阅读说明：本技术 一种抗低温脆性的pvc-u阻燃电工套管及其制备方法 (Low-temperature brittleness resistant PVC-U flame-retardant electrical casing and preparation method thereof ) 是由 陈国焜 谭长春 吴晓芸 韩莎莎 于 2020-06-10 设计创作，主要内容包括：发明人提供了种抗低温脆性的PVC-U阻燃电工套管及其制备方法,所述PVC-U阻燃电工套管由PVC树脂、碳酸钙填充料、复合稳定剂、乙烯醋酸乙烯共聚物、丙烯腈-丁二烯-苯乙烯共聚物、CPE抗冲改性剂、ACR抗冲击改性剂、钛白粉、改质剂、润滑剂混合,形成多元混合物,该组分配方使产品具有较好的强度、较好的韧性和较好的低温脆性,抗冲性和抗压性的都得到提高。(The invention provides a low-temperature brittleness resistant PVC-U flame-retardant electrical casing and a preparation method thereof, wherein the PVC-U flame-retardant electrical casing is prepared by mixing PVC resin, calcium carbonate filler, composite stabilizer, ethylene vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, CPE impact modifier, ACR impact modifier, titanium dioxide, modifier and lubricant to form a multi-component mixture, and the formula of the components enables the product to have better strength, better toughness and better low-temperature brittleness, and the impact resistance and the pressure resistance are improved.)

1. The PVC-U flame-retardant electrical casing pipe resistant to low-temperature brittleness is characterized by comprising the following components in parts by mass:

2. the PVC-U flame retardant electrical bushing as recited in claim 1, wherein the degree of polymerization of the PVC resin is 1000-1200.

3. The PVC-U flame retardant electrical bushing according to claim 1, wherein the composite stabilizer is one of composite lead stabilizer, organic tin stabilizer or a mixture thereof.

4. The PVC-U flame retardant electrical bushing according to claim 1, wherein the CPE impact modifier has a chlorine content of 34.5 to 36 wt%.

5. The PVC-U flame retardant electrical bushing according to claim 1, wherein the ethylene vinyl acetate copolymer has a vinyl acetate content of 18-24 wt%.

6. The PVC-U flame retardant electrical bushing according to claim 1, wherein the titanium white is rutile type titanium white.

7. The PVC-U flame retardant electrical bushing according to claim 1, wherein the lubricant is one of paraffin wax, polyethylene wax, oxidized polyethylene wax, stearic acid, mono anhydride ester or a mixture thereof.

8. The preparation method of the PVC-U flame-retardant electrical casing is characterized by comprising the following steps of:

the components and the weight portion ratio according to any one of claims 1 to 7 are sequentially added into a mixer for stirring at the stirring speed of 300r/min to 500r/min, wherein the mixer comprises PVC resin, calcium carbonate filler, composite stabilizer, ethylene vinyl acetate copolymer, CPE impact modifier, ACR impact modifier, titanium pigment, modifier and lubricant; and in the stirring process, heating and hot mixing are carried out at the heating rate of 2-5 ℃/min, the temperature is reduced at the speed of 4-7 ℃/min after being increased to 120 ℃, the temperature is reduced to 45 ℃ to obtain a mixture, and the PVC-U flame-retardant electrical casing is obtained after extrusion molding, vacuum cooling, traction and cutting by adopting a screw extruder.

9. The method for preparing a PVC-U flame retardant electrical bushing according to claim 8, wherein the barrel temperature of the screw extruder is 170 ℃ to 190 ℃ and the die temperature is 160 ℃ to 210 ℃.

Technical Field

The invention relates to the field of building materials, in particular to a PVC-U flame-retardant electrical casing pipe resistant to low-temperature brittleness and a preparation method thereof.

Background

With the rapid development of the building industry, 90 percent of building drainage pipelines in 2010 adopt plastic pipes; 85% of the building rainwater drainage pipeline adopts a plastic pipe; the building threading protective sleeve is made of plastic pipes, and the PVC-U drainage pipe has the advantages of relatively high strength, relatively low price, light weight, durability, easiness in processing, high cost performance and the like, is listed as four-pillar material in the building industry with steel, wood and cement, is widely applied to the building industry, and various novel PVC flame-retardant products are continuously produced.

However, the PVC resin has poor thermal stability and toughness (anti-extrusion property), particularly poor low-temperature toughness and low-temperature impact resistance, and rapidly decreases with the decrease of temperature, and becomes brittle at a temperature lower than 5 ℃, so that the PVC resin is brittle under slight impact, and the service performance and the use field of the PVC resin are seriously influenced.

At present, most PVC-U flame-retardant electrical sleeves have the problem, and many manufacturers adopt two formulas of winter and summer to solve the problem, but the effect is limited, and if other toughening technologies are used for solving the problem, the market price is limited, and the problem cannot be realized.

Disclosure of Invention

Therefore, the PVC-U flame-retardant electrical casing pipe resistant to low-temperature brittleness and the preparation method thereof are needed to be provided. In a first aspect of the present invention, the inventors provide a low temperature brittleness resistant PVC-U flame retardant electrical casing, which is composed of the following components in parts by mass:

to achieve the object of the second aspect of the present invention, the inventors provide a method for preparing a PVC-U flame retardant electrical conduit, comprising the steps of: according to the components and weight parts of the PVC-U flame-retardant electrical casing provided by the first aspect of the invention, PVC resin, calcium carbonate filler, composite stabilizer, ethylene vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, CPE impact modifier, ACR impact modifier, titanium dioxide, modifier and lubricant are sequentially added into a mixer for stirring, wherein the stirring speed is 300r/min-500 r/min; and in the stirring process, heating and hot mixing are carried out at the heating rate of 2-5 ℃/min, the temperature is reduced at the speed of 4-7 ℃/min after being increased to 120 ℃, the temperature is reduced to 45 ℃ to obtain a mixture, and the PVC-U flame-retardant electrical casing is obtained after extrusion molding, vacuum cooling, traction and cutting by adopting a screw extruder.

Different from the prior art, the technical scheme adopts PVC resin, calcium carbonate filling material, ethylene vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, CPE impact modifier, ACR impact modifier and other components to be blended to form a multi-component mixture, and the formula of the components ensures that the product has better strength, better toughness and better low-temperature brittleness, and the impact resistance and the pressure resistance are improved.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the technical means in detail, the following detailed description is given with reference to specific embodiments.

First, a PVC-U flame retardant electrical bushing against low temperature brittleness according to a first aspect of the present invention is explained, which is composed of the following components in parts by mass:

further, the polymerization degree of the PVC resin is 1000-1200, and a PVC 5 type resin can be selected.

Further, the calcium carbonate filler is light calcium carbonate.

Further, the composite stabilizer is one or a mixture of a composite lead stabilizer and an organic tin stabilizer.

Further, the CPE impact modifier has a chlorine content of 34.5 to 36 wt%.

Furthermore, the content of vinyl acetate in the ethylene-vinyl acetate copolymer is 18-24 wt%.

Further, the titanium dioxide is rutile type titanium dioxide.

Further, the lubricant is one of paraffin, polyethylene wax, oxidized polyethylene wax, stearic acid, and monoanhydride ester or a mixture thereof.

Next, a method for preparing a PVC-U flame retardant electrical casing according to a second aspect of the present invention is described, comprising the steps of:

according to the components and the weight ratio of the first aspect of the invention, PVC resin, calcium carbonate filler, composite stabilizer, ethylene vinyl acetate copolymer, CPE impact modifier, ACR impact modifier, titanium pigment, modifier and lubricant are added into a mixer in sequence and stirred at the stirring speed of 300r/min-500 r/min; and in the stirring process, heating and hot mixing are carried out at the heating rate of 2-5 ℃/min, the temperature is reduced at the speed of 4-7 ℃/min after being increased to 120 ℃, the temperature is reduced to 45 ℃ to obtain a mixture, and the PVC-U flame-retardant electrical casing is obtained after extrusion molding, vacuum cooling, traction and cutting by adopting a double-screw extruder.

Further, the barrel temperature of the screw extruder is 170-190 ℃, and the die temperature is 160-200 ℃.

In this embodiment, the ethylene vinyl acetate copolymer has a vinyl acetate content of 18 to 24 wt% and the CPE impact modifier has a chlorine content of 34.5 to 36 wt%. The modifier was purchased from Nanjing collaborative chemical, Inc., model XH-CB 22.