Patent ID: 12226991

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Instead, the embodiments are chosen and described so that those skilled in the art may appreciate and understand the principles and practices of the present invention.

The present invention provides PVC resin-based fabrics that are useful in a wide range of applications, non-liming examples of which include fabric coverings for seating, cushions, pillows, luggage, bags, backpacks, clothing, headgear, wallcoverings, and window treatments. Many embodiments of the fabrics of the present invention are weather resistant and waterproof and thus are useful as upholstery fabric in marine applications such as marine cushions and the like.

FIG.1depicts a marine vessel10including an upholstery cushion12that is covered at least in part by a fabric14of the present invention.

As seen inFIG.2, upholstery cushion12includes a three dimensional core16. Fabric14, which includes an outer surface30, covers at least a portion of core16. Fabric14may be affixed to the core16using any suitable attachment method(s) including, but not limited to, adhesive or tape, stitching, staples, rivets, snaps, other fasteners, clips, clamps, drawstrings, and combinations of these.

Core16often includes a foam body18that is resiliently compressible by a user. Cushion12optionally can include a rigid backer20to help provide structural support when cushion12is used as a seat or has an additional function as a lid for a storage compartment or the like. Rigid backers may be made from a wide range of natural and/or synthetic materials such as wood, composite panels such as plywood, polymeric panels, metal plates, etc.

Fabric14generally includes substrate22and, provided thereon, a polymeric film24. Substrate22serves as a structural backing and reinforcement for fabric14. Substrate22desirably is flexible and possesses sufficient elasticity for the particular end-use application. Where fabric14might be exposed to water, high humidity, or other moisture, substrate22desirably is hydrophobic, water resistant, and/or waterproof to minimize absorption or other undesirable, water-associated effects.

A wide variety of materials are suitable to form substrate22. Suitable examples include a wide variety of film-based, woven, or non-woven cloths made from any suitable natural or synthetic material. Woven or nonwoven synthetic cloths are particularly useful when fabric14is to be used in marine environments. In one embodiment, a polyester cloth knitted with a circular weave and having a weight of 3 oz./yd.2was found to be suitable. This cloth may be treated using conventional strategies to improve adhesion of polymeric film24to the cloth. Substrate material including filament fibers may be used as an alternative or in combination with spun fibers, but filament fibers have a tendency to provide stiffer fabric embodiments.

The cloth may be treated to help promote adhesion of polymeric film24to the cloth. A wide variety of such treatments may be used singly or in combination such etching, exposing to ultraviolet light, exposure to an electron beam, priming with a suitable primer or adhesive, chemically modifying the surface, combinations of these, or the like.

Pink staining tends to originate proximal to substrate22because this is whereStreptoverticillium reticulumbacteria typically live and generate chromophore(s) that cause the discoloration. The present invention advantageously provides an extremely effective way to prevent this discoloration from reaching outer surface30of fabric14. The protection is long-lasting, not consumed by its protective function (as would be true with many biocides), and is integral with fabric14. The result is that the protection remains in place as fabric14is used.

Polymeric film24can be formed from a single, layer or may be a laminate of two or more layers that are individually formed. Alternatively, polymeric layer can be formed from multiple layers formed in situ. As shown inFIG.3, polymeric film24has a multi-layer structure in which multiple layers are formed in situ during manufacture, described further below.

Polymeric film24includes a foamed lower layer26and an outer skin layer28. Setting aside the foamed structure of lower layer26, the composition of lower layer26and outer skin layer28may be the same or different.

Foamed lower layer26has a lower surface25adhered to substrate22and an upper surface27integrally formed to outer skin layer28.

Outer skin layer28has lower surface29integrally formed to lower layer26and outer surface30generally visible to the user. (Outer surface30also is the surface30of fabric14that a user feels or touches.) As an option, outer surface30may include features to provide a desired texture or pattern. Embossing often is a suitable technique to form such a texture or pattern.

Polymeric film24includes at least one chlorinated resin deployed in layers26and/or28, preferably both layers26and28. Chlorinated resins help to provide fabric14with excellent hand, visual appearance, and durability, particularly in marine environments in which fabric14is exposed to solvents, fresh water, salt water, and the like.

Useful resins include at least 10, preferably at least 20, or more preferably at least 50 mer units and up to 100, 500, 1000, or 5000 mer units. The weight average molecular weight (Mw) can range from 500 to 200,000, preferably 1000 to 150,000, more preferably 2000 to 100,000 g/mol.

A chlorinated resin refers to a resin derived from one or more reactants, at least one of which is at least includes at least one Cl atom. Optionally, such reactants may be perchlorinated (i.e., all H atoms replaced by Cl atoms). The Cl substituents of the chlorinated reactant(s) may be attached directly to the reactant backbone by a single bond or via a suitable linking group. In some embodiments, chlorinated reactants may be monomeric, oligomeric, and/or polymeric.

The Cl content of the chlorinated resin can vary over a wide range. In many embodiments, it is desirable that a chlorinated resin includes at least ˜20%, preferably at least ˜40%, and more preferably at least ˜60% Cl (all w/w). Perchlorinated embodiments represent a practical upper limit upon Cl content.

Desirably, such chlorinated reactants are free radically polymerizable. Free radical polymerization can occur via a variety of techniques including suspension polymerization, bulk polymerization, emulsion polymerization or solution polymerization.

Examples of free radically polymerizable functionalities include olefinic C—C double bonds, (meth)acrylic groups, allyloxy groups, vinyl groups (e.g., styrenic compounds), cyanate ester groups, vinyl acetate, vinyl ether groups, combinations of these, and the like. Free radically polymerizable functionality is conveniently reacted by exposing the reactants to a suitable source of curing energy, often in the presence of agents (e.g., initiators, etc.) that help promote the desired reaction. The energy source used for achieving polymerization and/or crosslinking of the curable functionality may be actinic (e.g., radiation having a wavelength in the UV or visible region of the spectrum), accelerated particles (e.g., e-beam radiation), thermal (e.g., heat or infrared radiation), or the like.

Illustrative embodiments of free radically polymerizable, chlorinated reactants useful for making chlorinated resins may have structures including 2 to 20, preferably 2 to 10, more preferably 2 to 4 C atoms and at least one C—C double bond. More preferred are partially or fully chlorinated ethenes, chlorinated propenes, and combinations of these, such as monochloroethene (vinyl chloride monomer), 1,2-dichloroethene, 1,1,2-trichloroethene, tetrachloroethene, 1-chloropropene, 2-chloropropene, 1,1-dichloropropene, 2,2-dichloropropene, 1,2-dichloropropene, 1,1,1-trichloro-2-propene, 1,1,2-1-propene, 1,2,3-trichloropropene, combinations of these, and the like.

A preferred class of chlorinated resin is polyvinyl chloride, also referred to herein as PVC polymers or resins. A PVC resin refers to a homo- or interpolymer that includes mer resulting from incorporation of vinyl chloride monomer, CH2═CHCl. PVC resins which include at least 50%, preferably at least 90%, more preferably at least 99%, and most preferably substantially 100% (all w/w) vinyl chloride mer are preferred. A PVC resin formed from only vinyl chloride monomer (except for terminal end groups) is thermoplastic, linear, and very strong.

The PVC resin(s) may be thermoplastic or thermosetting. Thermoplastic PVC resins are preferred for use in the illustrative manufacturing method described below.

Different PVC resins and methods of making PVC resins are widely described in the patent and technical literature; see, e.g., U.S. Pat. Nos. 4,418,169 and 5,290,890; U.S. Pat. Publ. Nos. 2012/0095176 and 2012/0177856. PVC resins are commercially available from a variety of commercial sources. Examples include SG710 resin suspension (Thai Plastic and Chemicals Public Co., Ltd.; Thailand); Formosa F676 and F2110 resins (Formosa Plastics Corp.; Livingston, New Jersey); Oxy Chem Oxyvinyl 500F (OxyVinyls, LP; Dallas, Texas); and Shintech SE1300F (Shintech, Inc.; Houston, Texas).

Polymeric film24also includes at least one polymeric plasticizer that is used in an amount effective to improve the flexibility of the polymeric film24and corresponding fabric14. A polymeric plasticizer also may help to provide a softer feel to fabric14.

As used herein, a plasticizer refers to a compound that increases the flexibility of chlorinated resins, particularly PVC, and a polymeric plasticizer refers to a polymer capable of acting as a plasticizer.

In many embodiments, a suitable polymeric plasticizer meets two criteria: (1) full miscibility with the chlorinated resin(s) (with fully miscibility considered to be the presence of a single phase at 25° C. in a 20 phr composition) and (2) a glass transition temperature (Tg) that is lower than the Tgof any of the chlorinated resin(s) in the composition (with Tgbeing determinable via DSC). Generally, the plasticizer Tgdesirably is at least 10°, preferably at least 20°, and more preferably at least 30° C. lower than that of the resin(s) in the composition.

The polymeric plasticizer can have Mw≥1000, preferably ≥2000, or more preferably ≥3000. The molecular weight can be limited to make it easier to blend or otherwise use the plasticizer to make fabric14; for example, polymeric plasticizer can have Mw≤150,000, preferably ≤100,000, or more preferably ≤75,000. (Molecular weight ranges can be provided by combining any of the lower limits with any of the upper limits.)

One class of polymers suitable for use as plasticizers for PVC includes adipic acid polyester polymers. A wide variety of polymeric plasticizers available from many commercial sources, non-limiting examples of which include ELVALOY HP plasticizers (Dow DuPont; Wilmington, Delaware); ADMEX plasticizers Eastman Chemical Company (Kingsport, Tennessee); PALAMOLL plasticizers BASF (Leverkusen, Germany); and the PN series of plasticizers (Adeka; Tokyo, Japan).

The amount of polymeric plasticizer(s) present in polymeric film24is effective to help plasticize the PVC resin(s). A wide range of amounts would be suitable depending on the degree of flexibility and softness desired. As illustrative guidelines, the weight ratio (on a solids basis, exclusive of solvent) of chlorinated resin(s) to polymeric plasticizer(s) can range from 1:10 to 10:1, preferably from 1:5 to 5:1, more preferably from 1:2 to 2:1, even more preferably from 3:4 to 4:3, and most 1:1±10%.

Significantly, use of a polymeric plasticizer is one of the features of the present invention that works in combination with other components described herein to help prevent surface discoloration of the fabric14associated withStreptoverticillium reticulum.

The polymeric plasticizer may help prevent discoloration by one or more possible mechanisms. First, a polymeric plasticizer may be more fixed and less mobile in the resultant film as compared to small molecule plasticizers such as a phthalate; in combination with a high loading of TiO2and an antioxidant, this immobility appears to help establish a barrier that blocks internal discoloration from reaching outer surface30of fabric14.

Second, and related to the first, the reduced mobility of a polymeric plasticizer might reduce the rate of transport of chromophores produced byStreptoverticillium reticulumbacteria from the interior of the upholstery, where the bacteria thrive, to outer surface30; this is in contrast to the significant mobility of small molecule plasticizers.

Third, the high loading of TiO2and antioxidant(s) are believed to contribute to the relative immobility of the polymeric plasticizer.

Thus, it is believed that all three components—polymeric plasticizer, the high loading of TiO2, and antioxidant—cooperate to help establish a more effective discoloration barrier and/or to more effectively deny the discoloration a transport mechanism to reach outer surface30. In certain embodiments, the three ingredients alone (or with minor amounts of other ingredients) constitute a discoloration inhibiting additive package.

The presence of small molecule plasticizers such as phthalates or terephthalates can worsen discoloration problems associated withStreptoverticillium reticulumin upholstery fabric14. However, the combination of the polymeric plasticizer, high loading of TiO2, and antioxidant(s) can help alleviate discoloration even if certain small molecule plasticizers, particularly phthalates or terephthalates, are present, although the best protection against discoloration is achieved if small molecule plasticizers (having a molecular weight under about 750 g/mol, or even under about 500 g/mol) are omitted. Accordingly, polymeric film24of the present invention desirably is substantially free of phthalate and/or terephthalates small molecules and/or other plasticizer small molecules

Polymeric plasticizer may be uniformly distributed throughout polymeric film24such that the composition of polymeric film24with respect to the plasticizer is uniform throughout both foamed lower layer26and outer skin layer28.

Alternatively, the polymeric plasticizer may be deployed selectively only in portions of polymeric film24. For example, in one embodiment, the polymeric plasticizer is selectively incorporated into foamed lower layer26. In this way, the plasticizer is able to function as a barrier and to block discoloration transport in the region of polymeric film24most proximal to theStreptoverticillium reticulumcausing the discoloration. This selective incorporation avoids using the plasticizer in the outer skin layer28, which is advantageous because a polymeric plasticizer is a relatively expensive ingredient. If polymeric plasticizer is selectively incorporated into only one or more portions of polymeric film24, the weight ratio of the plasticizer used is still based on the total amount of PVC resin(s) used throughout polymeric film24.

The polymeric film24further includes TiO2. When used at relatively high loadings and in combination with the polymeric plasticizer(s) and the antioxidant, TiO2helps to prevent surface discoloration on fabric14. The TiO2is believed to help both establish a barrier to block discoloration as well as interrupt transport mechanisms that would otherwise shuttle discoloring chromophores from their bacterial source to the surface.

Any form of titania, including monoclinic, rutile, anatase, and brookite, can be used. A rutile embodiment presently is preferred.

The TiO2particles may have diameters within a wide range. As general guidelines, the TiO2particles can have an average diameters in the range from 0.05 to 1.0 μm, preferably 0.1 to 0.5 μm, more preferably 0.1 to 0.3 μm. In one experiment, an average particle size of 0.2 μm was found to be suitable. (Average particle size may be determined according to ISO 13317-3:2001.)

Polymeric film24incorporates TiO2at a weight loading that is higher than is typical in most vinyl upholstery fabrics. As general guidelines, polymeric film24includes from ˜7 to ˜30, preferably from ˜10 to ˜30, phr TiO2.

Polymeric film24also includes one or more antioxidants, which are molecules that inhibit the oxidation of other molecules. Use of an antioxidant with chlorinated resins in upholstery fabric applications because because resins generally are considered to be highly resistant to oxidation. However, antioxidants appear to provide additional functionality in polymeric film24. When used in combination with the polymeric plasticizer(s) and TiO2, the antioxidant(s) help to prevent surface discoloration of fabric14.

A wide variety of antioxidant(s) may be used in polymeric film24. A preferred class of antioxidants is the sterically hindered, hydroxyl functional, aromatic antioxidants. Such antioxidants include at least one hydroxyl group pendant directly or indirectly from an aromatic moiety, wherein at least one, preferably two, substituents are ortho to the pendant hydroxyl group. A phenyl moiety comprising at least one linear or branched C1-C10alkyl group ortho to the OH group of the phenol are preferred. More preferred alkyl moieties include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, and the like.

Preferred antioxidants are those having molecular weights of from 500 to 5000 g/mol. Such higher molecular weight antioxidants preferably are branched compounds that include a plurality (e.g., 2-10, often 2-6) of sterically hindered phenol moieties independently attached to a common carbon atom by a single bond or a divalent linking group having up to 5, 10 or even 20 C atoms. In some embodiments, the linking groups may be part of a common ring structure with each other and/or the common carbon atom. Additionally or alternatively, the divalent linking group can include one or more ester linkages.

An illustrative example of a branched compound that includes multiple sterically hindered phenol moieties has the following formula (with “tBu” representing a t-butyl group):

The amount of antioxidant(s) used in polymeric film24may be selected within a wide range, for example, from 0.1 to 10, preferably 0.5 to 5, phr antioxidant. If too little is used, the ability of the antioxidant to help protect against discoloration may be less than desired. Using too much may be wasteful in the sense of providing little extra protection while potentially risking a reduction in desired performance characteristics.

As an option, polymeric film24may include one or more additional ingredients to facilitate manufacture of fabric14, to help adjust properties of fabric14, or the like. By way of example, optional ingredients may include one or more of UV stabilizers, coloring aids, lubricants (such as to help prevent sticking of the fabric components to equipment during manufacture and/or to prevent blocking of finished fabric14), biocides, antistatic agents, inorganic fillers (other than titania), blowing agents (which can be incorporated into a portion of a polymer film precursor during manufacture such as foamed lower layer26), antifoaming agents (which can be included in other portions such as outer skin layer28), authentication taggants, other polymers, and the like.

Fabric14can be provided in a variety of ways.

A composition that is a precursor of the foamed lower layer26(first precursor composition) is applied onto substrate22. The first precursor composition generally includes a chlorinated resin (e.g., PVC), a polymer plasticizer, TiO2, and an antioxidant as described above. The first precursor composition also may include a blowing agent to help provide the foam structure of lower layer26, one or more suitable solvents, and/or processing aids to help reduce the tendency of the applied precursor coating to stick to fabrication equipment such as steel rolls on calendaring equipment. An exemplary first precursor composition is provided in Table 1, immediately below.

TABLE 1Exemplary first precursor compositionAmountIngredient(pbw)SG710 PVC resin suspension100.00*ADK CIZER PN-310 adipic acid polyester polymeric plasticizer92.00*UV and thermal stabilizers2.24CaCO3filler20.00blowing agent3.94foam cell adjuster for fine foam2.5powder lubricants5.42TiO2, rutile9.00antioxidant containing four sterically hindered phenol moieties2.00Biocide5.00*Includes solvent as supplied by commercial source.

The first precursor composition is cured. Only partial foaming, if any, is allowed to occur at this stage by curing the first precursor layer at a sufficiently low temperature to avoid unduly activating the blowing agent.

Thereafter, a second precursor composition, from which outer skin layer28will be formed, is applied on lower layer26. The second precursor composition generally is similar to the first except that the second need not include blowing agents or associated additives if outer skin layer28is not desired to be in the form of a foam. The second precursor composition optionally may include one or more colorants to adjust the color of outer skin layer28which, unlike lower layer26, is visible to the end user. For example, the TiO2tends to provide a very stark white color to fabric14, although small amounts of colorants to soften the white (to ivory, eggshell, beige or other more muted colors) or to provide other hues may be used. An exemplary second precursor composition is provided in Table 2, immediately below.

TABLE 2Exemplary second precursor compositionAmountIngredient(pbw)SG710 PVC resin suspension100.00*ADK CIZER PN-310 adipic acid polyester polymeric plasticizer96.00*UV and thermal stabilizers2.50CaCO3filler25.00powder lubricants4.25TiO2, rutile25.00antioxidant containing four sterically hindered phenol moieties2.00colorants0.14biocide5.30*Includes solvent as supplied by commercial source.

The second precursor composition then is cured before the entire structure is heated in a foaming oven to activate the blowing agent in the first precursor layer, which causes the first precursor composition to foam and expand, providing an expanded layer (e.g., 55 to 60 mils thickness). If desired, the product can be compressed to a desired final thickness such as, e.g., 40 mils.

The compression may occur with embossing to help provide a desired texture or pattern on the surface.

PVC films have a tendency to be naturally tacky and may have low surface tension. Accordingly, a suitable top finish may be applied onto outer skin layer28to provide a desired finish, to seal the surface, and to reduce tackiness. A suitable top finish may be applied at any desired coating weight such as from 7 to 8 g/m2. For a review of coating and lamination techniques used with fabrics, the interested reader is directed to K. Singha, “A Review on Coating & Lamination in Textiles: Processes and Applications,”Am. J. Poly. Sci.,2012, 2(3): 39-49.

While various embodiments of the present invention have been provided, they are presented by way of example and not limitation. To the extent feasible, as long as they are not interfering or incompatible, features and embodiments described above in isolation can be combined with other features and embodiments.

The relevant portions of any document specifically referenced in the preceding text or in the examples that follow are incorporated herein by reference.

The following non-limiting, illustrative examples provide the reader with detailed conditions and materials that can be useful in the practice of the present invention.

EXAMPLES

Example 1: Permanent Marker Test

A study was conducted to evaluate the ability different plasticizers to help PVC-based fabric resist discoloration due to chromophores provdued byStreptoverticillium reticulum.

A control sample was prepared from a formulation including 100 pbw PVC resin, 88 pbw diisononyl phthalate (DINP) as a monomeric plasticizer, and 27.5 pbw TiO2.

A first embodiment of a PVC resin composition of the present invention was prepared similarly except that 94 pbw adipic acid polyester was used as plasticizer in place of DINP, the amount of TiO2was increased to 34 pbw, and 1.6 pbw antioxidant with four sterically hindered phenol moieties was included.

A second inventive composition was prepared in an identical manner except that a different type of TiO2was used.

Using black, blue, and red permanent markers, color stripes were applied to the front side of each of the samples.

The marked samples were held for 2 hours in an oven set at 180° F.

Upon removal, the samples were examined for color transfer to the back side. The control sample showed a high degree of color transfer through the sample; all three colors were easily visible from the back side. No color transfer was visible with respect to the other two samples.

Example 2: Bacterial Chromophore Testing

ASTM 1428-15a describes a test titled “Standard Test Method for Evaluating the Performance of Antimicrobials in or on Polymeric Solids Against Staining byStreptomycesspecies (A Pink Stain Organism),” designed to determine the effectiveness of antimicrobials in vinyl fabrics.

Using the same formulations provided above in Example 1, additional samples were prepared to evaluate resistance to discoloration resulting fromStreptoverticillium reticulum-origin chromophores.

While commercial embodiments of the finished product are expected to include one or antimicrobial(s) so as to inhibit microbial growth, samples without any antimicrobials were prepared to determine the ability to prevent staining. (Pink staining often occurs even when antimicrobials are present, which further reflects the need for a solution to the staining issue.)

The bacterium was inoculated onto an agar surface with a nutrient rich growth medium using the parallel streak method.

Each sample was marked on one side with an ink pen identifier, with that same area then being coated with a portion of the bacterial challenge material. Each sample was exposed to the organism for 14 days, after which each sample was evaluated for color transfer of the discoloring chromophore(s). Discoloration was observed on all the samples on the side coated with challenge material, which confirms production of the discoloring chromophore(s).

Resistance to color transfer from the agar side to the other side was quite different for the samples, however.

Both the ink pen and the chromophore-induced discoloration transferred through the control sample and were readily observable on the opposite side.

For the two inventive samples, however, no color transfer of the discoloration or the ink pen was seen.