Abstract: A reaction product of a mixture of components suitable for molding into shaped desiccant particles, wherein the mixture includes: a. a porous siliceous material, b. hygroscopic salt, c. polyvinyl alcohol (PVA) with a degree of hydrolysis between 82 and 95 mol % and a viscosity between 12 and 40 mPa·s, as determined on an aqueous solution of 4% PVA at 20° C. according to DIN53015, d. water, e. optionally, an OH-containing polymer, different from PVA, wherein the weight ratio between hygroscopic salt and the porous siliceous material is chosen between 0.1:1 and 0.9:1 and wherein the weight ratio between hygroscopic salt and PVA is chosen between 1:1 and 5:1.

Abstract: A passivation composition and use of the composition in a method of forming a conductive pattern are provided. The passivation composition includes an oxidizing agent, an inorganic base with a general formula M(OH)n and a solvent, wherein M is a metal ion and n is the valence number of the metal ion. The method includes the following steps: (a) forming a polymer conductive layer on a substrate, wherein the polymer conductive layer is consisting of a first area and a second area. The first area is corresponding to a conductive area to be formed; and (b) passivating the second area by using the passivation composition to reduce the conductivity of the second area and form the conductive pattern on the substrate.

Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer, which is located overlying the electroconductive substrate and which includes a charge generation material, a charge transport material having no radical polymerizability, a binder resin having no radical polymerizability, and a crosslinked polymer including a unit obtained from a first radically polymerizable monomer having three or more functional groups and no charge transport structure and a unit obtained from a second radically polymerizable monomer having a charge transport structure; and an outermost layer, which is located on the photosensitive layer and which includes a crosslinked polymer including a unit obtained from a third radically polymerizable monomer having three or more functional groups and no charge transport structure and a unit obtained from a fourth radically polymerizable monomer having a charge transport structure. An image forming method and apparatus, and a process cartridge using the photoreceptor.

Abstract: An electrostatic latent image bearing member is provided including a substrate and a photosensitive layer located overlying the substrate, wherein the outermost layer of the electrostatic latent image bearing member includes a cross-linked resin formed from a cross-linking reaction between a charge transport polyol having a specific formula and an isocyanate compound; and the use of the electrostatic latent image bearing member in an image forming apparatus, a process cartridge, and an image forming method.

Abstract: A photoreceptor is provided having an electroconductive substrate and a photosensitive layer located overlying the electroconductive substrate, wherein an outermost layer of the photoreceptor contains a binder resin, wherein the binder resin solution satisfies the following relationship 2?(T0?T400)/C wherein T0 represents a initial transmittance (%) at 400 nm of the binder resin solution; T400 represents a transmittance (%) at 400 nm of the binder resin solution which has been allowed to settle for 400 hours under conditions of 23° C. and 40% RH; and C represents the concentration of the binder resin solution; and an image forming method, an image forming apparatus and a process cartridge including the photoreceptor.

Abstract: An electrophotographic photoreceptor having an organic photosensitive layer at the surface layer is provided which can improve the wear resistance, durability and operation stability of the surface layer and can form images with no injury and unevenness in the density for a long period of time. The electrophotographic photoreceptor includes a conductive substrate, an undercoat layer, and a photosensitive layer having a charge generating layer and a charge transporting layer. In the photoreceptor, the photosensitive layer has a creep value CI? of 2.70% or more and an elastic ratio ?HU of 47% or more in a case where an indentation maximum load of 5 mN is loaded on the surface under a circumstance at a temperature of 25° C. and at a relatively humidity of 50%.

Abstract: A positive planographic printing plate precursor includes a support having disposed thereon a lower thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound and an upper thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound, with alkali-solubility increasing under heat, wherein (i) both the upper thermosensitive layer and the lower thermosensitive layer contain an IR absorbing dye, with the ratio of the IR absorbing dye concentration in the upper thermosensitive layer to the IR absorbing dye concentration in the lower thermosensitive layer is 1.6 to 10.0, and/or (ii) the upper thermosensitive layer and the lower thermosensitive layer contain different IR absorbing dyes, and/or (iii) at least one of the upper thermosensitive layer and the lower thermosensitive layer contains an IR absorbent having, in one molecule, at least two chromophoric groups that absorb IR light, with the chromophoric groups bonding to each other via a covalent bond.

Abstract: A positive planographic printing plate precursor includes a support having disposed thereon a lower thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound and an upper thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound, with alkali-solubility increasing under heat, wherein (i) both the upper thermosensitive layer and the lower thermosensitive layer contain an IR absorbing dye, with the ratio of the IR absorbing dye concentration in the upper thermosensitive layer to the IR absorbing dye concentration in the lower thermosensitive layer is 1.6 to 10.0, and/or (ii) the upper thermosensitive layer and the lower thermosensitive layer contain different IR absorbing dyes, and/or (iii) at least one of the upper thermosensitive layer and the lower thermosensitive layer contains an IR absorbent having, in one molecule, at least two chromophoric groups that absorb IR light, with the chromophoric groups bonding to each other via a covalent bond.

Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 ?m.

Abstract: Infrared absorbing compounds in which both the anion and the cation absorb infrared radiation, imageable elements that contain these compounds, and methods for forming images using the imageable elements are disclosed.

Abstract: A presensitized plate for preparing a lithographic printing plate comprises a substrate provided thereon with a light-sensitive layer containing a fluoro-aliphatic group-containing copolymer prepared by copolymerizing at least (A) an addition polymerizable monomer having, on a side chain, a fluoro-aliphatic group in which hydrogen atoms are replaced with fluorine atoms and (B) a (meth)acrylate having an ester chain represented by a specific general formula. The use of the foregoing specific fluorine atom-containing polymer permits the formation of a light-sensitive layer having uniform surface condition without causing abnormality in the surface quality due to the foaming phenomenon observed during the production and also permits the production of a positive light-sensitive resin composition having excellent solubility and dispersibility in a developer.

Abstract: The present invention provides a negative-working presensitized plate useful for preparing a lithographic printing plate having a negative-working photosensitive layer on an aluminum substrate, which comprises an intermediate layer comprising a compound having at least one diazonium group and molecular weight of 1000 or less formed between said photosensitive layer and said aluminum substrate. The lithographic printing plate prepared from the negative-working presensitized plate of the present invention shows excellent adhesiveness between a substrate and a photosensitive layer and does not cause contamination in non-imaging areas during printing operation, while maintaining high sensitivity, sensitive range and performance of the photosensitive layer.

Abstract: A heat-sensitive lithographic printing plate precursor is disclosed, which comprises an aluminum support having provided thereon an ink-receptive layer and a hydrophilic layer containing a colloidal particle oxide or hydroxide of at least one element selected from the group consisting of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals, wherein at least one layer of the ink-receptive layer and the hydrophilic layer contains a compound capable of converting light into heat, the aluminum support has an anodic oxide film in an amount of 2 g/m2 or more, and the anodic oxide film has been subjected to sealing treatment at a sealing rate of 50% or more.

Abstract: A photosensitive lithographic printing plate has an aluminum support anodized and treated with an aqueous solution of polyvinylphosphonic acid adjusted to pH 1.5 or below to ensure no deterioration of impression capacity and prevention of the water-ink balance scum in the lithographic printing plate made therefrom even when a cleaner is used in the course of printing.

Abstract: Disclosed is a heat-sensitive recording material comprising a support comprised of a substrate and a thermoplastic resin layer formed thereon, and a heat-sensitive recording layer disposed on the support and containing a diazonium salt compound capable of being decomposed by ultraviolet light, wherein the thermoplastic resin layer is formed by melt extrusion and wherein the thermoplastic resin layer contains a fluorescent brightening agent and a white pigment. In the heat-sensitive recording material, the fluorescent brightening agent is preferably a compound represented by the following structural formula (I):Structural Formula (I) ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represent a hydrogen atom, or a substituent group or a substituent atom.

Abstract: Proposed is a novel undercoating composition to form an undercoating layer interposed between the surface of a substrate and a photoresist layer with an object to decrease the adverse influences by the reflection of light on the substrate surface in the pattern-wise exposure of the photo-resist layer to ultraviolet light without the undesirable phenomena of intermixing between layers and notching along with a large selectivity ratio in the etching rates between the patterned resist layer and the undercoating layer in a dry-etching treatment. The undercoating composition comprises (A) an ultraviolet absorber which is a benzophenone compound or an aromatic azomethine compound each having at least one unsubstituted or alkyl-substituted amino group on the aryl groups and (B) a crosslinking agent which is preferably a melamine compound having at least two methylol groups or alkoxymethyl groups bonded to the nitrogen atoms in a molecule in a weight proportion (A):(B) in the range from 1:1 to 1:10.

Abstract: A method for directly imaging a lithographic printing surface using infrared radiation without the requirement of pre- or post-UV-light exposure, or heat treatment employs a printing plate which contains a support with a hydrophilic surface overcoated with an imaging layer. The imaging layer contains at least one polymer having bonded pendent groups which are hydroxy, carboxylic acid, tert-butyl-oxycarbonyl, sulfonamide, amide, nitrile, urea, or combinations thereof; as well as an infrared absorbing compound. The imaging layer may contain a second polymer which has bonded pendent groups which are 1,2-napthoquinone diazide, hydroxy, carboxylic acid, sulfonamide, hydroxymethyl amide, alkoxymethyl amide, nitrile, maleimide, urea, or combinations thereof. The imaging layer may also contain a visible absorption dye, a solubility inhibiting agent, or both.

Abstract: A composition and methods for the use and manufacture thereof are provided for a polymeric dye. The composition comprises one or more aminoaromatic chromophores in conjunction with polymers having an anhydride group or the reaction products thereof. The composition is particularly useful as an underlaying antireflective coating with microlithographic photoresists for the absorbtion of near or deep ultraviolet radiation.

Abstract: According to the present invention there is provided an imaging element for making a lithographic printing plate comprising on a support having a hydrophilic surface a photosensitive layer and a thermosensitive layer, said thermosensitive layer being opaque to light for which said photosensitive layer has spectral sensitivity and said thermosensitive layer being capable of rendered transparent upon exposure to laser light characterised in that an intermediate layer being soluble or swellable in an aqueous medium is provided between said photosensitive layer and said thermosensitive layer.

Abstract: A composition and methods for the use and manufacture thereof are provided for a polymeric dye. The composition comprises one or more aminoaromatic chromophores in conjunction with polymers having an anhydride group or the reaction products thereof. The composition is particularly useful as an underlaying antireflective coating with microlithographic photoresists for the absorbtion of near or deep ultraviolet radiation.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having on a plastic film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said photosensitive layer.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having of a flexible film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and wiping it with a disposable absorbing tissue moistened with water or fountain solution.

Abstract: The present invention provides an imaging element comprising on a hydrophilic base a light-sensitive layer containing polyvinyl alcohol hydrolyzed to at least an extent of 95% by weight, a cationic surfactant and a diazo resin and/or a diazonium salt characterized in that the light-sensitive layer comprises metal-free phthalocyanine.The present invention also provides a method for obtaining an imaging element as defined in any of the claims 1 to 6 bypreparing a dispersion of metal-free phthalocyanine in water in the presence of a cationic surfactant in an amount ranging from 0.24 g/l to 24 g/l;preparing a light-sensitive composition by mixing said dispersion, polyvinyl alcohol hydrolyzed to at least an extent of 95% by weight and a diazo resin and/or a diazonium salt andcoating said light-sensitive composition on a hydrophilic base, characterized in that said dispersion comprises polyvinyl alcohol hydrolyzed to at least an extent of 95% by weight in an amount ranging from 4.0 g/l to 200 g/l.

Abstract: The present invention provides an imaging element comprising on a support a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and having been hardened with a hydrolysed tetraalkyl orthosilicate and a light sensitive layer containing a diazo resin and/or a diazonium salt characterized in that the light sensitive layer comprises at least one diazo resin or diazonium salt containing or being a diazonium salt of p-aminodiphenylamine containing as substituent an alkyl or alkoxy group and the weight percentage of said diazonium salt(s) and/or diazo resin(s) containing or being a diazonium salt of p-aminodiphenylamine containing as substituent an alkyl or alkoxy group versus the total amount of diazo resin and/or diazonium salt ranges from 22 to 40%.

Abstract: The present invention provides an imaging element comprising on a support in the order given a coated composition of at least two hydrophilic layers being in water permeable contact with each other and each containing a hydrophilic (co)polymer or (co)polymer mixture and having been hardened with a hydrolyzed tetraalkyl orthosilicate and a light sensitive layer containing a diazo resin or a diazonium salt characterized in that the ratio by weight in the top layer of said package of said hydrophilic (co)polymer or (co)polymer mixture versus said hydrolyzed tetraalkyl orthosilicate (expressed as silicon dioxide) is at least 1.1 and the ratio by weight in an underlying layer of said package of said hydrophilic (co)polymer or (co)polymer mixture versus said hydrolyzed tetraalkyl orthosilicate (expressed as silicon dioxide) is not higher than 0.9.

Abstract: A method of determining an optimum condition of an anti-reflective layer upon forming a resist pattern by exposure with a monochromatic light, forms the anti-reflective layer with these conditions and forms a resist pattern using a novel anti-reflective layer.

Abstract: The present invention provides a lithographic base comprising on a hydrophobic support a packet of subbing layers contiguous to a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolysed tetraalkyl orthosilicate crosslinking agent characterized in that said packet of subbing layers contains as undermost layer a layer comprising, a polymer latex having hydrophilic functionality and as uppermost layer a layer comprising a hydrophilic binder and silica in a weight ratio of the hydrophilic binder to silica of less than 1.

Abstract: The present invention provides an imaging element comprising on a hydrophilic support a light sensitive layer containing a diazo resin or a diazonium salt characterized in that said light sensitive layer contains pullulan. The obtained imaging element shows an improved storage stability.

Abstract: A method of determining an optimum condition of an anti-reflective layer upon forming a resist pattern by exposure with a monochromatic light, a method of forming the anti-reflective layer therewith and a method of forming a resist pattern using a novel anti-reflective layer obtained therewith. The optimum condition of the anti-reflective layer is determined and the anti-reflective layer is formed by the methods described below. Further, an optimal anti-reflective layer is obtained by the method which is used for forming the resist pattern.

Abstract: According to the present invention the storage stability of a diazo based imaging element can be improved by controlling the amount of free water in the imaging element. Thus the present invention provides an imaging element comprising on a support a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and having been hardened with a hydrolyzed tetraalkyl orthosilicate and a light sensitive layer containing a diazo resin or a diazonium salt characterized in that the total amount of free water in said imaging element satisfies the following formula (I):FW (g/m.sup.2).ltoreq.0.0043 * WS (g/m.sup.2)+0.46 (g/m.sup.2) (I)wherein FW represents the amount of free water and WS represents the weight of the support of the imaging element.

Abstract: The present invention provides an imaging element comprising on a hydrophilic support a light sensitive layer containing a diazo resin or a diazonium salt characterized in that said light sensitive layer contains pullulan. The obtained imaging element shows an improved storage stability.

Abstract: A thermal development diazo copying material is composed of a support, and a photosensitive layer formed thereon, which includes a diazo compound, a coupler, an alkali-soluble resin, and a sensitizer, with only the coupler being contained in microcapsules made of the alkali-soluble resin.

Abstract: A method of determining an optimum condition of an anti-reflective layer upon forming a resist pattern by exposure with a monochromatic light, a method of forming the anti-reflective layer therewith and a method of forming a resist pattern using a novel anti-reflective layer obtained therewith. The optimum condition of the anti-reflective layer is determined and the anti-reflective layer is formed by the methods described below. Further, an optimal anti-reflective layer is obtained by the method which is used for forming the resist pattern.

Abstract: A method of determining an optimum condition of an anti-reflective layer upon forming a resist pattern by exposure with a monochromatic light, forms the anti-reflective layer with these conditions and forms a resist pattern using a novel anti-reflective layer.

Abstract: The present invention provides a lithographic base comprising on a hydrophobic support a subbing layer and a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent characterized in that said subbing layer contains a hydrophilic binder and silica, the surface area of the silica being at least 300 m.sup.2 per gram.

Abstract: The present invention provides a lithographic base comprising on a hydrophobic support a subbing layer contiguous to a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent characterized in that said subbing layer contains a hydrophilic binder and silica and is applied at a solids content of more than 200 mg per m.sup.2 but less than 750 mg per m.sup.2.

Abstract: The present invention provides an imaging element comprising on a support in the order given, a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent and a light sensitive layer containing a diazo resin or a diazonium salt characterized in that an intermediate hydrophilic layer containing an organic compound having one or more cationic groups is provided between said hydrophilic layer and said light-sensitive layer. There is further provided a method for making such an imaging element and a method for making a lithographic printing plate therewith.

Abstract: Improved lithographic printing plates are comprised of an aluminum support, a hydrophilic barrier layer comprised of a copolymer of about 40 to about 90 mole percent vinylphosphonic acid and about 10 to about 60 mole percent acrylamide overlying said support, and an image-forming layer capable of providing a lithographic printing surface overlying said barrier layer.

Abstract: Disclosed is a light-sensitive litho printing plate requiring no dampening water having a primer layer, a light-sensitive layer and a silicone rubber layer in this order on a support, characterized in that the above primer layer contains (1) an ethylenic unsaturated compound having a polymerizable unsaturated group and (2) a photopolymerization initiator, and has a tensile strength of 10 Kg/cm.sup.2 or more and a Vickers hardness of 70 or less.

Abstract: A light-sensitive transfer sheet is disclosed, which comprises a support having provided thereon a peeling layer comprising an alcohol-soluble polyamide, an alkali-soluble organic polymer and a basic compound, and a color material-incorporated light-sensitive resin layer or a color material layer and a light-sensitive resin layer, in that order.

Abstract: An aluminum alloy substrate for presensitized plates for use in making lithographic printing plates comprises an aluminum alloy plate composed of not less than 0.05% by weight and less than 0.5% by weight of Si; 0.2 to 0.7% by weight of Fe; 0.3 to 1.5% by weight of Mn; less than 0.5% by weight of Cu; and the balance of aluminum and unavoidable impurities, the surface of the aluminum alloy plate being subjected to electrolytic graining treatment. The aluminum alloy substrates for PS plates are favorable for appropriate electrolytic graining treatment and show good printing properties and sufficient strength suitable for high-speed printing operation.

Abstract: The present invention relates to an aluminum support for a lithographic plate, whose surface is electrochemically roughened and has the following conditions:a) an arithmetic mean of the pit diameters of the electrolytically etched support is 4 .mu.m or less,b) a difference between an arithmetic mean (D.sub.L) of the maximum pit diameter of the support in the rolling direction and an arithmetic mean (D.sub.LT) of the maximum pit diameter of the support in the direction perpendicular to the rolling direction is larger than 10% of the maximum pit diameter (a larger one of D.sub.L and D.sub.LT),c) the number of pits detected with a surface roughness tester having a profilometer using a stylus having a tip radius of 1 .mu.m is at last 200/mm, andd) an average centerline roughness is 0.2 .mu.m to 1.0 .mu.m.According to the present invention, a lithographic plate having the aluminum support is excellent in both of a printing durability and a stain proofness.

Abstract: A photosensitive recording material comprising (a) a substrate having a hydrophilic surface, (b) an undercoating layer comprising at least one compound having at least one functional group selected from the group consisting of thiol, thioether and disulfide groups, and (c) a photosensitive layer comprising at least one diazonium compound and a high molecular weight binder compound which is insoluble in water and soluble in aqueous alkaline solution. The resulting developed plate yields no background contamination in printing process.

Abstract: A presensitized printing plate for waterless lithographic printing is described which is composed of a substrate, a printing ink-repellent crosslinked silicone elastomer coating situated thereon, an intermediate coating of amorphous silicic acid or of an exposed coating of a photosensitive organic halogen compound and a radiation-sensitive coating. The intermediate coating effects a better adhesion of the photosensitive coating to the silicone coating and, consequently, a better resistance to developer and better print run of the plate.

Abstract: A light-sensitive composition comprises a diazo resin, a polymeric binder, and at least one compound having at least one structural unit selected from the group consisting of ureido bond, thioureido bond, urethane bond and thiourethane bond. The light-sensitive composition can suitably be used for preparing a presensitized plate for use in making lithographic printing plates and is excellent in developability with an aqueous alkaline developer.

Abstract: Photopolymeric printing plates wherein an electrochemically etched, anodized and silicated aluminum plate has a plurality of coatings applied thereon and wherein at least one of the coatings include a solvent soluble diazo therein.

Abstract: A photosensitive lithographic plate is suitable for use in making a water-less lithographic plate which does not require dampening water. The photosensitive lithographic plate has a primer layer containing a hardened gelatin, a photosensitive layer and a silicone rubber layer. The silicone rubber layer and the photosensitive layer are imagewise removed as a result of the imagewise exposure and development so as to expose portions of the primer layer corresponding to an image. The exposed gelatin-containing plate is securely adhered to the substrate and is easily dyeable for examination of the formed image.

Abstract: In a process for producing a support for a lithographic printing plate, at least one surface of an aluminum sheet is subjected to roughening treatment and subsequently to anodic oxidation treatment at a current density of at least 1 A/dm.sup.2 in an electrolytic solution containing 0.1 to 5% by weight of an alkaline electrolyte. Even if scratches are formed on non-image areas of a printing plate prepared from the support according to the invention, such scratches cause less stains on a printed matter.

Abstract: A coated lithographic printing plate comprises a grained, anodized aluminum substrate and coating thereon comprising a diazo resin in admixture with particulate energy absorbing material that will absorb incident radiation and re-radiate it as radiation that will change the diazo resin coating which is imageable with a Crosfield Datrax 760 YAG laser plate maker producing incident radiation of 1/06 microns. The topography of the substrate and the particulate material in the coating trap and convert a substantial portion of the incident laser radiation which passes through the coating without substantially affecting same into radiation that will change the coating.

Abstract: The invention relates to new diazotype materials of which the sensitive layer contains, as a base generator, a compound comprising a basic part and an acid part, the acid part being a 2-carboxycarboxamide group and the basic part consisting of an alkali metal cation or alkaline earth metal cation or a tetraalkylammonium cation.These diazotype materials develop rapidly and possess an excellent resistance to ageing.