JPS5914948A - Filmy laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film-like laminate, and more specifically, a film-like laminate that has excellent heat-sealing properties, anti-blocking properties, and oil resistance, and can be easily opened when used as a lid material for a container. It is related to.

Plastic films, especially unstretched films or sheets of polyethylene terephthalate (hereinafter referred to as PET)
Films (hereinafter simply referred to as films) are widely used as packaging materials for foods, beverages, etc. because of their excellent transparency, safety and hygiene properties, and ease of thermoforming. For example, P.E.
Containers thermoformed from T-film have been widely used in recent years as containers for foods such as margarine or containers for beverages such as sake.

The lid of the Kowara container is made of PET film or aluminum foil coated with adhesive.
Usually, the lid material and the container body are bonded together by thermal bonding (hereinafter referred to as heat sealing).

Containers manufactured in this way require the lid to be removed when taking out the contents, but the lids of the containers currently on the market do not easily peel off from the tea utensils, so for example, if the lid is made of aluminum foil, the lid must be torn off. Furthermore, when using PET film, there is a drawback in that the contents must be removed by cutting off the lid with a cutter.

As a method to improve these drawbacks, improvements in the adhesive applied to the lid material have been widely studied, but none has been found to be satisfactory. For example, if the container body and lid material are easily peeled off (hereinafter referred to as "easy open"), the adhesion between the lid materials used for heat sealing (hereinafter referred to as "pup-seoking") may be too strong, causing problems in handling. In some cases, the heat-sealing conditions are too narrow and stable adhesion is difficult (hereinafter referred to as heat-sealability), and depending on the contents (especially oil-based contents), the adhesive strength may deteriorate due to penetration into the sealed area. They often have new drawbacks, such as a decrease in oil resistance (hereinafter referred to as oil resistance).

As a result of repeated studies on a lid material that has excellent heat-sealing properties, anti-blocking properties, anti-oil properties, and is easy to open, the inventor of the present invention has developed a lid material that has excellent heat-sealing properties, anti-blocking properties, anti-oil properties, and is easy to open. Kikiri discovered that a specific polyester resin containing a small proportion of polyester resin satisfies the above characteristics, and that a film-like laminate obtained by laminating this resin on a film-like material is particularly useful as a lid material. .

That is, the present invention is a polyester resin having an intrinsic viscosity of 0.5 or more and a softening point of 80 to 180°C, and an inorganic material having an average particle diameter of 20 μ or less in a weight ratio of 0.05 to 5 per polyester resin. This is a film-like laminate formed by laminating a thin layer of a composition in which particles are uniformly dispersed on at least one surface of a film-like material.

In the present invention, the thin layer of the composition laminated on at least one surface of the film material acts as a thermal adhesive, and in particular, the polyester resin constituting the composition primarily acts as an adhesive. This polyester resin is extremely Al! It has the characteristics of a viscosity of 0.5 or more and a softening point of 80 to 180°C, and is preferably terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, or diphenyl dicarboxylic acid.

Aromatic dicarboxylic acids such as diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, etc. and sulfone 1i2N as part of them.
Those into which a group has been introduced; alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, etc.: adibic acid.

Aliphatic dicarboxylic acids such as cepacic acid, azelaic acid, etc.: p-β-human p-oxyethoxybenzoic acid, one or more other difunctional carboxylic acids such as oxyacids such as ε-oxycuponic acid, etc. and ethylene glycol,
trimethylene glycol, tetramethylene glycol,
hexamethylene glycol, decamethylene glycol,
Neoventrene glycol, diethylene glycol, 1
．． of other glycols such as 1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, 2,2-bis(4'-β-hydroxyethoxyphenyl)propane, bis(4'-β-hydroxyethoxyphenyl)sulfonic acid. It is a copolyester consisting of one or more types.

If the intrinsic viscosity of this polyester resin is lower than 0.5,
For example, the adhesive strength with the container body during heat sealing becomes weak, which is not preferable.

Although there is no particular upper limit to the intrinsic viscosity, if it is too high, production becomes difficult, so it is preferable to take this point into consideration when determining the intrinsic viscosity of the polymer used. Also, if the softening point of the polyester resin is similar to 80"C, the blocking property will be poor, and if the softening point is higher than 180"C, the range of heat sealing will be narrow, and when applied to film-like materials.

It is not preferred because it is difficult to dissolve in a solvent during lamination.

In the present invention, the inorganic particles having an average particle diameter of 20μ or less that are uniformly dispersed in the polyester resin include, for example, 5t
o21 'rio,, CaCO3+ Fe2O3+
A12o,.

Examples include particles of CaO, MgOl$, and mixtures thereof. Among these, 5i02 particles are particularly preferred in terms of improving effects.

The mixing ratio of this inorganic particle is 0 per polyester resin.
．． 05-55-5% by weight or 0.1-2% by weight. If the average diameter of these inorganic particles is larger than 20μ,
This is not preferable because the adhesive strength becomes low. Further, if the mixing ratio is more than 5% by weight, the adhesive strength will be too weak, and if it is less than 0.055% by weight, the pushing property will not be improved, which is undesirable.

The polyester resin and the inorganic particles may be uniformly mixed by any method as long as they are mixed uniformly. For example, in a solvent such as toluene or methyl ethyl ketone,
A method of dissolving and dispersing both, a method of dispersing inorganic particles in a molten polyester resin, etc. are used.

In the present invention, the above-mentioned composition is laminated on at least one surface of a film-like object, and the method of lamination is, for example, after applying a composition dissolved and dispersed in a solvent to at least one surface of the film-like object. Examples include a method in which the solvent is removed by evaporation, a method in which a molten composition is applied and then cooled and assimilated, and a coextrusion method.

The thickness of the composition layer (adhesive layer) may normally be selected so that the adhesive strength is appropriate, but for example, the thickness is 50 μm or less, especially 10 μm or less.
Preferably around μ.

The film-like material on which the adhesive layer is laminated in the present invention may be of any material as long as it can be laminated, but for example, thermoplastic resin films such as polyester, and metal foils such as aluminum foil are preferably used. be done. In the case of polyester films, polyesters containing ethylene terephthalate (PET) as the main repeating unit are preferred;
Particularly preferred is a non-oriented film in which other polyesters such as polybutylene terephthalate and polyarylate are mixed within 30% by weight.

The preferred thickness of the film-like material varies depending on the material of which the film is made, but it should be such that the temperature of the sealing surface rises to a temperature that produces adhesive strength in a short period of time (for example, within 3 seconds) when heat sealing is performed. The thickness is preferably 300μ or less in the case of polyester film, and 100μ or less in the case of aluminum foil.

The polyester film is preferably a polyethylene terephthalate (Plj:T) film, and a part of the terephthalic acid component of the polyethylene terephthalate is, for example, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone di=
Aromatic dicarboxylic acids such as 9-carboxylic acids; alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahyto-isophthalic acid, etc.; adipic acid.

Aliphatic dicarboxylic acid M such as cepatic acid, azelaic acid, etc.
s p-β-human p-xyethoxybenzoic acid, ε-oxycaproic acid, etc. with one or more other bifunctional carboxylic acids such as oxyacids, and/or a portion of the ethylene glycol component may be substituted with e.g. trimethylene glycol. , tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene gellicol.

Diethylene glycol, 1.1-cyclohexane dimethylol, 1.4-cyclohexane dimethylol, 2.2
-bis(4'-β-hydroxyethoxyphenyl)propane, bis(4'-β-hydroxyethoxyphenyl)
A film of a copolymer copolymerized with one or more polyfunctional compounds of other glycols such as sulfonic acids and functional derivatives thereof, substituted within 15 molar units, preferably within 5 molar ranges. There may be.

-10- In addition, as polybutylene terephthalate, polybutylene terephthalate (polytetramethylene terephthalate-1,
) and modified polybutylene terephthalate can be used. Further examples of polyarylates include polyesters prepared from bisphenols, especially bisphenol AI' aromatic dicarboxylic acids, especially mixtures of terephthalic acid and isophthalic acid or their ester-forming derivatives. Commercially available products can be used as these.

The film-like laminate of the present invention thus obtained has heat-sealing properties and anti-blocking properties.

It has excellent oil resistance and can be used especially as a film for lids that can be opened easily.

The present invention will be explained in detail with reference to Examples below. The conditions for measuring the main characteristic values are as follows.

Ocular viscosity (rv): Measured at 35°C using o-chlorophenol as a solvent.

Softening point (sp): Based on Vicat softening point measurement method.

Easy openability: Lay the sample cut to 15 mm wide with the sample to be bonded so that the adhesive layer is in the middle, and
Heat sealing was performed at a predetermined hot water temperature and a predetermined pressure for a predetermined time using a heat solar having a heating part with a width of m1, and after the sealed part had cooled to room temperature, the adhesive strength was measured.

If the adhesive strength is 0.5 to 2.0 kg/l 5 and the seal temperature range is 20°C or more...extremely good 010 to 20
If the temperature is ℃...Good If the temperature is 05 to 10℃...
・Slightly poor △If below 5℃...Poor
It was set as ×.

Blocking resistance: unstretched PET film with a wall thickness of 125 It and a width of 50 mm with an adhesive layer applied on one side. ．． .

A sample with a length of 300 pieces was wrapped in about 7 rolls with a diameter of 6 to 10 sweetfish, the outside was fixed with a rubber band, and left at 20°C for 12 hours.

After standing still, the rubber band was removed and the condition was evaluated as follows.

Closely attached as rolled × (defective) Maki is released W, but once again It's all set (・.

When the roll is released and the film is re-wound and both ends are held down so that the ends are not aligned, the film contacts ◎ (extremely good) and the surface slides well and the ends are evenly aligned.

Oil resistance: Heat-sealed adhesive samples in the same way as for measuring easy-open properties were placed in cooking oil for 20 minutes.
After being immersed for one week at °C, the adhesive strength was measured and evaluated according to the following criteria.

Decrease rate of adhesive strength is 5 inches or less... ◎ Very good 5-10%... ○ Good 13- Decrease rate of adhesive force is 10-30%... △ Fairly good 30%-... X Bad Examples 1 to 8 and Comparative Examples 1 to 4 70 mol of terephthalic acid and 3 mol of sebacic acid as acid components
0 mole ratio, ethylene glycol as glycol component 5
30 parts by weight of a modified polyester (polyester adhesive -■) copolymerized with 5 molar polyester and neopentylene gellicol 457 mol at IV=0.70°5P123°C, 80 wt% toluene and 20 wt% methyl ethyl ketone. The mixture was dissolved in a mixed solvent, and the modifier shown in Table 1 was further added thereto. The obtained mixed solution was heated to a thickness of 125μ, r
v=o, 60, 5P=255°C non-oriented transparent PET
After applying the film to a thickness of about 10μ on one side,
The solvent was removed by evaporation at °C to obtain a laminated PET film coated with an adhesive layer on one side.

This laminated PET film was cut into 1511 widths 14
- Thickness: 600μ, 1iil! Bl and a non-oriented transparent PET sheet were heat-sealed using a heat-sealer having a heating part with a width of 5'' while changing the heating temperature from 160°C to 230°C in 5°C increments. The heat sealing time was about 1 second. The sample thus obtained was evaluated by the method described above. Evaluation results
Shown in 1.

In addition, in place of the above polyester adhesive -■, 55 mol of inphthalic acid and 45 mol of TV phthalic acid were used as acid components, and 55 mol of neopentylene gellicol and 457 mol of ethylene glycol were copolymerized as glycol components. 0.55.

The same test as above was carried out except that modified polyester (polyester adhesive -■) of 5P=165°C was used. The results are shown in Table-1.

Example-9 and Comparative Example-6 The same procedure as Example-1 and Comparative Example-3 was carried out, except that aluminum foil with a thickness of 40 μm was used instead of the non-oriented transparent polyester film with a thickness of 125 μm, and further evaluation was performed. did. The obtained results were similar to those in Example-1 and Comparative Example-3.

As is clear from the above examples, the film-like mound layer of the present invention has good heat-sealing properties, oil resistance, and boot-king properties, and is excellent as a lid material that can be opened easily.

17-

Claims (1)

[Claims] 1. Intrinsic viscosity is 0.5 or more, and softening point is 80 to 18.
A thin layer of a composition in which inorganic particles with an average particle diameter of 20 μm or less are uniformly dispersed in a polyester resin at a temperature of 0°C at a ratio of 0.05 to 5% by weight per polyester resin is laminated on at least one surface of the film-like object. A film-like laminate. 2. The laminate according to claim 1, wherein the inorganic particles are particles containing 8402 as a main component. 3. The film-like material has an intrinsic viscosity of 0.5 to 1. Softening point 20
2. The laminate according to claim 1, which is a substantially non-oriented film made mainly of polyester whose main repeating unit is ethylene terephthalate at 0° C. or higher, or an aluminum foil. 4. The substantially undistributed film has an intrinsic viscosity of 0.5 to 1.
Claims characterized by a film comprising a composition comprising a polyester having a softening point of 200° C. or more as a main repeating unit of ethylene terephthalate and polybutylene terephthalate of 30 weight fil % or less per polyester. The laminate according to item 3.