CN101279106A - Preparation method of gel injection molding of porous titanium-cobalt alloy medical implant - Google Patents

Abstract

The invention discloses a gel injection molding preparation method for a porous titanium-cobalt alloy medical implant, which belongs to the technical field of medical material preparation. The monomer acrylamide, cross-linking agent N, N'-methylenebisacrylamide and deionized water are prepared into a premix of a certain concentration, and the dispersant oleic acid is added to suspend the titanium cobalt powder in the premix to make a slurry , adjust the pH value to 9.0-10.0, then add an appropriate amount of catalyst N, N, N', N'-tetramethylethylenediamine and initiator ammonium persulfate and stir evenly, and inject it into the mold after exhausting, and the single The body undergoes a polymerization reaction to form a network structure to wrap the titanium-cobalt powder and become a green body shaped by a macromolecular network. The green body is dried, degummed, and sintered to obtain the product. In addition, the porosity and mechanical properties of the porous titanium-cobalt alloy can be changed by adjusting the solid content to meet the performance requirements of various medical implants. The invention does not need complex equipment and special degreasing process, has simple process, greatly reduces production cost, and is especially suitable for the characteristics of various specifications and large-scale production of medical implants.

Description

Preparation method of gel injection molding of porous titanium-cobalt alloy medical implant

technical field

The invention belongs to the technical field of medical material preparation, and in particular provides a method for preparing a porous medical implant with excellent biocompatibility and complex shape by gel injection molding.

Background technique

Titanium-based alloy has good biocompatibility, low density, close to human bone tissue, low elastic modulus, and significantly higher strength than other metals, and good corrosion resistance. Its various characteristics are closer to cortical bone than other metals. , suitable for use as a biomedical implant material. Porous titanium-cobalt alloy has the structural advantages of a porous three-dimensional scaffold. The three-dimensional through pores and the appropriate surface microporous structure provide a scaffold for the growth of surrounding tissues, so that the tissues and implants can be firmly fixed physiologically; Metals have excellent chemical and mechanical properties and biocompatibility. Porous titanium-cobalt alloys hold great promise in medical implants.

Usually, the forming methods of porous metal materials mainly include powder metallurgy pressing method, slurry foaming method and so on. Among them, the production process of porous metal materials prepared by powder metallurgy pressing is simple, low in cost, and can obtain porous metal materials with uniform structure, but the porosity is low, and it is difficult to meet the requirements of complex shapes of medical implants, and the mold cost is relatively high. High, small-scale production costs are high; the slurry foaming method can obtain higher porosity, but the disadvantage is that it is difficult to control the size of the bubbles, so it is difficult to obtain porous materials with uniform pore size distribution, and it is difficult to obtain complex shapes.

In the present invention, the water-based acrylamide system gel injection molding technology is used to realize the preparation of porous titanium-cobalt alloy medical implants with excellent biocompatibility, complex shape, adjustable voids and mechanical properties; Injection molding technology solves the problem of difficulty in forming complex shapes, and meets the porosity requirements of medical implants, which greatly simplifies the production process. In addition, the mold cost of gel injection molding technology is very low, which solves the problem of medical implants. The problem of high cost of small-scale production; more importantly, the introduction of non-toxic and side-effect metal cobalt as an alloying element improves the strength of its implants and enhances the safety of medical implants.

Contents of the invention

The purpose of the present invention is to provide a low-cost method for preparing a porous titanium-cobalt alloy medical implant with excellent biocompatibility and tissue integration, complex shape and adjustable mechanical properties, so as to improve performance and reduce cost.

The principle of the invention is as follows: the water-based acrylamide system is used for gel injection molding. Acrylamide solutions can polymerize into high-strength, laterally linked polymer-solvent gels. The monomer acrylamide, cross-linking agent N, N'-methylenebisacrylamide and deionized water are prepared into a premix of a certain concentration, and the dispersant oleic acid is added to suspend the titanium cobalt powder in the premix to make a slurry , adjust the pH value to 9.0-10.0, then add an appropriate amount of catalyst N, N, N', N'-tetramethylethylenediamine and initiator ammonium persulfate and stir evenly, and inject it into the mold after exhausting, and the single The body undergoes a polymerization reaction to form a network structure that wraps the titanium-cobalt powder and becomes a green body shaped by a macromolecular network. The green body is dried, degummed and sintered to obtain the product, as shown in Figure 1. In addition, the porosity and mechanical properties of the porous titanium-cobalt alloy can be changed by adjusting the solid content to meet the performance requirements of various medical implants.

A gel injection molding preparation method of a porous titanium-cobalt alloy medical implant, the specific process is as follows:

1. Weigh titanium-cobalt powder respectively, wherein the cobalt powder is 2%-40% of the titanium-cobalt mixture, and ball mill it for 1-4 hours to make it evenly mixed.

2. Mix monomeric acrylamide and monomeric cross-linking agent N, N'-methylenebisacrylamide in a mass ratio (1-250): 1, and dissolve the mixture of acrylamide and cross-linking agent in deionized Water is made into a uniform and stable solution with a mass fraction of 1-55%;

3. Measure 0.01% to 3% of the volume of titanium cobalt powder and add oleic acid as a dispersant to the 2 solution, adjust the pH value to 9.0 to 10.0, stir evenly, and make a slurry;

4. Put the slurry into a high vacuum environment to exhaust for 5 to 40 minutes;

5. Coat a thin layer of release agent isooctyl alcohol on the inner wall of the mold; measure the catalyst N, N, N', N'-tetramethylethylenediamine and the monomer mass of 0.01% to 1% %~2% initiator ammonium persulfate, add to the slurry after exhausting, stir evenly;

6. Slowly inject the slurry containing the catalyst and initiator into the mold. During the injection process, use a thin glass rod to move up and down to avoid bubbles during the injection process of the slurry;

7. After the grouting is completed, put the grouting mold in a vacuum oven at 20°C to 65°C to dry;

8. After drying for 20-60 minutes, remove the mold, trim the blank, and then put it in a vacuum drying oven at 20-65°C for 30-60 hours;

9. Sintering the dried body under high vacuum to obtain a porous titanium-cobalt medical implant.

Mold making:

1. Weigh an appropriate amount of silicone rubber, add 0.8% to 2% curing initiator, and stir evenly;

2. Apply a thin layer of silicone rubber evenly on the surface of the component, avoid air bubbles during the process, and let it stand for 1 to 2 hours; apply a layer of silicone rubber every 1 to 2 hours, a total of three layers are required, and then Let stand for 12 hours.

3. Weigh an appropriate amount of gypsum powder, add 5% to 35% water, stir evenly, pour it into a carton whose size is larger than the parts, and then immerse half of the parts wrapped in silicone rubber in the carton gypsum slurry for 10 to 30 minutes Finally, lay three layers of soft paper on the gypsum cross section in the carton, then pour the gypsum slurry to cover the parts by 1 to 4 cm, and let it stand for 6 to 12 hours to make a gypsum master model;

4. Take out the parts wrapped with silicone rubber, choose a simple side, cut it with scissors, take out the outer layer of silicone rubber sleeve, put it into a plaster mold, and make a silicone rubber mold.

The advantages of the present invention are:

1. In terms of production, it provides a new technology for preparing porous titanium-cobalt alloy medical implants with excellent biocompatibility and tissue integration, complex shape, adjustable pores and mechanical properties. The strength of this material is comparable to that of pure titanium There is a significant improvement;

2. This technology does not require complex equipment or a special degreasing process. The process is simple and the production cost is greatly reduced. It is especially suitable for the characteristics of various specifications and large-scale production of medical implants.

Description of drawings

Figure 1 is the process flow chart of gel injection molding cemented carbide parts

Detailed ways

Forming and sintering:

Implementation example 1:

1. Weigh 1920g of titanium powder and 80g of cobalt powder, and mix them in a planetary ball mill for 2 hours;

2. Dissolve 159.7g monomeric acrylamide and 0.13g cross-linking agent N,N′-methylenebisacrylamide in 807ml deionized water, add the mixed powder in 1, and stir evenly;

3. Measure 4.35ml of dispersant oleic acid and add it to the 2 solution, stir evenly to make a slurry;

4. Put the 3 slurry into a high vacuum environment to exhaust for 15 minutes;

5. Apply a thin layer of release agent isooctyl alcohol on the inner wall of the mold; measure 4ml of catalyst N, N, N', N'-tetramethylethylenediamine and 4ml of initiator ammonium persulfate (to ensure enough injection molding time), add in 4 slurry, stir evenly;

6. After the grouting is completed, put it in a vacuum drying oven with a constant temperature of 60°C to dry;

7. After drying for 30 minutes, remove the mold, trim the blank, and then put it in a vacuum drying oven with a constant temperature of 60 ° C for 48 hours;

8. Sintering the dried green body under high vacuum to obtain the artificial porous titanium-cobalt hip bone replacement.

Implementation example 2:

1. Weigh 1600g of titanium powder and 50g of cobalt powder, and mix them in a planetary ball mill for 2 hours;

2. Dissolve 135g of monomeric acrylamide and 0.1g of cross-linking agent N,N'-methylenebisacrylamide in 750ml of deionized water, add the mixed powder in 1, and stir evenly;

3. Take 3.5ml of dispersant oleic acid and add it to the 2 solution, stir evenly to make a slurry;

4. Put the 3 slurry into a high vacuum environment to exhaust for 15 minutes;

5. Apply a thin layer of release agent isooctyl alcohol on the inner wall of the mold; measure 3.5ml of catalyst N, N, N', N'-tetramethylethylenediamine and 3.5ml of initiator ammonium persulfate (ensure that there is enough Injection molding time), add in 4 slurry, stir evenly;

6. After the grouting is completed, put it in a vacuum drying oven with a constant temperature of 60°C to dry;

7. After drying for 30 minutes, remove the mold, trim the blank, and then put it in a vacuum drying oven with a constant temperature of 60 ° C for 48 hours;

8. Sintering the dried green body under high vacuum to obtain the artificial porous titanium-cobalt hip bone replacement.

Mold making:

1. Weigh 200g of silicone rubber, add 2.6g of curing initiator, and stir evenly;

2. Evenly coat a thin layer of silicone rubber on the surface of the hip bone model, avoid air bubbles during the process, and let it stand for 1 hour; then weigh 300g of silicone rubber, add 3.9g of curing initiator, and stir well , coated on the last layer of silicone rubber, let it stand for 1 hour, and then repeat the previous step, a total of three layers of silicone rubber are required, and then let it stand for 12 hours.

3. Weigh 2000g of gypsum powder, add 200ml of water, stir evenly, pour it into a paper box larger than the hip bone model, then immerse half of the hip bone model wrapped in silicone rubber into the carton gypsum slurry, after 20 minutes, Lay three layers of soft paper on the cross-section of the plaster in the carton, then pour the plaster slurry to cover the hip bone model by 2cm, and let it stand for 10 hours to make a plaster master model;

4. Take out the silicone rubber-wrapped hip bone model, choose a simple side, cut it with scissors, take out the outer silicone rubber sleeve, put it into a plaster model, and make a silicone rubber mold of the hip bone.

Claims (2)

1. the gel injection moulding preparation of a porous titanium-cobalt alloy medical implant article, the sintering step that it is characterized in that specifically being shaped is:

(1), respectively take by weighing the titanium cobalt powder, wherein cobalt powder is 2%～40% of a titanium cobalt mixture, and ball milling made its mix homogeneously in 1～4 hour;

(2), with monomer acrylamide and monomer crosslinked dose of N, N '-methylene-bisacrylamide is with mass ratio (1～250): 1 mixes, and the mixture of acrylamide and cross-linking agent is dissolved in deionized water, and to make mass fraction be 1～55% uniform and stable solution;

(3), the dispersant oleic acid of measuring titanium cobalt powder volume 0.01%～3% adds in (2) solution, regulates pH value to 9.0～10.0, stirs, and makes slurry;

(4), slurry is put into high vacuum environment aerofluxus 5～40 minutes;

(5), be coated with very thin one deck releasing agent isooctanol at mould inner wall; Measure the catalyst n of monomer mass 0.01%～1%, N, N ', N '-tetramethylethylenediamine and monomer mass 0.01%～2% initiator ammonium persulfate in the slurry after the adding aerofluxus, stir;

(6), the slurry that will contain catalyst and initiator slowly injects mould, in the injection process, move up and down to avoid the slurry injection process not produce bubble with thin Glass rod;

(7), after slip casting finishes, the slip casting mould put into 20 ℃～65 ℃ vacuum drying oven inner drying;

(8), after dry 20～60 minutes, the demoulding, repaired biscuit is put into 20 ℃～65 ℃ vacuum drying oven inner drying 30～60 hours again;

(9), with base substrate sintering under fine vacuum that drying is crossed, can obtain POROUS TITANIUM cobalt medical implant.

2. the gel injection moulding preparation of a kind of porous titanium-cobalt alloy medical implant article as claimed in claim 1 is characterized in that the Mold Making step is:

(1), take by weighing an amount of silicone rubber, add 0.8%～2% curing initiator, stir;

(2), on parts surface, be coated with the very thin silicone rubber of last layer equably, to avoid producing bubble in the process, left standstill 1～2 hour; Every 1～2 hour repaste one deck silicone rubber, need three layers altogether, left standstill then 12 hours;

(3), take by weighing Gypsum Fibrosum powder, add 5%～35% water, stir, pour in the carton of size greater than parts, half of parts that will wrap up silicone rubber then immerses in carton calcium plaster, after 10～30 minutes, three layers of soft paper in Gypsum Fibrosum section shop in carton, pour calcium plaster again into to not having 1～4 centimetre of parts, left standstill 6～12 hours, make the Gypsum Fibrosum pattern;

(4), take out the parts of parcel silicone rubber, select a simple side, cut off with shears, with outer silicone rubber sleeve taking-up, put into the Gypsum Fibrosum pattern, so far make silicon rubber mould.

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