PRODUCT INTRODUCTION

Hydroxypropyl methylcellulose (Hypromellose), also known as hydroxypropyl methylcellulose, is a type of non-ionic cellulose mixed ether. It is a semi-synthetic, inactive, viscoelastic polymer, often used as a lubricant in ophthalmology, or as an excipient or excipient in oral drugs.

PHYSICAL AND CHEMICAL PROPERTIES

Appearance: white or off-white fibrous or granular powder

Stability: solid is flammable and incompatible with strong oxidants.

Particle size; 100 mesh pass rate greater than 98.5%; 80 mesh pass rate 100%. Special specifications of particle size 40 to 60 mesh.

Carbonization temperature: 280-300℃

Apparent density: 0.25-0.70g/cm3 (usually around 0.5g/cm3), specific gravity 1.26-1.31.

Color change temperature: 190-200℃

Surface tension: 2% aqueous solution is 42-56dyne/cm

Solubility: Soluble in water and some solvents, such as ethanol/water, propanol/water in appropriate proportions. The aqueous solution has surface activity. High transparency, stable performance, different specifications of products have different gel temperatures, solubility varies with viscosity, the lower the viscosity, the greater the solubility, different specifications of HPMC have certain differences in performance, HPMC dissolution in water is not affected by pH value.

PRODUCTION METHOD

The refined cotton cellulose is treated with alkali solution at 35-40℃ for half an hour, squeezed, the cellulose is crushed, and aged appropriately at 35℃, so that the average polymerization degree of the obtained alkali fiber is within the required range. The alkali fiber is put into the etherification kettle, propylene oxide and methyl chloride are added in turn, and etherified at 50-80℃ for 5h, with a maximum pressure of about 1.8MPa. Then add appropriate amounts of hydrochloric acid and oxalic acid to wash the material in hot water at 90℃ to expand the volume. Dehydrate with a centrifuge and wash to neutrality. When the moisture content in the material is less than 60%, dry it with a hot air flow at 130°C to less than 5%, and finally crush it through a 20-mesh sieve to obtain the finished product.

USES

1. Construction industry: As a water retainer and retarder for cement mortar, the mortar has pumpability. In plaster mortar, gypsum, putty powder or other building materials, it is used as an adhesive to improve the spreadability and extend the operability time. It is used as a bonding enhancer for pasting tiles, marble, and plastic decorations, and can also reduce the amount of cement. The water retention property of HPMC prevents the slurry from cracking due to drying too quickly after application, and enhances the strength after hardening.

2. Ceramic manufacturing industry: It is widely used as an adhesive in the manufacture of ceramic products.

3. Paint industry: As a thickener, dispersant and stabilizer in the paint industry, it has good compatibility in water or organic solvents. As a paint stripper.

4. Ink printing: As a thickener, dispersant and stabilizer in the ink industry, it has good compatibility in water or organic solvents.

5. Plastics: used as mold release agent, softener, lubricant, etc.

6. Polyvinyl chloride: used as dispersant in polyvinyl chloride production, and is the main auxiliary agent for suspension polymerization to prepare PVC.

7. Pharmaceutical industry: coating materials; film materials; rate-controlling polymer materials for sustained-release preparations; stabilizers; suspending agents; tablet adhesives; thickeners

8. Others: also widely used in leather, paper products, fruit and vegetable preservation, and textile industries.