Non-scratch polishing composite and polished and cleaned article

Abstract

The present invention is a structured polishing article including a substrate having a first major surface and a second major surface, and a plurality of shaped polishing composites. Each of the shaped polishing composites has a bottom surface that contacts the first major surface of the substrate. Each of the bottom surfaces has a concave polygon shape, and each of the concave polygons has a convex hull having n sides.

Description

Background Art

[0001] Consumer interest in non-scratch polishing / cleaning products for household cleaning is increasing due to the desire to protect high-value surfaces that are easily damaged when contacting hard minerals and resins. Consumers are also interested in cleaning products that do not get dirty during the cleaning process. That is, they are interested in cleaning products where dirt does not easily accumulate on the surface of the cleaning product, or where dirt can be easily washed away after use.

[0002] Unofficial theories of polishing performance assume that the removal rate of the workpiece is related to the mechanical properties (i.e., hardness), size, and shape (i.e., sharpness) of the abrasive. On the other hand, the possibility of the abrasive scratching the workpiece is generally discussed in terms of the relative hardness of the abrasive and the workpiece. Size and shape affect the shape of the scratches produced by the abrasive, but deformation of the workpiece by the abrasive is required to form a scratch. For this to occur, the abrasive must be locally harder than the workpiece. Thus, if the abrasive is not hard enough to deform the workpiece, dirt on the surface of the workpiece that is softer than the workpiece itself can be effectively cleaned by an abrasive having a size and shape suitable for a high dirt removal rate, i.e., an abrasive having relatively high protrusions and relatively sharp edges.

Summary of the Invention

[0003] In one embodiment, the present invention is a structured polishing article including a substrate having a first major surface and a second major surface, and a plurality of shaped polishing composites. Each of the shaped polishing composites has a bottom surface that contacts the first major surface of the substrate. Each of the bottom surfaces has a concave polygonal shape, and each of the concave polygons has a convex hull having n sides.

[0004] In another embodiment, the present invention is a structured polishing article comprising a substrate having a first major surface and a second major surface, and at least one shaped polishing composite having a bottom surface. The bottom surface of the at least one shaped polishing composite is disposed on the first major surface of the substrate and has at least one concave inner corner.

[0005] In yet another embodiment, the present invention is a shaped polishing composite comprising a binder phase and a particulate grain phase dispersed within the binder phase. The shaped polishing composite has at least one concave inner corner.

Brief Description of the Drawings

[0006]

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Modes for Carrying Out the Invention

[0007] The present invention is an abrasive composite designed by geometry and composition to have high scouring performance without imparting visible damage to the substrate to be cleaned. In certain embodiments, the abrasive composite can be used for household cleaning with substantially no damage or minimal damage to materials such as poly(tetrafluoroethylene), stainless steel, and hard plastics. After being used for cleaning, the abrasive composite can wash away the debris removed from the surface to be cleaned almost cleanly. Further, the abrasive composite of the present invention is durable and resistant to wear.

[0008] The abrasive composite of the present invention is formed by dispersing a mineral or particulate granular phase in an organic binder phase. In the abrasive composite, optionally, the particulate grains are bonded by the binder, and the binder functions as a dispersion medium for the particulate grains and as a means for attaching the abrasive composite to a substrate or support. The particulate grains mainly function as fillers and viscosity modifiers in the uncured liquid binder. In contrast, the particulate grains of conventional coated or non-woven abrasives generally have a high Mohs hardness value and can remove a significant amount of material from the surface contacted by the particulate grains through a plowing or cutting mechanism. The amount of material removed depends on the shape, hardness, and size of the particle grains, as well as the pressure, speed, and geometry of the polishing operation. In this application, the grooves on the surface formed from the removed material are expressed as "scratches". Individual particulate grains with a low Mohs hardness value (i.e., about 3 or less) may not produce visible scratches on the test surface, but the particulate grains can affect the scratches by changing the mechanical properties of the composite according to the general mixing rules of the composite. In certain embodiments, the abrasive composite of the present invention includes particulate grains with a Mohs hardness of about 3 or less.

[0009] A polishing composite with a high Mohs hardness or a high elastic modulus generally provides high cleaning performance, but at the same time increases the amount of surface damage and scratches. Conversely, a polishing composite with a low elastic modulus helps to avoid surface damage and scratches, but also reduces the cleaning performance of the polishing composite. At a specific temperature, a similar correlation can also be empirically observed between the scuffing / scratches and the glass transition temperature (Tg) of the binder resin. By using a miscible blend of a soft binder component and a hard binder component, the elastic modulus and the glass transition temperature of the binder mixture can be adjusted to optimize the balance between cleaning performance and surface damage, and avoid the more costly molecular design required to synthesize a single material with the desired glass transition temperature and elastic modulus.

[0010] Examples of particulate grains with a Mohs hardness of less than about 3 include, but are not limited to, clay (kaolinite, montmorillonite, illite, chlorite clay, talc, soapstone), gypsum, calcium carbonate (limestone and marble), mica, rock salt, jet, etc. Furthermore, many soft organic materials can provide the same function as soft particulate mineral grains, for example, ground or milled nut / fruit shells such as almond, argan, coconut, hazelnut, macadamia, pecan, pine, pistachio, walnut, etc. (but not limited to these); ground or milled seeds / nuts of fruits such as apricot, olive, peach, cherry, plum, palm, tagua, etc. (but not limited to these); ground or milled corn cobs; ground or milled arthropod shells; wood flour; ground or milled synthetic polymer materials including, but not limited to, any thermoplastic polymer or any thermosetting polymer; and ground, milled, or unmodified natural-derived polymer materials including, but not limited to, polyhydroxyalkanoates; precision-molded synthetic polymer materials, etc. are included. In certain embodiments, the polishing composite includes multiple types of particulate grains. In certain embodiments, the polishing composite includes particulate grains in a weight ratio of from about 26% to about 80%, particularly from about 47% to about 75%, and even more particularly from about 58% to about 72%.

[0011] The binder of the abrasive composite needs to be able to provide a medium in which particulate grains can be dispersed therein. The binder generally includes a soft crosslinkable binder component, a hard crosslinkable binder component, and a material capable of initiating addition polymerization. The soft crosslinkable binder component, when polymerized, has a glass transition temperature below room temperature (and thus is rubbery and deformable), and has an elastic modulus of less than about 150 MPa. In certain embodiments, the soft crosslinkable binder component includes urethane diacrylate or triacrylate. Examples of suitable soft crosslinkable binder components include, but are not limited to, aliphatic urethane diacrylate. In certain embodiments, the soft crosslinkable binder component, when polymerized, has an elongation at break of greater than about 25%. The hard crosslinkable binder component has a glass transition temperature above room temperature (and thus is glassy and hard). In certain embodiments, the hard crosslinkable binder component includes a difunctional or trifunctional acrylate. Examples of suitable hard crosslinkable binder components include, but are not limited to, trimethylolpropane triacrylate, 1,6 - hexanediol diacrylate, and pentaerythritol tetraacrylate.

[0012] In certain embodiments, the binder can cure or gel relatively rapidly, allowing for the rapid production of the abrasive composite. Some binders gel relatively rapidly but take a long time to fully cure. Gelation holds the shape of the composite until curing is initiated. A binder that cures or gels rapidly can result in a coated abrasive article having an abrasive composite with 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 adhesives, and mixtures thereof.

[0013] Depending on the binder used, curing or gelling can be carried out by an energy source known to those skilled in the art. The energy source includes, but is not limited to, heat, infrared irradiation, electron beam, ultraviolet radiation, or visible light radiation. A radiation curable binder is a binder that can be at least partially cured or at least partially polymerized by radiation energy. Usually, these binders polymerize via a free radical mechanism.

[0014] When 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, triacrylimidazole, bisimidazole, chloroalkyltriazine, benzyl ketal, thioxanthone, and acetophenone derivatives. Other examples include benzoin and its derivatives (e.g., α-methylbenzoin, α-phenylbenzoin, α-allylbenzoin, α-benzylbenzoin); benzoin ethers (e.g., benzyldimethyl ketal (commercially available as IRGACURE 651 from Ciba Specialty Chemicals, Tarrytown, NY), benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether); acetophenone and its derivatives (e.g., 2-hydroxy-2-methyl-1-phenyl-1-propanone (commercially available as DAROCUR 1173 from Ciba Specialty Chemicals) and 1-hydroxycyclohexyl phenyl ketone (commercially available as IRGACURE 184 from Ciba Specialty Chemicals)); 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (commercially available as IRGACURE 907 from Ciba Specialty Chemicals); 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone (commercially available as IRGACURE 369 from Ciba Specialty Chemicals). Other examples include phosphorus-containing organic molecules (e.g., bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (commercially available as IRGACURE 819 from Ciba Specialty Chemicals) and ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (commercially available as TPO-L from Ciba Specialty Chemicals)).Further useful photoinitiators include 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 (e.g., bis(η5-2,4-cyclopentadien-1-yl)-bis[2,6-difluoro-3(1H-pyrrol-1-yl)phenyl]titanium, available as CGI 784DC from Ciba Specialty Chemicals); and halonitrobenzenes (e.g., 4-bromomethylnitrobenzene), mono- and bisacylphosphines (e.g., available as IRGACURE 1700, IRGACURE 1800, IRGACURE 1850, and DAROCUR 4265 from Ciba Specialty Chemicals). In certain embodiments, a plurality of photoinitiators are used.

[0015] One or more spectral sensitizers (e.g., dyes) may be used in combination with the photoinitiator, for example, to increase the sensitivity of the photoinitiator to a particular actinic radiation source. In certain embodiments, the polishing composite comprises from about 15% to about 35%, particularly from about 16% to about 28%, and more particularly from about 18% to about 26% by weight of a soft crosslinkable binder component. In certain embodiments, the polishing composite comprises from about 8% to about 28%, particularly from about 10% to about 15%, and more particularly from about 11% to about 14% by weight of a hard crosslinkable binder component. In certain embodiments, the polishing composite comprises from about 0.5% to about 5%, particularly from about 0.6% to about 1%, and more particularly from about 0.7% to about 0.9% by weight of a material capable of initiating addition polymerization.

[0016] Binders may be radiation curable through an addition polymerization mechanism. A silane coupling agent can be included in the slurry of particulate grains and binder precursor to facilitate an association bridge between the binder and the particulate grains. In certain embodiments, the silane coupling agent may be present in an amount of up to about 1% by weight, particularly from about 0.05% to about 0.4%, and more particularly from about 0.1% to about 0.3%. However, those skilled in the art know that other amounts can also be used, for example, depending on the size of the mineral. Suitable silane coupling agents include methacryloxypropylsilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3,4-epoxycyclohexylmethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane (e.g., available under the trade names A-174, A-151, A-172, A-186, A-187, and A-189 from Witco, Greenwich, Connecticut), allyltriethoxysilane, diallyldichlorosilane, divinyldiethoxysilane, and meta, para-styrylethyl-trimethoxysilane (e.g., commercially available under the trade names A0564, D4050, D6205, and Sl588 from United Chemical Industries, Bristol, Pennsylvania), dimethyldiethoxysilane, dihydroxydiphenylsilane, triethoxysilane, trimethoxysilane, triethoxysilanol, 3-(2-aminoethylamino)propyltrimethoxysilane, methyltrimethoxysilane, vinyltriacetoxysilane, methyltriethoxysilane, tetraethyl orthosilicate, tetramethyl orthosilicate, ethyltriethoxysilane, amyltriethoxysilane, ethyltrichlorosilane, amyltrichlorosilane, phenyltrichlorosilane, phenyltriethoxysilane, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, and mixtures thereof, but are not limited thereto.

[0017] For special purposes, other materials can be added to the polishing composite. These include, but are 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 stabilizers, dispersants, antioxidants, antistatic agents, lubricants, opacifying agents, defoaming agents, antibacterial agents, antifungal agents, and combinations thereof. In certain embodiments, the additive is an organic substance. In certain embodiments, the polishing composite includes a dispersant in an amount of up to about 2% by weight, particularly from about 0.1% to about 1.8%, and more particularly from about 0.8% to about 1.4%. In certain embodiments, the polishing composite includes a coupling agent in an amount of up to about 1% by weight, particularly from about 0.05% to about 0.4%, and more particularly from about 0.1% to about 0.3%. In certain embodiments, the polishing composite includes a colorant in an amount of up to about 1% by weight, particularly up to about 0.5%, and more particularly up to about 0.3%. In certain specific embodiments, the polishing composite includes a photoinitiator in an amount of from about 0.5% to about 5% by weight, particularly from about 0.6% to about 1%, and more particularly about 0.8%; a first particulate grain in an amount of from about 25% to about 55% by weight, particularly from about 35% to about 45%, and more particularly from about 38% to about 42%; and a second particulate grain in an amount of from about 1% to about 30% by weight, particularly from about 12% to about 25%, and more particularly from about 16% to about 24%. The polishing composite includes a binder phase and a mineral phase, but the mineral phase is not considered to directly contribute to the polishing ability of the polishing composite and functions as a filler due to its relative softness and small size. Rather, the lapping performance results from the characteristics of the overall combination of the binder phase and the mineral phase.

[0018] In one embodiment, the polishing composite of the present invention is used to form a structured polishing article including a plurality of substantially identical shaped formed polishing composites attached to a substrate. As used herein, the "formed polishing composite" refers to a polishing composite having a shape designed through experiments to have excellent lapping performance and durability. In one embodiment, the designed shape is formed by curing one or more binder components of a fluid mixture containing soft mineral particles. The mixture is placed on a support and cured while filling a cavity on the surface of a manufacturing tool. Such a formed polishing composite has a shape substantially identical to the inverse shape of the cavity. In one embodiment, the formed polishing composite is pyramid-shaped and its dimensions are substantially identical across all composite features.

[0019] The formed polishing composite of the present invention includes an in-plane shape having a concave angle. This shape is also referred to herein as a concave polygon or a re-entrant polygon. That is, the formed polishing article has at least one interior angle that is between 180° and 360°. A concave polygon has a convex hull having n sides. In one embodiment, n is at least 3. The lapping performance of the polishing composite of the present invention having an inner concave angle is superior to that of a comparative polishing composite having only inner convex angles or a comparative polishing composite having an interior angle of less than 180°. A polishing composite having only inner convex angles is also referred to herein as a convex polygon. Illustrations of concave polygons and convex polygons are shown in FIGS. 1 and 2.

[0020] The polishing composite of the present invention includes a bottom surface and one or more top surfaces. The bottom surface forms the shape of a concave polygon of the polishing composite and has vertices from 1 to n and concave interior angles. Increasing the number of vertices and sides of the polishing composite may reduce the lapping performance. Without being bound by theory, generally, as the number of sides increases, the support area of the pattern also increases, the pressure applied to each side decreases, and the ability to cut dirt decreases. In one embodiment, the longest diagonal of the polygon of the bottom surface is from about 0.3 mm to about 6 mm in length.

[0021] The upper surface of the polishing composite can include a single surface or multiple surfaces. The upper surface can be defined as a point, a line, or a plane. In certain embodiments, the upper surface of the polishing composite can be planarized. By planarizing the upper surface, the tactile sensation of the formed features can be softened.

[0022] In certain embodiments, the bottom surface has the shape of a star polygon, particularly a regular star polygon. Top and side views of a four-point star polygon are shown in FIGS. 3 and 4.

[0023] In certain embodiments, the feature may not have a plane of symmetry. In certain embodiments, one or more upper surfaces may contact or intersect the bottom surface. An example of an embodiment where the polishing composite does not have a plane of symmetry and the upper surface intersects the bottom surface is shown in FIG. 5. As can be seen from this figure, the polishing composite does not need to be a regular polygon.

[0024] The shaped polishing composite and the structured polishing article having the shaped polishing composite can be formed by a manufacturing tool. The manufacturing tool has a surface that defines a main plane and includes a plurality of cavities that bulge as depressions from the main plane. These cavities define the inverse shape of the polishing composite and serve to generate the shape, size, and arrangement of the polishing composite. The cavities can be provided in substantially any geometric shape as long as it is the inverse shape of a geometric shape suitable for the polishing composite. For example, the polishing composite can be cubic, cylindrical, prismatic, hemispherical, rectangular, pyramidal, truncated pyramidal, conical, truncated conical, or columnar. The pattern in which the cavities are arranged is selected to balance the scuffing performance, visual aesthetics, tactile sensation of the individual composite features, and consumption of the composite precursor.

[0025] The manufacturing tool can take the form of a belt, sheet, continuous sheet or web, coating roll (e.g., a rotogravure roll), a sleeve attached to the coating roll, or a die. In certain embodiments, the manufacturing tool is replicated from a master tool. The master tool can be manufactured by any conventional technique known to those skilled in the art, including but not limited to photolithography, turning, engraving, hobbing, electroforming, and diamond turning. U.S. Patent No. 5,851,247 (Stoetzel et al.) describes a manufacturing tool made of a thermoplastic material that can be replicated from a master tool, which is hereby incorporated by reference. When the manufacturing tool is replicated from the master tool, the master tool provides an inverse shape of the desired pattern for the manufacturing tool. In certain embodiments, the master tool is made of nickel-plated metal (e.g., nickel-plated aluminum, nickel-plated copper, or nickel-plated bronze). The manufacturing tool can be replicated from the master tool by pressing a sheet of thermoplastic material against the master tool while heating the master tool and / or the thermoplastic sheet to emboss the thermoplastic material in the pattern of the master tool. Alternatively, the thermoplastic material can be directly extruded or cast onto the master tool. The thermoplastic material is then cooled to a solid state and separated from the master tool to produce the manufacturing tool. The manufacturing tool may optionally include a release coating to facilitate the release of the polished article. Examples of suitable release coatings include, but are not limited to, silicone and fluorochemicals.Suitable methods for manufacturing manufacturing tools are disclosed in U.S. Patent Nos. 5,435,816 (Spurgeon et al.), 5,658,184 (Hoopman et al.), and U.S. Patent Application 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 September 3, 1997), the disclosures of which are incorporated herein by reference.

[0026] In one embodiment, in a method for manufacturing a structured abrasive article, first, a fluid and curable slurry containing a mixture of a binder precursor and a plurality of minerals is introduced into a cavity included in the outer surface of a manufacturing tool to fill the cavity. Next, a substrate having a first major surface and a second major surface on the opposite side is introduced onto the outer surface of the manufacturing tool over the filled cavity so that the slurry wets one major surface of the substrate to form an intermediate article. Then, before the intermediate article is separated from the outer surface of the manufacturing tool, the binder is cured to form an abrasive article coated with a shaped composite. Next, the structured abrasive article is removed from the surface of the manufacturing tool. In another embodiment, in a method for manufacturing an abrasive article, first, a fluid and curable slurry containing a mixture of a binder precursor and a plurality of minerals is introduced onto the front surface of a substrate so that the slurry wets the front surface of the substrate to form an intermediate article. Then, the slurry is introduced onto the outer surface of a manufacturing tool having a plurality of cavities on the outer surface on the support surface side of the intermediate article so that the cavities are filled. Then, before the intermediate article is separated from the outer surface of the manufacturing tool, the binder precursor is cured to form an abrasive article coated with a shaped composite. Next, the abrasive article is removed from the surface of the manufacturing tool. In certain embodiments of both of the above-described methods, these steps are performed continuously, providing a method for efficiently manufacturing the structured abrasive articles of the present invention.

[0027] When forming a structured abrasive article, a plurality of shaped abrasive composites are attached to at least one major surface of a substrate. The shaped abrasive composite provides a three-dimensional shape that protrudes outward from the surface of the substrate. The abrasive composites can be arranged on the substrate in a pattern (i.e., non-random arrangement) or in a disordered or random arrangement. In certain embodiments, the abrasive composites are arranged on the substrate in a non-random arrangement that exhibits a degree of repeatability.

[0028] Materials suitable for the substrate of the present invention include, but are not limited to, polymer films, papers, cloths, metal films, vulcanized fibers, nonwoven substrates, combinations thereof, and chemically treated versions thereof. In certain embodiments, the substrate is a polymer film such as a polyester or polyurethane film. In certain embodiments, the substrate is transparent to ultraviolet light. In certain embodiments, the substrate is coated with an adhesion promoting layer such as poly(ethylene-co-acrylic acid) or an ultraviolet curable "tie coat" layer, or is subjected to an adhesion promoting surface treatment such as corona treatment, flame treatment, or electron beam irradiation. After the abrasive article is formed, the substrate can be laminated to another substrate. For example, the substrate can be laminated to a flexible or rigid polyurethane foam material to provide an effective means of manipulating the abrasive article by the user.

Examples

[0029] The present invention is described more specifically in the following examples, but many modifications and variations within the scope of the present invention will be apparent to those skilled in the art, and these are for illustrative purposes only. Unless otherwise specified, all parts, percentages, and ratios reported in the following examples are by weight. Where applicable, brand names and trade names are shown in all capital letters.

[0030]

Table 1

[0031] The formulations of Examples 1-8 are shown in Table 2 below.

[0032]

Table 2

[0033] [Test Method] Sheaffer Cut Test To evaluate the relative abrasiveness of the articles of the present invention, the articles tested were cut into circular samples approximately 4.5 centimeters in diameter. The articles were secured to the drive plate of a Sheaffer polishing tester (available from Frasier Precision Company, Gaithersburg, Maryland) using a plastic brush fastener available under the trade name "INSTA-LOK" from Minnesota Mining and Manufacturing Company. For each article tested, a circular acrylic work piece (available under the trade name "ACRYLITE" from American Cyanamid Co.) was used. All work pieces were approximately 10.16 cm in diameter and approximately 0.317 cm thick. The initial dry weight of each work piece was recorded and the work piece was secured to the lower turntable of the tester using double-sided foam tape. The test was conducted at 5,000 revolutions under a load of 2.26 kg, and 40 - 60 drops of water per minute were applied to the surface of the acrylic disk. After the test, the final weight of the work piece was measured and the weight loss of the acrylic disk during the test was reported as the result (reported as grams per 5,000 revolutions).

[0034] Food Soil Removal Test To measure the initial efficiency of a scouring article when removing carbonized food stains from a stainless steel disk (10.16 cm in diameter × 0.31 cm thick), a measured amount of the mixed food stain composition was applied to the stainless steel disk and baked at 232 °C for 30 minutes. The mixed food stain composition included approximately 120 g of tomato juice, approximately 120 g of cherry juice, approximately 120 g of ground beef (70% lean), approximately 60 g of shredded cheddar cheese, approximately 120 g of whole milk, approximately 20 g of white all-purpose flour, approximately 100 g of granulated sugar, and 1 Grade AA egg. The disk was alternately coated and baked three times, weighed, and then attached to the lower turntable of a Sheaffer polishing tester modified to accommodate the disk. A 2.26 kg (5 lb) head weight was used as the applied force. The 4.5 cm diameter samples tested were saturated with water, placed in the center, fixed to the upper turntable of the tester, and the disk was lubricated with 1 drop of water per second and tested for 50 cycles under wet conditions. After the desired number of rotations, the dry weight of the disk (in milligrams) was measured and the weight loss of the dry disk was reported.

[0035] Evaluation Index The evaluation index is used to compare the scouring performance against substrate damage and is obtained by dividing the output of the food stain removal test (mg per 50 cycles) by the output of the Sheaffer cut test (g per 5000 cycles).

[0036] [Comparison with Other Polishing Products] The average food stain removal amount (based on the food stain removal test), average acrylic cut amount (based on the Sheaffer cut test), and the ratio of the food stain removal amount to the acrylic cut amount (evaluation index) for Examples 1 and 2 (both 4-point stars), and Polishing Laminates 1 and 2 are shown in Table 3 below.

[0037]

Table 3

[0038] As shown in Table 3 above, the articles of Examples 1 and 2 with the formed scouring pad features demonstrated performance far superior to that of conventional Heavy-Duty Scotch-Brite® products, showing higher selectivity for the removal of dirt on hard substrate surfaces. That is, it means having excellent scouring performance with little or no surface damage. Therefore, it is concluded that the characteristic shape of the abrasive article has a surprisingly important influence on the food soil removal performance.

[0039]

Table 4

[0040] The "hexagon", "dot", and "four-point star (FPS)" patterns are shown in FIGS. 6, 7, and 8, respectively. As shown in Table 4, the pattern with the four-point star (FPS) feature removed approximately 44% more food soil, even though the coat weight of the composite was about 50% lower than that of the "hexagon" and "dot" patterns. Different from the features in the "hexagon" and "dot" patterns, the FPS feature is a concave polygon, which means that at least one interior angle is 180° < 8 < 360°. Such a shape creates sharp, scouring-like exposed edges, which may contribute to the high performance.

[0041] In certain embodiments, the formed features of the abrasive article can be substantially flat. The food soil removal results of abrasive composites made from the composition of Example 2 and having modified features of three-point star (TPS), four-point star (FPS), and six-point star (SPS) are shown in Table 5 below. Exemplary figures of TPS, FPS, and SPS abrasive composites with pointed and flat upper surfaces are shown in FIGS. 9-11, respectively.

[0042]

Table 5

[0043] As can be seen from Table 5, it can be understood that by flattening the upper surface, the scuffing performance significantly decreases throughout the test. This indicates that the relatively sharp upper surface plays a relatively important role in the scuffing performance.

[0044] [Influence of Polishing Minerals on Performance] An unexpected aspect in the performance of the shaping scuffing features of the present invention is the lack of relative importance of the size and concentration of the polishing minerals used in the mineral or particulate granular phase. In the following examples, aluminum oxide is used as the mineral in the formulation of the polishing composite of the hexagonal scuffing feature. The results are shown in Table 6, which is in contrast to the results of industrial polishing products where the influence of the size and concentration of the polishing particles can be easily identified.

[0045]

Table 6

[0046] The lack of influence of aluminum oxide sheds light on an important mechanism difference between the designed polishing features for household cleaning and those for industrial applications, providing useful insights for the design of scuffing formulations. In the industry, abrasives are generally used with hand-held or fixed power tools, which can provide much greater pressure and higher speed than a human arm or a shearing machine. When high pressure and high speed are used, the designed polishing features break down much more quickly (through wear and destruction), constantly exposing new polishing minerals. However, when the abrasive is used by hand or with a shearing machine (i.e., at low pressure and low speed), the polishing composite generally does not break and wears slowly. Therefore, in contrast to industrial-use abrasives, when there are no polishing mineral particles on the surface of the product, the polishing performance of the scuffing product for household cleaning results from the mechanical properties of the composite as a whole rather than from individual polishing particles.

Claims

1. Structured polished articles, A substrate having a first main surface and a second main surface, Multiple molded and polished composites, Includes, A structured polishing article, wherein each of the molded polishing composites has a bottom surface that contacts the first main surface of the substrate, each of the bottom surfaces has a concave polygonal shape, and each of the concave polygons has a convex hull with n sides.

2. The structured polished article according to claim 1, wherein the value of n is 3.

3. The structured polished article according to claim 1, wherein the base surface has the shape of a star polygon.

4. The structured polished article according to claim 1, wherein each of the molded polishing composites has an upper surface defined as a point, line, or plane.

5. The structured polished article according to claim 1, wherein the longest diagonal of the bottom surface is between 0.3 mm and 6 mm in length.

6. Structured polished articles, A substrate having a first main surface and a second main surface, A molded and polished composite having a bottom surface, Includes, The bottom surface of the at least one molded polished composite is placed on the first main surface of the substrate, A structured polished article wherein the bottom surface of the molded polished composite has at least one concave interior angle.

7. The structured polished article according to claim 6, wherein the bottom surface of the molded polished composite has 1 to n vertices and concave interior angles.

8. The structured polished article according to claim 6, wherein the molded polishing composite forms a discontinuous layer along the first main surface of the substrate.

9. A molded and polished composite, Binder phase and The particulate phase dispersed within the binder phase, Includes, A molded polishing composite having at least one concave interior angle.

10. The molded polishing composite according to claim 9, wherein the molded polishing composite has at least three concave interior angles.

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