JP2009013405A - Film, molded article using the film, stretched film, heat shrinkable film, heat shrinkable label, and container with the label attached - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyolefin film excellent in transparency, film appearance, and finish properties and suitable for applications such as packaging, shrink bundling packaging, and shrinkable labels. <P>SOLUTION: The polyolefin film consists of a resin composition mainly comprising a polyolefin resin (A), a polylactic acid resin (B), and a compatibilizer (C) for these resins. The mass ratio between the polyolefin resin (A) and the polylactic acid resin (B), namely (A)/(B), is set at 99/1-70/30, and the compatibilizer (C) is contained in an amount not less than 1 part by mass but not more than 30 parts by mass, relative to 100 parts by mass of the resin mixture of the polyolefin resin (A) and the polylactic acid resin (B). The compatibilizer (C) is composed of a copolymer having a segment (a) formed from an ethylene homopolymer, etc., and segments (b) formed from at least one kind of a vinyl monomer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyolefin-based film, a molded product using the film, a stretched film, a heat-shrinkable film, a heat-shrinkable label, and a container equipped with the molded product or label. More specifically, the present invention relates to a polyolefin-based film having excellent transparency and appearance and having an excellent finish, and suitable for uses such as packaging and shrinkage labels, and a molded article using the film. The present invention relates to a heat-shrinkable film, a heat-shrinkable label, and a container equipped with the molded product or the heat-shrinkable label.

  Conventionally, as a film used as a packaging material, films such as polyester such as polyethylene terephthalate, polyolefin such as polyethylene and polypropylene, and nylon are widely used.

  However, since such a film that has been used conventionally does not decompose in a natural environment or has a very low decomposition rate, when it is left after use or buried in soil, it is semi-permanently There was a problem of remaining in the ground. Moreover, when it is abandoned in the ocean, the landscape is damaged and the living environment of marine life is destroyed. Furthermore, in the case of incineration treatment, waste treatment becomes a social problem along with the expansion of consumption, such as promoting the deterioration of the incinerator due to its high combustion heat.

On the other hand, since polylactic acid is decomposed when discarded in the natural environment and an effect of reducing CO ₂ gas can be expected, a film mainly composed of polylactic acid has been developed as a film material. For example, a laminated film combining a polyolefin-based resin and a polylactic acid-based resin has been reported (see Patent Document 1), and this film contains an outer layer containing a filler in a range of 35 mass% to 80 mass%. Therefore, there is a problem that the stretched film is inferior in transparency and mechanical strength. Furthermore, since the film described in Patent Document 3 has a large number of micropores on the surface of the film, it is inferior in printability, slipperiness, etc., and is unsuitable as a label application for printing.

  On the other hand, a shrink sheet having a layer mainly composed of a polyolefin resin and a layer mainly composed of a polylactic acid resin has also been reported (see Patent Document 2). However, this shrinkable sheet is made by the inflation method for the purpose of shrink-wrapping films such as lunch boxes and side dishes sold at convenience stores, etc., and as a heat-shrinkable label application that requires low-temperature high-shrinkability When used, there is a problem that sufficient low temperature shrinkage cannot be obtained. Furthermore, since this shrinkable sheet is a laminated sheet having a polylactic acid resin layer as a core material and a polyolefin resin layer on both outer layers, it is inferior in sealing properties and solvent resistance when making cylindrical seal bags, There was a problem that it was not suitable for shrinkable label applications. Further, when a recyclable resin generated from trimming loss such as ears of the shrink sheet is added (hereinafter also referred to as “regeneration addition”), light scattering occurs at the interface between the polyolefin resin and the polylactic acid resin. As a result, the transparency of the film is lowered, and there is a problem that good transparency cannot be obtained.

In order to overcome the above-mentioned problems, in the material design in which different materials are combined, a compatibilizing agent that makes them compatible is often used. For example, Patent Document 3 reports a polylactic acid resin composition comprising polylactic acid and a modified olefin compound, and Patent Document 4 also discloses polylactic acid and an aliphatic polyester other than polylactic acid and a modified polyolefin compound. A polylactic acid-based resin composition has been reported. Although these are both excellent in strength and impact resistance and can control the rate of degradation by microorganisms, modified olefin compounds and modified polyolefin compounds containing reactive polar groups such as glycidyl groups and maleic anhydride are used as compatibilizers. Due to the use, problems such as the occurrence of irregularities during production and prototyping, poor appearance, and clogging of the filtration device in the production line have occurred.
JP 2002-347184 A JP 2002-19053 A JP 9-316310 A JP 2001-123055 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is a polyolefin-based film excellent in transparency, appearance, and finish, and suitable for uses such as packaging and shrinkage labels. Is to provide.

  Another object of the present invention is to provide a molded product, a heat-shrinkable film, a heat-shrinkable label, and the molded product or heat-shrinkable product using the polyolefin-based film suitable for applications such as packaging, shrink-bound packaging, and shrinkable labels. It is to provide a container equipped with a sex label.

  As a result of intensive studies on the composition, blending ratio, and processing conditions of the polyolefin-based resin and the polylactic acid-based resin, and the compatibilizer for these resins, the polyolefin-based film that can solve the problems of the conventional technology The present invention was successfully completed.

  That is, the subject of this invention is the resin composition which has as a main component the compatibilizer (C) of polyolefin resin (A), polylactic acid resin (B), and the said resin (A) and the said resin (B). Or a polyolefin film having at least one layer made of this resin composition, wherein the mass ratio (A) / (B) of the polyolefin resin (A) and the polylactic acid resin (B) is 99/1 to 70/30, and the content of the compatibilizer (C) is 1 part by mass or more and 30 parts by mass with respect to 100 parts by mass of the mixed resin of the polyolefin resin (A) and the polylactic acid resin (B). And the compatibilizer (C) is selected from the group consisting of ethylene homopolymers, ethylene copolymers, acid-modified olefin copolymers, olefin thermoplastic elastomers, and styrene thermoplastic elastomers. This Segment (a), it is achieved by a film which is a copolymer having a segment (b) formed from at least one vinyl monomer.

  In the film of the present invention, the resin (A) is preferably a polyethylene resin, a polypropylene resin, or a mixture thereof.

  The film of the present invention preferably contains 5% by mass or more and 50% by mass or less of hydrocarbon resins with respect to the total amount of the polyolefin-based resin (A).

  Moreover, the film of this invention makes the mixed resin layer which has a polyolefin-type resin (A), a polylactic acid-type resin (B), and a compatibilizing agent (C) as a main component into (I) layer, and polylactic acid-type resin (B ) Can be a laminated film having a layer containing (II) as a main component.

  The film of the present invention is also preferably a laminated film having an adhesive layer made of an adhesive resin between the (I) layer and the (II) layer.

  Moreover, when the film of this invention is a laminated | multilayer film, it is preferable that the thickness ratio of the (II) layer with respect to the whole film is 10% or more and 70% or less.

  Another object of the present invention is a stretched film, a heat-shrinkable film, a molded product, a heat-shrinkable label, and a container equipped with the molded product or the heat-shrinkable label using the film of the present invention as a base material. Is achieved.

  According to the present invention, a film excellent in transparency, appearance, and finish can be provided.

  Furthermore, according to the present invention, a stretched film, a heat-shrinkable film, a molded product, and a heat-shrinkable label, which are excellent in transparency, appearance, and finish, are suitable for applications such as packaging, shrink-bound packaging and shrinkage labels. Can be provided. Furthermore, according to this invention, the container equipped with the said molded article or heat-shrinkable label which has a transparent and beautiful external appearance can be provided.

  Hereinafter, the film of the present invention, a stretched film using the film of the present invention, a heat-shrinkable film, a molded product, a heat-shrinkable label, and a container equipped with the molded product or the heat-shrinkable label (hereinafter referred to as “ The stretched film of the present invention "," heat-shrinkable film of the present invention "," molded product of the present invention "," label of the present invention "and" container of the present invention ") will be described in detail.

  In the present specification, “main component” is intended to allow other components to be included as long as the action and effect of the resin constituting each layer is not hindered. Further, the term does not limit the specific content, but it is 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass with respect to the total components of each layer. It is a component occupying the following. Further, in this specification, the “main shrinkage direction” means a direction in which the thermal shrinkage rate is large between the longitudinal direction (longitudinal direction) of the film and the lateral direction (width direction) of the film. Means a direction corresponding to the outer circumferential direction, and “orthogonal direction” means a direction perpendicular to the main contraction direction. Further, in the present specification, the “film” is a thin flat product whose thickness is extremely small compared to the length and width and whose maximum thickness is arbitrarily limited, and is usually provided in the form of a roll. “Sheet” refers to a product that is thin by definition in the Japanese Industrial Standard (JIS), and whose thickness is usually small and flat for the length and width. However, the boundary between the sheet and the film is not clear, and it is not necessary to distinguish both in terms of the wording in the present invention. Therefore, in the present invention, the term “film” includes “sheet”.

[the film]
Does the film of the present invention comprise a resin composition mainly comprising a polyolefin resin (A), a polylactic acid resin (B), and a compatibilizer (C) of the resin (A) and the resin (B)? Alternatively, it has at least one layer made of this resin composition.

<Polyolefin resin (A)>
In the present invention, the polyolefin resin used as the resin (A) is not particularly limited, but a polyethylene resin, a polypropylene resin, or a mixture thereof is used from the viewpoints of heat shrinkage characteristics, mechanical properties, and moldability. It is preferable. Examples of suitable polyethylene resins and polypropylene resins used in the present invention are given below.

As the polyethylene resin preferably used in the present invention, density of 0.940 g / cm ³ or more 0.970 g / cm ³ or less of a high-density polyethylene resin (HDPE), density of 0.920 g / cm ³ or more 0.940 g / cm ³ or less in density polyethylene resin (MDPE), density of 0.920 g / cm ³ less than the low-density polyethylene resin (LDPE) or linear low density polyethylene resin (LLDPE).

The density of the polyethylene resin is 0.800 g / cm ³ or higher, preferably 0.850 g / cm ³ or more, even more preferably 0.900 g / cm ³ or more, 0.945 g / cm ³ or less, preferably is 0.935 g / cm ³ or less, still more preferably in the range of 0.925 g / cm ³ or less. If the density is 0.800 g / cm ³ or more, the waist (rigidity at room temperature) and heat resistance of the entire film are not significantly lowered, which is practically preferable. On the other hand, if the density is 0.945 g / cm ³ or less, the drawability at a low temperature is maintained, and a heat shrinkage rate in a practical temperature range (about 70 ° C. or more and about 90 ° C. or less) can be obtained sufficiently.

  Among the polyethylene resins, linear low density polyethylene resin (LLDPE) is particularly preferably used from the viewpoints of stretchability, impact resistance of the film, transparency, and the like. Examples of the linear low density polyethylene resin (LLDPE) include a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms. Examples of the α-olefin component include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-1-butene, 4 -Methyl-1-pentene and the like are exemplified. Among these, 1-butene, 1-hexene, and 1-octene copolymerized with ethylene are preferably used. Moreover, the α-olefin to be copolymerized may be used alone or in combination of two or more.

  The melt flow rate (MFR) of the polyethylene-based resin is not particularly limited, but usually MFR (JIS K7210, temperature: 190 ° C., load: 21.18 N) is 0.5 g / 10 min or more. Preferably, it is 1.0 g / 10 min or more and 15 g / 10 min or less, preferably 10 g / 10 min or less. The MFR of the polyethylene resin is preferably selected to be similar to the viscosity at the time of melting of the polylactic acid resin in order to obtain a film having a uniform thickness.

  Next, examples of the polypropylene resin include homopropylene resin, random polypropylene resin, block polypropylene resin, ethylene-propylene rubber, ethylene-butene rubber, and ethylene diene rubber. Among these, a random polypropylene resin is particularly preferably used from the viewpoints of stretchability, transparency, rigidity, and the like.

  In the random polypropylene resin, the α-olefin to be copolymerized with propylene is preferably an α-olefin having 2 to 20 carbon atoms, more preferably 4 to 12 carbon atoms. For example, what copolymerized ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene etc. with propylene can be illustrated. In the present invention, from the viewpoints of stretchability, heat shrinkage characteristics, impact resistance, transparency, rigidity, and the like of the film, random polypropylene having an ethylene unit content of 2% by mass to 10% by mass as the α-olefin is particularly preferable. Preferably used. Moreover, you may use the alpha olefin to copolymerize individually by 1 type or in combination of 2 or more types.

  Further, the melt flow rate (MFR) of the polypropylene resin is not particularly limited, but usually MFR (JIS K7210, temperature: 230 ° C., load: 21.18 N) is 0.5 g / 10 min. As described above, it is preferably 1.0 g / 10 min or more, and is desirably 15 g / 10 min or less, preferably 10 g / 10 min or less. The MFR of polypropylene is preferably selected to be similar to the viscosity at the time of melting of the polylactic acid resin in order to obtain a film having a uniform thickness.

  The production method of the polyolefin-based resin (A) is not particularly limited. For example, a known polymerization method using a known olefin polymerization catalyst, for example, a multisite catalyst represented by a Ziegler-Natta type catalyst or a metallocene. Examples thereof include a slurry polymerization method, a solution polymerization method, a bulk polymerization method, and a gas phase polymerization method using a single site catalyst typified by a system catalyst, and a bulk polymerization method using a radical initiator.

  When using 2 or more types of polyolefin resin as a polyolefin resin (A), a compounding ratio is suitably determined in consideration of the glass transition temperature (Tg), melting | fusing point, viscoelasticity value, etc. of the mixed resin after a mixing | blending. For example, when the polyolefin resin (A) is a mixed resin of a polyethylene resin and a polypropylene resin, the blending ratio (A1 / A2) of the polyethylene resin (A1) and the polypropylene resin (A2) is in the range of 90/10 to 10/90. The range of 80/20 to 20/80 is preferable, and the range of 70/30 to 30/70 is more preferable.

  In the present invention, the polyolefin resin (A) is, for example, a trade name “Novatech HD, LD, LL”, “Kernel”, “Toughmer A, P” (manufactured by Nippon Polyethylene), “Suntech HD, LD” as a polyethylene resin. (Manufactured by Asahi Kasei Chemicals), "HIZEX" "ULTZEX" "EVOLUE" (manufactured by Mitsui Chemicals), "UBE polyethylene" "UMERIT" (manufactured by Ube Industries), "NUC polyethylene" "Nacflex" (manufactured by Nippon Unica) ), “Engage” (manufactured by Dow Chemical Co., Ltd.) and the like can be used. Examples of the polypropylene resin include “Novatech PP”, “WINTEC”, “Toughmer XR” (manufactured by Nippon Polypro), “Mitsui Polypro” (manufactured by Mitsui Chemicals), “Sumitomo Noblen”, “Tough Selenium”, “Excellen EPX”. ”(Manufactured by Sumitomo Chemical Co., Ltd.),“ IDEMITSU PP ”,“ IDEMITSU TPO ”(manufactured by Idemitsu Kosan Co., Ltd.),“ Adflex ”,“ Adsyl ”(manufactured by Sun Allomer),“ VERSIFY ”(manufactured by Dow Chemical Co., Ltd.) Goods can be used.

Moreover, as the polyolefin resin (A) used in the present invention, a polyolefin resin having a crystallization heat amount ΔHc of 40 J / g or less can be suitably used from the viewpoint of transparency. When such a polyolefin-based resin is mixed with the polylactic acid-based resin (B), the difference in refractive index between the two resins can be reduced and excellent transparency can be maintained. From the viewpoint of further improving the transparency, the heat of crystallization of the polyolefin resin (A) is preferably 30 J / g or less, more preferably 25 J / g or less, and further preferably 20 J / g or less. preferable. A non-crystalline polyolefin resin that does not express the amount of crystallization heat can also be suitably used.
The crystallization heat quantity ΔHc can be measured using a differential scanning calorimeter (DSC). Specifically, the crystallization heat quantity ΔHc is raised to 200 ° C. at a heating rate of 10 ° C./min and held at 200 ° C. for 5 minutes. Then, it can be expressed as the amount of heat when the temperature is lowered to room temperature at a cooling rate of 10 ° C./min.

  Examples of the polyolefin resin (A) include a polyethylene resin, a polypropylene resin, or a mixture thereof having a crystallization heat quantity ΔHc in the above range from the viewpoints of flexibility and transparency, mechanical properties, and moldability. Can do.

  Examples of the polyolefin resin (A) include soft polypropylene (trade name “Versify”) manufactured by Dow Chemical Company.

  In the present invention, the polyolefin resin (A) may further contain hydrocarbon resins. When hydrocarbon resins are included in the polyolefin resin (A), the crystallization of the polyolefin resin (A) (for example, polyethylene resin or polypropylene resin) is suppressed, and the transparency of the film is improved. The stretchability at a low temperature can be maintained, and an improvement in heat shrinkability can be expected.

In the present invention, hydrocarbon resins refer to petroleum resins, terpene resins, rosin resins, and the like. The petroleum resins can be exemplified by aromatic petroleum resins from alicyclic petroleum resins and C ₉ components from cyclopentadiene or dimer thereof. Examples of the terpene resin include terpene resins and terpene-phenol resins from β-pinene. Examples of rosin resins include rosin resins such as gum rosin and wood rosin, and esterified rosin resins modified with glycerin, pentaerythritol, and the like. Hydrocarbon resins are known to exhibit relatively good compatibility when mixed with polyolefin resins and the like, but it is preferable to use a hydrogenated derivative from the viewpoint of color tone, thermal stability, and compatibility. Particularly preferred are hydrogenated petroleum resins and partially hydrogenated petroleum resins.

  Some of the hydrocarbon resins have various softening temperatures depending on the molecular weight. In the present invention, the softening temperature is 100 ° C or higher, preferably 110 ° C or higher, and 150 ° C or lower, preferably 140 ° C or lower. Those are preferably used. When the softening temperature is 100 ° C. or higher, it is practically preferable because it does not bleed to the surface of the sheet when mixed, causing blocking, or lowering the mechanical strength of the entire sheet and being easily broken. On the other hand, if the softening temperature is 150 ° C. or lower, the compatibility with the polyolefin-based resin is favorably maintained, and it is preferable that the film does not bleed on the film surface with time and blocking or transparency is not lowered.

  The content of the hydrocarbon resins is preferably 5% by mass or more of the total amount of the polyolefin resin (A), more preferably 8% by mass or more, still more preferably 10% by mass or more, and 50% by mass or less. The amount is preferably 40% by mass or less, and more preferably 30% by mass or less. Here, if the content of hydrocarbon resins is 5% by mass or more, the effect of improving the transparency and shrinkage property of the film is remarkable, and if it is 50% by mass or less, the surface bleeds over time. It is preferable because problems such as easy blocking of films and reduced impact resistance are unlikely to occur.

  Examples of the hydrocarbon resins include, for example, Mitsui Chemicals, Inc., trade names “Highlets”, “Petrogin”, Arakawa Chemical Industries, Ltd., “Arcon”, Yashara Chemicals, Inc., “Clearon”, Commercial products such as Idemitsu Petrochemical Co., Ltd. trade name “Imabe” and Tonex Co., Ltd. trade name “Escollets” can be used.

<Polylactic acid resin (B)>
Next, the polylactic acid resin (B) will be described. The polylactic acid resin (B) in the present invention is a homopolymer of D-lactic acid or L-lactic acid or a copolymer thereof, and a mixture thereof is also included. More specifically, poly (D-lactic acid) whose structural unit is D-lactic acid, poly (L-lactic acid) whose structural unit is L-lactic acid, and a copolymer of L-lactic acid and D-lactic acid. Poly (DL-lactic acid) or a mixture thereof.

  When the polylactic acid resin (B) used in the present invention is a mixture of D-lactic acid and L-lactic acid, the mixing ratio of D-lactic acid and L-lactic acid is D-lactic acid / L-lactic acid = 99.8. /0.2-75/25 or D-lactic acid / L-lactic acid = 0.2 / 99.8-25 / 75, preferably D-lactic acid / L-lactic acid = 99.5 / More preferably, it is 0.5 to 80/20, or D-lactic acid / L-lactic acid = 0.5 / 99.5 to 20/80. Polylactic acid composed of D-lactic acid alone or L-lactic acid alone exhibits very high crystallinity, has a high melting point, and tends to be excellent in heat resistance and mechanical properties. However, when used as a heat-shrinkable film, it usually involves printing and a bag-making process using a solvent, so that the crystallinity of the constituent material itself can be lowered appropriately in order to improve printability and solvent sealability. Necessary. Moreover, when crystallinity is too high, orientation crystallization advances at the time of extending | stretching, and there exists a tendency for shrinkage | contraction characteristic to fall. From these facts, the mixing ratio of the polylactic acid resin (B) used in the present invention is D-lactic acid / L-lactic acid = 99/1 to 85/15, or D-lactic acid / L-lactic acid = 1/99 to Most preferred is 15/85.

  In the present invention, the polylactic acid resin (B) can be used by mixing copolymers of D-lactic acid and L-lactic acid having different copolymerization ratios. In that case, what is necessary is just to adjust so that the value which averaged the copolymerization ratio of D-lactic acid of a some lactic acid-type polymer and L-lactic acid may enter in the said range. Two or more types of polylactic acid resins having different copolymer ratios of D-lactic acid and L-lactic acid are mixed in accordance with the intended use, and the crystallinity is adjusted to balance heat resistance and heat shrinkage characteristics. be able to.

  The polylactic acid resin (B) used in the present invention may be a copolymer of lactic acid and α-hydroxycarboxylic acid, aliphatic diol, or aliphatic dicarboxylic acid. Here, the “α-hydroxycarboxylic acid” copolymerized with the lactic acid resin includes optical isomers of lactic acid (D-lactic acid for L-lactic acid, and L-lactic acid for D-lactic acid, respectively). Glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methylbutyric acid, Bifunctional aliphatic hydroxy-carboxylic acids such as 2-hydroxycaprolactone acid and lactones such as caprolactone, butyl lactone and valerolactone. Examples of the aliphatic diol copolymerized with the lactic acid resin include ethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the aliphatic dicarboxylic acid to be copolymerized include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. The copolymerization ratio of the copolymer of lactic acid and α-hydroxycarboxylic acid, aliphatic diol, or aliphatic dicarboxylic acid is lactic acid / α-hydroxycarboxylic acid, aliphatic diol, or aliphatic dicarboxylic acid = 90/10 The range is preferably 10/90, more preferably 80/20 to 20/80, and even more preferably 30/70 to 70/30. If the copolymerization ratio is within the above range, a film having a good balance of physical properties such as rigidity, transparency and impact resistance can be obtained.

  The polylactic acid resin (B) can be prepared by a known polymerization method such as a condensation polymerization method or a ring-opening polymerization method. For example, in the case of a condensation polymerization method, a polylactic acid resin having an arbitrary composition can be obtained by directly dehydrating condensation polymerization of D-lactic acid, L-lactic acid, or a mixture thereof. Further, in the ring-opening polymerization method, a lactide which is a cyclic dimer of lactic acid is subjected to ring-opening polymerization in the presence of a predetermined catalyst while using a polymerization regulator or the like, if necessary. A lactic acid resin can be obtained. The lactide includes DL-lactide, which is a dimer of L-lactic acid. By mixing and polymerizing these as required, a polylactic acid resin having an arbitrary composition and crystallinity can be obtained. it can. Furthermore, a small amount of chain extender such as a diisocyanate compound, diepoxy compound, acid anhydride, acid chloride, etc. may be used for the purpose of increasing the molecular weight.

  The polylactic acid resin (B) has a weight (mass) average molecular weight of 20,000 or more, preferably 40,000 or more, more preferably 60,000 or more, and 400,000 or less, preferably 350,000. In the following, it is more desirable that it is 300,000 or less. When the weight (mass) average molecular weight is 20,000 or more, an appropriate resin cohesive force can be obtained, and the film can be prevented from being insufficiently stretched or embrittled. On the other hand, if the weight (mass) average molecular weight is 400,000 or less, the melt viscosity can be lowered, which is preferable from the viewpoint of production and productivity improvement.

  Examples of commercial products of the polylactic acid-based resin include trade names “NatureWorks” (manufactured by NatureWorks LLC), “LACEA” (manufactured by Mitsui Chemicals), “U'z series” (manufactured by Toyota Motor Corporation), and the like. .

  In order to improve impact resistance, rubber components other than the polylactic acid resin (B) can be added to the polylactic acid resin (B) within a range that does not impair transparency and flexibility. The rubber component is not particularly limited, but is an aliphatic polyester other than the polylactic acid resin (B), an aromatic-aliphatic polyester, a copolymer of diol, dicarboxylic acid and lactic acid resin, or a core-shell structure rubber. , And ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene- (meth) acrylic acid copolymer (EMA), An ethylene-methyl (meth) acrylic acid copolymer (EMMA) etc. can be used conveniently.

  Examples of the aliphatic polyester include polyhydroxycarboxylic acids, aliphatic polyesters obtained by condensing aliphatic diols and aliphatic dicarboxylic acids, aliphatic polyesters obtained by ring-opening polymerization of cyclic lactones, and synthetic fatty acids. Group polyester can be used. Examples of the hydroxycarboxylic acid include 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, Examples thereof include homopolymers and copolymers of hydroxycarboxylic acids such as 2-hydroxycaprolacuronic acid.

  As the aliphatic polyester obtained by condensing an aliphatic diol and an aliphatic dicarboxylic acid, one or two or more kinds of aliphatic diols and aliphatic dicarboxylic acids described below are condensed or condensed, Or the polymer which can be obtained as a desired polymer | macromolecule can be mentioned by jumping up molecular weight with an isocyanate compound etc. as needed. Here, examples of the aliphatic diol include ethylene glycol, propylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, and suberin. Examples include acid, sebacic acid, dodecanedioic acid and the like.

  In addition, examples of the aliphatic polyester obtained by ring-opening condensation of cyclic lactones include ring-opening polymers such as ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone, which are cyclic monomers. These cyclic monomers can be copolymerized by selecting not only one kind but also plural kinds.

  Examples of synthetic aliphatic polyesters include copolymers of cyclic acid anhydrides and oxiranes, such as copolymers of succinic anhydride and ethylene oxide, copolymers of propion oxide, and the like. it can.

  Representative examples of aliphatic polyesters other than these polylactic acid resins include the product name “Bionole” (manufactured by Showa Polymer Co., Ltd.) obtained by polymerizing succinic acid, 1,4-butanediol and adipic acid. Can be mentioned. Moreover, as a thing obtained by ring-opening condensation of (epsilon) -caprolactone, a brand name "Cell Green" (made by Daicel Chemical Industries Ltd.) can be mentioned.

  Next, as the aromatic-aliphatic polyester, those having crystallinity lowered by introducing an aromatic ring between the aliphatic chains can be used. The aromatic-aliphatic polyester is obtained, for example, by condensing an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and an aliphatic diol.

  Here, examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid, and terephthalic acid is most preferably used. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and adipic acid is most preferably used. Two or more types of aromatic dicarboxylic acids, aliphatic dicarboxylic acids or aliphatic diols may be used.

  Typical examples of the aromatic aliphatic polyester include a copolymer of tetramethylene adipate and terephthalate, a copolymer of polybutylene adipate and terephthalate, and the like. EsterBio (manufactured by Eastman Chemicals) as a copolymer of tetramethylene adipate and terephthalate, and Ecoflex (manufactured by BASF) as a copolymer of polybutylene adipate and terephthalate can be obtained commercially.

  Examples of the structure of the polylactic acid resin (B), diol and dicarboxylic acid copolymer include random copolymers, block copolymers, and copolymers, and any structure may be used. However, from the viewpoint of impact resistance and transparency, a block copolymer or a copolymer is preferable. A specific example of the random copolymer is a trade name “GS-Pla” (manufactured by Mitsubishi Chemical Corporation), and a specific example of the block copolymer or copolymer is a trade name “Plamate” (Dainippon Ink Chemical Co., Ltd.). Can be mentioned.

  The production method of the copolymer of polylactic acid resin (B), diol and dicarboxylic acid is not particularly limited, but polyester or polyether polyol having a structure obtained by dehydration condensation of diol and dicarboxylic acid is subjected to ring-opening polymerization with lactide. Or the method obtained by making it transesterify is mentioned. Further, there is a method in which a polyester or polyether polyol having a structure obtained by dehydration condensation of a diol and a dicarboxylic acid is obtained by dehydration / deglycolization condensation or transesterification with a polylactic acid resin.

  The copolymer of the polylactic acid resin (B), the diol and the dicarboxylic acid can be adjusted to a predetermined molecular weight using an isocyanate compound, a carboxylic acid anhydride, or the like. However, from the viewpoints of moldability and mechanical properties, the weight (mass) average molecular weight is 50,000 or more, preferably 100,000 or more, and 300,000 or less, preferably 250,000 or less. .

  Further, in addition to the polylactic acid resin (B), a glycerin fatty acid ester may be contained. The glycerin fatty acid ester can play a role of plasticizing the polylactic acid resin (B). The type of glycerin fatty acid ester is not particularly limited. For example, in addition to monoglyceride, diglyceride, triglyceride, acetylated monoglyceride, polyglycerin fatty acid ester such as diglycerin, triglycerin, tetraglycerin, etc. Can be mentioned.

  The molecular weight of the glycerin fatty acid ester is preferably 2,000 or less, and more preferably 1,500 or less, in order to obtain good mixing with the polylactic acid resin (B).

  It is preferable to mix the polylactic acid resin (B) and the glycerin fatty acid ester so that the mass ratio is 90/10 to 60/40. By setting it within the above range, it is possible to suppress the bleed-out in which the glycerin fatty acid ester is transferred to the surface with time and the surface becomes sticky by providing flexibility.

  In the present invention, the mass ratio of the polyolefin resin (A) to the polylactic acid resin (B) is important that the resin (A) / resin (B) is 99/1 to 70/30. Preferably it is 95 / 5-70 / 30, More preferably, it is 90 / 10-70 / 30. By setting the content of the polyolefin resin (A) to 70% by mass or more, a film excellent in impact resistance and shrinkage finish can be obtained. On the other hand, by including 1% by mass or more of the polyolefin-based resin (B), a film having excellent shrinkage characteristics and suppressing natural shrinkage can be obtained.

<Compatibilizer (C)>
In the present invention, the compatibilizing agent (C) is mainly composed of a resin that compatibilizes the polyolefin resin (A) and the polylactic acid resin (B). The compatibilizing agent is not particularly limited as long as it is a resin that compatibilizes the resin (A) and the resin (B), but an ethylene homopolymer, an ethylene copolymer, an acid-modified olefin copolymer, an olefinic resin. A copolymer having a thermoplastic resin segment (a) selected from the group consisting of a thermoplastic elastomer and a styrenic thermoplastic elastomer, and a vinyl polymer segment (b) formed from at least one vinyl monomer. It is preferable to use a polymer.

  The segment (a) of the compatibilizer (C) is selected from the group consisting of ethylene homopolymers, ethylene copolymers, acid-modified olefin copolymers, olefin thermoplastic elastomers, and styrene thermoplastic elastomers. This is a thermoplastic resin segment. These may be used alone or in combination of two or more.

  Examples of the segment of the ethylene homopolymer include segments such as low density polyethylene and high density polyethylene.

  Examples of the ethylene copolymer segment include ethylene-α-olefin copolymer, ethylene-α-olefin-nonconjugated polyene copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-vinyl acetate. Examples include segments such as copolymers.

  Examples of the α-olefin other than ethylene in the ethylene-α-olefin copolymer and the ethylene-α-olefin-nonconjugated polyene copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, Examples include 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 5-methyl-1-hexene. These α-olefins may be used alone or in combination of two or more. Non-conjugated polyenes include 5-ethylidene-2-norbornene (ENB), dicyclopentadiene (DCP), 5-vinyl-2-norbornene, norbornadiene, methyltetrahydroindene (above, cyclic diene), 1,4-hexadiene. 7-methyl-1,6-octadiene (above, chain diene) and 8-methyl-4-ethylidene-1,7-nonadiene, 4-ethylidene-1,7-undecadiene (above, chain triene) Etc.

  Specific examples of the ethylene-α-olefin copolymer segment include segments such as an ethylene-propylene copolymer, an ethylene-butene copolymer, an ethylene-hexene copolymer, and an ethylene-octene copolymer.

  Specific examples of the ethylene-α-olefin-nonconjugated polyene copolymer segment include ethylene-butene-nonconjugated polyene copolymer and ethylene-propylene-nonconjugated polyene copolymer segments. More specifically, an ethylene-propylene-ethylidene norbornene copolymer and an ethylene-propylene-dicyclopentadiene copolymer segment may be mentioned.

  Specific examples of the ethylene- (meth) acrylic acid alkyl ester copolymer segment include ethylene- (meth) methyl acrylate copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) acrylic. Examples thereof include segments such as an acid n-butyl copolymer, an ethylene- (meth) acrylate isobutyl copolymer, and an ethylene- (meth) acrylate 2-ethylhexyl copolymer. In this specification, acrylic and methacryl are collectively referred to as (meth) acrylic.

  Specific examples of the acid-modified olefin copolymer segment include an acid-modified product of ethylene-butene copolymer (maleic anhydride and maleic acid, the same applies hereinafter), an acid-modified product of ethylene-propylene copolymer, Acid-modified product of ethylene-hexene copolymer, acid-modified product of ethylene-octene copolymer, acid-modified product of ethylene-butene-nonconjugated polyene copolymer, acid modification of ethylene-propylene-nonconjugated polyene copolymer And segments such as ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer, and ethylene-ethyl acrylate-acrylic acid copolymer.

  Specific examples of the olefinic thermoplastic elastomer segment include a mixture of polypropylene and ethylene-propylene copolymer or a cross-linked product thereof, a mixture of polyethylene and ethylene-propylene copolymer or a cross-linked product thereof, and polypropylene and ethylene-propylene. A mixture of non-conjugated polyene copolymer or a cross-linked product thereof, a mixture of polyethylene and ethylene-propylene-non-conjugated polyene copolymer or a cross-linked product thereof, and a hydrogenated product (SEBS) of polypropylene and a styrene-butadiene block copolymer Or a cross-linked product thereof, a mixture of polypropylene and ethylene-1-octene copolymer or a cross-linked product thereof, a mixture of polyethylene and ethylene-1-octene copolymer or a cross-linked product thereof. Crosslinking is performed by a known method, and among them, crosslinking with an organic peroxide is preferable.

  Specific examples of the segment of the styrenic thermoplastic elastomer include styrene-butadiene rubber (SBR) or a hydrogenated product thereof (H-SBR), a styrene-butadiene block copolymer (SBS) or a hydrogenated product thereof (SEBS), Segments such as styrene-isoprene block copolymer (SIS) or its hydrogenated product (SEPS, HV-SIS), styrene- (butadiene / isoprene) block copolymer, styrene- (butadiene / isoprene) random copolymer Can be mentioned.

  Among these segments (a), the ethylene copolymer, olefin thermoplastic elastomer, and styrene thermoplastic elastomer segments are excellent in mechanical properties and are preferably used. Furthermore, when mixed with the component (A), a co-continuous structure can be obtained relatively easily by adjusting the mass ratio, melt viscosity, etc., and the mechanical properties are also good. As the segment (a) of the solubilizer (C), an ethylene copolymer segment is preferably used, and in particular, an ethylene- (meth) acrylic acid alkyl ester copolymer or an ethylene-vinyl acetate copolymer segment. Is most preferably used.

  The segment (b) of the compatibilizer (C) is a segment composed of at least one vinyl polymer. Here, the vinyl monomer that forms a segment made of a vinyl polymer is a (meth) acrylic acid alkyl ester having an alkyl chain length of 1 to 20 carbon atoms, a vinyl monomer having an acid group, a hydroxyl group. A vinyl monomer having an epoxy group, a vinyl monomer having a cyano group, and at least one monomer selected from styrene. In this specification, acrylic and methacryl are collectively referred to as (meth) acrylic.

  More specifically, this vinyl monomer includes methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylate-2-ethylhexyl acrylate, (Meth) acrylic acid lauryl, (meth) acrylic acid stearyl, (meth) acrylic acid, maleic acid, maleic anhydride, (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, Meta) Glycidyl acrylate and the like. Among these, since compatibility with the polylactic acid-based resin (B) is relatively good, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid , 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and glycidyl (meth) acrylate are preferred. Furthermore, since a co-continuous structure can be obtained relatively easily by adjusting the mixing ratio and melt viscosity when mixed with the polylactic acid-based resin (B), the segment of the compatibilizing agent (C) of the present invention ( As b), methyl (meth) acrylate is most preferably used.

  Examples of the copolymer structure of the compatibilizing agent (C) include block copolymers, alternating copolymers, random copolymers, and graft copolymers. The constituent segments (a) and (b) The block copolymer and the random copolymer in which the molecular chain ends are connected to each other in a state where the segment (a) and the segment (b) are covalently bonded to each other. It is localized at the phase interface between the compatible polyolefin resin (A) and the polylactic acid resin (B), and acts as a surfactant between the polyolefin resin (A) phase and the polylactic acid resin (B) phase, It is preferable to reduce the free energy of the interface and increase the thickness of the interface because the formation of large aggregates can be suppressed. In particular, the graft copolymer has a comb structure having the segment (a) as a trunk component and the segment (b) as a branch component, and therefore, compared with the block copolymer, the polyolefin resin (A) phase and the polylactic acid. Since the resin (B) phase hardly penetrates after entering the phase interface and easily adheres to the phase interface, the effect of stabilizing the dispersed phase is high and preferable.

  When the compatibilizer (C) is a graft copolymer, the mass average molecular weight of the vinyl polymer forming the segment (b) [measured by gel permeation chromatograph (GPC) in tetrahydrofuran (THF) in terms of styrene Value] is usually in the range of 1,000 to 2,000,000, preferably 5,000 to 1,200,000. If the mass average molecular weight is less than 1,000, the heat resistance of the graft copolymer tends to decrease, and if the mass average molecular weight exceeds 2,000,000, the melt viscosity of the graft copolymer increases. The moldability tends to decrease.

  In the compatibilizer (C), the segment (a) is usually 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, 99% by mass or less, preferably 95% by mass or less, Preferably, it consists of 90% by mass or less, and the segment (b) is usually 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, 95% by mass or less, preferably 90% by mass or less, More preferably, it is 80 mass% or less. If the segment (a) is 5% by mass or more or the segment (b) is 95% by mass or less, the dispersibility of the compatibilizing agent (C) in the polylactic acid resin (B) is not deteriorated and is good. A molded article having a good appearance can be obtained. On the other hand, if the segment (a) is 99% by mass or less or the segment (b) is 1% by mass or more, a sufficient improvement effect on the polylactic acid resin (B) can be obtained. Based on such knowledge, the interaction between the polylactic acid resin and the graft copolymer is adjusted by changing the polarity of the graft copolymer by adjusting the ratio of the segment (a) and the segment (b). be able to.

  The melt flow rate (MFR) or melt index (MI) of the compatibilizer (C) is preferably 0.01 g / 10 min or more, more preferably 0.1 g / 10 min or more, and further preferably 1.0 g / 10. Min. Or more, 500 g / 10 min or less, preferably 300 g / 10 min or less, more preferably 200 g / 10 min or less. This MFR is measured under the conditions of a resin temperature of 230 ° C. and a measurement load of 21.18 N in accordance with a method defined in JIS7210. If MFR is in the range of 0.01 g / 10 min or more and 500 g / 10 min or less, good affinity between the compatibilizer (C) and the polylactic acid resin (B) can be obtained.

  When two or more resins are used as the compatibilizer (C), they are blended in consideration of the compatibility between the polyolefin resin (A) and the polylactic acid resin (B), the transparency of the mixed resin, the viscoelasticity value, etc. The ratio can be adjusted. For example, hydrogenated products of the above graft copolymers, copolymers of modified styrene-aromatic hydrocarbons and conjugated diene hydrocarbons, copolymers of aromatic vinyl hydrocarbons and conjugated diene hydrocarbons Alternatively, a copolymer having a polar group introduced therein can be used as the mixed resin. When two or more compatibilizers are used, it is preferable because the compatibility effect between the polyolefin resin (A) and the polylactic acid resin (B) is further promoted and the transparency of the film is improved.

  The polymerization method for producing the compatibilizing agent (C) may be any generally known chain transfer method, ionizing radiation irradiation method, etc., but the polymer constituting the segment (a) A monomer (monomer) constituting (b), a specific radical (co) polymerizable organic peroxide, a specific radical polymerization initiator are added, and the segment (b) monomer is added to the segment (a) polymer. Thus, the production method for the grafting reaction by kneading is simple, the grafting efficiency is high, the secondary aggregation of the segment (b) due to heat does not occur, and the compatibilizer (C) is used as the polylactic acid resin (B). Mixing is easy and the interaction between the two is excellent, which is preferable.

  As a commercial item of said graft copolymer, brand name "Modiper" (made by NOF Corporation), "Reseda" (made by Toa Gosei Co., Ltd.), etc. are mentioned, for example.

  The mixing amount of the compatibilizing agent (C) is 1 part by mass or more, preferably 2 parts by mass or more, more preferably 3 parts per 100 parts by mass of the mixed resin of the polyolefin resin (A) and the polylactic acid resin (B). It is desirable that it is at least 30 parts by mass, preferably at most 25 parts by mass, more preferably at most 20 parts by mass. If the mixing amount of the compatibilizing agent (C) is 1 part by mass or more with respect to 100 parts by mass of the mixed resin, the film can have excellent appearance and impact resistance. On the other hand, the rigidity of a film can be maintained by making content of compatible resin (C) into 30 mass parts or less.

[Laminated film]
The film of the present invention is composed of a layer composed of a film composed of a resin composition mainly composed of a polyolefin resin (A), a polylactic acid resin (B), and a compatibilizer (C), or a resin composition. A layer composed of a film having at least one layer as a layer (I) and a layer containing the polylactic acid resin (B) as a main component as a layer (II) can also be used. By providing the (II) layer containing the polylactic acid resin (B) as a main component, it is possible to improve transparency and heat shrinkage properties and to increase rigidity (waist strength).

  In the case where the (II) layer is provided, in order to improve the impact resistance of the film within the range that does not impair the rigidity (elasticity) of the film, the poly (II) layer constituting the layer (II) is the same as the (I) layer. A rubber component other than the polylactic acid resin can be added to the lactic acid resin (B). Although this rubber component is not particularly limited, aliphatic polyesters other than polylactic acid resins, aromatic-aliphatic polyesters, copolymers of diols, dicarboxylic acids and lactic acid resins, and core-shell structure rubbers are suitable. Can be used for

  Examples of the aliphatic polyester include polyhydroxycarboxylic acid, aliphatic polyester obtained by condensing aliphatic diol and aliphatic dicarboxylic acid, aliphatic polyester obtained by ring-opening polymerization of cyclic lactone, and synthetic system Examples include aliphatic polyester. Examples of the hydroxycarboxylic acid include 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, A homopolymer or copolymer of hydroxycarboxylic acid such as 2-hydroxycaprolacuronic acid can be used.

  As the aliphatic polyester obtained by condensing an aliphatic diol and an aliphatic dicarboxylic acid, one or two or more kinds of aliphatic polyesters and aliphatic dicarboxylic acids described below are condensed or condensed, Alternatively, a polymer that can be obtained as a desired polymer by jumping up the molecular weight with an isocyanate compound or the like, if necessary, can be mentioned. Here, examples of the aliphatic diol include ethylene glycol, propylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, and suberin. Acid, sebacic acid, dodecanedioic acid and the like.

  In addition, examples of the aliphatic polyester obtained by ring-opening condensation of cyclic lactones include ring-opening polymers such as ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone, which are cyclic monomers. These cyclic monomers can be copolymerized by selecting not only one kind but also plural kinds.

  Examples of synthetic aliphatic polyesters include copolymers of cyclic acid anhydrides and oxiranes, such as copolymers of succinic anhydride and ethylene oxide, copolymers of propion oxide, and the like. it can.

  Typical aliphatic polyesters other than these polylactic acid resins (B) include “Bionole” (manufactured by Showa Polymer Co., Ltd.) obtained by polymerizing succinic acid, 1,4-butanediol and adipic acid. Can be obtained commercially. Moreover, as a thing obtained by ring-opening condensation of (epsilon) -caprolactone, "Cell Green" (made by Daicel Chemical Industries Ltd.) is mentioned.

  Next, as the aromatic-aliphatic polyester, those having crystallinity lowered by introducing an aromatic ring between the aliphatic chains can be used. The aromatic-aliphatic polyester is obtained, for example, by condensing an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and an aliphatic diol.

  Here, examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid, and terephthalic acid is most preferably used. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and adipic acid is most preferably used. Two or more types of aromatic dicarboxylic acids, aliphatic dicarboxylic acids or aliphatic diols may be used.

  Typical examples of the aromatic aliphatic polyester include a copolymer of tetramethylene adipate and terephthalate, a copolymer of polybutylene adipate and terephthalate, and the like. EsterBio (manufactured by Eastman Chemicals) as a copolymer of tetramethylene adipate and terephthalate, and Ecoflex (manufactured by BASF) as a copolymer of polybutylene adipate and terephthalate can be obtained commercially.

  Examples of the structure of the polylactic acid resin (B), diol and dicarboxylic acid copolymer include random copolymers, block copolymers, and graft copolymers, and any structure may be used. However, a block copolymer or a graft copolymer is preferable from the viewpoint of impact resistance and transparency of the film. A specific example of the random copolymer is “GS-Pla” (Mitsubishi Chemical Co., Ltd.), and a specific example of the block copolymer or graft copolymer is “Plamate” (Dainippon Ink Chemical Co., Ltd.). Is mentioned.

  The production method of the copolymer of polylactic acid resin, diol and dicarboxylic acid is not particularly limited, but polyester or polyether polyol having a structure obtained by dehydration condensation of diol and dicarboxylic acid is converted to lactide and ring-opening polymerization or transesterification. The method obtained by letting it be mentioned. Further, there is a method in which a polyester or polyether polyol having a structure obtained by dehydration condensation of a diol and a dicarboxylic acid is obtained by dehydration / deglycolization condensation or transesterification with a polylactic acid resin.

  The copolymer of polylactic acid resin (B), diol and dicarboxylic acid can be manually adjusted to a predetermined molecular weight using an isocyanate compound or a carboxylic acid anhydride. However, from the viewpoint of workability and mechanical properties, the weight (mass) average molecular weight is 50,000 or more, preferably 100,000 or more, and 300,000 or less, preferably 250,000 or less.

  Examples of the core-shell structure rubber include diene-based core-shell type polymers such as (meth) acrylic acid-butadiene copolymer and acrylonitrile-butadiene-styrene copolymer, and (meth) acrylic acid-styrene-acrylonitrile copolymer. Silicone core-shell type copolymers such as acrylic core-shell type polymers, silicone- (meth) acrylic acid-methyl (meth) acrylate copolymers, silicone- (meth) acrylic acid-acrylonitrile-styrene copolymers, etc. It is done. Of these, a silicone- (meth) acrylic acid- (meth) acrylate methyl copolymer having good compatibility with the polylactic acid-based resin (B) and having a good balance between impact resistance and transparency of the film is more preferable. Used for.

  Specifically, “Metablene” (manufactured by Mitsubishi Rayon Co., Ltd.), “Kane Ace” (manufactured by Kaneka Corporation), etc. are commercially available.

  The amount of the rubber component added is 100 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin (B) contained as the main component of the (II) layer. It is preferable that By making the addition amount of the rubber component 100 parts by mass or less, the film can be suitably used as a heat shrinkable label without impairing the rigidity and transparency of the film. Moreover, favorable impact resistance can be imparted to the film by setting the addition amount of the rubber component to 10 parts by mass or more, preferably 15 parts by mass or more, and more preferably 20 parts by mass or more.

  Further, the (II) layer may contain a (meth) acrylic resin for the purpose of improving the transparency of the film. The (meth) acrylic resin referred to here means a methyl methacrylate homopolymer or a copolymer of methyl methacrylate and another vinyl monomer. Examples of the vinyl monomer include methacrylic acid esters such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate; Acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate; methacrylic acid, acrylic acid Unsaturated acids such as styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like. In addition, copolymers of methyl methacrylate and other vinyl monomers include polybutadiene, butadiene / butyl acrylate copolymers, elastomer components such as polybutyl acrylate copolymers, glutaric anhydride units, and glutarimide. Units may be further included. Among them, from the viewpoint of rigidity and moldability, polymethyl methacrylate resin (PMMA), which is a homopolymer of methyl methacrylate, and methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, acrylic A copolymer composed of two or more selected from acid butyl, acrylic acid, and methacrylic acid is preferably used.

  The (meth) acrylic resin has a weight (mass) average molecular weight of 20,000 or more, preferably 40,000 or more, more preferably 60,000 or more, and an upper limit of 400,000 or less, preferably 350,000. Hereinafter, it is more preferably 300,000 or less. When the weight (mass) average molecular weight is 20,000 or more, it is possible to prevent the film from being insufficiently stretched or embrittled. On the other hand, if the weight (mass) average molecular weight is 400,000 or less, the melt viscosity can be lowered, which is preferable from the viewpoint of production and productivity improvement.

  Commercially available products of the (meth) acrylic resin include, for example, “Sumipex” (manufactured by Sumitomo Chemical Co., Ltd.), “Acrypet” (manufactured by Mitsubishi Rayon Co., Ltd.), “Parapet” (manufactured by Kuraray Co., Ltd.), “Artugrass” (Atofina -Made by Japan), "Delpet" (made by Asahi Kasei) and the like.

  Content with respect to the polylactic acid-type resin (B) of the said (meth) acrylic-type resin shall be in the range of polylactic acid-type resin (B) / (meth) acrylic-type resin = 95 / 5-50 / 50 by mass ratio. It is preferable. If the content of the (meth) acrylic resin in the (II) layer is 5% by mass or more with respect to the total mass of the polylactic acid resin (B) and the (meth) acrylic resin, the shrinkage characteristics and shrinkage of the film The effect of improving finish and transparency can be sufficiently obtained. On the other hand, if the content of the (meth) acrylic resin is 50% by mass or less with respect to the total mass of both resins, the impact resistance of the film is not significantly lowered, and the stretchability at a low temperature can be maintained. The heat shrinkage rate in the practical temperature range (about 70 to 90 ° C.) can be sufficiently obtained. From these facts, the mixed resin in the front and back layers is a polylactic acid resin (B) / (meth) acrylic resin = 90 / by mass ratio of the above-mentioned polylactic acid resin (B) and (meth) acrylic resin. It is more preferable to mix within the range of 10-60 / 40.

The film of the present invention comprises a (I) layer composed of a mixed resin of a polyolefin resin (A), a polylactic acid resin (B) and a compatibilizer (C), and a polylactic acid resin (B) as main components. An adhesive layer may be further provided for the purpose of improving adhesiveness between the (II) layer. The resin constituting the adhesive layer is not particularly limited as long as it is a resin that can exhibit adhesiveness, but at least one selected from the group consisting of the following (ad-1), (ad-2), and (ad-3) A copolymer or a resin composition is preferably used.
(Ad-1) Aromatic vinyl hydrocarbon-conjugated diene copolymer, hydrogenated aromatic vinyl hydrocarbon-conjugated diene copolymer, and aromatic vinyl hydrocarbon-conjugated diene copolymer or hydrogen thereof Resin compound in which polar group is introduced into additive (ad-2) ethylene monomer unit, vinyl acetate, (meth) acrylic acid, ethyl (meth) acrylate, methyl (meth) acrylic acid, maleic anhydride, ( A copolymer comprising one unit selected from the group consisting of glycidyl acrylate (hereinafter referred to as “ethylene copolymer”).
(Ad-3) Modified polyolefin resin

First, a copolymer of an aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated derivative (ad-1) of these copolymers will be described.
As the aromatic hydrocarbon, styrene is preferably used, and styrene homologues such as α-methylstyrene can also be used. As conjugated diene hydrocarbons, 1,3-butadiene, 1,4-butadiene, 1,2-isoprene, 1,4-isoprene, 1,3-pentadiene, etc. are used, and these are hydrogenated derivatives. There may be. These may be used alone or in admixture of two or more.

  In the copolymer of the aromatic hydrocarbon and conjugated diene hydrocarbon or the hydrogenated derivative thereof, the content of the aromatic hydrocarbon is preferably 5 based on the mass of the entire copolymer (100% by mass). It is at least 7 mass%, more preferably at least 7 mass%, even more preferably at least 10 mass%, and preferably at most 50 mass%, more preferably at most 40 mass%, still more preferably at most 35 mass%.

  As a hydrogenated derivative of a copolymer of an aromatic hydrocarbon and a conjugated diene hydrocarbon, a hydrogenated derivative of a styrene-conjugated diene copolymer can be preferably used. The detailed contents of the hydrogenated derivative of the styrene-conjugated diene copolymer and the production method thereof are disclosed in JP-A-2-15843, JP-A-2-305814, and JP-A-3-72512. ing.

  As the aromatic hydrocarbon-conjugated diene hydrocarbon copolymer, each of the above-exemplified copolymers can be used alone or in admixture of two or more. When two or more kinds are mixed and used, the blending ratio is adjusted so that the content of the aromatic hydrocarbon is within the above range as the whole mixed resin.

  Commercially available products of aromatic hydrocarbon-conjugated diene hydrocarbon copolymer include styrene-butadiene block copolymer, trade name “Tufprene” (manufactured by Asahi Kasei Chemical Co., Ltd.), trade name “Asaflex” (Asahi Kasei Chemical) As a hydrogenated derivative of styrene-butadiene block copolymer, trade name “Tuftec H” (manufactured by Asahi Kasei Chemicals), trade name “Clayton G” (manufactured by Kraton Japan), styrene-butadiene random copolymer As a hydrogenated derivative, the product name “Dynalon” (manufactured by JSR), and as a hydrogenated derivative of a styrene-isoprene block copolymer, the product name “Septon” (manufactured by Kuraray), a styrene-vinylisoprene block copolymer elastomer. The product name “Hiblar” (manufactured by Kuraray Co., Ltd.) and the like.

  Examples of the polar group introduced into the copolymer of aromatic hydrocarbon and conjugated diene hydrocarbon or a hydrogenated derivative thereof include maleic anhydride-modified SEBS, maleic anhydride-modified SEPS, epoxy-modified SEBS, A typical example is epoxy-modified SEPS. These copolymers can be used alone or in admixture of two or more. When acid modification is performed with maleic anhydride, the amount of maleic anhydride modification is 0.5% by mass or more, preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and 5.0% by mass. % Or less, preferably 4.0% by mass or less, more preferably 3.0% by mass or less. If the amount of maleic anhydride modification is within the above range, good peeling strength can be maintained without causing the problem of delamination.

  Specifically, trade names “Tuftec M” (manufactured by Asahi Kasei Chemicals), “Epofriend” (manufactured by Daicel Chemical Industries), etc. are commercially available.

  Next, the ethylene copolymer (ad-2) will be described. Examples of the ethylene copolymer include ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene- (meth) acrylic acid copolymer (EMA), and ethylene- ( (Meth) ethyl acrylate copolymer (EEA), ethylene-methyl (meth) acrylic acid copolymer (EMMA), ethylene-vinyl acetate-maleic anhydride terpolymer, ethylene-ethyl acrylate-maleic anhydride Examples include terpolymers, ethylene-glycidyl methacrylate copolymers, ethylene-vinyl acetate-glycidyl methacrylate terpolymers, and ethylene-ethyl acrylate-glycidyl methacrylate terpolymers. Among them, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene- (meth) acrylic acid copolymer (EMA), An ethylene-methyl (meth) acrylic acid copolymer (EMMA) can be suitably used.

  The ethylene copolymer has an ethylene monomer unit content of 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass or more, and 95% by mass or less, preferably 90% by mass or less. More preferably, the content is 85% by mass or less. If the content of the ethylene monomer unit is 95% by mass or less, the flexibility can be sufficiently maintained, and when a stress is applied to the film, a buffering action to the stress generated between the outer layer and the inner layer works. Delamination at room temperature can be suppressed.

  As the ethylene-based copolymer, those having an MFR (JIS K7210, temperature: 190 ° C., load: 21.2 N) of 0.1 g / 10 min or more and 10 g / 10 min or less are suitably used. When the MFR is 0.1 g / 10 min or more, the extrudability can be maintained satisfactorily. On the other hand, when the MFR is 10 g / 10 min or less, the thickness unevenness of the laminated film and the mechanical strength are hardly lowered, which is preferable.

  Examples of commercially available ethylene copolymers include ethylene-vinyl acetate copolymer, trade name “Evaflex EV40LX” (Mitsui / DuPont Polychemical Co.), and ethylene-acrylic acid copolymer, trade name “ NUC copolymer ”(manufactured by Nihon Unicar),“ Evaflex-EEA ”(manufactured by Mitsui DuPont Polychemical),“ Lex Pearl EAA ”(manufactured by Nippon Polyethylene), ethylene- (meth) acrylic acid copolymer, Trade name “Elvalloy” (Mitsui / DuPont Polychemical Co., Ltd.), “Lex Pearl EMA” (Nihon Polyethylene Co., Ltd.), Ethylene-ethyl acrylate copolymer, Trade Name “Lex Pearl EEA” (Nihon Polyethylene Co., Ltd.) As an ethylene-methyl (meth) acrylic acid copolymer, the trade name “ACRIFT”, (Sumitomo Trade name), ethylene-vinyl acetate-maleic anhydride terpolymer, trade name “Bondaine” (manufactured by Sumitomo Chemical Co., Ltd.), ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate tri Examples of the original copolymer, ethylene-ethyl acrylate-glycidyl methacrylate terpolymer include trade name “bond first” (manufactured by Sumitomo Chemical Co., Ltd.).

  Next, the modified polyolefin resin (ad-3) will be described. In the present invention, the modified polyolefin resin refers to a resin mainly composed of an unsaturated carboxylic acid or an anhydride thereof, or a polyolefin modified with a silane coupling agent. Examples of unsaturated carboxylic acids or anhydrides include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, itaconic anhydride, or monoepoxy compounds of these derivatives and the above acids. Ester compounds of the above, and a reaction product of a polymer having a group capable of reacting with these acids in the molecule and an acid. These metal salts can also be used. Among these, maleic anhydride is more preferably used. Moreover, these copolymers can be used individually or in mixture of 2 or more types, respectively.

  Examples of the silane coupling agent include vinyltriethoxysilane, methacryloyloxytrimethoxysilane, and γ-methacryloyloxypropyltriacetyloxysilane.

  In order to produce the modified polyolefin resin, for example, these modified monomers can be copolymerized in the stage of polymerizing the polymer in advance, or these modified monomers can be graft-copolymerized to the polymer once polymerized. In the modification, these modifying monomers are used alone or in combination, and those having a content in the range of 0.1% by mass or more and 5% by mass or less are preferably used. Of these, those that have been graft-modified are preferably used.

  Specifically, trade names “Admer” (Mitsui Chemicals), “Modic” (Mitsubishi Chemical) and the like are commercially available.

  The copolymer or resin of (ad-1), (ad-2) and (ad-3) can be used alone or in admixture of two or more, and (ad-1) and (ad -2) or a mixed resin composition of (ad-1) and (ad-3). Specifically, there is a peak of loss tangent (tan δ) calculated from the ratio of storage elastic modulus to loss elastic modulus near or below normal temperature, and there are soft aromatic hydrocarbons and conjugated diene hydrocarbons. Mixing of a copolymer or a hydrogenated product thereof with a copolymer of a hard aromatic hydrocarbon and a conjugated diene hydrocarbon having a storage elastic modulus (E ′) at 50 to 100 ° C. of 100 Mpa or more More preferably, it is a resin composition. Copolymer of the soft aromatic hydrocarbon and conjugated diene hydrocarbon in the mixed resin composition, or the co-weight of the hydrogenated product thereof and the hard aromatic hydrocarbon and conjugated diene hydrocarbon The mixing ratio of the coalescence is preferably 80/20, more preferably 40/60, and further preferably 30/70. When the mixing ratio is in the above range, the heat resistance of the adhesive layer is improved by the copolymer of the hard aromatic hydrocarbon and the conjugated diene hydrocarbon, and the outer layer and the inner layer of the laminated film are peeled off at a high temperature. And practically preferred. In addition, as the mixing ratio of the copolymer of the soft aromatic hydrocarbon and the conjugated diene hydrocarbon or the hydrogenated product thereof decreases, the peel strength at room temperature decreases, The (I) layer and the (II) layer are not peeled off due to rubbing between films during transportation or scratching by a human nail or the like, and the necessary adhesive strength can be maintained practically.

  When the (II) layer and the adhesive layer are provided in the present invention, the thickness ratio of each layer may be set in consideration of the above-described effects, and is not particularly limited. The thickness ratio of the (II) layer to the total thickness of the film is 10% or more, preferably 15% or more, more preferably 20%, and 70% or less, preferably 60% or less, more preferably 50% or less. It is desirable. Further, the adhesive layer desirably has a function of 0.5 μm or more, preferably 0.75 μm or more, more preferably 1 μm or more, and 6 μm or less, preferably 5 μm or less. If the thickness ratio of each layer is within the above range, a film suitable for applications such as packaging excellent in transparency and finish, shrink-bound packaging, and shrink labels can be obtained in a well-balanced manner.

  The film of the present invention may have at least one printed layer. The printing layer is preferably provided on one surface of the laminated film. In the case of a laminated film, it is preferably provided on the surface of the (II) layer from the viewpoint of improving the followability and solvent resistance of the printed layer during processing. The printed layer is not particularly limited, but in the case of a heat-shrinkable label, which will be described later, when it is applied to the surface on the inner side (that is, the adherend side) when mounted on a container or the like, The print layer is preferred since it does not peel off or become dirty. Moreover, when the transparency of the laminated film is inferior, it is preferably provided on the outer side (that is, the side opposite to the adherend side) from the viewpoint of decorativeness. Furthermore, it may be provided on both surfaces of the heat-shrinkable film.

  The print layer is a layer displaying a product name, an illustration, handling precautions, and the like, and can be formed by a conventional printing method such as gravure printing or flexographic printing. The printing ink used for forming the printing layer is made of, for example, a pigment, a binder resin, a solvent, and other additives. Although it does not specifically limit as said binder resin, For example, resin, such as an acrylic type, a urethane type, a polyamide type, a vinyl chloride-vinyl acetate copolymer type, a cellulose type, a nitrocellulose type, can be used individually or in combination. As the pigment, white pigments such as titanium oxide (titanium dioxide), indigo pigments such as copper phthalocyanine blue, carbon black, aluminum flakes, mica (mica), and other colored pigments can be selected and used in accordance with the application. In addition, extender pigments such as alumina, calcium carbonate, barium sulfate, silica, and acrylic beads can also be used as pigments for the purpose of adjusting gloss. Examples of the solvent include organic solvents such as methyl ethyl ketone, ethyl acetate, methyl alcohol, ethyl alcohol, and isopropyl alcohol, gravure such as water, and flexographic printing ink, and the compatibility and dispersion of each component in the coating agent. Those usually used for the purpose of improving the properties can be used.

  The print layer varies depending on the application and is not particularly limited, but may be a resin layer curable with active energy rays such as visible light, ultraviolet rays, and electron beams. In the case of an active energy ray-curable printing layer, in addition to the above, a photopolymerization initiator such as a photo radical polymerization initiator and a photo cationic polymerization initiator, a sensitizer, etc. should be added to the printing ink. Is preferred.

  The laminated film of the present invention can be provided with, for example, a coating layer, an anchor coat layer, a primer coat layer, an adhesive layer, and the like in addition to the (I) layer, the (II) layer, and the printed layer. A layer such as paper or a metal thin film may be provided as necessary.

  The film or laminated film of the present invention is a resin that constitutes each layer as an addition amount within a range that does not significantly impair the effects of the present invention, in addition to the above-described components, with respect to any one layer or two or more layers of the above respective layers. 0.001 parts by mass or more, preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and 10 parts by mass or less, preferably 5 parts or less, more preferably 100 parts by mass or more. Is within the range of 1 part by mass or less, with the aim of improving and adjusting the physical properties of the moldability, productivity and heat shrinkable film, recycled resin, silica, talc, kaolin generated from trimming loss etc. of film ears , Inorganic particles such as calcium carbonate, pigments such as titanium oxide and carbon black, flame retardants, weathering stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, bridges Agents, lubricants, nucleating agents, can be added a plasticizer, an additive such as antioxidant as appropriate.

<Application>
The film or laminated film of the present invention can be suitably used as a stretched film because the tensile strength and impact strength are increased by stretching. Moreover, it can also be used as a heat-shrinkable film by adjusting the heat setting temperature after stretching. In addition, it can be suitably used for various molded products.

[Heat shrinkable film]
When the film or laminated film of the present invention is used as a heat-shrinkable film, it is important that the heat shrinkage rate when immersed in warm water at 80 ° C. for 10 seconds is 20% or more in at least one direction.

  This is an index for determining the adaptability to the shrinking process in a relatively short time (several seconds to about several tens of seconds) such as the use of shrinkage labels for PET bottles. For example, the required shrinkage rate required for a heat-shrinkable film applied to the use of shrinkage labels for PET bottles varies depending on the shape, but is generally about 20% to 70%.

  Further, the shrinkage processing machine that is most commonly used industrially for label mounting of PET bottles is generally called a steam shrinker that uses steam as a heating medium for shrinking. The heat-shrinkable film needs to sufficiently heat-shrink at a temperature as low as possible from the viewpoint of the influence of heat on the object to be coated. Furthermore, with the recent increase in the speed of the labeling process, there has been an increasing demand for shrinking quickly at a lower temperature. Considering such industrial productivity, it is preferable that the thermal shrinkage rate under the above conditions is 20% or more because it can sufficiently adhere to the object to be coated within the shrinkage processing time. From these facts, the heat shrinkage rate when immersed in warm water at 80 ° C. for 10 seconds is at least one direction, usually 20% or more in the main shrinkage direction, preferably 30% or more, more preferably 40% or more, The upper limit is 85% or less, preferably 80% or less, and more preferably 75% or less.

  In the heat-shrinkable film of the present invention, in order to adjust the heat shrinkage rate when immersed in warm water at 80 ° C. for 10 seconds to the above range, the resin composition is adjusted as described in the present invention and stretched. It is preferable to adjust the temperature to a range described later. For example, when it is desired to further increase the heat shrinkage rate, the composition ratio of the polylactic acid resin (B) constituting the film is increased, the stretching ratio is increased, the stretching temperature is decreased, and the polylactic acid resin (B). It is preferable to use a means such as providing a (II) layer containing as a main component.

<The manufacturing method of each film of this invention>
The film, laminated film, stretched film, and heat-shrinkable film of the present invention (hereinafter referred to as “each film obtained in the present invention”) can be produced by a known method. The form of the film may be either flat or tube-like, but the flat form is preferable in terms of productivity (a few products can be taken in the width direction of the original film) and printing on the inner surface. . As a method for producing a flat film, when producing a single layer film, for example, a method of melting a resin using an extruder, extruding from a T-die, and cooling and solidifying with a chilled roll can be mentioned. Moreover, when manufacturing the laminated | multilayer film, the method of melt | dissolving resin using a some extruder, co-extruding from T-die, and cooling and solidifying with a chilled roll is mentioned, for example. In the case of stretching, the above cooled and solidified single layer or laminated film is heated as necessary, then roll-stretched in the vertical direction, tenter-stretched in the horizontal direction, annealed, cooled, and ( When printing is performed, a method of obtaining a film by subjecting the surface to corona discharge treatment and winding with a winder) can be exemplified. Moreover, the method of cutting open the film manufactured by the tubular method and making it flat is also applicable.

  In the case of a stretched film or a heat-shrinkable film, the stretching ratio is 2 times or more, preferably 3 times or more, and 10 times or less, preferably 6 times for applications such as overlap for shrinkage in two directions. The horizontal direction is 2 times or more, preferably 3 times or more, and 10 times or less, preferably 6 times or less. On the other hand, in applications such as heat-shrinkable labels that shrink mainly in one direction, the direction corresponding to the main shrinkage direction is 2 to 10 times, preferably 4 to 8 times, and the direction orthogonal to it is 1 or more times. It is desirable to select a magnification ratio that is not more than 2 times (1 time indicates that the film is not stretched), preferably 1.1 times or more and 1.5 times or less, which is substantially in the category of uniaxial stretching. A biaxially stretched film stretched at a stretch ratio within the above range does not have an excessively large thermal shrinkage rate in the direction orthogonal to the main shrinkage direction.For example, when used as a shrinkage label, It is preferable because the so-called vertical shrinkage phenomenon, in which the film is thermally contracted in the vertical direction, can be suppressed.

  The stretching temperature needs to be changed depending on the glass transition temperature of the resin to be used and the properties required for the stretched film or heat-shrinkable film, but is generally 50 ° C. or higher, preferably 60 ° C. or higher, and the upper limit is 130 ° C. or lower, preferably Is controlled within a range of 110 ° C. or less. Next, the stretched film is subjected to a heat treatment or relaxation treatment at a temperature of about 50 ° C. or more and 100 ° C. or less for the purpose of reducing the natural shrinkage rate or improving the heat shrink property, if necessary. It cools rapidly within the time not to relax, and becomes a heat-shrinkable film.

  Each film obtained in the present invention is subjected to surface treatment and surface treatment such as corona treatment, printing, coating, and vapor deposition as necessary, and further bag making processing and perforation processing using various solvents and heat sealing. Can do.

  Each film obtained in the present invention is processed from a flat shape to a cylindrical shape or the like by a packaged object and provided for packaging. When printing is required in a cylindrical container such as a plastic bottle, first print the required image on one side of a wide flat film wound up on a roll, and then cut it to the required width while the print side is inside. The center seal (the shape of the seal portion is a so-called envelope) may be folded into a cylindrical shape. As the center sealing method, an organic solvent bonding method, a heat sealing method, an adhesive method, and an impulse sealer method can be considered. Among these, from the viewpoint of productivity and appearance, an adhesion method using an organic solvent is preferably used.

[Molded products, heat-shrinkable labels and containers]
Each film obtained in the present invention is excellent in low-temperature shrinkage, shrink finish, transparency, natural shrinkage, etc. of the film, and its use is not particularly limited. By forming a vapor deposition layer and other functional layers, it can be used as various molded products such as bottles (blow bottles), trays, lunch boxes, prepared food containers, and dairy products containers. In particular, when the film of the present invention is used as a heat-shrinkable label or molded article for food containers (for example, PET bottles, glass bottles, preferably PET bottles for soft drinks or foods), a complicated shape (for example, a narrow center) Even if it is a cylinder, a square column with a corner, a pentagonal column, a hexagonal column, etc., it is possible to obtain a container fitted with a beautiful label or molded product without wrinkles or avatars. The molded article and container of the present invention can be produced by using a normal molding method.

  Each film obtained by the present invention, especially the heat-shrinkable film of the present invention, has excellent shrinkage properties and shrinkage finishing properties. , Materials having extremely different coefficients of thermal expansion and water absorption from the heat-shrinkable film of the present invention, such as polyolefin resins such as metal, porcelain, glass, paper, polyethylene, polypropylene, polybutene, polymethacrylate resins, polycarbonate Can be suitably used as a heat-shrinkable label material for a package (container) using at least one selected from polyester resins such as polyethylene resins, polyethylene terephthalate, and polybutylene terephthalate, and polyamide resins as constituent materials.

  Examples of the material constituting the plastic package in which the heat-shrinkable film of the present invention can be used include polystyrene, rubber-modified impact-resistant polystyrene (HIPS), styrene-butyl acrylate copolymer, styrene-acrylonitrile copolymer, in addition to the above-mentioned resins. Polymer, styrene-maleic anhydride copolymer, acrylonitrile-butadiene-styrene copolymer (ABS), (meth) acrylic acid-butadiene-styrene copolymer (MBS), polyvinyl chloride resin, phenol resin, urea Examples thereof include resins, melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. These plastic packages may be a mixture of two or more resins or a laminate.

Hereinafter, the present invention will be described in detail with reference to examples.
In addition, the measured value and evaluation which are shown to an Example were performed as follows. In the examples, the film take-up (flow) direction is described as MD, and the perpendicular direction thereof as TD.

(1) Heat shrinkage rate The film was cut into a size of MD 100 mm and TD 100 mm, marked with 100 mm intervals in the main shrinkage direction (TD), immersed in a hot water bath at 80 ° C. for 10 seconds, and then cooled at 23 ° C. for 30 seconds. The marked line interval (A) after being immersed in was measured, and the shrinkage was calculated by the following formula (1).
Thermal contraction rate (%) = 100 × (100−A) / 100... Formula (1)

(2) Film appearance The appearance of the obtained film was evaluated according to the following criteria.
A: There are almost no spots on the film and the appearance is good.
○: There are some spots on the film, but there is no practical problem.
X: The spots of a film are intense and the external appearance is remarkably bad.

(3) Transparency According to JIS K7105, the haze value of the film was measured at a film thickness of 50 μm and evaluated as x for more than 12%, ◯ for more than 7% and not more than 12%, and ◎ for not more than 7%.

Example 1
As shown in Table 1, linear low density polyethylene manufactured by Ube Industries, Ltd., trade name “Umerit 0540F” (hereinafter abbreviated as “PO1”) 50% by mass, polypropylene manufactured by Sumitomo Chemical Co., Ltd., trade name “Nobrene FH3315” ”(Hereinafter abbreviated as“ PO2 ”) 34% by mass, hydrogenated petroleum resin manufactured by Arakawa Chemical Co., Ltd., trade name“ Alcon P125 ”(hereinafter abbreviated as“ A1 ”) 15% by mass, manufactured by NatureWorks Nippon Oil & Fats Co., Ltd. with respect to 100 parts by mass of a mixed resin composition comprising polylactic acid, trade name “NatureWorks NW4060D” (L-form / D-form = 88/12) (hereinafter abbreviated as “PLA1”) Ethylene-ethyl acrylate-methyl methacrylate graft copolymer, trade name “Modiper A5200” (hereinafter abbreviated as “C1”) 10 The unstretched film of 50 micrometers in thickness was obtained by mix | blending a mass part, knead | mixing with the twin-screw extruder set to 210 degreeC preset temperature, extruding | pulling, taking up with a 30 degreeC cast roll, and cooling and solidifying. The results of evaluating the obtained film are shown in Table 1.

(Example 2)
For the composition of the resin composition used in Example 1, PO1 is 45% by mass, PO2 is 35% by mass, A1 is 15% by mass, and PLA1 is 5% by mass with respect to 100 parts by mass of the mixed resin composition. An unstretched film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that 10 parts by mass of C1 was blended. The results of evaluating the obtained film are shown in Table 1.

(Example 3)
The composition of the resin composition used in Example 1 is 45% by mass of PO2, polypropylene manufactured by Dow Chemical Co., Ltd., trade name “Versify 2400” (hereinafter abbreviated as “PO3”), 45% by mass, and PLA1. An unstretched film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that 5 parts by mass of C1 was blended with 100 parts by mass of the mixed resin composition consisting of 10% by mass. The results of evaluating the obtained film are shown in Table 1.

Example 4
The composition of the resin composition used in Example 1 is 5 parts by mass of C1 with respect to 100 parts by mass of the mixed resin composition comprising 40% by mass of PO2, 40% by mass of PO3, and 20% by mass of PLA1. An unstretched film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that. The results of evaluating the obtained film are shown in Table 1.

(Example 5)
The composition of the resin composition used in Example 1 is 5 parts by mass of C1 with respect to 100 parts by mass of the mixed resin composition comprising 37% by mass of PO2, 37% by mass of PO3, and 26% by mass of PLA1. An unstretched film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that. The results of evaluating the obtained film are shown in Table 1.

(Example 6)
As shown in Table 1, as the resin constituting the (I) layer, PO1 is 45% by mass, PO2 is 32% by mass, A1 is 15% by mass, PLA1 is 5% by mass, polylactic acid manufactured by Mitsui Chemicals, Inc. Name “Lacia H440” (L-form / D-form = 95.75 / 4.25) (hereinafter abbreviated as “PLA2”), 2% by mass, soft polylactic acid resin manufactured by Dainippon Ink & Chemicals, Inc., trade name 2 parts by mass of C1 is blended with 100 parts by mass of a mixed resin composition consisting of 1% by mass of “Plamate PD-150” (hereinafter abbreviated as “PLA3”), and kneaded with a twin screw extruder. Using the pelletized resin, the resin constituting the (II) layer was mixed with 60% by mass of PLA1, 30% by mass of PLA2, and 10% by mass of PLA3, kneaded with a twin screw extruder, and pelletized. Use a resin that constitutes the adhesive layer , 30% by mass of a styrene-vinylisoprene block copolymer elastomer “HIBLER 7125” (manufactured by Kuraray Co., Ltd., SIS hydrogenated product; hereinafter abbreviated as “AD1”), and a styrene-butadiene block copolymer (styrene / butadiene = 82/18 (mass%), storage elastic modulus E ′ (0 ° C.): 1.44 × 10 ⁹ Pa, peak temperature of loss elastic modulus E ″: −84 ° C., 200 ° C., MFR at 49 N load = 6. 8 g / 10 min; hereinafter referred to as “AD2”) 70% by mass were mixed, kneaded with a twin screw extruder, and pelletized, and each of the three single screw extruders manufactured by Mitsubishi Heavy Industries, Ltd. After melt-mixing the resin at a set temperature of 210 ° C., the thickness of each layer is (II) layer / adhesive layer / (I) layer / adhesive layer / (II) layer = 30 μm / 5 μm / 180 μm / 5 μm / 30 μm From 5 layers dice Extruded, taken up at a cast roll of 50 ° C., allowed to cool and solidified to obtain an unstretched laminated sheet with a thickness of 250 [mu] m. Next, the film is stretched 5.0 times in the transverse uniaxial direction at a preheating temperature of 80 ° C. and a stretching temperature of 75 ° C. using a film tenter manufactured by Kyoto Machine Co., Ltd., followed by heat treatment at 84 ° C., and a heat-shrinkable laminated film having a thickness of 50 μm. Got. The results of evaluating the obtained film are shown in Table 1.

(Example 7)
(I) The composition of the resin composition used in the layer is 40% by mass of PO1, 30% by mass of PO2, 12% by mass of A1, 11% by mass of PLA1, 5% by mass of PLA2, and 2% by mass of PLA3. 2 parts by mass of C1 with respect to 100 parts by mass of the mixed resin composition consisting of: unstretched laminate by the same method as in Example 6 except that the mixture was kneaded with a twin screw extruder and pelletized. A sheet was obtained. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 1.

(Example 8)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 1 part by mass of C1 and 1 part by mass of a modified styrene resin, trade name “Dynalon 8630P” (manufactured by JSR, hereinafter abbreviated as “C2”) are mixed with 100 parts by mass of the mixed resin composition. An unstretched laminated sheet was obtained in the same manner as in Example 6 except that the one kneaded by a twin screw extruder and pelletized was used. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 1.

Example 9
(I) The composition of the resin composition used in the layer is 40% by mass of PO1, 30% by mass of PO2, 12% by mass of A1, 11% by mass of PLA1, 5% by mass of PLA2, and 2% by mass of PLA3. Example 1 except that 1 part by mass of C1 and 1 part by mass of C2 are mixed with 100 parts by mass of the mixed resin composition and kneaded and pelletized using a twin-screw extruder. An unstretched laminated sheet was obtained by this method. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 1.

(Comparative Example 1)
(I) The composition of the resin composition used in the layer is the same as in Example 1 except that a mixed resin composition comprising 45% by mass of PO2, 45% by mass of PO3, and 10% by mass of PLA1 is used. Thus, an unstretched film having a thickness of 50 μm was obtained. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 2)
(I) The same procedure as in Example 1 except that the composition of the resin composition used in the layer is changed to a mixed resin composition comprising 40% by mass of PO2, 40% by mass of PO3, and 20% by mass of PLA1. Thus, an unstretched film having a thickness of 50 μm was obtained. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 3)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. An unstretched laminated sheet was obtained in the same manner as in Example 6 except that the mixture was changed to a mixed resin composition and kneaded with a twin screw extruder and pelletized. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 4)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 3 parts by mass of C2 with respect to 100 parts by mass of the mixed resin composition consisting of: unstretched laminate by the same method as in Example 6 except that the mixture was kneaded with a twin screw extruder and pelletized. A sheet was obtained. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 5)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 6 parts by mass of C2 with respect to 100 parts by mass of the mixed resin composition consisting of: unstretched laminate by the same method as in Example 6 except that the mixture was kneaded with a twin screw extruder and pelletized. A sheet was obtained. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 6)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 9 parts by mass of C2 with respect to 100 parts by mass of the mixed resin composition comprising, unstretched laminate by the same method as in Example 6 except that the mixture was kneaded with a twin screw extruder and pelletized. A sheet was obtained. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 7)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 3 parts by mass of a modified styrenic resin, trade name “Dynalon 4630P” (manufactured by JSR, hereinafter abbreviated as “C3”) is blended with 100 parts by mass of the mixed resin composition. An unstretched laminated sheet was obtained in the same manner as in Example 6 except that the kneaded and pelletized material was used. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

(Comparative Example 8)
(I) The composition of the resin composition used in the layer is 45% by mass of PO1, 32% by mass of PO2, 15% by mass of A1, 5% by mass of PLA1, 2% by mass of PLA2, and 1% by mass of PLA3. 3 parts by mass of a modified olefin resin, trade name “Admer SF730” (Mitsui Chemicals, Inc., hereinafter abbreviated as “C4”) is mixed with 100 parts by mass of the mixed resin composition consisting of A non-stretched laminated sheet was obtained by the same method as in Example 6 except that the mixture was kneaded and pelletized. Further, this unstretched sheet was stretched in the same manner as in Example 6 to obtain a heat-shrinkable laminated film. The results of evaluating the obtained film are shown in Table 2.

  From Tables 1 and 2, the films of Examples 1 to 9 had good transparency and an excellent appearance, whereas the films of Comparative Examples 1 to 8 had a bad appearance. This shows that the film of the present invention is a film having good transparency and film appearance.

  Since the film of the present invention is a film excellent in transparency and film appearance, and excellent in heat shrink characteristics and shrink finish, it can be used for various applications such as various shrink wrapping, shrink tying, and shrink labels.

Claims (10)

A film comprising a resin composition comprising as a main component a polyolefin resin (A), a polylactic acid resin (B), and a compatibilizer (C) between the resin (A) and the resin (B), or the resin A film having at least one layer made of the composition, wherein the mass ratio (A) / (B) of the polyolefin resin (A) to the polylactic acid resin (B) is 99/1 to 70/30. The content of the compatibilizer (C) is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the mixed resin of the polyolefin resin (A) and the polylactic acid resin (B). A segment (a) wherein (C) is selected from the group consisting of an ethylene homopolymer, an ethylene copolymer, an acid-modified olefin copolymer, an olefin thermoplastic elastomer, and a styrene thermoplastic elastomer; and at least one Film which is a copolymer having a segment formed from a vinyl monomer (b). The film according to claim 1, wherein the polyolefin resin (A) is a polyethylene resin, a polypropylene resin, or a mixture thereof. The film of Claim 1 or 2 containing 5 mass% or more and 50 mass% or less hydrocarbon resins with respect to the total amount of polyolefin resin (A). A laminated film comprising the film according to any one of claims 1 to 3 as a (I) layer and a layer containing a polylactic acid resin (B) as a main component as a (II) layer. The laminated film according to claim 4, wherein the thickness ratio of the (II) layer to the whole film is 10% or more and 70% or less. A stretched film obtained by stretching the film according to any one of claims 1 to 3 or the laminated film according to claim 4 or 5 in at least one direction. The main shrinkage direction of the film when the film according to any one of claims 1 to 3 or the laminated film according to claim 4 or 5 is stretched in at least one direction and immersed in warm water at 80 ° C for 10 seconds. A heat shrinkable film having a heat shrinkage ratio of 20% or more. The film according to any one of claims 1 to 3, the laminated film according to claim 4 or 5, the stretched film according to claim 6, or the heat-shrinkable film according to claim 7 is used as a substrate. Molding. A heat-shrinkable label using the heat-shrinkable film according to claim 7 as a substrate. A container equipped with the molded product according to claim 8 or the heat-shrinkable label according to claim 9.