JPH0119698B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention improves the leafing properties of aluminum pigments, and does not particularly require undercoating or topcoating.
The present invention relates to a paint composition that can be finished in one coat. Leafing type aluminum pigment-containing epoxy resin paints are generally used for steel towers, bridges, tanks, etc.
It has been used in a wide variety of applications, including vehicles. However, with conventional leafing-type epoxy resin paints containing aluminum pigments, it is not always possible to obtain a coating film with satisfactory leafing properties.
Therefore, it is often not possible to obtain a coating film with an aluminum feel,
Moreover, weather resistance etc. were also poor. Furthermore, since it is an epoxy resin paint, special care must be taken in treating the metal surface, and a high degree of surface treatment is usually required by sandblasting or other blasting treatment.
Therefore, in consideration of rust prevention properties, adhesion, etc., a method has been used in which an epoxy resin primer is usually applied and a leafing type epoxy resin paint containing aluminum pigment is applied thereon. In view of the above-mentioned current situation, the present invention has been developed to improve the leafing properties of aluminum pigments, to be able to coat objects with a wide range of metal substrate treatment levels, and to contain leafing-type aluminum pigments that can be used as both an undercoat and a topcoat. The object of the present invention is to provide an epoxy resin coating composition. Such a purpose is to combine a phosphoric acid, which is a phosphorus oxygen acid, an ester or a salt thereof, having at least one P-OH bond, and an epoxy resin in an amount of the phosphoric acid per equivalent of the epoxy group in the epoxy resin. Hydroxyl group is 0.05~
Modified resin obtained by reacting at a ratio of 0.5 equivalent
(i), hardening material (ii), leafing type aluminum pigment (iii), and (a) general formula P-(S-CnH _2o+1 ) ₃ , P-(S-CnH _2o - ₁ ) ₃ , P
―(S―CnH _2o ― ₃ ) ₃ , or P―(S―CnH _2o ― ₅ )
₃ [However, it is an integer of 26 or less] Phosphite trithioalcohol compound or one of the thioalcohol groups in the above general formula
Compounds (iv) in which ~2 atoms are substituted with phenol, thiophenol aliphatic alcohol, polyhydric alcohol, or derivatives thereof, or (b) triphenyl phosphite or a part of the hydrogen atoms of the phenyl group of triphenyl phosphite This is achieved by an epoxy resin coating composition characterized by comprising a compound (iv) substituted with an alkyl group (hereinafter, compounds (iv) in (a) and (b) are referred to as phosphorous acid compounds). Ru. Conventionally, paints whose main components are an epoxy resin base component, a curing agent component, and an aluminum paste component have been used in the form of three-component paints, but with the paint composition of the present invention, a phosphorous acid compound is blended. Even if the aluminum paste component is mixed in advance with the main component, gelation does not occur, and therefore it is possible to form a two-component paint, resulting in good painting workability. A layer of overlapping aluminum flakes is formed on the coating surface, resulting in a coating with a good appearance and excellent weather resistance and rust prevention. Furthermore, as described above, since the paint according to the present invention has the functions of both an undercoat and a topcoat, it can be used as both an undercoat and a topcoat in one application, and the painting process can be shortened. The modified resin comprises an epoxy resin and a phosphorus oxygen acid, its ester or salt (hereinafter, these compounds are referred to as phosphoric acids) having a P-OH bond,
The ratio is such that the epoxy group remains, usually 50~
It is obtained by heat treatment at 130℃.
Has chelate reactivity. Various epoxy resins can be used here, including those having more than one glycidyl ether group in the molecule, and preferably those having an epoxy equivalent of about 150 to 2,100. Examples of the phosphorus oxygen acid having a P--OH bond include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, phosphinic acid, and the like. Examples of esters of phosphorus oxyacids include alkyl esters having 1 to 8 carbon atoms and hydroxyalkyl esters of the phosphorus oxyacids. Examples of the salts of phosphorus oxygen acids include lithium, sodium, potassium, calcium, zinc, barium, aluminum, and tin salts of the phosphorus oxygen acids. The reaction between the epoxy resin and the phosphoric acids is preferably carried out at a ratio of 0.05 to 0.5 equivalents of hydroxyl groups in the phosphoric acids per equivalent of epoxy groups in the epoxy resin, and the epoxy equivalent of the obtained chelate-reactive modified resin is
It is appropriate to set it to 3000 or less. The epoxy equivalent is
If it exceeds 3000, the viscosity becomes too high and it cannot be used as a paint from the viewpoint of workability, etc., which is not preferable. By using this modified resin, it is possible to coat objects with a wide range of metal surface treatment degrees, and a coating film with excellent rust prevention properties, adhesion properties, etc. can be obtained. As the curing agent, a normal curing agent for epoxy resins can be used. For example, aliphatic polyamines such as diethylenetriamine and triethylenetetramine, aromatic polyamines such as metaphenylenediamine and diaminodiphenylmethane, and polyamide resins can be used. The appropriate amount of the curing agent used is 0.5 to 1.0 equivalent relative to the epoxy equivalent of the modified resin. As the leafing type aluminum pigment, those commonly used in this type of paint can be used, but paste-like pigments whose surface has been treated with stearic acid or the like are particularly preferred. For example, commercially available products include Altop (manufactured by Tokai Kinzoku Co., Ltd.), Aluminum Paste Sap (manufactured by Showa Aluminum Powder Co., Ltd.), Alpaste (manufactured by Toyo Aluminum Co., Ltd.), Eterna Bright (manufactured by Silver Line Co., Ltd.), and Stapa (manufactured by Asahi Kasei Industries, Ltd.). Can be used. The appropriate amount of leafing type aluminum pigment to be used is usually 5 to 100 parts by weight per 100 parts by weight of the modified resin. In the present invention, a phosphite trithioalcohol compound and a phosphite triphenyl compound can be typically used as the phosphorous acid compound. As a phosphite trithioalcohol compound, the general formula is P-(S-CnH _2o+1 ) ₃ ,P-(S-CnH _2o - ₁ ) ₃ ,P
Phosphite trithioalcohol compounds represented by -(S-CnH _2o - ₃ ) ₃ and P-(S-CnH _2o - ₅ ) ₃ can be typically used. Note that in the general formula, the n value is an integer of 26 or less. Compounds with an n value exceeding 26 are not preferred because they have poor compatibility with other components. Further, as a derivative of the above compound, one in which one or two of the thioalcohol groups in the above general formula is replaced with a polyhydric alcohol such as phenol, thiophenol, aliphatic alcohol, polyethylene glycol, or a derivative thereof can be used. Examples of the triphenyl phosphite compound or a compound in which a part of the hydrogen atoms of the phenyl group of triphenyl phosphite are replaced with an alkyl group include triphenyl phosphite [P-(OC ₆ H ₅ ) ₃ ], phosphorous acid Tricresyl [P-(OC ₆ H ₄ CH ₃ ) ₃ ], Trixylenyl phosphite [P-(OC ₆ H ₃ (CH ₃ ) ₂ ) ₃ ], Trisnonylphenyl phosphite [P-(OC ₆ H ₄ C ₉ H ₁₉ ) ₃ ], diphenyl monocresyl phosphite

[Formula] etc. can be used as a typical example. These phosphorous acid compounds are known per se and can be easily obtained. Particularly in the present invention, phosphorous acid trithioalcohol compounds are preferred from the viewpoint of rust prevention. The amount of the phosphorous acid compound used is 3 to 100 parts by weight, particularly preferably 5 parts by weight, per 100 parts by weight of the modified resin.
~25 parts by weight is suitable. If the amount of the phosphorous acid compound used is less than the above range, the above-mentioned effects cannot be expected, and if it is too much, the water resistance of the coating film will be extremely poor, which is not preferable. In the present invention, by blending the above-mentioned phosphorous acid compound, even if the modified resin base component and the aluminum pigment component are mixed in advance, the reaction between them during storage can be prevented, and therefore the chelate reaction of the modified resin can be prevented. In addition, aluminum pigments are stable and do not lose their leafing properties even after being stored for long periods of time, and there is no need for the harsh surface treatment required for conventional epoxy resin paints, resulting in good adhesion. , a coating film with excellent yellowing resistance etc. can be obtained. Suitable solvents used in the present invention include hydrocarbon solvents which are non-polar solvents such as toluene, xylene, benzene and naphtha. In addition,
When using polar solvents such as ketone solvents,
Since the polar solvent reacts with the aluminum paste and the phosphorous acid compound, it is necessary to mix the polar solvent with the curing agent component, for example, when these are mixed in advance with the main component and stored for a long period of time. The amount of solvent used is based on 100 parts by weight of modified resin.
10 to 70 parts by weight is suitable. Note that when the phosphorous acid compound is used in a large amount within the above range, it is not necessarily necessary to add a solvent. Furthermore, in the present invention, as described above, antirust pigments and extender pigments can be used as necessary. The appropriate amount of these rust preventive pigments and extender pigments to be used is 200 parts by weight or less per 100 parts by weight of the modified resin. The present invention will be explained in detail below using examples. In the examples, "parts" and "%" are expressed on a weight basis. Example 1 100 parts of bisphenol F type epoxy resin (Epicron #830 [manufactured by Dainippon Ink & Chemicals Co., Ltd.]; epoxy equivalent: 180) and 8 parts of orthophosphoric acid were subjected to a condensation reaction at 80°C for 5 hours to obtain a modified resin (). . After kneading 25 parts of leafing type aluminum paste pigment (Aluminum Paste 53-119 [manufactured by Toyo Aluminum Co., Ltd.]), 10 parts of trithiotrilauryl phosphite, and 5 parts of xylene in a disper, 50 parts of the modified resin () 1 part, 5 parts of xylene, and 5 parts of anti-sagging agent were mixed and kneaded in a disper to obtain a main ingredient. Separately, modified polyamide resin (ADEKA HARDENER)
Knead 30 parts of EHX-6302 (manufactured by Asahi Denka Kogyo Co., Ltd.), 35 parts of calcium carbonate, 23 parts of mica, 5 parts of xylene, 5 parts of methyl isobutyl ketone, 4 parts of anti-sagging agent and 1 part of suspending agent in a disper. It was used as a curing agent component. A paint was prepared by mixing the base agent component and the curing agent component at a ratio of (1:1). Example 2 A paint was prepared in the same manner as in Example 1 except that trithiotristearyl phosphite was used instead of trithiotrilauryl phosphite. Example 3 A paint was prepared in the same manner as in Example 1 except that trithiotricapryl phosphite was used instead of trithiotrilauryl phosphite. Example 4 A paint was prepared in the same manner as in Example 1 except that trithiotrilinolenyl phosphite was used instead of trithiotrilauryl phosphite. Example 5 A paint was prepared in the same manner as in Example 1 except that triphenyl phosphite was used instead of trithiotrilauryl phosphite. Example 6 Bisphenol A type epoxy resin (Epicote #828 [manufactured by Ciel Chemical Co., Ltd.]; epoxy equivalent 190) 100
and 10 parts of monoethyl phosphate were subjected to a condensation reaction at 90°C for 3 hours to obtain a modified resin (2). Leafing type aluminum paste pigment
After pre-kneading 20 parts of trithiolauryl phosphite, 10 parts of trithiolauryl phosphite and 4 parts of xylene in a disper, 60 parts of the modified resin (), 3 parts of xylene and 3 parts of anti-sagging agent were mixed and kneaded in a disper. These were combined to form the main ingredient. Separately, 20 parts of polyamide amine (Tomide 255 [manufactured by Fuji Kasei Kogyo Co., Ltd.]), 35 parts of calcium carbonate, 10 parts of mica, 15 parts of xylene, 15 parts of methyl ethyl ketone.
1 part, 4 parts of anti-sag agent, and 1 part of suspending agent were kneaded in a disper to obtain a curing agent component. A paint was prepared by mixing the base agent component and the curing agent component at a ratio of (1:1). Example 7 A paint was prepared in the same manner as in Example 6 except that tricresyl phosphite was used instead of trithiolauryl phosphite. Example 8 100 parts of bisphenol F type epoxy resin (Epicron #830 [manufactured by Dainippon Ink & Chemicals Co., Ltd.]; epoxy equivalent: 180) and 17 parts of dibasic potassium phosphate were heated at 110°C.
A condensation reaction was carried out for 4 hours to obtain a modified resin (2). Leafing type aluminum paste 25
After pre-kneading 10 parts of trithiotrilauryl phosphite and 5 parts of xylene in a disper, 50 parts of the modified resin (), 5 parts of xylene and 5 parts of anti-sagging agent were mixed and kneaded in a disper. It was used as the main ingredient. Separately, modified polyamide resin (ADEKA HARDENER)
Knead 20 parts of EHX-6302 [manufactured by Asahi Denka Kogyo Co., Ltd.], 35 parts of calcium carbonate, 23 parts of mica, 5 parts of xylene, 5 parts of methyl isobutyl ketone, 4 parts of anti-sag agent, and 1 part of suspending agent in a disper. It was used as a curing agent component. A paint was prepared by mixing the base agent component and the curing agent component at a ratio of (1:1). Example 9 Implemented except that a compound represented by the general formula (C ₁₂ H ₂₅ -S-) ₂ POC ₁₂ H ₂₅ (JPS212-D [manufactured by Johoku Kagaku Kogyo Co., Ltd.]) was used instead of trithiotrilauryl phosphite. A paint was prepared in the same manner as in Example 8. Comparative Example 1 A paint was prepared in the same manner as in Example 1 except that petroleum resin was used instead of trithiotrilauryl phosphite. Comparative Example 2 A paint was prepared in the same manner as in Example 1, except that bisphenol F type epoxy resin (Epicron #830) (epoxy equivalent: 180) was used instead of the modified resin ( ) in the main component of Example 1. Comparative Example 3 In the main component of Example 1, bisphenol F type epoxy resin (Epicron #830) was used instead of the modified resin (), and 15 parts of xylene was used instead of 10 parts of trithiotrilauryl phosphite and 5 parts of xylene. A paint was prepared in the same manner as in Example 1, except that After storing the base ingredients prepared in Examples 1 to 9 and Comparative Examples 1 to 3 for a certain period of time, mixing with a curing agent component,
This paint was applied to a steel plate with a brush to a dry film thickness of approximately 100 μm, and leafing properties were visually evaluated after air drying for one week. The results are shown in Table 1. In addition, the paints prepared in Examples 1 to 9 and Comparative Examples 1 to 3 were applied to a sandplast iron plate (SIS.Sa2・1/2) and a rusted iron plate (Type 2 Keren) with a brush to determine the dry film thickness.
It was applied to a thickness of 100 μm, allowed to air dry for one week, then cross-cut, and subjected to a salt spray test (1200 hours) and an outdoor exposure test (2 years). The results are shown in Table 2.

[Table] Good feeling, almost no

【table】

[Table] As is clear from Tables 1 and 2, the paint of the present invention provided a coating film with good leafing properties and a good metallic feel even after long-term storage, and also had excellent rust prevention properties. On the other hand, in Comparative Examples 1 and 3, which did not contain a phosphorous acid compound, the paint films after long-term storage had poor metallic feel and poor rust prevention properties. Furthermore, in Comparative Example 2, which used an ordinary unmodified epoxy resin, the metallic feel was good, but the rust prevention property was poor.

Claims (1)

[Scope of Claims] 1. Phosphoric acids having at least one P—OH bond, which are phosphorus oxygen acids, esters or salts thereof, and epoxy resins are added to the phosphoric acids per equivalent of the epoxy group in the epoxy resin. The hydroxyl group is 0.05~
Modified resin obtained by reacting at a ratio of 0.5 equivalent
(i), hardening material (ii), leafing type aluminum pigment (iii), and (a) general formula P-(S-CnH _2o+1 ) ₃ , P-(S-CnH _2o - ₁ ) ₃ , P
―(S―CnH _2o ― ₃ ) ₃ , or P―(S―CnH _2o ― ₅ )
₃ [However, it is an integer of 26 or less] Phosphite trithioalcohol compound or one of the thioalcohol groups in the above general formula
Compounds (iv) in which ~2 atoms are substituted with phenol, thiophenol aliphatic alcohol, polyhydric alcohol, or derivatives thereof, or (b) triphenyl phosphite or a part of the hydrogen atoms of the phenyl group of triphenyl phosphite An epoxy resin coating composition comprising a compound (iv) substituted with an alkyl group.