US20200308761A1

US20200308761A1 - Fabric printable medium

Info

Publication number: US20200308761A1
Application number: US16/770,735
Authority: US
Inventors: Xiaoqi Zhou; Xulong Fu
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2018-03-19
Filing date: 2018-07-31
Publication date: 2020-10-01
Also published as: WO2019182633A1; US11325410B2; WO2019182558A1; US20210070085A1

Abstract

A fabric printable medium includes a fabric base substrate, which includes yarn strands and voids among the yarn strands. The fabric printable medium further includes a finishing coating attached to the yarn strands of the fabric base substrate to form coated yarn strands. The finishing coating includes polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C. The fabric printable medium has pore spaces among the coated yarn strands that coincide with at least some of the voids of the fabric base substrate.

Description

BACKGROUND

Inkjet printing technology has expanded its application to large format high-speed, commercial and industrial printing, in addition to home and office usage, because of its ability to produce economical, high quality, multi-colored prints. This technology is a non-impact printing method in which an electronic signal controls and directs droplets or a stream of ink that can be deposited on a wide variety of medium substrates. Inkjet printing technology has found various applications on different substrates including, for examples, cellulose paper, metal, plastic, fabric and the like. The substrate plays a key role in the overall image quality and permanence of the printed images. Textile printing has various applications including the creation of signs, banners, artwork, apparel, wall coverings, window coverings, upholstery, pillows, blankets, flags, tote bags, etc. It is a growing and evolving area and is becoming a trend in the visual communication and decoration market. As the area of textile printing continues to grow and evolve, the demand for new print mediums increases.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of examples of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to similar, though perhaps not identical, components. For the sake of brevity, reference numerals or features having a previously described function may or may not be described in connection with other drawings in which they appear.

FIG. 1A is a schematic and cross-sectional view of an example of the fabric printable medium disclosed herein. FIG. 1B is an enlarged, cut-away top view of an example of coated yarn strands of the fabric printable medium of FIG. 1A.

FIG. 2 is a flow diagram illustrating an example of a method for forming an example of the fabric printable medium.

FIG. 3 is a flow diagram illustrating an example of a printing method disclosed herein.

DETAILED DESCRIPTION

When printing on fabric substrates, challenges exist due to the specific nature of the fabric. Some fabrics, for instance, can be highly absorptive of aqueous inks, which can diminish color characteristics of the printed image. Other fabrics, such as some synthetic fabrics, can be crystalline, and thus are less absorptive of aqueous inks. When the inks are not adequately absorbed, performance issues can result. These characteristics (e.g., diminished color, ink bleed) can result in poor image quality on the respective fabrics. Additionally, black optical density, color gamut, and sharpness of the printed images can be affected, and are often worse on fabrics when compared to images printed on cellulose paper or other media types. Durability, such as scratch resistance, rub resistance, folding resistance, and wind resistance, is another concern when printing on fabric, particularly when pigmented inks are used and when the fabric is to be used in an outdoor application.
The fabric printable medium disclosed herein is a printable recording medium (or printable media) that generates high quality printed images that also exhibit outstanding print durability, in terms of scratch resistance, rub resistance, folding resistance, and wind resistance.
By “scratch resistance” and “rub resistance”, it is meant herein that the image printed on the medium is resistant to degradation as a result of scuffing or abrasion. The term “scuffing” means that something blunt is dragged across the printed image (like brushing fingertips along printed image), or the medium can fold over on itself exposing the image to repeated surface interactions. Scuffing can result in damage to the printed image. Scuffing does not usually remove colorant but it may change the gloss of the area that was scuffed. The term “abrasion” means that force is applied to the printed image generating friction, usually from another object (such as a coin, fingernail, etc.), which can result in wearing, grinding or rubbing away of the printed image. Abrasion is correlated with removal of colorant (i.e., with a loss in optical density (OD)). By “folding resistance”, it is meant herein that the image printed on the medium is resistant to degradation as a result of being folded and being exposed to weight while in the folded state. The fabric printable medium may be folded when stored and/or shipped. During storage and/or shipping, the folded medium may also be exposed to the weight of another object that is placed on top of the folded medium. The combination of the fold and the weight can cause the printed image to crack or experience colorant removal at or near the fold. By “wind resistance”, it is meant herein that the image printed on the medium is resistant to degradation as a result of being exposed to wind. When used outdoors or in drafty indoor conditions, the fabric printable medium exposed to flapping, which can cause the medium to rub against itself or another object. These conditions can cause the printed image to experience scuffing or, in worse cases, colorant removal and/or can cause the material of the fabric base substrate to shred.
The present disclosure relates to a fabric printable medium, comprising a fabric base substrate including yarn strands and voids among the yarn strands; a finishing coating, attached to the yarn strands of the fabric base substrate, to form coated yarn strands, the finishing coating including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and pore spaces, among the coated yarn strands, that are coinciding with at least some of the voids of the fabric base substrate. The present disclosure also relates to a method for forming the fabric printable medium as described therein and to the printing method using it.
The fabric printable medium disclosed herein includes a finishing coating on yarn strands of a fabric base substrate. The finishing coating contributes to the durability of i) the medium itself (e.g., in terms of wind resistance) and ii) the image(s) printed thereon, and also contribute to the quality of the printed image(s). In some examples, the fabric printable medium also includes a waterproof coating composition. Such waterproof coating composition is positioned at the back of the fabric printable medium (i.e., at the side of the medium that does not receive ink). The waterproof coating can also contribute to durability and image quality.
Referring now to FIGS. 1A and 1B, an example of the fabric printable medium 10 and an enlarged, cut-away view of coated yarn strands 15 of the fabric printable medium 10 are respectively depicted. The fabric printable medium 10 comprises a fabric base substrate 12 including yarn strands 14 and voids 16 among the yarn strands 14; a finishing coating 22 attached to the yarn strands 14 of the fabric base substrate 12 to form coated yarn strands 15, the finishing coating 22 including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and pore spaces 24 among the coated yarn strands 15 and coinciding with at least some of the voids 16 of the fabric base substrate 12. As shown in phantom in FIG. 1A, some examples of the fabric printable medium 10 also include a waterproof coating 26 attached to a back-side 20 the coated yarn strands 15.
Fabric Base Substrate
The fabric printable medium 10 includes the fabric base substrate 12, upon the yarn strands 14 of which the finishing coating 22 is applied. A waterproof coating 26 may also be applied on the coated yarn strands 15. As such, the fabric base substrate 12 is a supporting substrate, in part because it carries the coatings 22, 26 and the image (not shown) that is to be printed.
The fabric base substrate 12 includes yarn strands 14 and voids 16 among the yarn strands 14. As used herein, “yarn” and “yarn strand” refer to a plurality of threads. In an example, the plurality of threads are spun together to form strands. As will be described in more detail below, the strands may have a fabric structure or may be in the form of fibers. The yarn strands 14 may include natural threads and/or synthetic threads. Natural threads that may be used include wool, cotton, silk, linen, jute, flax or hemp. Additional threads that may be used include rayon threads or thermoplastic aliphatic polymeric threads derived from renewable resources, such as cornstarch, tapioca products, or sugarcanes. These additional threads can also be referred to as natural threads.
Synthetic threads that may be used include polymeric threads. Examples of polymeric threads include polyvinyl chloride (PVC) threads, or PVC-free threads made of polyester, polyamide, polyimide, polyacrylic, polypropylene, polyethylene, polyurethane, polystyrene, polyaramid (e.g., Kevlar®), polytetrafluoroethylene (Teflon®) (both trademarks of E. I. du Pont de Nemours Company), fiberglass, polytrimethylene, polycarbonate, polyethylene terephthalate, or polybutylene terephthalate. It is to be understood that the term “PVC-free” means no polyvinyl chloride (PVC) polymer or vinyl chloride monomer units in the substrate 12. Synthetic threads may also be modified threads from the above-listed polymeric threads. The term “modified threads” refers to polymeric resins that have been made into polymeric threads, where the polymeric threads (one example of the yarn strands 14) and/or the substrate 12 as a whole have undergone a chemical or physical process. Examples of the chemical or physical process include a copolymerization with monomers of other polymers, a chemical grafting reaction to contact a chemical functional group with one or both the polymeric threads and a surface of the substrate 12, a plasma treatment, a solvent treatment (e.g., acid etching), and/or a biological treatment (e.g., an enzyme treatment or antimicrobial treatment to prevent biological degradation).
In some examples, the individual threads of a given yarn strand 14 may be made up of the same type of thread (e.g., natural or synthetic). In other examples, the individual threads of a given yarn strand 14 may be composites or blends of natural and synthetic materials. The natural and synthetic materials may be blended during yarn formation and/or fabric weaving and/or knitting. The weight ratio of natural to synthetic material may vary, and may range anywhere from about 1:99 to about 99:1.
It is to be further understood that different yarn strands 14 may be used together in the fabric base substrate 12. In some examples, the yarn strands 14 used in the fabric base substrate 12 include a combination or mixture of two or more from the above-listed natural threads, a combination or mixture of any of the above-listed natural threads with another natural thread or with a synthetic thread, or a combination or mixture of two or more from the above-listed natural threads with another natural thread or with a synthetic thread. In other examples, the yarn strands 14 used in the fabric base substrate 12 include a combination or mixture of two or more from the above-listed synthetic threads, a combination or mixture of any of the above-listed synthetic threads with another synthetic thread or with a natural thread, or a combination or mixture of two or more from the above-listed synthetic threads with another synthetic thread or with a natural thread. As such, some examples of the fabric base substrate 12 include one yarn 14 containing natural threads and another yarn 14 containing synthetic threads.
When the fabric base substrate 12 includes yarn strands 14 of synthetic threads, the amount of the synthetic yarn strands may range from about 20 wt % to about 90 wt % of the total amount of yarn strands 14. When the fabric base substrate 12 includes yarn 14 of natural threads, the amount of the natural yarn strands may range from about 10 wt % to about 80 wt % of the total amount of yarn strands 14. When the fabric base substrate 12 includes yarn strands 14 of synthetic threads and yarn strands 14 of natural threads (e.g., as a woven structure), the amount of the synthetic yarn strands may be about 90 wt % of the total amount of the yarn strands 14 in the fabric base substrate 12, while the amount of the natural yarn strands may be about 10 wt % of the total amount of the yarn strands 14 in the fabric base substrate 12.
The yarn strands 14 may be configured to have a fabric structure. As used herein, the term “fabric structure” is intended to mean a structure having warp and weft that is one of woven, non-woven, knitted, tufted, crocheted, knotted, or pressured, for example. The terms “warp” and “weft” refer to weaving terms that have their ordinary meaning in the textile arts, and as used herein, e.g., warp refers to lengthwise or longitudinal yarns on a loom, while weft refers to crosswise or transverse yarns on a loom.
In an example, the fabric base substrate 12 can be a woven fabric where warp yarns and weft yarns are mutually positioned at an angle of about 90° (see, e.g., FIG. 1B). This woven fabric may include fabric with a plain weave structure, fabric with twill weave structure where the twill weave produces diagonal lines on a face of the fabric, or a satin weave. In another example, the fabric base substrate 12 can be a knitted fabric with a loop structure including one or both of warp-knit fabric and weft-knit fabric. The weft-knit fabric refers to loops of one row of fabric that are formed from the same yarn strands 14. The warp-knit fabric refers to every loop in the fabric structure that is formed from a separate yarn strands 14, mainly introduced in a longitudinal fabric direction. In a specific example, the fabric base substrate 12 is woven, knitted, non-woven or tufted and comprises yarn strands 14 selected from the group consisting of wool, cotton, silk, rayon, thermoplastic aliphatic polymers, polyesters, polyamides, polyimides, polypropylene, polyethylene, polystyrene, polytetrafluoroethylene, fiberglass, polycarbonates polytrimethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, and combinations thereof.
The yarn strands 14 may also be configured as fibers or filaments. In these examples, the fabric base substrate 12 is a non-woven product. The plurality of yarn fibers or filaments may be bonded together and/or interlocked together by a chemical treatment process (e.g., a solvent treatment), a mechanical treatment process (e.g., embossing), a thermal treatment process, a treatment including another substance (such as an adhesive), or a combination of two or more of these processes. It is to be understood that the configurations of the yarn strands 14 discussed herein include voids 16 among the yarn strands 14. As such, the fiber base substrate 12 is porous. An example of the fiber base substrate 12 is shown in hidden line in FIG. 1B, including the yarn strands 14 and the voids 16. The void 16 encompasses the entire space (extending in the X, Y, and Z directions) between adjacent yarn strands 14. Thus, the shape and dimensions of each void 16 depends upon the yarn strand 14 and its configuration (e.g., woven, non-woven, etc.).
Examples of the fiber base substrate 12 may be subjected to pre-finishing treatment(s), such as desizing, scouring, bleaching, washing, a heat setting process, and/or treatment with various additives. Examples of suitable additives include one or more of colorant (e.g., pigments, dyes, tints), antistatic agents, brightening agents, nucleating agents, antioxidants, UV (ultraviolet light) stabilizers, fillers, and lubricants. As an example, the fabric base substrate 12 may be pre-treated in a solution containing the substances listed above before applying the coating compositions 22, 26. The additives and/or pre-treatments may be included to improve various properties of the fabric base substrate 12. The amount of any given additive included in the fiber base substrate 12 depends upon the additive, but may range from about 0.1 wt % to about 5 wt %.
In some examples, the fabric base substrate 12 has a basis weight that ranges from about 50 gsm to about 400 gsm. In some other examples, the basis weight of the fabric base substrate 12 can range from about 100 gsm to about 300 gsm.
Based on the discussion of the fabric base substrate 12, it is to be understood that the fabric base substrate 12 may be any textile, cloth, fabric material, fabric clothing, or other fabric product or finished article (e.g., blankets, tablecloths, napkins, bedding material, curtains, carpet, shoes, etc.) that includes the yarn strands 14 and the voids 16 among the yarn strands 14. It is to be further understood that the fabric base substrate 12 does not include materials commonly known as paper (even though paper can include multiple types of natural and synthetic fibers or mixture of both types of fibers). Paper may be defined as a felted sheet, roll or other physical form that is made of various plant fibers (like trees or mixture of plant fibers), in some instances with synthetic fibers, which are laid down on a fine screen from a water suspension.
Finishing Coating and Pore Spaces
The fabric printable medium 10 includes a finishing coating 22. The finishing coating 22 is not a continuous layer across the surface of the fabric base substrate 12, but rather is attached to the surface of the yarn strands 14 to form the coated yarn strands 15. The finishing coating 22 is coated on surfaces of the yarn strands 14 throughout a depth of the fabric base substrate 12.
The fabric printable medium 10 also includes pore spaces 24 among the coated yarn strands 15. The pore spaces 24 coincide with at least some of the voids 16 of the fabric base substrate 12. By “coincide”, it is meant that the pore spaces 24 at least substantially align with the voids 16, so that at least some of the voids 16 of the fabric base substrate 12 remain at least partially open to air flow (i.e., are not covered by the finishing coating 22). This is shown in FIG. 1B. As depicted, the finishing coating 22 adheres to the surface of the yarn strands 14 to form coated yarn strands 15 but does not completely cover the voids 16. The space that remains between the pieces of the yarn strands 14 coated with the finishing coating 22 (i.e., the coated yarn strands 15) is referred to as the pore space 24. As shown in FIG. 1B, the pore space 24 may have a slightly different shape and/or slightly smaller dimensions than the void 16 with which it coincides.
In examples, the degree of coverage of the finishing coating 22 is such that at least some of the initial porosity (voids 16) of the fabric base substrate 12 is maintained after the finishing coating 22 is applied to form the coated yarn strands 15. In other words, at least a portion of at least some of the voids 16 remains open after the finishing coating 22 is applied to the yarn strands 14. In an example, at least 33% of the original porosity is maintained after the finishing coating 22 is applied (i.e., 1 pore space 24 is formed for every 3 voids 16). In other words, at least 33% of the voids of the fabric base substrate coincide with the pore spaces 24 of the finishing coating 22. In another example, at least 50% of the original porosity is maintained after the finishing coating 22 is applied (i.e., 1 pore space 24 is formed for every 2 voids 16). In still another example, at least 66% of the original porosity is maintained after the finishing coating 22 is applied (i.e., 2 pore spaces 24 are formed for every 3 voids 16). In yet another example, 100% of the original porosity is maintained after the finishing coating 22 is applied (i.e., 1 pore space 24 is formed for every 1 void 16). The porosity (e.g., voids 16 before coating and pore spaces 24 after coating) may be measured by testing the air flow (mL/min) through the medium 10 per Tappi method T526 (e.g., using a Hagerty Technologies instrument (from Technidyne)) or per Tappi method T-555 (e.g., using a Parker Print-Surf instrument (from Testing Machines, Inc.)), or with another like method and/or instrument).
As shown in FIG. 1A throughout the fabric base substrate 12, the finishing coating 22 covers the surfaces of the yarn strands 14 through the matrix of the fabric base substrate 12. Throughout the depth, at least some of the voids 16 and pore spaces 24 remain open. It is to be understood that this figure represents the coating 22 on the yarn surfaces (i.e., the coated yarn strands 15) and also represents the pore spaces 24 that are defined between the coated yarn strands 15.
The finishing coating 22 provides the fabric base substrate 12 with ink receiving properties and durability, while also maintaining the flexibility of the fabric base substrate 12. The characteristics of the finishing coating 22 are due, in part, to a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C. in the finishing coating 22. The polymeric compound network is i) capable of holding applied ink at the image-side 18 (which improves image quality), ii) mechanically strong (which contributes to improved durability), and iii) capable of being applied to form the pore spaces 24 (which contributes to maintaining the flexibility of the fabric base substrate 12).
The finishing coating 22 comprises the polymeric compounds and/or the mixture of the polymeric compounds. The glass transition temperature (Tg) of the polymeric compounds, or the glass transition temperature of polymeric compounds in the mixture is less than 15° C. By “the glass transition temperature (Tg) of polymeric compounds in the mixture is less than 15° C.”, it is meant herein that the majority or nearly all polymeric compounds present in the mixture will have a glass transition temperature that is less than 15° C.
In some examples, the glass transition temperature (Tg) of the polymeric compounds, or the glass transition temperature of polymeric compounds in the mixture is less than 5° C. In some other examples, the glass transition temperature (Tg) of the polymeric compounds, or the glass transition temperature of polymeric compounds in the mixture is less than 0° C.
Glass transition temperature (Tg) of polymeric compounds can be measured using differential scanning calorimetry according to ASTM D6604: Standard Practice for Glass Transition Temperatures of Hydrocarbon Resins by Differential Scanning calorimetry. Differential scanning calorimetry can be used to measure the heat capacity of the polymer across a range of temperatures. The heat capacity can jump over a range of temperatures around the glass transition temperature. The glass transition temperature itself can be defined as the temperature where the heat capacity is halfway between the initial heat capacity at the beginning of the jump and the final heat capacity at the end of the jump.
In some example, the finishing coating 22 includes a polymeric compound having a glass transition temperature is less than 15° C. that is individually crosslinked. In some example, the polymeric compound compounds are selected from the group consisting of polyacrylate, polyurethane, vinyl-urethane, acrylic urethane, polyurethane-acrylic, polyether polyurethane, polyester polyurethane, polycaprolactam polyurethane, polyether polyurethane, polyamine, and a combination thereof.
In some examples, the polymeric compounds used to make finishing coating 22 include rubber emulsion/latex. The types of rubber emulsion/latex include, but are not limited to, natural Rubber (NR) or linear polymer of polyisoprene, Styrene Butadiene Rubber (SBR), Nitrile Rubber or copolymer of acrylonitrile and butadiene, Neoprene Rubber or polychloroprene, EPDM Rubber or copolymer of ethylene, propylene with dienes such as dicyclopentadiene (DCPD), ethylidene norbornene (ENB), and vinyl norbornene (VNB), Butyl Rubber (BR), or copolymer of isobutylene with isoprene, polychloroprene rubber, polysiloxane rubber and chloro-sulphonated polyethylene/rubber.
In one example, the polymeric compounds can include a polyacrylate (i.e., a polyacrylate based polymer). Examples of polyacrylates include polymers made by hydrophobic addition monomers, such as C1-C12 alkyl acrylates, carboxylic containing monomers (e.g., acrylic acid, methacrylic acid), vinyl ester monomers (e.g., vinyl acetate, vinyl propionate, vinyl benzoate, vinyl pivalate, vinyl-2-ethylhexanoate, vinyl versatate, etc.), vinyl benzene monomer, C1-C12 alkyl acrylamide and methacrylamide (e.g., t-butyl acrylamide, sec-butyl acrylamide, N,N-dimethylacrylamide, etc.), crosslinking monomers (e.g., divinyl benzene, ethylene glycol dimethacrylate, bis(acryloylamido)methylene, etc.), and combinations thereof. As specific examples, polymers made from the polymerization and/or copolymerization of alkyl acrylate, alkyl methacrylate, and/or vinyl esters may be used. Any of the listed monomers (e.g., hydrophobic addition monomers, aromatic monomers, etc.) may be copolymerized with styrene or a styrene derivative. As specific examples, polymers made from the copolymerization of alkyl acrylate, alkyl methacrylate, and/or vinyl esters, with styrene or styrene derivatives may also be useful.
In some examples, the polymeric compound is a polyacrylate based polymer having a glass transition temperature less than 15° C. In some other examples, the polymeric compound is a polyacrylate based polymer having a glass transition temperature less than 5° C. In some examples, the polymeric compound is a polyacrylate based polymer having a glass transition temperature less than 0° C.
In one example, the polymeric compound can include a polyurethane polymer. The polyurethane polymer, can be formed by reacting an isocyanate with a polyol. Example isocyanates used to form the polyurethane polymer can include toluene di-isocyanate, 1,6-hexamethylenedii socyanate, diphenylmethanedi-isocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, 1,4-cyclohexyldiisocyanate, p-phenylenediisocyanate, 2,2,4(2,4,4)-trimethylhexamethylenediisocyanate, 4,4′-dicychlohexylmethanediisocyanate, 3,3′-dimethyldiphenyl, 4,4′-diisocyanate, m-xylenediisocyanate, tetramethylxylenediisocyanate, 1,5-naphthalenediisocyanate, dimethyl-triphenyl-methane-tetra-isocyanate, triphenyl-methane-tri-isocyanate, tris(iso-cyanate-phenyl)thiophosphate, and combinations thereof. Commercially available isocyanates can include Rhodocoat® WT 2102 (available from Rhodia AG), Basonat® LR 8878 (available from BASF), Desmodur® DA, and Bayhydur® 3100 (Desmodur® and Bayhydur® are available from Bayer AG). Example polyols used to form the polyurethane polymer can include 1,4-butanediol, 1,3-propanediol, 1,2-ethanediol, 1,2-propanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, cyclo-hexane-dimethanol, 1,2,3-propanetriol, 2-ethyl-2-hydroxymethyl-1,3-propanediol, and combinations thereof.
In some examples, the isocyanate and the polyol can have less than three functional end groups per molecule. In another example, the isocyanate and the polyol can have less than five functional end groups per molecule. In yet another example, the polyurethane can be formed from a polyisocyanate having at least two isocyanate functionalities (—NCO) per molecule and at least one isocyanate reactive group (e.g., such as a polyol having at least two hydroxyl or amine groups). Example polyisocyanates can include diisocyanate monomers and oligomers. The self-crosslinked polyurethane polymer can also be formed by reacting an isocyanate with a polyol, where both isocyanates and polyols have an average of less than three end functional groups per molecule so that the polymeric network is based on a linear polymeric chain structure. In one example, the polyurethane can be prepared with a NCO/OH ratio ranging from about 1.2 to about 2.2. In another example, the polyurethane can be prepared with a NCO/OH ratio ranging from about 1.4 to about 2.0. In yet another example, the polyurethane can be prepared using an NCO/OH ratio ranging from about 1.6 to about 1.8.
In one example, the weight average molecular weight of the polyurethane polymeric compound can range from about 20,000 Mw to about 200,000 Mw as measured by gel permeation chromatography. In another example, the weight average molecular weight of the polyurethane polymeric compound can range from about 40,000 Mw to about 180,000 Mw as measured by gel permeation chromatography. In yet another example, the weight average molecular weight of the polyurethane polymeric compound can range from about 60,000 Mw to about 140,000 Mw as measured by gel permeation chromatography.
The polyurethane may be aliphatic or aromatic. Some specific examples of commercially available aliphatic waterborne polyurethanes include Sancure® 1514, Sancure® 1591, Sancure® 2260, and Sancure® 2026 (all of which are available from Lubrizol Inc.). Some specific examples of commercially available castor oil-based polyurethanes include Alberdingkusa® CUR 69, Alberdingkusa® CUR 99, and Alberdingkusa® CUR 991 (all from Alberdingk Boley Inc.).
Other examples of the polyurethane polymeric compound that can be used include vinyl-urethane, acrylic urethane, polyurethane-acrylic, polyether polyurethane, polyester polyurethane, polycaprolactam polyurethane, or polyether polyurethane. Any of these examples may be aliphatic or aromatic. For example, the polyurethane may include aromatic polyether polyurethanes, aliphatic polyether polyurethanes, aromatic polyester polyurethanes, aliphatic polyester polyurethanes, aromatic polycaprolactam polyurethanes, or aliphatic polycaprolactam polyurethanes.
In some examples, the polymeric compound that can be used include vinyl-urethane, acrylic urethane, polyurethane-acrylic is formed by using vinyl-urethane hybrid copolymers or acrylic-urethane hybrid copolymers. In yet some other examples, the polymeric network(s) includes an aliphatic polyurethane-acrylic hybrid polymer. Representative commercially available examples of the chemicals which can form an acrylic-urethane polymeric network include NeoPac® R-9000, R-9699 and R-9030 (from Zeneca Resins) or HYRBIDUR™ 570 (from Air Products and Chemicals). In still another example, the polymeric network includes an acrylic-polyester-polyurethane polymer, such as Sancure® AU 4010 (from Lubrizol Inc.).
In some examples, any example of the polymeric compound can include a polyether polyurethane. Representative commercially available examples of the chemicals which can form a polyether-urethane polymeric network include Alberdingkusa® U 205, Alberdingkusa® U 410, and Alberdingkusa® U 400N (all from Alberdingk Boley Inc.), or Sancure®861, Sancure® 878, Sancure® 2310, Sancure® 2710, Sancure® 2715, or Avalure® UR445 (equivalent copolymers of polypropylene glycol, isophorone diisocyanate, and 2,2-dimethylolpropionic acid, having the International Nomenclature Cosmetic Ingredient name “PPG-17/PPG-34/IPDI/DMPA Copolymer” (all from Lubrizol Inc.).
In other examples, any example of the polymeric compound can include a polyester polyurethane. Representative commercially available examples of the chemicals which can form a polyester-urethane polymeric network include Alberdingkusa® 801, Alberdingkusa® u 910, Alberdingkusa® u 9380, Alberdingk® u 2101 and Alberdingk® u 420 (all from Alberdingk Boley Inc.), or Sancure® 815, Sancure® 825, Sancure® 835, Sancure® 843c, Sancure® 898, Sancure® 899, Sancure® 1301, Sancure® 1511, Sancure® 2026c, Sancure® 2255, and Sancure® 2310 (all from Lubrizol, Inc.). In still other examples, any example of the polymeric compound can include a polycarbonate polyurethane. Examples of polycarbonate polyurethanes include Alberdingkusa® U 933 and Alberdingkusa® U 915 (all from Alberdingk Boley Inc.).
In some examples, the finishing coating 22 includes polymeric compounds that can represent from about 80 wt % to about 99 wt % of the total weight of the finishing coating 22.
The finishing coating composition used to form the finishing coating 22 may include, in addition to the polymeric compounds and water, processing aids, such as rheology control agent(s), surfactant(s) (e.g., BYK-DYNWET 800 from BYK), pH adjuster(s), defoamer(s), optical property modifier(s) (e.g., dye, optical brightening agents (OBA)), or combinations thereof.
In some examples, the finishing coating composition contains a rheology control agent. As rheology control agent it is meant herein a physical gelling compound is capable to make a physical network. The physical gelling compound will be able to generate various physical force, or physical bonding, to form a gel-like solution. By “gel-like solution”, it is meant herein a solution system that has a low solids content, (i.e. from about 5 to about 30 wt %) but very high viscosity (i.e. above 15,000 cps at 30 rpm when measure by a Brookfield viscometer, at 25° C.), at low share stress and that will behave like a non-flowable semi-solids gel. The rheology control agent are high molecular weight polymers, i.e. having a molecular weight ranging from about 300,000 to about 1,000,000. The rheology control agent can be copolymers of acrylates, copolymers with acrylate-based polyelectrolyte backbone, copolymers with polyester backbone, or copolymers with polyurethane based copolymer backbone. The rheology control agent can also be a copolymer with polyester backbone. In some examples, the rheology control agent is selected from the group consisting of copolymers of acrylates, copolymers with acrylate-based polyelectrolyte backbone, copolymers with polyester backbone, and copolymers with polyurethane based copolymer backbone.
Examples of such rheology control agent include Acusol®810A, Acusol L®830, Acusol®835, ACUSOL® 842 (supplied by Rohm Haas/Dow Co); or Alcogum® L11, Alcogum® L12, Alcogum® L51, Alcogum® L31 and Alcogum® L52 (available from Akzo Nobel Co). Still another example of a suitable physical networking agent is hydroxyethyl cellulose. An example that is commercially available is Tylose HS30000 (from SE Tylose GmbH & Co. KG).
In some other examples, the finishing coating composition contains surfactant. It is to be understood that any of the chemical components in the finishing coating 22, and the finishing coating composition used to form the finishing coating 22, are compatible. In this example, “compatible” means that the components of the finishing coating composition are miscible without phase separation or without forming a layered composition at room temperature. As such rheology, any solid particles, such as fillers, flame retardants, and lubricant wax are excluded from the finishing coating composition. The amount of any given additive included in the finishing coating 22 depends upon the additive but may range from about 0.1 wt % to about 5 wt % of a total weight of the finishing coating 22.
In examples, the finishing coating 22 has a dry coat-weight of 6 gsm (grams per square meter) or less, such as 4.5 gsm or less, or 2.5 gsm or less. It is to be understood that the gsm of the finishing coating 22 is greater than zero.
Waterproof Coating
As shown in FIG. 1A, some examples of the fabric printable medium 10 further comprise a waterproof coating 26 on the back-side 20 of the coated yarn strands 15. In one example, the waterproof coating 26 may be porous, and thus may be similar to the finishing coating 22 in that it coats the coated yarn strands 15 but allows some of the pore spaces 24 at the back-side 20 to remain open. The average pore size of these pore spaces may be similar to the pore spaces 24, and may depend, in part, upon the coat-weight of the waterproof coating 26. When the waterproof coating 26 has a coat-weight ranging from about 1 gsm to about 2 gsm, the at least some of the pore spaces 24 may remain open. In another example, the waterproof coating 26 may be a continuous filmed layer that covers the coated yarn strands 15 and the pore spaces 24 at the back-side 20 of the coated yarn network 11. When the waterproof coating 26 has a coat-weight greater than 2 gsm, the waterproof coating 26 may be continuous (i.e., the pore spaces 24 are covered).
The waterproof coating 26 provides the back of the fabric printable medium 10 with a low enough surface energy to generate a waterproof function. In an example, the waterproof coating 26 has a surface energy of less than 40 mJ/m2. In another example, the surface energy of the waterproof coating 26 ranges from about 32 mJ/m2 to about 36 mJ/m2. In an example, the waterproof coating 26, and thus the back of the fabric printable medium 10, has a contact angle greater than 60°. In another example, the contact angle of the waterproof coating 26 ranges from about 66° to about 90°. The surface energy and the contact angle contribute to the waterproof function, which keeps the fabric printable medium 10 from absorbing water, e.g., when exposed to outdoor conditions, such as rain or snow. As such, the waterproof coating 26 improves the weather resistance of the fabric printable medium 10. The surface energy (y) can be measured by a Force Tensiometer (such as K11 by Kr{umlaut over (υ)}ss, North Carolina).
When present, the waterproof coating 26 may have dry coat-weight ranging from about 0.5 gsm to about 5 gsm, or from about 1 to about 3 gsm.
As shown in FIG. 1A, in some examples, at the back-side 20, the waterproof coating 26 is on a surface of the coated yarn strands 15 and does not penetrate into a depth of the coated yarn strands 15, but rather covers the pore spaces 24. In some instances, it is desirable for the waterproof coating 26 to remain on the back-side 20 so that the waterproof coating 26 does not interfere with the ink receiving function of the finishing coating 22 or deleteriously affect the flexibility and softness of the fabric base substrate 12.
The waterproof coating 26 includes a physical networking agent to help retain the waterproof coating 26 on the back-side 20 (without substantial penetration into the pore spaces 24 among the coated yarn strands 15) and also includes a waterproof agent to obtain the desired surface energy on the back of the medium 10.
The physical networking agent can be a chemical that promotes physical bonding with the waterproof agent to form a gel-like solution or a physical network. A “gel-like solution” can have a low solids content (i.e., from about 5 wt % to about 30 wt %) and a high viscosity (>15,000 cps) at low shear stress (about 6 rpm) when measured by a Brookfield viscometer (Brookfield Ametek, Mass.) at 25° C. In another example, the high viscosity is 20,000 cps at 6 rpm, and in still another example, the high viscosity is 30,000 cps at 6 rpm. A gel-like solution can behave like a non-flowable, semi solid gel, but is able to de-bond at higher shear forces, e.g., 100 rpms or greater, to yield a low viscosity fluid, e.g., less than 500 cps. The gel-like solution is referred to herein as the waterproofing composition.
As such, the waterproofing composition used to form the waterproof coating 26 can have thixotropic behavior. As used herein, “thixotropic behavior” refers to fluids that are non-Newtonian fluids, i.e. which can show a shear stress-dependent change in viscosity. The term “non-Newtonian” refers herein to fluid having a viscosity change that is a non-linear response to a shear rate change. For example, a fluid may exhibit non-linear shear thinning behavior in viscosity with increasing rate of shear. The stronger the thixotropic characteristic of the waterproofing composition when it undergoes shear stress, the lower the viscosity of the waterproofing composition. When the shear stress is removed or reduced, the viscosity can be increased again. Without being limited to any theory, it is believed that such thixotropic behavior reduces the penetration of the waterproofing composition into the fabric base substrate 12 and helps retain the composition at the back-side 20 surface of the coated yarn strands 15. The waterproofing composition becomes thin under shear force when applied by a coating application head (such as under the knife with a floating knife coater). When the waterproofing composition is deposited (the nip of the blade and shear force are removed), the viscosity of fluid can be quickly increased and the waterproof coating 26 can remain on the surface at the back-side 20.
The physical networking agents are high molecular weight polymers, i.e. having a weight average molecular weight ranging from about 300,000 Mw to about 1,000,000 Mw. The physical networking agents can be copolymers of acrylates, copolymers with an acrylate-based polyelectrolyte backbone, copolymers with a polyester backbone, or copolymers with a polyurethane backbone. Another suitable physical networking agent is hydroxyethyl cellulose. In some examples, the physical networking agent is selected from the group consisting of copolymers of acrylates, copolymers with an acrylate-based polyelectrolyte backbone, copolymers with a polyester backbone, and copolymers with a polyurethane backbone.
In some other examples, the physical networking agent is a copolymer of acrylates, such as a copolymer of methacrylic acid and ethyl acrylate ester; a copolymer having with an acrylate based polyelectrolyte backbone and a weight average molecular weight ranging from about 300,000 Mw to about 1,000,000 Mw; a copolymer having a polyester backbone and a weight average molecular weight ranging from about 300,000 Mw to about 1,000,000 Mw; a copolymer having a polyurethane backbone and a weight average molecular weight ranging from about 300,000 Mw to about 1,000,000 Mw; or a combination thereof. In yet some other examples, the physical networking agent can include an acrylate copolymer, a polyethylene glycol copolymer, a polyurethane copolymer, an isophorone diisocyanate copolymer, or a combination thereof and the physical networking agent can have a weight average molecular weight from 300,000 Mw to 1,000,000 Mw.
In some specific examples, the physical networking agent is a high molecular weight copolymer of acrylates (i.e., having a weight average molecular weight ranging from about 300,000 to about 1,000,000) such as a copolymer of methacrylic acid and ethyl acrylate ester. Examples of such compounds include Acusol® 810A, Acusol® L830, Acusol® 835, and Acusol 842 (from Rohm Haas/Dow Co); or Alcogum® L11, Alcogum® L12, Alcogum® L51, Alcogum® L31, and Alcogum® L52 (from Akzo Nobel Co); or Sterocoll® FS (from BASF). In some examples, the physical networking agent is an aqueous anionic dispersion of an ethyl acrylate-carboxylic acid copolymer such as Sterocoll FS (from BASF). In some other specific examples, the physical networking agent is a high molecular weight copolymer with an acrylate-based polyelectrolyte backbone. Such high molecular weight copolymers with an acrylate-based polyelectrolyte backbone can be, for example, acrylate acid copolymers that include, in the backbone and distributed throughout the polymer chain, grafted pendant groups with long-chain hydrophobic groups and acid groups. Examples of such polymers that are commercially available include Texicryl® 13-317, Texicryl® 13-313, Texicryl® 13-308, and Texicryl® 13-312 (all from Scott Bader Group).
In yet some other specific examples, the physical networking agent is a high weight average molecular weight copolymer with a polyester backbone. Such high molecular weight copolymers with a polyester backbone can be, for example, polyethylene glycol copolymers that include, in the backbone and distributed throughout the polymer chain, grafted pendant with long-chain hydrophobic groups and polar groups. Examples of such polymers that are commercially available include Rheovis® PE from BASF.
In still further specific examples, the physical networking agent is a high weight average molecular weight copolymer with a polyurethane backbone. Such high molecular weight copolymers with a polyurethane backbone can be, for example, copolymers of polyethylene glycol and isophorone diisocyanate, which can have long-chain alkanols at the end-caps and also backbone distributed throughout the polymer chain. Examples of such polymers that are commercially available include Acusol® 880 and Acusol® 882 (from Rohm Haas).
Still another example of a suitable physical networking agent is hydroxyethyl cellulose. An example that is commercially available is Tylose® HS30000 (from SE Tylose GmbH & Co. KG).
Examples of the waterproof agent include polyvinylidene chloride (PVC), a polyolefin, poly(ethylene terephthalate), a wax, perfluorooctane sulfonate, perfluorooctanoic acid, a hydrogen siloxane, a long chain hydrocarbon, and a modified fatty resin. Examples of the polyolefin include polyethylene, polypropylene, or combinations thereof. Examples of the long chain hydrocarbons include at least 100 repeating units. Commercially available examples of the long chain hydrocarbon include Baygard® WRC (from Tanatex Chemicals) and Ecorepel® (from Schoeller). Commercially available examples of the modified fatty resins include Phobotex® RHP, Phobotex® RSH, and Phobotex® RHW (from Huntsman International LLC).
Microencapsulated waterproofing chemicals, such as Smartrepel® Hydro (from Archroma) may also be used. In still another example, a fluorinated acrylic copolymer, such as PHOBOL® CP-C from Hunstman International LLC, may be used.
In some specific examples, the waterproof coating 26 includes a physical networking agent selected from the group consisting of an acrylate copolymer, a polyacrylic acid copolymer, a polyether copolymer, a polyurethane copolymer, and combinations thereof, the physical networking agent having a weight average molecular weight from 300,000 Mw to 1,000,000 Mw; and a waterproof agent selected from the group consisting of polyvinylidene chloride, a polyolefin, poly(ethylene terephthalate), a wax, perfluorooctane sulfonate, perfluorooctanoic acid, a hydrogen siloxane, a long chain hydrocarbon, and a modified fatty resin.
Other functional additives may be included in the waterproof coating 26. Functional additives can be added to control a specific property. Some examples include surfactant(s) for wettability, defoamer(s) for processing control, base or acid buffer(s) for pH control.
Depending on the thixotropic behavior of the waterproof composition and the chemical environment of the waterproof composition (e.g., such as the pH), the weight ratio of water:waterproof agent:physical networking agent:additives may be 100:2:0.8:0.2, and in another example, the ratio may be 100:2:0.55:0.2.
Method for Forming the Fabric Printable Medium
The method for forming a fabric printable medium, comprises applying a finishing composition, including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C., to yarn strands of a fabric base substrate, that includes yarn strands and voids among the yarn strands, thereby forming a finishing coating attached to the yarn strands of the fabric base substrate to form coated yarn strands and pore spaces among the coated yarn strands that coincide with at least some voids of the fabric base substrate. In some examples, the finishing composition is applied at dry coat-weight of 6 gsm or less. In some other examples, the method further comprises the application of a waterproofing composition to a back-side of the coated yarn strands, thereby forming a waterproof coating.
An example of the method 100 for forming the fabric printable medium 10 is depicted in FIG. 2. As shown in FIG. 2, the method 100 includes applying a finishing composition, including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C., to yarn strands 14 of a fabric base substrate 12, thereby forming a finishing coating 22, attached to the yarn strands 14 of the fabric base substrate 12 to form coated yarn strands 15 (as shown at reference numeral 102); and pore spaces 24 among the coated yarn strands 15 that coincide with at least some voids 16 of the fabric base substrate 12. Some examples of the method 100 further comprise applying a waterproofing composition to a back-side 20 of the coated yarn strands 15, thereby forming a waterproof coating 26 (as shown at reference numeral 104 in phantom). In some examples, the finishing coating 22 has a dry coat-weight of 6 gsm or less.
The finishing composition used to form the finishing coating 22 is an aqueous dispersion of the polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C. described herein. The polymeric compound or a mixture of the polymeric compounds having a glass transition temperature is less than 15° C. can represent, from about 80% to about 99% of the total solids the finishing composition, and the rest may include processing aids that are miscible without phase separation or without forming a layered composition at room temperature.
In some examples, the finishing coating is an aqueous dispersion that has a solid content of 8 wt % or less by total weight of the finishing coating composition. In some instances, the solids content of the finishing composition is 7 wt % or less, or 5 wt % or less, or 2.5 wt % or less (these wt % are expressed by total weight of the finishing coating composition). It is believed that this solids content contributes to the formation of the pore spaces 24.
To apply the finishing composition, any suitable coating technique may be used that will allow the composition to adhere to the yarn strands 14 without filling at least some of the voids 16. The application of the finishing composition involves using a coating technique to apply the finishing composition and drying the applied finishing composition. In one example, the finishing composition is applied using a padding process. In this example, the fabric base substrate 12 is immersed into the finishing composition and the yarn strands 14 throughout the fabric base substrate 12 are wetted by the finishing composition. Any excess finishing composition may be pushed out by a pair of rolls preset with constant pressure (e.g., ranging from about 10 PSI to about 200 PSI). The composition is then padded by passing the fabric base substrate 12 having the finishing composition thereon through nips. The nip width and the total pick up of the finishing composition are substantially constant over the substrate 12 width and along the whole length of the roll. The finishing composition may then be dried and thermally cured to form the finishing coating 22 and the coated yarn strands 15. In an example, drying takes place in an infrared (IR) oven with a peak temperature of about 170° C. The peak temperature may vary depending upon the polymeric compound or the mixture of polymeric compounds being coated. Drying may take place in different temperature zones to gradually bring the temperature of the coated substrate 12 up and back down. The various temperatures may range from about 80° C. to about 175° C. In another example, the various temperatures may range from about 120° C. to about 170° C.
Other coating techniques for the finishing composition include a floating knife process or a knife on roll mechanism process. The floating knife process can include stretching the fabric base substrate 12 to form an even uniform surface. The floating knife process can further include transporting the fabric under a stationary knife blade. The knife-on-the roll mechanism (used to apply the composition) can be followed by passing the substrate 12 and finishing composition through calendering pressure nips. The calendering can be done either in room temperature or at an elevated temperature and/or pressure. The elevated temperature can range from about 40° C. to about 100° C., and the elevated pressure can range from about 500 PSI to about 3,000 PSI.
With the formulation of the finishing composition and the processing parameters, the continuous film of the finishing composition around each void 16 in the fabric base substrate 12 begins to break during the drying process. The surface tension of the finishing composition helps maintain the substantially open structure of the pore spaces 24 while the finishing composition stays firmly on the yarn strand 14 surface.
In some examples of the method 100, the waterproof coating 26 is applied after the finishing coating 22 is applied. This may minimize any adhesion impact to the finishing coating 22.
The waterproof composition includes the physical networking agent and the waterproofing agent. In the composition, the waterproofing agent may be in the form of an emulsion. As such, in an example, the waterproof composition includes a physical networking agent selected from the group consisting of an acrylate copolymer, a polyacrylic acid copolymer, a polyether copolymer, a polyurethane copolymer, and combinations thereof, the physical networking agent having a weight average molecular weight from 300,000 Mw to 1,000,000 Mw; and a waterproof agent selected from the group consisting of polyvinylidene chloride emulsion, a polyolefin emulsion, a poly(ethylene terephthalate) emulsion, an aqueous wax emulsion, a perfluorooctane sulfonate emulsion, a perfluorooctanoic acid emulsion, a hydrogen siloxane emulsion, a long chain hydrocarbon emulsion, and a modified fatty resin emulsion.
Any of the previously described coating techniques may be used to apply the waterproof composition to form the waterproof coating 26. One example of a suitable coating technique includes padding, where the fabric base substrate 12 is immersed into the waterproof composition and then exposed to padding by going through pressure nips. In another example, the treatment process is achieved by floating knife, where the fabric base substrate 12 is stretched flat to form an even uniform surface and is transported under a stationary doctor blade. In still another example, the treatment process is achieved by rod coating where a rod (such as Mayer rod) is used to control the amount of the treatment compound. Further, in another example, the treatment process is achieved by air knife coating where pressure air is induced to control the amount of the waterproof composition.
As mentioned above, the waterproof composition is gel-like solution that becomes thin under shear force when applied by a coating application head (such as under the knife with a floating knife coater). When the waterproofing composition is deposited (and the nip of the blade and shear force are removed) (at more than 2 gsm), the viscosity of fluid can be quickly increased and the waterproof coating 26 can remain on the surface at the back-side 20 of the coated yarn strands 15. In contrast, when the amount of the waterproofing composition that is applied is lower (2 gsm or less), the waterproof coating 26 is able to coat the yarn strands 15 and maintain some of the open pore spaces 24. The applied waterproof composition may then be exposed to drying to form the waterproof coating 26.
Printing Method
The printing method comprises: obtaining a fabric printable medium including a fabric base substrate including yarn strands and voids among the yarn strands; a finishing coating attached to the yarn strands of the fabric base substrate to form coated yarn strands, the finishing coating including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and pore spaces among the coated yarn strands and coinciding with at least some of the voids of the fabric base substrate; and applying an ink composition onto an image-side of the coated yarn strands to form a printed image.
An example of the printing method 200 is depicted in FIG. 3. As shown in FIG. 3, the method 200 includes obtaining a fabric printable medium 10 including: a fabric base substrate 12 including yarn strands 14 and voids 16 among the yarn strands 14; a finishing coating 22 attached to the yarn strands 14 of the fabric base substrate 12 to form coated yarn strands 15, the finishing coating 22 including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and pore spaces 24 among the coated yarn strands 15 and coinciding with at least some of the voids 16 of the fabric base substrate 12 (as shown at reference numeral 202); and applying an ink composition onto an image-side 18 of the coated yarn strands 15 to form a printed image (as shown at reference numeral 204).
In some examples, the fabric printable medium 10 that is provided further includes the waterproof coating 26 attached to the coated yarn strands 15 on the back-side 20. In some examples, when needed, the printed image can be dried using any drying device attached to a printer such as, for instance, an IR heater.
Any example of the fabric printable medium 10 disclosed herein may be used in the method 200. The ink is printed onto the image-side 18, which has the finishing coating 22 exposed. The finishing coating 22 may be particularly suitable to receive aqueous pigmented inks (e.g., aqueous latex inks) to generate vivid and sharp images. The finishing coating 22 functions as an ink receiving coating since, during the printing process, ink(s) will be directly deposited thereon. The printed image will have, for instance, enhanced image quality and durability.
In some examples of the method 200, printing is accomplished at speeds needed for commercial and other printers such as, for example, HP Latex printers such as 360, 560, 1500, 3200 and 3600 (HP Inc., Palo Alto, Calif., USA). In some examples, the ink composition is an inkjet ink composition that contains one or more colorants that impart the desired color to the printed image and a liquid vehicle.
As used herein, “colorant” includes dyes, pigments, and/or other particulates that may be suspended or dissolved in an ink vehicle. The colorant can be present in the ink composition in an amount required to produce the desired contrast and readability. In some examples, the ink compositions include pigments as colorants. Pigments that can be used include self-dispersed pigments and non-self-dispersed pigments. Any pigment can be used; suitable pigments include black pigments, white pigments, cyan pigments, magenta pigments, yellow pigments, or the like. Pigments can be organic or inorganic particles as well known in the art. As used herein, “liquid vehicle” is defined to include any liquid composition that is used to carry colorants, including pigments, to the fabric printable medium 10 disclosed herein. A wide variety of liquid vehicle components may be used and include, as examples, water or any kind of solvents.
In some other examples, the ink composition, applied to the fabric printable medium 10, is an ink composition containing latex components. Latex components are, for examples, polymeric particulates dispersed in water. The ink composition may contain polymeric latex particulates in an amount representing from about 0.5 wt % to about 15 wt % based on the total weight of the ink composition. The polymeric latex refers herein to a stable dispersion of polymeric micro-particles dispersed in the aqueous vehicle of the ink. The polymeric latex can be natural latex or synthetic latex. Synthetic latexes are usually produced by emulsion polymerization using a variety of initiators, surfactants and monomers. In various examples, the polymeric latex can be cationic, anionic, nonionic, or amphoteric polymeric latex. Monomers that are often used to make synthetic latexes include ethyl acrylate; ethyl methacrylate; benzyl acrylate; benzyl methacrylate; propyl acrylate; methyl methacrylate, propyl methacrylate; iso-propyl acrylate; iso-propyl methacrylate; butyl acrylate; butyl methacrylate; hexyl acrylate; hexyl methacrylate; octadecyl methacrylate; octadecyl acrylate; lauryl methacrylate; lauryl acrylate; hydroxyethyl acrylate; hydroxyethyl methacrylate; hydroxyhexyl acrylate; hydroxyhexyl methacrylate; hydroxyoctadecyl acrylate; hydroxyoctadecyl methacrylate; hydroxylauryl methacrylate; hydroxylauryl acrylate; phenethyl acrylate; phenethyl methacrylate; 6-phenylhexyl acrylate; 6-phenylhexyl methacrylate; phenyllauryl acrylate; phenyllauryl methacrylate; 3-nitrophenyl-6-hexyl methacrylate; 3-nitrophenyl-18-octadecyl acrylate; ethyleneglycol dicyclopentyl ether acrylate; vinyl ethyl ketone; vinyl propyl ketone; vinyl hexyl ketone; vinyl octyl ketone; vinyl butyl ketone; cyclohexyl acrylate; methoxysilane; acryloxy-propyhiethyl-dimethoxysilane; trifluoromethyl styrene; trifluoromethyl acrylate; trifluoromethyl methacrylate; tetrafluoropropyl acrylate; tetrafluoropropyl methacrylate; heptafluorobutyl methacrylate; butyl acrylate; iso-butyl methacrylate; 2-ethylhexyl acrylate; 2-ethylhexyl methacrylate; isooctyl acrylate; and iso-octyl methacrylate.
In some examples, the latexes are prepared by latex emulsion polymerization and have a weight average molecular weight ranging from about 10,000 Mw to about 5,000,000 Mw. The polymeric latex can be selected from the group consisting of acrylic polymers or copolymers, vinyl acetate polymers or copolymers, polyester polymers or copolymers, vinylidene chloride polymers or copolymers, butadiene polymers or copolymers, polystyrene polymers or copolymers, styrene-butadiene polymers or copolymers and acrylonitrile-butadiene polymers or copolymers. The latex components are in the form of a polymeric latex liquid suspension. Such polymeric latex liquid suspension can contain a liquid (such as water and/or other liquids) and polymeric latex particulates having a size ranging from about 20 nm to about 500 nm or ranging from about 100 nm to about 300 nm.
To further illustrate the present disclosure, examples are given herein. It is to be understood that these examples are provided for illustrative purposes and are not to be construed as limiting the scope of the present disclosure.

EXAMPLES

Examples of the fabric printable medium disclosed herein are prepared. Two comparative example fabric media are also prepared. Both example media and comparative media have a fabric base substrate that is a 100% polyester fabric, and the polyester strands has a plain weave. The basis weight is 105 gsm.
Each of the example fabric printable media (MF1, MF1a and MF2) and the comparative example media (MF1b, MF1c, MF3 and MF4) are coated with a finishing composition (F1 to F4) in a dry pick up weight of 1.5 gsm. Table 1 shows the composition of the finishing composition (F1 and F2 are finishing compositions according to the present disclosure; F3 and F4 are comparative examples).
The pick-up of each finishing composition is 1.5 gsm. All formulation F1 to F4 contains water in an amount that adjust to appropriate solids content (Balance of formulation). The pick-up study is performed by adjusting solids content of surface finishing composition to obtain the targeted dry pick up weight as illustrate in Table 3.

TABLE 1

Finishing composition

Surface

Rheology

Polymeric compound

Exam-	tension	control	Chemical	Amount
ples	control agent	gent	name and Tg	(dry parts)

F1	Byk-Dynwet ®	Tylose ® H	Sancure ®	90
	800	100000 YP2	2310
	(from BYK),	(from HsinEtsu	(from Lubrizol)
	0.2 dry parts	co), 0.34 parts	Tg = −23° C.
F2	Byk-Dynwet ®	Tylose ® H	Texicryl ®	90
	800	100000 YP2	13-220
	(from BYK),	(from HsinEtsu	(from Scott
	0.2 dry parts	co), 0.34 parts	Bader)
			Tg = −25° C.
F3	Byk-Dynwet ®	Tylose ® H	Raycat ®	90
(compar-	800	100000 YP2	78 (from
ative)	(from BYK),	(from HsinEtsu	Specialty
	0.2 dry parts	co), 0.34 parts	Polymers)
			Tg = 98° C.
F4	Byk-Dynwet ®	Tylose ® H	Roven ® 4475	90
(compar-	800	100000 YP2	(from Mallard
ative)	(from BYK),	(from HsinEtsu	Creek
	0.2 dry parts	co), 0.34 parts	Polymers)
			Tg = 21° C.

The finishing coating is made by depositing the finishing composition on the fabric base substrate using a lab Methis padder with the speed of 5 meters per minute, and then the applied composition is dried using an IR oven with peak temperature 120° C. Each of the example fabric printable media (MF1 and MF2) and the comparative example media (MF3 and MF4) is coated with a waterproofing composition. Table 2 shows the composition of the waterproof composition.

TABLE 2

Waterproofing Composition

Component		Parts
Type	Specific Component	(by dry weight)

Waterproof	Phobol ®	100
agent	(from Huntsman International LLC)
Physical	Tylose ® HS30000	Adjust to
Networking	(from SE Tylose GmbH & Co. KG)	appropriate
Agent		viscosity
Balance of	Water	Adjust to
formulation		appropriate
		solids content

After padding the finishing composition, the back side waterproof composition is applied by a Methis lab blade coater equipped with an IR dryer. The blade used is a 90-degree flat blade. For both padding operations, the padding pressure is 50 PSI, speed setting is 0.25, and dryer temperature is 100° C., 120° C. and 90° C. for each zone.
Fabric printable medium sample are produced: each comprises a waterproofing composition and a finishing composition (F1 to F4). The media samples MF1, MF2 and MF1a are media samples according to the present disclosure. The media samples MF3, MF4, MF1b and MF1c are comparative samples.
The finishing composition F1 is used for dry pick-up weight study beyond standard dry pick up weight 1.5 gsm. Table 3 summaries results for dry coat-weight of various coatings weight applied to the examples (MF1 and MF1a) and comparative examples (MF1b and MF1c). All four examples have the same surface finishing composition (formulation F1) but different dry pick weight. The coat-weight of the waterproof coating of the examples ranges from 1.5 gsm to 2 gsm for media samples MF1, MF2 and MF1a, and the coat-weight of the waterproof coating on the comparative examples ranged from greater than 2 gsm to 5 gsm (media samples MF1b, MF1c).

TABLE 3

MEDIA	Dry Coat-Weight	Waterproof Coating
SAMPLE	of Finishing Coating	(Dry Coat-Weight)

MF1	1.5 gsm	1.5 to 2 gsm
MF1a	3.3 gsm	1.5 to 2 gsm
MF1b	7.3 gsm	2 to 5 gsm
MF1c	11.6 gsm	2 to 5 gsm

Images are printed on each of the media using latex inks and an HP L-560 printer. The example and comparative example media are tested for porosity, hole openness under microscopy, media gloss, black optical density, 72 color gamut, coin scratch, dry rub, folding resistance, and wind resistance.
Porosity is measured by testing the air flow (mL/min) through the medium per Tappi method T526 (e.g., using a Hagerty Technologies instrument (from Technidyne)) or per Tappi method T-555 (e.g., using a Parker Print-Surf instrument (from Testing Machines, Inc.)). Hole openness is evaluated under microscope, and these results are given a rating of 5=best (open pores) and 1=worst (pores closed). Media gloss is tested using a gloss meter from BYK Gardner, which measures gloss at 60°. Black optical density measures the black color intensity and is measured using an X-rite spectrodensitometer from X-Rite Inc. 72 color gamut tests the portion of the color space that is represented or reproduced, and, in this example, is tested using a Gregtag/Mcbeth Spectrolina Spectroscan or a Barberie. The coin scratch is tested using a round metal piece that is dragged against the ink to demonstrate its resistance to removal (Taber Industries, 5750 linear Abraser, used coin holder). These results are given a rating of 5=best (no ink removal) and 1=worst (ink removed). The dry rub is tested using a cloth wrapped on one end of solid cylinder surface that comes in contact on the ink and is rubbed back and forth 5 times with certain weight ranging from 180 g to 800 g (Taber Industries, 5750 linear Abraser, used coin holder and cloth). These results are given a rating of 5=best (no ink removal) and 1=worst (ink removed). Folding resistance is tested by folding the medium like a bed sheet 4 times, and then placing a 20-pound weight on the folded medium for 30 minutes. These results are given a rating of 5=best (no ink removal) and 1=worst (ink removed/white lines formed). Tables 4 and 5 illustrates the results.

TABLE 4

Media			72
Sample	Media	Black Optical	Color	Coin	Dry	Folding
ID	Gloss	Density (KOD)	Gamut	Scratch	Rub	Resistance

MF1	3.4	1.25	~255K	4	4	3.5
MF2	3.8	1.31	~267K	4.5	4	3.8
MF3	6.5	1.42	~285K	1	3	1
MF4	5.3	1.37	~259K	2.5	3	2

TABLE 5

Media	Porosity By	Coin	Dry	Folding
Sample ID	Hole Openness	Scratch	Rub	Resistance

MF1	5 - open	4	4	3.5
MF1a	4 - reasonably open	3.5	4	3
MF1b	2.5 - partially closed	2.5	3	2
MF1c	1 - closed	1	4	1

It is found that surface finishing with the media with polymeric compound according to the present disclosure have better overall performance.
It is to be understood that the ranges provided herein include the stated range and any value or sub-range within the stated range. For example, from about 40° C. to about 100° C. should be interpreted to include not only the explicitly recited limits of from about 40° C. to about 100° C., but also to include individual values, such as about 55.5° C., about 77.74° C., about 84° C., about 95° C., etc., and sub-ranges, such as from about 46° C. to about 86° C., from about 60.5° C. to about 90.5° C., etc. Furthermore, when “about” is utilized to describe a value, this is meant to encompass minor variations (up to +/−10%) from the stated value.
Reference throughout the specification to “one example”, “another example”, “an example”, and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the example is included in at least one example described herein, and may or may not be present in other examples. In addition, it is to be understood that the described elements for any example may be combined in any suitable manner in the various examples unless the context clearly dictates otherwise. In describing and claiming the examples disclosed herein, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

Claims

1. A fabric printable medium, comprising:

a. a fabric base substrate including yarn strands and voids among the yarn strands;

b. a finishing coating, attached to the yarn strands of the fabric base substrate, to form coated yarn strands, the finishing coating including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and

c. pore spaces, among the coated yarn strands, that are coinciding with at least some of the voids of the fabric base substrate.

2. The fabric printable medium as defined in claim 1 wherein the finishing coating has a dry coat-weight of 6 gsm or less.

3. The fabric printable medium as defined in claim 1 wherein, in the finishing coating, the polymeric compound or mixture of polymeric compounds have a glass transition temperature is less than 5° C.

4. The fabric printable medium as defined in claim 1 wherein, in the finishing coating, the polymeric compound is selected from the group consisting of polyacrylate, polyurethane, vinyl-urethane, acrylic urethane, polyurethane-acrylic, polyether polyurethane, polyester polyurethane, polycaprolactam polyurethane, polyether polyurethane, polyamine, and a combination thereof.

5. The fabric printable medium as defined in claim 1 wherein, in the finishing coating, the polymeric compound includes a polyurethane polymer.

6. The fabric printable medium as defined in claim 1 wherein the finishing coating is coated on surfaces of the yarn strands throughout a depth of the fabric base substrate.

7. The fabric printable medium as defined in claim 1 wherein the finishing coating is an aqueous dispersion having a solid content of 8 wt % or less.

8. The fabric printable medium as defined in claim 1, further comprising a waterproof coating attached to a back-side of the coated yarn strands.

9. The fabric printable medium as defined in claim 8 wherein the waterproof coating has a contact angle greater than 60°.

10. The fabric printable medium as defined in claim 8 wherein the waterproof coating has a surface energy of less than 40 mJ/m².

11. The fabric printable medium as defined in claim 8 wherein the waterproof coating includes:

a. a physical networking agent selected from the group consisting of an acrylate copolymer, a polyacrylic acid copolymer, a polyether copolymer, a polyurethane copolymer, and combinations thereof, the physical networking agent having a weight average molecular weight from 300,000 Mw to 1,000,000 Mw; and

b. a waterproof agent selected from the group consisting of polyvinylidene chloride, a polyolefin, poly(ethylene terephthalate), a wax, perfluorooctane sulfonate, perfluorooctanoic acid, a hydrogen siloxane, a long chain hydrocarbon, and a modified fatty resin.

12. A method for forming a fabric printable medium, comprising applying a finishing composition, including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C., to yarn strands of a fabric base substrate, that includes yarn strands and voids among the yarn strands, thereby forming a finishing coating attached to the yarn strands of the fabric base substrate to form coated yarn strands and pore spaces among the coated yarn strands that coincide with at least some voids of the fabric base substrate.

13. The method as defined in claim 12 wherein the application of the finishing composition is applied at dry coat-weight of 6 gsm or less.

14. The method as defined in claim 12, further comprising applying a waterproofing composition to a back-side of the coated yarn strands, thereby forming a waterproof coating.

15. A printing method, comprising:

a. obtaining a fabric printable medium including a fabric base substrate including yarn strands and voids among the yarn strands; a finishing coating attached to the yarn strands of the fabric base substrate to form coated yarn strands, the finishing coating including a polymeric compound or a mixture of polymeric compounds having a glass transition temperature is less than 15° C.; and pore spaces among the coated yarn strands and coinciding with at least some of the voids of the fabric base substrate; and

b. applying an ink composition onto an image-side of the coated yarn strands to form a printed image.