Abrasive Article with a Resilient Dusting Surface

Background The present invention relates to abrasive articles, and more particularly, to a hand-held, abrasive article that includes a resilient dusting or cleaning surface.

Common sanding tasks calling for considerable detail work or access to small confined areas, or for sanding contoured surfaces, often require that the surfaces be hand sanded. Hand-held sanding devices for this purpose have essentially consisted of a sanding block for holding conventional sandpaper wrapped over the block. By using a sanding block as a sandpaper holder, hand-applied sanding forces on the sandpaper can be increased and more evenly distributed.

The difficulty with the above-mentioned prior sanding devices is the necessity of installing or wrapping a separate piece of sandpaper around the device. This installation or wrapping process presents some inconvenience to the user. For example, if the paper is improperly installed, it is susceptible to buckling or falling off. Also, the device requires the purchase of separate sheets of sandpaper that is a further inconvenience in terms of the amount of supplies needed.

U.S. Patent No. 4,887,396 (Lukianoff) discloses a hand-sized sanding device that eliminates the need for a separate sheet of sandpaper. The sanding device is provided with its own integral abrasive surfaces that can be manufactured at a sufficiently low cost to be disposable. The sanding device of Lukianoff can be conveniently used to hand sand a variety of standard, contoured, or shaped surfaces, such as trim or molding surfaces, and for projecting into exactly defined areas. Another type of sanding device is the resilient flexible sanding sponge. Sanding sponges generally include a layer of abrasive particles adhered to a foam body by a flexible adhesive. The flexible adhesive layer and the foam body permit the layer of abrasive to conform to the surface being abraded.

When sanding surfaces such as wood, plaster, or drywall, small particles of dust are released into the air and surrounding surfaces. These particles often settle over the surface being sanded. A user will typically clean the surface being sanded to asses the

quality of the sanding and to determine if more sanding is necessary. To clean the surface, the user must use a separate cleaning tool, such as a dusting cloth or tack cloth, to clean the surface being sanded. It may be time consuming to locate and use a separate cleaning tool. Additionally, dusting cloths often become loaded with the dust and simply push the dust and do not effectively pick up the dust. Tack cloths are often coated with an adhesive to help pick up the dust and retain it in the cloth. However, the user risks transferring adhesive to the surface being cleaned with the cloth. The transferred adhesive can prevent a quality application of stain, varnish, or sealant to the surface being sanded.

Summary

The present invention provides an abrasive article that is capable of abrading a surface and cleaning the dust from the surface being abraded without the need for an adhesive on the cleaning surface of the abrasive article. In one embodiment, the present invention provides an abrasive article consisting essentially of a foam latex rubber layer forming a cleaning surface, a binder coated on the foam latex rubber layer, and abrasive particles attached to the binder forming an abrasive surface.

In another embodiment, the present invention provides an abrasive article comprising an abrasive layer on an intermediate support layer forming an abrasive surface and a foam latex rubber layer attached to the intermediate support layer, opposite the abrasive layer, and forming a cleaning surface. The intermediate support layer is selected from the group consisting of a paper, a file, and a nonwoven of lofty web of fibers.

In another embodiment, the present invention provides an abrasive article comprising an abrasive layer comprising a lofty web of fibers forming an abrasive surface and a foam latex rubber layer laminated to the abrasive layer, opposite the abrasive surface, and forming a cleaning surface. The cleaning surface is essentially free of adhesive.

Brief Description of the Drawings

FIG. 1 is a perspective view of a first embodiment of an abrasive article according to the present invention.

FIG. 2 is a perspective view of a second embodiment of an abrasive article according to the present invention.

FIG. 3 is a perspective view of a third embodiment of an abrasive article according to the present invention.

While the above -identified drawings and figures set forth one embodiment of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation.

It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this invention. The figures may not be drawn to scale. Like reference numbers, incremented by 100, have been used to denote like parts.

Detailed Description

FIG. 1 shows a flexible resilient abrasive article 100 comprising an abrasive layer 110 and a foam latex rubber layer 130. The abrasive layer 110 comprises a plurality of abrasive particles 112 at least partially embedded in a binder layer 114. In this embodiment, the binder layer 114 is directly on the foam latex rubber layer 130. The resulting abrasive article 100 comprises at least one abrasive surface 160 and at least one cleaning surface 170.

FIG. 2 shows a flexible resilient abrasive article 200 comprising an abrasive layer 210 and a foam latex rubber layer 230. The abrasive layer 210 comprises a nonwoven. Such a nonwoven is a Scotch-Brite™ Scouring Pad available from 3M Company of St.

Paul, MN. The abrasive layer 210 is attached to the foam latex rubber 230 through any known variety of attachments techniques such as adhesives or laminating. The resulting abrasive article 200 comprises at least one abrasive surface 260 and at least one cleaning surface 270. FIG. 3 shows a flexible resilient abrasive article 300 comprising an abrasive layer

310 and a foam latex rubber layer 330. The abrasive layer 310 comprises an

intermediate support layer 320 and a plurality of abrasive particles 312 at least partially embedded in a binder layer 314 on the intermediate support layer 320. The intermediate support layer 320 of the abrasive layer 310 is attached to the foam latex rubber 330 through any known variety of attachment techniques such as adhesives or laminating. The resulting abrasive article 300 comprises at least one abrasive surface 360 and at least one cleaning surface 370.

In each of the embodiments of the abrasive article described in FIGS. 1-3 the resulting abrasive article includes an abrasive layer and a foam latex rubber layer. The abrasive layer provides the abrasive surface that is capable of sanding such surfaces as wood, plaster, drywall, or other similar surfaces. The foam latex rubber layer provides the cleaning surface that is capable of removing small particles, such as, dust before or after the abrasive surface is used to abrade or scour the surface.

The abrasive layer, foam latex rubber layer, and attaching layer (if included in the embodiment) are each discussed in further detail below.

Abrasive Layer

The abrasive layer may comprise any known abrasive such as but not limited to abrasive particles embedded in a binder or nonwoven materials. Optionally, an intermediate layer may be provided. The intermediate layer may be, for example, a paper, a nonwoven, a foam, film or a sponge that is directly attached to the foam latex rubber layer.

If abrasive particles and a binder are used, the binder may be directly coated on the foam latex rubber, as depicted in FIG. 1, or an intermediate layer may be included. Therefore, either the foam latex rubber or the intermediate layer may be coated with the binder and abrasive particles. In one embodiment, the binder is a flexible adhesive that bonds the layer of abrasive particles to either the foam latex rubber layer or the intermediate layer. The binder adheres the abrasive particles together while being sufficiently flexible to conform to the flexible surface of the foam latex rubber or the intermediate support. A flexible adhesive formulation and method of applying it is described in U.S. Pat. No. 6,059,850, herein incorporated by reference, which can be used to form the binder. Other suitable binders include any of the thermosetting or

photocurable resins including phenol-formaldehyde, urea-formaldehyde and melamine- formaldehyde resins, epoxy resins, acrylate resins, aminoplast resins and urethane resins, including mixtures and/or modified versions thereof. The binder may be coated using conventional techniques, such as knife coating, spray coating, roll coating, rotogravure coating, curtain coating, and the like.

In some embodiments a pre-make coat resin layer may be used to seal the surface of the foam latex rubber layer or intermediate layer, if included. Suitable pre-make coat resins may be applied as solvent or water based formulations or as 100% solids hot melt formulations. Additionally, in some embodiments, the abrasive article may also include an optional size coat extending over the binder and the abrasive particles. Suitable size resins include those mentioned for pre-make coat resins.

In general, any suitable abrasive particles may be used with this invention. Suitable abrasive particles include fused aluminum oxide, heat treated aluminum oxide, alumina-based ceramics, silicon carbide, zirconia, alumina-zirconia, garnet, diamond, ceria, cubic boron nitride, ground glass, quartz, titanium diboride, sol gel abrasives and combinations thereof. The abrasive particles can be either shaped (e.g., rod, triangle, or pyramid) or unshaped (i.e., irregular). The term "abrasive particle" encompasses abrasive grains, agglomerates, or multi-grain abrasive granules. The abrasive particles can be deposited onto the binder layer by any conventional technique such as electrostatic coating or drop coating.

If included, the intermediate support layer is attached to the foam latex rubber and includes the abrasive surface, which typically will include a coating of the binder and abrasive particles. In one preferred embodiment, the intermediate support layer is resiliently deformable (i.e., indentable) and recoverable when squeezed by the thumb and fingers of the user's hand and thus is not likely to slip from the hand even if the fingers are wet or greasy. The intermediate support layer may be somewhat resiliently axially compressible and acts as a cushion between the user's hand and the work surface as the abrasive article is being pushed back and forth to perform the abrading function.

The intermediate support layer may be open cell foam, closed cell foam, textured, or planar, natural or synthetic sponge, nonwoven, paper, or film. In one embodiment, the

intermediate support layer is closed-cell foam. In some embodiments, the intermediate support layer may be constructed from high tear strength felted urethane foam.

Abrasive particles along with a binder are not required for the abrasive layer. Another suitable abrasive layer may be a nonwoven. Such a nonwoven may comprise, for example, an open, lofty nonwoven web of fibers bonded at their points of contact by a resin and/or melt fusion. The nonwoven may also include abrasive particles dispersed throughout the nonwoven or coated on a surface of the nonwoven and secured to the nonwoven web by a binder.

Suitable fibers include crimped, staple, synthetic organic fibers such as polyester fibers and nylon fibers, which may be processed and entangled into nonwoven webs by conventional web-forming machines such as that sold under the tradename "Rando Webber" through Rando Machine Company of New York, NY. The resulting web may be heated to bring about melt-bonding of the fibers at their points of contact, and/or may be treated (by spraying, roll-coating, etc.) with a liquid resin which bonds the fibers together.

Suitable nonwovens, which may serve as the abrasive layer, are available commercially in a variety of thicknesses, densities and abrasive powers under the tradename Scotch-Brite™ from 3M Company of St. Paul, MN.

Foam Latex Rubber

The foam latex rubber layer provides the cleaning surface. Particularly, the foam latex rubber is effective at removing dust and other small particles from work surface. In one embodiment, the foam latex rubber is an open-cell foam. The open cell-foam provides small pockets that are capable of capturing and retaining the dust and other small particles that are encountered during cleaning before and after sanding. A foamed latex rubber suitable for the foam latex rubber layer is sold under the tradename Gonzo available from Quality Rubber Company, a division of Zephyr Manufacturing of Sedalia, MO.

The latex rubber material is a natural material that exhibits a natural tackiness without the need for the addition of a secondary adhesive. This natural tackiness is unique and advantageous in use as a cleaning and dusting material. The tackiness assists

in picking up and retaining dust and small particles. Because a secondary adhesive is not required, the risk of adhesive transfer to the surface being cleaned is eliminated. To increase the tackiness of the abrasive article, in one embodiment, an additional adhesive may be included for some applications. Additionally, the latex rubber material may be cleaned using water or other solvents and following cleaning retains a natural tackiness.

Attaching Layer

If included, the attaching layer secures the abrasive layer to the foam latex rubber. As shown in FIGS. 2 and 3 an attaching layer is used to secure the abrasive layer to the foam latex rubber and the intermediate layer of the abrasive layer to the foam latex rubber, respectively.

The attaching layer typically is an adhesive. Suitable adhesives include pressure- sensitive adhesives, hot melt adhesives, or thermosetting adhesives. In one embodiment, laminating, using heat and pressure, is used to secure these layers together.

Abrasive Article

The abrasive articles depicted in FIGS 1-3 are generally rectangular with a substantially planar abrasive surface and a substantially planar cleaning surface that is opposite the abrasive surface. The abrasive article may be square or rectangular and is of a suitable size for handheld sanding. For example, the abrasive article may have a length from 3 to 6 inches (7.62 to 15.24 cm), a width from 1 to 6 inches (2.54 to 15.24 cm) and a thickness from 0.5 to 4 inches (1.27 to 10.16 cm). The abrasive article may be any convenient geometric shape other than square or rectangular including, but not limited to, triangular, circular, and in the shape of a polygon. Additionally, the abrasive article need not be a defined shape but could be randomly shaped such as a wave shape.

As shown in the embodiment depicted in the figures, the abrasive article includes a single abrasive surface and a single cleaning surface. As shown in these embodiments, the abrasive surface and the cleaning surface are generally planar and parallel to one another. The present invention is not limited to a single abrasive and a single cleaning surface. The abrasive article may be of a shape or configuration having two or more abrasive surfaces and/or having two or more cleaning surfaces. Additionally, the

abrasive surface and cleaning surface need not be planar and may be of other geometric or curved shapes. Other embodiments and configurations of the abrasive surface and cleaning surface are within the scope of the present invention, so long as there is at least one abrasive surface and one cleaning surface. To enhance the durability of the abrasive article, an embedded reinforcing scrim may be included. The scrim may be positioned between the foam latex rubber and the abrasive layer or may be imbedded within an intermediate layer, if included.

The abrasive article can be used in a variety of cleaning, sanding, and surface conditioning processes. A particularly useful area for the abrasive article is in the preparation of surfaces, especially wood, plaster, and drywall, and for painting or finishing.

To use the abrasive article, the user can grasp the abrasive article by hand with the cleaning surface of the foam latex rubber facing the palm of the user's hand. Then, the abrasive surface of the abrasive layer is available for contact with a surface. The user sands the surface with the abrasive layer and, following sanding, uses the cleaning surface of the foam latex rubber to wipe the dust and debris from the surface being sanded and any surrounding surfaces. Once the foam latex rubber is fully loaded with dust and debris from cleaning, the user can rinse the foam latex rubber with water to remove the dust and debris. When the foam latex rubber layer is cleaned, the abrasive article is available for further use.