LAY FLAT COATED ABRASIVE DISCS

FIELD OF THE INVENTION

The present invention relates generally to coated abrasive articles that lay flat, such as coated abrasive discs, as well as methods of making and using said coated abrasive articles.

BACKGROUND

Abrasive articles, such as coated abrasives, are used in various industries to machine work pieces, such as by lapping, grinding, and polishing. Surface processing using abrasive articles spans a wide industrial scope from initial coarse material removal to high precision finishing and polishing of surfaces at a submicron level.

Effective and efficient abrasion of high performance metal, ceramic, and cermet industrial parts, such as drill bit components and aircraft engine parts, pose numerous processing challenges.

Industries that produce such parts are sensitive to factors that influence operational costs, including the speed at which a surface can be prepared, the cost of the materials used to prepare that surface, and the costs associated with the time expended to prepare a surface.

Therefore, there continues to be a demand for improved abrasive products and methods that can offer enhanced abrasive processing performance, efficiency, and improved surface quality.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG. 1 is an illustration of an embodiment of a coated abrasive article (a coated abrasive disc) that lays flat.

FIG. 2 is an illustration of a cross sectional view of the coated abrasive article embodiment of FIG. 1 and shows an abrasive layer disposed directly in contact with a layer of polymeric polyethylene composition.

FIG. 3 is a flowchart of an embodiment of a method of making a coated abrasive article that lays flat.

FIG. 4 is an illustration of an abrasive disc embodiment laying flat.

FIG. 5 is an illustration of another abrasive disc embodiment laying flat.

FIG. 6 is a photograph comparing the curvature of a sample abrasive disc embodiment 604 and a conventional abrasive disc 602 where the abrasive side of both abrasive discs faces upward.

FIG. 7 is a photograph comparing the curvature of a sample abrasive disc embodiment 704 and a conventional abrasive disc 702 where the backing side of both abrasive discs faces upward.

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION

The following description, in combination with the figures, is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This discussion is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings.

The term “averaged,” when referring to a value, is intended to mean an average, a geometric mean, or a median value. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but can include other features not expressly listed or inherent to such process, method, article, or apparatus. As used herein, the phrase “consists essentially of” or “consisting essentially of” means that the subject that the phrase describes does not include any other components that substantially affect the property of the subject.

Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

The use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

Further, references to values stated in ranges include each and every value within that range. When the terms “about” or “approximately” precede a numerical value, such as when describing a numerical range, it is intended that the exact numerical value is also included. For example, a numerical range beginning at “about 25” is intended to also include a range that begins at exactly 25. Moreover, it will be appreciated that references to values stated as “at least about,” “greater than,” “less than,” or “not greater than” can include a range of any minimum or maximum value noted therein.

As used herein, the phrase “average particle diameter” can be reference to an average, mean, or median particle diameter, also commonly referred to in the art as D50.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and can be found in textbooks and other sources within the coated abrasive arts.

COATED ABRASIVE ARTICLE

FIG. 1 shows an illustration of a cross section of an embodiment of a coated abrasive article 100. As shown in FIG. 1, the coated abrasive article can include an abrasive layer 103 disposed on a backing material 101 (also called herein a “backing”). The backing material 101 can comprise a backing substrate 105 having a first major surface 109 and a second major surface 107, wherein a layer of a polymeric front coat composition 111 (also called herein a “front coat”) is disposed on the first major surface 109 of the backing substrate, and wherein a layer of polymeric back coat composition 113 (also called herein a “back coat”) is disposed on the second major surface 107 of the backing substrate. The abrasive layer can include a plurality of abrasive particles 117 dispersed on or in a layer of polymeric binder composition 115 (also called herein a “make coat”). The layer of polymeric binder composition 115 can be disposed in direct contact with the polymeric front coat composition 111. A layer of polymeric size coat composition 119 (also called herein a “size coat”) can be disposed over the polymeric binder composition 115 and abrasive particles 117. Further, an optional layer of polymeric supersize coat composition (not shown) can be disposed over the size coat composition 119. In a particular embodiment, the coated abrasive article 100 may further include a tool attachment layer (not shown) located opposite the abrasive layer and disposed in contact with the polymeric back coat composition 113.

FIG. 2 shows an illustration of a coated abrasive article 200 embodiment. As shown in FIG. 2, the coated abrasive article 200 can include a body 201 that, in a particular embodiment, can be generally disc shaped. Abrasive particles 203 can be disposed on the working surface (also called herein the “abrasive surface” or “top surface”) of the abrasive article. In such an abrasive disc embodiment, the coated abrasive article 200 can be configured to be removably engaged with a power sanding tool (not depicted) such as a random orbit sander or other type of powered disc sander.

FIG. 3 is an illustration of a flowchart of an embodiment of a method 300 of making a coated abrasive article having curl resistance and that lays flat. Step 302 includes disposing a layer of a polymeric front coat composition (also called herein a “front coat”) on a first major surface of a backing substrate. Step 304 includes disposing a layer of a polymeric back coat composition (also called herein a “back coat”) on a second major surface of the backing substrate. In an embodiment, step 302 and step 304 can be accomplished at the same time. In another embodiment, step 302 and step 304 can be accomplished separately. Step 306 includes disposing a layer of a polymeric make coat composition (also called herein a “make coat”) on the front coat. Step 308 includes disposing a plurality of abrasive particles on or in the make coat. Step 310 includes disposing a polymeric size coat composition (also called herein a “size coat”) over the abrasive particles and the make coat to form an abrasive article. The abrasive article can be used as a polishing film, a polishing belt, or converted (i.e., cut) into different shapes, such as discs, sheets, or other shapes. Step 312 includes cutting the abrasive article into a plurality of abrasive discs. Optionally, a tool attachment layer can be disposed on the back coat.

FIG. 4 is an illustration of an abrasive disc embodiment laying flat. As used herein, the term “laying flat” means that when an abrasive disc is placed at rest on a flat surface that the disc has a curvature where the height (h) of the disc (i.e., the highest point of the disc) is less than or equal to 10% of the diameter of the disc. For instance, if a disc has a diameter (D) of 5 inches, the disc will be considered to lay flat if the height of the disc is equal to 0.5 inches or less. As shown in FIG. 4, the curvature of the disc is such that the height of the center of the disc is elevated, but is less than 10% of the diameter of the disc.

FIG. 5 is an illustration of another abrasive disc embodiment laying flat. As shown in FIG. 5, the curvature of the disc is such that the highest point(s) (i.e., the height) of the disc is located at the elevated edge(s) of the disc, but is less than 10% of the diameter of the disc.

FIG. 6 is a photograph showing an oblique downward view comparing the curvature of a sample abrasive disc embodiment 604 and a conventional abrasive disc 602. The abrasive surface of each abrasive disc faces upward away from the flat surface upon which the abrasive disc rests. The sample abrasive disc 604 lays flat and has a curvature where the height of the disc is less than 10% of the diameter of the disc. The comparative abrasive disc 602 does not lay flat.

FIG. 7 is a photograph showing an oblique downward view comparing the curvature of a sample abrasive disc embodiment 704 and a conventional abrasive disc 702. The back surface (non abrasive surface) of each abrasive disc faces upward away from the flat surface upon which the abrasive disc rests. The sample abrasive disc 704 lays flat and has a curvature where the height of the disc is less than 10% of the diameter of the disc. The comparative abrasive disc 702 does not lay flat.

BACKING MATERIAL

As previously stated, the backing material 101 (“backing”) comprises a backing substrate 105 having a first major surface 109 (“first side”) and a second major surface 107 (“second side”), wherein a layer of a polymeric front coat composition 111 (also called herein a “front coat”) is disposed on the first major surface 109 of the backing substrate, and wherein a layer of polymeric back coat composition 113 (also called herein a “back coat”) is disposed on the second major surface 107 of the backing substrate. In an embodiment, the backing material 101 can be beneficially flexible but also is resistant to curling and lays flat when at rest. The backing material 101 can comprise a proper combination of desired physical, chemical, mechanical, and/or performance properties and/or features to produce advantageous abrasive performance in combination with abrasive particles as described in greater detail herein.

BACKING SUBSTRATE

The backing substrate can comprise a polymeric film, such as polyolefin film (e.g., polypropylene including biaxially oriented polypropylene), a polyester film (e.g., polyethylene terephthalate), a polyamide film, or a cellulose ester film; a metal foil; a mesh; a foam (e.g., natural sponge material or polyurethane foam); a cloth (e.g., cloth made from fibers or yarns comprising polyester, nylon, silk, cotton, poly-cotton, rayon, or combinations thereof); a paper; a vulcanized paper; a vulcanized rubber; a vulcanized fiber; a nonwoven material; a combination thereof. In an embodiment, the polymeric film can be a surface energy modified film, such as a primed film, a corona treated film, a plasma treated film, a chemically treated film, or a combination thereof. In a specific example, the backing substrate can comprise a polyester film that has been chemically primed and corona treated or plasma treated. Suitable chemical primers can include imide type primers, such as polyethylene imine, and the like.

The backing substrate can have a surface energy in a beneficial range. In an embodiment, the surface energy of the film can be not less than 5 dyne, such as at least 10 dyne, at least 20 dyne, at least 30 dyne, at least 40 dyne, at least 45 dyne or at least 50 dyne. In an embodiment, the surface energy can be not greater than 100 dyne, such as not greater than 90 dyne, not greater than 80 dyne, not greater than 70 dyne, not greater than 65 dyne, or not greater than 60 dyne. The amount of surface energy can be within a range comprising any pair of the previous upper and lower limits. In an embodiment, the polymeric film can have an amount of surface energy not less than 5 dyne to not greater than 100 dyne, such as 20 dyne to 90 dyne, such as 30 dyne to 80 dyne, such as 40 dyne to 70 dyne, or 50 dyne to 60 dyne.

The backing substrate can have a thickness in a beneficial range. In an embodiment, the thickness of the film can be not less than 1 mil, such as at least 2 mil, at least 2.5 mil, at least 3 mil, at least 3.5 mil, at least 4 mil, or at least 4.5 mil. In an embodiment, the thickness can be not greater than 9 mil, such as not greater than 8 mil, not greater than 7.5 mil, not greater than 7 mil, not greater than 6.5 mil, or not greater than 6 mil. The amount of thickness can be within a range comprising any pair of the previous upper and lower limits. In an embodiment, the polymeric film can have an amount of thickness not less than 1 mil to not greater than 9 mil, such as 2 mil to 8 mil, such as 2.5 mil to 7.5 mil, such as 3 mil to 7 mil, or 50 mil to 60 mil.

FRONT COAT

In an embodiment, a layer of a polymeric front coat composition 111 (a “front coat”) is disposed on the first major surface 109 of the backing substrate. In an embodiment, the polymeric front coat composition can comprise a polyethylene composition. The polyethylene composition can comprise a low density polyethylene (LDPE), a linear low-density polyethylene (LLDPE), a high-density polyethylene (HDPE), a medium-density polyethylene (MDPE), or an ultra-high-molecular-weight polyethylene (UHMWPE). In a specific embodiment, the polymeric front coat composition comprises a low density polyethylene.

BACK COAT

In an embodiment, a layer of polymeric back coat composition 113 (a “back coat”) is disposed on the second major surface 107 of the backing substrate. In an embodiment, the polymeric back coat composition can comprise an acrylate composition. The acrylate composition can comprise an ethyl acrylate, an ethylene acrylate, an ethylene-ethyl acrylate (EEA), a methyl acrylate, an ethylene methyl acrylate (EMA) copolymer, a butyl acrylate, a copolymer of ethylene and butyl acrylate (EBA), an ethylene acrylic ester terpolymer (i.e., a terpolymer of ethylene, acrylic ester, and maleic anhydride), or a combination thereof. In a specific embodiment, the back coat composition comprises a mixture of 1) a copolymer of ethylene and butyl acrylate (EBA), and 2) an ethylene acrylic ester terpolymer (i.e., a terpolymer of ethylene, acrylic ester, and maleic anhydride).

ABRASIVE LAYER

In an embodiment, the abrasive layer can include a plurality of abrasive particles 117 dispersed on or in a layer of polymeric binder 115 (“make coat”). In an embodiment, the abrasive particles can be blended together with the polymeric binder to form an abrasive slurry wherein the abrasive particles are dispersed throughout the binder formulation. Alternatively, the polymeric binder composition can be coated onto the backing material and the abrasive particles then applied over the binder composition. Optionally, patterns can be formed in the abrasive layer by molding, pressing, or tooling of the abrasive layer.

ABRASIVE PARTICLES

Abrasive particles can include alumina, silicon carbide, silica, ceria, and harder, high performance superabrasive particles such as cubic boron nitride and diamond. The abrasive particles can be essentially single phase inorganic materials, mixed phase materials, or combinations thereof. Additionally, the abrasive particles can include composite particulate materials, such as aggregates, which can be formed through slurry processing pathways that include removal of the liquid carrier through volatilization or evaporation, leaving behind unfired (“green”) aggregates, that can optionally undergo high temperature treatment (i.e., firing, sintering) to form usable, fired aggregates. Further, the abrasive layer can include engineered abrasives including macrostructures and particular three-dimensional structures.

The abrasive particles can be formed of any one of or a combination of abrasive particles, including silica, alumina (ceramic, fused, or sintered), zirconia, zirconia/alumina oxides, silicon carbide, garnet, diamond, cubic boron nitride, silicon nitride, ceria, titanium dioxide, titanium diboride, boron carbide, tin oxide, tungsten carbide, titanium carbide, iron oxide, chromia, flint, emery. For example, the abrasive particles can be selected from a group consisting of silica, alumina, zirconia, silicon carbide, silicon nitride, boron nitride, garnet, diamond, co-fused alumina zirconia, ceria, titanium diboride, boron carbide, flint, emery, alumina nitride, and a blend thereof. Particular embodiments have been created by use of abrasive particles comprised of diamond.

In an embodiment, the abrasive particles can be diamond particles (also referred to herein as “diamonds”), cubic boron nitride particles, or combinations thereof. In an embodiment, the abrasive particles comprise diamonds. The diamonds can be monocrystalline, polycrystalline, or a combination thereof. The diamonds can be natural diamonds, synthetic diamonds, metal coated diamonds, resin coated diamonds, or combinations thereof. The abrasive particles can be loose diamonds, diamond agglomerates, diamond aggregates, or a combination thereof.

In specific embodiments, superabrasive particles include cubic boron nitride and diamond particles. These superabrasive particles can be natural (e.g. natural diamond) or synthetic (e.g. cubic boron nitride and synthetic diamond) products. The superabrasive particles may have a blocky shape associated with them or alternatively, a needle-like shape. The superabrasive particles may be surface coated or not surface coated. In an embodiment, a blend of superabrasive particles and conventional abrasive particles (e.g. alumina, silicon carbide, ceria, and silica) can be used.

The abrasive particles can have a particular shape, such as a rod, a triangle, a pyramid, a cone, a solid sphere, a hollow sphere, or the like. Alternatively, the abrasive particles can be randomly shaped.

The abrasive particles can be in a beneficial size range, conform to a beneficial size distribution, or a combination thereof. In an embodiment, the abrasive particles can have an average particle size of not less than 1 micron, such as at least 2 micron, at least 3 micron, at least 5 micron, at least 10 micron, at least 15 micron, at least 20 micron, or at least 25 micron. In an embodiment, the average particle size can be not greater than 500 micron, such as not greater than 400 micron, not greater than 300 micron, not greater than 200 micron, not greater than 150 micron, or not greater than 125 micron. The average particle size can be within a range comprising any pair of the previous upper and lower limits. In an embodiment, the abrasive particles can have an average particle size not less than 5 micron to not greater than 250 micron, such as 10 micron to 200 micron, such as 15 micron to 150 micron, such as 20 micron to 125 micron.

BINDER COMPOSITION—MAKE COAT OR SLURRY COAT

As stated previously, a layer of polymeric binder composition 115 can be disposed in direct contact with the polymeric front coat composition 111. In a particular aspect, the polymeric binder composition 115 can be comprised of a single polymer or a blend of polymers.

The binder composition can be formed from an epoxy composition, an acrylic composition, a phenolic composition, a polyurethane composition, a urea formaldehyde composition, a polysiloxane composition, or combinations thereof. In addition, the binder composition can include active filler particles, additives, or a combination thereof, as described herein.

The binder composition generally includes a polymer matrix, which binds abrasive particles to the backing or to a compliant coat, if such a compliant coat is present. Typically, the binder composition is formed of cured binder composition. In an embodiment, the binder composition includes a polymer component and a dispersed phase.

The binder composition can include one or more reaction constituents or polymer constituents for the preparation of a polymer. A polymer constituent can include a monomeric molecule, a polymeric molecule, or a combination thereof. The binder composition can further comprise components selected from the group consisting of solvents, plasticizers, chain transfer agents, catalysts, stabilizers, dispersants, curing agents, reaction mediators and agents for influencing the fluidity of the dispersion.

The polymer constituents can form thermoplastics or thermosets. By way of example, the polymer constituents can include monomers and resins for the formation of polyurethane, polyurea, polymerized epoxy, polyester, polyimide, polysiloxanes (silicones), polymerized alkyd, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polybutadiene, or, in general, reactive resins for the production of thermoset polymers. Another example includes an acrylate or a methacrylate polymer constituent. The precursor polymer constituents are typically curable organic material (i.e., a polymer monomer or material capable of polymerizing or crosslinking upon exposure to heat or other sources of energy, such as electron beam, ultraviolet light, visible light, etc., or with time upon the addition of a chemical catalyst, moisture, or other agent which cause the polymer to cure or polymerize). A precursor polymer constituent example includes a reactive constituent for the formation of an amino polymer or an aminoplast polymer, such as alkylated urea-formaldehyde polymer, melamine-formaldehyde polymer, and alkylated benzoguanamine-formaldehyde polymer; acrylate polymer including acrylate and methacrylate polymer, alkyl acrylate, acrylated epoxy, acrylated urethane, acrylated polyester, acrylated polyether, vinyl ether, acrylated oil, or acrylated silicone; alkyd polymer such as urethane alkyd polymer; polyester polymer; reactive urethane polymer; phenolic polymer such as resole and novolac polymer; phenolic/latex polymer; epoxy polymer such as bisphenol epoxy polymer; isocyanate; isocyanurate; polysiloxane polymer including alkylalkoxysilane polymer; or reactive vinyl polymer. The binder composition can include a monomer, an oligomer, a polymer, or a combination thereof. In a particular embodiment, the binder composition includes monomers of at least two types of polymers that when cured can crosslink.

In an embodiment, the binder composition can include epoxy constituents and acrylic constituents that when cured form an epoxy/acrylic hybrid polymer. Alternatively, the binder composition can comprise a butyl acrylate polymer. In an embodiment, the binder composition can comprise a cycloaliphatic epoxy resin, a di-acrylate resin, or a combination thereof. In a specific embodiment, the binder composition can comprise a hydrogenated diphenylolpropane (DPP) epoxy resin, an oxetane resin (4-member cyclic ether), a bisphenol A Epoxy Diacrylate resin (diacrylate ester of a bisphenol A epoxy resin), a propoxylated neopentyl glycol diacrylate resin, or combinations thereof.

SIZE COAT LAYER

As described above, layer of polymeric size coat composition 119 (a “size coat”) can be disposed over the polymeric binder composition 115 and abrasive particles 117. The size coat composition 119 can be the same as or different from the polymeric binder composition 115 of the abrasive layer 103 (i.e., the size coat composition can be the same as or different than the make coat composition). The size coat composition can include one or more fillers, additives, or a combination thereof.

In a specific embodiment, the size coat composition 119 can comprise an epoxy resin, an acrylic resin, an acrylate resin, an epoxy acrylate resin, or a combination thereof. In an embodiment, the size coat composition can comprise a reinforcing additive, such as amorphous silica. In a specific embodiment, the size coat composition can comprise a cycloaliphatic epoxy resin, an epoxide, a diepoxide, a butanediol, a triacrylate, a hexaacrylate, a cyclohexylcarboxylate, or a combination thereof. In a specific embodiment, the size coat composition can comprise a silica reinforced cycloaliphatic epoxy resin, an aliphatic epoxidized butanediol, trimethylolpropane triacrylate (TMPTA), dipentaerythritol hexaacrylate (DPHA), (3,4-epoxycyclohexane) methyl 3,4-epoxycyclohexylcarboxylate, or a combination thereof.

In a specific embodiment, the size coat composition can include 5 wt % to 45 wt % of a reinforcing filler, such 10 wt % to 35 wt % of a reinforcing filler.

SUPERSIZE COAT COMPOSITION

As previously described, the coated abrasive article 100 can optionally comprise a layer of supersize coat composition (not shown) disposed on the size coat composition 119. The supersize coat composition can be the same as or different from the polymeric binder composition 115 of the abrasive layer 103 and can be same as or different than the size coat composition 119 disposed thereon. In another aspect, the supersize coat composition may comprise an anti-loading agent (such as a stearate, such as a metal stearate, such as zinc stearate or calcium stearate) or a grinding aid (such as cryolite, potassium borofluorate), or a combination thereof.

ADDITIVES

In a particular aspect, the front coat composition 111, the back coat composition 113, the binder composition 115, the size coat composition 119, or the supersize coat composition (not shown) can include one or more additives. Additives can be available in an amount of 0 wt % to 10 wt % of any polymer layer (i.e., make coat layer, size coat layer, or supersize layer). Suitable additives, for example, can include grinding aids, fibers, lubricants, wetting agents, thixotropic materials, surfactants, thickening agents, pigments, dyes, antistatic agents, coupling agents, plasticizers, suspending agents, pH modifiers, adhesion promoters, lubricants, bactericides, fungicides, flame retardants, degassing agents, anti-dusting agents, dual function materials, initiators, chain transfer agents, stabilizers, dispersants, reaction mediators, colorants, and defoamers. The amounts of these additive materials can be selected to provide the properties desired. These optional additives can be present in any part of the overall system of the coated abrasive product according to embodiments of the present disclosure. Suitable grinding aids can be inorganic based; such as halide salts, for example cryolite, wollastonite, and potassium fluoroborate; or organic based, such as sodium lauryl sulphate, or chlorinated waxes, such as polyvinyl chloride. In an embodiment, the grinding aid can be an environmentally sustainable material.

TOOL ATTACHMENT LAYER

The abrasive article can optionally include a tool attachment layer. In a particular embodiment, the coated abrasive article 100 includes a tool attachment layer (not shown) that can be used to removably engage the coated abrasive article 100 with a power tool, such as a rotary sander. The tool attachment layer can include an adhesive.

In another aspect, the tool attachment layer can include a mechanical fastener. For example, the mechanical fastener can include a hook fastener, a loop fastener, or a combination thereof that is configured to removably engage with a corresponding mechanical fastener on the tool on which the coated abrasive article 100 is intended to be disposed during abrasive operations.

EMBODIMENTS

Embodiment 1. A coated abrasive article comprising: an abrasive layer disposed on a backing material; wherein the backing material comprises: a backing substrate having a first side and a second side, and a layer of polymeric polyethylene composition disposed on the first side of the backing substrate; wherein the abrasive layer is disposed directly in contact with the polymeric polyethylene composition.

Embodiment 2. The coated abrasive article of embodiment 1, wherein the coated abrasive article lays flat.

Embodiment 3. The coated abrasive article of embodiment 1, wherein the coated abrasive article has a curvature of not greater than 10% of the diameter of the abrasive article.

Embodiment 4. The coated abrasive article of embodiment 1, wherein the abrasive layer comprises a make coat or a size coat having a Young's modulus (stiffness) of at least 150 kpsi, such as at least 200 kpsi, at least 250 kpsi, at least 300 kpsi, at least 350 kpsi, at least 400 kpsi, at least 450 kpsi, or at least 500 kpsi.

Embodiment 5. The coated abrasive article of embodiment 4, wherein the abrasive layer comprises a make coat or a size coat having a Young's modulus (stiffness) of not greater than 900 kpsi, such as not greater than 850 kpsi, not greater than 800 kpsi, not greater than 750 kpsi, not greater than 700 kpsi, not greater than 650 kpsi, or not greater than 600 kpsi.

Embodiment 6. The coated abrasive article of embodiment 1, wherein the polymeric polyethylene composition comprises low density polyethylene, high density polyethylene, or a combination thereof.

Embodiment 7. The coated abrasive article of embodiment 1, wherein the layer of polymeric polyethylene composition comprises a thickness of at least 0.25 mil to not greater than 0.5 mil, such as at least 1 mil to not greater than 3 mil, or at least 1.5 mil to not greater than 2.5 mil.

Embodiment 8. The coated abrasive article of embodiment 1, further comprising a layer of polymeric acrylate composition disposed on a second side of the backing substrate.

Embodiment 9. The coated abrasive article of embodiment 8, wherein the polymeric acrylate composition comprises ethyl acrylate, ethylene acrylate, ethylene-methyl acrylate, ethylene-ethyl acrylate, or a combination thereof.

Embodiment 10. The coated abrasive article of embodiment 8, wherein the layer of polymeric acrylate composition comprises a thickness of at least 0.1 mil to not greater than 3 mil, such as at least 0.25 mil to not greater than 2.5 mil, or at least 0.5 mil to not greater than 2 mil.

Embodiment 11. The coated abrasive article of embodiment 1, wherein the backing substrate comprises a polymeric film.

Embodiment 12. The coated abrasive article of embodiment 11, wherein the polymeric film comprises a polyester film.

Embodiment 13. The coated abrasive article of embodiment 11, wherein the polymeric film comprises polyethylene terephthalate.

Embodiment 14. The coated abrasive article of embodiment 11, wherein the polymeric film comprises a thickness of at least 1 mil to not greater than 10 mil, such as at least 2 mil to not greater than 8 mil, at least 3 mil to not greater than 7 mil, or at least 4 mil to not greater than 6 mil.

Embodiment 15. The coated abrasive article of embodiment 11, wherein the polymeric film comprises a surface energy of at least 40 dyne/cm², such as at least 45 dyne/cm².

Embodiment 16. The coated abrasive article of embodiment 15, wherein the polymeric film is corona treated.

Embodiment 17. The coated abrasive article of embodiment 1, wherein the abrasive layer comprises a polymeric make coat composition and abrasive particles disposed in the make coat composition.

Embodiment 18. The coated abrasive article of embodiment 17, wherein the make coat composition comprises an epoxy acrylate polymer, an epoxy methacrylate polymer, a butyl acrylate polymer, or a combination thereof.

Embodiment 19. The coated abrasive article of embodiment 17, wherein the make coat composition further comprises a filler.

Embodiment 20. The coated abrasive article of embodiment 17, wherein the abrasive layer further comprises a polymeric size coat composition disposed on the make coat composition and abrasive particles.

Embodiment 21. The coated abrasive article of embodiment 17, wherein the size coat composition comprises an epoxy acrylate polymer, an epoxy methacrylate polymer, a butyl acrylate polymer, or a combination thereof.

Embodiment 22. The coated abrasive article of embodiment 17, wherein the make coat composition further comprises a filler.

Embodiment 23. The coated abrasive article of embodiment 17, wherein the abrasive particles comprise diamond, cubic boron nitride, or a combination thereof.

Embodiment 24. The coated abrasive article of embodiment 23, wherein the abrasive particles comprise a grit size of 5 microns to 500 microns.

EXAMPLES
Example 1.—Sample Coated Abrasive Film Preparation

Sample coated abrasive film was prepared as described herein. In a first step, a backing material was prepared by applying a front coat and a back coat to a backing substrate. Details of the backing material are provided below in Table 1. The completed backing material was stored for later use.

TABLE 1

Backing Material

S1

Front Coat
Low density polyethylene

Backing
Polymer film¹, primed², and corona treated³

Substrate

Back Coat
Copolymer Blend

90-95 wt % ethylene and butyl acrylate copolymer

05-10 wt % ethylene acrylic ester terpolymer⁵

¹Chemically treated PET film, 5 mil thick

²Primer—polyethylene imine

³50-60 dyne/cm², both sides

⁴Lotryl, Arkema, Inc.

⁵Lotader, Arkema, Inc.

The prepared backing material was then used to make a sample coated abrasive film as described herein. A make coat was applied to the backing material wherein the make coat was disposed onto the front coat of the backing material. Abrasive particles were disposed on the make coat and a size coat was applied over the make coat and abrasive particles. Details of the make coat, abrasive particles, and size coat are provided below in Table 2. The completed coated abrasive film was stored as a jumbo roll for later use.

TABLE 2

Coated Abrasive Film

S1

Size Coat
UV curable copolymer blend

40-65 wt % epoxy resin 3⁹

10-20 wt % epoxy resin 4¹⁰

1-10 wt % acrylate resin 2¹¹

0-5 wt % acrylate resin 3¹²

0-5 wt % epoxy acrylate resin¹³

10-20 wt % filler¹⁴

Abrasive
Metal bond diamond, 65-75 micron

Particles

Make Coat
UV curable copolymer blend

55-75 wt % epoxy resin 1⁶

05-12 wt % epoxy resin 2⁷

10-20 wt % oxetane

1-08 wt % acrylate resin⁸

⁶Diphenylolpropane (DPP) resin—Eponex

⁷Bisphenol A Epoxy Diacrylate—Ebecryl

⁸Propoxylated neopentyl glycol diacrylate—Sartomer

⁹Silica reinforced cycloaliphatic epoxy resin (Nanopox)

¹⁰Aliphatic epoxidized butanediol (Erisyg)

¹¹Trimethylolpropane triacrylate (TMTPA)

¹²Dipentaerythritol hexaacrylate (DPHA)

¹³methyl 3,4-epoxycyclohexylcarboxylate

¹⁴Amorphous silica

Example 2.—Sample Lay Flat Abrasive Discs

Sample coated abrasive film discs were prepared as described herein. Sample coated abrasive polishing film as prepared above in Example 1 was obtained from the jumbo roll and converted (i.e., cut) into a plurality of discs to make sample coated abrasive polishing discs. Surprisingly, even thought the discs were obtained from material near the center of the jumbo roll, the discs did not exhibit any significant curling and laid flat compared to conventional coated abrasive polymer film discs (i.e., when the unused disc was resting on a flat surface, the height of the highest point of the disc was less than 10% of the diameter of the disc, such as even less than 5% of the diameter of the disc. As shown in FIG. 6, the curvature of the sample abrasive disc embodiment 604 (abrasive face up) demonstrated that the sample disc was able to lay “flat” as described herein. In contrast, the comparative conventional abrasive film disc 602 (abrasive face up) had an excessive curvature (excessive curl) and did not lay “flat.” Similarly, as shown in FIG. 7, the curvature of the sample abrasive disc embodiment 704 (backing side up) and a comparative conventional abrasive film disc 702 (backing side up) had an excessive curvature (excessive curl) and did not lay “flat.”

In the foregoing, reference to specific embodiments and the connections of certain components is illustrative. It will be appreciated that reference to components as being coupled or connected is intended to disclose either direct connection between said components or indirect connection through one or more intervening components as will be appreciated to carry out the methods as discussed herein. As such, the above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Moreover, not all of the activities described above in the general description or the examples are required, that a portion of a specific activity cannot be required, and that one or more further activities can be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

The disclosure is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. In addition, in the foregoing disclosure, certain features that are, for clarity, described herein in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, can also be provided separately or in any subcombination. Still, inventive subject matter can be directed to less than all features of any of the disclosed embodiments.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that can cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

LAY FLAT COATED ABRASIVE DISCS

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