JP2012041516A - Polyester-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester-based resin composition such as polybutylene terephthalate resin, polyethylene naphthalate resin and polycyclohexenedimethylene terephthalate resin, having a high rate of crystallization and stable melt viscosity.SOLUTION: A specific aliphatic carboxylic acid disodium salt having a melting point (by DSC at the rate of temperature increase of 20°C/min) of ≤330°C is mixed in an amount of 0.1-3 pts.mass based on 100 pts.mass of a polyester-based resin such as polybutylene terephthalate resin, polyethylene naphthalate resin and polycyclohexenedimethylene terephthalate resin and melt-kneaded. Above all, the one mixed and kneaded with azelaic acid disodium salt exhibits an excellent rate of crystallization and stable melt viscosity. A resin composition in which an ionomer resin, particularly 1-30 pts.mass of a resin of a sodium salt of a (meth)acrylic acid-modified polyethylenic ionomer is added to the polyethylene terephthalate-based resin composition shows further improvement in crystallization, stability of melt viscosity.

Description

The present invention relates to a polyester resin composition having a high crystallization rate and a stable melt viscosity.

Polyester resins such as polyethylene naphthalate resin (hereinafter abbreviated as PEN), polycyclohexene dimethylene terephthalate resin (hereinafter abbreviated as PCT) and the like have a low melting point (heat resistance), but are slow. The crystallization speed is not suitable for injection molding, and the market is stagnant. On the other hand, polybutylene terephthalate resin (hereinafter abbreviated as PBT) is currently used in a large amount in the field of injection molding because it has a high crystallization speed, but further improvement of the crystallization speed is desired.

Improvement of the crystallization speed of polyester resin has been studied for a long time until now, centering on polyethylene terephthalate resin (hereinafter abbreviated as PET). The metal salts (lithium, sodium, potassium salts, etc.) of organic carboxylic acids described in JP-B-48-4097, JP-B-48-4098, and JP-A-54-154552 have been known for a long time and are limited in crystallization speed. This is the cheapest and most effective technology. For example, a material obtained by blending approximately 1 to 3 parts by mass of sodium stearate or sodium benzoate with respect to 100 parts by mass of PET, and sufficiently melting and kneading the material, even if immediately quenched from 300 ° C., its differential scanning calorimeter (hereinafter referred to as “the differential scanning calorimeter”) A recrystallization peak (hereinafter abbreviated as Tcc) at the time of temperature rise (20 ° C./min) due to DSC is hardly observed. This means that almost all molecular chains to be crystallized have been crystallized. However, the melt viscosity of the composition is significantly reduced, and the mechanical strength (impact strength, etc.) of the product is not practical at all.
The present inventor previously found out that a specific aliphatic dicarboxylic acid disodium salt increases the crystallization speed without decreasing the melt viscosity with respect to PET (Japanese Patent Application No. 2010-013150). Publication).

Japanese Patent Publication No.48-4097 Japanese Patent Publication No.48-4098 JP 54-158452 A Japanese Patent Application No. 2010-013150

An object of the present invention is to provide a polyester-based resin composition such as PBT, PEN, and PCT having a high crystallization rate and a stable melt viscosity.

The present inventor previously found that a specific aliphatic dicarboxylic acid disodium salt increases the crystallization speed without reducing the melt viscosity with respect to PET. Thereafter, when further studies were conducted, it was found that the disodium aliphatic dicarboxylic acid salt exhibited the same effect on other semi-aromatic polyester resins such as PBT, PEN, and PCT, as in PET. Knowing it led to the present invention.

A specific aliphatic dicarboxylic acid disodium salt having a melting point by DSC of not more than 330 ° C. of 0.1 to 100 parts by mass of a semi-aromatic polyester resin such as PBT, PEN, PCT, etc. The polyester resin composition containing 3 parts by mass improves the crystallization rate. What blended 1-30 mass parts of ionomer resin with this polyester-type resin composition further improves the crystallization rate.
Details of the present invention will be described below.

The polyester resin referred to in the present invention is an aromatic dicarboxylic acid compound such as terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid, an alicyclic dicarboxylic acid compound such as cyclohexanedicarboxylic acid or cyclohexanedimethylenecarboxylic acid, ethylene glycol, propylene glycol. , A method of directly esterifying an aliphatic diol compound such as butanediol in the absence of a catalyst or in the presence of a catalyst, an aromatic dicarboxylic acid ester compound such as dimethyl terephthalate and an aliphatic diol compound such as ethylene glycol in the presence of a catalyst. A polymer having a low degree of polymerization is prepared by a method of transesterification, and then the polymer and a catalyst (for example, a germanium compound or an antimony compound) of this low degree of polymerization are appropriately heated (for example, about 240 to 310 ° C.) Under reduced pressure (e.g. 0. Torr or melt polycondensation kept below under vacuum), obtained by solid phase polycondensation thereafter.

Such a polyester-based resin may be a homopolymer, or a copolymer in which a part of the dicarboxylic acid component and / or diol component is substituted with a copolymer component. Among the copolymer components, the dicarboxylic acid component is an aromatic dicarboxylic acid [isophthalic acid, phthalic acid; alkyl-substituted phthalic acid such as methyl terephthalic acid, methyl isophthalic acid; naphthalenedicarboxylic acid (2,6-naphthalenedicarboxylic acid] 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, etc.); 4,4′-diphenyldicarboxylic acid, diphenyldicarboxylic acid such as 3,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethane Diphenoxyethanedicarboxylic acid such as dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylethanedicarboxylic acid, diphenyldicarboxylic acid such as diphenylketone dicarboxylic acid]; alicyclic dicarboxylic acid (for example, cyclohexanedicarboxylic acid, An alicyclic dicarboxylic acid having about 8 to 12 carbon atoms such as oxahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, and hymic acid, or a derivative thereof; an aliphatic dicarboxylic acid (for example, succinic acid, adipic acid, Pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, hexadecanedicarboxylic acid, aliphatic dicarboxylic acid having about 4 to 20 carbon atoms such as dimer acid) or derivatives thereof. The derivatives of dicarboxylic acid include derivatives capable of forming an ester, for example, lower alkyl esters such as dimethyl ester, acid halides such as acid anhydride and acid chloride, and the like. These copolymerizable dicarboxylic acids or derivatives thereof can be used alone or in combination of two or more. The proportion of these copolymer components is usually 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less of the total dicarboxylic acid component. Preferred dicarboxylic acid copolymerization components include aromatic dicarboxylic acids (phthalic acid, isophthalic acid, etc.), C _6-12 aliphatic dicarboxylic acids (adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.), etc. .

As a diol component as a copolymerization component, aliphatic diol [trimethylene glycol, propylene glycol, 1,3-butanediol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, octanediol, decanediol, etc. Or branched C _3-12 alkylene diol, etc.], polyoxy C _2-4 alkylene glycol (for example, diethylene glycol, triethylene glycol, polyoxyethylene glycol, ditetramethylene glycol, polytetramethylene ether glycol, dipropylene glycol, Tripropylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diols [for example, cyclohexanediol, 1, -Cyclohexanedimethanol, hydrogenated bisphenol A, etc.], aromatic diol [hydrophenol, resorcin and other dihydroxybenzene, naphthalenediol, bisphenol A, dihydroxydiphenyl ether, bisphenols such as 2,2'-bis (4-hydroxyphenyl) sulfone And adducts (eg, diethoxylated bisphenol A) obtained by adding alkylene oxide (C _2-4 alkylene oxide such as ethylene oxide or propylene oxide) to bisphenols]. These copolymerization components can be used alone or in combination of two or more. The proportion of these copolymer components is usually 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less of the total diol component. Preferred diol copolymerization components include C _3-6 alkylene glycol (such as linear or branched alkylene glycol such as propylene glycol and 1,4-butanediol), and an oxyalkylene unit having about 2 to 4 repetitions. Polyoxy C _2-4 alkylene glycol (such as diethylene glycol). Specific preferred examples of the polyester resin include PBT, PEN, PCT and the like.

The intrinsic viscosity (or intrinsic viscosity) of the polyester resin can be appropriately selected, and is, for example, about 0.4 to 1.5 dl / g at 30 ° C. in a solvent hexafluoroisopropanol. If the intrinsic viscosity is small, the resin properties cannot be obtained effectively. If the intrinsic viscosity is too large, the melt viscosity is high, the fluidity is lowered and the moldability is impaired.

Next, the aliphatic dicarboxylic acid disodium salt referred to in the present invention has a melting point (peak temperature) of 330 ° C. or less at a heating rate of 20 ° C./min by DSC.
Specifically, disodium azelate, disodium brassylate, disodium tetradecanedioate, disodium pentadecanedioate, disodium hexadecanedioate, disodium heptadecanedioate, disodium octadecanedioate, disodium nonadecanedioate Eicosane diacid disodium and the like. Preferred are disodium azelaate, disodium braillate, and disodium eicosane diacid. Among them, disodium azelaate is particularly preferable.
The compounding amount of the aliphatic dicarboxylic acid disodium salt is 0.1 to 3 parts by mass, preferably 0.15 to 2.5 parts by mass, and more preferably 0.2 to 100 parts by mass with respect to 100 parts by mass of the polyester resin. 2 parts by mass. If the blending amount is less than 0.1 parts by mass, the effect of crystallization is small, and if it exceeds 3 parts by mass, the effect is saturated and the melt viscosity is remarkably lowered.

Furthermore, the ionomer resin referred to in the present invention is a polymer having a side structure having a metal salt in a polymer chain and a molecular structure that forms an ionic bond between polymer molecules. In general, in addition to partially neutralized metal salts of random, block, and graft copolymers of various vinyl monomers and acidic vinyl monomers such as (meth) acrylic acid and styrene sulfonic acid, carboxylic acid groups and sulfonic acid groups are added. There are partially metal neutralized products of condensation polymers composed of dicarboxylic acids, diols, and diamine compounds contained in the molecule. Specifically, a polyethylene ionomer resin composed of ethylene and (meth) acrylic acid, a polypropylene ionomer resin composed of propylene and (meth) acrylic acid, a polystyrene ionomer composed of styrene and styrenesulfonic acid, acrylonitrile, Examples include acrylonitrile / styrene / butadiene (ABS) -based ionomers composed of styrene, butadiene and (meth) acrylic acid or styrenesulfonic acid. Among these ionomer resins, a polyethylene ionomer resin composed of ethylene and (meth) acrylic acid is preferable. The proportion of the monomer containing the metal salt in the ionomer resin is preferably from 0.01 to 10 mol%. Moreover, although the kind of metal is an alkali metal or an alkaline earth metal, sodium is most preferable. The compounding amount of the eye monomer resin is 1 to 30 parts by mass, preferably 2 to 20 parts by mass with respect to 100 parts by mass of the polyester resin. If it is less than 1 part by mass, the effect of improving the crystallization and impact strength of the composition is small, and if it exceeds 30 parts by mass, the melt viscosity and the flexural modulus decrease, which is not preferable.

The polyester resin composition of the present invention comprises a polyester resin, disodium salt of a specific aliphatic dicarboxylic acid and an ionomer resin, which are dry blended, and then a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, It is manufactured by melt kneading using a general resin kneading apparatus such as a screw extruder. Among these, it is preferable to produce using a twin screw extruder.

In addition to other polyester resins such as polyethylene terephthalate resin, polylactic acid resin, polyarylate resin, and liquid crystal polyester resin, the polyester-based resin composition of the present invention may include a polyamide resin, a polycarbonate resin, a polyoxy resin, if necessary. Methylene resin, polyphenylene oxyto resin, polyether sulfone resin, polyether ether ketone resin, polyamide imide resin, polyimide resin, polyethylene resin, polypropylene resin, polyethylene propylene copolymer resin, polystyrene resin, polybutadiene resin, acrylonitrile / butadiene / A styrene copolymer resin (ABS resin) or the like may be blended. The compounding quantity of these resin is 100 mass parts or less with respect to 100 mass parts of polyester-type resin, Preferably it is 50 mass parts or less.

Furthermore, the polyester resin composition of the present invention includes other known various crystal nucleating agents, crystallization accelerators (polyoxyethylene derivatives, etc.), antioxidants, weather resistance / light stabilizers, flame retardants, fillers (talc). , Mica, etc.), reinforcing agents (glass fibers, carbon fibers, whiskers, etc.), impact modifiers (impact improving polymers, elastomers, rubbers, etc.) and the like can be blended.

The polyester resin composition of the present invention can be applied to various automobile / electronic / electrical members, instruments, containers (blow bottles, etc.), films, sheets, fibers, etc. using molding methods such as injection molding, extrusion molding, and compression molding. Molded.
Next, although this invention is demonstrated in detail using an Example, this invention is not restrict | limited at all by these Examples.

(Measurement of melting point and heat of fusion (Tm, Hm), crystallization start temperature and heat of crystallization (Tc, Hc), recrystallization temperature and heat of recrystallization (Tcc, Hcc)) About 10 mg of sample is aluminum for DSC measurement Weigh accurately in a pan, melt PBT at 260 ° C, PEN and PCT at 300 ° C for 1 minute, transfer to hot water at 85 ° C, rapidly cool, and prepare a sample for DSC measurement. Using a differential scanning calorimeter (DSC6200) manufactured by Seiko Instruments Inc., the aluminum pan sample was heated at a rate of 20 ° C./minute from 50 ° C. to 260 ° C. for PBT, and 320 ° C. for PEN and PCT. , Tm and Hm were measured. Next, after maintaining PBT at 260 ° C. and PEN and PCT at 320 ° C. for 3 minutes, PEN is cooled at 10 ° C./minute, PCT is cooled at 20 ° C./minute, and Tc and Hc are measured. All were obtained from the peak temperature and area.
(Measurement of melt viscosity (MFR)) Using a hot air dried sample at 130 ° C. for 5 hours, using a high temperature melt indexer manufactured by Techno Seven, PBT is 250 ° C., PEN and PCT are 290 ° C., 2.16 kg load The measurement was performed according to JIS K7210.

(Adjustment of disodium azelaic acid (Aze-2Na)) After dissolving 12.8 g of sodium hydroxide (Wako Pure Chemical Industries, Ltd., reagent grade) in 100 g of water, 30 g of azelaic acid (Wako Pure Chemical Industries, Ltd., reagent grade) Charge and neutralize. The neutralized solution was evaporated and dried at 100 ° C., and then heat-treated at 330 ° C. for 10 minutes in a nitrogen stream. The obtained white solid was pulverized in a mortar to obtain 36 g of white powder. Tm = 298.2 ° C.
(Adjustment of dodecanedioic acid disodium (Dod-2Na)) 26.1 g of sodium hydroxide was dissolved in 500 g of water, and 75 g of dodecanedioic acid (Wako Pure Chemical Industries, Ltd., reagent grade) was gradually added to neutralize. After evaporating water to dryness at 100 ° C., the same experiment as Aze-2Na was performed to obtain a white powder. Tm = 344.5.degree.
[Examples 1 to 4, Comparative Examples 1 to 5]

With respect to 100 parts by mass of PBT (manufactured by Mitsubishi Chemical Corporation, Novadere 5020), PEN (manufactured by Teijin Ltd., Teonex TN8050SC), PCT (manufactured by Eastman Kodak Co., Ltd., 3879) dried at 120 ° C. for 5 hours with a hot air dryer. Aze-2Na, Dod-2Na, commercial disodium succinate (Wako Pure Chemical Industries, reagent special grade, Suc-2Na), sodium stearate (Wako Pure Chemical Industries, reagent special grade, Ste-Na), azelaic acid (Wa Kosei Pharmaceutical Co., Ltd., reagent grade, Aze), ionomer resin (Mitsui Chemicals, Himiran 1707), phenolic antioxidant (Adeka, AO-60), phosphorus antioxidant (Adeka, PEP- 36), a sulfur-based antioxidant (manufactured by Adeka Co., 412S) in a proportion shown in Table 1 and a twin-screw extruder (manufactured by Technobel Co., KZ) 15-30) using, PBT set temperature 240 ° C., and kneaded PEN, PCT set temperature 290 ° C., a screw rotation speed of 300 rpm, under the conditions of discharge rate 1 kg / hour. DSC and MFR were measured using the obtained pellets. The results are summarized in Table 2.

From the results of Tables 1 and 2, Aze-2Na of the present invention has an excellent crystallization speed and a stable melt viscosity (MFR) as compared with other known crystal nucleating agents, which are aliphatic (mono, di) carboxylic acid metal salts. ). Further, from the result of Example 4, it was observed that the compound containing the ionomer resin had a further excellent crystallization rate. This fact is a new discovery that cannot be known at all from the conventional known technical contents.

Claims (5)

Polyester in which 0.1 to 3 parts by mass of an aliphatic dicarboxylic acid disodium salt having a melting point (peak temperature) at a heating rate of 20 ° C./min in DSC of 330 ° C. or less is added to 100 parts by mass of a polyester resin -Based resin composition. The polyester resin composition which further mix | blended 1-30 mass parts of ionomer resin with respect to the polyester resin of Claim 1. A polyester resin composition, wherein the polyester resin according to claim 1 or 2 is a polybutylene terephthalate resin, a polyethylene naphthalate resin, or a polycyclohexene dimethylene terephthalate resin. A polypolyester resin composition in which the disodium salt of aliphatic dicarboxylic acid according to claim 1 or 2 is azelaic acid disodium salt. A polyester resin composition, wherein the ionomer resin according to claim 2 is a (meth) acrylic acid-modified polyethylene ionomer resin.