JPH11116787A - Wrap film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a film which is excellent in practical adhesiveness and odor barrier properties by compounding a polytrimethylene terephthalate resin with a specified amt. of a compd. selected from among 8-22C fatty acid glycerides, sorbitan fatty acid esters, rosin esters, and polyterpene resins. SOLUTION: A polytrimethylene terephthalate resin obtd. from a dicarboxylic acid component contg. at least 90 mol.% terephthalic acid and a diol component contg. 55-100 mol.% propanediol, a compd. of formula I, etc., is compounded with 1-10 wt.% at least one compd. selected from among compds. of formulas II and III, 8-22C fatty acid glycerides, sorbitan fatty acid esters, rosin esters, and polyterpene resins, thus giving the objective compsn. A wrap film obtd. by forming the compsn. has a tensile modulus of 3,000-15,000 kg/cm<2> at an average thickness of 2-50 μm. In the above formulas, l is 0-3; m is 1-2; n is 2-4; and R is an alkyl residue of an 8-22C fatty acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrap film used for directly wrapping food in a household or in a container such as a dish, or the food itself, and more specifically, a polytrimethylene terephthalate resin. Related to wrap film.

[0002]

2. Description of the Related Art Wrap films are used in many ordinary households as simple packaging materials for various foods. Conventionally, wrap film is mainly tableware placed on a table,
Used to avoid dust on food, and in refrigerators, cover the container with the food with a wrap film and cover the container with the food to prevent the smell of the food from transferring to other foods. It has been used to keep food fresh. In such a use form, in order to cover the container efficiently, it is generally required that the container has good adhesion and ease of use. This can be easily understood by comparing the vinylidene chloride wrap and the single-layer polyethylene wrap.However, if the wrap film has firmness and stiffness, it is very easy to wrap the container or cover the container. . Further, in order to prevent odor transfer, a barrier property against odor molecules is required. In addition, water barrier properties and the like are also required as one of the factors for maintaining the freshness of food. For this reason, vinylidene chloride wraps satisfying all of these characteristics are now widely used.

[0003] However, in recent years, microwave ovens have been widely used due to a decrease in prices of electric appliances. For this reason, cooking in a microwave oven has been diversified, and a wrap having high heat resistance, which can be used for cooking requiring heating for a long time, has been required. The vinylidene chloride wrap can be used for cooking using an ordinary microwave oven, but may break when heated for a long time.

On the other hand, as a film having heat resistance, a polyester film has been conventionally known. Among them, polytrimethylene terephthalate (polypropylene terephthalate) is more flexible than polyethylene terephthalate as disclosed in JP-A-8-325391, and its potential as a packaging film for industrial parts and the like has been studied. Was. However, since the wrap film has no adhesion performance, it has hardly been studied as a wrap film, and it is far from practical use.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wrap film having high practical heat resistance and having excellent practical adhesion, stiffness and odor barrier properties.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have high heat resistance.
The inventors have found a wrap film made of a polytrimethylene terephthalate-based resin having excellent adhesiveness and having both a feeling of harshness and an odor barrier property, and have accomplished the present invention. That is, the present invention comprises a polytrimethylene terephthalate resin mainly containing a dicarboxylic acid component containing terephthalic acid as a main component and 1,3-propanediol as a diol component, and has the following formulas (1) and (2). A wrap film comprising 1 to 10% by weight of at least one compound selected from the group consisting of a sorbitan fatty acid ester having 8 to 22 carbon atoms, a rosin ester and a polyterpene resin, wherein the compound and the fatty acid have 8 to 22 carbon atoms. is there.

[0007]

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Hereinafter, the present invention will be described in detail. The present invention differs from the prior art in that it comprises a specific polytrimethylene terephthalate-based resin and contains a specific amount of a specific compound. The technical significance of these differences is as follows. Usually, a wrap film is used in ordinary households as a cover or cover for containers such as glass, plastic, and ceramics. The outline of the operation when using the wrap film is as follows (I), (II),
This can be explained by (III) and (IV). (I) The wrap film is pulled out of the box by the required area from the end. (II) It is cut off using a blade attached to the box. (III) Cover the container with a wrap film. (IV) Press the peripheral part against the side of the container and attach the remaining part.

Here, when the above-mentioned operation (III) is performed, it is necessary that the wrap film of the portion serving as the lid of the container is stretched. If the wrap film is not stretched, after the above operation (IV) is completed, a gap is formed between the wrap film and the container, and odors and the like leak from the gap.
Therefore, this stretched state is necessary. This stretched state is expressed as “stiffness”. In addition, when performing the above-mentioned operation (II), if the wrap film does not have a certain degree of rigidity, the cutting property is deteriorated. The hardness at this time is expressed as a “stiff” feeling. Therefore, firmness and firmness are important in a wrap film. As a result of various studies conducted by the present inventors, according to a film made of a polytrimethylene terephthalate resin containing a specific compound in an amount of 1 to 10% by weight, the practical heat resistance can be further improved without impairing the firmness and firmness. It was found that a wrap film having both practical adhesion and odor barrier properties could be provided.

[0010] The wrap film is usually 10 m to 10 m.
It is provided to general consumers in a state of being wound 0 m. After production, the wrap film may shrink due to storage conditions or the like before the wrap film product is delivered to the general consumer, and the wound state may be strongly tightened. When the wound state is tightened, the take-out property deteriorates. Regarding this problem, it has been found that the use of a polytrimethylene terephthalate-based resin for a wrap film is more effective than, for example, other ester-based resins (for example, polybutylene terephthalate-based resin or the like, for example) or a single-layer polyethylene wrap film. .

The polytrimethylene terephthalate resin used in the present invention mainly contains a dicarboxylic acid component containing terephthalic acid as a main component and 1,3-propanediol as a diol component. The intrinsic viscosity of the polytrimethylene terephthalate resin used in the present invention is not particularly limited, but from the viewpoint of film formability and stretchability is 0.6 to 1.5.
It is preferred that The intrinsic viscosity is a value measured at 25 ± 0.5 ° C. using a capillary type solution viscometer with a solvent in which the polytrimethylene terephthalate resin is soluble and a solution concentration of 0.5 g / dL. It is. As the solvent, for example, in the case of a homopolymer, a 1: 1 mixture of methylene chloride and trifluoroacetic acid is used, and in the copolymer, a 1: 1 mixture of methylene chloride and trifluoroacetic acid, and ethane tetrachloride are used. Either a 1: 1 mixture with phenol or orthochlorophenol is used.

In the polytrimethylene terephthalate resin used in the present invention, the proportion of terephthalic acid in the total acid component is preferably 90 mol% or more, and the total acid component may be terephthalic acid. Acid components other than terephthalic acid include, for example, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like. The polytrimethylene terephthalate resin used in the present invention mainly contains 1,3-propanediol as a diol component. Here, the content of 1,3 propanediol is preferably 55 to 100 mol per 100 mol of the diol component. In order to further impart flexibility to the polytrimethylene terephthalate-based resin used in the present invention, one kind represented by the following formula (3) other than 1,3-propanediol as a diol component may be used, if necessary. The above diol may be contained.

[0013]

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Here, when the odor barrier property is particularly required, when the diol having m = 2 is not used, 1,3-propanediol is 55 mol or more in 100 mol of all diol components when 100 mol of all diol components are not used. 79 mol or less, m =
One diol may be used in an amount of 21 mol or more and 45 mol or less in 100 mol of all diol components. More preferably, m = 1
May be used in an amount of 21 mol or more and 30 mol or less in 100 mol of all diol components. When the diol of m = 2 is 0.01 mol or more and less than 0.2 mol with respect to 100 mol of all the acid components, the diol of m = 2 is preferred from the viewpoints of odor barrier property, firmness, firmness, and practical heat resistance. All diol components except for 1
It may be preferable that 1,3-propanediol is 55 mol or more and 85 mol or less, and the diol having m = 1 is 15 mol or more and 45 mol or less in 00 mol.

When the diol of m = 2 is 0.2 mol or more and 3 mol or less with respect to 100 mol of all acid components, the diol of m = 2 is preferred from the viewpoints of odor barrier property, firmness, firmness and practical heat resistance. It may be more preferable that 1,3-propanediol is 55 mol or more and 90 mol or less and the diol having m = 1 is 10 mol or more and 45 mol or less in 100 mol of all diol components except for the above. Here, the total acid component refers to all the polycarboxylic acid components having a carboxyl group that contribute to the ester double bond reaction. Examples of the diol represented by m = 2 include polytetramethylene glycol. In the formula (3), in the case of polytetramethylene glycol, the number n is an average value calculated from the number average molecular weight, and is a real number of 6 to 55, preferably a real number of 8 to 28. In the polytrimethylene terephthalate resin used in the present invention, polyethylene glycol having a molecular weight of 238 or more, neopentyl glycol, 1,5-pentadiol, and 1,6-hexanediol may be used within the scope of the present invention. good.

In the present invention, in order to use the polytrimethylene terephthalate film as a wrap film, it is essential to include a compound having a specific structure. That is, it may contain one or more compounds selected from the group consisting of the compounds represented by the above formulas (1) and (2), sorbitan fatty acid esters having 8 to 22 carbon atoms of fatty acids, rosin esters, and polyterpene resins. is necessary. The number of carbon atoms of the compounds represented by the general formulas (1) and (2) and the fatty acid component constituting the sorbitan fatty acid ester is generally 8 to 2
2, preferably 8 to 18. General formula (1)
L in the above is an integer of 0 to 3, preferably 0 or 1. Specific examples of the compound represented by the general formula (1) include mono, di, tri or tetraglycerin and caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, and stearic acid. , Nonadecanoic acid, arachinic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, setrenic acid, erucic acid, brassic acid, linoleic acid, linolenic acid, esters of fatty acids selected from arachidonic acid, among which mono or di Glycerin and undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, oleic acid,
Esters of fatty acids selected from linoleic acid and linolenic acid are preferred.

As the compound represented by the general formula (2),
Propylene glycol and caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid,
Esters of fatty acids selected from myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, arachiic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, setreic acid, escaic acid, brassic acid, linoleic acid, linoleic acid, and arachidonic acid Among them, propylene glycol and undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, stearic acid,
Esters of fatty acids selected from nonadecanoic acid, oleic acid, linoleic acid and linolenic acid are preferred.

Sorbitan fatty acid esters include sorbitan and caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid,
Esters of fatty acids selected from pentadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, setreic acid, erucic acid, brassic acid, linoleic acid, linolenic acid, arachidonic acid Among which sorbitan and undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, oleic acid,
Fatty acid esters selected from linoleic acid and linolenic acid are preferred. The compounds can be used alone or as a mixture of several types.

Although the rosin ester is not particularly limited, examples thereof include methyl ester rosin, hydrogenated methyl ester rosin, glycerin ester rosin, hydrogenated glycerin ester rosin, perhydrogenated glycerin ester rosin, pentaerythritol rosin, water Pentaerythritol rosin, hydrogenated pentaerythritol rosin,
And glycerol esters of polymerized rosin. When a polyterpene resin is used, either a natural type or a synthetic type may be used. It is essential that the content of the above compound is 1 to 10% by weight based on the polytrimethylene terephthalate resin.
In some cases, it is preferable that the content be contained in an amount of about 8% by weight. 1% by weight
If the amount is less than 10%, the adhesiveness may not be sufficient. If the content exceeds 10% by weight, a large amount is present on the surface of the wrap film.

The compound may be mixed with the polytrimethylene terephthalate resin of the present invention to form a film, or may be applied during or after the production of a wrap film. The wrap film of the present invention may contain additives such as a plasticizer, an antioxidant, a lubricant, and an anti-blocking agent as long as the purpose as the wrap film is not impaired, in addition to the above compounds. When a plasticizer is used to impart flexibility, for example, a phthalate plasticizer (for example, dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate, etc.), an aliphatic dibasic ester plasticizer (for example, sebacine) Dibutyl acrylate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, etc.) and phosphate plasticizer (eg, diphenyl 2-ethylhexyl phosphate etc.) in the range of 2 to 7% by weight. Is also good. The plasticizer can be used alone or as a mixture of several types.

When an antioxidant is used, a hindered phenol (for example, pentaerythyl-tetrakis [3]
-(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] and the like. ), Thiopropionate, fatty acid sulfide, phosphite, thiophosphite, etc.
It may be contained alone or in a mixture of several kinds in the range of ppm. When a lubricant (for example, calcium stearate, magnesium stearate, stearic acid, liquid paraffin, butyl stearate, monoglyceride stearate, etc. is used), 10 to 300 p
You may make it contain in the range of pm.

Anti-blocking agent (for example, amorphous silica containing silicon dioxide (SiO 2 · nH 2 O) as a main component: average particle size (coulter counter method) 1.0 to
When 3.6 micron, and more preferably 1.0 to 2.0 micron is more preferable, these may be used. Furthermore, it may be more preferable that the content is 5 to 250 ppm. Conventionally, wrap products are provided to general consumers in a state of being wound on a paper tube of 10 m to 100 m. When used, when the wrap film is taken out from the rolled state, the films may strongly adhere to each other due to the influence of the storage temperature or the like.
In this case, the film may not be taken out in a normal state and the film may be broken. In this case, it may be effective to add an antiblocking agent.

The tensile elastic modulus of the wrap film of the present invention is:
It may be preferred 3000 kg / cm ² or more 15,000 kg / cm ² or less. 3000kg /
It may be more preferable that the pressure is not less than cm ^{2 and not} more than 10,000 kg / cm ² . If the tensile modulus is less than 3000 kg / cm ² , the feeling of stiffness may be easily lost, and if the tensile modulus exceeds 15000 kg / cm ² , packaging may be difficult depending on the container to be put on practically.

The average thickness of the wrap film of the present invention is 2
In some cases, it is preferable that the thickness is not less than μm and not more than 50 μm. Further, it may be more preferable that the thickness be 3 μm or more and 30 μm or less. In particular, it may be more preferable that the thickness be 5 μm or more and 25 μm or less. If the thickness is less than 2 μm, it may be difficult to handle as a wrap film.
When the thickness is more than μm, the followability to the shape of the container is poor, and it may be difficult to cover the container. Further, the wrap film according to the present invention has an excellent odor barrier property against odors of foods usually stored in a refrigerator, such as sardine, lemon, curry roux, pickled radish, etc., compared with, for example, commercially available single-layer polyethylene wraps.

There are various methods for producing the wrap film of the present invention, but a preferred example of the production method will be described with respect to the successive biaxial stretching method and the inflation method. The resin used may or may not be a composition in which the compound of the present invention is previously mixed.
In the sequential biaxial stretching method, any one of the resin compositions or resins is dried, then melted at a temperature equal to or higher than the melting point, and extruded in a molten state from a single-layer die using a single-screw or twin-screw extruder. The extruded molten resin is rapidly cooled and solidified by a casting drum. At this time, when charge is required, an application process may be performed. Next, at a temperature of 40-100 ° C in the vertical direction,
Stretching is performed using a roll stretching machine at a stretching ratio of 1.1 to 5 times. Next, after cooling and pre-heat treatment at 40 to 100 ° C., stretching is performed using a tenter in the transverse direction at a temperature of 40 to 120 ° C. and a stretching magnification of 2 to 6 times. Further, heat treatment is performed while relaxing at 80 to 200 ° C. Next, the film is wound up and, if necessary, slit to obtain a raw wrap film.
Finally, the raw wrap film is rewound to a predetermined width and length to obtain a wrap film. When applying the compound of the present invention, it may be applied in any step after quenching with a casting drum.

Next, the inflation method will be described. Any one of the resin compositions or resins is supplied to a melt extruder and melted, extruded into a tube from a single-layer annular die attached to the tip of the extruder, and rapidly cooled at 25 ° C. or lower to form an annular parison. Thereafter, if necessary, preheating is performed, and thereafter, inflation is performed at a temperature of 30 to 120 ° C. to form a tubular wrap film. Thereafter, heat treatment is performed while relaxing at 80 to 200 ° C. Next, a raw wrap film is obtained while peeling it into a single film while winding and slitting. However, the step of peeling into one sheet may be performed after winding two sheets of raw material.
Finally, the raw wrap film is rewound to a predetermined width and length to obtain a wrap film. When the compound of the present invention is applied, it may be applied in any step after the formation of the cyclic parison.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to only these examples. In the examples, the following measurement methods were used. Note that m and n in Examples and Comparative Examples respectively indicate m and n in the above formula (3). (1) Evaluation of firmness and stiffness Twenty skilled panelists were prepared and the diameter of the opening was 1
Using a wrap film of 30 cm in length and 30 cm in width in a 5 cm glass container, evaluation was performed in the following manner, taking into account the usability when covering the container. Evaluation symbol Description ◎: Extremely good firmness and stiffness, and extremely easy to handle. ；: Excellent firmness and stiffness, and no problem in handling. ×: Poor stiffness and stiffness. (2) Measurement method of tensile elastic modulus It was determined in accordance with ASTM-D882 (apparent elastic modulus at 2% elongation). The average value of the values in the machine direction (MD) and in the transverse direction (TD) of the wrap film was used.

(3) Evaluation of Odor Barrier Property Sardine, lemon, curry roux, and pickled pickles are placed in separate containers in a glass container having a diameter of 6 cm in the opening, and each opening is sealed with a wrap film, and a lid is provided. Inner volume 6
It was put into a 1-liter stainless steel container, stored in a refrigerator (5 ° C. in the refrigerator) for 3 days, taken out, and the odor in the stainless steel container was evaluated by sensory evaluation. The evaluation was performed by 10 panelists. The sensory test was evaluated in six steps in the following manner. Odor intensity Contents 0 Odorless 1 Smell barely detectable 2 Smell weak enough to tell what kind of smell 3 Easy smell 4 Easy smell 4 Strong smell 5 Particularly strong smell Then, evaluation was made in three stages of ◎, ○, and × as follows. Evaluation symbol Odor intensity average value Contents ◎ Less than 2 Very good barrier property ○ 2 or more and less than 3 Having barrier properties that can withstand practical use × 3 or more Insufficient barrier properties

(4) Evaluation of Practical Adhesion The film was tensioned and fixed to one of the bottom surfaces of two cylinders each having a bottom area of 25 cm ² so that no wrinkles were formed. The bottom surfaces of the two cylinders were overlapped, and pressed under a load of 500 g for 1 minute. Then, the films were peeled off in a direction perpendicular to the surfaces, and the energy required at that time was measured. Using this energy value, evaluation was made in three stages of ◎, 、, and × in the following manner.
The appropriate value for practical adhesion is 8 g · cm or more. Evaluation symbol Energy (unit: g · cm) Contents ◎ 12 or more Excellent in practical adhesion ○ 8 or more and less than 12 Practical adhesion × Less than 8 No practical adhesion (5) Practical heat resistance Width 30 mm, length 140 mm Paper is placed on the upper and lower sides of the strip-shaped film sample 25 mm and the weight of 10 g is lowered. The film was hung for one hour in an air oven adjusted to a constant temperature, and the maximum ambient temperature at which the film did not break was measured at intervals of 5 ° C. Using this maximum ambient temperature, evaluation was performed in the following manner. The higher the temperature, the better the practical heat resistance. Evaluation symbol Maximum ambient temperature Content ◎ 150 ° C or higher Very excellent in practical heat resistance ○ 130 ° C or more and less than 150 ° C Excellent in practical heat resistance × Less than 130 ° C Poor in practical heat resistance (6) Comprehensive evaluation The overall evaluation was performed as follows.

[0030]

Examples 1 to 5 and Comparative Examples 1 and 2 Each polytrimethylene terephthalate resin used in Examples 1 and 2 and Comparative Example 1 was obtained by the following method. From a predetermined amount of dimethyl terephthalate, 1,3-propanediol (provided that a hindered phenol-based antioxidant (AO-60 manufactured by Asahi Denka Kogyo KK) is used as an antioxidant), the intrinsic viscosity is 0.9.
Of polytritetramethylene terephthalate resin was obtained. The polytetramethylene resin used in Example 3 was obtained by the following method. Predetermined amount of dimethyl terephthalate, 1,3
-Propanediol, tetraethylene glycol (m =
1, n = 4) (However, a hindered phenolic antioxidant (AO-6 manufactured by Asahi Denka Kogyo KK) is used as an antioxidant.
0) is used, the intrinsic viscosity is 0.9, and the composition ratio is 1,3.
78 propanediol in 100 moles of total diol component
Thus, a polytrimethylene terephthalate-based resin was obtained in which the moles of tetraethylene glycol were 22 moles per 100 moles of the total diol.

The polytrimethylene terephthalate resin used in Examples 4 and 5 was obtained by the following method. A predetermined amount of dimethyl terephthalate, 1,3-propanediol, triethylene glycol (m = 1, n = 3), polytetramethylene glycol having a number average molecular weight of about 1000 (m =
2), (in which hindered phenolic antioxidant (AO-60 manufactured by Asahi Denka Kogyo KK) is used as an antioxidant), the intrinsic viscosity is 0.9, and the composition ratio of 1,3-propanediol is represented by the formula ( 80 moles per 100 moles of all diol components excluding the compound of m = 2 in 3), and 20 moles of triethylene glycol in 100 moles of all diol components excluding the compound of m = 2 in the formula (3), number average Molecular weight about 100
Thus, a polytrimethylene terephthalate-based resin was obtained in which the polytetramethylene glycol of No. 0 was 2.1 mol per 100 mol of the total acid component.

A predetermined additive was added to each of the obtained polytrimethylene terephthalate-based resins, and the mixture was kneaded and extruded to obtain chips of each resin composition. After drying, the sheet was extruded from a T-die, quenched into a sheet, and stretched by appropriately selecting a stretching ratio so that the average thickness of the raw wrap film was 10 μm. Furthermore, heat treatment is performed at 150 ° C., and the average thickness is 10
A wrapped film of μ was obtained. The raw wrap film was slit to obtain a wrap film having a width of 30 cm. In Example 1, after polymerization, 8 parts by weight of sorbitan laurate was added to the obtained polytrimethylene terephthalate-based resin.
Are wrap films obtained by adding 2 parts by weight of a polyterpene resin having a softening point of 100 ° C. (± 5 ° C.), kneading and extruding, and forming a film. On the other hand, Comparative Example 1 is a wrap film obtained by forming a film without adding an additive after polymerization.

The film was formed under the respective conditions shown in Table 1, and the obtained wrap film had firmness, firmness, tensile modulus, odor barrier property,
The practical adhesion, practical heat resistance, and the results of comprehensive evaluation of them are shown. As shown in Table 1, Examples 1 and 2
The firmness, firmness, tensile modulus, odor barrier property, practical adhesiveness, and practical heat resistance were all good, and were sufficiently satisfactory in performance as a wrap film. On the other hand, Comparative Example 1 was firm,
Although the stiffness, practical adhesion, and practical heat resistance are good, a wrap film having very poor practical adhesion was obtained because it did not contain the specific chemical substance described in claim 1 of the present invention. .

Comparative Example 2 contains 8 parts by weight of sorbitan laurate and has a density of 0.920 g obtained by stretching.
The evaluation results of a single-layer linear low-density polyethylene wrap film having a thickness of / cm ³ were shown. As shown in Table 1, the feeling of stiffness, odor barrier property, practical heat resistance and the like are extremely poor, and it is understood that it is necessary to use a polytetramethylene terephthalate resin as the resin. Example 3 is a wrap film obtained by polymerization using tetraethylene glycol in addition to 1,3-propanediol as the diol component at the time of polymerization.
Example 4 is an example in which triethylene glycol and polytetramethylene glycol were used in addition to 1,3-propanediol as the diol component at the time of polymerization. In each case, the feeling of stiffness and odor barrier properties were excellent, and the flexibility was improved. In Example 5, when the wrap film of Example 4 was formed, the stretching ratio was controlled to make the tensile elastic modulus 6000 kg / cm.
^This is an example in which a wrap film of No. ² was obtained. The wrap film was excellent in all evaluation items.

[0035]

[Table 1]

[0036]

According to the present invention, it is possible to provide a wrap film made of a polytrimethylene terephthalate resin having high practical heat resistance and having excellent practical adhesiveness, stiffness and odor barrier properties. .

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 93:00)

Claims (3)

[Claims] 1. A polytrimethylene terephthalate resin mainly containing a dicarboxylic acid component containing terephthalic acid as a main component and 1,3-propanediol as a diol component, and represented by the following formulas (1) and (2). The compound shown,
A wrap film comprising 1 to 10% by weight of at least one compound selected from the group consisting of sorbitan fatty acid esters having 8 to 22 carbon atoms of fatty acids, rosin esters, and polyterpene resins. Embedded image 2. The wrap film according to claim 1, wherein one or more diols represented by the following formula (3) are contained in a part of the diol component. Embedded image 3. A tensile wrap film according to claim 1 or 2, wherein the elastic modulus is 3000 kg / cm ² or more 15,000 kg / cm ² or less.