Composite rubber and plastic thermal insulation material and preparation method thereof
By introducing carbon fiber cloth and self-made functional additives into traditional rubber and plastic materials, the problems of insufficient flame retardancy and oxidation resistance are solved, forming a composite rubber and plastic insulation material suitable for applications in high temperature environments.
Patent Information
- Application Number
- CN202510946101.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-09-12
AI Technical Summary
Traditional insulation materials have problems such as poor flame retardancy, easy aging, and insufficient mechanical strength, making it difficult to meet application requirements in high-temperature environments.
Carbon fiber cloth is used as a carrier and compounded with homemade functional additives containing Si, P, and S flame retardant elements to enhance the flame retardancy and antioxidant properties of the material, and it is combined with rubber and plastic materials through adhesives to form a composite rubber and plastic insulation material.
It significantly improves the flame retardancy and oxidation resistance of the material, inhibits thermal deformation, avoids cracking or delamination, is suitable for environments with large temperature differences, and extends service life.
Smart Images
Figure SMS_1 
Figure SMS_2 
Figure SMS_3
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of thermal insulation materials, and in particular to a composite rubber-plastic thermal insulation material and a preparation method thereof. Background Art
[0002] The use of thermal insulation materials is crucial in numerous fields, including construction, pipeline transportation, and industrial equipment. Their performance directly impacts energy loss, equipment stability, and service life. Traditional insulation materials, such as polystyrene foam, polyurethane foam, rock wool, and glass wool, while effective at providing insulation, suffer from numerous significant drawbacks. For example, polystyrene and polyurethane foams have poor fire resistance, are flammable, and release toxic gases when burned, posing a significant safety hazard. While rock wool offers good fire resistance, it has a rough texture and can easily irritate the skin and respiratory tract of construction workers during installation, causing discomfort such as itching and coughing. Furthermore, its high water absorption significantly reduces its insulation performance in humid environments, even rendering it ineffective. Glass wool also suffers from fiber shedding, which is not only harmful to human health, but also has poor aging resistance and is prone to powdering after long-term use, leading to a decline in insulation performance and requiring frequent replacement, increasing maintenance costs. Furthermore, traditional insulation materials have low mechanical strength and are easily damaged, requiring additional protective measures during construction, adding to project costs and complexity.
[0003] Due to their excellent flexibility, low thermal conductivity, and good waterproof properties, rubber-plastic insulation materials have been widely used in recent years as a highly efficient and energy-saving building material in the construction, chemical, electric power, and metallurgical industries. They are gradually becoming an ideal alternative to traditional insulation materials. However, conventional rubber-plastic materials still have some shortcomings, such as susceptibility to aging in high-temperature environments and, as organic polymers, their flammability and poor flame retardancy.
[0004] In this context, there is an urgent need to develop a composite rubber-plastic insulation material with both anti-aging and flame retardant properties and a preparation method thereof to meet higher demands in the field of insulation material technology. Summary of the Invention
[0005] The present invention provides a composite rubber-plastic thermal insulation material and a preparation method thereof, which solves the problems of poor aging resistance and flame retardancy of the rubber-plastic thermal insulation material in the related art.
[0006] The technical solutions of the present invention are as follows: The present invention provides a composite rubber-plastic thermal insulation material, comprising a main rubber-plastic material and a carrier carbon fiber cloth, the two being bonded together by an adhesive; The main rubber-plastic material comprises the following raw materials in parts by weight: 42-56 parts of nitrile rubber, 21-29 parts of polyvinyl chloride, 10-20 parts of EPDM rubber, 3-9 parts of functional additives, 4-8 parts of foaming agent, 1-2 parts of vulcanizing agent, 5-10 parts of plasticizer and 2-4 parts of lubricant.
[0007] As a further technical solution, the adhesive is one of a polyurethane adhesive, an epoxy resin adhesive and an acrylate adhesive.
[0008] As a further technical solution, the thickness of the carbon fiber cloth is 0.2-0.5 mm.
[0009] As a further technical solution, the foaming agent is one of azodicarbonamide and dinitrosopentamethylenetetramine.
[0010] As a further technical solution, the vulcanizing agent is one of dicumyl peroxide and sulfur.
[0011] As a further technical solution, the plasticizer is one of dibutyl phthalate and tributyl citrate.
[0012] As a further technical solution, the lubricant is one of polyethylene wax, zinc stearate and epoxidized soybean oil.
[0013] The present invention uses carbon fiber cloth as a carrier. Carbon fiber cloth is a reinforcing material woven from high-strength carbon fiber yarns. It can not only enhance the strength of the thermal insulation material, but also the thermal expansion coefficient of carbon fiber is close to zero, while the thermal expansion coefficient of rubber and plastic materials is relatively high. After the two are compounded, they can effectively inhibit thermal deformation and avoid cracking and delamination caused by shrinkage / expansion of the material in high or low temperature environments. It is suitable for scenes with large temperature differences.
[0014] As a further technical solution, the functional additive is prepared by the following steps: B1. Add trichlorothiophosphorus and pentaerythritol to a three-necked flask equipped with a thermometer, a magnetic stirrer, and a reflux condenser. After magnetic stirring for 10-20 minutes, introduce nitrogen into the apparatus and reflux in an oil bath at 140-150°C for 6-8 hours until no more hydrogen chloride gas is released and the reaction is complete. Extract with boiling water, remove the sticky material at the bottom of the flask by decantation, concentrate to remove some water, cool and crystallize, filter with suction, and dry to obtain reaction product A. In step B1, a solvent-free method is used, and pentaerythritol and phosphorus trichloride undergo a nucleophilic substitution reaction, and pentaerythritol is slightly excessive to reduce the occurrence of side reactions. The reaction formula is as follows:
[0015] B2. Add reaction product A and 3-aminopropyltrimethoxysilane to a three-necked flask equipped with a thermometer, a magnetic stirrer, and a reflux condenser. After magnetic stirring for 10-20 minutes, introduce nitrogen to remove air from the apparatus. Then, control the reaction temperature at 130-140° C. and carry out fractional distillation reaction for 3-4 hours. Continue to increase the temperature until the temperature reaches 150-160° C. and carry out fractional distillation reaction for 7-8 hours. After the reaction is completed, allow to cool, then add anhydrous ethanol, stir and disperse, and then filter and dry to obtain reaction product B. In step B2, a solvent-free method is used to react the reaction product A with 3-aminopropyltrimethoxysilane, and the molar ratio of the two is controlled to be close to 3:1 to obtain the reaction product B; the reaction formula is as follows:
[0016] B3. In a three-necked flask equipped with a thermometer, a magnetic stirrer, and a reflux condenser, first mix 3,5-di-tert-butyl-4-hydroxybenzoic acid and toluene, place in a water bath at 50-55°C, and magnetically stir until the solid is completely dissolved. Then, add the reaction product B and dicyclohexylcarbodiimide (catalyst) in sequence. Stir and react at this temperature for 6-8 hours. After the reaction is complete, cool naturally, filter, rotary evaporate, and purify by column chromatography to obtain a functional additive. In step B3, under the action of dicyclohexylcarbodiimide, 3,5-di-tert-butyl-4-hydroxybenzoic acid and the reaction product B undergo an amidation reaction; the specific reaction process is as follows:
[0017] The functional additive prepared by the present invention contains three flame retardant elements, namely Si, P and S, in its molecule. The compound containing Si-O bond will rearrange at high temperature to form Si-O-Si cross-linked network, and catalyze the dehydration and carbonization of the polymer matrix to form a dense, high-temperature resistant silicon-carbon composite carbon layer. In addition, the phosphorus-containing compound will decompose under heat to form active substances such as phosphoric acid and metaphosphoric acid, which will capture free radicals in the combustion reaction in the gas phase and inhibit the chain reaction; the sulfur-containing free radicals generated by the decomposition of the sulfur-containing compound can also react with the combustion free radicals, and the combination of the two It can terminate free radical reactions more efficiently and extinguish flames quickly. P and S work together to generate a phosphoric acid-sulfate composite carbon layer, which is more resistant to high-temperature oxidation than a pure phosphorus carbon layer. The three flame retardant elements work synergistically to greatly enhance the flame retardancy of the material. In addition, a hindered phenol antioxidant group is connected to one end of the functional additive, which can capture free radicals generated by molecular chain breakage caused by factors such as high temperature, oxygen, and light during the processing or use of rubber and plastic materials, thereby improving the antioxidant properties of the matrix and improving the homogeneity of the matrix compared to adding hindered phenol antioxidants alone.
[0018] As a further technical solution, in step B1, the ratio of pentaerythritol to phosphorus trichloride is 17.1 g:14.1 g.
[0019] As a further technical solution, in step B2, the ratio of the amount of reaction product A and 3-aminopropyltrimethoxysilane used is 61.2 g:17.9 g.
[0020] As a further technical solution, in step B3, the ratio of 3,5-di-tert-butyl-4-hydroxybenzoic acid, toluene, reaction product B, and dicyclohexylcarbodiimide is 24.9 g:150 mL:67.3 g:20.6 g.
[0021] The present invention also proposes a method for preparing a composite rubber-plastic thermal insulation material, comprising the following steps: A1. Add nitrile rubber, polyvinyl chloride and EPDM rubber to an internal mixer, and plasticize them at a temperature of 80-100°C and a speed of 40-60 r / min for 10-15 min. Then, add functional additives, plasticizers, lubricants, foaming agents and vulcanizing agents in sequence, and continue mixing at this temperature for 5-10 min to obtain a rubber mix; A2. The rubber mix obtained in step A1 is sheeted in an open mill, and then added to a foaming furnace for free foaming. After cooling, the material is discharged to obtain the main rubber-plastic material; A3. Pour the adhesive into the trough of the coating machine and evenly apply the adhesive to one side of the carbon fiber cloth and one side of the main rubber-plastic material obtained in step A2 by roller coating. Then, place the coated surfaces facing each other and compound them using a compounding machine to obtain a composite rubber-plastic thermal insulation material.
[0022] The working principle and beneficial effects of the present invention are: 1. The present invention makes its own functional additives and uses them as raw materials. The functional additives contain three flame retardant elements, Si, P, and S, which greatly improve the flame retardancy of the material; 2. The homemade functional additives contain hindered phenol groups, which can improve the antioxidant properties of the material and extend the service life of the material; 3. Using carbon fiber cloth as a carrier not only enhances the mechanical strength of the material, but also effectively inhibits the thermal deformation of rubber and plastic materials in an environment with large temperature differences, avoiding cracking or delamination; In summary, the present invention solves the problems of poor flame retardancy, easy aging, and insufficient mechanical strength of traditional thermal insulation materials through functional additive design and carbon fiber composite technology. It has broad application prospects and market competitiveness, and has important application value in the field of thermal insulation material technology. DETAILED DESCRIPTION
[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0024] Example 1 Preparation of functional additives: B1. In a three-necked flask equipped with a thermometer, a magnetic stirrer, and a reflux condenser, 42.3 g of phosphorus trichloride and 51.3 g of pentaerythritol were added. After magnetic stirring for 10 minutes, nitrogen was introduced into the apparatus and the mixture was refluxed in a 140°C oil bath for 6-8 hours until no hydrogen chloride gas was released and the reaction was complete. The mixture was extracted with boiling water and the sticky material at the bottom of the flask was removed by decantation. The mixture was concentrated to remove some water, and then cooled for crystallization, filtered, and dried to obtain reaction product A. B2. In a three-necked flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, 61.2 g of the reaction product A and 17.9 g of 3-aminopropyltrimethoxysilane were added. After magnetic stirring for 10 min, nitrogen was introduced to remove the air in the apparatus. The reaction temperature was then controlled at 130° C. and the fractional distillation reaction was carried out for 3 h. The temperature was continued to be raised until the temperature reached 150° C. and the fractional distillation reaction was carried out for 7 h. After the reaction was completed, the mixture was allowed to stand and cool, and then anhydrous ethanol was added with stirring to disperse the mixture. The mixture was then filtered and dried to obtain a reaction product B. B3. In a three-necked flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, 24.9 g of 3,5-di-tert-butyl-4-hydroxybenzoic acid and 150 mL of toluene were first mixed, placed in a 50°C water bath, and magnetically stirred until the solid was completely dissolved. Then, 67.3 g of the reaction product B and 20.6 g of dicyclohexylcarbodiimide were added in sequence. The reaction was stirred at this temperature for 6 h. After the reaction was completed, the mixture was naturally cooled, filtered, rotary evaporated, and purified by column chromatography to obtain a functional additive.
[0025] Example 2 Preparation of functional additives: B1. Add 42.3 g of phosphorus trichloride and 51.3 g of pentaerythritol to a three-necked flask equipped with a thermometer, a magnetic stirrer, and a reflux condenser. After magnetic stirring for 20 min, introduce nitrogen into the apparatus and reflux in a 150°C oil bath for 6-8 h until no more hydrogen chloride gas is released and the reaction is complete. Extract with boiling water, remove the sticky material at the bottom of the flask by decantation, concentrate to remove some water, cool and crystallize, filter with suction, and dry to obtain reaction product A. B2. In a three-necked flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, 61.2 g of the reaction product A and 17.9 g of 3-aminopropyltrimethoxysilane were added. After magnetic stirring for 20 min, nitrogen was introduced to remove the air in the apparatus. The reaction temperature was then controlled at 140° C. and the fractional distillation reaction was carried out for 4 h. The temperature was continued to be raised until the temperature reached 160° C. and the fractional distillation reaction was carried out for 8 h. After the reaction was completed, the mixture was allowed to stand and cool, and then anhydrous ethanol was added with stirring to disperse the mixture. The mixture was then filtered and dried to obtain a reaction product B. B3. In a three-necked flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, 24.9 g of 3,5-di-tert-butyl-4-hydroxybenzoic acid and 150 mL of toluene were first mixed, placed in a 55°C water bath, and magnetically stirred until the solid was completely dissolved. Then, 67.3 g of the reaction product B and 20.6 g of dicyclohexylcarbodiimide were added in sequence. The reaction was stirred at this temperature for 8 h. After the reaction was completed, the mixture was naturally cooled, filtered, rotary evaporated, and purified by column chromatography to obtain a functional additive.
[0026] Example 3 Preparation of rubber and plastic materials: A1. 42 g of acrylonitrile-butadiene rubber, 21 g of polyvinyl chloride and 10 g of EPDM were added to an internal mixer, and the mixture was masticated at 80 ° C. and 40 r / min for 10 min. 3 g of the functional agent prepared in Example 1, 5 g of dibutyl phthalate, 2 g of polyethylene wax, 4 g of azodicarbonamide and 1 g of dicumyl peroxide were then added in sequence, and mixing was continued at this temperature for 5 min to obtain a rubber mix. A2. The rubber mix obtained in step A1 is sheeted in an open mill, then added into a foaming furnace for free foaming, and discharged after cooling to obtain the main rubber and plastic material.
[0027] Example 4 Preparation of rubber and plastic materials: A1. Into an internal mixer, 49g of acrylonitrile-butadiene rubber, 25g of polyvinyl chloride and 15g of ethylene propylene diene monomer (EPDM) were added, and the mixture was masticated at 90°C and 50r / min for 15min. 6g of the functional agent prepared in Example 1, 7.5g of tributyl citrate, 3g of zinc stearate, 6g of dinitrosopentamethylenetetramine and 1.5g of sulfur were then added in sequence. Mixing was continued at this temperature for 10min to obtain a rubber mix. A2. The rubber mix obtained in step A1 is sheeted in an open mill, then added into a foaming furnace for free foaming, and discharged after cooling to obtain the main rubber and plastic material.
[0028] Example 5 Preparation of rubber and plastic materials: A1. 56 g of acrylonitrile-butadiene rubber, 29 g of polyvinyl chloride and 20 g of ethylene propylene diene monomer (EPDM) were added to an internal mixer, and the mixture was masticated at 100 ° C. and 60 r / min for 15 min. 9 g of the functional agent prepared in Example 1, 10 g of tributyl citrate, 4 g of epoxy soybean oil, 8 g of dinitrosopentamethylenetetramine and 2 g of sulfur were then added in sequence. Mixing was continued at this temperature for 10 min to obtain a rubber mix. A2. The rubber mix obtained in step A1 is sheeted in an open mill, then added into a foaming furnace for free foaming, and discharged after cooling to obtain the main rubber and plastic material.
[0029] Example 6 A method for preparing a composite rubber-plastic thermal insulation material comprises the following steps: A1. 56 g of acrylonitrile-butadiene rubber, 29 g of polyvinyl chloride and 20 g of ethylene propylene diene monomer (EPDM) were added to an internal mixer, and the mixture was masticated at 100 ° C. and 60 r / min for 15 min. 9 g of the functional agent prepared in Example 1, 10 g of tributyl citrate, 4 g of epoxy soybean oil, 8 g of dinitrosopentamethylenetetramine and 2 g of sulfur were then added in sequence. Mixing was continued at this temperature for 10 min to obtain a rubber mix. A2. The rubber mix obtained in step A1 is sheeted in an open mill, and then added to a foaming furnace for free foaming. After cooling, the material is discharged to obtain the main rubber-plastic material; A3. Pour polyurethane adhesive (Loctite UK 3131) into the trough of a coating machine and evenly apply the adhesive to one side of the carbon fiber cloth (0.5 mm thick) and one side of the main rubber-plastic material obtained in step A2 using a roller coating method. Then, with the coated surfaces facing each other, the materials are laminated using a laminating machine to obtain a composite rubber-plastic thermal insulation material.
[0030] Comparative Example 1 Commercially available tricresyl phosphate was used as a phosphorus-based flame retardant to replace the functional additive in Example 5. The remaining steps were the same as in Example 5 to prepare the material.
[0031] Comparative Example 2 Use unmodified ordinary nitrile rubber.
[0032] The performance tests of Examples 3, 4, 5 and Comparative Examples 1 and 2 were carried out, and the results are shown in the following table:
[0033] As can be seen from the above table, the flame retardancy and antioxidant properties of the main rubber-plastic material prepared in the embodiment of the present invention are higher than those of the comparative example. Therefore, using it as one of the components of the thermal insulation material can improve the flame retardancy and antioxidant properties of the thermal insulation material. Therefore, the present invention has important application value in the field of thermal insulation material technology.
[0034] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A composite rubber-plastic thermal insulation material, comprising a main rubber-plastic material and a carrier carbon fiber cloth, the two being bonded together by an adhesive, characterized in that: The main rubber-plastic material comprises the following raw materials in parts by weight: 42-56 parts of nitrile rubber, 21-29 parts of polyvinyl chloride, 10-20 parts of EPDM rubber, 3-9 parts of functional additives, 4-8 parts of foaming agent, 1-2 parts of vulcanizing agent, 5-10 parts of plasticizer and 2-4 parts of lubricant.
2. The composite rubber-plastic thermal insulation material according to claim 1, characterized in that: The functional additive is prepared by the following steps: B1. Add trichlorothiophosphorus and pentaerythritol to a flask, stir, introduce nitrogen, and reflux at 140-150°C for 6-8 hours until no hydrogen chloride gas is released and the reaction is complete to obtain reaction product A; B2. Add reaction product A and 3-aminopropyltrimethoxysilane to a flask, stir, introduce nitrogen, and carry out fractional distillation reaction at 130-140°C for 3-4 hours. Then, raise the temperature to 150-160°C and carry out fractional distillation reaction for 7-8 hours. The reaction is completed to obtain reaction product B. B3. In a flask, mix 3,5-di-tert-butyl-4-hydroxybenzoic acid and toluene, stir at 50-55°C until the solid is completely dissolved, then add the reaction product B and dicyclohexylcarbodiimide, stir at this temperature for 6-8 hours, and the reaction is completed to obtain a functional additive.
3. The composite rubber-plastic thermal insulation material according to claim 2, characterized in that: In step B1, the ratio of pentaerythritol to phosphorus trichloride is 17.1 g:14.1 g.
4. The composite rubber-plastic thermal insulation material according to claim 2, characterized in that: In step B2, the ratio of the amount of reaction product A to that of 3-aminopropyltrimethoxysilane is 61.2 g:17.9 g.
5. The composite rubber-plastic thermal insulation material according to claim 2, characterized in that: In step B3, the ratio of 3,5-di-tert-butyl-4-hydroxybenzoic acid, toluene, reaction product B, and dicyclohexylcarbodiimide is 24.9 g:150 mL:67.3 g:20.6 g.
6. The composite rubber-plastic thermal insulation material according to claim 1, characterized in that: The adhesive is one of a polyurethane adhesive, an epoxy resin adhesive and an acrylate adhesive.
7. The composite rubber-plastic thermal insulation material according to claim 1, characterized in that: The foaming agent is one of azodicarbonamide and dinitrosopentamethylenetetramine.
8. The composite rubber-plastic thermal insulation material according to claim 1, characterized in that: The vulcanizing agent is one of dicumyl peroxide and sulfur.
9. The composite rubber-plastic thermal insulation material according to claim 1, characterized in that: The plasticizer is one of dibutyl phthalate and tributyl citrate.
10. The method for preparing a composite rubber-plastic thermal insulation material according to any one of claims 1 to 9, characterized in that: The following steps are involved: A1. Add nitrile rubber, polyvinyl chloride and EPDM rubber to an internal mixer, perform plasticization, and then sequentially add functional additives, plasticizers, lubricants, foaming agents and vulcanizing agents, and continue mixing at this temperature to obtain a rubber mix; A2. The rubber mix obtained in step A1 is sheeted in an open mill, and then added to a foaming furnace for free foaming. After cooling, the material is discharged to obtain the main rubber-plastic material; A3. Pour the adhesive into the trough of the coating machine and evenly apply the adhesive to one side of the carbon fiber cloth and one side of the main rubber-plastic material obtained in step A2 by roller coating. Then, place the coated surfaces facing each other and compound them using a compounding machine to obtain a composite rubber-plastic thermal insulation material.