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CN-122008095-A - Stacked abrasive cloth with chemical crosslinking network binder

CN122008095ACN 122008095 ACN122008095 ACN 122008095ACN-122008095-A

Abstract

The application relates to the technical field of stacked abrasive sand cloth with a chemical crosslinking network bonding agent, discloses a device named as a stacked abrasive sand cloth with a chemical crosslinking network bonding agent, and aims to solve the problems that the hardness and toughness of the conventional sand cloth bonding agent are unbalanced and the thermal stability is insufficient under high-temperature heavy load. The device is characterized by comprising a flexible substrate layer, a primer bonding layer, a chemical crosslinking stacked abrasive layer and a reinforced paint layer, wherein the bonding agent of the stacked abrasive layer is formed by a multi-dimensional chemical crosslinking network by matrix resin, a crosslinking reinforcing component, a flexible modifying component and functional fillers. By adopting the technical scheme, the abrasive cloth has the advantages that the heat resistance is improved by utilizing the high-density cross-linked network, and the ordered self-sharpening and extremely high interface bonding strength of abrasive clusters are realized by matching with the flexible component to absorb impact energy, so that the service life of the abrasive cloth is obviously prolonged, and the consistency of a processing surface is improved.

Inventors

  • HUANG HAIMING
  • CHEN XUWU
  • ZHENG JIE
  • YIN TING

Assignees

  • 常州市金牛研磨有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (10)

  1. 1. The stacked abrasive sand cloth with the chemical crosslinking network binder is characterized by sequentially comprising a flexible substrate layer (1), a primer bonding layer (2) coated on the surface of the flexible substrate layer (1), a chemical crosslinking stacked abrasive layer (3) formed by stacked abrasive clusters (31) and a reinforced paint layer (4) coated between the stacked abrasive clusters (31) from bottom to top; Wherein the stacked abrasive clusters (31) are formed by consolidation of abrasive particles (311) with a bonding agent (312) having a chemically crosslinked network; The binding agent (312) with a chemically crosslinked network is structured to form a three-dimensional interpenetrating network structure by chemical reaction on a molecular scale from: a matrix resin component which adopts liquid phenolic resin with the number average molecular weight distribution between 600 and 1000 and the free phenol content of less than 2 percent; A cross-linking reinforcing component which adopts a polyfunctional isocyanate prepolymer or a linear polymer containing active epoxy groups, and forms a transverse chemical bond connection with hydroxyl groups in the matrix resin through an addition reaction or a condensation reaction, so that the cross-linking density of the bonding agent is improved by 30 to 50 percent compared with that of a single-component phenolic resin; the flexible modification component adopts amino-terminated nitrile rubber microspheres, hydroxyl-terminated nitrile rubber microspheres or polyester polyol with hyperbranched structure, and is embedded into crosslinking lattice points of the matrix resin in a chemical anchoring manner; and a functional filler component uniformly dispersed in a molecular network constructed from the matrix resin component, the crosslinking enhancing component, and the flexible modifying component.
  2. 2. The stacked abrasive cloth with a chemically crosslinked network binder of claim 1, wherein the binder (312) with a chemically crosslinked network has a storage modulus decrease of less than an order of magnitude in the range of 30 degrees celsius to 250 degrees celsius, a loss factor tan delta maintained between 0.15 and 0.25 in the temperature range, a tensile strength of 60 mpa to 90 mpa at normal temperature, an elongation at break of 5% to 15%, and a glass transition temperature Tg of greater than 220 degrees celsius.
  3. 3. The stacked abrasive cloth with a chemically cross-linked network binder of claim 1, wherein isocyanate groups in the cross-linked reinforcing component react with hydroxyl groups on the molecular chains of the liquid phenolic resin to form urethane linkages forming a high thermal stability transverse scaffold in the chemically cross-linked network, and wherein the particles of nitrile rubber microspheres in the flexible modifying component are distributed between 0.2 microns and 0.8 microns as molecular dampers for dissipating grinding impact energy and preventing propagation of microcracks within the binder (312).
  4. 4. A stacked abrasive cloth with a chemically cross-linked network binder as claimed in claim 1, wherein said functional filler component comprises a reactive grinding aid and a physical anchoring filler; the active grinding aid is at least two selected from cryolite, potassium fluoborate and antimony sulfide, and forms a lubricating liquid film and inhibits thermal oxidation of a metal workpiece through melt decomposition at a high grinding temperature; the physical anchoring filler is nanoscale aluminum oxide powder with particle size distribution between 50 nanometers and 200 nanometers, the surface of the nanoscale aluminum oxide powder is subjected to silanization modification, and the cohesive strength of the binding agent (312) is improved through a nanoscale effect; The functional filler component also comprises a trace amount of foaming agent or hollow microspheres, so that a closed pore structure which is uniformly distributed is formed inside the stacked abrasive clusters (31), and the volume porosity of the functional filler component is controlled to be 3-10%.
  5. 5. A stacked abrasive cloth with a chemically cross-linked network binder according to claim 1, characterized in that the abrasive particles (311) are selected from ceramic corundum, monocrystalline corundum or microcrystalline corundum, and their surface is plasma activated to generate reactive radicals and grafted with a polymer film containing reactive groups on the activated surface, said polymer film forming covalent bonds with the cross-linking enhancing component of the binder (312) with a chemically cross-linked network, forming a chemical interface layer between the abrasive particles (311) and the binder (312).
  6. 6. A stacked abrasive cloth with a chemical cross-linked network binder according to claim 1, characterized in that the geometry of the stacked abrasive clusters (31) is cylindrical, hexagonal, hemispherical or long prismatic, the height of each stacked abrasive cluster (31) is 0.5 mm to 3.0 mm, the stacked abrasive clusters (31) are distributed in an asymmetric array on the flexible substrate layer (1) with a distribution density of 20 to 100 per square centimeter and a surface coverage of 40 to 80%, and the chemical cross-linked segments inside the stacked abrasive clusters (31) are grown in a direction perpendicular to the surface of the flexible substrate layer (1) under the induction of an external electric or magnetic field.
  7. 7. The stacked abrasive cloth with chemical cross-linked network binder according to claim 1, wherein the flexible substrate layer (1) is a desized, heat-set and impregnated polyester cloth or cotton fiber interwoven cloth with a mass per unit area of 300-600 grams per square meter and a dimensional shrinkage of less than 0.5% in an environment of 150-200 ℃; The primer bonding layer (2) is composed of modified phenolic resin, an aminosilane coupling agent and inorganic micro powder filler, wherein one end of the aminosilane coupling agent is combined with hydroxyl on the surface of the flexible substrate layer (1) through condensation reaction, and the other end of the aminosilane coupling agent participates in crosslinking reaction of a bonding agent in the chemical crosslinking stacked abrasive layer (3) through amino.
  8. 8. The stacked abrasive cloth with the chemical cross-linked network binder according to claim 1, wherein the reinforced paint coating layer (4) contains fluoride wear-resistant filler and antistatic agent, and the antistatic agent consists of a cationic surfactant with a long chain structure and conductive graphene nano sheets, so that the volume resistivity of the surface of the abrasive cloth is not higher than 10-6 ohm-cm; the reinforced paint coating layer (4) is filled in gaps among the stacked abrasive clusters (31) and the middle lower part of the cluster body, and the top ends of the stacked abrasive clusters (31) are kept exposed to form a top-exposed structure; The back of the flexible substrate layer (1) is also provided with an anti-slip coating (5), and the anti-slip coating (5) is formed by mixing a thermoplastic elastomer and corundum powder with the particle size of 40 microns.
  9. 9. The stacked abrasive cloth with chemically cross-linked network bond of claim 1, wherein the bond with chemically cross-linked network (312) further comprises: A thermally activated catalyst that remains chemically inert below 80 degrees celsius, activated in the range of 120 degrees celsius to 160 degrees celsius to induce the formation of a three-dimensional interpenetrating polymer network; a rheology control agent having a molecular recognition function that imparts thixotropic properties to the binder in a resting state through intermolecular hydrogen bonding association; And the metal complexing agent is fixed on the chemical crosslinking network branched chain and contains phosphonic acid groups, and is used for carrying out a complexing reaction with the fresh surface of the metal workpiece in the grinding process to generate a chemical conversion film.
  10. 10. The stacked abrasive cloth with chemically crosslinked network bond of claim 1, wherein the bond with chemically crosslinked network (312) has at least one of the following smart response characteristics: the self-repairing characteristic is that a reversible dynamic covalent bond in the form of disulfide bond or boric acid ester bond is introduced into the chemical crosslinking network and is used for repairing microcracks in the bonding agent under the triggering of grinding heat; thermochromic indicating characteristics, wherein microcapsules encapsulating the thermochromic indicator are dispersed in the binding agent (312) and are used for providing state monitoring feedback through color transition when the grinding temperature exceeds a preset limit value; Graded modulus response characteristics the chemical cross-linked network maintains a high modulus through covalent bonds during small deformation phases and provides compliance through elastic dissociation of non-covalent bonds during large deformation phases.

Description

Stacked abrasive cloth with chemical crosslinking network binder Technical Field The invention belongs to the field of manufacturing of coated abrasive tools, and particularly relates to stacked abrasive cloth with a chemical cross-linked network binder. Background In the field of modern precision machining and metal surface treatment, a coated grinding tool is used as a core tool for improving the surface integrity and machining precision of a workpiece, and the technical evolution of the coated grinding tool is always developed around three dimensions of grinding efficiency, service life and machining consistency. With the increasingly stringent requirements of industries such as aerospace, automobile manufacturing, precision die and the like on material removal rate and surface roughness control, the traditional single-layer coated abrasive cloth has the defects of extremely rapid abrasion, insufficient durability, obvious performance attenuation in the later processing stage and the like when dealing with continuous grinding operation with high strength and long time. To overcome these drawbacks, stacked abrasive technology has evolved and has gradually become the focus of research in the field of high performance abrasive cloths. Stacked abrasives are prepared by pre-granulating a plurality of fine abrasive particles with a binder to form abrasive clusters having a geometry and size, and coating the abrasive clusters onto the surface of a cloth substrate. The structural design enables the abrasive cloth to be exposed in time and participate in grinding after surface abrasive particles are dull or fall off in the cutting process through a mechanism of multilayer distribution and layer-by-layer exposure in the principle level, so that the service life of the tool is greatly prolonged, and the self-sharpening property and the stability of the processing effect in the grinding process are maintained. In the existing process for preparing the stacked abrasive cloth, the selection and performance of the binding agent are key factors for determining the structural strength and dynamic grinding behavior of the stacked abrasive clusters. The mainstream prior art generally adopts thermosetting resins such as phenolic resin, epoxy resin or urea resin as basic binders, and enhances the hardness and wear resistance thereof by adding various inorganic fillers. Under certain application scenarios, these binders are able to effectively consolidate the fine abrasive particles into a block and maintain the integrity of the stacked structure during the initial grinding stage by virtue of their high mechanical strength and good process processability. However, with the development of industrial processing technology towards high speed, heavy load and dry grinding, the prior art solutions gradually show a difficult-to-ignore inherent contradiction on the deep technical principle level. Specifically, the traditional resin bonding agent tends to form a relatively single molecular chain structure after curing, and the mechanical properties of the traditional resin bonding agent mainly depend on the physical properties of the resin matrix. In the high-speed grinding process, the abrasive particles and the surface of the workpiece are subjected to intense friction to generate instantaneous high temperature, and the heat load is far higher than the thermal deformation temperature of common resin. Although the addition of fillers can improve the transient heat resistance of the material, it does not materially alter the thermodynamic stability of the binder molecular layer. Further, it has been found that existing bond systems have a negative correlation contradiction between hardness and toughness that is not reconcilable when dealing with dynamic grinding shocks. To ensure that the bulk abrasive does not undergo global crushing spalling under heavy loads, it is generally necessary to increase the degree of crosslinking of the bond to increase its rigidity, but this inevitably leads to an increase in brittleness of the bond. In practical conditions, when the stacked abrasive is subjected to discontinuous mechanical impact, the highly brittle bonding agent is extremely prone to generating microscopic cracks in abrasive clusters, and the cracks can rapidly expand along the interface between abrasive particles and a matrix, so that abrasive particles fall off in a lump before being sufficiently dull, serious waste of abrasive resources is caused, and the due long-life advantage of the stacked abrasive is weakened. Meanwhile, if the crosslinking density is reduced for the purpose of pursuing toughness, the bonding agent is extremely easy to generate viscous flow or thermal degradation under the action of grinding heat, so that the abrasive clusters are seriously collapsed, the self-sharpening function is lost, the bonding agent is softened and adhered to the surface of a workpiece, and the surface quality after processing is serious