CN114196190A

CN114196190A - TPU-PVC medical catheter and preparation method thereof

Info

Publication number: CN114196190A
Application number: CN202111584631.9A
Authority: CN
Inventors: 黄然; 徐沁
Original assignee: Zhongwei Medical Technology Jiangsu Co ltd
Current assignee: Zhongwei Medical Technology Jiangsu Co ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-03-18

Abstract

The invention discloses a TPU-PVC medical catheter and a preparation method thereof, wherein the catheter comprises the following components in parts by mass: 25-50% of diisocyanate, 20-70% of polyol, 1-10% of chain extender, 5-25% of PVC and 0-1% of catalyst, wherein the PVC component is distributed on the outer surface of the conduit and is matched with TPU to form a core-shell structure. The main TPU material has excellent mechanical performance, good processing flowability, high surface smoothness of the PVC outer layer, good chemical corrosion resistance and reduced cost, and can be widely used in various medical scenes.

Description

TPU-PVC medical catheter and preparation method thereof

Technical Field

The invention relates to a TPU-PVC medical catheter and a preparation method thereof, belonging to the field of medical high polymer materials and products.

Background

TPU materials have gradually replaced traditional plastics, such as PE, PVC, etc., due to their excellent processability, mechanical properties, and elasticity, and become one of the mainstream materials in the field of medical catheters. However, aiming at the special performance requirements of the medical catheter material, the modification and processing technology, the formula and the like of the TPU material are not as mature and reliable as the traditional high polymer material, and especially the important external surface performance in the medical catheter, such as easy processing, chemical corrosion resistance, surface smoothness and the like, has higher requirements on the modification technical means of the TPU material.

In terms of commercialization process, TPU catheter medical instruments need to be examined by a plurality of mandatory standards to form stable and reliable products step by step, and on the other hand, PVC has a long history of being used as medical catheters, medical grade PVC is nontoxic and odorless, has a smooth surface, good processing performance, chemical corrosion resistance, strong resistance to oxidizing agents, reducing agents and strong acids, and a formula process is mature and stable, so that the TPU catheter medical instruments are medical materials and medical instruments which are fully approved by a plurality of standards in China, European Union, America and the like. In addition, the price of the medical-mechanical grade PVC is obviously lower than that of TPU, and the cost advantage is achieved.

Therefore, the preparation of the medical catheter by mixing the TPU and the PVC together and combining the advantages of the TPU and the PVC is a technical scheme which is easy to think in the field. For example, utility model CN213822914U discloses an "infusion device", the infusion tube thereof includes a TPU lining and a PVC outer tube, the TPU lining is combined on the inner wall surface of the PVC outer tube. The utility model CN202516065U discloses a disposable blood extracorporeal circulation loop catheter, which adopts a double-layer tubular structure formed by compounding a TPU material inner layer and a PVC material outer layer which are manufactured by double-layer coextrusion. Utility model CN202010307U discloses a "double-deck compound bag formula transfusion system", used crowded fashioned polyvinyl chloride (PVC)/polyurethane (TPU) double-deck combined material altogether, the inlayer is the TPU material, and the skin is the PVC material. Similarly, patent CN109401715A discloses a "TPE/PVC double-layer conduit intermediate adhesive layer formula and pipe structure", and PVC/TPE double-layer pipes are prepared by using the intermediate adhesive layer.

The above solutions all adopt the technical means of independently making a tube from two materials, and then bonding and compounding, or double-layer co-extrusion and integral molding, which is also common in the art. However, the bonding method has more steps, more complex operation and low production efficiency, and in addition, a glue material needs to be introduced, so that the risk of medical non-compliance exists; the double-layer coextrusion equipment is expensive, needs special customization, cannot be commonly used with other conventional pipe-making equipment, and is poor in economical efficiency.

Disclosure of Invention

The object of the present invention is to solve a series of drawbacks of the background art.

In order to achieve the above object, the present invention provides a TPU-PVC medical catheter, comprising the following components:

further, the polyol is one or more of polyester polyol, polycaprolactone polyol, polycarbonate polyol, polybutadiene polyol and polytetramethylene ether glycol; the number average molecular weight of the polymer polyol is 1000-.

Further, the diisocyanate is one or more of toluene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate and isophorone diisocyanate.

Further, the chain extender is a small molecule diol containing 2 to 10 carbon atoms.

Further, the catalyst is an organobismuth catalyst.

Further, the PVC component is distributed primarily on the outer surface of the conduit.

Further, the content of the PVC component in the range of 0.5mm of the outer layer of the catheter accounts for more than 60 percent of the total weight of the catheter

In a second aspect, the invention provides a preparation method of a TPU-PVC medical catheter, which comprises the following steps:

(1) adding polyester polyol, diisocyanate and a chain extender into a reaction kettle, stirring for 30-60 minutes at the temperature of 85-105 ℃, and injecting into a single-screw extruder through a mixing and batching system; (2) simultaneously adding a catalyst into a feeding port of the single-screw extruder through a micro-injection pump; (3) adding a side-feed sleeve at section 2/3 of the number of sections of the sleeve combination of the single screw extruder, said section 2/3 being rounded to the value of the whole; (4) at the side-feeding feeder sleeve, the corresponding parts of PVC component were fed through a conical twin-screw unit.

Further, in the step (3), according to theoretical analysis and a large number of early-stage experiments, when the material is fed laterally, the material in the cylinder is fully plasticized, the fluidity is good, the material which is just fed needs to be plasticized for a certain time, and when the fluidity is poor, the material is concentrated on the outer side of the cylinder cavity due to the slow propelling speed, so that the material and the main material form a layering of a core-shell structure, after about 1/3 strokes, the lateral feeding is fully plasticized, a product with good molding is obtained by extrusion from the die head, the product is fully blended by early feeding, the core-shell structure disappears, and the PVC auxiliary material is not fully plasticized by late feeding, so that the extruded section is poor.

Specifically, if the number of the combined sections of the single screw extruder barrel is 8, 8 × 2/3 ≈ 5.33, and the four-way five-way integer is 5, namely, the side feeding barrel is arranged at the 5 th barrel of the single screw extruder.

Compared with the prior art, the invention has the beneficial effects that:

the prepared PVC composite TPU conduit is mainly characterized in that the outer surface accumulation of PVC components is realized through a tail end side material feeding means and a conical double-screw unit suitable for PVC processing, the PVC content in the outer layer of the conduit within 0.5mm accounts for more than 60% of the total weight of the conduit, and the main TPU material has excellent mechanical property, good processing flowability, high surface smoothness of the outer layer of the PVC, good chemical corrosion resistance and reduced cost, and can be widely used in various medical scenes. The integrated preparation of the TPU-PVC core-shell structure conduit is realized through universal equipment, wherein a single-screw extruder for processing the TPU and a conical double-screw extruder for processing the PVC part are both the universal equipment which can be independently used, and in the matched use of the invention, only limited transformation and installation of a section of sleeve are needed, so the cost is low.

Detailed Description

The present invention will now be described in further detail with reference to examples, but the present invention is not limited to the following examples, and any modifications made thereto will fall within the scope of the present invention.

Example 1:

a TPU-PVC medical catheter comprising the following components:

component name	Mass percent (%)
		Diisocyanate	40％
Polyhydric alcohols	50％
		Chain extender	5％
PVC	5％
		Catalyst and process for preparing same	0.5％

The extruded catheter was processed as follows: (1) adding polyester polyol, diisocyanate and a chain extender into a reaction kettle, stirring at 85 ℃ for 60 minutes, and injecting into a single-screw extruder through a mixing and batching system; (2) simultaneously adding a catalyst into a feeding port of the single-screw extruder through a micro-injection pump; (3) a6-sleeve single-screw extruder is selected, a side-feeding sleeve is adopted at the fourth sleeve, and PVC components with corresponding parts are fed through a conical double-screw unit.

The final extrusion molding pipe is measured, and the PVC content in the outer layer of the conduit within the thickness range of 0.5mm accounts for 65 +/-2 percent of the total weight.

Example 2:

a TPU-PVC medical catheter comprising the following components:

the extruded catheter was processed as follows: (1) adding polyester polyol, diisocyanate and a chain extender into a reaction kettle, stirring for 50 minutes at the temperature of 95 ℃, and injecting into a single-screw extruder through a mixing and batching system; (2) simultaneously adding a catalyst into a feeding port of the single-screw extruder through a micro-injection pump; (3) an 8-sleeve single-screw extruder is selected, a side feeding sleeve is adopted at the fifth sleeve, and PVC components with corresponding parts are fed through a conical double-screw unit.

The final extrusion molding pipe is measured, and the PVC content in the outer layer of the conduit within the thickness range of 0.5mm accounts for 80 +/-2 percent of the total weight.

Example 3:

a TPU-PVC medical catheter comprising the following components:

component name	Mass percent (%)
		Diisocyanate	40％
Polyhydric alcohols	30％
		Chain extender	5％
PVC	25％
		Catalyst and process for preparing same	0.5％

The extruded catheter was processed as follows: (1) adding polyester polyol, diisocyanate and a chain extender into a reaction kettle, stirring for 40 minutes at the temperature of 100 ℃, and injecting into a single-screw extruder through a mixing and batching system; (2) simultaneously adding a catalyst into a feeding port of the single-screw extruder through a micro-injection pump; (3) a12-sleeve single-screw extruder is selected, a side-feeding sleeve is adopted at the eighth sleeve, and PVC components with corresponding parts are fed through a conical double-screw unit.

The final extrusion molding pipe is measured, and the PVC content in the outer layer of the conduit within the thickness range of 0.5mm accounts for 95 +/-2 percent of the total weight.

The foregoing is considered as illustrative of the principles of the invention and is not intended to limit the invention in any way. The undescribed parts are by no means to be considered as having been known in the art, and any simple modifications, equivalent variations and modifications of the above examples, which are made in accordance with the technical spirit of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. The TPU-PVC medical catheter is characterized by comprising the following components:

the mass percentage of the components

25-50% of diisocyanate

20 to 70 percent of polyhydric alcohol

1 to 10 percent of chain extender

PVC 5-25%

0-1% of catalyst.

2. The TPU-PVC medical catheter of claim 1, wherein the polyol is one or more of five polymer polyols, polyester polyol, polycaprolactone polyol, polycarbonate polyol, polybutadiene polyol, and polytetramethylene ether glycol; the number average molecular weight of the polymer polyol is 1000-.

3. The TPU-PVC medical catheter of claim 1, wherein the diisocyanate is one or more of toluene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, and isophorone diisocyanate.

4. The TPU-PVC medical catheter of claim 1, wherein the chain extender is a small molecule diol having 2 to 10 carbon atoms.

5. The TPU-PVC medical catheter of claim 1, wherein the catalyst is an organobismuth catalyst.

6. The TPU-PVC medical catheter of any one of claims 1 to 6, wherein the PVC component is distributed predominantly on the outer surface of the catheter.

7. The TPU-PVC medical catheter of claim 6, wherein the PVC component is present in an amount of more than 60% of the total weight of the catheter sheath within a thickness of 0.5 mm.

8. A preparation method of a TPU-PVC medical catheter is characterized by comprising the following steps: adding polyester polyol, diisocyanate and a chain extender into a reaction kettle, stirring for 30-60 minutes at the temperature of 85-105 ℃, and injecting into a single-screw extruder through a mixing and batching system; (2) simultaneously adding a catalyst into a feeding port of the single-screw extruder through a micro-injection pump; (3) adding a side-feed sleeve at section 2/3 of the number of sections of the sleeve combination of the single screw extruder, said section 2/3 being rounded to the value of the whole; (4) at the side-feeding feeder sleeve, the corresponding parts of PVC component were fed through a conical twin-screw unit.

9. The method for preparing the TPU-PVC medical catheter of claim 8, wherein the number of the combined sections of the single screw extruder sleeve in step (3) is 6, and the side-feeding sleeve is arranged at the 4 th sleeve of the single screw extruder.