Sheath layer for thin-diameter ultrasonic transmission cable based on compressed conductor and application of sheath layer

Abstract

The invention provides a sheath layer for a thinned ultrasonic transmission cable based on a compressed conductor and application of the sheath layer. The sheath layer is prepared from the following components in parts by weight: 80 to 100 parts of polyvinyl chloride, 30 to 50 parts of acrylate copolymer, 0.5 to 2 parts of diphenol propane, 1 to 3 parts of N-isopropyl-N '-phenyl p-phenylenediamine, 5 to 10 parts of calcium-zinc stabilizer, 5 to 15 parts of low-temperature-resistant modifier and 0.5 to 2 parts of lubricant. The sheath layer prepared by the invention has relatively high tensile strength, elongation at break and antibacterial rate, has no crack or damage after low-temperature test, is high in durability and reliability, good in antibacterial property and strong in environmental adaptability, and can still keep flexibility at low temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of medical cables, and particularly relates to a sheath layer for a fine-diameter ultrasonic transmission cable based on a compressed conductor and application thereof. BACKGROUND

[0002] With the development of medical technology towards "minimally invasive and fine", the core needs of clinical ultrasonic transmission cables gradually focus on fine-diameter, high reliability, strong environmental adaptability and antibacterial property. For example, endoscopic ultrasonic equipment needs to integrate the cable into an endoscopic probe with a diameter of less than 10 mm. An excessively large cable outer diameter not only increases the pain of patient cavity insertion, but also limits the freedom of the doctor's operation. Since the cable is almost inevitably dragged, wound, and even directly contacted with the wound, mucosa or catheter during diagnosis and treatment, if bacteria breed on the surface of the cable, the infection risk will be magnified, and the cable may also face low-temperature cold chain transportation or extreme environment emergency use in medical treatment, which puts forward strict requirements on the mechanical properties, low-temperature resistance and antibacterial property of the cable.

[0003] However, the existing ultrasonic transmission cable still has many defects in the technical aspect, and it is difficult to meet the above high-end needs. For example, in terms of the performance of the sheath layer, the existing cable sheath is mostly based on ordinary polyvinyl chloride as the base material, and phthalate plasticizers are often added to improve the toughness. Such plasticizers are easy to migrate with the use time, resulting in the tensile strength of the sheath layer decaying to below 18 MPa, and the sheath layer is prone to cracking in frequent bending operations. In addition, phthalate substances have potential environmental risks. In addition, the traditional sheath layer lacks low-temperature resistance design. In the environment below-40 DEG C or the low-temperature plasma disinfection process, the material is easy to be brittle and broken, and cannot adapt to the cold chain transportation or emergency medical scenes in the northern cold regions. Moreover, the existing sheath layer mostly realizes the bacteriostatic function by surface spraying of antibacterial agents, but the coating is easy to fall off, the bacteriostatic rate decreases, and it is difficult to meet the long-term use of medical and health standards.

[0004] Therefore, it is a technical problem to be solved in the field to develop a fine-diameter ultrasonic transmission cable with reasonable design, excellent sheath layer performance and reliable signal transmission. SUMMARY

[0005] The purpose of the present application is to provide a sheath layer for a fine-diameter ultrasonic transmission cable based on a compressed conductor to solve the problems raised in the background.

[0006] In order to achieve the above-mentioned purpose, the present application provides a kind of sheath layer for the ultrasonic transmission cable based on the compression conductor thinning, its characterized in that, the preparation raw material of sheath layer includes the following weight parts of components: polyvinyl chloride 80-100 parts, acrylate copolymer 30-50 parts, diphenyl propane 0.5-2 parts, N-isopropyl-N'-phenyl-p-phenylenediamine 1-3 parts, calcium zinc stabilizer 5-10 parts, low temperature resistance modifier 5-15 parts, lubricant 0.5-2 parts.

[0007] As a further improvement, the acrylate copolymer is prepared from methyl methacrylate, isooctyl acrylate and allyl dimethyl hydantoin.

[0008] As a further improvement, the preparation of the acrylate copolymer includes the following steps: (1) 5,5-dimethyl hydantoin is added to an alkaline solution, then methanol, 3-bromo-1-propylene is added under stirring, and then heated and stirred in a water bath at 50-60°C for reaction, after reaction, post-treatment is performed to obtain allyl dimethyl hydantoin; (2) methyl methacrylate and isooctyl acrylate are added to a flask, then organic solvent and initiator are added, heated and stirred for 5-10h under nitrogen atmosphere, after reaction, cooled to room temperature, post-treatment is performed to obtain acrylate copolymer.

[0009] As a further improvement, the CAS number of 5,5-dimethyl hydantoin is 77-71-4.

[0010] As a further improvement, the mass ratio of methyl methacrylate, isooctyl acrylate and allyl dimethyl hydantoin is 1:1.5-3:1-2.

[0011] The acrylate copolymer has good compatibility with polyvinyl chloride, and can improve the plasticity of polyvinyl chloride to a certain extent, but the improvement effect of conventional acrylate copolymer is single, the present application synthesizes allyl dimethyl hydantoin from 5,5-dimethyl hydantoin, and then copolymerizes with methyl methacrylate and isooctyl acrylate to obtain acrylate copolymer, which can not only improve the mechanical properties and weather resistance of polyvinyl chloride, but also make the prepared sheath layer have high flexibility and high reliability, and the sheath layer also has good antibacterial property due to the addition of allyl dimethyl hydantoin, which meets the high standard medical and health requirements.

[0012] As a further improvement, the low temperature resistance modifier is ethylene-vinyl acetate carbonyl copolymer.

[0013] As a further improvement, the lubricant is at least one of sodium stearate, magnesium stearate, paraffin and polyethylene wax.

[0014] Preferably, the lubricant is a polyethylene wax.

[0015] As a further improvement, the application of a sheath layer to a compressed conductor-based slimline ultrasound transmission cable, characterized in that the compressed conductor-based ultrasound transmission cable comprises a composite core unit, a shielding layer and a sheath layer arranged in order from the inside to the outside.

[0016] As a further improvement, the composite core unit is composed of a plurality of image transmission lines, a plurality of power supply lines and a plurality of control lines; the image transmission line is twisted by a metal filament conductor, then compressed to obtain an ultra-fine coaxial line, and finally coated with an insulation layer to obtain the image transmission line.

[0017] As a further improvement, the diameter of the ultra-fine coaxial line is 0.050-0.060mm; the ultra-fine coaxial line is a 43AWG low-capacitance ultra-fine coaxial line; the capacitance value is ≤58pF.

[0018] As a further improvement, the metal filament conductor is a high-purity oxygen-free copper wire or a silver-plated silver copper alloy wire.

[0019] As a further improvement, the shielding layer is a silver-plated copper wire braid structure or a tin-plated copper wire braid structure.

[0020] As a further improvement, the insulation layer of the ultra-fine coaxial line uses a fusible polytetrafluoroethylene material.

[0021] As a further improvement, the preparation method of the compressed conductor-based slimline ultrasound transmission cable comprises the following steps: (1) Image transmission line preparation: the metal filament conductor is twisted and then compressed to form an ultra-fine coaxial line; an insulation layer is coated outside the ultra-fine coaxial line, cooled and shaped to obtain the image transmission line; (2) Composite core unit preparation: a plurality of image transmission lines, a plurality of power supply lines and a plurality of control lines are twisted to form a composite core unit; (3) Shielding layer preparation: a shielding layer is braided outside the composite core unit to obtain a composite shielding layer; (4) Sheath layer preparation: the raw materials for preparing the sheath layer are blended and extruded outside the composite shielding layer to obtain the compressed conductor-based slimline ultrasound transmission cable.

[0022] As a further improvement, the composite core unit is composed of 193 image transmission lines, 4 power supply lines and 4 control lines.

[0023] As a further improvement, the outer diameter of the composite core wire unit is 3.0-4.0 mm; the thickness of the shielding layer is 0.15-0.30 mm; the thickness of the sheath layer is 0.5-1.2 mm; and the overall outer diameter of the ultrasonic transmission cable can be controlled to be ≤8.2 mm.

[0024] Compared with the prior art, the present application has the following advantages: The present application provides a fine-diameter ultrasonic transmission cable based on compressed conductors. The acrylate copolymer is prepared from methyl methacrylate, isooctyl acrylate and allyl dimethyl hydantoin. The use of diphenyl propane and low-temperature resistant modifiers can improve the mechanical properties and weather resistance of polyvinyl chloride, so that the prepared sheath layer has high tensile strength, elongation at break and antibacterial rate, and no cracks or damage after low-temperature testing, indicating that the mechanical properties are good, the durability and reliability are high, the antibacterial property is good, the high-standard medical and health requirements can be met, and the flexibility can be maintained at low temperature, and the environmental adaptability is strong. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic diagram of the cross section of the image transmission line. DETAILED DESCRIPTION

[0026] The present application will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the present application and are used to illustrate the present application, but are not used to limit the present application. Other combinations and various modifications within the concept of the present application can be made without departing from the spirit or scope of the present application.

[0027] In the following examples, the compound monomers and related reagents used except for the acrylate copolymer can be purchased from the market, wherein the fusible polytetrafluoroethylene is purchased from Dongguan Heye Plastic Co., Ltd., model 420; the ethylene-vinyl acetate carbonyl copolymer is purchased from Ningbo Huwangcheng Plastic Co., Ltd., model 4924; the polyvinyl chloride is purchased from Dongguan Hongjexing Plastic Co., Ltd., brand S-65; the calcium-zinc stabilizer is purchased from Jinan Xiangfengweiye Chemical Co., Ltd.; the polyethylene wax is purchased from Wuhan Xindongyi Chemical Co., Ltd., model 400PE; and the ethylene-propylene-diene rubber is purchased from Shanghai Ousuo Plastic Co., Ltd., model 3722P.

[0028] Example 1 The preparation of the acrylate copolymer A comprises the following steps: (1) 12.8 g of 5,5-dimethylhydantoin was added to a mixture of 5.6 g of potassium hydroxide and 50 mL of water; then 20 mL of methanol and 8.8 mL of 3-bromo-1-propylene were continuously added under stirring; then the reaction was stirred in a 60°C constant temperature water bath for 2 h, and after the reaction was completed, the crude product was dried under reduced pressure at 50°C, and recrystallized with petroleum ether to obtain allyl dimethyl hydantoin; (2) 25 g of methyl methacrylate, 46 g of isooctyl acrylate, 42 g of allyl dimethyl hydantoin were added to a flask, followed by 600 mL of toluene and 0.38 g of azobisisobutyronitrile, and the reaction was stirred at 75°C under a nitrogen atmosphere for 5 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and then poured into a large amount of methanol to precipitate the product. The solid was collected by filtration, dissolved in toluene, and then precipitated in methanol. This operation was repeated twice. The obtained solid was dried in a vacuum oven to obtain an acrylate copolymer A.

[0029] Preparation of the sheath layer: A sheath layer for a compressed conductor-based miniaturized ultrasonic transmission cable was obtained by blending and extruding polyvinyl chloride 100 parts, acrylate copolymer A 45 parts, diphenylolpropane 1 part, N-isopropyl-N'-phenyl-p-phenylenediamine 1 part, calcium-zinc stabilizer 8 parts, ethylene-vinyl acetate copolymer 6 parts, and polyethylene wax 1 part using a screw extruder with a screw temperature of 150°C for the feeding section, 165°C for the compression section, 175°C for the homogenization section, and 185°C for the die head, and a screw rotation speed of 25 rpm, followed by cooling and setting.

[0030] Example 2 Preparation of the acrylate copolymer A: same as in Example 1.

[0031] Sheath layer for a compressed conductor-based miniaturized ultrasonic transmission cable: The sheath layer was prepared using the same method as in Example 1, except that the raw materials were polyvinyl chloride 90 parts, acrylate copolymer A 50 parts, diphenylolpropane 0.7 parts, N-isopropyl-N'-phenyl-p-phenylenediamine 1.3 parts, calcium-zinc stabilizer 5 parts, ethylene-vinyl acetate copolymer 8 parts, and polyethylene wax 0.8 parts.

[0032] Example 3 Preparation of the acrylate copolymer B, comprising the following steps: (1) 12.8 g of 5,5-dimethylhydantoin was added to a mixture of 5.6 g of potassium hydroxide and 45 mL of water, followed by the addition of 22 mL of methanol and 8.8 mL of 3-bromo-1-propene under stirring. The reaction was then stirred in a 60°C constant temperature water bath for 2 h. After the reaction was completed, the product was dried under reduced pressure at 50°C, and then recrystallized from petroleum ether to obtain allyl dimethyl hydantoin. (2) 45 g of methyl methacrylate, 64 g of isooctyl acrylate, and 42 g of allyl dimethyl hydantoin were added to a flask, followed by the addition of 700 mL of toluene and 0.28 g of azobisisobutyronitrile, and the reaction was stirred at 75°C under a nitrogen atmosphere for 6 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and then poured into a large amount of methanol to precipitate the solid. The solid was collected by filtration, dissolved in toluene, and then precipitated in methanol. This operation was repeated twice, and the obtained solid was dried in a vacuum oven to obtain an acrylate copolymer B.

[0033] Sheath layer for a compressed conductor-based thin diameter ultrasonic transmission cable: The sheath layer was prepared in substantially the same manner as in Example 1, except that the acrylate copolymer A was replaced with the acrylate copolymer B.

[0034] Example 4 Preparation of the acrylate copolymer A: same as in Example 1.

[0035] Preparation of a sheath layer for a compressed conductor-based thin diameter ultrasonic transmission cable: The sheath layer was prepared in substantially the same manner as in Example 1, except that 8 parts of the ethylene-vinyl acetate carbonyl copolymer was replaced with 8 parts of the ternary ethylene-propylene rubber.

[0036] Comparative Example 1 Preparation of the acrylate copolymer C, including the following steps: 25 g of methyl methacrylate and 46 g of isooctyl acrylate were added to a flask, followed by the addition of 600 mL of toluene and 0.38 g of azobisisobutyronitrile, and the reaction was stirred at 75°C under a nitrogen atmosphere for 5 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and then poured into a large amount of methanol to precipitate the solid. The solid was collected by filtration, dissolved in toluene, and then precipitated in methanol. This operation was repeated twice, and the obtained solid was dried in a vacuum oven to obtain an acrylate copolymer C.

[0037] Preparation of a compressed conductor-based thin diameter ultrasonic transmission cable: The sheath layer was prepared in substantially the same manner as in Example 1, except that the acrylate copolymer A was replaced with the acrylate copolymer C.

[0038] Comparative Example 2 The sheath layer was prepared in substantially the same manner as in Example 1, except that the acrylate copolymer was replaced with dioctyl phthalate.

[0039] Three samples were cut from the sheath layer of the ultrasonic transmission cable prepared in Examples 1 to 4 and Comparative Examples 1 and 2, and tests for tensile strength, low temperature resistance, and antibacterial properties were performed, according to the following test methods. Tensile strength, elongation at break: dumbbell test pieces with a thickness of 2 mm were prepared according to the method in GB / T 2951.11-2008 "Cables and optical cables - Insulation and sheaths - General test methods - Part 11: General test methods - Measurement of thickness and outer dimensions - Mechanical property tests", and tensile strength and elongation at break were tested; Low temperature resistance: the sample was fixed in a low temperature test chamber, and was decreased to 77K (-196℃) at a rate of 5℃ / min, and was kept for 2h; during the keeping, the sample was reciprocally bent 10 times by a special fixture (bending angle ±90°, bending radius 4mm); after the keeping, the sample was naturally warmed to 25℃, and whether there was crack or damage on the surface and cross section of the sample was observed; Antibacterial property: the test was carried out according to the test method 1 film pasting method in GB 21551.2-2010, and the detected bacteria was Escherichia coli, and the antibacterial rate was measured.

[0040] The measured results are shown in Table 1: Table 1

[0041] As can be seen from the test results of Example 1 and Comparative Examples 1-2 in Table 1, compared with the acrylate copolymer prepared by using methyl methacrylate and isooctyl acrylate or the sheath layer of the transmission cable prepared by using a conventional plasticizer (dioctyl phthalate) instead of the acrylate copolymer, the sheath layer of the ultrasonic transmission cable prepared by using the acrylate copolymer prepared by using methyl methacrylate, isooctyl acrylate and allyl dimethyl hydantoin in the present application has higher tensile strength, elongation at break and antibacterial rate, and has no crack or damage after low temperature test, which indicates that the mechanical property is good, the durability and reliability are high, the antibacterial property is good, the high standard medical and health requirements can be met, and the flexibility can be maintained at low temperature, and the environmental adaptability is strong.

[0042] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor, characterized in that, The raw materials for preparing the sheath layer include the following components in parts by weight: 80-100 parts of polyvinyl chloride, 30-50 parts of acrylate copolymer, 0.5-2 parts of bisphenol A propane, 1-3 parts of N-isopropyl-N'-phenyl-p-phenylenediamine, 5-10 parts of calcium-zinc stabilizer, 5-15 parts of low-temperature modifier, and 0.5-2 parts of lubricant.

2. The sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor according to claim 1, characterized in that, The acrylate copolymer is prepared by reacting methyl methacrylate, isooctyl acrylate, and allyl dimethylhydantoin.

3. The sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor according to claim 1, characterized in that, The preparation of the acrylate copolymer includes the following steps: (1) 5,5-dimethylhydantoin was added to an alkaline solution, and then methanol and 3-bromo-1-propene were added under stirring. The reaction was then heated and stirred in a water bath at 50-60°C until the reaction was completed. After post-treatment, allyl dimethylhydantoin was obtained. (2) Methyl methacrylate, isooctyl acrylate, and allyl dimethylhydantoin were added to a flask, followed by the addition of an organic solvent and an initiator. The mixture was heated and stirred under a nitrogen atmosphere for 5-10 hours. After the reaction was completed, the mixture was cooled to room temperature and then post-treated to obtain an acrylate copolymer.

4. The sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor according to claim 2, characterized in that, The mass ratio of methyl methacrylate, isooctyl acrylate, and allyl dimethylhydantoin added is 1:1.5-3:1-2.

5. The sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor according to claim 1, characterized in that, The low-temperature resistant modifier is an ethylene-vinyl acetate carbonyl copolymer.

6. The sheath layer for a narrow-diameter ultrasonic transmission cable based on a compressed conductor according to claim 1, characterized in that, The lubricant is at least one of sodium stearate, magnesium stearate, paraffin wax, and polyethylene wax.

7. The application of the sheath layer for a compressed conductor-based slim ultrasonic transmission cable according to any one of claims 1-6 in a compressed conductor-based slim ultrasonic transmission cable, characterized in that, The ultrasonic transmission cable based on compressed conductors comprises a composite core wire unit, a shielding layer, and a sheath layer arranged sequentially from the inside out.

8. The reduced-diameter ultrasonic transmission cable based on a compressed conductor according to claim 7, characterized in that, The composite core wire unit is composed of multiple image transmission lines, multiple power lines and multiple control lines; the image transmission lines are made by twisting together fine metal conductors and then compressing them to obtain ultra-fine coaxial cables, and finally extruding an insulating layer to obtain the image transmission lines.

9. The reduced-diameter ultrasonic transmission cable based on a compressed conductor according to claim 8, characterized in that, The metal filament conductor is a high-purity oxygen-free copper wire or a silver-plated copper-silver alloy wire.

10. The reduced-diameter ultrasonic transmission cable based on a compressed conductor according to claim 7, characterized in that, The shielding layer is a silver-plated copper wire braided structure or a tin-plated copper wire braided structure.

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