JPS6333419A - Production of water-soluble polyester resin - Google Patents

Abstract

PURPOSE:To obtain the titled composition having high glass transition temperature in high efficiency, by reacting an acid component with a glycol component, adding an aromatic dicarboxylic acid containing sulfonic acid base to the reaction system after a specific amount of water based on theoretical amount is distilled out and copolymerizing the components. CONSTITUTION:(A) A dicarboxylic acid component (e.g. terephthalic acid) containing >=20wt% isophthalic acid and (B) a glycol component containing >=50mol% ethylene glycol are subjected to dehydrative condensation e.g. at 140-250 deg.C and >=wt% of theoretical distillation amount of water is distilled out. Thereafter, the reaction system is added with (C) preferably 0.04-0.3mol (based on 1 mol of the component A) of an aromatic dicarboxylic acid containing sulfonic acid base (e.g. 5-sodiosulfoisophthalic acid) and the components are made to react with each other to obtain the objective resin.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention provides a sulfonic acid group-containing polyester resin (hereinafter sometimes referred to as water-soluble polyester resin) that has further improved physical properties such as solution stability and water solubility. Relating to a manufacturing method.

[Conventional technology 1] Water-soluble polyester resins utilize their unique properties to be used as anchor coats for base films such as polyethylene terephthalate in magnetic tapes, as well as for various types of fibers such as binders for magnetic tapes and fiber glues. Processing agent,
Demand for products such as &i fibers and water-based adhesives is increasing.

Examples of the production of such water-soluble polyester resins include, for example, in Japanese Patent Publication No. 47-40871, dicarboxylic acids such as terephthalic acid and isophthalic acid, glycols such as ethylene glycol, propylene glycol, and polyethylene glycol, and It is described that a sulfonic acid group-containing aromatic dicarboxylic acid such as an acid is reacted.

[Problem to be Solved by the Invention 1] However, according to the studies of the present inventors, the existence of ether bonds based on polyethylene glycol in the main chain of the water-soluble polyester resin obtained by the method described in the above-mentioned publication. Of course, even if other glycol components, such as ethylene glycol, are converted into ether glycol, that is, diethylene glycol or triethylene glycol, before condensation, and then react with dicarboxylic acid, etc. It turns out that there are far more ether bonds in the main chain than expected. The cause of this etherification reaction between ethylene glycols is not clear, but since such a fact is not normally observed in general water-insoluble polyesters, the present inventors developed a sulfonic acid group-containing aromatic compound used to impart water solubility. It is speculated that the group dicarboxylic acids play a catalytic role in the reaction between glycols.

At the same time, it has also been found that the presence of an excessive amount of ether bonds causes the glass transition temperature of the polyester resin to be lowered more than expected.

That is, when using the conventional production method described above, even if only ethylene glycol is used as the raw material glycol component, more ether bonds than necessary are introduced into the resin, making it difficult to produce a resin with the desired positive transition temperature. I couldn't get it.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventors of the present invention have thoroughly and thoroughly investigated the method for producing water-soluble polyester resins. As a result, in producing a water-soluble polyester resin into which a sulfonic acid group is introduced by reacting a dicarboxylic acid, an aromatic dicarboxylic acid containing a sulfonic acid group, and glycol, (1) the total use of isophthalic acid as the dicarboxylic acid; (2) ethylene glycol is used as the main component as the glycol, and (3) 95% by weight or more of the total amount of sulfonic acid group-containing aromatic dicarboxylic acid used is 50% by weight of the theoretical distilled water amount. When charging after more than % by weight of water has been distilled off, a polyester resin having a higher glass transition temperature can be obtained compared to water-soluble polyester resins obtained by conventional methods. We have completed the present invention by discovering that the production method has the unexpected effect of increasing the reaction rate and therefore improving production efficiency. - The polyester resin of the present invention contains at least 20% by weight of isophthalic acid as dicarboxylic acid. Any dicarboxylic acid component, sulfonic acid group-containing aromatic dicarboxylic acid, or glyfur component can be used, except that the main component is ethylene glycol as the glycol component. Isophthalic acid is 2
If it is less than 0% by weight, the solution stability of the resin will be impaired, making it impossible to achieve the object of the present invention. Dicarboxylic acid components include terephthalic acid, malonic acid, dimethyl remalonic acid, koha(acid), geltaric acid, 7dipic acid, trimethyladipic acid, pimelic acid, 2,2-methylgeltaric acid, azelaic acid, sebacin. acid, 7-maric acid, maleic acid, itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5- Norbornanedicarboxylic acid, 1,4
-7 tar acid, siphenic acid, 4,4゛-oxybenzoic acid, diglycolic acid, thiodipropion, and 2,5
-S7tale dicarboxylic acid and the like.

These may be acid anhydrides, esters, chlorides, etc., and include, for example, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl 2,6-7taledicarboxylate, dimethyl isophthalate, dimethyl terephthalate, and diphenyl terephthalate. .

In addition to the above, in small amounts, polyvalent carboxylic acids of trivalent or higher valence, such as trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-
1,2,3) Ricarboxylic acid anhydride, trimesic acid, etc. can also be used.

As the sulfonic acid group-containing aromatic dicarboxylic acid, 5-
Examples include sodiosulfoisoheptalic acid, 5-potassium sulfoisophthalic acid, etc., but are not limited to these 4.

In the present invention, ethylene glycol should be used as the main component, preferably 50 mol% or more, more preferably 80 mol% or more of the glycol component.

When ethylene glycol is not the main component, that is, when the ethylene glycol content is less than 50 mol % and the pool component is a single glycol, such as propylene glycol, it is difficult to obtain the effects of the present invention. In particular, if the amount of this component is too small, the resin will become soft, which is not preferable for the purposes of the present invention. In this sense, in the present invention, the term "main component" means the component used in the largest amount among the Glyfur components.

Any glycol other than ethylene glycol can be used. For example, diethylene glycol, propylene glycol, 1.3-7'ropanediol, 2.4
-dimethyl-2-ethylhexane-1,3-diol,
2,2-dimethyl-1,3-7'lovandiol (neopentyl glycol), 2-ethyl-2-butyl-1,
3-propanediol, 2-ethyl-2-1butyl-
1,3-propanesol, 1,3-butanediol,
1,4-butanediol, 1,5-bentanediol,
1,6-hexanediol, 3-methyl-1,5-bentanediol, 2,2゜4-trimethyl-1,6-hexanediol, 1,2-cyclohexane dimetatool,
1f3-Cyclohexane dimetatool, 1,4-cyclohexane dimetatool, 2゜2.4.4-tetramethyl-1,3-cyclobutanediol, 4,4゛-thiosyphenyl-7-yl, 4,4゛-methylene diol 7 er/-er, 4.4
'-(2-Flubornylidene) diphenol, 4,4'-dihydroxybiphenol, o-tl- and p-dihydroxybenzene, 4,4'-isopropylidene 7enol, 4,4'-isopropylidene bis(2,6 -dichlorophenol), 2,5-s7talediol and p
-xylene diol.

In addition to the above, trivalent or higher polyhydric alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, )rimethylolethane, 1,3.6-hexandriol, etc. can also be used in small amounts. It is possible.

The desired water-soluble polyester resin is produced by condensing the dicarboxylic acid component, the sulfonic acid group-containing aromatic dicarboxylic acid, and the Glyfur component. The greatest feature is that 95% by weight or more, more preferably 97% by weight or more of the total amount of dicarboxylic acid used is charged into the system after 50% by weight or more of the theoretical distilled water amount has been distilled off. By such charging, polyetherization of ethylene glycol is appropriately suppressed, and the desired water-soluble polyester resin can be obtained. As a result, the desirable amount of the ether component present in the polyester resin, for example when used as a coating, is 40 mol % or less, more preferably 30 mol % or less, based on the glycol component.

The above 5i! Except for the above characteristics, generally known reaction conditions are employed. The total amount of each component to be charged is 0.04-0.3 mol, more preferably 0.06-0.
．． 2 mol, Glyfur component 1.0 based on the total amount of dicarboxylic acid and aromatic dicarboxylic acid containing sulfonic acid group.
It is often prepared at 1 cup of ~2.0 times the mole, more preferably 1.2 to 1.8 times the mole. In particular, the content of sulfonic acid groups in the resin has a great effect on the physical properties of the resin, so the final content of this group should be 6 to 20 mol%, more preferably 6 to 15 mol%, based on the total acid components. If it is less than 6 mol %, it will not become water soluble, and if it exceeds 20 mol %, the water solubility will be too strong and the object of the present invention cannot be achieved.

To give a typical example in an actual reaction, the total amount of the dicarboxylic acid component and glycol component and, depending on the case, less than 5% by weight of an aromatic dicarboxylic acid containing a sulfonic acid group are charged into a reactor together with a catalyst, Dehydration condensation is carried out by raising the temperature to . As catalysts used in this case, zinc acetate, zinc chloride, stannous lauryl, dibutyltin oxide, etc. are used, and these usually react with dicarboxylic acids.
It is charged in an amount of 0.05 to 0.15% by weight. A media is not particularly necessary, but if necessary, methyl acetate, benzene, acetone,
Inert solvents such as xylene and toluene may also be used.

As the condensation reaction progresses, water is distilled out, so as mentioned above, when 50% by weight or more of the theoretical distilled water amount has been distilled out, the sulfonic acid group-containing aromatic dicarboxylic acid may be charged all at once or continuously. .

If the sulfonic acid group-containing aromatic cyclocarboxylic acid is charged too early, that is, when the amount of distilled water is less than 50% by weight of the theoretical amount of distilled water, the ether component in the resin will still increase, making it impossible to achieve the purpose.

Thus, the water-soluble polyester resin obtained by the method of the present invention has particularly good adhesion to polyesters such as polyethylene terephthalate, so it can be used as an anchor coating agent for molded products such as films, sheets, and containers, or as a printing ink for polyester films. For overprinting on printed surfaces, magnetic powder coating binders for polyester tapes, anchor coating agents for floppy disks, vehicle resins for paints or adhesives for polyester coatings, undercoats or topcoats for metal vapor deposition on polyester films. It is useful as such. Of course, the present invention is not limited to polyester moldings, but can also be widely applied to plastic moldings, metals, paper, etc. Furthermore, the water-soluble polyester resin of the present invention is
It can also be used as a fiber processing agent, including fiber glue, and as a fiber material.

When used for the above-mentioned various purposes, the water-soluble polyester resin can be prepared as an aqueous solution or an organic solvent solution, and various additives can be added thereto as necessary.

As the solvent used for the polyester resin of the present invention,
Examples include water, water/meth-7-alcohol mixed solvent, water/isopropyl alcohol mixed solvent, dioxane, methylene chloride, chloroform, tetrahydro-7-alcohol, cellosolve/cyclohexanone/dioxane mixed solvent, such as toluene, acetic ester, It is insoluble or poorly soluble in commonly used organic solvents for polyester resins, such as ketone solvents.

Additives include colorants (dyes such as inorganic or organic pigments, acid dyes, basic dyes, oil-soluble dyes, and disperse dyes), oils (vegetable oils, processed oils, mineral oils), plasticizers, waxes, and drying agents. (metallic soap, etc.), dispersants, wetting agents, emulsifiers, delifying agents, stabilizers, antifoaming agents, etc. can be added.

The substrate to which the resin solution is applied may be any film, tape, sheet, disk, card, drum, or the like. Materials for films and tapes include acetylcellulose, polyester, polycarbonate, polypropylene, polyimide, polyvinyl chloride, etc., and all methods include the lade coating method, reverse roll method, gravure method, cast coating method, and spray coating method. be done.

By adopting the production method of the present invention, the reaction efficiency is improved and water-soluble polyester resin can be produced industrially advantageously.The resulting polyester resin has appropriate resin rigidity and water solubility, and also has good solution stability. This makes it an excellent resin.

[Examples] Next, the method of the present invention will be explained in more detail with reference to Examples. "Parts" or F%] are by weight unless otherwise specified.

In the examples, TPA is terephthalic acid, IPA is isophthalic acid,
SIPM means 5-sodiosulfoiiso7talic acid, and EG means ethylene glycol.

Example 1 TPA O, 45 mol, IPA O, 45 mol, E
5 mol of Gl was charged with 0.1 part of zinc acetate, 190
The temperature was raised to ~220°C, and a dehydration condensation reaction was carried out while removing water. When the amount of distilled water reached 25 g (77% of the theoretical amount of distilled water) (3 hours after the start of the reaction), 0.10 mol of SIPM was charged and the reaction was continued to give a solution with a molecular weight of 20,000.
A water-soluble polyester resin having an acid value of 3KOH+++g/g and a Tg (ff lath transition temperature) of 66°C was obtained. The physical properties were investigated using the following method.

○Aqueous solution stability The resin was dissolved in hot water at 90° C. to a solid content of 20%, and the presence or absence of aggregates in the solution was observed when it was left at room temperature for one week.

○Solvent Resistance After the resin formed into a film was immersed in ethyl acetate for 5 minutes, the change in transparency of the film was visually evaluated.

Examples 2 and 3, Comparative Examples 1 to 3 In Example 1, the total amount of each component was kept the same, but only the method of preparing SIPM was changed as shown in the table,
produced resin.

The glass transition temperature, aqueous solution stability, and solvent resistance of the resin on each side were measured and evaluated.

The above results are summarized in the table on the next page.

Example 4, Comparative Example 4 In Example 1, when the SIPM was charged at a time when the theoretical distillation amount of water was 60% (Example 4), 4
When the resin was manufactured by changing each case to the case where the temperature was 0% (Comparative Example 4), the positive transition temperature of Example 4 was 66°C, but it was clearly 57°C in Comparative Example 4. A difference was seen in

[Effect 1] As is clear from the above results, by adopting the method of the present invention, water with the same charging composition but with a higher glass transition temperature than before and with excellent physical properties;
A soluble polyester resin is obtained.

Claims (1)

[Claims] In producing a water-soluble polyester resin into which a sulfonic acid group is introduced by reacting a dicarboxylic acid, an aromatic dicarboxylic acid containing a sulfonic acid group, and glycol, (1) isophthalic acid is used as a dicarboxylic acid component to form a dicarboxylic acid. 20% or more of the total amount of acid used, (2) ethylene glycol is used as the main component as the glycol, and (3) 95% or more of the total amount of sulfonic acid group-containing aromatic dicarboxylic acid used is theoretically distilled. A method for producing a water-soluble polyester resin, which comprises charging after 50% by weight or more of water has been distilled out.