KR20120121711A - Oriented Polypropylene Film and Composition for Adhesive Layer - Google Patents

Abstract

PURPOSE: A co-extrusion polypropylene film is provided to directly attach low-temperature resins such as polyethylene, ethylene vinyl acetate by heat and pressure without using aqueous or oily adhesive. CONSTITUTION: A co-extrusion polypropylene film comprises: a middle layer formed of a polypropylene resin; a surface layer(2) on the middle layer and formed of a composite resin or polypropylene resin; and an adhesive layer(3) under the middle layer and contacted to a substrate. The adhesive layer comprises: a polyolefin resin which is a homopolymer resin or copolymer resin of ethylene, propylene butene, octene, and of which melting point is 130 °C or less; an adhesion-reinforcing resin; and a processing aid.

Description

Oriented Polypropylene Film and Composition for Adhesive Layer

The present invention relates to a coextruded stretched polypropylene film, and more particularly, to a coextruded stretched polypropylene film and a composition for an adhesive layer that can be adhered to papers, metals or films with heat and pressure without adhesive treatment.

Generally, a film is laminated on a substrate such as paper, metal, film, etc. by applying an aqueous or oily adhesive to a stretched polypropylene film, and then passing it through a drying apparatus, in addition to a dry lamination method. There is a thermal lamination method of melting and bonding an adhesive resin.

The thermal lamination method is extruded and oxidized to a high temperature of about 300 ° C. with or without primer treatment on the stretched polypropylene film again to give polarity, and then pressed inline with other films and pressure rollers. After extruding lamination method and urethane-based or imine-based primer to laminate directly, melt-extruded low-temperature adhesive resin such as EVA at 220 ℃ using extruder, and then coating, forming, and thinly using T-die. After aging, the sheet is cut to a suitable size to be laminated off-line and passed through an extruded laminated film through a steam roll heated to about 95 to 100 ° C. using a separate laminator to melt only a low temperature thermal adhesive resin layer And thermal lamination methods for fusion and lamination.

Laminates such as book covers, shoes, shoes, cosmetic cases, calendars, shopping bags and posters are made by adhesive lamination and offline lamination. Adhesive lamination and adhesive Drying equipment is required to dry the most adhesives are not environmentally friendly, there is a possibility of poor quality due to the invasion of the printing surface by the residual solvent, and the water-based adhesives also have the disadvantage that can not be used in freezing cold.

On the other hand, the thermal lamination method can be thermally laminated offline, so that the installation space of the facility can be about 1/2, and the high-speed operation is possible, so there is almost no work loss, and the usage is gradually increasing. However, extrusion coating is applied to the stretched polypropylene (OPP) film. If the adhesion to the polyethylene and EVA resin is weak, there is a high risk of peeling, especially in the case of multiple folding case can drop the product value. In order to prevent this and improve adhesive strength, extrusion coating has been applied after application of the adhesive, but this has caused a decrease in productivity due to the process loss and the burden of raw material costs, and has problems of risk and environmental pollution due to the use of organic solvents.

Accordingly, the present invention has been made in order to solve the above problems, and in particular, in laminating films on substrates such as papers, metals, films, etc., even low-temperature resins such as polyethylene, EVA, etc. are used without using an aqueous or oily adhesive. It is to provide a composition for polyolefin coextruded stretched polypropylene film and an adhesive layer that can be directly bonded by heat and pressure without extrusion coating.

In order to solve the above technical problem, the present invention is a center layer (1) formed of a polypropylene resin; A surface layer (2) formed of a polypropylene resin or a composite resin for a matte film positioned on the center layer (1); And an adhesive layer (3) positioned below the central layer (1) and in contact with the substrate to be bonded, wherein the adhesive layer (A) has ethylene and propylene having a melting point of 130 ° C. or less. A polyolefin resin which is a homopolymer resin of butene, octene or a copolymer resin thereof, (B) adhesion reinforcing resin, and (C) a processing aid are provided.

In the coextruded stretched polypropylene film according to the present invention, the adhesive layer comprises 10 to 99% by weight of (A) polyolefin resin and 1 to 90% by weight of (B) adhesion reinforcing resin, wherein the component (A) resin and component (B) It is preferable to contain 0.05-10.0 weight part of (C) processing aids with respect to 100 weight% of mixtures of resin, More preferably, 50-90 weight% of (A) polyolefin resin and (B) which comprise the said contact bonding layer It contains 10-50 weight% of adhesion strengthening resins, and 0.05-10.0 weight part of (C) processing aids with respect to 100 weight% of mixtures of the said component (A) resin and a component (B) resin.

In addition, the adhesive layer preferably has a thickness in the range of about 5 to 50% of the total thickness of the coextruded polypropylene film.

In the coextruded stretched polypropylene film according to the present invention, the adhesion enhancing resin is an ethylene / vinylacetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / alkyl acrylate copolymer, an ethylene / methacrylic acid copolymer and a hot melt resin. It is preferable to select at least one kind from the group consisting of.

In the coextruded stretched polypropylene film according to the present invention, the processing aid is preferably one kind or a mixture of two or more kinds selected from antiblocking agents, antistatic agents and slip reinforcement agents.

The present invention also provides a homopolymer resin of ethylene, propylene, butene and octene having a melting point of 130 ° C. or lower, or 10 to 99% by weight of a polyolefin resin (A) and a copolymerization reinforcing resin (B) of 1 to 90% by weight. It provides a composition for the adhesive layer comprising a coextruded stretched polypropylene film comprising a (C) processing aid 0.05 to 10.0 parts by weight based on 100% by weight of the mixture of the component (A) resin and the component (B) resin. .

The coextruded stretched polypropylene film according to the present invention is directly adhered to the surface of substrates such as papers and metals by directly adhering with heat and pressure without adhesive treatment such as water-based adhesives, oil-based adhesives and EVA lamination when adhering with papers, metals and plastics. As it is heat bonded, it is used not only for the surface protection of book covers, calendars, shopping bags, posts, structures, etc., but also for various packaging, which can minimize process loss and reduce costs, and is effective in preventing risks and environmental pollution due to the use of organic solvents. .

1 is a cross-sectional view showing a cross-sectional structure of the stretched polypropylene film formed on one surface by co-extrusion of the adhesive layer according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to FIG. 1.

The present invention is a center layer (1) formed of a polypropylene resin; A surface layer (2) positioned above the center layer and formed of a composite resin for a polypropylene resin or a matte film; And an adhesive layer (3) positioned below the center layer and in contact with the substrate to be bonded, wherein the adhesive layer (3) comprises the following components (A), (B) and (C) It includes: (A) a polyolefin resin which is a homopolymer resin of ethylene, propylene, butene or octene having a melting point of 130 ° C. or less, or a copolymer resin thereof, (B) adhesion reinforcing resin, and (C) processing aid.

The center layer 1 is preferably formed of a polypropylene resin.

The surface layer 2 is preferably polypropylene having a relatively high melting point in the thermoplastic resin, and the polypropylene resin is a matte type commonly used to give a matting effect and a transparent type including a copolymer of propylene and at least one comonomer. It may comprise a matte type consisting of a composite resin composition for laminated film, the total thickness of the surface layer (2) is preferably laminated by co-extrusion to 5 to 50% of the total film thickness.

The adhesive layer 3 in contact with the substrate to be bonded includes components (A), (B) to (C).

The polyolefin resin of component (A) includes homopolymer resins of ethylene, propylene, butene or octene, as well as copolymer resins thereof, having a melting point of 130 ° C. or lower, preferably 50 to 120 ° C.

The adhesion enhancing resin of component (B) includes ethylene / vinylacetate copolymer, ethylene / acrylic acid copolymer, ethylene / alkyl acrylate copolymer, ethylene / methacrylic acid copolymer, hot melt resin, in addition to melting point for adhesion This low flowable resin can be used.

The said component (A) and (B) can be used individually or in mixture of 2 or more types, respectively, and can be used within the mixing range of a component (A) and a component (B).

The content of component (A) forming the adhesive layer 3 is 10 to 99% by weight, preferably 50 to 90% by weight, and the content of component (B) is 1 to 90% by weight, preferably 90 to 50. Weight percent. In this case, when the content of the component (A) is less than 10% by weight, the adhesive force with the central layer (1) may be weak and thus may be separated between layers, and the content of the component (A) is 100% by weight. It is preferable to mix and use a small amount of component (B) because the adhesive force with the base material to be said is weak.

In addition, the resin used for the adhesive layer 3 has a lower melting point than polypropylene, which may stick to the hot rolls during the stretching process, causing blocking or layer transition, and thus mixing the processing aid (C).

The processing aid (C) is added to modify the film surface for the purpose of anti-blocking, anti-static, slip reinforcement may be selected alone or two or more. Specifically, examples of the antiblocking agent include synthetic silica-based, organic PMMA-based, or silicone-based resins, and antistatic agents may include quaternary ammonium salts, alkyl amines, glycerol compounds, and the like. In addition, the slip agent used for the surface lubrication effect by reducing the friction coefficient may be used fatty acid amide, for example, erucamide, oleamide, steamide.

At this time, the content of the processing aid (C) is used within the range of 0.05 to 10.0 parts by weight based on 100% by weight of the mixture of the component (A) resin and the component (B) resin, and when the content is less than 0.05 parts by weight, Insignificant effects and exceeding 10.0 parts by weight adversely affect the optical properties of the entire film, which is undesirable. More preferable content of the processing aid (C) is 0.1 to 2.0 parts by weight.

The thickness of the adhesive layer 3 having the composition according to the invention is 5 to 70%, preferably 10 to 40% of the total film thickness. If the ratio of the adhesive layer 3 is low, adhesive force will become low, and if it is too high, a film will become soft too much and blocking will occur easily.

The film raw materials of the above configuration are coextruded through each extruder to produce a non-stretched sheet after cooling to 20 to 50 ° C. or cooling in water. The sheet may be stretched about 3 to 5 times in the longitudinally stretched region at about 90 to 140 ° C. and then stretched 7 to 8 times at the transversely stretched region at 100 to 180 ° C. to produce a coextruded film of 10 to 80 μm.

At this time, the polyolefin resin which is the homopolymer resin of ethylene, propylene, butene, or octene of these (A) melting | fusing point which comprises the adhesive layer 3 or less, or copolymers thereof, (B) adhesion strengthening resin, and (C) processing aid When a composition is provided, the composition is simply a mixture of Or it can be made of the adhesive layer 3 by masterbatch.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Comparative Example 1

The homopolypropylene (Korean emulsification) having a melt index (MI) of 2.0 g / 10 minutes was used as the center layer (1), and the homopolypropylene (Korean emulsification) having a melt index of 3.0 g / 10 minutes was used as the surface layer (2). In the adhesive layer 3, 0.2 parts by weight of silica-based antiblocking agent was added to 100% by weight of the olefinic plastomer having a melting point of 97 ° C. as a processing aid, and 240 ° C. was used to make the surface layer 10% and the adhesive layer 30% by using each extruder. Co-extruded with and cooled to 30 ℃ to prepare an unstretched sheet. The sheet was stretched about 4.5 times in the longitudinal stretch region of about 90 to 110 ° C., and then stretched 7 times in the transverse stretch region of 150 to 175 ° C. to produce a transparent OPP film of about 16 μm.

The film was cut to a suitable size and passed through the film through a steel roll heated to 120 ° C. using a separate paper machine offline to melt the adhesive layer, thereby preparing a laminate fused with paper. The film laminated | stacked on the paper was peeled off, and the peeling degree of paper and a film was measured.

Comparative Example 2

It is the same as that of the comparative example 1 except that the surface layer 2 was made into the matte composite resin masterbatch (Korean emulsification), and the thickness was 19 micrometers.

Example 1

The homopolypropylene (Korean emulsification) having a melt index (MI) of 2.0 g / 10 minutes was used as the center layer (1), and the homopolypropylene (Korean emulsification) having a melt index of 3.0 g / 10 minutes was used as the surface layer (2). The adhesive layer 3 was mixed with 80% by weight of an olefinic plastomer having a melting point of 97 ° C. and 20% by weight of an ethylene methyl acrylate copolymer having a melt index of 8 g / 10 minutes, and 0.2 part by weight of a silica blocking agent as a processing aid. Each extruder was used to coextrude at 240 ° C. to give 10% of the surface layer and 30% of the adhesive layer, and then to prepare a non-stretched sheet after cooling at 30 ° C. The sheet was stretched about 4.5 times in the longitudinal stretch region of about 90 to 110 ° C., and then stretched 7 times in the transverse stretch region of 150 to 175 ° C. to produce a transparent OPP film of about 16 μm.

The film was cut to a suitable size and passed through the film through a steel roll heated to 120 ° C. using a separate paper machine offline to melt the adhesive layer, thereby preparing a laminate fused with paper. The film laminated | stacked on the paper was peeled off, and the peeling degree of paper and a film was measured.

Example 2

It is the same as Example 1 except the surface layer 2 being a matte composite resin masterbatch (large emulsification) and having a thickness of 19 mu m.

Example 3

A homopolypropylene (Korean emulsification) having a melt index (MI) of 2.0 g / 10 minutes was used as the central layer (1), and a homopolypropylene (Korean emulsification) having a melt index of 3.0 g / 10 minutes was used as the surface layer (2). The adhesive layer 3 is mixed with 80% by weight of an olefinic plastomer having a melting point of 97 ° C. and 20% by weight of an ethylene acrylic acid copolymer having a melt index of 2 g / 10 minutes (190 ° C.) to form a silica blocking agent as a processing aid. The parts by weight were added and co-extruded to 240 ° C. to obtain 10% of the surface layer and 30% of the adhesive layer using each extruder, thereby cooling the sheet at 30 ° C., thereby preparing an unstretched sheet. The sheet was stretched about 4.5 times in the longitudinal stretch region of about 90 to 110 ° C., and then stretched 7 times in the transverse stretch region of 150 to 175 ° C. to produce a transparent OPP film of about 16 μm.

The film was cut to a suitable size and passed through the film through a steel roll heated to 120 ° C. using a separate paper machine offline to melt the adhesive layer, thereby preparing a laminate fused with paper. The film laminated | stacked on the paper was peeled off, and the peeling degree of paper and a film was measured.

Example 4

It is the same as Example 3 except having made the surface layer 2 into the matte composite resin masterbatch (Korean emulsification), and made thickness 19 nm.

Example 5

A homopolypropylene (Korean emulsification) having a melt index (MI) of 2.0 g / 10 minutes was used as the center layer (1), and a homopolypropylene (Korean emulsification) having a melt index of 3.0 g / 10 minutes was used as the surface layer (2). (3) is a processing aid by mixing 80% by weight of an olefinic plastomer having a melting point of 97 ° C, 15% by weight of an ethylene methyl acrylate copolymer having a melt index of 2g / 10 minutes (190 ° C), and 5% by weight of a hot melt resin. 0.2 parts by weight of a silica-based anti-blocking agent was added and coextruded to 240 ° C. so as to have a surface layer of 10% and an adhesive layer of 30% by using each extruder, thereby cooling to 30 ° C., thereby preparing an unstretched sheet. The sheet was stretched about 4.5 times in the longitudinal stretch region of about 90 to 110 ° C., and then stretched 7 times in the transverse stretch region of 150 to 175 ° C. to produce a transparent OPP film of about 16 μm.

The film was cut to a suitable size and passed through the film through a steel roll heated to 120 ° C. using a separate paper machine offline to melt the adhesive layer, thereby preparing a laminate fused with paper. The film laminated | stacked on the paper was peeled off, and the peeling degree of paper and a film was measured.

Example 6

It is the same as that of Example 5 except the surface layer 2 being a matte composite resin masterbatch (large emulsification), and having thickness of 19 micrometers.

The physical properties of the films prepared by Comparative Examples 1 and 2 and Examples 1 to 6 are shown in Table 1.

Comparative Example
One Comparative Example
2 Example
One Example
2 Example 3 Example 4 Example
5 Example 6 Thickness (mic) 16 19 16 19 16 19 16 19 Haze (%) 3 75 3 75 2 75 3 75 Gloss (%) Surface layer 90 5 90 5 90 5 90 5 Coefficient of friction Surface layer 0.3 0.48 0.25 0.48 0.22 0.47 0.27 0.50 The tensile strength Machine direction 12 11 12 10 10 11 12 11 Elongation rate Machine direction 180 200 190 200 180 200 190 210 Paper Film / paper weak
adhesion weak
adhesion Good Good Good Good Good Good

Description of the Related Art [0002]
1: center layer
2: surface layer
3: Adhesive layer

Claims (9)

A center layer 1 formed of a polypropylene resin; A surface layer (2) positioned above the center layer (1) and formed of a composite resin for a polypropylene resin or a matte film; And an adhesive layer (3) positioned below the center layer (1) and in contact with the substrate to be bonded.
The adhesive layer comprises (A) a polyolefin resin which is a homopolymer resin of ethylene, propylene, butene, octene having a melting point of 130 ° C. or less, or a copolymer resin thereof, (B) adhesion reinforcing resin, and (C) a processing aid. Co-extruded stretched polypropylene film.
The method of claim 1,
The adhesive layer comprises 10 to 99% by weight of (A) polyolefin resin and 1 to 90% by weight of (B) adhesion strengthening resin, and (C) to 100% by weight of the mixture of component (A) resin and component (B) resin. Co-extruded stretched polypropylene film comprising 0.05 to 10.0% by weight of the processing aid.
The method of claim 2,
50 to 90% by weight of (A) polyolefin resin and 10 to 50% by weight of (B) adhesive reinforcing resin constituting the adhesive layer.
The method of claim 1,
The adhesion reinforcing resin is co-extruded, characterized in that at least one selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / alkyl acrylate copolymer, ethylene / methacrylic acid copolymer and hot melt resin Oriented polypropylene film.
The method of claim 1,
The adhesive layer is about the total thickness of the coextruded stretched polypropylene film. A coextruded stretched polypropylene film, having a thickness in the range of 5 to 70%.
The method of claim 1,
The processing aid (C) is a coextrusion stretched polypropylene film, characterized in that one or a mixture of two or more selected from antiblocking agents, antistatic agents, slip reinforcing agents.
10 to 99% by weight of a polyolefin resin (A) which is a homopolymer resin of ethylene, propylene, butene and octene or a copolymer resin thereof having a melting point of 130 ° C. or less and 1 to 90% by weight of an adhesion-reinforcing resin (B), The composition for adhesive layers (3) consisting of 0.05-10.0 weight part of (C) processing aids with respect to 100 weight% of mixtures of component (A) resin and component (B) resin.
The method of claim 7, wherein
The adhesion reinforcing resin for the adhesive layer (3) consisting of at least one of the group consisting of ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / alkyl acrylate copolymer, ethylene / methacrylic acid copolymer and hot melt resin Composition.
The method of claim 7, wherein
The processing aid (C) is a composition for the adhesive layer (3) consisting of one kind or two or more kinds selected from an antiblocking agent, an antistatic agent and a slip reinforcement agent.

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