JPH11166107A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition excellent in solubility in a weak solvent such as terpene and mineral spirit and having curing properties, resistance to solvent, flexibility and a high corrosion resistance. SOLUTION: An epoxy resin composition is prepared by internally crosslinking (a) a phenol novolak epoxy resin which has been nuclear substituted with an aliphatic or a cycloaliphatic hydrocarbon group having 4 or more carbon atoms with (b) a prepolymer having at least two isocyanate in its terminal obtained by a reaction of a polyol and an excessive amount of a polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition obtained by subjecting a specific phenol novolak epoxy resin to internal crosslinking with an isocyanate-terminated prepolymer. The present invention relates to an epoxy resin composition that is soluble in a solvent having a low boiling point and is capable of providing a coating film having excellent weather resistance, corrosion resistance, curability, and good adhesion to various substrates.

[0002]

2. Description of the Related Art Epoxy resins have excellent adhesiveness to various substrates, heat resistance, chemical resistance, electrical properties, mechanical properties, and the like.
Widely used as an adhesive and the like.

[0003] When used in these applications, a solvent type in which an epoxy resin is dissolved in various low-boiling solvents has generally been used. However, there is a danger of fire, harm to the human body,
Due to problems such as adverse effects on the global environment, the use of low-boiling solvents has been restricted, and there has been a strong demand for reducing solvents or switching to high-boiling and low-irritating solvents such as terpenes and mineral spirits. became.

However, an epoxy resin or a phenol novolak type epoxy resin which is conventionally produced from bisphenol A or bisphenol F and epichlorohydrin is inferior in solubility in terpenes and mineral spirits. A high boiling and hypoallergenic terpene could not be used. For this reason, it has been strongly desired to find an epoxy resin that is soluble in terpenes and has excellent adhesiveness to various substrates, corrosion resistance, heat resistance, chemical resistance, electrical properties, mechanical properties, and the like.

For example, JP-A-3-115318 discloses a coating in which an epoxy resin having an epoxy equivalent of 250 or less modified with an aliphatic monomer acid is crosslinked with a diisocyanate compound, and the epoxy resin is soluble in mineral spirits. However, in the modified bisphenol A type epoxy resin actually used here, the skeleton of the bisphenol A type epoxy resin itself is still insoluble in a weak solvent such as terpene, so There is a limit in solubility, and when the amount of added solvent increases, there are problems such as cloudiness and separation, and the curability and solvent resistance of the coating film have not been satisfactory.

[0006] Japanese Patent Application Laid-Open No. 9-12678 discloses that
Long-chain alkylphenol novolak resins have been proposed, and their solubility in weak solvents such as terpenes and mineral spirits is satisfactory to some extent.However, ordinary polyamideamine curing agents have a slow curing reaction and require special curing catalysts. Further, the cured coating film is hard and brittle, and has extremely poor solvent resistance, impact resistance, flexibility, and corrosion resistance, and is completely unsuitable especially for paint applications requiring corrosion resistance.

Further, Japanese Patent Application Laid-Open No. Hei 9-227825 proposes an epoxy resin for coatings in which a long-chain alkylphenol novolak resin is reacted with an epoxy resin having an epoxy equivalent of 300 or less, and unreacted epoxy groups are left. Although the solubility in weak solvents such as terpenes and mineral spirits is improved, only those with high epoxy equivalents are obtained and the crosslinking density is low, so the solvent resistance, low-temperature curability and corrosion resistance of the coating film However, it is completely unsuitable for paint applications requiring corrosion resistance.

Japanese Patent Application Laid-Open No. 9-278867 proposes that an epoxy resin obtained by reacting an epoxy resin with a polyisocyanate and a long-chain alkyl novolak phenol resin as a curing agent are used as a laminate material. However, when this is used as a paint, the solubility in a weak solvent such as mineral spirits is reduced, and the resulting coating film has a drawback of poor impact resistance and the like.

Accordingly, an object of the present invention is to provide an epoxy resin composition having excellent solubility in weak solvents such as terpenes and mineral spirits, and exhibiting curability, solvent resistance, flexibility and high corrosion resistance. It is in.

[0010]

Means for Solving the Problems As a result of extensive studies, the present inventors have found that a specific novolak epoxy resin obtained by epoxidizing a long-chain alkylphenol novolak resin or a terpene phenol novolak resin has an isocyanate terminal. It has been found that an epoxy resin composition partially internally crosslinked with a specific prepolymer can achieve the above object.

The present invention has been made based on the above-mentioned findings, and (a) a phenol novolak epoxy resin whose nucleus is substituted by an aliphatic or alicyclic hydrocarbon group having 4 or more carbon atoms, and (b) a polyol And an excess polyisocyanate, and an epoxy resin composition which is internally cross-linked by a prepolymer having at least two isocyanate groups at terminals.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the epoxy resin composition of the present invention will be described in detail.

A phenol novolak epoxy resin whose nucleus is substituted by an aliphatic or alicyclic hydrocarbon group having 4 or more carbon atoms, which is the component (a) used in the present invention (hereinafter referred to as "nuclear-substituted phenol novolak epoxy resin") Is specifically, for example, p-tert-butylphenol, p-tert-amylphenol, hexylphenol,
It is a novolak epoxy resin derived from a nucleus-substituted phenol such as octylphenol, nonylphenol, dodecylphenol, octadecylphenol or terpenephenol, or a mixture thereof.

The component (a) contains a small amount (preferably less than 50% by weight, more preferably less than 30% by weight) of phenol, cresol, ethylphenol, propylphenol and the like in the above-mentioned core-substituted phenol novolak epoxy resin. It may be a mixture.

The nucleus-substituted phenol novolak epoxy resin as the component (a) is obtained, for example, by condensing a nucleus-substituted phenol and a ketone as described above in the presence of a catalyst, and adding epihalohydrin to the obtained phenol novolak resin. Can be easily obtained by reacting
Examples of the ketones used herein include formaldehyde, paraformaldehyde, acetaldehyde, acetone, benzaldehyde and the like, and preferably formaldehyde and paraformaldehyde. Examples of the catalyst that can be used for the reaction between the nuclear-substituted phenols and ketones include formic acid, acetic acid, propionic acid, hydrochloric acid, sulfuric acid, phosphoric acid, salicylic acid, p-toluenesulfonic acid, benzoic acid, and oxalic acid. Acidic catalysts such as dimethylamine, diethylamine, triethylamine, and ammonia; and metal salt catalysts such as sodium hydroxide, potassium hydroxide, lead acetate, and sodium carbonate.

The preferred reaction conditions in the epoxidation step using epihalohydrin are as follows. One equivalent of hydroxyl group of the nucleus-substituted phenol novolak resin is used in an amount of 1.4 to 20 equivalents of epihalohydrin, and 50 to 12 equivalents in the presence of a base.
Reacted at 0 ° C.

Examples of the base used herein include potassium hydroxide, sodium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, potassium carbonate and the like, and particularly preferred is sodium hydroxide or potassium hydroxide. .

In the nucleus-substituted phenol novolak epoxy resin as component (a), the average number of aromatic nuclei is 2
８8, preferably 2-4, with an epoxy equivalent of 2
By using those having a ratio of from 00 to 1000, preferably from 250 to 800, excellent ones such as curability and coating film properties can be obtained.

The terpene phenol is obtained by adding an alkyl phenol compound such as phenol or orthocresol to a cyclic terpene compound. Examples of the terpene phenol include the following formulas (1) to (6) and the like. And the compound represented by

[0020]

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The prepolymer having at least two terminal isocyanate groups as the component (b) used in the present invention is a prepolymer obtained from a polyol and an excess of polyisocyanate.

Examples of the polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-
Propylene glycol, 1,2-butylene glycol,
Low molecular weight polyols such as 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, hydrogenated bisphenol A, bis (hydroxyethoxyphenyl) propane, or ethylene oxide and / or propylene oxide adducts thereof, polyethylene glycol , Polypropylene glycol, polyethylene / propylene glycol, polyether polyols such as polytetramethylene glycol; low molecular weight polyol and / or polyether polyol and succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
Polyester polyol which is a condensate with polybasic acid such as endmethylenetetrahydrophthalic acid, hexahydrophthalic acid or carbonic acid; polyolefin polyol obtained by hydroxylating polyethylene or polypropylene;
Polybutadiene polyol obtained by hydroxylating 1,2-polybutadiene, 1,4-polybutadiene, polyisoprene and the like; polycarbonate polyol and the like.

Further, the polyisocyanate includes
Examples thereof include aliphatic, alicyclic, and aromatic divalent isocyanates. Specific examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, phenylene diisocyanate, and xylylene diisocyanate. , Tetramethylxylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate , 1,5-naphthalenediisocyanate, 1,5-tetrahydronaphthalenediisocyanate, isophorone diisocyanate and the like.

The component (b) has an average molecular weight of 300
By using a prepolymer obtained by adding 1.2 to 2.5 moles, particularly 1.4 to 2.2 moles of diisocyanate to 1 mole of glycol of up to 5000, especially 500 to 3000, terpenes and minerals can be obtained. It is preferable because it has excellent solubility in low boiling point and low irritant solvents such as spirit and excellent physical properties such as flexibility and adhesion.

In the present invention, the novolak epoxy resin as the component (a) should ideally have a structure in which hydroxyl groups on all aromatic rings are substituted with glycidyl ether groups. There are those having a structure in which a group remains as it is or a polyaddition of halohydrin or epihalohydrin, and a considerable amount of alcoholic hydroxyl group remains therein. In the present invention, (a)
The component (b) is an isocyanate group of the isocyanate group-containing prepolymer, which is reacted with the remaining phenolic hydroxyl group and / or the alcoholic hydroxyl group generated by the reaction to cause internal crosslinking. In some cases, an oxazolidone structure can be formed by reacting an isocyanate group with an epoxy group using an oxazolidone-forming catalyst.

The amount of the component (a) used is preferably 70 to 99% in the resin component [component (a) + component (b)].
%, More preferably 75 to 95% by weight. The amount of the component (b) used in the resin component (component (a) + component (b)) is preferably 1 to 30% by weight, more preferably 5 to 25% by weight. If the amount of the component (b) is less than 1% by weight, a sufficient crosslinked structure cannot be formed, sufficient physical properties such as flexibility of the coating film cannot be obtained, and more than 30% by weight. When used, unreacted component (b) or its by-products remain in the epoxy resin composition, which is not preferable because it may reduce various curable properties such as curability and solvent resistance.

The method for producing the epoxy resin composition of the present invention from the components (a) and (b) can be easily carried out by mixing, heating from room temperature to about 100 ° C. and reacting. However, the present invention is not limited to this.

The epoxy resin composition of the present invention has an epoxy equivalent of preferably from 200 to 5,000, particularly preferably from 300 to 2,000. If the epoxy equivalent is less than 200, mechanical properties such as flexibility of the cured film are obtained. Becomes insufficient,
If it exceeds 5,000, the crosslink density decreases and the physical properties such as solvent resistance of the cured product become insufficient.

Other known epoxy resins can be used in combination with the epoxy resin composition of the present invention. Examples of other known epoxy resins include hydroquinone, resorcin, methylresorcin, pyrocatechol, and phloroglucinol. A polyglycidyl ether compound of a mononuclear polyhydric phenol compound; dihydroxynaphthalene;
Biphenol, methylene bisphenol (bisphenol F), methylene bis (orthocresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, 1,3
-Bis (4-hydroxycumylbenzene), 1,4-bis (4-hydroxycumylbenzene), 1,1,3-tris (4-hydroxyphenyl) butane, 1,1,2,2
Polyglycidyl ether compounds of polynuclear polyphenol compounds such as 2-tetra (4-hydroxyphenyl) ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolak, orthocresol novolak, resorcinol novolak, terpene diphenol; ethylene glycol, propylene Polyglycidyl ethers of polyhydric alcohols such as glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-ethylene oxide adduct; maleic acid, fumaric acid, itacone Acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, Tal acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid,
Homopolymers or copolymers of glycidyl esters and glycidyl methacrylates of aliphatic, aromatic or alicyclic polybasic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, endmethylenetetrahydrophthalic acid;
N-diglycidylaniline, bis (4- (N-methyl-
Epoxy compounds having a glycidylamino group such as N-glycidylamino) phenyl) methane; vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-
Epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate,
Epoxy products of cyclic olefin compounds such as bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; epoxidized conjugated diene polymers such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymer; triglycidyl isocyanurate; And a heterocyclic compound of the formula These epoxy resins may be those internally crosslinked by a prepolymer of terminal isocyanate.

The epoxy resin composition of the present invention is generally blended with a curing agent and used for applications such as paints and adhesives.

The curing agent can be used without any particular limitation as long as it is generally used as a curing agent for epoxy resins. For example, aromatic, aliphatic or heterocyclic polyamines can be used. And the like, and polyepoxide addition modified products thereof, amidated modified products, Mannich modified products, and the like can be used as necessary.

Examples of the polyamines include polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine;
1,2-diaminocyclohexane, 1,4-diamino-
Alicyclic polyamines such as 3,6-diethylcyclohexane, isophoronediamine, heterocyclic polyamines such as 1,4-bis (3-aminopropyl) piperazine, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc. Aromatic polyamines. In addition, the polyepoxide-added modified products include these polyamines and glycidyl ethers such as phenyl glycidyl ether, butyl glycidyl ether, bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, and glycidyl esters of carboxylic acid. Manufactured by reacting various epoxy resins by a conventional method, the amidated modified product is obtained by reacting these polyamines with carboxylic acids such as phthalic acid, isophthalic acid, and dimer acid by a conventional method. The above-mentioned Mannich modified product is produced by combining these polyamines with aldehydes such as formaldehyde and at least one aldehyde on the nucleus such as phenol, cresol, xylenol, tert-butylphenol, and resorcinol. A phenol having a refractory location is produced by reacting in a conventional manner. Among these curing agents, the use of a polyamidoamine compound obtained from a polyamine and a dibasic acid salt is preferable because a coating film having particularly excellent anticorrosion properties can be formed.

The amount of the curing agent used varies depending on conditions such as the purpose, curing temperature and curing time, but is usually from 1 to 100 parts by weight of the resin component (component (a) + component (b)). It is 50 parts by weight, preferably 5 to 20 parts by weight. If the amount of the curing agent is less than 1 part by weight, the curing is insufficient and the adhesion and anticorrosion properties are inferior. If the amount is more than 50 parts by weight, unreacted amine remains and the solvent resistance decreases. In addition, because of the polarity of the amine, dilution of the solvent such as terpen becomes difficult, which may cause a problem in workability in the coating process, which is not preferable.

When the epoxy resin composition of the present invention is used as a paint, a solvent is usually blended, and examples of the solvent include acetone, toluene, xylene, methyl ethyl ketone, ethyl acetate, propylene glycol monoethyl ether. Solvents such as ter, N, N-dimethylformamide, N, N-dimethylacetamide, and ethyl acetate can be used. However, the epoxy resin composition of the present invention uses terpene-based carbonization such as turpentine oil, D-limonene, and pinene. Hydrogen oil; mineral spirit, swazole #
310 (Cosmo Matsuyama Oil Co., Ltd.), Solvesso # 100
(Exxon Chemical Co., Ltd.) or other high-boiling paraffinic solvents (which may contain alicyclic or aromatic hydrocarbons mainly containing aliphatic hydrocarbons. Here, the high boiling point means a boiling point of 150 ° C.)
This indicates that the composition contains 90% or more of the above components. ) Is soluble in
It is preferable because danger and harmfulness can be further reduced. Further, these solvents can be optionally used as a mixed solvent of two or more kinds.

The amount of the solvent used varies depending on the purpose, but is usually a resin component [component (a) + component (b)].
0 to 1000 parts by weight, preferably 10 to 600 parts by weight, per 100 parts by weight.

Further, the epoxy resin composition of the present invention comprises:
Solubility in solvents such as terpenes by using as a reactive diluent a phenol monoglycidyl ether compound whose nucleus is substituted by an aliphatic or alicyclic hydrocarbon group having 4 or more carbon atoms having a similar skeleton to the main agent. And the effect of improving physical properties such as impact resistance can be obtained. As these monoglycidyl ether compounds,
For example, phenol, cresol, ethylphenol,
Propylphenol, p-tert-butylphenol, p-
Tertiary amylphenol, hexylphenol, octylphenol, nonylphenol, dodecylphenol,
Monoglycidyl ethers such as octadecyl phenol and terpene phenol are exemplified.

The amount of the monoglycidyl ether compound used is preferably 0 to 50 parts by weight, more preferably 3 to 20 parts by weight, based on 100 parts by weight of the resin component ((a) component + (b) component). If it is used in an amount exceeding 50 parts by weight, the curability may be reduced or various physical properties may be adversely affected, which is not preferable.

Further, the epoxy resin composition of the present invention comprises:
As a matter of course, other reactive diluents; non-reactive diluents (plasticizers) such as dioctyl phthalate, dibutyl phthalate, benzyl alcohol and coal tar can also be used in combination.

Further, the epoxy resin composition of the present invention includes:
If necessary, fillers or pigments such as glass fiber, carbon fiber, cellulose, silica sand, cement, kaolin, clay, aluminum hydroxide, bentonite, silica, finely divided silica, titanium dioxide, carbon black, graphite, iron oxide, etc. A thickening agent; a thixotropic agent; a flame retardant; an antifoaming agent; which may contain conventional additives such as colloidal silica and colloidal alumina, and furthermore, adhesiveness such as xylene resin, petroleum resin, rosin and terpene resin. Can be used in combination.

The preferred compounding composition of the epoxy resin composition of the present invention is the above-mentioned resin component [component (a) + component (b)].
0 parts by weight of the monoglycidyl ether compound 0 to
The composition is a combination of 50 parts by weight and 0 to 1000 parts by weight of the high boiling point paraffin solvent or the terpene hydrocarbon oil. Further, a more preferable composition of the epoxy resin composition of the present invention is the above-mentioned resin component [(a) component +
(B) Component] A composition comprising 100 parts by weight of 3 to 20 parts by weight of the monoglycidyl ether compound and 10 to 600 parts by weight of the high-boiling paraffin solvent or terpene hydrocarbon oil. Further, the epoxy resin composition of the present invention having such a composition preferably uses 1 to 50 parts by weight, particularly 5 to 20 parts by weight, of a polyamide as a curing agent.

The epoxy resin composition of the present invention is, for example,
Paint or adhesive for concrete, cement mortar, various metals, leather, glass, rubber, plastic, wood, cloth, paper, etc .; adhesive tape for packaging, adhesive label, frozen food label, ream bubble label, POS label, adhesive wallpaper, Adhesive for adhesive flooring; Art paper, coated paper, lightweight coated paper, cast coated paper, coated paperboard, carbonless copier, impregnated paper and other processed paper; natural fibers, synthetic fibers, glass fibers, carbon fibers, metals Sizing agent for fibers, anti-fraying agent,
It can be used in a wide range of applications such as fiber treatment agents such as processing agents; building materials such as sealing materials, cement admixtures, and waterproofing materials.

[0042]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples.

Production Example 1 (Production of Novolac Epoxy Resin) In a 2 L reactor equipped with a thermometer, a stirrer and a water separator equipped with a cooling pipe, a titanol # 1133 (manufactured by Hitachi Chemical Co., Ltd .; p- 250 g of tributylphenol novolak resin, OH equivalent 158, average number of nuclei 3) 250 g, hitanol # 1501 (manufactured by Hitachi Chemical Co., Ltd .; octylphenol novolak resin, OH equivalent 214, average number of nuclei 3) 250 g, and epichlorohydrin 1440 g were charged. After stirring to form a homogeneous solution, 268 g of 48% by weight sodium hydroxide was added dropwise at 60 to 110 ° C over 2 hours. During this time, epichlorohydrin was refluxed in the system while water generated in the system was azeotropically removed with epichlorohydrin and removed outside the system by a water separator. After dropping, 100
The mixture was aged at -120 ° C for 2 hours, and the reaction was terminated when the theoretical amount of water flowed out.

Xylene (150 g) was added to the obtained epichlorohydrin solution of the epoxy compound, washed with a large amount of water to remove generated salt and excess sodium hydroxide, and neutralized with a 3% by weight aqueous phosphoric acid solution. Then, epichlorohydrin and xylene were distilled off under reduced pressure to obtain an epoxy resin having an epoxy equivalent of 340. To this, 460 g of Swazole # 310 (manufactured by Cosmo Matsuyama Co., Ltd .; a high-boiling paraffin solvent) was added, and a brown liquid epoxy resin (N
EP-1) 1150 g were obtained. The chlorine content is 0.1.
The epoxy equivalent was 3% by weight, the epoxy equivalent was 570, and the solid content was 60% by weight.

Production Example 2 (Production of novolak epoxy resin) In a 2 L reactor equipped with a thermometer, a stirrer and a water separator equipped with a condenser, 250 g of terpene phenol novolak resin (prototype, OH equivalent 340), titanium # 1
501 250 g and epichlorohydrin 1440 g
Was charged and stirred to form a homogeneous solution, and 268 g of 48% by weight sodium hydroxide was added dropwise at 60 to 110 ° C over 2 hours. During this time, epichlorohydrin was refluxed in the system while water generated in the system was azeotropically removed with epichlorohydrin and removed outside the system by a water separator. After dropping, 1
After aging at 00 to 120 ° C for 2 hours, the reaction was terminated when the theoretical amount of water had flowed out.

600 g of xylene was added to the obtained epichlorohydrin solution of the epoxy compound, washed with a large amount of water to remove generated salt and excess sodium hydroxide, and then neutralized with a 3% by weight phosphoric acid aqueous solution. Next, epichlorohydrin and xylene were distilled off under reduced pressure to obtain an epoxy resin having an epoxy equivalent of 440. To this, 480 g of Swazole # 310 was added to obtain 1050 g of a brown liquid epoxy resin (NEP-2). This saponifiable chlorine was 0.4% by weight, the epoxy equivalent was 740, and the solid content was 60% by weight.

Production Example 3 (Production of Prepolymer) In a 1 L reactor equipped with a thermometer, a stirrer, and a cooling tube,
Adeka polyether P-700 (manufactured by Asahi Denka Kogyo KK);
Polypropylene glycol, hydroxyl value 155) 362
g, Coronate T-80 (manufactured by Nippon Polyurethane Co .; tolylene diisocyanate), and reacted at 80 to 90 ° C. for 3 hours while paying attention to a temperature rise, and a colorless transparent liquid prepolymer (PP-1, isocyanate content) 7.8% by weight).

Production Example 4 (Production of Prepolymer) In a 1 L reactor equipped with a thermometer, a stirrer, and a cooling tube,
422 g of PTG-850 (manufactured by Hodogaya Chemical Co., Ltd .; polytetramethylene glycol, hydroxyl value 133) and 174 g of Coronate T-80 were charged, and reacted at 80 to 90 ° C. for 3 hours while paying attention to a rise in temperature. A prepolymer (PP-2, isocyanate content 7.0% by weight) was obtained.

Production Example 5 (Production of Prepolymer) In a 1 L reactor equipped with a thermometer, a stirrer, and a cooling tube,
Nisso polybutadiene G-1000 (manufactured by Nippon Soda Co .;
Polybutadiene glycol, hydroxyl value 68) 825 g,
223 g of isophorone diisocyanate was charged and reacted at 80 to 90 ° C. for 3 hours while paying attention to temperature rise, to obtain a colorless and transparent liquid prepolymer (PP-3, isocyanate content: 4.0% by weight).

Production Example 6 (Preparation of Prepolymer) A 1 L reactor equipped with a thermometer, a stirrer, and a condenser was charged with
Adeka polyether P-400 (manufactured by Asahi Denka Kogyo Co., Ltd.)
Polypropylene glycol, hydroxyl value 211) 265
g and 131 g of Coronate T-80, and reacted at 80 to 90 ° C. for 3 hours while paying attention to temperature rise, to obtain a colorless and transparent liquid prepolymer (PP-4, isocyanate content 5.3% by weight).

Production Example 7 (Production of Terpene Monoepoxy Diluent) YP-90LL (manufactured by Yashara Chemical Co., Ltd .; terpene monophenol) was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a condenser. , Average molecular weight 28
0, OH equivalent 330) 495 g and epichlorohydrin 788 g were charged and stirred to obtain a homogeneous solution.
131.3 g of a weight% aqueous sodium hydroxide solution is
It was added dropwise at 10 ° C. over 2 hours. During this time, epichlorohydrin was refluxed in the system while water generated in the system was azeotropically removed with epichlorohydrin and removed outside the system by a water separator. After dropping, aging at 100-120 ° C for 2 hours,
The reaction was terminated when the theoretical amount of water had flowed out.

800 g of xylene was added to the obtained epichlorohydrin solution of the epoxy compound, washed with a large amount of water to remove generated salt and excess sodium hydroxide, and then neutralized with a 3% by weight phosphoric acid aqueous solution. Next, epichlorohydrin and xylene were distilled off under reduced pressure to obtain 400 g of a brown liquid epoxy resin diluent (K-1). This saponifiable chlorine is 0.3% and the epoxy equivalent is 43%.
It was 0.

Example 1 Epoxy resin (NEP-1) 118 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
0 g, keeping the inside of the system at 80 to 90 ° C., and paying attention to the temperature rise, and 126.4 g of the prepolymer (PP-1).
(15% by weight of solid content) was added dropwise over 30 minutes.
For 2 hours, and the temperature was further raised to 100 ° C. to react for 1 hour. Finally, 85 g of Swazole # 310 was added, and an epoxy resin composition (EP-1, solid content 60% by weight,
Epoxy equivalent 750) was obtained.

Example 2 Epoxy resin (NEP-1) 117 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
8 g and diluent (K-1) 50 g were charged.
126.4 g of prepolymer (PP-1) (15% by weight of solids) while keeping the temperature at 0 to 90 ° C. and paying attention to temperature rise.
Was added dropwise over 30 minutes, aged at 90 ° C. for 2 hours, further heated to 100 ° C., and reacted for 1 hour. Finally, 118 g of Swazol # 310 was added to add an epoxy resin composition (EP-2, solid content 60% by weight, epoxy equivalent 750).
I got

Example 3 Epoxy resin (NEP-2) 118 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
0 g, keeping the inside of the system at 80 to 90 ° C., and paying attention to the temperature rise, and 126.4 g of the prepolymer (PP-1).
(15% by weight of solid content) was added dropwise over 30 minutes.
For 2 hours, and the temperature was further raised to 100 ° C. to react for 1 hour. Finally, 85 g of Swazole # 310 was added, and an epoxy resin composition (EP-3, solid content 60% by weight,
Epoxy equivalent 950) was obtained.

Example 4 Epoxy resin (NEP-1) 118 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
0 g, keeping the inside of the system at 80 to 90 ° C., and paying attention to the temperature rise, and 126.4 g of the prepolymer (PP-2).
(15% by weight of solid content) was added dropwise over 30 minutes.
For 2 hours, and the temperature was further raised to 100 ° C. to react for 1 hour. Finally, 85 g of Swazole # 310 was added, and the epoxy resin composition (EP-4, solid content 60% by weight,
An epoxy equivalent of 800) was obtained.

Example 5 Epoxy resin (NEP-1) 118 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
0 g, keeping the inside of the system at 80 to 90 ° C., and paying attention to the temperature rise, and 126.4 g of the prepolymer (PP-3).
(15% by weight of solid content) was added dropwise over 30 minutes.
For 2 hours, and the temperature was further raised to 100 ° C. to react for 1 hour. Finally, 85 g of Swazole # 310 was added, and an epoxy resin composition (EP-5, solid content 60% by weight,
Epoxy equivalent 750) was obtained.

Example 6 Epoxy resin (NEP-1) 117 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
8 g and diluent (K-1) 50 g were charged.
While maintaining the temperature at 0 to 90 ° C. and paying attention to the temperature rise, 126.4 g of the prepolymer (PP-4) was added dropwise over 30 minutes,
Aged at 90 ° C for 2 hours, heated to 100 ° C and
Allowed to react for hours. Finally, Swazole # 310 118g
To the epoxy resin composition (EP-6, solid content 60
Wt%, epoxy equivalent 750).

Example 7 Epoxy resin (NEP-1) 118 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
Of the prepolymer (PP-1) 84.3 g while keeping the system at 80 to 90 ° C.
(10% by weight of solid content) was added dropwise over 30 minutes,
For 2 hours, and the temperature was further raised to 100 ° C. to react for 1 hour. Finally, 56 g of swazole # 310 was added and the epoxy resin composition (EP-7, solid content 60% by weight,
Epoxy equivalent 750) was obtained.

Comparative Example 1 Epoxy resin (NEP-1) was used as it was.

Comparative Example 2 An epoxy resin (NEP-2) was used as it was.

Comparative Example 3 An epoxy resin composition (HEP-1, solid content 62% by weight, epoxy equivalent 730) was obtained by adding 5% by weight of diluent (K-1) to epoxy resin (NEP-2) and mixing. Was.

Comparative Example 4 Epoxy resin (NEP-1) 117 was placed in a 2 L reactor equipped with a thermometer, a stirrer, and a water separator equipped with a cooling pipe.
8 g, keeping the inside of the system at 80 to 90 ° C., and paying attention to the temperature rise, 63.2 g of isophorone diisocyanate
(7.5% by weight of solid content) was added dropwise over 30 minutes, and 90
The mixture was aged at 2 ° C. for 2 hours, heated to 100 ° C., and reacted for 1 hour. Finally, 45 g of Swazole # 310 was added to obtain an epoxy resin composition (HEP-2, solid content 60% by weight, epoxy equivalent 700).

100 g of each of the epoxy resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 4 was dissolved in 100 g of mineral spirit, and the solubility was checked. Evaluation is next 3
Performed in stages. The results are shown in Table 1 below. ：: Uniformly dissolved, no insoluble matter was observed. Δ: A small amount of insoluble matter is observed. X: A large amount of insoluble matter is observed.

Further, the above Examples 1 to 7 and Comparative Examples 1 to 4
Using the epoxy resin composition obtained in the above, the mixture was kneaded with a ball mill for 6 hours according to the following composition to prepare a white paint.

(Blending) Epoxy resin composition 100 parts by weight Titanium dioxide 60 Talc 120 Bentonite 1 Mineral spirit 200

The obtained white paint was coated with Granmide 640 (manufactured by Asahi Denka Kogyo Co., Ltd .; modified polyamidoamine, active hydrogen equivalent: 95) as a curing agent, and epoxy group of epoxy resin / curing agent active hydrogen = 1/1 equivalent ratio. To give a coating composition.

Next, the coating composition obtained was applied on a mild steel plate (SPCC-B) using an applicator so as to have a thickness of 70 μm, and the following characteristics were evaluated. In addition, and used the coated steel plate which was allowed to stand at 25 ° C. for 7 days and dried and hardened. The results are shown in Table 2 below.

The method of each performance evaluation is as follows. Erichsen; using an Erichsen tester, φ20 mm,
The test was performed under the condition of 8 mm. Impact resistance test: 500 g using a DuPont impact tester
The crack state of the coating film was evaluated under the conditions of × 50 cm and φ8 mm. The criteria are as follows. ；: No cracks or cracks are observed △; 〃 some are seen. ×; 〃 Many are seen. Solvent resistance: After the coating film was applied, it was allowed to stand at room temperature for 150 hours, and then one drop of toluene was dropped on the coating film, and a rubbing test was performed with absorbent cotton to confirm the number of times until the base material appeared. Low-temperature curability: The presence or absence of tacking when left at 10 ° C. for 15 hours after application of the coating film was evaluated by finger touch and evaluated in two stages of ○ ×. Corrosion resistance test: A coating film test piece was subjected to SST for 500 hours based on JIS K-5400. The criteria are as follows. Flat part ○; No rust and blistering △; 〃 Slightly seen ×; ら れ る Cross cut part ○: Smeared and blistered 0.5 mm or less ○ ~ △; ０．５ 0.5-2 mm ×; 〃 2 mm or more

[0070]

[Table 1]

As is clear from the above Examples and Comparative Examples, the epoxy resin composition of the present invention obtained by partially internally crosslinking a specific nucleated phenol novolak epoxy resin with a specific isocyanate-terminated prepolymer (Examples) 1
7) are excellent in solubility in mineral spirit which is a weak solvent, show good curability, and can form a coating film having excellent physical properties.

On the other hand, the epoxy resin compositions which were not subjected to internal crosslinking (Comparative Examples 1 to 3) had the effect of dissolving in mineral spirits, but hardened slowly, and the resulting coating films had impact resistance. It is completely inadequate in terms of properties, solvent resistance, corrosion resistance and the like. The epoxy resin composition (Comparative Example 4) obtained by simply reacting with the polyisocyanate instead of the above-mentioned prepolymer according to the present invention can obtain the effect of corrosion resistance of the obtained coating film, but has a slow curing. Also, the solubility in mineral spirit is slightly inferior, and the resulting coating film is quite insufficient in impact resistance and solvent resistance.

[0073]

The epoxy resin composition of the present invention is soluble in a highly safe solvent having a high boiling point and low irritation, and is excellent in curability, corrosion resistance, solvent resistance, etc., and is suitable for various paints and adhesives. It is useful for applications such as sealing materials.

Claims (6)

[Claims] 1. A phenol novolak epoxy resin obtained by (a) nucleus-substituted aliphatic or alicyclic hydrocarbon group having 4 or more carbon atoms, and (b) a terminal obtained from a polyol and an excess of polyisocyanate. At least 2
An epoxy resin composition internally crosslinked by a prepolymer having two isocyanate groups. 2. A resin component [component (a) + component (b)]
2. The epoxy resin composition according to claim 1, wherein component (b) is used in an amount of 5 to 25% by weight. 3. The composition according to claim 1, wherein the component (b) has an average molecular weight of 300 to 300.
3. The epoxy resin composition according to claim 1, which is a prepolymer obtained by adding 1.2 to 2.5 mol of diisocyanate to 1 mol of 5000 glycol. 4. A resin component [component (a) + component (b)] 1.
At least one kind of a phenol monoglycidyl ether compound obtained by nucleus substitution with an aliphatic or alicyclic hydrocarbon group having 4 or more carbon atoms per 100 parts by weight.
The epoxy resin composition according to any one of claims 1 to 3, wherein the epoxy resin composition is used in parts by weight. 5. A resin component [component (a) + component (b)] 1.
The epoxy resin composition according to any one of claims 1 to 4, wherein 10 to 600 parts by weight of at least one kind of a high boiling point paraffin solvent or a terpene hydrocarbon oil is used in combination with 00 parts by weight. 6. A resin component [component (a) + component (b)] 1.
The epoxy resin composition according to any one of claims 1 to 5, wherein 1 to 50 parts by weight of polyamidoamine is used as a curing agent with respect to 00 parts by weight.