Abstract: The invention relates to a pressure sensitive adhesive (PSA) composition for clear-on-clear labels. The PSA composition contains an aqueous polymer emulsion comprising an acrylic-based copolymer derived from components including (i) monomers comprising acrylate monomer(s) and vinyl aromatic compound(s), (ii) a reactive surfactant and (iii) a chain transfer agent. The pressure sensitive adhesive composition is resistant to water whitening and is in compliance with demands on food contact materials. Further, the invention relates to use of said PSA composition as well as to an adhesive label (1) comprising the PSA composition, a labelled item (101) comprising said adhesive label and a label laminate web (8) for providing the adhesive labels.

Abstract: Water-dispersible adducted rosin esters, a process for making them, and their use in aqueous tackifier dispersions for pressure-sensitive adhesives are disclosed. Reaction of a rosin with a polyol gives a rosin ester intermediate, which is then reacted with a dienophile to produce an adducted rosin ester. The adducted rosin ester is further esterified with a polyethylene glycol having an Mw<700 to produce the water-dispersible adducted rosin ester. Esterification with the low-molecular-weight PEG imparts good water dispersibility to the adducted rosin ester while maintaining compatibility with other tackifier components. Combination of the aqueous tackifier dispersions with polymer emulsions, particularly acrylics, gives pressure-sensitive adhesives that deliver good loop tack and peel properties compared with commercial alternatives, even when the coat weight is reduced by 20%.

Abstract: Water-dispersible adducted rosin esters, a process for making them, and their use in aqueous tackifier dispersions for pressure-sensitive adhesives are disclosed. Reaction of a rosin with a polyol gives a rosin ester intermediate, which is then reacted with a dienophile to produce an adducted rosin ester. The adducted rosin ester is further esterified with a polyethylene glycol having an Mw<700 to produce the water-dispersible adducted rosin ester. Esterification with the low-molecular-weight PEG imparts good water dispersibility to the adducted rosin ester while maintaining compatibility with other tackifier components. Combination of the aqueous tackifier dispersions with polymer emulsions, particularly acrylics, gives pressure-sensitive adhesives that deliver good loop tack and peel properties compared with commercial alternatives, even when the coat weight is reduced by 20%.

Abstract: Process for preparing a pressure sensitive adhesive having enhanced resistance to water-whitening comprising the steps of: (a) forming a mixture in water of (i) a polymerization initiator which produces radicals by a thermal decomposition and (ii) a water-dispersible polymerizable surfactant with a terminal allyl amine moiety; polyoxyalkylene-1-(allyloxymethyl)alkyl ether sulfate salt(s) and/or mixtures thereof, (b) forming a polymerizable aqueous pre-emulsion comprising (i) a hydrophobic monomer mixture comprising at least one alkyl (meth)acrylate ester of a C1-4 alcohol and at least one styrenic monomer, (ii) one or more hydrophilic monomer(s), and (iii) of at least one partially hydrophilic monomer(s) selected from N-vinyl pyrrolidone; alkyl (meth)acrylate esters of methanol or ethanol; and/or mixtures thereof, the pre-emulsion further comprising surfactant, (c) contacting the pre-emulsion with the water mixture; and (d) continuously adding said pre-emulsion to said mixture to polymerize said pre-emulsion

Abstract: There is described a process for preparing a pressure sensitive adhesive having enhanced resistance to water-whitening comprising the steps of: (a) forming a mixture in water of (i) an effective initial amount of a polymerization initiator which produces radicals by a thermal decomposition to form a mixture and optional further surfactant; (ii) an effective amount of a water-dispersible polymerizable surfactant with a terminal allyl amine moiety; polyoxyalkylene-1-(allyloxymethyl) alkyl ether sulfate salt(s) and/or mixtures thereof, (b) forming a polymerizable aqueous pre-emulsion comprising (i) a hydrophobic monomer mixture comprising at least one alkyl (metha)acrylate ester of an C1-4alcohol and up to about 30% by weight of the mixture of at least one styrenic monomer, (ii) at least about 1% of the total weight of (i) to (iii) of one or more hydrophilic monomer(s), (iii) at least about 5% of the total weight of (i) to (iii) of at least one partially hydrophilic monomer(s) selected from N-vinyl pyrrolidone;

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) at least one hydrophobic alkyl acrylate or alkyl methacrylate ester of an alcohol, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt. % of at least one partially hydrophilic alkyl acrylate or alkyl methacrylate ester of an alcohol, and (iv) a water-soluble or water-dispersible polymerizable surfactant selected from compounds having a terminal allyl amine moiety, substituted phenyl compounds having at least one alkenyl substituent, polyoxyalkylene-1-(allyloxymethyl)alkyl ether sulfate salts, or mixtures thereof, and the average particle size of the polymer is less than or equal to 200 nm. Also disclosed are processes for preparing same.

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) at least one hydrophobic alkyl acrylate or alkyl methacrylate ester of an alcohol, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt. % of at least one partially hydrophilic alkyl acrylate or alkyl methacrylate ester of an alcohol, and (iv) a water-soluble or water-dispersible polymerizable surfactant selected from compounds having a terminal allyl amine moiety, substituted phenyl compounds having at least one alkenyl substituent, polyoxyalkylene-1-(allyloxymethyl) alkyl ether sulfate salts, or mixtures thereof, and the average particle size of the polymer is less than or equal to 200 nm. Also disclosed are processes for preparing same.

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) a hydrophobic monomer mixture of at least one alkyl acrylate or alkyl methacrylate ester of an alcohol wherein the alkyl portion of the alcohol is linear or branched and contains at least 4 carbon atoms, and at least one styrenic monomer, wherein the styrenic monomer is up to about 30 wt. % of the total hydrophobic monomer mixture, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt.

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) a hydrophobic monomer mixture of at least one alkyl acrylate or alkyl methacrylate ester of an alcohol wherein the alkyl portion of the alcohol is linear or branched and contains at least 4 carbon atoms, and at least one styrenic monomer, wherein the styrenic monomer is up to about 30 wt. % of the total hydrophobic monomer mixture, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt.

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) at least one hydrophobic alkyl acrylate or alkyl methacrylate ester of an alcohol, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt. % of at least one partially hydrophilic alkyl acrylate or alkyl methacrylate ester of an alcohol, and (iv) a water-soluble or water-dispersible polymerizable surfactant selected from compounds having a terminal allyl amine moiety, substituted phenyl compounds having at least one alkenyl substituent, polyoxyalkylene-1-(allyloxymethyl) alkyl ether sulfate salts, or mixtures thereof, and the average particle size of the polymer is less than or equal to 200 nm. Also disclosed are processes for preparing same.

Abstract: Pressure sensitive adhesive compositions having enhanced resistance to water-whitening comprising an aqueous emulsion polymer are disclosed. The polymer comprises the polymerization reaction product of a polymerizable aqueous emulsion comprising: (i) a hydrophobic monomer mixture of at least one alkyl acrylate or alkyl methacrylate ester of an alcohol wherein the alkyl portion of the alcohol is linear or branched and contains at least 4 carbon atoms, and at least one styrenic monomer, wherein the styrenic monomer is up to about 30 wt. % of the total hydrophobic monomer mixture, (ii) at least about 1 wt. % of at least one hydrophilic monomer, (iii) at least about 5 wt.

Abstract: The dispersion polymerization of isobutylene includes a dispersing agent. The dispersing agent is a compound having a CO.sub.2 -phobic moiety and at least one CO.sub.2 -philic moiety. The CO.sub.2 -phobic moiety is polysibutylene-philic. Novel polymerization initiators are organometallic.

Abstract: A process is disclosed for carbocationically polymerizing monomers having one or more carbon-carbon double bonds in a medium primarily of carbon dioxide at or above 31.1.degree. C. and at or above 73 bars pressure. The supercritical carbon dioxide can replace traditional solvents for carbocationic polymerizations. While traditional solvents like methylene chloride do not function to allow polymers to form above cryogenic temperatures, it has been found that polymers can be formed at higher temperatures in this supercritical medium.

Abstract: The synthesis of poly(isobutylene-b-methyl vinyl ether) (PIB-b-PMeVE) by living carbocationic polymerization (LC.sym.Pzn) employing the sequential monomer addition (SMA) technique is described. The process starts by producing the living PIB.sym. block employing the 2-chloro-2,4,4-trimethylpentane (TMPC11/TiCl.sub.4 initiating system in the presence of the common ion salt tetra-n-butylammonium chloride (n-Bu.sub.4 NCl) in CH.sub.3 Cl/n-C.sub.6 H.sub.14 or CH.sub.2 Cl.sub.2 /n-C.sub.6 H.sub.14 mixed solvents at -80.degree. C. and continues by the addition of methyl vinyl ether (MeVE). The second living block forms only in the presence of excess TiCl.sub.4 suggesting that the species that starts the second block and subsequently sustains its growth is a MeVE.multidot.TiCl.sub.4 complex. The stoichiometry of this complex (1:1 or 1:2) is uncertain. The TiCl.sub.4 remains attached to the MeVE units after their incorporation into the diblock, however, it can be readily removed by water.

Abstract: The invention relates to a process for preparing polymers, with a polydispersity optionally approaching the theoretical polydispersity and substituted by functional groups in .alpha.,.omega.-positions, via radical polymerization of radically polymerizable monomers and using one or more initiators. In compliance with this process the degree of polymerization is maintained at the desired value by continuous elevation of the temperature.In case of a given heat program, the process of the invention renders possible to increase the conversion in producing polymers without the deterioration of the polydispersity.