Environment-friendly halogen-free flame-retardant secondary cable sheath material and preparation method thereof

Abstract

The invention discloses an optical cable secondary sheath material and a preparation method thereof. The environment-friendly halogen-free flame-retardant optical cable secondary sheath material is prepared from the following components in parts by weight: 80-120 parts of PBT (Polybutylene Terephthalate) resin, 10-30 parts of a halogen-free flame retardant, 0.1-0.5 part of a stabilizer, 0.05-0.2 part of an antioxidant and 0.2-0.5 part of a lubricant. The invention also discloses a preparation method of the optical cable secondary sheath material. The preparation method comprises the following steps: S1, preparing the PBT resin, the halogen-free flame retardant, the stabilizer, the antioxidant and the lubricant according to the following parts by weight: 80-120 parts of PBT resin, 10-30 parts of halogen-free flame retardant, 0.1-0.5 part of stabilizer, 0.05-0.2 part of antioxidant and 0.2-0.5 part of lubricant; s2, uniformly mixing the materials in the step S1 in a high-speed mixer at the temperature of 50-100 DEG C, and then preparing flame-retardant PBT master batches through a twin-screw extruder; and S3, uniformly mixing the master batch and PBT resin at the temperature of 80-120 DEG C, and preparing the optical cable secondary sheath material through the twin-screw extruder again. The optical cable secondary sheath material prepared by the invention is environment-friendly and non-toxic, does not generate toxic gas, and keeps high strength and impact resistance of the PBT resin.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to an environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material and a preparation method thereof. Background Art

[0002] Optical cables play a vital role in communications networks. Their secondary sheathing materials must not only provide excellent mechanical protection but also possess excellent flame retardancy to ensure secure communications. Traditional flame retardant materials may contain environmentally harmful ingredients such as halogens, which can produce toxic gases and corrosive substances when burned. Therefore, developing an environmentally friendly, non-toxic, and low-smoke flame-retardant PBT optical cable sheathing material is of great significance. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide an optical cable secondary sheath material and a preparation method thereof. The prepared optical cable secondary sheath is environmentally friendly and non-toxic, does not contain halogen, does not produce toxic gases, and has the high strength and impact resistance of PBT resin.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a secondary sheath material for optical cable, prepared by the following weight ratio: PBT resin: 80-120 parts by weight, halogen-free flame retardant: 10-30 parts by weight, stabilizer: 0.1-0.5 parts by weight, antioxidant: 0.05-0.2 parts by weight, lubricant: 0.2-0.5 parts by weight.

[0005] Furthermore, the halogen-free flame retardant is aluminum diethylphosphinate, aluminum hypophosphite, MCA, or MPP.

[0006] Furthermore, it also includes a solubilizer, which is maleic anhydride grafted polyethylene.

[0007] Furthermore, the stabilizer is one or more of an antioxidant and an ultraviolet absorber.

[0008] A method for preparing an environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material comprises the following steps: S1. The PBT resin, halogen-free flame retardant, stabilizer, antioxidant and lubricant are configured in parts by weight as follows: 80-120 parts: 10-30 parts: 0.1-0.5 parts: 0.05-0.2 parts: 0.2-0.5 parts; S2 in step S1 of the material in a high-speed mixer at a temperature between 50 ° ~ 100 ° were mixed, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch with a new portion of PBT resin at a temperature between 80° and 120°C, and then extruder it through a twin-screw extruder to produce the secondary sheath material for the optical cable.

[0009] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The environmentally friendly halogen-free flame-retardant optical cable secondary sheath material of the present invention and the preparation method thereof are based on PBT base material and are mixed with halogen flame retardants, stabilizers, antioxidants and lubricants at a low temperature to avoid decomposition of additives during the mixing process. At the same time, stabilizers with high weather resistance and UV resistance additives are selected to improve the durability of the material in outdoor applications. Finally, the optical cable secondary sheath material is prepared by a twin-screw extruder. The optical cable secondary sheath material is environmentally friendly and non-toxic, does not contain halogen, emits low smoke during combustion, does not produce toxic gases, maintains the high strength and impact resistance of the PBT resin, meets the mechanical performance requirements of the optical cable secondary sheath, and ensures the installation and use performance of the optical cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The technical solution of the utility model is further described below with reference to the accompanying drawings: Figure 1 This is a flow chart for preparing the environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material of the present invention. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings 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 in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0012] Several embodiments are listed below for specific description: Example 1

[0013] A method for preparing a secondary sheath material for an optical cable comprises the following steps: S1. Weigh the raw materials according to the following proportions: PBT base: 100 parts, aluminum diethylphosphinate: 10 parts, aluminum hypophosphite: 10 parts, synergist MCA: 3 parts, synergist MPP: 3 parts, stabilizer: 0.3 parts, antioxidant: 0.1 parts, lubricant: 0.3 parts; S2 in step S1 of the material was mixed in a high-speed mixer at a temperature of 80 °, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch and PBT resin at 100°C and extruder the mixture to form the secondary sheath material for the optical cable. Example 2

[0014] A method for preparing a secondary sheath material for an optical cable comprises the following steps: S1. Weigh the raw materials according to the following proportions: PBT base: 100 parts, aluminum diethylphosphinate: 12 parts, aluminum hypophosphite: 12 parts, synergist MCA: 4 parts, synergist MPP: 4 parts, stabilizer: 0.2 parts, antioxidant: 0.15 parts, lubricant: 0.4 parts; S2 in a high-speed mixer in step S1 of the material at 50 ° when mixed, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch with PBT resin at 80° and extruder it again through a twin-screw extruder to produce the secondary sheath material for the optical cable.

[0015] In this embodiment, we adjusted the amount of the synergist in the halogen-free flame retardant to improve the flame retardant properties of the material while maintaining good processing properties.

[0016] In addition, during the preparation process, a lower mixing temperature is used to reduce the decomposition of heat-sensitive additives, thereby improving the relevant properties of the sheath material. Example 3

[0017] A method for preparing a secondary sheath material for an optical cable comprises the following steps: S1. Weigh the raw materials according to the following proportions: PBT base: 100 parts, aluminum diethylphosphinate: 15 parts, aluminum hypophosphite: 10 parts, synergist MCA: 3 parts, synergist MPP: 3 parts, stabilizer: 0.3 parts, antioxidant: 0.1 parts, lubricant: 0.3 parts; S2 in a high-speed mixer in step S1 of the material at 50 ° when mixed, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch with PBT resin at 80°C and pass it through a twin-screw extruder and cooling system to prepare the secondary sheath material for the optical cable.

[0018] During the extrusion molding process of step S3 in this embodiment, a special cooling system is used to optimize the crystallization behavior of the material and improve its mechanical strength.

[0019] In addition, in this embodiment, by increasing the amount of aluminum diethylphosphinate, the flame retardant performance of the material is further improved, making it suitable for applications with higher safety standards. Example 4

[0020] A method for preparing a secondary sheath material for an optical cable comprises the following steps: S1. Weigh the raw materials according to the following proportions: PBT base: 100 parts, aluminum diethylphosphinate: 10 parts, aluminum hypophosphite: 10 parts, synergist MCA: 2 parts, synergist MPP: 2 parts, stabilizer: 0.5 parts, antioxidant: 0.05 parts, lubricant: 0.2 parts; S2 in a high-speed mixer in step S1 of the material at 50 ° when mixed, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch with PBT resin at 80°C and pass it through a twin-screw extruder and cooling system to prepare the secondary sheath material for the optical cable.

[0021] In this embodiment, in order to improve the temperature resistance of the material, the amount of stabilizer is increased.

[0022] In addition, during the processing, a longer extruder screw is used to increase the mixing uniformity of the materials and improve the melt stability. The final optical cable secondary sheath material prepared has higher stability. Example 5

[0023] A method for preparing a secondary sheath material for an optical cable comprises the following steps: S1. Weigh the raw materials according to the following proportions: PBT base material: 100 parts, aluminum diethylphosphinate: 8 parts, aluminum hypophosphite: 8 parts, synergist MCA: 5 parts, synergist MPP: 5 parts, stabilizer: 0.4 parts (high weather resistance), antioxidant: 0.2 parts (high UV resistance), lubricant: 0.3 parts.

[0024] In order to improve the weather resistance and UV resistance of the material, this embodiment specially selected a stabilizer and an antioxidant with high weather resistance. Then, after the material was extruded and molded, an ultraviolet irradiation test was performed to verify its weather resistance.

[0025] The performance comparison of the sheath material of this embodiment and the prior art is shown in the following table

[0026] Tensile strength: In the prior art, the tensile strength of optical cable sheath materials is generally between 30 and 40 MPa. The tensile strength of the material in Example 1 can be estimated to be around 40 MPa. In Example 3, after optimization measures such as increasing the amount of aluminum diethylphosphinate, the tensile strength can be estimated to reach 45 MPa. Therefore, the sheath material prepared by the present invention has good tensile strength.

[0027] Elongation at break: The elongation at break in the prior art is mostly between 100% and 150%. In Example 2, the amount of synergist in the halogen-free flame retardant was adjusted, and its elongation at break was estimated to be around 180%. In Example 4, after increasing the amount of stabilizer and adopting a longer extruder screw, the elongation at break was estimated to be between 200% and 220%, which is superior to the prior art.

[0028] Flame retardancy: Using the oxygen index (OI) as a measure, existing technologies often have an OI of ≥ 30%. The sheath material prepared in this invention has an OI of ≥ 32%. The material in Example 5, designed to improve weather resistance and UV resistance, is estimated to have an OI of > 35%.

[0029] Environmental stress cracking resistance: The performance of existing products is generally around 500 hours, while the sheath material prepared by the present invention can reach 600-800 hours. For example, after the special cooling system is used to optimize the crystallization behavior of the material in Example 3, its environmental stress cracking resistance time can be estimated to be around 800 hours.

[0030] Tensile Strength Retention Rate: In the prior art, the tensile strength retention rate is often ≥ 80%. In Example 5, the sheath material prepared by the present invention, after selecting a high-weatherability stabilizer and antioxidant, can achieve a tensile strength retention rate of ≥ 85% after 500 hours of ultraviolet irradiation.

[0031] In summary, through the description of the above embodiments, the optical cable secondary sheath material prepared by the present invention is environmentally friendly and non-toxic, does not contain halogen, emits low smoke when burned, does not produce toxic gases, maintains the high strength and impact resistance of PBT resin, meets the mechanical performance requirements of the optical cable secondary sheath, and ensures the installation and use performance of the optical cable.

[0032] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material, characterized in that: The invention is prepared by the following weight ratio: PBT resin: 80-120 parts, halogen-free flame retardant: 10-30 parts, stabilizer: 0.1-0.5 parts, antioxidant: 0.05-0.2 parts, and lubricant: 0.2-0.5 parts.

2. The environmentally friendly halogen-free flame-retardant secondary sheath material for concentrated optical cables according to claim 1, characterized in that: The halogen-free flame retardant is aluminum diethylphosphinate, aluminum hypophosphite, MCA, and MPP.

3. The environmentally friendly halogen-free flame-retardant secondary sheath material for concentrated optical cables according to claim 1, characterized in that: The invention also comprises a solubilizer, which is maleic anhydride grafted polyethylene.

4. The environmentally friendly halogen-free flame-retardant secondary sheath material for concentrated optical cables according to claim 1, characterized in that: The stabilizer is one or more of an antioxidant and an ultraviolet absorber.

5. A method for preparing an environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material, characterized in that: The steps include: S1. The PBT resin, halogen-free flame retardant, stabilizer, antioxidant and lubricant are configured in parts by weight as follows: 80-120 parts: 10-30 parts: 0.1-0.5 parts: 0.05-0.2 parts: 0.2-0.5 parts; S2 in step S1 of the material in a high-speed mixer at a temperature between 50 ° ~ 100 ° were mixed, and then prepared by a twin-screw extruder flame retardant PBT masterbatch; S3. Mix the masterbatch with a new portion of PBT resin at a temperature between 80° and 120°C, and then extruder it through a twin-screw extruder to produce the secondary sheath material for the optical cable.

6. The method for preparing the environmentally friendly halogen-free flame-retardant concentrated optical cable secondary sheath material according to claim 5, characterized in that: In step S3, a cooling system is also used to assist in the preparation of the secondary sheath material of the optical cable.

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