JP6112012B2 - Aqueous polyurethane resin dispersion and use thereof - Google Patents

Description

  The present invention relates to an aqueous urethane resin dispersion curable with active energy rays such as ultraviolet rays and the use thereof.

  Polycarbonate polyol is a useful compound that can be used as a raw material for polyurethane resins, and can react with isocyanate compounds to produce polyurethane resins used in rigid foams, flexible foams, paints, adhesives, synthetic leather, ink binders, and the like. . A coating film obtained by applying an aqueous polyurethane resin dispersion using polycarbonate polyol as a raw material is known to have excellent light resistance, weather resistance, heat resistance, hydrolysis resistance, and oil resistance (Patent Documents). 1).

  Among them, a coating film obtained by applying an aqueous urethane resin dispersion using an aliphatic polycarbonate polyol is known to be used as an undercoat agent because of improved adhesion to a substrate and blocking resistance. (See Patent Document 2). However, when only the aliphatic polycarbonate polyol is used as a raw material, the hardness of the coating film obtained from the aqueous polyurethane resin dispersion and the adhesion to the base material are, for example, automobile interior materials, mobile phone cases, and home appliances. There has been a problem that it is not sufficient in the field of paints and coating agents for synthetic resin moldings such as casings, personal computer casings, decorative films, optical films, flooring materials such as flooring.

  In order to improve the hardness and durability of the coating film, an aqueous polyurethane resin dispersion using a polycarbonate polyol having an alicyclic structure has also been proposed (see Patent Documents 3, 4 and 5). However, when a polycarbonate polyol having an alicyclic structure is used, there is a problem that the dispersibility of the polyurethane resin in an aqueous medium is deteriorated, and the handleability and stability of the aqueous polyurethane resin dispersion are inferior. In addition, for example, with respect to Patent Document 3, regarding the aqueous polyurethane resin dispersion, the influence on adhesiveness has not been clarified, and the dispersibility in an aqueous medium has not been satisfactory. .

  Regarding the coating film hardness, in the case of a hard coat application, the coating film generally requires a pencil hardness of 2H or more. Therefore, the use of urethane (meth) acrylate has been studied for the purpose of increasing the coating film hardness. For example, an aqueous radiation-curable composition containing a (meth) acrylated polyurethane prepolymer and an ethylenically unsaturated compound ( Patent Document 6), and an aqueous irradiation curable composition (see Patent Document 7) containing a high molecular weight ethylenically unsaturated polyurethane and a low molecular weight ethylenically unsaturated polyurethane have been proposed.

JP-A-10-120757 JP 2005-281544 A JP-A-6-248046 International Publication No. 2009/145242 International Publication No. 2009/004951 Special table 2009-533504 gazette International Publication No. 2009/147092

However, the composition specifically disclosed in Patent Document 6 uses a bifunctional (meth) acrylate having a secondary hydroxyl group in the production of a (meth) acrylated polyurethane prepolymer, or has a hydroxyl value of 80 mgKOH / g. Less than DPHA is used in small amounts. Therefore, it was necessary to lengthen the reaction time under heating during the production of the prepolymer, and it was found that the problem of yellowing occurs even when using a non-yellowing type isocyanate having no aromatic ring. Moreover, in order to shorten the reaction time, if a large amount of DPHA having a hydroxyl value of less than 80 mgKOH / g is used, or if a bifunctional (meth) acrylate having a secondary hydroxyl group is not used, the storage stability of the aqueous radioactive composition is increased. It has been found that there is a problem that the adhesiveness is insufficient when the coating film of the composition is formed on a polymethyl methacrylate resin (PMMA resin).
In addition, the composition specifically disclosed in Patent Document 7 has a problem that it does not adhere to the (meth) acrylic resin used for various uses as a transparent material and the pencil hardness is too low. I understood it.

  An object of the present invention is to provide an aqueous polyurethane resin dispersion having a short production time, excellent storage stability, and a coating film after curing by irradiation with active energy rays (for example, ultraviolet rays) having high hardness. In the present invention, the coating film after curing by irradiation with active energy rays (for example, ultraviolet rays) is used as a base material, particularly (meth) acrylic resin (for example, polymethyl methacrylate resin (PMMA resin)) and acrylonitrile-butylene- It is an object to provide an aqueous polyurethane resin dispersion having high adhesion to a styrene resin (ABS resin).

  As a result of various investigations to overcome the problems of the prior art, the present inventors have found that a polyurethane resin (A) having a polymerizable unsaturated bond has a polyol (a), an acidic group-containing polyol ( b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d), which are obtained by reacting at least, and this polyurethane resin (A) has a polymerizable unsaturated bond. The problem is solved by the aqueous polyurethane resin dispersion obtained by combining the compound (B) having a primary hydroxyl group-containing (meth) acrylate (d) with a total amount of 60 to 80% by weight of the total resin solid content. The knowledge that it can be obtained was obtained, and the present invention was achieved. Here, resin solid content means the sum total of a polyurethane resin (A) and the compound (B) which has a polymerizable unsaturated bond. However, the resin solid content does not include a neutralizing agent such as a base or an alkali used for neutralizing the acidic group of the acidic group-containing polyol (b).

The present invention (1) is an aqueous polyurethane resin dispersion composition in which at least a polyurethane resin (A) having a polymerizable unsaturated bond and a compound (B) having a polymerizable unsaturated bond are dispersed in an aqueous medium. A thing,
The polyurethane resin (A) having a polymerizable unsaturated bond comprises at least a polyol (a), an acidic group-containing polyol (b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d). It is obtained by reacting,
An aqueous polyurethane resin characterized in that the total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 60 to 80% by weight of the entire resin solid content. Concerning the dispersion.
The present invention (2) relates to the aqueous polyurethane resin dispersion of the present invention (1), wherein the polyol (a) is a polycarbonate diol.
In the present invention (3), the total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 65 to 75% by weight based on the entire resin solid content. The invention relates to the aqueous polyurethane resin dispersion of the invention (1) or (2).
The invention (4) is any one of the inventions (1) to (3), wherein the compound (B) having a polymerizable unsaturated bond is a compound having 3 or more (meth) acryloyl groups in one molecule. To an aqueous polyurethane resin dispersion.
In the present invention (5), the compound (B) having a polymerizable unsaturated bond is produced by converting alkylene oxide-modified pentaerythritol tetra (meth) acrylate, alkylene oxide-modified trimethylolpropane tri (meth) acrylate, alkylene oxide-modified ethylene glycol di ( The aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (3), which is at least one selected from the group consisting of (meth) acrylates.
The invention (6) is an aqueous polyurethane resin dispersion according to any one of the inventions (1) to (5), wherein the compound (B) having a polymerizable unsaturated bond is an alkylene oxide-modified pentaerythritol tetra (meth) acrylate. About the body.
In the present invention (7), the primary hydroxyl group-containing (meth) acrylate (d) is subjected to a reaction for obtaining a polyurethane resin (A) as a mixture with (meth) acrylate that is inert to the isocyanato group. The aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (6).
The present invention (8) includes dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate having a primary hydroxyl group-containing (meth) acrylate (d) having a hydroxyl value of 80 mgKOH / g or more and 120 mgKOH / g or less. This invention relates to the aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (7), which is subjected to a reaction for obtaining the polyurethane resin (A).
In the present invention (9), the primary hydroxyl group-containing (meth) acrylate (d) is a mixture of pentaerythritol tetra (meth) acrylate and pentaerythritol tri (meth) acrylate having a hydroxyl value of 100 mgKOH / g or more and 280 mgKOH / g or less. The present invention relates to the aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (7), which is subjected to a reaction for obtaining the polyurethane resin (A).
The present invention (10) includes a photopolymerization initiator, an optical curable composition comprising any of the aqueous polyurethane resin dispersion of the present invention (1) to (9).
The present invention (11) relates to a coating composition containing the aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (9).
This invention (12) is related with the coating composition of this invention (11) for (meth) acrylic resins or acrylonitrile-butylene-styrene resins.
The present invention (13) relates to a coating agent composition containing the aqueous polyurethane resin dispersion according to any one of the present inventions (1) to (9).
This invention (14) relates to the coating agent composition of this invention (13) for (meth) acrylic resin or acrylonitrile-butylene-styrene resin.

  According to the present invention, there is provided an aqueous polyurethane resin dispersion having a short manufacturing time, excellent storage stability, and a coating film after curing by irradiation with active energy rays (for example, ultraviolet rays) having high hardness. In addition, according to the present invention, the coating film after being cured by irradiation with active energy rays (for example, ultraviolet rays) has high adhesion to substrates, particularly (meth) acrylic resins and acrylonitrile-butylene-styrene resins (ABS resins). An aqueous polyurethane resin dispersion having properties is provided.

The present invention is an aqueous polyurethane resin dispersion obtained by dispersing at least a polyurethane resin (A) having a polymerizable unsaturated bond and a compound (B) having a polymerizable unsaturated bond in an aqueous medium,
The polyurethane resin (A) having a polymerizable unsaturated bond comprises a polyol (a), an acidic group-containing polyol (b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d). The present invention relates to an aqueous polyurethane resin dispersion obtained by reacting at least.

<Polyurethane resin (A) having a polymerizable unsaturated bond>
<< Polyol (a) >>
As the polyol (a), for example, a high molecular weight polyol or a low molecular weight polyol can be used. It is preferable to use a high molecular weight diol or a low molecular weight diol because of the ease of producing the aqueous polyurethane resin dispersion.

  The high molecular weight diol is not particularly limited, but the number average molecular weight is preferably 400 to 8000. If the number average molecular weight is in this range, an appropriate viscosity and good handleability can be easily obtained. It is easy to ensure the performance as a soft segment, and when a coating film is formed using the aqueous polyurethane resin dispersion containing the obtained polyurethane resin, it is easy to suppress the occurrence of cracks, and further, polyisocyanate (c) and The polyurethane resin (A) can also be produced efficiently. The polyol (a) preferably has a number average molecular weight of 400 to 4000.

  In the present specification, the number average molecular weight is a number average molecular weight calculated based on a hydroxyl value measured in accordance with JIS K 1577. Specifically, the hydroxyl value is measured, and is calculated as (56.1 × 1000 × valence) / hydroxyl value [mgKOH / g] by a terminal group quantification method. In the above formula, the valence is the number of hydroxyl groups in one molecule.

  Examples of the high molecular weight diol include polycarbonate diol, polyester diol, and polyether diol. Polycarbonate diol is preferred from the viewpoint of light resistance, weather resistance, heat resistance, hydrolysis resistance, and oil resistance of the aqueous polyurethane resin dispersion containing the obtained polyurethane resin and the coating film obtained therefrom.

  Among polycarbonate diols, the diol component is preferably an aliphatic diol and / or an alicyclic diol, and the resulting polyurethane resin has a low viscosity, is easy to handle, and has good dispersibility in an aqueous medium. From the viewpoint, the diol component is more preferably an aliphatic diol having no alicyclic structure.

  The polycarbonate polyol is obtained by reacting one or more polyol monomers with a carbonate ester or phosgene. A polycarbonate polyol obtained by reacting one or more polyol monomers with a carbonate ester is preferred because it is easy to produce and has no by-product formation of terminal chlorinated products.

  The polyol monomer is not particularly limited, and examples thereof include an aliphatic polyol monomer, a polyol monomer having an alicyclic structure, an aromatic polyol monomer, a polyester polyol monomer, and a polyether polyol monomer.

  The aliphatic polyol monomer is not particularly limited, and examples thereof include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 Linear aliphatic diols such as 1,8-octanediol and 1,9-nonanediol; 2-methyl-1,3-propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5 -Branched aliphatic diols such as pentanediol and 2-methyl-1,9-nonanediol; and trifunctional or higher functional polyhydric alcohols such as trimethylolpropane and pentaerythritol.

  The polyol monomer having an alicyclic structure is not particularly limited, and examples thereof include 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1, Alicyclic ring in the main chain such as 4-cycloheptanediol, 2,5-bis (hydroxymethyl) -1,4-dioxane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 1,4-bis (hydroxyethoxy) cyclohexane Examples thereof include diols having a formula structure.

  The aromatic polyol monomer is not particularly limited. For example, 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4′-naphthalenediethanol, 3,4 '-Naphthalene diethanol and the like.

  Although it does not restrict | limit especially as a polyester polyol monomer, For example, dicarboxylic acid, such as polyester polyol of hydroxycarboxylic acid and diol, such as polyester polyol of 6-hydroxycaproic acid and hexanediol, polyester polyol of adipic acid and hexanediol And polyester polyol of diol.

  The polyether polyol monomer is not particularly limited, and examples thereof include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

  The carbonate is not particularly limited, and examples thereof include aliphatic carbonates such as dimethyl carbonate and diethyl carbonate, aromatic carbonates such as diphenyl carbonate, and cyclic carbonates such as ethylene carbonate. In addition, phosgene or the like capable of producing a polycarbonate polyol can be used. Among these, aliphatic carbonates are preferable and dimethyl carbonate is particularly preferable because of easy manufacture of polycarbonate polyols.

  As a method for producing a polycarbonate polyol from a polyol monomer and a carbonate ester, for example, a carbonate ester and a polyol having an excess number of moles relative to the number of moles of the carbonate ester are added to a reactor, and the temperature is 160 to 200 ° C. Examples include a method of reacting at a pressure of about 50 mmHg for 5 to 6 hours and further reacting at 200 to 220 ° C. for several hours at a pressure of several mmHg or less. In the above reaction, it is preferable to carry out the reaction while extracting by-produced alcohol out of the system. At that time, if the carbonate ester escapes from the system by azeotroping with the by-produced alcohol, an excessive amount of carbonate ester may be added. In the above reaction, a catalyst such as titanium tetrabutoxide may be used.

  Polyester diol is not particularly limited, but for example, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene sebacate diol , Polybutylene sebacate diol, poly-ε-caprolactone diol, poly (3-methyl-1,5-pentylene adipate) diol, polycondensate of 1,6-hexanediol and dimer acid, and the like.

  The polyether diol is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide, and a random copolymer or block copolymer of ethylene oxide and butylene oxide. Further, a polyether polyester polyol having an ether bond and an ester bond may be used.

  Although it does not restrict | limit especially as low molecular weight diol, For example, a number average molecular weight is 60 or more and less than 400 thing is mentioned. For example, ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol Aliphatic diol having 2 to 9 carbon atoms such as diethylene glycol, triethylene glycol and tetraethylene glycol; 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-bis (Hydroxyethyl) cyclohexane, 2,7-norbornanediol, tetrahydrofuran Examples thereof include diols having an alicyclic structure having 6 to 12 carbon atoms such as methanol and 2,5-bis (hydroxymethyl) -1,4-dioxane. Furthermore, low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol, and sorbitol may be used as the low molecular weight polyol.

  A polyol (a) may be used independently and may use multiple types together.

<< Acid group-containing polyol (b) >>
The acidic group-containing polyol (b) contains two or more hydroxyl groups and one or more acidic groups in one molecule. Examples of the acidic group include a carboxy group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group. The acidic group-containing polyol (b) preferably contains a compound having two hydroxyl groups and one carboxy group in one molecule. An acidic group containing polyol (b) may be used independently and may use multiple types together.

  Specific examples of the acidic group-containing polyol (b) include dimethylol alkanoic acids such as 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid, N, N-bishydroxyethylglycine, N, N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid and the like can be mentioned. Among them, from the viewpoint of easy availability, dimethylol alkanoic acid having 4 to 12 carbon atoms containing two methylol groups is preferable, and 2,2-dimethylolpropionic acid is more preferable among dimethylolalkanoic acids.

  In the present invention, the total number of hydroxyl equivalents of the polyol (a) and the acidic group-containing polyol (b) is preferably 120 to 600. If the number of hydroxyl equivalents is within this range, it is easy to produce an aqueous polyurethane resin dispersion containing the obtained polyurethane resin, and it is easy to obtain a coating film excellent in hardness. From the viewpoint of the storage stability of the resulting aqueous polyurethane resin dispersion and the hardness of the coating film obtained by coating, the hydroxyl equivalent number is preferably 130 to 600, more preferably 150 to 500, and particularly preferably 170 to 400. is there.

The number of hydroxyl equivalents can be calculated by the following formulas (1) and (2).
Number of hydroxyl equivalents of each polyol = molecular weight of each polyol / number of hydroxyl groups of each polyol (1)
Total number of hydroxyl equivalents of polyol = M / total number of moles of polyol (2)
In the case of the polyurethane resin (A), in the formula (2), M is [[number of hydroxyl equivalents of polyol (a) × number of moles of polyol (a)] + [number of hydroxyl equivalents of acidic group-containing polyol (b) × The number of moles of the acidic group-containing polyol (b)]].

<< Polyisocyanate (c) >>
Although it does not restrict | limit especially as polyisocyanate (c), For example, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate etc. are mentioned.

  Specific examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4′-. Diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4 Examples include '-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4', 4 ''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate, and the like.

  Specific examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate. Lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexano Eate.

  Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2 -Isocyanatoethyl) -4-dichlorohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

  The number of isocyanato groups per molecule of the polyisocyanate is usually two, but a polyisocyanate having three or more isocyanato groups such as triphenylmethane triisocyanate is also used as long as the polyurethane resin in the present invention does not gel. be able to.

  Among the polyisocyanates, alicyclic polyisocyanates having an alicyclic structure are preferable from the viewpoint of increasing the hardness after curing with active energy rays (for example, ultraviolet rays), and isophorone diisocyanate is preferable because the reaction can be easily controlled. (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI) is particularly preferred.

  Polyisocyanate may be used independently and may use multiple types together.

<< Primary hydroxyl group-containing (meth) acrylate (d) >>
The primary hydroxyl group-containing (meth) acrylate is not particularly limited as long as it is a meta (acrylate) compound having a primary hydroxyl group. The “primary hydroxyl group” in the present specification means a hydroxyl group in which an oxygen atom of the hydroxyl group is bonded to a methylene group. In addition, “(meth) acryloyl compound”, “(meth) acrylate compound”, and “(meth) acrylate” in the present specification are all concepts including a compound having an acryloyl group and a compound having a methacryloyl group. Yes, it may have both an acryloyl group and a methacryloyl group.

  As primary hydroxyl group-containing (meth) acrylate (d), 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerin di (meth) acrylate, diglycerin Tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, sorbitol penta (meth) acrylate, glycerol mono (meth) acrylate, diglycerol mono (meth) acrylate, pentaerythritol mono (meta) ) Acrylate, sorbitol mono (meth) acrylate diglycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol di (meth) acrylate, di Pentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, sorbitol di (meth) acrylate, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate.

  Among them, those having 3 or more (meth) acryloyl groups in one molecule are preferable from the viewpoint of increasing the hardness after curing with active energy rays (for example, ultraviolet rays). As such (meth) acrylate, diglycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, sorbitol penta (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, Examples include dipentaerythritol penta (meth) acrylate, sorbitol tri (meth) acrylate, and sorbitol tetra (meth) acrylate.

  Among primary hydroxyl group-containing (meth) acrylates in which the number of (meth) acryloyl groups in one molecule is 3 or more, only primary hydroxyl groups are used in that the production time of the polyurethane resin (A) can be shortened. The (meth) acrylate compound possessed is more preferred. Examples of such (meth) acrylates include pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and dipentaerythritol penta (meth) acrylate. From the viewpoint of the hardness of the coating film and the production time, dipentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate are particularly preferable.

  The primary hydroxyl group-containing (meth) acrylate (d) may be used alone or in combination.

  A commercially available product may be used as it is as the primary hydroxyl group-containing (meth) acrylate.

  The primary hydroxyl group-containing (meth) acrylate can be subjected to a reaction for obtaining the polyurethane resin (A) as a mixture with (meth) acrylate inert to the isocyanato group. The (meth) acrylate inert to the unreacted isocyanato group can constitute the compound (B) having a polymerizable unsaturated bond.

  As the mixture, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, commercially available dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) Examples thereof include a mixture of acrylates and a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. Dipentaerythritol hexa (meth) acrylate corresponds to (meth) acrylate that is inert to the isocyanato group.

  A mixture of dipentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, or a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate The hydroxyl value is preferably 80 mgKOH / g or more. If the hydroxyl value is within this range, it is possible to easily avoid the problem that the production of the polyurethane resin (A) takes time and the resin is colored. The hydroxyl value is preferably 80 to 130 mgKOH / g from the viewpoint of suppressing an increase in viscosity during production of the polyurethane resin (A) and avoiding gelation. The hydroxyl value is 85 to 120 mg KOH / g. Examples of the mixture of dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate having a hydroxyl value of 80 mgKOH / g or more include Aronix M403 manufactured by Toagosei Co., Ltd.

  Moreover, the mixture of a pentaerythritol triacrylate and a pentaerythritol tetraacrylate can also be used as a mixture. Pentaerythritol tetraacrylate corresponds to (meth) acrylate containing no primary hydroxyl group. In this case, the hydroxyl value is preferably 100 to 280 mgKOH / g. If the hydroxyl value is within this range, it is possible to easily avoid the problem that the production of the polyurethane resin (A) takes time and the resin is colored. The hydroxyl value is preferably 120 to 250 mgKOH / g from the viewpoint of suppressing an increase in viscosity during production of the polyurethane resin (A) and avoiding gelation. A more preferred hydroxyl value is 140 to 220 mgKOH / g. Examples of the mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate having a hydroxyl value of 100 to 280 mgKOH / g include Aronix M305 and M306 manufactured by Toagosei Co., Ltd.

  The hydroxyl value of the above mixture is measured by the method described in JIS K0070.

  The amount of the primary hydroxyl group-containing (meth) acrylate (d) is preferably 25 to 70% by weight in the weight of the polyurethane resin (A) having a polymerizable unsaturated bond. Within this range, the reaction time of the primary hydroxyl group-containing (meth) acrylate (d) and the isocyanate group is within an appropriate time, and the hardness of the coating film after curing with active energy rays (for example, ultraviolet rays) is within an appropriate range. And the storage stability of the aqueous polyurethane resin dispersion containing the obtained polyurethane resin can be kept good. The primary hydroxyl group-containing (meth) acrylate (d) is more preferably 30 to 70% by weight.

  A primary hydroxyl group-containing (meth) acrylate (d) is mixed with a (meth) acrylate inert to an isocyanato group (specifically, dipentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate) As a mixture of dipentaerythritol hexa (meth) acrylate, a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, etc. The amount of the mixture is preferably 50 to 80% by weight, more preferably 60 to 80% by weight, based on the weight of the polyurethane resin (A) having a polymerizable unsaturated bond.

<Polyurethane resin (A) having a polymerizable unsaturated bond>
The polyurethane resin (A) having a polymerizable unsaturated bond (hereinafter also referred to as “polyurethane resin (A)”) includes at least a polyol (a), an acidic group-containing polyol (b), and a polyisocyanate (c). It is a polyurethane resin obtained by reacting a primary hydroxyl group-containing (meth) acrylate (d). The polymerizable unsaturated bond can be derived from the (meth) acryloyl group of the primary hydroxyl group-containing (meth) acrylate (d).

  The ratio of the number of moles of isocyanate groups of the polyisocyanate (c) to the number of moles of all hydroxyl groups in the polyol (a), the acidic group-containing polyol (b), and the primary hydroxyl group-containing (meth) acrylate (d) is 0. .1 to 0.9 is preferable.

  If it is this range, while it is easy to avoid the problem that reaction time becomes long when there are too few moles of a hydroxyl group, an unreacted polyol (a) and acidic group containing by too many moles of a hydroxyl group The problem that the polyol (b) and the primary hydroxyl group-containing (meth) acrylate (d) remain in a large amount and the storage stability is lowered can be easily avoided. The ratio of the number of moles of isocyanato groups of the polyisocyanate (c) to the number of moles of all hydroxyl groups is preferably 0.15 to 0.8, particularly preferably 0.2 to 0.7.

  In the reaction of the polyol (a), the acidic group-containing polyol (b), the polyisocyanate (c), and the primary hydroxyl group-containing (meth) acrylate (d), (a), (b), (d) are in any order, ( You may make it react with c), and may mix multiple types and make it react with (c). The primary hydroxyl group-containing (meth) acrylate (d) may be subjected to the reaction as a mixture with (meth) acrylate that is inert to the isocyanato group.

  When reacting the polyol (a), the acidic group-containing polyol (b), the primary hydroxyl group-containing (meth) acrylate (d) and the polyisocyanate (c), a catalyst may be used.

  The catalyst is not particularly limited, and examples thereof include salts of metals such as tin (tin) catalysts (trimethyltin laurate, dibutyltin dilaurate, etc.) and lead catalysts (lead octylate, etc.), organic and inorganic acids, and organic metals. Derivatives, amine catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.), diazabicycloundecene catalysts, and the like can be given. Of these, dibutyltin dilaurate and dioctyltin dilaurate are preferable from the viewpoint of reactivity.

  Although the reaction temperature at the time of making it react is not restrict | limited in particular, 40-120 degreeC is preferable. If it is this range, the solubility of the raw material is good, the viscosity of the obtained urethane resin (A) is appropriate and can be sufficiently stirred, the (meth) acryloyl group causes a polymerization reaction, gelled, Problems such as the isocyanato group causing side reactions are less likely to occur. The reaction temperature is more preferably 60 to 100 ° C.

  When the primary hydroxyl group-containing (meth) acrylate (d) is reacted with the polyisocyanate (c), unnecessary consumption of the (meth) acryloyl group of the primary hydroxyl group-containing (meth) acrylate (d) is avoided. Therefore, it is preferable to carry out in the presence of oxygen.

  In order to avoid unnecessary consumption of the (meth) acryloyl group of the primary hydroxyl group-containing (meth) acrylate (d), a polymerization inhibitor may be added to the reaction system.

As polymerization inhibitors, hydroquinone, hydroquinone monomethyl ether, benzoquinone, 2-tert-butylhydroquinone, p-tert-butylcatechol, 2,5-bis (1,1,3,3-tetramethylbutyl) hydroquinone, 2, Quinone polymerization inhibitors such as 5-bis (1,1-dimethylbutyl) hydroquinone; 2,6-bis (1,1-dimethylethyl) -4-methylphenol, 2,6-di-tert-butylphenol, 2 , 4-di-tert-butylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, etc. Alkylphenol polymerization inhibitors; aromatic amine polymerization inhibitors such as phenothiazine; alkylated diphenylamine, N, N′-diphenyl-p Phenylenediamine, phenothiazine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy-2,2,6 6-tetramethylpiperidine, 1-hydroxy-4-benzoyl oxy-2,2,6,6-tetramethylpiperidine, di -p- fluorophenyl amine, 2,2,6,6-tetramethylpiperidine-1- Amine polymerization inhibitors such as oxyl (TEMPO); 2,2-diphenylpicrylhydrazyl (DPPH), tri-p-nitrophenylmethyl, N- (3N-oxyanilino-1,3-dimethylbutylidene) -aniline Quaternary ammonium chlorides such as oxide and benzyltrimethylammonium chloride; Min, cyclic amides, nitrile compounds, substituted ureas, benzothiazole, bis - (1,2,2,6,6-pentamethyl-4-piperazinyl Li Jiniru) Sepaketo, lactic acid, oxalic acid, citric acid, tartaric acid, such as benzoic acid Organic acids; organic phosphines, phosphites and the like. These may be single and may use multiple types together. In particular, by using a quinone polymerization inhibitor and an alkylphenol polymerization inhibitor in combination, the consumption due to polymerization of the (meth) acryloyl group can be further reduced.

  The amount of the polymerization inhibitor is 0.001 to 1 with respect to a total of 100 parts by weight of the polyol (a), the acidic group-containing polyol (b), the primary hydroxyl group-containing (meth) acrylate (d) and the polyisocyanate (c). It can be made into a weight part, Preferably it is 0.01-0.5 weight part.

  The reaction with the polyol (a), the acidic group-containing polyol (b), the primary hydroxyl group-containing (meth) acrylate (d) and the polyisocyanate (c) may be carried out without a solvent or in the presence of an organic solvent. You may do it. Examples of the organic solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone, and ethyl acetate. Among these, acetone, methyl ethyl ketone, and ethyl acetate are preferable because the polyurethane resin (A) can be removed by heating under reduced pressure after being dispersed in water. Further, N-methylpyrrolidone and N-ethylpyrrolidone are preferable because they function as a film-forming aid when a coating film is produced using the obtained aqueous polyurethane resin dispersion containing a polyurethane resin.

  The amount of the organic solvent is preferably 0 to 2 on a weight basis with respect to the total amount of polyol (a), acidic group-containing polyol (b), primary hydroxyl group-containing (meth) acrylate (d) and polyisocyanate (c). 0.0 times, more preferably 0.05 to 0.7 times. If it is this range, the process which removes an organic solvent will take time, the dispersibility to the water of the obtained polyurethane resin will also be favorable, and organic in the coating film produced using the aqueous polyurethane resin dispersion. The problem that the solvent remains and the physical properties of the coating film deteriorate can be avoided.

<Compound (B) having polymerizable unsaturated bond>
The aqueous polyurethane resin dispersion of the present invention contains a compound (B) having a polymerizable unsaturated bond. The compound (B) having a polymerizable unsaturated bond is preferably a radical polymerizable compound. The radical polymerizable compound is not particularly limited as long as it is polymerized in the presence of a photo radical generator or in the presence of a thermal radical generator, but a (meth) acrylate compound is preferable.

  Examples of the radical polymerizable compound include monomers (meth) acrylate compounds, polyurethane (meth) acrylate compounds, polyester (meth) acrylate compounds, polyalkylene (meth) acrylate compounds, and the like.

  Monomer (meth) acrylate compounds include mono (meth) acrylate, di (meth) acrylate, tri (meth) acrylate, tetra (meth) acrylate, penta (meth) acrylate, hexa (meth) acrylate and the like ( And (meth) acrylate.

  Examples of the mono (meth) acrylate include acryloylmorpholine, 2-ethylhexyl (meth) acrylate, styrene, methyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, N-vinyl-2-pyrrolidone, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono ( (Meth) acrylate, polyethylene glycol-polypropylene glycol mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) ) Mono (meth) acrylate, poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate, methoxypolyethyleneglycol mono (meth) acrylate, octoxypolyethyleneglycol-polypropyleneglycolmono (meth) acrylate, lauroxypolyethyleneglycolmono ( And (meth) acrylate, stearoxy polyethylene glycol mono (meth) acrylate, nonylphenoxy polyethylene glycol mono (meth) acrylate, nonylphenoxy polypropylene glycol polyethylene glycol mono (meth) acrylate, and the like.

  Examples of the di (meth) acrylate include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polypropylene glycol di (meth) acrylate. 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) Acrylate, polyethylene glycol-polypropylene glycol di (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) di (meth) acrylate, poly (propylene Glycol-tetramethylene glycol) di (meth) acrylate, methoxypolyethyleneglycol di (meth) acrylate, octoxypolyethyleneglycol-polypropyleneglycol di (meth) acrylate, lauroxypolyethyleneglycol di (meth) acrylate, stearoxypolyethyleneglycoldi Reaction of (meth) acrylate, nonylphenoxypolyethylene glycol di (meth) acrylate, nonylphenoxypolypropylene glycol polyethylene glycol di (meth) acrylate, 2 molecules of (meth) acrylic acid and 1 molecule of 1,6-hexanediol diglycidyl Product (for example, “DA-212” manufactured by Nagase ChemteX Corporation), 2 molecules of epoxy (meth) acrylic acid and 1 molecule of neopentyl glycol di Reaction product with ricidyl, reaction product of 2 molecules of (meth) acrylic acid and 1 molecule of bisphenol A diglycidyl (eg “DA-250” manufactured by Nagase Chemtech), 2 molecules of (meth) acrylic acid and A reaction product of a propylene oxide adduct of bisphenol A with a diglycidyl compound, a reaction product of two molecules of (meth) acrylic acid and one molecule of diglycidyl phthalate (for example, “DA-721” manufactured by Nagase Chemtech) Reaction product of two molecules of (meth) acrylic acid and one molecule of polyethylene glycol diglycidyl (for example, “DM-811”, “DM-832”, “DM-851” manufactured by Nagase Chemtech) (Meth) acrylic acid and polyol diglycy such as reaction product of (meth) acrylic acid and 1 molecule of polypropylene glycol diglycidyl Reaction products with jill, adducts of glycidyl (meth) acrylate and (meth) acrylic acid, and the like.

  Examples of the tri (meth) acrylate include trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Alkylene oxide-modified trimethylolpropane tri (meth) acrylate (BASF's Laromer (registered trademark) PO33F) such as ethylene oxide (6 mol) modified trimethylolpropane tri (meth) acrylate (BASF's Laromer (registered trademark) LR8863) Is mentioned.

  Examples of the tetra (meth) acrylate include pentaerythritol tetra (meth) acrylate and ethylene oxide (4 mol) modified pentaerythritol tetra (meth) acrylate (Daicel Cytec, Ebecryl 40), etc. ) Acrylate and the like.

  Examples of penta (meth) acrylate include dipentaerythritol penta (meth) acrylate.

  Examples of hexa (meth) acrylate include dipentaerythritol hexa (meth) acrylate.

  A well-known thing can be used as a (meth) acrylate compound of polymers. Examples of the (meth) acrylate compounds of the polymers include poly (meth) acrylates such as di (meth) acrylate, tri (meth) acrylate, and tetra (meth) acrylate in addition to mono (meth) acrylate.

  Among these radical polymerizable compounds, poly (meth) acrylates such as tri (meth) acrylate, tetra (meth) acrylate, penta (meth) acrylate, and hexa (meth) acrylate are preferable from the viewpoint of the hardness of the resulting coating film. .

  Among these radical polymerizable compounds, alkylene oxide-modified pentaerythritol tetra (meth) acrylate, alkylene oxide-modified trimethylolpropane tri (meth) acrylate, alkylene oxide-modified ethylene glycol di ( (Meth) acrylate is preferred. From the viewpoint of compatibility between adhesion and hardness, alkylene oxide-modified pentaerythritol tetra (meth) acrylate is more preferable, and ethylene oxide-modified pentaerythritol tetra (meth) acrylate is particularly preferable from the viewpoint of availability.

  In order to obtain the polyurethane resin (A), when subjected to the reaction as a mixture of a primary hydroxyl group-containing (meth) acrylate (d) and an isocyanato group-inactive (meth) acrylate, the isocyanate group contained in the reaction system The inert (meth) acrylate can constitute the compound (B) having a polymerizable unsaturated bond.

  The total amount of the primary hydroxyl group-containing (meth) acrylate (d) of the polyurethane resin (A) having a polymerizable unsaturated bond and the compound (B) having a polymerizable unsaturated bond is 60 to 80 of the entire resin solid content. % By weight. If it is less than 60% by weight, the hardness of the coating film prepared using the aqueous polyurethane resin dispersion may be reduced, and if it is more than 85% by weight, the storage stability of the aqueous polyurethane resin dispersion may be reduced. . The total amount is more preferably 60 to 80% by weight, still more preferably 65 to 75% by weight.

  When the total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 100% by weight, the compound (B) having a polymerizable unsaturated bond is: It is preferably 30 to 50% by weight. If it is this range, the adhesiveness with respect to the PMMA resin of the coating film produced using the aqueous | water-based polyurethane resin dispersion can be easily obtained, and what has high hardness can also be obtained, and also the storage stability of the water-based polyurethane resin dispersion is also obtained. It is good.

  In the aqueous polyurethane resin dispersion of the present invention, the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond are dispersed in an aqueous medium. Examples of the aqueous medium include water and a mixed medium of water and a hydrophilic organic solvent.

  Examples of water include clean water, ion exchange water, distilled water, and ultrapure water. Among them, it is preferable to use ion-exchanged water in consideration of the availability and the fact that the particles become unstable due to the influence of salt.

  Examples of hydrophilic organic solvents include lower monohydric alcohols such as methanol, ethanol and propanol; polyhydric alcohols such as ethylene glycol and glycerin; N-methylmorpholine, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone and the like. Examples include aprotic hydrophilic organic solvents. The amount of the hydrophilic organic solvent in the aqueous medium is preferably 0 to 20% by weight.

In the present invention, the acid value of the aqueous polyurethane resin dispersion is preferably from 10 to 80 mgKOH / g. If it is this range, it will be easy to ensure the dispersibility to an aqueous medium and the water resistance of a coating film. Specifically, the acid value can be derived from the following formula (3).
[Acid Value of Aqueous Polyurethane Resin Composition] = [Mole Number of Acidic Group of Acidic Group-Containing Polyol (b)] × 56.11 / [Polyurethane Resin (A) and Compound (B) Having Polymerizable Unsaturation Total weight] ... (3)
The acid value is more preferably 12 to 70 mgKOH / g, and still more preferably 14 to 60 mgKOH / g.

  In the present invention, when the solid content of the polyurethane resin aqueous dispersion is 100 parts by weight, the proportion of the polyol (a) is 2 to 50 parts by weight, and the proportion of the acidic group-containing polyol (b) is 1 to 15 parts by weight. It is preferable to prepare the polyurethane resin (A) in such an amount.

When the ratio of the polyol (a) is in the above range, the polyurethane resin (A) has good dispersibility in the aqueous medium, and good film-forming properties can be obtained for the aqueous polyurethane resin dispersion. If the ratio of the contained polyol (b) is in the above range, the water resistance of the coating film is good and the dispersibility of the polyurethane resin (A) in the aqueous medium can be good.
The proportion of the polyol (a) is more preferably 3 to 40 parts by weight, particularly preferably 5 to 30 parts by weight, and the proportion of the acidic group-containing polyol (b) is more preferably 2 to 10 parts by weight, particularly preferably. Is 3 to 7 parts by weight.

<Method for producing aqueous polyurethane resin dispersion>
Next, a method for producing an aqueous polyurethane resin dispersion will be described.
The method for producing an aqueous polyurethane resin dispersion of the present invention comprises at least a polyol (a), an acidic group-containing polyol (b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d). A step of reacting to obtain a polyurethane resin (A) (α);
A step (β) of neutralizing acidic groups of the polyurethane resin (A);
A step (γ) of dispersing the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond in an aqueous medium;
Can be included.

  The step (α) for obtaining the polyurethane resin (A) is preferably performed in the presence of oxygen in order to avoid unnecessary consumption of the polymerizable unsaturated bond. Moreover, it is desirable to add a polymerization inhibitor into the reaction system as necessary.

  The temperature of the process ((alpha)) which obtains a polyurethane resin (A) can be performed at 0-120 degreeC in order to avoid the unnecessary superposition | polymerization of a polymerizable unsaturated bond. Preferably it is 0-100 degreeC.

  Examples of the acidic group neutralizing agent that can be used in the step (β) of neutralizing the acidic group of the polyurethane resin (A) include trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, and N-phenyl. Organic amines such as diethanolamine, dimethylethanolamine, diethylethanolamine, N-methylmorpholine and pyridine; inorganic alkalis such as sodium hydroxide and potassium hydroxide, ammonia and the like. Among these, organic amines can be preferably used, more preferably tertiary amines can be used, and most preferably triethylamine can be used. Here, the acidic group of the polyurethane resin (A) refers to a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phenolic hydroxyl group, and the like.

  The amount of the acidic group neutralizing agent used is preferably such that the molar number is 0.8 to 1.5 with respect to the acidic groups of the polyurethane resin (A). If it is this range, it can avoid easily that the dispersibility to the water of a polyurethane resin (A) falls, or the storage stability of a water-based polyurethane resin aqueous dispersion falls, A water-based polyurethane resin A situation in which the odor of the water dispersion becomes strong can be easily avoided.

  In the step (γ) of dispersing the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond in the aqueous medium, as long as (A) and (B) can be dispersed in the aqueous medium. The method and the operation order are not particularly limited. For example, a method of mixing (B) with (A) and dispersing in an aqueous medium, a method of mixing (A) with (B) and dispersing in an aqueous medium, or (A) in an aqueous medium. A method of mixing and dispersing (B) after dispersion, a method of mixing and dispersing (A) after dispersing (B) in an aqueous medium, and (A) and (B) in an aqueous medium, respectively. The method of mixing after making it disperse | distribute, the method of mixing (B) and dispersing it in an aqueous medium at the time of (A) manufacture, etc. are mentioned.

  In the production of the polyurethane resin (A), when the primary hydroxyl group-containing (meth) acrylate (d) is subjected to a reaction as a mixture with the (meth) acrylate that is inert to the isocyanato group, the (meth) inactive to the isocyanato group. The acrylate is contained in the reaction product of the step (α) together with the polyurethane resin (A), subjected to the steps (β) and (γ), and polymerizable unsaturated in the final aqueous polyurethane resin dispersion. The compound (B) having a bond is constituted. In this case, an acidic group neutralizing agent can be added to the reaction product of step (α) and dispersed in an aqueous dispersion medium together with the compound (B) having a further polymerizable unsaturated bond. Before adding the compound (B) having a further polymerizable unsaturated bond, an aqueous medium may optionally be added.

  For the mixing, stirring, and dispersion, a known stirring device such as a homomixer or a homogenizer can be used. In addition, a hydrophilic organic solvent or water is added to the polyurethane resin (A) or the compound (B) having a polymerizable unsaturated bond in advance before mixing for viscosity adjustment, workability improvement, and dispersibility improvement. It can also be left.

  The step (γ) of mixing the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond is preferably performed in the presence of oxygen in order to avoid unnecessary consumption of the polymerizable unsaturated bond. Moreover, you may add a polymerization inhibitor as needed. The temperature when mixing the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond is preferably 0 to 100 ° C. in order to avoid unnecessary consumption of the polymerizable unsaturated bond, More preferably, it is carried out at 0 to 90 ° C, more preferably 0 to 80 ° C, and particularly preferably 50 to 70 ° C.

  In the production method of the present invention, the step (β) of neutralizing the acidic group of the polyurethane resin (A) and the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond are dispersed in an aqueous medium. Either step (γ) may be performed first, or may be performed simultaneously. In this case, (A) and (B), the aqueous medium and the acidic group neutralizing agent may be mixed at once, or the acidic group neutralizing agent may be mixed in advance with the aqueous medium and (B). And (A) may be mixed.

  The proportion of the polyurethane resin (A) in the aqueous polyurethane resin dispersion is preferably 5 to 60% by weight, more preferably 15 to 50% by weight, and still more preferably 25 to 40% by weight. The number average molecular weight is preferably 1,000 to 1,000,000.

  If necessary, the aqueous polyurethane resin dispersion of the present invention includes a thickener, a photosensitizer, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a plasticizer, a surface conditioner, and an anti-settling agent. Additives such as can also be added. An additive may be individual and may use multiple types together. The aqueous polyurethane resin dispersion of the present invention preferably contains substantially no protective colloid, emulsifier, or surfactant from the viewpoint of the hardness and chemical resistance of the resulting coating film.

<Photocurable composition>
The present invention also relates to a photocurable composition comprising the aqueous polyurethane resin dispersion and a photopolymerization initiator. As the photopolymerization initiator, known ones can be used. For example, a photocleavage type initiator that can be easily cleaved to form two radicals by irradiation with ultraviolet rays, or a hydrogen abstraction type initiator is used. be able to. These may be used in combination. Examples of these compounds include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, benzophenone, 2-chlorobenzophenone, p, p′-bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin n-propyl ether, Benzoin isopropyl ether, benzoin isobutyl ether, benzoin n-butyl ether, benzoin dimethyl ketal, thioxanthone, p-isopropyl-α-hydroxyisobutylphenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl -1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-phenylpro Down-1-one, 2,4,6, - trimethyl benzophenone, 4-methylbenzophenone, 2,2-dimethoxy-1,2-diphenyl-ethanone, and the like. Preferably, hydroxycyclohexyl phenyl ketone is used.

  When the photopolymerization initiator is added, it is preferably added after the step (γ) of dispersing the polyurethane resin (A) and the compound (B) having a polymerizable unsaturated bond in an aqueous medium. The amount of the photopolymerization initiator is preferably 0.5 to 5% by weight based on the total solid content of the aqueous polyurethane resin dispersion (including the compound (B) having a polymerizable unsaturated bond).

<Coating composition and coating agent composition>
The present invention also relates to a coating composition and a coating composition containing the aqueous polyurethane resin dispersion.
In addition to the aqueous polyurethane resin dispersion, other resins can be added to the coating composition and the coating composition of the present invention. Examples of other resins include polyester resins, acrylic resins, polyether resins, polycarbonate resins, polyurethane resins, epoxy resins, alkyd resins, and polyolefin resins. These may be single and may use multiple types together. The other resin preferably has one or more hydrophilic groups. Examples of the hydrophilic group include a hydroxyl group, a carboxy group, a sulfonic acid group, and a polyethylene glycol group.

  The other resin is preferably at least one selected from the group consisting of a polyester resin, an acrylic resin, and a polyolefin resin.

The polyester resin can be usually produced by an esterification reaction or an ester exchange reaction between an acid component and an alcohol component. As an acid component, the compound normally used as an acid component at the time of manufacture of a polyester resin can be used. As an acid component, an aliphatic polybasic acid, an alicyclic polybasic acid, an aromatic polybasic acid, etc. can be used, for example.
The hydroxyl value of the polyester resin is preferably about 10 to 300 mgKOH / g, more preferably about 50 to 250 mgKOH / g, and still more preferably about 80 to 180 mgKOH / g. The acid value of the polyester resin is preferably about 1 to 200 mgKOH / g, more preferably about 15 to 100 mgKOH / g, and still more preferably about 25 to 60 mgKOH / g.
The weight average molecular weight of the polyester resin is preferably 500 to 500,000, more preferably 1,000 to 300,000, and still more preferably 1,500 to 200,000.

As the acrylic resin, a hydroxyl group-containing acrylic resin is preferable. Hydroxyl group-containing acrylic resin is a hydroxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer, for example, in a solution polymerization method in an organic solvent, in water It can manufacture by making it copolymerize by known methods, such as an emulsion polymerization method.
The hydroxyl group-containing polymerizable unsaturated monomer is a compound having at least one hydroxyl group and one polymerizable unsaturated bond in one molecule. For example, (meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like and 2 to 8 carbon atoms. Monoesterified products of dihydric alcohols with these compounds; ε-caprolactone modified products of these monoesterified products; N-hydroxymethyl (meth) acrylamide; allyl alcohol; (meth) acrylates having a polyoxyethylene chain whose molecular ends are hydroxyl groups Etc.

The hydroxyl group-containing acrylic resin preferably has an anionic functional group. For the hydroxyl group-containing acrylic resin having an anionic functional group, for example, a polymerizable unsaturated monomer having an anionic functional group such as a carboxylic acid group, a sulfonic acid group, or a phosphoric acid group is used as one kind of the polymerizable unsaturated monomer. It can be manufactured by using.
The hydroxyl value of the hydroxyl group-containing acrylic resin is preferably about 1 to 200 mgKOH / g, more preferably about 2 to 100 mgKOH / g, and more preferably 3 to 60 mgKOH from the viewpoints of storage stability of the composition and water resistance of the resulting coating film. / G is more preferable.
When the hydroxyl group-containing acrylic resin has an acid group such as a carboxyl group, the acid value of the hydroxyl group-containing acrylic resin is preferably about 1 to 200 mgKOH / g from the viewpoint of water resistance of the resulting coating film, About 150 mgKOH / g is more preferable, and about 5 to 100 mgKOH / g is still more preferable.
The weight average molecular weight of the hydroxyl group-containing acrylic resin is preferably 1,000 to 200,000, more preferably 2,000 to 100,000, and still more preferably in the range of 3,000 to 50,000. is there.

  Examples of the polyether resin include polymers or copolymers having an ether bond, and examples include aromatics such as polyoxyethylene-based polyether, polyoxypropylene-based polyether, polyoxybutylene-based polyether, bisphenol A or bisphenol F. And polyethers derived from group polyhydroxy compounds.

  Examples of the polycarbonate resin include a polymer produced from a bisphenol compound, such as bisphenol A / polycarbonate.

  Examples of the polyurethane resin include resins having a urethane bond obtained by reacting various polyol components such as acrylic, polyester, polyether, and polycarbonate with polyisocyanate.

  Examples of the epoxy resin include a resin obtained by a reaction between a bisphenol compound and epichlorohydrin. Examples of bisphenol include bisphenol A and bisphenol F.

  Alkyd resins include polybasic acids such as phthalic acid, terephthalic acid and succinic acid and polyhydric alcohols, as well as fats and oils and fatty acids (soybean oil, linseed oil, coconut oil, stearic acid, etc.) and natural resins (rosin, succinic acid). Alkyd resin obtained by reacting a modifier such as

As the polyolefin resin, a polyolefin resin obtained by polymerizing or copolymerizing an olefin monomer with another monomer in accordance with a normal polymerization method is dispersed in water using an emulsifier, or the olefin monomer is appropriately replaced with another monomer. And a resin obtained by emulsion polymerization. In some cases, a so-called chlorinated polyolefin-modified resin in which the polyolefin resin is chlorinated may be used.
Examples of the olefin monomer include ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-hexene, Examples include α-olefins such as decene and 1-dodecene; conjugated dienes such as butadiene, ethylidene norbornene, dicyclopentadiene, 1,5-hexadiene, styrenes, and the like. These monomers are used alone. It may also be used in combination.
Examples of other monomers copolymerizable with olefinic monomers include vinyl acetate, vinyl alcohol, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, and the like. May be used alone or in combination.

  The coating composition and the coating composition of the present invention may contain a curing agent, whereby the coating film or multilayer coating film obtained by using the coating composition or the coating composition, the water resistance of the coating film Etc. can be improved.

  As the curing agent, for example, amino resin, polyisocyanate, blocked polyisocyanate, melamine resin, carbodiimide and the like can be used. A hardening | curing agent may be individual and may use multiple types together.

  Examples of the amino resin include a partial or completely methylolated amino resin obtained by a reaction between an amino component and an aldehyde component. Examples of the amino component include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and the like. Examples of the aldehyde component include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, and the like.

  Examples of the polyisocyanate include compounds having two or more isocyanato groups in one molecule, such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

  Examples of the blocked polyisocyanate include those obtained by adding a blocking agent to the polyisocyanate group of the aforementioned polyisocyanate. Examples of the blocking agent include phenols such as phenol and cresol, methanol, ethanol, and the like. Aliphatic alcohols, active methylenes such as dimethyl malonate and acetylacetone, mercaptans such as butyl mercaptan and dodecyl mercaptan, acid amides such as acetanilide and acetate amide, lactams such as ε-caprolactam and δ-valerolactam, Blocking agents such as acid imides such as succinimide and maleic imide, oximes such as acetoaldoxime, acetone oxime and methyl ethyl ketoxime, and amines such as diphenylaniline, aniline and ethyleneimine It is.

  Examples of the melamine resin include methylol melamines such as dimethylol melamine and trimethylol melamine; alkyl etherified products or condensates of these methylol melamines; condensates of alkyl etherified products of methylol melamine, and the like.

Coloring pigments, extender pigments, and glitter pigments can be added to the coating composition and coating agent composition of the present invention.
Examples of the color pigment include titanium oxide, zinc white, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment, quinacridone pigment, isoindoline pigment, selenium pigment, and perylene pigment. These may be single and may use multiple types together. In particular, it is preferable to use titanium oxide and / or carbon black as the color pigment.
Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white. These may be single and may use multiple types together. In particular, barium sulfate and / or talc are preferably used as extender pigments, and barium sulfate is more preferably used.
As the bright pigment, for example, aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, mica coated with titanium oxide or iron oxide, or the like may be used. it can.

  The coating composition and coating composition of the present invention include a thickener, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a plasticizer, a surface conditioner, an anti-settling agent, etc., if necessary. Usual paint additives can be contained. These may be single and may use multiple types together.

  Although the manufacturing method in particular of the coating composition and coating agent composition of this invention is not restrict | limited, A well-known manufacturing method can be used. In general, the coating composition and the coating composition are produced by mixing the aqueous polyurethane resin dispersion and the various additives described above, adding an aqueous medium, and adjusting the viscosity according to the coating method. The

Examples of the coating material of the coating composition or the coating material of the coating agent composition include metals, plastics, inorganic materials, and wood.
The coating composition and the coating agent composition of the present invention have high adhesion to plastic, and particularly high adhesion to poly (meth) acrylic resin and ABS resin. For this reason, as the material to be coated and the material to be coated, poly (meth) acrylate resin and / or ABS resin are preferable.

  Examples of the coating method of the coating composition or the coating method of the coating agent composition include bell coating, spray coating, roll coating, shower coating, and dip coating.

  The coating composition and the coating composition of the present invention are cured by irradiating active energy rays after coating or coating, evaporating at least a part of the aqueous medium under heating or non-heating. Is preferred. As the active energy ray, ultraviolet rays are preferable.

  As the ultraviolet light source, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a carbon arc lamp, a tungsten lamp, or the like can be used. The irradiation time can be appropriately changed depending on conditions such as the type of the compound having a polymerizable unsaturated bond, the type of the photopolymerization initiator, the coating thickness, and the ultraviolet ray source. From the viewpoint of workability, it is preferable to irradiate for 1 to 60 seconds. Further, for the purpose of completing the curing reaction, heat treatment can also be performed after irradiation with ultraviolet rays.

The irradiation amount of ultraviolet rays used when the composition of the present invention is cured is preferably 300 to 3,000 mJ / cm ² from the viewpoint of fast curability and workability.

  An electron beam or the like can also be used as the active energy ray. In the case of curing with an electron beam, a photopolymerization initiator may not be added, and an electron beam accelerator having an energy of 100 to 500 eV is preferably used.

  Although the thickness of the coating film after hardening is not restrict | limited, The thickness of 1-100 micrometers is preferable. More preferably, it is preferable to form a coating film having a thickness of 3 to 50 μm.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited to these.

[Example 1]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. From the reaction mixture, 55.7 g was extracted, cooled to 70 ° C., a mixture of dipentaerystol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 41 mgKOH / g, 5.4 g), and triethylamine (2. 9 g) was added and mixed. The reaction mixture was cooled to 45 ° C., and water (96.3 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Example 2]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. From the reaction mixture, 57.9 g was extracted, cooled to 70 ° C., a mixture of dipentaerystol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 41 mg KOH / g, 12.9 g), and triethylamine (2. 8g) was added and mixed. The reaction mixture was cooled to 45 ° C. and water (136 g) was slowly added with stirring to obtain an aqueous polyurethane resin dispersion.

[Example 3]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. 57.9 g was extracted from the reaction mixture, cooled to 70 ° C., and pentaerythritol tetraacrylate (PETA (4), 12.0 g) and triethylamine (2.7 g) were added and mixed. The reaction mixture was cooled to 45 ° C. and water (130 g) was slowly added with stirring to obtain an aqueous polyurethane resin dispersion.

[Example 4]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. 63.8 g was extracted from the reaction mixture, cooled to 70 ° C., and pentaerythritol triacrylate (PETA (3), 13.8 g) and triethylamine (3.2 g) were added and mixed. The reaction mixture was cooled to 45 ° C. and water (147 g) was slowly added with stirring to obtain an aqueous polyurethane resin dispersion.

[Example 5]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. 45.1 g of the reaction mixture was extracted, cooled to 70 ° C., and ditrimethylolpropane tetraacrylate (DTTA, 10.0 g) and triethylamine (2.2 g) were added and mixed. The reaction mixture was cooled to 45 ° C., and water (100 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Example 6]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = A polycarbonate diol obtained by reacting a polyol mixture of a 1: 1 molar ratio with a carbonate ester, 89.8 g), 2,2-dimethylolpropionic acid (DMPA, 31.4 g), and isophorone diisocyanate (IPDI) , 124 g) in N-ethylpyrrolidone (103 g) in the presence of dibutyltin dilaurate (0.4 g) at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.8 g) and 4-methoxyphenol (0.8 g) were added and the atmosphere was air. Furthermore, a mixture (DPHA, hydroxyl value 95 mgKOH / g, 397 g) of dipentaerystol hexaacrylate and dipentaerythritol pentaacrylate was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.24% by weight. 130 g of the reaction mixture was extracted and cooled to 70 ° C., and trimethylolpropane triacrylate (TMPTA, 14.0 g), tripropylene glycol diacrylate (TPGDA, 14.0 g), and triethylamine (5.2 g) were added. Added and mixed. The reaction mixture was cooled to 45 ° C., and water (304 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Example 7]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. Of the reaction mixture, 48.3 g was extracted, cooled to 70 ° C., and ethylene oxide-modified pentaerythritol pentaacrylate (EOPETA, tetraacrylate derived from alcohol obtained by adding 4 mol of ethylene oxide to 1 mol of pentaerythritol, 10.8 g). And triethylamine (2.3 g) were added and mixed. The reaction mixture was cooled to 45 ° C. and water (107 g) was slowly added with stirring to obtain an aqueous polyurethane resin dispersion.

[Example 8]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. From the reaction mixture, 32.4 g was extracted, cooled to 70 ° C., and added and mixed with polyethylene glycol diacrylate (PEGDA, number average molecular weight of polyethylene glycol moiety 400, 7.0 g) and triethylamine (1.7 g). . The reaction mixture was cooled to 45 ° C., and water (75.5 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Example 9]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate (PETA, hydroxyl value 188 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. From the reaction mixture, 55.7 g was extracted, cooled to 70 ° C., a mixture of dipentaerystol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 41 mgKOH / g, 5.4 g), and triethylamine (2. 9 g) was added and mixed. The reaction mixture was cooled to 45 ° C., and water (96.3 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 1]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 95 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. 60.4 g was extracted from the reaction mixture, cooled to 70 ° C., and triethylamine (2.9 g) was added and mixed. The reaction mixture was cooled to 45 ° C. and water (111 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 2]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = A polycarbonate diol obtained by reacting a 1: 1 molar ratio polyol mixture with a carbonate, 89.9 g), 2,2-dimethylolpropionic acid (DMPA, 31.3 g), and isophorone diisocyanate (IPDI). , 124 g) in N-ethylpyrrolidone (101 g) in the presence of dibutyltin dilaurate (0.3 g) in a nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.8 g) and 4-methoxyphenol (0.8 g) were added and the atmosphere was air. Further, a mixture of dipentaerystol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 58 mgKOH / g, 399 g) was added and heated at 90 ° C. for 7 hours. When the NCO group content was measured, it was 1.89% by weight, and 21% of NCO groups remained.

[Comparative Example 3]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = A polycarbonate diol obtained by reacting a polyol mixture of a 1: 1 molar ratio with a carbonate ester, 24.1 g), 2,2-dimethylolpropionic acid (DMPA, 8.4 g), and isophorone diisocyanate (IPDI) 33.6 g) in N-ethylpyrrolidone (25.1 g) in the presence of dibutyltin dilaurate (0.1 g) at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.2 g) and 4-methoxyphenol (0.2 g) were added and the atmosphere was air. Further, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA, hydroxyl value 58 mgKOH / g, 169 g) was added and heated at 90 ° C. for 7 hours. The NCO group content was measured and found to be 0.21% by weight. 60.4 g was extracted from the reaction mixture, cooled to 70 ° C., and triethylamine (1.8 g) was added and mixed. The reaction mixture was cooled to 45 ° C., and water (119 g) was slowly added with stirring to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 4]
In a reactor equipped with a stirrer and a heater, ETERNACOLL (registered trademark) PH100 (manufactured by Ube Industries; number average molecular weight 1054; hydroxyl value 106 mgKOH / g; polyol component is 1,5-pentanediol: 1,6-hexanediol = Polycarbonate diol (41.0 g) obtained by reacting a 1: 1 molar ratio polyol mixture with carbonate ester, 2,2-dimethylolpropionic acid (DMPA, 14.4 g), and isophorone diisocyanate (IPDI). , 56.7 g) in N-ethylpyrrolidone (45.9 g) in the presence of dibutyltin dilaurate (0.2 g) under nitrogen atmosphere at 80-90 ° C. for 3 hours. 2,6-Di-tert-butyl-4-methylphenol (0.4 g) and 4-methoxyphenol (0.4 g) were added and the atmosphere was air. Further, a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate (DPHA, hydroxyl value 188 mgKOH / g, 181 g) was added and heated at 90 ° C. for 7 hours. The NCO group content at the end of the urethanization reaction was 0.23% by weight. 60.4 g was extracted from the reaction mixture, cooled to 70 ° C., and triethylamine (2.9 g) was added and mixed. The reaction mixture was cooled to 45 ° C. and water (111 g) was slowly added while stirring to obtain an aqueous polyurethane resin dispersion.

[Sample preparation for pencil hardness and adhesion]
3% by weight / solid content of a polymerization initiator (IRGACURE500, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added to each of the aqueous polyurethane resin dispersions of Examples 1 to 9 and Comparative Examples 1 to 4, and the mixture was thoroughly stirred. Got. This was uniformly applied onto ABS resin and PMMA resin so that the film thickness after drying was about 20 μm. Subsequently, the coating film (before ultraviolet irradiation) was obtained by drying at 60 degreeC for 30 minutes. The obtained coating film was passed under a high-pressure mercury lamp (one time irradiation, ultraviolet ray irradiation amount 1000 mJ / cm ² ). The obtained polyurethane resin coating film was subjected to pencil hardness measurement and adhesion evaluation.

(Evaluation of hardness)
It evaluated by measuring the pencil hardness of a polyurethane resin coating film.
[Measurement of pencil hardness]
In the polyurethane resin coating film on the PMMA resin obtained above, the pencil hardness of the resin coating film was measured by a method based on JIS K 5600-5-4.

(Evaluation of adhesion)
The ABS resin and the PMMA resin polyurethane resin coating film obtained above were evaluated by a cross-cut peeling method. That is, 25 squares of 4 mm ² were prepared on a test piece with a cutter, and peelability was examined with a cellophane tape.

(Evaluation of storage stability)
The appearance of each of the aqueous polyurethane resin dispersions of Examples 1 to 9 and Comparative Examples 1 to 4 was observed 3 days after the production to confirm the storage stability. The evaluation criteria are as follows.
○: Aggregates are not seen.
X: Aggregates are observed.

The parts by weight in the table represent parts by weight of each compound when the total solid content in the resin is 100 parts by weight.
As for the pencil hardness in the table, for example, “H” indicates that the pencil of H is not damaged at all. “2H-3H” indicates that a 3H pencil is scratched or not scratched, and 2H is not scratched at all.
The adhesion in the table indicates the result of the peel test. “25/25” indicates that 25 squares are in close contact with each other in 25 squares after the test.

  The aqueous polyurethane resin dispersion of the present invention can be widely used as a raw material for paints and coating agents.

Claims (9)

An aqueous polyurethane resin dispersion in which at least a polyurethane resin (A) having a polymerizable unsaturated bond and a compound (B) having a polymerizable unsaturated bond are dispersed in an aqueous medium,
The polyurethane resin (A) having a polymerizable unsaturated bond comprises at least a polyol (a), an acidic group-containing polyol (b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d). It is obtained by reacting,
The total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 60 to 80% by weight of the entire resin solid content,
As a mixture of dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate having a primary hydroxyl group-containing (meth) acrylate (d) having a hydroxyl value of 80 to 120 mgKOH / g, a polyurethane resin (A) is obtained. Subjected to the reaction to obtain,
An aqueous polyurethane characterized in that the compound (B) having a polymerizable unsaturated bond has dipentaerythritol hexa (meth) acrylate contained in the mixture and a compound having a further polymerizable unsaturated bond Resin dispersion. An aqueous polyurethane resin dispersion in which at least a polyurethane resin (A) having a polymerizable unsaturated bond and a compound (B) having a polymerizable unsaturated bond are dispersed in an aqueous medium,
  The polyurethane resin (A) having a polymerizable unsaturated bond comprises at least a polyol (a), an acidic group-containing polyol (b), a polyisocyanate (c), and a primary hydroxyl group-containing (meth) acrylate (d). It is obtained by reacting,
  The total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 60 to 80% by weight of the entire resin solid content,
  In order to obtain a polyurethane resin (A) as a mixture of pentaerythritol tetra (meth) acrylate and pentaerythritol tri (meth) acrylate having a primary hydroxyl group-containing (meth) acrylate (d) having a hydroxyl value of 100 to 280 mgKOH / g. To the reaction of
  The compound (B) having a polymerizable unsaturated bond has pentaerythritol tetra (meth) acrylate contained in the mixture and a compound having a further polymerizable unsaturated bond.
An aqueous polyurethane resin dispersion characterized by the above. The aqueous polyurethane resin dispersion according to claim 1 or 2 , wherein the polyol (a) is a polycarbonate diol. The total amount of the primary hydroxyl group-containing (meth) acrylate (d) and the compound (B) having a polymerizable unsaturated bond is 65 to 75% by weight based on the entire resin solid content . 2. The aqueous polyurethane resin dispersion according to item 1 . The photocurable composition containing a photoinitiator and the aqueous polyurethane resin dispersion of any one of Claims 1-4 . The coating composition containing the water-based polyurethane resin dispersion of any one of Claims 1-4 . The coating composition according to claim 6 , which is for (meth) acrylic resin or acrylonitrile-butylene-styrene resin. The coating agent composition containing the water-based polyurethane resin dispersion of any one of Claims 1-4 . The coating agent composition according to claim 8 , which is for (meth) acrylic resin or acrylonitrile-butylene-styrene resin.