CN111284096B

CN111284096B - Polyamide film with improved printing composite effect and preparation method thereof

Info

Publication number: CN111284096B
Application number: CN201910818632.1A
Authority: CN
Inventors: 廖贵何; 陈曦; 郑伟; 贾露; 刘运锦; 林新土; 李智尧
Original assignee: Xiamen Changsu Industrial Co Ltd
Current assignee: Xiamen Changsu Industrial Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2021-11-26
Anticipated expiration: 2039-08-30
Also published as: CN111284096A

Abstract

The invention provides a polyamide film with improved printing composite effect and a preparation method thereof, wherein the polyamide film with improved printing composite effect comprises a three-layer composite film, and the film layer structure comprises an upper surface layer, a middle layer and a lower surface layer; the components of the upper surface layer comprise polyamide resin, an anti-blocking agent and a slipping agent; the components of the intermediate layer include a polyamide resin; the components of the lower surface layer comprise polyamide resin, an anti-blocking agent and a slipping agent; wherein, at least one layer of the upper surface layer and the lower surface layer is added with functional master batches. According to the polyamide film with the printing composite effect, the functional master batches are added on the surface layer, so that the functional master batches have the effect of improving the surface tension of the film, and the film can have excellent ink adhesion and interlayer adhesion in the printing and composite processes. Polyamide films with improved print lamination are of vital practical interest both for film manufacturers and downstream consumers of use.

Description

Polyamide film with improved printing composite effect and preparation method thereof

Technical Field

The invention relates to the field of flexible packaging film processing, in particular to a polyamide film with improved printing composite effect and a preparation method thereof.

Background

The biaxially oriented polyamide film (BOPA) has the characteristics of excellent puncture resistance, gas barrier property, mechanical property, optical property, oil resistance, chemical solvent resistance, electrical insulation property, wide temperature application range and the like, is widely applied to various fields such as food packaging, daily necessity packaging, electronic product packaging and the like, and becomes the third largest biaxially oriented film after BOPP and BOPET.

Generally, a biaxially oriented polyamide film is used not alone but after being subjected to secondary processing such as printing, coating, aluminum plating, and lamination, it is prepared into a bag and then used. In order to enable the film to be printed, coated, aluminized and laminated, a certain surface tension needs to be ensured on the surface of the film, and the problem that the printing effect is reduced, the adhesion of ink is insufficient, the lamination strength is low or delamination occurs due to too low surface tension. Therefore, in the process of producing a biaxially oriented polyamide film, surface treatment is required, and the surface treatment methods include corona treatment, flame treatment, plasma treatment, chemical oxidation treatment, and the like, and among them, the most common treatment method is corona treatment. The principle is that high-frequency high-voltage power supply is applied between a metal electrode and a corona treater and is subjected to corona discharge, so that surrounding air is ionized to produce O₃Meanwhile, high energy impacts the surface of the polyamide film, and under the combined action of the high energy and the high energy, chemical bonds on the surface of the polyamide film are broken and degraded, so that the surface roughness of the film is increased, and the surface tension is improved.

Therefore, in order to obtain higher surface tension, the corona treatment power can be increased only in the production process, and voltage and current overload is easily caused to damage equipment, so that the maintenance cost of the equipment is increased, and the production energy consumption is increased. Furthermore, increasing the surface tension by increasing the corona treatment power is not the most scientific and reasonable method for causing the properties of the polyamide film to be damaged to some extent, such as the film becoming brittle and the film aging being accelerated.

Therefore, how to improve the printing composite effect of the BOPA film becomes a problem to be solved in the production and use processes of the current biaxially oriented polyamide film.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a polyamide film with improved printing composite effect, which comprises a three-layer composite film, wherein the film layer structure comprises an upper surface layer, a middle layer and a lower surface layer;

the components of the upper surface layer comprise polyamide resin, an anti-blocking agent and a slipping agent; the components of the intermediate layer include a polyamide resin; the components of the lower surface layer comprise polyamide resin, an anti-blocking agent and a slipping agent;

wherein, at least one layer of the upper surface layer and the lower surface layer is added with functional master batches.

Further, the functional master batch comprises the following components in percentage by mass:

further, the surface tension enhancer is formed by the matched combination of an organic compound and a polymer.

Further, the organic compound is selected from one or more of dimethyl sulfoxide, sulfolane, ethylene nitrate, aniline, acetonitrile, nitromethane, zinc alcohol phosphate, trifluoroethyl methacrylate, dimethylformamide, benzoyl peroxide and 2-amino-2-methyl-1-propanol.

Further, the polymer is selected from one or more of polyethylene glycol, alpha-hydrogen-omega-hydroxyl (oxygen-1, 2-ethanediyl) polymer, polyester polyol, polyacrylonitrile, polyvinyl alcohol, polyethylene terephthalate, phenolic resin, urea resin, melamine formaldehyde resin, polyamide polyamine epichlorohydrin, amino resin and polyvinyl butyral.

Further, the compatilizer is selected from one or two of maleic anhydride grafted nylon 6 and glycidyl methacrylate grafted nylon 6.

Further, the dispersing agent is selected from one or a combination of several of PE wax, vinyl bis-stearamide, zinc stearate, calcium stearate and glyceride.

Further, the antioxidant is selected from the group consisting of hindered phenol antioxidants and phosphite antioxidants.

Further, the other auxiliary agent is selected from one or more of polyvinyl acetate, polyvinyl acetal, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, perchloro-ethylene resin, polyacrylate, terpene resin, modified rosin, C5 petroleum resin and C9 petroleum resin.

Further, the polyamide is selected from one or more of PA6 (nylon 6), PA66 (polyhexamethylene adipamide), PA6/PA66 copolymer (nylon 6/polyhexamethylene adipamide copolymer), MXD6 (m-phenylenediamine adipamide), PA46 (polytetramethyleneadipamide), PA1010 (pima adipamide), PA1212 (polydodecanoyldodecylamine), PA11 (polyundecanolactam) and PA12 (polydodecanolactam); PA6 (nylon 6) is preferred.

Further, the anti-blocking agent is one or more of alumina, magnesium carbonate, silicon dioxide, calcium carbonate, talcum powder, barium carbonate, diatomite, titanium dioxide and kaolin.

Further, the particle size (D50) of the anti-blocking agent is 1-10 μm.

Further, the slipping agent is composed of one or more of oleamide, erucamide, stearic acid amide, ethyl bis-stearamide, silicone oil and silicone powder.

Furthermore, the total thickness of the film is 10-40 μm, wherein the thickness of the upper surface layer and the lower surface layer is 1-4 μm, and the thickness of the middle layer is 2-38 μm.

The invention also provides a preparation method of the polyamide film with the improved printing composite effect, which comprises the following steps:

step one, putting all components of the functional master batch into a high-speed mixer according to a ratio, uniformly mixing for 5min, adding the mixed material into a double-screw extruder, carrying out melt extrusion, setting the temperature of the extruder at 245-280 ℃, and the rotating speed of the extruder at 300-500 r/min, cooling and dicing the material strips, and thus obtaining the functional master batch;

step two, drying all the raw materials, and controlling the moisture content of the raw materials to be below 800 ppm;

mixing the raw materials of the upper surface layer, the middle layer and the lower surface layer according to a formula ratio, then melting, plasticizing and extruding the mixture at the temperature of 230-270 ℃ through respective extruders, and flowing out through a coat hanger type die head;

step four, attaching the melt to a cold drum by using a low-pressure air knife to form a thick sheet, wherein the thickness of the thick sheet is 100-400 mu m, and the temperature of the cold drum is 10-45 ℃;

heating the thick sheet, and longitudinally stretching by using a Brukner step stretcher, wherein the stretching temperature is 45-65 ℃, the stretching is two-point stretching, and the stretching ratio is 1.5-1.8 x 1.5-1.8;

sixthly, transversely stretching the longitudinally stretched film, wherein the stretching temperature is 80-150 ℃, and the stretching ratio is 3.0-3.5;

seventhly, performing heat setting treatment on the stretched film, wherein the setting temperature is 170-220 ℃, and the setting time is 5-50 s; then cooling and corona treatment are carried out on the film, wherein the corona treatment power is 8-15 Wmin/m²The biaxially oriented polyamide film with the improved printing composite effect is prepared, and the thickness of the film is 10-40 mu m.

The biaxially oriented polyamide film provided by the invention has the advantages that the printing composite effect is improved; by adding the functional master batch on the surface layer, the functional master batch has the effect of improving the surface tension of the film, and the film can have better ink adhesion and interlayer adhesion in the printing and compounding processes. The film is enabled to reach higher surface tension in the production process by the mode of reducing the corona power, the production energy consumption is reduced, the damage to equipment caused by the overlarge corona power is avoided, the maintenance cost of the equipment is reduced, and meanwhile, the influence of the high corona power on the performance of the film can be effectively avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a film structure of a polyamide film with improved printing composite effect according to the present invention.

Reference numerals:

1 upper layer 2 middle layer 3 lower layer

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. 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.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

It should be noted that the examples do not indicate specific techniques or conditions, and the reagents or apparatuses used are not indicated by manufacturers in the literature in the field or the specification of the product, and all of them are conventional products available on the market.

Example 1

A polyamide film with the effect of improving printing composite effect is a three-layer structure consisting of an upper surface layer 1, a middle layer 2 and a lower surface layer 3;

based on the mass percentage, the weight percentage of the mixture,

the upper surface layer 1 comprises 5% of functional master batch, 94.4% of polyamide resin, 0.3% of anti-blocking agent and 0.3% of slipping agent;

the middle layer 2 is 100% polyamide resin.

The lower surface layer 3 comprises 5% of functional master batch, 94.4% of polyamide resin, 0.3% of anti-blocking agent and 0.3% of slipping agent.

The functional master batch comprises the following components:

the ratio of the organic compound to the polymer in the surface tension improver in the functional master batch is 2: 1. the organic compounds are dimethylformamide and 2-amino-2-methyl-1-propanol in a ratio of 1: 1, mixing the components, wherein the polymer is polyester polyol, polyacrylonitrile and polyvinyl alcohol, and the weight ratio of the polyester polyol to the polyacrylonitrile to the polyvinyl alcohol is 1: 1: 1 and mixing.

The thicknesses of the upper surface layer 1 and the lower surface layer 3 are respectively 2 μm and 2 μm, and the total thickness of the film is 15 μm.

The preparation method of the polyamide film with the improved printing composite effect comprises the following steps:

step one, putting all components of the functional master batch into a high-speed mixer according to the proportion, uniformly mixing for 5min, adding the mixed auxiliary agent into a double-screw extruder, melting and extruding, setting the temperature of the extruder at 265 ℃, and the rotating speed of the extruder at 400r/min, cooling and dicing the material strips, and obtaining the functional master batch.

And step two, drying all the raw materials, and controlling the moisture content of the raw materials to be below 800 ppm.

And step three, mixing the raw materials of the upper surface layer 1, the middle layer 2 and the lower surface layer 3 according to a formula ratio, melting, plasticizing and extruding the mixture at the temperature of 255 ℃ through respective extruders, and flowing out through a coat hanger type die head.

And step four, attaching the melt to a cold drum by using a low-pressure air knife to form a thick sheet, wherein the thickness of the thick sheet is 180 mu m, and the temperature of the cold drum is 25 ℃.

And step five, heating the thick sheet, and longitudinally stretching the thick sheet by using a Brukner step stretcher, wherein the stretching temperature is 55 ℃, the stretching is two-point stretching, and the stretching ratio is 1.7 x 1.7.

And step six, transversely stretching the longitudinally stretched film, wherein the stretching temperature is 120 ℃, and the stretching ratio is 3.4.

Seventhly, performing heat setting treatment on the stretched film, wherein the setting temperature is 210 ℃, the setting time is 20s, then performing cooling and corona treatment on the film, and the corona treatment power is 13Wmin/m²The corona-treated surface was the upper surface layer 1 (for convenience of result recording, the upper surface layer 1 is marked with "inner" and the lower surface layer 2 is marked with "outer", the same applies below), and the biaxially oriented polyamide film having improved printing lamination effect was finally obtained, and the film thickness was 15 μm.

Example 2

based on the mass percentage, the weight percentage of the mixture,

the upper surface layer 1 comprises 10 percent of functional master batch, 89.4 percent of polyamide resin, 0.3 percent of anti-blocking agent and 0.3 percent of slipping agent;

the middle layer 2 is 100% of polyamide resin;

the lower surface layer 3 comprises 10% of functional master batch, 89.4% of polyamide resin, 0.3% of anti-blocking agent and 0.3% of slipping agent.

The functional master batch comprises the following components:

The preparation of the polyamide film having an improved print lamination effect was the same as the production method of example 1.

Example 3

based on the mass percentage, the weight percentage of the mixture,

the upper surface layer 1 comprises 15 percent of functional master batch, 84.4 percent of polyamide resin, 0.3 percent of anti-blocking agent and 0.3 percent of slipping agent;

the middle layer 2 is 100% of polyamide resin;

the lower surface layer 3 comprises 15% of functional master batch, 84.4% of polyamide resin, 0.3% of anti-blocking agent and 0.3% of slipping agent.

The functional master batch comprises the following components:

Example 4

based on the mass percentage, the weight percentage of the mixture,

the upper surface layer 1 comprises 10% of functional master batch, 89.4% of polyamide resin, 0.3% of anti-blocking agent and 0.3% of slipping agent;

the middle layer 2 is 100% of polyamide resin;

The functional master batch comprises the following components:

Seventhly, performing heat setting treatment on the stretched film, wherein the setting temperature is 210 ℃, the setting time is 20s, then performing cooling and corona treatment on the film, and the corona treatment power is 8Wmin/m²The corona treatment surface is an upper surface layer 1, and the biaxially oriented polyamide film with the improved printing composite effect is finally obtained, wherein the thickness of the film is 15 microns.

Example 5

based on the mass percentage, the weight percentage of the mixture,

the middle layer 2 is 100% of polyamide resin;

The functional master batch comprises the following components:

the ratio of the organic compound to the polymer in the surface tension improver in the functional master batch is 1: 1. the organic compounds are dimethylformamide and 2-amino-2-methyl-1-propanol in a ratio of 1: 1, mixing the components, wherein the polymer is polyester polyol, polyacrylonitrile and polyvinyl alcohol, and the weight ratio of the polyester polyol to the polyacrylonitrile to the polyvinyl alcohol is 1: 1: 1 and mixing.

The polyamide film having an improved print lamination effect was prepared in the same manner as in example 4.

Comparative example 1

The polyamide film is a three-layer structure consisting of an upper surface layer 1, a middle layer 2 and a lower surface layer 3;

based on the mass percentage, the weight percentage of the mixture,

the upper surface layer 1 comprises 99.4 percent of polyamide resin, 0.3 percent of antiblocking agent and 0.3 percent of slipping agent;

the middle layer 2 is 100 percent of polyamide resin

The lower skin layer 3 comprises 99.4% of polyamide resin, 0.3% of antiblocking agent and 0.3% of slipping agent.

Since the functional base particles were not added in the preparation of the polyamide film, the processing step of the functional base particles was omitted, and the preparation method was the same as that of example 1.

Comparative example 2

based on the mass percentage, the weight percentage of the mixture,

the middle layer 2 is 100% polyamide resin.

Since the functional base particles were not added in the preparation of the polyamide film, the processing step of the functional base particles was omitted, and the preparation method was the same as that of example 4.

Comparative example 3

based on the mass percentage, the weight percentage of the mixture,

the upper skin layer 1 comprises 99.4% of polyamide resin, 0.3% of antiblocking agent and 0.3% of slipping agent.

The middle layer 2 is 100% polyamide resin.

The preparation method of the polyamide film comprises the following steps:

the first step is as follows: drying all the raw materials, and controlling the moisture content of the raw materials to be below 800 ppm.

The second step is that: the raw materials of the surface layer 1, the surface layer 2 and the middle layer are respectively mixed according to the formula proportion, then are melted, plasticized and extruded at the temperature of 255 ℃ through respective extruders, and flow out through a coat hanger type die head.

The third step: and attaching the melt to a cold drum by using a low-pressure air knife to form a thick sheet, wherein the thickness of the thick sheet is 180 mu m, and the temperature of the cold drum is 25 ℃.

The fourth step: heating the thick sheet, and longitudinally stretching by using a Brukner step stretcher, wherein the stretching temperature is 55 ℃, the stretching is two-point stretching, and the stretching ratio is 1.7 x 1.7.

The fifth step: and transversely stretching the longitudinally stretched film, wherein the stretching temperature is 120 ℃, and the stretching ratio is 3.4.

And a sixth step: heat setting the stretched film at 210 deg.c for 20 sec, cooling and corona treatment at 15Wmin/m²The corona treatment surface is an upper surface layer 1, and the biaxially oriented polyamide film with the improved printing composite effect is finally obtained, wherein the thickness of the film is 15 microns.

Comparative example 4

based on the mass percentage, the weight percentage of the mixture,

the middle layer 2 is 100% of polyamide resin;

The functional master batch comprises the following components:

the organic compounds are dimethylformamide and 2-amino-2-methyl-1-propanol in a ratio of 1: 1 and mixing.

Comparative example 5

based on the mass percentage, the weight percentage of the mixture,

the middle layer 2 is 100% of polyamide resin;

The functional master batch comprises the following components:

the polymer is polyester polyol, polyacrylonitrile and polyvinyl alcohol, and the weight ratio of the polyester polyol to the polyacrylonitrile to the polyvinyl alcohol is 1: 1: 1 and mixing.

The present invention tests the relevant performance of the above examples and comparative examples, and the specific result data is shown in table 1.

TABLE 1

Wherein the surface tension is measured according to the requirements of GB/T14216-2008 'determination of wetting tension of plastic film and sheet', and the surface tension of the inner surface and the outer surface of the thin film is measured; the tensile strength was measured according to the requirements of GB/T1040.3-2006 "determination of tensile Properties of plastics (part 3: test conditions for films and sheets)", and the tensile strength of the films was tested; the composite peel force is measured according to the requirements of GB8808 Peel test method for Soft composite Plastic materials, the outer layer of the prepared film in each example and comparative example is compounded with PE film under the same conditions, and then the interlaminar peel force is measured according to the standard; the ink adhesion was evaluated by a tape tack/peel test, in which the inner layer of the film was first printed with ink under the same conditions, the tape was adhered to the ink, the tape was pressed flat by hand to be in close contact with the film, the film was then slowly peeled off, and the transfer of ink to the tape was observed. The composite peel force and ink adhesion were evaluated using the following grades:

as can be seen from table 1, compared with the biaxially oriented polyamide film produced by the conventional method, the biaxially oriented polyamide film with an improved printing composite effect produced by the present invention can effectively improve the surface tension of the film, so that the film has a better printing composite effect, and meanwhile, the mechanical properties are excellent, and the production energy consumption and the maintenance cost of the equipment are saved to a certain extent.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polyamide film with improved print lamination, characterized in that: the composite membrane comprises a three-layer composite membrane, wherein a membrane layer structure comprises an upper surface layer, a middle layer and a lower surface layer;

wherein, at least one layer of the upper surface layer and the lower surface layer is added with functional master batches;

the functional master batch comprises the following components in percentage by mass:

60-93.8% of polyamide resin

5 to 25 percent of surface tension improver

1-10% of compatilizer

0.1 to 1 percent of dispersant

0.1 to 1 percent of antioxidant

0% -3% of other auxiliary agents;

the surface tension enhancer is formed by the mutual matching combination of an organic compound and a polymer;

the organic compound is a combination of dimethylformamide and 2-amino-2-methyl-1-propanol;

the polymer is a combination of polyester polyol, polyacrylonitrile and polyvinyl alcohol.

2. The polyamide film with enhanced print couple effect of claim 1, wherein: the compatilizer is selected from one or two of maleic anhydride grafted nylon 6 and glycidyl methacrylate grafted nylon 6.

3. The polyamide film with enhanced print couple effect of claim 1, wherein: the dispersing agent is selected from one or a combination of more of PE wax, vinyl bis stearamide, zinc stearate, calcium stearate and glyceride.

4. The polyamide film with enhanced print couple effect of claim 1, wherein: the antioxidant is selected from the group consisting of hindered phenol antioxidants and phosphite antioxidants.

5. The polyamide film with enhanced print couple effect of claim 1, wherein: the other auxiliary agent is selected from one or more of polyvinyl acetate, polyvinyl acetal, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, perchloro-ethylene resin, polyacrylate, terpene resin, modified rosin, C5 petroleum resin and C9 petroleum resin.

6. A method for preparing a polyamide film with improved print compounding effect according to any one of claims 1 to 5, characterized by comprising the following steps:

seventhly, performing heat setting treatment on the stretched film, wherein the setting temperature is 170-220 ℃, and the setting time is 5-50 s; and then cooling and corona treatment are carried out on the film, wherein the corona treatment power is 8-15 Wmin/m, so that the biaxially oriented polyamide film with the printing composite effect improved is prepared, and the film thickness is 10-40 mu m.