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422 results about "Chromic anhydride" patented technology

Chromium trioxide is an inorganic compound with the formula CrO3. It is the acidic anhydride of chromic acid, and is sometimes marketed under the same name. This compound is a dark-purple solid under anhydrous conditions, bright orange when wet and which dissolves in water concomitant with hydrolysis.

Non-chromium electrolytic polishing solution for stainless steel and surface polishing process for stainless steel

The invention discloses a non-chromium electrolytic polishing solution for stainless steel and a surface polishing process for stainless steel. The polishing solution mainly comprises alcohol (at least one selected from the group consisting of methanol and ethanol) and acid (at least one selected from the group consisting of sulfuric acid and acetic acid). The surface polishing process for stainless steel provided in the invention comprises the following steps: removal of oil stains, rinsing with ultrasonic vibration, pickling with ultrasonic vibration, alkali washing with ultrasonic vibration, electropolishing, rinsing with ultrasonic vibration, passivation, cleaning and drying. Compared to conventional electrolytic polishing solutions for stainless steel, the polishing solution provided in the invention contains no chromic anhydride, which enables environmental pollution to be reduced and waste liquid to be easy to treat, being an environment-friendly type polishing solution; the polishing solution further contains no expensive phosphoric acid, which enables polishing cost to be reduced and is favorable for the popularization of the electropolishing process for stainless steel. According to results of tests, the polishing solution and the process provided in the invention can effectively remove oxide films and scratches on the surface of stainless steel, enable a workpiece to have an effect of mirror brightness, and effectively enhance the quality of polishing.
Owner:CENT SOUTH UNIV

Coloring liquid and coloring method for chemically coloring stainless steel surface into black

The invention discloses a coloring liquid and a coloring method for chemically coloring a 304 stainless steel surface into black, belonging to the technical field of stainless steel surface treatment, aiming to coat a back film layer on the 304 stainless steel surface, mainly solving the problem that a colored film has poor uniformity and repeatability, and being used for improving the decorative performance, wear resistance and corrosion resistance of stainless steel. The invention mainly includes the prescription of the coloring liquid and the coloring method for coloring the 304 stainless steel surface into black, wherein the coloring liquid mainly comprises main film-forming agents (chromic anhydride and chromium sulfate), an assistant filming-forming agent (sulfuric acid), additives (ferric sulfate, manganese sulfate and cerous sulfate) and water; and the coloring method mainly comprises the steps of electrolysis pretreatment, chemical coloring and hole sealing post-treatment, wherein potential control is adopted in the coloring process. A black stainless steel film obtained by using the coloring liquid and the coloring method has the advantages of uniform colored film, no obvious color difference, bright color, excellent wear resistance and corrosion resistance, good film adhesion, simple and practical coloring method, easily controlled coloring process, good color repeatability and the like.
Owner:CENT SOUTH UNIV

Electrolytic polishing solution for magnesium alloy medical heart stent and surface polishing processing technology of medical heart stent

The invention relates to an electrolytic polishing solution for a magnesium alloy medical heart stent and a surface polishing processing technology of the medical heart stent. The electrolytic polishing solution for the medical heart stent is prepared from alcohol and acid. The magnesium alloy surface polishing processing technology of the medical heart stent comprises the first step of mechanical grinding and polishing, the second step of oil and dirt removing, the third step of ultrasonic vibrating and alkali washing, the fourth step of electrolytic polishing, the fifth step of ultrasonic vibrating and alcohol washing and the sixth step of drying and vacuum sealing storage. A product obtained through the fifth step is dried, and a finished magnesium alloy heart stent with the bright mirror surface is obtained and is stored by a vacuum package bag in a sealed manner. By means of the technical scheme, firstly, chromic anhydride large in toxicity and serious in pollution is not contained, the processing difficulty of the waste polishing solution is lowered, the environment pollution is reduced, and the polishing solution is environmentally friendly; secondly, the requirement of the polishing technology for the temperature range is not high, the effect of polishing the bright mirror surface can be achieved under the room temperature, and therefore the operation cost is greatly reduced; and thirdly, reaction time is short and is 1-10 min. Compared with a traditional polishing technology, the polishing electrolysis time can be greatly shortened, and accordingly energy consumption is effectively reduced.
Owner:JIANGSU FENGYUAN MEDICAL DEVICES CO LTD

Surface processing technique for bacterium resistance, erosion resistance and tarnish resistance of aluminum or aluminum alloy material

The invention relates to a surface processing technique for the bacterium resistance, the erosion resistance and the tarnish resistance of aluminum or aluminum alloy material, comprising the following steps: firstly, degreasing processing is carried out on an aluminum material used as a workpiece, the aluminum material after being degreased is put into an acid solution, the workpiece is used as one pole, an aluminum plate or a lead plate is used as the other pole and is electrified with alternating current, the liquid temperature is kept between 0 DEG C and 30 DEG C, an oxidation film with bacterium resistance, erosion resistance and tarnish resistance is formed on the surface of the aluminum material after oxidation for 10-30 minutes, and finally, the workpiece is taken out and placed in purified water of 90-100 DEG C and closed for 15-20 minutes. The acid solution has the components and the content that each liter of acid solution contains 80-150 grams of industrial grade sulfuric acid, 2-10 grams of chromic anhydride and 0.1-1.5 grams of water soluble silver salt. The surface of the aluminum material after being processed by the invention is provided with a layer of oxidation film, silver compounds with bacterium resistance and tarnish resistance, such as silver chromate, silver dichromate and the like, are formed in the film, then the film is closed by hot water, and the erosion resistant performance is more excellent.
Owner:CHANGZHOU GARDENSUN ANTI BACTERIAL MATERIALS TECH

Method for treating chromite by sulfuric acid leaching

The invention discloses a method for treating chromite by sulfuric acid leaching, which comprises the following steps of: grinding the chromite into mineral powder, adding sulfuric acid into the mineral powder, stirring the mixture, and adding an oxidant into the mixture, wherein the oxidant is chromic anhydride, potassium chlorate or ammonium persulphate, and the adding amount of the oxidant is 0.2 to 7 percent of the mass of the mineral powder; heating the mixture at the temperature of between 120 and 190 DEG C for 30 to 90 minutes under the pressure of between 0.2 and 1.2MPa, filtering the reaction products after the reaction is finished, and performing solid-liquid separation, wherein the filter residue is directly used as a raw material for melting silicon iron; and removing iron from the filtrate to obtain chromium sulfate solution, and further preparing chromium sulfate by a direct crystallization method. Compared with the prior art, the method has the most remarkable characteristics of short process flow and no 'three-waste' emission. The filter residue does not contain hexavalent chromium, and the weight of the filter residue is light and only about 10 percent of the weight of the chromite, so the filter residue can be used as the raw material for melting the silicon iron.
Owner:NORTHEASTERN UNIV

Method for chroming stainless steel conductive roller

InactiveCN102021621ASolve hard-to-remove problemsAvoid scratchesJewelleryCopper platingCorrosion
The invention relates to a method for chroming a stainless steel conductive roller. The method comprises roller body surface polishing, oil removing, cleaning, roughing and peak clipping treatment and is characterized by comprising the following steps of: adding 135+/-10 grams of nitric acid (HNO3), 165+/-5 grams of hydrogen chloride (HCl), 30+/-3 grams of hydrogen fluoride (HF) and 2 grams of hexamethylene tetramine (C6H12N4) sequentially into 770 millimeters of water; stirring the mixture uniformly; preparing peak-clipping burr-removing liquid at normal temperature; scrubbing the surface of the roughened layer of the conductive roller for 15 to 20 minutes by using the peak-clipping burr-removing liquid; preparing chroming liquid in a ratio of chromic anhydride (CrO3) to sulfuric acid (H2SO4) of 100 to 1.15; and after washing the stainless steel conductive roller cleanly, placing the cleaned stainless steel conductive roller into a horizontally chroming tank to power on and perform electroplating. The method has the advantages of: by a peak-clipping burr-removing liquid corrosion method, the problem that waste edges and scraps after the roughing process are difficult to remove due to high toughness of stainless steel is solved and the chromed stainless steel conductive roller does not scratch the surface of a steel plate due to the burr; a chroming layer is bonded with a matrix firmly by the electroplating process, so the chroming layer does not fall off and has high wear resistance; the stainless steel conductive roller has a long service life, a short repair cycle of only 2 to 3 days and cost of one fifth of that of a copperized conductive roller.
Owner:本溪市通宝冶金设备制造有限公司

Surface treating method of stainless steel shell

The invention solves a technical problem of providing a stainless steel shell surface treatment method having short processing period, nontoxic processing and a beautiful shell after treatment. The stainless steel shell surface treatment method comprises the following: (1) a step of liquid shot blast, in which glass microballoons and water are mixed with a 10 to 15g/L corrosion inhibitor for shot blast according to a principle that the ratio of the microballoons to the water is between 1 to 5 and 1 to 8; (2) a step of passivation, in which a stainless steel shell is soaked in a 300 to 350g/L concentrated nitric acid or a 5 to 50 g/L dilute solution of chromic anhydride; and (3) sealing, in which confining liquid is spread on the surface of the stainless steel shell and then dried. The method has cost lower than that of the prior surface treatment technique and can effectively remove scale generated during welding; the appearance of the stainless steel shell is a mat surface which is fine and elegant and has strong dirt resistance and prevents hands touching the surface from leaving impression; and the process does not generate toxic substances and is good for health and environment protection. The method is particularly suitable for surface treatment of stainless steel shells of storage batteries.
Owner:SICHUAN CHANGHONG ELECTRIC CO LTD

New technology for plating golden yellow on automotive hub

The invention discloses new technology for plating golden yellow on an automotive hub, which comprises the technical steps: galvanizing, pre-plating copper, brightly plating copper, plating nickel, plating golden yellow, and the like. The chemical composition formula contained in each L of plating solution is that: galvanizing solution comprises 220 to 240g of potassium chloride, 40 to 55g of zinc chloride, 30 to 35g of boric acid, and 15 to 25ml of brightener; copper pre-plating solution comprises 70 to 85g of copper phosphate, 280 to 350g of phosphor copper potassium, 4 to 6ml of ammonia water, and 3 to 5ml of brightener; the bright copper plating solution comprises 200 to 220g of copper sulfate, 70 to 90g of sulfuric acid, 0.06 to 0.08g of chloride ion, and 4 to 8ml of brightener; nickel plating solution comprises 260 to 300g of nickel sulfate, 30 to 50g of nickel chloride, 30 to 40g of boric acid, 0.6 to 1ml of brightener, 8 to 12ml of softening agent, and 2 to 4ml of wetting agent; and golden yellow plating solution comprises 120 to 140g of imitation gold salt and 2 to 4ml of ammonia water. After the plating, water washing and drying are performed, and a polyurethane paint is sprayed on the surface of the automotive hub. The new technology for plating golden yellow on the automotive hub radically eliminates the damage and environmental pollution of sodium cyanide and chromic anhydride to human bodies; the plated golden yellow automotive hub is luxurious and attractive, has strong corrosion resistance, and is suitable for high-class automotive assembly.
Owner:梁新中

Method for detecting chloride ion impurities in high concentration chromic anhydride solution

The invention discloses a method for detecting chloride ion impurities in a high concentration chromic anhydride solution, which comprises the following steps of dispensing the high concentration chromic anhydride solution to be detected to be placed in a titration glass, dropwise adding an alkaline adjusting solution into the chromic anhydride solution under the uniform stirring of an automatic potentiometric titrator, adjusting potential of hydrogen (pH) value of the solution to be detected to 4.5 to 5, then setting the maximum jumping point detected by the automatic potentiometric titrator as a titration end point, starting the automatic potentiometric titrator, titrating by a silver nitrate standard solution, performing blank titration of corresponding reagents, and calculating content of chloride ions according to a standard formula. The alkaline solution is a 25% sodium hydroxide solution, and the concentration of the silver nitrate standard solution is 0.0400mol/L. The method for detecting chloride ion impurities in the high concentration chromic anhydride solution has the advantages that the conventional automatic potentiometric titrator is used, adjustment is performed by addition of the sodium hydroxide solution, extreme influences of solution color on the detection are eliminated, quantitative detection of the chloride ion impurities in the high concentration chromic anhydride solution which is repeatedly used is achieved, and the rapid detection requirement in the industrial production process is met.
Owner:ZHENGZHOU AIRCRAFT EQUIP

Process method for carrying out surface treatment on electrolysis copper foil, and cooper foil treated by using the same

ActiveCN103469267AExcellent chemical corrosion resistanceExcellent room temperature oxidation resistanceElectrolysisAdhesive
The present invention discloses a one-time surface treatment method for electrolysis copper foil. The process method comprises: 1, coursing solution preparation: carrying out mixing dissolving on cathode cooper, sulfuric acid and soft water to produce a copper sulfate solution, adding an additive A to the copper sulfate solution, completely mixing, and adding the obtained mixture to a coursing tank to be subjected to electroplating; 2, curing solution preparation: carrying out mixing dissolving on cathode cooper, sulfuric acid and soft water to produce a copper sulfate solution, and adding the copper sulfate solution to a curing tank to be subjected to electroplating; 3, zinc plating alloy solution preparation and a passivation treatment: respectively dissolving zinc sulfate, chromic anhydride and phosphoric acid, adding the zinc sulfate solution to a chromic acid and phosphoric acid mixed solution, adding an additive D solution to the obtained mixing solution in a dropwise manner while adjusting the pH value by using sodium hydroxide, completely mixing, and then adding the obtained mixture to a zinc plating alloy tank to be subjected to electroplating; and 4, spray coating of an adhesive: dissolving an adhesive in water, and carrying out cycle spray coating of the adhesive on the surface of copper foil. According to the present invention, the process is simple, the steps are less, passivation solution components are stable, and the treated electrolysis copper foil has excellent physical properties.
Owner:江西省江铜铜箔科技股份有限公司
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