CN113621185A

CN113621185A - Halogen-free rubber-plastic heat-insulating material and preparation method thereof

Info

Publication number: CN113621185A
Application number: CN202111004248.1A
Authority: CN
Inventors: 高贺昌; 高贺勇; 何兵; 吴华明; 孙莹洁; 郭超
Original assignee: Huamei Energy Saving Technology Jiangxi Co ltd; Huamei Energy Saving Technology Group Co ltd
Current assignee: Huamei Energy Saving Technology Jiangxi Co ltd; Huamei Energy Saving Technology Group Co ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2021-11-09
Anticipated expiration: 2041-08-30
Also published as: CN113621185B

Abstract

The invention provides a halogen-free rubber-plastic heat-insulating material and a preparation method thereof, belonging to the field of high polymer rubber-plastic foaming. The invention adopts nitrile rubber and ethylene-butyl acrylate copolymer as framework materials, and adds foaming agent, flame retardant, plasticizer, reinforcing agent, stabilizer, accelerator, activator, anti-aging agent, lubricant, vulcanizing agent, anti-scorching agent and other raw materials, and prepares the halogen-free rubber-plastic heat-insulating material by vulcanization foaming. The halogen-free rubber-plastic heat-insulating material prepared by the invention has the advantages of no halogen, no metal corrosion, small smoke yield in the combustion process, low heat conduction, high flame retardance, good elasticity and the like.

Description

Halogen-free rubber-plastic heat-insulating material and preparation method thereof

Technical Field

The invention relates to the field of high polymer rubber and plastic foaming, in particular to a halogen-free rubber and plastic heat-insulating material and a preparation method thereof.

Background

Along with the national requirements for green sustainable development, the building has higher and higher requirements for energy conservation, and the use of the heat-insulating material can effectively reduce energy consumption, realize energy conservation and emission reduction, and meet the requirements of green buildings. The traditional rubber-plastic heat-insulating material is mostly obtained by vulcanizing and foaming nitrile rubber, polyvinyl chloride, chlorinated paraffin in combination with auxiliary agents such as foaming agent, vulcanizing agent, flame retardant and the like. The foaming material contains partial halogen, and when the foaming material is used in a humid environment, the halogen can corrode a metal pipeline, so that the service life of the metal pipeline is shortened; meanwhile, when a fire disaster occurs, harmful smoke is generated due to the combustion of the foaming material, and the health of people is harmed.

In addition, the rubber and plastic produced at present is a rubber and plastic heat-insulating foaming material obtained by blending and foaming nitrile rubber, polyvinyl chloride, chlorinated polyethylene and chlorinated paraffin, and because the rubber and plastic heat-insulating foaming material contains chloride ions, the rubber and plastic heat-insulating foaming material has a corrosion effect on a copper pipe in the using process and can release a large amount of smoke during combustion. Therefore, it is highly desirable to obtain a foam material which does not generate halogen while maintaining the heat insulating properties of the material.

The patent with the application number of CN201310038430.8 discloses a high-flame-retardancy flexible foam rubber-plastic heat-insulation product and a preparation method thereof, the main material used by the product is polyvinyl chloride, and the flame retardants are mainly four types, namely zinc borate, antimony trioxide, aluminum hydroxide and chlorinated polyethylene, so that the technical problem that the oxygen index and the smoke density are mutually contradictory in the process manufacturing is effectively solved, but the used raw materials contain a certain amount of chloride ions, and in the using process, the chloride ions can corrode metal and can release harmful smoke when burning.

The patent with the application number of CN 103819839B discloses a halogen-free rubber-plastic product and a preparation method thereof, wherein the formula of the foaming material uses a raw material of polyvinyl chloride resin, chlorine is still introduced in the foaming material, the chlorine is not completely eradicated, the phenomenon that chlorine ions corrode metals still exists in the using process, and harmful smoke is released during combustion.

Patent application No. CN201410017108.1 discloses a method for preparing halogen-free rubber-plastic foamed heat-insulating material, wherein the raw materials used in the foamed material are halogen-free, but no cross-linking agent is added in the preparation process for modifying rubber. The rubber cannot form a net structure without adding a cross-linking agent, so that not only are foam pores formed in the foaming process unstable and easy to break, but also the thermal insulation performance of the product is greatly influenced, and meanwhile, the compression rebound and tear resistance of the product are influenced. In addition, the formulation of this application does not contain an accelerator, which reduces the production rate.

Disclosure of Invention

In view of the above, the invention provides a halogen-free rubber-plastic heat-insulating material and a preparation method thereof, and the halogen-free rubber-plastic heat-insulating material provided by the invention has the advantages of good heat-insulating property, no corrosion to metal pipelines, high oxygen index, no generation of a large amount of harmful gas during combustion, stable production efficiency and the like, and simultaneously prolongs the service life of products and reduces the use cost of the products.

The invention provides a halogen-free rubber-plastic heat-insulating material which comprises the following components in percentage by weight:

15-18% of nitrile rubber;

2.5 to 5 percent of ethylene-butyl acrylate copolymer;

13-15% of azodicarbonamide;

40-42% of aluminum hydroxide;

7.5 to 9.5 percent of triaryl phosphate;

3-4% of carbon black;

0.5 to 1.5 percent of paraffin;

0.1 to 0.3 percent of stearic acid;

0.25 to 0.4 percent of calcium stearate;

0.8 to 1.2 percent of polyethylene glycol;

0.25 to 0.35 percent of 2, 6-di-tert-butyl-p-cresol;

2 to 2.5 percent of antimony trioxide;

1-1.5% of zinc borate;

EBS 0.75-1.25％；

0.65-0.8% of 2-mercaptobenzimidazole;

0.15 to 0.25 percent of zinc oxide;

0.2 to 0.4 percent of sulfur;

0.25-0.35% of zinc benzene sulfinate;

0.5 to 2.5 percent of accelerant PZ;

0.2 to 0.75 percent of accelerator DPTT;

1.5-2% of N-cyclohexyl thiophthalimide.

Preferably, the framework material is nitrile rubber and an ethylene-butyl acrylate copolymer, the ethylene-butyl acrylate copolymer has high polarity, so that the ethylene-butyl acrylate copolymer has good compatibility with the nitrile rubber, and the blending of the ethylene-butyl acrylate copolymer and the nitrile rubber achieves a toughening effect with low cost.

Preferably, the rubber lubricant is EBS, which increases the mold filling speed of the rubber material, improves the quality of the foamed product and increases the flatness of the outer skin.

Preferably, the aluminum hydroxide, the antimony trioxide, the zinc borate and the triaryl phosphate are used as flame retardants, and the phosphorus flame retardants, the antimony trioxide and the aluminum hydroxide act synergistically to promote the generation of a carbon layer in the combustion process and inhibit the generation of organic volatile cracking products, so that the flame retardance of the material is greatly improved.

Preferably, the triaryl phosphate is a plasticizer, and the triaryl phosphate replaces the traditional flame-retardant plasticizer chlorinated paraffin, so that the addition of chloride ions is avoided, the viscosity of a melt can be reduced, the flexibility of the copolymer is increased, the rubber mixing time is shortened, the yield is improved, the rubber mixing cost of a product is reduced, and the flexibility of a rubber material is improved.

The invention also provides a preparation method of the halogen-free rubber-plastic heat-insulating material, which comprises the following steps:

(1) mixing: weighing raw materials in proportion, putting the nitrile rubber into an internal mixer, and banburying for 1-2min to obtain raw rubber; dividing aluminum hydroxide and triaryl phosphate into two parts, wherein the mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 4:1, the mass ratio of the first part of triaryl phosphate to the second part of triaryl phosphate is 2:1, putting the first part of aluminum hydroxide, the first part of triaryl phosphate, ethylene-butyl acrylate copolymer, azodicarbonamide, carbon black, paraffin, stearic acid, calcium stearate, polyethylene glycol, 2, 6-di-tert-butyl-p-cresol, 2-mercaptobenzimidazole, antimony trioxide, zinc borate, EBS into an internal mixer, mixing for 3-4min, then adding a second part of aluminum hydroxide and a second part of triaryl phosphate into the internal mixer to continuously mix for 6-8min, heating to 160-178 ℃, discharging the rubber material, placing the rubber material on an open mill, mixing for 3-4.5min, and slicing to obtain a material No. 1;

(2) and (3) vulcanization foaming: and (2) putting the material 1 obtained in the step (1), zinc oxide, an accelerator PZ, an accelerator DPTT, zinc benzene sulfinate, sulfur and N-cyclohexyl thiophthalimide into an internal mixer, mixing for 4-6min, putting the mixture into an open mill, mixing for 3-4.5min, cutting the mixture into rubber strips to obtain a material 2, and extruding and molding the material 2 through an extruder to obtain the molding compound. And then continuously feeding the molding compound into a foaming furnace for vulcanization foaming, and cooling to obtain the halogen-free rubber-plastic heat-insulating material.

Preferably, the temperature of the screw of the extruder in the step (2) is 25-40 ℃, the temperature of the feeding section is 40-50 ℃, the temperature of the plasticizing section is 40-55 ℃, and the temperature of the machine head section is 40-45 ℃.

Preferably, in the step (2), the vulcanization foaming is to place the molding compound in a foaming furnace, and perform foaming treatment in 7 foaming zones in sequence, wherein the transmission speed of one zone is 1.2-1.6m/min, the transmission speed of the second zone is 1.25-2.3m/min, the transmission speed of the third zone is 1.68-2.95m/min, the transmission speed of the fourth zone is 2.45-3.85m/min, the transmission speed of the fifth zone is 3.25-4.95m/min, the transmission speed of the sixth zone is 4.68-6.12m/min, and the transmission speed of the seventh zone is 5.7-8.96 m/min.

Preferably, the foaming furnace is divided into 7 zones according to the temperature, and the temperature of the 7 zones is respectively as follows: the first zone is 120-.

Compared with the prior art, the invention provides a halogen-free rubber-plastic heat-insulating material, which is prepared by taking nitrile rubber and ethylene-butyl acrylate copolymer as framework materials, aluminum hydroxide as flame-retardant filler, antimony trioxide and zinc borate as flame retardants, triaryl phosphate as flame-retardant plasticizers, paraffin, stearic acid, polyethylene glycol and EBS as rubber lubricants, sulfur as vulcanizing agents, zinc benzenesulfinate and zinc oxide as activators, accelerator PZ and accelerator DPTT as vulcanization accelerators, and combining raw materials such as an anti-aging agent and an anti-scorching agent through vulcanization foaming. The halogen-free rubber-plastic heat-insulating material provided by the invention has the characteristics of no halogen, no metal corrosion, and small smoke yield in the combustion process, and also has the advantages of low heat conduction, high flame retardance, high strength, good elasticity and the like.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The raw material compositions of examples 1 to 5 are shown in Table 1.

TABLE 1

The preparation method of the halogen-free rubber-plastic thermal insulation material in the above embodiment 1-5 comprises the following steps:

(1) mixing: weighing raw materials in proportion, putting the nitrile rubber into an internal mixer, and banburying for 1min to obtain raw rubber; dividing aluminum hydroxide and triaryl phosphate into two parts, wherein the mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 4:1, the mass ratio of the first part of triaryl phosphate to the second part of triaryl phosphate is 2:1, putting the first part of aluminum hydroxide, the first part of triaryl phosphate, an ethylene-butyl acrylate copolymer, azodicarbonamide, carbon black, paraffin, stearic acid, calcium stearate, polyethylene glycol, 2, 6-di-tert-butyl-p-cresol, 2-mercaptobenzimidazole, antimony trioxide, zinc borate and EBS into internal mixing, mixing for 3.5min, then adding the second part of aluminum hydroxide and the second part of triaryl phosphate, continuously mixing for 7min, discharging the rubber material after the temperature is raised to 175 ℃, placing the rubber material on an open mill, mixing for 4min, and slicing to obtain material No. 1;

(2) and (3) vulcanization foaming: and (2) putting the material 1 obtained in the step (1), zinc oxide, an accelerator PZ, an accelerator DPTT, zinc benzene sulfinate, sulfur and N-cyclohexyl thiophthalimide into an internal mixer for mixing for 6min, putting the mixture into an open mill for mixing for 4min, cutting the mixture into rubber strips to obtain a material 2, extruding and molding the material 2 by an extruder, wherein the temperature of a screw of the extruder is 35 ℃, the temperature of a feeding section is 45 ℃, the temperature of a plasticizing section is 45 ℃, the temperature of a machine head section is 40 ℃ to obtain molding rubber, then carrying out foaming treatment on the molding rubber, and cooling to obtain the halogen-free rubber and plastic heat insulation material.

The performance of the halogen-free rubber-plastic heat-insulating materials of examples 1-5 of the present invention was tested, and the test results are shown in Table 2.

TABLE 2

Note: the test method of the corrosivity of the copper pipe comprises the following steps: the copper pipe is wrapped by rubber and plastic, the two ends of the copper pipe are not tightly sealed, the copper pipe is placed in an environment with the dry bulb temperature of 60 ℃ and the humidity of 95 percent, the copper pipe is free from corrosion phenomenon in 240 hours, the copper pipe is free from the conditions of unevenness, permeation and the like which influence the performance of the copper pipe, and the like after the experiment, and the copper pipe is free from serious oxidation and blackening phenomenon after the experiment.

Table 1 shows that the indexes of the examples 1-5 are higher than the national standard, the heat conductivity coefficient is improved along with the increase of the apparent density, and the corrosion of the copper pipe has no phenomena of oxidation, blackening and the like.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The halogen-free rubber-plastic heat-insulating material is characterized by comprising the following components in percentage by weight: 15 to 18 percent of nitrile rubber, 2.5 to 5 percent of ethylene-butyl acrylate copolymer, 13 to 15 percent of azodicarbonamide, 40 to 42 percent of aluminum hydroxide, 7.5 to 9.5 percent of triaryl phosphate, 3 to 4 percent of carbon black, 0.5 to 1.5 percent of paraffin, 0.1 to 0.3 percent of stearic acid, 0.25 to 0.4 percent of calcium stearate, 0.8 to 1.2 percent of polyethylene glycol, 0.25 to 0.35 percent of 2, 6-di-tert-butyl-p-cresol, 2 to 2.5 percent of antimonous oxide, 1 to 1.5 percent of zinc borate, 0.75 to 1.25 percent of EBS, 0.65 to 0.8 percent of 2-mercaptobenzimidazole, 0.15 to 0.25 percent of zinc oxide, 0.2 to 0.4 percent of sulfur, 0.25 to 0.35 percent of zinc benzene sulfinate, 0.5 to 2.5 percent of accelerant PZ, 0.2 to 0.75 percent of accelerant DPTT and 1.5 to 2 percent of N-cyclohexyl thiophthalimide.

2. The preparation method of the halogen-free rubber-plastic heat-insulating material according to claim 1, which comprises the following steps:

3. The method for preparing halogen-free rubber-plastic heat-insulating material according to claim 2, wherein the temperature of the screw of the extruder in step (2) is 25-40 ℃, the temperature of the feeding section is 40-50 ℃, the temperature of the plasticizing section is 40-55 ℃, and the temperature of the head section is 40-45 ℃.

4. The preparation method of the halogen-free rubber-plastic thermal insulation material according to claim 2, wherein in the step (2), the vulcanization foaming is performed by placing the molding compound in a foaming furnace and sequentially passing through 7 foaming zones for foaming treatment, wherein the transmission speed of one zone is 1.2-1.6m/min, the transmission speed of the second zone is 1.25-2.3m/min, the transmission speed of the third zone is 1.68-2.95m/min, the transmission speed of the fourth zone is 2.45-3.85m/min, the transmission speed of the fifth zone is 3.25-4.95m/min, the transmission speed of the sixth zone is 4.68-6.12m/min, and the transmission speed of the seventh zone is 5.7-8.96 m/min.

5. The preparation method of the halogen-free rubber-plastic heat-insulating material according to claim 4, wherein the foaming furnace is divided into 7 zones according to the temperature, and the temperature of the 7 zones is respectively as follows: the first zone is 120-.