Provided is a laser welded body which can be manufactured without undergoing complicated steps and maintain the characteristics of a resin contained in a resin member, which exhibits high welding strength even when scanned with a laser beam at a high speed, and which can be manufactured at high production efficiency.

The laser welded body 10 comprises a first resin member 1 which is a laser-irradiated subject which contains a thermoplastic resin and nigrosine sulfate and has an absorbance a.sub.1 of 0.09 to 0.9; and a second resin member 2 which contains a thermoplastic resin as the same kind as or different kind from the thermoplastic resin and a laser beam absorbent, and has an absorbance a.sub.2 of 3.0 to 15, wherein the first resin member 1 and the second resin member 2 are laser-welded at a part at which the both resin members are overlapped and/or butted.

An epoxy-based insulation material and a method of thermally insulating a subsea production apparatus are disclosed. The epoxy-based insulation material has an amine-cured epoxy elastomer matrix and a plurality of non-metallic beads suspended in the matrix. The epoxy-based insulation material is located on the subsea production apparatus to thermally insulate a hydrocarbon fluid from sea water.

An epoxy-based insulation material and a method of thermally insulating a subsea production apparatus are disclosed. The epoxy-based insulation material has an amine-cured epoxy elastomer matrix and a plurality of non-metallic beads suspended in the matrix. The epoxy-based insulation material is located on the subsea production apparatus to thermally insulate a hydrocarbon fluid from sea water.

To provide a composition having a very low refractive index, an organic photoelectronic element using the composition, and simple methods for producing such a composition and an organic photoelectronic element.

A composition comprising a fluorinated polymer, an organic semiconductor material and a dopant.

To provide a composition having a very low refractive index, an organic photoelectronic element using the composition, and simple methods for producing such a composition and an organic photoelectronic element.

A composition comprising a fluorinated polymer, an organic semiconductor material and a dopant.

A precursor composition which can produce a polyimide film with excellent light transmittance, mechanical properties, coefficient of linear thermal expansion and resistance to thermal decomposition; and a polyimide film obtained from the precursor composition. The polyimide precursor composition contains a polyimide precursor with a repeating unit represented by formula (I); an imidazole compound in an amount more than 0.01 mol and 2 mol or less based on one mol of the repeating units of the polyimide precursor, and a solvent.

##STR00001##

In general formula I, 70 mol. % or more of X.sub.1 is a structure represented by formula (1-1):

##STR00002##

and 70 mol % or more of Y.sub.1 is a structure represented by formula (D-1) and/or (D-2):

##STR00003##

A precursor composition which can produce a polyimide film with excellent light transmittance, mechanical properties, coefficient of linear thermal expansion and resistance to thermal decomposition; and a polyimide film obtained from the precursor composition. The polyimide precursor composition contains a polyimide precursor with a repeating unit represented by formula (I); an imidazole compound in an amount more than 0.01 mol and 2 mol or less based on one mol of the repeating units of the polyimide precursor, and a solvent.

##STR00001##

In general formula I, 70 mol. % or more of X.sub.1 is a structure represented by formula (1-1):

##STR00002##

and 70 mol % or more of Y.sub.1 is a structure represented by formula (D-1) and/or (D-2):

##STR00003##

A rubber composition includes an ethylene-propylene-diene base terpolymer (EPDM) and exhibits advantageous aging properties in a high temperature environment. For example, it retains at least 30% of elongation at break and/or at least 70% tensile strength after heat aging at 350? F. for 504 hours; or it retains at least 50% of elongation at break and at least 70% tensile strength after heat aging at 392? F. for 70 hours. Such excellent heat aging performance has qualified HEATBOSS? EPDM for type E applications or basic F application per SAE J200 or ASTM D2000. The diene of the EPDM may be 5-vinylidene-2-norbornene (VNB), 5-methyl-ene-2-norbornene (MVNB), or another diene having a peroxide crosslinking efficiency (E) of at least 1.

A rubber composition includes an ethylene-propylene-diene base terpolymer (EPDM) and exhibits advantageous aging properties in a high temperature environment. For example, it retains at least 30% of elongation at break and/or at least 70% tensile strength after heat aging at 350? F. for 504 hours; or it retains at least 50% of elongation at break and at least 70% tensile strength after heat aging at 392? F. for 70 hours. Such excellent heat aging performance has qualified HEATBOSS? EPDM for type E applications or basic F application per SAE J200 or ASTM D2000. The diene of the EPDM may be 5-vinylidene-2-norbornene (VNB), 5-methyl-ene-2-norbornene (MVNB), or another diene having a peroxide crosslinking efficiency (E) of at least 1.

The present invention relates to the use of N-hydroxybenzotriazole derivatives, in particular N-hydroxybenzotriazole salts and/or N-hydroxyindazoles, in particular N-hydroxyindazole salts as flame retardant for plastic materials. The present invention relates in addition to a flame-retardant plastic material molding compound which comprises N-hydroxybenzotriazole derivatives and/or N-hydroxyindazole derivatives as flame retardant.