Polyethylene composition for rotomoulding and its preparation method

A technology of polyethylene and composition, which is applied in the field of polyethylene composition for rotational molding and its preparation, to achieve the effects of good plasticization, simple process, and easy industrial production

Active Publication Date: 2017-12-08
CHINA PETROLEUM & CHEM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although its polyethylene is homogeneous, its density is 0.930-0.944g / cm 3 (Preferably 0.933~0.941g / cm 3 ), the impact strength is only 9~22kJ / m 2

Method used

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  • Polyethylene composition for rotomoulding and its preparation method
  • Polyethylene composition for rotomoulding and its preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] The preparation method of the titanium-containing catalyst comprises the following steps:

[0050] (a) 100kg of carrier silica gel was activated, the activation temperature was 500°C, the activation time was 10h, and the specific surface area of ​​the carrier silica gel was 300m 2 / g;

[0051] (b) in step (a), put 1000 mol of alkyl aluminum into the treatment, the treatment temperature is 80 ° C, the treatment is carried out for 6 hours, and the powder is dried;

[0052] (c) adding premixed 5000mol tetrahydrofuran, 500mol magnesium chloride and 1mol titanium trichloride to the powder prepared in step (b), stirring, drying, and the ratio of magnesium to titanium is 2~4;

[0053] (d) adding 0.1 mol of monochloroethylaluminum and 10 mol of di-n-hexylaluminum, stirring for 20 min, and drying to obtain a titanium-containing catalyst a.

[0054] The preparation method of the described polyethylene composition for rotational molding, comprises the following steps:

[0055] ...

Embodiment 2

[0059] The preparation method of the titanium-containing catalyst comprises the following steps:

[0060] (a) 100kg of carrier silica gel was activated, the activation temperature was 800°C, the activation time was 5h, and the specific surface area of ​​the carrier silica gel was 600m 2 / g;

[0061] (b) In step (a), 10 mol of alkyl aluminum is put into the treatment, the treatment temperature is 60 ° C, the treatment is carried out for 10 h, and the powder is dried;

[0062] (c) adding premixed 100mol tetrahydrofuran, 1mol magnesium chloride and 500mol titanium trichloride to the powder prepared in step (b), stirring and drying, and the ratio of magnesium to titanium is 2~4;

[0063] (d) adding 10 mol of monochloroethylaluminum and 0.1 mol of di-n-hexylaluminum, stirring for 50 min, and drying to obtain titanium-containing catalyst b.

[0064] The preparation method of the described polyethylene composition for rotational molding, comprises the following steps:

[0065] (1)...

Embodiment 3-5

[0069] Examples 3-5 were all prepared using the same catalyst and preparation process as in Example 1, the only difference being that the used polymerization monomers were different, as shown in Table 1 for details.

[0070] The properties of the polyethylene resin compositions prepared in Examples 1-5 are shown in Table 1.

[0071] Test method for retention rate of elongation at break: UV aging test is carried out with injection-molded tensile specimen, UV lamp is 313B type, and the irradiation intensity is 0.71W / m 2 / nm, illuminated at 60°C for 4 hours, and condensed at 50°C for 4 hours, and so on.

[0072] Table 1 Properties of the polyethylene resin compositions prepared in Examples 1-5

[0073]

[0074]

[0075] Note: The rotomolding equipment is electric heating, the process of rotomolding products is heating chamber temperature 260℃, heating time 30min, cooling time 25min, product size 500mm×500mm×250mm, product thickness 4mm.

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Abstract

The invention relates to a polyethylene polymer, in particular to a polyethylene composition for rotational molding. Including polyethylene, the polymerization monomer of polyethylene is: ethylene unit with a volume fraction of 90-98%; 1-butene or 1-hexene copolymerized unit with a volume fraction of 2-10%. The melt mass flow rate of the polyethylene is 3-7g / 10min, the density is 0.940-0.950g / cm3, the weight-average molecular weight is 8-100,000, the molecular weight distribution is 4.0-5.0, and the relative branching degree is 0.1- 0.5, and the crystallization temperature is 112.5-114.5°C. The invention improves the rigidity and strength of raw materials while ensuring good impact and environmental stress cracking resistance, and the produced rotomolded products have high rigidity and toughness, smooth inner and outer surfaces, and good plasticization; the invention also provides The preparation method thereof is provided, and the process is simple and easy for industrialized production.

Description

technical field [0001] The invention relates to a polyethylene polymer, in particular to a polyethylene composition for rotational molding and a preparation method thereof. Background technique [0002] The rotational speed of the mold in rotational molding is very low. At a very low speed, the plastic raw material is always kept at the bottom of the cavity under the action of gravity. As the hot mold rotates, the plastic raw material flows continuously. When the mold is heated to a certain degree, the plastic material begins to adhere to the inner surface of the cavity. The thin layers of plastic stock that have adhered to the mold cavity are further heated and fuse together to form the desired shape. [0003] Since medium-density linear polyethylene (LLDPE) has good rotomolding performance and comprehensive physical properties, more than 90% of the raw materials used for rotomolding are LLDPE. The flexural modulus of LLDPE is generally 300-500MPa, and the tensile yield ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08L23/08C08F210/16C08F4/645C08K13/02C08K5/3492C08K3/22C08K5/098C08K5/134C08K5/526
Inventor 刘少成张超张广明徐素兰裴小静霍明胡军
Owner CHINA PETROLEUM & CHEM CORP
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