JP2010053244A - Polyethylene terephthalate resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyethylene terephthalate resin composition that has a smooth surface to stand practical use and high heat resistance when made into a molded product such as films, fibers, etc. <P>SOLUTION: The polyethylene terephthalate resin composition includes 0.02-0.3 wt.% of fullerene hydroxide based on the weight of the resin composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyethylene terephthalate resin composition containing a fullerene hydroxide. More specifically, the present invention relates to a polyethylene terephthalate resin composition having improved heat resistance during melting and capable of obtaining a polyethylene terephthalate film or polyethylene terephthalate fiber suitable as a heat resistant material.

Polyester resins including polyethylene terephthalate resin are widely used in various molding materials such as films and fibers because they have excellent moldability and mechanical properties.
In particular, a polyester resin is used as a molding material for a wide range of applications. However, since the polyester resin is once melted and then processed into a desired molded product shape, it is exposed to high-temperature conditions during melting. At that time, deterioration due to heat may occur, and excellent characteristics such as deterioration of mechanical characteristics after molding may be deteriorated. Therefore, the polyester resin is strongly desired to have improved heat deterioration resistance such that the heat deterioration at the time of melting is small.

  Films made of polyester resin are used in a wide range of applications, including various packaging material films. When polyester films are used for packaging material films, for example, metals for enhancing sterilization and gas barrier properties. In many cases, they are exposed to high-temperature conditions such as vapor deposition, and at that time, deterioration due to heat still occurs, so there is a strong demand for improvement in heat-resistant deterioration. Further, even in the case of fibers made of polyester, there is a strong demand for improving heat resistance deterioration in applications exposed to high temperature conditions such as polyethylene terephthalate fibers for tire cords.

  In order to meet such requirements, in recent years, nanocomposites, in which nanomaterials are dispersed in thermoplastic resins, have been studied as a method for improving the heat resistance of thermoplastic resins.

  For example, in Japanese Patent Application Laid-Open No. 2004-182768, a crystalline thermoplastic resin contains fullerenes having an average particle size in a specific range in an amount of 0.25% by weight or more, thereby improving the heat resistance of the thermoplastic resin. It has been proposed that the temperature, specifically, the 10% weight loss temperature of the thermoplastic resin composition can be made higher. JP-A-2004-75933 discloses that dispersibility is improved when a fullerene derivative having a reactive group such as a hydroxyl group is used as the fullerene.

  However, when trying to mold polyethylene terephthalate containing fullerene as disclosed in these, the glass transition temperature and melting point are low, although the 10% weight loss temperature is high, and it has remarkable characteristics that can be widely used industrially. Did not have.

JP 2004-182768 A JP 2004-75933 A

  The object of the present invention is to solve the above-mentioned problems of the prior art, and has excellent heat resistance such as high glass transition temperature and melting point inherent in polyethylene terephthalate while having excellent heat deterioration resistance during melt molding. Another object of the present invention is to provide a polyethylene terephthalate resin composition capable of providing a molded article such as a film or fiber having high heat deterioration resistance and heat distortion resistance.

As a result of repeated studies to solve the above problems, the present inventors have found that when polyethylene terephthalate is selected from among polyesters and fullerene hydroxide is selected as the fullerene, the fullerene hydroxide is extremely uniformly dispersed. However, in Patent Document 1, excellent heat resistance deterioration is expressed in a very small amount of less than 0.25% by weight, which is considered to have no effect of improving heat resistance, and since it is extremely small, glass transition temperature, melting point, etc. The present inventors have found that there is no adverse effect on heat-resistant modification that decreases.
Thus, according to the present invention, there is provided a polyethylene terephthalate resin composition to which a fullerene hydroxide is added in an amount of 0.02 to 0.24% by weight.

  Furthermore, according to the present invention, as a preferred embodiment of the present invention, the copolymerization amount of diethylene glycol is 0.1 to 3.0% by weight based on the weight of polyethylene terephthalate, and the fullerene hydroxide is a C60 skeleton and There is also provided a polyethylene terephthalate resin composition having at least one of having a C70 skeleton and having 6 to 12 hydroxyl groups per molecule of fullerene hydroxide.

  The polyethylene terephthalate resin composition of the present invention can improve thermal degradation during melting without impairing other properties by containing a very small amount of hydroxylated fullerene, resulting in the production of films, fibers, and the like. The molded product can be provided with high heat resistance such as excellent heat deterioration resistance and heat deformation resistance.

Hereinafter, the present invention will be described in detail.
[Polyethylene terephthalate resin composition]
The polyethylene terephthalate resin composition of the present invention needs to contain a fullerene hydroxide in the range of 0.02 to 0.24% by weight based on the weight of the resin composition. When the content is less than the lower limit, the effect of improving the heat resistance during melting by the fullerene hydroxide is poor. On the other hand, when the upper limit is exceeded, the amount of diethylene glycol, which is a by-product, increases during the polymerization reaction to uniformly disperse the fullerene hydroxide in the polyethylene terephthalate resin composition, resulting in glass rearrangement. A point, melting | fusing point, etc. fall and have a bad influence on heat-resistant deformation. A preferable content of the hydroxylated fullerene is 0.03 to 0.20% by weight, and further 0.05 to 0.15% by weight.

  In the polyethylene terephthalate resin composition of the present invention, the copolymerization amount of diethylene glycol is preferably 0.1 to 3.0% by weight based on the weight of polyethylene terephthalate. As described above, since diethylene glycol is increased by the fullerene hydroxide, it is technically difficult to make the copolymerization amount of diethylene glycol less than 0.1% by weight. On the other hand, when it exceeds 3.0% by weight, the glass transition point and melting point are exceeded. The heat resistance is likely to decrease because of the decrease in the temperature. The copolymerization amount of diethylene glycol is preferably 0.3 to 2.6% by weight, more preferably 0.8 to 2.0% by weight.

  The mechanism of the improvement in heat resistance during melting in the present invention is not clear, but it is thought that the fullerene hydroxide functions as a radical scavenger. Specifically, it is considered that radicals generated when the polyethylene terephthalate resin receives heat suppress the decomposition reaction by the function of the fullerene hydroxide as a scavenger.

By the way, when hydroxylated fullerene is added during the reaction of polyethylene terephthalate synthesis, the amount of copolymerization of diethylene glycol increases. This is presumably because the fullerene hydroxide acts as some kind of catalyst and diethylene glycol formation reaction occurs. It is preferable for maintaining the heat resistance of the polyethylene terephthalate resin composition that the diethylene glycol is copolymerized with polyethylene terephthalate to lower the glass transition point and the melting point, so that the copolymerization amount of diethylene glycol is within a specific range.
Therefore, by making the content of fullerene hydroxide and the copolymerization amount of diethylene glycol within the scope of the present invention at the same time, the heat resistance aimed at by the present invention can be obtained higher.

  The polyethylene terephthalate resin composition of the present invention may be composed only of polyethylene terephthalate, hydroxylated fullerene, and diethylene glycol, but various additives known per se as long as the effects of the present invention are not impaired. Etc. may be included. For example, in producing fibers and films, inert fine particles can be contained as a lubricant in order to improve winding properties and transportability. Examples of the inert fine particles include inorganic fine particles (for example, kaolin, plate boehmite, titanium oxide, calcium carbonate, silicon dioxide, etc.) containing the elements of Periodic Tables IIA, IIB, IVA, and IVB, silicone resins And fine particles made of a polymer having high heat resistance such as crosslinked polystyrene. When the inert fine particles are included in the polyethylene terephthalate resin composition, the average particle diameter of the fine particles is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.8 μm. The content of the inert fine particles is preferably 0.05 to 0.5% by weight, more preferably 0.1 to 0.3% by weight in the polyethylene terephthalate resin composition. Further, two or more kinds of inert particles having different kinds, shapes or sizes may be used in combination.

[polyethylene terephthalate]
First, the resin constituting the resin composition of the present invention is polyethylene terephthalate. The reason for this is not yet clear, but the same effect was not obtained even when the same study was conducted with polyethylene-2,6-naphthalate, which represents polyester as well as polyethylene terephthalate.

  The polyethylene terephthalate in the present invention is composed mainly of a terephthalic acid component, an ethylene glycol component, and a diethylene glycol component, and within a range not impairing the effects of the present invention, for example, 40 mol% or less, further 35 mol% or less, particularly It may be a polyethylene terephthalate copolymer in which a copolymer component other than a terephthalic acid component, an ethylene glycol component and a diethylene glycol component is copolymerized at a ratio of 5 mol% or less. Specific examples of copolymer components include succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and 5-sodium dicarboxylic acid as dicarboxylic acid components, and trimethylene glycol, propylene as glycol components. Examples include glycols, alkylene glycols such as 1,4-butanediol, and 1,4-cyclohexanedimethanol. In addition, these copolymerization components may use not only 1 type but 2 or more types together.

  The intrinsic viscosity of the polyethylene terephthalate in the present invention is preferably 0.4 dl / g to 0.8 dl / g at 35 ° C. in an orthochlorophenol solvent, more preferably 0.5 dl / g to 0.7 dl / g. It is. When the intrinsic viscosity is less than 0.4 dl / g, the mechanical strength required when the polyethylene terephthalate resin composition of the present invention is used for each product after being formed into a fiber or a film may be insufficient. On the other hand, when the intrinsic viscosity exceeds 0.8 dl / g, productivity at the time of melt kneading in the melt polymerization step and molding into a fiber or film may be impaired.

[Fullerene hydroxide]
The fullerene hydroxide in the present invention is a fullerene having a hydroxyl group introduced therein, and preferably has, for example, a C60 skeleton and / or a C70 skeleton. The fullerene hydroxide of the present invention may be either a hydroxylated fullerene in which a hydroxyl group is introduced into the C60 skeleton or a hydroxylated fullerene in which a hydroxyl group is introduced into the C70 skeleton, or both of them are mixed. The fullerene hydroxide is most preferably a hydroxylated fullerene having a hydroxyl group introduced into the C60 skeleton.

  Thus, by introducing a hydroxyl group into fullerene, when added to the polymerization system of polyethylene terephthalate, it can be charged in a state dissolved in ethylene glycol, and as a result, it can be dispersed in a polymer obtained very uniformly. And the effects of the present invention are maximized. The number of hydroxyl groups per molecule of the fullerene hydroxide in the present invention is preferably 6-12. When the number of hydroxyl groups is in the range of 6 to 12, when blended in polyethylene terephthalate, an effect of improving heat resistance is easily obtained.

[Method for producing polyethylene terephthalate resin composition]
The polyethylene terephthalate resin composition of the present invention can be produced by a conventionally known method for producing a polyethylene terephthalate resin composition, and if the content of the fullerene hydroxide satisfies the above range, the production method is particularly It is not limited.

  However, as a result of intensive studies by the present inventors, the dispersibility of the fullerene hydroxide in the polyethylene terephthalate resin is improved by adopting a production method as described below, which contributes to an improvement in heat resistance. Is further enhanced.

  Specifically, when producing terephthalic acid or an ester-forming derivative thereof and ethylene glycol by an esterification reaction or a transesterification reaction and a polycondensation reaction, any stage until the esterification reaction or the transesterification reaction is completed. Thus, there is provided a method for producing a polyethylene terephthalate resin composition in which 0.02 to 0.24% by weight of fullerene hydroxide is added based on the weight of the resin composition to be obtained.

  The reason why the dispersibility of the fullerene hydroxide is enhanced by the above production method is that, by adding the fullerene hydroxide during the reaction, the fullerene hydroxide is dissolved in the reaction solution, so that high dispersibility is obtained. It is thought that

  When the addition amount of the fullerene hydroxide is less than the lower limit, the effect of adding the fullerene hydroxide is small. On the other hand, when the addition amount exceeds the upper limit, the glass transition point and the melting point of the polyethylene terephthalate resin composition are lowered as described above. This causes adverse effects such as occurrence or aggregation of particles during addition, which deteriorates the surface properties of the molded product. A preferable addition amount is 0.03 to 0.20% by weight, and further 0.05 to 0.15% by weight.

  Furthermore, as an addition form of the fullerene hydroxide in the above production method, it is preferable to add it as an ethylene glycol solution having a fullerene hydroxide concentration of 0.05 to 0.5% by weight. When the fullerene hydroxide is added in the form of a solution in which ethylene glycol is dissolved in the above ratio, a high degree of dispersibility of the fullerene hydroxide can be achieved, and the effects of the fullerene hydroxide can be more easily expressed.

  Hereinafter, the present invention will be further described based on examples. Various physical property values and characteristics in the present invention are measured and defined as follows. In the present invention, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified.

(1) Thermal degradation (ΔIV)
100 g of the polyethylene terephthalate resin composition pellets obtained in the examples are dried at 170 ° C. for 3 hours, then melted at 300 ° C. in the air atmosphere, and held in a ring melt state for 10 minutes after melting. Thereafter, the polyethylene terephthalate resin composition in a molten state is taken out and rapidly cooled and solidified to obtain a melt-treated sample. The intrinsic viscosity of both the melt-treated sample and the untreated sample before the melt treatment is measured, and the difference between them is used as an index ΔIV of heat resistance during melting for 10 minutes. Moreover, the same measurement is repeated except that the holding time in the molten state is changed to 30 minutes, and the index ΔIV of the heat resistance during melting in 30 minutes is obtained. The smaller the ΔIV, the smaller the decrease in molecular weight due to the decomposition reaction during the melting process, and the better the heat resistance.

(2) Copolymerization amount of diethylene glycol in polyethylene terephthalate resin composition The resin was hydrolyzed with hydrazine, and the released diethylene glycol was analyzed by gas chromatography (Hewlett Packard 6990).

(3) Glass transition temperature (Tg) and melting point (Tm) of polyethylene terephthalate resin composition
Measurement was performed using a differential scanning calorimeter (DSC2920) manufactured by TAinstruments. A 10 mg sample is set in the apparatus, melted at 300 ° C. for 5 minutes, and then cooled in liquid nitrogen. The cooled sample was heated at a rate of 10 ° C./min. The temperature at which the endotherm in the glass transition was detected was defined as the glass transition temperature (Tg), the temperature was further increased and the crystallization exothermic peak was detected, and then the peak top temperature at which the crystal melting peak was detected was the melting point (Tm). And

(4) Intrinsic viscosity This is a value measured at 25 ° C. in orthochlorophenol. The unit is dl / g.

[Example 1]
(1) Fullerene hydroxide having 12 hydroxyl groups introduced per molecule in C60 skeleton (nanom spectra HX10-S manufactured by Frontier Carbon Co.) was used, and 0.46 of fullerene hydroxide was added to 99.6 parts of ethylene glycol. Part was added and stirred at room temperature for 4 hours to prepare a 0.4 wt% fullerene hydroxide / ethylene glycol solution.
(2) A mixture of 100 parts of dimethyl terephthalate and 70 parts of ethylene glycol is charged with 0.038 parts of manganese acetate tetrahydrate in a transesterification reaction kettle and gradually heated from 140 ° C. to 230 ° C. while being gradually heated. The transesterification was carried out while distilling methanol out of the system. During this time, using the fullerene hydroxide / ethylene glycol solution prepared in (1) above at 170 ° C., the reaction was continued by adding the fullerene hydroxide content in the polyethylene terephthalate resin composition to 0.1 wt%. After completion of the distillation of methanol, 0.017 part of trimethyl phosphate was added as a phosphorus compound to terminate the reaction. Subsequently, 0.030 part of the polymerization catalyst antimony trioxide was added after 5 minutes and heated to 240 ° C. to distill a part of ethylene glycol, and then the oligomer was transferred to the polycondensation reaction kettle. Thereafter, the reaction is terminated when the desired viscosity is reached at a final internal temperature of 290 ° C. while heating in a high vacuum according to a conventional method, and the strand is continuously extruded from the discharge part into a strand shape and cooled to about 3 mm. Granular pellets of the front and rear polyethylene terephthalate resin compositions were obtained. The intrinsic viscosity of this polymer was 0.62. The properties of the obtained polyethylene terephthalate resin composition are shown in Table 1.

[Comparative Example 1]
Except for not adding the fullerene hydroxide, the same operation as in Example 1 was performed to obtain granular pellets of a polyethylene terephthalate resin composition having an intrinsic viscosity of 0.62. The properties of the obtained polyethylene terephthalate resin composition are shown in Table 1.

[Examples 2 and 3 and Comparative Examples 2 and 3]
The same operation as in Example 1 was repeated except that the amount of the fullerene hydroxide in the composition was changed to the amount shown in Table 1. The properties of the obtained polyethylene terephthalate resin composition are shown in Table 1.

[Comparative Example 4]
(1) Fullerene hydroxide having 12 hydroxyl groups introduced per molecule in C60 skeleton (nanospectra HX10-S manufactured by Frontier Carbon Co.) is used, and 0.4 part of fullerene hydroxide with respect to 99.6 parts of ethylene glycol And stirred at room temperature for 4 hours to prepare a fullerene hydroxide / ethylene glycol solution having a concentration of 0.4 wt%.
(2) A mixture of 100 parts of dimethyl 2,6-naphthalene and 60 parts of ethylene glycol was charged with 0.030 parts of manganese acetate tetrahydrate in a transesterification kettle, and the temperature was gradually raised from 140 ° C to 230 ° C. The transesterification reaction was carried out while distilling the produced methanol out of the system. During this time, using the fullerene hydroxide / ethylene glycol solution prepared in (1) at 170 ° C., the addition amount of fullerene hydroxide was 0.1 wt.% Relative to the weight of the obtained polyethylene-2,6-naphthalate resin composition. The reaction was continued until the methanol was completely distilled, and 0.020 part of trimethyl phosphate was added as a phosphorus compound to terminate the reaction. Then, after 5 minutes, 0.024 part of the polymerization catalyst antimony trioxide was added and heated to 250 ° C. to distill a part of ethylene glycol, and then the oligomer was transferred to the polycondensation reaction kettle. Thereafter, the reaction is terminated when the desired viscosity is reached at a final internal temperature of 295 ° C. while heating in a high vacuum according to a conventional method, and is continuously extruded in a strand form from the discharge part, and cooled and cut to about 3 mm. Before and after, pellets of polyethylene-2,6-naphthalate resin composition were obtained. The intrinsic viscosity of this polymer was 0.62. Table 1 shows the properties of the obtained polyethylene-2,6-naphthalate resin composition.

[Comparative Example 5]
Except that the fullerene hydroxide was not added, the same operation as in Comparative Example 4 was repeated to obtain granular pellets of polyethylene-2,6-naphthalate resin composition having an intrinsic viscosity of 0.62 dl / g. Table 1 shows the properties of the obtained polyethylene-2,6-naphthalate resin composition.

  According to the present invention, it is possible to obtain a molded article such as a film or fiber having high heat resistance while having excellent surface flatness, in particular, a fiber for tire cord that requires high heat resistance, and surface flatness. It can be suitably used as a packaging material or a film for electronic materials that require high heat resistance, and its industrial value is extremely high.

Claims (2)

  A polyethylene terephthalate resin composition, wherein a fullerene hydroxide is added in a range of 0.02 to 0.24% by weight based on the weight of the resin composition.   The polyethylene terephthalate resin composition according to claim 1, wherein diethylene glycol is copolymerized in the range of 0.1 to 3.0% by weight based on the weight of polyethylene terephthalate.