Preparation method of high-solid low-viscosity peach gum solution for gouache

Abstract

The invention relates to a preparation method of a high-solid low-viscosity peach gum solution for gouache. The preparation method is characterized by comprising the following steps: (1) soaking solid peach gum in water; (2) adding a hydrogen peroxide solution until the pH value is 6-7, heating, and stirring until the solid peach gum is completely dissolved to obtain a first treatment solution; (3) adding a sodium hydroxide solution into the first treatment solution to obtain a second treatment solution; (4) adding a hydrogen peroxide solution into the second treatment solution, stirring and bleaching, and then removing impurities through precipitation to obtain a third treatment solution; (5) cooling the third treatment liquid to 30-60 DEG C, then adding catalase into the third treatment liquid, uniformly stirring, and removing redundant hydrogen peroxide; and (6) settling, and taking an upper-layer solution, thereby obtaining the high-solid low-viscosity peach gum solution for gouache. When the peach gum solution with high concentration and moderate viscosity is applied to gouache, the hand feeling of drawing is good.

Description

Technical Field

[0001] The invention relates to a painting pigment additive, in particular to a preparation method of a peach gum additive for gouache pigment. Background Art

[0002] The original peach gum is a solid substance secreted by the trunks of Rosaceae plants such as peach or mountain peach and air-dried on the trunks. It is a translucent solid block with a pink or light yellow to yellowish brown color and a smooth appearance. The main component of peach gum is polysaccharide, which contains a small amount of protein and impurities. Its polysaccharide composition includes galactose, rhamnose, arabinose, glucuronic acid, etc. The composition and properties of peach gum polysaccharide are very similar to those of gum arabic. Peach gum has no toxic effects on humans and animals, has high edible and medicinal value, and is widely used in pigments, cosmetics, printing and dyeing, electronics and other industries. Compared with natural colloids such as gum arabic, commercial peach gum is cheaper and is an ideal substitute for gum arabic.

[0003] Raw peach gum is difficult to dissolve in water and has a high viscosity, so it cannot be used directly. Therefore, raw peach gum itself has no industrial application value and is only used for medicinal purposes. In recent years, with the improvement of people's living standards, more and more attention has been paid to the quality and safety of painting pigments, especially gouache pigments, which are used on a large scale in China as pigments for art examinations. Peach gum is a natural colloid and is cheaper than gum arabic. It is increasingly widely used in the production of pigments.

[0004] However, many existing peach gum solutions have the disadvantages of poor solubility, high viscosity, low transparency, etc., and generally have complex production processes, high production costs, and are not easy to mass produce.

[0005] To this end, a preparation process of peach gum is disclosed in the prior art, see the Chinese invention patent "Peach Gum Liquid and Preparation Method thereof" with patent number ZL 201810301130.7 (authorization announcement number CN108329738B). The patent first uses triethanolamine to adjust the pH to 9-10 to protect the high molecular weight polysaccharides in the peach gum particles, but this will cause the peach gum to be difficult to decompose, and the dissolved peach gum solution has too much high molecular weight, resulting in excessive viscosity; in addition, the viscosity of the peach gum solution is 3000-3200 CPS (mpa.s). If this peach gum solution is applied to gouache paint, due to the excessive viscosity, the gouache cannot drag the pen, the painting is very short, the painting is not smooth enough, and the feel is poor. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing a high-solid and low-viscosity peach gum solution for gouache pigment in view of the above technical status.

[0007] The technical solution adopted by the present invention to solve the above technical problems is: a method for preparing a high-solid and low-viscosity peach gum solution for gouache pigment, characterized by comprising the following steps:

[0008] ① Soak the solid peach gum in water;

[0009] ② Add hydrogen peroxide solution until the pH is 6-7, then heat and stir until the solid peach gum is completely dissolved to obtain the first treated liquid;

[0010] ③ adding sodium hydroxide solution to the first treatment liquid to obtain a second treatment liquid;

[0011] ④ Adding hydrogen peroxide solution to the second treatment liquid and stirring for bleaching, and then removing impurities through precipitation to obtain a third treatment liquid;

[0012] ⑤ Cool the third treatment solution to 30-60°C, then add catalase to it, stir evenly, and remove excess hydrogen peroxide.

[0013] ⑥ Settle and take the upper solution to obtain a high-solid and low-viscosity peach gum solution for gouache pigment.

[0014] Preferably, in step ①, the weight ratio of solid peach gum to water satisfies 1:2-6.

[0015] Preferably, the soaking time in step ① is 24 to 36 hours.

[0016] Preferably, the soaking water temperature in step ① is room temperature, generally 20-30° C., and the temperature is raised to 90-140° C. in step ②.

[0017] Preferably, the mass percentage concentration of the hydrogen peroxide solution is 30-40%, and the amount of hydrogen peroxide added is 0.5‰-3‰ of the weight of the prepared solution.

[0018] Preferably, the mass percentage concentration of the sodium hydroxide solution in step ③ is 3-10%, and the amount of sodium hydroxide added is 5-20% of the mass of the solid peach gum. Too high a concentration of the sodium hydroxide solution can easily lead to an excessively high pH value of the peach gum solution, which in turn leads to an excessive amount of hydrogen peroxide solution added in the subsequent bleaching process, and is prone to over-bleaching problems, which on the one hand causes the finished peach gum solution to have a taste; on the other hand, it can cause the viscosity of the peach gum solution to decrease.

[0019] Preferably, the pH value after adding sodium hydroxide solution in step ③ is 11-12.

[0020] Preferably, in step ④, the bleaching temperature is controlled at 75-95° C., and the pH value is adjusted to 7-8 by adding hydrogen peroxide solution.

[0021] Preferably, the activity of the catalase in step ④ is 100,000 U to 300,000 U, and the hydrogen peroxide solution added in step ④ accounts for 0.5 to 6% of the weight.

[0022] The high-solid and low-viscosity peach gum solution for gouache pigment obtained in step ④ has a solid content of 20-55% and a viscosity of 500-700 mpas.

[0023] Compared with the prior art, the advantages of the present invention are: the present invention directly uses hydrogen peroxide to adjust the pH, and since hydrogen peroxide is weakly acidic, it can promote the dissolution of solid peach gum; at the same time, the polysaccharides in the peach gum can be decomposed into polysaccharides with smaller molecular weight under the action of hydrogen peroxide, and then dissolved in water to form a peach gum solution.

[0024] By using the best process, i.e. without the need for alkali protection, at a suitable temperature and with the addition of a proper amount of hydrogen peroxide, a peach gum solution with a high concentration and a moderate viscosity can be obtained; the best viscosity of the peach gum solution obtained by the present invention is between 500 and 700 mpa.s, and the gouache painting with this viscosity has a good feel.

[0025] The high-solid and low-viscosity peach gum solution of the present invention has a good moisturizing effect. Since the peach gum solution has a high solid content, it has good adhesion; the peach gum solution has a low viscosity, has a better feel and does not stick to the pen. Therefore, in the field of painting pigments, the gouache pigment prepared by the peach gum solution has the characteristics of being less likely to crack, having a better painting feel, and being less likely to separate water in the gouache with the same addition amount ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a photo of the peach gum solution test in Example 1.

[0027] Figure 2 This is a photo of the peach gum solution test of Example 2.

[0028] Figure 3 This is a photo of the peach gum solution test in Example 3.

[0029] Figure 4 This is a photo of the peach gum solution test of Example 4.

[0030] Figure 5 This is a photograph of the product of Example 5.

[0031] Figure 6 This is a photograph of the product of Example 6.

[0032] Figure 7 This is a photograph of the product of Example 7.

[0033] Figure 8 This is a test diagram of commercially available peach gum solution 1.

[0034] Fig. 9 The gouache pigment (light gray blue) prepared by the peach gum solution of Example 4 is adopted.

[0035] Fig.10 It is a gouache pigment (light gray blue) prepared using commercially available peach gum solution 1.

[0036] Fig.11 The scraper picture of the light gray blue gouache prepared by the peach gum solution of Example 4

[0037] Fig.12 It is a scraperboard drawing of light gray-blue gouache prepared using commercially available peach gum solution 1.

[0038] Fig.13 The gouache pigment (orange) prepared by adopting the peach gum solution of Example 4.

[0039] Fig.14 It is a gouache pigment (orange) prepared from commercially available peach gum solution 1.

[0040] Fig.15 It is a scraper picture of the orange gouache prepared by the peach gum solution of Example 4.

[0041] Fig.16 This is a scraper picture of the orange gouache prepared by purchasing and selling peach gum solution 1.

[0042] Fig.17 This is a test diagram of commercially available peach gum solution 2.

[0043] Fig.18 The gouache pigment (Spring Blue) prepared by the peach gum solution of Example 4 is used.

[0044] Fig.19 It is a gouache pigment (Spring Blue) prepared using commercially available peach gum solution 2. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below with reference to the accompanying drawings.

[0046] Example 1: 50 kg of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative were put into a container, and then 100 kg of deionized water was added thereto, and the mixture was soaked for 48 hours for later use.

[0047] The soaked peach gum particles are added into a 500kg reactor, and then the temperature of the reactor is adjusted to 135°C, and the heating and stirring buttons are turned on, and the electric heater is used for heating; when the temperature rises to 135°C, stir for about 1h, and then start adding 35% hydrogen peroxide solution, the amount of hydrogen peroxide added is 75g, the pH is adjusted to about 6-7, and the temperature is maintained at 110°C.

[0048] After stirring for about 14 hours, the peach gum particles are completely dissolved. After the peach gum solution is completely cooled, filter and release the material to remove impurities such as branches.

[0049] Pour the cooled peach gum solution into another reactor, adjust the temperature of the reactor to 90°C, turn on the heating and stirring buttons, and when the temperature reaches 90°C, add 5% sodium peroxide solution in an amount of 5kg, adjust the pH of the peach gum solution to between 11-12, and slowly add 35% hydrogen peroxide solution for bleaching. At this time, a violent reaction and a large amount of gas foam will occur in the reactor. When the pH is adjusted to 7-8, stop adding hydrogen peroxide solution, the amount of hydrogen peroxide solution added is 1.25kg, and stop stirring after stirring for 120 minutes. Settle for 24 hours, and take the clear liquid as the prepared peach gum solution.

[0050] Test items Embodiment 4 peach gum solution Preparation of peach gum solution 55％ Preparation of peach gum solution viscosity 2588mpas Preparation of peach gum solution transparency 6.6％

[0051] Test chart see Figure 1 shown.

[0052] Example 2: 20 kg of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative were placed in a container, and then 120 kg of deionized water was added thereto, and the mixture was soaked for 36 hours for later use.

[0053] The soaked peach gum particles are added into a 500kg reactor, and then the temperature of the reactor is adjusted to 135°C, and the heating and stirring buttons are turned on, and the electric heater is used for heating; when the temperature rises to 135°C, stirring is carried out for about 1h, and then a hydrogen peroxide solution with a mass concentration of 35% is added thereto, and the addition amount of the hydrogen peroxide solution is 350g, the pH is adjusted to about 6-7, and the temperature is maintained at 135°C.

[0054] After stirring for about 7.5 hours, the peach gum particles are completely dissolved. After the peach gum solution is completely cooled, filter and release the material to remove impurities such as branches.

[0055] Pour the cooled peach gum solution into another reactor, adjust the temperature of the reactor to 90°C, turn on the heating and stirring buttons, and when the temperature reaches 90°C, add 5% sodium hydroxide solution in an amount of 3kg, adjust the pH of the peach gum solution to between 11-12, and slowly add 35% hydrogen peroxide for bleaching. At this time, a violent reaction and a large amount of gas foam will occur in the reactor. When the pH is adjusted to 7-8, stop adding hydrogen peroxide, the amount of hydrogen peroxide added is 600g, and stop stirring after stirring for 120 minutes. Settle for 24h, and take the clear liquid as the prepared peach gum solution.

[0056]

[0057]

[0058] Test chart see Figure 2 shown.

[0059] Example 3: 25 kg of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative were placed in a container, and then 125 kg of deionized water was added thereto, and the mixture was soaked for 36 hours for later use.

[0060] The soaked peach gum particles are added into a 500kg reactor, and then the temperature of the reactor is adjusted to 110°C, and the heating and stirring buttons are turned on, and the electric heater is used for heating; when the temperature rises to 110°C, stir for about 1h, and then start adding 35% hydrogen peroxide solution, the addition amount of hydrogen peroxide solution is 675g, the pH is adjusted to about 6-7, and the temperature is maintained at 110°C.

[0061] After stirring for about 7 hours, the peach gum particles are completely dissolved. After the peach gum solution is completely cooled, filter and release the material to remove impurities such as branches.

[0062] Pour the cooled peach gum solution into another reactor, adjust the temperature of the reactor to 90°C, turn on the heating and stirring buttons, and when the temperature reaches 90°C, add 5% sodium peroxide solution in an amount of 3.75kg, adjust the pH of the peach gum solution to between 11-12, and slowly add 35% hydrogen peroxide solution for bleaching. At this time, a violent reaction and a large amount of gas foam will occur in the reactor. When the pH is adjusted to 7-8, stop adding hydrogen peroxide solution, and the amount of 35% hydrogen peroxide solution is 750g. Stop stirring after stirring for 120 minutes. Settle for 24 hours, and take the clear liquid as the prepared peach gum solution.

[0063] Test items Embodiment 2 peach gum solution Preparation of peach gum solution 25％ Preparation of peach gum solution viscosity 271mpas Preparation of peach gum solution transparency 9.3％

[0064] Test chart see Figure 3 shown.

[0065] Example 4: 25 kg of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative were placed in a container, and then 100 kg of deionized water was added thereto, and the mixture was soaked for 36 hours for later use.

[0066] The soaked peach gum particles are added into a 500kg reactor, and then the temperature of the reactor is adjusted to 110°C, and the heating and stirring buttons are turned on, and the electric heater is used for heating; when the temperature rises to 110°C, stir for about 1h, and then start adding 35% hydrogen peroxide solution, the addition amount of hydrogen peroxide solution is 312.5g, adjust the pH to about 6-7, and keep the temperature at 110 degrees Celsius.

[0067] After stirring for about 8 hours, the peach gum particles are completely dissolved. After the peach gum solution is completely cooled, filter and release the material to remove impurities such as branches.

[0068] Pour the cooled peach gum solution into another reactor, adjust the temperature of the reactor to 90°C, turn on the heating and stirring buttons, and when the temperature reaches 90°C, add 5% sodium peroxide solution in an amount of 3.75kg, adjust the pH of the peach gum solution to between 11-12, and slowly add 35% hydrogen peroxide solution for bleaching. At this time, a violent reaction and a large amount of gas foam will occur in the reactor. When the pH is adjusted to 7-8, stop adding hydrogen peroxide in an amount of 700g, and stop stirring after stirring for 120 minutes. Settle for 24h, and take the clear liquid as the prepared peach gum solution.

[0069] Test items Embodiment 3 peach gum solution Preparation of peach gum solution 30％ Preparation of peach gum solution viscosity 509mpa.s Preparation of peach gum solution transparency 13.6％

[0070] Test chart see Figure 4 shown.

[0071] Example 5, the weight ratio of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative to water foam is 1:4, the dissolution temperature is 110°C, the weight percentage of hydrogen peroxide is 35%, the addition amount is 0.5‰, the dissolution time is 14 hours, and other conditions refer to Example 1. The test results: the peach gum cannot be completely dissolved, and there are obvious sticky particles. The reason for the analysis is that the amount of hydrogen peroxide added is insufficient. The product is shown in Figure 5 shown.

[0072] Example 6, the weight ratio of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative to water foam is 1:4, the dissolution temperature is 90°C, the weight percentage of 35% hydrogen peroxide is added in an amount of 3‰, the dissolution time is 15 hours, and other conditions refer to Example 1. The test results show that the peach gum cannot be completely dissolved and presents a paste-like viscous liquid. The reason for the analysis is that the dissolution temperature is too low. See the product Figure 6 shown.

[0073] Example 7, the weight ratio of peach gum particles purchased from Jinhua Jimin Peach Gum Professional Cooperative to water foam is 1:2, the dissolution temperature is 90°C, the weight percentage is 35%, the amount of hydrogen peroxide added is 0.5‰, the dissolution time is 15 hours, and the other conditions refer to Example 1. The test results: the peach gum cannot be completely dissolved, and there are obvious sticky particles. The analysis reason is that the amount of hydrogen peroxide added is insufficient and the dissolution temperature is too low. The product is shown in Figure 7 shown.

[0074] Figure 4 The peach gum solution of Example 4 has a glue concentration of 30% and a glue viscosity of 509 mPa.s. Figure 8The commercially available peach gum solution 1 is a peach gum solution prepared from commercially available peach gum powder, with a solid content of 30%, a glue viscosity of 63.5 mpa.s, and a transparency of 10.8%.

[0075] Fig. 9 The gouache pigment prepared from the peach gum solution of Example 4 is shown, and the color is light gray-blue with a small amount of water separation. Fig.10 The gouache pigment prepared by using commercial peach gum solution 1 is shown in the figure. The color is light gray-blue and there is serious water separation. The two gouache pigments have the same formula except that the glue used is different.

[0076] Fig.11 The scraper pattern is a light gray-blue gouache prepared with the peach gum solution of Example 4, and the scraping thickness is 200 μm. Fig.12 The scraper picture of the light gray blue gouache prepared by the commercially available peach gum solution 1, the scraping sample thickness is 200μm. Example 4 The gouache pigment light gray blue scraper 200μm prepared by the peach gum concentrate has slight cracks, and the gouache pigment light gray blue scraper 200μm prepared by the commercially available peach gum solution 1 has serious cracks.

[0077] Fig.13 The gouache pigment prepared by the peach gum solution of Example 4 is orange in color; Fig.14 The gouache pigment prepared by commercial peach gum solution 1 is orange in color; except for the different peach gum used, the other formulas of the two gouache pigments are exactly the same; Fig.13 and Fig.14 It can be seen that the gouache pigment orange prepared from the peach gum solution concentrate in Example 4 has no water separation, while the gouache pigment orange prepared from the peach gum solution 1 has serious water separation.

[0078] Fig.15 The scraper picture is a orange gouache prepared with the peach gum solution of Example 4, and the scraping thickness is 200 μm; Fig.16 The scraper picture of the orange gouache prepared by selling peach gum solution 1, the scraping thickness is 200μm. Fig.15 and Fig.16 It can be seen that the gouache pigment orange-yellow scraper 200 μm prepared by the peach gum solution in Example 4 has slight cracks, and the gouache pigment orange-yellow scraper 200 μm prepared by the peach gum solution 1 has serious cracks.

[0079] Fig.17 The commercially available peach gum solution 2 is a peach gum solution prepared from peach gum powder sold by another manufacturer, with a glue concentration of 30% and a glue viscosity of 2505 mpa.s.

[0080] Fig.18 The gouache pigment prepared from the peach gum solution of Example 4 is spring green in color; Fig.19The gouache pigment prepared from commercially available peach gum solution 2 is spring green in color; except for the different glue used, the other formulas of the two gouache pigments are exactly the same. Fig.18 and Fig.19 It can be seen that the gouache pigment Chunriqing prepared with the peach gum solution in Example 1 has a large painting area with one stroke, the painting is more uniform, the hand feels silky, and the same amount of gouache can paint a large area; the gouache pigment Chunriqing prepared with the commercially available peach gum solution 2 has a small painting area, is relatively sticky to the pen, cannot be dragged, has a water-like feel, and the same amount of gouache can paint a small area.

Claims

1. A method for preparing a high-solid and low-viscosity peach gum solution for gouache pigment, characterized in that The steps include: ① Soak the solid peach gum in water; ② Add hydrogen peroxide solution until the pH is 6-7, then heat and stir until the solid peach gum is completely dissolved to obtain the first treated liquid; ③ adding sodium hydroxide solution to the first treatment liquid to obtain a second treatment liquid; ④ Adding hydrogen peroxide solution to the second treatment liquid and stirring for bleaching, and then removing impurities through precipitation to obtain a third treatment liquid; ⑤ Cool the third treatment solution to 30-60°C, then add catalase to it, stir evenly, and remove excess hydrogen peroxide. ⑥ Settle and take the upper solution to obtain a high-solid and low-viscosity peach gum solution for gouache pigment.

2. The preparation method according to claim 1, characterized in that In step ①, the weight ratio of solid peach gum to water meets 1:2-6.

3. The preparation method according to claim 1, characterized in that The soaking time in step ① is 24 to 36 hours.

4. The preparation method according to claim 1, characterized in that The soaking water temperature in step ① is room temperature, and the temperature is raised to 90-140° C. in step ②.

5. The preparation method according to claim 1, characterized in that The mass percentage concentration of the hydrogen peroxide solution is 30-40%, and the amount of hydrogen peroxide added is 0.5‰-3‰ of the weight of the prepared solution.

6. The preparation method according to claim 1, characterized in that In step ③, the mass percentage concentration of the sodium hydroxide solution is 3-10%, and the addition amount of the sodium hydroxide is 5-20% of the mass of the solid peach gum.

7. The preparation method according to claim 1, characterized in that After adding sodium hydroxide solution in step ③, the pH value is 11-12.

8. The preparation method according to claim 1, characterized in that In step ④, the bleaching temperature is controlled at 75-95° C., and the pH value is adjusted to 7-8 by adding hydrogen peroxide solution.

9. The preparation method according to claim 1, characterized in that The activity of the catalase in step ④ is 100,000 U to 300,000 U, and the hydrogen peroxide solution in step ④ is added in an amount of 0.5 to 6% by weight.

10. The preparation method according to claim 1, characterized in that The high-solid and low-viscosity peach gum solution for gouache pigment obtained in step ④ has a solid content of 20-55% and a viscosity of 500-700 mpas.

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