Kansai Paint Company, Ltd.

Toshiaki Nagano

Hideo Sugai

Hideo Kogure

Terutaka Takahashi

Naozumi Iwasawa

Minoru Ishikura

Yasuyuki Kataoka

Tetsu Maki

Heihachi Murase

Tsutomu Maruyama

Takeshi Tomiyama

Atsushi Akiyama

Koki Chiga

Tooru Fukuda

Provided is a light weight and remarkably flexible sheet-shaped radio wave absorber having excellent radio wave absorbing capacity in milliwave band frequencies. The invention is a milliwave band radio wave absorption sheet comprising a radio wave reflection layer (A), a radio wave absorption layer (B) disposed above the layer (A) so as to be parallel thereto, and a protective layer (C) disposed above the layer (B) so as to be parallel thereto. The layer (B) has, at a frequency of 79 GHz, a dielectric constant, wherein the real part is 10 to 20 and the absolute value of the imaginary part is 4 to 10. The layer (B) has a film thickness of 200 to 400 &#x3bc;m. The absolute value of the imaginary part/real part from the dielectric constant is within a range of 0.30 to 0.60. The layer (C) has, at a frequency of 79 GHz, a dielectric constant, wherein the real part is 1.5 to 8.0 and the absolute value of the imaginary part is less than 1.0, and has a film thickness of 50 to 200 &#x3bc;m. In the milliwave band radio wave absorption sheet, the optical reflectance at an incident angle of 60&#xb0; is 50% or greater, and the optical reflectance at an incident angle of 20&#xb0; is 25% or greater. In addition, the invention provides a milliwave band radio wave absorption method using the radio wave absorption sheet, and a radio wave damage prevention method involving the installation of the radio wave absorption sheet.

Milliwave band radio wave absorption sheet and milliwave radio wave absorption method

This invention provides a multilayer coating film-forming method which comprises applying a first clear paint onto a coating object, applying onto so formed first clear coating film which is either uncured or cured by heating, a second clear paint such that its heat-cured film thickness falls within a range of 2-15 &#x3bc;m, and forming the second clear coating film, (a) the first clear paint and second clear paint comprising hydroxyl-containing resin as the base resin and polyisocyanate compound as the crosslinking agent, and (b) when the coating film formed by applying a paint to a cured film thickness of 40 &#x3bc;m and curing it by heating at 140&#xb0; C. for 30 minutes is measured of its dynamic viscoelasticity at a frequency of 11 Hz, the first clear paint forming the first clear coating film having a glass transition temperature of lower than 70&#xb0; C. and tan&#x3b4; (=loss elastic modulus/storage elastic modulus) at 80&#xb0; C. of less than 0.4, and the second clear paint forming the second clear coating film having a glass transition temperature of at least 70&#xb0; C.

Method for making multilayer coating film

This invention provides an aqueous primer composition which comprises (A) an aqueous dispersion of modified polyolefin which comprises an unsaturated carboxylic acid- or acid anhydride-modified polyolefin (a) having a melting point of 120&#xb0; C. or lower and a weight average molecular weight of 30,000 to 180,000, dispersed in an aqueous medium, (B) an ionic functional group-containing acrylic resin, and (C) a conductive carbon-containing pigment, and which forms a coating film with an L value of 35 or more and a surface resistivity of 1&#xd7;10&#x3a9;/&#x25a1; or less.

Aqueous primer composition and a process for the application of the same

This invention provides a water-based primer composition characterized by comprising an aqueous dispersion formed by dispersing unsaturated carboxylic acid- or acid anhydride-modified polyolefin (a) having a melting point of 50-120&#xb0; C. and a weight-average molecular weight within a range of 30,000-200,000, and unsaturated carboxylic acid- or acid anhydride-modified polyolefin (b) having a melting point of 30-100&#xb0; C. and a weight-average molecular weight within a range of 30,000-200,000, in an aqueous medium, the melting point of the modified polyolefin (a) being higher than that of the modified polyolefin (b) by at least 10&#xb0; C.

Water-based primer composition and coating method of plastic shaped articles using the composition

This invention provides a water-based primer composition comprising (A) an aqueous dispersion of modified polyolefin, which is prepared by dispersing a modified polyolefin (a) in an aqueous medium, the polyolefin (a) being produced by modifying an unsaturated carboxylic acid- or acid anhydride-modified polyolefin (i) having a melting point not higher than 120&#xb0; C. and an weight-average molecular weight within a range of 30,000-200,000, further with a compound having polyoxyalkylene chain; (B) at least one kind of aqueous resin selected from aqueous urethane resin, aqueous acrylic resin and aqueous polyester resin; and (C) pigment; the solid weight ratio of the component (A)/component (B) being within a range of 20/80-85/15, and containing the component (C) in an amount within a range of 0.5-200 parts by weight per 100 parts by weight of the total solid resin content of the composition. Use of the water-based primer composition enables to form coating film excelling in water resistance, humidity resistance, gasohol resistance and the like.

Water-based primer compositions

This invention discloses paint compositions characterized by comprising polyolefin or modified polyolefin (A) and ionic liquid (B), and coating methods using the compositions.

Paint compositions

A pollution-preventing process which comprises (i) controlling a surface moisture content of a first building material selected from the group consisting of an inorganic base material and wood at 0 to 20%, or (ii) coating a penetration-inhibiting primer onto a surface of a second building material having a surface moisture content of 10 to 100% and selected from the group consisting of an inorganic base material and wood to be dried, followed by coating a treating agent consisting of an organic solvent solution of a modified polysiloxane resin having a ladder structure onto a surface of the first building material or the second building material to impregnate the surface with the treating agent and by subjecting to curing treatment to prevent at least one pollutant selected from the group consisting of mold and moss from growing on the surface of the first building material or the second building material.

Pollution-preventing process

An electromagnetic wave reflection-preventing material having a structure formed by successively laminating (A) an electromagnetic wave reflecting material layer, if needed, (B) a supporting layer, (C) a resin layer, if needed, (D) a supporting layer, and (E) a metallic pattern layer prepared by arranging at least one of a pattern unit comprising a geometrical pattern formed by use of a continuous metallic band, or comprising a multi-figured structure formed by combining a plurality of band-shaped metallic figures so as not to contact with each other; and an electromagnetic wave reflection-preventing method by use of the electromagnetic wave reflection-preventing material.

Electromagnetic wave reflection-preventing material and electromagnetic

An electromagnetic wave reflection-preventing material having a structure formed by successively laminating (A) an electromagnetic have reflecting metallic material layer, if needed, (B) a substrate layer, (C) a resin layer containing a powder of at least one selected from ferrite, carbon, metal powder and an electrically conductive metallic oxide, and, if needed, a good dielectric material, if needed, (D) a supporting film layer, and (E) a pattern coating layer prepared in the form of a geometrical pattern, containing a metal powder and having a volume resistivity of 10.sup.-3 to 10.sup.10 .OMEGA..multidot.cm, preferably further laminating (F) a clear or colored coating layer; and an electromagnetic wave reflection-preventing material which is obtained by substituting (G) a molded sheet layer formed by coating a coating composition prepared by dispersing the above powder into a binder onto a substrate having void, and molding under pressure for (C) a resin layer; and an electromagnetic wave reflection-preventing method which comprises applying the electromagnetic wave reflection-preventing material onto a structure, or which comprises applying a laminate obtained by removing the electromagnetic wave reflecting metallic material layer (A) from the electromagnetic wave reflection-preventing material onto an electromagnetic wave reflecting structure having a metallic surface.

An electromagnetic wave reflection-preventing material having a structure formed by a process which comprises successively laminating (A) a pattern layer formed in the form of a geometrical pattern having a volume resistivity of 10.sup.3 .OMEGA. . cm or less, if needed, (B) a supporting layer, (C) a resin layer, and, if needed, (D) a supporting layer, to form a laminate unit, laminating a pluralitry of the laminate unit so that the layer (A) may face on the layer (C) or (D) to form a multiple laminate unit structure, and laminating the multiple laminate unit structure onto (E) an electromagnetic wave reflecting material layer so that the layer (C) or (D) of the multiple laminate unit structure may face on the layer (E), preferably further laminating a clear or colored coating layer onto the uppermost metallic pattern layer of the electromagnetic wave, reflection-preventing material; and an electromagnetic wave reflection-preventing method which comprises applying the electromagnetic wave reflection-preventing material onto a structure, or which comprises applying the multiple laminate unit structure obtained by removing the electromagnetic wave reflecting material layer (E) from the electromagnetic wave reflection-preventing material onto an electromagnetic wave reflecting structure having a metallic surface.

An electromagnetic wave absorber comprising at least one of a unit film as a multilayered film comprising a resin layer (A) optionally containing a pigment and a layer (B) applied onto the resin layer (A), selected from a group consisting of a metal layer, an alloy layer and a partly oxidized layer of the metal layer or the alloy layer, and having a film thickness of 1 nm to 50 nm.

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Yokohama, Japan

Toshiaki Nagano