Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
• • 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
  • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
  • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
  • C08F290/04—Polymers provided for in subclasses C08C or C08F
  • C08F290/048—Polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
  • C09J4/06—Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00

Definitions

• the present invention relates to improved odor of polyme ⁇ zable or curable acrylic adhesives.
• Acrylic structural adhesives are well known articles of commerce which are extensively used commercially for bonding metal and plastic mate ⁇ als. Acrylic structural adhesives have found growing use in the automotive industry where the adhesive bonding of metal parts is replacing welding and mechanical fastening techniques. However, these applications give ⁇ se to unique requirements not easily met by previously available adhesives. These requirements include high bond strength, improved failure mode and low odor.
• Acrylic adhesives typically comprise a mixture of one or more olefmic reactive monomers such as methyl methacrylate or methacryhc acid and cu ⁇ ng agents, with cure or polymerization being effected through a free radical polymerization mechanism
• the adhesives preferably contain one or more polyme ⁇ c mate ⁇ als which may or may not be reactive, that is, capable of being polymerized per se or at least capable of interpolyme ⁇ zing with the reactive monomers, such as grafting onto or crosslmking the growing polymers from the reactive monomer polymerization.
• the adhesives can contain other additives for improving adhesion to substrate mate ⁇ als, environmental resistance, impact strength, flexibility, heat resistance, and the like.
• P.C.T. Publication WO 97/39074 discloses the use of at least one polyme ⁇ c mate ⁇ al which can act as a toughening agent in an acrylic adhesive such as polychloroprene, polymer- ln-monomer syrup, chlorosulphonated polyethylene rubber, copolymers of butadiene and at least one monomer copolyme ⁇ zable therewith, for example, styrene, acrylonit ⁇ le, methacrylonitrile (e.g.
• functional monomer such as acrylic acid, methacryhc acid, maleic anhydride, fumaric acid, styrene, and methyl methacrylate to give, for example, methacrylate-terminated polybutadiene homopolymers and/or copolymers.
• the '419 patent further describes acrylic adhesives with olefinic monomer, olefinic urethane reaction product of an isocyanate- functional prepolymer and a hydroxy-functional monomer, phosphorus-containing compounds, an oxidizing agent and a free radical source.
• These tougheners represented by the formulae for polymer A or polymer B in claim 1 are referred to herein as "olefinic-terminated liquid elastomer produced from a hydroxyl-terminated polyalkadiene” or, alternatively, as “isocyanate-capped methacrylate-terminated polyalkadiene produced from a hydroxyl-terminated polyalkadiene”.
• the composition also includes a free radical- polymerizable monomer such as an olefinic monomer and, optionally, a second polymeric mate ⁇ al.
• the composition is an adhesive that also includes a phosphorus-containing compound and an ambient temperature-active redox catalyst.
• the '834 patent desc ⁇ bes polymers A and B with a number average molecular weight of about 1,500 to 10,000, preferably about 1,500 to 6,000.
• an adhesive that has a lower or less objectionable odor.
• an adhesive that includes a free radical-polymenzable monomer component that includes at least a reaction product of a (hydroxy)acrylate with an anhyd ⁇ de but is substantially free of methyl methacrylate or methacryhc acid.
• the free radical-polymenzable monomer component typically is a mixture of free radical-polymenzable that at least includes a monomer that is a reaction product of a (hydroxy)acrylate with an anhydnde.
• This reaction product allows for the removal from the adhesive formulation of at least one of methyl methacrylate, methacryhc acid or other offensive odo ⁇ ferous monomers.
• the adhesive compositions are substantially free of at least methyl methacrylate or methacryhc acid because the use of these ingredients in amounts as little as 2 or 3 weight percent results in offensive odor emissions in certain applications.
• substantially free of methyl methacrylate or methacryhc acid is used herein, it is intended to mean trace amounts or amounts less than an offensive odor generating amount which can be as little as 2 or 3 weight percent of the total formulation.
• the odor of methacryhc acid can be particularly offensive.
• the monomer component can include methylmethacrylate but is substantially free of methacryhc acid
• the (hydroxy) acrylate compound utilized to prepare the reaction product included in the monomer component of the invention can be any acrylate compound charactenzed by the presence of a hydroxy group
• suitable hydroxy-functional acrylate compounds include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2- hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 3- hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 3-hydroxypentyl acrylate, 6-hydroxynonyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxypentyl methacrylate, 5-hydroxypentyl methacrylate, 7-hydroxyheptyl methacrylate, 5-hydroxydecyl methacrylate, N-hydroxymethyl acrylamide, N-hydroxymethyl methacrylamide, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycenn dime
• lactone-acrylate adducts lactone-modified acrylate or methacrylate acid esters
• lactone-acrylate adducts lactone-modified acrylate or methacrylate acid esters
• Lactones employed in the preparation of the lactone- acrylate adducts may be the same as the lactones defined above with respect to the preparation of the lactone-based polyester polyols
• An example of a lactone-acrylate adduct is a 2-hydroxyethyl acrylate-caprolactone adduct such as TONE M-100 supplied by Union Carbide Corporation
• the anhyd ⁇ de that is reacted with the (hydroxy)acrylate compound can be maleic anhyd ⁇ de, succinic anhyd ⁇ de, phathahc anhydnde, alkylsuccmic anhydnde, alkenylsuccinic anhydnde and the like
• the preferred reaction product is monomethacryloyloxyethyl phthalate commercially available from International Specialty Chemicals under the trade designation BISOMER EMP
• Representative olefinic monomers include esters of (meth)acryl ⁇ c acid such as ethyl methacrylate, butyl methacrylate, butyl acrylate, cyclohexyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, ethyl acrylate, diethylene glycol dimethacrylate, dicyclopentadienyloxyethyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, glycidyl methacrylate and tetrahydrofurfuryl methacrylate; acrylic acid; substituted (meth)acryhc acids such as itaconic acid, acrylonit ⁇ le, methacrylonitnle, acrylamide and methacrylamide; styrene; substituted styrenes such as vinyl styrene, chlorostyrene, methyl st
• a mixture of the (hydroxy)acrylate/anhydnde reaction product with at least one other of the above-descnbed free radical-polymenzable monomers is preferred.
• a combination of tetrahydrofurfuryl methacrylate (THFMA) and monomethacryloyloxyethyl phthalate is most preferred.
• the free radical-polymenzable monomer component is present in an amount of 10-90 % by weight of the pnncipal components.
• the "pnncipal components" are the free radical-polymenzable monomer component, an adhesion promoter, and at least one toughener or toughening agent.
• Any amount of the (hydroxy)acrylate/anhydnde reaction product can be present, but about 0.5 to 20 weight percent, more preferably 1.5 to 10 weight percent, is preferred, based on the total weight of the adhesive part that includes the free radical-polymenzable monomer component.
• the adhesive composition also can include 0-20% by weight of the pnncipal components of an adhesion promoter.
• An adhesion promoter is any adhesion promoter known to those of ordinary skill in the art as useful in promoting adhesion in acrylic adhesives.
• Preferred adhesion promoters are phosphorus-containing compounds that enhance metal adhesion and may be any derivative of phosphinic acid, phosphonic acid or phosphoric acid having at least one P — OH group and at least one organic moiety characterized by the presence of an olefinic group, which is preferably terminally located. A listing of such phosphorus compounds is found in U.S. Pat. No. 4,223,115.
• a preferred phosphorus- containing compound has a structure that may be represented by the formula:
• R 20 is selected from the group consisting of hydrogen, an alkyl group having from one to 8, preferably one to 4, carbon atoms, and CH 2 CH-;
• R 21 is selected from the group consisting of hydrogen, an alkyl group having from one to 8, preferably one to 4 carbon atoms;
• A is selected from the group consisting of — R 22 O — and R 23 O) n , wherein R 22 is an aliphatic or cycloaliphatic alkylene group containing from one to 9, preferably 2 to 6, carbon atoms;
• R 23 is an alkylene group having from one to 7, preferably 2 to 4, carbon atoms;
• n is an integer from 2 to 10, and m is one or 2, preferably one.
• Phosphorus-containing compounds having vinyl unsaturation are prefe ⁇ ed over such compounds having allylic unsaturation, with monoesters of phosphinic, phosphonic and phosphoric acids having one unit of vinyl or allylic, especially vinyl, unsaturation presently being preferred.
• Representative phosphorus-containing compounds include, without limitation, phosphoric acid; 2-methacryloyloxyethyl phosphate; bis-(2-
• SUBST ⁇ JTE SHEET RULE 26 methacryloxyloxyethyl) phosphate; 2-acryloyloxyethyl phosphate; bis-(2-acryloyloxyethyl) phosphate; methyl-(2-methacryloyloxyethyl) phosphate; ethyl methacryloyloxyethyl phosphate; methyl acryloyloxyethyl phosphate; ethyl acryloyloxyethyl phosphate; compounds of the above formula wherein R 8 is hydrogen or methyl and R 9 is propyl, isobutyl, ethylhexyl, halopropyl, haloisobutyl or haloethylhexyl; vinyl phosphonic acid; cyclohexene-3-phosphonic acid; alphahydroxybutene-2 phosphonic acid; 1 -hydroxy- l-phenylmethane-l,l-diphosphonic acid
• the adhesive composition also can include about 10-80% by weight of a toughener or toughening agent, based on the principal components.
• the toughening agent typically is a polymeric material that provides improved impact and shatter resistance to the resultant adhesive and decreases brittleness.
• the polymeric material may or may not include an olefinically unsaturated structure that is capable of being polymerized per se or copolymerized with at least one of the free radical polymerizable monomers described above.
• the polymeric material can be for example, various solid and liquid elastomeric polymeric materials, and in particular liquid olefinic-terminated elastomers as described in U.S. Patent Nos.
• Representative liquid olefinic-terminated elastomers disclosed in P.C.T. Publication WO 97/39074 include homopolymers of butadiene, copolymers of butadiene and at least one monomer copolymerizable therewith, for example, styrene, acrylonitrile, methacrylonitrile (e.g.
• functional monomer such as acrylic acid, methacryhc acid, maleic anhydride, fumaric acid, styrene, and methyl methacrylate to give, for example, methacrylate-terminated polybutadiene homopolymers and/or copolymers.
• the present invention may also include an ambient temperature reactive catalyst system.
• the ambient temperature-reactive catalyst systems that may be employed in the preferred adhesive systems are well-known redox couple systems and need not be discussed herein in detail. Basically, such systems comprise at least one oxidizing agent and at least one reducing agent which are co-reactive at room temperature to generate free radicals effective to initiate addition polymerization reactions and cure the adhesive. Substantially any of the known oxidizing and reducing agents which are so co-reactive can be employed.
• oxidizing agents include, without limitation, organic peroxides, such as benzoyl peroxide and other diacyl peroxides, hydroperoxides such as cumene hydroperoxide, peresters such as ⁇ -butylperoxybenzoate; ketone hydroperoxides such as methyl ethyl ketone hydroperoxide, organic salts of transition metals such as cobalt naphthenate, and compounds containing a labile chlorine such as sulfonyl chloride.
• organic peroxides such as benzoyl peroxide and other diacyl peroxides
• hydroperoxides such as cumene hydroperoxide, peresters such as ⁇ -butylperoxybenzoate
• ketone hydroperoxides such as methyl ethyl ketone hydroperoxide
• organic salts of transition metals such as cobalt naphthenate
• compounds containing a labile chlorine such as sulfonyl
• Representative reducing agents include, without limitation, sulfinic acids; azo compounds such as azoisobutyric acid dinitrile; alpha-aminosulfones such as bis(tolysulfonmethyl)-benzyl amine; tertiary amines such as diisopropanol-p-toluidine (DIIPT), dimethyl aniline, p-halogenated aniline derivatives and dimethyl-p-toluidine; and aminealdehyde condensation products, for example, the condensation products of aliphatic aldehydes such as butyraldehyde with primary amines such as aniline or butylamine.
• aminealdehyde condensation products for example, the condensation products of aliphatic aldehydes such as butyraldehyde with primary amines such as aniline or butylamine.
• the oxidizing agent will be present in an amount in the range from about 0.5 to about 50 percent by weight of bonding accelerator, with the amount of reducing agent being in the range from about 0.05 to about 10 preferably about 0.1 to about 6, percent by weight of polymerizable adhesive composition.
• DIIPT is the most preferred reducing agent.
• the most preferred oxidizing agent is benzoyl peroxide.
• the adhesive of the present invention may take many forms, the most preferred adhesive systems are provided as multipack or two-part adhesive systems where one package or part contains the free radical-polymerizable monomer component and the reducing agent and a second part or package contains the oxidizing agent.
• the two parts are mixed together at the time of use in order to initiate the reactive cure. After mixing the individual parts, one or both surfaces to be joined are coated with the mixed adhesive system and the surfaces are placed in contact with each other.
• the second package or part can include a bonding activator that includes the oxidizing agent for the redox catalyst system.
• the bonding activator can include:
• the carrier vehicles which are suitable for use in the bonding activators can be a simple inert solvent or diluent such as methylene chloride, or butyl benzyl phthalate, including mixtures of such solvents or diluents.
• the carrier vehicle should contain no more than 5% by weight of any moiety which is reactive with the oxidizing agent at room temperature.
• the carrier vehicle can be a more complex mixture including at least one film- forming binder in addition to inert solvent or diluent.
• the carrier vehicle can contain, in addition to solvent or solvent and film-forming binder, additives such as external plasticizers, flexibilizers, suspenders and stabilizers, providing that any such additives do not unacceptably adversely affect the stability of the activator composition.
• An exemplary two part system includes:
• the adhesive systems of the invention may be used to bond metal surfaces, such as steel, aluminum and copper, to a vanety of substrates, including metal, plastics, and other polymers, reinforced plastics, fibers, glass, ceramics, wood and the like. It is a feature of the present invention that the herein-desc ⁇ bed adhesive compositions can be employed to bond metal substrates such as steel, aluminum and copper with little, if any, pretreatment of the metal surface pnor to application of the adhesive.
• the adhesive systems of this invention provide effective bonding at room temperature, thus heat is not required either for applying the adhesive systems to the substrates or for curing.
• the adhesives of the present invention are preferred for bonding metal surfaces
• the present adhesive compositions may be applied as an adhesive, primer or coating to any surface or substrate capable of receiving the adhesive.
• the metals which are preferred for bonding with the present adhesives include zinc, copper, cadmium, iron, tin, aluminum, silver, chromium, alloys of such metals, and metallic coatings or platings of such metals such as galvanized steel including hot dipped, electrogalvanized steel and galvanealed steel.
• the adhesive coatings may be brushed, rolled, sprayed, dotted, knifed or otherwise applied to one substrate, but preferably to both substrates to desired thickness preferably not to exceed 60 mils.
• the substrates may be clamped for firmness during cure in those installations where relative movement of the two substrates might be expected.
• an adherent quantity of the adhesive composition is applied to one surface, preferably to both surfaces, and the surfaces are confronted with the adhesive composition therebetween.
• the adhesive should have a thickness less than 60 mils for optimum results.
• the smoothness of the surfaces and their clearance (e.g., in the case of nuts and bolts) will determine the required film thickness for optimum bonding.
• the two metal surfaces and the interposed adhesive composition are maintained in engagement until the said adhesive composition has cured sufficiently to bond the said surfaces.
• EUROPRENETM was added to the masterbatch as set forth in the table below
• the EUROPRENETM polymer, EUROPRENETM SOL T 193A, used was a commercial product of EniChem Elastomers Ame ⁇ cas, Inc.
• EUROPRENETM SOL T 193A is a terblock polymer of styrene and isoprene with polystyrene blocks (25 parts by weight) at the ends and polyisoprene block at the center (75 parts by weight). It is a rubbery solid polymer and has a pellet form.
• EUROPRENETM SOL T 193 A has a reasonable solubility in THFMA A 20 part by weight solution of EUROPRENETM SOL T 193 A in THFMA has been used for formulation convenience.
• TABLE I EUROPRENETM Ladder vs. T-Peel Property
• the above four formulations were prepared in 4 oz. polyethylene jars and allowed to age overnight.
• the formulations were loaded into two-part dispensing equipment (4: 1 side A:side B mix ratio by volume).
• the curative (side B) used here was a benzoyl peroxide containing curing agent.
• the substrate (1" x 4" x 0.032") tested was galvanealed steel.
• the coupons were bent one inch from the end to give a 90 degree angle.
• the coupons were treated with an aqueous lubricant (Chempet 4465 available from ADCHEM) with acid brush according to the following preparation for blank wash:
• T-peel samples were assembled and allowed to cure at room temperature overnight, then postbaked at 325°F for 20 min., cooled at room temperature for 60 min., postbaked again at 250°F for 30 min. After 4 hours of cooling at room temperature, T-peel test was performed on the Instron (Model 4204) at a 2.0 in/min at room temperature. The T-peel test results are shown below:
• Versilok® 262 is a structural adhesive commercially available from Lord Corporation that does not include two distinct tougheners of different M w or EUROPRENE. "COH” designates cohesive (substrate) failure, “TCOH” designates a thin layer of cohesive (substrate) failure and “ADH” designates adhesive failure.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 2000
  • 2000-06-07 EP EP00938197A patent/EP1190011A2/de not_active Withdrawn
  • 2000-06-07 BR BR0011465-0A patent/BR0011465A/pt not_active Application Discontinuation
  • 2000-06-07 WO PCT/US2000/015639 patent/WO2000077109A2/en not_active Application Discontinuation
  • 2000-06-07 MX MXPA01011623A patent/MXPA01011623A/es unknown
  • 2000-06-07 CA CA002376644A patent/CA2376644A1/en not_active Abandoned
  • 2000-06-07 AU AU53273/00A patent/AU5327300A/en not_active Abandoned

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