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
• • 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
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/203—Solid polymers with solid and/or liquid additives
• • 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
  • C08L2201/00—Properties
  • C08L2201/06—Biodegradable
• • 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

Definitions

• the present invention relates to a molded article containing a poly(3-hydroxyalkanoate)-based resin composition.
• biodegradable plastics from the viewpoint of biodegradability and carbon neutrality, biodegradable plastics produced by microorganisms using plant-derived raw materials as a carbon source, particularly aliphatic polyester-based resins, have been attracting attention.
• poly(3-hydroxyalkanoate)-based resins such as poly(3-hydroxybutyrate) homopolymer resin, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer resin, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resin, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer resin have been attracting attention.
• the poly(3-hydroxyalkanoate) resins and in particular the copolymer poly(3-hydroxyalkanoate) resins, have a problem in that the mechanical properties of the resulting molded articles are poor because of their low tensile strain.
• Patent Document 1 discloses a high molecular weight aliphatic polyester whose constituent units are aliphatic dicarboxylic acids having branched hydrocarbon groups and whose number average molecular weight is in the range of 30,000 to 200,000, although the type of resin is different, and describes how this improves the tearability of sheets and films.
• Patent Document 2 also discloses that the tensile elongation can be improved by blending a plasticizer having a specific structure with a biodegradable 3-hydroxyalkanoate copolymer.
• Patent Document 1 does not disclose any poly(3-hydroxyalkanoate) resin. Furthermore, the composition described in Patent Document 2 requires the use of an additive having a specific structure, which has the drawback of limiting the composition.
• the inventors have found through their research that when attempting to improve the tensile strain of a molded product containing a poly(3-hydroxyalkanoate) resin, the torque during kneading during production can increase, which can result in excessive heat generation and accelerate the thermal decomposition of the resin.
• the present invention aims to provide a molded body containing a poly(3-hydroxyalkanoate) resin that has improved tensile strain and can suppress torque during manufacturing.
• the inventors conducted extensive research to solve the above problems and discovered that by combining a poly(3-hydroxyalkanoate) copolymer (A) having a weight-average molecular weight of 200,000 or more and 1,000,000 or less with a poly(3-hydroxyalkanoate) resin (B) having a weight-average molecular weight greater than that of the copolymer (A) and a specific monomer composition, in a ratio of (A) content of more than 80% by weight, the tensile strain is improved and the torque during manufacturing can be suppressed to a relatively low value, thus completing the present invention.
• the present invention provides a molded article comprising a poly(3-hydroxyalkanoate)-based resin composition
• the resin composition comprises a poly(3-hydroxyalkanoate) copolymer (A) having a weight average molecular weight (herein after, the weight average molecular weight refers to a weight average molecular weight calculated in terms of polystyrene by gel permeation chromatography using a chloroform solvent) of 200,000 or more and 1,000,000 or less;
• the poly(3-hydroxyalkanoate) copolymer (B) has a weight average molecular weight larger than that of the poly(3-hydroxyalkanoate) copolymer (A), the poly(3-hydroxyalkanoate) copolymer (B) is a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of the other hydroxyalkanoate units being 1 to 23 mol %,
• the molded article has a content of the poly(3-hydroxyalkan
• a molded article containing a poly(3-hydroxyalkanoate) resin which has improved tensile strain and can suppress torque during production.
• By improving the tensile strain it is possible to improve the practical mechanical properties of molded articles containing poly(3-hydroxyalkanoate) resins.
• the torque during kneading can be kept at a relatively low value, heat generation due to kneading and thermal decomposition of the poly(3-hydroxyalkanoate) resin can be suppressed.
• the tensile strain can be improved by the composition of the poly(3-hydroxyalkanoate) resin itself, there is no need to add special additives for this purpose.
• the range of temperature conditions that can be applied during the production of molded articles containing poly(3-hydroxyalkanoate) resins is wide, making it possible to perform stable molding processing and produce molded articles that have relatively uniform thickness and weight and also have good appearance. Moreover, the productivity can be improved, making it possible to mass-produce molded articles at high speed.
• the molded article according to the present embodiment is a molded article made of a resin composition containing a poly(3-hydroxyalkanoate)-based resin as an essential resin component, and can be produced by melt-kneading the resin composition under heating and then cooling and solidifying it.
• the resin composition constituting the molded article according to this embodiment contains at least a poly(3-hydroxyalkanoate)-based copolymer (A) having a weight-average molecular weight of 200,000 or more and 1,000,000 or less, and a poly(3-hydroxyalkanoate)-based copolymer (B) having a weight-average molecular weight greater than that of the copolymer (A).
• the poly(3-hydroxyalkanoate) copolymers (A) and (B) are biodegradable aliphatic polyesters (preferably polyesters not containing aromatic rings) and are copolymers having at least one or more types of 3-hydroxyalkanoate units.
• the poly(3-hydroxyalkanoate) copolymer is also referred to as P3HA.
• the 3-hydroxyalkanoate unit is preferably represented by the following general formula (1). [-CHR-CH 2 -CO-O-] (1)
• R represents an alkyl group represented by C p H 2p+1 , and p represents an integer of 1 to 15.
• R include linear or branched alkyl groups such as methyl, ethyl, propyl, methylpropyl, butyl, isobutyl, t-butyl, pentyl, and hexyl.
• p is preferably 1 to 10, and more preferably 1 to 8.
• the poly(3-hydroxyalkanoate) copolymer (A) and/or (B) preferably contains 3-hydroxyalkanoate units (particularly units represented by general formula (1)) in an amount of 50 mol% or more of the total constituent units (monomer units), more preferably 60 mol% or more, and even more preferably 70 mol% or more.
• the poly(3-hydroxyalkanoate) copolymer may contain only two or more types of 3-hydroxyalkanoate units as the constituent units of the polymer, or may contain other units (e.g., 4-hydroxyalkanoate units, etc.) in addition to one or more types of 3-hydroxyalkanoate units.
• the poly(3-hydroxyalkanoate) copolymer (A) and/or (B) is preferably a copolymer containing 3-hydroxybutyrate (hereinafter sometimes referred to as 3HB) units and other hydroxyalkanoate units. It is preferable that the 3-hydroxybutyrate units are all (R)-3-hydroxybutyrate units.
• the other hydroxyalkanoate units may be 3-hydroxyalkanoate units other than 3HB units, or may be hydroxyalkanoate units other than 3-hydroxyalkanoate units (e.g., 4-hydroxyalkanoate units).
• the other hydroxyalkanoate units may include only one type, or may include two or more types.
• poly(3-hydroxyalkanoate) copolymers (A) and/or (B) include, for example, poly(3-hydroxybutyrate-co-3-hydroxypropionate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (abbreviation: P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (abbreviation: P3HB3HH), Examples include poly(3-hydroxybutyrate-co-3-hydroxyheptanoate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), poly(3-hydroxybutyrate-co-3-hydroxynonanoate), poly(3-hydroxybutyrate-co-3-hydroxydecanoate), poly(3-hydroxybutyrate-co-3-hydroxyundecanoate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (abbreviation:
• P3HA can be produced by microorganisms. Such microbially produced P3HA is usually P3HA composed only of D-form (R-form) hydroxyalkanoic acid repeating units. Among microbially produced P3HA, P3HB3HH, P3HB3HV, P3HB3HV3HH, and P3HB4HB are preferred, P3HB3HH, P3HB3HV, and P3HB4HB are more preferred, and P3HB3HH is particularly preferred, in terms of ease of industrial production. P3HA (A) and P3HA (B) may be copolymers having the same monomer species, or may be copolymers having different monomer species.
• the microorganisms that produce P3HA are not particularly limited as long as they have the ability to produce P3HA.
• the first P3HB-producing bacterium was Bacillus megaterium, discovered in 1925, and other natural microorganisms are known, including Cupriavidus necator (formerly classified as Alcaligenes eutrophus, Ralstonia eutropha) and Alcaligenes latus. In these microorganisms, P3HB accumulates within the bacterial cells.
• Microbial cells in which such microorganisms are cultured under appropriate conditions and P3HA has accumulated within the cells are used.
• genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used according to the P3HA to be produced, and culture conditions, including the type of substrate, may be optimized.
• the weight-average molecular weight of the poly(3-hydroxyalkanoate) copolymer (A) is in the range of 200,000 to 1,000,000.
• the weight-average molecular weight of P3HA (A) 200,000 or more, a molded body can be produced by melt-kneading under heating and cooling and solidifying, and the molded body has good tensile strain and practical mechanical properties.
• the weight-average molecular weight of P3HA (A) 1,000,000 or less the processability is further improved and molding becomes easier.
• the weight-average molecular weight of P3HA (A) is preferably 200,000 to 800,000. It may also be 230,000 or more. Furthermore, 250,000 to 700,000 is more preferable, and 300,000 to 600,000 is even more preferable.
• the weight-average molecular weight of P3HA can be determined as the molecular weight converted into polystyrene using gel permeation chromatography (GPC) (Shimadzu Corporation's "High Performance Liquid Chromatograph 20A System"), a polystyrene gel (Showa Denko KK's "K-G 4A” and “K-806M”) as the column, and chloroform as the mobile phase.
• GPC gel permeation chromatography
• a polystyrene gel Showa Denko KK's "K-G 4A” and "K-806M”
• chloroform as the mobile phase.
• a calibration curve is created using polystyrene with weight-average molecular weights of 31,400, 197,000, 668,000, and 1,920,000.
• the column used in the GPC should be a column appropriate for measuring the molecular weight.
• the poly(3-hydroxyalkanoate) copolymer (A) is a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, and the content of the other hydroxyalkanoate units is preferably 1 mol% or more and 23 mol% or less.
• the content is more preferably 1 to 20 mol%, even more preferably 1 to 15 mol%, and particularly preferably 1 to 10 mol%.
• the lower limit of the content may be 2 mol% or more, or 3 mol% or more.
• the monomer composition ratio in P3HA can be measured by gas chromatography or the like, see, for example, the description in International Publication No. 2014/020838.
• the poly(3-hydroxyalkanoate) copolymer (B) has a weight average molecular weight greater than that of the above-mentioned P3HA (A).
• P3HA (B) which has a relatively large weight average molecular weight
• the difference in weight average molecular weight between P3HA(B) and P3HA(A) is preferably 200,000 or more, more preferably 300,000 or more, and even more preferably 400,000 or more.
• the upper limit of the difference in weight average molecular weight is not particularly limited, but is preferably 2,000,000 or less, more preferably 1,000,000 or less, even more preferably 800,000 or less, and particularly preferably 600,000 or less.
• the weight average molecular weight of the poly(3-hydroxyalkanoate) copolymer (B) is preferably 300,000 or more and 3,000,000 or less.
• P3HA (B) having a weight average molecular weight of 300,000 or more the tensile strain of the molded body is more easily improved.
• the weight average molecular weight of P3HA (B) is preferably 400,000 to 2,000,000, more preferably 500,000 to 1,000,000, and even more preferably 600,000 to 900,000.
• the poly(3-hydroxyalkanoate) copolymer (B) is a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, and the content ratio of the other hydroxyalkanoate units is 1 mol% or more and 23 mol% or less.
• the content ratio is more preferably 1 to 20 mol%, even more preferably 1 to 15 mol%, and particularly preferably 1 to 10 mol%.
• the lower limit of the content ratio may be 2 mol% or more, or may be 3 mol% or more.
• the upper limit of the content ratio is preferably 8 mol% or less, since the tensile strain of the molded body can be further increased.
• the content ratio of P3HA (A) and P3HA (B) is preferably such that the ratio of P3HA (A) is more than 80% by weight and 99.9% by weight or less, and the ratio of P3HA (B) is 0.1% by weight or more and less than 20% by weight, relative to the total of both components (100% by weight).
• the ratio of P3HA (A) is 80% by weight or less and the ratio of P3HA (B) is 20% by weight or more, the torque during melt kneading becomes large, so that excessive heat is generated and the thermal decomposition of P3HA (A) and P3HA (B) may proceed. It is more preferable that the ratio of P3HA(A) is 81% by weight or more and 99% by weight or less, and the ratio of P3HA(B) is 1% by weight or more and 19% by weight or less, and it is even more preferable that the ratio of P3HA(A) is 85% by weight or more and 97% by weight or less, and the ratio of P3HA(B) is 3% by weight or more and 15% by weight or less. Furthermore, the ratio of P3HA(A) may be 95% by weight or less, and the ratio of P3HA(B) may be 5% by weight or more.
• the molded article or resin composition according to this embodiment is different from the expanded resin particles disclosed in WO 2019/146555 or WO 2022/054870, and is a non-expanded molded article or resin composition, and preferably is a molded article or resin composition that does not substantially contain air bubbles inside.
• the density shows a relatively large value, and the value is preferably more than 0.3 g/cm 3 , more preferably 0.5 g/cm 3 or more, and even more preferably 0.7 g/cm 3 or more.
• the upper limit is not particularly limited, but may be, for example, 1.6 g/cm 3 or less, or 1.4 g/cm 3 or less.
• the density of the molded body or resin composition can be determined by the method described in JIS K0061 (Method for measuring density and specific gravity of chemical products) or JIS Z8807 (Method for measuring density and specific gravity of solids).
• the molded body or resin composition according to this embodiment may contain, in addition to P3HA (A) and P3HA (B), optionally at least one selected from the group consisting of poly(3-hydroxybutyrate) resin (C), other resins, crystal nucleating agents, and lubricants.
• P3HA P3HA
• P3HA P3HA
• C poly(3-hydroxybutyrate) resin
• the molded article or resin composition according to this embodiment may further contain a poly(3-hydroxybutyrate) resin (C). This promotes crystallization after melt kneading, and can improve productivity when producing a molded article.
• Poly(3-hydroxybutyrate) resin (C) refers to a homopolymer of 3-hydroxybutyrate, or a polymer that contains a small amount of hydroxyalkanoate units other than 3-hydroxybutyrate units in addition to 3-hydroxybutyrate units. Specifically, it is preferable that poly(3-hydroxybutyrate) resin (C) contains 3-hydroxybutyrate units in a proportion of more than 99 mol% and not more than 100 mol% of the total constituent monomers.
• Hydroxyalkanoate units other than 3-hydroxybutyrate units that may be contained in poly(3-hydroxybutyrate) resin (C) are not particularly limited as long as they are copolymerizable with 3-hydroxybutyrate units, but examples include 3-hydroxyalkanoate units other than 3-hydroxybutyrate units and hydroxyalkanoate units other than 3-hydroxyalkanoate units (e.g., 4-hydroxyalkanoate units). In particular, 3-hydroxyhexanoate units are preferred.
• the weight average molecular weight of poly(3-hydroxybutyrate) resin (C) may be set as appropriate, but is preferably within the range of 10,000 to 1,000,000.
• the weight average molecular weight of resin (C) is 10,000 or more, the crystallization promoting effect of using resin (C) tends to be more easily manifested. It is more preferably 100,000 or more, even more preferably 200,000 or more, and particularly preferably 250,000 or more.
• the weight average molecular weight of resin (C) is 1,000,000 or less, there is a tendency that lumps are less likely to occur in the molded product, processability is improved, and molding is easier. It is more preferably 800,000 or less, even more preferably 500,000 or less, and particularly preferably 400,000 or less.
• the amount of poly(3-hydroxybutyrate) resin (C) may be set as appropriate. However, since the use of resin (C) is more likely to exhibit the crystallization-promoting effect and the biodegradability of the resin composition can be further improved, it is preferable that the amount is 0.1 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the total of P3HA (A) and P3HA (B). 0.5 to 40 parts by weight is more preferable, 1 to 30 parts by weight is even more preferable, and 3 to 20 parts by weight is particularly preferable. The upper limit of the amount of resin (C) may be 15 parts by weight or less, or may be 10 parts by weight or less. Poly(3-hydroxybutyrate) resin (C) does not have to be added.
• the molded article or resin composition may contain another resin that does not fall under any of P3HA (A), P3HA (B), and poly(3-hydroxybutyrate) resin (C).
• the other resin is not particularly limited, but it is preferable that the other resin does not significantly reduce the compatibility or moldability when molding the resin composition, or the mechanical properties of the obtained molded article.
• the other resin is preferably a biodegradable resin.
• the other resins include, for example, aliphatic polyesters having a structure in which aliphatic diols and aliphatic dicarboxylic acids are polycondensed, and aliphatic aromatic polyesters having both aliphatic and aromatic compounds as monomers.
• the former include polyethylene succinate, polybutylene succinate (PBS), polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene succinate adipate (PBSA), polyethylene sebacate, polybutylene sebacate, etc.
• the content of the other resin is preferably 250 parts by weight or less, more preferably 100 parts by weight or less, even more preferably 50 parts by weight or less, and particularly preferably 20 parts by weight or less, per 100 parts by weight of the total of P3HA(A) and P3HA(B). It may also be 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less. There is no particular lower limit for the content of the other resin, and it may be 0 parts by weight.
• the crystal nucleating agent is not particularly limited, and any conventionally known agent can be used, for example, inorganic substances such as pentaerythritol, boron nitride, titanium oxide, talc, layered silicates, calcium carbonate, sodium chloride, and metal phosphates; sugar alcohol compounds derived from natural products such as erythritol, galactitol, mannitol, and arabitol; polyvinyl alcohol, chitin, chitosan, polyethylene oxide, aliphatic carboxylic acid amides, aliphatic carboxylic acid salts, aliphatic alcohols, aliphatic carboxylic acid esters, and dimethyl adipate.
• inorganic substances such as pentaerythritol, boron nitride, titanium oxide, talc, layered silicates, calcium carbonate, sodium chloride, and metal phosphates
• sugar alcohol compounds derived from natural products such as erythri
• dicarboxylic acid derivatives such as dibutyl adipate, diisodecyl adipate, dibutyl sebacate, etc.
• cyclic compounds having a functional group C O and a functional group selected from NH, S, and O in the molecule, such as indigo, quinacridone, and quinacridone magenta
• sorbitol derivatives such as bisbenzylidene sorbitol and bis(p-methylbenzylidene) sorbitol
• compounds containing a nitrogen-containing heteroaromatic nucleus such as pyridine, triazine, and imidazole
• phosphate ester compounds bisamides of higher fatty acids, and metal salts of higher fatty acids.
• the content of the crystal nucleating agent is not particularly limited as long as it can promote the crystallization of the resin components, but is preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.5 to 8 parts by weight, per 100 parts by weight of the total of P3HA(A) and P3HA(B).
• the content of the crystal nucleating agent is within the above range, it is possible to obtain the effect of the crystal nucleating agent while suppressing the decrease in viscosity during molding and the physical properties of the molded product.
• the molded body or resin composition may be substantially free of sugar alcohols such as pentaerythritol.
• substantially free of sugar alcohols means that the amount of sugar alcohols is less than 0.05 parts by weight per 100 parts by weight of P3HA(A) and P3HA(B) combined. It may be less than 0.01 parts by weight.
• sugar alcohols are substantially free of sugar alcohols, it is possible to avoid the problem of sugar alcohols bleeding out from the molded body or resin composition and the associated contamination of the manufacturing equipment. According to this embodiment, good productivity can be achieved even without substantially adding sugar alcohols, which are crystal nucleating agents.
• the molded article or resin composition may further contain a lubricant.
• a lubricant By containing a lubricant, the surface smoothness of the obtained molded article can be improved.
• the lubricant is not particularly limited, but it is preferable to contain at least one selected from the group consisting of behenic acid amide, stearic acid amide, erucic acid amide, and oleic acid amide. By containing these lubricants, the obtained molded article can have good lubricity (particularly external lubricity). Among them, it is preferable to contain behenic acid amide and/or erucic acid amide from the viewpoint of improving processability and productivity.
• the lubricant may be behenamide, stearamide, erucamide, oleamide or a combination of two or more of these, or it may be a combination of behenamide, stearamide, erucamide or oleamide with a lubricant other than these (hereinafter referred to as "other lubricants").
• Examples of other lubricants include, but are not limited to, alkylene fatty acid amides such as methylene bisstearic acid amide and ethylene bisstearic acid amide; polyethylene wax, oxidized polyester wax, glycerin monostearate, glycerin monobehenate, glycerin monolaurate, and other glycerin monofatty acid esters; organic acid monoglycerides such as succinic acid saturated fatty acid monoglycerides; sorbitan fatty acid esters such as sorbitan behenate, sorbitan stearate, and sorbitan laurate; polyglycerin fatty acid esters such as diglycerin stearate, diglycerin laurate, tetraglycerin stearate, tetraglycerin laurate, decaglycerin stearate, and decaglycerin laurate; and higher alcohol fatty acid esters such as stearyl stearate.
• the amount of the lubricant (the total amount when multiple lubricants are used) is not particularly limited as long as it can impart lubricity to the molded body, but is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, even more preferably 0.5 to 10 parts by weight, even more preferably 0.5 to 5 parts by weight, and particularly preferably 0.7 to 4 parts by weight, per 100 parts by weight of P3HA(A) and P3HA(B).
• the amount of the lubricant is within the above range, it is possible to obtain the effect of the lubricant while avoiding bleeding out of the lubricant onto the surface of the molded body.
• the molded body or resin composition may contain other components such as plasticizers; inorganic fillers; antioxidants; ultraviolet absorbers; colorants such as dyes and pigments; and antistatic agents, provided that the functionality of the resulting molded body is not impaired.
• the plasticizer is not particularly limited, but examples thereof include modified glycerin compounds such as glycerin diacetomonolaurate, glycerin diacetomonocaprylate, and glycerin diacetomonodecanoate; adipate compounds such as diethylhexyl adipate, dioctyl adipate, and diisononyl adipate; polyether ester compounds such as polyethylene glycol dibenzoate, polyethylene glycol dicaprylate, and polyethylene glycol diisostearate; benzoate compounds; epoxidized soybean oil; epoxidized fatty acid 2-ethylhexyl; and sebacic acid monoesters. These may be used alone or in combination of two or more. Among the above plasticizers, modified glycerin compounds and polyether ester compounds are preferred in terms of ease of availability and high effectiveness. These may be used alone or in combination of two or more.
• the inorganic filler is not particularly limited, but examples include clay, synthetic silicon, carbon black, barium sulfate, mica, glass fiber, whiskers, carbon fiber, calcium carbonate, magnesium carbonate, glass powder, metal powder, kaolin, graphite, molybdenum disulfide, zinc oxide, etc. These may be used alone or in combination of two or more.
• the antioxidant is not particularly limited, but examples thereof include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. These may be used alone or in combination of two or more.
• the ultraviolet absorbing agent is not particularly limited, but examples thereof include benzophenone compounds, benzotriazole compounds, triazine compounds, salicylic acid compounds, cyanoacrylate compounds, nickel complex compounds, etc. These may be used alone or in combination of two or more.
• the colorants such as pigments and dyes are not particularly limited, but examples include inorganic colorants such as titanium oxide, calcium carbonate, chromium oxide, cuprous oxide, calcium silicate, iron oxide, carbon black, graphite, titanium yellow, and cobalt blue; soluble azo pigments such as lake red, lithol red, and brilliant carmine; insoluble azo pigments such as dinitrile orange and fast yellow; phthalocyanine pigments such as monochlorophthalocyanine blue, polychlorophthalocyanine blue, and polybromophthalocyanine green; condensed polycyclic pigments such as indigo blue, perylene red, isoindolinone yellow, and quinacridone red; and dyes such as oracet yellow. These may be used alone or in combination of two or more.
• the antistatic agent is not particularly limited, but examples thereof include low molecular weight antistatic agents such as fatty acid ester compounds, aliphatic ethanolamine compounds, and aliphatic ethanolamide compounds, and polymeric antistatic agents. These may be used alone or in combination of two or more.
• the molded article according to the present embodiment can exhibit improved tensile strain.
• the molded article satisfies the following conditions.
• the tensile strain can be measured under the conditions described in the Examples section using the measuring device described in the Examples section.
• the increase rate of the tensile strain is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more.
• the upper limit is not particularly limited, but may be 100% or less, or may be 60% or less.
• the resin composition according to the present embodiment can be produced by a known method. Specifically, P3HA (A), P3HA (B), any poly(3-hydroxybutyrate) resin (C), and any other optional components are melt-kneaded using an extruder, kneader, Banbury mixer, kneading roll, or the like. When melt-kneading, it is preferable to mix while paying attention to the decrease in molecular weight due to thermal decomposition.
• the resin composition can also be produced by dissolving each component in a soluble solvent and then removing the solvent.
• each component When produced by melt kneading, each component may be fed separately into an extruder, or each component may be mixed in advance and then fed into an extruder.
• melt kneading is performed using an extruder, the resulting resin composition may be extruded into a strand shape and then cut to be processed into particle shapes such as bar shapes, cylinders, elliptical cylinders, spheres, cubes, and rectangular parallelepipeds.
• the resin temperature during melt mixing cannot be generally determined because it depends on the melting point and melt viscosity of the resin used, but from the viewpoint of achieving good dispersibility while avoiding thermal decomposition of P3HA(A) and P3HA(B), it is preferably 140 to 200°C, more preferably 150 to 195°C, and even more preferably 160 to 190°C.
• a molded article can be produced from the resin composition.
• the molding method is not particularly limited as long as it is a molding method including a process of melting and kneading the resin composition under heating and cooling and solidifying it.
• the shear rate during molding cannot be generally defined because it depends on the molding method, the size of the molding machine, the melting point and melt viscosity of the resin used, etc., but from the viewpoint of achieving good dispersibility while avoiding thermal decomposition of P3HA(A) and P3HA(B), it is preferably 10 sec -1 or more, more preferably 30 sec -1 or more, and even more preferably 50 sec -1 or more. There is no particular upper limit, and it may be 10,0000 sec -1 or less, or may be 500 sec -1 or less.
• the resin temperature during molding cannot be generally determined because it depends on the melting point and melt viscosity of the resin used, but from the viewpoint of achieving good dispersibility while avoiding thermal decomposition of P3HA(A) and P3HA(B), a temperature of 140 to 200°C is preferable, 150 to 195°C is more preferable, and 160 to 190°C is even more preferable.
• the molded article according to this embodiment can be suitably used in the fields of agriculture, fishing, forestry, horticulture, medicine, hygiene products, the food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields.
• a molded article comprising a poly(3-hydroxyalkanoate)-based resin composition
• the resin composition comprises a poly(3-hydroxyalkanoate) copolymer (A) having a weight average molecular weight (herein after, the weight average molecular weight refers to a weight average molecular weight calculated in terms of polystyrene by gel permeation chromatography using a chloroform solvent) of 200,000 or more and 1,000,000 or less;
• the poly(3-hydroxyalkanoate) copolymer (B) has a weight average molecular weight larger than that of the poly(3-hydroxyalkanoate) copolymer (A), the poly(3-hydroxyalkanoate) copolymer (B) is a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of the other hydroxyalkanoate units being 1 to 23 mol
• poly(3-hydroxyalkanoate)-based copolymer (A) and/or (B) is at least one selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).
• P3HA(A) As P3HA(A), the following poly(3-hydroxybutyrate-co-3-hydroxyhexanoate): P3HB3HH (Kaneka Corporation, Kaneka biodegradable polymer GreenPlanet (registered trademark)) was used.
• P3HA(B) the following poly(3-hydroxybutyrate-co-3-hydroxyhexanoate): P3HB3HH (Kaneka Corporation, Kaneka biodegradable polymer GreenPlanet (registered trademark)) was used.
• B-4: (3-hydroxybutyrate)/(3-hydroxyhexanoate) 89.5/10.5 (mol%/mol%), powder-like P3HB3HH having a weight average molecular weight Mw of 860,000 as measured by GPC.
• the monomer composition ratio of P3HB3HH was determined as follows. 1 mL of sulfuric acid-methanol mixture (15:85) and 1 mL of chloroform were added to approximately 20 mg of P3HB3HH, the container was sealed, and heated at 100°C for 140 minutes to obtain the methyl ester of the P3HB3HH decomposition product. After cooling, 0.5 mL of deionized water was added and mixed well, and the mixture was left to stand until the aqueous and organic layers separated. The monomer unit composition of the P3HB3HH decomposition product in the separated organic layer was then analyzed by capillary gas chromatography. The ratio of 3-hydroxyhexanoate was calculated from the peak area obtained.
• the weight average molecular weight of P3HB3HH was measured by first dissolving the resin to be measured in chloroform and heating the solution in a hot water bath at 60° C. for 0.5 hours, filtering the soluble matter through a disposable PTFE filter having a pore size of 0.45 ⁇ m, and then using the filtrate to perform GPC measurement under the following conditions to determine the weight average molecular weight value.
• GPC measuring device Shimadzu Corporation high performance liquid chromatograph 20A system Column: Showa Denko K-G 4A (1 column), K-806M (2 columns) Sample concentration: 1 mg/ml Free solution: chloroform solution Free solution flow rate: 1.0 ml/min Sample injection volume: 100 ⁇ L Analysis time: 30 minutes Standard sample: Standard polystyrene
• the press sheet was cut into a JIS K-6251-2 type to prepare a test piece for a tensile test.
• a tensile test was performed on the test piece under the following conditions using an autograph AG-X manufactured by Shimadzu Corporation, and the tensile strain was evaluated.
• Test piece size thickness 1.0 mm, length (between chucks) 50 mm or more, width 20 mm Temperature: 23°C Pulling speed: 2 mm/min Chuck distance: 50 mm Distance between gauge lines: 20mm
• the increase rate (%) relative to the tensile strain obtained in Comparative Example 1 was calculated.
• Example 1 A total of 100 parts by weight of 90% by weight of poly(3-hydroxyalkanoate)-based copolymer (A-1) and 10% by weight of poly(3-hydroxyalkanoate)-based copolymer (B-1) was dry-blended with 0.5 parts by weight of behenamide (BA) and 0.5 parts by weight of erucamide (EA), and then the mixture was melt-kneaded as described above, and the tensile strain was evaluated. The results are shown in Table 1.
• Example 2 The samples were melt-kneaded and evaluated for tensile strain in the same manner as in Example 1, except that the type of poly(3-hydroxyalkanoate) copolymer (B) was changed as shown in Table 1. The results are shown in Table 1.
• Comparative Example 1 the tensile strain of the molded body was a low 7.5%. In Comparative Example 2, the torque during melt kneading was extremely high.

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