Firmly-bonded hydrophilic lubricating coating and preparation method thereof

Abstract

The invention discloses a firmly combined hydrophilic lubricating coating and a preparation method thereof.In the hydrophilic lubricating coating, an oleophylic bonding layer is connected with the surface of a base material, a hydrophilic lubricating layer is far away from the surface of the base material, and the oleophylic bonding layer and the hydrophilic lubricating layer are mutually diffused, permeated and chemically cross-linked to form a transition interval and have no obvious interface; from the inner surface combined with the base material to the outer surface in contact with the air, the lipophilicity of the coating is reduced, and the hydrophilicity is improved. The hydrophilic lubricating coating firmly combined with the base material can be prepared through single-time coating and single-time illumination, and the process is simple.

Description

Technical Field

[0001] The invention relates to a hydrophilic lubricating coating, in particular to a surface hydrophilic lubricating coating for a medical intervention catheter and a guide wire, belonging to the technical field of medical coatings. Background Art

[0002] Although the hydrophilic lubricating coating bonded by physical adsorption on the surface is easy to achieve mass production, it is easy to fall off during the production, storage and use of catheters and guidewires, especially the new generation of ready-to-use catheters and guidewires, which have been stored in pure water or saline before use, and do not require any advance treatment and can be used directly after opening the bag. Therefore, catheter and guidewire manufacturers use different methods to continuously improve the bonding firmness between the coating and the substrate while ensuring hydrophilic lubricity. In addition, one of the more important hydrophilic lubricating coating preparation technologies currently uses a UV curing process based on polyvinyl pyrrolidone (PVP), which has the advantages of high efficiency and safety. One method is to directly apply a water-soluble polymer coating containing PVP on the surface of the catheter and guidewire, and then perform a cross-linking reaction to allow PVP to adsorb or cross-link in the water-soluble polymer network structure (hydrogel) to improve the durability of hydrophilic lubrication. For example, patent document CN 111514378B discloses a method for preparing a central venous catheter, which includes a tube body and a coating formed on the surface of the tube body, wherein the coating composition includes at least one photosensitive functional compound containing a lysine structure and at least one photocurable polymer copolymerized from components including a water-soluble polymerizable photosensitive monomer and a hydrophilic monomer. Patent document CN110564200A discloses a hydrophilic coating, which includes the following components: a crosslinking agent, a lubricant, and a solvent. The coating prepared with the crosslinking agent is applied to the surface of a medical device to form a lubricating layer, which significantly reduces the friction coefficient of the surface of the medical device, has good lubricity, and can be used multiple times.

[0003] The problem with the above single coating method is that although the hydrophilic coating undergoes a cross-linking reaction and the lubrication durability is improved, the adhesion between the hydrogel network containing PVP and the oily matrix material is still not strong enough and is easy to fall off as a whole.

[0004] Therefore, researchers have developed a double-layer coating method based on the fact that a single coating cannot really solve the problem of firm bonding with the substrate, that is, the coating is divided into two parts: a bottom layer (adhesion-enhancing layer, connecting layer) and a top layer (hydrophilic lubricating layer). The bottom layer is mainly composed of polyurethane, acrylates or polyisocyanates, and acts as a bridge between the substrate and the top layer through photocuring. The top layer mainly uses a PVP cross-linked network structure containing a higher molecular weight to provide a good hydrophilic lubricating effect. For example, patent document CN107405430B discloses a lubricating coating including a primer and a top layer. The primer forms a strong effect with the substrate and can also form a covalent bond with the top layer to form a stable network coating. Patent document CN110819224B discloses a coating composition of a photocurable polyurethane and a polymerizable hydrophilic polymer as a pre-coating. The polyurethane has a strong adhesion, and the hydrophilic polymer exposed on the outer surface of the pre-coating has better stretchability in the subsequent aqueous coating liquid. The residual unsaturated double bonds can participate in the polymerization and curing of the subsequent functional coating, thereby enhancing the adhesion of the functional coating between the substrates. Patent document CN 109954169B discloses a coating composition, which contains a novel photocurable polyurethane, which contains a tertiary amine group on the main chain, and has an unsaturated double bond group and a photosensitive group unit on the side chain. The coating composition of the photocurable polyurethane is used as a pre-coating layer, and then a hydrophilic lubricating coating is formed on the pre-coating layer, which effectively improves the adhesion of the hydrophilic lubricating coating on the substrate and improves the comprehensive performance of the coating. Based on this technology, patent document CN111514380B discloses a ureteral stent, which has at least one pre-coating layer formed on its surface and at least one hydrophilic lubricating coating formed on the pre-coating layer.

[0005] Although the above two coating methods solve the problem of adhesion of the hydrophilic lubricating layer to the substrate, they require two-step dipping and two-step light curing, which results in a long production line and affects the efficiency of large-scale mass production. In addition, as the bottom layer with the function of enhancing adhesion and connection, in order to ensure the dual function with the substrate and the top layer, a coating composition with a special structure is required, and there is usually no commercial product, so it needs to be designed in advance and prepared through multi-step synthesis.

[0006] In summary, a hydrophilic lubricating coating preparation technology is needed that can ensure that the hydrophilic lubricating coating is firmly bonded to the substrate, avoid preliminary synthesis, and reduce the number of coating and illumination times. Summary of the invention

[0007] The present invention provides a method for preparing a firmly bonded hydrophilic lubricating coating by a single coating, wherein the coating has excellent hydrophilic lubricity and high firmness.

[0008] In a first aspect, the present invention provides a method for preparing a firmly bonded hydrophilic lubricating coating, wherein the raw materials for preparing the coating include the following components based on 100 parts by weight:

[0009] 5-30 parts of water-soluble monomer

[0010] 1-5 parts water-soluble crosslinking agent

[0011] Water-soluble photoinitiator 0.1-3 parts

[0012] Hydrophilic lubricant 0.1-10 parts

[0013] Oily monomer 5-20 parts

[0014] 1-5 parts of oily crosslinking agent

[0015] Oily photoinitiator 0.1-3 parts

[0016] Emulsifier 0.1-10 parts

[0017] Water balance;

[0018] The method comprises the following steps:

[0019] S1, preparation of hydrophilic lubricating coating liquid

[0020] S11, mixing the oily monomer, the oily crosslinking agent, and the oily photoinitiator uniformly for later use;

[0021] S12, stirring and dissolving a water-soluble monomer, a water-soluble crosslinking agent, a water-soluble photoinitiator and a hydrophilic lubricant in water, then adding an emulsifier under stirring, and continuing stirring for 30 minutes;

[0022] S13, slowly dropping the mixed solution obtained in S11 into the system obtained in S12, stirring at high speed until a stable emulsion is formed, to obtain a hydrophilic lubricating coating liquid;

[0023] S2, preparation of hydrophilic lubricating coating

[0024] S21, coating the hydrophilic lubricating coating liquid obtained in S1 on the surface of the substrate to be coated, and allowing the coating to stand for 10 to 60 minutes after the coating is completed to allow part of the water to evaporate and form a hydrophilic and lipophilic phase separation to produce a hydrophilic layer and an lipophilic layer;

[0025] S22, finally using ultraviolet light or ultraviolet-visible light for radiation curing and cross-linking to obtain a hydrophilic lubricating coating.

[0026] Preferably, the high-speed stirring speed is ≥300 rpm, and the time is 30 minutes to 1 hour.

[0027] Preferably, the substrate to be coated is an oily substrate, such as a polyurethane catheter or guidewire.

[0028] Preferably, the coating method is dipping, spraying, brushing or showering, preferably dipping.

[0029] More preferably, the clean and dry substrate to be coated is immersed in the hydrophilic lubricating coating liquid obtained in S1 for 30 seconds, and then the substrate to be coated is pulled out at a pulling speed of 5 cm / s and allowed to stand for 30 minutes.

[0030] Preferably, the water-soluble monomer is at least one of methacrylamide, acrylamide, (3-acrylamidopropyl)trimethylammonium chloride, methacryloxyethyltrimethylammonium chloride, 2-methacryloxyethylphosphocholine, and 3-sulfonic acid propyl methacrylate potassium salt.

[0031] Preferably, the water-soluble crosslinking agent is at least one of N,N′-vinylbisacrylamide, N,N′-vinylbismethacrylamide, polyethylene glycol diacrylate, and polyethylene glycol dimethacrylate.

[0032] Preferably, the water-soluble photoinitiator is at least one of phenyl (2,4,6-trimethylbenzoyl) phosphate lithium salt and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone.

[0033] Preferably, the hydrophilic lubricant is polyvinyl pyrrolidone or a copolymer thereof.

[0034] Preferably, the oily monomer is at least one of butyl acrylate, isooctyl acrylate, lauryl acrylate and lauryl methacrylate.

[0035] Preferably, the oily crosslinking agent is at least one of ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, diethylene glycol diacrylate, 2,2-dimethyl-1,3-propane diyl diacrylate, glycerol triacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate.

[0036] Preferably, the oily photoinitiator is at least one of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, benzophenone and its derivatives, and camphorquinone.

[0037] Preferably, the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, polyoxyethylene ether and polyvinyl alcohol.

[0038] In a second aspect, the present invention provides a firmly bonded hydrophilic lubricating coating prepared by the method described in the first aspect.

[0039] Preferably, in the hydrophilic lubricating coating, the surface connected to the substrate is a lipophilic adhesive layer, and the surface away from the substrate is a hydrophilic lubricating layer, and the lipophilic adhesive layer and the hydrophilic lubricating layer diffuse, penetrate and chemically cross-link with each other to form a transition zone without an obvious interface. The lipophilicity of the coating decreases and the hydrophilicity increases from the inner surface combined with the substrate to the outer surface in contact with the air.

[0040] Compared with the prior art, the advantages of the present invention are:

[0041] 1. A hydrophilic lubricating coating that is firmly bonded to the substrate can be prepared by a single coating and a single light exposure, and the process is simple;

[0042] 2. Common commercial raw materials, avoiding the synthesis of complex monomers or cross-linkable polymer precursors. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the formation process of the hydrophilic lubricating / oleophilic bonding double-layer structure.

[0044] Figure 2 Changes in water contact angle of polyurethane catheter material before (a) and after (b) coating with a hydrophilic lubricating coating.

[0045] Figure 3 To test the friction coefficient of the polyurethane catheter surface and the firmness of the hydrophilic lubricating coating. DETAILED DESCRIPTION

[0046] The present application is further described below in conjunction with specific embodiments.

[0047] It should be noted that the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of this application without substantially changing the technical content.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0049] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0050] As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measurement or value. The degree of flexibility for a particular variable can be easily determined by one skilled in the art.

[0051] As used herein, the term "at least one of" is intended to be synonymous with "one or more of." For example, "at least one of A, B, and C" expressly includes only A, only B, only C, and combinations of each thereof.

[0052] Concentration, amount and other numerical data can be presented in range format herein.It should be understood that such range format is only used for convenience and simplicity, and should be flexibly interpreted as not only including the numerical value clearly described as range limit, but also including all single numerical values ​​or sub-ranges contained in the range, just as each numerical value and sub-range are clearly described.For example, the numerical range of about 1 to about 4.5 should be interpreted as not only including the limit value of 1 to about 4.5 clearly described, but also including single numerals (such as 2,3,4) and sub-ranges (such as 1 to 3,2 to 4, etc.).The same principle is applicable to the scope of only narrating a numerical value, such as "less than about 4.5", which should be interpreted as including all the above-mentioned values ​​and ranges.In addition, no matter how the breadth of the described range or feature is, this explanation should be applicable.

[0053] After the hydrophilic lubricating coating liquid configured by the present invention is coated on an oily substrate, due to the principle of like dissolves like, the oleophilic substance will be enriched on the surface of the oily substrate and gradually separated from the hydrophilic lubricating component. After a certain period of time, a double-layer structure of a hydrophilic lubricating layer and an oleophilic adhesive layer is formed on the surface of the substrate. Then, photocuring is performed, and the hydrophilic lubricating layer and the oleophilic adhesive layer undergo photopolymerization and cross-linking reactions at the same time. The hydrophilic lubricating layer and the oleophilic adhesive layer diffuse, penetrate and chemically cross-link with each other to form a transition zone without an obvious interface. Therefore, the hydrophilic lubricating layer and the oleophilic adhesive layer are firmly bonded. Furthermore, due to the particularity of the monomer of the oleophilic adhesive layer (using acrylic monomers commonly used in pressure-sensitive adhesives), the formed oleophilic adhesive layer also has a strong effect on the oily substrate, has strong water resistance, and it is not easy for moisture to diffuse into the primer to destroy the bond with the substrate, thereby preparing a catheter or guidewire with a firmly bonded hydrophilic lubricating coating. The entire technical solution process is as follows: Figure 1 shown.

[0054] Example

[0055] The raw materials for preparing the coating include the following components based on a total of 1000 g:

[0056] Water-soluble monomer: 2-methacryloyloxyethyl phosphorylcholine 200g

[0057] Water-soluble crosslinking agent: polyethylene glycol diacrylate (average molecular weight M n =575)30g

[0058] Water-soluble photoinitiator: 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone 5g

[0059] Hydrophilic lubricant: polyvinyl pyrrolidone (K-90) 50g

[0060] Oily monomer: 2-ethylhexyl acrylate 100g

[0061] Oily crosslinker: Ethylene glycol diacrylate 20g

[0062] Oily photoinitiator: benzophenone 3g

[0063] Emulsifier: Sodium lauryl sulfate 8g

[0064] Emulsifier: polyvinyl alcohol 4g

[0065] Water 580g;

[0066] The method comprises the following steps:

[0067] S1, preparation of hydrophilic lubricating coating liquid

[0068] S11, mixing the oily monomer, the oily crosslinking agent, and the oily photoinitiator uniformly for later use;

[0069] S12, stirring and dissolving the water-soluble monomer, the water-soluble crosslinking agent, the water-soluble photoinitiator and the hydrophilic lubricant in water, then adding the emulsifier under stirring at 300 rpm, and continuing to stir for 30 minutes;

[0070] S13, slowly dropwise adding the mixed solution obtained in S11 to the system obtained in S12, controlling the entire dropping process to be 30 minutes, and the stirring speed to be 300 rpm. After the dropping is completed, the stirring speed is increased to 500 rpm and stirred for 30 minutes to form a stable emulsion, thereby obtaining a hydrophilic lubricating coating liquid;

[0071] S2, preparation of hydrophilic lubricating coating

[0072] S21, immersing the polyurethane catheter whose surface has been cleaned and dried with ethanol into the hydrophilic lubricating coating liquid obtained in S1 for 30 seconds, then pulling out the catheter at a pulling speed of 5 cm / s and letting it stand for 30 minutes to allow part of the water to evaporate and form a hydrophilic and lipophilic phase separation, thereby generating a hydrophilic layer and a lipophilic layer;

[0073] S22, finally, a 500W ultraviolet dual light source with a wavelength of 365nm was used, and the distance from the front and back of the catheter was 15cm respectively, to ensure that the light source irradiated the entire coating area for radiation curing and cross-linking. The irradiation time was 2 minutes to obtain a polyurethane catheter coated with a hydrophilic lubricating coating.

[0074] The hydrophilicity of the hydrophilic lubricating layer formed by the water-soluble monomer, the water-soluble crosslinking agent, and the hydrophilic lubricant on the surface of the substrate is verified by the water contact angle. The water contact angle of the polyurethane catheter material surface (PU) without the hydrophilic lubricating coating of this embodiment is 80.0°. Figure 2 (a); when the hydrophilic lubricating coating liquid of this embodiment is applied and dried and solidified, the surface water contact angle is close to 0°, which is a completely hydrophilic state, such as Figure 2 As shown in (b) in .

[0075] The friction coefficient and firmness test of the hydrophilic lubricating polyurethane catheter surface prepared in this example are as follows: Figure 3 As shown, it can be verified from the test results that the surface friction coefficient of the polyurethane catheter is significantly reduced by coating the hydrophilic lubricating coating of the embodiment (i.e., Coated PU), from the friction coefficient of 0.9680 to 0.0301, and after 50 cycles, the surface friction coefficient of the polyurethane catheter material coated with the hydrophilic lubricating coating of the embodiment remains basically unchanged, maintained at about 0.03, which fully demonstrates the firm bonding of the hydrophilic lubricating coating to the substrate.

[0076] Therefore, the hydrophilic lubricating coating prepared by the present invention has good hydration ability and can significantly reduce the friction coefficient of the catheter or guide wire surface in a wet state.

[0077] The above-mentioned implementation cases are only preferred implementation cases in the present invention, but the implementation methods of the present invention are not limited to the above-mentioned implementation cases. For example, various forms of combinations of the schemes in the embodiments, any other changes, modifications, substitutions, and combinations made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are within the protection scope of the present invention.

Claims

1. A method for preparing a firmly bonded hydrophilic lubricating coating, characterized in that: The raw materials for preparing the coating include the following components based on 100 parts by weight: 5-30 parts of water-soluble monomer 1-5 parts water-soluble crosslinking agent Water-soluble photoinitiator 0.1-3 parts Hydrophilic lubricant 0.1-10 parts Oily monomer 5-20 parts 1-5 parts of oily crosslinking agent Oily photoinitiator 0.1-3 parts Emulsifier 0.1-10 parts Water balance; The method comprises the following steps: S1, preparation of hydrophilic lubricating coating liquid S11, mixing the oily monomer, the oily crosslinking agent, and the oily photoinitiator uniformly for later use; S12, stirring and dissolving a water-soluble monomer, a water-soluble crosslinking agent, a water-soluble photoinitiator and a hydrophilic lubricant in water, then adding an emulsifier under stirring, and continuing stirring for 30 minutes; S13, slowly dropping the mixed solution obtained in S11 into the system obtained in S12, stirring at high speed until a stable emulsion is formed, to obtain a hydrophilic lubricating coating liquid; S2, preparation of hydrophilic lubricating coating S21, coating the hydrophilic lubricating coating liquid obtained in S1 on the surface of the substrate to be coated, and allowing the coating to stand for 10 to 60 minutes after the coating is completed to allow part of the water to evaporate and form a hydrophilic and lipophilic phase separation to produce a hydrophilic layer and an lipophilic layer; S22, finally using ultraviolet light or ultraviolet-visible light for radiation curing and cross-linking to obtain a hydrophilic lubricating coating.

2. The method according to claim 1, characterized in that The high-speed stirring speed is ≥300 rpm, and the time is 30 minutes to 1 hour.

3. The method according to claim 1, characterized in that The substrate to be coated is an oily substrate.

4. The method according to claim 1, characterized in that The coating method is dipping, spraying, brushing or showering, with dipping being preferred.

5. The method according to claim 1, characterized in that The clean and dry substrate to be coated was immersed in the hydrophilic lubricating coating liquid obtained in S1 for 30 seconds, and then the substrate to be coated was pulled out at a pulling speed of 5 cm / s and allowed to stand for 30 minutes.

6. A firmly bonded hydrophilic lubricating coating prepared by the method according to any one of claims 1 to 5.

7. The hydrophilic lubricating coating according to claim 6, characterized in that: In the hydrophilic lubricating coating, the surface connected to the substrate is the oleophilic adhesive layer, and the surface away from the substrate is the hydrophilic lubricating layer. The oleophilic adhesive layer and the hydrophilic lubricating layer diffuse, penetrate and chemically cross-link with each other to form a transition zone without an obvious interface. The oleophilicity of the coating decreases and the hydrophilicity increases from the inner surface combined with the substrate to the outer surface in contact with the air.

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