EP0964772A1 - Abrasive article for providing a clear surface finish on glass - Google Patents

Abrasive article for providing a clear surface finish on glass

Info

Publication number
EP0964772A1
EP0964772A1 EP98903763A EP98903763A EP0964772A1 EP 0964772 A1 EP0964772 A1 EP 0964772A1 EP 98903763 A EP98903763 A EP 98903763A EP 98903763 A EP98903763 A EP 98903763A EP 0964772 A1 EP0964772 A1 EP 0964772A1
Authority
EP
European Patent Office
Prior art keywords
abrasive
glass
abrasive article
article
backing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98903763A
Other languages
German (de)
English (en)
French (fr)
Inventor
Todd J. Christianson
David D. Nguyen
Robert G. Visser
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US08/813,228 external-priority patent/US5888119A/en
Priority claimed from US08/813,878 external-priority patent/US5910471A/en
Application filed by Minnesota Mining and Manufacturing Co filed Critical Minnesota Mining and Manufacturing Co
Publication of EP0964772A1 publication Critical patent/EP0964772A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B13/00—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor
    • B24B13/01—Specific tools, e.g. bowl-like; Production, dressing or fastening of these tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D11/00—Constructional features of flexible abrasive materials; Special features in the manufacture of such materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
    • B24D3/28—Resins or natural or synthetic macromolecular compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D2203/00—Tool surfaces formed with a pattern

Definitions

  • the polishing time interval of the grinder/polisher is set at 15 seconds or 10 seconds.
  • real time contact between the abrasive article and the glass test blank surface may be greater than the set time because the grinder/polisher will not begin timing until the abrasive article is stabilized on the glass test blank surface. That is, there may be some bouncing or skipping of the abrasive article on the glass surface and the grinder/polisher begins timing at the point when contact between the abrasive article and the glass surface is substantially constant.
  • real time polish interval i.e. the contact between the abrasive article and the glass surface, is about 25 seconds or less.
  • the actual time (rate) necessary to polish a glass workpiece to an Ra value will vary depending upon a number of factors, such as the polishing apparatus used, the backing pad under the abrasive article, the speed of the abrasive rotation, the size of the surface area to be polished, the contact pressure, the abrasive particle size, the initial condition of the surface to be polished, etc.
  • Each of the RPP procedures above simply provide a baseline performance characteristic that can be used to compare the article and the method according to the invention with conventional glass polishing techniques.
  • the method includes contacting the glass workpiece having an initial Ra of about 0.2 ⁇ m or greater with an abrasive article capable of removing about 0.2 g of glass stock from a glass test blank using an RPP procedure having a polish time interval of about 25 seconds, wherein the initial Ra is reduced to a final Ra of about 0.05 ⁇ m or less.
  • the abrasive article includes diamond particles dispersed within a binder. More preferably, the abrasive particles have an average size of about 30 ⁇ m to about 45 ⁇ m.
  • the method includes contacting the glass workpiece having an initial Ra of about 0.05 ⁇ m or greater with an abrasive article capable of removing about 0.02 g of glass stock from a glass test blank using an RPP procedure having a polish time interval of about 25 seconds, wherein the initial Ra is reduced to about 0.05 ⁇ m or less.
  • the abrasive article includes diamond particles dispersed within a binder. More preferably, the abrasive particles have an average size of about 9 ⁇ m to about 15 ⁇ m.
  • this combination of urethane acrylate oligomer or blend of urethane acrylate oligomer with an acrylate monomer and diamond abrasive particles provides an abrasive coating that is long lasting and durable. It is hypothesized that the abrasive particles and the binder chemistry provide a synergistic combination for improved glass polishing results by using an abrasive article according to the invention.
  • abrasive composites can be of any geometrical shape defined by a substantially distinct and discernible boundary, wherein the precise geometrical shape is selected from the group consisting of cubic, prismatic, conical, block-like truncated conical, pyramidal, truncated pyramidal, cylindrical, hemispherical and the like.
  • Optically clear surface refers to a surface that is essentially free of any defects, imperfections and/or minute scratches visible to the naked eye.
  • Figure 1 is a plan view of one preferred abrasive article in accordance with the invention.
  • Figure 2 is an enlarged cross section taken along the line 2-2 of the abrasive article illustrated in Figure 1.
  • the present invention pertains to an article and a method of refining (preferably polishing) a glass workpiece with an abrasive article that comprises a backing and at least one three-dimensional abrasive coating preferably comprising diamond particles dispersed within a binder bonded to a surface of the backing.
  • the abrasive coating comprises a binder formed from a binder precursor and a plurality of abrasive particles, preferably diamond abrasive particles.
  • the end use of the glass may be in a home or a commercial environment.
  • the glass may be used for decorative purposes or structural purposes.
  • the glass will have at least one surface that is to be polished.
  • the glass may be relatively flat or it may have some contour associated with it. These contours can be in the shape of curves or corners.
  • Examples of glass workpieces include optical components such as lenses, prisms, mirrors, CRT (cathode ray tube) screens and the like.
  • CRT screens are found extensively in display surfaces used in devices such as television sets, computer monitors, computer terminals and the like.
  • CRT screens range in size (as measured along the diagonal) of about 10 cm (4 inches) to about 100 cm (40 inches) or more.
  • CRT screens have an outer surface that is convex and there is a radius of curvature. During polishing, the abrasive article of the invention will polish this CRT screen.
  • A. Binders are found extensively in display surfaces used in devices such as television sets, computer monitors,
  • the binder is formed from a binder precursor.
  • the binder precursor comprises a resin that is in an uncured or unpolymerized state. During the manufacture of the abrasive article, the resin in the binder precursor is polymerized or cured, such that a binder is formed.
  • the binder precursor can comprise a condensation curable resin, an addition polymerizable resin, a free radical curable resin and/or combinations and blends thereof.
  • the preferred binder precursors are resins that polymerize via a free radical mechanism.
  • the polymerization process is initiated by exposing the binder precursor, along with an appropriate catalyst, to an energy source such as thermal energy or radiation energy.
  • an energy source such as thermal energy or radiation energy.
  • radiation energy include electron beam, ultraviolet light or visible light.
  • This binder chemistry is especially efficacious when used with diamond abrasive particles because diamond abrasive particles last substantially longer than most conventional abrasive particles.
  • a tough and durable binder is desired.
  • this combination of urethane acrylate oligomer or blend of urethane acrylate oligomer with an acrylate monomer and diamond abrasive particles provides an abrasive coating that is long lasting and durable.
  • Acrylated urethanes are also acrylate esters of hydroxy terminated isocyanate extended polyesters or polyethers. They can be aliphatic or aromatic. Examples of commercially available acrylated urethanes include those known by the trade designations PHOTOMER (e.g., PHOTOMER 6010) from Henkel Corp.
  • EBECRYL 220 hexafunctional aromatic urethane acrylate of molecular weight 1000
  • EBECRYL 284 aliphatic urethane diacrylate of 1200 molecular weight diluted with 1 ,6-hexanediol diacrylate
  • EBECRYL 4827 aromatic urethane diacrylate of 1600 molecular weight
  • EBECRYL 4830 hexafunctional aromatic urethane acrylate of molecular weight 1000
  • EBECRYL 284 aliphatic urethane diacrylate of 1200 molecular weight diluted with 1 ,6-hexanediol diacrylate
  • EBECRYL 4827 aromatic urethane diacrylate of 1600 molecular weight
  • EBECRYL 4830 aromatic urethane diacrylate of 1600 molecular weight
  • EBECRYL 6602 trifunctional aromatic urethane acrylate of 1300 molecular weight diluted with trimethylolpropane ethoxy triacrylate
  • EBECRYL 840 aliphatic urethane diacrylate of 1000 molecular weight
  • Smyrna, GA SARTOMER (e.g., SARTOMER 9635, 9645, 9655, 963-B80, 966-A80, etc.) from Sartomer Co., West Chester, PA, and UVITHANE (e.g., UVITHANE 782) from Morton International, Chicago, 111.
  • SARTOMER e.g., SARTOMER 9635, 9645, 9655, 963-B80, 966-A80, etc.
  • UVITHANE e.g., UVITHANE 782
  • the ethylenically unsaturated monomers or oligomers, or acrylate monomers or oligomers may be monofunctional, difunctional, trifunctional or tetrafunctional or even higher functionality.
  • the term acrylate includes both acrylates and methacrylates.
  • Ethylenically unsaturated binder precursors include both monomeric and polymeric compounds that contain atoms of carbon, hydrogen and oxygen, and optionally, nitrogen and the halogens. Oxygen or nitrogen atoms or both are generally present in ether, ester, urethane, amide, and urea groups.
  • Ethylenically unsaturated compounds preferably have a molecular weight of less than about 4,000 and are preferably esters made from the reaction of compounds containing aliphatic monohydroxy groups or aliphatic polyhydroxy groups and unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and the like.
  • ethylenically unsaturated monomers include methyl methacrylate, ethyl methacrylate, styrene, divinylbenzene, hydroxy ethyl acrylate, hydroxy ethyl methacrylate, hydroxy propyl acrylate, hydroxy propyl methacrylate, hydroxy butyl acrylate, hydroxy butyl methacrylate, vinyl toluene, ethylene glycol diacrylate, polyethylene glycol diacrylate, ethylene glycol dimethacrylate, hexanediol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, pentaerthyitol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate and pentaerythritol tetramethacrylate.
  • ethylenically unsaturated resins include monoallyl, polyallyl, and polymethallyl esters and amides of carboxylic acids, such as diallyl phthalate, diallyl adipate, and N,N-diallyladipamide.
  • Still other nitrogen containing compounds include tris(2- acryl-oxyethyl)isocyanurate, l,3,5-tri(2-methacryloxyethyl)-s-triazine, acrylamide, methylacrylamide, N-methyl-acrylamide, N,N-dimethylacrylamide, N-vinyl- pyrrolidone, and N-vinyl-piperidone, and CMD 3700, available from Radcure Specialties.
  • ethylenically unsaturated diluents or monomers can be found in U.S. Pat. Nos. 5,236,472 (Kirk et al.) and 5,580,647 (Larson et al.).
  • the weight ratio between these acrylate monomers depends upon the weight percent of diamond abrasive particles desired in the final abrasive article.
  • these acrylate monomers range from about 5 parts by weight to about 95 parts by weight urethane acrylate oligomer to about 5 parts by weight to about 95 parts by weight ethylenically unsaturated monomer.
  • these acrylate monomers range from about 30 parts by weight to about 70 parts by weight urethane acrylate oligomer to about 30 parts by weight to about 70 parts by weight ethylenically unsaturated monomer, more preferably from about 34 parts by weight to about 65 parts by weight urethane acrylate oligomer to about 46 parts by weight to about 54 parts by weight ethylenically unsaturated monomer and most preferably 50 parts by weight urethane acrylate oligomer to 50 parts by weight ethylenically unsaturated monomer. Additional info ⁇ nation concerning other potential useful binders and binder precursors can be found in assignee's co-pending Patent Application Ser. No.
  • Acrylated epoxies are diacrylate esters of epoxy resins, such as the diacrylate esters of bisphenol A epoxy resin.
  • Examples of commercially available acrylated epoxies include CMD 3500, CMD 3600, and CMD 3700, available from Radcure Specialties, and CN103, CN104, CN111, CN112 and CN114 commercially available from Sartomer, West Chester, PA.
  • polyester acrylates examples include Photomer 5007 and Photomer 5018 from Henkel Corporation, Hoboken, NJ.
  • the aminoplast resins have at least one pendant alpha, beta-unsaturated carbonyl group per molecule or oligomer.
  • These unsaturated carbonyl groups can be acrylate, methacrylate or acrylamide type groups. Examples of such materials include N-(hydroxymethyl)-acrylamide, N,N'-oxydimethylenebisacrylamide, ortho and para acrylamidomethylated phenol, acrylamidomethylated phenolic novolac and combinations thereof. These materials are further described in U.S. Pat. Nos. 4,903,440 (Larson et al.) and 5,236,472 (Kirk et al.).
  • the binder precursor may further comprise a curing agent, (which is also known as a catalyst or initiator).
  • a curing agent which is also known as a catalyst or initiator.
  • the binder precursor may comprise an epoxy resin.
  • Epoxy resins have an oxirane and are polymerized by the ring opening.
  • Such epoxide resins include monomeric epoxy resins and polymeric epoxy reins.
  • examples of some preferred epoxy resins include 2,2-bis[4-(2,3-epoxypropoxy)-phenyl)propane, a diglycidyl ether of bisphenol, commercially available materials under the trade designation EPON 828, EPON 1004 and EPON 100 IF available from Shell Chemical Co., and DER-331, DER-332 and DER-334 available from Dow Chemical Co.
  • epoxy resins include cycloaliphatic epoxies, glycidyl ethers of phenol formaldehyde novolac (e.g., DEN-431 and DEN-428 available from Dow Chemical Co.
  • DEN-431 and DEN-428 available from Dow Chemical Co.
  • the blend of free radical curable resins and epoxy resins are further described in U.S. Pat. Nos. 4,751,138 (Tumey et al.) and 5,256,170 (Harmer et al.). It may be preferred in some instances to form the abrasive article by use of make and size coatings.
  • a make coating is applied to a backing, the abrasive particles are applied to the backing, the make coating is exposed to conditions to at least partially cure the make coating, and a size coating is applied over the abrasive particles and make coating.
  • the structure is then subjected to conditions sufficient to cure the make and size coatings.
  • Optional presize and supersize coatings may also be applied as known in the art.
  • Backings serve the function of providing a support for the abrasive composite formed by the combination of binder and abrasive particles.
  • Backings useful in the invention must be capable of adhering to the binder after exposure of binder precursor to curing conditions, and are preferably flexible after said exposure so that the articles used in the inventive method may conform to surface contours, radii and irregularities in the glass.
  • the backing In many glass polishing applications, the backing needs to be strong and durable so that the resulting abrasive article is long lasting. Additionally, in some polishing applications the backing needs to be strong and flexible so that the abrasive article can conform uniformly to the glass workpiece. This is typically true, when the glass workpiece has a shape or contour associated with it.
  • the backing can be a polymeric film, paper, vulcanized fiber, a treated nonwoven backing or a treated cloth backing to provide these properties of strength and conformability. Examples of polymeric film include polyester film, co-polyester film, polyimide film, polyamide film and the like.
  • a nonwoven, including paper can be saturated with either a thermosetting or thermoplastic material to provide the necessary properties.
  • the cloth can be a J weight, X weight, Y weight or M weight cloth.
  • the fibers or yarns forming the cloth can be selected from the group consisting of: polyester, nylon, rayon, cotton, fiberglass and combinations thereof.
  • the cloth can be a knitted or woven cloth (e.g., drills, twills or sateen weaves) or it can be a stitchbonded or weft insertion cloth.
  • the greige cloth can be textured, singed, desized or any conventional treatment for a greige cloth. It is preferred to treat the cloth with polymeric material to seal the cloth and to protect the cloth fibers.
  • the treatment may involve one or more of the following treatments: a presize, a saturant or a backsize.
  • One such treatment involves a presize coating applied first, followed by a backsize coating. Alternatively, a saturant coating, followed by a backsize coating. It is generally preferred that the front surface of the backing be relatively smooth. Likewise, the treatment coat(s) should result in the cloth backing being waterproof, since glass polishing is typically done in the presence of water. Similarly, the treatment coat(s) should result in the cloth backing having sufficient strength and flexibility.
  • One preferred backing treatment is a crosslinked urethane acrylate oligomer blended with an acrylate monomer resin. It is within the scope of this invention that the cloth treatment chemistry is identical or is similar in nature to the chemistry of the binder. The cloth treatment chemistry may further comprise additives such as: fillers, dyes, pigments, wetting agents, coupling agents, plasticizers and the like.
  • thermosetting and thermoplastic resins examples include thermosetting and thermoplastic resins.
  • typical and preferred thermosetting resins include phenolic resins, aminoplast resins, urethane resins, epoxy resins, ethylenically unsaturated resins, acrylated isocyanurate resins, urea-formaldehyde resins, isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, bismaleimide resins and mixtures thereof.
  • preferred thermoplastic resins include polyamide resins (e.g. nylon), polyester resins and polyurethane resins (including polyurethane-urea resins).
  • One preferred thermoplastic resin is a polyurethane derived from the reaction product of a polyester polyol and an isocyanate.
  • the abrasive articles according to the invention also include a plurality of abrasive particles.
  • abrasive particles is meant to include single abrasive particles bonded together by a binder to form an abrasive agglomerate or composite. Abrasive agglomerates are further described in U.S. Pat. Nos. 4,311,489; 4,652,275 and 4,799,939.
  • the abrasive particle may further comprise a surface treatment or coating, such as a coupling agent or metal or ceramic coatings.
  • Abrasive particles useful in the invention preferably have an average particle size about 0.01 micrometer (small particles) to 300 micrometers (large particles), more preferably about 5 micrometers to about 150 micrometers, and most preferably about 9 micrometers to about 80 micrometers. It is preferred that the abrasive particles have a Mohs hardness of at least 8, more preferably at least 9. Examples of such abrasive particles include fused aluminum oxide, ceramic aluminum oxide, heated treated aluminum oxide, silicon carbide, alumina zirconia, iron oxide, diamond (natural and synthetic), ceria, cubic boron nitride, garnet and combinations thereof.
  • the abrasive article utilize diamond abrasive particles.
  • These diamond abrasive particles can be natural or synthetically made diamonds. Relative to synthetically made diamonds, the particles may be considered “resin bond diamonds", “saw blade grade diamonds” or “metal bond diamonds”.
  • the diamonds may have a blocky shape associated with them or alternatively, a needle like shape.
  • the diamond particles may contain a surface coating such as a metal coating (e.g., nickel, aluminum, copper or the like), an inorganic coating( e.g., silica) or an organic coating.
  • the abrasive article of the invention may contain a blend of diamond with other abrasive particles.
  • the three-dimensional abrasive coating can comprise by weight anywhere between about 0.1 part abrasive particles to 90 parts abrasive particles and 10 parts binder to 99.9 parts binder. However due to the expense associated with diamond abrasive particles, it is preferred that the abrasive coating comprise about 0.1 to 50 parts abrasive particles and about 50 to 99.9 parts binder. More preferably, the abrasive coating comprises about 1 to 30 parts abrasive particles and about 70 to 99 parts binder and most preferably, the abrasive coating comprises about 3 to 25 parts abrasive particles and about 75 to 97 parts binder. D.
  • the abrasive coating of this invention can further comprise optional additives, such as, abrasive particle surface modification additives, coupling agents, fillers, expanding agents, fibers, antistatic agents, curing agents, suspending agents, photosensitizers, lubricants, wetting agents, surfactants, pigments, dyes, UV stabilizers, and anti-oxidants.
  • optional additives such as, abrasive particle surface modification additives, coupling agents, fillers, expanding agents, fibers, antistatic agents, curing agents, suspending agents, photosensitizers, lubricants, wetting agents, surfactants, pigments, dyes, UV stabilizers, and anti-oxidants.
  • abrasive particle surface modification additives such as, abrasive particle surface modification additives, coupling agents, fillers, expanding agents, fibers, antistatic agents, curing agents, suspending agents, photosensitizers, lubricants, wetting agents, surfactants, pigments, dyes, UV stabilizer
  • a coupling agent can provide an association bridge between the binder and the abrasive particles. Additionally the coupling agent can provide an association bridge between the binder and the filler particles.
  • Examples of coupling agents include silanes, titanates, and zircoaluminates.
  • the coupling agent may be added directly to the binder precursor.
  • the abrasive coating may contain anywhere from about 0 to 30%, preferably between 0.1 to 25% by weight coupling agent.
  • the coupling agent may be applied to the surface of the filler particles. In yet another mode, the coupling agent is applied to the surface of the abrasive particles prior to being incorporated into the abrasive article.
  • the abrasive particle may contain anywhere from about 0 to 3% by weight coupling agent, based upon the weight of the abrasive particle and the coupling agent.
  • Examples of commercially available coupling agents include “A174" and “A1230” from OSI.
  • Still another example of a commercial coupling agent is an isopropyl triisosteroyl titanate commercially available from Kenrich Petrochemicals, Bayonne, NJ, under the trade designation "KR-TTS”.
  • the abrasive coating can further optionally comprise a filler.
  • a filler is a particulate material and generally has an average particle size range between 0.1 to 50 micrometers, typically between 1 to 30 micrometers.
  • Examples of useful fillers for this invention include: metal carbonates (such as calcium carbonate (chalk, calcite, marl, travertine, marble and limestone), calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silica (such as quartz, glass beads, glass bubbles and glass fibers) silicates (such as talc, clays, (montmorillonite) feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminosilicate, sodium silicate) metal sulfates (such as calcium sulfate, barium sulfate, sodium sulfate, aluminum sodium sulfate, aluminum sulfate), gypsum, vermiculite, wood flour, aluminum trihydrate, carbon black, metal oxides (such as calcium oxide (lime), aluminum oxide, tin oxide (e.g.
  • stannic oxide titanium dioxide
  • metal sulfites such as calcium sulfite
  • thermoplastic particles polycarbonate, polyetherimide, polyester, polyethylene, polysulfone, polystyrene, acrylonitrile-butadiene-styrene block copolymer, polypropylene, acetal polymers, polyurethanes, nylon particles
  • thermosetting particles such as phenolic bubbles, phenolic beads, polyurethane foam particles and the like.
  • the filler may also be a salt such as a halide salt.
  • halide salts include sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroboate, sodium tetrafluoroborate, silicon fluorides, potassium chloride, magnesium chloride.
  • metal fillers include, tin, lead, bismuth, cobalt, antimony, cadmium, iron titanium.
  • Other miscellaneous fillers include sulfur, organic sulfur compounds, graphite and metallic sulfides.
  • suspending agent is an amorphous silica particle having a surface area less than 150 meters square/gram that is commercially available from DeGussa Corp., Ridgefield Park, NJ, under the trade name "OX-50".
  • the addition of the suspending agent can lower the overall viscosity of the abrasive slurry.
  • the use of suspending agents is further described in U.S. Patent No. 5,368,619. Curing Agents
  • the binder precursor may further comprise a curing agent.
  • a curing agent is a material that helps to initiate and complete the polymerization or crosslinking process such that the binder precursor is converted into a binder.
  • the term curing agent encompasses initiators, photoinitiators, catalysts and activators. The amount and type of the curing agent will depend largely on the chemistry of the binder precursor.
  • Polymerization of the preferred ethylenically unsaturated monomer(s) or oligomer(s) occurs via a free-radical mechanism.
  • the energy source is an electron beam
  • the electron beam generates free-radicals which initiate polymerization.
  • the energy source is heat, ultraviolet light, or visible light, an initiator may have to be present in order to generate free-radicals.
  • initiators i.e., photoinitiators
  • examples of initiators include, but are not limited to, organic peroxides, azo compounds, quinones, nitroso compounds, acyl halides, hydrazones, mercapto compounds, pyrylium compounds, imidazoles, chlorotriazines, benzoin, benzoin alkyl ethers, diketones, phenones, and mixtures thereof.
  • An example of a commercially available photoinitiator that generates free radicals upon exposure to ultraviolet light include IRGACURE 651 and IRGACURE 184 commercially available from the Ciba Geigy Company, Hawthorne, NJ, and DAROCUR 1173 commercially available from Merck. Examples of initiators that generate free-radicals upon exposure to visible light can be found in U.S. Patent No. 4,735,632. Another photoinitiator that generates free- radicals upon exposure to visible light has the trade name IRGACURE 369, commercially available from Ciba Geigy Company.
  • the initiator is used in amounts ranging from 0.1 to 10%, preferably 2 to 4% by weight, based on the weight of the binder precursor. Additionally, it is preferred to disperse, preferably uniformly disperse, the initiator in the binder precursor prior to the addition of any particulate material, such as the abrasive particles and/or filler particles.
  • the binder precursor be exposed to radiation energy, preferably ultraviolet light or visible light.
  • radiation energy preferably ultraviolet light or visible light.
  • certain abrasive particles and/or certain additives will absorb ultraviolet and visible light, which makes it difficult to properly cure the binder precursor. This phenomena is especially true with ceria abrasive particles and silicon carbide abrasive particles.
  • phosphate containing photoinitiators in particular acylphosphine oxide containing photoinitiators, tend to overcome this problem.
  • An example of such a photoinitiator is 2,4,6- trimethylbenzoyldiphenylphosphine oxide which is commercially available from BASF Corporation, Charlotte, NC, under the trade designation LUCIRTN TPO.
  • the curable compositions may contain photosensitizers or photoinitiator systems which affect polymerization either in air or in an inert atmosphere, such as nitrogen.
  • photosensitizers or photoinitiator systems include compounds having carbonyl groups or tertiary amino groups and mixtures thereof.
  • the preferred compounds having carbonyl groups are benzophenone, acetophenone, benzil, benzaldehyde, o-chlorobenzaldehyde, xanthone, thioxanthone, 9,10-anthraquinone, and other aromatic ketones which can act as photosensitizers.
  • the preferred tertiary amines are methyldiethanolamine, ethyldiethanolamine, triethanolamine, phenylmethyl- ethanolamine, and dimethylaminoethylbenzoate.
  • the amount of photosensitizer or photoinitiator system may vary from about 0.01 to 10% by weight, more preferably from 0.25 to 4.0% by weight, based on the weight of the binder precursor.
  • photosensitizers include QUANTICURE ITX, QUANTICURE QTX, QUANTICURE PTX, QUANTICURE EPD, all commercially available from Biddle Sawyer Corp.
  • the abrasive article according to the invention comprises a backing having an abrasive coating bonded to the backing. It is preferred that the abrasive coating comprising a plurality of shaped abrasive composites. These abrasive composites can be precisely shaped or irregularly shaped. It is preferred that the abrasive composites be precisely shaped, because precisely shaped composites are more uniform and consistent.
  • the abrasive article 10 includes a backing 12 bearing on one major surface thereof abrasive composites 16.
  • the abrasive composites 16 include a plurality of abrasive particles 14 dispersed in a binder 15.
  • the abrasive particles 14 may be of a mixture of different abrasive materials.
  • the binder 15 may be used to bind the abrasive composites 16 to the backing 12.
  • a presize coating or tie layer 13 may optionally be interposed between the abrasive composites 16 and the backing 12.
  • the abrasive composite shape can be any shape. Typically the cross- sectional surface area of the base side of the shape that is in contact with the backing is larger in value than that of the distal end of the composite spaced from the backing.
  • the shape of the composite can be selected from among a number of geometric shapes such as a cubic, block-like, cylindrical, prismatic, rectangular, pyramidal, truncated pyramidal, conical, truncated conical, cross, post-like with a top surface which is flat. Another shape is hemispherical and this is further described in PCT WO 95/22436.
  • the resulting abrasive article can have a mixture of different abrasive composite shapes.
  • the hemispherical abrasive composites 16' may vary in size and shape and may be distributed randomly or uniformly on the presize coating 13'. Preferably, the hemispherical abrasive composites 16' appear circular from a plan view, Fig. 3, and have the same diameter.
  • the first step to make the abrasive article is to prepare the abrasive slurry.
  • the abrasive slurry is made by combining together by any suitable mixing technique the binder precursor, the abrasive particles and the optional additives. Examples of mixing techniques include low shear and high shear mixing, with high shear mixing being preferred. Ultrasonic energy may also be utilized in combination with the mixing step to lower the abrasive slurry viscosity.
  • the abrasive particles are gradually added into the binder precursor. It is preferred that the abrasive slurry be a homogeneous mixture of binder precursor, abrasive particles and optional additives. If necessary water and/or solvent can be added to lower the viscosity.
  • the amount of air bubbles in the abrasive slurry can be minimized by pulling a vacuum either during or after the mixing step.
  • This method generally results in an abrasive composite that has a precise shape.
  • the binder precursor is substantially solidified or cured while the abrasive slurry is present in cavities of a production tool.
  • the production tool is removed from the binder precursor prior to substantial curing, resulting in a slumped, somewhat irregularly shaped side walls.
  • the preferred method of producing the abrasive article comprising precisely-shaped abrasive composites uses a production tool containing a plurality of cavities. These cavities are essentially the inverse shape of the desired abrasive composites and are responsible for generating the shape of the abrasive composites.
  • the number of cavities/square unit area results in the abrasive article having a corresponding number of abrasive composites/square unit area.
  • These cavities can have any geometric shape such as a cylinder, dome, pyramid, rectangle, truncated pyramid, prism, cube, cone, truncated cone or any shape having a top surface cross-section being a triangle, square, circle, rectangle, hexagon, octagon, or the like.
  • the dimensions of the cavities are selected to achieve the desired number of abrasive composites/square unit area.
  • the cavities can be present in a dot like pattern with spaces between adjacent cavities or the cavities can butt up against one another.
  • the abrasive slurry can be coated into the cavities of the production tool by any conventional technique such as die coating, vacuum die coating, spraying, roll coating, transfer coating, knife coating and the like. If the production tool comprises cavities that either have either flat tops or relatively straight side walls, then it is preferred to use a vacuum during coating to minimize any air entrapment.
  • the production tool can be a belt, a sheet, a continuous sheet or web, a coating roll such as a rotogravure roll, a sleeve mounted on a coating roll, or die.
  • the production tool can be composed of metal, including a nickel-plated surface, metal alloys, ceramic, or plastic. Further information on production tools, their production, materials, etc. can be found in U.S. Patent Nos. 5,152,917 (Pieper et al.) and 5,435,816 (Spurgeon et al.).
  • One preferred production tool is a thermoplastic production tool that is embossed off of a metal master.
  • the binder precursor is cured or polymerized. This polymerization is generally initiated upon exposure to an energy source.
  • an energy source In general, the amount of energy depends upon several factors such as the binder precursor chemistry, the dimensions of the abrasive slurry, the amount and type of abrasive particles and the amount and type of the optional additives.
  • Radiation energy is the preferred energy source.
  • the radiation energy sources include electron beam, ultraviolet light, or visible light. Electron beam(ionizing)radiation can be used at an energy level of about 0.1 to about 10 Mrad, preferably at an energy level of about 0.1 to about 10 Mrad.
  • Ultraviolet radiation refers to non-particulate radiation having a wavelength within the range of about 200 to about 400 nanometers, preferably within the range of about 250 to 400 nanometers.
  • the preferred output of the radiation source is 118 to 236 Watt cm.
  • Visible radiation refers to non-particulate radiation having a wavelength within the range of about 400 to about 800 nanometers, preferably in the range of about 400 to about 550 nanometers.
  • the backing and the abrasive slurry are brought into contact by any means such that the abrasive slurry wets the front surface of the backing.
  • the abrasive slurry is brought into contact with the backing by means of a contact nip roll, for example.
  • some form of energy such as described herein, is transmitted into the abrasive slurry by an energy source to at least partially cure the binder precursor.
  • the production tool can be transparent material (e.g. polyester, polyethylene or polypropylene) to transmit light radiation to the slurry contained in the cavities in the tool.
  • partial cure is meant that the binder precursor is polymerized to such a state that the abrasive slurry does not flow when the abrasive slurry is removed from the production tool.
  • the binder precursor if not fully cured, can be fully cured by any energy source after it is removed from the production tool.
  • Other details on the use of a production tool to make the abrasive article according to this preferred method is further described in U.S. Patent Nos. 5,152,917 (Pieper et al.), where the coated abrasive article that is produced is an inverse replica of the production tool, and 5,435,816 (Spurgeon et al.).
  • the abrasive slurry can be coated onto the backing and not into the cavities of the production tool.
  • the abrasive slurry coated backing is then brought into contact with the production tool such that the abrasive slurry flows into the cavities of the production tool.
  • the remaining steps to make the abrasive article are the same as detailed above.
  • the binder precursor is cured by radiation energy.
  • the radiation energy can be transmitted through the backing and/or through the production tool. If the radiation energy is transmitted through either the backing or production tool then, the backing or production tool should not appreciably absorb the radiation energy. Additionally, the radiation energy source should not appreciably degrade the backing or production tool. For instance ultraviolet light can be transmitted through a polyester film backing.
  • the production tool is made from certain thermoplastic materials, such as polyethylene, polypropylene, polyester, polycarbonate, poly(ether sulfone), poly(methyl methacrylate), polyurethanes, polyvinylchloride, or combinations thereof
  • ultraviolet or visible light can be transmitted through the production tool and into the abrasive slurry.
  • ultraviolet light stabilizers and/or antioxidants into the thermoplastic production tool. The more deformable material results in easier processing.
  • the operating conditions for making the abrasive article should be set such that excessive heat is not generated. If excessive heat is generated, this may distort or melt the thermoplastic tooling.
  • abrasive article After the abrasive article is made, it can be flexed and/or humidified prior to converting into a suitable form/shape before the abrasive article is used.
  • Another method to make an abrasive article is to bond a plurality of abrasive agglomerates to a backing. These abrasive agglomerates comprise a plurality of abrasive particles bonded together to form a shaped mass by means of a first binder. The resulting abrasive agglomerates are then dispersed in a second binder precursor and coated onto a backing. The second binder precursor is solidified to form a binder and the abrasive agglomerates are then bonded to the backing.
  • the abrasive agglomerates can include the optional additives as discussed above.
  • the abrasive agglomerates should have a desired rate of erodibility such that they break down during usage. Again, this erodibility rate can be determined by the abrasive particle type, first binder type, additive types and ratios thereof.
  • Abrasive agglomerates can be made by any conventional process such as those detailed in U.S. Patent Nos. 4,311,489; 4,652,275, 4,799,939, and 5,500,273.
  • the abrasive agglomerates are dispersed in a second binder precursor to form an abrasive slurry.
  • the remaining steps to make the abrasive article can be the same as that discussed herein.
  • the abrasive slurry can be applied onto the backing as knife coated, roll coated, sprayed, gravure coated, die coated, curtain coated or other conventional coating techniques. Then the abrasive slurry is exposed to an energy source to cure the binder precursor and convert the abrasive slurry into an abrasive composite.
  • a second method for making the abrasive article pertains to method in which the abrasive composites are non-precisely shaped or irregularly shaped.
  • the abrasive slurry is exposed to an energy source once the abrasive slurry is removed from the production tool.
  • the first step is to coat the front side of the backing with an abrasive slurry by any conventional technique such as drop die coater, roll coater, knife coater, curtain coater, vacuum die coater, or a die coater. If desired, it is possible to heat the abrasive slurry and/or subject the slurry to ultrasonics prior to coating to lower the viscosity.
  • the time between release of the abrasive slurry coated backing from the production tool to curing of the binder precursor is relatively minimal. If this time is too long, the abrasive slurry will flow and the pattern will distort to such a degree that the pattern essentially disappears.
  • Yet another variation is to spray or coat the abrasive slurry through a screen to generate a pattern. Then the binder precursor is cured or solidified to form the abrasive composites.
  • a further technique to make an abrasive article that has an abrasive coating having pattern or texture associated with it to provide a backing that is embossed and then coat the abrasive slurry over the backing. The abrasive coating follows the contour of the embossed backing to provide a pattern or textured coating.
  • Still another method to make an abrasive article is described in U.S. Patent
  • An abrasive slurry is coated into the recesses of an embossed backing.
  • the abrasive slurry contains abrasive particles, binder precursor and an expanding agent.
  • the resulting construction is exposed to conditions such that the expanding agent causes the abrasive slurry to expand above the front surface of the backing.
  • the binder precursor is solidified to form a binder and the abrasive slurry is converted into abrasive composites.
  • the abrasive article can be converted into any desired shape or form depending upon the desired configuration for glass polishing. This converting can be accomplished by slitting, die cutting or any suitable means. Methods of Polishing Glass
  • the glass Prior to polishing in accordance with the method of the invention, the glass will typically be subjected to a variety of physical processes (including abrading) to achieve the desired dimensions of the glass. These previous processes may leave scratches or expose defects in the glass surface which typically result in a dull appearing surface.
  • the present invention pertains to a method of polishing the glass surface to remove enough of the scratch depth and defects to provide a surface that can be polished to optical clarity.
  • the number of abrasive articles, time for polishing, types of abrasive particles and sizes of abrasive particles will depend upon various factors such as the size of the glass surface being polished, the severity of scratches and/or defects present in the glass prior to polishing and the composition of the glass itself. It is preferred to polish the glass in the presence of a liquid.
  • the liquid has several advantages associated with it. It inhibits heat build up during polishing and removes the swarf away from the polishing interface. "Swarf' is the term used to describe the actual glass debris that is abraded away by the abrasive article. In some instances, the glass swarf can damage the surface of the glass being polished. Thus it is desirable to remove the swarf from the interface.
  • Polishing in the presence of a liquid also results in a finer finish on the glass surface.
  • This liquid can be water, an organic lubricant, a detergent, a coolant or combinations thereof.
  • the liquid may further contain additives to enhance polishing. Water is generally the preferred liquid.
  • the abrasive article moves relative to the glass surface and is forced downward onto the glass surface preferably the force ranging from about 0.35 g/mm 2 to about 7.0 g/mm 2 , more preferably from about 0.7 g/mm 2 to about 3.5 g/mm 2 , and most preferably about 5 g/mm 2 . If the downward force is too high, then the abrasive article may not refine the scratch depth and in some instances may increase the scratch depth. Also, the abrasive article may wear excessively if the down force is too high. Conversely, if the downward force is too low, the abrasive article may not effectively refine the scratch depth and generate an optically clear surface.
  • the machine may have a rotational speed of about 25 rpm to about 2000 rpm, typically about 500 rpm.
  • a random orbital motion can be generated by a random orbital tool, and linear motion can be generated by a continuous abrasive belt.
  • the relative movement between glass and abrasive article may also depend on the dimensions of the glass. If the glass is relatively large, it may be preferred to move the abrasive article during polishing while the glass is held stationary.
  • the abrasive article is bonded to a support pad.
  • the support pad is typically a compressible material that provides support for the abrasive article.
  • the support pad will be made from a comformable material such that when the abrasive article is attached to the support pad, the resulting article can conform to the glass workpiece as necessary, especially for glass workpieces that are contoured or have a shape associated with them.
  • the support pad can be made from a polyurethane foam, rubber material, an elastomer, a rubber based foam or any other suitable material. The hardness and/or compressibility of the support pad material is selected to provide the desired polishing characteristics (cut rate, abrasive article product life and glass workpiece surface finish).
  • the support pad may have a continuous and relatively flat surface that the abrasive article is secured to.
  • the support pad may have a discontinuous surface in which there exists a series of raised portions and lower portions in which the abrasive article is secured to.
  • the abrasive article may be secured to only the raised portions.
  • the one abrasive article segment may be secured to more than one raised portion, such that the entire abrasive article is not fully supported.
  • the discontinuous surface in the support pad is selected to provide the desired fluid flow of the water and the desired polishing characteristics (cut rate, abrasive article product life and glass workpiece surface finish).
  • the backing for the abrasive article serves as the support pad.
  • the backing may be a foam backing such as a polyurethane foam.
  • the support pad can have any shape such as circular, rectangular, square, oval and the like.
  • the support pad can range in size (longest dimension) from about 5 cm to 1500 cm.
  • Attachment Means The abrasive article is secured to the support pad by an attachment means.
  • This attachment means may be a pressure sensitive adhesive, hook and loop attachment, a mechanical attachment or a permanent adhesive.
  • the attachment means should be such that the abrasive article can be firmly secured to the support pad and survive the rigors of glass polishing (wet environment, heat generation and pressures).
  • pressure sensitive adhesives suitable for this invention include latex crepe, rosin, acrylic polymers and copolymers e.g., polybutylacrylate, polyacrylate ester, vinyl ethers, e.g., polyvinyl n-butyl ether, alkyd adhesives, rubber adhesives, e.g., natural rubber, synthetic rubber, chlorinated rubber, and mixtures thereof.
  • the pressure sensitive adhesive may be coated out of water or solvent. In some instances, it is preferred to use a rubber based pressure sensitive adhesive that is coated out of a non-polar organic solvent. Alternatively, the pressure sensitive adhesive may be a transfer tape.
  • the abrasive article may contain a hook and loop type attachment system to secure the abrasive article to the support pad.
  • the loop fabric may be on the back side of the coated abrasive with hooks on the back up pad.
  • the hooks may be on the back side of the coated abrasive with the loops on the back up pad.
  • a flat circular glass test blank was provided which had a 7.62 cm (3 inch) diameter and a thickness of approximately 1.0 cm, commercially available under the trade designation CORNING #9061 from Corning Glass Co.
  • the glass material was placed into the power head of the grinder-polisher.
  • the 12 inch aluminum platform of the grinder-polisher rotated counter clockwise while the power head, into which the glass test blank was secured, rotated clockwise at 35 rpm.
  • An abrasive article tested was die cut to a 20.3 cm (8.0 inch) diameter circle and was adhered with a pressure sensitive adhesive directly onto a urethane backing pad which had a Shore A hardness of about 90 durometer.
  • the urethane backing pad was attached to a open cell, soft foam pad having a thickness of about 30mm cut from a sheet of the soft foam. This pad assembly was placed on the aluminum platform of the grinder/polisher. Tap water was sprayed onto the abrasive article at a flow rate of approximately 3 liters/minute to provide lubrication between the surface of the abrasive article and the glass test blank.
  • each glass test blank was abraded with a metal bonded diamond abrasive article commercially available under the trade designation "3M Flexible Diamond Ml 25" from 3M (St. Paul, MN). These diamond particles have an average particle size of approximately 125 micrometers.
  • real time contact between the abrasive article and the glass test blank surface was found to be greater than the set time because the grinder/polisher did not begin timing until the abrasive article was stabilized on the glass test blank surface. That is, some bouncing or skipping of the abrasive article on the glass surface was observed and the grinder/polisher began timing at the point in time when contact between the abrasive article and the glass surface was substantially constant.
  • real time polish interval i.e. the contact time between the abrasive article and the glass surface was about 25 seconds or less when the polishing time interval was set at 15 seconds or 10 seconds.
  • Topography B was produced as described above, except that the height of each truncated pyramid was about 760 micrometers, each base was about 880 micrometers per side and the top was about 640 micrometers per side. There were approximately 127 micrometers between the bases of adjacent truncated pyramids. The composites in each of these topographies are precisely shaped. Examples 1-18
  • Examples 19 and 21 used a mix of two diamond particle sizes of about 30 ⁇ m and about 45 ⁇ m.
  • Examples 20 and 22 used a mix of two diamond particle sizes of about 9 ⁇ m and about 15 ⁇ m.
  • Examples 21 and 22 were prepared as described for Examples 19 and 20, except that the production tool used was Topography B.
  • Examples 19 and 20 were tested using glass test blanks polished with the abrasive articles of Examples 4, 7, 8, and 9. Thus, the final Ra values became the input Ra values for Examples 19-22.
  • Examples 19 and 21 were tested using the RPP test procedure as described for Examples 1-18. These glass test blanks were than polishing using the abrasive article in Examples 20 and 22 using the RPP test procedure having a polish time interval of about 25 seconds, as described above.
  • a polishing system which included abrasive articles according to the invention in a polishing sequence of Examples 4, 7, 8, and 9 (average diamond particle size of about 74 ⁇ m); Example 19 (a blend of two diamond particle sizes of about 30 ⁇ m and about 45 ⁇ m) and Example 20 (a blend of two diamond particle sizes of about 9 ⁇ m and about 15 ⁇ m).
  • the initial Ra, prior to polishing with Examples 4, 7, 8, and 9 was about 1.4 ⁇ m or greater. Results are shown in Table 4.
  • Comparative Examples A - F were prepared as described for Examples 1-9, except using the ingredients listed in Table 5. For each pair of examples, (i.e., A and B, C and D, E and F), the first example used Topography A and the second example used Topography B.
  • the silicon carbide particles (SIC) had an average particle size of 60 micrometers.
  • Comparative Examples A-F were tested as in Examples 1-18, described above. Two samples of each Example were run; both results are listed. The results are shown in Table 6 below.
  • the Ra and Rtm values are the average of five measurements for each abrasive article tested.
  • the test procedure above was used to evaluate the abrasive articles tested except a silicone foam pad having a Shore A hardness of about 65 durometer was used in place of the urethane open cell, soft foam pad. As mentioned above, a change in the backing pad was expected to influence the polishing performance, both in grams of stock removed and surface finish as indicated by the Ra values. Additionally, the "polishing time” referred to in the tables below refers to the polish time interval actually set on the polisher/grinder apparatus. The input Ra value prior to polishing with the abrasive article in Example 4 was about 1.4 ⁇ m or greater.
  • Comparative Example K was a conventional aluminum oxide lapping abrasive article commercially available under the trade designation "Imperial Fre- Cut Microfinishing Film PSA (3M 266L)" from 3M.
  • the aluminum oxide particles had an average particle size of approximately 15 micrometers.
  • Comparative Example L was a conventional diamond lapping abrasive article commercially available under the trade designation "Imperial Diamond Lapping Film 3 mil backing (3M 662X)" from 3M.
  • the diamond particles had an average particle size of approximately 15 micrometers.
  • Comparative Example M was a conventional diamond lapping abrasive article commercially available under the trade designation "Imperial Diamond Lapping Film 3mil backing (3M 662X)" from 3M.
  • the diamond particles had an average particle size of approximately 9 micrometers.
  • Comparative Example N was a conventional resin bonded diamond abrasive article commercially available under the trade designation "Imperial Diamond Lapping Film - Type P PSA (3M 664X)" from 3M.
  • the diamond particles had an average particle size of approximately 9 micrometers.
  • Comparative Example O was a conventional beaded diamond abrasive article commercially available under the trade designation "Imperial Diamond Lapping Film - Type B PSA (3M 666X)" from 3M.
  • the diamond particles had an average particle size of approximately 9 micrometers.
  • Comparative Example P was a conventional aluminum oxide lapping abrasive article commercially available under the trade designation "Imperial Fre- Cut Microfinishing Film PSA (3M 266L)" from 3M.
  • the aluminum oxide particles had an average particle size of approximately 9 micrometers.
  • Comparative Example Q was prepared as described for Example 20, except that the abrasive particles used were white aluminum oxide having a 50/50 blend of average particle sizes of about 9 and about 15 micrometers.
  • Comparative Example R was prepared as described in Example 20 except silicon carbide abrasive particles were used instead of white aluminum oxide.
  • Comparative Example S was an abrasive article including cerium oxide particles and was prepared as described below.
  • the abrasive slurry included the following components:
  • BP 1 a pentaerythritol tetraacrylate commercially available from
  • BP2 a 2-phenoxyethyl acrylate resin commercially available from Sartomer, Co., Inc., under the trade designation 1 SR 3391 ;
  • CA1 a 3-methacryloxypropyltrimethoxysilane coupling agent commercially available form OSI Specialties, Inc., Danbury, CT under the trade designation 1 A- 1741; PH7: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide liquid photoinitiator commercially available from BASF, Charlotte, NC under the trade designation lLucirin LR 88931; CEO1 : ceria abrasive particles having an average particle size of about 0.5 micrometer, commercially available from Rhone Poulenc, Shelton, CT; and APS: an anionic polyester surfactant commercially available from ICI
  • This abrasive article was prepared from the cerium oxide slurry having the formulation above.
  • the abrasive article included precisely shaped abrasive composites.
  • the ceria particles had an average particle size of about 0.3 micrometers.
  • Comparative Examples G-S were not as effective at producing a nearly optically clear surface finish as compared to those results achieved with the abrasive article of Example 20 above. Although the Ra values may be comparable with those achieved using the abrasive article of Example 20, it was observed that the glass test blanks polished with the abrasive articles in Comparative Examples G-S exhibited a surface finish that had an overall haze, with some surface finishes exhibiting deep scratches. Comparative Examples T-W

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Surface Treatment Of Glass (AREA)
EP98903763A 1997-03-07 1998-01-28 Abrasive article for providing a clear surface finish on glass Withdrawn EP0964772A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US813228 1991-12-23
US08/813,228 US5888119A (en) 1997-03-07 1997-03-07 Method for providing a clear surface finish on glass
US813878 1997-03-07
US08/813,878 US5910471A (en) 1997-03-07 1997-03-07 Abrasive article for providing a clear surface finish on glass
PCT/US1998/001558 WO1998039142A1 (en) 1997-03-07 1998-01-28 Abrasive article for providing a clear surface finish on glass

Publications (1)

Publication Number Publication Date
EP0964772A1 true EP0964772A1 (en) 1999-12-22

Family

ID=27123709

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98903763A Withdrawn EP0964772A1 (en) 1997-03-07 1998-01-28 Abrasive article for providing a clear surface finish on glass

Country Status (10)

Country Link
EP (1) EP0964772A1 (enExample)
JP (1) JP2001512375A (enExample)
KR (1) KR100494605B1 (enExample)
CN (1) CN1188252C (enExample)
AU (1) AU727191B2 (enExample)
BR (1) BR9808152A (enExample)
CA (1) CA2281921A1 (enExample)
MY (1) MY129538A (enExample)
TW (1) TW411303B (enExample)
WO (1) WO1998039142A1 (enExample)

Families Citing this family (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6231629B1 (en) 1997-03-07 2001-05-15 3M Innovative Properties Company Abrasive article for providing a clear surface finish on glass
JP3373797B2 (ja) * 1998-10-28 2003-02-04 株式会社ノリタケカンパニーリミテド 樹脂含浸補強ビトリファイド砥石およびその製造方法
US6634929B1 (en) * 1999-04-23 2003-10-21 3M Innovative Properties Company Method for grinding glass
US6458018B1 (en) * 1999-04-23 2002-10-01 3M Innovative Properties Company Abrasive article suitable for abrading glass and glass ceramic workpieces
EP1052062A1 (en) 1999-05-03 2000-11-15 Applied Materials, Inc. Pré-conditioning fixed abrasive articles
US6616513B1 (en) 2000-04-07 2003-09-09 Applied Materials, Inc. Grid relief in CMP polishing pad to accurately measure pad wear, pad profile and pad wear profile
JP2003534137A (ja) * 2000-04-28 2003-11-18 スリーエム イノベイティブ プロパティズ カンパニー 研磨物品およびガラスの研削方法
US20020090901A1 (en) * 2000-11-03 2002-07-11 3M Innovative Properties Company Flexible abrasive product and method of making and using the same
US20020072296A1 (en) 2000-11-29 2002-06-13 Muilenburg Michael J. Abrasive article having a window system for polishing wafers, and methods
US20030017797A1 (en) * 2001-03-28 2003-01-23 Kendall Philip E. Dual cured abrasive articles
EP1758713B1 (en) * 2004-05-17 2009-04-01 Anthony David Pollasky Abrasive material and method of forming same
CN100513082C (zh) * 2004-10-06 2009-07-15 拉杰夫·巴贾 用于改善的化学机械抛光的方法和设备
US7169029B2 (en) * 2004-12-16 2007-01-30 3M Innovative Properties Company Resilient structured sanding article
JP5274021B2 (ja) * 2005-01-28 2013-08-28 サンーゴバン アブレイシブズ，インコーポレイティド 研磨用品及びその製造方法
US7344574B2 (en) 2005-06-27 2008-03-18 3M Innovative Properties Company Coated abrasive article, and method of making and using the same
MX2007013703A (es) * 2005-07-22 2008-01-24 Tdy Ind Inc Materiales compuestos.
KR101334012B1 (ko) * 2005-07-25 2013-12-02 호야 가부시키가이샤 마스크 블랭크용 기판의 제조방법, 마스크 블랭크의제조방법 및 마스크의 제조방법
US20070243798A1 (en) * 2006-04-18 2007-10-18 3M Innovative Properties Company Embossed structured abrasive article and method of making and using the same
CN101214637B (zh) * 2008-01-16 2010-09-29 郑州安华磨具有限公司 玻璃磨边轮
KR20130040808A (ko) * 2010-04-08 2013-04-24 아사히 가라스 가부시키가이샤 유리판의 제조 방법 및 제조 장치
JP5851124B2 (ja) * 2011-06-13 2016-02-03 スリーエム イノベイティブ プロパティズ カンパニー 研磨用構造体
CN103465155B (zh) * 2013-09-06 2016-05-11 蓝思科技股份有限公司 一种环氧树脂型金刚石研磨垫及其制备方法
JP6611414B2 (ja) 2014-05-27 2019-11-27 スリーエム イノベイティブ プロパティズ カンパニー 塗装表面の仕上げ方法及び研磨材料
JPWO2015194278A1 (ja) * 2014-06-17 2017-04-20 バンドー化学株式会社 研磨パッド及び研磨パッドの製造方法
CN104128880B (zh) * 2014-07-21 2017-01-11 蓝思科技股份有限公司 一种改性环氧树脂型陶瓷专用研磨垫及其制备方法
US9873180B2 (en) 2014-10-17 2018-01-23 Applied Materials, Inc. CMP pad construction with composite material properties using additive manufacturing processes
US9776361B2 (en) 2014-10-17 2017-10-03 Applied Materials, Inc. Polishing articles and integrated system and methods for manufacturing chemical mechanical polishing articles
US11745302B2 (en) 2014-10-17 2023-09-05 Applied Materials, Inc. Methods and precursor formulations for forming advanced polishing pads by use of an additive manufacturing process
US10875153B2 (en) 2014-10-17 2020-12-29 Applied Materials, Inc. Advanced polishing pad materials and formulations
CN107073688A (zh) * 2014-10-28 2017-08-18 阪东化学株式会社 研磨材以及研磨材的制造方法
CN104987708A (zh) * 2015-08-03 2015-10-21 金宝丽科技（苏州）有限公司 一种纤维增强尼龙复合材料及其制备方法
US10618141B2 (en) 2015-10-30 2020-04-14 Applied Materials, Inc. Apparatus for forming a polishing article that has a desired zeta potential
US10593574B2 (en) 2015-11-06 2020-03-17 Applied Materials, Inc. Techniques for combining CMP process tracking data with 3D printed CMP consumables
US10391605B2 (en) * 2016-01-19 2019-08-27 Applied Materials, Inc. Method and apparatus for forming porous advanced polishing pads using an additive manufacturing process
CN109564302B (zh) * 2016-08-12 2021-12-31 3M创新有限公司 截顶的珠膜构造及其制备方法
CN106271959A (zh) * 2016-08-15 2017-01-04 安徽省银锐玻璃机械有限公司 玻璃手工磨边的方法
KR20180072243A (ko) * 2016-12-21 2018-06-29 엠.씨.케이 (주) 연마체 수지 조성물 및 이에 의해 제조된 패드
GB201622441D0 (en) * 2016-12-30 2017-02-15 3M Innovative Properties Co Abrasive article and method of use
US11471999B2 (en) 2017-07-26 2022-10-18 Applied Materials, Inc. Integrated abrasive polishing pads and manufacturing methods
WO2019032286A1 (en) 2017-08-07 2019-02-14 Applied Materials, Inc. ABRASIVE DISTRIBUTION POLISHING PADS AND METHODS OF MAKING SAME
BR112020010936A2 (pt) * 2017-11-30 2020-11-17 Saint-Gobain Abrasives, Inc. artigos abrasivos e métodos de formação dos mesmos
KR102053651B1 (ko) * 2018-05-30 2019-12-09 이화다이아몬드공업 주식회사 사파이어, 실리콘카바이드, 유리 및 실리콘 웨이퍼 폴리싱을 위한 고정지립 패드 및 그 패드의 제조방법
CN108747876B (zh) * 2018-06-11 2021-03-19 河北思瑞恩新材料科技有限公司 一种漆面研磨砂碟的制备方法
CN109048698B (zh) * 2018-06-22 2020-08-28 广东伟艺研磨技术开发有限公司 一种聚氨酯抛磨轮及其制备方法
WO2020050932A1 (en) * 2018-09-04 2020-03-12 Applied Materials, Inc. Formulations for advanced polishing pads
EP3666461A1 (en) * 2018-12-12 2020-06-17 3M Innovative Properties Company Abrasive article
CN110922096A (zh) * 2019-12-16 2020-03-27 韶关大唐研磨材料有限公司 一种金刚石垫片及其制备方法
JP7713769B2 (ja) * 2019-12-20 2025-07-28 スリーエム イノベイティブ プロパティズ カンパニー 研磨シート及び研磨方法
CN112428165B (zh) * 2020-10-22 2021-10-22 德阳展源新材料科技有限公司 一种阻尼布抛光垫的制备方法
CN113211336B (zh) * 2021-03-31 2022-03-08 安徽禾臣新材料有限公司 一种电子显示屏边角抛光用抛光垫及其生产方法
CN114605922B (zh) * 2022-03-18 2023-05-09 北京通美晶体技术股份有限公司 一种快速抛光的化学抛光液及其制备方法
CN115926439A (zh) * 2022-04-20 2023-04-07 上海年与轻科技(集团)有限公司 一种鞋用光伏板及其制备方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0886558A1 (en) * 1996-03-15 1998-12-30 Minnesota Mining And Manufacturing Company Radiation curable abrasive article with tie coat and method
EP0938951A2 (en) * 1993-06-02 1999-09-01 Dai Nippon Printing Co., Ltd. Method of producing an abrasive tape

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2094824B (en) * 1981-03-12 1985-07-17 Interface Developments Ltd Abrasive member
JPS63196363A (ja) * 1987-02-10 1988-08-15 Asahi Glass Co Ltd 乱反射面を有する陰極線管の製造方法
JPS63283857A (ja) * 1987-05-15 1988-11-21 Asahi Chem Ind Co Ltd 研磨布
US5011513A (en) * 1989-05-31 1991-04-30 Norton Company Single step, radiation curable ophthalmic fining pad
JPH04201181A (ja) * 1990-11-30 1992-07-22 Ichikawa Woolen Textile Co Ltd 研磨用フェルト
JPH0768469A (ja) * 1993-09-03 1995-03-14 Asahi Glass Co Ltd ガラス板用研削加工シート

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0938951A2 (en) * 1993-06-02 1999-09-01 Dai Nippon Printing Co., Ltd. Method of producing an abrasive tape
EP0886558A1 (en) * 1996-03-15 1998-12-30 Minnesota Mining And Manufacturing Company Radiation curable abrasive article with tie coat and method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9839142A1 *

Also Published As

Publication number Publication date
KR20000075987A (ko) 2000-12-26
CN1188252C (zh) 2005-02-09
TW411303B (en) 2000-11-11
CA2281921A1 (en) 1998-09-11
AU6044798A (en) 1998-09-22
KR100494605B1 (ko) 2005-06-10
CN1249704A (zh) 2000-04-05
JP2001512375A (ja) 2001-08-21
MY129538A (en) 2007-04-30
BR9808152A (pt) 2000-03-28
AU727191B2 (en) 2000-12-07
WO1998039142A1 (en) 1998-09-11

Similar Documents

Publication Publication Date Title
US6110015A (en) Method for providing a clear surface finish on glass
US5910471A (en) Abrasive article for providing a clear surface finish on glass
AU727191B2 (en) Abrasive article for providing a clear surface finish on glass
US6231629B1 (en) Abrasive article for providing a clear surface finish on glass
EP1094918B1 (en) Abrasive article and method for grinding glass
US6634929B1 (en) Method for grinding glass
EP1276593B1 (en) Abrasive article and methods for grinding glass
EP1173307B1 (en) Abrasive article suitable for abrading glass and glass ceramic workpieces
EP0949986B1 (en) Method for the production of optical quality surfaces on glass
JP4808848B2 (ja) ガラス研削方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19991005

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE ES FR GB IT NL

17Q First examination report despatched

Effective date: 20010514

RTI1 Title (correction)

Free format text: METHOD FOR POLISHING A GLASS ARTICLE

RTI1 Title (correction)

Free format text: METHOD FOR POLISHING A GLASS ARTICLE

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20041112