CN118702987A - A gradient plastic film and preparation method thereof - Google Patents

Abstract

The present invention relates to the technical field of plastic films, and proposes a gradient plastic film and a preparation method thereof. The film comprises the following raw materials in parts by weight: 10-90 parts of ethylene-vinyl acetate copolymer, 10-90 parts of polyethylene, 3-5 parts of mildew inhibitor, 5-20 parts of modified mica powder, 3-5 parts of antistatic agent, and 4-6 parts of pigment; the modified mica powder is obtained by modifying carboxylated mica powder with titanium dioxide nanotubes. Through the above technical scheme, the problems of poor mildew resistance, corrosion resistance, and mechanical properties of plastic films in the related art are solved.

Description

A gradient plastic film and preparation method thereof

Technical Field

The present invention relates to the technical field of plastic films, and in particular to a gradient plastic film and a preparation method thereof.

Background Art

Plastic film has been widely used in the production of raincoats, shower curtains and umbrellas due to its advantages such as lightness, flexibility and low cost. However, a single color can easily cause aesthetic fatigue in people. In order to meet consumers' pursuit of beauty and improve the mood of users, the application of gradient plastic film in raincoats, shower curtains, etc. has added fashion and personalization to the products, meeting the needs of consumers. However, when gradient plastic film is used in raincoats or shower curtains, it needs to have good waterproof performance. Moreover, raincoats or shower curtains are in a humid environment for a long time, which is very easy to grow bacteria and mold, and are easily corroded by rainwater, thereby reducing the tensile strength of the material. Therefore, it is necessary to prepare a waterproof, mildew-proof and corrosion-resistant gradient plastic film to meet its application in various environments.

Summary of the invention

The invention provides a gradient plastic film and a preparation method thereof, which solves the problems of poor mildew resistance, corrosion resistance and mechanical properties of the plastic film in the related art.

The technical solution of the present invention is as follows:

The invention provides a gradient plastic film, comprising the following raw materials in parts by weight: 10-90 parts of ethylene-vinyl acetate copolymer, 10-90 parts of polyethylene, 3-5 parts of mildewproof agent, 5-20 parts of modified mica powder, 3-5 parts of antistatic agent, and 4-6 parts of pigment;

The modified mica powder is obtained by modifying carboxylated mica powder through titanium dioxide nanotubes.

As a further technical solution, the method for preparing the carboxylated mica powder comprises the following steps: adding the mica powder into methanol, and then adding a carboxyl-containing compound for modification to obtain the carboxylated mica powder.

As a further technical solution, the carboxyl-containing compound includes one or more of oxalic acid, succinic acid, and adipic acid.

As a further technical solution, the carboxyl-containing compound is succinic acid.

In the present invention, by limiting the carboxyl-containing compound to succinic acid, the water resistance and corrosion resistance of the plastic film are further improved.

As a further technical solution, the modification temperature is 45-55° C., and the modification time is 3-5 hours.

As a further technical solution, the carboxyl-containing compound accounts for 5% of the mass of the mica powder.

As a further technical solution, the titanium dioxide nanotube has a diameter of 15-20 nm and a length of 2-10 μm.

As a further technical solution, the particle size of the mica powder is 100 mesh.

As a further technical solution, the mass ratio of the titanium dioxide nanotubes to the carboxylated mica powder is 0.07-0.11:1.

In the present invention, by limiting the mass ratio of titanium dioxide nanotubes to carboxylated mica powder to 0.07-0.11:1, the mechanical properties and corrosion resistance of the plastic film can be further improved.

As a further technical solution, the carboxylated mica powder is obtained by first modifying the mica powder with a carboxyl-containing compound and then adding 3-phenylethylene oxide-2-carboxylic acid and hexadecyltrimethylammonium bromide for a second modification.

As a further technical solution, the method for preparing the carboxylated mica powder comprises the following steps:

A1. Disperse mica powder in methanol solution and add carboxyl-containing compound to perform the first modification;

A2, adding 3-phenyloxirane-2-carboxylic acid and hexadecyltrimethylammonium bromide for a second modification, filtering and drying to obtain carboxylated mica powder.

In the present invention, mica powder is activated by ethylenediaminetetraacetic acid, 3-phenylethylene oxide-2-carboxylic acid and hexadecyltrimethylammonium bromide, thereby improving the mildew resistance and corrosion resistance of the plastic film.

As a further technical solution, the mass ratio of the added 3-phenylethylene oxide-2-carboxylic acid and hexadecyltrimethylammonium bromide to the mica powder is 1:0.6~1.5.

In the present invention, by limiting the added mass of 3-phenyloxirane-2-carboxylic acid and hexadecyltrimethylammonium bromide and the mass ratio of mica powder to 1:0.6-1.5, the tensile strength, corrosion resistance and mildew resistance of the plastic film are further improved.

As a further technical solution, the mass ratio of the 3-phenylethylene oxide-2-carboxylic acid to hexadecyltrimethylammonium bromide is 1:2-5.

In the present invention, by limiting the mass ratio of 3-phenyloxirane-2-carboxylic acid to hexadecyltrimethylammonium bromide to 1:2-5, the tensile strength, corrosion resistance and mildew resistance of the plastic film can be further improved.

As a further technical solution, the mass ratio of the 3-phenylethylene oxide-2-carboxylic acid to hexadecyltrimethylammonium bromide is 1:3.

As a further technical solution, the temperature of the first modification and the temperature of the second modification are independently 45-55° C., and the time of the first modification and the time of the second modification are independently 1.5-2.5 h.

As a further technical solution, the preparation method of the modified mica powder comprises the following steps: adding titanium dioxide nanotubes into water, then adding a silane coupling agent and active mica powder for modification, and filtering and drying to obtain the modified mica powder.

As a further technical solution, the silane coupling agent is 3-aminopropyltriethoxysilane.

As a further technical solution, the added amount of the silane coupling agent is 2% to 4% of the mass of the titanium dioxide nanotubes.

As a further technical solution, the modification temperature is 40-50°C, and the modification time is 1-2h.

As a further technical solution, the polyethylene consists of low-density polyethylene and linear low-density polyethylene.

In the present invention, by limiting the polyethylene to consist of low-density polyethylene and linear low-density polyethylene, the tensile strength and corrosion resistance of the plastic film are further improved.

As a further technical solution, the mass ratio of the low-density polyethylene to the linear low-density polyethylene is 1:0.5~2.

As a further technical solution, the mildew inhibitor includes one or more of zinc pyrithione, 2-benzisothiazolin-3-one, and 3-iodo-2-propynylbutylcarbamate.

In the present invention, the addition of the mildew-proof agent can effectively prevent the growth and reproduction of mildew and improve the mildew-proof property of the plastic film.

As a further technical solution, the antistatic agent includes one or both of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate and dodecyl dihydrogen phosphate.

The present invention also provides a method for preparing a gradient plastic film, comprising the following steps:

S1. Ethylene-vinyl acetate copolymer, polyethylene, mildew inhibitor, modified mica powder and antistatic agent are mixed evenly, and then divided into two parts, one of which is added with pigment and mixed again to obtain mixed material A, and the other is mixed material B;

S2. The mixed materials A and B are melt-extruded through different extruders respectively, and then cast to obtain a gradient plastic film.

In the present invention, two plastic raw materials of different colors are simultaneously added into different extruders for melt extrusion to obtain extrudate A and extrudate B, which are then added into a pigment distributor of a casting machine. Blades are arranged on a rotating rod of the casting machine so that the extrudate A in the pigment distributor flows toward a pigment rod through the surface of the blades. A guide groove is arranged at the junction of the blades and the pigment rod. The extrudate B flows toward the front end of the pigment rod through the guide groove and is mixed with the extrudate A, thereby obtaining a plastic film with a color gradient.

The working principle and beneficial effects of the present invention are:

In the present invention, ethylene-vinyl acetate copolymer and polyethylene are used as base materials, wherein the ethylene-vinyl acetate copolymer has the characteristics of good toughness, low temperature resistance, water resistance, environmental protection and the like, and the polyethylene has good corrosion resistance and melt viscosity. The ethylene-vinyl acetate copolymer and the polyethylene are compounded to make the plastic film have good toughness, corrosion resistance and water resistance. The addition of the mildew inhibitor improves the mildew resistance of the plastic film. The mica powder has a unique flaky structure and forms a physical barrier in the plastic matrix, which can effectively block water vapor and corrosive media. The addition of titanium dioxide nanotubes can be filled between the lamellae of the mica powder to improve the physical shielding effect. The carboxylated mica powder can better improve the filling effect of the carbon dioxide nanotubes, thereby solving the problems of low mildew resistance, corrosion resistance and mechanical properties of the plastic film.

DETAILED DESCRIPTION

The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the following embodiments and comparative examples:

Ethylene-vinyl acetate copolymer, model LVS430, purchased from Shanghai Wochengying Trading Co., Ltd.;

Low-density polyethylene, model 2426H, purchased from Suzhou Yitianli Plastic Co., Ltd.;

Linear low-density polyethylene, model DFDA-7042N, was purchased from Shanghai Shunshi Plastics Co., Ltd.;

Titanium dioxide nanotubes, with a diameter of 15–20 nm and a length of 2–10 μm, were purchased from Zhongke Jinyan (Beijing) Technology Co., Ltd.;

Mica powder, particle size 100 mesh, was purchased from Hebei Houkang Mineral Products Co., Ltd.

Example 1

A method for preparing a gradient plastic film comprises the following steps:

S1. After 90 parts of ethylene-vinyl acetate copolymer, 5 parts of low-density polyethylene, 5 parts of linear low-density polyethylene, 3 parts of zinc pyrithione, 5 parts of modified mica powder, and 3 parts of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate are mixed evenly, the mixture is divided into two parts, 4 parts of pigment are added to one part and mixed again to obtain a mixed material A, and the other part is a mixed material B;

S2. The mixed materials A and B are melt-extruded through different extruders respectively, and then cast to obtain a gradient plastic film.

The preparation method of modified mica powder comprises the following steps:

A1. Disperse 40 g of mica powder (100 mesh) in 300 mL of methanol solution, add 2 g of oxalic acid, heat to 45 ° C, keep warm for 5 hours, filter and dry to obtain carboxylated mica powder;

A2. Add 4.2 g of titanium dioxide nanotubes (diameter 15-20 nm, length 2-10 μm) into 400 mL of deionized water, then add 0.084 g of 3-aminopropyltriethoxysilane and 60 g of carboxylated mica powder, stir at 40 °C for 2 h, filter and dry to obtain modified mica powder.

Example 2

A method for preparing a gradient plastic film comprises the following steps:

S1. After 10 parts of ethylene-vinyl acetate copolymer, 60 parts of low-density polyethylene, 30 parts of linear low-density polyethylene, 4 parts of 2-benzisothiazolin-3-one, 12 parts of modified mica powder, and 4 parts of dodecyl dihydrogen phosphate are mixed evenly, the mixture is divided into two parts, 5 parts of pigment are added to one part and mixed again to obtain a mixture A, and the other part is a mixture B;

S2. The mixed materials A and B are melt-extruded through different extruders respectively, and then cast to obtain a gradient plastic film.

The preparation method of modified mica powder comprises the following steps:

A1. Disperse 40 g mica powder (100 mesh) in 300 mL methanol solution, add 2 g succinic acid, heat to 50 ° C, keep warm for 4 hours, filter and dry to obtain carboxylated mica powder;

A2. Add 4.32 g of titanium dioxide nanotubes (diameter 15-20 nm, length 2-10 μm) into 400 mL of deionized water, then add 0.130 g of 3-aminopropyltriethoxysilane and 48 g of carboxylated mica powder, stir at 45 °C for 2 h, filter and dry to obtain modified mica powder.

Example 3

A method for preparing a gradient plastic film comprises the following steps:

S1. After 10 parts of ethylene-vinyl acetate copolymer, 30 parts of low-density polyethylene, 60 parts of linear low-density polyethylene, 5 parts of 3-iodo-2-propynyl butyl carbamate, 20 parts of modified mica powder, and 5 parts of dodecyl dihydrogen phosphate are mixed evenly, the mixture is divided into two parts, one of which is added with 6 parts of pigment and mixed again to obtain a mixture A, and the other is a mixture B;

S2. The mixed materials A and B are melt-extruded through different extruders respectively, and then cast to obtain a gradient plastic film.

The preparation method of modified mica powder comprises the following steps:

A1. Disperse 40 g of mica powder (100 mesh) in 300 mL of methanol solution, add 2 g of adipic acid, heat to 55 ° C, keep warm for 3 hours, filter and dry to obtain carboxylated mica powder;

A2. Add 4.4 g of titanium dioxide nanotubes (diameter 15-20 nm, length 2-10 μm) into 400 mL of deionized water, then add 0.176 g of 3-aminopropyltriethoxysilane and 40 g of carboxylated mica powder, stir at 40 °C for 1 h, filter and dry to obtain modified mica powder.

Example 4

The only difference between this embodiment and embodiment 1 is that oxalic acid is replaced by an equal amount of succinic acid.

Example 5

The only difference between this embodiment and embodiment 1 is that oxalic acid is replaced by an equal amount of adipic acid.

Example 6

The only difference between this embodiment and embodiment 4 is that the preparation method of modified mica powder comprises the following steps:

A1. Disperse 40g mica powder (100 mesh) in 600mL methanol solution, add 2g succinic acid, heat to 45℃, and keep warm for 2.5h;

A2, add 24g of hexadecyltrimethylammonium bromide, heat to 45°C and keep warm for 2.5h, filter and dry to obtain carboxylated mica powder;

A3. Add 4.2 g of titanium dioxide nanotubes (diameter 15-20 nm, length 2-10 μm) into 400 mL of deionized water, then add 0.084 g of 3-aminopropyltriethoxysilane and 60 g of carboxylated mica powder, stir at 40 °C for 2 h, filter and dry to obtain modified mica powder.

The plastic film prepared in this example was tested for mildew resistance.

Example 7

The difference between this embodiment and embodiment 6 is that hexadecyltrimethylammonium bromide is replaced by an equal amount of 3-phenyloxirane-2-carboxylic acid.

Example 8

The only difference between this embodiment and embodiment 6 is that cetyltrimethylammonium bromide is replaced by equal amounts of cetyltrimethylammonium bromide and 3-phenylethylene oxide-2-carboxylic acid in a mass ratio of 1:1.

Embodiment 9

The only difference between this embodiment and embodiment 8 is that the added amount of 3-phenyloxirane-2-carboxylic acid is 2 g, and the added amount of hexadecyltrimethylammonium bromide is 22 g.

Example 10

The only difference between this embodiment and embodiment 8 is that the added amount of 3-phenyloxirane-2-carboxylic acid is 8 g, and the added amount of hexadecyltrimethylammonium bromide is 16 g.

Embodiment 11

The only difference between this embodiment and embodiment 8 is that the added amount of 3-phenyloxirane-2-carboxylic acid is 6 g, and the added amount of hexadecyltrimethylammonium bromide is 18 g.

Example 12

The only difference between this embodiment and embodiment 8 is that the added amount of 3-phenyloxirane-2-carboxylic acid is 4 g, and the added amount of hexadecyltrimethylammonium bromide is 20 g.

Comparative Example 1

The only difference between this comparative example and Example 1 is that the modified mica powder is replaced by an equal amount of titanium dioxide nanotubes (with a diameter of 15-20 nm and a length of 2-10 μm).

Comparative Example 2

The only difference between this comparative example and Example 1 is that the modified mica powder is replaced by an equal amount of the carboxylated mica powder prepared in Example 1.

Comparative Example 3

The difference between this comparative example and Example 1 is only the preparation method of the modified mica powder. The preparation method of the modified mica powder in this comparative example is:

4.2 g of titanium dioxide nanotubes (diameter of 15-20 nm, length of 2-10 μm) were added to 400 mL of deionized water, and then 0.084 g of 3-aminopropyltriethoxysilane and 60 g of mica powder were added. The mixture was stirred at 40° C. for 2 h, and the modified mica powder was obtained by filtration and drying.

Experimental Example 1

The method for determining the corrosion resistance of the gradient plastic film obtained in Examples 1 to 12 and Comparative Examples 1 to 3 is as follows: after the plastic film is immersed in a 15wt% sulfuric acid solution for 10 days, the tensile strength of the film before and after immersion is tested according to the determination method in GB/T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets", and the tensile strength retention rate is calculated, and the calculation formula is: tensile strength retention rate = tensile strength after immersion / tensile strength before immersion × 100%; the test results are recorded in Table 1.

Table 1 Plastic film performance test results

Compared with Example 1, Comparative Example 1 only added titanium dioxide nanotubes, Comparative Example 2 only added carboxylated mica powder, and Comparative Example 3 added titanium dioxide nanotubes to modify non-carboxylated mica powder. As a result, the tensile strength of the plastic films prepared in Comparative Examples 1 to 3 and the tensile strength retention rate after acid immersion were lower than those in Example 1, indicating that the addition of carboxylated mica powder can improve the tensile strength and corrosion resistance of the plastic film together with titanium dioxide nanotubes.

Compared with Example 1, Examples 4 to 5 changed the carboxyl-containing compound. As a result, the tensile strength of the plastic film prepared in Example 4 and the tensile strength retention rate after acid immersion were higher than those in Examples 1 and 5, indicating that the carboxylation of mica powder with succinic acid can further improve the tensile strength and corrosion resistance of the plastic film.

Compared with Example 4, Example 6 added hexadecyltrimethylammonium bromide to modify the mica powder for the second time, Example 7 added 3-phenyloxirane-2-carboxylic acid in the second modification, and Example 8 added hexadecyltrimethylammonium bromide and 3-phenyloxirane-2-carboxylic acid at the same time in the second modification. As a result, the tensile strength of the plastic film prepared in Example 8 and the tensile strength retention rate after acid immersion were higher than those in Examples 4, 6 and 7, indicating that the use of hexadecyltrimethylammonium bromide and 3-phenyloxirane-2-carboxylic acid to modify the mica powder for the second time can further improve the tensile strength and corrosion resistance of the plastic film.

Compared with Example 8, Examples 9 to 12 change the mass ratio of 3-phenyloxirane-2-carboxylic acid and hexadecyltrimethylammonium bromide. As a result, the tensile strength and the tensile strength retention rate after acid immersion of the plastic films obtained in Examples 10 to 12 are higher than those in Examples 8 and 9, indicating that when the mass ratio of 3-phenyloxirane-2-carboxylic acid and hexadecyltrimethylammonium bromide is 1:2 to 5, the tensile strength and corrosion resistance of the plastic film can be further improved; by comparing Examples 10 to 12, it is found that the tensile strength and the tensile strength retention rate after acid immersion of the plastic film obtained in Example 11 are higher than those in Examples 10 and 12, indicating that when the mass ratio of 3-phenyloxirane-2-carboxylic acid and hexadecyltrimethylammonium bromide is 1:3, the tensile strength and corrosion resistance of the obtained plastic film are the highest.

Experimental Example 2

The mildew resistance of the plastic film prepared in Example 6 was determined according to Method 3-Aspergillus niger plate method in AATCC30-2017. The culture period was 7 days. The control sample was sterilized filter paper. The test results are shown in Table 2.

Table 2 Test results of anti-mildew performance of plastic films

It can be seen from Table 2 that no mold grows on the surface of the plastic film prepared by the present invention, indicating that the plastic film has good mildew resistance.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The gradual change plastic film is characterized by comprising the following raw materials in parts by weight: 10-90 parts of ethylene-vinyl acetate copolymer, 10-90 parts of polyethylene, 3-5 parts of mildew inhibitor, 5-20 parts of modified mica powder, 3-5 parts of antistatic agent and 4-6 parts of pigment;

the modified mica powder is obtained by modifying carboxylated mica powder through a titanium dioxide nanotube.

2. The graded plastic film according to claim 1, wherein the mass ratio of the titanium dioxide nanotubes to the carboxylated mica powder is 0.07-0.11:1.

3. A progressive plastic film according to claim 1, characterized in that the preparation method of carboxylated mica powder comprises the following steps: adding the mica powder into methanol, and then adding a carboxyl-containing compound for modification to obtain carboxylated mica powder.

4. A graded plastic film as in claim 3, wherein the carboxyl group containing compound comprises one or more of oxalic acid, succinic acid, adipic acid.

5. The progressive plastic film of claim 1, wherein the modified mica powder preparation method comprises the following steps: adding titanium dioxide nanotubes into water, adding a silane coupling agent and carboxylated mica powder for modification, filtering and drying to obtain modified mica powder.

6. A graded plastic film as in claim 1, wherein the polyethylene is comprised of a low density polyethylene and a linear low density polyethylene.

7. The graded plastic film of claim 6, wherein the mass ratio of the low density polyethylene to the linear low density polyethylene is 1:0.5-2.

8. A graded plastic film according to claim 1, wherein the mildew preventive comprises one or more of zinc pyrithione, 2-benzisothiazolin-3-one, 3-iodo-2-propynylbutylcarbamate.

9. A graded plastic film according to claim 1, wherein the antistatic agent comprises one or both of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate and dodecyl dihydrogen phosphate.

10. The preparation method of the gradual change plastic film according to any one of claims 1 to 9, comprising the following steps:

S1, uniformly mixing an ethylene-vinyl acetate copolymer, polyethylene, a mildew inhibitor, modified mica powder and an antistatic agent, dividing the mixture into two parts, wherein one part is added with pigment and mixed again to obtain a mixed material A, and the other part is a mixed material B;

S2, respectively melting and extruding the mixed materials A and B through different extruders, and carrying out tape casting to obtain the gradual change plastic film.