JPS6245640A - See-through packaging film - Google Patents

Abstract

PURPOSE:To provide the titled film having excellent vacuum moldability, dimensional stability, lubricity and folding processability of a wrapping mount, by molding a vinyl chloride resin contg. a lubricant blended therewith. CONSTITUTION:0.01-3.0pts.wt. lubricant (e.g., synthetic paraffin) having a m.p. or solidifying point of 40 deg.C or above, 10-30pts.wt. plasticizer (e.g. diethyl phthalate) and optionally, additives such as thermal stabilizer, antioxidant, ultraviolet absorber, colorant, etc., are blended with 100pts.wt. vinyl chloride resin to obtain a compsn. The compsn. is molded into a film by T-die extrusion or calendering method, thus obtaining the titled see-through packaging film having a thickness of 20-100mum, tensile stress at yield of 550kg/cm<2> or below and/or tensile stress at 100% modulus of 180kg/cm<2> or above and mold back ratio of 40% or below.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a vinyl chloride resin used for double-sided see-through packaging that secures cosmetics, tools, daily necessities, etc., prevents movement of the products, and allows the products to be seen from both sides. This is related to series films.

[Conventional technology]

For double-sided see-through packaging, first punch out the required amount of paperboard in the center where the product will be stored, and then apply a film to the entire surface of the paperboard or a portion including the punched center to create a packaging mount.

After preheating the packaging paper to which the film is attached, it is held on a predetermined mold equipped with a suction device, and the central film portion is vacuum-formed. In the next packaging process, the product is placed in the vacuum-formed film recess, the packaging paper is folded, and the product is heat-sealed and presented.

In the case of single-sided see-through packaging, in most cases the film is subjected to secondary processing such as heated vacuum or pressure forming to create a recess slightly larger than the product, the product is placed there, and the opening is filled with paperboard, plastic film or sheet, metal foil, or other materials. Cover with composite material, etc., and package with adhesive or heat seal.

Films used for these see-through packaging are often made of rigid vinyl chloride resin films because they require so-called stiffness, including product retention.However, in the case of double-sided see-through packaging, vacuum formability Alternatively, there are problems with the air pressure moldability, the bending processability of the packaging mount, and the heat sealability.

The moldability can be improved by increasing the film preheating temperature, lengthening the preheating time, or increasing the degree of vacuum or pressure chamber.
The amount of processing per unit time decreases, and it cannot be said to be preferable from the viewpoint of resource saving. As a countermeasure to this problem, a soft vinyl chloride resin film is used which has good bending processability, heat sealability, display effect, etc. for the packaging mount. However, in the case of a soft vinyl chloride resin film, the film generally tends to adhere, Because the surface of the film lacks slipperiness, when stacking packaging mounts with films attached to them and placing them in the mount stocker of a packaging machine and taking out the packaging mounts one by one, the films above and below the center of the mounts stick together. It may become impossible to take out the packaging paper one by one, or when the product is placed, the packaging paper is folded, and the product and film are tightly fixed and heat-sealed, the film and product may partially stick to each other and the film may become loose. or the product may not be secured properly.]
In addition, dimensional changes, so-called mold reversion, may occur after vacuum forming and before the product is inserted, and when the product does not fit completely into the recess and the packaging mount is folded, the top and bottom mounts rise up, causing problems in the heat sealing process. Problems such as the following are occurring.

[Problem that the invention seeks to solve]

An object of the present invention is to solve the above-mentioned problems and provide a vinyl chloride resin film for double-sided see-through packaging that has improved vacuum formability, dimensional stability, folding processability of packaging mounts, and slipperiness. .

[Means for solving problems]

As a result of intensive studies to solve these problems, the inventor has found that
By adjusting the tensile yield point stress and 100% tensile stress, the vacuum formability, dimensional stability, and bending processability of the packaging paper can be improved, and if a lubricant with a melting point or freezing point of 40°C or higher is used, The present invention was completed by discovering that the slipperiness of the film can be improved.

That is, the see-through packaging film according to the present invention (made of vinyl chloride resin as a base material, blended with a lubricant having a melting point or freezing point of 40°C or higher, and having a tensile yield point stress of 5
It is characterized by having physical properties of 50 kg/am" or less and/or 100% tensile stress of 180 kg/am" or more.

The present invention will be explained in detail below.

The vinyl chloride resin used in the present invention is a vinyl chloride homopolymer, a vinyl polymer mainly composed of vinyl chloride, and monomers copolymerizable with vinyl chloride, such as ethylene, propylene, vinyl acetate, vinylidene chloride, and noethyl maleate. Examples include copolymers with etc.

These vinyl chloride resins can be obtained by conventionally known polymerization methods such as emulsion polymerization, solution polymerization, bulk polymerization, etc.
Both can be used.

Adjustment of tensile stress, which is a feature of the present invention, is usually carried out using a plasticizer. The preferred usage amount of the plasticizer is 10 to 30 parts by weight, but since there is a large difference depending on the plasticizing efficiency of the plasticizer used, it is necessary to take this point into consideration when determining the usage amount.

As the plasticizer used, any conventionally known plasticizer can be used, but it is preferable to use one that has low migration properties with commercial products. Examples include diethyl phthalate, di-n-phthalate,
Butyl, dihexyl phthalate, di-i-heptyl phthalate, di-n-hebutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, di-i-nonyl phthalate, di-n-nonyl phthalate , di-t phthalate
Phthalate ester plasticizers such as -decyl, n-decyl phthalate, butylbenzyl phthalate, synchhexyl phthalate, ethylene phthalyl ethylene glycolate, butyl phthalyl butyl glycolate, di-2-adipate
Ethylhexyl, di-i-butyl adipate, di-n-hexyl adipate, di-n-hebutyl adipate, di-i-heptyl adipate, di-n-octyl adipate, di-n-nonyl adipate, adipic acid G i-
Nonyl, di-n-decyl adipate, i-adipate
Decyl, di-n-butyl sepatate, di-n sebachate
Aliphatic dibasic acid ester molding agents such as -octyl, di-2-ethylhexyl cepatic acid, di-n-hexyl azelate, di-2-ethylhexyl azelate, diester tartrate, triethyl acetyl citrate, acetyl citric acid Tributyl, tri-2-ethylhexyl acetyl citrate, tributyl citrate, monocitric acid.

Hydroxy polyhydric carboxylic acid ester plasticizers such as di- and tristearyl, methyl acetyl ricinoleate, ethyl valmitate, n-butyl stearate, amyl stearate, cyclohexyl stearate, butyl twinate, hydrogenated rosin methyl ester aliphatic ester plasticizers such as glycerin triacetate, glycerin tripropionate, glycerin tributyrate, glycerin triheptanoate, trimethylene glycol sica plate, trimethylene glycol sica plate, 2゜2, =
1-trimethyl-1,3-pentanedio-Lunow [-
Aliphatic ester plasticizer of polyhydric alcohol such as butylate, Evokinized flower oil, Epokinized Amaniura aliphatic butyl, Epoxy octyl stearate, 3-
Evoquino plasticizers such as (2-xenoxy)-1,2-epoxypropane, poly(propylene glycol, adipic acid) ester, poly(1,3-butanediol, adipic acid) ester, poly(propylene glycol, cepatic acid) ) ester, poly(1,3-butanediol, cepatic acid) ester, poly(propylene glycol, phthalic acid) ester, poly(l,3-butanediol, phthalic acid) Nisdel, poly(ethylene glycol, anovic acid) ester , polyester plasticizers such as poly(1,6-hegisanol, adipic acid) ester, acetylated poly(butanediol, adipic acid) ester, etc. These can be used alone or in combination of two or more. It can be used as

Low amount of plasticizer used, tensile yield point stress of 550
If the film exceeds Kg/cm', the film will be hard and have a good J'
Also, it is not possible to obtain air moldability and bending workability of the backing paper for the package 4. 1.00% tensile stress is 18 due to large amount of plasticizer used
If it is less than 0 Kg/01111, the mold return rate after vacuum forming will be large, and the film will tend to stick together, making it impossible to take out the packaging paper one by one from the packaging machine's paper stocker, or the product may not be fixed properly. becomes.

Products made of polystyrene resins with relatively high plasticizer migration properties, acrylonitrile-butadiene-styrene resins, etc.
When packaging products with printed labels, use internally plasticized vinyl chloride copolymer resins that can reduce the amount of plasticizer used, polyester plasticizers, ethylene-vinyl acetate-carbon oxide copolymer plasticizers, and other molecules Btoooo It is desirable to use the above non-migrating plasticizers.

The packaging film of the present invention preferably has a mold reversion rate of 40% or less. In the present invention, the mold return rate means the dimensional stability of the recesses after vacuum forming the film. If the mold return rate exceeds 40%, the dimensions of the recess will be smaller than the outside dimensions of the product, and the product will not fit completely into the recess, and when the packaging mount is folded and heat sealed, the upper and lower mounts will rise, resulting in insufficient heat sealing. become.

Examples of lubricants used in the present invention include hydrocarbon-based lubricants such as synthetic paraffin, natural paraffin, microwax, and polyethylene wax, fatty acid-based lubricants such as higher fatty acids, and oxine fatty acids;
Fatty acid amides such as aliphatic amides and bis fatty acid amides,
Polyhydric alcohol esters of fatty acids, esters such as fatty alcohol esters of fatty acids, fatty alcohols, partial esters of fatty acids and polyhydric alcohols, partial esters of fatty acids and polyglycols/polyglycerols, waxes and fatty acid polyhydric alcohols Examples include those having a melting point or freezing point of 40° C. or higher, selected from mixtures of esters, waxes, fatty acids, etc. These can be used alone or in combination of two or more. For example, liquid paraffin having a melting point or freezing point of less than 40°C,
Chlorinated hydrocarbons, some higher fatty acids such as capric acid, lauric acid, and isostearic acid, lower alcohols of fatty acids such as methyl stearate and butyl stearate,
Some fatty alcohols such as lauryl alcohol and myristyl alcohol, polyhydric alcohols such as ethylene glycol and diethylene glycol, and partial esters of fatty acids and polyhydric alcohols such as glycerin lysyllate, sorbitan monooleate, and sorbitan monolaurate. In some parts of the system, almost no effect of improving slipperiness can be obtained.

The amount of the lubricant used is preferably 0.01 parts by weight to 3.0 parts by weight, but it varies depending on the compatibility with the resin, so it is more preferably 0.02 parts by weight to 2.0 parts by weight. Q Heavy It
parts, more preferably 0.05 parts by weight to 1.0 parts by weight.

If the amount used is less than 0.01 parts by weight, it will be difficult to achieve the purpose of improving slippage. On the other hand, if it is used in an amount exceeding 3.0 parts by weight, the transparency may be impaired or the product may be contaminated over time due to embossment on the film surface, which may cause problems.

In the present invention, heat stabilizers, antioxidants,
Additives such as ultraviolet absorbers and colorants can be used.

The packaging film of the present invention includes a vinyl chloride resin, a plasticizer,
Mix the lubricant and other additives with a Henschel mixer, etc., and use a well-known method such as the T-die method or calendar method to process the mixture for 20 to 20 minutes.
It can be manufactured by forming a film having a thickness of about 100 μm.

The various physical properties specified in the present invention are measured by the following methods.

(1) Tensile Yield Point A test piece cut into a core ioam was pulled at a speed of 2,000 min. to determine the load at which the film began to stretch, and the stress at the tensile yield point was determined by dividing by the cross-sectional area. The measurements were performed in a constant temperature room at 20°C.

(2) 100% tensile stress: The film was stretched in the same manner as in (1) above, and the load when the film was elongated by 1.00% was divided by the cross-sectional area to determine 100% tensile stress.

(3) Mold return rate: Preheat the film at 120°C for 30 seconds,
Using loam deep mold, vacuum degree 600mm1'1
g for 10 seconds, the depth of the recess was measured immediately after molding and 1 minute later, and the mold return rate was determined using the formula below.

However, Do: Depth of the recess immediately after vacuum forming D: Depth of the recess 1 minute after vacuum forming 4) Vacuum formability: Preheat the film at 80°C for 30 seconds, vacuum form under the same conditions as (3) above, and The depth of the recessed portion of the film was measured and evaluated.

(5) Melting point or freezing point: Measured based on the sections of JIS K 8004 General Test Methods for Reagents, Measurement of Melting Point and Measurement of Freezing Point.

(6) Slip property: The film is pasted on a 20x40cm metal plate, and the area where the film is pasted on it is 8x16Cfl.
A stone with a metal plate with a load of 509. 500 times per minute this metal plate
It was slid at a speed of III+H9, and the load at that time was measured.

The smaller the numerical value is, the more preferable it is, but if it is 809 or less, there is no substantial problem.

(7) Transparency (haze value): Measured using an integrating sphere type light transmittance measuring device based on a methacrylic resin plate for aircraft according to JIS K 6714.

It is usually 3% or less, preferably 2% or less.

〔Example〕

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

Examples 1 to 7 100 parts by weight of vinyl chloride resin with an average degree of polymerization of 1050, 5 parts by weight of epoxidized soybean oil, di-2-ethylhexyl adipic acid (DOA) or a polyester plasticizer with an average molecular weight of 2000 are shown in Table 1. 0.5 parts by weight of calcium stearate, 0.5 parts by weight of zinc stearate, and a lubricant such as ethylene bisamide in the amounts shown in Table 1 were mixed in a Henschel mixer, further screw-kneaded in an extruder, and then mixed in a T-die. Melt extrusion was carried out at about 200° C., and a film having a thickness of about 70 μm was obtained by winding up by a conventional method. The resulting film was measured for tensile yield point stress, 100% tensile stress, mold reversion rate, slipperiness, vacuum formability, and transparency.

The results are shown in Table 1.

By adjusting the tensile yield point stress and/or 100% tensile stress, a film with excellent mold reversion rate and vacuum formability was obtained, and by using a lubricant with a melting point or freezing point of 40°C or higher, a film with excellent slipperiness was obtained. .

Comparative Examples 1 to 3 Films were obtained in the same manner as in the Examples except that plasticizers and lubricants shown in Table 1 were added. The mold return rate, vacuum formability, slipperiness, and transparency were poor.

〔Effect of the invention〕

As is clear from the above description, the present invention uses vinyl chloride resin as a base material to increase tensile yield point stress and/or 100
Excellent vacuum formability by adjusting % tensile stress,
By using a lubricant that has dimensional stability after vacuum forming and bending processability of the packaging mount, and has a melting point or freezing point of 40°C or higher, it is possible to provide a see-through packaging film that has excellent sliding properties. This packaging film is extremely useful industrially, including resource saving.

Claims (3)

[Claims] (1) Made of vinyl chloride resin as a base material, blended with a lubricant having a melting point or freezing point of 40°C or higher, and having a tensile yield point stress of 550 kg/cm^2 or lower and/or 1
A see-through packaging film characterized by having a physical property of 00% tensile stress of 180 kg/cm^2 or more. (2) Claim 1 in which the mold return rate is 40% or less
See-through packaging film as described in section. (3) The lubricant is 0.01 to 3.0% per 100 parts by weight of the base resin.
The see-through packaging film according to claim 1 or 2, wherein the film contains 0 parts by weight.