JP2002097345A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a substituent of a BPA-type epoxy resin having functions equal or superior to the BPA-type epoxy resin and higher safety; and to provide a resin composition prepared by using the substituent, having high safety, excellent in coating film's physical properties such as processability and retort resistance, and suitable for the use in can coating. SOLUTION: The purpose is achieved by the following: a resin composition obtained though phosphoric acid esterification of a modified resin having a structure formed by reacting a novolak-type epoxy resin with a monovalent activated hydrogen compound; and an (aqueous) resin composition containing the modified resin phosphoric ester, an acrylic resin and/or a polyester resin, and an amino resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition comprising a novolak type epoxy resin modified phosphate ester as an essential component. This composition is a composition that does not generate BPA because it forms a coating film having excellent retort resistance, processability, and adhesion, and does not use BPA as a raw material.
In particular, it is extremely useful as a paint for cans for packaging foods and beverages.

[Prior art]

A BPA type epoxy resin synthesized from bisphenol A (BPA) and epichlorohydrin as raw materials has a function of forming a coating film having excellent workability and adhesion. It has been heavily used.

However, in recent years, it has been reported that BPA has an action of disrupting the endocrine activity of living organisms, and among the 67 substances on the list of "chemical substances suspected of having an endocrine disrupting action" published by the Environment Agency. Was mentioned. In response to this, elution of BPA from the coating film of the can to the contents (foods and beverages) has become a serious problem. The BPA eluted in the contents includes, in addition to those remaining in the epoxy resin, those generated by thermal decomposition during baking of the paint. Therefore, even if there is no residual amount of BPA in the epoxy resin, it is impossible to make the amount eluted into the contents zero. From such a background, a highly safe alternative having a function equal to or higher than that of the BPA type epoxy resin has been desired.

[Problems to be solved by the invention]

[0004] Therefore, the problem to be solved by the present invention is to find an alternative which has a function equal to or higher than that of a BPA type epoxy resin and does not use BPA as a raw material. An object of the present invention is to provide a resin composition which is high and is excellent in processability, retort resistance and the like, and suitable for can coating applications.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a substitute having a function equal to or higher than that of a BPA type epoxy resin and having a higher safety. And succeeded in completing the present invention.

That is, the present invention provides the following to solve the above problems. (1) A resin composition obtained by esterifying a modified resin having a structure obtained by reacting a novolak type epoxy resin with a monovalent active hydrogen compound with phosphoric acid.

(2) The monovalent active hydrogen compound is phenol and / or alkyl (1 to 4 carbon atoms) phenol, and the modified novolak epoxy resin has an epoxy equivalent of 600 to 3000 g / equivalent. The resin composition according to (1), wherein the equivalent ratio of phosphoric acid P-OH to the epoxy group of the epoxy resin is 0.3 to 1.0.

(3) A resin composition comprising the resin composition according to (1) or (2), an acrylic resin and / or a polyester resin, and an amino resin.

(4) An aqueous resin composition according to (3), wherein the acrylic resin and / or polyester resin is an aqueous resin.

The novolak-type epoxy resin without BPA according to the present invention is obtained by reacting a novolak resin without BPA with epihalohydrin. The epihalohydrin is not particularly limited, and includes, for example, epichlorohydrin and epibromohydrin. Epichlorohydrin is preferable from the viewpoint of productivity.

The novolak resin not using BPA is obtained by reacting a phenol compound other than BPA with formaldehyde. Examples of the phenol compound used include phenol and alkyl (C = 1 to 4) phenols. Examples of the alkyl phenol include o-
Cresol, m-cresol, p-cresol, p-s
-Butylphenol, pt-butylphenol and the like. Among them, o-cresol is preferable.

The synthetic route for obtaining a structure in which a part or all of the epoxy groups in the novolak epoxy resin without BPA according to the present invention are reacted with a monovalent active hydrogen compound is not particularly limited. For example, there are synthetic routes obtained by reacting a novolak type epoxy resin with a monovalent active hydrogen compound, and synthetic routes obtained by reacting a novolak resin with a monoglycidyl compound and then reacting with an epihalohydrin. Among them, a synthesis route obtained by reacting a novolak epoxy resin with a monovalent active hydrogen compound is preferable from the viewpoint of productivity. Examples of the monoglycidyl compound include, for example, alkyl glycidyl ethers such as butyl glycidyl ether, alkenyl monoglycidyl ethers such as allyl glycidyl ether, phenyl glycidyl ether, and alkyl phenyl such as pt-butylphenyl glycidyl ether. Examples thereof include monoglycidyl ethers and monoglycidyl esters such as glycidyl (meth) acrylate.

As the monovalent active hydrogen compound, for example,
Examples include monohydric phenols, monobasic acids, water, monohydric alcohols, and secondary amine compounds. Above all, monohydric phenols react with epoxy groups during synthesis,
It is preferable from the viewpoint of the stability of the obtained resin. As these monovalent active hydrogen compounds, not only can they be used alone, but there is no problem if two or more, for example, monohydric phenols and monobasic acid are used so as to simultaneously react with the epoxy resin.

Examples of the above-mentioned monovalent phenols (compounds having one phenolic hydroxyl group) include, for example, phenol and alkyl (C1-4) phenol. Examples of the alkyl phenol include o-cresol, m-cresol, p-cresol, p-s-butylphenol, pt-butylphenol and the like. Among them, phenol is preferred from the viewpoint of productivity.

Examples of monobasic acids include, for example, acetic acid, propionic acid, butyric acid, neodecanoic acid (versatic acid),
Alkyl (C1-C18) monocarboxylic acids such as stearic acid, or alkenyl (C2-C18) monocarboxylic acids such as acrylic acid, methacrylic acid, animal and vegetable oil fatty acids,
Examples thereof include hydroxyalkyl monocarboxylic acids such as lactic acid, and aromatic monocarboxylic acids such as benzoic acid. Above all,
Neodecanoic acid is preferred in terms of water resistance and processability of the cured product.

The reaction method of the epoxy group in the novolak type epoxy resin with the monovalent phenol compound is not particularly limited, but the novolak type epoxy resin and the monovalent phenol compound are charged into a reaction vessel, and the reaction catalyst is charged. Is added, and the mixture is heated and reacted under stirring in an inert gas atmosphere. Further, the reaction may be carried out using a reaction solvent. The reaction catalyst used for this reaction is not particularly limited, but, for example, sodium hydroxide, alkali metal hydroxides such as potassium hydroxide,
Alkali metal salts such as sodium carbonate, amines such as tributylamine, phosphines such as triphenylphosphine, quaternary ammonium compounds such as tetramethylammonium chloride, and quaternary phosphonium compounds such as tetrabutylphosphonium chloride. Any compound used as a reaction catalyst between an epoxy group and a phenolic hydroxyl group can be used. The reaction temperature of this reaction is 100 ° C. or more in that the reaction time can be shortened, and 250 ° C. in that the side reaction hardly occurs.
C. or less is preferred.

The epoxy equivalent of the phenol-modified epoxy resin obtained by the above reaction can be adjusted by the amount of reaction with a monovalent phenol compound. A preferable range of the epoxy resin is 600 to 3000 g / eq.
And a more preferred range is 600 to 1500. From the viewpoint of avoiding gelling in the esterification reaction with phosphoric acid, the epoxy equivalent is preferably 600 g / eq or more, while the content of the P-OH group in the product of the esterification reaction with phosphoric acid is reduced. The epoxy equivalent is preferably 3000 g / eq or less from the viewpoint of enhancing the function of the epoxy resin.

The phosphoric acid ester of the present invention can be used for the epoxy group 1 of an epoxy resin modified with a monovalent active hydrogen compound.
The reaction of phosphoric acid in such an amount that the P-OH of phosphoric acid becomes 0.3 to 1.0 equivalent to the equivalent is preferable from the viewpoint of improving the adhesion of a good formed film. If better adhesion of the formed film is required, the equivalent ratio between the epoxy group and the P-OH is preferably in the range of 1.0 / 0.5 to 1.0 / 1.0.

The phosphoric acid ester of the present invention can be synthesized, for example, by the following method. In an organic solvent solution of a phenol-modified epoxy resin whose liquid temperature was maintained at 75 ° C,
A 70% phosphoric acid aqueous solution is added dropwise for 1 hr, and the esterification reaction is performed at the same temperature until a predetermined acid value is reached. In some cases, the reaction can be carried out in the absence of a solvent or, if necessary, in the presence of a catalyst such as an amine compound such as 2-methylimidazole.

Although various solvents can be used as the solvent used as the reaction solvent, it is preferable to use a solvent that can dissolve the epoxy resin. Further, in order to maintain the adhesion of the formed film having the P-OH group to the underlying metal, a solvent which is not esterified with phosphoric acid such as an ether solvent or a ketone organic solvent is preferable. When the esterified product is used for an aqueous paint, a hydrophilic organic solvent is preferably used. For example, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, N
-Methylpyrrolidone, dimethylformamide and the like.

In order to increase the compatibility of the paint film,
After reacting a compound having a monovalent carboxyl group such as a saturated or unsaturated fatty acid with an epoxy resin modified with a phenolic compound as a monovalent active hydrogen compound that can be used in the present invention, phosphoric acid esterification is also possible. Good.

The phosphoric ester of the present invention is preferably used by mixing an acrylic resin and / or a polyester resin and an amino resin. The acrylic resin used in the present invention is a commonly used acrylic resin as a paint compounding agent. For example, a monomer copolymerizable with an alkyl (meth) acrylate such as methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, and stearyl (meth) acrylate Is a polymer obtained by copolymerization with Examples of the copolymerizable monomer used here include monocarboxylic acids such as (meth) acrylic acid, crotonic acid, and isocrotonic acid; dicarboxylic acids such as maleic acid (anhydride), fumaric acid, and itaconic acid (anhydride); Their anhydrides; monomethyl malate,
Monoethyl malate, monobutyl malate, mono-2-
Ethylhexyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, mono-2-
Ethylhexyl fumarate, monomethyl itaconate,
Monoalkyl esters of dicarboxylic acids such as monoethyl itaconate, monobutyl itaconate and mono-2-ethylhexyl itaconate; aromatic vinyl monomers such as styrene, α-methylstyrene and vinyl toluene; hydroxymethyl (meth) acrylate, 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as hydroxyhexyl (meth) acrylate; “Placcel FA-1 to FA-5”, “Placcel FM-1 to FM”
Caprolactone-modified (meth) acrylic esters having terminal hydroxyl groups, such as "-5" [product of Daicel Chemical Industries, Ltd.]; (meth) acrylamides such as (meth) acrylamide, diacetone (meth) acrylamide and the like; N-hydroxymethyl (meth) acrylamide, N
N-hydroxyalkyl (meth) acrylamides such as -hydroxyethyl (meth) acrylamide, N-hydroxybutyl (meth) acrylamide, etc .; N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N- (N-, iso-) butoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N- (n-, iso-) butoxyethyl (meth) acrylamide, etc. Vinyl monomers having a crosslinkable functional group other than a carboxyl group, such as N-alkoxyalkyl (meth) acrylamides.

As other copolymerizable vinyl monomers, only typical ones are exemplified, and methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, n-butoxymethyl (meth) A) an alkoxyalkyl (meth) acrylate such as acrylate, isobutoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, isobutoxyethyl (meth) acrylate;
Dimethyl malate, diethyl malate, dibutyl malate, di-2-ethylhexyl malate, dimethyl fumarate, diethyl fumarate, dibutyl fumarate, di-
Dialkyl esters of dicarboxylic acids such as 2-ethylhexyl fumarate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, di-2-ethylhexyl itaconate; carboxylic acids such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate Vinyl esters such as vinyl acetate, vinyl propionate, and tertiary carboxylate; various heterocyclic vinyl compounds such as vinylpyrrolidone; (meth) acrylonitrile;
Vinyl chloride, vinyl pyrrolidone, vinyl ether, vinyl ketone and the like; various vinylidene halide compounds such as vinylidene chloride and vinylidene fluoride; various α-olefins such as ethylene and propylene; It may be used or two or more kinds may be used in combination.

The aqueous acrylic resin is obtained by radical polymerization of a vinyl monomer mixture containing the above-mentioned carboxyl group-containing vinyl monomer as an essential component, and the obtained copolymer is completely polymerized with ammonia or a volatile organic amine. Alternatively, it is obtained by partially neutralizing and dissolving or dispersing in water or a mixture with a water-soluble solvent.

As an example of the above organic amine,
Various alkylamines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine, isobutylamine, dipropylamine; monoethanolamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine , N, N-diethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-
Various amino alcohols such as propanol, N-methyldiethanolamine, N-ethyldiethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine; various organic amines such as morpholine; Organic amines having a boiling point of 80 to 180 ° C., such as N, N-dimethylethanolamine, are particularly preferred. However, in order to control the water-solubility of the resin, various compounds as described above may be used in appropriate combination. Can also.

The polyester resins usable in the present invention are those which are known and commonly used for coatings, which are synthesized by a polycondensation reaction (esterification reaction) of fats and oils, fatty acids, polybasic acids and polyhydric alcohols. This polycondensation reaction may be performed under normal pressure or under reduced pressure, and the molecular weight can be adjusted by adjusting the charging ratio of the polybasic acid and the polyhydric alcohol.

Examples of the dibasic acids that can be used in the synthesis of the polyester resin of the present invention include aromatic dibasic acids such as terephthalic acid, isophthalic acid and phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4
-Alicyclic dibasic acids such as cyclohexanedicarboxylic acid,
Also, (anhydride) succinic acid, fumaric acid, (anhydride) maleic acid,
Examples thereof include aliphatic dibasic acids such as adipic acid, sebacic acid, azelaic acid, and hymic acid. Examples of the polybasic acid include trimellitic acid (anhydride), trimesic acid, and pyromellitic acid (anhydride). When synthesizing,
The amount of polybasic acid can be adjusted to control the degree of branching and molecular weight of the resulting resin, and the type of dibasic acid can be appropriately selected and used in consideration of the hardness and flexibility of the coating film.

Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, neopentyl glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,
2,4-trimethyl-1,3-pentanediol, 2-
Ethyl-1,3-hexanediol, 2-diethyl-
1,3-propanediol, 1,9-nonanediol,
2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, xylene glycol, dimer diol [Toa Synthetic Co., Ltd .; aliphatic dihydric alcohols such as Vespol HP-1000], and compounds corresponding to dihydric alcohols such as glycidyl versatate and ε-caprolactone. Any of these can be appropriately selected and used. Examples of the trivalent or higher alcohol include trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol. At the time of synthesis, the degree of branching of the formed resin, the amount of polyhydric alcohol is adjusted to control the molecular weight, and the hardness and flexibility of the coating film are taken into consideration, and the type of polyhydric alcohol is appropriately selected. good.

The polyester resin obtained by the above polycondensation reaction is preferably provided in the form of a solution dissolved in a solvent in the preparation of a coating from the viewpoint of workability. This solvent can be used without limitation as long as it can dilute the polyester resin. For example, aromatic hydrocarbons such as toluene, xylene, Solvesso # 100 and Solvesso # 150, aliphatic hydrocarbons such as hexane, heptane, octane and decane, methyl acetate, ethyl acetate, isopropyl acetate, amyl acetate butyl acetate and formic acid Ester type such as ethyl and butyl propionate, alcohol type such as methanol, ethanol, propanol, butanol, 2-ethylhexanol and ethylene glycol, ketone type such as acetone, methyl ethyl ketone and cyclohexanone, ether type such as dioxane, diethyl ether and tetrahydrofuran And various solvents such as cellosolves such as cellosolve acetate, ethyl cellosolve and butyl cellosolve. The solid content concentration of the polyester resin solution is usually 20 to 70% by weight, preferably 30 to 60% by weight. 70% by weight or less is preferred in terms of handling of the resin solution, and 20% by weight or more is preferred in that the viscosity of the prepared paint does not become too low.

The aqueous polyester resin of the present invention may be a synthetic reaction or an acid having a predetermined molecular weight, which is blended and designed to obtain a predetermined molecular weight when the acid value at the end of the esterification reaction is 30 to 70 KOH mg / g. Price 0-30KOHm
g / g of a predetermined amount of phthalic anhydride to a polyester resin,
The product obtained by the addition reaction of an anhydride such as trimellitic anhydride is diluted with a hydrophilic solvent such as an alcohol-based solvent, completely or partially neutralized with a volatile organic amine, and then dissolved in water. Alternatively, it is obtained by dispersing.

In the resin composition of the present invention, it is preferable to use an amino resin as an additional component. The amino resin used is not particularly limited as long as it is an amino resin having a crosslinkable functional group capable of reacting with the crosslinkable functional group (hydroxyl group, carboxyl group, alkoxy group, etc.) of the acrylic resin and polyester, For example, an amino resin having an alkoxy group, an alkylol group, an imino group, a carboxyl group, or the like can be given.

Examples of the amino resin having a crosslinkable functional group capable of reacting with the crosslinkable functional group of the acrylic resin or polyester resin include, for example, urea, melamine, benzoguanamine, cyclohexanecarboguanamine, steroganamin, spiroguanamine, acetoguanamine, Phthaloganamin, 2- (4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid, 3-
(4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid, 4- (4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid and the like A so-called amino group-containing compound such as
Compounds that can be obtained by addition condensation with an aldehyde compound and at the same time etherification with a monohydric alcohol can be given.

Among the above-mentioned amino group-containing compounds, those containing benzoguanamine as an essential component are particularly desirable from the viewpoints of retort resistance, reduction of the amount of tans generated in a drying oven and glossiness.

The aldehyde compound used in the synthesis of the amino resin includes, for example, formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, glyoxal and the like.

[0035] Formaldehyde, paraformaldehyde, and glyoxal are preferably used alone or in combination with each other from the viewpoint of cost, reactivity and the like.

Next, the above-mentioned monohydric alcohol used in the synthesis of an amino resin is obtained by reacting a reaction product of a compound having an amino group (an amino group-containing compound) with a compound having an aldehyde group (an aldehyde compound). It is necessary for stabilization. Among them, methyl alcohol, ethyl alcohol, n-propyl alcohol, iso (iso-) propyl alcohol,
n-butyl alcohol, isobutyl alcohol, sec
-Butyl alcohol, tert-butyl alcohol, n
-Amyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether; allyl alcohol, and the like. Used alone or in combination.

Among them, methyl alcohol,
n-Butyl alcohol, isobutyl alcohol, isopropyl alcohol are particularly preferably used.

In order to obtain the amino resin used in the present invention, various known and commonly used production methods can be used. For example, the aldehyde compound is added in an amount of 1.0 mol based on 1.0 mol of the amino group-containing compound. The monohydric alcohol is used at a ratio of 4.0 to 20.0 mol at a ratio of 5 to 8.0 mol, and the monohydric alcohol is added to the solution in the form of adding an aldehyde compound to the monohydric alcohol. Further, the amino group-containing compound is treated with an acidic catalyst in the range of 40 to 120.
The reaction may be carried out at a temperature of 20 ° C. for 20 to 300 minutes, and the condensation reaction and the etherification reaction may be performed simultaneously.

In the production of the amino resin, it is preferable to check the viscosity, the molecular weight, and the like, and to terminate the reaction when the desired spec value is reached.

The amount of each resin in the resin composition of the present invention is desirably set as follows in order to satisfy various performances required for a covering material for a can. The ratio of the acrylic resin and / or the polyester resin to the amino resin is 90/10 to 10/90, preferably 70/30 to 40.
/ 60. The ratio of the phosphoric acid ester to the other resin component is from 30/70 to 1/99, preferably from 15/70 to 1/99.
/ 85 to 1/99.

Acrylic resin generally has excellent hardness of the formed film and resistance to retort sterilization, while polyester resin has excellent workability. Therefore, in order to take advantage of both features, it is possible to use a mixture of an acrylic resin and a polyester resin and a curing agent in combination depending on the purpose of use and required performance. The ratio of the acrylic resin to the polyester resin is 90/10 to 10/90, preferably 70/30 to 40/60. For example, when obtaining workability of a formed film, the polyester resin ratio may be increased. In addition, an acrylic / polyester graft resin may be used for the purpose of achieving both resistance to retort sterilization and workability. This acrylic / polyester graft resin is obtained by adding an acrylic monomer and an α-β unsaturated monomer such as maleic acid, itaconic acid and methacrylic anhydride to an alkyd resin derived from unsaturated oil and its fatty acid. , Β-unsaturated monomers and the like.

The main functions of the phosphoric acid ester of the present invention are to improve the strength of the coating and the adhesion to the metal base, but considering these functions and the compatibility with other resin components,
Suitable amounts of the phosphoric acid ester are as described above.

Each of the above resin products is not limited to a so-called solvent-based paint using an organic solvent as a solvent, but may be an aqueous (water-soluble or water-dispersed) paint using an aqueous acrylic resin and / or an aqueous polyester resin. It is also applied in other curing composition applications.

In these resin compositions, an acid catalyst such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid or an amine salt thereof is used as a curing catalyst in order to accelerate the curing by the amino resin. 0.1 parts per 100 parts of resin solids.
Addition of up to 1.0 part is preferred.

Further, to the resin composition of the present invention, various additives such as pigments, plasticizers, colorants, and flow regulators can be added in appropriate amounts as needed.

Now, the present invention will be described in further detail with reference to Production Examples, Comparative Production Examples, Examples and Comparative Examples, but it should be understood that the present invention is by no means limited to only these exemplifications. Not something. In the following, parts and%
All are by weight unless otherwise specified.

Production Example 1 [Synthesis of phenol-modified novolak type epoxy resin (A-1)] An o-cresol novolak type epoxy resin, EPICLON was placed in a reaction vessel equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. , N-673 [manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 210 g / eq. 729 parts of phenol and 271 parts of phenol, and 0.60 part of a 50% aqueous solution of tetramethylammonium chloride as a reaction catalyst was added.
Allowed to react for hours. The epoxy equivalent of the obtained resin was 195.
0 g / eq. Met. Hereinafter, this is abbreviated as modified epoxy resin (A-1).

Production Example 2 [Synthesis of phenol-modified novolak type epoxy resin (A-2)] Into the above-mentioned reaction vessel were charged 767 parts of o-cresol novolak type epoxy resin, (EPICLONN-673) and 233 parts of phenol, and a reaction catalyst was prepared. 0.20 parts of a 50% by weight aqueous solution of tetramethylammonium chloride as
The reaction was performed at 140 ° C. for 9 hours under a nitrogen atmosphere. The epoxy equivalent of the obtained resin was 905 g / eq. Met. Hereinafter, this is abbreviated as modified epoxy resin (A-2).

Production Example 3 [Synthesis of phenol-modified novolak type epoxy resin (A-3)] Into the above reaction vessel, 796 parts of o-cresol novolak type epoxy resin, (EPICLONN-673) and 204 parts of phenol were charged and a reaction catalyst was prepared. 0.20 parts of a 50% by weight aqueous solution of tetramethylammonium chloride as
The reaction was performed at 140 ° C. for 7 hours under a nitrogen atmosphere. The epoxy equivalent of the obtained resin was 640 g / eq. Met. Hereinafter, this is abbreviated as modified epoxy resin (A-3).

Production Example 4 [Synthesis of phosphoric acid ester (B-1)] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel, a modified epoxy resin (A-
1) 494.1 parts and 500.0 parts of ethylene glycol dimethyl ether were charged and heated and dissolved. While maintaining the solution temperature at 75 ° C., 5.9 parts of a 70% aqueous phosphoric acid solution was continuously dropped from the dropping funnel over 1 hour. 1 at the same temperature
The mixture was reacted for 5 hours, and the acid value of the solid content was 18 mgKOH / g,
A phosphoric acid ester solution having a nonvolatile content of 50.1% was obtained. Hereinafter, this is abbreviated as phosphoric acid ester (B-1).

Production Example 5 [Synthesis of phosphoric acid ester (B-2)] In the same reaction vessel as above, the modified epoxy resin (A-2)
92.4 parts and ethylene glycol dimethyl ether 5
00.0 parts and heated and melted. While maintaining the solution temperature at 75 ° C., 7.6 parts of a 70% phosphoric acid aqueous solution was continuously dropped from the dropping funnel over 1 hour. The mixture was reacted at the same temperature for 15 hours to obtain a phosphoric acid ester solution having an acid value of 10 mgKOH / g and a non-volatile content of 50.2%. Hereinafter, this is abbreviated as phosphoric acid ester (B-2).

Production Example 6 [Synthesis of phosphoric acid ester (B-3)] In the same reaction vessel as above, the modified epoxy resin (A-2)
87.4 parts and ethylene glycol dimethyl ether 5
00.0 parts and heated and melted. While maintaining the solution temperature at 75 ° C, a 70% phosphoric acid aqueous solution 1 was dropped from the dropping funnel.
2.6 parts were continuously dropped over 1 hour. The reaction was carried out at the same temperature for 15 hours to obtain a phosphoric acid ester solution having a solid content acid value of 13 mgKOH / g and a nonvolatile content of 50.5%. Hereinafter, this is abbreviated as phosphoric acid ester (B-3).

Production Example 7 [Synthesis of phosphoric acid ester (B-4)] In the same reaction vessel as above, modified epoxy resin (A-2) 4
75.6 parts and ethylene glycol dimethyl ether 5
00.0 parts and heated and melted. While maintaining the solution temperature at 75 ° C., a 70% phosphoric acid aqueous solution 2 was dropped from the dropping funnel.
4.4 parts were continuously dropped over 1 hour. The mixture was reacted at the same temperature for 15 hours to obtain a phosphoric acid ester solution having a solid content of 20 mgKOH / g and a nonvolatile content of 50.3%. Hereinafter, this is abbreviated as phosphoric acid ester (B-4).

Production Example 8 [Synthesis of phosphoric acid ester (B-5)] In the same reaction vessel as above, the modified epoxy resin (A-3) 4
82.4 parts and ethylene glycol dimethyl ether 5
00.0 parts and heated and melted. While maintaining the solution temperature at 75 ° C, a 70% phosphoric acid aqueous solution 1 was dropped from the dropping funnel.
7.6 parts were continuously dropped over 1 hour. The mixture was reacted at the same temperature for 11 hours to obtain a phosphoric acid ester solution having a solid content acid value of 16 mgKOH / g and a nonvolatile content of 51.7%. Hereinafter, this is abbreviated as phosphoric acid ester (B-5).

Table 1 shows the epoxy equivalents of the phenol-modified epoxy resin and the equivalent ratio of the resin to phosphoric acid in Production Examples 4 to 8 described above.

Production Example 9 [Phosphate compound (B-6)
Synthesis of bisphenol A type epoxy resin, EPICLON 1055 [epoxy equivalent 475 g / eq, manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 475 g / eq] 476.4 parts and ethylene glycol dimethyl ether 500.0 parts were charged into the same reaction vessel as above. Heated and melted. While maintaining the solution temperature at 75 ° C., 23.6 parts of a 70% phosphoric acid aqueous solution was added from a dropping funnel to 13.6 parts.
It was dripped continuously over time. Let react at the same temperature for 8 hours,
Solid acid value: 30 mg KOH / g, non-volatile content: 51.1
% Phosphoric acid ester solution was obtained. Hereinafter, this is abbreviated as phosphoric acid ester (B-6).

Production Example 10 [Synthesis of Acrylic Resin (C-1)] 400 parts of ethylene glycol monobutyl ether was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel. The temperature was raised to ° C. From the dropping funnel, 40 parts of ethyl acrylate, 40 parts of n-butyl acrylate, 50 parts of 2-ethylhexyl acrylate, 135 parts of methyl methacrylate, 40 parts of 2-hydroxyethyl methacrylate, and N- (methoxymethyl) A) a mixture of 80 parts of acrylamide, 15 parts of acrylic acid and 6 parts of benzoyl peroxide
It was dripped continuously over time. One hour after the end of the dropping,
4 parts of rt-butyl peroxide are added and for a further 2 hours
The reaction was performed at the same temperature. The properties of the resulting resin solution were such that the nonvolatile content was 50.8%, the viscosity (Gardner bubble viscosity at 25 ° C.) was Z, and the weight average molecular weight was 18,000. Hereinafter, this is abbreviated as acrylic resin (C-1).

Production Example 11 [Aqueous acrylic resin (C-2)
Synthesis of 400 parts of ethylene glycol monoisopropyl ether was charged into a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel, and the temperature was raised to 120 ° C. From the dropping funnel, 40 parts of ethyl acrylate, 40 parts of n-butyl acrylate, 50 parts of 2-ethylhexyl acrylate, 120 parts of methyl methacrylate, 40 parts of 2-hydroxyethyl methacrylate, and N
A mixture consisting of 80 parts of (methoxymethyl) acrylamide, 30 parts of acrylic acid, and 12 parts of benzoyl peroxide was continuously dropped over 4 hours. One hour after the completion of the dropwise addition, 4 parts of di-tert-butyl peroxide was added, and the mixture was further reacted at the same temperature for 2 hours. After evaporating 300 parts of ethylene glycol monoisopropyl ether from the resulting resin solution under reduced pressure, the remaining solution was neutralized with 37 parts of diethanolamine and diluted with 263 parts of ion-exchanged water to obtain an aqueous acrylic resin solution. . The resin solution had a nonvolatile content of 50.3% and a viscosity (Gardner bubble viscosity of 2).
5 ° C.) was Z, and the weight average molecular weight was 8,000. Hereinafter, this is abbreviated as acrylic resin (C-2).

Production Example 12 [Polyester resin (D-1)
Synthesis of isophthalic acid 58. Isophthalic acid in a reaction vessel equipped with a stirrer, thermometer, rectification tube, decanter, reflux cooling tube and nitrogen inlet tube.
6 parts, terephthalic acid 410.2 parts, adipic acid
1 part, 162.2 parts of neopentyl glycol, 2-n-
Butyl-2-ethyl-1,3-propanediol 37
Charge 4.4 parts and 1 part of dibutyltin oxide 160
The contents were melted by heating to ° C. From the same temperature, the temperature was raised to 240 ° C. over 3 hours while distilling the condensed water out of the system. After reacting at the same temperature for 2 hours, the decanter was filled with xylene, 15 parts of xylene was added to the reactor, and the condensation reaction was further continued under xylene reflux.

The acid value of the reaction product is 10.0 mgKOH / g
When the temperature reached, cooled to 180 ° C, Solvesso # 1
Was added, and 280.3 parts of butyl cellosolve was added to obtain a polyester resin solution. The resin solution had a nonvolatile content of 50.3%, a viscosity (Gardner bubble viscosity of 25 ° C.) of QR, and an acid value (solid content) of 4.9 mgKOH / g. The hydroxyl value (solid content) is 46 and the number average molecular weight is 150
It was 0. Hereinafter, the polyester resin (D-1)
Abbreviated.

Production Example 13 [Aqueous polyester resin (D-
Synthesis of 2)] phthalic anhydride 610 was added to a reaction vessel equipped with a stirrer, a thermometer, a rectification tube, a decanter, a reflux cooling tube, and a nitrogen introduction tube.
Part, 177 parts of adipic acid, 1,6-hexanediol 4
84 parts and trimethylolpropane 130 parts were charged.
The contents were heated to 0 ° C. to melt. From the same temperature, the temperature was raised to 190 ° C. over 3 hours while distilling the condensation water out of the system. The reaction was carried out at the same temperature for 6 hours.

The acid value of the reaction product is 50.0 mgKOH / g
Was reached and cooled to 130 ° C., and 415 parts of ethylene glycol monoisopropyl ether was added to obtain a uniform solution. The temperature was further lowered to 90 ° C., neutralized with 103 parts of diethanolamine, and then diluted with 778 parts of ion-exchanged water to obtain an aqueous polyester resin solution. The resin solution had a nonvolatile content of 49.1%, a viscosity (Gardner bubble viscosity of 25 ° C.) of W, and an acid value (solid content) of 51.5 mg KOH.
/ G, hydroxyl value (solid content) was 70.0 mgKOH / g. Hereinafter, this is abbreviated as polyester resin (D-2).

Production Example 14 [Synthesis of Amino Resin (E)] In a reaction vessel equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 320.0 parts of methyl alcohol, 80
After charging 112.5 parts of paraformaldehyde and 187.0 parts of benzoguanamine, the pH was adjusted to 10.0 with a 5N aqueous sodium hydroxide solution, and the temperature was raised to 70 ° C.

After the methylolation reaction was carried out at this temperature for 2 hours, the pH was adjusted to 3.0 with a 50% aqueous sulfuric acid solution, and the etherification reaction was carried out at 70 ° C. for 4 hours. After adjusting the pH to 7.0 with an aqueous sodium hydroxide solution, a total of 350.5 parts of methyl alcohol, formaldehyde and water were distilled off under reduced pressure.

Finally, the mixture was diluted with 65 parts of ethylene glycol monobutyl ether, and the precipitated salts were filtered off.
Non-volatile content 80.3%, viscosity (Gardner bubble viscosity 25
C)), the number of colors was 1 or less, and the peak area of the mononuclear portion measured by size exclusion chromatography was 50% of the total peak area of the amino resin, thereby obtaining a methyl etherified benzoguanamine resin. Hereinafter, this is abbreviated as amino resin (E).

The size exclusion chromatography is based on the size exclusion chromatography described in JIS K0124 High-speed Chromatography.
The solution was measured using tetrahydrofuran, and the filler was measured using polystyrene gel.

(Test Example 1) The phosphoric acid ester described in Table 1 was used and a paint was blended according to the solid composition shown in Tables 2 and 3. For Examples b1, b3, b5 and Comparative Example 3, ethylene glycol monobutyl ether / solvesso 10
Using a mixed solvent of 0 = 1/1, the solid content was adjusted to 50%. Further, in Examples a1 to a5, b2 and b4 and Comparative Examples 1 and 2, the solid content was 40%,
It was adjusted with ethylene glycol monoisopropyl ether and ion-exchanged water so that the content was 0%. To 100 parts of each formulation, 0.3 part of p-toluenesulfonic acid was added to prepare paints of Examples and Comparative Examples, and a coating film performance test (appearance, Hot water resistance, retort resistance, pencil hardness, workability, and adhesion). The evaluation results of various physical properties are summarized in Tables 4 and 5.

<< Procedure for Evaluation and Judgment of Various Performances >> The procedure for each test is as follows.

1. Coating film performance test Each of the coatings of Examples and Comparative Examples was 100 mm long and 100 mm wide.
on a tin plate having a thickness of 0.23 mm and a coating thickness (film thickness) of 60 mg / 100 cm ² with a bar coater, followed by heating and drying at 180 ° C. for 10 minutes. The coated panels were used as test panels, respectively, as follows.

(Appearance of Coating Film) The transparency of the panel was evaluated and evaluated visually by the following criteria. No change on the paint film ◎◎ The cloudy area of the paint film is less than 3% of the total area ・ ・ ・ ○ The cloudy area of the paint film is less than 10% of the total area ・ ・ ・ △ The cloudy area of the paint film Is 10% or more of the total area ... ×

(Hot Water Resistance) Each test panel was immersed separately in boiling water for 30 minutes, and the state of the coating film was visually evaluated according to the following criteria. No change on coating film ◎◎ Bleaching / blister area is less than 3% of total area ・ ・ ・ ○ Bleaching / blister area is less than 10% of total area ・ ・ ・ △ Bleaching / blister area is total area 10% or more of ×

(Retort resistance) 130 ° C. with high-pressure steam
In an autoclave that was heated to
The state of the coating film after standing for 0 minutes was visually evaluated and determined according to the following criteria. No change on coating film ◎◎ Bleaching / blister area is less than 3% of total area ・ ・ ・ ○ Bleaching / blister area is less than 10% of total area ・ ・ ・ △ Bleaching / blister area is total area 10% or more of ×

(Pencil Hardness) In accordance with JIS K-5400, a pencil scratch value at room temperature was measured for each test panel after the retort resistance test.
Evaluation judgment was performed.

(Workability) In accordance with JIS K-5400, for each test panel after the retort resistance test,
An Erichsen test (6.0 mm) was performed, and the evaluation was visually judged according to the following criteria. No change on the coating film ◎◎ Crack / film peeling area is less than 1% of total area ・ ・ ・ ○ Crack / film peeling area is less than 5% of total area ・ ・ ・ 面積 Crack / film peeling area Is 5% or more of the whole area ・ ・ ・ ×

(Adhesion) According to the JIS K-5400 grid tape method, 100 squares of 1 mm × 1 mm were formed on each test panel after the retort resistance test, and an adhesive cellophane tape was applied to the surface thereof. Evaluation was determined by measuring the number of cross-cut coating films remaining on the coated surface after sticking and sharply peeling off.

[0075]

[Table 1]

(*) In Table 1 indicates the number of equivalents per equivalent of the epoxy group of the phenol-modified epoxy resin.

[0077]

[Table 2]

The numerical values in the paint formulations in Tables 2 and 3 indicate the solid weight ratio.

[0079]

[Table 3]

(*) In Table 3 indicates EPICLON 105
5; manufactured by Dainippon Ink and Chemicals, Inc. (bisphenol A)
Solid epoxy resin, epoxy equivalent 475 g / eq).

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

According to the present invention, the resin composition for a paint containing a phosphoric acid ester of the present invention uses a BPA which forms a coating film having excellent retort resistance, processability, adhesion and the like, and has a problem in safety. Since it is not used, it is particularly useful as a paint for cans for packaging foods and beverages.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shuichi Koshizawa 3-3-1-303 Iizuka, Kawaguchi-shi, Saitama F-term (reference) 4J002 BG032 BG042 BG062 BH022 CC132 CC182 CC192 CD20W CF002 CF032 CF042 CF052 CF062 CF072 CF082 GH01 4J036 AF06 AF07 AF08 CA07 CA18 CA21 CA25 CA26 CC02 FB03 FB09 FB11 JA01 KA01

Claims (4)

[Claims] 1. A resin composition characterized in that a resin obtained by esterifying with a phosphoric acid a modified resin having a structure obtained by reacting a novolak type epoxy resin containing no bisphenol with a monovalent active hydrogen compound is used as an essential component. object. 2. The monovalent active hydrogen compound is phenol and / or alkyl (1 to 4 carbon atoms) phenol,
The modified novolak type epoxy resin has an epoxy equivalent of 600 to 3000 g / equivalent, and the equivalent ratio of phosphoric acid P-OH to the epoxy group of the epoxy resin is 0.1 g.
The resin composition according to claim 1, wherein the ratio is 3 to 1.0. 3. The resin composition according to claim 1, further comprising an acrylic resin and / or a polyester resin, and an amino resin. 4. The aqueous resin composition according to claim 3, wherein the acrylic resin and / or the polyester resin is an aqueous resin.