JP5262373B2 - Polyester resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition capable of achieving softening while maintaining transparency by mixing a specific plasticizer with a polyester resin containing a diol unit having a cyclic acetal skeleton. <P>SOLUTION: The polyester resin composition having flexibility while keeping its transparency is obtained without problems such as whitening of the resin and bleeding of a plasticizer when an ester composed of a p-hydroxybenzoic acid and a 1-22C aliphatic alcohol and/or an acetylated monoglyceride are/is mixed as a plasticizer in a polyester resin containing dicarboxylic acid units and diol units, wherein a content of diol units having a cyclic acetal skeleton is 1-60 mol%. The polyester resin composition having flexibility while keeping its transparency can be widely applicable to various fields such as a film, a sheet, and an injection molded product equally to a vinyl chloride resin. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a polyester resin composition containing a diol unit having a cyclic acetal skeleton, and more particularly to a polyester resin composition excellent in flexibility, compatibility, moldability, etc. as a substitute for a halogen-based vinyl resin. More specifically, the present invention relates to a polyester resin composition obtained by blending a specific ester plasticizer with the polyester resin and capable of softening a film, a sheet, and an injection-molded body while being transparent.

  Polyester, especially polyethylene terephthalate (hereinafter sometimes referred to as “PET”) is a resin that is well-balanced in mechanical performance, solvent resistance, fragrance retention, recyclability, etc. It is used in large quantities in the center. However, since PET has high crystallinity, when it is attempted to produce a molded article or sheet having a thickness, whitening occurs due to crystallization, and transparency is impaired. Moreover, since the glass transition temperature of PET is about 80 ° C., high heat resistance and transparency are required, such as products used in automobiles, packaging materials for import / export, packaging materials for retort processing and microwave heating. It was not available for use.

  On the other hand, polyethylene naphthalate (hereinafter sometimes referred to as “PEN”), which is a transparent polyester resin having a chemical structure well similar to that of PET, is a polyester in which the dicarboxylic acid unit of PET is a naphthalene dicarboxylic acid unit. It is possible to process almost the same moldings (bottles, etc.) as possible, and has the possibility of recycling. Since PEN has a rigid molecular structure, it has features that are superior to PET in terms of heat resistance (glass transition temperature of about 110 ° C.), gas barrier properties, etc., but is very expensive. Similarly, since the crystallinity is high, there is a drawback that when a thick molded body or sheet is manufactured, whitening occurs due to crystallization and transparency is impaired.

  Therefore, low crystalline polyester resins such as modified PET partially copolymerized with 1,4-cyclohexanedimethanol and modified PET partially modified with isophthalic acid are used for applications requiring transparency. However, the glass transition temperature of these resins is around 80 ° C., and the heat resistance has not been improved as compared with PET.

  Polyester resins containing a diol having a cyclic acetal skeleton (for example, Patent Document 1 and Patent Document 2) are polyester resins that have improved heat resistance of PET and modified PET while having high transparency, and require transparency and heat resistance. It is possible to use it for a certain purpose.

  On the other hand, halogen-based vinyl resins typified by vinyl chloride resins or copolymers thereof are hard and brittle as they are, but soft vinyl halide resins can be added by adding appropriate plasticizers and other additives in appropriate amounts. As a composition, it is used for various molding applications.

  In particular, a soft vinyl chloride resin-based composition can freely control the required hardness and softness by changing the amount of plasticizer added, so it can be used for molding materials such as sheets, flooring materials, toys, automobile interiors, and entrances. It has been widely used for building materials such as refrigerators and home appliances such as refrigerators.

  However, since these vinyl chloride resins generate chlorine-based gas when they are burned and disposed of, in recent years, conversion to non-halogen-based resins is required from the viewpoint of environmental protection.

  Polyester resin is one of the alternatives for vinyl halide resin. Polyester resin represented by PET in particular has high hardness and excellent moldability, processability, coating suitability, etc., but compared with vinyl chloride resin. Thus, the compatibility with the plasticizer is low, and it cannot be used as widely as the vinyl chloride resin due to problems such as turbidity (whitening) of the resin and bleeding out of the plasticizer.

  Several plasticizers have been proposed and disclosed for the purpose of solving these problems, but no satisfactory one has been obtained yet.

  For example, as a method for softening amorphous polyester, plasticizers such as aliphatic dicarboxylic acid alkyl ether esters and polyethylene glycol fatty acid esters have been disclosed (Patent Document 3), but the transparency is not sufficient, and the surface is softened. There are problems such as bleeding out of the plasticizer.

  As ester plasticizers for polyester resins, those specifying acid value, hydroxyl value and volatilization loss are disclosed (Patent Document 4), but even if these are used, compatibility with polyester resins is poor, resin whitening, There are problems such as bleeding out of plasticizers.

  Among the phthalate ester plasticizers, dibutyl phthalate, ethyl phthalethyl glycolate, etc. have relatively good compatibility with polyester resins containing aromatic carboxylic acids, but they tend to volatilize because of their low boiling point and remain in the resin. It is difficult to use because problems with aging such as control, flexibility, and workability always occur.

JP 2003-182014 A JP 2002-69165 A JP 2000-290415 A JP 7-292223 A

  In view of the circumstances as described above, the object of the present invention is to add a specific plasticizer to a polyester resin containing a diol unit having a cyclic acetal skeleton, so that there is no problem such as whitening of the resin and the flexibility remains transparent. It is another object of the present invention to provide a polyester resin composition that can be used in a wide range of fields such as a film, a sheet, and an injection-molded product as in the case of vinyl chloride resin.

  As a result of intensive studies, the present inventors have found that by adding a specific plasticizer to a polyester resin containing a diol unit having a cyclic acetal skeleton, the compatibility is good and the composition is transparent and excellent in flexibility. Reached.

That is, the present invention relates to 2-hexyl-1-decyl-p in 100 parts by weight of a polyester resin containing a diol unit containing a dicarboxylic acid unit and a diol unit and having a diol unit having a cyclic acetal skeleton in an amount of 1 to 60 mol%. -It is a polyester resin composition which is obtained by adding 5 to 70 parts by weight of hydroxybenzoate and has excellent flexibility while maintaining transparency because of good compatibility between the resin and the plasticizer.

  Since the polyester resin composition of the present invention is excellent in compatibility between the polyester resin and the plasticizer, and has excellent flexibility while maintaining transparency, for example, a film, a sheet, an injection molded article, a flooring material, It becomes possible to replace conventional soft vinyl chloride resin-based compositions such as toys, automobile interior materials, building materials, coating agents, and paint applications.

The present invention is described in detail below. The polyester resin used in the polyester resin composition of the present invention contains 1 to 60 mol% of a diol unit having a cyclic acetal skeleton in the diol unit. The diol unit having a cyclic acetal skeleton is preferably a unit derived from a compound represented by the following general formula (1) or (2).
R ¹ , R ² , and R ³ are each independently an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and 6 to 10 carbon atoms. Represents a hydrocarbon group selected from the group consisting of aromatic hydrocarbon groups. As the compounds of the general formulas (1) and (2), 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, or 5-methylol-5-ethyl-2- (1,1-dimethyl-2-hydroxyethyl) -1,3-dioxane is particularly preferred.

  In addition, the diol unit other than the diol unit having a cyclic acetal skeleton is not particularly limited, but ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol Aliphatic diols such as propylene glycol and neopentyl glycol; polyether diols such as polyethylene glycol, polypropylene glycol and polybutylene glycol; 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2- Decahydronaphthalene diethanol, 1,3-decahydronaphthalene diethanol, 1,4-decahydronaphthalene diethanol, 1,5-decahydronaphthalene diethanol, 1,6-decahydronaphthalene Cycloaliphatic diols such as dimethanol, 2,7-decahydronaphthalene diethanol, tetralin dimethanol, norbornane dimethanol, tricyclodecane dimethanol, pentacyclododecane dimethanol; 4,4 ′-(1-methylethylidene ) Bisphenols such as bisphenol, methylene bisphenol (bisphenol F), 4,4′-cyclohexylidene bisphenol (bisphenol Z), 4,4′-sulfonyl bisphenol (bisphenol S); alkylene oxide adducts of the above bisphenols; hydroquinone , Aromatic dihydroxy compounds such as resorcin, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylbenzophenone; Alkylene oxide adducts of hydroxy compounds can be exemplified. Ethylene glycol, diethylene glycol, trimethylene glycol, 1,4-butanediol and 1,4-cyclohexanedimethanol are preferable from the viewpoint of mechanical performance and economical efficiency of the polyester resin of the present invention, and ethylene glycol is particularly preferable. The exemplified diol units can be used alone or in combination.

  The dicarboxylic acid unit of the polyester resin used in the polyester resin composition of the present invention is not particularly limited, but succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid Aliphatic dicarboxylic acids such as acid, cyclohexanedicarboxylic acid, decanedicarboxylic acid, norbornanedicarboxylic acid, tricyclodecanedicarboxylic acid, pentacyclododecanedicarboxylic acid; terephthalic acid, isophthalic acid, phthalic acid, 2-methylterephthalic acid, 1,4 Examples include aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and tetralindicarboxylic acid. From the viewpoint of mechanical performance and heat resistance of the polyester resin of the present invention, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 2,7- Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid are preferred, and terephthalic acid, 2,6-naphthalenedicarboxylic acid, and isophthalic acid are particularly preferred. Among these, terephthalic acid is most preferable from the viewpoint of economy. The illustrated dicarboxylic acids can be used alone or in combination.

The polyester resin composition of the present invention contains an ester composed of p-hydroxybenzoic acid and an aliphatic alcohol having 1 to 22 carbon atoms, and / or an acetylated monoglyceride. From the viewpoint of compatibility with the polyester resin, the aliphatic alcohol may have 1 to 22 carbon atoms, more preferably 1 to 20 carbon atoms, and most preferably 1 to 18 carbon atoms. Specific examples include 2-hexyl-1-decanol and 2-ethylhexanol. Esters such as 2-hexyl-1-decyl-p-hydroxybenzoate, 2-ethylhexyl-p-hydroxybenzoate, and / or acetylated monoglyceride obtained from these glycerol diacetomonolaurate, glycerol diacetomono (C ₈ , C ₁₀ ) An ester can be preferably used. Plasticizers are not limited to those listed above. Exepearl series, Vinicizer series, Trimex series, Leodor series, Emazol series, Emanon series, Excel as listed in the Kao Ester Products catalog Series, Homotex series, Coconado series, Rikenmar series manufactured by Riken Vitamin Co., Ltd., Poem series, and Actor series can be used, as long as they are compatible with polyester resin and can be softened. It is not restricted to these, Moreover, these can also be used independently and multiple can also be used together.

  The addition amount of the plasticizer is 5 to 70 parts by weight, preferably 6 to 60 parts by weight, and more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the polyester resin. If the added amount of the plasticizer exceeds 70 parts by weight, the hardness is remarkably lowered, the bleedout of the plasticizer becomes severe, the blocking problem occurs, or the transparency is lowered due to the precipitation of the plasticizer. There is. Moreover, if the addition amount is less than 5 parts by weight, the flexibility of the polyester resin is insufficient.

  The method of adding the plasticizer used in the present invention is not particularly limited, but the method of adding the plasticizer to the polyester resin in a molten state before being extracted from the polymerization kettle in the polyester resin polymerization step, the polyester resin is pelletized. A method of blending a plasticizer later, a method of impregnating and blending a finely pulverized polyester resin with a plasticizer, a method of melt-kneading the blended product with an extruder or the like, a polyester resin melted using an extruder or the like A method of adding a plasticizer to (a side feed method) is employed.

  A known apparatus can be used for mixing and kneading the polyester resin and the plasticizer. For example, a tumbler, a high speed mixer, a nauter mixer, a ribbon blender, a mixing roll, a kneader, an intensive mixer, a single screw extruder, a twin screw Examples thereof include a mixing and kneading apparatus such as an extruder. Moreover, liquid mixing apparatuses, such as a gate mixer, a butterfly mixer, a universal mixer, a dissolver, and a static mixer, can also be used. Further, a resin containing a high concentration of plasticizer and a polyester resin can be mixed by the above method and apparatus.

The melt viscosity of the polyester resin of the present invention is in the range of 100 to 5000 Pa · s when measured at a measurement temperature of 240 ° C. and a shear rate of 100 s ⁻¹ . If the melt viscosity is in the above range, it can be easily adjusted to a desired viscosity with a plasticizer according to the purpose, and a polyester resin having excellent moldability can be obtained. For example, by appropriately selecting the kind, combination, addition amount, and the like of the plasticizer, it is possible to impart arbitrary flexibility while maintaining transparency.

  The glass transition temperature of the polyester resin of the present invention is preferably 85 to 120 ° C, more preferably 90 to 120 ° C, and most preferably 95 to 120 ° C. By setting the glass transition temperature within the above range, it is possible to obtain a molded article having excellent heat resistance.

  The film obtained from the polyester resin composition of the present invention is, for example, a film having a thickness of 100 μm, having a total light transmittance of 80% or more, a haze value of 15% or less, and an elastic modulus in a tensile test of 1.5 GPa or less. When the total light transmittance is less than 80%, the transparency is inferior, and when the haze value is more than 15%, the turbidity becomes severe and the transparency is also inferior. If the elastic modulus in the tensile test is greater than 1.5 GPa, sufficient flexibility cannot be obtained.

  The polyester resin composition used in the present invention includes a light stabilizer, an ultraviolet absorber, an antioxidant, a heat stabilizer, a lubricant, an extender, a flame retardant, a pigment, a foaming agent, an antifogging agent, an antifungal agent, and an antibacterial agent. , Matting agent, drying regulator, antistatic agent, anti-settling agent, surfactant, flow improver, drying oil, waxes, filler, colorant, reinforcing agent, surface smoothing agent, leveling agent, curing reaction accelerator Various additives such as these and molding aids can be added. In addition, resins such as polyolefin, polyester, polyamide, polycarbonate, acrylonitrile resin, vinyl chloride resin, vinyl acetate resin, polyacrylic acid, polymethacrylic acid, polystyrene, ABS resin, polyimide, AS resin, and oligomers may be added.

  The polyester resin composition of the present invention is not limited to these, but is molded by various methods such as injection molding, extrusion molding, hollow molding, compression molding, powder molding, calendar molding, thermoforming, It can be used in various applications such as extruded molded products, sheet molded products, unstretched films, stretched films, injection blow bottles, direct blow bottles, and foams. In particular, since the composition of the present invention has good processability, it can be processed at a relatively low temperature such as 150 to 200 ° C. For this reason, calendar molding can also be performed, and since the temperature is low, decomposition of the resin and the plasticizer hardly occurs. The composition of the present invention can be formed into a film or sheet and used for various applications.

  Although the thickness of the sheet | seat of this invention is decided according to a use, the kind of resin which forms a layer, the number of layers, etc., it is normally 10 micrometers-10 mm. Moreover, thickness changes with uses, for example, it is 0.1-1 mm in the sheet | seat for foodstuffs, and it is used by the thickness of 1-40 mm in thick material sheets, such as a building material and goods display.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by these examples.

The raw materials used in the examples and comparative examples are shown below.
2-hexyl-1-decyl-p-hydroxybenzoate: manufactured by Kao Corporation, trade name: EXCEPARL HD-PB
・ Glycerin diacetomonolaurate: manufactured by Riken Vitamin Co., Ltd., trade name: Riquemar PL-012
Glycerin diacetoxy mono _{(C 8,} C ₁₀₎ ester: Riken Vitamin Co., Ltd., trade name: Liquemal PL-019

〔Evaluation method〕
Next, the evaluation method of the film in a present Example and a comparative example is as follows.
(1) Elastic modulus The elastic modulus is 10 mm wide using a tensile tester (model V1-C) manufactured by Toyo Seiki after conditioning the film of 100 μm for 48 hours in an atmosphere of 23 ° C. and 50% relative humidity. The measurement was performed at a speed of 50 mm / min.
(2) Total light transmittance and haze value The total light transmittance and haze value are determined according to JIS-K-7105 and ASTM D1003, after conditioning a 0.8 mm thick multilayer sheet for 48 hours, 23 ° C., and relative humidity 50 % Atmosphere. The measuring apparatus used is a fog value measuring apparatus (model: COH-300A) manufactured by Nippon Denshoku Industries Co., Ltd.

[Production of polyester resins (A-1) and (A-2)]
Charged terephthalic acid and ethylene glycol in the amounts shown in Table 1 into a 150 liter polyester resin production system equipped with a packed column rectification column, a partial condenser, a full condenser, a cold trap, a stirrer, a superheater, and a nitrogen introduction pipe The esterification reaction was carried out by a conventional method. Ethylene glycol for depolymerization and germanium dioxide in the amounts shown in Table 1 were added to the obtained ester, and depolymerization was performed at 225 ° C. under a nitrogen stream. After reacting for 3 hours while distilling off the water produced, ethylene glycol was distilled off at 215 ° C. and 13.3 kPa. Tetra-n-butyl titanate, potassium acetate, triethyl phosphate, and SPG described in Table 1 were added to the obtained ester, and the reaction was performed at 225 ° C. and 13.3 kPa for 3 hours. The resulting ester was heated and depressurized, and finally subjected to a polycondensation reaction at 270 ° C. and high vacuum (300 Pa or less), and when the predetermined melt viscosity was reached, the reaction was terminated and the polyester resin (A-1) , (A-2) was obtained.
In addition, the meaning of the abbreviation in a table | surface is as follows.
PTA: terephthalic acid SPG: 3,9-bis (1,1-dimethyl-2-hydroxyethethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane EG: ethylene glycol GeO2: Germanium dioxide, TBT: Tetra-n-butyl titanate, AcOK: Potassium acetate, TEP: Triethyl phosphate

The evaluation methods of the polyester resins (A-1) and (A-2) are as follows.
(1) Ratio of diol units having a cyclic acetal skeleton The ratio of diol units having a cyclic acetal skeleton in a polyester resin is calculated from ¹ H-NMR measurement and peak area ratio by dissolving 20 mg of a polyester resin in 1 g of heavy chloroform. did. The measuring apparatus used JNM-AL400 by JEOL Co., Ltd., and measured it at 400 MHz.
(2) Glass transition temperature The glass transition temperature of the polyester resin is DSC / TA-50WS manufactured by Shimadzu Corporation. About 10 mg of a sample is placed in an aluminum non-sealed container, and the temperature rising rate in a nitrogen gas (30 ml / min) airflow is 20 The glass transition temperature was measured at a temperature of ° C / min and the temperature changed by ½ of the difference in baseline before and after the transition of the DSC curve.
(3) Molecular weight (number average molecular weight Mn, weight average molecular weight Mw, molecular weight distribution Mw / Mn)
Polyester resin (2 mg) was dissolved in 20 g of chloroform, measured by gel permeation chromatography (GPC), and calibrated with standard polystyrene as Mn and Mw / Mn. GPC was measured by connecting TOSOH 8020 manufactured by Tosoh Corporation with two columns GMHHR-L manufactured by Tosoh Corporation and one TSK G5000HR and measuring the column temperature at 40 ° C. As an eluent, chloroform was flowed at a flow rate of 1.0 ml / min, and measurement was performed with a UV detector.
(4) The melt viscosity is measured using Toyo Seiki Capirograph 1C (capillograph), temperature: 240 ° C., preheating time: 1 min, nozzle diameter: 1 mm, nozzle length: 10 mm, shear rate: 100 (1 / sec). went.

[Production of polyester resin composition]
After pulverizing the polyester resin (A-1) or (A-2), various plasticizers were blended and then melt-kneaded with an extruder to produce polyester resin compositions described in Tables 2 and 3.

[Method for producing film]
Using a non-vented 65 mm twin screw extruder equipped with a T-die, extrusion was performed at an extrusion temperature of 180 ° C. and a discharge rate of 60 kg / h to produce a 100 μm monolayer film.

[ Examples 1-2 and Reference Examples 1-2 , Comparative Examples 1-4]
The evaluation results of the film are shown in Tables 2 and 3.

  Since the polyester resin composition of the present invention is excellent in compatibility between the polyester resin and the plasticizer, flexibility can be obtained while maintaining transparency, so that the vinyl chloride resin composition can be substituted. The industrial significance of the present invention is great.

Claims (10)

5 parts of 2-hexyl-1-decyl-p-hydroxybenzoate is added to 100 parts by weight of a polyester resin which contains a dicarboxylic acid unit and a diol unit, and 1 to 60 mol% of the diol unit has a cyclic acetal skeleton. A polyester resin composition comprising -70 parts by weight. Polyester resin, measurement temperature 240 ° C., the melt viscosity measured at a shear rate of 100s ^-1 is 100~5000Pa · s, according to claim 1 glass transition temperature of the polyester resin is 85 to 120 ° C. Polyester resin composition. In the film having a thickness of 100μm made of the polyester resin composition, the total light transmittance of 80% or more, haze value of 15% or less, according to claim 1 elastic modulus in a tensile test is equal to or less than 1.5GPa or 2. The polyester resin composition according to 2. The polyester resin composition according to any one of claims 1 to 3 , wherein the diol unit having a cyclic acetal skeleton is a diol unit derived from a diol represented by the general formula (1) or the general formula (2).
(In the formula, R ¹ and R ² are each independently an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and 6 to 10 carbon atoms. Represents a hydrocarbon group selected from the group consisting of aromatic hydrocarbon groups.)
(In the formula, R ¹ is the same as above, R ³ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and 6 to 10 carbon atoms. Represents a hydrocarbon group selected from the group consisting of aromatic hydrocarbon groups of A diol unit having the cyclic acetal skeleton derived from 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, Or a polyester resin composition according to any one of claims 1 to 4 , which is a diol unit derived from 5-methylol-5-ethyl-2- (1,1-dimethyl-2-hydroxyethyl) -1,3-dioxane. object. The diol unit other than the diol unit having a cyclic acetal skeleton is a diol unit derived from one or more diols selected from ethylene glycol, diethylene glycol, trimethylene glycol, 1,4-butanediol and 1,4-cyclohexanedimethanol. The polyester resin composition in any one of Claims 1-5 . One or more dicarboxylic acids in which the dicarboxylic acid unit is selected from terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid the polyester resin composition according to any one of claims 1 to 6, which is a dicarboxylic acid unit derived from an acid. The film obtained from the polyester resin composition in any one of Claims 1-7. The sheet | seat obtained from the polyester resin composition in any one of Claims 1-7. An injection-molded product obtained from the polyester resin composition according to any one of claims 1 to 7 .