WO2016123602A1

WO2016123602A1 - Coating compositions and methods of making and using same

Info

Publication number: WO2016123602A1
Application number: PCT/US2016/015913
Authority: WO
Inventors: Bryn WILKE
Original assignee: Leica Biosystems Richmond Inc
Current assignee: Leica Biosystems Richmond Inc
Priority date: 2015-01-31
Filing date: 2016-02-01
Publication date: 2016-08-04
Anticipated expiration: 2017-07-31

Abstract

A coating composition and methods of making and using the coating compositions. The compositions comprise an epoxy-based, thermally-curable, screen-printing ink, thermal silica, hydrophobic silica, and, optionally, solvent. The compositions provide thermally-cured layers of the composition disposed on a glass slide. Information can be deposited (e.g., ink-jet printed or written using a solvent resistant pen) on the thermally-cured layers.

Description

COATING COMPOSITIONS AND METHODS OF MAKING AND USING SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. provisional patent application no. 62/110,491, filed January 31, 2015, the disclosure of which is incorporated herein by reference.

FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to coating compositions and methods of making and using the coating compositions. More particularly, the disclosure relates to compositions comprising one or more epoxy-based, thermally-curable, screen-printing ink, one or more thermal silica, and one or more hydrophobic silica.

BACKGROUND OF THE DISCLOSURE

[0003] Typical microscope slides of the prior art include a "frosted" portion as a marking surface. This frosted area is created by sandblasting, acid etching, mechanical abrading, or other method of roughening the surface of the glass so that a permanent marking surface is created to accept marking by pen, pencil, printer, or other marking instrument. All of these techniques create a frosted surface by removing material from the glass surface, therefore necessarily resulting in a marking surface which is recessed from, or certainly no higher than, the surface of the glass slide. Furthermore, such frosted glass, while providing a matte surface on the glass, does not typically result in a marking surface having a pronounced background to contrast with information to be written thereon.

[0004] Glass microscope slides can be screen printed to enable identifying information to be printed directly to or on the microscope slide. This microscope slide identifying information can include, for example, a patient name or identification, a type of sample, tests to be performed, tests that have been performed, or other data known to those skilled in the art. This information or data may be in the form of alphanumeric characters, a barcode (e.g., linear, matrix, or other two-dimensional barcode), a logo, a symbol, or other text or graphics. The identifying information may be used to, for example, archive samples, track samples, determine what testing or processes have been performed on a sample, or check in/check out samples. Usually, the identifying information must withstand stains, xylene, alcohol, or other chemicals frequently used while processing the microscope slides. [0005] For example, a screen printed ink is appli

inkjet-printed ink is then applied to the screen printed ink. The screen-printed ink is thermally cured and the inkjet-printed ink is cured using ultraviolet light. The inkjet-printed ink includes a pattern with identifying information for the microscope slide or the sample contained on the microscope slide. However, this arrangement has drawbacks. The inkjet- printed ink spreads, rendering the identifying information incomplete or illegible. The inkjet- printed ink also is raised, rendering it prone to wear, scratching, or removal. Such microscope slides also may be prone to retaining dye used during microscope slide processing. Based on these drawbacks, there exists an ongoing and unmet need for an improved screen-printing ink for microscope slides.

SUMMARY OF THE DISCLOSURE

[0006] The present disclosure provides a coating composition comprising: one or more epoxy -based thermally curable screen-printing ink; one or more thermal silica; and one or more hydrophobic silica. The coating composition can also comprise one or more solvent, one or more silane, one or more pigment, or a combination thereof. The silane can be present at 1-5% by weight. The epoxy -based thermally curable screen-printing ink can be a two- component epoxy -based thermally curable screen-printing ink. For example, the two- component epoxy-based thermally curable screen-printing ink is Enthone 60 Part A and Enthone 60 Part B. The ratio of Enthone 60 Part A to Enthone 60 Part B can be 90: 10. The thermal silica can be ACEMATT^® TS. The hydrophobic silica can be Sylophobic 200. The ratio of epoxy-based thermally curable screen-printing ink to thermal silica can be 10. The ratio of epoxy-based thermally curable screen-printing ink to hydrophobic silica can be 10:3. The ratio of thermal silica to hydrophobic silica can be 1 :0.75 to 1 0. The ratio of thermal silica to hydrophobic silica can be 1 : 1.2.

[0007] The present disclosure also provides a glass slide having a layer comprising a thermally-cured composition of the present disclosure disposed on at least a portion of at least one surface of the glass slide. The glass slide can have at least one alpha numeric character, bar code, and/or graphic printed on the exterior surface of the layer. The glass slide can be a microscope slide. The glass slide can also comprise a cellular or molecular sample. The glass slide can also comprise a histology sample. BRIEF DESCRIPTION OF THE FIGURES

[0008] Figure 1. Image of Fisherbrand™ InkJet Plus white slide with information ink- jet printed on the slide (PRIOR ART).

[0009] Figure 2. Image of Snowcoat® white slide with information ink-jet printed on the slide (PRIOR ART).

[0010] Figure 3. Examples of slides for visual comparative evaluation with respect to dye pickup and slides of the instant disclosure before and after contact with dye.

[0011] Figure 4. Example of slides exhibiting printed information adhesion issues.

[0012] Figure 5. Examples of slides for visual comparative evaluation.

[0013] Figure 6. Examples of slides for visual comparative evaluation with respect to dye pickup.

[0014] Figure 7. Readability for example slides of instant disclosure.

[0015] Figure 8. Scores for Digital Readable/Scan Rate for example slides of instant disclosure.

[0016] Figure 9. Example of prediction profiler for scan rate based on particle loading. The x-axis represents the ACEMatt and Sylophobic components and their associated percent values. Based on a value of 3% for ACEMatt and 7% for Sylophobic, it can be predicted that the response rate will achieve a perfect scan rate score of 5 (Desirability = 1). This demonstrates that with increasing percentage of both ACEMatt and Sylophobic, the scan rate improves.

[0017] Figure 10. Scores for Adhesion for example slides of instant disclosure.

[0018] Figure 11. Scores for Dye Pickup for example slides of instant disclosure.

[0019] Figure 12. Example of prediction profilers for various properties of slides of instant disclosure. The x-axis represents the various components and their associated percent values. Based on these values response scores can be predicted as seen on the y-axis. The y- axis represents the responses that were scored. The three numbers listed to the right of the response represent the predicted response score and the range over which the predicted score can vary (the numbers within the brackets).

[0020] Figure 13. Images of an example slide of the present disclosure (coating composition comprises 3 :2.5 ACEMatt to Sylophobic and Markem ink) that shows application of identifying information with an Leica IPS inkjet printer.

[0021] Figure 14. Sample H29 (2:5 ratio of ACEMatt to Sylophobic) before contact with dye (left) and after contact with dye (right). [0022] Figure 15. Sample H9 (3 :2.5 ratio of ACI

with dye (left) and after contact with dye (right).

[0023] Figure 16. Sample H27 (3 :7 ratio of ACEMatt to Sylophobic) before contact with dye (left) and after contact with dye (right).Note reduced screen ink adhesion as evidenced by missing ink on left center portion of dyed slide.

[0024] Figure 17. Sample H14 (0.5:2.5 ratio of ACEMatt to Sylophobic) before contact with dye (left) and after contact with dye (right).

[0025] Figure 18. Sample H23 (0.5:2.5 ratio of ACEMatt to Sylophobic) before contact with dye (left) and after contact with dye (right).

[0026] Figure 19. Example of composition blending and slide labeling processes.

[0027] Figure 20. Example of performance testing process.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0028] The present disclosure provides coating compositions and methods of making and using such compositions. For example, the coating compositions are printed on glass slides (e.g., glass microscope slides).

[0029] The present disclosure is based on the unexpected and surprising result that the instant coating compositions comprising both thermal silica and hydrophobic silica provide a thermally-cured layer of coating composition that exhibits both desirable adhesion to a glass slide and spreading characteristics with respect to printing on the exposed surface of the layer.

[0030] In an aspect, the present disclosure provides coating compositions. The coatings constitute a "Direct Apply" ink technology that does not require use of the vapor blast process. The coating compositions are thermally curable. The coating compositions are also referred to herein as screen-printing compositions and paints.

[0031] The coating compositions comprise an epoxy-based, thermally-curable, screen-printing ink, thermal silica, hydrophobic silica, and, optionally, solvent. In various embodiments, the coating compositions consist essentially of or consist of an epoxy-based, thermally-curable, screen-printing ink, thermal silica, hydrophobic silica, and, optionally, solvent.

[0032] For example, the coating compositions have the following composition:

Thermal silica

Hydrophobic silica 2

solvent 23

The % by weight values are based on the total weight of the coating composition.

[0033] The coating compositions comprise epoxy-based, thermally-curable, screen- printing inks. The epoxy-based, thermally-curable, screen-printing inks comprise, for example, epoxy resin, hardener, pigment, and one or more filler. Examples of suitable hardeners include amines (e.g., tetraethylene tetramine), alcohols, thiols, acids, and anhydrides (e.g., hydrohexaphthalic anhydride). Examples of suitable fillers include titanium dioxide and kaolin. Suitable epoxy-based, thermally-curable, screen-printing inks are known in the art. Examples of epoxy-based, thermally-curable, screen-printing inks include 60 Series two-component legend ink available from Enthone, 4166 ink series inks available from Markem Imaje, NZE series inks available from Nazdar, and Uni glaze inks available from Union Ink. For example, the epoxy-based, thermally-curable, screen-printing ink is a two- component ink (e.g., Enthone 60-series epoxy-based, thermally-curable, screen-printing ink). For example, the epoxy-based, thermally-curable, screen-printing ink is present in the composition at 70% by weight to 95 % by weight, including all integer % values and ranges therebetween. It may be desirable to use an epoxy-based thermally curable screen-printing ink that provides a matte finish. Suitable epoxy-based, thermally-curable, screen-printing inks are commercially available.

[0034] The coating compositions comprise thermal silica. The thermal silica is made by thermal processes and is not a wet process product. For example, the thermal silica has an average agglomerate particle size (e.g., measured by light scattering conforming to ISO

13320-1) of 9.5 microns (+/-5 microns). For example, the thermal silica has a specific surface area (e.g., measured by N₂ adsorption conforming to ISO 9277) of 250 m²/g (+/- m²/g). An example of a thermal silica is ACEMATT^® TS 100 (available from Evonik). For example, the thermal silica is present in the composition at 0.5% to 4 %, including all 0.1% values and ranges therebetween. For example, the thermal silica is present in the composition at 0.5% to 4 % by weight, including all 0.1% values and ranges therebetween. In an embodiment, the thermal silica is not surface treated. Suitable thermal silicas are known in the art. Suitable thermal silicas are commercially available.

[0035] The coating compositions comprise hydrophobic silica. An example of a hydrophobic silica is Sylophobic 200 (available from Fuji). For example, the hydrophobic silica is present in the composition at 0.5% by weight to

values and ranges therebetween. Suitable hydrophobic silicas are known in the art. Suitable hydrophobic silicas are commercially available.

[0036] In an embodiment, the hydrophobic silica is surface-modified silica. For example, the hydrophobic-silica is silica surface modified with a hydrophobic moiety such as an alkyl moiety. The alkyl-modified silica may be formed by reacting silica (e.g., amorphous silica) with a polyalkyl siloxane.

[0037] The thermal silica and hydrophobic silica may be present in the coating composition at a particular ratio. For example, the ratio of thermal silica to hydrophobic silica is 1 :0.75 to 1 :20, including all 0.1 ratio values and ranges therebetween. In an embodiment, the ratio of thermal silica to hydrophobic silica is 1 :2 to 1 0.

[0038] The coating compositions may comprise a silane. Examples of suitable silanes include, 3 -aminopropyltrimethoxy silane (APTMS) and the like. For example, the silane is present in the composition at 0% to 2 %, including all 0.1 % values and ranges therebetween. For example, the silane is present in the composition at 1% to 2 %. Suitable silanes are known in the art. Suitable silanes are commercially available.

[0039] The coating compositions may comprise a solvent. Use of a particular amount of solvent can result in a desired viscosity of the coating composition. The solvent may be a mixture of solvents. Examples of suitable solvents include 2-butoxyethanol, ethylene glycol monobutyl ether acetate, 2-butoxyethanol, diethylene glycol monoethyl ether acetate, heavy aromatic solvent naphtha, 2-ethoxyethyl acetate, naphthalene, and mixtures thereof. For example, the solvent(s) is/are present in the composition at 0% to 30 %, including all integer % values and ranges therebetween. For example, the solvent(s) have a boiling point of 145 °C to 245 °C. For example, the solvent is XO Thinner (available from Markem Imaje). Suitable solvents are known in the art. Suitable solvents are commercially available.

[0040] The viscosity of the coating composition can vary. For example, the viscosity of the coating composition is 5,500 centipoise (cP) to 50,000 centipoise, including all integer centipoise values and ranges therebetween. In an embodiment, the viscosity of the coating composition is 7500 centipoise +/- 1000 centipoise. The viscosity can be measured by, for example, a viscometer.

[0041] The composition may comprise colorants. For example, the composition comprises tints or pigments. In an embodiment, the composition is white.

[0042] Without intending to be bound by any particular theory, it is considered that the disclosed silica components (i.e., particular combination of thermal silica and hydrophobic silica) of the coating compositions of the pi

cured layer of the coating composition on a glass slide having both a desirable adhesion to a glass slide and a surface that can be printed (e.g., ink-jet printed) on such that the printed ink has desirable spreading (i.e., the printing provides legible alpha numeric characters). Also, it is considered that the disclosed silica components of the instant coating compositions provide a layer on a glass slide having desirable dye retention (e.g., retention of substantially no or no measurable amount of dye as measured by visual analysis against photographic standards).

[0043] In an embodiment, the thermally-cured layer of the coating composition does not retain any measureable amount of dye. For example, the amount of dye that is retained is measured by visual analysis against photographic standards. In an embodiment, the layer does not retain dye such that the as printed color of the layer (e.g., white) is altered as determined by visual inspection. In an embodiment, the layer does not exhibit undesirable Histopen fading when subjected to acids and/or bases. In an embodiment, the layer exhibits Histopen fading that is equivalent to or less than that of existing slides (benchmark slides).

[0044] In an aspect, the present disclosure provides methods of making coating compositions. The methods are based on the addition of the silica components of the composition to the epoxy -based thermally curable screen-printing ink. For example, the silica components of the composition are added to the epoxy -based thermally curable screen- printing ink at a selected viscosity. An example of a method for making a coating

composition is provided in Example 2.

[0045] In an embodiment, a method of making the screen printing composition comprises: a) combining the epoxy-based, thermally-curable, screen-printing ink and, optionally, solvent; b) mixing the product of a); c) adding hydrophobic silica and, optionally, solvent to the product of b) under mixing conditions; and d) adding thermal silica and, optionally, solvent to the product of c) under mixing conditions. The mixing can be carried out using a disperser blade. In an embodiment, the mixing conditions are 1800 RPM for 5 minutes. In an embodiment, the adding in d) is carried out by adding two portions of thermal silica while using solvent for viscosity adjustments.

[0046] In an aspect, the present disclosure provides methods of using the coating compositions. For example, the coating compositions are used to form a layer on a glass slide (e.g., a glass microscope slide).

[0047] In an embodiment, a method for forming a layer on a glass slide (e.g., a glass microscope slide) comprises: a) deposition of a layer of a coating composition on at least a portion of at least one surface of a glass slide; and b) heating the glass slide from a) such that a thermally-cured layer of coating composition is forme<

at least one surface of the glass slide. In an embodiment, the method further comprises deposition (e.g., printing using UV- or thermally-curable inks) of information on the thermally-cured layer of coating composition. In an embodiment, the glass slide is contacted with a surfactant after deposition of the layer of coating composition.

[0048] The layer of coating composition can be deposited on at least a portion of at least one surface of a glass slide. Suitable methods are known in the art. For example, the layer of coating composition is deposited by screen-printing methods, spray coating methods, dip coating methods, brushing, or similar methods. For example, the thickness of the as deposited layer of screen printing composition is 0.0001 inch to 0.001 inch, including all values to 0.0001 inch and ranges therebetween. In an embodiment, the thickness of the as deposited layer of screen printing composition is 0.0005 inch ± 0.0002 inch. In an

embodiment, the layer is deposited by methods such as, for example, screen-printing.

[0049] The layer of coating composition deposited on at least a portion of at least one surface of the glass slide can be cured by heating. For example, the curing is carried out in an oven at a temperature of 120°C to 215°C, including all integer °C values and ranges therebetween, for 5 minutes to 120 minutes, including all integer minute values and ranges therebetween. The dimensions of the thermally-cured layer of coating composition are substantially similar to those of the as deposited layer of coating composition.

[0050] Information may be deposited on the thermally-cured layer of coating composition. The information may be data. This information can be in the form of

alphanumeric characters, a barcode (e.g., linear, matrix, or other two-dimensional barcode), graphics (e.g., a logo or symbol), or other text. Some or all of the information may include patient and/or sample information. Some or all of the information may specifically identify a particular glass slide and/or sample. The identifying information may be used to, for example, archive samples, track samples, determine what testing or processes have been performed on a sample, or check in/check out samples. For example, the information is deposited on the thermally-cured layer of coating composition by ink-jet or thermal printing (e.g., using water or solvent based inks). In another example, the information is deposited on the thermally- cured layer of coating composition using a solvent-resistant pen used in histology labs (e.g., a Histopen).

[0051] A variety of glass slides can be used. The glass slides may be glass slides used in histology labs (e.g., a glass microscope slide). Examples of glass slides include Snowcoat® slides available from Leica, Xtra® slides available from Leica, and Superfrost™ available from Fisherbrand. The slides can have a variety of sizes.

length of 75 mm ± 0.5mm, a width of 25 mm ± 0.5mm, and a thickness of 0.04" +0.0037- 0.005". In an embodiment, the combined total of glass thickness and thermally-cured layer of screen printing composition thickness does not exceed 1.2 mm. The glass slides may be suitable for cellular (e.g., cytology) or molecular samples. The glass slides may be suitable for a histology sample (e.g., whole organisms or a part thereof, tissue samples, including blood and organ tissues, from a human or non-human animal, and cell(s), including isolated cell(s) and cell(s) in culture). In an embodiment, the glass slide is a microscope slide that conforms to ISO 8037-1 and/or -2. In an embodiment, the glass slide is a microscope slide made from green glass or white glass. The glass slide may itself be hydrophobic, hydrophilic, or wettable. The glass slide may have a coating to provide desired wettability and/or charge characteristics. Suitable glass slides are known in the art. Suitable glass slides are

commercially available.

[0052] In an aspect, the present disclosure provides articles comprising one or more of the coating compositions. For example, an article is a glass slide.

[0053] In an embodiment, an article is a glass slide comprising a thermally-cured layer of the coating composition disposed on at least a portion of at least one surface of the glass slide. Optionally, the glass slide has information deposited on the exterior surface on the layer of thermally-cured layer of the coating composition. Optionally, the glass slide further comprises a cellular sample (e.g., a cytology sample) or molecular sample. Optionally, the glass slide further comprises histology sample.

[0054] The glass slides can exhibit desirable characteristics such as adhesion, surface characteristics (e.g., ink spreading), and/or minimal dye retention of the thermally-cured layer of the coating composition. Also, the glass slides can exhibit desirable permanence (e.g., print image/visual appearance, wipe resistance, and/or barcode readability) of the information deposited on the exterior surface of the on the layer of thermally-cured layer of the coating composition.

[0055] The following examples are presented to illustrate the present disclosure. They are not intended to be limiting in any manner.

EXAMPLE 1

[0056] The following is an example of printing on a thermally-cured layer of a coating composition on a glass slide and evaluation of same. [0057] A structured methodology of testing a co;

ink technology that does not require the use of the vapor blast process) was carried out. The "writing" label surface for the composition was tested to assess print legibility, ink adhesion, "readability" and integrity of imprinted text and barcodes.

[0058] The testing consisted of four portions:

1. Human Readability : tested visual quality of text print to the human eye.

2. Digital readability : tested barcode reading with a Stationary barcode scanner.

3. Ink and Paint Adhesion : tested the integrity of the digital and human characters printed on the slide label surface and the compositions' adhesion to glass before and after contact with common Histology reagents and wiping the label surface with thumb and Kimwipe with a single back and forth motion for ink removal and smearing.

4. Solution testing: Consisting of a soak test in hematoxylin and eosin stains, water,

alcohol, xylene, oxidizers, acids, and bases with or without heating the sample.

a. Adhesiveness: Tested the ability of the composition to adhere to the glass after chemical soaks and exposure to solutions.

b. Human and Digital Readability: Tested the ability of the slide to retain information that is both human and digital readable after soaks and exposure to solutions.

[0059] A design of experiment was used to evaluate various mixtures of silicon dioxide particles and secondary composition concentrations. All other components such as base ink (epoxy -based, thermally-curable, screen-printing ink), silane, and thinner type were held constant. The viscosity of the composition was adjusted to be between 5,500 cP and 7,500 cP.

[0060] Table of Paint Components:

H13 72 8 20 0

H14 90 10 0 0 0.5 2.5 1.5 8

H15 81 9 10 0 2 0 1.5 8

H16 72 8 20 0 3 7 1.5 8

H17 72 8 20 1 0 2.5 1.5 8

H18 72 8 20 0 0.5 7 1.5 8

H19 81 9 10 0 0 5 1.5 8

H20 81 9 10 6 0 0 1.5 8

H21 90 10 0 0 3 0 1.5 8

H22 90 10 0 20 0 2.5 1.5 8

H23 72 8 20 0 0.5 2.5 1.5 8

H24 72 8 20 0 0.5 0 1.5 8

H25 90 10 0 0 0 7 1.5 8

H26 90 10 0 0 0.5 7 1.5 8

H27 90 10 0 0 3 7 1.5 8

H28 72 8 20 0 0 7 1.5 8

H29 81 9 10 0 2 5 1.5 8

H30 72 8 20 1 0 7 1.5 8

H31 72 8 20 20 0 7 1.5 8

H32 90 10 0 20 0 7 1.5 8

H33 72 8 20 20 0 0 1.5 8

[0061] Prior to execution of composition blending, sheets of white glass washed without surfactant coating were prepared. Each experiment was carried out according to the diagram in Figure 19.

[0062] Performance testing was carried out according to the diagram in Figure 20.

[0063] Composition Blending. Composition Blending was carried out according to the following:

(Paint in this paragraph is the "epoxy-based, thermally-curable, screen-printing ink".)

[0064] Mixing was carried out as follows: 1. Add paint components together in a medium size

2. Lower disperser blade into paint. Set RPM for 300 and advance to 600 after 15 seconds. After another 15 seconds advance RPM to 1200. Disperse for 10 minutes, then let paint sit 5 minutes.

3. Add particle components of paint together in a medium sized container. If any of the particles contain crystalline Si0₂, soak in solvent components for 10 minutes before adding components to the paint.

4. Measure solvent components in separate table. Disregard this step if you have already mixed solvent with crystalline Si0₂.

5. Set RPM to 1500 and slowly add about half the particles into the paint. Disperse for 5 minutes. Add the solvent components into the paint and disperse for 2 minutes. Slowly add the remaining particles and disperse.

6. Measure the viscosity of the paint and record.

7. Add additional AD-2003 until a viscosity between 5,500 and 7,500 cP has been achieved. Record each time solvent is added.

[0065] Screen Printing/Curing. The process of Screen Printing was carried out directly following the composition blending. The oven settings and screen specifications are shown in the following:

Oven Settings

[0066] Testing. Slide Printing on the IPS. Two slide types were tested, Fisherbrand designed for use with Leica Microsystems IP S inkjet printer; and Leica Biosy stems Direct Apply test slides. Testing was performed with white colored print surface slides. 50 of each formulation/control slide were printed at one time. As they were printed label appearance was viewed for legibility and the barcode scanned under stati

of about 35 mm from the barcode reader.

[0067] Performance Testing. Testing was carried out according to the following table for each formulation or control slide.

[0068] Testing Criteria. Human Readable. Slides were rated from 1 to 5. See Fig

Slides receiving a score of 4 and 5 were deemed to pass, and a slide with a score of 3 and below were deemed to result in a failure. [0069] Digital Readable. Slides were given score

takes to scan. The following table describes the scores given based on the scan time.

[0070] Adhesion. A slide was considered adhered when all paint was observed to stay on the glass after being subjected to manufacturing processes and testing with reagents. The slides received a score of 5 if it passed and 0 if it failed.

[0071] Post-Test Digital Readable/Smear Scan/Post Test Smear Scan. Slides were re- tested and scanned after going through the various performance tests and smear test. These slides were then tested as described above with respect to Digital Readable testing. The slides only received a score of 5 if it passed and 0 if it failed.

[0072] Post-Test Human Readable. Slides were re-tested and scanned after going through the various performance tests. These slides were tested the same as described above with respect to Human Readable testing.

[0073] Dye-Pickup. Slides were scored by using visual standards designated for varying levels of dye-pickup. See Figure 6. A score of 4 and 5 are passing and scores 3 and below are failing.

[0074] Data. Composition data is left of the bold line and test responses are right of the bold line.

H3 90.00 10 0 1 0 0 1.5 8 4.8 3.^ -S. D D.U -S. ± 3.3 4-. D D.U 1.0

H4 90.00 10 0 1 0 2.5 1.5 7 5.0 1.0 1.0 5.0 1.0 1.0 5.0 3.5 5.0 1.8

H5 72.00 8 20 20 0 2.5 1.5 16 3.0 1.1 1.0 5.0 1.0 1.0 3.1 3.5 5.0 5.0

H6 90.00 10 0 1 0 7 1.5 15 4.5 5.0 5.0 5.0 5.0 5.0 4.1 2.5 5.0 5.0

H7 90.00 10 0 20 0 0 1.5 8 3.0 1.0 1.0 5.0 1.0 1.0 3.0 4.0 5.0 5.0

H8 90.00 10 0 0 0.5 0 1.5 3 3.3 1.1 1.0 5.0 1.1 1.0 3.1 4.5 5.0 5.0

H9 90.00 10 0 0 3 2.5 1.5 18 5.0 5.0 5.0 5.0 5.0 5.0 5.0 3.5 5.0 5.0

H10 72.00 8 20 0 3 2.5 1.5 23 5.0 5.0 5.0 5.0 5.0 5.0 5.0 3.5 5.0 5.0

Hll 81.00 9 10 6 0 5 1.5 13 5.0 4.7 5.0 5.0 4.8 4.9 5.0 3.0 5.0 5.0

H12 72.00 8 20 1 0 0 1.5 3 5.0 1.3 1.0 5.0 1.2 1.1 5.0 4.5 5.0 5.0

H13 72.00 8 20 0 0 2.5 1.5 9 5.0 1.0 1.0 5.0 1.0 1.0 5.0 4.0 5.0 5.0

H14 90.00 10 0 0 0.5 2.5 1.5 7 5.0 1.1 5.0 5.0 1.1 1.1 5.0 3.0 5.0 5.0

H15 81.00 9 10 0 2 0 1.5 9 5.0 1.0 1.0 5.0 1.0 1.0 5.0 3.7 5.0 3.4

H16 72.00 8 20 0 3 7 1.5 34 5.0 5.0 5.0 4.8 5.0 5.0 5.0 2.5 5.0 5.0

H17 72.00 8 20 1 0 2.5 1.5 7 4.0 1.0 1.0 5.0 1.0 1.0 4.0 4.0 5.0 5.0

H18 72.00 8 20 0 0.5 7 1.5 19 4.0 5.0 5.0 5.0 5.0 5.0 4.0 2.5 5.0 5.0

H19 81.00 9 10 0 0 5 1.5 10 4.0 2.9 2.6 5.0 3.1 2.8 4.0 3.5 5.0 5.0

H20 81.00 9 10 6 0 0 1.5 8 4.0 1.0 1.0 5.0 1.0 1.0 4.0 4.4 5.0 1.0

H21 90.00 10 0 0 3 0 1.5 13 4.4 4.1 4.9 5.0 3.7 3.7 4.6 3.0 5.0 4.2

H22 90.00 10 0 20 0 2.5 1.5 12 4.0 1.0 1.0 5.0 1.1 1.1 4.0 3.5 5.0 5.0

H23 72.00 8 20 0 0.5 2.5 1.5 10 4.0 1.0 1.0 5.0 1.0 1.0 5.0 3.5 5.0 1.0

H24 72.00 8 20 0 0.5 0 1.5 3 3.8 1.2 1.0 5.0 1.1 1.2 3.9 4.0 5.0 5.0

H25 90.00 10 0 0 0 7 1.5 14 3.5 5.0 5.0 5.0 5.0 5.0 3.6 2.5 5.0 5.0

H26 90.00 10 0 0 0.5 7 1.5 18 4.0 5.0 5.0 5.0 5.0 5.0 4.2 2.5 5.0 5.0

H27 90.00 10 0 0 3 7 1.5 30 5.0 5.0 5.0 1.1 5.0 5.0 5.0 2.0 5.0 5.0

H28 72.00 8 20 0 0 7 1.5 18 3.7 5.0 5.0 5.0 4.9 4.9 3.6 2.5 5.0 5.0

H29 81.00 9 10 0 2 5 1.5 19 4.4 4.9 1.0 5.0 4.9 4.9 4.3 2.5 5.0 5.0

H33 72.00 8 20 20 0 0 1.5 15 4.0 1.0 1.0 5.0 1.0 1.0 4.0 3.8 5.0 5.0

[0075] Testing Summary. Human Readable Results. Results are shown in Figure 7.

Based on the particles that were mixed in the paint, all slides had an acceptable rating for human readibility with most slides receiving either a 4 or 5. High levels of Cystalline silica did not have a positive impact on human readability. [0076] Digital Readable/Scan Rate. Results are s

Sylophobic and ACEMatt had a positive impact on the scan rate of the slides. Higher percentages of ACEMatt and Sylophobic showed faster scan rates for the slides.

[0077] Additionally prediction formulas based on results from this study show that increased levels of Sylophobic and ACEMatt maximize desirability for barcode scan rate. Results are shown in Figure 9. A score of 5 indicated that it is passing, a score of 1 indicated failing. This shows that as the percentage (x axis) of ACEMatt and Sylophobic increases, the score gets higher. The maximized desirability is 1.

[0078] Adhesion. Results are shown in Figure 10. Almost all slides showed ink that had a passing level of adhesion to the glass. As concentrations of both Sylophobic and

ACEMatt were increased, the ink adhesion was reduced (see Figure 16).

[0079] Post-Test Human Readable. Slides were re-tested and scanned after going through the various performance tests. These slides were tested the same as described for

Human Readable Testing described above.

[0080] Dye-Pickup. Results are shown in Figure 11.

[0081] Prediction Profiles for various properties of example slides of the instant disclosure were generated. These profiles are shown in Figure 12.

[0082] Images of slides H29, H9, H27, H14, and H23 are shown in Figures 14 - 18.

[0083] There was a trend of increased dye pickup as the concentration of Sylophobic and ACEMatt increased when added to the Enthone 60 and Enthone 10. The concentration of crystalline silicon dioxide did not seem to have a clear trend with regards to dye pickup.

[0084] Addition of particles can have benefits for a screen printing ink. In this case,

Enthone 60 part A and B were used and in some formulations mixed with Enthone 10.

Slyophobic and ACEMatt combined showed good barcode readability. However, the mixture of the two in high concentrations may give issues with screen printing ink adhesion. The human readability of the alphanumeric letters generally passed regardless of which particles were added.

EXAMPLE 2

[0085] The following is an example of a coating composition, a method of making the composition, and use of the composition.

[0086] The coating of this example is a "Direct Apply" ink technology that does not require the use of the vapor blast process. A coating composition having the following composition was prepared:

The % values are % by weight values based on the weight of epoxy -based, thermally-curable screen-printing ink.

[0087] The epoxy -based, thermally-curable screen-printing ink was 4166 White manufactured by Markem Imaje. The thermal silica was ACEMatt TS 100 manufactured by Evonik. The hydrophobic silica was Sylophobic 200 manufactured by Fuji. The thinner was XO Thinner manufactured by Markem Imaje. In this example, 300.46 g of 4166 White, 8.99 g of ACEMatt TS 100, and 7.48 g of Sylophobic 200 were added to 95 mL of XO Thinner.

[0088] The 4166 White and 25 mL of XO Thinner were added in a container and stirred for 1 minute. The disperser blade was lowered into the screen-printing ink and the mixture was dispersed for 8 minutes at 1800 RPM. Sylophobic 200 and 40 mL of XO

Thinner were slowly added to the screen-printing ink while dispersing at 1800 RPM for 5 minutes. ACEMatt TS 100 and 20 mL of XO Thinner were slowly added to the screen- printing ink while dispersing at 1800 RPM for 5 minutes. ACEMatt TS 100 and 25 mL of XO Thinner were slowly added to the screen-printing ink while dispersing at 1800 RPM for 5 minutes. Viscosity was checked between each addition. XO Thinner was then added until the viscosity was 7,500 cP +/- 1000 cP. The tested viscosity for the screen printed ink was 6750.

[0089] To screen print, white glass was placed tin side up within the screen-printing press. The screen was lowered on top of the glass and the screen-printing ink was poured onto the screen. The squeegee was placed behind the screen-printing ink and pulled toward the end of the screen. It was noted that no major defects occurred and the screen-printing process was repeated until five printed sheets were produced.

[0090] The glass sheets were thermally-cured at approximately 330 F for seven minutes. The cured sheets were scored to 25 mm by 75 mm to form microscope slides. These microscope slides were inkjet printed in a Leica IP S printer to apply identifying information (see Figure 13). Each microscope slide passed testing for printing defects, barcode scanning, ink adhesion, and dye pickup. When compared to a benchmark slide (Thermo Fisher), the paint coloration of the microscope slides formed using the composition disclosed herein was whiter. Performance characteristics of the microscope slides using the composition disclosed herein matched the benchmark slide (see Figures 1 (PRIOR ART) and 2 (PRIOR ART)). [0091] While the disclosure has been particular^

to specific embodiments (some of which are preferred embodiments), it should be understood by those having skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as disclosed herein.

Claims

What is claimed is:

1 A coating composition comprising:

a) an epoxy-based thermally curable screen-printing ink;

b) a thermal silica; and

c) a hydrophobic silica.

2. The coating composition of claim 1, wherein the coating composition further comprises a solvent.

3. The coating composition of claim 1, wherein the coating composition further comprises a pigment.

4. The coating composition of claim 1, wherein the coating composition further comprises a si lane.

5. The coating composition of claim 4, wherein the silane is present at 1-5% by weight.

6. The coating composition of claim 1, wherein the epoxy-based thermally curable screen- printing ink is a two-component epoxy-based thermally curable screen-printing ink.

7. The coating composition of claim 6, wherein the two-component epoxy-based thermally curable screen-printing ink is Enthone 60 Part A and Enthone 60 Part B.

8. The coating composition of claim 7, wherein the ratio of Enthone 60 Part A to Enthone 60 Part B is 90: 10.

9. The coating composition of claim 1, wherein the thermal silica is ACEMATT^® TS.

10. The coating composition of claim 1, wherein the hydrophobic silica is Sylophobic 200.

11. The coating composition of claim 1, wherein the ratio of epoxy-based thermally curable screen-printing ink to thermal silica is 10:3.

12. The coating composition of claim 1, wherein the ratio of epoxy-based thermally curable screen-printing ink to hydrophobic silica is 10:3.

13. The coating composition of any one of the preceding claims, wherein the ratio of thermal silica to hydrophobic silica is 1 :0.75 to 1 :20.

14. The coating composition of claim 13, wherein the u

silica is 1 : 1.2.

15. A glass slide having a layer comprising a thermally-cured composition of claim 1 disposed on at least a portion of at least one surface of the glass slide.

16. The glass slide of claim 15, wherein the layer has at least one alpha numeric character, bar code, and/or graphic printed on the exterior surface of the layer.

17. The glass slide of claim 15 or claim 16, wherein the glass slide is a microscope slide.

18. The glass slide of claim 15, wherein the glass slide further comprises a cellular or molecular sample.

19. The glass slide of claim 15, wherein the glass slide further comprises a histology sample.