CN109942867B - Preparation method of polytetrafluoroethylene tube colored tape coating and polytetrafluoroethylene tube - Google Patents

Abstract

The invention discloses a preparation method of a polytetrafluoroethylene tube ribbon coating and a polytetrafluoroethylene tube thereof, wherein a modified coating material is manufactured, the surface of the tube is treated, and an annular ribbon identification coating is added on the polytetrafluoroethylene tube, so that the navigation and positioning of medical staff in endoscope medical treatment can be improved.

Description

Preparation method of polytetrafluoroethylene tube colored tape coating and polytetrafluoroethylene tube

Technical Field

The invention relates to the technical field of polytetrafluoroethylene material coatings, in particular to a preparation method of a color band coating of a medical polytetrafluoroethylene tube and a polytetrafluoroethylene tube thereof.

Background

Polytetra fluoro ethylene (PTFE for short) has extraordinary hydrophobic and self-cleaning properties, i.e. hydrophobic and hydrophobic properties. And the paint has temperature resistance, solvent resistance and stable chemical property. The material was originally commercialized by dupont and is commonly known as teflon, and is often made into a non-stick coating for pan, tube wall, or other cookware for use as an interior or exterior surface treatment for the vessel.

Polytetrafluoroethylene is applied to many conventional medical instruments such as infusion tubes, rod-shaped/bottle-shaped base materials, gas-liquid valves, protective clothing and the like in the medical field by virtue of outstanding non-stick property. Meanwhile, the polytetrafluoroethylene tube is often applied to various catheters of endoscopes. Although such medical tubing has good stain resistance, it also has a significant limitation in applications requiring labeling.

Because, during endoscopic medical procedures, especially minimally invasive surgery with the aid of an endoscope, the time and scope of visualization is extremely limited, for example endoscopic retrograde cholangiopancreatography (ERCP procedure). The monitoring or attending physician needs to accurately locate the internal tissue via the reference markers of the vessel wall or other object to facilitate efficient navigation of the tool. However, it is difficult to directly add a coating layer to a polytetrafluoroethylene-based polymer pipe for marking in the prior art.

In the prior art, a white polytetrafluoroethylene pipe with a longitudinal color band is prepared by a method of directly adding a color master batch into a polytetrafluoroethylene dispersing material and filling and molding step by step. However, the tube forming process is complicated, and in order to ensure the longitudinal rigidity and the bending strength, the method can only prepare the white polytetrafluoroethylene tube with the longitudinal color band, and the tube is non-transparent and cannot accurately calibrate the longitudinal position, particularly the depth, of the endoscope medical treatment.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a preparation method of a polytetrafluoroethylene tube ribbon coating, which is used for manufacturing a modified coating material and processing the surface of a tube.

A preparation method of a polytetrafluoroethylene tube color band coating comprises the following steps: preparing and treating a polytetrafluoroethylene tube body; secondly, modifying color ribbon pigment; thirdly, coating color ribbon pigment on the outer wall of the tube body; and fourthly, curing the color band coating.

Further, in the step I, the preparation method of the polytetrafluoroethylene tube body comprises the steps of uniformly mixing and curing the polytetrafluoroethylene dispersing material and the auxiliary agent, extruding the polytetrafluoroethylene paste material, and molding and sintering the extruded polytetrafluoroethylene paste material. The mould pressing sintering process step preferably comprises the steps of extruding the polytetrafluoroethylene paste into a pipe mould, compacting and forming by a press, and sintering by a sintering furnace at the temperature of (360-380 ℃), wherein the auxiliary agent is preferably (70-200) petroleum solvent oil, and more preferably kerosene or gasoline.

Further, in the step I, the polytetrafluoroethylene tube body processing method comprises acid etching surface treatment and plasma surface treatment.

The acid etching surface treatment method is preferably that the polyvinyl chloride pipe body is placed into an acid etching tank, oscillation acid etching treatment is carried out for 3min, 50% ethanol water solution is cleaned, and the cleaning agent is dried for standby; the treatment solution in the acid etching tank is a hydrochloric acid-hydrofluoric acid mixed solution containing 5 wt% of HCl and 1 wt% of HF.

The plasma surface treatment method is preferably that a, the polyvinyl chloride pipe body is placed into a plasma sputtering instrument, b, a sputtering cavity is vacuumized to 0.1-0.5 mbar, inert gas is filled to the vacuum degree of 1-2 mbar, c, a hot cathode is powered and heated to form plasma, a metal target surface is bombarded, and d, the plasma and sputtered metal atoms are cooperatively treated on the surface of the pipe body. The metal target surface metal is preferably an iron, copper, silver or gold target, more preferably an iron or copper target.

The plasma surface treatment is preferably: the vacuum degree of the cavity (1-2) mbar, and the distance between the surface of the polymer film and the metal target is 40 mm.

Further, in the step II, the water-based pigment is dissolved by using a solvent, tannic acid and an acidic stabilizer are added, and the mixture is uniformly mixed to obtain the modified color ribbon pigment, wherein the addition amount of the tannic acid is (1-5) wt%. The water-based pigment is preferably a conventional medical acid water-based pigment, and comprises at least one of hematoxylin, carmine, acid fuchsin, methyl blue, fast green and eosin, and is preferably methyl blue or fast green. The addition of tannic acid alone tends to cause flocculation of the aqueous pigment and therefore the addition of a suitable acidic stabilizer is necessary. Preferably, the solvent is water and/or ethanol, the acidic stabilizer is acetic acid, hydrochloric acid or citric acid, and the pH value of the modified color band pigment is preferably 3-5.

Further, in the third step, the method for coating the color of the color ribbon includes a cover-die spraying method, a ring printing method, and a dip printing method.

The ring printing method is preferably: immersing the inner wall of the annular brush head into the modified color ribbon pigment, feeding the polytetrafluoroethylene tube into the annular brush head, attaching the bristles in the annular brush head to the outer wall of the tube body, performing rotary coating, and then feeding the polytetrafluoroethylene tube out. The annular printing equipment has simple structure and higher production efficiency. However, the annular printing method is inevitably affected by the annular brush head, and the regularity of the edge of the ink ribbon coating, the uniformity of the thickness of the coating and the irregularity of the edge of the ink ribbon cannot be effectively ensured in the rotary printing process.

Further preferably, in the third step, the method for coating the color ribbon pigment is a cover-die spraying method, and the process steps preferably include: after the surface activity treatment is carried out on the area to be coated of the polytetrafluoroethylene tube, the rest area is covered by a mold, only the surface gap of the area to be coated is reserved, a spray gun is used for spraying the polytetrafluoroethylene tube wrapped by the mold, and then the mold is removed. The edge regularity of the color band can be obviously improved by adopting the optimal coating process. For surgical medicine, especially for endoscopic-assisted medicine, where the operating space is limited, slight differences in position can lead to significant increases in medical risk, for example, adjacent to the aorta/main veins or the great nerves. The good regularity of the color band obtained by the process is the guarantee of accurate calibration of the position. Preferably, the covering mould is made by resin hole injection molding or forging metal pipe punching.

Further, in the step IV, the polytetrafluoroethylene tube coated with the color ribbon pigment is placed into a heating device for drying and curing for 10-30 min, wherein the curing temperature is 250-.

The polytetrafluoroethylene tube with the color band coating prepared by the preparation method comprises a tube body and at least one color band coating, wherein the color band coating at least partially covers the outer wall of the tube body; and the ribbon coating is of a different colour and/or transparency to the tube.

To further facilitate the ability of medical personnel to clearly identify the location of the indicia on the ribbon coating, it is necessary that the ribbon coating be visually distinguishable from the tube substrate. Preferably, the color difference value delta E between the ribbon coating and the tube body is greater than 5; and/or the tube transparency is greater than 50% and the ribbon coating opacity is greater than 50%. The color difference value Δ E is expressed as:

wherein, L represents brightness, a represents red and green degree, and b represents yellow and blue degree.

The comprehensive effects brought by the invention are as follows:

1. the surface of the polytetrafluoroethylene tube wall is activated, so that the surface reaction activity is improved, the surface energy of the polytetrafluoroethylene tube wall surface is reduced, the water-based pigment can be soaked and uniformly coated on the polytetrafluoroethylene tube wall, and the coloring difficulty is reduced.

2. In order to improve the color fastness of the ribbon coating, it is not sufficient to simply improve the adhesion. A low surface energy surface treatment is only a necessary condition to ensure that the ribbon is strong. The color ribbon can be firmly attached to the surface of the tube body, and the requirement of strong adhesive force between the pigment and the tube wall is met. By adding the tannic acid, the surface affinity of the aqueous pigment is effectively improved, namely the adhesive force of the aqueous pigment is enhanced, so that the aqueous pigment can be attached and crosslinked on the surface of a pipe wall.

3. The invention has simple and high-efficiency process. The optimal process can promote the edge regularity of the color band, and further improve the accurate positioning of the polytetrafluoroethylene tube product on peripheral tissues and organs in endoscope-assisted medical treatment such as ERCP operation and the like.

4. The polytetrafluoroethylene tube obtained by the method has high color fastness of the color band coating and good edge regularity, can further ensure the appearance of the tube body and certain mechanical transverse rigidity and longitudinal tensile strength, and is convenient to be sent to a part to be treated.

Drawings

FIG. 1 is a schematic drawing of a ribbon coating obtained by the method of preparation of examples of the present invention and comparative examples: a is a graph of a polytetrafluoroethylene tube and a graph after ion surface treatment, b is a graph of a color band diagram of pigment modification-surface ion modification-cover die spraying of example 1, c is a graph of a color band diagram of pigment non-modification-surface ion modification-cover die spraying of comparative example 1, d is a graph of a product after multiple spraying and curing of example 1, and the three-ring water-based pigment of the color band coating is solid green-methyl blue-solid green in sequence.

FIG. 2 is a schematic drawing of a ribbon coating obtained by the method of preparation according to the example of the present invention and the comparative example: a is the pigment modification-surface ion modification-annular printing color band diagram of example 2, b is the pigment non-modification-surface ion modification-annular printing color band diagram of comparative example 2, c is the pigment modification-surface acid etching modification-cover mold spraying color band diagram of example 3, d is the pigment non-modification-surface acid etching modification-cover mold spraying color band diagram of comparative example 3,

FIG. 3 is a diagram of a product of a polytetrafluoroethylene tube with a color band coating obtained by the preparation method of example 3, namely, after acid etching surface treatment, annular printing coating and curing for three times.

Detailed Description

The present invention will be further explained with reference to the following embodiments and the accompanying drawings, but it should be understood that the scope of the present invention is not limited thereto. In the present embodiment, the plasma sputtering apparatus is manufactured by BAL-TEC corporation of switzerland, model SCD005, and the plasma surface treatment is preferably: the vacuum degree of the cavity is 1mbar, the distance between the surface of the polymer film and the metal target is 40mm, and the target surface is iron. Of course, the skilled person can select the chamber vacuum, the target surface distance and the above mentioned target surface metal species reasonably according to the coating size and thickness.

Example 1

A preparation method of a polytetrafluoroethylene tube color band coating comprises the following steps:

firstly, preparing and treating a polytetrafluoroethylene tube body.

The preparation method of the polytetrafluoroethylene tube body comprises the following steps: and uniformly mixing and curing the polytetrafluoroethylene dispersing material and the auxiliary agent, extruding the polytetrafluoroethylene pasty material, and molding and sintering to form. The die pressing sintering process comprises the steps of extruding polytetrafluoroethylene paste into a pipe die, compacting and molding by a press, and sintering by a sintering furnace at 360 ℃, wherein the auxiliary agent is kerosene.

The polytetrafluoroethylene tube body treatment method of the embodiment adopts plasma surface treatment.

The plasma surface treatment method comprises the following steps: a, placing a polyvinyl chloride pipe body into a plasma sputtering instrument, b, vacuumizing a sputtering cavity to 0.5mbar, filling inert gas to the vacuum degree of 1mbar, c, supplying power and heating a hot cathode to form plasma, bombarding a metal target surface, and d, performing synergistic treatment on the surface of the pipe body by the plasma and sputtered metal atoms. The metal target surface is an iron target. The resulting ptfe tube transparent body is shown in fig. 1a, with a plasma surface treatment location within the frame.

② modifying the color ribbon pigment.

The pigment modification method comprises the following steps: dissolving the water-based pigment by using a solvent, adding tannic acid and an acidic stabilizer, and uniformly mixing to obtain the modified color band pigment, wherein the addition amount of the tannic acid is 3 wt%. The water-based pigment is a conventional medical acidic water-based pigment. In the present embodiment, methyl blue is used as an example of the aqueous pigment unless otherwise specified.

The addition of tannic acid alone tends to cause flocculation of the aqueous pigment and therefore the addition of a suitable acidic stabilizer is necessary. The solvent is (1:1) v/v water-ethanol mixed liquor, the acid stabilizer is hydrochloric acid, and the pH value of the modified color band pigment is adjusted to be 3.

Thirdly, coating color ribbon pigment on the outer wall of the tube body;

the coating method of the color ribbon pigment is a cover die spraying method, and comprises the following process steps: after the surface activity treatment is carried out on the area to be coated of the polytetrafluoroethylene tube, the rest area is covered by a mold, only the surface gap of the area to be coated is reserved, a spray gun is used for spraying the polytetrafluoroethylene tube wrapped by the mold, and then the mold is removed.

The ribbon edge regularity can be obviously improved by adopting the coating process of the embodiment. For surgical medicine, especially for endoscopic-assisted medicine, where the operating space is limited, slight differences in position can result in significant increases in medical risk, such as adjacent to the aorta, the main veins, or the great nerves. The good regularity of the color band obtained by the process is guaranteed by accurate position calibration, and the product is more beautiful. The covering mould is made by resin hole injection molding.

And fourthly, curing the color band coating. And (3) placing the polytetrafluoroethylene tube coated with the color ribbon pigment into a heating device for drying and curing for 20min, wherein the curing temperature is 280 ℃.

The polytetrafluoroethylene tube with the color band coating prepared by the preparation method comprises a tube body and at least one color band coating, wherein the color band coating at least partially covers the outer wall of the tube body; and the color and transparency of the ribbon coating is different from those of the tube.

To further facilitate the ability of medical personnel to clearly identify the location of the indicia on the ribbon coating, it is necessary that the ribbon coating be visually distinguishable from the tube substrate. The color difference value delta E between the color band coating and the tube body is more than 5; the transparency of the tube body is more than 50%, and the opacity of the ribbon coating is more than 50%. The color difference value Δ E is expressed as:

wherein, L represents brightness, a represents red and green degree, and b represents yellow and blue degree. The polytetrafluoroethylene tube and the color band coating obtained by the preparation method of the embodiment are shown in fig. 1b and fig. 1d, fig. 1d is a schematic diagram of a final product obtained by multiple spraying and curing after surface treatment of the tube body, and the three-ring water-based pigment of the color band coating is solid green-methyl blue-solid green in sequence. It can be clearly shown from the figure that the polytetrafluoroethylene tube after surface treatment by iron atom flow and plasma is sprayed with modified water-based pigment under the shielding of a mould to obtain a color band coating with good color fastness and high edge regularity, the tube is not obviously deformed after repeated coating and drying, and the color difference and the transparency difference are obvious, thereby being beneficial to the accurate positioning by using the color band by medical operation or auxiliary personnel.

Blank comparison

In the blank comparison, the unmodified raw water pigment is directly coated on the polytetrafluoroethylene tube which is not subjected to surface modification by adopting a spraying method and an annular brushing method respectively. The experimental result shows that the pigment is condensed in a bead shape and cannot be effectively soaked and attached to the surface of the polytetrafluoroethylene.

Comparative example 1

This comparative example was conducted by the method of preparation of example 1, except that the aqueous pigment was not subjected to surface modification of polytetrafluoroethylene, and only the modified pigment was used for the in-mold spraying. As shown in fig. 1c, the ribbon has a relatively neat edge, but the coating in the middle of the ribbon is slightly stripped off due to poor affinity and binding of the outer wall of the tube.

Example 2

This example and its comparative example were carried out using the manufacturing method of example 1, except that the method of coating the color ribbon pigment of this example was the ring printing method, and

2a, treating the surface of the pipe body by adopting plasma, and adding a tannic acid modifier into the water-based pigment;

2b (comparative example 2) the tube body is subjected to plasma surface treatment, and the water-based pigment is not added with a tannic acid modifier;

the annular printing method comprises the following process methods: immersing the inner wall of the annular brush head into the modified color ribbon pigment, feeding the polytetrafluoroethylene tube into the annular brush head, attaching the bristles in the annular brush head to the outer wall of the tube body, performing rotary coating, and then feeding the polytetrafluoroethylene tube out. The annular printing equipment has simple structure and higher production efficiency. However, inevitably, the circular printing method is affected by the circular brush head, and the edge of the ink ribbon coating cannot be guaranteed to be neat effectively in the rotary printing process, as shown in fig. 2a, the edges of the ink ribbon are uneven. As shown in fig. 2b, the ribbon is more severely peeled off.

Example 3

The embodiment and the comparative example were carried out by the method of embodiment 1, except that the polytetrafluoroethylene tube body treatment method of the embodiment employs acid etching surface treatment, and

2c, coating the pipe body by adopting a cover die spraying method, and adding a tannic acid modifier into the water-based pigment;

2d (comparative example 3) the tube was coated by overmoulding spray coating, the aqueous pigment was not supplemented with a tannic acid modifier;

and 3, coating the pipe body by adopting a ring printing method, adding a tannic acid modifier into the water-based pigment, and coating and curing for three times.

The acid etching surface treatment method comprises placing the polyvinyl chloride pipe body into an acid etching tank, oscillating for 3min, cleaning with 50% ethanol water solution, and blow-drying the lotion; the treatment solution in the acid etching tank is a hydrochloric acid-hydrofluoric acid mixed solution containing 5 wt% of HCl and 1 wt% of HF. As shown in fig. 2c, the combination of the acid etching surface treatment method and the cover mold spraying method can effectively coat the outer wall of the tube body with the color ribbon coating with a neat edge, but the acid etching surface treatment uniformity is poor, the color ribbon coating thickness is uneven, and the color difference and the transparent visual effect are not optimal. Without the binding support of tannic acid, there was peeling at the edges and became out of alignment as shown in fig. 2 d.

As shown in FIG. 3, the ring printing method has ragged edges but good color fastness, and the difference of color difference and transparency is obvious. And after curing and drying for many times, the mechanical strength of the polytetrafluoroethylene tube becomes low, and the tube body is slightly deformed under the influence of the acting force of the annular brush head.

Although the present invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. Further, it should be understood that the various aspects recited herein, portions of different embodiments, and various features recited may be combined or interchanged either in whole or in part. In the various embodiments described above, those embodiments that refer to another embodiment may be combined with other embodiments as appropriate, as will be appreciated by those skilled in the art. Furthermore, those skilled in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.

Claims (14)

1. A preparation method of a polytetrafluoroethylene tube color ribbon coating is characterized by comprising the following steps: preparing and treating a polytetrafluoroethylene tube body; secondly, modifying color ribbon pigment; thirdly, coating color ribbon pigment on the outer wall of the tube body; fourthly, curing the color band coating;

in the first step, the polytetrafluoroethylene tube body is prepared by uniformly mixing and curing the polytetrafluoroethylene dispersing material and the auxiliary agent, then extruding the polytetrafluoroethylene pasty material, and molding and sintering to form;

the die pressing sintering process comprises the steps of extruding polytetrafluoroethylene paste into a pipe die, compacting and forming by a press, and sintering by a sintering furnace at 360-380 ℃, wherein the auxiliary agent is No. 70-No. 200 petroleum solvent oil;

in the first step, the polytetrafluoroethylene tube body treatment method is acid etching surface treatment or plasma surface treatment;

the acid etching surface treatment method comprises placing the polytetrafluoroethylene tube body into an acid etching tank, oscillating for 3min, cleaning with 50% ethanol water solution, and blow-drying the lotion; the treatment solution in the acid etching tank is a hydrochloric acid-hydrofluoric acid mixed solution containing 5 wt% of HCl and 1 wt% of HF;

the plasma surface treatment method comprises the steps of (a) placing a polytetrafluoroethylene tube body into a plasma sputtering instrument, (b) vacuumizing a sputtering cavity to 0.1-0.5 mbar, introducing inert gas to the vacuum degree of 1-2 mbar, supplying power to a hot cathode for heating to form plasma, bombarding a metal target surface, and (d) performing cooperative treatment on the surface of the tube body by the plasma and sputtered metal atoms;

in the second step, the water-based pigment is dissolved by using a solvent, the tannic acid and the acidic stabilizer are added, and the mixture is uniformly mixed to obtain the modified color ribbon pigment, wherein the addition amount of the tannic acid is 1 wt% -5 wt%.

2. The method of claim 1, wherein the metal target surface metal is an iron, copper, silver, or gold target.

3. The method of claim 2, wherein the metal target surface metal is an iron target or a copper target; plasma surface treatment: the vacuum degree of the cavity is 1mbar-2mbar, and the distance between the surface of the polytetrafluoroethylene tube body and the metal target is 40 mm.

4. The method according to claim 3, wherein the aqueous pigment is a conventional medical acidic aqueous pigment comprising at least one of hematoxylin, carmine, acid fuchsin, methyl blue, fast green, and eosin.

5. The method of claim 4, wherein the aqueous pigment is methyl blue or fast green.

6. The method according to claim 4, wherein the solvent is water and/or ethanol and the acidic stabilizer is acetic acid, hydrochloric acid or citric acid.

7. The method of claim 6, wherein the acidic stabilizer provides a pH of the modified ribbon pigment of 3 to 5.

8. The method of claim 1, wherein in step (c), the ribbon pigment is applied by a process including die coating, ring printing, and dip printing.

9. The method of claim 8, wherein the ring printing method is: immersing the inner wall of the annular brush head into the modified color ribbon pigment, feeding the polytetrafluoroethylene tube into the annular brush head, attaching the bristles in the annular brush head to the outer wall of the tube body, performing rotary coating, and then feeding the polytetrafluoroethylene tube out.

10. The method of claim 8, wherein in step iii, the ribbon pigment is applied by die coating, the process comprising: after the surface activity treatment is carried out on the area to be coated of the polytetrafluoroethylene tube, the rest area is covered by a mold, only the surface gap of the area to be coated is reserved, a spray gun is used for spraying the polytetrafluoroethylene tube wrapped by the mold, and then the mold is removed.

11. The method of claim 10, wherein the cover die is injection molded with resin holes or punched with forged metal tubes.

12. The method according to claim 1, wherein in the step (iv), the polytetrafluoroethylene tube coated with the color ribbon pigment is placed into a heating device to be dried and cured for 10min to 30min, and the curing temperature is 250 ℃ to 330 ℃.

13. The color ribbon coated polytetrafluoroethylene tube prepared by the preparation method according to any one of claims 1 to 12, comprising a tube body and at least one color ribbon coating, wherein the color ribbon coating at least partially covers the outer wall of the tube body; and the ribbon coating is of a different colour and/or transparency to the tube.

14. The polytetrafluoroethylene tube according to claim 13 wherein the color difference Δ Ε of the ribbon coating and the tube body is greater than 5; and/or

The transparency of the tube body is more than 50%, and the opacity of the color band coating is more than 50%;

the color difference value Δ E is expressed as:

wherein, L represents brightness, a represents red and green degree, and b represents yellow and blue degree.

Images