阅读说明：本技术 一种精制棉蒸煮控制降聚的生产方法 (Production method for controlling depolymerization during cooking of purified cotton ) 是由 周航旭 范宗清 范金涛 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种精制棉蒸煮控制降聚的生产方法,包括如下步骤：a、选料；b、除杂；c、浸渍：将质量浓度为1～2.5%的氢氧化钠溶液、0.1～0.2%的表面活化剂、0.1～0.2%环酮化合物、0.2～0.5%三氧化硫和30%双氧水混配成蒸煮剂,将蒸煮剂均匀喷洒到棉短绒中,液比为1：2.5～4.0；d、预处理：将三乙醇胺、碳酸钠、硫酸铜和氧化镁,按等比例复配成质量浓度为0.2～0.5%蒸煮复合助剂,连同浸渍处理后的棉短绒投放到蒸球中,并加温至70℃,停止加温,进行空转预处理40～60min；e、蒸煮；f、蒸球降温,本发明优点是：有效地控制了蒸煮过程中的降聚,可以获得高聚合度的纤维；采用分段蒸煮,避免了传统一步蒸煮方式造成的降聚难以控制的弊端,可以有效控制降聚。(The invention discloses a production method for controlling depolymerization during cooking of purified cotton, which comprises the following steps: a. selecting materials; b. removing impurities; c. dipping: mixing a sodium hydroxide solution with the mass concentration of 1-2.5%, a surface active agent with the mass concentration of 0.1-0.2%, a cyclic ketone compound with the mass concentration of 0.1-0.2%, sulfur trioxide with the mass concentration of 0.2-0.5% and hydrogen peroxide with the mass concentration of 30% to prepare a cooking agent, uniformly spraying the cooking agent into cotton linters, wherein the liquor ratio is 1: 2.5 to 4.0; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide into a cooking compound auxiliary agent with the mass concentration of 0.2-0.5% in equal proportion, putting the cooking compound auxiliary agent and the impregnated cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 40-60 min; e. steaming and boiling; f. the invention has the advantages that: the degradation and polymerization in the cooking process are effectively controlled, and the fiber with high polymerization degree can be obtained; the adoption of segmented cooking avoids the defect that the polymerization reduction is difficult to control caused by the traditional one-step cooking mode, and can effectively control the polymerization reduction.)

1. A production method for controlling depolymerization during cooking of purified cotton is characterized by comprising the following steps:

a. selecting materials: selecting cotton linters without three-silk impurities, wherein the fiber length of the cotton linters is 13-15 mm, and the maturity is more than 80%;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: mixing a sodium hydroxide solution with the mass concentration of 1-2.5%, a surface active agent with the mass concentration of 0.1-0.2%, a cyclic ketone compound with the mass concentration of 0.1-0.2%, sulfur trioxide with the mass concentration of 0.2-0.5% and hydrogen peroxide with the mass concentration of 30% to prepare a cooking agent, uniformly spraying the cooking agent into cotton linters, wherein the liquor ratio is 1: 2.5 to 4.0;

d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide into a cooking compound auxiliary agent with the mass concentration of 0.2-0.5% in equal proportion, putting the cooking compound auxiliary agent and the impregnated cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 40-60 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 30-40 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 20-30 min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~And (3) rapidly cooling the interior of the rotary spherical digester by using 15 ℃ condensed water, reducing the pressure of the rotary spherical digester to zero within 8-15 min, reducing the temperature to below 60 ℃, opening a cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

2. The method for producing refined cotton by cooking and controlling depolymerization according to claim 1, wherein: 2.5-4 parts of sodium hydroxide solution, 0.001-0.003 part of surfactant, 0.0005-0.002 part of cyclic ketone compound, 0.002-0.005 part of sulfur trioxide and 0.002-0.005 part of hydrogen peroxide.

3. The method for producing refined cotton by cooking and controlling depolymerization according to claim 1, wherein: 0.005-0.01 part of cooking compound additive.

4. The method for producing refined cotton by cooking and controlling the degradation of polymerization as claimed in claim 1, 2 or 3, wherein: the surfactant is ethylenediaminetetraacetic acid.

5. The method for producing refined cotton by cooking and controlling the degradation of polymerization as claimed in claim 1, 2 or 3, wherein: the cyclic ketone compound is any one or more than one of naphthoquinone, anthraquinone or anthrone.

6. The method for producing refined cotton by cooking and controlling the degradation of polymerization as claimed in claim 1, 2 or 3, wherein: the cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone according to equal proportion.

7. The method for producing refined cotton by cooking and controlling the degradation of polymerization as claimed in claim 1, 2 or 3, wherein: the cotton linter accounts for 1 part.

Technical Field

The invention relates to the technical field of purified cotton production processes, in particular to the technical field of purified cotton production cooking processes.

Background

The refined cotton is prepared by refining cotton linters which are used as raw materials and are steamed and boiled by an alkaline method, is a basic material for preparing ether cellulose, nitrocellulose, cellulose acetate and nano cellulose, is widely applied to various fields of food, medicine, clothing, war industry, daily chemicals, plastics, electronics, paper making, metallurgy, aerospace and the like, and is an indispensable new material for national economic development. As the traditional high-temperature alkaline cooking process is difficult to control the degradation of the slurry, the production of high-viscosity high-polymer is very difficult, namely, the viscosity is over 2200mPa.s and the polymerization degree is over 2800, and the upgrading of the refined cotton to the high-viscosity high-polymer is restricted.

The method for producing the refined cotton with the ultrahigh viscosity is disclosed in Chinese patent CN201110141806.9 and the process for producing the refined cotton with the ultrahigh viscosity is disclosed in Chinese patent CN201310140702.5, wherein sodium alkyl benzene sulfonate emulsifier, sodium chlorite and hydrogen peroxide are combined for bleaching in the cooking process, and the viscosity produced by the process is only more than 1500mPa & s.

Chinese patent CN201210295256.0 relates to a preparation method of refined cotton with extra high viscosity and a production process of refined cotton with extra high viscosity of Chinese patent CN200410013451.5, wherein the viscosity of the refined cotton prepared by the method is more than 800 mPa.s.

Chinese patent CN200610068484.9 discloses a cotton pulp with high polymerization degree and a method for preparing the cotton pulp with high polymerization degree, the invention is characterized in that hydrogen peroxide, magnesium sulfate, sodium silicate cooking auxiliary agent and peregal and sodium dodecyl benzene sulfonate are used as penetrant, and chlorination bleaching is adopted for bleaching.

The above cooking processes all focus on the use of surfactants, mainly on enhancing the penetration of the lye during cooking and lack of effective control over depolymerization.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a production method for controlling the degradation of refined cotton by cooking, which controls the degradation of polymerization degree in the cooking process by reducing the activation energy of lignin hydrolysis reaction, regulating the alkaline hydrolysis reaction rate of cellulose and controlling the degradation of polymerization degree so as to realize that the polymerization degree of cooking alkalization reaches over 2950 and ensure that the polymerization degree of a finished refined cotton product is over 2800.

The technical solution adopted by the invention to solve the technical problems is as follows:

a production method for controlling depolymerization during cooking of purified cotton comprises the following steps:

a. selecting materials: selecting cotton linters without three-silk impurities, wherein the fiber length of the cotton linters is 13-15 mm, and the maturity is more than 80%;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: mixing a sodium hydroxide solution with the mass concentration of 1-2.5%, a surface active agent with the mass concentration of 0.1-0.2%, a cyclic ketone compound with the mass concentration of 0.1-0.2%, sulfur trioxide with the mass concentration of 0.2-0.5% and hydrogen peroxide with the mass concentration of 30% to prepare a cooking agent, uniformly spraying the cooking agent into cotton linters, wherein the liquor ratio is 1: 2.5 to 4.0;

d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide into a cooking compound auxiliary agent with the mass concentration of 0.2-0.5% in equal proportion, putting the cooking compound auxiliary agent and the impregnated cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 40-60 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 30-40 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 20-30 min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: the method comprises the steps of pouring condensate water of 10-15 ℃ into the rotary spherical digester to rapidly cool the rotary spherical digester, reducing the pressure of the rotary spherical digester to zero within 8-15 min, reducing the temperature to be below 60 ℃, opening a rotary spherical digester cover, recovering alkali liquor, pouring cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

The patent refers to the field of' compositions of cotton linters in 1 part.

This patent the sodium hydroxide solution is 2.5 ~ 4 parts, surfactant 0.001 ~ 0.003 part, cyclic ketone compound 0.0005 ~ 0.002 part, sulfur trioxide 0.002 ~ 0.005 part and hydrogen peroxide solution 0.002 ~ 0.005 part.

The patent refers to the field of 'compositions of macromolecular compounds'.

The surfactant described in this patent is ethylenediaminetetraacetic acid.

The cyclic ketone compound described in this patent is any one or more of naphthoquinone, anthraquinone, or anthrone.

The cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone according to equal proportion.

The invention adopts the technical proposal to achieve the following beneficial effects:

1. the invention sets a pretreatment procedure before cooking, thus improving the permeability of alkali liquor. Meanwhile, the temperature in the rotary spherical digester is quickly reduced after the cooking is finished, and the slurry is poured out of the rotary spherical digester and is cooled by normal-temperature water, so that further oxidation polymerization reduction caused by overhigh temperature of the slurry is avoided, and the degree of polymerization of cooking alkalization is ensured;

2. the reaction effect is improved by adopting a plurality of auxiliary agents to compound the cooking agent, the polymerization reduction in the cooking process is effectively controlled, and the fiber with high polymerization degree can be obtained;

3. the adoption of segmented cooking avoids the defect that polymerization reduction is difficult to control caused by the traditional one-step cooking mode, and can effectively control polymerization reduction under the protection action of the auxiliary agent.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1:

a production method for controlling depolymerization during cooking of purified cotton comprises the following steps:

a. selecting materials: 4000Kg of cotton linter without three-silk impurities is selected, the fiber length of the cotton linter is 13-15 mm, and the maturity is over 80 percent;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: 10000Kg of sodium hydroxide solution with the mass concentration of 1%, 4Kg of ethylene diamine tetraacetic acid with the mass concentration of 0.1%, 2Kg of naphthoquinone with the mass concentration of 0.1%, 8Kg of sulfur trioxide with the mass concentration of 0.2% and 8Kg of hydrogen peroxide with the mass concentration of 30% are mixed into a cooking agent, and the cooking agent is uniformly sprayed into cotton linters, wherein the liquid ratio is 1: 2.5;

d. pretreatment: compounding triethanolamine 5Kg, sodium carbonate 5Kg, copper sulfate 5Kg and magnesium oxide 5Kg into a cooking compound assistant with a mass concentration of 0.2%, putting the compound assistant and the impregnated cotton linter into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 50 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to 35 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 25min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~And (3) rapidly cooling the interior of the rotary spherical digester by using 15 ℃ condensed water, reducing the pressure of the rotary spherical digester to zero within 10min, reducing the temperature to below 60 ℃, opening a cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

By adopting the cooking process, the obtained cooking polymerization degree is 2968.

Example 2:

a production method for boiling, directionally controlling and reducing polymerization of refined cotton comprises the following steps:

a. selecting materials: 4000Kg of cotton linter without three-silk impurities is selected, the fiber length of the cotton linter is 13-15 mm, and the maturity is over 80 percent;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: 12000Kg of sodium hydroxide solution with the mass concentration of 2 percent, 6Kg of ethylene diamine tetraacetic acid with the mass concentration of 0.15 percent, 6Kg of anthraquinone with the mass concentration of 0.15 percent, 12Kg of sulfur trioxide with the mass concentration of 0.4 percent and 12Kg of hydrogen peroxide with the mass concentration of 30 percent are mixed into a cooking agent, and the cooking agent is evenly sprayed into cotton linters, wherein the liquid ratio is 1: 3;

d. pretreatment: compounding triethanolamine 7.5Kg, sodium carbonate 7.5Kg, copper sulfate 7.5Kg and magnesium oxide 7.5Kg into 0.4% steaming composite assistant, putting the steaming composite assistant and the soaked cotton linter into a rotary spherical digester, heating to 70 ℃, stopping heating, and performing idle running pretreatment for 40 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 30 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 20min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~Cooling the spherical digester rapidly with 15 deg.C condensate water, and steaming for 8minReducing the pressure in the ball to zero, reducing the temperature to below 60 ℃, opening the cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

By adopting the cooking process, the obtained cooking polymerization degree is 3034.

Example 3:

a production method for boiling, directionally controlling and reducing polymerization of refined cotton comprises the following steps:

a. selecting materials: 4000Kg of cotton linter without three-silk impurities is selected, the fiber length of the cotton linter is 13-15 mm, and the maturity is over 80 percent;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: 16000Kg of sodium hydroxide solution with the mass concentration of 2.5%, 9.2Kg of ethylene diamine tetraacetic acid with the mass concentration of 0.2%, 8Kg of anthrone with the mass concentration of 0.2%, 20Kg of sulfur trioxide with the mass concentration of 0.5% and 20Kg of hydrogen peroxide with the mass concentration of 30% are mixed into a cooking agent, and the cooking agent is uniformly sprayed into cotton linters, wherein the liquid ratio is 1: 4;

d. pretreatment: compounding 10Kg of triethanolamine, 10Kg of sodium carbonate, 10Kg of copper sulfate and 10Kg of magnesium oxide into a cooking compound auxiliary agent with the mass concentration of 0.5%, putting the cooking compound auxiliary agent and the impregnated cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 60 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 40 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 30min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~And (3) rapidly cooling the interior of the rotary spherical digester by using 15 ℃ condensed water, reducing the pressure of the rotary spherical digester to zero within 15min, reducing the temperature to below 60 ℃, opening a cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

The cooking polymerization degree obtained by adopting the cooking process is 2907.

Example 4:

a production method for boiling, directionally controlling and reducing polymerization of refined cotton comprises the following steps:

a. selecting materials: 4000Kg of cotton linter without three-silk impurities is selected, the fiber length of the cotton linter is 13-15 mm, and the maturity is over 80 percent;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: 16000Kg of sodium hydroxide solution with the mass concentration of 2%, 8Kg of ethylene diamine tetraacetic acid with the mass concentration of 0.12%, 0.16% of cyclic ketone compound, 11Kg of sulfur trioxide with the mass concentration of 0.4% and 10Kg of hydrogen peroxide with the mass concentration of 30% are mixed into a cooking agent, and the cooking agent is uniformly sprayed into cotton linters, wherein the liquid ratio is 1: 3; the cyclic ketone compound consists of 1Kg of naphthoquinone, 1Kg of anthraquinone and 1Kg of anthrone;

d. pretreatment: compounding triethanolamine 7.5Kg, sodium carbonate 7.5Kg, copper sulfate 7.5Kg and magnesium oxide 7.5Kg into 0.35% composite steaming assistant in equal proportion, putting the composite steaming assistant and the soaked cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 55 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 30 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 20min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~And (3) rapidly cooling the interior of the rotary spherical digester by using 15 ℃ condensed water, reducing the pressure of the rotary spherical digester to zero within 12min, reducing the temperature to below 60 ℃, opening a cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

By adopting the cooking process, the obtained cooking polymerization degree is 2945.

Example 5:

a production method for boiling, directionally controlling and reducing polymerization of refined cotton comprises the following steps:

a. selecting materials: 4000Kg of cotton linter without three-silk impurities is selected, the fiber length of the cotton linter is 13-15 mm, and the maturity is over 80 percent;

b. removing impurities: opening cotton linters, and removing impurities such as sand, stones, cotton hulls and the like through an impurity remover;

c. dipping: 12000Kg of sodium hydroxide solution with the mass concentration of 2.1 percent, 7Kg of ethylene diamine tetraacetic acid with the mass concentration of 0.13 percent, 0.15 percent of cyclic ketone compound, 11Kg of sulfur trioxide with the mass concentration of 0.3 percent and 9Kg of hydrogen peroxide with the mass concentration of 30 percent are mixed into a cooking agent, and the cooking agent is evenly sprayed into cotton linters, wherein the liquid ratio is 1: 3; the cyclic ketone compound is formed by combining 1Kg of naphthoquinone, 1Kg of anthraquinone and 1Kg of anthrone;

d. pretreatment: compounding 10Kg of triethanolamine, 10Kg of sodium carbonate, 10Kg of copper sulfate and 10Kg of magnesium oxide into a cooking compound auxiliary agent with the mass concentration of 0.4%, putting the cooking compound auxiliary agent and the impregnated cotton linters into a rotary spherical digester, heating to 70 ℃, stopping heating, and carrying out idle running pretreatment for 50 min;

e. and (3) cooking:

first-stage heating: uniformly heating the spherical digester to 100-110 ℃, and controlling the heating time to be 40 min;

second-stage heating: uniformly heating the spherical digester to 120-130 ℃, controlling the heating time to be 30min, and keeping the temperature for 20 min;

f. cooling the rotary spherical digester: by pouring 10 into the spherical digester_~And (3) rapidly cooling the interior of the rotary spherical digester by using 15 ℃ condensed water, reducing the pressure of the rotary spherical digester to zero within 10min, reducing the temperature to below 60 ℃, opening a cover of the rotary spherical digester, recovering alkali liquor, pouring out cotton pulp, putting the pulp into a container filled with normal-temperature water, and cooling.

By adopting the cooking process, the obtained cooking polymerization degree is 2936.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.