Anti-aging and low-temperature-resistant PVC foaming material with flexibility and strength and preparation method of anti-aging and low-temperature-resistant PVC foaming material

Abstract

The invention discloses an anti-aging and low-temperature-resistant PVC (polyvinyl chloride) foaming material with flexibility and strength and a preparation method of the anti-aging and low-temperature-resistant PVC foaming material. Comprising the following components: 60-80 parts of polyvinyl chloride resin, 10-20 parts of chlorinated polyethylene (CPE), 5-15 parts of ethylene-vinyl acetate copolymer (EVA), 20-35 parts of a composite plasticizer, 5-12 parts of nano calcium carbonate, 3-8 parts of modified montmorillonite, 6-12 parts of a composite stabilizer, 3-7 parts of a foaming agent, 1-3 parts of a cross-linking agent, 1-3 parts of an antioxidant, 0.5-2 parts of an ultraviolet light absorber, 5-10 parts of a cold-resistant plasticizer and 1-3 parts of a lubricant. According to the invention, the raw material components and the ratio are reasonably selected, so that the prepared PVC foaming material has good flexibility and strength. The addition of chlorinated polyethylene and ethylene-vinyl acetate copolymer can improve the flexibility of the material, the addition of nano calcium carbonate and modified montmorillonite enhances the strength of the material, and the use of the composite plasticizer also plays a positive role in the balance of flexibility and strength.

Description

Technical Field

[0001] This invention relates to the field of PVC foam materials technology, specifically to an anti-aging and low-temperature resistant PVC foam material that combines flexibility and strength, and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) foam materials are widely used in construction, automotive, packaging, and furniture industries due to their excellent properties such as light weight, heat insulation, sound insulation, and shock absorption. However, traditional PVC foam materials have some shortcomings. They are difficult to balance between flexibility and strength, and their anti-aging and low-temperature resistance are poor, which limits their application in some special environments. In terms of flexibility, a large amount of plasticizer is usually added to improve the flexibility of PVC foam materials, but this often leads to a decrease in the material's strength. Conversely, reducing the amount of plasticizer to increase strength will worsen the material's flexibility. Furthermore, PVC molecules contain chlorine atoms, which are prone to degradation under conditions such as light and high temperatures, leading to material aging and performance decline. Additionally, in low-temperature environments, traditional PVC foam materials tend to become brittle, with a significant reduction in flexibility, affecting their performance. Therefore, developing a PVC foam material that can simultaneously possess good flexibility and strength, as well as excellent anti-aging and low-temperature resistance properties, has significant practical implications and broad application prospects. Thus, this invention proposes an anti-aging and low-temperature resistant PVC foam material that combines flexibility and strength, along with its preparation method, to solve the aforementioned problems. Summary of the Invention

[0003] (a) Technical problems to be solved Regarding the flexibility of existing technologies, a large amount of plasticizer is usually added to improve the flexibility of PVC foam materials, but this often leads to a decrease in the material's strength. Conversely, reducing the amount of plasticizer to increase strength results in a decrease in the material's flexibility. Furthermore, the chlorine atoms in the PVC molecular structure are prone to degradation under conditions such as light and high temperatures, leading to material aging and performance decline. Additionally, in low-temperature environments, traditional PVC foam materials tend to become brittle, with a significant reduction in flexibility, affecting their performance.

[0004] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a flexible and strong anti-aging and low-temperature resistant PVC foam material, comprising the following components by weight: The composition includes: 60-80 parts polyvinyl chloride resin, 10-20 parts chlorinated polyethylene (CPE), 5-15 parts ethylene-vinyl acetate copolymer (EVA), 20-35 parts composite plasticizer, 5-12 parts nano calcium carbonate, 3-8 parts modified montmorillonite, 6-12 parts composite stabilizer, 3-7 parts foaming agent, 1-3 parts crosslinking agent, 1-3 parts antioxidant, 0.5-2 parts ultraviolet absorber, 5-10 parts cold-resistant plasticizer, and 1-3 parts lubricant. The composite plasticizer is composed of dioctyl phthalate (DOP), dioctyl adipate (DOA), and epoxidized soybean oil in a weight ratio of 3:2:1. The composite stabilizer is composed of calcium-zinc stabilizer, barium stearate, and phosphite in a weight ratio of 4:2:1. The modified montmorillonite is a composite modified montmorillonite with γ-aminopropyltriethoxysilane (KH550) and maleic anhydride grafted polyethylene (PE-g-MAH), wherein the weight ratio of KH550 to PE-g-MAH is 1:2-3. The cold-resistant plasticizer is a compound of dioctyl sebacate (DOS) and trioctyl trimellitate (TOTM) in a weight ratio of 2:1.

[0005] Preferably, the polyvinyl chloride resin is a compound of SG-3 type and SG-5 type PVC resin in a weight ratio of 1:1-2, wherein the average degree of polymerization of SG-3 type PVC resin is 1300-1500 and the average degree of polymerization of SG-5 type PVC resin is 800-1000.

[0006] Preferably, the foaming agent is a mixture of azodicarbonamide (AC) and sodium bicarbonate in a weight ratio of 3:1, and the AC foaming agent is surface treated with zinc stearate at a temperature of 60-80°C for 30-60 minutes.

[0007] Preferably, the crosslinking agent is a mixture of triallyl isocyanurate (TAIC) and dicumyl peroxide (DCP) in a weight ratio of 2:1, wherein the active oxygen content of DCP is ≥5.8%.

[0008] Preferably, the antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1; the ultraviolet absorber is a compound of ultraviolet absorber UV-531 and UV-327 in a weight ratio of 2:1.

[0009] Preferably, the lubricant is a compound of stearic acid, butyl stearate, and polyethylene wax in a weight ratio of 2:1:1, wherein the molecular weight of the polyethylene wax is 2000-5000.

[0010] This invention also proposes a method for preparing an anti-aging and low-temperature resistant PVC foam material that combines flexibility and strength, comprising the following steps: Step 1: Pretreatment of modified montmorillonite: Add montmorillonite to deionized water, stir and disperse to form a suspension with a mass fraction of 5-10%, sonicate for 30-60 min (power 300-500W), then add an ethanol solution of γ-aminopropyltriethoxysilane (KH550) and maleic anhydride grafted polyethylene (PE-g-MAH) (ethanol to water volume ratio 1:3), stir and react at 70-80℃ for 2-3 h, filter and wash until neutral, dry at 80-100℃ and grind through a 200 mesh sieve to obtain modified montmorillonite; Step 2: High-speed mixing: Add polyvinyl chloride resin, chlorinated polyethylene, and ethylene-vinyl acetate copolymer to a high-speed mixer and stir at 800-1000 r / min for 5-10 min. Then add composite stabilizer and lubricant in sequence, heat to 80-90℃, and stir for 10-15 min. Next, add composite plasticizer and cold-resistant plasticizer, and continue stirring for 5-8 min. Then add nano calcium carbonate and modified montmorillonite prepared in Step 1, heat to 100-110℃, and stir for 15-20 min. Finally, add antioxidant, ultraviolet absorber, crosslinking agent, and surface-treated foaming agent, and stir at 600-800 r / min for 5-10 min. Discharge the mixture to a cooling mixer and cool to 40-50℃ to obtain the mixture. Step 3: Melting and plasticizing: Add the mixture obtained in Step 2 into a twin-screw extruder, set the temperature of each section of the extruder as follows: feeding section 140-150℃, compression section 150-160℃, melting section 160-170℃, die head section 155-165℃, and screw speed 30-50 r / min. After melting and plasticizing, extrude and granulate to obtain PVC foaming masterbatch. Step 4: Foaming and molding: Add PVC foaming masterbatch to a single-screw extruder, set the temperature of each section of the extruder as follows: feeding section 110-120℃, compression section 130-140℃, foaming section 160-170℃, die head section 150-160℃, and screw speed 20-40 r / min. After extrusion through the die, it is naturally cooled to obtain the PVC foamed material.

[0011] Preferably, the twin-screw extruder in step 3 has a length-to-diameter ratio of 36:1 and is equipped with 4 vacuum exhaust ports with a vacuum degree of -0.08 to -0.09 MPa.

[0012] Preferably, in step 4, the mold is a flat mold, the mold temperature is controlled at 165-175℃, the die gap is 1-3mm, and after extrusion, a cooling method combining air cooling and water cooling is adopted. First, it is air-cooled to 80-100℃, and then water-cooled to room temperature, with a cooling rate of 5-10℃ / min.

[0013] (III) Beneficial Effects Compared with the prior art, the present invention provides an anti-aging and low-temperature resistant PVC foam material that combines flexibility and strength, and a method for its preparation, which has the following beneficial effects: This invention, through the rational selection and proportioning of raw material components, enables the preparation of PVC foam materials that possess both good flexibility and strength. The addition of chlorinated polyethylene and ethylene-vinyl acetate copolymer improves the material's flexibility, while the addition of nano-calcium carbonate and modified montmorillonite enhances the material's strength. The use of composite plasticizers also plays a positive role in balancing flexibility and strength. The combined use of antioxidants and ultraviolet absorbers significantly improves the anti-aging properties of materials, reduces degradation under conditions such as light and high temperature, and extends the service life of materials. The addition of cold-resistant plasticizers and a reasonable preparation process give the material excellent low-temperature resistance, and it can still maintain good flexibility and mechanical properties in low-temperature environments. The preparation method of the present invention is simple, easy to operate and industrialized, and the performance stability of the material is guaranteed by optimizing the process parameters of each step. Detailed Implementation

[0014] In this invention, unless otherwise stated, the directional terms such as "up" and "down" generally refer to the direction shown, or to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" generally refer to the left and right shown; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0015] This invention provides a technical solution for an anti-aging and low-temperature resistant PVC foam material that combines flexibility and strength, as well as a method for its preparation: Example 1 A flexible and strong anti-aging and low-temperature resistant PVC foam material, by weight, comprises the following components: 60 parts of polyvinyl chloride resin (SG-3 and SG-5 PVC resins are blended in a 1:1 weight ratio, with SG-3 having an average degree of polymerization of 1300 and SG-5 having an average degree of polymerization of 800), 10 parts of chlorinated polyethylene, 5 parts of ethylene-vinyl acetate copolymer, 20 parts of composite plasticizer (dioctyl phthalate, dioctyl adipate, and epoxidized soybean oil are blended in a 3:2:1 weight ratio), 5 parts of nano-calcium carbonate, 3 parts of modified montmorillonite (modified by γ-aminopropyltriethoxysilane and maleic anhydride grafted polyethylene in a 1:2 weight ratio), and 6 parts of composite stabilizer (calcium-zinc stabilizer, barium stearate, and phosphite are blended in a 4:2:1 weight ratio). The following components are used: foaming agent (3 parts by weight: azodicarbonamide and sodium bicarbonate, AC foaming agent surface treated with zinc stearate at 60℃ for 30 min), crosslinking agent (1 part by weight: triallyl isocyanurate and dicumyl peroxide, DCP active oxygen content 5.8%), antioxidant (1 part by weight: antioxidant 1010 and antioxidant 168, 1:1 by weight), ultraviolet absorber (0.5 parts by weight: ultraviolet absorber UV-531 and UV-327, 2:1 by weight), cold-resistant plasticizer (5 parts by weight: dioctyl sebacate and trioctyl trimellitate, 2:1 by weight), lubricant (1 part by weight: stearic acid, butyl stearate, and polyethylene wax, 2:1:1 by weight, polyethylene wax molecular weight 2000). Its preparation method is as follows: Step 1: Pretreatment of modified montmorillonite: Add montmorillonite to deionized water, stir and disperse to form a 5% (w / w) suspension, sonicate for 30 min (300W), then add an ethanol solution of γ-aminopropyltriethoxysilane and maleic anhydride grafted polyethylene (ethanol to water volume ratio 1:3), stir and react at 70℃ for 2 h, filter, wash until neutral, dry at 80℃, and grind through a 200-mesh sieve to obtain modified montmorillonite. Step 2: High-speed mixing: Add polyvinyl chloride resin, chlorinated polyethylene, and ethylene-vinyl acetate copolymer to a high-speed mixer and stir at 800 r / min for 5 min. Then add composite stabilizer and lubricant in sequence, heat to 80℃, and stir for 10 min. Next, add composite plasticizer and cold-resistant plasticizer, and continue stirring for 5 min. Then add nano calcium carbonate and modified montmorillonite prepared in Step 1, heat to 100℃, and stir for 15 min. Finally, add antioxidant, ultraviolet absorber, crosslinking agent, and surface-treated foaming agent, stir at 600 r / min for 5 min, and discharge to a cooling mixer to cool to 40℃ to obtain the mixture. Step 3: Melting and plasticizing: The mixture obtained in Step 2 is added to a twin-screw extruder with a length-to-diameter ratio of 36:1 and four vacuum exhaust ports (vacuum degree -0.08MPa). The temperatures of each section of the extruder are set as follows: feeding section 140℃, compression section 150℃, melting section 160℃, and die head section 155℃. The screw speed is 30r / min. After melting and plasticizing, the mixture is extruded and granulated to obtain PVC foam masterbatch. Step 4: Foaming and Molding: Add PVC foaming masterbatch to a single-screw extruder, set the temperature of each section of the extruder as follows: feeding section 110℃, compression section 130℃, foaming section 160℃, die head section 150℃, screw speed 20r / min, after extrusion through a flat die (temperature 165℃, die gap 1mm), first air-cool to 80℃, then water-cool to room temperature (cooling rate 5℃ / min) to obtain the PVC foamed material. Example 2 A flexible and strong anti-aging and low-temperature resistant PVC foam material, by weight, comprises the following components: 70 parts of polyvinyl chloride resin (SG-3 and SG-5 PVC resins compounded in a weight ratio of 1:1.5, with SG-3 having an average degree of polymerization of 1400 and SG-5 having an average degree of polymerization of 900), 15 parts of chlorinated polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 28 parts of composite plasticizer (dioctyl phthalate, dioctyl adipate, and epoxidized soybean oil compounded in a weight ratio of 3:2:1), 8 parts of nano-calcium carbonate, 5 parts of modified montmorillonite (modified by grafting γ-aminopropyltriethoxysilane and maleic anhydride onto polyethylene in a weight ratio of 1:2.5), and 9 parts of composite stabilizer (calcium-zinc stabilizer, barium stearate, and phosphite in a weight ratio of 4:2). :1 compound), 5 parts foaming agent (azodicarbonamide and sodium bicarbonate compounded in a weight ratio of 3:1, AC foaming agent surface treated with zinc stearate at 70℃ for 45min), 2 parts crosslinking agent (triallyl isocyanurate and dicumyl peroxide compounded in a weight ratio of 2:1, DCP active oxygen content 6.0%), 2 parts antioxidant (antioxidant 1010 and antioxidant 168 compounded in a weight ratio of 1:1), 1.2 parts ultraviolet absorber (ultraviolet absorber UV-531 and UV-327 compounded in a weight ratio of 2:1), 8 parts cold-resistant plasticizer (dioctyl sebacate and trioctyl trimellitate compounded in a weight ratio of 2:1), 2 parts lubricant (stearic acid, butyl stearate and polyethylene wax compounded in a weight ratio of 2:1:1, polyethylene wax molecular weight 3500). Its preparation method is as follows: Step 1: Pretreatment of modified montmorillonite: Add montmorillonite to deionized water, stir and disperse to form a suspension with a mass fraction of 8%, sonicate for 45 min (power 400W), then add an ethanol solution of γ-aminopropyltriethoxysilane and maleic anhydride grafted polyethylene (ethanol to water volume ratio 1:3), stir and react at 75℃ for 2.5 h, filter, wash until neutral, dry at 90℃, and grind through a 200 mesh sieve to obtain modified montmorillonite. Step 2: High-speed mixing: Add polyvinyl chloride resin, chlorinated polyethylene, and ethylene-vinyl acetate copolymer to a high-speed mixer and stir at 900 r / min for 8 min. Then add composite stabilizer and lubricant in sequence, heat to 85℃, and stir for 13 min. Next, add composite plasticizer and cold-resistant plasticizer, and continue stirring for 6 min. Then add nano calcium carbonate and modified montmorillonite prepared in Step 1, heat to 105℃, and stir for 18 min. Finally, add antioxidant, ultraviolet absorber, crosslinking agent, and surface-treated foaming agent, stir at 700 r / min for 8 min, and discharge to a cooling mixer to cool to 45℃ to obtain the mixture. Step 3: Melting and plasticizing: The mixture obtained in Step 2 is added to a twin-screw extruder with a length-to-diameter ratio of 36:1 and four vacuum exhaust ports (vacuum degree -0.085MPa). The temperatures of each section of the extruder are set as follows: feeding section 145℃, compression section 155℃, melting section 165℃, and die head section 160℃. The screw speed is 40r / min. After melting and plasticizing, the mixture is extruded and granulated to obtain PVC foam masterbatch. Step 4: Foaming and Molding: Add PVC foaming masterbatch to a single-screw extruder, set the temperature of each section of the extruder as follows: feeding section 115℃, compression section 135℃, foaming section 165℃, die head section 155℃, screw speed 30r / min, after extrusion through a flat die (temperature 170℃, die gap 2mm), first air-cool to 90℃, then water-cool to room temperature (cooling rate 8℃ / min) to obtain the PVC foamed material. The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A flexible and strong anti-aging and low-temperature resistant PVC foam material, characterized in that: By weight, it includes the following components: The composition includes: 60-80 parts polyvinyl chloride resin, 10-20 parts chlorinated polyethylene, 5-15 parts ethylene-vinyl acetate copolymer, 20-35 parts composite plasticizer, 5-12 parts nano calcium carbonate, 3-8 parts modified montmorillonite, 6-12 parts composite stabilizer, 3-7 parts foaming agent, 1-3 parts crosslinking agent, 1-3 parts antioxidant, 0.5-2 parts ultraviolet absorber, 5-10 parts cold-resistant plasticizer, and 1-3 parts lubricant. The composite plasticizer is composed of dioctyl phthalate, dioctyl adipate, and epoxidized soybean oil in a weight ratio of 3:2:

1. The composite stabilizer is composed of calcium-zinc stabilizer, barium stearate, and phosphite in a weight ratio of 4:2:

1. The modified montmorillonite is a composite modified montmorillonite grafted with γ-aminopropyltriethoxysilane and maleic anhydride onto polyethylene, wherein the weight ratio of KH550 to PE-g-MAH is 1:2-3. The cold-resistant plasticizer is a compound of dioctyl sebacate and trioctyl trimellitate in a weight ratio of 2:

1.

2. The aging-resistant and low-temperature-resistant PVC foam material with both flexibility and strength according to claim 1, characterized in that: The polyvinyl chloride resin is a compound of SG-3 type and SG-5 type PVC resin in a weight ratio of 1:1-2, wherein the average degree of polymerization of SG-3 type PVC resin is 1300-1500 and the average degree of polymerization of SG-5 type PVC resin is 800-1000.

3. The aging-resistant and low-temperature-resistant PVC foam material with both flexibility and strength according to claim 1, characterized in that: The foaming agent is a compound of azodicarbonamide and sodium bicarbonate in a weight ratio of 3:1, and the AC foaming agent is surface treated with zinc stearate at a temperature of 60-80℃ for 30-60 minutes.

4. The aging-resistant and low-temperature-resistant PVC foam material with both flexibility and strength according to claim 1, characterized in that: The crosslinking agent is a compound of triallyl isocyanurate and dicumyl peroxide in a weight ratio of 2:1, wherein the active oxygen content of DCP is ≥5.8%.

5. The aging-resistant and low-temperature-resistant PVC foam material with both flexibility and strength according to claim 1, characterized in that: The antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1; the ultraviolet absorber is a compound of ultraviolet absorber UV-531 and UV-327 in a weight ratio of 2:

1.

6. The aging-resistant and low-temperature-resistant PVC foam material with both flexibility and strength according to claim 1, characterized in that: The lubricant is a compound of stearic acid, butyl stearate, and polyethylene wax in a weight ratio of 2:1:1, wherein the molecular weight of the polyethylene wax is 2000-5000.

7. A method for preparing an anti-aging and low-temperature resistant PVC foam material with both flexibility and strength as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Pretreatment of modified montmorillonite: Add montmorillonite to deionized water, stir and disperse to form a suspension with a mass fraction of 5-10%, sonicate for 30-60 min, then add an ethanol solution of γ-aminopropyltriethoxysilane and maleic anhydride grafted polyethylene, stir and react at 70-80℃ for 2-3 h, filter and wash until neutral, dry at 80-100℃ and grind through a 200 mesh sieve to obtain modified montmorillonite; Step 2: High-speed mixing: Add polyvinyl chloride resin, chlorinated polyethylene, and ethylene-vinyl acetate copolymer to a high-speed mixer and stir at 800-1000 r / min for 5-10 min. Then add composite stabilizer and lubricant in sequence, heat to 80-90℃, and stir for 10-15 min. Next, add composite plasticizer and cold-resistant plasticizer, and continue stirring for 5-8 min. Then add nano calcium carbonate and modified montmorillonite prepared in Step 1, heat to 100-110℃, and stir for 15-20 min. Finally, add antioxidant, ultraviolet absorber, crosslinking agent, and surface-treated foaming agent, and stir at 600-800 r / min for 5-10 min. Discharge the mixture to a cooling mixer and cool to 40-50℃ to obtain the mixture. Step 3: Melting and plasticizing: Add the mixture obtained in Step 2 into a twin-screw extruder, set the temperature of each section of the extruder as follows: feeding section 140-150℃, compression section 150-160℃, melting section 160-170℃, die head section 155-165℃, and screw speed 30-50 r / min. After melting and plasticizing, extrude and granulate to obtain PVC foaming masterbatch. Step 4: Foaming and molding: Add PVC foaming masterbatch to a single-screw extruder, set the temperature of each section of the extruder as follows: feeding section 110-120℃, compression section 130-140℃, foaming section 160-170℃, die head section 150-160℃, and screw speed 20-40 r / min. After extrusion through the die, it is naturally cooled to obtain the PVC foamed material.

8. The preparation method according to claim 7, characterized in that, In step 3, the twin-screw extruder has a length-to-diameter ratio of 36:1 and is equipped with 4 vacuum exhaust ports with a vacuum degree of -0.08 to -0.09 MPa.

9. The preparation method according to claim 7, characterized in that, In step 4, the mold is a flat mold, the mold temperature is controlled at 165-175℃, the die gap is 1-3mm, and after extrusion, a cooling method combining air cooling and water cooling is adopted. First, it is air cooled to 80-100℃, and then water cooled to room temperature. The cooling rate is 5-10℃ / min.