High-tear-strength high-flame-retardance sheath material and preparation method thereof
阅读说明：本技术 一种高撕裂强度高阻燃的护套材料及其制备方法 (High-tear-strength high-flame-retardance sheath material and preparation method thereof ) 是由 史伟才 伍清浴 曹明灏 俞江定 于 2020-12-23 设计创作，主要内容包括：本发明提供了一种高撕裂强度高阻燃的护套材料,所述护套材料的原料包括以下质量百分比成分：苯乙烯类热塑性弹性体：18-35％,聚烯烃树脂：15-30％,增塑剂：0-10％,聚苯醚树脂：8-14％,磷氮系阻燃剂：25-36％,交联剂稀释剂：1-2％,抗氧剂：0.1-1％,抗老化剂：0.5-1.5％,加工助剂：0.5-2％。本发明提供的护套材料具有高撕裂强度和高阻燃性能,大大提高了数据线等消费电子线缆的使用安全性。(The invention provides a high-tear-strength high-flame-retardant sheath material, which comprises the following raw materials in percentage by mass: styrenic thermoplastic elastomer: 18 to 35%, polyolefin resin: 15-30%, plasticizer: 0-10%, polyphenylene ether resin: 8-14%, phosphorus-nitrogen flame retardant: 25-36%, crosslinker diluent: 1-2%, antioxidant: 0.1-1%, anti-aging agent: 0.5-1.5%, processing aid: 0.5 to 2 percent. The sheath material provided by the invention has high tearing strength and high flame retardant property, and greatly improves the use safety of data lines and other consumer electronic cables.)
1. The high-tear-strength high-flame-retardant sheath material is characterized by comprising the following raw materials in percentage by mass:
styrenic thermoplastic elastomer: 18 to 35 percent of the total weight of the mixture,
polyolefin resin: 15-30 percent of the total weight of the mixture,
plasticizer: 0 to 10 percent of the total weight of the mixture,
polyphenylene ether resin: 8 to 14 percent of the total weight of the mixture,
phosphorus-nitrogen flame retardant: 25 to 36 percent of the total weight of the mixture,
cross-linking agent diluent: 1 to 2 percent of the total weight of the mixture,
antioxidant: 0.1 to 1 percent of the total weight of the mixture,
anti-aging agent: 0.5 to 1.5 percent of,
processing aid: 0.5 to 2 percent.
2. The high tear strength high flame retardant jacket material of claim 1, wherein the styrenic thermoplastic elastomer is styrene-ethylene-butylene-styrene copolymer, the styrene content of the styrene-ethylene-butylene-styrene copolymer is 40-60 wt%, wherein 10 wt% or more of styrene is randomly distributed in the ethylene-butylene soft segment, and the remaining styrene is located at both ends of the copolymer.
3. The sheath material with high tear strength and high flame retardance as claimed in claim 1, wherein the polyolefin resin has a crystallinity of 70% or more.
4. The sheath material with high tear strength and high flame retardance as claimed in claim 1 or 3, wherein the polyolefin resin is a co-polypropylene with a crystallinity of 70% or more and a melt index of less than 30g/10min at 230 ℃ under a load of 2.16 kg.
5. The sheath material with high tear strength and high flame retardance as claimed in claim 1, wherein the particle size of the polyphenylene ether resin is not less than 200 meshes, and the intrinsic viscosity is 30-40cm3/g。
6. The sheath material with high tear strength and high flame retardance as claimed in claim 1, wherein the phosphorus-nitrogen flame retardant is diethyl hypophosphite and melamine cyanurate, and the mass ratio of the phosphorus-nitrogen flame retardant to the melamine cyanurate is (0.5-1): 1, and (b) a complex formed.
7. The sheath material with high tear strength and high flame retardance as claimed in claim 6, wherein the particle size D98 of the diethylphosphinate and the melamine cyanurate is 10 μm or less.
8. The high tear strength high flame retardant jacket material according to claim 1, wherein said cross-linking agent diluent is a mixture of absolute ethyl alcohol and a cross-linking agent, and the content of the cross-linking agent is 5-20 wt%.
9. The high tear strength high flame retardant jacket material of claim 8, wherein said cross-linking agent is one or more of 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, dicumyl peroxide, di-t-butylperoxy dicumyl.
10. The preparation method of the sheath material with high tear strength and high flame retardance as claimed in claim 1, characterized by comprising the following steps:
(1) mixing a styrenic thermoplastic elastomer and a plasticizer;
(2) putting the mixture and other components except the crosslinking diluent into a high-speed mixer, uniformly mixing, and then adding the crosslinking diluent through a liquid injection port of the high-speed mixer;
(3) and adding the mixed materials into a double-screw extruder for extrusion and granulation.
Technical Field
The invention belongs to the technical field of polymers, and relates to a high-tear-strength high-flame-retardance sheath material and a preparation method thereof.
Background
With the upgrading of consumer electronics equipment, the charging speed is faster and faster, and the potential safety hazard is increased, so that the attention of various consumer electronics manufacturers to the outer coating materials of consumer electronics cables such as data lines is increased continuously, and the requirements are higher and higher.
The styrene thermoplastic elastomer (TPE) has the advantages of light specific gravity, easy processing, good elasticity, high strength, comfortable hand feeling, good high and low temperature resistance, excellent weather resistance, no halogen and o-benzene plasticizer and recyclability, so the styrene thermoplastic elastomer (TPE) is widely used in the field of consumer electronics, such as data lines and power lines. But the TPE material belongs to a nonpolar olefin structure, the crystallinity is very low, and in addition, in order to improve the processing performance and increase the softness of the TPE, a large amount of plasticizer white oil is added, so that the acting force between molecular chains is greatly weakened, and the tearing strength of the TPE material is low. And to the data line that fire-retardant requirement is very strict, a large amount of fire retardants are filled unavoidably, and this has further worsened TPE's tear strength, and data line sheath is thinner in addition, if little damage appears in TPE material epidermis, stress concentration in the damaged department in the frequent use process, very easy expansion becomes big crackle, leads to data line skin fracture, influences consumer and uses and even causes the accident. Cracking of halogen-free flame retardant TPE data lines occurs in large quantities each year, but unfortunately, the improvement of tear strength of halogen-free flame retardant TPE materials is not ideal at present. Therefore, in order to make the data line safer to use, the development of halogen-free flame retardant TPE materials with higher tear strength is imperative.
Disclosure of Invention
Aiming at the defects in the prior art, the material obtained by blending the material components and the preparation method has high tearing strength and high flame retardant property, and the use safety of the data line and other consumer electronic cables is greatly improved.
One purpose of the invention is realized by the following technical scheme: the high-tear-strength high-flame-retardant sheath material comprises the following raw materials in percentage by mass:
styrenic thermoplastic elastomer: 18 to 35 percent of the total weight of the mixture,
polyolefin resin: 15-30 percent of the total weight of the mixture,
plasticizer: 0 to 10 percent of the total weight of the mixture,
polyphenylene ether resin: 8 to 14 percent
Phosphorus-nitrogen flame retardant: 25 to 36 percent of the total weight of the mixture,
cross-linking agent diluent: 1 to 2 percent of the total weight of the mixture,
antioxidant: 0.1 to 1 percent of the total weight of the mixture,
anti-aging agent: 0.5 to 1.5 percent of,
processing aid: 0.5 to 2 percent.
Preferably, the styrene thermoplastic elastomer is styrene-ethylene-butylene-styrene copolymer, the styrene content in the styrene-ethylene-butylene-styrene copolymer is 40-60 wt%, wherein more than or equal to 10 wt% of styrene is randomly distributed in an ethylene-butylene soft segment, and the rest styrene is positioned at two ends of the copolymer.
Preferably, the polyolefin resin has a crystallinity of 70% or more.
Preferably, the polyolefin resin is a copolymerized polypropylene having a crystallinity of 70% or more and a melt index of less than 30g/10min at 230 ℃ under a load of 2.16 kg.
Preferably, the polyphenylene ether resin has a particle size of 200 mesh or more and an intrinsic viscosity of 30-40cm3/g。
Preferably, the phosphorus-nitrogen flame retardant is diethyl hypophosphite and melamine cyanurate, and the mass ratio of (0.5-1): 1, and (b) a complex formed.
Preferably, the particle size D98 of the diethylphosphinate and the melamine cyanurate is 10 μm or less.
Preferably, the crosslinking agent diluent is a mixture of absolute ethyl alcohol and a crosslinking agent, and the content of the crosslinking agent is 5-20 wt%.
Preferably, the cross-linking agent is one or more of 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, dicumyl peroxide and di-tert-butylperoxy dicumyl.
Preferably, the plasticizer is one or more of white oil, liquid paraffin and naphthenic oil.
Preferably, the anti-aging agent is one or more of a benzophenone-based ultraviolet absorber, a benzotriazole-based light stabilizer, and a hindered amine-based light stabilizer.
Preferably, the antioxidant is one or more of hindered phenol antioxidants and phosphite antioxidants. Hindered phenolic antioxidants include, but are not limited to, antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1024, and the like. Phosphite antioxidants include, but are not limited to, antioxidant 168, antioxidant 626, antioxidant TP80, and the like.
Preferably, the processing aid is silicone master batch, preferably silicone with molecular weight more than 100 ten thousand, and the carrier is LLDPE.
The other purpose of the invention is realized by the following technical scheme: the preparation method of the high-tear-strength and high-flame-retardant sheath material comprises the following raw materials in percentage by mass:
styrenic thermoplastic elastomer: 18 to 35 percent of the total weight of the mixture,
polyolefin resin: 15-30 percent of the total weight of the mixture,
plasticizer: 0 to 10 percent of the total weight of the mixture,
polyphenylene ether resin: 8 to 14 percent
Phosphorus-nitrogen flame retardant: 25 to 36 percent of the total weight of the mixture,
cross-linking agent diluent: 1 to 2 percent of the total weight of the mixture,
antioxidant: 0.1 to 1 percent of the total weight of the mixture,
anti-aging agent: 0.5 to 1.5 percent of,
processing aid: 0.5 to 2 percent.
The preparation method comprises the following steps:
(1) mixing a styrenic thermoplastic elastomer and a plasticizer;
(2) putting the mixture and other components except the crosslinking diluent into a high-speed mixer, uniformly mixing, and then adding the crosslinking diluent through a liquid injection port of the high-speed mixer;
(3) and adding the mixed materials into a double-screw extruder for extrusion granulation, wherein the rotating speed of the screw is 300-220 ℃ and the processing temperature is set between 300-600 r/min.
Compared with the prior art, the invention has the beneficial effects that:
(1) the SEBS with the styrene content of 40-60 wt% is adopted, so that the compatibility with the polyphenyl ether resin is good, and the overall strength of the material is improved;
(2) according to the invention, the high-crystallinity polyolefin resin is introduced, so that the crystallinity of the material is improved, and the tearing strength of the TPE material is further improved due to more crystalline regions;
(3) according to the invention, the superfine powdered polyphenyl ether resin with the particle size of more than or equal to 200 meshes is adopted, so that the polyphenyl ether is better melted and plasticized during processing, and the influence on the tearing strength is reduced;
(4) according to the invention, the halogen-free phosphorus-nitrogen flame retardant with smaller particle size is added, so that the adverse effect of the flame retardant on the tearing strength is greatly reduced, and the flame retardant property of the material is improved;
(5) according to the invention, the crosslinking agent is diluted to ensure that the crosslinking agent is uniformly dispersed in the material, so that the TPE material is uniformly subjected to micro-crosslinking reaction during screw extrusion processing, and the tearing strength of the material is further improved.
Detailed Description
Hereinafter, embodiments will be described in detail with respect to the high tear strength high flame retardant jacket material of the present invention, however, these embodiments are exemplary and the present disclosure is not limited thereto.
In some embodiments of the invention, the raw materials of the sheath material with high tear strength and high flame retardance comprise the following components in percentage by mass:
styrenic thermoplastic elastomer: 18 to 35 percent of the total weight of the mixture,
polyolefin resin: 15-30 percent of the total weight of the mixture,
plasticizer: 0 to 10 percent of the total weight of the mixture,
polyphenylene ether resin: 8 to 14 percent of the total weight of the mixture,
phosphorus-nitrogen flame retardant: 25 to 36 percent of the total weight of the mixture,
cross-linking agent diluent: 1 to 2 percent of the total weight of the mixture,
antioxidant: 0.1 to 1 percent of the total weight of the mixture,
anti-aging agent: 0.5 to 1.5 percent of,
the styrenic thermoplastic elastomer is preferably a styrene-ethylene-butylene-styrene copolymer (SEBS) having a styrene content of 40 to 60 wt%, wherein 10 wt% or more of styrene is randomly distributed in the ethylene-butylene soft segment and the remaining styrene is located at both ends of the copolymer, such as SEBS manufactured by Kentum corporation under the trade name A1536. The SEBS has higher styrene content, and is beneficial to improving the compatibility of the SEBS and the polyphenyl ether resin, thereby improving the overall strength of the material; at least 10 wt% of the polyethylene is distributed in the ethylene-butene soft segments, which allows the SEBS to be processed without the addition of plasticizers.
The polyolefin resin is preferably a polyolefin having a crystallinity of 70% or more. The high-crystallinity polyolefin resin further improves the tearing strength of the TPE material. Polyolefins may be listed as polypropylene, polyethylene or mixtures of polypropylene and polyethylene. The polypropylene and polyethylene may be homopolymeric or copolymeric.
Further preferably, the polyolefin resin is a copolymerized polypropylene having a crystallinity of 70% or more and a melt index of less than 30g/10min under a load of 2.16kg at 230 ℃, such as a copolymerized polypropylene having a trade name BX3500 manufactured by SK chemical Co., Ltd. The high-crystalline copolymerized polypropylene has good compatibility with SEBS, and the low melt index is beneficial to improving the strength of the SEBS material.
The polyphenyl ether resin is preferably powder, the particle size is preferably larger than or equal to 200 meshes, and the particle size of the polyphenyl ether resin is smaller, so that better melting and plasticizing of the polyphenyl ether during processing are facilitated, and the influence on the tear strength of the material is reduced. Further preferably, the intrinsic viscosity is 30 to 40cm3(ii) polyphenylene ether in g.
The phosphorus-nitrogen flame retardant is preferably diethyl hypophosphite or melamine cyanurate, and the mass ratio of (0.5-1): 1, more preferably diethyl hypophosphite and melamine cyanurate, in a mass ratio (0.6-0.8): 1, and (b) a complex formed. The diethyl hypophosphorous acid and the melamine cyanurate are compounded in a proper proportion, so that a good synergistic effect can be generated, and the flame retardant property of the material is improved. The diethyl hypophosphite can be one or more of diethyl aluminum hypophosphite, magnesium diethyl hypophosphite and zinc diethyl hypophosphite.
The particle size D98 of the adopted diethyl hypophosphite and melamine cyanurate is preferably less than or equal to 10 μm, namely, the number of particles with the particle size less than or equal to 10 μm in the powder accounts for 98 percent of the total number of particles. The diethyl hypophosphite and the melamine cyanurate with smaller particle size are selected, so that the adverse effect of the flame retardant on the tearing strength is greatly reduced, and the overall strength of the material is favorably improved.
The raw materials of the sheath material comprise a cross-linking agent, and the material is cross-linked in the extrusion granulation process by adding the cross-linking agent, so that a complex network structure is formed, and the strength of the material is improved. The cross-linking agent is preferably added in the form of a cross-linking agent diluent, namely, the cross-linking agent is diluted by absolute ethyl alcohol to form a mixture of the absolute ethyl alcohol and the cross-linking agent, so that the cross-linking agent is uniformly dispersed in the material, the halogen-free flame-retardant TPE material is enabled to uniformly generate micro-crosslinking reaction during screw extrusion processing, and the tear strength of the material is further improved. The cross-linking agent and the diluent are added into the mixer for dispersion after being evenly mixed with other raw materials.
The cross-linking agent is preferably one or more of 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane (DHBP), dicumyl peroxide (DCP) and di-tert-butylperoxy dicumyl peroxide (BIPB). In the crosslinking agent diluent, the content of the crosslinking agent is preferably 5 to 20 wt%.
Hereinafter, the technical solution of the present invention will be further described and illustrated by specific examples. However, these embodiments are exemplary, and the present disclosure is not limited thereto. Unless otherwise specified, the raw materials used in the following specific examples of the present invention are those commonly used in the art, and the methods used in the examples are those conventional in the art.
In the following examples, the raw materials used are as follows:
SEBS A1536 is SEBS produced by Keteng of America, and the styrene content is 41%;
SEBS 511 is SEBS produced by Yueyangbailing petrochemical production, and the styrene content is 42%;
SEBS 6153 is SEBS produced by Taber rubber group, and the content of styrene is 30%;
PP BX3500 is a highly crystalline copolymerized propylene produced by Korea SK chemical Co., Ltd., and has a melt index (230 ℃ C., 2.16Kg) of: 10g/10 min;
PP 7033N is a highly crystalline copolypropene (ExxonMobil, USA) with a melt index (230 ℃, 2.16Kg) of: 8g/10 min;
PE 8003 is HDPE produced by Tai plastic group;
PP 5012XT is random copolymerization PP produced by the plastic-set group, and the crystallinity is less than or equal to 60 percent;
PPO LXR 035 is polyphenylene oxide resin produced by Ruicheng division of Ranunculus maekengi of China, and has intrinsic viscosity of 35cm3The particle size of the PPO LXR 035 powder is more than or equal to 200 meshes, and the particle size of the PPO LXR 035 powder is less than 200 meshes;
AST-50-513 is silicone master batch produced by Shanghai philosophy.
The raw materials of the sheath materials of examples 1 to 5 and comparative examples 1 to 5 are shown in tables 1 and 2, and the raw material of the sheath material of comparative example 6 differs from that of example 1 only in that: comparative example 6 the same mass of DCP as in example 1 was used, without using a DCP ethanol solution, and the other steps were the same as in example 1.
The sheath materials of examples 1 to 5 and comparative examples 1 to 5 were prepared as follows:
(1) firstly, SEBS and white oil are mixed and filled with oil;
(2) putting the oil-filled SEBS and the components except the crosslinking diluent into a high-speed mixer to be uniformly mixed, and slowly adding the crosslinking diluent through a liquid injection port of the high-speed mixer in the stirring process to uniformly disperse the crosslinking diluent in the material;
(3) the mixed raw materials are added into a double-screw extruder for extrusion granulation, the rotating speed of the screw is 500 r/min, and the processing temperature is set between 180 ℃ and 220 ℃.
The sheath material of comparative example 6 was prepared as follows:
(1) firstly, SEBS and white oil are mixed and filled with oil;
(2) putting the oil-filled SEBS and other components containing the cross-linking agent into a high-speed mixer to be uniformly mixed;
(3) the mixed raw materials are added into a double-screw extruder for extrusion granulation, the rotating speed of the screw is 500 r/min, and the processing temperature is set between 180 ℃ and 220 ℃.
And (3) performance testing: the sheathing materials prepared in examples 1 to 5 and comparative examples 1 to 6 were prepared into standard test bars according to standards and subjected to various tests, and the results of the performance tests of the sheathing materials of examples 1 to 5 are shown in Table 1 and the results of the performance tests of the sheathing materials of comparative examples 1 to 6 are shown in Table 2.
Table 1 mass percentages of raw material components and performance data for sheath materials of examples 1-5
Table 2 mass percentages and performance data for raw material components of comparative example 1-6 sheathing materials
Through the examples and the comparative example, the sheath materials prepared in the examples 1 to 5 have excellent tear resistance and can reach the flame retardant level of VW-1; the comparative example 1 uses more plasticizers, the acting force between polymer molecular chains is reduced seriously, so that the tearing strength is reduced more than that of the example 1, the flame-retardant effect is poor, and the VW-1 test cannot be achieved; compared with the example 2, the SEBS 6153 with the styrene content of 30 wt% is adopted in the comparative example 2, the tear strength of the material is reduced, and the hardness is higher; comparative example 3 employs random copolymerized polypropylene, the crystallinity of which is < 60%, resulting in a significant decrease in tear strength of comparative example 3; comparative example 4 uses a polyphenylene ether resin in the form of pellets, which has a relatively large particle size and cannot be completely plasticized during processing, reducing the tear strength; the comparative example 5 uses diethyl hypophosphite and melamine cyanurate with larger particle size, so that the compatibility of the nitrogen-phosphorus composite flame retardant and the TPE material is poor, the mechanical property of the material is obviously reduced, the tearing strength is also reduced in a small range, and the VW-1 test has large fluctuation and cannot pass the VW-1 test; comparative example 6 in which the crosslinking agent was directly added, the dispersion promoting effect of ethanol was lacking, so that the micro-crosslinking reaction between the crosslinking agent and the high molecular polymer was affected and the tear strength was reduced.
The invention carries out deep research aiming at the tearing resistance mechanism of the halogen-free flame-retardant TPE material, and finally, the tearing resistance of the halogen-free flame-retardant TPE material is greatly improved through the combined action of multiple dimensions, so that the C-type notch tearing strength of the material reaches more than 50N/mm, and is equivalent to that of the halogen-free flame-retardant TPU material (the C-type notch tearing strength is 55N/mm in the Elastollan 1193A 10 FHF test of the halogen-free flame-retardant TPU material produced by Germany Basff).
The specific embodiments described herein are merely illustrative of the spirit of the invention and do not limit the scope of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.