Abstract: A high volume organic solvent polymer dispersion that is prepared by dispersing a hydrolysable polymer in a non-volatile water-soluble organic solvent, has a water content of not more than 1 mass %, and has a falling time at 50° C. of not more than 120 seconds which is measured by a Zahn cup with an orifice diameter of not more than 5 mm. Also disclosed is a method of using the high volume organic solvent polymer dispersion, which includes feeding the high volume organic solvent polymer dispersion into the ground.

Abstract: A polylactic acid solid composition includes: a polylactic acid having a weight average molecular weight of not more than 40,000, which is measured in terms of polystyrene standard by GPC; and a basic compound of an alkali metal or an alkaline earth metal, which is a residue of a molecular weight reduction accelerator. The basic compound is contained in an amount in a range of 0.5 to 20 mass %.

Abstract: A method of producing a polyoxalate copolymer using, as a diol component, an ethylene glycol and other diol in combination, and subjecting the diol component and a dimethyl oxalate to an esterification polymerization reaction. The esterification polymerization reaction is executed through a step that includes: a step of a normal-pressure polymerization inclusive of the esterification polymerization reaction of a oxalic acid formed from the dimethyl oxalate and the ethylene glycol, and a step of a reduced-pressure polymerization that is accompanied by a removal of diol after the step of the normal-pressure polymerization. Further, the other diol is added to the polymerization system at a predetermined temperature in the step of the normal-pressure polymerization.

Abstract: A polylactic acid copolymer having more improved hydrolizability and hydrophilic property than those of the polylactic acid. The polylactic acid copolymer is obtained by the copolymerization of a polylactic acid with an acid-releasing ester polymer capable of releasing an acid other than the lactic acid upon the hydrolysis. The polylactic acid copolymer has a quantity of heat of fusion ?H of not more than 20 J/g as measured by using the DSC when the temperature is elevated the second time, contains the copolymer units stemming from the acid-releasing ester polymer in an amount of 0.5 to 35% by mass, and has a weight average molecular weight in a range of 15,000 to 40,000.

Abstract: A method of extracting underground resources including a step of mixing hydrolysable particles and a proppant to an aqueous dispersion fluid, and introducing the fluid with pressure into an ore chute formed under the ground, wherein as the hydrolysable particles, use is made of spherical particles that include a hydrolysable resin of a weight average molecular weight (Mw) of not less than 5,000 and, specifically, not less than 10,000, and that have an average particle size (D50) in a range of 300 to 1,000 ?m, and a circularity of a short diameter/long diameter ratio of not less than 0.8. The spherical particles have a hyrolysable capability, a circularity and a particle size adapted to the hydraulic fracturing.

Abstract: A polylactic acid composition of a dispersion structure using, as a matrix, a lowly crystalline or amorphous polylactic acid having a crystallinity of not more than 40%, the matrix containing, as a pulverization promotor dispersed therein, an organically modified polysaccharide or a lamellar silicate that is swollen or that is treated to be swollen. The polylactic acid composition has excellent hydrolysable capability and property of being mechanically pulverized.

Abstract: A method of extracting the underground resources by pressurizing a fluid filled in an ore chute in which cracks are formed and by, further, forming or growing the cracks, the underground resources being extracted through the cracks, wherein a hydrolysis-blocking agent is introduced with pressure into the fluid to block a diverting agent that works to temporarily close the cracks.

Abstract: A powder comprising hydrolyzable resin particle, containing particles which do not pass through a sieve having an opening size of 500 ?m in an amount of 50 mass % or more and having a repose angle of 51° or more. This powder is preferably used as an additive for drilling to enhance the drilling properties of a drilling fluid and improve the retentivity of a fracture extending from a winze.

Abstract: A polyoxalate copolymer including an acid-constituting unit derived from an oxalic acid and a diol-constituting unit derived from a diol component, the diol-constituting unit being derived from a combination of an ethylene glycol and other diols, and having a temperature differential between a 5% weight loss temperature as measured by the TG-DTA and a melting point thereof in a range of 50 to 80° C.

Abstract: A dispersion solution for drilling obtained by dispersing, in an aqueous medium, a hydrolysable resin material that contains a resin that is hydrolysable but sparingly and a hydrolysable resin that accelerates the decomposition of esters. The dispersion solution for drilling exhibits a highly hydrolysable capability despite of using an inexpensive hydrolysable resin material, and can be favorably used for extracting resources relying on a well drilling method such as hydraulic fracturing method, rotary drilling method or riserless drilling method.

Abstract: An object of the present invention is to provide a method for efficiently degrading a biodegradable resin. In particular, the present invention relates to a method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present.

Abstract: A method of extracting underground resources including a step of mixing hydrolysable particles and a proppant to an aqueous dispersion fluid, and introducing the fluid with pressure into an ore chute formed under the ground, wherein as the hydrolysable particles, use is made of spherical particles that include a hydrolysable resin of a weight average molecular weight (Mw) of not less than 5,000 and, specifically, not less than 10,000, and that have an average particle size (D50) in a range of 300 to 1,000 ?m, and a circularity of a short diameter/long diameter ratio of not less than 0.8. The spherical particles have a hyrolysable capability, a circularity and a particle size adapted to the hydraulic fracturing.

Abstract: A polyoxalate copolymer that includes main ester units of oxalate linked together like a straight chain, and branched ester copolymer units derived from a trifunctional or more highly functional alcohol or an acid. The polyoxalate copolymer initially undergoes the hydrolysis in a suppressed manner.

Abstract: A method of extracting the underground resources by pressurizing a fluid filled in an ore chute in which cracks are formed and by, further, forming or growing the cracks, the underground resources being extracted through the cracks, wherein a hydrolysis-blocking agent is introduced with pressure into the fluid to block a diverting agent that works to temporarily close the cracks.

Abstract: A powder comprising hydrolyzable resin particle, containing particles which do not pass through a sieve having an opening size of 500 ?m in an amount of 50 mass % or more and having a repose angle of 51° or more. This powder is preferably used as an additive for drilling to enhance the drilling properties of a drilling fluid and improve the retentivity of a fracture extending from a winze.

Abstract: An object of the present invention is to provide a method for efficiently degrading a biodegradable resin. In particular, the present invention relates to a method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present.

Abstract: A method of decomposing an ester resin with an enzyme by making present an ester decomposition promotor, an enzyme and an enzyme adsorption-suppressing compound in an aqueous medium that contains the ester resin. The decomposition method is capable of decomposing, at a low temperature maintaining reliability and stability, the ester resin added to a dispersion solution for drilling, such as fracturing fluid.

Abstract: An object of the present invention is to provide a method for efficiently degrading a biodegradable resin. In particular, the present invention relates to a method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present.

Abstract: A formed body of resin for throwing into water, having a dispersion structure in which a hydrolysable resin is dispersed in a matrix of a water-soluble resin. The formed body of resin can facilitate the operation for mixing into water without impairing properties of the hydrolysable resin.

Abstract: A polylactic acid composition of a dispersion structure using, as a matrix, a lowly crystalline or amorphous polylactic acid having a crystallinity of not more than 40%, the matrix containing, as a pulverization promotor dispersed therein, an organically modified polysaccharide or a lamellar silicate that is swollen or that is treated to be swollen. The polylactic acid composition has excellent hydrolysable capability and property of being mechanically pulverized.