JPS61167A - Manufacture of air-permeable packaging material - 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] (Technical field of invention) The present invention relates to a method for manufacturing breathable packaging materials.

More specifically, the present invention relates to a method for manufacturing a laminate of a porous film material and a perforated film material.

(Technical background) Conventionally, there have been products that interact with specific components in the air, such as desiccants, oxygen scavengers, freshness-preserving agents, deodorizing agents, and heat-generating agents, as well as insect repellents, repellents, and fragrances. A laminate with controlled air permeability to a desired degree is used as a material for sachets that contain substances that can be vaporized into the air to achieve specific effects.

The following are known as these breathable laminates.

(1) Non-woven fabric or paper is used as a base material, and a heat-sealable resin is laminated using extrusion coating technology, and then microscopic holes are drilled through the front and back sides in a post-processing process.

(2) Non-woven fabric or paper is used as a base material, and a heat-sealable resin film is laminated using dry lamination technology, after which fine holes penetrating the front and back sides are drilled in post-processing.

(3) As a nonwoven fabric or paper substrate, a heat-sealable perforated film with small holes is bonded by thermocompression.

The ventilation holes in (1) and (2) above are usually processed by piercing with needle-like protrusions from the side of the nonwoven fabric, or by slitting by making discontinuous linear cuts from the side of the film. It is. When the laminate is made into a bag by providing ventilation holes using these methods, there is a drawback that the contents leak out and the surrounding area gets dirty. In addition, in method (3), wrinkles may occur due to stretching of the perforated film during thermocompression bonding, and deformation of the holes may occur. The drawback is that it cannot be done.

(Prior Art) Recently, a plastic film (hereinafter abbreviated as porous film material) in which a large number of fine through-holes are present over the entire plane of the front and back surfaces has been developed, and is used in applications that require breathability. It became so. When using such a porous film material as a material for a breathable pouch, it is necessary to laminate it with other materials for the following reasons.

l) Many porous film materials themselves do not have heat-sealability, and even if they do, they are insufficient for use in filling bag-making machines, so it is necessary to laminate them with a material that has good heat-sealability.

2) Depending on the application, the strength of the porous film material itself may not be enough to provide practical strength for the pouch, and it may be necessary to laminate it with a reinforcing material.

When using films that do not inherently have air permeability as these heat-cooling or reinforcing materials, it is necessary to make through holes only in these materials by some method. This is because if holes of the same size are made in a porous film material, the contents will leak out as described above. Therefore, it is necessary to make holes in these materials or a laminate of these materials in advance to obtain a perforated film material, and then to completely bond this material with a porous film material. That is, this is lamination of a perforated film material and a porous film material.

By adjusting the shape, size, distribution, etc. of the pores in the perforated film material, it is possible to obtain a packaging material whose ventilation rate is controlled to a desired degree.

The method of bonding perforated film materials with porous film materials is the thermocompression bonding method mentioned above (t. Since the pores are deformed, packaging materials with high precision air permeability cannot be manufactured at a speed that can be put to practical use.

- Also, a dry lamination method is a well-known method for laminating non-porous films and nonwoven fabrics. This general mechanism involves coating an adhesive open-tube nonporous film in the coating section using a gravure method or three-snow roll method, and evaporating the solvent in the coating solution in the drying section to dry it.
In the laminating section, the adhesive is laminated with a separately drawn out non-woven fabric and then wound up, and then left for a certain curing time to harden the adhesive.

However, when such a dry lamination method is used to bond a perforated film material and a porous film material, the adhesive on the applicator roll passes through the holes in the perforated film material and is transferred to the notokup roll. This transfers to the back side of the rotating ')'&vcM tag film material, and after pasting, the packaging material wound up into a roll is transferred again and the fixed adhesive hardens, causing it to open. This method has the disadvantage of causing a blocking phenomenon. One possible method to prevent this blocking phenomenon is so-called pattern coating, in which a gravure plate roll is used to apply adhesive to a perforated film material, avoiding the pores. In order to prevent this, it is necessary to set the registration accuracy range to the size of the hole diameter plus the non-image area (non-adhesive coated area), and the laminate where the film is raised without adhesive being attached around the hole. It is difficult to deal with roll stains that occur when the rolls are out of register at the beginning or during processing, and current dry laminators are usually not equipped with a register adjustment mechanism. This method is difficult to implement because of the

It is also possible to clean the adhesive that has passed through the perforations of the perforated film material and transferred to the knock-up roll while the roll rotates once, but this roll is located in a narrow space. There is still no known method to effectively clean it.

(Object of the Invention) The present invention provides a porous film material that can control the amount of air permeation to a desired level by laminating a porous film material with a constant shape, size, and distribution of pores using an adhesive. It is intended to provide a complete method of manufacturing heat-sealable packaging materials.

(Structure of the Invention) That is, in the present invention, a paper feed film is brought into contact with one side of a perforated film material whose main component is a thermoplastic resin, and after fully coating the other side of the perforated film material with an adhesive, A method for producing a breathable packaging material, which comprises peeling and removing a perforated film material, and then laminating a porous film material containing a polyolefin resin as a main component to the adhesive-coated surface of the effective film material. be.

The structure of the packaging material obtained by the method of the present invention will be explained with reference to the accompanying drawings.

The accompanying figures 1 to 3 are cross-sectional views of packaging materials obtained by the method of the invention.

In FIG. 1, l represents a porous film material, 2 represents a perforated film material, 3 represents an adhesive, and 4 represents holes 7.

That is, FIG. 1 shows a case where a film having heat sealability is used alone as a perforated film material.

FIG. 2 shows a case in which a reinforcing film 5 and a heat-sealable film 6 are laminated and holes are formed to form a perforated film leaf material.

FIG. 3 shows a case in which a reinforcing film and a heat-sealable film are formed into one film by co-extrusion, and holes are formed in this film to form a perforated film material 2'.

Next, regarding the continuous manufacturing method of packaging materials of the present invention, the fourth
This will be explained with reference to the figures.

A perforated film material 2 is fed out from a perforated film material feed roll 7, and a waste paper film feed roll 8 is fed out on the other hand.
The paper feed film 9 is fed out from the holder, and the paper feed film 9 is double fed into the coating section while keeping both molds pressed together so that the perforated film leaves are in contact with the side facing the notch up roll 12 of the coating section. Paper. In the coating section, when the film material passes between the application roll 11 and the knock-up roll 12, the adhesive solution lO is applied to the perforated film material by the application roll. The perforated film material completely coated with the adhesive solution is sent to the drying section 13, where the perforated film material is separated from the paper feed film and advances to the laminating section. The feed film separated from the perforated film material is rolled up in a waste paper film winding section.

In the bonding part, a porous film material feeding roll 15
When the porous film material 1 fed out passes between the press roll 16 and the knock-up roll 17, it is pressed and bonded to the adhesive-coated perforated film material 2. The packaging material that has been completely pasted is sent to the packaging material winding section 18.
It is rolled up at 1c.

(Dry laminating device) By the method of the invention, packaging materials can be produced continuously, as already explained in the section on the structure of the invention. As shown in Figure 4, the device used in this case is a general dry laminating device, with the addition of a feeding device for feeding the paper film and a device for winding it up. be.

However, when using a dry laminating machine equipped with a two-shaft feeder for continuous paper feeding, if the perforated film material is hung on one shaft and the paper feed film is hung on the other shaft, it is necessary to Only a paper film winding device is added.

(Porous film) The porous film material used in the present invention is an air-
For practical purposes, the maximum equivalent diameter determined by the methanol-based maximum bubble pressure method is usually 50 μm or less, preferably 30 μm or less for all the through-holes. In the present invention, the equivalent diameter is defined as the diameter of a circle with an area equal to the area of the hole.

Porous film materials mentioned here include polyolefin resin fibers such as polyethylene, polyethylene, and polyethylene, which are layered randomly and bonded together by heating and pressurizing, or similar polyolefin resins with calcium carbonate, silicon dioxide, and oxidation. These include those that are extruded into a sheet after dispersing inorganic powder such as aluminum, or those that are completely stretched or treated with acid or the like.

Typical examples of porous film materials include Typec (manufactured by DuPont, USA), NF Sheet (manufactured by Tokuyama Soda), and Cellpore (manufactured by Tanemizu Kagaku Kogyo), which are generally commercially available and suitable.

Perforated film materials used in the present invention include:
It has pores with a larger area than the micropores of the porous film material, and there are no particular restrictions on the shape of the pores, but there are no protrusions around the pores, cut-out holes, or discharge damage. It may be a hole, for example, circular, oval, or square, or it may be a slit-like hole. The area of each of these pores varies depending on the use of the packaging material and cannot be unconditionally specified, but in practice it usually ranges from 0.07 aj' to 4 c.
d.

(Perforated film) There are no particular restrictions on the thermoplastic resin for the perforated film material as long as it has good heat sealability.
The materials are polyolefins such as polyethylene and prizolopyrene, and copolymers of ethylene and vinyl acetate (hereinafter referred to as FiV).
(abbreviated as "A"), single-layer films made of myonomers, or multilayer films thereof are used. In particular, when full strength is required, for example, stretched films of polypropylene, polyethylene terephthalate, nylon, etc., and polyethylene, EVA, ionomers, etc. are used. A laminated film with good heat-sealing properties such as the following is used.

(Waste paper film) The waste paper film used in the present invention is not particularly limited as long as it is a film that is suitable for running when applied to a machine, but examples include stretched polypropylene film, Films, etc. are generally inexpensive and suitable for use. In addition, during the production of packaging materials, the amount of adhesive that adheres to waste paper film during one application of adhesive varies depending on the size of the holes in the perforated film material, but in general, it is a very small amount. Therefore, the same film can be used several times.

(Adhesive) The adhesive used in the present invention is not particularly limited as long as it can dry-laminate the porous film material and the perforated film wing material, and examples include acrylic, vinyl acetate, and urethane adhesives. , rubber-based adhesives, among others, adhesive, room temperature curable,
A two-component urethane adhesive is particularly preferred from the viewpoint of heat resistance and flexibility.

The amount of adhesive applied to the perforated film material should be enough to dry-laminate the perforated film material and the porous film wing material in 1 minute. Usually, the amount is 3 to 30% in terms of solid content.
It is about Lot/-.

In addition, dry lamination of a perforated film material and a porous film wing material can be performed at a speed comparable to that of dry lamination of a non-porous film and a nonwoven fabric, as shown in Figure 4. In such equipment, the distance is usually 20 to 150 m/-.

(Effects of the Invention) By the production method of the present invention, wrinkles occur when the perforated film material is laminated to the porous film material. Fluctuations in the size, shape and distribution of the pores of the perforated film material and the perforated film material A packaging material that has the desired air permeability and excellent processability, completely eliminating various defects that could not be prevented with conventional methods, such as blocking phenomenon caused by transfer of adhesive to the back side and clogging of pores in porous film materials. It has become possible to manufacture it continuously at high speed. Therefore, by using this packaging material, it is possible to create a storage bag that has ventilation characteristics suitable for each use and that prevents drug powder from leaking out.

(Examples) Examples are shown below to explain the present invention more specifically, but the following examples are not intended to limit the present invention.

Example: Urethane anchoring agent (AD527, manufactured by Toyo Morton Co., Ltd.) for a polyethylene terephthalate film (ESPET 12, manufactured by Toyobo Co., Ltd.) with a thickness of 12 microns.
Coating was carried out using the gravure method (screen lines 150 lines/inch, plate floor 40 microns), extrusion coating of polyethylene (Sumikasen L705 manufactured by Sumitomo Chemical C Co., Ltd.) e13 microns was applied, and then ionomer resin (Mitsui Chemical Co., Ltd.) A 500m5+ multilayer film coated with 25 microns of Hymin AM6004 (manufactured by Polychemical Co., Ltd.) was used as a raw material for a perforated film material. Circular holes with a diameter of 2 diameters were punched out on one side of this original fabric using a continuous punching machine using a continuous chisel turn at an interval of 15 m + 15 m in the vertical and horizontal directions to obtain a perforated film material. This perforated film material and an untreated biaxially oriented polypropylene film (manufactured by Tone Co., Ltd.) with a thickness of 20 microns and a width of 600 m5, Lefan BO-2500-S2
0) as a paper feed film to the coated area of the Dry 2minator as shown in Figure 4 while continuously doubly feeding the paper at a speed of 80 m/-. BH36020 (A+B liquid) manufactured by Morton Co., Ltd. was coated using the gravure method (screen line count xsOH/inch, board bed 40 microns), and after passing through the entire drying stage, the paper feed film was rolled up. The perforated film material was dry laminated with a 120 micron thick porous film material (NF-120-6 manufactured by Tokuyama Soda Co., Ltd.) that was separately fed.

After leaving this laminate in a curing room at 40°C for 24 hours, it was finished with slits, resulting in a width of 440 m and a length of 1000 m.
of packaging material was obtained. This packaging material has no wrinkles, no deformation of the holes in the perforated film, and no blocking phenomenon.

This is the method for manufacturing the packaging material of the present invention.

(Application example) Nylon Snozend non-woven fabric (Mukasei Co., Ltd.) Extrusion coated with polyethylene to a thickness of 30 microns and ionomer to a thickness of 20 microns on a 40 t/m2 non-woven fabric with a slit finish. Breathable laminate
.

By stacking the perforated film material side surface of the packaging material of the present invention obtained in Example 9 so that the ionomer side surface of the non-breathable laminate faces each other, and thermally bonding the three peripheral edges thereof. I made a complete bag with the M moving part being 120x85 fake. Fill this bag with 5 of a composition that generates heat by reacting with oxygen in the air, which is a mixture of 28 parts of iron powder, 8 parts of activated carbon, 10 parts of water, 3 parts of karite, and 1 part of common salt, and then close the opening. It was heat sealed to make a heating element. When the heating element thus obtained was attached to a human body over a piece of underwear, a comfortable temperature of 40 to 50°C continued for about 30 hours. In addition, leakage of contents to the outside through the holes, which tends to occur in the case of bags in which through-holes are made on the front and back with a needle or the like in post-processing, can be avoided.
It didn't happen at all.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views of the bag-making material of the present invention, and FIG. 4 is a process explanatory diagram when the manufacturing method of the present invention is carried out completely continuously. The symbols in the drawings represent the following. ]... Porous film material, 2... Perforated film material, 2'... Coextruded film, 3... Adhesive, 4...
... Holes of perforated film, 5 ... Reinforcing film, 6
... Heat sealable film, 7... Perforated film material feed roll, 8... Paper feed feed roll, 9...
- Paper feed film, 10... Adhesive solution, 11... Application roll, 12-... Notch up roll, 13... Drying section, 14... Paper test film winding section, 15 ...Porous film material feed roll, 16
...Press roll,]7...Notock up roll, 18...Packaging material winding section

Claims (2)

[Claims] (1) A waste paper film is brought into contact with one side of a perforated film material whose main component is a thermoplastic resin, and an adhesive is applied to the other side of the perforated film material. 1. A method for producing a breathable packaging material, which comprises peeling and removing the porous film material, and then laminating a porous film material containing a polyolefin resin as a main component to the adhesive-coated surface of the porous film material. (2) The method for producing a breathable packaging material according to claim 1, wherein the area of each hole of the perforated film material is 0.07 mm^2 to 4 cm^2.