Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/04—Acids; Metal salts or ammonium salts thereof
  • C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/12—Polymerisation in non-solvents
  • C08F2/16—Aqueous medium
  • C08F2/18—Suspension polymerisation
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F222/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides, or nitriles thereof
  • C08F222/02—Acids; Metal salts or ammonium salts thereof, e.g. maleic acid or itaconic acid
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/003—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds

Definitions

• This invention relates to a method of making ionomeric particulate compositions that are useful for modifying the rheology, functionality, and physical properties of a polymer matrix so as to render the matrix more useful in applications that require adhesive properties.
• Polymerization occurs by mixing the premix phase with the water phase until the polymer beads are formed.
• the polymer beads may remain in the water prior to coating, during which time the beads are preferably storage-stable so as not to coalesce or agglomerate together. When coalescence is present, the beads tend to migrate towards one another and can form large masses. Coalescence of the beads hampers their handling and transportation and is undesirable.
• US Patent No. 5,952,420 discloses permeable, self-supporting, shaped structures that can be used in applications such as filters, masks, or respirators.
• the structure comprises a mass of active particulate (e.g., sorbents such as activated carbon, silica gel, or alumina granules) bonded together with pressure sensitive adhesive polymer particulates (also referred to as "PSA suspension beads " ) distributed in the mass of active particulate.
• active particulate e.g., sorbents such as activated carbon, silica gel, or alumina granules
• PSA suspension beads also referred to as "
• PSA suspension beads from about 10 to 100 micrometers can be prepared using a combination of surfactants and using, as another comonomer, a styrene sulfonate salt, such as sodium salt, to control particle size in the suspension polymerization.
• PSA suspension beads from about 1 to 10 micrometer can be achieved by homogenizing the polymerization reaction mixture comprising (1) the styrene sulfonate salt and (2) an amount of surfactant above the critical micelle concentration added to the water phase before suspension polymerization. See Column 9, lines 39-44 and lines 57-61.
• Senkus also discloses that the PSA polymer is essentially any polymer, copolymer, or blend of copolymer that has pressure sensitive adhesive properties.
• a related case is US Patent No. 5,696,199 (Senkus et al.)
• Chain transfer refers to the termination of a growing polymer chain and the start of a new one thus controlling the molecular weight of the polymer.
• the process can be affected by use of a chain transfer agent, which, in most cases, is some species that has been added to the polymerization process to effect chain transfer (referred to as an "added chain transfer agent").
• Chain transfer agents are used widely in polymerization processing to decrease the molecular weight of the polymer thereby imparting to the polymer one of the features necessary for pressure sensitive tack.
• chain transfer agents are typically added to the oil phase, which contains the monomers.
• common chain transfer agents include mercaptans. alcohols, and carbon tetrabromide, with isooctyl thioglycolate being a preferred one. See US Patent 4.833,179, Column 4, lines 37-42.
• the beads discussed thus far typically possess room temperature tackiness and thus are well suited as a pressure sensitive adhesive.
• This invention provides a novel method of making ionomeric particulate compositions where the method does not rely on the use of an added chain transfer agent to control the molecular weight of the resulting particulate. Because the inventive method does not use an added chain transfer agent, the resulting particles tend to have high molecular weight and also tend to have little to no pressure sensitive tack.
• the inventive method produces ionomeric particulates that can readily act as a reinforcing agent for and thereby strengthening a polymer matrix. Also, the invention does not rely on the practice of homogenization to control the particle size. Instead, the ionomeric particulates ' particle size can be controlled through the use of surfactants, one of which is a monomer surfactant.
• the method of making an ionomeric particulate of the invention comprises or consists essentially of: (a) forming an aqueous phase comprising an acid monomer, a metal oxide, and at least a first and a second surfactant, the first being a monomer surfactant; (b) forming an oil phase comprising at least one vinyl monomer; and (c) suspension polymerizing the oil phase.
• the present inventive method provides novel ionomeric particulates that can be dispersed into a polymer matrix to modify the rheology, functionality, and physical properties (e.g., cohesive strength, adhesion, toughness, elasticity, flexibility) of the polymer matrix so as to yield a useful organic particulate-filled adhesive.
• a key advantage of the present invention lies in the ability to tailor the ionomeric particulate so that when combined with a polymer matrix, the resulting organic particulate-filled adhesive exhibits the desired properties.
• the ionomeric particulates can be used to modify any polymer matrix that is compatible with it to yield an organic particulate-filled adhesive useful for a variety of diverse applications.
• the adhesive can be formulated to have pressure sensitive adhesive properties by choosing the appropriate ionomeric particulate composition, polymer matrix, and various other components, such as plasticizers and tackifiers.
• inventive ionomeric particulates are useful as part of a repulpable adhesive. Repulpability requires that the adhesive components be water-soluble or water-dispersible. When the components are water-dispersible, they are preferably of a sufficiently small particle size to pass through the repulping equipments.
• the inventive ionomeric particulates are also useful as a part of an adhesive that is applied to mammalian skin to remove undesirable materials (e.g., comedomes, unwanted hair follicles, dirt, oil, debris, dead skin).
• the present invention provides several processing advantages for controlling the ionomeric particulate properties, such as molecular weight and average diameter.
• Second, the inventive method eliminates a homogenization step as a means of controlling the particle size. Homogenization on a production size scale, i.e. for batch size on the order of a few hundred pounds or higher, can and usually do require specialized equipment and often careful monitoring of the process. Elimination of the homogenization step is a processing advantage that not only provides a user- friendly process but also reduces costs in labor and machinery.
• Another advantage of the present invention is the ability to make an ionomeric particulate that has little to no acid functional groups.
• the ionomeric particulate still has a surface that is rich in inorganic salt groups attached to a polymer chain. This type of tailoring can be achieved by using a sufficient amount of a metal oxide to nearly fully neutralize the acid monomer.
• Yet another advantage of the present invention involves the post addition of dimethylaminoethyl methacrylate (DMAEMA) during a second stage of suspension polymerization, as further described below.
• DMAEMA dimethylaminoethyl methacrylate
• Organic particulate-filled adhesive refers to an adhesive system having ionomeric particulate dispersed in a polymer matrix so as to modify the physical properties of the matrix.
• “Ionomeric particulate” means a polymer particle (typically in spherical form), having an oleophilic rich core and a surface that is rich in inorganic salt groups (such as zinc salt) attached to a polymer chain.
• “Monomer surfactant” acts as a surfactant in that it aids in the initial formation of the polymer bead during suspension polymerization but it is believed that at least a portion of the surfactant polymerizes and becomes a part of the ionomeric particulate. Also, at least a portion of the surfactant polymerizes in the water phase.
• Pressure sensitive adhesive means the adhesive has properties that include sufficient inherent tack, sufficient loss modulus, and sufficiently low glass transition temperature, to enable it to form a firm bond with a substrate upon contact under light pressure, e.g. finger pressure, at the temperature of use. e.g. room temperature of about 23° C (73° F).
• the ionomeric particulates are typically made by suspension polymerizing an oil phase in a water phase (often referred to as the "dispersion medium"). Bulk polymerization can be carried out in suspended droplets. Typically, it is desirable to keep the droplets from coalescing as they proceed from a liquid to a solid state by using various techniques, such as using suspending agents and surfactants.
• the oil phase which is insoluble in water, typically contains the vinyl monomer and an initiator.
• the water phase typically contains deionized water, acid monomer, metal oxide, surfactants, and optionally polyacrylamide. and suspending agents.
• the inventive method yields ionomeric particulate having an average diameter of about 1 to 200 micrometers, more preferably about 1 to 100 micrometers, and most preferably about 1 to 10 micrometers.
• the ionomeric particulates are stable in the aqueous solution. If desired, however, the particulates can be collected, dried, and stored as described in US Patent 4.952.650 (Young et al.).
• pressure sensitive tack describes the properties that enable an adhesive to form a bond with the surface of another material upon brief contact under light pressure, as defined by ASTM D 2979-71 (1980). Also, under ASTM D 907-82 (1985) "pressure sensitive tack " requires that the bond established be of measurable strength. Both ASTM references are hereby incorporated by reference.
• the vinyl monomers is preferably present in an amount of at least 80 parts. more preferably about 85 to 95 parts, based on 100 parts total monomer content.
• Vinyl monomers can be straight chain, branched, or cyclic.
• One class of vinyl monomers useful in the present invention include monofunctional unsaturated acrylate ester monomers, of which a preferred class includes acrylic acid ester of non-tertiary alcohol having 1 to 14 carbon atoms. Included within the preferred class of acrylate monomers are, e.g..
• isooctyl acrylate IOA
• isononyl acrylate 2-ethylhexyl acrylate
• decyl acrylate dodecyl acrylate
• n-butyl acrylate hexyl acrylate
• hydroxyethyl acrylate HEMA
• HEMA hydroxyethyl methacrylate
• Other preferred vinyl monomers include vinyl acetate, styrene. octylacrylamide. and N-vinyl lactams such as N-vinyl pyrrolidone and N-vinyl caprolactam. These latter vinyl monomers can be used in combination with the above described acrylate monomers.
• the initiator is preferably present in an amount of about 0.05 to 1 part based on
• Useful initiators for polymerizing the vinyl monomers include those suitable for free-radical polymerization of the vinyl monomers.
• the initiators are preferably oil-soluble and have low solubility in water.
• Illustrative examples of useful initiators include organic peroxides such as benzoyl peroxide, lauryl peroxide, and various thermal initiators such as 2,2 " - azobisisobutyronitrile.
• a preferred thermal initiator is 2.2 " -azobis(2- methylbutyronitrile), commercially available from E. I. Du Pont de Nemours and Company, Wilmington, DE, under the trade name VAZOTM 67.
• the acid monomer is preferably present in an amount up to about 20 parts based on the total monomer content.
• Acid monomers useful in for this invention preferably contain a carboxylic acid group.
• Acid monomers useful for the practice of this invention include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and citraconic acid.
• Preferred acid monomers include acrylic acid and methacrylic acid.
• the metal oxide is present in an amount necessary * to fully neutralize the acid functionality of the acid monomer.
• the metal oxide is zinc oxide and the acid monomer is methacrylic acid. To have "fully neutralize "" particulates require up to one (1) mole of zinc oxide per two (2) moles of methacrylic acid.
• a fully neutralized ionomeric particulate can be used to tailor the interaction between the particulates and the polymer matrix when making an organic particulate- filled adhesive.
• a fully neutralized ionomeric particulate is used as a component in an organic particulate-filled adhesive that desirably has little to no interaction with the substrate to which the adhesive is applied. This situation is particularly important if the substrate contains acid sensitive groups on its surface. If, on the other hand, the organic particulate-filled adhesive contains ionomeric particulate that has acid functional groups, there may be some interaction between the adhesive and the substrate containing acid sensitive groups. This interaction could result in leaving residual adhesive on the substrate, an undesirable result when clean removal of the adhesive is a desired feature.
• the ionomeric particulate can have acid functionality, which arises when the acid monomer is not fully neutralized.
• the metal oxide can be used to tailor the functionality of the ionomeric particulate.
• One skilled in the art should take care in selecting a suitable polymer matrix when making the organic particulate-filled adhesive given the different functionality of the ionomeric particulate. In other words, a polymer matrix suitable for a fully neutralized ionomeric particulate may not be suitable when the ionomeric particulate contains acid functionality.
• zinc oxide ZnO
• other useful metal oxides include calcium oxide (CaO), and magnesium oxide (MgO). It is believed that the metal oxides react with the acid monomer to form metal ionic salts of acid monomer.
• Surfactants are preferably present in an amount of about 3 to 10 parts based on the total monomer content.
• the first type can be referred to as a monomeric surfactant.
• the second type can be referred to as conventional surfactants, which include those selected from the group consisting of non-ionic surfactant, anionic surfactant, and mixtures thereof.
• Examples of the monomer surfactant include sodium styrene sulfonate.
• Monomer surfactants not only function like conventional surfactants in suspension polymerization by aiding in the formation of suspension beads and minimizing coalescence of the beads, but it is believed that at least a portion of the surfactant can polymerize and become a part of the ionomeric particulate. Because monomer surfactants can be polymerized, there may be little residue of these surfactants in the aqueous phase. In this respect, monomer surfactants differ from conventional surfactants.
• Useful conventional surfactants that are non-ionic have a HLB (Hydrophilic-
• HLB number describes the balance of the size and strength of the hydrophilic (water-loving or polar) groups and lipophilic (oil- loving or non-polar) groups of the surfactant.
• Illustrative useful non-ionic surfactants include (1) polyethers, e.g., ethylene oxide and propylene oxide condensates, which include straight and branched C 2 to C* 8 alkyl, alkylaryl, and alkenyl alcohol based copolymers of ethylene oxide and propylene oxide, such as those from Union Carbide Company.
• TERGITOL series (2) block copolymers of ethylene oxide and propylene oxide, such as those available from BASF Company, Mt. Olive, NJ, under the trademarked PLURONIC and TETRONIC.
• suitable non-ionic surfactants are the TWEEN and SPANS, trademarked compositions from ICI Inc., which are polyoxyalkylene derivatives of sorbitan and fatty acid esters.
• Useful conventional surfactants that are anionic include sulfates or sulfonates, such as sodium alkylaryl sulfonates and poly(alkyleneoxy) sulfates or sulfonates.
• a preferred sodium alkylaryl sulfonate is sodium dodecylbenzene sulfonate, which is commercially available from Rhone-Poulenc as RodacalTM DS-10.
• the poly(alkyleneoxy) compounds are ethylene oxide and propylene oxide or ethylene oxide and butylene oxide condensates, which include straight and branched C to C* 8 alkyl, alkylaryl, and alkenyl alcohol based copolymers of ethylene oxide and propylene oxide or ethylene oxide and butylene oxide.
• This anionic surfactant is available from BASF under the trademark MAZON SAMTM 211, which is an alkylene polyalkoxy sulfate.
• Suspending agents are preferably present in an amount of about 0.005 to 5 parts based on the total monomer content. In general, these agents are used in suspension polymerization to minimize coalescence of the particles. They can be minimally water- soluble inorganic salts, such as tribasic calcium phosphate, calcium carbonate, calcium sulfate. barium sulfate, barium phosphate, hydrophilic silicas, and magnesium carbonate.
• a preferred inorganic suspending agent is colloidal silica, such as Nalco 1042, available from Nalco Chemical Company.
• the inventive ionomeric particulate contains dimethylaminoethy methacrylate (DMAEMA).
• DMAEMA dimethylaminoethy methacrylate
• amino groups are basic in nature, ionomeric particulates containing them could be useful for certain substrates. The advantages discussed earlier for having a fully neutralized ionomeric particulate would apply here.
• the DMAEMA is preferably present in an amount of about 0.01 to 30 parts based on the total monomer content.
• the method of making an ionomeric particulates containing DMAEMA requires a two-step suspension polymerization process. In the first step, the oil phase and water phase are allowed to polymerize to form stable particles. Preferably, the suspended oil droplets are about 60% polymerized before starting the second step, which involves the addition of DMAEMA.
• the suspension polymerization reaction was carried out in a 2-liter split-flask equipped with a condenser, thermometer, nitrogen inlet, motor-driven agitator, and a heating mantle with temperature control.
• the reaction flask was first charged with the ingredients of the water phase listed in the respective Tables and heated to 58°C. The water phase was maintained at this temperature with agitation and nitrogen-purging for about 1 hour to remove oxygen from the flask. Afterwards, a premixed charge of the oil phase, listed in the respective Tables, was added to the flask while vigorous agitation (700 rpm) was maintained to obtain a good suspension. The ensuing suspension polymerization reaction was continued with nitrogen purging.
• the reaction was continued at 75 °C for about another 2 hours, and then the reaction mixture was cooled to room temperature. The approximate volume average particle size of the resulting ionomeric particulate is given. The resulting ionomeric particulate was stored in the water phase.
• Examples 1 to 3 show the various acrylate ester monomer of a non-tertiary alcohol having 1 to 14 carbon atoms that can be used to make ionomeric particulate composition.
• the volume average diameter of the resulting particulate were less than about 10 micrometers ( ⁇ m).
• NalcoTM 1042 colloidal silica from Nalco Chemical Company, Naperville, IL Rodacal DS-10 surfactant, from Rhone-Poulenc. Cranbury, NJ c VazoTM 67 initiator, from du Pont de Nemours and Company. Wilmington, DE
• Examples 4 to 10 Examples 4 to 10, the components of which are listed in Table 2 below, showed ionomeric particulates made at various zinc oxide concentrations. Also, MgO. a metal oxide, was used (Example 10). In most cases, the volume average diameter of the resulting particulate were less than about 10 micrometers ( ⁇ m). TABLE 2
• VazoTM 67 initiator from du Pont de Nemours and Company. Wilmington, DE
• Example 11 to 15 showed ionomeric particulates made with various vinyl and acrylate monomers.
• Example 16 showed a fully neutralized ionomeric particulate composition, i.e., the amount of zinc oxide used was in a sufficient amount so as to nearly fully neutralize the acid monomer.
• NalcoTM 1042 colloidal silica from Nalco Chemical Company, Naperville, IL RodacalTM DS-10 from Rhone-Poulenc, Cranbury, NJ c Mazon SAMTM 211, from BASF, Mt. Olive, NJ d VVaazzooTMTM 6677 iinniittiiaattoorr, 1 from du Pont de Nemours and Company, Wilmington, DE bimodal distribution
• Example 16 This example showed a two-step suspension polymerization method of making ionomeric particulates having DMAEMA.
• the first step was carried out as follows. A 2-liter split-flask was equipped with a condenser, thermometer, nitrogen inlet, motor- driven agitator, and a heating mantle with temperature control.
• the reaction flask was charged with the ingredients of the water phase containing: about 610 grams of deionized water, about 4.7 grams of methacrylic acid, about 2.5 grams of zinc oxide, about 2.5 grams of NalcoTM 1042 collodial silica, about 25 grams of sodium styrene sulfonate, and about 3.23 grams of sodium dodecylbenzene sulfonate (RodocalTM DS- 10).
• the water phase was heated to about 59°C.
• the water phase was maintained at this temperature with agitation and nitrogen-purging for about 1 hour to remove oxygen from the flask.
• the second step of the suspension polymerization was carried out as follows. After one hour at about 59°C and one hour at about 70°C, about 10 grams of a mixture of 50:50 weight ratio of DMAEMA and deionized water was added to the flask during 40 minutes. Mixing was continued. After an additional hour at 70°C, the reaction was considered complete and the resulting ionomeric particulates contained DMAEMA.

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• 1999
  • 1999-11-17 US US09/441,578 patent/US6620874B1/en not_active Expired - Lifetime
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