Patent Application
20160374531
The present disclosure relates to scrubbing articles having a UV cured textured surface. More particularly, the present disclosure relates to scrubbing articles formed by a thick, single layer substrate and a UV treated texture layer formed on at least one surface of the substrate to provide the scrubbing article with enhanced surface treating capabilities.
A variety of cleaning articles in the form of pads and wipes have been developed and made commercially available for household and industrial use. Consumers oftentimes desire to use the articles for cleaning or surface treating tasks requiring scrubbing which in turn may include various degrees of abrading and/or scouring. For example, it can be difficult, if not impossible, to remove dried food from a countertop using an inherently soft article. Furthermore, overly flexible or drapable articles may prove unwieldy when used to scour a surface as there is no substantive handle for comfortable holding of the article when scrubbing or scouring a surface. Further still, while a scouring or abrading action is often desired, consumers likewise desire a scrubbing pad or wipe that is not overly abrasive on relatively soft or easily scratched surfaces. Finally, consumers often find cleaning articles that are pre-loaded with a cleaning/disinfecting/sanitizing chemical or chemicals to be useful and convenient.
In addition, manufacture of cleaning articles oftentimes involves forming a texture or abrasive layer on a surface of one substrate and subsequently bonding or laminating the textured substrate to a secondary substrate or material, for example to provide the desired handle thickness described above. Requiring additional substrates involves added time and cost in the manufacturing process. It is therefore desirable to provide a single substrate material that has the desired handling properties noted above such that an abrasive surface may be formed directly onto the thick substrate.
Scrubbing articles have been developed to address some of the above-identified desires and concerns. For example, U.S. Pat. No. 7,829,478 to Johnson et al., describes a scrubbing wipe article including a nonwoven substrate and a texture layer. The texture layer is a non-crosslinked, abrasive resin-based material that is printed onto at least one surface of the nonwoven substrate. Johnson et al. teach that the texture layer composition is printed onto the substrate and then caused to coalesce to bond the composition to the substrate. Johnson et al. further describe that the resin constituent does not crosslink as part of the coalescing step and that coalescing represents a distinct advantage over other scrubbing wipe article forming techniques in which a lengthy curing period is required to achieve a sufficient hardness value. The nonwoven scrubbing wipe article of Johnson et al. can be used “dry” or can be loaded with a chemical solution.
U.S. Patent App. Pub. No 2006/0286884 to Thioliere et al. describes a wiping article comprising a liquid-absorbent web material and abrasive areas comprising cured binder material disposed on a surface of the web. The web material may include woven, knitted and non-woven materials. Non-woven materials may include dry-laid, wet-laid and spun-bonded materials. Suitable binder materials are disclosed that can be cured by heating, cooling or ultraviolet light.
U.S. Patent App. Pub. No. 2007/0212965 to Smith et al. describes a flexible scrubbing material that combines at least two discrete components, one being a continuous flexible substrate and one a discontinuous abrasive layer affixed to the flexible substrate. The abrasive layer is a set of plates formed from a material different than the continuous flexible substrate. The plate material is a printable material that subsequently solidifies, such as epoxy. Smith et al. teach that the abrasive plates can be formed from a solidified material such as ultraviolet or thermally curable polymeric materials with or without abrasive particles embedded inside. Smith et al. further describe a technique for printing the plates onto the substrates such as conventional screen-printing, UV etching and roller-printing. An adhesive is sprayed on the fabric prior to application of the plates. Other cleaning wipe constructions include or incorporate mildly abrasive particles within or at a surface of the base substrate. For example, U.S. Pat. No. 5,213,588 to Wong et al. describes an abrasive wipe consisting of a paper towel-like base substrate having printed thereon a mixture containing irregularly-shaped polymeric particles.
Various materials and material compositions may be used to form a textured surface layer of a scrubbing material. Further, texture layers may be deposited or formed on a substrate using a variety of methods. Some methods include printing, coating (e.g., roll, spray etc.), embossing, micro-replicating, or etching (e.g., laser, mechanical, etc.) a material or materials onto a substrate to form a textured surface (also referred to herein as an “abrasive surface”) having various degrees of abrasion. Crosslinking of the materials (i.e., abrasives) formed on the substrate can significantly improve a variety of properties of the deposited or formed abrasives, including the durability, hardness, tensile and impact strength, high-heat properties, solvent and chemical resistance, abrasion resistance, and environmental stress crack resistance.
Ultraviolet light curing is a known photochemical process in which high-intensity ultraviolet light is used to cure various materials including coatings and adhesives. UV treatment can be used to effect sterilization, polymerization and crosslinking of materials. UV treatment is a rapid, clean and relatively cost-effective method for crosslinking and/or polymerizing materials and offers many advantages over traditional drying methods such as increased production speed, reduced reject rates and improved properties of the treated materials.
As described above, a scrubbing article having a thickness that allows for comfortable handling by a user is desired. Likewise, improvements in the properties of the scrubbing surface (e.g., texture layer) of a scrubbing article may be beneficial and therefore desirable. Finally, improvements to the manufacturing processes of scrubbing articles can be advantageous. A need therefore exists for a scrubbing article that includes the benefits and advantages of a thick, single layer substrate having a UV treated textured surface for scrubbing.
A scrubbing article including a substrate made of a single-layer foam or sponge material and a UV crosslinked texture layer formed on a surface of the substrate. Substrates of the present disclosure may be formed to have a thickness that allows for ease of handling during a scrubbing or cleaning function. The substrate can have a thickness of between 1 and 5 cm and may particularly have a thickness of 3 cm. A second texture layer can be formed on any other surface of the substrate. In some embodiments the texture layer defines a pattern. In embodiments, the texture layer includes a plurality of randomly distributed texturings. The texture layer has a hardness at least equal to and in embodiments, greater than the hardness of the substrate. In embodiments, the texture composition includes a resin and at least one photoinitiator and can include additional minerals, fillers, colorants, thickeners, defoaming agents, surfactants or other constituents. In embodiments, a chemical can be absorbed into the substrate, formed on the substrate surface, and/or provided as part of the texture layer composition.
Methods of manufacturing a scrubbing article according to the disclosure include forming a UV treatable composition onto a surface of a substrate to form a UV crosslinkable texture layer and UV crosslinking the UV crosslinkable texture layer by exposing the layer to UV radiation to form a UV crosslinked texture layer. In methods according to the disclosure, the UV treatable composition is a UV crosslinkable composition. In some embodiments, the UV treatable composition is a UV polymerizable composition.
Compositions of the substrate 12 and the texture layer 14, as well as processing thereof, are provided below. The scrubbing article 10 may be described as providing a “scrubbiness” attribute. The term “scrubbiness” is in reference to an ability to abrade or remove a relatively small, undesirable item otherwise affixed to a surface as the article is moved back and forth over the item. A substrate can be given a scrubbiness characteristic not only by forming a hardened scrubbing material on the substrate's surface (i.e., harder than the substrate itself), but also and perhaps more prominently via the extent to which the so-formed material extends from or beyond the substrate surface in conjunction with side-to-side spacing between individual sections of the scrubbing material. The texture layer of the present disclosure provides and uniquely satisfies both of these scrubbiness requirements.
By way of further explanation, the texture layer 14 defines a plurality of discrete portions (e.g., the various dot-like portions shown in
Regardless of the pattern design and/or extension distance of portions (e.g., 20a, 20b) from the surface 16, during a scrubbing application, a user (not shown) will normally hold the article 10 by grasping the article for example along a side or edge 15. The thickness “t” of article 10 allows for easy grasping or holding of the article 10 as described more fully below. The user will then position the scrubbing article 10 such that the texture layer 14 is facing the surface to be scrubbed. An example of this orientation is provided in
Importantly, the UV treated texture layer 14 of the present disclosure may be configured to have a relative hardness at least equal to or greater than the hardness of the substrate 12 to which the layer is imparted, as briefly referred to above. Stated otherwise, the local hardness of the texture layer portions (e.g., 20a, 20b) or overall texture layer 14 is equal to or greater than the hardness of the entire article 10, or the “global hardness”. Article 10 may thus be defined as having global flexibility, since the substrate 12 is softer or more flexible in relation to the harder, less flexible abrasive/texture layer 14. Hardness of a texture composition 14 after having been formed on a substrate as well as hardness of a substrate (for comparison) can be achieved in a number of ways. For example, hardness of a material can be established by determining the Rockwell indentation hardness, such as described in ASTM E18-14a: Standard Test Methods for Rockwell Hardness of Metallic Materials; by determining Knoop and Vickers hardness, such as described in ASTM E384-10: Standard Test Method for Knoop and Vickers Hardness of Materials; by determining the durometer hardness, such as described in ASTM D2240-05: Standard Test Method for Rubber Property-Durometer Hardness, or by determining the Brinell hardness, such as described in ASTM E10-14: Standard Test Method for Brinell Hardness of Metallic Materials. An article having these characteristics is uniquely useful as a scrubbing article in that the article 10 is sufficiently flexible to allow a user to make contact in, on and about a variety of objects to be scrubbed, while the hardness of the abrasive layer 14 provides the desired scrubbing performance. The above features are readily achieved via the textured layer and UV treatments of the present disclosure as described below.
The substrate 12 can be formed from a variety of cloth, foam and sponge materials and may take a variety of forms. Any cloth, foam or sponge material or combination of materials suitable for use as a consumer scrubbing article can be used including, without limitation, polyurethane foams such as the polyurethane foam commercially available under the trade designation, TEXTURED SURFACE FOAM, POLYETHER, M-100SF from AERO TECHNOLOGIES LLC, Newark, Del., USA, cellulose sponges such as the sponge commercially available under the trade designation of SCOTCH-BRITE STAY CLEAN NON-SCRATCH, cat. No. 20202-12 from 3M COMPANY, St. Paul, Minn., USA, and biodegradable L200, N250, S100 sponge cloths from Kalle GmbH, Wiesbaden, Germany.
As used herein, the term “foam” refers to a colloidal dispersion made of two distinct phases formed by two dissimilar materials. Thus, a foam may also be referred to as a solidified colloidal dispersion. For polyurethane (PU) foams, for example, a gas (most commonly carbon dioxide gas formed during foaming reactions) is dispersed within the PU liquid to form a distinct dispersed phase. This dispersion is subsequently solidified to obtain solid PU foam. The term “sponge” as used herein is likewise used to describe a solidified colloidal dispersion. For example, in forming a cellulose sponge, a salt is dispersed in the cellulose mixture (viscose) to form a distinct dispersed phase. The dispersion is subsequently solidified and the salt is eliminated to obtain solid cellulose sponge. Definitions of sponge and foam materials as used herein may be consistent with those defined in, “Foundations of Colloid Science”, Vol. 1, Robert J. Hunter, Oxford University Press, New York, 1987, incorporated by reference here in its entirety.
The materials and forms of the substrate 12 can be selected to provide varying ranges of desired properties, such as extensibility, elasticity, durability, flexibility etc., that are particularly suited to a given scrubbing task and/or are particularly suited to forming a texture composition thereon. As indicated, materials useful for substrate 12 may be selected to have durability properties in a wide range. For example, the durability of materials suitable for use in scrubbing articles is often categorized as “disposable” (meaning that an article formed from the material is intended to be discarded immediately after use), “semi-disposable” (meaning that an article formed from the material can be washed and re-used a limited number of times), or “reusable” (meaning that an article formed from the material is intended to be washed and re-used). Scrubbing articles 10 of the present disclosure can be selected or formed to have any of these durability properties. Also as indicated above, materials may be selected based upon their flexibility.
According the present disclosure, consumers may prefer a relatively more rigid article that still maintains some degree of flexibility. A rigid article may be one that is formed of a composition and into a form that substantially holds its shape both when held by a user or when placed on an irregular surface. Notably, a more rigid cleaning article may still have some degree of flexibility so as to conform to contours of a surface to be scrubbed. However, the articles contemplated by the present disclosure may be of the type that return to an original form after having been bent, compressed or otherwise manipulated during a cleaning action.
The substrate 12 may be selected or formed to have a surface (e.g., 16) that readily accepts the formation of a texture layer 14 thereon. In particular, the surface of the substrate may be formed to have a skinned layer to obtain a “smoother”, more uniform, less porous or finer-pore surface. By smoother or more uniform is meant that the surface (or surfaces) of the substrate has characteristics that differ from the body 13 (
The substrate 12 has a thickness “t” (
The substrate 12 as depicted in the cross-sectional view of
Other sponges and foams are likewise contemplated and these examples are not meant to be limiting. Regardless of the exact construction, however, the substrate 12 is highly conducive to handling by a user otherwise using the article 10 for scrubbing purposes and is selected having regard to the intended use of the scrubbing article 10.
As discussed above, the texture layer 14 is an abrasive composition that is formed on substrate 12 and subsequently UV crosslinked or UV polymerized or both as will be described below. The exact composition of the texture layer 14 can vary depending upon desired end performance characteristics. To this end, a texture layer composition is initially formulated and then formed on the substrate 12. This composition will include a selected resin and may include additional constituents such as mineral(s), filler(s), colorant(s), thickener(s), defoaming agent(s), surfactant(s) etc. Regardless of the exact composition, however, the selected composition is UV treatable (i.e., polymerizable, crosslinkable) and imparts the desired features (e.g., manufacturability, scrubbiness, durability, hardness and abrasion resistance) to the scrubbing article 10. As a point of reference, the texture layer composition 14 may be described as “UV crosslinkable” or “UV polymerizable”, or both, prior to UV treatment (e.g., crosslinking, polymerization) of the texture layer 14 and as “UV crosslinked” or “UV polymerized”, or both, after the texture layer 14 has undergone UV treatment. The processes of printing and UV treating the texture layer compositions of the present disclosure are further discussed below. In addition, as defined herein, an interim scrubbing article 17 is formed after the texture layer composition 14 is formed on substrate 12 but prior to UV treatment of the composition 14 and will likewise be discussed in further detail below.
Various materials are suitable for forming the texture layer 14. As described above, texture layer 14 comprises a resin composition and may comprise various polymers and/or monomers. Some acceptable resins include those resins selected from the group consisting of styrene-butadiene resin, acrylic resin, phenolic resin, nitrile resin, ethylene vinyl acetate resin, polyurethane resin, styrene-acrylic resin, vinyl acrylic resin and combinations thereof. Other non-limiting examples of binder resins useful with the present disclosure include amino resins, alkylated urea-formaldehyde resins, melamine-formaldehyde resins, acrylic resins (including acrylates and methacrylates) such as vinyl acrylates, acrylated epoxies, acrylated urethanes, acrylated polyesters, acrylated acrylics, acrylated polyethers, vinyl ethers, acrylated oils, and acrylated silicones, alkyd resins such as urethane alkyd resins, polyester resins, reactive urethane resins, phenolic resins such as resole and nonvolac resins, phenolic/latex resins, epoxy resins, and the like. The resins may be provided as monomers, oligomers, polymers, or combination thereof. Monomers may include multifunctional monomers capable of forming a crosslinked structure, such as epoxy monomers, olefins, styrene, butadiene, acrylic monomers, phenolic monomers, substituted phenolic monomers, nitrile monomers, ethylene vinyl acetate monomer, isocyanates, acrylic monomers, vinyl acrylic monomer and combinations thereof. Other non-limiting examples of binder resins useful with the present disclosure include amino acids, alkylated urea monomers, melamines, acrylic monomers (including acrylates and methacrylates) such as vinyl acrylates, acrylated epoxies, acrylated urethanes, acrylated polyesters, acrylated acrylics, acrylated ethers, vinyl ethers, acrylated oils, and acrylated silicones, alkyd monomers such as urethane alkyd monomers, and esters.
Other desirable features of texture layer 14 compositions include compositions having a molecular weight that allows for the formed UV treatable texture layer 14 to have sufficient (e.g., minimum level of) adhesion to the substrate 12 to which it is applied such that it does not readily wipe off of or shift along the substrate surface 16 (i.e., such that the texture layer 14 formed on the substrate stays on the substrate surface 16 after transfer of the texture layer 14 to the substrate 16 and prior and/or subsequent to UV treatment). Specifically, materials may be selected to have molecular weights or viscosities allowing the texture layer 14 composition to be flowable in a manner that will fill the holes or voids of a stencil pattern during transfer to or forming of the composition on a substrate 12, sufficiently to adhere to the substrate 12 and to hold the desired pattern shape upon removal of the stencil from the substrate.
The composition of the texture layer includes a photoinitiator and can optionally include a promoter or a retardant as part of the formulation or composition of texture layer 14, according to some embodiments of the present disclosure, as described in detail in textbooks such as Ullmann's Encyclopedia of Industrial Chemistry (section “Radiation Chemistry”). Exemplary photoinitiators are those provided in TABLE 1A, herein below. Some initiators and promoters that can assist UV crosslinking or UV polymerization, or both, include alpha-hydroxy and alpha-aminoacetophenones or phosphine oxides, commercially available under the trade designations of Darocur 1173, Irgacure 651, Irgacure 369, Irgacure 819, Lucirin TPO, all commercially available from BASF CORP., Florham Park, N.J., USA; those based on aromatic ketones, such as benzophenones, thioxanthones, methylphenylglyoxylate, and camphorquinone; co-initiators, such as N-phenylglycine, ethyl p-dimethylaminobenzoate, and 2-mercaptobenzoxazole; onium salts, such as iodonium or sulfonium salts, commercially available under the trade designations, such as Irgacure 250 (from BASF CORP., Florham Park, N.J., USA), Cyracure UVI 6976 (from DOW CHEMICAL COMPANY, Midland, Mich., USA), and Esacure 1187 (from LEHMANN & VOSS & CO., Hamburg, Germany).
In some embodiments, the texture layer 14 optionally further includes a particulate additive for enhanced hardness. To this end, and as described in greater detail below, the scrubbing article 10 of the present disclosure is useful in a wide variety of potential applications having different scrubbing requirements. For some applications, it is desirable that the scrubbing article 10, and in particular the texture layer 14, be more or less abrasive than others. While the above-described resin component of the texture layer 14 independently imparts a scrubbiness feature to the article 10 greater than other available scrubbing articles, this scrubbiness characteristic can be further enhanced via the addition of a particulate component. With this in mind, a wide variety of minerals or fillers as known in the art can be employed. Useful minerals include Al2O3, “Minex” (available from The Cary Co. of Addison, Ill.), SiO2, TiO2, etc. Exemplary fillers include CaCO3, talc, etc. Where employed, the particulate component additive comprises less than 70% by weight of the texture layer 14, more preferably less than 50% by weight, most preferably less than 30% by weight. Further, the particulate component may consist of inorganic, hard, and small particles. For example, the “Minex” mineral particulate component has a median particle size of 2 microns and a Knoop hardness of about 560. Of course, other particle size and hardness values may also be useful. The inorganic nature of the particulate component, in conjunction with the non-ionic resin component, renders the resulting texture layer 14 amenable for use with any type of chemical solution.
The texture layer 14 can further include a colorant or pigment additive to provide a desired aesthetic appeal to the wiping article 10. Appropriate pigments are well known in the art, and include, for example, products sold under the trade name SUNSPERSE, available from Sun Chemical Corp. of Amelia, Ohio. Other coloring agents as known in the art are equally acceptable and in some embodiments comprise less than 10% of the texture layer composition by weight.
Additionally, the texture layer composition can include a thickening agent or agents to achieve a viscosity most desirable for the particular printing technique employed and speed of the manufacturing line. In this regard, appropriate thickening agents are known in the art and include, for example, methylcellulose and a material available under the trade name “RHEOLATE 255” from Rheox, Inc. of Hightstown, N.J. Another acceptable thickening agent is available from Huntsman International LLC, High Point, N.C., USA under the trade designation of LYOPRINT PT-XN. A thickening agent may be unnecessary depending upon the selected resin and processing technique; however, where employed, the thickening agent preferably comprises less than approximately 40% by weight of the texture layer composition. In other embodiments, a salt component may be provided in the composition to aid in causing an ionic reaction between components of an emulsion and thereby likewise generate an increase in the viscosity of the composition, as is known in the art. Notwithstanding the above, the composition of texture layer 14 may be non-ionic, according to some embodiments.
As indicated above, anti-foaming agents may be included in the composition to provide defoaming or emulsification of the composition. As described in Ullmann's Encyclopedia of Industrial Chemistry (section “Foams and Foam Control”), some anti-foaming materials are carrier oils; such as water-insoluble paraffinic and naphthenic mineral oils, vegetable oils, tall oil, castor oil, soybean oil, peanut oil; silicone oils, such as dimethylpolysiloxanes; hydrophobic silica; Hydrophobic fat derivatives and waxes, such as fatty acid esters of monofunctional and polyfunctional alcohols, fatty acid amides and sulfonamides, paraffinic hydrocarbon waxes, ozokerite, and montan wax, phosphoric acid mono-, di-, and triesters of short- and long-chain fatty alcohols, short- and long-chain natural or synthetic fatty alcohols, water-insoluble soaps of long-chain fatty acids, including aluminum stearate, calcium stearate, and calcium behenate, perfluorinated fatty alcohols; water-insoluble polymers, such as low molecular mass, fatty acid modified alkyd resins, low molecular mass novolaks, copolymers of vinyl acetate and long-chain maleic and fumaric acid diesters, and methyl methacrylate-vinylpyrrolidone copolymers, poly(propyleneglycols) and high molecular mass propylene oxide adducts to glycerol, trimethylol, propane (1,1,1-tris(hydroxymethyl)propane), pentaerythritol, triethanolamine, dipentaerythritol, polyglycerol, addition products of butylene oxide or long-chain a-epoxides with polyvalent alcohols. An example anti-foaming agent is a silicone emulsion commercially available under the trade designation of XIAMETER AFE-1520, manufactured by Dow Corning Corporation of Midland, Mich., USA.
In some embodiments, the composition of the texture layer 14 may include binder resins, ceramic microparticles or processing agents as described in U.S. Provisional Patent Application Ser. No. 62/121,644, entitled, “Consumer Scrubbing Article with Ceramic Microparticles and Method of Making Same” filed on Feb. 27, 2015 and incorporated by referenced herein in its entirety.
Finally, and as previously described, the scrubbing article 10 of the present disclosure can be used “dry” or can be loaded with a chemical (solution or solid) for disinfecting, sanitizing or cleaning (e.g., a soap). The term “loaded” is in reference to a chemical solution being absorbed by the substrate 12 prior to being delivered to a user. In addition or alternatively, the chemical may be sprayed onto a surface of the cloth. In still further embodiments, a chemical may be provided in or as part of the texture layer composition 14. Thus, deposited (e.g., printed) texture layer 14 may comprise printed soap scrubbing dots (e.g., 20a, 20b,
Manufacture or formation of the scrubbing article 10 of the present disclosure is depicted in the simplified block form of
This, along with the disclosed substrate constructions, represents distinct advantages over other techniques used to form a scrubbing article having a textured surface.
Prior to forming a texture layer 14 on a substrate 12, depending upon the type of substrate, the surface 16 of the substrate 12 may be primed or treated. Priming may involve mechanical, chemical, physical and material application methods. For example, some surface priming methods that may be especially useful with the present disclosure include heating, applying pressure, consolidating, flame treating, melting, cutting or removing substrate material. Alternatively, priming may include application of a chemical primer such as an adhesive. Notably, however, in some embodiments, no primer is necessary prior to transfer of the texture layer 14 composition onto the substrate 12 and achieve adequate adhesion.
The texture layer 14 composition can be formed on one or more surfaces of the substrate 12 using a variety of known techniques such as printing, (e.g., screen printing, gravure printing, flexographic printing, etc.), coating (e.g., roll, spray, electrostatic), etching, laser etching, injection molding, micro-replicating, and embossing. In general terms, and with reference to
Once the texture layer 14 is formed on the substrate 12, but prior to exposure to UV radiation (as discussed below), an interim scrubbing article 17 is formed. The interim scrubbing article 17 is characterized as having a UV treatable texture layer 14 that has not yet undergone UV treatment (i.e., the UV light exposure step has not yet been performed). The interim scrubbing article 17 may thus also be referred to as an interim textured scrubbing article 17. Regardless, the interim scrubbing article 17 may next be allowed to remain undisturbed (allowed to wait) for a period of time or may directly or immediately proceed to an optional curing step. The interim scrubbing article 17 may undergo an optional curing step whereby the article 17 is exposed to heat, such as given by an oven (60,
Next, after the texture layer 14 has been formed on the substrate 12, and after any optional steps described above, the interim textured scrubbing article 17 is subjected to UV radiation to crosslink or polymerize, or both, the texture layer 14 composition provided thereon. As illustrated in
Regardless of the exact composition and dimensions of substrate 12 and the composition, dimensions or pattern of the texture layer 14, the scrubbing article 10 of the present disclosure provides a marked improvement over previous consumer scrubbing articles in terms of cost as well as ease and flexibility of the manufacturing processes that may be used in forming scrubbing articles. In addition, scrubbing articles of the present disclosure exhibit suitable abrasion resistance performance and may beneficially include a single layer substrate or non-laminated article that provides superior handling. Likewise, UV crosslinked texture layers 14 of the present disclosure may have increased durability, hardness, tensile and impact strength, high-heat properties, solvent and chemical resistance, and environmental stress crack resistance. Exemplary scrubbing articles 10 are provided below. The components and/or weight percent amounts provided by the compositions can readily be varied, yet fall within the scope of the present disclosure.
All ingredients of TABLE 1A were weighted out to the nearest 0.1 grams in separate rigid plastic containers in desired quantities. A mixture was prepared by placing all ingredients in a rigid plastic container. The photoinitiator was placed last and care was exercised not to expose the photoinitiator to excessive ambient light. The mixture was first mixed by hand for 30 seconds and a lid was secured on the container before starting the mixing. The mixture was then mixed for 30 seconds in a laboratory centrifugal mixer commercially available from FLACKTEK INC., Landrum, S.C., USA under the trade designation of SPEEDMIXER DAC 400.1 VAC-P. The rotation speed of the mixer was set to 2500 rpm. After 30 seconds, the mixer was stopped, and the plastic container which had the mixture in it was removed from the mixer and wrapped with aluminum foil. The container was left undisturbed on a laboratory bench for 24 hours. The list of prepared acrylate and epoxy mixtures is presented in TABLES 2A and 3A.
The foam and cellulose sponge specimens were used as-received. It is evident that any other thick non-woven substrate would be similarly useful. An example of a commercially available thick non-woven substrate was the non-woven bath sponge with a thickness of 3 cm, commercially available under the trade designation of ACTIBEL TONIFICANTE from 3M ESPANA, S.A., Madrid, SPAIN.
Printing the Prepared Compositions onto the Prepared Substrates
For each of the prepared substrates of TABLE 4A, a metal stencil with the texture pattern shown in
It was observed that the relatively smooth surfaces of the foam and cellulose sponge substrates substrate enabled more uniformly printed (sharp) patterns.
After one minute, the printed specimens were subjected to UV radiation under a standard D-bulb (EPIQ 6000, commercially available from Heraeus Noblelight America LLC, Gaithersburg, Md., USA), in a continuous line with a line speed of 9.33 m/min. The D-bulb had a power of 600 W.
The abrasive properties of the printed specimens were tested with a Frazier Schiefer Uniform Abrasion Tester, commercially available from Frazier Precision Instrument Company, Inc. Hagerstown, Md., USA. In the test, the printed specimens were first saturated with deionized water and then used as the abradant. An optically transparent, rigid plastic disk was used as the substrate to be abraded. The disk was laser cut with a diameter of 10.2 cm and with a thickness of 0.3 cm from a rigid plastic sheet commercially available from Evonik Industries AG, Essen, Germany, under the trade designation of ACRYLATE GP. During the test, the abradant abraded the disk with a rotation speed of 250 rpm and the test was terminated when total revolutions reached 1000. The weight of the disk was measured before and after the test to the nearest 0.001 grams. The difference between the weight values was recorded and reported as the percentage of the initial weight in TABLE 5A (under the column of ‘abraded weight from the disk after 1000 revolutions’).
The data presented TABLE 5A indicate that the acrylate formulation printed on different substrates was more abrasive then the epoxy formulation.
All texture layer compositions were mixed with a DAC-400 SpeedMixer™ asymmetric centrifugal mixer (Flacktek Inc., Landrum, S.C. USA) using Flacktek plastic mixing containers. For ink composition 1, 1.5 g of photoinitiator 1 was added to a mixing container with 162.5 g of the acrylate and mixed for several minutes until the photoinitiator was dissolved, then 135.0 g of filler 1, 5.7 g of filler 2, 0.2 g of pigment, 4.7 g of flow agent 1, and 4.7 g of flow agent 2 were added to the container and mixed for 3 minutes at 2500 rpm. For ink composition 3, 3.0 g of photoinitiator 2 was added to a mixing container with 161.7 g of the acrylate and mixed for several minutes until the photoinitiator was well mixed in the acrylate, then 141.1 g of filler 1, 7.9 g of filler 2, 0.2 g of pigment, 4.7 g of flow agent 1, and 4.7 g of flow agent 2 were added to the container and mixed for 3 minutes at 2500 rpm. The compositions of the two inks are listed below:
The substrates were used as-received with the exception of cutting. Foam 1 (cellulose sponge cloth) was prepared by cutting into squares approximately 22 cm by 22 cm. Foam 2 was prepared by cutting into squares approximately 17 cm by 17 cm.
Printing the Prepared Compositions onto the Prepared Substrates and Dot Height
The printing composition was screen printed onto substrates Foam 1 and Foam 2 using a metal screen with circular openings approximately 1.8 mm in diameter; each opening was separated from other openings by a distance of approximately 2 mm. The ink was forced through the holes in the screen using a squeegee. The resulting printed articles therefore had a pattern of printing composition dots. The printing composition dots were either raised or at the sponge surface, depending on the substrate and amount of printing composition applied. On the cellulose sponge cloth substrate of Foam 1, the printing composition dots were raised with a cured printing composition dot height of approximately 0.5-1.6 mm. On the more porous polyurethane sponge of Foam 2, the printing composition dots were at the surface of the sponge (but exposed when the sponge was compressed). Printing composition viscosity will have an effect on printing composition dot height. A more viscous printing composition would result in a higher printing composition dot height, and a less viscous printing composition would result in a lower printing composition dot height. The printing composition viscosity was not varied, however: both printing compositions were on the order of 10,000 cPs (as measured with a Brookfield Model RVTD viscometer).
Printing compositions were cured under either 395 nm LED ultraviolet lamps (Phoseon) or a D-bulb lamp (Heraeus-Fusion), without nitrogen purge. Curing was done at line speeds up 60 m/min (200 ft/min). At this speed using the D-bulb, printing compositions were cured with a measured energy as low as 223 mJ/cm2, 83 mJ/cm2, 9 mJ/cm2 and 267 mJ/cm2 for UVA, UVB, UVC, and UVV, respectively. At this speed, for the 395 nm LED bulb, printing compositions were cured with a measured energy as low as 42 mJ/cm2.
Durability of the finished article (i.e., adhesion of the printing composition dots) was tested using a straight line washability tester (Gardner Laboratory, Silver Spring, Md.) similar to that described in ASTM D-3450, with the following differences:
Both of the finished article with Foam 1 and the finished article with Foam 2 exceeded 5000 cycles (over 2 hours continuous scrubbing) without loss of printed composition dots. The finished articles were determined to be non-scratching, as the glass substrate remained free of scratches after the tests.
The substrates were used as-is except in the case where the moisture content was high to a degree based on hand-feel. If upon touching, the user's hand did not feel moist, it was not considered “wet.” If upon touching, a user's hand felt wet, the substrate was placed in a HAO-L oven set at 105 degrees C. for 15 minutes (oven available from Thermocon Instruments (P) Limited, 872, HAL, 3rd Stage, (opp BEML gate), Bangalore-75, INDIA).
Printing the Prepared Compositions onto the Prepared Substrates and Dot Height
To prepare the printed compositions, take a 250 ml beaker and transfer 150 grams of filled UV curable resin composition (OPV9051 grade) and add 6 grams of SG 510 Red Ink to the beaker (i.e. 4%) under constant stirring. Then using stirrer model IKA Eurostar-ST PCV at 150 rpm for 15 minutes at room temperature. Then, allow the mixture to settle at room temperature.
Mount a polyester mesh screen frame with the desired print design to an ATMA printing machine Model No. AT-80 P available from ATMA CHAMP ENT. CORP., No. 65, Wuquan 7th Road, WUGU Dist., New Paipei City 248, TAIWAN. The prepared composition, as prepared above, was poured at the middle of the screen. The printing bar was run left and right one time to spread the ink over the mesh screen frame. The printing speed was set at 8 m/min. Then the substrate was placed under the screen and printed with single/and double pass. The printed substrate was then dried with a Fusion UV dryer model no. P600 M available from Heraus Nobelight Fusion UV Inc., 910 Clopper Road, Gaithersburg, Md. 20878, USA for curing and setting of the coated composition on the substrate.
The Effect of Substrate Dimension and Feel after UV Curing
To determine the effect of UV curing on product dimension, three wipes were prepared as generally discussed above. Each wipe passed through the UV curing chamber a different number of times. A “single pass” wipe was passed through the UV curing chamber one time. A “two pass” wipe was passed through the UV curing chamber twice and a “three pass” wipe was passed through the UV curing chamber three times. At a UV curing chamber feed rate of 17 units, the wipe was exposed to about 2,500 mJ/cm2 for each pass. It was observed that the “three pass” wipes did show some dimensional change and that the wipe felt harsh and stiff to the touch. After leaving the wipe overnight in the oven (without heat), the wipe regained the original dimensions and feel, thus indicating that UV curing and drying was not irreversibly altering the dimension and feel of the wipe.
The three wipes were further tested to evaluate the impact of drying and moistening the wipe on stability of the printed texture layer. It was observed that after wetting the wipe and then drying at 105 degrees C. for two hours in a TEMPO dryer model no. TI 126D (available from TEMPO Instruments & Equipments (1) PVT. LTD., To Syringe Comp, W.E. Highway, B/H, Samrat Hotel, Pandurang Wadi, PO: Mira, Dist.: Thane-401 104, INDIA), no cracks were found in the texture layer on any of the three wipes. The wipes were then re-wetted and, again, no cracks formed in any of the printed texture layer. The three wipes were also washed for two hours in a Samsung WA80K8SEG/XTL washing machine (available from Samsung India, Mumbai, Maharashtra, INDIA) at 60 degrees C. In this experiment, a noticeable loss of the printed texture layer was observed in each of the wipes.
The one pass wipe suffered considerable printed textured layer loss. The two pass wipe had noticeable loss of the printed textured layer but the printed textured layer did not crack. The three pass wipe retained the most of the printed textured layer and the printed texture layer only slightly wore off. The performance of the two pass wipe and the three pass wipe were deemed satisfactory in this regard.
In a surface abrasion or crocking test, each of the three wipes were tested per AATCC 8 test method and the test was continued even after 10 turns to check the performance consistency of abrasive coating on a sponge wipe substrate. The equipment used for testing was a MECRUB XT MAG-C0221 crock meter available from MAG SOLVICS PRIVATE LTD, Coimatore-642109, INDIA. The wipes were tested until a severe loss of printed texture layer occurred. A severe loss of printed texture layer occurred in 10 cycles for the single pass wipe, 50 cycles for the two pass wipe and 10 cycles for the three pass wipe.
The one pass, two pass and three pass wipes were also tested on a crayon stain to determine how many scrubbing passes would be required to remove the stain. This test was conducted using a 57 mm long×7.5 mm diameter wax crayon available from Camel Wax Crayons, Kokuyo Camlin Ltd, 48/2, Hilton House, Central Road, MIDC, Andheri(E), Mumbai-400093, INDIA. The Camlin Wax crayon was used to make a stain. A circle of 3 cm in diameter was made on a granite table top and was colored in by manually holding the crayon like a pencil. The granite table top was a regular, non-polished surface without any deep cracks, holes or uneven surface areas. All of the crayon stains were made at the same time. The test wipe made moist and pliable with water and the printed side was manually wiped over the crayon stain in the same way used by typical consumers of such wipes for in-home use. The test for each wipe was conducted by the same operator at the same time to adopt generally uniform speed and pressure throughout the test in attempts to avoid variations in the results. The number of strokes need to clean the crayon stain completely from the granite test surfaces was recorded. Each pass of the wipe constituted one stroke. Post cleaning of the stain, the granite test surface was cross-checked to ensure the stain was completely cleaned from the test surface. As illustrated in TABLE 3C below, the one pass, two pass and three pass wipes all performed better than many of the other scrubbing articles tested.
The above testing of the one, two and three pass wipes described in Example C indicate that the printed surface of the single pass wipe produces a very light coating that is removed relatively easily in washing and rubbing tests. The double pass wipe performed satisfactory in all tests described in Example C. The three pass wipe was stiffer and, as a result, the printed surface wore out in the crocking and washing tests.
Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US16/16617 | 2/4/2016 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62121705 | Feb 2015 | US |
