Water-based adhesive compositions are improved by the incorporation of hollow polymeric microspheres having outer surfaces coated with one or more barrier materials such as calcium carbonate particles. The adhesive compositions exhibit enhanced rheology, sprayability, drying time, tack and storage stability as compared to analogous adhesives that are not modified with coated hollow polymeric microspheres. Such compositions are useful as both contact adhesives as well as wet bonding one-way adhesives.

A frictional power transmission belt is provided, containing an adhesion rubber layer in contact with at least a portion of a tension member extending in a longitudinal direction of the belt, in which the adhesion rubber layer is formed of a first vulcanized rubber composition containing a rubber component and a filler, the filler contains substantially no silica and contains 30 parts by mass or more of carbon black based on 100 parts by mass of the rubber component, and the tension member has, on a surface thereof, an overcoat layer formed of a second vulcanized rubber composition containing a rubber component and silica.

Provided is a chloroprene-based polymer having an industrially applicable sufficient molecular weight and capable of obtaining a vulcanized rubber excellent in durability and fatigue endurance and an adhesive excellent in layer separation resistance. A chloroprene-based polymer having a number average molecular weight Mn of 150000 to 300000 and comprising a functional group of a structure represented by the general formula (1) or (2) below: ##STR00001##
(wherein in the general formula (1), R1 shows hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclyl group.)

An adhesive composition comprising a solids component, said solids component including a rubber component that includes polychloroprene; and a solvent component, said solvent component including t-butyl acetate.

An adhesive composition comprising a solids component, said solids component including a rubber component that includes polychloroprene; and a solvent component, said solvent component including t-butyl acetate.

An adhesive composition comprising a solids component, said solids component including a rubber component that includes polychloroprene; and a solvent component, said solvent component including t-butyl acetate.

A laminate comprising a substrate layer; a contact adhesive layer comprising a contact adhesive agent having at least one of chloroprene rubber or acrylic copolymers, as well as microspheres having an average particle size of 0.5 μm or greater in the contact adhesive layer, wherein the contact adhesive layer contains from 5 parts by mass to 500 parts by mass of the microspheres per 100 parts by mass of the contact adhesive agent, and the contact adhesive layer has a plurality of protruding portions because of the the microspheres.

A laminate comprising a substrate layer; a contact adhesive layer comprising a contact adhesive agent having at least one of chloroprene rubber or acrylic copolymers, as well as microspheres having an average particle size of 0.5 μm or greater in the contact adhesive layer, wherein the contact adhesive layer contains from 5 parts by mass to 500 parts by mass of the microspheres per 100 parts by mass of the contact adhesive agent, and the contact adhesive layer has a plurality of protruding portions because of the the microspheres.

In an embodiment a solvent composition can comprise, based on the total volume of the solvent composition, 10 to 95 volume percent of a first solvent, wherein the first solvent has Hansen solubility parameters of: 15 MPa.sup.0.5≤δ.sub.D≤17 MPa.sup.0.5, 4≤δ.sub.P≤10.5 MPa.sup.0.5, and 7≤δ.sub.H≤10 MPa.sup.0.5; 5 to 95 volume percent of a second solvent, wherein the second solvent has Hansen solubility parameters of: 16 MPa.sup.0.5≤δ.sub.D≤17.5 MPa.sup.0.5, 0≤δ.sub.P≤3 MPa.sup.0.5, and 0≤δ.sub.H≤3 MPa.sup.0.5; and 0 to 85 volume percent parachlorobenzotrifluoride; wherein the amounts of the first solvent, the second solvent, and parachlorobenzotrifluoride sum to at least 85 volume percent. The first solvent can comprise methyl acetate, acetone, dimethyl carbonate, ethyl acetate, n-butylamine, propyl acetate, tetrahydrofuran, or a combination thereof. The second solvent can comprise cyclohexene, cyclohexane, cyclopentane, methylcyclohexane, or a combination thereof. The solvent compositions are particularly useful in an adhesive composition. An adhesive composition includes the solvent composition, a rubber, and a tackifying resin. A method of bonding two surfaces is also described.

In an embodiment a solvent composition can comprise, based on the total volume of the solvent composition, 10 to 95 volume percent of a first solvent, wherein the first solvent has Hansen solubility parameters of: 15 MPa.sup.0.5≤δ.sub.D≤17 MPa.sup.0.5, 4≤δ.sub.P≤10.5 MPa.sup.0.5, and 7≤δ.sub.H≤10 MPa.sup.0.5; 5 to 95 volume percent of a second solvent, wherein the second solvent has Hansen solubility parameters of: 16 MPa.sup.0.5≤δ.sub.D≤17.5 MPa.sup.0.5, 0≤δ.sub.P≤3 MPa.sup.0.5, and 0≤δ.sub.H≤3 MPa.sup.0.5; and 0 to 85 volume percent parachlorobenzotrifluoride; wherein the amounts of the first solvent, the second solvent, and parachlorobenzotrifluoride sum to at least 85 volume percent. The first solvent can comprise methyl acetate, acetone, dimethyl carbonate, ethyl acetate, n-butylamine, propyl acetate, tetrahydrofuran, or a combination thereof. The second solvent can comprise cyclohexene, cyclohexane, cyclopentane, methylcyclohexane, or a combination thereof. The solvent compositions are particularly useful in an adhesive composition. An adhesive composition includes the solvent composition, a rubber, and a tackifying resin. A method of bonding two surfaces is also described.