Flame-retardant polypropylene connecting wire sheath layer material and manufacturing method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a flame-retardant polypropylene connecting wire sheath layer material and a manufacturing method thereof.According to the connecting wire sheath layer material, polypropylene serves as a matrix, synergistic flame retardance is achieved on a condensed phase and a gas phase by adding a composite flame retardant, the flame retardance of the connecting wire sheath layer material is improved, and the flame retardance of the connecting wire sheath layer material is improved. When a fire disaster occurs, fire spreading can be prevented, and losses caused by the fire disaster are reduced; by adding the wear-resistant additive, the wear resistance of the polypropylene matrix is improved, external force wear and scraping in the long-term use process can be effectively resisted, the internal structure of the connecting line is protected, the service life of the connecting line is further prolonged, and potential safety hazards caused by wear of a sheath layer material of the connecting line are reduced; the connecting wire sheath layer material prepared by the invention has excellent flame retardance and wear resistance, the safety is greatly improved, and the application prospect is wide.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a flame-retardant polypropylene connecting wire sheath layer material and a manufacturing method thereof. Background Art

[0002] Connecting wires play an important role between systems, components and devices, achieving energy transfer, signal transmission and electrical connection, ensuring overall normal operation and function realization, and also playing an important role in data management and equipment maintenance. Therefore, they are widely used in home appliances, communication equipment, transportation, energy and industry. The sheath layer of the connecting wire is the physical protection layer of the connecting wire, which ensures the safety of the connecting wire and makes the connecting wire adaptable to different application scenarios. It has an insulating effect to prevent fire caused by leakage and short circuit, as well as a beautifying effect, which is convenient for maintenance and management. Common materials used for the sheath layer of the connecting wire are: polyvinyl chloride (PVC), chlorinated polyethylene (CPE), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyurethane (PUR), etc. Polypropylene has excellent heat resistance, cold resistance, acid and alkali resistance, corrosion resistance, excellent electrical insulation performance, light weight, easy processing, installation and transportation, environmental protection, low cost, and can be used as the material for the sheath layer of the connecting wire.

[0003] During daily use, connecting wires are often moved, bent, folded, and stretched. Poor wear resistance may cause damage to the sheath layer of the connecting wire, shorten the service life of the connecting wire, expose internal wires and other structures, increase signal interference, and thus affect the quality and stability of signal transmission, deteriorate insulation, increase the risk of electric shock, and expose The wires are prone to short circuits or leakage, generate a large amount of heat energy and electric sparks, and are very likely to cause fires; common technical means generally improve the flame retardancy and wear resistance of the sheath layer material of the connecting wire by adding flame retardants and inorganic materials, but small molecule flame retardants are easily precipitated and some halogen flame retardants will release toxic gases and smoke; inorganic materials have limited improvement in wear resistance, and the dispersibility of untreated inorganic materials in the polymer matrix is ​​poor; therefore, the present invention prepares flame retardants and wear retardants, adds them to the sheath layer material of the connecting wire, improves the wear resistance and flame retardancy of the sheath layer material of the connecting wire, improves safety, and extends the service life of the connecting wire. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the object of the present invention is to provide a flame retardant polypropylene connecting wire sheath layer material and a manufacturing method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A flame-retardant polypropylene connecting wire sheath layer material comprises the following raw materials in parts by weight: 80-100 parts of polypropylene, 2-5 parts of composite flame retardant, 3-6 parts of wear-resistant additive, 0.5-2.5 parts of antioxidant, 0.5-2 parts of lubricant, and 0.5-1.5 parts of cross-linking agent.

[0007] Furthermore, the preparation method of the composite flame retardant comprises the following steps:

[0008] Step A, dispersing the pretreated shell powder in N,N-dimethylformamide to form a uniform suspension, adding chloroacetic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, stirring at room temperature for 5-8 hours, filtering, washing, and vacuum drying to obtain modified shell powder;

[0009] Step B: Add the modified shell powder to dimethyl sulfoxide and stir evenly, then introduce nitrogen, add diethyl hydroxymethylphosphonate and an alkaline catalyst, heat to 60-80° C., react for 4-6 hours, filter, wash, and dry at 55-65° C. for 1-2 hours to obtain a composite flame retardant.

[0010] By adopting the above technical scheme, the shell powder is chemically modified with chloroacetic acid to obtain modified shell powder with grafted chlorine substituents. Under the action of an alkaline catalyst, the active chlorine substituents in the modified shell powder structure react with the hydroxyl group in diethyl hydroxymethylphosphonate to obtain a composite flame retardant.

[0011] Furthermore, in step A, the pretreatment method of the shell powder is: soak the 3-10 μm shell powder in 95% ethanol solution, heat it to 60-70°C, ultrasonically disperse it for 20-40 minutes, filter it, and vacuum dry it.

[0012] Furthermore, in step B, the alkaline catalyst is sodium carbonate or potassium carbonate.

[0013] Furthermore, the preparation method of the wear-resistant additive comprises the following steps:

[0014] Step 1: Add nano zirconium oxide to N,N-dimethylformamide and disperse evenly, introduce nitrogen, add 3-isocyanatobenzoyl chloride and pyridine, stir and react at 30-45°C for 4-6h, filter, wash and vacuum dry to obtain modified nano zirconium oxide;

[0015] Step 2: Add the modified nano-zirconium oxide into xylene and stir evenly, then introduce nitrogen, heat to 70-80° C., add liquid hydroxy-terminated styrene-butadiene rubber and catalyst, react for 4-6 hours, filter, wash, and vacuum dry to obtain a wear-resistant additive.

[0016] By adopting the above technical scheme, 3-isocyanatobenzoyl chloride is used to chemically modify nano zirconium oxide to obtain modified nano zirconium oxide grafted with isocyanate groups. Under the action of a catalyst, the isocyanate groups in the modified nano zirconium oxide structure can undergo an amination reaction with the active hydroxyl groups in the liquid hydroxy-terminated styrene-butadiene rubber to obtain a wear-resistant additive.

[0017] Furthermore, in step 2, the average molecular weight of the liquid hydroxy-terminated styrene-butadiene rubber is 2500.

[0018] Furthermore, in step 2, the catalyst is stannous octoate or dibutyltin dilaurate.

[0019] Furthermore, the antioxidant is antioxidant 1010 and antioxidant 168; the lubricant is any one of polyethylene wax, zinc stearate or magnesium stearate; the cross-linking agent is any one of diisopropyl peroxide, di-tert-butyl peroxide or tert-butyl peroxide laurate.

[0020] A method for making a flame-retardant polypropylene connecting wire sheath layer material comprises the following steps:

[0021] S1. Add parts by weight of polypropylene, composite flame retardant, wear-resistant additive, antioxidant, lubricant and cross-linking agent into a high-speed mixer, set the speed to 800-1000r / min, stir and mix for 5-10min to obtain a mixed base material;

[0022] S2. Add the mixed base material into a twin-screw extruder, perform melt extrusion, and cool and granulate to obtain a connecting wire sheath layer material.

[0023] Furthermore, in S2, the melt extrusion temperature is 180-220°C, and the screw speed is 200-350r / min.

[0024] Beneficial effects of the present invention:

[0025] (1) The present invention prepares shell powder grafted with phosphorus-containing flame retardant as a composite flame retardant. After the shell powder is organically modified by the phosphorus-containing flame retardant, the precipitation problem of small molecule phosphorus-containing flame retardant is effectively avoided, and the compatibility with the polypropylene matrix is ​​effectively improved, avoiding the agglomeration problem; at the same time, the phosphorus element can absorb the heat released during combustion to dehydrate and generate a carbon layer. The shell powder is non-flammable, and the high-temperature decomposition produces carbon dioxide which can reduce the concentration of combustible and combustion-supporting gases. Therefore, the two can be superimposed on each other under the action of condensed phase and gas phase flame retardancy to exert a synergistic flame retardant effect, thereby improving the flame retardant properties of the polypropylene matrix, thereby improving the flame retardant properties of the connecting wire sheath layer material, improving the safety of the connecting wire, preventing the spread of fire when a fire occurs, slowing down the combustion rate, and reducing losses.

[0026] (2) The present invention prepares nano zirconium oxide grafted with styrene-butadiene rubber as a wear-resistant additive. On the one hand, the nano zirconium oxide has high hardness and wear resistance, and can effectively resist external wear and scratches during use; on the other hand, the grafting of styrene-butadiene rubber with nano zirconium oxide can make the nano zirconium oxide more dispersed in the polypropylene matrix, thereby improving the wear resistance of the polypropylene matrix. At the same time, styrene-butadiene rubber has good wear resistance. After chemically bonding with the nano zirconium oxide, the two work synergistically to improve the wear resistance of the polypropylene matrix. In addition, the wear-resistant additive can also form a cross-linked structure with the polypropylene matrix under the action of the cross-linking agent, and the molecular structure is more compact, thereby further improving the wear resistance of the connecting wire sheath layer material and extending the service life of the connecting wire.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 is an infrared spectrum of the composite flame retardant prepared in an embodiment of the present invention;

[0030] Figure 2 This is an infrared spectrum of the wear-resistant additive prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] 1. Preparation of composite flame retardant

[0034] Step A, soaking 5 μm shell powder in 95% ethanol solution, heating to 65° C., ultrasonically dispersing for 30 minutes, filtering, and vacuum drying to obtain pretreated shell powder;

[0035] Step B, dispersing 3.2 g of pretreated shell powder in N,N-dimethylformamide to form a uniform suspension, adding 2 g of chloroacetic acid, 0.8 g of dicyclohexylcarbodiimide and 0.4 g of 4-dimethylaminopyridine, stirring at room temperature for 6 h, filtering, washing, and vacuum drying to obtain modified shell powder;

[0036] Step C: add 2.8 g of modified shell powder to dimethyl sulfoxide and stir evenly, then introduce nitrogen, add 1.6 g of diethyl hydroxymethylphosphonate and 0.8 g of sodium carbonate, heat to 70°C, react for 5 h, filter, wash, and dry at 60°C for 1 h to obtain a composite flame retardant.

[0037] The composite flame retardant and potassium bromide were mixed and ground into sheets, and tested using a Fourier transform infrared spectrometer. Figure 1 As shown, the spectral wavenumber test range is 4000cm -1 -500cm -1 , analysis shows that in the infrared spectrum of the composite flame retardant, 2938cm -1 The absorption peak of CH in methylene appears at 1726 cm -1 The absorption peak of C=O in the ester group appears at 1500cm -1 CO3 appears 2- The absorption peak is 1220cm -1 The absorption peak of P=O in the phosphate group appears at 1108cm -1 The absorption peak of the carbon-oxygen single bond in the ether bond appears at .

[0038] 2. Preparation of wear-resistant additives

[0039] Step 1: Add 4 g of nano zirconium oxide to N,N-dimethylformamide and disperse evenly, then introduce nitrogen, add 2.5 g of 3-isocyanatobenzoyl chloride and 0.2 g of pyridine, stir at 40°C for 5 h, filter, wash, and vacuum dry to obtain modified nano zirconium oxide;

[0040] Step 2: Add 3 g of modified nano-zirconium oxide to xylene and stir evenly, then introduce nitrogen, heat to 75°C, add 1.2 g of liquid hydroxy-terminated styrene-butadiene rubber with an average molecular weight of 2500 and 0.1 g of dibutyltin dilaurate, react for 6 hours, filter, wash, and vacuum dry to obtain a wear-resistant additive.

[0041] The wear-resistant additive was mixed with potassium bromide and ground into a sheet, and then tested using a Fourier infrared spectrometer. Figure 2 As shown, the spectral wavenumber test range is 4000cm -1 -500cm -1 , analysis shows that in the infrared spectrum of wear-resistant additives, 3078cm -1 and 3046cm-1 The absorption peak of CH in the benzene ring appears at 3024 cm -1 The absorption peak of the CH bond in the carbon-carbon double bond of styrene-butadiene rubber appears at 1708 cm -1 The absorption peak of carbamate carbonyl C=O appears at 1582 cm -1 The absorption peak of COO-Zr appears at 1540 cm -1 The absorption peak of NH in aminomethyl ester appears at 650cm -1 The absorption peak of Zr-O-Zr appears at

[0042] 3. Preparation of the sheath material of the connecting wire

[0043] S1, 80g polypropylene, 2g composite flame retardant, 3g wear-resistant additive, 0.3g antioxidant 1010, 0.2g antioxidant 168, 0.5g polyethylene wax and 0.5g di-tert-butyl peroxide were added into a high-speed mixer, the speed was set to 800r / min, and the mixture was stirred for 5min to obtain a mixed base material;

[0044] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 180° C., with a screw speed of 200 r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0045] Example 2

[0046] Preparation of connecting wire sheath material

[0047] S1, 90g of polypropylene, 3.5g of the composite flame retardant prepared in Example 1, 4.5g of the wear-resistant additive prepared in Example 1, 1g of antioxidant 1010, 0.5g of antioxidant 168, 1g of polyethylene wax and 1g of di-tert-butyl peroxide were added to a high-speed mixer, the speed was set to 900r / min, and the mixture was stirred and mixed for 8min to obtain a mixed base material;

[0048] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 200°C, with a screw speed of 250r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0049] Example 3

[0050] Preparation of connecting wire sheath material

[0051] S1. Add 100 g of polypropylene, 5 g of the composite flame retardant prepared in Example 1, 6 g of the wear-resistant additive prepared in Example 1, 1.5 g of antioxidant 1010, 1 g of antioxidant 168, 2 g of polyethylene wax and 1.5 g of di-tert-butyl peroxide into a high-speed mixer, set the speed to 1000 r / min, stir and mix for 10 min to obtain a mixed base material;

[0052] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 220° C., and the screw speed is 350 r / min. After cooling and granulation, the connecting wire sheath layer material is obtained.

[0053] Comparative Example 1

[0054] Preparation of connecting wire sheath material

[0055] S1, adding 90g polypropylene, 3.5g composite flame retardant prepared in Example 1, 1g antioxidant 1010, 0.5g antioxidant 168, 1g polyethylene wax and 1g di-tert-butyl peroxide into a high-speed mixer, setting the speed to 900r / min, stirring and mixing for 8min to obtain a mixed base material;

[0056] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 200°C, with a screw speed of 250r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0057] Comparative Example 2

[0058] Preparation of connecting wire sheath material

[0059] S1, adding 90g of polypropylene, 4.5g of the wear-resistant additive prepared in Example 1, 1g of antioxidant 1010, 0.5g of antioxidant 168, 1g of polyethylene wax and 1g of di-tert-butyl peroxide into a high-speed mixer, setting the speed to 900r / min, stirring and mixing for 8min to obtain a mixed base material;

[0060] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 200°C, with a screw speed of 250r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0061] Comparative Example 3

[0062] Preparation of connecting wire sheath material

[0063] S1, 90g of polypropylene, 3.5g of shell powder, 4.5g of the wear-resistant additive prepared in Example 1, 1g of antioxidant 1010, 0.5g of antioxidant 168, 1g of polyethylene wax and 1g of di-tert-butyl peroxide were added to a high-speed mixer, the speed was set to 900r / min, and the mixture was stirred and mixed for 8min to obtain a mixed base;

[0064] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 200°C, with a screw speed of 250r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0065] Comparative Example 4

[0066] Preparation of connecting wire sheath material

[0067] S1, adding 90g polypropylene, 3.5g composite flame retardant prepared in Example 1, 4.5g nano zirconium oxide, 1g antioxidant 1010, 0.5g antioxidant 168, 1g polyethylene wax and 1g di-tert-butyl peroxide into a high-speed mixer, setting the speed to 900r / min, stirring and mixing for 8min to obtain a mixed base material;

[0068] S2. Add the mixed base material into a twin-screw extruder, melt extrude at 200°C, with a screw speed of 250r / min, and obtain the connecting wire sheath layer material after cooling and granulation.

[0069] Performance Testing

[0070] The connecting wire sheath layer materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were tested:

[0071] The connecting wire sheath layer materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were prepared into samples that met the test standards. The limiting oxygen index of the samples was tested according to the standard GB / T 2406.2-2009, and the wear resistance of the samples was tested according to the standard GB / T5478-2008. The specific test results are shown in the following table:

[0072] Oxygen index / % Wear rate / % Example 1 33.4 0.15 Example 2 33.9 0.12 Example 3 33.6 0.14 Comparative Example 1 32.8 1.56 Comparative Example 2 21.5 0.21 Comparative Example 3 27.3 0.19 Comparative Example 4 33.1 0.63

[0073] As can be seen from the above table, the connecting wire sheath layer materials prepared in Examples 1 to 3 have excellent flame retardant and wear resistance. Comparative Example 1 does not add wear-resistant additives, and cannot use nano zirconium oxide grafted styrene butadiene rubber to synergistically improve wear resistance and cross-link with the polypropylene matrix to further improve wear resistance, so the wear rate test result is poor; Comparative Example 2 does not add a composite flame retardant, and cannot use shell powder grafted phosphorus-containing flame retardant to synergistically flame retardant in the condensed phase and gas phase, so the oxygen index test result is poor; Comparative Example 3 adds shell powder and wear-resistant additives, and the shell powder has certain flame retardancy, but the flame retardant effect of the phosphorus-containing flame retardant in the condensed phase cannot be used, and the shell powder is not modified and directly added to the matrix, which is easy to agglomerate, affecting the flame retardant performance, so the oxygen index test result is poor; Comparative Example 4 adds nano zirconium oxide and composite flame retardant, and the nano zirconium oxide has wear resistance but is directly added to the polypropylene matrix, resulting in agglomeration problems, and cannot synergistically improve wear resistance with styrene butadiene rubber, and cannot be cross-linked with the polypropylene matrix to further improve wear resistance, so the wear rate test result is poor.

[0074] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A flame retardant polypropylene connecting wire sheath material, characterized in that: The invention comprises the following raw materials in parts by weight: 80-100 parts of polypropylene, 2-5 parts of composite flame retardant, 3-6 parts of wear-resistant additive, 0.5-2.5 parts of antioxidant, 0.5-2 parts of lubricant and 0.5-1.5 parts of cross-linking agent.

2. The flame-retardant polypropylene connecting wire sheath material according to claim 1, characterized in that: The preparation method of the composite flame retardant comprises the following steps: Step A, dispersing the pretreated shell powder in N,N-dimethylformamide to form a uniform suspension, adding chloroacetic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, stirring at room temperature for 5-8 hours, filtering, washing, and vacuum drying to obtain modified shell powder; Step B: Add the modified shell powder to dimethyl sulfoxide and stir evenly, then introduce nitrogen, add diethyl hydroxymethylphosphonate and an alkaline catalyst, heat to 60-80° C., react for 4-6 hours, filter, wash, and dry at 55-65° C. for 1-2 hours to obtain a composite flame retardant.

3. The flame-retardant polypropylene connecting wire sheath material according to claim 2, characterized in that: In step A, the pretreatment method of the shell powder is: soak the 3-10 μm shell powder in 95% ethanol solution, heat it to 60-70° C., ultrasonically disperse it for 20-40 minutes, filter it, and vacuum dry it.

4. The flame-retardant polypropylene connecting wire sheath material according to claim 2, characterized in that: In step B, the alkaline catalyst is sodium carbonate or potassium carbonate.

5. The flame-retardant polypropylene connecting wire sheath material according to claim 1, characterized in that: The preparation method of the wear-resistant additive comprises the following steps: Step 1: Add nano zirconium oxide to N,N-dimethylformamide and disperse evenly, introduce nitrogen, add 3-isocyanatobenzoyl chloride and pyridine, stir and react at 30-45°C for 4-6h, filter, wash and vacuum dry to obtain modified nano zirconium oxide; Step 2: Add the modified nano-zirconium oxide into xylene and stir evenly, then introduce nitrogen, heat to 70-80° C., add liquid hydroxy-terminated styrene-butadiene rubber and catalyst, react for 4-6 hours, filter, wash, and vacuum dry to obtain a wear-resistant additive.

6. The flame-retardant polypropylene connecting wire sheath material according to claim 5, characterized in that: In step 2, the average molecular weight of the liquid hydroxy-terminated styrene-butadiene rubber is 2500.

7. The flame-retardant polypropylene connecting wire sheath material according to claim 5, characterized in that: In step 2, the catalyst is stannous octoate or dibutyltin dilaurate.

8. The flame-retardant polypropylene connecting wire sheath material according to claim 1, characterized in that: The antioxidants are antioxidant 1010 and antioxidant 168; the lubricant is any one of polyethylene wax, zinc stearate or magnesium stearate; and the cross-linking agent is any one of diisophenylpropene peroxide, di-tert-butyl peroxide or tert-butyl peroxide laurate.

9. A method for manufacturing the flame-retardant polypropylene connecting wire sheath layer material as claimed in claim 1, characterized in that: The following steps are involved: S1. Add parts by weight of polypropylene, composite flame retardant, wear-resistant additive, antioxidant, lubricant and cross-linking agent into a high-speed mixer, set the speed to 800-1000r / min, stir and mix for 5-10min to obtain a mixed base material; S2. Add the mixed base material into a twin-screw extruder, perform melt extrusion, and cool and granulate to obtain a connecting wire sheath layer material.

10. The method for manufacturing a flame-retardant polypropylene connecting wire sheath layer material according to claim 9, characterized in that: In S2, the melt extrusion temperature is 180-220°C, and the screw speed is 200-350r / min.

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