JPS5912972A - Polyester coating agent - Google Patents

Abstract

PURPOSE:To provide a polyester-based coating agent composed mainly of a polyalkylene terephthalate copolymerized with a specific amide unit in the molecular chain, and giving a coating film having excellent processability. CONSTITUTION:The objective polyester-based coating agent is composed mainly of a polyalkylene terephthalate containing 0.1-20wt% of the amide unit of formula I [Ar1 and Ar2 are 1,2-, 1,3- or 1,4-phenylene group (or their mixture)] and/or formula II [Ar3 is 1,2-, 1,3- or 1,4-phenylene group (or their mixture); R1 and R2 are H or lower alkyl; when >=70mol% of Ar3 is 1,4-phenylene, n is integer of 1-5, and in the other cases, n is integer of 1-20] as a copolymer unit in the molecular chain.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention-1 relates to a polyester-based coating agent that forms a coating film with excellent workability. More specifically, a polyester coating whose main component is polyalkylene terephthalate, which is obtained by copolymerizing 0.1 to 20% by weight of amide units represented by the following general formulas (1) and/or (2) in a 15-molecule polymer. Regarding drugs.

1Ars is 1.2-. 1j- or 1.4-7e1 Conventionally, the surface coating of industrial products was usually applied after processing, but in recent years, a coating called pre-coated metal has been applied for the purpose of saving labor and energy. Methods of manufacturing products by processing steel sheets are attracting attention. In order for such pre-coated metal coatings to be used in machining, they must (1) have excellent adhesion to the base material, (2) have good flexibility and bendability, and (3) have high surface hardness. It is. However, conventionally used paints made of alkyd resins, acrylic resins, vinyl resins, polyester resins, etc. have some problems and have various limitations in use. For example, materials with excellent flexibility and bendability have low hardness and are therefore less susceptible to damage on the surface during processing, resulting in problems such as cracks and cracks occurring when bent. As a result of various studies on coating agents that form a coating film with excellent adhesion to substrates, good flexibility and flexibility, and high hardness, the present inventors found that polyalkylene terephthalate having a specific amide unit We have discovered that a coating agent containing as a main component satisfies these requirements, and have arrived at the present invention.

In the present invention, the amide unit represented by the above-mentioned general formula (1) and/or (2) is contained in an amount of 0.1 to 20% by weight.
It is necessary to copolymerize the polyalkylene terephthalate within the range of . Copolymerization amount is 0.1ffiJ1%
If it is less than 20%, the above-mentioned performance will not be achieved sufficiently, and if it is more than 20%, it will be difficult to produce a polymer with a high degree of polymerization or the polymer will become colored, so it is preferable. do not have. Furthermore, as can be seen from the formula, the amide unit represented by the general formula (1) must not be repeated continuously in the molecular chain, and the amide unit represented by the general formula (2
), when 70 mol% or more of Ars is a 1,4-phenylene group, n is 1 to 5.
In other cases, n must be in the range of 1 to 20. If the amide unit is not within these ranges, the flexibility and flexibility of the coating film will decrease, which is not preferred. Specific examples of the amide unit represented by the general formula (1) include dicarboxylic acids selected from terephthalic acid, isophthalic acid and orthophthalic acid, P-phenylenediamine, m
Examples include amide units obtained from diamines selected from -phenylenediamine and O-phenylenediamine. Among these, amide units obtained from terephthalic acid and P-phenylenediamine are particularly preferred.

Examples of the amide unit represented by the general formula (2) include amide units obtained from a dicarboxylic acid selected from terephthalic acid, isophthalic acid, and orthophthalic acid and piperazine or dimethylpiperazine.

The copolymerized polyalkylene terephthalate used in the present invention must contain at least 80% by weight of alkylene terephthalate units. As the glycol component constituting the alkylene terephthalate unit, ethylene glycol, trimethylene glycol and tetramethylene glycol are preferred from the viewpoint of the hardness and heat resistance of the coating film.

The copolymerized polyalkylene terephthalate used in the present invention contains amide units and alkylene terephthalate.
In addition to the t unit, other components may be included within a range that does not impair the object of the present invention. Examples of such ingredients are:
Dicarboxylic acids such as isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyl etherdicarboxylic acid, succinic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, hexamethylene glycol, Examples include neopentylene gellicol, cyclohexane dimetatool, diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, and the like. Further, a small amount of a polyfunctional compound such as pentaerythritol, trimethylolpropane, trimellitic acid, pyromellitic acid, etc. may be contained within a range that does not cause gelation.

The copolymerized polyethylene terephthalate used in the present invention is produced by reacting the raw material for producing polyethylene terephthalate or its polycondensate with an amide compound represented by the following general formula (3) and/or (4). .

Among these, it is preferable that R, and R4 are phenyl groups or ring-substituted derivatives thereof in order to proceed the reaction smoothly and obtain a polymer with little coloring. The copolymerization reaction can be carried out by melt polycondensation or solid phase polycondensation of a mixture of the raw material for producing polyalkylene terephthalate or its disarmament material and the above-mentioned amide compound, but melt polycondensation or condensation is preferred for ease of operation. Preferable from this point of view. The polyamide compound is preferably mixed at a time when esterification or transesterification reaction is completed.

The polycondensation reaction can be carried out under conditions normally employed for polycondensation of polyalkylene terephthalate.

That is, in the case of melt polycondensation, using an antimony compound, titanium compound, germanium compound, or zinc compound as a catalyst, under reduced pressure at a temperature slightly higher than the melting point of polyalkylene terephthalate, and in the case of solid phase polymerization,
The reaction is carried out at a temperature between 0.degree. C. and the melting point under reduced pressure or in an inert gas stream. Since most of the added amide compound is copolymerized with polyalkylene terephthalate, a copolymer of any desired composition can be obtained by adjusting the amount of the amide compound added. In addition, the intrinsic viscosity of the copolymerized polyalkylene terephthalate is 0.5 or more, and the above-mentioned amide compound can be synthesized by mixing a dicarboxylic acid chloride and a diamine, piperazine, or a ring-substituted derivative of piperazine, and reacting the mixture in a medium. It is preferable to carry out this process, and examples of solvents include hexafluorinated hydrocarbons such as methylene chloride, chloroform, and dichloroethane, and benzene, n-hexane, dimethylacetamide, dimethylformamide, and N-hexane.
Methylpyrrolidone, hexamethylphosphoramide, a mixed solvent thereof, etc. will be mentioned and omitted. It is preferable to add to these solvents a tertiary amine such as amine, tri-1-butylamine, N-ethylpiperidine, N-ethylmorpholine, etc., which facilitates the reaction. In addition, during the reaction, monovalent or divalent lower aliphatic alcohol,
Either phenol or a monovalent or divalent phenol derivative is allowed to coexist, or a dicarboxylic acid chloride monoester (esters with monovalent or divalent lower aliphatic alcohols, phenol, or monovalent or divalent phenol derivatives, etc. are preferred). If they are allowed to coexist, an amide compound having an ester bond at the terminal can be obtained, and the degree of polymerization of the obtained amide compound can be adjusted by appropriately selecting the amount used. In addition, the degree of polymerization is 1
When producing an amide compound, the molar ratio of diamine, piperazine, or a ring-substituted derivative of piperazine and dicarboxylic acid silolide monoester is 1:2, or the dicarboxylic acid chloride monoester is in slightly excess. It is preferable to react.The reaction proceeds rapidly at the same time as the raw materials are mixed, and an amide compound is obtained.The reaction temperature is suitably from room temperature to around 0°C.The above dicarboxylic acid chloride monoester is , is obtained by reacting dicarboxylic acid chloride with alcohol or phenol. During the reaction, in order to proceed smoothly with the esterification reaction, triethylamine, tri-n-propyl 7mine, tri-n-
Tertiary amines such as butylamine, N-ethylpiperidine, N-ethylmorpholine, etc. may also be added. The obtained dicarboxylic acid chloride monoester can be used after being purified, or the reaction product may be used as it is.

The coating agent of the present invention can be used in any form such as a solution, melt, slurry, powder, or film. In addition, the shape and material of the base material to be coated are not particularly limited, and it can be applied to base materials of any shape such as plate, columnar, cylindrical, and linear1.There are various materials for the base material. metals, plastics, etc.

There is no particular limit to the thickness of the coating film, but it is 0.01r/rln~
Around 5 questions is appropriate. More specific uses include coated steel plates, can interior coatings, and electric wire coatings.

The coating agent of the present invention may contain conventionally known plasticizers, stabilizers, optical brighteners, flame retardants, and lubricants, if necessary.

Example 1 Anhydrous trans-2,5-dimethylpiperazine 0.096 mol, phenol 0.024 mol, triethylamine 20
Dissolve pnl in 5007 nt methylene chloride. Methylene chloride solution 1 in which 0.060 mol of terephthaloyl chloride and 0.060 mol of inphthaloyl chloride were dissolved in this solution.
00rnl was added dropwise at room temperature over a period of 30 minutes, and then the reaction was allowed to proceed at room temperature for 50 minutes, and the residue obtained by distilling off methylene chloride from the reaction solution was thoroughly washed with water, and then dried under vacuum. An amide compound was obtained. The average degree of polymerization of the obtained amide compound was 2.4 according to NMR spectrum analysis.

Bis-β hydroxyethyl terephthalate 100 parts, triphenyl phosphate 0.01 part, antimony trioxide 0.0
25 parts were melted at 220°C, 0.5 part of the amide compound obtained above was added, and the mixture was stirred for 10 minutes. Next, the pressure of the reaction system was gradually reduced and the temperature was raised to 280℃ and 0.5BH.
g or less, and polymerization was continued for 2 hours under these conditions to obtain copolymerized polyethylene terephthalate.

The intrinsic viscosity of the obtained polymer (equal volume mixture of phenol/tetrachloroethane, 25°C) was 0.85 dt/l.

A steel plate with a thickness of 100 μm was thoroughly polished with sandpaper and then washed with A7Ton. The copolymerized polyethylene terephthalate pellets obtained above were placed on a steel plate and heated at 280°C.
The steel plate was melted and pressed using a hot press heated to 100 mL, and rapidly cooled with ice water to form an amorphous polymer film with a thickness of about 50 μm on the surface of the steel plate. The adhesion of the film is good and the surface hardness is as high as that of polyethylene terephthalate.The coated steel plate was bent at 90° and 180° at room temperature and changes in the film were observed using a reflective optical microscope. However, no change was observed in the film.

When a polyethylene terephthalate t-m plate was coated in the same manner and a bending test was performed, it was found that
In both cases of 180° bending, numerous cracks several tens of microns in length were generated in the vicinity of the folded portion of the film, parallel to the fold line.

Example 2 0.25 mol of terephthaloyl chloride was added to 200 m of benzene.
1 and heat under reflux to dissolve. 0.50 mol of pyridine was added to this solution, and while heating under reflux, 0.25 mol of 0-tertbutylphenol was added dropwise from the dropping funnel over 60 minutes to cause a reaction. The reaction was allowed to proceed for an additional 6 minutes, cooled to room temperature, and heated with 80 mA of pyridine.
After adding 50% of water and continuing stirring for 30 minutes to hydrolyze the remaining acid chloride, benzene was completely distilled off. Next, 500ml of water and 150ml of concentrated hydrochloric acid were added to convert the remaining pyridine into hydrochloride, and the precipitate was separated in a furnace and washed with water.
Added to an aqueous solution containing 0.5 mol of sodium carbonate. 1
The mixture was stirred for hours to remove insoluble diesters, the filtrate was made weakly acidic by adding concentrated hydrochloric acid, and the resulting precipitate consisting of terephthalic acid and monoester was separated, washed with water, and dried under vacuum.

Add this to 100 ml of methanol and 50 g of chloroform.
The monoester was added to a mixed solvent consisting of 1 hour of stirring to dissolve the monoester, the insoluble terephthalic acid was separated by a furnace, the solvent was removed from the liquid, and the mixture was further purified by recrystallization using benzene as a solvent. Terephthalic acid mono-0-tert phthyl esder was obtained. Next, this was reacted with thionyl chloride to obtain P-carbo(0-tertbutylphenoxy)benzoyl chloride.

0.02 mol of P-phenylenediamine was dissolved in 100 rnl of N-methylpyrrolidone cooled in a water bath, and then 0.04 mol of P-carbo(Q-tertbutylphenoxy)benzoyl chloride obtained above was added and reacted for 2 hours. I let it happen. The reaction solution was transferred into water 11, and the generated precipitate was separated in a furnace, washed with water, and vacuum dried to obtain an amide compound.

His-β hydroxyethyl terephthalate 100 parts, triphenyl phosphate 0.01 part, antimony trioxide 0.0
25 parts were melted at 220°C, 1 part of the amide compound obtained above was added, a polycondensation reaction was carried out in the same manner as in Example 1, and the intrinsic viscosity was 0.82 dt/? A copolymerized polyethylene terephthalate was obtained.

A 100μ thick steel plate polished with sandpaper is washed with A7Ton, the polyester pellets obtained above are placed on the steel plate, melted and pressed at 280°C, and then rapidly cooled with ice water to coat the polymer onto the steel plate. A film was formed. The adhesion of the film was good, and no cracks were observed in the 90° and 180° bending tests.

Patent applicant: Kuraray Co., Ltd. Same Taka Yanagi Motofu Agent: Patent Attorney Ken Honda

Claims (1)

[Claims] A polyester-based coating agent containing 0.1 to 20% by weight of amide units represented by the following general formulas (1) and/or (2) as a main component and containing tenal polyalkylene terephthalate as a main component.