KR930004371B1 - Polyol resin and paint composition comprising same - Google Patents

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Description

Polyol resin and paint composition using same

The present invention relates to a polyol resin and a coating composition using the same, and more particularly, to an improvement of a polyol compound composed of a reaction product of a bisphenol-type epoxy resin and an active hydrogen-containing compound reactive with an epoxy group.

So-called bisphenol type epoxy resins made of bisphenol and epichlorohydrin (ECH) or β-methyl epichlorohydrin are used in various applications for curing by utilizing the reactivity of epoxy groups. On the other hand, modified epoxy resins obtained by open-reacting epoxy groups with active hydrogen compounds improve the adhesion and corrosion resistance of paints such as epoxy resins, melamine resins, phenol resins, alkyd resins, urethane resins and the like by utilizing the reactivity of hydroxyl groups in the resins. It is used for the purpose.

In this case, the coating properties of the final coating is greatly affected by the chemical structure and properties of the modified epoxy resin. For example, in the field of urethane paint, bubbles are generated in the coating film as a result of the reaction of isocyanate, which is a curing agent, with moisture contained in a modified epoxy resin, which is a coating resin component, and the bubbles generated at this time adversely affect the coating performance such as corrosion resistance.

In order to suppress such bubbles, it is known that a high molecular weight is used as the raw material resin or an active hydrogen compound having a primary hydroxyl group rich in reactivity with isocyanate groups can be used as a modifier, and a highly reactive hydroxyl group can be introduced into the resin. . However, this modified resin has a new problem that the compatibility with aromatic compounds such as toluene and xylene, which are usually used as paint solvents, is significantly lowered.

Accordingly, the present invention relates to an improvement of a polyol resin obtained by the reaction of a bisphenol-type epoxy resin with an active hydrogen-containing compound which is reactive with an epoxy group, and has excellent high solubility in aromatic solvents and the like with sufficient high molecular weight and hydroxyl group concentration. It aims at providing the polyol resin shown.

Another object of the present invention is to provide a polyol resin having a low foaming property when combined with a polyisocyanate crosslinking agent, excellent in solubility in a solvent, and giving excellent coating properties when used in a urethane paint and a urethane paint using the same.

According to the present invention, (a) a bisphenol type epoxy resin containing at least a part of an alkyl-substituted phenol component of the following formula (I);

R 'is an alkyl group having at least 4 carbon atoms, preferably at least 6, particularly preferably 6-20, n is a number of 1 or 2), (b) reaction with an active hydrogen-containing compound reactive to an epoxy group A polyol resin composed of the product and substantially free of epoxy groups is provided.

According to the present invention, there is provided a urethane paint comprising an organic solvent comprising (A) the polyol resin, (B) polyisocyanate or block polyisocyanate, and (C) aromatic hydrocarbon.

The present invention relates to bisphenol-type epoxy resins containing bisphenols having a long-chain alkyl group, i.e., C ₆ or more, especially C ₈ or more alkyl group, in the aromatic nucleus, and an active hydrogen-containing organic compound having a reactivity to the epoxy group. It consists of reaction products obtained by reacting with alkanol amines or phenols to produce polyol resins with almost no epoxy groups. These resins are easily dissolved in organic solvents such as aromatic solvents despite having high molecular weight and hydroxyl concentration. It is based on.

Moreover, this invention is based on the point that when this polyol resin is used as a resin component of a urethane coating material, foaming tendency is small, favorable curability or crosslinking property can be obtained, and the outstanding coating film performance can be obtained.

[Bisphenol-type epoxy resin]

The bisphenol type epoxy resin used for this invention is manufactured by using a long-chain alkyl-substituted bisphenol component of said Formula (I) as at least one part of bisphenols by a well-known manufacturing method. Examples of the long-chain alkyl group R 'in the formula (I) include an octyl group, nonyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group, and the like. When the alkyl group R' is smaller than 6 carbon atoms, the final polyol There exists a tendency for the solubility of resin to aromatic organic solvent to fall, and a polyol resin tends to contain water.

In the present invention, the bisphenol-type epoxy resin may be composed of all of the bisphenol components composed of long-chain alkyl-substituted bisphenols, some of the bisphenol components may be composed of long-chain alkyl-substituted bisphenols, and others may be composed of other bisphenols. Examples of the other bisphenols include bisphenols without substituent R 'in General Formula (I), for example, conventional bisphenol A, bisphenol B, bisphenol F and the like. The ratio of the long-chain alkyl-substituted bisphenol component to the total bisphenol component in the epoxy resin is preferably 20 mol% or more, particularly 30 mol% or more from the viewpoint of solubility and hygroscopicity.

As a method of obtaining a bisphenol-type epoxy resin from the above-mentioned bisphenols, the following is mentioned.

[Reaction Example 1]

Said bisphenols and epichlorohydrin or (beta) -methyl epichlorohydrin are made to react. In this case, the molecular weight of the epoxy resin obtained can be adjusted by suitably selecting the apparatus ratio of bisphenol and epichlorohydrin. Generally, the higher the ratio of epichlorohydrin / bisphenols, the lower the molecular weight.

In addition, the epoxy resin obtained in this way and bisphenols can be subjected to heavy addition reaction to achieve high molecular weight.

[Reaction Example 2]

The polyaddition reaction of the epoxy resin obtained by the said reaction example 1, and another bivalent phenols is carried out.

[Reaction Example 3]

The heavy addition of the above-mentioned bisphenols and conventionally known epoxy resins is carried out. The bisphenol-type epoxy resin used for this invention is generally represented by Formula (II).

(Wherein, X is a hydrogen atom or an ethyl group, m is an epoxy equivalent is an integer of 0-15, Z is the following formula (III) or the following formula (IV) or a combination thereof).

Wherein R is -CH _2- , -CHCH _3- , -C (CH ₃ ) _2- ,

(R 'is an alkyl group of 4 or more, preferably 6 or more, more preferably 8 or more, and n is an integer of 1 or 2).

In addition, long-chain alkyl-substituted bisphenyls are obtained by the reaction of a phenol derivative represented by formula (V) with aldehydes such as formaldehyde, acetaldehyde, acetone, acetphenone, cyclohexanone, and benzophenone, or ketones. .

[Polyol Resin]

Examples of the active hydrogen-containing compound (b) reacted with the bisphenol type epoxy resin obtained as described above include diethanolamine, diisopropanolamine, bis (2-hydroxybutyl) amine, bis (2-hydroxyoctyl) amine, N Alkanolamines having 2 to 20 carbon atoms, such as methylethanolamine, N-methylisopropanolamine, N-ethylethanolamine, and N-benzylethanolamine or phenol, cresol, isopropylphenol, isobutylphenol, nonylphenol and xylene Phenols having 6 to 30 carbon atoms such as phenol and di-S-butylphenol, especially alkylphenols or secondary amines having 4 to 20 carbon atoms such as diethylamine, dibutylamine and N-methylaniline, acetic acid, stearic acid and unde C1-C30 monocarboxylic acids, such as a styrene acid, benzoic acid, toluic acid, methanol, a propanol, butanol, an octanol, ethylene glycol, propylene glycol, 4-butanediol, 1, 3- hexanediol, etc. Alcohols;

In the use ratio of these (a) component and (b) component, the active hydrogen of (b) component with respect to the epoxy group in (a) component is 0.95-1.05 in equivalence ratio, Preferably it is 0.98-1.00. If necessary, this reaction, in particular bisphenols and / or primary amines, may be coexisted, and this reaction may be carried out while extending the chain.

This reaction is generally carried out at a temperature of about 50-250 ° C., preferably about 100-200 ° C., in the presence of a catalyst and a solvent or in the absence of a solvent. If the reaction temperature is lower than this, the reaction rate is slow. On the other hand, if the reaction temperature is higher than this, the reaction between the epoxy group and the hydroxyl group or the open ring reaction between the epoxy groups occurs in the step of forming the epoxy resin modified product, resulting in gelation of the reactant. There is a risk of occurrence.

Examples of the catalyst include alkali metal hydroxides such as sodium hydroxide and lithium hydroxide, alkali metal alcoholates such as sodium methylate, tertiary amines such as dimethylbenzylamine, triethylamine and pyridine, tetramethyl ammonium chloride and benzyltrimethylammonium. Quaternary ammonium salts such as chloride, organophosphorous compounds such as triphenylphosphine and triethylphosphine, quaternary phosphonium salts such as triphenylphosphine and methyl iodide adduct, alkali metal salts such as sodium carbonate and lithium chloride, and trifluorine Lewis acids such as boron fluoride, aluminum trichloride and tin tetrachloride, and complexes such as boron trifluoride and diethyl ether adducts are generally about 0.01-10000 ppm with respect to component (a), preferably about 0.1- 1000 ppm is used. In addition, alkanol amines in (b) component are used as a catalyst itself. In this case, first, a catalytic amount of alkanolamines may be used to react with another active hydrogen-containing compound, followed by addition of the remaining alkanolamine to the reaction.

When a solvent is used, those which do not have active hydrogen, such as hydrocarbons such as toluene and xylene, ketones such as methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, can be used.

The polyol resin obtained according to the present invention does not substantially contain an epoxy group by reaction with the active hydrogen-containing compound, and the hydroxyl value is generally about 50 to 1000 mg-KOH / g. The number average molecular weight also varies depending on the degree of chain length, but is generally in the range of about 500 to about 6000.

[Usage]

The polyol resin thus obtained is calcined by a combination of resins having methylol groups such as amino resins and resols, including melamine resins and urea resins, and at room temperature by a combination of isocyanates and block isocyanates. It can be used as dry paint or calcined paint.

The polyol resin of the present invention is particularly useful as a resin component of urethane paint. In this case, as polyisocyanate, tolylene diisocyanate, 3,3'- bititolylene-4,4'- diisocyanate, diphenylmethane-4,4'- diisocyanate, metaphenylene diisocyanate, naphthaline diisocyanate, hexamethylene di Isocyanate etc. are used individually or in combination of 2 or more types. Furthermore, block isocyanates masked (blocked) with phenols, maronic acid esters, acetic acid esters, acetylacetone, or the like may be used for the one-component coating.

Other polyol resins such as polyester polyols and acrylic polyols, polyethers such as polyethylene glycol and polypropylene glycol, polyester resins, acrylic resins, fibrin resins and the like can also be used as these modifiers.

In addition, when used in various applications, various white tars including talc, calcium carbonate, silica, carbon, petroleum resin, various vinyl copolymers, inorganic or organic fillers such as tar, asphalt, pigments, etc. may be used if necessary. It may be.

The polyol resin of the present invention has the following effects.

(A) Compatibility with an aromatic compound solvent improves.

(B) Foaming at the time of curing can be effectively prevented, and coating film formation is excellent.

(C) oligomers containing ethylene resins such as petroleum resins, styrene, α-methylstyrene, and hydrocarbon-based monomers such as xylene resins, which have lacked compatibility with conventional polyol resins based on epoxy resins; The compatibility of coating organic fillers such as ketone resins and macro resins, and so-called white tars, is also improved.

(D) When the polyol resin according to the present invention is applied to a coating, a film having excellent corrosion resistance, chemical resistance, adhesion to gas, abrasion resistance, plasticity, and the like is formed.

(ㅁ) When a relatively low molecular weight epoxy resin is used as a raw material for urethane paints, fewer bubbles are generated, which makes it possible to reduce the viscosity of the solvent type paint and to make high sounding.

Example 1

[Synthesis of bis (nonylhydroxyphenyl) methane]

1542 g of nonylphenol, 65.8 g of 40% aqueous formaldehyde solution and 1.54 ml of concentrated hydrochloric acid were added to a 3 l round bottom flask equipped with a stirring apparatus, a thermometer, and a cooling tube, and the reaction was carried out at reflux for 5 hours. Next, the reaction solution was distilled under conditions of 3 torr and 140 ° C to distill water, unreacted formaldehyde and nonylphenol. The remainder was further molecularly distilled at 50 m torr and 125 ° C. to separate nonylphenol to obtain bis (hydroxynonylphenol) methane (hereinafter referred to as bis (nonylphenol) F).

This bis (nonylphenol) F contained 85% or more of those having a nonyl group in the P-position.

[Synthesis of epoxy resin]

199 g of bis (nonylphenol) F obtained by the above operation was dissolved and dissolved in 326 g of epichlorohydrin (hereinafter abbreviated as ECH), and the temperature of the reaction system was raised to 70 ° C. 48% NaOH aqueous-solution was added to this at 3 parts of the start of reaction at 70 degreeC, 0.5 hour after the start of reaction, and 1.0 hour after the start of reaction. NaOH used at one time was 0.36 mol with respect to 1 mol of bis (nonylphenol) F. After the third addition of aqueous NaOH solution, the mixture was stirred again at 70 ° C. for 30 minutes.

After adjusting the pressure in the reaction system in the range of 150mmHg to 250mmHg, 66.7g of 48% NaOH aqueous solution was continuously added at 70 ° C. over 2 hours, and the water produced by the reaction therebetween and water from NaOH aqueous solution were It separated by reflux of the -ECH azeotrope mixture, and it removed continuously out of the reaction system. At this time, the outflowing ECH was returned to the reaction system. After the aqueous NaOH solution was added, the mixture was stirred again at 70 ° C. for 30 minutes. The remaining ECH was distilled off and the product was heated again to 125 ° C / 10 mmHg for 30 minutes.

148 g of water and 249 g of methyl isobutyl ketone were added to the mixture of the resulting resin and sodium chloride, followed by stirring for 30 minutes at a temperature of about 90 ° C.

After standing still, the lower sodium chloride aqueous solution was separated and removed. The methyl isobutyl ketone solution layer of resin was neutralized with phosphoric acid, and the aqueous layer was separated. After azeotropically dehydrating water contained in the solution of methyl isobutyl ketone resin, the precipitated salt was removed by G-4 glass filter. Finally, methyl isobutyl ketone was removed in vacuo, and the resulting resin was heated at 150 ° C./5 mmHg again for 30 minutes to obtain a liquid epoxy resin.

The epoxy unit amount of this liquid epoxy resin was 365 g / equivalent.

[Synthesis of Polyol Resin]

726 g of epoxy resin and 317 g of bis (nonylphenol) F obtained by the above operation were added to a _two -liter detachable flask equipped with a stirring device, a thermometer, and a cooling tube, and the system was replaced with N ₂ gas. Subsequently, the system was heated up by an oilbus, 0.16 g of N, N-dimethyl benzylamine was added, and the reaction was carried out under stirring until the epoxy equivalent was 1750 at 170 캜.

Subsequently, the reaction was carried out while slowly adding dropwise 63 g of diethanolamine to the funnel, and the reaction was continued until the epoxy stage of the system became 20000 or more. After the reaction was completed, the system was diluted with the same weight mixed solvent of methyl isobutyl ketone and toluene so as to have a powder content of about 60% by weight.

The hydroxyl value of the obtained resin itself is 180 mg-KOH / g, 60.3% in the non-volatile content of the resin solution, and toluene threshold (reaching to a turbidity when toluene is added to 100 g of the resin solution at 25 ° C). The added weight of toluene up to) was infinite.

Next, white tar urethane paint was prepared from the polyol resin thus obtained, and various performance evaluations were performed.

[Preparation of White Tar Solution]

Using a condensate of xylene and formaldehyde (average molecular weight 400: viscosity 750 cps / 50 ° C) as a white tar component, dilute the resin component to 60% by weight with a xylene / cyclohexane (9/1 weight ratio) mixed solvent and white tar solution Was prepared.

[Preparation of Paint]

Main components: 100 parts of the above polyol resin solution, 130 parts of white tar solution, 100 parts of talc (asada milling import talc), 16 parts of titanium white (Ishihara Industries, trade name Taibek R-820), thixotropic agent (Iv) (Japan Aerodrome # 300) 1 part was mixed and manufactured using the sand mill.

Curing agent: Toluene diisocyanate-based curing agent (Tadada Pharmaceutical Co., Ltd. trade name Takenate D-102) was used.

Mixing ratio of a main component and a hardening | curing agent: It mix | blended so that the molar ratio of the hydroxyl group of the polyol resin in a main body, and the isocyanate group in a hardening | curing agent might be NCO / OH = 0.8.

[Evaluation of paint]

[Dryness]

After applying the compound coating to the polished mild steel sheet (SS41) having a thickness of 0.3 mm, the needle was prevented from penetrating into the wet-like coating film having a film thickness of 50 µm at 20 ° C. using a Gardner type drying time measuring instrument (manufactured by Uejima). The time was measured as the semi-cured time.

[Pencil strength]

It measured according to JISK-5400 at 20 degreeC with the test piece used for the drying test.

[Foaming status]

The blended paint was cured in a polyethylene cup at 20 ° C. and cut in a thickness direction of about 4 cm to observe the foaming state in the cured product.

[Impact resistance]

After degreasing, the compound coating was applied to a mild steel plate (SS41) having a thickness of 2 mm sandblasted (SG # 100), and a test plate having a dry film thickness of about 200 μm was prepared. After curing this test plate at 20 degreeC for 1 month, it tested according to JISK5400 using the DuPont impact tester.

(Shape diameter 1/2 inch, weight 500g, test temperature 20 ℃)

[Flexibility]

According to JIS K 5400, the test piece of 50 micrometers of dry film thicknesses was created. After the test was cured for 1 month at 20 ° C., the test piece was carried out using a shaft having a diameter of 4 mm, and the case where no crack or peeling occurred in the coating film was set to “pass” (test temperature 20 ° C.).

[Chemical Resistance]

After degreasing the mild steel plate and rounding the corners and the edges around it with a line, the compounding paint was applied to the mild steel plate (SS41) obtained by sandblasting (SG # 100) treatment in accordance with JIS K 5400, and the dry film thickness was about 200. A test plate of μm was produced (the corners and edges of the test plate were coated so that the coating film did not become thin).

After curing this test plate at 20 degreeC for 1 week, it immersed to the height of 1/2 of a test plate in the following test liquid (test temperature 35 degreeC).

Under 7 conditions, if a blast does not generate | occur | produce for 7 days, it was "passed".

Test solution composition 1000 ml of distilled water

50 g of salt

Acetic Acid 10ml

30% H ₂ O ₂ 5g

The results are shown in Table-1 below.

Example 2

In Example 1, except for using 160 g of bisphenol A instead of 317 g of bis (nonylphenol) F used in the term of the synthesis | combination of a polyol resin, the synthesis | combination of polyol resin and preparation of paint were carried out similarly to Example 1.

The results are shown in Table-1 below.

Example 3

Except for changing 726 g of epoxy resin used in Example 1, 605 g of bisphenol A epoxy resin having an epoxy equivalent of 189 was used, and the amount of bis (nonylphenol) F and diethanolamine was changed to 530 g and 91 g, respectively. Similarly, the synthesis | combination of polyol resin and coating material were prepared.

The results are shown in Table-1 below.

Example 4

In Example (3), the synthesis | combination of polyol resin and preparation of paint were carried out similarly to Example 3 except having used 64 g of N-methylethanolamine instead of 63 g of diethanolamine.

The results are shown in Table-1 below.

Example 5

In Example (3), polyol resin was synthesized and paint was prepared in the same manner as in Example 3 except that 118 g of p-isopropylphenol was used instead of 91 g of diethanolamine.

The results are shown in Table-1 below.

Example 6

In Example (3), the reaction was continued while dropping 91 g of diethanolamine slowly without adding N, N-dimethylbenzylamine and continuing the reaction until the epoxy equivalent of the system became 20000 or more. Synthesis | combination of polyol resin and preparation of paint were implemented.

The results are shown in Table-1 below.

Example 7

[Synthesis of bis (hydroxyoctylphenyl) methane]

In Example (1), except for using 1444 g of octylphenol instead of nonylphenol, phenol was synthesized in the same manner as in Example 1 to obtain bis (hydroxyoctylphenyl) methane (hereinafter referred to as bisoctylphenol F). .

[Synthesis of Polyol Resin]

In Example (3), it carried out similarly to Example 3 except using 497 g of bisoctylphenol F obtained by said operation instead of 530 g of bisnonylphenol F.

The results are shown in Table-1 below.

Example 8

In Example (3), 173 g of bisphenol ADphenol, 1,1'-bis (4-hydroxyphenyl) ethane and acetaldehyde 554 g of bisphenol-type epoxy resin obtained in place of the bisphenol A type epoxy resin were used. The same method as in Example 3 was followed.

The results are shown in Table-1 below.

TABLE 1

Comparative Example 1

In Example 3, the same method as in Example 3 was taken except that 267 g of bisphenol A was used instead of bisnonylphenol F. The hydroxyl value of obtained resin was 298 mg / KOH / g.

Moreover, the obtained resin was diluted so that non volatile matter might be about 60 weight% using the same weight mixed solvent of methyl isobutyl ketone-toluene, and it became a non-uniform solution completely.

Comparative Example 2

In Comparative Example 1, the same method as in Comparative Example 1 was taken except that 118 g of p-isopropylphenol was used instead of diethanolamine.

The hydroxyl value of obtained resin was 194 mg-KOH / g, and the non volatile matter of the resin solution was 59.6 weight%.

Next, an attempt was made to prepare the paint in the same manner as in Example 1 using the above polyol resin solution, but the polyol resin and the white tar were separated from each other, and thus the paint could not be prepared.

Claims (11)

A polyol resin composed of the following components (a) and (b), wherein the epoxy group is substantially free: (a) a bisphenol type epoxy resin containing an alkyl-substituted phenol component of the following formula as at least a part of the bisphenol component;

[Wherein R is a group -CH _2- , -CHCH _3- , -C (CH ₃ ) _2- ,

R 'is an alkyl group having 4 or more carbon atoms and n is a number of 1 or 2.] (b) A reaction product with an active hydrogen-containing compound having reactivity with an epoxy group. The polyol resin according to claim 1, wherein at least 20 mol% of the bisphenol component is an alkyl substituted phenol component. The polyol resin according to claim 1, wherein the alkyl-substituted phenol component is bis (hydroxy nonyl) methane. The polyol resin according to claim 1, wherein the alkyl substituted phenol component is bis (hydroxy octyl) methane. The polyol resin according to claim 1, wherein the bisphenol type epoxy resin is an epoxy resin represented by the following formula (II).

In formula, X is a hydrogen atom or a methyl group, m is an integer of 0-15, Z is following formula (III) or formula (IV), or a combination thereof.

Wherein R is a group -CH _2- , -CHCH _3- , -C (CH ₃ ) _2- ,

R 'is a C4 or more alkyl group, n is a number of 1 or 2. The polyol resin according to claim 1, wherein the active hydrogen-containing compound is an alkanol amine having 2 to 20 carbon atoms. 7. The polyol resin according to claim 6, wherein the alkanol amine is diethanol amine. The polyol resin according to claim 1, wherein the active hydrogen-containing compound is phenols having 6 to 30 carbon atoms. The polyol resin according to claim 1, wherein the polyol resin is obtained by reacting the epoxy group in the component (a) so that the active hydrogen equivalent ratio of the component (b) is 0.95-1.05. The polyol resin according to claim 1, wherein the polyol resin has a number average molecular weight of 500 to 6000 and a hydroxyl value of 50 to 1000 mg-KOH / g. (A) A urethane-based paint composed of (B) and (C): (A) A polyol resin composed of the following (a) and (b) and having almost no epoxy groups. Bisphenol-type epoxy resin containing a substituted phenol component,

Wherein R is a group -CH _2- , -CHCH _3- , -C (CH ₃ ) _2- ,

(R 'is an alkyl group having 4 or more carbon atoms, n is a number of 1 or 2) (b) A reaction product with an active hydrogen-containing compound which is reactive toward an epoxy group. An organic solvent containing (B) polyisocyanate or blocked polyisocyanate, and (C) aromatic hydrocarbon.