Use of a modified oxidized polyethylene wax dispersion in starch aging prevention

Abstract

The application provides application of a modified oxidized polyethylene wax dispersion liquid in starch aging prevention, is used for cooking of raw starch, can significantly reduce the 325 mesh residue of starch paste, improves the cleanliness of the paper machine sizing system, reduces the generation of coating marks and other paper diseases; meanwhile, the viscosity stability of the starch paste is obviously improved, and the aging performance is improved. The starch paste can be used in the papermaking industry, and the tapioca starch can be replaced in a large proportion, and the application direction is widened.

Description

Technical Field

[0001] This invention relates to the application of a modified oxidized polyethylene wax dispersion in starch anti-aging. Background Technology

[0002] Corn starch is produced in large quantities and is inexpensive, making it widely used in various industries. In 2019, among the downstream consumption structures of corn starch, the paper industry accounted for 16% of demand, and textile sizing accounted for 2%, making them the industries with the largest demand after starch sugar.

[0003] Starch is indeed one of the most important raw materials in papermaking, with raw materials mainly coming from corn starch, tapioca starch, and various modified starches. Tapioca starch has excellent properties, but due to its high price, companies are looking for corn starch as a substitute. However, due to the inherent characteristics of corn starch, such as high residue after cooking and severe aging, it cannot completely replace tapioca starch in the papermaking industry.

[0004] At the same time, a number of new demand areas are in their early stages of development, such as biodegradable biological products and new materials, including biodegradable waterproof and oil-resistant food packaging paper, which will increase the demand for corn starch.

[0005] This invention relates to the application of a modified oxidized polyethylene wax dispersion in starch dispersion and anti-aging. When used for cooking native starch, it significantly reduces the residue on a 325-mesh sieve of the starch paste, improves the cleanliness of the sizing system, and reduces paper defects such as coating marks. Simultaneously, it significantly improves the viscosity stability of the starch paste and enhances its aging performance. This allows it to be used in the papermaking industry, potentially replacing cassava starch in large proportions, thus broadening its application scope. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide an application of modified oxidized polyethylene wax dispersion in starch anti-aging. When applied to the cooking of native starch, the modified oxidized polyethylene wax dispersion can significantly reduce the residue on a 325-mesh sieve of the starch paste, while also significantly improving the aging properties of the starch, enabling it to replace cassava starch in a large proportion in the papermaking industry.

[0007] To address the aforementioned problems, this invention provides an application of modified oxidized polyethylene wax dispersion in starch anti-aging. The invention is characterized by the following steps: In a starch cooking process, water, starch, and amylase are added to a reactor at room temperature, and stirring is initiated to form a starch slurry with a concentration of 15-35%. Then, 0.5-10% of the modified oxidized polyethylene wax dispersion relative to the starch dosage is added. The mixture is then heated to above 80°C and cooked for 15-60 minutes. After steam inactivation, the mixture is filtered, cooled, and discharged to obtain a starch paste.

[0008] Preferably, the modified oxidized polyethylene wax dispersion is prepared by compounding 80-100 parts of oxidized polyethylene wax, 5-100 parts of polypropylene glycol, 5-80 parts of urea, and 200-3000 parts of water by weight.

[0009] Preferably, the oxidized polyethylene wax dispersion is an aqueous dispersion product or a mixture of grafted functional monomers prepared by grafting one or more functional monomers onto oxidized polyethylene wax, wherein the functional monomers are 5-25 parts by mass.

[0010] Preferably, the functional monomer is selected from one or more of (meth)acrylate, polyethylene glycol itacate, and polypropylene glycol acrylate.

[0011] Preferably, the starch is selected from one or a mixture of two of corn starch and tapioca starch.

[0012] As a preferred option, the modified oxidized polyethylene wax dispersion is used in starch anti-aging, and its dosage is 0.5-10% of the starch dosage.

[0013] The chemicals provided by this invention are used in starch dispersion and anti-aging, and their dosage is 0.5-10% of the starch dosage.

[0014] The starch processed by the solution provided by this invention can be used in, but is not limited to, the papermaking industry and the textile sizing industry.

[0015] Due to the adoption of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0016] The modified oxidized polyethylene wax dispersion provided by this invention uses oxidized polyethylene wax modified with functional monomers such as (meth)acrylate polyethylene glycol ester, polyethylene glycol itaconic acid ester, and polypropylene glycol acrylate, and is compounded with polypropylene glycol and urea. This invention is used in the cooking of raw starch, promoting the dispersion and dissolution of starch granules, bran, proteins, and other substances during starch gelatinization and cooking, thereby reducing the residue caused by the precipitation of these substances in the system, improving the cleanliness of the sizing system, and thus reducing paper defects such as coating marks. Simultaneously, the addition of modified oxidized polyethylene wax can form a film between starch micelles, greatly reducing the decrease in starch solubility caused by hydrogen bonding between starch micelles during cooling, improving aging phenomena, and increasing the viscosity stability of the starch paste. This allows it to be used in the papermaking industry, where it can replace cassava starch in a large proportion, broadening its application scope. Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are generally the conditions in conventional experiments. In addition, unless otherwise specified, "parts" and "%" below refer to parts by mass and mass percentage, respectively. Example 1

[0018] A modified oxidized polyethylene wax dispersion was prepared by compounding 100 parts effective parts of an aqueous dispersion prepared by graft polymerization of oxidized polyethylene wax and polyethylene glycol itaconic acid under the action of an initiator, 50 parts of polypropylene glycol, 50 parts of urea, and 1000 or 3000 parts of water; wherein the oxidized polyethylene wax comprises 100 parts, polyethylene glycol itaconic acid comprises 20 parts, and an initiator comprises 1 part. Example 2

[0019] A modified oxidized polyethylene wax dispersion was prepared by compounding 100 parts effective parts of an aqueous dispersion prepared by graft polymerization of oxidized polyethylene wax and polyethylene glycol acrylate under the action of an initiator, 40 parts of polypropylene glycol, 60 parts of urea, and 200, 500, or 2000 parts of water, wherein 80 or 100 parts of oxidized polyethylene wax, 5, 20, or 25 parts of polyethylene glycol acrylate, and 1 part of initiator. Example 3

[0020] A modified oxidized polyethylene wax dispersion was prepared by graft polymerization of an aqueous dispersion containing 100 parts effective parts of oxidized polyethylene wax and polypropylene glycol acrylate or a mixture of polypropylene glycol acrylate and polyethylene glycol itaconic acid under the action of an initiator, along with 60 parts of polypropylene glycol, 100 parts of urea, and 1500 parts of water. The modified oxidized polyethylene wax dispersion consisted of 95 parts oxidized polyethylene wax, 20 parts polypropylene glycol acrylate, or 1 part initiator; the mixture of polypropylene glycol acrylate and polyethylene glycol itaconic acid consisted of 5 parts polypropylene glycol acrylate and 20 parts polyethylene glycol itaconic acid.

[0021] Application of modified oxidized polyethylene wax dispersion on a paper machine: Water and corn starch were added to a mixing tank for dispersion to prepare a 15% or 25% starch slurry. 200 ppm of amylase (relative to oven-dry starch) was added, followed by 2% of the modified oxidized polyethylene wax dispersion prepared in Examples 1-3. The mixture was heated to 80°C or 90°C by steam and held for 15 minutes, then heated to above 95°C by steam and held for another 15 minutes before being discharged. This yielded a starch paste. The control group did not contain the modified oxidized polyethylene wax dispersion. The residue on a 325-mesh sieve and viscosity changes were tested, and the sizing and cleaning time was recorded.

[0022] Application of modified oxidized polyethylene wax dispersion on paper machines (Part 2). Water and corn starch were added to a mixing tank for dispersion to prepare a 30% or 35% starch slurry. 300 ppm of amylase (relative to oven-dry starch) was added, followed by 3% modified oxidized polyethylene wax dispersion (Examples 1-3). Steam was introduced to raise the temperature to above 90°C and held for 30 minutes for high-temperature steam inactivation. The product was then discharged. A starch paste was obtained. The control group did not contain the modified oxidized polyethylene wax dispersion.

[0023] Test the residue on a 325-mesh sieve and the viscosity change, and record the cleaning time for sizing.

[0024] Example 4 Test Results

[0025] control group Example 1 Example 2 Example 3 325 mesh sieve residue % 0.6 0.35 0.3 0.3 Starch paste viscosity (cps, 80℃) 18 15 16 15 Starch paste viscosity (cps, 60℃) 25 20 21 20 Starch paste viscosity (cps) (40℃) 43 29 30 29 Viscosity change at 60℃ (8h) 40 27 28 26 Glue application and cleaning cycle 1-2 days 3-4 days 3-4 days 3-4 days

[0026] Example 5 Test Results

[0027] control group Example 1 Example 2 Example 3 325 mesh sieve residue % 0.75 0.4 0.35 0.4 Starch paste viscosity (cps, 80℃) 28 27 26 27 Starch paste viscosity (cps, 60℃) 45 34 32 33 Starch paste viscosity (cps) (40℃) 65 44 43 43 Viscosity change at 60℃ (8h) 63 41 40 41 Glue application and cleaning cycle 1-2 days 3-4 days 3-4 days 3-4 days

[0028] The results showed that the modified oxidized polyethylene wax dispersion could enhance the anti-aging properties of starch paste and improve its dispersibility, significantly reducing the residue of raw starch on the sieve and improving the cleanliness of the paper machine sizing system, resulting in significant economic benefits. At the same time, the viscosity stability of the starch paste was improved.

[0029] In summary, the application of the modified oxidized polyethylene wax dispersion described in this invention in starch dispersion and anti-aging, when used for cooking native starch, significantly improves the viscosity stability of starch paste, enhances its aging performance, and can significantly reduce the residue on a 325-mesh sieve of starch paste, improve the cleanliness of the paper machine sizing system, and reduce paper defects such as coating marks. Its application in the papermaking industry allows it to largely replace cassava starch, broadening its application scope.

[0030] The present invention has been described in detail above, with the aim of enabling those skilled in the art to understand and implement the invention. However, this description should not be construed as limiting the scope of protection of the invention. All equivalent changes or modifications made in accordance with the spirit and essence of the invention should be included within the scope of protection of the invention.

Claims

1. Use of a modified oxidized polyethylene wax dispersion in the anti-aging of starch, characterized in that, In the starch cooking process, water, starch, amylase are added into the reactor under normal temperature conditions, stirring is started, starch milk with mass fraction of 15-35% is formed, 0.5-10% modified oxidized polyethylene wax dispersion liquid relative to the amount of starch is added according to the mass percentage, steam is heated to 80-100℃ for cooking for 15-60min, then after steam inactivation, filtration, cooling and discharging, starch paste is obtained; the modified oxidized polyethylene wax dispersion liquid is prepared by graft polymerization of oxidized polyethylene wax and polyethylene glycol itaconate under the action of an initiator, and is compounded with 100 parts of the aqueous dispersion, 50 parts of polypropylene glycol, 50 parts of urea and 1000 parts or 3000 parts of water according to mass fraction; the oxidized polyethylene wax is 100 parts, the polyethylene glycol itaconate is 20 parts, and the initiator is 1 part.

2. Use of a modified oxidized polyethylene wax dispersion in the anti-aging of starch, characterized in that, In the starch cooking process, water, starch, amylase are added into the reactor under normal temperature conditions, stirring is started, starch milk with mass fraction of 15-35% is formed, 0.5-10% modified oxidized polyethylene wax dispersion liquid relative to the amount of starch is added according to the mass percentage, steam is heated to 80-100℃ for cooking for 15-60min, then after steam inactivation, filtration, cooling and discharging, starch paste is obtained; the modified oxidized polyethylene wax dispersion liquid is prepared by graft polymerization of oxidized polyethylene wax and polyethylene glycol itaconate under the action of an initiator, and is compounded with 100 parts of the aqueous dispersion, 50 parts of polypropylene glycol, 50 parts of urea and 1000 parts or 3000 parts of water according to mass fraction; the oxidized polyethylene wax is 100 parts, the polyethylene glycol itaconate is 20 parts, and the initiator is 1 part.

3. Use of a modified oxidized polyethylene wax dispersion in the anti-aging of starch, characterized in that, In the starch cooking process, water, starch, amylase are added into the reactor under normal temperature conditions, stirring is started, starch milk with mass fraction of 15-35% is formed, 0.5-10% modified oxidized polyethylene wax dispersion liquid relative to the amount of starch is added according to the mass percentage, steam is heated to 80-100℃ for cooking for 15-60min, then after steam inactivation, filtration, cooling and discharging, starch paste is obtained; the modified oxidized polyethylene wax dispersion liquid is prepared by graft polymerization of oxidized polyethylene wax and polyethylene glycol itaconate under the action of an initiator, and is compounded with 100 parts of the aqueous dispersion, 50 parts of polypropylene glycol, 50 parts of urea and 1000 parts or 3000 parts of water according to mass fraction; the oxidized polyethylene wax is 100 parts, the polyethylene glycol itaconate is 20 parts, and the initiator is 1 part.

4. Use of the modified oxidized polyethylene wax dispersion according to any one of claims 1 to 3 in the anti-aging of starch, characterized in that: The starch is selected from one or a mixture of two of corn meal and cassava starch. The starch is selected from one or a mixture of two of corn meal and cassava starch.