A rubbery composition is prepared by combining (A) a rubber component, (B) a cellulose, and (C) fluorene compound having a 9,9-bis(aryl)fluorene skeleton. The fluorene compound (C1) may be a compound represented by the following formula (1):

##STR00001##

wherein a ring Z represents an arene ring, R.sup.1 and R.sup.2 represent a substituent, X.sup.1 represents a heteroatom-containing functional group, k denotes an integer of 0 to 4, n denotes an integer of not less than 1, p denotes an integer of not less than 0. The rubbery composition has improved mechanical properties such as strength, elongation, and hardness.

A partially annulated flexible tubular structure located at least partially inside the fuel tank, of a vehicle, the structure being capable of being at least partially submerged in the tank and being intended for transporting the fuel into the tank, the tubular structure including at least one layer (1) including a composition including: a. between 39% and 100% by weight, in particular between 41% and 100% by weight, of at least one aliphatic polyamide of formula W/Z, b. between 0% and 4% by weight, and preferably between 0 and 2%, of at least one plasticizer, c. between 0% and 20% of at least one impact modifier, d. between 0% and 37% by weight of at least one additive, the sum of a.+b.+c.+d. being equal to 100% of the total weight of the composition, excluding a fuel transport structure running from the tank to the motor of the vehicle.

The invention relates to the use of at least one catalyst, at least one copper heat stabiliser and at least one oligo- or poly-carbodiimide with a matrix including at least one polyamide, in order to form a composition that has a good melt viscosity and is stable during transformation, in particular during extrusion.

The invention relates to the use of at least one catalyst, at least one copper heat stabiliser and at least one oligo- or poly-carbodiimide with a matrix including at least one polyamide, in order to form a composition that has a good melt viscosity and is stable during transformation, in particular during extrusion.

A fluorine-containing copolymer including tetrafluoroethylene units (a), ethylene units (b), and hexafluoropropylene units (c), a content of the tetrafluoroethylene units (a) in the total monomer units being 36.0 to 45.0% by mole; a content of the hexafluoropropylene units (c) in the total monomer units being 6 to 21% by mole; a mole ratio of the tetrafluoroethylene units (a) to the sum of the tetrafluoroethylene units (a) and the ethylene units (b), (a)/((a)+(b)), being 0.40 to 0.54; and a melt flow rate measured under the conditions of 230° C. and a load of 5 kg being 12 to 100 g/10 minutes.

A device for repairing pipe leakage takes the form of a short section of PVC pipe with fittings. The pipe is ideally a 1′-2′ section fashioned into a U-bend with a substantially semi-circular bend and two arms, and the fittings take the form of an elbow joint glued onto each arm. The arms are ideally offset up to 5° from parallel. A method of repairing cracked PVC piping using the device involves cutting out a 4″-6″ section of piping, gluing the exposed ends of the broken piping as well as the elbow joints, squeezing the U-bend, positioning the squeezed device into the gap in broken piping, and releasing the U-bend to fit the elbow joints over the exposed ends of broken piping. The device has no vulnerable moving parts or O-rings, and it obviates the need to remove entire pipes.

A device for repairing pipe leakage takes the form of a short section of PVC pipe with fittings. The pipe is ideally a 1′-2′ section fashioned into a U-bend with a substantially semi-circular bend and two arms, and the fittings take the form of an elbow joint glued onto each arm. The arms are ideally offset up to 5° from parallel. A method of repairing cracked PVC piping using the device involves cutting out a 4″-6″ section of piping, gluing the exposed ends of the broken piping as well as the elbow joints, squeezing the U-bend, positioning the squeezed device into the gap in broken piping, and releasing the U-bend to fit the elbow joints over the exposed ends of broken piping. The device has no vulnerable moving parts or O-rings, and it obviates the need to remove entire pipes.

Provided is piping for ultra-pure water from which the amount of calcium leaching can be suppressed to an extent that satisfies the quality required for ultra-pure water, and which can be produced so as to be provided with mechanical properties.

[Solution] This piping for ultra-pure water is used for conveying ultra-pure water and includes a first polyolefin-based resin layer constituting the innermost layer, and a second polyolefin-based resin layer disposed on the outer side of the first polyolefin-based resin layer, wherein the calcium concentration within the first polyolefin-based resin layer is 10 ppm or lower, and the calcium concentration within the second polyolefin-based resin layer is between 20 ppm and 200 ppm inclusive. With this constitution, the amount of calcium leaching can be suppressed to an extent that satisfies the quality required for ultra-pure water, and the piping can be produced so as to be provided with mechanical properties.

The present invention provides a hose excellent in mechanical properties at high temperatures. The hose of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E″ of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).

The present invention provides a hose excellent in mechanical properties at high temperatures. The hose of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E″ of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).