EP2748252A1

EP2748252A1 - Method for forming a carbon film or inorganic material film on a substrate

Info

Publication number: EP2748252A1
Application number: EP12826374.6A
Authority: EP
Inventors: Hsing-Hua Chang
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2011-08-25
Filing date: 2012-08-24
Publication date: 2014-07-02
Also published as: EP2748252A4; WO2013028985A1

Abstract

A method is disclosed for forming a carbon film or an inorganic material film on a substrate. A hydrophilic film-forming composition is provided, comprising a non-ionic surfactant component, an anchored vinyl pyrrolidone/vinyl acetate copolymer, a stabilizer component and a solvent, said non-ionic surfactant component being selected from alkoxylated alkyl diols. Also provided are a method for preparing the hydrophilic film-forming composition, a dried hydrophilic film prepared from the composition, and use thereof.

Description

METHOD FOR FORMING A CARBON FILM OR AN INORGANIC MATERIAL

FILM ON A SUBSTRATE

Technical Field

The present application relates to a hydrophilic film-forming comp osition, preparation metho d thereo f, a dried hydrophilic film made from the comp osition, and thereo f.

B ackground Art

Optically clear and hydrophilic articles are widely used in daily life . Examples of such optically clear and hydrophilic articles include protective eye shields (for example, goggles, face shields, surgery masks and helmets, etc. ), eyeglass lenses, decorative eyeglass frames, windows of vehicles, and windshields, among others . These articles will be more valuable if there are ways to counteract their tendency to mist up when in use. To this end, there is a particular need for a coating that can form a hydrophilic and anti-mist film. US 6,040,053A discloses a coating composition that imparts a coated substrate with the properties of anti-reflection and anti-mist. The coating composition comprises an inorganic metal oxide and a silane or siloxane oligomer, and is particularly useful for the manufacture of disposab le surgery masks and face shields .

S ome devices such as diagnostic testing devices (for example, bloo d glucose testing strips, urine testing strips, pregnancy testing devices etc .) are comprised of a substrate manufactured from one or more materials having the physical or chemical properties that facilitate fluid transport. However, they fail to achieve the desired effects . It is known in the art to apply a surfactant co ating onto a substrate to form a hydrophilic surface in order to enhance the fluid transport on the sub strate. US 7, 378 ,45 1 B2 discloses a hydrophilic surfactant composition having a stable hydrophilicity, which comprises a surfactant comp onent and a stabilizer component. The hydrophilic surfactant comp osition is coated onto a surface of a substrate by depo siting a solution of the surfactant onto at least a portion of the surface of the substrate, and drying the solution of the surfactant to form a dried coating layer on the surface o f the substrate. US 4, 824, 640 discloses transp arent reagent carrier layers in analytical agents for dry chemical detection of constituents of aqueous samp le solutions, wherein a layer comprises water solub le or water swellable components selected from the group consisting of po lyacrylamide, polyacrylic acid, cellulose ether, polyethyleneimine, polyvinyl alcohol, copolymer of vinyl alcohol and vinyl acetate, gelatin, agaros e, alginate and polyvinyl pyrro lidone, and sub stantially water insolub le film- forming components selected from the group consisting of polystyrene sulfonate, cellulo se ester, polyvinyl acetate, polyamide, polycarbonate, po lyether-carbonate, ionic polyurethane, non-ionic po lyurethane, mixtures thereof and copolymers thereof.

However, some surfactants are not suitable for use in devices subj ected to pro longed storage, and p articularly to high temp erature storage, and/or not suitable for use in the structures of articles of manufacture in which reagents, binders, dyes, pharmaceuticals and excipients or other contaminants are present, b ecause the hydrophilicity provided by the surfactant coating may disapp ear over time or due to high temperature .

Contamination is the necessary result of human operations or of contact o f the materials with the environments during lamination. Contaminants can be volatile or movable and can depo sit on the coated surfactant composition or come into contact with the surfactant composition. By way of example, pressure-sensitive or structural binders are generally known to comprise substantial amounts of monomers, catalysts, plasticizers , tackifiers and other components, which may move over time and deposit on the surfactant composition or come into contact with the surfactant composition to impart hydrophilicity thereto . A protective film can be used to avoid contamination. However, delamination may lead to the p eeling of the hydrophilic surfactant co ating layer.

Summary of the Invention

The present invention provides a hydrophilic film- forming composition comprising a non-ionic surfactant component, an anchored vinyl pyrrolidone/vinyl acetate copolymer, a stabilizer component and a solvent, said non-ionic surfactant component being selected from alkoxylated alkyl diols . The hydrophilic film- forming composition according to the present invention can form a coating layer on a substrate . The coating layer is heat-resistant, anti-mist and durable, can maintain its hydrophilicity, can facilitate fluid transp ort at ro om temperature or even at high temperature, and can provide anchored force for the co ated substrate .

In one aspect, the present invention provides a hydrophilic film- forming compo sition comprising, based on the total weight of the composition, a non-ionic surfactant comp onent selected fromalkoxylated alkyl dio ls in an amount of about 0.02 wt% to about 5 wt%; a stabilizer component in an amount of about 0.0 1 wt% to about 5 wt%; an anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 35 wt% to ab out 0.5 wt%; and a solvent in the remaining amount.

The hydrophilic film- forming composition according to the present invention comprises the non-ionic surfactant component in an amount of about 0.02 wt%, about 0.05 wt% or about 0.1 wt%. The hydrophilic film-forming composition according to the present invention comprises the non-ionic surfactant component in an amount of up to about 5 wt%, about 4 wt% or about 3 wt%. In one embodiment, the hydrophilic film-forming composition according to the present invention comprises the non-ionic surfactant component in an amount of ab out 0.02 wt% to about 5 wt%. In some other embodiments, the hydrophilic film-forming composition according to the present invention comprises the non-ionic surfactant component in an amount o f about 0.05 wt% to about 4 wt% or about 0.10 wt% to about 3 wt%. The non-ionic surfactant component is selected from alkoxylated alkyl diols, such as alkoxylated C₂_24 alkyl dio ls or alkoxylated C₂_i2 alkyl diols . As used herein, the term "alkoxylated" means that the surfactant has been reacted with alkylene oxide in such a way that one or more of the units of the alkylene oxide are covalently bonded to the surfactant. In a preferred embodiment, the non-ionic surfactant component is 2,5,8,1 l-tetramethyl-6-dodecyn-5,8-diol ethoxylate.

Typically, the hydrophilic film-forming composition according to the present invention comprises the stabilizer component in an amount o f about 0.0 1 wt%, ab out 0.05 wt% or about 0. 1 wt%. The hydrophilic film- forming composition according to the present invention comprises the stabilizer comp onent in an amount of up to about 5 wt%, about 4 wt% or about 3 wt%. For example, the hydrophilic film-forming composition according to the present invention comprises the stabilizer comp onent in an amount of about 0.01 wt% to about 5 wt% or about 0.05 wt% to about 45 wt% or ab out 0.10 wt% to about 3 wt%. The stabilizer component of the hydrophilic film- forming composition according to the present invention can include one or more compounds that can pro long the time period during which the surfactant imparts hydrophilicity to the sub strate coated with the hydrophilic film-forming compo sition. The stabilizer component can be selected such that it virtually will not counteract the hydrophilicity of the surfactant, and can practically be selected such that it contributes to the hydrophilicity of the hydrophilic film-forming compo sition. In mo st embodiments, the stabilizer component of the hydrophilic film- forming comp osition can have a melting point of higher than about 23 °C . In particular embo diments, the stabilizer comp onent can have a melting point of higher than about 35 °C or at least about 45 ° C. In some embo diments, the stabilizer component can contribute to the hydrophilicity of the hydrophilic film-forming composition. In some embodiments, the stabilizer comp onent includes an alkyl, aralkyl or alkaryl sulfonate, sulfate, pho sphonate or phosphate surfactant having ab out 8 to about 24 carbon atoms, which will not prevent the hydrophilic film- forming composition from forming a hydrophilic surface and which has a melting point of higher than about 25 °C . In some embodiments, the stabilizer has an alkyl, aralkyl or alkaryl chain of about 1 0 to about 1 8 carbon atoms . In other embodiments, the stabilizer has an alkyl, aralkyl or alkaryl chain of about 1 0 to about 14 carbon atoms, such as 12 carb on atoms . In some examples , in the absence of any solvent, the stabilizer comp onent can have a melting point of higher than ab out 45 ° C. The alkyl group can be linear, branched, cyclic or any combination thereof. In particular embodiments, sodium dodecyl b enzenesulfonate is used as the stabilizer. The hydrophilic film- forming composition according to the present invention comprises the anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 0.5 wt% or about 1 wt%. The hydrophilic film-forming composition according to the present invention comprises the anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of up to 35 wt%, 25 wt% or 20 wt%. In some embodiments, the hydrophilic film-forming composition according to the present invention comprises the anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 35 wt% to about 0.5 wt%. In some other embodiments, the hydrophilic film-forming composition according to the present invention comprises the anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 25 wt% to about 1 wt% or about 20 wt% to about 1 wt%.

The anchored vinyl pyrrolidone/vinyl acetate copolymer has a molecular weight (MW) of about 13,000 daltons to about 57,000 daltons or about 15,000 daltons to about 56,000 daltons. The anchored vinyl pyrrolidone/vinyl acetate copolymer comprises repeating units represented by the following formula:

wherein the vinyl acetate units and the vinyl pyrrolidone units are in a weight ratio (n/m) of 70/30 to 30/70, preferably 70/30 to 50/50. Any solvent useful for preparing the hydrophilic film-forming composition can be used in the present invention. Such solvent can be an aqueous or organic solvent, such as a hydroalcoholic solvent. Suitable solvents include water and organic solvents, such as, but not limited to ketones, ethers and alcohols. Suitable alcohols include methanol, ethanol, 1-propanol, 2-propanol, isopropanol, n-butanol and isobutanol, etc. In particular embodiments, suitable solvents can include hydroalcoholic solvents, such as a 70/30 mixture of isopropanol and water.

According to one embodiment of the present invention, the hydrophilic film-forming composition comprises, based on the total weight of the composition, the non-ionic surfactant component in an amount of about 0.05 wt% to about 4 wt%, the stabilizer component in an amount of about 0.05 wt% to about 4 wt%, the anchored v i n y 1 py rr o li do ne /vinyl acetate copolymer in an amount of about 25 wt% to about 1 wt%, and the solvent in the remaining amount. According to another embodiment of the present invention, the hydrophilic film-forming composition comprises, based on the total weight of the composition, the non-ionic surfactant component in an amount of about 0.10 wt% to about 3 wt%, the stabilizer component in an amount of about 0.10 wt% to about 3 wt%, the anchored v i n y 1 py rr o li do ne /vinyl acetate copolymer in an amount of about 20 wt% to about 1 wt%, and the solvent in the remaining amount. The hydrophilic film-forming composition according to the present invention can be deposited onto any surface where the property of the hydrophilic film-forming compo sition is desired. For example, the hydrophilic film- forming composition according to the present invention can be coated onto a surface of a substrate and then dried to form a hydrophilic film on the substrate, thus obtaining a dried hydrophilic film. The hydrophilic film- forming composition according to the present invention can be coated onto a surface of an article and then dried to form an article co ated with a hydrophilic layer. The aqueous materials can be evenly dispersed in the hydrophilic coating layer of the article .

The article can be any obj ect article for which aqueous disp ersivity is desired, such as a mirror, a blinder, an eyeglass lens, a decorative glass frame or a window.

The hydrophilic film- forming compo sition according to the present invention can also be deposited onto at least a portion of a surface of a device which is designed to regulate the movement of a liquid sample . Such device includes, but not limited to, a device for performing the diagnosis or testing of a liquid sample. Such device may also need to have a hydrophilic surface in order to facilitate the transp ort of at least a portion of the liquid samp le from a p osition to another po sition of the device . However, a surface of a device on which or through which a samp le normally traverses or passes may not have a sufficient hydrophilicity to provide suitable efficiency. In such a case, the hydrophilic film- forming composition according to the present invention can be deposited onto at least a portion of the fluid transport surface in order to facilitate the fluid transport of a liquid sample which is sufficient to provide suitable efficiency. The hydrophilic film- forming composition can also be deposited into different p atterns under the control o f which a fluid flows in particular ways, such as continuous, incontinuous or repeated patterns .

The hydrophilic film- forming composition in solution form as described above can b e deposited on at least a portion of a surface where the hydrophilic film- forming compo sition is needed. The hydrophilic film-forming comp osition can be depo sited using any suitable methods known in the art, which include but not limited to spray coating, roll coating, gravure coating, wire-bar coating, dip coating or immersion coating, extrusion (molded) coating, air knife coating, glide coating, blade coating, electrostatic coating, ink-j et printing or flow coating.

On the other hand, the present invention relates to a method for prep aring the hydrophilic film- forming composition described above, comprising forming an aqueous phase containing the non-ionic surfactant component, the stabilizer component and water, forming an organic phase containing the anchored vinyl pyrrolidone/vinyl acetate copolymer and the so lvent, and mixing the aqueous phase with the organic phase . Typically, such preparation method is conducted at room temperature, preferab ly, such preparation method can conducted by heating at a temperature in the range of from ab out ro om temperature to b elow the boiling temp erature of the solvent. For example, when isopropanol is used as the solvent, the preparation method can be conducted in the range of from room temp erature to about 80° C.

In yet another aspect, the present invention relates to a dried hydrophilic film comprising :

a sub strate,

a hydrophilic layer formed on the substrate, and, if desired,

a protective layer applied onto the hydrophilic layer.

The hydrophilic layer of the dried hydrophilic film can be formed by co ating the hydrophilic film- forming composition according to the present invention described above to a surface of the substrate, and then drying the surface of the substrate to provide a hydrophilic layer comprising the non-ionic surfactant comp onent, the stabilizer component and the anchored vinyl pyrrolidone/vinyl acetate cop olymer. If desired, a protective layer can be applied onto the hydrophilic layer.

The substrate can be comprised of any material that can at least partly be coated under the physical and structural conditions to be applied. Suitable substrates include but not limited to glass, metal, as well as po lymeric sub strates of various structures and comp ositions, including flat plates, screen films, non-woven fabrics, test tubes, capillaries, planar films or structural films, and film/film or film/non-woven fabric laminates . In most emb odiments, such substrates are non-porous . The most preferred substrates are films that may or may not comprise three-dimensional structures such as channels, pyramids, p ouches and analogues . Suitable sub strates polymer comp osition and it' s morphology that can be coated with the hydrophilic film- forming composition according to the present invention are for example described in U.S. Pat. No. 5,514,120 issued on May 7, 1996; U.S. Pat. No. 5,728,446 issued on March 17, 1998; U.S. Pat. No. 6,290,685 issued on September 18, 2001 ; U.S. Pat. No. 6,375,871 issued on April 23, 2002; U.S. Pat No. 6,420, 622 issued on July 16, 2002; and U.S. Ser. No. 09/612,418 filed on July 1, 2000. The morphological substrate described in these prior art documents are appropriate and are independent of the materials used to comprise the substrates . The polymeric substrates can be formed by any suitable apparatus, including extruding, inj ection molding, film blowing, film pressing, casting etc.

The hydrophilic film- forming compo sition according to the present invention can be dried by any suitable apparatus . As used herein, the terms "dried" or "drying" refers to methods for removing a solvent (which may or may not contain water) in which the hydrophilic film- forming composition is dissolved. For example, the hydrophilic film-forming composition can be dried by heating the coated substrate in a hot air recycling oven, an infrared oven or a radio frequency oven. In addition, the hydrophilic film-forming composition can be dried, without heating, by simp le evaporation or by evaporation by forced air drying. The temperature and duration of heating can partly be determined by the physical or chemical compo sition of the substrates . That is, some substrates can endure a relatively high temperature without changing the p articular physical or chemical properties desired for the substrates after performing the coating methods . Other substrates can have relief structures or other microstructures, and require relatively high or relative low thermo dynamics in order to evenly dry the coating layer.

The dried hydrophilic film can have any thickness desired for a particular purpose. For example, the dried hydrophilic film can have a thickness of about 50 nm to about 9,250 nm, preferably a thick of about 1 00 nm to about 5 ,000 nm. The dried hydrophilic film prepared from the hydrophilic film-forming composition according to the present invention can form a coating layer on a substrate . The coating layer is heat-resistant, anti-mist and durable, can maintain its hydrophilicity, can facilitate fluid transport at ro om temperature or even at high temperature, and can provide anchored force for the coated sub strate. The dried hydrophilic film can b e used in different hydrophilic applications, such as protective eye shields (for example, goggles, face shields, surgery masks and helmets, etc . ), eyeglass lenses, decorative eyeglass frames, windows of vehicles, and windshields, among others . In addition, the dried hydrophilic film can be used as a coating layer in medical diagno stic devices which is in contact with or transports body fluids, such as human bloo d, human blood comp onents, urine, mucus, etc .

The following examples further illustrate the present invention. These examples are not intended to limit the scop e of the present invention, instead they describe in more detail the aspects and embodiments of the present invention mentioned above. In the examples, p arts, ratio s and percentages are by weight, unless otherwise specified. Brief Description of the Drawings

None.

Detailed Description o f the Invention

In the following examples, the representative hydrophilic film-forming compo sitions according to the present invention are prepared using the starting materials and weight percentages listed in Table 1 :

Starting materials :

Dyno l 604 is 2, 5 , 8 , 1 1 -tetramethyl-6-do decyn-5 , 8 -diol ethoxylate, commercially availab le from Air Products and Chemicals, Inc.

Sip onate D S -IO is sodium dodecyl benzenesulfonate, commercially available from Rhodia Inc.

PVP-VA 1335 is 30% v i n y l p y r r o 1 i d o n e /70%vinyl acetate copolymer, commercially available from International Specialty Products company, with a solid percentage of from 48% to 52%. PVP-VA 1735 is 70% vinyl pyrro li d one/30% having a high glass transition temperature (Tg), commercially available from

International Specialty Products company, with a solid percentage of from 48% to 52%. PVP-VA S630 is a 97% dry powder having 60% vinyl pyrrolidone /40%vinyl acetate copolymer, commercially available from International Specialty Products company. Protective tape 1T01L is a polyester acrylate tape having a low tackiness and a ATS of 10-30 gf/in, commercially available from 3M. Protective tape 2T01S is a polyester acrylate tape having a low tackiness and a ATS of 4 gf/in, commercially available from 3M.

Example 1

In a 250 mL vessel, 0.39 g of Siponate DS-10 was diss olved into 83.64 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 0.81 g of Dynol 604 and stirring was continued for 15 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 1 5 g of PVP/VA 1335 was dissolved into 200.16 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming compo sition.

Example 2

In a 250 mL vessel, 0.39 g of Siponate DS-10 was diss olved into 77.64 mL of deionized water under stirring to form an aqueous solutionJnto the aqueous solution was added 0.81 g of Dynol 604 and stirring was continued for 15 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 30 g of PVP/VA 1335 was dissolved into 191.16 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming compo sition.

Example 3

In a 250 mL vessel, 0.78 g of Siponate DS-10 was diss olved into 89.64 mL of deionized water under stirring to form an aqueous solution. Into the aqueous so lution was added 3.24 g of Dynol604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 3.0 g of PVP/VA 1 335 was dissolved into 203.34 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming comp osition. Example 4

In a 250 mL vessel, 13.5 g of Siponate DS-10 was dissolved into 90 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 13.5 g of Dynol604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 180 g of PVP/VA 1 335 was disso lved into 3 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film- forming comp osition.

Example 5

In a 250 mL vessel, 6.0 g of Siponate DS- 10 was dissolved into 90 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 6.0 g of Dynol 604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 90 g of PVP/VA 1 335 was dis solved into 1 08 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film- forming comp osition.

Example 6

In a 250 mL vessel, 0.78 g of Siponate D S- 1 0 was dissolved into 85.44 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 1 .62 g of Dynol 604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 1 5 g of PVP/VA 1 335 was dissolved into 1 97. 1 6 g of isopropanol under stirring to form an organic so lution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming comp osition.

Example 7

In a 250 mL vessel, 0.78 g of Siponate D S- 1 0 was dissolved into 86.64 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 1 .62 g of Dynol 604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vessel, 1.5 g of PVP/VAI335 and 6.0 g of PVP/VA 1735 were dissolved into 203.46 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic s olution under stirring to form a hydrophilic film-forming composition.

Example 8

In a 250 mL vessel, 0.78 g of Siponate D S- 1 0 was dissolved into 83.76 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 1 .62 g of Dynol 604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a separate 500 mL vess el, 15 g of PVP/VAS630 was dissolved into 198.84 g of isopropanol under stirring to form an organic solution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming composition.

Example 9

In a 250 mL vessel, 0. 1 5 g of Siponate D S - 1 0 was dissolved into 90 mL of deionized water under stirring to form an aqueous solution. Into the aqueous solution was added 0. 1 5 g of Dynol 604 and stirring was continued for 1 5 minutes until a homogeneous aqueous solution was obtained. In a sep arate 500 mL ves sel, 7.5 g of PVP/VA 1 335 was dissolved into 202.2 g of isopropanol under stirring to form an organic so lution. The aqueous solution was incorporated into the organic solution under stirring to form a hydrophilic film-forming comp osition.

Tests : Film coating :

By means of spraying coating method, the hydrophilic film-forming compo sition described above was applied, using the wire bar or gravure roll of a pilot co ater, to a surface of a polyester substrate to form a coating layer. In this example, about 5 mL of the hydrophilic film-forming compo sition describ ed above was applied to the polyester substrate of 20 cm in width and 70 cm in length. When using the wire bar to apply, Webster, N.Y., RDS 9 wire bar was used to apply the hydrophilic film-forming composition described above to form a wet film having a thickness of 20.57 μ.

The following tests were conducted:

A. drop diffusion (wetting) test:

This test was to determine the degree of diffusion or wetting of the hydrophilic film-forming composition on test films . S amples of 6 inches in width and 6 inches in length were cut from a product roll and used as test films . All the test films were placed on a flat surface, and 3 drop s of the dye solution was added to the individual test films such that the surfaces of the test films were in contact with the dye solution. The drops were allowed to diffuse to their greatest extent, and then the drops on the test films were allowed to dry in air for 1 0 minutes . The diameters of the drops were determined by placing the films on a paper having predetermined circumferences of various diameters . The diameters of the drops (mm) were recorded. Drops of irregular shapes were designated as "NC" (non-circular) .

B . anchored force test:

This test was to determine the anchoring prop erty o f the hydrophilic layer when stored at room temp erature and at high temp erature. The hydrophilic layers of the polyester films were covered with protective layers and stored at room temperature for 30 minutes and at 1 00° C (HT) for 30 minutes respectively, followed by manually removing the protective layers. The hydrophilic layers were subj ected to the drop diffusion test to determine the persistence of hydrophilicity. The protective layers used in this test were polyester tape "protective tape 1T01L" available from 3 M having low tack acrylate adhesive, and polyester tape "protective tape 2T01 SJ" available from 3 M having low tack pressure-sensitive polysiloxane adhesive.

The results of the drop diffusion (wetting) test and anchored force test of the hydrophilic film-forming composition according to the present invention and the dried hydrophilic films prepared therefrom and the comparative examp le were shown in Tab le 2.

In general, the diameter of the drop on the film without a hydrophilic co ating layer was about 2.5 mm. According to the results o f the above drop diffusion test, the hydrophilicity of the films coated with the hydrophilic film-forming composition according to the present invention dramatically increased. Comparing the results of the drop diffusion test and the anchored force test, it was shown that the hydrophilic persisted even after the protective layers had been removed. In addition, the hydrophilicity of the films coated with the hydrophilic film-forming composition according to the present invention remained stable even after storage at high temperature. Since the hydrophilic film- forming composition according to the present invention has enduring hydrophilicity for liquid diffusivity, those skilled in the art will appreciate that it can also achieve anti-mist property.

Claims

1. A hydrophilic film-forming composition, comprising, based on the total weight of the comp osition,

a non-ionic surfactant comp onent selected fromalkoxylated alkyl diols in an amount of about 0.02 wt% to about 5 wt%;

a stabilizer component in an amount o f about 0.0 1 wt% to about 5 wt%;

an anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 35 wt% to about 0.5 wt%; and

a solvent in the remaining amount.

2. The hydrophilic film- forming composition according to claim 1 , wherein said non-ionic surfactant component is selected from alkoxylated C2-24 alkyl diols .

3. The hydrophilic film- forming composition according to claim 1 , wherein said non-ionic surfactant component is selected from alkoxylated C2- 12 alkyl diols .

4. The hydrophilic film- forming composition according to claim 3 , wherein said non-ionic surfactant component is 2,5,8,1 l-tetramethyl-6-dodecyn-5,8-diol ethoxylate.

5. The hydrophilic film- forming composition according to claim 1 , wherein said stabilizer is selected from anionic stabilizers selected from the group consisting of C 8 -24 alkyl sulfonates, C 8 -24 aralkyl sulfonates and C 8 -24 alkaryl sulfonates .

6. The hydrophilic film- forming composition according to claim 5 , wherein said stabilizer is sodium do decyl benzenesulfonate.

7. The hydrophilic film- forming composition according to claim 1 , wherein said anchored vinyl pyrrolidone/vinyl acetate copolymer has a mo lecular weight (MW) of from about 1 3 , 000 daltons to about 57,000 daltons.

8. The hydrophilic film- forming composition according to claim 1 , wherein said anchored vinyl pyrrolidone/vinyl acetate copolymer has a mo lecular weight (MW) of from about 1 5 , 000 daltons to about 56,000 daltons.

9. The hydrophilic film-forming composition according to claim 1 , comprising, based on the total weight of the compo sition, the non-ionic surfactant component in an amount of about 0.05 wt% to about 4 wt%, the stabilizer component in an amount of about

0.05 wt% to about 4 wt%; the anchored vinyl pyrrolidone/vinyl acetate copolymer in an amount of about 25 wt% to ab out 1 wt% ; and the solvent in the remaining amount.

1 0. The hydrophilic film-forming composition according to claim 9, comprising, based on the total weight of the compo sition, the non-ionic surfactant component in an amount of about 0.10 wt% to about 3 wt%, the stabilizer comp onent in an amount of about 0.10 wt% to about 3 wt%; the anchored vinyl pyrrolidone/vinyl acetate copo lymer in an amount of about 20 wt% to ab out 1 wt% ; and the solvent in the remaining amount.

1 1 . a dried hydrophilic film, comprising :

a sub strate,

a hydrophilic layer formed on the substrate, and, if desired,

a protective layer applied onto the hydrophilic layer,

wherein the hydrophilic layer is formed by coating the hydrophilic film- forming compo sition according to any one of claims 1 to 1 0 to the substrate and then drying the coated substrate .

12. A method for preparing the hydrophilic film-forming composition according to any one of claims 1 to 1 0 , comprising forming an aqueous phase containing the non-ionic surfactant component, the stabilizer component and water, forming an organic phase containing the anchored vinyl pyrrolidone/vinyl acetate copolymer and the so lvent, and mixing the aqueous phase with the organic phase .

1 3. A sample for testing body fluids, characterized in that it comprises the dried hydrophilic film as defined in claim 1 1 .

14. An article, characterized in that at least a surface thereo f is coated with the hydrophilic film- forming composition according to any one of claims 1 to 1 0.

1 5. The article according to claim 14, which is selected from a mirror, a blinder, an eyeglass lens, a decorative glass frame or a window.