WO2008023721A1 - Multilayered lactic-acid-based flexible film - Google Patents

Abstract

A lactic-acid-based flexible film obtained using a lactic acid polymer as a main raw material. It suffers no blocking even when stored in a roll form, is inhibited from decreasing in molecular weight, and can be wound into a wrapping film roll having a small radius. It is a multilayered lactic-acid-based flexible film which is composed of at least three layers, and is characterized in that both surface layers each comprises a polyolefin polymer (A) as the main component and the interlayer comprises, as the main component, a lactic-acid-based resin mixture composition (B) comprising a lactic acid polymer (B-1) and a lactic acid copolymer (B-2).

Description

 Specification

 Multi-layered lactic acid soft film

 Technical field

 [0001] The present invention relates to a multilayer lactic acid-based soft film mainly composed of a lactic acid-based polymer, which is a resin derived from a natural plant, and more specifically, for example, a wrap film for food packaging, especially a small roll wrap film used at home and the like In particular, the present invention relates to a multilayer lactic acid-based soft film that can be suitably used.

 Background art

 [0002] Speaking of flexible films, shopping bags are trash bags, wrapping films for packaging food, confectionery, cosmetics, pharmaceuticals, agricultural horticultural films, greenhouse films, platemaking films, adhesive tapes, and waterproof sheets. It is used for various purposes.

 [0003] Wrapping films for food packaging, especially packaging films that can be easily packaged with food cooked at home etc. on a ceramic dish (in order to distinguish it from wrapping film for business use) Is called a “small roll wrap film”), and special conditions are required as compared with other applications, and it is not easy to produce a film suitable for this application.

 Such a small wrap film is stored in a paper box with a cutter blade wound in a cylinder. When packaging, the film is drawn out from the paper box to cover the food, and the film is covered. Is pressed against the cutter blade provided in the paper box, and the film is cut by making a perforated hole in the film with this cutter blade and tearing the film so that the tear propagates in the width direction. It is common to pack the end part in close contact with the container. For this reason, for small roll wrap film, in addition to transparency, various conditions such as tightness to the container, drawability that allows the film to be pulled out smoothly from the paper box, and suitability for cutting the drawn film are included. Is required.

[0004] Currently available small roll wrap films include films based on stretched polyvinylidene chloride resins, extruded cast polyethylene resins, plasticized polychlorinated resin, poly 4 -Methylpentene 1-based film The power to raise S.

 [0005] In recent years, due to increasing environmental problems, the effective use of drought-resistant resources has become important, and natural plant-derived resins have attracted attention. Above all, lactic acid polymers are natural plant-derived resins obtained from starches such as corn, and if they can be mass-produced, they are excellent in strength, strength, and transparency. Has been. However, since lactic acid polymers have high rigidity, it is not easy to commercialize soft films made of lactic acid polymers as main raw materials, especially wrap films for food packaging, especially small roll wrap films. There wasn't.

 [0006] Examples of a flexible film containing a lactic acid polymer as a main component include, for example, Patent Document 1, a lactic acid resin, a copolymer of a lactic acid resin and a diol'dicarboxylic acid, and a plastic having a molecular weight of 2,000 or less. A lactic acid-based soft film comprising a lactic acid-based resin composition comprising an agent, wherein the lactic acid-based resin composition has a single Tg and a storage elastic modulus at 20 ° C of 1 to 4 GPa, A lactic acid-based soft film having a storage elastic modulus at 100 ° C of 10 to; 100 MPa, loss tangent at 20 ° C of 0 .;! To 0.8 is disclosed as a household wrap film.

 [0007] Patent Document 2 discloses a method for measuring dynamic viscosity of JIS K-7198 A as a biodegradable wrap film that simultaneously has cut suitability, packaging suitability, and heat resistance, which are characteristics of household wrap films. Therefore, the storage elastic modulus at 40 ° C measured at a frequency of 10Hz and strain of 0.1% is in the range of 100MPa to 3GPa, and the storage elastic modulus at 100 ° C is in the range of 30MPa to 500MPa. The loss tangent (tan S) peak value is in the range of 0.;! To 0.8. For example, a lactic acid resin composition such as a lactic acid resin and a plasticizer is mixed in a mass ratio of 60:;! To 99: 1. A biodegradable wrap film containing a lactic acid resin composition as a main component is disclosed.

[0008] Patent Document 3 discloses a lactic acid-based soft film using a lactic acid-based resin composition comprising a lactic acid-based resin and a copolymer of lactic acid-based resin and diol'dicarboxylic acid. The Tg of the resin composition is single, and the storage elastic modulus at 20 ° C is 1 to 4 GPa, the storage elastic modulus at 100 ° C is 10 to; the loss tangent at 100 MPa and 20 ° C is 0. A lactic acid-based soft film of ~ 0.8 is disclosed as a household wrap film. [0009] In addition, Patent Document 4 discloses that a polyolefin resin is used as the outermost layer to provide a shrinkable sheet-like material that can obtain a high shrinkage rate at a relatively low temperature by an inflation method with excellent productivity. There is disclosed a shrinkable sheet-like material having at least one layer containing polylactic acid as a main component between layers containing the polyolefin resin as a main component. Further, it is disclosed that an acrylic-modified polyethylene resin is used as an adhesive layer between a layer mainly composed of a polyolefin resin and a layer mainly composed of polylactic acid.

 [0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-16605

 Patent Document 2: WO / 2005/082981

 Patent Document 3: Japanese Patent Laid-Open No. 2005-336468

 Patent Document 4: Japanese Patent Laid-Open No. 2002-19053

 Disclosure of the invention

 Problems to be solved by the invention

[0011] The lactic acid-based soft film disclosed in Patent Document 1 can be incorporated into a small-wrap film, and a plasticizer is added to a completely compatible polymer blend system of a lactic acid-based resin and a copolymer. Therefore, bleeding out of the plasticizer can be suppressed. However, if the film-formed finalome is stored in a wound state, the molecular weight of the lactic acid resin will decrease over time, or the film will block and the films will stick together. I had it.

 [0012] In addition, a lactic acid-based resin such as those obtained by blending a lactic acid-based polymer as described in Patent Documents 2 and 3 with a plasticizer, or a lactic acid-based resin, a lactic acid-based resin, and a diol'dicarboxylic acid are also used. Since the crystallization rate of the composition is slow and the glass transition point (Tg) of the lactic acid polymer is lowered to near room temperature, when a wrap film is formed by rapid cooling by casting or the like, When the sheet is crystallized, the elastic modulus is lowered. When the sheet is wound as it is, the scroll may be blocked by a tightening force or the like.

[0013] In view of such problems, the present invention is a lactic acid-based soft film made of a lactic acid-based polymer as a main raw material. ! / Although it can suppress the degree of molecular weight reduction of a lactic acid polymer that does not cause blocking, it is designed to satisfy various conditions required for food-wrapping wrap films, especially small roll wrap films. It is intended to provide a lactic acid-based soft film that can be inserted.

 Means for solving the problem

[0014] In view of power and problems, the present invention is a multilayer lactic acid-based soft film having at least three layers, both surface layers containing a polyolefin-based polymer (A) as a main component, and an intermediate layer A multilayer lactic acid-based soft film comprising a lactic acid-based mixed resin composition (B) comprising a lactic acid-based polymer (B-1) and a lactic acid-based copolymer (B-2) as a main component Propose. The invention's effect

 [0015] In the multilayer lactic acid-based soft film of the present invention, the intermediate layer serving as the nucleus of the multilayer lactic acid-based soft film is composed of a lactic acid-based polymer (B-1) and a lactic acid-based copolymer (B-2), preferably Furthermore, because it is formed with the plasticizer (C) as the main component, it is excellent in plantiness, flexibility, transparency, and biodegradability, and can satisfy various conditions required for food packaging wrap films, especially small roll wrap films. Can be built into a soft film. The intermediate layer is covered with a surface layer mainly composed of a polyolefin-based polymer (A), so that the lactic acid-based resin composition can be stored even when the formed film is stored in a rolled state. The molecular weight of the product can be prevented from lowering, and the blocking of the film can be suppressed to eliminate the problem of the films sticking to each other. Furthermore, since the surface layer can contain an antifogging agent, the antifogging property of the film can be improved.

 [0016] (Explanation of terms)

 In general, "film" is a thin flat product whose thickness is extremely small compared to its length and width and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll. (Japanese Industrial Standard JISK6900), and “sheet” is generally a thin product by definition in JIS, and usually its thickness is small and flat for the length and width. However, in the present invention where the boundary between the sheet and the finale is not clear, it is not necessary to distinguish the two in terms of the wording. Therefore, in the present invention, even when the term “film” is used, the term “sheet” is included, and the term “sheet” is used. Even in the case of doing so, “film” is included.

In addition, in the present invention, the expression “main component” includes the meaning of allowing other components to be contained within a range that does not hinder the function of the main component unless otherwise specified. Although the content ratio of the main component is not specified, the main component (two or more components are the main components) In the case of a minute, the total amount thereof) includes 50% by mass or more, preferably 70% by mass or more, and particularly preferably 80% by mass or more (including 100%). In addition, when described as “Χ to Υ” (X, 任意 is an arbitrary number), unless otherwise stated, “preferably greater than X” or “preferably Υ It also includes the intention of “smaller! /,”.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a multilayer lactic acid-based soft film (hereinafter referred to as “the present lactic acid-based soft film”) as an example of an embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.

[0018] The lactic acid-based soft film is a multilayer film having at least three layers, and both surface layers are layers containing a polyolefin polymer (重合) as a main component, and the intermediate layer is a lactic acid-based film. This layer contains a polymer (Β-1) and a lactic acid copolymer (系 -2) as main components.

[0019] The lactic acid-based soft film is preferably a multi-layer film having at least the above-mentioned intermediate layer and both surface layers. For example, a surface layer / adhesive layer / intermediate layer / adhesive is preferable. A laminate film of 5 layers or more having layers / surface layers in this order can be mentioned.

. At this time, for example, a reproducing layer may be interposed between the layers.

 Therefore, in the following explanation, the surface layer, the intermediate layer, the adhesive layer, and the reproduction layer, which can be components of the lactic acid-based soft film, will be described in this order, and then the laminated structure, characteristic values, and production of the lactic acid-based soft film will be described. The method will be described.

[0020] <Surface layer>

In this lactic acid-based soft film, the front and back layers are layers that can increase the airtightness when a package is formed by heat sealing or adhesion, and can increase the mechanical strength such as tear strength, puncture strength, and impact strength. It is. In addition, when forming a film by inflation molding or a tubular stretch method, it is possible to give the film a function of improving stability during molding. It can also serve as an antiblocking layer for packaging films. When an additive such as a plasticizer is added to the intermediate layer, it is possible to prevent such a pre-out. Since an antifogging agent, an antistatic agent, a lubricant and the like can be added to the surface layer, various functions can be imparted to the film. Furthermore, a lactic acid polymer Over time of the molecular weight of ((BB——11)) and the amount of molecular weight due to hydrolytic decomposition of milk lactate-based co-copolymerized polymer ((BB——22)) It can be done together with the role of IIJJ, which plays a role in suppressing the decline in the target level. .

 [[00002211]] ((Popolyrioolephine-based polymer polymerization ((AA))))

 As for the polypolyolefin olefin-based polymer composite, the ethylenylene-based polymer composite, the butytilylene-based polymer composite, the polypolypropylene-propylene, the ethylene-propylene-propylene. Pupropylopyrenelene-based polymerized polymers such as co-copolymerized polymers, etc., Polypropylene 44-Memethylicylpepentene Tetenen, Poporiribbuteten, Ethyethylenelene monobutyrate This is where you can list the copolypolymers. . These resin resin fats may be 11 kinds of resin resin oils of the uchichi listed in the above description, or may be left untouched. More than 22 kinds of resin fats can be mixed and mixed resin resin fats. .

 A popolite in which these polypolyolefin olefins are polymerized into a polydisperse-dispersed composite compound such as ethylethylene, propylpropirylene rubber gum, etc. It can be made with Lirio Olefin-based thermo-thermoplastic plastic-plastic elarasto tomoma. .

 [[00002222]] Even in the above description, the role of the surface layer layer, that is, the prevention of bublo rocking of the packaging film Anti-fogging, slipperiness and surface tackiness, and appropriate surface resistance, such as anti-fogging and anti-fogging properties. Molding processing at the time of membrane film, stable qualitative property, and further, lactic acid acid-based mixed mixed resin resin composition composition by hydrolyzed water decomposition solution ( (BB)) When considering the role of the molecular weight, such as the suppression of the time-dependent decrease in the molecular weight, the surface layer It is preferable that the main main component is an ethylenylene-based polymer composite. .

[[00002233]] Examples of the ethylenylene-based polymer composites include low low density poplarie ethyleneylene, linear linear low low density poplarie ethyleneylene, , Linear, ultra-low, low density, low density, and high density, high density, high density, and low density, poplarie ethylene. 11 kinds of ethylenylene-based polymer composites selected from the above, or a mixed mixed resin resin consisting of a combination of more than 22 kinds of these. , Or, or a co-copolymerized polymer having ethethylenelene as the main component, ie, ethethylenelene, propylopirylene, bubutetene 11, Peppententen 11, Hexanesen 11, Hepeptenen 11, Ota Tathen 11, etc. Which carbon number prime number 33 ~~ ;; 1100 aa oleo refhuin, biururol acetate, bupropuropirylene acetic acid biburu etc. Any unsaturated cacacrobo 11 kinds of unsaturated compounds that can be selected from among unsaturated unsaturated compounds such as estellite phosphate, co-conjugate role digene, non-non-co-conjugate role digene, etc. Is a co-copolymerized polymer with more than 22 kinds of kokomo monomers, or a multi-component co-copolymerized polymer, Alternatively, the above-mentioned acetylylene-based polymer copolymer, the above-mentioned co-copolymer copolymer, and the above-mentioned multi-multi-co-polymer copolymer It is possible to combine more than a variety of types and strengths, and here you can list the mixed and mixed resin resin fats. . These are the ethylenylene-based polymer units of the ethyleneylene-based polymer unit.

Even in the middle, low density low-density poplarie ethyleneylene, linear low density low density poplarie ethyleneylene, linear ultra-low density low density poplarin Echichirenren , Ethylene acetate butyl copolymer, ethylene acrylate copolymer, and ethylene-methacrylate copolymer, one kind of ethylene polymer or a mixed resin composed of a combination of two or more of these Is particularly preferred.

 Examples of the acrylic ester of the ethylene acrylic ester copolymer include methyl acrylate and ethyl acrylate. Examples of the methacrylate ester of the ethylene-methacrylic ester copolymer include methyl methacrylate, Mention may be made of methacrylic acid ethyl alcohol and the like.

[0024] Among the above polyolefin polymers (A), when importance is attached to surface properties such as balance of surface tackiness, antifogging properties, and molding processing stability during film formation, the content of butyl acetate is 10-60. mass _^0/0, melt flow rate (hereinafter, may be abbreviated as "MFR". measurement conditions MFR is, 190.C based on JIS K 7210, a load 21. 18N, for the remaining MFR The ethylene-butyl acetate copolymer is particularly preferred in that it is 0.2 to 20 g / 10 min.

 In this ethylene acetate butyl copolymer, if the butyl acetate content is 10% by mass or more, the crystallinity is low! /, So the film does not become hard, the flexibility and elastic recovery are good, and the surface tackiness is also good. It is preferable in terms of easy expression. On the other hand, if it is 60% by mass or less, heat resistance, film strength, etc. can be secured, and even if an antifogging agent is added, bleeding out can be suppressed, and the strength and surface adhesiveness are not too strong. It is preferable in that the unwinding property and appearance can be improved. From such a point of view, it is more preferable that the ethylene acetate butyl copolymer content in the ethylene monoacetate butyl copolymer is 10 to 58% by mass, and more preferably 12 to 56% by mass.

 Also, if the MFR of the ethylene acetate butyl copolymer is 0.2 g / 10 min or more, the extrusion processability is stable, and if it is 20 g / 10 min or less, stable film formation is possible at the time of molding. Thickness unevenness, decrease in mechanical strength, variation, etc. are reduced, which is preferable. From such a viewpoint, the MFR of the ethylene-butyl acetate copolymer is more preferably 0.5 to 18 g / 10 min, more preferably! To 15 g / 10 min.

[0025] On the other hand, when the microwave oven heat resistance that can withstand microwave heating is emphasized, the density is 0.

90—0.9 95 g / cm ³ and MFR of 0.2 to 20 g / 10 min linear low density polyethylene Is particularly preferred.

If the density of the polyolefin polymer (A) is within such a range, the film does not become hard because it has appropriate crystallinity, and the flexibility and elastic recovery are good, and the polyolefin polymer (A ) Has a melting point higher than the actual operating temperature range of the wrap, specifically, the atmospheric temperature when heated in a microwave oven, etc., so even if the food is wrapped with the resulting film and heated in the microwave oven, etc. This is preferable because there is no problem that the film melts and sticks to a container or the like. From this viewpoint, the density (or 0. 90-0 of polyolefin-based polymer (A). Mosquito particularly preferably of is 94 g / cm ^3, among others 0. 91-0. 94g / cm ³ and even more preferable.

 If the MFR of the polyolefin polymer (A) is 0.2 g / 10 min or more, the extrusion processability is stable, and if it is 20 g / 10 min or less, stable film formation at the time of molding becomes possible. This is preferred because it reduces thick spots, lowering of mechanical strength and variations. From such a viewpoint, the MFR of the polyolefin-based polymer (A) is particularly preferably 0.5 to 18 g / 10 min, more preferably 1 to 15 g / 10 min.

 [0026] The method for producing the polyolefin polymer (A) is not particularly limited, and is a known polymerization method using a known olefin polymerization catalyst, such as a multi-layer represented by a Ziegler-Natta type catalyst. Examples include slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method, and bulk polymerization method using radical initiator, using single-site catalyst typified by site catalyst and meta-open catalyst. Can do.

 [0027] <Intermediate layer>

 The intermediate layer of the present lactic acid-based soft film contains, as main components, a lactic acid-based polymer (B-1) and a lactic acid-based copolymer (B-2), in other words, a lactic acid-based polymer (B-1) and The layer contains a lactic acid-based mixed resin composition (B) composed of the lactic acid-based copolymer (B-2) as a main component, and further contains a plasticizer (C) as necessary.

[0028] (Lactic acid polymer (B-1))

The lactic acid polymer (B-1) includes poly (L lactic acid) whose structural unit is L lactic acid, poly (D lactic acid) whose structural unit is D lactic acid, and poly (L lactic acid) whose structural unit is L lactic acid and D lactic acid. (DL lactic acid) or a mixture thereof can be used. From the viewpoint of suppressing the bleed-out of the plasticizer, since the lactic acid polymer has a low crystallinity, it is preferable that the intermediate layer contains a plasticizer and is more crystalline than poly (L lactic acid). It is preferred to use low polylactic acid, such as poly (D lactic acid), poly (DL lactic acid), or mixtures thereof.

 The poly (L lactic acid) or poly (D lactic acid) referred to here is ideally a polymer composed of 100% L lactic acid or D lactic acid. It contains 98% or more of L-lactic acid or D-lactic acid.

[0029] The ratio (molar ratio) of D-lactic acid (D-form) to lactic acid (L-form) in the lactic acid polymer (B-1) is L-form: D-form = 100: 0 to 85:15, or L-form: D-form = 0: 100 to 15: 85, preferably L-form: D-form = 99.5: 0.5-85: 15, or L-form: 0-form = 5/99. 5 ~; 15:85. If the strength is within the range, the heat resistance of the resulting film will not be impaired.

 In this case as well, from the viewpoint of suppressing bleed-out of the plasticizer, it is preferable that the lactic acid polymer has low crystallinity! /, And preferably L-form: D-form = 50: 50-94 : 6

 In addition, you may blend the lactic acid-type polymer from which the copolymerization ratio of L body and D body differs. In that case, the average value of the copolymerization ratio of the L-form and D-form of a plurality of lactic acid polymers should be within the above range. For example, blending poly (L lactic acid) or poly (D lactic acid) and poly (DL lactic acid) can balance the difficulty of bleeding and the development of heat resistance.

Yes

 [0030] As a polymerization method of the lactic acid-based polymer, a condensation polymerization method, a ring-opening polymerization method, and other known polymerization methods can be employed.

 For example, in the condensation polymerization method, L-lactic acid or D-lactic acid, or a mixture thereof can be directly subjected to dehydration condensation polymerization to obtain a lactic acid polymer having an arbitrary composition.

 In the ring-opening polymerization method (lactide method), lactide, which is a cyclic dimer of lactic acid, has an arbitrary composition and crystallinity using an appropriate catalyst while using a polymerization regulator or the like as necessary. A lactic acid polymer can be obtained.

Lactide includes L-lactide, which is a dimer of L-lactic acid, D-latatid, which is a dimer of D-lactic acid, or DL lactide consisting of L-lactic acid and D-lactic acid. The ability to obtain a lactic acid polymer having an arbitrary composition and an arbitrary crystallinity by mixing and polymerizing at the same time is obtained.

 [0031] The lactic acid-based polymer may contain other hydroxycarboxylic acid as a small amount of a copolymer component, or may contain a small amount of a chain extender residue! / ,.

 [0032] The lactic acid polymer preferably has a weight average molecular weight in the range of 50,000 to 400,000, more preferably in the range of 100,000 to 250,000. Practical properties such as mechanical properties and heat resistance can be secured if the weight average molecular weight of the lactic acid polymer is 50,000 or more, and if it is 400,000 or less, the melt viscosity is too high and the molding processability may be inferior. Absent.

 [0033] As the lactic acid polymer (B-1), a commercially available lactic acid polymer can also be used. For example, the product name “Lacia” series (made by Mitsui Chemicals), the product name “Nature Works j series” (made by NatureWorks), the product name “U'z series” (made by Toyota Motor Corporation), etc. The power S

 [0034] (Lactic acid-based copolymer (B-2))

 The lactic acid copolymer (B-2) is a resin obtained by copolymerizing a lactic acid polymer. Among them, the one that forms a completely compatible polymer blend with the lactic acid polymer (B-1) is preferred! In other words, a polymer blend composition obtained by mixing a lactic acid copolymer (B-2) and a lactic acid polymer (B-1) is used for differential scanning calorimetry! Preference is given to lactic acid copolymers (B-2) with a single glass transition temperature measured at a heating rate of 10 ° C / min! /.

[0035] Here, the single glass transition temperature of the mixed resin composition means that the polymer blend composition is subjected to glass transition using a differential scanning calorimeter at a heating rate of 10 ° C / min in accordance with JISK7121. This means that only one peak indicating the glass transition temperature appears when the temperature is measured. From another viewpoint, when the polymer blend composition was measured by dynamic viscoelasticity measurement (dynamic viscoelasticity measurement of JISK-7198A method) at a strain of 0.1% and a vibration frequency of 10 Hz, the loss It means that there is one local maximum of tangent (tan δ). The single glass transition temperature (or maximum loss tangent) of the polymer blend composition means that the lactic acid polymer (Β—1) and the lactic acid copolymer (Β—2) are nanometers. This means that they are in a compatible state on the order (molecular level), and a level of transparency that cannot be obtained with an incompatible polymer blend can be obtained. [0036] As a preferred example of the lactic acid copolymer (B-2), for example, a copolymer of the above lactic acid polymer and a diol / dicarboxylic acid can be mentioned.

 [0037] The lactic acid polymer constituting the copolymer of the lactic acid polymer and the diol 'dicarboxylic acid may be any of L lactic acid, D lactic acid, and DL lactic acid. From the viewpoint of forming a completely compatible polymer blend with (B-1), those having the same structure as the structural unit of the lactic acid polymer (B-1) are particularly preferred.

 [0038] On the other hand, the diol component in the diol'dicarboxylic acid is not particularly limited. For example, ethylene glycol, 1,3-propanediol, 1,4 butanediol, 1,5-pentanenone, 1,6 Hexanionole, 1,7 Peptannore, 1,8—One-year-old Kutanji-no-one, 1,9-Nonanji-old-nore, 1,10 Decandi-old-nore, 1,11 Undecanediol, 1,12-Dodecanediol, etc. Chain diol, propylene danorole, 1,2-propyl, tangiore, 1,3-propyl, tangiore, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,3-pentane Diol, 2,4 pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, etc.岐鎖 like diols, polyethylene glycol, polypropylene glycol, polybutylene da recall, it can be mentioned polytetramethylene polyols such as glycol, among others polypropylene glycol is preferred

Yes

[0039] The dicarboxylic acid component in the diol.dicarboxylic acid is not particularly limited. For example, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, maleic acid , Fumaric acid, citraconic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid and other linear dicarboxylic acids, methyl succinic acid, dimethyl succinic acid, ethyl succinic acid, 2-methyl daltaric acid, 2-ethyl taltalic acid, 3-methyl daltaric acid, Branched dicarboxylic acids such as 3 ethyldaltaric acid, 2 methyladipic acid, 2 ethyladipic acid, 3-methyladipic acid, 3-ethyladipic acid, methyldaltaric acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, Naphthalene dicarboxylic acid, phthalic anhydride, vinyl Phenol A, can be exemplified aromatic dicarboxylic acids such as Bifuenoru, inter alia succinic acid is preferred. Therefore, the copolymer of the lactic acid polymer constituting the lactic acid copolymer (B-2) and the diol / dicarboxylic acid is a copolymer of lactic acid polymer, (poly) propylene glycol and succinic acid. Is the most preferred example.

 [0040] In addition, among the above-mentioned types of lactic acid polymers and diol dicarboxylic acid copolymers, a strain of 0.1% and a vibration frequency of 10H are obtained from the viewpoint of softening the lactic acid polymer. It is preferable to select and use a copolymer having a maximum value of loss tangent (tan δ) measured by dynamic viscoelasticity measurement (dynamic viscoelasticity measurement by JISK-7198A method) at z. This point will be described in detail below.

 Here, a copolymer having two maximum values of loss tangent is referred to as “称 type”, and a copolymer having one maximum value of loss tangent is referred to as “Β type”. . Blending a copolymer with two loss tangent maxima (Α type) cannot soften the lactic acid polymer (Β—1) due to a decrease in the glass transition temperature, but it has a maximum loss tangent. By blending a copolymer with a single value (1 type), the lactic acid polymer (Β-1) can be softened by lowering the glass transition temperature. From this, it can be said that the component (B) is preferably a copolymer (B type) having one maximum value of loss tangent (ta η δ).

 [0042] Incidentally, examples of the structure of a copolymer of a lactic acid-based polymer and a diol dicarboxylic acid include a random copolymer, a block copolymer, and a graft copolymer. In general, when the copolymer structure is a block copolymer, it becomes a type (A type) in which there are two maximum values of the loss tangent measured under the above conditions, and the copolymer structure Is a random copolymer, it has a type (B type) in which there is one local maximum of loss tangent measured under the same conditions, so the structure of lactic acid copolymer (B-2) is A random copolymer is preferred.

[0043] In the copolymer of lactic acid-based polymer and diol'dicarboxylic acid, the content ratio of lactic acid-based polymer to diol'dicarboxylic acid is the storage elastic modulus at 20 ° C, peak temperature of loss tangent and It is preferable to adjust so that the loss tangent value falls within a desired range. As a guideline, the mass ratio between the lactic acid polymer and the diol dicarboxylic acid is 10:90 to 70:30, particularly 30:70 to 70:30, and particularly 40:60 to 60:40. It is preferable to adjust to [0044] The copolymer of lactic acid-based polymer and diol'dicarboxylic acid can be adjusted to a predetermined molecular weight using an isocyanate compound or a carboxylic acid anhydride. However, in terms of processability and durability, the weight average molecular weight of the copolymer of lactic acid polymer and diol dicarboxylic acid is preferably in the range of 50,000 to 300,000, and in the range of 100,000 to 250,000. More preferred.

 [0045] The method for producing a copolymer of a lactic acid-based polymer and a diol'dicarboxylic acid is not particularly limited! /, But a polyester or polyether polyol having a structure in which a diol and a dicarboxylic acid are dehydrated and condensed. From a lactide and a ring-opening polymerization or a transesterification reaction, or a polyester or polyether polyol having a structure obtained by dehydration condensation of a diol and a dicarboxylic acid, and dehydration of a lactic acid polymer and a deglycolization condensation or an ester exchange reaction. And the like.

 [0046] A commercially available lactic acid polymer and a copolymer of diol'dicarboxylic acid can also be used. Specifically, it is possible to name the product “Bramate PD-350” (manufactured by Dainippon Ink & Chemicals, Inc.) with the power S.

 [0047] As described above, the lactic acid-based mixed resin composition (B) comprising the lactic acid-based polymer (B-1) and the lactic acid-based copolymer (B-2) has a polymer blend (mixed) of the two. Resin compositions) that are completely compatible, that is, those having a single glass transition temperature measured at a heating rate of 10 ° C / min by differential scanning calorimetry, are preferred. Those having a temperature range of C to 30 ° C, particularly 20 ° C to 30 ° C are more preferable. When the glass transition temperature is within the range of 0 ° C to 30 ° C, the film will not grow too hard under the actual usage environment temperature, and will be properly stretched. Therefore, it is particularly suitable as a household wrap film.

 [0048] It should be noted that other lactic acid copolymers that form a completely compatible polymer blend with the lactic acid polymer (B-1) can also be used. For example, a copolymer of lactic acid polymer and polyethylene glycol can be mentioned as a preferred example.

[0049] The total molecular weight of the lactic acid polymer (B-1) and the lactic acid copolymer (B-2) is preferably 100,000 or more. For this purpose, it is preferable to increase the overall molecular weight by blending a high molecular weight lactic acid polymer (B-1). The film can be easily formed.

 [0050] The mixing ratio of the lactic acid polymer (B-1) and the lactic acid copolymer (B-2) is as follows: the lactic acid polymer (B-1) and the lactic acid copolymer (B-2). The ratio of the lactic acid-based polymer (B-1) in the total is preferably 50 to 80% by mass, and the ratio of the lactic acid-based copolymer (B-2) is preferably 50 to 20% by mass.

 In this lactic acid-based soft film, increasing the proportion of the lactic acid-based copolymer (B-2) can provide flexibility without impairing the transparency, but the lactic acid-based copolymer (B— When the proportion of 2) increases, the weight average molecular weight may decrease to 100,000 or less, and it is considered that practical physical properties, for example, mechanical properties when left in a humid state for a long time, are not expressed. Further, when the proportion of the lactic acid copolymer (B-2) is increased, the melt viscosity is lowered and the molding processability is lowered. In view of these points, the proportion of the lactic acid copolymer (B-2) in the total of the lactic acid polymer (B-1) and the lactic acid copolymer (B-2) is limited to 50% by mass. It is necessary to make it 40% by mass or less. On the other hand, since the ratio of the lactic acid copolymer (B-2) is small! /, The plasticizing effect is reduced and the flexibility is poor! /, Since the film becomes a film, the lactic acid polymer (B — The proportion of lactic acid copolymer (B-2) in the total of 1) and lactic acid copolymer (B-2) must be 20% by mass, and should be 30% by mass or more. Is more preferable.

 [0051] (Plasticizer (C))

Even if the intermediate layer of the lactic acid-based soft film is composed mainly of the lactic acid-based mixed resin composition (B), the transparency is impaired if the proportion of the lactic acid-based copolymer (B-2) is increased. Without this, the film can be made flexible. However, when the proportion of the lactic acid copolymer (B-2) increases, the practical physical properties, for example, the mechanical properties when left in a humid state for a long time are lowered, or the melt viscosity is lowered and the molding process is reduced. Therefore, it is preferable to add a plasticizer (C) if necessary. At this time, the lactic acid copolymer (B-2) and the plasticizer (C) are in a relationship that complements each other's problems, and the machine when placed in a humid state for a long time by blending the plasticizer (C). It is possible to prevent deterioration of mechanical properties and maintain melt viscosity, but to prevent plasticizer bleed out and change in mechanical properties during long-term storage by blending lactic acid copolymer (B-2). . [0052] The plasticizer (C) has a function of lowering the glass transition temperature (Tg) of the resin and softening it. S. As a plasticizer for the lactic acid-based soft film, compatibility and biodegradability are possible. In view of the above, the following (a) and (f) are particularly preferred among those which are preferably one or a combination of two or more selected from the compounds shown in the following (a) to (i).

 Regardless of the molecular weight of the plasticizer, the lactic acid-based soft film composition is characterized by the ability to suppress changes in mechanical properties during long-term storage.

 [0053] (a) H C (OH) _n (OOCCH) (where 0 <n≤ 3)

 6 3 3 3 n

 This is glycerin monoacetate, diacetate or triacetate, and a mixture of these may be used! /, But n is close to 3! /, More preferred! /.

 (b) Glycerin alkylate (The alkyl group may have 2 to 20 carbon atoms and a hydroxyl group residue)

 Examples include glycerin tripropionate and glycerin tributyrate.

(c) Ethylene glycol alkylate (the alkyl group has 1 to 20 carbon atoms and may have a hydroxyl group residue).

 For example, ethylene glycol diacetate can be used.

 (d) Polyethylene glycol alkylate having an ethylene repeating unit of 5 or less (the alkyl group has carbon atoms;! to 12 and may have a hydroxyl group residue).

 For example, mention may be made of diethylene glycol monoacetate, diethylene glycol diacetate and the like with a force S.

 (e) Aliphatic monocarboxylic acid alkyl ester (the alkyl group has 1 to 20 carbon atoms)

 Examples thereof include butyl stearate.

 (f) Aliphatic dicarboxylic acid alkyl ester

 The alkyl group may have 1 to 20 carbon atoms and a carboxyl group residue. Among them, the number average molecular weight of 100 to 2000 is preferable. Specific examples include di (2-ethynolehexinole) adipate and di (2-ethynylhexyl) azelate.

 (g) Aliphatic tricarboxylic acid alkyl ester

The alkyl group may have 1 to 20 carbon atoms and a carboxyl group residue. For example, fly An acid trimethyl ester etc. can be mentioned.

 (h) Natural fats and oils and their derivatives

 For example, soybean oil, epoxidized soybean oil, castor oil, tung oil, rapeseed oil and the like can be mentioned.

(i) Polyalkylene ether

 Examples thereof include polyethylene glycol, polypropylene glycol, polybutylene glycol and polytetramethylene glycol.

 [0054] Among these, considering food packaging applications, food additives such as glycerin fatty acid esters and polybutenes, or epoxidized vegetable oils, acetylated citrate fatty acid esters, etc. are recognized. Additives such as indirect food additives are more preferred. These may be used alone or in combination of two or more.

 Among these, it is preferable to select a glycerin fatty acid ester in view of adhesion of the wrap film, drawability, bleed resistance to the wrap film surface, and the like.

 [0055] The type of glycerin fatty acid ester is not particularly limited, and examples thereof include monoglyceride, triglycerin, tetraglycerin, and other polyglycerin fatty acid esters, in addition to monodallylide, diglyceride, tridallylide, and acetylated monodallylide. The ability to raise S. Among these, acetylated monodalides having a molecular structure represented by the following chemical formula (1) are particularly preferred from the viewpoint of good compatibility with lactic acid polymers and high plasticizing ability.

 [0056] [Chemical 1]

CH ₂ —〇1 CO— R ¹

 I

CH-O-R ²

 I

CH ₂ -O-R ³

In the above chemical formula (1), R ¹ represents an alkyl group, R ² and R ³ each represent a acetyl group or hydrogen. The carbon number of these alkyl groups is appropriately selected so as to achieve the purpose of improving adhesion and flexibility without any particular limitation, and is generally preferably 6-20. [0058] In order to obtain good compatibility with the lactic acid-based polymer (B-1), the molecular weight of the glycerin fatty acid ester is particularly preferably 2000 or less, more preferably 1500 or less.

 [0059] The compounding amount of the plasticizer (C) is 1 to 15 parts by mass with respect to 100 parts by mass of the total of the lactic acid polymer (B-1) and the lactic acid copolymer (B-2). Is preferred. With respect to the upper limit, it is more preferably 10 parts by mass or less, particularly 9 parts by mass or less. Regarding the lower limit, it is more preferably 3 parts by mass or more, and particularly preferably 5 parts by mass or more.

 If the proportion of the plasticizer (C) increases with respect to the total of the lactic acid-based polymer (B-1) and the lactic acid-based copolymer (B-2), flexibility can be imparted without impairing transparency. Force that can be generated Over time, the plasticizer migrates to the surface and causes problems such as bleeding out, where the surface becomes sticky. On the other hand, if the amount of the plasticizer is small, the film becomes poor in flexibility, and it becomes necessary to increase the ratio of the lactic acid copolymer (B-2). Therefore, the amount of plasticizer (C) is preferably within the above range! /.

 [0060] (Other ingredients)

 The intermediate layer of the present lactic acid-based soft film can also contain a polyolefin polymer (E).

 [0061] The polyolefin polymer (E) may be the same polyolefin polymer as the polyolefin polymer (A) constituting the surface layer or a different polyolefin polymer, but is preferably Are preferably the same polyolefin polymer. If the polyolefin polymer (E) and the polyolefin polymer (A) constituting the surface layer are the same polyolefin polymer, the adhesion between the intermediate layer and the surface layer can be improved, and the entire film can be improved. In addition to improving the mechanical properties, for example, trimming loss that occurs when both ends of a formed film are cut and trimmed can also be added as a constituent material for the intermediate layer, eliminating waste of materials. The material cost can be reduced.

[0062] As the most preferred polyolefin polymer (E), an ethylene acetate butyl copolymer having a butyl acetate content of 10 to 60% by mass can be mentioned. This ethylene acetate butyl copolymer can be suitably used as a polyolefin polymer (A), which is the main component of the surface layer, and is transparent when a recycled resin generated from trimming loss is added. It can be stably obtained as an industrial material that has no practical problems including brightness, mechanical properties and material cost.

 [0063] The blending ratio of the polyolefin polymer (E) is the ratio to the total mass of the lactic acid polymer (B-1) and the lactic acid copolymer (B-2) in the intermediate layer: (Β-1) + (Β-2): (E) = 99: l to 50:50, particularly 95: 5 to 50:50, and particularly preferably 90:10 to 55:45. By setting the force within the range, it is preferable because the elastic modulus can be maintained and the “waist” that is one of the wrap characteristics can be maintained.

 [0064] Further, the intermediate layer of the lactic acid-based soft film has a heat stabilizer, an antioxidant, a UV absorber, an anti-blocking agent, a light stabilizer, a nucleating agent, an additive, as long as the effects of the main component are not impaired. Additives such as moisture deterrents and deodorants can be formulated.

 For example, in order to maintain the practical characteristics of the present lactic acid-based soft film, a lactic acid-based mixed resin composition (B) consisting of a lactic acid-based polymer (B-1) and a lactic acid-based copolymer (B-2) (B) 100 mass The weight average molecular weight can be increased by adding 0.5 to 3 parts by mass, more preferably 0.5 to 1 part by mass of the calpositimide compound with respect to parts. Below this range, the effect of increasing the weight average molecular weight is often small, and when exceeding this range, fish eyes and gels may be formed during film formation, which is not preferable.

 [0065] <Adhesive layer>

 Next, components of the adhesive layer will be described.

[0066] The adhesive layer contains, as a main component, a copolymer of a soft aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated derivative of these copolymers (F-1), and a butyl acetate content of 30 to 80% by mass of ethylene acetate butyl copolymer (F-2), modified polyolefin resin (F-3), lactic acid polymer, polymer block mainly composed of acrylate units, and methacrylate units One of these is acceptable as long as it contains any strength of lactic acid 'acrylic mixed resin (F-4), which is a mixed resin with an acrylic block copolymer having a polymer block as a main component. It may be a mixture of two or more (hereinafter these are collectively referred to as “adhesive layer component F”). It can also be used in combination with other thermoplastic resins. The type and mixing ratio of the resin to be mixed constitutes both the surface layer and the intermediate layer. It can be determined appropriately according to the resin to be used.

 [0067] (Adhesive layer component (F-1))

 In the adhesive layer component (F-1), styrene is preferably used as the soft aromatic hydrocarbon, and styrene analogs such as α-methylol styrene can also be used.

 As the conjugation hydrocarbon, 1,3-butadiene, 1,2-isoprene, 1,4 isoprene, 1,3-pentagen, etc. are used, and these may be hydrogenated derivatives. These may be used alone or in admixture of two or more.

 [0068] The content of the soft aromatic hydrocarbon in the copolymer of the soft aromatic hydrocarbon and the conjugated diene hydrocarbon or its hydrogenated derivative (F-1) is determined as follows. Based on the mass of (100%), it is preferably 5 to 40% by mass, more preferably 7 to 35% by mass, and still more preferably 10 to 30% by mass. If the content of the soft aromatic hydrocarbon is 5% by mass or more, good compatibility can be obtained when the recycled film is regenerated and added to any layer, and the clouding of the film can be suppressed. . On the other hand, if the content of aromatic hydrocarbons is 40% by mass or less, when stress is applied to the film without reducing flexibility, the buffering action against stress generated between the surface layer and the intermediate layer is prevented. Since it works, delamination can be suppressed.

 [0069] Copolymers of soft aromatic hydrocarbons and conjugated diene hydrocarbons or their hydrogenated derivatives (F-1) include styrene monoconjugate random copolymers and styrene monoconjugate digens. A hydrogenated derivative of a random copolymer can be preferably used. These copolymers can be used alone or in admixture of two or more. Furthermore, it can also be used by mixing with one or more other thermoplastic resins.

 [0070] As a copolymer of a soft aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated derivative (F-1) thereof, a copolymer obtained by introducing a polar group can also be selected.

 The polar groups to be introduced include acid anhydride groups, carboxylic acid groups, carboxylic acid ester groups, strong rubonic acid chloride groups, carboxylic acid amide groups, carboxylic acid groups, sulfonic acid groups, sulfonic acid ester groups, and sulfonic acid chlorides. Groups, sulfonic acid amide groups, sulfonic acid groups, epoxy groups, amino groups, imide groups, oxazoline groups, hydroxyl groups and the like.

Copolymers of styrenic compounds and conjugate gens introduced with polar groups or their hydrogenated calo Representative derivatives include maleic anhydride-modified SEBS, maleic anhydride-modified SEPS, epoxy-modified SEBS, and epoxy-modified SEPS.

 These copolymers can be used alone or in admixture of two or more.

 [0071] A copolymer of a soft aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated derivative thereof (F-1) exhibits both adhesion between both surface layers and an intermediate layer and extrusion stability. In the case of emphasis, it is preferable to select a copolymer with a styrene monoconjugate hydrocarbon having an MFR (JISK7210, 190.C, load 21.18N) force of 0.8-30 g / 10 min. Extrusion processability is stable when the MFR of the conjugated-gen hydrocarbon is 0.8 g / 10 min or more, and stable film formation at the time of molding is possible if it is 3 Og / 10 min or less. In view of this, it is preferable that the MFR is from !! to 20 g / 10 min.

 [0072] (Adhesive layer component (F-2))

 In the ethylene acetate butyl copolymer (F-2), the butyl acetate content is preferably 30 to 80%. If the butyl acetate content is 30% by mass or more, the crystallinity is low, so the elastic modulus at normal temperature is low, self-adhesiveness is easily developed, and the refractive index of the film is a component constituting the intermediate layer. Since transparency improves by approaching, it is preferable. On the other hand, if it is 80% by mass or less, blocking of raw materials does not occur, and there is no problem in handling, which is preferable. These powers are preferably 30-80% by mass of acetic acid but also more preferably 45-60% by mass, more preferably 40-70% by mass.

[0073] When ethylene-butyl acetate copolymer is used as the polyolefin-based polymer (A), which is the main component of both surface layers, the butyl acetate content of the ethylene acetate butyl copolymer in both surface layers Rather, it is preferable to increase the butyl acetate content of the ethylene acetate butyl copolymer of the adhesive layer. For example, the ethylene acetate butyl copolymer content of both surface layers is 10% by mass or more and less than 30% by mass, and the ethylene acetate butyl copolymer content of the adhesive layer is 30 to 80% by mass. do it. By doing this, while maintaining the film properties such as heat resistance, film strength, bleed-out suppression, film unwinding property, and appearance, the adhesiveness of each layer (delamination during small rewinding) and Transparency can be improved, and a design that is particularly useful as a small roll film is possible. It becomes ability.

 [0074] In the case where importance is attached to both the adhesion between the surface layer and the intermediate layer and the extrusion stability, an ethylene acetate butyl copolymer (F-2) having a butyl acetate content of 30 to 80% by mass is used. MFR (JISK7210, 190.C, load 21.18N) force 8-30g / 10min ethylene-acetate copolymer is preferred, If the MFR of the ethylene acetate butyl copolymer is 0.8 g / 10 min or more, the extrusion processability is stable, and if it is 30 g / 10 min or less, stable film formation is possible at the time of molding. This is preferable because the decrease in strength, variation, and the like are reduced. Again, this MFR is preferably 1-20 g / 10 min.

 [0075] Such an adhesive layer component (F-2) can also be used by mixing with other thermoplastic resins such as other polyolefin-based copolymers. In that case, the kind of resin to be mixed, the mixing ratio, and the like can be appropriately determined according to the resins constituting both the surface layer and the intermediate layer.

 [0076] (Adhesive layer component (F-3))

 The modified polyolefin resin refers to a resin whose main component is a polyolefin modified with a modified monomer such as an unsaturated carboxylic acid or its anhydride, or a silane coupling agent.

 In the modified polyolefin resin (F-3), the unsaturated carboxylic acid or its anhydride includes acrylic acid, methacrylic acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, itaconic anhydride Examples include esters of acids or monoepoxy compounds of these derivatives and the above-mentioned acids, reaction products of polymers having groups capable of reacting with these acids in the molecule and acids, or metal salts thereof. These can be used alone, or two or more of these can be mixed and used.

 As the unsaturated carboxylic acid or its anhydride, maleic anhydride is more preferable among the above.

[0078] Examples of the silane coupling agent include butyltriethoxysilane and methacryloyloxytrime, and these can be used alone, or two or more of these can be used. It is easy to mix and use.

[0079] In order to produce a modified polyolefin resin, for example, these modified monomers can be copolymerized in the stage of polymerizing in advance, or these modified monomers can be grafted onto a polymer once polymerized. It can also be polymerized. Of these, graft-modified ones are particularly suitable.

In the modification, these modifying monomers can be used alone or in combination. Content of the modified monomer 0.5; is suitably from to 5 mass ^_0/0!.

[0080] Among the above modified polyolefin resins, when the extrusion stability is given the highest priority, at least one ethylene resin selected from low density polyethylene, linear low density polyethylene, and linear ultra low density polyethylene is used. It is preferred to select a graft copolymer with maleic anhydride.

[0081] (Adhesive layer component (F-4))

 Lactic acid 'acrylic mixed resin (F-4) is an acrylic block copolymer having a lactic acid polymer, a polymer block mainly composed of acrylate units, and a polymer block mainly composed of methacrylate units. It is a mixed resin with (G).

[0082] The lactic acid polymer in the lactic acid 'acrylic mixed resin (F-4) can be selected from the same type as the lactic acid polymer (B-1) in the intermediate layer.

 The lactic acid polymer used in the adhesive layer and the lactic acid polymer in the intermediate layer may be the same or different, and may be optimal depending on the suitability of each layer. Choose a lactic acid polymer with a composition! /.

 The lactic acid-based polymer used for the adhesive layer may include other copolymers (components) other than lactic acid, either L, D, or DL (racemic).

Other copolymer components include ethylene glycol, propylene glycol, butanediol, decanediol, 1,4-cyclohexanthyldaricol, neopentylglycol monoole, glycerin, pentaerythritol, bisphenolore A, polyethylene glycol Glycol compounds such as Nole, polypropylene glycol and polytetramethylene glycol, oxalic acid, adipic acid, malonic acid, dartaric acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, cyclohexane Dicarboxylic acid, dodecanedione Acid, naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracenedicanolevonic acid, 4,4-diphenyl ether dicarboxylic acid, 5-sodium sulfoisophthalanolic acid, 5-tetrabutylphosphonium isophthalic acid Hydroxycarboxylic acids such as dicarboxylic acid, glycolic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid, etc., and force prolatatatone, valerolataton, propiolataton, undecalactone, 1,5-oxepane 2-Lattones such as ON can be listed.

 [0083] On the other hand, the acrylic block copolymer (G) has at least one polymer block (gl) mainly composed of acrylate units and at least 1 mainly composed of methacrylate units. A block copolymer having a polymer block (g2).

The content of the acrylate unit in the polymer block (gl) and the content of the methacrylic ester unit in the polymer block ( _g 2) are not particularly limited as long as they are the main components. Are each in the range of 60 to 100% by mass, preferably S, and more preferably in the range of 80 to 100% by mass.

 [0084] The block (gl) mainly composed of an acrylate ester unit is a polymer block mainly composed of an acrylate ester unit, and examples of the acrylate ester for forming the polymer block include: , Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, N-hexyl acrylate, cyclohexyl acrylate, 2-ethyl hexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoloxyl acrylate, acrylic acid 2- Hydrochetyl, Acry This the force S include one or more combinations of such acid 2 Metokishechiru. However, it is not limited to such an example.

[0085] The polymer block (g2) mainly composed of the methacrylic acid ester unit is a polymer block mainly composed of a methacrylic acid ester unit, and is used as a methacrylic acid ester for forming the polymer block. For example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, Isobutyl tacrylate, sec butyl methacrylate, tert butyl methacrylate, isoamyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, methacrylic acid Examples thereof include one or a combination of two or more of dodecyl, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoloxyl methacrylate, 2-hydroxyethyl methacrylate, and 2-methoxyethyl methacrylate. However, it is not limited to such examples.

 [0086] The acrylic block copolymer (G) includes a polymer block (gl) mainly composed of acrylate units and a polymer block (g2) mainly composed of methacrylic ester units. Among them, a triblock copolymer in which the polymer block (g2) is bonded to both ends of the polymer block (gl) is preferable in terms of improving heat resistance and the like.

 [0087] It is also preferable to have a polymer block (g 3) derived from monomer power other than the acrylate monomer and methacrylate monomer in a block different from these blocks (gl and g2). .

The form of the bond between the polymer block ( _g 3) and the polymer block (gl) or the polymer block (g2) is not particularly limited. For example, (g2)-{(gl) (g2)} Examples include the n- (g3) structure (n is a natural number) and the (g3)-(g2)-{(gl)-(g2)} n- (g3) structure. Examples of monomers constituting the polymer block ( _g 3) include olefins such as ethylene, propylene, 1-butene, isobutylene and 1-octene, conjugated compounds such as 1,3-butadiene, isoprene and myrcene, styrene, α- Aromatic butyl compounds such as methyl styrene, ρ methyl styrene, m methyl styrene, butyl acetate, butyl pyridine, phthalonitrile, methacrylonitrile, vinyl ketone, butyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε —Power S Raise power prolatathon, valero rataton, etc.

[0088] In the lactic acid 'acrylic mixed resin (F-4), the mass ratio of the lactic acid polymer (U and the acrylic block copolymer (G) is (U: (G) = 10: 90 to 70: More preferably, it is 30 (L): (G) = 20: 80 to 50:50 (In the sum of U and (G), the amount of (G) is 30% by mass or more. If present, the function as an adhesive layer can be fully expressed, Moreover, if it is 90 mass% or less, since affinity with a lactic acid-type polymer (B-1) and an affinity with an intermediate | middle layer become favorable, it is preferable.

[0089] The melt flow rate (JIS K7210, 190 ° C, load 2 1.18N) (hereinafter also referred to as “MFR”) of lactic acid / acrylic mixed resin (F-4) is 0.2 g / 10 min or more. If so, the extrudability is stable, but when used as an adhesive layer, it is preferable that the difference in melt viscosity between the front and back layers or the intermediate layer is small. From this point of view, the MFR of the lactic acid / acrylic mixed resin (F-4) is preferably in the range of 5 to 50 g / 10 min, particularly preferably in the range of 10 to 40 g / 10 min.

 [0090] As long as the effect of the lactic acid / acrylic mixed resin (F-4) is not impaired, in addition to the lactic acid-based polymer and the acrylic block copolymer, other polymers and additives may be added as necessary. An additive may be contained.

 Examples of other polymers that can be blended include polyacrylic rubber, polybutene rubber, polyisobutylene rubber, synthetic rubber such as EPR and EPDM. Examples of additives include mineral oil softeners such as paraffinic oils and naphthenic oils for improving fluidity during molding; improvement in heat resistance, weather resistance, etc. Desired calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, magnesium carbonate and other inorganic fillers; glass fiber for reinforcement, inorganic fiber or organic fiber such as carbon fiber; thermal stabilizer An antioxidant; a light stabilizer; an adhesive; a tackifier; a plasticizer; an antistatic agent; and a foaming agent. Among these additives, in order to further improve heat resistance and weather resistance, it is practically preferable to add heat stability, an antioxidant, and the like.

 [0091] The method for preparing the lactic acid 'acrylic mixed resin (F-4) is not particularly limited. For example, a lactic acid polymer and an acrylic block copolymer may be mixed together with the other polymers and additives described above as necessary. For example, the mixing operation is performed by using a known mixing or kneading apparatus such as a kneader ruder, an extruder, a mixing roll, a Banbury mixer, etc.

The temperature at the time of mixing or kneading should be appropriately adjusted according to the melting temperature of the lactic acid polymer or acrylic block copolymer. Usually, the temperature is in the range of 110 ° C to 300 ° C. To mix.

[0092] (Thickness of adhesive layer)

 The thickness of the adhesive layer is preferably 0 · 3 111 to 5 111 due to its function. If the thickness of the adhesive layer is within such a range, the adhesiveness between both surface layers and the intermediate layer can be expressed, and film forming stability can be obtained during film forming, which is preferable. When it is desired to further secure the thickness ratio of the intermediate layer, it is more preferably 0.5 111 to 3 111.

[0093] <Surface layer, adhesive layer, intermediate layer>

 Various additives such as the following are appropriately added to the surface layer, adhesive layer, and / or intermediate layer of the packaging film in order to impart performance such as antifogging property, antistatic property, slipperiness, and tackiness. Combine with force S.

 For example, an aliphatic alcohol fatty acid ester which is a compound of an aliphatic alcohol having a carbon number of !! to 12, preferably 1 to 6, and a fatty acid having a carbon number of 10 to 22, preferably 12 to 18; Specifically, monoglycerin oleate, polyglycerin oleate, polyglycerin polyricinoleate, glycerin triricinoleate, glycerin acetinorelicinolate, polyglyceryl stearate, polyglyceryl laurate, methyl acetyl tyrosylate, Ethylacetyl recylate, Butinorea cetinorelicylate, Propylene glycolololeate, Propyleneglycolanolate laurate, Pentaerythritololate, Polyethyleneglycolololeate, Polypropylene glycololate, Sorbitanoleate, Sorbitan laurate, polyethylene At least one compound selected from glycol sorbitanolate, polyethylene glycol sorbitan laurate, and the like, and polyalkylene ether polyols, specifically polyethylene glycol, polypropylene glycol, and the like, and also a norafine oil. The seeds can be added in an amount of 0.;! To 12 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the resin component constituting each type.

[0094] <Reproduction layer>

 In addition to the surface layer, intermediate layer, and adhesive layer, this packaging film contains a recycled layer, that is, a polyolefin polymer (A), a lactic acid mixed resin composition (B), and an adhesive layer component (F). A regenerative layer can be provided.

This reproduction layer is generated, for example, when both ends of a formed film are cut and trimmed. Trimming loss can be used, material waste is eliminated, and material costs can be reduced.

 [0095] The reproduction layer can be provided between the surface layer and the adhesive layer, or between the intermediate layer and the adhesive layer.

 For example, two surface layers, intermediate layers, or adhesive layers are formed, and trimming loss at both ends of the film is added to one of the layers to adhere between the surface layer and the adhesive layer, or to the intermediate layer. A reproduction layer can be provided between the layers. In this case, in addition to the thickness ratio and composition ratio of each layer, the layer force to which trimming loss is added is determined depending on whether the surface layer, intermediate layer, or adhesive layer is the surface layer, intermediate layer, or adhesive layer. Adjust the mixing ratio of the components with force S.

 [0096] <Laminated structure>

 This lactic acid-based soft film is a laminated film with three layers of both the surface layer and the intermediate layer, and other layers (hereinafter referred to as “P layer”) as necessary, such as improvement of mechanical properties and interlayer adhesion. Can be abbreviated as appropriate). For example, a layer having the same composition as the surface layer (hereinafter sometimes abbreviated as “S layer”) may be interposed as an intermediate layer in addition to both surface layers. Layer composed of composition (hereinafter, abbreviated as “M layer” is S) 1S Even if two or more layers are interposed between both surface layers, there is no force. Specifically, a three-layer configuration consisting of (S layer) / (M layer) / (S layer), a four-layer configuration consisting of (S layer) / (P layer) / (M layer) / (S layer), (S layer) / (P layer) / (M layer) / (P layer) / (S layer), (S layer) / (M layer) / (P layer) / (M layer) / (S layer), etc. An example of this is a five-layer structure that also has power. In this case, the resin composition and thickness ratio of each layer may be the same or different.

 [0097] An adhesive layer may be provided between the intermediate layer and the surface layer. In addition, a reproducing layer can be provided between the surface layer and the adhesive layer, or between the intermediate layer and the adhesive layer.

For example, a layer having the same composition as the surface layer may be interposed in addition to both surface layers, and two or more layers may be interposed between the two surface layers. It doesn't matter. Specifically, in addition to a 5-layer structure consisting of surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer, surface layer / adhesive layer / intermediate layer / intermediate layer / adhesive layer / surface layer, surface layer / regeneration Layer / adhesive layer / intermediate layer / adhesive layer / surface layer, surface layer / adhesive layer / recycled layer / intermediate layer / adhesive layer / surface layer, etc. / Middle layer / Adhesive layer / surface layer, surface layer / adhesive layer / intermediate layer / adhesive layer / intermediate layer / adhesive layer / surface layer, surface layer / recycled layer / adhesive layer / intermediate layer / adhesive layer / regenerated layer / surface layer, surface It is possible to demonstrate the power of 7 layers such as layer / adhesive layer / recycled layer / intermediate layer / recycled layer / adhesive layer / surface layer. In this case, the resin composition and thickness ratio of each layer may be the same or different.

 [0098] In the present lactic acid-based soft film, the thickness ratio of the intermediate layer to the total film thickness is

 It is preferably 35 to 90%. If the thickness ratio of the intermediate layer is within the range of force, it is easy to design a film that satisfies each characteristic value (Ε ', tan δ) by dynamic viscoelasticity. For example, the film is formed by the Τ die method. At this time, stable film formation stability can be obtained. In addition, it is possible to relatively easily impart mechanical properties for developing a cut property suitable for food packaging wrap films and relaxation properties for developing container adhesion. In addition, even when the formed film is stored in a rolled state, blocking does not occur, the antifogging property and container adhesion are good, and the molecular weight is not easily lowered due to hydrolysis over time. Thus, a packaging film having good adhesion between the layers can be obtained.

 Furthermore, when more importance is attached to stable film forming processability and flexibility, the thickness ratio of the intermediate layer to the total film thickness is preferably 35 to 65%, particularly 35 to 60%. Is more preferable.

 In addition, more importance is attached to cutability and container adhesion, as well as vegetation, that is, CO reduction.

 2

 When viewed, the thickness ratio of the intermediate layer to the thickness of the whole film is preferably 60 to 90%, more preferably 65 to 90%.

 If there are two or more intermediate layers as described above, the thickness ratio should be calculated using the total thickness of all intermediate layers! /.

[0099] The thickness (whole) of the present lactic acid-based flexible film can be used as a wrapping film for food packaging, specifically 6 H m to 30 [I m, preferably 10 m to 20 μm.

[0100] <Film characteristic value>

 Considering the use of this lactic acid-based soft film as a wrapping film for food packaging,

According to the dynamic viscoelasticity measurement method described in JIS K-7198 A method, the vibration frequency is 10 Hz. The storage elastic modulus (Ε ') at 20 ° C measured at 0 · 1% is in the range of 100MPa to 4GPa. S is preferable. Especially, it is lGPa to 4GPa for use in small roll film. Is preferred.

 When a film is used as a wrapping film for food packaging, the elastic modulus value near room temperature is an index. Therefore, if the storage elastic modulus (Ε ') at 20 ° C is lOOMPa or more, the films do not adhere to each other or at room temperature due to excessive flexibility, and 4GPa or less. For example, since the film does not become too hard and stretches appropriately, it is advantageous in food packaging wrap film applications.

 If the storage elastic modulus (Ε ') force is less than GPa, the film is too soft and the stress is too small for deformation. For example, the cutability when pulled out from a paper box and cut may deteriorate. LGPa or more is preferable.

[0101] In the same measurement, the loss tangent (tan δ) value at 20 ° C is preferably in the range of 0.;! To 0.8, and more preferably in the range of 0.1 to 0.3. It is preferable.

 The peak value of loss tangent (tan δ) is a physical property indicating the delay of deformation when force is applied, and is one of the parameters indicating the stress relaxation behavior. If the loss tangent value is small, the relaxation behavior of the finoleum is fast, and conversely, if the value is large, the stress relaxation is slow. If the loss tangent (tan δ) value at 20 ° C is 0.1 or more, the restoration behavior against deformation of the film does not occur instantaneously, and if it is 0.8 or less, the restoration behavior is not too slow. Therefore, it is suitable as a wrapping film for food packaging.

[0102] Further, in the same measurement, the peak temperature of the loss tangent (tan δ) is preferably 20 ° C to 60 ° C, and the peak value is preferably in the range of 0.8;

 When the peak temperature of tan δ is 60 ° C or lower and the peak value is 0 · 1 or higher, there is no instantaneous recovery behavior against film deformation. It is preferable because the film is not restored for a short time and the adhesion to the container is improved. In addition, if the peak temperature of tan δ is 20 ° C or higher and the peak is 0.8 or lower, plastic deformation is not exhibited, so there is no problem in normal use, which is preferable. .

[0103] Note that tan δ (loss tangent) is the ratio of the loss elastic modulus (Ε ") to the storage elastic modulus (Ε '). In other words, it is the loss tangent (tan δ = Ε "/ 、 '). In the temperature range where this value is high, the loss elastic modulus (Ε") of the material, that is, the contribution ratio of the viscosity in the viscoelastic properties becomes large. By evaluating the value of tan δ and high! /, And the temperature range where the value is shown, it will be a large standard for judging the adhesion to the container during packaging and the stress relaxation behavior of the film during the packaging process.

 In order to produce a film satisfying the storage elastic modulus (Ε ′) and loss tangent (tan δ) as described above, for example, an intermediate layer and a surface layer (including an adhesive layer and a reproduction layer in some cases) Component selection in (type of resin as main component, its molecular weight and Tg, type of plasticizer, blending ratio of components, LD ratio of lactic acid polymer and lactic acid copolymer), intermediate layer and surface layer The thickness ratio (including the thickness ratio of the adhesive layer and the recycled layer in some cases), the film forming method, and the processing conditions (for example, the heat treatment conditions after film formation) are appropriately adjusted in a balanced manner. I can do it.

 [0105] <Production method>

 Next, a method for producing the present lactic acid-based soft film will be described.

 [0106] First, when the constituent raw materials of each layer are a mixed composition, it is preferable that the constituent raw materials of each layer are mixed in advance and pelletized as necessary.

 As a mixing method at this time, for example, it may be pre-compounded in advance using a same-direction twin-screw extruder, a kneader, a Heishenol mixer or the like, or each raw material may be dry-blended and directly into a film extruder. You may make it throw in. In any mixing method, it is preferable to pre-compound in order to uniformly mix the force that needs to consider a decrease in molecular weight due to decomposition of the raw material. For example, in the case of an intermediate layer, a lactic acid-based polymer, a lactic acid-based copolymer, and additives as necessary are sufficiently dried to remove water, and these are melt-mixed using a twin-screw extruder. Then, a pellet may be produced by extruding into a strand shape while adding a predetermined amount of plasticizer from the vent port.

 At this time, it is preferable to appropriately select the melt extrusion temperature in consideration of the viscosity of the mixture changing depending on the mixing ratio of the lactic acid polymer, the lactic acid copolymer and the plasticizer. In practice, it is preferable to select a temperature range of 160-230 ° C.

Next, the constituent materials of each layer may be separately put into an extruder, melt extruded, and coextruded by T-die molding or inflation molding to be laminated. At this time, it is practically preferable to form a film by pulling the melt extruded from the τ die as it is while rapidly cooling it with a casting roll or the like.

 [0108] When importance is attached to the heat resistance and cutability of the film, the melt-extruded sheet is cooled and solidified by a cooling roll, and then heated to a temperature equal to or lower than the resin crystallization temperature, and the difference in speed between the nip rolls is utilized. It is preferable to adopt a longitudinal stretching method in which the film is stretched 1.2 to 5 times in the longitudinal direction, or a flat stretching method in which biaxial stretching and / or simultaneous biaxial stretching is performed 1.2 to 5 times in both the longitudinal and transverse directions of the film.

 [0109] Further, when importance is placed on productivity and / or economy, it is preferable to melt-extrusion a material resin from an annular die and perform inflation molding. In addition, as a cooling method at that time, either a method of cooling from the outer surface of the tube or a method of cooling from both the outer surface or the inner surface of the tube may be used.

 [0110] The film thus obtained can be subjected to longitudinal stretching between heating rolls as necessary, in accordance with the purposes such as reduction of heat shrinkage and natural shrinkage, and suppression of occurrence of width shrinkage. Heat treatment such as heat setting and aging may be performed.

 [0111] The stretching temperature is usually 120 ° C or less at the surface temperature at the stretching start point of the film (in the case of inflation, the position where expansion starts as a bubble), and is preferably 100 ° C or less. Is more preferable.

 Examples of the stretching method include a roll stretching method, a tenter method, and inflation. Among these, a method of forming a film by simultaneous biaxial stretching is preferable in terms of stretching. If the inflation method is used, biaxial simultaneous stretching can be achieved, high productivity can be produced at a relatively low cost, and the ability to make the shape into a bag (seamless) can be achieved. Therefore, it is particularly suitable for the production of bags and knocks, such as take-out bags for supermarkets, bags for preventing condensation from getting wet around cold food packs such as frozen foods and meat, and compost bags. .

 Combined with the coextrusion method, a multilayer film can be produced with high productivity using a plurality of resin compositions and / or other types of polymers according to the present invention having different properties.

[0112] The heat treatment condition is preferably a temperature of 40 ° C to 120 ° C, particularly preferably 5 0 ° C ~; 110 ° C. If the heat treatment temperature is 40 ° C or higher, the heat treatment effect can be obtained immediately.

If it is 120 ° C or less, the elastic modulus will not be too low.

[0113] For the purpose of imparting or promoting antifogging properties, antistatic properties, adhesiveness, and the like, treatment such as corona treatment and aging, and surface treatment and surface treatment such as printing and coating may be performed.

[0114] <Application>

 This lactic acid-based soft film is used for shopping bags, garbage bags, compost bags, food confectionery packaging films, food wrap films, cosmetic and cosmetic wrap films, pharmaceutical wrap films, herbal medicine wrap films, stiff shoulders and sprains, etc. Wrapping film for surgical patches, sanitary materials (paper diapers, sanitary products), agricultural 'horticultural film, agrochemical wrap film, greenhouse film, fertilizer bag, video and audio, etc. Magnetic tape cassette product packaging film, floppy disk packaging film, plate making film, adhesive tape, tape, waterproof sheet, sandbag bag, etc. In particular, it can be suitably used as a food wrap film.

[0115] The upper limit and lower limit of the numerical range in the present invention are the same as those in the numerical range as long as the upper and lower limits are slightly outside the numerical range specified by the present invention. It is included in the equivalent scope of the present invention.

 Example

 [0116] Examples will be shown below, but the present invention is not limited by these.

[0117] <Example (1 1)>

 As a polyolefin polymer (A), an ethylene acetate butyl copolymer “: LV440” manufactured by Nippon Polyethylene Co., Ltd. (butyl acetate content: 15% by mass, MFR: 2.2 g / 10 minutes, hereinafter abbreviated as “a-1”) )

 As a lactic acid polymer (B-1), a crystalline polylactic acid NatureWorks4 032D (L lactic acid / D lactic acid = 98.6 / 1/4, manufactured by NatureWorks, weight average molecular weight: 200,000, hereinafter "b-11" Abbreviated)

As lactic acid series copolymer (B- 2), 'a copolymer of dicarboxylic acid (lactic acid and propylene glycol' the lactic acid polymer and diol copolymer of succinic acid, lactic acid: 48 mol _^0/0, propylene grayed Rikonore: 26 Monore _^0/0, succinic acid: 26 mol _^0/0, a weight average molecular weight: 60,000, Tg: 10 ° C, hereinafter " b— 2 1 ”),

 As the plasticizer (C), acetylated monoglyceride (RIKEN Vitamin Riquemar PL-019, hereinafter abbreviated as “c 1”) was used.

 [0118] The mixing ratio is b 1—1: b 2—1 = 60: 40 by mass ratio, and c—1 is 10 parts by mass with respect to 100 parts by mass of the mixed composition of b 1 1 and b 2—1. It was.

 The lactic acid copolymer B-2 has one maximum value of loss tangent (tana) in dynamic viscoelasticity measurement (JIS K-7198 A method; strain 0.1%, vibration frequency 10 Hz). This type of copolymer was a mixture of lactic acid-based polymer b-1-1 and lactic acid-based copolymer b-21 having a single glass transition temperature.

 [0119] Regarding the resin composition forming both surface layers, 100 parts by mass of a polyolefin-based polymer (a-1) and diglycerin monooleate "DGO-l" manufactured by Riken Vitamin Co., Ltd. as an antifogging agent The mass part was put into a same-direction twin screw extruder set at an extrusion set temperature of 180 to 200 ° C., melted and kneaded, and extruded into a strand shape to produce pellets.

[0120] For the resin composition forming the intermediate layer, the lactic acid-based polymer (b-1 1) and the lactic acid-based copolymer (b-2 1) were sufficiently dried to remove moisture, The ratio b— 1 l: b-2-l = 60:40 was dry blended and melt-kneaded at a set temperature of 180 ° C using a Mitsubishi Heavy Industries 40mm φ small co-axial twin screw extruder. . -1 1 ₃ - 1 1 1 ₃ - the total amount 100 parts by weight of 2-1 was injected from the vent port at a rate of 10 parts by weight, melt mixed kneaded at 180 ° C, the pellets into a strand shape extruded It was created.

 [0121] The pellets prepared as described above were put into separate extruders and merged, and co-extruded with a three-layer T die temperature of 200 ° C and a die gap of 2mm, and cast into a cast roll set at a temperature of 30 ° C. By rapidly cooling, a packaging film having a total thickness of 12 m (surface layer / intermediate layer / surface layer = 3 m / 6 μm / 3 μm) was obtained. The results of evaluating the obtained film are shown in Table 1.

 [0122] <Example (1 2)>

In Example (1 1), as the lactic acid polymer (B-1), b-1 1 and Nature Works4060D (L lactic acid / D lactic acid = 87/13, weight average molecular weight: 190,000, hereinafter “b— 1−2 ”) is used in the same manner as in Example (1 1) except that the mass ratio is b-ll: bl-2 = 30: 70. Get a 12 m thick film It was.

 The obtained film was evaluated for storage elastic modulus (E and loss tangent (tan δ)), heat resistance, antifogging property, adhesion and bleeding property at 20 ° C. The results are shown in the table.

[0123] <Comparative example (1 1)>

 In Example (1 1), the pellets pre-compounded in advance so as to have the same composition as the middle layer of Example (1 2) were put into the extruder for both surface layers. A wrapping film for food packaging having a total thickness of 12 m was obtained in the same manner as in Example (11) except that a single layer film was used. The results of evaluating the obtained film are shown in Table 1.

[0124] <Comparative Example (1 2)>

 In Example (11), the same composition as in Example (12) was put into an intermediate layer extruder to make a substantially single layer film. Thus, a food packaging wrap film having a total thickness of 12 m was obtained. The results of evaluating the obtained film are shown in Table 1.

[0125] (Measurement and evaluation method)

 The films obtained in the above Examples (11) to (; 12) and Comparative Examples (11) to (; 12) were evaluated by the following methods.

[0126] (1) Dynamic viscoelastic properties

 By using the dynamic viscoelasticity measurement method described in JIS K 7198 A method, the transverse direction of the film (TD, flow from the extruder of the film) using a spectro-rheometer “VES-F3” manufactured by Iwamoto Seisakusho Co., Ltd. Measurement was performed at a vibration frequency of 10 Hz, a strain of 0.1%, and a temperature of 20 ° C, and the storage modulus (Ε ') and loss tangent (tan S) at a temperature of 20 ° C were obtained.

[0127] (2) Wet heat durability

 The obtained film was placed in a constant temperature and humidity chamber LH-112 made by Tabay Espec adjusted to 40 ° C. × 90% by mass for 1 month. The feel of the film after the test was evaluated according to the following criteria.

 A: The appearance and feel of the film are almost the same as before the test.

 A: The film strength is slightly reduced from before the test, but there is no practical problem.

 X: A state in which the film strength is extremely reduced and breakage occurs during rewinding.

[0128] (3) Film formation stability When the film was formed by the T-die molding method, the casting stability and the degree of sticking to the roll were observed and evaluated according to the following criteria.

 A: Extremely stable.

 ○: Stable.

 X: Slightly unstable.

[0129] (4) Blocking resistance

 The obtained roll of film was stored in a temperature-controlled room at a temperature of 43 ° C and a relative humidity of 40% for 5 days, and then the surface condition and rewinding property were observed and evaluated according to the following criteria.

 A: There is no blocking between films.

 A: Peeling is slightly heavy due to blocking between films.

 X: The film cannot be peeled off due to blocking between the films and cannot be rewound.

[0130] (5) Container adhesion

 Put water (50 cc) into a bowl-shaped ceramic container with a diameter of 10 cm and a depth of 5 cm, wrap the entire container with the resulting film, and store it at 0 ° C for 15 hours to maintain the film adhesion to the container. evaluated.

 A: The film sticks to the container in a firm state!

 ◯: The film and the container are displaced, and some slack is generated.

 X: Almost no contact.

[0131] (6) Anti-fogging property

 Put water (50 cc) into a bowl-shaped ceramic container with a diameter of 10 cm and a depth of 5 cm, wrap it with a film to seal the opening of the bowl, and evaluate the cloudiness after storage at 0 ° C for 30 minutes did. A: Transparent and clearly visible inside.

 ◯: The surface is fine and droplets are visible.

 X: It is clouded white.

[0132] [Table 1]

[0133] (Discussion)

 As is apparent from Table 1, the films obtained in Examples (1-1) to (; 1 2) were blocked even if they were stored in a wound state. In addition, it was confirmed that the film was a polylactic acid food packaging film having good antifogging properties and container adhesion, and less likely to cause a decrease in molecular weight due to hydrolysis over time.

 On the other hand, in the case where the front and back layers are mainly composed of a polyolefin-based polymer (Comparative Example (11)), the container adhesion is good, but the blocking and antifogging properties are not good. It was confirmed that there was a problem because it was sufficient, and further, the molecular weight decreased due to hydrolysis over time, and it was confirmed that there was a problem due to insufficient practical characteristics. In the case (Comparative Example (12)), which has a polylactic acid-based polymer composition as the main component! / In the case (Comparative Example (12)), blocking and anti-fogging properties are good. It was confirmed that it was insufficient.

<Example (2-1)>

For the resin composition forming both surface layers, a linear low density polyethylene “NUCG5225” (density: 0 · 92 g / cm ³ , MFR: 2. from Nippon Tunica Co., Ltd.) as the polyolefin polymer (A). (Og / 10 min) 100 parts by weight and 5.0 parts by weight of diglycerin monooleate “DGO-1” manufactured by Riken Vitamin Co., Ltd. as an antifogging agent were set at an extrusion temperature of 180 to 200 ° C. It was put into an extruder and melt kneaded.

On the other hand, for the resin composition forming the intermediate layer, “NatureWorks4060D” manufactured by NatureWorks (L-form / D-form = 87/13, weight average molecular weight: 200,000) was used as the lactic acid polymer (B-1). As a lactic acid copolymer (B-2), “Puramate PD-350” manufactured by Dainippon Ink and Chemicals Co., Ltd. (polylactic acid and propylene glycol succinic acid copolymer / polylactic acid: 48 mol%, Propylene glycol: 26 mol%, succinic acid: 26 mol% / weight average molecular weight: 58,000), and mixed at a mass ratio of B— 1 / B— 2 = 20/80, 100 parts by mass Nisshinbo Co., Ltd. “Carpolite HMV—8 CA” was added as a carpositimide compound at a rate of 1 part by mass, and the melt was put into the same direction twin-screw extruder set at a preset extrusion temperature of 180 to 200 ° C. After kneading, the adhesive layer extruder (F — 1) is an adhesive resin (F-1) component made by Asahi Kasei Co., Ltd. H1041 ”(styrene / ethylene / butadiene copolymer) (hereinafter abbreviated as“ fl ”) was added. Then, the resin composition forming both surface layers melted and kneaded as described above, the resin composition forming the intermediate layer, and the resin composition forming both adhesive layers are joined from separate extruders. 5 layers T co-extrusion at 200 ° C die temperature, 2mm die gap, and quenching with a cast roll set at 30 ° C temperature, total thickness 12m (surface layer / adhesive layer / intermediate layer / adhesive layer) / Surface layer = 2 m / 1 μm / 6 μ / 1 μ / 2 μm). The results of evaluating the obtained film are shown in Table 2.

 [0135] <Example (2-2)>

 In Example (2 1), the mass ratio of the resin composition forming the intermediate layer was changed to B—1 / B—2 = 40/60 by mass ratio, and the addition amount of the carpositimide compound was changed to 0.5 parts by mass. The total thickness was 12 ^ 111 (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm) in the same manner as in Example (2-1). m / 2 μm) packaging film was obtained. The results of evaluating the obtained film are shown in Table 2.

 [0136] <Example (2-3)>

 In Example (2 1), the mass ratio of the resin composition forming the intermediate layer was B 1 / B—2 = 60/40 by mass ratio, and the plasticizer (C) was acetylene manufactured by Riken Vitamin Co., Ltd. Except for melt kneading while injecting the monoglyceride “Riquemar PL019” (molecular weight 420) from the first vent port of the bi-axial extruder in the same direction to 5 parts by mass using a metering pump. Same as (2-1), total thickness 12 ^! 11 (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm / 2 μm ) Packaging film was obtained. Table 2 shows the results of evaluating the obtained film.

 [0137] <Example (2-4)>

 In Example (22), the component (F-1), which is an adhesive resin, was added to the extruder for the adhesive layer using “Primalloy A1800” (thermoplastic polyester block copolymer and styrene ethylene butadiene block manufactured by Mitsubishi Chemical Corporation). A total thickness of 12 m (surface layer / adhesive layer / intermediate layer / adhesive) in the same manner as in Example (2-1) except that the mixture was changed to a mixture with a copolymer (hereinafter abbreviated as “f 2”). Layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm / 2 μm). The results of evaluating the obtained film are shown in Table 2.

[0138] <Example (2-5)> In Example (2-3), the same procedure as in Example (2 1) except that as plasticizer (C), adipate ester “P X-884J (molecular weight 650)” manufactured by Asahi Denka Co., Ltd. was used. A packaging film having a total thickness of 12 μm (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm / 2 μm) was obtained. Table 2 shows the results of evaluating the films.

[0139] <Example (2-6)>

 In Example (2-3), the polyolefin polymer (A) was converted to an ethylene acetate butyl copolymer “: LV440” manufactured by Nippon Polyethylene Co., Ltd. (butene acetate content: 15 mass%, density: It was changed to 0.9 g MFR: 2.0 g / 10 min), and the component (F-1), which is an adhesive resin, was changed to Kuraray Co., Ltd. “Nobler 5125” (Styrene mono-butyl isopropylene block copolymer). Except for changes, the total thickness was 12 ^ 111 (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1) as in Example (2-1). μm / 2 μm) packaging film was obtained, and the results of evaluating the film are shown in Table 2.

[0140] <Reference example (2 1)>

 In Example (21), the adhesive resin component was added to an adhesive layer extruder “Sumitomo Chemical Co., Ltd. Bond First” (ethylene acrylate glycidyl methacrylate terpolymer) ( The total thickness is 12 m (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm) in the same manner as in Example (2-1) except that it is changed to “f3”. m / 6, ι m / 1 11 m / 2 μm). The results of evaluating the obtained film are shown in Table 2.

[0141] <Reference example (2-2)>

 In Example (21), pellets pre-compounded in advance so as to have the same composition as the intermediate layer in Example (21) were put into the adhesive layer extruder, and a substantially three-layer film was obtained. In the same manner as in Example (2-1), a packaging film having a total thickness of 12 m (surface layer / intermediate layer / surface layer = 1 · ^ ιΐ ΧΆ / ζ) ιι τΐ / 1.5 m) was used. Obtained. The results of evaluating the obtained film are shown in Table 2.

[0142] (Measurement and evaluation method)

The films obtained in Examples (2— ;!) to (2-6) and Reference Examples (2— ;!) to (2-2) were evaluated by the following methods. Here, the flow direction of the film from the extruder is referred to as the longitudinal direction (hereinafter sometimes referred to as “MD”), and the perpendicular direction thereof is referred to as the transverse direction (hereinafter sometimes referred to as “TD”).

[0143] (l) E, tan S

 Using the dynamic viscoelasticity measurement method described in JIS K-7198 A method, using the dynamic viscoelasticity measuring device “DVA-200” manufactured by IT Measurement & Control Co., Ltd. Measured from 50 ° C to 150 ° C at a temperature rise rate of 1 ° C / min at a frequency of 10Hz and a strain of 0.1%. From the obtained data, the storage elastic modulus at a temperature of 20 ° C (Ε ') And the peak temperature of the loss tangent (ta η δ) and its peak value were determined.

[0144] (2) Film formation stability

 When the film was formed by the Τ die forming method, the casting stability and the degree of sticking to the roll were observed and evaluated according to the following criteria.

 ◎: Extremely stable

 Y: Stable

 △: Slightly unstable but possible in actual production

 X: Level that is unstable and causes problems in actual production

[0145] (3) Blocking resistance

 The obtained roll of film was stored in a temperature-controlled room at a temperature of 43 ° C and a relative humidity of 40% for 5 days, and then the surface condition and rewinding property were observed and evaluated according to the following criteria. A: No blocking between Finolems

 ◯: Level where there is a little blocking between films, but there is no practical problem. △: Level where peeling is somewhat heavy due to blocking between films.

 X: Unable to roll back due to blocking between films

[0146] (4) Container adhesion

 Adhesion to a container when it was packaged in a bowl-shaped ceramic container with a diameter of 10 cm and a depth of 5 cm was evaluated according to the following criteria.

 ◎: Level for moderate packaging

 ○: It spreads out from the container shape a little, but there is a practical problem! /, Level

X: The film spreads along the container! [0147] (5) Anti-fogging property

 Attach the film to the opening on one side of a SUS304 cylinder with a diameter of 50 mm and a height of 80 mm without any film in an environment with an outside air temperature of 0-5 ° C. The cylindrical end of 30 mm was immersed in water at a water temperature of 20 ° C, and after 1 hour from the start of immersion, the antifogging property was visually observed and evaluated according to the following criteria.

 ◎: Water becomes a uniform water film, no water droplets

 ○: Water becomes a uniform water film! /, The power is fine in some places! /, With water droplets

 △: There are water droplets of about lmm in diameter

 X: Water droplets with a diameter of about 3mm

[0148] (6) Delamination strength

 The strength when the formed film was peeled off at a test speed of 200 mm / min by a T-type peeling method in a 23 ° C, 50% RH environment was evaluated according to the following criteria.

 ◎: 500g / l 5mm width or more

 ○: 200g / l 5mm width or more 500g / l less than 5mm

 △: 50g / l 5mm width or more, less than 200g / l 5mm

 X: Less than 50g / 15mm

[0149] (7) Small rewinding aptitude

 200m / mii for the rewinding test of the formed film! The rewinding speed of up to 600m / min was evaluated!

 ◎: Small rewinding is possible without problems even at a winding speed of 600m / min.

 ○: Small rewinding is possible without problems at a winding speed of 200m / min or more and less than 600m / min.

 X: 200 m / min or more and less than 600 m / min Delamination and film breakage occur during rewinding.

[0150] [Table 2]

[0151] From Table 2, the films obtained in Examples (2— ;!) to (2-6) did not block even when stored in a state where the formed film was wound, and further, It was confirmed that the antifogging property and the container adhesion were also good. In addition, it was confirmed that by providing a specific adhesive layer, the delamination strength was improved, and as a result, a packaging film excellent in small rewindability was obtained. In contrast, in Reference Example (2 1) and Reference Example (2-2), ethylene / epoxy / alkyl acrylate, which is an acrylic-modified polyethylene resin, is used as an adhesive layer between the front and back layers and the intermediate layer. Since the polymer is used, the delamination strength becomes insufficient and delamination occurs during small rewinding (Reference Example (2 1)), or because there is no adhesive layer, delamination is noticeable during small rewinding. A case where fracture occurred (Reference Example (2-2)) was confirmed.

 [0152] <Example (3-1)>

For the resin composition forming both surface layers, the ethylene acetate butyl copolymer “: LV440” manufactured by Nippon Polyethylene Co., Ltd. as the polyolefin polymer (A) (butyl acetate content: 15 mass%, MFR: 2 2g / 10min) (hereinafter abbreviated as “A-1”) and 100 parts by weight of diglycerin monooleate “DGO-1” manufactured by Riken Vitamin Co., Ltd. as an antifogging agent. Then, it was put into a same-direction twin screw extruder set at an extrusion set temperature of 180 to 200 ° C. and melt kneaded. On the other hand, for the resin composition forming the intermediate layer, “NatureWorks4060D” manufactured by NatureWorks (L-form / D-form = 87/13, weight average molecular weight: 200,000) was used as the lactic acid polymer (B-1). As a lactic acid copolymer (B-2), “Puramate PD-350” manufactured by Dainippon Ink and Chemicals Co., Ltd. (polylactic acid and propylene glycol succinic acid copolymer / polylactic acid: 48 mol%, Propylene glycol: 26 mol%, succinic acid: 26 mol% / weight average molecular weight: 58,000), and mixed at a mass ratio of B— 1 / B— 2 = 20/80, 100 parts by mass Nisshinbo Co., Ltd. “Carpolite HMV—8 CA” was added as a carpositimide compound at a rate of 1 part by mass, and the melt was put into the same direction twin-screw extruder set at a preset extrusion temperature of 180 to 200 ° C. Furthermore, Mitsui DuPont Polychemi is used as the component (F 2), which is an adhesive resin, in the adhesive layer extruder. An ethylene acetate butyl copolymer “Evaflex 45LX” (Bull acetate content: 46 mass%, MFR: 2.5 g / 10 min) (hereinafter abbreviated as “f4”) was added. And the resin composition that forms both surface layers melt-kneaded as described above, the resin composition that forms the intermediate layer, and the resin composition that forms both adhesive layers, Combined from separate extruders, co-extruded at 5 layers T die temperature 200 ° C, die gap 2mm, and quenched with cast roll set at 30 ° C, total thickness 12m (surface layer / adhesion Layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 am / 6, i / 1, im / 2 11 m).

 The results of evaluating the obtained film are shown in Table 3.

 [0153] <Example (3-2)>

 In Example (3 1), the mass ratio of the resin composition forming the intermediate layer was changed to B—1 / B—2 = 40/60 by mass ratio, and the addition amount of the carpositimide compound was changed to 0.5 parts by mass. The total thickness was 12 ^ 111 (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm) in the same manner as in Example (31). / 2 μm) packaging film was obtained. The results of evaluating the obtained film are shown in Table 3.

 [0154] <Example (3-3)>

 In Example (3 1), the mass ratio of the resin composition forming the intermediate layer was B 1 / B—2 = 60/40 by mass ratio, and the plasticizer (C) was acetylene manufactured by Riken Vitamin Co., Ltd. Except for melt kneading while injecting the monoglyceride “Likemar PL019” (molecular weight 420) from the first vent port of the biaxial extruder in the same direction to 5 parts by mass using a metering pump. Same as (3 1), total thickness 12 ^! 11 (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm / 2 μm) A packaging film was obtained. Table 3 shows the results of evaluating the obtained film.

 [0155] <Example (3-4)>

 In Example (3-2), the component (F-2), which is an adhesive resin, was added to an extruder for an adhesive layer, and an ethylene acetate butyl copolymer “Evaflex 40 LXJ (Mitsui DuPont)” manufactured by Polychemical Co., Ltd. Butyl acetate content: 41% by mass, MFR: 2. Og / 10 min. (Hereinafter abbreviated as “f5”). / Adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1 μm / 6 μm / 1 μm / 2 μm). The results of evaluating the obtained film are shown in Table 3.

 [0156] <Example (3-5)>

In Example (3 1),! /, The polyolefin polymer (A) was made by Nippon Tunica Co., Ltd. Total thickness of 12 ^ m (surface), except that the chain low density polyethylene “NUCG5225” (density: 0.92 g / cm ³ , MFR: 2. Og / 10 min) was used. Layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / 1, im / 6, im / 1, im / 2, im). The results of evaluating the obtained film are shown in Table 3.

[0157] <Reference example (3-1)>

In Example (31), the polyolefin polymer (A) was converted to a linear low density polyethylene “NUCG5225” (density: 0.92 g / cm ³ , MFR: 2) manufactured by Nippon Tunica Co., Ltd. Og / 10 min), and the adhesive resin component is added to the extruder for the adhesive layer, “bond first” (ethylene acrylate glycidyl methacrylate terpolymer) by Sumitomo Chemical Co., Ltd. Body) (hereinafter abbreviated as “f3”) in the same manner as in Example (3 1) except that the total thickness was 12 m (surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer = 2 m / A packaging film of 1 am / 6, i / 1, im / 2 [I m) was obtained. The results of evaluating the obtained film are shown in Table 3.

Yes

 [0158] <Reference example (3-2)>

 In Example (31), pellets pre-compounded to have the same composition as that of the intermediate layer in Example (31) were put into the adhesive layer extruder, so that a substantially three-layer film was obtained. A packaging film having a total thickness of 12 m (surface layer / intermediate layer / surface layer = 1 · ^ ιΐ ΧΆ / ζ) ιι τΐ /1.5 m) was obtained in the same manner as in Example (31). It was. The results of evaluating the obtained film are shown in Table 3.

 [0159] (Measurement and evaluation method)

 For the films obtained in Examples (3— ;!) to (3-5) and Reference Examples (3— ;!) to (3-2)! —;!) To (2-6) were evaluated in the same manner.

[0160] [Table 3]

(Discussion)

 From Table 3, the films obtained in Examples (3— ;!) to (3-5) show no blocking even when stored in a state in which the formed film is wound, and are further antifogging. It was also confirmed that the container adhesion was good. In addition, it was confirmed that by providing a specific adhesive layer, the delamination strength was improved, and as a result, delamination was suppressed and a packaging film excellent in small rewindability was obtained.

 In contrast, in Reference Example (3-1) and Reference Example (3-2), ethylene / epoxy / alkyl acrylate, which is an acrylic-modified polyethylene resin, is used as the adhesive layer between the front and back layers and the intermediate layer. Since the copolymer is used, the delamination strength is insufficient and delamination occurs during small rewinding (Reference Example (3-1)), or because there is no adhesive layer, delamination does not occur during small rewinding. A case where the film breaks significantly (Reference Example (3-2)) was confirmed. In addition, the films obtained in Examples (3— ;!) to (3-5) were used as an adhesive layer between the front and back layers and the intermediate layer as an acrylic-modified polyethylene resin, ethylene / epoxy / alkyl attairele. Compared with the reference example (3-1) using a salt copolymer, it was also excellent in transparency.

Claims

The scope of the claims

 [1] A multilayer lactic acid-based soft film comprising at least three layers,

 Both surface layers contain a polyolefin polymer (A) as a main component,

 The intermediate layer contains a lactic acid-based mixed resin composition (B) composed of a lactic acid-based polymer (B-1) and a lactic acid-based copolymer (B-2) as a main component. Soft film.

[2] Storage elastic modulus (Ε ') at 20 ° C measured at a vibration frequency of 10Hz and a strain of 0.1% by the dynamic viscoelasticity measurement method described in JIS K 7198 A method is in the range of 100MPa to 4GPa. The multilayer lactic acid-based soft film according to claim 1, wherein the loss tangent (tan δ) value at 20 ° C is in the range of 0 .;! To 0.8.

[3] A multilayer lactic acid-based soft film of 5 or more layers having at least a surface layer / adhesive layer / intermediate layer / adhesive layer / surface layer in this order,

 Both surface layers contain a polyolefin polymer (重合) as the main component,

 The intermediate layer contains a lactic acid-based mixed resin composition (系) composed of a lactic acid-based polymer (Β-1) and a lactic acid-based copolymer (Β-2) as a main component,

 Both adhesive layers are composed of a copolymer of soft aromatic hydrocarbon and conjugated gen hydrocarbon or a hydrogenated derivative of this copolymer (F-1), and a butyl acetate content of 30 to 80% by mass. Ethylene acetate butyl copolymer (F-2), modified polyolefin resin (F-3), lactic acid polymer, polymer block mainly composed of acrylate units and heavy polymer composed mainly of methacrylic ester units Contains lactic acid / acrylic mixed resin (F-4), which is a mixed resin with an acrylic block copolymer having a combined block, as the main component, an adhesive resin consisting of one or more combinations. The multilayer lactic acid-based soft film according to claim 1, wherein

 [4] Storage elastic modulus (Ε ') force measured at dynamic vibrational frequency 10Ηζ and temperature 20 ° C, SlGPa ~ 4GPa, and loss tangent (tan δ) peak temperature at 20 ~ 60 ° C 4. The multilayer lactic acid soft film according to claim 3, wherein the peak value is in the range of 0.;! To 0.8.

[5] Polyolefin polymer (A) Strength Low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, ethylene acetate butyl copolymer, ethylene acrylate 2. A mixed resin comprising at least one ethylene polymer selected from a steal copolymer and an ethylene-methacrylate copolymer or a combination of two or more of these. The multilayer lactic acid-type soft film in any one of -4.

[6] The multilayer lactic acid according to any one of claims 1 to 5, wherein the lactic acid polymer (B-1) is a mixed resin of two or more lactic acid polymers having different LD ratios. Soft film

Yes

 [7] The lactic acid-based mixed resin composition (B) has a single glass transition temperature measured at a heating rate of 10 ° C / min in differential scanning calorimetry. The multilayer lactic acid-based soft film according to any one of 1 to 6! /.

[8] The lactic acid-based mixed resin composition (B) was measured by the dynamic viscoelasticity measurement method described in the JIS K-7198 A method when measured at a vibration frequency of 10 Hz and a strain of 0.1%. The multi-layered lactic acid soft film according to any one of claims 1 to 6, wherein there is one maximum value of tan δ).

[9] The multilayer lactic acid-based copolymer according to any one of claims 1 to 8, wherein the lactic acid-based copolymer (Β-2) is a copolymer of a lactic acid-based polymer and a diol′dicarboxylic acid. Soft film.

[10] The multilayer lactic acid according to any one of claims 1 to 9, wherein the lactic acid copolymer (共 -2) is a copolymer of a lactic acid polymer, propylene glycol and succinic acid. Soft film.

 [11] The intermediate layer contains, as main components, a lactic acid polymer (と -1), a lactic acid copolymer (Β-2), and a plasticizer (C). The multilayer lactic acid-based soft film according to any one of 1 to 10;

 [12] The intermediate layer contains! To 15 parts by mass of a plasticizer (C) having a molecular weight of 2,000 or less with respect to 100 parts by mass of the lactic acid-based mixed resin composition (ii). ~ 11! /, Multi-layered lactic acid-based soft film as described in any one of the above.

[13] The intermediate layer further contains a polyolefin-based polymer (請求).

-; The multilayer lactic acid-type soft film in any one of 12.

[14] Polyolefin-based polymer (Α), lactic acid-based mixed resin composition (Β), and a copolymer of soft aromatic hydrocarbon and conjugated gen hydrocarbon or hydrogenation of these copolymers Invitation Conductor (F-1), ethylene acetate content of 30-80% by weight of ethylene acetate copolymer (F-2), modified polyolefin resin (F-3), lactic acid polymer and acrylate unit Lactic acid 'acrylic mixed resin (F4) which is a mixed resin of the polymer block and the acrylic block copolymer having a polymer block mainly composed of methacrylate units. 14. The multilayer lactic acid-based soft finem according to claim 1, further comprising a regeneration layer containing an adhesive resin composed of the above combination.