JPH0911426A - Laminated polyester-based wrapping film - Google Patents

Abstract

PURPOSE: To hold self-bonding properties and heat resistance and equipped with small barrier properties by a method wherein the wrapping film constituting three layers or more consisting of a core material and both surface layers made of a specified copolymer polyester and a compound represented by the formulae. CONSTITUTION: By constituting three layers or more consisting of a core material and both surface layers, the whole film has the tensile modulus of elasticity of 3,000-10,000kg/cm<2> . Both the surface layers consist of a dicarboxylic acid component mainly made of terephthalic acid and a diol component containing 1,4-butanediol and one or more kind of diol represented by formula I (in which (n) is the integers from 2 to 4 when (m) is equal to 1 and (n) is the real number from 6 to 65 and the diol component is made of 100 pts.wt. copolymer polyester, which contains 55-85mol% 1,4-butanediol in 100mol% of total diol component except the diol having (m) equal to 2 and 10-45mol% the diol having (m) equal to 1 under the condition that the diol having (m) equal to 2 is below 0.2mol% and has the reduced viscosity of 0.8-1.6dl/g and the melting point of 160-210 deg.C and 1.5-10 pts.wt. of a compound represented by formula II, in which R is a saturated alkali residue I is an integer from 0 to 3, to total acid component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chlorine-free laminated polyester wrap film used for packaging foods and the like by utilizing the self-adhesiveness of the film in general households, restaurants and the like.

[0002]

2. Description of the Related Art A film having at least three layers consisting of a core layer and both surface layers, and having a total tensile elastic modulus of 3000 to 10
A chlorine-free laminated wrap film of 000 kg / cm ² is known (for example, JP-A-4-249150, JP-A-6-238848, and JP-A-6-262738).
No.). This kind of wrap film is stored in a storage box in a state that it is wound on a paper tube, cut the necessary amount of film with a cutting tool attached to the storage box, and wrap it directly around food or wrap it, or It is generally used to package food on a plate or the like together with the plate.

In the layer structure of the laminated film of the above publication, the core layer is composed of an aliphatic polyamide resin (JP-A-4-249150) and a polycarbonate resin (JP-A-6-238848).
JP-A-6-26).
No. 2738), the surface layers of which are all made of polypropylene resin. The role of the surface layer in this case is to impart self-adhesiveness that allows the films to be sealed with each other during packaging, to impart heat resistance capable of being heated in a microwave oven while packaging the food, and because the food does not dry. And to provide the water vapor barrier property thereof. In addition, the role of the core layer is to give a suitable firmness and elasticity to make the wrap film easy to use, to give an odor barrier property to prevent the odor of food from leaking, and to heat the microwave while the food is packaged. It is to impart possible heat resistance. The role of the film as a whole is to provide high usability, and the film can be pulled out from the box without clinging to it, and the overall thickness is 5 to 20 μm in order to improve the conformability of the film to the package. The total tensile elastic modulus is set to 3000 to 10000 kg / cm ² by selecting the above and adjusting the composition ratio of the core layer and the surface layer.

Further, in order to further impart the adhesion between the films, an appropriate amount of additives is added to the film. For example, in the laminated film disclosed in the above publication, polybutene and monoglyceride are added to the surface layer (Japanese Patent Laid-Open No. Hei 4-
249150), addition of glyceride and fatty acid ester (JP-A-6-238848 and JP-A-6-26).
2738).

On the other hand, a plastic wrap made of polyvinylidene chloride (PVDC) is widely used at present in the market. This PVDC wrap is marketed under the brand names of Saran wrap and Cle wrap.
The share of DC laps has reached about 80% of the lap market. The reason why PVDC wrap is widely accepted is that it has better self-adhesion than other wraps made of polyethylene (polyethylene, polyvinyl chloride, etc.), heat resistance, prevention of food drying, and odor scattering. This is because the water vapor barrier property and the odor barrier property for prevention are also excellent.
Due to these excellent performances, it has become widespread, and the term “wrap” refers to PVDC wrap. In addition, from the feel of the wrap when using it, its excellent performance is imaged, leading to a sense of security when using it. In other words, the feel of the user is one of the important quality requirements of the wrap film in the market.

Therefore, even if a non-chlorine wrap intended to replace PVDC wrap has good performance, it is unacceptable in the market if the feel is different from that of PVDC wrap. Recently, the wrap marketed as a chlorine-free laminated wrap is polyolefin resin 3
It is a layer of view wrap (trade name). The layer structure of this polyolefin three-layer wrap is a core layer made of a polypropylene resin, both surface layers made of a polyethylene resin, and a fatty acid ester added to the film to enhance adhesion. The layer constitution ratio is surface layer / core. Layer / Surface layer = 15/70 /
The total thickness is about 10 μm and the tensile modulus of elasticity is about 3500 kg / cm ² . This polyolefin three-layer wrap has a polypropylene resin in the core layer and has a tensile elastic modulus adjusted to about 3500 kg / cm ² as compared with the three laminated wraps of the above-mentioned publication, so that the shape of the film into the package is It has excellent follow-up characteristics and, along with it, excellent self-adhesion. On the other hand, the odor barrier performance is inferior due to the type of resin used.

[0007]

However, even with such a carefully selected and marketed polyolefin three-layer wrap,
Although it has better heat resistance than PVDC wrap,
The self-adhesion is not sufficient, and the films cannot be properly sealed with each other. In addition, the texture when used is PVDC
Unlike wrap, it has a "wax" -like feel that is unique to polyolefin resins, and this unique feel cannot be wiped away. Due to this lack of self-adhesion and the difference in feel,
Market share of commercial polyolefin 3-layer wrap is 5%
Has not yet reached. That is, there is no non-chlorine wrap having the same feel as PVDC wrap and the same self-adhesiveness.

On the other hand, in order to develop self-adhesion, there is a method of increasing the flexibility of the surface layer by using a soft resin such as an ethylene / vinyl acetate copolymer resin. Although this method certainly improves the self-adhesiveness, it has a drawback that the heat resistance is insufficient. There is also a method in which an additive is contained in the film and bleeding (bleeding) of the additive is used. However, even this method does not reach the necessary self-adhesiveness, and conversely, the increase in the amount of the additive causes a problem that the film surface becomes slimy due to excessive bleeding.

On the other hand, no suitable method has been found at present as a method for expressing a PVDC wrap-like feeling. That is, when a polyamide resin, polyester resin, or polycarbonate resin is used for the surface layer, PVD
Not only does it not give the same feel as C-wrap, but it also makes it difficult to adjust the elasticity and stiffness of the film as a whole.

An object of the present invention is to provide a non-chlorine type laminated wrap having a touch feeling similar to PVDC as a film having a self-adhesion property, heat resistance property and an odor barrier property. .

[0011]

Means for Solving the Problems As a result of intensive studies, the present inventors have used a copolyester having a specific component in both surface layers, and adding a specific amount of a specified fatty acid ester to the copolyester. It was found that the above object can be achieved by the above. That is, the present invention is a laminated wrap film having a tensile elastic modulus of 3000 to 10000 kg / cm ² of the whole film composed of three or more layers consisting of a core layer and both surface layers, wherein both surface layers have the following (A) or ( B) 100 parts by weight of a copolyester having a reduced viscosity of 0.8 to 1.6 dl / g and a melting point of 160 ° C. to 210 ° C., and a compound represented by the formula (II) or the formula (III), or a fatty acid. One or more compounds selected from sorbitan fatty acid esters having 8 to 22 carbon atoms 1.5 to 10
A laminated polyester-based wrap film, characterized by comprising:

(A) A dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol and one or more diols represented by the formula (I). On the other hand, when the diol of m = 2 is less than 0.2 mol%, the amount of 1,4-butanediol is 55-85 mol% and m = 1 of 100 mol% of all diol components excluding the diol of m = 2. 15-45 diol
Mol% of the copolyester (B) a terephthalic acid-based dicarboxylic acid component and a diol component containing 1,4-butanediol and one or more diols of the formula (I), wherein the diol component is For all acid components, the diol with m = 2 is 0.2
When the amount is 3 mol%, 55 mol% of 9,4-butanediol is contained in 100 mol% of all diol components excluding diol of m = 2.
Copolymerized polyester in which 0 mol% and diol of m = 1 are 10 to 45 mol%

[0013]

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M = 1 or 2 When m = 1, n = an integer of 2 to 4 When m = 2, a real number of n = 6 to 55

[0015]

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R: saturated or unsaturated fatty acid (having 8 to 8 carbon atoms)
22) Alkyl residue 1 = integer from 0 to 3

[0017]

[Chemical 6]

R: Saturated or unsaturated fatty acid (having 8 to 8 carbon atoms)
Alkyl residue of 22) Here, the total acid component refers to all polycarboxylic acid components having a carboxyl group that contributes to the ester polycondensation reaction. Hereinafter, the present invention will be described specifically. The wrap film of the present invention is different from the conventional product in that both surface layers are composed of a copolyester of a specific component, and 1 part of the fatty acid ester compound of a specific component is added to 100 parts by weight of the copolymer resin of both surface layers. 0.5 to 10 parts by weight.

First, the above will be described. It is important for the copolyester of the present invention to maintain heat resistance and further maintain crystallinity so as not to impair the odor barrier property. For this reason, terephthalic acid as the dicarboxylic acid component and 1,4 of the diol component are -Butanediol is essential. For this purpose, the proportion of terephthalic acid in the total acid component is 9
It is preferably 0 mol% or more, and the total acid component may be terephthalic acid.

Another essential component of the diol component constituting the copolyester used in the present invention is the formula (I)
A polyethylene diol represented by m = 1 (hereinafter referred to as PEG) and / or a polytetramethylene glycol represented as a diol with m = 2 (hereinafter referred to as PTMG).

[0021]

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When m = 1 or 2 m = 1, n = an integer of 2 to 4 when m = 2, a real number of n = 6 to 55 When PEG is copolymerized, the crystallinity of the obtained polyester is maintained. However, it is possible to soften the composition while keeping the melting point within a specific range, and it is possible to maintain good odor barrier properties. Also, by copolymerizing PTMG, it becomes possible to maintain heat resistance and make it flexible without lowering the melting point of the obtained polyester, and it is possible to improve heat resistance as compared with the case of using PEG alone. become. Therefore, the diols may be used alone or as a mixture, but it is preferable to use both PEG and PTMG.

In the formula (I), the n number of PEG represented as a diol having m = 1 is an integer of 2 to 4, preferably triethylene glycol (n = 3) and tetraethylene glycol (n = 4). Is. When PEG having n of 5 or more as a main component, the odor barrier property is significantly reduced. On the other hand, n of PTMG represented as a diol of m = 2 in the formula (I)
The number is an average value calculated from the number average molecular weight of PTMG, and is a real number of 6 to 55, preferably a real number of 8 to 28. When the average value n is less than 6, the softening effect is poor, and when the average value n is more than 55, the odor barrier property is significantly reduced when copolymerized.

The amount of PTMG in the copolyester used in the present invention is 0 to 3 moles based on the total acid component (all polycarboxylic acid components having a carboxyl group that contributes to the ester polycondensation reaction). %, And preferably 0.2 to 2 mol%. The amount of 1,4-butanediol and PEG in the copolyester used in the present invention is 100 mol% of all diol components excluding PTMG when the amount of PTMG is less than 0.2 mol% with respect to all acid components. 55-85 mol% of 1,4-butanediol, PEG
Is 15 to 45 mol%, preferably 1,4-butanediol is 60 to 80 mol%, and PEG is 20 to 40 mol%. If the amount of PEG is less than 15 mol%, the required flexibility cannot be obtained, and if it is more than 45 mol%, the melting point is low and the required heat resistance cannot be obtained, and the odor barrier property is also reduced.

When the amount of PTMG with respect to the total acid component is 0.2 to 3 mol%, 1,4-butanediol and P are added.
The amount of EG is 55 to 90 mol% of 1,4-butanediol and P of 100 mol% of all diol components excluding PTMG.
TMG is 10 to 45 mol%, preferably 1,4-butanediol is 70 to 85 mol%, and PTMG is 15 to 30 mol%. When the amount of PTMG exceeds 3 mol%, the odor barrier property deteriorates. On the other hand, if the amount of PEG is less than 10 mol% with respect to the total acid component, the required flexibility cannot be obtained.
When it is more than mol%, the melting point becomes low, the required heat resistance cannot be obtained, and the odor barrier property also deteriorates.

The copolymerized polyester used in the present invention may contain components other than the above-mentioned dicarboxylic acids and diols as copolymerization components within the intended range. Examples of the dicarboxylic acid component include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid and sebacic acid, and examples of the diol component include ethylene glycol, polyethylene glycol having a molecular weight of 238 or more, propylene glycol and neo. Mention may be made of pentyl glycol, 1,5-pentanediol and 1,6-hexanediol. It is also possible to copolymerize a small amount of a trifunctional or higher functional carboxylic acid or a hydroxy compound.

If desired, various kinds of lubricants, antiblocking agents, and stabilizers may be added to the copolyester used in the present invention. Particularly in the case of the copolyester used in the present invention, a hindered phenol type,
It is desirable to add antioxidants such as thiopropionate, fatty acid sulfides and disulfides, phosphites and thiophosphites.

The molecular weight of the copolyester used in the present invention thus obtained has a reduced viscosity of 0.8 to
It is specified at 1.6 dl / g, preferably 0.9 to 1.6 dl / g. When the reduced viscosity is less than 0.8 dl / g, the film forming property of the film, particularly the stretchability is poor, and when it exceeds 1.6 dl / g, the film forming property of the unstretched film is deteriorated and the uniformity of the film thickness is deteriorated.

The melting point of the copolyester of the present invention is 1
The temperature is 60 ° C to 210 ° C, preferably 170 ° C to 210 ° C. When the temperature is lower than 160 ° C, the laminated wrap film does not meet the heat resistance requirement when heated in a microwave oven, and the temperature is 210 ° C.
If it exceeds, it becomes difficult to balance the flexibility. The following will be described. In the present invention, it is essential that the copolymerized polyester further contains at least one surfactant having a specific structure having a hydroxyl group. Thereby, a laminated wrap film having excellent self-adhesiveness is obtained. That is, formula (II),
One or more compounds selected from the compound represented by (III) and a sorbitan fatty acid (fatty acid having 8 to 22 carbon atoms) ester are used alone or as a mixture.

[0030]

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R: saturated or unsaturated fatty acid (having 8 to 8 carbon atoms)
22) alkyl residue l = 0 to an integer of 3

[0032]

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R: Saturated or unsaturated fatty acid (having 8 to 8 carbon atoms)
22) Alkyl residue Specifically, as the compound represented by the formula (II), mono-, di-, tri- or tetraglycerin and caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid,
Tridecyl acid, myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, cetoleic acid,
Examples include esters of fatty acids selected from erucic acid, brassic acid, linoleic acid, linolenic acid, and arachidonic acid.
Among them, mono or diglycerin and undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecyl acid,
Esters of fatty acids selected from stearic acid, nonadecanoic acid, oleic acid, linoleic acid and linolenic acid are preferred.

As the compound represented by the formula (III),
Propylene glycol and caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid,
Ester of fatty acid selected from myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, cetoleic acid, erucic acid, brassic acid, linoleic acid, linolenic acid, arachidonic acid Among them, propylene glycol and an ester of a fatty acid selected from undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecyl acid, stearic acid, nonadecanoic acid, oleic acid, linoleic acid, and linolenic acid are preferable.

Examples of the sorbitan fatty acid ester include sorbitan and caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecyl acid, myristic acid, pentadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, undecylenic acid. Acids, oleic acid, elaidic acid, cetoleic acid, erucic acid, brassic acid, linoleic acid, linolenic acid, esters of fatty acids selected from arachidonic acid, among them, sorbitan and undecylic acid, lauric acid, tridecylic acid, myristic acid, An ester of a fatty acid selected from pentadecyl acid, stearic acid, nonadecanoic acid, oleic acid, linoleic acid and linolenic acid is preferable.

These surfactants can be used alone or in admixture of several kinds. The content of the surfactant is 1.5 to 10 parts by weight, preferably 2 to 7.5 parts by weight, based on 100 parts by weight of the copolyester. If it is less than 1.5 parts by weight, the effect of imparting self-adhesion is not sufficient, and if it exceeds 10 parts by weight, the film surface becomes sticky. The film thickness of the laminated wrap film of the present invention is 5 to 20 μm, preferably 5 to 15 μm. If it is thinner than 5 μm, it becomes difficult to handle the film, and if it is thicker than 20 μm, it is difficult to follow the shape of the container and packaging becomes difficult.

The thickness of the copolyester layer of the surface layer is 10 to 45%, preferably 15 to 40% of the total thickness of one surface layer (the total thickness of both surface layers is 20 to 90%). %, Preferably 30 to 80%), if the thickness of the surface layer on one side is less than 10%, it is difficult to uniformly extrude the surface layer, and if it is more than 45%, it is difficult to uniformly extrude the core layer. The film has a poor thickness balance between the layer and the core layer.

The core layer in the present invention satisfies the above-mentioned thickness and has a tensile elastic modulus of 3000 to 10 of the whole film.
It is selected to be 000 kg / cm ² or less. Considering the characteristics of the wrap, the core resin is preferably a resin having heat resistance, odor or water vapor barrier performance, but for example, an aliphatic such as nylon 6, nylon 66, copolymer nylon 6/66, copolymer nylon 6/12, etc. MX produced by polycondensation of polyamide, metaxylylenediamine and adipic acid
Aromatic polyamides such as nylon 6I / 6T produced from nylon, terephthalic acid, isophthalic acid and hexamethylenediamine, polyester resins such as PET and PBT, EVOH, polypropylene and the like can be mentioned.

The touch feeling of the laminated wrap film which uses the copolyester satisfying the above conditions in the surface layer and satisfies the layer constitution conditions is similar to that of PVDC wrap. The layer structure of the wrap film of the present invention has three or more layers composed of both surface layers and a core layer, but may further have another resin layer to have four or more layers. For example, a wrap film having a five-layer structure in which an adhesive layer is provided between the surface layer and the core layer can be used. In this case, the adhesive layer used is
Examples thereof include modified polyolefin resins modified with unsaturated carboxylic acids such as maleic anhydride, and known adhesive polymers such as ionomers.

The method for producing the copolyester used in the present invention and the laminated polyester wrap film of the present invention is not particularly limited. For example, the copolyester is a dicarboxylic acid or its alkyl ester as a component, and an amount corresponding thereto. A diol component is added, and a well-known catalyst such as tetraisopropyl titanate is added, and the well-known polyester polymerization method [“Saturated Polyester Resin Handbook” edited by Kazuo Yuki, Nikkan Kogyo Shimbun (198).
9) etc.].

The copolymerized polyester composition containing the above-mentioned surfactant can be used as a copolymerized polyester by adding the surfactant to a reactor after completion of the polymerization and mixing and then withdrawing it, or by a uniaxial or biaxial extruder. It can also be obtained by kneading the surfactant. The film formation of the laminated polyester-based wrap film of the present invention includes, as a laminating method, a known dry laminating method, an extrusion laminating method, a coextrusion method and the like, and the coextrusion method is preferable. Further, as a film forming method, either extrusion by a flat method using a T die or a tubular method using a circular die is possible.

The film of the present invention is obtained by uniaxially or biaxially stretching, and biaxially stretching is preferable because the anisotropy of tearing of the film becomes small. Further, by stretching, the strength and barrier properties of the film are improved. This stretching method may be either a known tenter method or an inflation method. Further, the stretched film can be heat-set under appropriate conditions.
The heat shrinkage rate of the film can be adjusted by the heat setting conditions.
The wrap film preferably has a small heat shrinkage ratio,
It is preferable to perform heat setting treatment at a temperature of (melting point-50 ° C) to (melting point-10 ° C) of the copolyester of the surface layer for 1 second or more and 30 minutes or less.

[0043]

EXAMPLES In the following, in order to specifically describe the present invention in Examples, measurement and evaluation methods and the like will be described below. (Composition mol%) It was measured by 270 MHz ¹ HNMR (JEOL) using trifluoroacetic acid / deuterochloroform (1/2 weight ratio) as a solvent for the copolyester.

(Reduced viscosity) It was measured using an Ostwald viscometer at a concentration of 0.1 g / dl and 25 ° C. using orthochlorophenol as a solvent. (Melting point) The peak value of the melting exothermic peak measured with a DSC (DSC7 manufactured by Perkin Elmer Co., Ltd.) at a heating rate of 20 ° C./min was taken as the melting point.

(Number average molecular weight of PTMG) n of PTMG
The number average molecular weight (M) for determining the value of was calculated by M = 112200 / OH value based on the measurement of the hydroxyl value (OH value) of PTMG.

For the OH value, pyridine / acetic anhydride = 3/1 (volume / volume) was added to the sample, the mixture was heated in a boiling water bath for about 2 hours to acetylate, and then the sample was diluted with pyridine, water and ethanol. And phenolphthalein as an indicator,
It was measured by titrating with a N / 2 alcoholic potassium hydroxide solution. (Tensile elastic modulus) Performed according to ASTM D-882, 2
A value obtained by converting the stress at the time of% elongation to 100% was used.

(Self-adhesion) The films are tensioned and fixed so that no wrinkles are formed on one of the bottom surfaces of the two cylinders having a bottom area of 25 cm ² so that the film surfaces overlap each other. The bottom surfaces of the two cylinders were aligned and pressure-bonded with a load of 500 g for 1 minute, and then the films were separated from each other in a direction perpendicular to the surface, and the energy required at that time was measured. The suitable value of the adhesiveness is 8 g · cm or more, and was evaluated in three grades of ⊚, ◯, and × according to the following criteria. The unit of the evaluation standard is g · cm symbol Evaluation standard Content ◎ 12 or more Very self-adhesive.

○ 8 or more and less than 12 There is self-adhesion. × Less than 8 No self-adhesion. (Odor barrier property) As an odor substance, sardines, lemons, curry roux, and lacquer pickles are used.
g is placed in an individual petri dish with a diameter of 6 cm, and after lapping, the petri dish is separately placed in a 6-liter stainless steel container, sealed, and stored in a refrigerator (internal temperature 5 ° C.) for 3 days, then taken out,
The lid of the stainless steel container was opened, and the odor in the container was evaluated by sensory evaluation. The evaluation was carried out by 10 panelists.

The sensory test was evaluated in 6 levels with reference to the 6-level odor intensity labeling method in the basic policy concerning the designation of odorous substances and the setting of the range of odor control standards by the Central Pollution Control Council. The contents are shown below. Odor intensity Content 0 No odor 1 Smell that can be finally sensed 2 Weak odor that understands what odor 3 Smells easily.

4 Strong odor 5 Strong odor The odor barrier property of the wrap film averages the odor intensity of each odor substance stored for 3 days, and a level lower than the odor intensity 3 (easily perceivable odor) can withstand practical use. Assuming that it has an odor barrier property, it was evaluated in the following three grades of ◎, ○, and ×.

Symbol Evaluation Criteria Content ◎ Less than 2 Very excellent in barrier properties. ○ 2 or more and less than 3 It has a barrier property that can withstand actual use. × 3 or more The barrier property is insufficient and the odor leaks. (Heat resistance) A strip of film sample having a width of 30 mm and a length of 140 mm is placed on the top and bottom 25 mm of a strip-shaped film sample piece, and a weight of 10 g is lowered. The film was hung in an air oven adjusted to a constant temperature for 1 hour, and the maximum atmospheric temperature at which the film did not break was measured in steps of 5 ° C (unit: ° C). The higher this temperature, the better the microwave suitability.

Symbol Evaluation Criteria Content ◎ 170 or more Excellent in microwave oven suitability. ○ 140 or more and less than 170 Excellent in microwave oven suitability. × Less than 140 Poor in microwave oven suitability. (Feeling Feeling) Whether the actual feeling of feeling of the film is similar to that of PVDC wrap (Saran wrap: trade name) was evaluated sensory by 10 panelists. The criteria are as follows: 5 criteria Criterion 5 Very similar to PVDC wrap.

4 Very similar to PVDC wrap. 3 Similar to PVDC wrap. 2 Different from PVDC wrap. 1 Very different from PVDC wrap. (Resin used) The resins used in Examples and Comparative Examples are shown below. -Nylon 6 (hereinafter referred to as 6-Ny, the same applies hereinafter), Mitsubishi Chemical Corporation Novamid 1030: melting point 224 ° C.
-MX Nylon (MXD6) Mitsubishi Gas Chemical Co., Ltd., MX Nylon 6007: melting point 2
40 ° C.-Polypropylene (PP) UBE PolyPro F102LA: UBE Polypro F102LA: Density 0.90 g / cm ³ -Propylene / Ethylene Random Copolymer (PP) Mitsubishi Chemical Corporation Mitsubishi Polypro 6500J: Density 0.
89 g / cm ³ · Propylene / Ethylene / Butene-1 Random Copolymer (PP) Mitsubishi Chemical Co., Ltd. Mitsubishi Polypro SPX4400: Density 0.90 g / cm ³ · Thermoplastic Polyesters (PEs) Kanebo Co., Ltd. Belpet IFG-8L: Melting point 226 ° C. Aromatic polycarbonate (PC) Mitsubishi Gas Chemical Co., Inc., Iupilon E-2000: Heat distortion temperature 145 to 155 ° C. (Production of copolymerized polyester) Copolymer used in the present invention The polyester is as follows (Tables 1 and 2).

[No. 1] Dimethyl terephthalate 100 parts by weight 1,4-butanediol 80.1 parts by weight Triethylene glycol 44.5 parts by weight Pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) 0.06 part by weight of Ropionate] was charged into a stainless steel reactor, heated to 150 ° C. to dissolve the contents, tetraisopropyl titanate was added as a catalyst, and methanol and by-product generated while heating up to 220 ° C. The transesterification reaction was carried out for 3 hours while introducing tetrahydrofuran to the outside of the system. Furthermore, after adding tetraisopropyl titanate, the reactor was evacuated to a high vacuum of 1 mmTorr or less over 1 hour, and at the same time 240 ° C.
Temperature. Thereafter, high vacuum of 1 mmTorr or less, 2
The condensation reaction was continued for 6 hours at 40 ° C.

The polymer thus obtained is 69 mol% of 1,4-butanediol in 100 mol% of all diols,
Triethylene glycol 31 mol%, reduced viscosity 1.2
dl / g, melting point 181 ° C. [No. 2-No. 5] No. Similarly to 1, copolymerized polyesters having different amounts of diethylene glycol, triethylene glycol or tetraethylene glycol were synthesized. The amount of pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was made to be about 0.05 part by weight in the polymer. The composition, reduced viscosity and melting point of the obtained polymer are shown in Table 1.
It is as follows.

In Table 1, TPA is terephthalic acid, B
D represents 1,4-butanediol, DEG represents diethylene glycol, TEG represents triethylene glycol, and TeEG represents tetraethylene glycol.

[0057]

[Table 1]

[No. 6] Dimethyl terephthalate 100 parts by weight 1,4-butanediol 85.4 parts by weight Triethylene glycol 35.6 parts by weight PTMG (number average molecular weight 1000) 2.57 parts by weight Pentaerythyl-tetrakis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) prop 0.06 parts by weight Ropionate] was charged into a stainless reactor and heated to 150 ° C. to dissolve the contents, and tetraisopropyl titanate was added as a catalyst. While raising the temperature to 0 ° C., the produced ester and the by-produced tetrahydrofuran were introduced to the outside of the system to carry out the transesterification reaction for 2.5 hours. After adding tetraisopropyl titanate, the reactor was evacuated to a high vacuum of 1 mmTorr or less over 1 hour, and at the same time 240
The temperature was raised to ° C. After that, a high vacuum of 1 mmTorr or less,
The condensation reaction was continued for 6 hours at 240 ° C.

The polymer obtained in this way was 75 mol% of 1,4-butanediol in 100 mol% of all diols.
25 mol% of triethylene glycol, PTMG has a composition of 0.6 mol% (converted to a molecular weight of 1000) with respect to 100 mol% of a terephthalic acid component, and a reduced viscosity of 1.0 dl /
g, melting point 189 ° C. [No. 7-No. 12] No. Similar to 6, a copolyester having a different PTMG molecular weight and composition and a diethylene glycol, triethylene glycol or tetraethylene glycol composition was synthesized. The amount of pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was made to be about 0.05 part by weight in the polymer. Table 2 shows the composition, reduced viscosity, and melting point of the obtained polymer.

In Table 2, TPA is terephthalic acid, B
D is 1,4-butanediol, DEG is diethylene glycol, TEG is triethylene glycol, TeEG is tetraethylene glycol, and PTMG is polytetramethylene glycol (composition is converted to number average molecular weight).

[0061]

[Table 2]

[0062]

Example 1, Comparative Example 1 Example 1: RUN No. 1 to 4 Comparative Example 1: RUN No. 5, 6 RUN No. 1: Copolyester N shown in Table 1
o. 100 parts by weight of 1 and 5 parts by weight of soulbitan laurate were kneaded with a 25 mm twin-screw extruder to obtain a copolyester composition. This composition is used as a surface layer and a core layer 6-
Ny (trade name Novamit 1033; melting point 224 ° C.) is used, a 40 mm extruder and a T die are used, and the resin temperature is 250.
Simultaneous extrusion at 0 ° C. to obtain a two-kind three-layer unstretched film having a surface layer (copolymerized polyester composition) / core layer (6-Ny) / surface layer (copolymerized polyester composition) = 40/20/40 μm. . Furthermore, using a biaxial stretching device,
Simultaneous biaxial stretching was carried out at a speed of 300% / min to 3.2 × 3.2 times. Next, this stretched film was fixed to a frame and heat-set in an oven at 140 ° C. for 90 seconds to obtain a film of 10 μm. Table 3 shows the evaluation results.

RUN No. 2 to 6: No. The sorbitan laurate was added to 100 parts by weight of the 1-copolymerized polyester.
Knead the mixing part (part by weight) in 6 to form 6-Ny in the core layer.
RUN No. Film formation, stretching and heat setting were carried out in the same manner as in 1 to obtain a 10 μm film. However, No. 3 is not heat set. Table 3 shows the evaluation results.

[0064]

Example 2 and Comparative Example 2 Example 2: RUN No. 7 Comparative Example 2: RUN No. 8 RUN No. 7: Copolyester N shown in Table 1
o. 100 parts by weight of 2 and 5 parts of diglycerin monooleate
The mixture was kneaded with a 25 mm twin-screw extruder in an amount of 25 parts by weight to obtain a copolyester composition. This composition is used as a surface layer and a core layer in P
P (trade name UBE polypro F102LA; density 0.9
0 g / cm ³ ), a 40 mm extruder and a T-die are used to simultaneously extrude at a resin temperature of 250 ° C. to obtain a surface layer (copolymerized polyester composition) / core layer (PP) / surface layer (copolymerized polyester composition). ) = 40/20/40 μm, a two-kind three-layer unstretched film was obtained. Further, using a biaxial stretching device, simultaneous biaxial stretching was carried out at 70 ° C. at a rate of 300% / min to 3.2 × 3.2 times. Next, this stretched film was fixed to a frame and heat-set in an oven at 150 ° C. for 90 seconds to obtain 10 μm.
m was obtained. Table 3 shows the evaluation results.

RUN No. 8: Copolyester No. 7 on the surface layer 2. PP is used for the core layer and RUN No. 7
The film was formed and stretched in the same manner as in 1. to obtain a film having a thickness of 10 μm. However, there is no heat fixation. Table 3 shows the evaluation results.

[0066]

Third Embodiment RUN No. 9-11 Various copolymerized polyesters were kneaded with a predetermined amount of some compounds to obtain a copolymerized polyester composition. Copolyester No. used Table 3 shows the kneaded compound, and the number of mixed parts (parts by weight) based on 100 parts by weight of the copolyester. The obtained copolyester composition was used as the surface layer and 6-Ny was used as the core layer.
No. A film was formed in the same manner as 1. 3.2 × a two-kind three-layer unstretched film consisting of the obtained surface layer (copolymerized polyester composition) / core layer (6-Ny) / surface layer (copolymerized polyester composition) = 40/20/40 μm. 3.2 times 2 at the same time
Axial stretching, heat setting in an oven at 140 ° C. for 90 seconds, 10
A μm film was obtained. Table 3 shows the evaluation results.

As shown in Table 3, the wrapping film of the present invention satisfying the requirements for the layer constitution by using the copolymerized polyester of the specific component containing the specific fatty acid ester compound in the surface layer has self-adhesiveness and odor barrier. A film with excellent heat resistance and heat resistance. However, when the content of the fatty acid ester compound is low, the film obtained has insufficient self-adhesiveness and poor feel to the touch.

[0068]

[Table 3]

[0069]

Example 4, Comparative Example 3 Example 4: RUN No. 12 to 14 Comparative Example 3: RUN No. 15 RUN No. 12: Copolyester N shown in Table 2
o. 100 parts by weight of 6 and 2 parts by weight of sorbitan laurate were kneaded with a 25 mm twin-screw extruder to obtain a copolyester composition. PP as the surface layer and the core layer
Using a 40 mm extruder and a T-die with a resin temperature of 2
Simultaneous extrusion was performed at 50 ° C. to obtain a two-kind three-layer unstretched film having a surface layer (copolymerized polyester composition) / core layer (PP) / surface layer (copolymerized polyester composition) = 40/20/40 μm. Furthermore, using a biaxial stretching device,
Simultaneous biaxial stretching was carried out at a speed of 300% / min to 3.2 × 3.2 times. Next, this stretched film was fixed to a frame and heat-set in an oven at 150 ° C. for 90 seconds to obtain a film of 10 μm. Table 4 shows the evaluation results.

RUN No. 13 to 15: No. 6 Copolymerized polyester 100 parts by weight was kneaded with sorbitan laurate at the mixing part number (parts by weight) shown in Table 4, and the core layer was made of PP.
RUN No. Film formation, stretching and heat setting were performed in the same manner as in 12 to obtain a 10 μm film. Table 4 shows the evaluation results.

[0071]

Example 5 Example 5: RUN No. 16 to 21 Various compounds were kneaded in a predetermined amount with various copolymer polyesters to obtain copolymer polyester compositions. Copolyester No. used , The kneaded compound and
Table 4 shows the number of parts (parts by weight) mixed with 100 parts by weight of the copolyester. The obtained copolyester composition was used as the surface layer and 6-Ny was used as the core layer.
o. A film was formed in the same manner as 12. 3.2 × a two-kind three-layer unstretched film having the obtained surface layer (copolymerized polyester composition) / core layer (6-Ny) / surface layer (copolymerized polyester composition) = 40/20/40 μm. 3.2 times 2 at the same time
Axial stretching, heat setting for 90 seconds in an oven at 150 ° C for 10
A μm film was obtained. Table 4 shows the evaluation results.

As shown in Table 4, the wrap film of the present invention satisfying the requirements for the layer constitution by using the copolymerized polyester of the specific component containing the specific fatty acid ester compound in the surface layer has self-adhesiveness and odor barrier. A film with excellent heat resistance and heat resistance. However, when the content of the fatty acid ester compound is low, the resulting wrap film has insufficient self-adhesiveness and poor feel to the touch.

[0073]

[Table 4]

[0074]

Example 6 Example 6: RUN No. 22-25 Copolymerized polyester was kneaded with a predetermined amount of sorbitan laurate to obtain a copolymerized polyester composition. Copolyester No. used Table 5 shows the number of mixed parts (parts by weight) of the kneaded compound with respect to 100 parts by weight of the copolyester. The obtained copolyester composition was used for the surface layer and 6-Ny, P for the core layer as shown in Table 5.
P, MXD6 (Brand name MX Nylon 6007; melting point 2
40 ° C.), a 40 mm extruder and a T die are used to simultaneously extrude at a resin temperature of 270 ° C., surface layer (copolymerized polyester composition) / core layer / surface layer (copolymerized polyester composition) = 40/20 A two-kind three-layer unstretched film having a thickness of / 40 μm was obtained. Furthermore, using a biaxial stretching device, 70 ° C, 3
Simultaneous biaxial stretching was carried out at a speed of 00% / min to 3.2 × 3.2 times. Next, this stretched film was fixed to a frame and heat-set in an oven at 150 ° C. for 90 seconds to obtain a film of 10 μm. Table 5 shows the evaluation results.

[0075]

Comparative Example 4 Comparative Example 4: RUN No. 26-29 RUN No. 26: 100 parts by weight of PP (trade name Mitsubishi Polypro 6500J; density 0.89 g / cm ³ ) in the surface layer, polybutene 2 having an average molecular weight of 780 as a tackifier
25 parts by weight of 0 part by weight and 1 part by weight of monolauryl glycerin
The composition was kneaded with a twin-screw extruder to obtain a PP composition. This PP
The composition is used as a surface layer, 6-Ny is used as a core layer, a 40 mm extruder and a T die are used to simultaneously extrude the composition at a resin temperature of 270 ° C. to obtain a surface layer (PP composition) / core layer (6-Ny) / surface. Layer (PP composition) = 40/20/40 μm 2
A seed 3-layer unstretched film was obtained. Further, using a biaxial stretching device, simultaneous biaxial stretching was performed at 50 ° C. and a speed of 300% / min to 3.2 × 3.2 times. Next, this stretched film was fixed to a frame and heat-set in an oven at 110 ° C. for 90 seconds to obtain 10 μm.
m was obtained. Table 5 shows the evaluation results.

RUN No. 27: PP on the surface layer (trade name: Mitsubishi Polypro SPX4400; density 0.90 g / c
m ³ ) 94 parts by weight and 6 parts by weight of polyglycerin oleate as a tackifier were kneaded with a 25 mm twin-screw extruder to obtain a PP composition. This PP is used as a surface layer and PEs is used as a core layer (trade name: Velpet IFG-8L; melting point 226).
C.) using a 40 mm extruder and a T-die at a resin temperature of 250.degree. C. at the same time, and surface layer (PP composition) / core layer (PEs) / surface layer (PP composition) = 5.5 / 2 /
A 2-kind 3-layer unstretched 13 μm film having a thickness of 5.5 μm was obtained. Table 5 shows the evaluation results.

RUN No. 28: PP94 on the surface layer
PP by kneading 6 parts by weight of polyglycerin oleate as a tackifier with a 25 mm twin-screw extruder
A composition was obtained. This PP composition is used for the surface layer and P for the core layer.
C (trade name Iupilon E-2000; heat distortion temperature 145
˜155 ° C.) using a 40 mm extruder, T-die,
Simultaneous extrusion at a resin temperature of 260 ° C., surface layer (PP composition) / core layer (PC) / surface layer (PP composition) = 5.5
A two-kind three-layer unstretched 13 μm film having a thickness of /2/5.5 μm was obtained. Table 5 shows the evaluation results.

RUN No. 29: Hitachi Boden Co., Ltd.
Made, view wrap [trade name, polyethylene (PE) resin / polypropylene (PP) resin / polyethylene (P
Table 5 shows the evaluation results of [E) Three-layer film made of resin.

[0079]

[Reference Example 1] RUN No. 30: Asahi Kasei Co., Ltd.
Table 5 shows the evaluation results of the Saran Wrap (trade name, PVDC single layer) manufactured by the company. As shown in Table 5, the laminated polyester wrap film of the present invention is superior in self-adhesiveness and touch feeling, and is also excellent in odor barrier property and heat resistance, as compared with a multilayer wrap film using a polyolefin resin on the surface. It is a thing.

[0080]

[Table 5]

[0081]

As described above, the laminated polyester wrap film of the present invention has a feeling of touch similar to PVDC, self-adhesiveness,
It retains heat resistance and odor barrier properties and is suitable as a film for packaging foods and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08L 67/03 C08L 67/03 // B29K 67:00 B29L 9:00

Claims (1)

[Claims] 1. The tensile modulus of elasticity of the entire film composed of three or more layers consisting of a core layer and both surface layers is 3000 to 100.
In the laminated wrap film of 00 kg / cm ² , the above-mentioned both surface layers are the following (A) or (B), and the reduced polyester has a reduced viscosity of 0.8 to 1.6 dl / g and a melting point of 160 ° C. to 210 ° C. 1.5 parts by weight of the compound represented by the formula (II) or the formula (III), or one or more compounds selected from sorbitan fatty acid esters having 8 to 22 carbon atoms in the fatty acid. A characteristic laminated polyester wrap film. (A) A dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol and one or more diols represented by the formula (I). 0.2 for diol with m = 2
When it is less than mol%, 1,4-butanediol is 55 to 8 in 100 mol% of all diol components excluding m = 2 diol.
Copolyester having 5 mol% and 15 to 45 mol% of m = 1 diol (B) dicarboxylic acid component containing terephthalic acid as a main component, 1,4-butanediol and one or more of the formula (I) Of the diol component including the diol, the diol component having a ratio of m = 2 is 0.2
When the amount is 3 mol%, 55 mol% of 9,4-butanediol is contained in 100 mol% of all diol components excluding diol of m = 2.
Copolymerized polyester in which 0 mol% and diol of m = 1 are 10 to 45 mol% m = 1 or 2 When m = 1, an integer of n = 2 to 4 When m = 2, a real number of n = 6 to 55 R: an alkyl residue of a saturated or unsaturated fatty acid (having 8 to 22 carbon atoms) 1 = 0 to an integer of 3 R: Alkyl residue of saturated or unsaturated fatty acid (C8-22)