JP2012097163A - Polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film which uses a biomass ethylene glycol and is carbon-neutral.SOLUTION: A resin composition includes a polyester containing a diol unit and a dicarboxylic acid unit. In the polyester, the diol component unit is ethylene glycol derived from a biomass, and the dicarboxylic acid component unit is a petroleum-derived dicarboxylic acid. The polyester is contained in 50 to 95 mass% in the whole resin composition.

Description

  The present invention relates to a biomass polyester resin composition obtained from a plant-derived raw material, and more particularly to a resin composition containing a polyester using biomass-derived ethylene glycol as a diol component.

  Polyesters are widely used in various industrial applications because they are excellent in mechanical properties, chemical stability, heat resistance, transparency and the like and are inexpensive. Polyester is obtained by polycondensation of a diol unit and a dicarboxylic acid unit. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is obtained by esterifying ethylene glycol and terephthalic acid as raw materials. After the polycondensation reaction. These raw materials are produced from petroleum, which is a fossil resource, for example, ethylene glycol is produced industrially from ethylene and terephthalic acid is produced industrially from xylene.

  In recent years, with the growing demand for the establishment of a recycling-oriented society, the use of biomass has been attracting attention in the materials field, as it is desired to move away from fossil fuels as well as energy. Biomass is an organic compound photo-synthesized from carbon dioxide and water, and by using it, it is so-called carbon neutral renewable energy that becomes carbon dioxide and water again. In recent years, biomass plastics using these biomass as raw materials have been rapidly put into practical use, and attempts have been made to produce polyester, which is a general-purpose polymer material, from these biomass raw materials.

  For example, as a polyester using a biomass material, a polyester composed of isosorbide, terephthalic acid and ethylene glycol, which is one of biomass materials, has been proposed (Patent Document 1).

  Biomass ethanol obtained by fermenting starch and saccharides obtained from plants such as corn and sugarcane with microorganisms has been put into practical use, and ethylene glycol is industrially produced from this biomass ethanol via ethylene. Has also succeeded.

Special table 2002-512304 gazette

  The present inventors pay attention to ethylene glycol, which is a raw material of polyester, and instead of ethylene glycol obtained from conventional fossil fuel, polyester using plant-derived ethylene glycol as its raw material is obtained from conventional fossil fuel. The inventors obtained knowledge that polyesters produced using ethylene glycol and those inferior in physical properties such as mechanical properties can be obtained. The present invention is based on this finding.

  Accordingly, an object of the present invention is to provide a resin composition containing carbon neutral polyester using biomass ethylene glycol, such as a polyester produced from a raw material obtained from a conventional fossil fuel, and mechanical properties, etc. The object of the present invention is to provide a biomass-derived resin composition from which a polyester that is inferior in physical properties can be obtained.

The resin composition according to the present invention is a resin composition comprising a polyester comprising a diol unit and a dicarboxylic acid unit,
It is characterized by comprising 50 to 95% by mass of a polyester in which the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit is a dicarboxylic acid derived from fossil fuel, based on the entire resin composition. .

  In the embodiment of the present invention, the dicarboxylic acid derived from the fossil fuel is preferably terephthalic acid.

  In the embodiment of the present invention, it is preferable to further include an additive.

  In the aspect of this invention, it is preferable to contain the said additive 5-50 mass% with respect to the whole resin composition.

  In an aspect of the present invention, the additive is a plasticizer, an ultraviolet stabilizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering agent, an antistatic agent, a yarn friction reducing agent, a release agent. It is preferable that it is 1 type, or 2 or more selected from the group which consists of an antioxidant, an ion exchanger, and a coloring pigment.

  In the aspect of this invention, it is preferable that content of the carbon derived from biomass by a radioactive carbon (C14) measurement is 10-19% with respect to all the carbon in the said polyester.

  In this invention, the resin film which consists of the said resin composition is also provided.

  According to the present invention, in the resin composition, the polyester in which the diol component unit is biomass-derived ethylene glycol and the dicarboxylic acid component unit is petroleum-derived dicarboxylic acid is 50 to 95 mass based on the entire resin composition. %, It is possible to realize a carbon neutral polyester resin. In addition, the film made of the resin composition of the present invention is not inferior in terms of physical properties such as mechanical properties and the polyester film produced from the raw material obtained from the conventional fossil fuel, and can replace the conventional polyester film. .

  The resin composition according to the present invention includes a polyester composed of a diol unit and a dicarboxylic acid unit as main components, and uses biomass-derived ethylene glycol as the diol unit. A carbon neutral polyester resin can be realized by using a resin composition containing 50 to 95% by mass of a polyester containing a biomass-derived diol unit. Biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol. Therefore, polyester using biomass-derived ethylene glycol is not a polyester polymerized from a conventional fossil fuel-derived raw material. Therefore, the film made of the resin composition of the present invention is not inferior to the conventional polyester film in terms of physical properties such as mechanical properties. Hereinafter, the polyester contained in the resin composition will be described.

<Polyester>
The polyester contained in the resin composition according to the present invention comprises a diol unit and a dicarboxylic acid unit, and uses a biomass-derived ethylene glycol as the diol unit and a polycondensation reaction using a dicarboxylic acid derived from fossil fuel as the dicarboxylic acid unit. Is obtained.

  Biomass-derived ethylene glycol uses ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained from biomass ethanol by a conventionally known method, such as a method of producing ethylene glycol via ethylene oxide. Moreover, you may use commercially available biomass ethylene glycol, for example, the biomass ethylene glycol marketed from India Glycol can be used conveniently.

  The dicarboxylic acid unit of the polyester uses a dicarboxylic acid derived from fossil fuel. As the dicarboxylic acid, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and derivatives thereof can be used without limitation. Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid, and examples of the aromatic dicarboxylic acid derivative include lower alkyl esters of aromatic dicarboxylic acid, specifically methyl ester, ethyl ester, propyl ester, and butyl. Examples include esters. Among these, terephthalic acid is preferable, and dimethyl terephthalate is preferable as an aromatic dicarboxylic acid derivative.

  Specific examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid. And a chain or alicyclic dicarboxylic acid. Examples of the aliphatic dicarboxylic acid derivative include lower alkyl esters such as methyl ester, ethyl ester, propyl ester and butyl ester of aliphatic dicarboxylic acid, and cyclic acid anhydrides of aliphatic dicarboxylic acid such as succinic anhydride. Can be mentioned. Among these, adipic acid, succinic acid, dimer acid or a mixture thereof is preferable, and succinic acid as the main component is particularly preferable. As the derivative of the aliphatic dicarboxylic acid, methyl esters of adipic acid and succinic acid, or a mixture thereof are more preferable.

  These dicarboxylic acids can be used alone or in combination of two or more.

  The polyester contained in the resin composition according to the present invention may be a copolymer polyester obtained by adding a copolymer component as a third component in addition to the diol component and the dicarboxylic acid component. Specific examples of the copolymer component include a bifunctional oxycarboxylic acid, a trifunctional or higher polyhydric alcohol, a trifunctional or higher polyvalent carboxylic acid and / or an anhydride thereof, and 3 Examples include at least one polyfunctional compound selected from the group consisting of functional or higher oxycarboxylic acids. Among these copolymer components, a bifunctional and / or trifunctional or higher functional oxycarboxylic acid is particularly preferably used because a copolymer polyester having a high degree of polymerization tends to be easily produced. Among them, the use of a tri- or higher functional oxycarboxylic acid is most preferable because a polyester having a high degree of polymerization can be easily produced with a very small amount without using a chain extender described later.

  The polyester may be a high molecular weight polyester obtained by chain extending (coupling) these copolyesters. As the chain extender, a chain extender such as a carbonate compound or a diisocyanate compound can also be used. However, the amount of the chain extender is usually 100% by mole of all monomer units constituting the polyester, and a carbonate bond and a urethane bond. Usually, it is 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less.

  Specific examples of the carbonate compound include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, ethylene carbonate, diamyl carbonate, and dicyclohexyl. Examples include carbonate. In addition, carbonate compounds composed of the same or different hydroxy compounds derived from hydroxy compounds such as phenols and alcohols can be used.

  Specific examples of the diisocyanate compound include 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, and xylylene. Known diisocyanates such as range isocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate can be used.

  The polyester used in the present invention can be obtained by a conventionally known method in which the above-described diol unit and dicarboxylic acid unit are polycondensed. Specifically, after performing the esterification reaction and / or transesterification reaction of the dicarboxylic acid component and the diol component, a general method of melt polymerization such as a polycondensation reaction under reduced pressure, or an organic solvent It can be produced by a known solution heating dehydration condensation method using

  The amount of the diol used in producing the polyester is substantially equimolar with respect to 100 mol of the dicarboxylic acid or derivative thereof, but in general, during the esterification and / or transesterification reaction and / or the condensation polymerization reaction. Is used in excess of 0.1 to 20 mol%.

  The polycondensation reaction is preferably performed in the presence of a polymerization catalyst. The addition timing of the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added when the raw materials are charged, or may be added at the start of pressure reduction.

  Examples of the polymerization catalyst include compounds containing a Group 1 to Group 14 metal element excluding hydrogen and carbon in the periodic table. Specifically, at least one metal selected from the group consisting of titanium, zirconium, tin, antimony, cerium, germanium, zinc, cobalt, manganese, iron, aluminum, magnesium, calcium, strontium, sodium, and potassium. And compounds containing an organic group such as carboxylate, alkoxy salt, organic sulfonate, or β-diketonate salt, and inorganic compounds such as metal oxides and halides described above, and mixtures thereof. Of these, metal compounds containing titanium, zirconium, germanium, zinc, aluminum, magnesium and calcium, and mixtures thereof are preferred, and titanium compounds, zirconium compounds and germanium compounds are particularly preferred. In addition, the catalyst is preferably a compound that is liquid at the time of polymerization or that dissolves in an ester low polymer or polyester because the polymerization rate increases when it is melted or dissolved at the time of polymerization.

  The titanium compound is preferably a tetraalkyl titanate, specifically, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate, tetraphenyl titanate, tetracyclohexyl titanate, tetra Examples include benzyl titanate and mixed titanates thereof. In addition, titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titanium (diisoproxide) acetylacetonate, titanium bis (ammonium lactate) dihydroxide, titanium bis (ethylacetoacetate) diisopropoxide, titanium (triethanolaminate) ) Isopropoxide, polyhydroxytitanium stearate, titanium lactate, titanium triethanolamate, butyl titanate dimer and the like are also preferably used. Furthermore, titanium oxide and composite oxides containing titanium and silicon are also preferably used. Among these, tetra-n-propyl titanate, tetraisopropyl titanate and tetra-n-butyl titanate, titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titanium bis (ammonium lactate) dihydroxide, polyhydroxytitanium stearate , Titanium lactate, butyl titanate dimer, titanium oxide, titania / silica composite oxide (for example, product name: C-94 manufactured by Acordis Industrial Fibers), particularly tetra-n-butyl titanate, polyhydroxy titanium stearate , Titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titania / silica composite oxide (for example, Acordis Industrial Fiber) The product name manufactured by s company: C-94) is preferable.

  Specific examples of the zirconium compound include zirconium tetraacetate, zirconium acetylate hydroxide, zirconium tris (butoxy) stearate, zirconyl diacetate, zirconium oxalate, zirconyl oxalate, potassium potassium oxalate, and polyhydroxyzirconium. Examples include stearate, zirconium ethoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetra-n-butoxide, zirconium tetra-t-butoxide, zirconium tributoxyacetylacetonate and mixtures thereof. Further, zirconium oxide or a complex oxide containing, for example, zirconium and silicon may be used. Among these, zirconyl diacetate, zirconium tris (butoxy) stearate, zirconium tetraacetate, zirconium acetate acetate, zirconium ammonium oxalate, potassium potassium oxalate, polyhydroxyzirconium stearate, zirconium tetra-n-propoxy Zirconium tetraisopropoxide, zirconium tetra-n-butoxide, and zirconium tetra-t-butoxide are preferred.

  Specific examples of the germanium compound include inorganic germanium compounds such as germanium oxide and germanium chloride, and organic germanium compounds such as tetraalkoxygermanium. In view of price and availability, germanium oxide, tetraethoxygermanium, tetrabutoxygermanium, and the like are preferable, and germanium oxide is particularly preferable.

  The amount of the catalyst used in the case of using a metal compound as these polymerization catalysts, the lower limit is usually 5 ppm or more, preferably 10 ppm or more, and the upper limit is usually 30000 ppm or less, preferably 1000 ppm or less, as the amount of metal relative to the produced polyester. More preferably, it is 250 ppm or less, Especially preferably, it is 130 ppm or less. If too much catalyst is used, it is not only economically disadvantageous but also lowers the thermal stability of the polymer. Conversely, if it is too little, the polymerization activity is lowered, and as a result, the polymer decomposes during polymer production. Is more likely to be triggered. The amount of catalyst used here is a preferred embodiment because the amount of terminal carboxyl groups of the polyester produced is reduced as the amount used is reduced.

  The reaction temperature of the esterification reaction and / or transesterification reaction between the dicarboxylic acid component and the diol component is usually in the range of 150 to 260 ° C., and the reaction atmosphere is usually an inert gas atmosphere such as nitrogen or argon. . Further, the reaction pressure is usually normal pressure to 10 kPa. The reaction time is usually about 1 hour to 10 hours.

  In the production process described above, a chain extender (coupling agent) may be added to the reaction system. After the completion of polycondensation, the chain extender is added to the reaction system without solvent in a uniform molten state and reacted with the polyester obtained by polycondensation.

  High molecular weight polyesters using these chain extenders (coupling agents) can be produced using known techniques. After the completion of polycondensation, the chain extender is added to the reaction system without solvent in a uniform molten state and reacted with the polyester obtained by polycondensation. Specifically, a polyester obtained by catalyzing a diol and a dicarboxylic acid and having a terminal group substantially having a hydroxyl group and a weight average molecular weight (Mw) of 20,000 or more, preferably 40,000 or more. By reacting the chain extender with the prepolymer, a polyester resin having a higher molecular weight can be obtained. If the prepolymer has a mass average molecular weight of 20,000 or more, the use of a small amount of a coupling agent does not affect the remaining catalyst even under severe conditions such as a molten state, so that no gel is formed during the reaction. High molecular weight polyester can be produced.

  The obtained polyester may be solidified after solidification as necessary in order to further increase the degree of polymerization and to remove oligomers such as cyclic trimers. Specifically, after the polyester is made into chips and dried, the polyester is pre-crystallized by heating at a temperature of 100 to 180 ° C. for about 1 to 8 hours, and then inactive at a temperature of 190 to 230 ° C. It is carried out by heating for 1 to several tens of hours under gas flow or under reduced pressure.

  The intrinsic viscosity (measured at 35 ° C. with an orthochlorophenol solution) of the polyester obtained as described above is preferably 0.5 dl / g to 1.5 dl / g, more preferably 0.6 dl / g. g to 1.2 dl / g. When the intrinsic viscosity is less than 0.5 dl / g, mechanical properties required for a polyester film as a transflective film substrate, such as tear strength, may be insufficient. On the other hand, when the intrinsic viscosity exceeds 1.5 dl / g, productivity in the raw material manufacturing process and the film forming process is impaired.

  Various additives may be added to the manufactured polyester or within the range in which the properties are not impaired, for example, plasticizers, UV stabilizers, anti-coloring agents, and matting agents. Deodorizers, flame retardants, weathering agents, antistatic agents, yarn friction reducing agents, mold release agents, antioxidants, ion exchange agents, color pigments, and the like can be added. These additives are added in the range of 5 to 50% by mass with respect to the entire polyester resin composition.

It is preferable that the resin composition containing the polyester obtained as described above contains 10 to 19% of the biomass-derived carbon content based on the measurement of radioactive carbon (C14) with respect to the total carbon in the polyester. Since carbon dioxide in the atmosphere contains C14 at a constant ratio (105.5 pMC), the C14 content in plants that grow by incorporating carbon dioxide in the atmosphere, for example, corn, is also about 105.5 pMC. It is known. It is also known that fossil fuel contains almost no C14. Therefore, the proportion of carbon derived from biomass can be calculated by measuring the proportion of C14 contained in all the carbon atoms in the polyester. In the present invention, in the case where the content of C14 in the polyester and P _C14, the content of P _{bio Bio} carbon from biomass, are defined as follows.
P _bio (%) = P _C14 /105.5×100

Taking polyethylene terephthalate as an example, polyethylene terephthalate is a polymer obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1: 1. Is used, the content P _bio of carbon derived from biomass in the polyester is 20%. In this invention, it is preferable that content of carbon derived from biomass by radioactive carbon (C14) measurement is 10 to 19% with respect to the total carbon in the resin composition. When the carbon content derived from biomass in the resin composition is less than 10%, the effect as a carbon offset material becomes poor. On the other hand, as described above, the biomass-derived carbon content in the resin composition is preferably closer to 20%. However, from the viewpoint of problems in the production process of the film and the physical properties, the additive as described above is included in the resin. Since it is preferable to include it, the actual upper limit is 19%.

<Resin film>
The resin film according to the present invention is composed of the above-described resin composition. In order to process the resin composition into a film, a conventional method of forming a film from a polyester resin can be employed. Specifically, after drying the resin composition described above, the resin composition is supplied to a melt extruder heated to a temperature equal to or higher than the melting point of the polyester (Tm) to Tm + 70 ° C. to melt the resin composition, for example, A film can be formed by extruding into a sheet form from a die such as a T die, and rapidly solidifying the extruded sheet with a rotating cooling drum or the like. As the melt extruder, a single screw extruder, a twin screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

  The resin film according to the present invention is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to obtain a longitudinally stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The longitudinal stretching is usually performed in a temperature range of 50 to 100 ° C. Further, the ratio of the longitudinal stretching is preferably 2.5 times or more and 4.2 times or less, although it depends on the required characteristics of the film application. When the draw ratio is less than 2.5, the thickness unevenness of the polyester film becomes large and it is difficult to obtain a good film.

  The longitudinally stretched film is successively subjected to the transverse stretching, heat setting, and thermal relaxation treatment steps to form a biaxially stretched film. The transverse stretching is usually performed in a temperature range of 50 to 100 ° C. The transverse stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the required characteristics of this application. If it is less than 2.5 times, the thickness unevenness of the film becomes large and it is difficult to obtain a good film, and if it exceeds 5.0 times, breakage tends to occur during film formation.

  A heat setting treatment is subsequently performed after the transverse stretching, and a preferable temperature range for heat setting is Tg + 70 to Tm-10 ° C. of polyester. The heat setting time is preferably 1 to 60 seconds. Furthermore, for applications that require a low thermal shrinkage rate, heat relaxation treatment may be performed as necessary.

In the resin film obtained as described above, the thickness of the stretched film is arbitrary depending on the application, but is usually about 5 to 500 μm. Breaking strength of such a resin film is 5 to 35 kg / mm ² at 5~40kg / ^mm 2, TD direction MD direction, elongation at break from 50 to 350% in MD direction, the TD direction 50-300%. Further, the shrinkage rate when left in a temperature environment of 150 ° C. for 30 minutes is 0.1 to 5%. Thus, the film which consists of a resin composition by this invention is equivalent to the physical property of the polyester film manufactured only from the material derived from the conventional fossil fuel.

  The formed biaxially stretched film has chemical functions, electrical functions, magnetic functions, mechanical functions, friction / abrasion / lubrication functions, optical functions, thermal functions, surface functions such as biocompatibility, etc. For the purpose of application, it is also possible to perform secondary processing. Examples of secondary processing include embossing, painting, adhesion, printing, metalizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, Coating, etc.).

  The resin film by this invention can be used conveniently for uses, such as a packaging product, various label materials, a cover material, a sheet molded product, a laminate tube.

  Hereinafter, although the present invention is explained based on an example, the present invention is not limited to these.

Example 1
<Synthesis of biomass-derived polyester>
83 parts by mass of terephthalic acid and 62 parts by mass of biomass ethylene glycol (manufactured by India Glycol) were supplied as a slurry to the reaction vessel, and the esterification reaction was carried out at 240 ° C. for 5 hours by a conventional direct weight method. Thereafter, 0.013 parts by mass of trimethyl phosphate (manufactured by Aldrich) was added (15 mmol% with respect to the acid component), and then the polymerization reaction was performed under a high-temperature vacuum condition. First, in 40 minutes, the degree of vacuum was raised to 4000 Pa and the polymerization temperature was 280 ° C., and then the degree of vacuum was lowered to 200 Pa while maintaining the polymerization temperature at 280 ° C. to carry out a melt polymerization reaction. The reaction time was 3 hours. The synthesized polymer was discharged into running water in the form of strands and pelletized by a pelletizer. The pellets were dried at 160 ° C. for 5 hours and then subjected to solid phase polymerization at 205 ° C. under a vacuum of 50 Pa in a nitrogen atmosphere to obtain a polymer having an intrinsic viscosity of 0.8 dl / g. The intrinsic viscosity was calculated from the melt viscosity measured at 35 ° C. using a phenol / tetrachloroethane (component ratio: 3/2) solvent. When the obtained polymer was subjected to differential thermal analysis (apparatus: Shimadzu DSC-60, measurement condition: helium gas, heated at 6 ° C./min), the glass transition temperature was 69 ° C., which was derived from fossil fuel. It was equivalent to the known polyethylene terephthalate obtained from the raw material. Moreover, when the carbon-made measurement of the obtained biomass-derived polyethylene terephthalate was performed, the content of biomass-derived carbon as measured by radioactive carbon (C14) was 16%.

<Production of film>
After drying 90 parts by mass of the polyethylene terephthalate pellets obtained as described above and 10 parts by mass of a polyethylene terephthalate masterbatch derived from a fossil fuel containing 200 ppm of porous silica having an average particle size of 0.9 μm as a lubricant, it is fed into an extruder. It was fed, melted at 285 ° C., extruded into a sheet form from a T die, and cooled and solidified with a cooling roll to obtain an unstretched sheet. Next, this unstretched sheet was stretched at a magnification of 3.5 times in the longitudinal direction at a speed of the low speed drive roll of 6.5 m / min and a speed of the high speed drive roll of 22 m / min. A biaxially stretched polyester film 1 having a thickness of 12.02 μm was obtained by stretching in the transverse direction at a magnification of 3.5 times.

Comparative Example 1
60 parts by mass of polyethylene terephthalate (inherent viscosity: 0.83 dl / g) manufactured from raw materials derived from conventional fossil fuels, and recycled PET (re-pelletized loss parts in the manufacturing process such as ear loss during film formation) 30 parts by mass and 10 parts by mass of the polyethylene terephthalate masterbatch used above are dried and then supplied to an extruder, melted at 285 ° C., extruded into a sheet form from a T-die, and cooled and solidified by a cooling roll. A stretched sheet was obtained. Next, this unstretched sheet was stretched at a magnification of 3.5 times in the longitudinal direction at a speed of the low speed drive roll of 6.5 m / min and a speed of the high speed drive roll of 22 m / min. A biaxially stretched polyester film 2 having a thickness of 12.06 μm was obtained by stretching in the transverse direction at a magnification of 3.5 times.

<Radiation carbon measurement>
When the obtained film 1 was subjected to radiation carbon measurement, the content of biomass-derived carbon as measured by radioactive carbon (C14) was 14%. Moreover, when the radiation carbon measurement was similarly performed about the film 2, content of carbon derived from biomass was 0%.

<Evaluation of film>
From each of the obtained film in the MD direction (winding direction) and the TD direction (direction made by an angle of 90 degrees with the MD direction), a test piece was cut into a width of 15 mm and a length of 200 mm, and a tensile tester (Tensilon). Using RTC-125A (Orientec Co., Ltd.), the tensile strength of the test piece was measured in an environment of a temperature of 23 ° C. and a humidity of 50 RH%. In addition, F5 values in MD and TD directions (tensile strength when the film was stretched 5%) were measured. Table 1 shows the tensile strength (kg / mm ² ) and elongation at break (%), and F5 value (kg / mm ² ) in the MD direction and TD direction, respectively.

  Moreover, the test piece cut out from each of MD direction and TD direction was put into a 150 degreeC heating oven, and the heat shrink rate when heat-treating for 30 minutes at 150 degreeC based on JIS / C-2318 was measured. The results were as shown in Table 1.

  In addition, each film obtained above was cut into a width of 50 mm and a length of 50 mm to obtain a test piece. Using this test piece, a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.) was used at 23 ° C. and a humidity of 50 RH%. The haze measurement of the film was performed under the environment. The measurement was performed according to JIS K7136: 2000. The measurement results were as shown in Table 1 below.

  In addition, for each of the film surfaces subjected to corona treatment and those not subjected to the corona treatment, a wet tension test mixed solution (manufactured by Wako Pure Chemical Industries, Ltd.) is used for a test piece cut to a width of 50 mm and a length of 50 mm. Then, the wetting tension was measured in an environment of 23 ° C. and humidity of 50 RH%. The measurement was performed according to JIS K6768: 1999. The measurement results were as shown in Table 1 below.

  Further, the friction coefficient between the test pieces subjected to the corona treatment on the surface obtained above and the friction coefficient between the test pieces not subjected to the corona treatment were measured using a friction coefficient measuring device (AFT-200, Daiei Scientific Instruments Co., Ltd.). The measurement was performed in an environment of 23 ° C. and humidity of 50 RH%. The measurement was performed according to JIS K7125: 1999. The measurement results were as shown in Table 1 below.

  As is clear from Table 1, it can be seen that the polyethylene terephthalate film synthesized using biomass-derived ethylene glycol has physical properties comparable to those of existing polyester films.

Claims (8)

A resin composition comprising, as a main component, a polyester comprising a diol unit and a dicarboxylic acid unit,
Resin composition comprising 50 to 95% by mass of polyester having a diol unit of biomass-derived ethylene glycol and a dicarboxylic acid unit of fossil fuel-derived dicarboxylic acid based on the whole resin composition object.   The resin composition according to claim 1, wherein the fossil fuel-derived dicarboxylic acid is terephthalic acid.   The resin composition according to claim 1 or 2, further comprising an additive.   The resin composition according to claim 3, comprising 5 to 50% by mass of the additive with respect to the entire resin composition.   The additives include plasticizers, UV stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, yarn friction reducing agents, mold release agents, antioxidants, and ion exchange. The resin composition according to claim 3 or 4, which is one or more selected from the group consisting of an agent and a color pigment.   Resin composition as described in any one of Claims 1-5 whose content of carbon derived from biomass by radioactive carbon (C14) measurement is 10 to 19% with respect to the total carbon in the said resin composition. object.   The resin film which consists of a resin composition as described in any one of Claims 1-6.   The resin film according to claim 7, which is biaxially stretched.