JP2010242092A - Polymeric film having coating layer of phosphonic acid group containing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymeric film that alleviates or essentially overcomes at least one of the problems in a printing plate. <P>SOLUTION: The polymeric film which is substantially gelatin free has a polymeric film substrate and a coating layer containing a polymer having at least one or more repeating units having at least one or more pendant (-POXY) groups, wherein X and Y, which may be the same or different, are OH or OM wherein M is a cation. The polymeric film is suitable for use as a constituent material of the printing plate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention has a polymerized film, in particular a coating layer substantially free of gelatin and suitable for use as a constituent of a printing plate.

  This application is a divisional application based on Japanese Patent Application No. 2000-525265.

  Printing plates, particularly lithographic printing plates, generally comprise a substrate, a hydrophilic coating layer and a photopolymerizable photosensitive layer. Upon exposure of the appropriate photoelectric image to the image, the photopolymerizable layer cures and the uncured portion of the layer can be removed by washing with a solvent. As a result, a hydrophobic polymer image can be formed on the hydrophilic substrate and used as a lithographic printing plate. Another method uses a laser imaging method to apply hydrophobic toner to the hydrophilic coating layer.

GB-A-838708 specification EP-A-1879 specification EP-A-184458 specification US-A-4008203 Specification

  The surface nature of the hydrophilic coating layer can be very important in determining the quality of the final printed image. For example, in some previous similar techniques, hydrophilic coating layers have poor coating quality and poor adhesion to the underlying substrate and / or the overlying photopolymerizable layer or toner. In addition, the coating layer may result in a surface microstructure that can lead to inadequate hydrophilic and / or improper removal of uncured photopolymerized portions and the repeated formation of relatively poor quality printed images. unknown. In laser toner based processes, the hydrophilic coating layer may require antistatic properties in order to control or prevent toner scatter that reduces the final image quality.

  In some processes used to make printing plates, relatively high temperatures are used and can affect the curl and flatness of any polymerized film present in the printing plate.

  A hydrophilic coating layer such as gelatin is conventionally applied to the polymerized film after production of the finished film, ie “off-line”, resulting in the number of process steps required to produce the coating film. To increase. To simplify and improve the efficiency of the manufacturing process, it is necessary to be able to apply the coating layer during the film manufacturing process, ie “in-line”, without using gelatin.

  We have invented a polymerized film that alleviates or essentially overcomes at least one of the aforementioned problems.

  Accordingly, the present invention provides a polymerized film that is substantially free of gelatin and includes a polymerized film substrate having a coating layer (containing a polymer having at least one repeating unit) on at least one surface thereof. Wherein the repeat unit has at least one or more pendant (-POXY) groups, X and Y, which are the same or different, are OH or OM and M is a cation.

  The present invention further provides a method for producing a polymerized film, the method comprising a step of forming a polymerized film substrate, and a step of applying a coating composition to at least one surface of the substrate, wherein the coating composition Includes polymers having at least one repeating unit having at least one pendant (-POXY) group, wherein X and Y, which are the same or different, are OH or OM and M is a cation .

  The present invention also provides a printing plate comprising a polymerized film substrate having a coating layer (containing a polymer having at least one repeating unit) on at least one surface thereof, Here, the repeating unit has at least one pendant (—POXY) group, and X and Y which are the same or different are OH or OM, and M is a cation.

  The polymerized film according to the invention can be melted as a coating for mirrors, in particular automotive mirrors, and building surface coverings. The polymerized film substrate is a film that can exist independently without a base fabric.

  A substrate coated with a coating layer composition to obtain a polymerized film according to the present invention may be formed from any suitable film-forming polymeric material. Thermoplastic materials are preferred, including homopolymers or copolymers of 1-olefins such as ethylene, propylene and 1-butene, polyamides, polycarbonates, polyesters, especially one or more dicarboxylic acids or their lower alkyls (up to 6 carbon atoms) ) Diesters such as terephthalic acid, isophthalic acid, phthalic acid, 2,5-, 2,6- or 2,7-naphthalenedicarboxylic acid, succinic acid, sebacic acid, adipic acid, azelaic acid, 4,4'-diphenyl A dicarboxylic acid, hexahydro-terephthalic acid or 1,2-bis-p-carboxyphenoxyethane (optionally with a monocarboxylic acid such as pivalic acid) and one or more glycols, in particular aliphatic glycols (eg ethylene glycol, 1, 3-propanediol, 1,4-buta Diol, neopentyl glycol and 1,4-cyclohexane - synthetic linear polyester which may be obtained by condensation of di-methanol) is more preferable. Polyethylene terephthalate and / or polyethylene naphthalate films are preferred. Polyethylene terephthalate film is particularly preferred, mainly stretched sequentially in two directions perpendicular to each other (typically at a temperature in the range of 70 to 125 ° C., preferably at a temperature in the range of typically 150 to 250 ° C. The film is biaxially oriented by heat setting), and is described, for example, in Patent Document 1 [GB-A-838708]. Another preferred film comprises terephthalic acid and a copolymer of isophthalic acid and ethylene glycol. The substrate may comprise a polyaryl ether or a thio analog thereof, in particular a polyaryl ether ketone, polyaryl ether sulfone, polyaryl ether ether ketone, polyaryl ether ether sulfone, or a copolymer or thio analog thereof. Examples of these polymers are disclosed in Patent Document 2 [EP-A-1879], Patent Document 3 [EP-A-184458] and Patent Document 4 [US-A-4008203]. Blends of these polymers may be used. Poly p-phenylene sulfide films are also suitable.

  Suitable thermosetting resin substrate materials include addition polymerization resins (such as polyacrylates, vinyl resins, bis-maleimides and unsaturated polyesters), formamide condensate resins (condensates with urea, melamine or phenol, etc.) ), Cyanate resins, isocyanate resins, epoxy resins, functional polyesters, polyamides or polyimides.

  The film substrate for the polymerized film according to the present invention may not be oriented or preferably oriented (for example, uniaxial orientation), or in order to sufficiently combine mechanical properties and physical properties. Is more preferably biaxially oriented by stretching in two directions perpendicular to each other in the plane of the film. Film formation can be accomplished by any process known in the art of polymerized film manufacture, such as inflation or flat film methods.

  In the inflation method, simultaneous biaxial orientation is achieved by extrusion of a thermoplastic polymer tube that is subsequently quenched, reheated and then expanded by internal gas pressure to induce lateral orientation. As well as at a rate that induces vertical orientation.

  In the preferred flat film process, the film-forming polymer is extruded through a slot die and immediately quenched on the chill casting surface (drum) to ensure that the polymer is quenched and is in an amorphous state. Next, orientation is performed by stretching the rapidly cooled extrudate in at least one direction at a temperature higher than the glass transition temperature of the polymer. Continuous orientation can be achieved by drawing a flat quenched extrudate through a film stretching machine, first stretching in one direction (usually the longitudinal or forward direction) and then in the transverse direction. it can. Stretching the extrudate forward is conventionally done via a pair of rotating rolls or between two sets of nip rolls, followed by transverse stretching in a stenter device. Stretching is performed to a size determined by the nature of the film-forming polymer, for example, polyesters typically have a stretched polyester film size of 2.5 to 4.5 of the original dimension in each direction of stretch. Stretched to double.

  A stretched film can be dimensionally stabilized by heat set under dimensional constraints at a temperature above the glass transition temperature of the film-forming polymer, but below its melting point, to induce crystallization of the polymer. Is preferred.

  In a preferred embodiment, because the polymerized film of the present invention has low strain, reduced curl and improved flatness (or wrinkles), the polymerized film is 0.01 to 1.0% at 150 ° C. It has a percent thermal expansion (TD) in the transverse direction of the film and a percent thermal shrinkage (MD) in the machine direction of 0.4 to 2.0% at 150 ° C. The film has a TD expansion of 0.2 to 0.8% at 150 ° C. and a MD shrinkage of 0.5 to 1.5% at 150 ° C., in particular 0.3 to 0.5% TD expansion at 150 ° C. and 150 It preferably exhibits an MD shrinkage of 0.7 to 1.0% at ° C.

  For example, as described above, a substrate of the polymerized film of the present invention can be prepared during the production of a biaxially stretched film. In a typical method for the production of biaxially stretched films, the film is first stretched in the machine direction through a series of rotating rolls, then stretched in the transverse direction in a stenter oven, preferably followed by It is heat set under tension in the stenter. Lateral tension can be provided by a clip holding the film, which is attached to parallel rails on the opposite side of the stenter device. Lateral tension can be reduced, for example, by moving the rail inwards toward the exit end of the stenter (this is known as “toe-in”). By using toe-in, the film can be shrunk to some extent, and by using this method, a film having desired TD expansion and MD shrinkage characteristics can be obtained. The amount of toe-in used should be 0.1 to 10%, for example in the production of polyethylene terephthalate films, preferably 3 to 7%, in particular 3.5 to 6%. The exact amount of toe needed will depend on the particular film being manufactured and the other process conditions used. The stenter is preferably operated at a relatively high temperature. For example, in the case of a polyethylene terephthalate film, the stenter temperature is suitably 230 to 245 ° C, particularly 235 to 240 ° C.

  In one embodiment of the present invention, the polymerized film is transparent and exhibits high optical clarity and low haze, and the wide angle haze is <8% when measured according to standard ASTM D1003-61 for a preferred 175 μm thick film. More preferred is <6%, especially <5%, especially <3%. The optical properties can be appropriately achieved by having little or no particulate additive present in the substrate. The substrate may contain filler material in relatively small amounts, for example in the range of 5 to 3000 ppm, preferably 50 to 2000 ppm, more preferably 100 to 1000 ppm. Suitable fillers include inorganic materials such as silica, china clay, calcium carbonate, and organic materials such as silicon resin particles. Spherical monodisperse fillers may be used. The substrate may include a filler according to the normal practice of using recycled film in the film manufacturing process.

  However, in yet another embodiment of the present invention, the polymerized film is opaque, which means that for a preferred 175 μm thick film, a transmissive optical of 0.75 to 1.75, especially 1.2 to 1.5. Is defined as a film showing a typical density (Sakura densitometer; type PDA65; permeability mode). By incorporating an effective amount of opacifier into the synthetic polymer of the substrate layer, the polymerized film is conveniently rendered opaque. Suitable opacifiers include particulate inorganic fillers, incompatible resin fillers, or a mixture of two or more such fillers.

  The polymerized film may be translucent, i.e. having a transmissive optical density of up to 0.75.

  Granular inorganic fillers suitable for producing opaque film substrates include conventional inorganic pigments and fillers, especially metals or metalloid oxides (eg, alumina, silica and titania), and alkali metal salts (eg, calcium And barium carbonate and sulfate). Suitable inorganic fillers may be homogeneous and may consist essentially of a single filler material or compound (eg, titanium dioxide or barium sulfate only). Alternatively, at least a portion of the filler may be heterogeneous and the primary filler material may be associated with the additive modifying component. For example, the primary filler particles are treated with a surface modifier (eg, pigment, soap, surfactant coupling agent or other modifier) to make the filler compatible with the outer layer polymer. The degree is promoted.

  Suitable particulate inorganic fillers may be void-free or voided type, i.e. including a cellular structure containing at least some of the cells discretely closed by voids . Barium sulfate is an example of a filler that results in the formation of voids. Titanium dioxide may be voided or nonvoided depending on the particular type of titanium dioxide used. In a preferred embodiment of the invention, the film substrate comprises titanium dioxide particles, more preferably of the type without voids.

  The amount of the inorganic filler to be incorporated into the film substrate is desirably 2% by mass or more and not more than 40% by mass based on the mass of the substrate polymer. The concentration of the filler (suitable for titanium dioxide) is preferably in the range from 5% to 25% by weight, more preferably from 8% to 18%, in particular from 11% to 14%, based on the weight of the substrate polymer. A particularly satisfactory level of opacity is achieved when%.

  The inorganic filler particles preferably have a volume distribution median particle size in the range of 0.2 to 1.5 μm (accumulation equal to the diameter of a sphere corresponding to 50% of the volume of all particles, and the mass% of particles correlates with the diameter. Read on the distribution curve, often expressed as “D (v, 0.5) value”), more preferably 0.4 to 1.1 μm, in particular 0.6 to 0.8 μm, especially 0. It has a range of 65 to 0.75 μm.

  Preferred titanium dioxide particles may be in the anatase or rutile crystal form. The titanium dioxide particles are preferably predominantly anatase, more preferably at least 60% by weight, in particular at least 80% by weight, especially about 100% by weight of anatase. The particles can be prepared by standard techniques such as using chloride or preferably using sulfate.

  In one embodiment of the invention, the titanium dioxide particles are preferably coated with an inorganic oxide of an element such as aluminum, silicon, zinc, magnesium or mixtures thereof. Preferably, the coating further comprises an organic compound such as a fatty acid and preferably an alkanol, having 8 to 30, preferably 12 to 24 carbon atoms. Polydiorganosiloxanes or polyorganohydrogensiloxanes such as polydimethylsiloxane or polymethylhydrogensiloxane are suitable organic compounds.

  The coating is suitably applied to the titanium dioxide particles in an aqueous suspension. Inorganic oxides are precipitated in aqueous suspension from water-soluble compounds such as sodium aluminate, aluminum sulfate, aluminum hydroxide, aluminum nitrate, silicic acid or sodium silicate.

  The individual or primary titanium dioxide particles suitably have an average crystal size in the range of 0.05 to 0.4 μm as measured with an electron microscope, preferably 0.1 to 0.3 μm, more preferably 0.2 to 0.25 μm. In a more preferred embodiment of the invention, the primary titanium dioxide particles agglomerate to form clusters or aggregates comprising a plurality of titanium dioxide particles. The agglomeration process of the primary titanium dioxide particles may take place during the actual synthesis of titanium dioxide and / or during the production process of the polymer and / or polymer film.

  The film substrate optionally includes an “incompatible resin” which is a resin that does not melt or is substantially immiscible with the substrate polymer at the highest temperature that occurs during extrusion and secondary processing of the layer. Intended. Such resins include polyamide and olefin polymers for incorporation into polyester films, in particular mono-alpha-olefin homo- or co-polymers containing up to 6 carbon atoms in the molecule, or polyolefins. Polyesters as described above for incorporation into the film are included.

  The amount of incompatible resin, preferably polyolefin, for incorporation into the film substrate is preferably from 1% to 15% by weight, more preferably from 3% to 10% by weight, in particular based on the weight of the substrate polymer. It is in the range of 5% by mass to 8% by mass.

  Opacifiers by conventional techniques, for example by mixing with the monomer reactant from which the polymer is derived, by drive lending with the polymer in the form of granules or small pieces prior to film formation therefrom, or by using masterbatching techniques (Inorganic fillers are preferred) can be incorporated into the substrate layer polymer.

The pendant (—POXY) group of the polymer repeating unit of the coating layer is intended to be a group that is not part of the main chain of the polymer, ie a group that is present in the side chain attached to the main chain of the polymer. X and Y, which are the same or different, are OH or OM and M is a cation. M may be a metal ion, preferably an alkali metal ion, more preferably Li ⁺ , Na ⁺ or K ⁺ , or a tetramethylammonium ion. Both X and Y are preferably OH groups, ie preferred pendant groups are:

It is.

  Accordingly, the polymer of the coating layer preferably contains repeating units having pendant phosphate groups and / or salts or other derivatives thereof.

  Suitable repeat units are derived during the polymerization of monoethylenically unsaturated monomers containing phosphonic acid groups and may be aromatic, heterocyclic, aliphatic and alicyclic. Preferred monomers include vinylphosphonic acid, divinylphosphonic acid, allylphosphonic acid, methallylphosphonic acid, vinylphosphonic acid monomethyl ester, methacrylamide amidophosphonic acid, 2-arylamido-2-methylpropanephosphonic acid, 3-phosphono Propyl acrylate and 3-phosphonopropyl methacrylate are included. Vinyl phosphoric acid is a particularly preferred monomer.

  The polymer of the coating layer contains 5 mol% or more, preferably 10 to 90 mol%, more preferably 30 to 80 mol%, particularly 45 to 75 mol of repeating units containing phosphoric acid having the monomers described herein. Those containing in the range of mol%, especially 50 to 70 mol% are suitable.

  The polymer of the coating layer is preferably a copolymer containing one or more comonomers (preferably acrylic) in addition to the repeating units described herein. Suitable added comonomers are acrylic acid, methacrylic acid or derivatives of acrylic acid or methacrylic acid, preferably esters of acrylic acid or methacrylic acid, especially those in which the alkyl group contains up to 10 carbon atoms (for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, terbutyl, hexyl, 2-ethylhexyl, heptyl, and n-octyl)). Alkyl acrylates (such as ethyl acrylate or butyl acrylate) and / or alkyl methacrylates (such as methyl methacrylate) may be used.

  In a preferred embodiment of the invention, the coating layer polymer further comprises repeat units, which contain pendant carboxy groups, or groups that hydrolyze to form carboxy groups. Repeating groups containing suitable carboxy groups are derived during the polymerization of monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, or derivatives thereof. Acrylic acid is a particularly preferred comonomer containing a carboxy group.

  The polymer of the coating layer preferably contains 10 to 70 mol%, more preferably 30 to 60 mol%, especially 30 to 55 mol%, especially 30 to 30% of repeating units containing pendant carboxyl groups as described herein. To 50 mol%.

  Other comonomers suitable for use in preparing the coating layer copolymer include acrylonitrile, methacrylonitrile, halo-substituted acrylonitrile, halo-substituted methacrylonitrile, hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, itaconic acid, anhydrous Itaconic acid and half-esters of itaconic acid are included. Other optional comonomers include vinyl esters such as vinyl acetate, vinyl chloroacetate and vinyl benzoate; vinyl pyridine; vinyl chloride; vinylidene chloride; maleic acid; maleic anhydride; butadiene; Monomers, including styrene and derivatives of styrene (such as chlorostyrene, hydroxystyrene and alkylated styrene). A preferred class of comonomers includes sulfonated monomers such as vinyl sulfonic acid or salts or other derivatives thereof (eg, sodium vinyl sulfonate). Other suitable salts of vinyl sulfonic acid include potassium and lithium salts.

  The coating preferably comprises 1 to 60 mol%, more preferably 3 to 50 mol%, especially 5 to 30 mol% of such sulfonated comonomers in the coating layer copolymer.

  A preferred coating layer polymer is a poly (acrylic acid-co-vinylphosphonic acid) copolymer. Further preferred coating layer polymers are terpolymers comprising portions of acrylic acid, vinyl phosphonic acid and sodium vinyl sulfonate.

  The molecular weight of the polymer of the coating layer may vary over a wide range, but the average molecular weight is preferably less than 5,000,000, more preferably in the range of 2,000 to 200,000, in particular 25,000 to 100. In the range of 35,000, especially in the range of 35,000 to 80,000. The amount of coating layer polymer present in the coating layer composition is preferably in the range of 0.1 to 50% by weight, more preferably 0.1 to 20% by weight, relative to the total solids of the composition. %, In particular 0.5 to 10% by weight.

  The coating layer composition may further comprise a resin that can enhance toner adhesion to the coating. Suitable resins include acrylic polymers and copolymers, styrene homopolymers and copolymers, acrylonitrile, sulfonated polyesters, and blends of the aforementioned polymers and copolymers. One preferred type of resin to be compatibilized is a copolymer of styrene and an acrylic monomer, such as the resin sold by Zeneca as Neocryl BT70.

  In one embodiment of the invention, the coating layer comprises an inorganic filler, and particulate materials such as silica, alumina, titanium dioxide and / or metal oxides are suitable.

  The inorganic filler particles have a volume distribution median particle size in the range of 0.1 to 10 μm (equal to the diameter of a sphere corresponding to 50% of the volume of all particles, and the cumulative distribution curve in which the mass% of particles correlates with the diameter. Preferably read and often expressed as “D (v, 0.5) value”.

  The particle size of the filler particles can be measured by an electron microscope, a Coulter counter, sedimentation analysis and light scattering, and a technique based on laser light diffraction is preferred.

  The amount of inorganic filler present in the coating layer composition is preferably in the range of 0.001 to 30% by weight, more preferably less than 10% by weight, relative to the total solids of the composition.

  The coating layer optionally includes a cross-linking agent (preferably having a low molecular weight). As the crosslinking agent, an organic substance is suitable before the formation of the coating layer, and monomer species and / or oligomer species, particularly monomer species are preferred. The molecular weight of the cross-linking agent is preferably less than 2000, more preferably less than 1500, in particular less than 1000, especially in the range from 250 to 500. Suitable crosslinkers include alkyd resins, amine derivatives such as hexamethoxymethylmelamine, and / or amines (eg, melamine, diazine, urea, cyclic ethylene urea, cyclic propylene urea, thiourea, cyclic ethylene thiourea, aziridine, alkyl Melamine, aryl melamine, benzoguanamine, guanamine, alkyl guanamine, aryl guanamine, etc.) and condensation products of aldehydes (eg, formaldehyde) may be included. A preferred cross-linking agent is a condensation product of melamine and formaldehyde. The condensation product may optionally be alkoxylated. It is also preferable to use a catalyst in order to promote the crosslinking action of the crosslinking agent. Preferred catalysts for crosslinking of melamine formaldehyde include ammonium chloride, ammonium nitrate, ammonium thiocyanate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, paratoluene sulfonic acid, sulfuric acid, base stabilized maleic acid, ammonium paratoluene sulfone. Acids and morpholinium paratoluene sulfonic acid are included.

  A more preferred crosslinking agent is dimethylol urea.

  In order to promote intermolecular crosslinking with the functional groups present in the hydroxyalkyl cellulose and to improve the adhesion of the coating layer to the substrate surface, the crosslinking agent has at least three functionalities (ie, three functional groups). Is preferable.

  The amount of crosslinking agent present in the coating layer composition is preferably in the range of 0.1 to 25% by weight, more preferably 0.15 to 10% by weight, relative to the total solids of the composition. In particular from 0.2 to 5% by weight, in particular from 0.25 to 2% by weight.

  The ratio of coating layer polymer to crosslinker present in the coating layer composition and consequently present in the coating layer is preferably in the range of 500 to 0.005: 1 by weight. More preferably from 150 to 0.01: 1, in particular from 50 to 0.1: 1.

  If necessary, the coating layer composition may further include a surfactant to promote spreading when applied to the film substrate.

  In addition, the coating layer advantageously includes a stretching agent, which preferably includes an alkylaryl phthalate to facilitate processing of the film to the desired thickness.

  The surface of the coating layer is hydrophilic and preferably exhibits a water contact interior angle of less than 70 °, more preferably less than 55 °, especially less than 50 ° when measured as described above. The surface of the coating layer preferably exhibits an oil-in-water contact angle of greater than 140 °, more preferably greater than 145 °, and particularly greater than 150 ° when measured as described above.

  The difference between the water contact angle and the oil-in-water contact angle is preferably greater than 75 °, more preferably at least 90 °, and most preferably greater than 95 °.

  The coating layer composition (preferably in the form of an aqueous dispersion) may be applied to the substrate film surface by conventional coating techniques. The applied medium generally has a solids content in the range of 1 to 30, preferably 2 to 15, in particular 5 to 10% by weight, and is immediately dried to remove the dispersant, as well as to crosslink the layers. Achieved. Drying may be accomplished by conventional techniques, such as passing the coated film through a hot air oven. Drying may be performed during normal film processing (such as heat setting) after formation.

  The thickness of the dried coating layer is preferably greater than 0.1 [mu] m, more preferably greater than 0.4 [mu] m, especially thin and 1.0 [mu] m.

  The coating layer composition may be applied to an already oriented film substrate. However, the application of the coating medium is preferably performed before or during any stretching operation. In particular, according to the present invention, the hydrophilic coating composition is preferably applied to the film during the two stages (longitudinal and transverse) of the biaxial stretching operation. Such a sequence of stretching and coating is particularly preferred for the production of linear polyester films such as polyethylene terephthalate film, which film is preferably first stretched longitudinally through a series of rotating rolls and coated. It is preferably coated with the layer composition and then stretched in the transverse direction in a stenter oven and subsequently heat set.

  The back surface of the polymerized film, away from the coating layer according to the present invention, does not have to be treated and has a functional layer (such as a release layer, a back layer or a charged layer) on it. Also good.

  The polymerized film of the present invention may contain any agent conventionally used in the production of polymerized films. Therefore, agents such as dyes, pigments, lubricants, antioxidants, antistatic agents, surfactants, slip agents, adhesion improvers, scratch resistance enhancers, gloss improvers, prodegradants, flame retardants, and UV stabilizers May be appropriately combined with the substrate and / or the coating layer.

  The polymerized film may vary in thickness according to the intended use, but the film preferably has an overall thickness in the range of 5 to 350 μm, more preferably from 25 to 250 μm, especially from 125. 200 μm.

  The following test methods herein are used to measure specific properties of filler particles and polymerized films.

(Contact angle)
The water contact angle was obtained by imaging the distribution of 5 μl distilled water test solution droplets on the sample surface. This angle was measured by projecting a negative and drawing a tangent to the droplet distribution at the point of contact of the three layers. The angle quoted in the standard deviation is the average of the angles measured for 9 droplets of each liquid. The standard deviation was 4.

(Water-in-oil contact angle)
The contact angle of mineral oil (Castol Solvent Neutral 150) on the test surface soaked with water in the surroundings reversed the sample test surface in a glass cell (60 × 50 × 55 mm) containing distilled water, and a drop of oil It was measured by inserting (10-40 μl) into the back of the surface soaked in water using a syringe and a bent needle. Droplet distribution images were captured using the FTA-200 Dynamic Contact Angle System, and contact angles were automatically calculated using instrument software. The quoted contact angle is an average of 9 drops. The standard deviation was 4.

(Filler particle analysis)
Volume distribution median particle size, and particle size distribution ratios D ₂₅ / D ₇₅ and D ₁₀ / D ₉₀ were measured using a Coulter LS130 (Coulter Electronics Ltd. Luton, UK) particle sizer.

  BET specific surface area was measured by multi-point nitrogen adsorption using a Micromeritics ASAP 2400 (Micromeritics Limited, Dunstable, UK). A relative pressure between 0.05 and 0.21 was used and the degassing conditions were 1 hour at 140 ° C. with a nitrogen purge (1 to 2 liters / hour).

  Skeletal density was measured by the helium specific gravity method using Micromeritics Accupyc 1330 (Micromeritics Limited, Dunstable, UK).

(Adhesion to toner)
Toner adhesion to the hydrophilic coating was estimated by measuring the amount of toner removed from the coating by the following method:
The test image (toner) was printed on a sample of coated film using a Xante laser printer. The test image consisted of 8 black rectangular blocks. The optical density of each of the 8 blocks was measured using a color transmission-reflection densitometer (type Macbeth TR927, supplied by Optronic Color Communications). Measurements of highest and lowest ignore records average values of the other six values as V _1. Next, a piece of adhesive tape (Tesa 4104) was applied and the toner was removed from one block by peeling off the tape in the usual manner. In the region to remove toner, carried further eight times densitometer measurements, an average value (measured value of the highest and lowest ignored) compared the V ₂ and the average value of the foregoing. The percent of toner removed was calculated according to the following formula:

Removed toner = (V ₁ / V ₂ ) × 100%

  The invention is illustrated by reference to the following examples.

(Experimental methods and materials)
The materials used to make up the coating formulations described below are detailed in Table 1. The composition of each formulation is shown in Table 2.

(Examples 1 and 2)
A transparent polyethylene terephthalate polymer was coextruded with a polyester copolymer made of 18% isophthalate + 82% terephthalate + ethylene glycol, poured onto a cooled rotating drum and stretched in the extrusion direction to about 3 times its original length. . The copolymer side of the cooled stretched film was coated with an aqueous coating composition containing specific amounts of the following components by offset gravure application using a rubber ink roller.

A polyester film was coated only on one side. The coated film was passed through a stenter oven to dry the film and stretched laterally to about 3 times its original length. The biaxially stretched coating film was heat set to a temperature of about 200 ° C. by a conventional method. The final coating thickness was 0.03 to 0.05 μm with a coating mass of about 0.3 to 0.5 mgdm ⁻² . The surface properties of the coating film and toner adhesion were tested as described above and the results are shown in Table 3.

Example 3
A coating formulation was prepared as shown in Table 2 and the film was coated in the same manner as described in Examples 1 and 2. The coatings were dried at three different coating masses so that the dried coating thicknesses were 2.8, 1.2 and 0.7 μm. The water contact angle was measured and the results are shown in Table 3. The results show that the thicker the film, the smaller the water contact angle and hence the more hydrophilic.

  Santizer 261 is a stretching agent and is used in a 2% micro-emulsion. Examples 7 and 8 were used to prepare micro-emulsions.

  200 ml of pure Santizer 261 and 800 ml of pure Synperonic NP10 are placed in a clean plastic bottle. Turn the lid tight and shake well until it produces a clear, one layer of liquid. The mixture was slowly poured into a container containing 9 liters of deionized water while stirring. Stir for 10 minutes and wait for the foam to disappear.

(Examples 4 to 9)
The coating formulations shown in Table 2 were prepared and the films were coated in the same manner as described in Examples 1 and 2.

  The results for the water contact angle in Table 3 indicate that the water contact angle is substantially reduced by adding a stretching agent such as glycol, particularly Santizer 261.

Claims (14)

  A polymerized film substantially free of gelatin, the polymerized film comprising a polymerized film substrate having a coating layer on at least one surface thereof, the coating layer comprising a polymer having at least one or more repeating units, A polymerized film characterized in that the repeating unit comprises at least one or more pendant groups —POXY, wherein X and Y may be the same or different, are OH or OM, and M is a cation.   The film according to claim 1, wherein the polymer of the coating layer includes a repeating unit having a pendant phosphonic acid group and / or a salt or derivative thereof.   The film of claim 1 or 2, wherein the polymer of the coating layer comprises a copolymer having one or more acrylic comonomers. A film according to any preceding claim, wherein the polymer of the coating layer further comprises a repeating unit comprising a pendant carboxy group or a group capable of forming a carboxy group upon hydrolysis.   The film of claim 4, wherein the polymer of the coating layer comprises a copolymer of acrylic acid and vinylphosphonic acid.   6. A film according to any one of the preceding claims, wherein the polymer of the coating layer further comprises a comonomer that is a sulfonated monomer or a salt or other derivative thereof.   A film according to any one of the preceding claims, wherein the polymer of the coating layer comprises a copolymer of acrylic acid, vinylphosphonic acid and sodium vinylphosphonate.   The film according to any one of the preceding claims, wherein the coating layer further comprises a drawing agent.   9. A film according to claim 8, wherein the stretching agent comprises an alkylaryl phthalate.   The film according to any one of the preceding claims, wherein the polymer of the coating layer further comprises a filler.   The film according to any one of the preceding claims, wherein the polymer of the coating layer further contains a crosslinking agent.   A method for producing a polymerized film comprising the steps of forming a polymerized film substrate, applying a coating composition to at least one surface of the substrate, wherein the coating composition comprises at least one pendant (-POXY) group. A method comprising: having a polymer having at least one repeating unit having: wherein X and Y, which are the same or different, are OH or OM and M is a cation.   13. The method of claim 12, wherein the coating composition is applied to the substrate before or during any stretching operation used to achieve molecular orientation of the film substrate.   A printing plate comprising a polymerized film substrate having a coating layer on at least one surface, wherein the coating layer comprises a polymer having at least one repeating unit having at least one pendant (-POXY) group Wherein X and Y, which are the same or different, are OH or OM and M is a cation.