Patent Application
20230249490
The disclosure relates to an erasable and reusable marking surface suitable for marking with marking materials as handwritten notes, drawings, painting, sketches, etc., and can be quickly erased with a cleaning fluid.
Writings, drawings, paintings, sketches, etc., are typically made as markings on a surface, such as pages of a notebook or on an artist easel, with inks, paints, dyes, coloring, etc. Once the surface is marked with such inks, the surface is generally not reused. For example, students typically need to purchase new notebooks every school year for taking notes in classes.
U.S. Pat. No. 11,001,094 discloses a moisture-reusable notebook system, wherein the ink marking can be removed by moisture. However, the system only works with a special kind of ink, e.g., thermochromic ink, as in a FRIXION™ pen. The thermochromic ink refers to a temperature-sensitive ink that temporarily changes color with exposure to heat. Attempts have been made to migrate the marking or writing to other formats, such as digital tablet devices. However, these devices are expensive, and adoption of such devices are limited.
There is still a need for reusable surfaces which can be reused for writings, drawing, paintings, etc., by quickly erasing or removing markings, e.g., drawing, paintings, etc., with convenient and easy means, e.g., a wipe moistened or soaked with water, or a diluted isopropyl alcohol wipe, and the like. Additionally, erasing markings from the marking surface does not require the use of a specific marking instrument or the ink.
In a first aspect, a laminate for marking is disclosed, comprising, consisting essentially of, or consists of a substrate having a marking surface to facilitate markings with a marking material. The marking surface comprises an outer layer containing a sulfonated block copolymer. The sulfonated block copolymer has an ion exchange capacity (IEC) of at least 0.5 meq/g. The outer layer containing the sulfonated block copolymer has a thickness of at least 1 μm. At least 50% markings can be erased from the marking surface with a wipe moist with a cleaning fluid after wiping for less than 5 min.
In a second aspect, the cleaning fluid is selected from the group consisting of water, isopropyl alcohol, rubbing alcohol, acetone, and mixtures thereof.
In a third aspect, the sulfonated block copolymer has a degree of sulfonation of 10 to 100 mol %.
In a fourth aspect, at least 80% of markings can be erased from the marking surface with a wipe moist with the cleaning fluid after wiping for less than 2 min.
The following terms will be used throughout the specification:
“Laminate” refers to an object having at least one layer of the same or different materials.
“Substrate” means a layer or a structure of one or more materials on which a subsequent layer or coating is deposited, or adhered to, or arranged together forming a laminate.
“Marking material” refers to a gel, solvent, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, a painting, or design. The marking material is used for painting, drawing, or writing with pen, brush, reed pen, or quill. As used herein, the marking material can be used interchangeably with ink or paint or colorant, in reference to markings made on a marking surface or substrate.
“Mark” or “Marking” means writing as with words, designs, pictures, drawings, or paintings provided on a surface or a substrate, using a marking material.
“Cleaning fluid” refers to a fluid that can facilitate removal of a pre-existing ink or markings from a surface with a wipe moist with the cleaning fluid. The cleaning fluid can be selected based on the type of the ink is used, and/or the time duration for which the ink has dried on the surface.
“Wipe” means a flexible sheet, a piece of fabric, a paper, a towel, or a sponge that can partially or fully absorb a fluid, for the removal or erase of a marking on a surface.
“Peel-and-stick” or “peel-and-stick film” refers to a laminate having at least two layers, a release layer or liner which can also be a support layer, and another layer for “sticking” or laying down on a surface. The peel-and-stick can be self-adhesive, or releasable or peelable, or removable after being attached to a surface.
“Releasable” or “separable” bond in the context of layers or surfaces means that the layers or surfaces are generally attached or fastened to each other yet can be separated with the application of a certain amount of force. In order to be “releasable,” or “separable” the surfaces must be capable of being fastened and separated, and the force applied to separate the layers or surfaces can be applied by hand.
“Surface pH” refers to a pH on a contact surface, which results from surface bound moieties e.g., the outer most or surface layer. Surface pH can be measured with commercial surface pH measuring instruments, e.g., SenTix™ Sur-electrode from WTW Scientific-Technical Institute GmbH, Weilheim, Germany.
“Erasable” (or erasability) means having >50%, or >60%, or >70%, or >80%, or >90%, or up to 100% of a marking material erased or removed from a marking surface, after the first wiping or first rubbing of the marking surface for <5 min, or <2 min, or <1 min, with a wipe moist with a cleaning fluid.
“Moist wipe” refers to a wipe substrate containing a liquid or a gel applied thereto so that a sufficient amount of liquid/gel is retained on or within the wipe substrate until its utilization by a user, for the wipe to be damp or slightly damp to the user upon touching. The liquid/gel can be applied to the wipe substrate by impregnation, coating, immersing, dipping, sinking, drench, covering, rinsing, wetting, absorbing, and the like.
“Susceptible to sulfonation” refers to a polymer, polymer block, compound, monomer, oligomer, etc., being predisposed, or sensitive, or capable of reaction with sulfur containing compound, e.g., SO3, H2SO4, etc., under conditions conventionally employed for sulfonation, wherein sulfonation is very likely to occur to obtain a sulfonated product. In embodiments, a polymer block “susceptible to sulfonation” upon sulfonation, the degree of sulfonation is at least 10 mol %, or at least 20 mol %, or at least 30, or at least 50 mol %, or at least 75 mol %, of the total polymer block, for the polymer block to have at least 10 mol %, or at least mol %, or at least 30, or at least 50 mol %, or at least 75 mol % sulfonic acid or sulfonate ester functional groups.
“Resistant to sulfonation” means having little if any sulfonation of the respective block under conditions conventionally employed for sulfonation, with <10 mol %, or <8 mol %, or <5 mol % sulfonic acid or sulfonate ester functional groups in the polymer block.
“Sulfonated styrenic block polymer” or SSBC refers to a styrenic block copolymer precursor which contains sulfonic acid and/or sulfonate ester groups.
The disclosure relates to a laminate for marking which contains a substrate with a marking surface to facilitate markings on the marking surface using a marking material. The marking surface comprises an outer layer containing a sulfonated block copolymer. At least 50% of the marking material can be removed from the marking surface with a wipe moist with a cleaning fluid.
(Sulfonated Block Copolymer)
The sulfonated block copolymer refers to polymers having a sulfonate group, e.g., —SO3, either in the acid form (e.g., —SO3H, sulfonic acid) or a salt form (e.g., —SO3Na). The term “sulfonated block copolymer” also covers sulfonate containing polymers, e.g., polystyrene sulfonate.
The sulfonate group containing polymers other than the sulfonated block copolymer can be used, such as, for example, perfluorosulfonic acid polymers (e.g., sulfonated tetrafluoroethylene), sulfonated polyolefins, sulfonated polyimides, sulfonated polyamides, sulfonated polyesters, polystyrene sulfonates, sulfonated polysulfones such as polyether sulfone, sulfonated polyketones such as polyether ether ketone, sulfonated polyphenylene ethers, and mixtures thereof.
In embodiments, the sulfonated block copolymer is characterized as being sufficiently sulfonated, meaning having at least 10 mol % of sulfonic acid or sulfonate ester functional groups based on total mol of the number of monomer units or polymer blocks to be sulfonated (“degree of sulfonation”). In embodiments, the sulfonated block copolymer has a degree of sulfonation of at least 10 mol %, or >15, or >20, or >25, or >30, or >40, or >50, or >60, or 10-100, or 15-95, or 20-90, or 25-85, or 30-80, or 35-75 mol %, based on polymer blocks susceptible to sulfonation. The degree of sulfonation can be calculated by NMR or ion exchange capacity (IEC).
In embodiments, the sulfonated block copolymer is a sulfonated styrenic block copolymer (SSBC) obtained by sulfonation of a styrenic block copolymer (SBC) precursor which is any of linear, branched, or radial block copolymer having at least one end block A and at least one interior block B. The sulfonated block copolymer has at least a sulfonate group, e.g., —SO3, either in an acid form (e.g., —SO3H, sulfonic acid) or a salt form (e.g., —SO3Na). The sulfonate group can be in the form of metal salt, ammonium salt, or amine salt.
In embodiments, the SBC precursor is prepared by anionic polymerization using techniques known in the art. Other methods, such as cationic polymerization, can also be employed. The anionic polymerization initiator is generally an organometallic compound, such as, an organolithium compound, e.g., ethyl-, propyl-, isopropyl-, n-butyl-, sec-butyl-, tert-butyl-, phenyl-, hexylbiphenyl-, hexamethylenedi-, butadieneyl-, isopreneyl-, 1,1-diphenylhexyllithium, or polystyryllithium. An amount of initiator needed is calculated based on the molecular weight to be achieved, generally from 0.002 to 5 wt. %, based on the amount of monomers to be polymerized. Suitable solvent for the polymerization includes aliphatic, cycloaliphatic, or aromatic hydrocarbons having from 4 to 12 carbon atoms, such as pentane, hexane, heptane, cyclopentane, cyclohexane, methylcyclohexane, decalin, isooctane, benzene, alkylbenzenes, such as toluene, xylene or ethylbenzene, and mixtures thereof. Polymer chain termination can be achieved by quenching with a proton donor or a compound having a leaving group that can be displaced by the carbanionic polymer chain.
If desired, a Lewis base additive, which affects polymerization parameters can also be employed. Examples of Lewis bases include dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, 1,2-diethoxypropane, diethylene glycol dimethyl ether, tetrahydrofuran, tetrahydrofurfuryl ethers, such as tetrahydrofurfuryl methyl ether, and tertiary amines. The additives can influence the extent of 1,2-addition of the conjugated diene, and therefore the vinyl group content in the respective block.
In embodiments, the SBC precursor has a general configuration of: A-B-A, (A-B)n(A), (A-B-A)nX, (A-B)nX, A-D-B, A-B-D, A-D-B-D-A, A-B-D-B-A, (A-D-B)nA, (A-B-D)nA (A-D-B)nX, (A-B-D)nX, (A-D-B-D-A)nX, (A-B-D-B-A)nX or mixtures thereof; where n is an integer from 2 to 30; and X is a residue of a coupling agent. Each block A and D is resistant to sulfonation, and each block B is susceptible to sulfonation.
In embodiments, the coupling agent X includes bi- or polyfunctional compounds, for example divinylbenzene, halides of aliphatic or araliphatic hydrocarbons, such as 1,2-dibromoethane, bis(chloromethyl)benzene, or silicon tetrachloride, dialkyl- or diarylsilicon dichloride, alkyl- or arylsilicon trichloride, tin tetrachloride, alkylsilicon methoxides, alkyl silicon ethoxides, polyfunctional aldehydes, such as terephthalic dialdehyde, ketones, esters, anhydrides, or epoxides. In embodiments, the coupling agent is selected from methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), tetramethoxysilane (TMOS), dimethyladipate, gamma-glycidoxypropyltrimethoxy silane, and mixtures thereof.
In embodiments, the block A has at least one compound selected from polymerized (i) para-substituted styrene, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms; (iv) 1,3-cyclodiene, (v) conjugated dienes having a vinyl content of <35 mol % prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof. If the block A is a polymer of 1,3-cyclodiene or conjugated diene, the block A will be hydrogenated subsequent to preparation of the SBC and before sulfonation of the SBC precursor. In embodiments, the block A contains up to 15 wt. % of vinyl aromatic monomers such as those present in the block B.
In embodiments, the block A is derived from polymerized para-substituted styrene monomers selected from the group consisting of para-methylstyrene, para-ethylstyrene, para-n-propyl styrene, para-iso-propyl styrene, para-n-butyl styrene, para-sec-butyl styrene, para-iso-butylstyrene, para-t-butylstyrene, isomers of para-decylstyrene, isomers of para-dodecylstyrene, and mixtures thereof.
In embodiments, the block A has a Mp of 1-60, or 2-50, or 5-45, or 8-40, or 10-35, or >1.5, or <50 kg/mol. In embodiments, the block A constitutes from 1-80, or 5-75, or 10-70, or 15-65, or 20-60, or 25-55, or 30-50, or >10, or <75 wt. %, based on total weight of the SBC precursor.
In embodiments, the block B is derived from polymerized vinyl aromatic monomers selected from the group consisting of unsubstituted styrene, ortho-substituted styrene, meta-substituted styrene, alpha-methyl styrene, 1,1-diphenylethylene, 1,2-diphenylethylene, and mixtures thereof. In embodiments, the block B has a mixture of the vinyl aromatic monomer and hydrogenated conjugated dienes, such as butadiene or isoprene, having a vinyl content, prior to hydrogenation, of 2-40, or 5-38, or 8-35, or 10-30, or >5, or <40 wt. %, based on total weight of polymerized conjugated diene monomers in the block B.
In embodiments, the block B has a Mp of 10-300, or 20-250, or 30-200, or 40-150, or 50-100, or 60-90, or >15, or <150 kg/mol. In embodiments, the block B constitutes from 10-80, or 15-75, or 20-70, or 25-65, or 30-55, or >10, or <75 wt. %, based on total weight of the SBC precursor. In embodiments, the block B has from 0-25, or 2-20, or 5-15 wt. %, of the para-substituted styrene monomers such as those present in the block A.
In embodiments, the block D is derived from a polymer or copolymer of a conjugated diene monomer selected from the group consisting of isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 3-butyl-1,3-octadiene, farnesene, myrcene, piperylene, cyclohexadiene, and mixtures thereof. In embodiments, the block D has a Mp of 1-60, or 2-50, or 5-45, or 8-40, or 10-35, or 15-30, or >1.5, or <50 kg/mol. In embodiments, the block D constitutes from 10-80, or 15-75, or 20-70, or 25-65, >10, or <75 wt. %, based on total weight of the SBC precursor.
In embodiments, prior to hydrogenation and sulfonation, the block D has a vinyl content of >80, or >85, or >90, or >95, or >98, or >99, or >99.5, or 50-95, or 60-90, or 70-95 wt. %, based on total weight of the polymerized conjugated diene monomers in the block D.
In embodiments, the block D has a hydrogenation level of 60-99%, or 65-95%, or 70-90%, or 75-99%, or >75%, or 85%, or >95%, or >98%.
In embodiments, each block A and B independently has a hydrogenation level of 0-20%, or 2-18%, or 4-15%, or >10%, or >15%, or <20%. A suitable catalyst based on nickel, cobalt or titanium can be used in the hydrogenation step.
The SBC precursor is sulfonated to provide the corresponding SSBC. Sulfonation occurs at the phenyl ring of polymerized styrene units in the block B, predominantly para to the phenyl carbon atom bonded to the polymer backbone. In embodiments, the block B has a degree of sulfonation of 10-100, or 15-95, or 20-90, or 25-85, or 30-80, or 35-75, or 40-70, or >15, or <85 mol %, based on total mol of the block B.
In embodiments, the sulfonated block copolymer is a midblock-sulfonated triblock copolymer, or a midblock-sulfonated pentablock copolymer, e.g., a poly(p-tert-butylstyrene-b-styrenesulfonate-b-p-tert-butylstyrene), or a poly[tert-butylstyrene-b-(ethylene-alt-propylene)-b-(styrenesulfonate)-b-(ethylene-alt-propylene)-b-tert-butylstyrene.
In embodiments, the sulfonated block copolymer has a Mp of 25-500, or 30-450, or 350-400, or 40-350, or 45-300, or 50-250, or >35, or <350 kg/mol.
In embodiments, the sulfonated block copolymer has an ion exchange capacity (IEC) of at least 0.5, or >0.75, or >1.0, or >1.5, or >2.0, or >2.5, or <5.0 or 0.5-3.5, or 1-2.6 meq/g.
In embodiments, the sulfonated block copolymer has a glass transition temperature (Tg) of 80-180° C., or 85-160° C., or 90-150° C., or 100-140° C., or >90° C., or <210° C., measured by Dynamic Mechanical Analysis (DMA), according to ASTM 4065.
The sulfonated block copolymer in embodiments is as disclosed in U.S. Pat. Nos. 9,861,941, 8,263,713, 8,445,631, 8,012,539, 8,377,514, 8,377,515, 7,737,224, 8,383,735, 7,919,565, 8,003,733, 8,058,353, 7,981,970, 8,329,827, 8,084,546, 8,383,735, and U.S. Ser. No. 10/202,494, incorporated herein by reference.
The properties of the sulfonated block copolymer can be varied and controlled by varying the amount of sulfonation, the degree of neutralization of the sulfonic acid groups to the sulfonated salts, as well as controlling the location of the sulfonated group(s). In embodiments, the sulfonated block copolymer is selectively sulfonated for desired water dispersity properties or mechanical properties, e.g., having the sulfonic acid functional groups attached to the inner blocks or middle blocks, or in the outer blocks of a copolymer, as in U.S. Pat. No. 8,084,546, incorporated by reference. If the outer (hard) blocks are sulfonated, upon exposure to water, hydration of the hard domains can result in plasticization of those domains and softening, allowing dispersion or solubility.
In embodiments, the sulfonated block copolymer has a general configuration A-B-(B-A)1-5, wherein each block A is a non-elastomeric sulfonated vinyl aromatic polymer block and each block B is a substantially saturated elastomeric alpha-olefin polymer block, said block copolymer being sulfonated to an extent sufficient to provide at least 1% by weight of sulfur in the total polymer and up to one sulfonated constituent for each vinyl aromatic unit.
Depending on the applications and the desired properties, the sulfonated block copolymer can be modified (or functionalized). In embodiments, the sulfonated block copolymer is neutralized with any of various metal counterions, including alkali, alkaline earth, and transition metals, with at least 10% of the sulfonic acid groups being neutralized. In embodiments, the sulfonated block copolymer is neutralized with inorganic or organic cationic salts, e.g., those based on ammonium, phosphonium, pyridinium, sulfonium, and the like. Salts can be monomeric, oligomeric, or polymeric. In embodiments, the sulfonated block copolymer is neutralized with various primary, secondary, or tertiary amine-containing molecules, with >10% of the sulfonic acid or sulfonate ester functional groups being neutralized.
In embodiments, the monomer or the block containing amine functionality or phosphine functionality can be neutralized with acids or proton donors, creating quaternary ammonium or phosphonium salts. In other embodiments, the sulfonated block copolymer containing tertiary amine is reacted with alkylhalides to form functional groups, e.g., quaternized salts. In some embodiments, the sulfonated block copolymer can contain both cationic and anionic functionality to form so-called zwitterionic polymers.
In embodiments, the sulfonic acid or sulfonate functional group is modified by reaction with an effective amount of polyoxyalkyleneamine having molecular weights from 140 to 10,000. Amine-containing neutralizing agents can be mono-functional or multi-functional; monomeric, oligomeric, or polymeric. In alternative embodiments, the sulfonated polymer is modified with alternative anionic functionalities, such as phosphonic acid or acrylic and alkyl acrylic acids.
In embodiments, amine containing polymers are used for the modification of the sulfonated block copolymers, forming members of a class of materials termed coaservates. In examples, the neutralizing agent is a polymeric amine, e.g., polymers containing benzylamine functionality. Examples include homopolymers and copolymers of 4-dimethylaminostyrene which has been described in U.S. Pat. No. 9,849,450, incorporated herein by reference. In embodiments, the neutralizing agents are selected from polymers containing vinylbenzylamine functionality, e.g., polymers synthesized from poly-p-methylstyrene containing block copolymers via a bromination-amination strategy, or by direct anionic polymerization of amine containing styrenic monomers. Examples of amine functionalities for functionalization include but are not limited to p-vinylbenzyldimethylamine (BDMA), p-vinylbenzylpyrrolidine (VBPyr), p-vinylbenzyl-bis(2-methoxyethyl)amine (VBDEM), p-vinylbenzylpiperazine (VBMPip), and p-vinylbenzyldiphenylamine (VBDPA). In embodiments, corresponding phosphorus containing polymers can also be used for the functionalization of the sulfonated polymers.
Other sulfonated block copolymer can be selected from sulfonated polystyrene-polyisoprene-polystyrene sulfonated in the center segment, sulfonated t-butylstyrene/isoprene random copolymer with C═C sites in their backbone, sulfonated SBR (styrene butadiene rubber) as disclosed in U.S. Pat. No. 6,110,616 incorporated by reference, and mixtures thereof. In embodiments, the sulfonated block copolymer is a water dispersible BAB triblock, with B being a hydrophobic block such as alkyl or (if it is sulfonated, it becomes hydrophilic) poly(t-butyl styrene) and A being a hydrophilic block such as sulfonated poly(vinyl toluene) as disclosed in U.S. Pat. No. 4,505,827 incorporated by reference.
In embodiments, the sulfonated block copolymer is a water-soluble polymer, a sulfonated diblock polymer of t-butyl styrene/styrene, or a sulfonated triblock polymer of t-butyl styrene-styrene-t-butyl styrene as disclosed in U.S. Pat. No. 4,492,785 incorporated by reference.
(Optional Additives)
The sulfonated block copolymer further comprises at least an additive selected from the group consisting of activators, curing agents, stabilizers, neutralizing agents, thickeners, coalescing agents, slip agents, release agents, antimicrobial agents, surfactants, antioxidants, antiozonants, color change pH indicators, plasticizers, tackifiers, film forming additives, dyes, pigments, UV stabilizers, UV absorbers, catalysts, fillers, other polymers, redox couples, fibers, flame retardants, viscosity modifiers, wetting agents, deaerators, toughening agents, adhesion promoters, colorants, heat stabilizers, light stabilizers, lubricants, flow modifiers, drip retardants, antiblocking agents, antistatic agents, processing aids, stress-relief additives, and mixtures thereof. Optional additives, if present, are in an amount of 0.1-20, or 0.5-15, or 1-10, or 0.1-5 wt. %, based on total weight of the sulfonated block copolymer.
(Laminate for Marking)
The laminate for marking comprises a substrate for a marking surface, with a least a portion of the surface being coated with the sulfonated block copolymer. Depending on the end use application of the marking surface, e.g., as a notebook, a white board, an artist easel, etc., the substrate for the marking surface is made from any of synthetic paper, standard paper, waterproof paper, recycled paper, glass, plastic materials, canvas, wood, woven fabric, non-woven fabric, fibers, mixtures of fabric and paper, etc., with an outmost layer comprising the sulfonated block copolymer for writing or marking with a marking material.
In embodiments for use as a notebook, a pouch, a clipboard, a fillable form, the substrate comprises a synthetic material, e.g., polyester, polyolefins (e.g., polypropylene, high-density polyethylene, etc.), polyamide, polystyrene, polyester, polyurethane, polysulfone, polyvinylchloride, styrene-maleic anhydride copolymer, acrylic polymer and copolymer, polycarbonate, polyacrylonitrile, ethylene-vinyl acetate copolymers, and mixtures thereof.
In embodiments for use as a sticky note, a label, a wallpaper, a greeting card, the substrate is made of synthetic paper, standard paper, recycled paper, waterproof paper, fibers, fabric, or mixtures thereof. In embodiments, the substrate has an adhesive backing layer or an adhesive back face that is re-adherable for use as a sticky note or a sticky label.
In embodiments, for an erase board or white board for use in classrooms and conference rooms, the substrate comprises a panel of plastic or glass material, which is transparent or opaque. For the erase board or white board, the substrate can be made of wood, melamine, porcelain, slate, or similar material.
In embodiments, for use as an art board or an easel, the substrate is made from canvas, wood panel, paper materials, or a synthetic material, a polymer such as polyolefin, polycarbonate, acrylic, impact modified acrylic, polyvinyl chloride, or acrylonitrile butadiene styrene, and mixtures thereof.
In embodiments, for use in a rollable marking surface, the substrate comprises a rubber, an elastomeric, or any flexible and elastic material that can be rolled and then return to its original state once unraveled, and optionally a top layer of paper or white board material as mentioned above.
In some embodiments, e.g., as with a desk, the substrate is made of wood, metal, plastic, or any other suitable material known in the art for making furniture.
In embodiments, the outer layer containing the sulfonated block copolymer is formed on the marking surface by forming a coating with a composition comprising the sulfonated block copolymer partially or fully dissolved in a solvent in an amount of 1 to 10 wt. %, based on total weight of the solvent, or <20, or <50, or 5-30, or 1-15, or 10-20 wt. %. Non-limited examples of solvents include water, isopropyl alcohol, acetone, N,N-dimethylacetamide, 1-methyl-2-pyrrolidinone, 1,3-dioxolane, 2-methoxy ethanol, dimethylformamide, benzyl alcohol, cyclopentane, cyclohexane, cycloheptane, cyclooctane, hexane, heptane, nonane, decane, paraffinic oil, methyl-tert-butyl ether, tetrahydrofuran (THF), dioxan, ethyl acetate, dimethylsulfoxide (DMSO), dimethylformamide (DMF), methanol, ethanol, propanol, butanol, toluene, xylene, and mixtures thereof.
In embodiments, the sulfonated block copolymer coating is applied by preparing a solution/dispersion of the polymer in a suitable solvent, then casting on the substrate, with a sufficient thickness of the layer/film being adjusted with a casting knife, followed by drying. In embodiments, the outer layer containing the sulfonated block copolymer is formed on the substrate by methods including but not limited to spray coating, electro-coating, electro-spinning, direct coating, transfer coating, dip coating, slot-die coating, and the like. Multiple coatings/layers can be applied on the substrate depending on desired thickness and end-use applications.
The substrate can be coated with the sulfonated block copolymer as individual pieces, forming pages in notebooks, erase boards, etc. Alternatively, a large piece of the substrate is coated with the sulfonated block copolymer and the large piece is then cut into desired sizes and shapes forming marking surfaces.
In embodiments, the sulfonated block copolymer is applied onto the substrate as a peel-and-stick film to form the outer layer. In the peel-and-stick form, the sulfonated block copolymer is in the form of a laminate having at least two layers with a sulfonated block copolymer layer and a support/release liner. The support/release liner is peeled off and the sulfonated block copolymer layer is applied onto the substrate forming a marking surface.
In embodiments, the sulfonated block copolymer is applied onto the substrate as a coating/layer, or as a self-adhesive film, for an erasable outer layer for writing or marking, having a thickness of at least 1 μm, >5 μm, or >10 μm, or <500 μm, or <200 μm, or <100 μm, or <10 mm, or 10 μm-5 mm, or 1 μm-1 mm, or 50 μm-2 mm, or 1-100 μm. The outer layer of the sulfonated block copolymer can have any of a “smooth finish” or “hard finish” so as to minimize indentation made by writing instruments and maximize the number of times it can be reused.
(Marking Material)
The marking material can be applied as an ink, e.g., in writing instruments such as ball pens, fountain pens, gel pens, markers, felt tip pens, and the like, or as a paint, a colorant.
Non-limiting examples of the marking material can include the ink from cartridges used in printers; ink based on oil or water-based containing additives for certain color effect, e.g., carbon black for black ink, phthalocyanine blue for blue ink; non-thermochromic; or thermochromic ink. The ink can be liquid or solid, e.g., a piece of charcoal.
The marking material can also be applied as a paint, e.g., ink, acrylic paints, oil-based paints, watercolors, gouache paints, encaustic paints, spray paints, pastel colors, crayons, etc. The marking material can be a nail polish.
(Cleaning Fluid)
To erase/remove markings from the marking surface, a cleaning fluid is used. The selection depends on the marking material, e.g., ink or paint, and amount of time elapsed since marking was made (or how long for it to dry up). The cleaning fluid in embodiments is selected from solvents and solutions readily available to consumers, e.g., water, isopropyl alcohol (IPA at >90% concentration), rubbing alcohol (˜70% IPA), acetone, and the like. Other known cleaning fluids for removing markings can also be used, e.g., alcohols such as ethanol, acetoacetates, glycol ethers, glycol esters, terpenes, methyl ethyl ketone, etc.
In embodiments, a wipe is used for erasing or removing the marking. The wipe can be in the form of towelette, absorbent sheet, fabric, sponge, paper, absorbent polymer, and mixtures thereof. The wipe has a sufficient amount of the cleaning fluid to make the wipe damp, moist, or soaked wet. In embodiments, the wipe contains >5, or >10, or >20, or >30, or >40 wt. % cleaning fluid, based on total weight of the wipe.
(Methods for Removing Markings)
In embodiments, straight water is used to remove or erase markings made with any of pens, Indian ink, or acrylic paints. By using water, markings can be removed to >50%, or >60%, or >80%, or up to 100% from marking surface with a wipe (damp or soaked wet with water). The wipe can be applied against the marking with light shear force, e.g., after a few wipes/rubs, or <5 wipes, or <10 wipes, or <20 wipes., to slightly stronger shear force as in repeated rubs for <5 min, or <3 min, or <1 min, or >30 sec.
In embodiments markings can be erased from the marking surface with a wipe moist with a cleaning fluid after wiping for <5 min, or <2 min, or <1 min.
For some of marking materials, e.g., Indian ink, oil-based paint, or print markings made by printer ink, if >50% of the marking cannot be removed with water, then other cleaning fluids, e.g., isopropyl alcohol (IPA) or rubbing alcohol (70% IPA), etc. can be applied to remove the rest of the marking from the marking surface within a few minutes of rubbing. In embodiments with the marking material being a nail polish, the marking can be removed by rubbing with a wipe soaked moist with acetone.
In embodiments, the cleaning fluid is selected depends on a drying time (i.e., time elapsed since the marking with the marking material) of the marking material on the marking surface. For example, markings made with an ink of a ball point pen can be easily removed from the marking surface by using water, when a wipe moist with water is rubbed on the marking surface within a first predetermined duration, e.g., a few hours, of making on the marking surface. However, a different cleaning fluid, e.g., rubbing alcohol or IPA, etc., can be used instead of or in addition to water to quickly erase or completely remove dried out marking made, e.g., after 24 hours or after a few days since the surface was first marked, and provided the marking cannot be quickly removed with water.
When the cleaning fluid is water in embodiments, at least 50%, or at least 70%, or at least 80%, or at least 90% or up to 100% of the marking material is erased from the marking surface with the wipe moist with water after wiping for <5 min, or <3 min, or <1 min.
(Properties of Reusable Marking Surface Comprising Sulfonated Block Copolymer)
In embodiments, the outer layer containing the substrate (i.e., the marking surface) coated with the sulfonated block copolymer is characterized as being transparent. Transparency refers to optical clarity, meaning that enough light is transmitted through to allow visualization through the film by an observer. Although some haze or coloration can be present, such haze or coloration does not substantially interfere with visualization for a marking surface. In embodiments, the outer layer has a transmittance of >90%, or >94%; or clarity of >99% or >99.5%; or a haze value of <1.5%, or <1.25%, or <1.0%, or <0.75%. Haze can be measured according to ASTM D-1003.
In embodiments, the outer layer containing the sulfonated block copolymer has a surface pH of <5, or <3.0, or <2.5, or <2.25, or <2.0, or <1.80.
The marking surface having the outer layer containing the sulfonated block copolymer is erasable, meaning that >50%, or >60%, or >70%, or >80%, or >90%, or up to 100% of markings (or pre-existing ink) on the marking surface is removed after the first wiping or rubbing the marking surface for <5 min, or <2 min, or <1 min, or >10 sec. with a wipe that is moist/saturated with the cleaning fluid.
In addition to the erasable characteristics, the marking surface as coated with the sulfonated block copolymer works effectively in destroying/inactivating >90% of microbes (1 log10 CFU or colony forming unit), or >95%, or >99% (2 log10 CFU), or at least 99.5%, or at least 99.9% (3 log10 CFU) of microbes in <30 min of exposure, or <5 min in contact with the marking surface, as disclosed in Published Patent No. AU2021102026A4, incorporated by reference. The microbes include but are not limited to MRSA (Methicillin-resistant Staphylococcus aureus), vancomycin-resistant Enterococcus faecium, X-MulV, PI-3, SARS-CoV-2, carbapenem-resistant Acinetobacter baumannii, and influenza A virus. In embodiments, the erasable marking surface is effective in killing microbes including Staphylococcus aureus, Escherichia coli, Staphylococcus albus, Escherichia coli, Rhizoctonia solani, Fusarium oxysporum, and the like. The erasable marking surface remains effective in killing microbes for extended use, even after 4 hrs., or after 12 hrs., or at least 24 hrs., or for at least 48 hrs.
In tests simulating cleaning or wiping an erasable marking surface containing an outer layer having a sulfonated block copolymer, the layer retains its antimicrobial effectiveness after 2400 cleaning or abrasion cycle, representing 200 days (>6 months) in use with 6 cleaning sessions per day (with 4 rubbing motions per session using alcohol and/or quaternary ammonium compound cleaners).
(Applications)
The erasable and reusable marking surface can be used for typical writing instruments, e.g., notebooks, artist easels, sketches, etc., which in the prior art made with papers to be discarded or recycled after filled with marking or writing. It can also be particularly useful for making erase boards, writing boards, etc., in conference rooms, meeting rooms, etc., for use with practically any type of writing instruments, and without the need for special ink or pens as in the prior art writing boards.
It can be appreciated that with the use of the sulfonated block copolymer as the outer layer, there are other applications for reusable or erasable marking surfaces, e.g., skateboards, exhibition displays, temporary building wall art, street art, etc., where temporary artistic sketches or paintings can be provided and removed after display for a certain period. Further, due to the antimicrobial/self-sterilizing characteristics of the sulfonated block copolymer, the reusable marking surface has applications in medical facilities, e.g., medical pouches, clip boards, notepads for surgical rooms, examination rooms, etc. The marking surface can also be useful in public facilities with repeat exposures to germs, requiring frequent cleaning, e.g., student desks with writeable surfaces, wallpapers for nurseries, or daycare centers, etc.
The following examples are intended to be non-limiting.
In all examples, the marking surface is a laminate from Kraton Corporation, having one surface (one side) being coated with a sulfonated block copolymer, on a substrate comprising a microporous polyethylene film thermally bonded to a polyethylene/PET bicomponent nonwoven (“Kraton Marking Surface,” or KMS pages). The sulfonated block copolymer is a poly(p-tert-butylstyrene-b-styrenesulfonate-b-p-tert-butylstyrene), with IEC of about 1 meg/q.
In this example, erasability of marking surfaces with various types of marking materials is illustrated as shown in the figures.
This example illustrates embodiments of marking surfaces printed with inkjet (Epson) inks, and with the surfaces being re-used for a 2nd print.
In this example, erasability of marking surfaces with various types of paints is illustrated.
Other examples are illustrated in
As shown in
As used herein, the term “comprising” means including elements or steps that are identified following that term, but any such elements or steps are not exhaustive, and an embodiment can include other elements or steps. Although the terms “comprising” and “including” have been used herein to describe various aspects, the terms “consisting essentially of” and “consisting of” can be used in place of “comprising” and “including” to provide for more specific aspects of the disclosure and are also disclosed.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained. It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural references unless expressly and unequivocally limited to one referent. As used herein, the term “includes” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.
Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed disclosure belongs. the recitation of a genus of elements, materials, or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof.
The patentable scope is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. To an extent not inconsistent herewith, all citations referred to herein are hereby incorporated by reference.
This application claims benefit to U.S. provisional application No. 63/267,731, filed on Feb. 9, 2022, which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63267731 | Feb 2022 | US |
