JPS58215463A - Epoxy resin composition for paint - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which gives a cured coating film having excellent adhesion, flexibility, resistance to water and corrosion, etc., by crosslinking a modified epoxy resin with a specified crosslinking component, said epoxy resin being modified with a dimer acid and a butadiene/acrylonitrile copolymer. CONSTITUTION:10-100pts.wt. dimer acid and 3-40pts.wt. carboxyl group- terminated butadiene/acrylonitrile copolymer are added to 100pts.wt. bisphenol A type epoxy resin having an epoxy equivalent of 170-1,000. The mixture is reacted to prepare a modified epoxy resin, which is then crosslinked by using a crosslinking component selected from aliph. and/or arom. diamine (A), dibasic acid (anhydride) (B), amine adduct (C) obtd. from an epoxy resin and an excess amount of diamine, and polyamide (D) obtd. by condensing a dimer acid with a diamine, to obtain the desired epoxy resin compsn. for paint.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition that forms a cured coating film that has excellent adhesion and excellent flexibility even at low temperatures.

The cured coating film obtained by crosslinking epoxy resin with a crosslinking component has excellent corrosion resistance, adhesion, and chemical resistance, so it is widely used as a vehicle for general rust prevention and heavy rust prevention.
Because it is too hard, it has the disadvantage of poor impact resistance and bending resistance.

In order to eliminate this drawback, as a crosslinking component, dimer acid (an unsaturated fatty acid polymerized by heating, for example, commercially available products such as Persadime 216, manufactured by Hengle Nippon Co., Ltd., trade name) and diamine. (commercially available as reactive polyamide, hereinafter abbreviated as polyamide), or long-chain amines, and as plasticizers, polyvinyl chloride, other vinyl polymers, and Addition of 7-talic acid esters such as tilt terephthalate is being carried out. However, in the former case, sufficient flexibility cannot be obtained, and in the latter case, the retention properties with the epoxy resin are generally poor, and corrosion resistance and chemical resistance are significantly reduced. Therefore, in order to eliminate these drawbacks, a method of reacting an epoxy resin with a dimer acid has been adopted, and a typical commercial product is Evol--).
YD-172 (manufactured by Tobu Kasei, trade name), Ebicuron 16
00 (manufactured by Inu Nippon Ink Chemical Industry Co., Ltd., trade name). 1- However, although epoxy resin modified with dimer acid shows improvements in flexibility, smoothness, dilutability with organic solvents, pigment fractionation, etc., it loses adhesion, which is the characteristic of epoxy resin itself. It has the disadvantage of

On the other hand, in order to improve the flexibility of epoxy resin, a method of modifying it with a butadiene-acrylonitrile copolymer having a carboxyl group at the terminal has been proposed (Japanese Patent Laid-Open No. 55
-84371, JP-A-56-122823). With this method, it is possible to impart flexibility without impairing adhesion, but for this purpose, if a sufficient amount of butadiene-acrylonitrile copolymer having a carboxyl group at the terminal is used, water resistance is achieved. The corrosion resistance, corrosion resistance, and dilutability to organic agents deteriorate. In addition, the butadiene-acrylonitrile copolymer having a carboxyl group at its terminal is more expensive than dimer acid or epoxy resin, so it has the disadvantage of making the product more expensive.

The purpose of the present invention is to eliminate the drawbacks of the above conventional products, improve adhesion, =
An object of the present invention is to provide an epoxy resin composition for paints which provides a cured coating film with excellent T-flexibility (particularly low-temperature flexibility), water resistance, corrosion resistance, and dilutability with organic solvents, and which is highly economical.

In order to achieve this objective, the present inventors have conducted various studies and found that 1 part by weight of dimer acid is
0 to 100 parts by weight and 3 to 40 parts by weight of a butadiene-acrylonitrile copolymer having a carboxyl group at the end, and a tertiary amine such as triethylamine, benzyldimethylamine, tetramethylammonicum chloride, etc. Modified epoxy resin (hereinafter referred to as modified epoxy) obtained by ashing in the range of 130 to 200°C in the presence of a quaternary ammonium salt, a trialkyl such as triallylphosphine, or a catalyst such as triallylphosphine.
It is called resin (I). ), a crosslinking component (e.g. diethylenetriamine, aliphatic amines such as diethylenetriamine, aromatic amines such as 4<4'diaminodiphenylmethane, tridimethyaminomethylbenzene, phthalic anhydride, maleic anhydride). An epoxy resin composition obtained by crosslinking with an acid anhydride (dibasic acid), an amine adduct obtained from an epoxy resin and an excess diamine, the above-mentioned polyamide resin which is a condensation product of a dimer acid and a diamine, etc. They have discovered that a coating film can be formed that satisfies all of the following: , flexibility (particularly flexibility at low temperatures), adhesion, water resistance, corrosion resistance, dilutability with organic solvents, and chemical resistance.

The mixing ratio of the modified epoxy vinyl(I) and the crosslinking component is
It varies depending on the epoxy equivalent of the track number and the sensory tyranny in one molecule of the latter, but for 100 parts by weight of the former, for example, when using an aliphatic or aromatic diamine as a crosslinking component, 10 to 100 parts by weight, polyamide 10 when using
~100 parts by weight, 15-1 when using an amine adduct
00-1 part by weight, preferably 10 to 70 parts by weight when an acid anhydride is used.

When the amount of crosslinking component is less than the lower limit of the above range, generally
Crosslinking becomes insufficient, which particularly affects chemical resistance and water resistance. Moreover, when the upper limit of the above range is exceeded, non-reactive functional groups such as amino groups and carboxyl groups are present, which adversely affects water resistance and the like.

Modified epoxy resin (as a raw material for D, epoxy equivalent: 17
The reason for using a bis7 epoxy resin having a weight of 0 to 1000 is that trifunctional epoxy groups with an epoxy equivalent weight of less than 170 cannot be synthesized, and the epoxy equivalent weight is 1000.
Exceeding the modified epoxy (resin) becomes highly viscous and becomes impractical. Typical commercially available products include:
Epicoat 815J, l'-Epicoat 828", [Ebikoa] 834 J, "Epicoat 1001", "Epicoat 1004J (all made of Yuka shell epoxy ■, trade name), "Evo-to YI)-115J,"
"Evoto 128", "Epoto
- To 134'', [Eboto) 011 J,
Examples include "Evotote 014" (manufactured by Tobu Kasei ■, trade name).

The getadiene/acrylonitrile copolymer having a carboxyl group in Xi preferably has a molecular weight of 2,000 to 5,000 and an acrylonitrile content of 10 to 40% by weight, and is called a liquid rubber. Hiker 0TBN 1300X8 J (B.

F, Goodlynch Co., product name), [Nyball D N
601j (manufactured by Nippon Zeon Co., Ltd., trade name).

In the present invention, the reason why the amount of dimer acid is limited to 10 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin is as follows.
If it is less than 100 parts by weight, sufficient flexibility cannot be obtained, and if it is more than 100 parts by weight, the inherent adhesion of the epoxy resin
This is because corrosion resistance and chemical resistance are impaired. In addition, the butadiene-acrylonitrile copolymer having a carboxyl group at the end is limited to 3 to 40 parts by weight because less than 3 parts by weight has little effect on flexibility, adhesion, and low-temperature properties.
In addition, if more than 40 weight ψ parts is used, water resistance and corrosion resistance will deteriorate, and the viscosity will be high, resulting in poor workability, and the epoxy resin's l! JU properties are impaired, and sufficient adhesion and flexibility can be provided by using 40 parts by weight or less, so considering the high price of this product, it is economical to use as little as possible. It is.

It goes without saying that the epoxy resin composition for paints of the present invention not only consists of the modified epoxy resin (1) and the crosslinking component, but also includes pigments and other commonly used additives. , a small amount of epoxy equivalent 1
Even if it contains a bisphenol A-based epoxy resin with a molecular weight of more than 000 and less than 2,200, or a small amount of other unconventional additives, as long as it exhibits substantially the same effect as the present invention, the technical aspects of the present invention apply. It belongs to the range.

As mentioned above, the epoxy 1,1]W composition for coatings of the present invention has flexibility (especially low temperature flexibility), adhesion, water resistance,
This is an excellent coating composition that provides satisfactory results in all properties, including corrosion resistance and dilutability according to the mechanical fermentation rule, and should be widely used.

Next, examples will be given to specifically explain the invention.

Example 1 Bisphenol AM epoxy resin “Epicote 1001”
j (Epoxy equivalent: 4501 made by Yuka Shell Epoxy ■) 100 g and dimer acid "Versadime 216"
(manufactured by Henkel Niki Co., Ltd., trade name) 15gs liquid rubber (butadiene-acrylonitrile copolymer with carboxyl group at the end) [Hiker C! TBN 1300X8J (
35 g of B, F (product name, manufactured by Gutdrich) and 0.1 g of triethylamine were placed in an F5 vessel (No. 11) equipped with a thermometer, stirrer, and reflux condenser, and heated to 150°C while stirring. for 5 hours, and then add 100g of xylene.
was added to obtain a modified epoxy resin bath liquid (A) having a solid content of 6 ml and an epoxy equivalent of 10]4.

Next, 100 g of this modified epoxy) @fat bath solution (1) was mixed with 12 g of calcium carbonate (745 g) and 24 g of talc, and dispersed with three rolls. After that, "Persamide 125 J zog" was combined with rC and spray-painted. Suitable viscosity: 1=1 of toluene and ethyl acetate (diluted with 4% solvent by weight, 150 vtnt x 70g x x O
, 7wts soft J144F (JISG3141), dried at 20℃ for 7 days, 1st thickness 10
A cured coating film +TL of 0 voice was obtained.

Example 2 Bisphenol A-based epoxy resin “Epicote 1004”
j (Epoxy equivalent L 950) 100 g,
r Versaguim 216415g, liquid rubber ``hiker 0''
TBN 1300X8j15g,) ethylamine 0.
1 g was placed in the same device as in Example 1, and while stirring, 15
The mixture was kept at 0° C. for 5 hours, and 87 g of xylene was further added to obtain a modified epoxy resin solution ω) having a solid content of 960% and an epoxy equivalent of 3023.

A cured coating film (2) with a film thickness of 100 coats was obtained by carrying out the same operation as in Example 1, except that 15 g of "Persamide 115" was distributed as the 4a agent.

Example 3 Bisphenol AM epoxy resin [Epicote 828
J (epoxy equivalent weight 175) 100 E, r Versaguim 216 J 50 g, liquid rubber 1-Nipol 601 j (manufactured by Nippon Zeon (HA) → trade name) 25 g
,) 0.1 g of ethylamine was placed in the same container as in Example (1) and kept at 150°C for 5 hours while stirring.
Furthermore, 117 g of pheasant roll was added, and the solid content was 60%.
Liquid resistant epoxy resin with solid content epoxy equivalent of 470 (
C) was obtained.

As a crosslinking agent, amine adduct m liquid ([Epicote 10
It was prepared from 32.5 parts of 01 J, 7.5 parts of diethylenetriamine, 30 parts of n-butanol, and 30 parts of xylene. A cured coating film (3) with a film thickness of 100 μm was obtained by the same operation as in Example 1 except that 125 g of chloride was added.

Example 4 Bisphenol A-based epoxy resin “Evototo YD-1”
28J (epoxy equivalent: 190, manufactured by Tobu Kasei @, trade name)
100 g, r Parsaqui A 216 J 80
g, liquid comb “hiker cTBN13oo x 8” 10
g1 0.1 g of triethylamine was placed in the same device as in Example 1, kept at 150°C for 5 hours with stirring, 127 g of xylene was added, and a y-based epoxy resin (D ) was obtained.

A cured coating film (4) with a thickness of 100 p was obtained by carrying out the same operation as in Example 1, except that 70 g of an amine adduct solution (same as in Example 3) was blended as a crosslinking agent.

Example 5 Add 100,130 g of Ebiko to 70 g of the modified epoxy resin solution obtained in Example 3, heat and dissolve, and then add 20 g of xylene to obtain a modified epoxy resin with a solid content of 60% and an epoxy equivalent of 464. A solution (g) was obtained.

A cured coating film (6) having a thickness of 100 μm was obtained by the same operation as in Example 1 except that 40 g of [Persamide 115 J] was blended as a crosslinking agent.

Comparative Example 1 Bisphenol A-based epoxy resin [Epicote 1001
J 100 g, “Parsa Dime 216 J 20
g, liquid rubber [Hiker 0TBN 130 (J X 8
J Igr, ) 0.1 g of ethylamine was placed in the same apparatus as in Example 1 and kept at 150°C for 5 hours with stirring, then 82 g of xylene was added to give a solid content of 60%.
A quality epoxy resin solution with a solid content epoxy equivalent of 825 (
The ratio A) was obtained.

The same operation as in Example 1 was carried out except that 20 g of Perzamide 125 J was added as the crosslinking residue, and iJ'ffJ
A cured coating of 100 mm [(ratio 1) was obtained.

Comparative Example 2 Bisphenol A-based epoxy resin “Epicote 828”
J 100 g, rpersamide 2164120 g
, liquid rubber [hiker aTBw 1300 x 8 J
20g of triethylamine, 0.1g of triethylamine were placed in the same apparatus as in Example 1, and heated to 150°C for 55 minutes with stirring.
After the time was maintained, 160 g of xylene was further added to obtain a modified epoxy resin liquid (ratio B) having a solid content of 6 mol and a solid content of epoxy fi 1818.

A cured coating film (ratio 2) with a film thickness of 100) t was obtained by carrying out the same operation as in Example 1, except that 40 g of an amine adduct solution (same as in Example 3) was blended as a crosslinking agent.

Comparative Example 3 Bisphenol A-based epoxy resin “Epicote 828”
J 100 g, r Versaguim 216 J 5 g
, Liquid Rubber [Hiker 0TBN 13oo x 8
J 30g5l-IJ s, f Ruamino 0.1g, 4
11 times, it was kept at 15 o'C for 5 hours, and 99 g of xylene was added to obtain a modified epoxy resin solution (ratio C) with a solid content of 60 and an epoxy equivalent of 252, but the solubility in xylene was Due to the rattan, the resin solution became opaque.

A cured coating film (ratio 3) with a film thickness of 100 mm was obtained by carrying out the same treatment as in Example 1 except that 35 g of Persamide 115 J was blended as a crosslinking agent.

Comparative Example 4 Bisphenol A-based epoxy resin “Epicote 828”
J 100 g, l'-persamide 216420 g,
Liquid rubber “Hiker cTBN 1300 X 8 J
50 g, ) 0.1 g of ethylamine in Example 1
The mixture was placed in the same apparatus as in Comparative Example 3, and after being kept at 150°C for 5 hours with stirring, 113 g of xylene was further added to obtain a modified epoxy resin solution with a solid content of 6 light and a solid content of epoxy equivalent of 360. As in the case of , the resin solution was opaque, had a high viscosity, and had no flowability at 30''C.

Comparative Example 5 Bisphenol A-based epoxy resin “Epicote 1001”
J 100 g % - 67 g of xylene was dissolved in a VC bath to obtain an epoxy autopsy solution.

A film thickness of 1
00] was obtained.

Comparative Example 6 Bisphenol A-based epoxy resin [Epicote-182
8J 100 g, r Versaguim 216 J 80
g, 0.1 g of triethylamine while stirring,
The mixture was kept at 150° C. for 5 hours, and 120 g of xylene was added thereto to obtain a dimer acid-modified epoxy resin solution with an epoxy equivalent of 632 and a solid content of 6 mm.

A cured coating film (ratio 6) with a thickness of 100 mm and II was obtained by carrying out the same treatment as in Example 1, except that 100 g of amine adduct M liquid (same as in Example 3) was blended as a crosslinking agent.

Comparative Example 7 Bisphenol AM epoxy resin “Epicote 1001”
J! 00 g% Liquid Rubber [Hiker 0TBN 1
300 X8J30g,) 0.1g of ethylamine,
While stirring, keep at 150℃ for 5 hours and add 73g of xylene.
was added to prepare a liquid rubber-modified epoxy resin 76 liquid containing 60% solids with an epoxy equivalent of 537. However, as in Comparative Example 3, the resin was opaque (liquid).

%) The same treatment as in Example 1 was carried out except that 100 g of amine adduct solution (same as in Actual Example 3) was added as a preservative, and a curing chamber with a film thickness of 100 mm was prepared! (ratio 7) was obtained.

Comparative Example 8 50 g of dimer acid-modified epoxy resin solution obtained in Comparative Example 6
50 g of the liquid rubber-modified epoxy resin solution obtained in Comparative Example 7
was added, resulting in an opaque resin solution of both resin mixtures (epoxy equivalent: 585).

Fruit, except that 100 g of amine adduct solution (same as in Example 3) was added as a chestnut 1-altering agent. i1 The same treatment as in Example 1 was carried out to obtain a cured coating film (8) having a film thickness of 1θθμ.

The results of testing the cured coating films of each Example and Comparative Example are summarized in Table 1. However, all measurement methods are: JIE3
The test was conducted based on K-5400 (General Test Methods for Paints). In addition, for the bending test at -5°C, the test plate was heated to -5°C.
The test was carried out after being left in a thermostat for one day.

-Me”11 Two 1 1-cho~1 (18)

Claims (1)

[Claims] 10 to 10 parts of dimer acid per 100 parts of bisphenol h-based epoxy resin of 170 to 1000 parts of epoxy resin
With a modified epoxy resin obtained by adding and reacting 0 parts by weight and 3 to 40 parts by weight of a butadiene-acrylonitrile copolymer having a carboxyl group at the end; an aliphatic or aromatic diamine, a dibasic acid or its anhydride; An epoxy resin composition for paint, comprising an epoxy resin, an amine adduct obtained from an excess of diamine, and at least one crosslinking component selected from a polyamide obtained by condensing dimer acid and diamine.