JP2015124265A - Urethane (meth)acrylate compound, active energy ray curable resin composition and coating agent using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane (meth) acrylate-based compound excellent in resilience and hardness at a level that can withstand practicality when it is used as a cured coating film, and an active energy ray-curable resin composition and a coating agent using the same. To do. A urethane (meth) acrylate compound comprising a polyisocyanate compound (a1) containing two or more allophanate groups. [Selection figure] None

Description

  The present invention relates to a urethane (meth) acrylate compound, and more specifically, a urethane (meth) acrylate compound and an active energy ray-curable resin composition for forming a cured coating film excellent in resilience to scratches and surface hardness. And a coating agent using the same.

  Conventionally, urethane (meth) acrylate compounds are widely used as coating agents, adhesives, anchor coating agents, and the like on various substrates because they are cured by irradiation with an active energy ray for a very short time.

  Among them, as a coating agent, an active energy ray-curable resin composition capable of forming a cured film on the surface of a plastic substrate and forming a cured film having resilience against scratches capable of protecting the substrate. Development is desired. For example, an ultraviolet curable coating composition using a urethane acrylate oligomer obtained by reacting a polycaprolactone-containing polyfunctional alcohol, an isocyanate and a hydroxyl group-containing (meth) acrylate (see, for example, Patent Document 1). ) Has been proposed.

Japanese Patent Laid-Open No. 2004-35599

  However, in the disclosed technique of the above-mentioned Patent Document 1, the polycaprolactone-containing polyfunctional alcohol is used as a constituent material of the urethane (meth) acrylate compound, so that it exhibits some resilience when a cured coating film is obtained. Since many polycaprolactone-containing polyfunctional alcohols are used, gelation tends to occur during production.

  Therefore, the present invention has a urethane (meth) acrylate compound and an active energy ray-curable resin composition excellent in resilience and surface hardness at a level that can withstand practicality when used as a cured coating film under such a background. The object is to provide a product and a coating agent using the product.

  However, as a result of intensive studies in view of such circumstances, the present inventors have used an isocyanate compound having a plurality of allophanate groups as a polyvalent isocyanate compound as a constituent component in a urethane (meth) acrylate compound. Thus, a three-dimensional structure derived from an allophanate group or the like is formed on the cured coating film, and contains a flexible segment derived from the three-dimensional structure and a hard segment derived from a urethane bond or the like in an appropriate ratio. Since a cured coating film was obtained, it was found that a cured film having a high hardness can be obtained because of its excellent resilience to scratches and a high crosslinking density, and the present invention has been completed.

That is, the gist of the present invention relates to a urethane (meth) acrylate compound characterized by using a polyvalent isocyanate compound (a1) containing two or more allophanate groups.
Moreover, in this invention, the active energy ray-curable resin composition containing the said urethane (meth) acrylate type compound and a coating agent using the same are provided.

  The urethane (meth) acrylate compound of the present invention has an excellent effect on resilience and surface hardness against scratches when it is used as a cured coating film, and is particularly useful as a coating agent.

The present invention is described in detail below.
In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate.

First, a urethane (meth) acrylate compound characterized by using a polyvalent isocyanate compound (a1) containing two or more allophanate groups of the present invention will be described.
The ethylenically unsaturated group content (mmol / g) of the urethane (meth) acrylate compound is preferably 0.01 to 10 mmol / g, particularly preferably 0.1 to 5 mmol / g, and still more preferably. Is 1 to 3 mmol / g.
If the content of the ethylenically unsaturated group (mmol / g) of the urethane (meth) acrylate compound (X) is too small, it tends to be difficult to obtain as a cured coating film after irradiation with active energy rays. There is a tendency that the hardness is too high to obtain the restoration property.

The weight average molecular weight of the urethane (meth) acrylate compound is preferably 800 to 800,000, particularly preferably 1,000 to 100,000, and still more preferably 1,000 to 50,000.
If the weight average molecular weight is too small, sufficient resilience tends to be difficult to obtain, and if the weight average molecular weight is too large, the viscosity of the coating agent tends to be high and painting tends to be difficult.

The viscosity of the urethane (meth) acrylate compound at 60 ° C. is preferably 200 to 150,000 mPa · s, particularly 500 to 120,000 mPa · s, more preferably 1,000 to 50,000 mPa · s. It is preferable. When the viscosity is out of the above range, the coatability tends to be lowered.
The viscosity is measured with an E-type viscometer.

  The urethane (meth) acrylate compound characterized by using the polyvalent isocyanate compound (a1) containing two or more allophanate groups of the present invention is a polyvalent isocyanate compound containing two or more allophanate groups. A urethane (meth) acrylate compound (hereinafter referred to as “urethane (meth) acrylate compound (X)”) obtained by reacting a compound (a1) and a hydroxyl group-containing (meth) acrylate compound (a2) A polyisocyanate compound (a1) containing two or more allophanate groups, a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3). Urethane (meth) acrylate compounds (hereinafter referred to as “urethane (meth) acrylates” May be referred to as Relate compound (Y).) Is preferably.

"Urethane (meth) acrylate compounds (X)"
The urethane (meth) acrylate compound (X) of the present invention is obtained by reacting a polyvalent isocyanate compound (a1) containing two or more allophanate groups and a hydroxyl group-containing (meth) acrylate compound (a2). is there.

  Regarding the polyvalent isocyanate compound (a1) containing two or more of the above allophanate groups (hereinafter sometimes simply referred to as “polyvalent isocyanate compound (a1)”), the number of allophanate groups is two or more. It is necessary to be, preferably 2 to 6, particularly preferably 2 to 4, and more preferably 2. If the content is too small, it is difficult to obtain restorability and sufficient surface hardness. If the content is too large, the number of isocyanate groups in the molecule increases, and gelation tends to occur during production.

  Further, the number of isocyanate groups in the polyvalent isocyanate compound (a1) needs to be 2 or more, preferably 2 to 8, particularly preferably 4 to 6, and further preferably 4. . If the content is too small, it is difficult to obtain restorability and sufficient surface hardness, and if it is too large, gelation tends to occur during production.

  The polyvalent isocyanate compound (a1) of the present invention is a flexible molecule that is obtained by reacting a polyvalent isocyanate compound (a1-1) with a hydroxyl group-containing compound (a1-2). The structure is preferable in that the structure can be appropriately introduced. Particularly, the following general formula (1) obtained by reacting the polyvalent isocyanate compound (a1-1) and the diol (a1-2-1), the polyvalent isocyanate compound (a1) -1) and monool (a1-2-2) are particularly preferably represented by the following general formula (2).

（式中、Ｒ_１は多価イソシアネート系化合物（ａ１−１）のアロファネート結合残基、Ｒ_２はジオール（ａ１−２−１）のアロファネート結合残基、ｎは１〜１０の整数である。）

(In the formula, R ₁ is an allophanate binding residue of the polyvalent isocyanate compound (a1-1), R ₂ is an allophanate binding residue of the diol (a1-2-1), and n is an integer of 1 to 10. )

  N in the said General formula (1) is an integer of 1-10, Preferably it is 1-3, Most preferably, it is 1-2. If the value of n is too small, there is a tendency that a three-dimensional structure due to allophanate groups cannot be formed and it is difficult to obtain restorability, and if it is too large, gelation tends to occur during production.

（式中、Ｒ_１は多価イソシアネート系化合物（ａ１−１）のアロファネート結合残基、Ｒ_２はモノオール（ａ１−２−２）のアロファネート結合残基、ｎは１以上の整数である。）

(In the formula, R ₁ is an allophanate binding residue of the polyisocyanate compound (a1-1), R ₂ is an allophanate binding residue of the monool (a1-2-2), and n is an integer of 1 or more. )

  N in the general formula (2) is an integer of 1 or more, preferably 1 to 10, particularly preferably 1 to 3. If the value of n is too small, the restoring property tends to be difficult to obtain, and if it is too large, gelation tends to occur during production.

  Examples of the polyvalent isocyanate compound (a1-1) include tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Aromatic polyisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate and other aliphatic polyisocyanates, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1, 3-bis (isocyanatomethi ) Cycloaliphatic polyisocyanates such as cyclohexane, trimer compounds or multimeric compounds of these polyisocyanates, allophanate polyisocyanates containing one allophanate bond, burette polyisocyanates, water-dispersed polyisocyanates (for example, "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210", etc.) manufactured by Nippon Polyurethane Industry Co., Ltd.).

  Among these, it is preferable to use an aliphatic polyisocyanate and an alicyclic polyisocyanate, and hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and isophorone diisocyanate are particularly preferable in that there is no coloring of a paint or a coating agent. Hexamethylene diisocyanate is more preferable from the viewpoint of balance of surface hardness.

  The hydroxyl group-containing compound (a1-2) may be a compound having one or more alcoholic hydroxyl groups in one molecule, such as diol (a1-2-1) or monool (a1-2-2). ) And alcohols containing 3 or more hydroxyl groups, among which diol (a1-2-1) and monool (a1-2-2) are preferred from the viewpoint of stable production.

  Examples of the diol (a1-2-1) include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol. 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, 2,2 -Dimethylol heptane, trimethylene glycol, 1,4-tetramethylene glycol, dipropylene glycol, 1,3-tetramethylene diol, 2-methyl-1,3-trimethylene diol, 2,4-diethyl-1,5 -Pentamethylenediol, hydrogenated bisphenol A, hydroxyal Bisphenol A, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 2,2,4-trimethyl-1,3-pentanediol, N, N-bis- (2-hydroxyethyl) dimethylhydantoin, etc. Low molecular weight diols; hydroxyl groups such as polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, (meth) acrylic polyols, polycaprolactone polyols, polysiloxane polyols, polyurethane polyols, etc. Are included.

  Examples of the polyether polyol include oxyalkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol, and random or block copolymer of these polyalkylene glycols. Coalescence is mentioned.

  Among these, an oxyalkylene structure-containing polyether polyol is preferable, and the number of carbon atoms of the alkylene structure is preferably 2 to 6, particularly preferably 2 to 4, and more preferably 4.

Examples of the polyester-based polyol include a condensation polymer of a polyhydric alcohol and a polycarboxylic acid; a ring-opening polymer of a cyclic ester (lactone); a polyhydric alcohol, a polycarboxylic acid, and a cyclic ester. And reactants.
Examples of the polyhydric alcohol include the low molecular weight diol.
Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; -Cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylene dicarboxylic acid, trimellitic acid, and the like.
Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone.

Examples of the polycarbonate polyol include a reaction product of a polyhydric alcohol and phosgene; a transesterification product of a carbonate ester and a polyhydric alcohol, and the like.
Examples of the polyhydric alcohol include the low molecular weight diols, and examples of the alkylene carbonate include ethylene carbonate, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and the like. Examples include diphenyl carbonate.
The polycarbonate-based polyol may be a compound having a carbonate bond in the molecule and a terminal being a hydroxyl group, and may have an ester bond together with the carbonate bond.

  Examples of the polyolefin-based polyol include those having a saturated hydrocarbon skeleton having a homopolymer or copolymer such as ethylene, propylene and butene, and having a hydroxyl group at the molecular end.

Examples of the polybutadiene-based polyol include those having a butadiene copolymer as a hydrocarbon skeleton and having a hydroxyl group at the molecular end.
The polybutadiene-based polyol may be a hydrogenated polybutadiene-based polyol in which all or part of the ethylenically unsaturated groups contained in the structure is hydrogenated.

  Examples of the (meth) acrylic polyol include those having at least two hydroxyl groups in the molecule of the polymer or copolymer of the (meth) acrylic acid ester. , For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid Examples include 2-ethylhexyl, (meth) acrylic acid decyl, (meth) acrylic acid dodecyl, (meth) acrylic acid alkyl esters such as octadecyl (meth) acrylic acid, and the like.

  Examples of polycaprolactone-based polyols include ε-caprolactone adducts of polyhydric alcohols.

  Examples of the polysiloxane polyol include dimethyl polysiloxane polyol and methylphenyl polysiloxane polyol.

  Examples of the polyurethane polyol include a reaction product of a polyvalent isocyanate compound and a polyol compound.

  Among these diols (a1-2-1), polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polycaprolactone polyols, polysiloxane polyols, and polyurethane polyols are preferable, and particularly preferably obtained. The polyether-based polyol and the polycarbonate-based polyol are used in that the cured coating film is excellent in balance between resilience and surface hardness.

  The monool (a1-2-2) may be any monool containing one alcoholic hydroxyl group. For example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, pen Examples thereof include monools having 1 to 18 carbon atoms such as tanol, lauryl alcohol, myristyl alcohol, stearyl alcohol, oleyl alcohol, and linoleyl alcohol.

  In addition to monools, (meth) acrylate compounds containing one hydroxyl group can also be mentioned. Examples of (meth) acrylate compounds containing one hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2 -Hydroxypropyl (meth) acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl acrylate, 10-hydroxy Hydroxyalkyl (meth) acrylates having an alkylene chain of 2 to 16 carbon atoms such as decyl acrylate, 12-hydroxydodecyl acrylate, 14-hydroxytetradecyl acrylate, 16-hydroxyhexadecyl acrylate Etc. The.

  In addition, about the alcohol containing 3 or more of the said hydroxyl groups, since it is easy to gelatinize at the time of manufacture of a polyvalent isocyanate type compound (a1), you may use a suitable quantity in the range which does not impair the effect of this invention.

The weight average molecular weight of the hydroxyl group-containing compound (a1-2) is preferably 32 to 10,000, particularly preferably 350 to 2,000, and further preferably 500 to 1,000.
If it is too large, the surface hardness of the coating film tends to decrease, and if it is too small, sufficient resilience tends not to be obtained.

  As a method for producing the polyvalent isocyanate compound (a1) containing two or more allophanate groups, the polyvalent isocyanate compound (a1-1) and the hydroxyl group-containing compound (a1-2) are used, and the isocyanate group is excessive with respect to the hydroxyl group. In the presence of an allophanatization catalyst at 70 to 150 ° C. until all urethane groups are substantially absent, thin film distillation, etc. And a method for removing unreacted polyvalent isocyanate compounds.

  The amount by which the isocyanate group is excessive with respect to the hydroxyl group is preferably such that the molar ratio of isocyanate group to hydroxyl group is isocyanate group / hydroxyl group = 8 or more, particularly preferably isocyanate group / hydroxyl group = 10-50.

  The reaction temperature of the urethanization reaction is preferably 20 to 120 ° C, particularly preferably 50 to 100 ° C. In the urethanization reaction, a known so-called urethanization catalyst can be used, and examples thereof include organic metal compounds such as dibutyltin dilaurate and dioctyltin dilaurate, organic amines such as triethylenediamine and triethylamine, and salts thereof. .

  The reaction time of the urethanization reaction varies depending on the presence or absence of the catalyst, the type thereof, and the reaction temperature, but generally it is preferably within 10 hours, particularly preferably 1 to 5 hours.

  When the urethanization reaction is completed, an allophanatization reaction is performed. The reaction temperature of the allophanatization reaction is 70 to 150 ° C, preferably 80 to 130 ° C. In the allophanatization reaction, a known so-called allophanatization catalyst can be used. Specific examples of the catalyst include zirconium carboxylate, zirconyl carboxylate, and tin (divalent) carboxylate. Etc.

In the present invention, the urethanization reaction and the allophanatization reaction can be performed simultaneously. In this case, the polyvalent isocyanate compound (a1-1) and the hydroxyl group-containing compound (a1-2) are charged in an amount that makes the isocyanate group excessive with respect to the hydroxyl group, and the allophanate catalyst at 70 to 150 ° C. In the presence, the urethanization reaction and the allophanatization reaction are performed simultaneously.

  The amount of the allophanatization catalyst used varies depending on the type, but is preferably 0.0005 to 1% by weight, preferably 0.001 to 0.1%, based on the total amount of the above (a1-1) and (a1-2). Weight percent is more preferred. If the amount of the catalyst used is too small, the reaction is substantially delayed and a long time is required, and coloration due to heat history tends to occur. If the amount is too large, problems such as difficulty in controlling the reaction tend to occur.

  The reaction time varies depending on the type of catalyst, the amount added, and the reaction temperature, but is usually within 10 hours, preferably 1 to 5 hours.

  After the allophanatization reaction, a catalyst poison is added to stop the allophanate reaction. There is no particular limitation on the timing of addition of the catalyst poison as long as it is after the allophanatization reaction, but when thin film distillation is used as a method for removing free organic diisocyanate, the catalyst poison is added after the allophanate reaction and before thin film distillation. It is preferable to add. This is to prevent side reactions from occurring due to heat during thin film distillation.

  As the catalyst poison, known acids such as inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having a sulfonic acid group, a sulfamic acid group and the like, esters thereof, acyl halides and the like can be used.

  The addition amount of the catalyst poison varies depending on the type and the type of the catalyst, but an amount that is 0.5 to 2 equivalents of the catalyst is preferable, and 0.8 to 1.5 equivalents is particularly preferable. When there is too little catalyst poison, the storage stability of the polyisocyanate obtained tends to fall. When there are too many, the obtained polyisocyanate may color.

  In the present invention, a free polyvalent isocyanate compound is basically present in the product after the allophanatization reaction. Since this free polyisocyanate compound inhibits the formation of a three-dimensional structure by the allophanate group, unreacted polyisocyanate system is used until the content of the free polyisocyanate compound is 1% by weight or less. It is preferred to remove the compound.

  Examples of a method for removing the free polyvalent isocyanate compound (a1-1) include known methods such as distillation, reprecipitation, and extraction. Distillation, particularly thin-film distillation, is preferable because a solvent or the like can be used. Further, preferable conditions for thin film distillation are pressure: 0.1 kPa or less, temperature: 100 to 200 ° C., and particularly preferable conditions are pressure: 0.05 kPa or less and temperature: 120 to 180 ° C.

  Specifically, as the polyvalent isocyanate compound (a1) containing two or more allophanate groups of the present invention, a polyvalent isocyanate compound obtained by reacting hexamethylene diisocyanate and a polyether polyol, isophorone diisocyanate and polyether Polyisocyanate compound obtained by reacting a polyol based on polyisocyanate, polyisocyanate compound obtained by reacting hexamethylene diisocyanate with a polycarbonate diol, polyisocyanate compound obtained by reacting isophorone diisocyanate with a polycarbonate diol , A polyvalent isocyanate compound obtained by reacting hexamethylene diisocyanate and caprolactone-modified trimethylolpropane, hexamethylene diisocyanate and 2-hydride Examples include polyisocyanate compounds obtained by reacting xylethyl acrylate, preferably allophanate-containing polyisocyanates obtained by reacting hexamethylene diisocyanate and polytetramethylene ether glycol, hexamethylene diisocyanate and polycarbonate diol. It is an allophanate-containing polyisocyanate obtained by reaction.

  The weight average molecular weight of the polyvalent isocyanate compound (a1) is preferably 350 to 10,000, particularly preferably 500 to 5,000, and further preferably 700 to 3,000. If the weight average molecular weight is too large, the viscosity of the coating agent tends to be high and painting tends to be difficult. If the weight average molecular weight is too small, sufficient resilience cannot be obtained.

Examples of the hydroxyl group-containing (meth) acrylate compound (a2) in the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl. C2-C6 hydroxyalkyl (meth) acrylate such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate , Caprolactone modified 2-hydroxyethyl (meth) acrylate, dipropylene glycol mono (meth) acrylate, fatty acid modified glycidyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, poly Propylene glycol mono (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxy propyl (meth) hydroxyl group-containing (meth) acrylate compound containing one ethylenically unsaturated group such as acrylate;
Glycerin di (meth) acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate, pentaerythritol tri (meth) acrylate, caprolactone modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, dipenta Hydroxyl group-containing (meth) acrylate compounds containing two or more ethylenically unsaturated groups such as erythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, and ethylene oxide-modified dipentaerythritol penta (meth) acrylate These can be used, and these can be used alone or in combination of two or more.

  Among these, it is preferable to have a hydroxyl group (meth) acrylate compound containing one ethylenically unsaturated group, and in terms of excellent reactivity and versatility, 2-hydroxyethyl (meth) acrylate, 2 -Hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, more preferably hydroxyalkyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferred.

  The urethane (meth) acrylate compound (X) is obtained by reacting the polyvalent isocyanate compound (a1) with the hydroxyl group-containing (meth) acrylate compound (a2). What is necessary is just to manufacture according to the manufacturing method of this urethane (meth) acrylate type compound. For example, the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2) may be charged into the reactor or reacted separately.

  The reaction molar ratio between the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2) is, for example, that the polyisocyanate compound has four isocyanate groups, and the hydroxyl group-containing (meth) acrylate. (A1) :( a2) is about 1: 4-5, the polyisocyanate compound has 6 isocyanate groups, and the hydroxyl group-containing (meth) acrylate compound When there is one hydroxyl group, (a1) :( a2) is about 1: 6-7.

  In the addition reaction of the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), the reaction is completed when the residual isocyanate group content in the reaction system is 0.5% by weight or less. By making it, urethane (meth) acrylate type compound (X) is obtained.

  In the reaction between the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), it is also preferable to use a catalyst for the purpose of accelerating the reaction. Examples of such a catalyst include dibutyltin dilaurate. , Dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, bis (acetylacetonato) zinc, bis (tetrafluoroacetylacetonato) zinc, zirconium monoacetylacetonate, zirconium ethylacetoacetate, zirconium tris ( Acetylacetonate) ethyl acetoacetate, zirconium tetraacetylacetonate, tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium and other organometallic compounds, tin octenoate, Zinc xanthate, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannic chloride, potassium acetate and other metal salts, triethylamine, triethylenediamine, benzyldiethylamine, 1, 4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N-methylmorpholine In addition to amine-based catalysts such as N-ethylmorpholine, bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, etc., organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate, and bismuth 2-ethylhexanoate, Bismuth naphthenate, bismuth isodecanoate, neodecane Bismuth salt, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bisneodecanoate, bismuth disalicylate, bismuth digallate, etc. Examples include bismuth-based catalysts such as organic acid bismuth salts, among which dibutyltin dilaurate and 1,8-diazabicyclo [5,4,0] undecene are preferred. These can be used alone or in combination of two or more.

  In the reaction of the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), an organic solvent having no functional group that reacts with an isocyanate group, such as methyl acetate, ethyl acetate, Organic solvents such as esters such as butyl acetate, 2-ethoxyethyl acetate and 2-methoxy-1-methylethyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatics such as toluene and xylene can be used. .

  The reaction temperature is usually 30 to 100 ° C., preferably 40 to 90 ° C., and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

The number of ethylenically unsaturated groups contained in the urethane (meth) acrylate compound (X) obtained above is preferably 2 to 30, particularly preferably 4 to 10, and more preferably 4 to 6. It is.
If the number of ethylenically unsaturated groups is too small, the hardness of the coating film tends not to be obtained, while if too large, the hardness of the coating film is too high and it is difficult to obtain restorability.

The ethylenically unsaturated group content (mmol / g) of the urethane (meth) acrylate compound (X) is preferably 0.01 to 10 mmol / g, particularly preferably 0.1 to 5 mmol / g. More preferably, it is 1-3 mmol / g.
If the content of the ethylenically unsaturated group (mmol / g) of the urethane (meth) acrylate compound (X) is too small, it tends to be difficult to obtain as a cured coating film after irradiation with active energy rays. There is a tendency that the hardness is too high to obtain the restoration property.

The weight average molecular weight of the urethane (meth) acrylate compound (X) is preferably 800 to 100,000, particularly preferably 1,000 to 10,000, and more preferably 1,000 to 5,000. .
If the weight average molecular weight is too small, sufficient resilience tends to be difficult to obtain, and if the weight average molecular weight is too large, the viscosity of the coating agent tends to increase and coating tends to be difficult.

The viscosity of the urethane (meth) acrylate compound (X) at 60 ° C. is preferably 200 to 150,000 mPa · s, particularly 500 to 50,000 mPa · s, more preferably 1,000 to 10,000 mPa · s. It is preferable that it is s. When the viscosity is out of the above range, the coatability tends to be lowered.
The viscosity is measured with an E-type viscometer.

  [Urethane (meth) acrylate compound (Y)]

  The urethane (meth) acrylate compound (Y) of the present invention includes a polyvalent isocyanate compound (a1) containing two or more allophanate groups, a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3). ).

  (A1) and (a2) forming the urethane (meth) acrylate compound (Y) are the same as (a1) and (a2) in the description of the urethane (meth) acrylate compound (X) described above. is there.

  The polyol compound (a3) may be, for example, the same as the diol (a1-2-1) described above, preferably a low molecular weight diol, a polyether polyol, or a polycarbonate polyol, particularly preferably. Are polyether polyols and polycarbonate polyols.

  The method for producing the urethane (meth) acrylate compound (Y) is usually a batch of the polyisocyanate compound (a1), the hydroxyl group-containing (meth) acrylate compound (a2), and the polyol compound (a3) in a reactor. The polyol compound (a3) may be added to the reaction product obtained by reacting the polyvalent isocyanate compound (a1) with the hydroxyl group-containing (meth) acrylate compound (a2) in advance. The reaction is useful in terms of the stability of the reaction.

  For the reaction of the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), known reaction means can be used. At that time, for example, the functional group molar ratio of the isocyanate group in the polyvalent isocyanate compound (a1) to the hydroxyl group in the hydroxyl group-containing (meth) acrylate compound (a2) is usually determined as follows: After obtaining a terminal isocyanate group-containing urethane (meth) acrylate-based compound in which an isocyanate group remains, by adding a hydroxyl group of (meth) acrylate to a hydroxyl group of polyol), an addition reaction with a polyol-based compound (a3) Enable. In the addition reaction, the urethane (meth) acrylate compound (Y) is obtained by terminating the reaction when the residual isocyanate group content in the reaction system becomes 0.5% by weight or less.

  In the reaction between the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), and further the reaction product and the polyol compound (a3), a catalyst is used for the purpose of promoting the reaction. As such a catalyst, for example, the same catalyst as that exemplified in the production examples of the urethane (meth) acrylate compound (X) may be used.

  In the reaction between the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), and further in the reaction between the reaction product and the polyol compound (a3), it reacts with an isocyanate group. Organic solvents having no functional group, for example, esters such as methyl acetate, ethyl acetate, butyl acetate, 2-ethoxyethyl acetate, 2-methoxy-1-methylethyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, toluene Organic solvents such as aromatics such as xylene can be used.

  The reaction temperature is usually 30 to 100 ° C., preferably 40 to 90 ° C., and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

The number of ethylenically unsaturated groups contained in the urethane (meth) acrylate compound (Y) obtained above is preferably 2 to 30, particularly preferably 4 to 10, and more preferably 4 to 6. It is.
When the number of ethylenically unsaturated groups is too small, the hardness of the coating film tends to decrease, and when too large, the hardness of the coating film is too high and it is difficult to obtain restorability.

The ethylenically unsaturated group content (mmol / g) of the urethane (meth) acrylate compound (Y) is preferably 0.01 to 10 mmol / g, particularly preferably 0.1 to 5 mmol / g. More preferably, it is 1-3 mmol / g.
If the content of the ethylenically unsaturated group (mmol / g) of the urethane (meth) acrylate compound (Y) is too small, it tends to be difficult to obtain as a cured coating film after irradiation with active energy rays. There is a tendency that the hardness is too high to obtain the restoration property.

The weight average molecular weight of the urethane (meth) acrylate compound (Y) is preferably 1,000 to 800,000, particularly preferably 2,000 to 100,000, and more preferably 3,000 to 50,000. It is.
If the weight average molecular weight is too small, sufficient resilience tends to be difficult to obtain, and if the weight average molecular weight is too large, the viscosity of the coating agent tends to increase and coating tends to be difficult.

The viscosity of the urethane (meth) acrylate compound (Y) at 60 ° C. is preferably 200 to 150,000 mPa · s, particularly 2,000 to 120,000 mPa · s, more preferably 5,000 to 50,000. mPa · s is preferable. When the viscosity is out of the above range, the coatability tends to be lowered.
The viscosity is measured with an E-type viscometer.

  Thus, the urethane (meth) acrylate compound ((X) and / or (Y)) used in the present invention can be produced.

  In this invention, it is preferable to set it as the active energy ray-curable resin composition containing this urethane (meth) acrylate type compound ((X) and / or (Y)).

  In this active energy ray-curable resin composition, if necessary, an ethylenically unsaturated compound other than the photopolymerization initiator (B) and the urethane (meth) acrylate-based compound ((X) and / or (Y)). (C), polymers such as acrylic resins, surface conditioners, leveling agents, polymerization inhibitors, etc. can be added, and further dyes, pigments, oils, plasticizers, waxes, desiccants, dispersants, wetting agents , Emulsifiers, gelling agents, antioxidants, flame retardants, antistatic agents, electrolyte salts, fillers, stabilizers, reinforcing agents, matting agents, cross-linking agents, UV absorbers, weathering agents, light stabilizers, thickening An agent, a rust inhibitor, an adhesion improver, a film-forming aid, an abrasive, organic fine particles, inorganic particles, and the like can also be blended.

  Examples of the photopolymerization initiator (B) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4- Acetophenones such as morpholinophenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl Benzo such as ether Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium Benzophenones such as chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy ) -3, -Thioxanthones such as dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentyl Acylphosphine oxides such as phosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, as for these photoinitiators (B), only 1 type may be used independently and 2 or more types may be used together.

  These auxiliary agents include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid. Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. can be used in combination.

  Among these, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoyl isopropyl ether, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- It is preferable to use phenylpropan-1-one.

As content of a photoinitiator (B), when using urethane (meth) acrylate type compound ((X) and / or (Y)) and the below-mentioned ethylenically unsaturated monomer (C), it was also included. The amount is preferably 0.1 to 20 parts by weight, particularly preferably 0.5 to 10 parts by weight, and more preferably 1 to 5 parts by weight with respect to the total amount of 100 parts by weight.
If the content of the photopolymerization initiator (B) is too small, curing tends to be poor and film formation tends to be difficult, and if too large, yellowing of the cured coating tends to occur, and coloring problems tend to occur.

  Examples of the ethylenically unsaturated compounds [excluding urethane (meth) acrylate compounds (X) and (Y)] (C) include, for example, urethane (meth) acrylate compounds (C1) and / or ethylenically unsaturated monomers (C2) is preferred.

  The urethane (meth) acrylate compound (C1) is also required to be a urethane (meth) acrylate compound (C1-1) represented by the following general formula (3) even when used for various purposes. It is preferable in that it is easy to impart physical properties.

（式中、Ｒ₁は多価イソシアネート系化合物のウレタン結合残基、Ｒ₂は水酸基含有（メタ）アクリレート系化合物のウレタン結合残基、ａは２〜１０の整数である。）

(In the formula, R ₁ is a urethane bond residue of a polyvalent isocyanate compound, R ₂ is a urethane bond residue of a hydroxyl group-containing (meth) acrylate compound, and a is an integer of 2 to 10).

  The urethane (meth) acrylate (C1-1) represented by the general formula (3) (hereinafter sometimes abbreviated as “urethane (meth) acrylate-based compound (C1-1)”) is a polyvalent isocyanate-based compound. And a hydroxyl group-containing (meth) acrylate compound.

  A in general formula (3) may be an integer of 2 to 10, preferably 2 to 6, particularly preferably 2 to 3.

  Examples of such a polyvalent isocyanate compound are the same as those exemplified as the polyvalent isocyanate compound (a1-1) in the description of the urethane (meth) acrylate (X), or a polyvalent isocyanate. What reacted the type | system | group compound (a1-1) and the hydroxyl-containing compound (a1-2) is mentioned.

  Examples of such a hydroxyl group-containing (meth) acrylate compound include those exemplified as the hydroxyl group-containing (meth) acrylate compound (a2) in the description of the urethane (meth) acrylate (X). It is done.

  What is necessary is just to manufacture the manufacturing method of a urethane (meth) acrylate type compound (C1-1) according to the manufacturing method of a well-known general urethane (meth) acrylate type compound.

The number of ethylenically unsaturated groups contained in the urethane (meth) acrylate compound (C1-1) is preferably 2-30, particularly preferably 2-15, and more preferably 2-6. is there.
If the number of ethylenically unsaturated groups is too small, there is a tendency that the hardness and scratch resistance of the coating film cannot be obtained. If the number is too large, the curing shrinkage of the coating film increases and the adhesion to the substrate decreases, or the coating film becomes brittle. There is a tendency to become.

  The weight average molecular weight of the urethane (meth) acrylate compound (C1) is preferably 400 to 800,000, more preferably 800 to 50,000, and particularly preferably 1000 to 10,000. If the weight average molecular weight is too small, it tends to be difficult to maintain a balance between coating film hardness and shrinkage resistance, and if the weight average molecular weight is too large, it is difficult to maintain scratch resistance and hardness. Tend to be.

The viscosity of the urethane (meth) acrylate compound (C1) at 60 ° C. is preferably 200 to 150,000 mPa · s, particularly 500 to 120,000 mPa · s, more preferably 1,000 to 50,000 mPa · s. It is preferable that it is s. When the viscosity is out of the above range, the coatability tends to be lowered.
The viscosity is measured with an E-type viscometer.

  The ethylenically unsaturated monomer (C2) may be an ethylenically unsaturated monomer having one or more ethylenically unsaturated groups in one molecule (excluding the urethane (meth) acrylate compound (C1)). For example, a monofunctional monomer, a bifunctional monomer, a trifunctional or higher monomer may be used.

  The monofunctional monomer may be any monomer containing one ethylenically unsaturated group, such as styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, acrylonitrile. , Vinyl acetate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerol mono (meth) acrylate, glycidyl ( Acrylate), lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) ) Acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) ) Acrylate, phenol ethylene oxide modified (meth) acrylate, nonylphenol propylene oxide modified (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxy Half ester (meth) acrylate of phthalic acid derivatives such as propyl phthalate, furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine , 2-hydroxyethylacrylamide, N-methylol (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2- (meth) acryloyloxyethyl acid phosphate monoester, and the like.

  In addition to the monofunctional monomer, there may be mentioned a Michael adduct of acrylic acid or 2-acryloyloxyethyldicarboxylic acid monoester. Examples of the acrylic acid Michael adduct include acrylic acid dimer, methacrylic acid dimer, and acrylic acid trimer. Methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer and the like. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester which is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned.

  The bifunctional monomer may be any monomer containing two ethylenically unsaturated groups. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol Di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide Modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,6-hexanediol ethylene oxide modified di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) Examples include acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and 2- (meth) acryloyloxyethyl acid phosphate diester.

  The tri- or higher functional monomer may be any monomer containing three or more ethylenically unsaturated groups. For example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, Isocyanuric acid ethylene oxide modified triacrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified dipenta Thritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol tetra (meth) acrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) Examples include acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tetra (meth) acrylate, and succinic acid-modified pentaerythritol tri (meth) acrylate.

  These ethylenically unsaturated monomers (C2) may be used alone or in combination of two or more.

  As the ethylenically unsaturated compound (C), the content ratio (weight ratio) of (C1) and (C2) when the urethane (meth) acrylate compound (C1) and the ethylenically unsaturated monomer (C2) are used in combination. (C1) :( C2) = 5: 95 to 95: 5 is preferable, and (C1) :( C2) = 20: 80 to 80:20 is particularly preferable.

  It does not specifically limit as a surface conditioning agent, For example, a cellulose resin, an alkyd resin, etc. can be mentioned. Such a cellulose resin has an action of improving the surface smoothness of the coating film, and an alkyd resin has an action of imparting a film-forming property at the time of coating.

  As the leveling agent, a known general leveling agent can be used as long as it has a wettability imparting action to the base material of the coating liquid and a surface tension reducing action. For example, a silicone-modified resin, a fluorine-modified resin, An alkyl-modified resin or the like can be used.

  Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, hydroquinone monomethyl ether, mono-t- Examples thereof include butyl hydroquinone and pt-butyl catechol.

  Moreover, it is also preferable to use the organic solvent for dilution for the active energy ray curable resin composition of this invention as needed, in order to make the viscosity at the time of coating appropriate. Examples of the organic solvent include alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol and isobutanol, ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, and cellosolve such as ethyl cellosolve. , Aromatics such as toluene and xylene, glycol ethers such as propylene glycol monomethyl ether, acetates such as methyl acetate, ethyl acetate, butyl acetate and 2-methoxy-1-methylethyl acetate, diacetone alcohol, tetrahydrofuran Etc. These organic solvents may be used alone or in combination of two or more.

  In addition, in manufacturing the active energy ray-curable resin composition of the present invention, the method of mixing the urethane (meth) acrylate compound ((X) and / or (Y)) and other components is particularly limited. They can be mixed by various methods.

  The active energy ray-curable resin composition of the present invention is effectively used as a curable resin composition for coating film formation, such as a topcoat agent and an anchor coat agent on various substrates, and is active energy ray-curable. After applying the functional resin composition to the substrate (after drying further when the composition diluted with the organic solvent is applied), it is cured by irradiating with active energy rays.

  As a base material to which the active energy ray-curable resin composition of the present invention is applied, a polyolefin resin, a polyester resin, a polycarbonate resin, an acrylic resin, an acrylonitrile butadiene styrene copolymer (ABS), Plastic base materials such as polystyrene resins, cellulose resins, etc. and their molded products (films, sheets, cups, etc.), composite base materials thereof, or composite base materials of the above materials mixed with glass fibers or inorganic materials, etc. Examples include metals (aluminum, copper, iron, SUS, zinc, magnesium, alloys thereof, and the like), and substrates having a primer layer on a substrate such as glass.

  Examples of the coating method of the active energy ray-curable resin composition include wet coating methods such as spraying, showering, dipping, roll, spinning, screen printing, etc. You just apply to.

  In addition, the active energy ray-curable resin composition of the present invention can be used without a solvent, but when using the above organic solvent, it is diluted so that the solid concentration is usually 10 to 90% by weight. It is preferable to work.

  As drying conditions when diluted with the organic solvent, the temperature is usually 40 to 120 ° C. (preferably 50 to 100 ° C.), and the drying time is usually 1 to 20 minutes (preferably 2 to 10 minutes). If it is.

  Active energy rays used for curing the active energy ray-curable resin composition coated on the substrate include rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, and electromagnetic waves such as X-rays and γ rays. In addition, electron beams, proton beams, neutron beams, and the like can be used, but curing by ultraviolet irradiation is advantageous from the viewpoint of curing speed, availability of an irradiation device, price, and the like. In addition, when performing electron beam irradiation, it can harden | cure even without using a photoinitiator (B).

When curing by ultraviolet irradiation, using a high-pressure mercury lamp emitting ultra-high pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, electrodeless discharge lamp, LED, etc. Usually, ultraviolet rays of 30 to 3000 mJ / cm 2 (preferably 100 to 1500 mJ / cm 2) may be irradiated.
After UV irradiation, heating can be performed as necessary to complete curing.

  The coating thickness (thickness after curing) is related to the flaw depth assumed as the flaw resilience, so if the flaw depth does not exceed the coating thickness, In general, in view of light transmission so that the photopolymerization initiator can react uniformly as an ultraviolet curable coating film, it may be 3 to 3000 μm, preferably 5 to 500 μm, and particularly preferably 10 to 50 μm. .

  An active energy ray-curable resin composition comprising a urethane (meth) acrylate compound characterized by comprising a polyvalent isocyanate compound (a1) containing two or more allophanate groups of the present invention The product has an excellent effect on the resilience against scratches and the surface hardness when it is used as a cured coating film, and is particularly useful as a coating material, ink, coating agent, especially as a coating agent for the outermost surface.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “parts” and “%” mean weight basis.

  The following were prepared as urethane (meth) acrylate compounds (X) (see Table 1).

<Example 1: Urethane (meth) acrylate-based compound (X-1)>
Polyisocyanate system containing two allophanate groups obtained by reacting hexamethylene diisocyanate (a1-1) and polycarbonate polyol (a1-2-1) in a flask equipped with a thermometer, stirrer and water-cooled condenser Hydroquinone as a polymerization inhibitor was charged with 728.3 g (0.58 mol) of compound (a1) (isocyanate group content 13.5%) and 271.7 g (2.34 mol) of 2-hydroxyethyl acrylate (a2). 0.1 g of methyl ether and 0.05 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 60 ° C. for 6 hours. When the residual isocyanate group became 0.3% or less, the reaction was terminated, and urethane (meth) acrylate type Compound (X-1) (weight average molecular weight (Mw) 3,500, viscosity 5,700 m a · s / 60 ℃, ethylenically unsaturated group content 2.34 mmol / g) was obtained.

<Example 2: Urethane (meth) acrylate compound (X-2)>
Polyvalent isocyanate containing two allophanate groups obtained by reacting hexamethylene diisocyanate (a1-1) and polyether polyol (a1-2-1) in a flask equipped with a thermometer, stirrer and water-cooled condenser A compound (a1) (isocyanate group content 16.2%) 665.9 g (0.64 mole) and 2-hydroxypropyl acrylate (a2) 334.1 g (2.57 mole) were charged as a polymerization inhibitor. 0.1 g of hydroquinone methyl ether and 0.05 g of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60 ° C. for 6 hours. When the residual isocyanate group became 0.3% or less, the reaction was terminated, and urethane (meth) acrylate Compound (X-2) (weight average molecular weight (Mw) 4,900, viscosity 5,800 mP · S / 60 ℃, to obtain an ethylenically unsaturated group content 2.57 mmol / g).

<Example 3: Urethane (meth) acrylate-based compound (X-3)>
Polyvalent isocyanate containing two allophanate groups obtained by reacting hexamethylene diisocyanate (a1-1) and polyether polyol (a1-2-1) in a flask equipped with a thermometer, stirrer and water-cooled condenser System compound (a1) (isocyanate group content 16.2%) 429.9 g (0.41 mol) and caprolactone-modified 2-hydroxyethyl acrylate (a2) 570.1 g (1.66 mol) were charged to inhibit polymerization. 0.1 g of hydroquinone methyl ether as an agent and 0.05 g of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60 ° C. for 6 hours. When the residual isocyanate group became 0.3% or less, the reaction was terminated. ) Acrylate compound (X-3) (weight average molecular weight (Mw) 8,200, viscosity 3,100mPa · s / 60 ℃, ethylenically unsaturated group content 1.66 mmol / g) was obtained.

<Example 4: Urethane (meth) acrylate compound (X-4)>
Multivalent containing two allophanate groups obtained by reacting hexamethylene diisocyanate (a1-1) and 2-hydroxyethyl acrylate (a1-2-2) in a flask equipped with a thermometer, stirrer and water-cooled condenser Isocyanate compound (a1) [a mixture of a polyvalent isocyanate containing two or more allophanate groups and a polyvalent isocyanate containing one allophanate group (isocyanate group content 15.0%)]) 707.0 g (1.26 Mol) and 293.0 g (2.52 mol) of 2-hydroxyethyl acrylate (a2), 0.1 g of hydroquinone methyl ether as a polymerization inhibitor, 0.05 g of dibutyltin dilaurate as a reaction catalyst, and 6 at 60 ° C. React for a long time, the residual isocyanate group is 0.3% or less At the time point, the reaction was terminated, and urethane (meth) acrylate compound (X-4) (weight average molecular weight (Mw) 1,900, viscosity 2,200 mPa · s / 60 ° C., ethylenically unsaturated group content 3.9 mmol / G).

<Comparative Example 1: Urethane (meth) acrylate-based compound (X'-1)>
In a flask equipped with a thermometer, a stirrer, and a water-cooled condenser, 534.4 g (0.89 mol) of an isocyanurate compound (isocyanate group content 21.1%) of hexamethylene diisocyanate, 2-hydroxypropyl acrylate 465. 6 g (3.58 mol) was charged, 0.5 g of hydroquinone methyl ether as a polymerization inhibitor and 0.1 g of dibutyltin dilaurate as a reaction catalyst were allowed to react at 60 ° C. for 6 hours, and the residual isocyanate group was 0.3% or less. The reaction was terminated at that time, and the urethane (meth) acrylate compound (X′-1) (weight average molecular weight (Mw) 2,000, viscosity 3,500 mPa · s / 60 ° C., ethylenically unsaturated group content 3.58 mmol / g) was obtained.

<Comparative Example 2: Urethane (meth) acrylate compound (X'-2)>
In a flask equipped with a thermometer, a stirrer, and a water-cooled condenser, 680.4 g (1.38 mol) of allophanate-modified diisocyanate (isocyanate group content 17.0%, allophanate group content 1) and 2-hydroxyethyl acrylate 319 .6 g (2.75 moles), 0.1 g of dibutylhydroxytoluene as a polymerization inhibitor and 0.05 g of dibutyltin dilaurate as a reaction catalyst were allowed to react at 60 ° C. for 4 hours. Then, the reaction was terminated, and urethane acrylate oligomer (X′-2) (weight average molecular weight (Mw) 1,200, viscosity 360 mPa · s / 60 ° C., ethylenically unsaturated group content 2.75 mmol / g) was obtained.

In 100 parts of the urethane (meth) acrylate compound obtained in the above examples and comparative examples, a photopolymerization initiator (B): 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd., “Irgacure 184”) 4 parts are blended and coated on a black acrylic base material (manufactured by Nippon Test Panel Co., Ltd., 2x70x150 mm) with an applicator so that the cured coating has a thickness of 40 μm, using a high pressure mercury lamp 80 W / cm, 1 lamp UV irradiation (integrated irradiation amount 1000 mJ / cm ² ) was performed twice at a conveyor speed of 3.5 m / min from a height of 18 cm to obtain a cured coating film.
The following evaluation was performed about the obtained cured coating film. The evaluation results are shown in Table 1.

<Restorability>
Using the above-mentioned cured coating film, using a brass brush, scratching the coating film 5 times with a load of 500 g, leaving it in a dryer at 40 ° C., and measuring the time when the scratch could not be visually confirmed. .
(Evaluation criteria)
○: The wound recovers in less than 1 hour. Δ: The wound recovers in 1 hour or more and less than 12 hours. X: The wound has not been recovered after 12 hours.

<Surface tack>
The surface of the cured coating film was touched with a finger and the tackiness was evaluated.
(Evaluation criteria)
○… There is almost no tack on the surface of the cured coating film. △… The tackiness on the surface of the cured coating film is small.

<Hardness>
About the cured coating film, pencil hardness was measured according to JISK5600-5-4.
(Evaluation criteria)
○ Pencil hardness is 9H ~ H
Δ: Pencil hardness is F to HB
X: Pencil hardness B-6B

  From the said evaluation result, the cured coating film of Examples 1-4 obtained using the urethane (meth) acrylate type compound which uses the polyvalent isocyanate type compound containing two or more allophanate groups is a restoring property and surface hardness. It can be seen that it is excellent in balance.

  On the other hand, the cured coating film of Comparative Example 1 obtained by using a polyvalent isocyanate compound and a urethane (meth) acrylate compound not containing an allophanate group is excellent in hardness but has a rigid isocyanurate structure. Since the flexibility becomes insufficient, it can be seen that the resilience is inferior.

  Moreover, since the cured coating film of Comparative Example 2 obtained using a urethane (meth) acrylate compound using a polyvalent isocyanate compound containing only one allophanate group is difficult to obtain a three-dimensional structure, it has a restorability. It can be seen that the surface hardness is inferior.

  Since the urethane (meth) acrylate compound of the present invention can form a cured coating film having excellent resilience and hardness against scratches when cured, it can form a highly practical cured coating film, paint, It is particularly useful as an ink, a coating agent, particularly as a coating agent for the outermost surface.

Claims (10)

  A urethane (meth) acrylate compound characterized by using a polyvalent isocyanate compound (a1) containing two or more allophanate groups.   The urethane (meth) acrylate system according to claim 1, wherein the urethane (meth) acrylate system is obtained by reacting a polyvalent isocyanate compound (a1) containing two or more allophanate groups and a hydroxyl group-containing (meth) acrylate compound (a2). Compound.   2. The polyisocyanate compound (a1) containing two or more allophanate groups, a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3) are reacted. Urethane (meth) acrylate compounds.   The polyvalent isocyanate compound (a1) containing two or more allophanate groups contains two or more allophanate groups obtained by reacting the polyvalent isocyanate compound (a1-1) and the hydroxyl group-containing compound (a1-2). The urethane (meth) acrylate compound according to claim 1, which is a polyvalent isocyanate compound.   The urethane (meth) acrylate compound according to any one of claims 1 to 4, wherein the polyvalent isocyanate compound (a1) containing two or more allophanate groups is a compound containing four or more isocyanate groups. .   The urethane (meth) acrylate compound according to claim 4 or 5, wherein the hydroxyl group-containing compound (a1-2) is a diol.   The urethane (meth) acrylate compound according to any one of claims 1 to 6, wherein the urethane (meth) acrylate compound has an ethylenically unsaturated group content of 0.01 to 10 mmol / g.   The urethane (meth) acrylate compound according to any one of claims 1 to 7, wherein the urethane (meth) acrylate compound has a weight average molecular weight of 800 to 800,000.   An active energy ray-curable resin composition comprising the urethane (meth) acrylate compound according to claim 1.   A coating agent comprising the active energy ray-curable resin composition according to claim 9.