JPS6317048A - 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 [Field of Industrial Application] The present invention relates to a film-like laminate, and more specifically, when used as a lid material for heat bonding of polycarbonate or polyester containers, it has excellent heat bondability (heat sealability). The present invention relates to a film-like laminate having good properties (also referred to as compatibility) and excellent unsealability (also referred to as easy-opening).

[Prior art]

Thermoforming (injection molding) sheets made of polycarbonate or polyester (especially polyethylene terephthalate)
The tray-shaped or cup-shaped molded articles obtained by this process are widely used as food or beverage containers. The polycarbonate tray-shaped container is particularly heat resistant as a curry container.

It has excellent properties such as koto resistance, impact resistance, incense retention, and insect repellency. For example, in the case of a polycarbonate tray, a polycarbonate film thermally bonded is used as the lid material for such a container.

However, when such a lid material is thermally bonded, the heat sealing temperature is high, so the sealing part of the lid material or tray becomes thin or partially thermally deteriorated.
There are drawbacks such as the sealing part becoming brittle or partially broken. Furthermore, when taking out the contents from the container, since the lid material is more difficult to peel than the tray, it is necessary to cut open the lid material, which is inconvenient.

[Purpose of the invention]

In order to improve these drawbacks, the present inventor has conducted intensive research into a lid material with excellent heat-sealing properties and easy-open properties, and has found that the material is made of a composition in which a specific polyester and a specific polyolefin are mixed in a specific ratio. The inventors have discovered that a laminate in which a thin layer is laminated on at least the surface of a specific film-like material is useful as a lidding material, and has thus arrived at the present invention.

[Structure of the invention]

That is, the present invention comprises 1 oozz part of a thermoplastic polyester having a melting point of 80 to 200°C and 1 to 10 oz of a polyolefin resin.
This is a film-like laminate in which a thin layer made of a composition melt-mixed with 0 parts by weight is laminated on at least one side of a film-like material.

The embodiment is as follows. The thermoplastic polyester contains terephthalic acid and/or in7 as its acid component.
A glycol containing at least 50 mol% of tar acid and whose glycol component is selected from ethylene glycol, neopentylene gellicol, tetramethylene glycol, diethylene glycol and cyclohexalinemethanol.
Thin layers of co-electrical composites containing at least 50 mole percent of the species or species are preferred. Further, as for the composition, it is preferable to use low density polyethylene as the polyolefin resin in the thermoplastic polynisder.

Furthermore, the film-like material is suitably an unstretched film or a film stretched at least in the l-axis direction, the main component of which is polyester resin, polycarbonate resin, or a mixture thereof.

The present invention will be further explained.

The thermoplastic polyester used in the present invention has a melting point of 80
℃ to 200℃, but if the melting point is higher than 200℃, it may be difficult to laminate with a film-like material, or the heat sealing temperature may be too high, resulting in deformation or embrittlement of the container seal. It becomes noticeable and undesirable. Moreover, if the melting point is lower than 80° C., the lid material will peel off from the main body when the contents are heat sterilized after sealing, which is not preferable.

The polyester of the present invention includes terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenylsulfone dicarboxylic acid as acid components.

Aromatic dicarboxylic acids such as alkali metal sulfoisophthalic acid salts; hexahydroterephthalic acid.

Alicyclic dicarboxylic acids such as hexahydroinphthalic acid; aliphatic dicarboxylic acids such as adipic acid, sepatic acid, azelaic acid, etc.; p-β-human mixyethoxybenzoic acid, p-oxybenzoic acid, C-oxycaprone Components of l'm or more of other difunctional carboxylic acids such as oxyacids such as acids, etc., and ethylene glycol as a glycol component.

trimethylene glycol, tetramethylene glycol,
hexamethylene glycol, decamethylene glycol,
Neopentyrene gellicol.

Diethylene glycol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, 2
．． 2-bis(4-β-hydroxyethoxyphenyl)furopane, bis(4-β-hydroxyethoxyphenyl)
It is a polyester (a copolymer thereof) obtained by polymerizing one or more components of other glycols such as sulfone.

In particular, it is preferable that terephthalic acid and/or inphthalic acid be present in an amount of 50 mol % or more as an acid component, since the adhesive layer will have appropriate rigidity.

In addition, glycol components include ethylene glycol, neopentylene glycol, tetramethylene glycol,
It is preferable that the content of the component selected from diethylene glycol, cyclohexaline methanol, and bisphenol A is 50 mol % or more because adhesive strength will be moderate.

In particular, polyester having a glass transition temperature lower than 50° C. is preferable because easy-opening property becomes good when mixed with a polyolefin resin.

In the present invention, a thin layer of a composition obtained by melt-mixing thermoplastic polyester 1001 [100 parts by weight of polyolefin resin F&l to 100 parts by weight with respect to the mounting part] is laminated on a film-like material, and this mixing ratio is determined to be suitable for thermal adhesion with the container body. Strength is 0.5
~2.01qF715m, and its proportions can be selected appropriately depending on the copolymer composition and proportion of the polyester used, as well as the degree of polymerization, degree of polymerization, and degree of orientation of the polymer constituting the container body. However, if the proportion of the polyolefin resin is lower than 1%, it is not preferable because the adhesive strength is difficult to easily open and the adhesive surface is likely to be cut when the lid material is peeled off. Furthermore, if the mixing ratio of polyolef ink (fat) exceeds 100!m parts, fibrillation becomes noticeable and adhesive strength becomes weak.

Examples of polyolefin resins used in the present invention include general-purpose low-density polyethylene (LDPE), M-shaped low-density polyethylene (LLDPE), and high-density polyethylene (1IDPE).
, polypropylene (PP).

Examples include 4-methylpentene-1, ionomer, ethylene-vinyl acetate co-monomer (g'/A), and ethylene-ethyl flurylate co-monomer (EEA), among which low-density polyethylene is particularly preferred.

There is no particular restriction on the intrinsic viscosity of the thermoplastic polyester resin as long as the adhesive strength is moderate, but if it is lower than 0.4, for example, the stiffness of the thin layer itself bonded when the lid material is peeled off becomes weak,
Undesirable.

There is no particular upper limit for the intrinsic viscosity, but if it is too high, manufacturing will be difficult! liK, so it is preferable to determine the intrinsic viscosity of the polymer used in consideration of this point.1 In the present invention, the above-mentioned composition is laminated on at least one surface of a film-like object. A method in which a composition dissolved or dispersed in a tumor agent is applied to at least one side of the object, and then the solvent is evaporated off. A method in which the molten composition is extruded onto a # layer and cooled and solidified while being compressed in a cool environment. , coextrusion method, etc. are exemplified.

The thickness of the thin layer made of the composition may be selected so that the AM adhesive strength is appropriate, but for example, it is 50μ or less, particularly 30μ.
Preferably before and after.

The film-like material used in the present invention may be made of any material as long as it can be laminated; for example, a thermoplastic resin film such as polycarbonate or polyester,
Metallic foils such as aluminum foils are preferably used.

In particular, films made of biaxially stretched polyethylene terephthalate and further heat-set, polycarbonate films,
The poly7-relate film and the like have good adhesion when laminated with the thermoplastic polyester composition, and have a 10%
It is preferable because it has good dimensional stability during heat sterilization at 0 to 140°C.

Also, in the case of polyethylene terephthalate film, polybutylene terephthalate is added to this.

A non-oriented film in which other types of polyester such as poly7 rylate or polycarbonate are mixed in a weight range of 30% or less is also acceptable.

The preferred thickness of the film-like material differs depending on the material that makes up the film, but it should be such that the temperature of the trap sealing surface rises to a temperature that produces adhesive strength in a short period of time (for example, within 3 seconds) when heat-sealing. Preferably, for example, 3 in the case of polycarbonate film or polyester film.
It is preferably 00μ or less, and in the case of aluminum foil, 100μ or less.

In addition, in order to improve the heat seal strength and blocking property, for example, inorganic particles with an average particle diameter of 20 μ or less, such as St, , TtO,, CaC0,* F@, O, *
Particles such as A110g + ChO + Mg 2 O and mixtures thereof may be dispersed in thermoplastic polyester or polyolefin resin (or a stabilizer may be included to improve melt stability).

〔Effect of the invention〕

The film-like laminate of the present invention thus obtained has excellent heat-sealability, retort resistance, oil resistance, etc., and can be used particularly as a sheet or film for lid materials that can be easily opened for polycarbonate containers. .

〔Example〕

The present invention will be explained in detail with reference to Examples below.

The measurement conditions for the main physical property values are as follows.

+1) [j Viscosity (IV); Measured at 35°C in 0-chlorophenol or phenol/tetracoolethane mixed solvent.

(2) Density [ρ]: Measured at 25°C using a density gradient tube made of carbon tetrachloride and n-hebutane.

(3) Softening point (SP): Based on the Vicat softening point measurement method.

(4) Easy openability: A sample cut into 15 cm width is placed together with the sample to be bonded so that the adhesive layer is in the middle, and heated at a predetermined temperature and pressure for a predetermined time using a heat sealer with a heating part of 5 cm width. After sealing and cooling the sealed portion to room temperature, the adhesive strength was measured.

The adhesive strength was evaluated as follows.

Strength 1.0~3.0 kg/15 tm... Good 00.5~1.0...Slightly poor △0~
0.5# ... Defective × (5) Melting point (Tm): 20°C, /yax by differential calorimeter (DSC-20 model, manufactured by Seiko Electronics Co., Ltd.)
Measured at a heating rate of .

When a melting point peak did not appear on DSC, measurement was performed using a micro melting point measuring device (MPm manufactured by Yanagimoto Seisakusho).

(6) Glass transition temperature (:Tg) *Same as melting point DS
It was measured by C.

Examples 1 to 9 and Comparative Examples 1 to 9 (Molding of laminate) Thermoplastic polyester having the composition ratio shown in Table 1 (melt viscosity measured at 200°C with a Koka type flow tester is 50
The above-mentioned polyester) and polyolefin resin were blended at a ratio of fi-IK until a void of 0 to 30 θ0 was obtained, and a die for sheet extrusion was attached to the tip, and the mixture was heated to 2°C.
The mixture was supplied to an extruder and a sheet having a wall thickness of approximately 50 μm was extruded.

The sheet is laminated in a molten state on the upper surface of a separately prepared polycarbonate film with a wall thickness of 75 μm, and immediately a Teflon sheet is further laminated on the upper surface of the sheet, cooled with water, and then fed between rolls. The mixture was cooled and solidified while being crimped using a vacuum cleaner.

After the sheet was cooled, the Teflon sheet was peeled off to obtain a film-like laminate in which a layered product of a polyester composition was laminated on a polycarbonate film.

(Molding of polycarbonate container) A polycarbonate sheet with a wall thickness of 130 μm was molded into Asano Seisakusho FC-IAPA-W! A polycarbonate tray was vacuum formed using a compressed air/vacuum forming machine using a concave deaf tray mold having an engraved shape, 135 cm in length, 58 cm in width, and 18 cm in depth.

(Heat sealing) The thus obtained polycarbonate tray and the laminate were thermally bonded using a heat sealer (a cup sealer manufactured by Noriwa Manufacturing Co., Ltd. modified to be air-operated), and the bonded portion was sealed at 1.
It was cut into 511 mm width and used for evaluation of thermal bonding strength.

The results are shown in Table-1.

All of the laminates of the present invention had good easy-open properties.

Example 1O and Comparative Example 1O The conditions were as follows, except that a polyethylene terephthalate unstretched film with a wall thickness of 80 μm was used as the film-like material, and a tray-shaped thing thermoformed with polyethylene terephthalate with a wall thickness of 500 μm was used as the container. Studies were conducted in the same manner as in Example 1 and Comparative Example 1.

Heat seal strength is 971 to 0.6 and 3.0 respectively
5 tm width, and the effect of the present invention was recognized.

As explained above, the laminate of the present invention had excellent easy-open properties when used as a lid material for a polycarbonate or polyester container at °C.

Claims (1)

[Claims] 1. A thin layer of a composition obtained by melt-mixing 100 parts by weight of a thermoplastic polyester having a melting point of 80 to 200°C and 1 to 100 parts by weight of a polyolefin resin is applied to at least one side of a film-like object. A film-like laminate made by laminating layers. 2. Containing at least 50 mol% of terephthalic acid and/or isophthalic acid as an acid component, and one or two glycols selected from ethylene glycol, neopentylene glycol, tetramethylene glycol, diethylene glycol, and cyclohexaline methanol as a glycol component. The film-like laminate according to claim 1, which is a polyester comprising at least 50 mol% of at least one species. 3. The film-like laminate according to claim 1, wherein the polyolefin resin is low-density polyethylene. 4. Any one of claims 1 to 3, wherein the film-like material is a non-oriented film or a film stretched in at least one axis, the main component being a polyester resin, a polycarbonate resin, or a mixture thereof. The film-like laminate described in .