Abstract: A film forming, radiation sensitive resist composition having improved thermal stability and a reduced dissolution rate in developer solutions, comprised of a sensitizer and a polyalkenyl phenol such as a polyvinyl phenol cross-linked, prior to irradiation, with a poly-functional cross-linking agent such as dimethylol p-cresol or hexamethylene tetramine.

Abstract: Disclosed is a two-component diazotype material comprising a support and a light-sensitive layer containing (a) at least one diazonium compound derived from p-phenylenediamine and carrying a basic heterocyclic radical in the 4-position and ether groups in the 2- and 5-positions, (b) a coupler component, and (c) an acid stabilizer, the diazonium compound being present in the form of a benzenesulfonate or toluenesulfonate. The disclosed materials have a good storability and are easily developed.

Abstract: A photosensitive lithographic plate comprising a hydrophilic substrate, a photosensitive diazo resin layer superposed on the substrate, and a layer of a photosensitive polyvinyl acetal resin containing an aromatic azide group in a side chain thereof and having an acid number of 10 to 100 and superposed on the diazo resin layer, and a method for the manufacture of this photosensitive lithographic plate.

Abstract: A photosensitive composition containing a polymer, and a photosensitive material utilizing the composition are disclosed. The polymer, which may be in the form of a copolymer, includes a repeating unit of the formula (I): ##STR1## wherein Y is a divalent substituent; Z.sub.1 and Z.sub.2 independently each represents monovalent substituents; p and q are each 0 or an integer of 1 to 4; when p and q are each 2 or more, each of Z.sub.1 and Z.sub.2 may be the same or different; X.sup..crclbar. is an anion. The composition has high sensitivity and is capable of forming an image on a suitable photographic support without causing fog under incandescent lamps. The composition can be used to produce lithographic printing plates having high sensitivity as well as excellent ware resistance.

Abstract: Disclosed is a developer composition for exposed, light-sensitive, negative-working reproduction layers, which may contain an organic binder, comprising water and a salt of a substituted aromatic carboxylic acid, in particular, from about 5 to 60% by weight of at least one salt of an aromatic carboxylic acid having substituents which are immediately adjacent to the carboxyl group and represent an amino group, a hydroxyl group, and/or chlorine or bromine. Also disclosed is a process for developing the reproduction layers utilizing the disclosed developers, wherein the reproduction layer contains, in particular, a polymeric organic binder with an acetal, anhydride, amide and/or a carboxyl group.

Abstract: An image forming material comprises an image forming layer disposed on a support and comprising (a) aqueous composition comprising a hydrophilic binder layer containing metal developing nuclei or their precursor compound, and water and (b) an organic composition comprising an oil-soluble development inhibitor which is a compound having a diazo group or azide group and a water-miscible organic solvent. An image is formed by exposing the image forming layer to patternized light and then contacting it with a developer containing reducible metal ions and a reducing agent thereby to form an image constituted by metal particles grown at the light-exposed parts.

Abstract: A relief image-forming composition having an acidic pH comprises a photosensitive component and an indicator capable of existing in two states differing in actinic opacity dependent upon pH. A relief image is formed by (1) exposing to light selected areas of a layer of the composition, the indicator being in its state of lower actinic opacity, (2) removing layer material from the exposed areas or from the unexposed areas and (3) shifting the pH in the remaining layer material to a value at which the indicator exists in its state of higher actinic opacity. The resultant image can then be used as an intermediate original in diazotype copying processes.

Abstract: A presensitized lithographic plate is disclosed. The plate is comprised of a support base such as an aluminum support base having an anodized surface having a subbing layer positioned thereon which is coated with a light-sensitive layer. The light-sensitive layer is comprised of a diazo compound and a binder or comprised of a photopolymerizable composition. The subbing layer is comprised of a high molecular compound containing a sulfonic acid group-containing monomer units as recurring units. The subbing layer provides a lithographic plate which has greatly improved shelf life. The subbing layer increases the stability of the lithographic plate such that when the plate is stored it continues to be capable of producing copies which do not have stained background areas even when the plate is stored under adverse temperature and humidity conditions.

Abstract: A developer is provided for lithographic plates or the like having a layer including a diazonium material, which developer enhances the effectiveness of the photolysis to which the plate had been subjected, with the result that the exposure time needed for the plate is substantially reduced. The developer, which thus enhances the apparent photospeed of the plate, includes an insolubilizing reactant that reacts with diazonium groups of diazonium materials on the plate that were not removed by photolysis during exposure in order to decrease the solubility of the diazonium material.

Abstract: A presensitized lithographic printing plate precursor is described, comprising an aluminum support that has been rendered hydrophilic having provided thereon a light-sensitive layer composed of a light-sensitive composition comprising (1) an organic solvent-soluble and substantially water-insoluble diazo resin, (2) a substantially water-insoluble, film-forming polymeric compound, and at least one of (3a) an organic solvent-soluble polymeric compound having a sulfonic acid group or a sulfonic acid salt group in its side chain and (3b) a substituted or unsubstituted dipicolinic acid or a salt thereof, the total amount of (3a) and (3b) components being about 1 to about 100% by weight, based on the weight of the diazo resin.

Abstract: The invention relates to an adhesive composition which is suitable for use on a shaped part of polyester, in particular a polyester film, and comprises a copolyester, optionally in combination with light-sensitive substances, fillers and pigments, whereby the copolyester additionally contains at least one copolymer of vinylidene chloride, preferably in a weight ratio of about 3:1 to 1:1. The adhesive composition can furthermore contain cellulose acyl esters, such as low molecular-weight cellulose acetobutyrate or cellulose propionate. Polybasic oxycarboxylic acids and levelling agents can also be present. The adhesive composition can be employed in mixtures with, for example, light-sensitive lacquer systems.

Abstract: A diazo-type thermosensitive recording material comprising a support material, a thermosensitive coloring layer formed thereon, which thermosensitive coloring layer comprises a diazonium compound layer containing a diazonium compound, and a coupler layer containing a coupler, and of the diazonium compound layer and the coupler layer, at least the lower layer near the support material further containing a thermo-fusible material and a water-insoluble binder agent, and in any portions other than the diazonium compound layer of the thermosensitive recording material, an imidazole derivative of the following formula being contained: ##STR1## wherein R.sup.1 represents a higher alkyl group, preferably with 6 to 24 carbon atoms, an alkoxyl or hydroxyalkyl group derived from the above higher alkyl group; R.sup.2, R.sup.3 and R.sup.4 independently represent hydrogen, a phenyl group, a benzyl group, an alkyl group, an alkoxyl group, an hydroxyalkyl group or a cyanoalkyl group.

Abstract: A water developable printing plate is provided with a photopolymerizable system as a latex comprising a water soluble diazopolymer reaction product of a diazoaryl amine and an aldehyde and an aqueous cationic or nonionic dispersion of a water insoluble polymer. The inclusion of a water miscible organic solvent improves the shelf-life of the photopolymerizable system and the printing plate especially under high humidity conditions.

Abstract: The invention provides photosensitive compositions useful in the production of screen printing stencils which comprise, in addition to the usual ingredients, also an indicator to show when a layer formed from the said composition has been isolubilized by exposure to actinic light.

Abstract: A photosensitive material of the diazonium type which comprises a support, a precoat layer thereon and a photosensitive layer of a diazonium compound is improved by using a graft copolymer on a cellulose derivative as the precoat layer. A hydrophilic epoxy compound may be used in the precoat layer and a coupler and a benzenediazonium hexafluorophosphate derivative may be used in the photosensitive layer.

Abstract: This invention relates to light sensitive water soluble diazonium compound condensation products stabilized against degradation caused by heat and/or prolonged storage employing selected amino acids as stabilizers. The invention also relates to presensitized reproduction materials comprising the amino acid stabilized water soluble diazonium compound condensation products.

Abstract: A process for the rapid curing of polyurethanes comprising the steps of (a) mixing together a diisocyanate compound, a diol, a polyol, and a diazonium salt and thereafter (b) exposing the resulting mixture to ultraviolet light in the wavelength range of about 2000 to about 4000 Angstroms for a period of about 0.1 second to about 20 minutes at a temperature in the range of about 0.degree. F. to about 180.degree. F.

Abstract: A presensitized article having a radiation-sensitive layer comprising an adduct of an amorphous sulfopolyester and a diazonium resin is described which does not exhibit blocking on being stored in stacks for prolonged periods of time. The article can be exposed to radiation and developed via aqueous solvents to provide a lithographic plate that provides clean, scum-free copies, and that can be stored in a high humidity atmosphere without failure.

Abstract: A negative working light-sensitive composition and a lithographic printing plate using the composition are described. The printing plate is comprised of a hydrophilic support and a thin layer of a negative working light-sensitive composition on the support. The light-sensitive composition contains a light-sensitive diazo compound and a compound capable of increasing absorption over the light-sensitive wavelength region of the composition with increasing exposure time.

Abstract: The present invention relates to a two-component diazotype material comprising a support and one or several light-sensitive layers, each of which contains at least one light-sensitive diazonium salt, a coupler component and an acid stabilizer, and at least one of the layers contains a compound which absorbs light in the ultraviolet spectral region. The light-absorbing compound is present in the form of a dye salt of at least one benzothiazole which is converted into its leuco base under the action of an alkaline medium. It thus partially or completely loses its absorptivity toward radiation in the long-wave ultraviolet and short-wave visible spectral regions. The light-absorbing compound comprises a benzothiazole, in particular according to the general formula: ##STR1## wherein R.sub.1 denotes hydrogen, alkyl or aralkyl,R.sub.2 denotes hydrogen or an optionally substituted alkyl, aralkyl, aryl, pyridylalkyl, carbalkyl, carboxyalkyl, carboxyaryl, carbamoyl, or sulfamoyl radical, orR.sub.1 and R.sub.

Abstract: An improved resin coated substrate is prepared by coating a suitable substrate, such as aluminum with a composition comprising a salt having the structure A-N.sub.2.sup.+ X.sup.- wherein A is an aromatic or heterocyclic residue and X is an anion of an acid; and a binder composition comprising both an acrylic polymer and an acid containing acrylic copolymer.

Abstract: A water-soluble, positive-working photoresist composition is disclosed which comprises water-soluble aromatic diazonium salt, water-soluble phenolic compound, and water-soluble polymeric compound. When the film of this composition is irradiated with a pattern of actinic ray and then brought into contact with an alkaline gas or solution, the coating of unexposed areas hardens to become water-insoluble. Preferably, when the film is brought into contact with a suspension of powder or dry powder after being hardened, a positive pattern of powder is obtained by the development with water.

Abstract: This invention relates to light sensitive diazonium compound condensation products stabilized against degradation caused by heat and/or prolonged storage employing, as stabilizers, an acid selected from the group consisting of benzoic acid, m-nitro benzoic acid, p(p-anilino phenylazo) benzene sulfonic acid, 4,4'-dinitro-2,2'-stilbene disulfonic acid, itaconic acid, and mixtures thereof. The invention also relates to presensitized reproduction materials comprising the acid stabilized diazonium compound condensation products.

Abstract: A light- and heat-sensitive recording material is disclosed. The material include microcapsule in which are encapsulated a particular combination comprised of a vinyl compound, a photopolymerization initiator, and a color forming component being capable of undergoing a color reaction with another color forming component to cause color formation. These coloring components are provided on the same side of a support.

Abstract: A method for forming a pattern of a non-light-emitting black material on the inner surface of a faceplate of a color cathode ray tube is provided, which comprises the steps of forming a photoresist layer of a photoresist containing a water-soluble bisazidocompound, a water-soluble diazocompound, and a water-soluble polymeric material, on an inner surface of a faceplate of a color cathode ray tube, selectively exposing parts of the photoresist layer using a shadow mask so as to photocure the exposed parts, developing the photoresist layer to remove unexposed parts of the photoresist layer, thereby forming dots of the photoresist, forming a film of a non-light-emitting black material on the inner surface of the faceplate including the dots, and removing the dots and the non-light-emitting black material on the dots so as to form holes in the film of the non-light-emitting black material.

Abstract: This invention relates to a positive photoresist system possessing a high degree of thermal stability. The photoresist system contains a preformed polyglutarimide polymer dissolved in a non-reacting solvent. The positive resist is capable of achieving high resolution images by exposure to a wide range of wavelengths and development using an aqueous base developer. The photoresist system is also suitable for use as a planarizing layer in a multiple layer system.

Abstract: A novel photosensitive film structure comprises a generally continuous minor phase material and a generally discontinuous major phase material. The minor phase includes a photosensitive compound whose solubility relative to a selected solvent changes upon exposure to electrromagnetic radiation, while the major phase is not photosensitive nor soluble in the solvent. The two phases are uniformly interdispersed throughout the film structure. Imagewise exposure to electromagnetic radiation renders the film structure selectively permeable to the selected solvent, and, after development, the film structure exhibits the chemical and physical properties of the major phase material. The film structure finds varied application in the manufacture of graphic arts articles such as lithographi printing plates and photoresists.

Abstract: Vesicular imaging films have good speed and stable latent images when comprised of a diazonium compound, nitrate salt, and binder comprising gelatin or poly(vinyl alcohol). The film can even have highly stable final images when the binder comprises poly(vinyl alcohol).

Abstract: An improved negative working photographic element is prepared by coating a suitable substrate with a photosensitive composition comprising a light sensitive diazonium salt and a binder composition comprising a polyvinyl acetate resin and a styrene/maleic acid half ester copolymer. Upon imagewise exposure of the element to actinic radiation through a suitable mask, the unexposed portions are removable with an aqueous developer.

Abstract: Photo-fixing heat-sensitive recording media which comprise diazonium salts, couplers and/or basic materials, all of these components being insoluble or sparingly soluble in water. At least one of these components is present in the media in the form of a fine powder. The coupler may be a coupler which has a basic group therein and serves as both a coupler and a basic material.

Abstract: A photosensitive plate suitable for preparation of a waterless lithographic printing plate, which comprises a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising an emulsion polymerization product of an acrylic or methacrylic monomer having a perfluoroalkyl group in the side chain and a water-soluble photosensitive substance resin whose water-solubility is variable by irradiation of ultraviolet rays.

Abstract: An improved diazotype photoprinting material of high printing speed and its method of preparation are disclosed. The improvement is achieved by distributing through the film coating a substantially uniform distribution of sites having a refractive index substantially different from that of the remainder of the coating. The sites consist of either voids or finely divided solids. Voids are created by contacting the film coating with an aqueous fluid at elevated temperature or an organic solvent for a sufficient period of time to cause a measurable haze to appear on the film. The sites operate to reflect or refract incident light rays during imagewise exposure, and thus increase the optical path length through a given thickness of film.

Abstract: A method for forming a pattern of a non-light-emitting black material on the inner surface of a faceplate of a color cathode ray tube is provided, which comprises the steps of:forming a photoresist layer of a photoresist containing a water-soluble bisazidocompound, a water-soluble diazocompound, and a water-soluble polymeric material, on an inner surface of a faceplate of a color cathode ray tube;selectively exposing parts of the photoresist layer using a shadow mask so as to photocure the exposed parts;developing the photoresist layer to remove unexposed parts of the photoresist layer, thereby forming dots of the photoresist;forming a film of a non-light-emitting black material on the inner surface of the faceplate including the dots; andremoving the dots and the non-light-emitting black material on the dots so as to form holes in the film of the non-light-emitting black material.

Abstract: Images are prepared by a process in which a layer, supported on a substrate, of a liquid composition comprising(a) an anaerobically polymerizable material and(b) a photopolymerizable material is maintained in a substantially oxygen-free environment such that the composition solidifies. It is then exposed imagewise to actinic radiation and treated with a developer to remove parts of the layer which have not been struck by the radiation.The anaerobically polymerizable and photopolymerizable materials may be a mixture of two or more materials having these different functions, such as an acrylate ester with an azido compound, or the two functions may be combined in a single molecule. The products are suitable for use in producing printing plates and printed circuits.

Abstract: Plates such as those used in lithographic printing and photoresists such as those used in preparing printed circuit boards and the like are provided with a photopolymerizable photosensitive diazo resin that is unusually stable. The diazo resin is laid down from a stabilized diazonium composition that is an emulsion including the selected diazo resin, a purine derivative, especially a theophylline derivative, preferably in combination with a salt of a low molecular weight alkyl sulfonic acid or other supplementary stabilizer component.

Abstract: A thermal development type diazo copying material comprising a support material and a photosensitive layer formed on the support material, which photosensitive layer comprises a diazo compound, a coupling component and a thermo-fusible auxiliary coloring agent, and which coupling component is capsulated by a hydrophobic polymeric material with a softening point ranging from 50.degree. C. to 150.degree. C. selected from the group consisting of hydrophobic polyester resins, hydrophobic cellulose resins, hydrophobic polyamide resins and hydrophobic polyurethane resins.

Abstract: An aqueous diazo coating composition is disclosed to be used in accordance with an alkaline vapor development system, containing a hydrolyzed resin together with a diazo light-sensitive compound, coupling agent and stabilizing materials. The aqueous diazo coating composition of the present invention provides a method of fabricating a light-sensitive diazo member for use in combination with a development system utilizing alkaline vapors which excludes the use of organic solvents.

Abstract: A light-sensitive diazonium group-containing polycondensation product of a diazonium salt corresponding to the general formula ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 denote hydrogen atoms, halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, andX denotes the anion of the diazonium salt,and an aldehyde selected from the group consisting of dialdehydes, acetals of dialdehyde hydrates, and esters of dialdehyde hydrates, a process for producing such a light-sensitive polycondensation product and a light-sensitive recording material comprising a layer support and a light-sensitive layer containing such a light-sensitive polycondensation product.

Abstract: This invention relates to a derivative of 2-hydroxy-naphthalene of the general formula ##STR1## wherein A is ##STR2## and X is --OH or ##STR3## and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are identical or different and are hydrogen, cycloalkyl having up to eight carbon atoms, which is optionally substituted by lower alkyl groups, aralkyl having up to 10 carbon atoms or aryl which is substituted by lower alkyl, lower alkoxy, halogenalkyl or alkyl-substituted amino groups or by halogen, or R.sub.1 and R.sub.2 or R.sub.3 and R.sub.4 in each case are, conjointly with the nitrogen atom to which they are attached, identical or different heterocyclic groups which are optionally substituted by lower alkyl.

Abstract: Resists sensitive to UV, electron beam and X-ray radiation with positive or negative tone upon proper choice of a developer are formulated from a polymer having recurrent pendant groups such as tert-butyl ester or tert-butyl carbonates that undergo efficient acidolysis with concomitant changes in polarity (solubility) together with a photoinitiator which generates acid upon radiolysis. A sensitizer component that alters wavelength sensitivity may also be added.

Abstract: Photoresist compositions based upon a water-soluble polymer are disclosed together with a water-soluble bisazide compound as a cross-linker, a water-soluble adhesion-improving diazo compound are characterized in that a water-soluble silane compound is included. The compositions are photosensitive, particularly to ultraviolet rays, and adhere well to the substrates to which they are applied. The compositions of the invention are used as photoresists.

Abstract: A diazotype heat development recording medium of the present invention has excellent shelf life and heat sensitivity. The medium comprises a support and a recording layer which is formed on said support and which comprises a diazo compound, a coupler, an acid stabilizer, a thermal developer, and a polymeric binder. The thermal developer is a salt of an organic or inorganic acid having a primary dissociation constant of 2.times.10.sup.-1 to 1.times.10.sup.-4 and an alkyl-substituted guanidine represented by the general formula: ##STR1## (wherein at least one of R1 and R2 is an alkyl group of C.sub.8 to C.sub.24, and the other of R1 and R2 is a hydrogen atom or an alkyl group of C.sub.1 or more).

Abstract: Light-sensitive compositions and materials incorporating such compositions, such as coated films for the production of polymeric resists, comprise a diazo-resin as a sensitizer for the composition and a water-soluble or water-dispersible colloid. In order to stabilize the diazo-resin sensitizer and increase the time between manufacture and use of such light-sensitive compositions and material, a poly-(vinylpyridine) is incorporated in the composition, preferably in the form of a water-soluble salt such as the hydrochloride or sulphate.

Abstract: Bilayer photosensitive imaging articles comprising a substrate coated with an image layer and a resist layer are disclosed. The substrate may be transparent, translucent or opaque to give imaging articles useful in different applications. The image layer which should be from about 0.3-3.0 microns in thickness includes an organic film-forming vehicle from the group of copolymers of the formula: ##STR1## where P is styrene, ethylene or methyl vinyl ether; m is 1-3; n is 1,10; X is OH, OHN.sub.2, ONH.sub.4, OR, ONH.sub.3 R, ONH.sub.2 R.sub.2, ONHR.sub.3, ONH.sub.3 RNH.sub.2, ONa, OK, OLi; R is an alkyl group in the range C.sub.1 -C.sub.10 optionally including a functional group such as ketone, alcohol, esther, ether alcohol or aryl; m=1-3, n=1-10; and the molecular weight is between 1,000-150,000. The image layer may also include a coloring medium. The resist layer, which should be from about 0.5 to about 2.

Abstract: Diazotype material having enhanced water-wet properties and especially suitable when imaged for being drawn or written upon, and for use as an intermediate original, is made of a support such as a transparent polymeric film carrying on one of its sides a light sensitive diazo layer formed of a dispersion of a light sensitive diazonium compound and a large amount of amorphous hydrated silica particles having a bound water content of at least 50% by weight in a polymeric binder consisting essentially of a 20 to 45% hydrolyzed polyvinyl acetate which preferably is a product of partial hydrolysis of a PVAC having in ethyl acetate at 20.degree. C. a Heoppler viscosity of 100 to 800 mPa.s. The weight ratio of the hydrated silica to the partially hydrated PVAC in the layer typically is in the range of 2:3 to 3:2. The support advantageously carries on its other side a light-pervious drafting layer formed of a dispersion of a silica filler in a partially hydrolyzed PVAC the same as that required for the diazo layer.

Abstract: The invention provides a photographic element having a substrate and a photosensitive coating on the substrate, said coating containing(A) the polycondensation product of 3-methoxy-4-diazodiphenyl amine sulfate and 4,4'-bis-methoxy methyldiphenyl ether, precipitated as methane sulfonate; and,(B) the polycondensation product of 3-methoxy-4-diazodiphenyl amine sulfate and 4,4'-bis-methoxy methyldiphenyl ether, precipitated as mesitylene sulfonate, and(C) at least one colorant: and(D) at least one water soluble polymeric binding resin which is preferably polyvinyl pyrrolidone. The element is developable using water alone as a solvent.

Abstract: A process for the production of a thermo-developable type diazo copying material which comprises the steps of adding a heat fusible color assistant having a melting point of 50.degree. to 150.degree. C. to at least one selected from the group consisting of (a) an aqueous dispersion A containing a diazonium salt and fine particles of a hydrophobic resin consisting of a polymer of vinyl chloride, vinylidene chloride, styrene, acrylic ester, mechacrylic ester or olefin or a copolymer containing at least one member of aforesaid monomers as the constitution unit or a mixture of said polymer with said copolymer and (b) an aqueous solution or dispersion B containing coupler; then applying these aqueous dispersion A and aqueous solution or dispersion B onto a substrate in the order named; and drying same.

Abstract: A developer composition of an alkaline aqueous solution containing a reducing inorganic salt, typically an alkali metal salt of sulfurous acid such as sodium sulfite, is found to be applicable for development of a lithographic printing plate material containing a photosensitive o-quinonediazide compound and an organic polymer, with reduced deterioration in developing capacity caused by the air and enhanced stability with lapse of time. In particular, a developer composition composed of an alkaline aqueous solution of pH 11 or higher containing a water-soluble sulfurous acid salt is effective for developing both of a lithographic printing plate material having a nega-type photosensitive layer containing a photosensitive diazo compound and an organic polymer, and a lithographic printing plate material having a posi-type photosensitive layer containing an o-quinonediazide compound and an organic polymer.

Abstract: A two-component diazotype material, composed of a support and a light-sensitive layer which is applied thereto and contains a polymeric binder, a diazonium salt, a coupler, an acid stabilizer and conventional additives, wherein the support is a biaxially oriented polyester film and the polymeric binder comprises a mixture of about 10-60 percent by weight of a polymer or copolymer of vinyl acetate, for example, a copolymer of vinyl acetate and crotonic acid, and about 40-90 percent by weight of a cellulose ester, such as cellulose acetopropionate, cellulose acetobutyrate, cellulose propionate or cellulose butyrate.

Abstract: Presensitized lithographic printing plates, having extended press run life, are provided by electrolytically passing a current through the light-sensitive material in the prefabricated plate. Press runs of up to sixty percent longer than expected are possible with plates which are so treated.