CN114369366B

CN114369366B - Dynamic vulcanization thermoplastic elastomer silicone rubber and preparation method thereof

Info

Publication number: CN114369366B
Application number: CN202210065414.7A
Authority: CN
Inventors: 王彦君; 刘强; 王彦富; 董晓颖
Original assignee: Shandong Tairuifeng New Material Co ltd
Current assignee: Shandong Tairuifeng New Material Co ltd
Priority date: 2022-01-19
Filing date: 2022-01-19
Publication date: 2022-09-09
Anticipated expiration: 2042-01-19
Also published as: CN114369366A

Abstract

The invention discloses a dynamic vulcanization thermoplastic elastomer silicone rubber and a preparation method thereof, wherein the silicone rubber is prepared from the following raw materials in parts by weight: 10-90 parts of TPU, 10-90 parts of TPEE, 40-200 parts of silicon rubber, 0.5-5 parts of compatilizer, 5-100 ppm (calculated by platinum) of catalyst, 1-10 parts of cross-linking agent, 6-10 parts of flame retardant and 3-10 parts of reinforcing filler; the total parts of TPU and TPEE is 100 parts; the thermoplastic elastomer silicone rubber is prepared by mixing the raw materials, stirring, melt blending and extruding by a double-screw extruder and dynamic vulcanization; compared with the existing dynamic vulcanized TPU/silicone rubber, the dynamic vulcanized thermoplastic elastomer silicone rubber provided by the invention has excellent heat resistance and solvent resistance, and simultaneously has good tearing strength, permanent deformation resistance and smooth handfeel, and can be used in high-requirement application fields of automobile parts, mechanical equipment and the like.

Description

Dynamic vulcanization thermoplastic elastomer silicone rubber and preparation method thereof

Technical Field

The invention belongs to the technical field of thermoplastic elastomers, and particularly relates to a dynamically vulcanized thermoplastic elastomer silicone rubber and a preparation method thereof.

Background

Dynamic vulcanization means that rubber is vulcanized in a melting and banburying process of rubber and thermoplastic polymer, and vulcanized rubber is dispersed in a thermoplastic polymer matrix. This blend combines the elasticity of rubber with the thermoplastic polymer as a matrix phase which in turn imparts repeatable processability. Thermoplastic polyurethane (hereinafter referred to as TPU) is a block copolymer which contains repeated carbamate groups (-NHCOO-) on a molecular chain and is formed by alternately connecting hard segments and soft segments, has very excellent comprehensive performance and excellent rebound resilience, is cold-resistant, oil-resistant and wear-resistant, and is widely applied to industries of automobiles, shoe making, cables and the like. But the TPU has poor hydrolysis resistance, poor hand feeling and poor biocompatibility. The silicone rubber has excellent biocompatibility and skin touch, outstanding high and low temperature resistance, hydrolysis resistance and weather resistance, but has certain defects in the aspects of mechanical strength, oil resistance and the like; and the vulcanized and crosslinked silicone rubber loses reworkability.

Chinese patent CN1568351A discloses a method for dynamically vulcanizing TPU/silicone rubber. Wherein the silicone rubber is dispersed in the TPU matrix and dynamically vulcanized by a hydrosilylation reaction. The obtained dynamic vulcanization thermoplastic elastomer integrates the excellent mechanical property of TPU and the hand feeling of silicon rubber, and has better comprehensive performance. However, the TPU matrix phase also has some disadvantages, such as poor solvent resistance, especially poor resistance to polar solvents such as ethanol and acetone, which results in poor resistance of the dynamically vulcanized TPU/silicone rubber to wiping by alcohol; secondly, the thermal aging resistance of the TPU is not sufficient and long-term use at temperatures above 80 ℃ is not possible.

Disclosure of Invention

The invention provides a dynamically vulcanized thermoplastic elastomer silicone rubber and a preparation method thereof, aiming at solving the technical problems of poor solvent resistance and insufficient heat resistance of the existing dynamically vulcanized TPU/silicone rubber thermoplastic elastomer.

In order to solve the technical problems, the invention adopts a technical scheme that: a dynamic vulcanization thermoplastic elastomer silicone rubber is composed of the following raw materials in parts by weight: 10-90 parts of TPU, 10-90 parts of thermoplastic polyester elastomer (TPEE), 40-200 parts of silicone rubber, 0.5-5 parts of compatilizer, 5-100 ppm (calculated by platinum) of catalyst, 1-10 parts of cross-linking agent, 6-10 parts of flame retardant and 3-10 parts of reinforcing filler;

the total parts of TPU and TPEE is 100 parts.

Further, the TPU is selected from polyester TPU, polyether TPU or aliphatic TPU, and the hardness range of the TPU is selected from Shore A40 to Shore D70.

Furthermore, the hardness range of the TPEE is selected from Shore A50 to Shore D75.

The silicone rubber is selected from commercial methyl vinyl silicone rubber containing reinforcing filler, and the hardness range of the silicone rubber is selected from Shore A20-Shore A90.

Further, the cross-linking agent is hydrogen-containing silicone oil containing at least 2 Si-H bonds, and the hydrogen content of the cross-linking agent is selected from 0.1-3.0 wt%.

Further, the catalyst is Pt and a compound or a complex thereof, and the effective Pt content is 200-20000 ppm.

Further, the compatilizer is any one of gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropyltriethoxysilane, aminopropyl terminated polysiloxane, amino terminated polysiloxane, hydroxyalkyl terminated polysiloxane, epoxy terminated polysiloxane, polyurethane-siloxane copolymer, maleic anhydride grafted ethylene vinyl acetate copolymer and maleic anhydride grafted ethylene acrylate copolymer.

Further, the flame retardant is obtained by compounding magnesium hydroxide and chitosan, wherein the weight part ratio of the magnesium hydroxide to the chitosan is 2:1-5: 1; the reinforcing filler is selected from one or two of hydrophobic fumed silica and hydrophobic precipitated silica, and the specific surface area of the hydrophobic fumed silica is100～300m ² /g。

A preparation method of dynamically vulcanized thermoplastic elastomer silicone rubber comprises the following steps:

step (1): adding TPU, TPEE, silicon rubber, a compatilizer and a crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 60-100 ℃ at 500rpm/min under 300-;

step (2): and (2) adding the mixture obtained in the step (1) into a double-screw extruder, continuously blending, melting and extruding at the temperature of 180 ℃ and 230 ℃ and at the rotating speed of 350 rpm and 600rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Further, in the process of melting and extruding the product by the double-screw extruder, the charging barrels of all the zone machines of the extruder rotate in different directions while the double screws are tightly meshed and rotate in different directions, and the method specifically comprises the following steps:

the double-screw extruder comprises a PLC control system, a first motor, a second motor, a first transmission device, a second transmission device, a rack, a feeding device and a machine charging barrel;

the machine charging barrel comprises: the device comprises a machine charging barrel shell, a continuous rotatable machine charging barrel from a first zone to a sixth zone, a counter-rotating double-screw structure in the machine charging barrel and a tail end discharging machine head;

the counter-rotating twin screw structure comprises: screw A, screw B; the screw A and the screw B rotate in different directions;

the first motor is connected with a first transmission device, and the first transmission device is connected with the counter-rotating double-screw structure to meet the rotation of a screw A and a screw B in the double-screw structure;

the second motor is connected with a second transmission device, and the second transmission device is connected with the charging barrels of the continuous rotatable first-sixth zone sub machines to meet the rotation of the charging barrels of each zone sub machine;

the rotating direction of the first zone machine charging barrel, the third zone machine charging barrel and the fifth zone machine charging barrel is the same as the rotating direction of the screw A;

the rotating directions of the two-zone machine charging barrel, the four-zone machine charging barrel and the six-zone machine charging barrel are the same as the rotating direction of the screw B;

the ratio of the rotating speed of the sub machine charging barrels in the first area to the rotating speed of the double-screw structure is 1-1.5: under the condition of a certain double-screw rotating speed, the rotating speed of the charging barrels of the submachine in one to six zones is adjusted, the high efficiency of melting, homogenizing and dynamic vulcanization of a mixture in a double-screw extruder is improved, the compatibility among raw materials such as TPU, TPEE, silicon rubber and the like is further improved, and the mechanical property and the solvent resistance of the prepared thermoplastic elastomer silicon rubber are improved;

the PLC control system is used for setting parameters such as transmission power, heating temperature, double-screw rotating speed and sub-machine charging barrel rotating speed of the double-screw extruder, controlling a melting extrusion process and ensuring safety and high efficiency of a preparation process.

Further, the corona treatment in the Ar atmosphere in the step (1) specifically includes:

continuously adding a catalyst, a flame retardant and a reinforcing filler into the mixture in the vacuum stirrer, uniformly mixing again, vacuumizing to 100-500 Pa of vacuum degree, keeping the room temperature, introducing high-purity Ar gas at the rate of 650-;

the gas cylinder filled with Ar gas is connected with the gas inlet of the vacuum stirrer through a pipeline, a gas flow control meter is arranged on the pipeline, a gas cylinder valve is adjusted through data displayed by the gas flow control meter, and Ar gas with stable flow is introduced into the stirrer;

the inner side wall of the stirrer is provided with a plurality of corona treatment reactors, in the process of stirring the mixture in Ar atmosphere, a corona treatment control platform in an operating system of the vacuum stirrer is started, the corona treatment reactors are excited to ionize Ar gas, the mixture is continuously stirred, the surface of the thermoplastic elastomer mixture is modified under the surface discharge of Ar gas plasma, the roughness of the surface of the mixture is increased, the surface active sites of auxiliary agents such as TPU, TPEE, surface functional groups of silicon rubber materials, catalysts and the like are activated, the mutual combination of the materials is promoted through stirring, the cross-linking reaction among the mixture is enhanced and prolonged, and all the auxiliary agents are uniformly loaded on the TPU, TPEE and silicon rubber mixed materials.

The invention has the beneficial effects that:

the invention provides a dynamic vulcanization thermoplastic elastomer silicone rubber and a preparation method thereof, and TPEE with excellent heat resistance and solvent resistance is introduced. The TPEE can be used at the temperature of more than 120 ℃, and the tensile strength at high temperature is far higher than that of TPU; TPEE also has excellent oil resistance and is resistant to most polar liquid chemical media at room temperature. Therefore, compared with the existing dynamic vulcanization TPU/silicone rubber, the dynamic vulcanization thermoplastic elastomer silicone rubber provided by the invention has better heat resistance and solvent resistance.

According to the dynamic vulcanization thermoplastic elastomer silicone rubber and the preparation method thereof provided by the invention, in the process of melting and extruding a product by a double-screw extruder, the double screws are tightly meshed and rotate in different directions, meanwhile, the charging barrels of all the sub-machines of the extruder also rotate in different directions, and the rotating speed of the charging barrels of all the sub-machines in one to six zones is adjusted under the condition that the rotating speed of the double screws is fixed, so that the high efficiency of melting, homogenizing and dynamic vulcanization of a mixture in the double-screw extruder is improved, the compatibility among the raw materials such as TPU, TPEE, silicone rubber and the like is further improved, and the mechanical property, the solvent resistance and the heat resistance of the prepared thermoplastic elastomer silicone rubber are improved; the production process is safe and efficient.

According to the dynamically vulcanized thermoplastic elastomer silicone rubber and the preparation method thereof provided by the invention, the surface of the thermoplastic elastomer mixture material is modified under the Ar gas plasma discharge, the roughness of the mixture surface is increased, the surface functional groups of TPU, TPEE and silicone rubber materials and the surface active sites of additives such as catalysts are activated, the mutual combination of the materials is promoted through stirring, the cross-linking reaction among the mixtures is enhanced and prolonged, so that all the additives are uniformly loaded on the TPU, TPEE and silicone rubber mixture material, and a basis is provided for preparing the dynamically vulcanized thermoplastic elastomer silicone rubber with better performance.

The dynamic thermoplastic elastomer vulcanized silicone rubber provided by the invention has good tear strength, permanent deformation resistance and smooth hand feeling, and can be used in high-requirement application fields of automobile parts, mechanical equipment, wires and cables, medical instruments, wearable equipment and the like.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.

The following raw materials were used in the examples:

TPU1 polyester TPU, hardness 70A;

TPU2 polyester TPU, hardness 90A;

TPU3 polyether TPU, hardness 80A;

TPEE1 hardness 80A;

TPEE2 hardness 90A;

silicone rubber 1 hardness 70A;

silicone rubber 2 hardness 40A;

1 part of compatilizer: an aminopropyl terminated polysiloxane;

a compatilizer 2: grafting EVA with maleic anhydride;

a compatibilizer 3: gamma-aminopropyltrimethoxysilane;

crosslinking agent 1: methyl-terminated hydrogen-containing silicone oil having a hydrogen content of 0.5 wt%;

crosslinking agent 2: methyl-terminated hydrogen-containing silicone oil with a hydrogen content of 2.0 wt%;

catalyst 1: chloroplatinic acid-vinyltetramethylsiloxane complex solution (concentration 2000ppm, in terms of platinum content);

catalyst 2: chloroplatinic acid, isopropanol diluted 100 times;

flame retardant 1: magnesium hydroxide and chitosan in a weight ratio of 2:1, compounding;

flame retardant 2: magnesium hydroxide and chitosan in a weight ratio of 5:1, compounding;

reinforcing filler 1: the specific surface area is 100m ² (ii) hydrophobic fumed silica per gram;

reinforcing filler 2: the specific surface area is 300m ² Hydrophobic in gFumed silica;

in addition to the above components, suitable processing aids may be added, including but not limited to fillers, antioxidants, ultraviolet light stabilizers, hydrolytic stabilizers, flame retardants, pigments or mineral fillers, and the like, as are well known in the art, polymeric processing aids and co-fillers.

Example 1

Step (1): adding 150 parts of TPU, 150 parts of TPEE, 1100 parts of silicone rubber, 12 parts of compatilizer and 12 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 110 ppm of catalyst, 16 parts of flame retardant and 13 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuing stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the temperature of 190 ℃ and the rotating speed of 450rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Example 2

Step (1): adding 150 parts of TPU, 150 parts of TPEE, 1150 parts of silicone rubber, 12 parts of compatilizer and 12 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 110 ppm of catalyst, 18 parts of flame retardant and 110 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuing stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the temperature of 190 ℃ and the rotating speed of 400rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Example 3

Step (1): adding 120 parts of TPU, 180 parts of TPEE, 1100 parts of silicone rubber, 12 parts of compatilizer and 12 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 110 ppm of catalyst, 110 parts of flame retardant and 15 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuing stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the temperature of 190 ℃ and the rotating speed of 500rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Example 4

Step (1): adding 250 parts of TPU, 250 parts of TPEE, 1100 parts of silicone rubber, 14 parts of compatilizer and 14 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 120 ppm of catalyst, 26 parts of flame retardant and 23 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuing stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the temperature of 200 ℃ and the rotating speed of 450rpm of the extruder, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Example 5

Step (1): adding 220 parts of TPU, 280 parts of TPEE, 2150 parts of silicone rubber, 26 parts of compatilizer and 22 parts of cross-linking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 230 ppm of catalyst, 28 parts of flame retardant and 25 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuously stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the extruder temperature of 220 ℃ and the rotation speed of 550rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Example 6

Step (1): adding 350 parts of TPU, 250 parts of TPEE, 2100 parts of silicon rubber, 22 parts of compatilizer and 26 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 220 ppm of catalyst, 210 parts of flame retardant and 210 parts of reinforcing filler, stirring and mixing at 100rpm/min, vacuumizing at room temperature, carrying out corona treatment for 5-15min under Ar atmosphere, and continuously stirring for 1h to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the temperature of 200 ℃ and the rotating speed of 500rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

Comparative example 1

Step (1): adding 1100 parts of TPU, 1100 parts of silicone rubber, 12 parts of compatilizer and 12 parts of crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 110 ppm of catalyst, continuously stirring, and vacuumizing for 2 hours under the condition of 500Pa vacuum degree to obtain a mixture;

Comparative example 2

Step (1): adding 2100 parts of TPU, 2150 part of silicone rubber, 26 parts of compatilizer and 22 parts of cross-linking agent into a high-speed mixer, uniformly mixing, stirring and heating to 70-80 ℃ at 500rpm/min, stirring for 10-12min, transferring into a vacuum stirrer, adding 130 ppm of catalyst, continuously stirring, and vacuumizing for 2 hours under the vacuum degree of 500Pa to obtain a mixture;

step (2): and (2) adding the mixture obtained in the step (1) into a screw extruder, continuously blending, melting and extruding at the extruder temperature of 220 ℃ and the rotation speed of 500rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

The samples of examples 1-6 and comparative examples 1-2 were injection molded and tested for properties, with the results given in Table 1:

TABLE 1 results of Performance test of examples 1 to 6 and comparative examples 1 to 2

As can be seen from the data in Table 1, the thermoplastic elastomer silicone rubbers of examples 1-6 incorporating TPEE are compared to the comparative examples 1-2 silicone rubbers not containing TPEE:

the mechanical property and the hardness of the thermoplastic elastomer silicone rubber are greatly improved, and the mechanical property and the hardness are improved to the greatest extent in example 4;

the thermoplastic elastomer silicone rubber has significantly reduced tensile set, especially as shown in the test results of example 3;

as can be seen from the data of the hot air aging 72h test at 150 ℃ and the volume swelling test in acetone for 24h at room temperature, the tensile strength change in hot air aging and the volume swelling change in acetone of the thermoplastic elastomer silicone rubbers prepared in examples 1-6 are both significantly lower than those of comparative examples 1-2, which shows that the thermoplastic elastomer silicone rubbers prepared by dynamic vulcanization by introducing TPEE in the invention and blending with TPU, silicone rubber and other raw materials have excellent aging resistance, heat resistance and polar solvent resistance.

In addition, the dynamically vulcanized thermoplastic elastomer silicone rubber prepared in the embodiment of the invention also keeps good physical and mechanical properties and smooth hand feeling, and can be used in high-requirement application occasions such as automobile parts, mechanical equipment, wires and cables, medical appliances and wearable equipment.

Example 7

In the above method for preparing dynamically vulcanized thermoplastic elastomer silicone rubber of examples 1-6 and comparative examples 1-2, in the process of melt-extruding the product by a twin-screw extruder, the charging barrels of the extruder are also rotated in different directions while the twin-screw is tightly meshed with each other and rotated in different directions, specifically:

the machine feed cylinder comprises: the machine charging barrel comprises a machine charging barrel shell, a continuous rotatable one-six zone machine charging barrel, a counter-rotating double-screw structure in the machine charging barrel and a tail end discharging machine head;

the ratio of the rotating speed of the sub machine charging barrels in the first area to the rotating speed of the double-screw structure is 1-1.5: 1;

and the PLC control system is used for setting parameters such as transmission power, heating temperature, double-screw rotating speed, sub-machine charging barrel rotating speed and the like of the double-screw extruder and controlling the melting extrusion process.

The working principle and the beneficial effects of the embodiment are as follows: under the condition of a certain double-screw rotating speed, the rotating speed of the charging barrel of each submachine in one to six areas is adjusted, so that the high efficiency of melting, homogenizing and dynamic vulcanization of a mixture in a double-screw extruder is improved, and the compatibility among the raw materials such as TPU, TPEE, silicon rubber and the like is further improved, so that the mechanical property, the solvent resistance and the heat resistance of the prepared thermoplastic elastomer silicon rubber are improved; the whole production process is safe and efficient.

Example 8

In the above method for preparing a dynamically vulcanized thermoplastic elastomer silicone rubber according to examples 1 to 6, the corona treatment in an Ar atmosphere in step (1) specifically includes:

continuously adding a catalyst, a flame retardant and a reinforcing filler into the mixture in the vacuum stirrer, uniformly mixing again, vacuumizing to 100Pa vacuum degree, keeping room temperature, introducing high-purity Ar gas at a rate of 650mL/min under the condition of current of 0.3A to generate plasma, and carrying out corona treatment on the mixture in a stirring state for 15min at 150w power;

the gas cylinder filled with Ar gas is connected with the gas inlet of the vacuum stirrer through a pipeline, a gas flow control meter is arranged on the pipeline, a valve of the gas cylinder is adjusted through data displayed by the gas flow control meter, and Ar gas with stable flow is introduced into the stirrer;

the inside wall of the stirrer is provided with a plurality of corona treatment reactors, the mixture is stirred under Ar atmosphere, a corona treatment control platform in a vacuum stirrer operating system is started, the corona treatment reactors are excited to ionize Ar gas, the mixture is continuously stirred, and the surface of the mixture is modified by Ar gas plasma discharge to form a thermoplastic elastomer mixture material.

The working principle and the beneficial effects of the embodiment are as follows: the mixture in a stirring state is subjected to corona treatment in Ar atmosphere, so that the roughness of the surface of the mixture is increased, surface functional groups of TPU, TPEE and silicon rubber materials, surface active sites of catalysts and other auxiliaries are activated, the mutual combination of the materials is promoted through stirring, the cross-linking reaction among the mixture is enhanced and prolonged, all the auxiliaries are uniformly loaded on the TPU, TPEE and silicon rubber mixed material, and a foundation is provided for preparing dynamic vulcanization thermoplastic elastomer silicon rubber with better performance.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification, or any other related technical fields directly or indirectly, are included in the scope of the present invention.

Claims

1. A dynamically vulcanized thermoplastic elastomer silicone rubber is characterized in that: the composition is characterized by comprising the following raw materials in parts by weight: 10-90 parts of TPU, 10-90 parts of TPEE, 40-200 parts of silicon rubber, 0.5-5 parts of compatilizer, 5-100 ppm of catalyst, 1-10 parts of crosslinking agent, 6-10 parts of flame retardant and 3-10 parts of reinforcing filler; the content of the catalyst is calculated by platinum;

the total parts of TPU and TPEE is 100 parts;

the flame retardant is obtained by compounding magnesium hydroxide and chitosan, wherein the weight part ratio of the magnesium hydroxide to the chitosan is 2:1-5: 1; the reinforcing filler is one or two selected from hydrophobic fumed silica and hydrophobic precipitated silica, and the specific surface area of the hydrophobic fumed silica is 100-300 m ² /g；

The preparation method comprises the following preparation steps:

step (1): adding TPU, TPEE, silicon rubber, a compatilizer and a crosslinking agent into a high-speed mixer, uniformly mixing, stirring and heating to 60-100 ℃ at the speed of 500rpm/min under 300-;

step (2): and (2) adding the mixture in the step (1) into a double-screw extruder, continuously blending, melting and extruding at the temperature of the extruder of 180-230 ℃ and the rotating speed of 350-600rpm, and dynamically vulcanizing to obtain the thermoplastic elastomer silicone rubber.

2. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: the TPU is selected from polyester TPU, polyether TPU or aliphatic TPU, and the hardness range of the TPU is selected from Shore A40-Shore D70; the hardness range of the TPEE is selected from Shore A50-Shore D75.

3. A dynamically vulcanising thermoplastic elastomer silicone rubber according to claim 1, characterized in that: the silicone rubber is selected from commercial methyl vinyl silicone rubber containing reinforcing filler, and the hardness range of the silicone rubber is selected from Shore A20-Shore A90.

4. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: the cross-linking agent is hydrogen-containing silicone oil containing at least 2 Si-H bonds, and the hydrogen content of the cross-linking agent is selected from 0.1-3.0 wt%.

5. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: the catalyst is Pt and a compound or a complex thereof, and the effective Pt content is 200-20000 ppm.

6. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: the compatilizer is any one of gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropyltriethoxysilane, aminopropyl terminated polysiloxane, amino terminated polysiloxane, hydroxyalkyl terminated polysiloxane, epoxy terminated polysiloxane, polyurethane-siloxane copolymer, maleic anhydride grafted ethylene vinyl acetate copolymer and maleic anhydride grafted ethylene acrylate copolymer.

7. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: in the process of melting and extruding a product by the double-screw extruder, the charging barrels of all the zone machines of the extruder also rotate in different directions while the double screws are tightly meshed and rotate in different directions, and the process specifically comprises the following steps:

the counter-rotating twin screw structure comprises: screw A and screw B; the screw A and the screw B rotate in different directions;

8. The dynamically vulcanized thermoplastic elastomer silicone rubber according to claim 1, wherein: the corona treatment in Ar atmosphere in the step (1) specifically comprises the following steps:

continuously adding a catalyst, a flame retardant and a reinforcing filler into the mixture in the vacuum stirrer, uniformly mixing again, vacuumizing to 100-500 Pa vacuum degree, keeping the room temperature, introducing high-purity Ar gas at the rate of 650 plus 800mL/min under the current of 0.2-0.5A to generate plasma, and carrying out corona treatment on the mixture in the stirring state for 5-15min at the power of 100 plus 200 w;