Preparation method of low-temperature high-efficiency superfine sodium percarbonate particles used as denture cleaning agent

Abstract

The invention provides a preparation method of low-temperature efficient superfine sodium percarbonate particles used as an artificial tooth cleaning agent. The preparation method comprises the following steps: S1) preparing crystalline sodium percarbonate by a wet method; s2) coating modification with sodium percarbonate. The cleaning agent has the advantages that the active oxygen content is high, the low-temperature activation performance is improved, stains are quickly decomposed, the cleaning effect is improved, dryness is kept, and deliquescence inactivation is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of high-efficiency cleaning formulas for dental care, and in particular to a method for preparing low-temperature high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner. Background Art

[0002] Artificial teeth (dentures) are restorative devices used to replace lost natural teeth. Since dentures are foreign objects in the mouth and are in close contact with the gums, they are more likely to harbor dirt and breed bacteria than real teeth. Therefore, they need to be cleaned and sterilized regularly. If dentures are not cleaned properly, food residues remaining on the surface, grooves or metal hooks will form plaque, which will become a breeding ground for bacteria over time, causing caries, periodontal disease, bad breath, oral ulcers and other problems. In addition, some other pathogens attached to dentures may also enter the respiratory system through the oropharynx and cause bacterial pneumonia; or may enter the circulatory system, creating a risk of bacteremia in susceptible people.

[0003] At present, the commonly used denture cleaning methods include brushing dentures with toothpaste, tooth powder, detergent or soaking dentures with denture cleaners. Since most of the current dentures are made of metal bases and resin materials, the surface of dentures is not as hard as real teeth. Therefore, long-term use of ordinary toothpaste and tooth powder for brushing will form scratches on the surface of dentures. These scratches will increase the accumulation of bacteria and plaque, and the bactericidal ability is limited, which will increase the risk of infection for people who use dentures. However, dentures soaked in effervescent tablets of denture cleaners at room temperature generally have poor cleaning effects, and require long-term soaking or hot water soaking to improve the cleaning effect. Since detergents are generally alkaline or acidic, long-term soaking or hot water soaking will destroy the chemical structure of the denture material, causing the denture to deform and corrode the metal base of the denture, affecting the service life of the denture. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing low-temperature and high-efficiency ultrafine sodium percarbonate particles used as a denture cleaning agent, which has high active oxygen content, improves low-temperature activation performance, quickly decomposes stains, improves cleaning effect, maintains dryness, and avoids deliquescence inactivation.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solutions: A method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner comprises the following steps: S1) Preparation of crystalline sodium percarbonate by wet method At the same time, inject saturated sodium carbonate salt solution and hydrogen peroxide into the reactor, and directly react by rapid stirring at low temperature. The reaction temperature is 0-20°C, and the reaction time is 10-30 minutes, preferably 15-25 minutes. After filtration, ultrafine sodium percarbonate particle intermediates are obtained, and 8-15% of water is retained during filtration. S2) Sodium percarbonate coating modification The filtered intermediate wet product is put into a mixing kettle, and then a low-temperature activator, a bactericide, a coating adhesive and a desiccant are added in sequence into the mixing kettle, and stirred and mixed evenly to perform functional modification. The evenly mixed product is dried in a fluidized bed to obtain a low-temperature and high-efficiency ultrafine sodium percarbonate granule finished product.

[0006] Further, in step S2), the low temperature activator includes tetraacetylethylenediamine (TAED) and catalyst MnTACN, the mass percentage of tetraacetylethylenediamine (TAED) is 1-5% of the wet sodium percarbonate, and the mass percentage of catalyst MnTACN is 0.5-2% of the wet sodium percarbonate; the full name of catalyst MnTACN is tri-u-oxa-bis[(1,4,7-trimethyl-1,4,7-triazacyclononane)-manganese(IV)]-bis-hexafluorophosphate-monohydrate, and its molecular formula is .

[0007] Furthermore, in step S2), the bactericide is zinc citrate, and the mass percentage of zinc citrate is 1-2% of the wet sodium percarbonate product.

[0008] Furthermore, in step S2), the coating adhesive is polyvinyl pyrrolidone, the molecular weight of polyvinyl pyrrolidone is 1000-2000, and the mass percentage of polyvinyl pyrrolidone is 0.5-1.5% of the wet sodium percarbonate product.

[0009] Furthermore, in step S2), the desiccant is boric anhydride or acetic anhydride, and its mass percentage is 1-3% of the wet sodium percarbonate product.

[0010] Furthermore, in step S2), the functional modified auxiliary materials and additives of the low temperature activator, the bactericide, the coating adhesive and the desiccant are refined by mechanical force of pulverization to a particle size of 50-100 μm.

[0011] Furthermore, in step S2), the quality of the obtained sodium percarbonate finished product is as follows: active oxygen content ≥12.5%, particle size distribution is 150-300µm, thermal stability ≥70%, bulk density 500-1200g / L, and water content ≤0.5%.

[0012] Compared with the prior art, the present invention has the following advantages: The present invention discloses a method for preparing low-temperature and high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner, which has a high active oxygen content, improves low-temperature activation performance, quickly decomposes stains, enhances cleaning effects, maintains dryness, and avoids deliquescence and inactivation. Specifically, because high temperatures can easily cause deformation of dentures, the addition of a low-temperature activator allows sodium percarbonate, which originally has an ideal cleaning effect at temperatures above 40°C, to improve its oxygen release capacity in a low-temperature environment, making it easier to use room temperature water to soak and clean dentures; zinc citrate, as a bactericide, not only has a good effect of removing dental plaque, but can also be used as a zinc supplement without causing harm to the human body; polyvinyl pyrrolidone, as a water-soluble polymer surfactant, in addition to being an adhesive for coating excipients, can act as a coagulant in a dispersed system during use, has anti-fouling re-precipitation properties, and can be absorbed during the process of soaking dentures. The stains removed from the dentures are prevented from settling and accumulating on the dentures again; the addition of boric anhydride or acetic anhydride as a desiccant can effectively improve the stability of the sodium percarbonate cleaning product, reduce the risk of water absorption and deliquescence of sodium percarbonate during storage, and avoid the reduction of effective active oxygen content due to deliquescence of sodium percarbonate product particles. At the same time, boric anhydride or acetic anhydride, as an acidic oxide, reacts with water to become boric acid or acetic acid. In addition to playing a synergistic role in the sterilization of sodium percarbonate, it can also effectively neutralize and reduce the pH value of the sodium percarbonate aqueous solution, adjust the pH value of the denture cleaner soaking solution, and avoid damage to the metal base in the denture due to corrosion by the acid / alkaline cleaner soaking solution. DETAILED DESCRIPTION

[0013] The embodiments of the present invention are described in further detail below. Example 1

[0014] Step S1) 40 kg of hydrogen peroxide was mixed evenly with 1.8 kg of stabilizer, 30 kg of light anhydrous sodium carbonate, 1.6 kg of sodium chloride and 70 kg of water were mixed to prepare a soda ash salt solution, and then the soda ash salt solution and hydrogen peroxide solution were injected into the reactor together, the reaction temperature was controlled to be 5°C, and after reacting for 30 minutes, 43.5 kg of sodium percarbonate intermediate wet product with a water content of 8% was obtained by centrifugation.

[0015] Step S2) The intermediate wet product after centrifugation in step S1) is put into a mixing kettle, and 2 kg of crushed TAED and 40 g of catalyst MnTACN, 0.8 kg of zinc citrate, 0.6 kg of polyvinyl pyrrolidone, and 1.2 kg of boric anhydride are added in sequence for coating and functional modification. The modified sodium percarbonate is then dried in a fluidized bed at 110° C. for 2.5 h to obtain 44 kg of low-temperature and high-efficiency ultrafine sodium percarbonate granules. The quality indicators of the finished product are as follows: active oxygen content 12.8%, thermal stability 74%, bulk density 877 g / L, product particle size 266 µm, and moisture content 0.4%. Example 2

[0016] Step S1) 45 kg of hydrogen peroxide was mixed evenly with 2 kg of stabilizer, 30 kg of light anhydrous sodium carbonate, 1.8 kg of sodium chloride and 70 kg of water were mixed to prepare a soda salt solution, and then the alkali solution and hydrogen peroxide were injected into the reactor together, the reaction temperature was controlled to be 15 ° C, and after reacting for 25 minutes, 46.8 kg of sodium percarbonate intermediate wet product with a water content of 10% was obtained by centrifugation.

[0017] Step S2) The intermediate wet product after centrifugation in step S1) is put into a mixing kettle, and then 1.5 kg of crushed TAED and 15 g of catalyst MnTACN, 0.6 kg of zinc citrate, 0.69 kg of polyvinyl pyrrolidone and 1 kg of acetic anhydride are added in sequence for blending, coating and functional modification. The modified sodium percarbonate is then dried in a fluidized bed at 110° C. for 2.5 h to obtain 44.9 kg of low-temperature and high-efficiency ultrafine sodium percarbonate granules. The quality indicators of the finished product are as follows: active oxygen content 13.2%, thermal stability 71%, bulk density 500 g / L, product particle size 300 µm, and moisture content 0.3%. Example 3

[0018] Step S1) 50 kg of hydrogen peroxide was mixed evenly with 2.3 kg of stabilizer, 30 kg of light anhydrous sodium carbonate, 1.5 kg of sodium chloride and 70 kg of water were mixed to prepare a soda salt solution, and then the alkali solution and hydrogen peroxide were pumped into the reactor together, the reaction temperature was controlled to be 10°C, the reaction was carried out for 15 minutes, and 49 kg of sodium percarbonate intermediate wet product with a water content of 10% was obtained by centrifugation.

[0019] Step S2) The intermediate wet product after centrifugation in step S1) is put into a mixing kettle, and then 2.2 kg of crushed TAED and 40 g of catalyst MnTACN, 0.5 kg of zinc citrate, 0.6 kg of polyvinyl pyrrolidone and 1 kg of boric anhydride are added in sequence for blending, coating and functional modification. The modified sodium percarbonate is dried at 110° C. for 2.5 h in a fluidized bed to obtain 47.3 kg of low-temperature and high-efficiency ultrafine sodium percarbonate particles. The quality indicators of the finished product are as follows: active oxygen content 12.5%, thermal stability 77%, bulk density 1200 g / L, product particle size 150 µm, and moisture content 0.5%. Example 4

[0020] Step S1) 40 kg of hydrogen peroxide was mixed evenly with 1.8 kg of stabilizer, 30 kg of light anhydrous sodium carbonate, 1.5 kg of sodium chloride and 70 kg of water were mixed to prepare a soda salt solution, and then the alkali solution and hydrogen peroxide were injected into the reactor together, the reaction temperature was controlled to be 10°C, the reaction was carried out for 15 minutes, and 47 kg of sodium percarbonate intermediate wet product with a water content of 10% was obtained by centrifugation.

[0021] Step S2) The intermediate wet product after centrifugation in step S1) is put into a mixing kettle, and then 2kg TAED, 0.8kg zinc citrate, 0.6kg polyvinyl pyrrolidone and 1.2kg boric anhydride are added in sequence for blending, coating and functional modification. The modified sodium percarbonate is dried at 110°C in a fluidized bed for 2.5h to obtain 42.6kg low-temperature and high-efficiency ultrafine sodium percarbonate granules. The quality indicators of the finished product are as follows: active oxygen content 12.6%, thermal stability 76%, bulk density 920 g / L, product particle size 220µm, and moisture content 0.5%.

[0022] Different from the above-mentioned Examples 1 to 3, in Example 4, no catalyst MnTACN is added.

[0023] The cleaning effect tests and comparisons were conducted on the low-temperature, high-efficiency, ultrafine sodium percarbonate granule products obtained in Examples 1 to 4. The test methods are as follows: First, four clean dentures were selected, and the initial mass of the dentures was recorded as m0. Then, the same amount of physical residues with the same properties were evenly coated on the dentures and left to stand for 4 hours. Then, 3 g of the cleaning agents prepared in Example 1, Example 2, Example 3, and Example 4 were respectively dissolved in 200 ml of tap water to prepare four cups of cleaning and soaking liquid; Finally, the four cups of cleaning and soaking solution were kept warm at 20°C, and then the stained dentures were immersed in the four cups of cleaning and soaking solution respectively. After 15 minutes, the dentures were taken out and left to stand for 4 hours until there was no moisture on the surface of the dentures. Their masses were weighed and recorded as m1, m2, m3, and m4 respectively.

[0024] The calculation formula of the decontamination rate is as follows: Decontamination rate = [m i -m0]÷m0×100%; where i=1, 2, 3, 4.

[0025] According to the above test method, the cleaning effects were compared at water temperatures of 10°C, 20°C, and 30°C, as shown in Table 1.

[0026] Table 1 Water temperature / ℃ Example 1 Decontamination rate / % Example 2 Decontamination rate / % Example 3 Decontamination rate / % Example 4 Decontamination Rate / % 10 99.4 99.6 99.5 83.6 20 100 99.8 100 88.2 30 99.9 100 100 92.7 Based on the visual inspection of the cleaning process, the stain removal time was recorded as shown in Table 2 below.

[0027] Table 2 Example 5min 10min 15min Example 1 Dissolves large stains Stains are basically dissolved Stains are completely dissolved Example 2 Dissolves large stains Stains are basically dissolved Stains are completely dissolved Example 3 Dissolves large stains Stains are basically dissolved Stains are completely dissolved Example 4 Some stains dissolved There are also large stains Stains are basically dissolved In summary, as shown in Tables 1 and 2, it is clear that the cleaning effect of the sodium percarbonate product obtained in Example 4 without adding the catalyst MnTACN is not good. It can be seen that the auxiliary effect of the catalyst MnTACN on the low-temperature activator cannot be underestimated.

[0028] The above description is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the concept of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner, characterized in that The steps include: S1) Preparation of crystalline sodium percarbonate by wet method At the same time, a saturated sodium carbonate salt solution and hydrogen peroxide are injected into a reaction kettle, and the mixture is stirred and reacted at low temperature and rapidly, and ultrafine sodium percarbonate particle intermediates are obtained after filtration. S2) Sodium percarbonate coating modification The filtered intermediate wet product is put into a mixing kettle, and then a low-temperature activator, a bactericide, a coating adhesive and a desiccant are added in sequence into the mixing kettle, and stirred and mixed evenly to perform functional modification. The evenly mixed product is dried in a fluidized bed to obtain a low-temperature and high-efficiency ultrafine sodium percarbonate granule finished product.

2. A method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the low temperature activator comprises tetraacetylethylenediamine and catalyst MnTACN, the mass percentage of tetraacetylethylenediamine is 1-5% of the wet sodium percarbonate product, and the mass percentage of catalyst MnTACN is 0.5-2% of the wet sodium percarbonate product.

3. The method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the bactericide is zinc citrate, and the mass percentage of zinc citrate is 1-2% of the wet sodium percarbonate product.

4. The method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the coating adhesive is polyvinyl pyrrolidone, the molecular weight of polyvinyl pyrrolidone is 1000-2000, and the mass percentage of polyvinyl pyrrolidone is 0.5-1.5% of the wet sodium percarbonate product.

5. The method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the desiccant is boric anhydride or acetic anhydride, and its mass percentage is 1-3% of the wet sodium percarbonate product.

6. The method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the functional modified auxiliary materials and additives of the low temperature activator, the bactericide, the coating adhesive and the desiccant are refined by mechanical force of pulverization to a particle size of 50-100 μm.

7. The method for preparing low-temperature, high-efficiency ultrafine sodium percarbonate particles used as a denture cleaner according to claim 1, characterized in that: In step S2), the quality of the obtained sodium percarbonate finished product is as follows: active oxygen content ≥12.5%, particle size distribution is 150-300µm, thermal stability ≥70%, bulk density is 500-1200g / L, and water content is ≤0.5%.