A double-grit silica gel polishing head for polishing and a preparation method thereof

Abstract

The application discloses a special polishing double-granularity silica gel grinding head and a preparation method thereof. The double-granularity silica gel grinding head comprises a fine grinding head for fine polishing and a coarse grinding head for rapid shaping from top to bottom. The fine grinding head comprises the following raw materials: liquid silicone rubber, vulcanizing agent, titanium white powder, zeolite powder, silicone oil, vulcanization accelerator and coated abrasive. The coarse grinding head comprises the following raw materials: solid silicone rubber, liquid silicone rubber, vulcanizing agent, diatomite, alumina hollow glass microspheres, silicone oil, vulcanization accelerator and coated abrasive. The special polishing double-granularity silica gel grinding head and the preparation method thereof adopt the above structure, combine the fine grinding head and the coarse grinding head with two different granularities, use the fine grinding head for fine polishing and use the coarse grinding head for rapid shaping, reduce the frequency of tool replacement, improve the processing efficiency, and use liquid silicone rubber and solid silicone rubber, which is helpful to improve the elasticity and wear resistance of the grinding head.

Description

Technical Field

[0001] This invention relates to the field of polishing materials technology, and in particular to a dual-grit silicone polishing head for polishing and its preparation method. Background Technology

[0002] Currently, there are many methods for polishing dentures, using polishing products such as tungsten carbide grinding heads, ceramic bond grinding heads, and electroplated diamond burs. These grinding consumables have high hardness, and polishing dentures that are also very hard is a hard-on-hard process. The friction process generates a lot of heat, which can easily cause cracks on the denture surface that are not visible to the naked eye, reducing the lifespan of the denture. Furthermore, the polishing gloss does not meet the requirements for use, and it is necessary to apply glaze and sinter again or use other grinding consumables with polishing paste for polishing. This method of polishing is time-consuming and increases the discomfort of the patient.

[0003] Furthermore, the main component of dentures is zirconia, which is divided into raw zirconia and sintered zirconia. Raw zirconia is a high-density pressed blank that has not been sintered at high temperatures, while sintered zirconia is a pressed blank that has been sintered at high temperatures. The most fundamental difference between raw and sintered zirconia lies in their hardness. Sintered zirconia has a hardness of 1300-1600 HV, which is very high, requiring diamond-containing abrasives for polishing, making polishing difficult and costly. Raw zirconia has a hardness of 50-80 HV, which is very low, allowing for polishing with ordinary abrasives. However, the low hardness of raw zirconia places high demands on the polishing process, requiring dentures to undergo shaping and fine polishing in a single step to ensure no microcracks occur during polishing. If a conventional two-step polishing method is used, the difference in concentricity between the fine and coarse grinding heads may cause microcracks in the denture during fine polishing, significantly increasing the scrap rate. Summary of the Invention

[0004] The purpose of this invention is to provide a special dual-grit silicone polishing head for polishing and its preparation method, so as to solve the problem of microcracks caused by the use of two polishing heads in the above-mentioned denture products during fine polishing.

[0005] To achieve the above objectives, the first aspect of the present invention provides a dual-grit silicone grinding head for polishing, which includes, from top to bottom, a fine grinding head for fine polishing and a coarse grinding head for rapid shaping.

[0006] The fine grinding head comprises the following raw materials in parts by weight:

[0007]

[0008] The coarse grinding head comprises the following raw materials in parts by weight:

[0009]

[0010] The fine grinding head and coarse grinding head in this invention have different grit sizes, which are used for fine polishing and rapid shaping, respectively. The grit size can be adjusted according to the user's needs, ranging from 120 to 6000 mesh.

[0011] Preferably, the liquid silicone rubber has a Shore hardness of 60, an elongation at break of 620%, a tensile strength of 11.4 MPa, and a tear strength of 43 kN / m.

[0012] Preferably, the solid silicone rubber has a Shore hardness of A85, a tensile strength of 8.0 MPa, a tear strength of 15 kN / m, and an elongation of 90%.

[0013] Preferably, the coated abrasive is one or more of the following: alumina, silicon dioxide, silicon carbide, diamond, aluminum silicate powder, and pumice powder, after being treated with a coupling agent.

[0014] Preferably, the coated abrasive is alumina and silicon carbide treated with a coupling agent.

[0015] Preferably, the specific preparation method of the coated abrasive is as follows:

[0016] Alumina and silicon carbide are mixed evenly at a mass ratio of 2:1, then 15% of a coupling agent ethanol solution is added, mixed evenly, and dried to obtain a coated abrasive. More preferably, the coupling agent is KH550 silane coupling agent.

[0017] Preferably, the median particle size D of titanium dioxide is... 50 ≤1μm, median particle size D of zeolite powder 50 ≤3μm, and the absolute value of the median particle size difference between zeolite powder and titanium dioxide is no greater than 2μm.

[0018] Preferably, the vulcanization accelerator includes one or more of 1,1-di(trimethylsilyl)-3-(3-methoxyphenyl)thiourea, 1-allyl-3-[3-(triethoxysilyl)propyl]thiourea, 1-methylthioethyl mercaptan, and acetone dimethylhydrazone.

[0019] Preferably, the viscosity of the silicone oil is 3000-5000 cps. The silicone oil was purchased from Jiashan Jiangnan Textile Materials Co., Ltd., and the grade is 201.

[0020] Preferably, the particle size of diatomaceous earth is 15-50 μm, and the alumina hollow glass microspheres are obtained by granulation and drying after mixing alumina, hollow glass microspheres, polyvinyl alcohol and water.

[0021] Preferably, the specific preparation process of alumina hollow glass microspheres is as follows:

[0022] Two parts of 100nm alumina nanoparticles, 25 parts of hollow glass microspheres, 10 parts of polyvinyl alcohol, and water were mixed to obtain a viscous substance with a water content of 20%. The viscous substance was granulated by a granulator, demolded, and then placed in an oven to dry at 120℃ for 4 hours to obtain alumina hollow glass microspheres.

[0023] Preferably, the vulcanizing agent is one or more of sulfur, organic peroxide, and platinum vulcanizing agent.

[0024] A second aspect of this invention provides a method for preparing a dual-grit silicone polishing head for polishing, comprising the following steps:

[0025] (1) Weigh each raw material of the fine grinding head according to the proportion, and then mix them evenly to obtain the head slurry;

[0026] (2) Weigh each raw material of the coarse grinding head according to the proportion, and then mix them evenly to obtain the tail slurry;

[0027] (3) Pour the tail slurry and the head slurry into the mold in sequence, heat and press to form a double-grained silicone grinding head.

[0028] The mold in this invention can be made into different shapes of silicone grinding head according to user needs, such as gourd shape, parallel wheel shape, bullet shape, rhombus shape, sphere shape, ellipse shape, etc.

[0029] Preferably, the slurry undergoes vulcanization during the heating process in step (3), with the vulcanization temperature being 120-150℃ and the time being 1-5h.

[0030] Preferably, for ease of use of the silicone grinding head, a fixing rod is also inserted at the bottom of the coarse grinding head, mainly for facilitating hand-held operation of the silicone grinding head.

[0031] Therefore, the present invention provides a polishing-specific dual-grit silicone grinding head with the above-described structure and its preparation method, which has the following beneficial effects:

[0032] (1) The silicone grinding head of the present invention has an upper and lower structure. The lower part is used for rapid shaping and the upper part is used for fine polishing. This allows one silicone grinding head to process one denture product simultaneously. The upper and lower parts have the same concentricity, which reduces the phenomenon of denture cracks and increases the yield.

[0033] (2) The fine grinding head and coarse grinding head in this invention can maintain the elasticity of the product, achieve one-time shaping and fine polishing, and the interface between the fine grinding head and the coarse grinding head also has good compatibility and no discontinuity phenomenon occurs.

[0034] (3) In this invention, liquid silicone rubber and solid silicone rubber are applied to the grinding head formulation. Due to the advantages of good fluidity and low vulcanization temperature, the material can provide elasticity to the grinding head, simplify the operation steps of processing dentures, and greatly reduce the processing cost of dentures.

[0035] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0036] Figure 1 It is a gourd-shaped silicone grinding head;

[0037] Figure 2 It is a parallel wheel-shaped silicone grinding head;

[0038] Figure 3 It is a bullet-shaped silicone grinding head;

[0039] Figure 4 It is a diamond-shaped silicone grinding head;

[0040] Figure 5 It is a spherical silicone grinding head;

[0041] Figure 6 It is an oval-shaped silicone grinding head.

[0042] In the diagram: 1. Fixed rod; 2. Coarse grinding head; 3. Fine grinding head. Detailed Implementation

[0043] The present invention will be further described below. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the present invention is not limited to this embodiment.

[0044] Examples 1-3

[0045] A special polishing dual-grit silicone grinding head is prepared from the components listed in Table 1.

[0046] The liquid silicone rubber prepared in Examples 1-3 was purchased from Shenzhen Yonghuisheng Import & Export Co., Ltd., model CHN-2003-60A / B, and the solid silicone rubber was purchased from Nanjing Luoen Silicon Materials Co., Ltd., model RBB-2030-80.

[0047] Table 1. Components of Examples 1-3 (unit: parts)

[0048]

[0049]

[0050]

[0051] The specific preparation process of alumina hollow glass microspheres is as follows:

[0052] Two parts of 100nm alumina nanoparticles, 25 parts of hollow glass microspheres, 10 parts of polyvinyl alcohol, and water were mixed to obtain a viscous substance with a water content of 20%. The viscous substance was granulated by a granulator, demolded, and then placed in an oven to dry at 120℃ for 4 hours to obtain alumina hollow glass microspheres.

[0053] The specific preparation method of coated abrasive is as follows:

[0054] Alumina and silicon carbide were mixed evenly at a mass ratio of 2:1, and then 15% KH550 silane coupling agent ethanol solution was added. After mixing evenly, the mixture was dried to obtain coated abrasive.

[0055] A method for preparing a dual-grit silicone polishing head for polishing includes the following steps:

[0056] (1) Weigh each raw material of the fine grinding head according to the proportion, and then mix them evenly to obtain the head slurry;

[0057] (2) Weigh each raw material of the coarse grinding head according to the proportion, and then mix them evenly to obtain the tail slurry;

[0058] (3) The tail slurry and head slurry are poured into the mold sequentially, heated and molded to obtain a dual-grain silicone grinding head. The heating and vulcanization temperature is 130℃, and the time is 2 hours. The finished silicone grinding head is gourd-shaped, see... Figure 1 .

[0059] Comparative Example 1

[0060] The difference from Example 1 is that the liquid silicone rubber was purchased from Shenzhen Yonghuisheng Import & Export Co., Ltd., model CHN-2003-25AB, with a Shore hardness of 27, an elongation at break of 900%, a tensile strength of 11.5 MPa, and a tear strength of 23 kN / m.

[0061] Comparative Example 2

[0062] The difference from Example 1 is that the liquid silicone rubber was purchased from Shenzhen Yonghuisheng Import & Export Co., Ltd., model CHN-2003-70AB, with a Shore hardness of 70, an elongation at break of 420%, a tensile strength of 9MPa, and a tear strength of 44kN / m.

[0063] Comparative Example 3

[0064] The difference from Example 1 is that the solid silicone rubber was purchased from Guangzhou Ruikehang Trading Co., Ltd., model TS-6360E, with a Shore hardness of A30.

[0065] Comparative Example 4

[0066] The difference from Example 1 is that the silicone oil viscosity is 10000 cps.

[0067] Comparative Example 5

[0068] The difference from Example 1 is that the median particle size of the titanium dioxide is 0.5 μm.

[0069] Comparative Example 6

[0070] The difference from Example 1 is that the alumina and hollow glass microspheres in the alumina hollow glass microspheres were directly added to the raw material of the coarse grinding head at a mass ratio of 2:25, without the granulation step.

[0071] Comparative Example 7

[0072] The difference from Example 1 is that the alumina and silicon carbide in the coated abrasive are directly mixed at a mass ratio of 1:2 and then added to the raw materials of the fine grinding head and the coarse grinding head without coupling agent treatment.

[0073] Comparative Example 8

[0074] The difference from Example 1 lies in the manufacturing process of the silicone tip. The specific method is as follows:

[0075] (1) Weigh each raw material of the fine grinding head according to the proportion, and then mix them evenly to obtain the head slurry;

[0076] (2) Weigh each raw material of the coarse grinding head according to the proportion, and then mix them evenly to obtain the tail slurry;

[0077] (3) Pour the tail slurry and the head slurry into two molds respectively, heat and press them to form grinding head one and grinding head two. The heating and vulcanization temperature is 130℃ and the time is 2h. Grinding head one is used for shaping and grinding head two is used for polishing.

[0078] Test case

[0079] The silicone grinding heads prepared in the examples and comparative examples were applied to denture polishing. First, a rod-shaped fixing bar was added to the bottom of the coarse grinding head to create a dental polishing tool. This dental polishing tool was used with a handheld polisher to shape and polish the denture. The shaping process was performed at a speed of 5000 rpm, and the polishing process was performed at a speed of 10000 rpm for 1 minute. When using the grinding head prepared in Comparative Example 8 for shaping and polishing, grinding head one was first installed on the handheld polisher to shape the denture, with the shaping parameters being the same as those in other comparative examples and examples. Then, grinding head two was installed on the handheld polisher to polish the denture, with the polishing parameters being the same as those in other examples and comparative examples. The denture polishing results are shown in Table 2.

[0080] Table 2. Results of denture polishing

[0081]

[0082]

[0083] Therefore, the present invention provides a polishing-specific dual-grit silicone grinding head with the above-mentioned structure and its preparation method, which combines two different grit sizes of fine and coarse grinding heads. The fine grinding head is used for fine polishing, and the coarse grinding head is used for rapid shaping, reducing the number of tool changes and improving processing efficiency. It also uses both liquid and solid silicone rubber, which helps to improve the elasticity and wear resistance of the grinding head.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dual-grit silicone polishing head for polishing, characterized in that: The dual-grit silicone abrasive head includes, from top to bottom, a fine abrasive head for fine polishing and a coarse abrasive head for rapid shaping; The fine grinding head is composed of the following raw materials in parts by weight: 100 parts of liquid silicone rubber 1-1.5 parts of vulcanizing agent 30-60 parts of titanium dioxide 20-40 parts zeolite powder 5-10 parts silicone oil 0.3-0.6 parts of vulcanization accelerator 60-100 parts of coated abrasive The coarse grinding head comprises the following raw materials in parts by weight: 20-40 parts of solid silicone rubber 60-80 parts of liquid silicone rubber 1-1.5 parts of vulcanizing agent 10-30 parts diatomaceous earth 10-30 parts of hollow alumina glass microspheres 5-10 parts silicone oil 0.3-0.6 parts of vulcanization accelerator 200-300 parts of coated abrasive; The coated abrasive is one or more of the following: alumina, silicon dioxide, silicon carbide, diamond, aluminum silicate powder, and pumice powder, after being treated with a coupling agent; the viscosity of the silicone oil is 3000-5000 cps; the alumina hollow glass microspheres are obtained by mixing alumina, hollow glass microspheres, polyvinyl alcohol, and water, followed by granulation and drying.

2. The polishing-specific dual-grit silicone grinding head according to claim 1, characterized in that: The liquid silicone rubber has a Shore hardness of 60, an elongation at break of 620%, a tensile strength of 11.4 MPa, and a tear strength of 43 kN / m.

3. The polishing-specific dual-grit silicone grinding head according to claim 1, characterized in that: The solid silicone rubber has a Shore hardness of A85, a tensile strength of 8.0 MPa, a tear strength of 15 kN / m, and an elongation of 90%.

4. The polishing-specific dual-grit silicone grinding head according to claim 1, characterized in that: The median particle size D50 of titanium dioxide is ≤1μm, the median particle size D50 of zeolite powder is ≤3μm, and the absolute value of the difference in median particle size between zeolite powder and titanium dioxide is not greater than 2μm.

5. A dual-grit silicone polishing head for polishing according to claim 1, characterized in that: Vulcanization accelerators include one or more of 1,1-di(trimethylsilyl)-3-(3-methoxyphenyl)thiourea, 1-allyl-3-[3-(triethoxysilyl)propyl]thiourea, 1-methylthioethyl mercaptan, and acetone dimethylhydrazone.

6. The polishing-specific dual-grit silicone grinding head according to claim 1, characterized in that: The particle size of diatomaceous earth is 15-50 μm.

7. The polishing-specific dual-grit silicone grinding head according to claim 1, characterized in that: The vulcanizing agent is one or more of sulfur, organic peroxides, and platinum vulcanizing agents.

8. A method for preparing a polishing-specific dual-grit silicone grinding head according to any one of claims 1-7, characterized in that: Includes the following steps: (1) Weigh each raw material of the fine grinding head according to the proportion, and then mix them evenly to obtain the head slurry; (2) Weigh each raw material of the coarse grinding head according to the proportion, and then mix them evenly to obtain the tail slurry; (3) Pour the tail slurry and the head slurry into the mold in sequence, heat and press to form a double-grained silicone grinding head.

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