JPS61228954A - Laminated biaxial oriented polypropylene 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 [Field of Industrial Application] The present invention relates to a laminated polypropylene film with excellent adhesive properties.

[Conventional technology]

Conventionally, a laminated biaxially stretched polypropylene film is known in which a layer of a copolymer mainly composed of ethylene is formed as an adhesive layer on a biaxially stretched polypropylene film.

[Problem that the invention attempts to solve]

However, although such conventional laminated biaxially oriented polypropylene films have excellent adhesive properties, they have poor slip properties and #4 blocking properties, which poses a problem in handling the film.

The present invention is free from such drawbacks, viz.

It is an object of the present invention to provide a laminated biaxially stretched polypropylene film that has excellent slip properties, #1 blocking properties, and also excellent adhesive properties.

[Means for solving problems]

The present invention provides that at least one side of a biaxially oriented polypropylene film contains 60 to 95% by weight of ethylene, 5 to 40% by weight of one or more esters selected from acrylic esters and methacrylic esters, and maleic anhydride. Laminated biaxial stretching formed by forming a layer of a composition in which a copolymer with an acid content of 0 to 15% by weight is a mixture of a copolymer mainly composed of quantum rene, a tackifying resin, a wax, and inorganic particles. It is characterized by polypropylene film.

The biaxially stretched polypropylene film in the present invention is
Mainly composed of propylene (preferably propylene 80 wt or more) and stretched in biaxial directions (preferably stretched by about 2 to 15 times in each of the longitudinal and lateral directions of the film)
It is what was done.

This film contains ethylene as a copolymer component.

Butene, etc., and polyethylene% as a mixed component,
The thickness of the biaxially stretched polypropylene film containing ethylene propylene copolymer, butene-propylene copolymer, etc. is not particularly limited, but is preferably 10 to 100 μm. In addition, for this biaxially stretched polypropylene film.

If necessary, films made of any composition may be laminated.

On the surface of the biaxially stretched polyglopylene film, the ethylene-based layer is formed.

Preferably, the material is subjected to sputtering, flame treatment, or corona discharge treatment.

In addition, the polypropylene film contains an antioxidant, an ultraviolet absorber, an antistatic agent, a coloring agent, and a lubricant.

Fillers, nucleating agents, etc. may be added as necessary.

In the present invention, one or more esters selected from acrylic esters and methacrylic esters (hereinafter simply referred to as ester A) have an ethylene content of 60 to 95
% by weight, acrylic acid and/or methacrylic acid ester content 5-40 wt, maleic anhydride content 0-15
It is a binary or tertiary copolymer whose main component is ethylene at t% by weight. On the right, in the case of a binary copolymer, the ethylene content is 70 to 88% by weight, and the quantal acid ester content is 12%.
-302 to 30% by weight is preferred.

For terpolymer, the ethylene content is 695-94.5
Preferably, the maleic anhydride content is 0.5 to 10% by weight, and the quantum lyric acid ester content is 5 to 30% by weight. &Right: As for copolymers, ternary copolymers are preferred over binary copolymers because they improve adhesion and side heat properties.

As for acrylic acid ester, which is a copolymerization component.

Ethyl acrylate, methyl acrylate, and methacrylate include ethyl methacrylate.

Examples include methyl methacrylate, propyl methacrylate, and butyl methacrylate.

This copolymer has a melt index (Jxs- of 67
30) is preferably 50 to 400, particularly preferably 80 to 300.

If the content of the copolymer component ester A is below the above range, the adhesive properties will be poor; if it is above the range,
Poor side heat properties or slipperiness.

The blocking resistance becomes poor.

Examples of the tackifying resin include rosin ester, rosin ester, hydrogenated rosin ester, terpene %, petroleum resin, etc., and preferably hydrogenated petroleum resin (preferably one with a hydrogenation ratio of 80 parts or higher). ), more preferably a cyclopentadiene hydrogenated petroleum resin.

The wax may be a low molecular weight polymer of synthetic resin such as polyethylene%, polypropylene%, poly(4-methylpentene-1) (although the molecular weight is not particularly limited).

200 to 6000), paraffin wax,
Microcrystalline wax, Fuisin-yaat n
Tup wax, slack wax.

Animal and plant waxes (for example, carnauba wax, etc.) may be used, and microcrystalline wax and fischertrotubus wax are preferred.

Paraffin wax, carnauba wax, and microcrystalline wax are particularly preferred.

As inorganic particles, silica, thyroid, kaolinite, zeolite, synthetic zeolite, clay, titanium oxide, calcium carbonate, etc. are used.
C median diameter) is 0.1 to zOμ, preferably 0
．． It is 2 to 5.0μ.

The layer formed on at least one side of the biaxially stretched polypropylene film of the present invention includes the above-mentioned ethylene-based copolymer (A), tackifying resin (B), wax (C), and inorganic particles. CD) is a mixed composition,
The mixing ratio is not particularly limited, but A:B:C:D 20
~60:10~50:10~60:0.1~3.0. Especially A:B:C: ]) -20~60:15~40:20~
50:0.1 to 6.0 is preferable, and within this range, adhesiveness, slipperiness, and strong blocking properties will be excellent.

A known antioxidant is added to this mixed composition.・
This is preferable, and the appropriate amount of addition is 0.01 to 1.0 weight molecules. Hindered phenol derivatives, polymerized products thereof, thiodiglobionic acid esters, and the like are often used. Specific examples of antioxidants include 0, for example.

■ Dibutylhuman tetraxytoluene (B, H, T)■
Tetrakis [methylene-5 (5,5 ditertiary butyl 4-hydroxyphenyl) propionate] Methylene ■ Tetrakis (2,4 ditertiary butyl phenyl) 4.4 biphenylenedi7 osphonite ■ 2.6 ditertiary butyl-alpha dimethyl Examples include aminovalacresol.

In addition, UV absorbers such as puenzophenone and benzotriazole and antistatic agents are added as necessary.

Colorants, lubricants, fillers, antifungal agents, and the like may be added depending on the purpose.

Next, the manufacturing method of the laminated film of the present invention will be explained.

First, a uniaxially stretched polypropylene film is prepared by a known method and coated with the mixed composition of the present invention at 120 to 220°C.

The viscosity (JAI7) of the mixed composition is 25 to 300.
00 centivoise, more preferably 25 to 5000 centivoise.

Coating methods include 1 commonly used coating methods, such as roll coaters such as rondo, gravure, and reverse;
A seven-mountain coater, a slit tie coater, a web coater, etc. can be used. Immediately after heating the mixed composition, it is preferable to cool it to below 70°C (preferably below the melting point of the composition). Are suitable).

The coated uniaxially stretched film of the 9 compositions was then stretched in a direction perpendicular to the stretching direction to form a laminated biaxially stretched polypropylene film.

[Measurement method and evaluation criteria of characteristics]

The measurement method and evaluation criteria of the present invention are as follows.

(1) Heat sealing force Adhesion evaluation method: The adhesive strength (g/m) between hot plates at 100° C. was high, indicating good adhesiveness.

(2) Paper adhesion In the adhesive evaluation method, the printed paper and the adhesive surface are stacked at 110°C.
Pressure bonding was performed using a heated roll, and the peeling force was measured. The larger the value, the better the adhesiveness.

(3) Slip coefficient: Two specimens kept moist for 24 hours in a room with a sliding coefficient of 20°C and 65% RH are stacked on opposite sides, and a load of 200g is placed on top of the two specimens. The resistance value was read by moving it at a speed of 200g and expressed as a calculated value of resistance value (g)/200g.

(4) Floraking shear force (evaluation of blocking ability) Sample films with a width of 3 em x length of 10 clI were stacked over 4 lengths and exposed at a load of 40 g/am in an atmosphere of 40°C and 80% RH for 24 hours. I regret leaving it alone.

Measure the force required for shear peeling using a tensile tester. The smaller the number, the better the reward blocking ability.

〔Example〕

Next, nine embodiments of the present invention will be described based on Examples.

Examples 1-3. Comparative Examples 1 to 3 +111 1.5 (g/l 0 min) of polypropylene was supplied to one extruder, melted at 280°C, extruded from 9 nozzles, and cooled by contact with a chill roll at 40°C.

The film was stretched 5 times in the longitudinal direction at 120°C to obtain a 180P -axis stretched film. One side of this -axially stretched film was hot-melt coated with the following composition at 150°C using a forward rotating roll coater.1. ．． 10 times perpendicular (
The film was stretched in the transverse direction and heat-set at 155° C. for 5 chills. A biaxially stretched polypropylene film having a coating thickness of 2μ and a thickness of 20μ was obtained (Example 1).

Ethylene methyl methacrylate copolymer (23 weight molecules of methyl methacrylate, MI 180g 710 minutes): 4o
, cyclopentadiene hydrogenated petroleum resin: 25% by weight, microcrystalline wax: 54.3% by weight, silica: 0.4% by weight, BHT2: 0.3% by weight.

Examples 2 to 6 and Comparative Examples 1 to 6 are all the same except that the hot melt composition shown in Example 1 was changed as shown in Table 1. The evaluation results are also shown in Table-1.

As can be seen from Table 1, Comparative Example 1 had poor adhesion because the copolymer contained less methacrylic ester. In Comparative Example 2, since no wax was added, hot melt application was difficult and uneven, and the laminated film also suffered from slippage, and the film that was wound up with blocking was torn during the first turn.

Comparative Example 3 uses an ethylene/vinyl acetate copolymer, which has poor side heating properties, resulting in uneven viscosity, uneven quality, and uneven application of hot melt.

Also, since there was little wax, the laminated film with increased wax content was prone to slipping and blocking. The characteristics also varied widely.

In Examples 1 to 3, the coating could be applied uniformly, and the laminated film had excellent slip properties and #4 blocking properties, so it was easy to handle during use, and it also had excellent adhesive properties. Therefore, it is suitable for heating, etc., such as overlapping packaging.

〔Effect of the invention〕

The present invention is a laminated biaxially oriented polypropylene film in which a layer of a specific mixed composition is formed on at least one side of the biaxially oriented polypropylene film, so that it has the advantage of having excellent adhesiveness, slipperiness, and repellent blocking property. It is something that plays.

Claims (1)

[Claims] (1) At least one side of the biaxially oriented polypropylene film has an ethylene content of 60 to 95% by weight, a content of one or more esters selected from acrylic esters and methacrylic esters of 5 to 40% by weight, and maleic anhydride. A laminated biaxially stretched polypropylene film formed by forming a layer of a composition in which a copolymer containing 0 to 15% by weight of ethylene as a main component, a tackifier resin, wax, and inorganic particles are mixed. .