JP2000026624A - Adhering heat-resistant wrapping film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a film useful as a domestic wrapping film and capable of being easily disposed of by selecting an oriented film made from a composition containing a resin based on a glycolate aliphatic polyester resin having a specified crystalline melting point and a liquid additive in a specified ratio and specified in a tensile modulus, a heat shrinkage, heat shrinkage stress, etc. SOLUTION: There is provided an oriented film made from a composition 100 pts.wt. resin based on a glycolate aliphatic polyester (e.g. a resin prepared by copolymerizing glycolic acid with glycolic acid) having a crystalline melting point of 120-250 deg.C and 1-20 pts.wt. liquid additive (e.g. tetraglycerol monolaurate) and having a tensile modulus of 20-150 kg/mm2, a heat resistance of 120 deg.C or above, and an adhesiveness of 5-30 g.cm/25 cm2, and satisfying the relationships: Y<=(1,400-20X)/3, 2<=X<=45, and 5<=Y<=350 (wherein X% is the heat shrinkage at 100 deg.C, and Y g/mm2 is the heat shrinkage stress at 100 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant adhesive wrap film which is preferably used for packaging, especially as a household wrap film, although its use is not particularly limited.
However, if there is another application that effectively utilizes the characteristics of the present invention, the present invention is not limited to this, but the following description will be limited to the above-described wrap.

[0002]

2. Description of the Related Art A household wrap film is mainly used for preserving foods in a refrigerator or a freezer or for heating in a microwave oven by mainly overlapping foods in a container. For this reason, household wrap film has not only transparency, but also an appropriate elastic modulus during packaging, refrigeration, and heating, and even during heating, melt-perforation, large deformation, fusion to containers,
It is required to have heat stability without its own deterioration, etc., and proper adhesion to wraps and containers from low to high temperatures.

[0003] The types of household wrap films currently on the market include stretch films mainly composed of polyvinylidene chloride resin, which is the most convenient, and polyethylene resins and plasticized polyvinyl chloride, which are significantly inferior in wrap suitability. Extrusion cast molding and film formation, which are mainly composed of a base resin, poly-4-methylpentene-1 base resin, and the like. However, it has never been better than a wrap film made of an aliphatic polyester resin, which is considered to be more safe in all aspects, and which is easy to use, is more environmentally and hygienic, and is made of vinylidene chloride resin. .

For example, a stretched film made of a polylactic acid-based aliphatic polyester resin for other uses is disclosed in JP-A-6-2383.
Although disclosed in Japanese Patent Publication No. 6 and the like, the tensile elastic modulus of the film described in the publication exceeds 220 kg / mm ² , and the value is too high, which involves a problem in wrap film applications.
There is no adhesiveness between the wraps and no suitability for the wrap, and it is completely unsuitable as a home wrap film.

Japanese Patent Application Laid-Open No. Hei 9-272794 discloses a method for simply imparting flexibility to a film for use in a conventional polyethylene bag for general packaging, which is different from a wrap use.
A large amount of a polylactic acid-based resin containing a soft aliphatic polyester resin having a low softening point and a crystallization point of room temperature or less (25 to
(80% by weight) to control and suppress the crystal by the flexibility and the interaction between the molecules of both resins to impart transparency. However, this is also an area different from the specific wrap application of the present invention. Also, Japanese Patent Application Laid-Open No. Hei 7-2576
No. 60 discloses that the water vapor permeability used for transporting and storing vegetables, flowers, fruits and the like using polylactic acid resin is 5%.
There is a disclosure of a film having a thickness of 10 to 500 μm for use in maintaining freshness in the field of a conventional biaxially stretched polystyrene film of 0 to 300 g / m ² · 24 hr (packaging with an OPS film). These are in areas different from the use of the present invention and are difficult to use with particular wraps of the present invention.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a conventional wrap film containing a polyglycolic acid (PGA) -based aliphatic polyester resin as a main component, particularly a variety of containers (including porcelain containing It is an object of the present invention to provide an adhesive heat-resistant wrap film suitable for both wrapping and plastic wrapping or packaging without a container.

[0007]

That is, the present invention provides a polyglycolic acid (PGA) having a crystalline melting point of 120 to 250 ° C.
(A) 10 mainly composed of aliphatic polyester resin
A stretched film comprising a resin composition (C) containing 1 to 20 parts by weight of a liquid additive (B) with respect to 0 parts by weight, having a tensile modulus of 20 to 150 kg / mm ² and a temperature of 100 ° C.
, The heat shrinkage ratio X% and the heat shrinkage stress Yg / mm ² are within the range of the relational expressions of the following formulas (1) to (3), the heat resistance is 120 ° C. or more, and the adhesion is 5 to 30 g · cm / 25c
m ^2, which is an adhesive heat-resistant wrap film. Formula (1) Y ≦ (1400−20X) / 3 Formula (2) 2 ≦ X ≦ 45 Formula (3) 5 ≦ Y ≦ 350

In the present invention, the crystal melting point is 120 to 25.
The resin (A) mainly composed of a glycolic acid-based aliphatic polyester at 0 ° C. may be prepared by direct polymerization of a glycolic acid-based aliphatic hydroxycarboxylic acid, or ring-opening polymerization of a cyclic (dimer) body, or an esterified product thereof. Polycondensation or copolymerization with other monomers, or (co) polymerization with its D-form, L-form, or its DL (racemic) -form when the monomer has optical isomers It also includes coalescence. The copolymer includes a random shape, a block shape, and a free mixed structure of both.

In order to maintain the performance of the above-mentioned wrap, the ratio of these resins when copolymerized is slightly different depending on the target components. %, Preferably 1.5 to 20 mol%, more preferably 2 to 17 mol%, and more preferably about 2.5 to 15 mol%. These are convenient for giving flexibility and suppleness to the film, and for giving appropriate compatibility with the additives that give adhesion, and the upper limit is limited due to lack of heat resistance, deterioration of dimensional stability, and the like. You.

[0010] Specifically, other aliphatic hydroxycarboxylic acids to be copolymerized or mixed include, for example, lactic acid, 2-hydroxy-2,2-dialkylacetic acid containing α (or 2) -hydroxyisobutyric acid, At least one selected from β (or 3) -hydroxybutyric acid, β (or 3) -hydroxyvaleric acid, β (or 3) -hydroxyhexanoic acid, 4-hydroxybutanoic acid and other known ones is preferred. However, those in which these cyclic dimers / optical isomers exist (D-form, L-form, DL-form) are also included. These esters may be used as a raw material for copolymerization. Next, β-butyrolactone, β
-Propiolactone, pivalolactone, γ-butyrolactone, δ-valerolactone, β-methylδ-valerolactone, ε-caprolactone, and the like.

Similarly, as the alcohol component at the time of polymerization, that is, aliphatic polyhydric alcohols to be (co) polymerized, ethylene glycol, diethylene glycol, other polyethylene glycols, propylene glycol, 1,3
-Propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-trimethyl -1,6-hexanediol, 1,3-cyclohexanedimethanol, 1,
4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol, tetraethylene glycol, di-, tri-, tetra-propylene glycol, diols having a carbonate bond, etc. And ethylene oxide and propylene oxide can also be used. These may be combined into multiple components.

The acid component at the time of polymerization, that is, aliphatic polycarboxylic acids to be (co) polymerized include malonic acid, succinic acid,
Glutaric acid, adipic acid, pimelic acid, azelaic acid,
Sebacic acid, 2,2-dimethylglutaric acid, suberic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-dicyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, diglycolic acid and ester derivatives thereof, acids It is possible to use an anhydride or the like.
These may be combined into multiple components.

Further, the present invention is not limited thereto. For example, preferred examples of the combination include those obtained by homopolymerization (including a dimer) of glycolic acid as a main raw material, or a small amount of L-lactic acid, D-lactic acid copolymerized or DL-lactic acid copolymerized, 3-hydroxybutyric acid, 3-
2- including hydroxyvaleric acid and α-hydroxyisobutyric acid
Examples include those copolymerized with hydroxy-2,2-dialkylacetic acid, 3-hydroxyhexanoic acid, 4-hydroxybutanoic acid, and ε-caprolactone (including the random, block, and others described above), and esters thereof. May be used as a raw material for polycondensation.

The resin (A) is mainly composed of a glycolic acid-based aliphatic polyester obtained by combining at least one of the above-mentioned monomers with a glycolic acid-based monomer, if necessary. These are mainly composed of those having a crystal melting point (measured according to the DSC method here) of 120 to 250 ° C. If the crystalline melting point of the resin as a raw material is less than 120 ° C., the heat resistance and rigidity of the wrap film are insufficient, and if the crystalline melting point exceeds 250 ° C., the decomposition temperature of the resin becomes close, and the extrudability, stretchability, heat treatment, etc. This is not preferable because the processability such as heat setting property of the resin becomes poor. More preferably, these ranges have a lower limit of 130 ° C. and an upper limit of 240 ° C., and more preferably a lower limit of 140 ° C. and an upper limit of 230 ° C. for the same reason. Also, the crystal structure can be freely controlled by the catalyst,
As long as the crystal melting point falls within the above-mentioned range, various structures and block-like crystal structures are also included.

Further, the range of the saturated crystallinity of the aliphatic polyester as a raw material is usually about 15 to 80%, preferably 20 to 70%. The range of the crystallinity of the film is usually about 15 to 70%, preferably 20 to 60%, and the lower limits thereof are limited by the heat resistance of the film, and the upper limits are insufficient in formability of the raw material and flexibility. Insufficiency (in addition to lack of flexibility by itself, it is difficult to uniformly include a plasticizer, and it is difficult to provide effective adhesion), and transparency of the film is limited. However, after processing into a film due to the influence of processing conditions (quenching etc.) and additives (crystal control) due to the characteristics of the raw material, the degree of crystallinity becomes lower than that described above. ) When the crystallization speed is fast and crystallization occurs quickly, resulting in effective heat resistance (even if the film is localized, but does not melt or perforate), the lower limit of the crystallinity of the film before use is the lower limit Not. In this case, among the aliphatic polyesters described above, waste treatment of a resin having a biodegradable function but having a high degree of crystallization (when composted together with garbage at the time of disposal treatment) is difficult to biodegrade. May be preferred to facilitate

The resin (A) may contain 50% by weight or less, preferably 5 to 4%, in addition to the above aliphatic polyester as the main component.
0% by weight, more preferably 7 to 30% by weight, may be used by mixing at least one other known aliphatic polyester or other thermoplastic resin. These resins include aliphatic polyester resins other than the above-mentioned glycolic acids, polyolefin resins, ordinary polyester resins containing aromatic monomers, polyamide resins, ethylene-vinyl alcohol copolymer resins. , Α-
Olefin (ethylene, etc.)-Styrene copolymer resin (containing hydrogenated resin), α-olefin-carbon monoxide copolymer resin (containing hydrogenated resin), ethylene-alicyclic hydrocarbon copolymer resin (containing Hydrogenated resin), styrene and butadiene or isoprene copolymerized resin (containing hydrogenated resin), polycaprolactones, and the like.

More preferred resins to be mixed and used are selected from lactic acid, 3-hydroxybutyric acid, 2-hydroxy-2,2-dialkylacetic acid containing α-hydroxyisobutyric acid, 3-hydroxyhexanoic acid, 4-hydroxybutanoic acid and the like. Polymers and copolymers containing at least 50 mol% or more of at least one monomer unit (or a unit polymerized from an ester thereof), a D-form, an L-form, or glycolic acid thereof. The copolymer may be selected from copolymers containing 75 mol% or less (however, usually, the optical isomer also affects the crystal structure, so that it is converted as another monomer).

The liquid additive (B) used in the present invention comprises:
It is useful mainly for imparting adhesiveness to wrap film, and is also useful for giving flexibility at the time of handling by adjusting the tensile elasticity. In order to control the adhesiveness (the same work) in a suitable range. Necessary and convenient for facilitating compost treatment after disposal. The viscosity of the main component at 50 ° C. (hereinafter, measured by a B-type viscometer) is at least 5 centipoise or more. A liquid having a viscosity at 100 ° C. of 500 centipoise or less, preferably a viscosity at 100 ° C. of 300 centipoise or less, and a main component having a boiling point of 170 ° C. or more can be suitably used. The addition amount is in the range of 1 to 20 parts by weight based on 100 parts by weight of the resin (A), and the preferred range thereof is 1 to 15 parts by weight, more preferably 2 to 10 parts by weight. The reasons are as described below.

These additives include, among others, aliphatic alcohols or alicyclic alcohols, or at least one alcohol selected from these polyhydric alcohols and polycondensates thereof, and the alcohol component and an aliphatic or aromatic Esters with polycarboxylic acids, esters of aliphatic hydroxycarboxylic acids with alcohols and / or fatty acids, modified products of these esters, polyoxyethylene alkyl ethers and / or esters thereof, oligomers of the resin (A), mineral oils And at least one plasticizer selected from the group consisting of liquid paraffin, and a low polymer composed of a saturated hydrocarbon compound. Although not limited to these examples, these include polyglycerols such as glycerin, diglycerin,..., These are used as a raw material of an alcohol component, and aliphatic fatty acids such as lauric acid, palmitic acid, stearic acid, and olein are used as an acid component. Mono, di, tri, etc. with acid, linoleic acid, etc.
., At least one ester selected from polyesters, or esters of sorbitan and the above-mentioned fatty acids, or ethylene glycol, propylene glycol, tetramethylene glycol, and esters of these polycondensates with the above-mentioned fatty acids, or aliphatic hydroxycarboxylic acids Acids such as citric acid, malic acid, tartaric acid, etc., and 10 carbon atoms
The following esters with lower alcohols, or malonic acid as a polycarboxylic acid, succinic acid, glutaric acid, adipic acid, etc. and esters of aliphatic alcohols, or epoxidized soybean oil as a modified product of these esters, Epoxidized linseed oil and others.

Preferably, those having at least two kinds of viscosity differences (measured at 50 ° C., the difference is at least 3 centipoise) selected from these are used by mixing and used. / Low viscosity material "
The mixing ratio is preferably 0.5 / 10 to 9/1. More preferably, the viscosity difference is at least 10, and the weight mixing ratio of "high viscosity material / low viscosity material" is more preferable. Is preferably mixed and used in the range of 1/9 to 5/5. In the case of mixing three or more kinds, it is only necessary that at least 5% by weight of the total addition amount, any two components satisfy the above. The reason for this is that the speed and amount of bleed-out on the film surface are averaged, stabilized over time, and act synergistically when used.

The range of the tensile modulus of this film is 20
１５０150 kg / mm ² , the lower limit is the cutability of the film (having good cutting ability), the stiffness of the film, the extensibility of the film (after pulling and cutting, stretching until packaging, wrinkle resistance) ), Handling, etc.,
The upper limit is also related to the effect of controlling the elongation at break of the film to an appropriate value, and is limited in order to maintain the fit property at the time of packaging and the cut property (with a sharp edge). For the same reason, a preferred range 25~130kg / mm ^2, more preferably 25 to 1
It is 20 kg / mm ² .

The range of the heat shrinkage in the present invention is from 2 to 45.
%, Preferably 3 to 40%, more preferably 3 to 35%
The lower limit is the fit property during heating (shrinks slightly,
Remove the wrinkles of the film that temporarily adhered to the container, the raised contents, and the outer wall of the container, and increase the contact area, or reduce the places where the film is easily peeled off due to the wrinkles on the film, and make the film adhere.)
It is effective for heating, etc., it becomes high temperature when heated, water vapor comes out and peels off,
It is effective to prevent insufficient adhesion, and the upper limit causes problems such as film detachment, tearing, container (when made of plastics), deformation of contents, and the like.

The range of the heat shrinkage stress value in the present invention is 5 to 3
50 g / mm ² , preferably 10 to 300 g / mm ² ,
More preferably, it is 10 to 250 g / mm ² , and the lower limit is the shrinkage rate upon heating, the fit property to the container or the packaged object (the same as the above-mentioned case of the heat shrinkage rate), the strength exhibited by stretching, the cut property, etc. The upper limit is limited by detachment of the film from the container at the time of heating, tearing, deformation of the container and contents, and the like. The range of the adhesiveness (the same work) of the film of the present invention is in the range of 5 to 30 g · cm / cm ² , and the reason is that the lower limit or less is used for packaging and storage (including refrigeration), heating at the container or Film peeling due to insufficient adhesion between the film surfaces occurs, the upper limit is poor drawability from the box and roll, and the films are too close to each other at the time of packaging, and the film spreadability after cutting (the overlapped parts are difficult to peel off and overlap. , Etc.), and the packaging property may be deteriorated. The preferred range is 7 to 25 g.
cm / cm ² .

The heat resistance of the film is at least 120 ° C., preferably at least 130 ° C., more preferably at least 14 ° C.
0 ° C. or higher. The reason for the lower limit is microwave ovens, etc.
The contents shatter due to film shrinkage due to breakage of the packaging during heating, etc.
The upper limit is not particularly limited, but is linked to other characteristics (for example,
However, the temperature is preferably about 270 ° C. because of poor workability and an excessively high tensile modulus. Also, the reason for the above range is that the initial stage of heating in a microwave oven or the like is good if the film is not damaged by steam at about 100 ° C. for the time being. When the mixture contains oil components and salts, the temperature may be particularly high when the content is low. In addition, if the heat resistance is poor, holes may be formed and the film components may melt, dissolving the film components. This is because if the package is heated without a container, the film may be welded, and the package may be unable to be taken out if the package is not taken apart unless it is in close contact with a vacuum state while taking out the package.

The range of the crystallinity of the film in the present invention is as described above. The crystallinity of the film can be freely controlled by the composition conditions, raw material production conditions, stretching conditions, heat treatment conditions, and the like, and can be varied over a wide range from the values measured by the raw materials themselves. The upper limit can be set higher than the raw material if it is appropriately oriented and crystallized, and can be set freely. In addition, about the measuring method of various physical properties shown in an Example etc., it is as follows.

(1) Tensile Modulus The tensile modulus is measured in accordance with ASTM-D882, and is determined with respect to the flow direction during biaxial stretching of the film.
The stress value at the time of 2% elongation in the vertical and horizontal directions was converted into 100%, and expressed as an average value of the thickness-converted values.
g / square (sq) millimeter (mm ² ) unit]. (2) Heat shrinkage rate Heat shrinkage rate is 10 minutes in a state in which powder such as talc is sprinkled so as not to adhere a film sample of 100 mm square, placed horizontally in an air oven type constant temperature bath set at a predetermined temperature, and freely shrunk. After processing, the shrinkage of the film is determined, expressed as a percentage of the value divided by the original dimension, and similarly expressed as the average value (% unit) in the vertical and horizontal directions.

(3) Heat shrinkage stress value The heat shrinkage stress value is obtained by sampling a film in a strip shape having a width of 10 mm, loosening it to a strain gauge-equipped chuck with a chuck interval of 50 mm by 5% (longer) than a predetermined length. The maximum value within 20 seconds after immersion obtained by immersing it in silicone oil heated to a predetermined temperature and detecting the generated stress. Similarly, the average value of the same value in the vertical and horizontal directions In terms of thickness (g / mm 2).

(4) Adhesion (same work) Adhesion (same work) was measured at a constant temperature of 23 ° C. and a relative humidity of 65% in each of two ends of two cylinders having a circular area of 25 cm 2. The film is tensioned and fixed so as not to cause wrinkles, two cylinders are aligned so that the film surfaces overlap each other, and pressed for 1 minute under a load of 500 g. Expressed in terms of work (g · cm / 25 cm ² ) when peeled off at a speed of 100 mm / min in the vertical direction. (5) Heat resistance Heat resistance is determined by contacting a central portion of a film stretched on a 100 mm square frame in a tension state with a hot plate having a radius of 40 mm, whose temperature can be adjusted, for 1 minute, and having a total area of at least 10 mm ² on the film surface. Is measured at a pitch of 5 ° C., and is expressed as the temperature one step before (the number of sample repetitions, average of N = 5).

(6) Crystallinity The crystallinity was determined by wide-angle X-ray diffraction using a raw material resin, which was sufficiently annealed at the optimum temperature for crystallization, and was equilibrated. The correlation between the melting energy and the melting energy is determined, and the DSC method (JIS-
A calibration curve is determined in advance according to K7122), and the target sample is measured. However, when measuring the film of the product, the film (as it is) contained in the resin (A)
Conversion only for components (layers) (mixed with other resins, multilayer)
And measure.

The resin composition (C) of the present invention contains 1 to 20 parts by weight of the liquid additive (B) per 100 parts by weight of the aliphatic polyester resin (A). 15 parts by weight, more preferably 2 to 10 parts by weight. When (B) is less than the above lower limit, the tensile elasticity of the wrap film is adjusted and used (slipperiness, pull-out property from a roll, static electricity generation control, self-adhesive area, sharpness, etc.). Performance, adhesion work (adhesion)
And the like cannot be controlled in a suitable range, which is not preferable, and the stretching stability is often poor. When the content of (B) is more than the above upper limit, not only the resin (A) is excessively plasticized but the heat resistance becomes insufficient, but also the film tensile modulus (affects the film waist and handleability) decreases, (Extensible) stretch after cutting in, the overlapping part which inhibits the packaging property increases, and the wrinkles accompanying them become difficult to peel off and stretch, making it difficult to pack in a stretched state. Heating causes the film to shrink too much, making it easy for the film to come off from the container, causing uneven heating and resulting in fouling of the inside of the refrigerator. It bleeds out to the surface of the film or to the end of the roll, undesirably stains the box, sticks the wrap film, shifts to food, or causes the amount of close contact work to fall out of a preferred range.

The resin composition (C) is extruded, stretched and formed into a film, and appropriately heat-set.
The dimensional stability and finally the degree of crystallinity are controlled to impart heat resistance, and the adhesive heat-resistant wrap film of the present invention is obtained. The film is formed by extrusion from a T-die, quenching by a cast roll, stretching by a roll stretching machine or a tenter, or extrusion from a circular die into a single layer or, if necessary, into a multilayer, a water-cooled ring. There is a method of rapidly cooling to a predetermined temperature, heating to a predetermined temperature in the next step, blowing air, performing tubular stretching, and then heat setting, etc., but the manufacturing process is inexpensive and productivity is low. The latter method is preferred because the thickness of the obtained film in the width direction, uneven thickness dispersion, etc. are easily controlled, and the product yield is good.

The relationship between the heat shrinkage factor X at 100 ° C. and the heat shrinkage stress Y suitable for the adhesive heat-resistant wrap film of the present invention is expressed by the above-described formulas (1) and (2) in an XY coordinate system.
This is within the range of the figure surrounded by the line of the formula (3) because the heat shrinkage X exceeds 45% or the heat shrinkage stress Y exceeds 350 g / mm ² (for example, in a microwave oven). )) The wrap film placed on the plate shrinks when heated and comes off the container, breaks, or the container or packaged object (food)
Is undesirably deformed. Note that a relational expression in a preferable range is a range surrounded by the following expressions (4), (5), and (6). Formula (4) Y ≦ (1100-20X) / 3 Formula (5) 3 ≦ X ≦ 40 Formula (6) 10 ≦ Y ≦ 300

The preferred range of the heat shrinkage ratio here is 3
-40%, a more preferred range is 3-35.
%. The preferred range of the heat shrinkage stress is 1
Within the 0~300g · cm / 25cm ^2, and more preferred range is in the range of 10~250g · cm / 25cm ^2. In addition, the reason expressed by the above-mentioned temperature is that, when a heating target containing water is put into a heat-resistant container mainly in a microwave oven or the like or cooked or simply heat-treated, initially, most of the water is exposed to water vapor at about 100 ° C. This is because it is heated.

The preferred various packaging suitability in the present invention is mainly expressed by the above-mentioned properties and their ranges, but other sensory packaging properties are also practically important, and are described as the preferred ranges in the above and Examples. . The thickness of the adhesive heat-resistant wrap film of the present invention is 5 to 15 μm in terms of ease of handling as a household wrap film and raw material cost.
Is preferably 6 to 13 μm, and more preferably 7 to 11 μm. Further, the adhesive heat-resistant wrap film of the present invention may have a multilayer structure composed of at least two layers of the same kind made of the resin composition (C) different from each other, if necessary.

Further, the adhesive wrap film of the present invention comprises:
If necessary, at least one layer of the resin composition (C)
A total thickness ratio of 10 to 95%, preferably 5
0 to 90% and at least one other resin layer of the remaining thickness (subtracted from 100%) ratio as another layer, that is, another aliphatic polyester resin, a polyethylene resin, a polypropylene resin, Polyolefin resin (PO) including polybutene-1 resin, poly4-methylpentene-1 resin, and polyethylene terephthalate (including modified) resin; polybutylene terephthalate (including modified) resin; Resin (PEST) partially containing an aromatic component, ethylene-vinyl alcohol copolymer resin (EVOH), α-
Olefin-carbon monoxide copolymer resin (including hydrogenated resin),
at least one selected from α-olefin (ethylene) -styrene copolymer resin (contained hydrogenated resin), ethylene-cyclic hydrocarbon-based compound copolymer resin (contained hydrogenated resin), polyamide resin, caprolactone resin, etc. May have a multilayer structure composed of at least one layer of a resin, and may be further irradiated with an arbitrary layer by a known method such as a high energy beam such as an electron beam, and may be crosslinked to have heat resistance. .

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited thereto. The following was used as the glycolic acid-based aliphatic polyester resin used in this example and the like. A-1: a polyglycolic acid-based resin obtained by copolymerizing L-lactic acid with 5 mol% (crystal melting point: 218 ° C., crystallinity: 45)
A-2; Resin obtained by copolymerizing glycolic acid with 10 mol% of L-lactic acid (crystal melting point: 203 ° C., crystallinity: 37%) A-3: Copolymerizing glycolic acid with 3-hydroxyvaleric acid by 7 mol% Resin (crystal melting point 204 ° C, crystallinity 42
A-4; α-hydroxyisobutyric acid in glycolic acid is 10%.
Mol% copolymerized resin (crystallinity 40%, crystal melting point 21
A-5: Resin obtained by copolymerizing glycolic acid with caprolactone at 5 mol% (crystallinity: 43%, crystal melting point: 210 ° C.) A-6: The above A-2: 70% by weight and α-hydroxyiso Resin obtained by copolymerizing 5 mol% of L-lactic acid with butyric acid (crystal melting point: 160 ° C., crystallinity: 50%), 30% by weight of mixed composition A-7; DL (racemic) -lactic acid in glycolic acid: 8 Mol% copolymerized resin (crystal melting point 187 ° C, crystallinity 40
%)

The liquid additive (B) used here is in the above-mentioned preferred range (viscosity), and is as follows. B-1: tetraglycerin monolaurate (1700 /
150, hereinafter the unit of viscosity, centipoise is abbreviated, and the measurement temperature is described in the order of 50 ° C./100° C.) B-2: diglycerin monolaurate (200/25) B-3; polyoxyethylene alkyl ether (18 /
2) B-4; Eposhated soybean oil (110/16) B-5; Mineral oil (13/3) B-6; Polyoxyethylene sorbitan laurate (2
10/34) B-7; hexaglycerin (1000/70) B-8; acetyltributyl citrate (11/2)

The resin composition (C) used here is as follows. C-1; polyglycolic acid (A-8: crystal melting point: 225)
80% by weight of a resin obtained by copolymerizing 5 mol% of glycolic acid with L-lactic acid (crystal melting point: 162 ° C., crystallinity: 38%); 4 parts by weight of B-2, 2 parts by weight of B-5, 1 part of B-1
80 parts by weight of a composition C-2; A-7 mixed with 20 parts by weight of an ethylene-vinyl alcohol copolymer resin (39 mole% copolymerization of ethylene).
3 parts by weight of B-1 to 100 parts by weight of
Further, a composition C-3 in which 3 parts by weight of B-5 was mixed, a hydrogenated copolymer of ethylene (partially propylene) -carbon monoxide copolymer resin (crystal melting point: 220 ° C.) at 85% by weight of A-7. To 100 parts by weight with the addition of 15% by weight,
A composition in which 3 parts by weight of B-3 and 2 parts by weight of B-4 are mixed. C-4; 80% by weight of A-6, polybutylene terephthalate copolymer resin (PEST-1: 1 as an alcohol component) 80 mol% of butanediol, 19 mol% of triethylene glycol, and 1 mol% of polytetramethylene glycol: a copolymer having a crystal melting point of 220 ° C. and a degree of crystallinity of 40%) and 100 wt. , B
A composition obtained by mixing 3 parts by weight of -6 and 2 parts by weight of B-7

A reference checkpoint in the present invention relating to packaging property and the like is to preferably satisfy the following items including sensual performance, which is difficult to quantify. Aging preservability of small rolls When a product placed in a box of 30 cm width and 50 m roll is stored for 30 days at 30 ° C. and a relative humidity of 65%, the additive oozes out from the end of the roll, and the film is appropriately peeled. No problem in tackiness of film surface. Elongation of the film edge, static electricity is not severely generated, stick is not applied to the hand / box, etc., the film is easy to spread and easy to grasp by hand, and the draw-out resistance is moderate. . Cutability The film must be stretched and stretched comfortably (with a light sound) without any wrinkling while being stretched, and can be cut accurately without permanent deformation. Film extensibility The film can be wrapped well without being wrinkled or overlapped after cutting.

Without being particular about the adhesiveness, the type of container (both porcelain and synthetic resin), or even without a container, the overlapped portions between the film containers, between the film objects to be packaged, and between the films do not bulge, Adhering, and it should not come off during storage at low temperatures or heating. Heat resistance The film does not tear, melt, or puncture during heating, and the film does not stretch due to internal pressure. During storage and heating, taste and hygiene, no smell in food, no additives are transferred, and no film fragments are mixed. After heating, the film must be easily removable, and the films must be welded to each other so that they cannot be peeled off, and may not be stained by being welded to the contents or to a container (particularly made of synthetic resin). There should be few problems in disposal after use.

[0041]

Examples 1 and 2 and Comparative Examples 1 and 2 As shown in Table 1, a polyglycolic acid resin (A-1) was used as an aliphatic polyester (A) in an extruder having a screw diameter of 50 mm, and The extruder having an injection port in a cylinder portion corresponding to a portion having a kneading portion in the middle of the length direction of the screw is heated and kneaded and melted, and is added as a liquid additive (B) to 100 parts by weight of the resin as described above. B-1 of the kind
Inject a predetermined amount of / B-6 at a mixing ratio of 1/1, mix well, extrude from an annular die having a diameter of 100 mmφ and a slit of 1.0 mm, and inject liquid paraffin inside the tube, The outside is quenched and solidified by coolant water,
It was taken off by a nip roll, and a uniform tubular raw material having a folding width of 140 mm was prepared. Subsequently, these raw materials are freely annealed in a uniform state, passed between two pairs of differential nip rolls, heated through a heating zone under an atmosphere of 70 ° C., and heated in a stretching zone under a hot air atmosphere of 65 ° C. Air is injected into the inside with an air-filling nip roll installed at the outlet in the flow direction to continuously form inflatable bubbles. At the end of the stretching of the cooling zone, 17 ° C. cold air is blown to finish the stretching. The nip roll at the outlet is closed, and the sheet is simultaneously biaxially stretched to about 5.5 times in length and 4.7 times in width, and then continuously passed through a heat-set zone in which the temperature is controlled respectively.
Next, the ears were cut off with a winder, and 2
It was wound on a piece of film. Table 4 shows the measurement results of the obtained film.

[0042]

[Table 1]

The stretching stability of the films of Examples 1 and 2 was as follows:
In the case of Comparative Examples 1 and 2, the bubble was more swaying and unstable, but stable. Next, these films were rolled into a small roll of approximately 50 m wound around a 30 cm wide paper tube, placed in a box of a commercial household wrap (made of vinylidene chloride resin from Asahi Kasei Kogyo Co., Ltd.), and subjected to a packaging test. Carried out.

The packaging test was carried out by placing rice in a commercially available porcelain (or plastics) container for heating a microwave oven, placing a curry thereon, and changing the heating time in the microwave oven in various ways, with the sample repetition number being n = 5. did. First, wrapping was performed in each of the boxes containing the films. As a result, it was found that the films of Examples 1 and 2 were made of the above-mentioned commercially available vinylidene chloride-based resin (hereinafter, referred to as “films”).
As in the case of commercially available PVDC), a predetermined amount could be accurately drawn out with an appropriate resistance. However, the film of Comparative Example 1 (hereinafter referred to as ratio 1) sticks out of the box or generates static electricity and sticks around. It was not desirable. The film of Comparative Example 2 (hereinafter also referred to as ratio 2) was clearly too sticky, and stuck to a part of the box, stuck to the hand, or was defective. Next, with respect to the cutting properties of the blade attached to the box, the films of Examples 1 and 2 were cut comfortably and the cutting properties were good as in the case of commercially available PVDC. Ratio 1 is because the film's elastic modulus is too high, and there is almost no adhesion, so it is difficult to fix the film to the holding part of the box at the time of cutting, the roll is blocked and it is difficult to pull out, or it is locally displaced. And it was difficult to cut into the cutting edge, and the cut surface was detached from the cutting edge and was torn diagonally. In addition, the packaging properties are poor (films stick together due to static electricity, or stick to arbitrary places, but there is no adhesion to the important container or film, and the film spreads and the packaging spreads. Can not be fixed) was not usable, ratio 2
Although the cut property was too soft and slightly unsatisfactory as compared with the examples, the film was sticky and the stretchability of the film immediately after cutting was poor, and the overlap property was poor.

Next, at the time of heating in a microwave oven, the ratio 1 indicates that since the film does not adhere as described above, water vapor easily leaks, local heating easily occurs, and the contents easily spill outside.
The taste of the food has become worse. In the ratio 2, the film has high shrinkage, the adhesive portion is displaced, the film and the container are easily peeled off, and the contact portion with the contents (curry) is broken when the heating time is slightly longer, and plastics (PP; polypropylene) In the case of a container made of), it was observed that the container was partially welded, and the container was stained after the film was peeled off. None of these defective phenomena of Examples 1 and 2 were at all possible, and the packaging and heating could be performed well, the film could be easily peeled off later, and the taste of the cooked product was good. Characteristics.

[0046]

Examples 3 to 6 As shown in Table 2, various aliphatic polyester resins (A) and their respective liquid additives (B) were used in the order of Examples 3, 4, 5 and 6 in the mixing ratio. When expressed, 1/3 of B-1 / B-3, 2 of B-2 / B-5
/ 3, 3/1 of B-3 / B-7 and 1/1 of B-4 / B-5, and a predetermined amount shown in Table 2 was added to 100 parts by weight of the resin. The stretching temperature and the stretching ratio were each adjusted in the same manner as in Example 1 and processed in the same manner to obtain a stretched film having the characteristics shown in Table 2 and having a thickness of 8.7 μm. The stretchability was good, and there was no major problem.

[0047]

[Table 2] These films were subjected to a packaging test in the same manner as in Example 1. As a result, the drawability, cutability, stretchability, overlap, adhesion, heatability, etc. were sequentially tested. Was not found and was within the preferred range of the present invention as in Examples 1 and 2.

[0048]

Examples 7 and 8, Comparative Examples 3 and 4 As shown in Table 3,
Various aliphatic polyesters (A) and liquid additives (B) were selected. In Example 7, B-4 was added to 4 parts by weight, and B-7 was added to 100 parts by weight of resin. 2
In Example 8, B-2 was added to 3 parts by weight and B-5 was added to 1 part by weight. In Comparative Example 3, 73 mol% of glycolic acid was used as the aliphatic polyester.
And a crystalline melting point of L-lactic acid of 27 mol% and a melting point of 118 ° C.
A resin (D-1) having a crystallinity of 11% was used, and then stretched in the same manner as in Example 1 by selecting stretching conditions and treating in the same manner. The temperature conditions were set lower and the heat treatment temperature was adjusted lower. In the case of Comparative Example 4, the stretching ratio conditions were increased, and the heat treatment conditions were controlled for the raw material and the film to obtain films having an average thickness of about 9.0 μm having the characteristics shown in Table 3 below.

[0049]

[Table 3]

These films were evaluated in the same manner as in Example 1. As a result, Examples 7 and 8 could be used without any problem, and both were within the preferable range of the present invention. The film of Comparative Example 3 was inferior in pulling out the film from the roll of the box, and was too soft to be easily grasped, and was not crisp. In a similar heating test in a microwave oven, the film was abnormally expanded at the initial stage of water vapor generation, then contracted, and the adhered portion was easily detached or punctured. In the latter stage of the heating, the contact portion with the curry was melted and a hole was formed, and a phenomenon was observed. In addition, there was a tendency that the container was partially melted and fused to stain the container. The film of Comparative Example 4 was too crisp because the tensile elasticity of the film was too high, and it was easy to tear in a direction different from the blade edge when cutting, and the film overlapped part returned when the film was in close contact, and it was easy to loosen. Also during heating, the shrinkage stress of the film was high, so that the film was easily loosened locally on the outer wall of the container. When it did not come loose, it sometimes broke from the contact portion with the contents. In the case of a plastics (PP) container, the container was sometimes deformed.

[0051]

Examples 9 to 12 As shown in Table (4), the polyglycolic acid-based aliphatic polyester (A) of the present invention was
Add a predetermined amount of another thermoplastic resin, and further add the additive (B)
A resin composition (C) was prepared by mixing a predetermined amount of
And a film having an average thickness of about 8.6 μm was obtained.

[0052]

[Table 4] These films were evaluated in the same manner as in Example 1. In any case, there was no major problem and the packaging and heat treatment could be performed well, and the performance was within a preferable range.

[0053]

Example 13 The above-mentioned A-1 was used as the aliphatic polyester (A), the above-mentioned PEST-1 was used as the other resin, and 5 parts by weight of B-6 and 1 part by weight of B-1 were used as the additive (B). Were separately mixed with each other in the same two extruders in the same manner as described above, and two or three layers (A-1) were formed from a multilayer annular die.
/ PEST-1 / A-1: Layer composition ratio is 35/30/35
%) And about 8.5 μm as in Example 1.
m of the stretched film. The characteristics are expressed in the order of “tensile elastic modulus / heat shrinkage rate / stress / heat resistance / working adhesion / film crystallinity”, and “65/11/145/20”.
5/14/33 (each unit is abbreviated). " Each packaging test did not have any serious problems and was within the preferable range of the present invention.

[0054]

Example 14 Next, the intermediate layer was made into an ethylene-vinyl acetate copolymer resin (melt index: 0.8, density: 0.928) to which the additive (B) was not added, and an electron beam (energy: The same process as in Example (13) was carried out except that the treatment was carried out at a dose of 6 Mrad at 500 KV) to obtain a stretched film of about 9 μm. Its characteristics are similar to those described above in the order of “45/19/150/200/15”.
/ 32 (each unit is abbreviated). " Each of the packaging tests was also within the preferred range, and no major problems were observed, which was within the preferred range of the present invention.

[0055]

According to the present invention, various required characteristics at the time of packaging (for example, pull-out property, cut-off property, stretch-handling property, close-fixing property, heat resistance, type of container, case without container, etc.) And a film for house hold wrap, which can easily be disposed of.

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[Procedure amendment]

[Submission date] July 22, 1998 (1998.7.2
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

The resin (A) is mainly composed of a glycolic acid-based aliphatic polyester obtained by combining at least one of the above-mentioned monomers with a glycolic acid-based monomer, if necessary. These have a crystal melting point (here, measured at a scan speed of 10 ° C./min according to the DSC method) of 120 to 25.
The main component is 0 ° C. If the crystalline melting point of the resin as a raw material is less than 120 ° C., the heat resistance and rigidity of the wrap film are insufficient, and if the crystalline melting point exceeds 250 ° C., the decomposition temperature of the resin becomes close, and the extrudability, stretchability, heat treatment, etc. This is not preferable because the processability such as heat setting property of the resin becomes poor. These more preferred ranges are for the same reason, with a lower limit of 1
30 ° C., the upper limit is 240 ° C., more preferably the lower limit is 140 ° C., and the upper limit is 230 ° C. The crystal structure is
As long as it can be freely controlled by a catalyst and the crystal melting point falls within the above range, various structures and those having a block-like crystal structure are also included.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08K 5/10 C08K 5/10 C08L 67/04 C08L 67/04 F term (reference) 3E086 AD13 BA04 BA15 BA33 BB22 BB41 BB58 BB75 BB90 CA01 4F071 AA14 AA15X AA21X AA29X AA44 AA45 AA54 AA83 AA84 AA88 AA89 AC02 AC10 AE04 AE17 AF19Y AF20Y AF45Y AF61Y AH04 BA01 BB06 BB08 BC01 BC10 BC12 4F100 AH01A AH01H AH02A AH02H AK01A AK03B AK04B AK04J AK08B AK08J AK41A AK41B AK42B AK46B AK48B AK69B AL01B BA01 BA02 BA03 BA04 BA05 CA04A CA23A EH17 EJ37A EJ38 GB15 JA03A JA04A JA06A JA06H JA11A JA20A JA20B JA20H JB16A JJ03A JK06A JK07A JL00 YY00A 4J002 AE054 BB033 BB103 BB123 BB173 CF03 CF03 CF043

Claims (10)

[Claims] 1. A liquid additive (B) 1 to 100 parts by weight of a resin (A) mainly composed of a glycolic acid (PGA) based aliphatic polyester resin having a crystal melting point of 120 to 250 ° C.
A stretched film composed of the resin composition (C) containing 20 parts by weight, having a tensile modulus of 20 to 150 kg / mm.
^{In 2} , the heat shrinkage rate X% at 100 ° C. and the heat shrinkage stress Yg / mm ² are within the range of the relational expressions of the following formulas (1) to (3), the heat resistance is 120 ° C. or higher, and the adhesion is 5-30
g · cm / 25 cm ^2, which is an adhesive heat-resistant wrap film. Formula (1) Y ≦ (1400−20X) / 3 Formula (2) 2 ≦ X ≦ 45 Formula (3) 5 ≦ Y ≦ 350 2. The adhesive heat-resistant wrap film according to claim 1, wherein the glycolic acid-based aliphatic polyester resin is a polymer containing at least 75 mol% of a unit composed of polyglycolic acid. 3. A glycolic acid-based aliphatic polyester resin comprising glycolic acid as a monomer as a base material, a lactic acid isomer, a lactic acid DL form (racemic form), 3-hydroxybutyric acid, -Hydroxyvaleric acid, ε-caprolactone, 2-hydroxy- including α-hydroxyisobutyric acid
2,2-dialkylacetic acid, 4-hydroxybutanoic acid, 3
The adhesive heat-resistant wrap film according to claim 1, comprising a copolymer containing at least 1.5 to 25 mol% of at least one monomer unit selected from -hydroxyhexanoic acid. 4. The glycolic acid-based aliphatic polyester resin contains at least 75 mol% of a unit composed of glycolic acid.
A polymer containing at least 50% by weight of a polymer containing at least 85 mol% of a unit composed of lactic acid, a polymer containing at least 85 mol% of a unit composed of 3-hydroxybutyric acid,
2-hydroxy-2,2 containing α-hydroxyisobutyric acid
At least 85 mol% of units comprising dialkyl acetic acid
The adhesive heat-resistant wrap film according to claim 1, comprising 50% by weight or less of at least one kind of aliphatic polyester-based polymer selected from the group consisting of polymers. 5. The liquid additive (B) is a liquid whose main component is a liquid having a viscosity at 50 ° C. of 5 centipoise or more and a viscosity at 100 ° C. of 500 centipoise or less, and having a boiling point of the main component. The adhesive heat-resistant wrap film according to claim 1, wherein the temperature is 170 ° C or higher. 6. The liquid additive (B) comprises at least one alcohol component selected from aliphatic alcohols, alicyclic alcohols, polyhydric alcohols thereof and polycondensates thereof, and aliphatic fatty acids, Esters with at least one fatty acid selected from aliphatic polycarboxylic acids,
Esters of aliphatic hydroxycarboxylic acids with alcohols and / or fatty acids, and modified products of these esters, polyoxyethylene alkyl ethers and esters thereof,
Oligomers of aliphatic polyesters, mineral oil, liquid paraffin, low-polymers composed of saturated hydrocarbon compounds,
6. The adhesive heat-resistant wrap film according to claim 1, comprising at least one plasticizer selected from the group consisting of: 7. The adhesive heat-resistant wrap film according to claim 1, wherein the polyglycolic acid-based aliphatic polyester has a crystallinity of 15 to 80%. 8. The film comprises 50 to 99% by weight of an aliphatic polyester-based resin composition (C), and further contains 1 to 50% by weight of a thermoplastic resin other than the aliphatic polyester-based resin. The adhesive heat-resistant wrap film according to claim 1. 9. The adhesive heat-resistant wrap film according to claim 1, wherein the film is composed of at least two layers composed of different aliphatic polyester resin compositions (C). 10. The film has a total thickness ratio of 10% to 90% of at least one layer composed of the aliphatic polyester resin composition (C), and a total thickness ratio of 90% to 10%.
% Of at least one layer of another aliphatic polyester resin,
Caprolactone-based resin (R), polyolefin-based resin (PO), and polyester-based resin (PEST) containing an aromatic derivative, ethylene-vinyl alcohol-based copolymer resin (EVOH), polyamide-based resin (PA), ethylene ( Or at least one other α-olefin) -carbon monoxide copolymer (containing hydrogenated resin) resin, ethylene (or at least one other α-olefin) -cyclic hydrocarbon copolymer The adhesive heat-resistant wrap film according to claim 1, comprising a layer made of at least one resin selected from the group consisting of (contained ring hydrogenated resin) resin.