Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
  • C09D175/04—Polyurethanes
  • C09D175/06—Polyurethanes from polyesters
• • 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
  • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
  • C08F283/006—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polymers provided for in C08G18/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
  • C08G59/4246—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof polymers with carboxylic terminal groups
  • C08G59/4269—Macromolecular compounds obtained by reactions other than those involving unsaturated carbon-to-carbon bindings

Definitions

• This invention relates to epoxy ester urethane polymers having acrylic portions grafted thereto. More particularly, it relates to coating compositions containing such polymers.
• Epoxy graft acrylic water-based primer surfacers are claimed in U.S. 4,564,648, of January 14, 1986 - Huybrechts and Vlerainckx, but they do not include urethane grafts.
• the present invention is an improvement over this one in giving better chip resistance over well cured electrocoats. for instance. This requires a careful balance of flexibility and hardness in different portions of the polymer.
• the present invention provides a dispersion in water, in percentages by weight based on the total dispersion, of:
• organic solvents such dispersion having not more than 10% volatile organic solvents plus amines, and
• the present invention is made possible by a new method of synthesis of an epoxy ester urethane graft acrylic polymer.
• the process involves the synthesis of a linear epoxy ester formed by reaction at 80-190°C of an oxirane terminated bisphenol A epoxy resin with aliphatic diacid-functional linear urethane esters and monoacids in approximately stoichiometric proportions so that all the oxirane groups and acid groups have reacted.
• the reaction is done in a minimum amount of an organic solvent, preferably aromatic for ease of stripping, preferably using a small percentage of a tertiary araine as catalyst.
• an acid functional acrylic is grafted onto the epoxy ester urethane using a peroxide or azo initiator. Grafting onto the epoxy ester urethane is believed to go via hydrogen abstraction of activated carbon-hydrogen bonds.
• the acid functionality on the epoxy ester urethane is neutralized with a tertiary amine (50-200% neutralization), the polymer is dispersed in deionized water and the excess organic solvents are distilled off.
• epoxy ester urethane acrylic dispersions then contain a minimum of organic solvents, so as to be able to formulate primer compositions, preferably with no more than 5% organic volatiles, including amines.
• primer surfacers When combined with water soluble or dispersible crosslinkers, like hexamethoxymethylmelamine, pigments and extenders, primer surfacers can be formulated which show good corrosion resistance over bare steel, an excellent balance of hardness, flexibility, improved anti-chipping properties, good topcoat hold-out and appearance.
• primer surfacers can be baked for 30 min at from 160°C to 200°C. still retaining their basic properties.
• the primers can be applied by conventional or electrostatic spraying.
• rheology control agents and flow agents can be used. Silica or clay pastes are quite successful for rheology control to prevent pinholing and sagging, and water soluble or dispersible linear or branched polyethylene glycols or polypropyleneglycols are efficient for flow properties.
• the primer surfacers show excellent initial and wet adhesion over bare steel and cathodic electrodeposited primers. Adhesion and hold-out of conventional topcoats (polyester, alkyd. acrylic) is very good over broad temperature ranges. Hold-out is the resistance to interpenetration at the interface between the layers of primer surfacer and topcoat applied in organic solvents.
• isocyanate hexamethylene diisocyanate
• HDI isophorone diisocyanate IPDI hydrogenated bisphenyl methane HPMDI diisocyanate trimethyl hexane diisocyanate
• TMHDI toluene diisocyanate TDI bisphenyl methane diisocyanate PMDI m or p xylylenediisocyanate m or p XDI
• glycols ethylene glycol EG propylene glycol DG
• succinic anhydride SA maleic anhydride MA phthalic anhydride- PA tetrahydro phthalic anhydride THPA hexahydro phthalic anhydride HHPA methyl hexahydro phthalic MHHPA anhydride
• MAAM, BMAAM and MMAM acrylaraide and methacrylamide AM and MAM
• Epon 1001 epoxy resin from Shell 1800 Epon 1001 epoxy resin from Shell 1800
• IP Isopropanol
• DBTDL dibutyltin dilaurate
• Pluriol P 900 polypropylene oxide mol. weight 900 (reactive diluent) 2.26 BASF
• Aerosil 200 fumed silica 0.87 Degussa Blanc Fixe barium sulfate .0.13 Sachtleben 30 Aluminum silicate 2.56 Titanium dioxide pigment 6.73 Carbon black 0.034 Iron oxide 0.145 Deionized water 3.941 Pigment to binder ratio (P/B) 74.3 / 100 Binder ratio: 76.5/15.3/8.2: Resin of Example 2/ Cymel 303/Pluriol P 900.
• the above mixture is ground to a fineness smaller than 15 ⁇ m. Next there is added deionized water to obtain a package viscosity of 100 to 150 sec DIN cup 4 at 20°C.
• PANEL PREPARATION The products of Examples 7-9 were reduced with deionized water to a spray viscosity of 20 seconds DIN cup 4 at 20°C.
• the coating composition obtained was sprayed over a cataphoretic electrocoated panel at a thickness of 35 ⁇ m dry film thickness and cured at a temperature of 170°C for 25 minutes.
• the obtained primer film was coated with different topcoats including alkyd/melamine//acrylic//melamine color coat - clear coat resulting in excellent adhesion gloss, flow and

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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)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Paints Or Removers (AREA)
• Macromonomer-Based Addition Polymer (AREA)

Applications Claiming Priority (4)

Publications (2)

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• 1987
  • 1987-08-28 JP JP50026787A patent/JPH01500676A/ja active Pending
  • 1987-08-28 WO PCT/US1987/002116 patent/WO1988001628A1/en not_active Application Discontinuation
  • 1987-08-28 EP EP19870908023 patent/EP0280730A4/en not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

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