JP2018172520A - Epoxy resin composition, and hydrophilic coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition capable of forming a coating film having opposite characteristics of hydrophilicity and water resistance, and a hydrophilic coating agent made of the resin composition.SOLUTION: An epoxy resin composition contains an epoxy compound (A) represented by general formula (1); G-O-(CHO)-G (1) (G indicates a glycidyl group, k indicates 2 or 3, and l indicates an average of repeating numbers and 1-50.), an epoxy compound (B) represented by general formula (2); (G-O-(CHO))-X-(O-G)(2) (X indicates a residue obtained by removing hydroxy groups from a polyhydric alcohol of (p+q) valences having 3-6 carbons, p indicates 1-6, q indicates 0-5, (p+q) indicates 3-10, G's indicate each independently a glycidyl group or a hydrogen atom, m indicates 2 or 3, and n indicates an average of repeating numbers and 1-50.), and a hardening agent (C).SELECTED DRAWING: None

Description

The present invention relates to an epoxy resin composition and a hydrophilic coating agent comprising the resin composition.

In the hydrophilization treatment of fibers, metals, resins, etc., a technology for coating with water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose (CMC), and hydrophilic epoxy resins such as long-chain PEG glycidyl ether has been developed. (Patent Document 1). However, although the hydrophilicity can be improved by using a hydrophilic epoxy resin, there is a problem that the water resistance is lowered.

On the other hand, a method of blending a cationic fine particle gel with a polyfunctional epoxy resin is also known (Patent Document 2). However, the hydrophilicity and water resistance of the treated surface are in a trade-off relationship, and there is a problem that both characteristics cannot be sufficiently achieved.

JP 2003-113240 A JP 2000-281867 A

An object of this invention is to provide the epoxy resin composition which can form the coating film which has the characteristic which conflicts hydrophilicity and water resistance, and the hydrophilic coating agent which consists of this resin composition.

The present inventors have made various studies on the epoxy compound to be blended in the epoxy resin composition, and contain a long-chain polyoxyalkylene diglycidyl ether, a long-chain polyoxyalkylene polyvalent glycidyl ether, and a curing agent. It was found that by using an epoxy resin composition, a hydrophilic coating film having both hydrophilicity and water resistance can be provided, and the present invention has been completed.

That is, the present invention provides (A) the following general formula (1);
_{G-O- (C k H 2k} O) l -G (1)
(G represents a glycidyl group, k is 2 or 3, l is the average number of repetitions and is 1 to 50),
(B) the following general formula (2);
_{(G-O- (C m H} 2m O) n) p -X- (O-G) q (2)
(X is a residue obtained by removing a hydroxyl group from a (p + q) -valent polyhydric alcohol having 3 to 6 carbon atoms, p is 1 to 6, q is 0 to 5, and (p + q) is 3 to 10. , G each independently represents a glycidyl group or a hydrogen atom, m is 2 or 3, n is an average of the number of repetitions and is 1 to 50), and
(C) It relates to an epoxy resin composition containing a curing agent.

The epoxy compound (B) is preferably an epoxy compound having n × p of 1 to 50 in the general formula (2).

The epoxy compound (A) is preferably a polyethylene glycol skeleton epoxy compound in which k is 2.

The epoxy compound (B) is preferably an epoxy compound having a polyethylene glycol chain in which m is 2.

The present invention also relates to a hydrophilic coating agent containing the epoxy resin composition and an article coated with the hydrophilic coating agent.

Since the epoxy resin composition of the present invention contains a divalent epoxy compound and a trivalent or higher polyvalent epoxy compound, both the hydrophilicity and water resistance, which are contradictory properties, can be achieved.

The hydrophilic coating composition of the present invention comprises (A) the following general formula (1);
_{G-O- (C k H 2k} O) l -G (1)
(G represents a glycidyl group, k is 2 or 3, l is the average number of repetitions and is 1 to 50),
(B) the following general formula (2);
_{(G-O- (C m H} 2m O) n) p -X- (O-G) q (2)
(X is a residue obtained by removing a hydroxyl group from a (p + q) -valent polyhydric alcohol having 3 to 6 carbon atoms, p is 1 to 6, q is 0 to 5, and (p + q) is 3 to 10. , G each independently represents a glycidyl group or a hydrogen atom, m is 2 or 3, n is an average of the number of repetitions and is 1 to 50), and
(C) It contains a curing agent.

About the epoxy compound (A) represented by General formula (1), l in General formula (1) is 1-50, However, 10-30 are preferable and 20-25 are more preferable. When l is 0, hydrophilicity cannot be obtained, and when l exceeds 50, the reactivity is poor due to a decrease in the epoxy content, and water resistance tends to be difficult to obtain due to insufficient reaction. k is preferably 2 in terms of hydrophilicity. Specific examples of the epoxy compound include polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

In the epoxy compound (B) represented by the general formula (2), X in the general formula (2) is a residue obtained by removing a hydroxyl group from a (p + q) -valent polyhydric alcohol having 3 to 6 carbon atoms. Examples of the alcohol include trimethylolpropane, glycerin, pentaerythritol, sorbitol and the like. Although p is 1-6, 3-6 are preferable and q is 0-5, However, 0-1 are preferable. (P + q) is 3 to 10, preferably 3 to 6. When p is 0 or q exceeds 5, the hydrophilicity tends to be insufficient. Although n is 1-50, 1-20 are preferable and 1-10 are more preferable. When n is 0, hydrophilicity is insufficient, and when n exceeds 50, water resistance tends to be insufficient. m is preferably 2 in terms of hydrophilicity.

The epoxy compound (B) is preferably an epoxy compound having n × p of 1 to 50 in the general formula (2). Here, n × p means the total number of moles of alkylene oxide represented by C _m H _2m O in one epoxy compound (B) represented by the general formula (2). As for nxp, 5-40 mol is more preferable, and 10-30 mol is further more preferable. G is present in an amount of 3 to 10 in one molecule of the epoxy compound (B), but 2 to 10 of G contained in one molecule is preferably a glycidyl group, and all Gs are glycidyl groups. More preferred.

Although the manufacturing method of an epoxy compound (B) is not specifically limited, For example, after adding a polyoxyalkylene chain to one part or all part of the hydroxyl group of a polyhydric alcohol, it is obtained by further glycidyl-etherifying. Specific examples of the epoxy compound include trimethylolpropane EO-added triglycidyl ether, sorbitol EO-added polyglycidyl ether, and the like.

The content of the epoxy compound (A) and the epoxy compound (B) is preferably 1:99 to 99: 1, more preferably 10:90 to 90:10, and even more preferably 25:75 to 75:25. If the content of the epoxy compound (A) is less than 1, the hydrophilicity is insufficient, and if it exceeds 99, the water resistance tends to be insufficient.

The curing agent (C) is not particularly limited as long as it is a curing agent capable of reacting with an epoxy group. For example, 2-ethyl-4-methylimidazole, diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, boron trifluoride-amine complex, guanidine derivative, dicyandiamide, linolenic acid dimer and ethylenediamine Polyamide resins synthesized by amine, urethane resins having amine groups in the molecule, amine curing agents such as melamine resins, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyl Carboxylic acid-based curing agents such as tetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, acrylic resins having a carboxylic acid group such as polyacrylic acid, From acid curing agents such as tan resin and polyester resin, phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, polyvalent hydroxy compound and formaldehyde Synthesized polyhydric phenol novolak resin, naphthol aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol phenol co-condensed novolac resin, naphthol cresol co-condensed novolak resin, biphenyl modified phenol resin, biphenyl modified naphthol Examples thereof include phenolic curing agents such as resins, aminotriazine-modified phenol resins, and alkoxy group-containing aromatic ring-modified novolak resins. These may be used alone or in combination of two or more. Especially, an amine type hardening | curing agent and an acid type hardening | curing agent are preferable at a highly reactive point with an epoxy group.

Content of a hardening | curing agent (C) is not specifically limited, If it is the quantity normally mix | blended in an epoxy resin composition, there will be no problem, the epoxy equivalent of the epoxy compound contained in an epoxy resin composition, and various hardening | curing agents It may be set as appropriate in consideration of the formulation rules, but is preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, based on 100 parts by weight of the total of the epoxy compound (A) and the epoxy compound (B). If it is less than 1 part by weight, the curing agent is insufficient and curing is insufficient, and if it exceeds 200 parts by weight, the epoxy characteristics tend to be difficult to obtain.

In addition to the above components, the epoxy resin composition may contain other optional components as necessary. Examples of other optional components include fillers, curing accelerators, organic solvents, and adhesion promoters. Solvents, curing accelerators, antifoaming agents, leveling agents, organic thickeners, antioxidants, light stabilizers, adhesion improvers, mold release agents, reinforcing materials, softeners, colorants, flame retardants, electrification Examples thereof include an inhibitor and a wetting and dispersing agent.

The filler is not particularly limited, and a known filler can be used. Examples thereof include inorganic oxides, inorganic salts, glass, nitrides, metal powders, and the like, and these include epoxy resin compositions. What is necessary is just to select suitably according to a use. The inorganic oxide is not particularly limited, and examples thereof include titanium oxide, silicon oxide, aluminum oxide, beryllium oxide, and zirconium oxide. The inorganic salt is not particularly limited, and examples thereof include calcium carbonate, barium sulfate, zirconium silicate, calcium silicate, magnesium silicate and the like. The nitride is not particularly limited, and examples thereof include boron nitride, aluminum nitride, gallium nitride, indium nitride, and silicon nitride. It does not specifically limit as metal powder, For example, silver powder, copper powder, silver plating copper powder, tin plating copper powder, nickel powder, aluminum powder etc. are mentioned. These fillers may be used alone or in combination of two or more. Further, the shape of the filler is not particularly limited, and may be any shape such as a particulate shape, a fiber shape, and a scale shape.

The curing accelerator refers to a substance that does not crosslink itself when the epoxy resin composition is cured, but accelerates the crosslinking reaction. As a hardening accelerator, it does not specifically limit but a well-known hardening accelerator can be used, For example, a triphenylphosphine, imidazole, a tertiary amine, etc. are mentioned. The imidazole is not particularly limited. For example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole. Etc. The tertiary amine is not particularly limited, and for example, benzylmethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (diaminomethyl) phenol, triethylamine, 1,5-diazabicyclo [4, 3,0] -5-Nonene (Trademark: DBA), 1,8-diazabicyclo [5,4,0] -7-undecene (Trademark: DBU), DBU-phenol salt, DBU-octylate , DBU-p-toluenesulfonate and the like. These curing accelerators may be used alone or in combination of two or more.

The organic solvent is not particularly limited. For example, N-methylpyrrolidone; N, N-dimethylformamide; dimethyl sulfoxide; ketones such as methyl ethyl ketone, cyclohexanone, and cyclopentanone; aromatics such as toluene, xylene, and tetramethylbenzene Hydrocarbons; glycol ethers such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; acetic acid Ethyl, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate, esterified products of the above glycol ethers, etc. Esters; alcohols such as ethanol, propanol, methanol, ethylene glycol, propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha Can be mentioned. These organic solvents may be used alone or in combination of two or more.

The hydrophilic coating film is formed from the hydrophilic coating agent of the present invention. A method for forming a hydrophilic coating film using the hydrophilic coating agent of the present invention is not particularly limited, but after applying the hydrophilic coating agent of the present invention to at least one surface of the substrate, it is cured by heating. And the like.

The method for applying the hydrophilic coating agent of the present invention is not particularly limited, for example, bar coating method, spin coating method, spray coating method, dip coating method, nozzle coating method, gravure coating method, reverse roll coating method, Examples include die coating method, air doctor coating method, blade coating method, rod coating method, curtain coating method, knife coating method, transfer roll coating method, squeeze coating method, impregnation coating method, kiss coating method, calendar coating method, extrusion coating method, etc. It is done.

In the method of heating and curing, the heating temperature is not particularly limited, but is preferably 60 to 250 ° C, more preferably 100 to 200 ° C. When the heating temperature is less than 60 ° C., curing may be poor. When the heating temperature exceeds 250 ° C., the shape of the substrate may be impaired depending on the material of the substrate. The heating time is not particularly limited, but is preferably 5 seconds to 5 hours. If the heating time is less than 5 seconds, curing failure may occur. If it exceeds 5 hours, the shape of the substrate may be damaged depending on the material of the substrate, and the time required for the process becomes longer. Therefore, it is not preferable from the viewpoint of productivity.

Although the thickness of a hydrophilic coating film is not specifically limited, It is preferable that it is 0.05-40 micrometers, and it is more preferable that it is 0.1-20 micrometers. When the thickness is less than 0.05 μm, the hydrophilicity may be insufficient, and when it exceeds 40 μm, the adhesion of the hydrophilic coating film may be insufficient.

16-30% is preferable and, as for the water absorption rate of the hydrophilic coating agent obtained from the epoxy resin composition of this invention, 18-25% is more preferable.

The hydrophilic coating agent of the present invention contains the epoxy resin composition. The base material to which the coating agent is applied is not particularly limited, and examples thereof include a base material made of a metal such as glass or aluminum, a plastic or a fiber such as polyester, and a primer layer can be provided as necessary. . The hydrophilic coating agent of the present invention can also be used as a primer layer for paints and coating agents.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to a following example. Hereinafter, “part” or “%” means “part by weight” or “% by weight”, respectively, unless otherwise specified.

(Materials used)
Synthesis example 1 (trimethylolpropane EO addition triglycidyl ether)
Trimethylolpropane EO 20 mol adduct and an excessive amount of epichlorohydrin were mixed and reacted at 60 ° C. using sodium hydroxide. By-product sodium chloride was removed from the obtained resin liquid, and excess epichlorohydrin was concentrated and removed to obtain trimethylolpropane EO-added triglycidyl ether as a target compound in a yield of 92%.

Synthesis example 2 (sorbitol EO addition polyglycidyl ether)
Sorbitol EO22 mol adduct and an excess amount of epichlorohydrin were mixed and reacted at 60 ° C. using sodium hydroxide. By-product sodium chloride was removed from the obtained resin liquid, and excess epichlorohydrin was concentrated and removed to obtain the target compound, sorbitol EO-added polyglycidyl ether, in a yield of 93%.

The materials used in the following examples and comparative examples are shown below.
(A) Epoxy compound polyethylene glycol diglycidyl ether (Nagase ChemteX Corp. Denacol EX-861, k in general formula (1) is 2, l is 20)

(B) Epoxy compound trimethylolpropane EO-added triglycidyl ether (Synthesis Example 1, X in General Formula (2) is a residue obtained by removing a hydroxyl group from trimethylolpropane, p is 2 to 3, q is 0 to 1 and p + q = 3, m is 2, n is 5 to 9. n × p = 20.)
Sorbitol EO-added triglycidyl ether (Synthesis Example 2, X in general formula (2) is a residue obtained by removing a hydroxyl group from sorbitol, p is 4-6, q is 0-2, p + q = 6, m is 2, n is 3 to 5. n × p = 22.)

Glycerol triglycidyl ether (Denacol EX-313, manufactured by Nagase ChemteX Corporation, X in general formula (2) is glycerin, p is 0, q is 3, m, n is 0. n × p = 0.)
Sorbitol polyglycidyl ether (Denacol EX-614B manufactured by Nagase ChemteX Corporation, X in the general formula (2) is sorbitol, p is 0, q is 6, m, and n is 0. n × p = 0.)

(C) Hardener isophoronediamine

Examples 1-6, Comparative Examples 1-5
Each component was mixed in the weight ratio shown in Table 1, and diluted with ion-exchanged water so as to have a solid content of 10% to obtain a hydrophilic coating agent. 3 g of the obtained hydrophilic coating agent was collected in an aluminum container. It put into the 150 degreeC hot-air dryer, and heat-processed for 3 hours, and formed the hydrophilic coating film. What dried the base material to room temperature after drying was used as the test piece. Using the obtained test piece, the physical properties were evaluated by the method described later. The results are shown in Table 1.

(Evaluation method of physical properties)
In each example and comparative example, the physical properties of the test pieces were evaluated by the following methods.
1. Water absorption rate Each test container was allowed to absorb water at 30 ° C. and 90% humidity for 2 hours, and the water absorption rate was measured by comparing the weight of the test container before and after the test. The test was performed 4 times, and the average value is shown in Table 1 as the evaluation result.
2. Residual Residual Ratio Each test container was charged with 3.0 g of purified water, and the supernatant was collected after 30 minutes. Residual rate of the resin was evaluated by measuring the solid content of the supernatant and determining the elution amount of the coating film. The test was performed 4 times, and the average value is shown in Table 1 as the evaluation result.

From the results shown in Table 1, in the epoxy resin composition of the present invention containing the epoxy compound (A) and the epoxy compound (B), as shown in Examples 1 to 6, the resin having a high water absorption rate is high. Has a survival rate. On the other hand, in the composition having only the epoxy compound (A), the resin residual ratio is low as shown in Comparative Example 1, and in the composition having only the epoxy compound (B), water absorption is shown as in Comparative Examples 4 and 5. The rate is lowered.

Claims (6)

(A) the following general formula (1);
_{G-O- (C k H 2k} O) l -G (1)
(G represents a glycidyl group, k is 2 or 3, l is the average number of repetitions and is 1 to 50.)
An epoxy compound represented by
(B) the following general formula (2);
_{(G-O- (C m H} 2m O) n) p -X- (O-G) q (2)
(X is a residue obtained by removing a hydroxyl group from a (p + q) -valent polyhydric alcohol having 3 to 6 carbon atoms, p is 1 to 6, q is 0 to 5, and (p + q) is 3 to 10. And G each independently represents a glycidyl group or a hydrogen atom, m is 2 or 3, and n is the average number of repetitions and is 1 to 50.)
An epoxy compound represented by:
(C) An epoxy resin composition containing a curing agent. The epoxy resin composition according to claim 1, wherein the epoxy compound (B) is an epoxy compound having n × p of 1 to 50 in the general formula (2). The epoxy resin composition according to claim 1 or 2, wherein the epoxy compound (A) is a polyethylene glycol skeleton epoxy compound in which k is 2. The epoxy resin composition according to any one of claims 1 to 3, wherein the epoxy compound (B) is an epoxy compound having a polyethylene glycol chain in which m is 2. The hydrophilic coating agent containing the epoxy resin composition in any one of Claims 1-4. An article coated with the hydrophilic coating agent according to claim 5.