阅读说明：本技术 一种淀粉基生物胶乳及其制备方法和应用 (Starch-based biological latex and preparation method and application thereof ) 是由 杨冬梅 张东生 刘智维 王昱玉 于 2020-05-27 设计创作，主要内容包括：本发明提供一种淀粉基生物胶乳及其制备方法和应用,淀粉基生物胶乳的固含量为45～55％,包含以下按质量百分比份数计的原料：淀粉绝干质量百分比份数为100％；淀粉交联剂相对绝干淀粉质量百分比的比例为5～15％；淀粉塑性转化剂相对绝干淀粉质量百分比的比例为7～20％；常温水,根据淀粉基生物胶乳的固含量添加水量；其中,淀粉中水分的含量≤15％,淀粉交联剂和淀粉塑性转化剂的固含量均为50±2％,选用合适类型的淀粉交联剂及类型匹配的淀粉塑性转化剂,改善淀粉的塑性以控制淀粉的链长及改性,从而提高其成膜后的弯曲弹性和强度、以及耐水性；在制备釜中加水升温熬制过程中,控制合适的反应温度和时间,从而使反应变得简单、高效。(The invention provides a starch-based biological latex and a preparation method and application thereof, wherein the starch-based biological latex has a solid content of 45-55% and comprises the following raw materials in parts by mass: the absolute dry mass percentage of the starch is 100 percent; the mass percentage of the starch cross-linking agent to the absolutely dry starch is 5-15%; the mass percentage of the starch plasticity transforming agent to the absolutely dry starch is 7-20%; adding water at normal temperature according to the solid content of the starch-based biological latex; wherein, the content of water in the starch is less than or equal to 15 percent, the solid contents of the starch cross-linking agent and the starch plastic transforming agent are both 50 +/-2 percent, and the proper type of the starch cross-linking agent and the starch plastic transforming agent with matched types are selected to improve the plasticity of the starch so as to control the chain length and the modification of the starch, thereby improving the bending elasticity and the strength and the water resistance of the starch after film forming; in the process of adding water, heating and boiling in the preparation kettle, proper reaction temperature and time are controlled, so that the reaction becomes simple and efficient.)

1. The starch-based biological latex is characterized in that the target solid content of the starch-based biological latex is 45-55%, and the starch-based biological latex comprises the following raw materials in parts by mass:

starch, the absolute dry mass percentage is 100%;

the starch cross-linking agent accounts for 5-15% of the mass percentage of the absolutely dry starch;

the starch plasticity transforming agent accounts for 7-20% of the weight percentage of the absolutely dry starch;

adding water with the normal temperature water in an amount which is 45-55% of the target solid content designed according to the starch-based biological latex;

wherein, the content of water in the starch raw material is less than or equal to 15 percent, and the solid contents of the starch cross-linking agent and the starch plastic transforming agent are both 50 +/-2 percent.

2. The starch-based biological latex according to claim 1, wherein the starch is one or more of tapioca native starch, corn native starch, modified tapioca starch and modified corn starch.

3. The starch-based biological latex according to claim 1, wherein said starch crosslinking agent is a polyamide polyurea resin starch crosslinking agent.

4. The starch-based biological latex according to claim 1, wherein said starch plasticity transforming agent is N, N-dihydroxyethylformamide starch plasticity transforming agent.

5. The starch-based biological latex according to claim 1, wherein the starch-based biological latex is a light yellow transparent liquid, has a solid content of 45-55%, a viscosity of 150-500 mpa.s at 25 ℃, and a pH value of 6-7.

6. The method for preparing a starch-based biological latex according to any one of claims 1 to 5, comprising the steps of:

(1) equipment preparation

A reaction kettle, a metering pump and a storage tank with functions of stirring and heating by introducing steam;

(2) and preparation treatment

Before preparing the biological latex, firstly setting the preparation pot volume required by a reaction kettle to be 50-100%, and then calculating the total amount of all materials required by preparation according to the target solid content of the biological latex of 45-55%: the starch absolute dry mass fraction is 100%, the polyamide polyurea resin starch crosslinking agent is 5-15% relative to the absolute dry starch mass percentage, and the N, N-dihydroxyethylformamide starch plastic conversion agent is 7-20% relative to the absolute dry starch mass percentage; the insufficient pot capacity of the reaction kettle is the supplementary normal temperature water quantity; wherein the starch is one or more than two of cassava native starch, corn native starch, modified cassava starch and modified corn starch, the content of water in the starch raw material is less than or equal to 15 percent, and the solid contents of the starch cross-linking agent and the starch plastic conversion agent are both 50 +/-2 percent;

during preparation, adding the required supplementary normal-temperature water into a preparation kettle, starting a stirrer, stirring at a low speed of 100-500 rpm, and adding 100% of starch raw materials in absolute dry parts by mass; continuously stirring after the starch raw material is added, starting steam heating of the reaction kettle, heating to 90-95 ℃, turning off the steam, and stirring for 20-25 min; then, adding 5-15% of polyamide polyurea resin starch cross-linking agent in an oven-dry mass fraction relative to the oven-dry starch in percentage by mass, continuously stirring for 10-15 min, adding 7-20% of N, N-dihydroxyethyl formamide starch plastic converting agent in an oven-dry mass fraction relative to the oven-dry starch in percentage by mass, and stirring for 10-15 min to obtain the biological latex which is a light yellow transparent liquid, has a solid content of 45-55%, has a viscosity of 150-500 mpa.s at a temperature of 25 ℃ and has a pH value of 6-7.

7. The preparation method of the starch-based biological latex as claimed in claim 6, wherein in the step (2), the starch raw material is continuously stirred after being added, steam heating of the reaction kettle is started, the steam can be stopped when the temperature is raised to 90-95 ℃, and the stirring is carried out for more than 20 min.

8. The preparation method of the starch-based biological latex as claimed in claim 6, wherein in the step (2), 5-15% of the polyamide polyurea resin starch crosslinking agent is added in a ratio of oven dry weight to oven dry weight of starch, and the mixture is continuously stirred for more than 10 min.

9. The preparation method of the starch-based biological latex as claimed in claim 6, wherein in the step (2), the starch plasticity conversion agent of N, N-dihydroxyethylformamide is added in an amount of 7-20% by mass relative to the absolute dry starch, and the mixture is stirred for more than 10 min.

10. Use of a starch-based bio-latex according to any of claims 1 to 5, wherein said starch-based bio-latex is used in papermaking.

[ technical field ] A method for producing a semiconductor device

The invention relates to a coating technology in papermaking, in particular to a starch-based biological latex and a preparation method and application thereof.

[ background of the invention ]

In recent years, the price of products using petroleum products as raw materials is increasing, and in addition, petroleum products can cause environmental pollution, so in many petroleum product industries, especially in the paper making industry, more and more enterprises are dedicated to search for low-price, regenerated and pollution-free environment-friendly adhesive raw materials to replace traditional petroleum cracking products, such as petroleum-based latex synthesized by using butadiene and styrene as main monomers, for example, carboxylated styrene-butadiene latex. Moreover, starch is an organic compound with abundant natural content, has the remarkable characteristics of wide source, low price, degradability, renewability and the like, can be used as biological latex after being subjected to related modification treatment, and can partially or completely replace petroleum-based latex. The coating of the paper mill coated paper mainly comprises pigment, adhesive and auxiliary agent, the cost is mainly influenced by latex, calcium and starch, and in order to reduce the production cost and meet the requirement of environmental protection, the paper mill uses partial biological latex to replace carboxylic styrene-butadiene latex as the adhesive for coating the pigment.

In the existing paper coating process, the biological latex is mainly prepared by adding a starch modifier into a starch raw material, heating to a high temperature, preserving heat for a period of time, for example, heating to a high temperature of 80-95 ℃, preserving heat for 30-60 min, adding a catalyst, oxidizing for 30-120 min, adjusting the pH value, adding a crosslinking agent, reacting for 20-90 min at 50-70 ℃, and finally performing cooling screening and other technological measures; or adding some buffer solution into the starch solution, mixing, heating to 50-60 ℃, stirring, preserving heat for 40-60min, adding amylase, adjusting the pH value, reacting for 30-60 min, performing a series of drying, adding some organic solvent, dissolving, preserving heat for 60-180 min and the like to obtain the biological latex. In the above process, the selected auxiliary agent or amylase has higher requirements on reaction conditions, and the required processing effect can be achieved only by controlling the pH value within a certain range and carrying out longer reaction time and higher reaction temperature, so that the whole reaction process is long and the reaction temperature is high; moreover, the addition of various additives reaches three, four or more, which causes the operation process of the whole preparation process to be more complicated; meanwhile, the preparation process is selective to starch, is only suitable for single native starch or modified (denatured) starch, and once the process is shaped, the raw materials cannot be changed.

[ summary of the invention ]

Aiming at the problems that the reaction is complex due to excessive reaction auxiliary agents selected at present, the reaction temperature and the reaction time are further influenced, or the efficiency of selected reaction enzymes or auxiliary agents is not high, the invention provides the starch-based biological latex, which has the advantages that the starch raw materials are not limited, the reaction conditions and the reaction equipment are simple, one or two efficient reaction auxiliary agents are adopted to replace various auxiliary agents, the equipment flow is simplified, the chemical reaction in the preparation process is simple and efficient, the preparation process time is short, and the efficiency is high, and the preparation method and the application thereof.

In order to achieve the purpose, the technical scheme is as follows:

a starch-based biological latex has a target solid content of 45-55%, and comprises the following raw materials in parts by mass:

starch, the absolute dry mass percentage is 100%;

the starch cross-linking agent accounts for 5-15% of the mass percentage of the absolutely dry starch;

the starch plasticity transforming agent accounts for 7-20% of the weight percentage of the absolutely dry starch;

adding water with the normal temperature water in an amount which is 45-55% of the target solid content designed according to the starch-based biological latex;

wherein, the content of water in the starch raw material is less than or equal to 15 percent, and the solid contents of the starch cross-linking agent and the starch plastic transforming agent are both 50 +/-2 percent.

Further, the starch is one or more than two of cassava native starch, corn native starch, modified cassava starch and modified corn starch; the modified tapioca starch is obtained by chemically modifying tapioca, and the modified corn starch is obtained by chemically modifying corn native starch.

Further, the starch cross-linking agent is a polyamide polyurea resin starch cross-linking agent.

Further, the starch plasticity converting agent is an N, N-dihydroxyethylformamide starch plasticity converting agent.

Further, the starch-based biological latex is a light yellow transparent liquid, the solid content is 45-55%, the viscosity at the temperature of 25 ℃ is 150-500 mpa.s, and the pH value is 6-7.

A preparation method of starch-based biological latex comprises the following steps:

(1) equipment preparation

A reaction kettle, a metering pump and a storage tank with functions of stirring and heating by introducing steam;

(2) and preparation treatment

Before preparing the biological latex, firstly setting the preparation pot volume required by a reaction kettle to be 50-100%, and then calculating the total amount of all materials required by preparation according to the target solid content of the biological latex of 45-55%: the starch absolute dry mass fraction is 100%, the polyamide polyurea resin starch crosslinking agent is 5-15% relative to the absolute dry starch mass percentage, and the N, N-dihydroxyethylformamide starch plastic conversion agent is 7-20% relative to the absolute dry starch mass percentage; the insufficient pot capacity of the reaction kettle is the supplementary normal temperature water quantity; wherein the starch is one or more than two of cassava native starch, corn native starch, modified cassava starch and modified corn starch, the content of water in the starch raw material is less than or equal to 15 percent, and the solid contents of the starch cross-linking agent and the starch plastic conversion agent are both 50 +/-2 percent;

during preparation, adding the required supplementary normal-temperature water into a preparation kettle, starting a stirrer, stirring at a low speed of 100-500 rpm, and adding 100% of starch raw materials in absolute dry parts by mass; continuously stirring after the starch raw material is added, starting steam heating of the reaction kettle, heating to 90-95 ℃, turning off the steam, and stirring for 20-25 min; then, adding 5-15% of polyamide polyurea resin starch cross-linking agent in an oven-dry mass fraction relative to the oven-dry starch in percentage by mass, continuously stirring for 10-15 min, adding 7-20% of N, N-dihydroxyethyl formamide starch plastic converting agent in an oven-dry mass fraction relative to the oven-dry starch in percentage by mass, and stirring for 10-15 min to obtain the biological latex which is a light yellow transparent liquid, has a solid content of 45-55%, has a viscosity of 150-500 mpa.s at a temperature of 25 ℃ and has a pH value of 6-7.

Further, in the step (2), after the starch raw material is added, stirring is continued, steam heating of the reaction kettle is started, the temperature is increased to 90-95 ℃, the steam can be turned off, and stirring is carried out for more than 20 min.

Further, in the step (2), 5-15% of polyamide polyurea resin starch cross-linking agent in parts by weight of oven dry is added relative to the oven dry starch in percentage by weight, and the mixture is continuously stirred for more than 10 min.

Further, in the step (2), adding 7-20% of N, N-dihydroxyethyl formamide starch plastic conversion agent in absolute dry mass percentage relative to absolute dry starch, and stirring for more than 10 min.

Use of a starch-based bio-latex for the manufacture of paper.

The invention has the advantages that:

by analyzing the preparation process of the biological latex in various paper mills or chemical plants at present, the reasons for influencing the reaction temperature and the reaction time are that too much reaction auxiliary agent is selected to cause the reaction to be complicated, or the efficiency of the selected reaction enzyme or auxiliary agent is not high. The invention selects one or two high-efficiency reaction auxiliary agents to replace various auxiliary agents, and simplifies the equipment flow, thereby simplifying and improving the chemical reaction process in the preparation process.

In the specific implementation, different types of starch are used as raw materials, and a polyamide polyurea resin starch cross-linking agent is used for performing cross-linking reaction on starch branched chains, so that a bond bridge is formed between one starch molecule and another molecule to generate a cross-linked structure, and the film forming strength and the water resistance of the starch are improved; adding an N, N-dihydroxyethyl formamide starch plasticity conversion agent to improve the plasticity of the starch so as to control the chain length and modification of the starch, thereby improving the bending elasticity and strength of the starch after film forming; the reaction is simple and efficient by selecting a proper type of starch cross-linking agent and a type-matched starch plastic conversion agent.

In addition, in the process of adding water into a preparation kettle, raising the temperature and boiling, proper reaction temperature and time are controlled, so that starch is plasticized, and aggregate particles are completely dispersed into biological latex dispersion liquid with high specific surface area and binding capacity.

In addition, in the whole preparation process, firstly, the starch raw material is not limited, and can be various plant native starches such as corn starch, cassava starch and the like, and can also be various modified starches such as oxidized starch, modified starch, phosphate starch and the like, so that the wide selection range of materials is realized, and only different adding amount ratios of the starch crosslinking agent and the starch plasticity conversion agent are required to be adjusted according to different starch raw materials; secondly, the reaction conditions and reaction equipment are simple, the reaction conditions are loose, the heating can be stopped when the normal pressure and the cooking temperature are raised to 90-95 ℃ without adjusting the pH value, the continuous heat preservation at the temperature of more than 90 ℃ is not needed, and the related operation can be realized only by a reaction kettle with a stirrer; moreover, the preparation process is short in time and high in efficiency, only 2 reaction auxiliary agents are needed to be added, the operation is simple, the whole preparation process is less than 60min, and the actual reaction time is only about 40 min.