Method of manufacturing laminate

Abstract

To provide a method capable of manufacturing a laminate having good surface quality and containing a poly(3-hydroxyalkanoate)-based resin-containing layer by an extrusion laminate method with good productivity.SOLUTION: An intermediate composition (I) containing a poly(3-hydroxyalkanoate)-based resin is introduced into an extruder provided with a die at its tip, melted inside the extruder, extruded from the die outlet onto the surface of a substrate layer, and then cooled and solidified to form a resin layer, thereby obtaining a laminate. The intermediate composition (I) has, in differential scanning calorimetric analysis, a melting point peak (i) with a peak temperature of 170°C or higher, and a melting point peak (ii) with a peak temperature of 140°C or higher and lower than 170°C. The enthalpy of crystal fusion (ie) calculated for the melting point peak (i) is 0.5 J / g or more, and the ratio of the enthalpy of crystal fusion (ie) to the enthalpy of crystal fusion (iie) calculated for the melting point peak (ii), (ie) / (iie), is 0.5 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a laminate having a resin layer containing a poly(3-hydroxyalkanoate) resin.

Background Art

[0002] In recent years, suppression of marine pollution and transition to a recycling-based society have begun globally, and research and development of bio-derived resins and resins with marine degradability have been actively conducted. As a bio-based and marine-degradable resin, poly(3-hydroxyalkanoate) resins have attracted attention.

[0003] Poly(3-hydroxyalkanoate) resins are thermoplastic polyesters produced and accumulated as energy storage substances in the cells of many microbial species, and are attracting attention because they can be biodegraded not only in soil but also in seawater.

[0004] A laminate formed by laminating a layer containing such a poly(3-hydroxyalkanoate) resin on a biodegradable substrate such as paper is a material in which both the resin and the substrate have excellent biodegradability, and thus is extremely promising from the viewpoint of environmental protection.

[0005] Examples of the method for producing a laminate formed by laminating a resin layer on paper or the like include an extrusion lamination method, a thermal lamination method, and a coating method of an aqueous slurry. Among them, the extrusion lamination method is advantageous from the viewpoints that the mechanical strength of the resin layer can be increased and the adhesive strength between the resin layer and the substrate layer is also excellent.

[0006] The extrusion lamination method is a method of forming a resin layer on a substrate by extruding a heat-melted resin onto the substrate and then forming and cooling and solidifying the resin with a cooling roll. Patent Documents 1 and 2 disclose the production of a laminate including a layer containing a poly(3-hydroxyalkanoate) resin and a substrate layer such as paper by such an extrusion lamination method.

[0007] On the one hand, in Patent Document 3, a method for producing a melt-processing composition containing a poly(3-hydroxybutyrate) resin excellent in solidification properties by heating and extruding a material having specific melting characteristics so that the temperature of the material is within a specific range, and a method for producing a molded article by melt-processing the melt-processing composition are described. However, nothing is mentioned regarding the production of a laminate.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] According to the inventions described in Patent Documents 1 and 2, a laminate formed by laminating a layer containing a poly(3-hydroxyalkanoate) resin on a substrate such as paper can be produced by an extrusion lamination method. However, the productivity of extrusion lamination has not been examined in these documents. In Patent Document 1, the production speed is not described at all, and in Patent Document 2, it is only described that production was carried out at a low speed of 4 m / min in the examples.

[0010] Poly(3-hydroxyalkanoate) resins generally have the property of having a slow solidification rate. Therefore, when trying to increase the production speed in extrusion lamination, the tendency for the resin layer to stick to the cooling roll and become difficult to release becomes stronger. When trying to suppress such a decrease in releasability, the surface properties of the poly(3-hydroxyalkanoate) resin-containing layer may deteriorate.

[0011] In view of the above situation, the object of the present invention is to produce, by the extrusion lamination method, a laminate containing a poly(3-hydroxyalkanoate)-based resin layer having good surface properties with good productivity.

Means for Solving the Problems

[0012] As a result of intensive studies to solve the above problems, the present inventors prepared an intermediate composition containing a poly(3-hydroxyalkanoate)-based resin and exhibiting specific melting characteristics, and by using the intermediate composition to carry out the extrusion lamination method, it was found that a laminate containing a poly(3-hydroxyalkanoate)-based resin layer having good surface properties can be produced with good productivity, and the present invention has been completed.

[0013] That is, the present invention is a method for producing a laminate having a base material layer and a resin layer containing a poly(3-hydroxyalkanoate)-based resin, including a step of charging an intermediate composition (I) containing a poly(3-hydroxyalkanoate)-based resin into an extruder equipped with a die at the tip, melting it in the extruder, extruding it onto the surface of the base material layer from the die outlet, and then cooling and solidifying it to form the resin layer to obtain the laminate, the intermediate composition (I) has a melting point peak (i) with a peak temperature of 170°C or higher and a melting point peak (ii) with a peak temperature of 140°C or higher and lower than 170°C in differential scanning calorimetry, the crystal melting enthalpy (ie) calculated for the melting point peak (i) is 0.5 J / g or more, relates to a method for producing a laminate, wherein the ratio: (ie) / (iie) of the crystal melting enthalpy (ie) to the crystal melting enthalpy (iie) calculated for the melting point peak (ii) is 0.5 or less.

Effects of the Invention

[0014] According to the present invention, by the extrusion lamination method, a laminate containing a poly(3-hydroxyalkanoate)-based resin layer having good surface properties can be produced with good productivity.

Embodiments for Carrying Out the Invention

[0015] The embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. The present invention relates to a method for manufacturing a laminate having a base material layer and a resin layer containing a poly(3-hydroxyalkanoate) resin.

[0016] The manufacturing method includes a step of introducing an intermediate composition (I) containing a poly(3-hydroxyalkanoate) resin into an extruder equipped with a die at its tip, melting it in the extruder, extruding it onto the surface of the base material layer from the die outlet, and then cooling and solidifying it to form the resin layer and obtain the laminate. The intermediate composition (I) can be obtained by melting a raw material composition containing a poly(3-hydroxyalkanoate) resin and then cooling and solidifying it. First, the components that may be contained in the raw material composition or the intermediate composition (I) will be described.

[0017] [Poly(3-hydroxyalkanoate) resin] The poly(3-hydroxyalkanoate) resin (hereinafter also referred to as P3HA) is a general term for polymers containing at least 3-hydroxyalkanoate units as monomer units. The 3-hydroxyalkanoate unit is preferably represented by the following general formula (1). [-CHR-CH 2 -CO-O-] (1)

[0018] In general formula (1), R represents an alkyl group represented by C p H 2p+1 and p represents an integer from 1 to 15. Examples of R include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, methylpropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, and hexyl group. As p, 1 to 10 is preferable, and 1 to 8 is more preferable.

[0019] The 3-hydroxyalkanoic acid constituting P3HA is not particularly limited, and examples thereof include 3-hydroxybutanoic acid, 3-hydroxypropionic acid, 3-hydroxypentanoic acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, and the like. Only one of these may be used, or two or more thereof may be used in combination.

[0020] P3HA may be a homopolymer or copolymer composed of at least one 3-hydroxyalkanoate unit, or may be a copolymer containing at least one 3-hydroxyalkanoate unit and other hydroxyalkanoate units (for example, 4-hydroxyalkanoate units such as 4-hydroxybutanoate units).

[0021] P3HA preferably contains 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more of 3-hydroxyalkanoate units (particularly, units represented by the general formula (1)) based on all constituent units (monomer units).

[0022] As P3HA, P3HA produced from microorganisms is particularly preferred. In P3HA produced from microorganisms, 3-hydroxyalkanoate units are all contained as (R)-3-hydroxyalkanoate units.

[0023] Only one type of P3HA may be used, or two or more types may be used in combination, but as described later, a combination of two or more types is preferred.

[0024] The raw material composition or intermediate composition (I) containing P3HA preferably contains 50% by weight or more of P3HA, more preferably 70% by weight or more, still more preferably 80% by weight or more, and even more preferably 90% by weight or more. By using P3HA as the main component, good biodegradability can be exhibited.

[0025] [Poly(3-hydroxybutyrate)-based copolymer (A)] The raw material composition or intermediate composition (I) containing P3HA preferably contains, as P3HA, at least a poly(3-hydroxybutyrate) - based copolymer (A) containing 3-hydroxybutyrate (hereinafter sometimes referred to as 3HB) units and other hydroxyalkanoate units.

[0026] The other hydroxyalkanoate units may be 3-hydroxyalkanoate units other than 3HB units, or may be hydroxyalkanoate units other than 3-hydroxyalkanoate units (for example, 4-hydroxyalkanoate units). Only one kind of the other hydroxyalkanoate units may be included, or two or more kinds may be included.

[0027] Specific examples of the poly(3-hydroxybutyrate) - based copolymer (A) 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), 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), poly(3-hydroxybutyrate - co - 4-hydroxybutyrate) (abbreviation: P3HB4HB), etc. In particular, from the viewpoints of the productivity of the laminate and the mechanical properties of the resin layer, etc., poly(3-hydroxybutyrate - co - 3-hydroxyhexanoate) or poly(3-hydroxybutyrate - co - 4-hydroxybutyrate) is preferable, and poly(3-hydroxybutyrate - co - 3-hydroxyhexanoate) is particularly preferable.

[0028] As the poly(3-hydroxybutyrate) copolymer (A), a copolymer produced from microorganisms is particularly preferred. In the copolymer produced from microorganisms, all of the 3-hydroxyalkanoate units constituting the copolymer are contained as (R)-3-hydroxyalkanoate units.

[0029] From the viewpoints of the productivity of the laminate and the mechanical properties of the resin layer, the poly(3-hydroxybutyrate) copolymer (A) preferably contains at least two types of poly(3-hydroxybutyrate) copolymers having different crystallinities, and more preferably contains at least two types of poly(3-hydroxybutyrate) copolymers having different types of constituent monomers and / or different content ratios of the constituent monomers.

[0030] Specifically, the poly(3-hydroxybutyrate) copolymer (A) preferably contains a copolymer (A1) of a 3-hydroxybutyrate unit and another hydroxybutyrate unit, in which the content ratio of the other hydroxybutyrate unit is 1 to 5 mol%, and a copolymer (A2) of a 3-hydroxybutyrate unit and another hydroxybutyrate unit, in which the content ratio of the other hydroxybutyrate unit is 24 mol% or more. According to such a resin composition, a laminate including a resin layer having good surface properties and mechanical properties can be produced with good productivity by an extrusion lamination method.

[0031] Regarding the copolymers (A1), (A2), and (A3) described below, the "content ratio of the other hydroxybutyrate unit" refers to the content ratio of the other hydroxybutyrate unit in the total of the 3-hydroxybutyrate unit and the other hydroxybutyrate unit.

[0032] In addition to the copolymer (A1) and the copolymer (A2), it is more preferable to further contain a copolymer (A3) of a 3-hydroxybutyrate unit and another hydroxybutyrate unit, in which the content ratio of the other hydroxybutyrate unit is 6 mol% or more and less than 24 mol%. According to this, it becomes easier to balance the surface properties of the resin layer and the productivity of the laminate.

[0033] The copolymer (A1) is a highly crystalline poly(3-hydroxybutyrate)-based resin, while the copolymer (A2) is a low-crystalline poly(3-hydroxybutyrate)-based resin. The copolymer (A3) is a medium-crystalline poly(3-hydroxybutyrate)-based resin with crystallinity intermediate between that of the copolymer (A1) and the copolymer (A2).

[0034] Generally, a highly crystalline poly(3-hydroxybutyrate)-based resin has excellent productivity but poor mechanical properties, while a low-crystalline poly(3-hydroxybutyrate)-based resin has poor productivity but excellent mechanical properties. By using a combination of the above-described two or three types of resins, a resin layer excellent in the balance between productivity and mechanical properties can be formed.

[0035] The content ratio of other hydroxyalkanoate units in the copolymer (A1) is 1 mol% or more and 5 mol% or less. From the viewpoint of the productivity of the laminate, the lower limit of the ratio is preferably 2 mol% or more. The upper limit is preferably 4 mol% or less.

[0036] As the copolymer (A1), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferable, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferable.

[0037] The content ratio of other hydroxyalkanoate units in the copolymer (A2) is 24 mol% or more. From the viewpoint of the mechanical properties of the resin layer, the lower limit of the ratio is preferably 26 mol% or more, more preferably 28 mol% or more. Also, from the viewpoint of the productivity of the copolymer (A2), the upper limit of the ratio is preferably 99 mol% or less, more preferably 50 mol% or less, still more preferably 40 mol% or less, and particularly preferably 30 mol% or less.

[0038] As the copolymer (A2), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferable, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferable.

[0039] The usage ratio of the copolymer (A1) and the copolymer (A2) is not particularly limited. However, from the viewpoints of the productivity of the copolymer (A2) and the balance between the productivity of the laminate and the mechanical properties of the resin layer, the weight ratio of the copolymer (A1) to the copolymer (A2): (A1) / (A2) is preferably 0.5 or more and 2.0 or less. The lower limit of the weight ratio is preferably 0.7 or more. Also, the upper limit is preferably 1.7 or less, and more preferably 1.5 or less.

[0040] The content ratio of other hydroxyalkanoate units in the copolymer (A3) is 6 mol% or more and less than 24 mol%. From the viewpoints of the surface property of the resin layer and the productivity of the laminate, the upper limit of the ratio is preferably 20 mol% or less, and more preferably 15 mol% or less. The lower limit of the ratio is preferably 8 mol% or more, and more preferably 10 mol% or more.

[0041] As the copolymer (A3), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferable, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferable.

[0042] Of the total of copolymer (A1), copolymer (A2), and copolymer (A3), the proportion of copolymer (A3) is preferably 5 to 45% by weight from the viewpoint of the balance between the productivity of the laminate and the mechanical properties of the resin layer. By setting the proportion of copolymer (A3) to 5% by weight or more, the productivity of the laminate can be improved. Further, by setting the proportion to 45% by weight or less, good mechanical properties can be imparted to the resin layer. The lower limit of the proportion is preferably 10% by weight or more, more preferably 15% by weight or more. Also, the upper limit of the proportion is preferably 40% by weight or less, more preferably 35% by weight or less.

[0043] [Poly(3-hydroxybutyrate) (B)] The raw material composition or intermediate composition (I) containing P3HA preferably contains poly(3-hydroxybutyrate) (B) as P3HA in addition to the poly(3-hydroxybutyrate)-based copolymer (A). Thereby, the solidification rate of the resin in the second step can be increased more, and the productivity of the laminate can be increased more.

[0044] Poly(3-hydroxybutyrate) (B) refers to a homopolymer of 3-hydroxybutyrate, but may contain a small amount of monomer units other than 3-hydroxybutyrate units. Specifically, in poly(3-hydroxybutyrate) (B), the content ratio of 3-hydroxybutyrate units in the total constituent monomers is preferably more than 99 mol% and 100 mol% or less. By blending the poly(3-hydroxybutyrate) (B), the solidification rate of the whole P3HA can be increased, and the productivity of the laminate can be improved.

[0045] As monomer units other than 3-hydroxybutyrate units contained in poly(3-hydroxybutyrate) (B), there are no particular limitations as long as copolymerization with 3-hydroxybutyrate units is possible. For example, 3-hydroxyalkanoate units other than 3-hydroxybutyrate units and hydroxyalkanoate units other than 3-hydroxyalkanoate units (e.g., 4-hydroxyalkanoate units) can be mentioned. Specific examples include the units described above for P3HA.

[0046] The content of poly(3-hydroxybutyrate) (B) can be appropriately set, but it is preferably 5% by weight or more and 25% by weight or less based on 100% by weight of the total amount of P3HA. When the content is 5% by weight or more, the solidification rate of P3HA containing poly(3-hydroxybutyrate) (B) can be increased, productivity can be improved, and it becomes easy to manufacture a laminate at high speed. The lower limit of the content is more preferably 8% by weight or more, further preferably 10% by weight or more, and particularly preferably 15% by weight or more. Also, when the content is 25% by weight or less, the surface properties of the resin layer can be further improved. The upper limit is more preferably 23% by weight or less.

[0047] From the viewpoint of achieving both the mechanical properties of the resin layer and the productivity of the laminate, the average content ratio of 3-hydroxybutyrate units and other hydroxyalkanoate units in all monomer units constituting the entire P3HA contained in the raw material composition or intermediate composition (I) is preferably 3-hydroxybutyrate units / other hydroxyalkanoates = 93 / 7 to 80 / 20 (mol% / mol%), more preferably 92 / 8 to 81 / 18 (mol% / mol%), and further preferably 90 / 10 to 82 / 16 (mol% / mol%).

[0048] The average content ratio of each monomer unit in all monomer units constituting the entire P3HA 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.

[0049] The weight-average molecular weight of P3HA is not particularly limited, but from the viewpoint of achieving both the mechanical properties of the resin layer and the productivity of the laminate, it is preferably from 200,000 to 2,000,000, more preferably from 250,000 to 1,500,000, and still more preferably from 300,000 to 1,000,000.

[0050] Also, the weight-average molecular weights of the copolymer (A1), the copolymer (A2), the copolymer (A3), and poly(3-hydroxybutyrate) (B) are not particularly limited. However, from the viewpoint of achieving both the mechanical properties of the resin layer and the productivity of the laminate, the weight-average molecular weights of the copolymer (A1) and poly(3-hydroxybutyrate) (B) are each preferably from 200,000 to 1,000,000, more preferably from 220,000 to 800,000, and still more preferably from 250,000 to 700,000. On the other hand, from the viewpoint of achieving both the mechanical properties of the resin layer and the productivity of the laminate, the weight-average molecular weights of the copolymer (A2) and the copolymer (A3) are each preferably from 200,000 to 2,500,000, more preferably from 250,000 to 2,300,000, and still more preferably from 300,000 to 2,000,000.

[0051] The weight-average molecular weight of P3HA, the copolymer (A1), the copolymer (A2), the copolymer (A3), or poly(3-hydroxybutyrate) (B) can be measured in terms of polystyrene using gel permeation chromatography (HPLC GPC system manufactured by Shimadzu Corporation) using a chloroform solution. As the column in the gel permeation chromatography, a column suitable for measuring the weight-average molecular weight may be used.

[0052] The method for producing P3HA is not particularly limited and may be a production method by chemical synthesis or a production method by microorganisms. Among them, the production method by microorganisms is preferred. For the production method by microorganisms, known methods can be applied. For example, as copolymer-producing bacteria of 3-hydroxybutyrate and other hydroxyalkanoates, Aeromonas caviae, which is a P3HB3HV and P3HB3HH-producing bacterium, and Alcaligenes eutrophus, which is a P3HB4HB-producing bacterium, are known. In particular, regarding P3HB3HH, in order to increase the productivity of P3HB3HH, Alcaligenes eutrophus AC32 strain (Alcaligenes eutrophus AC32, FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, p4821-4830 (1997)) into which the genes of the P3HA synthase group have been introduced is more preferred, and microbial cells in which P3HB3HH has been accumulated in the cells by culturing these microorganisms under appropriate conditions are used. In addition to the above, depending on the P3HA to be produced, genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used, or the culture conditions including the type of substrate may be optimized.

[0053] The method for obtaining a blend of two or more types of P3HA 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. Further, two or more types of resins may be melt-kneaded using an extruder, a kneader, a Banbury mixer, a roll, etc. to obtain a blend, or two or more types of resins may be dissolved in a solvent, mixed, and dried to obtain a blend.

[0054] (Organic peroxide) P3HA may be unmodified P3HA. However, modified P3HA into which a crosslinked structure has been introduced by reacting P3HA with an organic peroxide can also be used. When using modified P3HA, neck-in after melt extrusion can be more effectively suppressed.

[0055] The organic peroxide is not particularly limited. For example, diisobutyl peroxide, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis(4-t-butylcyclohexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, disuccinic peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butyl peroxy 2-ethylhexyl carbonate, t-butyl peroxyisopropyl carbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-amyl peroxy 3,5,5-trimethylhexanoate, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 2,2-di-t-butylperoxybutane, etc. can be mentioned. Among them, dibenzoyl peroxide, t-butyl peroxy 2-ethylhexyl carbonate, and t-butyl peroxyisopropyl carbonate are preferable. As the organic peroxide, one kind may be used alone, or two or more kinds may be used in combination.

[0056] Organic peroxides are used in various forms such as solid or liquid, and may be in a liquid form diluted with a diluent or the like. Among them, organic peroxides in a form that can be mixed with P3HA, particularly organic peroxides that are liquid at room temperature (25°C), are preferred because they can be uniformly dispersed in P3HA and it is easy to suppress local denaturation reactions.

[0057] From the perspective of suppressing neck-in, the amount of the organic peroxide used is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of P3HA. More preferably, it is 0.03 to 0.5 part by weight, and still more preferably, it is 0.05 to 0.3 part by weight.

[0058] The modified P3HA can preferably be obtained by charging P3HA and an organic peroxide into an extruder and melt-kneading them when producing the intermediate composition (I). Thereby, P3HA can be crosslinked uniformly.

[0059] (Other resins) The raw material composition or the intermediate composition (I) may contain other resins other than P3HA as long as the effects of the invention are not impaired. Examples of such other resins include aliphatic polyester resins such as polybutylene succinate adipate, polybutylene succinate, polycaprolactone, and polylactic acid, and aliphatic aromatic polyester resins such as polybutylene adipate terephthalate, polybutylene sebacate terephthalate, and polybutylene azelate terephthalate. Only one kind of other resin may be contained, or two or more kinds may be contained.

[0060] The content of the other resin is not particularly limited, but it is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less, and particularly preferably 5 parts by weight or less with respect to 100 parts by weight of the total amount of P3HA. It may also be 1 part by weight or less. The lower limit of the content of the other resin is not particularly limited and may be 0 parts by weight.

[0061] (Plasticizer) The raw material composition or intermediate composition (I) preferably contains a plasticizer in addition to P3HA. By blending a plasticizer, the productivity of the laminate can be improved.

[0062] The plasticizer is not particularly limited, but from the viewpoint of compatibility with P3HA, it is preferable to use an ester compound having an ester bond in the molecule.

[0063] Examples of the ester compound that can be used as the plasticizer include modified glycerin-based compounds, dibasic acid ester-based compounds, adipic acid ester-based compounds, polyether ester-based compounds, benzoic acid ester-based compounds, citric acid ester-based compounds, isosorbide ester-based compounds, polycaprolactone-based compounds, and the like. Among them, modified glycerin ester-based compounds, dibasic acid ester-based compounds, adipic acid ester-based compounds, polyether ester-based compounds, or isosorbide ester-based compounds are preferable. Further, as the ester compound, one kind can be used alone, or two or more kinds can be used in combination. When two or more kinds are used in combination, the mixing ratio of these ester compounds can be appropriately adjusted.

[0064] As the modified glycerin-based compound, a glycerin ester-based compound is preferable. As the glycerin ester-based compound, any of monoester, diester, or triester of glycerin can be used, but from the viewpoint of compatibility with P3HA, a triester of glycerin is preferable. Among the triesters of glycerin, glycerin diacetomonostearate is particularly preferable. Specific examples of glycerin diacetomonostearate include glycerin diacetomonolaurate, glycerin diacetomonoolate, glycerin diacetomonostearate, glycerin diacetomonocaprylate, glycerin diacetomonodecanoate, and the like. Examples of the modified glycerin-based compound include the "Rikemal" PL series and "BIOCIZER" of Riken Vitamin Co., Ltd.

[0065] Specific examples of the dibasic acid ester compounds include dibutyl adipate, diisobutyl adipate, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis[2-(2-butoxyethoxy)ethyl] adipate, bis[2-(2-butoxyethoxy)ethyl] adipate, bis(2-ethylhexyl) azelate, dibutyl sebacate, bis(2-ethylhexyl) sebacate, diethyl succinate, mixed-base dibasic acid ester compounds, and the like.

[0066] Examples of the adipic acid ester compounds include diethylhexyl adipate, dioctyl adipate, diisononyl adipate, and the like.

[0067] Examples of the polyether ester compounds include polyethylene glycol dibenzoate, polyethylene glycol dicaprylate, polyethylene glycol diisostearate, and the like.

[0068] As the ester compound, a modified glycerin-based compound is preferable from the viewpoints of excellent cost and versatility, as well as high biomass content. Particularly from the viewpoint of food contact, glycerin triesters are more preferable, glycerin diacetate monoesters are even more preferable, and glycerin diacetate monolaurate is particularly preferable.

[0069] The blending amount of the plasticizer can be appropriately set in consideration of the mechanical properties of the resin layer and the productivity of the laminate. However, it is preferably 0.1 part by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the total amount of P3HA. The lower limit of the blending amount of the plasticizer is preferably 1 part by weight or more, more preferably 2 parts by weight or more, and even more preferably 3 parts by weight or more. The upper limit is preferably 8 parts by weight or less, more preferably 6 parts by weight or less.

[0070] (Additive) The above-mentioned raw material composition or intermediate composition (I) may contain additives as long as the effects of the invention are not inhibited. Examples of the additives include crystallization nucleating agents, lubricants, antistatic agents, flame retardants, conductive agents, heat insulating agents, antioxidants, ultraviolet absorbers, colorants, inorganic fillers, organic fillers, hydrolysis inhibitors, etc., which can be used according to the purpose. In particular, biodegradable additives are preferred.

[0071] Examples of the crystallization nucleating agents include sugar alcohols such as pentaerythritol, galactitol, mannitol; orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, boron nitride, etc. Among them, sugar alcohols are preferred, and pentaerythritol is particularly preferred in that it has an especially excellent effect of promoting the crystallization of P3HA.

[0072] The amount of the crystallization 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 based on 100 parts by weight of the total amount of P3HA. Also, one kind of crystallization nucleating agent may be used, or two or more kinds may be used, and the usage ratio can be appropriately adjusted according to the purpose.

[0073] However, the above-mentioned raw material composition or intermediate composition (I) may not substantially contain sugar alcohols such as pentaerythritol. Not substantially containing sugar alcohols means that the content of sugar alcohols is less than 0.1 part by weight based on 100 parts by weight of the total amount of P3HA. It may be less than 0.01 part by weight. In the mode of not substantially containing sugar alcohols, the problem of bleed-out of sugar alcohols from the resin layer and the accompanying contamination of the manufacturing equipment can be avoided.

[0074] When substantially free of sugar alcohols, it is preferable to blend a fatty acid amide and / or a layered clay mineral as a crystal nucleating agent. In particular, it is preferable to blend both a fatty acid amide and a layered clay mineral. By using these crystal nucleating agents in combination with poly(3-hydroxybutyrate) (B), even when substantially free of sugar alcohols, the productivity of the laminate can be improved.

[0075] Specific examples of the fatty acid amide are as detailed below as a lubricant. The fatty acid amide can function as both a crystal nucleating agent and a lubricant.

[0076] The layered clay mineral is not particularly limited, and known ones can be used. However, from the viewpoint of easily achieving an improvement in the productivity of the laminate and a neck-in reduction effect, one or more selected from the group consisting of smectite, mica, talc, pyrophyllite, vermiculite, chlorite, kaolinite, and serpentine are preferable. From the viewpoint of versatility, mica, talc, and kaolinite are preferable, and talc is particularly preferable.

[0077] Examples of the mica include wet-ground mica and dry-ground mica. Examples of the talc include general-purpose talc and surface-treated talc. Examples of the kaolinite include dry kaolin, calcined kaolin, and wet kaolin.

[0078] The blending amount of the layered clay mineral is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, and even more preferably 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the total amount of P3HA.

[0079] Examples of the lubricant include behenic acid amide, oleic acid amide, erucic acid amide, stearic acid amide, palmitic acid amide, N-stearyl behenic acid amide, N-stearyl erucic acid amide, ethylene bis stearic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, ethylene bis lauric acid amide, ethylene bis capric acid amide, p-phenylene bis stearic acid amide, polycondensate of ethylenediamine, stearic acid and sebacic acid, and the like. Among them, behenic acid amide and erucic acid amide are preferred in that they have particularly excellent lubricant effects on P3HA and can improve the productivity of the laminate.

[0080] The amount of the lubricant used is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, and still more preferably 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the total amount of P3HA. Also, one kind of lubricant may be used, or two or more kinds may be used, and the usage ratio can be appropriately adjusted according to the purpose.

[0081] The raw material composition containing P3HA may be a blend of each component, or may be homogenized by heating and melting after mixing each component. The shape of the raw material composition used in the first step is not particularly limited, and may be, for example, pellets or powder.

[0082] [Step of obtaining intermediate composition (I): First step] In the step of obtaining the intermediate composition (I) containing the poly(3-hydroxyalkanoate) resin (also referred to as the first step), after heating and melting the raw material composition containing P3HA, it is cooled and solidified to produce the intermediate composition (I) having specific melting characteristics. When heating and melting the raw material composition, a general processing machine can be used. Such a processing machine is not particularly limited, and known ones can be used. Examples include a Banbury mixer, a roll mill, a kneader, a single-screw or multi-screw extruder, and the like. In particular, it is preferable to use an extruder.

[0083] In this embodiment, the intermediate composition (I) has at least a melting point peak (i) with a peak temperature of 170°C or higher in differential scanning calorimetry. This melting point peak indicates that a high melting point P3HA resin component is contained in the intermediate composition (I).

[0084] Since the intermediate composition (I) has a melting point peak (i) in a high temperature region of 170°C or higher, when the intermediate composition (I) is melt-extruded in the following second step, while the entire intermediate composition (I) melts to a level where melt-extrusion is possible, the high melting point P3HA resin component can remain without melting.

[0085] In this way, the resin component that has not melted in the molten resin acts as a crystal nucleating agent during cooling and solidification, making it easier for the molten resin to crystallize and solidify, and improving the solidification property after melt-extrusion in the second step. Therefore, even if the production speed of the extrusion laminate is increased, the adhesion of the resin layer to the cooling roll is suppressed, and the productivity of the laminate can be improved.

[0086] In addition, since the resin component that has not melted is contained in the molten resin, the molten resin after being discharged from the die is less likely to sag, so it becomes possible to suppress neck-in after melt-extrusion in the second step.

[0087] The peak temperature of the melting point peak (i) only needs to be 170°C or higher, but from the viewpoint of further enhancing the productivity of the laminate, it is preferably 171°C or higher, more preferably 172°C or higher, and even more preferably 173°C or higher. The upper limit of the peak temperature of the melting point peak (i) is not particularly limited, but from the viewpoint of ease of production of the laminate, it is preferably 200°C or lower, more preferably 190°C or lower, and even more preferably 185°C or lower.

[0088] Furthermore, the intermediate composition (I) shows a crystal melting enthalpy (ie) of 0.5 J / g or more calculated for the melting point peak (i) in differential scanning calorimetry. This means that the intermediate composition (I) contains a corresponding amount of a high melting point P3HA resin component. As a result, the solidification property after melt extrusion in the second step is improved, and the productivity of the laminate can be enhanced. Also, neck-in after melt extrusion in the second step can be suppressed. When the crystal melting enthalpy (ie) is less than 0.5 J / g, the resin layer is likely to stick to the cooling roll, making it difficult to increase the productivity of the laminate. Also, neck-in cannot be sufficiently suppressed.

[0089] From the viewpoint of improving solidification property, the larger the crystal melting enthalpy (ie) calculated for the melting point peak (i), the more preferable it is, preferably 1 J / g or more, more preferably 2 J / g or more, and even more preferably 3 J / g or more. The upper limit value is not particularly limited, but from the viewpoint of facilitating melting of the entire intermediate composition (I), it is preferably 20 J / g or less, more preferably 15 J / g or less, and even more preferably 10 J / g or less.

[0090] In addition, the intermediate composition (I) further has a melting point peak (ii) with a peak temperature of 140°C or more and less than 170°C in differential scanning calorimetry, in addition to the melting point peak (i). The melting point peak (ii) indicates that the intermediate composition (I) contains a P3HA resin component with a melting point lower than that of the melting point peak (i). Since this low melting point P3HA resin component is relatively easy to melt, this makes it easier to melt the intermediate composition (I) to a level where melt extrusion is possible in the second step.

[0091] The peak temperature of the melting point peak (ii) may be 140°C or more and less than 170°C, but from the viewpoint of easy production, it is preferably 145°C or more and less than 166°C, and more preferably 150°C or more and less than 160°C.

[0092] Also, the difference between the peak temperature of the melting peak (i) and the peak temperature of the melting peak (ii) is not particularly limited. However, from the perspective that while the entire intermediate composition (I) melts to a level where melt processing is possible, it is easier for the high-melting-point P3HA resin component to remain without melting, it is preferably 5°C or higher, more preferably 10°C or higher, and even more preferably 12°C or higher. The upper limit of the temperature difference is not particularly limited, but from the perspective of ease of production, it is preferably 60°C or lower, more preferably 40°C or lower, and even more preferably 25°C or lower.

[0093] In the intermediate composition (I), the ratio of the crystal melting enthalpy (ie) calculated for the melting peak (i) to the crystal melting enthalpy (iie) calculated for the melting peak (ii): (ie) / (iie) is 0.5 or less. When the ratio exceeds 0.5, the content of the high-melting-point P3HA resin component becomes relatively large, and the resin component that does not melt during melt extrusion becomes excessive. As a result, convex portions caused by the resin component are scattered on the surface of the resin layer, and the surface property of the resin layer may be impaired. Furthermore, when the resin component that does not melt during melt extrusion becomes excessive, the resin layer after extrusion lamination becomes difficult to stretch and is prone to breakage, so it may be difficult to increase the production speed of extrusion lamination. The ratio is preferably 0.48 or less, more preferably 0.46 or less. Also, the lower limit of the ratio is not particularly limited, but it is preferably 0.01 or more.

[0094] The differential scanning calorimetry of the intermediate composition (I) can be carried out by the method detailed in the Examples section. Also, the crystal melting enthalpy calculated for the melting peak (i) or (ii) can be calculated as detailed in the Examples section.

[0095] To obtain the intermediate composition (I) exhibiting the melting characteristics as described above, it is preferable to control the temperature such that the maximum temperature reached by the raw material composition during heating and melting in the first step falls within the range of 140°C or higher and 185°C or lower. The lower limit of the maximum temperature is preferably 145°C or higher, more preferably 150°C or higher, and even more preferably 155°C or higher. On the other hand, the upper limit is preferably 180°C or lower, more preferably 175°C or lower, and even more preferably 170°C or lower.

[0096] Furthermore, to obtain the intermediate composition (I) exhibiting the melting characteristics described above, it is more preferable to set the maximum temperature reached by the raw material composition during heating and melting in the first step to a temperature that is equal to or higher than the melting point peak temperature and equal to or lower than the end temperature of the melting point peak in the differential scanning calorimetry measured for the raw material composition before heating and melting. Thereby, during the heating and melting in the first step, a part of the crystals of P3HA can be left without being melted, and due to this, it becomes easier to form a new melting point peak (i) on the higher temperature side than the melting point peak possessed by the raw material composition.

[0097] The maximum temperature of the raw material composition described above does not refer to the set temperature in a processing machine such as an extruder, but rather refers to the actual maximum temperature exhibited by the material during heating and melting, taking into account the temperature increased due to shear heating. The maximum temperature during heating and melting can be measured, for example, for the material discharged from the die of an extruder. Since the maximum temperature during heating and melting can vary depending on the set temperature (cylinder or die set temperature) in the extruder, the screw configuration of the extruder, the rotation speed, etc., it can be controlled by appropriately adjusting these.

[0098] In addition, in order to control the maximum temperature during the heat melting in the first step to be a temperature equal to or higher than the melting point peak temperature of the raw material composition before heat melting and equal to or lower than the end temperature of the melting point peak, it is preferable that the raw material composition has a broad melting point peak in the differential scanning calorimetry measured for the entire P3HA contained in the composition. Specifically, it is preferable that the difference between the melting point peak temperature and the end temperature of the melting point peak is 10°C or higher. As described above, P3HA having such a broad melting point peak can be constituted by using two or more types of P3HA having different monomer compositions in combination.

[0099] In addition, in order to form the melting point peak (i) in the intermediate composition (I) and increase the crystal melting enthalpy (ie) of the melting point peak (i), it is also desirable to control the production rate of the intermediate composition (I). If the production rate of the intermediate composition (I) is too high, the melting point peak (i) may not be formed, or the crystal melting enthalpy (ie) of the melting point peak (i) may not reach a sufficient value.

[0100] As described above, after heating and melting the raw material composition, the intermediate composition (I) can be obtained by cooling and solidifying it by a conventional method. The shape of the intermediate composition (I) is not particularly limited, and it may be, for example, a pellet or a powder.

[0101] [Second Step: Step of Obtaining a Laminate] In the step of obtaining a laminate (also referred to as the second step), the above-described intermediate composition (I) is put into an extruder equipped with a die at the tip, melted in the extruder, extruded from the die outlet onto the surface of the base material layer, and then cooled and solidified to form the resin layer and manufacture the laminate. Note that the intermediate composition (I) may be manufactured by the laminate manufacturer itself, or a product obtained from others may be used. First, the base material layer will be described.

[0102] The base material layer is not particularly limited as long as it is a layer on which a resin layer can be laminated, but it is preferably a biodegradable layer. Thereby, the entire laminate including the resin layer will have biodegradability, which is more advantageous as a material for solving the problem of marine pollution.

[0103] The biodegradable base material layer is not particularly limited. For example, it includes paper (the main component is cellulose), cellophane, cellulose ester; polyvinyl alcohol, polyamino acid, polyglycolic acid, pullulan, or those obtained by depositing inorganic substances such as aluminum and silica on these base materials. Among them, paper is preferred because of its excellent heat resistance and low cost. The type of paper is not particularly limited, and examples include cup base paper, kraft paper, high-quality paper, coated paper, tissue paper, glassine paper, cardboard, etc. The type of paper can be appropriately selected according to the use of the laminate. Water repellents, water repellents, inorganic substances, etc. may be added to the paper as necessary, or it may be a surface-treated product such as an oxygen barrier layer coating or a water vapor barrier coating.

[0104] The base material layer may be subjected to surface treatments such as corona treatment, plasma treatment, ozone treatment, flame treatment, and anchor coat treatment. These surface treatments may be performed alone or in combination of a plurality of surface treatments. In particular, by subjecting the base material layer to corona treatment inline in extrusion lamination and laminating a resin layer on the base material layer, the adhesion strength between the resin layer and the base material layer can be increased.

[0105] In the second step, first, it is preferable to sufficiently dry the intermediate composition (I) at about 40 to 80 ° C as necessary to remove moisture. Then, if necessary, any other resin or additive as described above can be appropriately blended, put into an extruder, and heated and melted.

[0106] In the second step, the maximum temperature reached by the intermediate composition (I) during heating and melting in the extruder is preferably 160 ° C or higher, more preferably 165 ° C or higher. By heating and melting under such temperature conditions, the entire intermediate composition (I) containing a high melting point resin component can be sufficiently melted, and a resin layer with high uniformity, good surface properties, and good mechanical properties can be formed. The upper limit of the maximum temperature is not particularly limited, but from the viewpoint of avoiding resin decomposition, it is preferably 180 ° C or lower, more preferably 175 ° C or lower.

[0107] Further, it is more preferable that the maximum temperature reached by the intermediate composition (I) during the heat melting in the second step is higher than the maximum temperature reached by the raw material composition during the heat melting in the first step. Thereby, in the first step, while newly forming the melting point peak (i), in the second step, the entire intermediate composition (I) showing the melting point peak (i) can be sufficiently melted.

[0108] Furthermore, it is preferable to control the temperature so that the maximum temperature reached by the intermediate composition (I) during the heat melting in the second step is the temperature showing the maximum value of the differential scanning calorimetry curve between the peak temperature of the melting point peak (i) of the intermediate composition (I) and the peak temperature of the melting point peak (ii) of the intermediate composition (I). According to this, the productivity of the laminate including the poly(3-hydroxyalkanoate)-based resin-containing layer can be further enhanced, and the surface property of the resin layer can be made better.

[0109] The maximum temperature of the intermediate composition (I) does not refer to the set temperature in a processing machine such as an extruder, similar to the maximum temperature of the above-described raw material composition, but refers to the actual maximum temperature shown by the material during heat melting, taking into account the temperature increased by shear heating.

[0110] In the method for manufacturing a laminate according to the present disclosure, it is preferable that the residence time of the intermediate composition (I) in the extruder in the second step is within 10 minutes. Since the residence time in the extruder is short, thermal degradation of the resin can be suppressed to a minimum.

[0111] In the present embodiment, the extrusion lamination method can be carried out as follows. A resin component is melted by an extruder equipped with a T-die at the tip, and after extruding the film-shaped molten resin from the outlet of the T-die onto the surface of a base material, the molten resin is pressure-bonded to the base material using a cooling roll and cooled and solidified to form a resin layer. Immediately thereafter, the laminate is obtained by peeling the resin layer from the cooling roll. This manufacturing method can be continuously carried out while feeding the base material from a feeding roll and conveying it, and while winding the manufactured laminate onto a winding roll.

[0112] The surface temperature of the cooling roll is not particularly limited as long as it is a temperature at which the resin layer can be peeled off after cooling and pressure bonding. For example, it is preferably 40 to 70°C, more preferably 50 to 65°C. Within such a range, the crystallization and solidification of P3HA are likely to be promoted. As a result, sticking to the cooling roll is suppressed, and the productivity of the extrusion laminate can be increased.

[0113] As the cooling roll, a metal roll can be preferably used. However, in order to improve the releasability, a roll whose surface has been subjected to blasting treatment or release coating treatment may be used. Examples of the release coating treatment include fluorine-based coating, ceramic coating, Tosical coat (registered trademark of Tosico Co., Ltd.), and the like.

[0114] The thickness of the resin layer to be formed is not particularly limited. However, from the viewpoint of preventing water absorption into the base material layer and ensuring sufficient flexibility, it is preferably about 5 to 300 μm, more preferably 10 to 200 μm.

[0115] In the method for manufacturing a laminate according to the present disclosure, since the extrusion lamination method is carried out using the intermediate composition (I) having specific melting characteristics, it becomes possible to manufacture a laminate including a poly(3-hydroxyalkanoate)-based resin-containing layer at high speed. Specifically, as the production speed in the second step, 10 m / min or more can be achieved. Further, 20 m / min or more, or 30 m / min or more can be achieved. The upper limit is not particularly limited and may be, for example, 60 m / min or less.

[0116] 〔Laminate〕 One aspect of the present embodiment may be a laminate that can be manufactured by the above-described manufacturing method. The laminate includes a base material layer and a resin layer containing a poly(3-hydroxyalkanoate)-based resin. The resin layer is laminated on at least one side of the base material layer. Since the surface property of the resin layer of this laminate is good, it is advantageous in various applications.

[0117] In this laminate, the resin layer may be laminated only on one side of the base material layer or on both sides. The resin layer may be laminated on the base material layer via another layer, or may be directly laminated on the base material layer without passing through another layer. Further, another layer may be laminated on the resin layer.

[0118] 〔Molded article〕 One aspect of the present embodiment may be a molded article including the laminate. Since this molded article is formed from a laminate having good surface properties of the resin layer, it is advantageous in various applications.

[0119] This molded article is not particularly limited as long as it includes the laminate, and examples thereof include paper, film, sheet, tube, plate, rod, container (e.g., bottle container), bag, parts, etc. From the viewpoint of countermeasures against marine pollution, this molded article is preferably a bag or a bottle container.

[0120] This molded article may be the laminate itself or may be a secondary processed product of the laminate. By subjecting this laminate to secondary processing, the molded article including it can be suitably used as various packaging container materials such as shopping bags, various bags, food and confectionery packaging materials, cups, trays, cartons, etc. (in other words, in various fields such as food, cosmetics, electronics, medical, pharmaceuticals, etc.). Since this laminate contains a resin composition having high adhesiveness to the base material and good heat resistance, it is more preferable as a container for containing liquids, particularly as a container for hot contents such as cups for food and beverages such as instant noodles, instant soups, coffee, etc., trays for side dishes, box lunches, microwave foods, etc.

[0121] The secondary processing can be performed using any method known in the art, such as various bag-making machines, filling and packaging machines, etc. It can also be processed using devices such as paper tray press molding machines, paper cup molding machines, punching machines, and enclosing machines. In these processing machines, known techniques can be used for the bonding method of the molded body. In addition to the normal heat-sealing method, for example, impulse sealing method, ultrasonic sealing method, high-frequency sealing method, hot air sealing method, frame sealing method, etc. can be used. The heat-sealing can be carried out between the base material layer and the resin layer, or between the resin layers.

[0122] When heat-sealing the resin layers of the laminate, the heat-sealing temperature, using a heated heat-sealing tester with a sealing bar and heating both sides, is usually 150 - 200°C, preferably 160 - 190°C, more preferably 170 - 180°C. When heat-sealing the resin layer and the base material layer of the laminate, the heat-sealing temperature, using a heated heat-sealing tester with a sealing bar and heating both sides, is usually 160 - 220°C, preferably 170 - 210°C, more preferably 180 - 200°C. Within the above ranges, it is possible to avoid the melting out of the resin near the seal part and ensure an appropriate film thickness of the resin layer and the seal strength.

[0123] The heat-sealing pressure when heat-sealing the laminate varies depending on the bonding method. The heat-sealing pressure of the molded body, when using a heated heat-sealing tester with a sealing bar, is usually 0.1 MPa or more, preferably 0.3 MPa or more. When it is above the above value, sufficient adhesive strength by heat-sealing can be ensured.

[0124] In order to improve the physical properties of the molded body according to this embodiment, it can also be compounded with another molded body (for example, fibers, threads, ropes, woven fabrics, knitted fabrics, non-woven fabrics, paper, films, sheets, tubes, plates, rods, containers, bags, parts, foams, etc.) composed of a material different from the molded body. These materials are also preferably biodegradable.

[0125] The film, laminate, or molded article according to this embodiment can be suitably used in the fields of agriculture, fishery, forestry, horticulture, medicine, hygiene products, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

[0126] In the following items, preferred embodiments in the present disclosure are listed, but the present invention is not limited to the following items. [Item 1] A method for manufacturing a laminate having a base material layer and a resin layer containing a poly(3-hydroxyalkanoate) resin, comprising: Putting an intermediate composition (I) containing a poly(3-hydroxyalkanoate) resin into an extruder equipped with a die at the tip, melting it in the extruder, extruding it onto the surface of the base material layer from the die outlet, and then cooling and solidifying to form the resin layer to obtain the laminate. The intermediate composition (I) has a melting point peak (i) with a peak temperature of 170°C or higher and a melting point peak (ii) with a peak temperature of 140°C or higher and lower than 170°C in differential scanning calorimetry. The crystal melting enthalpy (ie) calculated for the melting point peak (i) is 0.5 J / g or more. A method for manufacturing a laminate, wherein the ratio of the crystal melting enthalpy (ie) to the crystal melting enthalpy (iie) calculated for the melting point peak (ii): (ie) / (iie) is 0.5 or less. [Item 2] The method for manufacturing a laminate according to Item 1, wherein the crystal melting enthalpy (ie) is 10 J / g or less. [Item 3] The method for manufacturing a laminate according to Item 1 or 2, wherein the difference between the peak temperature of the melting point peak (i) and the peak temperature of the melting point peak (ii) is 5°C or more. [Item 4] The method for manufacturing a laminate according to any one of Items 1 to 3, wherein the maximum temperature of the intermediate composition (I) in the step of obtaining the laminate is 160°C or higher and 180°C or lower. [Item 5] A method for manufacturing the laminate according to any one of items 1 to 4, further comprising a step of obtaining an intermediate composition (I) by melting a raw material composition containing a poly(3-hydroxyalkanoate) resin and then cooling and solidifying it. [Item 6] The method for manufacturing a laminate according to item 5, wherein the maximum temperature of the raw material composition in the step of obtaining the intermediate composition (I) is 140°C or higher and 185°C or lower. [Item 7] The method for manufacturing a laminate according to any one of items 1 to 6, wherein in the step of obtaining the laminate, the residence time of the intermediate composition (I) in the extruder is within 10 minutes. [Item 8] The method for manufacturing a laminate according to any one of items 1 to 7, wherein the maximum temperature of the intermediate composition (I) in the step of obtaining the laminate is the temperature showing the maximum value of the differential scanning calorimetry curve between the peak temperature of the melting peak (i) and the peak temperature of the melting peak (ii). [Item 9] The method for manufacturing a laminate according to any one of items 1 to 8, wherein the poly(3-hydroxyalkanoate) resin contains poly(3-hydroxybutyrate) (B). [Item 10] The method for manufacturing a laminate according to item 9, wherein the content of the poly(3-hydroxybutyrate) (B) is 5% by weight or more and 25% by weight or less based on 100% by weight of the total amount of the poly(3-hydroxyalkanoate) resin. [Item 11] The method for manufacturing a laminate according to any one of items 1 to 10, wherein the poly(3-hydroxyalkanoate) resin contains a poly(3-hydroxybutyrate) copolymer (A) containing 3-hydroxybutyrate units and other hydroxyalkanoate units.

Examples

[0127] Hereinafter, the present invention will be specifically described by way of examples, but the technical scope of the present invention is not limited by these examples.

[0128] The substances used in the examples and comparative examples are shown below. [Poly(3-hydroxyalkanoate) resin] PHB: Poly(3-hydroxybutyrate) (weight-average molecular weight is 300,000 g / mol) It was produced according to the method described in Comparative Example 1 of International Publication No. 2004 / 041936. P3HB3HH-3: P3HB3HH (average content ratio 3HB / 3HH = 97.9 / 2.1 mol% / mol%), weight-average molecular weight is 660,000 g / mol) It was produced according to the method described in International Publication No. 2019 / 142845. P3HB3HH-6: P3HB3HH (average content ratio 3HB / 3HH = 95 / 5 mol% / mol%), weight-average molecular weight is 440,000 g / mol) It was produced according to the method described in International Publication No. 2008 / 010296. P3HB3HH-6L: P3HB3HH (average content ratio 3HB / 3HH = 95 / 5 mol% / mol%), weight-average molecular weight is 340,000 g / mol) It was produced according to the method described in International Publication No. 2008 / 010296. P3HB3HH-11: P3HB3HH (Kaneka biodegradable polymer PHBH (registered trademark) (average content ratio 3HB / 3HH = 87.1 / 12.9 (mol% / mol%), weight-average molecular weight is 330,000 g / mol) P3HB3HH-28: P3HB3HH (average content ratio 3HB / 3HH = 73.6 / 26.4 (mol% / mol%), weight-average molecular weight is 660,000 g / mol) It was produced according to the method described in Example 9 of International Publication No. 2019 / 142845.

[0129] [Additive] Additive-1: Behenic acid amide (manufactured by Nippon Fine Chemical Co., Ltd., BNT-22H) Additive-2: Talc (manufactured by Nippon Talc Co., Ltd., SG200N15) Plasticizer-1: Biosizer (manufactured by Riken Vitamin Co., Ltd., glycerin diacetomonolaurate)

[0130] [Organic peroxide] D-1: Nippon Oil Corporation's Perbutyl I (tributyl peroxyisopropyl monocarbonate, half-life temperature: 158.8 °C for 1 minute)

[0131] The evaluation methods carried out in the examples and comparative examples will be described below. [Measurement of melting peak temperature and crystal melting enthalpy in differential scanning calorimetry] Using a differential scanning calorimeter (NETCH DSC Polyma214 type), about 2 mg of the pellet-like intermediate composition (I) containing the poly(3-hydroxyalkanoate) resin obtained in each example or comparative example was weighed, and the temperature was raised from 0 °C to 180 °C at a heating rate of 10 °C / min. The temperature of the melting point peak was determined from the DSC curve obtained. Also, in the DSC curve, for each melting point peak above 100 °C, the baseline before the start of the melting point peak and after the end of the melting point peak was connected by a straight line, and the heat quantity calculated as the area of the melting region surrounded by the straight line and the DSC curve was taken as the crystal melting enthalpy (J / g) calculated for that melting point peak.

[0132] [Take-up property] The degree of adhesion of the laminate layer to the cooling roll of the laminating machine during the production of the laminate was visually evaluated. ◎: At a take-up speed of 30 m / min, it was released without sticking to the entire surface, and even when the take-up speed was increased to 35 m / min, it was released without sticking to the entire surface 〇: At a take-up speed of 30 m / min, it was released without sticking to the entire surface △: At a take-up speed of 30 m / min, although partial adhesion was observed, it was released ×: At a take-up speed of 30 m / min, it could not be released while sticking to the cooling roll, or the laminate layer broke and the laminate could not be produced

[0133] [Surface property] The laminate layer of the laminate was visually evaluated according to the following criteria. 〇: Almost no convex portions derived from the resin solid content were observed on the surface, and it was generally smooth. △: Locally, convex portions derived from the resin solid content were observed on a part of the surface. ×: Many convex portions derived from the resin solid content are observed on the entire surface.

[0134] (Example 1) [Preparation of Intermediate Composition (I)] To a blend of 20 parts by weight of PHB, 30 parts by weight of P3HB3HH-3, 10 parts by weight of P3HB3HH-6, 10 parts by weight of P3HB3HH-11, and 30 parts by weight of P3HB3HH-28, 1 part by weight of Additive-1, 1 part by weight of Additive-2, and 1 part by weight of Plasticizer-1 were added and further blended. The obtained resin material (resin mixture) was charged into a φ26 mm co-rotating twin-screw extruder with both the cylinder temperature and the die temperature set at 157 °C (the molding temperature of the intermediate product (I)), and extruded at a rotational speed of 30 rpm and a strand take-up speed of the resin material (the molding speed of the intermediate product (I)) of 5 kg / hour. The extruded resin material was passed through a water tank filled with water at 40 °C to solidify the strand, and cut with a pelletizer to obtain pellet-shaped intermediate composition (I). The melting peak temperature and the crystal melting enthalpy in differential scanning calorimetry were measured for the obtained intermediate composition (I), and the results are shown in Table 1.

[0135] [Manufacture of Laminated Body by Extrusion Lamination Method] The pellet-shaped intermediate composition (I) was charged into a single-screw extruder equipped with a T-die, and extruded from the T-die under the condition that the resin temperature immediately after extrusion (the maximum temperature of the intermediate composition (I)) was 170 °C. The cooling roll temperature was 60 °C and the take-up speed was 30 m / min, and laminated on the surface of a paper base material (base paper with a basis weight of 210 g / m 2 to obtain a laminated body with a thickness of 30 μm. The take-up property of the obtained laminated body and the surface property of the laminated layer of the obtained laminated body were evaluated, and the results are shown in Table 1.

[0136] (Examples 2 to 9, Comparative Examples 1 to 7) A pellet-shaped intermediate composition (I) and a laminate were produced in the same manner as in Example 1, except that the formulation of the resin composition and the production conditions of the intermediate composition (I) were changed as shown in Table 1, and the same evaluation as in Example 1 was carried out. The results are summarized in Table 1. However, in Comparative Example 1, the intermediate composition (I) was not produced, and an extrusion laminate was carried out in the same manner as in Example 1 using a blend of each component to produce a laminate. The melting point peak temperature and the crystal melting enthalpy were also measured for the blend.

[0137] [Table 1]

[0138] It can be seen from Table 1 that in Examples 1 to 9, a laminate having a laminate layer with good surface properties could be produced at a high take-up speed of 30 m / min. On the other hand, in Comparative Examples 1, 4, and 6 where extrusion lamination was carried out using a composition without a melting peak (i), production of the laminate at a take-up speed of 30 m / min was not possible due to poor mold release during extrusion lamination. Also, in Comparative Examples 2, 3, 5, and 7 where the crystal melting enthalpy ratio (ie) / (iie) exceeded 0.5, the surface properties of the laminate layer of the obtained laminate were insufficient. In addition, in Comparative Examples 2 and 5, production of the laminate at a take-up speed of 30 m / min was not possible because the laminate layer broke during extrusion lamination.

Claims

1. A method for producing a laminate having a base layer and a resin layer containing a poly(3-hydroxyalkanoate)-based resin, comprising the steps of: The method includes a step of feeding an intermediate composition (I) containing a poly(3-hydroxyalkanoate)-based resin into an extruder equipped with a die at its tip, melting the intermediate composition in the extruder, extruding the intermediate composition (I) from the die outlet onto the surface of the base layer, and then cooling and solidifying the intermediate composition (I) to form the resin layer and obtain the laminate, The intermediate composition (I) has, in a differential scanning calorimetry analysis, a melting point peak (i) having a peak temperature of 170° C. or more and a melting point peak (ii) having a peak temperature of 140° C. or more and less than 170° C., The crystalline melting enthalpy (ie) calculated for the melting point peak (i) is 0.5 J / g or more; A method for producing a laminate, wherein a ratio of the crystalline melting enthalpy (ie) to the crystalline melting enthalpy (iiie) calculated for the melting point peak (ii): (ie) / (iiie) is 0.5 or less.

2. The method for producing a laminate according to claim 1 , wherein the crystalline melting enthalpy (ie) is 10 J / g or less.

3. The method for producing a laminate according to claim 1 or 2, wherein a difference between a peak temperature of the melting peak (i) and a peak temperature of the melting peak (ii) is 5°C or more.

4. The method for producing a laminate according to claim 1 or 2, wherein the maximum temperature of the intermediate composition (I) in the step of obtaining the laminate is 160°C or higher and 180°C or lower.

5. The method for producing a laminate according to claim 1 or 2, further comprising the step of melting a raw material composition containing a poly(3-hydroxyalkanoate) resin, and then cooling and solidifying the raw material composition to obtain an intermediate composition (I).

6. The method for producing a laminate according to claim 5, wherein the maximum temperature of the raw material composition in the step of obtaining the intermediate composition (I) is 140°C or higher and 185°C or lower.

7. The method for producing a laminate according to claim 1 or 2, wherein in the step of obtaining the laminate, the residence time of the intermediate composition (I) in the extruder is 10 minutes or less.

8. 3. The method for producing a laminate according to claim 1 or 2, wherein the maximum temperature of the intermediate composition (I) in the step of obtaining the laminate is a temperature showing a maximum value of a differential scanning calorimetry curve between the peak temperature of the melting point peak (i) and the peak temperature of the melting point peak (ii).

9. 3. The method for producing a laminate according to claim 1, wherein the poly(3-hydroxyalkanoate)-based resin contains poly(3-hydroxybutyrate) (B).

10. The method for producing a laminate according to claim 9, wherein the content of the poly(3-hydroxybutyrate) (B) is 5% by weight or more and 25% by weight or less in a total amount (100% by weight) of the poly(3-hydroxyalkanoate)-based resin.

11. The method for producing a laminate according to claim 1 or 2, wherein the poly(3-hydroxyalkanoate)-based resin contains a poly(3-hydroxybutyrate)-based copolymer (A) containing 3-hydroxybutyrate units and other hydroxyalkanoate units.

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