阅读说明：本技术 一种聚丙烯基复合集装袋材料的制备方法 (Preparation method of polypropylene-based composite packaging bag material ) 是由 赵炜焯 于 2019-10-15 设计创作，主要内容包括：本发明涉及一种聚丙烯基复合集装袋材料的制备方法,属于包装材料技术领域。本发明以聚丙烯为基材,并添加改性碳纤维,制备一种聚丙烯基复合集装袋材料,聚丙烯是一种半结晶的热塑性塑料,具有较高的耐冲击性,机械性质强韧,抗多种有机溶剂和酸碱腐蚀,以聚丙烯为基材制备集装袋材料,可以有效提高集装袋材料的综合性能,将碳纤维通过硝酸和过氧化氢改性后,在复合过程中处于熔融状态的聚丙烯在高压下进入改性碳纤维的纹孔内,改善集装袋的物理力学性质,碳纤维具有优良的导电性,加入碳纤维可以有为集装袋提供载流子,碳纤维能在集装袋复合材料中形成导电网络,可以有效提高集装袋的导电性能,从而提高其抗静电能力。(The invention relates to a preparation method of a polypropylene-based composite packaging bag material, belonging to the technical field of packaging materials. The polypropylene is a semi-crystalline thermoplastic plastic, has high impact resistance, high mechanical property and toughness, and resists corrosion of various organic solvents and acid and alkali.)

1. A preparation method of a polypropylene-based composite packaging bag material is characterized by comprising the following specific preparation steps:

(1) placing polypropylene particles, modified carbon fibers, nano titanium dioxide powder, sodium stearate and an antioxidant 1010 in a high-speed mixer, and stirring at the rotation speed of 400 ~ 500r/min for 30 ~ 40min at normal temperature to obtain a mixture;

(2) placing the mixture in a double-screw extruder, extruding and granulating at the rotating speed of 100 ~ 120r/min, and cooling at normal temperature to obtain mixed particles;

(3) and (3) placing the mixed particles into an injection molding machine for injection molding to obtain the polypropylene-based composite packaging bag material.

2. The preparation method of the polypropylene-based composite packaging bag material according to claim 1, wherein the weight parts of the polypropylene particles, the modified carbon fibers, the nano titanium dioxide powder, the sodium stearate and the antioxidant 1010 are 60 ~ 80 parts of the polypropylene particles, 18 ~ 24 parts of the modified carbon fibers, 12 ~ 16 parts of the nano titanium dioxide powder, 3 ~ 4 parts of the sodium stearate and 0.6 ~ 0.8.8 parts of the antioxidant 1010.

3. The method for preparing a polypropylene-based composite packaging bag material according to claim 1, wherein the extrusion granulation conditions in the step (2) are a melt temperature of 200 ~ 220 ℃ and a melt pressure of 0.4 ~ 0.6.6 MPa.

4. The method for preparing a polypropylene-based composite packaging bag material according to claim 1, wherein the injection molding conditions in step (3) are a temperature of 180 ~ 200 ℃ and a pressure of 0.6 ~ 0.8.8 MPa.

5. The method for preparing a polypropylene-based composite packaging bag material according to claim 1, wherein the modified carbon fiber obtained in the step (1) is prepared by the following steps:

(1) adding hydrogen peroxide and nitric acid into deionized water, and stirring at the normal temperature at the rotating speed of 180 ~ 200r/min for 10 ~ 12min to obtain an oxidation modified liquid;

(2) adding carbon fiber into the oxidation modified liquid, and stirring for 1 ~ 2h at the rotating speed of 200 ~ 240r/min under the water bath condition of 40 ~ 50 ℃ to obtain a mixed modified liquid;

(3) and placing the mixed modified solution in an ultrasonic dispersion machine, performing ultrasonic dispersion for 20 ~ 30min at normal temperature, filtering, taking a filter cake, washing with deionized water for 3 ~ 5 times, placing in an oven at 60 ~ 80 ℃ for drying for 1 ~ 2h, and cooling at normal temperature to obtain the modified carbon fiber.

6. The method for preparing a polypropylene-based composite packaging bag material according to claim 5, wherein the weight parts of the carbon fiber, the hydrogen peroxide, the nitric acid and the deionized water are 30 ~ 40 parts of the carbon fiber, 12 ~ 16 parts of the hydrogen peroxide, 24 ~ 32 parts of the nitric acid with the mass concentration of 20% and 40 ~ 60 parts of the deionized water.

7. The method for preparing polypropylene-based composite packaging bag material according to claim 5, wherein the power of ultrasonic dispersion in step (3) is 400 ~ 500W.

8. The method for preparing a polypropylene-based composite packaging bag material according to claim 1, wherein the specific preparation steps of the nano titanium dioxide powder in the step (1) are as follows:

(1) adding diethanolamine and absolute ethyl alcohol into deionized water, and stirring at the rotation speed of 180 ~ 200r/min for 10 ~ 12min at normal temperature to obtain a mixed alcohol solution;

(2) slowly adding tetrabutyl titanate into the mixed alcohol solution at the dropping rate of 20 ~ 30mL/min, and violently stirring for 40 ~ 60min at the rotating speed of 600 ~ 640r/min under the water bath condition of 30 ~ 40 ℃ to obtain sol;

(3) cooling the sol to room temperature, adjusting the pH value to 7.8 ~ 8.2.2, and standing at normal temperature for 20 ~ 24h to obtain hydrogel;

(4) drying the hydrogel in an oven at 100 ~ 120 ℃ for 20 ~ 24h to obtain xerogel;

(5) the dried gel is put into a grinding machine and ground for 8 ~ 12h at the normal temperature and the rotating speed of 240 ~ 280r/min, so that dried gel powder is obtained;

(6) and (3) putting the xerogel powder into a muffle furnace, calcining for 1 ~ 2h at the temperature of 600 ~ 800 ℃, and cooling to room temperature along with the furnace to obtain the nano titanium dioxide powder with the average particle size of 20 ~ 30 nm.

9. The method of claim 8, wherein the weight parts of tetrabutyl titanate, diethanolamine, absolute ethanol and deionized water are 20 ~ 30 parts of tetrabutyl titanate, 4 ~ 6 parts of diethanolamine, 20 ~ 30 parts of absolute ethanol and 40 ~ 60 parts of deionized water.

10. The method for preparing a polypropylene-based composite packaging bag material according to claim 8, wherein the pH adjustment in the step (3) is 1% by mass of ammonia water.

Technical Field

The invention relates to a preparation method of a polypropylene-based composite packaging bag material, belonging to the technical field of packaging materials.

Background

Flexible medium bulk containers are generally formed by sewing films, woven fibers, textiles and other flexible materials, and can be provided with linings or inner coatings, auxiliary equipment and loading and unloading devices when necessary. With the increasing degree of mechanical loading and unloading and the improvement of storage conditions, bulk bags have become widely used throughout the world. The production of the flexible freight bags in China mainly starts in the 80 th year of the 20 th century, and is 20 years later than the big outline of the European and American countries, but as the labor cost is continuously increased, the European and American countries gradually stop the production of the flexible freight bags and turn to foreign purchasing, along with the continuous development of the economy of China, and the factors of low labor cost and the like of China, China has become the largest flexible freight bag producing country in the world at present and is also the largest export country in the world at the same time.

The loading capacity of the freight bags for containing the goods is generally over 500kg, and once a safety accident occurs, serious casualties or natural environment damage can be caused, so that the safety of the freight bags is evaluated to be very important, and the safety performance directly influences the safety of loading, unloading and transporting personnel.

The flexible freight bag is a common packaging container for export goods, can be used for containing common goods (non-dangerous goods) and dangerous goods, and has potential danger in the whole service cycle including goods filling, storing, transporting and goods unloading processes. In combination with the characteristics of the bulk bag itself and its environmental analysis of use, the bulk bag presents the following potential hazards over the entire life cycle.

Because bulk bags are often used to contain powders and fine particulates, static electricity is generated by inevitable friction during use. During use, the flexible freight bags are generally subjected to electrostatic hazards in 3 cases: firstly, when goods are filled, the filling materials are generally charged with static electricity in the transmission process, and the goods are filled into the container bag to generate higher volume electric quantity, so that a higher electrostatic field is formed around the container bag; secondly, when the material is unloaded, static electricity is generated due to the friction between the goods and the bag body; third, other operations, such as rubbing against the outer surface of the bulk bag while cleaning or dusting it, can also generate static electricity.

Once static electricity is generated and accumulated as described above, a static discharge condition is created, and friction during transportation causes sparks to be generated on the surface of the bulk bag, thereby causing the contents to ignite or explode. The electrostatic hazard has received considerable attention in the packaging industry, and therefore the antistatic properties of bulk bags are not negligible.

The flexible medium-sized bulk cargo package (flexible freight bag) is required to have certain anti-aging performance because the flexible medium-sized bulk cargo package absorbs ultraviolet rays in sunlight during transportation and storage of the flexible freight bag after the flexible freight bag is filled with cargos, so that the strength of the flexible freight bag is obviously reduced, the phenomena of bag body damage and sling breakage occur, serious accidents such as cargo leakage or personnel injury are caused, and the like, and therefore the anti-aging performance of the flexible medium-sized bulk cargo package is continuously improved in foreign countries, particularly Europe in some countries. The flexible medium-sized bulk cargo package is common in export transportation package, and light aging effect is easy to occur due to sunlight absorption in the transportation and storage processes after the flexible medium-sized bulk cargo package is filled with the bulk cargo, so that the firmness of the flexible medium-sized bulk cargo package is obviously reduced, the phenomena of bag body damage and sling breakage occur, serious accidents such as cargo leakage or personnel injury are caused, and the like, and the flexible medium-sized bulk cargo package is required to have certain ageing resistance.

In conclusion, aiming at the technical problems of the existing flexible freight bags, the antistatic and anti-aging flexible freight bag material is prepared and applied to the field of transportation, and has a promoting effect on import and export trade in China.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the problems that the flexible freight bag can generate static electricity, the photo-aging effect is easy to occur, the strength of the flexible freight bag is obviously reduced, and the bag body is damaged and the hanging strip is broken, the preparation method of the polypropylene-based composite flexible freight bag material is provided.

In order to solve the technical problems, the invention adopts the technical scheme that:

(1) placing polypropylene particles, modified carbon fibers, nano titanium dioxide powder, sodium stearate and an antioxidant 1010 in a high-speed mixer, and stirring at the rotation speed of 400 ~ 500r/min for 30 ~ 40min at normal temperature to obtain a mixture;

(2) placing the mixture in a double-screw extruder, extruding and granulating at the rotating speed of 100 ~ 120r/min, and cooling at normal temperature to obtain mixed particles;

(3) and (3) placing the mixed particles into an injection molding machine for injection molding to obtain the polypropylene-based composite packaging bag material.

The weight parts of the polypropylene particles, the modified carbon fibers, the nano titanium dioxide powder, the sodium stearate and the antioxidant 1010 are 60 ~ 80 parts of the polypropylene particles, 18 ~ 24 parts of the modified carbon fibers, 12 ~ 16 parts of the nano titanium dioxide powder, 3 ~ 4 parts of the sodium stearate and 0.6 ~ 0.8.8 parts of the antioxidant 1010.

The extrusion granulation conditions in the step (2) are that the melt temperature is 200 ~ 220 ℃, and the melt pressure is 0.4 ~ 0.6.6 MPa.

The injection molding conditions in the step (3) are that the temperature is 180 ~ 200 ℃ and the pressure is 0.6 ~ 0.8.8 MPa.

The specific preparation steps of the modified carbon fiber in the step (1) are as follows:

(1) adding hydrogen peroxide and nitric acid into deionized water, and stirring at the normal temperature at the rotating speed of 180 ~ 200r/min for 10 ~ 12min to obtain an oxidation modified liquid;

(2) adding carbon fiber into the oxidation modified liquid, and stirring for 1 ~ 2h at the rotating speed of 200 ~ 240r/min under the water bath condition of 40 ~ 50 ℃ to obtain a mixed modified liquid;

(3) and placing the mixed modified solution in an ultrasonic dispersion machine, performing ultrasonic dispersion for 20 ~ 30min at normal temperature, filtering, taking a filter cake, washing with deionized water for 3 ~ 5 times, placing in an oven at 60 ~ 80 ℃ for drying for 1 ~ 2h, and cooling at normal temperature to obtain the modified carbon fiber.

The weight parts of the carbon fiber, the hydrogen peroxide, the nitric acid and the deionized water are 30 ~ 40 parts, 12 ~ 16 parts, 24 ~ 32 parts, 20% mass concentration nitric acid and 40 ~ 60 parts, respectively.

The power of the ultrasonic dispersion in the step (3) is 400 ~ 500W.

The specific preparation steps of the nano titanium dioxide powder in the step (1) are as follows:

(1) adding diethanolamine and absolute ethyl alcohol into deionized water, and stirring at the rotation speed of 180 ~ 200r/min for 10 ~ 12min at normal temperature to obtain a mixed alcohol solution;

(2) slowly adding tetrabutyl titanate into the mixed alcohol solution at the dropping rate of 20 ~ 30mL/min, and violently stirring for 40 ~ 60min at the rotating speed of 600 ~ 640r/min under the water bath condition of 30 ~ 40 ℃ to obtain sol;

(3) cooling the sol to room temperature, adjusting the pH value to 7.8 ~ 8.2.2, and standing at normal temperature for 20 ~ 24h to obtain hydrogel;

(4) drying the hydrogel in an oven at 100 ~ 120 ℃ for 20 ~ 24h to obtain xerogel;

(5) the dried gel is put into a grinding machine and ground for 8 ~ 12h at the normal temperature and the rotating speed of 240 ~ 280r/min, so that dried gel powder is obtained;

(6) and (3) putting the xerogel powder into a muffle furnace, calcining for 1 ~ 2h at the temperature of 600 ~ 800 ℃, and cooling to room temperature along with the furnace to obtain the nano titanium dioxide powder with the average particle size of 20 ~ 30 nm.

The weight parts of tetrabutyl titanate, diethanolamine, absolute ethyl alcohol and deionized water are 20 ~ 30 parts of tetrabutyl titanate, 4 ~ 6 parts of diethanolamine, 20 ~ 30 parts of absolute ethyl alcohol and 40 ~ 60 parts of deionized water.

And (3) adopting ammonia water with the mass concentration of 1% for pH adjustment.

Compared with other methods, the method has the beneficial technical effects that:

(1) the invention takes polypropylene as a base material and adds modified carbon fiber to prepare a polypropylene-based composite bulk bag material, the polypropylene is a semi-crystalline thermoplastic plastic and has higher impact resistance, strong mechanical property and corrosion resistance to various organic solvents and acid and alkali, the bulk bag material prepared by taking the polypropylene as the base material can effectively improve the comprehensive performance of the bulk bag material, the carbon fiber as a high-performance fiber has a series of excellent performances such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, radiation resistance, electric conduction, heat transfer, shock absorption, noise reduction and the like, the polypropylene in a molten state in the compounding process enters pores of the modified carbon fiber under high pressure after the carbon fiber is modified by nitric acid and hydrogen peroxide, thereby generating a glue nail effect, forming a mosaic structure and a reticular structure form, and effectively improving the combination between the modified carbon fiber and the polypropylene, therefore, the physical and mechanical properties of the bulk bag are effectively improved, in the compounding process, chemical combination between interfaces and physical combination of mutual embedding between materials play an important role in improving the physical and mechanical properties, polypropylene molecules are attracted to the surface of modified carbon fibers, the adsorption force of the polypropylene molecules and the modified carbon fibers is from basic chemical or physical interaction, covalent bonds can be formed in the chemical adsorption process, van der Waals force is generated among the molecules, the molecules of the polypropylene molecules and the modified carbon fibers are in close contact to generate adsorption interaction, the covalent bonds are formed in the interfaces, the mechanical properties and the stability of the bulk bag material are improved, the carbon fibers have excellent conductivity, carriers can be provided for the bulk bag by adding the carbon fibers, the migration of the carriers in the bulk bag composite material is realized through the carbon fibers, and the carbon fibers can form a conductive network in the bulk bag composite material, thereby forming a conductive path in the material, effectively improving the conductive performance of the flexible freight bag and further improving the antistatic capacity of the flexible freight bag;

(2) the invention prepares a polypropylene-based composite packaging bag material by adding nano titanium dioxide powder, wherein the titanium dioxide is an N-type semiconductor material which is nontoxic, high in catalytic activity, strong in oxidation capacity, good in stability and low in price, the nano titanium dioxide has the performances of surface effect, volume effect, quantum size effect, macroscopic quantum tunnel effect and the like, the nano titanium dioxide has strong absorption and scattering capacity to ultraviolet light, in a titanium oxide crystal, titanium ions are positioned in an octahedral center formed by six adjacent oxygen ions, three adjacent titanium atoms are arranged around each oxygen atom, and the three titanium atoms are positioned in three different octahedral centers, as the surface atomic number of the nano titanium dioxide is large, the surface energy is large, a large number of dangling bonds exist on the surface of the nano titanium dioxide, so that electrons and holes can be transferred to the surface of the titanium oxide through transfer, and conduction band electrons and valence band holes in an activated state can be recombined in the titanium dioxide or on the surface, so that the light energy is emitted in the form of heat energy, thereby achieving the effect of shielding ultraviolet rays.

Detailed Description

Weighing 20 ~ 30 parts by weight of tetrabutyl titanate, 4 ~ 6 parts by weight of diethanolamine, 20 ~ 030 parts by weight of anhydrous ethanol and 40 ~ 160 parts by weight of deionized water respectively according to parts by weight, adding diethanolamine and anhydrous ethanol into deionized water, stirring 10 ~ 312min at 180 ~ 2200r/min at normal temperature to obtain a mixed alcohol solution, slowly adding tetrabutyl titanate into the mixed alcohol solution at a dropping rate of 20 ~ 430mL/min, stirring 40 ~ 760min at 600 ~ 6640r/min at a water bath condition of 30 ~ 540 ℃ to obtain a sol, cooling the sol to room temperature, adding 1% by mass of ammonia water to adjust the pH to 7.8 3672.2, standing at room temperature for 20 ~ h to obtain a hydrogel, drying 20 ~ min in an oven with the hydrogel only being 100 ℃ ~ ℃ to obtain a modified nano powder ~ h, placing the dried sol in a 240% by mass concentration of 1% into a double-screw extruder at a rotating speed of ~ h to grind 3672.8.8 h, obtaining a modified nano powder ~ h, placing the modified ~ powder into a dry powder ~ h under 240% of 240% r/min at a dry powder of a dry-200% modified polypropylene powder, placing the dry powder at a dry powder of a dry-200 min under a dry-200-mesh-.