Glass substrate interleaving material and coating therefor

Abstract

A slip sheet material comprising a paper substrate. A polymer coating material for coating the paper substrate is also disclosed. The paper substrate may comprise a polymer coating material configured as a coating for the paper substrate. A slip sheet material comprising a paper substrate and a stack of glass substrates separated by the slip sheet material are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63 / 423,938, filed November 9, 2022, the contents of which are relied upon and incorporated herein by reference in their entirety. [Technical Field]

[0002] The present disclosure relates to slip-sheet materials for separating glass substrates, and more particularly to slip-sheet materials comprising a paper substrate. Also disclosed are coatings for coating the paper substrate and stacks of glass substrates separated by slip-sheet materials formed therefrom. [Background technology]

[0003] In the packaging and shipping of glass substrates, such as those used in display applications, interleaf materials, such as slip sheets, are typically interposed between the glass substrates to help protect the glass substrates from damage. In addition to providing physical protection, the interleaf materials can also be designed to minimize the migration of contaminants to the glass surface. Summary of the Invention

[0004] In a first aspect, a polymeric coating material for a paper substrate is disclosed, comprising polyvinyl alcohol and, for each part by weight of polyvinyl alcohol, about 0.016 parts by weight to about 0.03 parts by weight of an antifoaming agent and about 0.05 parts by weight to about 0.625 parts by weight of a lubricant.

[0005] In a second embodiment, the coating material of the first embodiment may further comprise 0.067 parts by weight of an antistatic agent for every 1 part by weight of polyvinyl alcohol.

[0006] In a third embodiment, the coating material of the first embodiment or the second embodiment can further comprise about 0.059 parts by weight to about 0.077 parts by weight of a hydrogen bond breaker for each part by weight of polyvinyl alcohol.

[0007] In a fourth aspect, a slip sheet material for separating glass substrates is described, the slip sheet material comprising a paper substrate having at least one of lignin or cellulose, a first major surface, and a second major surface opposite the first major surface. The slip sheet material further comprises a polymer coating disposed on at least one of the first major surface or the second major surface of the paper substrate, the polymer coating comprising polyvinyl alcohol and, per part by weight of polyvinyl alcohol, about 0.016 parts by weight to about 0.03 parts by weight of an antifoaming agent and about 0.05 parts by weight to about 0.625 parts by weight of a lubricant.

[0008] In a fifth embodiment, the coating of the fourth embodiment may include about 0.067 parts by weight of an antistatic agent for every 1 part by weight of polyvinyl alcohol.

[0009] In a sixth aspect, the antistatic agent of the fifth aspect can include poly4-styrene sulfonate or an amine ethoxylate.

[0010] In a seventh aspect, the coating of any one of the fourth through sixth aspects can include about 0.059 parts by weight to about 0.077 parts by weight of a hydrogen bond breaker for each part by weight of polyvinyl alcohol.

[0011] In an eighth aspect, the thickness of the coating on at least one of the first major surface or the second major surface according to any one of the fourth to seventh aspects can be in the range of about 2 micrometers to about 10 micrometers.

[0012] In a ninth aspect, the coating according to any one of the fourth to seventh aspects may be a continuous coating on at least one of the first major surface or the second major surface.

[0013] In a tenth embodiment, both the first major surface and the second major surface of the ninth embodiment are coated with a coating.

[0014] In an eleventh aspect, the slip-sheet material according to any one of the fourth to tenth aspects may be in a roll form.

[0015] In a twelfth embodiment, the thickness of the slip-sheet material according to any one of the fourth to eleventh embodiments can be about 200 micrometers or less.

[0016] In a thirteenth aspect, the MD tensile strength of the paper substrate according to any one of the fourth to twelfth aspects can be greater than or equal to about 2.86 kilograms per centimeter of width of the paper substrate when measured according to TAPPI T-494.

[0017] In a fourteenth aspect, the CD tensile strength of the paper substrate according to any one of the fourth to thirteenth aspects can be greater than or equal to about 0.7 kg / cm of the width of the paper substrate when measured according to TAPPI T-494.

[0018] In a fifteenth aspect, the tear strength of the paper substrate according to any one of the fourth to fourteenth aspects may be 18 grams or more for 8 layers when measured according to TAPPI T-414.

[0019] In a sixteenth aspect, the paper substrate according to any one of the fourth to fifteenth aspects has a basis weight, expressed in grams per square meter, of about 40 g / m 2 ~Approx. 120g / m 2 It can be in the range of

[0020] In a seventeenth aspect, a stack of glass substrates is disclosed comprising a plurality of glass substrates arranged in a stack, wherein adjacent glass substrates among the plurality of glass substrates are separated by an interleaf material according to any one of the fourth to sixteenth aspects.

[0021] Both the foregoing general description and the following detailed description represent embodiments intended to provide an overview or framework for understanding the nature and features of the embodiments disclosed herein. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the present disclosure and, together with the description, serve to explain the principles and operation thereof. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a cross-sectional end view of an exemplary slip-sheet material. [Figure 2] 1 is a bar graph showing normalized intensity resulting from TOF SIMS measurements of paper substrate samples after exposure to corona discharge at various powers, with and without aging. [Figure 3] FIG. 10 is a bar graph showing normalized intensities resulting from TOF SIMS measurements of a PDMS-contaminated paper substrate sample (total PDMS ions) after exposure to ozone generated from corona discharge, exposure to laser radiation, and UV exposure. [Figure 4] 5 is a bar graph showing normalized intensities resulting from TOF SIMS measurements of the PDMS-contaminated paper substrate sample (total PDMS ions) from Figure 4 after exposure to corona discharge, exposure to laser radiation, and ozone generated from ultraviolet light, indicating the level of silica in the sample. [Figure 5] FIG. 10 is a bar graph showing the normalized intensity resulting from TOF SIMS measurements of PDMS-contaminated paper substrate samples (total PDMS ions) as a function of the molecular weight of the PVA-based coating material. [Figure 6] 1 is a plot showing the FTIR spectral response as a function of wavenumber for two PDMS inhibitor materials and PDMS. [Figure 7] 1 is a plot showing the FTIR spectral response as a function of wavenumber for two PDMS inhibitor materials and PDMS. [Figure 8]1 is a bar graph showing normalized intensities resulting from TOF SIMS measurements of PDMS-contaminated paper substrate samples on control siloxane (CS9K) and Eagle XG glass slides treated with PDMS inhibitor polymer, with and without cleaning (rinsing). [Figure 9] 1 is a plot showing surface tension as a function of PDMS inhibitor concentration in weight percent when added to a PVA coating material. [Figure 10] 1 is a bar graph showing the defoaming ability of PDMS inhibitor polymers as indicated by the volume increase of PVA coating solutions containing PDMS inhibitor. [Figure 11] 1 is a plot showing that the addition of PDMS inhibitor does not affect the viscosity of PVA-based coatings, even at 1 wt % inhibitor polymer loading in PVA-based coatings. [Figure 12] FIG. 10 is a line scan of water contact angles on a 4-inch Si wafer contaminated with PDMS, showing negligible change in water contact angle after aging of the PDMS inhibitor containing PVA-based coating. [Figure 13] FIG. 10 is a line scan of water contact angles on a 4-inch Si wafer contaminated with PDMS, showing negligible change in water contact angle after aging of the PDMS inhibitor containing PVA-based coating. [Figure 14] FIG. 10 is a line scan of water contact angles on a 4-inch Si wafer contaminated with PDMS, showing negligible change in water contact angle after aging of the PDMS inhibitor containing PVA-based coating. [Figure 15] FIG. 10 is a line scan of water contact angles on a 4-inch Si wafer contaminated with PDMS, showing negligible change in water contact angle after aging of the PDMS inhibitor containing PVA-based coating. [Figure 16] 1 is a bar graph showing particle counts per square centimeter of stack for glass substrates interleaved with plain paper interleaf material before and after vibration testing and subsequent cleaning. [Figure 17]1 is a bar graph showing particle counts per square centimeter of stack of glass substrates interleaved with PDMS inhibitor PVA-based coated paper substrates before and after vibration testing and subsequent cleaning. [Figure 18] FIG. 1 is a cross-sectional side view of a stack of glass substrates with interlayer material disposed between adjacent glass substrates. [Figure 19] 1 is a plot of water contact angles measured on various slip-sheet materials. [Figure 20] 1 is a plot of normalized PDMS concentration on a glass surface after contact with various interleaf materials. [Figure 21] 1 is a plot of particle density after vibration testing and subsequent washing for several slip-sheet materials. [Figure 22] 1 is a plot of particle density for several slip-sheet materials after vibration and washing tests, i.e., before test, after vibration, and after washing. [Figure 23] 1 is a plot of particle density for several slip-sheet materials after vibration and washing tests, i.e., before test, after vibration, and after washing. [Figure 24] 1 is a plot of particle density for several slip-sheet materials after vibration and washing tests, i.e., before test, after vibration, and after washing. DETAILED DESCRIPTION OF THE INVENTION

[0023] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0024] As used herein, the term "about" means that amounts, sizes, formulations, parameters, and other quantities and properties are not, and need not be, exact and may be approximate and / or larger or smaller, as desired, to reflect tolerances, conversion factors, rounding, and measurement error, as well as other factors known to those of ordinary skill in the art.

[0025] Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each range are significant both in relation to the other endpoint, and independently of the other endpoint.

[0026] Directional terms used herein, e.g., up, down, right, left, front, back, top, bottom, are made with reference to the drawings and are not intended to imply absolute orientations.

[0027] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring its steps to be performed in a particular order, or that any apparatus requires a particular orientation. Thus, if a method claim does not recite the order that its steps must be followed, or if any apparatus claim does not actually recite an order or orientation for individual components, or if the claim or specification otherwise specifically states that the steps are to be limited to a particular order, or if no particular order or orientation for the apparatus components is recited, then no order or orientation is intended to be inferred in any sense. This applies to all possible implicit bases for interpretation, including logical considerations regarding the arrangement of steps, operational flow, component order, or component orientation, the plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described herein.

[0028] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to an "a" component includes aspects having two or more such components unless the context clearly dictates otherwise.

[0029] The words "exemplary," "example," or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" or "example" is not to be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided only for purposes of clarity and understanding and are not intended to limit in any way the scope or relevant portions of this disclosure. It will be understood that countless additional or alternative examples of various scopes may be presented but have been omitted for purposes of brevity.

[0030] As used herein, the terms "comprises" and "includes," and variations thereof, unless otherwise indicated, should be construed as synonymous and open-ended. A list of elements following a transitional phrase is a non-exclusive list, such that elements may be present in addition to the elements specifically listed in the list.

[0031] As used herein, the terms "substantial," "substantially," and variations thereof are intended to note that a described characteristic is equal to or approximately equal to a value or description. For example, a "substantially planar" surface is intended to describe a surface that is planar or approximately planar. Furthermore, "substantially" is intended to describe two values ​​that are equal or approximately equal. In some embodiments, "substantially" can describe values ​​that are within about 10% of each other, such as within about 5% of each other or within about 2% of each other.

[0032] As used herein, the term "interleaf material," or variations thereof, refers to a material interposed between adjacent glass substrates to provide a protective cushion between them and protect the surfaces of the glass substrates from damage and / or contamination. The interleaf material may include a substrate material, such as a paper material, or a polymeric material, or a combination thereof.

[0033] The migration of contaminants, such as particles and / or chemical species, originating from the interleaf material can be reduced but is difficult to completely prevent. Nevertheless, the interleaf material should be capable of reducing the adhesion of particles migrated to the glass substrate, such as particles originating from the interleaf material, and should enable these particles to be easily cleaned from the glass substrate surface. Work to reduce contamination on stacked (e.g., packaged) glass substrates has involved adding talc, Group II elements, or aluminum to paper substrates to produce interleaf materials for interposing between glass substrates.

[0034] As used herein, the term paper or paper substrate refers to an organic fiber-based material containing cellulose and / or lignin. Such paper substrates are generally sourced from wood fibers (e.g., pulp) and processed to contain varying amounts of cellulose and / or lignin. Referring to FIG. 1 , which illustrates a slipsheet material including a paper substrate 12, the paper substrate 12 can have a thickness T defined between a first major surface 14 and a second major surface 16, where the thickness T is less than about 180 micrometers, e.g., less than about 170 micrometers, e.g., less than about 160 micrometers. Suitable papers can include newsprint, high-cellulose paper, high-lignin paper, and intermediate lignocellulosic paper. The paper substrate may have a machine direction (MD) tensile strength of about 16 lb / inch (2.86 kilograms / centimeter) width or greater and a cross direction (CD) tensile strength of about 3.90 lb / inch (0.7 kg / cm) width or greater, as measured in accordance with TAPPI T-494 (Technical Association of the Pulp & Paper Industry Inc.). The paper substrate may have a tear strength of 18 grams or greater for an 8-ply paper substrate, as measured in accordance with TAPPI T-414. The paper substrate may have a tear strength of about 40 g / m 2 ~Approx. 120g / m 2 In the range of, for example, about 40 g / m 2 ~About g / m 2 110 range, approximately 40g / m 2 ~about 100g / m 2 range, approximately 40 g / m 2 ~about 90g / m 2 range, approximately 40 g / m 2 ~about 80g / m 2 range, approximately 40 g / m 2 ~about 70g / m 2 range, approximately 40 g / m 2 ~about 60g / m 2 or about 40 g / m 2 ~about 50g / m 2 The film may have a basis weight in the range of 1000 to 15000.

[0035] In some embodiments, the paper substrate may have one or both major surfaces 14, 16 treated. For example, at least one of the first major surface 14 or the second major surface 16 may be exposed to a corona discharge, during which contaminants such as polydimethylsiloxane (PDMS) contained on and / or within the paper substrate may be converted to a harmless form, such as silica. PDMS is a common ubiquitous contaminant often found in processed paper resulting from the paper manufacturing process. PDMS residue migrated from the paper substrate to the glass substrate surface may interfere with subsequent processing of the glass substrate, for example, when used as an interlayer material. For example, the presence of PDMS residue may interfere with the deposition of nanoelectronic or macroelectronic structures on the surface of a glass substrate that may be deposited on the glass substrate in the manufacture of electronic display devices. As little as 2.5 ppm of 9,000 grams / mole molecular weight PDMS may result in black matrix film delamination in a color filter manufacturing process in which black matrix material is applied to a glass substrate. In some instances, PDMS contamination of commercially available paper can be as high as that obtained by intentionally contaminating a paper substrate with levels of 250 ppm to 2,500 ppm PDMS. Thus, in some embodiments, the paper substrate can be surface treated by exposing the paper substrate to a corona discharge, which can convert the PDMS to silica.

[0036] In the experiments, GCIP D paper (Tokai Tokushu Paper Co., Ltd., Japan), which is known to be free of PDMS or silicone contaminants, was used at 0.81 μg / cm 2The PDMS solution was intentionally contaminated with 20 microliters (μl) of 250 ppm 9,000 g / mole molecular weight PDMS, equivalent to 100 ppm of PDMS. The PDMS solution was prepared by dissolving a known amount of PDMS in a known amount of chloroform. After doping GCIP D paper with the PDMS solution, the chloroform was evaporated. The paper was then surface-treated using various techniques (UVO, corona discharge, 196 nm laser). For example, for corona discharge, the PDMS-doped paper was exposed to 400 watts of power at 10 feet (3.048 meters) per minute (corresponding to a watt density of 21.8 watt-min / sq. ft.) for one or four passes, or 500 watts of power at 5 feet (1.524 meters) per minute (corresponding to a watt density of 54.5 watt-min / sq. ft.) for one or four passes. Watt density was calculated by dividing the power in watts by the product of the electrode width and the transport speed past the electrode. The PDMS signatures of the PDMS-doped regions were then compared across the various paper substrates either immediately after processing (time = 0) or after aging at 54% RH for two weeks. The paper substrates were analyzed using time-of-flight secondary ion mass spectrometry (TOF SIMS) to measure the presence of PDMS. TOF SIMS uses a pulsed primary ion beam and a time-of-flight mass analyzer to detect molecular ions with mass-to-charge ratios ranging from approximately m / z = 1 to approximately m / z = 10,000. To generate the PDMS signal by TOF SIMS, the sum of the PDMS-specific peaks at mass-to-charge ratios m / z of 74, 148, 207, 221, and 281 was used.

[0037] Figure 2 is a plot illustrating a comparison of TOF SIMS responses for various conditions (e.g., power, number of passes, or after 2 weeks of aging) after exposing GCIP D paper to corona discharge from a 3DT Polydyne™ Pro module conveyor equipped with a corona treatment system (part number 10036-36) with a 1.8-foot electrode width. As described above, the positive control paper was GCIP D contaminated at 250 ppm with 20 μl of 9000 molecular weight PDMS. The negative control paper was uncontaminated GCIP D paper. Further data is available for positive control paper exposed to a 400 watt corona discharge and passed through the corona discharger once at 10 feet per minute (3.048 meters); positive control paper exposed to a 400 watt corona discharge and passed through the corona discharger once at 10 feet per minute (3.048 meters) and then aged for two weeks at 54% relative humidity (RH); positive control paper exposed to a 400 watt corona discharge and passed through the corona discharger four times at 10 feet per minute (3.048 meters); and positive control paper exposed to a 400 watt corona discharge and passed through the corona discharger four times at 10 feet per minute (3.048 meters) and then aged for two weeks at 54% RH. The positive control paper included a 500-watt corona discharge and one pass at 5 feet per minute (1.524 meters), a 500-watt corona discharge and one pass at 5 feet per minute (1.524 meters), and a 54% RH aging for two weeks. The positive control paper included a 500-watt corona discharge and four passes at 5 feet per minute (1.524 meters), and a 500-watt corona discharge and four passes at 5 feet per minute (1.524 meters), and a 54% RH aging for two weeks. The data show that the PDMS signature was significantly reduced after corona treatment compared to the positive control and remained reduced even after two weeks of aging.

[0038] In further experiments, GCIP D paper was treated by exposing it to ultraviolet light. A UVOCS T10x10 ultraviolet-ozone (UVO) system was used. This system uses a low-pressure quartz mercury vapor lamp to generate UV light at wavelengths of approximately 185 nanometers (nm) and 254 nm, producing ozone and atomic oxygen. Organic pollutant molecules are excited, or dissociated, by absorption of the 254 nm UV light. The excited organic pollutants react with atomic enzymes to form volatile products such as CO2 and HO. The process is carried out at room temperature.

[0039] In yet another experiment, GCIP D paper was exposed to pulsed light from a 193 nm laser (GigaPhoton model GT64A) operating at a pulse rate of 50 Hz, directing a 0.5 watt beam at 15 millijoules (mJ) per pulse over a 1-inch diameter area on the paper surface. The exposure time was 1 minute.

[0040] Figure 3 is a plot comparing the test results for laser exposure, corona discharge exposure, and UV-ozone exposure. The positive control was GCIP D paper contaminated with 20 μl of 9000 molecular weight PDMS, and the negative control was uncontaminated GCIP D paper. The 196 nm laser data represents the positive control sample exposed to light from a 196 nm laser for 1 minute, the corona discharge data represents the positive control sample exposed to a 400 watt corona discharge at 10 feet (3.048 meters) per minute for one pass, and the UV-ozone exposure data represents the positive control sample exposed to UV-generated ozone for 5 and 10 minutes.

[0041] Further data, provided in Figure 4, show normalized silica TOF SIMS signal intensities after testing with corona discharge, a 196 nm wavelength laser, and UV ozone exposure for comparison with the data in Figure 3. TOF SIMS showed that the SiO signal increased as the PDMS signal decreased, suggesting that the PDMS was converted to silica. Rubbing the contaminated paper against Corning® Eagle XG® glass after surface treatment did not produce any visible scratches, as determined by confocal microscopy.

[0042] In some embodiments, the slip-sheet materials described herein may include a polymeric coating material. The surface of the paper substrate may be pretreated (such as by any one or more of the aforementioned corona discharge, laser, or UV ozone treatments before applying the coating material). In some embodiments, the coating material may be water-soluble. The coating material may be applied to at least one major surface of the paper substrate, although typically the polymeric coating material is applied to both major surfaces of the paper substrate. A suitable coating material may include polyvinyl alcohol (PVA), although in further embodiments, the coating material may include polyacrylic, polyvinylpyrrolidone, hydroxyethyl cellulose polymer, and / or polyethylene glycol. The polymeric material may include one or more additives. For example, in addition to the polymer base (e.g., PVA), the polymeric coating material may include one or more of an antifoaming agent, a lubricant, a hydrogen bond breaker, an antistatic agent, and / or a thickener. The total amount of additives may be such that for each part by weight of PVA, there is about 0.046 parts by weight to about 0.13 parts by weight of total additives. The polymeric coating material may further comprise water.

[0043] The polymeric coating material may have a weight average molecular weight ranging from about 8,680 g / mol to about 40,000 g / mol, e.g., from about 8,680 g / mol to about 16,654 g / mol, with a polydispersity ranging from about 7.23 to about 22.38, corresponding to a PVA coating material that is about 40% to about 98% hydrolyzed, e.g., from about 45% to about 98%, e.g., from about 50% to about 98%, e.g., from about 55% to about 98%, from about 60% to about 98%, from about 65% to about 98%, from about 70% to about 98%, from about 75% to about 98%, from about 80% to about 98%, from about 85% to about 98%, or from about 88% to about 98%, respectively. Polymer solubility was measured via the Hansen solubility parameter δ. Δδ=[(δ d,P -δ d,S ) 2 +[(δ pP -δ p,S ) 2 +(δ h,P -δ h,S ) 2 ] 1 / 2 (1) Ra 2 =4(δ D1 -δ D2 ) 2 +(δ P1 -δ P2 ) 2 +(δ H1 -δ H2 ) 2 (2) where Ra is the distance between the Hansen parameters in the Hansen space. This method is described, for example, in "Properties of Polymers" by DW Van Krevelen, 1990, Elsevier, p. 219, equation 7.13. The three parameters δ d , δ p , and δ h forms a three-dimensional space (Hansen space). The parameter δ d represents the energy from intermolecular dispersion forces, and the parameter δ p represents the energy from dipolar intermolecular forces between molecules, and the parameter δ hrepresents the energy from hydrogen bonding between molecules. The subscripts P and S refer to the polymer and solvent, respectively. The lower the Δδ value, the better the solubility and the less problematic adhesion to glass. Similarly, the closer two molecules are within the Hansen space (smaller Ra), the more likely one molecule will dissolve in the other. Polymers other than PVA that are expected to be useful in the manufacture and use of polymeric materials as paper substrate coatings for glass slipsheets may have a polymer / cellulose solubility expressed as a ratio of 5.1 or less, while polymers that are not expected to be useful may have a polymer / cellulose solubility of 18.8 or greater. Polymers with a polymer / cellulose solubility greater than about 5.1 but less than about 18.8 may be problematic (e.g., they may or may not function usefully, depending on the polymer used).

[0044] Higher molecular weights have been shown to better prevent PDMS migration compared to lower molecular weight PVA. To test the effect of PVA (polyvinyl alcohol) molecular weight on the ability of PDMS to migrate through the coating, silicon wafers were contaminated with known amounts of PDMS, dried, and then covered with PVA films of different molecular weights by spin coating. The PVA film thickness was nominally 2 micrometers for 4-88 and 4 micrometers for 4-98 and 22-88. The samples were then aged for 4 weeks and analyzed for the presence of PDMS via TOF SIMS on the PVA surface. The grades of PVA (Kuraray Corporation) used were 4-88, 4-98, and 22-88. The first number in each system refers to the molecular weight, while the second number after the hyphen refers to the PVA hydrolysis level. Thus, PVA4-88 has a weight average molecular weight of approximately 13,000 g / mole, while PVA22-88 has a weight average molecular weight of approximately 37,000 g / mole. Thus, 22-88 has a higher molecular weight than either 4-88 or 4-98. After 4 weeks of aging, 22-88, in contrast to the 4-88 and 4-98 samples, was shown to exhibit no PDMS at levels up to 250 ppm present on silicon wafers (see Figure 5).

[0045] The polymeric coating material may contain one or more antifoaming agents to minimize foaming of the polymeric coating material during pumping or mixing of the polymer. For example, stable bubbles containing water may form during pumping of highly hydrolyzed PVA (e.g., about 85% hydrolyzed PVA or higher). Antifoaming agents are chemical additives that reduce foam formation in, for example, industrial process liquids, specifically the PVA-based polymeric coating materials described herein. Generally, exemplary antifoaming agents may be insoluble oils, various silicones, alcohols, sterates, and glycols. However, suitable antifoaming agents for use in the polymeric coating materials described herein should be silicone-free to prevent potential silicone contamination of glass surfaces. The foaming properties of a PVA-based polymeric coating material can be tested by determining the amount of foam height generated after mixing or pumping. It can also be evaluated by volume or weight. The antifoaming agent concentration may be such that the polymeric coating material may contain 0.016 to about 0.03 parts by weight of antifoaming agent for every 1 part by weight of polyvinyl alcohol. Suitable defoamers include, for example, Tergitol 15-S-3 (a secondary alcohol ethoxylate nonionic surfactant available from Dow Chemical), while other suitable defoamers include Surfynol® 420 (a self-emulsifying nonionic dynamic wetting agent and acetylenic diol-based defoamer, available from Evonik), Dee Fo® 215 (a blend of wax and mineral oil, available from Muenzing Chemie), and GEO FM® VF (a 100% active nonionic water-dispersible liquid coating defoamer, available from GEO Specialty Chemicals). The defoaming effect of mixing was evaluated by adding the desired amount of defoamer to a starting volume of 200 ml of polymeric coating material and then mixing for 10 minutes. Upon completion of mixing, the change in volume was determined. The mass change of a 5-milliliter (ml) volume sample was also determined. To determine the effectiveness of pumping, an air-operated diaphragm pump with a maximum flow rate of 7 gallons / minute (26.5 liters / minute) was utilized.The air pressure was set at 50 psi (0.34 MPa) to obtain a flow rate of 1.1 to 1.5 L / min. A 20,000 mL plastic graduated cylinder was placed in the secondary container and dropped 37 inches (94 cm) above the floor. Starting with 1,000 mL, the pump was run for 10 minutes. Foaming was assessed visually.

[0046] The polymeric coating material may further comprise a lubricant (oil) to reduce the release force (e.g., coefficient of friction) and promote ease of handling. The lubricant may comprise, for example, a wax-based (e.g., natural or synthetic) lubricant such as ethylene bisstearamide (EBS). The lubricant may be present in an amount such that the polymeric coating material may comprise from about 0.05 parts by weight to about 0.625 parts by weight of lubricant for each part by weight of polyvinyl alcohol in the polymeric coating material. The effectiveness of the lubricant was measured according to ASTM D1894, Static and Kinetic Coefficient of Friction of Plastic Films and Sheeting.

[0047] In embodiments, the polymeric coating material may include one or more hydrogen bond breakers suitable for increasing the hydrophobic properties of the polymeric coating material. A hydrogen bond is an electrostatic attraction between a hydrogen atom covalently bonded to a highly electron-withdrawing "donor" atom or group and another highly electron-withdrawing atom with a lone pair of electrons. A hydrogen bond breaker can chemically break these bonds. Such hydrogen bond breakers may include alkyl ketene dimers (AKDs) or alkynyl succinic anhydrides (ASAs). The hydrogen bond breaker may be added to the polymeric coating material in an amount such that the polymeric coating material may contain from about 0.059 parts by weight to about 0.077 parts by weight of the hydrogen bond breaker for each part by weight of polyvinyl alcohol. The effectiveness of the hydrogen bond breaker was evaluated by measuring the contact angle of water on the surface of the coated paper as a function of time. This method is described in "Improving the Barrier Properties of Packaging Paper by Polyvinyl Alcohol Based Polymer Coating - Effect of the Base Paper and Nanoclay," Polymers, 2021, 13, 1334, p. 5, Figure 1(a), the contents of which are incorporated herein by reference. Base papers with base PVA coatings, with or without hydrogen bond breakers, were evaluated for water permeability by determining via video when a 2 microliter drop of water was absorbed into the coated paper and disappeared, as described in the above reference.

[0048] To reduce the electrostatic adhesion of paper substrates to glass surfaces and to reduce the electrostatic attraction of particles to the glass surface, antistatic agents can be added to the polymer coating material to, for example, reduce or eliminate the buildup of static charge. Static charge can be generated, for example, by the triboelectric effect. Antistatic agents can include, for example, poly(4-styrene sulfonate) or amine ethoxylates, such as cocoamine ethoxylate (e.g., Etomene C25A, available from Nouryon, Amsterdam, The Netherlands), tallowamine ethoxylate, or oleylamine ethoxylate. The antistatic agent can be added in an amount such that for every 1 part by weight of polyvinyl alcohol, the polymer coating material can contain 0.067 parts by weight of antistatic agent.

[0049] In embodiments, the polymeric coating material may include a thickening agent (e.g., alginate) to adjust the viscosity of the polymeric coating material and allow for large-scale production. The thickening agent may increase the viscosity of the liquid without substantially changing other properties of the liquid. For example, the concentration of the thickening agent may be such that for each part by weight of polyvinyl alcohol, the polymeric coating material may include about 0.03 parts by weight to about 0.12 parts by weight of thickening agent. Suitable thickening agents include alginate, an anionic polysaccharide made from guluronic acid and mannuronic acid.

[0050] In some embodiments, the polymer coating may include a PDMS inhibitor that inhibits PDMS migration. Molecular diffusion of PDMS in a PVA coating occurs due to a chemical potential or concentration gradient of PDMS across the coating, and the driving force may be determined by: ∂G=A(γpdms-(γsurface), (3) In the equation, ∂G represents the change in Gibbs free energy, A represents the surface area, γ represents the surface energy of PDMS, and γ represents the surface energy of the coating surface.

[0051] PDMS inhibitors counteract the PDMS concentration gradient and thus hinder the diffusion of PDMS. PDMS inhibitors can be water-soluble and therefore easily washed from glass surfaces. The PDMS inhibitor additive can be formulated so as not to affect coating viscosity. Furthermore, PDMS inhibitors can reduce the surface tension of coatings, thereby improving their wetting. Additionally, PDMS inhibitors can have antifoaming capabilities and can be used in combination with other antifoaming agents. PDMS inhibitor-based coatings on paper substrates can significantly reduce particle counts after washing of glass substrates interleaved with coated paper compared to using paper alone as the interleaving material. Classes of compounds that meet these conditions are water-soluble polymers containing a PDMS fraction, such as PEG-dimethicone, PEG / PPG-dimethicone, and dimethylsiloxane-ethylene oxide copolymer. The amount of inhibitor added to polymer (e.g., PVA) coatings can vary from about 0.001% to about 2% by weight. The aqueous coating can be a single component or can contain a mixture of hydrolyzed polyvinyl acetate (polyvinyl alcohol) compounds. Other suitable polymers include polyacrylics, polyvinylpyrrolidones, hydroxyethyl cellulose polymers, and polyethylene glycols. However, the coating is not limited to these polymers and can be extended to other classes of polymers and non-polymeric materials. The PDMS inhibitor can contain PDMS fragments as side chains or within the molecular structure of the main chain.

[0052] Figure 6 shows transmission Fourier transform infrared spectroscopy (FTIR) data for Corning Eagle XG glass slides with PDMS inhibitor deposited at a 250 ppm level using a chloroform solution. WSS1 represents a dimethylsiloxane (60%-70% ethylene oxide) block copolymer, WSS2 represents a dimethylsiloxane (80-85% ethylene oxide) block copolymer, and CS9K represents a 9000 molecular weight silicone oil. C—H bands from both the silicone oil (9K) and the inhibitor polymer are visible. Figure 7 shows FTIR data for an EXG glass slide with the inhibitor polymer after rinsing the slide with deionized (DI) water for 30 seconds. C—H bands are observed for the control silicone-treated glass slide. C—H bands are absent from the slide treated with the inhibitor polymer. This clearly demonstrates that the PDMS inhibitor polymer can be easily cleaned from glass substrates (e.g., Eagle XG glass), whereas silicone oil cannot be removed by rinsing with DI water.

[0053] Figure 8 shows the normalized TOF SIMS intensity for Eagle XG glass slides treated with a control siloxane (CS9K) and the PDMS inhibitor polymer, with and without cleaning (rinsing). The data demonstrate that the PDMS inhibitor polymer is washable, with no peaks indicative of PMDS remaining after a 30-second rinse with DI water. Two-inch x two-inch glass slides were immersed in chloroform solutions containing different levels of the PDMS inhibitor polymer for one minute. The glass slides were removed, dried in air, and then blown dry with nitrogen gas. The glass slides were then rinsed in DI water for 30 seconds and then blown dry with nitrogen gas.

[0054] Figure 9 shows that the addition of PDMS inhibitor can reduce the surface tension of a 25 wt % PVA aqueous solution (4-88, Kuraray) coating. Reducing the surface tension improves the coating's spreading ability (see Equation 3). This may facilitate a thin, conformal coating of slip sheets to protect the glass surface. Furthermore, a thin coating may ensure reduced coating material costs. Figure 10 shows the defoaming ability of the inhibitor polymer, as indicated by the volume increase of the PVA coating solution containing the PDMS inhibitor, indicating that the inhibitor polymer itself can function as a defoamer for the PVA coating. For the data in Figure 10, the coating solution was stirred in a container at 500 revolutions per minute (rpm) for 20 minutes. The control sample was a pure 25 wt % PVA coating solution without the PMDS inhibitor. Additionally, when other defoamers (e.g., Surfynol MD20) and surfactants (e.g., Surfynol 465) are added to the PVA and PDMS inhibitor system, the combination exhibits a synergistic effect in defoaming ability. Figure 11 illustrates that the addition of 1 wt% inhibitor polymer to the PVA coating does not affect the viscosity of the PVA-based coating. However, as demonstrated in Example 3, a much smaller amount of PDMS inhibitor polymer may be sufficient to prevent PDMS migration during coating. S=γsoln. / air((Cosθobs / (r)-1) (4) where S represents the spreading parameter of the coating on the substrate paper (e.g., slip sheet), γsoln. / air is the surface tension of the coating solution (e.g., PVA solution), r is the ratio of the actual contact area to the apparent contact area (also known as the roughness ratio) measured by a surface topography measurement tool, such as a scanning confocal microscope (e.g., Keyence VK-X200) or an atomic force microscope, and cosθobs is the measured contact angle (using a goniometer) of the coating solution on the slip sheet. In Equation 4, if S<0, the coating partially wets the surface; the smaller the magnitude of the negative quantity, the better the coating spreads. If S≥0, the coating completely wets the surface.

[0055] To test the effect of adding a PDMS inhibitor to a PVA coating on its PDMS barrier properties, a 4 x 4 inch silicon wafer was contaminated with 250 ppm PDMS, dried, and then coated with a 25 wt% polyvinyl alcohol coating (4-88, 88% hydrolyzed PVA, Kuraray) by spin coating. A 25 wt% PVA coating was used as a control. The PDMS inhibitor was added to the 25 wt% PVA coating at amounts of 0.1 wt% and 0.5 wt% to evaluate its effect. The samples were then aged for 6 and 13 weeks. The samples were then analyzed using water contact angle measurements for the presence of PDMS. The data are presented in Figures 13-16. For the control coating, PDMS migrated to the coating surface after both 6 and 13 weeks of aging. However, for the PVA coating containing the PDMS inhibitor, there was no noticeable increase in the water contact angle, demonstrating the excellent PDMS barrier properties of the PDMS inhibitor-containing coating. PVA4-88 has a weight average molecular weight of about 13,000.

[0056] To test the effect of transportation on particle migration from the package insert to the display glass surface, vibration tests were conducted. Corning Eagle XG glass specimens measuring 4 x 4 inches were placed in a vibration chamber at a particle count of 1 particle / cm. 2The glass specimens were first cleaned to less than 100%. Particles on the glass specimens were counted in a cleanroom using a Toray laser particle counter. Two stacks were prepared: 1) GCIP D paper (control) alternating with Corning Eagle XG glass specimens, and 2) coated slipsheet paper alternating with Corning Eagle XG glass specimens. The stacks were aged overnight at 54% controlled relative humidity before the experiment. One stack of 20 Corning Eagle XG glass specimens interleaved with GCIP D paper was placed in a simulated shipping device secured to a vibration table unit, with the plane of the stack of glass specimens positioned at a 72-degree angle. The stack was then vibrated for two hours using an Unholtz-Dickie Corporation vibration system in accordance with Telecordia GR-63 standards. The stack was then removed from the simulated shipping device, and the number of particles on the surface after vibration, referred to as "after vibration," was counted using a Toray particle counter. The glass specimens were then washed in a detergent bath for 1 minute and a water bath for 1 minute, followed by a rinse and spin-dry step. The glass specimens were then counted a third time for particles using a Toray particle counter; these values ​​are designated "after vibration and washing." To determine the reliability of the data related to the coated paper, a control experiment for GCIP D was performed. Figures 16-17 show particle density data for each step of the vibration experiment process. In Figure 17, catalyst paper was coated with 25 wt% PVA4-88, WSS2 (0.5 wt%), antifoam (Surfynol MD20, 0.25 wt%), and surfactant (Surfynol 465, 0.25 wt%). The paper was coated using a bar coating technique at 200 mm / s. The data show that the particle count of the PVA-coated paper after washing was 77% lower than that of GCIP D.

[0057] The polymeric coating materials described herein can be applied to a paper substrate by any suitable means, including, but not limited to, rolling, spraying, dipping, doctor blade, etc. The polymeric coating material can then be cured, for example, by air drying, to produce a slip-sheet material. In embodiments, the polymeric coating material is applied uniformly to the paper substrate surface. That is, the polymeric coating material should be continuous across the paper substrate surface without gaps (i.e., without uncoated areas on the paper substrate major surfaces). In embodiments, the polymeric coating material can be applied to each major surface at a thickness ranging from about 2 micrometers to about 10 micrometers, e.g., from about 3 micrometers to about 9 micrometers, e.g., from about 4 micrometers to about 8 micrometers.

[0058] Returning to Figure 1, Figure 1 shows a perspective view of an exemplary slip-sheet material 10 according to embodiments disclosed herein. In the embodiment shown, slip-sheet material 10 further includes a polymeric coating material 18 (e.g., a PVA-based coating material disclosed herein) applied to at least one major surface of paper substrate 12. Polymeric coating material 18 may be applied to both major surfaces, i.e., first major surface 14 and second major surface 16.

[0059] FIG. 18 is a cross-sectional end view of glass substrates 20 arranged in a stack, with interleaf material 10 disposed between adjacent glass substrates in the stack. Each glass substrate includes a first major surface 22 and a second major surface 24 opposite the first major surface 22. The second major surface 24 may be generally parallel to the first major surface 22. The first and second major surfaces 22, 24 are joined by edge surfaces 26. The number of edge surfaces 26 depends on the shape of the glass substrates 20. For example, a rectangular glass substrate 20 includes four edge surfaces 26. The interleaf material 10 may be positioned to overhang the edge surfaces 26 by an overhang distance 28. A typical overhang distance is approximately 50 millimeters. However, the overhang distance 28 of one edge surface 26 need not be equal to the overhang distance of another edge surface 26. The slip sheet material shown in FIG. 18 is a coated slip sheet material, however, the slip sheet material can be an uncoated but surface treated (e.g., corona discharge treated, laser treated, and / or UV ozone treated) paper.

[0060] The glass substrate 20 can include a variety of glass compositions. For example, embodiments disclosed herein include those in which the glass substrate 20 includes an alkali-free glass composition, which can include, for example, SiO2 in a range of about 58 weight percent (wt %) to about 65 wt %, Al2O3 in a range of about 14 wt % to about 20 wt %, B2O3 in a range of about 8 wt % to about 12 wt %, MgO in a range of about 1 wt % to about 3 wt %, CaO in a range of about 5 wt % to about 10 wt %, and SrO in a range of about 0.5 wt % to about 2 wt %. The glass substrate 20 may also include an alkali-free glass composition including SiO in the range of about 58 wt % to about 65 wt %, AlO in the range of about 16 wt % to about 22 wt %, BO in the range of about 1 wt % to about 5 wt %, MgO in the range of about 1 wt % to about 4 wt %, CaO in the range of about 2 wt % to about 6 wt %, SrO in the range of about 1 wt % to about 4 wt %, and BaO in the range of about 5 wt % to about 10 wt %. Additionally, the glass substrate 20 may include an alkali-free glass composition including SiO in the range of about 57 wt % to about 61 wt %, AlO in the range of about 17 wt % to about 21 wt %, BO in the range of about 5 wt % to about 8 wt %, MgO in the range of about 1 wt % to about 5 wt %, CaO in the range of about 3 wt % to about 9 wt %, SrO in the range of about 0 wt % to about 6 wt %, and BaO in the range of about 0 wt % to about 7 wt %. The glass substrate 20 may also include an alkali-containing glass composition, which may include about 55% to about 72% by weight of SiO, about 12% to about 24% by weight of AlO, about 10% to about 18% by weight of NaO, about 0% to about 10% by weight of BO, about 0% to about 5% by weight of KO, about 0% to about 5% by weight of MgO, and about 0% to about 5% by weight of CaO, and the alkali-containing glass composition may also include about 1% to about 5% by weight of KO and about 1% to about 5% by weight of MgO in certain embodiments. However, the glass substrate 20 is not limited to the aforementioned glass compositions and may include any number of other glass compositions.

[0061] In embodiments, the thickness 30 of the glass substrate 20 defined between the first major surface 22 and the second major surface 24 can be about 5 millimeters or less, for example, in the range of about 0.1 millimeters to about 5 millimeters, including ranges of about 0.1 to 4 millimeters, 0.1 to about 3 millimeters, 0.1 millimeters to about 2 millimeters, 0.1 to about 1 millimeter, 0.1 to about 0.7 millimeters, or 0.1 to about 0.3 millimeters. [Example]

[0062] The embodiments disclosed herein are further illustrated by the following non-limiting examples.

[0063] Example 1 Interleaf material (e.g., GCIP D uncoated paper) comprising a paper substrate (NRD, a recycled newspaper product by Delta Paper, Burlington, New Jersey, USA) coated with the PVA-based polymer coating material described herein was placed on clean Corning® Eagle XG® glass substrates (having a major surface area of ​​approximately 10.2 centimeters by 10.2 centimeters) at 54% relative humidity and 20°C for 8 weeks. The glass substrates were stacked horizontally, with the interleaf material positioned between adjacent glass substrates, i.e., layers of interleaf material alternated with layers of glass substrate. A weight was placed on top of stacks consisting of 1 to 10 glass substrates to mimic the pressures found in actual shipping configurations. The weight was approximately 1.8 kilograms and covered the surface of the stack. The glass substrate and slip-sheet material were then separated, and the glass substrate was subsequently washed for approximately 1 minute with an aqueous solution containing approximately 1% Semiclean KG (produced by Yokohama Oil & Fats Industries Co., Ltd.), followed by rinsing with deionized water for 1 minute, which was repeated twice. The water contact angle of the major surface of the glass substrate in contact with each slip-sheet material was measured by measuring the angle of a 2-microliter water droplet formed on the glass surface, as determined by a Kruss DSA100E drop shape analyzer (five measurements per sample), before and after the washing and rinsing steps, and the results are shown in FIG. 19. As can be seen from FIG. 19, the water contact angle significantly decreased from a high of approximately 80 degrees before washing and rinsing to less than 10 degrees after washing and rinsing. A water contact angle of less than approximately 10 degrees indicates that the major surface of the glass substrate has acceptable hydrophilicity.

[0064] Example 2 The surfaces of the slip sheet materials were examined for the presence of PDMS using TOF SIMS. In addition to GCIP D uncoated paper and NRD coated paper, NVA (available from Resolute Forest Products, Montreal, Quebec, Canada, 48.8 g / m 2and recycled newsprint labeled NVRe (available from Alberta Newsprint, Alberta, Canada, and having a basis weight of 45 g / m 2 (having a basis weight of 1000 ppm or less) were tested. The designations "A" and "B" indicate opposite surfaces of the slip-sheet material. The purpose of the test was to determine whether the PVA-based polymer coating described herein, when applied to a paper substrate, formed a sufficient barrier to prevent PDMS contamination of the glass substrate to which the slip-sheet material was applied. The results are shown in Figure 20 and demonstrate a significant reduction in PDMS contamination of the slip-sheet material protected with the PVA-based polymer coating material compared to the uncoated paper substrate.

[0065] Example 3 Interleave material (e.g., uncoated GCIP D) including a paper substrate coated with the PVA-based polymer coating material described herein was placed on a glass substrate (having a major surface area of ​​approximately 10.2 cm × 10.2 cm) for a period of one day at a temperature of approximately 20°C in an atmosphere having a relative humidity of approximately 54%. Twenty clean Corning® Eagle XG® glass substrates were interleaved with paper substrates (NRD, GCIP D, NVRe, and NVA), including the paper substrate (NRD) coated with the PVA-based polymer coating material described herein. The stack of glass substrates including the interleave material disposed between the glass substrates was subjected to a vibration cleaning test in which the stack was vibrated at 50% relative humidity for two hours using Telecordia standard (GR63 Transportation Vibration, Section 4.4.5). The interleave material was then removed, and the number of particles on the glass substrates before and after cleaning was counted using a Toray Engineering Model HS830 particle counter. The glass substrates were then ultrasonically cleaned at 50°C using 1% Semiclean KG (Yokohama Oil & Fats) for 1 minute, followed by a 1-minute rinse with DI water. After rinsing, the particles were recounted. As can be seen from Figure 21, after cleaning, each major surface of the glass substrates contained less than about 0.75 particles (L) greater than about 0.75 micrometers in diameter, less than about 0.6 particles (M) greater than about 0.5 micrometers to about 1 micrometer in diameter, and less than about 0.3 particles (S) greater than about 0.3 micrometers to about 0.5 micrometers in diameter. The coated NRD interleaf material included low molecular weight PVA (6000 molecular weight, 80% hydrolyzed) and high molecular weight PVA (molecular weight ranging from about 146,000 to about 186,000, hydrolyzed from about 86% to about 89%).

[0066] Example 4 Figures 22-24 detail the data from Example 3. Figures 22-24 show particle counts of greater than 50 particles per square centimeter and greater than 90 particles per square centimeter greater than 1 micrometer in diameter for the GCIP D paper substrate, uncoated NRD paper, and NRD paper substrate coated with the PVA-based coating material described herein. However, after cleaning, the particle density on the glass surface protected by the PVA-based interleaf material decreased to a level approximately equal to the particle density before the vibration test began. The data illustrate the ease of particle removal after deposition compared to glass protected by an interleaf material that does not include the PVA-based coating material.

[0067] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Thus, the present disclosure is intended to cover such modifications and variations, provided they come within the scope of the appended claims and their equivalents.

Claims

1. 1. A polymeric coating material for a paper substrate, comprising: Polyvinyl alcohol, 1. A polymeric coating material comprising: for each part by weight of polyvinyl alcohol, about 0.016 parts to about 0.03 parts by weight of an antifoaming agent and about 0.05 parts to about 0.625 parts by weight of a lubricant.

2. 10. The polymeric coating material of claim 1, further comprising 0.067 parts by weight of an antistatic agent for every 1 part by weight of polyvinyl alcohol.

3. 3. The polymeric coating material of claim 1 or 2, further comprising from about 0.059 parts by weight to about 0.077 parts by weight of a hydrogen bond breaker for each part by weight of polyvinyl alcohol.

4. The polymeric coating material of any one of claims 1 to 3, further comprising a PDMS inhibitor.

5. The polymeric coating material of claim 4 , wherein the PDMS inhibitor is water soluble.

6. 6. The polymeric coating material of claim 4 or 5, wherein the PDMS inhibitor additive comprises at least one of PEG-dimethicone, PEG / PPG-dimethicone, or dimethylsiloxane-ethylene oxide copolymer.

7. An interleaf material for separating glass substrates, comprising: a paper substrate comprising at least one of lignin or cellulose, a first major surface, and a second major surface opposite the first major surface; a coating disposed on at least one of the first major surface or the second major surface of the paper substrate, the coating comprising: Polyvinyl alcohol, 1. A slip-sheet material comprising: for each part of polyvinyl alcohol, about 0.016 parts to about 0.03 parts by weight of an antifoaming agent and about 0.05 parts to about 0.625 parts by weight of a lubricant.

8. The polymeric coating material of claim 7 further comprising a PDMS inhibitor.

9. 9. The polymeric coating material of claim 8, wherein the PDMS inhibitor comprises at least one of PEG-dimethicone, PEG / PPG-dimethicone, or dimethylsiloxane-ethylene oxide copolymer.

10. The polymeric coating material of claim 8 , wherein the PDMS inhibitor is water soluble.

11. The slip-sheet material of any one of claims 7 to 10, wherein the coating comprises about 0.067 parts by weight of an antistatic agent for every 1 part by weight of polyvinyl alcohol.

12. 12. The slip-sheet material of claim 11, wherein the antistatic agent comprises poly4-styrene sulfonate or an amine ethoxylate.

13. 13. The slip-sheet material of any one of claims 7 to 12, wherein the coating comprises from about 0.059 parts by weight to about 0.077 parts by weight of a hydrogen bond breaker for every part by weight of polyvinyl alcohol.

14. 14. The slip-sheet material of claim 7, wherein the coating on the at least one of the first major surface or the second major surface has a thickness in the range of about 2 micrometers to about 10 micrometers.

15. 14. The slip-sheet material according to any one of claims 7 to 13, wherein the coating is a continuous coating on the at least one of the first major surface or the second major surface.

16. 16. The slip-sheet material of claim 15, wherein the first major surface and the second major surface are coated with the coating.

17. The slip sheet material according to any one of claims 7 to 16, wherein the slip sheet material is in roll form.

18. The slip sheet material according to any one of claims 7 to 17, wherein the thickness of the slip sheet material is about 200 micrometers or less.

19. 19. The slip-sheet material according to any one of claims 7 to 18, wherein the paper substrate has an MD tensile strength of at least about 2.86 kilograms per centimeter of width of the paper substrate, as measured in accordance with TAPPI T-494.

20. 20. The slip-sheet material of any one of claims 7 to 19, wherein the paper substrate has a CD tensile strength of greater than or equal to about 0.7 kilograms per centimeter of width of the paper substrate as measured according to TAPPI T-494.

21. 21. The slip sheet material according to any one of claims 7 to 20, wherein the tear strength of the paper substrate is at least 18 grams for 8 layers as measured according to TAPPI T-414.

22. The weight of the paper substrate, expressed in mass in grams per square meter, is about 40 g / m ２ ~Approx. 120g / m ２ The slip-sheet material according to any one of claims 7 to 21, in the range of

23. 1. A stack of glass substrates, 23. A stack of glass substrates comprising a plurality of glass substrates arranged in the stack, wherein adjacent glass substrates of the plurality of glass substrates are separated by the slip-sheet material according to any one of claims 7 to 22.

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