JPH0556786B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a coating resin composition. More specifically, by combining a specific chelate-reactive polyol resin and an amino resin curing agent,
The present invention relates to a coating resin composition that is used to form a heat-curable coating film and has excellent mechanical properties, particularly adhesion, bending processability, and corrosion resistance. In particular, the present invention has excellent mechanical properties, especially adhesion, bending workability, The present invention relates to a coating resin composition that provides corrosion resistance. [Prior Art and Problems] Conventionally, low molecular weight epoxy resins obtained from divalent phenols, particularly 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) and epichlorohydrin, have been used as coating resin compositions. A high molecular weight epoxy resin is obtained by further reacting the epoxy resin with dihydric phenol, and this is then heat-cured with a curing agent mainly composed of an amino resin, which is generally used. However, those based on high molecular weight epoxy resins as described above have insufficient solubility in organic solvents and have the drawback that the cured product has poor flexibility, which has greatly restricted their use. or,
Conventional polyol resins do not have sufficient adhesion and corrosion resistance to be used as metal protective coatings, and require sufficient surface treatment in order to exhibit satisfactory performance. If the coating is applied without sufficient surface treatment, poor adhesion will occur and the corrosion resistance will be significantly reduced. Therefore, the object of the present invention is to use a chelate-reactive polyol to provide a steel sheet that does not have the above-mentioned drawbacks and has a simplified surface treatment, or for aluminum, zinc steel sheets, stainless steel sheets, etc. that have conventionally had poor adhesion. Another object of the present invention is to provide a coating resin composition having excellent adhesion and corrosion resistance. [Means for Solving the Problems] That is, the present invention provides a substituted or unsubstituted glycidyl ether of an alkylene oxide adduct of a dihydric phenol, a phosphorus acid having at least one P-OH bond, an ester or salt thereof, Polyol resin (A) obtained by reacting the precondensate obtained from the reaction with dihydric phenol to obtain a high molecular weight epoxy resin, which is further reacted with a compound containing an amino group that is reactive with an epoxy group. and urea,
The present invention relates to a coating resin composition characterized by containing a curing agent mainly composed of an amino resin (B) such as melamine or guanamine resin. The divalent phenols used in the present invention include mononuclear and/or polynuclear divalent phenols. Examples of such mononuclear divalent phenols include resorcinol, hydroquinone, pyrocatechol, phloroglucinol, 1,5-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and the like. In addition, as an example of polynuclear divalent phenol, the general formula: (In the formula, Ar is an aromatic divalent hydrocarbon such as a naphthylene group and a phenylene group, and a phenylene group is preferable for the purpose of the present invention. Y′ and Y ₁ may be the same or different, and a methyl group, n -propyl group, n-
Alkyl groups, preferably with up to 4 carbon atoms, such as butyl, n-hexyl, n-octyl, or halogen atoms, i.e. chlorine, bromine, iodine or fluorine, or methoxy, methoxymethyl Alkoxy groups, such as ethoxy, ethoxyethyl, n-butoxy, amyloxy, are preferably alkoxy groups having up to 4 carbon atoms. When a substituent other than a hydrogen group is present on either or both of the above-mentioned aromatic divalent hydrocarbon groups, these substituents may be the same or different. m and z are integers having values ranging from 0 (zero) to the maximum value corresponding to the number of hydrogen atoms in the aromatic ring (Ar) that can be substituted with a substituent, and can be the same or different values. R ₁ is for example

[Formula] -O-, -S-, -SO-, -SO ₂ -, or an alkylene group such as methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, 2-ethylhexamethylene group octamethylene, nonamethylene, decamethylene or alkylidene groups such as ethylidene, propylidene, isopropylidene, isobutylidene, amylidene, isoamylidene, 1-phenylethylidene or cycloaliphatic groups such as 1,4- cyclohexylene group,
1,3-cyclohexylene group, cyclohexylidene group, halogenated alkylene group, halogenated alkylidene group, halogenated cycloaliphatic group, alkoxy- and aryloxy-substituted alkylidene group, or alkoxy-substituted alkylidene group and aryloxy-substituted alkylene groups or alkoxy- and aryloxy-substituted cycloaliphatic groups such as methoxymethylene, ethoxymethylene, ethoxyethylene, 2-ethoxytrimethylene, 3-ethoxypentamethylene, 1,4-(2-methoxycyclohexane) group, phenoxyethylene group, 2-phenoxytrimethylene group, 1,3-(2-phenoxycyclohexane) group or alkylene group such as phenylethylene group, 2- phenyltrimethylene group, 1-phenylpentamethylene group, 2-phenyldecamethylene group or aromatic group such as phenylene group, naphthylene group or halogenated aromatic group such as 1,4-(2-chlorophenylene) group,
1,4-(2-bromphenylene) group, 1,4-
(2-fluorophenylene) group or alkoxy- and aryloxy-substituted aromatic groups such as 1,4-(2-methoxyphenylene) group, 1,4
-(2-ethoxyphenylene) group, 1,4-(2-
n-propoxyphenylene) group, 1,4-(2-
phenoxyphenylene) group or an alkyl-substituted aromatic group such as 1,4-(2-methylphenylene) group, 1,4-(2-ethylphenylene) group,
1,4-(2-n-propylphenylene) group, 1,
4-(2-n-butylphenylene) group, 1,4-
It is a divalent group such as a divalent hydrocarbon group such as (2-n-dodecylphenylene) group, or R ₁
For example, the expression It can also be a ring fused to one of the Ar groups, as in the case of the compound represented by R ₁
can also be a polyalkoxy group, such as a polyethoxy group, a polypropoxy group, a polythioethoxy group, a polybutoxy group, a polyphenylethoxy group, or R ₁ can be, for example, a polydimethylsiloxy group,
It can be a group containing a silicon atom, such as a polydiphenylsiloxy group, a polymethylphenylsiloxy group, or R ₁ can be an aromatic ring, a tertiary-amino group, an ether bond, a carbonyl group, or a sulfur or sulfoxide group. 2 separated by a sulfur-containing bond
There are polynuclear dihydric phenols, which can be one or more alkylene or alkylidene groups. Particularly preferred among such polynuclear divalent phenols is the general formula (In the formula, Y' and Y ₁ have the same meanings as above, m and z have values of 0 to 4, and R ₁ preferably has a value of 1 to 3.
alkylene or alkylidene group or formula with 5 carbon atoms

【formula】

【formula】 or

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
Note that parts in the examples are based on weight. Production example 1 150 parts of liquid epoxy resin (epoxy equivalent = 410) obtained by adding ethylene oxide to bisphenol A and converting it into glycidyl ether and monoethyl phosphate
The precondensate obtained by mixing 10 parts and stirring at 90°C for 4 hours is referred to as []. Sodium hydroxide was added as a catalyst to 20 parts of bisphenol A to 200 parts of the precondensate, and the mixture was heated and stirred at 200°C for 6 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 2,700. Furthermore, 9 parts of diethanolamine was added, and the mixture was stirred at 100°C for 3 hours to obtain a polyol resin (2). The polyol resin had a hydroxyl equivalent of 360 and was easily soluble in aromatic solvents such as xylene and toluene. Production Example 2 150 parts of a liquid epoxy resin (epoxy equivalent = 300) obtained by adding propylene oxide to bisphenol F and converting it into glycidyl ether were mixed with 15 parts of dibasic potassium phosphate, and the reaction was stirred at 100°C for 6 hours. The precondensate obtained is referred to as []. Add dimethylamine as a catalyst to 50 parts of bisphenol F to 300 parts of precondensate,
Heating and stirring was continued at 150°C for 8 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 1300. Further, 35 parts of dibutylamine was added and stirred at 100°C for 3 hours to obtain a polyol resin (2). The hydroxyl equivalent of the polyol resin is 490,
It was easily soluble in aromatic solvents such as xylene and toluene. Production example 3 200 parts of liquid epoxy resin (epoxy equivalent = 520) obtained by adding propylene oxide to bisphenol A and converting it into glycidyl ether and orthophosphoric acid 6
The precondensate obtained was mixed and reacted with stirring at 80°C for 5 hours. Precondensation []
Potassium hydroxide was added as a catalyst to 14 parts of bisphenol F per 200 parts, and the mixture was heated and stirred at 180°C for 6 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 3,800. Furthermore, 8 parts of diisopropanolamine was added and stirred at 100°C for 3 hours to obtain a polyol resin (2). The polyol resin had a hydroxyl equivalent of 450 and was easily soluble in aromatic solvents such as xylene and toluene. Production Example 4 Sodium hydroxide was added as a catalyst to 150 parts of bisphenol A digyl cidyl ether (epoxy equivalent = 480) and 27 parts of bisphenol A, and the mixture was heated and stirred at 180°C for 5 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 2,700. Further, 25 parts of xylene, 25 parts of methyl isobutyl ketone and 8 parts of diethanolamine were added and stirred at 90°C for 3 hours to obtain a polyol resin (2). The hydroxyl equivalent of the polyol resin () is 300, and cannot be dissolved in an aromatic solvent such as xylene or toluene alone, so it is necessary to add a ketone solvent or an alcohol solvent. Production Example 5 150 parts of bisphenol F diglycyl ether (epoxy equivalent = 190) obtained from bisphenol F and epichlorohyridone and bisphenol
Add dimethylamine as a catalyst to 70 parts of F to 150
The mixture was heated and stirred at ℃ for 15 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 2,300. Furthermore, 20 parts of xylene, 20 parts of ethyl isobutyl ketone, and 12 parts of dibutylamine were added, and the mixture was heated and stirred at 100°C for 3 hours to obtain a polyol resin (2). The hydroxyl equivalent of the polyol resin is
290, and cannot be dissolved in aromatic solvents such as xylene or toluene alone, so it is necessary to add a ketone solvent or alcohol solvent. Production Example 6 200 parts of liquid epoxy resin (epoxy equivalent = 520) obtained by adding propylene oxide to bisphenol A and converting it into glycidyl ether and bisphenol
Add potassium hydroxide as a catalyst to 2 parts of F3 to 180
The mixture was heated and stirred at ℃ for 6 hours. The obtained high molecular weight epoxy resin had an epoxy equivalent weight of 3,700. Furthermore, 7 parts of diisopropanolamine was added and stirred at 100°C for 3 hours to obtain a polyol resin (2). The polyol resin had a hydroxyl equivalent of 450 and was easily soluble in aromatic solvents such as xylene and toluene. Examples 1 to 3, Comparative Examples 1 to 3 Polyol resin () obtained in the above production example
A coating resin composition having the composition shown in Table 1 was prepared using ~() and cured under predetermined baking conditions. Thereafter, the physical properties of the coating film were tested. The results are shown in Table-1.

[Table] **Product name: Hitachi Chemical urea resin Baking conditions: Untreated cold-rolled steel sheet, film thickness 10-12μ, 20
0°C x 5 minutes [Effects] The present invention provides excellent mechanical properties, especially adhesion, bending workability, and corrosion resistance to steel plates, etc., without any surface treatment, and is soluble in organic solvents. A coating resin composition with good properties can be obtained.

Claims (1)

[Claims] 1 Substituted or unsubstituted glycidyl etherified product of alkylene oxide adduct of dihydric phenol and P
A precondensate obtained from the reaction of phosphorus having at least one -OH bond with an acid, its ester or salt is reacted with dihydric phenol to obtain a high molecular weight epoxy resin, which is further made reactive with epoxy groups. 1. A resin composition for coating, comprising a polyol resin (A) obtained by reacting with a compound containing an amino group, and a curing agent mainly composed of an amino resin (B).