CN116716756A - Coated paper, coating, biological adhesive and preparation method thereof - Google Patents

Abstract

The application provides coated paper, paint, biological adhesive and a preparation method thereof; the preparation method of the biological adhesive comprises the following steps: preparing soybean protein slurry, wherein the soybean protein slurry comprises water and soybean protein powder, and the concentration is 5-10%; adding a certain amount of starch into water, and uniformly stirring to obtain starch slurry; adding the soybean protein slurry into the starch slurry to form mixed slurry, wherein the solid content of the mixed slurry is 35% -45%; adding amylase into the mixed slurry, and stirring and dispersing uniformly; the total weight of the starch and the soybean protein powder is 100 parts, the soybean protein powder is 5-10 parts, and the amylase is 0.005-0.06 part. The paper coating prepared by the biological adhesive provided by the embodiment of the application has the characteristics of high solid content, high water retention and excellent rheological property, and overcomes the defects of brittle film quality, low strength, poor water resistance, poor printing performance and the like of common starch adhesives.

Description

Coated paper, coating, biological adhesive and preparation method thereof

Technical field

The present application relates to the technical field of papermaking coatings, specifically to a coated paper, coatings, biological adhesives and preparation methods thereof.

Background technique

The bonding between the pigment particles in the paint and the paper base is mainly achieved through adhesives. Currently, the most widely used coating adhesives are styrene-butadiene latex and starch. However, the raw material of styrene-butadiene latex comes from petrochemical products. Since petrochemical products are non-renewable resources, the price of styrene-butadiene latex is relatively high. Using styrene-butadiene latex as the main component of adhesives will not only lead to the consumption of non-renewable resources, but also This leads to an increase in the preparation cost of coatings, thereby increasing the production costs of coated paper for papermaking companies, which is also detrimental to the trend of green development and the achievement of carbon neutrality.

Contents of the invention

The first aspect of the embodiments of the present application provides a method for preparing a bioadhesive. The preparation method includes:

Preparing a soy protein slurry, wherein the soy protein slurry includes water and soy protein powder, with a concentration of 5-10%;

Add a certain amount of starch to the water and stir evenly to obtain a starch slurry;

Add the soy protein slurry to the starch slurry to form a mixed slurry, the solid content of the mixed slurry is between 35% and 45%;

Add amylase to the mixed slurry and stir to disperse evenly; wherein, each raw material is calculated on a dry basis, the weight sum of starch and soybean protein powder is 100 parts, the soybean protein powder is 5-10 parts, and the amylase is 0.005 -0.06 copies.

Wherein, the preparation method also includes adding any one or a mixture of more of glycerol, polyethylene glycol, and sorbitol to the mixed slurry.

Wherein, the preparation method also includes adding glycerol, polyethylene glycol, and sorbitol to the mixed slurry, wherein the added amount of glycerol is 5-20 parts, and the added amount of polyethylene glycol is 5-10 parts. parts, the amount of sorbitol added is 1-3 parts.

Wherein, the preparation method also includes adding formamide to the mixed slurry, and the added amount of formamide is 0.5-1 part.

Wherein, the amylase includes alpha-amylase and beta-amylase, wherein the alpha-amylase addition amount is 0.005-0.05 parts, and the beta-amylase addition amount is 0-0.01 parts.

Wherein, the preparation method also includes heating the mixed slurry to 80-85 degrees and keeping it warm for 15-30 minutes, and then using a steam pressure cooker to raise the temperature to 120-140 degrees for cooking.

Among them, the physical property indicators of the bioadhesive are as follows: solid content is 35-45%, viscosity is 100-500cps, and pH is 7.5-8.5.

In a second aspect, embodiments of the present application provide a bioadhesive, which is prepared by using the preparation method described in any one of the above embodiments.

In a third aspect, embodiments of the present application provide a coating for coating coated paper. The coating includes the following parts by weight of raw materials: 100 parts of ground calcium carbonate, 2-10 parts of styrene-butadiene latex, 0-8 parts of starch, and alkali. 0.1-1 part of the liquid, 0.1-1 part of the dispersant, 0.01-0.05 part of the defoaming agent and 0-14 parts of the bioadhesive described in the above embodiment.

In a fourth aspect, embodiments of the present application provide coated paper, which is prepared using the coating described in the above embodiments.

The bioadhesive provided in the embodiments of this application uses renewable resources - starch and soybean protein powder as the main body, and is prepared by complex amylase treatment, plasticization and cross-linking composite technology. The adhesive can be used in both pre-coating and top coating. It can be used. The prepared paper coating has the characteristics of high solid content, high water retention and excellent rheology, which solves the shortcomings of ordinary starch adhesives such as brittle film, low strength, poor water resistance and poor printing performance.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic flow diagram of an embodiment of the preparation method of the bioadhesive of the present application;

Figure 2 is a schematic flow diagram of another embodiment of the preparation method of the bioadhesive of the present application;

Figure 3 is a schematic diagram of the coating structure of an embodiment of the coated paper of the present application.

Detailed ways

The present application will be described in further detail below with reference to the accompanying drawings and examples. It is particularly pointed out that the following examples are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only some, not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

The terms “first”, “second” and “third” in the embodiments of this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, features defined as "first", "second", and "third" may explicitly or implicitly include at least one of these features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically limited. All directional indications (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the relative positional relationship between components in a specific posture (as shown in the drawings). , sports conditions, etc., if the specific posture changes, the directional indication will also change accordingly. The terms "including" and "having" and any variations thereof in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes Other steps or components inherent to such processes, methods, products or devices.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

Please refer to Figure 1. Figure 1 is a schematic flow chart of an embodiment of a method for preparing a bioadhesive of the present application. The preparation method includes but is not limited to the following steps.

Step S100, prepare soybean protein slurry.

To prepare soy protein slurry, weigh a certain amount of soy protein powder and water, and adjust the pH value to between 9.0-10.0 (specific pH values can be 9, 9.1, 9.2, 9.3, 9.5, 9.6, 9.8, 10, etc. ), the slurry temperature is controlled between 50-60 degrees (specifically, it can be 50 degrees, 52 degrees, 55 degrees, 60 degrees, etc.), mixed and stirred for 2 hours, and prepared to a concentration of 5-10% (specifically, it can be 5%, 6%, 6.5%, 7%, 9%, 10%, etc.) soy protein slurry, soy protein powder preferably has a degree of polymerization between 500-1000, and a specific surface area in the range of 3000-6000cm ² /g.

Step S200: Add a certain amount of starch to the water and stir evenly to obtain a starch slurry.

In this step, specifically, a certain amount of starch can be weighed, added to a certain amount of water, and stirred and dispersed to obtain a starch slurry. Wherein, the starch is one or a mixture of tapioca starch, corn starch, potato starch and wheat starch.

Step S300: Add soybean protein slurry to starch slurry to form a mixed slurry. The solid content of the mixed slurry is between 35% and 45%.

The raw materials are all calculated in parts by weight, and the raw materials are all calculated in absolute dry weight. The weight sum of starch and soybean protein is 100 parts, of which soybean protein is 5-10 parts.

Step S400: Add amylase to the mixed slurry and stir to disperse evenly.

Amylase is 0.005-0.06 parts. Alternatively, the amylase may include α-amylase and β-amylase, stir and disperse evenly; the α-amylase addition amount is 0.005-0.05 parts, and the β-amylase addition amount is 0-0.01 parts.

Please refer to Figure 2. Figure 2 is a schematic flow chart of another embodiment of a method for preparing a bioadhesive of the present application. The preparation method includes but is not limited to the following steps.

Step S100, prepare soybean protein slurry.

To prepare soy protein slurry, weigh a certain amount of soy protein powder and water, and adjust the pH value to between 9.0-10.0 (specific pH values can be 9, 9.1, 9.2, 9.3, 9.5, 9.6, 9.8, 10, etc. ), the slurry temperature is controlled between 50-60 degrees (specifically, it can be 50 degrees, 52 degrees, 55 degrees, 60 degrees, etc.), mixed and stirred for 2 hours, and prepared to a concentration of 5-10% (specifically, it can be 5%, 6%, 6.5%, 7%, 9%, 10%, etc.) soy protein slurry, soy protein powder preferably has a degree of polymerization between 500-1000, and a specific surface area in the range of 3000-6000cm2/g.

Step S200: Add a certain amount of starch to the water and stir evenly to obtain a starch slurry.

In this step, specifically, a certain amount of starch can be weighed, added to a certain amount of water, and stirred and dispersed to obtain a starch slurry. Wherein, the starch is one or a mixture of tapioca starch, corn starch, potato starch and wheat starch.

Step S300: Add soybean protein slurry to starch slurry to form a mixed slurry. The solid content of the mixed slurry is between 35% and 45%.

The raw materials are all calculated in parts by weight, and the raw materials are all calculated in absolute dry weight. The weight sum of starch and soybean protein is 100 parts, of which soybean protein is 5-10 parts.

Step S400: Add amylase to the mixed slurry and stir to disperse evenly.

Amylase is 0.005-0.06 parts. Alternatively, the amylase may include α-amylase and β-amylase, stir and disperse evenly; the α-amylase addition amount is 0.005-0.05 parts, and the β-amylase addition amount is 0-0.01 parts.

Different from the previous embodiment, the preparation method in this embodiment also includes step S500, adding any one or a mixture of glycerol, polyethylene glycol, and sorbitol to the mixed slurry. Optionally, the added amount of glycerol is 5-20 parts, the added amount of polyethylene glycol is 5-10 parts, and the added amount of sorbitol is 1-3 parts. In addition, in some other embodiments, formamide may also be added to the mixed slurry, and the added amount of formamide is 0.5-1 part.

Please continue to refer to Figure 2. The preparation method also includes step S600, which is to heat the mixed slurry to 80-85 degrees and keep it warm for 15-30 minutes, and then use a steam pressure cooker to heat it to 120-140 degrees for cooking.

The above mixed slurry is heated to 80-85 degrees and kept warm for 15-30 minutes, and then heated to 120-140 degrees through a steam pressure cooker for cooking and pumped to a storage tank to obtain a high-strength bioadhesive finished product. The physical property indicators of the bioadhesive are as follows: solid content is 35-45%, viscosity is 100-500cps, and pH is 7.5-8.5.

Several specific embodiments will be introduced below.

Example 1: Weigh a certain amount of cassava starch, add water and mix evenly, then add soybean protein slurry. The dry weight ratio of cassava starch to soybean protein is 95:5. After thorough mixing, the solid content of the slurry is 35%, in which soybean protein powder The degree of body polymerization is 1000, the total amount of starch and soybean protein is 100 parts, the amount of α-amylase added is 0.02 parts, the amount of β-amylase added is 0.01 parts, and 18 parts of glycerol are added to the above starch slurry. 5 parts of polyethylene glycol, 1 part of sorbitol, and 1 part of formamide. After stirring evenly, heat the mixed slurry to 82 degrees and keep it warm for 20 minutes. Then use a JETCOOKER (steam pressure cooker) to heat it to 135 degrees for cooking and pumping. Go to the storage tank to get the finished product with biological viscosity.

Example 2: Weigh a certain amount of corn starch, add water and mix evenly, then add soy protein slurry. The dry weight ratio of corn starch to soy protein is 90:10. After thorough mixing, the solid content of the slurry is 45%, in which soy protein The degree of polymerization of the powder is 500. The total amount of starch and soybean protein is 100 parts. The amount of α-amylase added is 0.05 parts. To the above starch slurry, add 15 parts of glycerol, 2 parts of polyethylene glycol, and sorbitol. Add 2 parts of alcohol and 0.5 parts of formamide. After stirring evenly, heat the mixed slurry to 85 degrees and keep it warm for 15 minutes. Then use JETCOOKER to heat it to 120 degrees for cooking and pump it to the storage tank to obtain the biological adhesive viscosity product 2.

Example 3: Weigh a certain amount of potato starch, add water and mix evenly, then add soybean protein slurry. The dry weight ratio of potato starch to soybean protein is 92:8. After thorough mixing, the solid content of the slurry is 40%, in which soybean protein The degree of polymerization of the powder is 800, the total amount of starch and soybean protein is 100 parts, the amount of α-amylase added is 0.05 parts, the amount of β-amylase added is 0.005 parts, and 20 parts of glycerol are added to the above starch slurry. , 8 parts of polyethylene glycol, 1 part of sorbitol, and 1 part of formamide. After stirring evenly, heat the mixed slurry to 80 degrees and keep it for 23 minutes. Then use JETCOOKER to heat it to 140 degrees for cooking, and pump it to the storage tank to obtain biomass. The finished product has three adhesive viscosity.

The technical solution in the embodiment of the present application uses composite bio-adhesive starch and soy protein as the main body. The addition of soy protein improves the bonding strength of the bio-adhesive, and then undergoes conversion with complex amylase and plasticization modification to obtain a high-strength bio-adhesive. Type adhesive, the treatment of compound amylase can evenly cut the starch molecular chain, reduce the viscosity and significantly improve its rheology. The plasticization treatment can change the starch molecular configuration and disorder the molecular structure, forming thermoplastic starch. The use of various plasticizers (glycerin, polyethylene glycol, sorbitol, formamide) makes the film of starch softer and improves the folding and printing performance of the paper after application.

In addition, the embodiments of the present application also provide an application example of a biological adhesive, which may be a coating for coated paper, or a pre-coating coating for coating. The pre-coating coating contains the biological adhesive in the embodiments of the present application; coating The pre-coated coating includes the following raw materials by weight: 100 parts of ground calcium carbonate C65, 2-6 parts of styrene-butadiene latex, 0-8 parts of starch, 0.2 parts of alkali solution, 0.2 parts of dispersant, 0.05 parts of defoaming agent and biological Type adhesive 0-14 parts, of which ground calcium carbonate C65 has a particle size less than 2 μm accounting for more than 65%;

According to the above weight ratio, add ground calcium carbonate C65, styrene-butadiene latex, bio-based adhesive/starch, dispersant and defoaming agent in order and stir. It is necessary to add alkali solution while stirring. After sufficient stirring, use thickener Adjust the viscosity to a solid content of 65-68%, a viscosity of 500-1000 cps, and adjust the pH to 9.0 to obtain a pre-coating coating for coating.

In addition, the embodiment of the present application also provides a coated paper. Please refer to Figure 3. Figure 3 is a schematic diagram of the coating structure of an embodiment of the coated paper of the present application. The mark 101 represents the base paper, and the mark 102 represents the pre-coating. 103 means topcoat. Among them, the pre-coating paint 102 can be made of the aforementioned pre-coating paint material, and the top-coating paint 103 can be made of the following formula.

The topcoat coating can include the following raw materials in parts by weight: 100 parts in total of ground calcium carbonate C98, 10 parts of styrene-butadiene latex, 0.2 parts of alkali solution, 0.2 parts of dispersant, 0.05 parts of defoaming agent, and 0.4 parts of water-resistant agent, of which ground carbonic acid Calcium C98 has a particle size less than 2 μm accounting for more than 98%. According to the above weight ratio, add ground calcium carbonate C98, styrene-butadiene latex, bio-based adhesive, dispersant, defoaming agent and hydration-resistant agent in order and stir. It is necessary to add alkali solution while stirring. After stirring thoroughly, use the addition agent. The thickener is adjusted to a solid content of 67 to 71%, a viscosity of 1600 to 3000 cps, and the pH is adjusted to 9.0 to obtain a top coating for coating.

The specific experimental parameter characteristics are as follows.

The pure starch adhesive in the control group 2 has shortcomings such as brittle film, low strength, poor water resistance, and poor printing performance. The bioadhesive in the embodiment of the present application is significantly better than the starch adhesive in terms of strength. Compared with the butadiene-styrene in the control group 1 The latex is close, and other qualities meet the requirements.

The bioadhesive provided in the embodiments of this application uses renewable resources - starch and soybean protein powder as the main body, and is prepared by complex amylase treatment, plasticization and cross-linking composite technology. The adhesive can be used in both pre-coating and top coating. It can be used. The prepared paper coating has the characteristics of high solid content, high water retention and excellent rheology, which solves the shortcomings of ordinary starch adhesives such as brittle film, low strength, poor water resistance and poor printing performance.

The above are only some of the embodiments of the present application, and are not intended to limit the scope of protection of the present application. Any equivalent device or equivalent process transformation made using the contents of the description and drawings of the present application, or directly or indirectly used in other related The technical fields are all equally included in the scope of patent protection of this application.

Claims (10)

1. A method for preparing a biological adhesive, which is characterized by comprising the following steps:

preparing soybean protein slurry, wherein the soybean protein slurry comprises water and soybean protein powder, and the concentration is 5-10%;

adding a certain amount of starch into water, and uniformly stirring to obtain starch slurry;

adding the soybean protein slurry into the starch slurry to form mixed slurry, wherein the solid content of the mixed slurry is 35% -45%;

adding amylase into the mixed slurry, and stirring and dispersing uniformly; wherein, the weight sum of the starch and the soybean protein powder is 100 parts, the soybean protein powder is 5-10 parts, and the amylase is 0.005-0.06 parts by absolute dry weight.

2. The method according to claim 1, further comprising adding any one or more of glycerol, polyethylene glycol, and sorbitol to the mixed slurry.

3. The method according to claim 1, further comprising adding glycerol, polyethylene glycol, and sorbitol to the mixed slurry, wherein the amount of glycerol added is 5 to 20 parts, the amount of polyethylene glycol added is 5 to 10 parts, and the amount of sorbitol added is 1 to 3 parts.

4. The production method according to claim 2, further comprising adding formamide to the mixed slurry in an amount of 0.5 to 1 part.

5. The method according to claim 1, wherein the amylase comprises an alpha-amylase and a beta-amylase, and wherein the alpha-amylase is added in an amount of 0.005 to 0.05 parts and the beta-amylase is added in an amount of 0 to 0.01 parts.

6. The method according to claim 1, further comprising heating the mixed slurry to 80-85 ℃ and maintaining the temperature for 15-30 minutes, and then heating to 120-140 ℃ by using a steam pressure cooker for cooking.

7. The method of claim 1, wherein the physical properties of the bioadhesive are as follows: the solid content is 35-45%, the viscosity is 100-500cps, and the pH is 7.5-8.5.

8. A bioadhesive prepared by the method of any one of claims 1-7.

9. The coating for coating the coated paper is characterized by comprising the following raw materials in parts by weight: 100 parts of ground calcium carbonate, 2-10 parts of styrene-butadiene latex, 0-8 parts of starch, 0.1-1 part of alkali liquor, 0.1-1 part of dispersing agent, 0.01-0.05 part of defoaming agent and 0-14 parts of biological adhesive in claim 8.

10. Coated paper, characterized in that it is obtained by using the coating according to claim 9.