High-strength plastic heat preservation nail and preparation method thereof

Abstract

The invention relates to the technical field of thermal insulation nails, and provides a high-strength plastic thermal insulation nail and a preparation method thereof, the high-strength plastic thermal insulation nail comprises the following raw materials by weight: 81-101 parts of polyamide 66, 12-24 parts of hydrophobic glass fiber, 4-6 parts of a flexibilizer, 5-10 parts of a thermal insulation filler, 0.5-1.5 parts of an antioxidant and 3-5 parts of a lubricant. The polyamide 66 is used as a base material, and the reinforcing effect of the hydrophobic glass fibers is combined, so that the mechanical strength and rigidity of the heat preservation nail are remarkably improved; through the combined action of the phosphite antioxidant and the hydrophobic glass fiber, the thermal aging resistance, the oxygen aging resistance and the ultraviolet aging resistance of the thermal insulation nail are improved; the hollow glass beads are added as a heat-preservation filler, so that the heat-preservation and heat-insulation performance of the heat-preservation nail is improved; in conclusion, the problems that a traditional plastic heat preservation nail is insufficient in strength and poor in weather resistance are solved, meanwhile, the heat preservation performance is considered, and important application value is achieved in the field of building energy saving.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation nails, and in particular to a high-strength plastic thermal insulation nail and a preparation method thereof. Background Art

[0002] In the field of building energy conservation and insulation engineering, insulation nails are key components that connect insulation panels to the base wall. Their performance directly affects the safety and durability of the entire insulation system. As the construction industry's requirements for insulation material performance continue to increase, the limitations of traditional insulation nails in terms of strength, durability, and thermal insulation effectiveness have become increasingly apparent, making them unable to meet the high construction standards of modern buildings.

[0003] Currently, the insulation nails widely used in the market are primarily made of metal and ordinary plastic. While metal insulation nails offer high mechanical strength, their high thermal conductivity can easily form thermal bridges, leading to heat loss and reducing the overall insulation performance of a building. Furthermore, metal is prone to rust and corrosion in humid environments, compromising the connection strength between the insulation nails and the wall and insulation board, posing a safety hazard of insulation loss. Consequently, plastic insulation nails are gaining increasing attention in the industry.

[0004] Ordinary plastic insulation nails are mostly made of conventional plastic materials such as polyvinyl chloride (PVC) and polypropylene (PP). Although they effectively avoid the problem of cold and hot bridges, due to the poor mechanical properties of the material itself, they are prone to breakage and deformation when subjected to large external forces or long-term use. Especially in the insulation projects of high-rise building exterior walls, faced with complex working conditions such as wind loads and stresses caused by temperature changes, ordinary plastic insulation nails are difficult to ensure the long-term stability of the insulation system. In addition, ordinary plastic insulation nails are also insufficient in terms of weather resistance. After long-term ultraviolet radiation and heat, the material is prone to aging, further weakening its connection strength and shortening the service life of the insulation system. In view of these industry difficulties, there is an urgent need to invent a high-strength, aging-resistant plastic insulation nail to meet the higher demands in the field of insulation nail technology. Summary of the Invention

[0005] The present invention provides a high-strength plastic thermal insulation nail and a preparation method thereof, which solves the problem of poor weather resistance and mechanical properties of the plastic thermal insulation nail in the related art.

[0006] The technical solutions of the present invention are as follows: The invention provides a high-strength plastic insulation nail, which comprises the following raw materials in parts by weight: 81-101 parts of polyamide 66, 12-24 parts of hydrophobic glass fiber, 4-6 parts of toughening agent, 5-10 parts of insulation filler, 0.5-1.5 parts of antioxidant and 3-5 parts of lubricant.

[0007] As a further technical solution, the toughening agent is one of ethylene-octene copolymer and ethylene-vinyl acetate copolymer.

[0008] As a further technical solution, the thermal insulation filler is hollow glass microspheres.

[0009] As a further technical solution, the antioxidant is a phosphite antioxidant.

[0010] As a further technical solution, the lubricant is one of polyethylene wax, stearic acid and oleamide.

[0011] Using polyamide 66 as a matrix imparts high strength, rigidity, and heat resistance to the insulation nails. The addition of a small amount of toughening agent prevents brittleness caused by excessive hardness. Hollow glass microspheres are hollow, spherical particles with an enclosed air cavity. Air has an extremely low thermal conductivity, making them an excellent thermal insulation material. When added to plastic insulation nails, the large, evenly distributed hollow glass microspheres act like miniature insulation units, forming a thermal resistance network within the nails. This significantly hinders heat transfer, reduces the overall thermal conductivity of the material, and thus enhances the insulation performance of the nails. The use of phosphite antioxidants improves the nails' resistance to oxygen aging.

[0012] As a further technical solution, the hydrophobic glass fiber is prepared by the following steps: Step A1: First, dissolve the silane coupling agent KH-550 in an ethanol-water solution (the volume ratio of ethanol to water is 4:1) to obtain a silane hydrolyzate. Then, heat-treat the chopped glass fiber at 400-500°C for 1-2 hours to remove organic residues on the surface and enhance the activity of the hydroxyl groups. Then, immerse the chopped glass fiber in the silane hydrolyzate and ultrasonically treat it in a water bath at 60°C for 30 minutes. Then, stir it for 2 hours, filter it, and vacuum-dry it to obtain the silane-modified glass fiber. As a further technical solution, in step A1, the ratio of the amount of silane coupling agent KH-550, ethanol aqueous solution, and chopped glass fiber is 3.2 g:100 mL:1 g.

[0013] In step A1, the chopped glass fibers are pre-modified using a silane coupling agent KH-550 to introduce active amino groups on the surface of the chopped glass fibers to prepare silane-modified glass fibers; Step A2, assemble a three-necked flask, a magnetic stirrer, and a condenser, replace the air with nitrogen, then add the reaction raw materials 4-amino-1,2,4-triazole, 1,3,5-trichlorobenzene, and solvent N,N-dimethylformamide to the flask, stir evenly, then add potassium carbonate, and then heat the reaction apparatus. When the temperature rises to 60°C, stir at this temperature for 6 hours. After the reaction is completed, filter, rotary evaporate, and then purify by column chromatography to obtain product A; As a further technical solution, in step A2, the ratio of 4-amino-1,2,4-triazole, 1,3,5-trichlorobenzene, N,N-dimethylformamide, and potassium carbonate is 8.4 g:20.3 g:100 mL:13.8 g.

[0014] In step A2, 4-amino-1,2,4-triazole and 1,3,5-trichlorobenzene undergo a nucleophilic substitution reaction under the catalysis of potassium carbonate, and the molar ratio of the two is 1:1. 1,3,5-trichlorobenzene is in excess to reduce side reactions. The reaction formula is as follows:

[0015] Step A3, assemble a four-necked flask, a magnetic stirrer, a condenser and a dropping funnel, replace the air with nitrogen, add the reaction raw material 2,4-dihydroxybenzophenone, product A and solvent toluene to the flask, use a magnetic stirrer to mix the raw materials evenly, then mix sodium hydroxide with distilled water, stir and dissolve, and then slowly add it dropwise to the flask through a dropping funnel. After the addition is complete, the temperature is raised to 65 ° C. and stirred at this temperature for 8 hours. After the reaction is complete, filter, rotary evaporate, and then purify by column chromatography to obtain product B; As a further technical solution, in step A3, the ratio of 2,4-dihydroxybenzophenone, product A, toluene, sodium hydroxide and distilled water is 21.4 g:24.6 g:150 mL:3.9 g:20 mL.

[0016] In step A3, sodium hydroxide can react with the hydroxyl group at the 4-position of the 2,4-dihydroxybenzophenone molecule to form sodium phenolate with stronger nucleophilicity. The hydroxyl group at the 2-position forms a hydrogen bond with the carbonyl group and is not easily broken. The sodium phenolate reacts with product A, and the molar ratio of product A to 2,2,4-dihydroxybenzophenone is 1:1. The amount of product A is excessive to reduce side reactions. The reaction formula is as follows:

[0017] Step A4: ultrasonically disperse the silane-modified glass fiber in N,N-dimethylformamide for 15 minutes, then add it to a three-necked flask equipped with a magnetic stirrer and a condenser, add product B and potassium carbonate, replace the air with nitrogen, and stir in a 50°C water bath for 12 hours. After the reaction is complete, remove the water bath, wait until the temperature drops to room temperature, filter, wash the filter residue with anhydrous ethanol several times, and vacuum dry to obtain a hydrophobic glass fiber; As a further technical solution, in step A4, the ratio of the amount of silane-modified glass fiber, N,N-dimethylformamide, product B, and potassium carbonate is 1 g:100 mL:5.6 g:2.2 g.

[0018] In step A4, the silane-modified glass fiber and the product B undergo a nucleophilic substitution reaction under the catalysis of potassium carbonate to obtain a hydrophobic glass fiber; Chopped glass fibers have very strong mechanical properties. The present invention improves the compatibility of glass fibers with organic matrices by hydrophobic modification of glass fibers, making them easier to disperse in the matrix, reducing agglomeration, and greatly improving the mechanical strength of the organic matrix. In addition, the hydrophobic glass fibers also contain triazole rings, benzene rings, and benzophenone groups. The triazole rings have a high nitrogen content and good heat resistance, which can improve the heat aging resistance of the matrix. Moreover, the benzene rings are rigid hydrophobic groups, and the introduction of multiple benzene rings further improves the heat resistance and mechanical strength of the matrix. Finally, the benzophenone group can absorb ultraviolet light and improve the light aging resistance of the matrix.

[0019] The present invention also provides a method for preparing a high-strength plastic insulation nail, comprising the following steps: Step B1, drying the polyamide 66 and hollow glass microspheres to remove moisture from the raw materials to prevent defects such as material degradation or bubbles caused by moisture during subsequent processing, thereby obtaining dried polyamide 66 and hollow glass microspheres; Step B2: adding dried polyamide 66 and hollow glass microspheres, hydrophobic glass fiber, toughening agent, antioxidant and lubricant to a high-speed mixer in sequence, and mixing them uniformly to obtain a premix; Step B3, adding the premix into a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch; Step B4: inject the plastic masterbatch into the mold through an injection molding machine. After the injection molding is completed, the product is taken out to obtain a high-strength plastic insulation nail.

[0020] As a further technical solution, the drying temperature in step B1 is 80-90° C. and the drying time is 6-8 hours.

[0021] As a further technical solution, in step B2, the rotation speed of the high-speed mixer is 800-1200 r / min, and the mixing time is 10-20 min.

[0022] As a further technical solution, the injection pressure of the injection molding in step B4 is 60-100 MPa, and the time is 10-20 s.

[0023] As a further technical solution, the temperature of the mold in step B4 is 60-80°C.

[0024] The working principle and beneficial effects of the present invention are: 1. The present invention uses polyamide 66 as the base material and combines the reinforcement effect of hydrophobic glass fiber to significantly improve the mechanical strength and rigidity of the insulation nail, enabling it to withstand greater external forces and be suitable for complex working conditions such as high-rise buildings; 2. The present invention improves the ability of the insulation nail to resist heat aging, oxygen aging and ultraviolet aging by adding phosphite antioxidant and hydrophobic glass fiber, thereby extending the service life; 3. The present invention adds hollow glass microspheres as thermal insulation fillers, which effectively reduces the thermal conductivity and improves the thermal insulation performance of the thermal insulation nails; In summary, the present invention solves the problems of insufficient strength and poor weather resistance of traditional plastic insulation nails, while taking into account the thermal insulation performance, and has important application value in the field of building energy conservation. DETAILED DESCRIPTION

[0025] 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.

[0026] Example 1 Preparation of hydrophobic glass fibers: Step A1: First, 3.2 g of silane coupling agent KH-550 was dissolved in 100 mL of ethanol-water solution (the volume ratio of ethanol to water was 4:1) to obtain a silane hydrolyzate. Then, 1 g of chopped glass fiber was heat-treated at 400°C for 1 hour to remove surface organic residues and enhance hydroxyl activity. The fiber was then immersed in the silane hydrolyzate and ultrasonically treated in a 60°C water bath for 30 minutes. The fiber was then stirred for 2 hours, filtered, and vacuum-dried to obtain a silane-modified glass fiber. Step A2, assemble a three-necked flask, a magnetic stirrer and a condenser, replace the air with nitrogen, then add 8.4g of the reaction raw materials 4-amino-1,2,4-triazole, 20.3g of 1,3,5-trichlorobenzene and 100mL of solvent N,N-dimethylformamide to the flask, stir evenly, then add 13.8g of potassium carbonate, and then heat the reaction apparatus. When the temperature rises to 60°C, stir at this temperature for 6h. After the reaction is complete, filter, rotary evaporate, and then purify by column chromatography to obtain product A; Step A3, assemble a four-necked flask, a magnetic stirrer, a condenser and a dropping funnel, replace the air with nitrogen, and then add 21.4g of 2,4-dihydroxybenzophenone, 24.6g of product A and 150mL of solvent toluene to the flask. Use a magnetic stirrer to mix the raw materials evenly, then mix 3.9g of sodium hydroxide with 20mL of distilled water, stir and dissolve, and then slowly add it dropwise to the flask through a dropping funnel. After the addition is complete, the temperature is raised to 65 ° C. and the reaction is stirred at this temperature for 8h. After the reaction is complete, filter, rotary evaporate, and then purify by column chromatography to obtain product B; Step A4, ultrasonically disperse 1 g of silane-modified glass fiber in 100 mL of N,N-dimethylformamide for 15 minutes, then add it to a three-necked flask equipped with a magnetic stirrer and a condenser, add 5.6 g of product B and 2.2 g of potassium carbonate, replace the air with nitrogen, and stir the reaction in a 50 ° C water bath for 12 hours. After the reaction is completed, remove the water bath, wait until the temperature drops to room temperature, filter, wash the filter residue with anhydrous ethanol several times, and vacuum dry to obtain hydrophobic glass fiber.

[0027] Example 2 Preparation of hydrophobic glass fibers: Step A1: First, 6.4 g of silane coupling agent KH-550 was dissolved in 200 mL of ethanol-water solution (the volume ratio of ethanol to water was 4:1) to obtain a silane hydrolyzate. Then, 2 g of chopped glass fiber was heat-treated at 500° C. for 2 h to remove surface organic residues and enhance hydroxyl activity. The fiber was then immersed in the silane hydrolyzate and ultrasonically treated in a 60° C. water bath for 30 min. The fiber was stirred for 2 h, filtered, and vacuum-dried to obtain a silane-modified glass fiber. Step A2, assemble a three-necked flask, a magnetic stirrer and a condenser, replace the air with nitrogen, then add 16.8g of the reaction raw materials 4-amino-1,2,4-triazole, 40.6g of 1,3,5-trichlorobenzene and 200mL of solvent N,N-dimethylformamide to the flask, stir evenly, then add 27.6g of potassium carbonate, and then heat the reaction apparatus. When the temperature rises to 60°C, stir at this temperature for 6h. After the reaction is completed, filter, rotary evaporate, and then purify by column chromatography to obtain product A; Step A3, assemble a four-necked flask, a magnetic stirrer, a condenser and a dropping funnel, replace the air with nitrogen, and then add 42.8g of the reaction raw material 2,4-dihydroxybenzophenone, 49.2g of product A and 300mL of solvent toluene to the flask. After the raw materials are evenly mixed using a magnetic stirrer, 7.8g of sodium hydroxide is mixed with 40mL of distilled water, stirred and dissolved, and then slowly added dropwise to the flask through a dropping funnel. After the addition is completed, the temperature is raised to 65 ° C. and the reaction is stirred at this temperature for 8h. After the reaction is completed, it is filtered, rotary evaporated, and then purified by column chromatography to obtain product B; Step A4, ultrasonically disperse 2 g of silane-modified glass fiber in 200 mL of N,N-dimethylformamide for 15 minutes, then add it to a three-necked flask equipped with a magnetic stirrer and a condenser, add 11.2 g of product B and 4.4 g of potassium carbonate, replace the air with nitrogen, and stir in a water bath at 50 ° C for 12 hours. After the reaction is completed, remove the water bath, wait until the temperature drops to room temperature, filter, wash the filter residue with anhydrous ethanol several times, and vacuum dry to obtain hydrophobic glass fiber.

[0028] Example 3 Preparation of plastic masterbatch: Step B1, drying 81 g of polyamide 66 and 5 g of hollow glass microspheres at 80° C. for 6 h to obtain dried polyamide 66 and hollow glass microspheres; Step B2: adding the dried polyamide 66 and hollow glass microspheres, 12 g of the hydrophobic glass fiber prepared in Example 1, 4 g of ethylene-octene copolymer, 0.5 g of antioxidant 168, and 3 g of polyethylene wax to a high-speed mixer in sequence, and mixing at a speed of 800 r / min for 10 min to obtain a premix; Step B3: adding the premix to a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch.

[0029] Example 4 Preparation of plastic masterbatch: Step B1, drying 91 g of polyamide 66 and 7.5 g of hollow glass microspheres at 80° C. for 7 h to obtain dried polyamide 66 and hollow glass microspheres; Step B2: Add the dried polyamide 66 and hollow glass microspheres, 18 g of the hydrophobic glass fiber prepared in Example 2, 5 g of ethylene-vinyl acetate copolymer, 1.0 g of antioxidant 168, and 4 g of stearic acid into a high-speed mixer in sequence, and mix at a speed of 1000 r / min for 15 min to obtain a premix; Step B3: adding the premix to a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch.

[0030] Example 5 Preparation of plastic masterbatch: Step B1, drying 101 g of polyamide 66 and 10 g of hollow glass microspheres at 90° C. for 8 h to obtain dried polyamide 66 and hollow glass microspheres; Step B2: Add the dried polyamide 66 and hollow glass microspheres, 24 g of the hydrophobic glass fiber prepared in Example 2, 6 g of ethylene-vinyl acetate copolymer, 1.5 g of antioxidant 168, and 5 g of oleamide into a high-speed mixer in sequence, and mix at a speed of 1200 r / min for 20 min to obtain a premix; Step B3: adding the premix to a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch.

[0031] Example 6 A method for preparing high-strength plastic insulation nails comprises the following steps: Step B1, drying 101 g of polyamide 66 and 10 g of hollow glass microspheres at 90° C. for 8 h to obtain dried polyamide 66 and hollow glass microspheres; Step B2: Add the dried polyamide 66 and hollow glass microspheres, 24 g of the hydrophobic glass fiber prepared in Example 2, 6 g of ethylene-vinyl acetate copolymer, 1.5 g of antioxidant 168, and 5 g of oleamide into a high-speed mixer in sequence, and mix at a speed of 1200 r / min for 20 min to obtain a premix; Step B3, adding the premix into a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch; Step B4: inject the plastic masterbatch into a mold at 80°C through an injection molding machine with an injection pressure of 100 MPa and a time of 20 seconds. After the injection molding is completed, the product is taken out to obtain a high-strength plastic insulation nail.

[0032] Comparative Example 1 Ordinary glass fiber was used to replace the hydrophobic glass fiber in Example 5, and the remaining steps were the same as in Example 5 to prepare the plastic masterbatch.

[0033] Comparative Example 2 Commercially available PA66 was used.

[0034] Examples 3, 4, 5, and Comparative Examples 1 and 2 were made into corresponding test shapes according to different test standards, and the following performance tests were performed: GB / T 1040.2-2006 was used to determine the tensile strength; GB / T 1634.2-2004 was used to measure heat deformation temperature (under a low load of 0.45 MPa); GB / T 16422.3-2014 was used to determine the tensile strength retention rate after 500 hours of UV aging; tensile strength retention rate = tensile strength after test / tensile strength before test × 100%; The measured results are shown in the following table:

[0035] As can be seen from the above table, the masterbatch prepared in the embodiment of the present invention has higher mechanical properties, heat resistance and light resistance than the comparative example due to the addition of homemade hydrophobic glass fiber. Therefore, the insulation nails prepared using it also have the same performance and have important application value in the field of building energy conservation.

[0036] 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 high-strength plastic insulation nail, characterized in that: The invention comprises the following raw materials in parts by weight: 81-101 parts of polyamide 66, 12-24 parts of hydrophobic glass fiber, 4-6 parts of toughening agent, 5-10 parts of thermal insulation filler, 0.5-1.5 parts of antioxidant and 3-5 parts of lubricant.

2. A high-strength plastic insulation nail according to claim 1, characterized in that: The hydrophobic glass fiber is prepared by the following steps: Step A1, dissolving a silane coupling agent KH-550 in an ethanol aqueous solution to obtain a silane hydrolyzate, then heat-treating the chopped glass fiber at 400-500° C. for 1-2 hours, then immersing the chopped glass fiber in the silane hydrolyzate, ultrasonically treating the fiber at 60° C. for 30 minutes, stirring the fiber for 2 hours, filtering the fiber, and drying the fiber to obtain a silane-modified glass fiber; Step A2: 4-amino-1,2,4-triazole, 1,3,5-trichlorobenzene, and N,N-dimethylformamide were added to a flask, stirred evenly, and then potassium carbonate was added. The mixture was stirred at 60° C. for 6 h. The reaction was completed to obtain product A. Step A3: Add 2,4-dihydroxybenzophenone, product A, and toluene to a flask and mix well. Then, mix sodium hydroxide with distilled water, stir to dissolve, and then add dropwise to the flask through a dropping funnel. After the addition is complete, react at 65° C. for 8 hours. After the reaction is complete, obtain product B. Step A4: ultrasonically disperse the silane-modified glass fiber in N,N-dimethylformamide for 15 minutes, then add it to the flask, add product B and potassium carbonate, and stir the reaction at 50°C for 12 hours. The reaction is completed to obtain hydrophobic glass fiber.

3. A high-strength plastic insulation nail according to claim 2, characterized in that: In step A1, the ratio of silane coupling agent KH-550, ethanol aqueous solution, and chopped glass fiber is 3.2 g:100 mL:1 g.

4. A high-strength plastic insulation nail according to claim 2, characterized in that: In step A2, the ratio of 4-amino-1,2,4-triazole, 1,3,5-trichlorobenzene, N,N-dimethylformamide, and potassium carbonate is 8.4 g:20.3 g:100 mL:13.8 g.

5. The high-strength plastic insulation nail according to claim 2, characterized in that: In step A3, the ratio of 2,4-dihydroxybenzophenone, product A, toluene, sodium hydroxide and distilled water is 21.4 g:24.6 g:150 mL:3.9 g:20 mL.

6. The high-strength plastic insulation nail according to claim 2, characterized in that: In step A4, the ratio of the amount of silane-modified glass fiber, N,N-dimethylformamide, product B, and potassium carbonate is 1 g:100 mL:5.6 g:2.2 g.

7. The high-strength plastic insulation nail according to claim 1, characterized in that: The toughening agent is one of ethylene-octene copolymer and ethylene-vinyl acetate copolymer.

8. The high-strength plastic insulation nail according to claim 1, characterized in that: The thermal insulation filler is hollow glass microspheres.

9. The high-strength plastic insulation nail according to claim 1, characterized in that: The antioxidant is a phosphite antioxidant.

10. A method for preparing a high-strength plastic insulation nail according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step B1, drying the polyamide 66 and the hollow glass microspheres to obtain dried polyamide 66 and the hollow glass microspheres; Step B2: adding dried polyamide 66 and hollow glass microspheres, hydrophobic glass fiber, toughening agent, antioxidant and lubricant to a high-speed mixer in sequence, and mixing them uniformly to obtain a premix; Step B3, adding the premix into a twin-screw extruder, performing melt blending, extrusion, water cooling, and pelletizing to obtain plastic masterbatch; Step B4: inject the plastic masterbatch into the mold through an injection molding machine. After the injection molding is completed, the product is taken out to obtain a high-strength plastic insulation nail.

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