Efficient thermal stripping method for photo-sensitive resist on surface of waste nickel net

Abstract

The invention discloses an efficient thermal stripping method for photo-sensitive resist on the surface of a waste nickel net, which comprises the following steps: placing the nickel net in an atmosphere furnace after gas condensation transformation, sequentially controlling the gas atmosphere in the furnace to be nitrogen and air, roasting for 0.5-5 hours and 0.5-1 hour under the constant temperature condition of 200-600 DEG C, condensing the photo-sensitive resist into a photo-sensitive resist reclaimed material after thermal stripping, and recycling the photo-sensitive resist reclaimed material after thermal stripping. And the degummed nickel net can be directly used as a nickel resource. In the treatment process of the method, no wastewater or harmful waste gas is generated, and the method is an efficient treatment method.

Description

Technical Field

[0001] The invention relates to a highly efficient thermal stripping method for photosensitive adhesive on the surface of a waste nickel mesh, belonging to the technical field of metallurgy and waste resource recycling. Background Art

[0002] As a major producer of printing industry in the world, China's printing technology has reached the international advanced level. At present, there are about 4,000 rotary screen printing machines in my country, and the amount of nickel metal in the discarded nickel screens is about 8,000 tons each year, and the scraps in the nickel screen processing process are nearly 400 tons. With the development of nickel ore resources, the situation of my country's import of nickel ore resources has not changed. Therefore, the recycling of nickel screen resources is of great significance. The waste round nickel screens in the textile or printing and dyeing industry are used for textile or printing and dyeing production after surface stripping treatment, or as raw materials for metallurgical production. The reuse of waste nickel screens (as metallurgical raw materials or reuse in textile printing and dyeing or printing industry) requires the removal of the photosensitive colloid on its surface and the dye curing film layer adhered to it, that is, the curing film layer needs to be removed first (which can be referred to as stripping).

[0003] The existing stripping method of waste nickel mesh is to soak and dissolve in a stripping agent solution of a certain temperature and concentration or soak and dissolve in a stripping agent solution and use the ultrasonic cavitation effect of ultrasound (CN109626448B) to enhance the stripping effect; a domestically invented technology is a physical and chemical swelling stripping method, which is as follows: when the nickel mesh is soaked in a stripping solution at a specific temperature, this functional compound quickly wets the surface of the nickel mesh through molecular thermal motion and diffuses and penetrates on the surface of the nickel mesh solidified film, forming a regular directional adsorption arrangement layer at the corresponding micropores or defects on the inner and outer surfaces of the solidified film, and various forces between molecules work together to exert a pulling and stretching effect on the surface of the solidified film opposite to the adhesion force, and the photosensitive solidified film quickly swells and quickly peels off its bonding surface. In addition, an existing pretreatment method for non-ferrous metal metallurgical raw materials is to use a combustion method to remove combustible volatile impurities on the surface of the raw materials. However, it is treated in the atmosphere and cannot be used to treat waste nickel mesh, because it will cause the surface of the waste nickel mesh to become brittle and easy to break due to inhalation of gas or chemical reaction with air components, and it is difficult to completely strip the film. The disadvantages of the existing stripping method are that it must consume chemical solvents, the residual liquid or released gas pollutes the environment, and the cost is high. The stripping effect is not good when the temperature is not very high, and the waste nickel mesh is easy to become brittle and break. Therefore, there is still a lot of room for exploration in the surface stripping technology of waste nickel mesh. Summary of the invention

[0004] The present invention aims to provide an efficient method for thermally stripping the surface photosensitive adhesive of a waste nickel mesh, so as to ensure efficient separation and recovery of nickel resources and the surface photosensitive adhesive, reduce pollution emissions and save water resources.

[0005] To achieve the above object, the present invention adopts the following technical solution: An efficient thermal stripping method for photosensitive adhesive on the surface of a waste nickel mesh comprises the following steps: 1) Inspect the surface of the nickel mesh and remove large particles adhering to the surface; 2) Place the inspected nickel mesh in an atmosphere furnace, evacuate the furnace and introduce nitrogen. The nitrogen introduction rate is controlled at 10-20 mL / min. After nitrogen is introduced, the pressure in the atmosphere furnace is maintained below 0.05 MPa. 3) Under nitrogen protection, heat to 300~600℃, keep constant temperature for 0.5~5h, and melt and recover the photosensitive adhesive on the surface of the nickel mesh; 4) After the constant temperature is completed, stop introducing nitrogen and instead introduce air into the atmosphere furnace. The air flow rate is controlled at 50~70mL / min, and the pressure in the atmosphere furnace is maintained below 0.05 MPa. Continue to maintain the constant temperature for 0.5-1h; after the heating is completed, slowly cool to room temperature, take out the nickel mesh and collect the recycled photosensitive adhesive.

[0006] The recycling principle of the present invention is that according to the boiling points of the components of the photosensitive adhesive, the present invention non-decomposes them in a nitrogen atmosphere and then condenses them to form the photosensitive adhesive recycling material; the non-volatile substances remaining on the surface of nickel are decomposed into CO by the oxygen in the air and the catalytic action of Ni. 2 The gas components are removed to achieve physical separation of the photosensitive adhesive and the nickel mesh. The recycled photosensitive adhesive can be re-proportioned to prepare new photosensitive adhesive coating materials after the components are quantified.

[0007] In summary, the present invention develops a highly efficient thermal stripping technology for waste nickel mesh surface photosensitive adhesive based on physical evaporation and chemical oxidation, which simultaneously realizes the recovery of surface photosensitive adhesive and nickel mesh. This method is different from the traditional burning method and avoids CO, SO 2 ,NO,NO 2 It also simplifies the nickel mesh stripping operation, reduces water resource input and sewage discharge, and does not generate any new three wastes. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The liquid-mass spectrum of the recycled photosensitive adhesive material recovered by the present invention.

[0009] Figure 2 These are the XRD diffraction peaks before and after the nickel mesh is treated.

[0010] Figure 3 This is a morphology diagram of the nickel mesh before and after treatment of the present invention. DETAILED DESCRIPTION

[0011] The photosensitive adhesive stripping process of the present invention is explained below in conjunction with specific embodiments. Example

[0012] The waste nickel mesh mainly comes from the discarded printing nickel mesh of a printing factory in Jiangsu.

[0013] 1) Inspect the surface of 200g nickel mesh to remove large particles such as sawdust, cloth scraps, and adobe attached to the surface; 2) Place the inspected nickel mesh in an atmosphere furnace, evacuate the furnace and introduce nitrogen. The nitrogen introduction rate is controlled at 15 mL / min. After nitrogen is introduced, the pressure in the atmosphere furnace is maintained at 0.05 MPa. 3) Under nitrogen protection, heat to 300~600℃, keep constant temperature for 0.5~5h, and melt and recover the photosensitive adhesive on the surface of the nickel mesh; 4) After the constant temperature is completed, stop introducing nitrogen and instead introduce air into the atmosphere furnace. The air flow rate is controlled at 60mL / min, and the pressure in the atmosphere furnace is maintained at 0.05 MPa. Continue to maintain the constant temperature for 0.5-1h; after the heating is completed, slowly cool to room temperature, take out the nickel mesh and collect the recycled photosensitive resin.

[0014] Process evaluation: The composition of the photosensitive adhesive before treatment can be found in the literature: Wang Chao, Li Li, Huang Yudong. Medium-temperature curing high-strength high-peel solvent-free polyurethane modified epoxy resin structural adhesive [J]. Journal of Natural Science of Heilongjiang University, 2003, (03): 109-111. Figure 1 The mass spectrum of the recycled photosensitive adhesive liquid recovered by the present invention. In the figure, the peaks m / z=141 and 163 belong to the hydrogenation and sodium addition peaks of tetrabutylene diisocyanate; m / z=321 belongs to the monomer hydrogenation peak of poly(butadiene-acrylonitrile); m / z=393, 449 and 493 are the monomer hydrogenation peaks of ethylene oxide-polysulfone and propylene oxide-polysulfone. It shows that the recycled material is mainly a mixture of isocyanate, poly(butadiene-acrylonitrile), alkylene oxide and polysulfone, which proves that the process can effectively recycle the photosensitive adhesive on the surface of the waste nickel mesh.

[0015] Figure 2 The XRD diffraction peaks of the nickel mesh before and after treatment of the present invention. In the figure, before treatment, the nickel mesh is mainly oriented in (200); after treatment, the nickel mesh is mainly oriented in (111), and at the same time, it also contains the diffraction peak of NiO. The main reason for the change in the orientation of the diffraction peaks before and after treatment is that the non-volatile C produced by inert decomposition interacts with the Ni surface to form NiC active substances, which are then transformed into metal Ni and CO in an oxygen atmosphere. 2 , thus changing the peak shape; part of the metal Ni on the surface is oxidized by oxygen in the air to form NiO.

[0016] Figure 3 The morphology of the nickel mesh before (upper) and after (lower) treatment of the present invention is shown. Compared with before treatment, the nickel mesh has good pore uniformity and no residual adhesive is attached, which proves that the adhesive removal process of the present invention is reliable.

Claims

1. An efficient thermal stripping method for photosensitive adhesive on the surface of waste nickel mesh, characterized in that: The following steps are involved: 1) Inspect the surface of the nickel mesh and remove large particles adhering to the surface; 2) Place the inspected nickel mesh in an atmosphere furnace, evacuate the furnace and introduce nitrogen. After nitrogen is introduced, the pressure in the furnace is maintained below 0.05 MPa; 3) Under nitrogen protection, heat to 300~600℃, keep constant temperature for 0.5~5h, and melt and recover the photosensitive adhesive on the surface of the nickel mesh; 4) After the constant temperature is completed, stop introducing nitrogen and instead introduce air into the atmosphere furnace, maintain the pressure in the atmosphere furnace below 0.05 MPa, and continue to maintain the constant temperature for 0.5-1h; after the heating is completed, slowly cool to room temperature, take out the nickel mesh and collect the recycled photosensitive resin.

2. A highly efficient thermal stripping method for photosensitive adhesive on the surface of a waste nickel mesh as claimed in claim 1, characterized in that: In step 2), the nitrogen flow rate is controlled at 10-20 mL / min.

3. A highly efficient thermal stripping method for photosensitive adhesive on the surface of a waste nickel mesh as claimed in claim 1, characterized in that: In step 4), the air intake is controlled at 50-70 mL / min.

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