CN113710423A

CN113710423A - Abrasive article and method of making same

Info

Publication number: CN113710423A
Application number: CN202080029083.0A
Authority: CN
Inventors: 格雷戈里·P·索兰松; 伊利亚·戈罗迪舍; 欧内斯特·L·瑟伯; 托马斯·J·纳尔逊
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2019-04-16
Filing date: 2020-03-25
Publication date: 2021-11-26
Also published as: EP3956104A1; WO2020212779A1; US20220203501A1

Abstract

An abrasive article includes abrasive particles adhered to a substrate by a binder material. The binder material comprises an at least partially cured resole phenolic resin and an organic polymeric rheology modifier. The at least partially cured resole phenolic resin is present in an amount from 75 wt% to 99.99 wt% of the total weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier. Methods of making abrasive articles are also disclosed.

Description

Abrasive article and method of making same

Technical Field

The present disclosure relates to abrasive articles comprising phenolic binder materials and abrasive particles and methods of making the same.

Background

Abrasive articles typically comprise abrasive particles (also referred to as "abrasive particles") retained in a binder. During the manufacture of various types of abrasive articles, abrasive particles are deposited in an oriented manner (e.g., by electrostatic coating or by some mechanical placement technique) on a binder material precursor. Typically, the most desirable orientation of the abrasive particles is substantially perpendicular to the surface of the backing.

In the case of nonwoven abrasive articles, a binder material precursor is coated on a lofty, open-celled nonwoven web, the abrasive particles are adhered to the binder material precursor, and the binder material precursor is then sufficiently cured to retain the abrasive particles during use.

For certain coated abrasive articles (e.g., abrasive discs), the backing is a relatively dense, planar substrate (e.g., vulcanized fiber or woven or knitted fabric, optionally treated with an impregnant to increase durability). A make layer precursor (or make layer) containing a first binder material precursor is applied to the backing, and abrasive particles are then partially embedded in the make layer precursor. In many cases, the abrasive particles are embedded in the make layer precursor with a degree of orientation; for example by electrostatic coating or by mechanical placement techniques. The make layer precursor is then at least partially cured to retain the abrasive particles while the size layer precursor (or size layer) containing the second binder material precursor overlies the at least partially cured make layer precursor and abrasive particles. Next, if the size layer precursor and the make layer precursor are not sufficiently cured, both are cured to form the coated abrasive article.

For both types of abrasive articles, it is generally desirable that the abrasive particles retain their original orientation upon embedding the binder material precursor until they have been sufficiently cured to hold them in place. This is particularly troublesome when the binder precursor material is too flowable such that the particles tip under gravity, or if the binder precursor material is too hard such that the particles do not adhere to the binder precursor material and tip over again due to gravity.

Tipping of the abrasive particles after deposition is particularly problematic for resole binder material precursors. It is desirable to have a resole resin based binder material precursor so that the initial orientation of the applied abrasive particles is maintained until sufficient curing has occurred.

Disclosure of Invention

The present disclosure overcomes such problems by using curable compositions (typically thixotropic compositions) that are suitable for use in making phenolic resole-based abrasive articles. The curable composition comprises a liquid phenolic resin and an organic polymeric rheology modifier comprising an alkali swellable/soluble polymer. It has now been found that these organic polymeric rheology modifiers can better control abrasive tip density in all mineral coating techniques that can produce the same or better performing abrasives at lower precision shaped abrasive particle loadings than existing commercial products.

Organic polymeric rheology modifiers are known to impart pseudoplastic flow characteristics. In particular, alkali-swellable/soluble emulsion (ASE) polymers, hydrophobically modified alkali-swellable/soluble emulsion (HASE) polymers, and hydrophobically modified ethoxylated urethane (HEUR) polymers have been used in aqueous compositions of latex paints, personal care products, and drilling muds. In a first aspect, the present disclosure provides a method of making an abrasive article, the method comprising:

disposing a curable composition on a substrate, wherein the curable composition comprises a phenolic resole resin and an organic polymeric rheology modifier, wherein the organic polymeric rheology modifier comprises an alkali-swellable/soluble polymer, and wherein the phenolic resole resin is present in an amount from 75 wt% to 99.99 wt% of the total weight of the phenolic resole resin and the organic polymeric rheology modifier;

adhering abrasive particles to the curable composition; and

the curable composition is at least partially cured.

In a second aspect, the present disclosure provides an abrasive article comprising abrasive particles adhered to a substrate by a binder material comprising an at least partially cured resole phenolic resin and an organic polymeric rheology modifier, wherein the resole phenolic resin is present in an amount of 75 wt% to 99.99 wt% of the total weight of the resole phenolic resin and the organic polymeric rheology modifier.

As used herein:

"alkali-swellable" means capable of at least partially swelling in an aqueous solution of a water-soluble base having a pH greater than 7;

"alkali-swellable/soluble" means at least one of alkali-swellable or alkali-soluble (i.e., alkali-swellable and/or alkali-soluble); and

unless otherwise specifically indicated, "polymer" refers to an organic polymer.

The features and advantages of the present disclosure will be further understood upon consideration of the detailed description and appended claims.

Drawings

FIG. 1 is a cross-sectional side view of an exemplary coated abrasive article 100 according to the present disclosure.

Fig. 2A is a perspective view of an exemplary nonwoven abrasive article 200 according to the present disclosure.

Fig. 2B is an enlarged view of region 2B of the nonwoven abrasive article 200 shown in fig. 2A.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the disclosure. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope and spirit of the principles of this disclosure. The figures may not be drawn to scale.

Detailed Description

An exemplary embodiment of a coated abrasive article according to the present disclosure is shown in fig. 1. Referring now to fig. 1, coated abrasive article 100 has backing 120 and abrasive layer 130. Abrasive layer 130 comprises abrasive particles 140 secured to major surface 170 of backing 120 (substrate) by make coat 150 and size coat 160.

Coated abrasive articles according to the present disclosure may, if desired, comprise additional layers, such as, for example, an optional supersize layer superimposed on the abrasive layer, or may also comprise a backing antistatic treatment layer, if desired.

Useful backings include, for example, backings known in the art for making coated abrasive articles. Typically, the backing has two opposing major surfaces, but this is not required. The backing typically has a thickness in the range of about 0.02 mm to about 5mm, advantageously in the range of about 0.05mm to about 2.5 mm, and more advantageously in the range of about 0.1mm to about 1.0 mm, although thicknesses outside of these ranges may also be used. Generally, the backing should be strong enough to resist tearing or other damage during the abrading process. The thickness and smoothness of the backing should also be suitable to provide the desired thickness and smoothness of the coated abrasive article; for example, depending on the intended application or use of the coated abrasive article.

An exemplary backing includes: densified nonwoven fabrics (e.g., needle punched, melt spun, spunbond, hydroentangled, or meltblown nonwoven fabrics), knitted fabrics, stitch bonded fabrics, and/or woven fabrics; a scrim; a polymer film; their treated forms; and combinations of two or more of these materials.

The fabric backing may be made of any known fiber, whether natural, synthetic, or a blend of natural and synthetic. Examples of useful fibrous materials include fibers or yarns comprising: polyesters (e.g., polyethylene terephthalate), polyamides (e.g., hexamethylene adipamide, polycaprolactam), polypropylene, acrylics (formed from acrylonitrile polymers), cellulose acetate, polyvinylidene chloride-vinyl chloride copolymers, vinyl chloride-acrylonitrile copolymers, graphite, polyimide, silk, cotton, flax, jute, hemp, or rayon. Useful fibers may be of natural material, or of recycled or waste material recovered from, for example, garment cutting, carpet manufacturing, fiber manufacturing, or textile processing. Useful fibers can be homogeneous or a composite such as a bicomponent fiber (e.g., a co-spun sheath-core fiber). These fibers may be drawn and crimped, but may also be continuous filaments, such as those formed by an extrusion process.

The backing can have any suitable basis weight; typically in the range of 100 to 1250 grams per square meter (gsm), more typically in the range of 450 to 600gsm, and even more typically in the range of 450 to 575 gsm. In many embodiments (e.g., belt and plate), the backing typically has good flexibility; however, this is not required (e.g., vulcanized fibre discs). To promote adhesion of the binder resin to the backing, one or more surfaces of the backing may be modified by known methods, including corona discharge, ultraviolet light irradiation, electron beam irradiation, flame discharge, and/or roughening.

The make layer is formed by at least partially curing a make layer precursor, which is a curable composition according to the present disclosure. The curable composition includes a resole phenolic resin and an organic polymeric rheology modifier that helps maintain the initial placement and orientation of the abrasive particles during manufacture.

Generally, phenolic resins are formed by the condensation of phenol and formaldehyde and are generally classified as resole or novolak phenolic resins. The novolac phenolic resin is acid catalyzed and has a formaldehyde to phenol molar ratio of less than 1: 1. Resol/resol phenolic resins may be catalyzed with a basic catalyst and have a formaldehyde to phenol molar ratio of greater than or equal to one, typically between 1.0 and 3.0, so that pendant methylol groups are present. Suitable basic catalysts for catalyzing the reaction between the aldehyde and phenol components of the resole resin include sodium hydroxide, barium hydroxide, potassium hydroxide, calcium hydroxide, organic amines, and sodium carbonate, all as a catalyst solution dissolved in water.

The resole is typically coated as a solution with water and/or an organic solvent (e.g., an alcohol). Typically, the solution comprises solids from about 70 wt% to about 85 wt%, although other concentrations may be used. If the solids content is very low, more energy is required to remove the water and/or solvent. If the solids content is very high, the viscosity of the resulting phenolic resin is too high, which often leads to processing problems.

Phenolic resins are well known and readily available from commercial sources. Examples of commercially available resoles that may be used in the practice of the present disclosure include those sold under the tradename VARCUM (e.g., 29217, 29306, 29318, 29338, 29353) by Durez Corporation (Durez Corporation); those sold under the trade name aerofen (e.g., aerofen 295) by Ashland Chemical company of barton, Florida, usa; and those sold under the trade name PHENOLITE (e.g., PHENOLITE TD-2207) by South of the river Chemical limited, Seoul, South Korea.

A general discussion of phenolic resins and their manufacture is given in the following references: Kirk-Othmer, "Encyclopedia of Chemical Technology,4th edition, John West International publishing company, 1996, New York, Vol.18, p.603-644 (Kirk-Othmer, Encyclopedia of Chemical Technology,4th Ed., John Wiley & Sons,1996, New York, Vol.18, pp.603-644).

In addition to the resole, the curable composition contains an organic polymeric rheology modifier comprising an alkali swellable/soluble polymer. The curable composition comprises a resole phenolic resin (typically diluted with water) and an organic polymeric rheology modifier comprising an alkali swellable/soluble polymer. Wherein the amount of resole phenolic resin comprises 75 to 99.99 wt% (preferably 82 to 99.99 wt%, and even more preferably 88 to 99.99 wt%) of the total weight of resole phenolic resin and organic polymeric rheology modifier on a solids basis. Thus, the curable composition comprises from 1 to 25 wt%, preferably from 1 to 18 wt%, and more preferably from 1 to 12 wt% of the organic polymeric rheology modifier, based on the total weight of the resole resin and the organic polymeric rheology modifier. Combinations of more than one resole and/or more than one organic polymeric rheology modifier may be used if desired.

Alkali-swellable/soluble polymers suitable for use as organic polymer rheology modifiers include, for example, alkali-swellable/soluble emulsion (ASE) organic polymers, hydrophobically modified alkali-swellable/soluble emulsion polymers (HASE), and hydrophobically modified ethoxylated urethane polymers (HEUR).

The organic polymer rheology modifier may be selected from the group consisting of alkali-swellable/soluble acrylic emulsion polymer (ASE), hydrophobically modified alkali-swellable/soluble acrylic emulsion polymer (HASE), and hydrophobically modified ethoxylated urethane (HEUR) organic polymer.

Alkali-swellable/soluble emulsion (ASE) rheology modifiers are dispersions in water of insoluble acrylic polymers having a high percentage of acidic groups distributed throughout their polymer chain. When these acidic groups are neutralized, the salt formed is hydrated. Depending on the concentration of acidic groups, molecular weight and degree of crosslinking, the salts swell or become completely water-soluble in aqueous solution.

As the concentration of neutralized polymer in the aqueous formulation increases, the polymer chains swell, resulting in an increase in viscosity.

ASE polymers can be synthesized from acids and acrylate comonomers and are typically prepared by emulsion polymerization. Exemplary commercially available ASE polymers include ACUSOL 810A polymer, ACUSOL 830 polymer, ACUSOL 835 polymer, and ACUSOL 842 polymer.

Hydrophobically modified alkali swellable/soluble emulsion (HASE) polymers are commonly used to modify the rheology of aqueous emulsion systems. Under the influence of alkali, organic or inorganic substances, HASE particles gradually swell and expand to form a three-dimensional network by intermolecular hydrophobic aggregation between the HASE polymer chains and/or with the emulsion components. This network combines with the hydrodynamic exclusion volume created by the swollen HASE chains to produce the desired thickening effect. The network is sensitive to applied stress, decomposes under shear, and recovers when the stress is relieved.

HASE rheology modifiers can be prepared from the following monomers: (a) an ethylenically unsaturated carboxylic acid, (b) a nonionic ethylenically unsaturated monomer, and (c) an ethylenically unsaturated hydrophobic monomer. Representative HASE polymer systems include the HASE polymer systems shown in EP 226097B1(van Phung et al), EP 705852B1 (dolan et al), U.S. Pat. No.4,384,096 (Sonnabend), and U.S. Pat. No. 5,874,495 (Robinson).

Exemplary commercially available HASE polymers include the HASE polymers sold by the Dow Chemical company (Dow Chemical) under the tradenames acuol 801S, ACUSOL 805S, ACUSOL 820 and acuol 823.

ASE and HASE rheology modifiers are pH triggered thickeners. Whether each emulsion polymer is water-swellable or water-soluble generally depends on its molecular weight. Both forms are acceptable. More details on the synthesis of ASE and HASE polymers can be found, for example, in U.S. patent No. 9,631,165(Droege et al).

Hydrophobically modified ethoxylated urethane (HEUR) polymers are synthesized substantially from alcohols, diisocyanates and one or more polyalkylene glycols. HEUR is a water-soluble polymer containing hydrophobic groups and is classified as an associative thickener due to the hydrophobic groups associating with each other in water. Unlike HASE, HEUR is a non-ionic substance and does not rely on bases to activate the thickening mechanism. When their hydrophobic groups associate with other hydrophobic components in a given formulation, they create intramolecular or intermolecular linkages. In general terms, the strength of the association depends on the number, size and frequency of the hydrophobic caps or closure units. HEUR forms micelles as common surfactants do. The micelle then links between the other components by association with its surface. This establishes a three-dimensional network.

Exemplary commercially available HEUR polymers include HEUR polymers sold by Dow Chemical under the trade names ACUSOL 880, ACUSOL 882, ACYSOL RM-2020, and ACYSOL RM-8W.

More details on HEUR can be found, for example, in U.S. patent application publication nos. 2017/0198238(Kensicher et al) and 2017/0130072(McCulloch et al) and U.S. patent nos. 7,741,402(Bobsein et al) and 8,779,055(Rabasco et al).

The make layer and size layer are formed by at least partially curing the respective precursors (i.e., make layer precursor and size layer precursor).

The make layer precursor comprises a curable composition according to the present disclosure. The curable composition may also contain additives such as fibers, lubricants, wetting agents, surfactants, pigments, dyes, antistatic agents (e.g., carbon black, vanadium oxide, and/or graphite, etc.), coupling agents (e.g., silanes, titanates, and/or zircoaluminates, etc.), plasticizers, suspending agents, and the like. The amounts of these optional additives are selected to provide preferred characteristics. Coupling agents can improve adhesion to the abrasive particles and/or filler. The curable composition may be thermally cured, radiation cured, or combinations thereof.

The curable composition may also comprise filler materials, dilute abrasive particles (e.g., as described below), or grinding aids, typically in the form of a particulate material. Typically, the particulate material is an inorganic material. Examples of fillers useful in the present disclosure include: metal carbonates (e.g., calcium carbonate (e.g., chalk, calcite, marl, travertine, marble, and limestone), calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silica (e.g., quartz, glass beads, glass bubbles, and glass fibers) silicates (e.g., talc, clay, (montmorillonite) feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminate, sodium silicate), metal sulfates (e.g., calcium sulfate, barium sulfate, sodium aluminum sulfate, aluminum sulfate), gypsum, vermiculite, wood flour, aluminum trihydrate, carbon black, metal oxides (e.g., calcium oxide (lime), aluminum oxide, titanium dioxide), and metal sulfites (e.g., calcium sulfite).

The size layer precursor comprises a thermosetting resin. Examples of suitable thermosetting resins that can be used in the size layer precursor include, for example, free-radically polymerizable monomers and/or oligomers, epoxy resins, acrylic resins, polyurethane resins, phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, aminoplast resins, cyanate resins, or combinations thereof. Useful binder precursors include thermally curable resins and radiation curable resins, which may be cured, for example, by heat and/or by exposure to radiation. Additional details regarding the size coat precursor can be found in U.S. Pat. No.4,588,419 (Caul et al), U.S. Pat. No.4,751,138 (Tumey et al), and U.S. Pat. No. 5,436,063(Follett et al).

The size coat precursor may also be modified by various additives (e.g., fibers, lubricants, wetting agents, surfactants, pigments, dyes, antistatic agents (e.g., carbon black, vanadium oxide, and/or graphite), coupling agents (e.g., silanes, titanates, zircoaluminates, etc.), plasticizers, suspending agents). Catalysts and/or initiators may be added to the thermosetting resin; for example, according to conventional practice, and depending on the resin used.

Thermal energy is often applied to promote curing of a thermoset resin (e.g., a curable composition according to the present disclosure); however, other energy sources (e.g., microwave radiation, infrared light, ultraviolet light, visible light) may also be used. The choice will generally depend on the particular resin system selected.

Useful abrasive particles can be the result of a pulverizing operation (e.g., pulverized abrasive particles that have been classified according to shape and size) or the result of a shaping operation (i.e., shaped abrasive particles) in which an abrasive precursor material is shaped (e.g., molded), dried, and converted to a ceramic material. Combinations of abrasive particles produced by the comminution and abrasive particles produced by the shaping operation may also be used. The abrasive particles may be in the form of, for example, individual particles, agglomerates, composite particles, and mixtures thereof.

The abrasive particles should have sufficient hardness and surface roughness to function as crushed abrasive particles in the grinding process. Preferably, the abrasive particles have a mohs hardness of at least 4, at least 5, at least 6, at least 7, or even at least 8.

Suitable abrasive particles include, for example, crushed abrasive particles comprising: fused aluminum oxide, heat treated aluminum oxide, white fused aluminum oxide, CERAMIC aluminum oxide materials (such as the CERAMIC aluminum oxide materials commercially available as 3M CERAMIC ABRASIVE GRAIN from 3M Company (3M Company, st. paul, Minnesota) of st paul, Minnesota), brown aluminum oxide, blue aluminum oxide, silicon carbide (including green silicon carbide), titanium diboride, boron carbide, tungsten carbide, garnet, titanium carbide, diamond, cubic boron nitride, garnet, fused aluminum oxide-zirconia, iron oxide, chromia, zirconia, titanium dioxide, tin oxide, quartz, feldspar, flint, emery, sol-gel process-produced CERAMICs (e.g., alpha aluminum oxide), and combinations thereof. Examples of sol-gel prepared abrasive particles from which the abrasive particles can be isolated and methods for their preparation can be found in U.S. patent 4,314,827 (leithiser et al); 4,623,364(Cottringer et al), 4,744,802(Schwabel), 4,770,671(Monroe et al), and 4,881,951(Monroe et al). It is also contemplated that the abrasive particles may include abrasive agglomerates such as, for example, those described in U.S. Pat. No.4,652,275(Bloecher et al) or U.S. Pat. No.4,799,939(Bloecher et al). In some embodiments, the abrasive particles may be surface treated with a coupling agent (e.g., an organosilane coupling agent) or other physical treatment (e.g., iron oxide or titanium oxide) to enhance adhesion of the crushed abrasive particles to the binder. The abrasive particles may be treated prior to their combination with the binder, or they may be surface treated in situ by including a coupling agent into the binder.

Preferably, the abrasive particles (and in particular the abrasive particles) comprise ceramic abrasive particles, such as for example sol-gel prepared polycrystalline alpha alumina particles. Ceramic crushed abrasive particles comprised of crystallites of alpha alumina, magnesium aluminate spinel, and rare earth hexaaluminate can be prepared using sol-gel alpha alumina particle precursors according to the methods described in, for example, U.S. patent No. 5,213,591(Celikkaya et al) and U.S. published patent applications 2009/0165394a1(Culler et al) and 2009/0169816a1(Erickson et al). Additional details regarding the process of making sol-gel process-made abrasive particles can be found, for example, in U.S. Pat. Nos. 4,314,827(Leitheiser), 5,152,917(Pieper et Al), 5,435,816(Spurgeon et Al), 5,672,097(Hoopman et Al), 5,946,991(Hoopman et Al), 5,975,987(Hoopman et Al), and 6,129,540(Hoopman et Al), as well as in U.S. published patent application 2009/0165394Al (Culler et Al).

In some preferred embodiments, useful abrasive particles (particularly in the case of abrasive particles) can be shaped abrasive particles, which can be found in U.S. Pat. nos. 5,201,916 (Berg); 5,366,523(Rowenhorst (Re 35,570)) and 5,984,988 (Berg). U.S. patent No.8,034,137(Erickson et al) describes alumina abrasive particles that have been formed into a particular shape and then crushed to form chips that retain a portion of their original shape characteristics. In some embodiments, the abrasive particles are precisely shaped (i.e., the shape of the particles is determined, at least in part, by the shape of the cavities in the production tool used to make them). Details on such abrasive particles and methods of making them can be found, for example, in U.S. Pat. Nos. 8,142,531(Adefris et al), 8,142,891(Culler et al), and 8,142,532(Erickson et al); and U.S. patent application publications 2012/0227333 (adegris et al), 2013/0040537(Schwabel et al), and 2013/0125477 (adegris). One particularly useful precisely shaped abrasive particle shape is that of a truncated triangular pyramid with sloped sidewalls; for example, as described in the references cited above.

Surface coatings on abrasive particles can be used to improve adhesion between the abrasive particles and the binder material, or to aid in electrostatic deposition of the abrasive particles. In one embodiment, the surface coating described in U.S. Pat. No. 5,352,254(Celikkaya) may be used in an amount of 0.1% to 2% of the surface coating relative to the weight of the abrasive particles. Such surface coatings are described in U.S. patent 5,213,591(Celikkaya et al); 5,011,508(Wald et al), 1,910,444(Nicholson), 3,041,156(Rowse et al), 5,009,675(Kunz et al), 5,085,671(Martin et al), 4,997,461(Markhoff-Matheny et al) and 5,042,991(Kunz et al). In addition, the surface coating may prevent the shaped abrasive particles from being capped. "capping" is a term that describes the phenomenon where metal particles from the workpiece being abraded are welded to the top of the abrasive particles. Surface coatings that perform the above functions are known to those skilled in the art.

In some embodiments, the length and/or width of the abrasive particles may be selected to be in the range of 0.1 micrometers to 3.5 millimeters (mm), more typically in the range of 0.05mm to 3.0mm, and more typically in the range of 0.1mm to 2.6mm, although other lengths and widths may also be used.

Abrasive particles having a thickness in the range of 0.1 micrometers to 1.6 millimeters, more typically 1 micrometer to 1.2 millimeters, may be selected, although other thicknesses may also be used. In some embodiments, the abrasive particles can have an aspect ratio (length to thickness) of at least 2, 3, 4,5, 6, or more.

In general, the crushed abrasive particles can be independently sized according to an abrasives industry recognized specified nominal grade. Exemplary abrasive industry recognized grading standards include those promulgated by ANSI (american national standards institute), FEPA (european union of manufacturers of abrasives), and JIS (japanese industrial standard). Such industry accepted grading standards include: for example, ANSI 4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 30, ANSI 36, ANSI 40, ANSI 50, ANSI 60, ANSI 80, ANSI 100, ANSI 120, ANSI 150, ANSI 180, ANSI 220, ANSI 240, ANSI 280, ANSI 320, ANSI 360, ANSI 400, and ANSI 600; FEPA P8, FEPA P12, FEPA P16, FEPA P24, FEPA P30, FEPA P36, FEPA P40, FEPA P50, FEPA P60, FEPA P80, FEPA P100, FEPA P120, FEPA P150, FEPA P180, FEPA P220, FEPA P320, FEPA P400, FEPA P500, FEPA P600, FEPA P800, FEPA P1000, FEPA P1200; FEPA F8, FEPA F12, FEPA F16, and FEPA F24; and JIS 8, JIS 12, JIS 16, JIS 24, JIS 36, JIS 46, JIS 54, JIS 60, JIS 80, JIS 100, JIS 150, JIS 180, JIS 220, JIS 240, JIS 280, JIS 320, JIS 360, JIS 400, JIS 600, JIS 800, JIS 1000, JIS 1500, JIS 2500, JIS 4000, JIS 6000, JIS 8000 and JIS 10,000. More typically, the size of the comminuted alumina particles and the alumina-based abrasive particles prepared by the seedless sol-gel process are independently set to ANSI 60 and 80 or FEPA F36, F46, F54 and F60 or FEPA P60 and P80 classification standards.

Alternatively, the abrasive particles may be formulated according to ASTM E-11 "Standard Specification for Wire Cloth and Sieves for Testing Purposes" using American Standard test Sieves. ASTM E-11 specifies the design and construction requirements for a test screen that uses a woven screen cloth media mounted in a frame to classify materials according to a specified particle size. Typical designations are 18+20, which means that the shaped abrasive particles pass through a test sieve number 18, which conforms to ASTM E-11 specifications, but remain on a test sieve number 20, which conforms to ASTM E-11 specifications. In one embodiment, the shaped abrasive particles have a particle size of: such that a majority of the particles pass through the 18 mesh test sieve and may be retained on the 20, 25, 30, 35, 40, 45 or 50 mesh visual test sieve. In various embodiments, the shaped abrasive particles can have a nominal sieve rating comprising: -18+20, -20+25, -25+30, -30+35, -35+40, -40+45, -45+50, -50+60, -60+70, -70+80, -80+100, -100+120, -120+140, -140+170, -170+200, -200+230, -230+270, -270+325, -325+400, -400+450, -450+500, or-500 + 635. Alternatively, a custom mesh size such as-90 +100 may be used.

Grinding aids are materials that significantly affect the chemical and physical processes of grinding, resulting in improved performance. Grinding aids encompass a wide variety of different materials and can be inorganic-based or organic-based. Examples of chemical groups of grinding aids include waxes, organic halide compounds, halide salts, metals, and alloys thereof. The organic halide compound will typically decompose during milling and release a halogen acid or a gaseous halide. Examples of such materials include chlorinated paraffins, such as naphthalene tetrachloride, naphthalene pentachloride, and polyvinyl chloride. Examples of halide salts include sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluorides, potassium chloride, and magnesium chloride. Examples of metals include tin, lead, bismuth, cobalt, antimony, cadmium, iron, and titanium.

Other miscellaneous grinding aids include sulfur, organic sulfur compounds, graphite, and metal sulfides. Combinations of different grinding aids can be used and in some cases this can produce a synergistic enhancement.

Grinding aids are particularly useful in coated abrasives. In coated abrasive articles, grinding aids are typically used in a supersize coat that is applied over the surface of the abrasive particles. However, grinding aids are sometimes added to the size coat. Typically, the amount of grinding aid incorporated into the coated abrasive article is about 50 to 800 grams per square meter (g/m)²) Preferably about 80g/m²To 475g/m²。

More details regarding coated abrasive articles and their methods of manufacture can be found, for example, in U.S. patent 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), 5,436,063(Follett et al), 5,496,386(Broberg et al), 5,609,706(Benedict et al), 5,520,711(Helmin), 5,961,674(Gagliardi et al), and 5,975,988 (Christianson).

Nonwoven abrasive articles typically comprise an open pore, porous lofty fibrous web having abrasive particles distributed throughout the structure and adhesively bonded therein by a resole resin-based binder material according to the present disclosure. Examples of filaments include polyester fibers, polyamide fibers, and polyaramid fibers.

An exemplary embodiment of a nonwoven abrasive article 200 is shown in fig. 2A and 2B. Referring now to fig. 2A and 2B, a lofty, open cell, low density fibrous web 210 is formed from entangled fibers 115. Abrasive particles 140 are secured to web 210 on the exposed surfaces of fibers 115 by a binder material 250 that also bonds fibers 115 together at the points where they contact each other, thereby orienting the cut points outward relative to fibers 115.

Nonwoven webs suitable for use are known in the abrasive art. Typically, the nonwoven web comprises an entangled web of fibers. The fibers may comprise continuous fibers, staple fibers, or a combination thereof. For example, the web may include staple fibers having a length of at least about 20 millimeters (mm), at least about 30mm, or at least about 40mm and less than about 110mm, less than about 85mm, or less than about 65mm, although shorter and longer fibers (e.g., continuous filaments) may also be used. The fibers can have a fineness or linear density of at least about 1.7 decitex (dtex, i.e., grams/10000 meters), at least about 6dtex, or at least about 17dtex, and less than about 560dtex, less than about 280dtex, or less than about 120dtex, although fibers with lesser and/or greater linear densities may also be useful. Mixtures of fibers having different linear densities may be used, for example, to provide abrasive articles that will produce a particularly preferred surface finish when in use. If a spunbond nonwoven is used, the filaments may have a much larger diameter, for example, a diameter of up to 2mm or more.

The webs may be formed using, for example, conventional air-laid, carded, stitch-bonded, spunbond, wet-laid and/or meltblown processes. Airlaid webs can be prepared using equipment such as, for example, the Landao Machine Company of Macedon, N.Y., available under the trade name RANDO WEBBER.

The nonwoven web is typically selected to be compatible with the adherent binder and abrasive particles, while also being compatible with other components of the article, and may generally withstand some process conditions (e.g., temperature), such as those employed during application and curing of the curable binder precursor. The fibers may be selected to affect properties of the abrasive article, such as, for example, flexibility, elasticity, durability or shelf life, abrasiveness, and finishing properties. Examples of fibers that may be suitable include natural fibers, synthetic fibers, and mixtures of natural and/or synthetic fibers. Examples of synthetic fibers include those made from polyester (e.g., polyethylene terephthalate), nylon (e.g., hexamethylene adipamide, polycaprolactam), polypropylene, acrylonitrile (i.e., acrylic resins), rayon, cellulose acetate, polyvinylidene chloride-vinyl chloride copolymers, and vinyl chloride-acrylonitrile copolymers. Examples of suitable natural fibers include cotton, wool, jute, and hemp. The fibers may be virgin material or recycled or waste material recovered from, for example, garment cutting, carpet manufacturing, fiber manufacturing, or textile processing. The fibers may be homogenous or may be a composite material, such as bicomponent fibers (e.g., co-spun sheath-core fibers). These fibers may be drawn and crimped, but may also be continuous filaments, such as those formed by an extrusion process. Combinations of fibers may also be used.

Prior to coating and/or impregnation with the curable composition (i.e., binder precursor composition), the weight per unit area (i.e., basis weight) of the nonwoven web, as measured prior to any coating (e.g., coating with the curable binder precursor or optional pre-bond resin), is typically: at least about 50 grams per square meter (gsm), at least about 100gsm, or at least about 150 gsm; and/or less than about 600gsm, less than about 500gsm, or less than about 400gsm, although greater and lesser basis weights may also be used. Additionally, the thickness of the web prior to impregnation with the curable binder precursor is typically at least about 3mm, at least about 6mm, or at least about 10 mm; and/or less than about 100mm, less than about 50mm, or less than about 25mm, although greater and lesser thicknesses may also be used.

In many cases, it is useful to apply a pre-bond resin to the nonwoven web prior to coating with the curable binder precursor, as is known in the abrasive art. For example, the prebond resin serves to help maintain the integrity of the nonwoven web during processing, and may also facilitate bonding of the urethane base to the nonwoven web. Examples of pre-bond resins include phenolic resins, polyurethane resins, hide glue, acrylic resins, urea-formaldehyde resins, melamine-formaldehyde resins, epoxy resins, and combinations thereof. The amount of pre-bond resin used in this manner is typically adjusted to correspond to the minimum amount of bonding the fibers together at their intersection points. In those instances where the nonwoven fibrous web comprises thermally bondable fibers, thermal bonding of the nonwoven fibrous web may also help to maintain web integrity during processing.

In those nonwoven abrasive particles that include lofty, open cell nonwoven fibrous webs (e.g., hand pads and surface conditioning disks and belts, wing brushes, or nonwoven abrasive webs used to make unitary or convoluted abrasive wheels), many of the seams between adjacent fibers are substantially unfilled by the binder and abrasive particles, resulting in a very low density composite structure having a network of many relatively large, interconnected voids. The resulting lightweight lofty, extremely open cell fibrous structure is essentially non-occlusive and non-filling, especially when used with liquids such as water and oil. These structures can also be easily cleaned after simple rinsing with a cleaning solution, dried and left for a considerable period of time, and then reused. For these purposes, the voids in the nonwoven abrasive articles may constitute at least about 75%, and preferably more, of the total space occupied by the composite structure.

One method of making a nonwoven abrasive article according to the present disclosure includes the following sequential steps: applying a pre-bond coating to the nonwoven web (e.g., by roll coating or spray coating); curing the pre-bond coating; impregnating (e.g., by roll coating or spray coating) the nonwoven web with a make layer precursor that is a curable binder material precursor according to the present disclosure; applying abrasive particles to the make layer precursor; the make layer precursor is at least partially cured, and then optionally a size layer precursor is applied (e.g., as described above), and if desired, the size layer precursor and make layer precursor are cured (e.g., as described above).

More details regarding nonwoven abrasive articles and their methods of manufacture can be found, for example, in U.S. Pat. Nos. 2,958,593(Hoover et al), 4,227,350(Fitzer), 4,991,362(Heyer et al), 5,712,210(Windisch et al), 5,591,239(Edblom et al), 5,681,361(Sanders), 5,858,140(Berger et al); 5,928,070(Lux), and U.S. Pat. No. 6,017,831(Beardsley et al).

In some embodiments, the substrate comprises a fibrous scrim, for example, in the case of a screen abrasive or if included in a bonded abrasive, for example, a cutoff wheel and a hollow grinding wheel. Suitable fibrous scrims may include, for example, woven and knitted fabrics, which may include inorganic fibers and/or organic fibers. For example, the fibers in the scrim may include wires, ceramic fibers, glass fibers (e.g., fiberglass), and organic fibers (e.g., natural organic fibers and/or synthetic organic fibers). Examples of the organic fiber include cotton fiber, jute fiber, and canvas fiber. Examples of synthetic fibers include nylon fibers, rayon fibers, polyester fibers, and polyimide fibers).

Abrasive articles according to the present disclosure may be used, for example, to abrade a workpiece. Such methods may include: abrasive particles according to the present disclosure are brought into frictional contact with a workpiece surface and at least one of the abrasive particles and the workpiece surface are moved relative to the other to abrade at least a portion of the workpiece surface. Methods of abrading with abrasive articles according to the present disclosure include, for example, snagging (i.e., high pressure high stock removal) to polishing (e.g., polishing medical implants with coated abrasive tape), where the latter is typically accomplished with finer grades (e.g., ANSI 220 and finer) of abrasive particles. The size of the abrasive particles for a particular abrading application will be apparent to those skilled in the art.

The milling can be performed dry or wet. For wet milling, the introduced liquid may be provided in the form of a light mist to a full stream of water. Examples of commonly used liquids include: water, water-soluble oils, organic lubricants, and emulsions. These liquids may be used to reduce the heat associated with milling and/or as lubricants. The liquid may contain minor amounts of additives such as biocides, antifoams, etc.

Examples of workpieces include aluminum metal, carbon steel, low carbon steel (e.g., 1018 low carbon steel and 1045 low carbon steel), tool steel, stainless steel, hardened steel, titanium, glass, ceramic, wood-like materials (e.g., plywood and particle board), paint, painted surfaces, and organic-coated surfaces, among others. The force applied during grinding is typically in the range of about 1 to about 100 kilograms (kg), although other pressures may be used.

Selected embodiments of the present disclosure

In a first embodiment, the present disclosure provides a method of making an abrasive article, the method comprising:

disposing a curable composition on a substrate, wherein the curable composition comprises a phenolic resole resin and an organic polymeric rheology modifier, wherein the organic polymeric rheology modifier comprises an alkali-swellable/soluble polymer, and wherein the amount of phenolic resole resin, on a solids basis, comprises 75 wt% to 99.99 wt% of the total weight of phenolic resole resin and organic polymeric rheology modifier;

adhering abrasive particles to the curable composition; and

the curable composition is at least partially cured.

In a second embodiment, the present disclosure provides a method of making an abrasive article according to the first embodiment, wherein the organic polymeric rheology modifier is selected from the group consisting of alkali-swellable/soluble acrylic polymers, hydrophobically-modified ethoxylated urethane polymers, and combinations thereof.

In a third embodiment, the present disclosure provides a method of making an abrasive article according to the first or second embodiment, wherein the amount of resole phenolic resin comprises 85 to 99.99 wt% of the total weight of resole phenolic resin and organic polymeric rheology modifier on a solids basis.

In a fourth embodiment, the present disclosure provides a method of making an abrasive article according to any one of the first to third embodiments, wherein the abrasive particles comprise shaped abrasive particles.

In a fifth embodiment, the present disclosure provides a method of making an abrasive article according to the fourth embodiment, wherein the shaped abrasive particles comprise precisely-shaped abrasive particles.

In a sixth embodiment, the present disclosure provides a method of making an abrasive article according to the fourth embodiment, wherein the shaped abrasive particles comprise precisely-shaped triangular platelets.

In a seventh embodiment, the present disclosure provides a method of making an abrasive article according to any one of the first to sixth embodiments, wherein the substrate comprises a backing member having opposed first and second major surfaces, the method further comprising:

disposing a size layer precursor onto at least a portion of the abrasive particles and the at least partially cured curable composition; and

the size layer precursor is at least partially cured to provide a coated abrasive article.

In an eighth embodiment, the present disclosure provides the method of making an abrasive article according to any one of the first to seventh embodiments, wherein the substrate comprises a lofty, open-celled nonwoven web.

In a ninth embodiment, the present disclosure provides a method of making an abrasive article according to any one of the first to eighth embodiments, wherein the substrate comprises a fibrous scrim.

In a tenth embodiment, the present disclosure provides an abrasive article comprising abrasive particles adhered to a substrate by a binder material comprising an at least partially cured resole phenolic resin and an organic polymeric rheology modifier, wherein the amount of the at least partially cured resole phenolic resin is 75 wt% to 99.99 wt% of the total weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier.

In an eleventh embodiment, the present disclosure provides an abrasive article according to the tenth embodiment, wherein the organic polymeric rheology modifier is selected from the group consisting of alkali-swellable/soluble acrylic polymers, hydrophobically-modified ethoxylated urethane polymers, and combinations thereof.

In a twelfth embodiment, the present disclosure provides an abrasive article according to the tenth or eleventh embodiment, wherein the amount of at least partially cured resole phenolic resin comprises 85 to 99.99 weight percent of the total weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier.

In a thirteenth embodiment, the present disclosure provides the abrasive article of any one of the tenth to twelfth embodiments, wherein the abrasive particles comprise shaped abrasive particles.

In a fourteenth embodiment, the present disclosure provides an abrasive article according to the thirteenth embodiment, wherein the shaped abrasive particles comprise precisely-shaped abrasive particles.

In a fifteenth embodiment, the present disclosure provides an abrasive article according to the thirteenth embodiment, wherein the shaped abrasive particles comprise precisely-shaped triangular platelets.

In a sixteenth embodiment, the present disclosure provides the abrasive article of any one of the tenth to fifteenth embodiments, wherein the abrasive article is a coated abrasive article.

In a seventeenth embodiment, the present disclosure provides the abrasive article of any one of the tenth to sixteenth embodiments, wherein the abrasive article is a nonwoven abrasive article.

In an eighteenth embodiment, the present disclosure provides the abrasive article of any one of the tenth to seventeenth embodiments, wherein the substrate comprises a fibrous scrim.

Objects and advantages of this disclosure are further illustrated by the following non-limiting examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

Examples

All parts, percentages, ratios, and the like in the examples and the remainder of the specification are by weight unless otherwise indicated.

Materials used in the examples

Test method

Viscosity measurement

The upper geometry and as lower geometry and temperature were used equipped with steel 40mm parallel platesTA Instruments Discovery mixing rheometer 3 of TA Instruments Advanced Peltier Plate (APP) of degree control (TA Instruments, New Castle, Delaware) characterizes the flow properties of phenolic copolymer mixtures by continuous flow rheometry. A sample volume of approximately 2 ml was loaded onto APP by pipette and the gap height of the upper plate reached 1050 microns. Excess sample was trimmed off and the exposed edges of the sample were coated with a thin layer of silicone oil (Alfa Aesar, Tewksbury, Massachusetts) having a kinematic viscosity at 25 ℃ of 5.084 × 10^-5m²s^-1) To minimize evaporation of water from the sample. The gap height of the upper plate was then brought to 1000 microns and maintained at this distance during the measurement. Each sample was allowed to thermally equilibrate in the instrument for 180 seconds prior to testing. The shear rate-dependent flow behavior of the mixtures was studied at 25 ℃ in 180 seconds using logarithmic ramps to select 10 individual rates every decade from 0.01 hertz (Hz) to 100 hertz (Hz). The pseudoplastic properties (I) of each sample were determined by measuring the temperature at 0.01s^-1Viscosity measured at 10s^-1The ratio of the measured viscosities. Table 5 shows all the samples tested at 0.01s^-1、10s^-1And viscosity measured under I.

Particle counting

Images of the sample before and after curing were obtained using a MIGOHTY SCOPE 5M digital microscope (Aven Tools, Ann Arbor, Michigan) with circular polarizing filters at a working distance of 8.5cm with an image resolution of 2592 pixels × 1944 pixels. The IMAGEs were then analyzed using IMAGE-PRO PREMIER 64-bit software (Media Cybernetics, inc., Rockville, Maryland, inc.). Regions of the image corresponding to SAP1 are identified digitally by analyzing the image using a red-green-blue (RGB) pixel analysis mode and thresholding the blue channel between 150 and 255 and the green channel between 145 and 250. Regions that touch the edges of the image and regions with an area less than 0.1 square millimeters are excluded from the analysis. The regions were classified according to the ranges in table 1 into four categories, representing single upright particles, two clusters of particles and flat particles, three or more clusters, and fragments of SAP1, respectively, according to the calibration area and aspect ratio. The aspect ratio is defined as the ratio between the major and minor axes of the ellipse equivalent to a particular region.

TABLE 1

Examples 1-14 and comparative examples A-D

According to tables 2-4, examples and comparative examples were prepared by mixing all the components into 4 ounces (120mL)70mm diameter polypropylene straight wall jars (Taral Plastics, Union City, Calif.) and sealing with a screw cap. The jar was mixed in a Double Asymmetric Centrifuge (DAC) speedmixrer (FlackTek inc., Landrum, South Carolina) at 2750rpm for 2 minutes and then allowed to cool to ambient temperature (about 23 ℃). If the mixture was not used immediately for testing, it was stored in a refrigerator at 10 ℃ until use.

TABLE 2

TABLE 3

TABLE 4

Viscosity measurements of examples 1-14 and comparative examples A-D

The samples were tested according to the viscosity measurement test method described above. The results are reported in table 5 below.

TABLE 5

Examples 15-20 and comparative examples E-G

To evaluate the ability of the examples to maintain the orientation of the abrasive particles in the coated abrasive construction, additional examples using resin compositions coated onto backings were prepared. RIO (0.5% based on total resin weight) was added to the formulations of example 1, example 7, example 8, example 11, example 12 and comparative examples A-C to increase the optical contrast between the resin and SAP 1. The sample was mixed in DAC speed mix (flalctek Inc.) at 2750rpm for 1 minute and then allowed to cool to ambient temperature (about 23 ℃). If the mixture is not immediately used for coating, it is stored in a refrigerator at 10 ℃ until use.

Resin was coated onto 8 inch x 4 inch (20.32cm x 10.16cm) segments of a polyester backing (polyester backing described in example 12 of U.S. Pat. No. 6,843,815(Thurber et al)) using stainless steel rods and 3M CIRCUIT PLATING TAPE 851 as spacers to maintain uniformityCoating thickness. The dimensions of the coated sample were approximately 6 inches by 3.5 inches (14.7cm by 8.6 cm). Shaped abrasive particles (SAP1) were transferred in a batch process as described in U.S. patent application publication No. 2016/0311084A1(Culler et al). Shaped abrasive particles are arranged as shown in FIG. 2 of U.S. patent application publication No. 2016/0311084A1(Culler et al). The areal density of SAP1 was measured to be a maximum of 416 particles per square inch (64.5 particles/cm)²)。

After placement of the SAP1, an optical image of a randomly selected area of the coated sample (2.75cm × 2.10cm) was obtained at a working distance of 8.5cm using a MIGHTY SCOPE 5M digital microscope (Aven Tools, Ann Arbor, Michigan) with a circular polarizing filter, with an image resolution of 2592 pixels × 1944 pixels.

The coated sample was then cured in a forced air oven set at 90 ℃ for 60 minutes. After curing, optical images of the three regions that have been previously imaged are obtained. Care was taken to ensure that the same area of each sample was imaged so that the SAP1 orientation before and after curing could be directly compared.

The images of each example and comparative example were performed according to the particle count test method described above. The results are reported in table 6. As can be seen from the data contained in table 6, the formulations with the polymeric rheology control additive have advantages in abrasive particle orientation before and after resin cure. Example 20 shows that above the critical level of additive, the abrasive particles are locked in place once they come into contact with the resin.

TABLE 6

Examples 21 to 23

Preparation Using the primer resin of example 8Coated abrasives examples 21-23. The primer resin was coated onto a single layer polyester backing (the polyester backing described in example 12 of U.S. Pat. No. 6,843,815(Thurber et al)) at 49 deg.C (120 deg.F.) with a gap of 0.2799mm using a 10.2cm hot knife (49 deg.C or 120 deg.F.). The weight of the primer is 163.7g/m². SAP1 was electrostatically coated onto a coated abrasive sample and the mineral weight (314 g/m) was changed as reported in Table 7²、418g/m²、523g/m²). The finished sample had dimensions of approximately 48 inches by 4 inches (121.9cm by 10.2 cm). The tape samples were then cured in a forced air oven at 90 ℃ for 90 minutes and at 103 ℃ for 60 minutes. The tape samples were then coated with the size composition, followed by coating the tape samples with the topcoat composition. A size composition was prepared by charging 431.5g of PF, 227.5g of FIL2, 227.5g of FIL4 and 17g of RIO into a 3 liter (L) plastic container, mechanically mixing, and then diluting with water to a total weight of 1 kg. Then using a 75cm paint roller at 483g/m²Coating rate the prepared size composition was coated on the examples, and the resulting product was cured at 90 ℃ for 60 minutes and then at 102 ℃ for 8 hours. The supersize composition was prepared as described in example 26 of U.S. patent No. 5,441,549 (hellmin) starting from column 21, line 10. Then using a 75cm paint roller at 462g/m²The prepared apex composition was coated onto the examples. The product was cured at 90 ℃ for 30 minutes, at 102 ℃ for 8 hours, and at 109 ℃ for 60 minutes.

Grinding test

Grinding tests were performed on 10.16cm x 91.44cm strips converted from the coated abrasives of examples 21-23. The workpiece was a 304 stainless steel strip, the surface to be abraded measured 1.9cm by 1.9cm, using a 20.3cm diameter 70 durometer rubber, 1:1 matrix groove ratio, saw tooth contact wheel. The belt was run at 2750 rpm. The workpiece is applied to the central portion of the belt with a normal force of 4.4kg to 6.8 kg. The test involves measuring the weight loss of the workpiece after 16 seconds of grinding. The workpiece was then cooled and tested again. The test was terminated after 40 cycles. The initial cut in grams is defined as the total cut after 2 cycles. The total cut in grams is defined as the total cut after 40 cycles. The test results are reported in table 7. Commercially available 984F 36+ I4 Cubitron II tape (3M company) was also tested for comparison and labeled as comparative example H.

TABLE 7

Examples	Weight of mineral, g/m²	Initial cut, g	Total cut, g
				21	314	64.07	886.35
22	418	63.23	917.18
				23	523	47.13	580.19
Comparative example H	-	50.30	578.31

All cited references, patents, and patent applications incorporated by reference in this application are incorporated by reference in a consistent manner. In the event of inconsistencies or contradictions between the incorporated reference parts and the present application, the information in the present application shall prevail. The preceding description, given to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereto.

Claims

1. A method of making an abrasive article, the method comprising:

disposing a curable composition on a substrate, wherein the curable composition comprises a phenolic resole resin and an organic polymeric rheology modifier, wherein the organic polymeric rheology modifier comprises an alkali-swellable/soluble polymer, and wherein the phenolic resole resin is present in an amount from 75 wt% to 99.99 wt% of the total weight of the phenolic resole resin and the organic polymeric rheology modifier, on a solids basis;

adhering abrasive particles to the curable composition; and

at least partially curing the curable composition.

2. The method of claim 1 wherein the organic polymeric rheology modifier is selected from the group consisting of alkali-swellable/soluble acrylic polymers, hydrophobically-modified ethoxylated urethane polymers, and combinations thereof.

3. The method of claim 1, wherein the amount of the phenolic resole resin is 85 to 99.99 wt% on a solids basis based on the total weight of the phenolic resole resin and the organic polymeric rheology modifier.

4. The method of claim 1, wherein the abrasive particles comprise shaped abrasive particles.

5. The method of claim 4, wherein the shaped abrasive particles comprise precisely-shaped abrasive particles.

6. The method of claim 4, wherein the shaped abrasive particles comprise precisely-shaped triangular flakes.

7. The method of claim 1, wherein the substrate comprises a backing member having opposed first and second major surfaces, the method further comprising:

at least partially curing the size layer precursor to provide a coated abrasive article.

8. The method of claim 1 wherein the substrate comprises a lofty, open-celled nonwoven web.

9. The method of claim 1, wherein the substrate comprises a fibrous scrim.

10. An abrasive article comprising abrasive particles adhered to a substrate by a binder material comprising an at least partially cured resole phenolic resin and an organic polymeric rheology modifier, wherein the amount of the at least partially cured resole phenolic resin comprises 75 wt% to 99.99 wt% of the total weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier.

11. The abrasive article of claim 10, wherein the organic polymeric rheology modifier is selected from the group consisting of alkali-swellable/soluble acrylic polymers, hydrophobically-modified ethoxylated urethane polymers, and combinations thereof.

12. The abrasive article of claim 10, wherein the amount of the at least partially cured resole phenolic resin comprises 85 wt% to 99.99 wt% of the total weight of the at least partially cured resole phenolic resin and the organic polymeric rheology modifier.

13. The abrasive article of claim 10, wherein the abrasive particles comprise shaped abrasive particles.

14. The abrasive article of claim 13, wherein the shaped abrasive particles comprise precisely-shaped abrasive particles.

15. The abrasive article of claim 13, wherein the shaped abrasive particles comprise precisely-shaped triangular flakes.

16. The abrasive article of claim 10, wherein the abrasive article is a coated abrasive article.

17. The abrasive article of claim 10, wherein the abrasive article is a nonwoven abrasive article.

18. An abrasive article as defined in claim 10, wherein the substrate comprises a fibrous scrim.