A PVC composite material, preparation method and application

Abstract

The present invention belongs to the field of polymer material molding and processing, and discloses a PVC composite material, a preparation method and an application. The PVC composite material comprises the following components: polyvinyl chloride resin, mica powder, a toughening agent, a compatibilizer, a lubricant, a weathering agent and a stabilizer. The present invention solves the problem of poor weathering resistance after the toughness of PVC / MBS in the prior art is improved, and at the same time improves the brightness of the outer wall; it caters to the market demand for aesthetics and performance.

Description

Technical Field

[0001] The invention belongs to the field of polymer material molding and processing, and more specifically, relates to a PVC composite material and a preparation method and application thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a polymer compound formed by the polymerization of vinyl chloride monomers. It is one of the most widely used general-purpose plastics. Due to its excellent chemical stability, acid and alkali resistance, and excellent corrosion resistance, it has been widely used in the fields of industry, agriculture, municipal engineering, building water supply and drainage, etc. However, PVC also has many shortcomings, such as its relatively large brittleness, poor thermal stability, easy thermal degradation during processing, and poor processing fluidity. These shortcomings have greatly limited the promotion and use of PVC materials.

[0003] Therefore, the polyvinyl chloride products currently on the market are all modified. Generally, toughening agents, plasticizers, heat stabilizers, etc. are added to the PVC resin to improve other properties. For example, a Chinese patent (CN108219326A) discloses a high-impact PVC pipe formula and a preparation method thereof. However, the disadvantages of the PVC resin + MBS + calcium carbonate system are also quite obvious, especially in Northeast my country, where the temperature is below zero degrees Celsius all year round. On the one hand, although MBS improves the low-temperature toughness of the PVC resin, the weather resistance of the system will decrease after the MBS resin is added. On the other hand, calcium carbonate will separate from the PVC resin at low temperatures, resulting in calcium carbonate shedding, leading to defects such as decreased performance.

[0004] At present, in the field of PVC electrical conduits, the GY3050-1998 standard is implemented. Due to the rapid development of equipment and the increase in production capacity, the current mainstream equipment structure is composed of a set of conical twin-screw systems and a 1-to-4-cavity mold. After the material is extruded by the high-speed screw, it is distributed into 4-cavity molds and cooled and formed separately; after the screw extrudes the melt at high speed and merges into the mold cavity and then extrude the mold, the demoulding property will be weakened due to friction, resulting in insufficient smoothness of the outer wall. After debugging the high demoulding formula, the brightness of the outer wall will improve, but the plasticizing ability of the melt and the toughness of the product will decrease at the same time. At present, the problem of appearance smoothness and toughness can only be solved by reducing a certain screw extrusion speed.

[0005] Therefore, it is urgent to propose a new PVC material formula so that PVC-U electrical conduits can be produced at high speed with excellent appearance and performance. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and to propose a PVC composite material, preparation method and application. The present invention solves the problem of poor weather resistance after the toughness of the prior art PVC / MBS is improved, while improving the brightness of the outer wall, meeting the market demand for aesthetics and performance.

[0007] In order to achieve the above object, the first aspect of the present invention provides a PVC composite material, which comprises the following components: polyvinyl chloride resin, mica powder, toughening agent, compatibilizer, lubricant, weathering agent and stabilizer.

[0008] According to the present invention, preferably, the PVC composition material comprises the following components in parts by weight: 90-110 parts of polyvinyl chloride resin, 3-25 parts of mica powder, 1-12 parts of toughening agent, 0.3-2.0 parts of compatibilizer, 0.1-1.2 parts of lubricant, 2.5-5 parts of weathering agent and 3.5-5 parts of stabilizer.

[0009] According to the present invention, preferably, the PVC material composition comprises the following components in parts by weight: 90-110 parts of polyvinyl chloride resin, 10-25 parts of mica powder, 1-12 parts of toughening agent, 0.3-2.0 parts of compatibilizer, 0.1-1.2 parts of lubricant, 2.5-5 parts of weathering agent and 3.5-5 parts of stabilizer.

[0010] According to the present invention, preferably, the polyvinyl chloride resin is a mixture of PVC-5 type and PVC-8 type.

[0011] According to the present invention, preferably, the mass ratio of the PVC-5 type to the PVC-8 type is (50-80):(30-50).

[0012] According to the present invention, preferably, the viscosity of the PVC-5 type is 118-110 ml / g, and the average degree of polymerization is 900-1100.

[0013] In the present invention, the PVC-5 type is used as the base material of the PVC composite material, has the effect of flame retardancy and insulation, and has a certain Shore hardness and high Vicat property.

[0014] According to the present invention, preferably, the viscosity of the PVC-8 type is 80-70 ml / g, and the average degree of polymerization is 650-750.

[0015] In the present invention, the PVC-8 type can reduce the viscosity between materials to improve the demoulding ability of the product and achieve an effect beneficial to the extrusion process.

[0016] The PVC resin powder of different polymerization degrees can be interlaced with other blends to obtain a better melt shell structure, further improve the processability and demoulding effect, promote the toughness effect under high-speed extrusion production, and achieve the purpose of smooth outer wall.

[0017] According to the present invention, preferably, the mica powder is wet-process mica powder, with a mica content of more than 90% and a fineness of 1500-2000 mesh.

[0018] According to the present invention, preferably, the toughening agent is a blended resin system of ABS / MBS / ACR.

[0019] According to the present invention, preferably, the mass ratio of ABS resin, MBS resin and ACR resin is (1-2.5):(1-5):(2-4).

[0020] According to the present invention, preferably, the compatibilizer is at least one of zinc stearate, calcium stearate and stearic acid.

[0021] According to the present invention, preferably, the lubricant is at least one of high melting point polyethylene wax, oxidized polyethylene wax and Fischer-Tropsch wax.

[0022] According to the present invention, preferably, the weathering agent is a mixture of rutile titanium dioxide and a fluorescent whitening agent, and the mass ratio of the rutile titanium dioxide to the fluorescent whitening agent is (900-1100): (8-12).

[0023] In the present invention, the weathering agent can also solve the problem of insufficient whiteness of mica powder.

[0024] According to the present invention, preferably, the stabilizer is a composite calcium zinc stabilizer and / or an organic tin stabilizer for PVC.

[0025] According to the present invention, preferably, the PVC composition material further comprises 0.02-0.05 parts of an antioxidant.

[0026] The second aspect of the present invention provides a method for preparing the PVC composition material, which comprises: blending the polyvinyl chloride resin, mica powder, toughening agent, compatibilizer, lubricant, weathering agent and stabilizer until uniform to obtain a premix and extruding the premix to obtain the PVC composition material.

[0027] The third aspect of the present invention provides the use of the PVC composition material as a PVC-U electrical casing material.

[0028] The beneficial effects of the technical solution of the present invention are as follows: the present invention solves the problem of poor weather resistance after the toughness of the prior art PVC / MBS is improved, and at the same time improves the brightness of the outer wall; it caters to the market demand for aesthetics and performance, specifically:

[0029] 1. Adding MBS and ABS toughening agents to the PVC system can improve the low-temperature toughness of PVC resin, especially in low-temperature environments. However, after being placed for a long time, the toughness is greatly reduced, which is manifested as poor weather resistance. The applicant found that if mica powder is added to the system, the weather resistance and compression resistance will be improved. This is because the elasticity and toughness of mica powder are higher than those of polyolefins. It is interspersed in the mesh structure formed by PVC and is not easy to shrink and fall off in low-temperature environments. It can support the mesh structure formed by PVC / MBS / MBS / ACR to improve weather resistance and at the same time improve the toughness effect under complex ambient temperatures.

[0030] 2. On the other hand, the mica powder added in the present invention can replace calcium carbonate to prevent the structural shrinkage of the product under low temperature conditions from causing the PVC / calcium carbonate particles to fall off, resulting in a decrease in the performance of the PVC resin. This may be because the mica powder can replace calcium carbonate to play its role, and through sufficient ACR and compatibilizer, the mica powder has good compatibility, making it have an outer wall finish comparable to glass, and can also solve the weather resistance problem of MBS / ABS and make up for the lack of its own poor impact toughness. Under certain optimized matching, the blend can also maintain a certain impact toughness under high-speed extrusion production.

[0031] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0033] In the following embodiments and comparative examples:

[0034] The viscosity of the PVC-5 type is 118-110 ml / g, and the average degree of polymerization is 1000;

[0035] The viscosity of the PVC-8 type is 80-70 ml / g, and the average degree of polymerization is 700;

[0036] The mica powder is wet-process mica powder, with a mica content of more than 90% and a fineness of 2000 mesh;

[0037] The compatibilizer is stearic acid;

[0038] The lubricant is high melting point polyethylene wax;

[0039] The weathering agent is a mixture of rutile titanium dioxide and a fluorescent whitening agent, and the mass ratio of the rutile titanium dioxide to the whitening agent is 1kg:10g;

[0040] The stabilizer is an organic tin stabilizer.

[0041] Example 1

[0042] This embodiment provides a PVC composite material. The components and usage of the PVC composite material are shown in Table 1.

[0043] The PVC composition material of this embodiment is used as a PVC-U electrical conduit material with an outer diameter of dn20mm. The preparation method of the PVC-U electrical conduit material comprises: blending the components included in the PVC composition material of this embodiment in proportion until uniform, obtaining a premix, and extruding and molding the premix to obtain the PVC-U electrical conduit material with an outer diameter of dn20mm, wherein the extrusion speed is 80m / min for producing the electrical conduit.

[0044] Comparative Examples 1-3 also use the corresponding PVC composition materials as PVC-U electrical conduit materials with a dn of 20 mm, but the extrusion speed of the PVC-U electrical conduit materials with an outer diameter of 20 mm in Comparative Examples 1-3 is 60 m / min. It can be seen that the PVC composition material of the present invention can maintain a certain impact toughness and have a certain outer wall brightness under high-speed extrusion of 80 m / min.

[0045] Table 1

[0046]

[0047] Test Case

[0048] This test example tests the PVC-U electrical conduits prepared from the PVC composition materials of the above embodiments and comparative examples. The test method is the standard requirements of "JG 3050-1998 Insulating electrical conduits and accessories for construction":

[0049] Impact: It complies with the 6.5 bushing impact resistance test method in the standard "JG 3050-1998 Insulated Electrical Bushings and Accessories for Buildings".

[0050] Bending: It complies with the 6.6 bushing bending performance determination method in the standard requirements of "JG 3050-1998 Insulating Electrical Bushings and Accessories for Buildings".

[0051] Drop: It complies with the drop performance test method of 6.8 bushings and accessories in the standard requirements of "JG 3050-1998 Insulating Electrical Bushings and Accessories for Buildings".

[0052] The results are shown in Table 2.

[0053] Table 2

[0054] Shock bending fall Example 1 10 / 12 Passed 2 / 3 passed 2 / 3 passed Example 2 10 / 12 Passed 3 / 3 passed 2 / 3 passed Example 3 11 / 12 passed 3 / 3 passed 2 / 3 passed Example 4 11 / 12 passed 3 / 3 passed 3 / 3 passed Example 5 12 / 12 passed 3 / 3 passed 3 / 3 passed Example 6 12 / 12 passed 3 / 3 passed 3 / 3 passed Example 7 12 / 12 passed 3 / 3 passed 3 / 3 passed Example 8 11 / 12 passed 3 / 3 passed 3 / 3 passed Example 9 11 / 12 passed 3 / 3 passed 3 / 3 passed Example 10 11 / 12 passed 3 / 3 passed 3 / 3 passed Comparative Example 1 7 / 12 passed 2 / 3 passed 1 / 3 passed Comparative Example 2 3 / 12 Passed 1 / 3 passed 0 / 3 passed Comparative Example 3 9 / 12 passed 3 / 3 passed 1 / 3 passed

[0055] As shown in Table 2, when the PVC-U electrical conduits prepared from the PVC composition material of the present invention were subjected to the above tests, all 12 tubes passed the impact performance test, all 3 tubes passed the bending performance test, and all 3 tubes passed the drop performance test. The PVC-U electrical conduits with high brightness and high toughness were prepared from the PVC composition material of the present invention at a high screw extrusion speed.

[0056] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A PVC composite material, characterized in that: The PVC composite material comprises the following components in parts by weight: 90-110 parts of polyvinyl chloride resin, 3-25 parts of mica powder, 1-12 parts of toughening agent, 0.3-2.0 parts of compatibilizer, 0.1-1.2 parts of lubricant, 2.5-5 parts of weathering agent and 3.5-5 parts of stabilizer; The mica powder is wet-process mica powder, with a mica content of more than 90% and a fineness of 1500-2000 mesh; The polyvinyl chloride resin is a mixture of PVC-5 and PVC-8; The viscosity of the PVC-5 type is 118-110 ml / g, and the average degree of polymerization is 900-1100; The viscosity of the PVC-8 type is 80-70 ml / g, and the average degree of polymerization is 650-750; The toughening agent is a blended resin system of ABS / MBS / ACR; the mass ratio of ABS resin, MBS resin and ACR resin is (1-2.5): (3-5): (2-4).

2. The PVC composition material according to claim 1, wherein: The PVC material composition comprises the following components in parts by weight: 90-110 parts of polyvinyl chloride resin, 10-25 parts of mica powder, 1-12 parts of toughening agent, 0.3-2.0 parts of compatibilizer, 0.1-1.2 parts of lubricant, 2.5-5 parts of weathering agent and 3.5-5 parts of stabilizer.

3. The PVC composition material according to claim 1, wherein: The compatibilizer is at least one of zinc stearate, calcium stearate and stearic acid; The lubricant is at least one of high melting point polyethylene wax, oxidized polyethylene wax and Fischer-Tropsch wax; The weathering agent is a mixture of rutile titanium dioxide and a fluorescent whitening agent, and the mass ratio of the rutile titanium dioxide and the whitening agent is (900-1100): (8-12); The stabilizer is a composite calcium zinc stabilizer and / or an organic tin stabilizer for PVC.

4. The PVC composition material according to claim 3, wherein: The mass ratio of the PVC-5 type to the PVC-8 type is (50-80): (30-50).

5. The PVC composition material according to claim 1, wherein: The PVC composition material also includes 0.02-0.05 parts of antioxidant.

6. The method for preparing the PVC composition material according to any one of claims 1 to 5, characterized in that: The preparation method comprises: blending the polyvinyl chloride resin, mica powder, toughening agent, compatibilizer, lubricant, weathering agent and stabilizer until uniform to obtain a premix and extruding and molding the premix to obtain the PVC composite material.

7. Use of the PVC composition material according to any one of claims 1 to 5 as a PVC-U electrical casing material.

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