Shin-etsu Chemical Co., Ltd.

Shigehiro Hoshida

Tadashi Amano

Kazunori Kondo

Susumu Ueno

Toru Nakanishi

Michio Aizawa

Masahiro Usuki

Genji Noguki

Kouzou Kuwabara

Hirokazu Nomura

Makoto Fujiwara

Yoshihiro Shirota

Osamu Matsumoto

Hideo Yoshikoshi

Makoto Suzuki

Kenji Fushimi

Kouiti Kuroda

Tatsuo Ishii

Sadaichi Arima

The present invention provides a halogen-free, flame retardant adhesive composition that exhibits excellent anti-migration properties, not only within single layer structures, but also within multilayer structures of much higher density. The flame retardant adhesive composition according to the present invention comprises: (A) a halogen-free epoxy resin, (B) a carboxyl group-containing acrylic resin and/or a carboxyl group-containing acrylonitrile-butadiene rubber, (C) a curing agent, (E) a specific polyphosphoric acid-melamine-based compound salt and/or polyphosphoric acid-diamine compound salt, and (F) an ion scavenger and/or a heavy metal deactivator.

Flame retardant adhesive composition, and adhesive sheet, coverlay film and flexible copper-clad laminate using same

The present invention provides a halogen-free, flame retardant adhesive composition that exhibits excellent anti-migration properties, not only within single layer structures, but also within multilayer structures of much higher density such as copper-clad laminates. The flame retardant adhesive composition according to the present invention comprises: (A) a halogen-free epoxy resin, (B) a carboxyl group-containing acrylic resin and/or a carboxyl group-containing acrylonitrile-butadiene rubber, (C) a curing agent, (E) specific phosphinate and/or diphosphonate compounds, and (F) an ion scavenger and/or a heavy metal deactivator.

Provided is a flame retardant adhesive composition including (A) a halogen-free epoxy resin, (B) a thermoplastic resin and/or a synthetic rubber, (C) a curing agent, (D) a phytate compound, and (E) a curing accelerator. Also provided are an adhesive sheet having a layer including the above composition, and a protective layer for covering the layer including the composition; a coverlay film having an electrically insulating film, and a layer including the above composition provided on top of the film; and a flexible copper-clad laminate having an electrically insulating film, a layer including the above composition provided on top of the film, and copper foil. Further provided are a process for producing the adhesive sheet, a process for producing the coverlay film, and a process for producing the flexible copper-clad laminate. The halogen-free adhesive composition yields a cured product, on curing, that exhibits excellent flame retardancy and electrical characteristics (anti-migration properties). The composition can be used for producing an adhesive sheet, a coverlay film, and a flexible copper-clad laminate.

Provided is a flame retardant adhesive composition including (A) a halogen-free epoxy resin, (B) a thermoplastic resin and/or a synthetic rubber, (C) a curing agent, (D) a nitrogen-containing polyphosphate compound, and (E) a curing accelerator. Also provided are an adhesive sheet having a layer including the above composition, and a protective layer for covering the layer including the composition; a coverlay film having an electrically insulating film, and a layer including the above composition provided on top of the film; a flexible copper-clad laminate having an electrically insulating film, a layer including the above composition provided on top of the film, and copper foil; and a method of bonding two substrates, including the steps of sandwiching the above adhesive sheet between two substrates, and curing the adhesive sheet. Further provided are a process for producing the adhesive sheet, a process for producing the coverlay film, and a process for producing the flexible copper-clad laminate. The halogen-free adhesive composition yields a cured product, on curing, that exhibits excellent flame retardancy and anti-migration properties. The composition can be used for producing an adhesive sheet, a coverlay film, and a flexible copper-clad laminate. The adhesive sheet can be used for a method of bonding two substrates.

A flexible metal foil/polyimide laminate is prepared by applying a polyamic acid varnish onto a very thin copper foil on a carrier, semi-drying the varnish, laminating a polyimide film to the varnish-coated copper foil using a hot roll press, and heat treating the laminate for solvent removal and imidization in an atmosphere having a controlled oxygen concentration. A polyimide adhesive layer resulting from the imidization of polyamic acid has a thickness of up to 6 &#x3bc;m, the sum of the thicknesses of the polyimide film and the polyimide adhesive layer is up to 25 &#x3bc;m. The polyimide adhesive layer has a Tg&#x3e;400&#xb0; C.

Preparation of flexible copper foil/polyimide laminate

An adhesive sheet made of an acrylic adhesive composition comprising (A) an acrylic polymer containing carboxyl groups and having a Tg of 5-30&#xb0; C., (B) a resol phenolic resin, (C) an epoxy resin, and (D) a curing accelerator has improved heat resistance, processing and handling as well as good adhesion, and is suited for use in the manufacture of FPC.

Acrylic adhesive sheet

A polyimide precursor resin solution composition sheet having a solvent content of 1&#x2013;50% by weight and a thickness of 1&#x2013;10 microns has improved adhesion, forms a heat resistant polyimide layer when cured, and is advantageously used in the bonding of conductors to plastic films.

Polyimide precursor resin solution composition sheet

The invention discloses a method for counting foreign matter particles in a vinyl chloride resin powder comprising the steps of: forming an aqueous dispersion of the resin particles in a vessel having a transparent bottom, allowing the particles to settle forming a layer together with the foreign matter particles and viewing the layer of the deposited particles through the transparent bottom of the vessel to count the foreign matter particles in the deposited layer. The invention also provides an apparatus system for automatically counting foreign matter particles which comprises a vessel having a transparent bottom, a feed means for the resin powder, a water supply means, a stirrer means to form an aqueous dispersion in the vessel, a viewing means such as a CCD camera for recording the bottom image of the deposited layer through the transparent bottom of the vessel, and a control means for bringing the various parts of the system into a sequential linkage motion.

Method for counting foreign matter particles in vinyl chloride-based resin powder and apparatus system therefor

A vinyl chloride polymer is prepared by charging a reactor with a vinyl chloride monomer, effecting polymerization, removing a slurry of the polymer from the reactor, and washing the reactor interior with water, and repeating the series of steps. The reactor has an internal volume of at least 40 m,. A cylinder-guided lift type washer assembly having a nozzle is secured to the reactor at its top in a sealed manner such that the nozzle can be moved downward and upward in the reactor. Water is fed to the nozzle through the assembly for injecting water from the nozzle into the reactor for cleaning. The large size reactor can be effectively washed with water in the closed state, and vinyl chloride polymers of quality with least fisheyes are produced batchwise, leading to an improved productivity.

Preparation of vinyl chloride polymer

A process for producing a vinyl chloride polymer for matted moldings which comprises performing the suspension polymerization of vinyl chloride monomer or a mixture of vinyl monomers composed mainly of vinyl chloride in an aqueous medium, said suspension polymerization being performed after the addition of a dispersion obtained by dispersing a polyfunctional monomer having 2 or more ethylenic double bonds in the molecule into a solution containing a partially saponified polyvinyl alcohol having a degree of saponification of 25 to 65 mole % and an average degree of polymerization of 150 to 1000, thereby yielding a vinyl chloride resin composed of 5 to 90 wt % tetrahydrofuran-insoluble gel fraction, with the remainder being tetrahyrofuran-solubles.

Process for producing vinyl chloride polymer

An improvement is proposed in the process of suspension polymerizatiopn of vinyl chloride monomer in an aqueous polymerization medium, by which a resin product of high quality relative to the contents of foamy resin and fish-eyes can be produced in a high efficiency with little deposition of polymer scale on the reactor walls. The improvment comprises heating and keeping the surfaces of the polymerization reactor and accessory equipment coming into contact with the gaseous phase above the polymerization mixture at a temperature of 55.degree. C. or higher during a period starting from a moment when the temperature of the polymerization mixture under temperature elevation up to the polymerization temperature is still 45.degree. C. or lower to a moment when conversion of the monomer into polymer is at least 10% so that foaming on the polymerization mixture can be greatly reduced.

Suspension polymerization of vinyl chloride with heating of reactor

A process for preparing a vinyl chloride polymer of the present invention comprises initiating suspension polymerization by suspending a vinyl chloride monomer in an aqueous medium in the presence of a first dispersion stabilizer and adding a second dispersion stabilizer at a specified time after the initiation of polymerization. Here, as the first dispersion stabilizer, (A) a partially saponified polyvinyl alcohol with a high saponification degree and (B) a hydroxypropylmethyl cellulose are used in combination, and as the second dispersion stabilizer, (C) a partially polyvinyl alcohol with a low saponification degree is used. According to the process, it is possible to prepare a vinyl chloride polymer with excellent characteristics such as plasticizer take-up, etc.

Process for preparing vinyl chloride polymer improved in plasticizer

A process for producing a vinyl chloride polymer for matted moldings which comprises performing the suspension polymerization of vinyl chloride monomer or a mixture of vinyl monomers composed mainly of vinyl chloride in an aqueous medium, in the presence of (A) 0.01 to 3 parts by weight of a polyfunctional monomer having two or more ethylenic double bonds in the molecule and (B) 0.00005 to 0.01 part by weight of antioxidant, thereby yielding a vinyl chloride resin composed of 5 to 90% by weight of tetrahydrofuran-insoluble gel fraction, with the remainder being tetrahydrofuran-solubles.

Process for producing vinyl chloride polymer with antioxidant

A process for preparing a vinyl chloride polymer, which comprises polymerizing vinyl chloride or a monomeric mixture composed mainly of vinyl chloride in an aqueous medium, wherein the polymerization reaction is terminated at the last stage of polymerization by addition of an aqueous dispersion of an antioxidant, containing a polyoxyalkylene glycol as a dispersing agent. A polymer with good initial coloration characteristic, thermal stability and take-up of plasticizer, and large bulk density can be obtained.

Process for terminating the polymerization of vinyl chloride with an

A process of producing a vinyl chloride polymer, comprising the step of suspension polymerizing vinyl chloride or a monomer mixture comprising mainly vinyl chloride in the presence of an oil-soluble polymerization initiator in an aqueous medium containing a dispersant, wherein said dispersant comprises:

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Ibaraki, Japan

Shigehiro Hoshida