Abstract: To provide a rubber stopper capable of suppressing occurrence of coring. Provided is a rubber stopper including a canopy portion having an upper surface and a lower surface, and a leg portion provided on the lower surface of the canopy portion, in which the leg portion has a tapered base portion at the center on a lower surface side of the canopy portion, and a curvature radius R1 of the tapered base portion is 2 mm or more and 4 mm or less.

Abstract: A piston for a syringe can be easily formed by using a mold and can achieve both a high sealing performance and a low sliding resistance value. A piston is used by being inserted into a syringe barrel including an approximately cylindrical elastic body. A side surface includes plural annular protrusions in the axial direction. A maximum diameter part of the annular protrusions has an outer diameter which is to be contacted with an inner surface of the syringe barrel when the piston is inserted into the syringe barre. A maximum diameter part of at least one annular protrusion is formed at a position which is shifted from the halfway of the axial length of the annular protrusion toward the bottom surface side.

Abstract: A curable resin composition that is adhesive and transparent. The curable resin composition comprises (1) a polymerizable vinyl monomer, (2) a curing agent, (3) a reducing agent, and (4) an acrylic block copolymer having a structure represented by formula (1): [a1]-[b]-[a2]??(1) wherein [a1] and [a2] each independently represents a polymer block which consists mainly of structural units derived from an alkyl acrylate and/or an alkyl methacrylate and has a glass transition temperature of 90° C. or higher, and [b] represents a polymer block which consists mainly of structural units derived from an alkyl acrylate and/or an alkyl methacrylate and has a glass transition temperature of ?10° C. or lower, the copolymer satisfying the relationship (total mass of [a1] and [a2]/(mass of [b])=5/95 to 80/20.

Abstract: A curable resin composition that is adhesive and transparent. The curable resin composition comprises (1) a polymerizable vinyl monomer, (2) a curing agent, (3) a reducing agent, and (4) an acrylic block copolymer having a structure represented by formula (1): [a1]-[b]-[a2] (1) wherein [a1] and [a2] each independently represents a polymer block which consists mainly of structural units derived from an alkyl acrylate and/or an alkyl methacrylate and has a glass transition temperature of 90° C. or higher, and [b] represents a polymer block which consists mainly of structural units derived from an alkyl acrylate and/or an alkyl methacrylate and has a glass transition temperature of ?10° C. or lower, the copolymer satisfying the relationship (total mass of [a1] and [a2]/(mass of [b])=5/95 to 80/20.

Abstract: A curable resin composition comprising (1) a polymerizable vinyl monomer, (2) a polymerization initiator, (3) an aromatic amine and/or a pyridine derivative, (4) a &bgr;-diketone elate and/or a &bgr;-keto-ester, and (5) a phosphate.

Abstract: A curable resin composition comprising (1) a polymerizable vinyl monomer, (2) a polymerization initiator, (3) an aromatic amine and/or a pyridine derivative, (4) a .beta.-diketone chelate and/or a .beta.-keto-ester, and (5) a phosphate.

Abstract: A curable resin composition comprising:(1) a polymerizable vinyl monomer having a structure of the formula (A):Z--R--(R.sub.2 O).sub.p --R.sub.1 (A)wherein Z is a (meth)acryloyl group, R.sub.1 is a phenyl group or a phenyl group having a C.sub.1-3 alkyl group, R.sub.2 is --C.sub.2 H.sub.4 --, --C.sub.3 H.sub.6 --, --CH.sub.2 CH(CH.sub.3)--, --C.sub.4 H.sub.8 -- or --C.sub.6 H.sub.12 --, and p is an integer of from 1 to 10 and wherein R is a direct bond,(2) a polymerizable vinyl monomer having a structure of the formula (B): ##STR1## wherein Z and R.sub.2 are as defined above, R.sub.3 is hydrogen or a C.sub.1-4 alkyl group, and q is an integer of from 0 to 8,(3) a polymerizable vinyl monomer having a structure of the formula (C):Z--O--(R.sub.2 O).sub.p --H (C)wherein Z, R.sub.2 and p are as defined above,(4) an organic peroxide, and(5) a reducing agent.

Abstract: An adhesive composition comprising a first liquid containing (A) an acrylic compound selected from the group consisting of (meth)acrylic acids and esters thereof, and (B) a polymerization initiator selected from the group consisting of peroxy esters and hydroperoxides, and a second liquid containing (C) a condensation product of an amine and an aldehyde, and (D) a copper salt, wherein an acid phosphate compound of the following formula (I): ##STR1## wherein R is an alkyl group, an alkoxyalkyl group or a CH.sub.2 .dbd.CR.sub.1 --CO(OR.sub.2).sub.m -- group, wherein R.sub.1 is H or CH.sub.3, R.sub.2 is --C.sub.2 H.sub.4 --, --C.sub.3 H.sub.6 --, ##STR2## --C.sub.4 H.sub.8 --, --C.sub.6 H.sub.12 -- or ##STR3## and m is an integer of from 1 to 10; and n is 1 or 2, is contained in the first liquid or in both the first and second liquids.