Film-forming agent as well as preparation method and application thereof

Abstract

The invention relates to the field of starch type textile impregnating compounds, and discloses a film-forming agent as well as a preparation method and application thereof. The method comprises the following steps: performing acidolysis and gelatinization on starch slurry to obtain starch paste, mixing the starch paste with pullulanase and isoamylase, and performing enzymolysis. By adopting the method provided by the invention, the film-forming agent suitable for application can be prepared by utilizing the common starch which is easy to obtain, and the produced product is relatively stable in performance, is more friendly to downstream application and has a higher practical production value.

Description

Technical Field

[0001] The invention relates to the field of starch-type textile sizing agents, and in particular to a film-forming agent and a preparation method and application thereof. Background Art

[0002] Starch-based wetting agent is a general-purpose wetting agent for producing textile yarns for the electronics industry. It has the advantages of non-toxic raw materials, no irritation to the human body, and environmental friendliness. The glass fiber produced is fine, the yarn quality is good, the applicability is wide, and thermal cleaning is convenient. The woven electronic cloth has a low thermal decomposition temperature and is easy to heat treat. Starch-based wetting agents contain an important component-film-forming agent, which is generally prepared from starch. In order to give full play to the role of starch-based wetting agents, it is generally necessary for the film-forming agent to have a good protective effect on the glass fiber bundles. There are very few hairs during decomposition and weaving. The post-processed cloth surface is white, smooth, and has no black-brown stripes. The residual carbon content is low, which can reach n×10 -4 (n is 1 to 9) level. However, in the current production process, the prepared film-forming agent products often have unstable performance and large fluctuations, which leads to the need to readjust the formula in downstream applications, unstable product quality, and difficulty for workers to operate, which is not conducive to actual production. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and to provide a film-forming agent and a preparation method and application thereof. By adopting the method provided by the present invention, a film-forming agent suitable for application can be prepared using easily available common starch. The prepared product has relatively stable performance. When used as a film-forming agent, there are very few hairs and the strength is high. It can meet the requirements of high-speed wire drawing process and can meet the formula viscosity requirements when used downstream.

[0004] In order to achieve the above object, the present invention provides a method for preparing a film-forming agent, which comprises: subjecting starch slurry to acid hydrolysis and gelatinization to obtain starch paste, and mixing the starch paste with pullulanase and isoamylase for enzymolysis.

[0005] The second aspect of the present invention provides a film-forming agent prepared by the method described above.

[0006] The third aspect of the present invention provides use of the method described in the first aspect or the film-forming agent described in the second aspect in the preparation of a starch-type wetting agent.

[0007] By adopting the technical solution provided by the present invention, a film-forming agent suitable for application can be prepared by using common starch that is easily available, without any special requirements for the raw materials, and the performance of the produced product is relatively stable, that is, a film-forming agent with performance that meets the requirements can be obtained for starch from common sources. In addition, it is more friendly to downstream applications and has more practical production value. DETAILED DESCRIPTION

[0008] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0009] In a first aspect, the present invention provides a method for preparing a film-forming agent, the method comprising: subjecting starch slurry to acid hydrolysis and gelatinization to obtain starch paste liquid, and mixing the starch paste liquid with pullulanase and isoamylase for enzymolysis.

[0010] The inventors of the present invention have found in their research that by adopting the method as described above to prepare a film-forming agent, a film-forming agent suitable for application can be prepared using easily available common starch, and the obtained product has stable performance, is more friendly to downstream applications, and has more practical production value.

[0011] The sources of the pullulanase and isoamylase are not particularly limited and can be purchased from the market or obtained by separation and extraction. Pullulanase can specifically cut the α-1,6 glycosidic bonds in the branch points of chondramine, and isoamylase can also specifically cut the α-1,6 glycosidic bonds in the branch points of chondramine.

[0012] According to the present invention, preferably, in the starch slurry, the mass of amylopectin accounts for 50-80wt% of the total mass of starch (for example, it can be 50wt%, 55wt%, 60wt%, 62wt%, 65wt%, 66wt%, 67wt%, 67.3wt%, 67.8wt%, 68wt%, 68.5wt%, 68.7wt%, 69wt%, 70wt%, 72wt%, 75wt%, 78wt%, 80wt% and the range formed by any two of the above values ​​and the value within the range), more preferably 67.3-68.7wt%. It can be understood that the general commercially available starch can meet the above parameter range, and the method provided by the present invention has no special requirements for raw materials. The mass proportion of amylose can be determined by "GB / T 15683-2008 Determination of Rice Amylose Content", and the remaining part is the mass proportion of amylopectin.

[0013] The present invention has no particular limitation on the specific source of starch. However, preferably, in the starch slurry, the starch is corn starch and / or pea starch, more preferably corn starch and pea starch.

[0014] More preferably, the mass ratio of corn starch to pea starch is 1:(0.5-0.8). Corn starch and pea starch are relatively easy to obtain, have a wide range of sources, can be purchased commercially, or can be prepared by oneself. The inventors of the present invention further found in their research that when corn starch and pea starch are used, especially when corn starch and pea starch are used in the specific ratio as described above, it can further ensure that a film-forming agent with stable performance and fully meeting the requirements is obtained.

[0015] According to the present invention, preferably, in the starch slurry, the mass concentration of starch is 10-25wt% (for example, it can be 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, 22wt%, 25wt% and the range formed by any two of the above values ​​and the value within the range). Starch and water can be mixed to prepare a slurry with the above concentration.

[0016] It can be understood that the mass of starch mentioned above refers to the mass on a dry basis.

[0017] According to the present invention, preferably, the temperature of the acid hydrolysis is 30-50°C (for example, it can be 30°C, 32°C, 35°C, 38°C, 40°C, 42°C, 45°C, 48°C, 50°C and the range formed by any two of the above values ​​and the value within the range), and the time of the acid hydrolysis is 2-6h (for example, it can be 2h, 3h, 4h, 5h, 6h and the range formed by any two of the above values ​​and the value within the range). The acid hydrolysis can be carried out in a water bath.

[0018] According to the present invention, preferably, in the acid hydrolysis, the amount of acid used is 0.05-2g, more preferably 0.2-1g relative to 100g of starch (for example, it can be 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.7g, 0.8g, 0.9g, 1g, and the range formed by any two of the above values, and the value within the range).

[0019] According to the present invention, preferably, in the acidolysis, the acid is selected from at least one of hydrochloric acid and sulfuric acid. For example, concentrated hydrochloric acid or concentrated sulfuric acid can be added to the material.

[0020] According to the present invention, preferably, after acid hydrolysis and before gelatinization, the method further comprises: adjusting the pH of the material after acid hydrolysis to 5.5-6 (for example, it can be 5.5, 5.6, 5.7, 5.8, 5.9, 6 and the range formed by any two of the above values ​​and the value within the range). In this way, the subsequent gelatinization can be more sufficient. A base such as sodium hydroxide or potassium hydroxide can be added thereto, and the base can be used in the form of an aqueous solution, such as a solution with a base concentration of 8-16wt% (for example, it can be 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%).

[0021] According to the present invention, preferably, the gelatinization temperature is 70-90°C (for example, it can be 70°C, 72°C, 75°C, 78°C, 80°C, 82°C, 85°C, 88°C, 90°C and the range formed by any two of the above values ​​and the value within the range), and the time is 15-30min (for example, it can be 15min, 18min, 20min, 22min, 25min, 28min, 29min, 30min and the range formed by any two of the above values ​​and the value within the range). Within the above range, it can further ensure that the starch is fully gelatinized.

[0022] According to the present invention, preferably, relative to 100g of starch, the dosage of pullulanase is 6-50U, preferably 20-40U (for example, it can be 20U, 22U, 25U, 27U, 30U, 33U, 35U, 38U, 40U and the range formed by any two of the above values ​​and the value within the range).

[0023] According to the present invention, preferably, the dosage of isoamylase is 2-10U, preferably 3-6U (for example, it can be 3U, 4U, 5U, 6U and the range formed by any two of the above values ​​and the value within the range) relative to 100g of starch.

[0024] The inventors of the present invention have found in their research that when pullulanase or isoamylase is used in the above dosage, it can further ensure that a film-forming agent with stable performance and meeting the requirements is obtained.

[0025] According to the present invention, preferably, the enzyme activity ratio of pullulanase to isoamylase is 1:(0.075-0.3). The inventors of the present invention further found in their research that when the specific usage ratio of pullulanase to isoamylase is met, a film-forming agent with relatively stable performance and meeting the requirements can be obtained.

[0026] Wherein, U is the enzyme activity unit. In the present invention, the enzyme activity unit of pullulanase is defined as: the amount of enzyme required to liquefy 1 mg of soluble starch in 1 min at 60°C and pH 6. The enzyme activity unit of isoamylase is defined as: the amount of enzyme required to liquefy 1 mg of soluble starch in 1 min at 60°C and pH 6.

[0027] According to the present invention, preferably, the enzymatic hydrolysis time is 10-30 min (for example, it can be 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, 30 min and the range formed by any two of the above values ​​and the values ​​within the range), and the temperature is 40-60°C (for example, it can be 40°C, 42°C, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C and the range formed by any two of the above values ​​and the values ​​within the range).

[0028] According to the present invention, preferably, after enzymolysis, the method further comprises: sequentially performing solid-liquid separation, washing and drying on the enzymolyzed material. The solid-liquid separation method may be suction filtration. Distilled water may be used for washing, and the drying temperature may be 150-170° C. for 5-10 min. After drying, a powdery finished product may be obtained.

[0029] In a second aspect, the present invention provides a film-forming agent prepared by the method described above.

[0030] In a third aspect, the present invention provides use of the method described in the first aspect or the film-forming agent described in the second aspect in the preparation of a starch-type wetting agent.

[0031] The method for using the film-forming agent provided by the present invention can be the method for using the film-forming agent in the existing commonly used starch-type wetting agent. Generally, the film-forming agent is mixed with water and an organic auxiliary agent and prepared into an emulsion-shaped wetting agent. Generally, the organic auxiliary agent can include a coupling agent, an antistatic agent and a pH regulator, wherein the coupling agent can be an epoxy silane coupling agent, an amino silane coupling agent, etc., and the antistatic agent can be a tetraalkylammonium salt, etc.

[0032] The obtained sizing agent can also be applied in the conventional sizing agent application method, that is, the sizing agent is coated on the surface of the glass fiber for drawing.

[0033] The present invention will be described in detail below through examples.

[0034] In the following examples, pullulanase was obtained from Guangxi Academy of Sciences, and the specific activity of the enzyme was 2000 U / g;

[0035] Isoamylase, from Guangxi University, with an enzyme specific activity of 300 U / g;

[0036] Unless otherwise specified, in the examples, corn starch was produced in-house and pea starch was purchased from Yantai Oriental Protein Technology Co., Ltd.

[0037] The mass fraction of hydrogen chloride in concentrated hydrochloric acid is 37wt%;

[0038] The mass percentage of amylose was determined using "GB / T 15683-2008 Determination of Amylose Content in Rice", and the remainder was the mass percentage of amylopectin;

[0039] The washing after enzymolysis was carried out with distilled water, and the drying temperature after enzymolysis was 160°C for 7 minutes.

[0040] Example 1

[0041] Weigh 36 grams of dry corn starch and 24 grams of dry pea starch, the mass of amylopectin accounts for 67.8 wt % of the total mass of starch, mix the starch with water to prepare a starch slurry with a starch mass fraction of 20 wt %, and stir evenly.

[0042] The starch slurry was placed in a water bath at a constant temperature of 35°C, stirred, and 1.2g of concentrated hydrochloric acid was added for acid hydrolysis for 3h. Then, the pH value was adjusted to 5.8 with a NaOH solution having a mass concentration of 16wt% to obtain an acid-hydrolyzed starch slurry.

[0043] The temperature of the water bath was adjusted to 80°C and maintained at this temperature for 30 min for gelatinization.

[0044] The material was cooled to 60° C., and 24 U of pullulanase and 1.8 U of isoamylase were added thereto for reaction for 20 min, during which the temperature was kept at 60° C. After the reaction, the material was filtered, washed, and dried to obtain the film-forming agent.

[0045] Example 2

[0046] Weigh 20 grams of dry corn starch and 10 grams of dry pea starch, the mass of amylopectin accounts for 68.7 wt% of the total mass of starch, mix the starch with water to prepare a starch slurry with a starch mass fraction of 10 wt%, and stir evenly.

[0047] The starch slurry was placed in a water bath at a constant temperature of 30°C, stirred, and 0.3g of concentrated hydrochloric acid was added for acid hydrolysis for 2h. Then, the pH value was adjusted to 5.5 with a NaOH solution having a mass concentration of 8wt% to obtain an acid-hydrolyzed starch slurry.

[0048] The temperature of the water bath was adjusted to 78°C and maintained at this temperature for 29 minutes for gelatinization.

[0049] The material was cooled to 45° C., and 6 U of pullulanase and 1.8 U of isoamylase were added thereto for reaction for 20 min, during which the temperature was kept at 45° C. After the reaction, the material was filtered, washed, and dried to obtain the film-forming agent.

[0050] Example 3

[0051] Weigh 42 grams of dry corn starch and 33 grams of dry pea starch, the mass of amylopectin accounts for 67.3 wt% of the total mass of starch, mix the starch with water to prepare a starch slurry with a starch mass fraction of 25 wt%, and stir evenly.

[0052] The starch slurry was placed in a water bath at a constant temperature of 45°C, stirred, and 0.75g of concentrated hydrochloric acid was added for acid hydrolysis for 3.5h. Then, the pH value was adjusted to 6 with a NaOH solution having a mass concentration of 12wt% to obtain an acid-hydrolyzed starch slurry.

[0053] The temperature of the water bath was adjusted to 85°C and maintained at this temperature for 28 minutes for gelatinization.

[0054] The material was cooled to 55° C., and 30 U of pullulanase and 4.5 U of isoamylase were added thereto for reaction for 30 min, during which the temperature was kept at 55° C. After the reaction, the material was filtered, washed, and dried to obtain the film-forming agent.

[0055] Example 4

[0056] Carry out according to the method for embodiment 1, except that, adopt 48g dry basis corn starch and 12 grams dry basis pea starch.

[0057] Example 5

[0058] The method of Example 1 was followed, except that the amount of pullulanase used was 4 U and the amount of isoamylase used was 1.2 U.

[0059] Example 6

[0060] The method of Example 1 was followed, except that the acid hydrolysis time was 15 min.

[0061] Example 7

[0062] The method of Example 1 was followed, except that pea starch was replaced with wheat starch, and the mass of amylopectin in the starch slurry accounted for 69wt% of the total mass of starch.

[0063] Comparative Example 1

[0064] The method of Example 1 was followed, except that isoamylase was not used, and only pullulanase was used in an amount of 25.8 U. The results are shown in Table 1.

[0065] Comparative Example 2

[0066] The method of Example 1 was followed, except that pullulanase was not used, and only isoamylase was used in an amount of 25.8 U.

[0067] Test Case

[0068] For the film-forming agent products prepared in the above examples and comparative examples, the particle size of the film-forming agent was measured.

[0069] In addition, the viscosity of each film-forming agent was tested as follows: 500 ml of a sample solution of 10 wt% of the film-forming agent was prepared and placed in a 100°C water bath for gelatinization. The sample solution was stirred continuously during the heating process (rotor No. 1, speed 100 rpm), the temperature was raised to 95°C, the sample was taken out after being kept warm for 30 minutes, cooled to 60°C, and the viscosity was measured.

[0070] The results are shown in Table 1.

[0071] Table 1

[0072] Example No. Particle size (μm) Viscosity (10wt%, cp) Example 1 18 62 Example 2 19 56 Example 3 21 70 Example 4 23 39 Example 5 32 119 Example 6 25 123 Example 7 52 130 Comparative Example 1 65 40 Comparative Example 2 55 37

[0073] The film-forming agent prepared by the method provided by the present invention can meet the requirements of particle size (generally required to be 3-60 μm, especially 15-20 μm) and solution viscosity during downstream production and application (generally required to be 30-150 cp, especially 50-75 cp), indicating that by adopting the method of the present invention, a film-forming agent product with good performance can be obtained using common and easily available starch raw materials.

[0074] In addition, when the film-forming agent provided by the present invention is applied to the glass fiber drawing process, it is also found that the film-forming agent provided by Examples 1-3 is more uniform and dense in film formation, without cracking, and the film-forming agent provided by Examples 1-3 has better effect than the film-forming agent provided by Examples 4-7. Moreover, the film-forming agent prepared by the examples, especially the film-forming agent of Examples 1-3, when used for glass fiber drawing, has smoother film coating between the lines, and the inside of the glass fiber is tighter and more resilient; there are fewer hairs and broken hairs, which can be ignored; the original silk has higher stiffness; the breaking strength is higher, especially when the film-forming agent of Examples 1-3 is used, the breaking strength of the glass fiber is above 3000cN. The products of the comparative examples have poor film-forming effect when applied, with obvious broken hairs and hairs; and the original silk has average stiffness and low breaking strength.

[0075] It can be seen that by adopting the method provided by the present invention, a film-forming agent suitable for application can be prepared using readily available common starch, and the prepared product has good strength and viscosity during application, and the performance of the produced product is relatively stable, which is more friendly to downstream applications and has more practical production value.

[0076] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a film-forming agent, characterized in that: The method comprises: subjecting starch slurry to acid hydrolysis and gelatinization to obtain starch paste liquid, and mixing the starch paste liquid with pullulanase and isoamylase for enzymolysis.

2. The method according to claim 1, wherein: In the starch slurry, the mass of amylopectin accounts for 50-80wt% of the total mass of starch; and / or, in the starch slurry, the starch is corn starch and / or pea starch, more preferably corn starch and pea starch; Preferably, the mass ratio of corn starch to pea starch is 1:(0.5-0.8).

3. The method according to claim 1 or 2, wherein: In the starch slurry, the mass concentration of starch is 10-25wt%.

4. The method according to claim 1, wherein: The acid hydrolysis temperature is 30-50°C, and the acid hydrolysis time is 2-6h.

5. The method according to claim 1 or 4, wherein: In the acid hydrolysis, the amount of acid used is 0.05-2 g, more preferably 0.2-1 g, relative to 100 g of starch; And / or, in the acidolysis, the acid is selected from at least one of hydrochloric acid and sulfuric acid.

6. The method according to claim 1 or 4, wherein: After acid hydrolysis and before gelatinization, the method further comprises: adjusting the pH of the acid hydrolyzed material to 5.5-6; And / or, the gelatinization temperature is 70-90°C and the time is 15-30 min.

7. The method according to claim 1, wherein: Relative to 100g of starch, the dosage of pullulanase is 6-50U, preferably 20-40U; And / or, relative to 100g of starch, the dosage of isoamylase is 2-10U, preferably 3-6U.

8. The method according to claim 1 or 7, wherein: The enzyme activity ratio of pullulanase and isoamylase is 1:(0.075-0.3); and / or, the enzymatic hydrolysis time is 10-30 min and the temperature is 40-60° C.; And / or, after enzymatic hydrolysis, the method further comprises: sequentially performing solid-liquid separation, washing and drying on the enzymatically hydrolyzed material.

9. A film-forming agent prepared by the method according to any one of claims 1 to 8.

10. Use of the method according to any one of claims 1 to 8 or the film-forming agent according to claim 9 in the preparation of a starch-based wetting agent.