WO2019239913A1

WO2019239913A1 - Method for manufacturing biodegradable laminate

Info

Publication number: WO2019239913A1
Application number: PCT/JP2019/021569
Authority: WO
Inventors: 宏司刀禰; 大倉　徹雄
Original assignee: 株式会社カネカ
Priority date: 2018-06-14
Filing date: 2019-05-30
Publication date: 2019-12-19
Also published as: JPWO2019239913A1; JP7353280B2

Abstract

A method in which a pressure-bonding surface is used to pressure-bond a resin material to a paper substrate, and then the resin material is removed from the pressure-bonding surface, whereby a biodegradable laminate configured from the paper substrate and a resin layer is manufactured, wherein the resin material contains (A) 100 parts by weight of polyhydroxyalkanoate that includes repeating units represented by the following formula: (-CHR-CH₂-CO-O) (in the formula, R is an alkyl group represented by C_nH_2n+1, and n is an integer of 1-15), and (B) 1-20 parts by weight of a glycerol ester compound.

Description

Method for producing biodegradable laminate

The present invention relates to a method for producing a biodegradable laminate comprising a paper base and a resin layer, a method for improving the surface state of the resin layer, and a biodegradable laminate.

Poly (3-hydroxyalkanoate) resin (Poly (3-hydroxyalkanoate); hereinafter abbreviated as “P3HA”) is a heat produced and stored as an energy storage substance in cells of many microbial species. It is a plastic polyester. P3HA is completely biodegraded by microorganisms in the soil and water, and is easily biodegraded in the natural environment such as the ocean and is taken into the natural carbon cycle process. Therefore, it can be said that P3HA is an environmentally friendly plastic that has almost no adverse effect on the ecosystem.

Such a laminated paper produced by laminating P3HA on a paper base material is an extremely promising laminated paper from the viewpoint of environmental protection because both paper and P3HA are environmentally degradable materials.

Generally, laminated paper is manufactured by laminating a paper base material and a resin material by extrusion lamination or heat lamination. However, P3HA tends to adhere to the cooling roll during laminating, and a large force is applied when peeling from the roll to form fine irregularities on the surface of the resin layer, resulting in white turbidity and deterioration of the appearance of the resin layer. was there. Moreover, since the peelability from the roll is poor, there is also a problem that continuous lamination over a long time becomes difficult.

In order to solve such a problem, for the purpose of avoiding contact between P3HA and the cooling roll, a P3HA and a polyolefin resin are coextruded on a paper base material to form a three-layer laminate, A method for producing a laminated paper composed of a paper base material and a P3HA layer by peeling a polyolefin resin layer from a laminate is known. However, in this method, since the polyolefin resin film peeled from the laminate is discarded, there is a problem in terms of waste treatment.

In Patent Document 1, cooling is achieved by producing a three-layer biodegradable laminate by coextruding P3HA, a polycondensation polyester of dicarboxylic acid and glycol having good processability on a paper base material. It describes preventing blocking to rolls. Patent Document 2 describes that a blocking of a cooling roll is prevented by extruding a mixture of P3HA and a polycondensation polyester or polylactic acid on a paper base material.

However, since the polycondensation polyester and polylactic acid used in Patent Document 1 and Patent Document 2 are resins having low environmental degradability, they were undesirable components for providing laminated paper having environmental degradability. .

Japanese Patent Laid-Open No. 10-6444 Japanese Patent Laid-Open No. 10-6445

In view of the above situation, the present invention can produce a biodegradable laminate by laminating a paper base material and P3HA, without using a resin material with low environmental degradability. An object of the present invention is to produce a biodegradable laminate that improves the peelability of the resin layer, has a good surface condition, and has high environmental degradability.

As a result of intensive studies to solve the above problems, the inventors of the present invention blended a predetermined amount of glycerin ester compound with P3HA, and constituted a resin layer with this blend, so that from a pressure bonding surface such as a cooling roll. It has been found that a biodegradable laminate having a good surface state can be produced by improving the peelability of the resin layer of the present invention.

That is, the present invention provides a biodegradable laminate composed of the paper base material and the resin layer by pressure-bonding the resin material to the paper base material using the pressure-bonding surface and then peeling the resin material from the pressure-bonding surface. In which the resin material has the formula (A): [—CHR—CH ₂ —CO—O—] (wherein R is an alkyl group represented by C _n H _{2n + 1} , n Is a resin material containing 100 parts by weight of a polyhydroxyalkanoate containing a repeating unit represented by (1) to 15 parts by weight, and (B) 1 to 20 parts by weight of a glycerin ester compound. The present invention relates to a method for manufacturing a laminate. Preferably, the resin composition further contains 0.1 to 5 parts by weight of (C) an aliphatic amide compound. Preferably, the polyhydroxyalkanoate is a copolymer of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid. Preferably, the step of pressure-bonding the resin material to the paper substrate using the pressure-bonding surface is performed by extruding the molten resin material into a film shape by an extrusion laminating method and then cooling and pressure-bonding to the separately-rolled paper substrate with a cooling roller. It is a process. Preferably, the take-off force when peeling the resin material from the pressure-bonding surface is 25 N or less.

In the present invention, the pressure-bonding surface is used to select [—CHR—CH ₂ —CO—O—] (wherein R is an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 or more and 15 or less. The paper substrate and the resin produced by peeling the resin material from the pressure-bonding surface after pressure-bonding the resin material containing the polyhydroxyalkanoate containing the repeating unit represented by A method for improving the surface state of the resin layer in a biodegradable laminate composed of layers, comprising 1 to 20 parts by weight of glycerin ester per 100 parts by weight of the polyhydroxyalkanoate relative to the resin material The present invention also relates to a method for improving the surface state of a resin layer, which comprises blending a compound.

Furthermore, the present invention is a biodegradable laminate in which a resin layer is laminated on one side or both sides of a paper substrate, wherein the resin layer is represented by the formula (A): [—CHR—CH ₂ —CO—O—] ( In the formula, R is an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 or more and 15 or less.) 100 parts by weight of a polyhydroxyalkanoate including a repeating unit represented by: and (B) glycerin The present invention also relates to a biodegradable laminate containing 1 to 20 parts by weight of an ester compound. Preferably, the biodegradable laminate has a form wound in a roll shape.

According to the present invention, when a biodegradable laminate is produced by laminating a paper base material and P3HA, the resin layer can be peeled from the pressure-bonding surface such as a cooling roll without using other resin materials. It is possible to produce a biodegradable laminate that is improved and has a good surface condition and high environmental degradability. Furthermore, according to the present invention, it is possible to stably carry out a continuous laminating process for a long time.

Hereinafter, embodiments of the present invention will be described in detail.

(Polyhydroxyalkanoate (A))
In the biodegradable laminate composed of the paper base material and the resin layer according to the present invention, the main resin material constituting the resin layer is a poly (3-hydroxyalkanoate) resin, specifically, a formula : Containing a repeating unit represented by [—CHR—CH ₂ —CO—O—] (wherein R is an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 or more and 15 or less). Polyhydroxyalkanoate.

The repeating unit represented by the formula contained in the P3HA may be only one type or two or more types. In the latter case, the type of copolymerization is not particularly limited and may be random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, or the like, but random copolymerization is preferred because it is easily available.

The repeating unit constituting the P3HA may be only the repeating unit represented by the above formula, or may contain other repeating units in addition to the repeating unit represented by the above formula. Other repeating units include 4-hydroxyalkanoate units such as 4-hydroxybutyrate units.

Specific examples of P3HA include poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyhexanoate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate) Poly (3-hydroxybutyrate-co-4-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyoctanoate), poly (3-hydroxybutyrate-co-3-hydroxyoctanoate) Decanoate) and the like. Among them, since production is easy industrially, poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyhexanoate), poly (3-hydroxybutyrate-co-) 3-hydroxyvalerate) and poly (3-hydroxybutyrate-co-4-hydroxybutyrate) are preferred.

Furthermore, by changing the composition ratio of the repeating units, the melting point and crystallinity can be changed, and physical properties such as Young's modulus and heat resistance can be changed, and physical properties between polypropylene and polyethylene can be imparted. From the viewpoint that it is possible to produce and industrially easy to produce and is a physically useful plastic as described above, poly (3) which is a copolymer of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid is used. 3-hydroxybutyrate-co-3-hydroxyhexanoate) is preferred. The poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) has poor peelability from the pressure-bonding surface at the time of laminating among P3HA, and the surface state of the resin layer of the resulting laminated paper is deteriorated. Although the problem of being easy is remarkable, the application of the present invention can improve the surface condition of a laminated paper using poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) as a resin material. it can.

A specific method for producing poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) is described in, for example, International Publication No. 2010/013483. Examples of commercially available products of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) include Kaneka Corporation “Kaneka Biodegradable Polymer PHBH” (registered trademark).

The composition ratio of the repeating unit of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) is determined from the viewpoint of the balance between flexibility and strength, 3-hydroxybutyrate unit / 3-hydroxyhexanoate The composition ratio of units is preferably 80/20 to 99/1 (mol / mol), and more preferably 85/15 to 97/3 (mo1 / mo1). The reason is that 99/1 or less is preferable from the viewpoint of flexibility, and 80/20 or more is preferable in that the resin has an appropriate hardness.

The weight average molecular weight of P3HA used in the present invention (hereinafter sometimes referred to as Mw) is not particularly limited, but is preferably 100,000 to 2.5 million, more preferably 150,000 to 2 million, and further preferably 200,000 to 1 million. preferable. If the weight average molecular weight is less than 100,000, the mechanical properties and the like may be inferior, and if it exceeds 2.5 million, molding may be difficult. In the present application, the weight average molecular weight of P3HA is determined by gel permeation chromatography (GPC) (“Shodex GPC-101” manufactured by Showa Denko KK) and polystyrene gel (“Shodex K-804” manufactured by Showa Denko KK) as a column. It can be determined as the molecular weight when converted to polystyrene using chloroform as the mobile phase.

In the resin layer constituting the biodegradable laminate of the present invention, P3HA can be used alone or in combination of two or more.

In the resin layer, an aliphatic polyester resin such as polybutylene succinate adipate, polybutylene succinate, and polylactic acid, and an aliphatic aromatic polyester type such as polybutylene adipate terephthalate, as long as the effects of the present invention are not impaired. One or more biodegradable resins other than P3HA, such as a resin, may be contained.

However, since biodegradable resins other than P3HA have low environmental degradability in normal environments such as soil and ocean, the use of these may reduce the environmental degradability of the biodegradable laminate. For this reason, the content of the resin other than P3HA is preferably as small as possible so as not to inhibit the environmental degradability of P3HA. Specifically, the content of the resin other than P3HA is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and still more preferably 10 parts by weight or less with respect to 100 parts by weight of P3HA. Moreover, the resin layer which comprises the biodegradable laminated body of this invention may contain only P3HA as a resin component, ie, may not contain resin other than P3HA at all.

(Glycerin ester compound (B))
In the present invention, the resin layer constituting the biodegradable laminate is composed of a resin composition in which a glycerin ester compound is blended with P3HA, thereby improving the peelability from the pressure-bonding surface such as a cooling roll in lamination. The resin layer hardly adheres to the pressure-bonding surface, and the resin layer can be smoothly peeled off from the pressure-bonding surface, so that a biodegradable laminate having a good surface condition can be produced.

The glycerin ester compound is a compound in which a hydroxyl group of glycerin forms an ester bond with a compound having a carboxyl group, for example. The ester compound may be a glycerol monoester, a glycerol diester, or a glycerol triester. From the viewpoint of improving peelability from the pressure-bonding surface, a triester of glycerin is preferred, and glycerin diacetate monoester is more preferred. Specific examples of glycerol diacetomonoester include glycerol diacetomonolaurate, glycerol diacetomonooleate, glycerol diacetomonostearate, glycerol diacetomonocaprylate, glycerol diacetomonodecanoate and the like. Only one type of glycerin ester compound may be used, or a plurality may be used in combination.

The blending amount of the glycerin ester compound in the resin composition is 1 to 20 parts by weight with respect to 100 parts by weight of P3HA. When the blending amount of the glycerin ester compound is less than 1 part by weight, it becomes difficult to obtain the effect of improving the peelability from the crimping surface. When the blending amount is more than 20 parts by weight, the glycerin ester compound bleeds during crimping, and the cooling roll There is a problem that it becomes difficult to perform continuous processing for a long time because it adheres to the pressure-bonding surface. The blending amount of the glycerin ester compound is preferably 1 to 10 parts by weight, more preferably 2 to 5 parts by weight.

(Aliphatic amide compound (C))
The resin composition constituting the biodegradable laminate of the present invention may contain an aliphatic amide compound in addition to P3HA and a glycerin ester compound. By mix | blending an aliphatic amide compound, the peelability from a crimping | compression-bonding surface can further be improved. However, the aliphatic amide compound is an optional component, and the resin composition may not contain an aliphatic amide compound.

An aliphatic amide compound is a kind of additive conventionally known as a lubricant added to a resin. The aliphatic amide compound is not particularly limited, and examples thereof include saturated or unsaturated fatty acid amides such as lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, and erucic acid amide. And alkylene fatty acid amides such as methylene bis stearic acid amide and methylene bis stearic acid amide. Of these, fatty acid amides are preferred from the viewpoint of improving the peelability from the crimping surface. Only one type of aliphatic amide compound may be used, or a plurality of types may be used in combination.

The blending amount of the aliphatic amide compound in the resin layer is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of P3HA. By setting the blending amount of the aliphatic amide compound to 0.1 parts by weight or more, the effect of improving the peelability by blending the aliphatic amide compound can be obtained. However, when the blending amount of the aliphatic amide compound exceeds 5 parts by weight, the aliphatic amide compound bleeds at the time of pressure bonding and adheres to the pressure-bonding surface such as a cooling roll, which makes it difficult to perform continuous processing for a long time. The blending amount of the aliphatic amide compound is more preferably 0.3 to 4 parts by weight, still more preferably 0.5 to 3 parts by weight.

(Pentaerythritol (D))
The resin layer constituting the biodegradable laminate of the present invention may contain pentaerythritol in addition to P3HA and a glycerin ester compound. By blending pentaerythritol, the peelability from the pressure-bonded surface can be further improved. However, pentaerythritol is an optional component, and the resin layer may not contain pentaerythritol.

The blend amount of pentaerythritol in the resin layer is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of P3HA. By setting the blending amount of pentaerythritol to 0.1 parts by weight or more, it is possible to obtain an effect of improving peelability by blending pentaerythritol. However, when the blending amount of pentaerythritol exceeds 5 parts by weight, there is a problem that pentaerythritol bleeds at the time of pressure bonding and adheres to the pressure-bonding surface such as a cooling roll, making long-time continuous processing difficult. The blending amount of pentaerythritol is more preferably 0.3 to 4 parts by weight, still more preferably 0.5 to 3 parts by weight.

In the resin layer, in addition to the glycerin ester compound, the optional component aliphatic amide compound, and the optional component pentaerythritol, other additives usually added to the resin material as long as the effects of the present invention are not impaired. For example, inorganic fillers, colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolite, fragrances such as vanillin and dextrin, plasticizers, antioxidants, antioxidants, weather resistance improvers, ultraviolet absorbers In addition, one or more kinds of crystal nucleating agents, lubricants, mold release agents, water repellents, antibacterial agents, slidability improving agents, and other secondary additives may be added. The content of these additives can be set as appropriate.

The thickness of the resin layer in the biodegradable laminate of the present invention (each resin layer in the case where the biodegradable laminate has two or more resin layers) is not particularly limited, but prevents water absorption to paper. However, from the viewpoint of ensuring sufficient flexibility, the thickness is preferably 5 to 300 μm, more preferably 10 to 200 μm.

(Paper substrate)
The paper base material which comprises the biodegradable laminated body of this invention is not specifically limited, What is necessary is just to be able to form the resin layer in the single side | surface or both surfaces. Specific examples include kraft paper, fine paper, coated paper, thin paper, glassine paper, paperboard, glassine paper, cellophane, and the like. What is necessary is just to select the kind of paper base material according to the use of a biodegradable laminated body. Further, the surface of the paper base material may be subjected to a surface treatment such as a corona treatment, a frame treatment, or an anchor coat treatment.

(Lamination method)
In this invention, the biodegradable laminated body comprised from the paper base material and the resin layer formed in the single side | surface or both surfaces is manufactured by the lamination method. The laminating method is a method in which a resin material is pressure-bonded to a paper substrate using a pressure-bonding surface such as a cooling roll, and then a resin layer composed of the resin material is peeled off from the pressure-bonding surface, whereby a biodegradable laminate is obtained. It is a manufacturing method. The laminating method is not particularly limited as long as it is a method in which a resin material and a paper base material are pressure-bonded using a pressure-bonding surface. Specifically, after the molten resin material is extruded from a T-die into a film shape, it is separately fed out. Examples thereof include an extrusion laminating method in which a paper base is cooled and pressure-bonded using a cooling roll, and a heat laminating method in which a resin film prepared in advance is heated and pressure-bonded to the paper base. Here, the pressure-bonding surface is not particularly limited as long as the resin and the paper base material can be pressure-bonded, and examples thereof include a plate-shaped surface and a roll surface.

The extrusion laminating method is carried out continuously, and a melted resin material is cooled and pressure-bonded to a paper substrate, and immediately thereafter, the resin layer is peeled off from the cooling roll. Therefore, in the conventional method, when P3HA is used as the resin material, the resin layer is not easily peeled off from the cooling roll, and the phenomenon that the resin layer is temporarily attached to the cooling roll is likely to occur. As a result, the problem that the force applied when the adhesion location peeled from the roll and the cloudy nonuniformity (fine unevenness | corrugation) produced on the resin layer surface in the said location had generate | occur | produced especially notably. However, by applying the present invention, even in the extrusion laminating method, it is possible to improve the peelability from the cooling roll and produce a biodegradable laminate having a good surface state of the resin layer. According to the present invention, it is possible to reduce the take-up force when peeling a resin material containing P3HA from a pressure-bonding surface such as a cooling roll, preferably to 25 N or less, more preferably to 20 N or less.

In addition, according to the present invention, other resins such as a polyolefin resin layer and a polycondensation polyester layer of dicarboxylic acid and glycol are formed on the P3HA layer as in the conventional method in order to avoid contact between the P3HA layer and the pressure-bonding surface. There is no need to provide a separate layer. Therefore, the problem of the waste treatment mentioned above and the problem that the resin material having low environmental degradability is included in the biodegradable laminate can also be avoided.

In the extrusion laminating method, 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 cooled and pressure-bonded, and can be appropriately determined, but may be in the range of 10 to 60 ° C., for example.

(Biodegradable laminate)
Moreover, this invention is also a biodegradable laminated body containing the paper base material and the resin layer formed in the single side | surface or both surfaces. The resin layer is a resin layer containing the above-described P3HA and a glycerin ester compound as essential components. The biodegradable laminate of the present invention is laminated so that the resin layer is in contact with the paper substrate, and an adhesive layer and other resin layers are interposed between the resin layer and the paper substrate. It is preferable that it is not. Further, the biodegradable laminate of the present invention has a resin layer other than the resin layer mainly composed of P3HA in the present invention (for example, a polyolefin resin layer or a layer composed of a polycondensation polyester of dicarboxylic acid and glycol). It is preferable that it does not contain.

The biodegradable laminate of the present invention is preferably a long biodegradable laminate continuously produced by the above-described laminating method, and is wound around a winding roll after pressure bonding and peeling by the laminating method. It is preferable that it is a biodegradable laminated body which has the form wound by roll shape which can be manufactured by.

The use of the biodegradable laminate of the present invention is not particularly limited, and examples thereof include paper cups, paper bags, cartons, trays, and interior wallpaper.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Production Example 1>
For culture production, the KNK-631 strain (see International Publication No. 2009/145164) was used.

The composition of Tanehaha medium 1w / v% Meat-extract, 1w / v% Bacto-Tryptone, 0.2w / v% Yeast-extract, 0.9w / v% Na 2 HPO 4 · 12H 2 O, 0.15w / V% KH ₂ PO ₄ (pH 6.8).

The composition of the preculture medium is 1.1 w / v% Na ₂ HPO ₄ · 12H ₂ O, 0.19 w / v% KH ₂ PO ₄ , 1.29 w / v% (NH ₄ ) ₂ SO ₄ , 0.1 w / _{_{v% MgSO 4 · 7H 2 O}} , 0.5v / v% trace metal salt solution (1.6 w in 0.1N HCl _{_{/ v% FeCl 3 · 6H 2}} O, 1w / v% CaCl 2 · 2H 2 O, 0 0.02 w / v% CoCl ₂ .6H ₂ O, 0.016 w / v% CuSO ₄ .5H ₂ O, 0.012 w / v% NiCl ₂ .6H ₂ O). As a carbon source, palm kernel oil was added all at a concentration of 10 g / L.

The composition of the P3HA production medium is 0.385 w / v% Na ₂ HPO ₄ · 12H ₂ O, 0.067 w / v% KH ₂ PO ₄ , 0.291 w / v% (NH ₄ ) ₂ SO ₄ , 0.1 w / v% MgSO ₄ .7H ₂ O, 0.5 v / v% trace metal salt solution (1.6 W / v% FeCl ₃ .6H ₂ O in 0.1N hydrochloric acid, 1 w / v% CaCl ₂ .2H ₂ O, 0 0.02 w / v% CoCl ₂ · 6H ₂ O, 0.016 w / v% CuSO ₄ · 5H ₂ O, 0.012 w / v% NiCl ₂ · 6H ₂ O), 0.05 w / v% BIOSPUREX 200K (Antifoamer: manufactured by Cognis Japan).

First, a glycerol stock (50 μl) of KNK-631 strain was inoculated into a seed medium (10 ml) and cultured for 24 hours to perform seed culture. Next, 1.0 v / v% of the seed mother culture solution was inoculated into a 3 L jar fermenter (MDL-300 type, manufactured by Maruhishi Bioengine) containing 1.8 L of a preculture medium. The operating conditions were a culture temperature of 33 ° C., a stirring speed of 500 rpm, an aeration rate of 1.8 L / min, and the culture was performed for 28 hours while controlling the pH between 6.7 and 6.8. A 14% aqueous ammonium hydroxide solution was used for pH control.

Next, the preculture solution was inoculated at 1.0 v / v% into a 10 L jar fermenter (MDS-1000, manufactured by Marubishi Bioengineer) containing 6 L of P3HA production medium. The operating conditions were a culture temperature of 28 ° C., a stirring speed of 400 rpm, an aeration rate of 6.0 L / min, and a pH controlled between 6.7 and 6.8. A 14% aqueous ammonium hydroxide solution was used for pH control. Palm kernel oil was used as the carbon source. Culturing was carried out for 64 hours. After completion of the cultivation, the cells were collected by centrifugation, washed with methanol, freeze-dried, and the weight of the obtained dried cells was measured.

100 ml of chloroform was added to 1 g of the obtained dried microbial cells and stirred overnight at room temperature to extract P3HA in the microbial cells. The bacterial cell residue was filtered off, concentrated with an evaporator until the total volume reached 30 ml, 90 ml of hexane was gradually added, and the mixture was allowed to stand for 1 hour with slow stirring. The precipitated P3HA was filtered off and vacuum dried at 50 ° C. for 3 hours to obtain P3HA A1.

The 3HH composition analysis of the obtained P3HA was measured by gas chromatography as follows. To 20 mg of dry P3HA, 2 ml of a sulfuric acid-methanol mixture (15:85) and 2 ml of chloroform were added and sealed, and heated at 100 ° C. for 140 minutes to obtain a methyl ester of a P3HA decomposition product. After cooling, 1.5 g of sodium bicarbonate was added little by little to neutralize it, and the mixture was allowed to stand until the generation of carbon dioxide gas stopped. After adding 4 ml of diisopropyl ether and mixing well, the mixture was centrifuged and the monomer unit composition of the polyester degradation product in the supernatant was analyzed by capillary gas chromatography. The gas chromatograph used was Shimadzu GC-17A, and the capillary column used was GL Science's Neutra Bond-1 (column length 25 m, column inner diameter 0.25 mm, liquid film thickness 0.4 μm). He was used as the carrier gas, the column inlet pressure was set to 100 kPa, and 1 μl of the sample was injected. As temperature conditions, the temperature was raised from an initial temperature of 100 to 200 ° C. at a rate of 8 ° C./min, and further from 200 to 290 ° C. at a rate of 30 ° C./min.

As a result of analysis under the above conditions, it was confirmed that the obtained P3HA A1 was poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (P (3HB-co-3HH)). The weight average molecular weight Mw measured by GPC was 740,000. The 3-hydroxyhexanoate (3HH) composition was 11.4 mol%.

<Production Example 2>
P3HA A1 obtained in Production Example 1 was treated at 120 ° C. and 100% humidity for 2 hours using a highly accelerated life test apparatus (PC-422R5E manufactured by Hirayama Seisakusho), so that P3HA A2 was treated as P (3HB-co -3HH). The weight average molecular weight Mw of P3HA A2 was 540,000, and the 3HH composition was 11.4 mol%.

<Production Example 3>
P (3HB-co-3HH) was obtained as P3HA A3 in the same manner as in Production Example 1, except that KNK-005 strain (see US Pat. No. 7,384,766) and palm oil were used as the carbon source. The weight average molecular weight Mw of P3HA A3 was 570,000, and the 3HH composition was 5.6 mol%.

<Production Example 4>
P3HA A3 obtained in Production Example 3 was treated at 120 ° C. and 100% humidity for 2 hours using a high acceleration life test apparatus (PC-422R5E manufactured by Hirayama Seisakusho), so that P (3HB- co-3HH) was obtained. The weight average molecular weight Mw of P3HA A4 was 440,000, and the 3HH composition was 5.6 mol%.

<Examples 1 to 11>
(Manufacture of biodegradable laminates)
Each component was blended at the blending ratio shown in Table 1 (the blending ratio in the table is expressed in parts by weight) using a same-direction meshing twin screw extruder (manufactured by Nippon Steel Co., Ltd .: TEX30) at a set temperature of 100 to It was melt-kneaded at 140 ° C. (exit resin temperature 160 ° C.) and a screw rotation speed of 100 rpm to obtain a biodegradable resin composition. The resin temperature was determined by directly measuring the molten resin coming out of the die with a K-type thermocouple. The biodegradable resin composition was drawn into a strand from the die and cut into a pellet.

Subsequently, after the pellets of the obtained biodegradable resin composition were sufficiently dried at 60 ° C., a single-screw extruder (Toyo Seiki Seisakusho Co., Ltd.) equipped with a T-type die having a width of 150 mm and a lip width of 0.25 mm Using a laminator (roll diameter: 100 mm) that was extruded under the conditions of molding temperature: 130 to 160 ° C., screw rotation speed: 30 rpm, and the temperature of the cooling roll was adjusted to 30 ° C. A biodegradable laminate was obtained by laminating at a thickness of 100 μm on one side of unbleached kraft paper having a basis weight of 150 g / m ² .

As P3HA, A1 obtained in Production Example 1, A2 obtained in Production Example 2, A3 obtained in Production Example 3, or A4 obtained in Production Example 4 was used.

As the glycerin ester compound B1, glycerin diacetomonolaurate (manufactured by Riken Vitamin Co., Ltd., “Riquemar PL012”) was used.

As the aliphatic amide compound C1, erucic acid amide (manufactured by Nippon Seika Co., Ltd., “Nutron-S”) was used.

As the pentaerythritol D1, pentaerythritol (manufactured by Nippon Synthetic Chemical Co., Ltd., “Neulizer P”) was used.

(Roll peelability)
The peelability from the cooling roll at the time of laminating was evaluated by measuring the force (pulling force) for pulling the laminate from the cooling roll with a force gauge (manufactured by IMADA, mechanical force gauge FB-100N). The smaller the take-off force, the better the peelability from the cooling roll. The results are shown in Table 1.

(Surface properties of the laminate)
The surface property of the biodegradable laminate after lamination was evaluated by visually observing the surface state of the laminate resin layer. If the surface of the resin layer had cloudy unevenness, it was judged as bad, and if there was no such unevenness and the surface was smooth and transparent, it was judged good. The results are shown in Table 1.

<Comparative Examples 1 to 7>
A biodegradable laminate was obtained in the same manner as in Examples 1 to 11 except that the blending ratio shown in Table 1 was followed, and the roll peelability during lamination and the surface properties of the laminate were evaluated. Is shown in Table 1.

<Reference Example 1>
A biodegradable laminate was obtained in the same manner as in Examples 1 to 11 except that the blending ratio shown in Table 1 was followed, and the roll peelability during lamination and the surface properties of the laminate were evaluated. Is shown in Table 1.

As shown in Table 1, in Examples 1 to 11 in which the glycerin ester compound was blended, the take-up force at the time of lamination was small, and the peelability from the cooling roll was good. Moreover, the surface property of each obtained biodegradable laminated body was favorable.
On the other hand, in Comparative Examples 1 to 7 in which no glycerin ester compound was used, the take-up force at the time of lamination was large and the peelability from the cooling roll was poor. Therefore, long-time continuous processing was impossible. Moreover, the surface property of each obtained biodegradable laminate was poor and could not be used as a product.

As is clear from these results, by adding the glycerin ester compound to P3HA, the peelability from the cooling roll at the time of laminating to paper is improved, and the surface property of the resulting biodegradable laminate is good. It will be a thing. In particular, Comparative Examples 1 and 3 to 7 were blended with an amide compound and / or pentaerythritol, but were not blended with a glycerin ester compound, so that the peelability from the cooling roll and the surface property of the biodegradable laminate were improved. There wasn't. From this, it can be seen that the effect of improving peelability and surface property is unique to the glycerin ester compound.

On the other hand, in Reference Example 1 in which 30 parts by weight of the glycerin ester compound was blended with 100 parts by weight of P3HA, the take-up power at the time of laminating was small and the surface property of the resulting biodegradable laminate was good. Occasionally, the glycerin ester compound bleeds into the cooling roll, and continuous processing for a long time was impossible.

Claims

A method of manufacturing a biodegradable laminate composed of the paper base material and the resin layer by peeling the resin material from the pressure-bonding surface after the resin material is pressure-bonded to the paper base material using the pressure-bonding surface. There,
The resin material is
(A) Formula: [—CHR—CH 2 —CO—O—] (wherein R is an alkyl group represented by C n H 2n + 1 , and n is an integer of 1 to 15). 100 parts by weight of polyhydroxyalkanoate containing repeating units, and
(B) A method for producing a biodegradable laminate, which is a resin material containing 1 to 20 parts by weight of a glycerin ester compound.
The production method according to claim 1, wherein the resin composition further comprises 0.1 to 5 parts by weight of (C) an aliphatic amide compound.
The production method according to claim 1 or 2, wherein the polyhydroxyalkanoate is a copolymer of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid.
The step of pressing the resin material to the paper base using the pressure-bonding surface is a step of extruding the molten resin material into a film shape by an extrusion laminating method and then cooling and press-bonding it to the paper base separately fed with a cooling roller. The production method according to any one of claims 1 to 3.
The manufacturing method according to any one of claims 1 to 4, wherein a take-off force when the resin material is peeled from the pressure-bonding surface is 25 N or less.
[-CHR—CH 2 —CO—O—] (wherein R is an alkyl group represented by C n H 2n + 1 , and n is an integer of 1 or more and 15 or less). A resin material comprising a paper base material and a resin layer, which is produced by pressure-bonding a resin material containing a polyhydroxyalkanoate containing repeating units to a paper base material and then peeling the resin material from the pressure-bonding surface. In the decomposable laminate, a method for improving the surface state of the resin layer,
A method for improving the surface state of a resin layer, wherein 1 to 20 parts by weight of a glycerin ester compound per 100 parts by weight of the polyhydroxyalkanoate is blended with the resin material.
A biodegradable laminate in which a resin layer is laminated on one or both sides of a paper substrate,
The resin layer has the formula (A): [—CHR—CH 2 —CO—O—] (wherein R is an alkyl group represented by C n H 2n + 1 , and n is an integer of 1 or more and 15 or less. And 100 parts by weight of a polyhydroxyalkanoate containing a repeating unit represented by:
(B) A biodegradable laminate comprising 1 to 20 parts by weight of a glycerin ester compound.
The biodegradable laminate according to claim 7, which has a form wound in a roll.