Abstract: A low birefringent organic optical component prepared from a resin consisting essentially of one or more repetitive structural units selected from the group consisting of structures represented by general formula (1); ##STR1## wherein A is either of the groups below. ##STR2## The organic optical component can exhibit excellent transparency, heat resistance and mechanical strength as well as a low birefringence. Also provided is a novel aromatic polyamide with a low permitivity and excellent transparency, processability and thermal stability, besides excellent heat resistance inherent in an aromatic polyamide.

Abstract: The present invention provides a ground surface structure for prevention of weed growing. The structure includes a germination-preventing sheet (2) resistant to penetration of buds of a plant and laid over the surface of a selected ground (1). The structure also includes a surface layer (3) formed by accumulating a water-repellent earth material on the germination-preventing sheet (2). The earth material includes material grains formed with silicone coating. Typically, the germination-preventing sheet (2) is made of a nonwoven fabric material and resistant to penetration of buds of a plant. Further, the sheet blocks the passage of light, but exhibits water permeability and air permeability.

Abstract: The pigment dispersion composition having a good dispersibility, a good transparence and an anti-coating properties, which contains 0.5 to 50 parts by weight of an inorganic pigment, at least one type of dispersant selected from the group consisting of a sodium salt, an ammonium salt and an amine salt of an acrylic resin, an acryl copolymer resin, a polycarbonic acid, a condensation product of aromatic formalin sulfonate, and water or a solvent miscible with water.

Abstract: There is provided an aqueous resin composition which does not cause coagulation, can be cured at low temperature, and, by this curing, forms a coating superior in mechanical strength, water resistance, solvent resistance and adhesion to various substrates. The aqueous resin composition of this invention comprises an oxazoline group-containing polymer (A), a carboxyl group-containing polymer (B), and an acidic compound-amine salt catalyst (C). The curing is carried out by a reaction between the oxazoline group-containing polymer (A) and the carboxyl group-containing polymer (B) in the presence of the acidic compound-amine salt catalyst (C).

Abstract: The invention relates to colorants (colorant pastes) used for the tinting of paint products.

Abstract: A high bending strength and high density material for osteosynthesis, which comprises a biodegradable and bioabsorbable crystalline thermoplastic polymer material, and a high strength implant material, comprising a composite material in which a bioceramics powder of from 0.2 to 50 .mu.m in particle size is dispersed in the polymer material, wherein crystals of the polymer material are pressure-oriented not in a uni-axial direction but basically in parallel with a plurality of reference axes; and a production method by pressure orientation, which comprises preparing in advance a biodegradable and bioabsorbable crystalline thermoplastic polymer material or a dispersed mixture of the polymer material and a bioceramics powder and melt-molding it into a pre-molded material which is then press-charged at a cold temperature into a cavity of a closed type forming mold, thereby obtaining an oriented molding.

Abstract: The invention provides polymerizable dental, compounds, compositions, including the compounds and products for mixing the compositions and methods of using the compositions. Aryl acid compounds are provided in accordance with the invention. The compositions include at least one polymerizable aryl acid compound, an effective amount of a polymerization initiator, and at least 10 percent by weight of ceramic, metal and/or metal oxide filler particles having a particle size less than 500 microns. The dental products of the invention include a polymerizable composition in an enclosure having at least two chambers separated by a wall adapted to be ruptured prior to or during mixing of the composition. Compositions of the invention are preferred for use in these enclosures. Core build up material including a polymerizable acid containing compound is used to support dental crowns and adhere them to teeth in accordance with the invention.

Abstract: .epsilon.-Caprolactam is continuously recovered from carpet made from nylon 6 face fibers and a backing. The carpet is fed to a separator to prepare scrap containing nylon 6 and auxiliary materials. The scrap from the separator is fed to a depolymerizing reactor to produce an .epsilon.-caprolactam containing distillate and more auxiliary materials. The .epsilon.-caprolactam in the distillate is separated from other volatiles and purified. The auxiliary materials are also recovered or re-used.

Abstract: Biodegradable polymeric therapeutic implant materials incorporating bioactive ceramics such as Bioglass.RTM. ceramic are provided. These implants provide increased mechanical properties and pH control, enabling the use of these materials to design porous and nonporous therapeutic implants used as cell scaffolds for healing of tissue defects or fixation devices, having desired degradation times, mechanical properties, elasticity and biocompatibility.

Abstract: The invention provides dental composition system having curable liquid which is useful alone as a light curable composition and which is useful by mixing with a powder in preselected proportions to form dual cure compositions. The composition system is useful as bonding agent, cement, liner, base, restorative, pit and fissure sealants, and/or core build-up material, having improved adhesion to dentin. After storing the powder and the liquid in separate containers for at least two weeks and then mixing a portion of the powder and a portion of the liquid to form a mixture, the polymerizable compound polymerizes within 20 minutes of the mixing to form a first polymeric material having a flexural strength of at least 50 MPa, and an expansion in water at 37.degree. C. after 90 days of less than 1 percent by volume.

Abstract: A dental resin composition is presented, comprising an ethoxylated bisphenol A dimethacrylate having the formulaCH.sub.2 .dbd.C(CH.sub.3)CO.sub.2 (C.sub.2 H.sub.4 O).sub.x C.sub.6 H.sub.4 C(CH.sub.3) .sub.2 C.sub.6 H.sub.4 (OC.sub.2 H.sub.4).sub.y O.sub.2 CC(CH.sub.3).dbd.CH.sub.2wherein x+y is an integer from 1 to 20, and preferably from 2 to 7, together with a methacrylate oligomer and an optional diluent monomer. The composition is suitable for use for dental fillers adhesives, and the like, and has improved water sorption and excellent wear resistance.

Abstract: This invention provides a composition for anchoring materials in or to concrete or masonry. The composition comprises an alkylacrylate ester monomer, an alkylacrylate ester/methacrylic acid copolymer, a free-radical catalyst and a filler.

Abstract: A two paste glass ionomer type dental cement system, with both pastes being, preferably, of similar consistency. The first paste represents primarily a suspension of an inert filler in a water solution of polyacrylic acid, or its copolymers with other ethylenically unsaturated acids, having molecular weight of 25,000 to 100,000 and, optionally, various additives, such as filler suspending agents, coloring agents, agents influencing working/setting time (retardants or accelerators), Theological agents, pH modifiers, etc. The other paste represents primarily a particulate glass flux containing silicon and aluminum oxides, calcium fluoride and, optionally, other inorganic salts, including aluminum phosphate, and sodium, barium and aluminum fluorides, suspended in a liquid medium consisting primarily of a water solution of a hydrophilic acrylic monomer or polymer. In order to achieve a desirable consistency, organic or inorganic thickening agents may be added in suitable quantities.

Abstract: An ophthalmic lens suited for extended-wear periods of at least one day on the eye without a clinically significant amount of corneal swelling and without substantial wearer discomfort. The lens has a balance of oxygen permeability and ion or water permeability, with the ion or water permeability being sufficient to provide good on-eye movement, such that a good tear exchange occurs between the lens and the eye. A preferred lens is a copolymerization product of a oxyperm macromer and an ionoperm monomer. The invention encompasses extended wear contact lenses, which include a core having oxygen transmission and ion transmission pathways extending from the inner surface to the outer surface.

Abstract: The invention relates to impact-resistant injection mouldings based on polyamide resin (A) and on a disperse phase whose particles have a number-average diameter greater than 0.4 .mu.m, a volume-average diameter greater than 1 .mu.m and such that more than 50% by volume of the particles are larger than 1 .mu.mThe disperse phase may consist of a mixture including at least one copolymer (B) of ethylene and of an unsaturated epoxide and of at least one polyolefin (C).

Abstract: A method for producing moisture-containing soft contact lenses by polymerizing monomers for contact lenses in the presence of a diluent for monomers and substituting the diluent contained in the resulting polymer with an aqueous solution, wherein the diluent is composed of one or more compounds selected from the group consisting of triethylene glycol, diethylene glycol monomethyl ether and triethylene glycol monomethyl ether and a moisture-containing contact lens composed of a copolymer of the following main components, (1) two or more kinds of hydrophilic monomers selected from the group consisting of 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone and N,N-dimethylacrylamide, (2) an alkyl methacrylate and (3) a crosslinkable monomer, and an aqueous solution, which has a moisture content of 50-70% and exhibits a penetration strength of 1100 gf/mm or more. The contact lens of the present invention is optically transparent and exhibit excellent mechanical strength.

Abstract: Poly(dialkylaminoalkyl (meth)acrylamide)-based superabsorbent gels are disclosed. The superabsorbent gels either comprise a mixture of a poly(dialkylaminoalkyl (meth) acrylamide) polymer and an acidic water-absorbing polymer, like polyacrylic acid, or comprise a salt of a poly(dialkylaminoalkyl (meth)acrylamide) polymer. An improved method of preparing an N-(dialkylaminoalkyl) (meth)acrylamide monomer also is disclosed.

Abstract: A dental filling resin composition is disclosed, comprising: a reaction product between an aluminosilicate glass powder containing at least one element selected from Ca, Sr, and Ra and an organic acid containing one or more carboxyl groups in one molecule thereof, a methanol-insoluble polymer, a monomer containing at least one unsaturated double bond and having no acidic group, and a polymerization initiator, and optionally a filler.The dental filling resin composition of the invention has not only superior mechanical characteristics and esthetics but also an ability to release a fluorine ion and therefore, can be suitably used for a wide variety of clinical applications such as filling restoration of tooth, core construction, or sealing of pit and fissure.

Abstract: The presently claimed invention comprises a biopolymer nanoparticle for drug delivery wherein the nanoparticle comprises a homogeneous blend of an aliphatic polyester polymer blended with a polyether, a lipophilic or polypeptide drug and a biocompatible cholesterol interacting agent for preserving the activity of the drug administered to the patient while at the same time controlling the release of the drug. Methods for making the homogeneous drug delivery nanoparticles are also disclosed.

Abstract: Composites suitable for use as prostheses for attachment to soft tissues, such as cartilage, tendons, skin, tympanic membrane and gingiva, as well as to cancellous or trabecular bone, are based on combination of a polyolefinic binder with certain bioactive glass materials. The composites bond actively with soft tissues and are readily formulated achieve mechanical properties comparable to those of the soft tissue of interest.