JP5489878B2 - Heat-shrinkable laminated film, molded product using the film, heat-shrinkable label, and container using or mounting the molded product - Google Patents

Description

  The present invention relates to a heat-shrinkable laminated film, a molded article using the heat-shrinkable laminated film, a heat-shrinkable label, and a container using or wearing the molded article. Heat-shrinkable film suitable for applications such as packaging, shrink-bound packaging and shrinkable labels, and molded products using the heat-shrinkable laminated film, heat-shrinkable labels, and molded products using or mounting this label Related to the container.

  Currently, soft drinks such as juice and alcoholic drinks such as beer are sold in a state of being filled in a container such as a bottle or a plastic bottle. At that time, in order to differentiate from other products and improve the visibility of the products, a heat-shrinkable label printed on the outside of the container is attached. As a material for the heat-shrinkable label, polyvinyl chloride (PVC), polystyrene, aromatic polyester or the like is generally used.

  On the other hand, the effective use of exhaustible resources has recently been emphasized, and the use of renewable resources has become an important issue. At present, the use of plastics made from plant materials is attracting the most attention as a solution. This plant-derived plastic not only uses non-depleted resources, but can save exhaustible resources during plastic production, and also has excellent recyclability.

Among these plant-derived plastics, polylactic acid resins are made from lactic acid obtained by fermentation of starch, can be mass-produced by chemical engineering, and have excellent transparency and rigidity. As an alternative material for polyester (polyethylene terephthalate), it has attracted attention in the field of film packaging materials and injection molding.

  However, when polylactic acid is used as a material for heat-shrinkable labels, it is rigid at room temperature, has low-temperature shrinkability, and has good natural shrinkage, but it is a very brittle material. There is a problem that sometimes contraction spots and wrinkles are likely to occur. In addition, the polylactic acid-based heat-shrinkable film also has a problem that when heated, crystallization proceeds and sufficient heat-shrinkage characteristics cannot be obtained.

  As means for solving the above problem, a film in which the copolymerization ratio of L-lactic acid and D-lactic acid in a polylactic acid resin is adjusted is known (see Patent Document 1). However, although this film can suppress crystallization during heating, the problem of causing spots, wrinkles, and avatars due to rapid shrinkage cannot be sufficiently solved. In addition, attempts have been made to improve shrink finish by adjusting the crystallinity of the polylactic acid resin and further blending an aliphatic polyester resin (see Patent Documents 2 and 3, etc.). However, compared with the polystyrene-based heat-shrinkable film that is currently mainstream, it is still difficult to say that the shrinkage finish is sufficient.

  Furthermore, a stretched film in which a polylactic acid resin having a specific weight average molecular weight and a polymethacrylate resin are blended is known (Patent Document 4). However, this technique is mainly intended to improve the heat resistance and transparency of the polylactic acid-based resin film, and is difficult to apply to the heat-shrinkable film as in the present invention.

  In order to solve the above problem, a heat-shrinkable film containing a polylactic acid resin and an acrylic resin is known (Patent Document 5). However, it is difficult to say that this film still has a sufficient shrink finish compared to a polystyrene heat shrink film, and the acrylic resin is fragile because of the brittleness of the material itself. Insufficient points remained.

  Furthermore, polylactic acid-based resins also have the problem that due to the brittleness of the material itself, sufficient strength cannot be obtained when it is molded into a single sheet or film, making it difficult to put it into practical use. In response to this problem, an aliphatic polyester other than polylactic acid (see Patent Document 6), polycaprolactone (see Patent Document 7), a copolymerized polyolefin such as an ethylene-vinyl acetate copolymer (see Patent Document 8), and the like are included. The method is known. These mainly have the purpose of improving brittleness while maintaining the transparency of the polylactic acid-based resin film, and still have insufficient points for shrink finish.

In particular, in recent years, from the viewpoint of increased environmental awareness and cost, there has been a demand for weight reduction (thinning) of labels used for shrink wrapping, etc. In that case, further improvement of impact resistance in heat shrink films is required. In order to improve impact resistance, there is a demand for a composition in which resin components other than polylactic acid resin are blended, and this is used as a film. When the film is folded, a new problem arises in that significant whitening occurs. This is the current situation.
In particular, in heat-shrinkable films, there are many opportunities for the film to be bent, such as in bag making processes and film mounting processes, and as a result, appearance defects and design properties are reduced. There is a need for a heat shrinkable film of resin.

JP 2003-119367 A JP 2001-011214 A JP 2000-280342 A Japanese Patent Laying-Open No. 2005-036054 JP 2006-316137 A JP 09-169896 A Japanese Patent Laid-Open No. 08-300481 JP 09-151310 A

  As described above, the conventional polylactic acid-based heat-shrinkable film cannot sufficiently satisfy all of the heat-shrinkage characteristics, transparency, bending whitening resistance, impact resistance, and shrinkage finish properties. What we had was desired.

  The object of the present invention is based on plant-derived raw materials, has excellent heat shrinkage properties, transparency, resistance to bending whitening, impact resistance, and shrink finish, and is suitable for applications such as shrink wrapping, shrink tying wrapping, and shrink labels. Another object of the present invention is to provide a heat shrinkable laminated film.

  Another subject of the present invention is a molded product using the heat-shrinkable laminated film suitable for uses such as shrink wrapping, shrink-bound packaging and shrinkage label, a heat-shrinkable label, and the molded product, or It is to provide a container equipped with a heat-shrinkable label.

  As a result of intensive investigations in view of the above circumstances, the present inventors have found that the above-mentioned problems can be solved by making a film containing a specific component in polylactic acid into a laminated film, and to complete the present invention. Arrived.

That is, the gist of the present invention resides in the following [1] to [7].
[1] A laminated film comprising at least two layers comprising a composition containing a polylactic acid resin (A) and a core-shell type rubber (B), wherein the film comprises a polylactic acid resin (A) and a core-shell type A resin containing 3 to 12% by mass of the core-shell type rubber (B) in a total mass of 100% by mass of the polylactic acid resin (A) and the core-shell type rubber (B). (I) layer which consists of a composition, The said polylactic acid-type resin (A ') and the said core-shell type rubber (B') are contained, The said polylactic acid-type resin (A ') and the said core-shell type rubber (B') ) And the core-shell type rubber (B ′) in a layer of 5 to 30% by mass of the resin composition (II), and the laminated film is stretched in at least one direction, And the main yield when immersed in warm water at 80 ° C for 10 seconds Heat-shrinkable laminated film, wherein the direction of the heat shrinkage rate is 30 to 70%.

[2] The core-shell rubber (B) or (B ′) has a core layer having a polymer containing an acrylate ester and a polymer containing an acrylate ester having a chemical structure different from the acrylate ester. The heat-shrinkable laminated film according to the above [1], which is a polymer composed of a shell layer.
[3] The above-mentioned [1] or [2], wherein the film has a thickness of 20 to 40 μm, a haze value of 8% or less, and a hydroshot value of 980 N · mm or more. Heat shrinkable laminated film.
[4] Mass (100 mass) of a resin composition comprising at least three layers composed of a composition containing a polylactic acid resin (A) and a core-shell type rubber (B), and constituting an intermediate layer %) Of the core-shell type rubber is larger than the content of the core-shell type rubber based on the mass (100% by mass) of the resin composition constituting the front and back layers. Is a heat-shrinkable laminated film characterized by having a heat shrinkage ratio in the main shrinkage direction of 30 to 70% when stretched in at least one direction and immersed in warm water at 80 ° C. for 10 seconds.
[5] A molded product having the heat-shrinkable laminated film according to any one of [1] to [4] as a base material.
[6] A heat-shrinkable label having the heat-shrinkable laminated film according to any one of [1] to [ 4 ] as a base material.
[7] A container using the molded article according to [5] or equipped with the heat-shrinkable label according to [6].

  According to the present invention, the main component is a plant-derived raw material, and it has excellent heat shrinkage properties, transparency, resistance to bending whitening, impact resistance and shrinkage finish, and is suitable for applications such as shrink wrapping, shrink tying wrapping and shrinkage labels. A heat-shrinkable laminated film can be provided.

  Furthermore, according to the present invention, a molded product using the heat-shrinkable laminated film suitable for uses such as shrink-wrapping, shrink-bound packaging, and shrink-label, a heat-shrinkable label and the molded product, or heat-shrinkable A container fitted with a label can be provided.

  Hereinafter, the heat-shrinkable laminated film, molded product, heat-shrinkable label, and container according to the present invention (hereinafter referred to as “the film of the present invention”, “the molded product of the present invention”, “the label of the present invention”, “ The container of the present invention will be described in detail.

[Film of the present invention]
A first embodiment of the present invention contains a polylactic acid resin (A) and a core-shell type rubber (B), and the total mass of the polylactic acid resin (A) and the core-shell type rubber (B) is In 100% by mass, the core-shell type rubber (B) is composed of 3 to 12% by mass of a resin composition (I) layer, the polylactic acid resin (A ′) and the core-shell type rubber (B ′). Containing 5 to 30% by mass of the core-shell type rubber (B ′) in a total mass of 100% by mass of the polylactic acid resin (A ′) and the core-shell type rubber (B ′). The layer (II) is a laminated film having at least two layers, wherein the laminated film is stretched in at least one direction and immersed in warm water at 80 ° C. for 10 seconds, and has a thermal shrinkage rate in the main shrinkage direction. 30% to 70% heat-shrinkable laminated film It is a film.

Polylactic acid resin (component A / component A ')
The polylactic acid-based resin that is the component (A) or the component (A ′) (hereinafter sometimes collectively referred to as the component (A)) is a homopolymer of D-lactic acid or L-lactic acid, or a combination thereof. A polymer, 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 combination of L-lactic acid and D-lactic acid. There is poly (DL-lactic acid) which is a polymer, and a mixed resin of these copolymers is also included.
In the present invention, the component (A) in the (I) layer and the component (A ′) in the (II) layer may be the same or different.

  The copolymer of L-lactic acid and D-lactic acid has a constitutional ratio of D-lactic acid to L-lactic acid (hereinafter abbreviated as “D / L ratio”) of 1/99 to 25/75, Or 75/25 to 99/1, preferably 3/97 to 20/80, or more preferably 80/20 to 97/3, 5/95 to 15/85, or 85/15 to More preferably, it is 95/5.

  When the D / L ratio is 0/100 or 100/0, very high crystallinity is exhibited, the melting point is high, and heat resistance and mechanical properties tend to be excellent. However, when it is used as a heat-shrinkable film, it usually involves printing and a bag making process using a solvent. Therefore, in order to improve the printability and the solvent sealability, the crystallinity of the constituent material itself is moderately lowered. Is required. Moreover, when crystallinity is too high, orientation crystallization advances at the time of extending | stretching, and there exists a tendency for the film shrinkage | contraction characteristic at the time of heating to fall. Therefore, in the film of the present invention, the copolymerization ratio of D-lactic acid is preferably 1 or more or 99 or less. On the other hand, when the copolymerization ratio of D-lactic acid is 25 or less, or 75 or more, it is desirable because the rupture resistance can be prevented from greatly decreasing.

  In the present invention, in order to more easily adjust the D / L ratio of the component (A), polylactic acid resins having different copolymerization ratios of D-lactic acid and L-lactic acid can be blended. In this case, what is necessary is just to make it the value which averaged D / L ratio of several polylactic acid-type resin included in the said range. Two or more polylactic acid resins with different copolymer ratios of D-lactic acid and L-lactic acid are blended according to the intended use, and the crystallinity is adjusted to balance heat resistance and heat shrinkage characteristics. be able to.

  The component (A) may be a copolymer of D-lactic acid and / or L-lactic acid and at least one selected from α-hydroxycarboxylic acid, aliphatic diol, and aliphatic dicarboxylic acid.

  Examples of the α-hydroxycarboxylic acid include optical isomers of lactic acid (D-lactic acid for L-lactic acid and L-lactic acid for D-lactic acid), glycolic acid, 3-hydroxybutyric acid, 4 A bifunctional aliphatic hydroxy-carboxylic acid such as -hydroxybutyric acid, 2-hydroxyn-butyric acid, 2-hydroxy3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methylbutyric acid, 2-hydroxycaprolactone acid, Examples include lactones such as caprolactone, butyl lactone and valerolactone.

  Examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. Furthermore, examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid.

  The copolymerization ratio of a copolymer of lactic acid and at least one selected from α-hydroxycarboxylic acid, aliphatic diol, and aliphatic dicarboxylic acid is lactic acid: (α-hydroxycarboxylic acid, aliphatic diol, and aliphatic. The mass ratio of at least one selected from dicarboxylic acids is preferably 95: 5 to 10:90, more preferably 90:10 to 20:80, and still more preferably 80:20 to 30:70. 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.

  As the polymerization method for the component (A), any known method such as a condensation polymerization method or a ring-opening polymerization method can be employed. 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 weight average molecular weight of the component (A) is preferably 20,000 or more, more preferably 40,000 or more, further preferably 60,000 or more, and preferably 400,000 or less, more preferably 350,000. Hereinafter, it is more preferably 300,000 or less. When the 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. The mass average molecular weight can be generally measured by GPC (gel permeation chromatography) or viscosity method.

  Examples of the commercially available product of the component (A) include “NatureWorks” (manufactured by Nature Works), “LACEA” (manufactured by Mitsui Chemicals), “REVODE” (manufactured by Kaisho Biomaterials), and the like.

Core shell rubber (component B)
The (B) component core-shell rubber is a polymer composed of a core layer and at least one shell layer covering the core layer. The number of layers of the shell is not particularly limited, and may be a single layer or two or more layers.

As the core layer of component (B), those having rubber elasticity are preferable for improving impact resistance. For example, each of acrylic, silicone, styrene, nitrile, conjugated diene, urethane, and olefin The thing consisting of a polymer etc. is mentioned. Among these, from the viewpoint of transparency, which is one of the required characteristics of the heat-shrinkable film, the core layer is preferably silicone rubber, acrylic rubber, or silicone / acrylic composite rubber.
Among them, a polymer containing an acrylate ester is preferable from the viewpoint of the appearance of the film. The acrylic ester may be any acrylic ester composed of an acrylic acid component and an alcohol component, but an acrylic ester having an alcohol component having 1 to 15 carbon atoms is preferred. Specific examples of preferred acrylic esters include methyl (meth) acrylate, ethyl (meth) (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. Primary alkyl esters of acrylic acid such as isobutyl, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate; glycidyl acrylate, allyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, Examples thereof include trimethoxysilylpropyl acrylate, trifluoroethyl acrylate, isopropyl acrylate, t-butyl acrylate, sec-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, and trimethylsilyl acrylate. The (meth) acrylic acid ester (a) may be used alone or in combination of two or more.

Especially, as a core layer, what has rubber elasticity is preferable for the impact resistance improvement which is one of the required characteristics of a heat-shrinkable film. Specific examples thereof include a polymerization component obtained by polymerizing ethyl acrylate, butyl acrylate, 2-ethylhexyl (meth) acrylate, or a copolymer component of these components.
Moreover, it is preferable that the acrylic ester component in the core layer is 70% or more for improving impact resistance.

When the shell layer of the component (B) or the shell layer is two or more layers, the shell layer forming the outermost layer includes an unsaturated carboxylic acid ester unit, a glycidyl group-containing vinyl unit, and an aliphatic vinyl unit. And polymers containing aromatic vinyl units, vinyl cyanide units, maleimide units, unsaturated dicarboxylic anhydride units, other vinyl units, and the like.
Of these, unsaturated carboxylic acid ester-based polymers are preferred, and polymers containing acrylic acid esters having a chemical structure different from the acrylic acid esters preferred for the core layer are more preferred. In addition, what is necessary is just to contain at least acrylic ester (b) which has a chemical structure different from acrylic ester (a), and may further contain acrylic ester (a) as the polymerization component.

  Typical examples of the acrylic ester in the shell layer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, methacrylic acid 2 Methacrylic acid alkyl esters such as ethylhexyl and lauryl methacrylate; methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate; methacrylic acid aryl esters such as phenyl methacrylate; methacrylic acid aralkyl esters such as benzyl methacrylate; glycidyl methacrylate; Examples include allyl methacrylate; trimethylsilyl methacrylate; trimethoxysilylpropyl methacrylate. In particular, the shell layer is preferably formed of a polymer containing methyl (meth) acrylate from the viewpoint of compatibility with the polylactic acid resin (A).

In the present invention, the core-shell type rubber of component (B) includes a core layer having a polymer containing an acrylate ester, and a shell layer having a polymer containing an acrylate ester having a chemical structure different from that of the acrylate ester, Particularly preferred is a polymer comprising
The acrylic ester component in the core-shell type rubber (B) component is preferably 80% or more (based on the total mass of the core and shell) for improving impact resistance.
In the present specification, “(meth) acryl” means “acryl or methacryl”.

  The production method of component (B) is not particularly limited, and can be obtained by a known polymerization method, for example, suspension polymerization or emulsion polymerization of a desired raw material monomer (a mixture containing a specific ratio). .

  The particle size of the component (B) is not particularly limited, but the average particle size is 0.01 μm or more, preferably 0.02 μm or more, more preferably 0.05 μm or more, preferably 100 μm or less, preferably Is 50 μm or less, more preferably 20 μm or less. If the average particle diameter is 0.01 μm or more, it is preferable because it is sufficient for exhibiting a fracture resistance effect, and if it is 100 μm or less, the surface is rough even when added to the outermost layer. The increase in external haze due to, for example, is small, and even when printing is performed on the film of the present invention to enhance the design, it is preferable that no ink loss occurs and the appearance of the printed pattern is impaired. From the viewpoint of bending whitening resistance, the smaller the particle size, the more the stress applied to the core-shell rubber (B) by the polylactic acid resin (A) at the time of bending is dispersed and the formation of voids is suppressed. Can be suppressed, the smaller the particle size, the better. The average particle diameter of the component (B) can be generally measured by a dynamic light scattering method or a laser diffraction method.

  The mass ratio of the core layer and the shell layer constituting the component (B) is not particularly limited, but the core layer is 40 parts by mass or more, preferably 50 parts by mass with respect to 100 parts by mass of the component (B). As mentioned above, More preferably, it is 60 mass parts or more, and a shell layer is 40 mass parts or less, Preferably it is 30 mass parts or less, More preferably, it is 20 mass parts or less. If the core layer is 40 parts by mass or more, the impact resistance effect can be maintained, which is preferable.

  Examples of commercially available products of component (B) include “Kane Ace” (manufactured by Kaneka), “Metablene” (manufactured by Mitsubishi Rayon Co., Ltd.), “Paraloid” (manufactured by Rohm and Haas), “Staffyroid” (Gantz Kasei). Product) or “Paraface” (manufactured by Kuraray Co., Ltd.) and the like, and these can be used alone or in combination of two or more.

The content of the component (B) is preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 12% based on the mass (100% by mass) of the resin composition constituting the (I) layer. % By mass or less, more preferably 10% by mass or less, preferably 5% by mass or more, more preferably 10% by mass or more, based on the mass (100% by mass) of the resin composition constituting the layer (II). Moreover, Preferably it is 30 mass% or less, More preferably, it is 20 mass% or less.
If the content of the component (B) constituting the layer (I) is 3% by mass or more, and the content of the component (B) constituting the layer (II) is 5% by mass or more, the request as a heat shrinkable film is required. Impact resistance sufficient for quality can be obtained. Conversely, when the content of the component (B) constituting the layer (I) exceeds 12% by mass, or the content of the component (B) constituting the layer (II) exceeds 30% by mass. In such a case, the rigidity of the film is lowered, and the handling property becomes inferior at the time of secondary processing or the like, and the workability is lowered. In order to obtain desired physical properties, it is desirable that the amount of rubber in the (I) layer and the (II) layer is within the above range and one is increased and the other is decreased.

  In addition, in the present invention, the resin constituting each layer may be mixed with other resins in addition to the component (A) and the component (B) as long as the effects of the present invention are not impaired. Even in this case, the polylactic acid resin as the component (A) is preferably 50% or more out of the total 100% by mass of the resin alone, in order to sufficiently obtain the effects of the present invention.

  In the present invention, in order to impart slipperiness of the film and prevent blocking, a method of blending an incompatible resin with each layer or an antiblocking agent may be further added to the extent that the effects of the present invention are not impaired.

  Examples of the anti-blocking agent include inorganic particles such as silica, talc, kaolin, and calcium carbonate, inorganic oxides, carbonates, and organic particles such as crosslinked acrylic, crosslinked polyester, crosslinked polystyrene, and silicone. Can be mentioned. Further, organic particles having a multilayer structure polymerized in multiple stages can also be used. Of these, silica and organic particles are preferably used.

  It is necessary to select an appropriate addition amount and type of the anti-blocking agent so that the film surface is roughened to exhibit slipping and blocking resistance, and transparency and the gloss of the film are not impaired. The amount of the anti-blocking agent added is preferably 0.01% by mass or more, more preferably 0.015% by mass or more, and still more preferably, based on the mass of the entire resin composition constituting each layer (100% by mass). It is 0.02 mass% or more, and is preferably 2 mass% or less, more preferably 1.5 mass% or less, and still more preferably 1 mass% or less. If the amount of the anti-blocking agent added is too small (less than 0.01% by mass), the anti-blocking agent is not sufficiently deposited on the film surface and it is difficult to form irregularities on the film surface. The blocking ability may not be expressed. On the other hand, if the amount of antiblocking agent is too large (over 2% by mass), excessive unevenness of the film surface is likely to occur, hindering transparency due to surface roughness, winding of a film roll due to excessive slipping, etc. Is likely to occur.

  The shape of the anti-blocking agent is not particularly limited, but it is spherical from the viewpoint of suppressing aggregation in each layer, from the viewpoint of uniform dispersion, suppressing irregular reflection of transmitted light, and unevenness formed on the film surface. Is preferably used. The average particle size of the antiblocking agent is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less. If the average particle size of the anti-blocking agent is too small (less than 0.5 μm), it is difficult for the anti-blocking agent to deposit on the film surface, and the anti-blocking agent deposited on the surface also exhibits slipperiness and blocking resistance. It is difficult to give enough unevenness. On the other hand, when the average particle size of the anti-blocking agent is too large (over 10 μm), when printing is performed on the film of the present invention and the design is enhanced, ink loss or the like is likely to occur and the appearance of the printed design may be impaired. is there. The particle size distribution of the anti-blocking agent is not particularly limited, but preferably has a narrow particle size distribution because of the adverse effect of the particle size. If the particle size distribution is too wide, it may include those that deviate from the preferred particle size range described above.

<Film structure>
The layer structure of the film of this invention should just be comprised from 2 layers, at least (I) layer and (II) layer, for example, even if it is a 2 layer structure which laminated | stacked (I) layer and (II) layer, Alternatively, the (I) layer / (II) layer / (I) layer may have a three-layer structure (I) layer / (I) layer. As in the case of the / (II) layer, the (II) layer may have a three-layer structure that the outermost layers on both sides have. In particular, having the (I) layer with a small content of the core-shell type rubber (B) as the outermost layer and the (II) layer with a high content of the core-shell type rubber (B) as the middle layer, the rigidity as the entire film layer Therefore, the (I) layer / (II) layer / (I) layer configuration is preferable. Moreover, the film provided with the layer structure which laminated | stacked the other layer (III) layer may be sufficient. Specifically, (I) layer / (II) layer, (I) layer / (II) layer / (I) layer, (I) layer / (II) layer / (III) layer / (I) layer, Examples thereof include a laminated film having a layer structure such as (I) layer / (II) layer / (III) layer / (II) layer / (I) layer. In this case, the lamination ratio of each layer can be appropriately adjusted according to the application and purpose.

  Examples of the method for forming the laminate include a co-extrusion method, a method of forming a film of each layer, and then superposing and heat-sealing, a method of bonding with an adhesive, and the like.

The total thickness of the film of the present invention is not particularly limited, whether it is a single layer or a laminate, but it is preferably thinner from the viewpoint of transparency, shrinkage workability, raw material cost, and the like. Specifically, the total thickness of the stretched film is preferably 60 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less. Further, the lower limit of the total thickness of the film is not particularly limited, but is preferably 20 μm or more in consideration of the handleability of the film.
In particular, in the case of three layers (I) layer / (II) layer / (I) layer having a preferred layer structure described above, the thickness ratio is in the range of 1: 8: 1: to 3: 4: 3. Is preferred.

  For each layer constituting the film of the present invention, in addition to the components described above, within the range that does not impair the effects of the present invention, for the purpose of improving and adjusting the molding processability, productivity and various physical properties of the heat shrinkable film, Recycled resin generated from trimming loss etc. of film ears, pigments such as titanium oxide, carbon black, flame retardant, weather resistance stabilizer, heat stabilizer, antistatic agent, melt viscosity improver, crosslinking agent, nucleating agent, Additives such as anti-aging agents can be added as appropriate.

In addition, as a second embodiment of the present invention, a laminated film composed of at least three layers comprising a composition containing a polylactic acid resin (A) and a core-shell type rubber (B) , The content of the core-shell type rubber based on the mass (100% by mass) of the constituent resin composition is based on the content of the core-shell type rubber based on the mass (100% by mass) of the resin composition constituting the front and back layers. The laminated film is stretched in at least one direction and has a heat shrinkage ratio of 30 to 70% in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds. It is a heat-shrinkable laminated film.

In the second embodiment, the polylactic acid resin (A) and the core-shell type rubber (B) contained can be the same as those described in the first embodiment. The other additives that can be contained are as described above, and the film production method and the like are as described below.
In the second embodiment, at least all three layers are composed of a composition containing the polylactic acid resin (A) and the core-shell type rubber (B), but the intermediate layer is more than the surface layer and the back layer. And a large amount of core-shell type rubber (B).

The desirable amount of the core-shell type rubber (B) is preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 12% by mass based on the mass (100% by mass) of the resin composition in the front and back layers. % Or less, more preferably 10% by mass or less, preferably 5% by mass or more, more preferably 10% by mass or more, preferably based on the mass (100% by mass) of the resin composition constituting the intermediate layer. Is 30% by mass or less, more preferably 20% by mass or less.
If the content of the component (B) constituting the layer (I) is 3% by mass or more, and the content of the component (B) constituting the layer (II) is 5% by mass or more, the request as a heat shrinkable film is required. Impact resistance sufficient for quality can be obtained. Conversely, when the content of the component (B) constituting the layer (I) exceeds 12% by mass, or the content of the component (B) constituting the layer (II) exceeds 30% by mass. In such a case, the rigidity of the film is lowered, and the handling property becomes inferior at the time of secondary processing or the like, and the workability is lowered.

<The manufacturing method of the film of this invention>
The film of 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, for example, a resin is melted by using a plurality of extruders, co-extruded from a T die, solidified by cooling with a chilled roll, roll-stretched in the vertical direction, and tenter-stretched in the horizontal direction. An example is a method of obtaining a film by winding, annealing, cooling, and winding with a winder (corona discharge treatment is applied to the surface when printing is performed). Moreover, the method of cutting open the film manufactured by the tubular method and making it flat is also applicable.
The extrusion temperature is preferably 180 to 230 ° C, more preferably 190 to 220 ° C. Controlling the dispersion state of the material by optimizing the extrusion temperature and the shearing state is also effective in bringing various physical properties and mechanical properties of the film described below to desired values.

  The stretching ratio is preferably 2 to 10 times in the longitudinal direction, 2 to 10 times in the transverse direction, more preferably 3 to 6 times in the longitudinal direction, and more preferably 3 to 6 times in the transverse direction. About 3 to 6 times. On the other hand, in applications that shrink mainly in one direction, such as for heat-shrinkable labels, the direction corresponding to the main shrinkage direction is preferably 2 to 10 times, more preferably 4 to 8 times, and the direction perpendicular thereto is preferably It is desirable to select a magnification ratio of 1 to 2 times, more preferably 1.01 to 1.5 times, which is substantially in the category of uniaxial stretching. In addition, 1 time points out the case where it is not extending | stretching.

  A stretched film stretched at a stretch ratio within the range of the uniaxial stretching does not have an excessively large thermal shrinkage rate in a direction orthogonal to the main shrinkage direction. For example, when used as a shrink label, it is attached to a container. It is preferable because sometimes the so-called vertical shrinkage phenomenon, in which the film thermally shrinks in the height direction of the container, can be suppressed.

  The stretching temperature can be appropriately selected depending on the glass transition temperature of the resin used and the properties required for the heat-shrinkable film, but is generally 60 ° C. or higher, preferably 70 ° C. or higher. It is preferably controlled within a range of 90 ° C. or less. Then, the stretched film is not relaxed in molecular orientation after heat treatment or relaxation treatment at a temperature of about 50 to 120 ° C. for the purpose of reducing the natural shrinkage rate or improving the heat shrinkage property, if necessary. It is quickly cooled in time to become a heat-shrinkable film.

  Further, the film of the present invention can be subjected to surface treatment such as corona treatment, printing, coating, vapor deposition, and surface treatment as needed, and further, bag making processing and perforation processing using various solvents and heat sealing.

<Physical and mechanical properties of heat-shrinkable film>
(Heat shrinkage, shrink finish)
In the film of the present invention, it is important that the lower limit of the shrinkage ratio in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds is 30% or more, preferably 35% or more, more preferably 40% or more. It is important that the upper limit is 70%, preferably 65% or less, more preferably 60% or less.
Here, as will be described later, the “heat shrinkage rate” is the percentage of shrinkage with respect to the original size before shrinkage in the vertical direction or horizontal direction, expressed as a% value. 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. The “main shrinkage direction” means the larger one of the longitudinal direction and the transverse direction in the stretching direction. For example, when attached to a bottle, it is a direction corresponding to the outer circumferential direction.

  At present, the shrinkage processing machine most commonly used industrially for labeling of PET bottles is generally called a steam shrinker that uses steam as a heating medium for shrinking. Furthermore, the heat-shrinkable film needs to be sufficiently heat-shrinked at a temperature as low as possible from the viewpoint of the influence of heat on the object to be coated. However, in the case of a film with high temperature dependence and extremely different shrinkage ratios depending on the temperature, parts with different shrinkage behavior tend to occur with respect to the temperature spots in the steam shrinker, so shrinkage spots, wrinkles, avatars, etc. occur. However, the shrink-finished appearance tends to deteriorate. From the viewpoint of including these industrial productivity, if the thermal shrinkage rate in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds is 30% or more, it is sufficiently adhered to the object to be coated within the shrinkage processing time. It is preferable because it can produce a good shrink-finished appearance without spots, wrinkles and avatars. From this, it is important that the film of the present invention has a heat shrinkage ratio in the main shrinkage direction of 30% or more and 70% or less when immersed in warm water at 80 ° C. for 10 seconds.

  In the present invention, when the heat shrinkage rate in the main shrink direction of the heat-shrinkable laminated film is 30% or more when immersed in warm water at 80 ° C. for 10 seconds, the laminated film having the composition defined in the present invention Further, this value can be appropriately adjusted depending on the stretching temperature and the stretching ratio.

  On the other hand, by reducing the shrinkage rate in the direction perpendicular to the main shrinkage direction, it is possible to obtain more excellent shrinkage finish. When the film of the present invention is used as a heat-shrinkable label, the heat shrinkage rate in the direction orthogonal to the main shrinkage direction is preferably 5% or less when immersed in warm water at 80 ° C. for 10 seconds. More preferably, it is more preferably 3% or less.

  If the film has a thermal shrinkage rate of 5% or less in the direction perpendicular to the main shrinkage direction, the dimension itself in the direction perpendicular to the main shrinkage direction after shrinkage may be shortened, or the printed pattern or characters after shrinkage may be distorted. In the case of a square bottle, it is preferable because troubles such as vertical sink are unlikely to occur. In this case, the lower limit of the heat shrinkage rate is 0%. The value of the heat shrinkage rate can also be adjusted similarly to the heat shrinkage rate in the main shrinkage direction.

(transparency)
For the transparency of the film of the present invention, for example, when a film having a thickness of 40 μm is measured according to JIS K7105, the haze value is preferably 8% or less, more preferably 6% or less, and 5% or less. More preferably. If the haze value is 8% or less, the transparency of the film can be obtained and a display effect can be obtained.

  In the film of the present invention, in order to set the haze value of the heat-shrinkable film to 8% or less, it is necessary to form a film having the composition defined in the present invention. The amount of component B) can be adjusted by keeping it as low as possible within the scope of the present invention.

(Impact resistance)
The impact resistance of the film of the present invention is evaluated by a hydroshot value. Especially in label applications, the energy (N · mm) when the sample breaks in a test under a 23 ° C. environment is preferably 980 N · mm or more. More preferably, it is 1225 N · mm or more, and more preferably 1470 N · mm or more. A hydroshot value of 980 N · mm or more in an environment of 23 ° C. is preferable because it is difficult to cause problems such as film breakage during printing and bag making processes. In addition, when the tension applied to the film increases as the speed of processes such as printing and bag making increases, it is particularly preferable that the tensile breaking elongation is 1225 N · mm or more, so that it is difficult to break. Although there is no particular limitation on the upper limit, when trying to give too much elongation, the rigidity of the film tends to decrease.
In the present invention, in order to set the value of the hydroshot to the above, for example, in addition to the adjustment of the material composition of the layer, the adjustment of the extrusion conditions in the film forming process, the adjustment of the stretching conditions, the adjustment of the heat shrinkage rate, the lamination In the case of a film configuration, the value can be adjusted to the above value by appropriately performing the lamination ratio.
The adjustment of the extrusion conditions mentioned here includes, for example, controlling the dispersion state of the material by optimizing the extrusion temperature and the shearing state. The adjustment of the stretching conditions includes, for example, controlling the orientation state of the film by optimizing the stretching temperature and the stretching ratio.

(Folding whitening resistance)
In the present invention, excellent bending whitening resistance can be achieved by appropriately adjusting the type and amount of the core-shell type rubber (B) to be used.

[Molded product of the present invention, heat-shrinkable label of the present invention, and container of the present invention]
The present invention relates to a molded article (the molded article of the present invention) using the heat-shrinkable laminated film as a base material, and the present invention relates to a heat-shrinkable label (this book) using the heat-shrinkable laminated film as a base material. The present invention further relates to a container (the container of the present invention) using the molded product or equipped with the heat-shrinkable label.

  The film of the present invention is processed from a flat shape to a cylindrical shape or the like according to an object to be packaged 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 the print to the required width while the printing side is inside. It suffices to fold and seal the center to make it cylindrical. In this case, the shape of the seal portion is so-called envelope pasting.

  Examples of the center sealing method include an adhesion method using an organic solvent, a heat sealing method, an adhesive method, and an impulse sealer method. Among these, from the viewpoint of productivity and appearance, an adhesion method using an organic solvent is preferably used.

  The film of the present invention is excellent in the heat shrinkage property, shrinkage finish, transparency, etc. of the film, and its use is not particularly limited. Can be used as a base material for various molded products such as bottles (blow bottles), trays, lunch boxes, prepared food containers, dairy products containers and the like. The obtained molded product can be used as a container or the like.

  In addition, the film of the present invention can be used as a base material for a heat-shrinkable label for food containers (for example, PET bottles, glass bottles, preferably PET bottles for soft drinks or foods). In this case, even a complicated shape (for example, a cylinder with a narrow center, a square column with a corner, a pentagonal column, a hexagonal column, etc.) can be closely attached to the shape and is mounted beautifully without wrinkles or avatars. Label. And the food container which installed the label can be used as a container. In addition, the said molded article and container can be produced by using a normal shaping | molding method.

  Since the film of the present invention has excellent low temperature shrinkage and shrinkage finish properties, in addition to heat-shrinkable label materials used for plastic molded products that are deformed when heated to high temperatures, it has a coefficient of thermal expansion and water absorption. Materials very different from the heat-shrinkable film of the present invention, for example, polyolefin resin such as metal, porcelain, glass, paper, polyethylene, polypropylene, polybutene, polymethacrylate resin, polycarbonate resin, polyethylene terephthalate, polybutylene terephthalate It can utilize suitably as a heat-shrinkable label raw material of the package (container) which used at least 1 sort (s) chosen from polyester-type resins, such as such as a constituent material.

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

The present invention will be described below 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 take-up (flow) direction of the laminated film is described as the “longitudinal” direction (or MD), and the perpendicular direction thereof is described as the “transverse” direction (or TD).

<Measurement method>
(1) Thermal shrinkage The obtained film was cut into a size of 100 mm in length and 100 mm in width and immersed in a hot water bath at 80 ° C. for 10 seconds, and the shrinkage was measured. For the thermal shrinkage, the ratio of shrinkage to the original size before shrinkage is expressed in% in the transverse direction (TD).

(2) Haze value In order to evaluate the transparency of the obtained film, the haze value was measured according to JIS K7105.
◎: When haze value is 5% or less ○: When haze value exceeds 6% and 8% or less ×: When haze value exceeds 8%

(3) Shrinkage finishing property The obtained film was cut out by MD160 mm × TD235 mm, folded so as to overlap 10 mm by TD, and the overlapped portion was heat-sealed to form a cylindrical shape. Next, this cylindrical film was covered with a 500 ml polyhedral bottle up to the bottom surface of the bottle to produce a finish evaluation sample. The sample for evaluation was a film that was shrunk into a bottle by allowing the temperature of each zone in the tunnel to pass through for 5 seconds under the following temperature conditions without rotating in a steam heating type 4 m (3-zone configuration) shrink tunnel. It was evaluated by confirming whether there were any folds or wrinkles due to the hip folds, or whether it was insufficiently contracted. Evaluation was performed with each sample N = 10. The temperature conditions in the shrinker were set as follows.
Temperature conditions: 1 zone / 70 to 75 ° C., 2 zone / 94 to 97 ° C., 3 zone / 95 to 101 ° C.
Nozzle position in the tunnel for jetting steam: 1 Zone / Lower film, 2 First half / Central film, 2 Second half / Whole film, 3 Zone / Whole film temperature adjustment: Steam volume by opening / closing the steam piping valve leading to the nozzle Adjust and adjust.

After film coating, the following criteria were evaluated.
◎: Shrinkage is sufficient and no wrinkles, avatars, whitening and distortion occur. ○: Shrinkage is sufficient, but wrinkles, avatars, whitening and distortion occur slightly, but there is no practical problem. △: Shrinkage is sufficient. Wrinkles, avatars, whitening, and slight distortion occur, which may be a problem depending on the application. ×: Insufficient shrinkage, or wrinkles, avatars, and distortion are remarkable.

(4) Impact resistance Using a hydro-shot high-speed impact tester (“HTM-1 type” manufactured by Shimadzu Corporation), a sample having a thickness of 40 μm cut into a size of 100 mm in the vertical direction and 100 mm in the horizontal direction is clamped. At a temperature of 0 ° C., a ½ inch diameter impact core is dropped at a drop speed of 3 m / sec at the center of the film to give an impact, and the energy (N · mm) when the sample breaks is 5 times. The average value of the measured values was measured and evaluated according to the following criteria.
◎: When the sample breaks energy exceeding 1470 N · mm ○: When the sample breaks energy exceeds 980 N · mm and is 1470 N · mm or less ×: Energy when the sample breaks 980 N・ When it is less than mm

(5) Bending whitening resistance The obtained film was cut into a size of 10 cm x 10 cm to prepare a sample. This sample was bent so that the angle formed by the film in the same direction as the MD direction was 180 degrees. At this time, the whitening state of the bent portion was visually observed, the case where whitening was not observed in the bent portion was indicated by the symbol “◯”, and the case where whitening was observed in the bent portion was indicated by the symbol “×”. .

The raw materials used in each example and comparative example are as follows.
Component (A) (polylactic acid resin)
-Product made from Nature Works LLC, a brand name: NatureWorks4060D, D body / L body weight = 12/88, It abbreviates as "PLA (A1)."
-Product made from Nature Works LLC, a brand name: NatureWorks4043D, D body / L body weight = 4.25 / 95.75, and it abbreviates as "PLA (A2)."
Component (B) (core shell type rubber , manufactured by Kaneka Corporation, trade name: Kane Ace FM-40, core layer: acrylic polymer, shell layer: methyl methacrylate polymer (core layer 67% by mass, acrylic heavy in core layer) Combined content: 100% by mass) Refractive index: 1.44, abbreviated as “core shell type rubber (B1)”.
-Kaneka Co., Ltd., trade name: Kane Ace FM-21, core layer: acrylic polymer, shell layer: methyl methacrylate polymer (core layer 63 mass%, acrylic polymer content in core layer 100 mass%), Abbreviated as “core-shell type rubber (B2)” with a refractive index of 1.44.
-Made by Mitsubishi Rayon Co., Ltd., trade name: methabrene W450, core layer: acrylic polymer, shell layer: methyl methacrylate polymer (core layer 65 mass%, acrylic polymer content in core layer 100 mass%), refraction The rate is 1.44, abbreviated as “core-shell type rubber (B3)”.
-Made by Mitsubishi Rayon Co., Ltd., trade name: Methabrene W600, core layer: acrylic polymer, shell layer: methyl methacrylate polymer (core layer 69 mass%, acrylic polymer content in core layer 100 mass%), refraction The rate is 1.44, abbreviated as “core-shell type rubber (B4)”.
-Kaneka Co., Ltd., trade name: Kane Ace FM, core layer: acrylic polymer, shell layer: methyl methacrylate polymer (core layer 46 mass%, acrylic polymer content in core layer 100 mass%), refractive index 1.44, abbreviated as “core shell type rubber (B5)”.
-Made by Mitsubishi Rayon Co., Ltd., trade name: methabrene S2001, core layer: silicone-acrylic polymer, shell layer: methyl methacrylate polymer (core layer 71 mass%, acrylic polymer content in core layer 63 mass%) , Refractive index 1.44, abbreviated as “core shell type rubber (B6)”.

Examples 1 to 9, Comparative Examples 1 to 3, Reference Example (I) The resin composition used for the layer and (II) layer was prepared by mixing the raw materials in the formulations shown in Tables 1 and 2, respectively. After putting into a shaft extruder (Mitsubishi Heavy Industries, Ltd.), melting and mixing at a set temperature of 200 ° C., and extruding from a strand die with a set temperature of 200 ° C., the resin composition cooled in a water tank is cut with a strand cutter, It was set as a pellet.
Next, the resin was introduced by a single screw extruder (manufactured by Mitsubishi Heavy Industries, Ltd.), and after melt mixing at each extruder set temperature of 200 ° C., the thickness of each layer was (I) layer / (II) layer / (I) layer = 24 μm / 152 μm / 24 μm Co-extruded, taken up with a cast roll at 60 ° C., cooled and solidified to obtain an unstretched sheet having a width of 200 mm and a thickness of 200 μm. Then, using a film tenter (manufactured by Kyoto Kikai Co., Ltd.), this sheet was subjected to a tenter speed of 3.5 m / min, 5 ° C., stretching 75 ° C., heat treatment 90 ° C., preheating 1 zone, stretching 2 zone, and heat treatment 3 zone. The film was stretched 5 times in the transverse direction to obtain a heat-shrinkable laminated film having a thickness of 40 μm.

Comparative Example 4
A sample was collected by the same method as described above, except that an unstretched sheet having a thickness of 40 μm was obtained.

  Regarding the films obtained in Examples 1 to 9, the heat shrinkage rate is sufficient, the shrink finish is good, and the hydroshot which is an index of the impact resistance of the film is also required as a heat shrinkable film. Good value satisfying quality was shown. Moreover, the appearance of the film was good, the transparency seen from the haze was good, and the whitening resistance was also good.

  On the other hand, regarding the film obtained in Comparative Example 1 or Comparative Example 2 that does not contain the core-shell type rubber (B) in the (I) layer or (II) layer, although the transparency of the film is good, the impact resistance is high. It was low and was not sufficient to obtain the fracture resistance required in the printing process and bag making process, which are heat shrink film processing steps. Further, regarding the film obtained in Comparative Example 3 in which the core-shell type rubber (B) contains an amount exceeding the scope of the present invention, the bending whitening resistance is poor, and sufficient heat shrinkage cannot be obtained, resulting in shrink finish. Was inferior. Furthermore, although the unstretched laminated film obtained in Comparative Example 4 had good film transparency, the heat shrinkage rate was not sufficient, and the finish and impact resistance were inferior.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. However, the present invention can be changed as appropriate without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and a heat-shrinkable laminated film accompanied by such a change, a molded article using the film, and heat Shrinkable labels and containers formed with the molded articles and labels should also be understood as being within the scope of the present invention.

  The heat-shrinkable laminated film of the present invention can be suitably used for applications such as shrink wrap, shrink-bound wrap and shrink labels.

Claims (7)

  A laminated film comprising at least two layers comprising a composition containing a polylactic acid resin (A) and a core-shell rubber (B), wherein the film comprises a polylactic acid resin (A) and a core-shell rubber (B ), And the total mass of the polylactic acid resin (A) and the core-shell type rubber (B) is 100% by mass, the core-shell type rubber (B) is added from 3 to 12% by mass of the resin composition. A layer (I) comprising the polylactic acid resin (A ′) and the core-shell type rubber (B ′), and the polylactic acid resin (A ′) and the core-shell type rubber (B ′). In a total mass of 100% by mass, the core-shell type rubber (B ′) includes a layer (II) composed of 5 to 30% by mass of the resin composition, the laminated film is stretched in at least one direction, and 80 ° C. Main yield when immersed in warm water for 10 seconds Heat-shrinkable laminated film, wherein the direction of the heat shrinkage rate is 30 to 70%.   The core shell type rubber (B) or (B ′) has a core layer having a polymer containing an acrylate ester, and a shell layer having a polymer containing an acrylate ester having a chemical structure different from the acrylate ester, The heat-shrinkable laminated film according to claim 1, which is a polymer composed of:   The heat-shrinkable laminated film according to claim 1, wherein the film has a thickness of 20 to 40 μm, a haze value of 8% or less, and a hydroshot value of 980 N · mm or more. . Based on the mass (100% by mass) of the resin composition comprising at least three layers composed of a composition containing the polylactic acid resin (A) and the core-shell type rubber (B), and constituting the intermediate layer The core-shell type rubber content is greater than the content of the core-shell type rubber based on the mass (100% by mass) of the resin composition constituting the front and back layers, and the laminated film is at least unidirectional A heat shrinkable laminate film having a heat shrinkage ratio in the main shrinkage direction of 30 to 70% when immersed in warm water at 80 ° C. for 10 seconds.   The molded article which has the heat-shrinkable laminated film in any one of Claims 1-4 as a base material. The heat-shrinkable label which has the heat-shrinkable laminated film in any one of Claims 1-4 as a base material.   A container using the molded article according to claim 5 or equipped with the heat-shrinkable label according to claim 6.