JP7004048B1 - Heat shrinkable films, packaging materials, articles or containers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-shrinkable film having excellent rigidity, heat-shrinkability, and perforation hand-cutting property even in a thinned heat-shrinkable film. Further, a packaging material made of the heat-shrinkable film, a molded product or a container to which the packaging material is attached is provided. A heat-shrinkable film having at least one layer made of a resin composition (Z) containing a polyester-based resin (A) as a main component, and a heat-shrinkable film satisfying the following a) and b). do. a) The polyester-based resin (A) contains a copolymerized polyester-based resin. b) Birefringence ΔN is 0.055 or more and 0.100 or less. [Selection diagram] None

Description

INDUSTRIAL APPLICABILITY The present invention is suitable for food packaging materials, beverage packaging materials, pharmaceutical / medical packaging materials, chemical packaging materials, cosmetic packaging materials, toiletry packaging materials, industrial packaging materials, agricultural material packaging materials, and the like. With respect to heat shrinkable films, packaging materials, molded products or containers that can be utilized in.

Plastic films are used in a variety of applications, including foods, beverages, pharmaceuticals / medical products, chemicals, cosmetics, toiletries, and industrial products. On the other hand, in recent years, plastic disposal and marine pollution have become global social problems. Therefore, there is a growing movement to reduce the amount of plastic discarded by reducing the thickness (thinning) of plastic containers and plastic films. This approach to thinning is also being actively studied for heat-shrinkable films attached to containers such as beverages and PET bottles filled with seasonings.

Generally, when a heat-shrinkable film is attached to a molded product or a container, the heat-shrinkable film is a tubular material having a diameter slightly larger than the outer diameter of the container by sealing the edges of the film with a solvent or the like. Is processed into. After that, the film is cut to a predetermined coating length (height), coated on a container or the like, and heated as it is to shrink the film and attach it to the container.
Further, the heat-shrinkable film is often subjected to intermittent hole processing (perforations) in advance so that it can be easily attached to and detached from the container after mounting for recycling after use.

Here, when the rigidity of the heat-shrinkable film is low, there has been a problem that the film collapses when the container is coated, the mouth of the tube does not open neatly, and improper mounting is likely to occur. Therefore, a polyester-based heat-shrinkable film having high rigidity is often used as the heat-shrinkable film. For example, Patent Document 1 discloses a heat-shrinkable laminated film containing a resin composition composed of an amorphous polyester resin and a crystalline polyester resin as a main component on the surface layer. Further, Patent Document 2 discloses a seamless heat-shrinkable polyester tube.

Japanese Unexamined Patent Publication No. 2006-159901 Japanese Unexamined Patent Publication No. 2004-276364

Patent Document 1 states that by mixing a crystalline polyester resin with an amorphous polyester resin, the shrinkage start temperature can be adjusted, the mechanical strength in the stretching direction can be improved, and the solvent resistance of printing ink and the like can be improved. It has been confirmed, and polybutylene terephthalate and polytrimethylene terephthalate are exemplified as crystalline polyester-based resins.
However, in order to solve the technical problem of imparting rigidity of the heat-shrinkable film in order to meet the further demand for thinning in recent years, the problem of selecting the type of crystalline polyester resin and controlling the orientation of the heat-shrinkable film. The technical idea of is not mentioned. Further, there is no mention of the technical idea of imparting the ease of tearing (hand-cutting property) of the film along the perforations by controlling the orientation of the heat-shrinkable film.

Further, in Patent Document 2, by defining the storage elastic modulus at 20 ° C to 70 ° C, it is attempted to maintain both the waist of the tube at the time of coating and the processability at the time of heating. Polyethylene terephthalate, A combination of polybutylene terephthalate and polytrimethylene terephthalate is exemplified, but the technical idea of controlling the orientation of the heat-shrinkable film and the orientation control in order to impart further rigidity to the thinned heat-shrinkable film are exemplified. There is no mention of the technical idea of imparting perforation cutability.

The present invention has been made to solve the above problems, and to provide a heat-shrinkable film having excellent rigidity, heat-shrinkability, and perforation cutability even in a thinned heat-shrinkable film. It is in. Another object of the present invention is to provide a packaging material using the heat-shrinkable film, a molded product or a container to which the packaging material is attached.

As a result of diligent studies, the present inventor has succeeded in obtaining a heat-shrinkable film that can solve the above-mentioned problems of the prior art by controlling the composition of the polyester resin and the orientation of the heat-shrinkable film. The present invention has been completed.

That is, the gist of the present invention is the following [1] to [10].
[1] A heat-shrinkable film having at least one layer made of a resin composition (Z) containing a polyester resin (A) as a main component.
A heat-shrinkable film that satisfies the following a) and b).
a) The polyester resin (A) contains a copolymerized polyester resin b) The birefringence ΔN is 0.055 or more and 0.100 or less [2] The heat shrinkage according to [1] satisfying the following c) to e). Sex film.
c) The plane orientation coefficient ΔP is 0.035 or more and 0.073 or less d) The amount of heat of crystal melting (ΔHm) when the temperature is raised at 10 ° C./min by the differential scanning calorimetry of the resin composition (Z). 1 J / g or more and 35 J / g or less e) The heat shrinkage rate in the main shrinkage direction when immersed in warm water at 100 ° C. is 45% or more [3] Tear by the orthogonal method according to JIS K7128-3 (1998). The heat-shrinkable film according to [1] or [2], wherein in terms of strength, the absolute value of the difference between the tear strength in the main contraction direction and the tear strength in the direction orthogonal to the main contraction direction is 11 N or less.
[4] The heat-shrinkable film according to any one of [1] to [3], wherein the resin composition (Z) contains a terephthalic acid residue as a dicarboxylic acid residue.
[5] The heat-shrinkable film according to any one of [1] to [4], wherein the resin composition (Z) contains an ethylene glycol residue as a diol residue.
[6] The resin composition (Z) contains 1,4-cyclohexanedimethanol residue, neopentyl glycol residue, 1,3-propanediol residue, and 1,4-butanediol residue as diol residues. The heat-shrinkable film according to any one of [1] to [5], which comprises at least one selected from diethylene glycol residues.
[7] Any of [1] to [6] containing 1,3-propanediol in an amount of 1 mol% or more and 45 mol% or less with respect to 100 mol% of all diol residues contained in the resin composition (Z). The heat-shrinkable film described in Crab.
[8] The heat-shrinkable film according to any one of [1] to [7], wherein the resin composition (Z) contains a residue derived from biomass.
[9] A packaging material using the heat-shrinkable film according to any one of [1] to [8].
[10] A molded product or container to which the packaging material according to [9] is attached.

According to the present invention, even when the thickness of the heat-shrinkable film is further reduced, it is possible to obtain a heat-shrinkable film having excellent rigidity, heat-shrinkability, and perforated hand-cutting property. Therefore, it is possible to obtain a heat-shrinkable film for food packaging. It can be suitably used for materials, packaging materials for beverages, packaging materials for pharmaceuticals and medical treatments, packaging materials for chemicals, packaging materials for cosmetics, packaging materials for toiletries, industrial packaging materials, packaging materials for agricultural materials, and the like.

Hereinafter, the heat-shrinkable film, packaging material, molded product, and container of the present invention as an example of the embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.

In addition, in this specification, a "main component" means a component which occupies the most mass% when the total of the constituent components is 100% by mass, and is preferably 50% by mass or more, preferably 60% by mass. The above is more preferable, and 70% by mass or more is further preferable.

Further, when "X to Y" (X and Y are arbitrary numbers) is described, it means "X or more and Y or less", and "preferably larger than X" and "preferably smaller than Y". It includes the meaning of ".

In addition, in this specification, "film" has a meaning including a thick sheet to a thin film.

In the present specification, "at least one direction" means the vertical direction when the flow direction from the extruder is the vertical direction (MD) and the orthogonal direction thereof is the horizontal direction (TD) in the process of manufacturing the heat-shrinkable film. And either or both of the horizontal directions, and the "main shrinkage direction" means the direction in which the heat shrinkage rate is larger in the vertical direction and the horizontal direction.

Further, even if the upper limit value and the lower limit value of the numerical range in the present specification are slightly out of the numerical range specified by the present invention, the present invention has the same effect as within the numerical range. It shall be included in the equal range of.

The present invention is a heat-shrinkable film having at least one layer made of a resin composition (Z) containing a polyester resin (A) as a main component.
A heat-shrinkable film satisfying the following a) and b).
a) The polyester resin (A) contains a copolymerized polyester resin b) Birefringence ΔN is 0.055 or more and 0.100 or less

[Polyester resin (A)]
The polyester-based resin (A) used in the present invention is not particularly limited as long as it is a resin having an ester bond in the main chain.
Examples of the polyester resin (A) include polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexylene methylene terephthalate, polyethylene succinate, and polybutylene succinate. Polyester resin derived from the dicarboxylic acid residue and the diol residue, a polyester resin obtained by polymerizing a monomer having a carboxylic acid residue such as polylactic acid and poly-ε-caprolactam and an alcohol residue in one molecule, And these copolymers and the like. As these polyester-based resins (A), one kind may be used alone, or two or more kinds of polyester-based resins (A) may be used.
When the polyester resin (A) is composed of two or more types, the total is the mass of the polyester resin (A), and the mass ratio of the polyester resin (A) in the resin composition (Z) is calculated. To.

In the present invention, the polyester resin (A) is preferably a polyester resin derived from a dicarboxylic acid residue and a diol residue.

Further, the polyester-based resin (A) needs to contain a copolymerized polyester-based resin. That is, it is a mixture in which at least one of the dicarboxylic acid residue and the diol residue, which are the polymerization components of the polyester resin (A), is composed of two or more kinds of residues.
When the polyester resin (A) is composed of two or more types of dicarboxylic acid residues, the dicarboxylic acid residue occupying the largest mol% with respect to 100 mol% of all dicarboxylic acid residues is "first. It is referred to as "dicarboxylic acid residue", and hereinafter, "second dicarboxylic acid residue", "third dicarboxylic acid residue", ... It is called "acid residue".).
Further, when the polyester resin (A) is composed of two or more types of diol residues, similarly, the diol residue occupying the largest mol% with respect to 100 mol% of all diol residues is "first. "Glycol residue", hereinafter, "second diol residue", "third diol residue", ... In descending order of mol% (hereinafter, these are collectively referred to as "second or lower diol residue". It is called.).
In the polyester resin (A), since at least one of the dicarboxylic acid residue and the diol residue is composed of two or more kinds of residues, the crystallization of the polyester resin (A) can be lowered, so that the heat shrinkable film. It is possible to suppress the progress of crystallization of the resin and impart sufficient heat shrinkage characteristics.

Examples of the dicarboxylic acid residue include terephthalic acid, isophthalic acid, frangicarboxylic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stylbenzicarboxylic acid, 4, 4-biphenyldicarboxylic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bisbenzoic acid, bis (p-carboxyphenyl) methane, anthracendicarboxylic acid, 4,4-diphenylether dicarboxylic acid, Aromatic dicarboxylic acid residues such as 4,4-diphenoxyetanedicarboxylic acid, 5-Nasulfoisophthalic acid, ethylene-bis-p-benzoic acid, dimer acid, hydrogenated dimer acid, adipic acid, sebacic acid, succinic acid. , Azelaic acid, dodecanedioic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and other aliphatic dicarboxylic acid residues, or residues derived from their ester derivatives and the like. These dicarboxylic acid residues may contain one kind alone or two or more kinds. Above all, it is preferable that the polyester resin (A) contains a terephthalic acid residue as a dicarboxylic acid residue.

Examples of the diol residue include ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, and spiroglycol. Examples thereof include 2,2,4,4-tetramethyl-1,3-cyclobutanediol and isosorbide. One of these diol residues may be used alone, or two or more thereof may be used in combination.

The preferable polyester-based resin (A) used in the present invention is a polyethylene terephthalate-based resin containing a terephthalic acid residue as a first dicarboxylic acid residue and an ethylene glycol residue as a first diol residue (hereinafter, "PET-based"). "Resin"), a polytrimethylene terephthalate resin containing a terephthalic acid residue as a first dicarboxylic acid residue and a 1,3-propanediol residue as a first diol residue (hereinafter, "PTT resin"). It is called.). Further, it is preferable that the polyester resin (A) used in the present invention contains a PET resin and a PTT resin from the viewpoint of the rigidity of the heat-shrinkable film and the perforation cutability, and the polyester resin (A) is preferable. It is particularly preferable that it consists only of a PET-based resin and a PTT-based resin.

[PET resin]
The PET-based resin is essential to contain a terephthalic acid residue as the first dicarboxylic acid residue, but may contain a second or lower dicarboxylic acid residue. The second or lower dicarboxylic acid residue includes at least one residue selected from the group consisting of isophthalic acid, frangylcarboxylic acid, dimer acid, hydrogenated dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and adipic acid. Is preferable, and it is more preferable to include an isophthalic acid residue as the second or lower dicarboxylic acid residue.

When the PET-based resin is composed of two or more types of dicarboxylic acid residues, the total content of the second and lower dicarboxylic acid residues is 1 mol% or more and 40 with respect to 100 mol% of all dicarboxylic acid residues. It is preferably 1 mol% or less, and more preferably 5 mol% or more and 35 mol% or less. When the total content of the second and lower dicarboxylic acid residues is equal to or higher than the above value, the crystallinity of the obtained PET-based resin can be suppressed to a low level, and the shrinkage of the heat-shrinkable film can be improved. There is. Further, when the total content of the second and lower dicarboxylic acid residues is not more than the above numerical value, the heat resistance of the PET resin tends to be less likely to be impaired.

Further, although it is essential that the PET-based resin contains an ethylene glycol residue as the first diol residue, it is preferable that the PET-based resin contains a second or lower diol residue.
Examples of the second and lower diol residues include 1,3-propanediol, 1,4-butanediol, neopentyl glycol, diethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, spiroglycol, 2,2. It preferably contains at least one residue selected from the group consisting of 4,4-tetramethyl-1,3-cyclobutanediol and isosorbide, and the second and lower diol residues are 1,4-cyclohexanedimethanol residues, It is more preferable to contain at least one selected from neopentyl glycol residues, 1,3-propanediol residues, 1,4-butanediol residues, and diethylene glycol residues.

When the PET-based resin is composed of two or more types of diol residues, the total content of the second and lower diol residues is 1 mol% or more and 45 mol% or less with respect to 100 mol% of all diol residues. It is preferably 10 mol% or more and 40 mol% or less. When the total content of the second and lower diol residues is equal to or higher than the above value, the crystallinity of the obtained PET-based resin can be suppressed to a low level, and the shrinkage and fracture resistance of the heat-shrinkable film can be improved. Tend to be able to. Further, when the total content of the second and lower diol residues is not more than the above numerical value, the heat resistance and chemical resistance of the PET resin tend to be less likely to be impaired.

The glass transition temperature of the PET-based resin can be determined according to the composition and ratio of the second and lower dicarboxylic acid residues and the second and lower diol residues, but is 40 ° C. or higher and 85 ° C. or lower. Is preferable.
In the present invention, the glass transition temperature is determined by raising the temperature of about 10 mg of the resin from 0 ° C. to 280 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC) and holding the resin at 280 ° C. for 1 minute. In the thermogram profile measured when the temperature is lowered to 0 ° C. at a cooling rate of 10 ° C./min and then re-heated to 280 ° C. at a heating rate of 10 ° C./min, the baseline shift portion at the time of re-heating is Intermediate temperature (° C). Further, the glass transition temperature of the resin of the example described later is also a value when measured in the same manner.

Further, the PET-based resin is preferably contained in an amount of 50% by mass or more, more preferably 60% by mass or more, and more preferably 70% by mass or more, when the total of the polyester-based resin (A) is 100% by mass. It is even more preferable. The upper limit of the content of the PET-based resin is usually 100% by mass.
When the PET-based resin is contained in the polyester-based resin (A) at a value equal to or higher than the above value, it tends to be possible to impart suitable shrinkage characteristics as a heat-shrinkable film.
As the PET-based resin, one kind may be used alone, or two or more kinds of PET-based resins may be used. When the PET-based resin is composed of two or more types, the total is the mass of the PET-based resin, and the mass ratio of the PET-based resin in the polyester-based resin (A) is calculated.

Examples of commercially available PET-based resins include "PETGcoplyester" (manufactured by Eastman Chemical Company), "Embrace" (manufactured by Eastman Chemical Company), and "PETGSKYGREEN" (manufactured by SK Chemical Company).

[PTT resin]
The PTT-based resin is essential to contain a terephthalic acid residue as the first dicarboxylic acid residue, but may contain a second or lower dicarboxylic acid residue. As the second or lower dicarboxylic acid residue copolymerizable with the PTT-based resin, those listed as the above-mentioned dicarboxylic acid residues can be used.

The total content of the second and lower dicarboxylic acid residues contained in the PTT-based resin is preferably 40 mol% or less with respect to 100 mol% of all the dicarboxylic acid residues constituting the PTT-based resin, and is 35. It is more preferably mol% or less. The lower limit is usually 0 mol%. When the total content of the second and lower dicarboxylic acid residues is in the range of the above numerical values, it is preferable because the glass transition temperature of the PTT-based resin is not extremely lowered. In addition, orientation crystallization is likely to occur during stretching, which contributes to improving the rigidity of the heat-shrinkable film, which is preferable.

The PTT-based resin is essential to contain a 1,3-propanediol residue as the first diol residue, but may contain a second or lower diol residue. As the second or lower diol residue copolymerizable with the PTT-based resin, those listed in the above-mentioned diol residue can be used.

The total content of the second and lower diol residues contained in the PTT-based resin is preferably 45 mol% or less, preferably 40 mol%, based on 100 mol% of all diol residues constituting the PTT-based resin. The following is more preferable. The lower limit is usually 0 mol%. When the total content of the second and lower diol residues is in the range of the above numerical values, it is preferable because the glass transition temperature of the PTT-based resin is not extremely lowered. In addition, orientation crystallization is likely to occur during stretching, which contributes to improving the rigidity of the heat-shrinkable film, which is preferable.

Among them, as the PTT-based resin used in the present invention, a PTT-based resin consisting of only a terephthalic acid residue as a dicarboxylic acid residue and a 1,3-propanediol residue as a diol residue is preferable.

The weight average molecular weight (Mw) of the PTT-based resin is preferably 40,000 or more and 400,000 or less, more preferably 50,000 or more and 300,000 or less, and further preferably 60,000 or more and 200,000 or less. The number average molecular weight (Mn) of the PTT resin is preferably 5,000 or more and 200,000 or less, more preferably 10,000 or more and 150,000 or less, and further preferably 20,000 or more and 100,000 or less. The ratio (Mw / Mn value) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 1.0 or more from the viewpoint of molding processability, and 5.5 from the viewpoint of mechanical characteristics. The following is preferable, more preferably 1.3 to 4.5, still more preferably 1.6 to 4.0. The weight average molecular weight (Mw) and the number average molecular weight (Mn) are obtained from polystyrene-equivalent molecular weights measured by GPC (gel permeation chromatography).

The reduced viscosity of the PTT-based resin is preferably 0.50 dL / g or more from the viewpoint of mechanical properties, preferably 1.70 dL / g or less from the viewpoint of molding processability, and more preferably 0. It is .60 to 1.60 dL / g, more preferably 0.70 to 1.50 dL / g. The reduced viscosity can be measured using a chloroform solution of 0.5 dL / g and a Ubbelohde type viscosity tube under the condition of a temperature of 30 ° C.

The glass transition temperature and melting point of the PTT-based resin can be determined according to the composition and ratio of the second and lower dicarboxylic acid residues and the second and lower diol residues that are composed, and the glass of the PTT-based resin. The transition temperature is preferably 40 ° C. or higher and 60 ° C. or lower. The melting point of the PTT resin is preferably 180 ° C. or higher and 260 ° C. or lower, and more preferably 200 ° C. or higher and 240 ° C. or lower.
Here, the glass transition temperature of the PTT-based resin can be obtained by the same method as described above.
The melting point in the present invention is the crystal melting peak temperature (Tm) (° C.) at the time of re-heating in the thermogram profile when the same measurement as the above-mentioned glass transition temperature is performed. Further, the glass transition temperature and the melting point of the resin of the examples described later are also the values when measured in the same manner.

Further, the PTT-based resin preferably contains 55% by mass or less, more preferably 50% by mass or less, and 45% by mass or less, when the total of the polyester-based resin (A) is 100% by mass. It is even more preferable.
When the PTT-based resin is contained in the polyester-based resin (A) in an amount equal to or less than the above-mentioned numerical value, it tends to be possible to impart suitable hand-cutting property as a heat-shrinkable film.
As the PTT-based resin, one kind may be used alone, or two or more kinds of PTT-based resins may be used.
When the PTT-based resin is composed of two or more types, the total is the mass of the PTT-based resin, and the mass ratio of the PTT-based resin in the polyester-based resin (A) is calculated.

Examples of commercially available PTT-based resins include "Sorona" (manufactured by DuPont Specialty Products Co., Ltd.) and the like.

Further, it is preferable that at least one of the dicarboxylic acid residue and the diol residue constituting the polyester resin (A) contains a residue derived from biomass. In particular, it is preferable that at least one of the terephthalic acid residue, which is a dicarboxylic acid residue, and the 1,3-propanediol residue, which is a diol residue, is a residue derived from biomass. Since the polyester resin (A) contains residues derived from biomass, there is a tendency that the heat-shrinkable film can be thinned and the utilization of petroleum-derived resources can be reduced.

If the polyester-based resin (A) is contained as a main component in the resin composition (Z) used in the present invention, various exemplified polyester-based resins (A) can be used, and their preferable contents are shown. However, when two or more types of polyester resin (A) are used in combination, an ester exchange reaction occurs in the molten state during molding, so identification of the content ratio of each resin and determination of whether it is a mixture or a copolymer May be difficult.
Therefore, in the resin composition (Z), the characteristics as a heat-shrinkable film can be scrutinized depending on the type of the residue contained in the resin composition (Z) and the content of the residue.

In the present invention, it is preferable that the resin composition (Z) contains a terephthalic acid residue as a dicarboxylic acid residue. The terephthalic acid residue is preferably contained in an amount of 75 mol% or more, more preferably 80 mol% or more, and more preferably 85 mol, based on 100 mol% of the total dicarboxylic acid residue contained in the resin composition (Z). It is more preferable that it is contained in% or more. The upper limit is usually 100 mol%. When the terephthalic acid residue is contained in an amount equal to or higher than the above value, the heat resistance and rigidity required for the heat-shrinkable film tend to be maintained.

In the present invention, it is preferable that the resin composition (Z) contains an ethylene glycol residue as a diol residue. Ethylene glycol residues are preferably contained in an amount of 25 mol% or more and 75 mol% or less, more preferably 30 mol% or more and 70 mol% or less, based on 100 mol% of all diol residues contained in the resin composition (Z). It is more preferable that it is contained in an amount of 35 mol% or more and 65 mol% or less. When the ethylene glycol residue contained is within the above numerical range, the heat resistance and chemical resistance required for the heat-shrinkable film tend to be maintained.

In the present invention, the resin composition (Z) has 1,4-cyclohexanedimethanol residue, neopentyl glycol residue, 1,3-propanediol residue, and 1,4-butanediol residue as diol residues. , It is preferable to contain at least one selected from diethylene glycol residues. It is preferable that these diol residues are contained in an amount of 10 mol% or more and 70 mol% or less, and 15 mol% or more and 68 mol% or less, based on 100 mol% of all diol residues contained in the resin composition (Z). It is more preferable that the content is 20 mol% or more and 65 mol% or less. When these glycol residues are within the above numerical range, 1,4-cyclohexanedimethanol residue, neopentyl glycol residue, 1,3-propanediol residue, 1,4-butanediol residue, and diethylene glycol are used. When at least one selected from the residues is within the above numerical range, it tends to be possible to maintain the heat resistance and chemical resistance required for the heat-shrinkable film.

In the present invention, 1,3-propanediol is preferably contained in an amount of 1 mol% or more and 45 mol% or less, and 5 mol% or more and 40, based on 100 mol% of all diol residues contained in the resin composition (Z). It is more preferably contained in an amount of 10 mol% or less, and particularly preferably contained in an amount of 10 mol% or more and 35 mol% or less. When the 1,3-propanediol residue is within the above numerical range, the heat-shrinkable film tends to have improved rigidity and perforated hand-cutting property.

When the resin composition (Z) contains 1,4-cyclohexanedimethanol residues, 1,4-cyclohexanedimethanol is added to 100 mol% of all diol residues contained in the resin composition (Z). It is preferable that the residue is contained in an amount of 5 mol% or more and 40 mol% or less, and more preferably 10 mol% or more and 35 mol% or less.

When the resin composition (Z) contains neopentyl glycol residues, the neopentyl glycol residues are 5 mol% or more and 40% based on 100 mol% of all diol residues contained in the resin composition (Z). It is preferably contained in an amount of 10 mol% or less, and more preferably contained in an amount of 10 mol% or more and 35 mol% or less.

When the resin composition (Z) contains 1,4-butanediol residues, the 1,4-butanediol residues are based on 100 mol% of the total diol residues contained in the resin composition (Z). Is preferably contained in an amount of 3 mol% or more and 25 mol% or less, and more preferably 6 mol% or more and 20 mol% or less.

When the resin composition (Z) contains diethylene glycol residues, the diethylene glycol residues are 0.5 mol% or more and 5 mol% with respect to 100 mol% of all diol residues contained in the resin composition (Z). It is preferably contained below, and more preferably 1 mol% or more and 4 mol% or less.

Further, it is preferable that the resin composition (Z) contains a residue derived from biomass from the viewpoint of reducing the utilization of resources derived from petroleum, and the residue derived from biomass includes a terephthalic acid residue and 1,3-. It is more preferable to include at least one of the propanediol residues, and it is particularly preferable to include a terephthalic acid residue and a 1,3-propanediol residue as biomass-derived residues.

(Other ingredients)
The resin composition (Z) may contain other resins as long as the polyester resin (A) is contained as a main component, but the resin composition (Z) contains only the polyester resin (A). Is preferable.
Other resins include polyolefin resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, chlorinated polyethylene resins, polycarbonate resins, polyamide resins, ethylene vinyl alcohol copolymers, and ethylene acetate. Vinyl copolymer, polymethylpentene resin, polyvinyl alcohol resin, cyclic olefin resin, polyacrylonitrile resin, polyethylene oxide resin, cellulose resin, polyimide resin, polyurethane resin, polyphenylene sulfide resin, polyvinyl Acetal resin, Polybutene resin, Polyamideimide resin, Polyamide bismaleimide resin, Polyarylate resin, Polyetherimide resin, Polyether ether ketone resin, Polyether ketone resin, Polyether sulfone resin, Polyketone Examples thereof include based resins, polysulfon based resins, aramid resins, and fluororesins. These may be used alone or in combination of two or more.

Further, the resin composition (Z) may contain a thermoplastic elastomer, and examples of the thermoplastic elastomer that can be contained include a styrene-based thermoplastic elastomer, an amide-based thermoplastic elastomer, and an olefin-based thermoplastic elastomer. , Urethane-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, fluorine-based thermoplastic elastomers, silicone-based thermoplastic elastomers, ionomers, and blends, alloys, modified products, and dynamic cross-linking products thereof. , Block copolymer, graft copolymer, random copolymer, core-shell type multilayer structure rubber and the like. These may be used alone or in combination of two or more. However, since the ester-based thermoplastic elastomer has an ester bond in the main chain, it is included in the polyester-based resin (A).

Further, to the resin composition (Z), additives generally blended in the resin composition can be appropriately added as long as the effects of the present invention are not significantly impaired. Examples of the additive include recycled resins generated from trimming loss of ears and the like, silica, talc, kaolin, etc., which are added for the purpose of improving and adjusting the molding processability, productivity and various physical properties of the heat-shrinkable film. Inorganic particles such as calcium carbonate, pigments such as titanium oxide and carbon black, flame retardants, weather resistance stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, cross-linking agents, lubricants, nucleating agents, plasticizers, anti-aging agents. Additives such as agents, antioxidants, light stabilizers, UV absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, colorants and the like can be mentioned. These may be used alone or in combination of two or more.

The resin composition (Z) used in the present invention can be obtained by using the polyester-based resin (A) as a main component and blending other components as necessary.

(Crystal melting heat (ΔHm))
The amount of heat of crystal melting (ΔHm) when the temperature of the resin composition (Z) is raised at 10 ° C./min using differential scanning calorimetry is preferably 1 J / g or more and 35 J / g or less. More preferably, it is 2 J / g or more and 30 J / g or less. When the amount of heat of crystal melting (ΔHm) is equal to or higher than the above value, heat resistance tends to be imparted. Further, when the value is not more than the above value, the film tends to be imparted with heat shrinkage.

Here, the amount of heat of crystal melting (ΔHm) is obtained when the temperature of the resin composition (Z) of about 10 mg is raised to 0 ° C. to 280 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC). It is calculated from the area of the crystal melting peak measured in.
At this time, when two or more crystal melting peaks are observed, the total amount of heat of crystal melting calculated from each peak area is the amount of heat of crystal melting of the resin composition (Z) used for the heat-shrinkable film of the present invention. It becomes (ΔHm).
Further, in the heating process of the differential scanning calorimeter (DSC), an endothermic peak (cold crystallization peak) associated with crystallization may be observed at a temperature lower than the crystal melting peak. When a cold crystallization peak is observed together with a crystal melting peak, the heat of crystal melting (ΔHm) of the heat-shrinkable film of the present invention is a value obtained by subtracting the heat of cold crystallization from the heat of crystal melting obtained by measurement.
The amount of heat of crystal melting of the resin composition (Z) of the examples described later is also a value when measured in the same manner.

[Manufacturing method of heat-shrinkable film]
The heat-shrinkable film of the present invention can be produced by a conventionally known production method using the resin composition (Z). Further, the form of the heat-shrinkable film of the present invention is not particularly limited and may be flat or tubular, but productivity (several pieces can be taken as a product in the width direction of the raw film) and From the viewpoint of ease of printing, a flat form is preferable.

As a method for producing the flat film, for example, the resin composition (Z) is melted using an extruder, the molten resin is extruded flat from a base such as a T-die, and the resin composition is cooled and solidified by a cooling roll. After obtaining the unstretched film, the obtained unstretched film is stretched in at least one direction, and then annealed, cooled, and if necessary, corona discharge treatment is performed to obtain a planar heat-shrinkable film. The manufacturing method can be mentioned.

Further, the resin composition (Z) is melted using an extruder, the molten resin is extruded into a tube shape from a base such as a round die, cooled and solidified by an air cooling device or a water cooling device to obtain an unstretched film, and then a tube is obtained. Internal pressure is applied to the tube in a tunnel furnace heated by the Ra method, and the tube is stretched in at least one direction by inflating it into a balloon shape, and then annealed and cooled tube-shaped stretched film is cut open to form a flat film. It can also be manufactured.

Since the heat-shrinkable film of the present invention may have at least one layer made of the resin composition (Z) containing the polyester resin (A) as a main component, for example, a plurality of extruders may be used together. By extruding, a laminated film having other layers can be produced in the same manner.

Examples of the stretching method include a method of stretching in at least one direction by a roll stretching method, a tenter stretching method, a tubular stretching method, a long-interval stretching method, or the like. Further, the stretching may be performed by a combination of these stretching methods, may be stretched only in the vertical direction, may be stretched only in the horizontal direction, or may be stretched in the vertical direction and then in the horizontal direction. , After stretching in the horizontal direction, it may be stretched in the vertical direction. Further, it may be stretched twice or more in the same direction. Further, it may be stretched in the vertical direction, then stretched in the horizontal direction, and further stretched in the vertical direction. Further, the simultaneous biaxial stretching machine may simultaneously stretch in the vertical direction and the horizontal direction. Further, the tubular unstretched film may be radially stretched by internal pressure by tubular molding.

The stretching temperature needs to be changed depending on the softening temperature of the resin constituting the heat-shrinkable film, the shrinkage characteristics required for the heat-shrinkable film, etc., but is preferably 60 ° C. or higher and 130 ° C. or lower, and 70 ° C. or higher and 120 ° C. The temperature is more preferably 80 ° C or higher, and further preferably 80 ° C or higher and 110 ° C or lower.

Further, the draw ratio needs to be changed depending on the constituent components of the heat-shrinkable film, the draw method, the draw temperature, the required heat shrinkage rate, etc., but the draw ratio in the main shrinkage direction may be 2 times or more and 8 times or less. It is preferable that it is 3 times or more and 7 times or less, and more preferably 4 times or more and 6 times or less.

When the heat-shrinkable film of the present invention is used for applications such as overlapping of containers and trays, it is preferably stretched in the vertical direction and the horizontal direction. At this time, the main contraction direction may be the vertical direction or the horizontal direction. Further, when used for applications that require shrinkage characteristics in almost one direction, such as labels attached to food containers and beverage containers, it is preferable to stretch them in one axis in the main shrinkage direction. Stretching in a direction orthogonal to the main shrinkage direction (hereinafter, also referred to as “orthogonal direction”) at a stretching ratio of 1.03 times or more and 1.5 times or less is also effective in imparting good shrinkage characteristics. Become a target.
Further, in the heat-shrinkable film of the present invention, it is preferable that the main shrinkage direction is the horizontal direction (TD) and the orthogonal direction is the vertical direction (MD).

After stretching, heat treatment or relaxation treatment can be performed at a temperature of 50 ° C. or higher and 120 ° C. or lower, if necessary, for the purpose of adjusting the heat shrinkage rate and various physical properties of the heat-shrinkable film. Further, after stretching, heat treatment, or relaxation treatment, the heat-shrinkable film can be imparted with shrinkage characteristics by rapidly cooling within a time in which the molecular orientation is not relaxed. Further, the cooled heat-shrinkable film can be formed into a film roll by trimming the ears and the like and winding the heat-shrinkable film around the core using a winder or the like.

[Layer structure of heat-shrinkable film]
The heat-shrinkable film of the present invention may have at least one layer (hereinafter referred to as "layer (I)") made of the resin composition (Z) containing the polyester resin (A) as a main component. .. Therefore, the heat-shrinkable film of the present invention may be a single-layer film of the layer (I) or a film in which the layer (I) and another layer (II) are laminated. The resin composition constituting the layer (II) is preferably a resin composition containing the polyester resin (A) as a main component. Further, the layer structure is not particularly limited.

When the heat-shrinkable film of the present invention is a heat-shrinkable film composed of at least two layers of the layer (I) and the other layer (II), the layer (I) and the layer (II) are adjacent to each other. It is more preferable that the resin composition having two continuous layer portions and constituting the layer (II) is a resin composition containing the polyester resin (A) as a main component.
The resin composition having a continuous layer portion in which the layer (I) and the layer (II) are adjacent to each other and constituting the layer (II) is mainly the polyester resin (A). Since the resin composition is a component, delamination at the interface between the layer (I) and the layer (II) tends to be less likely to occur.

When the heat-shrinkable film of the present invention is a heat-shrinkable film composed of at least two layers of the layer (I) and the other layer (II), a suitable laminated structure is, for example, "layer (I) /". Two-layer structure consisting of "layer (II)", two types 3 consisting of "layer (I) / layer (II) / layer (I)" and "layer (II) / layer (I) / layer (II)" Layer structure, "layer (I) / layer (II) / layer (III)", "layer (II) / layer (I) / layer (III)", "layer (III)" in which other layers (III) are further laminated (I) / layer (III) / layer (II) ", 3 types and 3 layers," layer (I) / layer (III) / layer (II) / layer (III) "," layer (III) / "Layer (I) / Layer (III) / Layer (II)", "Layer (III) / Layer (I) / Layer (II) / Layer (III)", 3 types and 4 layers, "Layer (I)" / Layer (III) / Layer (II) / Layer (III) / Layer (I) "," Layer (II) / Layer (III) / Layer (I) / Layer (III) / Layer (II) "," Layer (III) / Layer (II) / Layer (I) / Layer (II) / Layer (III) "," Layer (III) / Layer (I) / Layer (II) / Layer (I) / Layer (III) ) ”Can be adopted, and there are no particular restrictions on the number of layers or the above-mentioned other layer (III). Further, as the layer (III), another layer, for example, a layer made of non-woven fabric, paper, metal, or the like may be laminated.
Further, each layer may be laminated by coextrusion, or a film obtained in another step may be laminated by pressing, laminating or the like.

When the heat-shrinkable film of the present invention is a heat-shrinkable film composed of at least two layers of the layer (I) and the other layer (II), the resin composition constituting the layer (II) is the polyester. A resin composition containing the system resin (A) as a main component, from "layer (II) / layer (I) / layer (II)" and "layer (I) / layer (II) / layer (I)". It is preferable to have a two-kind, three-layer structure.

On the other hand, in the analysis of an unknown heat-shrinkable film, a resin having a continuous layer portion in which the layer (I) and the layer (II) are adjacent to each other and constituting the layer (II). When the composition is a resin composition containing the polyester resin (A) as a main component, the interface between the adjacent layer (I) and the layer (II) may not be clearly distinguished. Here, the fact that the interface between the adjacent layer (I) and the layer (II) cannot be clearly distinguished means that the cross section of the heat-shrinkable film is measured by a scanning electron microscope (SEM) or a transmission electron microscope (TEM). When the observation is performed, there is no contrast between the adjacent layer (I) and the layer (II), indicating a state in which the interface cannot be determined.
Therefore, in the analysis of an unknown heat-shrinkable film for determining whether it is included in the technical scope of the present invention, a continuous layer portion in which the layer (I) and the layer (II) are adjacent to each other is used. The resin having and constituting the layer (I) as the main component and the resin constituting the layer (II) as the main component are of the same type, and the interface between the adjacent layer (I) and the layer (II) is If it cannot be clearly distinguished, it is permissible to judge the layer (I) and the layer (II) as one layer in total.

The surface layer may be formed regardless of whether the heat-shrinkable film of the present invention is the layer (I) single-layer film or the laminated film consisting of at least two layers of the layer (I) and the layer (II). It is preferable to add an anti-blocking agent to the layer to be formed in order to impart slipperiness of the film and prevent blocking.

Examples of the anti-blocking agent include inorganic particles such as silica, talc and calcium carbonate, inorganic oxides and carbonates, and organic particles such as crosslinked acrylic, crosslinked polyester, crosslinked polystyrene and silicone. Be done. In addition, organic particles having a multi-layered structure polymerized in multiple stages can also be used. These may be used alone or in combination of two or more. Of these, silica and organic particles are preferable.

Since the anti-blocking agent develops slipperiness and blocking resistance by roughening the surface of the film, transparency and gloss of the film are impaired unless an appropriate addition amount and type are selected. Therefore, the amount of the anti-blocking agent added is preferably 0.01% by mass or more and 2% by mass or less, based on the total mass of the resin composition constituting the layer forming the surface layer (100% by mass). It is more preferably 0.015% by mass or more and 1.5% by mass or less, and further preferably 0.02% by mass or more and 1% by mass or less. When the amount of the anti-blocking agent added is too small, it is difficult for the anti-blocking agent to precipitate on the film surface and it is difficult to form irregularities on the film surface, so that it tends to be difficult to exhibit sufficient slipperiness and blocking resistance. On the other hand, if the amount is too large, excessive unevenness on the film surface tends to occur, and transparency tends to be impaired due to surface roughness, and film rolls tend to be wound due to excessive slipperiness.

The shape of the anti-blocking agent is not particularly limited, but a spherical one is preferably used from the viewpoint of suppressing aggregation, uniformly dispersing, suppressing diffused reflection of transmitted light, and unevenness formed on the film surface. .. The average particle size of the antiblocking agent is preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 8 μm or less, and further preferably 1 μm or more and 6 μm or less. The average particle size can be obtained as an average value by observing, for example, 10 or more particles with a scanning electron microscope (SEM) and measuring the diameter of the particles. At that time, in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter is taken as the diameter of each particle. However, as the average particle size of the inorganic particles as a raw material, D50 based on the volume-based particle size distribution obtained by measuring by the laser diffraction / scattering type particle size distribution measurement method can be adopted.
If the particle size of the anti-blocking agent is too small, it is difficult to precipitate on the surface, and even the anti-blocking agent deposited on the surface tends to be difficult to impart sufficient unevenness to exhibit slipperiness and blocking resistance. .. On the other hand, if the particle size of the anti-blocking agent is too large, ink leakage or the like tends to occur when printing is performed on the heat-shrinkable film of the present invention to improve the design, and the appearance of the printed pattern tends to be impaired. The particle size distribution of the anti-blocking agent is not particularly limited, but it is preferable that the particle size distribution is narrow because of the harmful effects of the size of the particle size. If the particle size distribution becomes too wide, some may deviate from the above-mentioned particle size range.

The total thickness of the heat-shrinkable film of the present invention is not particularly limited, but from the viewpoint of application to packaging materials, it is preferably 5 μm or more and 200 μm or less, more preferably 7 μm or more and 150 μm or less, and 9 μm or more and 70 μm. The following is more preferable.
Further, when the heat-shrinkable film of the present invention is thinned, it is preferably 10 μm or more and 40 μm or less from the viewpoint of the balance between rigidity and strength when used as a packaging material.

Further, the heat-shrinkable film of the present invention can be subjected to surface treatment and surface treatment such as slitting, corona treatment, printing, adhesive coating, coating, and thin film deposition, as well as bag making by various solvents and heat seals, if necessary. Processing and perforation processing can be performed.

[Physical characteristics of heat-shrinkable film]
The heat-shrinkable film of the present invention is a heat-shrinkable film in which the birefringence ΔN of the heat-shrinkable film is 0.055 or more and 0.100 or less. Hereinafter, various physical properties of the heat-shrinkable film of the present invention will be described in detail.

(Birerefringence ΔN)
The heat-shrinkable film of the present invention needs to have a birefringence ΔN of 0.055 or more and 0.100 or less. The birefringence ΔN is preferably 0.055 or more and 0.095 or less, and more preferably 0.055 or more and 0.090 or less. When the birefringence ΔN is equal to or greater than the above value, the orientation required for the heat-shrinkable film to heat-shrink is imparted. Further, when the birefringence ΔN is equal to or less than the above value, excessive orientation in the main contraction direction is suppressed, and deformation of the adherend is less likely to occur during contraction. Further, when the heat-shrinkable film attached to the adherend is peeled off along the perforations, the propagation of tearing becomes less dependent on the orientation.

(Heat shrinkage of heat-shrinkable film)
The heat-shrinkable film of the present invention preferably has a heat-shrinkage rate of 45% or more in the main shrinkage direction when immersed in warm water at 100 ° C. for 10 seconds. Further, the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 100 ° C. for 10 seconds is more preferably 45% or more and 90% or less, and further preferably 50% or more and 80% or less.
Generally, a heat-shrinkable film is formed by covering an object to be covered such as a container to be mounted and then passing it through an atmosphere heated by a heater, hot air, steam, etc. in a relatively short time (a few seconds to a dozen seconds). , The heat-shrinkable film is shrunk and attached to the object to be coated. Therefore, the heat shrinkage rate of the heat-shrinkable film is an index for determining the adhesion to the object to be coated and the shape followability.
Therefore, when the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 100 ° C. for 10 seconds is equal to or higher than the above value, the heat shrinkable film can be sufficiently attached to the object to be coated within the shrinkage processing time. It can be judged that it can be done.

Further, the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 90 ° C. for 10 seconds is preferably 20% or more, more preferably 25% or more and 80% or less, and 30% or more and 75%. The following is more preferable.
Further, the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds is preferably 15% or more, more preferably 20% or more and 70% or less, and 25% or more and 60%. The following is preferable.
Further, the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 70 ° C. for 10 seconds is preferably 5% or more, more preferably 6% or more and 60% or less, and 8% or more and 55%. The following is preferable.
In the shrinkage step, before the heat-shrinkable film is completely coated on the object to be coated, the film may be slightly shrunk (preshrink) at a low temperature to fix the position of the film on the object to be coated. At that time, when the heat shrinkage rate at each temperature is within the above-mentioned preferable range, the film tends to be gradually shrunk to the object to be coated from a lower temperature.

Further, the heat shrinkage rate when immersed in warm water at 50 ° C. for 10 seconds is preferably 5% or less, more preferably 3% or less, in both the main shrinkage direction and the orthogonal direction. It is more preferably 0% or less, and most preferably 0% or less.
If the heat shrinkage rate when immersed in warm water at 50 ° C. for 10 seconds is larger than the above value, the natural shrinkage rate of the film is likely to increase, and the film is likely to be rolled up and squeezed when stored in a roll shape, or the end face of the roll. Tends to cause poor appearance.

Further, when used for applications that require shrinkage characteristics in almost one direction, such as labels attached to food containers and beverage containers, the orthogonal direction when immersed in warm water at 100 ° C. for 10 seconds. The heat shrinkage rate is preferably −5% or more and 15% or less, and more preferably −5% or more and 10% or less. Here, when the heat shrinkage rate shows a negative value, it means that the film expands in that direction.
When the heat shrinkage rate in the orthogonal direction when immersed in warm water at 100 ° C. for 10 seconds is within the above range, the characters and patterns printed on the heat shrinkable film are distorted when mounted on the object to be coated. Tends to be able to suppress. Further, it is preferable to expand or contract in the orthogonal direction because it brings about an ironing effect that alleviates wrinkles generated at the time of mounting.

Further, when used for applications that require shrinkage characteristics in almost one direction, such as labels attached to food containers and beverage containers, orthogonality when immersed in warm water at 70 to 90 ° C. for 10 seconds. The heat shrinkage rate in the direction is preferably −5% or more and 10% or less, and more preferably −5% or more and 7% or less.
When the heat shrinkage rate in the orthogonal direction when immersed in warm water at 70 to 90 ° C. for 10 seconds is within the above range, the characters and patterns printed on the heat shrinkable film can be printed on the object to be coated. There is a tendency to suppress distortion. In addition, in fixing the position by pre-shrink, there is a tendency that the deviation of the fixed position can be suppressed.

(Surface orientation coefficient ΔP)
Further, in the heat-shrinkable film of the present invention, the surface orientation coefficient ΔP of the heat-shrinkable film is preferably 0.035 or more and 0.073 or less. Further, the plane orientation coefficient ΔP is more preferably 0.035 or more and 0.072 or less. When the surface orientation coefficient ΔP is equal to or higher than the above value, the orientation required for the heat-shrinkable film to shrink is imparted, which is preferable. Further, when the surface orientation coefficient ΔP is equal to or less than the above value, sufficient mechanical strength can be easily obtained even if the heat-shrinkable film is thinned, which is preferable.

(Tear strength)
Further, in the heat-shrinkable film of the present invention, the absolute value of the difference between the tear strength in the main shrinkage direction and the tear strength in the orthogonal direction is 11 N or less in the tear strength by the right-angle method based on JIS K7128-3 (1998). Is preferable. The absolute value of the difference in tear strength is preferably 10.5 N or less, and more preferably 10 N or less. When the absolute value of the difference in tear strength is less than or equal to the above value, the resistance of the force applied to the tear is reduced when the heat-shrinkable film attached to the adherend is peeled off, and the resistance of the force applied to the tear is reduced along the desired direction such as perforations. It is preferable because the heat-shrinkable film can be torn. Further, the lower limit of the absolute value of the difference in tear strength is preferably 1N or more.

The tear strength in the main contraction direction is preferably 3N or more, more preferably 6N or more, and even more preferably 9N or more. When the tear strength in the main shrinkage direction is 3N or more, the film is less likely to tear in each step such as the manufacturing process, the transporting process, and the mounting process of the heat-shrinkable film, which is preferable. Further, the tear strength in the orthogonal direction is preferably 4N or more, more preferably 7N or more, still more preferably 10N or more. It is preferable that the tear strength in the orthogonal direction is 4N or more because the film is not easily torn when the container on which the heat-shrinkable film is attached is unexpectedly dropped. The upper limit of the tear strength in the main contraction direction and the orthogonal direction is not particularly specified, but is usually 30 N or less.

Further, the ratio of the tear strength in the orthogonal direction to the tear strength in the main contraction direction (tear strength in the orthogonal direction / tear strength in the main contraction direction) is preferably 1.10 or more and 2.00 or less, and 1.20 or more and 1.90. The following is more preferable.

(Tension modulus)
From the viewpoint of the waist (rigidity at room temperature) of the film, the heat-shrinkable film of the present invention preferably has a tensile elastic modulus of 1750 MPa or more at an atmospheric temperature of 23 ° C. in the orthogonal direction, and more preferably 1800 MPa or more. It is preferably 1850 MPa or more, and more preferably 1850 MPa or more. The upper limit of the tensile elastic modulus in the orthogonal direction is not particularly limited, but the upper limit is preferably 4000 MPa or less in consideration of the upper limit of the tensile elastic modulus of the heat-shrinkable film normally used. If the tensile elastic modulus in the orthogonal direction is equal to or higher than the above value, the waist (rigidity at room temperature) of the film as a whole is high, and even when the thickness of the film is reduced, the heat-shrinkable film is labeled by the labeling machine. When the container is coated with such as, there is a tendency that processing defects such as breakage of the heat-shrinkable film are unlikely to occur.

(Tensile breaking strength)
The heat-shrinkable film of the present invention has a longitudinal (MD) tensile breaking strength of 35 MPa or more, measured in accordance with JIS K7127 (1999) under the conditions of an atmospheric temperature of 23 ° C. and a tensile speed of 200 mm / min. It is preferably 40 MPa or more, and more preferably 40 MPa or more. When the tensile breaking strength in the vertical direction (MD) is equal to or higher than the above value, problems such as breaking of the heat-shrinkable film tend to be less likely to occur in a secondary processing step such as a printing step.

(Tension breaking elongation)
The heat-shrinkable film of the present invention has a longitudinal (MD) tensile elongation at break of 100, measured in accordance with JIS K7127 (1999) under the conditions of an atmospheric temperature of 23 ° C. and a tensile speed of 200 mm / min. % Or more, more preferably 150% or more, and even more preferably 200% or more. When the tensile elongation at break in the vertical direction (MD) is equal to or higher than the above value, problems such as breakage of the heat-shrinkable film tend to be less likely to occur in a secondary processing step such as a printing step.

(Maximum contraction stress)
The heat-shrinkable film of the present invention preferably has a maximum shrinkage stress in the main shrinkage direction of 11 MPa or less, preferably 10.5 MPa or less, and more preferably 10 MPa or less when immersed in silicon oil at 100 ° C. for 10 seconds. On the other hand, the lower limit of the maximum shrinkage stress in the main shrinkage direction is preferably 3.5 MPa or more from the viewpoint of maintaining the adhesion between the object to be coated and the heat-shrinkable film. When the maximum shrinkage stress in the main shrinkage direction of the film is equal to or less than the above value, there is a tendency that the heat shrinkage of the heat-shrinkable film is less likely to deform the object to be coated.

(transparency)
The transparency of the heat-shrinkable film of the present invention is evaluated by the total light transmittance measured according to JIS K7631-1 (1997) and the haze value measured according to JIS K7331 (2000). The haze value is defined as the ratio of the diffuse transmittance to the total light transmittance.

The heat-shrinkable film of the present invention preferably has a total light transmittance of 87.5% or more, more preferably 88.0% or more, and even more preferably 88.5% or more. When the total light transmittance is equal to or higher than the above value, the transparency of the heat-shrinkable film is high, and the visibility of the container or backside printing tends to be improved.

Further, the heat-shrinkable film of the present invention preferably has a haze value of 10% or less, more preferably 9% or less, still more preferably 8% or less. When the haze value is not more than the above value, the heat-shrinkable film is less scattered, and the visibility of the contents and backside printing tends to be improved.

〔Packaging materials〕
The heat-shrinkable film of the present invention can be used for various purposes, but preferably, a printing layer is formed on one side or both sides of the heat-shrinkable film to form a plastic container such as a glass container or a PET bottle. It is possible to form a packaging material such as a heat-shrinkable label to be attached to the container.

Generally, on at least one of the front surface and the back surface of a heat-shrinkable film used for a label application, a printing layer or an overcoat layer is applied to at least one of the front surface and the portion by a known method such as gravure printing, flexographic printing, offset printing, and bar coater. Form. The printing ink is not particularly limited and may be appropriately selected depending on the printing method. Examples thereof include solvent-based (non-aqueous) or aqueous acrylic resin-based or urethane resin-based inks, foamable inks, and heat-foamable inks. Can be done.

Packaging materials for labels are processed into a flat shape, a cylindrical shape, or the like depending on the object to be packaged and used for packaging. For cylindrical containers such as PET bottles that require printing, first print the required image on one side of a wide flat film wound on a roll, and then cut this to the required width while printing on the printed side. It may be folded so that it is on the inside and center-sealed (the shape of the seal is a so-called envelope) to make it cylindrical. As the center sealing method, there are a sealing method using an organic solvent, a heat sealing method, an adhesive method, and an impulse sealer method, but the organic solvent sealing method is preferably used in consideration of the appearance.

[Molded products, containers]
The heat-shrinkable film of the present invention is excellent in waist (rigidity at room temperature), shrinkage finish, transparency, mechanical strength, etc. of the film, and has low natural shrinkage and shrinkage stress, so that it is attached to a molded product or a container. Even if it is a molded product or container with a complicated shape (for example, a cylinder with a constricted center, a square column with a corner, a pentagonal column, a hexagonal column, etc.), it can adhere to the shape without wrinkles or avatars. It can be used as a packaging material to be neatly attached. Therefore, various objects to which the heat-shrinkable film of the present invention is attached include, for example, PET bottles, plastic containers, metals, porcelain, glass, paper, bottles, trays, lunch boxes, delicatessen containers, dairy products containers, etc. Examples include molded products or containers having a different shape.
In particular, when the heat-shrinkable film of the present invention is used as a heat-shrinkable label for a blow bottle, even if it has a complicated shape as described above, it can adhere to the shape and is beautiful without wrinkles or avatars. It is particularly excellent in that a container with a label can be obtained.

Materials constituting the plastic container to which the packaging material of the present invention is mounted include polyethylene terephthalate, polystyrene, rubber-modified impact-resistant polystyrene (HIPS), styrene-butyl acrylate copolymer, styrene-acrylonitrile copolymer, and styrene. -Maleic anhydride copolymer, acrylonitrile-butadiene-styrene copolymer (ABS), methacrylic acid ester-butadiene-styrene copolymer (MBS), polyvinyl chloride resin, phenol resin, urea resin, melamine resin, epoxy Examples thereof include resins, unsaturated polyester resins, and silicone resins. These plastic containers may be a mixture of two or more kinds of resins or a laminated body.

Hereinafter, examples carried out for clarifying the effects of the present invention will be described. The present invention is not limited to the following examples and comparative examples. Further, in the following Examples, Comparative Examples, and Reference Examples, the flow direction of the heat-shrinkable film from the extruder is referred to as (MD), and the orthogonal direction of MD is referred to as (TD). The main shrinkage direction of the heat-shrinkable film in the examples is TD.
The following examples, the measured values shown in the comparative examples, and the evaluation were performed as follows.

(1) Birefringence ΔN and plane orientation coefficient ΔP measured by Abbe
According to JIS K7142 (2014), the refractive index of the obtained heat-shrinkable film was measured in the MD, TD, and thickness directions (THD) with an Abbe refractometer (contact liquid is methylene iodide). Using each index of _refraction ( _{NMD, NTD, and NTHD ) , birefringence ΔN = |} Was calculated.

(2) Heat shrinkage rate in the main shrinkage direction The obtained heat shrinkable film was cut into strips having a size of MD 10 mm and TD 200 mm, and marked lines with an interval of 100 mm with respect to TD. After that, the strip-shaped film was immersed in a hot water bath set at each temperature of 100 ° C., 90 ° C., 80 ° C., 70 ° C., and 50 ° C. for 10 seconds, and the marked line interval after shrinkage was measured, and the shrinkage amount (=). Marked line interval before contraction-marked line interval after contraction) was measured. The heat shrinkage rate was calculated as the ratio of the amount of shrinkage to the interval between marked lines before shrinkage (= (amount of shrinkage / interval between marked lines before shrinkage) × 100%).

(3) Tension elastic modulus According to JIS K7161-1 (2014), the obtained heat-shrinkable film was cut into a size of MD 200 mm and TD 5 mm, and the chuck distance was 150 mm, the tensile speed was 5 mm / min, and the atmospheric temperature was 23 ° C. The tensile elastic modulus of MD of the film was measured and the average value of the measured values of 5 times was calculated.
Further, the obtained heat-shrinkable film was cut into a size of TD 200 mm and MD 5 mm, and the tensile elastic modulus of the TD of the film at an atmospheric temperature of 23 ° C. was measured at a chuck interval of 150 mm and a tensile speed of 5 mm / min five times. The average value of the measured values was calculated.

(4) Tensile breaking strength and tensile breaking elongation The obtained heat-shrinkable film was cut into a size of MD120 mm and TD15 mm, and in accordance with JIS K7127 (1999), at a tensile speed of 200 mm / min and at an atmospheric temperature of 23 ° C. The tensile breaking strength and the tensile breaking elongation of the MD of the film were measured, and the average value of the measured values of 10 times was calculated.
Further, the obtained heat-shrinkable film was cut into a size of MD15 mm and TD120 mm, and according to JIS K7127 (1999), the tensile strength and tensile strength of the TD of the film at a tensile speed of 200 mm / min and an atmospheric temperature of 23 ° C. The elongation at break was measured, and the average value of the measured values of 10 times was calculated.

(5) Maximum shrinkage stress The obtained heat-shrinkable film was cut into a size of MD 10 mm and TD 70 mm, chucked at intervals of 50 mm, and fixed so that the load cell had no tarmi. Then, the sample piece was immersed in a silicon oil bath set at the measurement temperature for 60 seconds, and the maximum shrinkage stress in TD (film main shrinkage direction) was measured. The measurement temperature was 70 ° C., 80 ° C., 90 ° C., and 100 ° C.

(6) Total light transmittance, diffusion transmittance, haze The obtained heat-shrinkable film was measured for total light transmittance in accordance with JIS K7361-1 (1997). Moreover, the diffusion transmittance and the haze value were measured according to JIS K7316 (2000).

(7) Tear strength From the obtained heat-shrinkable film, a test piece of the right-angled tear method was collected according to JIS K7128-3 (1998), and the tear test of MD and TD was performed at a tensile speed of 200 mm / In minutes, the measurement was performed at an ambient temperature of 23 ° C., and the average value of the measured values of 5 times was calculated. From the calculated tear strength of MD and TD, the ratio of the tear strength of MD to the tear strength of TD (MD / TD) and the absolute value of the difference between the tear strength of MD and TD (| N _MD -N _TD |). Asked.

(8) Comprehensive evaluation In the above evaluation, those who meet all of the following criteria are marked with "○", and those who do not meet even one of the criteria are marked with "×".
[Evaluation criteria]
(I) Birefringence ΔN is 0.055 or more and 0.100 or less (ii) Thermal shrinkage rate in the main shrinkage direction when immersed in warm water at 100 ° C. for 10 seconds is 45% or more (iii) Tear strength of MD and TD The absolute value of the difference is 11N or less

The raw materials used in each reference example, example, and comparative example are as follows.
[Polyester resin (A)]
-Polyethylene terephthalate resin: 100 mol% of terephthalic acid residue as dicarboxylic acid residue, 65 mol% of ethylene glycol residue as diol residue, 32 mol% of 1,4-cyclohexanedimethanol residue, 3 diethylene glycol residue Polyester resin composed of mol%: glass transition temperature 78 ° C. (hereinafter abbreviated as "a-1")
Polytrimethylene terephthalate: 100 mol% terephthalic acid residue as a dicarboxylic acid residue, 100 mol% 1,3-propanediol residue derived from biomass as a diol residue, reduction viscosity 1.378 dL / g, weight average. Molecular weight Mw112,000, number average molecular weight Mn63,300, Mw / Mn = 1.76, glass transition temperature 49 ° C., melting point 228 ° C. (hereinafter abbreviated as "a-2").
[Masterbatch of anti-blocking agent]
Compound pellets (master batch) obtained by melt-kneading at a mixing ratio of 99% by mass of the above "a-1" and 1% by mass of spherical silica (average particle size 1 μm) (hereinafter, "a-3"). Abbreviated.)

<Example 1>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 94% by mass, "a-2" at a ratio of 5% by mass, and "a-3" at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 100 ° C., a stretching temperature of 88 ° C., and a heat treatment temperature of 90 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained.
The composition of the obtained heat-shrinkable film was analyzed and the residues were confirmed. The composition analysis was carried out by ¹ H-NMR measurement in the solvent CDCl ₃ . The results are shown in Table 1 below (hereinafter, the composition of the obtained heat-shrinkable film was analyzed in the same manner in Examples 2 to 8 and Comparative Examples 1 to 3. The results are shown in Table 1 below, respectively. .). The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 2>
An unstretched film having the formulation shown in Table 1 below was obtained by the same method as in Example 1. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 100 ° C., a stretching temperature of 88 ° C., and a heat treatment temperature of 83 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 3>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 84% by mass, "a-2" at a ratio of 15% by mass, and "a-3" at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 100 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 4>
An unstretched film having the formulation shown in Table 1 below was obtained by the same method as in Example 3. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 93 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 5>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 74% by mass, "a-2" at a ratio of 25% by mass, and "a-3" at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 98 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 6>
An unstretched film having the formulation shown in Table 1 below was obtained by the same method as in Example 5. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 83 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Example 7>
An unstretched film having the formulation shown in Table 1 below was obtained by the same method as in Example 5. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 93 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. Table 2 shows the results of evaluation of the obtained heat-shrinkable film.

<Example 8>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 59% by mass, "a-2" at a ratio of 40% by mass, and "a-3" at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 83 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Comparative Example 1>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 39% by mass, "a-2" at a ratio of 60% by mass, and "a-3" at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 83 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained.
Table 2 shows the results of evaluation of the obtained heat-shrinkable film.

<Comparative Example 2>
An unstretched film having the formulation shown in Table 1 below was obtained by the same method as in Comparative Example 1. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 95 ° C., a stretching temperature of 83 ° C., and a heat treatment temperature of 93 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

<Comparative Example 3>
According to the formulation shown in Table 1 below, "a-1" was mixed at a ratio of 99% by mass and "a-3" was mixed at a ratio of 1% by mass. In an extruder with a twin-screw extruder, conduit, merging block, and multi-manifold base joined, the mixed raw materials are supplied to the twin-screw extruder with a set temperature of 250 ° C., and melt-kneaded to 70. It was taken up with a cast roll at ° C. and cooled and solidified to obtain an unstretched film. Next, the obtained unstretched film was stretched to TD at a draw ratio of 5 times by a film tenter facility set to a preheating temperature of 100 ° C., a stretching temperature of 88 ° C., and a heat treatment temperature of 83 ° C., and heat-shrinked to a thickness of 30 μm. A sex film (packaging material) was obtained. The results of evaluation of the obtained heat-shrinkable film are shown in Table 2 below.

The heat-shrinkable films of Examples 1 to 8 include at least one layer made of a resin composition (Z) containing a polyester-based resin (A) containing a copolymerized polyester as a main component, and have a compounded rigidity ΔN of 0.055. When it is 0.100 or less, it has a sufficient heat shrinkage rate as a heat-shrinkable film, and the tensile elasticity of MD is 1850 MPa or more, and it can be seen that it has excellent rigidity. That is, even in the thinned heat-shrinkable film, since it has excellent rigidity, it is possible to obtain a heat-shrinkable film in which mounting failure does not easily occur even in the mounting process on the covering body. Further, the heat-shrinkable film has a birefringence ΔN adjusted to the range specified in the present invention, so that the anisotropy of the tear strength is small and the perforation is excellent in hand-cutting property. It can be seen that it is a heat-shrinkable film that promotes recycling because it can be easily detached from the covering body together with the consciousness of separation.

On the other hand, in the heat-shrinkable films of Comparative Example 1 and Comparative Example 2, at least one layer made of the resin composition (Z) containing the polyester-based resin (A) containing the birefringent polyester as the main component is formed as in the examples. Although the film contains layers, the birefringence ΔN is smaller than 0.055 and deviates from the range of the birefringence ΔN defined by the present invention, so that it can be seen that the film has an insufficient heat shrinkage rate in the main shrinkage direction.
Further, the heat-shrinkable film of Comparative Example 3 contains at least one layer made of the resin composition (Z) containing the polyester-based resin (A) containing the copolymerized polyester as the main component, as in the examples. Since the birefringence ΔN is larger than 0.100 and deviates from the range of the birefringence ΔN defined by the present invention, the maximum shrinkage stress is excessively large and the anisotropy of the tear strength is also large.

Although the present invention has been described above in relation to the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed in the present specification. It is possible to make appropriate changes within the scope of the claims and the gist of the invention that can be read from the entire specification, or to the extent that it does not contradict the idea, and the heat-shrinkable film with such changes is also included in the technical scope of the present invention. Must be understood as a thing.

Since the heat-shrinkable film of the present invention can obtain a heat-shrinkable film having excellent rigidity, heat-shrinkability, and perforation hand-cutting property, it can be used as a food packaging material, a beverage packaging material, or a pharmaceutical / medical packaging material. It can be suitably used for materials, packaging materials for chemicals, packaging materials for cosmetics, packaging materials for toiletries, industrial packaging materials, packaging materials for agricultural materials, and the like.

Claims (9)

A heat-shrinkable film having at least one layer made of a resin composition (Z) containing a polyester resin (A) as a main component.
The resin composition (Z) contains ethylene glycol residues and 1,3-propanediol residues as diol residues, and the total diol residues contained in the resin composition (Z) are 100 mol%. , Contains less than 65 mol% ethylene glycol residues
The tensile elastic modulus in the direction orthogonal to the main shrinkage direction of the heat-shrinkable film at an atmospheric temperature of 23 ° C. is 1750 MPa or more.
A heat-shrinkable film that satisfies the following a) and b).
a) The polyester resin (A) contains a copolymerized polyester resin b) Birefringence ΔN is 0.055 or more and 0.100 or less The heat-shrinkable film according to claim 1, which satisfies the following c) to e).
c) The plane orientation coefficient ΔP is 0.035 or more and 0.073 or less d) The amount of heat of crystal melting (ΔHm) when the temperature is raised at 10 ° C./min by the differential scanning calorimetry of the resin composition (Z). 1J / g or more and 35J / g or less e) The heat shrinkage rate in the main shrinkage direction when immersed in warm water at 100 ° C. for 10 seconds is 45% or more. Claim 1 or 2 in which the absolute value of the difference between the tear strength in the main contraction direction and the tear strength in the direction orthogonal to the main contraction direction is 11 N or less in the tear strength by the right-angle method according to JIS K7128-3 (1998). The heat shrinkable film according to the description. The heat-shrinkable film according to any one of claims 1 to 3, wherein the resin composition (Z) contains a terephthalic acid residue as a dicarboxylic acid residue. Claimed that the resin composition (Z) contains at least one selected as a diol residue from 1,4-cyclohexanedimethanol residue, neopentyl glycol residue, 1,4-butanediol residue, and diethylene glycol residue. Item 2. The heat-shrinkable film according to any one of Items 1 to 4 . The invention according to any one of claims 1 to 5 , wherein 1,3-propanediol is contained in an amount of 1 mol% or more and 45 mol% or less with respect to 100 mol% of all diol residues contained in the resin composition (Z). Heat shrinkable film. The heat-shrinkable film according to any one of claims 1 to 6 , wherein the resin composition (Z) contains a residue derived from biomass. A packaging material using the heat-shrinkable film according to any one of claims 1 to 7 . A molded product or container to which the packaging material according to claim 8 is attached.