JP2007070472A - Epoxy polyol resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy polyol resin composition curable at a low temperature and capable of reducing the content of volatile organic chemicals (VOC) in a varnish or coating composition without degrading the workability and the corrosion resistance and mechanical properties of the obtained cured coating film. <P>SOLUTION: The epoxy polyol resin composition contains (A) an epoxy polyol resin produced by modifying (a1) an epoxy resin having a number-average molecular weight of 200-800 with (a3) a univalent alkylphenol and/or (a4) an alkanolamine, (B) an epoxy polyol resin produced by modifying (a2) an epoxy resin having a number-average molecular weight of 900-8,000 with (a3) a univalent alkylphenol and/or (a4) an alkanolamine, and (C) a polyhydroxy compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is capable of low-temperature curing that can reduce the content of volatile organic chemicals (VOC) in varnishes and coating compositions without impairing workability and corrosion resistance and mechanical performance of the resulting cured coating film. The present invention relates to a novel epoxy polyol resin composition.

  Conventionally, the resin composition containing an epoxy polyol resin obtained by reacting an epoxy resin with an active hydrogen-containing compound such as phenols, carboxylic acid, and amine is used to obtain the mechanical performance, corrosion resistance, and adhesion of the resulting cured coating film. It is widely used for flooring materials, paints, adhesives, lining agents, etc., regardless of whether it is outdoors or indoors.

  In particular, as an epoxy polyol resin composition that can be cured at low temperature and has good corrosion resistance of a cured product, a bifunctional epoxy resin is polyfunctionalized with a phenol novolac resin or the like, and then a monovalent alkylphenol and / or alkanolamine is reacted. The composition using the epoxy polyol resin obtained by making it react is proposed (for example, refer patent document 1).

  However, the amount of the volatile organic chemical (VOC) contained in the epoxy polyol resin composition proposed in the examples of Patent Document 1 is 30 to 40% by weight, which is a recent viewpoint of environmental protection. However, simply by reducing the VOC content and performing highly non-volatile differentiation, the viscosity becomes high, the handleability at the time of coating becomes worse, and gradually after adding a curing agent. Since the viscosity increases, there is a problem that the working time until the completion of coating is restricted, and a solution is required.

JP 2004-352866 A (page 3-4)

  In view of the above circumstances, the object of the present invention is to reduce the content of volatile organic chemicals (VOC) in varnishes and coating compositions without impairing workability and corrosion resistance and mechanical performance of the resulting cured coating film. An object of the present invention is to provide a low-temperature curable epoxy polyol resin composition that can be cured.

  As a result of intensive studies to solve the above problems, the present inventor has obtained an epoxy polyol resin obtained by modifying an epoxy resin in a specific number average molecular weight range with monovalent alkylphenols and / or alkanolamines. The resin composition used in combination of two kinds and containing a polyhydroxy compound does not impair the excellent performance of the conventional epoxy polyol resin composition, and the volatile organic chemical substance in the varnish or coating composition ( The inventors have found that the content of VOC) can be reduced and completed the present invention.

  That is, the present invention relates to an epoxy polyol resin (A) obtained by modifying an epoxy resin (a1) having a number average molecular weight of 200 to 800 with monovalent alkylphenols (a3) and / or alkanolamines (a4), and a number average molecular weight. An epoxy polyol resin (B) obtained by modifying 900 to 8000 epoxy resin (a2) with monovalent alkylphenols (a3) and / or alkanolamines (a4), and a polyhydroxy compound (C). An epoxy polyol resin composition is provided.

Hereinafter, the present invention will be described in detail.
The epoxy polyol resin (A) used in the present invention is composed of an epoxy resin having a number average molecular weight of 200 to 800 g / eq (hereinafter abbreviated as a low molecular weight epoxy resin) (a1) and a monovalent alkylphenol (a3) and / or alkanol. The epoxy polyol resin (B) is obtained by modifying with an amine (a4). The epoxy polyol resin (B) is a monovalent epoxy resin having a number average molecular weight of 900 to 8000 (hereinafter abbreviated as high molecular weight epoxy resin) (a2). It is obtained by modifying with alkylphenols (a3) and / or alkanolamines (a4). Here, the number average molecular weight of the low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) is GPC (gel permeation chromatography), and 0.1 g of a sample is dissolved in 10 ml of THF (tetrahydrofuran). This is a conversion value obtained by injecting 50 μl of this sample solution into a column and measuring polystyrene having a known molecular weight as a standard substance.

  The first feature of the present invention resides in that epoxy resins having different number average molecular weights are used in combination as an epoxy resin that is a raw material of the epoxy polyol resin. By using a plurality of epoxy resins in this manner, the so-called “kamaboko type” in the GPC chart, which has a wide molecular weight distribution and does not cause a large difference in the abundance ratio of compounds having different molecular weights in the entire resin. An epoxy polyol resin having a molecular weight distribution of can be obtained. By having such a “kamaboko-type” molecular weight distribution, it is possible to develop the flexibility of a cured product that is insufficient when using an epoxy polyol resin having only a low molecular weight, and an epoxy polyol resin having only a high molecular weight. When used, it becomes possible to reduce the content of the organic solvent in the varnish. Furthermore, since the molecular weight distribution is wide even if the curing reaction proceeds, the increase in the viscosity of the entire composition becomes gradual, and the working time can be secured. From the above point and the point of lack of flexibility of the resulting cured coating film, it is not preferable that the number average molecular weight of the low molecular weight epoxy resin (a1) is less than 200, and when the molecular weight exceeds 800, It is not preferred because it is difficult to form a “kamaboko-type” molecular weight distribution. Furthermore, when the number average molecular weight of the high molecular weight epoxy resin (a2) is less than 900, it is not preferable because it is difficult to form a “kamaboko” molecular weight distribution. When the molecular weight exceeds 8,000, the corrosion resistance and basicity of the cured coating film are not preferable. Adhesiveness with the material is insufficient, which is not preferable.

  The low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) are limited only in their molecular weights, and are not particularly limited in structure. Even if they have the same structure, they are different. It may be a thing. Examples of the structure include divalent phenols such as resorcin, hydroquinone, and catechol which may have a substituent, bisphenols such as bisphenol A, bisphenol F, bisphenol AD, and tetrabromobisphenol A, and epichlorohydrin and epibromohydrin. An epoxy resin obtained by reacting an epihalohydrin such as the above, an epoxy resin obtained by reacting a polyaddition product of the bisphenols with ethylene oxide, propylene oxide or the like and the epihalohydrin, neopentyl glycol, 1,6-hexane Examples thereof include epoxy resins obtained by reacting dihydric alcohols such as diol, 1,4-butanediol, polyethylene glycol, and polypropylene glycol with the epihalohydrin. It can also be used as a mixture of more species. In addition, some of the epoxy groups contained in these epoxy resins may be converted into the dihydric phenols, the bisphenols, the biphenols, the dihydroxynaphthalenes, the alkyl-substituted phenols and formalin condensates, the isophthalates. It may be a modified epoxy resin obtained by reacting with a primary amine such as dicarboxylic acids such as acid, terephthalic acid, adipic acid, sebacic acid and dimer acid, oleylamine, 2-ethylhexylamine and monoethanolamine.

  Among these, a bisphenol type epoxy resin is preferable and a bisphenol A type epoxy resin and / or a bisphenol F type epoxy resin is preferable from the viewpoint of excellent corrosion resistance of a paint using the obtained epoxy polyol resin composition. Particularly preferred.

  Moreover, from the point that the effect of the present invention is remarkably excellent, the weight ratio (a1) / (a2) of the low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) is 95/5 to 40/60. It is preferable that the ratio is 85/15 to 50/50.

  When the bisphenol type epoxy resin is used as the low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) of the present invention, the workability of the resulting epoxy polyol resin composition and the corrosion resistance of the cured coating film are excellent. From the above, the dispersity Mw / Mn of the low molecular weight epoxy resin (a1) is in the range of 1.0 to 2.0, and the dispersity Mw / Mn of the high molecular weight epoxy resin (a2) is 2.1 to 5.0. It is preferable that it is the range of these. Moreover, it is preferable that dispersion degree Mw / Mn of the mixture of a low molecular weight epoxy resin (a1) and a high molecular weight epoxy resin (a2) is the range of 2.5-30.0.

  Examples of the monovalent alkylphenols (a3) include phenol, cresol, pt-butylphenol, ps-butylphenol, p-octylphenol, nonylphenol, dodecylphenol and the like, and epoxy polyols obtained among them. Excellent flexibility of cured coatings using resin compositions and good compatibility with other inorganic and organic compounds used in combination for organic solvents and anticorrosive properties incorporated in paints In view of the above, alkylphenols having an alkyl group having 4 to 12 carbon atoms are preferably used, and nonylphenol is particularly preferably used.

  The alkanolamines (a4) are not particularly limited, but the curing rate of the resulting epoxy polyol resin composition is fast, and diethanolamine from the viewpoint of excellent adhesion to the substrate of the resulting cured coating film, It is preferable to use one or more compounds selected from the group consisting of diisopropanolamine and N-methylethanolamine.

  The monovalent alkylphenols (a3) and alkanolamines (a4) described above are used at the time of synthesizing the epoxy polyol resin (A) and the epoxy polyol resin (B). A thing may be used. Accordingly, the difference between the epoxy polyol resin (A) and the epoxy polyol resin (B) may be only the difference between the low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) used as a raw material. Is a rational method in which the low molecular weight epoxy resin (a1) and the high molecular weight epoxy resin (a2) are mixed in advance until uniform, and then the monovalent alkylphenols (a3) and / or alkanolamines (a4) are reacted. The manufacturing method can be used.

  Although the manufacturing method of an epoxy polyol resin is described below, since this manufacturing method is common about an epoxy polyol resin (A) and an epoxy polyol resin (B), and only the raw material to be used is different, a low molecular weight epoxy is used. The resin (a1) and the high molecular weight epoxy resin (a2) are collectively referred to as an epoxy resin.

  The reaction conditions of the epoxy resin with the alkylphenols (a3) and / or alkanolamines (a4) are not particularly limited, and one of the alkylphenols (a3) and the alkanolamines (a4) can be used alone. Alkylphenols (a3) and alkanolamines (a4) can be used, since the resulting epoxy polyol resin composition has a high curing rate at low temperatures and excellent adhesion to the substrate of the coating film. The epoxy resin and alkylphenols (a3) are reacted and the epoxy equivalent of the obtained resin is measured, and then the epoxy equivalent and the active hydrogen group of the alkanolamines (a4) are preferably used. The ratio (epoxy) / (active hydrogen) to the equivalent of 1.0 / 0.95 to 1.0 / 1.0 Charged ratio to form, and a method of reacting in the presence of an organic solvent which will be described later. By carrying out the sequential reaction in this way, gelation and rapid viscosity increase can be prevented, and industrial production becomes easy.

  The organic solvent that can be used here is not particularly limited as long as it can uniformly dissolve the epoxy resin, alkylphenols (a3), alkanolamines (a4), and the resulting epoxy polyol resin as raw materials. However, for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, esters such as ethyl acetate, butyl acetate, ethyl acetoacetate, 2-ethoxyethyl acetate, diethylene glycol dimethyl ether, propylene glycol monoethyl ether, ethylene glycol Ethers such as monoethyl ether acetate and propylene glycol monoethyl ether acetate, aromatic hydrocarbons such as xylene and toluene, N, N-dimethylformamide, N, N- Methylacetamide, terpenes, and the like. These solvents may be used as a mixed solvent of two or more in combination. Among these, it is excellent in solubility, and can be used as it is as an epoxy polyol resin composition of the present invention. From the viewpoint of good workability, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, Ethers, xylene, toluene, and mixed solvents thereof are preferably used.

  The polyhydroxy compound (C) used in the present invention is not particularly limited, and examples thereof include polyether polyols and polyester polyols. Examples of the polyether polyol include low molecular weight polyhydric alcohols, amines, polyhydric phenols, compounds having two or more active hydrogens such as water, and initiators such as ethylene oxide, propylene oxide, and butylene oxide. Examples thereof include products obtained by addition polymerization of a cyclic ether such as alkylene oxide or tetrahydrofuran. Examples of the low molecular weight polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neo Examples include pentyl glycol, 1,6-hexanediol, hydrogenated bisphenol A, glycerin, trimethylolpropane, and pentaerythritol. Examples of the amines include ammonium, ethylenediamine, hexamethylenediamine, ethanolamine, and propanolamine. Examples of the polyhydric phenols include resorcin, hydroquinone, bisphenol A, bisphenol F, and bisphenol S.

  Examples of the polyester polyol include condensates of the low molecular weight polyhydric alcohols or polyether polyols with polyvalent carboxylic acids, hydroxycarboxylic acids or carbonic acids, and ring-opening polymers of lactones. Examples of the polyvalent carboxylic acid include succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and the like. Examples of the hydroxycarboxylic acid include 12-hydroxystearic acid and castor oil fatty acid, and examples of the lactone include ε-caprolactam.

  Further, as the polyhydroxy compound (C), an adduct of hydroxycarboxylic acid and alkylene oxide, polybutadiene polyol, polyolefin polyol, polycarbonate diol, or the like can be used.

  Among these, when a polyether polyol is used, it is preferable because it is excellent in paint workability and water resistance of the coating film, and it is particularly preferable to use poly (oxyalkylene glycol) such as polyethylene glycol and polypropylene glycol. Most preferably, ether glycol is used.

  The molecular weight of the polyhydroxy compound (C) is not particularly limited, but is 200 to 6000, particularly 400 to 6000 as the weight average molecular weight from the viewpoint of excellent balance between paint workability and water resistance of the coating film. Those in the range of 3000 are preferably used.

  The weight ratio {(A) + (B)} / (C) of the total weight of the epoxy polyol resin (A) and the epoxy polyol resin (B) and the polyhydroxy compound (C) is particularly limited. However, the ratio is preferably 95/5 to 50/50, and particularly preferably 85/15 to 50/50 from the viewpoint of excellent balance between workability during coating (low viscosity) and water resistance of the cured coating film. More preferably, it is 60/40.

  The blending amount of the organic solvent in the epoxy polyol resin composition of the present invention is not particularly limited, but the aforementioned epoxy polyol resin (A), epoxy polyol resin (B), and polyhydroxy compound (C) are not limited. In combination, it is possible to adjust a low-viscosity varnish that is excellent in workability even if the amount of the organic solvent is small, and usually 100 parts by weight of the varnish (mixture of resins and organic solvent) Among them, 10 to 50 parts by weight of the organic solvent is blended, but a particularly highly soluble organic solvent (for example, a mixed solvent of ketones, acetates, ethers and aromatic organic solvents) is used. By adding 10 to 20 parts by weight, a low-viscosity varnish can be obtained.

  Moreover, as an epoxy polyol resin composition of this invention, in the range which does not impair the characteristic of this invention, epoxy polyol resin other than the above-mentioned epoxy polyol resin (A) and epoxy polyol resin (B) is used together as needed. The blending ratio at this time may be 5 to 30 parts by weight of the other epoxy polyol resin with respect to 100 parts by weight of {epoxy polyol resin (A) + epoxy polyol resin (B)} It is preferable because the resulting epoxy polyol resin composition is excellent in workability and anticorrosion.

  Furthermore, as the epoxy polyol resin composition of the present invention, a curing agent (D) can be used as necessary. In particular, when the resin composition is used for applications such as paints and adhesives, it is preferable to use a curing agent (D).

  The curing agent (D) is particularly limited as long as it is a compound that can react with a hydroxyl group in the epoxy polyol resin (A), the epoxy polyol resin (B), and the polyhydroxy compound (C) to form a cured coating film. For example, amino resins such as melamine resin, guanamine resin, and urea resin, isocyanate compounds, resol type phenol resins, and the like can be given.

  Among these, it is preferable to use an isocyanate compound because it can be cured at room temperature, and the compatibility with the epoxy polyol resin (A), the epoxy polyol resin (B), and the polyhydroxy compound (C) is excellent. Therefore, it is particularly preferable to use an isocyanate compound having an isocyanate equivalent of 100 to 500 g / eq.

  In addition, the number of functional groups (isocyanate groups) in one molecule of the isocyanate compound is not particularly limited, but is usually 2 to 6, and includes an epoxy polyol resin (A) and an epoxy polyol resin (B ) And the polyhydroxy compound (C) are preferably 2 to 4 from the viewpoint that the coating proceeds rapidly and a coating film having excellent adhesion and corrosion resistance is obtained.

  The isocyanate compound is not particularly limited. For example, the diisocyanate includes aromatic isocyanates such as phenylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate, and metaxylylene diisocyanate. Aliphatic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, dimer diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated metaxylylene diisocyanate, Cycloaliphatic diisocyanates such as norbornene diisocyanate Theft, etc., and the like.

  Examples of the polyisocyanate other than the diisocyanate include polymethylene polyphenyl isocyanate, dimethyltriphenylmethane tetraisocyanate, triphenylmethane triisocyanate, and tris (isocyanatophenyl) -triphosphate.

  Furthermore, as the isocyanate compound, it is also possible to use those subjected to various modification reactions for the purpose of reducing the vapor pressure, adjusting the viscosity, the number of functional groups, the reactivity, and imparting special physical properties using the above isocyanate. it can. Examples of these are urethane prepolymers that are reaction products with alcohols, allophanate-modified isocyanates obtained by addition reaction of isocyanate groups, biuret-modified isocyanates, uretdione-modified isocyanates, isocyanurate-modified isocyanates, Examples thereof include a carbodiimide-modified product, an uretonimine-modified product, an acylurea diisocyanate product, and the like utilizing an isocyanate group condensation reaction.

  Examples of the urethane prepolymers include diols composed of dimers of unsaturated alcohols such as ethylene glycol, polyethylene glycol, polypropylene glycol, and oleyl alcohol, trimethylolpropane, glycerin, 1,2,6-hexanetriol, Examples thereof include compounds having an isocyanate group at the terminal, obtained by reacting a polyol such as polyester polyol with the isocyanate compound.

  These isocyanate compounds may be used alone or as a mixture of two or more.

  The blending ratio of the epoxy polyol resin (A), the epoxy polyol resin (B) and the polyhydroxy compound (C) and the isocyanate compound is not particularly limited, but has excellent physical properties of the resulting cured coating film. From the equivalent ratio (hydroxyl group) / (isocyanate group) of the total of hydroxyl groups in {epoxy polyol resin (A), epoxy polyol (B), polyhydroxy compound (C)} and isocyanate groups in isocyanate compound (D) Is preferably 1.0 / 0.3 to 1.0 / 1.2, particularly preferably 1.0 / 0.5 to 1.0 / 1.0.

  When the epoxy polyol resin composition of the present invention is used for coating applications, various fillers such as rust preventive pigments, colored pigments, extender pigments, various additives, other synthetic resins, and the like are blended as necessary. Is preferred. Examples of the rust preventive pigment include zinc powder, aluminum phosphomolybdate, zinc phosphate, aluminum phosphate, barium chromate, aluminum chromate, and scaly pigments such as graphite. Color pigments include carbon black, oxidized Examples thereof include titanium, zinc sulfide, and bengara. Examples of extender pigments include barium sulfate, calcium carbonate, talc, and kaolin. As a compounding quantity of these fillers, 20-70 weight with respect to a total of 100 weight part of an epoxy polyol resin (A), an epoxy polyol resin (B), a polyhydroxy compound (C), an organic solvent, and a hardening | curing agent (D). It is preferable that it is a part from points, such as coating-film performance and coating workability | operativity.

  Examples of the additive include repellency inhibitors, anti-sagging agents, spreading agents, antifoaming agents, curing accelerators, ultraviolet absorbers, and light stabilizers.

  Examples of the synthetic resins include chlorinated rubber, coumarone resin, and petroleum resin.

  The method of blending the filler, additive, synthetic resin and the like into the epoxy polyol resin composition of the present invention is not particularly limited. For example, the filler, additive, synthetic resin, etc. are mixed with an apparatus such as a mixer, a ball mill or the like. Prepare a pigment paste sufficiently kneaded and uniformly dispersed in advance, and further knead and disperse this and the epoxy polyol resin composition using the above apparatus, add a curing agent, and add an organic solvent to a desired concentration The method of using and preparing and mixing uniformly is mentioned.

  The epoxy polyol resin composition prepared for the paint obtained by the above technique can be applied to various substrates by various coating methods, and the technique is not particularly limited. For example, a gravure coater And coating methods such as knife coater, roll coater, comma coater, spin coater, bar coater, brush coating, dipping coating and spray coating.

  Further, the curing method after coating the epoxy polyol resin composition prepared for the paint is not particularly limited, and a cured coating film can be obtained by any of room temperature curing and heat curing.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

Example 1
To a four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube, EPICLON 860 (bisphenol A type epoxy resin, number average molecular weight 480, dispersity Mw / Mn = 1.8, Dainippon Ink & Chemicals, Inc. 300 parts are charged, heated to 120 ° C. and melted, and then EPICLON 2050 (bisphenol A type epoxy resin, number average molecular weight 1300, dispersity Mw / Mn = 2.5, manufactured by Dainippon Ink & Chemicals, Inc.) ) 200 parts were charged and the mixture was stirred at the same temperature for 1 hour to make it uniform. The degree of dispersion of the two epoxy resin mixtures was Mw / Mn = 4.5. To this, 288 parts of nonylphenol and 0.1 part of a 50% aqueous solution of tetramethylammonium chloride as a catalyst were added and stirred at 140 ° C. for 5 hours. did. After cooling, 272 parts of methyl ethyl ketone, PTMG1000 (polytetramethylene ether glycol, hydroxyl value 113 mgKOH / g, weight average molecular weight 2,500, manufactured by Mitsubishi Chemical Co., Ltd.) An epoxy polyol resin composition having a hydroxyl value of 137 mgKOH / g and a viscosity of 1250 mPa · s (25 ° C.) was obtained. This is defined as (E-1).

Example 2
To a four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube, EPICLON 850-S (bisphenol A type epoxy resin, number average molecular weight 350, dispersity Mw / Mn = 1.2, Dainippon Ink & Chemicals, Inc. 300 parts, EPICLON 4050 (bisphenol A type epoxy resin, number average molecular weight 1900, dispersity Mw / Mn = 2.6, manufactured by Dainippon Ink & Chemicals, Inc.) 100 parts are charged and heated to 120 ° C. to melt Homogenized. The degree of dispersion of the two epoxy resin mixtures was Mw / Mn = 5.5. Thereafter, 325 parts of nonylphenol and 0.1 part of a 50% aqueous solution of tetramethylammonium chloride as a catalyst were charged and stirred at 140 ° C. for 5 hours. Next, 25.4 parts of diethanolamine was added and further stirred for 3 hours. After cooling, 300 parts of methyl ethyl ketone and 450 parts of PTMG1000 were sequentially charged and homogenized to obtain an epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 126 mgKOH / g, and a viscosity of 1800 mPa · s (25 ° C.). This is defined as (E-2).

Example 3
The same procedure as in Example 1 except that diethanolamine was changed to 34.9 parts of diisopropanolamine (Mitsui Chemicals Co., Ltd.), 274 parts of methyl ethyl ketone, and 274 parts of PTMG1000. Nonvolatile content 80%, hydroxyl value 136 mgKOH / g, An epoxy polyol resin composition having a viscosity of 1100 mPa · s (25 ° C.) was obtained. This is defined as (E-3).

Example 4
The same procedure as in Example 1 was carried out except that amino alcohol MMA (N-methylethanolamine, manufactured by Nippon Emulsifier Co., Ltd.) 19.7 parts, methyl ethyl ketone 269 parts, PTMG1000 269 parts was used instead of diethanolamine. An epoxy polyol resin composition having a hydroxyl value of 127 mgKOH / g and a viscosity of 950 mPa · s (25 ° C.) was obtained. This is defined as (E-4).

Example 5
In Example 1, the same procedure was followed except that EPICLON 860 300 parts, EPICLON 2050 300 parts, nonylphenol 284 parts, diethanolamine 46.4 parts, methyl ethyl ketone 310 parts, PTMG 1000 310 parts, 80% non-volatile content, hydroxyl value 150 mg KOH / g, An epoxy polyol resin composition having a viscosity of 2200 mPa · s (25 ° C.) was obtained. The degree of dispersion Mw / Mn when the two epoxy resins were mixed was 4.7. This is defined as (E-5).

Example 6
In Example 5, PTMG1000 was changed to PTMG650 (polytetramethylene ether glycol, hydroxyl value 169 mgKOH / g, weight average molecular weight 1,400, manufactured by Mitsubishi Chemical Corporation) 310 parts in a similar manner, with a nonvolatile content of 80%. An epoxy polyol resin composition having a hydroxyl value of 161 mgKOH / g and a viscosity of 1740 mPa · s (25 ° C.) was obtained. This is defined as (E-6).

Example 7
An epoxy polyol resin composition having a nonvolatile content of 80%, a hydroxyl value of 122 mgKOH / g, and a viscosity of 500 mPa · s (25 ° C.) was obtained in the same manner as in Example 1 except that methyl ethyl ketone was changed to 408 parts and PTMG1000 815 parts. This is defined as (E-7).

Example 8
To a four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube, EPICLON 830 (bisphenol F type epoxy resin, number average molecular weight 290, dispersity Mw / Mn = 1.1, Dainippon Ink & Chemicals, Inc. 300 parts, EPICLON FQ-041-P (bisphenol F type epoxy resin, number average molecular weight 1350, dispersity Mw / Mn = 3.3, manufactured by Dainippon Ink & Chemicals, Inc.) 100 parts are charged at 120 ° C. It was made uniform by stirring for 1 hour. The degree of dispersion of the two epoxy resin mixtures was Mw / Mn = 13.7. To this, 350 parts of nonylphenol and 0.1 part of a 50% aqueous solution of tetramethylammonium chloride as a catalyst were added and stirred at 140 ° C. for 5 hours. Then, 26.2 parts of diethanolamine was added and stirred for another 3 hours. After cooling, 310 parts of methyl ethyl ketone and 466 parts of PTMG650 were sequentially charged and homogenized to obtain an epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 147 mgKOH / g, and a viscosity of 1600 mPa · s (25 ° C.). This is defined as (E-8).

Example 9
In a four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube, 400 parts of EPICLON 850, EPICLON HM-091 (bisphenol A type epoxy resin, number average molecular weight 6,000, dispersity Mw / Mn = 4. 2, made by Dainippon Ink & Chemicals, Inc.) 100 parts were charged and uniformed by stirring at 160 ° C. for 2 hours. The degree of dispersion of the two epoxy resin mixtures was Mw / Mn = 25.4. To this, 411 parts of nonylphenol and 0.1 part of a 50% aqueous solution of tetramethylammonium chloride as a catalyst were added and stirred at 140 ° C. for 7 hours. Then, 31.7 parts of diethanolamine was added and stirred for 3 hours. After cooling, 515 parts of methyl ethyl ketone and 618 parts of PTMG650 were sequentially charged and homogenized to obtain an epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 107 mgKOH / g, and a viscosity of 1700 mPa · s (25 ° C.). This is defined as (E-9).

Comparative Example 1
A four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube was charged with 300 parts of EPICLON 850-S, 266 parts of nonylphenol and 0.1 part of a 50% aqueous solution of tetramethylammonium chloride as a catalyst. Stir for hours. Next, 39.6 parts of diethanolamine was added and further stirred for 3 hours. After cooling, 159 parts of methyl ethyl ketone and 32 parts of PTMG1000 were successively charged and homogenized to obtain an epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 170 mgKOH / g, and a viscosity of 2500 mPa · s (25 ° C.). This is defined as (E′-1).

Comparative Example 2
300 parts of EPICLON 850-S and 167 parts of bisphenol A were charged into a four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube, and the temperature was raised. At 80 ° C., 0.1 part of an 80% aqueous solution of tetrabutylphosphonium chloride was added and reacted at 200 ° C. for 5 hours to obtain an epoxy resin having a number average molecular weight of 8,000. After adding 8 parts of nonylphenol to this and reacting for 5 hours, 9.6 parts of diethanolamine was added and reacted for another 3 hours. An epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 141 mgKOH / g, and a viscosity of 2000 mPa · s (25 ° C.) is obtained by adding 1938 parts of PTMG650 while cooling and homogenizing and then adding 606 parts of methyl ethyl ketone and homogenizing with stirring. Got. This is defined as (E′-2).

Comparative Example 3
A four-necked flask equipped with a thermometer, a stirrer, and a nitrogen gas inlet tube was charged with 300 parts of EPICLON 850-S, 70 parts of bisphenol A, and 9 parts of phenol novolac resin (average number of nuclei 4.7). did. At 80 ° C., 0.1 part of an 80% aqueous solution of tetrabutylphosphonium chloride was added and reacted at 140 ° C. for 3 hours to obtain an epoxy resin having a number average molecular weight of 920. After adding 120 parts of nonylphenol here and making it react for 5 hours, 33 parts of diethanolamine was added and it was made to react for 3 hours. While cooling, 134 parts of methyl ethyl ketone was added and the mixture was stirred and homogenized to obtain an epoxy polyol resin composition having a non-volatile content of 80%, a hydroxyl value of 186 mgKOH / g, and a viscosity of 70,000 mPa · s (25 ° C.). This is defined as (E′-3).

The number average molecular weight of the epoxy resin was measured using GPC under the following conditions. A sample solution was prepared by dissolving 0.1 g of a sample in 10 ml of THF, 50 μl of this sample solution was injected into a column, and the retention time was measured under the following conditions. The number average molecular weight is a converted value using polystyrene having a known molecular weight as a standard substance.
Equipment: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSG-GUARDCOLUMN + TSG-GEL G2000HXL × 2 + TSG-GEL G3000HXL + TSG-GEL G4000HXL (all manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Mobile phase, flow rate: THF (1 ml / min)
Peak detection method: RI

Examples 10-18 and Comparative Examples 4-6
Epoxy polyol resin compositions (E-1) to (E-9) and (E′-1) to (E′-3) which are the varnishes obtained in Examples 1 to 9 and Comparative Examples 1 to 3. Using Examples 10 to 18 and Comparative Examples 4 to 6 which are resin compositions for paints were obtained by kneading the filler and the curing agent in the blending amounts shown in Table 1. As the curing agent, Vernock D-750 (trimethylolpropane adduct of tolylene diisocyanate, non-volatile content 75% ethyl acetate solution, isocyanate content 13%, manufactured by Dainippon Ink & Chemicals, Inc.) was used as a thinner. A solvent (ethylene glycol monoethyl ether acetate / methyl isobutyl ketone / xylene = 1/4 weight ratio) was used. The resin composition for paint described in Table 1 has a non-volatile content of 80% and a dry PWC = 50%. In addition, the resin composition for coating materials of Comparative Example 6 was in the form of a paste.

  Using the obtained epoxy polyol resin composition for paints, the workability and the performance of the cured coating film were tested by the following test methods, and the results are shown in the lower part of Table 1.

Each evaluation test was performed according to the following method.
Workability 90 g of the resin composition for paint was weighed into a 100 ml mayonnaise bottle, and the time until the viscosity increased 2 and 3 times was measured immediately after the preparation of the paint using a rotary viscometer in an atmosphere of 5 ° C.

Adhesion Cold-rolled steel sheet: JIS, G, 3141 (SPCC, SB), 0.8 × 70 × 150 mm sandpaper # 240 surface treatment plate with a bar coater to a dry film thickness of 40 μm (However, since Comparative Example 6 could not be coated with a bar coater, it was applied using an applicator.) And dried at 25 ° C. for 7 days to prepare a test piece. Using this test piece, a cross-cut test at 1 mm intervals was performed according to JIS K5400 6.15.
○: No peeling ×: Peeling

Flexibility As in the adhesion test, a coating composition was applied to a 0.3 × 50 × 100 mm polished steel plate and dried to obtain a test piece. Using this test piece, a bendability test using a 2 mmφ test bar was performed according to JIS K5600 5.1.
○: No peeling.
X: Peeling / cracking occurred.

Impact resistance Using a test piece obtained in the same manner as in the adhesion test, a DuPont impact test (load 500 g, striker 1/2 inch) was performed according to JIS K5400-7,8.
○: No abnormality in 50 cm.
X: It peels at 50 cm.

Corrosion resistance After a cross-cut was put into a test piece obtained in the same manner as in the adhesion test using a cutter, a salt spray test (250 hours) was conducted according to JIS K5400-7,8. In addition, a numerical value is the peeling width (mm) from a crosscut part.

The test piece obtained in the same manner as in the water resistance adhesion test was visually checked for the appearance of the coating film on the water phase surface after being immersed in deionized water at 40 ° C. for 7 and a half days.
○: No blister ×: Blister occurs

  From the result of Table 1, Examples 10-18 which are the epoxy polyol resin compositions of this invention have low organic solvent content of the varnish and the resin composition for coatings in any case, workability | operativity, cured coating film corrosion resistance, etc. Confirmed that it is excellent. On the other hand, Comparative Example 4 using an epoxy polyol resin obtained by using only an epoxy resin having a low number average molecular weight is inferior in workability and has a hard coating film although water resistance and corrosion resistance are equivalent, and an epoxy having a high number average molecular weight. In Comparative Example 5 using an epoxy polyol resin obtained by using a resin, it was confirmed that the workability and water resistance were poor. Moreover, in the comparative example 6 which highly differentiated the epoxy polyol resin composition of patent document 1, it confirmed that workability | operativity was inferior.

Claims (10)

Epoxy polyol resin (A) obtained by modifying epoxy resin (a1) having a number average molecular weight of 200 to 800 with monovalent alkylphenols (a3) and / or alkanolamines (a4), and epoxy resin having a number average molecular weight of 900 to 8000 An epoxy polyol resin comprising an epoxy polyol resin (B) obtained by modifying (a2) with a monovalent alkylphenol (a3) and / or an alkanolamine (a4), and a polyhydroxy compound (C) Composition. The weight ratio (a1) / (a2) of the epoxy resin (a1) and the epoxy resin (a2) is 95/5 to 40/60, and the epoxy polyol resin (A) and the epoxy polyol resin (B) The epoxy polyol resin composition according to claim 1, wherein a weight ratio {(A) + (B)} / (C) of the total weight of the polyhydroxy compound (C) is 95/5 to 50/50. The monovalent alkylphenol (a3) is an alkylphenol having an alkyl group having 4 to 12 carbon atoms, and the alkanolamines (a4) are one or more selected from the group consisting of diethanolamine, diisopropanolamine and N-methylethanolamine The epoxy polyol resin composition according to claim 1, which is a compound of: The epoxy polyol resin composition according to claim 1, wherein the polyhydroxy compound (C) is poly (oxyalkylene glycol). The epoxy polyol resin composition according to claim 4, wherein the poly (oxyalkylene glycol) is polytetramethylene ether glycol. The epoxy polyol resin composition according to claim 1, wherein the epoxy resin (a1) is a bisphenol type epoxy resin, and the epoxy resin (a2) is a bisphenol type epoxy resin. The dispersity Mw / Mn of the epoxy resin (a1) is in the range of 1.0 to 2.0, and the dispersity Mw / Mn of the epoxy resin (a2) is in the range of 2.1 to 5.0. Item 7. The epoxy polyol resin composition according to Item 6. The epoxy polyol resin composition according to claim 6, wherein a dispersion degree Mw / Mn of the mixture of the epoxy resin (a1) and the epoxy resin (a2) is in the range of 2.5 to 30.0. Furthermore, the epoxy polyol resin composition of any one of Claims 1-8 containing a hardening | curing agent (D). The epoxy polyol resin composition according to claim 9, wherein the curing agent (D) is an isocyanate compound.