JPH11115130A - Laminated lap film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To incorporate a high practical use heat resistance, excellent practical use adhesive properties, tension, a sense of drape or odor barrier properties by laminating a layer made of a specific poly(trimethylene terephthalate) resin and a layer made of a polyolefin resin, and incorporating a specific compound. SOLUTION: This laminated lap film comprises a layer made of a polytrimethylene terephthalate resin containing a dicarboxylic acid component which contains a telephthalic acid as a main component and mainly containing 1,3-propanediol as a diol component, and a layer made of a polyolefin resin of at least two layers. The lam film comprises 1 to 10 wt.% of one or more types of compound selected from the group consisting of a compound represented by the formula (wherein, (l) is an integer of 0 to 3, and R is an alkyl residue of 8-22C saturated or unsaturated fatty acid), sorbitan (8-11C) fatty acid ester, rosin ester and polyterpene resin in view of practical adhesive properties, tension or flexibility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated wrap film used for directly wrapping food or food itself in a container such as a dish at home, and more particularly, a polytrimethylene terephthalate resin layer. And a laminated wrap film comprising a polyolefin resin layer.

[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 used to avoid dust on tableware and food placed on a table, and in a refrigerator, wrap film is placed on a container containing food and the smell of the food is reduced. In order to prevent the transfer to the food, the food has been used to keep the freshness of the food in the container. 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, but if the wrap film has a firmness and firmness, it is very easy to wrap the container or cover the container. it can. Further, in the above-mentioned usage form, 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, polyester-based films have been conventionally known as films having heat resistance. Among them, polytrimethylene terephthalate (polypropylene terephthalate) is more flexible than polyethylene terephthalate, as disclosed in JP-A-8-325391, and its feasibility as a packaging film for industrial parts is examined. It has been. However, since the wrap film does not have an adhesive property, it has hardly been studied as a wrap film, and it is far from practical use. Furthermore, as is sometimes seen with conventional wrap products, when removing the wrap film from the storage box, it may be difficult to remove it.In extreme cases, the wrap film of the required area cannot be taken out, The film was sometimes torn. Therefore, a wrap film that can be easily taken out of a box has been demanded.

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a wrap film having high practical heat resistance, excellent practical adhesiveness, a feeling of stiffness, odor barrier property and easy removal from a box. As an issue.

[0006]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems, and as a result, has high heat resistance, excellent adhesiveness, a feeling of crispness, odor barrier property and easy removal from the box. The present inventors have found a laminated wrap film having both properties and have accomplished the present invention. That is, the present invention provides a layer comprising a polytrimethylene terephthalate-based resin mainly containing a dicarboxylic acid component containing terephthalic acid as a main component and 1,3-propanediol as a diol component.
A laminated wrap film formed by laminating a layer comprising a polyolefin resin, a compound represented by the following formulas (1) and (2), a sorbitan fatty acid ester having a fatty acid having 8 to 22 carbon atoms, a rosin ester, and a polyterpene. A laminated wrap film comprising 1 to 10% by weight of one or more compounds selected from the group consisting of resins.

[0007]

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Hereinafter, the present invention will be described in detail. The present invention is different from the prior art in that a layer made of a specific polytrimethylene terephthalate-based resin and a layer made of a polyolefin resin are laminated, and that a specific compound is contained. 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), (I)
II) 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, a layer made of a specific polytrimethylene terephthalate resin and a layer made of a polyolefin resin are laminated, and a laminated wrap film containing 1 to 10% by weight of a specific compound. According to this, it has been found that a wrap film having both practical heat resistance, practical adhesion, odor barrier properties and easy removal from a storage box can be provided without impairing the feeling of stiffness.

In the conventional wrap film, there is a low correlation coefficient between the practical adhesiveness and the performance of taking out from the storage box, but there is a rough negative correlation. That is, when the practical adhesiveness is improved, the takeout performance tends to deteriorate. However, in the present invention, by adopting a configuration containing a layer made of a polytrimethylene terephthalate-based resin and a layer made of a polyolefin-based resin, easy take-out is enabled without impairing practical adhesion. Wrap film is usually 10
It is provided to general consumers in a state of being wound m to 100 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. Causes of poor take-out properties include tightness in the wound state and excessive close contact between the wrap films. For the former, 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) or a single-layer polyethylene wrap film.

The polytrimethylene terephthalate resin used in the present invention mainly comprises 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 is preferably 0.6 to 1.5 from the viewpoint of film formability and stretchability. The intrinsic viscosity is determined by using a solvent in which the polytrimethylene terephthalate resin is soluble.
It is a value measured at 25 ± 0.5 ° C. using a capillary solution viscometer with a solution concentration of 0.5 g / dL.
As a solvent, for example, in the case of a homopolymer, a 1: 1 mixture of methylene chloride and trifluoroacetic acid is used, and in the case of a copolymer, a 1: 1 mixture of methylene chloride and trifluoroacetic acid, and ethane tetrachloride. And phenol 1:
Either of the mixed solution of 1 and 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 of a diol component represented by the following formula (3) may be used in addition to 1,3-propanediol as a diol component. The above diol may be contained.

[0013]

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Here, when odor barrier properties are particularly required, when the diol having m = 2 is not used, 1,3
55% propanediol in 100 moles of total diol component
The diol having a mole of at least 79 moles and m = 1 may be used in an amount of 21 to 45 moles per 100 moles of all diol components. More preferably, the diol having 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 used from the viewpoints of odor barrier property, firmness, firmness and practical heat resistance. It may be preferable that 1,3-propanediol is 55 mol or more and 85 mol or less, and the diol with m = 1 is 15 mol or more and 45 mol or less in 100 mol of all diol components excluding the above.

When the diol with m = 2 is 0.2 mol or more and 3 mol or less with respect to 100 mol of all acid components, the diol with 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.

The polytrimethylene terephthalate resin used in the present invention includes polyethylene glycol, neopentyl glycol, 1,5-pentadiol and 1,6-hexanediol having a molecular weight of 238 or more within the scope of the present invention. The laminated film of the present invention needs to include a layer made of the above-mentioned polytrimethylene terephthalate-based resin and a layer made of a polyolefin-based resin from the viewpoint of practical adhesion and easy removal.

The polyolefin resin used in the present invention is an ultra-low-density linear polyethylene which is a copolymer of ethylene and one or more α-olefins selected from 1-butene, 1-hexene, 1-octene and the like. (Density: 0.870
0.910 g / cm ³ , MI: 0.1 to 10 g / 10
min. ), Ethylene and 1-butene, 1-hexene, 1
-A linear low-density polyethylene which is a copolymer with one or more α-olefins selected from octene and the like (density: 0.
910 to 0.929 g / cm ³ , MI (190 ° C., load 2.16 kg): 0.1 to 10 g / 10 min. ), High-pressure method low-density polyethylene (density: 0.910 to 0.92)
9g / cm ³ ), medium density polyethylene (density: 0.93
0 to 0.941 g / cm ³ , MI (190 ° C., load 2.
16 kg): 0.1 to 5 g / 10 min. ), High-density polyethylene (density: 0.942 to 0.960 g / c)
m ³ , MI (190 ° C., load 2.16 kg): 0.01
~ 5g / 10min. ), Polypropylene (MFI (2
30 ° C., load 2.16 kg): 0.5 to 40 g / 10 m
in. , Density 0.89-0.92 g / cm ³ ), poly 4
-Methylpentene-1 and the like. These resins may be used alone to form a polyolefin resin layer.
You may mix and use more than one kind.

In particular, when transparency and practical heat resistance are required, a polypropylene resin or a resin having a density of 0.
In some cases, it is preferable to use a crosslinked polyethylene resin having a weight of 87 to 0.929 g / cm ³ . When using a polypropylene resin: MFI (230 ° C., load 2.16 kg): 0.5 to 30 g / 10 min. And a density of 0.89 to 0.92 g / cm ³ is more preferable. Further, as the polypropylene resin, there are isotactic polypropylene, syndiotactic polypropylene, attack polypropylene and the like in terms of molecular structure, but a polypropylene resin containing more isotactic polypropylene portions is more preferable. The polypropylene resin used in the present invention may be a homopolymer or may be copolymerized with ethylene and 1-butene. Examples of the copolymer include a block copolymer and a random copolymer, and the use of a random copolymer is sometimes easier to produce than a laminate wrap film.

When a crosslinked polyethylene resin having a density of 0.87 to 0.929 g / cm ³ is used, a density of 0.900 to 0.10 is preferred from the viewpoint of practical adhesion and practical heat resistance.
In some cases, a 929 g / cm ³ polyethylene resin is more preferable. Further, in terms of structure, linear low-density polyethylene, which is a copolymer of ethylene and one or more α-olefins selected from 1-butene, 1-hexene, 1-octene, etc., maintains the strength of the laminated wrap film. May be preferred. However, high-pressure low-density polyethylene may be contained to supplement the moldability. The presence or absence of cross-linking is represented by a gel fraction, and the gel fraction may preferably be 5 to 65% by weight. Further, when it is desired to impart practical heat resistance, the gel fraction may be preferably 10 to 50% by weight.

In the laminated film of the present invention, practical adhesion,
From the viewpoint of firmness and firmness, it is essential to include a compound having a specific structure. That is, it is necessary to contain at least one compound selected from the group consisting of the compounds represented by the formulas (1) and (2), sorbitan fatty acid esters having 8 to 22 carbon atoms of fatty acids, rosin esters, and polyterpene resins. It is. The compounds represented by the general formulas (1) and (2) and the fatty acid component constituting the sorbitan fatty acid ester have 8 to 22 carbon atoms, and preferably 8 to 18 carbon atoms.
Further, the number of 1 (L) in the general formula (1) 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,
Esters of fatty acids selected from myristic acid, pentadecylic acid, stearic acid, nonadecanoic acid, oleic acid, linoleic acid, and linolenic acid are preferred.

The compound represented by the general formula (2) includes
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.

The 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.

When a rosin ester is used, examples thereof include, but are not limited to, methyl ester rosin,
Examples include hydrogenated methyl ester rosin, glycerin ester rosin, hydrogenated glycerin ester rosin, perhydrogenated glycerin ester rosin, pentaerythritol rosin, hydrogenated pentaerythritol rosin, perhydrogenated 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. The content of the compound is 1 to
It is essential that the content be 10% by weight, but when adhesion is particularly required, it may be preferable to add 2 to 8% by weight. If the content is less than 1% by weight, the adhesion may not be sufficient. If the content exceeds 10% by weight, a large amount is present on the surface of the wrap film, and when used, a sticky feeling is felt, which is not preferable as a wrap film.

In the laminated film of the present invention, the above compound may be contained in the polytetramethylene resin layer of the present invention to form a film, or may be contained in the polyolefin resin layer to form a film. It may be contained in a layer. Furthermore, it may be more preferable to include the polytetramethylene resin layer alone. It may be applied during or after the production of the laminated wrap film. In the wrap film of the present invention, in addition to the above compounds, additives such as a plasticizer, an antioxidant, a lubricant, an antiblocking agent, and a crystallization aid may be contained as long as the purpose of the wrap film is not impaired. .

When a plasticizer is used to further impart flexibility, for example, a phthalate plasticizer (for example, dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate, etc.), an aliphatic dibasic ester plasticizer, etc. Agents (for example, dibutyl sebacate, di-2-ethylhexyl adipate, di-ethylhexyl azelate, etc.) and phosphate plasticizer (for example, diphenyl 2-ethylhexyl phosphate, etc.) in the range of 2 to 7% by weight. May be contained. The plasticizer can be used alone or as a mixture of several types.

When an antioxidant is used, hindered phenols (for example, pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]) are exemplified. ), Thiopropionate, fatty acid sulfide, phosphite, thiophosphite and the like.
It may be contained alone or in a mixture of several kinds in the range of -3000 ppm.

Lubricants (eg, calcium stearate,
When using magnesium stearate, stearic acid, liquid paraffin, butyl stearate, monoglyceride stearate, etc. as examples)
You may make it contain in the range of 300 ppm. 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 3.6 μm, and further 1.0
~ 2.0 microns may be more preferred, these are examples)
m may be contained. Furthermore, 5-250pp
In some cases, m is more preferable. When a crystallization aid (for example, sorbitol-based nucleating agent (dibenzylidene sorbitol or the like), CaCO ₃ or the like is used as an example) for the polypropylene resin layer, 500 to 2000 pp
m may be contained.

The laminated wrap film of the present invention is a laminated film composed of at least two layers containing a layer composed of the polytrimethylene terephthalate resin and a layer composed of the polyolefin resin. The outermost layer to improve take-out
It may be preferable that a layer made of a polytrimethylene terephthalate resin or a layer made of a polyolefin resin is provided. If it is in normal storage condition, there is no problem, but after the product is manufactured, the season until the product is passed to the general consumer,
It may be stored at a very high temperature depending on the storage location. At this time, since the laminated wrap film of the present invention is provided with adhesiveness, when exposed to an extremely high temperature different from a normal storage state, the adhesiveness between the wrap films may be excessively adhered. . When excessive close contact occurs, there is a high possibility that the take-out property deteriorates. In order to prevent such a rare case, if a polyolefin-based resin layer is arranged on the outermost layer opposite to the outermost layer of the polytrimethylene terephthalate-based resin layer, it may be easier to take out the resin. In this case, the layer configuration of the laminated wrap film may be two to five layers. Increasing the number of layers beyond five increases the number of manufacturing conditions and complicates the manufacture of the laminated wrap film. More preferably, it has two or three layers. Furthermore, between the layer made of polytrimethylene terephthalate-based resin and the layer made of polyolefin-based resin, ethylene vinyl alcohol-based resin, low-density polyethylene-based resin, and ultra-low-density polyethylene-based resin are used to improve the adhesive strength between the layers. It is also preferable that a layer composed of at least one selected from a mixture of a polytrimethylene terephthalate-based resin and a polyolefin-based resin to be used, an ethylene-glycidyl methacrylate copolymer, and the like be disposed as an intermediate layer.

In some cases, the average thickness of the laminated wrap film of the present invention is preferably 2 μm or more and 50 μm or less. 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 it is less than 2 μm, it may be difficult to handle as a wrap film,
If it exceeds 50 μm, followability to the container shape is poor, and it may be difficult to cover the container.

The thickness ratio of the layers of the laminated wrap film of the present invention is not particularly limited, but it is preferable that 20 to 80% of the total thickness is a layer made of polytrimethylene terephthalate resin, and more preferably 20 to 60%. % Is preferably a layer made of a polytrimethylene terephthalate resin.
If it is less than 20%, the feeling of stiffness may be impaired, and if it exceeds 80%, it may be difficult to uniformly extrude the olefin layer and other layers when co-extrusion is carried out depending on the extruder.

The tensile modulus of the laminated wrap film of the present invention it may be preferably 3000 kg / cm ² or more 15,000 kg / cm ² or less. 3,000 kg
In some cases, it is more preferable that the concentration be not less than 1 kg / cm ^{2 and not} more than 10,000 kg / cm ² . Tensile modulus is 3000 kg / cm ²
If the tensile modulus is less than 15,000 kg / cm ² , packaging may be difficult depending on the container to be put on practically if the tensile modulus exceeds 15,000 kg / cm ² .

The laminated wrap film according to the present invention has an excellent odor barrier property against odors of foods and the like normally stored in a refrigerator such as sardine, lemon, curry roux, and pickled radish, as compared with, for example, commercially available single-layer polyethylene wraps. . Although there are various production methods for the production method of the laminated wrap film of the present invention, an example of a preferable production method will be described with respect to a sequential biaxial stretching method and an 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 above resin compositions or resins is dried, then melted at a temperature not lower than the melting point, and is extruded with a monoaxial or biaxial extruder to form a single-layer die (when each layer is bonded outside the die). ) Or from a multilayer die (in the case of coextrusion) in a molten state. The extruded molten resin is rapidly cooled and solidified by a casting drum. When using a single-layer die, before or after this step, if the surface is treated by corona discharge treatment, UV irradiation, ozone treatment, etc., the adhesive strength between the layers tends to increase, so one or more of these treatments must be performed. It may be preferable to do so. These treatments may be performed after stretching the wrap film. Also, after these optional surface treatments have been performed,
The next layer may be stacked. In the case of performing a cross-linking treatment, an electron beam is applied at 5 to 15 Mrad in this step, and an accelerating voltage is 175.
Irradiate at ~ 500 kV.

Next, the film is stretched in the machine direction at a temperature of 40 to 170 ° C. and a draw ratio of 1.1 to 5 times using a roll stretching machine. Next, after cooling and pre-heat treatment at 40 to 200 ° C., stretching is performed using a tenter in the transverse direction at a temperature of 40 to 170 ° C. and a stretching ratio of 2 to 10 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 multilayer annular die attached to the tip of the extruder, and rapidly cooled at 25 ° C. or lower to form an annular parison. When performing a cross-linking treatment, an electron beam is applied in this step at a rate of 5 to 15 Mrad and an acceleration voltage of 175 to 500
Irradiate at kV. Thereafter, if necessary, preheating is performed, and thereafter, inflation is performed at a temperature of 30 to 180 ° 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.

[0036]

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. Further, m and n in Examples and Comparative Examples each represent m and n in the above formula (3). In the examples, the following measurement methods were used. (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) Evaluation of odor barrier properties In a glass container having a diameter of 6 cm in the opening, put sardine, lemon, curry roux and pickled radish in separate containers, seal the opening with a wrap film for each sample, and fill the inner volume 6 with a lid.
It was put in 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 a sensory test. The evaluation was performed by 10 panelists. The sensory test was evaluated in the following manner in six steps. Odor intensity Content 0 Odorless 1 Smell that can be perceived at last 2 Smell that is weak enough to tell what kind of smell 3 Smell that can be easily perceived 4 Strong smell 5 Particularly strong smell Evaluation of the smell barrier property averages the smell intensity of each substance. The evaluation was made in three stages of の, 、 and × as follows. Evaluation symbol Odor intensity Content ◎ Less than 2 Very excellent barrier property ○ 2 or more and less than 3 Having barrier properties that can be put to practical use × 3 or more Insufficient barrier properties

(3) Evaluation of Practical Adhesion A film was fixed on one of the bottom surfaces of two cylinders each having a bottom area of 25 cm ² by tension 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) Content ◎ 12 or more, excellent in practical adhesion ○ 8 to less than 12, practical adhesion × less than 8, no practical adhesion (4) Practical heat resistance 30 mm width, 140 mm length 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 (5) Removal performance evaluation Box-type wrap film storage Each sample was stored in a box (for example, a wrap film storage box used in a 30 cm × 20 m household Saran wrap (Asahi Kasei Corporation, registered trademark) released in September 1997) and 20 skilled panelists Comprehensively check the ease of withdrawal when pulling out the wrap film about 30 cm from the storage box (do not try to jump out of the wrap film in a rolled state, resistance when pulling out), check that the wrap film is not cut or torn. Sensory evaluation was performed, and evaluation was performed in the following three stages. A: The wrap film can be taken out of the storage box very easily. : The wrap film is slightly harder to remove than the storage box. ×: The wrap film is difficult to remove from the storage box.

(6) Method of Measuring Gel Fraction The gel fraction referred to in the present invention refers to a gel fraction determined by the following operation in accordance with ASTM D2765. A sample obtained by sampling the polyethylene layer from a predetermined place is weighed (Sg) with a balance having an accuracy of 0.01 mg. Oil was removed by immersing in acetone for 24 hours beforehand15
The pouch of the SUS screen of 0 mesh and the sample are combined and weighed (W1 g) using the same balance as above. Wrap the sample in a pouch. The pouched sample is kept in a boiling para-xylene for 12 hours in an uncrosslinked polyethylene portion using a separable flask and a condenser. Thereafter, the uncrosslinked polytrimethylene terephthalate-based resin part is dissolved in a mixed solvent of equal weight of ethane tetrachloride / phenol. When another resin is used for a part of the laminated film, the resin is dissolved by using an appropriate solvent that can be appropriately dissolved. The sample wrapped in the pouch is dried by a vacuum drier to constant weight. The sample wrapped in the pouch is weighed with the same balance as above (W2g)
I do. Gel fraction (% by weight) = [1-((W1-W2) /
S)] The gel fraction is calculated using the formula of × 100. (7) Comprehensive evaluation Using the above evaluation, comprehensive evaluation was performed in the following manner.

[0039]

Examples 1 to 7 and Comparative Example 1 Each of the polytrimethylene terephthalate resins used in Examples 1, 4 and 5 was obtained by the following method. A predetermined amount of dimethyl terephthalate, 1,
3-propanediol, triethylene glycol (m =
1, n = 3) (However, a hindered phenol-based antioxidant (AO-6 manufactured by Asahi Denka Kogyo KK)
0)), an intrinsic viscosity of 0.9 and a composition ratio of 1,
3-propanediol is 80 moles in 100 moles of all diol components excluding the compound of m = 2 in the formula (3), and triethylene glycol is 100 moles of all diol components excluding the compound of m = 2 in the formula (3). 20 mol of polytritetramethylene terephthalate-based resin was obtained.

The polytrimethylene terephthalate resin used in Examples 2 and 6 was obtained by the following method. Terephthalic acid, 1,3-propanediol, triethylene glycol (m = 1, n = 3), polytetramethylene glycol (m = 2) having a number average molecular weight of about 1,000 (however, hindered phenol-based antioxidants From the antioxidant (AO-60 manufactured by Asahi Denka Kogyo Co., Ltd.), intrinsic viscosity of 0.9, and 1,3-propanediol as a composition ratio excluding the compound of m = 2 in the formula (3) All diol components 1
80 moles out of 00 moles, the total diol component 1 excluding the compound where m = 2 in the formula (3)
A polytrimethylene terephthalate-based resin was obtained in which 20 moles per 100 moles and polytetramethylene glycol having a number average molecular weight of about 1000 were 2.1 moles per 100 moles of all acid components.

Each of the polytrimethylene terephthalate resins used in Examples 3 and 7 was obtained by the following method. Intrinsic viscosity 0.9, composition from terephthalic acid, 1,3-propanediol, tetraethylene glycol (however, a hindered phenolic antioxidant (AO-60 manufactured by Asahi Denka Kogyo KK) is used as an antioxidant) In terms of ratio, 1,3-propanediol is 80 mol per 100 mol of all diol components excluding the compound of m = 2 in the formula (3), and tetraethylene glycol is excluding the compound of m = 2 in the formula (3). As a result, 20 moles of a polytrimethylene terephthalate-based resin in 100 moles of all diol components was obtained.

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 density is 0.89 g / cm in Examples 1, 2, 3, and 4 from the multilayer T-die.
³ , MI (190 ° C., load 2.16 kg): 4 g / 10
min. A resin composition of a mixture of polytrimethylene terephthalate resin and polypropylene resin (composition ratio (% by weight) = 50: 50) is coextruded into the polypropylene resin and the intermediate layer, and quenched to form a sheet. The stretching ratio was appropriately selected so that the average thickness of the film was 10 μm, and the film was stretched. Further heat treatment, average thickness 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 Examples 5, 6, and 7, the density was 0.91.
0 g / cm ³ , MFI (230 ° C., load 2.16 k
g): 4 g / 10 min. A resin composition of a mixture (composition ratio = 50: 50) of each polytrimethylene methylene terephthalate-based resin and ultra-low-density polyethylene-based resin is co-extruded on the ultra low density polyethylene resin and the intermediate layer, and quenched to form a sheet. After the linear cross-linking treatment, stretching was performed by appropriately selecting a stretching ratio so that the average thickness of the wrapped film was 10 μm. Further heat treatment was performed to obtain a raw wrap film having an average thickness of 10 μm. The raw wrap film was slit to obtain a wrap film having a width of 30 cm. Examples 5, 6 and 7
Was 20% by weight.

Examples 1, 2, 3, 5, 6, and 7 were obtained after polymerization.
8 parts by weight of sorbitan laurate was added to the obtained polytrimethylene terephthalate resin, and the softening point of Example 4 was 100 ° C.
A wrap film was obtained by adding 2 parts by weight of a polyterpene resin (± 5 ° C.), kneading and extruding, and forming a film.
Comparative Example 1 had a density of 0.910 g / cm ³ and an MI (190
° C, load 2.16 kg): 4 g / 10 min. Wrap film made of ultra low density polyethylene resin.
Table 1 shows the results of comprehensive evaluation of the wrap films obtained under the respective conditions and having a firmness, firmness, odor barrier property, practical adhesion, practical heat resistance, take-out performance, and the like.
In Examples 1, 3, 4, 5, and 7, a wrap film was produced using one kind of diol component in addition to 1,3-propanediol, and evaluated.

Examples 1, 4, and 5 are examples in which triethylene glycol is used as a diol component other than 1,3-propanediol. Examples 3 and 7 are examples in which tetraethylene glycol is used. A good overall evaluation was obtained as a film. Also, as shown in Examples 2 and 6, even when two or more diol components were used in addition to 1,3-propanediol, good overall evaluation as a wrap film was obtained. Examples 1 to 4 are examples in which a polypropylene resin is used as an olefin resin, and Examples 5 to 7 are examples in which a polyethylene resin is used. In all cases, good overall evaluation was obtained as a wrap film. Further, in Examples 5 to 7, crosslinking treatment was performed, but good overall evaluation was obtained. Example 4
Is an example using a polyterpene resin as a compound contained in the present invention. Even with this compound, a good overall evaluation was obtained.

As shown in Table 1, Examples 1 to 7 were all excellent in firmness, stiffness, odor barrier property, practical adhesion, practical heat resistance, and take-out performance, and were sufficiently satisfactory in performance as a wrap film. Met. On the other hand, Comparative Example 1 had good practical adhesion because the polytrimethylene terephthalate resin of the present invention was not laminated,
The wrap film was very poor in firmness, firmness, odor barrier property, practical heat resistance, and take-out performance.

[0047]

[Table 1]

[0048]

According to the present invention, a polytrimethylene terephthalate-based resin layer and a polyolefin resin layer having high practical heat resistance and having excellent practical adhesiveness, stiffness, odor barrier property and easy removal from a box. A laminated wrap film comprising:

Claims (5)

[Claims] 1. A layer comprising a polytrimethylene terephthalate resin mainly comprising terephthalic acid as a main component and 1,3-propanediol as a diol component, and a layer comprising a polyolefin resin. A laminated wrap film comprising at least two layers, selected from the group consisting of compounds represented by the following formulas (1) and (2), sorbitan fatty acid esters having 8 to 22 carbon atoms of fatty acids, rosin esters, and polyterpene resins. A laminated wrap film comprising 1 to 10% by weight of at least one compound. Embedded image 2. The laminated wrap film according to claim 1, wherein the polytrimethylene terephthalate resin is a polytrimethylene terephthalate resin containing at least one diol represented by the following formula (3) in a part of the diol component. . Embedded image 3. The laminated wrap film according to claim 1, wherein the main component of the polyolefin resin is a propylene resin. 4. The laminated wrap film according to claim 1, wherein a main component of the polyolefin resin is a crosslinked polyethylene resin having a density of 0.87 to 0.929 g / cm ³ . 5. One of the outermost layers is a layer made of a polytrimethylene terephthalate resin, and the other one of the outermost layers is a layer made of a polyolefin resin.
The laminated wrap film according to any one of claims 1 to 4, comprising 5 to 5 layers.