阅读说明：本技术 阻燃抗静电滚塑聚烯烃组合物及其制备方法 (Flame-retardant antistatic rotational molding polyolefin composition and preparation method thereof ) 是由 张广明 刘少成 张超 裴晓静 *** 徐素兰 于 2018-07-16 设计创作，主要内容包括：本发明涉及一种聚烯烃组合物,具体涉及一种阻燃抗静电滚塑聚烯烃组合物及其制备方法。所述的组合物,包括如下原料：聚乙烯100份；阻燃抗静电母料20-40份；其中,所述的聚乙烯为乙烯与1-己烯的共聚物；所述的阻燃抗静电母料包括复合阻燃剂、复合抗静电剂及助剂,由如下重量份数的原料制成：复合阻燃剂40-80份；复合抗静电剂10-40份；超支化聚乙烯5-10份；交联剂0.05-0.2份；硅烷0.25-1.0份；抗氧剂0.5-5份；α-甲基苯乙烯共聚物2-8份。本发明组合物具有良好的滚塑加工性能、阻燃性能、抗静电性能及物理机械性能,能够用于滚塑制品的生产,制品内外表面光滑,塑化良好；所述的制备方法简单易行。(The invention relates to a polyolefin composition, in particular to a flame-retardant antistatic rotational molding polyolefin composition and a preparation method thereof. The composition comprises the following raw materials: 100 parts of polyethylene; 20-40 parts of flame-retardant antistatic master batch; wherein the polyethylene is a copolymer of ethylene and 1-hexene; the flame-retardant antistatic master batch comprises a composite flame retardant, a composite antistatic agent and an auxiliary agent, and is prepared from the following raw materials in parts by weight: 40-80 parts of a composite flame retardant; 10-40 parts of a composite antistatic agent; 5-10 parts of hyperbranched polyethylene; 0.05-0.2 part of cross-linking agent; 0.25-1.0 part of silane; 0.5-5 parts of antioxidant; 2-8 parts of alpha-methyl styrene copolymer. The composition has good rotational molding processability, flame retardant property, antistatic property and physical and mechanical properties, can be used for producing rotational molding products, and has smooth inner and outer surfaces and good plasticization; the preparation method is simple and feasible.)

1. A flame retardant antistatic rotomoulding polyolefin composition characterized by: the composite material comprises the following raw materials in parts by weight:

100 parts of polyethylene;

20-40 parts of flame-retardant antistatic master batch;

wherein the polyethylene is a copolymer of ethylene and 1-hexene, the melt mass flow rate is 4-7g/10min, and the density is 0.930-0.943g/cm³The weight average molecular weight is 7-9 ten thousand, and the molecular weight distribution is 2-3.5;

the flame-retardant antistatic master batch comprises a composite flame retardant, a composite antistatic agent and an auxiliary agent, and is prepared from the following raw materials in parts by weight:

the composite flame retardant consists of red phosphorus, resorcinol bis (diphenyl phosphate), ammonium polyphosphate and aluminum hydroxide;

the composite antistatic agent consists of a dupont entira as ionomer antistatic agent, polyvinyl alcohol and an antistatic agent HZ-1.

2. A flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the mass ratio of the red phosphorus, the resorcinol bis (diphenyl phosphate), the ammonium polyphosphate and the aluminum hydroxide is 1: 1-2: 1-2: 1-3.

3. A flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the mass ratio of the dupont ntara as ionomer antistatic agent to the polyvinyl alcohol to the antistatic agent HZ-1 is 4: 1: 1.

4. a flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the mass ratio of the composite flame retardant to the composite antistatic agent is 1.5-4: 1.

5. a flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the hyperbranched polyethylene is white arm-shaped polyamide hyperbranched polymer.

6. A flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the cross-linking agent is a peroxide cross-linking agent.

7. A flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the silane is liquid unsaturated siloxane.

8. A flame retardant antistatic rotomoulding polyolefin composition according to claim 1 characterized in that: the antioxidant is a mixture of hindered phenol antioxidant and phosphite antioxidant.

9. A flame retardant antistatic rotomoulding polyolefin composition according to claim 8 characterized in that: the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1: 1.

10. a process for the preparation of a flame retardant antistatic rotomoulding polyolefin composition according to any one of claims 1 to 9, characterized in that: the method comprises the following steps:

(1) uniformly mixing hyperbranched polyethylene, a cross-linking agent and part of silane to obtain a mixture A;

(2) placing red phosphorus, ammonium polyphosphate and aluminum hydroxide in a high-speed mixer, uniformly mixing, adding the rest silane, adding resorcinol bis (diphenyl phosphate) and alpha-methyl styrene copolymer when the temperature reaches 100 ℃, uniformly mixing, and discharging to obtain a mixture B;

(3) putting the mixture B into a powder stirrer, adding the mixture A, mixing for 5-10 minutes, adding the composite antistatic agent, and discharging for later use to obtain a mixture C;

(4) placing polyethylene in a high-speed stirrer, adding an antioxidant, mixing, adding the mixture C, and mixing at a stirring speed of 600-;

(5) adding the mixture D into a double-screw extruder, and melting, plasticizing, extruding and granulating; the length-diameter ratio of the screw of the extruder is not less than 20, and the temperature of the resin melt is 160-180 ℃.

Technical Field

The invention relates to a polyolefin composition, in particular to a flame-retardant antistatic rotational molding polyolefin composition and a preparation method thereof.

Background

Polyethylene has excellent comprehensive performance, is the most main raw material for rotational molding processing, and the application field of rotational molding products is more extensive. The requirements of people on daily life can be met, the requirements under specific conditions can be met, and in the prior art, universal rotational molding raw materials are used for processing according to the shape of a mold. However, under the harsh conditions of use, the properties such as flame retardance, antistatic property and the like are greatly limited. The common products can not meet the use requirements, and modification is needed to improve the performance. With the increasing related fields of rotational molding products, flame-retardant antistatic raw materials are urgently needed in the rotational molding industry to meet the requirements of certain industries on flame retardance and antistatic property of the products, such as packaging boxes, electrical equipment shells and the like, but related researches are few.

The traditional polyolefin flame-retardant mode has the disadvantages of large dosage of added flame retardant, more product performance reduction, no suitability for rotational molding processing and no suitability for rotational molding product production. The same problem exists in the antistatic aspect, the rotational molding processing temperature is as high as 280 ℃, the time is as long as 40 minutes, the common antistatic agent is easy to decompose and lose the antistatic effect, and the special permanent antistatic agent has good effect, large addition amount and high cost, and is difficult to popularize and use.

Patent CN201710160737.3 discloses a halogen-free flame-retardant antistatic polyethylene composition special for rotational molding and a preparation method thereof, the composition is composed of LLDPE, LDPE and halogen-free flame-retardant antistatic master batch, and the halogen-free flame-retardant antistatic master batch is composed of conductive carbon black, expandable graphite, phosphorus-nitrogen expansion type flame retardant, antistatic agent, coupling agent, toughening agent, PE wax and antioxidant. The disclosed composition, to which a large amount of inorganic components is added, causes a decrease in strength of the composition, and its technical solution is different from the present invention.

Patent CN201710154262.7 discloses a composite material special for military rotational molding ammunition packaging and a preparation method thereof, wherein the composite material consists of LLDPE, HDPE, melamine formaldehyde resin MF, a cross-linking agent, nano reinforcing particles and a nucleating agent. The basic resin of the invention is LLDPE and HDPE, the flame retardant is melamine formaldehyde resin, and the technical scheme is different from the patent.

Disclosure of Invention

The invention aims to provide a flame-retardant antistatic rotational molding polyolefin composition, which has good rotational molding processability, flame retardant property, antistatic property and physical and mechanical properties under the condition of lower addition of flame retardant and antistatic agent, and can be used for producing rotational molding products, wherein the produced rotational molding products have smooth inner and outer surfaces and good plasticization; the invention also provides a preparation method of the composition, which is scientific, reasonable, simple and feasible.

The flame-retardant antistatic rotational molding polyolefin composition comprises the following raw materials in parts by weight:

100 parts of polyethylene;

20-40 parts of flame-retardant antistatic master batch;

wherein the polyethylene is a copolymer of ethylene and 1-hexene, the melt mass flow rate is 4-7g/10min, and the density is 0.930-0.943g/cm³The weight average molecular weight is 7-9 ten thousand, and the molecular weight distribution is 2-3.5;

the flame-retardant antistatic master batch comprises a composite flame retardant, a composite antistatic agent and an auxiliary agent, and is prepared from the following raw materials in parts by weight:

the composite flame retardant consists of red phosphorus, resorcinol bis (diphenyl phosphate), ammonium polyphosphate and aluminum hydroxide;

the composite antistatic agent consists of a dupont entira as ionomer antistatic agent, polyvinyl alcohol and an antistatic agent HZ-1.

The mass ratio of the red phosphorus, the resorcinol bis (diphenyl phosphate), the ammonium polyphosphate and the aluminum hydroxide is 1: 1-2: 1-2: 1-3. Wherein the red phosphorus has a density of 2.34g/cm³The particle size is 800-; ammonium polyphosphate, the phosphorus content is 30-32%; the polymerization degree is more than 1000, and the particle size is 2000 meshes; aluminum hydroxide, relative density 2.42g/cm³The particle size is 2000-5000 meshes; resorcinol bis (diphenylphosphate) having a density of 1.3g/cm³And phosphorus content 10%.

The mass ratio of the dupont entira as ionomer antistatic agent to the polyvinyl alcohol to the antistatic agent HZ-1 is 4: 1: 1. the Dupont entira as ionomer type antistatic agent has a density of about 0.985g/cm³The antistatic agent can be distributed in a product in a net shape to achieve a permanent antistatic effect; polyvinyl alcohol, powder, density 1.27-1.31, molecular weight 6-20 ten thousand; HZ-1 bulk density 0.3-0.5, thermal stability greater than 300 ℃, melting point: at 45 ℃.

The mass ratio of the composite flame retardant to the composite antistatic agent is 1.5-4: 1.

the hyperbranched polyethylene is white arm-shaped polyamide hyperbranched polymer. The polymer contains a long polyvinyl alkyl main chain part, the end group comprises two functional groups of an amino group and an ester group, the Mw molecular weight is 4000-20000 measured by a GPC method, and the branching degree is 20-100 measured by infrared spectrum.

The cross-linking agent is peroxide cross-linking agent, the temperature with half-life period of 1min is 170-270 ℃, such as dicumyl peroxide, 2, 5-dimethyl-2, 5-di-tert-butyl peroxy hexane, 2, 5-dimethyl-2, 5-di-tert-butyl peroxy-3-hexyne and the like.

The silane is liquid unsaturated siloxane. Such as vinyltriethoxysilane, vinyltrimethoxysilane or a blend of the two in any proportion.

The antioxidant is a mixture of hindered phenol antioxidant and phosphite antioxidant.

The mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1: 1.

the softening point of the alpha-methylstyrene copolymer is 90 ℃, the molecular weight is 689, and the volatile matter is 0.5%.

The formula can also be added with proper amount of assistants such as ultraviolet absorbent, processing aid, colorant and the like, and the effect of the invention is not influenced.

The preparation method of the flame-retardant antistatic rotational molding polyolefin composition comprises the following steps:

(1) uniformly mixing hyperbranched polyethylene, a cross-linking agent and part of silane to obtain a mixture A;

(2) placing red phosphorus, ammonium polyphosphate and aluminum hydroxide in a high-speed mixer, uniformly mixing, adding the rest silane, adding resorcinol bis (diphenyl phosphate) and alpha-methyl styrene copolymer when the temperature reaches 100 ℃, uniformly mixing, and discharging to obtain a mixture B;

(3) putting the mixture B into a powder stirrer, adding the mixture A, mixing for 5-10 minutes, adding the composite antistatic agent, and discharging for later use to obtain a mixture C;

(4) placing polyethylene in a high-speed stirrer, adding an antioxidant, mixing, adding the mixture C, and mixing at a stirring speed of 600-;

(5) adding the mixture D into a double-screw extruder, and melting, plasticizing, extruding and granulating; the length-diameter ratio of the screw of the extruder is not less than 20, and the temperature of the resin melt is 160-180 ℃.

The mass of the silane adopted in the step (2) accounts for one tenth of the total mass of the silane.

The invention has the following beneficial effects:

1. under the condition of lower addition of the flame retardant and the antistatic agent, the composition has good rotational molding processability, flame retardant property, antistatic property and physical and mechanical properties, and can be used for producing rotational molding products, and the produced rotational molding products have smooth inner and outer surfaces and good plasticization.

2. The preparation method is simple and easy to implement and is easy to realize.

Drawings

FIG. 1 is a schematic flow diagram of a preparation method of a flame retardant antistatic rotomolding polyolefin composition according to the present invention.

Detailed Description

The present invention is further described below with reference to examples.