JP2011102335A - Method for producing urethane resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method by which even in the case of a high carboxy group content, molecular weight control is possible and urethane resin is stably obtained without causing gelling. <P>SOLUTION: The invention relates to the method for producing urethane resin (A) by reacting a high molecular weight diol (a), a diol (b) having a carboxy group and a diisocyanate (c), in which (a), (b) and (c) are subjected to urethanization reaction in a solvent (B) which has a boiling point of 30-80°C, dissolves the urethane resin (A) and is inert to isocyanates, and at the point of time when the NCO% of the urethane resin (A) becomes ≤3%, a solvent (C) is added in an amount of 1-5 wt.% based on the weight of the urethane resin (A). The solvent (C) is a polyalcohol or an aprotic polar solvent which has a solubility parameter of 11-20, dissolves the urethane resin (A) and is inert to isocyanates. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a carboxyl group-containing polyurethane resin.

Polyurethane resins containing carboxyl groups used for applications such as active energy ray-curable coatings, coatings for metal plates and plastic plates, are highly polar organic solvents inert to isocyanates [N, N-dimethylformamide ( In the following description, the reaction is performed by reacting the polyol component with the polyisocyanate component, and the urethane resin solution is poured into a large amount of water, the polyurethane resin is precipitated to remove the polar solvent, and another solvent. In general, it is produced by a method of substituting. However, this method has many troublesome operations such as treatment of a large amount of waste water containing an organic solvent, and uses an organic solvent having a high boiling point, and thus has problems in terms of environment and production.
There is known a method (Patent Document 1) in which, after urethanization in a low-boiling polar organic solvent inert to isocyanate, the low-boiling solvent is removed by distillation under reduced pressure, and the solvent is replaced with a high-boiling organic solvent.

JP-A-2002-131903

However, in the production method of Patent Document 1, gelation occurs due to pseudo-crosslinking by association of carboxylic acids when the carboxyl group content is high in a low boiling point polar solvent, and urethanization cannot be performed stably, and molecular weight and physical properties can be controlled. Therefore, it was difficult to manage urethanization in industrial production. Further, when the urethane resin has an active energy ray-polymerizable group, it is weak against heat, there is a risk of polymerization during vacuum distillation, and there is a problem that distillation at high temperature cannot be performed.
An object of the present invention is to provide a production method in which a molecular weight can be controlled even when the carboxyl group content is high, and a urethane resin can be obtained by stabilization without causing gelation.

The present invention
Polymeric diol (a),
Diol (b) having carboxyl group and diisocyanate (c)
In which a polyurethane resin (A) is produced,
(A), (b), and (c) have a boiling point of 30 to 80 ° C., dissolve the urethane resin (A), perform a urethanization reaction in a solvent (B) inert to isocyanate, and obtain a urethane resin. Production of polyurethane resin (A), wherein 1 to 5% by weight of solvent (C) is added to the weight of urethane resin (A) when NCO% of (A) becomes 3% or less Is the method.
Solvent (C): An aprotic polar solvent or polyalcohol having a solubility parameter of 11 to 20, which dissolves the urethane resin (A) and is inert to isocyanate.

According to the production method of the present invention, even when the carboxyl group content is high, the molecular weight can be controlled, and the urethane resin can be obtained by stabilization without causing gelation.

[Polymer diol (a)]
The high molecular diol (a) in the present invention includes a low molecular diol (a0) as necessary.

The polymer diol (a) is a diol having a hydroxyl group equivalent (hereinafter referred to as OH equivalent) of 250 or more, and can impart flexibility to the urethane resin (A).
Examples of (a) include polyether diol, polyester diol, polyether ester diol, polycarbonate diol, polymer polyol (diol), polyolefin diol, polyalkadiene diol, acrylic polyol (diol) and a mixture of two or more of these. .

  As the polyether diol, an alkylene oxide [hereinafter abbreviated as AO] of a compound having 2 active hydrogens (carbon number (hereinafter abbreviated as C) 2-18, for example, dihydric alcohol, dihydric phenol). And adducts and mixtures of two or more thereof.

Examples of the dihydric alcohol include ethylene glycol (hereinafter abbreviated as EG), propylene glycol (hereinafter abbreviated as PG), 1,3- and 1,4-butanediol (hereinafter abbreviated as BD), and 1,6-hexanediol (hereinafter abbreviated as PG). Abbreviated as HD), neopentyl glycol diethylene glycol (hereinafter abbreviated as NPG), diethylene glycol (hereinafter abbreviated as DEG), 3-methyl-1,5-pentanediol (hereinafter abbreviated as MPD); Examples include alcohols [described in JP-B No. 45-1474, such as 1,4-bis (hydroxymethyl) cyclohexane, m- and p-xylylene glycol].
Examples of the dihydric phenol include monocyclic polyhydric phenols (C6-18, such as pyrogallol, hydroquinone, phloroglucin), polycyclic polyhydric phenols (C12-30, such as dihydroxynaphthalene), bisphenol compounds (C12-30, such as bisphenol A,- S and -F). Of the compounds having two active hydrogens, dihydric alcohol is preferred from the viewpoint of flexibility of the urethane resin (A).

  Examples of the AO include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide (hereinafter abbreviated as BO), tetrahydrofuran (hereinafter abbreviated as THF), styrene oxide, and combinations of two or more thereof. (Block and / or random addition). Of these, PO, EO, BO, and combinations thereof are preferable from the viewpoint of the flexibility of (A).

Particularly preferred among those exemplified as the polyether diol are polyethylene glycol, polypropylene glycol and mixtures thereof.
The weight ratio when polyethylene glycol and polypropylene glycol are used in combination is usually 50/50 to 5/95, preferably 40/60 to 6/94.

  Examples of the polyester diol include (1) a condensed polyester diol obtained by condensation polymerization of one or more of the dihydric alcohol and one or more of a polycarboxylic acid or an ester-forming derivative thereof, and (2) the dihydric alcohol as an initiator. And polylactone diols obtained by ring-opening polymerization of lactones, and mixtures of two or more thereof.

  Examples of the polycarboxylic acid in the above (1) include aliphatic dicarboxylic acids (C4-18, such as succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, fumaric acid), aromatic ring-containing dicarboxylic acids (C8). To 24, such as terephthalic acid and isophthalic acid), ester-forming derivatives of these dicarboxylic acids (acid anhydrides, lower alkyl esters having an alkyl group of C 1-4), and combinations of two or more thereof. .

  Examples of the lactone in the above (2) include C4 to 12, for example, γ-butyrolactone, γ-valerolactone, ε-caprolactone, and combinations of two or more thereof.

  As the polyether ester diol, for example, one obtained by esterifying one or more of the polyether polyols and one or more of the polycarboxylic acids exemplified as the raw materials for the polyester polyols or ester-forming derivatives thereof, Examples thereof include those obtained by ring-opening addition of one or more lactones to one or more of the polyether polyols.

  Examples of the polycarbonate diol include polyhexamethylene carbonate diol, polytetramethylene carbonate diol, and combinations of two or more thereof.

  As the polymer diol, polymer particles obtained by polymerizing a vinyl monomer (C3-24, for example, styrene, acrylonitrile) in the presence of a radical polymerization initiator in one or more of the polymer diols listed above are dispersed and stabilized. Diol (polymer content is, for example, 5 to 30% by weight).

Examples of the polyolefin diol include polyisobutene diol.

  Examples of the polyalkadiene diol include polyisoprene diol, polybutadiene diol, hydrogenated polyisoprene diol, and hydrogenated polybutadiene diol.

  Examples of the acrylic diol include a copolymer of an alkyl (meth) acrylate (C1-30) ester [butyl (meth) acrylate and the like] and a hydroxyl group-containing acrylic monomer [hydroxyethyl (meth) acrylate and the like].

  Of these polymer diols (a), polyether diol, polyether ester diol, polyester diol and polycarbonate diol are preferable from the viewpoint of flexibility of the urethane resin (A).

The low molecular diol (a0) is a diol having an OH equivalent of less than 250.
Examples of (a0) include aliphatic low-molecular diols [C2-12, such as EG, DEG, triethylene glycol (hereinafter abbreviated as TEG), PG, BD, HD, NPG, MPD], low-molecular diols having a ring [special No. 45-1474, for example, 1,4-bis (hydroxymethyl) cyclohexane, m- and p-xylylene glycol], these AO low-mole adducts, and combinations of two or more thereof. Can be mentioned.

[Diol (b) having carboxyl group]
Examples of the diol (b) having a carboxyl group include α, α-dimethylolalkanoic acid (such as α, α-dimethylolpropionic acid, α, α-dimethylolbutanoic acid, α, α-dimethylolnonanoic acid), and tartaric acid. , Esterified product of 1 mol of citric acid and 1 mol of ethylene glycol (molecular weight; 240, acid value; 468, hydroxyl value; 468), esterified product of 1 mol of malic acid and 1 mol of ethylene glycol (molecular weight; 178, acid value) 315) hydroxyl value; 630) and salts thereof (sodium salt, potassium salt, ammonium salt, amine salt, etc.). Of these, α, α-dimethylolalkanoic acid is preferable, and α, α-dimethylolpropionic acid and α, α-dimethylolbutanoic acid are more preferable. Hereinafter, α, α-dimethylolalkanoic acid may be referred to as dimethylolalkanoic acid.

[Diisocyanate (c)]
The diisocyanate (c) in the present invention is a divalent aliphatic polyisocyanate [c2-12, such as ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate. Lysine diisocyanate, 2,6-diisocyanatomethylcaproate], alicyclic diisocyanate [c4-15, such as isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate], Aromatic aliphatic diisocyanates [2,4- and / or 2,6-tolylene diisocyanate (TDI), diethylbenzene diisocyanate 4,4'- and / or 2,4-diphenylmethane diisocyanate (MDI), naphthylene diisocyanate], modified products of these diisocyanates (urethane groups, carbodiimide groups, uretdione groups, isocyanurate groups, burette groups, etc. Modified products), and combinations of two or more of these.

  Of the above (c), aromatic diisocyanates are preferable from the viewpoint of reactivity, and MDI and TDI are more preferable. Further, from the viewpoint of weather resistance, preferred are aliphatic diisocyanates and alicyclic diisocyanates, and more preferred are HDI, IPDI and HMDI.

When the diol components (a) and (b) are reacted with the organic diisocyanate (c) to form the NCO group-containing polyurethane resin (A), the equivalent ratio of (a), (b) and (c) (NCO / OH ratio) is usually 0.90 to 1.3, preferably 0.98 to 1.15.

[Solvent (B)]
The urethanization reaction is performed in a solvent (B) having a boiling point of 30 to 80 ° C., which dissolves the urethane resin (A) and is inert to the isocyanate group.
If the boiling point of the solvent (B) is less than 30 ° C, there is a safety problem in performing the urethanization reaction, and if it exceeds 80 ° C, it is difficult to remove the solvent when the urethane resin (A) is used.
Examples of (B) include methylene chloride (boiling point 40 ° C), chloroform (boiling point 61 ° C), ethylidene chloride (boiling point 67 ° C), furan (boiling point 31 ° C), 2-methylfuran (boiling point 63 ° C), tetrahydrofuran (THF). ) (Boiling point 66 ° C), acetone (boiling point 57 ° C), ethyl formate (boiling point 54 ° C), methyl formate (boiling point 32 ° C), methyl acetate (boiling point 58 ° C), methyl ethyl ketone (MEK) (boiling point 78 ° C) and these Two or more types of mixed solvents are mentioned. Of these, MEK is particularly preferable.

[Solvent (C)]
The solvent (C) is an aprotic polar solvent or a polyalcohol (dihydric or higher alcohol) which has a solubility parameter of 11 to 20, dissolves the urethane resin (A), and is inert to isocyanate.
Specific examples include N, N-dimethylformamide, acetonitrile, dimethyl sulfoxide, N-methylpyrrolidone, polyalcohol and the like. Of these, N, N-dimethylformamide is preferred. No aprotic polar solvent is known which is inert to isocyanates with a solvent having a solubility parameter greater than 20. If the solubility parameter is less than 11, gelation occurs. Examples of the polyalcohol include dihydric alcohols (ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, etc.) and trihydric alcohols (glycerin, etc.).

Here, the solubility parameter is calculated by the Fedors method.
According to the Fedors method, the SP value can be expressed by the following equation.
SP value (δ) = (ΔH / V) ^1/2
In the formula, ΔH represents the heat of vaporization (cal), and V represents the molar volume (cm ³ ).
In addition, ΔH and V are the sum of the heat of molar evaporation (ΔH) of atomic groups described in “POLYMER ENGINEERING AND FEBRUARY, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. The total molar volume (V) can be used.
Those having a close numerical value are easy to mix with each other (high compatibility), and those having a close numerical value are indices that indicate that they are difficult to mix.

The urethanization reaction is preferably performed at 60 to 110 ° C, more preferably at 70 to 85 ° C.
The urethanization reaction is 1-5% by weight with respect to the weight of the urethane resin (A) when the NCO% is 3% or less in terms of the pure content of the urethane resin (A) in the reaction in the solvent (B). Add solvent (C). The molecular weight of the urethane resin (A) can be sufficiently increased by adding the solvent (C) and further performing the urethanization reaction. Further, thickening and gelation due to association of carboxyl groups can be prevented.
If the solvent (C) is added when the NCO% is higher than 3%, a long time is required for the urethanization reaction.
When the amount of the solvent (C) added is less than 1% by weight relative to the urethane resin (A), the above effect is not obtained, and when it exceeds 5% by weight, there is a problem in production when the urethane resin (A) is used.

Among the urethane resins (A), for example, active energy ray-curable urethane resins (A1) having one or more active energy ray polymerizable groups in the molecule are used for applications such as coatings and photoresists. The High molecular diol (a), diol (b) having a carboxyl group, diisocyanate (c) a functional group capable of reacting with an isocyanate group or hydroxyl group having one or more active energy ray polymerizable groups in the molecule Active energy ray-curable urethane resin having one or more active energy ray-polymerizable groups in the molecule by polymerizing the component (d) having one or two or more in the solvent (B) (A1) is manufactured.
As the component (d) having one or more active energy ray polymerizable groups in the molecule and one or more functional groups capable of reacting with an isocyanate group or a hydroxyl group in the molecule, d01) Component (d1) having an active energy ray-polymerizable cationic polymerizable group (for example, propenyl ether group, vinyl ether group and glycidyl group), (d02) radical polymerizable group (methacryloyl group, allyl group, propenyl in the molecule) And a component (d2) having a group and a vinyl group).

As the above (d1), C3 or more and Mn 3,000 or less, for example, those having a propenyl ether group [2-hydroxyethyl-, 2-hydroxypropyl-, 2,3-dihydroxypropylpropenyl ether, etc.], vinyl ether groups Having [2-hydroxyethyl-, 2-hydroxypropyl-, 2,3-dihydroxypropyl vinyl ether, etc.], having glycidyl group [glycidol, EG monoglycidyl ether, GR monoglycidyl ether, etc.], and their AO [ EO, PO, 1,2-, 1,3- and 2,3-BO, THF, styrene oxide and a combination of two or more thereof] adduct (Mn 3,000 or less).
Of these, those having a propenyl ether group or vinyl ether are preferred from the viewpoint of active energy ray curability, and more preferred are 2-hydroxyethyl propenyl ether, 2-hydroxyethyl vinyl ether, 2,3-dihydroxypropyl propenyl ether, 2 , 3-dihydroxypropyl vinyl ether and their EO and / or PO adducts.

As the above (d2), C3 or more and Mn5,000 or less, for example, those having a (meth) acryloyl group [C4-18, such as 2-hydroxyethyl-, 2-hydroxypropyl- and 2,3-dihydroxypropyl (meta ) Acrylate, C (excluding carbon in the NCO group, the same is true for the isocyanate compound) 3 to 13 monoisocyanate compounds such as 2- (meth) acryloyloxyethyl isocyanate, 1,1-bis [(meth) acryloyloxy Methyl] ethyl isocyanate etc.], those having an allyl group [C3-6, such as 2-hydroxyethyl-, 2-hydroxypropyl- and 2,3-dihydroxypropylallyl ether] and the like.
Among these, those having a (meth) acryloyl group are preferred from the viewpoint of active energy ray curability, and more preferred are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2,3-dihydroxy. Propyl (meth) acrylate, and their EO and / or PO adducts.

  The copolymer ratio of the component (d) is preferably 0 to 60%, more preferably 2 to 60% from the viewpoint of curability and mechanical strength of the cured product, based on the weight of the active energy ray-curable urethane resin (A1). 30%.

Examples of the reaction method of the urethane resin (A) include the following (1) and (2). When (A) is an active energy ray-curable urethane resin (A1), the description of [] shall be added.
(1) One-shot method In the presence of the solvent (B), the polymer diol (a), the diol (b) having a carboxyl group and the diisocyanate (c), [and one active energy ray polymerizable group in the molecule Or a component (d)] having two or more functional groups capable of reacting with an isocyanate group or a hydroxyl group in the molecule (d)], [(d)], (a), (b) and (c The NCO / OH equivalent ratio is preferably 0.9 to 1.3, more preferably 0.95 to 1.05, and polyaddition reaction is performed to obtain (A). For the purpose of controlling the molecular weight, the reaction was stopped by adding a D sealant described later [monoamine, monoalcohol, monool of (d) containing one or more active energy ray polymerizable groups, etc.]. It can also be made.

(2) Prepolymer method The following methods are mentioned.
(2-1) In the presence of the solvent (B), a diol having two hydroxyl groups of (a), (b) and [(d)] is reacted with diisocyanate (c) to give an NCO / OH equivalent The ratio is preferably 0.9 to 1.3, more preferably 0.95 to 1.05, and an isocyanate group-terminated urethane prepolymer, and the urethane prepolymer is added with a chain extender [the low molecular diol (a0), a diamine. Compound] and / or D sealing agent [monoamine, monoalcohol, [monool of (d) containing one or more active energy ray-polymerizable groups] described below] and the reaction ( A method to obtain A).
(2-2) In the presence of the solvent (B), (a), (b), [(d)] and (c) are reacted to give an NCO / OH equivalent ratio of preferably 0.9 to 1. 3, more preferably 0.95 to 1.05, an isocyanate group-terminated urethane prepolymer, and the urethane prepolymer as the same chain extender and polymerization terminator as (2-1) [active energy ray polymerizable group. A method of obtaining (A) by adding and reacting a monool (of (d) containing one or two or more).

  Examples of the diamine compound include aromatic ring-containing diamines [C6-24, such as phenylenediamine, toluenediamine, 4,4′-diaminodiphenylmethane, m- and p-xylylenediamine, diethyltoluenediamine, 2,4- and 2, 6-dimethylthiotoluenediamine], alicyclic diamine [C6-24, such as isophoronediamine, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 4,4 ′ -Diamino-3,3'-dimethyldicyclohexyl, diaminocyclohexane], aliphatic diamines [C1-18, eg ethylenediamine, 1,6-hexamethylenediamine], alkanolamine derivatives [C2-18, eg N- (2-amino Ethyl) ethanolamine , Hydrazine or a derivative thereof [C2～18, such as adipic acid dihydrazide, and mixtures of two or more thereof.

  Examples of the monoamine include alkyl (C1-8) amine (C1-12, such as ethylamine, butylamine, diethylamine, di-n-butylamine).

  Examples of the monoalcohol include alkyl alcohols having Mn of 300 or less, and AO adducts thereof (Mn of 300 or less), monohydric phenol AO adducts (Mn of 300 or less), and the like.

  Of the above methods, the one-shot method (1) is preferable from the viewpoint of easy molecular weight control.

When the polymer diol (a), the diol (b) having a carboxyl group, and the diisocyanate (c) are polymerized in the solvent (B), the components (a) to (c) are used from the viewpoint of the polymerization rate and the solution viscosity. Based on the total weight of the solvent (B), the total concentration of the components (a) to (c) is preferably 10 to 50% by weight. More preferably, it is 12 to 40 weight%, More preferably, it is 14 to 30 weight%, Especially preferably, it is 16 to 25 weight%, Most preferably, it is 18 to 23 weight%.
In addition, components (a) to (c), one or more active energy ray polymerizable groups in the molecule, and one or more functional groups capable of reacting with an isocyanate group or a hydroxyl group are contained in the molecule. When the component (d) is subjected to a polymerization reaction in the solvent (B), the component (a) is based on the total weight of the components (a) to (d) and the solvent (B) from the viewpoint of polymerization rate and solution viscosity. It is preferable that the total concentration of (d) is 10 to 50% by weight. More preferably, it is 12 to 40 weight%, More preferably, it is 14 to 30 weight%, Especially preferably, it is 16 to 25 weight%, Most preferably, it is 18 to 23 weight%.

In the urethanization reaction in the methods (1) to (2), a catalyst usually used for polyurethane can be used to accelerate the reaction. Examples of the catalyst include organometallic compounds [trimethyltin laurate, trimethyltin hydroxide, dimethyltin dilaurate, stannous octoate, red oleate, red 2-ethylhexoate dibutyltin dilaurate, dioctyltin laurate, bismuth carboxylate. , Bismuth alkoxide and a chelate compound of a compound having a dicarbonyl group and bismuth, etc.], inorganic metal compound [bismuth oxide, bismuth hydroxide, bismuth halide, etc.], amine [triethylamine, triethylenediamine, diazabicycloundecene, etc.] And combinations of two or more of these.
The usage-amount of a catalyst is 0.0001 to 0.1% normally based on the weight of (A), Preferably it is 0.001 to 0.01%.

In the methods (1) to (2), when the compound (d) having a radical polymerizable group as the active energy ray polymerizable group is used, a polymerization inhibitor (hydroquinone) is used for the purpose of improving the storage stability of (A1). 4-methoxyphenol, p-benzoquinone, etc.) can be used.
The amount of the polymerization inhibitor used is usually 3,000 ppm or less, preferably 10 to 2,000 ppm, based on the weight of (A1).

The carboxyl group content of the urethane resin (A) is preferably 2.0 to 10.0% by weight. Preferably, it is 4.0 to 8.0 weight%. When carboxyl group content is less than 2.0 weight%, a urethane resin (A) can be obtained with a normal manufacturing method.
A urethane resin (A) having a carboxyl group content exceeding 10.0% by weight is usually not practical.

The Mn of the urethane resin (A) in the present invention is preferably 2,500 to 100,000, more preferably 4,000 to 80,000, from the viewpoints of the cohesive strength and coating properties of the resin.
The weight average molecular weight (hereinafter abbreviated as Mw) of (A) is preferably from 2,800 to 200,000, more preferably from 3,500 to 140,000, from the viewpoint of the cohesive strength and coating properties of the resin.
The molecular weight distribution (indicated by Mw / Mn ratio) of (A) is preferably 8 or less, more preferably 4 or less, and particularly preferably 3 or less from the viewpoint of viscosity.
In addition, Mn per active energy ray polymerizable group (A) is preferably 400 to 20,000, more preferably 600 to 10,000, and particularly preferably from the viewpoint of flexibility and mechanical strength of the cured product. 800-5,000.

[Sealing agent (D)]
It is preferable to obtain a carboxyl group-containing urethane resin by sealing the NCO group (A) obtained by the above reaction with a sealing agent (D) comprising an aliphatic monohydric alcohol. As (D), an aliphatic monohydric alcohol having 1 to 4 carbon atoms (such as methyl alcohol, ethyl alcohol, n- and iso-propyl alcohol, n-, iso- and sec-butanol) is used. Of these, preferred are methyl alcohol and ethyl alcohol, and particularly preferred is methyl alcohol. The temperature of the sealing reaction is usually 30 to 150 ° C, preferably 50 to 100 ° C. The sealing reaction can be performed under normal pressure or under pressure. The amount of (D) used in the sealing reaction is usually 3 to 30 times equivalent per equivalent of NCO group in (A).

The urethane resin (A) obtained by the production method of the present invention is usually used as a solution of the urethane resin (A) and the solvent (B). A solvent other than (B) may be used as the solvent. The solution may contain a polymerization initiator (E), an additive (F) and the like, if necessary. Further, the urethane resin (A) can be used alone.
Examples of the additive (F) include an active energy ray-curable oligomer, an active energy ray sensitizer, a tackifier resin, a plasticizer, a filler, a pigment, an ultraviolet absorber, and an antioxidant.
The said mixture can be manufactured by mixing (A), (B), (E), (F) uniformly with a well-known mixing apparatus (A mixing tank equipped with a stirrer, a static mixer, etc.). Note that (E) and (F) are preferably mixed after the production of the resin solution (A) from the viewpoint of preventing side reactions, but a part or all of (E) and (F) is produced in advance for the production of (A). It may be added at any stage in the stage.
The temperature at which (A), (B) and, if necessary, (E), (F) are mixed is usually from 10 to 160 ° C., and preferably from 25 to 120 ° C. from the viewpoint of mixing properties and suppression of thermal deterioration.

As a coating apparatus for the urethane resin solution of the present invention, an ordinary applicator for resin coating [roll coater (gravure roll, reverse roll, etc.), spin coater, curtain coater, slot coater, bar coater, dispenser coating machines Etc.], extruders [single screw and twin screw extruders, kneader ruders, etc.] and the like.
The coating temperature of the resin solution when applied to the support is usually 10 to 160 ° C., preferably 25 to 120 ° C. from the viewpoint of coating properties and thermal deterioration suppression, and the viscosity at the coating temperature is usually 0. 01 to 10 Pa · s, preferably from 0.02 to 8 Pa · s, more preferably 0.03 from the viewpoints of moldability (can be thickly coated, free of warping after curing, no appearance defects such as sink marks) and coatability. ˜5 Pa · s.

  As a support to which the resin solution is applied, various plastics [polyolefin (polyethylene, polypropylene, etc.), polyurethane, polyethylene terephthalate, polyvinyl chloride, polyamide, etc.] films, sheets, foams, flat yarns and linear molded products, paper (Japanese paper, crepe paper, etc.), metal plate (aluminum, copper, etc.) or metal foil, metal wire, woven fabric, non-woven fabric, and wood.

The active energy ray-curable urethane resin solution (A1) of the present invention is applied to at least a part of the surface of these supports to form a coating film, and the coating film is irradiated with active energy rays and cured. Thus, a coating having a cured product (cured film) on at least a part of the support can be produced.
Moreover, the photoresist by photolithography which forms a pattern by selectively irradiating and hardening | curing an active energy ray to this coating film, and removes a non-irradiation part can be manufactured. The thickness of the cured product after active energy ray curing is usually 0.1 to 5,000 μm, preferably 0.5 to 500 μm, more preferably 1 to 500 μm from the viewpoint of mechanical strength and curability of the cured product (cured film). 100 μm.

  The active energy ray-curable urethane resin solution (A1) of the present invention can be poured into a mold for molding, then the solvent is removed, and the active energy ray is irradiated and cured to obtain a molded product.

The active energy rays in the curing of the active energy ray-curable urethane resin solution (A1) of the present invention include ultraviolet rays, electron beams, X-rays, infrared rays and visible rays. Of these active energy rays, ultraviolet rays, visible rays, and infrared rays are preferable from the viewpoints of curability and prevention of resin deterioration.
Among the active energy rays, the wavelength of ultraviolet rays, visible rays, infrared rays and the like is usually 200 to 800 nm, and preferably 200 to 450 nm from the viewpoint of the decomposition efficiency of the active energy ray polymerization initiator.

When the resin of the present invention is cured by ultraviolet irradiation, various light sources such as a mercury lamp (low pressure, high pressure, ultrahigh pressure, etc.), hydrogen lamp, deuterium lamp, halogen lamp, xenon lamp, carbon arc lamp, fluorescent lamp, He A -Cd laser or the like can be used, and a high-pressure mercury lamp is preferable. The irradiation amount of ultraviolet rays is usually from 0.01 to 1,000 mJ / cm @ 2, and preferably from 0.05 to 500 mJ / cm @ 2 from the viewpoint of the curability of the resin and the prevention of damage to the cured product and the support.

  When the composition of the present invention is cured by electron beam irradiation, various electron beam irradiation apparatuses [for example, Electron Beam, manufactured by Iwasaki Electric Co., Ltd.] can be used. The irradiation amount (Mrad) of the electron beam is preferably 0.5 to 20, and preferably 1 to 15 from the viewpoint of avoiding damage to the curability of the composition and the cured product and the support.

EXAMPLES Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto. In the following, parts indicate parts by weight, and% indicates% by weight.

Example 1
In a pressure vessel equipped with a pressure gauge, a stirrer and a thermometer, 79.6 parts of polypropylene glycol PP-2000 (a-1) [hydroxyl equivalent 1000 trade name Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd.] 32.0 parts of dimethylolpropionic acid (b-1) was charged and dehydrated under reduced pressure at 100 ° C. for 1 hour to reduce the water content to 0.1% or less. Subsequently, 69.7 parts of diphenylmethane diisocyanate, 806 parts of THF (B-1) (boiling point 66 ° C.), and 0.7 part of bismuth alkoxide (urethanization catalyst) [Neostan U-600 manufactured by Nitto Kasei Co., Ltd.] were charged. It is. Since the reaction was carried out at 80 ° C. for 20 hours and the NCO% was 3.0% in terms of pure polyurethane resin, 6 parts of dimethylformamide (C-1) (solubility parameter 12.1) was added. After a further 5 hours of reaction, 10 parts of methanol (D-1) was injected to stop the urethanization reaction. A polyurethane resin solution having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. was obtained. The polyurethane resin had a weight average molecular weight of 102,000 and a carboxyl group content of 5.9%.
The weight of dimethylformamide used was 3.3% by weight with respect to the pure weight of the obtained polyurethane resin.

Example 2
A pressure vessel equipped with a pressure gauge, a stirrer, and a thermometer was charged with 82.0 parts of polypropylene glycol PP-2000 (a-1) and 40.3 parts of dimethylolpropionic acid (b-1). Dehydration was carried out under reduced pressure for a time, and the water content was reduced to 0.1% or less. Subsequently, 11 parts of 2,3-dihydroxypropyl methacrylate (d-1) and 0.6 part of a polymerization inhibitor p-benzoquinone were charged, and then 101.7 parts of diphenylmethane diisocyanate (c-1), THF (B-1 ) 808.7 parts and 0.7 parts of bismuth alkoxide were charged. When the reaction was carried out at 80 ° C. for 20 hours and NCO% became 3.0% in terms of pure polyurethane resin, 8 parts of dimethylformamide (C-1) was added. After further reaction for 5 hours, 10 parts of methanol was injected to stop the urethanization reaction. A polyurethane resin solution having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. was obtained. The number average molecular weight of the polyurethane resin was 108,000, and the carboxyl group content was 5.8%.
The weight of dimethylformamide used was 3.4% by weight with respect to the pure weight of the obtained polyurethane resin.

Example 3
A pressure vessel equipped with a pressure gauge, a stirrer, and a thermometer was charged with 82.0 parts of polypropylene glycol PP-2000 (a-1) and 40.3 parts of dimethylolpropionic acid (b-1). Dehydration was carried out under reduced pressure for a time, and the water content was reduced to 0.1% or less. Subsequently, 11 parts of 2,3-dihydroxypropyl methacrylate (d-1) and 0.6 part of a polymerization inhibitor p-benzoquinone were charged, and then 101.7 parts of diphenylmethane diisocyanate (c-1), THF (B-1 ) 808.7 parts and the compound name bismuth alkoxide 0.7 parts. When the reaction was carried out at 80 ° C. for 20 hours and NCO% became 2.8% in terms of pure polyurethane resin, 8 parts of dimethylformamide (C-1) was added. After further reaction for 5 hours, 10 parts of methanol was injected to stop the urethanization reaction. An active energy ray-curable urethane resin solution having a methacryloyl group having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. in the molecule was obtained.
Subsequently, about 450 parts of THF was recovered from the urethane resin solution by vacuum topping (pressure: 20-80 kPa, temperature: 40 ° C.). To this was added 924 parts of propylene glycol monomethyl ether, followed by topping under reduced pressure, and it was confirmed that the THF peak disappeared by gas chromatography. Finally, the solid content was 20% and the viscosity was 450 mPa · s / 25 ° C. A propylene glycol monomethyl ether solution of polyurethane resin was obtained. The yield of polyurethane resin was 99%. The polyurethane resin had a weight average molecular weight of 108,000 and a carboxyl group content of 5.8%. The weight of dimethylformamide used was 3.4% by weight with respect to the pure weight of the obtained polyurethane resin.

Example 4
A pressure vessel equipped with a pressure gauge, a stirrer, and a thermometer was charged with 82.0 parts of polypropylene glycol PP-2000 (a-1) and 40.3 parts of dimethylolpropionic acid (b-1). Dehydration was carried out under reduced pressure for a time, and the water content was reduced to 0.1% or less. Subsequently, 11 parts of 2,3-dihydroxypropyl methacrylate (d-1) and 0.6 part of a polymerization inhibitor p-benzoquinone were charged, and then 101.7 parts of diphenylmethane diisocyanate (c-1), THF (B-1 ) 808.7 parts and the compound name bismuth alkoxide 0.7 parts. After reacting at 80 ° C. for 20 hours, 8 parts of dimethylformamide (C-1) was added when NCO% became 2.9% in terms of pure polyurethane resin. The reaction was further continued for 5 hours to obtain a polyurethane resin solution having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. The polyurethane resin had a weight average molecular weight of 108,000 and a carboxyl group content of 5.8%.
The weight of dimethylformamide used was 3.4% by weight with respect to the pure weight of the obtained polyurethane resin.

Comparative Example 1
In a pressure vessel equipped with a pressure gauge, a stirrer and a thermometer, 79.6 parts of polypropylene glycol PP-2000 (a-1) [hydroxyl equivalent 1000 trade name Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd.] 32.0 parts of dimethylolpropionic acid (b-1) was charged and dehydrated under reduced pressure at 100 ° C. for 1 hour to reduce the water content to 0.1% or less. Subsequently, 69.7 parts of diphenylmethane diisocyanate (c-1), 806 parts of THF (B-1) (boiling point 66 ° C.) and compound name bismuth alkoxide (urethanization catalyst) [Neostan U-600 manufactured by Nitto Kasei Co., Ltd.] 0.7 parts were charged. By reacting at 80 ° C. for 20 hours, NCO% was 3.0% in terms of pure polyurethane resin. Further, the reaction was continued for 5 hours as it was, but NCO% did not decrease any more and the viscosity increased rapidly. Therefore, 10 parts of methanol was injected and the urethanization reaction was stopped. A polyurethane resin solution having a solid content of 22.5% and a viscosity of 50 mPa · s / 25 ° C. was obtained. The polyurethane resin had a weight average molecular weight of 83,000 and a carboxyl group content of 5.9%.

Comparative Example 2
In the same reaction vessel as in Comparative Example 1, polypropylene glycol PP-2000 (a-1) [hydroxyl equivalent: 1000, trade name Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd.] 82.0 parts, dimethylolpropionic acid ( b-1) 40.3 parts was charged and dehydrated under reduced pressure at 100 ° C. for 1 hour to reduce the water content to 0.1% or less. Subsequently, 11 parts of 2,3-dihydroxypropyl methacrylate (d-1) and 0.6 part of a polymerization inhibitor p-benzoquinone were charged, and then 101.7 parts of diphenylmethane diisocyanate (c-1), THF (B-1 ) (Boiling point 66 ° C.) 808.7 parts and compound name bismuth alkoxide (urethanization catalyst) [Neostan U-600 manufactured by Nitto Kasei Co., Ltd.] 0.7 parts. The reaction was carried out at 80 ° C. for 20 hours, and NCO% was 2.9% in terms of pure polyurethane resin. Further, the reaction was continued for 5 hours as it was, but NCO% did not decrease and the viscosity increased rapidly. Therefore, 10 parts of methanol was injected to stop the urethanization reaction. A polyurethane resin solution having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. was obtained. The polyurethane resin had a weight average molecular weight of 74,000 and a carboxyl group content of 5.8%.

Comparative Example 3
In the same reaction vessel as in Comparative Example 1, polypropylene glycol PP-2000 (a-1) [hydroxyl equivalent: 1000, trade name Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd.] 82.0 parts, dimethylolpropionic acid ( b-1) 40.3 parts was charged and dehydrated under reduced pressure at 100 ° C. for 1 hour to reduce the water content to 0.1% or less. Subsequently, after 11 parts of 2,3-dihydroxypropyl methacrylate (d-1) and 0.6 part of a polymerization inhibitor p-benzoquinone were charged, 101.7 parts of diphenylmethane diisocyanate (c-1), N, N-dimethyl 808.7 parts of formamide and 0.7 parts of the compound name bismuth alkoxide (urethanization catalyst) [Neostan U-600 manufactured by Nitto Kasei Co., Ltd.] were charged. After reacting at 80 ° C. for 20 hours, when NCO% became 3.0% in terms of pure polyurethane resin, 10 parts of methanol was injected to stop the urethanization reaction. A polyurethane resin solution having a solid content of 22.5% and a viscosity of 100 mPa · s / 25 ° C. was obtained. Next, this resin solution was dropped into 12,000 parts of ion-exchanged water over about 5 hours to obtain a white precipitate. The precipitate was filtered and then dried for 24 hours with a normal air dryer (temperature; 40 ° C.). The yield of the polyurethane resin after drying was 85%. The dried polyurethane resin was redissolved in propylene glycol monomethyl ether so as to have a solid content of 20% to obtain a propylene glycol monomethyl ether solution of a polyurethane resin having a viscosity of 490 mPa · s / 25 ° C. The number average molecular weight of the obtained polyurethane resin was 19,000, and the content of carboxyl groups was 6.1%.

  As is clear from the results of the examples, the urethane resin solution produced by the production method of the present invention can be stabilized and urethanized compared to the comparative resin solution, so that the molecular weight can be sufficiently increased. Compared with the comparative example, the time required for the urethanization reaction and the subsequent treatment is short, the productivity is excellent, and the industrial production is possible under conditions friendly to the environment and hygiene.

The polyurethane resin obtained by the method for producing the urethane resin (A) of the present invention includes a coating agent for a metal plate or a plastic plate, a coating agent for various conductors such as an optical fiber and an electric wire, an insulator for protecting a connection part and a conductor connection part, It can be used in a wide range of applications as pattern formation of resin plates using photolithography, photoresist agents for electronic circuits, semiconductor sealants, and adhesives for various substrates.

Claims (6)

Polymeric diol (a),
Diol (b) having carboxyl group and diisocyanate (c)
In which a urethane resin (A) is produced by reacting
(A), (b), and (c) have a boiling point of 30 to 80 ° C., dissolve the urethane resin (A), perform a urethanization reaction in a solvent (B) inert to isocyanate, and obtain a urethane resin. Production of urethane resin (A), wherein 1 to 5% by weight of solvent (C) is added to the weight of urethane resin (A) when NCO% of (A) becomes 3% or less Method.
Solvent (C): An aprotic polar solvent or polyalcohol having a solubility parameter of 11 to 20, which dissolves the polyurethane resin (A) and is inert to isocyanate. Urethane resin (A) is a polymer diol (a),
Diol (b) having a carboxyl group,
Component (d) having one or more diisocyanates (c) and active energy ray polymerizable groups in the molecule and one or more functional groups in the molecule capable of reacting with isocyanate groups or hydroxyl groups
The process according to claim 1, wherein (a), (b), (c) and (d) are subjected to a urethanization reaction in the solvent (B). The production method according to claim 1 or 2, wherein the urethane resin (A) has a carboxyl group content of 2.0 to 10.0% by weight. The production method according to any one of claims 1 to 3, wherein the solvent (B) is methyl ethyl ketone or tetrahydrofuran. The production method according to any one of claims 1 to 4, wherein the solvent (C) is at least one selected from the group consisting of N, N-dimethylformamide, acetonitrile, dimethyl sulfoxide, and N-methylpyrrolidone. . A urethane cured resin film is obtained by irradiating an active energy ray to a coating film obtained by applying the active energy ray curable urethane resin solution obtained by the production method according to any one of claims 2 to 5. A method for producing a urethane cured resin film.