39results about How to "Obvious thickening" patented technology

The invention discloses a method for preparing a urea-modified phosphonium salt tanning agent. The preparation of the tanning agent is characterized in that 160-200 parts by mass of a tetrahydroxymethyl phosphonium salt solution is added to a heat-resistant, pressure-resistant and corrosion-resistant tank equipped with a stirrer and a thermometer. in the reaction kettle. Raise the temperature to 70-90°C, adjust pH=4.5-6.5 with alkali, slowly add 25-40 parts by mass of peroxide, react for 2.0-4.0 hours, cool, adjust pH=6.0-6.5, and obtain a light yellow solution. Add 30-60 parts by mass of urea and 150-200 parts by mass of deionized water into another reactor and mix them. Add 10-15 parts by mass of the catalyst, raise the temperature to 40°C-50°C and react for 2.0-3.0 hours, and adjust the pH=5.0-6.0. Add the above-mentioned light yellow solution, heat up to 60-90°C, react for 4.0-6.0 hours, cool down to 30-40°C, slowly add 20-30 parts by mass of peroxide, and react for 1.0-2.0 hours to obtain a light yellow viscous Thick liquid chrome-free main tanning agent for leather.

The invention discloses a degradable starch-degradable chromium-containing leather pulp composite as well as a preparation method and application thereof. The preparation method is characterized by comprising the following steps of: adding 80-100 parts of degradable starch, 60-80 parts of degradable chromium-containing leather pulp, 10-15 parts of hydrochloric acid with concentration being 12mol / L, 80-100 parts of water and 20-25 parts of 25-30%hydrogen peroxide into a reactor with a stirrer, stirring and reacting for 1-3hours at 85-95 DEG C; cooling the reactants to 50 DEG C, slowly adding 3-5 parts of sodium hydrogen sulfite, stirring and reacting for 1-2hours so that the reaction pulp is completely dissolved in water, and then cooling to 25 DEG C; adjusting the pH value of the reactant pulp to 4.0-5.0 by using a NaOH solution, stirring and reacting for 1-2hours, to finally obtain the degradable starch-degradable chromium-containing leather pulp composite. The problems that in the existing preparation process, starch is not modified uniformly, the oxidization selectivity is poor and production cost is high are solved. After the degradable starch-degradable chromium-containing leather pulp composite is used as leather filler for filling leather, the filled leather is thickened obviously and has high physical mechanical strength, soft and full handfeel, and therefore, the degradable starch-degradable chromium-containing leather pulp composite has excellent filling effect.

The invention relates to a method for synthesizing high molecular retanning dyeing auxiliary agents through enzyme catalysis, which comprises the following steps: dissolving p-aminobenzene sulfonic acid and 2, 3-dihydroxy naphthalene-6-sodium sulfonate into de-ionized water, using a sodium bicarbonate solution for regulating the pH value of the system, and finally, obtaining the retanning dyeing auxiliary agents through co-polymerization reaction carried out under the horse radish peroxidase (HRP) catalysis. The invention uses HRP as catalysts of the polymerization reaction, and the HRP has the advantages of high efficiency, high selectivity and environment protection when being used for catalyzing the polymerization. The invention has the advantages that phenols or arylamines can carry out polymerization in ortho positions or para positions of hydroxide groups and amino groups for forming a polymer with directly connected C-C structures and large pi conjugated systems, the formaldehyde pollution in the traditional synthesized retanning agents is avoided, and at the same time, the products with the conjugated systems contain a large number of auxochromic groups such as -NH2, -OH and -SO3H and the like. Retanning leather is full and soft, and the dye absorption rate is higher than 99 percent, and in addition, the retanning dyeing auxiliary agents have obvious dyeing aid effect.