A cosmetic composition comprising titanium oxide coated with one or both of silica and alumina or zinc oxide coated with one or both of silica and alumina, and a thickening polymer having a carboxyl group in the side chain, preferably a carboxyvinyl polymer, wherein when 10% by mass of silica- and/or alumina-coated titanium oxide or silica- and/or alumina-coated zinc oxide is dispersed in an aqueous solution containing 0.133% by mass of a carboxyvinyl polymer, the viscosity after the passing of 100 hours is 50% or more of the initial viscosity. A cosmetic composition comprising titanium oxide coated with one or both silica and alumina or zinc oxide coated with one or both of silica and alumina, and a thickening polymer having a carboxyl group in the side chain of the invention, can maintain emulsion stability by thickening of polymer for a long period of time and can be widely and suitably used for ultraviolet shielding cosmetic materials or the like having preparation form stability.

The present invention relates to a cosmetic composition, particularly a cosmetic composition having an ultraviolet shielding ability. More specifically, the present invention relates to a titanium oxide- or zinc oxide-containing cosmetic composition capable of maintaining the emulsion stability for a long period of time by virtue of thickening of a polymer having a carboxyl group in the side chain.
In cosmetic compositions having an ultraviolet shielding ability, an organic compound-based ultraviolet absorber or an inorganic compound-based ultraviolet shielding agent is blended.
The organic compound-based ultraviolet absorber has a problem of instability due to its decomposition property and therefore, an inorganic compound-based ultraviolet shielding agent is recently used in many cases. In particular, titanium oxide or zinc oxide is generally used.
The preparation form of the cosmetic composition having an ultraviolet shielding ability includes various shapes such as solubilized form, emulsion form (W/O type, O/W type, W/O/W), powder form and gel form. In the case of an O/W form or gel form, a thickening polymer having a carboxyl group in the side chain is preferably used as a thickener so as to increase stability of the preparation form.
Specific examples of the thickening polymer having a carboxyl group in the side chain include carboxyvinyl polymer, carboxymethyl cellulose, carboxymethyl starch, poly(sodium acrylate), alginic acid propylene glycol ester and alginic acid salt. Among these, carboxyvinyl polymer is used widely.
The carboxyvinyl polymer is characterized and advantageous in that high thickening stability can be obtained with a low concentration, that reproducibility which cannot be realized by natural polymers can be attained, that the temperature stability and microorganism resistance are high, that the pH and viscosity which can be used have a wide range, and that good use property is provided at the application to skin. Therefore, the carboxyvinyl polymer is being widely used in cosmetic materials. For example, JP-A-08-505624 (WO94/15580) discloses an oil-in-water emulsion composition comprising a fine pigment particle having the surface treated to be hydrophobic, and a carboxylic acid polymer thickener. JP-A-09-151110 discloses alkyl (meth)acrylate polymer as a thickener for a liquid cosmetic containing an inorganic powder such as titanium oxide.
In the case where the carboxyvinyl polymer is used in combination with titanium oxide or zinc oxide in an ultraviolet shielding cosmetic composition, the titanium oxide or zinc oxide used in combination for enhancing the ultraviolet shielding ability is likely formed into microfine particles and the resulting increase in the surface activity of titanium oxide or zinc oxide (catalytic action) causes deterioration of carboxyvinyl polymer. The surface activity can be suppressed to a certain extent by surface treatment with silica, alumina or the like, however, photocatalytic deterioration of carboxyvinyl polymer cannot be satisfactorily suppressed by conventional surface treatments. Accordingly, reduction of viscosity takes place in the gel-form preparation and separation or creaming in the emulsion-form preparation.
The carboxyvinyl polymer deteriorates in the preparation form stability due to the effect of metal ion, because the hydration degree of polymer is reduced by the reaction between metal ion and carboxyl group and therefore, the viscosity decreases. In conventional production of surface-treated titanium oxide or zinc oxide, the surface treatment uses precipitation of inorganic metal oxide from sodium silicate or sodium aluminate and since sodium ion remains, polyvalent ion such as calcium, magnesium and iron is contained as impurities in many cases.
Furthermore, conventional surface-treated zinc oxide is insufficient in the film formation and therefore, zinc ion is eluted accompanying the dissolution of zinc oxide. As a result, when conventional surface-treated titanium oxide or zinc oxide is used in combination with carboxyvinyl polymer, the viscosity decreases along the elution of ion and the preparation form stability disadvantageously deteriorates.
The object of the present invention is to provide an ultraviolet shielding cosmetic composition containing titanium oxide or zinc oxide, which can maintain the preparation (emulsion or gel) form stability for a long period of time by the thickening of carboxyvinyl polymer.
As a result of extensive investigations to attain the above-described object, the present inventors have found that a cosmetic composition having desired properties can be obtained when silica-coated titanium oxide or zinc oxide coated with a certain dense silica film is blended in combination with a polymer having a carboxyl group in the side chain. The present invention has been accomplished based on this finding.
More specifically, the present invention relates to the following cosmetic composition, silica-coated titanium oxide and/or silica-coated zinc oxide used for the cosmetic composition, and method for producing the same.
[1] A cosmetic composition comprising titanium oxide coated with one or both of silica and alumina or zinc oxide coated with one or both of silica and alumina, and a thickening polymer having a carboxyl group in the side chain.
[2] The cosmetic composition as described in [1] above, wherein the thickening polymer having a carboxyl group in the side chain is at least one polymer selected from a group consisting of carboxyvinyl polymer, carboxymethyl cellulose, carboxymethyl starch, poly(sodium acrylate), alginic acid propylene glycol ester and alginic acid salt.
[3] The cosmetic composition as described in [2] above, wherein the thickening polymer having a carboxyl group in the side chain is carboxyvinyl polymer.
[4] The cosmetic composition as described in [3] above, wherein when titanium oxide coated with one or both of silica and alumina or zinc oxide coated with one or both of silica and alumina is dispersed by 10% by mass in an aqueous solution containing 0.133% by mass of a carboxyvinyl polymer, the viscosity after the passing of 100 hours is 50% or more of the initial viscosity.
[5] The cosmetic composition as described in [4] above, wherein when titanium oxide coated with one or both of silica and alumina is dispersed by 10* by mass in an aqueous solution containing 0.133% by mass of a carboxyvinyl polymer, the viscosity after the passing of 100 hours is 70% or more of the initial viscosity.
[6] The cosmetic composition as described in [4] above, wherein when zinc oxide coated with one or both of silica and alumina is dispersed by 10% by mass in an aqueous solution containing 0.133% by mass of a carboxyvinyl polymer, the viscosity after the passing of 100 hours is 60% or more of the initial viscosity.
[7] The cosmetic composition as described in [1] above, which comprises silica-coated titanium oxide or silica-coated zinc oxide coated with a dense silica film having a film thickness of 0.1 to 100 nm and a refractive index of 1.435 or more.
[8] The cosmetic composition as described in [11] above, wherein the photocatalytic activity of the silica-coated titanium oxide or silica-coated zinc oxide determined by the tetralin auto-oxidation method is 60 Pa/min or less.
[9] The cosmetic composition as described in [1] above, wherein the silica-coated titanium oxide or silica-coated zinc oxide has a primary particle size of 5 to 200 nm.
[10] The cosmetic composition as described in [1] above, wherein the ratio I of absorption peak intensity at 1,150 to 1,250 cmxe2x88x921 to absorption peak intensity at 1,000 to 1,100 cmxe2x88x921 on the infrared absorption spectrum (I=I1/I2, wherein I1, is absorption peak intensity at 1,150 to 1,250 cmxe2x88x921 and I2 is absorption peak intensity at 1,000 to 1,100 cmxe2x88x921) is 0.2 or more.
[11] The cosmetic composition as described in [1] above, wherein the dye discoloration rate (xcex94ABS490/hr) of the silica-coated titanium oxide or silica-coated zinc oxide measured by the Sunset Yellow method is 0.1 or less.
[12] The cosmetic composition as described in [1] above, wherein the organic ultraviolet absorber decomposition rate (xcex94ABS340/hr) of the silica-coated titanium oxide or silica-coated zinc oxide measured by the Parsol method is 0.01 or less.
[13] The cosmetic composition as described in [1] above, wherein silica-coated titanium oxide or silica-coated zinc oxide is blended in an amount of 0.1 to 50% by mass based on the entire amount of cosmetic composition.
[14] A silica-coated titanium oxide or silica-coated zinc oxide used for the cosmetic composition described in [1] above, which is obtained by coating titanium oxide or zinc oxide with a silica film-forming composition containing (1) a silicic acid having neither an organic group nor a halogen, or a precursor capable of producing the silicic acid, (2) water, (3) an alkali and (4) an organic solvent.
[15] The silica-coated titanium oxide or silica-coated zinc oxide as described in [14] above, which is obtained by contacting titanium oxide or zinc oxide with the silica film-forming composition having a water/organic solvent ratio (volume) of 0.1 to 10 and a silicic acid concentration of 0.0001 to 5 mol/liter to selectively deposit silica on the surface of titanium oxide or zinc oxide.
[16] A method for producing a silica-coated titanium oxide or silica-coated zinc oxide used for the cosmetic composition described in any one of [1] to [13] above, comprising coating titanium oxide or zinc oxide with a silica film-forming composition containing (1) a silicic acid having neither an organic group nor a halogen or a precursor capable of producing the silicic acid, (2) water, (3) an alkali and (4) an organic solvent.
[17] The method for producing the silica-coated titanium oxide or silica-coated zinc oxide as described in [16] above, comprising contacting titanium oxide or zinc oxide with the silica film-forming composition having a water/organic solvent ratio (volume) of 0.1 to 10 and a silicic acid concentration of 0.0001 to 5 mol/liter to selectively deposit silica on the surface of titanium oxide or zinc oxide.
The mode for carrying out the invention is described in detail below, however, the present invention is not limited thereto.
The present invention is described by taking silica-coated titanium oxide or silica-coated zinc oxide as an example out of titanium oxide and zinc oxide coated with silica, alumina or both silica and alumina which can be used in the present invention.
In the cosmetic composition of the present invention, a silica-coated titanium oxide or a silica-coated zinc oxide may be suitably used, which is obtained by a method of contacting titanium oxide powder or zinc oxide powder with a silica film-forming composition comprising silicic acid, water, an alkali and an organic solvent and having a water/organic solvent ratio by volume of 0.1 to 10 and a silicon concentration of 0.0001 to 5 mol/liter to selectively deposit dense silica on the surface of titanium oxide powder or zinc oxide powder.
In the silica-coated titanium oxide or silica-coated zinc oxide coated with a dense silica film, which can be more suitably used in the cosmetic composition of the present invention, the ratio I of absorption peak intensity at 1.150 to 1,250 cmxe2x88x921 to absorption peak intensity at 1,000 to 1,100 cmxe2x88x921 on the infrared absorption spectrum (I=I1/I2, wherein I1, is absorption peak intensity at 1,150 to 1,250 cmxe2x88x921 and I2 is absorption peak intensity at 1,000 to 1,100 cmxe2x88x921) is 0.2 or more and the refractive index is 1.435 or more.
The silicic acid for use in the silica film-forming composition indicates orthosilicic acid or a polymer thereof having no organic group and halogen such as metasilicic acid, mesosilicic acid, mesotrisilicic acid and mesotetrasilicic acid, which are described, for example, in the paragraph xe2x80x9cSilicic Acid xe2x80x9d of Encyclopaedia Chimica, 7th imp., Kyoritsu Shuppan (Mar. 15, 1969).
The composition containing silicic acid can be obtained by adding water, an alkali and an organic solvent to tetraalkoxysilane (Si(OR)4, wherein R is a hydrocarbon group (specific examples thereof include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxy silane and tetra-n-butoxy silane)), stirring the mixture and thereby allowing a hydrolysis reaction to proceed. This method is practical and preferred because of easiness in handling or operation. Among those materials, tetraethoxysilane is preferred.
The composition containing silicic acid can also be obtained by a method of hydrolyzing silane tetrahalogenide by adding thereto water, an alkali and an organic solvent, a method of adding an alkali and an organic solvent to water glass, or a method of treating water glass with a cationic exchange resin and adding thereto an alkali and an organic solvent. Tetraalkoxysilane, silane tetrahalogenide or water glass used as the starting material of silicic acid is not particularly limited and one used in industry or widely known as a reagent may be used, however, a higher purity material is suitable. The silica film-forming composition for use in the present invention may contain an unreacted material of the above-described starting material for silicic acid.
The amount of silicic acid is not particularly limited but is preferably from 0.0001 to 5.0 mol/liter, in terms of the silicon concentration. If the silicon concentration is less than 0.0001 mol/liter, the silica film is formed at a very low rate and this is not practical, whereas if it exceeds 5 mol/liter, the coating is not formed and silica particles may be produced in the composition.
The silicon concentration may be calculated from the amount of, for example, tetraalkoxysilane added but can also be measured by atomic absorption spectrochemical analysis of the composition. The measurement may be performed using a spectrum at a wavelength of 251.6 nm for the analytical line and acetylene/nitrous oxide for the frame.
The water used in the silica film-forming composition is not particularly limited but is preferably water from which particles are removed by filtration or the like. If the water contains particles, the particles maybe disadvantageously mixed into the product as an impurity.
The water is preferably used in an amount of 0.1 to 10 in terms of the water/organic solvent ratio by volume. If the water/organic solvent ratio by volume exceeds or is less than this range, the coating may not be formed or the film formation rate may extremely decreases. The water/organic solvent ratio by volume is preferably from 0.1 to 5 and more preferably from 0.1 to 0.5. Insofar as the water/organic solvent ratio by volume is from 0.1 to 5, the kind of alkali used is not limited. In the case where the water/organic solvent ratio by volume is 5 or more, the coating is preferably formed using an alkali metal-free alkali such as ammonia, ammonium hydrogencarbonate and ammonium carbonate.
The alkali used in the silica film-forming composition for use in the present invention is not particularly limited but examples of the alkali which can be used include inorganic alkalis such as ammonia, sodium hydroxide and potassium hydroxide; inorganic alkali salts such as ammonium carbonate, ammonium hydrogencarbonate, sodium carbonate and sodium hydrogencarbonate; organic alkalis such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, pyridine, aniline, choline, tetramethylammonium hydroxide and guanidine; and alkaline salts of organic acid, such as ammonium formate, ammonium acetate, monomethylamine formate, dimethylamine acetate, pyridine lactate, guanidinoacetic acid and aniline acetate.
Among these, in view of control of the reaction rate, ammonia, ammonium carbonate, ammonium hydrogencarbonate, ammonium formate, ammonium acetate, sodium carbonate and sodium hydrogencarbonate are preferred. The above-described alkalis for use in the silica film-forming composition may be used individually or in combination of two or more thereof.
The purity of alkali for use in the present invention is not particularly limited and an alkali used in industry or widely known as a reagent may be used, but a higher purity alkali is preferred.
The silica film-forming rate may be effectively increased by elevating the temperature at the film formation. In this case, an alkali and an organic solvent which are not easily volatilized or decomposed at the film formation temperature are preferably used.
With respect to the amount of alkali used for film formation in the present invention, for example, in the case of sodium carbonate, the coating may be formed by adding the alkali in a trace amount of about 0.002 mol/liter but the alkali may also be added in a large amount of about 1 mol/liter. However, if a solid alkali is added in excess of solubility, the alkali is disadvantageously mixed into the metal oxide powder as an impurity.
By using an alkali not containing an alkali metal as a main component, silica-coated metal oxide powder having a small alkali metal content can be prepared. In this case, ammonia, ammonium carbonate and ammonium hydrogencarbonate are preferred in view of the film formation rate and easiness in the removal of residual matter.
In the present invention, the organic solvent for use in the silica film-forming composition is preferably an organic solvent which provides the composition as a uniform solution. Examples thereof include alcohols such as methanol, ethanol, propanol and pentanol; ether.acetals such as tetrahydrofuran and 1,4-dioxane; aldehydes such as acetaldehyde; ketones such as acetone, diacetone alcohol and methyl ethyl ketone; and polyhydric alcohol derivatives such as ethylene glycol, propylene glycol and diethylene glycol. Among these, in view of control of the reaction rate, alcohols are preferred and ethanol is more preferred. These organic solvents may be used either individually or in combination of two or more thereof.
The purity of the organic solvent for use in the silica film-forming composition is not particularly limited and an organic solvent used in industry or commonly used over a wide range as a reagent may be used, but a higher purity organic solvent is preferred.
In preparing the silica film-forming composition, a general method for preparing a solution may be applied. For example, a method of adding an alkali and water each in a predetermined amount to an organic solvent, followed by stirring, and then adding tetraethoxysilane, followed by stirring may be used. Whichever added earlier in the mixing, a coating can be formed. In mixing water and tetraethoxysilane, both are preferably diluted with an organic solvent in view of control of the reaction.
The thus-prepared silica film-forming composition is a stable composition and causes substantially no deposition or precipitation before the composition is brought into contact with metal oxide powder. When the metal oxide powder is contacted with the composition, silica starts to selectively deposit on the surface of the metal oxide powder.
The production method of titanium oxide as a starting material of the silica-coated titanium oxide is not particularly limited and any method may be used. A titanium oxide produced by any production method such as high-temperature vapor phase oxidation of TiCl4, vapor phase hydrolysis of TiCl4, sulfuric acid process and chlorine process, may be used. With respect to the crystal form of titanium oxide, any of amorphous, rutile, anatase and brookite may be used and a mixture thereof may also be used. In view of control of the secondary particle size, the titanium oxide is preferably reduced in impurities as much as possible, more preferably reduced in the coagulation.
The production method of zinc oxide as a starting material of the silica-coated zinc oxide is not particularly limited and any method may be used. A zinc oxide produced by evaporation oxidation of electrolytic zinc metal, or produced by calcining zinc hydroxide, zinc carbonate, zinc sulfide, zinc oxalate or the like which are obtained by neutralizing an aqueous solution of water-soluble salt such as zinc sulfate and zinc chloride, or a mixture of the above-mentioned zinc oxide may be used. However, in view of control of the secondary particle size, the zinc oxide is preferably reduced in impurities as much as possible, more preferably reduced in the coagulation.
In the present invention, the silica film can be formed by immersing titanium oxide or zinc oxide in the silica film-forming composition and keeping it at a predetermined temperature to selectively deposit silica on the surface of titanium oxide or zinc oxide. Also, a method of previously preparing the film-forming composition and charging titanium oxide or zinc oxide in the composition, a method of previously suspending titanium oxide or zinc oxide in a solvent, adding other raw material components to prepare a film-forming composition and forming the silica film, or the like may be used. In other words, the order of charging raw materials of the film-forming composition and titanium oxide or zinc oxide is not particularly limited and whichever charged earlier, a silica film can be formed.
Among these methods, a method of preparing a suspension containing titanium oxide or zinc oxide, water, an organic solvent and an alkali, and adding thereto dropwise tetraalkoxysilane diluted with an organic solvent at a constant rate is preferred, because a denser silica film can be formed and a continuous process useful in industry can be established.
The silica film grows by the deposition on the surface of metal oxide and therefore, as the film formation time is longer, the coating can have a larger thickness. Of course, when the majority of silicic acid in the film-forming composition is consumed by the formation of coating, the film formation rate decreases, however, by sequentially adding silicic acid in an amount corresponding to the consumed portion, the silica film can be continuously formed at a practical film formation rate. In particular, when the silica film is formed by holding titanium oxide in the film-forming composition having added thereto a silicic acid corresponding to the desired thickness of silica film for a predetermined time and thereby the silicic acid is consumed, a silicic acid corresponding to the consumed portion may be further added after the silica-coated titanium oxide or silica-coated zinc oxide is taken out from the system, whereby the composition can be continuously used in the film formation on next titanium oxide or zinc oxide and a continuous process having high profitability and good productivity can be established.
In the case of a method of preparing a suspension containing titanium oxide or zinc oxide, water, an organic solvent and an alkali and adding thereto dropwise tetraalkoxysilane diluted with an organic solvent at a constant rate, a solution obtained by diluting tetraalkoxysilane corresponding to the desired thickness of silica film with an organic solvent is added dropwise at a constant rate agreeing with the hydrolysis rate, whereby the tetraalkoxysilane is completely consumed, a dense silica film having a desired thickness can be formed and when the produced silica-coated titanium oxide is taken out from the system, a high-purity product free of residual unreacted tetraalkoxysilane can be obtained. Of course, the solvent after the silica-coated titanium oxide or silica-coated zinc oxide is taken out can be recycled in the next film formation and thereby, a process favored with high profitability and high productivity can be established.
The temperature at the formation of silica film is not particularly limited but is preferably from 10 to 100xc2x0 C., more preferably from 20 to 50xc2x0 C. As the temperature is higher, the film formation rate is more increased, however, if the temperature is excessively high, the solution composition may not be maintained constant due to volatilization of components in the composition, whereas if the temperature is too low, the film formation proceeds at a low rate and this is not practical.
The pH at the film formation may be sufficient if it is in the alkali region. However, in the case of forming the silica film on a metal oxide having a solubility which increases depending on the pH, the pH of the film-forming composition is preferably controlled.
After the film formation, the silica-coated titanium oxide or silica-coated zinc oxide can be isolated by solid-liquid separation. The isolation may be performed by a general separation method such as filtration, centrifugal sedimentation and centrifugal separation.
By performing drying after the solid-liquid separation, silica-coated titanium oxide or zinc oxide reduced in the water content can be obtained. In the drying, a general drying method may be used, such as natural drying, hot air drying, vacuum drying and spray drying. In the case where coagulation of particles occurs by the drying, the aggregate may be ground.
In the silica-coated titanium oxide or silica-coated zinc oxide of the present invention, the silica film has a very high shape-following capability and since primary particles of titanium oxide or zinc oxide as a substrate each is coated with a dense silica film having high covering power, the silica film is not broken by the grinding. The grinding method is not particularly limited and a jet mill, a high-speed rotary mill or the like may be used.
In the silica film obtained by the above-described method, the ratio I of absorption peak intensity at 1,150 to 1,250 cmxe2x88x921 to absorption peak intensity at 1,000 to 1,100 cmxe2x88x921 on the infrared absorption spectrum (I=I1/I2, wherein I2 is absorption peak intensity at 1,150 to 1,250 cmxe2x88x921 and I2 is absorption peak intensity at 1,000 to 1,100 cmxe2x88x921) is 0.2 or more and the refractive index is 1.435 or more. The silica coating, as having a chemical bond or a functional group of silica film formed while not performing calcination in a conventional sol-gel method, exhibits specific physical properties different in the hydrophilicity, lipophilicity or the like from silica film obtained through calcination. Nevertheless, this silica coating is dense and practical.
The term xe2x80x9cdensexe2x80x9d as used in the present specification means that the silica film formed has a high density and is uniform and free of pin holes or cracks. The term xe2x80x9cpracticalxe2x80x9d as used means that the bonding between silica and the substrate metal oxide (xe2x80x94Sixe2x80x94Oxe2x80x94Mxe2x80x94 bonding, wherein M is Ti or Zn) is strong enough not to cause stripping or the like of the coating and the physical properties of silica-coated titanium oxide or silica-coated zinc oxide are not readily changed.
Furthermore, this silica film has good compatibility with the complicated shape of substrate titanium oxide or zinc oxide and even if the thickness is as small as about 0.5 nm, the film exhibits good covering power and high capability of masking the photocatalytic activity. Furthermore, since the silica film can be very reduced in the alkali metal content, the silica film is not dissolved even in an atmosphere of high temperature and high humidity and the physical properties of the silica-coated titanium oxide are not changed.
The silica-coated titanium oxide or silica-coated zinc oxide for use in the cosmetic composition of the present invention has a silica film thickness of 0.1 to 100 nm, preferably from 0.5 to 25 nm. If the thickness of silica film is less than 0.1 nm, a sufficiently high effect of masking the photocatalytic activity cannot be obtained and the cosmetic composition obtained cannot have preparation form stability in some cases, whereas if it exceeds 100 nm, a cosmetic composition having sufficiently high ultraviolet shielding ability may not be obtained and therefore, this is not preferred.
The silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention has a primary particle size of 5 to 200 nm, preferably from 5 to 120 nm. If the primary particle size departs from this range, a cosmetic composition having a high ultraviolet shielding ability may not be obtained and therefore, this is not preferred.
The term xe2x80x9cprimary particlexe2x80x9d as used in the present invention indicates a particle defined in Kiichiro Kubo et al., Funtai (Powder), pp. 56-66 (1979).
The photocatalytic activity measured by the tetralin auto-oxidation method of the silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention is 60 Pa/min or less, preferably 50 Pa/min or less. If the photocatalytic activity measured by the tetralin auto-oxidation method exceeds this range, a sufficiently high effect of masking the photocatalytic activity may not be obtained and the obtained cosmetic composition disadvantageously may fail in having preparation form stability.
The dye discoloration rate measured by the Sunset Yellow method (See below for further details) of the silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention is preferably 0.1 or less, more preferably 0.05 or less. If it exceeds 0.1, the effect of masking the photocatalytic activity is not sufficiently high the obtained cosmetic composition may fail in having high preparation form stability.
The organic ultraviolet absorber decomposition rate measured by the Parsol method (See below for further details) of the silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention is preferably 0.02 or less, more preferably 0.01 or less. If it exceeds 0.02, the effect of masking the photocatalytic activity is not sufficiently high and the obtained cosmetic composition may fail in having high preparation form stability.
The silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention need not be particularly calcined but, of course, may be calcined before use.
The surface of the silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention may be treated to be hydrophobic. Particularly, in the case of dispersing in oil at cosmetic formulation, those with the surface hydrophobitized are preferably used. In order to impart hydrophobicity, a method which comprises treating with one or more hydrophobicity-imparting materials selected from the group consisting of silicone oils, alkoxysilanes, silane coupling agents and higher fatty acid salts to coat the surface, may be applicable.
Examples of the hydrophobicity-imparting material include higher fatty acids such as wax, higher fatty acid glyceryl ester, higher fatty acid, higher fatty acid polyvalent metal salt and sulfonated aliphatic higher compound polyvalent metal salt; higher alcohol and the derivatives thereof; organic fluorine compounds such as per-fluorinated or partial-fluorinated higher fatty acid and per-fluorinated or partial-fluorinated higher alcohol; organic silicon compounds such as silicone oil dimethylpolysiloxane, methylhydrogenpolysiloxane, modified silicone oil), silane coupling agent, alkoxysilanes, chlorosilanes and silazanes. Among these, higher fatty acid polyvalent metal salt, silicone oil, silane coupling agent or alkoxysilanes is preferred. In view of practical effect, alkoxysilanes or silane coupling agent is more preferable. Surface treatment with alkoxysilanes can be carried out by a liquid phase method or a dry method. Preferred is a liquid phase method for the following reason. According to the method which comprises silica-coating by contacting the metal oxide fine particle with a silica film-forming composition, adding thereto hydrophobicity-imparting material without separating the fine particle, and if necessary, adding an alkali, water and a solvent, surface treatment of the silica-coated metal oxide with hydrophobicity-imparting material can be carried out continuously. Intermediate processes for separation and purification can be omitted in this method, therefore it is an industrially advantageous production method.
The coating amount of hydrophobicity-imparting material may be minimal amount or more for coating the surface of the silica-coated metal oxide particle completely with the hydrophobicity-imparting material. The upper limit of the addition amount of hydrophobicity-imparting material can not be generalized, but addition to excess is uneconomical because an amount of deposit other than the deposit on the surface of the silica-coated metal oxide particle increases. Generally, the amount of hydrophobicity-imparting material added is preferably from 0.5 to 30% by mass to the silica-coated metal oxide particle, and more preferably from 0.5 to 20% by mass. If the coating amount is less than 0.5% by mass, hydrophobicity is reduced, whereas if it exceeds 20% by mass, ultraviolet shielding ability may be reduced.
The polymer having a carboxyl group in the side chain is used for the cosmetic composition of the present invention. Examples of the polymer having a carboxyl group in the side chain include carboxyvinyl polymer, carboxymethyl cellulose, carboxymethyl starch, poly(sodium acrylate), alginic acid propylene glycol ester and alginic acid salt. Among these, carboxyvinyl polymer is preferred.
Mode for using the carboxyvinyl polymer is described below.
The carboxyvinyl polymer is mainly white fine powder obtained by forming an acrylic acid into a polymer by a solution polymerization and drying the polymer. This polymer is soluble in water. The solvent used for the polymerization may be benzene, ethyl acetate, a mixed solvent of ethyl acetate and cyclohexane, or the like. Since the solvent may remain and cause a problem in the safety, a mixed solvent of ethyl acetate and cyclohexane is preferably used in view of the product quality. The characteristic feature of carboxyvinyl polymer is attributed to the carboxyl group in the polymer. The polymer in the powder state is rigid and coiled due to no solvation. When the polymer is dispersed in water, the molecules are hydrated and the coiled state is loosened to a certain extent, whereby the viscosity increases.
When the polymer is further neutralized with an alkali, the carboxyl group is ionized to generate minus charge along the polymer skeleton and the resiliency thereof causes swelling, as a result, thickening abruptly occurs. By virtue of this thickening effect, the carboxyvinyl polymer is used in many cases for the purpose of stabilizing the preparation form of cosmetic composition, particularly an O/W emulsion such as cream and lotion, or a gel-like cosmetic material. The carboxyvinyl polymer is advantageous in that high thickening stability can be obtained with a low concentration, that reproducibility which cannot be realized by natural polymers can be attained, that the temperature stability and microorganism resistance are high, that the pH and viscosity which can be used have a wide range, and that good use property is provided at the application to skin. Therefore, the carboxy polymer is being more widely used in cosmetic materials as compared with other thickeners.
The viscosity behavior of carboxyvinyl polymer differs depending on the molecular weight, the degree of crosslinking, the molecular structure or the like, and the adaptability to cosmetic preparations also differs, however, the physical properties of the carboxyvinyl polymer which can be used in the cosmetic composition of the present invention are not particularly limited as long as these satisfy the Standards of Cosmetic Ingredients. Examples of the carboxyvinyl polymer which can be used in the cosmetic composition of the present invention include xe2x80x9cCARBOPOLxe2x80x9d, a trade name, produced by BFGoodrich.
The cosmetic composition of the present invention is produced by a conventional method using the above-described silica-coated titanium oxide or silica-coated zinc oxide and the carboxyvinyl polymer together with conventional raw materials which can be used for a cosmetic composition.
The cosmetic composition of the present invention is, but not limited to, a cosmetic composition having a liquid form and specific examples thereof include cream, essence, lotion, skin lotion, milky lotion and jell.
The cosmetic composition of the present invention is composed of a powder portion and an oil portion. The material constituting the powder portion includes, in addition to the silica-coated titanium oxide or silica-coated zinc oxide, an extender pigment (e.g., mica, talc, kaolin, calcium carbonate, magnesium carbonate, silicic acid anhydride, aluminum oxide, barium sulfate), a white pigment (e.g., titanium dioxide, zinc oxide) and a color pigment (e.g., red oxide of iron, yellow oxide of iron, black oxide of iron, chromium oxide, ultramarine, iron blue, carbon black). These materials may be appropriately blended. In order to further improve the feeling on use, a spherical powder (e.g., nylon powder, polymethyl methacrylate powder) may also be used. Furthermore, similarly to the silica-coated titanium oxide or silica-coated zinc oxide, fine particulate cerium oxide or the like may be used for preventing ultraviolet rays, and this particle is also preferably coated with the dense silica film of the present invention.
Examples of the oil portion blended in the cosmetic composition of the present invention include liquid petrolatum, squalane, castor oil, glyceryl diisostearate, glyceryl triisostearate, glyceryl tri-2-ethylhexanoate, isopropyl myristate, dimethylpolysiloxane, methylphenylpolysiloxane, petrolatum, diisostearyl maleate and purified lanolin.
In the oil portion, an organic ultraviolet absorber may also be blended. The organic ultraviolet absorber means an organic compound having a function of absorbing an ultraviolet ray, consuming the energy for the generation of heat, oscillation, fluorescence, radical or the like, and thereby protecting skin. The ultraviolet absorber which can be used in the cosmetic composition of the present invention is not particularly limited but examples thereof include ultraviolet absorbers of benzophenone type, salicylic acid type, PABA type, cinnamic acid type, dibenzoylmethane type and urocanic acid type. For example, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, dihydroxydimethoxybenzophenone, sodium dihydroxydimethoxybenzophenone-sulfonate, tetrahydroxybenzo-phenone, p-aminobenzoic acid, ethyl p-aminobenzoate, glyceryl p-aminobenzoate, amyl p-dimethylaminobenzoate, octyl p-dimethylaminobenzoate, ethyl p-methoxycinnamate, isopropyl p-methoxycinnamate, octyl p-methoxycinnamate, 2-ethylhexyl p-methoxycinnamate, sodium p-methoxycinnamate, glyceryl bis(p-methoxycinnamate) mono(2-ethylhexanoate), octyl salicylate, phenyl salicylate, homomenthyl salicylate, dipropylene glycol salicylate, ethylene glycol salicylate, myristyl salicylate, methyl salicylate, urocanic acid, ethyl urocanate, 4-t-butyl-4xe2x80x2-methoxydibenzoylmethane, 2-(2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)benzotriazole, methyl anthranilate, or the like is used.
The amount of the ultraviolet absorber blended is from 0.1 to 10% by mass, however, an appropriate amount is preferably determined according to the ultraviolet ray-absorbing power of the absorber. The silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention has a high effect of masking the photocatalytic activity and therefore, even when the metal oxide is used in combination with the organic ultraviolet absorber, the absorber can be prevented from decomposition, so that a cosmetic composition having high ultraviolet shielding ability can be provided and also, the carboxyvinyl polymer can be prevented from ultraviolet deterioration and more increased in the preparation form stability.
The cosmetic composition of the present invention may also contain an existing emulsifier in a general concentration. Examples of the emulsifier include those described in Japanese Standards of Cosmetic Ingredients (JSCI), 2nd Edition. Annotation, compiled by Nippon Koteisho Kyokai, issued by Yakuji Nippo, Ltd. (1984), Specifications of Ingredient Other Than Those Listed in JSCI, supervised by Examination Division, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, issued by Yakuji Nippo, Ltd. (1993), Specifications of Ingredient Other Than Those Listed in JSCI. Supplement, supervised by Examination Division, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, issued by Yakuji Nippo, Ltd. (1993), The Comprehensive Licensing Standards of Cosmetics by Category, supervised by Examination Division, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, issued by Yakuji Nippo, Ltd. (1993), and Kesho-hin Genryo Jiten (Handbook of Cosmetic Ingredients), Nikko Chemicals (1991). All emulsifies described in these publications can be used. Furthermore, tocopheryl phosphates may also be used as the emulsifier.
In the cosmetic composition of the present invention, an existing antiinflammatory or antiphlogistic ingredient may be used in combination or may be mixed. The antiphlogistic ingredient which can be used in the present invention is not particularly limited, but examples thereof include aniline derivative-type antiphlogistic, salicylic acid derivative-type antiphlogistic, pyrazolone derivative-type antiphlogistic, indomethacin-type antiphlogistic, mefenamic acid-type antiphlogistic, antarthritic, spasmolytic, antitussive, expectorant, bronchodilator, respiratory function ameliorator, antihistamine agent, antiallergic agent and antiinflammatory enzymatic agent.
When an antioxidant as a substance having an oxidation-inhibiting activity is used in combination in the cosmetic composition of the present invention, the amount of free radicals generated by ultraviolet rays can be suppressed low, whereby the photocatalytic activity of silica-coated titanium oxide or silica-coated zinc oxide can be more reduced and therefore, a safe cosmetic composition having a remarkably excellent preparation stability and a low phototoxicity can be obtained.
The antioxidant having an effect of suppressing the photocatalytic activity for use in the cosmetic composition of the present invention is not particularly limited, but examples thereof include vitamin A, xcex2-carotene, astaxanthin, vitamin B, vitamin C, magnesium L-ascorbic acid-2-phosphate, sodium L-ascorbic acid-2-phosphate, magnesium sodium L-ascorbic acid-2-phosphate, L-ascorbic acid-2-glucoside, L-ascorbic acid-2-phosphoric acid-5,6-benzylidene, natural vitamin E, dl-xcex1-tocopherol, dl-xcex1-tocopheryl acetate, sodium dl-xcex1-tocopheryl phosphate, ubiquinone, derivatives of these vitamins, cysteine, glutathione, glutathioneperoxidase, SOD, catalase, citricacid, phosphoric acid, polyphenol, catechine, tea extract, kojic acid, nucleic acid, hydroquinone and arbutin. One or more selected from these antioxidants may be blended.
Other than the above-described ingredients, the cosmetic composition of the present invention may contain ingredients commonly blended in cosmetic compositions, such as fats and oils, waxes, hydrocarbons, fatty acids, alcohols, polyhydric alcohols, saccharides, esters, metal soap, water-soluble polymer compound, surfactant, antioxidant, microbicide antiseptic, vitamin, hormone and coloring material.
The amount of the silica-coated titanium oxide or silica-coated zinc oxide blended in the cosmetic composition of the present invention is from 0.1 to 50% by mass, preferably from 0.5 to 35% by mass, still more preferably from 1 to 20% by mass, based on the cosmetic composition.
The titanium oxide used for the purpose of shielding ultraviolet rays generally has a higher proportion of rutile form than anatase form. However, the silica-coated titanium oxide for use in the cosmetic composition of the present invention is greatly reduced in free radicals generated by ultraviolet rays and therefore, irrespective of the crystal form, a safe cosmetic composition favored with excellent preparation form stability and low phototoxicity can be obtained.
The cosmetic composition of the present invention not only has preparation form stability and ultraviolet shielding ability but also even when titanium oxide or zinc oxide is blended in a high concentration, ensures excellent feeling on use without causing any creaky feeling or poor extension. The cosmetic composition of the present invention has high transparency and does not cause pale finish on makeup as encountered in the case of containing a conventional titanium oxide or zinc oxide powder. Furthermore, photocatalytic activity of titanium oxide or zinc oxide is sufficiently masked and therefore, extremely high storage stability can be obtained without accelerating denaturation of other ingredients in the composition. An organic ultraviolet absorber can be contained and therefore, higher ultraviolet shielding effect and preparation form stability can be achieved. Still further, by containing an antioxidant having an oxidation-inhibiting activity, the generation of active oxygen or the like can be greatly reduced and the safety to the human body can be elevated.
In the present invention, the thickness and the refractive index of silica film can be measured by using a silica film formed on a silicon wafer immersed in a system undergoing the synthesis of silica-coated titanium oxide or silica-coated zinc oxide. On this silicon wafer, the same silica film as on the metal oxide is formed. The refractive index of silica film can be determined by an ellipsometer (LASSER ELLIPSOMETER ESM-1A, manufactured by ULVAC). The thickness can be determined using a step gauge.
The infrared absorption spectrum (FT-IR-8000 manufactured by Nippon Bunko) of silica film of the silica-coated titanium oxide or silica-coated zinc oxide can be determined by the KBr method. The primary particle size of silica-coated titanium oxide or silica-coated zinc oxide and the thickness of silica film thereof can be determined from an image by a transmission type electron microscope.
The photocatalytic activity, namely, the initial oxygen consumption rate of silica-coated metal titanium oxide or silica-coated zinc oxide of the present invention can be measured by the tetralin auto-oxidation method (see, Manabu Kiyono, Sanka Titanxcx9cBussei to Oyo Gijutsu (Titanium Oxidexe2x80x94Physical Properties and Applied Technique), pp. 196-197, Gihodo (1991)). The measurement conditions are such that the temperature is 40xc2x0 C., tetralin is 20 ml and titanium oxide is 0.02 g.
The photocatalytic activity of silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention is further determined as a dye discoloration rate by the Sunset Yellow method or an organic ultraviolet absorber decomposition rate by the Parsol method, which are described in the present specification.
The light transmittance of silica-coated titanium oxide or silica-coated zinc oxide for use in the present invention is determined by the Cosmol method described in the present specification.


In a pivot support portion of a hinge assembly of an assist grip, an outer support and an inner support are provided at a distance from each other. Between the inner support and the outer support, a double torsion spring stored in a spring case is inserted, and the grip body is biased toward a non-use position side by the double torsion spring. An opening is formed in a middle portion of the spring case. Legs at both sides of the double torsion spring are retained at the inside of the spring case. A middle leg of the double torsion spring projects from the opening of the spring case to be retained by a part of the grip body.

Assist grips are installed on a ceiling surface inside a vehicle compartment to provide a support for vehicle occupants in the compartment. This kind of assist grips having such a structure that cavities are formed at opposite sides of a grip body and hinge assemblies are installed in the cavities in a rotatable fashion, and the grip body is rotatably mounted via the hinge assemblies have been mounted in various automobiles.
On the hinge assembly of this kind of assist grip, as shown in, for example, JP3774845 B, a torsion coil spring for biasing around a hinge shaft thereof is mounted so as to bias the grip body toward a non-use position relative to the hinge assembly by a spring force of the torsion coil spring.
The torsion coil spring to be mounted on the hinge assembly is usually arranged between a pair of supports provided in a projecting manner at a lower portion of the hinge assembly, and is mounted in a space between the supports, with one end of the spring being engaged with the hinge assembly, and the other end of the spring being engaged with the grip body.
The torsion coil spring, at the time of assembly, while biasing the grip body up to the non-use position relative to the hinge assembly, is to be attached between a pair of supports at the lower portion of the hinge assembly, however, the torsion coil spring needs to be oriented in a predetermined direction as its direction and mounted being biased in a torsional state, and thus the work for attaching a small-sized torsion coil spring into such a configuration by hand is troublesome and difficult.
Moreover, the space between the supports of the hinge assembly in the hinge cavity of the grip body is large relative to an external shape of the torsion coil spring, and a considerable clearance is interposed around the spring. Therefore, the torsion coil spring inserted between the supports is likely to be mounted obliquely shifted from an axial center position of the hinge shaft in terms of a mounted state thereof.
Therefore, when the torsion coil spring is attached in an inclined manner between the pair of supports of the hinge assembly, it is difficult to exert a constant torsional torque to the hinge assembly in a torsional direction thereof, and rotational torque between the hinge assembly and the grip body by the torsion coil spring varies for every product, so that it becomes difficult to manage the rotational torque of the hinge assembly at a previously set constant value. Moreover, when the torsion coil spring is attached with its axis obliquely shifted with respect to the hinge shaft of the hinge assembly on which the torsion coil spring is mounted, noise is likely to occur due to friction between coil wires or due to friction between the torsion coil spring and a wall surface of the hinge cavity of the grip body when the grip body is operated to rotate relative to the hinge assembly.
An assist grip arranged is described in JP2010-159032 A such that a torsion coil spring that biases the grip body to the non-use position relative to the hinge assembly is stored in a cylindrical spring case, and the spring case storing the torsion coil spring is mounted to the inside of the hinge assembly.
The assist grip structured such that the spring case storing the torsion coil spring is mounted to the inside of the hinge assembly allows assembling in positional alignment relatively easily when mounting the spring case to the inside of the hinge assembly, but the torsion coil spring is twisted between one and the other ends thereof when the grip body rotates from the non-use position to the in-use position in use, and the coil spring is loaded in a direction to incline its axis, so that the torsional coil spring is likely to be inclined. Therefore, when the torsion coil spring is inclined in its posture along the axis, an outer peripheral portion of the coil spring slidingly contacts an inner surface, sliding contact further occurs between coil wires, and there has still been a problem that rotational force of the grip body by a spring force of the torsional coil spring is likely to become unstable.
The present invention has been made in view of the problems described above, and at least one object thereof is to provide an assist grip capable of stably exerting a rotational force of the grip body by a spring force. Furthermore, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.


An image forming apparatus includes a fixing device to fix an image on a recording medium, at least one temperature control target to be kept to or below a reference temperature, and a cooling system to insulate the temperature control target from the fixing device. The cooling system includes an air vent to introduce external air into an apparatus body, an exhaust duct assembly disposed between the fixing device and the temperature control target, a first inlet formed in the exhaust duct assembly to cause the external air to pass through a range in which the temperature control target is provided, and a first fan to generate airflow inside the exhaust duct assembly.

1. Technical Field
The present invention generally relates to a cooling system capable of thermal insulation between a temperature control target and a fixing device and cooling of the temperature control target thermally insulated from the fixing device; and further to an image forming apparatus, such as a copier, a printer, a facsimile machine, a plotter, or a multifunction peripheral (MFP) including at least two of coping, printing, facsimile transmission, plotting, and scanning capabilities, that incorporates the cooling system.
2. Description of the Background Art
Electrophotographic image forming apparatuses, such as, printers, copiers, facsimile machines, plotters, or multifunction machines typically include various components (hereinafter "temperature control targets") to be kept under predetermined reference temperature. Examples of temperature control targets include an image forming unit including a photoreceptor and a developing device, a reading device, an exposure device, and various types of motors. There are two factors to cause temperature rise of these components, namely, self-heating by driving or rotation thereof and thermal effects from separate heat sources.
Generally, the fixing device reaches a highest temperature inside the image forming apparatus and thus accounts for a major portion of the separate heat sources to affect the temperature rise of the temperature control target. Therefore, there are image forming apparatuses in which the fixing device is thermally insulated from an adjacent temperature control target. Other temperature control targets may be cooled locally as required.
For example, JP-2004-109356-A proposes thermally insulating the fixing device from the temperature control target.
In this configuration, an insulating member is provided between the fixing device and the temperature control target such as the image forming unit disposed above the fixing device, and heat of the fixing device is transmitted via air to the temperature control target to inhibit the temperature rise of the temperature control target.
Specifically, a planar heat pipe is provided between the temperature control target and the fixing device, and a heatsink provided at one end of the heat pipe is disposed inside an air duct for air suction and exhaust that parallels rotation shafts of a fixing roller and a pressure roller of the fixing device. An air suction fan is provided at one end of the air duct, and air introduced by the air suction fan into the air duct is directed to the heatsink. Heat absorbed by the planar heat pipe from the other end of the air duct is exhausted outside the apparatus.
Thermal insulation is thus provided between the temperature control target and the fixing device to prevent the temperature control target, which is positioned on the opposite side of the fixing device via the insulating member, from being heated by the heat from the fixing device.

Cooling system and image forming apparatus incorporating same


A control circuit for protecting a power device has been provided. The control circuit has a thermal shutdown circuit for activating a first SCR when the temperature of the control circuit exceeds a predetermined temperature. Additionally, the control circuit has a DSAT detection circuit for activating the first SCR in response to an external signal. The first SCR is coupled across an input terminal and the common terminal of the control circuit. When the first SCR latches, it functions to subsequently latch a second SCR that is coupled across the output and common terminals. The second SCR functions to rapidly discharge the voltage appearing across the output and common terminals.. Additionally, the control circuit includes an input level sensitive circuit which may be utilized to deactivate various circuitry depending upon the current level of an input signal supplied to the control circuit.

Power devices are utilized in a plurality of circuit applications that require high voltage and current capability, for example, automotive circuits. However, even power devices must be protected from large surge currents which could destroy the device.
Control circuits are typically utilized to protect power devices by monitoring the current flowing through the power device. Further, most control circuits for power devices are voltage driven. However, the disadvantage of voltage driven control circuits is that they are much more susceptible to voltage transients, for example, transients that are ground bounce induced.
One type of current driven control circuit is fully described in U.S. Pat. No. 5,006,736, having an issue date of Apr. 9, 1991. This patent describes a control circuit for both limiting the gate voltage of a power device and discharging the gate-source capacitance of the power device. However, this patent does not teach utilizing additional control circuitry for detecting over-current or over-temperature conditions of the power device.
Hence, there is a need for an improved current driven circuit for controlling a power device and detecting over-current and over-temperature conditions of the power device.

Current driven control circuit for a power device


A motor vehicle has a vehicle interior compartment and variable vehicle structures, by way of which the vehicle interior compartment can be modified. In order to improve the comfort in an autonomous driving mode, the vehicle interior compartment is enlarged in an autonomous driving mode.

Australian standard patent AU 2008258189 B2, which is incorporated by reference herein, has disclosed a vehicle having a fixed base, a top side which can be lifted up, and a flexible wall panel which extends between the fixing base and the top side, and having one or more inflatable vessels which are connected to the flexible wall panel and are suitable for expanding during inflation, in order to bring it about that the top side which can be lifted up is lifted up relative to the fixed base and the interior compartment of the trailer is enlarged as a result. European laid open specification EP 1 595 756 A2, which is incorporated by reference herein, has disclosed a pneumatically inflatable component which is mounted in a stationary manner on a vehicle, the part being mounted on an external point of the vehicle body and, after being pumped up, exerting a protective function for the vehicle or against accidents and/or other functions such as the aerodynamic modification of the vehicle and/or the modification of the useful volume of the vehicle and/or similar functions which increase the safety and reliability of the vehicle. American laid open specification US 2002/0163221 A1, which is incorporated by reference herein, has disclosed a pick-up, the truck bed of which can be enlarged in a flexible manner.


The present invention is generally directed towards a remote access architecture for providing peer-to-peer communications and remote access connectivity. In one embodiment, the remote access architecture of the present provides a method for establishing a direct connection between peer computing devices via a third computing device, such as a gateway. Additionally, the present invention provides the following techniques to optimize peer-to-peer communications: 1) false acknowledgement of receipt of network packets allowing communications via a lossless protocol of packets constructed for transmission via a lossy protocol, 2) payload shifting of network packets allowing communications via a lossless protocol of packets constructed for transmission via a lossy protocol, 3) reduction of packet fragmentation by adjusting the maximum transmission unit (MTU) parameter, accounting for overhead due to encryption, 4) application-aware prioritization of client-side network communications, and 5) network disruption shielding for reliable and persistent network connectivity and access.

Communications over a network between two computers, for example a client and a server, can be implemented using a variety of known communication protocols. However, the protocol used for communications may not be as efficient or secure as desired. As an example, the network communications may include real-time data communications such as voice over IP (VoIP) communications. The real-time data communications may be communicated via an unreliable protocol such as the user datagram protocol in order to reduce latency in the telephone call. However, the VoIP communication may traverse a TCP/IP network or secure SSL gateway, which provides a reliable protocol to the VoIP communications. This may increase the latency in the telephone call that the unreliable protocol was intended to reduce. Techniques are needed for transmitting data via a lossless protocol that is intended for communication using a lossy protocol.

Systems and methods for communicating a lossy protocol via a lossless protocol


Audio processing devices and methods. An ambient microphone picks up ambient sound and a voice microphone picks up a speaker's voice. The voice microphone is located farther from the speaker's mouth when a device is held to one side of the speaker's face than when held to the other side. A signal indicates whether an expected position of the handheld body is a position on a left side or right side of a speaker's face. Ambient sound in the voice signal is reduced by applying a first algorithm configuration selected to process voice signals with lower signal-to-noise ratio when the expected position in on one side of the speaker's face, and by applying a second sound cancellation algorithm configuration selected to process higher signal-to-noise ratios when the expected position is on the other side of the speaker's face.

Handheld audio devices, such as telephone handsets or other audio pick-up devices, are able to use two or more microphones to perform audio processing such as noise cancellation or echo cancellation upon signals picked up from a main microphone positioned on the device to detect a user's spoken voice. In many handheld audio devices, the main microphone, which is generally referred to below as a "voice microphone," is located close to a central axis on the front of the handheld device to maintain a left-right symmetry for picking up the user's voice. The left-right symmetry provides similar audio pick-up performance with both left-handed and right-handed use. However, the industrial design of some electronic devices places other components on the central axis of the front of the handheld device, and displaces the voice microphone from such a location. In some instances, the voice microphone is asymmetrically located on the front of the handheld device, i.e., away from the central axis of the handheld device. This asymmetrical location of the voice microphone often results in disparate adaptive sound cancellation, such as echo or noise cancellation, performance between use of the handheld device when it is held to a right side or a left side of a speaker's face. Due to the likelihood that a right-handed user is likely to hold a handset on the left side of his or her face, and a left handed user is likely to hold a handset to the right side of his or her face, left-handed and right-handed users tend to experience different levels of echo or noise cancelling performance.
Some designs address this concern by including multiple microphones that are located on different portions of the handset where different subsets of those multiple microphones can be selected as a main voice pick-up microphone while others of those multiple microphones are selected as ambient noise microphones used to support adaptive sound cancellation processing. In those designs, some of those multiple microphones configured or selected to operate as voice pick-up microphones when the handset is held to the right side of a speaker's face, and others of those multiple microphones are configured to operate or are selected to operate as voice pick-up microphones when the handset is held to the left side of the speaker's face. The construction of devices with these multiple microphones increases the costs and circuit complexity of the device due to, for example, the additional microphones and the audio switching and selection processing that must be included.
Therefore, the performance adaptive sound cancellation processing based on ambient sounds detected by an ambient sound microphone that is applied to audio detected by another, asymmetrically placed voice pick-up microphone on a handset is able to be adversely affected based upon which side of the user's face a user is holding the handset.

Selective adaptive audio cancellation algorithm configuration


In a data erasing method of a nonvolatile semiconductor memory device, cells are subjected to the processings of executing programming by applying a voltage to the cells to set their threshold values at a given level or more, erasing the cells to set their threshold values at a lower level or less, executing weak programming once on a cell whose threshold value is lower than a further lower level, by applying a lower voltage to the cell, repeating the weak programming on the cell when its threshold value is still lower than the further lower level, until the value reaches the further lower level or more, verifying whether a cell is present whose threshold value is higher than the lower level, and returning the processing to the processing of setting the threshold values of the cells at the lower level or less, when verifying that the above cell is present.

1. Field of the Invention
The present invention relates to a nonvolatile semiconductor memory device, and a data erasing method thereof. For example, the invention relates to a NOR type flash memory and an NAN flash memory, in both of which blocks each comprising a plurality of memory cells are provided, and a data erasing processing is performed in units of one block, and also to a data erasing method applied to those flash memories.
2. Description of the Related Art
In a nonvolatile semiconductor memory device, electrons are injected into or eliminated from a number of memory cells (each corresponding to 1-bit data), whereby the threshold values of the memory cells are changed, and the data stored in each memory cell indicates "1" or "0" (in the case where the memory cells store multivalue data, the injected charge can take one of four levels according to the stored data).
In general, in a nonvolatile semiconductor memory device referred to as a NOR type flash memory, in programming (writing) (in which electrons are injected into a memory cell or cells), a memory cell to which data can be written in units of 1 bit can be designated. This is because when a bit line and a word line are designated, and voltages are applied to the bit line and the word line, a bias is set to enable the above memory cell only to be subjected to the programming. However, in an actual nonvolatile semiconductor memory product, a number of bits are written as programming at the same time, i.e., a number of memory cells are subjected to the programming at the same time, in order that the programming be carried out at a higher speed.
On the other hand, in a data erasing operation, a bias is applied to a word line and a well region, and thus memory cells sharing the well region with each other are all erased as a data erasing processing (generally, the data erasing processing is executed in units of one block consisting of a number of memory cells). Thus, the data erasing processing of the nonvolatile semiconductor memory device comprises the following series of operations (steps), which will be explained with reference to FIG. 1, which is a flowchart of a series of step in a data erasing operation in a conventional nonvolatile semiconductor memory device.
First, in a block in which memory cells storing data indicating "1" (which are in an erased state) and memory cells storing data indicating "0" (which are in a programmed (written) state) are randomly present, only the memory cells storing the data indicating "1" are subjected to preprogramming (i.e., writing before the data erasing processing) in which the threshold value of a memory cell or cells to be processed is set to be equal to or higher than a voltage program verify (PV) level (step S101). FIG. 11A shows distribution of the threshold values of the memory cells not yet subjected to the above preprogramming, and FIG. 11B shows distribution of the threshold values of the memory cells subjected to the preprogramming.
Then, all the memory cells in the block are erased as a data erasing processing (step S102). In this processing, the threshold values of the memory cells are all lowered to be equal to or lower than a voltage erase verify (EV) level. FIG. 11C shows distribution of the memory cells subjected to the above data erasing processing.
However, actual memory cells vary in dimensions and thickness, etc. Thus, actually, of the above memory cells subjected to the above data erasing processing, a memory cell or cells are in an over-erased state in which their threshold values are lower than a voltage over erase verify (OEV) level. Therefore, weak programming is performed on a memory cell or cells determined to be in the over-erased state with respect to the voltage OEV level.
The following is the weak programming of the conventional nonvolatile memory device:
First, it is verified as a verifying processing whether or not the threshold value of each of the memory cells is equal to or higher than the voltage OEV level (step S103). When it is verified that the threshold value of a memory cell is lower than the voltage OEV level, i.e., the memory cell is in the over-erased state, it is subjected to the weak programming (step S104). This weak programming does not mean programming (writing) performed by applying a high voltage for making the data stored in the memory cell indicate "0", i.e., it means programming (writing) performed by applying a voltage lower than the high voltage to the drain and gate in the memory cell.
After being subjected to the weak programming in the above manner, the above memory cell is re-subjected to the verifying processing (step S103). Also, when it is verified that the threshold value of the memory cell is still lower than the voltage OEV level, and the memory cell is re-subjected to the weak programming (step S104). The verifying processing and the weak programming are repeated until it is verified that the threshold value of the memory cell is equal to or higher than the voltage OEV level. Then, when it is verified that the threshold value of the memory cell is equal to or higher than the voltage OEV level, the memory cell to be processed is changed from the above memory cell to a memory cell subsequent thereto (step S105).
After the weak programming on all the memory cells in the over-erased state in the block is completed (step S106), it is verified whether or not the threshold values of all the memory cells exceed the voltage EV level (step S107). Then, when there is no memory cell whose threshold value exceeds the voltage EV level, the data erasing processing ends. On the other hand, when there is a memory cell or cells the threshold values of which exceed the voltage EV level, the step is returned to the step S102 (data erase processing), and the steps are successively carried out from the step S102. Those series of steps are carried out as the steps in the data erasing operation in the conventional semiconductor memory device.
However, the above conventional semiconductor memory device has the following problem:
After the data erasing processing, there is a case where a singular memory cell (which will be hereinafter referred to a singular memory cell B) is present which is subjected to data erasing such that its threshold value is far lower than the voltage OEV level. This problem arises even in the case where the first threshold values of the memory cells are equalized by the preprogramming. It can be considered that the above problem occurs mainly due to abnormality in the shape of the above singular memory cell or the coupling ratio, etc.
To be more specific, if a singular memory cell B (whose threshold value is singularly low) is present, the following problem arises: in the weak programming, a leak current flows into the singular memory cell B, as a result of which even when the actual threshold value of a normal memory cell A located on the same bit line as the singular memory cell B is equal to or higher than the voltage OEV level, it is mistakenly verified that the threshold value of the normal memory cell A is lower than the actual threshold value thereof. This is because the threshold of a memory cell is verified based on the amount of current in the memory cell. Therefore, the normal memory cell A whose threshold value is actually equal to or higher than the voltage OEV level is subjected to the weak programming. At this time, a drain voltage (drain stress) at the writing time is applied to the drain in the singular memory cell B, and thus a small number of electrons are injected thereinto, increasing the threshold value of the singular memory cell B. In such a manner, the weak programming is repeated until a leak current is prevented from flowing into the singular memory cell B being in the over-erased state. If the normal memory cell A is a memory cell the threshold value of which is close to the voltage EV level as shown in FIG. 3, when it is repeatedly subjected to the weak programming due to the presence of the singular memory cell B, its threshold value exceeds the voltage EV.
Accordingly, in the verifying processing, it is verified that the threshold value of the normal memory cell A exceeds the voltage EV level, and the processing to be performed is returned to the data erasing processing. However, after the singular memory cell B is re-subjected to the data erasing processing, its threshold is greatly lowered, since its characteristics does not vary (i.e., they depend on its shape), and its erasing speed is high. In this case, the weak programming is repeated a number of times in the same manner as stated above. In such a manner, the data erasing operation enters an infinite loop, and thus does not end.
Actually, when a nonvolatile semiconductor memory product is checked with respect to production specification, if the time for the erasing operation exceeds a given time period, the product is determined to be defective. Thus, according to the conventional method, the fraction of defective nonvolatile semiconductor memory productions is increased.
Furthermore, the above infinite loop also occurs in the case where the data erasing processing is performed on the memory cells in a block including a singular memory cell (which will be hereinafter referred to as a singular memory cell C) whose erasing speed is very low. In this case, the data erasing processing is performed such that the threshold value of the singular memory cell C is equal to or lower than the voltage EV levels as shown in FIG. 4, as a result of which the threshold values of most of the other memory cells in the block are equal to or lower than the OEV level. In such a manner, since the threshold values of memory cells located on the same bit line as the singular memory cell C are equal to or lower than the voltage OEV level, a leak current at the OFF time is large. Consequently, when each of the above memory cells is subjected to the verifying processing, it is mistakenly determined that the threshold of each memory cell is lower than the actual threshold value thereof, and thus the weak programming is performed more times than necessary. At this time, since the singular memory cell C is located on the same bit line as the above memory cells, the threshold value of the singular memory cell C is increased by a drain stress. Then, similarly, the other memory cells are subjected to the weak programming, as a result of which the threshold value of the singular memory cell C are further increased to exceed the voltage EV level as shown in FIG. 5. In such a state, finally, when the singular memory cell C is subjected to the verifying processing, it is verified that the threshold value of the singular memory cell C exceeds the voltage EV level, and the processing to be performed is re-returned to the data erasing processing. As a result, the thresholds of most of the memory cells other than the singular memory cell C become equal to or lower than the voltage OEV level again. Thus, a leak current increases, and the weak programming is repeated more times than necessary, in the same manner as in the above case. In such a manner, the erasing operation enters an infinite loop, and does not end, thus increasing the fraction defective.
As explained above, in the erasing processing in a nonvolatile semiconductor memory product, if an infinite loop occurs in which the erasing processing and weak programming are repeated, the nonvolatile semiconductor memory product is determined to be defective. Therefore, if the method of the conventional nonvolatile semiconductor memory device is adopted, the fraction of defective nonvolatile semiconductor memory products is increased. Furthermore, even if an infinite loop does not occur in a nonvolatile semiconductor memory product, when the weak programming is performed more times than necessary, the time required for the erasing operation is increased, thus degrading the function of the product, and increasing the time for testing the product.
Jpn. Pat. Appln. KOKAI Publication No. 8-255489 discloses the following technique: after the memory cell transistors are all subjected to a data erasing processing, it is determined whether a memory cell transistor or transistors being in an over-erased state are present or not with respect to each of a plurality of digit lines. If it is determined that a memory cell transistor being in the over-erased state is present, the memory cell transistor is specified, and weak programming (writing) is performed on the memory cell transistor only.

Nonvolatile semiconductor memory device which erases data in units of one block including a number of memory cells, and data erasing method of the nonvolatile semiconductor memory device


It is determined whether a job stored in an image forming apparatus is completed or not. When a result is YES, it is determined whether an uncompleted job of the same user as the completed job is present in a queue of the jobs. When a result is YES, it is determined not to perform notification. When the result is NO, it is determined to perform the notification. Thereby, completion notification is performed only when the last job is completed in the case where the queue contains the plurality of jobs of a certain user.

1. Field of the Invention
The present invention relates to a job completion notifying device, and particularly to a job completion notifying device that notifies a user corresponding to a job of completion of the job when execution of the job is completed.
2. Description of the Related Art
A technique of providing notification of completion of printing has been employed for a system in which an image forming apparatus such as an MFP (Multi Function Peripheral) or a printer is connected to personal computers over a network. For providing notification of completion of printing, such a technique and the like have been known that provides notification of a status of an executed job in response to every executed job.
Japanese Laid-Open Patent Publication No. 2005-018140 has disclosed a technique in which IDs are allocated for providing notification of print completion, and it is determined according to the ID number whether there is an omission of notification or not. When an ID number is missing, it is determined that the printing is already completed, and the notification of completion is performed.
Japanese Laid-Open Patent Publication No. 2002-204325 has disclosed a technique of providing notification of print completion in a copy job.
In a conventional system of providing notification of the print completion, when a plurality of jobs are issued to an image forming apparatus, and are continuously executed, notification is performed in response to completion of each job, and therefore a user cannot readily determine timing for taking in printed matters.

Job completion notifying device providing notification of completion of a job when job execution is completed

Konica Minolta Business Technologies, Inc.


The present invention supplies a solvent to the front surface of a substrate while rotating the substrate. Subsequently, the substrate is acceleratingly rotated to a first number of rotations, and a resist solution is supplied to a central portion of the substrate during the accelerating rotation and the rotation at the first number of rotations. Thereafter, the substrate is deceleratingly rotated to a second number of rotations, and after the number of rotations of the substrate reaches the second number of rotations, the resist solution is discharged to the substrate. The substrate is then acceleratingly rotated to a third number of rotations higher than the second number of rotations so that the substrate is rotated at the third number of rotations. According to the present invention, in application of the resist solution by spin coating, the consumption of the resist solution can be suppressed, and a high in-plane uniformity can be obtained for the film thickness of the resist film.

1. Field of the Invention
The present invention relates to a coating treatment method for a substrate, such as a semiconductor wafer and the like.
2. Description of the Related Art
In the photolithography process in manufacture of a semiconductor device, a resist coating treatment of applying a resist solution, for example, onto a semiconductor wafer (hereinafter, referred to as a "wafer") to form a resist film is performed. As the coating treatment method, the spin coating method is generally employed. The spin coating method is a method of supplying a resist solution R from a nozzle 11 to the central portion of the front surface of the wafer W with the wafer W sucked to a spin chuck 10 as shown in FIG. 12, and rotating the spin chuck 10 at a high speed so as to spread the resist solution R outward in the radial direction of the wafer W by the centrifugal force.
To perform such a resist coating, it is necessary to apply the resist solution onto the wafer with high in-plane uniformity.
Incidentally, since miniaturization of the pattern of the semiconductor device and reduction in film thickness are required, various resist solutions adaptable to such photolithography are developed. However, the cost of the resist solutions is rising more than before because the resist solutions are required to have precise physical properties, so that the resist solutions are very expensive in the present circumstances. Therefore, the consumption of the resist solution needs to be further reduced, and accordingly a coating method is desired which can save the resist more than before and ensure a high in-plane uniformity for the film thickness.
Hence, according to a conventionally proposed resist coating method, the solvent for the resist solution is used to pre-wet the top of the wafer, and the resist solution is supplied to the wafer while the wafer is rotated at a first number of rotations, so that the resist solution is applied spreading outward in a direction of the radial of the wafer. Immediately after stop of the supply of the resist solution, the wafer is decelerated to a second number of rotations to adjust the film thickness, and then accelerate to a third number of rotations to shake off the remaining solution (Japanese Patent Application Laid-open No. H11-260717). In this case, specifically, the first number of rotations is 4500 rpm, the second number of rotations is 500 rpm, and the third number of rotations is 3000 rpm.
However, when the supply amount of the resist solution is small, the resist solution has sometimes not fully spread to the edge of the wafer while the wafer is rotated at the first number of rotations because of a weak centrifugal force exerted on the resist solution. In this case, the resist solution has been further spread while the wafer is rotated at the third number of rotations so that the resist solution is applied over the entire wafer. In the case where the resist solution is spread separately at two stages as described above, the resist solution dries to decrease in flowability during the rotation of the wafer at the second number of rotations and therefore is different in speed of spreading on the wafer between the case when the wafer is rotated at the first number of rotations and the case when the wafer is rotated at the third number of rotations. More specifically, in the case of the wafer with a diameter of 300 mm, the film thickness of the resist film may be different between the outside and the inside with a circle with a radius of 120 mm as a boundary (occurrence of a so-called polarization of the film thickness), resulting in reduced in-plane uniformity of the film thickness.


The invention relates to a target processing tool, comprising a target carrier guidance assembly, said target carrier guidance assembly comprising:                a guide surface having a longitudinal axis in a first direction,        a target carrier for carrying and displacing a target along said first direction,        a bearing support mounted to the target carrier by means of a flexible mount,        a bearing arranged between the guide surface and the bearing support, and        a biasing element, connected to the target carrier and to the bearing support, adapted for biasing said bearing support along a second direction against the bearing, wherein preferably said second direction is perpendicular to said first direction.

The invention relates to a target processing tool, comprising a target carrier guidance assembly, said target carrier guidance assembly comprising a guide surface having a longitudinal axis, a target carrier for carrying and displacing a target along said longitudinal axis, and a bearing arranged between said guide surface and said target carrier for facilitating low-friction movement of the carrier relative to the guide surface. The invention relates in particular to such a target processing tool in which the bearing is mechanical in nature, e.g. comprising one or more ball bearings.
Such processing tools, especially when comprised in a lithography system for patterning a target, are often subjected to substantial changes in temperature. When the guide surface is not sufficiently smooth, or is deformed for example due to thermal expansion, the target carrier may become misaligned with the guide surface, reducing positioning accuracy of the target carrier and increasing wear of the bearings.
It is an object of the present invention to provide a target processing tool with improved tolerance of thermal expansion of the target carrier and/or of the guide surfaces.


A fuse apparatus for a vehicle has a greatly reduced number of wire harnesses, particularly around a steering column where operational switches are concentrated and a fuse box where circuits are concentrated, for lowering the cost of the electrical system, making the electrical system small and light and mitigating assembling work thereof. The fuse apparatus comprises a fuse box provided on the steering column and having a fuse to be connected with an operational switch on the steering column, and a coupling terminal provided on the fuse box, connected with the fuse. The operational switch is directly attached to the fuse box with a coupling terminal of the switch coupled to the coupling switch on the fuse box whereby a wire harness conventionally provided between the fuse box and the operational switch is eliminated.

1. Field of the Invention
The present invention relates to a fuse apparatus for operational switches provided around a steering column of a vehicle.
2. Discussion of Relevant Art
Around the steering column are provided various operational switches for wipers, lighting, winker lamps etc. and an ignition switch disposed concentrically therewith. The operational switches are connected with the ignition switch through fuses and the ignition switch is connected with a battery through a main fuse.
FIG. 3 is a rough block diagram showing a wiring structure in such a conventional electrical system.
An ignition switch 02, a wiper switch 03, a lighting switch 04 and a winker switch 05 are attached to a steering column section 01. The wiper switch 03 is connected with a wiper motor 011 and a washer motor 012 through wire harnesses 030 to control their driving, the lighting switch 04 is connected with various lights, including head lights, through another wire harnesses 030 to control lighting, and the winker switch 05 is connected with a winker lamp 014 through another wire harness 030 to control lighting of the winker lamp.
Fuses interposed between the ignition switch and each of the operational switches 03, 04, 05 are gathered within a fuse box 010 and disposed under an instrument panel or the like. On the one hand, a battery 020 disposed within an engine compartment is connected with the ignition switch 02 through a main fuse 021.
The operational switches 03, 04, 05 on the steering column section 01 are connected with the fuse box 010 under the instrument panel through respective wire harnesses 031 and the ignition switch 02 is also connected with the fuse box 010 through a wire harness 032. Further, the ignition switch 02 is connected with the main fuse 021 through a wire harness 033. The fuse box 010 is also connected with the winker lamp 014 through a hazard switch 06 provided on the instrument panel or the like.
Since the steering column section 01 has many wire harnesses 030, 031, 032, 033 going in and out, assembling work therefor is troublesome and cost is high.
In advancing automobile electrical systems of recent years, the number of circuits and electric parts tend to increase, therefore, with the conventional construction of the electrical systems, the wire harnesses are enlarged more and more which causes problems such as high cost, increased weight and increased labor in the assembling work.


Provided is a steel sheet having excellent image clarity after painting, including: carbon (C): 0.001% to 0.03%, silicon (Si): 0.001% to 0.35%, manganese (Mn): 0.05% to 2.2%, phosphorus (P): 0.003% to 0.1%, sulfur (S): 0.001% or 0.025%, aluminum (Al): 0.01% to 0.1%, nitrogen (N): 0.001% to 0.007%, and a remainder of iron (Fe) and inevitable impurities. The microstructure of the steel sheet mainly is ferrite phases. An R-cube texture of a surface layer of the steel sheet is 5% or less by area %.

In general, the cold-rolled steel sheet manufactured in a steel process is excellent in terms of formability, and is widely used as an outer panel material for automobiles, home appliances, etc. due to having a relatively low price as compared to other materials. Such cold-rolled steel sheets are used in a state in which they are mostly coated through a coating process to improve corrosion resistance and secure aesthetics. Accordingly, in order to secure an excellent appearance after painting, research has focused on the technique of coating solutions, coating methods, and the like.
Even in the case of coated steel sheets, however, the appearance quality of the steel sheet may be affected by the surface quality of the steel sheet itself. According to Non-Patent Document 1, the lower the surface roughness (roughness average, Ra) of the steel sheet, the lower the medium wavelength roughness (waviness curve average, Wca). The lower the Wca of the steel sheet, the better the appearance thereof. This is prominent in stochastic rolling process methods such as EDT and short blast. Non-Patent Document 1 somewhat describes the relationship between surface roughness of a material and image clarity thereof, but is silent on relationship between grains of the material and image clarity.
(Non-Patent Document 1) Assessment of steel surface roughness and waviness in relationship with paint appearance. (Int. J. Mach. Tools Manufact. Vol. 38. Nos 5-6, PP. 647-656. 1998)

Steel sheet having excellent image clarity after painting


The invention relates to a semiconducting polymer and a method of preparing a semiconducting polymer. The polymer in accordance with the invention has the repeating unit (--A--NH--B--S--), wherein A and B are conjugated groups. The polymer proves to be readily soluble already in customary organic solvents, without the groups A and B having been provided with saturated substituents, and, after doping, has an electric conductivity of approximately 1 S/cm. The method yields semiconducting polymers in accordance with the invention, which have a high molecular weight and few topological defects.

Polymers of the type mentioned in the opening paragraph are known per se. For example, in a publication by Cao et. al. in Synth. Met., 48 (1992), page 91, a description is given of the semiconducting polymer called polyaniline (PANI). Layers formed from the emeraldine salt-form of said polymer exhibit an electric conduction of up to approximately 100 S/cm when use is made of camphorsulphonic acid or dodecylbenzenesulphonic acid as the dopant. In general, the processability of the polymer is adversely affected by the presence of large conjugated chains. For example, processing, from solution, of the undoped electrically insulating form of polyaniline, i.e. the emeraldine base-form, requires the use of N-methylpyrrolidone, an amine or a strong acid, such as concentrated sulfuric acid, as the solvent. These solvents are unattractive for use on an industrial scale. Also the limited choice of solvents forms an impediment to an extensive application of these polymers. Within the art there is a need for semiconducting polymers which, despite the presence of a large conjugated system, exhibit a satisfactory solubility in customary organic solvents and, after doping, a satisfactory conductivity.