JPH07330023A - Material for packing thermo-shrinkable molded item - Google Patents

Abstract

PURPOSE:To shrink a packing material with a promoter other than heat and execute appropriately a shrink packaging of a molded item shrinkable with heat as a promoter, by forming the packing material from a shrinkable molded product which shrinks in contact with humidity and shrinking it in a specified range of temperature. CONSTITUTION:A material for packing a thermo-shrinkable molded item packs the same item in response to heat. In this case, the packing material is made of a shrinkable molded product contracting in contact with humidity to shrink it in a range of 0-50 deg.C. The packing material is a stretched molded product made of a specified resin. The glass transition temperature of the specified resin is 50-300 deg.C at the absolutely dried state and the glass transition temperature lowers to 20 deg.C or lower with absorption of humidity and the strength in the absorbed state of humidity is more than 1kgf/mm<2> and the elongation thereof is more than 100. The draw ratio of the stretched molded product is 2-50 times in both MD and TD directions. The shape of packing material is a form like film, tube, or bag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material for shrink-wrapping a molded product which shrinks in response to heat.

[0002]

2. Description of the Related Art Conventionally, kraft paper, paper tubes, cardboard cases, etc. have been used as packaging materials for heat-shrinkable molded products (heat-shrinkable films, heat-shrinkable sheets, heat-shrinkable fibers, etc.).

[0003]

However, kraft paper has to be folded at the time of packaging, is labor-intensive, and it is difficult to say that it looks beautiful, and in some cases, the packaging material may impair the product image. On the other hand, paper tubes and corrugated cardboard cases are often used for packaging rolls of heat-shrinkable films or sheets,
Since it is bulkier than the main body of the molded product, there is a problem in that much waste occurs during distribution. As a packaging method for solving these problems, a method of closely packing a molded product using a shrinkable film or sheet is considered. However, since such a packaging method uses a film or sheet that shrinks in response to heat as a packaging material, it cannot be applied when the packaged item undergoes dimensional changes (shrinkage, etc.) due to heat. It was

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a heat-shrinkable molded product can be extremely easily formed by using a film or sheet that shrinks using factors other than temperature as a promoter. Moreover, they have found that they can be closely packaged efficiently, and have reached the present invention. That is, the present invention is a packaging material for a heat-shrinkable molded product, which is made of a resin molded product that contracts in contact with moisture and shrinks at a temperature of 0 to 50 ° C. The term "moisture" as used herein refers to all forms of moisture, from moisture to liquid water.

The coating material of the present invention comprises a resin molded product (A) which contracts in contact with moisture. Examples of the resin molded product include stretch molded products composed of the resin (A) adjusted so as to simultaneously satisfy the following conditions (A) to (C). (A) The glass transition temperature in an absolutely dry state is 50 to 300 ° C. (A) The glass transition temperature is lowered to 20 ° C. or lower by absorbing moisture. (C) The strength when absorbing moisture is 1 kgf / mm ² or more, and the elongation is 100% or more.

Examples of the resin (A) include the following (X1)
~ (X8) can be mentioned. (X1) Graft of hydrophilic resin and thermoplastic resin and /
Or a blocked product; a grafted product of a starch derivative and polymethyl acrylate (resin described in US Pat. No. 4839450), a grafted product of a cellulosic polysaccharide and a thermoplastic resin (described in JP-A-3-177431). Resin, etc.), grafted product of hydrophilic synthetic resin and thermoplastic resin (resin described in JP-A-3-37233), blocked product of hydrophilic synthetic resin and thermoplastic resin (JP-A-3-39331) Resins described above), polyamide modified products (for example, blocked products of one or more polyamides selected from the following a and one or more polyamides selected from b), polyester modified products (for example, one or more selected from the following c) And one or more blocked compounds selected from the following d) and the like. a. Water-insoluble polyamide having a glass transition point of 50 ° C or higher [nylon 46, nylon MXD6 (Mitsubishi Gas Chemical Co., Ltd.
Etc.] and modified products thereof. b. Water-soluble polyamide [Product name: AQ nylon (Toray
Ltd.), resin resin FS350, resin resin FS500
(All manufactured by Teikoku Chemical Industry Co., Ltd.) and its modified products, polyamide-based elastomers [Daiamide (manufactured by Daicel Chemical Co., Ltd.), Pelestat (manufactured by Sanyo Kasei Co., Ltd.)
Etc.] and modified products thereof. c. Polyester having a glass transition point of 50 ° C. or higher and its modified products. d. Polyesters containing hydrophilic groups and modified products thereof. (X2) a mixture of a hydrophilic synthetic resin and a thermoplastic resin; a mixture described in JP-A No. 03-37232, a polyamide modified product (for example, one or more polyamides selected from a and one or more polyamides selected from b). Blends, etc.), polyester modified products (for example, one or more blends selected from the above c and one or more blends selected from d), and the like. (X3) Hydrolyzate of vinyl ester (co) polymer; polyvinyl alcohol having saponification degree of 98 mol% or more (resin described in JP-A-57-160615), homopolymer of vinyl ester Resins and the like described in JP-A-5-177709]. (X4) Random copolymer containing vinyl ester and / or alkyl (meth) acrylate as a constituent unit;
Resins and the like described in JP-A-5-177708. (X5) Polyalkylene oxide modified product; for example, stretched molded product made of cross-linked polyalkylene oxide irradiated with ionizing radiation (the resin described in JP-A-05-42600) and the like. (X6) Copolymer of olefin and polymerizable monomer having hydrophilic group and / or modified product thereof ((partial) hydrolyzate, (partial) etherified product, (partial) esterified product, (partial)) Urethane compound, (partial) alkoxy compound,
(Partial) acetalized product, (partial) aminated product, (partial) amidated product, polymer reaction product, etc.]; for example, olefin (ethylene, propylene, butadiene, etc.) and the following g to
One or more copolymers with m and / or modified products thereof. g. Vinyl ester and / or its hydrolyzate Vinyl aliphatic organic acid ester monomer (vinyl formate, vinyl acetate, vinyl n-propionate, vinyl n-butyrate, vinyl versatate, vinyl hydroxyacetate, vinyl hydroxybutyrate, etc.) And / or a (co) polymer of at least one vinyl aromatic organic acid ester monomer (vinyl benzoate, vinyl p-methylbenzoate, etc.) and / or a hydrolyzate thereof. h. Vinylcarboxylic acid, its anhydride or its monovalent salt (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, or their monovalent salts [alkali metal (sodium, potassium, etc.) salts , Ammonium salts, amines (monomethylamine, dimethylamine, trimethylamine, triethanolamine) salts, etc.]. i. Vinyl sulfonic acid or its monovalent salt [alkali metal (sodium, potassium, etc.) salt, ammonium salt,
Amine (monomethylamine, dimethylamine, trimethylamine, triethanolamine) salt, etc.]. j. Hydroxyalkyl acrylate Hydroxyethyl (meth) acrylate, hydroxybutyl acrylate, etc. k. Allyl alcohol. l. Polyhydric alcohol monoallyl ether Ethylene glycol monoallyl ether, glycerin monoallyl ether, etc. m. Vinyl halide, vinyl chloride, vinylidene chloride, etc.

Of these resins, those other than (X5) may be appropriately crosslinked as long as the shrinkability is not impaired.

Of these, preferred are those having the compositions of (X1) and (X2), and particularly preferred are the modified polyamides and modified polyesters of (X1).

In the case of (A), the functional groups in the resin are appropriately modified as required within the range that does not adversely affect the performance [hydrolysis, etherification, esterification, cyanation, urethane formation, acetalization, Amination, amidation, halogenation,
Sulfonation, acylation, oxidation, reduction, partial modification with a coupling agent, etc.) may be carried out.

Specific methods of modification include, for example, the following methods. Hydrolysis: (K1) A resin (A) having a functional group such as an organic acid ester group, a sulfuric acid ester group, a phosphoric acid ester group, an ether group or an amide group and an acid catalyst (hydrochloric acid, sulfuric acid, organic acid, etc.) were used. Hydrolysis. (K2) Hydrolysis of a resin (A) having a functional group such as an ester group or an amide group by a base catalyst (hydroxide of alkali metal, hydroxide of alkaline earth metal, ammonium salt, amine salt, etc.). Etherification; (L1) The resin (A) having an alcoholic hydroxyl group is converted to an alkali metal alkoxide with an alkali metal hydroxide (sodium hydroxide, potassium hydroxide, etc.), and then an alkyl halide (methyl iodide, ethyl bromide, etc.) ) Is reacted with etherification. (L2) Resin (A) having a halogenated alkyl group and an alkali metal alkoxide (sodium methoxide, etc.)
Etherification by the reaction of. (L3) Etherification by reacting the resin (A) having active hydrogen with an alkylene oxide (ethylene oxide, propylene oxide, etc.). Esterification; (M1) Resin (A) having hydroxyl group and organic acid [formic acid,
Esterification by reaction with (anhydrous) acetic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid, monochloroacetic acid, (anhydrous) benzoic acid, etc.], an acid halide (acetic acid chloride, benzyl chloride) and the like. (M2) Resin (A) having a carboxylic acid group, a sulfonic acid group and a phosphoric acid group and alcohols (methanol, ethanol, isopropanol, ethylene glycol, glycerin, alkylene oxide adducts (polyethylene glycol, polypropylene glycol, ethylene oxide of polysaccharides (N1) (resin having hydroxyl group (A) and isocyanates [monoisocyanate (methyl isocyanate, butyl isocyanate, phenyl isocyanate, etc.), poly] Isocyanate (2,4-tolylene diisocyanate,
4,4′-diphenylmethane diisocyanate, dianisidine diisocyanate, tridene diisocyanate, hexamethylene diisocyanate, and derivatives thereof) to form a urethan. (N2) Resin (A) having a hydroxyl group and ureas (urea, N
-Urethane formation by reaction with ethylurea etc.). Acetalization: (O1) Acetalization by reacting the resin (A) having a hydroxyl group with aldehydes (formaldehyde, n-butyraldehyde, benzaldehyde, etc.). (O2) Resin (A) having an aldehyde group and organic matter [alcohols (methanol, ethanol, isopropanol, ethylene glycol, glycerin, alkylene oxide adducts (polyethylene glycol, polypropylene glycol, ethylene oxide adduct of polysaccharides, etc.)] Acetalization by reaction, etc. Amination; (P1) Reduction of resin (A) containing nitro group with metal catalyst (platinum, tin, etc.) (P2) Resin (A) having alkyl halide moiety and ammonia Amination by reaction (P3) Amination by reaction of resin (A) having carbonyl group with ammonia or amines (P4) Amination by reduction reaction of resin (A) having nitrile group, etc. Amidation (Q1) Resin (A) having amino group and acid halogen (Q2) Amidation by reaction of a resin (A) having an aromatic amine group with an acid anhydride (acetic anhydride, etc.) Halogenation; R1) Halogenation by the reaction of the resin (A) having a hydroxyl group with hydrogen halide (hydrogen iodide, hydrogen bromide, hydrogen chloride, etc.) (R2) The resin (A) having a hydroxyl group and phosphorus trihalide (three) Halogenation by reaction with phosphorus chloride, phosphorus tribromide, etc. (R3) Halogenation by reaction with resin (A) having hydroxyl group and thionyl chloride Sulfonation; (S1) Resin having aromatic ring (A) ) And sulfuric acid by reaction with acyl, etc. Acylation; (T1) Acylation by reaction between resin (A) having active hydrogen and acid halide, etc. Oxidation; (U1) Resin (A) Oxidation by reaction with various oxidizing agents (ozone, oxygen, hypohalite, permanganate, dichromate, etc.) Reduction: (V1) Resin (A) and various reducing agents (hydrogen, alkali metal) , Reduction by reaction with hydrogen peroxide, sodium borohydride, lithium aluminum hydride, etc. Partial modification with coupling agent; (W1) Resin (A) and silane coupling agent (tetraalkoxysilane, monoalkyltri) Modification by reaction with alkoxysilane, dialkylalkoxysilane, trialkylmonoalkoxysilane, etc. (W2) Modification by reaction of resin (A) with alkoxyaluminates (W3) Resin (A) with alkoxytitanates Denaturation by the reaction of.

Further, (A) has a glass transition temperature of 50 to 300 ° C. in an absolutely dry state. If the glass transition temperature in an absolutely dry state is less than 50 ° C, the storage stability may decrease (that is, even if the glass is stored with the moisture blocked, the storage stability may be reduced to about 30 to 80 ° C). When it is exposed to heat, it shrinks only in response to the temperature, which makes it unsuitable for use. On the other hand, when the glass transition temperature exceeds 300 ° C, molding becomes difficult or shrinkage decreases. There is. The absolutely dry state here means a state where the water content is less than 0.1%.

Further, (A) absorbs moisture (usually 0.1).
% Or more), the glass transition temperature is lowered to 20 ° C. or lower. Glass transition temperature of 20 due to moisture
If the temperature does not decrease to below 0 ° C, the shrinkage property at around room temperature may be poor, and in such a case, it is necessary to perform a heating operation at about 20 to 50 ° C.

Further, (A) shows a physical property such that the strength is 1 kg / mm ² or more and the elongation is 100% or more in a state of absorbing 0.1 to 5.0% of moisture. Strength is 1kg /
When it is less than mm ² and / or when the elongation is less than 100%, it is necessary to take measures such as using it in combination with another material.

The strength and elongation in this case are JIS-K
7113 (tensile test method for plastics) refers to the strength and elongation measured according to the test method.

Further, in order to adjust the glass transition temperature of (A) at the time of absolutely dry and at the time of absorbing moisture, for example, a method of adjusting the kind and ratio of functional groups in the resin; polymer of resin It can be appropriately adjusted as necessary by a method of adjusting the structure, molecular weight, etc .; a method of adding an additive to the resin; In this case, the glass transition temperature is JIS-
The glass transition temperature measured in accordance with the test method of K7121 (Plastic transition temperature measuring method).

In (A), a plasticizer, a foaming agent, a lubricant, a surfactant, a readily decomposable additive, an antistatic agent, a colorant, a filler, an inorganic substance (silica, zeolite, Activated carbon, far-infrared radiation ceramics, etc.), water absorbent resin, deodorant, fragrance, medicinal component, antibacterial agent, antifungal agent and the like.

The stretch-molded product of the present invention may be uniaxially stretched or biaxially stretched. The stretching ratio varies depending on the purpose of use and manufacturing method, but is usually MD direction, TD
The direction is 1.1 to 50 times. Further, the thickness of the molded product is not particularly limited and usually 10
~ 200μ.

The method for producing the packaging material of the present invention is not particularly limited, but for example, a method of producing a stretched tubular product by inflation molding of a resin adjusted to desired physical properties; adjustment to desired physical properties A method of forming the stretched film or a stretched sheet by a tenter method or the like after molding the resin thus obtained into a sheet by the T-die method or the casting method; A method of applying a solution or emulsion of a resin whose physical properties have been adjusted to the surface of a mold, and blowing the compressed gas or the like from the inside of the mold to inflate it to simultaneously perform mold release and stretching to obtain a molded product, and the like.

The shape of the packaging material of the present invention is not particularly limited as long as the functions such as shrinkability are not impaired.
Sheets, tubes, nets and bags are preferable, and among these, films, sheets and tubes are particularly preferable.

The packaging material of the present invention comprises a resin molded product [for example, a stretched molded product of resin (A)] that shrinks due to moisture,
If necessary, it can be formed by stacking with another material such as a plastic film. For example, (a) a coextruded product, (b) a laminated structure in which the stretched film and another plastic film are laminated by heat sealing, adhesion, etc., (c) the stretched film made of another nonwoven fabric or paper. And so on. If necessary, a pressure-sensitive adhesive or the like can be applied to one surface of the resin molded product for use.

The packaging material of the present invention usually has a relative humidity of 70%.
It can be instantly contracted by exposing it to the above conditions or spraying or immersing it in water, so that it can be easily carried out anywhere as long as there is moisture or water. In this case, the degree of shrinkage varies depending on the type of the packaging material or the material to be packaged, but is usually at least 1%, preferably 10% in the length direction in the temperature range of 0 to 50 ° C. under the above-mentioned humidity conditions.
~ 60%.

The packaging material of the present invention efficiently wraps only the packaging material at a temperature of 0 to 50 ° C. by roughly wrapping the article to be packaged (heat-shrinkable molded article) and then bringing moisture into contact with the packaging material. Shrink and shrink-wrap the heat-shrinkable molded product.

When the packaging material of the present invention is actually used, the heat-shrinkable molded product may be directly packaged or the heat-shrinkable molded product may be coated together with the treatment member. As a specific example of the former, for example, a heat-shrinkable film or sheet is covered with a large film-shaped packaging material of the present invention, and water is applied, or mist-like water is applied by spraying or the like to shrink and adhere. , Packaging methods, etc.

As a concrete example of the latter, a heat-shrinkable film of irregular shape and a cushioning material (styrofoam, urethane foam, etc.) are combined, and a large tube-shaped packaging material of the present invention is attached to these to surround it with water. Or multiply
Examples include a method of shrink-wrapping by applying mist-like water by spraying.

On the other hand, as a method of removing the packaging material after use,
Method of destroying and removing the packaging material as it is; Method of putting perforations in the packaging material beforehand and then destroying and removing it.
Examples include a method in which water is brought into contact with the packaging material after shrinkage again, and when it becomes soft, it is stretched and removed.

Since the packaging material for heat-shrinkable molded articles of the present invention can be shrunk in the temperature range of 0 to 50 ° C. as described above, it does not require a special device or technique and is complicated. It can also be easily applied to a heat-shrinkable shaped product.

In the packaging material of the present invention, various information is printed on the surface of the packaging material before shrinking by a method such as printing or writing, and then the packaging material is allowed to shrink, so that various information can be stored in a small space of the packaging material after shrinking. Can be packed. The packaging material can also be used by coloring it.

Since the packaging material of the present invention shrinks and comes into close contact, it may have a simple shape and can be made compact.

Since the packaging material of the present invention does not shrink unless it is re-stretched after the shrinking is completed, it is usually used for disposable applications.

[0030]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. The parts in the examples are parts by weight. The draw ratio and the shrinkage ratio were measured by the following methods. Stretching ratio: Inflation film (MD direction; ratio of take-up speed and extrusion speed from die TD direction; ratio of length in film TD direction and die lip diameter) Moisture shrinkage ratio: Each test film was left under various conditions The ratio of length before and after shrinkage in the longitudinal direction (longitudinal direction of the molded product) and the lateral direction (direction perpendicular to the longitudinal direction of the molded product) after completion of shrinkage.

Example 1 Water-soluble nylon [AQ nylon A-90; Toray Industries, Inc.
, Nylon MXD6 (manufactured by Mitsubishi Gas Chemical Co., Inc.), and a polyamide elastomer (Perestat; manufactured by Sanyo Kasei Co., Ltd.) are uniformly blended, and then the amide exchange reaction is performed in an extruder to obtain a glass transition temperature in an absolutely dry state. Above 50 ° C,
Moreover, the glass transition temperature decreases to 20 ° C. or less when absorbing moisture, the strength is 3.0 kgf / mm ² , and the elongation is 250%.
To obtain a resin that is Next, this resin was subjected to inflation molding (stretching ratio; MD direction 35 times, TD direction 2 times) to obtain a film-like packaging material of the present invention having a thickness of 20 μm. Using this packaging material, a roll-shaped heat-shrinkable film (made of polyvinyl chloride) wound around a paper tube having an outer diameter of 30 mm was roughly wrapped. Next, temperature 20 ℃, relative humidity 90
When this package is placed in a thermo-hygrostat adjusted to% RH, the packaging material shrinks quickly (shrinkage rate: 20% in the longitudinal direction, 20% in the lateral direction), and the roll-shaped heat-shrinkable film is easily adhered to the packaging. I was able to do it. In this work, the dimensional change of the packaging material was not observed at all immediately before the application of moisture, and the mounting work proceeded smoothly. After shrink wrapping,
When the packaging material was removed and the contents were confirmed, the heat-shrinkable film of the contents did not change at all.

Example 2 Water-soluble nylon [AQ nylon A-90; Toray Industries, Inc.
Manufactured by Mitsubishi Gas Chemical Co., Ltd., polycaprolactone [reagent; manufactured by Aldrich Chemical Company], and a reaction catalyst in an extruder under a nitrogen atmosphere at a glass transition temperature of 50 ° C. or higher. Yes,
Moreover, a co-polyamide-ester resin having a glass transition temperature of 20 ° C. or lower when absorbing moisture can be obtained very easily. (The strength and elongation of the produced resin when absorbing moisture were 1.8 kgf / mm ² and 230%, respectively.) This resin was film-formed by an extruder with a T-die, and then biaxially stretched. Machine [ss-6 manufactured by Shibayama Scientific Instruments Co., Ltd.
Type 0] stretching (stretching ratio; MD direction 40 times, TD direction 2
20 times the thickness of the stretched molded product. Two pieces of this molded product were overlaid and sealed on three sides to form a bag, thereby obtaining the packaging material of the present invention. Next, a heat shrinkable film made of polystyrene (A4 size) is folded and put in the bag-shaped packaging material of the present invention, and sprayed with mist-like water by mist blowing to shrink (shrinkage rate: vertical direction 35%, horizontal direction 20). %) It was made to adhere. The temperature in this case was 25 ° C., and no change in dimension of the molded product was observed until the moisture was applied, and the mounting operation proceeded smoothly. Furthermore, after the heat-shrinkable film after packaging was left outdoors at a temperature of 10 to 25 ° C. for 2 days, the shrink-adhesive packaging material was removed, and the condition of the heat-shrinkable film made of polystyrene, which was the content, was observed.
As such, it did not shrink at all, and no stain was observed.

Example 3 Polyvinyl alcohol (polymerization degree: 1600, saponification degree: 9)
(6.5%) aqueous solution, methyl acrylate was polymerized by a known method to obtain a mixture of polyvinyl alcohol and polymethyl acrylate. This mixture was dried and pulverized, then dissolved in dimethyl sulfoxide, and a uniform film was obtained by a casting method. This film was biaxially stretched by a tenter type stretching machine to obtain a film having a thickness of 20 μm (stretching ratio: vertical 2.5 times, horizontal 2.5 times). This film was cut and the ends were adhered by heat sealing to obtain a bag-shaped packaging material of the present invention. The heat-shrinkable label (made of polyester) was put in a bag-shaped packaging material, and shrink-wrapped (shrinkage rate: vertical direction 15%, horizontal direction 14%) in the same manner as in Example 1. After the shrink-wrapping was completed, the packaging material was removed and the contents were confirmed, but the heat-shrinkable label of the contents did not change at all.

Comparative Example 1 Commercially available polyethylene heat shrink film (thickness: 20 μm)
Was used, and a heat-shrinkable film (made of polyvinyl chloride) was shrink-wrapped in the same manner as in Example 1 except that a heat-shrinkable tunnel set at 150 ° C. was used during shrinkage. After the shrink-wrapping was completed, the polyethylene heat-shrink film of the packaging material was removed and the contents were checked, but the heat-shrink film had already shrunk, and the commercial value was lost.

[0035]

The packaging material for the heat-shrinkable molded article of the present invention is
It has the following effects. (1) Since the packaging material of the present invention shrinks by a promoter other than heat (temperature), a molded article (heat shrinkable film, heat shrinkable sheet, heat shrinkable label,
Suitable for shrink wrapping of expandable plastics such as EPS). (2) Since the packaging material of the present invention has high dimensional stability against heat, the covering work before shrinkage proceeds smoothly. (3) Since it shrinks rapidly in response to moisture and can be fit-fitted to the object to be fitted and shrink-wrapped, the mounting work is easy, and it is hard to come off after mounting and has a good appearance. (4) Since the object to be packaged can be closely packaged, it is possible to save space in the distribution of the object to be packaged. (5) Since it shrinks and shrinks and adheres in conformity with the shape of the object to be packaged, the shape may be simple at the time of manufacturing, and the manufacturing process can be simplified. (6) Since it contracts easily when it comes into contact with moisture, it can be used even if there is no special device such as a shrinking device as long as it has moisture (water). Because of the above effects, the molded product of the present invention is particularly useful for packaging a molded product that shrinks with heat.

Claims (4)

[Claims] 1. A packaging material for a heat-shrinkable molded article, which is made of a resin molded article that contracts in contact with moisture and shrinks at a temperature of 0 to 50 ° C. 2. The packaging material according to claim 1, which is a stretch-molded article made of a resin (A) adjusted so as to simultaneously satisfy the following conditions (A) to (C). (A) The glass transition temperature in an absolutely dry state is 50 to 300 ° C. (A) The glass transition temperature is lowered to 20 ° C. or lower by absorbing moisture. (C) The strength when absorbing moisture is 1 kgf / mm ² or more, and the elongation is 100% or more. 3. The stretch ratio of the stretch-molded product is in the MD direction,
The packaging material according to claim 2, which is a film that is 2 to 50 times in the TD direction. 4. A film-shaped, tube-shaped, or bag-shaped or a combination thereof.
The packaging material according to any one of to 3.