JPH10237285A - Polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin compsn. excellent in resistance to drawdown. SOLUTION: This compsn. comprises a polyester resin (A) which is produced by reacting an acid component contg. 80-100mol% arom. dicarboxylic acid and its ester-forming deriv. with a glycol component and has an intrinsic viscosity [η] (in an equimolar mixture of phenol and tetrachloroethane, at 25 deg.C) of 0.5dl/g or higher and a compd. (B) which has 3-30 glycidyl groups and an epoxy equivalent of 50-350g/eq.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition having excellent drawdown resistance and excellent mechanical properties, heat resistance, light transmittance, surface light selection, chemical resistance and the like.

[0002]

2. Description of the Related Art Extrusion blow molding has a feature that a hollow structure can be obtained by low pressure, and is widely used for containers.

However, in injection molding, a molten resin is directly injected into a mold at high speed and high pressure, whereas in extrusion blow molding, the molten resin has to be exposed to the outside air for several tens of seconds. For this reason, the parison is easily affected by external factors, and there is a problem in molding stability such as a variation in thickness distribution in a large molded product.

On the other hand, polyester resins are used in beverage bottles and cosmetic containers because of their excellent mechanical properties, gas barrier properties and chemical resistance. Solid-state polycondensation has been carried out to increase the pressure. However, these methods have low production efficiency and cannot avoid the increase in cost, and are not industrially and economically effective methods, and have excellent drawdown resistance not based on the solid-state polycondensation method. Polyester resins have been desired.

As a polyester resin suitable for extrusion blow molding, a method in which the resin is made amorphous by copolymerization to form the resin at a low temperature, and a method in which a bisphenol A type trifunctional hydroxyethoxy compound is contained in the polyester (Japanese Patent Application Laid-Open No. Hei 8- No. 208818) has been proposed,
In the case of the method, the melt viscosity at the extrusion temperature is insufficient, so that the drawdown is large and the shaping is difficult. In the case of the method, even if the drawdown property is improved to some extent, the impact resistance is insufficient and the molding is difficult. There was a problem that a satisfactory product could not be obtained.

An object of the present invention is to obtain a polyester resin having excellent drawdown resistance.

[0007]

In view of such circumstances, the present inventors have conducted intensive studies on the drawdown resistance of polyester resins and as a result, introduced a specific crosslinkable component in order to increase the melt viscosity of polyester resins. By doing so, it has been found that a resin with improved drawdown resistance and transparency can be obtained, and the present invention has been achieved.

[0008] The gist of the present invention is to provide aromatic dicarboxylic acids and their ester-forming derivatives at 80 to 1
It consists of an acid component and a glycol component containing
Polyester resin (A) having an intrinsic viscosity [η] of 0.5 [dl / g] or more as measured in a mixed solvent of phenol / tetrachloroethane at a temperature of 0 ° C. and epoxy having 3 to 30 (glycidyl) groups The equivalent weight is 50 to 350 (g / e
q) The polyester resin composition comprising the compound (B).

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyester resin (A) used in the present invention comprises an acid component containing at least 80 to 100 mol% of an aromatic dicarboxylic acid and an ester-forming derivative thereof, and a glycol component. And the intrinsic viscosity [η] measured in a mixed solvent of equal amounts of styrene / tetrachloroethane is 0.5 or more.

As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, naphthalene-1,4- or 2,2
6-dicarboxylic acid, anthracenedicarboxylic acid, 4,4
'-Diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid and the like, and examples of their ester-forming derivatives include alkyl esters and aryl esters.

The polyester resin used in the present invention comprises:
It is preferable that the aromatic dicarboxylic acid component is contained in an amount of at least 80 mol%, more preferably at least 85 mol%, of all the acid components. If the amount of the aromatic dicarboxylic acid component is less than 80 mol%, the mechanical strength and productivity of the molded article tend to decrease.

As an acid component other than the aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an ester-forming derivative thereof may be contained in the entire acid component in an amount of less than 20 mol%, preferably less than 15 mol%. This is 20
If the content is more than mol%, the mechanical strength of the molded article may be reduced. Examples of the aliphatic dicarboxylic acid used in the present invention include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, 1,3-cyclohexanedicarboxylic acid, and the like.

The polyester resin used in the present invention can be copolymerized with a glycol component other than ethylene glycol as a glycol component for imparting color tone, transparency, heat resistance, impact resistance and the like. Ethylene glycol must be contained in all glycol components in an amount of 50 mol% or more, preferably 70 mol% or more. This is because, if the content of ethylene glycol is less than 50 mol%, a decrease in polymerization reactivity in the resin production stage occurs, and it becomes difficult to obtain a resin having a desired degree of polymerization. This is because a problem occurs and it is not preferable.

As glycol components other than ethylene glycol, diethylene glycol, 1,4-butanediol, triethylene glycol, propylene glycol,
1,6-hexanediol, neopentyl glycol,
It can contain cyclohexanediol, cyclohexanedimethanol, an alcohol component represented by the following formula, and ethylene oxide adducts of these derivatives.

[0015]

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[0016]

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[0017]

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The polyester resin used in the present invention comprises:
It can also contain trivalent or higher polyhydric carboxylic acids and polyhydric alcohols. Specific examples include trimellitic acid,
Polyvalent carboxylic acids such as pyromellitic acid and their anhydrides, trimethylolpropane, pentaerythritol,
And polyhydric alcohols such as glycerin.

The polyester resin used in the present invention preferably has an intrinsic viscosity [η] (measured at 25 ° C. in a mixed solvent of phenol / tetrachloroethane at an equivalent weight) of 0.5 or more. If it is less than 0.5, the viscosity is low, and it is difficult to cool the strand, and the loss at the time of pelletizing becomes large. For the purpose of the present invention, it is preferably in the range of 0.5 to 0.8.

The polyester resin (A) used in the present invention can be produced by a known direct polymerization method or transesterification method.

The compound (B) used in the present invention is 3 to 3
It has 0 glycidyl groups and has an epoxy equivalent of 5
0 to 350 (g / eq). If the number of glycidyl groups is less than 3, there is no effect in improving the drawdown property, and if it exceeds 30, the storage stability of the compound (B) itself tends to decrease.

The compounding amount of the compound (B) is preferably in the range of 4 × 10 ^{−5 to} 6 × 10 ⁻² (mol%) with respect to the polyester resin (A).

If the amount is less than 4 × 10 ⁻⁵ mol%, there is no effect on the improvement of the drawdown resistance, and if it exceeds 6 × 10 ⁻² mol%, gelation occurs and the surface appearance deteriorates. Or the resin tends to yellow.

Specific examples of the compound (B) used in the present invention include novolak type epoxy resins such as phenol novolak, o-cresol novolak, and DPP novolak.
Examples include polyfunctional epoxy resins such as trishydroxyphenylmethane type and tetraphenylolethane type, vinyl copolymers containing glycidyl acrylate, and monomers such as 1,3,5-triglycidyl isocyanurate.

Various resins and additives can be added to the polyester resin composition of the present invention as needed. Examples thereof include polycarbonate, ABS resin, polyamide, polyolefin, resin such as polymethyl methacrylate, silica, talc, kaolin, inorganic particles such as calcium carbonate,
Examples include pigments such as titanium oxide and carbon black, ultraviolet absorbers, release agents, antistatic agents, and flame retardants.

The polyester resin composition of the present invention can be produced by extrusion molding of hollow containers such as bottles, parts such as pipes and tubes, direct blow molded articles, extruded sheets, plates, blown films, laminate coatings and the like. It can be used for applications. In particular, direct blow molded article applications are preferred.

The molded article obtained from the polyester resin composition of the present invention can be subjected to various known processing treatments in order to further impart specific performance. For example,
Irradiation of ultraviolet rays, α-rays, β-rays, γ-rays or electron beams, corona treatment, plasma irradiation treatment, flame treatment, etc., coating, laminating of resin such as vinylidene chloride, polyvinyl alcohol, polyamide, polyolefin, or metal Vapor deposition and the like.

[0028]

EXAMPLES The present invention will be specifically described with reference to examples.

The melt viscosity was evaluated by using a Capillograph and measuring the viscosity when extruded at 270 ° C. and a shear rate of 600 [1 / sec].

The drawdown resistance was evaluated by using a Capillograph and measuring the number of seconds required for the strand length to reach 400 mm when extruded at 270 ° C. and a shear rate of 60 [1 / sec].

The impact resistance was evaluated at 23 ° C. and 200 μm.
m], a load of 300 [g] was dropped on the sheet, and the height at which 80% of the test pieces were not broken and the height at which 80% of the test pieces were broken were measured at corners of 10 [cm].

The appearance of the molded product was evaluated by visually observing a 200 [μm] sheet.

The chemical resistance was evaluated at 23 ° C. at 200 μm.
m] The surface of the sheet was rubbed with acetone, and the change in appearance was visually evaluated.

Examples 1-5 Diamondite MA-521H ([η] = 0.78) manufactured by Mitsubishi Rayon Co., Ltd. and various polyfunctional glycidyl compounds (Epicoat 157S: bisphenol A type novolak (oiled shell epoxy) (stock)
Epoxy equivalent: 200 (g / eq), glycidyl group number 6, Epicoat 180S: o-cresol type novolak (manufactured by Yuka Shell Epoxy Co., Ltd.), epoxy equivalent 210 (g / eq), glycidyl group number: 7 , GMA40
% Modified polystyrene: glycidyl methacrylate / styrene copolymer), epoxy equivalent 320 (g / eq), glycidyl group number 28) in the ratio [wt%] shown in Table 1, and melt-mixed with a twin-screw extruder. The melt viscosity was measured by a capillograph.

Further, a sheet having a thickness of 200 μm was obtained by a T-die method. Table 1 shows the evaluation results of the resin composition.

Example 6 A mixture of diamondite MA-580 ([η] = 0.57) manufactured by Mitsubishi Rayon Co., Ltd. and Epicoat 157S 0.5 [% by weight] manufactured by Yuka Shell Epoxy Co., Ltd. was used. After melt-mixing with an extruder, the melt viscosity was measured by a capillograph. Further, a sheet having a thickness of 200 μm was obtained by a T-die method. Table 1 shows the evaluation results of the resin composition.

(Example 7) 0.5 wt% of Epicoat 157S manufactured by Yuka Shell Epoxy Co., Ltd. was blended with Diamond Night KR-560 ([η] = 0.78) manufactured by Mitsubishi Rayon Co., Ltd. After melt-mixing, the melt viscosity was measured by a capillograph. Further, a sheet having a thickness of 200 μm was obtained by a T-die method. Table 1 shows the evaluation results of the resin composition.

Comparative Example 1 Diamond Night MA-521H
Table 2 shows the evaluation results.

Comparative Example 2 Diamond Night MA-521
1.0 wt% of a bifunctional glycidyl compound, Epicoat 1010 (bisphenol A type bifunctional epoxy, epoxy equivalent 3000 (g / eq), glycidyl group number 2) manufactured by Yuka Shell Epoxy Co., Ltd. After melt-mixing with a machine, the melt viscosity was measured by a capillograph. Further, a sheet having a thickness of 200 μm was obtained by a T-die method. Table 2 shows the evaluation results of the resin composition.

Comparative Example 3 Diamond Night MA-521H
Was blended with 1.0% by weight of trimellitic anhydride and melt-mixed with a twin-screw extruder, and the melt viscosity was measured by a capillograph. Further, a sheet having a thickness of 200 μm was obtained by a T-die method. Table 2 shows the evaluation results of the resin composition.

[0041]

[Table 1]

Note) B1: Epicoat 157S B2: Epicoat 180S B3: GMA-modified polystyrene A1: MA521H A2: MA580 A3: KR560

[0043]

[Table 2]

Note) B4: Epicoat 1010 B5: Trimellitic anhydride A1: MA521H

[0045]

Industrial Applicability The polyester resin composition of the present invention has excellent impact resistance, particularly excellent surface impact strength, without using conventional solid-state polymerization, and impairs the processability, heat resistance and chemical resistance of polyester. Direct blow-molded products such as hollow containers such as bottles, pipes, and parts such as tubes, extruded sheets, plates, blown films, laminates
It has an excellent drawdown resistance and can stably mold a molded product by an extrusion molding method such as tocoating.

Claims (1)

[Claims] An intrinsic viscosity [η] comprising an acid component containing 80 to 100 mol% of an aromatic dicarboxylic acid and an ester-forming derivative thereof and a glycol component, and measured at 25 ° C. in a phenol / tetrachloroethane equivalent solvent mixture. Is 0.5 [dl / g] or more.
And a compound (B) having an epoxy equivalent of 50 to 350 (g / eq) having 3 to 30 (glycidyl) glycidyl groups.