阅读说明：本技术 紫外光交联聚烯烃母粒的制备方法 (Preparation method of ultraviolet light crosslinked polyolefin master batch ) 是由 欧阳观林 毛宇迪 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种紫外光交联聚烯烃母粒的制备方法,该制备方法包括：将聚烯烃与填料预混合得到混合料A,将抗氧剂、光引发剂、交联剂预混合得到混合料B；然后将混合料A、B与分散剂混合,进行首次密炼；再加入琉基改性硅油进行二次密炼,最后将密炼机内温度升高至预设温度,进行三次密炼,得到密炼产物；将上述密炼产物制备得到初母粒后,通过紫外光辐照系统进行紫外光交联反应,得到紫外光交联聚烯烃母粒。本发明通过分多步反应,有效避免光引发剂和交联剂遇高温时发生蒸发现象,并采用紫外光交联技术进行交联,效率高、速度快,最终得到的母粒能有效提高制品的耐高温性能和力学性能；该制备方法工艺简单、操作方便、节能环保。(The invention discloses a preparation method of ultraviolet light cross-linked polyolefin master batch, which comprises the following steps: premixing polyolefin and filler to obtain a mixture A, and premixing an antioxidant, a photoinitiator and a crosslinking agent to obtain a mixture B; then mixing the mixture A, B with a dispersant for primary banburying; adding the sulfo-modified silicone oil for secondary banburying, and finally raising the temperature in the banbury mixer to a preset temperature for tertiary banburying to obtain a banburying product; and (3) after the banburying product is prepared into primary master batches, carrying out ultraviolet crosslinking reaction by an ultraviolet irradiation system to obtain ultraviolet crosslinking polyolefin master batches. According to the invention, through multi-step reaction, the phenomenon of evaporation of the photoinitiator and the cross-linking agent when the photoinitiator and the cross-linking agent meet high temperature is effectively avoided, and the ultraviolet cross-linking technology is adopted for cross-linking, so that the efficiency is high, the speed is high, and the finally obtained master batch can effectively improve the high temperature resistance and the mechanical property of the product; the preparation method has the advantages of simple process, convenient operation, energy conservation and environmental protection.)

1. The preparation method of the ultraviolet light crosslinked polyolefin master batch is characterized by comprising the following steps:

s1, polyolefin and a filler are uniformly mixed to obtain a mixture A;

s2, uniformly mixing the antioxidant, the photoinitiator and the cross-linking agent to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer for primary internal mixing for 10-20 min;

s4, adding the modified silicon oil into the S3 after primary banburying, carrying out secondary banburying, raising the temperature in the banbury mixer to a preset temperature after banburying for 10-20min, carrying out tertiary banburying, and carrying out banburying for 30-40min to obtain a banburying product;

s5, preparing the banburying product in the S4 to obtain a primary master batch, and irradiating the primary master batch through an ultraviolet irradiation system to obtain ultraviolet light crosslinked polyolefin master batch.

2. The method for preparing the ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the ultraviolet crosslinked polyolefin masterbatch comprises the following raw materials in parts by weight: 100 parts of polyolefin, 30-40 parts of filler, 2-3 parts of antioxidant, 0.3-2 parts of photoinitiator, 1-4 parts of cross-linking agent, 0.1-3 parts of dispersing agent and 0.5-5 parts of modified silicon oil.

3. The preparation method of the ultraviolet light crosslinking polyolefin masterbatch according to claim 1 or 2, wherein the filler is one or more of mica, talcum powder, silicon dioxide and titanium dioxide; the dispersing agent is polyethylene wax; the antioxidant is dilauryl thiodipropionate and 6-tert-butyl m-cresol, and the mass ratio of the dilauryl thiodipropionate to the 6-tert-butyl m-cresol is 1: 1.

4. The method for preparing the ultraviolet light cross-linking polyolefin master batch according to claim 1 or 2, wherein the photoinitiator is one or more of 2-hydroxy-2-methylphenyl propane-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, 4-methylbenzophenone and 4-ethyl dimethylaminobenzoate; the cross-linking agent is one or more of triallyl isocyanurate, tricarboxymethylpropyl trimethacrylate and ethylene glycol dimethacrylate.

5. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the mixing time in S1 is 20-30min, and the obtained mixture A is dried at 90-100 ℃ for 4-6 h.

6. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the mixing condition in S2 is negative pressure mixing in a vacuum closed mixer for 10-30 min.

7. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the first banburying in S3 is performed at room temperature, and the rotation speed of the banbury mixer is 100-200 r/min.

8. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the secondary banburying in S4 is performed at room temperature, and the rotation speed of the banbury mixer is 20-80 r/min; the preset temperature is 140-165 ℃, and the rotating speed is 500-1000 r/min.

9. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the banburying product in S5 is prepared to obtain a primary masterbatch, which comprises:

putting the banburying product into a feed inlet of an extruder, and preparing to obtain the primary master batch through extrusion, granulation and sieving; wherein the extrusion temperature is 150 ℃ and 240 ℃, and the particle size of the primary master batch after sieving is 2-5 mm.

10. The method for preparing ultraviolet crosslinked polyolefin masterbatch according to claim 1, wherein the platform temperature of the ultraviolet irradiation in S5 is 90-100 ℃, and the irradiation light intensity is 300-²。

Technical Field

The invention belongs to the technical field of macromolecules, and particularly relates to a preparation method of ultraviolet light crosslinked polyolefin master batch.

Background

Currently, common crosslinking methods for crosslinking polyolefin materials are: peroxide chemical crosslinking, high energy radiation crosslinking, silane crosslinking, and ultraviolet crosslinking. Wherein, the peroxide chemical crosslinking method has the defects of low production efficiency, complex process flow and large energy consumption; the high-energy radiation crosslinking method has complex equipment, large investment and harsh protection conditions; the silane crosslinking method relates to hydrolysis reaction, and has the advantages of long crosslinking time, complex process operation, and low pressure and temperature resistant grade of the product. The ultraviolet crosslinking method has the advantages of low equipment investment, simple process, energy conservation, environmental protection and high production efficiency.

Ultraviolet crosslinking is a recent method developed in recent years for producing crosslinked polyolefins, and an ultraviolet crosslinked polyolefin system mainly comprises a polyolefin base material, a photoinitiator and a crosslinking agent. However, the photoinitiator and the cross-linking agent have relatively small molecules, and are subjected to high temperature and mechanical stress in the processing process of the mixed material, so that the photoinitiator and the cross-linking agent are easily and rapidly evaporated at high temperature, the cross-linking efficiency of polyolefin is reduced, the irradiation time is prolonged, and the performance of the product is influenced to a certain extent.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a preparation method of ultraviolet crosslinking polyolefin master batch. According to the preparation method, the raw materials are subjected to multi-step reaction in the early stage, the phenomenon that the photoinitiator and the cross-linking agent are evaporated when meeting high temperature can be effectively avoided, the ultraviolet cross-linking technology is adopted for cross-linking, the efficiency is high, the speed is high, and the finally prepared master batch can effectively improve the high-temperature resistance and the mechanical property of the product. The preparation method has the advantages of simple process, convenient operation, energy conservation and environmental protection.

In order to achieve the purpose, the invention provides a preparation method of ultraviolet light crosslinking polyolefin master batch, which comprises the following steps:

s1, polyolefin and a filler are uniformly mixed to obtain a mixture A;

s2, uniformly mixing the antioxidant, the photoinitiator and the cross-linking agent to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer for primary internal mixing for 10-20 min;

s4, adding the modified silicon oil into the S3 after primary banburying, carrying out secondary banburying, raising the temperature in the banbury mixer to a preset temperature after banburying for 10-20min, carrying out tertiary banburying, and carrying out banburying for 30-40min to obtain a banburying product;

s5, preparing the banburying product in the S4 to obtain a primary master batch, and irradiating the primary master batch through an ultraviolet irradiation system to obtain ultraviolet light crosslinked polyolefin master batch.

In the above publication S1, the polyolefin and the filler are thoroughly mixed in advance to obtain a compounded material a. In S2, the antioxidant, the photoinitiator and the crosslinking agent are fully mixed in advance to obtain a mixture B so as to improve the high-temperature resistance and the oxidation resistance of the subsequent processing process and the product. Wherein, the pre-sufficient mixing can be that the materials in the steps are added into a mixer or an internal mixer for uniform mixing.

In the disclosure, before matching the banburying temperature of polyolefin, adding the sulfur-based modified silicone oil to mix with the mixture A and the mixture B, and carrying out secondary material-mixing for 10-20 min. Because the sulfhydryl modified silicone oil is polydimethylsiloxane containing sulfhydryl in a side chain or a terminal group, the polydimethylsiloxane has relatively low vapor pressure, is not easy to volatilize, has heat resistance, weather resistance, hydrophobicity and small surface tension, and can form a layer of protective film on the surface of the polyolefin polymer. And then, raising the temperature in the internal mixer to a preset temperature, and carrying out internal mixing for 30-40min for three times, wherein a protective film formed on the surface of the polyolefin polymer can effectively prevent the photoinitiator and the cross-linking agent from volatilizing in the subsequent high-temperature internal mixing process.

And (3) carrying out ultraviolet crosslinking reaction on the primary master batch prepared from the banburying product to obtain ultraviolet crosslinked polyolefin master batch. By adding the sulfenyl modified silicone oil, the evaporation phenomenon of the photoinitiator and the crosslinking agent in high temperature can be effectively protected, the subsequent ultraviolet crosslinking reaction can be favorably carried out, and the heat resistance and the volatility of the surface of the prepared polymer can be effectively improved; meanwhile, the sulfur groups in the molecules can react with ultraviolet rays, and the later-stage ultraviolet crosslinking is not influenced.

Further, in the above technical scheme, the raw materials of the ultraviolet light crosslinked polyolefin masterbatch comprise, by weight, 100 parts of polyolefin, 30-40 parts of filler, 2-3 parts of antioxidant, 0.3-2 parts of photoinitiator, 1-4 parts of crosslinking agent, 0.1-3 parts of dispersant, and 0.5-5 parts of modified hydrophobic silicone oil. Specifically, the polyolefin may be one or more of high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-octene copolymer, maleic anhydride grafted polyethylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, and maleic anhydride grafted ethylene-octene copolymer.

Further, in the above technical scheme, the inorganic filler is one or more of mica, talc powder, silica and titanium dioxide. The dispersing agent is polyethylene wax. According to the technical scheme, the mica, the talcum powder, the silicon dioxide and the titanium dioxide have good insulating and high-temperature resistant characteristics, and can be used as a filler to be mixed with polyolefin, so that the mechanical strength, the toughness, the adhesive force, the ageing resistance, the corrosion resistance and the like of a polyolefin product can be improved.

Further, in the above technical scheme, the antioxidant is dilauryl thiodipropionate and 6-tert-butyl m-cresol in a mass ratio of 1: 1.

In the technical scheme, dilauryl thiodipropionate is an oil-soluble antioxidant, has low toxicity and good oxidation resistance and stability. Under the processing condition of 30min at 200 ℃, the loss rate of the dilauryl thiodipropionate is only 0.7 percent, and the dilauryl thiodipropionate has excellent thermal stability. 6-tert-butyl-m-cresol is a typical thiobisphenol antioxidant, and has double functions of a free radical terminator and a hydroperoxide decomposer due to the structural particularity, so that the physical properties (such as tensile strength, elongation, melt index and the like), the electrical properties and high thermal stability of raw materials in a mixture can be maintained, and the weather resistance and the ageing resistance of a product can be enhanced.

Further, in the above technical scheme, the photoinitiator is one or more of 2-hydroxy-2-methylphenyl propane-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, 4-methylbenzophenone and 4-ethyl dimethylaminobenzoate. The cross-linking agent is one or more of triallyl isocyanurate, tricarboxymethylpropyl trimethacrylate and ethylene glycol dimethacrylate. In the technical scheme, the photoinitiators are all high-efficiency photoinitiators, so that the initiation efficiency is high, and the ultraviolet crosslinking efficiency is high.

Further, in the technical scheme, the mixing time in the S1 is 20-30min, and the obtained mixture A is dried for 4-6h at 90-100 ℃. According to the technical scheme, the mixture A is dried for 4-6 hours at the temperature of 90-100 ℃ to remove moisture absorbed in the reaction process and prevent the subsequent reaction from being affected.

Further, in the above technical scheme, the mixing condition in S2 is to mix for 10-30min in a vacuum closed mixer.

Further, the first internal mixing in the technical scheme S3 is performed at room temperature, and the rotation speed of the internal mixer is 100-.

Further, the secondary banburying is carried out at room temperature in the technical scheme S4, and the rotating speed of the banbury mixer is 20-80 r/min. The temperature of the third banburying is 140-165 ℃, and the rotating speed is 500-1000 r/min. According to the technical scheme, the mixing degree and the film forming property of the raw materials can be effectively increased by carrying out staged banburying and controlling the temperature and the rotating speed of each stage, so that the follow-up ultraviolet crosslinking reaction is facilitated.

Further, the banburying product in the technical scheme S5 is prepared to obtain the primary masterbatch, which includes: putting the banburying product into a feed inlet of an extruder, and preparing to obtain the primary master batch through extrusion, granulation and sieving; wherein the extrusion temperature is 150 ℃ and 240 ℃, and the particle size of the primary master batch after sieving is 2-5 mm. In the technical scheme, the temperature and the particle size of the extruded material are strictly controlled, and the obtained particle size is uniform, so that the speed and the effect of the subsequent ultraviolet crosslinking reaction are improved.

Further, in the above technical scheme S5, the platform temperature of the ultraviolet irradiation is 90-100 ℃, and the irradiation light intensity is 300-600mW/cm². Specifically, the total irradiation energy may be 5000-²。

The invention has the beneficial effects that:

1. the invention can improve the high temperature resistance and oxidation resistance of the initiator and the cross-linking agent in the processing process by mixing the photoinitiator and the cross-linking agent with the antioxidant in advance.

2. According to the invention, the sulfhydryl modified silicone oil is added before high-temperature banburying, so that a layer of protective film can be formed on the surface of the polyolefin polymer.

3. According to the invention, the raw materials are reacted in multiple steps, so that the phenomenon of evaporation of the photoinitiator and the cross-linking agent when the photoinitiator and the cross-linking agent meet high temperature can be effectively avoided, the ultraviolet cross-linking technology is utilized for cross-linking, the efficiency is high, the speed is high, and the finally prepared master batch can effectively improve the high temperature resistance and the mechanical property of the product.

4. The preparation method has the advantages of simple process, convenient operation, no evaporation escape of reactants, high crosslinking efficiency, energy conservation and environmental protection.

Detailed Description

The experimental procedures in the following examples are conventional unless otherwise specified. The raw materials in the following examples are all commercially available products and are commercially available, unless otherwise specified.

The present invention is described in further detail below with reference to examples:

example 1

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin and filler into a mixer, mixing for 20min, and drying at 90 ℃ for 6h to obtain a mixture A;

s2, adding an antioxidant, a photoinitiator and a crosslinking agent into a vacuum closed mixer, and mixing for 10min under negative pressure to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer, internally mixing for 20min for the first time at room temperature, and controlling the rotating speed of the internal mixer to be 200 r/min;

s4, adding the sulfur-based modified silicone oil, carrying out secondary banburying at room temperature for 20min, and controlling the rotating speed of a banbury mixer to be 20 r/min; then, raising the temperature in the internal mixer to 140 ℃, adjusting the rotating speed to 1000r/min, and carrying out internal mixing for 30min for three times to obtain a final internal mixing product;

s5, extruding, granulating and sieving the banburying product in the S4 at the temperature of 150 ℃ to prepare primary master batch with the particle size of 2 mm; the platform temperature of the ultraviolet irradiation system is controlled to be 90 ℃, and the irradiation light intensity is controlled to be 300mW/cm²Total irradiation energy of 5000mJ/cm²And irradiating the prepared primary master batch by an ultraviolet irradiation system, and cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 30 parts of talcum powder, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol (1: 1, 2 parts of mixture, 0.3 part of 2-hydroxy-2-methyl phenyl propane-1-ketone, 1 part of triallyl isocyanurate, 1 part of polyethylene wax and 0.5 part of sulfenyl modified silicone oil.

Observations in the above preparation process: no obvious steam exists in the equipment in the preparation process, and the irradiation completion time is 5.6 s.

Example 2

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin and filler into a mixer, mixing for 25min, and drying at 95 ℃ for 5h to obtain a mixture A;

s2, adding an antioxidant, a photoinitiator and a crosslinking agent into a vacuum closed mixer, and mixing for 20min under negative pressure to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer, internally mixing for 15min for the first time at room temperature, and controlling the rotating speed of the internal mixer to be 150 r/min;

s4, adding the sulfur-based modified silicone oil, carrying out secondary banburying at room temperature for 15min, and controlling the rotating speed of a banbury mixer to be 50 r/min; then, raising the temperature in the internal mixer to 150 ℃, adjusting the rotating speed to 800r/min, and carrying out internal mixing for 35min for three times to obtain an internal mixing product;

s5, extruding, granulating and sieving the banburying product in the S4 at the temperature of 200 ℃ to prepare a primary master batch with the particle size of 3 mm; the platform temperature of the ultraviolet irradiation system is controlled to be 95 ℃, and the irradiation light intensity is controlled to be 400mW/cm²The total irradiation energy is 6000mJ/cm²And irradiating the prepared primary master batch by an ultraviolet irradiation system, and cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 35 parts of mica, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol of 1: 1, 2.5 parts of a mixture, 1 part of benzoin dimethyl ether, 2 parts of tricarboxymethyl propyl trimethacrylate, 1 part of polyethylene wax and 3 parts of sulfhydryl-modified silicone oil.

Observations in the above preparation process: no obvious steam exists in the equipment in the preparation process, and the irradiation completion time is 6.3 s.

Example 3

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin and filler into a mixer, mixing for 30min, and drying at 100 ℃ for 4h to obtain a mixture A;

s2, adding an antioxidant, a photoinitiator and a crosslinking agent into a vacuum closed mixer, and mixing for 30min under negative pressure to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer, internally mixing for 20min for the first time at room temperature, and controlling the rotating speed of the internal mixer to be 100 r/min;

s4, adding the sulfur-based modified silicone oil, carrying out secondary banburying at room temperature for 10min, and controlling the rotating speed of a banbury mixer to be 80 r/min; then, raising the temperature in the internal mixer to 165 ℃ and adjusting the rotating speed to 500r/min, and carrying out internal mixing for 40min for three times to obtain an internal mixing product;

s5, extruding, granulating and sieving the banburying product in the S4 at the temperature of 240 ℃ to prepare primary master batch with the particle size of 5 mm; the platform temperature of the ultraviolet irradiation system is controlled to be 100 ℃, and the irradiation light intensity is controlled to be 600mW/cm²The total irradiation energy is 8000mJ/cm²And irradiating the prepared primary master batch by an ultraviolet irradiation system, and cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 40 parts of silicon dioxide, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol of 1: 1, 2 parts of ethyl 4-dimethylaminobenzoate, 4 parts of ethylene glycol dimethacrylate, 3 parts of polyethylene wax and 5 parts of thiol-modified silicone oil.

Observations in the above preparation process: no obvious steam exists in the equipment in the preparation process, and the irradiation completion time is 6.8 s.

Comparative example 1

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin, an antioxidant, a photoinitiator, a crosslinking agent and a filler into a mixer, mixing, stirring for 25min, and drying the mixture at 95 ℃ for 5 h;

s2, adding the mixture obtained in the step S1 and a dispersing agent into an internal mixer, carrying out internal mixing for 15min at room temperature, and controlling the rotating speed of the internal mixer to be 150 r/min;

s3, adding the sulfur-based modified silicone oil, carrying out secondary banburying at room temperature for 15min, and controlling the rotating speed of a banbury mixer to be 50 r/min; then, raising the temperature in the internal mixer to 150 ℃, adjusting the rotating speed to 800r/min, and carrying out internal mixing for 35min for three times to obtain an internal mixing product;

s4, carrying out extrusion, granulation and sieving on the banburying product in the S3 at the temperature of 200 ℃ to prepare a primary product with the particle size of 3mmMaster batches; the platform temperature of the ultraviolet irradiation system is controlled to be 95 ℃, and the irradiation light intensity is controlled to be 400mW/cm²The total irradiation energy is 6000mJ/cm²And irradiating the prepared primary master batch by an ultraviolet irradiation system, and cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 35 parts of mica, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol of 1: 1, 2.5 parts of a mixture, 1 part of benzoin dimethyl ether, 2 parts of tricarboxymethyl propyl trimethacrylate, 1 part of polyethylene wax and 3 parts of sulfhydryl-modified silicone oil.

Observations in the above preparation process: during the preparation process, a small amount of steam exists in the equipment, and the irradiation completion time is 8.6 s.

Comparative example 2

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin and filler into a mixer, mixing for 25min, and drying at 95 ℃ for 5h to obtain a mixture A;

s2, adding an antioxidant, a photoinitiator and a crosslinking agent into a vacuum closed mixer, and mixing for 20min under negative pressure to obtain a mixture B;

s3, adding the mixture A in the S1, the mixture B in the S2 and a dispersing agent into an internal mixer, internally mixing for 15min for the first time at room temperature, and controlling the rotating speed of the internal mixer to be 150 r/min;

s4, raising the temperature in the internal mixer to 150 ℃, adjusting the rotating speed to 800r/min, and internally mixing for 35min again to obtain an internally mixed product;

s5, extruding, granulating and sieving the banburying product in the S4 at the temperature of 200 ℃ to prepare a primary master batch with the particle size of 3 mm; the platform temperature of the ultraviolet irradiation system is controlled to be 95 ℃, and the irradiation light intensity is controlled to be 400mW/cm²The total irradiation energy is 6000mJ/cm²And irradiating the prepared primary master batch by an ultraviolet irradiation system, and cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 35 parts of mica, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol of 1: 1, 2.5 parts of a mixture, 1 part of benzoin dimethyl ether, 2 parts of tricarboxymethylpropyl trimethacrylate and 1 part of polyethylene wax.

Observations in the above preparation process: during the preparation process, obvious steam exists in the equipment, and the irradiation completion time is 9.9 s.

Comparative example 3

A preparation method of ultraviolet light cross-linked polyolefin master batch comprises the following steps:

s1, adding polyolefin, an antioxidant, a photoinitiator, a crosslinking agent and a filler into a mixer, mixing, stirring for 25min, and drying the mixture at 95 ℃ for 5 h;

s2, adding the mixture obtained in the step S1 and a dispersing agent into an internal mixer, mixing and reacting for 15min at room temperature under the condition that the rotating speed of the internal mixer is 150r/min, then raising the temperature in the internal mixer to 150 ℃, adjusting the rotating speed to 800r/min, and carrying out internal mixing for 35min again to obtain an internal mixing product;

s3, extruding, granulating and sieving the banburying product in the S2 at the temperature of 200 ℃ to obtain primary master batches with the particle size of 3 mm; the temperature of the irradiation platform is 95 ℃, and the irradiation light intensity is 400mW/cm²The total irradiation energy is 6000mJ/cm²After the ultraviolet irradiation system irradiates, cooling to obtain the ultraviolet crosslinked polyolefin master batch.

The ultraviolet-crosslinked polyolefin master batch comprises, by weight, 100 parts of polyolefin, 35 parts of mica, and a mass ratio of dilauryl thiodipropionate to 6-tert-butyl-m-cresol of 1: 1, 2.5 parts of a mixture, 1 part of benzoin dimethyl ether, 2 parts of tricarboxymethyl propyl trimethacrylate, 1 part of polyethylene wax and 3 parts of sulfhydryl-modified silicone oil.

Observations in the above preparation process: during the preparation process, a large amount of steam exists in the equipment, and the irradiation completion time is 13.6 s.

The ultraviolet light crosslinked polyolefin master batches prepared in the examples 1 to 3 and the comparative examples 1 to 3 were mixed with polypropylene in a weight ratio of 1:3 to prepare sample bars, and various performance tests were performed with reference to the standard in GB/T1040-2018, and the results are shown in Table 1.

TABLE 1 Performance parameters

The results in table 1 show that the performance indexes of examples 1 to 3 are superior to those of comparative examples 1 to 3, which shows that the ultraviolet crosslinked polyolefin masterbatch produced by the preparation method of the present invention can effectively improve the mechanical properties and high temperature resistance of polypropylene products.

From the process results and test results of example 2 and comparative example 1, it can be seen that in the case where the antioxidant, the photoinitiator and the crosslinking agent are not mixed in advance, a small amount of steam exists in the equipment, the irradiation time is prolonged during the ultraviolet crosslinking reaction, and the overall mechanical properties and high temperature resistance are improved to a certain extent. From the results of example 2 and comparative example 2, it can be seen that in the absence of added silyl-modified silicone oil, the presence of significant steam in the equipment prolongs the irradiation time during the uv crosslinking reaction, and at the same time, improves the overall mechanical properties and high temperature resistance. From the results of example 2 and comparative example 3, it can be seen that in the case where the antioxidant, the photoinitiator and the crosslinking agent are not mixed in advance and no silyl-modified silicone oil is added at the later stage, a large amount of steam exists in the apparatus, the irradiation time is prolonged during the ultraviolet crosslinking reaction, and the mechanical properties and high temperature resistance of the whole are improved poorly. According to the test results, the two steps of the invention can effectively avoid the evaporation of the photoinitiator and the cross-linking agent, thereby improving the ultraviolet crosslinking efficiency and the irradiation speed, and the prepared master batch can effectively improve the high temperature resistance and the mechanical property of the product.

In conclusion, the preparation method can effectively avoid the phenomenon that the photoinitiator and the cross-linking agent are evaporated when meeting high temperature, the cross-linking is carried out by utilizing the ultraviolet light cross-linking technology, the efficiency is high, the speed is high, and the finally obtained ultraviolet light cross-linked polyolefin master batch can effectively improve the mechanical property and the high temperature resistance of the product.

Finally, it should be emphasized that the above-described preferred embodiments of the present invention are merely examples of implementations, rather than limitations, and that many variations and modifications of the invention are possible to those skilled in the art, without departing from the spirit and scope of the invention.