JP2008273004A - Laminated film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated film which is superior not only in transparency, flexibility, and adhesiveness required for a wrapping film, a stretch film and a bag body but also water vapor barrier properties, and in addition, in which bleeding out of a plasticizer and change with time in film characteristics are suppressed. <P>SOLUTION: The laminated film of the present invention is characterized in that it is a laminated film of at least two layers having a layer X of a resin composition C comprising an aliphatic polyester resin composition A and a plasticizer B, and a layer Y of a resin composition D comprising a polyvinylidene chloride resin and/or a polyvinylidene chloride copolymer resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laminated film, which not only can reduce the environmental burden by containing an aliphatic polyester, but also can significantly reduce water vapor barrier properties by laminating a vinylidene chloride-based resin, so that it is a wrap film, a stretch film, and a bag. The present invention relates to a laminated film that can be suitably used as a body.

  Conventionally, as a method of disposing of a polymer resin molded product used for packaging materials or the like, a method of processing by a method such as incineration or landfill has been long. In recent years, however, environmental issues such as greenhouse gas emissions due to incineration, a decrease in landfills, and leakage of harmful substances around landfills have become a major issue. In particular, a polyvinylidene chloride film represented by a wrap film contains a large amount of chlorine, and there is a concern that dioxins are generated due to incineration.

  Under such circumstances, aliphatic polyesters have attracted a great deal of attention as environmentally friendly materials that are degraded by enzymes and microorganisms. In particular, products related to molded products using polylactic acid have been actively developed. In particular, a film containing a polylactic acid resin has been actively developed in the fields of industrial materials and packaging materials.

  Polylactic acid is a polymer obtained by producing lactic acid from corn and other starches obtained from potatoes such as sweet potato, and by chemical synthesis. Among the aliphatic polyesters, mechanical properties, heat resistance, and transparency Due to its excellent properties, research and development for the purpose of developing various molded products such as films, sheets, tapes, fibers, ropes, non-woven fabrics, containers and the like have been actively conducted.

  However, in applications represented by wrap films, for example, the polylactic acid film itself is inferior in water vapor barrier properties, and it is difficult to prevent foods and other packages from being dried. Therefore, in many cases, a method of providing gas barrier properties by stacking other layers having excellent gas barrier properties is employed.

  For example, the technique regarding the gas barrier film which provided the inorganic compound layer in biodegradable resin, such as polylactic acid, is disclosed (for example, refer patent documents 1-3). However, providing an inorganic compound layer is an insufficient technique from the viewpoint of film flexibility and transparency, for example, in applications represented by wrap films.

  Also disclosed is a technique relating to a wrap film having high adhesion and gas barrier properties by laminating a layer made of polylactic acid softened with a liquid additive and a layer obtained by adding a liquid additive to an aliphatic / aromatic copolymer polyester resin. (For example, see Patent Documents 4 and 5). However, this technique is insufficient from the viewpoints of water vapor barrier properties for food packaging and bleeding out of additives and lactides.

On the other hand, a technique for applying gas barrier properties by applying a polyvinylidene chloride latex on one or both surfaces of a thermoplastic resin such as a crosslinked polyethylene film and forming a resin layer dried with hot air at 100 to 150 ° C. is disclosed. (See, for example, Patent Document 6). However, the base material is only described as a thermoplastic resin, and there is no disclosure of technology for reducing the environmental load. In addition, when applied to aliphatic polyester resins typified by polylactic acid, there is no description of technology for improving properties such as imparting flexibility. Furthermore, when polyvinylidene chloride latex is applied, polyvinylidene chloride due to poor coating is applied. There is a problem that the barrier property is insufficient because the layer formation is deteriorated.
JP 2006-44162 A JP 2004-202822 A JP 2004-114657 A JP 2002-88230 A JP 2002-178473 A Japanese Unexamined Patent Publication No. 55-59961

  In view of the background of the prior art described above, the present invention not only has excellent transparency, flexibility and adhesion required for wrap films, stretch films, bags, etc., but also has excellent water vapor barrier properties, and a plasticizer. It is an object of the present invention to provide an environmentally friendly laminated film in which the bleed-out of the film and the change with time of the film characteristics are suppressed.

As a result of intensive studies in order to solve the above problems, the present inventors have made the following invention.
(1) A layer X comprising a resin composition C containing an aliphatic polyester resin composition A and a plasticizer B, and a layer Y comprising a resin composition D containing a polyvinylidene chloride resin and / or a polyvinylidene chloride copolymer resin A laminated film having at least two layers.
(2) The laminated polyester film according to (1), wherein the aliphatic polyester resin composition A contains 30% by weight or more and 100% by weight or less of a polylactic acid resin.
(3) The constitution ratio of the crystalline polylactic acid resin a and the noncrystalline polylactic acid resin b constituting the polylactic acid resin satisfies the following relational expression, described in (2) Laminated film.

Composition ratio: 50 ≦ [100 × b / (a + b)] ≦ 90 (% by weight)
In the formula [100 × b / (a + b)] indicating the composition ratio, “a” represents the weight of the crystalline polylactic acid resin “a”, and “b” represents the weight of the amorphous polylactic acid resin “b”. .
(4) The laminated film according to any one of (1) to (3), wherein the constituent ratio of the aliphatic polyester resin composition A and the plasticizer B satisfies the following relational expression.

Composition ratio: 5 ≦ [100 × B / (A + B)] ≦ 50 (% by weight)
In the formula [100 × B / (A + B)] indicating the composition ratio, A represents the weight of the aliphatic polyester resin composition A, and B represents the weight of the plasticizer B.
(5) The plasticizer B has one or more polylactic acid segments having a weight average molecular weight of 1,500 or more in one molecule, and has a polyether-based and / or polyester-based segment. The laminated film according to any one of 1) to (4).
(6) The laminated film according to (5), wherein the weight ratio of the polylactic acid segment of the plasticizer B according to (5) is 5% by weight to 50% by weight of the entire plasticizer B .
(7) The resin composition D contains at least one vinyl group-containing monomer selected from polyvinyl chloride, acrylonitrile, vinyl acetate, and (meth) acrylic acid esters, using polyvinylidene chloride resin and / or vinylidene chloride as an essential component The laminated film according to any one of (1) to (6), wherein is a copolymerized resin composition.
(8) The laminated film according to any one of (1) to (7), wherein the relationship between the thicknesses of the layer X and the layer Y satisfies the following relational expression.

Lamination ratio: 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 50 (%)
In the formula [100 × (total of layer Y) / (total of layer X + total of layer Y)] indicating the stacking ratio, the total of layer X indicates the total thickness of all layers X in the stacked film, The total of layer Y shall show the total thickness of all the layers Y in a laminated film.
(9) The water vapor permeability in an environment of 40 ° C. and a humidity of 90% RH is 1000 g / (m ² · day · atm) or less, according to any one of (1) to (8) Laminated film.
(10) The laminated film according to any one of (1) to (9), which is used for a wrap film, a stretch film, or a bag.
(11) The method for producing a laminated film according to any one of (1) to (10), characterized by stretching in at least one direction.

  According to the present invention, not only is it excellent in transparency, flexibility, and adhesion, but also changes in physical properties over time can be suppressed, excellent characteristics can be maintained, and water vapor barrier properties are important when used as packaging materials. An excellent laminated film can be provided. Such a laminated film can be suitably used as a wrap film, a stretch film, a bag or the like.

  The present invention is not only excellent in transparency, flexibility, and adhesion required for the above-mentioned problem, that is, wrap film, stretch film, bag, etc., but also excellent in water vapor barrier properties, and further, bleed out of plasticizer and film As a result of intensive studies on laminated films in which the change in characteristics over time was suppressed, a layer containing an aliphatic polyester resin composition such as a polylactic acid resin and a plasticizer, a polyvinylidene chloride resin and / or a polyvinylidene chloride copolymer When a layer containing a resin is formed into a laminated film under conditions that satisfy a specific lamination relationship, it has been clarified that such problems can be solved all at once.

  That is, the laminated film of the present invention is a resin composition comprising a layer X comprising a resin composition C containing an aliphatic polyester resin composition A and a plasticizer B, and a polyvinylidene chloride resin and / or a polyvinylidene chloride copolymer resin. By having a layered structure of at least two layers having the layer Y composed of D, a more remarkable effect can be obtained in terms of balance of properties such as transparency, flexibility, adhesion, and barrier properties.

  Environmental load with basic characteristics such as wrap film, stretch film and bag as a whole, with layer Y taking on the barrier function that is the basic performance represented by wrap film and layer X taking on the reduction of environmental load It can be set as the laminated film which contributes to reduction.

  Specific examples of the laminated constitution of the laminated film of the present invention include a two-layer constitution of layer X / layer Y, a three-layer constitution of layer Y / layer X / layer Y and layer X / layer Y / layer X, layer X and layer The structure of four or more layers consisting of Y is mentioned. Further, by using other layers (referred to as other layers) other than the layer X and the layer Y, a configuration of three or more layers such as layer Y / other layer / layer X / other layer / layer Y is also possible. .

  In the laminated film of the present invention, preferably, at least one outermost layer is configured as layer Y, more preferably both outermost layers are defined as layer Y, specifically, layer Y / layer X / layer. Y is mentioned.

  As the laminated structure of three or more layers, at least the outer layer is preferably layer Y, which is preferable from the viewpoint of adhesion as a wrap film and changes in physical properties over time. Among them, with respect to changes in physical properties over time, hydrolysis of the aliphatic polyester resin composition A in the inner layer is greatly suppressed by the water vapor barrier effect of the layer Y, and even when the film is stored for a long period of time, there is little decrease in film properties. It can be used without problems.

  Furthermore, it is preferable that the lamination ratio of the layer X and the layer Y satisfies the following lamination ratio of Formula 2 from a viewpoint of the stretchability of a film.

Lamination ratio: 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 50 (%) (Formula 2)
In the formula [100 × (total of layer Y) / (total of layer X + total of layer Y)] indicating the stacking ratio, the total of layer X indicates the total thickness of all layers X in the stacked film, The total of layer Y shall show the total thickness of all the layers Y in a laminated film.

  That is, the stacking ratio [100 × (total of layer Y) / (total of layer X + total of layer Y)] is the stacking ratio of the thickness of layer Y to the total of the thickness of layer X and the thickness of layer Y ( %).

  More preferably, from the viewpoint of the adhesion between the layer X and the layer Y, the formula of the lamination ratio satisfies 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 20. More preferably, the lamination ratio formula satisfies 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 10.

  From the viewpoint of ensuring film-forming stability of the film by satisfying 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 50, the lamination ratio formula is satisfied. The laminated film of the invention preferably satisfies this formula.

  In addition, the adhesiveness of the layer Y is dramatically improved by forming the layer Y in the range of 0.01 to 10 μm as long as the barrier property of the laminated film of the present invention is not impaired. Also, the adhesive strength with the layer X is greatly improved. As a result, it becomes possible to drastically improve the stretching characteristics of the laminated film, and thus the overall film forming characteristics. Therefore, the thickness per layer of the layer Y is preferably 0.01 to 10 μm.

  Moreover, from the viewpoint of using the laminated film of the present invention as a wrap film, a stretch film, a bag, or the like, the thickness of the laminated film is preferably 5 to 100 μm, and more preferably 7 to 60 μm. In particular, when used as a wrap film, the thickness is preferably 7 to 15 μm from the viewpoint of good shape followability when wrapping articles.

  The layer Y used for this invention consists of the resin composition D containing a polyvinylidene chloride resin and / or a vinylidene chloride copolymer resin.

  Further, a more preferable embodiment of the layer Y is that at least one vinyl group-containing monomer selected from polyvinyl chloride, acrylonitrile, vinyl acetate, and (meth) acrylic acid esters having a polyvinylidene chloride resin and / or vinylidene chloride as an essential component. Is a case of comprising a resin composition D copolymerized.

  Further, the layer Y is preferably a polyvinyl chloride copolymer resin in which the resin composition D is composed of 70 to 90% vinylidene chloride and 10 to 30% vinyl chloride from the viewpoint of adhesiveness of a film represented by a wrap film. is there.

  In the laminated film of the present invention, the layer X needs to be composed of a resin composition C containing an aliphatic polyester resin composition A and a plasticizer B in order to develop flexibility typified by a wrap film.

  Furthermore, it is preferable that the constituent ratio of the aliphatic polyester resin composition A and the plasticizer B satisfies the constituent ratio of the following formula 3.

Composition ratio: 5 ≦ [100 × B / (A + B)] ≦ 50 (% by weight) (Formula 3)
In the formula [100 × B / (A + B)] indicating the composition ratio, A represents the weight of the aliphatic polyester resin composition A, and B represents the weight of the plasticizer B.

  In the case where the laminated film of the present invention has two or more layers X, in the formula [100 × B / (A + B)] indicating the composition ratio, A is an aliphatic polyester resin composition in all layers X of the laminated film. The total weight of the product A is shown, and B is the total weight of the plasticizer B in all the layers X of the laminated film.

  That is, the constituent ratio [100 × B / (A + B)] is the constituent ratio (% by weight) of the plasticizer B with respect to the total of the aliphatic polyester resin composition A and the plasticizer B.

  More preferably, from the viewpoint of the strength of the film, the handleability in use and the film forming property, the formula of the composition ratio satisfies 10 ≦ [100 × B / (A + B)] ≦ 40, and more preferably Is a case where the formula of the composition ratio satisfies 15 ≦ [100 × B / (A + B)] ≦ 30.

  From the viewpoint that the laminated film satisfies the formula 5 ≦ [100 × B / (A + B)] ≦ 50, the laminated film of the present invention satisfies this formula, from the viewpoint of imparting flexibility to the laminated film. preferable.

  Here, the aliphatic polyester resin composition A used in the present invention has a polylactic acid resin in an amount of 30% by weight or more and 100% by weight in 100% by weight of the aliphatic polyester resin composition A from the viewpoint of film strength and stability over time. % Or less is preferable. More preferably, the polylactic acid resin is 50% by weight or more and 100% by weight or less, and more preferably 70% by weight or more and 100% by weight or less, in 100% by weight of the aliphatic polyester resin composition A.

  Here, the polylactic acid resin used in the present invention is a polymer produced using L-lactic acid and / or D-lactic acid as a main starting material, and is used as the aliphatic polyester resin composition A of the laminated film of the present invention. From the viewpoint of adjusting the crystallinity of the polylactic acid resin, 70% by weight or more and 100% by weight or less of the polylactic acid resin component is a polylactic acid resin starting from L- or D-lactic acid. Is preferred. More preferably, 90% by weight or more and 100% by weight or less is a polylactic acid resin using L- or D-lactic acid as a starting material.

  Polylactic acid includes poly-L-lactic acid composed of L-lactic acid, poly-D-lactic acid composed of D-lactic acid, and a racemic body thereof, and the polylactic acid resin used in the present invention is composed of The proportion of L-lactic acid in the lactic acid component to be used is preferably 99 to 70% by weight, more preferably 99 to 80% by weight.

  Furthermore, it is preferable to use two or more types of polylactic acid resins having different crystallinity for the purpose of imparting or improving functions necessary for the film.

  Usually, the higher the optical purity of homopolylactic acid, the higher the crystallinity. For example, poly L-lactic acid having an optical purity of 98% or higher has a melting point of about 170 ° C. due to its crystallinity. When it is desired to impart high heat resistance, it is more preferable that at least one of the polylactic acid polymers used contains polylactic acid having an optical purity of 95% or more.

  Furthermore, it is preferable to use a polylactic acid resin having crystallinity and an amorphous polylactic acid resin in combination from the viewpoint of expressing the flexibility and adhesion of a film typified by a wrap film. Amorphous polylactic acid-based resin is a polylactic acid-based resin that does not exhibit a melting point and has substantially no crystal structure when subjected to differential scanning calorimetry (DSC) at a temperature increase rate of 20 ° C./min. It is. The crystallinity of the polylactic acid-based resin is controlled by the ratio of polylactic acid and / or optical purity of the constituent, and in the case of polylactic acid mainly composed of L-lactic acid, the ratio of D-lactic acid, that is, the co-ordination of D-lactic acid. As the polymerization amount increases, the melting point decreases as the crystallinity decreases, and the polylactic acid does not exhibit a melting point when the copolymerization amount is approximately 10% or more.

  The constituent ratios of the crystalline polylactic acid resin a and the amorphous polylactic acid resin b satisfy the following constituent ratios from the viewpoint of achieving both flexibility as a wrap film and heat resistance of 140 ° C. or higher. Is preferred.

Composition ratio: 50 ≦ [100 × b / (a + b)] ≦ 90 (wt%) (Formula 1)
In the formula [100 × b / (a + b)] indicating the composition ratio, “a” represents the weight of the crystalline polylactic acid resin “a”, and “b” represents the weight of the amorphous polylactic acid resin “b”. .

  In the case where the laminated film of the present invention has two or more layers X, in the formula [100 × b / (a + b)] indicating the constituent ratio, a is a crystalline polylactic acid type in all the layers X of the laminated film. The total weight of the resin a is shown, and b is the total weight of the amorphous polylactic acid resin b in all the layers X of the laminated film.

  In other words, the composition ratio [100 × b / (a + b)] is the ratio of the noncrystalline polylactic acid resin b to the entire polylactic acid resin (the total of the crystalline polylactic acid resin a and the noncrystalline polylactic acid resin b). The composition ratio (% by weight) is indicated.

  When the proportion of the amorphous polylactic acid resin b increases and [100 × b / (a + b)] exceeds 90% by weight, it has substantially no crystals, and therefore melts at a low temperature. Sufficient heat resistance may not be obtained. On the other hand, when the proportion of the amorphous polylactic acid resin b decreases and [100 × b / (a + b)] is less than 50% by weight, the flexibility represented by the wrap film may be inferior. Therefore, it is preferable to satisfy 50 ≦ [100 × b / (a + b)] ≦ 90.

  The polylactic acid resin used in the present invention preferably has a residual lactide content in the polylactic acid resin of 0.3% by weight or less in order to prevent contamination of the film-forming process due to lactide bleed out. When lactide remains in the polylactic acid-based resin in an amount of more than 0.3% by weight, the lactide bleeds out from the polylactic acid-based resin when a molded body such as a film is produced, which may contaminate the film forming process, for example. is there. Therefore, the residual lactide content in the polylactic acid resin is preferably 0.3% by weight or less.

A method for producing polylactic acid is to produce L-lactide, D-lactide and DL-lactide (racemate), which are cyclic dimers, using L-lactic acid and D-lactic acid as raw materials, and ring-opening polymerization of this lactide. There are a lactide method in which a polymer is obtained with a direct polymerization method and a direct polymerization method in which a polymer is obtained by direct dehydration condensation of lactic acid in a solvent. In the present invention, polylactic acid obtained by either polymerization method is used in the same manner. It is possible. However, in order to make the residual lactide content in the polylactic acid as described above 0.3% by weight or less, the direct polymerization method is more preferable.

  The polylactic acid resin used in the present invention has a number average molecular weight of preferably from 20,000 to 250,000, more preferably from 40,000 to 150,000, particularly preferably from 50,000, from the viewpoint of overall film properties, particularly mechanical properties. It should be 110,000.

  The polylactic acid resin used in the present invention may be a copolymerized polylactic acid obtained by copolymerizing monomer residues other than lactic acid with L-lactic acid and D-lactic acid. Include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, and other hydroxycarboxylic acids, and ester-forming glycol compounds, dicarboxylic acid compounds, and ester derivatives thereof. be able to. Specifically, examples of the glycol compound include ethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol and the like. Examples of the dicarboxylic acid compound include succinic acid, adipic acid, sebacic acid, fumaric acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and dimethyl ester derivatives thereof. it can. Among these, a copolymer component that does not particularly inhibit the biodegradability of polylactic acid can be preferably used. For example, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid And ethylene glycol, trimethylene glycol, tetramethylene glycol succinic acid, adipic acid, and sebacic acid.

  The method for obtaining the aliphatic polyester resin used in the aliphatic polyester resin composition A of the present invention other than the polylactic acid-based resin is not particularly limited, but an aliphatic diol, an aliphatic dicarboxylic acid, and an aliphatic hydroxycarboxylic acid are used. Various combinations can be obtained from the polycondensation reaction.

  Examples of the aliphatic diol used here include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, and 3-methyl-1. , 5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, 1,4-benzenedimethanol and the like. . These may be used alone or in combination of two or more.

  Examples of the aliphatic dicarboxylic acid include succinic acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, phenylsuccinic acid, 1 , 4-phenylenediacetic acid and the like. These may be used alone or in combination of two or more.

  Examples of the aliphatic hydroxycarboxylic acid include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, and the like. Examples include cyclic esters of aliphatic hydroxycarboxylic acids, for example, glycolide, which is a dimer of glycolic acid, and ε-caprolactone, which is a cyclic ester of 6-hydroxycaproic acid. These may be used alone or in combination of two or more.

  From the viewpoint of combination with a polylactic acid resin, the aliphatic polyester resin used in the aliphatic polyester resin composition A is obtained from succinic acid and 1,4-butanediol from the viewpoint of melting point and thermal stability. A succinate-based aliphatic polyester using succinic acid such as polybutylene succinate or polybutylene succinate adipate obtained by copolymerizing adipic acid with polybutylene succinate is preferable.

  As described above, the aliphatic polyester resin composition A of the present invention has a polylactic acid resin content of 30% by weight or more and 100% by weight in 100% by weight of the aliphatic polyester resin composition A from the viewpoint of the strength of the laminated film and the stability over time. It is preferable to contain 0% or more and 70% by weight or less of other aliphatic polyester resins. More preferably, the other aliphatic polyester resin is 0% to 50% by weight, and more preferably 0% to 30% by weight.

  Examples of the plasticizer B used in the present invention include polyester-based, polyether-based, polyamide-based, and polyvinyl-based compounds, and are not particularly limited. Among these, the plasticizer B used in the present invention preferably contains a plasticizer having a polylactic acid segment.

  When plasticizers with polylactic acid segments are used, plasticizer exudation and extraction (bleed out) can strongly suppress problems such as changes in physical properties over time, whitening of the film surface, and contamination of articles to be packaged. As the agent B, it is preferable to use a plasticizer having a polylactic acid segment.

  The addition amount of the plasticizer B used in the present invention preferably satisfies the above-described structural ratio formula, 5 ≦ [100 × B / (A + B)] ≦ 50.

  When the composition ratio [100 × B / (A + B)] is less than 5% by weight, the plasticizer B content is too small, so that sufficient flexibility may not be obtained in the laminated film of the present invention. When the ratio [100 × B / (A + B)] exceeds 50% by weight, the content of the plasticizer B is too large, so that the handleability as a composition or a film is deteriorated and the film is blocked. May occur.

  The plasticizer B used in the present invention preferably has a polylactic acid segment. Here, the polylactic acid segment means a lactic acid block polymer composed of polylactic acid or oligolactic acid. When the plasticizer B has a polylactic acid segment, the polylactic acid segment in the plasticizer is compatible with the aliphatic polyester resin composition A as a base material, in particular, a polylactic acid-based resin. A part of the structure is incorporated into the polylactic acid crystal of the base material, and the anchor effect can suppress bleeding out of the plasticizer B from the laminated film.

  Furthermore, the plasticizer B having such a polylactic acid segment has at least one polylactic acid segment having a weight average molecular weight of 1500 to 10,000 in one molecule from the viewpoint of an anchor effect and a plasticizing effect, and has a weight average. It is particularly preferable to use a plasticizer having a polyether segment and / or a polyester segment having a molecular weight of 1000 to 10,000.

  Here, as the polyether segment, a polyalkylene glycol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, or a segment made of a copolymer of these polyalkylene glycols can be preferably used.

  Furthermore, the polyalkylene glycol segment used as the plasticizer B is a plasticizer B containing a polyethylene glycol component from the viewpoint of the compatibility with the aliphatic polyester resin composition A, particularly the polylactic acid resin, and the adhesion of the laminated film. It is preferable.

  Further, from the viewpoint of the anchor effect and the plastic effect of the plasticizer B, the weight ratio of the polylactic acid segment of the plasticizer B is preferably 5% by weight to 50% by weight with respect to 100% by weight of the plasticizer B. More preferably, it is 20 to 40 weight%.

  When the weight ratio of the polylactic acid segment of the plasticizer B is less than 5% by weight of the entire plasticizer B, it may be difficult to express the anchor effect of the polylactic acid segment, and when it exceeds 50% by weight. The anchor effect is strongly developed, and the plastic effect of the polyether-based segment and / or the polyester-based segment may be lowered.

  In order to suppress bleed-out of the plasticizer B, a method of making the laminated film of the present invention into a uniaxially stretched laminated film or a biaxially stretched laminated film by stretching in at least one direction is more preferable.

  Next, a plasticizer having at least one polylactic acid segment having a weight average molecular weight of 1500 to 10,000 in one molecule and having a polyether segment and / or a polyester segment having a weight average molecular weight of 1,000 to 10,000. An example of the production method of B will be described.

  Prepare polyethylene glycol (PEG) having hydroxyl ends at both ends. The weight average molecular weight (MPEG) of polyethylene glycol (PEG) having hydroxyl groups at both ends is usually calculated from the hydroxyl value determined by a neutralization method or the like in the case of commercially available products. In a system in which lactide wA wt% is added to polyethyleneglycol (PEG) wB wt% having both hydroxyl ends at both ends, polylactic acid segments are obtained by ring-opening addition polymerization and reacting sufficiently at both hydroxyl ends of PEG. -Polyethylene glycol segment-ABA type triblock copolymer covalently bonded to the polylactic acid segment can be obtained. The molecular weight of the polylactic acid segment can be controlled by controlling the addition amount of polyethylene glycol and lactide and the polymerization catalyst and the conditions of the ring-opening addition polymerization, whereby the desired plasticizer B can be obtained.

  When this reaction is sufficiently completed, the weight average molecular weight of one polylactic acid segment of the plasticizer made of this block copolymer can be substantially calculated as (1/2) × (wA / wB) × MPEG. it can. Further, the weight ratio of the polylactic acid segment component to the entire plasticizer can be substantially calculated as 100 × wA / (wA + wB)%. Furthermore, the weight ratio of the plasticizing component excluding the polylactic acid segment component to the entire plasticizer can be substantially calculated as 100 × wB / (wA + wB)%.

  If it is necessary to remove unreacted PEG, unreacted PEG with terminal polylactic acid segment molecular weight less than 1,500, etc., by-products such as lactide oligomers, or impurities, the following purification method Can be applied.

  After the synthesized plasticizer is uniformly dissolved in an appropriate good solvent such as chloroform, an appropriate poor solvent such as a water / methanol mixed solution or diethyl ether is added dropwise.

  Alternatively, precipitation is performed by adding a good solvent solution in a large excess of poor solvent, and the solvent is evaporated after separating the precipitate by centrifugation or filtration.

  The purification method is not limited to the above, and the above operation may be repeated a plurality of times as necessary.

  When a plasticizer of an ABA type triblock copolymer is prepared by the method described above, the molecular weight of one polylactic acid segment of the prepared plasticizer can be obtained by the following method.

Based on a chart obtained by ¹ H-NMR measurement using a deuterated chloroform solution of a plasticizer,
(1/2) × (IPLA × 72) / (IPEG × 44/4) × MPEG
And calculate. However, IPEG is the signal integral intensity derived from hydrogen of the methylene group of the PEG main chain part, and IPLA is the signal integral intensity derived from hydrogen of the methine group of the PLA main chain part. When synthesized under conditions where the reaction rate of lactide at the time of plasticizer synthesis is sufficiently high and almost all lactide undergoes ring-opening addition to the PEG end, it is often based on a chart obtained by ¹ H-NMR measurement. The method described above is preferred.

The laminated film of the present invention has a water vapor permeability of 1000 g / (m ² · day · atm) or less in an environment of 40 ° C. and a humidity of 90% RH in terms of use as a packaging film for storing food containing moisture. It is preferable. From the viewpoint of preventing the packaged item from drying, it is more preferably 300 g / (m ² · day · atm) or less, and still more preferably 50 g / (m ² · day · atm) or less. From the viewpoint of preserving foods and the like, the water vapor permeability is preferably as low as possible, and most preferably 0 g / (m ² · day · atm). However, it is difficult to obtain a laminated film having a water vapor permeability of 0 g / (m ² · day · atm), and the lower limit that can be achieved in practice is considered to be about 1 g / (m ² · day · atm). . In addition, if the water vapor permeability is about 1 g / (m ² · day · atm), the physical properties are sufficient from the point of use for packaging food. From the same viewpoint, if the water vapor permeability exceeds 1000 g / (m ² · day · atm), the drying of the food proceeds in a short time, which is not preferable.

  When the laminated film of the present invention is used as a packaging film typified by a wrap film, the haze is preferably 0% to 10%, more preferably 0% to 5% so that the contents can be easily identified. % Or less, more preferably 0% or more and 3% or less, and particularly preferably 0% or more and 1% or less.

  Needless to say, as a method for adjusting the haze of the film to 0% or more and 10% or less, it is important to enhance the compatibility between the aliphatic polyester resin composition A and the plasticizer B constituting the film. It is important to control the amount and combination of additives such as wax components.

  From the viewpoint of flexibility when the laminated film of the present invention is used for a wrap film, a stretch film, or a bag, the tensile elastic modulus of the film is preferably 100 MPa or more and 1500 MPa or less. When the tensile modulus exceeds 1500 MPa, the flexibility is insufficient and the usability is poor, or when used as a wrap film, the film cannot follow the shape of the package and cannot be sufficiently deformed, so that sufficient adhesion is obtained. Problems such as inability to obtain may occur. Moreover, when the tensile modulus is less than 100 MPa, the release property of the roll-shaped film may be deteriorated, or the film may be insufficient, so that problems may occur in film formation and processing.

  In order to set the tensile modulus to 100 MPa or more and 1500 MPa or less, it is preferable that the laminated film of the present invention is formed into a uniaxially stretched laminated film or a biaxially stretched laminated film by stretching in at least one direction.

  As the resin composition C of the present invention, an antioxidant, an ultraviolet stabilizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering agent, an antistatic agent, as long as the effects of the present invention are not impaired. Various additives such as inorganic fine particles, organic particles, and organic compounds can be added as release agents, antioxidants, ion exchange agents, color pigments, and the like. When these are added, from the viewpoints of transparency and flexibility of the laminated film, 100% by weight of the resin composition C containing the aliphatic polyester resin composition A and the plasticizer B, the aliphatic polyester resin composition A and the plastic film are added. The total of the agent B is 90% by weight or more and 100% by weight or less, and it is preferable that other various additives and the like are included in an amount of 0% by weight or more and 10% by weight or less.

  Similarly, the resin composition D of the present invention is an antioxidant, an ultraviolet stabilizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering agent, and an antistatic agent as long as the effects of the present invention are not impaired. In addition, inorganic fine particles, organic particles, or organic compounds may be added as necessary as a release agent, an antioxidant, an ion exchange agent, or a coloring pigment. When these are added to the resin composition D, the total of the polyvinylidene chloride resin and the polyvinylidene chloride copolymer resin is 100% by weight of the resin composition D containing the polyvinylidene chloride resin and / or the polyvinylidene chloride copolymer resin. It is preferably 90 wt% or more and 100 wt% or less, and preferably contains 0 wt% or more and 10 wt% or less of other various additives.

  Examples of the antioxidant include hindered phenols and hindered amines.

  Color pigments include inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide, cyanine, styrene, phthalocyanine, anthraquinone, perinone, isoindolinone, quinophthalone, and quinocridone. Organic pigments such as thioindigo can be used.

  For the purpose of improving the slipperiness and blocking resistance of the film, when adding inorganic fine particles or organic particles, for example, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, polystyrene Particles such as polymethyl methacrylate and silicone can be used.

  Moreover, it is preferable to use the particle | grains which have the refractive index close | similar to the resin composition C for the particle | grains contained in the resin composition C which comprises the layer X from the point which makes transparency favorable. That is, it is preferable to use particles having a refractive index close to that of the aliphatic polyester resin A as the particles contained in the resin composition C. Moreover, it is preferable to use particles having a refractive index close to that of the resin composition D as the particles contained in the resin composition D constituting the layer Y. That is, the particles contained in the resin composition D are preferably particles having a refractive index close to that of the polyvinylidene chloride resin or the polyvinylidene chloride copolymer resin. In this respect, the particles used in the resin composition C and the resin composition D are more preferably particles such as silica, colloidal silica, and polymethyl methacrylate.

  Further, as the particles used in the laminated film of the present invention, it is preferable to select naturally occurring inorganic particles or biodegradable particles. The average particle diameter is not particularly limited, but is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and most preferably 0.08 to 2 μm.

  Further, in order to improve the water vapor barrier property, flat particles having an irregularity degree (major axis / minor axis) of 5 to 1000 and an average major axis of 0.1 to 10 μm are compared with the resin composition C and the resin composition D. A method of containing 0.01 to 10% by weight can be preferably used.

  From the viewpoint of compatibility between water vapor barrier properties and film transparency, and prevention of cleavage of the film by flat particles, the degree of irregularity is more preferably 5 to 500, and particularly preferably 7 to 100. Further, the average major axis of the flat particles is more preferably 0.3 to 5 μm, and particularly preferably 0.5 to 3 μm. As the flat particles, layered inorganic particles collected from natural minerals can be preferably used.

  Examples of such layered inorganic particles include kaolin, talc, mica, barite, and the like, but talc is particularly preferably used from the viewpoint of water vapor barrier properties.

  Moreover, you may use together the method of containing a wax compound with respect to the resin composition C from the point which improves a water vapor | steam barrier property further. By containing the wax compound, the hydrophilicity of the film is reduced, and when inorganic particles are added, the dispersibility is increased, and a more remarkable water vapor barrier effect can be obtained.

  Examples of the wax compound include carnauba wax, candelilla wax, rice wax, pentaerythritol full ester, behenyl behenate, partyl myristate, stearyl stearate, olefin wax, and the like. Uba wax, candelilla wax, rice wax and the like are particularly preferable.

  The laminated film of the present invention can be obtained by an existing stretched film production method such as inflation, sequential biaxial stretching, and simultaneous biaxial stretching. In the production of a film by a sequential biaxial stretching method or a simultaneous biaxial stretching method, for example, when a two-type three-layer laminated stretched film is used, the resin composition C and the resin composition D are supplied to separate extruders, Although it can be extruded by a known method such as a three-layer T-die die and melt-extruded into a sheet, the temperature of the extruder, polymer piping, die, etc. is preferably 250 ° C. or less, more preferably 240 ° C. or less. 230 ° C. or lower is particularly preferable. Further, the residence time from when the resin composition C and the resin composition D are melted in the extruder to when they are discharged from the die is preferably 20 minutes or less, more preferably 10 minutes or less, and more preferably 5 minutes. The following is more preferable. The extruded sheet-like melt is brought into close contact with a casting drum and cooled and solidified to obtain an unstretched film. The unstretched film obtained by this method is continuously stretched in at least one direction, and then stretched in a direction perpendicular to the first-stage stretching direction as necessary.

  In manufacturing the laminated film of the present invention, in order to suppress the deterioration of the aliphatic polyester resin composition A and the plasticizer B used and the generation of decomposition products, vacuum drying is performed at 80 ° C. to 110 ° C., and the degree of vacuum is 10 Torr or less. It is preferable that the high vacuum is used and the drying time is 6 hours or more.

  When the plasticizer B is added to the aliphatic polyester resin composition A, for example, a blend chip obtained by mixing a master chip of polylactic acid resin containing a high concentration of B and a homochip of an aliphatic polyester resin is formed into a film such as an extruder. It may be melt-kneaded by being fed to the extruder of the machine, but in order to minimize the thermal deterioration of the resin composition and reduce the lactide content, a raw material that has been dried under vacuum is used and a twin-screw extruder is used. The aliphatic polyester resin composition that has been melted in an extruder by use, for example, is preferably melted and kneaded by continuously adding a plasticizer that has been liquefied by heating, for example, if necessary. Further, a method is preferred in which a vent port is provided in the middle of the twin screw extruder, the vent port is decompressed, and melt kneading while removing moisture and low molecular weight components such as oligomers generated during melting.

  The stretching conditions of the film can be adjusted as appropriate according to the desired heat shrinkage characteristics, dimensional stability, strength, elastic modulus, etc., and can be carried out by any method. It is preferable to become. The polylactic acid polymer in the base material is oriented and crystallized by stretching, and at the same time, the B polylactic acid segment is promoted to be incorporated into the oriented crystal, thereby volatilizing, leaching and extracting B (bleed out) ) Is further preferable.

  In addition, crystallization can be promoted while maintaining transparency, and strength physical properties are improved by orientation crystallization, so that a film having both flexibility and strength can be obtained.

  Further, the stretching speed can be appropriately adjusted within a range of 100 to 50000% / min. Further, it is more preferable to perform heat treatment at 100 ° C. or higher for 10 seconds or longer for the purpose of stabilizing the structure of crystals and plasticizer in the film and reducing low molecular weight components such as oligomer components in the film. The heat treatment is preferably carried out at a higher temperature in the range of the glass transition temperature to the melting point of the resin used from the viewpoint of film strength and dimensional stability, and specifically 40 to 90 ° C.

  Further, the heat treatment may be performed by relaxing in the film longitudinal direction and the width direction. When a specific elongation such as a stretch film is required, the draw ratio and heat treatment temperature are preferably adjusted as appropriate. The draw ratio is 1 to 10 times the area magnification, and the heat treatment temperature is 120 ° C. or less and 20 seconds or less. A short heat treatment is preferable.

  The stretching temperature is preferably not less than the glass transition temperature of the resin used and not more than the crystallization temperature in terms of biaxial stretching properties and film transparency. The stretching ratio is 1.1 in the longitudinal direction and the width direction, respectively. The range may be any of 10 to 10 times, and either the longitudinal direction or the width direction may be increased or the same.

  The draw ratio of the film may be adjusted as appropriate according to the intended flexibility, handleability, and productivity. From the viewpoint of transparency, the polylactic acid segment of the plasticizer is promoted to be incorporated into the crystal. More preferably, it is 2 to 8 times, more preferably 2.5 to 8 times in at least one direction. Although it is not particularly limited, when a biaxially stretched film is used, if the stretching ratio in one direction exceeds 10 times, the stretchability is lowered, and the film tends to break during film formation. In some cases, deterioration of the transparency of the film may occur, and in the case of sequential biaxial stretching, the stretchability in the second direction may be reduced, so that it is preferable to adjust appropriately. The area magnification which is the area ratio of the film before and after stretching is preferably 4 to 60 times, more preferably 6 to 40 times, and further preferably 6 to 30 times. From the viewpoint of productivity, a higher draw ratio is preferable.

  The laminated film of the present invention is preferably subjected to surface treatment such as corona discharge treatment or plasma treatment from the viewpoint of enhancing the functionality of the film surface. Further, a different adhesive resin or the like may be coated in the film production in-line or offline, or a metal compound may be deposited and used.

  The laminated film of the present invention is not only excellent in transparency, flexibility and adhesion, but also has excellent water vapor barrier properties, which are important as packaging materials, and can maintain excellent properties by suppressing changes in physical properties over time. Therefore, it can be suitably used as a wrap film, stretch film, bag, or the like.

Although the manufacturing method of the laminated | multilayer film of this invention is specifically illustrated below, the manufacturing method of the film of this invention is not limited to this.
(1) Film thickness According to JIS-B-7509 (established in 1955), the film thickness was measured using a dial gauge thickness gauge.
(2) Thickness of each layer of laminated film Ultrathin slices cut in the cross-sectional direction of the laminated film were prepared, and the thickness of each layer was measured by observing with a transmission electron microscope and taking a photograph.
(3) Water vapor transmission rate [g / (m ² · day · atm)]
The gas barrier property of the laminated film was expressed by substituting the water vapor transmission rate, and the oxygen transmission rate under the conditions of 40 ° C. and humidity 90% RH was measured according to JIS K7129 (established in 1992).
(4) Haze value [%]
The film was measured using a haze meter HGM-2DP type (manufactured by Suga Test Instruments Co., Ltd.). The measurement was performed 5 times per level, and the film haze value [%] was obtained as an average value of the 5 measurements.
(5) Tensile modulus [MPa]
The evaluation film piece had a width of 10 mm and a length of 150 mm, and was previously conditioned for 1 day or more in an atmosphere of a temperature of 23 ° C. and a humidity of 65% RH. These film samples are subjected to a tensile tester manufactured by Orientec Co., Ltd. under the conditions of a measurement temperature of 23 ° C., an initial length of 50 mm, and a tensile speed of 300 mm / min, and other conditions are subjected to a tensile test according to JISZ1702 (established in 1976). The tensile modulus was measured. The measurement was performed 5 times per level, and the average value of 5 tests was obtained and used as the tensile modulus.
(6) Adhesion 3 g of water is put into a ceramic bowl (5 cm in diameter and 3 cm in height), a film is applied, heated in a microwave oven for 2 minutes, taken out of the microwave oven, and cooled at room temperature for 1 hour while being wrapped. After that, the adhesion to the container was determined according to the following criteria.
◯: The center of the film wrapped in the container extends to the inside of the container, and water droplets adhere to the inner surface of the film.
(Triangle | delta): The center part of the film wrapped in the container does not extend to the inner side of the container, but has water droplets attached.
X: The center part of the film wrapped in the container does not extend to the inside of the container, and water droplets do not adhere to the inside.
(7) Change in physical properties with time The film cut into B5 size was allowed to stand for 30 days under constant temperature and humidity conditions of 40 ° C. and humidity of 90% RH.

  For a film that has not been allowed to stand for 30 days (before aging) and a film that has been allowed to stand for 30 days (after aging), the film width direction is the width and the film longitudinal direction is the length, and the width is 10 mm and the length is 150 mm. Each of the film samples cut into 5 samples was prepared, and these film samples were subjected to a tensile tester manufactured by Orientec Co., Ltd., at a measurement temperature of 23 ° C., an initial length of 50 mm, and a tensile speed of 300 mm / min. A tensile test was performed according to (Established in 1976), and the breaking strength (MPa) was measured.

The average value of the elongation at break for each of the 5 samples before and after the change with time was determined as the break strength (MPa) in the longitudinal direction of the film, and determined according to the following criteria.
○: 90 ≦ [100 × (breaking strength after aging) / (breaking strength before aging)] ≦ 100 (%)
Δ: 60 ≦ [100 × (breaking strength after aging) / (breaking strength before aging)] <90 (%)
×: 0 ≦ [100 × (breaking strength after change with time) / (breaking strength before change with time)] <60 (%)
(8) Plasticizer bleed-out property After measuring the weight before treatment of a film sample that has been conditioned for 1 day in an atmosphere of a temperature of 23 ° C. and a humidity of 65% RH in advance, and after treating in a 120 ° C. hot air oven for 30 minutes The humidity was adjusted again under the same conditions as before the treatment, and the weight was measured.

The weight change rate was calculated as a ratio of the weight change (decrease) before and after the treatment to the weight before the treatment, and was determined according to the following criteria.
○: 0 ≦ [100 × (weight reduction after treatment) / (weight before treatment)] ≦ 1.0 (%)
Δ: 1.0 <[100 × (weight loss after treatment) / (weight before treatment)] ≦ 2.0 (%)
×: 2.0 <[100 × (weight reduction after treatment) / (weight before treatment)] (%)
The polylactic acid resin, aliphatic polyester resin, plasticizer and polyvinylidene chloride copolymer resin used in this example were obtained as follows.
(Polylactic acid resin (P1))
As the crystalline polylactic acid resin a, L-polylactic acid (optical purity 99% or higher, melting point 175 ° C., PLA4032D manufactured by NatureWorks) having a weight average molecular weight of about 200,000 was used.
(Polylactic acid resin (P2))
As the non-crystalline polylactic acid resin b, DL-polylactic acid (optical purity 84%, PLA4060D manufactured by NatureWorks) having a weight average molecular weight of about 160,000 was used.
(Aliphatic polyester resin S1)
Polybutylene succinate adipate (Showon Polymer Co., Ltd., Bionore # 3001) was used.
(Plasticizer (B1))
A mixture of 62 parts by weight of polyethylene glycol having a number average molecular weight of 8000, 38 parts by weight of L-lactide and 0.025 parts by weight of tin octylate is polymerized at 150 ° C. for 3 hours in a nitrogen atmosphere, so A plasticizer B1 having a polylactic acid segment having an average molecular weight of 2500 was obtained.
(Plasticizer (B2))
80 parts by weight of polyethylene glycol having a number average molecular weight of 8000, 20 parts by weight of L-lactide, and 0.025 part by weight of tin octylate are mixed and polymerized at 150 ° C. for 3 hours in a nitrogen atmosphere. A plasticizer B2 having a polylactic acid segment having an average molecular weight of 1000 was obtained.
(Plasticizer (B3))
By mixing 40 parts by weight of polyethylene glycol having a number average molecular weight of 4000, 60 parts by weight of L-lactide and 0.025 parts by weight of tin octylate and polymerizing at 150 ° C. for 3 hours in a nitrogen atmosphere, there are a number of both ends of polyethylene glycol. A plasticizer B3 having a polylactic acid segment with an average molecular weight of 3000 was obtained.
(Polyvinylidene chloride copolymer resin (D1))
A commercially available polyvinylidene chloride wrap film (manufactured by Kureha) was cut and melted at 180 ° C., taken out into a strand, cooled and finely cut into pellets.
(Polyester (E1)
To a mixture of 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol, 0.09 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide are added, the temperature is gradually raised, and finally Carried out a transesterification reaction while distilling methanol at 220 ° C., and then 0.020 parts by mass of an 85% aqueous solution of phosphoric acid was added to the transesterification reaction product, and then transferred to a polycondensation reaction kettle. Further, the reaction system was gradually depressurized while being heated and heated, and a polycondensation reaction was performed by a conventional method at 290 ° C. under a reduced pressure of 1 hPa to produce a polyethylene terephthalate resin having an intrinsic viscosity of 0.65.
Example 1
A mixture of 30 parts by weight of polylactic acid (P1), 30 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1) and 20 parts by weight of plasticizer (B1) was subjected to a high vacuum of 10 torr at 100 ° C. for 6 hours. After drying under the above, it was subjected to a twin-screw kneading extruder having a cylinder temperature of 200 ° C., melt-kneaded and homogenized to obtain a chip-formed composition M1. The composition M1 (chip) was further dried at 80 ° C. for 24 hours under a high vacuum of 10 torr and subjected to the following film formation.

The chip of the composition M1 was supplied to a single screw extruder A set at a melting temperature of 200 ° C., and a polyvinylidene chloride copolymer resin D1 was supplied to a single screw extruder B set at a cylinder temperature of 190 ° C. An unstretched film was produced by being guided to a set three-layer T die die, extruded into a film shape, and cast on a drum cooled to 5 ° C. by electrostatic application. At this time, the extrusion amounts of the extruders A and B were adjusted so that B / A / B was 1/18/1. After continuously stretching 3.0 times in the longitudinal direction between heating rolls at 85 ° C., the obtained uniaxially stretched film is gripped with a clip and guided into a tenter, and heated in a temperature of 90 ° C. in the lateral direction. The film was stretched by a factor of 0 and fixed in the width direction, and heat treatment was performed at 110 ° C. for 20 seconds to obtain a laminated film having a thickness of 10 μm. The evaluation results of the obtained film are shown in Table 1.
(Example 2)
Except for obtaining composition M2 using a mixture of 6 parts by weight of polylactic acid (P1), 54 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 1.
(Example 3)
Except for obtaining composition M3 using a mixture of 12 parts by weight of polylactic acid (P1), 12 parts by weight of polylactic acid (P2), 56 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 1.
Example 4
The thickness was as in Example 1 except that composition M4 was obtained using a mixture of 40 parts by weight of polylactic acid (P1), 40 parts by weight of polylactic acid (P2), and 20 parts by weight of plasticizer (B1). A 10 μm laminated film was obtained. The evaluation results of the obtained film are shown in Table 1.
(Example 5)
Except for obtaining composition M5 using a mixture of 35 parts by weight of polylactic acid (P1), 35 parts by weight of polylactic acid (P2), 25 parts by weight of aliphatic polyester (S1), and 5 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 1.
(Example 6)
Except that composition M6 was obtained using a mixture of 15 parts by weight of polylactic acid (P1), 15 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1), and 50 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 1.
(Example 7)
A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that the extrusion amounts of the extruders A and B were adjusted so that B / A / B was 1/38/1. The evaluation results of the obtained film are shown in Table 1.
(Example 8)
A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that the extrusion amounts of the extruders A and B were adjusted so that B / A / B was 1/2/1. The evaluation results of the obtained film are shown in Table 1.
Example 9
Except for obtaining composition M7 using a mixture of 36 parts by weight of polylactic acid (P1), 24 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 2.
(Example 10)
Except for obtaining composition M8 using a mixture of 8 parts by weight of polylactic acid (P1), 8 parts by weight of polylactic acid (P2), 64 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B1). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 2.
(Example 11)
A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that the extrusion amounts of the extruders A and B were adjusted so that B / A / B was 3/2/3. However, as compared with Example 1, the stretchability characteristics were somewhat deteriorated, and the film was somewhat rough. The evaluation results of the obtained film are shown in Table 2.
(Example 12)
Except for obtaining composition M9 using a mixture of 30 parts by weight of polylactic acid (P1), 30 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B2). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 2.
(Example 13)

Except that composition M10 was obtained using a mixture of 30 parts by weight of polylactic acid (P1), 30 parts by weight of polylactic acid (P2), 20 parts by weight of aliphatic polyester (S1), and 20 parts by weight of plasticizer (B3). A laminated film having a thickness of 10 μm was obtained in the same manner as Example 1. The evaluation results of the obtained film are shown in Table 2.
(Example 14)

A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that the extrusion amounts of the extruders A and B were adjusted so that A / B / A was 3/4/3. The evaluation results of the obtained film are shown in Table 2.
(Example 15)

Lead to multi-layer T-die die set at a die temperature of 190 ° C and extrude into a film. Adjust the extrusion amounts of Extruders A and B so that B / A / B / A / B is 2/3/2/3/2 Except that, the same as in Example 1. A laminated film having a thickness of 10 μm was obtained. The evaluation results of the obtained film are shown in Table 2.
(Example 16)
A laminated film having a thickness of 100 μm was obtained in the same manner as in Example 1 except that the film was not stretched. The evaluation results of the obtained film are shown in Table 3.
(Comparative Example 1)
In the same manner as in Example 1, except that composition M12 was obtained using a mixture of 35 parts by weight of polylactic acid (P1), 35 parts by weight of polylactic acid (P2), and 30 parts by weight of aliphatic polyester (S1). A laminated film having a thickness of 10 μm was obtained. The evaluation results of the obtained film are shown in Table 3.
(Comparative Example 2)
A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that the polyvinylidene chloride copolymer resin D1 was not used and a single film of the composition M1 described in Example 1 was used. The evaluation results of the obtained film are shown in Table 3.
(Comparative Example 3)
A laminated film having a thickness of 10 μm was obtained in the same manner as in Example 1 except that polyester E1 was used instead of the composition M1 in Example 1. In addition, the resin layer which consists of polyester E1 is described as the layer Z. The evaluation results of the obtained film are shown in Table 3.

  The laminated film of the present invention can be suitably used as a packaging film for articles such as wrap films, stretch films and bags, and foods.

Claims (11)

  At least a layer X composed of a resin composition C containing an aliphatic polyester resin composition A and a plasticizer B, and a layer Y composed of a resin composition D containing a polyvinylidene chloride resin and / or a polyvinylidene chloride copolymer resin. Two or more laminated films.   2. The laminated film according to claim 1, wherein the aliphatic polyester resin composition A contains a polylactic acid resin in an amount of 30% by weight to 100% by weight. The laminated film according to claim 2, wherein the constituent ratio of the crystalline polylactic acid resin a and the non-crystalline polylactic acid resin b constituting the polylactic acid resin satisfies the following relational expression. .
Composition ratio: 50 ≦ [100 × b / (a + b)] ≦ 90 (% by weight)
In the formula [100 × b / (a + b)] indicating the composition ratio, “a” represents the weight of the crystalline polylactic acid resin “a”, and “b” represents the weight of the amorphous polylactic acid resin “b”. . The laminated film according to claim 1, wherein the constituent ratio of the aliphatic polyester resin composition A and the plasticizer B satisfies the following relational expression.
Composition ratio: 5 ≦ [100 × B / (A + B)] ≦ 50 (% by weight)
In the formula [100 × B / (A + B)] indicating the composition ratio, A represents the weight of the aliphatic polyester resin composition A, and B represents the weight of the plasticizer B.   The plasticizer B has at least one polylactic acid segment having a weight average molecular weight of 1,500 or more in one molecule, and has a polyether-based and / or polyester-based segment. 4. The laminated film according to any one of 4 above.   The laminated film according to claim 5, wherein the weight ratio of the polylactic acid segment of the plasticizer B according to claim 5 is 5% by weight or more and 50% by weight or less of the entire plasticizer B.   Resin composition D is a copolymer of at least one vinyl group-containing monomer selected from polyvinyl chloride, acrylonitrile, vinyl acetate, and (meth) acrylic acid esters, using polyvinylidene chloride resin and / or vinylidene chloride as an essential component. The laminated film according to claim 1, wherein the laminated film is a cured resin composition. The laminated film according to claim 1, wherein the relationship between the thicknesses of the layer X and the layer Y satisfies the following relational expression.
Lamination ratio: 5 ≦ [100 × (total of layer Y) / (total of layer X + total of layer Y)] ≦ 50 (%)
In the formula [100 × (total of layer Y) / (total of layer X + total of layer Y)] indicating the stacking ratio, the total of layer X indicates the total thickness of all layers X in the stacked film, The total of layer Y shall show the total thickness of all the layers Y in a laminated film. The laminated film according to any one of claims 1 to 8, wherein water vapor permeability in an environment of 40 ° C and humidity of 90% RH is 1000 g / (m ² · day · atm) or less.   The laminated film according to any one of claims 1 to 9, which is used for a wrap film, a stretch film, or a bag.   The method for producing a laminated film according to claim 1, wherein the laminated film is stretched in at least one direction.