阅读说明：本技术 一种高阻燃抑烟pvc-u绝缘电工套管及其制备方法 (High-flame-retardance smoke-suppression PVC-U insulating electrical casing and preparation method thereof ) 是由 李文权 彭伏弟 陈晓梅 高洁 林知 马鑫 于 2021-07-29 设计创作，主要内容包括：本发明公开了一种高阻燃抑烟PVC-U绝缘电工套管及其制备方法,由按如下质量份数的原料组成：PVC SG-5：100份,钙锌稳定剂：3～5份,微晶蜡：1～3份,轻质碳酸钙：10～20份,有机蒙脱土(OMMT)：2～10份,水滑石(LDHS)：2～10份,钛白粉：0.1～1份,CPE(氯化聚乙烯)：2～5份,ACR(丙烯酸酯类)：1～5份,荧光增白剂KB：0.01份。本方明的PVC-U绝缘电工套管在保证了拉伸强度和常温缺口冲击强度下,显著提高了弯曲强度,还具有优异的阻燃性能和抑烟性能。(The invention discloses a high-flame-retardance smoke-suppression PVC-U insulating electrical casing and a preparation method thereof, wherein the high-flame-retardance smoke-suppression PVC-U insulating electrical casing is composed of the following raw materials in parts by mass: PVC SG-5: 100 parts of calcium-zinc stabilizer: 3-5 parts of microcrystalline wax: 1-3 parts of light calcium carbonate: 10-20 parts of organic montmorillonite (OMMT): 2-10 parts of hydrotalcite (LDHS): 2-10 parts of titanium dioxide: 0.1-1 part, CPE (chlorinated polyethylene): 2-5 parts, ACR (acrylate): 1-5 parts of fluorescent whitening agent KB: 0.01 part. The PVC-U insulating electrical casing pipe obviously improves the bending strength under the condition of ensuring the tensile strength and the notch impact strength at normal temperature, and also has excellent flame retardant property and smoke suppression property.)

1. A high-flame-retardance smoke-suppression PVC-U insulating electrical casing is characterized by comprising the following raw materials in percentage by mass: PVC SG-5: 100 parts of calcium-zinc stabilizer: 3-5 parts of microcrystalline wax: 1-3 parts of light calcium carbonate: 10-20 parts of organic montmorillonite (OMMT): 2-10 parts of hydrotalcite (LDHS): 2-10 parts of titanium dioxide: 0.1-1 part, CPE (chlorinated polyethylene): 2-5 parts, ACR (acrylate): 1-5 parts of fluorescent whitening agent KB: 0.01 part.

2. The high flame retardant smoke suppressing PVC-U insulating electrical bushing according to claim 1, wherein the organic montmorillonite (OMMT) is Modified Montmorillonite (MMT).

3. The high flame retardant and smoke suppressant PVC-U insulating electrical bushing as recited in claim 1 wherein said OMMT and LDHs have a synergistic effect which increases the flame retardant properties and reduces the smoke density grade of the composite material.

4. A preparation method of a high-flame-retardant smoke-suppression PVC-U insulating electrical bushing specifically comprises the following steps:

s1: weighing the raw materials according to the formula;

s2: sequentially adding the raw materials in the S1 into a hot mixing blender mixer for high-speed mixing, and discharging into a cold mixing blender mixer for mixing when the material temperature reaches 110-120 ℃;

s3: discharging the materials into a hopper when the temperature of the materials in the cold mixing blender mixer is reduced to 50 ℃ or below;

s4: adding the mixed material obtained in the step S3 into a double-screw extruder, and extruding through plasticization;

s5: and (3) forming a die, carrying out vacuum sizing, cooling, drawing, cutting to a fixed length, and packaging to obtain the high-flame-retardant smoke-suppression PVC-U insulating electrical bushing.

Technical Field

The invention relates to the technical field of PVC-U insulating electrical sleeves, in particular to a high-flame-retardant smoke-suppressing PVC-U insulating electrical sleeve and a preparation method thereof.

Background

Polyvinyl chloride (PVC), which is a polymer obtained by polymerizing Vinyl Chloride Monomer (VCM) with an initiator such as peroxide and azo compound or by a radical polymerization mechanism under the action of light and heat, is a homopolymer of vinyl chloride. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively referred to as vinyl chloride resins.

Due to the existence of chlorine groups, PVC is easy to undergo autocatalytic dehydrochlorination reaction under the action of heating, shearing or high-energy rays (such as ultraviolet rays) and the like, so that a conjugated polyene chain is formed, and a series of chain reactions such as chain breaking, crosslinking and the like of a molecular chain cause PVC to degrade and discolor, the performance of a product is reduced, and the service life is influenced. In addition, the viscous flow temperature of PVC resin is 135 ℃, PVC can be obviously decomposed at about 145 ℃, and ultraviolet rays, external force, oxygen, HCI and active metal ions can greatly accelerate the decomposition of PVC, thereby causing serious influence on the performance of products. Therefore, various processing aids, such as heat stabilizers, lubricants and the like, are required to be added in the processing process of the PVC resin. The content of chlorine in PVC is higher than the normal value, the PVC is a self-extinguishing polymer, the oxygen index is higher than 40%, but the oxygen index is reduced due to the addition of a plasticizer and other additives in the processing process, and the product cannot meet the flame retardant requirement; meanwhile, PVC can release a large amount of black smoke and harmful gases (benzene, hydrogen chloride, etc.) during combustion.

Therefore, the development of the high-flame-retardant smoke-inhibiting PVC-U insulating electrical bushing has great significance and wide application prospect for inhibiting the generation of toxic gas in the combustion process and reducing the smoke amount.

Disclosure of Invention

The invention aims to provide a PVC-U insulating electrical bushing for inhibiting the generation of toxic gas in a combustion process and reducing smoke quantity.

In order to achieve the purpose, the invention provides a high-flame-retardance smoke-suppression PVC-U insulating electrical bushing which comprises the following raw materials in parts by weight: PVC SG-5: 100 parts of calcium-zinc stabilizer: 3-5 parts of microcrystalline wax: 1-3 parts of light calcium carbonate: 10-20 parts of organic montmorillonite (OMMT): 2-10 parts of hydrotalcite (LDHS): 2-10 parts of titanium dioxide: 0.1-1 part, CPE (chlorinated polyethylene): 2-5 parts, ACR (acrylate): 1-5 parts of fluorescent whitening agent KB: 0.01 part.

Specifically, the calcium zinc stabilizer can prevent or inhibit the degradation of the resin during the processing of the resin to remove HCl, and meanwhile, the calcium zinc stabilizer can maintain sufficient thermal stability and slow down the degradation caused by the thermal (light) action during the effective service life of the product, so that the service life is prolonged.

Specifically, the microcrystalline wax can prevent adhesion between a plastic melt and metal, improve the flow rate of the melt, reduce the displacement resistance of the material melt in processing, and promote plasticization.

In particular, the light calcium carbonate can play a role in increasing capacity and reducing cost, and can also play a role in improving the processing performance, the physical and mechanical properties and the chemical resistance of plastic products.

Specifically, the organic montmorillonite (OMMT) is Modified Montmorillonite (MMT), and can improve the flame retardant property, smoke suppression property, mechanical property and thermal stability of PVC.

Specifically, the hydrotalcite (LDHS) is a bimetallic hydroxide with a layered structure, has the advantages of two flame retardants of magnesium hydroxide and aluminum hydroxide, and is a flame retardant material which is non-toxic, smoke-free and flame-retardant and can improve the thermal stability of PVC.

Specifically, the OMMT and the LDHs have a synergistic effect, so that the flame retardant property of the composite material is improved. The OMMT can prevent flammable micromolecules generated by PVC molecular chain degradation from diffusing to the outside during combustion of the composite material, and can delay the migration of external oxygen to the inside so as to delay the progress of combustion and play a role in flame retardance. LDHs is heated to decompose water vapor to dilute carbon particles generated by PVC combustion, and the carbon particles react with the LDHs to generate CO₂、CO、H₂O, has the function of flame retardance, LDHs has alkalinity, small specific surface area and apparent alkalinity, and LDO (low dropout regulator) which is a combustion product shows stronger performanceThe LDO is alkaline, has higher specific surface area, is a porous alkaline substance, can absorb acid gas generated by PVC combustion, and the formation of the metal oxide LDO can change the thermal decomposition path of PVC, promote the high crosslinking of the PVC, promote the formation of carbon residue and increase the oxygen index.

Specifically, the OMMT and the LDHs have a synergistic effect, so that the smoke density grade of the composite material can be reduced. This is because OMMT has a high aspect ratio, and therefore has good barrier properties against O in air₂Enter the product, and the LDHs has the crystal water, hydroxyl and carbonate, is similar to brucite, and has alkaline sites between layers. The water dehydrated by heating among LDHs layers and the water generated by decomposing hydroxyl can dilute oxygen in the air and combustible gas generated by decomposing polymer, and the LDHs laminate contains alkaline sites which have an adsorption effect on acid gas and can effectively absorb acid mist generated by HCl.

Specifically, the titanium dioxide can make the product beautiful, further improve the commodity value, and also can improve the weather resistance and the optical performance of the product.

Specifically, the CPE can improve the toughness of the rigid polyvinyl chloride pipe.

Specifically, the ACR can improve the toughness and the impact resistance of the hard polyvinyl chloride pipe.

The invention also discloses a preparation method of the high-flame-retardant smoke-suppression PVC-U insulating electrical bushing, which comprises the following steps.

S1: weighing the raw materials according to the formula.

S2: and sequentially adding the raw materials in the S1 into a hot mixing blender mixer for high-speed mixing, and discharging into a cold mixing blender mixer for mixing when the material temperature reaches 110-120 ℃.

S3: when the temperature of the materials in the cold mixing blender is reduced to 50 ℃ or below, the materials are discharged into a hopper.

S4: and feeding the mixed material obtained in the step S3 into a double-screw extruder, and extruding by plasticizing.

S5: and (3) forming a die, carrying out vacuum sizing, cooling, drawing, cutting to a fixed length, and packaging to obtain the high-flame-retardant smoke-suppression PVC-U insulating electrical bushing.

By implementing the technical scheme, the PVC-U insulating electrical bushing with high flame retardance and smoke suppression and the preparation method thereof have the beneficial effects that: can effectively inhibit the generation of toxic gas in the combustion process of the product and reduce the smoke quantity.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

The first embodiment.

Weighing the following raw materials in parts by weight: PVC SG-5: 100 parts of calcium-zinc stabilizer: 3.5 parts, microcrystalline wax: 2 parts of light calcium carbonate: 16 parts of organic montmorillonite (OMMT): 8 parts, hydrotalcite (LDHS): 4 parts, titanium dioxide: 0.8 part, CPE (chlorinated polyethylene): 3.5 parts, ACR (acrylates): 2 parts, fluorescent whitening agent KB: 0.01 part.

The preparation method of the high-flame-retardant smoke-suppression PVC-U insulating electrical casing specifically comprises the following steps.

S1: weighing the raw materials according to the formula.

S2: and sequentially adding the raw materials in the S1 into a hot mixing blender mixer for high-speed mixing, and discharging into a cold mixing blender mixer for mixing when the material temperature reaches 110-120 ℃.

S3: when the temperature of the materials in the cold mixing blender is reduced to 50 ℃ or below, the materials are discharged into a hopper.

S4: and feeding the mixed material obtained in the step S3 into a double-screw extruder, and extruding by plasticizing.

S5: and (3) forming a die, carrying out vacuum sizing, cooling, drawing, cutting to a fixed length, and packaging to obtain the high-flame-retardant smoke-suppression PVC-U insulating electrical bushing.

Example two.

Weighing the following raw materials in parts by weight: PVC SG-5: 100 parts of calcium-zinc stabilizer: 4.5 parts, microcrystalline wax: 2.5 parts of light calcium carbonate: 16 parts of organic montmorillonite (OMMT): 5 parts of hydrotalcite (LDHS): 6 parts of titanium dioxide: 0.8 part, CPE (chlorinated polyethylene): 3.5 parts, ACR (acrylates): 2 parts, fluorescent whitening agent KB: 0.01 part.

The forming process is the same as the first embodiment, and detailed description is omitted here.

Example three.

Weighing the following raw materials in parts by weight: PVC SG-5: 100 parts of calcium-zinc stabilizer: 4 parts, microcrystalline wax: 2.2 parts of light calcium carbonate: 16 parts of organic montmorillonite (OMMT): 6 parts of hydrotalcite (LDHS): 5 parts, titanium dioxide: 0.5 part, CPE (chlorinated polyethylene): 3.5 parts, ACR (acrylates): 2 parts, fluorescent whitening agent KB: 0.01 part.

The forming process is the same as the first embodiment, and detailed description is omitted here.

Comparative example.

Weighing the following raw materials in parts by weight: PVC SG-5: 100 parts of calcium-zinc stabilizer: 3.5 parts, microcrystalline wax: 2.2 parts of light calcium carbonate: 16 parts, titanium dioxide: 0.5 part, CPE (chlorinated polyethylene): 3.5 parts, ACR (acrylates): 2 parts, fluorescent whitening agent KB: 0.01 part.

The forming process is the same as the first embodiment, and detailed description is omitted here.

The modified materials obtained in example one, example two and example three were prepared into plastic standard samples, and comparative examples and examples were set up to compare the experimental results of all examples and comparative examples in table 1.

TABLE 1

。

The test results in the above table 1 show that the PVC-U insulating electrical bushing of the present invention significantly improves the bending strength while ensuring the tensile strength and the normal temperature notch impact strength, and also has excellent flame retardancy and smoke suppression properties.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.