JPH11171969A - Modified epoxy resin, its production and coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin useful for coatings having excellent corrosion-resistance, water resistance and solubility in solvents by reacting a bisphenol type epoxy resin with an alkanolamine compound and a fatty acid. SOLUTION: This resin is obtained by reacting (A) a bisphenol type epoxy resin (for example, bisphenol A type epoxy resin) preferably having an epoxy equivalent of 150-5,000 with (B) an alkanolamine compound (for example, a mixture of monoethanolamine with diethanolamine) preferably comprising a primary amine and a secondary amine in a primary amine/secondary amine molar ratio of 90/10 to 10/90 and (C) a fatty acid (for example, linseed oil fatty acid) preferably capable of being derived from a drying oil or a semi-drying oil). The components B and C are preferably used in amounts of 1-50 pts.wt. and 5-100 pts.wt., respectively, per 100 pts.wt. of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified epoxy resin, a method for producing the same, and a paint using the modified epoxy resin.

[0002]

2. Description of the Related Art Generally, a drying oil or a semi-dry modified alkyd resin is used to prevent mold and corrosion of general-purpose metal products.
Although used for anticorrosion paints, the corrosion resistance and water resistance were insufficient. Modification by phenol resin modification or epoxy resin modification has been performed for the purpose of improving corrosion resistance and water resistance, but the corrosion resistance and water resistance are still insufficient, and there is a strong demand for improvement.

On the other hand, some antifungal and anticorrosive paints using a high molecular weight epoxy resin are on the market and exhibit excellent corrosion resistance and water resistance.
In order to obtain excellent coating performance, modification with various materials and high molecular weight are performed. The solubility of these high molecular weight epoxy resins in diluted thinners is reduced due to denaturation by various materials, high molecular weight, etc., and they do not dissolve unless special thinners combined with a certain composition do not dissolve, causing problems in workability etc. is there.

[0004] Among one-pack type epoxy resins, fatty acid-modified epoxy resins obtained by the addition reaction of a fatty acid having an unsaturated bond to the epoxy group of the epoxy resin are on the market.
Fatty acids used for modifying these fatty acid-modified epoxy resins are unsaturated fatty acids that can be derived from drying oils such as soybean oil and linseed oil, and are modified because the fatty acids have long alkyl chains. Has good solubility in diluted thinner. However, in these fatty acid-modified epoxy resins, the molecular weight of the epoxy resin is limited when an attempt is made to modify the fatty acid amount to a certain degree or more in order to obtain thinner solubility because the fatty acid is introduced into the epoxy group by an addition reaction. To adjust the molecular weight of the resin, the molecular weight is increased by isocyanates. However, these resins are inferior in corrosion resistance and water resistance.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a modified epoxy resin which is excellent in corrosion resistance and water resistance and is excellent in solubility in a solvent and is suitable for a paint and a method for producing the same.

Another object of the present invention is to provide, in addition to the above objects,
An object of the present invention is to provide a modified epoxy resin which is excellent in coating film hardness and drying property and is suitable for a paint and a method for producing the same.

Another object of the present invention is to provide a paint having excellent coating film properties such as antifungal and anticorrosion properties and solvent solubility.

[0008]

That is, the present invention provides:
It is intended to provide a method for producing a modified epoxy resin, which comprises reacting (A) a bisphenol type epoxy resin, (B) an alkanolamine, and (C) a fatty acid.

The present invention also provides a process for producing a modified epoxy resin, which comprises reacting the above components (A), (B), (C) and (D) isocyanates.

[0010] The present invention also provides a paint containing the above-mentioned modified epoxy resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The bisphenol type epoxy resin (A) used in the present invention can be obtained by, for example, mixing bisphenol and epichlorohydrin, heating in the presence of a catalyst, and causing an addition reaction.

As the bisphenol, for example, 2,2-
Bis (4-hydroxyphenyl) propane (bisphenol II), bis (4-hydroxyphenyl) methane (bisphenol F) and the like can be mentioned. As a catalyst,
For example, alkali hydroxide and the like can be mentioned, and sodium hydroxide, potassium hydroxide and the like can be mentioned.

As the component (A), commercially available products can be used, and specific examples thereof include Epicoat 828,
Epicoat 1001, epicoat 1004, epicoat 1007, epicoat 1009 (all are trade names of Shell Chemical Co., Ltd.) and the like. The component (A) is used alone or in combination of two or more.

The epoxy equivalent of the component (A) is from 100 to 3
0000, preferably 100 to 10,000.
It is more preferably 0, and further preferably 150 to 5,000. If the epoxy equivalent is less than 100, the resin molecular weight after modification becomes low, and the resulting coating film tends to have poor drying and corrosion resistance. If it exceeds 30,000, solvent solubility and coating film adhesion are poor. There is a tendency.

The alkanolamine (B) used in the present invention has a structure in which at least one hydroxyalkyl group is bonded to a nitrogen atom of the amine, and includes monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine. , Di-2
-Hydroxybutylamine, N-methylethanolamine, N-ethylethanolamine, N-benzylethanolamine and the like. The component (B) is used alone or in combination of two or more.

Although it depends on the molecular weight of the epoxy resin to be used, it is preferable to use a primary amine and a secondary amine together as the component (B) because they are excellent in water resistance, corrosion resistance and the like. 90/10 by mole ratio of secondary amine
It is preferably 10/90. It is preferable to use dialkanolamine as the secondary amine.

The amount of the component (B) is 100 parts (A)
It is preferably from 1 to 100 parts by weight, more preferably from 1 to 50 parts by weight, based on parts by weight. If the amount of the component (B) is less than 1 part by weight, corrosion resistance and adhesion tend to decrease, and if it exceeds 100 parts by weight, water resistance and solvent solubility tend to deteriorate.

The (C) fatty acids used in the present invention include fatty acids and synthetic fatty acids which can be derived from dry or semi-dry oils, such as tung oil, soybean oil, linseed oil, castor oil, dehydrated castor oil, Fatty acids obtained from safflower oil, cottonseed oil, and the like, and versatic acid obtained by synthesis (trade name, manufactured by Shell Chemical Co., Ltd.) are exemplified. As the component (C), it is preferable to use a fatty acid that can be derived from a drying oil or a semi-drying oil, because it can impart room-temperature curability. However, a fatty acid that can be derived from a non-drying oil may be used. The component (C) is used alone or in combination of two or more.

The amount of the component (C) is 100 parts (A).
The amount is preferably 5 to 300 parts by weight, more preferably 5 to 100 parts by weight with respect to parts by weight. If the amount of component (C) is less than 5 parts by weight, water resistance and solvent solubility tend to decrease, and if it exceeds 100 parts by weight, corrosion resistance and drying properties tend to deteriorate.

The isocyanates (D) used in the present invention include aromatic isocyanates, aliphatic isocyanates and alicyclic isocyanates.
Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, meta-xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, methylcyclohexane Examples thereof include -2,6-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, and trimethylhexamethylene diisocyanate. The component (D) is used alone or in combination of two or more.

The amount of the component (D) is as follows:
It is preferably 0 to 50 parts by weight, preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the total of the components (B) and (C).
More preferably, it is part by weight. If the amount of the component (D) exceeds 50 parts by weight, the adhesiveness and solvent solubility tend to decrease.

[0022] The modified epoxy resin of the present invention comprises the above (A)
The component, the component (B) and the component (C) are reacted. From the viewpoint that the dryness and water resistance of the resulting modified epoxy resin are improved, the compound (A) is
Those obtained by reacting the component (D) in addition to the components (B) and (C) are preferable.

The components (A), (B), (C) and (D) are subjected to an addition and condensation reaction by known methods. For example, the addition and condensation reactions may be performed by heating the components (A), (B), (C) and (D) at 50 to 250 ° C. for 1 to 24 hours. This reaction may be carried out in an organic solvent such as xylene which does not react with the components (A), (B), (C) and (D). These organic solvents are used alone or in combination of two or more. In the reaction, the component (A), the component (B), the component (C) and the component (D) may be mixed and reacted at the same time, or the component (A) and the component (B) may be reacted. After that, the component (C) may be reacted, and then the component (D) may be added and reacted so as to react step by step.
After reacting the components (A) and (B), in the reaction of reacting the component (C), the hydroxyl group in the reaction product of the components (A) and (B) reacts with the fatty acid. When reacted in this way, first, the bisphenol-type epoxy resin reacts with the alkanolamine to extend the chain of the polymer, and a number of fatty acids are bonded to hydroxyl groups derived from the alkanolamine. Excellent.

[0024] The heating operation includes the component (A),
The reaction may be performed in an organic solvent that does not react with the component (B), the component (C), and the component (D). Examples of such an organic solvent include toluene, xylene, methyl ethyl ketone, and methyl propylene glycol acetate. These organic solvents are used alone or in combination of two or more.

In the reaction between the component (A) and the component (B), n-butanol, methylpropylene glycol or the like can be used as an organic solvent.

The amount of the organic solvent used is not particularly limited, but is preferably 20 to 3 parts by weight based on 100 parts by weight of the resin solids.
It is preferably 00 parts by weight.

The modified epoxy resin of the present invention obtained by the above-mentioned production method can be suitably used for a paint. Examples of the paint include a cold-drying paint by oxidative crosslinking and a lacquer paint.

Coloring pigments such as carbon and titanium oxide, extender pigments such as talc and calcium carbonate, and rust-preventive pigments such as aluminum phosphomolybdate and zinc phosphate can be added to the paint. The color pigment is preferably blended in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the epoxy resin. Preferably, the extender pigment and the rust-preventive pigment are blended in an amount of 1 to 200 parts by weight based on 100 parts by weight of the epoxy resin.

In the case of a room temperature drying type paint, a metal dryer is further added. Examples of the metal dryer include cobalt naphthenate, zinc naphthenate and the like, and it is preferable that these are blended in an amount of 0.01 to 50 parts by weight based on 100 parts by weight of the epoxy resin. Further, the above-mentioned organic solvent can be used, and the amount of use is not particularly limited, but is preferably 20 to 300 parts by weight based on the solid content of the resin.

[0030]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Epicoat 1001 (bisphenol Α type epoxy resin, manufactured by Shell Chemical Co., epoxy equivalent: 475) in a 2 liter glass flask equipped with an inert gas inlet tube.
620 g, monoethanolamine 30 g, diethanolamine 35 g, xylene 200 g and n-butanol 1
Then, the addition reaction was advanced until the viscosity was saturated at 110 ° C., and then 210 g of linseed oil fatty acid and soybean oil fatty acid 1
After the addition of 05 g, the temperature was raised to 200 ° C. while collecting xylene / n-butanol in the flask, cooled to a resin acid value of 4 as an end point, and diluted with 980 g of xylene to obtain a resin having a heating residue of 50% by weight. Was.

Example 2 In a 2 liter glass flask equipped with an inert gas inlet tube, 620 g of Epicoat 1001 (bisphenol II type epoxy resin, manufactured by Shell Chemical Company), 30 g of monoethanolamine, 35 g of diethanolamine, 150 g of xylene and Add 150 g of methyl propylene glycol and proceed with the addition reaction until the viscosity is saturated at 130 ° C.
Next, after mixing 315 g of dehydrated castor oil fatty acid, the temperature was raised to 200 ° C. while recovering xylene / methylpropylene glycol in the flask, and cooled to a resin acid value of 3 as an end point, followed by dilution with 1150 g of xylene. Next, the temperature was raised to 100 ° C., and 50 g of HDI (hexamethylene diisocyanate, manufactured by Nippon Polyurethane Co., Ltd.) was added. After confirming that the viscosity of the resin was saturated, cooling was performed to obtain a resin having a heating residue of 45% by weight.

Example 3 In a 2 liter glass flask equipped with an inert gas inlet tube, Epicoat 1007 (bisphenol II type epoxy resin, manufactured by Shell Chemical Company, epoxy equivalent 192)
5) 750 g, 41 g of diethanolamine, xylene 2
Then, the addition reaction was allowed to proceed until the viscosity was saturated at 110 ° C., and then 210 g of linseed oil fatty acid was added. Thereafter, the temperature was raised to 200 ° C. while recovering xylene / n-butanol in the flask. , Resin acid value 4
, And diluted with 980 g of xylene. Next, the temperature was raised to 100 ° C., and 50 g of HDI (hexamethylene diisocyanate, manufactured by Nippon Polyurethane Co., Ltd.) was added. After confirming that the resin viscosity was saturated, the mixture was cooled to obtain a resin having a heating residue of 45% by weight.

Comparative Example 1 In a 2 liter glass flask equipped with an inert gas inlet tube, 951 g of Epicoat 1001 (bisphenol type epoxy resin, manufactured by Shell Chemical Company), 29.0 g of monoethanolamine and 20.0 g of diethanolamine
g was mixed with 400 g of xylene, and the addition reaction was allowed to proceed at 130 ° C. until the viscosity was saturated.
g, diluted with 200 g of n-propyl cellosolve to obtain a modified polymer epoxy resin having a heating residue of 50% by weight.

Comparative Example 2 In a 2 liter glass flask equipped with an inert gas inlet tube, 750 g of Epicoat 1001 (bisphenol エ ポ キ シ type epoxy resin, manufactured by Shell Chemical Company) and 250 g of soybean oil fatty acid were mixed, and the viscosity was measured at 200 ° C. The addition reaction was proceeded until was saturated, and diluted with 1,000 g of xylene. Thereafter, 20 g of hexamethylene diisocyanate is added and 10
The chain elongation reaction was allowed to proceed at 0 ° C. until the viscosity was saturated, and a modified polymer epoxy resin having a heating residue of 50% by weight was obtained.

Evaluation method (Results are shown in Table 3.) (1) Solvent solubility (tolerance) test: The resin inside is dissolved while a test solvent is placed in a transparent Erlenmeyer flask containing 10 g of the resin. The point at which the diluted solution in the Erlenmeyer flask becomes cloudy is defined as the end point. Tolerance value = amount of test solvent / resin (g) (2) Coating film property test: The modified epoxy resin obtained in each of Examples and Comparative Examples was coated with the following composition (weight ratio) and subjected to various tests. . Table 1 shows the paint formulation and Table 2 shows the thinner formulation.

[0037]

[Table 1]

[0038]

[Table 2] The viscosity of the paint dispersed with a paint shaker was adjusted for 16 seconds with an Iwata cup using a thinner, and applied to an untreated steel sheet by air spray so as to have a dry film thickness of 30 μm.
Test for 5 days after drying with JIS K 5400
Compliant).

[0039]

[Table 3]

[0040]

The coating composition using the modified epoxy resin of the present invention has excellent solvent solubility and excellent coating properties such as water resistance, corrosion resistance and hardness.

Claims (5)

[Claims] (1) a bisphenol type epoxy resin,
A method for producing a modified epoxy resin, comprising reacting (B) an alkanolamine and (C) a fatty acid. 2. The process for producing a modified epoxy resin according to claim 1, wherein component (A), component (B), component (C) and isocyanates (D) are reacted. 3. An addition reaction of (A) a bisphenol type epoxy resin with (B) an alkanolamine,
3. The method for producing a modified epoxy resin according to claim 1, wherein (C) a fatty acid is reacted. 4. A modified epoxy resin produced by the production method according to claim 1, 2 or 3. 5. A coating comprising the modified epoxy resin according to claim 4.