JP2008542043A - Abrasive article and method for making and using the same - Google Patents

Abstract

  A coated abrasive article (200) having a reinforced vulcanized fiber backing (212) and an abrasive layer (230) secured thereto, and methods for making and using the same. The reinforced vulcanized fiber backing (212) has a backsize that includes a reaction product of components selected from the group consisting of cured latex emulsions, phenolic resins, and combinations thereof.

Description

  Coated abrasive articles according to the present invention are useful for polishing workpieces.

  Vulcanized fibers have been sold since the 19th century. The term “vulcanized fiber”, sometimes referred to as “vulcanized fiber” or “fish paper”, is obtained from paper, paper pulp, rayon, or cloth (eg, with metal chloride). ) Refers to a leather-like material typically formed from cellulose by compressing a chemically treated layer of cellulose. Due to their hydrophilic properties, vulcanized fibers usually tend to absorb moisture.

  Coated abrasive articles typically have an abrasive layer secured to a backing. Vulcanized fibers have been used for over 60 years as a backing for coated abrasive articles. One well-recognized problem of using vulcanized fiber backings in abrasive articles is that the coated abrasive is due to changes in the moisture content (eg, humidity) of the environment. An article shape deformation (for example, curling or cupping). Shape deformation may occur, for example, during manufacture, storage, or use. Furthermore, the shape deformation may occur towards and / or away from the abrasive layer. An example of such a variation of a prior art coated abrasive article having a vulcanized fiber backing is shown in FIG. 1, where the coated abrasive article is an abrasive. It exhibits a curl away from the layer. If excessive shape deformation occurs while manufacturing a coated abrasive article, it is usually discarded as scrap material. Furthermore, if excessive shape deformation occurs during storage or use, it typically results in dissatisfaction with the product, reduced product sales, and / or reduced product performance.

  Attempts to solve the shape deformation problem date back more than 50 years. For example, in Patent Document 1 (HP Kirchner, filed on Feb. 5, 1946, issued on Nov. 18, 1947), the second paragraph, lines 23-30, states that “a disc with an initially desired curvature is Although it is manufacturable by the process, the vulcanized fiber is very sensitive to changes in the moisture content of the atmosphere and is coated on one side of the material, particularly as in the abrasive disc of the present invention “Because it is sometimes, great difficulties are experienced by abrasive manufacturers.” In that patent, the problem was addressed by drying the article to achieve a desired level of curvature and then covering the vulcanized fiber backing with a water vapor impermeable sheet of material. From that time to date, a variety of other alternative backings have been developed that are moisture insensitive and dimensionally stable for abrasive articles coated with vulcanized fibers. It was.

Despite these various products, and primarily for economic reasons, vulcanized fiber backings are still used primarily in the commercial production of coated abrasive articles today. . For example, each major manufacturer of coated abrasives can cause moisture problems despite known moisture insensitive and dimensionally stable alternative backings for coated abrasive articles. Coated abrasive products having a vulcanized fiber backing are commercially available.
U.S. Pat. No. 2,431,258

  Therefore, there is a need for an abrasive product coated with a vulcanized fiber backing that is economical to manufacture and does not tend to accept unacceptable levels of shape deformation as humidity levels change. Remains in the coated abrasive industry.

  The present invention, in one aspect, provides a coated abrasive article comprising a vulcanized fiber backing having first and second opposing major surfaces, wherein the abrasive layer is on the first major surface. Fixed and a backsize is fixed to the second major surface, the backsize has a dry basis weight of 8 to 90 grams per square meter of coated abrasive article, and the backsize is It comprises a reaction product of a component selected from the group consisting of cured latex emulsions, phenolic resins, and combinations thereof.

  The present invention, in another aspect, provides a method of polishing a surface of a workpiece, the method comprising: providing a coated abrasive article according to the present invention, an abrasive layer on the surface of the workpiece Frictional contact and a step of polishing at least a portion of the surface of the workpiece by moving at least one of the abrasive layer and the surface of the workpiece relative to the other.

The present invention, in yet another aspect, provides a method of making a coated abrasive article, the method comprising:
Providing a vulcanized fiber backing having first and second opposing major surfaces;
Coating a cured backsize precursor on a second major surface of a vulcanized fiber backing and curing the backsize precursor to provide a backsize, wherein the backsize is coated At least one selected from the group consisting of cured latex emulsions, phenolic resins, and combinations thereof, having a dry basis weight of 8 to 90 grams per square meter of the abrasive article Processes that contain substances,
And a step of fixing the abrasive layer to the first main surface of the vulcanized fiber backing.

  Coated abrasive articles according to the present invention typically exhibit an industry acceptable level of shape deformation as humidity changes. Surprisingly, such an article, which was not possible before the present invention, allows the attachment of mechanical fasteners to the back size and thus to the vulcanized fiber backing by means of a welding process. It has also been found to be.

  In general, coated abrasive articles have abrasive particles affixed to a backing. More typically, the coated abrasive article includes a backing having two opposing major surfaces and an abrasive layer secured to one major surface of the backing. The abrasive layer typically includes abrasive particles and a binder that serves to fix the abrasive particles to the backing.

  In one embodiment, the coated abrasive article has an abrasive layer comprising a make layer, a size layer, and abrasive particles. In making such a coated abrasive article, a make layer comprising a first binder precursor is applied to one major surface of the backing and optionally partially cured. The abrasive particles are then at least partially embedded in the make layer (eg, by electrostatic coating) and the first binder precursor is sufficiently cured to secure the particles to the make layer ( Ie, crosslinked). Next, a size layer containing a second binder precursor is applied over the make layer and abrasive particles, followed by curing of the binder precursor. Such coated abrasive articles may further comprise an optional supersize layer disposed on at least a portion of the abrasive layer. When present, the supersize layer typically includes grinding aids and / or anti-clogging materials.

  In another embodiment, a coated abrasive article has an abrasive layer affixed to one major surface of a backing, the abrasive layer comprising a backing of a slurry consisting of a binder precursor and abrasive particles. It is provided by application on the material main surface followed by curing of the binder precursor.

  The backing contains vulcanized fibers, which are a partially regenerated cellulose dense material that retains the fiber structure and is usually calendered to be relatively smooth. Bring the surface. Vulcanized fibers can be obtained from, for example, Franklin Fiber-Lamitex Corporation of Wilmington, Delaware, or Yanmin Industry and Trade Company of Sanmenxia, Henan, China ( Yangmin IND. Trade Co., Ltd.).

  Vulcanized fiber backings useful for preparing coated abrasive articles according to the present invention are typically 0.02 to 5 millimeters, such as 0.05 to 2.5 millimeters, or 0.1 to 1 A thinner and thicker vulcanized paper backing having a thickness in the millimeter range may also be used. Furthermore, the density of the vulcanized fiber is typically in the range of 0.9 to 1.5 grams per cubic centimeter, although higher and lower density vulcanized fibers may also be used.

  At least a portion of one major surface of the vulcanized fiber backing, usually almost all, is coated with a cured resin, which is then at least partially cured, for example by drying and heating, A backsize is provided on a vulcanized fiber backing. Coating of the cured material onto the vulcanized fiber may be accomplished by any suitable coating method, for example, roll coating, bar coating, knife coating, kiss coating, or spray.

  The cured material should typically be coated on the vulcanized fiber so that it is distributed over at least a significant portion of the vulcanized fiber body, typically in a generally uniform manner. But this is not essential. For example, it will be appreciated that small amounts of local fluctuations or interruptions in the distribution (eg, coating voids) may be tolerated without significant adverse effects.

  The backsized vulcanized fiber backing optionally further includes an additional backing treatment, presize (ie, a layer that is secured to the backing on the major surface with the abrasive layer), Tie layer (ie, the layer between the abrasive layer and the major surface to which the abrasive layer is bonded), saturant (ie, backing treatment applied by a process that includes saturating the backing with saturant) And / or sub-size processing. The subsize is similar to a saturant except that it is applied to an already processed backing. Any of these backing treatments may include an antistatic material. The addition of antistatic materials can reduce the tendency of coated abrasive articles to accumulate static electricity when polished to wood or wood-like materials. Additional details regarding antistatic backings and backing processing can be found, for example, in US Pat. Nos. 5,108,463 (Buchanan), 5,137,542 (Buchanan et al.), No. 5, U.S. Pat. , 328,716 (Buchanan), and 5,560,753 (Schnabel et al.).

  The back size has a dry basis weight of 8 to 90 grams per square meter and is usually selected according to the composition of the back size. For example, in one embodiment where the reinforcing material is a reaction product of components comprising a cured latex emulsion, the backsize typically has a dry basis weight of 8-25 grams per square meter, 10-20 grams per square meter, or even Has a basis weight of 12 to 17 grams per square meter. In another embodiment where the reinforcing material is a reaction product of a component comprising a phenolic resin, the backsize typically has a dry basis weight of 15 to 90 grams per square meter, 45 to 55 grams per square meter, or even 50 per square meter. Has a basis weight of ~ 55 grams.

  Backsized vulcanized fiber backings typically have a thickness in the range of 0.15 to 2.0 millimeters, such as 0.5 to 1.3 millimeters, or even 0.8 to 0.9 millimeters. However, thicker and thinner vulcanized fiber backings that are backsized may also be used.

  The backsize includes at least one material that is a reaction product of at least one curable material selected from the group consisting of phenolic resins, cured latex emulsions, and combinations thereof. The reinforcing material may additionally include one or more optional additives such as, for example, fillers, antistatic agents, antioxidants, or colorants.

  The general term “phenolic resin” includes phenol-formaldehyde resins and resins containing compounds and aldehydes derived from other phenols. Some of the phenols can be replaced with one or more other phenols such as, for example, resorcinol, m-cresol, 3,5-xylenol, t-butylphenol, and p-phenylphenol. Similarly, some formaldehyde can be replaced with other aldehyde groups such as acetaldehyde, chloral, butyraldehyde, furfural, or acrolein.

  Examples of phenolic resins include resole-phenolic resins and novolac phenolic resins. Resole phenolic resins have a molar ratio of formaldehyde to phenol of 1: 1 or more, usually in the range of 1.5: 1.0 to 3.0: 1.0. Novolac phenolic resins have a molar ratio of formaldehyde to phenol of less than 1: 1.

  Typical resole phenolic resins contain a base catalyst. The presence of the basic catalyst accelerates the reaction of the phenolic resin, i.e. polymerization. The pH of resole phenolic resins is typically 6-12, more typically 7-10, and even more typically 7-9. Examples of suitable basic catalysts include sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, and combinations thereof. Typical catalysts for the reaction of formaldehyde with phenol are selected from Group I and Group II metal salts because they are generally highly reactive and low cost. Amines are also used as catalysts for phenol / aldehyde reactions. The amount of basic catalyst is typically 5 wt% or less, more typically 2 wt% or less, and even more typically 1 wt% or less, based on the weight of the phenolic resin. Resole phenolic resins are usually prepared from phenol and formaldehyde.

  Phenolic resins are usually coated as a solution with water and / or an organic solvent (eg alcohol). The solution typically contains 70% to 85% solids, but other concentrations may be used. If the solids content is very low, more energy is required to remove water and / or solvent. If the solids content is very high, the resulting phenolic resin will become too viscous, typically leading to processing problems.

  Examples of useful cured latex emulsions include cured latex emulsions derived from styrene, butadiene, acrylonitrile, neoprene, polyvinyl acetate, acrylamides that are esters of acrylic acid, and copolymers thereof. Mixtures of cured latex emulsions may also be used.

  Available cured latex emulsions include, for example, those available under the trademarks “RHOPLEX” and “ACRYSOL” from Rohm and Haas Company, Philadelphia, Pennsylvania; Allen, Pennsylvania; “FLEXCRYL” and “VALTAC” from Air Products & Chemicals Inc. in Allentown, Pennsylvania; Dow Raychold Specialty in Research Triangle Park, North Carolina (Research Triangle Park, NORTH CAROLINA) “SYNTHEMUL”, “TYCRYL”, and “TYLAC” from Dow Reichold Specialty Latex, LLC, “HYCAR”, “CA” from NOVEON, Cleveland, Ohio, Cleveland, Ohio BOCURE, GOOD-RITE, SANCURE, and VYCAR; “CHEMIGUM” available from Goodyear Tire and Rubber Co., Akron, Ohio, from ICI “NEOCRYL” available for purchase; and “BUTAFON” available from BASF. Latexes are typically used in combination with at least one additive that promotes curing (eg, a cross-linking agent) or may be used in combination with another curing material, unless it is self-curing (ie, self-crosslinking). .

  Examples of self-curing latexes that can be purchased include emulsions having the trademarks "CARBOCURE TSR-72" and "CARBOCURE TSR-201", all marketed by NOVEON, Cleveland, Ohio; Styrene butadiene emulsions having “GOOD-RITE SB-1168”, “GOOD-RITE SB-0706”, “GOOD-RITE 1800 × 73”; polyurethane dispersants having trademark “SANCURE AU-4010” (acrylic urethane hybrid) A polyvinyl acetate emulsion having the trademark “VYCAR VA-0450”; and a pvc-acrylic copolymer having the trademark “VYCAR TN-810”.

  The curable material may optionally contain one or more curing agents, eg, as described above or in addition. The selection of the curing agent is usually determined by the selected curing material and includes, for example, acids, bases, photocatalysts, hardeners, crosslinking agents (eg, polyepoxides, melamine resins, polyaziridines, polyvalent metal ions). Dicyandiamide, urea-formaldehyde resins, and mixtures thereof). When present, the amount of any additional curing agent is usually less than 5% of the dry weight of the latex intended to be cured (ie, crosslinked), but may be used in higher amounts. Examples of curing agents for various latexes can be found in US Pat. No. 6,306,514 (Weikel et al.).

  Commercially available curatives for latexes include, for example, trademarks “AEROTEX” (eg “AEROTEX M-3”, “AEROTEX 3730” from Cytec Industries, West Paterson, New Jersey). , And “AEROTEX 3030”), such as glycol urils available under the trademark “CYMEL 1172” and “CYMEL 1171” from Cytec Industries, and the trademarks “CYMEL 300”, eg, from Cytec Industries, Alkylated melamine resins available in CYMEL 303, CYMEL 373, and CYMEL 350; Bayer of Pittsburgh, Pennsylvania Polyaziridines available under the trademark “XAMA” (eg “XAMA-7” and “XAMA-2”) from the Corporation); for example, Resolution Performance Products in Houston, Texas Waterborne aliphatic epoxies available under the trademark “EPI-REZ”; for example, melamine-formaldehyde resins available under the trademark “BEETLE 65” from Cytec Industries.

  As noted above, coated abrasive articles typically have an abrasive layer secured to a backing. The abrasive layer typically comprises a make layer and a size layer and abrasive particles, or a layer of abrasive particles dispersed in a binder.

  According to one embodiment of the present invention, a coated abrasive article has an abrasive layer comprising a make layer and a size layer and abrasive particles, for example as shown in FIG. With reference now to FIG. 2, a representative coated abrasive article 200 includes a vulcanized fiber backing 212 having first and second opposing major surfaces 231, 232. A backsize 213 is affixed to the second major surface 232. Overcoated with an optional presize 215 and affixed to the backing 212 is an abrasive layer 230 comprising a make layer 216 in which abrasive grit 218 is embedded, a make layer 216 and And a size layer 217 that is overcoated with and adhered to the abrasive grit 218. An optional supersize 219 is overcoated on the size layer 217.

  The basis weight of the make layer used may depend, for example, on the intended use (s), the type of abrasive particle (s), and the properties of the coated abrasive article being prepared. Is generally in the range of 1, 2, or 5 to 20, 25, 400, or even 600 grams per square meter. The make layer is generally applied as a make layer precursor and subsequently solidifies (eg, by curing or cooling) to form a layer of bonding material that is strong enough to secure the abrasive particles to the backing. . The make layer precursor may be applied by any known coating method for applying the make layer precursor to a backing, such as roll coating, die extrusion coating, curtain coating, knife coating, gravure coating, and spraying. A coating is mentioned. Examples of make layer precursors include curable materials including phenolic resins, aminoplasts, polyacrylates (methacrylates), polyepoxides, polyisocyanates, animal skin glue, and combinations thereof.

  Abrasive particles are deposited on the make layer after the make layer precursor is applied to the backsized vulcanized fiber backing and before the make layer precursor is solidified (eg by curing) Is done.

  Exemplary and useful abrasive particles include molten aluminum oxide based materials such as aluminum oxide, aluminum oxide ceramics (including one or more metal oxide modifiers, and / or seed or nucleating agents). Heat treated aluminum oxide, silicon carbide, co-melted alumina-zirconia, diamond, cerium (IV) oxide, titanium diboride, cubic boron nitride, boron carbide, garnet, flint, Emery, abrasive particles extracted by the sol-gel method, and blends thereof. Examples of sol-gel abrasive particles include US Pat. Nos. 4,314,827 (Leitheiser et al.), 4,518,397 (Leitheiser et al.), 4,623,364. (Cottringer et al.), No. 4,744,802 (Schwabel), No. 4,770,671 (Monroe et al.), No. 4,881,951 (Wood ( Wood et al., 5,011,508 (Wald et al.), 5,090,968 (Pellow), 5,139,978 (Wood), 5th 201,916 (Berg et al.), 5,227,104 (Bauer), 5,366,523 (Rowenhorst et al.), 5,429,647. (Larmie), 5,498, 2 No. 9 (Rarumi (Larmie)), and include those described in No. 5,551,963 (Rarumi (Larmie)). The abrasive particles may be, for example, in the form of individual particles, agglomerates, abrasive composite particles, and mixtures thereof.

  Exemplary agglomerated particles are described, for example, in US Pat. Nos. 4,652,275 (Bloecher et al.) And 4,799,939 (Bloecher et al.). It is also within the scope of the present invention to use diluent erodible agglomerated particles as described, for example, in US Pat. No. 5,078,753 (Broberg et al.). The abrasive composite particles include abrasive particles in a binder.

  Representative abrasive composite particles are described, for example, in US Pat. No. 5,549,962 (Holmes et al.).

The coating weight for the abrasive particles may depend, for example, on the particular coated abrasive article desired, the method of depositing the abrasive particles, and the size of the abrasive particles, but is typically 1-2000 g. / M ² range.

The basis weight of the size layer will also necessarily vary depending on the intended use (s), the type (s) of abrasive particles, and the properties of the coated abrasive article being prepared However, it is generally in the range of 1 or 5 g / m ² to 300 or even 800 g / m ² or more.

  The size layer is generally applied as a size layer precursor and, when subsequently solidified (eg, by curing or cooling), forms a layer of bonding material that is strong enough to secure the abrasive particles to the make layer. . The size layer precursor may be applied by any known coating method for applying the size layer precursor to the backing, such as roll coating, die extrusion coating, curtain coating, knife coating, gravure coating, and spraying. A coating is mentioned. Examples of size layer precursors include phenolic resins, aminoplasts, polyacrylates (methacrylates), polyepoxides, polyisocyanates, animal skin glue, urea-formaldehyde resins, melamine-formaldehyde resins, and combinations thereof And a curable substance containing at least one of the following.

  Details regarding coated abrasive articles comprising abrasive particles and a make layer and a size layer and optionally a supersize are well known and are described, for example, in US Pat. No. 4,734,104 (Broberg). ), 4,737,163 (Larkey), 5,203,884 (Buchanan et al.), 5,152,917 (Pieper et al.), 5,378. 251 (Culler et al.), 5,417,726 (Stout et al.), 5,436,063 (Follett et al.), 5,496,386 (Blow) (Broberg et al.), 5,609,706 (Benedict et al.), 5,520,711 (Helmin), 5,954,844 (Law et al.) 5th and 9th 1,674 (Gagliardi et al.), 4,751,138 (Tumey et al.), 5,766,277 (DeVoe et al.), 6,077,601 ( DeVoe et al., 6,228,133 (Thurber et al.), And 5,975,988 (Christianson).

  According to another embodiment of the present invention, a coated abrasive article has an abrasive layer comprising a layer of abrasive particles dispersed in a binder, for example, as shown in FIG. Referring now to FIG. 3, an exemplary coated abrasive article 300 includes a vulcanized fiber backing 312 having first and second opposing major surfaces 331,332. A back size 313 is fixed to the second main surface 332. An arbitrary presize 315 is fixed to the main surface 331. Overcoated with any presize 315 and affixed to the backing 312 is an abrasive layer 330 that includes a plurality of abrasive grit 318 distributed throughout the binder 309.

  In some embodiments of coated abrasive articles according to the present invention, the abrasive layer comprises abrasive particles dispersed in a binder (usually as a slurry of abrasive particles in a binder precursor). Coated). Slurry coating techniques are well known in the abrasive arts and include, for example, US Pat. Nos. 5,378,251 (Culler et al.), 5,942,015 (Culler et al.), And 6,277,160 (Stubbs et al.). Examples of suitable binder precursors include curable materials including phenolic resins, aminoplasts, polyacrylates (methacrylates), polyepoxides, polyisocyanates, and combinations thereof. The abrasive particles used in this embodiment include all of those previously listed herein.

  Coated abrasive articles according to the present invention can be converted into, for example, belts, tapes, rolls, disks (including perforated disks), and / or sheets.

  According to the present invention, it has been found that the problem of cupping and / or curling due to moisture absorption is reduced to a point where it is generally no longer uncomfortable for the user. The moisture absorption (eg, by weight) of the coated abrasive of the present invention is surprising because it is typically substantially the same as the corresponding coated abrasive of the prior art.

  Furthermore, surprisingly, the coated abrasive according to the present invention typically has a corresponding coated abrasive of the prior art, typically under at least some conditions (eg under high humidity conditions). It is also observed that the scraping is improved compared to the material.

  For belt applications, the two free ends of the abrasive sheet may be joined together using known methods to form a splice belt. A seamless belt may also be formed, for example, as described in US Pat. No. 5,573,619 (Benedict et al.).

  In one embodiment, a coated abrasive disc according to the present invention may have a mechanical fastener secured to a vulcanized fiber backing. For example, referring now to FIG. 4, a machine in which a representative coated abrasive disc 400 is secured to the backsize coated major surface 432 of the vulcanized fiber backing 412 of the abrasive disc 420. With a mechanical fastener 490. The abrasive disc 420 may be, for example, a disc made from either coated abrasive article 200 or 300.

  Suitable techniques for attaching mechanical fasteners include, for example, adhesives, rivets, welding. Typical welding techniques include, for example, ultrasonic welding, infrared welding, vibration welding, and friction welding (including spin welding). Welding is also performed as a stepwise process in which at least a portion of the thermoplastic resin is heated until at least partially softened or melted, and then the softened or melted thermoplastic resin is secured to the abrasive article. Also good. Of the techniques described above, at least spin welding is usually simple, effective, and convenient. The surprising that mechanical fasteners can be successfully spin welded to backsize coated vulcanized fiber backings, which is normally not possible with the use of vulcanized fiber backings It was found. Further details regarding mechanical fasteners and welding techniques can be found in, for example, US patent application 10 / 828,119 (Fritz et al., Filed Apr. 20, 2004), both assigned to the assignee of the present invention. Can be found.

  Coated abrasive articles according to the present invention are useful for polishing workpieces. One such method includes frictionally contacting at least a portion of the abrasive layer of the coated abrasive article with at least a portion of the surface of the workpiece, and at least the coated abrasive article or workpiece. Moving one relative to the other includes polishing at least a portion of the surface.

  Examples of workpiece materials include metals, alloys, exotic metal alloys, ceramics, glass, wood, wood-like materials, composites, painted surfaces, plastics, reinforced plastics, stones And / or combinations thereof. The workpiece may be flat or have an associated shape or contour. Examples of specific workpieces include metal components, plastic components, slabs, camshafts, crankshafts, furniture, and turbine blades.

  The coated abrasive article according to the present invention may be used by hand and / or used in combination with a machine. At least one or both of the coated abrasive article and workpiece generally move relative to the other during polishing. Polishing may be performed in a wet state or in a dry state. Typical liquids for wet polishing include water, water containing conventional corrosion inhibiting compounds, lubricants, oils, soap solutions, and cutting fluids. The liquid may also contain an antifoaming agent, an oil taker and the like.

  The objects and advantages of this invention are further illustrated by the following non-limiting examples, which illustrate the specific materials and amounts listed therein, as well as other conditions and details, which may It should not be construed as limiting.

  Unless otherwise noted, all parts, percentages, ratios, etc. in the examples and elsewhere in this specification are by weight, and all reagents used in the examples are from general chemical suppliers, For example, it is available or available from Sigma-Aldrich Company, Saint Louis, Missouri, or can be synthesized by conventional methods. The vulcanized fiber disk used in the examples had a diameter of 18 cm (7 inches) and a central hole of 2.2 cm (7/8 inches).

  The following abbreviations are used throughout the examples.

Test method Shape measurement procedure A
The abrasive disc to be evaluated is removed from the restricting bale and placed on a shelf in a chamber controlled at 24 ° C. at 15% RH (relative humidity) for 48 hours (down the abrasive side). Arranged) individually. For each example material, four discs were investigated. The shape of each disc was measured using a laser height gauge capable of measuring in units of 10 micrometers (model LG10, obtained from Banner Engineering, Minneapolis, Minnesota). The laser apparatus was used to measure the height of the four points on each disk, the lowest two points and the highest two points. The difference between the highest and lowest averages was reported as the Δ height for each disk. The net shape out of the plane toward the backing was positive (+). The net shape out of plane toward the abrasive side was reported as negative (-). This procedure was repeated for environments where RH was 30%, 45%, 60%, and 75% and the temperature was kept at 24 ° C. The reported value for each case is the average of the difference in measurements obtained with four replicate discs.

Shape measurement procedure B
Eight abrasive discs were removed from the bale and pre-conditioned by placing them individually (with the abrasive side down) in a chamber controlled at 24 ° C. at 45% RH. After 48 hours of preconditioning, the shape of each disk was measured with the laser described in “Shape Measurement Procedure A” above. Next, four of the disks were placed in a chamber controlled at 24 ° C. at 20% RH, and the remaining four were placed in a chamber controlled at 24 ° C. at 60% RH. After 48 hours, 8 discs were simultaneously removed from the chamber and measured with a laser measuring machine. The reported value for each case is the average of the measurements obtained with 4 replicate discs. Four additional measurements were made after each 48 hour, for a total test duration of 10 days.

Shape measurement procedure C
The abrasive disc to be evaluated is removed from the restricting bale and the laser height at which the shape of each disc (ie deviation from flatness) can be measured in units of 10 micrometers. Measured using a measuring machine (Model LG10, obtained from Banner Engineering, Minneapolis, Minnesota). Each disk was placed on the table with the central hole farthest from the table. The height of the center hole from the table was measured using a laser height measuring machine. The net shape out of the plane toward the backing was positive (+). The net shape out of plane toward the abrasive side was reported as negative (-). After the initial measurement, each group of 10 disks 3 was controlled in a chamber controlled at 24 ° C. at 20% RH (relative humidity), 24 ° C. at 45% RH, and 24 ° C. at 70% RH (relative humidity). It was suspended in a central hole on a horizontal rod for 2 weeks. Next, the shape was measured for each disc and the absolute value of the change from the initial state to the final state after humidity treatment, i.e. the change in height, was reported for the average value of 10 discs.

Grinding test A grinding test was designed to measure the scraping speed of the coated abrasive disc. Test discs were conditioned for 2 days at 45% RH and 24 ° C. Then, prior to testing, half of these preconditioned disks were placed in an environment of 20% RH at 24 ° C and the other half in 60% RH at 24 ° C for one week prior to testing. Each final adjusted abrasive disc was used to grind a 1.25 cm x 18 cm face of a 1018 mild steel workpiece. The grinder used was a constant load hydraulic disc grinder. A constant load between the workpiece and the abrasive disc was supplied by a load spring. The support pad for the grinder was an aluminum support pad with an inclination of about 7 degrees extending inward from the edge toward the center 3.5 cm. The disc was fixed to the aluminum pad by a holding nut and was driven at 575.9 rad / s (5,500 rpm). The load between the support pad and disk and the workpiece was about 6.8 kg. Each disc was used to grind a separate workpiece for each of 15 60 second intervals. The initial scraping was the amount of metal removed during the first 60 seconds of grinding. The final scrap was taken as the amount of metal removed during the 15th 60 second interval. Unless otherwise stated, total scrap is the cumulative amount of metal removed during the test. Initial, final, and gross scrapings were reported in grams.

Grinding test 2
Grinding test 2 was also designed to measure the scraping speed of the coated abrasive disc. Test discs were conditioned for 2 days at 45% RH and 24 ° C. Each abrasive disc was used to grind a 1.25 cm × 18 cm face of a 1018 mild steel workpiece. The grinder used was a constant load hydraulic disc grinder. A constant load between the workpiece and the abrasive disc was supplied by a load spring. The support pad for the grinder was an aluminum support pad with an inclination of about 7 degrees extending inward from the edge toward the center 3.5 cm. The disc was fixed to the aluminum pad by a holding nut and was driven at 575.9 rad / s (5,500 rpm). The load between the support pad and disk and the workpiece was about 5.9 kg. Each disc was used to grind the workpiece for 60 second intervals. At the end of each interval, the workpiece was changed. The scraping (metal removal) was measured after each 60 second grinding. The end of the test was defined as when the scraping during the 60 second interval was less than 40 grams. Unless otherwise noted, total scrap is the cumulative amount of metal removed during the test. Total scraping (average of 6 discs) was reported in grams.

Spin Welding Procedure The spin welding test was performed according to the procedure of US Pat. No. 5,931,729 (Penttila et al.), Powell, McGee Associates, Shoreview, Minnesota. , Inc.) using a spin welding apparatus obtained under the trademark “PMA SPINWELD 90”. The adjustable parameters of this device include the input air pressure in psi (kPa) and the welding time in uniquely specified units. The evaluation criteria for this procedure are reported in Table I (below).

Examples 1-4 and Comparative Example A
Examples 1-4 and Comparative Example A illustrate the effect of various backsize composition compositions and wet additions on the shape stability of the resulting abrasive discs. The backsize composition and wet addition of these examples are reported in Table II (below).

  Example 1 was prepared by applying AR1 to one side of a 305 mm wide VF web with a three roll coater. The backsize coating was allowed to dry for 3 minutes in an oven set at 85 ° C. to a dry weight of about 12.4 grams per square meter (gsm). The backsized web was wound on a roll and left conditioned for 7-10 days in a 50% RH environment. An abrasive coating consisting of 184 gsm make coating (PM2), 552 gsm particle coating (AP) and 339 gsm size coating (PM3) was applied and cured on the backsized and conditioned web. A short piece of cured abrasive web was wound on a loose roll and exposed to steam at 65 ° C. for 1 hour. From the wet web, a 178 mm diameter and 22 mm center hole disc was cut using a punch press. The disc was then passed twice through a 3.8 cm (1.5 inch) bar bending machine across the disc surface in an orthogonal direction. Bent discs were stacked, tied between wooden flanges and packaged, and further cured at 100 ° C. for 24 hours. The packed disc was finally left conditioned for 10 days in a 24% environment at 45% RH.

  Example 2 was prepared as in Example 1, except that the weight of AR1 was 21.6 gsm (dried and reduced to about 7.5 gsm).

  Example 3 was prepared as in Example 1 except that the SBR was applied to a vulcanized fiber web at a weight of 24.5 gsm (dried and reduced to about 12.5 gsm). .

  Example 4 was prepared as in Example 1 except that PM1 was applied to a vulcanized fiber web at a weight of 38.9 gsm (dried and reduced to about 20.8 gsm). . The oven temperature was raised to 121 ° C.

  Comparative Example A is a control example, prepared according to Example 1, but the back size was not applied to the vulcanized fiber web.

  Examples 1-4 and the comparative example A were evaluation about the shape change by the "shape measurement procedure A". Results are reported in mm in Table III (below). A coated abrasive disc prepared according to Example 1 is shown in FIG.

Examples 5-11 and Comparative Example B
Examples 5-11 and Comparative Example B illustrate the effect of the composition and wet addition of various backsize compositions on the shape stability of the resulting abrasive disc. The backsize composition and wet addition of these examples are reported below.

  Example 5 was prepared as in Example 4 except that PM2 was applied to a vulcanized fiber web at a weight of 105 gsm (dried and reduced to about 86.3 gsm). The oven temperature was 121 ° C.

  Example 6 was prepared as in Example 5, except that PM2 was applied to a vulcanized fiber web at a weight of 62.4 gsm (dried and reduced to about 51.8 gsm). .

  Example 7 was prepared as in Example 5, except that PM2 was applied to a vulcanized fiber web at a weight of 20.8 gsm (dried and reduced to about 17.3 gsm). .

  Example 8 was prepared as in Example 1 except that the weight of AR1 was 62.3 gsm (dried and reduced to about 21.8 gsm).

  Example 9 was prepared as in Example 1 except that the weight of AR1 was 37.4 gsm (dried and reduced to about 13.1 gsm).

  Example 10 was prepared as in Example 1 except that the weight of AR1 was 18.5 gsm (dried and reduced to about 6.5 gsm).

  Example 11 was prepared as in Example 1 except that AR1 was applied to the same side of the vulcanized fiber web in three separate runs. The total addition amount for 3 runs was about 178 gsm (62.3 dry gsm). When abrasive discs were cut from this material and bent, the back size tended to fall off in flakes and no longer provided a uniform backside coating. These discs curled more intensely than the untreated comparison material.

  Comparative Example B was prepared according to Example 1 except that the back size was not applied to the backing.

  Examples 5 to 11 and Comparative Example B were evaluations on the shape change by the “shape measurement procedure B”.

  Comparative Examples C and D are vulcanized fiber disks of ANSI 50 grade abrasive with a diameter of 18 cm (7 inches) and a 2.2 cm (7/8 inch) center hole, Chicago, Illinois Trademark “50 GRIT” from Marvel Abrasives of Chicago, Illinois under the trademark “50 GRIT CG CERAMIC RESIN BOND FIBRE DISC” and Norton Company of Worcester, Massachusetts Obtained at “GREENLYTE PLUS”. The shape results are recorded in Table IV (below) in mm.

  The abrasive discs of Example 10 and Comparative Examples B and C were evaluated using a “polishing test”. Test results are recorded in Table V (below).

Examples 12 to 14 and Comparative Example E (spin welding)
Example 12 was prepared using a 51 mm diameter disc cut from the abrasive disc according to Example 1. A nylon button was applied to the web by the “spin welding procedure” with the machine settings as shown in Table VII.

  Example 13 was prepared and tested according to Example 12, except that the abrasive disc was from Example 4.

  Example 14 was prepared and tested according to Example 12 except that the abrasive disc was from Example 5.

  Comparative Example E was prepared and tested according to Example 12 except that the abrasive disc was from Comparative Example A.

  The results of the spin welding evaluation for Examples 12-14 and Comparative Example E are reported in Table VI (below).

Example 15
Example 15 was prepared by applying PM2 to one side of a 305 mm wide VF web with a two roll coater. The backsize coating was allowed to dry for 3 minutes in an oven set at 116 ° C. to a dry add on weight of about 8.8 gsm. The backsized web was inverted and the coating and drying steps were repeated to create a presized (ie presized) backsized (ie backsized) web. . The presized and backsized webs were wound on rolls and left to conditioned for 7-10 days in a 50% RH environment. An abrasive coating consisting of 188 gsm make coating (PM2), 799 gsm particle coating (AP2) and 448 gsm size coating (PM3) was applied and cured to a backsized and presized conditioned web. A short piece of cured abrasive web was wound on a loose roll and exposed to steam at 65 ° C. for 1 hour. From the wet web, a 178 mm diameter and 22 mm center hole disc was cut using a punch press. The disk was then passed twice through a 2.5 cm (1.0 inch) bar bender in an orthogonal direction across the disk surface. Bent discs were stacked, tied between wooden flanges and packaged, and further cured at 100 ° C. for 24 hours. The packed discs were finally left conditioned for 5 days at 24% at 70% RH and then for another 5 days at 24% at 45% RH.

Comparative Example F
Comparative Example F was prepared as in Example 15 except that both the backsize and presize coatings were omitted.

  Example 15 and Comparative Example F were tested by “Shape Measurement Procedure C” and “Grinding Test 2”. Results are reported in Table VII (below).

Example 16
In Example 16, an additional process of applying a presize (PM1, 38.9 gsm wet addition (20.8 gsm dry addition)) to the front side of the VF web by the same procedure as described for the backsize application in Example 4 is performed. And prepared as in Example 4.

  Example 16 was tested by “Shape Measurement Procedure A”. The Δ height was 16.65 mm.

A photograph of a prior art coated abrasive disc. 1 is a cross-sectional side view of an exemplary coated abrasive article according to one embodiment of the present invention. FIG. 1 is a cross-sectional side view of an exemplary coated abrasive article according to one embodiment of the present invention. FIG. 1 is a perspective view of an exemplary coated abrasive disc having welded mechanical fasteners according to one embodiment of the present invention. FIG. 2 is a photograph of a coated abrasive disc prepared according to Example 1. FIG.

Claims (23)

  A coated abrasive article comprising a vulcanized fiber backing having first and second opposing major surfaces, wherein an abrasive layer is affixed to the first major surface, and a backsize is said Affixed to a second major surface, the back size has a dry basis weight of 8 to 90 grams per square meter of the coated abrasive article, and the back size is a cured latex emulsion, phenol A coated abrasive article comprising a reaction product of a component selected from the group consisting of resins and combinations thereof.   The coated abrasive article of claim 1, wherein a presize is affixed to the first major surface of the vulcanized fiber backing.   The coated abrasive article of claim 2, wherein the presize comprises the same components as the backsize.   The coated abrasive article of claim 1, wherein the abrasive article comprises an abrasive disc or an endless belt.   The coated abrasive article of claim 1, wherein the backsize comprises a cured latex emulsion and has a dry basis weight of 8 to 25 grams per square meter of the coated abrasive article.   The coated abrasive article of claim 1, wherein the backsize comprises a phenolic resin and has a dry basis weight of 15 to 90 grams per square meter of the coated abrasive article.   The coated abrasive article of claim 1, wherein the vulcanized fiber backing has a thickness in the range of 0.5 to 1.3 millimeters.   The coated abrasive article of claim 1, wherein the abrasive layer comprises a make layer and a size layer.   The coated abrasive article of claim 1, wherein the abrasive layer comprises abrasive particles dispersed in a binder.   The abrasive layer comprises a reaction product of a component comprising at least one of polyepoxide, polyacrylate (methacrylate), urea-formaldehyde resin, melamine-formaldehyde resin, phenol resin, or combinations thereof. A coated abrasive article as described.   The coated abrasive article of claim 1, wherein the abrasive article further comprises at least one of presize, subsize, saturant, tie layer, or supersize.   The coated abrasive article of claim 1, wherein the abrasive article comprises a disk and the abrasive article further comprises a mechanical fastener welded to the backsize. In a method for polishing a surface of a workpiece, the method includes:
Providing a coated abrasive article according to claim 1;
Bringing the abrasive layer into frictional contact with the surface of the workpiece; and moving at least one of the abrasive layer and the surface of the workpiece relative to the other to at least one of the surfaces of the workpiece. A method for polishing a surface of a workpiece, comprising a step of polishing a part. In a method of making a coated abrasive article, the method includes:
Providing a vulcanized fiber backing having first and second opposing major surfaces;
Coating the cured backsize precursor on the second main surface of the vulcanized fiber backing and curing the backsize precursor to provide a backsize, the backsize Has a dry basis weight of 8 to 90 grams per square meter of the coated abrasive article, and the backsize precursor is selected from the group consisting of cured latex emulsions, phenolic resins, and combinations thereof A coated abrasive article, comprising: a step comprising: a step of: affixing an abrasive layer to the first major surface of the vulcanized fiber backing; Method.   15. The method of making a coated abrasive article according to claim 14, further comprising converting the coated abrasive article to an abrasive disk or endless belt.   15. The method of making a coated abrasive article according to claim 14, wherein the backsize comprises a cured latex emulsion and has a dry basis weight of 8 to 25 grams per square meter of the coated abrasive article.   15. A method of making a coated abrasive article according to claim 14, wherein the backsize comprises a phenolic resin and has a dry basis weight of 15 to 90 grams per square meter of the coated abrasive article.   15. The method of making a coated abrasive article according to claim 14, wherein the vulcanized fiber backing has a thickness in the range of 0.5 to 1.3 millimeters.   The method of making a coated abrasive article according to claim 14, wherein the abrasive layer comprises a make layer and a size layer.   20. The method of making a coated abrasive article according to claim 19, further comprising applying a supersize to the size layer.   15. A method of making a coated abrasive article according to claim 14, wherein the abrasive layer comprises abrasive particles distributed in a binder.   15. The abrasive layer comprises a reaction product of a component comprising at least one of polyepoxide, polyacrylate (methacrylate), urea-formaldehyde resin, melamine formaldehyde resin, phenol resin, or combinations thereof. A method of making a coated abrasive article.   15. The method of making a coated abrasive article according to claim 14, further comprising welding a mechanical fastener to the backsize.

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