阅读说明：本技术 一种耐低温橡胶电缆涂料及其制备方法 (Low-temperature-resistant rubber cable coating and preparation method thereof ) 是由 林奕利 王海勇 于 2021-01-22 设计创作，主要内容包括：本发明提供一种耐低温橡胶电缆涂料及其制备方法；该耐低温橡胶电缆涂料由以下重量百分比的组分组成：四氟乙烯共聚物：30-40％,醇酯十二：10-20％,溶剂：40-60％,其中,四氟乙烯共聚物通过可逆加成-断裂链转移活性自由基聚合反应在聚四氟乙烯的分子链上引入2-((3-氨基-2-甲基-3-氧基丙酰基)氧基)甲基丙烯酸乙酯,从而对聚四氟乙烯分子链进行改性,2-((3-氨基-2-甲基-3-氧基丙酰基)氧基)甲基丙烯酸乙酯的引入降低的聚四氟乙烯的刚性、提高了聚四氟乙烯的表面粘性,使耐低温橡胶电缆涂料与橡胶电缆之间形成氢键结构,增强耐低温橡胶好的保电缆涂料与橡胶电缆之间的结合力,低温下对橡胶电缆起到良护作用,防止橡胶电缆在-25℃以下开裂。(The invention provides a low-temperature-resistant rubber cable coating and a preparation method thereof; the low-temperature-resistant rubber cable coating comprises the following components in percentage by weight: tetrafluoroethylene copolymer: 30-40%, alcohol ester twelve: 10-20%, solvent: 40-60 percent, wherein the tetrafluoroethylene copolymer introduces 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate on the molecular chain of the polytetrafluoroethylene through reversible addition-fragmentation chain transfer active free radical polymerization reaction, therefore, a polytetrafluoroethylene molecular chain is modified, the introduction of 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate reduces the rigidity of polytetrafluoroethylene, improves the surface viscosity of the polytetrafluoroethylene, forms a hydrogen bond structure between the low temperature resistant rubber cable coating and the rubber cable, enhances the binding force between the cable coating and the rubber cable with good low temperature resistance rubber, plays a good role in protecting the rubber cable at low temperature, and prevents the rubber cable from cracking below-25 ℃.)

1. The low-temperature-resistant rubber cable coating is characterized by comprising the following components in percentage by weight: tetrafluoroethylene copolymer: 30-40%, alcohol ester twelve: 10-20%, solvent: 40-60 percent; wherein the tetrafluoroethylene copolymer has a structure represented by formula (I):

2. the low temperature resistant rubber cable coating of claim 1, wherein the solvent is one of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide or toluene, tetrahydrofuran, acetone, butanone, and ethyl acetate.

3. The low temperature resistant rubber cable coating of claim 1, wherein the tetrafluoroethylene copolymer is prepared by a process comprising the steps of:

sequentially adding a solvent, a chain transfer agent and SOCl into a closed reaction kettle under the protection of nitrogen₂Acid binding agent, tetrafluoroethylene, 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate and initiator are continuously stirred, heated and heated, the reaction kettle is connected with constant-pressure nitrogen in the whole process to keep the kettle pressure unchanged, the temperature and the stirring speed unchanged, and the temperature is reduced after the reaction time is reached,Centrifuging, filtering, washing with ethanol, and drying to obtain tetrafluoroethylene copolymer.

4. The low temperature resistant rubber cable coating of claim 3, wherein: the solvent is any one of tetrahydrofuran, trichlorotrifluoroethane, ethyl acetate, toluene and dioxane.

5. The low temperature resistant rubber cable coating of claim 3, wherein: the chain transfer agent is at least one of 4-cyano-4- (thiobenzoyl) valeric acid, dithiophenylacetic acid, alpha-dithio-phenylmethyl p-phenylmethylene pyridinium chloride, S ' -bis (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate and xanthate.

6. The low temperature resistant rubber cable coating of claim 3, wherein: the acid-binding agent is any one of pyridine, triethylamine, N-diisopropylethylamine, 4-dimethylaminopyridine, triethanolamine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate and sodium carbonate.

7. The low temperature resistant rubber cable coating of claim 3, wherein: the initiator is any one of azodiisobutyronitrile, diacyl peroxide and persulfate.

8. The low temperature resistant rubber cable coating of claim 3, wherein: the reaction temperature is 70-100 ℃, the kettle pressure is 2-3MPa, and the reaction time is 8-12 h.

9. The low temperature resistant rubber cable coating of claim 1, wherein the low temperature resistant rubber cable coating is applied in a rubber cable.

10. The method for preparing the low temperature resistant rubber cable coating according to claim 1, comprising the following steps: stirring the tetrafluoroethylene copolymer and the solvent for 20 minutes in a stirrer under the condition of continuous stirring, adding the alcohol ester for twelve minutes under the stirring condition, and stirring for 100 minutes to prepare the low temperature resistant rubber cable coating.

Technical Field

The invention belongs to the field of high molecular polymers, and particularly relates to a low-temperature-resistant rubber cable coating and a preparation method thereof.

Background

Polytetrafluoroethylene (PTFE), commonly known as "plastic king", is a high molecular polymer made by polymerization of tetrafluoroethylene as monomer, there are a large amount of C-F bonds in the polytetrafluoroethylene molecular chain, the bond energy of C-F bond is high, and the van der Waals radius of the fluorine atom is greater than hydrogen atom, the van der Waals interaction among the atoms is greater, produce the stronger repulsive force, make PTFE molecule adopt the spiral conformation in crystalline state, add the appropriate atomic radius of fluorine atom, make each fluorine atom can be very close to with fluorine atom on the carbon atom that separates, such conformation makes fluorine atom can surround and form a protective layer of low surface energy around carbon-carbon backbone; due to the unique perfluorocarbon molecular structure, PTFE has excellent corrosion resistance, insulating property, high and low temperature resistance, self-lubricating property, surface non-stick property, weather resistance, lower permeability, non-combustibility and other properties.

However, polytetrafluoroethylene generally has the defects of easy deformation, non-adhesiveness and poor low-temperature resistance in the processing process; when the coating is applied to rubber cables as a coating, the low-temperature cracking of the rubber cables cannot be well prevented. Based on the low temperature resistant rubber cable coating, the invention prepares the low temperature resistant rubber cable coating.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention provides a low-temperature-resistant rubber cable coating which is prepared from the following components in percentage by weight: tetrafluoroethylene copolymer: 30-40%, alcohol ester twelve: 10-20%, solvent: 40-60 percent; the molecular chain of the tetrafluoroethylene copolymer is introduced with 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate to modify the molecular chain of the polytetrafluoroethylene, so that the low temperature resistance of the low temperature resistant rubber cable coating is greatly improved.

The invention aims to provide a low-temperature-resistant rubber cable coating.

The invention also aims to provide a preparation method of the low temperature resistant rubber cable coating.

The invention also aims to provide the application of the low-temperature resistant rubber cable coating in rubber cables.

The above purpose of the invention is realized by the following technical scheme:

the low-temperature-resistant rubber cable coating comprises the following components in percentage by weight: tetrafluoroethylene copolymer: 30-40%, alcohol ester twelve: 10-20%, solvent: 40-60 percent; wherein the tetrafluoroethylene copolymer has a structure represented by formula (I):

further, the solvent is one of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide or toluene, tetrahydrofuran, acetone, butanone and ethyl acetate.

Further, the preparation method of the tetrafluoroethylene copolymer comprises the following steps:

sequentially adding a solvent, a chain transfer agent and SOCl into a closed reaction kettle under the protection of nitrogen₂Acid binding agent, tetrafluoroethylene, 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate and initiator, continuously stirring, heating, connecting the reaction kettle with constant-pressure nitrogen in the whole process to keep the kettle pressure unchanged, keeping the temperature and stirring speed unchanged, cooling after reaching the reaction time, centrifuging, filtering, washing with ethanol, and drying to obtain the tetrafluoroethylene copolymer.

Further, the solvent is any one of tetrahydrofuran, trichlorotrifluoroethane, ethyl acetate, toluene and dioxane.

Further, the chain transfer agent is at least one of 4-cyano-4- (thiobenzoyl) valeric acid, dithiophenylacetic acid, alpha-dithio-phenylmethyl p-phenylmethylene pyridinium chloride, S ' -bis (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate and xanthate.

Further, the acid binding agent is any one of pyridine, triethylamine, N-diisopropylethylamine, 4-dimethylaminopyridine, triethanolamine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate and sodium carbonate.

Further, the initiator is any one of azobisisobutyronitrile, diacyl peroxide and persulfate.

Further, the reaction temperature is 70-100 ℃, the kettle pressure is 2-3MPa, and the reaction time is 8-12 h.

Further, the low-temperature-resistant rubber cable coating is applied to rubber cables.

Further, the preparation method of the low temperature resistant rubber cable coating comprises the following steps: stirring the tetrafluoroethylene copolymer and the solvent for 20 minutes in a stirrer under the condition of continuous stirring, adding the alcohol ester for twelve minutes under the stirring condition, and stirring for 100 minutes to prepare the low temperature resistant rubber cable coating.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the invention, 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate is introduced to a molecular chain of polytetrafluoroethylene through reversible addition-fragmentation chain transfer active radical polymerization reaction, so that the molecular chain of the polytetrafluoroethylene is modified, the rigidity of the polytetrafluoroethylene is reduced and the surface viscosity of the polytetrafluoroethylene is improved due to the introduction of the 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate, a hydrogen bond structure is formed between the polytetrafluoroethylene material and a rubber cable, the bonding force between the polytetrafluoroethylene material and the rubber cable is enhanced, a good protection effect is achieved on the rubber cable at low temperature, and the rubber cable is prevented from cracking below-25 ℃.

(2) In addition, the difficult problem of insolubility of tetrafluoroethylene homopolymer is greatly improved by introducing 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate, the application range of the tetrafluoroethylene polymer is widened, the characteristic of difficult processing of the traditional tetrafluoroethylene polymer is broken, and the low-temperature resistant rubber cable coating is prepared.

Drawings

FIG. 1 is a schematic diagram of the synthesis of a tetrafluoroethylene copolymer.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

50mL of dioxane, 0.5mmol of 4-cyano-4- (thiobenzoyl) valeric acid and 1mmol of SOCl are sequentially added into a closed reaction kettle under the protection of nitrogen₂0.12mL of pyridine, 20mmol of tetrafluoroethylene, 20mmol of 2- ((3-amino-2-methyl-3-oxypropionyl) oxy) ethyl methacrylate and 0.02mmol of azobisisobutyronitrile, continuously stirring, heating to 70 ℃, connecting the reaction kettle with constant-pressure nitrogen in the whole process to keep the kettle pressure at 2MPa, keeping the temperature and the stirring speed at constant, reacting for 8 hours, cooling, centrifuging, filtering, washing with ethanol, and drying to obtain the tetrafluoroethylene copolymer.

Example 2

Continuously stirring the tetrafluoroethylene copolymer with the weight percentage of 30 percent and the solvent with the weight percentage of 55 percent in a stirrer for 20 minutes, then adding the alcohol ester with the weight percentage of 15 percent under the stirring condition and stirring for 100 minutes to prepare the low temperature resistant rubber cable coating.

Example 3

Continuously stirring the tetrafluoroethylene copolymer with the weight percentage of 35 percent and the solvent with the weight percentage of 50 percent in a stirrer for 20 minutes, then adding the alcohol ester with the weight percentage of 15 percent under the stirring condition and stirring for 100 minutes to prepare the low temperature resistant rubber cable coating.

Example 4

Continuously stirring the tetrafluoroethylene copolymer with the weight percentage of 40 percent and the solvent with the weight percentage of 45 percent in a stirrer for 20 minutes, then adding the alcohol ester with the weight percentage of 15 percent under the stirring condition and stirring for 100 minutes to prepare the low temperature resistant rubber cable coating.

Example 5

The low-temperature-resistant rubber cable coating prepared in the example 2 is placed into a spray gun hopper after passing through a 150-mesh screen, the coating is atomized, a spray gun and the surface of a sample are kept vertical, the spray gun moves in one direction and moves in parallel, the moving speed is 9m/min, the spraying distance between the spray gun and the sample is 260mm, the spraying is carried out for 4 times step by step in sequence, the sprayed sample is placed into a constant-temperature drying box, the temperature is kept for 12min after the sample is heated to 60-80 ℃, the temperature is raised to 140 ℃, and the temperature is kept for 13 min; taking out, putting into a 375 ℃ box-type resistance furnace, plasticizing for 20min, carrying out secondary spraying and plasticizing on the sample according to the process, wherein the plasticizing time is 25min, immersing the sample plasticized for the second time into cold water for treatment, drying moisture, and carrying out tertiary spraying and plasticizing according to the process, wherein the plasticizing time is 30 min; obtaining the low temperature resistant rubber cable coating.

Example 6

The low-temperature-resistant rubber cable coating prepared in the embodiment 3 is placed into a spray gun hopper after passing through a 150-mesh screen, the coating is atomized, a spray gun and the surface of a sample are kept vertical, the spray gun moves in one direction and moves in parallel, the moving speed is 9m/min, the spraying distance between the spray gun and the sample is 260mm, the spraying is carried out for 4 times step by step in sequence, the sprayed sample is placed into a constant-temperature drying box, the temperature is kept for 12min after the sample is heated to 60-80 ℃, the temperature is raised to 140 ℃, and the temperature is kept for 13 min; taking out, putting into a 375 ℃ box-type resistance furnace, plasticizing for 20min, carrying out secondary spraying and plasticizing on the sample according to the process, wherein the plasticizing time is 25min, immersing the sample plasticized for the second time into cold water for treatment, drying moisture, and carrying out tertiary spraying and plasticizing according to the process, wherein the plasticizing time is 30 min; obtaining the low temperature resistant rubber cable coating.

Example 7

The low-temperature-resistant rubber cable coating prepared in the embodiment 4 is placed into a spray gun hopper after passing through a 150-mesh screen, the coating is atomized, a spray gun and the surface of a sample are kept vertical, the spray gun moves in one direction and moves in parallel, the moving speed is 9m/min, the spraying distance between the spray gun and the sample is 260mm, the spraying is carried out for 4 times step by step in sequence, the sprayed sample is placed into a constant-temperature drying box, the temperature is kept for 12min after being heated to 60-80 ℃, the temperature is raised to 140 ℃, and the temperature is kept for 13 min; taking out, putting into a 375 ℃ box-type resistance furnace, plasticizing for 20min, carrying out secondary spraying and plasticizing on the sample according to the process, wherein the plasticizing time is 25min, immersing the sample plasticized for the second time into cold water for treatment, drying moisture, and carrying out tertiary spraying and plasticizing according to the process, wherein the plasticizing time is 30 min; obtaining the low temperature resistant rubber cable coating.

Comparative example 1

Continuously stirring the mixture for 20 minutes in a stirrer with commercial polytetrafluoroethylene accounting for 40 percent by weight and solvent accounting for 45 percent by weight, then adding alcohol ester accounting for 15 percent by weight under the stirring condition, and stirring for 100 minutes to obtain polytetrafluoroethylene coating; after passing through a 150-mesh screen, loading the sample into a spray gun hopper, atomizing the coating, keeping the surfaces of a spray gun and a sample vertical, moving the spray gun in one direction and moving the spray gun in parallel, wherein the moving speed is 9m/min, the spraying distance between the spray gun and the sample is 260mm, gradually spraying for 4 times in sequence, putting the sprayed sample into a constant-temperature drying box, heating to 60-80 ℃, keeping the temperature for 12min, then heating to 140 ℃, and keeping the temperature for 13 min; taking out, putting into a 375 ℃ box-type resistance furnace, plasticizing for 20min, carrying out secondary spraying and plasticizing on the sample according to the process, wherein the plasticizing time is 25min, immersing the sample plasticized for the second time into cold water for treatment, drying moisture, and carrying out tertiary spraying and plasticizing according to the process, wherein the plasticizing time is 30 min; obtaining the polytetrafluoroethylene coating.

Table 1 results of the performance tests of the coatings prepared in examples 5 to 7 and comparative example 1.

As can be seen from Table 1, the thermal decomposition temperatures of the low temperature resistant rubber cable coatings prepared in examples 5 to 7 are not much different from the thermal decomposition temperature of the polytetrafluoroethylene coating prepared in comparative example 1, but the low temperature resistant rubber cable coatings prepared in examples 5 to 7 have higher tensile strength and are more wear-resistant, and the low temperature resistant rubber cable coatings prepared in the invention have better low temperature resistance, low deformation rate and more stable size in the using process.

Table 2 peel strength of the coatings prepared in examples 5-7 and comparative example 1.

A level shows very easy peeling, and the peeling force is less than 1N; b level represents easier stripping, and the stripping force is more than 1N and less than 2N; grade C indicates that it is more difficult to peel, with peel forces greater than 2N.

From table 2, it can be seen that the low temperature resistant rubber cable coating of the present invention has strong adhesion to rubber cables.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.