BACKGROUND

Consumer interest in non-scratch scouring/cleaning products for use in home cleaning is increasing due to the desire to protect high-value surfaces that are prone to being damaged if contacted with hard minerals and resins. Consumers are also interested in cleaning products that do not become soiled during the cleaning process. That is, there is interest in cleaning products that either resist soil buildup on the surfaces of the cleaning product or cleaning products that can be rinsed clean of soils after use.

An informal theory of abrasive performance posits that workpiece material removal rate is related to the mechanical properties (i.e., hardness), size, and shape (i.e., sharpness) of the abrasive material. On the other hand, the likelihood of an abrasive material producing scratches on a workpiece is generally discussed in terms of the relative hardness of the abrasive material and the workpiece. Though size and shape affect the geometry of scratches produced by abrasives, forming a scratch requires the deformation of the workpiece by the abrasive material. For this to occur, the abrasive material must be locally stiffer than the workpiece. Thus, provided that the abrasive material is not sufficiently hard so as to deform the workpiece, soils located on the surface of the workpiece having a lower hardness than the workpiece itself can be effectively cleaned by an abrasive material boasting sizes and shapes amenable to high soil removal rates, namely, relatively tall protrusions with relatively sharp edges.

SUMMARY

In one embodiment, the present invention is a structured abrasive article including a substrate having a first major surface and a second major surface, and a plurality of shaped abrasive composites. Each of the shaped abrasive composites includes a bottom surface in contact with the first major surface of the substrate. Each of the bottom surfaces takes the shape of a concave polygon and each of the concave polygons has a convex hull having n sides.

In another embodiment, the present invention is a structured abrasive article including a substrate having a first major surface and a second major surface, and at least one shaped abrasive composite having a bottom surface. The bottom surface of the at least one shaped abrasive composite is positioned on the first major surface of the substrate and has at least one internal concave angle. In yet another embodiment, the present invention is a shaped abrasive composite including a binder phase and a particulate grain phase dispersed within the binder phase. The shaped abrasive composite has at least one internal concave angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-11 show the configurations of shaped abrasive composites according to various exemplary embodiments.

DESCRIPTION OF THE INVENTION

The present invention is an abrasive composite designed, through geometry and composition, to have high scouring performance without producing appreciable damage to the underlying substrate being cleaned. In one embodiment, the abrasive composite can be used for home cleaning that results in substantially no or minimal damage to materials such as, for example, poly(tetrafluoroethylene), stainless steel, and hard plastics. After being used to clean, the abrasive composite can be essentially rinsed clean of debris removed from the surfaces being cleaned. In addition, the abrasive composite of the present invention is durable and wears well.

The abrasive composite of the present invention is formed from dispersing a mineral or particulate grain phase in an organic binder phase. In the abrasive composite, particulate grains are bound together by a binder that serves both as a dispersing medium for the particulate grains and as a means of attaching the abrasive composites to a substrate or backing, if desired. The particulate grains primarily act as a filler and viscosity modifier in the uncured liquid binder. By contrast, the particulate grains of traditionally coated or nonwoven abrasives generally have high Mohs hardness values and can remove a significant amount of material from a surface contacted by the particulate grains through a plowing or cutting mechanism. The amount of material removed is dependent on the shape, hardness, and size of the particle grain, as well as the pressure, speed, and geometry of the abrading operation. In this application, gouges formed on a surface from removed material are framed as "scratches". While individual particulate grains with a low Mohs hardness value (i.e., less than or equal to about 3) may not produce a visible scratch on a test surface, the particulate grains can affect scratching by modifying the mechanical properties of the composite in accordance with general mixing rules for composites. In one embodiment, the abrasive composites of the present invention contain particulate grains having a Mohs hardness of less than or equal to about 3.

While an abrasive compositive having a higher Mohs hardness, or higher modulus, generally results in higher cleaning performance, it also results in an increased amount of surface damage or scratches. Conversely, while an abrasive compositive having a lower modulus generally aids in avoiding surface damages or scratches, it also lowers the cleaning performance of the abrasive composite. At a given temperature, a similar correlation between scouring/scratching and glass transition temperature (Tg) of the binder resin can also be empirically observed. By using a miscible blend of soft and hard binder components, the modulus and glass transition temperature of the binder mixture can be tuned to optimize the balance of cleaning performance and surface damage, avoiding the more costly molecular engineering required to synthesize a single material having the desired glass transition temperature and modulus.

Examples of particulate grains having a Mohs hardness of less than about 3 include, but are not limited to: clays (such as kaolinite, montmorillonite, illite, chlorite clays, talc, soapstone), gypsum, calcium carbonate (such as limestone and marble), mica, halite, and jet. Additionally, numerous soft organic materials can provide the same functions as soft particulate mineral grains, such as crushed or ground shells of nuts/fruits including, but not limited to: almond, argan, coconut, hazelnut, macadamia, pecan, pine, pistachio, and walnut; crushed or ground pits/kemels of fruits including, but not limited to: apricot, olive, peach, cherry, plum, palm, and tagua; crushed or ground com cob; crushed or ground shells of arthropods; wood flour; crushed or ground synthetic polymeric materials including, but not limited to, any thermoplastic polymer or any thermoset polymer; and crushed, ground, or unmodified naturally -derived polymeric materials including, but not limited to, polyhydroxyalkanoates; precision-shaped synthetic polymeric materials. In one embodiment, the abrasive composite includes more than one type of particulate grain. In one embodiment, the abrasive composite includes between about 26% and about 80%, particularly between about 47% and about 75%, and more particularly between about 58% and about 72% by weight particulate grains.

The binder of the abrasive composite must be capable of providing a medium in which the particulate grains can be distributed. The binder generally includes a soft crosslinkable binder component, a hard cross-linkable binder component, and a material that is capable of initiating addition polymerization. The soft cross-linkable binder component, when polymerized, has a glass transition temperature below room temperature (thereby being rubbery and capable of deformation) and a modulus of less than about 150 MPa. In one embodiment, the soft cross-linkable binder component includes a urethane diacrylate or triacrylate. An example of a suitable soft cross-linkable binder component includes, but is not limited to, an aliphatic urethane diacrylate. In one embodiment, the soft cross-linkable binder component, when polymerized, has an elongation % at break of greater than about 25%. The hard cross-linkable binder component has a glass transition temperature above room temperature (thereby being glassy and stiff). In one embodiment, the hard cross- linkable binder component includes a difunctional or trifunctional acrylate. Examples of suitable hard cross-linkable binder components include, but are not limited to: trimethylolpropane triacrylate, 1,6 -hexanediol diacrylate, and pentaerythritol tetraacrylate.

In one embodiment, the binder is capable of being cured or gelled relatively quickly so that the abrasive composite can be quickly fabricated. Some binders gel relatively quickly but require a longer time to fully cure. Gelling preserves the shape of the composite until curing commences. Fast curing or fast gelling binders can result in coated abrasive articles having abrasive composites of high consistency. Examples of binders suitable for the present invention include, but are not limited to: thermoplastic resins, phenolic resins, aminoplast resins, urethane resins, epoxy resins, acrylate resins, acrylated isocyanurate resins, urea formaldehyde resins, isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, hot melt glue, and mixtures thereof.

Depending on the binder used, curing or gelling can be carried out by an energy source known by one of skill in the art. The energy source may include, but is not limited to: heat, infrared irradiation, electron beam, ultraviolet radiation, or visible radiation. A radiation-curable binder is any binder that can be at least partially cured or at least partially polymerized by radiation energy. Typically, these binders polymerize via a free radical mechanism.

If the binder is cured by ultraviolet radiation, a photoinitiator is required to initiate free radical polymerization. Examples of photoinitiators include, but are not limited to: organic peroxides, azo compounds, quinones, benzophenones, nitroso compounds, acryl halides, hydrazones, mercapto compounds, pyrylium compounds, triacrylimidazoles, bisimidazoles, chloralkyltriazines, benzil ketals, thioxanthones, and acetophenone derivatives. Other examples include, but are not limited to: benzoin and its derivatives such as alpha-methylbenzoin; alphaphenylbenzoin; alpha-allylbenzoin; alphabenzylbenzoin; benzoin ethers such as benzil dimethyl ketal (e.g., as commercially available as IRGACURE 651 from Ciba Specialty Chemicals, Tarrytown, N.Y.), benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether; acetophenone and its derivatives such as 2-hydroxy-2-methyl- 1-phenyl-l- propanone (e.g., as DAROCUR 1173 from Ciba Specialty Chemicals) and 1 -hydroxy cyclohexyl phenyl ketone (e.g., as IRGACURE 184 from Ciba Specialty Chemicals); 2-methyl- l-[4-(methylthio)phenyl] -2-(4-morpholinyl)-l- propanone (e.g., as IRGACURE 907 from Ciba Specialty Chemicals; 2-benzyl-2- (dimethylamino)-l-[4-(4-morpholinyl)phenyl] -1-butanone (e.g., as IRGACURE 369 from Ciba Specialty Chemicals). Other examples include phosphorus-containing organic molecules, such as bis(2,4,6- trimethylbenzoyl)-phenylphosphineoxide (e.g. IRGACURE 819 from Ciba Specialty Chemicals) and ethyl (2,4,6-trimethylbenzoyl) phenyl phosphinate (e.g. TPO-L from Ciba Specialty Chemicals). Still more useful photoinitiators include, for example, pivaloin ethyl ether, anisoin ethyl ether, anthraquinones (e.g., anthraquinone, 2-ethylanthraquinone, 1- chloroanthraquinone, 1,4-dimethylanthraquinone, 1- methoxyanthraquinone, or benzanthraquinone), halomethyltriazines, benzophenone and its derivatives, iodonium salts and sulfonium salts, titanium complexes such as bis(eta5- 2,4-cyclopentadien-l-yl)-bis[2,6-difluoro- 3(1 H-pyrrol-l-yl)phenyl]titanium (e.g., as CGI 784DC from Ciba Specialty Chemicals); and halonitrobenzenes (e.g., 4- bromomethylnitrobenzene), mono- and bis-acylphosphines (e.g., as IRGACURE 1700, IRGACURE 1800, IRGACURE 1850, and DAROCUR 4265 all from Ciba Specialty Chemicals). In one embodiment, more than one photoinitiator is used.

One or more spectral sensitizers (e.g., dyes) may be used in conjunction with the photoinitiator(s) to, for example, increase sensitivity of the photoinitiator to a specific source of actinic radiation. In one embodiment, the abrasive composite includes between about 15% and about 35%, particularly between about 16% and about 28%, and more particularly between about 18% and about 26% by weight soft cross-linkable binder component. In one embodiment, the abrasive composite includes between about 8% and about 28%, particularly between about 10% and about 15%, and more particularly between about 11% and about 14% by weight hard crosslinkable binder component. In one embodiment, the abrasive composite includes between about 0.5% and about 5%, particularly between about 0.6% and about 1%, and more particularly between about 0.7% and about 0.9% by weight material capable of initiating addition polymerization.

The binder may be radiation-curable through an addition polymerization mechanism. To promote an association bridge between the binder and the particulate grains, a silane coupling agent may be included in the slurry of particulate grains and binder precursor. In one embodiment, the silane coupling agent may be present in an amount up to about 1%, particularly between about 0.05% and about 0.4% by weight, and more particularly between about 0.1% and about 0.3% by weight. However, one of skill in the art will know that other amounts may also be used, depending, for example, on the size of the minerals. Suitable silane coupling agents include, but are not limited to: methacryloxypropylsilane, vinyltriethoxysilane, vinyltris(2- methoxyethoxyjsilane, 3,4- epoxycyclohexylmethyltrimethoxysilane, gammaglycidoxypropyl- trimethoxy silane, and gamma-mercaptopropyltrimethoxysilane (e.g., as available under the respective trade designations A- 174, A- 151, A-172, A-186, A-187, and A-189 from Witco Corp, of Greenwich, Conn.), allyltriethoxysilane, diallyldichlorosilane, divinyldiethoxysilane, and meta, para-styrylethyl-trimethoxysilane (e.g., as commercially available under the respective trade designations A0564, D4050, D6205, and S1588 from United Chemical Industries, Bristol, Pa.), dimethyldiethoxy silane, dihydroxydiphenylsilane, triethoxysilane, trimethoxysilane, tri ethoxy silanol, 3 -(2 -aminoethylamino) propyltrimethoxysilane, methyltrimethoxysilane, vinyltriacetoxysilane, methyltriethoxysilane, tetraethyl orthosilicate, tetramethyl orthosilicate, ethyltriethoxysilane, amyltriethoxy silane, ethyltrichlorosilane, amyltrichlorosilane, phenyltrichlorosilane, phenyltriethoxysilane, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, dimethyldiethoxy silane, and mixtures thereof.

Other materials can be added to the abrasive composite for special purposes including, but not limited to: monofunctional acrylic monomers, thermal free radical initiators, accelerators, polymer waxes or beads, leveling agents, wetting agents, matting agents, colorants, dyes, pigments, slip agents, adhesion promoters, fillers, rheology modifiers, thixotropic agents, plasticizers, UV absorbers, UV stabilizing agents, dispersants, antioxidants, antistatic agents, lubricants, opacifying agents, anti-foam agents, antimicrobial agents, fungicides, and combinations thereof. In one embodiment, the additives are organic. In one embodiment, the abrasive composite includes up to about 2%, particularly between about 0.1% and about 1.8%, and more particularly between about 0.8% and about 1.4% by weight dispersant. In one embodiment, the abrasive composite includes up to about 1%, particularly between about 0.05% and about 0.4%, and more particularly between about 0.1% and about 0.3% by weight coupling agent. In one embodiment, the abrasive composite includes up to about 1%, particularly up to about 0.5%, and more particularly up to about 0.3% by weight colorant. In one particular embodiment, the abrasive composite includes between about 0.5% and about 5%, particularly between about 0.6% and about 1%, and more particularly between about 0.8% by weight photoinitiator; between about 25% and about 55%, particularly between about 35% and about 45%; and more particularly between about 38% and about 42% by weight of a first particulate grain; and between about 1% and about 30%, particularly between about 12% and about 25%, and more particularly between about 16% and about 24% by weight of a second particulate grain. While the abrasive composite includes a binder phase and a mineral phase, the mineral phase is not believed to contribute directly to the scouring ability of the abrasive composite and functions more as a filler due to its relative softness and small size. Rather, the scouring performance arises from the properties of the combination of the binder phase and the mineral phase as a whole.

In one embodiment, the abrasive composites of the present invention are used to form a structured abrasive article including a plurality of substantially identically shaped abrasive composites attached to a substrate. "Shaped abrasive composite", as used herein, refers to abrasive composites having a shape engineered through experimentation to have superior scouring performance and durability. In one embodiment, the engineered shape can be formed by curing one or more binder components of a flowable mixture also containing soft mineral grains while the mixture is both being borne on a backing and filling a cavity on the surface of a production tool. Such shaped abrasive composites have a substantially identical shape to that of the inverse of the cavity. In one embodiment, the shaped abrasive composites can be pyramidal, the dimensions of which are substantially identical across all of the composite features.

The shaped abrasive composite of the present invention includes an in-plane geometry having a concave angle. This shape is also referred to herein as a concave or re-entrant polygon. That is, the shaped abrasive article has at least one internal angle that is between 180° and 360°. The concave polygon has a convex hull having n sides. In one embodiment, n is at least 3. The scouring performance of the abrasive composite of the present invention having an internal concave angle is greater than the scouring performance of a comparative abrasive composite having only internal convex angles, or internal angles of less than 180°. An abrasive composite having only convex internal angles is also referred to herein as a convex polygon. Depictions of exemplary concave polygons and exemplary convex polygons are shown in FIGS. 1 and 2.

The abrasive composite of the present invention includes a bottom surface and one or more top surfaces. The bottom surface forms the shape of the concave polygon of the abrasive composite and has between 1 and n vertices with concave internal angles. Increasing the number of vertices and sides of the abrasive composite can result in a decrease in scouring performance. Without being bound by theory, generally, as the number of sides increases, the bearing area of the pattern increases as well, lowering the pressure on each individual side, decreasing its ability to cut through soils. In one embodiment, the longest diagonal of the polygon of the bottom surface is between about 0.3mm and about 6mm long.

The top surface of the abrasive composite may include a single face or a plurality of faces. The top surface can be defined as a point, line, or plane. In one embodiment, the top surface of the abrasive composite can be flattened. Flattening the top surface may soften the tactile perception of the shaped features.

In one embodiment, the bottom surface has the shape of a star polygon, and particularly a regular star polygon. Top and side views of a four-point star polygon are shown in FIGS. 3 and 4.

In one embodiment, the features may have zero planes of symmetry. In one embodiment, one of more of the top surfaces may contact, or intersect, the bottom surface. An example of an embodiment in which the abrasive composite has zero planes of symmetry and has a top surface which intersects the bottom surface is shown in FIG. 5. As can be seen in this figure, the abrasive composite does not need to be a regular polygon.

The shaped abrasive composites and structured abrasive articles having shaped abrasive composites can be formed by production tools. A production tool has a surface defining a main plane, which contains a plurality of cavities distending as indentations from the main plane. These cavities define the inverse shape of the abrasive composite and are responsible for generating the shape, size, and placement of the abrasive composites. The cavities can be provided in essentially any geometric shape that is the inverse of a geometric shape which is suitable for an abrasive composite. For example, the abrasive composites may be cubic, cylindrical, prismatic, hemispheric, rectangular, pyramidal, truncated pyramidal, conical, truncated conical, or post-like. The patterns in which the cavities are arranged are selected to balance scouring performance, visual aesthetics, haptic perception of individual composite features, and consumption of composite precursor.

The production tool can take the form of a belt, sheet, continuous sheet or web, coating roll such as a rotogravure roll, sleeve mounted on a coating roll, or die. In one embodiment, the production tool is replicated from a master tool. The master tool can be fabricated by any conventional technique known to those of skill in the art, including but not limited to: photolithography, knurling, engraving, hobbing, electroforming, and diamond turning. U.S. Patent No. 5,851,247 (Stoetzel et al.) describes a production tool made of thermoplastic material that can be replicated from a master tool and is hereby incorporated by reference. When a production tool is replicated from a master tool, the master tool is provided with the inverse of the pattern which is desired for the production tool. In one embodiment, the master tool is made of a nickel-plated metal, such as nickel-plated aluminum, nickel-plated copper, or nickel-plated bronze. A production tool can be replicated from a master tool by pressing a sheet of thermoplastic material against the master tool while heating the master tool and/or the thermoplastic sheet such that the thermoplastic material is embossed with the master tool pattern. Alternatively, the thermoplastic material can be extruded or cast directly onto the master tool. The thermoplastic material is then cooled to a solid state and is separated from the master tool to produce a production tool. The production tool may optionally contain a release coating to permit easier release of the abrasive article. Examples of suitable release coatings include but are not limited to: silicones and fluorochemicals. Preferred methods for the production of production tools are disclosed in U.S. Pat. Nos. 5,435,816 (Spurgeon et al.), 5,658,184 (Hoopman et al.), and in U.S. Ser. No. 08/923, 862, "Method and Apparatus for Knurling a Workpiece, Method of Molding an Article with Such Workpiece, and Such Molded Article" (Hoopman), filed Sep. 3, 1997), the disclosures of which are incorporated herein by reference.

In one embodiment, the structured abrasive article can be made by first introducing a flowable and curable slurry containing a mixture of a binder precursor and a plurality of minerals into cavities contained on an outer surface of a production tool to fill the cavities. A substrate having a first major surface and second, opposite, major surface is then introduced to the outer surface of the production tool over the filled cavities such that the slurry wets one major surface of the substrate to form an intermediate article. The binder is then cured before the intermediate article departs from the outer surface of the production tool to form a shaped-composite-coated abrasive article. The structured abrasive article is then removed from the surface of the production tool. In another embodiment, the abrasive article can be made by first introducing a flowable and curable slurry containing a mixture of a binder precursor and plurality of minerals onto a front side of a substrate such that the slurry wets the front side of the substrate to form an intermediate article. The slurry is then introduced to the bearing side of the intermediate article to an outer surface of a production tool having a plurality of cavities in its outer surface such that the cavities are filled. The binder precursor is then cured before the intermediate article departs from the outer surface of the production tool to form a shaped-composite-coated abrasive article. The abrasive article is then removed from the surface of the production tool. In both of the methods described, in one embodiment, the steps are carried out in a continuous manner, providing an efficient method of making the structured abrasive article of the present invention.

When forming a structured abrasive article, the plurality of shaped abrasive composites is attached to at least one major surface of a substrate. The shaped abrasive composites provide three-dimensional shapes that project outwardly from a surface of the substrate. The abrasive composites can be disposed on the substrate in either a pattern (i.e., non-random array) or a disordered or random array. In one embodiment, the abrasive composites are disposed on the substrate in a non-random array that exhibits some degree of repetitiveness.

Materials suitable for the substrate of the present invention include, but are not limited to: polymeric film, paper, cloth, metallic film, vulcanized fiber, nonwoven substrates, combinations thereof, and chemically treated versions thereof. In one embodiment, the substrate is a polymeric film, such as polyester or polyurethane film. In one embodiment, the substrate is transparent to ultraviolet radiation. In one embodiment, the substrate is coated with an adhesion-promoting layer, such as poly(ethylene-co- acrylic acid) or a UV-curable "tie coat" layer, or undergo adhesion-promoting surface modification, such as corona or flame treatment or electron beam irradiation. The substrate can be laminated to another substrate after the abrasive article is formed. For example, the substrate can be laminated to a flexible or stiff polyurethane foam material, providing a means for effective manipulation of the abrasive by the user.

EXAMPLES

The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those skilled in the art. Unless otherwise noted, all parts, percentages, and ratios reported in the following examples are on a weight basis. Where applicable, brand names and trademarked names are shown in all caps. Table 1: List of materials

The formulas of Examples 1-8 are listed below in Table 2. Table 2: List of formulas for example structured abrasive articles

Test Methods

Schiefer Cut Text

To evaluate the relative abrasiveness of articles of the present invention, articles tested were cut into circular samples approximately 4.5 centimeters in diameter. The articles were secured to the drive plate of a Schiefer Abrasion Tester (available from Frasier Precision Company of Gaithersburg, Maryland) using a plastic bristle fastener available under the trade designation "INSTA-LOK" from the Minnesota Mining and Manufacturing Company. Circular acrylic workpieces (available under the trade designation "ACRYLITE" from American Cyanamid Co.) were employed for each of the articles tested. The workpieces were all approximately 10.16 cm in diameter and about 0.317 cm thick. The initial dry weight of each workpiece was recorded, and the workpiece was secured to the lower turntable of the test machine using double sided foam tape. Testing was conducted under a load of 2.26 kg for 5,000 revolutions with water applied to the surface of the acrylic disc at a rate of 40-60 drops/minute. The final weight of the workpiece was then determined and the weight loss by the acrylic disc during the test is given as the result (reported as grams per 5,000 revolutions). Foodsoil Removal Test

To determine the initial effectiveness of the scouring articles at removing carbonized foodsoil from a stainless steel disc (10.16 cm diameter x 0.31 cm thick), a measured amount of a blended foodsoil composition was coated onto a stainless steel disc and baked for thirty minutes at 232° C. The blended foodsoil composition included about 120 g tomato juice, about 120 g cherry juice, about 120 g ground beef (70% lean), about 60 g shredded Cheddar cheese, about 120 g whole milk, about 20 g white all-purpose flour, about 100 g granulated sugar, and 1 Grade AA egg. The disc was alternately coated and baked three times, weighed and then attached to the lower turntable of a Schiefer Abrasion Tester modified to accommodate the disc. A 2.26 kg (5 lb) head weight was used as the applied force. The 4.5 cm diameter sample tested was saturated with water, centered, and fastened against the upper turntable of the test machine and tested for 50 cycles under wet conditions by lubricating the disc with water at a rate of 1 drop/second. The dry weight of the disc (in milligrams) was determined after the desired number of revolutions and the weight loss was reported for the dried disc.

Figure of Merit

The figure of merit is used to compare the scouring performance to substrate damage and obtained by dividing the output of the foodsoil removal test (in mg per 50 cycles) by the output of the Schiefer Cut Test (in g per 5000 cycles).

COMPARISON TO OTHER SCOURING PRODUCTS

The average food soil removed (based on the Foodsoil Removal Test), average acrylic cut (based on the Schiefer Cut Test), and ratio of food soil removed to acrylic cut (Figure of Merit) for Examples 1 and 2, both having a 4-point star shape, and Abrasive Laminates 1 and 2 are shown below in Table 3.

Table 3: Comparison of Food Soil Removal and Acrylic Cut of two formulas to standard _ home care products. _

Pattern/product Composition Average Average Ratio of foodsoil foodsoil acrylic cut removed (mg) to acrylic removed (mg) (g) cut (g)

4-point star EX2 7.0 0.14 51.0

4-point star EXI 1.7 0.02 87.5

Abrasive NA 5.9 2.95 2.0

Laminate 1

Abrasive NA 2.0 1.14 1.8

Laminate 2 As can be seen above in Table 3, the articles of Examples 1 and 2, which included shaped scouring features, vastly outperformed conventional Heavy-Duty Scotch-Brite® products, meaning that they displayed greater selectivity for removing soils over the hard underlying surfaces, i.e. excellent scouring behavior with little to no surface damage. Thus, it is concluded that the feature shape(s) of the abrasive article has a surprisingly important effect on foodsoil removal performance.

Table 4: Food soil removal and coat weight based on abrasive article pattern

% Foodsoil removed per

Feature type Composition % Foodsoil Coat Weight coat weight removed (g/m2)

Hex 2 49.4 169 0.29

Dot 2 48.0 187 0.26

Four-Pointed 2 70.5 84 0.84

Star (FPS)

The “Hex,” “Dot,” and “FPS” patterns are shown in FIGS. 6, 7, and 8, respectively. As can be seen in Table 4, a pattern featuring Four-Point Star (FPS) features, despite having about 50% lower composite coat weight than the "Hex" or "Dot" patterns, removed about 44% more foodsoil. Unlike the features in the "Hex" and "Dot" patterns, FPS features are concave polygons, meaning that they have at least one interior angle measuring 180° < 8 <360°. Such geometry creates sharp, plow-like exposed edges that likely contribute to the higher performance.

In one embodiment, the shaped features of the abrasive articles can be substantially flattened. Foodsoil removal results for three-point star (TPS), four-point star (FPS), and six- point star (SPS) abrasive composites made from the composition of Example 2 and having features with such modifications are shown in Table 5 below. Exemplary depictions of TPS, FPS, and SPS abrasive composites having pointed and flattened top surfaces are shown in FIGS. 9-11, respectively.

Table 5. Foodsoil removal

As can be seen in Table 5, flatening the top surface results in a significant decrease in scouring performance over the length of the test. This indicates that a relatively sharp top surface plays relatively substantial a role in scouring performance.

EFFECT OF ABRASIVE MINERAL ON PERFORMANCE

An unexpected aspect of the performance of the shaped scouring features of the present invention is the relative lack of importance of the size and concentration of the abrasive mineral used in the mineral or particulate grain phase. In the examples below, aluminum oxide is used as the mineral in the abrasive composite formulation of hexagonal scouring features. The results are shown in Table 6, and are contrary to those of industrial abrasive products, where the effects of abrasive particle size and concentration are readily identified.

Table 6: Effect of AI2O3 particle size and loading on food soil removal performance of "Hex" pyramid scouring features

The lack of effect of aluminum oxide illuminates important mechanistic differences between engineered abrasive features used in home cleaning and those used in industrial applications and gives valuable insight into designing scouring formulations. In industry, abrasives are generally used with hand-held or stationary power tools capable of delivering much greater pressures and much higher speeds than the human arm or a Schieffer machine. When high pressures and speeds are used, the engineered abrasive features break down (through wear and fracture) much more quickly, thereby constantly exposing new abrasive mineral. However, when the abrasives are used by hand or on Schieffer machines (i.e. at lower pressures and speeds), the abrasive composites generally do not fracture, and wear slowly. Therefore, contrary to abrasives for industrial purposes, the abrasive performance of scouring products for home cleaning, in instances where abrasive mineral particles are not located on the surface of the product, arises from the mechanical properties of the composite as a whole, as opposed to arising from individual abrasive particles.