阅读说明：本技术 一种可降解塑料快递袋 (Degradable plastic express bag ) 是由 胡颖妮 于 2021-07-19 设计创作，主要内容包括：本发明公开了一种可降解塑料快递袋,包括如下重量份的组分：高密度聚乙烯20-50份；低密度聚乙烯10-30份；淀粉15-30份；聚羟基脂肪酸酯8-15份；硅铝薄膜开口剂1-5份；偶联剂1-3份；抗氧化剂0.1-1份。本发明以高密度聚乙烯、低密度聚乙烯为基料,基料与淀粉、聚羟基脂肪酸酯、偶联剂性形成可降解塑料快递袋的结构骨架,加上硅铝薄膜开口剂,可增加快递袋的开口性能及拉伸强度,其中,淀粉为营养物质,可为微生物提供繁殖场所,随着淀粉的生物降解,结构骨架逐渐崩解,其他物质也逐步被微生物降解,使该快递袋逐步被降解,避免污染环境。(The invention discloses a degradable plastic express delivery bag which comprises the following components in parts by weight: 20-50 parts of high-density polyethylene; 10-30 parts of low-density polyethylene; 15-30 parts of starch; 8-15 parts of polyhydroxyalkanoate; 1-5 parts of a silicon-aluminum film opening agent; 1-3 parts of a coupling agent; 0.1-1 part of antioxidant. The invention takes high-density polyethylene and low-density polyethylene as base materials, the base materials, starch, polyhydroxyalkanoate and a coupling agent form a structural framework of the degradable plastic express bag, and a silicon-aluminum film opening agent is added, so that the opening performance and the tensile strength of the express bag can be improved, wherein the starch is a nutrient substance and can provide a breeding place for microorganisms, the structural framework is gradually disintegrated along with the biodegradation of the starch, other substances are gradually degraded by the microorganisms, and the express bag is gradually degraded to avoid environmental pollution.)

1. The degradable plastic express delivery bag is characterized by comprising the following components in parts by weight:

20-50 parts of high-density polyethylene;

10-30 parts of low-density polyethylene;

15-30 parts of starch;

8-15 parts of polyhydroxyalkanoate;

1-5 parts of a silicon-aluminum film opening agent;

1-3 parts of a coupling agent;

0.1-1 part of antioxidant.

2. The degradable plastic express delivery bag of claim 1, comprising the following components in parts by weight:

20-40 parts of high-density polyethylene;

15-25 parts of low-density polyethylene;

15-25 parts of starch;

10-15 parts of polyhydroxyalkanoate;

1-5 parts of a silicon-aluminum film opening agent;

1-3 parts of a coupling agent;

0.1-1 part of antioxidant.

3. The degradable plastic express delivery bag of claim 1, wherein the silicon-aluminum film opening agent is prepared by:

s1: preparing a water glass solution with the silicon dioxide concentration of 10-20 wt% and the modulus of 3.35 for later use;

s2: adding water and aluminum salt into a reaction kettle at the temperature of 30-60 ℃, adding 10-30 wt% sulfuric acid after the aluminum salt is completely dissolved, and adjusting the pH value to 1-3;

s3: simultaneously adding the prepared water glass solution and sulfuric acid into an aluminum salt solution, wherein the parallel flow time is 30-60 min, and the pH value of the system is kept at 1-3;

s4: after the parallel flow is finished, adding sodium hydroxide, adjusting the pH value to 8-10, simultaneously heating to 80-100 ℃, and aging for 2h at the temperature;

s5: after the aging is finished, adding dilute sulfuric acid, adjusting the pH value to 2-4, aging for 0.5-1.5 h, cooling to 60-70 ℃, and filtering to obtain a filter cake;

s6: sequentially washing the filter cake with 1-3 wt% sulfuric acid and water, re-dispersing the washed filter cake in a small amount of water, adding 1-3% of solid content organosilane dispersing agent, and uniformly dispersing to obtain slurry;

s7: spray drying the slurry, and then crushing by air flow to obtain the silicon-aluminum film opening agent with the grain size of 3-7 mu m.

4. The degradable plastic express delivery bag of claim 3 wherein the aluminum salt solution is one or more of a combination of an aluminum sulfate solution, an aluminum nitrate solution, and an aluminum chloride solution.

5. The degradable plastic express delivery bag of claim 3, wherein the molar ratio of aluminum in the aluminum salt solution to silicon in the water glass is 0.05-0.30: 1.

6. the degradable plastic express delivery bag of claim 3, wherein the organosilane dispersant is one or more combinations of KH-550, KH-104, KH-910.

7. The degradable plastic express delivery bag of claim 1, wherein the polyhydroxyalkanoate is a mixture of short-chain polyhydroxyalkanoate and medium-length polyhydroxyalkanoate in a mass ratio of 1: 1-3.

8. The degradable plastic express delivery bag of claim 1, wherein the silicon-aluminum film opening agent, the high-density polyethylene and the starch are mixed in a mass ratio of 1: 10-15: 5-8.

9. The degradable plastic express delivery bag of claim 1, wherein the mass ratio of the coupling agent to the high density polyethylene to the starch to the polyhydroxyalkanoate is 1: 15-20: 5-8: 5.

10. the degradable plastic express delivery bag of claim 1, wherein the coupling agent is a silane coupling agent or a stearic acid coupling agent; the antioxidant is one or a combination of several of antioxidant 1010, thioester, fluorapatite and cyanuric acid.

Technical Field

The invention relates to the technical field of polymers, in particular to a degradable plastic express bag.

Background

With the development of society and the improvement of living standard of people, more and more people select to shop on the internet, and the commodity exchange of people is more and more frequent, so that the logistics industry is rapidly developed. During the transportation process of the articles, the articles need to be packaged by using packaging bags so as to avoid the contamination of the articles. The plastic express bags are used as express bags in a large amount due to the advantages of light weight and low price, but the use of the express bags in a large amount causes increasingly serious white pollution to the environment. The preparation of degradable express delivery bags is a technical problem which needs to be solved at present.

The plastic film of degradable express bag is in production and storage process, and its surface has a large amount of exposed molecular chains after the film shaping, produces macromolecular chain intertwine adhesion after two films are closed, therefore receives the hot pressing or receives the thing pressure condition under, and the adhesion takes place easily for two films. In the subsequent production and use processes, the unwinding speed of the plastic film is slightly influenced, and the plastic film cannot be unfolded for use due to the serious influence, so that the difficulty is brought to the automatic packaging application. In order to solve the problem, in the production process of the plastic film, solid inert particles are added as an opening agent, so that a large number of raised small points are formed on the surfaces of the film and the sheet, and a bridging phenomenon between two layers is formed, so that the problem of adhesion caused by the fact that two inner wall surfaces are attached together is avoided; on the other hand, air is made to penetrate into the inner walls of the two films along the gaps between the small raised points formed on the surfaces of the films/sheets by the opening agent so as to counteract atmospheric pressure, thereby effectively preventing the adhesion between the films.

The initial opening agent is talcum powder, diatomite, etc., and the intermediate stage is developed into oleamide, erucamide EBS derivative, etc. The auxiliary agents have defects in different degrees, and are mainly reflected in poor dispersibility of opening agents such as talcum powder, diatomite and the like; the opening agents such as oleamide and erucamide EBS derivatives are easy to be precipitated on the surface of the film, and influence the printing property and the color of the film.

The current opening agent has been developed into porous silicon-based oxide, the main component of which is silicon dioxide particles, which form a plurality of fine and hard protrusions on the surface of the film, reduce the contact area between the films, so as to reduce the friction between the films and facilitate the separation of the films, and the defects are that the bonding force between the silicon dioxide particles and the film resin is poor, the silicon dioxide particles are not easy to disperse, and the opening performance is affected.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the degradable plastic express delivery bag, the opening agent of the degradable plastic express delivery bag can be uniformly dispersed in the film resin, and the opening agent and the film resin have good affinity and can achieve a better opening effect.

The invention is realized by adopting the following technical scheme:

a degradable plastic express delivery bag comprises the following components in parts by weight:

20-50 parts of high-density polyethylene;

10-30 parts of low-density polyethylene;

15-30 parts of starch;

8-15 parts of polyhydroxyalkanoate;

1-5 parts of a silicon-aluminum film opening agent;

1-3 parts of a coupling agent;

0.1-1 part of antioxidant.

Further, the degradable plastic express delivery bag comprises the following components in parts by weight:

20-40 parts of high-density polyethylene;

15-25 parts of low-density polyethylene;

15-25 parts of starch;

10-15 parts of polyhydroxyalkanoate;

1-5 parts of a silicon-aluminum film opening agent;

1-3 parts of a coupling agent;

0.1-1 part of antioxidant.

Further, the silicon-aluminum film opening agent is prepared by the following steps:

s1: preparing a water glass solution with the silicon dioxide concentration of 10-20 wt% and the modulus of 3.35 for later use;

s2: adding water and aluminum salt into a reaction kettle at the temperature of 30-60 ℃, adding 10-30 wt% sulfuric acid after the aluminum salt is completely dissolved, and adjusting the pH value to 1-3;

s3: simultaneously adding the prepared water glass solution and sulfuric acid into an aluminum salt solution, wherein the parallel flow time is 30-60 min, and the pH value of the system is kept at 1-3;

s4: after the parallel flow is finished, adding sodium hydroxide, adjusting the pH value to 8-10, simultaneously heating to 80-100 ℃, and aging for 2h at the temperature;

s5: after the aging is finished, adding dilute sulfuric acid, adjusting the pH value to 2-4, aging for 0.5-1.5 h, cooling to 60-70 ℃, and filtering to obtain a filter cake;

s6: sequentially washing the filter cake with 1-3 wt% sulfuric acid and water, re-dispersing the washed filter cake in a small amount of water, adding 1-3% of solid content organosilane dispersing agent, and uniformly dispersing to obtain slurry;

s7: spray drying the slurry, and then crushing by air flow to obtain the silicon-aluminum film opening agent with the grain size of 3-7 mu m.

Further, the aluminum salt solution is one or more of aluminum sulfate solution, aluminum nitrate solution and aluminum chloride solution.

Further, the molar ratio of aluminum in the aluminum salt solution to silicon in the water glass is 0.05-0.30: 1.

further, the organosilane dispersing agent is one or more of KH-550, KH-104 and KH-910.

Further, the polyhydroxy fatty acid ester is a mixture of short-chain polyhydroxy fatty acid ester and medium-length polyhydroxy fatty acid ester in a mass ratio of 1: 1-3.

Further, the mass of the silicon-aluminum film opening agent, the high-density polyethylene and the starch is 1: 10-15: 5-8.

Further, the mass ratio of the coupling agent to the high-density polyethylene to the starch to the polyhydroxyalkanoate is 1: 15-20: 5-8: 5.

further, the coupling agent is a silane coupling agent or a stearic acid coupling agent; the antioxidant is one or a combination of several of antioxidant 1010, thioester, fluorapatite and cyanuric acid.

Compared with the prior art, the invention has the beneficial effects that:

the silicon-aluminum film opening agent provided by the invention can be uniformly dispersed in a plastic film, and by adding aluminum species, on one hand, the bulk ratio of the obtained opening agent can be regulated, and simultaneously, the surface defects of opening agent particles are increased, so that the opening agent particles and an organosilane dispersing agent have better combination, the affinity degree of the obtained opening agent particles and film resin is improved, the antistatic property, the lubricating property and the moisture resistance of the opening agent particles are improved, the friction coefficient and the bonding resistance are reduced, and a better opening effect is achieved.

The invention takes high-density polyethylene and low-density polyethylene as base materials, the base materials, starch, polyhydroxyalkanoate and a coupling agent form a structural framework of the degradable plastic express bag, and a silicon-aluminum film opening agent is added, so that the opening performance and the tensile strength of the express bag can be improved, wherein the starch is a nutrient substance and can provide a breeding place for microorganisms, the structural framework is gradually disintegrated along with the biodegradation of the starch, other substances are gradually degraded by the microorganisms, and the express bag is gradually degraded to avoid environmental pollution.

Detailed Description

The present invention is further described below with reference to specific embodiments, and it should be noted that, without conflict, any combination between the embodiments or technical features described below may form a new embodiment.

The invention provides a degradable plastic express delivery bag which comprises the following components in parts by weight:

20-50 parts of high-density polyethylene; 10-30 parts of low-density polyethylene; 15-30 parts of starch; 8-15 parts of polyhydroxyalkanoate; 1-5 parts of a silicon-aluminum film opening agent; 1-3 parts of a coupling agent; 0.1-1 part of antioxidant.

By adding aluminum species into the silicon-aluminum film opening agent, on one hand, the bulk ratio of the obtained opening agent can be regulated, and simultaneously, the surface defects of opening agent particles are increased, so that the opening agent particles are better combined with an organosilane dispersing agent, the affinity degree of the obtained opening agent particles and film resin is improved, the antistatic property, the lubricating property and the moisture-proof property of the opening agent particles are improved, the friction coefficient and the bonding resistance are reduced, and a better opening effect is achieved.

The preparation method of the degradable plastic express delivery bag comprises the following steps: at normal temperature, putting high-density polyethylene, low-density polyethylene, starch, polyhydroxyalkanoate and a coupling agent into a stirrer, uniformly stirring, adding a silicon-aluminum film opening agent and an antioxidant, continuously stirring until the materials are uniformly mixed to obtain a mixture, then extruding and granulating the mixture on a double-screw extruder, and finally carrying out melt extrusion and blow molding to obtain the express bag.

The coupling agent in the following embodiments is vinyltrimethoxysilane coupling agent, the antioxidant is antioxidant 1010, the polyhydroxyalkanoate is a mixture of short-chain polyhydroxyalkanoate and medium-length polyhydroxyalkanoate with the mass ratio of 1:1, and raw materials, equipment and the like used in the following examples can be obtained by purchase except for special limitations.

Example 1:

a degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The silicon-aluminum film opening agent is prepared by the following method:

50L of bottom water and 45 moles of aluminum sulfate are injected into a stirring reaction vessel at the temperature of 30 ℃, after the aluminum sulfate is completely dissolved, 30 wt% of sulfuric acid is added to adjust the pH value of the system to be 2, 20 wt% of sodium silicate 75L and 30 wt% of sulfuric acid are added in a concurrent flow manner, the pH value of the system is kept to be 2, and the concurrent flow time is 30 minutes.

After the completion of the parallel flow, the temperature was adjusted to 90 ℃, the pH was adjusted to 9 with sodium hydroxide, and aging was carried out for 2 hours. After the aging is finished, adding sulfuric acid to adjust the pH value to 3, aging for 0.5 hour, then cooling to 60 ℃, and filtering to obtain a filter cake. Washing the filter cake with 1 wt% sulfuric acid, washing with tap water and pure water, and press filtering to obtain the filter cake. The filter cake was redispersed in a small amount of water and 3% solids content of organosilane dispersant KH550 was added. And after uniform dispersion, spray drying the obtained slurry, and performing jet milling to obtain a product with the particle size of 3-7 microns. The physical and chemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in a table I:

watch 1

The preparation method of the degradable plastic express delivery bag comprises the following steps: at normal temperature, putting high-density polyethylene, low-density polyethylene, starch, polyhydroxyalkanoate and a coupling agent into a stirrer, uniformly stirring, adding a silicon-aluminum film opening agent and an antioxidant, continuously stirring until the materials are uniformly mixed to obtain a mixture, then extruding and granulating the mixture on a double-screw extruder, and finally carrying out melt extrusion and blow molding to obtain the express bag.

Example 2:

a degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The silicon-aluminum film opening agent is prepared by the following method:

50L of bottom water and 15 moles of aluminum nitrate are injected into a stirring reaction vessel at the temperature of 60 ℃, after the aluminum nitrate is completely dissolved, 10 wt% of sulfuric acid is added to adjust the pH value of the system to be 2, 75L of water glass with the concentration of 20 wt% and 10 wt% of sulfuric acid are added in a concurrent mode, the pH value of the system is kept to be 2, and the concurrent flow time is 90 minutes. After the completion of the parallel flow, the temperature was adjusted to 100 ℃, the pH was adjusted to 10 with sodium hydroxide, and aging was carried out for 2 hours. After the aging is finished, adding sulfuric acid to adjust the pH value to 2, aging for 1.5 hours, then cooling to 60 ℃, and filtering to obtain a filter cake. Washing the filter cake with 3 wt% sulfuric acid, washing with tap water and pure water, and press filtering to obtain the filter cake. The filter cake was redispersed in a small amount of water and the organosilane dispersant KH550 was added at 1% solids content. And after uniform dispersion, spray drying the obtained slurry, and performing jet milling to obtain a product with the particle size of 3-7 microns. The physicochemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in the table II:

watch two

The preparation method is the same as that of example 1.

Example 3:

a degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The silicon-aluminum film opening agent is prepared by the following method:

50L of bottom water and 30 moles of aluminum chloride are injected into a stirring reaction vessel at the temperature of 40 ℃, sulfuric acid with the concentration of 30 wt% is added after the aluminum chloride is completely dissolved to adjust the pH value of the system to be 2, 75L of water glass with the concentration of 10 wt% and 30 wt% of sulfuric acid are added in a concurrent mode, the pH value of the system is kept to be 2, and the concurrent flow time is 60 minutes. After the completion of the parallel flow, the temperature was adjusted to 80 ℃, the pH was adjusted to 8 with sodium hydroxide, and aging was carried out for 2 hours. After the aging is finished, adding sulfuric acid to adjust the pH value to be 4, aging for 1 hour, then cooling to 70 ℃, and filtering to obtain a filter cake. Washing the filter cake with 1 wt% sulfuric acid, washing with tap water and pure water, and press filtering to obtain the filter cake. The filter cake was redispersed in a small amount of water and the organosilane dispersant KH104 was added at 2% solids content. And after uniform dispersion, spray drying the obtained slurry, and performing jet milling to obtain a product with the particle size of 3-7 microns. The physicochemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in the third table:

watch III

The preparation method is the same as that of example 1.

Example 4:

a degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The silicon-aluminum film opening agent is prepared by the following method:

50L of bottom water and 15 moles of aluminum sulfate are injected into a stirring reaction vessel at the temperature of 30 ℃, after the aluminum sulfate is completely dissolved, 30 wt% of sulfuric acid is added to adjust the pH value of the system to be 2, 20 wt% of sodium silicate 75L and 30 wt% of sulfuric acid are added in a concurrent flow manner, the pH value of the system is kept to be 2, and the concurrent flow time is 30 minutes. After the completion of the parallel flow, the temperature was adjusted to 90 ℃, the pH was adjusted to 9 with sodium hydroxide, and aging was carried out for 2 hours. After the aging is finished, adding sulfuric acid to adjust the pH value to 3, aging for 0.5 hour, then cooling to 60 ℃, and filtering to obtain a filter cake. Washing the filter cake with 1 wt% sulfuric acid, washing with tap water and pure water, and press filtering to obtain the filter cake. The filter cake was redispersed in a small amount of water and 2% solids content of organosilane dispersant KH910 was added. And after uniform dispersion, spray drying the obtained slurry, and performing jet milling to obtain a product with the particle size of 3-7 microns. The physicochemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in the fourth table:

watch four

The preparation method is the same as that of example 1.

Example 5:

a degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The silicon-aluminum film opening agent is prepared by the following method:

under the condition of 30 ℃ of temperature, 50L of bottom water and 30 moles of aluminum sulfate are injected into a stirring reaction vessel, after the aluminum sulfate is completely dissolved, 30 wt% of sulfuric acid is added to adjust the pH value of the system to be 2, 20 wt% of sodium silicate 75L and 30 wt% of sulfuric acid are added in a concurrent flow mode, the pH value of the system is kept to be 2, and the concurrent flow time is 30 minutes. After the completion of the parallel flow, the temperature was adjusted to 90 ℃, the pH was adjusted to 9 with sodium hydroxide, and aging was carried out for 2 hours. After the aging is finished, adding sulfuric acid to adjust the pH value to 3, aging for 0.5 hour, then cooling to 60 ℃, and filtering to obtain a filter cake. Washing the filter cake with 1 wt% sulfuric acid, washing with tap water and pure water, and press filtering to obtain the filter cake. The filter cake was redispersed in a small amount of water and 2% solids content of the organosilane dispersant KH550 was added. And after uniform dispersion, spray drying the obtained slurry, and performing jet milling to obtain a product with the particle size of 3-7 microns. The physicochemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in the table five:

watch five

The preparation method is the same as that of example 1.

In the above embodiments, each material is not limited to the above components, and each material may also be composed of other single components or multiple components described in the present invention, and the component parts of each material are not limited to the above parts, and the component parts of each material may also be a combination of other component parts described in the present invention, and are not described herein again.

Comparative example 1

A degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of a silicon-aluminum film opening agent; 2 parts of a coupling agent; 0.1 part of antioxidant.

The operation of the silicon-aluminum film opening agent was the same as in example 1 except that no aluminum salt was added. The physicochemical properties of seven parallel products of the silicon-aluminum film opening agent are shown in the sixth table:

watch six

The preparation method is the same as that of example 1.

Comparative example 2

A degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 2 parts of a coupling agent; 0.1 part of antioxidant.

The preparation method is the same as that of example 1.

Comparative example 3

A degradable plastic express delivery bag comprises the following components in parts by weight:

40 parts of high-density polyethylene; 15 parts of low-density polyethylene; 15 parts of starch; 10 parts of polyhydroxyalkanoate; 3 parts of erucamide; 2 parts of a coupling agent; 0.1 part of antioxidant.

The preparation method is the same as that of example 1.

Performance testing and Effect evaluation

The performance of the express bags obtained in examples 1-5 and the express bags obtained in comparative examples 1-3 will be tested, and degradation observed by exposing the express bags to soil naturally to observe their degradation changes, if as shown in table seven below.

Watch seven

Through the comparative analysis, the express bag prepared from the degradable plastic express bag material has good tensile strength and good openness, and after the express bag is naturally exposed in soil for 30 days, the express bag has more than 55% of area with obvious cracks, which shows that the express bag material has good composite effects of photodegradation and biodegradation under the action of biological erosion and illumination.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.