Light-transmitting high-flame-retardant rubber sheath rubber and preparation method thereof

Abstract

The invention relates to the technical field of cable rubber, in particular to light-transmitting high-flame-retardant rubber sheath rubber which is prepared from the following raw materials in parts by weight: 20-40 parts of epichlorohydrin rubber, 20-60 parts of chlorinated polyethylene rubber and 20-40 parts of a flame-retardant EVA (Ethylene-Vinyl Acetate) composite material, the invention relates to a transparent flame-retardant plastic, which comprises, by weight, 20-35 parts of a plasticizer, 15-20 parts of fumed silica, 25-30 parts of highly compressive glass beads, 0.5-1 part of a coupling agent, 5-15 parts of an acid absorbent, 4-10 parts of zinc borate, 3-4 parts of peroxide, 2-4 parts of a crosslinking aid, and 3-4 parts of a transparent heat stabilizer. The transparent flame-retardant plastic has the advantages of good light transmission and excellent flame-retardant effect.

Description

Technical Field

[0001] The present application relates to the technical field of cable rubber, and in particular to a light-transmitting highly flame-retardant rubber sheath adhesive and a preparation method thereof. Background Art

[0002] At present, mining cables are widely used in large-scale mining equipment and transportation equipment in some mines, and the use environment is not lacking in dark environments such as underground mines and tunnels. In such environments, it is easy to cause accidents caused by accidental damage to cables during construction due to dim light. In order to avoid the above situation, luminous cables have a broad application market in mines and mines.

[0003] There are two main types of existing luminous cables: one is a cable with fluorescent powder or reflective tape added to the sheath, which absorbs sunlight and reflects light. This product cannot function underground or in an environment without light source and the sheath material is not light-transmitting; the other is a cable core with LED light strips. This type of product requires the cable sheath to have good light transmittance. Currently, the sheath of this type of cable is mostly thermoplastic polyurethane. Although this type of cable has good transparency, its flame retardant performance cannot meet the requirements of cables used underground in coal mines. Therefore, it is necessary to develop a highly flame retardant and light-transmitting rubber sheath. Summary of the invention

[0004] In order to improve the problems in the above-mentioned background technology, the present application provides a light-transmitting highly flame-retardant rubber sheath adhesive and a preparation method thereof.

[0005] The present application provides a light-transmitting highly flame-retardant rubber sheath adhesive adopts the following technical solution:

[0006] A light-transmitting highly flame-retardant rubber sheath adhesive is prepared from the following raw materials in parts by weight: 20-40 parts of epichlorohydrin rubber, 20-60 parts of chlorinated polyethylene rubber, 20-40 parts of flame-retardant EVA composite material, 20-35 parts of plasticizer, 15-20 parts of fumed silica, 25-30 parts of high-compression glass microbeads, 0.5-1 parts of coupling agent, 5-15 parts of acid absorbent, 4-10 parts of zinc borate, 3-4 parts of peroxide, 2-4 parts of cross-linking aid, and 3-4 parts of transparent heat stabilizer.

[0007] By adopting the above technical scheme, the raw materials work synergistically, and chloroether rubber and chlorinated polyethylene rubber as the main body provide good rubber elasticity and physical and mechanical properties; the flame-retardant EVA composite material gives the product excellent flame retardant properties; the plasticizer improves the processing performance and flexibility of the rubber compound; the fumed silica enhances the strength and wear resistance of the product; the high-compression glass microbeads, while ensuring a certain strength, help light to pass through due to their small particle size and uniform distribution, thereby improving the light transmittance of the product; the coupling agent enhances the interfacial bonding force between the components and improves the stability of the product; the acid absorbent can effectively absorb the acidic gas generated during the combustion process and reduce environmental pollution; zinc borate and other flame retardants work together to further enhance the flame retardant effect; the peroxide and the cross-linking aid jointly promote the cross-linking reaction of the rubber and improve the heat resistance and aging resistance of the product; the transparent heat stabilizer ensures the stability of the product during processing and use without affecting its light transmittance.

[0008] Preferably, the epichlorohydrin rubber is a ternary copolymer epichlorohydrin rubber.

[0009] By adopting the above technical scheme, the ternary copolymer chloroether adhesive (the main purpose is to be able to be co-vulcanized with the other two using peroxides) has better chemical stability and oil resistance. Compared with ordinary chloroether adhesive, its molecular structure is more regular (the ternary copolymer is not as regular as the homopolymer, so it has good cold resistance), which can effectively improve the comprehensive performance of the sheath adhesive, especially the performance in harsh environments.

[0010] Preferably, the chlorine content in the chlorinated polyethylene rubber is 40%.

[0011] By adopting the above technical solution, the chlorinated polyethylene rubber with a 40% chlorine content has good flexibility and processing performance while ensuring good flame retardancy, and has better compatibility with other raw materials, which is beneficial to improving the overall performance uniformity of the sheath rubber.

[0012] Preferably, the flame retardant EVA composite material is made of the following raw materials: EVA and DOPO, and the mass ratio of EVA to DOPO is 85:15.

[0013] By adopting the above technical solution, the composite material formed by EVA and DOPO at this mass ratio has a highly efficient flame retardant effect. The unique molecular structure of DOPO can form a dense carbon layer during combustion, effectively preventing the spread of flames. At the same time, EVA can also improve the compatibility of the composite material with other rubber components to a certain extent.

[0014] Preferably, the vinyl acetate content in the EVA is 28%.

[0015] By adopting the above technical solution, EVA with 28% vinyl acetate content has good flexibility and processing performance, can be better combined with DOPO, and in the sheath adhesive system, it helps to improve the overall flexibility, so that the sheath adhesive can maintain good performance under different temperature environments.

[0016] Preferably, the plasticizer includes at least one of chlorinated petroleum wax and halogenated phosphate ester.

[0017] By adopting the above technical scheme, chlorinated petroleum wax and halogenated phosphate ester not only have a good plasticizing effect, can reduce the viscosity of the rubber and improve the processing performance, but the halogenated phosphate ester also has a certain flame retardant effect, and synergizes with other flame retardants to further improve the flame retardant properties of the sheath rubber.

[0018] Preferably, the high-compression-resistant glass microbeads have a particle size of 1-3 μm and a compressive strength of 190 MPa.

[0019] By adopting the above technical scheme, high-compression glass microbeads with the same particle size and compressive strength can be evenly dispersed in the rubber material, which improves the compressive strength of the product. At the same time, due to their tiny particle size, they have little scattering effect on light, thereby effectively ensuring the light transmittance of the sheath glue.

[0020] Preferably, the acid absorbent is magnesium hydroxide.

[0021] By adopting the above technical solution, magnesium hydroxide decomposes at high temperature to absorb heat and play a flame retardant role. At the same time, it can effectively absorb acidic gases such as hydrogen chloride generated during the combustion process, reducing harm to the environment and human body. In addition, magnesium hydroxide is widely available and has a low cost.

[0022] Preferably, the transparent heat stabilizer is a composition of calcium stearate and organotin.

[0023] By adopting the above technical scheme, calcium stearate and the organotin composition work synergistically, which can not only effectively prevent thermal aging of rubber during processing and use, but also ensure the light transmittance of the product. Calcium stearate has a low cost and organotin has good thermal stability. The combination of the two can control costs while ensuring performance.

[0024] The present application also provides a method for preparing a light-transmitting highly flame-retardant rubber sheath adhesive, comprising the following steps:

[0025] Step 1: EVA and DOPO are put into the extruder in a mass ratio of 85:15, and the temperature from the first zone to the die is set at 100-170°C. After water cooling and granulation, the mixture enters the homogenization bin for drying to obtain a flame-retardant EVA composite material;

[0026] Step 2: Add the raw materials according to the above mass percentage into an internal mixer, control the temperature at 70°C and mix for 10 minutes to prepare a rubber compound;

[0027] Step 3: The mixed rubber is formed into 4 mm thin sheets through an open mill;

[0028] Step 4: vulcanize the extruded sheet into 1mm and 3mm test pieces through a flat plate;

[0029] Step 5: Test the mechanical properties, oxygen index, and light transmittance of the test piece;

[0030] Step 6: After the performance meets expectations, cable samples are made and subjected to bundled combustion tests.

[0031] In summary, the present application includes at least one of the following beneficial technical effects:

[0032] 1. Excellent comprehensive performance: With chloroether rubber and chlorinated polyethylene rubber as the main components, it provides good rubber elasticity and physical and mechanical properties. Among them, the ternary copolymer chloroether rubber has good chemical stability and oil resistance, regular molecular structure, and improves the comprehensive performance of the sheath rubber; the chlorinated polyethylene rubber with 40% chlorine content takes into account flame retardancy, flexibility and processing performance, and has good compatibility with other raw materials.

[0033] 2. Excellent flame retardant performance: The flame retardant EVA composite material gives the product excellent flame retardant performance. It is made of EVA and DOPO with a mass ratio of 85:15. When DOPO burns, it forms a dense carbon layer to prevent the spread of flames, and EVA improves compatibility with other rubber components.

[0034] 3. Good processing and flexibility: The plasticizer uses at least one of chlorinated petroleum wax and halogenated phosphate ester to reduce the viscosity of the rubber, improve the processing performance and flexibility, and the halogenated phosphate ester also synergizes with other flame retardants to improve the flame retardant properties.

[0035] 4. Balance between strength and light transmittance: Fumed silica enhances product strength and wear resistance; high-compression glass microbeads with a particle size of 1-3μm and a compressive strength of 190Mpa are evenly dispersed. While improving compressive strength, the tiny particle size has little effect on light scattering, thus ensuring light transmittance.

[0036] 5. Good stability: Coupling agents enhance the interfacial bonding of components and improve product stability; peroxides and cross-linking aids promote rubber cross-linking reactions, improve heat resistance and aging resistance; transparent heat stabilizers (calcium stearate and organic tin compositions) prevent thermal aging and ensure light transmittance, taking into account both performance and cost.

[0037] 6. Good environmental protection: The acid absorbent is made of magnesium hydroxide, which decomposes at high temperature and absorbs heat and is flame retardant. It absorbs the acid gas produced by combustion, reduces harm, and has a wide source and low cost. DETAILED DESCRIPTION

[0038] The present application is further described in detail below with reference to the embodiments.

[0039] Example 1

[0040] A light-transmitting highly flame-retardant rubber sheath adhesive of the present embodiment includes the following components in parts by weight: 20 parts of epichlorohydrin rubber, 60 parts of chlorinated polyethylene rubber, 20 parts of flame-retardant EVA composite material, 35 parts of chlorinated paraffin oil, 20 parts of fumed silica, 25 parts of high-compression glass microbeads, 0.5 parts of coupling agent KH550, 3 parts of calcium stearate, 1 part of methyl tin mercaptan, 15 parts of magnesium hydroxide, 10 parts of zinc borate, 3 parts of cross-linking aids DCP, and 3 parts of TAIC.

[0041] The preparation method of the flame-retardant EVA composite material in this embodiment is as follows: EVA and DOPO are put into the extruder at a mass ratio of 85:15, the temperature from the first zone to the die is set at 140°C, and after water cooling and granulation, the mixture enters the homogenization bin for drying to obtain a flame-retardant EVA composite material.

[0042] A method for preparing a light-transmitting highly flame-retardant rubber sheath adhesive in this embodiment comprises the following steps:

[0043] Step 1: Add the above raw materials into an internal mixer, control the temperature at 70°C and mix for 10 minutes to make a mixed rubber;

[0044] Step 2: The mixed rubber is formed into 4 mm thin sheets through an open mill;

[0045] Step 3: vulcanize the extruded sheet into 1mm and 3mm test pieces through a flat plate;

[0046] Step 4: Test the mechanical properties, oxygen index, and light transmittance of the test piece;

[0047] Step 5: After the performance meets expectations, cable samples are made and subjected to bundled combustion test.

[0048] Example 2

[0049] A light-transmitting highly flame-retardant rubber sheath adhesive of the present embodiment comprises the following components in parts by weight: 30 parts of chloroether rubber, 40 parts of chlorinated polyethylene, 30 parts of flame-retardant EVA composite material, 15 parts of chlorophosphate ester, 20 parts of chlorinated paraffin oil, 15 parts of fumed silica, 30 parts of high-compression glass microbeads, 0.5 parts of coupling agent KH5500, 4 parts of methyl tin mercaptide, 10 parts of magnesium hydroxide, 6 parts of zinc borate, 3 parts of cross-linking aid DCP, and 3 parts of TAIC.

[0050] The preparation method of the flame-retardant EVA composite material in this embodiment is as follows: EVA and DOPO are put into the extruder at a mass ratio of 85:15, the temperature from the first zone to the die is set at 140°C, and after water cooling and granulation, the mixture enters the homogenization bin for drying to obtain a flame-retardant EVA composite material.

[0051] A method for preparing a light-transmitting highly flame-retardant rubber sheath adhesive in this embodiment comprises the following steps:

[0052] Step 1: Add the above raw materials into an internal mixer, control the temperature at 70°C and mix for 10 minutes to make a mixed rubber;

[0053] Step 2: The mixed rubber is formed into 4 mm thin sheets through an open mill;

[0054] Step 3: vulcanize the extruded sheet into 1mm and 3mm test pieces through a flat plate;

[0055] Step 4: Test the mechanical properties, oxygen index, and light transmittance of the test piece;

[0056] Step 5: After the performance meets expectations, cable samples are made and subjected to bundled combustion test.

[0057] Example 3

[0058] A light-transmitting highly flame-retardant rubber sheath adhesive of the present embodiment includes the following components in parts by weight: 40 parts of chloroether rubber, 20 parts of chlorinated polyethylene, 40 parts of flame-retardant EVA composite material, 30 parts of chlorophosphate ester, 15 parts of fumed silica, 30 parts of high-compression glass microbeads, 0.5 parts of coupling agent KH550, 4 parts of methyl tin mercaptide, 5 parts of magnesium hydroxide, 4 parts of zinc borate, 3 parts of cross-linking aid DCP, and 3 parts of TAIC.

[0059] The preparation method of the flame-retardant EVA composite material in this embodiment is as follows: EVA and DOPO are put into the extruder at a mass ratio of 85:15, the temperature from the first zone to the die is set at 140°C, and after water cooling and granulation, the mixture enters the homogenization bin for drying to obtain a flame-retardant EVA composite material.

[0060] A method for preparing a light-transmitting highly flame-retardant rubber sheath adhesive in this embodiment comprises the following steps:

[0061] Step 1: Add the above raw materials into an internal mixer, control the temperature at 70°C and mix for 10 minutes to make a mixed rubber;

[0062] Step 2: The mixed rubber is formed into 4 mm thin sheets through an open mill;

[0063] Step 3: vulcanize the extruded sheet into 1mm and 3mm test pieces through a flat plate;

[0064] Step 4: Test the mechanical properties, oxygen index, and light transmittance of the test piece;

[0065] Step 5: After the performance meets expectations, cable samples are made and subjected to bundled combustion test.

[0066] Performance Testing

[0067] The relevant performance tests were carried out on the light-transmitting high flame-retardant rubber sheath adhesives prepared in Examples 1-3, and the results are listed in Table 1.

[0068] Table 1

[0069] Test items Example 1 Example 2 Example 3 Tensile strength / MPa 16.5 14.8 13.4 <![CDATA[Elongation at break / ％ > 389 406 487 Oxygen Index 38 36 33 Light Transmittance good good good

[0070] The products manufactured in this application have excellent physical and mechanical properties, the tensile strength can reach the standard requirement of mining cable of 11MPa or above, the oxygen index is above 27, and it has comprehensive properties such as light transmission and flame retardancy.

[0071] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A light-transmitting highly flame-retardant rubber sheath adhesive, characterized in that: The invention is prepared from the following raw materials in parts by weight: 20-40 parts of chloroether rubber, 20-60 parts of chlorinated polyethylene rubber, 20-40 parts of flame-retardant EVA composite material, 20-35 parts of plasticizer, 15-20 parts of fumed silica, 25-30 parts of high-pressure glass microbeads, 0.5-1 parts of coupling agent, 5-15 parts of acid absorbent, 4-10 parts of zinc borate, 3-4 parts of peroxide, 2-4 parts of cross-linking auxiliary agent and 3-4 parts of transparent heat stabilizer.

2. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The epichlorohydrin rubber is a ternary copolymer epichlorohydrin rubber.

3. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The chlorine content in the chlorinated polyethylene rubber is 40%.

4. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The flame retardant EVA composite material is made of the following raw materials: EVA and DOPO, and the mass ratio of EVA to DOPO is 85:

15.

5. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 4, characterized in that: The vinyl acetate content in the EVA is 28%.

6. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The plasticizer includes at least one of chlorinated petroleum wax and halogenated phosphoric acid ester.

7. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The high-compression glass microbeads have a particle size of 1-3 μm and a compressive strength of 190 MPa.

8. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The acid absorbent is magnesium hydroxide.

9. The light-transmitting highly flame-retardant rubber sheath adhesive according to claim 1, characterized in that: The transparent heat stabilizer is a composition of calcium stearate and organic tin.

10. A method for preparing the light-transmitting highly flame-retardant rubber sheath adhesive as claimed in any one of claims 1 to 9, characterized in that: The steps include: Step 1: EVA and DOPO are put into the extruder in a mass ratio of 85:15, and the temperature from the first zone to the die is set at 100-170°C. After water cooling and granulation, the mixture enters the homogenization bin for drying to obtain a flame-retardant EVA composite material; Step 2: Add the raw materials according to the above mass percentage into an internal mixer, control the temperature at 70°C and mix for 10 minutes to prepare a rubber compound; Step 3: The mixed rubber is formed into 4 mm thin sheets through an open mill; Step 4: vulcanize the extruded sheet into 1mm and 3mm test pieces through a flat plate; Step 5: Test the mechanical properties, oxygen index, and light transmittance of the test piece; Step 6: After the performance meets expectations, cable samples are made and subjected to bundled combustion tests.