JPH04164957A - Polyester resin composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain a solvent-base polyester resin compsn. giving a coating film excellent in physical and adhesive properties by dissolving or dispersing a specific crystalline polyester resin and a specific amorphous polyester resin in an org. solvent. CONSTITUTION:20-60wt.% crystalline polyester resin having an m.p. of 90-180 deg.C and 80-40wt.% amorphous polyester resin having a glass transition point of 30 deg.C or higher and being sol. in an org. solvent are melt mixed at above the m. p. of the crystalline resin and dissolved or dispersed homogeneously in an org. solvent, giving a polyester resin compsn. The crystalline resin is prepd. by using a dicarboxylic acid component contg. at least 50mol% terephthalic acid and a glycol component contg. at least 70mol% 2-10C linear alcohol and/or 1,4-cyclohexanedimethanol and addition-polymerizing 10-100mol% caprolactone. The amorphous resin is prepd. by using a dicarboxylic acid component contg. 80mol% arom. dicarboxylic acid and addition-polymerizing 5-60mol% caprolactone based on the whole dicarboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a solvent-based polyester resin composition that has excellent coating film properties and adhesive properties.

(Conventional technology) Polyester resin has traditionally been used in fibers, films, bottles,
Molding materials, paints, adhesives, various binders, etc.
It has been used in a wide range of applications.

However, broadly speaking, resins that are crystalline or amorphous, have high symmetry, high cohesive force, and are insoluble or poorly soluble in solvents are used in fibers, films, bottles, molding materials, powder coatings, etc.
Used in hot melt adhesives, resins that are amorphous, have low symmetry, and dissolve in general-purpose organic solvents are used in applications such as solvent-based paints, adhesives, various binders, and clear coatings.

(Problem to be solved by the invention) In general, poorly soluble resins have high intermolecular cohesive force, heat resistance,
It has excellent properties such as solvent resistance and coating properties, but due to the lack of a suitable medium, it can only be molded in the molten state, making it difficult to apply a thin and smooth film for coating or adhesive applications. was difficult. On the other hand, conventionally known solvent-soluble resins are amorphous and have weaker intermolecular cohesion than the former, so there is much room for improvement in Φ aspects such as adhesion and coating properties. It was left behind.

There have been many attempts to mix two types of polyester resins and give them new properties, for example,
Publication No. O-20Ei859 discloses a resin composition with excellent thermal adhesiveness. 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.

(Means for Solving the Problem) In view of these circumstances, the present inventors have made it possible to apply a resin solution by dissolving or uniformly dispersing a hardly soluble resin, especially a crystalline resin, in an organic solvent. We have discovered a resin composition that has excellent adhesion and coating film properties that cannot be achieved with conventional solvent-based resins.

That is, the present invention comprises 20 to 60% by weight of a crystalline polyester resin (A) having a melting point of 90 to 180°C, and a non-grade polyester (A) having a glass transition temperature of 30°C or higher and soluble in organic solvents.
B) 80 to 40% by weight of two types of polyester resins, which are melt-mixed at a temperature higher than the melting point of the polyester resin (A), and then dissolved or uniformly dispersed in an organic solvent. Method for producing polyester resin composition containing organic solvent and the polyester resin (A)
and (B) are dissolved or dispersed in an organic solvent.

The crystalline polyester resin (A) of the present invention has 90 to 18
It is preferable to have a melting point of 0° C. and a reduced viscosity of 0.25 or more, particularly preferably 0.40 or more. Melting point is 90
If the temperature is below 0.degree. C., the effect of crystallinity will be weakened by blending with non-quality resins, and no improvement in adhesion or physical properties of the coating film can be expected. Moreover, when the melting point is 180° C. or higher, crystallinity is high and a uniform dispersion cannot be obtained. Further, the dicarboxylic acid component of the polyester resin (A) contains at least 50 mol % of terephthalic acid, preferably 60 mol % or more, and the glycol component contains linear glycol having 2 to 10 carbon atoms and/or terephthalic acid. Contains 70 mol % or more, preferably 80 mol % or more of 4-cyclohexanedimethanol,
Moreover, it is preferable that 10 to 100 mol %, preferably 20 to 80 mol % of caprolactone be added and polymerized based on the total dicarboxylic acid components. If terephthalic acid is less than 50 mol% in the dicarboxylic acid component, or less than 70 mol% of linear glycol having 2 to 10 carbon atoms and/or 1,4 cyclohexane dimetatool in the glycol component, crystallinity is low. No improvement in adhesion can be expected. Further, when the number of moles of caprolactone added is less than 10 mol % based on the total dicarboxylic acid components, the solubility in the solvent is low and it is difficult to obtain a uniform dispersion. Also, 1o.

If it exceeds mol%, the solubility becomes too good and the adhesion and
The physical properties of the coating film will be poor.

Examples of dicarboxylic acids that can be used in combination with terephthalic acid in the polyester resin (A) include isophthalic acid, orthophthalic acid,
Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid and 4,4'-diphenyldicarboxylic acid; fats such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1°2-cyclohexanedicarboxylic acid; Examples include cyclic dicarboxylic acids and aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid. Glycols that can be used in combination with linear cane glycols having 2 to 1 carbon atoms and/or 1,4-cyclohexanedimethanol include propylene glycol, neopentyl glycol, 2-butyl-2-
Ether group-containing glycols such as ethyl-1,3-propanediol, 1,3-cyclohexanedimethanol, diethylene glycol, polyethylene glycol, ethylene oxide and/or propylene oxide adducts of bisphenol A, ethylene oxide and/or propylene oxide adducts of bisphenol A thing, 1.4-
Known glycols such as xylylene glycol, 1°3-xylylene glycol, and 1,2-xylylene glycol can be used. In addition, known polyhydric carboxylic acids such as trimellitic acid and pyromellitic acid, or polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol can also be used in combination within a range that does not impair the object of the present invention.

The non-grade polyester resin (B) of the present invention has a glass transition temperature of 30°C or higher, preferably 50°C or higher, is soluble in organic solvents, and is preferably 20g/100ml
It is preferable to have a solubility of 0.20 or more and a reduced viscosity of 0.20 or more, particularly preferably 0.35 or more. If the glass transition temperature of the polyester resin (B) is less than 30° C., workability during melt mixing will be poor, and adhesiveness and physical properties of the coating film will be poor. Furthermore, the dicarboxylic acid component of the polyester resin (B) contains at least 8 aromatic dicarboxylic acids.
0 mol% or more, the glycol component contains 60 mol% or more of an aliphatic glycol having 2 to 5 carbon atoms, an alicyclic glycol having 6 to 12 carbon atoms, and/or an aromatic ring-containing glycol, and the total dicarboxylic acid component It is preferable that 5 to 60 mol %, preferably 20 to 40 mol %, of caprolactone be addition-polymerized. In the dicarboxylic acid component, aliphatic glycol having 2 to 5 carbon atoms, 6 to 5 carbon atoms
If the content of the 12 alicyclic glycols and/or aromatic ring-containing glycols is less than 60 mol %, the glass transition temperature of the resin will be low. Further, if the number of moles of caprolactone added is less than 5 mol % based on the total dicarboxylic acid components, it is difficult to retain the crystalline resin in the solvent and a uniform dispersion cannot be obtained.

Moreover, when the content is 60 mol% or more, the glass transition temperature of the resin becomes low.

The aromatic dicarboxylic acids used in the polyester resin (B) include terephthalic acid, isophthalic acid, orthophthalic acid,
．． Examples include 6-naphthalene dicarboxylic acid and 4,4'-diphenyldicarboxylic acid. Examples of dicarboxylic acids that can be used in combination with these dicarboxylic acids include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclo-xanedicarboxylic acid, or succinic acid, Adipic acid,
Examples include aliphatic dicarboxylic acids such as azelaic acid, sebacic acid, and dodecanedioic acid. Examples of the aliphatic glycol having 2 to 5 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1°5-bentanediol, neopentyl glycol, and the like. As the alicyclic glycol having 6 to 12 carbon atoms, 1. 4-cyclohexanedimethanol, 1. Examples include 3-cyclohexanedimethanol, tricyclo[5.2.1.0"/6codecanedimethanol, etc.Aromatic ring-containing glycols include ethylene oxide and/or propylene oxide adducts of bisphenol A, ethylene oxide and / or prepylene oxide adduct, 1,4-xylylene glycol, 1,3-xylyleone glycol,
1.

Examples include 2-xylylene glycol. Glycols used in combination with these glycols include 1, 6-
Hexanediol, 1,9-nonanediol, 1.10
-Decanediol, 2-butyl-2-ethyl-1.3-
Examples include ether group-containing glycols such as 7" lopanediol, diethylene glycol, and polyethylene glycol. In addition, known polyhydric carboxylic acids such as trimellitic acid and pyromellitic acid, or glycerin, within a range that does not impair the purpose of the present invention. Polyhydric alcohols such as trimethylolpropane and pentaerythritol can also be used together.

The blending ratio of the crystalline polyester resin (A) and the non-grade polyester resin (B) used in the present invention is 20 to Et.
O/80-40 (polymerization ratio), preferably 30-50/
70 to 50 (polymerization ratio) is preferable. If the crystalline polyester resin (A) exceeds 60% by weight, it is difficult to obtain a stable dispersion, and if it is less than 20% by weight, the adhesiveness and physical properties of the coating film will be poor. In addition, crystalline polyester resin (
Addition polymerization of caprolactone to both A) and the non-grade polyester resin (B) significantly improves the stability of the solvent dispersion.

Examples of organic solvents used in the present invention include aromatic hydrocarbons such as toluene, toluene, and xylene; ketones such as methyl ethyl kent, methyl isobutyl ketone, cyclohexanone, and isophorone; esters such as ethyl acetate and butyl acetate; Examples include ether-containing compounds such as ethyl cellosolve and cellosolve acetate.

(Example) Specific examples will be described below using Examples, but the present invention is not limited to these in any way. Note that parts in the examples mean parts by weight.

Production Example 1 590 parts of dimethyl terephthalate, 1000 parts of 1,4-butanediol, and 0.52 parts of tetrabutyl titanate were charged into a reaction vessel equipped with a stirrer, condenser, and thermometer, and heated at 140 to 200"C for 3 hours. Then, 410 parts of sebacic acid was added, and 20 parts of sebacic acid was added.
The esterification reaction was carried out at 0 to 240"C over 1 hour. Next, the pressure in the system was gradually reduced to 5+HIIg over 30 minutes, and then the pressure was reduced to 255"C under a vacuum of 0.3mmHg or less.
The polycondensation reaction was carried out at ℃ for 45 minutes. Next, the pressure was returned to normal, and 231 parts of ε-caprolactone was added at 220° C. under a nitrogen stream, and after reacting for 90 minutes, the resin was taken out.

As a result of analysis such as NMR, the obtained resin (A-1) contained 60 mol% of terephthalic acid, 40 mol% of sebacic acid, and 1.4-
It had a composition of 40 mol% of a hydroxycaproic acid component to a polyester component of 100 mol% of butanediol. Further, this resin was a crystalline polyester resin having a reduced viscosity of 0.63, a melting point of 110°C, and a glass transition temperature of -41°C.

Hereinafter, crystalline polyester resins (A-2) to (A-5) and 8-soluble polyester resins (B-1) to (B-5) shown in Table-1 were obtained by a method similar to Production Example 1 above. .

Example 1 After roughly mixing 40 parts of polyester resin (A-1) and 80 parts of polyester resin (B-1), they were melt-mixed in a twin-screw extruder at 160 to 200°C, and after air cooling at room temperature, 30 parts of the mixed resin
1 part was added to 56 parts of toluene and 14 parts of methyl ethyl ketone, and the mixture was dissolved at room temperature with stirring. After 4 hours, a homogeneous resin solution (C-1) was obtained. This solution was applied onto a polypropylene film (50 μm) to a film thickness of 20 μm and dried in a hot air dryer at 100° C. for 30 minutes, resulting in a non-tacky coating. This coating film was peeled off from the polypropylene film, cut into strips with a width of 15mm, and fixed on a cardboard holder to a length of 30mm to prepare a test sample. When the tensile strength of this sample was measured using a Tensilon type tensile tester, the elongation at break was 420.
%, breaking strength 190 kg/CJ 1 initial elastic modulus 2
000 kg/cJ.

Examples 2 to 5 Two types of polyester resins were blended as shown in Table 2 and dissolved in the same manner as in Example 1, resulting in resin dispersions or solutions (C-2) to (C -5) was obtained. The physical properties of these dry coating films are shown in Table 2.

Comparative Example 1 Dissolution was carried out in the same manner as in Example 1 using 70 parts of polyester resin (A-1) and 30 parts of polyester resin (B-1), but a stable solution was not obtained and solidified. Ta(
D-1).

Comparative Examples 2 to 6 When 2W polyester resin was blended as shown in Table 2 and dissolved in the same manner as in Example 1, dispersions or solutions (D-2) to (D-6) were obtained. However, (D
-4) was solidified in the same way as (D-1). The physical properties of these dry coating films are shown in Table 2.

(Effect of the invention) The present invention melts and mixes a crystalline polyester resin (A) with excellent adhesiveness and coating film properties with an easily soluble polyester (B) when heated, and uniformly dissolves and disperses it in a growing solvent. The resulting resin composition can be used as a substrate such as 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 tinplate. Forms a uniform coating by applying it to the material. The coating film obtained in this way has good adhesion, mechanical properties, and
Excellent heat resistance and solvent resistance.

Taking advantage of these advantages, the resin composition of the present invention can contain single or known curing agents (for example, incyanate compounds, acid anhydrides, epoxy compounds, melamines, etc.), inorganic pigments (for example, silica, titanium oxide, carbon It is useful as paints, adhesives, coatings, etc. when used in combination with black, various other colored pigments, etc.), flame retardants, etc.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] [1] 50 mol% or more of the dicarboxylic acid component consists of terephthalic acid, and 70 mol% or more of the glycol component consists of linear glycol having 2 to 10 carbon atoms and/or 1,4-
Crystalline polyester resin (A) 20-6 consisting of cyclohexanedimethanol and addition-polymerized with 10-100 mol% of caprolactone based on the total dicarboxylic acid
0% by weight and 80 mol% or more of the dicarboxylic acid component is aromatic dicarboxylic acid, and 60 mol% or more of the glycol component is aliphatic glycol having 2 to 5 carbon atoms and 6 to 12 carbon atoms.
of alicyclic glycol and/or aromatic ring-containing glycol, and 5 to 60% of total dicarboxylic acids.
Amorphous polyester resin (B) having a glass transition temperature of 30°C or higher and soluble in an organic solvent, obtained by addition polymerization of mol% of caprolactone, and 80 to 40% by weight of the non-crystalline polyester resin (B) is dissolved or dispersed in an organic solvent. A polyester resin composition. [2] 20 to 60% by weight of a crystalline polyester resin (A) with a melting point of 90 to 180°C, and 80% by weight of an amorphous polyester (B) with a glass transition temperature of 30°C or higher and soluble in organic solvents.
~40% by weight are melt-mixed at a temperature higher than the melting point of the polyester resin (A), and then dissolved in an organic solvent or
A method for producing a polyester resin composition characterized by producing a uniformly dispersed state.