The resin composition of the present invention is a resin composition containing: a bismaleimide compound (A) containing a constituent unit represented by the following formula (1) and maleimide groups at both ends of the molecular chain; a compound (B) containing one or more carboxy groups; and a photo initiator (C). ##STR00001##
In the formula (1), R.sub.1 represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. R.sub.2 represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. Each R.sub.3 independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 16 carbon atoms, or a linear or branched alkenyl group having 2 to 16 carbon atoms. Each n independently represents an integer of 1 to 10.

The present invention provides a resin composition for producing an encapsulating member having high heat resistance and high encapsulation performance. In the resin composition for encapsulating a light-emitting device according to the present invention, at least one of (i) and (ii) is satisfied: (i) the resin composition includes a polymer (P1) including: a structural unit (A) represented by the following formula (1); and a structural unit (B) having at least one functional group selected from the group consisting of a carbonyl-containing group, a hydroxyl group, an epoxy group, an isocyanate group, and a cyano group; and (ii) the resin composition includes: a polymer (P2) including the structural unit (A); and a polymer (P3) including the structural unit (B).

##STR00001##

The present invention provides a resin composition for producing an encapsulating member having high heat resistance and high encapsulation performance. In the resin composition for encapsulating a light-emitting device according to the present invention, at least one of (i) and (ii) is satisfied: (i) the resin composition includes a polymer (P1) including: a structural unit (A) represented by the following formula (1); and a structural unit (B) having at least one functional group selected from the group consisting of a carbonyl-containing group, a hydroxyl group, an epoxy group, an isocyanate group, and a cyano group; and (ii) the resin composition includes: a polymer (P2) including the structural unit (A); and a polymer (P3) including the structural unit (B).

##STR00001##

Provided is a polymer composition having sufficient heat resistance and optical characteristics. Disclosed is a polymer composition comprising a polymer containing a monomer unit having a ring structure, wherein the polymer composition is, for instance, polymer composition A containing a polymer of a monomer having a ring structure, and when a flat plate of 120 mm×100 mm×3.0 mm in thickness is molded from the polymer composition under the following injection molding conditions of: (1) using a non-vent-type injection molding machine; (2) using a cold runner mold; (3) having a cylinder temperature of 260° C.; and (4) having a ratio of an injection volume of the injection molding machine to a molded product volume of 4.5, a difference between a monomer content in the flat plate obtained at a cooling time of 5 min and a monomer content in the flat plate obtained at a cooling time of 1 min is 1000 ppm by mass or more and 12000 ppm by mass or less.

Provided is a polymer composition having sufficient heat resistance and optical characteristics. Disclosed is a polymer composition comprising a polymer containing a monomer unit having a ring structure, wherein the polymer composition is, for instance, polymer composition A containing a polymer of a monomer having a ring structure, and when a flat plate of 120 mm×100 mm×3.0 mm in thickness is molded from the polymer composition under the following injection molding conditions of: (1) using a non-vent-type injection molding machine; (2) using a cold runner mold; (3) having a cylinder temperature of 260° C.; and (4) having a ratio of an injection volume of the injection molding machine to a molded product volume of 4.5, a difference between a monomer content in the flat plate obtained at a cooling time of 5 min and a monomer content in the flat plate obtained at a cooling time of 1 min is 1000 ppm by mass or more and 12000 ppm by mass or less.

Provided is a polymer composition having sufficient heat resistance and optical characteristics. Disclosed is a polymer composition comprising a polymer containing a monomer unit having a ring structure, wherein the polymer composition is, for instance, polymer composition A containing a polymer of a monomer having a ring structure, and when a flat plate of 120 mm×100 mm×3.0 mm in thickness is molded from the polymer composition under the following injection molding conditions of: (1) using a non-vent-type injection molding machine; (2) using a cold runner mold; (3) having a cylinder temperature of 260° C.; and (4) having a ratio of an injection volume of the injection molding machine to a molded product volume of 4.5, a difference between a monomer content in the flat plate obtained at a cooling time of 5 min and a monomer content in the flat plate obtained at a cooling time of 1 min is 1000 ppm by mass or more and 12000 ppm by mass or less.

A resin composition for injection molding or compression molding using an ethylene-based ionomer is excellent in impact strength, heat resistance, long-term durability, etc. The resin composition includes an ionomer in which, in a copolymer (P) containing a structural unit (A) derived from ethylene and/or an α-olefin having 3 to 20 carbon atoms, and a structural unit (B) derived from a monomer having a carboxyl group(s) and/or a dicarboxylic anhydride group(s) as essential constitutional units, at least a part of the carboxyl groups and/or the dicarboxylic anhydride groups in the copolymer (P) being converted into a metal-containing carboxylic acid salt(s) containing at least one kind of a metal ion(s) selected from Group 1, Group 2 or Group 12 of the periodic table, and has a phase angle S at an absolute value G*=0.1 MPa of a complex modulus of elasticity measured by a rotary rheometer of 50 degrees to 75 degrees.

A resin composition for injection molding or compression molding using an ethylene-based ionomer is excellent in impact strength, heat resistance, long-term durability, etc. The resin composition includes an ionomer in which, in a copolymer (P) containing a structural unit (A) derived from ethylene and/or an α-olefin having 3 to 20 carbon atoms, and a structural unit (B) derived from a monomer having a carboxyl group(s) and/or a dicarboxylic anhydride group(s) as essential constitutional units, at least a part of the carboxyl groups and/or the dicarboxylic anhydride groups in the copolymer (P) being converted into a metal-containing carboxylic acid salt(s) containing at least one kind of a metal ion(s) selected from Group 1, Group 2 or Group 12 of the periodic table, and has a phase angle S at an absolute value G*=0.1 MPa of a complex modulus of elasticity measured by a rotary rheometer of 50 degrees to 75 degrees.

A Polymer used as a pesticide means, having an acid number greater than 100. The Polymer has a valent metal ion which is bonded to at least one reactive group. The characteristics of the Polymer include, conductivities of 4 S/cm to 200 S/cm or more, depending upon the concentration and nature of the metal bound. The conductivity proportional to the amount of metal bound, the ability of the Polymer to bind metals having a +1, +2, +3, +4, or +5 valence charge to the Polymer, and the ability to bind two or more different metals to separate binding sites on the Polymer.

A Polymer used as a pesticide means, having an acid number greater than 100. The Polymer has a valent metal ion which is bonded to at least one reactive group. The characteristics of the Polymer include, conductivities of 4 S/cm to 200 S/cm or more, depending upon the concentration and nature of the metal bound. The conductivity proportional to the amount of metal bound, the ability of the Polymer to bind metals having a +1, +2, +3, +4, or +5 valence charge to the Polymer, and the ability to bind two or more different metals to separate binding sites on the Polymer.