JPH0640459A - Packaging bag equipped with fitting tool and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a high strength of adhesion by a method wherein a fitting tool consisting of a male claw and female claw, which is provided at the opening of a resealable packaging bag, is formed of a terpolymer of ethylene, an anhydride of alpha,beta-unsaturated dicarboxylic acid and unsaturated carboxylic acid ester. CONSTITUTION:The fitting tool consists of a male claw part and female claw part which are engaged to each other, and is adhered at the opening of a packaging bag at the bottom surfaces (length (a), (a')=2-30mm) of the male claw part and female claw part. For such a fitting tool, as the raw material, a terpolymer of ethylene, an anhydride of alpha,beta-unsaturated dicarboxylic acid and unsaturated carboxylic acid ester is used. Also, at the time of manufacturing a packaging bag, the terpolymer is molten extrusion-molded at temperature of approximately 100-300 deg.C using a die. At the same time, a bag raw material is obtained by bonding the bottom surfaces of the male claw part and female claw part under a molten state, and the bag raw material is made into a bag to form a packaging bag equipped with a fitting tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag with a fitting and a method for industrially producing the packaging bag with a fitting, and the obtained packaging bag with a fitting. Is a drug,
It can be widely used in the field of resealable packaging bags in which foods, clothes, and other various articles can be freely taken in and out.

[0002]

2. Description of the Related Art A typical method of manufacturing a packaging bag with a fitting, which is currently used, is roughly classified into a mating portion for male and female claws and a bag main body at the same time by a T-die method or an inflation method. A method of molding it into a bag with a fitting tool, and pre-molding only the fitting part, and pasting the fitting tool to the desired film substrate in another process to make a bag with a fitting tool. There are two ways to go.

In the case of the former method, it is extremely convenient because it is possible to manufacture a bag raw material with a fitting at one time, but from the viewpoint of industrial production, the type of bag base material is greatly limited. For example, it is difficult to manufacture a packaging bag with a fitting provided with a special function such as a gas barrier property by this method. In addition, since there is a difference in the degree of shrinkage between the bag body and the fitting portion, shrinkage wrinkles are formed around the fitting portion, and the appearance deteriorates.
Therefore, it is extremely difficult to print on such a surface.

In the case of the latter method, a film base material having a good appearance can be used, so that there is no restriction in printing or the like. However, the work is complicated and the cost is high.
Moreover, the fittings that are generally manufactured are limited to those made of polyolefin such as polyethylene and polypropylene, and unless special treatment is applied, the adhesiveness to different materials is poor and the original purpose is I haven't.

Therefore, a method (Japanese Patent Publication No. 50-11827) and an apparatus (Japanese Patent Publication No. 49-49) for continuously and automatically joining a fitting portion to a previously prepared film substrate while extruding and molding the fitting portion. No. 48033) has been proposed. In this skeleton of the prior art, it is difficult to bond the fitting portion to the film base material well, so the temperature of the film base material must be raised to around its softening temperature. for that reason,
Although it has been proposed to install a heating roll or a special heating chamber,
Depending on the type of film base material, various problems may occur at high temperatures, so that it is also necessary to adjust the humidity. In addition, complicated conditions must be set for cooling, which is problematic.

[0006]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the prior art, has excellent adhesiveness between various film or sheet substrates and fittings, and has fittings with good appearance and printability. The packaging bag and this packaging bag with fittings are well bonded to various film or sheet base materials while extruding the fitting part without using special equipment or complicated processes. It is an object of the present invention to provide an industrially advantageous method for producing a packaging bag with a fitting, which is advantageous.

[0007]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors have found that by using a specific resin for a fitting portion, it can be easily bonded to various base materials. The present invention has been achieved by finding that it can be used as a packaging bag with a fitting.

That is, according to the present invention, in a packaging bag with a fitting, provided with a fitting consisting of a pair of male and female claws to be fitted to each other near the opening of the bag body, the fitting is made of ethylene. ,
The present invention relates to a packaging bag with a fitting, which is formed from a terpolymer of an anhydride of an α, β-unsaturated dicarboxylic acid and an unsaturated carboxylic acid ester.

The present invention also provides a male nail portion obtained by melt-molding a ternary copolymer of ethylene, an anhydride of α, β-unsaturated dicarboxylic acid and an unsaturated carboxylic acid ester on a film or sheet substrate. And a bottom surface of the female claw portion in a molten state to obtain a raw material bag, and the raw material bag is manufactured into a bag.

The resins used to make the fittings of the present invention are terpolymers of ethylene, anhydrides of α, β-unsaturated dicarboxylic acids and unsaturated carboxylic acid esters. As the α, β-unsaturated dicarboxylic acid anhydride of the second comonomer component used for producing the terpolymer, the α, β-unsaturated dicarboxylic acid anhydride shown below is preferably used. To be The α, β-unsaturated dicarboxylic acid has at most 20 carbon atoms, and particularly preferably has 4 to 16 carbon atoms. Maleic acid, itaconic acid, citraconic acid, and 3,6-endomethylene-1,2,3,
Anhydrides of α, β-unsaturated dicarboxylic acids such as 6-tetrahydro-cis-phthalic acid are preferred.

Examples of the unsaturated carboxylic acid ester which is the third comonomer component include alkyl (meth) acrylate and alkoxy (meth) acrylate. Of these, alkyl (meth) acrylates generally have 4 to 30 carbon atoms, and particularly 4 to 30 carbon atoms.
20 is preferable. Typical examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. Furthermore, alkoxyalkyl (meth)
For acrylates, the carbon number is usually at most 20. In addition, an alkyl group having 1 to 8 (preferably 1 to 4) carbon atoms is preferable. Further, it is desirable that the alkoxy group has 1 to 8 (preferably 1 to 4) carbon atoms. Suitable alkoxyalkyl (meth) acrylates include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-methoxyethyl acrylate, ethoxyethyl acrylate, and butoxyethyl acrylate.

In the terpolymer, the copolymerization ratio of the α, β-unsaturated dicarboxylic acid anhydride is generally 0.
005-3 mol%, especially 0.05-2.5 mol%
Is preferred. When the copolymerization ratio of the α, β-unsaturated dicarboxylic acid anhydride is less than 0.005 mol%, the polarity is insufficient,
Sufficient adhesion cannot be obtained. On the other hand, if it exceeds 3 mol%, not only the production of the terpolymer becomes unreasonable and stable production becomes difficult, but also the absorption of moisture in the air by the anhydride of α, β-unsaturated dicarboxylic acid. This is not preferable because the amount increases and foaming occurs during molding.

The copolymerization ratio of the unsaturated carboxylic acid ester which is the third comonomer component is usually at most 10 mol%, and particularly preferably 0.5 to 5 mol%. If the copolymerization ratio of unsaturated carboxylic acid ester exceeds 10 mol%, not only the molding of the fitting portion becomes difficult because the molecular weight and crystallinity of the terpolymer decrease, but also the fitting strength increases. It is not preferable because it decreases. The terpolymer has good extrusion moldability, and the fitting tool can be easily manufactured.

The above terpolymer can be used as it is for the fitting portion consisting of the male and female nails according to the present invention, but it is better to use a lubricant together with the terpolymer. It is preferable because the fitting property between the female nail and the female nail becomes better. Examples of the lubricant that can be used in the present invention include liquid paraffin, natural paraffin, microwax, synthetic wax, hydrocarbons such as low molecular weight polyethylene, fatty acids such as stearic acid, stearic acid amide, palmitic acid amide, methylenebisstearylamide, Fatty acid amide series such as oleic acid amide, lower alcohol ester of fatty acid, ester series such as polyhydric alcohol ester of fatty acid, aliphatic alcohol,
Examples thereof include alcohols such as polyhydric alcohols and metal soaps such as calcium stearate. These lubricants can be used alone or in combination of two or more.

The amount of the lubricant used is ternary copolymer 10
0.01 to 2 parts by weight is preferable with respect to 0 parts by weight. A particularly preferred amount used is 0.03 to 1.5 parts by weight. When the amount of the lubricant used is less than 0.01 parts by weight, the effect of improving the fitting property is small when the male and female claws formed by melting are solidified by cooling and then immediately fitted. On the other hand, if the lubricant is used in an amount of more than 2 parts by weight, the molded fitting will be whitened,
It is not preferable because the adhesiveness of the packaging bag to the substrate is lowered.

The terpolymer used in the present invention includes, in addition to the above-mentioned lubricants, commonly used heat stabilizers, antioxidants, ultraviolet absorbers, antiblocking agents, antistatic agents,
Of course, it is possible to add various additives such as an antifogging agent, a flame retardant, and a coloring agent. Further, depending on the purpose, it is also possible to partially use other resins such as polyethylene, polypropylene and polyvinyl chloride.

The shapes of the male and female claws, which are the constituent elements of the fitting part obtained by molding the terpolymer, are not particularly limited as long as the functions can be fulfilled, but as an example, the respective shapes. 1 and 2 are cross-sectional views. In FIGS. 1 and 2, the lengths a and a'of the bottom surface (or bottom plate) of the nail are 2 to 30 mm, preferably 3 to 20 mm when bonded to the base material. The bottom thicknesses b and b'are 0.04 to 3.0 mm, preferably 0.0 when bonded to the substrate.
It is 8 to 2.0 mm. a and a'length is less than 2 mm,
Alternatively, if the thickness b and b'is less than 0.04, the adhesion to the film or sheet substrate is insufficient.
On the other hand, when a and a'exceed 30 mm, the film base material may be wrinkled and the adhesive surface may be damaged, resulting in impaired appearance. Further, when the thickness of b and b'exceeds 3.0 mm, not only shrinkage and wrinkles may occur in the film base material, but also side sealing during bag making becomes difficult and productivity is lowered, which is preferable. Absent.

For molding the fitting portion, a die having a cross-sectional shape as shown in FIGS. 1 and 2 is used, and the temperature is 100 to 300 ° C., preferably 130 to 270 ° C., in an ordinary extruder. Melt and mold. If the molding temperature is lower than 100 ° C., not only the molding becomes difficult, but also the adhesiveness to a substrate such as a film decreases. On the other hand, if the temperature exceeds 300 ° C,
It is not preferable because the terpolymer is deteriorated. In the present invention, the male claw portion and the female claw portion extruded from the mold have their bottom surfaces brought into contact with the film or sheet base material when they are in a molten state. It is desirable that the time from when the male and female nails leave the mold until they contact the film or sheet substrate is within 1 second. After the pressure is applied and the bonding is completed, in order to stabilize the shape of the claws as quickly as possible, it is particularly preferable to perform forced cooling such as water cooling or air cooling on the claw portions. The base material to which the fitting part is bonded is folded in half and after fitting the male claw part and the female claw part, the end is cut to a specified width using heat etc. Can be

As the base material of the packaging bag which can be used in the present invention, polyethylene, polypropylene, polyvinyl chloride,
Examples thereof include various synthetic resin films or sheets such as polyester and polyamide, metal sheets or foils such as aluminum, iron and copper, and paper, cloth, non-woven fabric, synthetic paper and the like. These base materials can be used alone, but can also be used in the form of a composite film or composite sheet by forming a multilayer.

[0020]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

Example 1 A stainless steel rotating roll is installed at a position substantially close to the male and female claw dies attached to the outlet of the extruder. A 50 μm-thick laminated film made of nylon / polyethylene is applied to this roll, and the winding is continued while pulling. On the polyethylene-side surface of this laminate film, the ethylene content was 96.8 mol%, the maleic anhydride content was 0.9 mol%, the methyl methacrylate content was 2.3 mol%, and the MFR was 8.1 g / 10. A portion of the ethylene-maleic anhydride-methyl methacrylate terpolymer was extruded through a mold to press the male and female nails as shown in FIGS. The resin temperature immediately after extrusion was 210 ° C. The adhered male nail portion and female nail portion were cooled by spraying cooling water from a nozzle.

Not only the appearance of the base material of the obtained packaging bag with fittings but also the adhesiveness between the base material and the claws were very good. Also, the fitting property between the male and female claws was good.
The widths (a and a ') and the thicknesses (b and b') of the bottom surface of the chuck portion shown in FIGS. 1 and 2 were measured from the bonded base material to be about 7 mm and about 0.3 mm, respectively. It was

Example 2 To 100 parts by weight of the terpolymer used in Example 1, 0.2 parts of stearic acid monoglyceride was used as a lubricant.
Fitting in the same manner as in Example 1 except that 5 parts by weight was blended and a degreased aluminum foil having a thickness of 10 μ was used in place of the nylon / polyethylene laminate film used in Example 1. Glued the parts together. The appearance of the obtained packaging bag with a fitting was good, and the claw portion and the aluminum foil were extremely strongly bonded. Further, the fitting property between the male and female claws was extremely good.

Comparative Examples 1 and 2 Instead of the terpolymer used in Example 1, MFR was 6
A laminate film made of nylon / polyethylene having a thickness of 50 μ (Comparative Example 1) and an aluminum foil having a thickness of 10 μ (Comparative Example 2) were manufactured in the same manner as in Example 1 except that low density polyethylene of g / 10 min was used. ) Was examined for adhesiveness of the fitting part. Although there was no problem in moldability, good adhesion was not obtained on any of the substrates.

[0025]

EFFECTS OF THE INVENTION The packaging bag with a fitting of the present invention has a good appearance of the bag body base material, and has excellent adhesiveness between the bag body base material and the fitting portion composed of male and female claws. Moreover, the male claw portion and the female claw portion are excellent in fitting property. Further, according to the method for manufacturing a packaging bag with a fitting according to the present invention, while extruding the fitting portion without using special equipment or complicated steps, various film or sheet base materials can be formed. It is possible to manufacture a packaging bag with a fitting, which can be joined to each other industrially advantageously.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of male pawls of a fitting tool of the present invention.

FIG. 2 is a sectional view showing an example of a female claw of the fitting tool of the present invention.

[Explanation of symbols]

 a, a'Length of bottom surface (or bottom plate) of claw b, b'Thickness of bottom surface (or bottom plate) of claw

Claims (2)

[Claims] 1. A packaging bag with a fitting, comprising a fitting consisting of a pair of male and female claws to be fitted to each other near the opening of the bag body, wherein the fitting is ethylene, α, β. A packaging bag with a fitting, which is formed from a terpolymer of an unsaturated dicarboxylic acid anhydride and an unsaturated carboxylic acid ester. 2. A male and female nail portion formed by melt-molding a ternary copolymer of ethylene, an anhydride of α, β-unsaturated dicarboxylic acid and an unsaturated carboxylic acid ester on a film or sheet substrate. A method for producing a packaging bag with a fitting, wherein the bottom of the bag is adhered in a molten state to obtain a bag raw material, and the bag raw material is manufactured into a bag.