A cellulose composite PVC material, its preparation method and application

Abstract

The present invention discloses a cellulose composite PVC material, its preparation method and applications, belonging to the technical field of polymer materials. By introducing partial cellulose powder into the components and compounding specific stabilizers and fillers, the cellulose composite PVC material of the present invention can not only achieve high thermal stability, have a high decomposition temperature and a low odor level, but also have a high surface resistance, making it suitable for the electrical appliance industry.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a cellulose composite PVC material, a preparation method thereof and an application thereof. Background Art

[0002] PVC materials are widely used in the electrical industry due to their excellent flame retardancy, corrosion resistance, acid and alkali resistance and other characteristics. However, PVC materials have the shortcoming of poor thermal stability. When the application environment temperature is relatively high or the processing cycle is relatively long, it is very easy to decompose and age, and the generation of odor will occur. In order to solve the problem of poor thermal stability of PVC materials, the prior art mainly dopes heat stabilizers or dispersion modifiers in the products. However, this method generally can only inhibit the decomposition and aging during the processing of PVC materials. When the environmental temperature of the product reaches the PVC decomposition critical point, decomposition will still occur; at the same time, such modification means may weaken the electrical insulation of the PVC material itself, further restricting the application range of the product. Summary of the Invention

[0003] Based on the defects existing in the prior art, the purpose of the present invention is to provide a cellulose composite PVC material. By introducing a part of cellulose powder as a component in the product and compounding specific stabilizers and fillers at the same time, the product can not only achieve high thermal stability, a relatively high decomposition temperature and a low odor level, but also has a relatively high surface resistance, and is suitable for use in the electrical industry.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A cellulose composite PVC material, comprising the following components in parts by weight:

[0006] 75-105 parts of PVC resin, 15-45 parts of cellulose powder, 3-10 parts of stabilizer, 2-12 parts of filler;

[0007] The filler is a mixture of calcium carbonate and magnesium oxide, and the mass ratio of the two is (1:1)-(8:1);

[0008] The stabilizer is zinc stearate.

[0009] Preferably, in the fiber composite PVC material, the weight parts of PVC resin are one of 75 parts, 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts or the range value of any two of them; the weight parts of cellulose powder are one of 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or the range value of any two of them; the weight parts of stabilizer are one of 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 9 parts, 10 parts or the range value of any two of them; the weight parts of filler are one of 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts or the range value of any two of them.

[0010] Preferably, in the cellulose composite PVC material, the mass content of PVC resin ≥ 50wt%.

[0011] Preferably, the cellulose composite PVC material comprises the following components in parts by weight:

[0012] 80 - 100 parts of PVC resin, 20 - 40 parts of cellulose powder, 4 - 8 parts of stabilizer, 3 - 10 parts of filler.

[0013] More preferably, the cellulose composite PVC material comprises the following components in parts by weight:

[0014] 80 - 100 parts of PVC resin, 20 - 40 parts of cellulose powder, 4 - 8 parts of stabilizer, 2 - 8 parts of calcium carbonate, 1 - 2 parts of magnesium oxide.

[0015] In the prior art, there are also some solutions that use biomass to modify PVC products. However, due to the complex composition of biomass itself without carbonization, and at the same time, some macromolecular substances contained in it are prone to deterioration after product processing, affecting the performance of the product and even emitting odors. Therefore, the addition amount of biomass in such solutions is mostly small, and it is not used as the main modification component. In the technical solution of the present invention, the inventor surprisingly found through experiments that when part of the cellulose powder of biological origin acts as a filler in the PVC product, and is combined with specific types of fillers and stabilizers, during the co-heating and processing of cellulose and PVC resin, the hydrogen chloride generated by the decomposition of PVC resin can act as an acid catalyst to promote the dehydration and decomposition of cellulose, and increase the decomposition temperature of PVC. Finally, the decomposition temperature of the overall product can be effectively increased, and the thermal stability of the product is significantly enhanced. At the same time, under the synergistic effect of the cellulose powder with specific fillers and stabilizers, no significant odor problem is caused, the odor level of the product is low, and the electrical insulation of the product is high, which is very suitable for the electrical appliance industry.

[0016] In addition, through experiments by the inventors, it was found that due to the differences in structure and composition brought about by the types of biomass, if some other biomass (such as wood powder, etc.) is used, it may not be able to effectively increase the initial decomposition temperature of the product. At the same time, based on the characteristics of biomass, it may also significantly reduce the electrical insulation of the product and increase the odor level. On the other hand, although the cellulose powder described in the present invention is used as a filler, it cannot be increased in the addition amount according to actual needs similar to conventional fillers, otherwise it may lead to a re - weakening of the thermal stability of the product and poor electrical insulation.

[0017] In the product described in the present invention, calcium carbonate and magnesium oxide in the filler have a certain acid - suppressing property under specific combinations. When combined with the stabilizer zinc stearate, it can effectively maintain that the cellulose powder in the PVC product will not produce decomposition by - products during processing and high - temperature environments, which will affect the properties of the PVC resin itself. At the same time, it can also act as an adsorbent to adsorb the odor - forming molecules generated by the decomposition of PVC itself. Therefore, if this component is replaced or deleted, the overall performance of the product will be severely weakened.

[0018] Preferably, for the mixture of calcium carbonate and magnesium oxide, the mass ratio of the two is one of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1 or the range value of any two of them.

[0019] More preferably, for the mixture of calcium carbonate and magnesium oxide, the mass ratio of the two is (3:1) to (5:1).

[0020] Verified by the inventors, when the mass ratio of the mixture of calcium carbonate and magnesium oxide is within the above - mentioned preferred range, the comprehensive performance of the product is better.

[0021] Preferably, the average particle size D50 of the calcium carbonate is 0.8 - 2 μm, and the average particle size D50 of the magnesium oxide is 13 - 18 μm.

[0022] Preferably, the average particle size D50 of the calcium carbonate is 1.3 - 1.8 μm, and the average particle size D50 of the magnesium oxide is 14 - 16 μm.

[0023] The average particle size D50 of the calcium carbonate and magnesium oxide can be directly measured by a particle size analyzer.

[0024] Preferably, the cellulose powder is at least one of ethyl cellulose ether, acetyl cellulose ether, hydroxyethyl cellulose ether, and hydroxypropyl cellulose ether.

[0025] Through experiments by the inventors, it was found that using the above - mentioned types of cellulose powder can achieve an ideal product enhancement effect.

[0026] Preferably, the purity of the cellulose powder is ≥90%, and more preferably, the purity is ≥95%.

[0027] More preferably, the purity of the cellulose powder is one of 95%, 96%, 97%, 98%, 99%, 99.9% or the range value of any two of them.

[0028] More preferably, the average particle size of the cellulose powder is 90 - 125 μm.

[0029] More preferably, the average particle size of the cellulose powder is 115 - 125 μm.

[0030] The average particle size of the cellulose powder can be directly detected by a laser diffraction particle size analyzer.

[0031] More preferably, the viscosity of the hydroxyethyl cellulose is 150 - 400 mPa·s, and the viscosity is measured by the rotational viscometer method (the solvent is analytical grade cyclohexanone), and the test temperature is 20°C.

[0032] More preferably, the viscosity of the hydroxyethyl cellulose is 250 - 350 mPa·s.

[0033] The molar substitution degree of the hydroxyethyl cellulose is 3.5 - 4.2, which is directly detected by gas chromatography.

[0034] Preferably, the degree of polymerization of the PVC resin is 500 - 800.

[0035] The degree of polymerization of the PVC resin is measured by the viscosity method, and the test conditions are: dissolving the PVC sample in an appropriate solvent (such as THF, DMF, etc.), and then measuring its viscosity at a certain temperature, and calculating the degree of polymerization through a standard curve.

[0036] More preferably, the polymer of the PVC resin is one of 500, 600, 700, 800 or the range value of any two of them.

[0037] When the polymer of the PVC resin in the product of the present invention is preferably within the above range, the performance of the product will be further improved.

[0038] Preferably, the viscosity of the PVC resin is < 95.

[0039] More preferably, the viscosity of the PVC resin is 65 - 80.

[0040] The viscosity of the PVC resin is measured by a capillary viscometer, and the test temperature is 25°C.

[0041] Preferably, the components of the cellulose composite PVC material further include 1 - 4 parts of processing aids.

[0042] Preferably, the processing aids include 0.2 - 0.6 parts of antioxidant and 1.2 - 3 parts of lubricant.

[0043] It should be noted that, on the premise of not damaging the technical effects of the products of the present invention, those skilled in the art can introduce appropriate processing aids into the products according to actual needs. Besides the antioxidants and lubricants described in the present invention, other components such as dispersants, preservatives, antistatic agents, etc. can also be introduced. The technical solution of the present invention does not exclusivley limit the processing aids.

[0044] Preferably, the antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants.

[0045] More preferably, the antioxidant is a mixture of a hindered phenol antioxidant and a phosphite antioxidant compounded in a mass ratio of (1 - 2):1.

[0046] Preferably, the lubricant is at least one of polyethylene wax and stearic acid.

[0047] It should be noted that the selection of the types of the antioxidants and lubricants in the present invention is only a preferred selection. During the actual production and use process, the cellulose composite PVC material of the present invention can select more suitable types of antioxidants and lubricants according to actual needs, and is not limited to the preferred types described in the present invention.

[0048] Preferably, the initial decomposition temperature of the cellulose composite PVC material is 240 - 250 °C, the volume resistivity is 2.8×10 13 ~3.4×10 13 Ω, and the odor level is 3 - 3.5 levels.

[0049] Another object of the present invention is to provide a preparation method of the cellulose composite PVC material, comprising the following steps:

[0050] Heat the PVC resin, stabilizer and lubricant to 75 - 85 °C and mix them evenly, then add cellulose powder and antioxidant and heat to 100 - 120 °C to mix evenly. Finally, add filler and mix, and place it into a twin-screw extruder for melt extrusion granulation to obtain the cellulose composite PVC material.

[0051] Preferably, the temperature during the melt extrusion granulation is 100 - 180 °C.

[0052] The preparation method of the cellulose composite PVC material of the present invention has simple operation steps and can realize industrial-scale production.

[0053] Another object of the present invention is to provide the application of the cellulose composite PVC material in the preparation of electrical components.

[0054] The cellulose composite PVC material described in the present invention has been tested and its initial decomposition temperature can reach up to nearly 250 °C, with extremely high thermal stability. At the same time, the odor level is relatively low, and the volume resistivity can reach up to 3.2×10 13 Ω or more, showing good electrical insulation. Therefore, it is very suitable for preparing some components required for electrical appliances (such as insulating sleeves, cable protective layers, etc.).

[0055] The beneficial effect of the present invention is that the present invention provides a cellulose composite PVC material. By introducing a part of cellulose powder as a component in the product and compounding specific stabilizers and fillers, the product can not only achieve high thermal stability, high decomposition temperature, low odor level, but also has a high volume resistivity, making it suitable for the electrical appliance industry. Detailed Embodiments

[0056] 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 examples and comparative examples. The purpose is to understand the content of the present invention in detail, rather than limiting the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. The experimental reagents and instruments involved in the implementation of the present invention are all common ordinary reagents and instruments unless otherwise specified.

[0057] Examples 1 - 12

[0058] An embodiment of the cellulose composite PVC material, its preparation method and application described in the present invention. The composition components of the cellulose composite PVC material are shown in Table 1.

[0059] Heat the PVC resin, stabilizer and lubricant to 80 °C and mix evenly. Then add the cellulose powder and antioxidant and heat to 110 °C and mix evenly. Finally, add the filler and mix and place it into a twin-screw extruder for melt extrusion granulation to obtain the cellulose composite PVC material.

[0060] When the components are melt-blended and extruded, the temperature zones of the twin-screw extruder are set as follows: Zone 1: 110 - 120 °C, Zone 2: 120 - 130 °C, Zone 3: 135 - 145 °C, Zone 4: 145 - 155 °C, Zone 5: 155 - 165 °C, Zone 6: 160 - 170 °C, Zone 7: 165 - 175 °C, Zone 8: 155 - 160 °C, Zone 9: 145 - 155 °C. The screw speed is 280 rpm, and the screw length-diameter ratio is 36:1.

[0061] Comparative Examples 1 - 11

[0062] The difference between each comparative example and the example lies only in the types and ratios of the components, as shown in Table 2.

[0063] Among the components of each example and comparative example,

[0064] The PVC resin 1 is S-50 produced by Formosa Plastics, with a degree of polymerization of 500 and a viscosity of 65 at 25°C.

[0065] The PVC resin 2 is TL-700 produced by LG, with a degree of polymerization of 700 and a viscosity of 80 at 25°C.

[0066] The PVC resin 3 is PVC JLTS-1 produced by Jinlu, with a degree of polymerization of 400 and a viscosity of 60 at 25°C.

[0067] The PVC resin 4 is TL-1000 produced by LG, with a degree of polymerization of 1000 and a viscosity of 113 at 25°C.

[0068] The cellulose is a cellulose product produced by Xinghengye, hydroxypropyl cellulose ether, with a purity of 99%, an average particle size of 120 μm, a viscosity of 300 at 20°C, and a molar substitution degree of 3.5 - 4.2.

[0069] The wood powder is a product produced by Runzejin, with an average particle size of 125 μm.

[0070] The bamboo powder is a product produced by Jusil Mining, with an average particle size of 150 μm.

[0071] The calcium carbonate is AC-MLT04 produced by Meilitai (purity ≥ 90 wt%), with an average particle size of 1.6 μm.

[0072] The magnesium oxide is a magnesium oxide product produced by Luolan Chemical Industry (purity ≥ 90 wt%), with an average particle size of 15 μm.

[0073] The talc powder is 777A produced by Tianyuan Chemical Industry, with an average particle size of 5 μm.

[0074] The antioxidant is a mixture of a commercially available hindered phenol antioxidant and a commercially available phosphite antioxidant compounded at a mass ratio of 1.5:1.

[0075] The stabilizer 1 is commercially available zinc stearate.

[0076] The stabilizer 2 is commercially available calcium stearate.

[0077] The stabilizer 3 is commercially available magnesium stearate.

[0078] The lubricant is commercially available polyethylene wax.

[0079] Unless otherwise specified, the component raw materials used in each example and comparative example of the present invention are all commercially available raw materials, and the component raw materials used in each parallel experiment are of the same kind.

[0080] Table 1

[0081]

[0082] Table 2

[0083]

[0084] In order to verify the performance of the cellulose composite PVC material of the present invention, the products prepared in each example and comparative example were subjected to the following performance tests, and the specific steps are as follows:

[0085] (1) Initial decomposition temperature test: directly tested using a NETZSCH thermogravimetric analyzer, model TG 209F1. The test method was in a nitrogen atmosphere, heating from room temperature to 750 °C at a heating rate of 20 °C / min and stopping, and recording the temperature at which the material mass decomposed by 1% as the initial decomposition temperature;

[0086] (2) Surface resistance test; directly tested using the test method of GB / T 1410-2006;

[0087] (3) Odor level test: tested using the standard method of PV 3900:2000. The odor level was divided into 6 levels in total. Level 1 represents no odor, Level 2 represents an obvious odor, Level 3 represents a very obvious odor but not offensive, Level 4 represents an acceptable odor, Level 5 represents a very unpleasant odor, and Level 6 represents an intolerable odor. The levels can be distinguished by 0.1 level.

[0088] The test results are shown in Tables 3 and 4.

[0089] Table 3

[0090]

[0091] Table 4

[0092]

[0093] As can be seen from Tables 3 and 4, the initial decomposition temperature of the product of the present invention can reach above 240 °C, and at the same time, the volume resistance can reach 2.8×10 13Above Ω, the odor level can reach below 3.5 levels, and the comprehensive performance is excellent. This shows that the specific selection and combination of cellulose, filler, and stabilizer in the product of the present invention can effectively improve the thermal stability and odor property of the product, and at the same time can also ensure or even enhance the electrical insulation property of the product. However, it can be seen from Examples 1 to 3 and Comparative Examples 1 to 2 that the introduction amount of cellulose in the product also has a crucial impact on the performance of the product. If the addition amount is too small, the thermal stability of the product cannot be fully solved, and at the same time its electrical insulation property is not ideal, and the odor level is also relatively high. When the addition amount of this component is too much, the filler and stabilizer can no longer inhibit the characteristics and side reactions of this component itself. As shown in the product of Comparative Example 2, compared with the products of Examples 1 to 3, the initial decomposition temperature of the product decreases significantly, the odor level increases, and the volume resistivity drops to a level lower than that of the product of Comparative Example 1. On the other hand, due to the large differences in structure and composition among different biomass types, if biomass other than cellulose powder is selected as the modification component, the filler and stabilizer may not be able to synergistically interact with it. As shown in Comparative Examples 3 and 4, the comprehensive performance of the product is not as expected. Similarly, when other conventional optional types are selected for the filler and stabilizer, such as Comparative Examples 5 to 6 and Comparative Examples 10 to 11, it can be seen that the product cannot inhibit the negative effects brought about by the introduction of cellulose, and the insulation performance and thermal stability of the product are not ideal. And it can be seen from Example 1, Examples 10 to 12, and Comparative Examples 7 to 9 that when the filler in the product is selected as the type defined in the present invention, not any ratio can achieve the expected effect. When the amount of magnesium oxide is too small, the filler cannot effectively adsorb the odor molecules emitted by PVC and inhibit the acidic substances generated by cellulose itself. However, if the amount of calcium carbonate is too small, the insulation property of the material will decrease. Therefore, the two need to be maintained in the range of 1:1 to 8:1, especially when the preferred ratio is 3:1 to 5:1, the comprehensive performance of the product is better. It can be seen from the product performance of Example 1 and Examples 7 to 9 that when the components remain unchanged, the change in the degree of polymerization and viscosity of the PVC resin has a certain impact on the performance of the product. With the increase in the degree of polymerization and viscosity, the decomposition temperature and electrical insulation property of the product both increase to a certain extent. However, when the degree of polymerization reaches above 800 and the viscosity continues to increase, the decomposition temperature and electrical insulation property of the product will decrease to a certain extent.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A cellulose composite PVC material, characterized in that, It comprises the following components in parts by weight: 75 - 105 parts of PVC resin, 15 - 35 parts of cellulose powder, 3 - 10 parts of stabilizer, 2 - 12 parts of filler; The cellulose powder is at least one of ethyl cellulose ether, acetyl cellulose ether, hydroxyethyl cellulose ether, and hydroxypropyl cellulose ether; The filler is a mixture of calcium carbonate and magnesium oxide, and the mass ratio of the two is (1:1) - (8:1); The stabilizer is zinc stearate.

2. The cellulose composite PVC material according to claim 1, wherein For the mixture of calcium carbonate and magnesium oxide, the mass ratio of the two is (3:1) - (5:1).

3. The cellulose composite PVC material according to claim 1, wherein The average particle size D50 of the calcium carbonate is 0.8 - 2 μm, and the average particle size D50 of the magnesium oxide is 13 - 18 μm.

4. The cellulose composite PVC material according to claim 1, wherein The average particle size of the cellulose powder is 90 - 125 μm, the viscosity is 150 - 400 mPa·s, and the molar substitution degree is 3.5 - 4.

2.

5. The cellulose composite PVC material according to claim 1, wherein The degree of polymerization of the PVC resin is 400 - 1000.

6. The cellulose composite PVC material according to claim 1, wherein The components further include 1 - 4 parts of processing aids, and the processing aids include 0.2 - 0.6 parts of antioxidant and 1.2 - 3 parts of lubricant.

7. The cellulose composite PVC material according to claim 6, wherein The antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants, and the lubricant is at least one of polyethylene wax and stearic acid.

8. The preparation method of the cellulose composite PVC material according to any one of claims 1 to 7, characterized in that, It comprises the following steps: Heat the PVC resin, stabilizer, and lubricant to 75 - 85 °C and mix evenly, then add the cellulose powder and antioxidant and heat to 100 - 120 °C and mix evenly. Finally, add the filler, mix, and place it into a twin-screw extruder for melt extrusion granulation to obtain the cellulose composite PVC material.

9. Use of the cellulose composite PVC material according to any one of claims 1 - 7 in the preparation of electrical components.

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