1. A fog-grinding type solvent-free environment-friendly hot-melt coating film is characterized in that: comprises a vision layer/core layer/bonding layer from outside to inside, wherein the raw materials of the vision layer comprise HDPE, ternary polymerization PP and amorphous micron-sized SiO₂The core layer comprises homopolymerized PP, a slipping agent and an antistatic agent, and the bonding layer comprises EVA, amino grafted PP, octene and PMMA.

2. The frosted solvent-free environment-friendly hot-melt laminated film as claimed in claim 1, wherein: by mass ratio, visual layer: core layer: adhesive layer = (15-35): (40-65): (10-30).

3. The frosted solvent-free environment-friendly hot-melt laminated film as claimed in claim 1, wherein: the raw materials of the visual layer comprise the following components in percentage by mass: 25-50wt% of HDPE, 50-75wt% of ternary copolymer PP and amorphous micron-sized SiO₂ 2-5wt%, and the sum of the total mass fractions is 100%.

4. The frosted solvent-free environment-friendly hot-melt laminated film as claimed in claim 1, wherein: the core layer comprises the following raw materials in parts by mass: 88 to 100 weight percent of homopolymerized PP, 2.5 to 6.5 weight percent of slipping agent, 1.5 to 5.5 weight percent of antistatic agent, and the sum of the total mass fractions is 100 percent.

5. The frosted solvent-free environment-friendly hot-melt laminated film as claimed in claim 1, wherein: the adhesive layer comprises, by mass, 45-70wt% of EVA, 20-55wt% of amino grafted PP, 5-20wt% of octene, and 78-5 wt% of PMMA2, wherein the sum of the total mass fraction is 100%.

6. The preparation method of the frosted solvent-free environment-friendly hot cladding film as claimed in any one of claims 1 to 5, wherein: the method comprises the following steps:

(1) plasticizing the formula mixture of each layer by using a three-layer co-extrusion casting extruder, and laminating the three layers together through a co-extrusion die head;

(2) film casting, wherein the speed of a casting roller is 2.0-5.0 m/min;

(3) casting, cooling and forming;

(4) film drawing and corona treatment;

(5) rolling the film;

(6) and (5) cutting edges and rolling to form a film.

7. The method of claim 6, wherein: in the plasticizing process in the step (1), the plasticizing temperature of the visual layer and the adhesion layer is 225-245 ℃, and the plasticizing temperature of the core layer is 230-250 ℃.

8. The method of claim 6, wherein: and (3) cooling to 32-40 ℃.

9. The method of claim 6, wherein: and (4) the speed of the traction roller is 2.1-5.1 m/min.

10. The method of claim 6, wherein: and (5) 2.0-4.0 kg of tension of the wind-up roll.

Background

The surface of paper products such as books and periodicals, handbags, paper packaging boxes, advertising materials and the like is covered with a layer of film, so that the functions of preventing a printing layer from scratching, preventing water and dust, improving the visual effect and grade of the products and the like can be achieved, the covering film mainly has high transparency and matte effect, the high-transparency film has high light transmittance, the surface of the products coated with the film can have high glossiness, the matte film has low transparency and high haze, and the coated products visually give people a soft comfortable feeling. The prime coat adhesive type pre-coating film is mostly applied in the market at present, but because the main component of a pre-coating film substrate film is polypropylene and the adhesion fastness between the pre-coating film substrate film and the adhesive layer EVA is poor, a layer of prime coat adhesive with an organic solvent needs to be coated on the surface of the substrate film in the production process of the pre-coating film so as to improve the fastness between the EVA and the substrate film, so the process can not only pollute the environment, but also consume a large amount of energy because the adhesive needs to be dried, and is a great bottleneck in the development of the pre-coating film.

Disclosure of Invention

The invention aims to provide a frosted solvent-free environment-friendly hot-melt laminating film and a preparation method thereof. The fog-grinding type solvent-free environment-friendly hot-melt cladding film is developed, and has the structure of a visual layer/a core layer/an adhesive layer: HDPE + amorphous SiO₂+ terpolymer PP/homopolymerized PP + additive/EVA + modified PP + octene + PMMA. The visual layer forms a comfortable fog grinding effect, the adhesive layer can be directly combined with paper without being coated with an adhesive, the reduction of the film structure is realized, the plastic consumption is reduced, the solvent pollution is reduced, and the production efficiency is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

a fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). By mass ratio, visual layer: core: adhesive layer ═ (15-35): (40-65): (10-30).

Further, the visual layer is made of HDPE, terpolymer polypropylene and amorphous micron-sized SiO₂Forming a multi-element composite system.

Further, the formula proportion of the visual layer is as follows: 25-50wt% of HDPE, 50-75wt% of ternary copolymer PP and amorphous micron-sized SiO₂2-5wt%, and the sum of the total mass fractions is 100%.

Furthermore, the core layer is a multi-element composite system consisting of homopolymerized polypropylene, a slipping agent and an antistatic agent.

Further, the formula proportion of the core layer is as follows: 88 to 100 weight percent of homopolymerized PP, 2.5 to 6.5 weight percent of slipping agent, 1.5 to 5.5 weight percent of antistatic agent, and the sum of the total mass fractions is 100 percent.

Furthermore, the bonding layer is a multi-element composite system consisting of EVA + amino grafted PP + octene + polymethyl methacrylate PMMA.

Further, the formula proportion of the bonding layer is as follows: 45-70wt% of EVA, 20-55wt% of amino grafted PP, 5-20wt% of octene, and 2-5wt% of PMMA, wherein the total mass fraction is 100%.

The visual layer of the invention adopts a combined extinction mode to realize the frosting and polishing effect of the visual layer. Firstly, blending HDPE and ternary polymerization PP, wherein the HDPE and the ternary polymerization PP belong to different substances, and the melt flowability of the HDPE and the ternary polymerization PP is different, so that the HDPE and the ternary polymerization PP are extruded by a screw in an extruder to be mixed at a high speed after being melted, and form a rugged surface due to the fact that the flowability of the HDPE and the ternary polymerization PP is different and in a turbulent state on the surface, light is diffusely reflected on the surface, and a soft and comfortable feeling is provided for people; second, amorphous SiO is added₂To the visual layer, amorphous SiO₂The particle size is controlled to be 3-5 microns, so that the transmission of light rays is blocked, the transparency of the film is reduced, and meanwhile, the film can be used as an anti-adhesion agent to be matched with a slipping agent, so that the adhesion between the visual layer and the adhesion layer during rewinding is reduced.

The adhesive layer is realized by taking hot-melt material EVA as a main body and modified polypropylene (amino grafted polypropylene), octene and tackifier polymethyl methacrylate (PMMA) as auxiliary materials. EVA melting point is low, and the stickness is strong, has excellent melting adhesion performance, but EVA and polypropylene polarity are different incompatible, extrude the complex simultaneously through three-layer crowded curtain coating processing technology altogether with polypropylene, appear glutinous roller, layering phenomenon easily, need adjust its processing adaptability, processing viscosity etc. through adding amino grafting modified polypropylene at the adhesion layer and solve. The polarity of polypropylene is improved after amino grafting modification, good compatibility is formed between the polypropylene and EVA, the processing viscosity of EVA can be adjusted, the EVA three-layer co-extrusion processing adaptability is improved, the adhesion capability of EVA and core layer polypropylene is improved, meanwhile, a polypropylene side chain is connected into an amino group, the amino group and hydroxyl groups carried by a large number of fibers on the surface of paper material have hydrophilicity, the combination of hydrogen bonds is easily formed, the adhesive force of an adhesive layer is enhanced, a small amount of PMMA is added, and the adhesion strength of the adhesive layer and the paper material can be improved due to the fact that the PMMA has a large branched chain and the viscosity is high.

According to the invention, a small amount of octene is added to the adhesive layer to enhance the adhesion between the adhesive layer EVA and the core layer homopolymerized PP. The octene contains ethylene and propylene functional groups, is compatible with the EVA containing the ethylene functional groups and the PP containing the propylene functional groups at the same time, and plays a role in connecting the PP of the core layer with the EVA of the adhesive layer, so that the core layer and the adhesive layer are firmly adhered without delamination.

The invention has the beneficial effects that:

the invention realizes the comfortable grinding and fogging effect of the film by matching a combined extinction mode: by utilizing the fluidity difference between HDPE and polypropylene, a micro-rough surface is formed on the surface, so that the light is diffused; micron-sized amorphous silica is added to the optical layer to block the transmission of light. The combined extinction forms the frosting effect.

The adhesive layer of the grinded mist type solvent-free environment-friendly hot cladding composite film developed by three-layer co-extrusion casting compounding is directly provided with a hot melting material taking EVA as a main body, and the adhesive layer can be directly hot-pressed and coated on the surface of paper without additional coating of the adhesive layer, so that the secondary processing procedure of the adhesive layer is reduced, the film structure is reduced, the plastic consumption is reduced, the energy is saved, and the production efficiency of an enterprise is greatly improved.

Adding partial octene in the bonding layer, connecting the bonding layer EVA with the core layer PP, adding amino grafted polypropylene in the bonding layer, adjusting EVA processing viscosity, improving EVA processing adaptability, enhancing EVA and PP composite firmness, forming hydrogen bond combination with paper material fiber hydroxyl, and enhancing adhesive force of the bonding layer on the surface of the paper material. The coordination of octene and amino grafted polypropylene enhances the compatibility of the adhesive layer and the core layer and the adhesion of the paper.

Drawings

FIG. 1 is a diagram of a frosted solvent-free environment-friendly thermal cladding film according to the present invention;

in the figure: 1-visual layer, 2-core layer, 3-adhesive layer.

Detailed Description

In order to facilitate understanding of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

1) Principal material

HDPE, Mount-mountain petrochemical Co., Ltd., China oil and gas;

terpolymerization of PP, beijing yanshan petrochemical company;

amorphous silica, Hangzhou Wanjing high and new materials Co., Ltd;

homo PP, North Beijing Yanshan petrochemical company;

octene, exxon, usa;

slipping agent, Chengdu Koghui Co., Ltd;

antistatic agents, Chengdu Koghui Co., Ltd;

amino grafted PP, beijing yanshan petrochemical company;

EVA, mitsui japan;

PMMA, mitsui japan;

2) main apparatus and instrument

A film casting experiment production line, Guangzhou general same instrument and equipment Co., Ltd;

a light transmittance haze meter, Shanghai precision scientific instruments, Inc.;

dart impact tester, denland electro-mechanical technologies, ltd;

an intelligent tensile testing machine, denland mechanical and electrical technology ltd;

3) test method

(1) Determination of tensile Strength

The method is carried out according to a GB/T1040.3-2006 test method, the stretching speed (no load) is (250 +/-50) mm/min, and the sample adopts an IV type (long strip); 160mm (length) × 15mm (width), gauge length 50 mm.

(2) Transmittance/haze measurement

According to the test method of the light transmittance of the transparent plastic GB/T2410-2008.

(3) Dart impact mass measurement

Test method QB/T9639.1-2008.

(4) Firm adhesion between the core layer and the adhesive layer, no delamination, and measurement of peel strength between the core layer and the adhesive layer

The test was carried out according to GB/T27740-2011.

Example 1

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). 15 wt% of visual layer, 55wt% of core layer and 30 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 27 wt% of HDPE, 70wt% of ternary copolymer PP and amorphous micron-sized SiO₂3 wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 95 wt% of homopolymerized PP, 3 wt% of slipping agent and 2 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the adhesive layer is: 60 wt% of EVA, 32 wt% of amino grafted PP, 5wt% of octene, 3 wt% of PMMA, and the sum of the total mass fractions is 100%.

The frosted solvent-free environment-friendly hot-melt laminating film and the preparation method thereof comprise the following steps:

(1) plasticizing the formula mixture of each layer by using a three-layer co-extrusion casting extruder, laminating the three layers together by using a co-extrusion die head, wherein the plasticizing temperature of the visual layer and the bonding layer is 230 ℃, and the plasticizing temperature of the core layer is 235 ℃;

(2) casting the film, wherein the speed of a casting roller is 2.0 m/min;

(3) casting, cooling and forming, wherein the cooling temperature is 32 ℃;

(4) film drawing, corona treatment and drawing roller speed of 2.1 m/min;

(5) winding the film, wherein the tension of a winding roller is 2.0 kg;

(6) and (5) cutting edges and rolling to form a film.

Example 2

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). 20wt% of visual layer, 50wt% of core layer and 30 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 28 wt% of HDPE, 68 wt% of ternary copolymer PP and amorphous micron-sized SiO₂4 wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 93.5 wt% of homopolymerized PP, 3.5 wt% of slipping agent and 3 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 59 wt% of EVA, 27.5 wt% of amino grafted PP, 10 wt% of octene, 3.5 wt% of PMMA3, and the sum of the total mass fractions is 100%.

The frosted solvent-free environment-friendly hot-melt laminating film and the preparation method thereof comprise the following steps:

(1) plasticizing the formula mixture of each layer by using a three-layer co-extrusion casting extruder, laminating the three layers together by using a co-extrusion die head, wherein the plasticizing temperature of the visual layer and the bonding layer is 235 ℃, and the plasticizing temperature of the core layer is 238 ℃;

(2) casting the film, wherein the speed of a casting roller is 2.2 m/min;

(3) casting, cooling and forming, wherein the cooling temperature is 35 ℃;

(4) film drawing, corona treatment and drawing roller speed of 2.3 m/min;

(5) winding the film, wherein the tension of a winding roller is 2.1 kg;

(6) and (5) cutting edges and rolling to form a film.

Example 3

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). 25 wt% of visual layer, 50wt% of core layer and 25 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 30 wt% of HDPE, 65 wt% of ternary copolymer PP and amorphous micron-sized SiO₂5wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 92.5 wt% of homopolymerized PP, 4 wt% of slipping agent and 3.5 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the adhesive layer is: 50wt% of EVA, 30 wt% of amino grafted PP, 15 wt% of octene, 5wt% of PMMA, and the sum of the total mass fractions is 100%.

The frosted solvent-free environment-friendly hot-melt laminating film and the preparation method thereof comprise the following steps:

(1) plasticizing the formula mixture of each layer by using a three-layer co-extrusion casting extruder, laminating the three layers together by using a co-extrusion die head, wherein the plasticizing temperature of the visual layer and the bonding layer is 240 ℃, and the plasticizing temperature of the core layer is 242 ℃;

(2) casting the film, wherein the speed of a casting roller is 2.3 m/min;

(3) casting, cooling and forming, wherein the cooling temperature is 40 ℃;

(4) film drawing, corona treatment and drawing roller speed of 2.4 m/min;

(5) winding the film, wherein the tension of a winding roller is 2.3 kg;

(6) and (5) cutting edges and rolling to form a film.

The performance parameters of the milled mist type solvent-free environment-friendly hot-melt laminated film prepared in the embodiments 1 to 3 are as follows:

from examples 1-3, it can be seen that the film property changes are influenced by the film formulation ratio changes, and especially as the octene content of the bonding layer increases, the tensile strength between the films increases, the bonding between the bonding layer and the core layer is firmer, and the peel strength increases. And with the visual layer, the SiO is in micron level₂The increase in the content decreases the gloss of the film and increases the haze.

Comparative example:

comparative example 1: (octene is too low, the bonding layer and the core layer are not firmly compounded and are easy to delaminate)

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂/(homo polypropylene + slip agent + antistatic agent)/(EVA + amino grafted PP + octene+ polymethylmethacrylate PMMA). 25 wt% of visual layer, 50wt% of core layer and 25 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 30 wt% of HDPE, 65 wt% of ternary copolymer PP and amorphous micron-sized SiO₂5wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 92.5 wt% of homopolymerized PP, 4 wt% of slipping agent and 3.5 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the adhesive layer is: EVA 62 wt%, amino grafted PP 30 wt%, octene 3 wt%, PMMA 5wt%, the total mass fraction is 100%.

When the octene content of the adhesive layer is 3%, the core layer and the adhesive layer are not firmly compounded after the film is formed, and the lamination is easy.

Comparative example 2: (too low content of amino grafted PP, unable to adjust the processing suitability of EVA)

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). 25 wt% of visual layer, 50wt% of core layer and 25 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 30 wt% of HDPE, 65 wt% of ternary copolymer PP and amorphous micron-sized SiO₂5wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 92.5 wt% of homopolymerized PP, 4 wt% of slipping agent and 3.5 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the adhesive layer is: 70wt% of EVA, 10% of amino grafted PP, 15% of octene and 5% of PMMA, wherein the sum of the total mass fractions is 100%.

When the content of the amino grafted PP in the adhesive layer is 10%, the EVA viscosity of the functional layer is high, and the roll sticking phenomenon occurs.

Comparative example 3: (amorphous micron-sized SiO₂Too low, film hazeNot ideal enough effect)

A fog-grinding type solvent-free environment-friendly hot-melt coating film is structurally characterized in that a visual layer/a core layer/an adhesive layer from outside to inside: HDPE (high-density polyethylene), terpolymer polypropylene and amorphous micron-sized SiO (silicon dioxide)₂(homo-polypropylene + slip agent + antistatic agent)/(EVA + amino graft PP + octene + polymethylmethacrylate PMMA). 25 wt% of visual layer, 50wt% of core layer and 25 wt% of adhesive layer.

In this embodiment, the formula ratio of the visual layer is: 34 wt% of HDPE, 65 wt% of ternary copolymer PP and amorphous micron-sized SiO₂1 wt%, and the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the core layer is: 92.5 wt% of homopolymerized PP, 4 wt% of slipping agent and 3.5 wt% of antistatic agent, wherein the sum of the total mass fractions is 100%.

In this embodiment, the formula ratio of the adhesive layer is: 50wt% of EVA, 30 wt% of amino grafted PP, 15 wt% of octene and 5wt% of PMMA, and the sum of the total mass fractions is 100%.

When the visual layer is amorphous micron-sized SiO₂When the content is 1 wt%, the film has a gloss of 14.5% and a haze of 69%, and the haze effect of the film is not satisfactory.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.