JPS6119314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to providing a thermoplastic resin layer having a predetermined shape on a base sheet using thermoplastic resin powder. That is, a layer that will become an adhesive layer is formed in advance on a base sheet in a predetermined shape using a method such as a gravure plate coating method, and a thermoplastic resin powder is adhered thereon by a method such as a scattering method.
The present invention relates to a method for producing a thermoplastic resin film, which is characterized by forming a thermoplastic resin film in a predetermined shape on a base sheet by melting and welding thermoplastic powder by heating or hot pressing.

Conventionally, methods for forming a thermoplastic resin, such as polyethylene resin film, on a base sheet include a melt extrusion method using an extruder, a method of bonding a previously formed resin film to the base sheet, and the like. However, with these methods, the film formed is continuous, and it is extremely difficult to create a predetermined shape or special pattern. In addition, as a method of forming a predetermined shape or pattern, an electrostatic coating method in which powder particles are charged and transferred and fixed, or the resin powder is dispersed and suspended in a solution in which a compatible resin is dissolved in an organic solvent or the like. There is a method of applying and forming a fluid coating solution. In this case, the dissolved resin acts as a coating aid.

However, the former electrostatic coating method requires complicated equipment, has practical problems, and is expensive to manufacture. In the latter case, it is easy to form a predetermined shape pattern by, for example, a gravure plate coating method, but the formed film contains other resins as coating aids in addition to the resin. A single layer of only resin cannot be obtained. Therefore, it becomes a factor in terms of physical properties, such as inhibiting heat sealability.

The present invention compensates for all of the above-mentioned problems and drawbacks, and provides a method for easily forming a thermoplastic resin layer in a predetermined shape pattern on a base sheet.

To explain the present invention in detail, on the base sheet,
A resin layer having adhesive properties is formed into a predetermined pattern using a method such as gravure printing or screen printing. In this case, it is still useful if the resin layer has strong adhesiveness to the base sheet.
For example, when the base sheet is aluminum foil, the resin layer is made of polyamide, vinyl acetate, etc., and when the base sheet is polyester film, the resin layer is made of ester resin. These resins are dissolved in an organic solvent or the like to form a pattern, but the surface is sufficiently sticky when the solvent is not volatilized.

Next, a layer of thermoplastic resin powder is deposited on top of this along this pattern. A wide variety of thermoplastic resin powders can be used, including polyethylene, polypropylene, polyamide, ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, polystyrene polyvinyl chloride, and ionomer.
The particle size can vary from 10μ to 500μ. One of these thermoplastic powders or
A mixture of two or more types is adhered onto the adhesive layer by a scattering method or the like, and then heated to a temperature higher than the melting point of the powdered resin to melt the resin powder and obtain a uniform resin film layer. At this time, if a heating roll or the like is used, the surface properties are further improved.

In addition, when the thermoplastic resin powder is deposited and layered on the adhesive layer by spraying or coating, excess powder that adheres to areas other than the predetermined shape and pattern can be easily removed using methods such as blowing with air. .

Here, it is preferable to select a combination of adhesive resin and thermoplastic resin powder that are compatible with each other. Specifically, when polyethylene resin is used as the thermoplastic resin powder, adhesive resins include chromalin resin, wax, polychirpene resin, butyl rubber, cyclized rubber, etc., and when polypropylene resin is used As the adhesive resin, a chlorinated polypropylene resin or the like is preferably used, and when a polyamide resin is used, a combination with an amide resin is preferable.

Various materials such as plastic sheets, fibers, paper, and metal sheets can be used as the base sheet, but it is important that the base sheet can be heated to a predetermined temperature. For example, when using polyethylene resin powder, a suitable molten film can be obtained by heating it at 130 to 200°C for several minutes, but in this case, as a base sheet,
It is required to have heat resistance higher than this.

The thermoplastic resin powder used in the present invention can be produced by a mechanical pulverization method in which pellets are mechanically pulverized using a refrigerant such as liquid nitrogen, or a chemical method in which a resin dissolved in a parent solvent is precipitated using a non-solvent. It is obtained by an appropriate method such as a commercially available pulverization method. Further, instead of using a sticky resin solution, it is also possible to use a sticky solvent alone or a solvent mixed with an appropriate gelling agent. Specifically, there are solvents such as ethyl acetate and butyl cellosolve acetate.

A more detailed explanation will be given below with reference to the drawings.

As shown in FIG.
A resin layer 2 is formed in a pattern using a resin solution in which a sticky resin is dissolved using a rotary screen plate (a rotary screen plate is shown in the drawing). Next, the thermoplastic resin powder 4 filled in the hopper 3 is dispersed by a vibrating sieve 6 through a supply roll 5. Next, excess resin powder adhering to areas other than the pattern is removed by an air brush 7, and the powdered resin is melted in a heating oven B to form a film, which is heated and pressed by a heating roll 8 and a pressure roll 9 to form a flat surface. A thermoplastic resin layer 10 is formed on the base sheet 1 by smoothing it. Note that FIG. 2 is an explanatory diagram showing a state in which the thermoplastic resin layer 10 is formed in a pattern on the base sheet 1.

The present invention has the following various effects due to the above configuration. In other words, it is possible to form a resin layer in a desired pattern on a base sheet as appropriate, and it is also possible to form a resin film that is difficult to form using conventional melt extrusion methods. By using a mixture of several resin powders, a mixed resin layer can be obtained, and its practical effects are great, such as low manufacturing costs.

Example 1 1 Base Sheet Mirror (12μ polyester film manufactured by Toray Industries, Inc.) 2 Adhesive resin solution ester resin #20 (Ester resin manufactured by Toyobo Co., Ltd.) 30 parts by weight Ethyl acetate 70 3 Thermoplastic resin Powdered Frozen UF-80 (manufactured by Steel Chemical Co., Ltd.)
Polyethylene powder (particle size: 10 to 50 μm) The adhesive resin is coated on the base sheet of 1 using the rotary screen printing method using the manufacturing method described above.
A film was coated to a thickness of 20 μm, and (3) polyethylene powder was sprinkled on the resin layer before the organic solvent in the resin layer was volatilized. The thickness of the scattering layer is approximately 10μ. This is 150
C. for 3 minutes, and then the surface was smoothed using a heated pressure roll.

The created pattern was as shown in FIG. 2, and the polyethylene coated area was heat-sealed using a technique such as heat sealing to form a bag shape. The advantage of this bag is that even for products such as oil-based foods, which would have oil resistance problems if the polyethylene film came into direct contact with them, the packaging bag using this method allows the polyester film surface to come into contact with the polyethylene film layer, and the polyethylene film layer is simply heat-sealed. Since it was formed only in the section, it did not cause any trouble and was extremely useful. The heat sealing strength of the sealed portion is 2 kg/15 mm, which is sufficient strength for a packaging bag.

Example 2 1 Base sheet/bleached kraft paper (manufactured by Kishu Paper Co., Ltd.)
70g/m ² ) 2 Adhesive resin solution Super Chron 803MW (chlorinated polypropylene manufactured by Sanyo Kokusaku Pulp Co., Ltd.) 20 parts by weight Toluene 80 〃 3 Thermoplastic resin powder Flowdex P-2 (Steel Chemical Co., Ltd.) Company-made
(Polypropylene powder with particle size of 20 to 100 μm) A polypropylene film was formed in a pattern in the same manner as in Example 1. The heating conditions were 170°C for 3 minutes. This was also made into a packaging bag, medical instruments such as absorbent cotton, a scalpel, and scissors were sealed and then sterilized using high-pressure steam at 121°C for 20 minutes. In this case as well, if there is a resin layer heat sealing agent on the entire surface of the base sheet, hygienic problems such as transfer to the contents may occur, but when the material according to the present invention is used, this There were no concerns at all, and there were no problems in extraction tests, etc. The heat seal strength of the heat seal part (polypropylene melt bonded part) is 2.
Kg/15mm, and no problems such as bag breakage occurred during high-pressure steam sterilization.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a process diagram of the present invention, and FIG. 2 is an explanatory diagram showing a state in which a thermoplastic resin layer is formed in a pattern on a base sheet. . 1...Base sheet, 2...Resin layer, 3...Hopper,
4... Thermoplastic resin powder, 5... Supply roll, 6... Vibrating sieve, 7... Air brush, 8... Heating roll, 9...
Pressure roll, 10... thermoplastic resin layer, A... printing section, B... heating oven.

Claims (1)

[Claims] 1. Form a resin layer in a desired shape on a base sheet such as a plastic sheet or paper using an adhesive resin solution, and adhere polyolefin resin powder onto the resin layer while the resin layer is adhesive. The thermoplastic resin powder is melted and fixed on a base sheet such as a plastic sheet, paper, etc. by heating and pressing between a heating roll and a pressure roll, and the surface thereof is smoothed. A method of forming a thermoplastic resin layer.