JP2017066358A - Polyurethane resin composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane resin composition which can be produced in the presence of an inert gas and gives a coating film having high hardness.SOLUTION: The polyurethane resin composition of the present invention contains at least a polyurethane resin (A) and a radically polymerizable compound (B). The polyurethane resin (A) contains, as constituents, a polyester polyol (a) containing at least a repeating unit of formula (1) [where Ris a divalent organic group which may be interrupted by one or more selected from the group consisting of an ester bond, an ether bond, and a carbonate bond] and a polyisocyanate (b).SELECTED DRAWING: None

Description

  The present invention relates to a polyurethane resin composition and a method for producing the same.

  Polycarbonate polyol is a useful compound that becomes a raw material for producing a polyurethane resin used for a rigid foam, a flexible foam, a paint, an adhesive, a synthetic leather, an ink binder and the like by reaction with an isocyanate compound. Moreover, it is known that the coating film obtained by apply | coating the aqueous polyurethane resin dispersion which used polycarbonate polyol as the raw material is excellent in light resistance, heat resistance, hydrolysis resistance, and oil resistance (patent document 1).

  Since radically polymerizable compounds are excellent in curability even when irradiated with active energy rays other than heating, they are generally recognized as having features from the viewpoint of productivity and energy saving. In addition, the active energy ray-curable resin composition containing a radical polymerizable compound is used in the light of such properties, such as coatings for metal, various coatings for plastic films, various coatings for woodwork, printing inks, adhesives, etc. It is used as an active ingredient. As an active energy ray-curable resin composition containing such a radically polymerizable compound, an energy ray-curable aqueous resin composition containing an aqueous urethane resin and a (meth) acrylate compound is known, and adhesion is known. It is known to improve the property, chemical resistance, stain resistance, and flex resistance (Patent Document 2).

  In addition, introduction of a (meth) acryloyl group as an active energy ray-curable functional group into a urethane resin has been performed. For example, a urethane resin obtained by reacting an isocyanate compound with at least one ethylenically unsaturated compound containing at least two reactive groups capable of reacting with an isocyanate group and at least one ethylenically unsaturated group It is known to give films having very poor moisture release properties in compositions (Patent Document 3).

JP-A-10-120757 JP 2008-248014 A Special table 2014-501825 gazette

  However, when the energy beam curable aqueous resin composition described in Patent Document 2 is used, various coatings such as metal paints, various plastic film overcoat agents, woodwork paints, printing inks, adhesives, etc. When used with an active ingredient, there was a problem that the hardness of the coating film was not sufficient. Further, the production of the urethane resin composition described in Patent Document 3 needs to be carried out in the presence of a flammable gas, and there is a concern that the danger during production increases. When the described urethane resin was produced in an inert gas atmosphere, there was a problem that it could not be produced by gelation.

  Therefore, this invention makes it a subject to provide the polyurethane resin composition which can be manufactured in inert gas presence and gives the coating film with high hardness.

［式中、Ｒ^１は、エステル結合、エーテル結合及びカーボネート結合からなる群より選ばれる１以上で中断されていてもよい二価の炭化水素基である。］
ポリイソシアネート（ｂ）とを構成成分とするポリウレタン樹脂組成物とすることで前記課題を解決できるとことを見出した。 As a result of various investigations, the present inventors have found that the polyurethane resin component composition contains at least the polyurethane resin (A) and the radical polymerizable compound (B), and the polyurethane resin (A) is at least A polyester polyol (a) comprising a repeating unit of formula (1);

[Wherein, R ¹ represents a divalent hydrocarbon group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]
It discovered that the said subject could be solved by setting it as the polyurethane resin composition which uses polyisocyanate (b) as a structural component.

［式中、Ｒ^１は、エステル結合、エーテル結合及びカーボネート結合からなる群より選ばれる１以上で中断されていてもよい二価の炭化水素基である。］
の繰り返し単位を含むポリエステルポリオール（ａ）と、
ポリイソシアネート（ｂ）とを構成成分とする、ポリウレタン樹脂組成物。
［２］式（１）におけるＲ^１がＣ_２〜Ｃ_２０のアルキレン基である、［１］のポリウレタン樹脂組成物。
［３］式（１）における−Ｏ−Ｒ^１−Ｏ−が、少なくとも一種の式（２）：

［式中、Ｒ^２は、Ｃ_２〜Ｃ_２０の非環式アルキレン基である。］
の単位を含む、［１］又は［２］のポリウレタン樹脂組成物。
［４］式（１）における−Ｏ−Ｒ^１−Ｏ−が、少なくとも一種の式（３）：

［式中、Ｒ^３は、Ｃ_２〜Ｃ_２０の環式アルキレン基である。］
の単位を含む、［１］〜［３］のいずれかのポリウレタン樹脂組成物。
［５］ポリウレタン樹脂（Ａ）が、［１］〜［４］のいずれかに記載のポリエステルポリオール（ａ）と、ポリイソシアネート（ｂ）と、酸性基含有ポリオール（ｃ）とを構成成分とする、［１］〜［４］のいずれかのポリウレタン樹脂組成物。
［６］更に、水系媒体（Ｃ）を含有する、［１］〜［５］のいずれかのポリウレタン樹脂組成物。
［７］更に、光重合開始剤を含有する、［１］〜［６］のいずれかのポリウレタン樹脂組成物である。
［８］［１］〜［７］のいずれかのポリウレタン樹脂組成物及び着色剤を含有する塗料組成物。
［９］［１］〜［７］のいずれかのポリウレタン樹脂組成物を含有し、着色剤を含まないコーティング組成物。
［１０］少なくとも、式（１）：

［式中、Ｒ^１は、エステル結合、エーテル結合及びカーボネート結合からなる群より選ばれる１以上で中断されていてもよい二価の炭化水素基である。］
の繰り返し単位を含むポリエステルポリオール（ａ）と、ポリイソシアネート（ｄ）とを反応させてポリウレタン樹脂（Ａ）を得る工程（α）、及び
ポリウレタン樹脂（Ａ）とラジカル重合性化合物（Ｂ）とを混合する工程（γ）を含む、［１］〜［６］のいずれかのポリウレタン樹脂組成物の製造方法。 Specifically, the present invention is as follows.
[1] A polyurethane resin composition containing at least a polyurethane resin (A) and a radical polymerizable compound (B),
The polyurethane resin (A) has at least the formula (1):

[Wherein, R ¹ represents a divalent hydrocarbon group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]
A polyester polyol (a) containing a repeating unit of:
A polyurethane resin composition comprising polyisocyanate (b) as a constituent component.
[2] The polyurethane resin composition according to [1], wherein R ¹ in the formula (1) is a C _{2 to} C ₂₀ alkylene group.
[3] —O—R ¹ —O— in Formula (1) is at least one type of Formula (2):

[Wherein R ² is a C _{2 to} C ₂₀ acyclic alkylene group. ]
The polyurethane resin composition according to [1] or [2], comprising the unit of:
[4] In formula (1), —O—R ¹ —O— is at least one type of formula (3):

[Wherein R ³ is a C _{2 to} C ₂₀ cyclic alkylene group. ]
The polyurethane resin composition according to any one of [1] to [3], comprising a unit of
[5] The polyurethane resin (A) comprises the polyester polyol (a) according to any one of [1] to [4], the polyisocyanate (b), and the acidic group-containing polyol (c) as constituent components. , [1] to [4].
[6] The polyurethane resin composition according to any one of [1] to [5], further comprising an aqueous medium (C).
[7] The polyurethane resin composition according to any one of [1] to [6], further containing a photopolymerization initiator.
[8] A coating composition containing the polyurethane resin composition according to any one of [1] to [7] and a colorant.
[9] A coating composition containing the polyurethane resin composition according to any one of [1] to [7] and not containing a colorant.
[10] At least the formula (1):

[Wherein, R ¹ represents a divalent hydrocarbon group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]
A step (α) of obtaining a polyurethane resin (A) by reacting a polyester polyol (a) containing a repeating unit of the above and a polyisocyanate (d), and a polyurethane resin (A) and a radically polymerizable compound (B). The manufacturing method of the polyurethane resin composition in any one of [1]-[6] including the process ((gamma)) to mix.

  The present invention can provide a polyurethane resin composition that can be produced in the presence of an inert gas and that provides a coating film having high hardness.

(Polyurethane resin (A))
The polyurethane resin contains a polyester polyol (a) containing at least a repeating unit of the formula (1) and a polyisocyanate (b) as constituent components.

［式中、Ｒ^１は、エステル結合、エーテル結合及びカーボネート結合からなる群より選ばれる１以上で中断されていてもよい二価の炭化水素基である。］ <Polyester polyol (a)>
The polyester polyol (a) (hereinafter also referred to as “(a)”) includes at least a repeating unit of the formula (1). The polyester polyol has a hydroxyl group as a constituent component of the polyester polyol at the end of the molecule.

[Wherein, R ¹ represents a divalent hydrocarbon group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]

<< Repeating unit of formula (1) >>
In the formula (1), the arrangement of the two keto groups bonded to the carbon-carbon double bond may be cis or trans.

R ¹ is a divalent organic group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. Such a divalent organic group is preferably a hydrocarbon group optionally having a heteroatom such as oxygen or nitrogen. In the divalent organic group, the main chain is preferably interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. In this specification, the main chain refers to an atomic chain that connects both ends of a group with a minimum number of atoms.

R ¹ includes a C _{2 to} C ₂₀ alkylene group, and specifically, may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond, and C _{2 to} C ₂₀ non- include divalent organic group containing one or more groups selected from the group consisting of a divalent group having a cyclic alkylene and C ₂ -C ₂₀ ring structure. Having a ring structure is a structure in which any —CH ₂ — constituting the carbon chain of the main chain is replaced by a ring structure. The ring structure may be an alicyclic structure such as cyclohexanediyl or an aromatic ring structure such as phenylene.

C ₂ -C ₂₀ acyclic alkylene groups are straight-chain or branched. The linear C ₂ -C ₂₀ acyclic alkylene group is preferably a C ₂ -C ₉ linear alkylene such as ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, etc. . Branched C ₂ -C ₂₀ acyclic alkylene groups are 2-methyl-1,3-propanediyl, 2-methyl-1,5-pentanediyl, 3-methyl-1,5-pentanediyl, 2-methyl- C ₃ -C ₁₀ branched alkylene such as 1,9-nonanediyl is preferred.

Examples of the divalent organic group having a C _{2 to} C ₂₀ ring structure include a C _{2 to} C ₂₀ aliphatic cyclic group (cyclic alkylene group) and a C _{2 to} C ₂₀ aromatic cyclic group (ring Arylene groups), alkylene interrupted by one or more cyclic groups selected from the group consisting of C ₂ -C ₂₀ aliphatic cyclic groups and C ₂ -C ₂₀ aromatic cyclic groups. It is done.

  The aliphatic cyclic group is monocyclic or polycyclic, may have an unsaturated bond, and may have one or more heterocyclic atoms (oxygen, nitrogen, etc.) It is a group. Examples of such a cyclic group include cyclohexanediyl, cyclopentanediyl, 1,4-dioxane-2,5-diyl, norbornane-2,7-diyl, tetrahydrofurandiyl and the like. Examples of the aromatic cyclic group include phenylene, naphthalene, thiophene, pyridyl, pyrrole, and pyrimidyl.

  As alkylene groups interrupted by cyclic alkylene groups, methylene-cyclohexanediyl-methylene, methylene-cyclopentanediyl-methylene, methylene-norbornane-2,7-diyl-methylene, methylene-1,4-dioxane-2,5 -Alkylene-cycloalkylene-alkylene such as -diyl-methylene and the like. Examples of the alkylene group interrupted by the cyclic arylene group include alkylene-arylene-alkylene such as methylene-phenlene-methylene.

［式中、Ｒ^２は、Ｃ_２〜Ｃ_２０の非環式アルキレン基である。］

［式中、Ｒ^３は、Ｃ_２〜Ｃ_２０の環式アルキレン基である。］ R ¹ is preferably a C _{2 to} C ₂₀ acyclic alkylene or a hydrocarbon group interrupted at least by a carbonate bond. When R ¹ is a hydrocarbon group interrupted by at least a carbonate bond, —O—R ¹ —O— is one or more units selected from the group consisting of the following formulas (2) and (3) A group containing Here, in the unit of formula (2) and (3), oxygen atoms constituting the carbonate bond (-O-C (= O) -O-) has the ^{R 1} in ^{the -O-R} 1 -O- It is preferably not a bonded oxygen atom.

[Wherein R ² is a C _{2 to} C ₂₀ acyclic alkylene group. ]

[Wherein R ³ is a C _{2 to} C ₂₀ cyclic alkylene group. ]

The C _{2 to} C ₂₀ acyclic alkylene group in R ² includes preferable ones and is as described above. The C ₂ -C ₂₀ cyclic alkylene group in R ³ includes the preferred ones and is as described above.

In addition, when —O—R ¹ —O— includes one or more units selected from the group consisting of the unit of formula (2) and the unit of formula (3), as a further unit, the formula: —R ² Units of —O—C (═O) —O— and units of the formula: —R ³ —O—C (═O) —O—, formulas: —R ² —O— and formulas: —R One or more further units selected from the group consisting of units of ³ -O- may be included. In the above formula, each R ² may be the same or different from each other. In the above formula, each R ³ may be the same or different from each other. The unit of formula (2), the unit of formula (3) and further units may be joined in any order, provided that no oxygen-oxygen bond (—O—O—) is formed.

Accordingly, —O—R ¹ —O— preferably contains one or more units selected from the group consisting of the unit of formula (2) and the unit of formula (3), and the unit of formula (2) and One or more units selected from the group consisting of units of formula (3), units of formula: —R ² —O—C (═O) —O—, and formula: —R ³ —O—C (= O) -O- units, the ^formula: -R 2 -O- units, and the ^formula: contain the one or more further units selected from the group consisting of -R 3 -O- unit further Preferably, it consists of a unit of the formula (2) and a unit of the formula: —R ² —O—C (═O) —O—, or a unit of the formula (2) and a formula: —R ² —O—C It consists of a unit of (═O) —O— and a unit of formula: —R ² —O—, or a unit of formula (3) and a formula: —R ³ —O—C (═O) —O—. Or the unit of formula (3) and the formula: And ^{R 3 -O-C (= O} ) -O- units, the ^formula: particularly preferred that consisting of -R 3 -O- units, and units of formula (2), the formula: ^-R 2 -O A unit of —C (═O) —O—, a unit of formula: —R ² —O—, a unit of formula (3), and a unit of formula: —R ³ —O—C (═O) —O—. It is particularly preferred that the unit consists of a unit and a unit of the formula: —R ³ —O—.

  The number average molecular weight of (a) is not particularly limited, but is preferably 400 to 8,000. When the number average molecular weight of (a) is 400 or more, the performance as a soft segment is improved, and cracks tend not to occur when a coating film is formed using the obtained polyurethane resin composition. When the number average molecular weight of (a) is 8,000 or less, the reactivity between (a) and isocyanate (b) described later is improved, the time required for the production process of the urethane resin is shortened, and the reaction proceeds sufficiently. However, the viscosity of the polyester polyol (a) tends to be low and the handling becomes easy. The number average molecular weight of (a) is more preferably 400 to 4,000.

  In this specification, the number average molecular weight of the polyester polyol is a number average molecular weight calculated based on a hydroxyl value measured according to JIS K 1577.

The component of the polyester polyol (a) having such R ¹ contains one or more polyols and one or more unsaturated bonds selected from the group consisting of maleic anhydride; maleic acid ester and fumaric acid ester. A dicarboxylic acid. From the viewpoint of easy production, the component of the polyester polyol (a) is one or more polyols (provided that they are not “acidic group-containing polyol compound (c)” and “other polyols” described later). And maleic anhydride. The reaction amount ratio between the unsaturated bond-containing dicarboxylic acid and the one or more polyols is not particularly limited, and can be 1: 1.1 to 1:10.

  The one or more polyols (provided that they are not “acidic group-containing polyol (c)” and “other polyol (d)” described later) are not particularly limited, but include aliphatic polyols and alicyclic rings. Examples thereof include a polyol having a structure, a polycarbonate polyol, a polyester polyol, a polyether polyol, and a polyether polyester polyol.

  The aliphatic polyol is not particularly limited, but 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Linear aliphatic diols such as octanediol and 1,9-nonanediol; 2-methyl-1,3-propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol And branched chain aliphatic diols such as 2-methyl-1,9-nonanediol.

  The polyol having an alicyclic structure is not particularly limited, but 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cyclohexane An alicyclic structure in the main chain such as heptanediol, 2,5-bis (hydroxymethyl) -1,4-dioxane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 1,4-bis (hydroxyethoxy) cyclohexane The diol which has.

  As the polycarbonate polyol, polycarbonate diol is preferable. The polycarbonate diol is not particularly limited, but an aliphatic polycarbonate diol such as polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyhexamethylene carbonate diol; aromatic polycarbonate diol such as poly 1,4-xylylene carbonate diol A polycarbonate diol comprising a plurality of types of aliphatic monomer diols and carbonates as constituent components; a polycarbonate diol comprising aliphatic monomer diols, aromatic monomer diols and carbonates as constituent components; aliphatic monomer diols and alicyclic monomers Polycarbonate diol containing diol and carbonate as constituents; and Polycarbonate diol containing aliphatic monomer diol, dimer diol and carbonate as constituents Copolycarbonate diol such as ball sulfonate diol.

  Examples of the aliphatic monomer diol include, but are not limited to, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and the like.

  The alicyclic monomer diol is not particularly limited, but 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cycloheptane Has an alicyclic structure in the main chain such as diol, 2,5-bis (hydroxymethyl) -1,4-dioxane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 1,4-bis (hydroxyethoxy) cyclohexane Diol etc. are mentioned.

  The aromatic monomer diol is not particularly limited, and examples thereof include 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,4-dihydroxybenzene and the like.

  Polyester monomer diol is not particularly limited, but polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene sebacate diol, Examples include 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.

  Examples of the polyether monomer diol include, but are not limited to, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide, ethylene oxide and butylene oxide random copolymers, and block copolymers.

  Although it does not restrict | limit especially as a polyester polyol, Polyester polyol of hydroxycarboxylic acid and diol, such as polyester polyol of 6-hydroxycaproic acid and hexanediol, Dicarboxylic acid and diol, such as polyester polyol of adipic acid and hexanediol, Polyester polyols and the like.

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

  The polycarbonate polyol may be a polycarbonate diol described in JP-A-2014-210921.

  Polycarbonate polyol is preferred and polycarbonate diol is more preferred in terms of improving adhesion to the substrate. A polycarbonate diol containing a monomer diol containing an aliphatic monomer diol and a carbonate ester as constituents is preferred because the urethane resin has a low viscosity and is easy to handle. A polycarbonate diol having an aliphatic monomer diol, an alicyclic monomer diol, and a carbonate as a constituent component is preferable in that the resulting coating film has higher hardness.

<(B) Polyisocyanate>
(B) Polyisocyanate is a compound having two isocyanato groups per molecule. (B) The polyisocyanate may have three or more isocyanate groups per molecule as long as the (A) polyurethane resin does not gel. (B) As polyisocyanate, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned.

  The aromatic polyisocyanate is not particularly limited, but 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.

  The aliphatic polyisocyanate is not particularly limited, but ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 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.

  The alicyclic polyisocyanate is not particularly limited, but is isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2 -Isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

  An alicyclic polyisocyanate is preferable from the viewpoint that the durability of the obtained coating film is increased and that the viscosity is high when the coating film is produced. Isophorone diisocyanate (IPDI) and 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI) are particularly preferred because the reaction can be easily controlled.

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

<Additional components constituting polyurethane resin (A)>
In addition to the polyester polyol (a) and the polyisocyanate (b), the polyurethane resin (A) may contain a further component as a constituent component. Examples of the polyurethane resin (A) having such a further component as a constituent component include a polyurethane resin having a polyurethane prepolymer (A1) and a chain extender (D) as constituent components. Here, as the polyurethane prepolymer (A1), a polyurethane prepolymer comprising polyester polyol (a) and polyisocyanate (b) as constituent components; polyester polyol (a), acidic group-containing polyol compound (c), Polyurethane prepolymer comprising polyisocyanate (b) as a constituent component; polyester polyol (a), acidic group-containing polyol compound (c), polyisocyanate (b), and other polyol (d) as constituent components And a polyurethane prepolymer. The acidic group-containing polyol compound (c) is not other polyol (d). The other polyol (d) is not an acidic group-containing polyol compound (c).

<< Acid group-containing polyol compound (c) >>
The acidic group-containing polyol compound (c) (hereinafter sometimes referred to as “(c)”) 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. (C) is preferably one containing a compound having two hydroxyl groups and one carboxy group in one molecule. (C) may be used individually by 1 type and may use multiple types together.

  Specific examples of (c) include dimethylol alkanoic acids such as 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid; N, N-bishydroxyethylglycine, N, N-bishydroxy Examples include ethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid and the like. Among these, from the viewpoint of easy availability, C 4-12 alkanoic acid (dimethylol alkanoic acid) containing two methylol groups is preferred, and 2,2-dimethylolpropionic acid is particularly preferred.

  The total number of hydroxyl equivalents of the polyester polyol (a), acidic group-containing polyol compound (c) and other polyol (d) is preferably 150 to 600. When the total number of hydroxyl equivalents of the polyester polyol (a), the acidic group-containing polyol compound (c) and the other polyol (d) is 150 or more, the polyurethane resin composition is easily dispersed in the aqueous medium. When the total number of hydroxyl equivalents of the polyester polyol (a), the acidic group-containing polyol compound (c), and the other polyol (d) is 600 or less, the resulting coating film may have high hardness. The total number of hydroxyl equivalents of the polyester polyol (a), acidic group-containing polyol compound (c) and other polyol (d) is determined by the dispersibility of the resulting polyurethane resin composition in an aqueous medium and the coating obtained by coating. From the point of the hardness of a film | membrane, Preferably it is 150-600, More preferably, it is 200-500, Most preferably, it is 220-400.

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 above formula (2), M is [[number of hydroxyl equivalents of polyester polyol (a) × number of moles of polyester polyol (a)] + [number of hydroxyl equivalents of acidic group-containing polyol compound (c) × acidic group-containing polyol. Number of moles of compound (c)] + [number of hydroxyl equivalents of other polyol (d) × number of moles of other polyol (d)]].

<< Other polyol (d) >>
Examples of the other polyol (d) (hereinafter sometimes referred to as “(d)”) include, for example, a high molecular weight polyol and a low molecular weight polyol. As the other polyol, a low molecular weight diol is preferable because the hardness of the coating film obtained using the polyurethane resin composition is increased.

  Although there is no restriction | limiting in particular as high molecular weight polyol, A number average molecular weight is 400-4,000, and polycarbonate diol, polyester diol, polyether diol, etc. are mentioned. The polycarbonate diol is not particularly limited, but specifically, an aliphatic polycarbonate diol such as polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyhexamethylene carbonate diol; poly 1,4-xylylene carbonate diol, etc. Aromatic polycarbonate diols; polycarbonate diols comprising two or more aliphatic diols and carbonates as constituents; polycarbonate diols comprising aliphatic diols, aromatic diols and carbonates as constituents, aliphatic diols and dimer diols And copolymer polycarbonate diols such as polycarbonate diols, and the like. Examples of the aliphatic diol include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and the like. Examples of the aromatic diol include 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,4-dihydroxybenzene and the like. Polyester diol is not particularly limited, and specifically, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene seba Examples thereof include keto diol, polybutylene sebacate diol, poly-ε-caprolactone diol, poly (3-methyl-1,5-pentylene adipate) diol, polycondensate of 1,6-hexanediol and dimer acid. . The polyether diol is not particularly limited, and specific examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide, random copolymer and block copolymer of ethylene oxide and butylene oxide, and the like. . Further, a polyether polyester polyol having an ether bond and an ester bond may be used.

The low molecular weight diol is not particularly limited, but has a number average molecular weight of 60 or more and less than 400, and includes 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 -Aliphatic diols having 2 to 9 carbon atoms such as hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, diethylene glycol, triethylene glycol, tetraethylene glycol; 1,4-cyclohexanedimethanol 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-bis (hydroxy And diols having an alicyclic structure having 6 to 12 carbon atoms such as (ciethyl) cyclohexane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 2,5-bis (hydroxymethyl) -1,4-dioxane, and the like. it can. Furthermore, low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol, and sorbitol may be used as the low molecular weight diol.
As the other polyol (d), one type may be used alone, or a plurality of types may be used in combination.

<< Chain extender (D) >>
The chain extender (D) has reactivity with the isocyanate group of the polyurethane prepolymer (A1). As chain extender (D), ethylenediamine, 1,4-tetramethylenediamine, 2-methyl-1,5-pentanediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,4-hexa Amines such as methylenediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl) cyclohexane, xylylenediamine, piperazine, 2,5-dimethylpiperazine, diethylenetriamine, triethylenetetramine Compounds; Diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol; polyalkylene glycols typified by polyethylene glycol; water Etc. Gerare, amine compounds are preferable, diamine compounds are more preferred, a diamine compound having two primary amino groups in a molecule is particularly preferable. That is, when the polyurethane resin composition contains water as the aqueous medium (C), water as the aqueous medium (C) also serves as a chain extender.
A chain extender (D) may be used independently and may use 2 or more types together.

<Conditions for obtaining polyurethane resin (A)>
As a polyol component, when it consists of polyester polyol (a), acidic group containing polyol compound (c), and other polyol (d) depending on the case, polyester polyol (a), acidic group containing polyol compound (c), and other polyol When the total amount with (d) is 100 parts by weight, the proportion of the polyester polyol (a) is preferably 20 to 80 parts by weight, more preferably 30 to 70 parts by weight, and particularly preferably 40 to 60 parts by weight. . The proportion of the acidic group-containing polyol compound (c) is preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight, and particularly preferably 5 to 15 parts by weight. The proportion of the other polyol (d) is preferably 0 to 20 parts by weight, more preferably 0 to 10 parts by weight, and particularly preferably 0 to 5 parts by weight.

  If the ratio of the polyester polyol (a) is in the above-described range, the hardness tends to increase. If the ratio of the acidic group-containing polyol compound (c) is not more than the upper limit of the above range, the water resistance of the coating film obtained by applying the polyurethane resin tends to be high. If the ratio of (c) is more than the lower limit of the said range, when a polyurethane resin composition further contains an aqueous medium (C), the dispersibility of the polyurethane resin in an aqueous medium will become favorable. If the ratio of other polyol (d) is below the upper limit of the said range, when a polyurethane resin composition further contains an aqueous medium (C), the dispersibility to the aqueous medium of a polyurethane resin will become favorable.

  A polyol component comprising a polyester polyol (a) and an acidic group-containing polyol compound (c), or a polyol component comprising a polyester polyol (a), an acidic group-containing polyol compound (c) and another polyol (d). The ratio of the number of moles of isocyanato groups of the polyisocyanate (b) to the number of moles of all hydroxyl groups is preferably 1.1 to 2.5. By setting the molar ratio of the hydroxyl group of the polyol component to 1.1 or more, the polyurethane prepolymer (A1) having no isocyanate group at the molecular end increases and the number of molecules that do not react with the chain extender (D) increases. It is easy to avoid the problem that the strength of the coating film obtained by applying the aqueous polyurethane resin dispersion of the invention is lowered. Moreover, by making the molar ratio of the hydroxyl group of the polyol component 2.5 or less, a large amount of unreacted polyisocyanate (b) remains in the reaction system and reacts with the chain extender (D) or reacts with water. As a result, molecular elongation occurs, so that it is easy to avoid the problems that the production of the polyurethane resin composition of the present invention becomes difficult and the storage stability is lowered. The ratio of the number of moles of isocyanato groups in the polyisocyanate (b) to the number of moles of all hydroxyl groups in the polyol component is preferably 1.15 to 2.2, and particularly preferably 1.2 to 2.0.

  When the polyester polyol (a), the acidic group-containing polyol compound (c), and the polyisocyanate (b) are reacted to obtain the polyurethane prepolymer (A1), (a) and (b) are in any order. You may make it react with (c), and you may make it react with (b) after mixing (a) and (c). When the polyester polyol (a), acidic group-containing polyol compound (c), polyisocyanate (b), and other polyol (d) are reacted to obtain the polyurethane prepolymer (A1), (A), (c) and (d) may be reacted with (b) in any order, and (a), (c) and (d) may be mixed and then reacted with (b).

  In the reaction for obtaining the polyurethane resin (A) and the polyurethane prepolymer (A1), a catalyst may be used. The catalyst is not particularly limited, but metals such as tin (tin) catalysts (trimethyltin laurate, dibutyltin dilaurate, etc.) and lead catalysts (lead octylate, etc.), salts of organic and inorganic acids, and organic metals Derivatives, amine catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.), diazabicycloundecene catalysts, and the like can be given. As the catalyst, dibutyltin dilaurate is preferable from the viewpoint of reactivity.

  The reaction temperature for reacting the polyol component with the polyisocyanate is not particularly limited, but is preferably 40 to 150 ° C. If the reaction temperature is too low, the raw material may not be dissolved, and the resulting polyurethane prepolymer (A1) may have a high viscosity and may not be sufficiently stirred. If the reaction temperature is too high, problems such as side reactions may occur. The reaction temperature is more preferably 60 to 120 ° C. The reaction of the polyester polyol (a), the acidic group-containing polyol compound (c), the polyisocyanate compound (b) and any other polyol (d) may be carried out without a solvent or by adding an organic solvent. 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 they can be removed from the polyurethane prepolymer under reduced pressure. Further, N-methylpyrrolidone and N-ethylpyrrolidone are preferable because they function as a film-forming aid when a coating film is produced from the obtained aqueous polyurethane resin dispersion. The addition amount of the organic solvent is preferably 0.1 to 2.0 times on a weight basis with respect to the total amount of the polyester polyol (a), the acidic group-containing polyol compound (c) and the other polyol (d). Yes, more preferably 0.15 to 0.8 times.

  When the polyurethane resin composition further contains an aqueous medium (C), the acid value of the polyurethane prepolymer (A1) is preferably 10 to 55 mgKOH / g, more preferably 15 to 50 mgKOH / g, and particularly preferably. Is 20-40 mg KOH / g. If the acid value is not less than the lower limit of the above range, the dispersibility in an aqueous medium tends to be good, and if the acid value is not less than the lower limit of the above range, the water resistance of the resulting polyurethane resin coating is likely to increase.

In the present specification, the “acid value of the polyurethane prepolymer (A1)” means that the solvent used for producing the polyurethane prepolymer (A1) and the polyurethane prepolymer (A1) are dispersed in an aqueous medium. It is the content of acid groups in the so-called solid content excluding the neutralizing agent.
Specifically, the acid value of the polyurethane prepolymer (A1) can be derived from the following formula (3).
[Acid value of polyurethane prepolymer (A1)] = [number of moles of acidic group-containing polyol compound (c)] × 56.11 / [polyester polyol (a), acidic group-containing polyol compound (c), other polyols ( d) and the total weight of polyisocyanate (b)] (3)

  The reaction amount of the chain extender (D) is preferably equal to or less than the equivalent of the isocyanato group serving as a chain extension origin in the urethane prepolymer to be obtained, and more preferably 0.70 to 0.98 equivalent of the isocyanato group. preferable. When the chain extender (D) is reacted at an equivalent amount or less of the isocyanato group, the molecular weight of the chain-extended polyurethane resin does not decrease too much, and the strength of the resulting coating film is improved. The chain extender (D) may be reacted either after the polyurethane prepolymer is dispersed in water or during the dispersion. When the polyurethane prepolymer (A1) and the chain extender (D) are reacted to obtain a polyurethane resin, the reaction temperature between the polyurethane prepolymer (A1) and the chain extender (D) is, for example, 0 to 80 ° C., Preferably it is 0-60 degreeC.

(Radical polymerizable compound (B))
Although it will not specifically limit if a radically polymerizable compound (B) is a compound which has radical polymerizability, The compound which has a vinyl group is mentioned, The compound which has a (meth) acryloyl group is preferable. The “(meth) acryloyl compound” includes at least one of a compound having an acryloyl group and a compound having a methacryloyl group. (Meth) acryloyl compounds include monomers (meth) acrylate compounds, urethane-based (meth) acryloyl compounds having a urethane bond in the molecule (polyurethane (meth) acrylate compounds), and ester-based compounds having an ester bond in the molecule ( (Meth) acryloyl compounds (polyester (meth) acrylate compounds), alkylene (meth) acryloyl compounds (polyalkylene (meth) acrylate compounds) in which hydrogen atoms of hydrocarbons such as alkanes are substituted with (meth) acryloyl groups, etc. Can be mentioned.

  Mono (meth) acrylate compounds such as mono (meth) acrylate; di (meth) acrylate, tri (meth) acrylate, tetra (meth) acrylate, penta (meth) acrylate, hexa (meth) acrylate and the like ( And (meth) acrylate.

  Mono (meth) acrylates include acryloylmorpholine, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) ) Acrylate, dicyclopentenyloxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, 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) Recall-tetramethylene glycol) mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol mono (meth) acrylate, lauroxypolyethylene glycol mono (meth) acrylate, stearoxypolyethylene glycol mono ( And (meth) acrylate, nonylphenoxypolyethylene glycol mono (meth) acrylate, nonylphenoxypolypropylene glycol polyethylene glycol mono (meth) acrylate, and the like.

  Di (meth) acrylates include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 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) -Lutetramethylene glycol) di (meth) acrylate, methoxypolyethylene glycol di (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol di (meth) acrylate, lauroxypolyethylene glycol di (meth) acrylate, stearoxypolyethylene glycol di ( And (meth) acrylate, nonylphenoxypolyethylene glycol di (meth) acrylate, nonylphenoxypolypropylene glycol polyethylene glycol di (meth) acrylate, and the like.

  Examples of the tri (meth) acrylate include trimethylolpropane triacrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene oxide (6 Mole) modified trimethylolpropane triacrylate (BASF's Laromer (registered trademark) LR8863) and other alkylene oxide modified trimethylolpropane triacrylate (BASF manufactured by Laromer (registered trademark) PO33F).

  Examples of the tetra (meth) acrylate include pentaerythritol tetra (meth) acrylate, ethylene oxide (4 mol) modified pentaerythritol tetra (meth) acrylate (Daicel Cytec, Ebecryl 40), and other alkylene oxide modified pentaerythritol tetra (meth). An acrylate etc. are mentioned.

  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.

  Examples of the compound having a vinyl group other than the compound having a (meth) acryloyl group include styrene and N-vinyl-2-pyrrolidone.

  A radically polymerizable compound (B) may be used independently and may use multiple types together.

  As the radically polymerizable compound (B), poly (meth) acrylate is preferable because the hardness of the resulting coating film is further increased, and di (meth) acrylate, tri (meth) acrylate, tetra (meth) acrylate, penta ( More preferred are (meth) acrylates and hexa (meth) acrylates.

  Moreover, as a radically polymerizable compound (B), it is preferable to use the mixture of di (meth) acrylate and tri (meth) acrylate from the point which the hardness of a coating film increases more, and the adhesiveness to a plastic becomes high. . As the di (meth) acrylate, tripropylene glycol diacrylate and / or dipropylene glycol diacrylate is preferable from the viewpoint of availability. The tri (meth) acrylate is preferably trimethylolpropane triacrylate and / or trimethylolpropane trimethacrylate from the viewpoint of availability.

  In the polyurethane resin composition, the content of the radical polymerizable compound (B) is 5 to 80 parts by weight when the polyurethane resin (A), the radical polymerizable compound (B), and the total resin solid content are 100 parts by weight. Preferably, it is 20-60 weight part, More preferably, it is 30-50 weight part. When the addition amount of the radical polymerizable compound (B) is 5 parts by weight or more, the hardness of the coating film tends to be further increased, and when it is 80 parts by weight or less, the elongation and strength of the coating film tend to be increased. There is.

(Further ingredients)
The polyurethane resin composition can contain further components within a range not impairing the effects of the present invention. Examples of such components include an aqueous medium (C), a photopolymerization initiator, and other additives.

<Aqueous medium (C)>
The polyurethane resin composition can contain an aqueous medium (C). The polyurethane resin composition is preferable because it contains an aqueous medium (C) and thus the viscosity is lowered and the coatability is improved. In this case, the polyurethane resin (A) is preferably an aqueous polyurethane resin dispersion dispersed in the aqueous medium (C).

  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 N-ethyl. Examples include aprotic hydrophilic organic solvents such as pyrrolidone. The amount of the hydrophilic organic solvent in the aqueous medium is preferably 0 to 20% by weight.

<Photopolymerization initiator>
The polyurethane resin composition can contain a photopolymerization initiator.
As the photopolymerization initiator, those generally used can be used, for example, photocleavable type, hydrogen abstraction type, photocleavage type and hydrogen abstraction type that can be easily cleaved to form two radicals by ultraviolet irradiation. A mixture is mentioned. As photopolymerization initiators, 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-phenylpropane- - one, 2,4,6, - trimethyl benzophenone, 4-methylbenzophenone, 2,2-dimethoxy-1,2-diphenyl-ethanone, and the like, hydroxycyclohexyl phenyl ketone are preferred.

  In the polyurethane resin composition, the content of the photopolymerization initiator is preferably 0.5% by weight to 10% by weight and more preferably 1% by weight to 5% by weight with respect to the solid content of the polyurethane resin composition.

<Other additives>
If necessary, the polyurethane resin composition may contain other additives such as thickeners, photosensitizers, curing catalysts, UV absorbers, light stabilizers, antifoaming agents, plasticizers, surface conditioners, and antisettling agents. An agent can be included. An additive may be used individually by 1 type and may use 2 or more types together.

(Method for producing polyurethane resin composition)
The production method of the polyurethane resin composition includes at least a step (α) of obtaining a polyurethane resin (A) by reacting the polyester polyol (a) with the polyisocyanate (b), and the radical polymerization with the polyurethane resin (A). A step (γ) of mixing the compound (B).

  The step (α) is a step of obtaining the polyurethane prepolymer (A1) by reacting the polyester polyol (a), the acidic group-containing polyol compound (c), the other polyol (d), and the polyisocyanate (b). (Α1) or a step of obtaining a polyurethane prepolymer (A1) by reacting a polyester polyol (a), an acidic group-containing polyol compound (c), another polyol (d), and a polyisocyanate (b). (Α2) may also be used.

  In the step (α), the step (α1), and the step (α2), the polyurethane resin (A) includes a polyester polyol (a), a polyisocyanate (b), an optional acidic group-containing polyol (c), and others. The polyester polyol (a) and the polyisocyanate (b) may be obtained by a “one-shot method” in which at least one selected from the group consisting of the polyol (d) and the chain extender (D) is reacted at a time. And an optional acid group-containing polyol (c) and other polyol (d) are reacted to produce a polyurethane prepolymer (A1). The polyurethane prepolymer (A1) and the chain extender (D) May be obtained by a “prepolymer method” in which

  The step (α) for obtaining the polyurethane resin (A) and the steps (α1) and (α2) for obtaining the polyurethane prepolymer (A1) are preferably performed in an inert gas atmosphere. Examples of the inert gas include nitrogen and argon.

  When the step (α) is the step (α2), the method for producing a polyurethane resin composition may further include a step (β) for neutralizing the acidic group of the polyurethane resin (A1). As the neutralizing agent that can be used in the step (β), trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-phenyldiethanolamine, dimethylethanolamine, diethylethanolamine Organic amines such as N-methylmorpholine and pyridine; inorganic alkali salts such as sodium hydroxide and potassium hydroxide; ammonia and the like. As the neutralizing agent, organic amines are preferable, tertiary amines are more preferable, and triethylamine is particularly preferable. Here, the acidic group of the polyurethane prepolymer (A1) refers to a carboxylic acid group, a sulfonic acid group, or the like.

  The production method of the polyurethane resin composition may include a step (δ) of reacting the isocyanate group of the polyurethane prepolymer (A1) with the reactive chain extender (D).

  In the step (γ), the method of mixing the polyurethane prepolymer (A1) and the radical polymerizable compound (B) is not particularly limited.

  The step (γ) may include a step (γ1) of dispersing the polyurethane resin (A) and the radical polymerizable compound (B) in an aqueous medium. In the step (γ1), the method for dispersing the polyurethane prepolymer (A1) and the radical polymerizable compound (B) in the aqueous medium is not particularly limited. Therefore, as the step (γ), for example, a method in which the radically polymerizable compound (B) and the aqueous medium are mixed and dispersed in the polyurethane prepolymer (A1) at a time, and the polyurethane prepolymer (A1) is dispersed in the aqueous medium. A method of adding the radical polymerizable compound (B) after dispersion, a method of mixing the polyurethane prepolymer (A1) and the radical polymerizable compound (B) and then mixing with the aqueous medium, and a polyurethane pre-dispersed in the aqueous medium. There is a method of mixing the polymer (A1) with a radical polymerizable compound (B) dispersed in an aqueous medium. The radically polymerizable compound (B) can be added to the polyurethane prepolymer (A1) as a solution to which a solvent is added, if necessary.

  The step (γ) is preferably performed in the presence of oxygen in order to avoid unnecessary consumption of the double bond of the radical polymerizable compound (B). Moreover, you may add a polymerization inhibitor as needed.

  In the step (γ1), the method for dispersing the polyurethane prepolymer in the aqueous medium is not particularly limited, but the polyurethane prepolymer (A1) and the radically polymerizable substance are mixed in the aqueous medium stirred by a homomixer or a homogenizer. There are a method of adding the compound (B), a method of adding an aqueous medium to the polyurethane prepolymer (A1) and the radical polymerizable compound (B) which are stirred by a homomixer or a homogenizer.

  The step (γ) may be performed slowly under cooling, or in some cases, the reaction may be promoted under heating conditions of 60 ° C. or less. The reaction time under cooling is 0.5 to 24 hours, and the reaction time under heating conditions of 60 ° C. or less is 0.1 to 6 hours.

  In the method for producing a polyurethane resin composition, either the step (β) or the step (γ) may be performed first or at the same time. Further, the step (β), the step (γ), and the step (δ) may be performed simultaneously. The proportion of the polyurethane resin in the aqueous polyurethane resin dispersion is preferably 5 to 60% by weight, and more preferably 15 to 50% by weight.

(Coating composition)
The coating composition contains a polyurethane resin composition and a colorant. Examples of the colorant include one or more colorants selected from the group consisting of a color pigment, an extender pigment, and a bright pigment.

Examples of the coloring 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 can be used alone or in combination of two or more. 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 can be used alone or in combination of two or more. In particular, barium sulfate and / or talc are preferably used as extender pigments, and barium sulfate is more preferably used. As the bright pigment, 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 can be used.
The content of the colorant can be appropriately selected according to the desired degree of color development.

The coating composition can contain other resins other than the polyurethane resin (A). Examples of the other resins include one or more resins selected from the group consisting of polyester resins, acrylic resins, polyether resins, polycarbonate resins, epoxy resins, alkyd resins, and the like, and are selected from the group consisting of polyester resins and acrylic resins. One or more resins are preferred.

  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 oxide group.

  When the polyester resin and the acrylic resin have a hydroxyl group, a so-called urethane-modified polyester resin in which a part or all of the hydroxyl groups in the resin and a polyisocyanate compound are subjected to urethane reaction to extend these resins to increase the molecular weight. Or you may use together urethane-modified acrylic 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 the acid component, an aliphatic polybasic acid, an alicyclic polybasic acid, an aromatic polybasic acid, or the like can be used.

  The hydroxyl value of the polyester resin is preferably 10 to 300 mgKOH / g, more preferably 50 to 250 mgKOH / g, and still more preferably 80 to 180 mgKOH / g. The acid value of the polyester resin is preferably 1 to 200 mgKOH / g, more preferably 15 to 100 mgKOH / g, and further preferably 25 to 60 mgKOH / g. The weight average molecular weight of the polyester resin is preferably 500 to 50,000, more preferably 1,000 to 30,000, and further preferably 1,500 to 20,000.

  As the acrylic resin, a hydroxyl group-containing acrylic resin is preferable. Hydroxyl group-containing acrylic resin is produced by subjecting a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer to a solution polymerization method in an organic solvent, an emulsion in water It can be produced by copolymerization by a known method such as a polymerization method.

  The hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated bonds in one molecule. Hydroxyl group-containing polymerizable unsaturated monomers are (meth) acrylic such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. Monoesterified products of acids and dihydric alcohols having 2 to 8 carbon atoms; ε-caprolactone modified products of these monoesterified products; N-hydroxymethyl (meth) acrylamide; allyl alcohol; polyoxyethylene whose molecular terminal is a hydroxyl group Examples thereof include (meth) acrylate having a chain.

  The hydroxyl group-containing acrylic resin preferably has a cationic functional group. The hydroxyl group-containing acrylic resin having a cationic functional group can be produced, for example, by using a polymerizable unsaturated monomer having a cationic functional group such as a tertiary amino group or a quaternary ammonium base as the polymerizable unsaturated monomer.

  The hydroxyl value of the hydroxyl group-containing acrylic resin is preferably 1 to 200 mgKOH / g, more preferably 2 to 100 mgKOH / g, and even more preferably 3 to 60 mgKOH / g, from the viewpoints of storage stability and water resistance of the resulting coating film. . 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 1 to 200 mgKOH / g, and preferably 2 to 150 mgKOH / g, from the viewpoint of the water resistance of the resulting coating film. Is more preferable, and 5 to 100 mgKOH / g is 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 3,000 to 50,000.

  Examples of the polyether resin include polymers or copolymers having an ether bond. Specifically, polyoxyethylene-based polyether, polyoxypropylene-based polyether, polyoxybutylene-based polyether, bisphenol A or bisphenol. Examples thereof include polyethers derived from aromatic polyhydroxy compounds such as F.

  Examples of the polycarbonate resin include polymers produced from bisphenol compounds, and specific examples include bisphenol A / polycarbonate.

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

  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, polyhydric alcohols, fats and oils and fatty acids (soybean oil, linseed oil, coconut oil, stearic acid, etc.) Alkyd resin obtained by reacting a modifier such as

By including a curing agent in the coating composition, it is possible to improve the water resistance of the coating film or multilayer coating film using the coating composition.
As the curing agent, amino resins, polyisocyanate compounds, blocked polyisocyanate compounds, melamine resins, carbodiimides and the like can be used. Only one kind of curing agent may be used, or a plurality of kinds may be used in combination.

  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 compound include compounds having two or more isocyanate groups in one molecule, and specific examples include hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

  Examples of the blocked polyisocyanate compound include those obtained by adding a blocking agent to the polyisocyanate group of the aforementioned polyisocyanate compound. Examples of the blocking agent include phenols such as phenol and cresol, methanol, ethanol and the like. Examples include aliphatic alcohol-based blocking agents.

  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.

  In the coating composition, if necessary, ordinary additives for coating such as thickeners, curing catalysts, ultraviolet absorbers, light stabilizers, antifoaming agents, plasticizers, surface conditioners, anti-settling agents, etc. Or in combination of two or more.

  The manufacturing method of a coating composition can use a well-known manufacturing method. For example, the coating composition is prepared by mixing an aqueous polyurethane resin composition and a colorant, and optionally one or more components selected from the group consisting of a photopolymerization initiator, an additive, and other resins, and then an aqueous medium ( It can manufacture by adding C) and adjusting to the viscosity according to the coating method. Examples of the material to be coated of the coating composition include metals, plastics, inorganic materials, and wood. Examples of the coating method for the coating composition include bell coating, spray coating, roll coating, shower coating, and immersion coating.

(Coating composition)
The coating composition contains a polyurethane resin and does not contain a colorant. The components contained in the coating composition are as described above in the coating composition except for the colorant.

  Next, the present invention will be described in more detail with reference to examples and comparative examples.

[Synthesis Example 1]
UM90 (manufactured by UBE Corporation Europe, SA; number average molecular weight 907; hydroxyl value 124 mgKOH / g; 1,4-cyclohexanedimethanol and 1,6-hexanediol polyol) Polycarbonate diol obtained by reacting the mixture with carbonate ester (755 g), 1,6-hexanediol (202 g), 1,4-cyclohexanedimethanol (492 g), and maleic anhydride (417 g) Mixed at ° C. Thereafter, the temperature was raised to 190 ° C. under a nitrogen stream. During the reaction, water was removed from the reaction mixture by distillation. After 10 hours, the pressure was reduced to remove the remaining reaction water. As a result, a product (polyester polyol) having a hydroxyl value of 105 mgKOH / g and an acid value of 0.79 mgKOH / g was obtained.

[Synthesis Example 2]
In a reactor equipped with a stirrer and a heater, UH200N (manufactured by UBE Corporation Europe, SA; number average molecular weight 1,920; hydroxyl value 58.5 mgKOH / g; 1,6-hexanediol and carbonate ester are reacted. The polycarbonate diol thus obtained was mixed (477 g), 1,6-hexanediol (480 g), and maleic anhydride (301 g) at 150 ° C. Thereafter, the temperature was raised to 190 ° C. under a nitrogen stream. During the reaction, water was removed from the reaction mixture by distillation. After 10 hours, the pressure was reduced to remove the remaining reaction water. As a result, a product (polyester polyol) having a hydroxyl value of 118 mgKOH / g and an acid value of 0.29 mgKOH / g was obtained.

[Synthesis Example 3]
In a reactor equipped with a stirrer and a heater, 1,6-hexanediol (687 g) and maleic anhydride (472 g) were mixed at 150 ° C. Thereafter, the temperature was raised to 190 ° C. under a nitrogen stream. During the reaction, water was removed from the reaction mixture by distillation. After 10 hours, the pressure was reduced to remove the remaining reaction water. As a result, a product (polyester polyol) having a hydroxyl value of 99 mgKOH / g and an acid value of 0.55 mgKOH / g was obtained.

[Example 1]
In a reaction apparatus equipped with a stirrer and a heater, the polyester polyol (99.9 g) obtained in Synthesis Example 1, 2,2-dimethylolpropionic acid (13.4 g), and isophorone diisocyanate (77.9 g) were mixed. In N-ethylpyrrolidone (79.9 g), the mixture was heated at 80 to 90 ° C. for 3.5 hours in the presence of dibutyltin dilaurate (0.1 g) in a nitrogen atmosphere. The NCO group content at the end of the urethanization reaction was 4.38% by weight. The reaction mixture was cooled to 80 ° C., and triethylamine (10.1 g) was added and mixed thereto. After the reaction mixture (252 g) was cooled, a mixed solution of trimethylolpropane triacrylate (TMPTA) and tripropylene glycol diacrylate (TPGDA) (weight ratio 1: 1, 73.8 g) was mixed. And water (495 g). Subsequently, 35% by weight of 2-methyl-1,5-pentanediamine aqueous solution (37.2 g) was added to obtain an aqueous polyurethane resin dispersion.

[Example 2]
In a reaction apparatus equipped with a stirrer and a heater, the polyester polyol (71.7 g) obtained in Synthesis Example 2, 2,2-dimethylolpropionic acid (9.8 g), and isophorone diisocyanate (56.6 g) were mixed. , N-ethylpyrrolidone (55.5 g) in the presence of dibutyltin dilaurate (0.1 g) and heated at 80-90 ° C. for 3.5 hours in a nitrogen atmosphere. The NCO group content at the end of the urethanization reaction was 4.69% by weight. The reaction mixture was cooled to 80 ° C., and triethylamine (7.2 g) was added and mixed thereto. After cooling the reaction mixture (172 g), a mixed solution of trimethylolpropane triacrylate (TMPTA) and tripropylene glycol diacrylate (TPGDA) (weight ratio 1: 1, 51.9 g) was mixed. And water (342 g). Subsequently, 35% by weight of 2-methyl-1,5-pentanediamine aqueous solution (27.7 g) was added to obtain an aqueous polyurethane resin dispersion.

[Example 3]
In a reaction apparatus equipped with a stirrer and a heater, the polyester polyol (71.9 g) obtained in Synthesis Example 3, 2,2-dimethylolpropionic acid (9.8 g), and isophorone diisocyanate (57.2 g). , N-ethylpyrrolidone (55.2 g) in the presence of dibutyltin dilaurate (0.1 g) and heated at 80-90 ° C. for 3.5 hours in a nitrogen atmosphere. The NCO group content at the end of the urethanization reaction was 5.01% by weight. The reaction mixture was cooled to 80 ° C., and triethylamine (7.1 g) was added and mixed thereto. After cooling the reaction mixture (179 g), a mixed solution of trimethylolpropane triacrylate (TMPTA) and tripropylene glycol diacrylate (TPGDA) (weight ratio 1: 1, 54.7 g) was mixed. And water (381 g). Subsequently, 35% by weight of 2-methyl-1,5-pentanediamine aqueous solution (30.3 g) was added to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 1]
Polyester diol obtained by reacting ETERNACOLL UH100 (manufactured by Ube Industries; number average molecular weight 1,004; hydroxyl value 112 mgKOH / g; 1,6-hexanediol and carbonate) in a reaction apparatus equipped with a stirrer and a heater 60.1 g), 2,2-dimethylolpropionic acid (8.1 g) and isophorone diisocyanate (57.7 g) in dibutyltin dilaurate (0.1 g) in N-ethylpyrrolidone (53.5 g). ) In the presence of a nitrogen atmosphere at 80 ° C. for 4 hours. The NCO group content at the end of the urethanization reaction was 4.94% by weight. The reaction mixture was cooled to 80 ° C., and triethylamine (8.1 g) was added and mixed thereto. The reaction mixture (174 g) was mixed with a mixed solution of trimethylolpropane triacrylate (TMPTA) and tripropylene glycol diacrylate (TPGDA) (weight ratio of 1: 1, 51.8 g), and water (349 g) under strong stirring. ). Subsequently, 35% by weight of 2-methyl-1,5-pentanediamine aqueous solution (28.6 g) was added to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 2]
Obtained by reacting ETERRNACOLL (registered trademark) UH100 (manufactured by Ube Industries; number average molecular weight 1,004; hydroxyl value 112 mgKOH / g; 1,6-hexanediol and carbonate ester in a reaction apparatus equipped with a stirrer and a heater. Polycarbonate diol, 30.4 g), 2,2-dimethylolpropionic acid (DMPA, 8.6 g) and isophorone diisocyanate (IPDI, 50.9 g) in N-ethylpyrrolidone (43.2 g). In the presence of dibutyltin dilaurate (0.1 g), the mixture was heated at 80-90 ° C. for 2 hours in a nitrogen atmosphere. Furthermore, when a reaction product (1,6-HDL-EP-A, 12.5 g) of two molecules of acrylic acid and one molecule of 1,6-hexanediol diglycidyl was added and heated at 90 ° C., Gelation occurred and a polyurethane resin composition could not be obtained.

[Measurement of hydroxyl value and acid value]
The hydroxyl value and acid value of the polyester diol having an unsaturated bond obtained in Synthesis Examples 1 to 3 were measured based on JIS K 1557.

[Sample preparation for pencil hardness and adhesion]
3 wt% / solid content of a polymerization initiator (IRGACURE500, manufactured by Ciba Specialty Chemical Co., Ltd.) was added to each polyurethane resin composition of Examples 1 to 3 and Comparative Example 1 and stirred well to obtain a coating agent. This was uniformly coated on an acrylonitrile-butadiene-styrene (ABS) resin, an acrylic resin (PMMA), and a polycarbonate (PC) 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 of 1,000 mJ / cm ² ). The obtained polyurethane resin coating film was subjected to pencil hardness measurement and adhesion evaluation.

[Measurement of pencil hardness]
In the polyurethane resin coating film on the acrylic resin obtained in “Preparation of pencil hardness and adhesion sample”, the pencil hardness of the resin coating film was measured by a method according to JIS K 5600-5-4.

[Evaluation of adhesion]
The ABS resin, the acrylic resin, and the polyurethane resin coating on the PC resin obtained in “Pencil hardness and adhesion sample preparation” 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. When peeling of the coating film was not observed after peeling the cellophane tape, the test was repeated up to 10 times at the same location.
The results are summarized in Table 1.

  As for the pencil hardness in the table, for example, “H” indicates that the pencil of H is not damaged at all. “H-2H” indicates that the pencil of H is scratched or not scratched, and that 2H is not scratched at all. The adhesion in the table indicates the result of the peel test performed at three locations. “24/25” indicates that 24 cells are in close contact with each other in 25 cells after the test. The numbers in parentheses indicate the number of times the test was repeated at the same location.

  From the table, the polyurethane resin coating films of Examples 1 to 3 had a pencil hardness of HB or higher and were hard coating films. In Comparative Example 1, since the polyol did not have an unsaturated bond, the hardness was inferior. In Examples 1 and 2, since the polyester polyol contains a polycarbonate polyol, the adhesion between ABS and PC was excellent. In particular, Example 1 was excellent in the adhesion of ABS, PC, and PMMA because the polyester polyol contains both acyclic alkylene groups and cyclic alkylene groups.

Claims (10)

A polyurethane resin composition containing at least a polyurethane resin (A) and a radical polymerizable compound (B),
The polyurethane resin (A) has at least the formula (1):

[Wherein, R ¹ represents a divalent organic group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]
A polyester polyol (a) containing a repeating unit of:
A polyurethane resin composition comprising polyisocyanate (b) as a constituent component. The polyurethane resin composition according to claim 1, wherein R ¹ in Formula (1) is a C _{2 to} C ₂₀ alkylene group. In formula (1), —O—R ¹ —O— is at least one type of formula (2):

[Wherein R ² is a C _{2 to} C ₂₀ acyclic alkylene group. ]
The polyurethane resin composition of Claim 1 or 2 containing the unit of. In formula (1), —O—R ¹ —O— is at least one type of formula (3):

[Wherein R ³ is a C _{2 to} C ₂₀ cyclic alkylene group. ]
The polyurethane resin composition as described in any one of Claims 1-3 containing the unit of.   The polyurethane resin (A) comprises the polyester polyol (a) according to any one of claims 1 to 4, a polyisocyanate (b), and an acidic group-containing polyol (c) as constituent components. The polyurethane resin composition as described in any one of 1-4.   Furthermore, the polyurethane resin composition as described in any one of Claims 1-5 containing an aqueous medium (C).   Furthermore, the polyurethane resin composition as described in any one of Claims 1-6 containing a photoinitiator.   The coating composition containing the polyurethane resin composition and colorant as described in any one of Claims 1-7.   The coating composition which contains the polyurethane resin composition as described in any one of Claims 1-7, and does not contain a coloring agent. At least the formula (1):

[Wherein, R ¹ represents a divalent hydrocarbon group which may be interrupted with one or more selected from the group consisting of an ester bond, an ether bond and a carbonate bond. ]
A step (α) of obtaining a polyurethane resin (A) by reacting a polyester polyol (a) containing a repeating unit of the above and a polyisocyanate (d), and a polyurethane resin (A) and a radically polymerizable compound (B). The manufacturing method of the polyurethane resin composition of any one of Claims 1-6 including the process ((gamma)) to mix.