which is disadvantageous in that the hard coat performance is lowered.

In addition, the side chain radical polymerizable group equivalent in this application represents the weight of the urethane prepolymer containing 1 mol of side chain radical polymerizable groups. For example, 1500 g / mol means that 1500 g of urethane prepolymer contains 1 mol of side chain radical polymerizable groups, and the smaller the value, the higher the side chain radical polymerizable group density. The side chain radical polymerizable group equivalent can be determined by a known analysis method such as a peak ratio of double bond protons to the whole proton by ¹ H-NMR measurement or iodine value titration. Further, when the production method is known and the urethane prepolymer synthesis reaction is substantially completed, it can be calculated from the charged weight ratio and the molecular weight of the component (A) by the following formula.
(Equivalent side chain radical polymerizable group) = (A) molecular weight × {(A) charged weight + (B) charged weight + (C) charged weight} / (A) charged weight There is no particular limitation as long as the above conditions are satisfied. The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene is preferably in the range of 1,000 to 1,000,000. More preferably, it is 1500-500000, More preferably, it is 2000-300000, Most preferably, it is 2500-200000. If Mw is less than 1000, tack-free property in an uncured state may be lost, and if it exceeds 1000000, the solution viscosity may increase significantly and handling may be difficult.

The terminal group at the end of the synthesis (one or both ends in the case of a completely linear structure, or a part or all of the terminals in the case of containing a branch) is either hydroxyl group or isocyanate group It has become. They may be used as they are, and in order to impart stability and functionality, some or all of these end groups are blocked with a compound having one functional group that can react with the end group and no other functional group. It doesn't matter. In particular, for urethane prepolymers having isocyanate groups at the ends, end-group blocking is advantageous because stability is improved.
<Urethane (meth) acrylate>
The urethane (meth) acrylate of the present invention is a terminal group of a radically polymerizable group-containing urethane prepolymer having a side chain radically polymerizable group equivalent derived from the component (A) of 1500 g / mol or less (in a completely linear one) A compound having one or more (meth) acryloyl groups and one or more (meth) acryloyl groups capable of reacting with a terminal group at a part or all of one or both terminals, or a part or all of the terminals including a branch. It is obtained by reacting.

Although there will be no restriction | limiting in particular if the said conditions are satisfy | filled, It is preferable that the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) and calculated in standard polystyrene conversion exists in the range of 1000-1 million. More preferably, it is 1500-500000, More preferably, it is 2000-300000, Most preferably, it is 2500-200000. If Mw is less than 1000, tack-free property in an uncured state may be lost, and if it exceeds 1000000, the solution viscosity may increase significantly and handling may be difficult.
<Tack-free>
After synthesizing the urethane prepolymer or urethane (meth) acrylate, it is applied as it is or after being diluted with a solvent as necessary, and then applied to a plastic film such as PET with a bar coater or the like. Adjust the coating surface obtained by drying in an oven or hot plate to the set temperature, and use a finger or other instrument to make the coating surfaces contact each other (for at least 1 second with a force of 3 kgf / cm ² or more) Tack-free property is good at this temperature when the film is not transferred or markedly rough when it is quickly peeled and pressed, and if there is no change in the paint film, it can be judged that the tack-free property is excellent at that temperature. .

  Both urethane prepolymers and urethane (meth) acrylates can be used if the coating temperature during pressure bonding is normal or higher and the tack-free property is good or excellent, but the tack-free property is good or excellent under the test conditions of 40 ° C or higher. Is preferred. It is more preferable if the tack-free property is good or excellent at 60 ° C. or higher, and it is very preferable if the tack-free property is good or excellent at 80 ° C. or higher. It is most preferable that the tack-free property is good or excellent even at 100 ° C or higher. If the tack-free property is good or excellent at 40 ° C. or higher, it is convenient that it can be stored in the summer by being stacked or wound up without an interleaf. If the tack-free property is good or excellent at 60, 80, or 100 ° C. or higher, it can be wound up without any special cooling step after coating and drying, which is very convenient in practice.

The solvent used in the test is not particularly limited, but it is preferable to select a solvent that sufficiently dissolves the sample and sufficiently evaporates under dry conditions. Moreover, although there is no restriction | limiting in particular about the dry thickness of a coating film, Usually, a test is done at 1-10 micrometers.
<Photocurable resin composition>
The photocurable resin composition of the present invention is not particularly limited as long as it contains the urethane prepolymer and / or urethane (meth) acrylate, a photopolymerization initiator and an organic solvent as essential components.

Although there is no restriction | limiting in particular about the compounding ratio of the said urethane prepolymer and / or urethane (meth) acrylate, It is preferable that it is 5 to 90 weight% of the whole composition. More preferably, it is 10-80 weight%, More preferably, it is 15-70 weight%. If the blending ratio is less than 5% by weight, the productivity such as drying property may be lowered, and if it exceeds 90% by weight, the leveling property may be lowered.
As the photopolymerization initiator, those having activity with respect to the wavelength of the light source to be used are appropriately blended, and those that generate appropriate active species can be used.
Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, α-phenylbenzoin, anthraquinone, methylanthraquinone, acetophenone, 2,2-diethoxyacetophenone, 2, 2-dimethoxy-2-phenylacetone, benzyldiacetylacetophenone, benzophenone, p-chlorobenzophenone, 2-hydroxy-2-methylpropiophenone, diphenyldisulfide, tetramethylthiuram sulfide, α-chloromethylnaphthalene, anthracene, hexachlorobutadiene, Pentachlorobutadiene, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1,2-hydroxy-2-methyl-1- And phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, and the like.
These photopolymerization initiators include, for example, “Irgacure 651” “Irgacure 184” “Irgacure 184D” “Darocure 1173” “Irgacure 500” “Irgacure 1000” “Irgacure 2959” “Irgacure 907” “Irgacure 369” “Irgacure 379” “ Irgacure 1700, “Irgacure 149,” “Irgacure 1800,” “Irgacure 1850,” “Irgacure 819,” “Irgacure 784,” “Irgacure 261” (above, Ciba Japan Co., Ltd.) and other products that are commercially available I can do it.
The photopolymerization initiator is preferably blended in a proportion of 0.5 to 20% by weight based on the total solid content of the photocurable resin composition. More preferably, it is 1-15 weight%, More preferably, it is 2-10 weight%. A photoinitiator may be used individually by 1 type and may be used in combination of 2 or more type.

Since the photocurable resin composition of the present invention is solid or has a very high viscosity in the absence of a solvent and is very difficult to apply in the form of a thin film, it is necessary to contain an organic solvent.
Although there is no limitation in particular about a solvent, if it does not contain the functional group which can react with this-application urethane prepolymer and / or urethane (meth) acrylate to mix | blend, it can use suitably. Preferred solvents include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate and methoxypropyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; diethyl ether , Ether solvents such as dibutyl ether, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, and other known organic solvents. The type of organic solvent to be used is determined in consideration of the solubility of the resulting resin and the polymerization temperature, but the boiling point of methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, etc. is 120 ° C. or less in terms of the difficulty of remaining the residual solvent during drying. The organic solvent is preferable. Only one type of these may be used, or two or more types may be used. The amount of solvent used is not particularly limited, but is preferably adjusted so that the viscosity of the composition is suitable for the coating method employed. The preferred amount is 5 to 90% by weight of the total composition, more preferably 10 to 85% by weight, and still more preferably 20 to 80% by weight.
Although not an essential component, the photocurable resin composition of the present application contains a low molecular or high molecular compound having a radical polymerizable group (excluding the radical polymerizable group-containing urethane prepolymer and urethane (meth) acrylate of the present invention). I can do it. These are not particularly limited as long as they are compounds that can be made high molecular weight by the active species generated by light irradiation to the photopolymerization initiator to be blended, but darkly react with the urethane prepolymer and / or urethane (meth) acrylate to be blended. Those having no functional group are preferred. Those having an ethylenically unsaturated bond such as a (meth) acryloyl group, an aromatic vinyl structure, and a vinyl ether group are preferred as the functional group for increasing the molecular weight. The number of functional groups for increasing the molecular weight in one molecule is not particularly limited, and may be one or two or more. Of these, monofunctional or polyfunctional (meth) acrylate compounds are particularly preferred.

  Examples of monofunctional (meth) acrylate compounds include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and tert-butyl (meth) acrylate. , Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) Acrylate, phenyl (meth) acrylate, (meth) acryloylmorpholine, adamantyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, 2 Ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, isoamyl (meth) acrylate, isodecyl (meth) acrylate, isostearyl (Meth) acrylate, ethoxyethoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, nonylphenoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetracyclododecanyl (meth) acrylate , Tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, 2- (meth) acrylo Ruokishimechiru -2-methyl bicycloheptane adamantyl (meth) acrylate.

  Examples of the polyfunctional (meth) acrylate include 1,4-butanediol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, and 1,6-hexanediol di (meth). Acrylate, neopentyl glycol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, ethylene glycol di Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol, ethylene oxide modified phosphoric acid (meth) Acrylate, ethylene oxide Id-modified alkylated phosphoric acid di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyether (meth) acrylate, diethylaminoethyl (meth) acrylate , Norbornane dimethanol di (meth) acrylate, norbornane diethanol di (meth) acrylate, di (meth) acrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to norbornane dimethanol, tricyclodecane dimethanol di (meth) ) Addition of 2 moles of ethylene oxide or propylene oxide to acrylate, tricyclodecane diethanol di (meth) acrylate, tricyclodecane dimethanol Obtained by adding 2 moles of ethylene oxide or propylene oxide to di (meth) acrylate, pentacyclopentadecanedimethanol di (meth) acrylate, pentacyclopentadecanediethanol di (meth) acrylate and pentacyclopentadecanedimethanol Di (meth) acrylate of diol, di (meth) acrylate of diol obtained by adding 2 moles of ethylene oxide or propylene oxide to pentacyclopentadecane diethanol, dimethylol dicyclopentane di (meth) acrylate, hydroxypivalaldehyde modified tri Methylolpropane di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) Acrylate, propylene oxide modified bisphenol A di (meth) acrylate, tris (2-acryloyloxyethyl) isocyanurate, tris (2-acryloyloxypropyl) isocyanurate, tris (2-acryloyloxybutyl) isocyanurate, tris (2- Methacryloyloxyethyl) isocyanurate, tris (2-methacryloyloxypropyl) isocyanurate, tris (2-methacryloyloxybutyl) isocyanurate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, 3 moles or more per mole of trimethylolpropane Birds triol obtained by adding alkylene oxide or propylene oxide (meth) acrylate, polyfunctional (meth) acrylates such as poly (meth) acrylate of dipentaerythritol.

  In addition, monofunctional or polyfunctional compounds exemplified below can also be used as the reactive diluent. Nitrogen-containing unsaturated monomers such as (meth) acrylamide, N, N′-dimethylaminoethyl (meth) acrylate, N, N′-dimethylaminopropylacrylamide, vinylpyridine, divinylpyridine, vinylimidazole; styrene, α-methylstyrene Aromatic unsaturated monomers such as vinyltoluene, 4-vinylpyridine, divinyltoluene, divinylbenzene; vinyl esters such as vinyl acetate; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, ethylene glycol divinyl ether, butylene Glycol divinyl ether, cyclohexane diol divinyl ether, cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether Vinyl ethers such as tellurium, trimethylolpropane trivinyl ether and pentaerythritol tetravinyl ether; unsaturated cyanide compounds such as (meth) acrylonitrile; vinyl compounds such as vinylpyrrolidone and vinylcaprolactone; maleimide compounds such as phenylmaleimide, benzylmaleimide and cyclohexylmaleimide And silicon-containing unsaturated monomers such as vinyltrimethoxysilane and γ-methacrylopropylmethoxysilane and polymerizable ultraviolet absorbing monomers. Further, compounds containing different polymerizable functional groups such as 2- (2-vinyloxyethoxy) ethyl (meth) acrylate and 2-vinyloxyethyl (meth) acrylate in the same molecule can also be used.

Polymeric functional group-containing polymer compounds other than the urethane prepolymer and / or urethane (meth) acrylate of the present application can also be used. Various compounds such as urethane (meth) acrylate, epoxy (meth) acrylate, acrylic (meth) acrylate, etc. Can be used.
Only one type of these may be used, or two or more types may be used. Although there is no limitation in particular about the addition amount of a reactive diluent, 0 to 30 weight% of the whole composition is preferable. More preferably, it is 0-20 weight%, More preferably, it is 0-10 weight%.
The photocurable resin composition of the present invention can contain various known additives in addition to the above components. For example, organic or inorganic fillers, organic or inorganic fine particles, release agents such as silicone release agents, coupling agents such as silane coupling agents, bactericides, preservatives, plasticizers, leveling regulators, color pigments, It may contain an antirust pigment, an antioxidant, an ultraviolet absorber, a light stabilizer such as a hindered amine, an antistatic agent, and the like.

Although there is no limitation in particular about the addition amount of the said various additives, 0 to 30 weight% of the whole composition is preferable in total. More preferably, it is 0-20 weight%, More preferably, it is 0-10 weight%.
<Hard coat film>
The hard coat film of this invention can be obtained with the manufacturing method including the process of apply | coating the photocurable resin composition of this invention to a plastic film.

Although it is not particularly limited as a plastic film, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, Polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetherimide film, polyimide film , Fluorine resin film, nylon film, Le resin film or the like can be used.
For the purpose of improving adhesion to hard coating agents, surface roughening treatment such as sandblasting or solvent treatment, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, etc. Surface treatment such as oxidation treatment of the surface may be performed.
The film may be preliminarily provided with a pressure-sensitive adhesive layer or printing or coating for imparting design properties on one side or both sides before application of the photocurable resin composition.
For the coating, a known method such as a gravure coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method or the like can be used. You may apply manually using an applicator or a bar coater, without using a coating machine. If the viscosity of the hard coating agent is higher than the viscosity suitable for coating, the viscosity may be adjusted using a solvent. Solvents that can be used are as described above.
Since the photocurable resin composition contains a solvent, it is necessary to dry after coating. The drying temperature may be determined in consideration of the length of the drying line, the line speed, the coating amount, the residual solvent amount, the type of substrate, and the like. If the substrate is a polyethylene terephthalate film, the general drying temperature is 50 to 150 ° C. When there are a plurality of dryers in one line, each dryer may be set to a different temperature and wind speed. In order to obtain a coating film having a good coating appearance, it is preferable that the drying condition on the inlet side is mild.
Although there is no restriction | limiting in particular in coating thickness, It is preferable to apply so that a film thickness may become 1-50 micrometers after drying. More preferably, it is 1-30 micrometers, More preferably, it is 1-20 micrometers.

  When the substrate is a long film after coating and drying, it is usually wound up.

The hard coat film obtained through the above steps can be suitably used as a hard coat film for insert molding and in-mold molding.
<Molded product>
The hard coat film can be used for insert molding and in-mold molding by known methods. That is, after sandwiching the film in a mold heated to the molding temperature, the resin is poured into the film and the resin to be integrated (insert molding), or after sandwiching the film in the mold heated to the molding temperature, The film can be poured into a resin and pressure-bonded, and then only the base film is peeled off, whereby the layer including the hard coat layer can be suitably transferred to the surface of the resin molded product (in-mold molding).

In any method, after molding, the photopolymerization initiator is decomposed by irradiating the molded product with ultraviolet rays having a wavelength including the absorption wavelength of the photopolymerization initiator, and the radically polymerizable group-containing urethane prepolymer and / or urethane (meta ) Acrylate can be polymerized and cured. When other polymerizable compounds are added, they are simultaneously cured. The ultraviolet irradiation may be performed after the molded product is taken out of the mold, or may be performed in a state where the molded product is in the mold if a transparent mold is used. When irradiating after taking out from a metal mold | die, irradiation may be performed in the air, and in order to prevent hardening inhibition, you may irradiate under inert gas, such as nitrogen gas. Although there is no restriction | limiting in the light source of ultraviolet irradiation, A super high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp etc. are used, and it is 100-5000 mJ / cm < ² > in the wavelength range of 100-400 nm, Preferably it is 200-400 nm. It is preferable to irradiate ultraviolet rays having energy.

  There are no particular restrictions on the base material of the molded product, and heat such as polystyrene, polymethyl methacrylate, polyethylene, polypropylene, ABS (acrylonitrile-butadiene-styrene) resin, PET (polyethylene terephthalate) resin, PBT (polybutylene terephthalate) resin, etc. Thermosetting resins such as plastic resins, unsaturated polyester resins, epoxy acrylate resins, urethane acrylate resins, and phenol resins may be used. Further, a bulk molding compound or a sheet molding compound in which a thermosetting resin is reinforced with a fibrous reinforcing agent can be used. By coating the hard coat film of the present invention on the surface of these substrates, it is possible to impart functions such as a better appearance and scratch resistance.

  The use of the molded product produced in the above process is not particularly limited. For example, it can be used for the interior and exterior of vehicles such as automobiles, home appliances and OA equipment, the body and keypad parts of mobile phones, etc. It is possible to improve the scratch resistance. Moreover, when the hard coat film which gave the lamination | stacking of the layer with printing or design property etc. beforehand is used, the design property can also be provided to a product simultaneously.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, it shows a specific example and is not specifically limited to these.
<Example 1>
Synthesis of Urethane Prepolymer Solution 1 In a 300 mL four-necked flask equipped with a stirrer, a condenser tube, a dropping funnel, and a thermometer, 16.6 parts by weight of glycerin monomethacrylate, 39.6 parts by weight of methyl ethyl ketone (MEK), 0. 1 part by weight and dibutyltin dilaurate / 0.001 part by weight were charged, and the temperature was raised to 60 ° C. Tolylene diisocyanate (TDI) · 16.9 parts by weight was dropped from the dropping funnel over 90 minutes. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane prepolymer solution 1 having a terminal hydroxyl group.

  The analysis results of the urethane prepolymer solution 1 are as follows.

Weight average molecular weight (Mw) = 11400, number average molecular weight (Mn) = 3000, dispersity (Mw / Mn) = 3.86, nonvolatile content = 46%, side chain radical polymerizable group equivalent (calculation) = 323 g / mol .
<Example 2>
Synthesis of Urethane Prepolymer Solution 2 A 300 mL four-necked flask equipped with a stirrer, a condenser tube, a dropping funnel, and a thermometer was charged with 15.8 parts by weight of glycerin monomethacrylate, 40.7 parts by weight of methyl ethyl ketone (MEK), 0. 1 part by weight and dibutyltin dilaurate / 0.001 part by weight were charged, and the temperature was raised to 60 ° C. 17.6 parts by weight of tolylene diisocyanate (TDI) was added dropwise over 90 minutes from the dropping funnel. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane prepolymer solution 2 having an isocyanate group at the end.

  The analysis results of the urethane prepolymer solution 2 are as follows.

Weight average molecular weight (Mw) = 9400, number average molecular weight (Mn) = 2700, dispersity (Mw / Mn) = 3.48, nonvolatile content = 47% side chain radical polymerizable group equivalent (calculation) = 338 g / mol.
<Example 3>
Synthesis of urethane prepolymer solution 3 In a 300 mL four-necked flask equipped with a stirrer, a condenser, a dropping funnel, and a thermometer, 8.9 parts by weight of glycerin monomethacrylate, polyethylene glycol (PEG 400) with hydroxyl groups at both ends with a number average molecular weight of 400 12.0 parts by weight, methyl ethyl ketone (MEK) 40.7 parts by weight, methoquinone 0.1 parts by weight, dibutyltin dilaurate 0.001 part by weight were charged, and the temperature was raised to 60 ° C. 17.6 parts by weight of tolylene diisocyanate (TDI) was added dropwise over 90 minutes from the dropping funnel. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane prepolymer solution 3 having an isocyanate group at the end.

  The analysis results of the urethane prepolymer solution 3 are as follows.

Weight average molecular weight (Mw) = 7100, number average molecular weight (Mn) = 3300, dispersity (Mw / Mn) = 2.18, non-volatile content = 45%, side chain radical polymerizable group equivalent (calculation) = 692 g / mol .
<Comparative Example 1>
Synthesis of Comparative Urethane Prepolymer Solution 1 In a 300 mL four-necked flask equipped with a stirrer, a condenser, a dropping funnel, and a thermometer, 9.5 parts by weight of diethylene glycol, 40.7 parts by weight of methyl ethyl ketone (MEK), 0. 1 part by weight and dibutyltin dilaurate / 0.001 part by weight were charged, and the temperature was raised to 60 ° C. 17.6 parts by weight of tolylene diisocyanate (TDI) was added dropwise over 90 minutes from the dropping funnel. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a comparative urethane prepolymer solution 1 having an isocyanate group at the end.

  The analysis results of the comparative urethane prepolymer solution 1 are as follows.

Weight average molecular weight (Mw) = 9900, number average molecular weight (Mn) = 2500, dispersity (Mw / Mn) = 3.95, non-volatile content = 42%, side chain radical polymerizable group = none.
<Example 4>
Synthesis of Urethane Acrylate Solution 4 After synthesizing the urethane prepolymer solution 1 according to Example 1, 2.8 parts by weight of acryloyloxyethyl isocyanate was subsequently added dropwise from the dropping funnel over 60 minutes. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane acrylate solution 4.

  The analysis results of the urethane acrylate solution 4 are as follows.

Weight average molecular weight (Mw) = 11800, number average molecular weight (Mn) = 3100, dispersity (Mw / Mn) = 3.81, nonvolatile content = 46%.
<Example 5>
Synthesis of Urethane Acrylate Solution 5 After synthesizing the urethane prepolymer solution 1 according to Example 1, a mixture of 15.3 parts by weight of dipentaerythritol pentaacrylate, 15.4 parts by weight of MEK, and 0.001 part by weight of dibutyltin dilaurate was collected all at once. After charging and mixing well, 1.4 parts by weight of tolylene diisocyanate (TDI) was added dropwise from the dropping funnel over 60 minutes. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane acrylate solution 5.

  The analysis results of the urethane acrylate solution 5 are as follows.

Weight average molecular weight (Mw) = 32500, number average molecular weight (Mn) = 2400, dispersity (Mw / Mn) = 13.69, non-volatile content = 47%.
<Example 6>
Synthesis of Urethane Acrylate Solution 6 After synthesizing the urethane prepolymer solution 3 according to Example 3, a mixture of 15.7 parts by weight of dipentaerythritol pentaacrylate and 19.2 parts by weight of MIBK was subsequently added dropwise over 60 minutes from the dropping funnel. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a urethane acrylate solution 6.

The analysis results of the urethane acrylate solution 6 are as follows.
Weight average molecular weight (Mw) = 7400, number average molecular weight (Mn) = 3500, dispersity (Mw / Mn) = 2.09, non-volatile content = 45%.
<Comparative example 2>
Synthesis of Comparative Urethane Acrylate Solution 2 After synthesizing comparative urethane prepolymer solution 1 according to Comparative Example 1, subsequently, a mixture of 15.7 parts by weight of dipentaerythritol pentaacrylate and 19.2 parts by weight of MIBK was added from the dropping funnel over 60 minutes. It was dripped. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours to obtain a comparative urethane acrylate solution 2.

  The analysis results of the comparative urethane acrylate solution 2 are as follows.

Weight average molecular weight (Mw) = 5300, number average molecular weight (Mn) = 2500, dispersity (Mw / Mn) = 2.12, non-volatile content = 43%.
<Examples 7 to 12, Comparative Examples 3 and 4>
Photocurable resin composition, hard coat film The urethane prepolymer solution or the urethane acrylate solution obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were blended as shown in Table 1, and the photocurable resin compositions 7 to 14 were prepared. Produced. Each composition was applied to a 125 μm thick polyethylene terephthalate film with a bar coater (No. 30) and dried in a hot air oven at 100 ° C. for 3 minutes to obtain a hard coat film having a transparent and uniform coating film. The dry film thickness was 5 μm. Tack was measured on this sample. Separately, each composition was applied to a release-treated plastic film with a dry film thickness of 50 μm, and only the film was peeled off in an uncured state, and a coating film stretch test was performed under the condition of stretching at 90 ° C. It was judged whether the film strength was sufficiently maintained by sensory evaluation under the conditions of the coating film spreading test, and the mechanical strength test was conducted.

Further, the sample was irradiated with ultraviolet rays using an ultraviolet ray curing high pressure mercury lamp 4 kW “H04-L41” (both from Eye Graphics Co., Ltd.) using an eye ultraviolet ray curing device “US2-0401”. UV intensity 110mW / cm ^2, accumulated light quantity was 3000 mJ / cm ^2. This sample was tested for pencil hardness and scratch resistance (steel wool).
Since Comparative Example 3 did not have a crosslinking point, and Comparative Example 4 also had only a terminal, both the pencil hardness test and the scratch resistance test result were not good. Examples 7-12 have good evaluation in all items, and the effect of the present invention appears.

The numbers in the table are parts by weight. “Darocur 1173” (Ciba Japan Co., Ltd.) is 2-hydroxy-2-methyl-1-phenylpropan-1-one.

Test conditions and criteria are as follows.
Tack: After drying in a 100 ° C. hot air oven, in an uncured state, quickly press the coating surfaces together strongly (over 1 second with a force of 3 kgf / cm ² or more) before the temperature drops, and quickly peel off The state of the coating film was judged visually. ◎ = No abnormality (excellent), ○ = Slightly traced (good), △ = Slight peeling, x = most peeled coating film: applied to a release film with a dry film thickness of 50 μm, Only the film is peeled off in an uncured state and stretched at 90 ° C. ◎ = No whitening or breakage even when stretched by 100% or more, ○: No whitening or breakage even when stretched by 50% or more, and whitening or breakage when stretched within 50%.
Mechanical strength: The state of the film under the conditions of the coating film spreading test condition was visually judged and indicated by ◯ ×.
Pencil hardness: measured and determined according to JIS K-5600. Load 750g.
Scratch resistance (steel wool): Rub 10 reciprocations with steel wool with a load of 1000 g and a count of # 0000, and visually check for scratches. ◎ = No scratch, ○ = 1-9 fine scratches, Δ = many thin scratches, × = many thick scratches.

<Example 13>
The hard coat film obtained in Example 10 was set in a three-dimensional mold set at 130 ° C., and then polyMMA resin was injection molded. The molded product is taken out from the mold, allowed to cool to room temperature, and then irradiated with ultraviolet ray high pressure mercury lamp 4kW “H04-L41” (both from Eye Graphics Co., Ltd.) using an eye ultraviolet ray curing device “US2-0401”. Irradiation was performed to obtain a molded product. The ultraviolet intensity was 150 mW / cm ² and the integrated light amount was 3000 mJ / cm ² . Visual observation of the molded product revealed no abnormal appearance such as cracks. When pencil hardness and scratch resistance (steel wool) were measured, good results equivalent to Example 10 in Table 1 were obtained.
<Comparative Example 5>
A molded product was obtained in the same manner as in Example 13 except that the composition 14 obtained in Comparative Example 4 was used. When the molded product was visually observed, a portion where the coating film was uneven was found. When pencil hardness and scratch resistance (steel wool) were measured, results inferior to those of Examples equivalent to Comparative Example 4 in Table 1 were obtained.

Claims (7)

A radical having a molecular structure in which at least (A) a compound having two hydroxyl groups and one radical polymerizable group in one molecule and (B) a compound having two or more isocyanate groups in one molecule are linked. A radically polymerizable group-containing urethane prepolymer, which is a polymerizable group-containing urethane prepolymer, wherein the equivalent of the side chain radically polymerizable group derived from the component (A) is 1500 g / mol or less. At least (A) a compound having two hydroxyl groups and one radical polymerizable group in one molecule, (B) a compound having two or more isocyanate groups in one molecule, and (C) in one molecule. A radically polymerizable group-containing urethane prepolymer having a molecular structure in which a compound having two hydroxyl groups and no radically polymerizable group is linked, and the side chain radically polymerizable group equivalent derived from the component (A) is A radically polymerizable group-containing urethane prepolymer of 1500 g / mol or less.   3. The urethane prepolymer according to claim 1, wherein the urethane prepolymer containing an isocyanate group in the molecule further comprises (D) a group that reacts with one isocyanate group and one or more (meth) acryloyl groups. Urethane (meth) acrylate obtained by reacting   The urethane prepolymer according to claim 1 or 2, wherein (E) a compound that reacts with one hydroxyl group and a compound that contains one or more (meth) acryloyl groups are further reacted with the urethane prepolymer containing a hydroxyl group in the molecule. Urethane (meth) acrylate.   The photocurable resin composition which contains the urethane prepolymer and / or urethane (meth) acrylate of Claims 1-4, the photoinitiator, and the organic solvent as essential.   A hard coat film obtained by coating the photocurable resin composition according to claim 5 on a plastic film.   A molded product obtained by insert molding or in-mold molding using the hard coat film according to claim 6.