JP3132083B2 - Water-soluble copolyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble copolymerized polyester. More specifically, it has excellent adhesive properties and blocking resistance, and is a water-soluble copolymer suitable for a base film coating agent used in magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, general industrial materials, and the like. It relates to polyester. More specifically, the present invention relates to a water-soluble copolymerized polyester suitable as a coating agent for a base film used for a magnetic recording material.

[0002]

2. Description of the Related Art Polyesters, especially polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or poly-1.4-cyclohexane dimethylene terephthalate, and polyesters based on these are excellent. It has physical and chemical properties and is widely used as a fiber, film or sheet, and also as a molded product thereof.

[0003] In particular, polyester films have excellent heat resistance, chemical resistance, and mechanical properties, so that they are used in many applications such as magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, and general industrial materials. Used.

However, since the polyester itself is generally inert and has poor adhesiveness, various coatings such as a magnetic paint, a chemical mat paint, a diazo photosensitive paint, a gelatin composition, and a heat-sealing composition are provided on the film surface. object,
When applying or printing ink, etc., in order to improve the adhesiveness with the coating, the film surface is subjected to physical treatment such as corona discharge or plasma, or chemical treatment using alkali or amine chemicals. Various methods are known, such as a method of coating an easily adhesive substance, and the like. However, the physical or chemical surface treatment method complicates the process, not only increases the cost, but also does not provide sufficient adhesiveness. On the other hand, the method of coating an easily-adhesive substance can be carried out in the process of producing a polyester film, which is advantageous in terms of cost, and it is possible to select an adhesive substance which can cope with various coatings. . Furthermore, various water-dispersed or water-soluble copolymerized polyesters have been proposed as adhesive substances from the viewpoint of handleability of polyester films and workability during film production. For example, JP-B-47-40873 and JP-A-50-121336 disclose a copolymer of polyester with polyethylene glycol and an ester-forming metal salt of a sulfonic acid.
No. 97, JP-A-54-3848, JP-A-57
JP-A-70153, JP-A-57-70177 and JP-A-59-215318 disclose copolymers of an ester-forming sulfonic acid metal salt compound and an aliphatic dicarboxylic acid component.

[0005]

However, the above-mentioned prior art has the following problems. That is, the conventional water-dispersible or water-soluble copolyester is a mixture of an ester-forming sulfonic acid metal salt compound and a polyethylene glycol or aliphatic dicarboxylic acid component for the purpose of improving water dispersion or water solubility. However, water dispersion or water solubility is not sufficient, and in order to copolymerize polyethylene glycol or aliphatic dicarboxylic acid component, and further to copolymerize two or more dicarboxylic acid components or glycol components, polyester Although the adhesiveness is exhibited due to a remarkable lowering of the glass transition temperature, there are drawbacks such as inferior blocking resistance of the film.

[0006] The present invention is to solve these disadvantages, to provide a water-soluble copolyester excellent in adhesiveness, blocking resistance and the like, and suitable as a coating agent for a base film used for magnetic materials and the like. It is in.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention that the aromatic dicarboxylic acid component accounts for at least 50 mol% of all dicarboxylic acid components.
Terephthalic acid, naphthalenedicarboxylic acid and it
Ri Der either et ester-forming derivatives, the total radical
5 to 50 mol% with respect to carbon acid component is a polyester consisting of ester-forming sulfonic acid alkali metal salt compound and a glycol component, and represented by the following formula relative to the total glycol component 2,2-bis ( An alkali metal compound can be obtained as a reaction catalyst obtained by copolymerizing a 4'-hydroxyphenyl) propane derivative with 5 to 90 mol%.
Water-soluble copolymerized polyester. 05-1.0
This can be achieved by using a water-soluble copolyester used by weight . HO (RO) _m R'C (CH ₃ ) ₂ R '(OR) _n OH (where R is a divalent hydrocarbon group and R' is phenylene, where m and n are each 1 or more, and m + n Is 2 or more.)

[0008] terephthalic acid as the aromatic dicarboxylic acid component in the present invention, 1, 4-naphthalene dicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic aromatic dicarboxylic acids and esters thereof such as the carboxylic acid forming Sex derivatives. Of these, use of terephthalic acid or naphthalenedicarboxylic acid is preferred because of its excellent adhesion and blocking resistance. Further, these aromatic dicarboxylic acid component is used alone.

The aromatic dicarboxylic acid component is all dicarboxylic acids
It must be at least 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol%, based on the components. When the amount of the aromatic dicarboxylic acid component is less than 50 mol%, the adhesion is good, but the blocking resistance is undesirably reduced.

The ester-forming sulfonic acid alkali metal salt compounds of the present invention include sulfoterephthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid and 4-sulfonaphthalene-2,6-dicarboxylic acid. And the like, and their ester-forming derivatives. Among them, 5-sulfoisophthalic acid and sodium and potassium salts of sulfoterephthalic acid are more preferably used.

The amount of the ester-forming sulfonic acid alkali metal salt compound must be 5 to 50 mol%, preferably 8 to 45 mol%, more preferably 11 to 40 mol%, based on all dicarboxylic acid components. Particularly preferably 21 to
35 mol%.

If the amount of the ester-forming sulfonic acid alkali metal salt compound is less than 5 mol% based on all dicarboxylic acid components, it is not preferable because sufficient water solubility and adhesiveness cannot be obtained. On the other hand, if it exceeds 50 mol%, the adhesiveness reaches saturation, and conversely, the blocking resistance decreases, which is not preferable.

In the present invention, the glycol components include ethylene glycol, 1,2-propanediol, and 1,3.
-Propanediol, neopentyl glycol, 1,3
-Butanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,2
And glycols such as -cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. Among them, ethylene glycol, 1,4-butanediol and 1,4-cyclohexanedimethanol are preferred, and ethylene glycol is particularly preferred. These glycol components are preferably used alone.

Further, the water-soluble copolymerized polyester of the present invention has 2,2 represented by the following formula with respect to all the glycol components.
It is necessary to copolymerize 5 -'- bis (4'-hydroxyphenyl) propane derivative with 5-90 mol%. HO (RO) _m R'C (CH ₃ ) ₂ R '(OR) _n OH (where R is a divalent hydrocarbon group and R' is phenylene; m and n are each 1 or more; m + n Is 2 or more.) In the above formula, R is preferably an aliphatic hydrocarbon group having a linear or side chain such as ethylene, propylene or butylene, and m and n are each 1
-50 and m + n are preferably 2-100.

Preferred 2,2'-bis (4'-hydroxyphenyl) propane derivatives include, for example, 2,2 '
And bis (4'-hydroxyphenyl) propane ethylene oxide and propylene oxide adducts. Among them, 2,2'-bis (4'-hydroxyphenyl) propane ethylene oxide adduct 2,2
'-Bis (4'-β-hydroxyethoxyphenyl) propane is preferred. These 2,2'-bis (4'-hydroxyphenyl) propane derivatives may be used alone or in combination of two or more.

The copolymerization amount of the 2,2'-bis (4'-hydroxyphenyl) propane derivative is preferably 10 to 80 mol%, more preferably 15 to 70 mol%, and particularly preferably 20 to 60 mol%. 2,2'-bis (4'-
If the copolymerization amount of the (hydroxyphenyl) propane derivative is less than 5 mol%, it is not preferable because sufficient adhesiveness cannot be obtained. On the other hand, if it exceeds 90 mol%, the adhesiveness reaches saturation, and conversely, the blocking resistance decreases, which is not preferable.
By copolymerizing the 2,2′-bis (4′-hydroxyphenyl) propane derivative in an amount of 5 to 90 mol%, a water-soluble copolymerized polyester having excellent adhesion and blocking resistance can be obtained.

As a specific method for producing the water-soluble copolymerized polyester of the present invention, for example, terephthalic acid and an ester-forming derivative thereof as an aromatic dicarboxylic acid component;
The water-soluble copolymerized polyester using ethylene glycol as a glycol component will be described. Terephthalic acid, an ester-forming alkali metal salt compound of sulfonic acid (for example, 5-sodium sulfoisophthalic acid) and ethylene glycol and 2,2'-bis (4
'-Hydroxyphenyl) propane derivative is subjected to a direct esterification reaction or dimethyl terephthalate, an ester-forming alkali metal salt compound of sulfonic acid (for example, 5-
A first transesterification reaction between sodium dimethyl sodium sulfoisophthalate) and ethylene glycol and a 2,2'-bis (4'-hydroxyphenyl) propane derivative;
A method of producing by a step reaction and a second step of subjecting the reaction product of the first step to a polycondensation reaction; B. Terephthalic acid or its ester-forming derivatives,
After completion of the first step of directly esterifying or transesterifying the ester-forming sulfonic acid alkali metal salt compound with ethylene glycol, and then subjecting the reaction product to a second step of polycondensation, the polyester is obtained. 2,2'-bis (4
'-Hydroxyphenyl) propane derivative is added and the method for producing the same can be mentioned.

At this time, as the reaction catalyst, conventionally known alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like are used, and further, a phosphorus compound and the like may be used as a coloring inhibitor.

[0019] Note that the water-soluble copolymerized polyester of the present invention, the adhesive, from the viewpoint of blocking resistance, to use or addition of an alkali metal compound as a reaction catalyst at any stage of copolyester manufacturing process. Examples of the alkali metal compound include lithium compounds such as lithium chloride, lithium hydroxide, and lithium acetate, and sodium compounds and potassium compounds. Of these, lithium compounds are preferable. Addition amount of alkali metal compound (use
Amount) is 0.05 to 1.0% by weight based on the obtained water-soluble copolymerized polyester , and more preferably 0.07% by weight.
~ 0.8% by weight is preferred. If the addition amount of the alkali metal compound is less than 0.05% by weight, the blocking resistance deteriorates, and if it exceeds 1.0% by weight, the adhesiveness decreases, which is not preferable. The intrinsic viscosity of the water-soluble copolymerized polyester of the present invention is not particularly limited, but is preferably 0.3 or more, more preferably 0.35 or more, and particularly preferably 0.4 or more from the viewpoint of adhesiveness.

The glass transition temperature of the water-soluble copolymerized polyester of the present invention is not particularly limited, but is preferably 60 ° C. or higher, more preferably 65 ° C. or higher, and particularly preferably 70 ° C. or higher.
° C or higher. If the glass transition temperature of the water-soluble copolymerized polyester is less than 60 ° C., the blocking resistance is insufficient, which is not preferable.

The water-soluble copolymerized polyester of the present invention may contain a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment,
An organic lubricant such as a dye, a fatty acid ester, or a wax or an antifoaming agent such as a polysiloxane may be blended. Further, for the purpose of imparting lubricity, clay, mica, titanium oxide, calcium carbonate, kaolin, wet and Dry process silica or even colloidal silica, calcium phosphate,
Inorganic particles such as barium sulfate and alumina, as well as organic particles containing acryl, styrene, silicon and the like as constituents may be blended.

The water-soluble copolyester of the present invention is suitably used as a coating agent for various films for the purpose of imparting adhesiveness. In this case, the copolyester is dissolved in water and used as an aqueous solution. . This aqueous solution does not have strictness in the physical and chemical senses, and includes those in which most are dissolved in water and some are finely dispersed. Also, when the water-soluble copolyester is solubilized or in an aqueous solution, if necessary, an organic lubricant such as a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment, a dye, a fatty acid ester, a wax, or a defoaming agent such as polysiloxane. Agents for the purpose of imparting lubricity and the like, such as clay, mica, titanium oxide, calcium carbonate, kaolin, wet and dry silica, and also colloidal silica, calcium phosphate, barium sulfate and alumina. Inorganic particles and also organic particles containing acrylic, styrene, silicon or the like as constituent components may be blended.

As a specific method for producing a film using the water-soluble copolyester of the present invention, for example, when polyethylene terephthalate is used, the case where the water-soluble copolyester of the present invention is applied to a film will be described. First, the polyethylene terephthalate is dried and melt-extruded to form an unstretched sheet, and then biaxially stretched and heat-treated to form a film. The biaxial stretching may be any of longitudinal and transverse sequential stretching or simultaneous biaxial stretching, and the stretching ratio is not particularly limited, but usually 2.0 to 5.0 times each in the longitudinal and transverse directions. Alternatively, after stretching in the longitudinal and transverse directions, the film may be stretched again in any of the longitudinal and transverse directions.

At any stage during this step, an aqueous solution of the water-soluble copolymerized polyester of the present invention is applied to the surface of the polyester film. As a coating method, a known coating method such as a reverse coating method, a gravure coating method, a die coating method, or a wire bar method can be used. The coating is preferably performed during the production process of the polyester film. More preferably, the unstretched sheet is uniaxially stretched in either the vertical or horizontal direction, and then an aqueous solution of a water-soluble copolymerized polyester is applied, and then uniaxially stretched. A method in which a film is produced by biaxial stretching and heat treatment in a direction different from the above is preferred.

[0025]

The present invention will be described in more detail with reference to the following examples. The characteristics in the examples were measured as follows.

A. Intrinsic viscosity of the copolymerized polyester;
[Η] It was measured at 25 ° C. using an o-chlorophenol solvent.

B. Glass transition temperature (Tg) of copolymerized polyester Differential scanning calorimeter (DS manufactured by PERKIN ELMER)
Using C-2), 10 mg of the copolyester was heated at a heating rate of 16 ° C./min and measured.

C. Water solubility of copolymerized polyester 5 g of copolymerized polyester is put in 100 g of water,
After stirring and dissolving at 2 ° C. for 2 hours and cooling, the mixture was filtered through a 5 μ filter. The water solubility of the copolymerized polyester was determined based on the dissolved state and the amount of the residue on the filter. ○: The aqueous solution is transparent or slightly turbid,
Almost no residue was found. Δ: The aqueous solution was slightly cloudy, and a filtered product was observed. X: It was difficult to dissolve in water, or the aqueous solution was strongly cloudy, and a large amount of filtered product was observed.

D. Adhesiveness An aqueous solution of a copolymerized polyester was applied, and Diferacoat VD1654 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 100 parts by weight and Sumidur N75 (manufactured by Sumitomo Bayer Co., Ltd.) A coating consisting of parts by weight was applied with a bar coater so as to have a thickness of 6 μm after drying, and dried at 100 ° C. for 5 minutes to form a coating layer. A cellophane adhesive tape is stuck on the surface of the coating layer, and after passing through a nipple with a linear pressure of 50 kg / cm, it is rapidly peeled in the direction of 180 degrees. The adhesiveness was determined by measuring the area of the coating layer adhered to the cellophane adhesive tape at that time. ：: The area of the coating layer adhered to the cellophane adhesive tape was 10
%, Which is excellent in adhesiveness. ：: The area of the coating layer adhered to the cellophane adhesive tape was 10
Less than 20%, slightly superior in adhesiveness. Δ: The area of the coating layer adhered to the cellophane adhesive tape was 20.
% To less than 40%, and the adhesion is slightly inferior. ×: The area of the coating layer adhered to the cellophane adhesive tape was 40.
% Or more and is inferior in adhesiveness.

E. Blocking resistance An aqueous solution of a copolymerized polyester was applied, and the adhesive layer surfaces of a film provided with an adhesive layer were superimposed on each other (superimposed area: 3 cm × 4 cm) under a load of 500 g / 12 cm ² at 50 ° C., 85 % RH for 24 hours, and the shear stress of the overlapped portion was measured using a Tensilon tensile tester.
The measurement was performed at a tensile speed of 20 cm / min.

Example 1 47.1 parts by weight of dimethyl terephthalate, 21.5 parts by weight of dimethyl 5-sodium sulfoisophthalate, 31.2 parts by weight of ethylene glycol, 2,2'-bis (4'-β
39.9 parts by weight of (-hydroxyethoxyphenyl) propane, 0.04 part by weight of calcium acetate as a transesterification reaction catalyst, 0.03 part by weight of antimony trioxide as a polycondensation reaction catalyst, and a polyester capable of obtaining lithium acetate as an alkali metal compound. 0.35% by weight was added thereto, and transesterification was carried out according to a conventional method, and then 0.05 part by weight of trimethyl phosphate was added. Then, the temperature was gradually increased and the pressure was reduced, and finally a polycondensation reaction was performed at 280 ° C. and 1 mmHg or less, to obtain a water-soluble copolymerized polyester.
The intrinsic viscosity measured at 25 ° C using an o-chlorophenol solvent was 0.72, and the glass transition temperature was 73 ° C.

5 g of the obtained water-soluble copolymerized polyester was placed in 100 g of water, dissolved by stirring at 80 ° C. for 2 hours, cooled, and filtered with a 5 μ filter to obtain an aqueous solution of the water-soluble copolymerized polyester. The aqueous solution of the water-soluble copolymerized polyester was almost transparent, and no product was found on the filter.

On the other hand, after sufficiently drying polyethylene terephthalate having an intrinsic viscosity of 0.60, it is supplied to an extruder, melted at 285 ° C., extruded in a sheet form from a T-type die, and cooled at 30 ° C. It was cooled and solidified by a drum to obtain an unstretched film. Next, the unstretched film was heated to 95 ° C. and stretched 3.4 times in the machine direction to obtain a uniaxially stretched film. Further, the aqueous solution of the water-soluble copolymerized polyester obtained above was applied to one surface of the uniaxially stretched film by gravure coating so that the coating thickness after biaxial stretching was 0.15 μm. Subsequently, the film was heated to 100 ° C., stretched 3.5 times in the horizontal direction, and heat-treated at 200 ° C. to obtain a polyester film having a 75 μm-thick adhesive layer. Table 2 shows the properties of the obtained film. Both the adhesion and blocking resistance of the film were good.

Comparative Example 1 In the same manner as in Example 1, without using the 2,2'-bis (4'-hydroxyphenyl) propane derivative, 79.5 parts by weight of dimethyl terephthalate, 5-sodium sulfoisophthalate Acid dimethyl 21.4 parts by weight, ethylene glyco-
A polyester film having a copolymerized polyester and an adhesive layer was obtained by using 59.8 parts by weight of toluene. Table 2 shows the results. The intrinsic viscosity of the obtained water-soluble copolymerized polyester was 0.70, and the glass transition temperature was 70 ° C.
Further, the aqueous solution of the water-soluble copolymerized polyester was almost transparent, and although there was no filter product, the obtained film was inferior in blocking resistance.

Examples 2 to 4, Comparative Examples 2 to 4 As described in Table 1, the types and amounts of the dicarboxylic acid component, the glycol component and the alkali metal compound were changed in the same manner as in Example 1, A polyester film having a copolymerized polyester and an adhesive layer was obtained. Table 2 shows the results. Examples 2 to 4 were within the scope of the present invention, and both the adhesion and the blocking resistance were good. On the other hand, Comparative Example 2 and Comparative Example 3 contained 2,2 in the glycol component.
It does not use the '-bis (4'-hydroxyphenyl) propane derivative, but uses polyethylene glycol as the glycol component or aliphatic dicarboxylic acid as the dicarboxylic acid component, all of which have poor blocking resistance. Was something. In Comparative Example 4, the amount of the compound having a sulfonic acid alkali metal base was out of the range of the present invention, and the obtained copolymerized polyester was poor in water solubility.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

According to the present invention, as described above, a specific amount of specific
A polyester comprising an aromatic dicarboxylic acid component, an ester-forming sulfonic acid alkali metal salt compound and a glycol component, and 2,
Comprising 2'-bis (4'-hydroxyphenyl) propane derivative was allowed to 5-90 mol% copolymer, the reaction catalytic
-Soluble copolymers that can be used to obtain alkali metal compounds
0 for tell . A water-soluble copolymerized polyester used in an amount of 0.5 to 1.0% by weight , having excellent water solubility, excellent adhesion and blocking resistance, and a coating agent for a base film used for a magnetic recording material and the like. It is preferably used.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-273634 (JP, A) JP-A-57-70153 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (1)

(57) [Claims] 1. A Ri least 50 mol% aromatic dicarboxylic acid component der respect to the total dicarboxylic acid components, the aromatic dicarboxylic
Bonic acid components include terephthalic acid, naphthalenedicarboxylic acid and
And any of their ester-forming derivatives,
5 to 50 mol% for the total dicarboxylic acid component is a polyester consisting of ester-forming sulfonic acid alkali metal salt compound and a glycol component, and represented by the following formula relative to the total glycol component 2,2-bis (4'-hydroxyphenyl) propane derivative copolymerized with 5-90 mol% , alkali metal compound as reaction catalyst
0.05 to the water-soluble copolymerized polyester obtained.
Water-soluble copolymerized polyester used in an amount of 1.0 to 1.0% by weight . HO (RO) _m R'C (CH ₃ ) ₂ R '(OR) _n OH (where R is a divalent hydrocarbon group and R' is phenylene; m and n are each 1 or more; m + n Is 2 or more.)