Nitto-denko Corporation

Mitsuhiro Kanada

Takayuki Yamamoto

Tomohiro Taruno

Amane Mochizuki

Takahiro Fukuoka

Yoshihiro Minamizaki

Toru Iseki

Tomohide Bamba

Tomohide Banba

Kazumichi Kato

Hideyuki Tokuyama

Makoto Saito

Tadashi Takahashi

Makoto Kai

Katsuya Kume

Takami Hikita

Yoshio Terada

Kenji Furuta

Natsuki Kobayashi

Kohei Doi

Katsuhiko Tachibana

Junichi Sekiya

Mami Ikeya

Yusuke Yamanari

Naotaka Kinjou

Yasushi Buzoujima

Provided is a double-sided pressure-sensitive adhesive tape excellent in impact-absorbing property in the entirety of a wide temperature range, in particular, in a low-temperature region. The double-sided pressure-sensitive adhesive tape of the present invention includes: a base material layer; and pressure-sensitive adhesive layers arranged on both surface sides of the base material layer, wherein an entirety of the double-sided pressure-sensitive adhesive tape has a storage modulus of elasticity E' in a range of from 1.0×10Pa to 1.0×10Pa, which is measured at from −25° C. to 120° C. and a frequency of 1 Hz.

Double-sided adhesive tape

Provided is an adsorption temporary fixing sheet having a sufficient shear adhesive strength in a direction parallel to its surface, and having a weak adhesive strength in a direction vertical to the surface. Also provided is a method of producing such adsorption temporary fixing sheet. The adsorption temporary fixing sheet includes a foam layer including an open-cell structure, wherein, when a silicon chip vertical adhesive strength of a surface of the foam layer after 20 hours at each of such different temperatures as &#x2212;40&#xb0; C., 23&#xb0; C., or 125&#xb0; C. is represented by V1 (N/1 cm&#x25a1;), V2 (N/1 cm&#x25a1;), or V3 (N/1 cm&#x25a1;) and when a silicon chip shearing adhesive strength of the surface of the foam layer after 20 hours at each of the different temperatures (&#x2212;40&#xb0; C., 23&#xb0; C., or 125&#xb0; C.) is represented by H1 (N/1 cm&#x25a1;), H2 (N/1 cm&#x25a1;), or H3 (N/1 cm&#x25a1;), relationships of V1&#x3c;H1, V2&#x3c;H2, and V3&#x3c;H3 are satisfied.

Adsorptive temporary fixing sheet and method for manufacturing same

Provided is an adsorption temporary fixing sheet having a sufficient shear adhesive strength in a direction parallel to its surface, having a weak adhesive strength in a direction vertical to the surface, and having excellent antistatic performance. The adsorption temporary fixing sheet includes a foam layer including an open-cell structure, and has a surface resistivity of from 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;/&#x25a1;, wherein, when a silicon chip vertical adhesive strength of a surface of the foam layer after 18 hours at each of such different temperatures as &#x2212;30&#xb0; C., 23&#xb0; C., or 80&#xb0; C. is represented by V1, V2, or V3 (N/1 cm), and when a silicon chip shearing adhesive strength of the surface of the foam layer after 18 hours at each of such different temperatures as &#x2212;30&#xb0; C., 23&#xb0; C., or 80&#xb0; C. is represented by H1, H2, or H3 (N/1 cm&#x25a1;), relationships of V1&#x3c;H1, V2&#x3c;H2, and V3&#x3c;H3 are satisfied.

Adsorptive temporary fixing sheet

A pressure-sensitive adhesive sheet includes a pressure-sensitive adhesive layer and a substrate layer configured to support the pressure-sensitive adhesive agent layer. The pressure-sensitive adhesive layer has a storage modulus of 250 kPa or less at 23&#xb0; C. The substrate layer has an elastic modulus of 1680 N/cm to 3000 N/cm both inclusive. The pressure-sensitive adhesive sheet shows a deviation amount less than 1.0 mm. The amount is the deviation amount of the pressure-sensitive adhesive sheet per 250 gf/cmof the sheet in a holding ability test at 80&#xb0; C. after one hour from a time when the test is started.

Pressure-sensitive adhesive sheet

A composition for polyolefin resin foam, which comprises a polymer component comprising a polyolefin resin and a rubber and/or thermoplastic elastomer, and a powder particle, wherein the composition has an extensional viscosity as measured with a capillary rheometer (temperature, 200&#xb0; C.; shear rate, 5,000 [1/s]) of from 20 to 100 kPa&#xb7;s.

Composition for polyolefin resin foam, foam of the same, and process for producing foam

The invention provides an inorganic powder-containing resin composition capable of forming a dielectric layer having high light transmittance and excellent in surface smoothness. The invention also provides a film-forming material layer, a transfer sheet and a dielectric layer, which comprise the composition, a method of producing a substrate having a dielectric layer formed thereon, and a substrate having a dielectric layer formed thereon. The inorganic powder-containing resin composition comprises inorganic powder, a binder resin, and a phosphorus compound represented by formula (1): wherein R, Rand Rindependently represent H, an alkyl group, an alkylaryl group, NH(ammonium) or &#x2014;(CHCHO)&#x2014;R, wherein n is 1 to 15, and Rrepresents H, an alkyl group, an alkylaryl group or a (meth)acryloyl group.

Inorganic powder-containing resin composition, a film-forming material layer, a transfer sheet, method of producing a substrate having a dielectric layer formed thereon, and a substrate having a dielectric layer formed thereon

The present photosensitive resin compositioncomprises a polyamic acid resin, a photosensitive agent, a dispersible compounddispersible in the polyamic acid resin, and a solvent. The porous resin is obtained by removing the solvent from the photosensitive resin compositionto form a composition in which the dispersible compoundis dispersed in the polyamic acid resin, removing the dispersible compound to make the composition porous, and curing the porous photosensitive resin composition. The porous resin enables forming a fine circuit pattern and has a low dielectric constant and, when used as an insulating layer of a circuit board, brings about improved high frequency characteristics.

Photosensitive resin composition, porous resin, circuit board, and wireless suspension board

A method of producing porous polyimide resin that enables pores to be formed in a precursor of polyimide resin, with its form of microphase-separated structure wherein a dispersive compound is dispersed in the precursor of polyimide resin being kept unchanged, so as to provide significantly reduced dielectric constant and also provide improvement in mechanical strength and heat resistance, and the porous polyimide resin produced in the same producing method. A coating comprising porous polyimide resin is formed by applying resin solution comprising a precursor of polyimide resin and a dispersive compound and then drying a solvent, to form a coating in which the dispersive compound is dispersed in the precursor of polyimide resin; extracting the dispersive compound from the coating for removal to make the precursor of the polyimide resin porous; and imidizing the coating after preheated in a temperature range of 190&#x2013;250&#xb0; C.

Method for producing porous polyimide resin and porous polymide resin

The present photosensitive resin composition comprises a polyamic acid resin , a photosensitive agent, a dispersible compound dispersible in the polyamic acid resin , and a solvent. The porous resin is obtained by removing the solvent from the photosensitive resin composition to form a composition in which the dispersible compound is dispersed in the polyamic acid resin , removing the dispersible compound to make the composition porous, and curing the porous photosensitive resin composition. The porous resin enables forming a fine circuit pattern and has a low dielectric constant and, when used as an insulating layer of a circuit board, brings about improved high frequency characteristics.

A heat-resistant polymer foam is disclosed which has excellent heat resistance, a fine cellular structure, and a low apparent density. The heat-resistant polymer foam comprises a heat-resistant polymer having a glass transition point of 120&deg; C. or higher, e.g., a polyimide or polyether imide, and has an average cell diameter of from 0.01 &mgr;m to less than 10 &mgr;m. This heat-resistant polymer foam can be produced by, for example, impregnating a heat-resistant polymer under pressure with an non-reactive gas such as carbon dioxide, which is in, e.g., a supercritical state, reducing the pressure, and then heating the polymer at a temperature exceeding 120&deg; C. to foam the polymer.

Heat-resistant polymer foam, process for producing the same, and foam substrate

A finely foamed pressure-sensitive adhesive tape or sheet possessing a pressure-sensitive adhesive layer having a fine cell size and cell wall thickness is disclosed. The tape or sheet is obtained by impregnating the pressure-sensitive adhesive tape or sheet with carbon dioxide in a liquid state or a supercritical state, and reducing the pressure to foam the pressure-sensitive adhesive layer. The main component of the pressure-sensitive adhesive layer is, for example, an acrylic resin or a rubber-based resin. The method provides a finely foamed pressure-sensitive adhesive tape or resin possessing a pressure-sensitive adhesive layer having a fine cell structure such that an average cell size d is from 0.01 to 1000 &mgr;m, an average cell wall thickness t is from 0.01 to 2000 &mgr;m, and the ratio t/d is in the range of from 0.5 to 3.5.

Finely foamed pressure-sensitive adhesive tape or sheet and method for producing the same

A method of efficiently removing a low molecular weight substance from a polyimide precursor or polyimide in which the low molecular weight substance is dispersed as micro-domains, without using a large amount of an organic solvent. The method of removing a low molecular weight substance comprises subjecting either a polymer composition having a micro-domain structure made up of a continuous phase comprising a polyimide precursor and, dispersed therein, a discontinuous phase comprising a low molecular weight substance or a polyimide composition obtained from the polymer composition by converting the polyimide precursor into a polyimide to extraction with a combination of supercritical carbon dioxide and a co-solvent to thereby remove the low molecular weight substance. The co-solvent is preferably an aprotic polar solvent, more preferably a nitrogen compound solvent or a sulfur compound solvent.

Method of removing low molecular weight substance from polyimide precursor or polyimide containing low molecular weight substance

A porous article having excellent heat resistance, a finely cellular structure, and a low dielectric constant; and a process for producing the porous article which comprises subjecting a polymer composition having a micro-domain structure comprising a continuous polymer phase and dispersed therein a discontinuous phase having an average diameter smaller than 10 &mgr;m to a treatment for removing the ingredient constituting the discontinuous phase by at least one operation selected from vaporization and decomposition and by an extraction operation to thereby make the polymer porous. The ingredient constituting the discontinuous phase has a weight average molecular weight of, e.g., 10,000 or lower. Liquefied carbon dioxide, supercritical carbon dioxide, or the like can be used as an extraction solvent for the ingredient constituting the discontinuous phase.

Porous article and process for producing porous article

Acrylic pressure-sensitive adhesive composition and process for producing the same

A porous polyimide having a finely cellular structure and having a low dielectric constant and heat resistance. The porous polyimide can be produced by a process comprising adding a dispersible compound to a polyimide precursor to form a micro-domain structure in which the dispersible compound is dispersed in the polymer so as to have a size smaller than 10 &mgr;m and then removing the dispersible compound by extraction with supercritical carbon dioxide to thereby make the precursor porous, wherein the interaction parameter &khgr; between the polyimide precursor A and the dispersible compound B is larger than 3. This porous polyimide has an average cell diameter smaller than 5 &mgr;m and a dielectric constant of 3 or lower.

Growing community of inventors

Osaka, Japan

Mitsuhiro Kanada