A bend-resistant multi-fiber mpo connector and method of manufacture

Abstract

The present application relates to the technical fields of connector optical cable, and disclose a kind of bending-resistant multi-core MPO connector and preparation method, the MPO connector of the present application includes bending-resistant multi-core optical cable assembly and MPO connector;Bending-resistant multi-core optical cable assembly includes optical fiber, aramid yarn layer, inner protective layer, bending-resistant outer protective layer, braided layer;Polyvinyl chloride resin, chlorinated polyethylene grafted nitrile rubber, plasticizer, stabilizer, filler are mixed, to obtain bending-resistant outer protective layer;Chlorinated polyethylene molecular chain is introduced in the end of nitrile rubber, and the compatibility between polyvinyl chloride is better, and polyvinyl chloride is better toughened, the bending strength and impact strength are improved, and the tensile strength is also improved, so that the flexibility and bending resistance of sheath layer are better, to avoid the connection of connector connector and the cracking phenomenon of the connecting part of optical cable due to long-term bending.

Description

Technical Field

[0001] This invention relates to the field of connector and optical cable technology, specifically to a bend-resistant multi-core MPO connector and its manufacturing method. Background Technology

[0002] MPO connectors are multi-core fiber optic connectors commonly used as connectors for high-speed transmission standards. They are widely used in scenarios requiring high-speed, high-density fiber optic interconnection, such as data centers, 5G networks, and enterprise-level cabling. The optical cable portion of an MPO connector mainly consists of optical fibers, an inner sheath, and an outer sheath. The outer sheath is primarily made of materials such as polyvinyl chloride (PVC) and polyurethane, and mainly serves to provide protection against fire, water, and corrosion.

[0003] In practical use, the optical cable portion of the MPO connector is subjected to external forces and is in a state of long-term bending. If the outer sheath of the optical cable has poor toughness, the optical cable and the connector are prone to cracking and breakage, affecting the signal transmission performance of the MPO connector. Patent CN114249929B discloses a connector sheath made from nitrile rubber / polyvinyl chloride blend, fumed silica, plasticizer, antioxidant, etc., which has properties such as resistance to silicone oil, seawater corrosion, and ozone. However, this patent does not improve the impact strength, bending strength, and other properties of the polyvinyl chloride sheath, and its flexibility is poor. Summary of the Invention

[0004] (a) The technical problem solved by this invention is the poor flexibility and bending resistance of MPO connector optical cables.

[0005] (II) The technical solution of the present invention is: a bend-resistant multi-core MPO connector and its manufacturing method. The MPO connector is composed of a bend-resistant multi-core optical cable assembly and an MPO connector head. The bend-resistant multi-core optical cable assembly includes an optical fiber, an aramid yarn layer, an inner sheath, a bend-resistant outer sheath, and a braided layer. For example, the bend-resistant multi-core optical cable assembly, from the inside out, includes an optical fiber, an aramid yarn layer, an inner sheath, a bend-resistant outer sheath, and a braided layer.

[0006] The preparation method of the flexurally resistant outer sheath is as follows:

[0007] (1) Add hydroxyl-terminated butyronitrile rubber and sodium tert-butoxide solution to N,N-dimethylformamide, stir to activate, then add chlorinated polyethylene, stir to react, pour the solution into water, stir and let stand to separate the layers, separate and remove water and N,N-dimethylformamide, wash the product with water, dry, and obtain chlorinated polyethylene grafted butyronitrile rubber.

[0008] (2) Mix polyvinyl chloride resin, chlorinated polyethylene grafted nitrile rubber, plasticizer, stabilizer and filler in a mixer, and then mix and sheet in a two-roll mill to obtain a flexurally resistant outer protective layer.

[0009] Preferably, the inner protective layer is a cross-linked polyethylene layer.

[0010] Preferably, the woven layer is made of woven fibers, including polyester fibers or nylon fibers.

[0011] Preferably, (1) the mass ratio of intermediate hydroxyl-terminated nitrile rubber, sodium tert-butoxide, and chlorinated polyethylene is 100:(1.6-2.3):(4-10).

[0012] Preferably, in (1), the stirring activation is carried out at 40-60℃ for 1-2 hours.

[0013] Preferably, the stirring reaction in (1) is carried out at 40-60℃ for 12-18h.

[0014] Preferably, the temperature during mixing in (2) is 165-175℃ and the time is 7-10min.

[0015] Preferably, in (2), the mass ratio of polyvinyl chloride resin, chlorinated polyethylene grafted nitrile rubber, plasticizer, stabilizer and filler is 100:(10-30):(20-30):(2.4-3):(10-25).

[0016] Preferably, the stabilizer in (2) includes tribasic lead sulfate and dibasic lead phosphite.

[0017] Preferably, the plasticizer in (2) includes dioctyl phthalate.

[0018] Preferably, the filler in (2) includes calcium carbonate and zinc oxide.

[0019] Preferably, the outer sheath and braided layer of the optical cable can be crimped together using an adhesive to improve the pull-out force of the cable assembly, which is ≥150N. The adhesive includes epoxy resin and acrylic resin.

[0020] (III) Beneficial technical effects: This invention utilizes sodium tert-butoxide to activate the terminal hydroxyl groups of nitrile rubber to form an active sodium alkoxide structure (-ONa), which then undergoes an etherification reaction with the chlorine atoms of polyvinyl chloride to obtain chlorinated polyethylene grafted nitrile rubber. Finally, it is mixed with polyvinyl chloride, plasticizer, filler, etc., to obtain a bend-resistant outer sheath for multi-core MPO connectors. By introducing chlorinated polyethylene molecular chains with similar polarity and solubility parameters to polyvinyl chloride (PVC) at the ends of nitrile rubber, the compatibility between nitrile rubber and PVC is improved. As a highly elastic and tough rubber particle, nitrile rubber can induce crazes and shear bands through stress concentration when PVC is subjected to stress, thus terminating crack formation. Through the absorption and dissipation of energy by the elastic network molecular chains, it can better toughen PVC, improve bending strength and impact strength, and also enhance tensile strength. This improves the flexibility and bending resistance of the sheath layer, enabling the connector cable to withstand external impacts during normal use. It has excellent bending resistance and protection performance, preventing cracking of the connector head and the connection part of the optical cable due to long-term bending. This improves the structural stability of the connector cable, maintains the stability of efficient signal transmission, and is suitable for various application scenarios that require frequent movement and bending. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a bend-resistant multi-core optical cable assembly.

[0022] Figure 2 This is the infrared spectrum of chlorinated polyethylene grafted with nitrile butadiene rubber.

[0023] Figure 3 This is a structural diagram of a bend-resistant multi-core optical cable assembly containing adhesive. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: A bend-resistant multi-core MPO connector, comprising a bend-resistant multi-core optical cable assembly and an MPO connector; its structure is shown below. Figure 1 , Figure 1 The medium-bending-resistant multi-core optical cable assembly consists of optical fiber, aramid yarn layer, cross-linked polyethylene inner sheath, aramid yarn layer, bending-resistant outer sheath, and polyester fiber braided layer;

[0026] The preparation method of the flexurally resistant outer sheath is as follows:

[0027] (1) Add 1 kg of terminal hydroxyl-terminated butadiene-acrylonitrile rubber (model HTBN, Dongguan Mingyuan Plastics, the same below) and 250 mL of tert-butanol solution containing 18 g of sodium tert-butoxide to 5 L of N,N-dimethylformamide. Heat to 50 °C and stir to activate for 1 h. Then add 60 g of chlorinated polyethylene (model CPE-135A, Jiashan Sanyi New Materials, the same below) and stir to react for 18 h. Pour the solution into water, stir and let stand to separate the layers. Separate and remove water and N,N-dimethylformamide. Wash the product with water and dry to obtain chlorinated polyethylene grafted butadiene-acrylonitrile rubber. Figure 2 In the infrared spectrum, 2231 cm⁻¹ -1 The absorption peak of cyano-CN in nitrile rubber is 960 cm⁻¹. -1 It is the absorption peak of the olefinic C=C group of nitrile rubber, 3400 cm⁻¹ -1 The absence of hydroxyl absorption peaks on either side indicates that the hydroxyl groups in the nitrile rubber have reacted. (2927-2854 cm⁻¹) -1 It is a characteristic peak of the polyethylene molecular chain in chlorinated polyethylene.

[0028] (2) Mix 5 kg of polyvinyl chloride resin (model DG800, Suzhou Xinleda Plastics, the same below), 0.5 kg of chlorinated polyethylene grafted nitrile rubber, 1.5 kg of dioctyl phthalate, 95 g of tribasic lead sulfate, 45 g of dibasic lead phosphite, 0.4 kg of calcium carbonate and 0.1 kg of zinc oxide in a high-speed mixer for 20 min, and then mix them in a two-roll mill at 170°C for 8 min. Sheet the mixture to obtain a flexurally resistant outer protective layer.

[0029] Comparative Example 1: A multi-core MPO connector, comprising a multi-core optical cable assembly and an MPO connector; the multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, an outer sheath, and a polyester fiber braided layer;

[0030] The preparation method of the outer protective layer is as follows:

[0031] (1) Mix 5 kg of polyvinyl chloride resin, 0.5 kg of hydroxyl-terminated nitrile rubber, 1.5 kg of dioctyl phthalate, 95 g of tribasic lead sulfate, 45 g of dibasic lead phosphite, 0.4 kg of calcium carbonate, and 0.1 kg of zinc oxide in a high-speed mixer for 20 min, and then mix them in a two-roll mill at 170 °C for 8 min. Sheet the mixture to obtain the outer protective layer.

[0032] Comparative Example 2: A multi-core MPO connector, comprising a multi-core optical cable assembly and an MPO connector; the multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, an outer sheath, and a polyester fiber braided layer;

[0033] The preparation method of the outer protective layer is as follows:

[0034] (1) Mix 1 kg of hydroxyl-terminated nitrile rubber and 60 g of chlorinated polyethylene to obtain a chlorinated polyethylene-nitrile rubber blend.

[0035] (2) Mix 5 kg of polyvinyl chloride resin, 0.5 kg of chlorinated polyethylene-nitrile rubber blend, 1.5 kg of dioctyl phthalate, 95 g of tribasic lead sulfate, 45 g of dibasic lead phosphite, 0.4 kg of calcium carbonate and 0.1 kg of zinc oxide in a high-speed mixer for 20 min, and then mix them in a two-roll mill at 170 °C for 8 min. Sheet the mixture to obtain the outer protective layer.

[0036] Comparative Example 3: A multi-core MPO connector, comprising a multi-core optical cable assembly and an MPO connector; the multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, an outer sheath, and a polyester fiber braided layer;

[0037] The preparation method of the outer protective layer is as follows:

[0038] (1) Add 1 kg of terminal hydroxyl acrylonitrile rubber and 250 mL of tert-butanol solution containing 18 g of sodium tert-butoxide to 5 L of N,N-dimethylformamide, heat to 50 °C, stir for 1 h, then add 60 g of polyethylene resin, stir for 18 h, pour the solution into water, stir and let stand to separate the layers, separate and remove water and N,N-dimethylformamide, wash the product with water, dry, and obtain polyethylene-acrylonitrile rubber blend.

[0039] (2) Mix 5 kg of polyvinyl chloride resin, 0.5 kg of polyethylene-nitrile rubber blend, 1.5 kg of dioctyl phthalate, 95 g of tribasic lead sulfate, 45 g of dibasic lead phosphite, 0.4 kg of calcium carbonate and 0.1 kg of zinc oxide in a high-speed mixer for 20 min, and then mix them in a two-roll mill at 170 °C for 8 min. Sheet the mixture to obtain the outer protective layer.

[0040] Example 2: A bend-resistant multi-core MPO connector, comprising a bend-resistant multi-core optical cable assembly and an MPO connector; the bend-resistant multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, a bend-resistant outer sheath, and a polyester fiber braided layer;

[0041] The preparation method of the flexurally resistant outer sheath is as follows:

[0042] (1) Add 1 kg of terminal hydroxyl acrylonitrile rubber and 200 mL of tert-butanol solution containing 16 g of sodium tert-butoxide to 4 L of N,N-dimethylformamide. Heat to 40 °C and stir to activate for 2 h. Then add 40 g of chlorinated polyethylene and stir to react for 18 h. Pour the solution into water, stir and let stand to separate the layers. Separate and remove water and N,N-dimethylformamide. Wash the product with water and dry to obtain chlorinated polyethylene grafted acrylonitrile rubber.

[0043] (2) Mix 5 kg of polyvinyl chloride resin, 0.75 kg of chlorinated polyethylene grafted nitrile rubber, 1.4 kg of dioctyl phthalate, 90 g of tribasic lead sulfate, 40 g of dibasic lead phosphite, 1 kg of calcium carbonate and 0.1 kg of zinc oxide in a high-speed mixer for 30 min, and then mix them in a two-roll mill at 165 °C for 10 min. Sheet the mixture to obtain a flexurally resistant outer protective layer.

[0044] Example 3: A bend-resistant multi-core MPO connector, comprising a bend-resistant multi-core optical cable assembly and an MPO connector; the bend-resistant multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, a bend-resistant outer sheath, and a nylon fiber braided layer;

[0045] The preparation method of the flexurally resistant outer sheath is as follows:

[0046] (1) Add 1 kg of terminal hydroxyl acrylonitrile rubber and 300 mL of tert-butanol solution containing 23 g of sodium tert-butoxide to 6 L of N,N-dimethylformamide. Heat to 60 °C and stir to activate for 1 h. Then add 100 g of chlorinated polyethylene and stir to react for 12 h. Pour the solution into water, stir and let stand to separate the layers. Separate and remove water and N,N-dimethylformamide. Wash the product with water and dry to obtain chlorinated polyethylene grafted acrylonitrile rubber.

[0047] (2) Mix 5 kg of polyvinyl chloride resin, 1 kg of chlorinated polyethylene grafted nitrile rubber, 1.25 kg of dioctyl phthalate, 105 g of tribasic lead sulfate, 45 g of dibasic lead phosphite, 1.2 kg of calcium carbonate and 0.05 kg of zinc oxide in a high-speed mixer for 30 min, and then mix them in a two-roll mill at 175 °C for 7 min. Sheet the mixture to obtain a flexurally resistant outer protective layer.

[0048] Example 4: A bend-resistant multi-core MPO connector, comprising a bend-resistant multi-core optical cable assembly and an MPO connector; the bend-resistant multi-core optical cable assembly comprises an optical fiber, an aramid yarn layer, a cross-linked polyethylene inner sheath, an aramid yarn layer, a bend-resistant outer sheath, and a nylon fiber braided layer;

[0049] The preparation method of the flexurally resistant outer sheath is as follows:

[0050] (1) Add 1 kg of terminal hydroxyl acrylonitrile rubber and 250 mL of tert-butanol solution containing 18 g of sodium tert-butoxide to 5 L of N,N-dimethylformamide. Heat to 50 °C and stir to activate for 2 h. Then add 80 g of chlorinated polyethylene and stir to react for 18 h. Pour the solution into water, stir and let stand to separate the layers. Separate and remove water and N,N-dimethylformamide. Wash the product with water and dry to obtain chlorinated polyethylene grafted acrylonitrile rubber.

[0051] (2) Mix 5 kg of polyvinyl chloride resin, 1.25 kg of chlorinated polyethylene grafted nitrile rubber, 1.15 kg of dioctyl phthalate, 86 g of tribasic lead sulfate, 34 g of dibasic lead phosphite, 0.8 kg of calcium carbonate and 0.07 kg of zinc oxide in a high-speed mixer for 30 min, and then mix them in a two-roll mill at 170 °C for 7 min. Sheet the mixture to obtain a flexurally resistant outer protective layer.

[0052] Example 5: A bend-resistant multi-core MPO connector, comprising a bend-resistant multi-core optical cable assembly and an MPO connector; Figure 3 The medium-bending-resistant multi-core optical cable assembly consists of optical fiber, aramid yarn layer, cross-linked polyethylene inner sheath, aramid yarn layer, bending-resistant outer sheath, and nylon fiber braided layer; the outer sheath and braided layer of the optical cable are pressed together with epoxy resin adhesive to improve the pull-out force of the cable assembly.

[0053] The preparation method of the flexurally resistant outer sheath is as follows:

[0054] (1) Add 1 kg of terminal hydroxyl acrylonitrile rubber and 250 mL of tert-butanol solution containing 20 g of sodium tert-butoxide to 5 L of N,N-dimethylformamide. Heat to 60 °C and stir to activate for 2 h. Then add 70 g of chlorinated polyethylene and stir to react for 18 h. Pour the solution into water, stir and let stand to separate the layers. Separate and remove water and N,N-dimethylformamide. Wash the product with water and dry to obtain chlorinated polyethylene grafted acrylonitrile rubber.

[0055] (2) Mix 5 kg of polyvinyl chloride resin, 1.5 kg of chlorinated polyethylene grafted nitrile rubber, 1 kg of dioctyl phthalate, 80 g of tribasic lead sulfate, 38 g of dibasic lead phosphite, 0.9 kg of calcium carbonate and 0.1 kg of zinc oxide in a high-speed mixer for 30 min, and then mix them in a two-roll mill at 170 °C for 8 min. Sheet the mixture to obtain a flexurally resistant outer protective layer.

[0056] The outer protective layer was hot-pressed in a flat vulcanizing machine at 170℃ and 10MPa pressure to form test specimens. Bending strength was tested according to GB / T 9341-2008 standard. Cantilever beam impact strength was tested according to GB / T 1843-2008 standard. Tensile strength was tested according to GB / T 1040.1-2025 standard.

[0057] Table 1 Performance Tests

[0058]

[0059] Compared to Comparative Example 1, Example 1 utilizes chlorinated polyethylene to graft-modify hydroxyl-butadiene nitrile rubber (NBR). Chlorinated polyethylene molecular chains are introduced into the end positions of the NBR. Chlorinated polyethylene has similar polarity and solubility parameters to polyvinyl chloride (PVC), thus improving the compatibility between NBR and PVC. As a highly elastic and tough rubber particle, NBR induces crazes and shear bands through stress concentration when PVC is subjected to stress, terminating crack formation. Through the absorption and dissipation of energy via its elastic network molecular chains, it provides better toughening to PVC, improving flexural strength, impact strength, and tensile strength, thereby enhancing the flexibility and bending resistance of the sheath layer. Examples 2-5, by adjusting the proportions of each component, also prepared outer sheaths with high impact strength, flexural strength, and toughness.

[0060] Comparative Example 2 involved the physical blending of hydroxyl-terminated nitrile butadiene rubber and chlorinated polyethylene. No reaction occurred between the two, and the chlorinated polyethylene did not improve the compatibility between nitrile butadiene rubber and polyvinyl chloride. The toughening effect of nitrile butadiene rubber was poor, and the impact strength and flexural strength of the polyvinyl chloride outer sheath were low.

[0061] The polyethylene in Comparative Example 3 does not contain chlorine atoms and cannot react with the terminal hydroxyl groups of nitrile rubber, making it difficult to improve the compatibility between nitrile rubber and polyvinyl chloride. The toughening effect of nitrile rubber is poor, and the impact strength and flexural strength of the polyvinyl chloride outer sheath are low.

[0062] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A method for manufacturing a bend-resistant multi-core MPO connector, characterized in that, The MPO connector includes a bend-resistant multi-core optical cable assembly and an MPO connector head; The bend-resistant multi-core optical cable assembly includes an optical fiber, an aramid yarn layer, an inner sheath, a bend-resistant outer sheath, and a braided layer. The method for preparing the flexurally resistant outer sheath includes: mixing polyvinyl chloride resin, chlorinated polyethylene grafted nitrile rubber, plasticizer, stabilizer, and filler in a mixer, and then mixing and sheeting the mixture in a two-roll mill to obtain the flexurally resistant outer sheath. The mass ratio of the polyvinyl chloride resin, chlorinated polyethylene grafted nitrile rubber, plasticizer, stabilizer, and filler is 100:(10-30):(20-30):(2.4-3):(10-25).

2. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The inner protective layer is a cross-linked polyethylene layer; the woven layer is made of woven fibers, including polyester fibers or nylon fibers.

3. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The flexural outer sheath and the woven layer are bonded together using an adhesive.

4. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The mixing temperature is 165-175℃ and the time is 7-10 minutes.

5. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The stabilizer is one or more of tribasic lead sulfate and dibasic lead phosphite; the plasticizer is dioctyl phthalate.

6. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The filler is one or more of calcium carbonate and zinc oxide.

7. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 1, characterized in that, The preparation method of the chlorinated polyethylene grafted nitrile rubber is as follows: add hydroxyl-terminated nitrile rubber and a tert-butanol solution of sodium tert-butoxide to N,N-dimethylformamide, heat to 40-60℃, stir and activate for 1-2 hours, then add chlorinated polyethylene, stir and react for 12-18 hours, pour the solution into water, stir and let stand to separate the layers, wash the product after separation, and dry to obtain chlorinated polyethylene grafted nitrile rubber.

8. The method for manufacturing a bend-resistant multi-core MPO connector according to claim 7, characterized in that, The mass ratio of the terminal hydroxyl-terminated nitrile rubber, sodium tert-butoxide, and chlorinated polyethylene is 100:(1.6-2.3):(4-10).

9. A bend-resistant multi-core MPO connector obtained by the preparation method according to any one of claims 1-8.

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