JPH0245664B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel metal corrosion-preventing coating. More specifically, certain chelate-reactive epoxy resins, activators, organic hardeners, bituminous materials and/or
or its substitute. A coating composition that has excellent adhesion and corrosion resistance for not only rust-free steel plates and rust-free steel plates, but also rusted steel plates, steel plates with insufficient surface treatment, galvanized steel plates, aluminum, stainless steel, etc. It is about things. Conventional epoxy resin paints are used as metal protective paints in a wide range of fields because of their excellent corrosion resistance. However, in order to maintain its excellent corrosion resistance, it is necessary to carefully remove rust from the surface of the steel plate and thoroughly prepare the surface. If the coating is applied without sufficient surface treatment, poor adhesion will occur and the corrosion resistance will be significantly reduced. Therefore, it would be of great benefit if a coating film with good adhesion and excellent corrosion resistance could be obtained by simplifying the surface treatment of the steel plate or by coating it on a rusted steel plate. The purpose of the present invention is not only to produce rust-free steel plates and derusted steel plates, but also to simplify the surface treatment of steel plates, or even when directly painted on rusted steel plates.
The object of the present invention is to provide a coating resin composition having excellent adhesion and corrosion resistance. The composition of the present invention has as an essential component (A) at least one P-OH bond of one or more types selected from orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, and phosphinic acid. (B) an active organic curing agent for epoxy resin; (C) Contains bituminous substances and/or their substitutes. The precondensate, which is an essential component of the composition of the present invention, is a mixture of an epoxy resin, phosphoric acids, hydroxyl group-containing phosphate esters, or salts thereof, etc. in the presence of a solvent in such a proportion that the epoxy groups remain. Alternatively, it can be obtained by heat treatment in its absence. The heating temperature is not particularly limited, but it is preferably 50 to 130°C in order to prevent decomposition of the epoxy resin and to complete the reaction in an appropriate time. The epoxy resin used here has the formula (Z is H, CH ₃ , C ₂ H ₅ group) Various products such as those having more than one substituted or unsubstituted glycidyl ether group in the molecule, such as diglycidyl ether of bisphenol A, bisphenol A, etc. Diglycidyl ether of phenol F, phenol novolak epoxy resin, diglycidyl ether of alkylene oxide adducts of bisphenols, etc. can be used, and the epoxy equivalent is not particularly limited, but preferably epoxy equivalent is 200 to 1000. Something of a certain degree is good. At least one P-OH used in the present invention
Examples of the phosphorus acid having a bond include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, and phosphinic acid, with orthophosphoric acid being particularly preferred. Examples of phosphorus acid esters include the above-mentioned phosphorus acid esters, preferably alkyl esters having up to about 8 carbon atoms (those having one or more hydroxyl groups) and hydroxyalkyl esters, such as:
Examples include those having groups such as ethyl, n-butyl, 2-ethylhexyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, hydroxypentyl, etc. Mono- or di-phosphate esters of n-butyl or 2-ethylhexyl are particularly preferred. Examples of phosphorus acid salts include the above-mentioned phosphorus acid salts, such as potassium, sodium, lithium, calcium, zinc, aluminum, tin, barium, etc. salts, particularly potassium, sodium, or calcium salts. Secondary phosphates are preferred. The reaction between epoxy resin and phosphoric acids is that the hydroxyl group of phosphoric acid is
It is preferable to carry out at a ratio of 0.05 to 0.9 equivalent, preferably 0.05 to 0.4 equivalent, and the epoxy equivalent of the produced modified epoxy resin (precondensate) is preferably 3000 or less. The active organic curing agent used in the present invention includes:
All curing agents commonly used for epoxy resin coatings can be used, including aliphatic polyamines, aromatic modified polyamines, aliphatic modified polyamines, polyamides, amino resins, carboxylic acids, and the like. As the bituminous substance used in the composition of the present invention, coal tar, coal tar pitch, various types of cutback tar, swelling charcoal, asphalt, etc. can be used. There are various alternatives to bituminous substances, such as aromatic oil resins, coumaron resins, petroleum resins, and substances commonly used as diluents.
DOP, DBP, and other high-boiling point neutral oils such as petroleum-based and coal-based oils can be used. The proportion of bituminous substances and/or substitutes for bituminous substances is based on the precondensate.
0.5 to 2 times the amount is appropriate. Incidentally, various curing catalysts, fillers, diluents, dehydrating agents, resins, etc. can be added to the composition of the present invention as required. The coating composition of the present invention can be dried naturally to form a coating film, but if necessary, the desired coating film can also be obtained by forced drying by heating or the like. The effect of the present invention is to provide a coating resin composition that can be applied directly to steel plates that are difficult to coat, such as rust-faced steel plates or steel plates with a simple surface treatment, to obtain a coating film with excellent adhesion and corrosion resistance. There is a particular thing. Hereinafter, the present invention will be explained in more detail with reference to Examples.
Note that parts in the examples are based on weight. Example 1 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) and adeca glycilol
20 parts of ED-501 (epoxy equivalent = 300), 6 parts of orthophosphoric acid, and 50 parts of xylene were mixed and reacted at 80°C for 5 hours to obtain a precondensate. The obtained precondensate is referred to as []. For 100 parts of precondensate,
As an epoxy resin curing agent, 12 parts of polyamide (amine value = 340), bituminous material, solvent, and filler are blended as shown in Table 1, and this blended resin is applied to a rusted steel plate (baked outdoors for one year to prevent floating rust). dropped steel plate)
The film was applied to a film thickness of 150 μm, and after curing at room temperature for one week, a comparative test of film performance as shown in Table 1 was carried out. As a result, both adhesion and corrosion resistance were significantly superior to the comparative example. Example 2 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 480), 20 parts of diglycidyl ether of bisphenol A propylene oxide adduct (epoxy equivalent = 340), 8 parts of monoethyl phosphate, and 50 parts of xylene. The mixture was stirred and reacted at 85°C for 4 hours to obtain a precondensate. The obtained precondensate is referred to as []. Adeka hardener EH-541S (amine value =
280, Asahi Denka Kogyo Co., Ltd. product name) 12 copies and bituminous materials,
The solvent and filler were mixed as shown in Table 1, and a coated board was prepared in the same manner as in Example 1 using this blended resin. As a result of comparing the coating film performance, as shown in Table 1, Both adhesion and corrosion resistance were extremely excellent. Example 3 100 parts of bisphenol novolac epoxy resin (epoxy equivalent = 180), 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 550), 50 parts of xylene, 25 parts of methyl ethyl ketone, and 2.
The mixture was mixed with 30 parts of potassium phosphate and reacted with stirring at 110°C for 5 hours to obtain a precondensate. The obtained precondensate is referred to as []. Modified polyamide deca hardener EH-220 (amine value = 375,
Asahi Denka Kogyo Co., Ltd. product name) 15 parts, bituminous material, solvent,
The fillers were blended as shown in Table 1, and a coated plate was prepared in the same manner as in Example 1 using this blended resin, and the coating film performance was compared. , and had excellent corrosion resistance. Comparative Example 1 100 parts of unmodified bisphenol A diglycidyl ether (epoxy equivalent = 380), 25 parts of polyamide (amine value = 340), bituminous material, solvent,
Fillers were blended as shown in Table 1, and this blended resin was applied to a rusted steel plate (a steel plate that had been exposed outdoors for 41 years to remove loose rust), and cured at room temperature for one week to a film thickness of 150 μm. Table 1 shows the coating film performance test results. Comparative Example 2 To 100 parts of unmodified bisphenol F diglycidyl ether (epoxy equivalent = 480), 25 parts of Adeka Hardener EH-541S, bituminous material, solvent,
Fillers were blended as shown in Table 1 and Comparative Example 1
A coated plate was created by applying it to a rusted steel plate in the same manner as above. Table 1 shows the coating film performance test results. Comparative Example 3 50 parts of bisphenol volak epoxy resin (epoxy equivalent = 180) and 50 parts of bisphenol A diglycidyl ether (epoxy equivalent = 550), 26 parts of Adeka Hardener EH-220, bituminous material, and solvent Fillers were mixed as shown in Table 1 and applied to a rusted steel plate in the same manner as in Comparative Example 1 to prepare a coated plate. Table 1 shows the coating film performance test results.

【table】

[Table] Example 4 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Example 1 except that white tar, a bituminous substance substitute, was used in place of the coal tar in Example 1, and the coating film was Performance tests were conducted. The results are shown in Table 2. Example 5 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Example 2 except that white tar was used in place of the coal tar in Example 2, and a coating film performance test was conducted on the resin composition. The results are shown in Table 2. Example 6 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Example 3 except that white tar was used in place of the coal tar in Example 3, and its coating film performance test was conducted. The results are shown in Table 2. Comparative Example 4 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Comparative Example 1 except that white tar was used in place of the coal tar in Comparative Example 1, and its coating film performance test was conducted. The results are shown in Table 2. Comparative Example 5 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Comparative Example 2 except that white tar was used instead of the coal tar in Comparative Example 2, and a coating film performance test was conducted on the resin composition. The results are shown in Table 2. Comparative Example 6 A resin composition having the formulation shown in Table 2 was obtained in the same manner as in Comparative Example 3, except that white tar was used instead of the coal tar in Comparative Example 3, and a coating film performance test was conducted on the resin composition. The results are shown in Table 2.

[Table] Example 7 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) and 23 parts of sodium pyrophosphate
1 part and 50 parts of xylene were mixed and reacted at 80°C for 5 hours to obtain a precondensate (epoxy equivalent =
755). 15 parts of polyamide (amine value = 340) as an epoxy resin curing agent per 100 parts of precondensate,
50 parts coal tar, 25 parts methyl isobutyl ketone
Example 1
The coating performance was investigated in the same manner as above. The results are shown in Table 3. Example 8 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 480), 5 parts of phosphorous acid, and 50 parts of xylene were mixed and reacted at 80°C for 5 hours to obtain a precondensate (epoxy equivalent weight = 755). Adeka hardener EH-541S (amine value =
280, Asahi Denka Kogyo Co., Ltd. (trade name) 8 parts, coal tar 50 parts, methyl isobutyl ketone 25 parts, talc 50 parts
1 part and 1 part of silica were added, and the coating film performance was examined in the same manner as in Example 1. The results are shown in Table 3. Example 9 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) and adecacrisilol
20 parts of ED-501 (epoxy equivalent = 300, trade name manufactured by Asahi Denka Kogyo Co., Ltd.), 2 parts of polyphosphoric acid, and 50 parts of xylene were mixed and reacted at 80°C for 5 hours to form a precondensate []
was obtained (epoxy equivalent = 850). 15 parts of polyamide (amine value = 340) as an epoxy resin curing agent per 100 parts of precondensate,
50 parts coal tar, 25 parts methyl isobutyl ketone
Example 1
The coating performance was investigated in the same manner. The results are shown in Table 3. Example 10 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 480) and adecacrisilol
Mix 20 parts of ED-501 (epoxy equivalent = 300, trade name manufactured by Asahi Denka Kogyo Co., Ltd.) with 3 parts of phosphonic acid and 50 parts of xylene, and react at 80°C for 5 hours to obtain a precondensate []
was obtained (epoxy equivalent = 770). 17 parts of polyamide (amine value = 340) as an epoxy resin curing agent per 100 parts of precondensate,
50 parts coal tar, 25 parts methyl isobutyl ketone
Example 1
The coating performance was investigated in the same manner. The results are shown in Table 3. Example 11 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) was mixed with 9 parts of phosphinic acid and 50 parts of xylene, and reacted at 80°C for 5 hours to obtain a precondensate [] (epoxy equivalent: =710). 18 parts of polyamide (amine value = 340) as an epoxy resin curing agent per 100 parts of precondensate,
50 parts coal tar, 25 parts methyl isobutyl ketone
Example 1
The coating performance was investigated in the same manner. The results are shown in Table 3. Comparative Example 7 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) and adeca glycilol
20 parts of ED-501 (epoxy equivalent = 300, trade name manufactured by Asahi Denka Kogyo Co., Ltd.), 37.5 parts of 2-ethylhexyl phosphate (acid equivalent = 150), and 50 parts of xylene were mixed and reacted at 60°C for 15 hours. to obtain a precondensate [ ]. 100 parts of precondensate [] 40 parts of amino resin Cymel 303 manufactured by American Cyaminado, 50 parts of coal tar, 25 parts of methyl isobutyl ketone, talc
50 parts and 1 part of silica were added, and the coating performance was examined in the same manner as in Example 1. The results are shown in Table 3. Comparative Example 8 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 380) was mixed with 3 parts of 1-hydroxyethane-1,1-diphosphoric acid and reacted at 80°C for 5 hours to form a precondensate []. Obtained. Add 23 parts of polyamide (amine value = 340) as an epoxy resin curing agent, 50 parts of coal tar, 25 parts of methyl isobutyl ketone, 50 parts of talc, and 1 part of silica to 100 parts of the precondensate, and proceed in the same manner as in Example 1. The coating performance was investigated. The results are shown in Table 3.

【table】

【table】

Claims (1)

[Claims] 1. As an essential component (A) at least one P-OH bond of one or more types selected from orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, and phosphinic acid. (B) an active organic curing agent for epoxy resin; and (C) a bituminous substance and/or its substitute.