JPS606456A - Manufacture of composite film - 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 The present invention relates to a method for producing a composite film having practically sufficient adhesive strength by laminating a nylon or polyester film treated with low temperature plasma and a polyolefin film by heating and pressing.

Conventionally, laminates of nylon or polyester films and polyolefin films have been known.

It is used in fields such as food packaging. In order to obtain these laminates, (1) a method of laminating nylon and polyolefin or a polyester film and a polyolefin film using an adhesive;

and ■ There is a method of laminating a nylon or polyester film subjected to corona discharge treatment and a polyolefin film by overlapping the treated surfaces and applying heat and pressure. Methods of using objects are also known.

However, in ■, the interlayer adhesion strength was insufficient.

In addition, since the method (2) uses an adhesive, it has the disadvantage that it requires time-consuming work such as applying the adhesive and laminating the process. In addition, although method (2) is considered to be theoretically effective, it is not possible to obtain a composite film with sufficient adhesive strength for practical purposes due to reasons such as deterioration of film strength when the corona discharge treatment conditions are strengthened. Not there,
It is only applied as an auxiliary means to improve adhesive strength in the production of composite films using adhesives.

The present invention was completed as a result of intensive studies to solve the above-mentioned problems, and provides a method for manufacturing a composite film with sufficient adhesive strength through simple steps.

Specifically, the present invention is a method for producing a composite film, which is characterized in that a nylon or polyester film subjected to low temperature plasma treatment and a polyolefin film subjected to low temperature plasma treatment are laminated by overlapping the treated surfaces and heating and pressurizing them. be.

As the nylon film, a 6-nylon film which is often used as a packaging material is suitable, and it is preferable to use a -axially or biaxially stretched film from the viewpoint of strength.

Similarly, a polyethylene terephthalate film is suitable as the polyester film, and from the viewpoint of strength, it is also preferable to use a -axially or biaxially stretched film.

3 The conditions for low-temperature plasma treatment are lXl0 ~ I T
orr oxygen, argon, nitrogen or helium gas,
Alternatively, the treatment time is set to be 1 second or more, preferably several seconds or more under conditions of a discharge value of 100 W or more in a mixed gas containing these. If the discharge value is lowered or the treatment time is shortened, the adhesive strength will decrease.

As the polyolefin film in the present invention.

Commercially available films such as polyethylene, polypropylene, and polybutene are sufficient, and can be appropriately selected and used depending on the purpose. In addition, these polyolefins include ethylene, propylene, butene, acrylic acid, methacrylic acid, iconic acid, fumaric acid, maleic acid,
A product obtained by copolymerizing or grafting an α,β-unsaturated carboxylic acid such as maleic anhydride, or a metal compound was further blended. There is no problem in using what is generally called an ionomer, and it contributes to improving the adhesive strength as long as it does not impair the physical properties of the film.

In the present invention, the heating and pressing conditions are from the softening temperature of polyolefin to below the melting temperature of nylon film or polyethylene terephthalate film, about 100°C or more for low density polyethylene and about 135°C or more for high density polyethylene.

For polypropylene, the temperature is about 160°C or higher. For nylon film, the temperature is 200 to 230°C or less, and for polyethylene terephthalate film, it is 250°C or less.

From an industrial standpoint, pressure is applied using a heating roller and a bank-up roller, with a linear pressure of 0.5 Kg/cm or more, preferably 2.
~10 Kg/cm.

At this time, it is advantageous to have the nylon film or polyethylene terephthalate film in contact with the addition Dt roller side and the polyolefin film in contact with the backup roller side, as this can prevent the easily softened polyolefin film from adhering to the roller surface. . The surface of the bank up roller is preferably treated with silicone resin or fluororesin so that it is heat resistant and difficult to adhere to.

After being laminated, the film is usually cooled with a cooling roller in contact with the nylon film or polyethylene terephthalate film, and then wound onto a take-up roller.

The present invention will be explained in more detail below using Examples and Comparative Examples.

Comparative example 1 Table 1 shows the adhesive strength of the laminate obtained by the conventional method.

Table 1 Structure Lamination method Adhesive strength g/15++m width N
y/PIE Coextrusion 5O Ny/pp Same as above 5O Ny/PE Adhesive used 400-500PET/PP
Same as above 400-500 The symbols in Table 1 are Nyi6-buylon, PET.

Polyethylene terephthalate, P [; polyethylene, P
Pi polypropylene.

The specific bonding method of the conventional laminate in Table 1 is Ny/
Co-extrusion of PE 6-1-(tff resin (manufactured by Toshi01, CM102)
1-
300F, melting point approximately 131°C) was heated and melted to 145°C and coextruded using a T-die method in a known manner.

Using polypropylene resin (Chisso (11) MF 600, melting point about 160°C) instead of Ny/ppO coextruded polyethylene resin,
The procedure was the same as the IJy/PH coextrusion except that the heating and melting temperature was 180°C.

Ny/PIE (adhesive used) 6-Nylon film (Unitika (manufactured by lit, product name emblem, 15μ) and PE film (70μ), 2
Corrugated urethane adhesive (80-980 manufactured by Toyo Morton)
8, 80-980B) at 100°C, and then aged at 40°C for 48 hours.

P-mouth T/PP (adhesive used) 6-Made a laminate in the same manner as Ny/PE except that PIET film (manufactured by Toshiku Ichikiku, trade name Lumirror P 41.12μ) was used instead of nylon film. Obtained.

Example 1 A nylon film (emblem, 15μ) and a polyethylene film (Tamabori [!J, DT-2 Commercial 3 product name, 70μ) were each subjected to low-temperature plasma treatment at 400W for 60 seconds in argon gas at 1 x 10 Torr. The treated surfaces were placed on top of each other at 170°C and with a linear pressure of 5
The adhesive strength of the composite film obtained by laminating under heat and pressure at kg/cm was 600 g/cm as measured by the 15 Tsuru IT type peeling method.

Comparative example 2 In Example 1, instead of low temperature plasma treatment.

A composite film obtained in the same manner except that it was passed through the film at a speed of 50 rn/min under the conditions of 70 to 80 KW and 4000 cycles/sec and subjected to corona discharge treatment had an adhesive strength of 50 g/am.

Comparative Example 3 A composite film obtained by heating and pressing a maleic acid grafted polyethylene film (70μ) with a graft ratio of about 5% on the corona discharge treated nylon film in Comparative Example 2 in the same manner had an adhesive strength of 120 g/cm. De Ah Puko.

Example 2 Table 2 shows the results of a test similar to Example 1 with different plasma treatment conditions.

Table 2 Atmospheric gas Vacuum degree Discharge value Time Adhesive strength Torr
W seconds g / 15+n l+2 Argon 2X10 450 50 4703 @ Element 2X10 500 30 600l Same as above 5X10 600 60 480 Nitrogen 5X
10 470 50 3803 Argon 2X10 400 40 420/Oxygen* *Approximately the same amount of mixed gas Example 3 Polyethylene terephthalate film (Lumirror P11
) and one side of the polyethylene film in Example 1, respectively.
Performed low temperature plasma treatment at 0W for 60 seconds.

By superimposing these treatments, 160°C1 linear pressure 5 kg
The adhesive strength of the composite film obtained by laminating by heating and pressurizing at /cm was 460 g as measured by the T-peel method in 15 fins.
/c+n.

Example 4 Polyethylene terephthalate film (Lumirror pH)
, and a polypropylene composition containing grafted polypropylene (manufactured by Toyo Ink Manufacturing Co., Ltd., trade name: Liosen M)
-1063-4) was subjected to the same low-temperature plasma treatment as in Example 3, heated and pressed at 180°C and a linear pressure of 5 kg/c+n, and laminated. The adhesive strength of the composite film obtained was 15 m1. The result of measurement using the is T-type peeling method was 500 g/am.

Patent Applicant Toyo Ink Mfg. Co., Ltd. Procedural Amendment (Spontaneous) August 37, 1981 Dear Commissioner of the Patent Office 1. Indication of the case 1980 Patent IM No. 114290 2. Name of the invention Manufacture of composite film Column 6 of "Detailed Description of the Invention" of the written description to correct ttf
Correct content: As per tlL (1) Specification, page 5, 10
Insert the following text between line 11 and line 11.

"The composite film obtained by the method of the present invention can be used as a packaging material in the food packaging field even as a two-layer film, but in order to give it so-called "stiffness" or to improve its barrier properties, More paper.

A method of bonding synthetic paper, aluminum foil, saponified ethylene-vinyl acetate monomer, polyvinylidene chloride, etc., with or without using a known adhesive.

It can also be used as a composite material with three or more layers depending on the coating method. Specifically, PET (low temperature plasma treatment)
/ (low temperature plasma treatment) PO / paper, I) ET (low temperature plasma treatment) / (low temperature plasma treatment) PO / adhesive / ethylene-Dl'! Saponified vinyl copolymer (or aluminum foil or paper) /PO (low temperature plasma treatment).

(Low temperature plasma treatment) PET (Low temperature plasma treatment)/
(Low-temperature plasma treatment) POZ paper/PO (low-temperature plasma treatment), etc., and a similar structure using nylon instead of PET can also be used. In addition, the above-mentioned PET represents polyethylene terephthalate, po represents polyolefin, and a urethane adhesive is usually used as the adhesive. ”

Claims (1)

[Claims] 1. A composite characterized in that a nylon or polyester film subjected to low-temperature plasma treatment and a polyolefin film subjected to low-temperature plasma treatment are layered by heating and pressurizing the treated surfaces of each other to form a 9MI layer. Film manufacturing method. 2. Low-temperature plasma treatment is performed in oxygen, argon, nitrogen, or helium gas, or a mixed gas containing these, at I X 10-3 to I Torr, under conditions of a discharge value of 100 W or more. A method for producing a composite film according to item 1.