JPH0481455A - Dissolution or dispersion in solvent of polyester resin poorly soluble to solvent - Google Patents

Abstract

PURPOSE:To dissolve the title polyester in a solvent by melt blending the title resin and a polyester resin readily soluble to the solvent and/or an epoxy compound followed by mixing the blend with the solvent. CONSTITUTION:A melt blend of (A) 20-80 pts.wt. of a polyester resin <=2g/100ml in the solubility in a solvent, made UP from (1) dicarboxylic acid(s) predominant in terephthalic acid and (2) diol(s) predominant in ethylene glycol and 1,4- butanediol and/or cyclohexanediol, and 80-20 pts. of (B) a second polyester resin >=20g/100ml in the solubility in the solvent, made up from (3) dicarboxylic acid(s) predominant in aromatic dicarboxylic acid and (4) diol(s) predominant in 2-10C aliphatic glycol and alicyclic glycol and/or bisphenol alkylene oxide adduct, and/or (C) a compound having two or more epoxy groups, is mixed with said solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for obtaining a resin solution or dispersion having excellent coating film properties and adhesive properties.

(Prior Art) Polyester resins have been used in a wide range of applications, including fibers, films, bottles, molding materials, paints, adhesives, and various binders. However, depending on the individual, solvent-insoluble or poorly soluble resins with high symmetry and high cohesive strength, even if they are crystalline or non-crystalline, are used for applications such as fibers, films, bottles, molding materials, powder coatings, and photomelt adhesives. Resins that are unsightly, have low symmetry, and dissolve in general-purpose organic solvents are used in solvent-based paints, adhesives, various binders,
It has been used for purposes such as clear coating agents.

In general, the former type of poorly soluble resin has a high intermolecular cohesive force and has excellent properties such as heat resistance, solvent resistance, and coating film properties, but due to the lack of an appropriate medium, it can only be molded in the molten state and coated. It has been difficult to apply thin and smooth films for use as agents or adhesives. On the other hand, the conventionally known solvent-ITJ-molten horizontal resin composite is amorphous and has a weaker cohesive force between molecules than the former, resulting in an adhesive property of 1.
．． The physical properties of the coating film were inferior.

There have been many attempts to mix two types of polyester resins and give them new properties, for example, in JP-A No. 6
No. 0-206859 discloses a resin composition with excellent thermal adhesive properties. However, as mentioned above, these resins need to be molded into a film in a molten state, and there are problems such as difficulty in coating thin films with complex shapes. In addition, blending an Epoquin compound with a polyester resin is known, for example, in Japanese Patent Application Laid-open No. 52-14184.
No. 4, JP-A-51-75729, JP-A-47-280
Although disclosed in Japanese Patent Application No. 92, etc., these compositions are coated with conventional resins in a solid state, that is, in a film form, molten state, or powder state, so they can be applied to various shapes and various adherends. There were definitely restrictions in that respect.

(Problems to be Solved by the Invention) In view of these circumstances, the present inventors have solved the problem of resin solution by dissolving or uniformly dispersing a crystalline or non-crystalline but poorly soluble resin with high molecular symmetry in an organic solvent. The purpose of the present invention is to provide a method for producing a resin solution that can be coated in a solid state and has excellent adhesion and coating film properties that cannot be achieved with conventional solvent-based resins.

(Means for Solving the Problems) That is, in the present invention, the main component of the dicarboxylic acid component is terephthalic acid, and the main component of the diol component is ethylene glycol, 1,4-butanediol and/or cyclohexalinemethanol. , solubility in solvent is 2g/10
Poorly solvent soluble polyester resin (A
) 20 to 80 parts and the main component of the dicarboxylic acid component is aromatic dicarboxylic acid, and the main component of the diol component has 2 to 2 carbon atoms.
Polyester resin (B) is an alkylene oxide adduct of 10 aliphatic glycols and alicyclic glycols and/or bisphenols and has a solubility in the solvent of 20 g/l 00 wsQ or more and/or 2 Compound (C) having 1 or more epoxy groups 80~
This is a method for dissolving or dispersing a poorly solvent-soluble polyester resin in a solvent, the method comprising melt-mixing 20 parts of the polyester resin and then mixing the mixture with the solvent.

The acid component of the poorly solvent-soluble polyester resin of the present invention contains at least 50 mol% of terephthalic acid, preferably 65 mol% or more, and the diol component contains ethylene glycol,
50 mol% or more of 1,4-butanediol and/or cyclohexaline methanol, preferably 60 mol%
or more, and has a reduced viscosity of 0.25 or more -Ll, particularly preferably 0.40 or more, and a t-1 acid value of 500 equivalents/10"
g or less, especially preferably 300! /106g or less is preferable. In the acid component, terephthalic acid is less than 50 mol%, or ethylene glycol with excellent molecular symmetry, 1
, 4-butanediol and/or chlorohexane dimetatool in an amount of less than 50 mol %, the improvement in adhesion and coating film properties that are the object of the present invention cannot be expected. The solubility of the polyester resin (A) of the present invention in a general-purpose solvent is 2 g
/l 00 mQ or less, preferably Ig/100+ml
! If it exceeds 2 g/100 mQ, the adhesiveness and physical properties of the coating film will be poor.

The polyester resin (B) of the present invention mainly contains an alkylene oxide adduct of an aromatic dicarboxylic acid and an aliphatic glycol having 2 to 10 carbon atoms, an alicyclic glyfur, and/or a bisphenol, and has a high solubility in organic solvents. 20g
/100- or more, and the aromatic dicarboxylic acid referred to here includes terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, etc. I can do it. The main acid component of the polyester resin (B) consists of these aromatic dicarboxylic acids, but in addition to these, 1,4-cyclohexanedicarboxylic acid, 3-cyclohexanedicarboxylic acid, 1゜2-cyclohexanedicarboxylic acid, etc. Alicyclic dicarboxylic acids or aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedioic acid can also be used in an amount up to 40 mol%. In addition, the glycols constituting the polyester resin (B) include ethylene glycol, propylene gelylcol, 1,3-propanediol, 1,4-
Butanediol, 1,5-bentanediol, 1,6-
Hexanediol, neopentyl glycol, 1,9-
Aliphatic glycols such as nonanediol, alicyclic glycols such as 1,4-cyclohexalinemethanol, 1,3-cyclohexalinemethanol, or bisphenol A
Alkylene oxide adducts of bisphenols such as ethylene side adducts of bisphenol F, ethylene oxide adducts of bisphenol F, ethylene oxide adducts of hydroquinone, and propylene oxide adducts of bisphenol A can be used as the main component.

It is desirable that the polyester resin (B) of the present invention has a solubility in an organic solvent of 20 g/100 g or more, and a glass transition temperature of 40° C. or more in consideration of the workability of melt mixing. Reduced viscosity is 0.2 or more, preferably 0.25
~0.60, and the acid value is preferably 300 equivalents/106 g or less. Solubility of polyester resin (B) 20g/100
．． If it is less than Q, the solubility will be poor when an organic solvent is added and dissolved after melting and mixing with the polyester resin (A) by heat, or even if it appears to be dissolved, it will aggregate immediately and the stability will deteriorate. becomes bad.

The epoxy compound (C) used in the present invention includes diglycidyl ethers of bisphenol compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, hydroquinone diglycidyl ether, and oligomers thereof. Diglycidyl ethers of basic acids such as terephthalic acid diglycidyl ester, orthophthalic acid diglycidyl ester, orthophthalic acid diglycidyl ester, and diglycidyl ethers of basic acids such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, etc. diglycidyl ethers and oligomers thereof.

Poorly solvent-soluble polyester resin used in the present invention (A
) and the easily solvent-soluble polyester resin (B) and/or epoxy compound (C) are (A)/((
B) + (C)) = 20-80/80-20 (weight ratio), (A)/(B)/(C) = 30-65/8
4-10/1-25 (weight ratio) is preferable.

If the amount of poorly solvent-soluble polyester resin (A) exceeds 80% by weight, it is difficult to obtain a stable resin solution;
If it is less than that, the adhesiveness and physical properties of the coating film will be poor. If the content of easily solvent-soluble polyester resin (B) exceeds 80%, superiority in adhesion and physical properties of the coating film will be poor. Moreover, if the epoxy compound (C) exceeds 80% by weight, the flexibility, which is a characteristic of polyester resin, will be lost.

Examples of organic solvents used in the present invention include aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone, methyl isonatyl ketone, and clohexanone isophorone, esters such as ethyl acetate and butyl acetate, and ethyl cellosolve. , ether-containing compounds such as cellosolve acetate, etc., and these organic solvents can also be used in combination.

The mixture of the polyester resin (A) and the polyester resin (B) and/or the epoxy compound (C) as used in the present invention may be cooled and crushed or powdered when mixed with a solvent. It may be in a molten state.

The present invention combines a poorly solvent-soluble polyester resin (A) with excellent adhesive properties and coating film properties into an easily soluble polyester resin (B).
Alternatively, the present invention provides a method in which the resin is melt-mixed with the Epoquin resin under heat, and then uniformly dissolved and dispersed in an organic solvent.

The obtained resin solution or dispersion can be applied as is to a plastic film such as polyethylene terephthalate, a metal thin film such as aluminum foil or copper foil, or a metal plate such as iron or tin plate, but if necessary, Known curing agents, inorganic pigments, flame retardants, etc. can also be added.

Examples of the curing agent include incyanate compounds, acid anhydride compounds, phenol resins, amide compounds, etc., and those commonly used for polyester or Epoquine resins can be selected. Further, as the pigment, various coloring pigments such as glue, titanium oxide, carbon black, and others can be used.

(Example) A specific explanation of ζ will be given below using examples.

Production Example In a reaction vessel equipped with a stirrer, condenser, and thermometer, 1358 parts of dimethyl terephthalate, 175 parts of dimethyl isophthalate, 680 parts of ethylene glycol, 1.4-
1000 parts of butanediol, 1 part of tetrabutyl titanate
．． 02 parts were charged and the transesterification reaction was carried out at 160-200"C over 4 hours. Then, 404 parts of sebacic acid was added and the esterification reaction was carried out at 200-250"C over a period of time.Next, the inside of the system was The pressure was gradually reduced to 5wmf1g over 40 minutes, and then a polycondensation reaction was carried out at 255°C for 50 minutes under a vacuum of less than 0.3ng.Finally, 19.2 parts of trimellitic anhydride was added. After reacting for 15 minutes, the resin was taken out.

As a result of analysis such as NMR, the obtained resin (A-1) was found to have 70 mol% of terephthalic acid, 9 mol% of isophthalic acid, 404 parts% of sebacic acid, 1 mol% of trimellitic acid, 39 mol% of ethylene glycol, 1 .4-butanediol 61 mol%
It had the following composition. Further, when the reduced viscosity was measured, it was 0.56, and the acid value was 88 equivalent/106 g. The polyester resin (A-1) was a crystalline polyester resin having a melting point of 154°C and a glass transition temperature of 10°C, as determined by DSC measurement. In a solubility test for organic solvents, the weight loss after immersing 25 g of resin in 100 J of methyl ethyl ketone at room temperature for 24 hours was measured, and the amount of dissolved resin was 0.5 g/100 ml or less.

As described above, polyester resins (A-2) to (A-3) and easily soluble polyester resins (B-1) to (B-3) shown in Table 1 were obtained using a method similar to the above production example.

Margin table below-1 Example 1 44 parts of polyester resin (A-1), 50 parts of polyester resin (B-1), 6 parts of Epikote 1001 (epoxy resin manufactured by Shell Chemical Co., Ltd.), and 0.3 part of triphenylphosphine were roughly mixed. After that, the mixture was melt-mixed in a twin-screw extruder at 160 to 200°C, air-cooled at room temperature, and then added to 20 parts of the mixed resin and 80 parts of methyl ethyl ketone, followed by dissolution with stirring at room temperature.

After 4 hours, a uniform resin solution was obtained, and the film thickness was about 4μ on a 25μ thick polyethylene terephthalate film.
After drying in a hot air dryer at 100° C. for 2 minutes, the sample was left to cool at room temperature and used as a test sample. The obtained coated film had almost no tackiness and had excellent workability.

Next, the coated surfaces were brought into contact with each other and heated for 2 seconds at 160°C.
After thermally bonding with a pressure of 1.3 kg/CTI, the adhesive strength was measured using a Tensilon UTM-III tensile tester manufactured by Toyo Baldwin, and it was found to be 1.3 kg/i.
It was 5--.

Example 2 Polyester resin (A-2) was prepared in the same manner as in Example 1.
54 parts, 28 parts of polyester resin (B-2), 18 parts of Epicoat '1804 (epoxy resin manufactured by Shell Chemical Co., Ltd.),
Triphenylphosphine 0.3 parts, Ionox 33
Melt and mix 0.2 parts of 0 (antioxidant manufactured by Shell Chemical),
After dissolving in methyl ethyl ketone, it was applied to a polyethylene terephthalate film to a thickness of about 4 μm and dried.

As in Example 1, no tackiness was felt at room temperature, and when peeled off and the adhesive strength was measured, it was 1.2 kg/l 5 square meters.

Comparative Example 1 20 parts of polyester resin (A-1) alone was added to 80 parts of polyester resin (A-1).
However, a stable solution could not be obtained.

Comparative Examples 2 and 3 Polyester resins (B-1) and (B-3) were each dissolved in methyl ethyl ketone to a solid content temperature of 20% by weight, applied to a polyethylene terephthalate film in the same manner as in Example 1, and dried.

The polyester resin (B-1) did not feel sticky at room temperature, but the peeling adhesive strength was low (0.44 kg/1
It was 5 mm. On the other hand, polyester resin (B-3)
The adhesive strength was 0.75 kg/15, which was a relatively good value, but it had the disadvantage of being sticky and difficult to work with.

Example 3 52 parts of polyester resin (A-3), polyester [1
11(B-2), 2 parts of bisphenol A diglycidyl ester, 0.3 parts of triphenylphosphine, and 0.3 parts of Ionox were melt-mixed at a maximum temperature of 220°C, and the solid content was reduced using cyclohexanone as a solvent. It was dissolved at a concentration of 20% by weight.

Next, 20 parts of hexamethoxymethylmelamine, 0.2 parts of p-toluenesulfonic acid, and 0.5 parts of polyethyl acrylate were added to 100 parts of the solid resin, and after mixing, 0.3 parts of polyethyl acrylate were added.
■Apply to a straw-thick cold-rolled steel plate to a film thickness of 15μ,
Heat curing was performed at 50°C for 1 minute. The pencil hardness of the resulting coating film was 2H, and the bending test was 2T.

Comparative Example 4 Except for the polyester resin (A-3) in Example 3,
When the same test as in Example 3 was conducted using 98 parts of polyester resin (B-2), the pencil hardness of the resulting coating film was 3T in the H11 peeling test.

(Effects of the Invention) According to the solvent dissolving method of the poorly solvent-soluble polyester resin of the present invention, since it is poorly soluble in conventional solvents, it can only be applied in a solid state such as a film, powder, or molten state. Since the previously unused polyester resin can be dissolved or uniformly dispersed in an organic solvent, it can be easily applied to the object to be coated at room temperature by coating, spray dipping, or other methods.

For this reason, it is possible to easily and uniformly form a polyester resin film or layer on the coated object-F, which has excellent adhesion and physical properties due to its poor solubility in solvents, but which had limitations in its application. be able to.

Therefore, the present invention dramatically expands the range of applications of polyester resins that are poorly soluble in solvents, and is of great industrial significance.

Claims (1)

[Claims] A poor solvent in which the main component of the dicarboxylic acid component is terephthalic acid, the main component of the diol component is ethylene glycol, 1,4-butanediol and/or cyclohexaline methanol, and the solubility in the solvent is 2 g/100 ml or less 20 to 80 parts of the soluble polyester resin (A) and the main components of the dicarboxylic acid component are aromatic dicarboxylic acids,
A polyester resin (B) in which the main component of the diol component is an alkylene oxide adduct of an aliphatic glycol having 2 to 10 carbon atoms, an alicyclic glycol, and/or a bisphenol, and the solubility in the solvent is 20 g/100 ml or more. and/or a poorly solvent-soluble polyester characterized by melt-mixing 80 to 20 parts of a compound (C) having two or more epoxy groups in one molecule, and then mixing the mixture with the solvent. Method of dissolving or dispersing resin in solvent.