PVC modified efficient foaming regulator

Abstract

The invention discloses a PVC modified efficient foaming regulator, and relates to the technical field of foaming regulators, and the PVC modified efficient foaming regulator comprises the following steps: S1, preparing materials: different models of existing foaming regulators, composite SiO, glycerol monostearate and 4A zeolite; s2, mixing preparation; s3, physical cross-linking treatment: uniformly treating the mixed material, enabling the diameter of the crushed particles to be less than 0.06 mm, and performing physical cross-linking on the crushed raw material again until the material is uniform; and S4, bagging and packaging: bagging and packaging the treated materials. The PVC modified efficient foaming regulator can promote gelation of PVC, improve the melt strength and extensibility, improve the surface quality and mechanical strength of a product, enable the product to form fine bubbles, avoid the phenomena of bubble mixing and bubble merging, and enable the product to be small in density and good in strength. And the key point is that the cost of the PVC foaming regulator is reduced, and the cost is reduced by about 25%. After equivalent replacement, the quality is obviously higher than the mechanical characteristics of the original regulator.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming regulators, and particularly to a high-efficiency foaming regulator for PVC modification. Background Art

[0002] Polyvinyl chloride, abbreviated as PVC in English, is a polymer formed by the polymerization of vinyl chloride monomers under the action of initiators such as peroxides and azo compounds; or under the action of light and heat according to the free radical polymerization reaction mechanism. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively called vinyl chloride resins. PVC was once the most produced general-purpose plastic in the world and has a very wide range of applications. It is widely used in building materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc. In PVC foamed products, the purpose of adding ultra-high molecular weight polymers is: first, to promote the plasticization of PVC; second, to improve the melt strength of the PVC foaming material and prevent the merging of bubbles to obtain a uniformly foamed product; third, to ensure that the melt has good fluidity to obtain a product with good appearance. Since the products of different foamed product manufacturers are different, the equipment, processes, raw materials and lubrication systems used are all different. Therefore, we have developed modified high-efficiency foaming regulators with different properties to meet the different needs of users. For foaming materials, the size and uniformity of the pores are the key factors affecting the quality of the sheet. For low-foam products, the pores are small and uniform, the foamed products have good toughness, high strength and good surface quality. Considering from the aspect of reducing the density of the foamed product, only when the pores are small and uniform is there a possibility of further reducing the density. It is very difficult to further reduce the density when the pores are large and scattered. The following problems exist in the prior art: 1. In the existing high-efficiency foaming regulator for PVC modification, there is a slip point in the bonding of the molecular chains in the PVC foamed product, which results in the inability to fully exert the performance of the existing foaming regulator to the extreme. That is, in the existing processing technology, it is impossible to achieve a lower cost. The high price of ordinary PVC foaming regulators also leads to the inability to reduce the costs of downstream enterprises. Summary of the Invention

[0003] In order to solve the above technical problems, the technical solution adopted by the present invention is: A high-efficiency foaming regulator for PVC modification, comprising the following steps: S1. Prepare materials: a foaming regulator with a methyl methacrylate content greater than 90%, composite SiO2, monoglyceryl stearate, 4A zeolite; S2. Mix and prepare: Premix the prepared foaming regulator, composite SiO2, monoglyceryl stearate, and 4A zeolite in a certain proportion, and the proportion is 6.5:3:1:0.5; S3. Physical cross-linking treatment: Then, the mixed materials are evenly processed. After pulverization, the diameter of the particles is less than 0.06 mm. Then, the pulverized raw materials are mixed again to achieve uniform grafting treatment of the materials. S4. Bag filling and encapsulation: The processed materials are bag filled and encapsulated.

[0004] A further improvement of the technical solution of the present invention lies in: In S2, the monomer composition is added after stirring and mixing, and the temperature is raised to 35 °C. When the emulsion temperature is constant at 35 °C, an emulsifier, acrylate, methyl methacrylate, methacrylate, and molecular weight regulator are added to the stirred deionized water. Nitrogen is introduced, an initiator is added, and stirring reaction is continued. The emulsion reaction time is controlled within the range of 10 - 15 h, the temperature is raised to 72 °C for curing, the curing time is 1.5 h, and then it is cooled down to obtain a copolymer emulsion.

[0005] A further improvement of the technical solution of the present invention lies in: The initiator added during copolymerization is selected from persulfates and azo compounds, which form a redox system with sulfites, bisulfites, and thiosulfates, and the dosage accounts for 1% of the total weight of the emulsion.

[0006] A further improvement of the technical solution of the present invention lies in: In S3, the obtained copolymer emulsion is demulsified, washed, and dried, then added to a crusher, and the raw materials are crushed into granular form by the crusher. Then, the granular raw materials are added to a pulverizer to be ground into powder, and then the powder is screened through a sieve. After passing the screening, it is temporarily stored for standby.

[0007] A further improvement of the technical solution of the present invention lies in: Taking a part of the raw material powder, adding PE wax and additives to the raw material powder, mixing them and pouring them into an extruder, melting them at high temperature and pulling them into thick filaments, cooling and shaping them through cooling water, and using a cutting machine to cut them into granular form to obtain PVC particles.

[0008] A further improvement of the technical solution of the present invention lies in: Adding PVC resin, PE wax, raw material powder, and foaming regulator to a mixer for stirring. After stirring and mixing, screening is carried out to remove large impurities, and a qualified mixture is obtained after screening.

[0009] A further improvement of the technical solution of the present invention lies in: In S4, the obtained mixture is added to an extruder, and at the same time, PVC particles are added. The mixture in the hopper of the extruder is melted and plasticized into a fluid at high temperature, and the fluid is extruded and formed in a mold. The formed product is finally cooled and shaped to complete the preparation of the PVC foaming material.

[0010] Due to the adoption of the above technical solution, the technical progress achieved by the present invention compared with the prior art is: The present invention provides a PVC-modified high-efficiency foaming regulator. Under the action of mixing and preparation, the prepared foaming regulator, composite SiO2, monoglyceryl stearate, and 4A zeolite are premixed in a certain proportion, and the proportion is 6.5:3:1:0.5. By grafting and blending with the ordinary PVC foaming regulator, effects that cannot be truly achieved by the ordinary foaming regulator are obtained, such as finer and more uniform cell pores, improved material fluidity, and significantly enhanced rigidity of the product. Moreover, the direct production cost of the foaming regulator is reduced by 20%, and the dosage of the active ingredient of the foaming regulator is reduced by 40%. The PVC-modified high-efficiency foaming regulator can promote the gelation of PVC, improve the melt strength and extensibility, improve the surface quality and mechanical strength of the product, make the product form fine cell pores, avoid the phenomenon of cell merging and foaming, and make the product not only have a small density but also good strength. The key is to reduce the cost of the PVC foaming regulator, and the cost reduction range is about 25%. After equivalent substitution, the quality of the product is significantly higher than the mechanical properties of the original regulator, making the cell pores of the PVC foamed profiles and plates finer and more uniform, and the cost is greatly reduced.

[0011] The present invention provides a PVC-modified high-efficiency foaming regulator. Under the action of an initiator added during copolymerization, an initiator is added, and the stirring reaction is continued. The emulsion reaction time is controlled within the range of 10 - 15 h, and the temperature is raised to 72 °C for curing. The curing time is 1.5 h, and then it is cooled and the temperature is reduced. The initiation method is changed, and a redox complex initiation system is adopted. The intrinsic viscosity of the copolymer obtained by the redox complex initiation system is higher than that of the copolymer obtained by the single-initiator system. The initial free radical concentration increases with the increase of the initiator addition amount, which promotes the reaction to proceed faster, thereby increasing the reaction rate, increasing the molecular weight of the polymer, and obtaining a copolymer emulsion. The operation is simple, and an ultra-low molecular weight acrylate copolymer is prepared. It can be miscible with the PVC matrix containing a plasticizer, and can increase the melt strength of the PVC matrix without substantially reducing the fluidity of the PVC matrix, and can promote the foaming uniformity of the PVC foamed leather. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a process flow chart of the PVC-modified high-efficiency foaming regulator of the present invention. EMBODIMENTS

[0013] The following further describes the present invention in detail with reference to the embodiments: As Figure 1 shown, the present invention provides a PVC-modified high-efficiency foaming regulator, including the following steps. S1. Prepare materials: a foaming regulator with a methyl methacrylate content greater than 90%, composite SiO2, monoglyceryl stearate, and 4A zeolite; S2. Mix and prepare: The prepared foaming regulator, composite SiO2, monoglyceryl stearate, and 4A zeolite are premixed in a certain proportion, and the proportion is 6.5:3:1:0.5; S3. Physical cross-linking treatment: Then, the mixed materials are subjected to material homogenization treatment. After pulverization, the diameter of the particles is less than 0.06 mm. Then, the pulverized raw materials are mixed again to achieve uniform grafting treatment of the materials. S4. Bag filling and encapsulation: The treated materials are subjected to bag filling and encapsulation.

[0014] In this embodiment, by grafting and blending the ordinary PVC foaming regulator, effects that cannot be truly achieved by the ordinary foaming regulator are obtained, such as finer and more uniform cell structure, improved material fluidity, and significantly enhanced rigidity of the product. In addition, the direct production cost of the foaming regulator is reduced by 20%, the dosage of the active ingredient of the foaming regulator is reduced by 40%, and the PVC modified high-efficiency foaming regulator can promote the gelation of PVC, improve the melt strength and extensibility, improve the surface quality and mechanical strength of the product, form fine cell structures in the product, avoid the phenomenon of cell coalescence and merging, and make the product not only have a small density but also good strength. The key is to reduce the cost of the PVC foaming regulator, with the cost reduction rate being about 25%. After equivalent substitution, the quality of the product is significantly higher than the mechanical properties of the original regulator, making the cell structures of the PVC foaming profiles and sheets finer and more uniform, and the cost is greatly reduced.

[0015] such as Figure 1As shown in the figure, the present invention provides a technical solution: Preferably, in S2, stir and mix, then slowly add the monomer composition, and raise the temperature to 35°C. When the emulsion temperature is constant at 35°C, add an emulsifier, acrylate, methyl methacrylate, methacrylate, and molecular weight regulator to the stirred deionized water, introduce nitrogen, add an initiator, and continue the stirring reaction. Control the emulsion reaction time within the range of 10 - 15 h, raise the temperature to 72°C for curing, and the curing time is 1.5 h. Then cool down to obtain a copolymer emulsion. The initiator added during copolymerization is selected from persulfates and azo compounds, and forms a redox system with sulfites, bisulfites, and thiosulfates, and the dosage accounts for 1% of the total weight of the emulsion. In S3, the obtained copolymer emulsion is demulsified, washed, and dried, then added to a crusher, and the raw materials are crushed into granular form by the crusher. Then the granular raw materials are added to a grinding machine to be ground into powder, and then the powder is sieved through a sieve. After passing the sieve, it is temporarily stored for standby. Take a part of the raw material powder, add PE wax and additives to the raw material powder, mix them and pour them into an extruder, melt and draw them into thick filaments at high temperature, and cool and form them through cooling water. Use a cutting machine to cut them into granular form to obtain PVC particles. Add PVC resin, PE wax, raw material powder, and foaming regulator to a mixer for stirring. After stirring and mixing, sieve to remove large impurities, and obtain qualified mixed materials after sieving. In S4, add the obtained mixed materials to an extruder, and at the same time add PVC particles. The mixed materials in the hopper of the extruder are melted and plasticized into a fluid at high temperature, and the fluid is extruded and formed in a die. The formed product is finally shaped after cooling to complete the preparation of the PVC foaming material.

[0016] In this example, by changing the initiation method and adopting a redox complex initiation system, the intrinsic viscosity of the obtained copolymer is higher than that of the copolymer obtained by a single initiation system. The initial free radical concentration increases with the increase of the initiator addition amount, which promotes the reaction to proceed faster, thereby increasing the reaction rate and increasing the molecular weight of the polymer to obtain a copolymer emulsion. The operation is simple, and an ultra-low molecular weight acrylate copolymer is prepared. It can be miscible with a PVC matrix containing a plasticizer, and without significantly reducing the fluidity of the PVC matrix, it can increase the melt strength of the PVC matrix and promote the foaming uniformity of the PVC foaming leather.

[0017] Next, specifically describe the working principle of this PVC modified high-efficiency foaming regulator.

[0018] As Figure 1As shown, a foaming regulator with a methyl methacrylate content greater than 90%, composite SiO2, monoglyceryl stearate, and 4A zeolite. Prepare the foaming regulator, composite SiO2, monoglyceryl stearate, and 4A zeolite for premixing in a certain ratio, with the ratio being 6.5:3:1:0.5. Stir and mix, then slowly add the monomer composition. Heat up to 35°C. When the emulsion temperature is constant at 35°C, add an emulsifier, acrylate, methyl methacrylate, methacrylate, and a molecular weight regulator to the stirred deionized water. Introduce nitrogen, add an initiator, and continue stirring and reacting. Change the initiation method and adopt a redox complex initiation system. The intrinsic viscosity of the copolymer obtained is higher than that of the copolymer obtained by a single initiation system. The initial free radical concentration increases with the increase in the initiator addition amount, promoting the reaction to proceed faster, thereby increasing the reaction rate, increasing the polymer molecular weight, and obtaining a copolymer emulsion. The operation is simple. The ultra-low molecular weight acrylate copolymer prepared can be miscible with the PVC matrix containing a plasticizer. Without basically reducing the fluidity of the PVC matrix, it increases the melt strength of the PVC matrix, can promote the foaming uniformity of the PVC foamed leather, control the emulsion reaction time within the range of 10 - 15 h, heat up to 72°C for curing, with the curing time being 1.5 h, and then cool down to obtain a copolymer emulsion. The initiator added during copolymerization is selected from persulfates and azo compounds, forming a redox system with sulfites, bisulfites, and thiosulfates, with the dosage accounting for 1% of the total weight of the emulsion. By grafting and blending with a common PVC foaming regulator, effects that cannot be truly achieved by the common foaming regulator can be achieved, such as improving the fineness and uniformity of the cell structure, enhancing the fluidity of the material and the rigidity of the product significantly, and reducing the direct production cost of the foaming regulator by 20%, reducing the dosage of the active ingredient of the foaming regulator by 40%. The PVC modified high-efficiency foaming regulator can promote the gelation of PVC, improve the melt strength and extensibility, improve the surface quality and mechanical strength of the product, make the product form fine cell structures, avoid the phenomenon of cell coalescence and bubble merging, making the product not only have a small density but also good strength. The key is to reduce the cost of the PVC foaming regulator, with the cost reduction range being about 25%.After equivalent substitution, the quality of the product is significantly higher than the mechanical properties of the original regulator, making the cell pores of PVC foamed profiles and sheets finer and more uniform, and the cost is greatly reduced. Then, the mixed materials are subjected to material homogenization treatment. After pulverization, the diameter of the particles is less than 0.06 mm. Then, the pulverized raw materials are mixed again to achieve material uniformity. The obtained copolymer emulsion is demulsified, washed, and dried, and then added to a crusher. The raw materials are crushed into granular form by the crusher. Then, the granular raw materials are added to a grinding mill to be ground into powder. Then, the powder is screened through a sieve. After passing the screening, it is temporarily stored for later use. Take a part of the raw material powder, add PE wax and additives to the raw material powder, mix them and pour them into an extruder. After high-temperature melting, it is drawn into thick filaments and cooled and formed through cooling water. It is cut into granular form using a cutting machine to obtain PVC particles. Add PVC resin, PE wax, raw material powder, and foaming regulator to a mixer for stirring. After stirring and mixing, it is screened to remove large impurities. After screening, qualified mixed materials are obtained. The processed materials are bagged and packaged. S4 Add the obtained mixed materials to an extruder, and at the same time add PVC particles. The mixed materials in the hopper of the extruder are melted and plasticized into a fluid at high temperature. The fluid is transported into a mold and extruded into shape. The formed product is finally cooled and shaped to complete the preparation of PVC foamed materials.

[0019] The above has generally described the present invention in detail. However, based on the present invention, some modifications or improvements can be made, which are obvious to those of ordinary skill in the technical field. Therefore, modifications or improvements made without departing from the spirit and idea of the present invention are within the protection scope of the present invention.

Claims

1. A high-efficiency foaming regulator for PVC modification, comprising the following steps, characterized in that: S1. Prepare materials: a foaming regulator with a methyl methacrylate content greater than 90%, composite SiO2, monoglyceryl stearate, 4A zeolite; S2. Mix and prepare: premix the prepared foaming regulator, composite SiO2, monoglyceryl stearate, and 4A zeolite in a certain proportion, and the proportion is 6.5:3:1:0.5; S3. Physical cross-linking treatment: then evenly process the mixed materials, and the diameter of the particles after pulverization is less than 0.06 mm, and then remix the pulverized raw materials to achieve uniform grafting treatment of the materials; S4. Packing and encapsulation: pack and encapsulate the treated materials.

2. The PVC modified high-efficiency foaming regulator according to claim 1, characterized in that: S2. Stir and mix, then slowly add the monomer composition, heat up to 35 °C. When the emulsion temperature is constant at 35 °C, add an emulsifier, acrylate, methyl methacrylate, methacrylate, and a molecular weight regulator to the stirred deionized water, and continue to stir and react. Control the reaction time of the materials within the range of 10 - 15 h, heat up to 72 °C for curing, and the curing time is 1.5 h, and then cool down to obtain a physically cross-linked and grafted blend finished material.

3. The PVC modified high-efficiency foaming regulator according to claim 2, wherein: During grafting and blending, the raw materials are added in sequence, and physical cross-linking occurs during the heating and constant temperature process to form a raw material system with a larger molecular weight and faster plasticization.

4. The PVC modified high-efficiency foaming regulator according to claim 1, wherein: S3. Physically cross-link and graft-blend the obtained polymer material, conduct drying treatment, add it to a crusher, crush the raw materials into granular form by the crusher, then add the granular raw materials to a grinding machine to grind them into powder, and then screen the powder through a screening machine. After passing the screening, it is temporarily stored for use.

5. The PVC modified high-efficiency foaming regulator according to claim 4, wherein: Take a part of the raw material powder, add PE wax and additives to the raw material powder, mix them and pour them into an extruder, melt and draw them into thick filaments at high temperature, cool and form them through cooling water, and use a cutting machine to cut them into granular form to obtain PVC particles.

6. The PVC modified high-efficiency foaming regulator according to claim 5, characterized in that: Add PVC resin, PE wax, raw material powder, and foaming regulator to a mixer for stirring. After stirring and mixing, conduct screening to remove large impurities, and obtain a qualified mixture after screening.

7. The PVC modified high-efficiency foaming regulator according to claim 1, characterized in that: S4. Add the obtained mixture to an extruder, and at the same time add PVC particles. The mixture in the hopper of the extruder is melted and plasticized into a fluid at high temperature, and the fluid is extruded and formed in a die. The formed product is finally cooled and shaped to complete the preparation of the PVC foaming material.

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