4 results about "Chromate salt" patented technology

The invention belongs to the technical field of building materials, and relates to disposable redispersible asphalt powder as well as a preparation method and application thereof. The asphalt powder comprises the following components in parts by weight: 100 parts of asphalt, 2-20 parts of an emulsifier, 5-20 parts of protective colloid, 0.5-40 parts of a stabilizer, 1-10 parts of a slow-release complexing agent and 5-20 parts of an anti-caking agent. The slow-release complexing agent is one or more of activated modified borax, modified boric acid, modified sodium silicate or chromate, and the activation mode of the slow-release complexing agent is that an inorganic salt aqueous solution and a part of the protective colloid solution are mixed in advance. The specific slow-release complexing agent is introduced and forms a synergistic system with the emulsifier, the protective colloid and the like, so that the asphalt powder can be quickly redispersed when meeting water for construction for the first time, the complexing agent and a hydrophilic component are subjected to irreversible reaction after drying and film forming, redispersibility is permanently lost, and the technical problem that a traditional product is poor in water resistance after film forming is effectively solved. The product is suitable for the fields of waterproof and anticorrosive dry-mixed mortar, asphalt coiled material base layer treating agents and the like.

The invention provides a steel wire quenching process, and relates to the technical field of heat treatment, and the steel wire quenching process comprises the following steps: S1, pretreatment: a steel wire to be quenched is sequentially subjected to alkali washing, acid pickling and passivation treatment, the alkali washing treatment is performed for 5-8 min by using a 8%-12% sodium hydroxide solution at 50-70 DEG C, the acid pickling treatment is performed for 3-5 min by using a 15%-20% hydrochloric acid solution at 20-30 DEG C, the passivation treatment is performed for 1-2 min by using a chromate solution at room temperature, and then the steel wire is aired; and S2, induction heating: the pretreated steel wire is heated to 880-920 DEG C by a medium-frequency induction heating device in a segmented mode, heat preservation is conducted for 5-8 s, and complete austenitizing is achieved. In the method, the temperature control precision is improved, the surface temperature difference of the steel wire is smaller than or equal to + / -5 DEG C through induction heating, the austenitizing uniformity is improved, the tensile strength fluctuation range of the quenched steel wire is reduced to be smaller than or equal to 5%, and the product percent of pass is high. The water-soluble quenching liquid is free of oil smoke emission, the cyclic utilization rate is larger than or equal to 90%, the COD value of waste liquid is smaller than or equal to 500 mg / L, compared with mineral oil quenching, pollutant emission is reduced by 92%, and the salt bath quenching salt slag generation amount is reduced to zero.

This invention discloses a corrosion-resistant and recyclable tinplate food container and its preparation method, comprising a food can with a threaded post at the center of its top. A sealing cap is connected to the top of the threaded post via an internally threaded tube. A connecting ring is provided on one side wall of the sealing cap. The advantages are as follows: Through the design of the weld seam, electroplating layer, and passivation layer, after welding the joint, the weld seam can be electroplated using a tin salt electrolyte, filling any damage to the tin layer. Then, a secondary passivation process using a chromate passivation solution is performed on the weld seam to form a passivation layer, effectively connecting the weld seam to the original passivation layer and preventing localized corrosion at the weld seam. The design of the connecting ring, connecting ring 2, and carrying rope facilitates direct hand-carrying of the food can when carrying the device, preventing the loss of the sealing cap and facilitating efficient recycling of the tinplate.

The application relates to the technical field of medical intermediates, in particular to a preparation method of 2-fluoro-3-nitrobenzoic acid, which comprises the following steps: S1: 2-fluoro-3-nitrotoluene is subjected to reflux reaction with DMF-DMA to obtain an intermediate (E)-2-(2-fluoro-3-nitrophenyl)-N,N-dimethylvinyl-1-amine; S2: the intermediate is dissolved in an aprotic solvent, is subjected to low-temperature ozone oxidation, is subjected to vacuum distillation to remove the solvent, and is subjected to acid system crystallization to obtain 2-fluoro-3-nitrobenzoic acid. The route realizes efficient conversion of methyl into carboxyl through an "activation-directional oxidation" strategy, and avoids the safety and environmental protection problems caused by strong oxidation systems such as potassium permanganate and bichromate. Ozone oxidation is high in selectivity and mild in reaction, can effectively inhibit the side reaction of the aromatic ring nitro and the fluorine substituent, and the product is high in purity.