Kawamura Institute of Chemical Research

Sakura, Japan

Kawamura Institute of Chemical Research

Sakura, Japan
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Haraguchi K.,Kawamura Institute of Chemical Research
Polymer Journal | Year: 2011

We have fabricated new types of polymer hydrogels and polymer nanocomposites, that is, nanocomposite gels (NC gels) and soft polymer nanocomposites (M-NCs), with novel organic/inorganic network structures. Both NC gels and M-NCs were synthesized by in situ free-radical polymerization in the presence of exfoliated clay platelets in aqueous systems and were obtained in various forms and sizes with a wide range of clay contents. Here, disk-like inorganic clay nanoparticles function as multifunctional crosslinkers to form new types of network systems. NC gels have extraordinary optical, mechanical and swelling/deswelling properties, as well as a number of new characteristics relating to optical anisotropy, polymer/clay morphology, biocompatibility, stimuli-sensitive surfaces, micropatterning and so on. The M-NCs also exhibit dramatic improvements in optical and mechanical properties including ultrahigh reversible extensibility and well-defined yielding behavior, despite their high clay contents. Thus, the serious disadvantages (intractability, mechanical fragility, optical turbidity, poor processing ability, low stimulus sensitivity and so on) associated with the conventional, chemically crosslinked polymeric materials were overcome in NC gels and M-NCs. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.


Ogasawara S.,Kawamura Institute of Chemical Research | Kato S.,Kawamura Institute of Chemical Research
Journal of the American Chemical Society | Year: 2010

A new strategy based on polymerization-induced phase separation (PIPS) techniques was proposed for fabricating palladium nanoparticles (PdNPs) captured in a microporous network polymer. Pd(OAc)2 was premixed with a monomer having a poly(amidoamine)-based dendrimer ligand, and subsequently this was thermally polymerized with an excess amount of ethylene glycol dimethacrylate under PIPS conditions. In this system, the formation of PdNPs occurred concurrently with the polymer synthesis in a one-pot process, even with no additional reducing reagent. The resultant microporous polymer was found to have a mesoporosity; the nitrogen sorption analysis gave a specific-surface area of 511 m2 g-1, an average pore diameter of 9.9 nm, and a total pore volume of 1.01 mL g-1. The TEM images of the polymer revealed that the created PdNPs were very small with a diameter of mainly ca. 2.0 nm; the high-resolution images were lattice-resolvable, showing the crystalline nature of the PdNPs (Pd(111) facets). Catalytic performances of the PdNP-containing microporous polymers were investigated for a heterogeneous Suzuki-Miyaura reaction of 4--bromoacetophenone and phenylboronic acid in water. In the presence of 10-2 molar equiv of the polymer, the reaction efficiently proceeded at 80 °C and gave the desired product, 4-acetylbiphenyl, in >90% yield after 2 h. On the basis of the ICP-AES analysis, the Pd content released into the solution phase was estimated to be only 0.27% of the initial charge. Thereby, this polymer was successfully recovered by simple filtration and reused with only a minimal loss of activity (yield >90% even at the eighth run). When the catalytic reaction was examined with a low amount of the polymer catalyst, the turnover number (TON) reached 8.5 - 104 while maintaining a good yield. Finally, the dendrimer template effect of the polymer catalyst was discussed by referring to the catalytic performances of a control polymer prepared with nonintegrated ligand monomers. © 2010 American Chemical Society.


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2011-05-04

A process for producing superhydrophobic powders comprising silica as the main component and the surface of the powders have a contact angle with water of 150 or larger; and a structure having a superhydrophobic surface comprising the powders. The process comprised: introducing hydrophobic groups into the silica present in the surface of aggregates of organic/inorganic composite nanofibers obtained by combining a polymer, which is an organic substance, with silica, which is an inorganic substance, on the order of nanometer or into the silica obtained by calcining the organic/inorganic composite nanofibers and removing the polymer there from; and thereby making powders composed of the aggregates superhydrophobic. Also provided is a superhydrophobic powders obtained by the process. The structure having a superhydrophobic surface is obtained by fixing the superhydrophobic powders to a surface of a solid substrate.


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2011-03-09

Disclosed are: an organic-inorganic complex dispersion improved in film formability and adhesion to a base material. The organic-inorganic complex dispersion comprises an aqueous medium and particles of a complex dispersed in the aqueous medium, wherein the complex has a three-dimensional network structure formed by a polymer of a monomer comprising a monomer represented by general formula (1) and at least one inorganic material selected from a water-swellable clay mineral and silica. Also disclosed is an antifogging material manufactured by using the organic-inorganic complex dispersion. Further disclosed is a cell culture substratum improved in the detachability of cells cultured on the substratum, which is manufactured by using the organic-inorganic complex dispersion. Still further disclosed are manufacturing methods for same. [In the formula, R1 represents a hydrogen atom or a methyl group; R2 represents an alkylene group having 2 to 3 carbon atoms; R3 represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms; and n represents a number of 1 to 9.]


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2011-03-31

There are provided an infrared absorbing thin film that efficiently absorbs infrared rays and has good versatility by controlling the absorption intensity of titanium oxide in an infrared region and a method for producing the infrared absorbing thin film. The infrared absorbing thin film containing a rutile-type titanium oxide crystal can be produced through a step of dispersing or dissolving a complex of an amino group-containing basic polymer and a transition metal ion in an aqueous medium; a step of obtaining a composite having a polymer/titania layered structure in which the complex of the amino group-containing basic polymer and the transition metal ion is sandwiched between layers of titania, by mixing the aqueous dispersion with a water-soluble titanium compound in the aqueous medium; a step of calcining the composite in an air atmosphere at a temperature of 650 C. or higher and pulverizing the obtained crystal into a powder; and a step of mixing the obtained powder with a sol of a metal alkoxide to prepare a fluid liquid composition, coating a surface of a substrate with the obtained fluid liquid composition, and aging the coating film.


Patent
Dainippon Ink, Chemicals and Kawamura Institute Of Chemical Research | Date: 2014-08-13

The problem to be solved by the present invention is to provide a nondrying polymer hydrogel, which is not dried under atmospheric conditions and has excellent mechanical properties, and a method for producing the nondrying polymer hydrogel, and it is found that the problem can be solved and a nondrying polymer hydrogel having both excellent nondrying properties and mechanical properties (e.g., excellent elongation properties, compression properties, and surface adhesiveness) can be produced by using a nondrying polymer hydrogel including a deliquescent substance in such a manner that the water vapor pressure shown by the polymer hydrogel is equal to or lower than the water vapor partial pressure in the atmosphere, in particular, by allowing a deliquescent substance to be contained at a high concentration in a polymer hydrogel having a network structure formed by a polymer of a water-soluble radically-polymerizable organic monomer having a specific chemical composition and a delaminated water-swellable clay mineral.


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2014-06-25

The object of the present invention is achieved by providing a copolymer, in particular, a block copolymer which has excellent coating formation ability, adhesive properties to a substrate, and does not adsorb protein; an antithrombotic coating agent which has superior antithrombotic properties and adhesive properties to a substrate to those of the conventional antithrombotic coating agent; and a medical instrument which is obtained by coating the antithrombotic coating agent, and the block copolymer includes a polymer (A) containing a (meth)acrylic ester monomer and a polymer (B) containing a (meth)acrylamide monomer and has excellent coating formation ability and high adhesive properties to a substrate.


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2011-02-23

The present invention relates to a structural object coated with a superhydrophobic nanostructure composite, the structural object being obtained by densely coating a surface of a solid substrate having a desired shape with a nanostructure obtained by combining a polymer having a polyethyleneimine skeleton with silica on the nanometer order, and bonding a hydrophobic group to the surface of the nanostructure, and a process for producing the structural object. The present invention also relates to a structural object coated with a superhydrophobic nanostructure composite, the structural object being obtained by removing the polymer having the polyethyleneimine skeleton from the nanostructure and bonding a hydrophobic group to the surface of the residual nanostructure containing silica as a main constituent component, and a process for producing the structural object. Furthermore, the present invention provides a method of using the structural object as a container for transferring an aqueous solution.


Patent
Dainippon Ink, Chemicals and Kawamura Institute Of Chemical Research | Date: 2012-08-10

The object of the present invention is achieved by providing a copolymer, in particular, a block copolymer which has excellent coating formation ability, adhesive properties to a substrate, and does not adsorb protein; an antithrombotic coating agent which has superior antithrombotic properties and adhesive properties to a substrate to those of the conventional antithrombotic coating agent; and a medical instrument which is obtained by coating the antithrombotic coating agent, and the block copolymer includes a polymer (A) containing a (meth)acrylic ester monomer and a polymer (B) containing a (meth)acrylamide monomer and has excellent coating formation ability and high adhesive properties to a substrate.


Patent
Kawamura Institute Of Chemical Research, Dainippon Ink and Chemicals | Date: 2013-06-19

The problem to be solved is to provide a nondrying polymer hydrogel, which is not dried under atmospheric conditions and has excellent mechanical properties, and a method for producing the nondrying polymer hydrogel. A nondrying polymer hydrogel having both excellent nondrying properties and mechanical properties (e.g., excellent elongation properties, compression properties, and surface adhesiveness) can be produced by using a nondrying polymer hydrogel including a deliquescent substance in such a manner that the water vapor pressure shown by the polymer hydrogel is equal to or lower than the water vapor partial pressure in the atmosphere, in particular, by allowing a deliquescent substance to be contained at a high concentration in a polymer hydrogel having a network structure formed by a polymer of a water-soluble radically-polymerizable organic monomer having a specific chemical composition and a delaminated water-swellable clay mineral.

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