Check patentability & draft patents in minutes with Patsnap Eureka AI!

High-viscosity hydroxypropyl methyl cellulose and preparation method thereof

A hydroxypropyl methyl cellulose, high viscosity technology, applied in the field of high viscosity hydroxypropyl methyl cellulose and its preparation, can solve problems such as affecting product safety, reducing the viscosity of finished products, and residual organic solvents, and improving the The effect of etherification reaction efficiency, viscosity increase and methoxy value increase

Inactive Publication Date: 2019-02-15
宁夏瑾成生物科技有限公司
View PDF7 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Most of this method will use solid alkali, which will cause local exotherm and cause the degradation of the degree of polymerization to reduce the viscosity of the finished product. After the reaction, an acid with a corresponding molar ratio must be added to neutralize the excess alkali, which will also lead to a decrease in the viscosity of the finished product.
In addition, because this method needs to use a large amount of organic solvents, it not only increases the cost, but also has the problem of organic solvent residues, which affects the safety of the product

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • High-viscosity hydroxypropyl methyl cellulose and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0046] Further, the above preparation method also includes the following steps:

[0047] Tail gas recovery and utilization: the tail gas generated in the step "one-step etherification" and the step "two-step etherification" is condensed and returned to the reactor to participate in the etherification reaction. The tail gas is mainly composed of dimethyl ether and a small amount of monochloromethane. The tail gas is condensed and sent back to the reactor to continue to participate in the reaction, which improves the utilization rate of raw materials and prevents personal injury and environmental pollution caused by the exhaust of the tail gas.

Embodiment 1

[0049] Embodiment 1: get cellulose high-quality refined cotton, its average degree of polymerization is 2400, pulverize, screen wherein fineness is 24 parts of cellulose high-quality refined cotton of 180 μm~200 μm, join in the N 2 Replaced to an oxygen content of ≤0.5% (volume), and N 2 Punch to 0.1MPa reactor, add 12 parts of sodium hydroxide solution with a concentration of 48%-52% (weight) into the reactor in the form of spraying, control the alkalization reaction temperature at 15°C-45°C, and react for 0.5h ~1h. Add 10 parts of propylene oxide, 27 parts of monochloromethane, and 21 parts of dimethyl ether into the reaction kettle that has completed the alkalization reaction, control the etherification reaction temperature at 33°C to 55°C, and increase the reaction temperature after 1h to 1.5h of reaction To 60 ℃ ~ 90 ℃, react for 1.5h ~ 2h, to get the reaction product. After the reaction product is fully washed with hot water at 75°C to 95°C, it is dried with dry hot ai...

Embodiment 2

[0053] Embodiment 2: get cellulose high-quality refined cotton, its average degree of polymerization is 2600, pulverize, screen wherein fineness is 24 parts of cellulose high-quality refined cotton of 180 μm~200 μm, join in the N 2 Replaced to an oxygen content of ≤0.5% (volume), and N 2 Punch to 0.1MPa reactor, add 30 parts of sodium hydroxide solution with a concentration of 48%-52% (weight) into the reactor in the form of spraying, control the alkalization reaction temperature at 15°C-45°C, and react for 0.5h ~1h. Add 12.5 parts of propylene oxide, 33 parts of monochloromethane, and 27 parts of dimethyl ether into the reaction kettle that has completed the alkalization reaction, and control the etherification reaction temperature at 33°C to 55°C. After reacting for 1h to 1.5h, raise the reaction temperature To 60 ℃ ~ 90 ℃, react for 1.5h ~ 2h, to get the reaction product. After the reaction product is fully washed with hot water at 75°C to 95°C, it is dried with dry hot a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Viscosityaaaaaaaaaa
Bulk densityaaaaaaaaaa
Viscosityaaaaaaaaaa
Login to View More

Abstract

The invention discloses hydroxypropyl methyl cellulose which has viscosity of greater than or equal to 200,000mPa.s at 20+ / -0.1 DEG C, insoluble matter in water of less than or equal to 0.50%, and stacking density of greater than or equal to 0.35g / cm<3>. The invention further discloses a preparation method of the hydroxypropyl methyl cellulose. The preparation method comprises the steps of takingdimethyl ether as a diluent, alkalizing high quality cellulose refined cotton with a high polymerization degree in an N2 atmosphere, allowing the refined cotton to be contacted with methane chloride and epoxy propane for etherification, performing hot water washing, purification, and hot air drying to produce the hydroxypropyl methyl cellulose. Since the method is applied to prepare the hydroxypropyl methyl cellulose, oxidative degradation of oxygen and the hydroxypropyl methyl cellulose is avoided; the degradation of the hydroxypropyl methyl cellulose due to heat release of an acid-base neutralization reaction and acidolysis of the hydroxypropyl methyl cellulose due to introduction of excessive acid are avoided; and the hydroxypropyl methyl cellulose with high viscosity, high purity, highstacking density and low level of the insoluble matter in the water is produced by using an appropriate substance proportion, selecting an appropriate reaction temperature and reaction time and controlling a reaction rate.

Description

technical field [0001] The invention belongs to the technical field of cellulose preparation, and in particular relates to a high-viscosity hydroxypropyl methylcellulose and a preparation method thereof. Background technique [0002] High-viscosity hydroxypropyl methylcellulose is mainly used in the construction industry as a thickener, water-retaining agent, and retarder for cement mortar to make the mortar pumpable. It can be used as a binder in plaster, gypsum, putty powder or other building materials to improve spreadability and prolong work time. It can be used as paste tile, marble, plastic decoration, paste reinforcement, and can also reduce the amount of cement. However, currently on the market, there are few high-viscosity hydroxypropyl methylcellulose that can be industrially produced, especially high-viscosity hydroxypropyl methylcellulose with a viscosity ≥ 200,000 mP a.s. [0003] In the process of preparing alkali cellulose, the presence of oxygen will cause ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C08B11/193
CPCC08B11/193
Inventor 仝西元武金龙韩凤兰
Owner 宁夏瑾成生物科技有限公司
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com