Heat-sensitive recording material having intermediate layer that contains hollow particles

A heat-sensitive recording body comprising:

• a support;
• an intermediate layer;
• and
• a heat-sensitive color forming layer,.
• wherein the heat-sensitive color forming layer comprises as main components:
• a leuco dye;
• and
• a developer,
• the intermediate layer and the heat-sensitive color forming layer are stacked on the support in this order,
• the intermediate layer comprises a hollow particle,
• the hollow particle comprises:
• a hollow core portion;
• and
• a resin portion,
• wherein the hollow core portion is formed by drying a solvent in an alkali-swellable aqueous gel,
• the alkali-swellable aqueous gel comprises:
• a (meth)acrylic-based copolymer having an acid value in a range from 200 to 400 mgKOH/g,
• the (meth)acrylic-based copolymer is a copolymer formed from a monomer mixture comprising:
• (a1) a C1-3 aliphatic alkyl (meth)acrylate;
• (a2) a carboxyl group-containing monomer;
• and
• (a3) at least one monomer selected from the group consisting of n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, cyclodecyl (meth)acrylate, cyclodecylmethyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and isobornyl (meth)acrylate,
• the resin portion encapsulates the core portion and has a non-alkali-swellable layer as an outermost layer of the hollow particle, wherein the non-alkali-swellable outermost layer is formed from a material comprising a hydrophobic monomer, and
• the hollow particle has an average particle diameter in a range from 1.5 to 3.5 μm and a percentage of hollowness in a range from 60 to 85%.