JPH09272839A - Coating material resin composition for can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in acid resistance, adhesiveness and processability, suitable for a metallic can for a hair dyeing chemical, comprising a polyester resin containing an imide bond in a molecular chain and a polyimide resin containing a specific diamine compound as essential components. SOLUTION: This coating material resin composition for a can is obtained by blending (A) 100 pts.wt. of a polyester resin containing an imide bond in a molecular chain with (B) 5-50 pts.wt. of a polyimide resin of formula I (R<1> is a tetrafunctional organic acid residue; R<2> is a bifunctional diamine residue; (n) is an integer of >=1), in which 50-100mol% of the total diamine components constituting the R<2> is a diamine compound of formula II [X is CH2 , O, S02 , C(CH3 )2 or C(CF3 )2 ], as essential components.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is suitable for coating metal cans for hair dyeing chemicals and chlorine-based detergents.
The present invention relates to a coating resin composition for a can, which has excellent acid resistance, adhesion, and workability.

[0002]

2. Description of the Related Art Polyvinyl chloride resins and epoxyphenolic resins are often used in paints for the inner surface of cans, but polyvinyl chloride resins have insufficient adhesion to the metal that is the material of the can. Therefore, it is necessary to coat the surface treated with epoxy resin or the like, which has a drawback that the coating process is complicated.

Further, as the tendency of can contents to become mousses becomes stronger, there is an increasing demand for metal cans for containers for containing contents with high acidity such as hair dyeing agents and chlorine detergents. ing. Epoxyphenol resins, polyamideimide resins, or polyester resins have been investigated in such fields requiring acid resistance. However, the epoxyphenol-based resin and the polyamide-imide resin have a drawback that peeling and coating cracking occur during bending such as necking, and the polyester-based resin does not have sufficient acid resistance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and has excellent adhesion to metals, acid resistance, bending workability, hair dyeing agents and chlorine-based detergents. The present invention aims to provide a can coating resin composition suitable for.

[0005]

Means for Solving the Problems As a result of diligent research aimed at achieving the above object, the present inventor has found that the above object can be achieved by using a resin composition described later, and has completed the present invention. It was done.

That is, the present invention will be described in detail below. (A) a polyester resin having an imide bond in the molecular chain and (B) a polyimide resin represented by the following general formula,

[0007]

Embedded image (However, in the formula, R ¹ represents a tetravalent organic acid residue, R ² represents a divalent diamine residue, and n represents an integer of 1 or more.) R
50 to 100 mol% of all diamine components constituting ² is a diamine compound represented by the following general formula

[0008]

Embedded image (However, in the formula, x represents —CH ₂ —, —O—, SO ₂ —,
_{-C (CH 3) 2 -,} - C (CF 3) 2 - a representative) and the essential components, with respect to 100 parts by weight of polyester resin (A), polyimide resin 5-50 parts by weight of (B) A paint resin composition for a can, which is characterized in that:

The polyester resin (A) used in the present invention is not particularly limited as long as it is a polyester resin having an imide bond in the molecular chain. For example, it can be obtained by using an imide acid represented by the following general formula.

[0010]

Embedded image (However, R ³ represents a divalent organic group.) The imide acid represented by the general formula 5 can be obtained, for example, by reacting 2 mol of trimellitic anhydride with 1 mol of diamine or diisocyanate. Examples of the diamine used at this time include aromatic diamines such as 4,4′-diaminodiphenylmethane, p-phenylenediamine and m-phenylenediamine, and aliphatic diamines such as hexamethylenediamine. From the viewpoint, aromatic diamines are preferable. The diisocyanate is not particularly limited, and aromatic diisocyanates such as 4,4 '
-Diphenylmethane diisocyanate, toluidine isocyanate and the like are preferable. The method for producing the imidic acid is not particularly limited, but for example, the reaction of diamine and trimellitic anhydride is carried out at a temperature of 120 to 250 ° C in the presence of a polar solvent such as cresol, phenol, N-methylpyrrolidone.
The formation of imide can be confirmed by the outflow of water generated during the formation of imide acid. From the viewpoint of acid resistance and processability, the amount of imide acid used is preferably 10 to 60 equivalent% of the total acid content. Usage 10
If it is less than 1 equivalent%, the acid resistance is poor, and if it exceeds 60 equivalent%, the coating film becomes hard and the workability is poor, which is not preferable.

Examples of the acid component of the polyester resin having an imide bond in the molecular chain include terephthalic acid, isophthalic acid or derivatives thereof such as dimethylterephthalic acid and dimethylisophthalic acid, in addition to the above imide acid. As the alcohol component, divalent or higher alcohol,
For example, ethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 1,6-
Cyclohexane dimethanol and the like. Also, 3
Examples of the hydric alcohol include glycerin, trimethylolpropane, pentaerythritol, and tris-2-.
Examples thereof include hydroxyethyl isocyanurate.

For the production of a polyester resin having an imide bond in the molecular chain, it is preferable that the equivalent ratio of the acid component to the alcohol component is 1 to 100 and the alcohol is in excess.
When the acid component and the alcohol component are heated and reacted, there is no particular limitation as long as the conditions are such that ester reaction and transesterification reaction are substantially caused. For example, in the presence of a trace amount of an esterification catalyst such as tetraalkyl titanate, lead acetate, dibutyltin dilaurate, etc., at 120 to 240 ° C.
At a temperature of Also, cresol according to the viscosity,
The synthesis may be carried out in the coexistence of a solvent such as phenol or N-methylpyrrolidone. In the production of polyester resin having imide bond in the molecular chain, after imide acid is synthesized, the remaining polyester components (acid component and alcohol component) are added to esterify, all components are reacted at the same time to imidize There are various synthetic methods such as a method of simultaneously performing esterification and esterification, a method of preliminarily reacting a polyester component other than the imidic acid component, and then performing imidization and esterification by adding an imidic acid component, which are not particularly limited. is not.

The (B) polyimide resin represented by the general formula of Chemical Formula 3 used in the present invention can be obtained by reacting an acid component and a diamine component. As the acid component, for example, pyromellitic acid, 1,2,3,4-benzenetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,
2,4,5-Cyclopentanetetracarboxylic acid, 1,2,4,5-Cyclohexanetetracarboxylic acid, 3,3 ', 4,4'-Bicyclohexyltetracarboxylic acid, 2,3,5-Tricarboxycyclopentyl Acetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4'- Biphenyl tetracarboxylic acid, 3,3 ', 4,4'-benzophenone tetracarboxylic acid, 2,3,3', 4'-benzophenone tetracarboxylic acid, 3,3 ', 4,4'-biphenyl ether tetracarboxylic acid (4,4′-oxydiphthalic acid), 2,3,3 ′, 4′-biphenyl ether tetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2, 3-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) methane, bis (2,3-dicarboxyphenyl) methane, 1,1-bi Su (2,3-dicarboxyphenyl) ethane,
2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 2,3,3 ′, 4′-diphenylsulfonetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,
4,5,8-Naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 3,4,9,10-tetracarboxyperylene, 2,2-bis [4- (3,4-di Examples thereof include anhydrides such as carboxyphenoxy) phenyl] propane and 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane, and lower alkyl esters thereof. These may be used alone or in combination. Can be used.

Further, as the diamine component, those represented by the general formula of the above chemical formula 4 are 50 to 100 mo of the total diamine component.
It is desirable to use 1%. The amount used is 50 mol%
If it is less than 1, the compatibility with the polyester resin is poor and coating unevenness occurs after coating and curing.

Specific diamines to be used together with the diamine of the general formula 4 include, for example, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5, 5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetraethyl
-4,4'-diaminodiphenylmethane, 3,3'-dimethyl
-5,5'-diethyl-4,4'-diaminodiphenylmethane,
4,4'-methylenebis (cyclohexylamine), 3,
3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3,3'-dimethoxy-4,4'-diaminodiphenylmethane, 3,3'-diethoxy-4,4'-diaminodiphenylmethane, bis (3-aminophenyl ) Ether, bis (4-
Aminophenyl) ether, 3,4'-diaminodiphenyl ether, 3,3'-diethyl-4,4'-diaminodiphenyl ether, 3,3'-dimethoxy-4,4'-diaminodiphenyl ether, bis [4- (4- Aminophenoxy) phenyl] ether, 3,3'-dimethyl-4,4'-diaminodiphenyl sulfone, 3,3'-diethyl-4,4'-diaminodiphenyl sulfone, 3,3'-dimethoxy-4,4 ' -Diaminodiphenyl sulfone, 3,3'-diethoxy-4,4 '
-Diaminodiphenyl sulfone, 3,3'-dimethyl-4,
4'-diaminodiphenylpropane, 3,3'-diethyl-
4,4'-diaminodiphenylpropane, 3,3'-dimethoxy-4,4'-diaminodiphenylpropane, 3,3'-diethoxy-4,4'-diaminodiphenylpropane, 2,2-bis [4- ( 4-Aminophenoxy) phenyl] propane, 1,
3-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 4,4′-diaminodiphenyl sulfide, 3,3′-dimethyl-4,4′-diaminodiphenyl sulfide, 3 3,3'-diethyl-4,4'-diaminodiphenyl sulfide, 3,3'-dimethoxy-4,4'-diaminodiphenyl sulfide, 3,3'-diethoxy-4,4 '
-Diaminodiphenyl sulfide, 2,2'-diaminodiethyl sulfide, 2,4'-diaminodiphenyl sulfide, m-phenylenediamine, p-phenylenediamine,
1,3-bis (4-aminophenoxy) benzene, 1,2-bis (4-aminophenyl) ethane, 1,1-bis (4-aminophenyl) ethane, bis (3-aminophenyl) sulfone, bis ( 4-aminophenyl) sulfone, o-toluidine sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′-diaminodibenzyl sulfoxide, Bis (4-aminophenyl) diethylsilane, bis (4-aminophenyl) diphenylsilane, bis (4-aminophenyl) ethylphosphine oxide, bis (4-aminophenyl) phenylphosphine oxide, bis (4-aminophenyl)- N-phenylamine, bis (4-aminophenyl) -N-methylamine, 1,2-diaminonaphthalene, 1,
4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-
Diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,6-diaminonaphthalene, 1,4-diamino-2-methylnaphthalene,
1,5-diamino-2-methylnaphthalene, 1,3-diamino-2-
Phenylnaphthalene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3 ′ -Dichloro-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,4′-dimethyl-4,4′-diaminobiphenyl,
3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,
4'-bis (4-aminophenoxy) biphenyl, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminotoluene, 1,3-diamino-2,5-
Dichlorobenzene, 1,4-diamino-2,5-dichlorobenzene, 1-methoxy-2,4-diaminobenzene, 1,3-diamino-4,6-dimethylbenzene, 1,4-diamino-2,5- Dimethylbenzene, 1,4-diamino-2-methoxy-5-methylbenzene, 1,4-diamino-2,3,5,6-tetramethylbenzene, 1,
4-bis (2-methoxy-4-aminopentyl) benzene, 1,
4-bis (1,1-dimethyl-5-aminopentyl) benzene,
1,4-bis (4-aminophenoxy) benzene, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, o-xylenediamine, m-xylenediamine, p-xylenediamine, 9,10-
Bis (4-aminophenyl) anthracene, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,6-diaminopyridine, 3,5-diaminopyridine, 1,
3-diaminoadamantane, 3,3'-diamino-1,1,1'-
Diadamantane, N- (3-aminophenyl) -4-aminobenzamide, 4,4'-aminobenzanilide, 4-aminophenyl-3-aminobenzoate, 2,2-bis (4-aminophenyl) hexafluoropropane 2,2-bis (3-aminophenyl) hexafluoropropane, 2- (3-aminophenyl) -2- (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] hexafluoropropane, 2,2-bis [4- (2-chloro
-4-Aminophenoxy) phenyl] hexafluoropropane, 1,1-bis (4-aminophenyl) -1-phenyl-2,
2,2-trifluoroethane, 1,1-bis [4- (4-aminophenoxy) phenyl] -1-phenyl-2,2,2-trifluoroethane, 1,3-bis (3-aminophenyl) Hexafluoropropane, 1,3-bis (3-aminophenyl) decafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-) Methylphenyl) hexafluoropropane, 2,2-bis (5-amino-4-methylphenyl) hexafluoropropane, 1,4-bis (3-aminophenyl) but-1-ene-3-
In, and the like, which may be used alone or in combination of two or more.

The polyamic acid which is the precursor of this polyimide resin is 0.5 g / N-methyl-2-pyrrolidone 10 ml
As a solution with a concentration of, the logarithmic viscosity at 30 ℃ is 0.2 to 4.0.
And more preferably 0.3 to 2.0. The polyamic acid can be obtained by subjecting an approximately equimolar amount of an acid component and a diamine component to an addition polymerization reaction in an organic solvent at a reaction temperature of 30 ° C. or lower, preferably 20 ° C. or lower for 3 to 12 hours.
As the organic solvent in this polymerization reaction, for example, N, N-
Examples thereof include dimethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone and hexamethylenephosphoamide. They can be used alone or in combination of two or more.

The can coating resin composition of the present invention contains a resin component, which is a combination of the polyester resin (A) and the polyimide resin (B), in an amount of 5 to 50% by weight of the total resin composition, and the remaining solvent. 90 to 50% by weight is desirable.

The coating resin composition for a can of the present invention contains the polyester resin (A) and the polyimide resin (B) as essential components, but as long as it does not defeat the purpose of the present invention, and if necessary. , Titanium compound, polyisocyanate generator, organic acid metal salt, alkoxy-modified amino resin, polyamide resin, polyhydantoin resin, polysulfone resin, phenol resin, amino resin, etc. in a proportion of 0.1 to 25% by weight based on the resin content. can do.
In addition, inorganic pigments such as titanium oxide and silica, curing catalysts such as p-toluene sulfonic acid, dodecylbenzene sulfonic acid, phosphoric acid and esterified products thereof, surface smoothing agents, defoaming agents, dispersants and other additives are added and blended. Can be manufactured.

[0019]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, “parts” means “parts by weight”.

Synthesis Example 1 (Synthesis of Polyesterimide Resin) 166.0 parts of terephthalic acid, 287.1 parts of tris-2-hydroxyethyl isocyanurate, 93.0 parts of ethylene glycol and 0.5 part of tetrabutyl titanate, 4 parts equipped with a thermometer and a stirrer Place in a mouth flask and allow 5 hours
The temperature was gradually raised to 230 ° C. to carry out the transesterification reaction.
Then, 158.4 parts of diaminodiphenylmethane, 307.2 parts of trimellitic anhydride and 400 parts of N-methylpyrrolidone were added, reacted at 180 ° C for 3 hours, heated to 220 ° C, and depressurized at 10 mmHg for 3 hours to carry out polymerization. went. Then, the mixture was diluted with 500 parts of N-methylpyrrolidone, and 10.1 parts of tetraisopropyl titanate was further added to obtain a polyesterimide resin. Synthetic Example 2 (Synthesis of Polyesterimide Resin) 166.0 parts of terephthalic acid, 156.6 parts of tris-2-hydroxyethyl isocyanurate, 46.0 parts of glycerin, 111.6 parts of ethylene glycol and tetrabutyl titanate.
Five parts were placed in a four-necked flask equipped with a thermometer and a stirrer, and the temperature was gradually raised to 230 ° C over 5 hours to carry out a transesterification reaction. Then diaminodiphenylmethane
After adding 258.4 parts, 307.2 parts of trimellitic anhydride and 400 parts of N-methylpyrrolidone and reacting at 180 ° C for 3 hours, the temperature was raised to 220 ° C and the pressure was reduced to 10 mmHg for 3 hours to carry out polymerization. . Then N-methylpyrrolidone 500
Parts and add tetraisopropyl titanate 9.
5 parts were added to obtain a polyesterimide resin.

Synthesis Example 3 (Synthesis of Polyamic Acid Resin) 369 parts of 2,2-bis [4- (4-aminophenoxy) phenyl] propane were attached to a thermometer, a condenser and a stirrer.
It was placed in a four-necked flask and dissolved with 2330 parts of N-methylpyrrolidone. Under a nitrogen atmosphere at room temperature, 213.6 parts of pyromellitic dianhydride was added in portions while paying attention to the increase in the dissolution temperature, and the mixture was reacted at room temperature for 12 hours to obtain a polyamic acid resin solution. A part of this polyamic acid resin solution was reprecipitated with methanol, and the obtained polyamic acid resin powder was dissolved with N-methylpyrrolidone to give 0.5 g / 100 ml.
The concentration was measured and the logarithmic viscosity at 30 ° C was measured to be 1.3 d
1 / g.

Example 1 To 100 parts of the polyesterimide resin produced in Synthesis Example 1,
20 parts of the polyamic acid resin produced in Synthesis Example 3 was added to produce a can coating resin composition.

Example 2 To 100 parts of the polyesterimide resin produced in Synthesis Example 2,
A can coating resin composition was produced by adding 40 parts of the polyamic acid resin produced in Synthesis Example 3.

Comparative Example A commercially available coating resin composition comprising a polyamide-imide resin was obtained and used as a comparative example. Table 1 shows the results of testing the coating resin compositions of Examples 1 and 2 and Comparative Example for bending workability, adhesion resistance and acid resistance. In all cases, the present invention was excellent, and the effects of the present invention could be confirmed. Preparation of a test piece and a test method were performed as follows.

Preparation of test piece The coating resin composition was applied to an aluminum plate with a bar coater # 38.
At a temperature of 120 ° C ×
After pre-drying for 3 minutes, heat-cured at 260 ° C. for 15 minutes was used as a test piece. Bending workability After bending the test piece to 180 degrees, it was treated in boiling water for 2 hours, and the bent part was observed with a magnifying glass to evaluate the presence or absence of cracks in the coating film. ○: good without cracks, x: cracks. The adhesion test piece was treated under steam at 125 ° C. for 30 minutes, and then a cross-cut tape peeling test was performed. The number represents the number of peeled pieces in the square. Acetic acid was added dropwise to the acid-resistant test piece for hydrochloric acid and left for 90 minutes at room temperature, and then the appearance was observed. ○: good, x: marked whitening or blistering.

[0026]

[Table 1]

[0027]

As is apparent from the above description and Table 1, the resin composition for a can of the present invention is excellent in adhesion to metal, acid resistance and bending resistance, and is required to have acid resistance and the like. It is suitable as a paint for cans in the field of application.

Claims (1)

[Claims] 1. A polyester resin (A) having an imide bond in the molecular chain and (B) a polyimide resin represented by the following general formula, wherein: (However, in the formula, R ¹ represents a tetravalent organic acid residue, R ² represents a divalent diamine residue, and n represents an integer of 1 or more.) R
50 to 100 mol% of all diamine components constituting ² are diamine compounds represented by the following general formula: (However, in the formula, x represents —CH ₂ —, —O—, SO ₂ —,
_{-C (CH 3) 2 -,} - C (CF 3) 2 - and the representative) as essential components, with respect to 100 parts by weight of polyester resin (A), a polyimide resin 5 to 50 wt parts of (B) A paint resin composition for a can, which is characterized by being blended.