High-friction-coefficient linear low-density polyethylene and preparation method thereof

Abstract

The invention relates to the technical field of polyethylene preparation, in particular to linear low-density polyethylene with a high friction coefficient and a preparation method thereof. The polyethylene is prepared from the following components in parts by mass: 10000 parts of linear low-density polyethylene, 3-7 parts of an antioxidant, 3-7 parts of an acid acceptor, 20-100 parts of an anti-slip agent and 20-100 parts of a dispersing agent. According to the invention, the amount of the added auxiliary agent and the anti-skid component is adjusted, and the auxiliary agent and the anti-skid component have a synergistic effect, so that the friction coefficient of polyethylene is effectively improved under the condition that the mass flow rate, the oxidation resistance, the optical property and the mechanical property of a polyethylene melt are stable.

Description

Technical field:

[0001] The invention relates to the technical field of polyethylene preparation, in particular to a high friction coefficient linear low-density polyethylene and a preparation method thereof. Background technology:

[0002] The coefficient of friction is an important test indicator of polyethylene. GB / T 10006-2021 "Determination of the coefficient of friction of plastic films and sheets" and ISO 8295:1995 "Plastics-Film and Sheeting-Determination of the Coefficients of Friction" provide detailed provisions for the coefficient of friction test.

[0003] In daily use, polyethylene has different requirements for its friction coefficient. Generally, polyethylene with a high friction coefficient can be used to prevent slipping in packaging bag stacking or in conveyor belts for transporting packaging bags.

[0004] Existing methods for preparing high friction coefficient polyethylene include physical methods and chemical methods. Physical methods include printing patterns or protrusions on the surface of polyethylene to increase the friction coefficient. Chemical methods include adding anti-skid / anti-slip components to increase the friction coefficient.

[0005] CN215104383U discloses a polyethylene plate with good anti-skid effect. The main plate and sub-plates of the polyethylene plate are fixed alternately to facilitate the butt joint between the plates. A plurality of anti-skid teeth are fixed on the top of the main plate to solve the anti-skid problem.

[0006] CN108976690A discloses an anti-slip polyethylene material, which includes the following raw material components: modified polyethylene, modified MgTiO4, modified inorganic powder and epoxy-modified polyvinyl chloride paste resin. The polyethylene has anti-slip properties by modifying the raw materials and cooperating with the epoxy-modified polyvinyl chloride paste resin.

[0007] Both the existing physical and chemical methods have their shortcomings. The existing physical methods permanently change the polyethylene surface, and adding patterns or protrusions will cause uneven polyethylene surface performance. Many inorganic additives added by the existing chemical methods are in the form of particles dispersed in the polyethylene resin, which will itself lead to a decrease in the friction coefficient and affect the effectiveness of the anti-slip component that can increase the friction coefficient. Summary of the invention:

[0008] The technical problem to be solved by the present invention is to provide a high friction coefficient linear low-density polyethylene and a preparation method thereof. The polyethylene and the preparation method thereof achieve the synergistic effect of adjusting the amount of added additives and anti-slip components to effectively improve the friction coefficient of the polyethylene while ensuring the stability of the polyethylene melt mass flow rate, antioxidant properties, optical properties and mechanical properties.

[0009] The technical scheme adopted by the present invention is: a high friction coefficient linear low-density polyethylene, which is composed of the following components by mass: 10,000 parts of linear low-density polyethylene, 3-7 parts of antioxidant, 3-7 parts of acid absorber, 20-100 parts of anti-slip agent, and 20-100 parts of dispersant.

[0010] Furthermore, the linear low-density polyethylene is a polyethylene powder without any processing aid added, and the density is 0.920±0.002g / cm 3 , the melt mass flow rate is 0.8-2.2g / 10min.

[0011] Furthermore, the antioxidant is a mixture of antioxidant 1076 and antioxidant 168, wherein, by weight, antioxidant 168 is 1-4 parts and antioxidant 1076 is 2-3 parts.

[0012] Furthermore, the acid absorber is zinc stearate.

[0013] Furthermore, the anti-slip agent is polyisobutylene with a molecular weight of 4000-5000.

[0014] Furthermore, the dispersant is polyethylene wax.

[0015] A method for preparing linear low-density polyethylene with a high friction coefficient comprises the following steps: accurately weighing linear low-density polyethylene powder, antioxidant, acid absorber, anti-slip agent and dispersant, adding them into a high-speed mixer for mixing, adding them into a twin-screw extruder for extrusion after mixing, and cutting the extruded strips into pellets after water cooling to obtain linear low-density polyethylene pellets with a high friction coefficient.

[0016] Furthermore, the materials put into the high-speed mixer are mixed for 3-5 minutes.

[0017] Furthermore, when the twin-screw extruder is in extrusion operation, the screw temperature is 160-180° C. and the screw speed is 100 rpm.

[0018] The beneficial effect of the present invention is that the present invention realizes that by adjusting the amount of the added auxiliary agent and the anti-slip component, the two work synergistically, and the friction coefficient of polyethylene is effectively improved while ensuring the stability of the polyethylene melt mass flow rate, antioxidant properties, optical properties and mechanical properties. Specific implementation method:

[0019] The present invention will be further described with reference to the embodiments.

[0020] The prepared pellets were subjected to melt mass flow rate test according to the standard method of Part 1 of GB / T3682.1-2018 "Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastics thermoplastics".

[0021] The prepared pellets were subjected to oxidation induction time (OIT) test according to GB / T 19466.6-2009 "Plastics Differential Scanning Calorimetry (DSC)" Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT).

[0022] The prepared film was subjected to friction coefficient test according to GB / T 10006-2021 “Determination of friction coefficient of plastic films and sheets”.

[0023] The prepared film was tested for light transmittance according to GB / T2410-2008 “Determination of light transmittance and haze of transparent plastics”.

[0024] The prepared films were subjected to mechanical property tests according to GB / T 17037.1-2019 "Preparation of injection molding specimens of plastics and thermoplastic materials" Part 1: General principles and preparation of multi-purpose specimens and long strip specimens and GB / T 17037.3-2003 "Preparation of injection molding specimens of plastics and thermoplastic materials" Part 3: Small square test pieces. The tensile strength and elongation at break were tested in accordance with GB / T1040.1-2018 "Determination of tensile properties of plastics" Part 1: General principles and GB / T 1040.2-2022 "Determination of tensile properties of plastics" Part 2: Test conditions for molded and extruded plastics.

[0025] Examples 1-6 and Comparative Examples 1-2 were tested according to the following steps:

[0026] The components in Examples 1-6 and Comparative Examples 1-2 were accurately weighed and put into a high-speed mixer for mixing for 3-5 minutes. After mixing, they were added to a twin-screw extruder for extrusion. The screw temperature was 160-180°C and the screw speed was 100 rpm. The extruded strips were water-cooled and pelletized to obtain linear low-density polyethylene pellets with a high friction coefficient.

[0027] The prepared high friction coefficient linear low-density polyethylene pellets are dried and dehydrated, and then the melt mass flow rate and oxidation induction time are tested. At the same time, a film blowing experiment is carried out on the pellets using a film blowing machine with a screw temperature of 160-180°C to prepare polyethylene films, and the friction coefficient, optical properties and mechanical properties of the films are tested.

[0028] Examples 1-6 and Comparative Examples 1-2 were implemented according to the proportions in Table 1.

[0029] Table 1 Proportions of Examples 1-6 and Comparative Examples 1-2 (in parts by mass)

[0030] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Polyethylene powder A 10000 10000 10000 0 0 0 10000 0 Polyethylene powder B 0 0 0 10000 10000 10000 0 10000 Antioxidant 168 2 1 4 2 1 4 0 0 Antioxidant 1076 3 2 3 3 2 3 0 0 Zinc stearate 3 4 7 3 4 7 0 0 Polyisobutylene 20 60 100 20 60 100 0 0 Polyethylene wax 20 60 100 20 60 100 0 0 Mixing time 3 4 5 3 4 5 4 4 Screw temperature 160 165 170 175 180 180 175 175

[0031] The polyethylene powder A is a linear low-density polyethylene with a density of 0.918 g / cm 3 , the melt mass flow rate (MFR) is 2.2 g / 10 min.

[0032] Polyethylene powder B is linear low-density polyethylene with a density of 0.922 g / cm 3 , the melt mass flow rate (MFR) is 0.8 g / 10 min.

[0033] The test results are averaged and are shown in Table 2.

[0034] Table 2 Test results of Examples 1-6 and Comparative Examples 1-2

[0035]

[0036] As shown in Table 2, compared with Comparative Examples 1-2, Examples 1-6, by adjusting the amount of the added additives and anti-slip components, the two work synergistically to effectively improve the friction coefficient of polyethylene while ensuring the stability of the polyethylene melt mass flow rate, antioxidant properties, optical properties and mechanical properties.

[0037] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A high friction coefficient linear low density polyethylene, Features: The invention is composed of the following components by weight: 10,000 parts of linear low-density polyethylene, 3-7 parts of antioxidant, 3-7 parts of acid absorbent, 20-100 parts of anti-slip agent and 20-100 parts of dispersant.

2. The high friction coefficient linear low density polyethylene according to claim 1, Features: The linear low-density polyethylene is a polyethylene powder without any processing aid added, and the density is 0.920±0.002g / cm 3 , the melt mass flow rate is 0.8-2.2g / 10min.

3. The high friction coefficient linear low density polyethylene according to claim 1, Features: The antioxidant is a mixture of antioxidant 1076 and antioxidant 168, wherein, by weight, antioxidant 168 accounts for 1-4 parts and antioxidant 1076 accounts for 2-3 parts.

4. The high friction coefficient linear low density polyethylene according to claim 1, Features: The acid absorber is zinc stearate.

5. The high friction coefficient linear low density polyethylene according to claim 1, Features: The anti-slip agent is polyisobutylene with a molecular weight of 4000-5000.

6. The high friction coefficient linear low density polyethylene according to claim 1, Features: The dispersant is polyethylene wax.

7. A method for preparing a high friction coefficient linear low density polyethylene according to claim 1, Features: The method comprises the following steps: accurately weighing linear low-density polyethylene powder, antioxidant, acid absorbent, anti-slip agent and dispersant, adding them into a high-speed mixer for mixing, adding them into a twin-screw extruder for extrusion after mixing, and pelletizing the extruded strips after water cooling to obtain linear low-density polyethylene pellets with high friction coefficient.

8. The method for preparing a high friction coefficient linear low density polyethylene according to claim 7, Features: The materials put into the high-speed mixer are mixed for 3-5 minutes.

9. The method for preparing a high friction coefficient linear low density polyethylene according to claim 7, Features: When the twin-screw extruder is in extrusion operation, the screw temperature is 160-180° C. and the screw speed is 100 rpm.

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