JP7276552B2 - polyester resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a biomass polyester resin composition obtained from plant-derived raw materials, and more particularly to a resin composition containing 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, etc., and are inexpensive. Polyester is obtained by polycondensation of diol units and dicarboxylic acid units. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is obtained by esterifying ethylene glycol and terephthalic acid as raw materials. It is produced by a polycondensation reaction after These raw materials are produced from petroleum, which is a fossil resource. For example, ethylene glycol is industrially produced from ethylene, and terephthalic acid is industrially produced from xylene.

In recent years, along with the increasing demand for building a recycling-based society, the use of biomass has been attracting attention in the field of materials as well as the use of fossil fuels, as is the case with energy. Biomass is an organic compound that is photosynthesised from carbon dioxide and water, and is a so-called carbon-neutral renewable energy that is regenerated into carbon dioxide and water by using it. In recent years, the practical use of biomass plastics using these biomass as raw materials has progressed rapidly, and attempts have been made to produce polyesters, which are general-purpose polymer materials, from these biomass raw materials.

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

In addition, biomass ethanol obtained by fermenting starches and sugars obtained from plants such as corn and sugar cane with microorganisms has been put into practical use, and ethylene glycol is industrially produced from this biomass ethanol via ethylene. has also been successful.

Japanese translation of PCT publication No. 2002-512304

The present inventors focused on ethylene glycol, which is a raw material for polyester, and instead of ethylene glycol obtained from conventional fossil fuels, polyester using plant-derived ethylene glycol as its raw material is obtained from conventional fossil fuels. The inventors have found that a polyester produced using ethylene glycol is comparable in physical properties such as mechanical properties. The present invention is based on such findings.

Accordingly, it is an object of the present invention to provide a method for producing a film comprising a resin composition containing a carbon-neutral polyester using biomass ethylene glycol, wherein the film is produced from a conventional raw material obtained from fossil fuels. It is another object of the present invention to provide a method for producing a biaxially stretched resin film which can obtain a film comparable in terms of physical properties such as mechanical properties to those of a biaxially stretched resin film.

A method for producing a biaxially stretched film according to the present invention is a method for producing a biaxially stretched resin film made of a resin composition containing a polyester composed of diol units and dicarboxylic acid units as a main component,
The resin composition is
a biomass-derived polyester in which the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit is fossil fuel-derived terephthalic acid;
Diol derived from fossil fuel or ethylene glycol derived from biomass is used as the diol unit, and terephthalic acid derived from fossil fuel is used as the dicarboxylic acid unit. recycled polyester, and
The manufacturing method is
The biomass-derived polymer having an intrinsic viscosity of 0.5 dl / g to 0.8 dl / g by solid phase polymerization of a polymer obtained by polymerizing the biomass-derived ethylene glycol and the fossil fuel-derived terephthalic acid. a step in which a polyester of
biaxially stretching the resin composition containing the biomass-derived polyester and the recycled polyester,
In the method for producing a biaxially stretched resin film, the step of biaxially stretching is a step of stretching in the longitudinal direction and then stretching in the transverse direction.
In the aspect of the present invention, it is preferable that the resin composition contains the biomass-derived polyester in an amount of 50% by mass or more with respect to the entire resin composition.
In the aspect of the present invention, the resin composition preferably contains the biomass-derived polyester in an amount of 50 to 90% by mass based on the entire resin composition.
In the aspect of the present invention, it is preferable that the resin composition contains 5 to 45% by mass of the recycled polyester with respect to the entire resin composition.
In the aspect of the present invention, the breaking strength of the biaxially stretched resin film is preferably 5-40 kgf/mm ² in the MD direction and 5-35 kgf/mm ² in the TD direction.
In the aspect of the present invention, the elongation at break of the biaxially stretched resin film is preferably 50 to 350% in the MD direction and 50 to 300% in the TD direction.
In an aspect of the present invention, the longitudinal stretching ratio of the biaxially stretched resin film is 2.5 times or more and 4.2 times or less, and the lateral stretching ratio is 2.5 times or more and 5.0 times or less. is preferred.
In the aspect of the present invention, the content of biomass-derived carbon measured by radioactive carbon (C14) in the resin composition is preferably 10 to 19% with respect to the total carbon in the resin composition. .
In an aspect of the present invention, the biaxially stretched resin film preferably has a thickness of 5 to 12.13 μm.

According to the present invention, the resin composition contains polyester in which the diol component unit is biomass-derived ethylene glycol and the dicarboxylic acid component unit is petroleum-derived dicarboxylic acid, and a carbon-neutral film can be produced. . In addition, the film produced by the present invention is comparable in physical properties such as mechanical properties to conventional polyester films produced from raw materials obtained from fossil fuels, and can replace conventional polyester films.

The resin composition according to the present invention contains, as main components, 50 to 90 parts by mass of biomass polyester having biomass-derived ethylene glycol as a diol unit, and 5 to 45% by mass of so-called recycled polyester. A carbon-neutral polyester resin can be realized by using a resin composition containing 50 to 90% by mass of a polyester containing such a biomass-derived diol unit. In addition, since 5 to 45% by mass of recycled polyester is included as a component other than biomass-derived polyester, the film formation stability is improved when forming a film, and a resin composition with low environmental load can be realized. can. In addition, since biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol, polyester using biomass-derived ethylene glycol is different from polyester polymerized from conventional fossil fuel-derived raw materials. Therefore, the film made of the resin composition of the present invention is comparable to conventional polyester films in terms of physical properties such as mechanical properties. The polyester contained in the resin composition will be described below.

<Polyester>
The polyester contained in the resin composition according to the present invention in a proportion of 50 to 90% by mass (hereinafter also referred to as biomass-derived polyester) consists of diol units and dicarboxylic acid units, and biomass-derived ethylene glycol is used as the diol unit. It is obtained by a polycondensation reaction using a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit.

The biomass-derived ethylene glycol used in the biomass-derived polyester is made from ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

A fossil fuel-derived dicarboxylic acid is used as the dicarboxylic acid used in the biomass polyester. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used without limitation. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. Examples of derivatives of aromatic dicarboxylic acids include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters and butyl esters. Ester etc. are mentioned. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the aromatic dicarboxylic acid derivative.

Further, as the aliphatic dicarboxylic acid, specifically, oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, cyclohexanedicarboxylic acid, etc., usually having 2 to 40 carbon atoms. chain or alicyclic dicarboxylic acids. In addition, as derivatives of aliphatic dicarboxylic acids, lower alkyl esters such as methyl esters, ethyl esters, propyl esters and butyl esters of the above aliphatic dicarboxylic acids and cyclic acid anhydrides of the above aliphatic dicarboxylic acids such as succinic anhydride are used. mentioned. Among these, adipic acid, succinic acid, dimer acid, or mixtures thereof are preferred, and those containing succinic acid as a main component are particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

These dicarboxylic acids may 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 copolymerized polyester obtained by adding a copolymerization component as a third component in addition to the above diol component and dicarboxylic acid component. Specific examples of copolymer components include bifunctional oxycarboxylic acids, trifunctional or higher polyhydric alcohols for forming a crosslinked structure, trifunctional or higher polycarboxylic acids and/or their anhydrides, and 3 At least one polyfunctional compound selected from the group consisting of functional or higher oxycarboxylic acids is included. Among these copolymerization components, a bifunctional and/or trifunctional or higher oxycarboxylic acid is particularly preferably used because a copolyester 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 with a high degree of polymerization can be easily produced with a very small amount without using a chain extender to be described later.

The above polyester may also be a high-molecular-weight polyester obtained by chain-extending (coupling) these copolymerized polyesters. A chain extender such as a carbonate compound or a diisocyanate compound can be used as the chain extender. It is usually 10 mol % or less, preferably 5 mol % or less, more preferably 3 mol % or less.

Specific examples of carbonate compounds 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. Carbonate etc. are illustrated. 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 diisocyanate compounds include 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xyloxy Known diisocyanates such as diisocyanate, 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 of polycondensing the above diol units and dicarboxylic acid units. 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 performing a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using

The amount of the diol used in the production of the polyester is substantially equimolar with respect to 100 mol of the dicarboxylic acid or its derivative. is used in an excess of 0.1 to 20 mol %.

Moreover, the polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added at the time of charging the raw materials or at the start of depressurization.

Polymerization catalysts generally include compounds containing Group 1 to Group 14 metal elements in the periodic table, excluding hydrogen and carbon. 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 carboxylates, alkoxy salts, organic sulfonates or β-diketonate salts, inorganic compounds such as oxides and halides of the above metals, and mixtures thereof. Among 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 in a liquid state during polymerization or dissolves in the ester low polymer or polyester because the polymerization rate increases if it is in a molten or dissolved state during polymerization.

As the titanium compound, tetraalkyl titanate is preferable, and specifically, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate, tetraphenyl titanate, tetracyclohexyl titanate, tetra Benzyl titanates and mixed titanates thereof. Also, titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titanium (diisoproxide) acetylacetonate, titanium bis (ammonium lactate) dihydroxide, titanium bis (ethylacetoacetate) diisopropoxide, titanium (triethanolamine) ) isopropoxide, polyhydroxytitanium stearate, titanium lactate, titanium triethanolamine, 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 (eg, product name: C-94 manufactured by Acordis Industrial Fibers), particularly tetra-n-butyl titanate, polyhydroxytitanium stearate. , titanium (oxy)acetylacetonate, titanium tetraacetylacetonate, titania/silica composite oxide (for example, product name: C-94 manufactured by Acordis Industrial Fibers).

Specific examples of zirconium compounds include zirconium tetraacetate, zirconium acetate hydroxide, zirconium tris(butoxy) stearate, zirconyl diacetate, zirconium oxalate, zirconyl oxalate, potassium zirconium oxalate, and polyhydroxyzirconium. Stearate, zirconium ethoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetra-n-butoxide, zirconium tetra-t-butoxide, zirconium tributoxy acetylacetonate and mixtures thereof. Alternatively, zirconium oxide or a composite oxide containing, for example, zirconium and silicon may be used. Among these, zirconyl diacetate, zirconium tris(butoxy)stearate, zirconium tetraacetate, zirconium acetate hydroxide, ammonium zirconium oxalate, potassium zirconium oxalate, polyhydroxyzirconium stearate, zirconium tetra-n-propoxy zirconium tetraisopropoxide, zirconium tetra-n-butoxide and zirconium tetra-t-butoxide are preferred.

Specific examples of germanium compounds include inorganic germanium compounds such as germanium oxide and germanium chloride, and organic germanium compounds such as tetraalkoxygermanium. Germanium oxide, tetraethoxygermanium, tetrabutoxygermanium, and the like are preferred from the viewpoint of price and availability, and germanium oxide is particularly preferred.

In the case of using a metal compound as the polymerization catalyst, the amount of catalyst used is such that 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 with respect to the polyester to be produced. More preferably 250 ppm or less, particularly preferably 130 ppm or less. If the amount of catalyst used is too high, it is not only economically disadvantageous, but also the thermal stability of the polymer is low, whereas if it is too low, the polymerization activity is low, and the resulting degradation of the polymer during the production of the polymer. are more likely to be induced. As for the amount of the catalyst used here, since the amount of terminal carboxyl groups of the polyester produced is reduced as the amount used is reduced, the method of reducing the amount of the catalyst used is a preferred embodiment.

The reaction temperature for 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 atmosphere of an inert gas such as nitrogen or argon. . Further, the reaction pressure is usually normal pressure to 10 kPa. Further, 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 completion of the polycondensation, the chain extender is added to the reaction system in a uniformly molten state without a solvent, and reacted with the polyester obtained by the polycondensation.

High-molecular-weight polyesters using these chain extenders (coupling agents) can be produced using known techniques. After completion of the polycondensation, the chain extender is added to the reaction system in a uniform molten state without a solvent, and reacted with the polyester obtained by the polycondensation. Specifically, a polyester obtained by catalytically reacting a diol and a dicarboxylic acid and having a terminal group substantially having a hydroxyl group and having a weight average molecular weight (Mw) of 20,000 or more, preferably 40,000 or more By reacting the prepolymer with the chain extender, 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, even under severe conditions such as a molten state, even with the use of a small amount of a coupling agent, it is not affected by the residual catalyst, so gel does not occur during the reaction. , can produce high molecular weight polyesters.

After solidifying the obtained polyester, if necessary, solid state polymerization may be carried out in order to further increase the degree of polymerization or to remove oligomers such as cyclic trimers. Specifically, after the polyester is chipped 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 inactivated 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 of the polyester obtained as described above (measured at 35° C. in ortho-chlorophenol solution) is preferably 0.5 dl/g to 1.5 dl/g, more preferably 0.6 dl/g. g~1.2 dl/g. If the intrinsic viscosity is less than 0.5 dl/g, the tear strength and other mechanical properties required for a polyester film as a transflective film substrate may be insufficient. On the other hand, if the intrinsic viscosity exceeds 1.5 dl/g, the productivity in the raw material manufacturing process and the film forming process is impaired.

Various additives may be added in the polyester manufacturing process or to the manufactured polyester as long as the properties are not impaired. , a deodorant, a flame retardant, a weathering agent, an antistatic agent, a yarn friction reducing agent, a releasing agent, an antioxidant, an ion exchange agent, a coloring pigment, and the like can be added. These additives are added in the range of 5 to 20% by mass with respect to the entire polyester resin composition.

The polyester contained in the resin composition according to the present invention at a rate of 5 to 45% by mass (hereinafter also referred to as recycled polyester) consists of a diol unit and a dicarboxylic acid unit, and the diol unit as the diol unit is a fossil fuel-derived diol. Alternatively, it is a polyester obtained by recycling a product made of a polyester resin obtained by a polycondensation reaction using biomass-derived ethylene glycol and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit.

As the resin that is the basis of the recycled polyester (that is, the polyester resin before recycling), even if both the diol unit and the dicarboxylic acid unit are made of raw materials derived from fossil fuels, it is biomass polyester as described above. good too.

Fossil fuel-derived diols used in resins that are the basis of recycled polyesters include aliphatic diols, aromatic diols, and derivatives thereof, and those that are used as diol units in conventional polyesters are preferably used. be able to. The aliphatic diol is not particularly limited as long as it is an aliphatic or alicyclic compound having two OH groups. The following aliphatic diols may be mentioned. Specific examples include ethylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,6-hexamethylene glycol, decamethylene glycol, 1,4-butanediol and 1,4-cyclohexanedimethanol. be done. These may be used alone or as a mixture of two or more. Among these, ethylene glycol, 1,4-butanediol, 1,3-propylene glycol and 1,4-cyclohexanedimethanol are preferred, and ethylene glycol is particularly preferred.

The resin composition containing the polyester obtained as described above preferably contains 10 to 18% of biomass-derived carbon based on radiocarbon (C14) measurement with respect to the total carbon in the polyester. Since carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in the total carbon atoms in the polyester, the ratio of biomass-derived carbon can be calculated. In the present invention, the biomass-derived carbon content P _bio is defined as follows when the content of C14 in the polyester is defined as P _C14 .
P _bio (%) = P _C14 /105.5 x 100

Taking polyethylene terephthalate as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1, so only ethylene glycol derived from biomass is used. is used, the biomass-derived carbon content P _bio in the polyester is 20%. In the present invention, the content of biomass-derived carbon measured by radioactive carbon (C14) is preferably 10 to 19% of the total carbon in the resin composition. If the biomass-derived carbon content in the resin composition is less than 10%, the effect as a carbon offset material is poor. On the other hand, as described above, the biomass-derived carbon content in the resin composition is preferably as close to 20% as possible. Since it is preferable to include additives, the practical upper limit is 18%.

<Resin film>
A resin film according to the present invention comprises the resin composition described above. 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 above resin composition, it is supplied to a melt extruder heated to a temperature (Tm) above the melting point of the polyester to Tm + 70 ° C. to melt the resin composition, for example A film can be formed by extruding a sheet from a die such as a T-die and rapidly cooling and 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 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 carried out using a difference in circumferential speed between two or more rolls. Longitudinal stretching is usually carried out in a temperature range of 50 to 100°C. Further, the longitudinal stretching ratio is preferably 2.5 times or more and 4.2 times or less, although it depends on the properties required for the film application. If the draw ratio is less than 2.5 times, unevenness in the thickness of the polyester film increases, making it difficult to obtain a good film.

The longitudinally stretched film is then successively subjected to transverse stretching, heat setting, and heat relaxation steps to obtain a biaxially stretched film. Lateral stretching is usually carried out in a temperature range of 50 to 100°C. The lateral stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the properties required for the application. If it is less than 2.5 times, the thickness of the film becomes uneven, making it difficult to obtain a good film.

After the transverse stretching, the heat setting treatment is carried out, and the preferable temperature range for the heat setting is from Tg+70 to Tm-10°C of the polyester. Moreover, the heat setting time is preferably 1 to 60 seconds. Furthermore, for applications that require a reduction in heat shrinkage, heat relaxation treatment may be performed as necessary.

The thickness of the stretched resin film obtained as described above is arbitrary according to its use, but is usually about 5 to 500 μm. The breaking strength of such a resin film is 5 to 40 kgf/mm ² in the MD direction and 5 to 35 kgf/mm ² in the TD direction. 50 to 300%. Also, the shrinkage rate when left in a temperature environment of 150° C. for 30 minutes is 0.1 to 5%. Thus, the film made of the resin composition according to the present invention has physical properties equivalent to those of conventional polyester films made only from fossil fuel-derived materials.

The molded biaxially stretched film has chemical functions, electrical functions, magnetic functions, mechanical functions, friction/abrasion/lubricating functions, optical functions, thermal functions, and surface functions such as biocompatibility. It is also possible to apply secondary processing for the purpose of imparting. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.).

INDUSTRIAL APPLICABILITY The resin film according to the present invention can be suitably used for applications such as packaging products, various label materials, lid materials, sheet molded products, laminated tubes, and the like.

Other Aspects The present invention provides a resin composition containing a carbon-neutral polyester using biomass ethylene glycol, wherein the polyester produced from raw materials obtained from conventional fossil fuels and physical properties such as mechanical properties It is another object of the present invention to provide a biomass-derived resin composition from which a polyester having comparable surface properties can be obtained.
A resin composition according to still another aspect of the present invention is a resin composition comprising a polyester comprising a diol unit and a dicarboxylic acid unit,
A polyester whose diol unit is ethylene glycol derived from biomass and whose dicarboxylic acid unit is a dicarboxylic acid derived from fossil fuel is added to 50 to 90% by mass of the total resin composition, and a diol or biomass whose diol unit is derived from fossil fuel 5 to 45% by mass of the resin composition as a whole, 5 to 45% by mass of the polyester obtained by recycling a resin product made of polyester whose dicarboxylic acid unit is ethylene glycol derived from fossil fuel,
It is characterized by comprising:
In yet another aspect of the present invention, it is preferred that the fossil fuel-derived dicarboxylic acid is terephthalic acid.
In yet another aspect of the present invention, it is preferred that the fossil fuel-derived diol is ethylene glycol.
In yet another aspect of the present invention, it is preferred to further contain an additive.
In still another aspect of the present invention, it is preferable that the additive is contained in an amount of 5 to 20% by mass with respect to the entire resin composition.
In still another aspect of the present invention, the additive includes a plasticizer, an ultraviolet stabilizer, an anti-coloring agent, a delustering agent, a deodorant, a flame retardant, a weathering agent, an antistatic agent, and a yarn friction reducing agent. , release agents, antioxidants, ion exchange agents, and color pigments.
In still another aspect of the present invention, the content of biomass-derived carbon measured by radioactive carbon (C14) is preferably 10 to 18% with respect to the total carbon in the polyester.
According to still another aspect of the present invention, there is also provided a resin film made of the above resin composition.
According to still another aspect of the present invention, in the resin composition, a polyester in which the diol component unit is biomass-derived ethylene glycol and the dicarboxylic acid component unit is petroleum-derived dicarboxylic acid is added to the entire resin composition. It is contained in an amount of 50 to 90% by mass, and a carbon-neutral polyester resin can be realized. In addition, the film made of the resin composition of the present invention is comparable in physical properties such as mechanical properties to conventional polyester films produced from raw materials obtained from fossil fuels, and can replace conventional polyester films. .

A method for producing a biaxially stretched resin film according to another aspect of the present invention is a method for producing a biaxially stretched resin film made of a resin composition containing a polyester composed of a diol unit and a dicarboxylic acid unit as a main component. ,
The resin composition is
a biomass-derived polyester in which the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit is fossil fuel-derived terephthalic acid;
Diol derived from fossil fuel or ethylene glycol derived from biomass is used as the diol unit, and terephthalic acid derived from fossil fuel is used as the dicarboxylic acid unit. including recycled polyester,
The manufacturing method is
The biomass-derived polymer having an intrinsic viscosity of 0.5 dl / g to 0.8 dl / g by solid phase polymerization of a polymer obtained by polymerizing the biomass-derived ethylene glycol and the fossil fuel-derived terephthalic acid. a step in which a polyester of
The biomass-derived polyester and a step of biaxially stretching the resin composition containing the recycled polyester are included.
In another aspect of the present invention, the resin composition preferably contains the biomass-derived polyester in an amount of 50% by mass or more relative to the entire resin composition.
In another aspect of the present invention, the resin composition preferably contains the biomass-derived polyester in an amount of 50 to 90% by mass based on the entire resin composition.
In another aspect of the present invention, the resin composition preferably contains 5 to 45 mass % of the recycled polyester with respect to the entire resin composition.
In another aspect of the present invention, the breaking strength of the biaxially stretched resin film is preferably 5-40 kgf/mm ² in the MD direction and 5-35 kgf/mm ² in the TD direction.
In another aspect of the present invention, the elongation at break of the biaxially stretched resin film is preferably 50 to 350% in the MD direction and 50 to 300% in the TD direction.
In another aspect of the present invention, the longitudinal stretching ratio of the biaxially stretched resin film is 2.5 times or more and 4.2 times or less, and the lateral stretching ratio is 2.5 times or more and 5.0 times or less. Preferably.
In another aspect of the present invention, the content of biomass-derived carbon measured by radioactive carbon (C14) in the resin composition is 10 to 19% relative to the total carbon in the resin composition. is preferred.
In another aspect of the present invention, the biaxially stretched resin film preferably has a thickness of 5 to 12.13 μm.

EXAMPLES The present invention will be described below based on Examples, but the present invention is not limited to these.

Example 1
<Synthesis of biomass-derived polyester>
A slurry of 83 parts by mass of terephthalic acid and 62 parts by mass of biomass ethylene glycol (manufactured by India Glycol) was supplied to a reactor, and an esterification reaction was carried out at 240° C. for 5 hours by a conventional direct polymerization method. After that, 0.013 parts by mass of trimethyl phosphate (manufactured by Aldrich) was added (15 mmol % with respect to the acid component), and the polymerization reaction was started under high temperature and vacuum conditions. First, the degree of vacuum was raised to 4000 Pa and the polymerization temperature to 280° C. for 40 minutes, and then the degree of vacuum was lowered to 200 Pa while the polymerization temperature was maintained at 280° C. to carry out 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. After drying the pellets at 160° C. for 5 hours, solid state polymerization was performed at 205° C. under a vacuum of 50 Pa under a nitrogen atmosphere to obtain a polymer with 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. Differential thermal analysis of the obtained polymer (apparatus: Shimadzu Corporation DSC-60, measurement conditions: temperature rise at 6 ° C./min in helium gas) was performed, and the glass transition temperature was 69 ° C., derived from fossil fuels. It was comparable to the known polyethylene terephthalate obtained from the raw material. Further, when the obtained biomass-derived polyethylene terephthalate was subjected to radiocarbon measurement, the biomass-derived carbon content was 16% by radiocarbon (C14) measurement.

<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 fossil fuel-derived polyethylene terephthalate masterbatch containing 200 ppm of porous silica having an average particle size of 0.9 μm as a lubricant, the extruder The mixture was supplied, melted at 285° C., extruded into a sheet from a T-die, and cooled and solidified with a cooling roll to obtain an unstretched sheet. Next, this unstretched sheet is stretched in the longitudinal direction at a magnification of 3.5 times with the speed of the low-speed drive roll set to 6.5 m/min and the speed of the high-speed drive roll set to 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.

Example 2
60 parts by mass of the polyethylene terephthalate obtained in Example 1, 30 parts by mass of recycled PET (a product obtained by repelleting the loss portion in the manufacturing process such as edge loss during film formation), and the polyethylene terephthalate masterbatch used above After drying, 10 parts by mass of the mixture was supplied to an extruder, 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 is stretched in the longitudinal direction at a magnification of 3.5 times with the speed of the low-speed drive roll set to 6.5 m/min and the speed of the high-speed drive roll set to 22 m/min. A biaxially stretched polyester film 2 having a thickness of 12.13 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 (intrinsic viscosity 0.83 dl/g), which is manufactured from conventional fossil fuel-derived raw materials, and recycled PET (repelleted from the loss part in the manufacturing process such as edge loss during film production) 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 from a T-die, cooled and solidified with a cooling roll. A stretched sheet was obtained. Next, this unstretched sheet is stretched in the longitudinal direction at a magnification of 3.5 times with the speed of the low-speed drive roll set to 6.5 m/min and the speed of the high-speed drive roll set to 22 m/min. A biaxially stretched polyester film 3 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 film 1 obtained was subjected to radiocarbon measurement, the biomass-derived carbon content was 14% by radiocarbon (C14) measurement. Similarly, films 2 and 3 were subjected to radiometric carbon measurement, and the content of biomass-derived carbon was 10% and 0%, respectively.

<Evaluation of film>
From each of the MD direction (winding direction) and TD direction (the direction forming an angle of 90 degrees with the MD direction) of each film obtained, a test piece was cut into a width of 15 mm and a length of 200 mm, and a tensile tester (Tensilon RTC-125A, manufactured by Orientec) was used to measure the strength and elongation of the test piece in an environment of temperature 23° C. and humidity 50 RH%. Also, the F5 value (tensile strength when the film is stretched by 5%) in the MD and TD directions was measured. Table 1 shows the tensile strength (kgf/mm ² ) and breaking elongation (%) in the MD and TD directions, and the F5 value (kgf/mm ² ).

Also, test pieces cut out from each of the MD direction and the TD direction were placed in a heating oven at 150° C. and subjected to heat treatment at 150° C. for 30 minutes according to JIS/C-2318 to measure thermal shrinkage. 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. The haze measurement of the film was performed under the environment of The measurement was performed according to JIS K7136:2000. The measurement results were as shown in Table 1 below.

In addition, a mixture solution for wet tension test (manufactured by Wako Pure Chemical Industries, Ltd.) was used for a test piece cut into a width of 50 mm and a length of 50 mm for each film with and without corona treatment on the surface. Then, the wet tension was measured under the environment of 23° C. and 50 RH% humidity. The measurement was performed according to JIS K6768:1999. The measurement results were as shown in Table 1 below.

In addition, the coefficient of friction between the test pieces obtained above with corona treatment on the surface and the coefficient of friction between the test pieces without corona treatment were measured using a friction coefficient measuring instrument (AFT-200, Daiei Kagaku Seiki Seisakusho). (manufacturer) under the 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, the polyethylene terephthalate films synthesized using biomass-derived ethylene glycol (Examples 1 and 2) have physical properties comparable to the existing polyester film (Comparative Example 1). I know you have.

Claims (9)

A method for producing a biaxially stretched resin film comprising a resin composition containing a polyester comprising a diol unit and a dicarboxylic acid unit as a main component,
The resin composition is
a biomass-derived polyester in which the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit is fossil fuel-derived terephthalic acid;
Diol derived from fossil fuel or ethylene glycol derived from biomass is used as the diol unit, and terephthalic acid derived from fossil fuel is used as the dicarboxylic acid unit. recycled polyester, and
The manufacturing method is
The biomass-derived polymer having an intrinsic viscosity of 0.5 dl / g to 0.8 dl / g by solid phase polymerization of a polymer obtained by polymerizing the biomass-derived ethylene glycol and the fossil fuel-derived terephthalic acid. a step in which a polyester of
biaxially stretching the resin composition containing the biomass-derived polyester and the recycled polyester,
The method for producing a biaxially stretched resin film, wherein the step of biaxially stretching is a step of stretching in the longitudinal direction and then stretching in the transverse direction. The method for producing a biaxially stretched resin film according to claim 1, wherein the resin composition contains 50% by mass or more of the biomass-derived polyester with respect to the entire resin composition. 3. The method for producing a biaxially stretched resin film according to claim 1, wherein the resin composition contains 50 to 90% by mass of the biomass-derived polyester with respect to the entire resin composition. The method for producing a biaxially stretched resin film according to any one of claims 1 to 3, wherein the resin composition contains 5 to 45% by mass of the recycled polyester with respect to the entire resin composition. The biaxially stretched resin according to any one of claims 1 to 4, wherein the breaking strength of the biaxially stretched resin film is 5 to 40 kgf/mm ² in the MD direction and 5 to 35 kgf/mm ² in the TD direction. Film production method. The production of the biaxially stretched resin film according to any one of claims 1 to 5, wherein the breaking elongation of the biaxially stretched resin film is 50 to 350% in the MD direction and 50 to 300% in the TD direction. Method. 7. The biaxially stretched resin film according to any one of claims 1 to 6, wherein the longitudinal stretching ratio is 2.5 times or more and 4.2 times or less, and the lateral stretching ratio is 2.5 times or more and 5.0 times or less. The method for producing a biaxially stretched resin film according to any one of items. Any one of claims 1 to 7, wherein the content of biomass-derived carbon measured by radioactive carbon (C14) in the resin composition is 10 to 19% relative to the total carbon in the resin composition. A method for producing a biaxially stretched resin film according to the item. The method for producing a biaxially stretched resin film according to any one of claims 1 to 8, wherein the biaxially stretched resin film has a thickness of 5 to 12.13 µm.