Colorant preparation method based on waste ammonia water generated by board smoking process and colorant

Abstract

The invention belongs to the field of colorant preparation, and particularly relates to a preparation method of a colorant based on waste ammonia water generated by a board smoking process and the colorant, and the preparation method of the colorant comprises the following steps: S1, adjusting the pH value of the waste ammonia water to 7-8; s2, adding starch into the waste ammonia water obtained in the step S1, and uniformly stirring; s3, maintaining the waste ammonia water obtained in S2 for a period of time at the temperature of 35-55 DEG C and the pressure of 1.5-3 MPa; s4, adding an acrylic acid-acrylamide copolymer into the waste ammonia water obtained in S3, and uniformly stirring; and S5, adding a color concentrate into the waste ammonia water obtained in the step S4, and uniformly stirring to obtain the coloring agent. According to the preparation method provided by the invention, waste ammonia water generated by an ammonia fumigation process is utilized, and the obtained coloring agent not only has excellent adhesive force, but also is high in color intensity and high in color purity.

Description

Technical Field

[0001] The invention belongs to the field of colorant preparation, and specifically relates to a colorant preparation method, in particular to a colorant preparation method based on waste ammonia water generated by a board fumigation process and a colorant. Background Art

[0002] The ammonia fumigation process for floors is a special treatment of the floor. It uses ammonia water to contact the board and react with lignin, tannin and other substances in the board. The ammonia molecules combine with the phenolic hydroxyl groups in the tannic acid to form a relatively stable complex. This complexation changes the color of the wood, usually showing a light brown or dark brown color with a smoked effect. At the same time, the complexation reaction also affects the surface texture of the wood, making its texture clearer, increasing the beauty of the wood, and giving the wood a unique smoked appearance and texture.

[0003] However, the remaining ammonia after volatilization cannot be reused, resulting in a large amount of waste ammonia. Alkaline ammonia cannot be discharged at will, as it will damage water bodies and soil.

[0004] Therefore, before this, the invention patent with publication number CN114210248A provided a method for preparing a colorant made from waste ammonia water and its mixing device for the above-mentioned problem. The waste ammonia water produced by the fumigation process was used, and a thickener polyamide salt and a pure water-based adhesion promoter were added. The polyamide salt was used as a pure water-based active thickener, which facilitated the subsequent regulation of the coating amount on the equipment, making the coating of the colorant on the board more uniform, improving permeability and increasing storage time.

[0005] After actual use, it was found that the above-mentioned colorants had problems such as poor color intensity and insufficient substrate during use, and these properties need to be further improved. Summary of the invention

[0006] In order to solve the above-mentioned problems existing in the preparation of colorants using waste ammonia water, the present invention provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process.

[0007] The present invention adopts the following technical solution: The method for preparing a colorant based on waste ammonia water generated by a board fumigation process comprises the following steps: S1. Adjust the pH of the waste ammonia water to between 7 and 8; S2. Add starch to the waste ammonia obtained in S1 and stir evenly; S3. The waste ammonia solution obtained in S2 is maintained at a temperature of 35°C to 55°C and a pressure of 1.5MPa to 3MPa for a period of time; S4 S3 to the waste ammonia obtained by adding acrylic acid - acrylamide copolymer, stirring; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain a colorant.

[0008] In the face of the problems mentioned in the background art of using waste ammonia water produced by the ammonia fumigation process to prepare colorants, the inventors tried to adjust some reaction conditions, such as adjusting the pH of the waste ammonia water, the temperature of the waste ammonia water, etc., but did not achieve the desired effect. They also tried to adjust the amount of thickener and adhesion promoter added, but still did not get satisfactory results. The inventors also tried to use different thickeners and adhesion promoters, but the problem of coloring power of the colorant was not solved.

[0009] In the subsequent experiments, it was found that the coloring power of the colorant was very strong before the adhesion promoter was added, but at this time, due to the absence of the adhesion promoter, the adhesion of the colorant was extremely poor. However, once the adhesion promoter was added, the coloring power dropped significantly. Therefore, the inventors inferred that the problem of poor coloring power caused by the use of waste ammonia water to prepare the colorant may be caused by the adhesion promoter.

[0010] In subsequent experiments, the inventors focused on verifying the above inference and tried to solve this problem, which resulted in the above technical solution of the present invention.

[0011] The above scheme of the present invention has at least three key features. First, the addition of adhesion promoter is abandoned and starch is added before the thickener is added; second, after the starch is added, a specific temperature and pressure treatment is performed; third, acrylic acid-acrylamide copolymer is selected instead of polyamide salt as the thickener.

[0012] The present invention utilizes starch to improve the adhesion of the colorant to a certain extent. After the process of step S3, the defect of insufficient adhesion caused by not adding an adhesion promoter can be compensated, while avoiding the negative effect of adding an adhesion promoter on the tinting power. At the same time, the present invention also uses acrylic acid-acrylamide copolymer instead of polyamide salt as a thickener. Compared with the use of polyamide salt, it has a better thickening effect in the system. Moreover, under the action of acrylic acid-acrylamide copolymer, the adhesion effect of starch on the colorant can be improved, further improving the tinting power and stability of the colorant.

[0013] Preferably, the amount of starch added is 12 g to 18 g per liter of waste ammonia water.

[0014] Preferably, the holding time in step S3 is 35 min to 45 min.

[0015] Preferably, the acrylic acid-acrylamide copolymer is added in an amount of 0.1 kg to 0.6 kg per liter of waste ammonia water.

[0016] Preferably, in step S4, the operating temperature is set at 30°C to 35°C.

[0017] Preferably, in step S4, the stirring speed is 150 rpm to 300 rpm.

[0018] The present invention also provides a colorant obtained by the above preparation method.

[0019] By implementing the above technical solution, compared with the prior art, the present invention has the following beneficial effects: The preparation method provided by the present invention utilizes waste ammonia water produced by an ammonia fumigation process to obtain a colorant which not only has excellent adhesion but also has high color intensity and high color purity. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 This embodiment provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Take 500 liters of waste ammonia water and adjust the pH of the waste ammonia water to 7; S2 S1 to the waste ammonia obtained by adding 6kg starch, 300rpm stirring; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 50°C and a pressure of 1.5MPa for a period of time; S4. Add 50 kg of acrylic acid-acrylamide copolymer to the waste ammonia obtained in S3 and stir evenly at 300 rpm (at room temperature 24 ° C); S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 1.

[0022] Example 2 This embodiment provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7; S2 S1 to the waste ammonia obtained by adding 7.5kg starch, 300rpm stirring; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 45°C and a pressure of 2.5 MPa for a period of time; S4. Add 250 kg of acrylic acid-acrylamide copolymer to the waste ammonia obtained in S3 and stir evenly at 250 rpm (at room temperature 24 ° C); S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 2.

[0023] Example 3 This embodiment provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2 S1 to the waste ammonia obtained by adding 9kg starch, 300rpm stirring; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 35°C and a pressure of 2.0MPa for a period of time; S4. Add 300 kg of acrylic acid-acrylamide copolymer to the waste ammonia obtained in S3 and stir evenly at 150 rpm (at room temperature 24 ° C); S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 3.

[0024] Example 4 This embodiment provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2 S1 to the waste ammonia obtained by adding 9kg starch, 300rpm stirring; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 35°C and a pressure of 2.0MPa for a period of time; S4 was added to the waste ammonia obtained in S3 300kg acrylic acid - acrylamide copolymer, maintaining the temperature at 30 ℃, 150rpm stirring; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 4.

[0025] Example 5 This embodiment provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2 was added to the waste ammonia obtained in S1 8kg starch, stirring at 300rpm; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 35°C and a pressure of 2.0MPa for a period of time; S4 was added to the waste ammonia obtained in S3 150kg acrylic acid - acrylamide copolymer, maintaining the temperature at 30 ℃, 150rpm stirring; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 5.

[0026] Comparative Example 1 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2. Add 20% polyamide salt of the waste ammonia water to the waste ammonia water by mass and stir evenly at 300rpm; S3. Add 10% of the mass of the waste ammonia obtained in S2 to the waste ammonia and stir until completely compatible; S4. Filter out the foam on the surface of the solution prepared in S3; S5. Add color concentrate to the solution prepared in S4 to prepare an active water-based colorant of the desired color, and place it at room temperature for 24 hours to complete the preparation of the active water-based colorant to obtain colorant No. 6.

[0027] Comparative Example 2 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Take 500 liters of waste ammonia water and adjust the pH of the waste ammonia water to 7; S2 S1 to the waste ammonia obtained by adding 6kg starch, 300rpm stirring; S3. Add 50 kg of acrylic acid-acrylamide copolymer to the waste ammonia obtained in S2 and stir evenly at 300 rpm (at room temperature 24 ° C); S4. Add color concentrate to the waste ammonia water obtained in S3 and stir evenly to obtain colorant No. 7.

[0028] Comparative Example 3 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Take 500 liters of waste ammonia water and adjust the pH of the waste ammonia water to 7; S2 S1 to the waste ammonia obtained by adding 6kg starch, 300rpm stirring; S3 was added to the waste ammonia obtained in S2 50kg acrylic acid - acrylamide copolymer, maintaining the temperature at 30 ℃, stirring at 300rpm; S4. Add color concentrate to the waste ammonia water obtained in S3 and stir evenly to obtain colorant No. 8.

[0029] Comparative Example 4 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2. Add 20% of the mass of the waste ammonia water to the waste ammonia water in the waste ammonia water - acrylic acid - acrylamide copolymer and stir evenly at 300rpm; S3. Add 10% of the mass of the waste ammonia obtained in S2 to the waste ammonia and stir until completely compatible; S4. Filter out the foam on the surface of the solution prepared in S3; S5. Add color concentrate to the solution prepared in S4 to prepare an active water-based colorant of the desired color, and place it at room temperature for 24 hours to complete the preparation of the active water-based colorant to obtain colorant No. 9.

[0030] Comparative Example 5 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2 S1 to the waste ammonia obtained by adding 9kg starch, 300rpm stirring; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 35°C and a pressure of 2.0MPa for a period of time; S4. Add 300kg of polyamide salt to the waste ammonia obtained in S3, maintain the temperature at 30 ° C, and stir evenly at 150rpm; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 10.

[0031] Comparative Example 6 This comparative example provides a method for preparing a colorant based on waste ammonia water generated by a board fumigation process, comprising the following steps: S1. Adjust the pH of the waste ammonia water to 7.5; S2 was added to the waste ammonia obtained in S1 9kg adhesion promoter, stirring at 300rpm; S3. The waste ammonia water obtained in S2 is maintained at a temperature of 35°C and a pressure of 2.0MPa for a period of time; S4 was added to the waste ammonia obtained in S3 300kg acrylic acid - acrylamide copolymer, maintaining the temperature at 30 ℃, 150rpm stirring; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain colorant No. 11.

[0032] The colorants obtained in the above-mentioned embodiments and comparative examples were tested for relevant properties.

[0033] Method: Apply PU clear primer twice on the surface of the board, apply colorant by brush, and test its coloring adhesion performance after 1 hour.

[0034] The tinting strength is tested according to the method in GB1708-79.

[0035] The test items and test results are shown in Table 1.

[0036] Colorants Adhesion Relative tinting strength (%) Example 1-1 5B 106 Example 2-2 5B 108 Example 3-3 5B 103 Example 4-4 5B 119 Example 5-5 5B 138 Comparative Examples 1-6 4B 53 Comparative Examples 2-7 2B 86 Comparative Examples 3-8 3B 77 Comparative Examples 4-9 5B 59 Comparative Examples 5-10 4B 67 Comparative Examples 6-11 3B 60

Claims

1. A method for preparing a colorant based on waste ammonia water produced by a board fumigation process, characterized in that: The steps include: S1. Adjust the pH of the waste ammonia water to between 7 and 8; S2. Add starch to the waste ammonia obtained in S1 and stir evenly; S3. The waste ammonia solution obtained in S2 is maintained at a temperature of 35°C to 55°C and a pressure of 1.5MPa to 3MPa for a period of time; S4 S3 to the waste ammonia obtained by adding acrylic acid - acrylamide copolymer, stirring; S5. Add color concentrate to the waste ammonia water obtained in S4 and stir evenly to obtain a colorant.

2. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: The amount of starch added is 12 g to 18 g per liter of waste ammonia water.

3. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: The holding time in step S3 is 35 min to 45 min.

4. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: The amount of the acrylic acid-acrylamide copolymer added is 0.1 kg to 0.6 kg per liter of waste ammonia water.

5. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: In step S4, the operating temperature is set at 30°C to 35°C.

6. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: In step S4, the stirring speed is 150 rpm to 300 rpm.

7. The method for preparing a colorant based on waste ammonia water generated by the board fumigation process according to claim 1, characterized in that: The amount of starch added is 16 g per liter of waste ammonia water, and the amount of acrylic acid-acrylamide copolymer added is 0.3 kg per liter of waste ammonia water.

8. A colorant, characterized in that The colorant is obtained by the method for preparing the colorant based on waste ammonia water produced by the board fumigation process as described in any one of claims 1 to 7.