A kind of PVC with high toughness and high stability and preparation method thereof

Abstract

The present invention relates to a high-toughness, high-stability PVC and a preparation method thereof, and belongs to the technical field of modified plastics. The high-toughness, high-stability PVC of the present invention comprises the following components by weight: 100 parts of PVC, 2.75-5.25 parts of stabilizer, 15-25 parts of toughening agent, 1-20 parts of filler, 0.3-0.8 parts of antioxidant and 1-5 parts of lubricant; the stabilizer comprises maleic acid organotin and dipentaerythritol. The present invention solves the low-temperature toughness problem of PVC materials by limiting the content of stabilizers and toughening agents; at the same time, maleic acid organotin and dipentaerythritol are selected as stabilizers, and the thermal stability and low-temperature toughness of PVC materials are synergistically improved by compounding maleic acid organotin and dipentaerythritol, so that the application range of PVC materials is wider.

Description

Technical Field

[0001] The invention belongs to the technical field of modified plastics, and in particular relates to PVC with high toughness and high stability and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) materials have the advantages of flame retardancy, acid and alkali resistance, and diversified processing methods. They have a wide range of modification and can be optimized in many aspects according to actual needs. Therefore, they can be widely used in home appliances, electronics, security, automobiles and other fields. Pure PVC resin has poor stability and low decomposition temperature. It must be modified to improve its thermal stability before it can be used, especially when it needs to be exposed to high temperature environments, the thermal stability of the material needs to be guaranteed. The main reason for the poor thermal stability of PVC is that the resin contains a large number of unstable structures, allyl chloride, free chloride ions, and unsaturated bonds, which are easily destroyed and decomposed to produce hydrogen chloride. The presence of hydrogen chloride further accelerates the decomposition of polyvinyl chloride, resulting in material failure. At the same time, PVC materials have the characteristics of brittleness and relatively low strength, and are prone to problems such as deformation, damage, and brittle cracking during transportation and installation. Hard PVC plastics have poor toughness and low impact strength at room temperature, and even worse toughness at low temperatures. They quickly harden and become brittle when the temperature is lowered, and are very easy to crack when impacted, which limits the application of PVC materials in low temperature environments.

[0003] The inventor of the present invention previously applied for CN114685911A, which disclosed a thermally stable PVC. The composite heat stabilizer composed of thiol organotin and maleic acid organotin synergistically with other components significantly improved the thermal stability and fluidity of PVC. It has excellent thermal stability and good fluidity, and the melt flow rate can reach more than 57g / 10min. It can meet the thermal stability and fluidity requirements of PVC materials in the fields of automobile manufacturing and electronic appliances, and can be widely used in the fields of automobile manufacturing and electronic appliances. However, the invention failed to solve the problem of poor low-temperature toughness of PVC. The low-temperature impact strength of the thermally stable PVC prepared by it is only 5-8KJ / m 2 . Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-toughness, high-stability PVC and a preparation method thereof, so as to solve the problem that the PVC material in the prior art is difficult to have both high thermal stability and low-temperature toughness, thereby making the application of PVC material more extensive.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: a high-toughness and high-stability PVC, comprising the following components by weight: 100 parts of PVC, 2.75-5.25 parts of stabilizer, 15-25 parts of toughening agent, 1-20 parts of filler, 0.3-0.8 parts of antioxidant and 1-5 parts of lubricant; the stabilizer comprises maleic acid organotin and dipentaerythritol.

[0006] PVC is a polar non-crystalline polymer with poor thermal stability, difficult to process, and cannot be used directly. It must be modified before it can be used. Due to the different types and contents of the added related additives and fillers, the performance and requirements of the prepared PVC materials are different. In the prior art, the thermal stability and toughness of PVC materials have been studied, but there are few reports of PVC materials that have both thermal stability and low-temperature toughness. The present invention provides a PVC material that is stable in high temperature environments and has high toughness in low temperature environments by optimizing the content of stabilizers and tougheners and optimizing the types of stabilizers, thereby increasing the application range of PVC materials. The inventors of the present application have found through a large number of experimental studies that maleic acid organotin reacts with unstable chlorine atoms in PVC to limit the initiation of de-HCl and prevent the formation of large conjugated structures. At the same time, the addition of conjugated double bonds, maleic acid tin, easily reacts with the conjugated double bonds in the PVC molecules to undergo a "diene addition" reaction, so that the conjugated double bonds are fixed and the growth of the conjugated chains is inhibited; and the high content of hydroxyl groups in dipentaerythritol can react with HCL, which has an efficient acid absorption effect. The initial and long-term stability of PVC can be improved by compounding maleic acid organotin and dipentaerythritol, so that the linear structure of polyvinyl chloride can always remain stable and be better compatible with the toughening agent, thereby improving the low-temperature toughness of the material.

[0007] As a preferred embodiment of the high-toughness, high-stability PVC of the present invention, the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is dipentaerythritol: maleic acid organotin = 1:2-16. Studies have shown that when the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is selected in the above-mentioned range, the thermal stability and low-temperature toughness of the prepared PVC material are greatly improved. Preferably, the stabilizer includes 2.5-4 parts of maleic acid organotin and 0.25-1.25 parts of dipentaerythritol.

[0008] As a preferred embodiment of the high-toughness, high-stability PVC of the present invention, the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is dipentaerythritol: maleic acid organotin = 1: 3 to 10. Studies have shown that when the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is selected within the above range, the high temperature stability and low temperature impact resistance of the prepared PVC material are higher.

[0009] As a preferred embodiment of the high-toughness and high-stability PVC of the present invention, the K value of the PVC is 49-63. The inventors of the present application have found that the K value of PVC reflects the viscosity of the resin, which directly affects the plasticizing ability of the material and is closely related to the toughness and stability of the material.

[0010] As a preferred embodiment of the high-toughness and high-stability PVC of the present invention, the toughening agent is at least one of MBS, chlorinated polyethylene, and acrylate.

[0011] As a preferred embodiment of the high-toughness and high-stability PVC of the present invention, the filler is at least one of calcium carbonate and talc.

[0012] As a preferred embodiment of the high-toughness, high-stability PVC of the present invention, the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0013] As a preferred embodiment of the high-toughness and high-stability PVC of the present invention, the lubricant is at least one of polyethylene wax, EBS, and fatty acid ester.

[0014] The present invention also provides a method for preparing the high-toughness, high-stability PVC, comprising the following steps:

[0015] (1) Weighing PVC resin, heat stabilizer, toughening agent, lubricant and antioxidant and mixing them at a low speed to obtain a mixed material A;

[0016] (2) Mixing the filler and mixed material A at high speed, heating to 80° C. and placing in a cold tank to obtain mixed material B;

[0017] (3) The mixed material B is extruded and granulated by a two-stage extruder to obtain high-toughness and high-stability PVC.

[0018] Preferably, the mixing speed in step (1) is 20-40 r / s; and the mixing speed in step (2) is 50-80 r / s.

[0019] The invention also provides application of the high-toughness and high-stability PVC in the fields of electronic manufacturing and automobile manufacturing.

[0020] Compared with the prior art, the invention has the following beneficial effects: the invention provides a PVC with high toughness and high stability, and solves the problem of low-temperature toughness of PVC materials by limiting the contents of stabilizers and toughening agents; at the same time, maleic acid organotin and dipentaerythritol are selected as stabilizers, and the thermal stability and low-temperature toughness of PVC materials are synergistically improved by compounding maleic acid organotin and dipentaerythritol, so that the application range of PVC materials is wider. DETAILED DESCRIPTION

[0021] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0022] The raw materials used in the embodiments and comparative examples of the present invention are described as follows, but are not limited to these materials:

[0023] PVC resin A: PVC S-58, Formosa Plastics Industry (Ningbo) Co., Ltd., K value 55-59;

[0024] PVC resin B: PVC S-400, KANEKA CORPORATION, K value 49-53;

[0025] PVC resin C: PVC TL-800, LG Chemical Co., Ltd., K value is 60-63;

[0026] PVC resin D: PVC TK-1000, Shin-Etsu Chemical Co., Ltd., K value 66-68;

[0027] PVC resin E: PVC S-70, Formosa Plastics Industry (Ningbo) Co., Ltd., K value is 71-74;

[0028] Heat stabilizer A: organotin maleate, Quzhou Jianhua Dongxu Additive Co., Ltd.;

[0029] Heat stabilizer B: dipentaerythritol, Shandong Jinshengtai Chemical Co., Ltd.;

[0030] Thermal stabilizer C: mercaptan organotin, Hubei Benxing Chemical Co., Ltd.;

[0031] Heat stabilizer D: zinc stearate heat stabilizer, RUP-110C, Aidico Investment Co., Ltd.;

[0032] Thermal stabilizer E: epoxidized soybean oil, HM-01R, Haierma Group;

[0033] Toughening agent: Chlorinated polyethylene, WEIPREN2135, Yaxing Chemical Co., Ltd.;

[0034] Filler: calcium carbonate, LX-103, Lixin Plastics Co., Ltd.;

[0035] Antioxidant: Hindered phenol antioxidant, RIANOX 1076, Li’anlong New Materials Co., Ltd.;

[0036] Lubricant: Polyethylene wax, Licowax PE 520 powder, Clariant Corporation.

[0037] In the embodiments and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified; and the components used are consistent unless otherwise specified in the embodiments and comparative examples.

[0038] Examples 1 to 10, Comparative Examples 1 to 10

[0039] The components of the PVC materials of Examples 1 to 10 of the present invention are shown in Table 1 below.

[0040] The components of the PVC materials of Comparative Examples 1 to 10 of the present invention are shown in Table 2 below.

[0041] The preparation method of the PVC materials of Examples 1 to 10 and Comparative Examples 1 to 10 of the present invention is as follows: weigh the components of PVC resin, stabilizer, toughening agent, lubricant and antioxidant in proportion, place them in a high-speed mixer for low-speed mixing, then add filler for high-speed mixing, and when the material temperature reaches 80° C., discharge the material into a cooling cylinder to obtain a mixture; and extrude and granulate the mixture using a two-stage extruder to obtain the PVC material.

[0042] The thermal stability and low temperature toughness of the PVC materials prepared in Examples 1 to 10 and Comparative Examples 1 to 10 were tested respectively. The test results are shown in Table 3.

[0043] Performance test methods:

[0044] (1) Thermal stability test method: The initial decomposition temperature of PVC material is used as the evaluation index. The test instrument is a NETZSCH thermogravimetric analyzer, model TG 209F1. Specific test method: In a nitrogen atmosphere, the temperature is raised from room temperature to 750°C at a rate of 20°C / min. The temperature at which the mass of PVC material decomposes by 1% is the initial decomposition temperature.

[0045] (2) Low temperature toughness test method: The cantilever beam notch impact strength is used as the evaluation index. The test standard is GB / T1843-2008. The sample is a 4 mm injection molded notch specimen. It needs to be treated in a -20°C low temperature freezer for 4 hours before testing.

[0046] Table 1 Composition components of PVC materials of Examples 1 to 10

[0047]

[0048] Table 2 Composition components of PVC materials of Comparative Examples 1 to 10

[0049]

[0050] Table 3 Performance test

[0051]

[0052]

[0053] As shown in Table 3, the selection of the type of stabilizer has a great influence on the thermal stability and low-temperature toughness of the prepared PVC material. By comparing Example 4, Comparative Examples 1 and 2, it can be seen that the thermal stabilizer maleic acid organotin and dipentaerythritol can significantly improve the initial decomposition temperature and low-temperature impact strength of the PVC material by cooperating with each other; By comparing Examples 1 to 8, Comparative Examples 7 and 8, it can be seen that when the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is dipentaerythritol: maleic acid organotin = 1:2-16, the thermal stability and low-temperature toughness of the prepared PVC material are good, and its initial decomposition temperature reaches above 240°C, and when the weight ratio of maleic acid organotin and dipentaerythritol in the stabilizer is dipentaerythritol: maleic acid organotin = 1:3-10, the thermal stability and low-temperature toughness of the prepared PVC material are better; By comparing Examples 3, 9, 10, Comparative Examples 9 and 10, it can be seen that when the K value of PVC is 49-63, the thermal stability and low-temperature toughness of the prepared PVC material are ≥13.5KJ / m 2 .

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A high-toughness, high-stability PVC, characterized in that: The invention comprises the following components in parts by weight: 100 parts of PVC, 2.75-5.25 parts of a stabilizer, 15-25 parts of a toughening agent, 1-20 parts of a filler, 0.3-0.8 parts of an antioxidant and 1-5 parts of a lubricant; the stabilizer comprises maleic acid organic tin and dipentaerythritol, and the weight ratio of maleic acid organic tin to dipentaerythritol in the stabilizer is dipentaerythritol:maleic acid organic tin=1:2-16; the K value range of the PVC is 49-63.

2. The high-toughness, high-stability PVC according to claim 1, characterized in that: The weight ratio of maleic acid organotin to dipentaerythritol in the stabilizer is dipentaerythritol: maleic acid organotin=1:3-10.

3. The high-toughness, high-stability PVC according to claim 1, characterized in that: The toughening agent is at least one of MBS, chlorinated polyethylene and acrylate.

4. The high-toughness, high-stability PVC according to claim 1, characterized in that: The filler is at least one of calcium carbonate and talc.

5. The high-toughness, high-stability PVC according to claim 1, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

6. The high-toughness, high-stability PVC according to claim 1, characterized in that: The lubricant is at least one of polyethylene wax, EBS, and fatty acid ester.

7. The method for preparing high-toughness and high-stability PVC according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Weighing PVC resin, heat stabilizer, toughening agent, lubricant and antioxidant and mixing them at a low speed to obtain a mixed material A; (2) Mixing the filler and mixed material A at high speed, heating to 80° C. and placing in a cold tank to obtain mixed material B; (3) The mixed material B is extruded and granulated by a two-stage extruder to obtain high-toughness and high-stability PVC.

8. Use of the high-toughness, high-stability PVC according to any one of claims 1 to 6 in household appliance control devices, smoke alarm devices, safety indicator lights, and wire buses.

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