PVC supercritical foam board and preparation method thereof

Abstract

The invention relates to the technical field of PVC (polyvinyl chloride), in particular to a PVC supercritical foam board and a preparation method thereof.The PVC supercritical foam board is prepared from, by weight, 60-100 parts of PVC resin powder, 1.2-5 parts of stabilizer, 5-10 parts of modifier, 0.1-0.5 part of foaming nucleating agent, 5-10 parts of foaming regulator, 0-100 parts of filler, 0.1-0.5 part of cross-linking agent and 0.1-2 parts of lubricant. The problem that ammonia gas and other unpleasant smells are generated in the production process of the PVC foam board is effectively solved, meanwhile, preparation of products with uniform foam holes, low density and high strength is achieved, and the high market popularization value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of PVC, in particular to a PVC supercritical foamed board and a preparation method thereof. Background Art

[0002] Rigid foamed crusted polyvinyl chloride (PVC) is known as "synthetic wood". The conventional production method is to use chemical foaming agents and various additives to produce it. Since the decomposition temperature of chemical foaming agents is generally around 200°C, polyvinyl chloride is easily degraded at this temperature. Moreover, the chemical foaming agent produces unpleasant odors such as ammonia during the decomposition process, resulting in unpleasant odors in the air during the board production process, which is very unfriendly to production employees, and the product has environmentally unfriendly factors such as formamide. In addition, the board pores produced by traditional chemical foaming of PVC are uneven, generally the middle pores are relatively coarse, and the pores on both sides are fine, resulting in the hardness of the board deteriorating and the strength being very poor when the PVC chemical foaming board is foamed to a relatively light density. Chinese patent application (publication number CN118755217A) discloses PVC foaming composition, its preparation method and application, mainly by introducing hydroxypropyl methylcellulose modified calcium carbonate filler, improving the bonding force of light calcium carbonate and PVC matrix and improving the impact strength and toughness of the rigid foaming system, but still cannot overcome the above-mentioned problems of chemical foaming agents. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a PVC supercritical foamed board, which is produced by a supercritical foaming process, effectively solving the problem of generating unpleasant odors such as ammonia during the production process of the PVC foamed board, and at the same time achieving the preparation of products with uniform pores, low density and high strength, and has high market promotion value.

[0004] On the one hand, the present invention provides a PVC supercritical foamed board. The raw materials for preparing the board include at least 60-100 parts of PVC resin powder, 1.2-5 parts of stabilizer, 5-10 parts of modifier, 0.1-0.5 parts of foaming nucleating agent, 5-10 parts of foaming regulator, 0-100 parts of filler, 0.1-0.5 parts of cross-linking agent and 0.1-2 parts of lubricant, calculated by weight.

[0005] As a preferred technical solution, the raw materials for preparing the PVC supercritical foamed board include at least 60-100 parts of PVC resin powder, 1.2-4 parts of stabilizer, 5-8 parts of modifier, 0.1-0.4 parts of foaming nucleating agent, 5-9 parts of foaming regulator, 0-80 parts of filler, 0.1-0.4 parts of cross-linking agent, and 0.1-1 parts of lubricant, by weight.

[0006] As a preferred technical solution, the raw materials for preparing the PVC supercritical foamed board include at least 80-100 parts of PVC resin powder, 1.2-3.2 parts of stabilizer, 6-8 parts of modifier, 0.1-0.3 parts of foaming nucleating agent, 5-8 parts of foaming regulator, 30-60 parts of filler, 0.1-0.3 parts of cross-linking agent, and 0.1-0.5 parts of lubricant, by weight.

[0007] As a preferred technical solution, the polymerization degree of the PVC resin powder is 1000-1300.

[0008] Preferably, the PVC resin powder is selected from at least one of SG8 type PVC resin powder and SG5 type PVC resin powder.

[0009] Preferably, the PVC resin powder is a combination of SG8 type PVC resin powder and SG5 type PVC resin powder, and the mass ratio of the SG8 type PVC resin powder to the SG5 type PVC resin powder is (1-2):(8-9).

[0010] As a preferred technical solution, the stabilizer is selected from at least one of a calcium zinc stabilizer, a barium zinc stabilizer, and a lead salt stabilizer.

[0011] Preferably, the stabilizer is a calcium zinc stabilizer or a barium zinc stabilizer.

[0012] As a preferred technical solution, the modifier is at least one of ultra-high molecular weight polyvinyl chloride, chlorinated polyethylene (CPE), and methyl methacrylate-butadiene-styrene copolymer (MBS).

[0013] Preferably, the degree of polymerization of the ultra-high molecular weight polyvinyl chloride is ≥2000.

[0014] As a preferred technical solution, the foaming nucleating agent is selected from at least one of nano-scale calcium carbonate, nano-scale talc, nano-scale glass powder, nano-scale clay and nano-scale quartz powder.

[0015] Preferably, the particle size of the foaming nucleating agent is 40-100 nm, preferably 40-80 nm.

[0016] As a preferred technical solution, the foaming regulator is an acrylic polymer, and the intrinsic viscosity of the acrylic polymer (GB / T1632.1-2008 standard) is 11-15 dL / g.

[0017] Preferably, the foaming regulator is selected from at least one of DL-530, DL-869, DL-628, DL-638, DL-668, DL-688, and DL-698, preferably DL-688.

[0018] As a preferred technical solution, the filler is selected from at least one of calcium carbonate, talcum powder, white carbon black, clay and quartz powder.

[0019] Preferably, the particle size of the filler is 400-1200 mesh.

[0020] Preferably, the filler is 400-1000 mesh calcium carbonate.

[0021] As a preferred technical solution, the crosslinking agent is at least one of diisobutyryl peroxide, 1,1,3,3-tetramethylbutyl peroxide-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and dimercapto-triazine compounds.

[0022] As a preferred technical solution, the lubricant is selected from at least one of paraffin, stearic acid, silicone powder, pentaerythritol stearate (PETS), and oxidized polyethylene wax, preferably one of paraffin, silicone powder, and pentaerythritol stearate (PETS).

[0023] The PVC supercritical foaming board provided by the present invention optimizes the formula system so that the provided formula material meets the production requirements of the PVC supercritical foaming process, and realizes the use of supercritical gas instead of chemical foaming agent for foaming to obtain the PVC supercritical foaming board. Compared with the traditional chemical foaming board, there is no unpleasant odor in the production process, and the board does not contain formamide. Specifically, by adopting PVC resin powder with a degree of polymerization of 1000-1300, in combination with stabilizers, modifiers, foaming nucleating agents, foaming regulators, and fillers, the board obtained under the supercritical foaming process has a higher whiteness, and the internal pores of the board are more delicate and uniform. Further, by controlling the addition amount of each raw material in the system and controlling the particle size of the filler, the provided foaming board has a lower density and higher impact strength relative to the traditional chemical foaming board, which better meets the actual application requirements.

[0024] On the other hand, the present invention provides a method for preparing a PVC supercritical foamed board, which comprises at least the following steps: stirring and premixing PVC resin powder, a filler, a modifier and a stabilizer to obtain a premix; adding a foaming nucleating agent, a foaming regulator, a crosslinking agent and a lubricant to the premix and stirring and mixing to obtain a mixture; adding the mixture into a PVC supercritical foamed board extruder and extruding and foaming to obtain the premix.

[0025] As a preferred technical solution, the stirring premixing temperature is 90-105°C, the time is 15-20min, and the stirring speed is 1800-3000r / min.

[0026] As a preferred technical solution, the stirring and mixing temperature is 45-60°C, the time is 15-30 minutes, and the stirring speed is 600-1300 r / min.

[0027] As a preferred technical solution, the process parameters of the PVC supercritical foaming board extruder include: supercritical carbon dioxide gas pressure of 10-12MPa; extruder temperature of 160-190°C.

[0028] The preparation method provided by the present invention has a simple process, avoids the problems of plate discoloration, insufficient foaming and PVC degradation during the production process, ensures product quality and greatly improves production efficiency, and is easy to realize large-scale industrial production.

[0029] Beneficial Effects

[0030] 1. The present invention provides a PVC supercritical foamed board, which is produced by a supercritical foaming process, effectively solving the problem of generating unpleasant odors such as ammonia during the production process of the PVC foamed board, and at the same time realizing the preparation of products with uniform pores, low density and high strength, and has high market promotion value.

[0031] 2. The PVC supercritical foamed board provided by the present invention optimizes the formula system so that the provided formula meets the production requirements of the PVC supercritical foaming process, and uses supercritical gas instead of chemical foaming agent for foaming to obtain the PVC supercritical foamed board. Compared with the traditional chemical foamed board, there is no unpleasant odor during the production process, and the board does not contain formamide.

[0032] 3. The present invention adopts PVC resin powder with a polymerization degree of 1000-1300, and combines stabilizers, modifiers, foaming nucleating agents, foaming regulators, and fillers. The board obtained under the supercritical foaming process has higher whiteness and more delicate and uniform pores inside the board.

[0033] 4. The present invention controls the addition amount of each raw material in the system and controls the particle size of the filler, so that the provided foam board has lower density and higher impact strength than the traditional chemical foam board, which better meets the actual application requirements.

[0034] 5. The preparation method provided by the present invention has a simple process, avoids problems such as discoloration of the plate, insufficient foaming and PVC degradation during the production process, ensures product quality and greatly improves production efficiency, and is easy to realize large-scale industrial production. DETAILED DESCRIPTION

[0035] Examples 1-4, Comparative Example 1

[0036] On the one hand, Examples 1-4 and Comparative Example 1 of the present invention provide PVC supercritical foamed boards, and the formula is shown in Table 1 in parts by weight.

[0037] Table 1

[0038]

[0039]

[0040] In Table 1: SG8PVC resin powder (polymerization degree 1200-1300) and SG5 PVC resin powder (polymerization degree 1000-1100) are both from Xinjiang Tianye Co., Ltd.; the brand of calcium zinc stabilizer is CZ-628, which is from Guangzhou Benqi New Materials Co., Ltd.; the brand of barium zinc stabilizer is BZ-300H, which is from Guangzhou Benqi New Materials Co., Ltd.; ultra-high molecular weight polyvinyl chloride (polymerization degree 2000-2500) is from Formosa Plastics Ningbo Co., Ltd.; the brand of CPE is 135A, which is from Shandao Chemical Co., Ltd.; the brand of MBS is The brand number of PETS is PETS-4, which comes from Guangzhou Jiadele Technology Co., Ltd.; the brand number of nano calcium carbonate is LH-1250, which comes from Dongguan Limao Chemical Co., Ltd.; the brand number of nano talc is BHS-2680, which comes from Quanzhou Xufeng Powder Raw Material Co., Ltd.; the brand number of nano glass powder is GS-2000, which comes from Guangdong Yufeng Powder Material Co., Ltd.; the filler comes from Dongguan Limao Chemical Co., Ltd.

[0041] On the other hand, embodiments 1-4 of the present invention provide a method for preparing a PVC supercritical foamed board, comprising the following steps: stirring and premixing PVC resin powder, a filler, a modifier and a stabilizer to obtain a premix; adding a foaming nucleating agent, a foaming regulator, a cross-linking agent and a lubricant to the premix, stirring and mixing to obtain a mixture; adding the mixture to a PVC supercritical foamed board extruder, and extruding and foaming the mixture to obtain the board; the stirring and premixing temperature is 100°C, the time is 20min, and the stirring speed is 2500r / min; the stirring and mixing temperature is 55°C, the time is 15min, and the stirring speed is 1300r / min; the process parameters of the PVC supercritical foamed board extruder include: a supercritical carbon dioxide gas pressure of 11MPa; the temperatures of extruder zones 1-8 are 163°C, 178°C, 175°C, 177°C, 181°C, 166°C, 175°C, and 168°C, respectively.

[0042] On the other hand, Comparative Example 1 of the present invention provides a preparation method of a PVC supercritical foamed board, comprising the following steps: stirring and premixing PVC resin powder, a filler, a modifier and a stabilizer to obtain a premix; adding a foaming nucleating agent, a foaming regulator, a cross-linking agent and a lubricant to the premix and stirring and mixing to obtain a mixture; adding the mixture to a PVC foam board twin-screw extruder, and extruding and foaming the mixture to obtain the mixture; the stirring premixing temperature is 100°C, the time is 20min, and the stirring speed is 2500r / min; the stirring mixing temperature is 55°C, the time is 15min, and the stirring speed is 600r / min; the process parameters of the PVC foam board twin-screw extruder include: the temperatures of extruder zones 1-8 are 163°C, 178°C, 175°C, 177°C, 181°C, 166°C, 175°C, and 168°C, respectively.

[0043] Performance Testing

[0044] 1. The foamed boards provided in the examples and comparative examples were subjected to the performance tests shown in Table 2. The test methods and test results are shown in Table 2.

[0045] Table 2

[0046]

Claims

1. A PVC supercritical foamed board, characterized in that: The raw materials for its preparation include at least 60-100 parts of PVC resin powder, 1.2-5 parts of stabilizer, 5-10 parts of modifier, 0.1-0.5 parts of foaming nucleating agent, 5-10 parts of foaming regulator, 0-100 parts of filler, 0.1-0.5 parts of crosslinking agent and 0.1-2 parts of lubricant by weight.

2. The PVC supercritical foamed board according to claim 1, characterized in that: The polymerization degree of the PVC resin powder is 1000-1300.

3. The PVC supercritical foamed board according to claim 1, characterized in that: The stabilizer is selected from at least one of a calcium zinc stabilizer, a barium zinc stabilizer, and a lead salt stabilizer.

4. The PVC supercritical foamed board according to claim 1, characterized in that: The modifier is at least one of ultra-high molecular weight polyvinyl chloride, chlorinated polyethylene, and methyl methacrylate-butadiene-styrene copolymer.

5. The PVC supercritical foamed board according to claim 4, characterized in that: The polymerization degree of the ultra-high molecular weight polyvinyl chloride is ≥2000.

6. The PVC supercritical foamed board according to claim 1, characterized in that: The foaming nucleating agent is selected from at least one of nano-scale calcium carbonate, nano-scale talc, nano-scale glass powder, nano-scale clay and nano-scale quartz powder.

7. The PVC supercritical foamed board according to claim 6, characterized in that: The particle size of the foaming nucleating agent is 40-100 nm.

8. The PVC supercritical foamed board according to claim 1, characterized in that: The foaming regulator is an acrylic polymer, and the intrinsic viscosity of the acrylic polymer is 11-15 dL / g.

9. The PVC supercritical foamed board according to claim 1, characterized in that: The filler is selected from at least one of calcium carbonate, talc, white carbon black, clay and quartz powder.

10. A method for preparing a PVC supercritical foamed board according to any one of claims 1 to 9, characterized in that: The method comprises at least the following steps: stirring and premixing PVC resin powder, filler, modifier and stabilizer to obtain a premix; adding a foaming nucleating agent, a foaming regulator, a crosslinking agent and a lubricant to the premix and stirring and mixing to obtain a mixture; adding the mixture to a PVC supercritical foaming board extruder and extruding and foaming to obtain the mixture.

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