Abstract:
Methods of (co)polymerizing ethylenically-unsaturated materials, including the steps of providing a non-deaerated mixture of free radically (co)polymerizable ethylenically-unsaturated material in a batch reactor, exposing the non-deaerated mixture to a source of ionizing radiation for a time sufficient to initiate (co)polymerization of at least a portion of the free radically (co)polymerizable ethylenically-unsaturated material, and allowing the free radically (co)polymerizable ethylenically-unsaturated material to (co)polymerize under essentially adiabatic conditions while continuing to expose the mixture to the source of ionizing radiation for a time sufficient to yield an at least partially (co)polymerized (co)polymer. The ethylenically-unsaturated materials are selected from vinyl-functional monomers, vinyl-functional oligomers, vinyl-functional macromers, and combinations thereof. The mixture is preferably free of thermally-induced or UV-induced free radical polymerization initiators. The source of ionizing radiation may be a gamma ray source, an x ray source, an electron beam source with an emission energy greater than 300 keV, and combinations thereof.
Abstract:
An adhesive composition includes a first acrylic polymer preparable from first components and a second acrylic polymer. The first components comprising i) a branched first alkyl (meth)acrylate having from 4 to 22 carbon atoms, and ii) at least one of acrylic acid and methacrylic acid. The second acrylic polymer is preparable from second components comprising iii) at least one second alkyl (meth)acrylate having from 4 to 22 carbon atoms, iv) a (meth)acrylamide represented by the formula wherein R1 is H or methyl, and R2 and R3 each independently represents H or an alkyl group having from 1 to 8 carbon atoms, or taken together R2 and R3 may form a divalent alkylene group having from 4 to 6 carbon atoms, and v) at least one high Tg macromer having a terminal free-radically polymerizable unsaturated group, the high Tg macromer having a Tg of at least 45° C. Based on the combined total weight of the at least one first acrylic polymer and the at least one second acrylic polymer, the at least one second acrylic polymer is present at a level of from 5 to 40 percent by weight. Methods of making the adhesive composition are also disclosed.
Abstract:
Flame retardant adhesive are described. The flame retardant adhesives include at least 93 wt. % an acrylic copolymer. This acrylic copolymer comprises the polymerization reaction product of 50 to 92 wt. % of at least one alkyl (meth)acrylate monomer, 3 to 25 wt. % of at least one nitrogen-containing monomer, and 5 to 25 wt. % of at least one vinyl-functional poly(methacrylate) macromer. Articles incorporating such adhesive are also described.
Abstract:
Disclosed herein is an optical device having a light source, a viscoelastic lightguide and a retroreflective film suitable for retroreflecting light. Light from the light source enters the viscoelastic lightguide and is transported within the lightguide by total internal reflection. The optical device may have a “front lit” configuration such that light being transported within the lightguide is extracted and retroreflected by the film toward a viewer. The optical device may have a “back lit” configuration such that light being transported within the lightguide is extracted and transmitted through the film toward a viewer. The retroreflective film may comprise beaded retroreflective sheeting such as that used in traffic signs and markings.
Abstract:
Described herein is a composition comprising a polymeric blend of: (i) a first polymer comprising at least one acrylic block copolymer, wherein the at least one acrylic block copolymer comprises: (a) at least two A block polymeric units wherein each A block has a glass transition temperature of at least 90 C and each A block is independently derived from a monoethylenically unsaturated monomer comprising a first (meth)acrylate monomer; and (b) at least one B block polymeric unit wherein the at least one B block has a glass transition temperature no greater than −30 C and wherein the at least one B block is derived from a monoethylenically unsaturated monomer comprising a second (meth)acrylate monomer; and (ii) a second polymer selected from at least one of a polyvinyl acetal resin, a polyvinyl acetate, and a cellulose ester.
Abstract:
Disclosed herein is an optical device having a light source, a viscoelastic lightguide and a retroreflective film suitable for retroreflecting light. Light from the light source enters the viscoelastic lightguide and is transported within the lightguide by total internal reflection. The transported light is extracted from the lightguide and retroreflected at a structured surface of the retroreflective film. The optical device may have a “front lit” or a “back lit” configuration depending on the relative positioning of the lightguide and the retroreflective film. The retroreflective film may include prismatic retroreflective sheeting, holographic film or film structured with diffraction gratings. The optical device may be used, for example, as a sign or marking, a license plate assembly, a tail light assembly for vehicles, a security laminate for protection of documents against tampering, or an illumination device.
Abstract:
Methods of forming an adhesive composition including the steps of (a) combining a non-deaerated mixture comprising at least one free radically (co)polymerizable ethylenically-unsaturated material with a sealable packaging, wherein the packaging contains the non-deaerated mixture; (b) sealing the non-deaerated mixture in the packaging to form a sealed packaging; and (c) exposing the non-deaerated mixture in the sealed packaging to a source of ionizing radiation for a time sufficient to initiate (co)polymerization of at least a portion of the at least one free radically (co)polymerizable ethylenically-unsaturated material to form an adhesive composition in the sealed packaging. The (co)polymerization takes place essentially non-adiabatically. At least a portion of the packaging is meltable and mixable with the adhesive composition so as to provide a flowable coatable adhesive composition when the sealed packaging containing the adhesive composition is heated to a temperature sufficient to melt at least a portion of the packaging.
Abstract:
An adhesive tape that is stretch releasable, articles that contain the adhesive tape, and uses of the adhesive tape are disclosed. The adhesive tapes include a backing layer that is adjacent to at least one pressure-sensitive adhesive layer. The backing layer typically is optically clear and includes a poly(alkylene) copolymer. The pressure-sensitive adhesive layer is a silicone-based adhesive composition. In many embodiments, the adhesive tape is optically clear.
Abstract:
This disclosure relates to viscoelastic damping materials and constructions which may demonstrate low temperature performance and adhesion and which may be used in making vibration damping composites. Viscoelastic damping materials and constructions may include polymers or copolymers of monomers according to formula I: CH2═CHR1—COOR2 [I] wherein R1 is H, CH3 or CH2CH3 and R2 is a branched alkyl group containing 12 to 32 carbon atoms.
Abstract:
Disclosed herein is an optical device having a light source and a viscoelastic lightguide. Light from the light source enters the viscoelastic lightguide and is transported within the lightguide by total internal reflection. The viscoelastic lightguide may comprise a pressure sensitive adhesive. The optical device may be used in a variety of constructions wherein the device emits light being transported within the viscoelastic lightguide. Constructions include those used for signs, markings, illumination devices, display devices, keypad assemblies and tail light assemblies for vehicles.