WO2024128150A1 - 延伸フィルム成形用樹脂組成物 - Google Patents

延伸フィルム成形用樹脂組成物 Download PDF

Info

Publication number
WO2024128150A1
WO2024128150A1 PCT/JP2023/043982 JP2023043982W WO2024128150A1 WO 2024128150 A1 WO2024128150 A1 WO 2024128150A1 JP 2023043982 W JP2023043982 W JP 2023043982W WO 2024128150 A1 WO2024128150 A1 WO 2024128150A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
resin
poly
hydroxybutyrate
stretched
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/043982
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
直也 上仮屋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kaneka Corp
Original Assignee
Kaneka Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kaneka Corp filed Critical Kaneka Corp
Priority to EP23903437.4A priority Critical patent/EP4636035A1/en
Priority to JP2024564347A priority patent/JPWO2024128150A1/ja
Publication of WO2024128150A1 publication Critical patent/WO2024128150A1/ja
Priority to US19/235,769 priority patent/US20250304785A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • B29C55/14—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively
    • B29C55/143—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively firstly parallel to the direction of feed and then transversely thereto
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/04—Oxygen-containing compounds
    • C08K5/05—Alcohols; Metal alcoholates
    • C08K5/053—Polyhydroxylic alcohols
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/04—Oxygen-containing compounds
    • C08K5/14—Peroxides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/20—Carboxylic acid amides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2467/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2467/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2203/00—Applications
    • C08L2203/16—Applications used for films
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
    • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2312/00—Crosslinking

Definitions

  • the present invention relates to a resin composition for forming stretched films that contains a poly(3-hydroxyalkanoate) resin.
  • microplastics which are plastics that break down and break down into tiny particles due to ultraviolet rays, adsorb harmful compounds in seawater, and are then ingested by marine organisms, resulting in the incorporation of harmful substances into the food chain.
  • biodegradable plastics are expected to combat this type of marine pollution, but a report compiled by the United Nations Environment Programme in 2015 pointed out that plastics that can be biodegraded through compost, such as polylactic acid, cannot be expected to decompose in a short period of time in the cold ocean temperatures, and therefore cannot be used to combat marine pollution.
  • poly(3-hydroxyalkanoate) resins are attracting attention as a material that can solve the above problems because they are capable of biodegrading even in seawater.
  • a method of stretching a film is known as a technique for producing a thin, high-strength film.
  • a method of stretching a film is known as a technique for producing a thin, high-strength film.
  • the molten resin is cooled and solidified using a cast roll to form a roll of raw material, which is then preheated to a temperature at which it can be stretched and then stretched, allowing the stretched film to be produced continuously and with good productivity.
  • poly(3-hydroxyalkanoate) resins are known to be difficult to stretch.
  • Patent Document 1 describes a method for producing a stretched film by melting a thermoplastic resin whose main component is poly(3-hydroxybutyrate) resin, forming it into a film, crystallizing it over a certain period of time, sandwiching it between two rolls and rolling it through rolls to perform a primary stretching, and then performing a secondary stretching at a temperature higher than the temperature during the rolling.
  • Patent Document 1 makes it possible to produce a stretched film whose main component is a poly(3-hydroxybutyrate)-based resin, and achieves a high stretch ratio, but it is essential to carry out an annealing step to crystallize the poly(3-hydroxybutyrate)-based resin before stretching. It is described that this annealing step takes a long time, such as 12 hours, and the film cannot be produced in a continuous process, resulting in poor productivity.
  • Patent Document 1 requires a two-stage stretching process, a first stretching step by roll rolling and a second stretching step at a high temperature, in order to achieve a high stretch ratio, which makes the production process complicated.
  • the inventors' investigations revealed that when continuously producing stretched films containing poly(3-hydroxyalkanoate) resins, the temperature conditions that can be applied during stretching tend to be limited, and the range of temperature conditions available for selection is extremely narrow. When performing stretching industrially, it is desirable to have a wide range of temperature conditions available for selection during stretching.
  • the present invention aims to provide a resin composition for forming stretched films that can be produced with good productivity in a continuous process to produce stretched films containing poly(3-hydroxyalkanoate)-based resins, can achieve high stretch ratios, and can expand the range of temperature conditions that can be selected during stretching.
  • stretched films that contains a poly(3-hydroxyalkanoate) resin in which the ratio of melt viscosity to drawdown time is controlled in a specific relationship, stretched films can be produced in a continuous process with good productivity, a high stretch ratio can be achieved, and the temperature conditions that can be applied during stretching can be expanded, leading to the completion of the present invention.
  • the present invention includes a poly(3-hydroxyalkanoate)-based resin
  • the present invention relates to a resin composition for use in molding a stretched film, in which the ratio of melt viscosity (Pa ⁇ s) measured at 170°C and a shear rate of 122 sec- 1 to the drawdown time (sec) described below is 3.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or more and 8.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less.
  • the present invention provides a resin composition for stretched films that can be produced with good productivity using a continuous process to produce stretched films containing poly(3-hydroxyalkanoate) resins, that can achieve high stretch ratios, and that can expand the range of temperature conditions that can be selected during stretching.
  • a uniaxially stretched film stretched in at least one direction e.g., MD direction
  • a biaxially stretched film stretched in two different directions e.g., MD direction and TD direction
  • FIGS. 1A and 1B are schematic diagrams illustrating an example of a production line according to one embodiment of the present invention, which includes processes from extrusion of a resin composition to film formation and film stretching, followed by winding up of the film.
  • the resin composition disclosed herein is a resin composition for forming stretched films that contains a poly(3-hydroxyalkanoate) resin.
  • the poly(3-hydroxyalkanoate)-based resin (hereinafter sometimes referred to as "P3HA-based resin”) is a biodegradable aliphatic polyester (a polyester not containing an aromatic ring), and is a polyhydroxyalkanoate containing 3-hydroxyalkanoic acid repeating units represented by the general formula: [-CHR-CH 2 -CO-O-] (wherein R is an alkyl group represented by C n H 2n+1 , and n is an integer of 1 to 15).
  • R is an alkyl group represented by C n H 2n+1
  • n is an integer of 1 to 15.
  • those containing 50 mol % or more of said repeating units relative to the total monomer repeating units (100 mol %) are preferred, and more preferably 70 mol % or more.
  • poly(3-hydroxyalkanoate) resins are particularly preferred because they are easy to obtain and process.
  • the poly(3-hydroxybutyrate)-based resin (hereinafter sometimes referred to as "P3HB-based resin") is an aliphatic polyester resin that can be produced from a microorganism, and is a polyester resin that has 3-hydroxybutyrate as a repeating unit.
  • the poly(3-hydroxybutyrate)-based resin may be a poly(3-hydroxybutyrate) that has only 3-hydroxybutyrate as a repeating unit, or it may be a copolymer of 3-hydroxybutyrate and another hydroxyalkanoate.
  • the poly(3-hydroxybutyrate)-based resin may also be a mixture of a homopolymer and one or more types of copolymers, or a mixture of two or more types of copolymers.
  • poly(3-hydroxybutyrate)-based resin examples include poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter sometimes referred to as "P3HB3HH"), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (hereinafter sometimes referred to as "P3HB3HV”), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate), etc.
  • P3HB3HH poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)
  • P3HB3HV poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
  • poly(3-hydroxybutyrate-co-4-hydroxybutyrate) poly(3-hydroxybutyrate-co-3-hydroxyoctanoate)
  • poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) are preferred because they are easy to produce industrially.
  • composition ratio of the repeating units it is possible to change the melting point and degree of crystallinity, and thus physical properties such as Young's modulus and heat resistance, making it possible to impart physical properties between those of polypropylene and polyethylene.
  • poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is preferred.
  • poly(3-hydroxybutyrate)-based resins which have the property of being easily thermally decomposed when heated to 180°C or higher
  • poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is preferred from the viewpoints that it can lower the melting point and enable molding processing at low temperatures.
  • poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) products include Kaneka Biodegradable Polymer Green Planet (registered trademark) from Kaneka Corporation.
  • the melting point and Young's modulus of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) vary depending on the ratio of the 3-hydroxybutyrate and 3-hydroxyvalerate components, but because the two components co-crystallize, the degree of crystallinity is high at 50% or more, and although it is more flexible than poly(3-hydroxybutyrate), the improvement in brittleness is insufficient.
  • the average content ratio of each monomer unit in all monomer units constituting the poly(3-hydroxybutyrate)-based resin can be determined by a method known to those skilled in the art, for example, the method described in paragraph [0047] of WO 2013/147139.
  • the average content ratio means the molar ratio of each monomer unit in all monomer units constituting the poly(3-hydroxybutyrate)-based resin, and when the poly(3-hydroxybutyrate)-based resin is a mixture of two or more poly(3-hydroxybutyrate)-based resins, it means the molar ratio of each monomer unit contained in the entire mixture.
  • the poly(3-hydroxybutyrate) resin may be a mixture of at least two poly(3-hydroxybutyrate) resins differing in the type of constituent monomer and/or the content ratio of the constituent monomer.
  • at least one highly crystalline poly(3-hydroxybutyrate) resin and at least one lowly crystalline poly(3-hydroxybutyrate) resin may be used in combination.
  • highly crystalline poly(3-hydroxybutyrate) resins have excellent productivity but poor mechanical strength, while low-crystalline poly(3-hydroxybutyrate) resins have poor productivity but excellent mechanical properties. It is presumed that when both resins are used in combination, the highly crystalline poly(3-hydroxybutyrate) resin forms fine resin crystal particles, while the low-crystalline poly(3-hydroxybutyrate) resin forms tie molecules that crosslink the resin crystal particles. By using these resins in combination, the strength and productivity of the stretched film can be improved.
  • the content ratio of 3-hydroxybutyrate units contained in the highly crystalline poly(3-hydroxybutyrate) resin is preferably higher than the average content ratio of 3-hydroxybutyrate units in all monomer units constituting the mixture of poly(3-hydroxybutyrate) resins.
  • the content of the other hydroxyalkanoate units in the highly crystalline resin is preferably 1 to 5 mol%, and more preferably 2 to 4 mol%.
  • the highly crystalline poly(3-hydroxybutyrate) resin is preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate), more preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate).
  • the content of 3-hydroxybutyrate units in the low-crystalline poly(3-hydroxybutyrate) resin is preferably lower than the average content of 3-hydroxybutyrate units in all monomer units constituting the mixture of poly(3-hydroxybutyrate) resins.
  • the content of other hydroxyalkanoate units in the low-crystalline resin is preferably 24 to 99 mol%, more preferably 24 to 50 mol%, even more preferably 24 to 35 mol%, and particularly preferably 24 to 30 mol%.
  • the low-crystalline poly(3-hydroxybutyrate) resin is preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate), more preferably poly(3-hydroxybutyrate-co-3-hydroxyhexanoate).
  • the proportion of each resin relative to the total amount of both resins is not particularly limited, but it is preferable that the former be 10% by weight to 60% by weight and the latter be 40% by weight to 90% by weight, and it is even more preferable that the former be 25% by weight to 45% by weight and the latter be 55% by weight to 75% by weight.
  • a medium crystalline poly(3-hydroxybutyrate)-based resin in addition to the highly crystalline poly(3-hydroxybutyrate)-based resin and the low crystalline poly(3-hydroxybutyrate)-based resin, can be used in combination.
  • the content of other hydroxyalkanoate units in the medium-crystalline resin is preferably 6 mol% or more and less than 24 mol%, more preferably 6 mol% or more and 22 mol% or less, even more preferably 6 mol% or more and 20 mol% or less, and preferably 6 mol% or more and 18 mol% or less.
  • poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) being more preferred.
  • the ratio of the medium-crystalline poly(3-hydroxybutyrate) resin to the total of the high-crystalline poly(3-hydroxybutyrate) resin, the low-crystalline poly(3-hydroxybutyrate) resin, and the medium-crystalline poly(3-hydroxybutyrate) resin is preferably 1% by weight or more and 99% by weight or less, more preferably 5% by weight or more and 90% by weight or less, and even more preferably 8% by weight or more and 85% by weight or less.
  • the method for obtaining a blend of two or more poly(3-hydroxybutyrate) resins is not particularly limited, and may be a method for obtaining a blend by microbial production or a method for obtaining a blend by chemical synthesis.
  • a blend may be obtained by melt-kneading two or more resins using an extruder, kneader, Banbury mixer, roll, etc., or a blend may be obtained by dissolving two or more resins in a solvent, mixing, and drying.
  • the weight average molecular weight of the entire poly(3-hydroxybutyrate) resin is not particularly limited, but from the viewpoint of achieving both strength and productivity of the stretched film, it is preferably 200,000 to 2,000,000, more preferably 250,000 to 1,500,000, and even more preferably 300,000 to 1,000,000.
  • the weight average molecular weight of each poly(3-hydroxybutyrate) resin constituting the mixture is not particularly limited.
  • the weight average molecular weight of the high crystalline poly(3-hydroxybutyrate) resin is preferably 200,000 to 1,000,000, more preferably 220,000 to 800,000, and even more preferably 250,000 to 600,000, from the viewpoint of achieving both the strength and productivity of the stretched film.
  • the weight average molecular weight of the low crystalline poly(3-hydroxybutyrate) resin is preferably 200,000 to 2,500,000, more preferably 250,000 to 2,300,000, and even more preferably 300,000 to 2,000,000, from the viewpoint of achieving both the strength and productivity of the stretched film. Furthermore, when the aforementioned medium crystalline poly(3-hydroxybutyrate) resin is further used, the weight average molecular weight of the medium crystalline poly(3-hydroxybutyrate) resin is preferably 200,000 to 2,500,000, more preferably 250,000 to 2,300,000, and even more preferably 300,000 to 2,000,000, from the viewpoint of achieving both strength and productivity of the stretched film.
  • the weight-average molecular weight of poly(3-hydroxybutyrate) resins can be measured in terms of polystyrene using gel permeation chromatography (Shimadzu Corporation HPLC GPC system) with a chloroform solution.
  • a column suitable for measuring the weight-average molecular weight should be used as the column for the gel permeation chromatography.
  • the method for producing poly(3-hydroxybutyrate) resins is not particularly limited, and may be a production method by chemical synthesis or a production method using microorganisms. Among these, a production method using microorganisms is preferable. For the production method using microorganisms, known methods can be applied. For example, known examples of bacteria that produce copolymers of 3-hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB.
  • Alcaligenes eutrophus AC32 (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)) or the like, which has been introduced with genes for P3HA synthesis enzymes, and these microorganisms are cultured under appropriate conditions to accumulate P3HB3HH in the cells.
  • genetically modified microorganisms into which various poly(3-hydroxybutyrate) resin synthesis-related genes have been introduced may be used in accordance with the poly(3-hydroxybutyrate) resin to be produced, and the culture conditions, including the type of substrate, may be optimized.
  • the resin composition according to the present disclosure is a resin composition for forming a stretched film, which contains a poly(3-hydroxyalkanoate) resin and has a ratio of melt viscosity (Pa ⁇ s) measured at 170°C and a shear rate of 122 sec -1 to a drawdown time (sec) described below of 3.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or more and 8.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less.
  • the upper limit of the drawdown time/melt viscosity ratio is 8.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less, preferably 6.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less, and particularly preferably 5.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less.
  • the lower limit is 3.0 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or more, and preferably 3.5 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or more.
  • stretched film molding a uniaxially stretched film stretched in one direction (e.g., MD direction) or a biaxially stretched film stretched in two directions (e.g., MD direction and TD direction) can be produced, and further, a high stretch ratio can be achieved in each direction with a wide range of applicable temperature conditions.
  • the poly(3-hydroxyalkanoate) resin contains a poly(3-hydroxyalkanoate) that is uniformly and appropriately crosslinked.
  • the poly(3-hydroxyalkanoate) resin can be obtained, for example, by melt-kneading an uncrosslinked (linear) poly(3-hydroxyalkanoate) resin with an organic peroxide, as described below.
  • the melt viscosity in the drawdown time/melt viscosity ratio of the resin composition according to the present disclosure is an apparent melt viscosity and is defined as follows.
  • Melt viscosity Using a capillary rheometer, a molten resin composition was extruded at a volumetric flow rate (Q) of 0.716 cm 3 /min and a shear rate of 122 sec -1 through an orifice with a radius (d) of 0.05 cm and a capillary length (l) of 1 cm connected to the end of a barrel with a barrel set temperature of 170° C. and a radius (D) of 0.4775 cm, the load (F) was measured, and the apparent melt viscosity ( ⁇ ) was calculated according to the following formula (1):
  • the melt viscosity of the resin composition according to the present disclosure is not particularly limited, but the upper limit is preferably 2000 (Pa ⁇ s) or less, more preferably 1900 (Pa ⁇ s) or less, and particularly preferably 1800 (Pa ⁇ s) or less.
  • the lower limit is preferably 750 (Pa ⁇ s) or more, more preferably 800 (Pa ⁇ s) or more, and particularly preferably 850 (Pa ⁇ s) or more.
  • the melt viscosity is 750 (Pa ⁇ s) or more, the molecular chains are entangled during stretched film formation, making it difficult for the film to break during stretching.
  • melt viscosity 2000 (Pa ⁇ s) or less
  • the resin pressure is suppressed during stretched film formation, and film stretching can be performed stably.
  • the melt viscosity can be preferably controlled within the above range by the amount of organic peroxide added, the molecular weight of the P3HA-based resin, the amount of uncrosslinked P3HA-based resin used, etc.
  • the drawdown time in the drawdown time/melt viscosity ratio of the resin composition according to the present disclosure is defined as follows. Drawdown time: the time required for the molten resin composition discharged from an orifice to fall 20 cm when measuring the melt viscosity.
  • the drawdown time of the resin composition according to the present disclosure is not particularly limited, but the upper limit is preferably 60 (sec) or less, more preferably 50 (sec) or less, and particularly preferably 40 (sec) or less.
  • the lower limit is preferably 25 (sec) or more, more preferably 27 (sec) or more, and particularly preferably 30 (sec) or more.
  • the drawdown time can be preferably controlled within the above range by the amount of organic peroxide added, the molecular weight of the P3HA-based resin, the amount of uncrosslinked P3HA-based resin used, etc.
  • the resin composition disclosed herein has a large range of temperature conditions that can be applied during stretch film formation, and/or a large maximum stretch ratio that can be stretched without breaking.
  • the stretch ratio at which stretching is possible without breaking when a temperature of 100°C or higher is applied during stretching and the temperature is increased in increments of 10 to 20°C is used.
  • the wider the temperature range at which the stretch ratio is 2x or more the wider the process window, and breaks will not occur due to temperature fluctuations that occur during production, allowing for stable production.
  • the resin composition according to the present disclosure is not particularly limited, but can be produced, for example, by a method including at least a step of melt-kneading a poly(3-hydroxyalkanoate) resin and an organic peroxide in an extruder ("melt-kneading step").
  • This method makes it possible to obtain a resin composition in which the drawdown time/melt viscosity ratio is controlled to 3.0 ⁇ 10-2 (sec/[Pa.s]) or more and 8.0 ⁇ 10-2 (sec/[Pa.s]) or less.
  • organic peroxides used in the melt-kneading step include diisobutyl peroxide, cumyl peroxy neodecanoate, di-n-propyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, di-sec-butyl peroxy dicarbonate, t-butyl peroxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy neodecanoate, bis(4-t-butylcyclohexyl) peroxy dicarbonate, bis(2-ethylhexyl) peroxy dicarbonate, t-hexyl peroxy neodecanoate, t-butyl peroxy neodecanoate, t-butyl peroxy neoheptanoate, t-hexyl peroxy pivalate, t-butyl peroxy pivalate, di(3,5,5
  • t-butylperoxy 2-ethylhexyl carbonate t-butylperoxy isopropyl carbonate
  • t-butylperoxy 2-ethylhexanoate t-butylperoxy 2-ethylhexanoate
  • combinations of two or more of these organic peroxides can also be used.
  • Organic peroxides are used in various forms, such as solid and liquid, and may be liquid forms diluted with a diluent or the like.
  • organic peroxides in a form that can be mixed with P3HA-based resins are preferred because they can be dispersed more uniformly in P3HA-based resins, making it easier to suppress localized modification reactions in the resin composition and making it easier to adjust the drawdown time/melt viscosity ratio.
  • a method for obtaining a P3HA-based resin composition using an organic peroxide is disclosed, for example, in US Pat. No. 9,034,989.
  • the patent discloses a technique characterized by using two or more crosslinking agents having two or more radically reactive functional groups (e.g., epoxy groups or carbon-carbon double bonds) together with an organic peroxide to branch a P3HA-based resin.
  • the ratio of the melt viscosity and the drawdown time defined in the present application is presumed to exceed 8.0 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]).
  • the upper limit of the amount of organic peroxide in the melt-kneading step is preferably 0.8 parts by weight or less, more preferably 0.6 parts by weight or less, and particularly preferably 0.35 parts by weight or less, relative to 100 parts by weight of the P3HA resin.
  • the lower limit is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, even more preferably 0.05 parts by weight or more, and particularly preferably 0.1 parts by weight or more.
  • the poly(3-hydroxyalkanoate) resin used in the melt-kneading step may be the same as that described above, but it is preferable to use a poly(3-hydroxyalkanoate) resin that has not been subjected to a crosslinking treatment.
  • the poly(3-hydroxyalkanoate) resin may have a drawdown time/melt viscosity ratio of 1.5 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or more and 2.7 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or less. Note that a poly(3-hydroxyalkanoate) resin having such a drawdown time/melt viscosity ratio or a composition thereof itself has extremely poor stretch film formability.
  • the amount of the poly(3-hydroxyalkanoate) resin used in the melt-kneading process can be set appropriately depending on the content in the resin composition described above.
  • melt-kneading step at least the P3HA resin and the organic peroxide are fed into an extruder and melt-kneaded, but in addition to these two components, other components such as a crystal nucleating agent, lubricant, filler, plasticizer, etc., as described below, may also be fed into the extruder together and melt-kneaded.
  • other components such as a crystal nucleating agent, lubricant, filler, plasticizer, etc., as described below, may also be fed into the extruder together and melt-kneaded.
  • melt-kneading without adding a crosslinking agent having two or more radically reactive functional groups (e.g., epoxy groups or carbon-carbon double bonds).
  • the P3HA resin, the organic peroxide, and other components as necessary may be fed into the extruder separately, or the components may be mixed together and then fed into the extruder. It is particularly preferable to feed the organic peroxide and the P3HA resin into the extruder separately.
  • This feeding method has the advantage that the dispersibility of the organic peroxide is improved, making it less likely for lumps to form in the resulting molded product and making it easier to adjust the drawdown time/melt viscosity ratio.
  • the P3HA resin contained in the resin composition according to the present disclosure may be composed only of a crosslinked P3HA resin, which is a melt-kneaded product of the P3HA resin and an organic peroxide as described above, or may contain both a crosslinked P3HA resin and an uncrosslinked P3HA resin.
  • a crosslinked P3HA resin and an uncrosslinked P3HA resin in combination it becomes easier to control the drawdown time/melt viscosity ratio of the resin composition to 3.0 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or more and 8.0 ⁇ 10 ⁇ 2 (sec/[Pa ⁇ s]) or less.
  • the proportion of the crosslinked P3HA resin in the total of the crosslinked P3HA resin and the uncrosslinked P3HA resin is preferably 50% by weight or more, more preferably 60% by weight or more.
  • the upper limit is not particularly limited, but is preferably 90% by weight or less, more preferably 80% by weight or less.
  • the resin composition or the stretched film may contain additives that can be used together with the poly(3-hydroxyalkanoate) resin, to the extent that the effects of the invention are not impaired.
  • additives include colorants such as pigments and dyes, odor absorbents such as activated carbon and zeolite, fragrances such as vanillin and dextrin, fillers, plasticizers, antioxidants, weather resistance improvers, UV absorbers, crystal nucleating agents, lubricants, release agents, water repellents, antibacterial agents, sliding improvers, and the like. Only one type of additive may be contained, or two or more types may be contained. The content of these additives can be appropriately set by a person skilled in the art depending on the purpose of use.
  • crystal nucleating agent The resin composition or the stretched film may also contain a crystal nucleating agent.
  • crystal nucleating agents include polyhydric alcohols such as pentaerythritol, galactitol, and mannitol; orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, and boron nitride.
  • pentaerythritol is preferred because of its particularly excellent effect of promoting the crystallization of poly(3-hydroxyalkanoate)-based resins.
  • One type of crystal nucleating agent may be used, or two or more types may be used, and the usage ratio can be appropriately adjusted depending on the purpose.
  • the amount of the crystal nucleating agent used is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, and even more preferably 0.7 to 1.5 parts by weight, per 100 parts by weight of the total amount of poly(3-hydroxyalkanoate) resin.
  • the resin composition or the stretched film may also contain a lubricant.
  • lubricants include behenamide, oleamide, erucamide, stearamide, palmitamide, N-stearylbehenamide, N-stearylerucamide, ethylenebisstearamide, ethylenebisoleamide, ethylenebiserucamide, ethylenebislauramide, ethylenebiscapricamide, p-phenylenebisstearamide, and polycondensates of ethylenediamine, stearic acid, and sebacic acid.
  • behenamide or erucamide is preferred because of its particularly excellent lubricant effect on poly(3-hydroxyalkanoate)-based resins.
  • One or more types of lubricants may be used, and the ratio of use may be appropriately adjusted depending on the purpose.
  • the amount of lubricant used is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and even more preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of the total amount of poly(3-hydroxyalkanoate) resin.
  • the resin composition or the stretched film may contain a filler.
  • a filler By including a filler, a stretched film with higher strength can be obtained.
  • the filler may be either an inorganic filler or an organic filler, or both may be used in combination.
  • the inorganic filler is not particularly limited, but examples thereof include silicates, carbonates, sulfates, phosphates, oxides, hydroxides, nitrides, and carbon black. Only one type of inorganic filler may be used, or two or more types may be used in combination.
  • the amount of the filler is not particularly limited, but is preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight, even more preferably 5 to 70 parts by weight, and even more preferably 10 to 60 parts by weight, per 100 parts by weight of the poly(3-hydroxyalkanoate) resin.
  • the resin composition or the stretched film does not have to contain a filler.
  • the resin composition or the stretched film may contain a plasticizer.
  • the plasticizer include glycerin ester compounds, citrate ester compounds, sebacic acid ester compounds, adipate compounds, polyether ester compounds, benzoic acid ester compounds, phthalic acid ester compounds, isosorbide ester compounds, polycaprolactone compounds, and dibasic acid ester compounds.
  • glycerin ester compounds, citrate ester compounds, sebacic acid ester compounds, and dibasic acid ester compounds are preferred because of their particularly excellent plasticizing effect on poly(3-hydroxyalkanoate) resins.
  • the glycerin ester compounds include glycerin diacetomonolaurate.
  • citrate compounds include acetyl tributyl citrate.
  • sebacic acid ester compounds include dibutyl sebacate.
  • dibasic acid ester compounds include benzyl methyl diethylene glycol adipate.
  • the plasticizer may be used alone or in combination of two or more kinds, and the ratio of use can be appropriately adjusted depending on the purpose.
  • the amount of plasticizer used is not particularly limited, but is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and even more preferably 3 to 10 parts by weight, per 100 parts by weight of the total amount of poly(3-hydroxyalkanoate) resin.
  • the resin composition or the stretched film does not have to contain a plasticizer.
  • the melt-kneading in the melt-kneading step can be carried out according to a known or conventional method, and can be carried out, for example, using an extruder (single-screw extruder, twin-screw extruder), a kneader, or the like.
  • the conditions for melt-kneading are not particularly limited and can be set appropriately, but it is preferable to set a resin temperature and residence time at which the organic peroxide can complete the reaction during melt-kneading.
  • the upper limit of the resin temperature measured with a thermometer in the die is preferably 190°C or less, more preferably 180°C or less, and particularly preferably 170°C or less, and the lower limit is preferably 120°C or more, more preferably 125°C or more, and particularly preferably 130°C or more.
  • the upper limit of the residence time in the extruder is preferably 700 seconds or less, more preferably 500 seconds or less, and particularly preferably 300 seconds or less, and the lower limit is preferably 40 seconds or more, more preferably 50 seconds or more, and particularly preferably 60 seconds or more.
  • the resin temperature and residence time are affected by the set temperature of the extruder, the screw rotation speed, and the screw configuration.
  • the resin temperature exceeds 180°C, deterioration of the poly(3-hydroxyalkanoate) resin may be accelerated, so it is preferable to set the barrel zone where the barrel temperature of the extruder is 120°C or more and 160°C or less in less than half of the extruder, so that the residence time at a resin temperature of 180°C is not 60 seconds or more.
  • the die temperature In order to facilitate pelletization of the resin coming out of the die (for example, pelletization by strand cutting, underwater cutting, etc.), it is preferable to set the die temperature to, for example, 120°C or more and 160°C or less to reduce poor cutting due to insufficient solidification and adhesion of pellets to each other.
  • the form of the resin composition according to the present disclosure is not particularly limited, but examples thereof include pellets and powder.
  • the resin composition according to the present disclosure can be suitably used for stretched film molding, and the resin composition can be used to suitably produce a stretched film.
  • the method for producing a stretched film according to this embodiment includes at least the following steps.
  • steps (i), (ii) and (iii-a) a uniaxially stretched film stretched in the MD direction can be obtained.
  • the MD direction is also called the machine direction, flow direction, or longitudinal direction.
  • the TD direction which will be described later, is perpendicular to the MD direction and is also called the vertical direction or width direction.
  • step (iii-a) After the step (iii-a), it is preferable to carry out the following step (iv).
  • step (iv) A step of heating the film obtained in step (iii-a) to a temperature higher than the temperature in step (iii-a) to obtain a film.
  • step (iii-a) A step of stretching the film obtained in step (iii-a) in the TD direction to obtain a film.
  • steps (i), (ii), (iii-a), and (iii-b) it is possible to obtain a biaxially stretched film stretched in both the MD and TD directions.
  • step (iii-b) After the step (iii-b), it is preferable to carry out the following step (iv).
  • step (iv) A step of heating the film obtained in step (iii-b) to a temperature higher than that in step (iii-b) to obtain a film.
  • step (i) the resin composition according to the present disclosure is first melted.
  • the melting method is not particularly limited, but it is preferable to extrude the molten resin composition from a T-die, that is, to perform the extrusion molding method.
  • a film with a uniform thickness can be easily produced.
  • a single screw extruder, a twin screw extruder, etc. can be appropriately used.
  • the conditions for melting the resin composition may be any conditions that melt the poly(3-hydroxyalkanoate) resin, and the temperature of the molten resin composition may be, for example, about 140 to 210°C.
  • the molten resin composition is then extruded onto a casting roll to form a film.
  • the molten resin composition comes into contact with the casting roll and is cooled while moving along the surface of the casting roll. This causes a portion of the poly(3-hydroxyalkanoate) resin to crystallize.
  • This process may be a process of extruding the molten material onto one or more casting rolls, or a process of placing a touch roll opposite the casting roll and sandwiching the molten material extruded onto the casting roll between the touch rolls. Note that this process is not a process of applying pressure to the film to perform roll rolling.
  • an air knife or an air chamber may be used to ensure stable contact of the molten material with the casting roll.
  • the casting roll may be placed in a water tank or an air chamber may be used.
  • the set temperature of the casting roll is preferably 60°C or less to allow the crystallization and solidification to proceed and to enable peeling from the casting roll. It is more preferably 55°C or less, and even more preferably 50°C or less.
  • the lower limit of the set temperature of the casting roll is preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, even more preferably 12°C or higher, and particularly preferably 15°C or higher.
  • the lower limit of the set temperature of the casting roll may be a temperature above the glass transition temperature (Tg) of the poly(3-hydroxyalkanoate) resin + 10°C, or may be a temperature of Tg + 12°C or higher, or may be a temperature of Tg + 14°C or higher.
  • step (ii) the film formed in step (i) is peeled off from the casting roll to obtain a film.
  • the film can be peeled off from the casting roll by conveying the film toward the next stretching step while rotating the casting roll.
  • Step (iii-a) In step (iii-a), the film obtained in step (ii) is stretched in the MD direction to obtain a film. Step (iii-a) is preferably carried out continuously from step (ii) in one production line.
  • stretching the film in the MD direction refers to pulling the film in the MD direction, and is distinguished from stretching by applying pressure in the thickness direction of the film, such as roll rolling, in which the film is sandwiched between two rolls.
  • the stretching in the MD direction is not particularly limited, but can be performed, for example, by using a roll longitudinal stretching machine to differentiate the rotation speeds of the multiple rolls that transport the film.
  • the stretching ratio in the MD direction can be determined by the ratio of the rotation speed of the roll before stretching to the rotation speed of the roll after stretching.
  • the surface temperature of the film in step (iii-a) is preferably 100°C or higher in order to partially melt the crystals of the poly(3-hydroxyalkanoate) resin and make it stretchable. It is preferably 110°C or higher, and more preferably 120°C or higher. At 100°C or higher, at least a portion of the resin crystals in the film melts, allowing the film to be stretched without breaking. Even at 100°C or higher, if there are many residual crystals, stretching unevenness may occur. However, by using the resin composition for stretched film molding according to the present disclosure, stretching at a high stretch ratio over a wide temperature range without stretching unevenness is possible.
  • the upper limit of the surface temperature of the film in step (iii-a) is preferably 150°C or lower, and more preferably 140°C or lower.
  • the means for controlling the film temperature in step (iii-a) is not particularly limited, but examples include a method of directing air current adjusted to a predetermined temperature onto the film, a method of controlling the film temperature by setting a roll to a predetermined temperature, a method of heating the film using auxiliary heating means such as an IR heater to control the film temperature to a predetermined temperature, and a method of passing the film through an oven adjusted to a predetermined temperature. These may be used alone or in combination.
  • the stretching ratio in step (iii-a) is not particularly limited, but is preferably 2 times or more. More preferably, it is 2.5 times or more, and even more preferably, it is 3 times or more. According to this embodiment, such a high stretching ratio can be achieved by using the resin composition for stretched films according to the present disclosure.
  • the upper limit of the stretching ratio is not particularly limited and may be appropriately determined, but may be, for example, 8 times or less.
  • Step (iii-b) In step (iii-b), the stretched film obtained in step (iii-a) is further stretched in the TD direction to obtain a film. Step (iii-b) is preferably carried out continuously from step (iii-a) in one production line.
  • stretching the film in the TD direction means pulling the film in the TD direction, and is distinct from methods that stretch the film by applying pressure in the thickness direction, such as roll rolling, in which the film is sandwiched between two rolls.
  • the stretching in the TD direction is not particularly limited, but can be performed, for example, by using a transverse stretching machine such as a clip-type tenter to clamp both widthwise ends of the film and pull it in the TD direction.
  • the stretching ratio in the TD direction can be determined by the ratio of the width of the film clamped before stretching to the width of the film clamped after stretching.
  • the film surface temperature in step (iii-b) is preferably 60°C or higher and 150°C or lower in order to partially melt the crystals of the poly(3-hydroxyalkanoate) resin and not to promote excessive crystallization. It is more preferably 65°C or higher and 135°C or lower. If it is 60°C or higher, the film can be stretched uniformly without breaking. If it is 150°C or lower, breakage of the film due to melting of the resin can be suppressed.
  • the means for controlling the film temperature in step (iii-b) is not particularly limited, but the methods described above in step (iii-a) can be appropriately adopted. These methods may be used alone or in combination.
  • the stretching ratio in step (iii-b) is not particularly limited, but is preferably 2 times or more. More preferably, it is 3 times or more, and even more preferably, it is 4 times or more. According to this embodiment, such a high stretching ratio can be achieved by using the resin for forming a stretched film according to the present disclosure.
  • the upper limit of the stretching ratio is not particularly limited and may be appropriately determined, but may be, for example, 8 times or less.
  • step (iv) In step (iv), the film obtained in step (iii-a) or the film obtained in step (iii-b) is heated to a temperature higher than the temperature in step (iii-a) or (iii-b) to obtain a film. Step (iv) is preferably carried out continuously from step (iii-a) or (iii-b) in one production line.
  • the crystallinity of the stretched film can be increased, increasing its strength and stabilizing its physical properties.
  • the film temperature in this step is higher than the film temperature in steps (iii-a) or (iii-b), and is preferably 60°C or higher. More preferably, it is 70°C or higher, and even more preferably, it is 80°C or higher.
  • the upper limit is sufficient as long as it is equal to or lower than the melting temperature of the resin, and is preferably 150°C or lower, more preferably 145°C or lower, and even more preferably 140°C or lower.
  • the film temperature in this step is preferably at least 10°C higher than the film temperature in step (iii-a) or (iii-b), more preferably at least 20°C higher, even more preferably at least 30°C higher, even more preferably at least 40°C higher, and particularly preferably at least 50°C higher.
  • the means for controlling the film temperature in step (iv) is not particularly limited, and the methods described above in step (iii-a) can be appropriately adopted. The above-mentioned methods may be used alone or in combination.
  • step (iv) is preferably performed while applying tension to the film in the stretched direction. This makes it possible to avoid thermal shrinkage of the film. That is, when step (iv) is performed after step (iii-a), it is preferably performed while applying tension to the film in the MD direction. When step (iv) is performed after step (iii-b), it is preferably performed while applying tension to the film in both the MD and TD directions. When applying tension in the MD direction, for example, the rotation speeds of the multiple rolls that transport the film may be controlled separately. When applying tension in the TD direction, for example, step (iv) may be performed while clamping both widthwise ends of the film in a transverse stretching machine and pulling it in the TD direction.
  • step (iv) does not substantially stretch the film. "Does not substantially stretch the film” means that no operation intended to stretch the film is performed in step (iv).
  • the method for producing a stretched film according to this embodiment can be carried out in a continuous process from melt extrusion of the resin composition to formation of the stretched film.
  • a continuous process refers to carrying out the stretching process after forming into a film without carrying out the crystallization process that takes a long time as described in Patent Document 1 (specifically, the process of quenching in ice water and then annealing at 40°C for 12 hours).
  • the steps (i) through to the final step it is preferable to carry out the steps (i) through to the final step while continuously transporting the film.
  • This aspect may be carried out while the produced stretched film is wound up on a winding roll.
  • the final step refers to step (iii-a) when steps (iii-a) through (iii-b) are carried out, and to step (iv) when steps (iii-iv) through (iv) are carried out.
  • the transport speed is not particularly limited, but from the viewpoint of film productivity, it is preferable that the transport speed be 5 m/min or more before the start of stretching. Also, from the viewpoint of production stability, it is preferable that the transport speed be 50 m/min or less before the start of stretching.
  • Figure 1 shows an example of a production line in which steps (i) to (iv) are performed while the film is being transported continuously.
  • the right-facing arrow in the figure indicates the film transport direction.
  • the resin composition according to the present disclosure is melted in an extruder 11.
  • the molten resin composition 21 is extruded onto a casting roll 12 from a T-die connected to the tip of the extruder, and formed into a film on the surface of the roll (step (i)).
  • the molten resin composition is cooled while moving along the surface of the casting roll 12. During this process, part of the resin contained in the resin composition crystallizes.
  • the solidified film 22 is peeled off from the casting roll 12 along the film transport path (step (ii)).
  • the film 22 is guided to the stretching rolls 13, 13', which are arranged at the front and rear of the film's transport direction.
  • the rear roll 13' is set to rotate at a faster speed than the front roll 13. This speed difference causes the film 22 to be pulled in the MD direction, and thus stretched in the MD direction (step (iii-a)).
  • the temperature of the roll 13 is set to a predetermined value using a heat medium, thereby controlling the film temperature during MD stretching.
  • the film 22 stretched in the MD direction is introduced into the transverse stretching machine 14, which is a clip-type tenter.
  • the transverse stretching machine 14 which is a clip-type tenter.
  • both ends of the film in the width direction are clamped and the film is stretched in the TD direction by being pulled in the TD direction (step (iii-b).
  • the film temperature during TD stretching is controlled by applying airflow adjusted to a specified temperature to the film inside the transverse stretching machine.
  • the internal temperature inside the transverse stretching machine 14 is raised while both ends of the film in the width direction are clamped. This heats the film and promotes crystallization of the poly(3-hydroxyalkanoate) resin (step (iv)).
  • the film 22 is taken up by the take-up roll 15. This makes it possible to obtain a biaxially stretched film that is stretched in both the MD and TD directions.
  • the film is continuously transported while it is being processed from the extrusion of the resin composition to film forming and film stretching, and then wound up.
  • the thickness of the stretched film produced is not particularly limited and can be set as appropriate by a person skilled in the art, but from the standpoint of the uniform thickness, appearance, strength, light weight, etc. of the film, it is preferably 10 to 200 ⁇ m, more preferably 12 to 150 ⁇ m, and even more preferably 15 to 100 ⁇ m.
  • Other layers may be laminated onto the stretched film.
  • examples of such other layers include a resin layer, an inorganic layer, a metal layer, a metal oxide layer, and a printed layer.
  • These other layers may be laminate layers, coating layers, or vapor deposition layers.
  • the stretched film is thin but strong, making it suitable for use as packaging film, heat sealable film, twist film, etc.
  • [Item 1] Contains a poly(3-hydroxyalkanoate) resin, The ratio of the melt viscosity (Pa ⁇ s) measured at 170°C and a shear rate of 122 sec- 1 to the drawdown time (sec) described below is 3.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or more and 8.0 ⁇ 10-2 (sec/[Pa ⁇ s]) or less.
  • Drawdown time the time required for the resin composition discharged from the orifice to fall 20 cm when measuring the melt viscosity [Item 2] 2.
  • the resin composition for forming a stretched film according to item 1 wherein the melt viscosity is 750 Pa ⁇ s or more and 2000 Pa ⁇ s or less.
  • the resin composition for forming a stretched film according to item 1 or 2 wherein the drawdown time is 25 sec or more and 60 sec or less.
  • the resin containing a poly(3-hydroxyalkanoate)-based resin contains a melt-kneaded product of a poly(3-hydroxyalkanoate)-based resin and an organic peroxide.
  • Item 6 Item 6. A stretched film obtained by molding the resin composition for forming a stretched film according to any one of Items 1 to 5.
  • [Item 7] 6 A method for producing a stretched film, comprising: a film forming step of forming a film using the resin composition for forming a stretched film according to any one of items 1 to 5; and a stretching step of stretching the film in at least one direction.
  • [Item 8] 8 8. The method for producing a stretched film according to item 7, wherein in the stretching step, the film is stretched at a film surface temperature of 100° C.
  • Item 9 Item 9. The method for producing a stretched film according to item 7 or 8, wherein in the stretching step, the film is stretched at a stretch ratio of 2 or more.
  • Item 10 Item 9. The method for producing a stretched film according to item 7 or 8, wherein the stretching step involves stretching in at least two directions different from each other.
  • Item 11 Item 11. The method for producing a stretched film according to item 10, wherein in the stretching step, the film is stretched at a stretch ratio of 2 or more in at least two directions.
  • the P3HA-based resins used were poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH) resins A-1 to A-4 below, where 3HB represents a 3-hydroxybutyrate repeating unit and 3HH represents a 3-hydroxyhexanoate repeating unit.
  • A-1: P3HB3HH (average content ratio 3HB/3HH 97.2/2.8 (mol%/mol%), weight average molecular weight is 660,000 g/mol, glass transition temperature is 6° C.) Produced according to the method described in Example 2 of WO 2019/142845.
  • Crystal nucleating agent D-1 Pentaerythritol (manufactured by Mitsubishi Chemical Corporation, NeuRizer P)
  • a film was prepared using the resin pellets with a T-die, and was continuously stretched in the MD direction with a roll stretching machine at each stretching temperature shown in Table 1, and the stretchable region was evaluated according to the following evaluation criteria.
  • ⁇ Evaluation criteria> When a stretched film was obtained without breaking during stretching and no stretching unevenness (uneven stretching areas such as film thickness) was visually observed in the obtained stretched film, it was judged that stretching was possible, and the maximum stretching ratio that was possible at each stretching temperature was determined, and the stretchable range was indicated by this maximum stretching ratio.
  • Example 1 Poly(3-hydroxyalkanoate) resin A-1 30 parts by weight, A-2 30 parts by weight, A-3 10 parts by weight, B-1 0.105 parts by weight as an organic peroxide, C-1 0.5 parts by weight as a lubricant, D-1 1.0 parts by weight as a crystal nucleating agent were dry blended.
  • the obtained resin material was put into a ⁇ 26mm same-direction twin-screw extruder hopper with the cylinder temperature and die temperature set to 150 ° C., and the crosslinking reaction was allowed to proceed and complete in the extruder, and then 30 parts by weight of poly(3-hydroxyalkanoate) resin A-4 was put in from the extruder side feeder, further melt-kneaded, extruded onto a strand from the die, solidified the strand by passing it through a water tank filled with 45 ° C. hot water, and cut with a pelletizer to obtain resin pellet P-1.
  • the melt viscosity ( ⁇ ), drawdown time (DT), and DT / ⁇ of the obtained resin pellets are shown in Table 1.
  • the cylinder temperature and die temperature of a single screw extruder having a diameter of 65 mm and connected to a T-die having a width of 700 mm were set to 160°C.
  • the resin pellets P-1 were fed into the single screw extruder and extruded into a film shape using a T-die.
  • the formed film was cooled using a cooling roll set at 50°C, then taken up using a take-up roll.
  • the film was then continuously stretched in the machine direction (MD) at different stretching temperatures (film surface temperature; same below) from 120°C, 130°C, and 140°C, and the maximum stretch ratio possible without stretching unevenness or breakage was confirmed in the machine direction (MD).
  • MD machine direction
  • the resin pellets P-1 were put into the single-screw extruder and extruded into a film shape with a T-die.
  • the formed film was cooled with a cooling roll set at 50 ° C., then taken up with a take-up roll, and continuously stretched to 2 times in the MD direction at 140 ° C. with a roll longitudinal stretching machine, and then continuously stretched to 3 times in the transverse (TD) direction at a stretching temperature of 100 ° C. with a clip-type tenter transverse stretching machine.
  • the film after biaxial stretching was cooled to 50 ° C., and the width direction end was slit to obtain a biaxially stretched film with a width of 1200 mm and a thickness of 20 ⁇ m. The above process was carried out continuously.
  • Example 2 Resin pellets P-2 were produced in the same manner as in Example 1, except that 0.053 parts by weight of organic peroxide was blended. The melt viscosity ( ⁇ ), drawdown time (DT), and DT/ ⁇ of the obtained resin pellets are shown in Table 1. In addition, a film was produced in the same manner as in Example 1, and the stretchable region in MD stretching was evaluated. The evaluation results are shown in Table 1.
  • Example 3 Resin pellets P-3 were produced in the same manner as in Example 1, except that 0.026 parts by weight of organic peroxide was added. The melt viscosity ( ⁇ ), drawdown time (DT), and DT/ ⁇ of the obtained resin pellets are shown in Table 1. In addition, a film was produced in the same manner as in Example 1, and the stretchable region in MD stretching was evaluated. The evaluation results are shown in Table 1.
  • Comparative Example 2 Resin pellets P-5 were produced in the same manner as in Example 1, except that 0.011 parts by weight of organic peroxide was added. The melt viscosity ( ⁇ ), drawdown time (DT), and DT/ ⁇ of the obtained resin pellets are shown in Table 1. In addition, a film was produced in the same manner as in Example 1, and the stretchable region in MD stretching was evaluated. The evaluation results are shown in Table 1.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
PCT/JP2023/043982 2022-12-14 2023-12-08 延伸フィルム成形用樹脂組成物 Ceased WO2024128150A1 (ja)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP23903437.4A EP4636035A1 (en) 2022-12-14 2023-12-08 Resin composition for forming stretched film
JP2024564347A JPWO2024128150A1 (https=) 2022-12-14 2023-12-08
US19/235,769 US20250304785A1 (en) 2022-12-14 2025-06-12 Resin composition for stretched film molding

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-199246 2022-12-14
JP2022199246 2022-12-14

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US19/235,769 Continuation US20250304785A1 (en) 2022-12-14 2025-06-12 Resin composition for stretched film molding

Publications (1)

Publication Number Publication Date
WO2024128150A1 true WO2024128150A1 (ja) 2024-06-20

Family

ID=91484919

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/043982 Ceased WO2024128150A1 (ja) 2022-12-14 2023-12-08 延伸フィルム成形用樹脂組成物

Country Status (4)

Country Link
US (1) US20250304785A1 (https=)
EP (1) EP4636035A1 (https=)
JP (1) JPWO2024128150A1 (https=)
WO (1) WO2024128150A1 (https=)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006168159A (ja) 2004-12-15 2006-06-29 Kaneka Corp 生分解性フィルムの製造方法
WO2013147139A1 (ja) 2012-03-30 2013-10-03 株式会社カネカ 生分解性ポリエステル樹脂組成物
US9034989B2 (en) 2008-06-25 2015-05-19 Metabolix, Inc. Branched PHA compositions, methods for their production, and use in applications
WO2019022008A1 (ja) * 2017-07-24 2019-01-31 株式会社カネカ ポリ（３－ヒドロキシアルカノエート）樹脂組成物
WO2019142845A1 (ja) 2018-01-17 2019-07-25 株式会社カネカ 高組成比率の３ｈｈモノマー単位を含む共重合ｐｈａを生産する形質転換微生物およびそれによるｐｈａの製造方法
WO2022044836A1 (ja) * 2020-08-25 2022-03-03 株式会社カネカ 樹脂フィルム、及び、該樹脂フィルムから形成される袋、手袋、結束材
JP2022062759A (ja) * 2020-10-09 2022-04-21 株式会社カネカ 二軸延伸フィルムの製造方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006168159A (ja) 2004-12-15 2006-06-29 Kaneka Corp 生分解性フィルムの製造方法
US9034989B2 (en) 2008-06-25 2015-05-19 Metabolix, Inc. Branched PHA compositions, methods for their production, and use in applications
WO2013147139A1 (ja) 2012-03-30 2013-10-03 株式会社カネカ 生分解性ポリエステル樹脂組成物
WO2019022008A1 (ja) * 2017-07-24 2019-01-31 株式会社カネカ ポリ（３－ヒドロキシアルカノエート）樹脂組成物
WO2019142845A1 (ja) 2018-01-17 2019-07-25 株式会社カネカ 高組成比率の３ｈｈモノマー単位を含む共重合ｐｈａを生産する形質転換微生物およびそれによるｐｈａの製造方法
WO2022044836A1 (ja) * 2020-08-25 2022-03-03 株式会社カネカ 樹脂フィルム、及び、該樹脂フィルムから形成される袋、手袋、結束材
JP2022062759A (ja) * 2020-10-09 2022-04-21 株式会社カネカ 二軸延伸フィルムの製造方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
See also references of EP4636035A1
T. FUKUI, Y. DOI, J. BACTERIOL., vol. 179, 1997, pages 4821 - 4830

Also Published As

Publication number Publication date
EP4636035A1 (en) 2025-10-22
US20250304785A1 (en) 2025-10-02
JPWO2024128150A1 (https=) 2024-06-20

Similar Documents

Publication Publication Date Title
JP7807897B2 (ja) 延伸フィルムの製造方法
JP2025116158A (ja) 二軸延伸フィルムの製造方法
CN115058108A (zh) 可海洋降解的聚羟基烷酸酯组合物、成型体及其制备方法
US20260021641A1 (en) Method for producing stretched film
US20110028622A1 (en) Poly(hydroxyalkanoic acid) blown film
JP7549484B2 (ja) インフレーション成形体
WO2024007494A1 (zh) 一种聚羟基烷酸酯成型体及其制备方法
JP2023146094A (ja) 熱可塑性樹脂フィルムの製造方法
WO2008028344A1 (en) The composition containing polyhydroxyalkanoate copolymer and polylactic acid used for foam
US20260022219A1 (en) Method for producing stretched film
JP2022185793A (ja) 樹脂組成物及び樹脂フィルム
US20250011556A1 (en) Stretched film and method for producing the same
US20250010539A1 (en) Method for producing stretched film
US20260109105A1 (en) Method for producing stretched film
WO2024128150A1 (ja) 延伸フィルム成形用樹脂組成物
JP2025001853A (ja) 延伸フィルム
WO2024262377A1 (ja) フィルム
WO2025013664A1 (ja) 押出フィルム
WO2025070023A1 (ja) 熱可塑性樹脂フィルムの製造方法
WO2025182626A1 (ja) 延伸フィルムの製造方法
JP2025001851A (ja) 延伸フィルム
WO2024262378A1 (ja) 延伸フィルム
EP4624127A1 (en) Method for producing pellets comprising polyhydroxyalkanoate, and pellets produced thereby
WO2024262376A1 (ja) フィルム
JP2025001852A (ja) フィルム

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23903437

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2024564347

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 2023903437

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2023903437

Country of ref document: EP

Effective date: 20250714

WWP Wipo information: published in national office

Ref document number: 2023903437

Country of ref document: EP