[go: up one dir, main page]

WO2004085549A2 - Revêtement de qualité optique - Google Patents

Revêtement de qualité optique Download PDF

Info

Publication number
WO2004085549A2
WO2004085549A2 PCT/US2004/008225 US2004008225W WO2004085549A2 WO 2004085549 A2 WO2004085549 A2 WO 2004085549A2 US 2004008225 W US2004008225 W US 2004008225W WO 2004085549 A2 WO2004085549 A2 WO 2004085549A2
Authority
WO
WIPO (PCT)
Prior art keywords
coating
weight
parts
coating composition
composition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2004/008225
Other languages
English (en)
Other versions
WO2004085549A3 (fr
Inventor
Douglas Mcbain
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Omnova Solutions Inc
Original Assignee
Omnova Solutions Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Omnova Solutions Inc filed Critical Omnova Solutions Inc
Publication of WO2004085549A2 publication Critical patent/WO2004085549A2/fr
Publication of WO2004085549A3 publication Critical patent/WO2004085549A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • 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
    • C08F290/06—Polymers provided for in subclass C08G
    • C08F290/067—Polyurethanes; Polyureas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C37/00—Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
    • B29C37/0025—Applying surface layers, e.g. coatings, decorative layers, printed layers, to articles during shaping, e.g. in-mould printing
    • B29C37/0028—In-mould coating, e.g. by introducing the coating material into the mould after forming the article
    • B29C37/0032—In-mould coating, e.g. by introducing the coating material into the mould after forming the article the coating being applied upon the mould surface before introducing the moulding compound, e.g. applying a gelcoat
    • 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
    • C09D155/00—Coating compositions based on homopolymers or copolymers, obtained by polymerisation reactions only involving carbon-to-carbon unsaturated bonds, not provided for in groups C09D123/00 - C09D153/00
    • C09D155/005—Homopolymers or copolymers obtained by polymerisation of macromolecular compounds terminated by a carbon-to-carbon double bond
    • 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
    • C09D175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
    • C09D175/16—Polyurethanes having carbon-to-carbon unsaturated bonds having terminal carbon-to-carbon unsaturated bonds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C37/00—Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
    • B29C37/0025—Applying surface layers, e.g. coatings, decorative layers, printed layers, to articles during shaping, e.g. in-mould printing
    • B29C37/0028—In-mould coating, e.g. by introducing the coating material into the mould after forming the article
    • B29C2037/0035—In-mould coating, e.g. by introducing the coating material into the mould after forming the article the coating being applied as liquid, gel, paste or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
    • B29C67/246—Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM]

Definitions

  • the present invention relates to a transparent composition useful for coating injection molded work pieces.
  • thermoplastic and thermoset articles such as those made from polyolefins, polycarbonates, polyesters, polystyrenes and polyurethanes, are utilized in numerous applications including those for automotive, marine, recreation, construction, office products, and outdoor equipment industries.
  • application of a surface coating to a molded thermoplastic or thermoset article is desirable.
  • molded articles may be used as one part in multi-part assemblies; to match the finish of the other parts in such assemblies, the molded articles may require application of a surface coating that has the same finish properties as the other parts. Coatings may also be used to improve surface properties of the molded article such as uniformity of appearance, gloss, scratch resistance, chemical resistance, weatherability, and the like.
  • surface coatings may be used to facilitate adhesion between the molded article and a separate finish coat to be later applied thereto. Because of the inherent low surface energy of thermoplastics, particularly, polyolefins, they are difficult to paint or coat. Moreover, in view of the variation among the surface properties of individual thermoplastics and the coating compositions to be applied, a method that works with one specific thermoplastic may not work with another. Hence, a variety of methods have been developed to achieve adhesion of coatings to the surface of molded thermoplastics materials.
  • One of the most common methods is to micro-etch the surface of the molded article to generate micro-roughness that will provide adhesion- anchoring sites for the paint or other top and primer coatings. Etching may be done by solvents, which may be incorporated in the paint or coating being applied. The selection of solvent is critical because different solvents etch thermoplastics at different rates, but both over-etching and under-etching must be avoided; insufficient etching results in inadequate adhesion whereas excessive etching can damage the thermoplastic. Excessive etching, exposing the coating to bleeding from the thermoplastic, or exposing the thermoplastic to attack by the solvent all may warp thermoplastic parts. If molded thermoplastics have areas that are highly stressed by the molding process, use of etching solvents can form visible cracks in these areas.
  • thermoplastic part for painting or coating Another method of preparing the surface of a thermoplastic part for painting or coating is through de-glazing.
  • a highly crosslinked (glazed) skin is formed which is resistant to solvent etching.
  • Tumbling with a moderately abrasive media, or blasting with a mildly aggressive grit material, may sufficiently de-glaze the article surface so as to allow satisfactory adhesion of the paint or coating.
  • thermoplastic surface utilizes a chemical reaction to create polar oxidized groups on the thermoplastic surface.
  • surface polarizing methods include coating with an adhesion promoter or subjecting the polyolefin work piece to flame or plasma treatment to make the thermoplastic surface chemically polar so it will bond with the coating.
  • Low polarity thermoplastics also can be oxidatively surface treated using light sensitive chemicals called photosensitizers, followed by exposure to ultraviolet light. UV light cracks the molecules of the photosensitizers to form free radicals. Free radicals are extremely reactive species that combine with oxygen in the air. Oxygen free radicals, in turn, react with the thermoplastic to produce polar groups on the thermoplastic surface.
  • thermoplastic work pieces were formed in a mold, the molded product removed, and a coating was then applied on the surface of the molded work piece by a coating process, such as a surface treatment, primer coating, top coating, painting, etc.
  • a coating process such as a surface treatment, primer coating, top coating, painting, etc.
  • thermosetting resins such as SMC (sheet molding compound) and BMC (bulk molding compound). See e.g., U.S. Pat. Nos. 4,076,788; 4,081 ,578; 4,331 ,735; 4,366,109; and 4,668,460.
  • thermoplastic substrates In view of the predominance of the use of injection molded thermoplastic substrates in the transportation, automotive, marine, recreation, construction, office supply, and lawn and garden manufacturing industries, it is desirable to provide an IMC method for use with injection molded thermoplastic work pieces.
  • thermoplastic work piece in a way which avoids having to apply an additional coating of paint to a preformed part is a dual injection molding technique which involves heating a powdered plastic paint coating material to its plastic phase and then injecting it under pressure into a mold, followed by injecting a thermoplastic substrate material under pressure into the mold to cause the coating material to coat a surface of the mold, thus producing a work piece coated by the plastic paint coating material.
  • Typical IMC compositions are set forth in U.S. Pat. Nos.
  • FRP fiber-reinforced plastics
  • U.S. Pat. No. 4,331 ,735 sets forth a liquid crosslinkable composition having an j average molecular weight of up to about 5000 and a plurality of polymerizable ethylenic double bonds, being essentially free of active hydrogen atoms or being essentially free of isocyanate groups; a material such as a polyisocyanate or a reaction product of a polyisocyanate and an ethylenically unsaturated compound having -NHa groups, -NH and/or -OH groups, said reaction product being free of active hydrogen atoms; and an organic free radical peroxide initiator.
  • coatings include at least one polymerizabie epoxy-based oligomer having two acrylate groups thereon, at least one copolymerizable ethylenically unsaturated monomer such as styrene, and at least one copolymerizable monoethylenically unsaturated compound having a -CO- group and a -NH 2, -NH-, and/or -OH group, as well as polyvinyl acetate, as set forth in U.S. Pat. Nos. 4,414,173 and 4,515,710.
  • Still other coatings include a conductive, thermoset IMC for molded FRP parts, the binder of which comprises at least one polymerizabie epoxy-based oligomer having at least two acrylate groups and at least one copolymerizable ethylenically unsaturated monomer, which provides good flow and coverage during molding, good adhesion, uniform color, good surface quality, and good paintability, as set forth in U.S. Pat. No. 5,614,581.
  • Still other IMC compositions include free radical peroxide initiated thermosetting compositions comprising an epoxy-based oligomer having at least two acrylate end groups and a hydroxy or amide-containing monomer, as set forth in U.S. Pat. Nos. 5,391 ,399; 5,359,002; and 5,084,353.
  • IMC compositions which have appearance or paint-like properties, also are known. Appearance IMC compositions are desirable because they eliminate the additional step, time and cost of applying paint to the surface of an in-mold coated work piece.
  • Appearance IMC compositions are desirable because they eliminate the additional step, time and cost of applying paint to the surface of an in-mold coated work piece.
  • One such appearance coating is disclosed in U.S. Pat. No. 5,736,090, which relates to a method of coating a polyamide work piece by utilizing an IMC composition capable of providing a coating having sufficient durability with respect to adhesion, appearance, and weather resistance, and which functions as a top coating applicable to exterior parts of automobiles or other outdoor applications.
  • the IMC composition comprises, as a vehicle component, a urethane (meth)acrylate oligomer and a polymerizabie unsaturated monomer; a polyisocyanate compound; and a polymerization initiator, where the oligomer itself is a reaction product of an organic polyisocyanate, an organic polyol, and a hydroxyalkyl acrylate and a hydroxyalkyl methacrylate.
  • IMC is the cured in-mold coating composition suitable for use on fiber reinforced thermoplastic (FRP), which comprises a saturated polyester urethane acrylate made from a saturated aliphatic polyester intermediate, a saturated aliphatic urethane group and a saturated hydroxyl (alky!) (meth)acrylate, as set forth in U.S. Pat. No. 5,777,053, the disclosure of which relating to composition is incorporated herein by reference.
  • FRP fiber reinforced thermoplastic
  • the '053 patent relates to the use of a diacrylate ester of an alkylene diol, a saturated (cyclo)aliphatic (meth)acrylate, and a vinyl substituted aromatic to impart paint coating type properties to the IMC composition, such as hardness, water resistance, low shrinkage, and high gloss.
  • paint coating type properties such as hardness, water resistance, low shrinkage, and high gloss.
  • crosslinking agents such as triallylcyanurate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate and the like may be utilized.
  • the components are reacted in the presence of an initiator, such as a peroxide, to chain extend and to form the thermoset saturated polyester urethane acrylate coating resin.
  • the cured resin is a clear IMC composition, which may be pigmented using various pigments, colorants, etc., to yield a desired end color and opacity. Appearance or paint-like properties of these IMCs are achieved by avoiding various components, especially aromatic compounds such as aromatic polyesters and/or polyether urethane intermediates, aromatic epoxy-based resins and the like. These compositions have been used successfully to form a paint-free FRP end product laminate.
  • the FRP parts were prepared in a closed mold from polyester SMC.
  • the IMC compositions were applied immediately following SMC cure by opening the mold, injection or otherwise applying the coating onto the FRP molding, followed by re-closing of the mold.
  • a free radical initiator as a chain extension component, in conjunction with the curing monomers of the described in-mold coatings, is thought to be important to the quality of the appearance and the properties obtained. While not wishing to be bound by any theory, use of a free radical initiator, such as a peroxide compound, is believed to promote adhesion of the IMC composition to the surface of the polyolefin work piece.
  • the free radicals generated within the coating composition may react with the surface of the polyolefin in some manner and thereby permit a bonding or adhesion of the coating to the polyolefin.
  • thermoplastic substrates A process of in-mold coating thermoplastic substrates has been developed.
  • In-mold coating of polyolefin work pieces whereby the coating composition has good flow and coverage during molding, good adhesion, uniform color, good surface quality, and, if necessary, good paintability, may be successfully achieved during injection molding processes by increasing only slightly, or not at all, the temperature at which the thermoplastic substrate is injection molded and through the use of the above-described, standard in- mold coatings, comprising a free radical initiator, such as a peroxide compound.
  • FIG. 1 is a side view of one embodiment of the molding apparatus of the present invention.
  • the present invention provides a composition suitable for use as a transparent coating on an injection molded thermoplastic work piece.
  • the cured composition is made from ingredients that include hydroxypropyl methacrylate, isobornyl acrylate, styrene, an aliphatic polyester urethane diacrylate and hexanediol diacrylate. These components can be mixed in the presence of an initiator and optional cure accelerators to form a thermoset resin.
  • the cured resin is suitable for use as an optical quality IMC composition unless pigmented.
  • optical quality means having clarity and light transmission properties that are equal to or better than those of glass.
  • the coating can provide improved impact resistance.
  • the composition finds applications in the coating of many thermoplastics, particularly transparent thermoplastics, which can be used as covers for lights in automobiles, traffic lights, and the like.
  • a first component of the coating composition is a saturated aliphatic polyester intermediate urethane which contains acrylate groups, generally at the terminal portions of the polymer.
  • the polyester intermediate of the urethane can be made from aliphatic dicarboxylic acids or aliphatic anhydrides and glycols.
  • the aliphatic dicarboxylic acids and anhydrides can have from 1 to 15 carbon atoms and are desirably saturated (with specific examples including carbonic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, the anhydride counterparts thereof, and the like, with adipic acid generally being preferred.
  • glycols or diols generally have from 2 to 15 carbon atoms and are saturated, with specific examples including ethylene glycol, propylene glycol, 1 ,3-butylene glycol, 1 ,4- butylene glycol, pentane diol, hexane diol, cyclohexanedimethanol dipropylene glycol, 2,2-dimethyl-1 ,3-propane diol, diethylene glycol, pinacol, and the like.
  • Preferred glycols include ethylene glycol and neopentyl glycol.
  • the saturated aliphatic polyester intermediate generally has a number average molecular weight (M n ) of from about 1000 to about 5000, desirably from about 1500 to about 2000.
  • An aliphatic polyisocyanate is typically reacted with the saturated polyester intermediate to form a polyurethane type resin.
  • the aliphatic portion is saturated and has from about 5 to 18 carbon atoms. Examples include isophorone diisocyanate (IPDI), hexamethylene diisocyanate, cyclohexyl diisocyanate, and the like, with IPDI being preferred.
  • the average equivalent ratio of NCO groups to OH end groups of the intermediate is approximately from about 1.5 to about 2.5, desirably from about 1.9 to about 2.1 , and preferably about 2.0.
  • Such amounts are generally sufficient to form an isocyanate-terminated polyurethane prepolymer which is then reacted with a hydroxyalkyl acrylate to form the saturated polyester urethane containing a (meth)acrylate generally at the terminal portions of the polymer chain.
  • the (meth)acrylates can generally have an ester portion containing from 2 to 10 carbon atoms, such as ethyl, propyl, n-butyl, ethylhexyl, and the like, with ethyl and propyl being preferred.
  • Polyester urethane acrylates which contain unsaturated and/or aromatic polyester intermediates, as well as aromatic and/or unsaturated diisocyanates, generally are avoided because they may yield a coating with a tendency to yellow and degrade on aging.
  • the polyester urethane acrylates are hence substantially free of such compounds, meaning that they generally contain unsaturated and/or aromatic polyester intermediates in an amount less than 50 or 25 mole percent by weight, desirably less than 10 percent by weight, and preferably less than 5 percent by weight, or none at all, of such units or groups based upon the total weight of such polymer(s).
  • the polyurethane intermediate generally contains less than 50 percent by weight and generally less than 25 percent by weight, and preferably less than 10 percent or 5 percent by weight, or none al all of polyether and/or epoxy groups based upon the total weight of the polyester urethane acrylates.
  • hexanediol diacrylate Another component is hexanediol diacrylate (HDODA).
  • the acrylate groups are contained on the ends of the hexanediol and can be derived from (meth)acrylic acid.
  • the amount of the hexanediol diacrylate is generally from about 2 to about 25 parts by weight (pbw), desirably from about 5 to about 20 pbw, and preferably from about 10 to about 15 pbw per 100 total pbw of the polyester urethane acrylate.
  • the polyester urethane diacrylate may be obtained in a blended state with the hexanediol diacrylate, a commercially available example of which is CN-963B80 blend (Sartomer Co., Inc.; Exton, Pennsylvania) which contains 80 pbw polyester urethane diacrylate oligomer in 20 pbw SR238 HDODA.
  • CN-963B80 blend Stemomer Co., Inc.; Exton, Pennsylvania
  • Various compounds or components are utilized to react with the polyester urethane acrylate and hexanediol diacrylate to form the thermoset resin of the present invention.
  • One such component is isobornyl acrylate (IBOA).
  • the amount of the IBOA is generally from about 10 to about 100 pbw, desirably from about 25 to about 90 pbw, and preferably from about 40 to about 80 pbw per 100 total pbw of the polyester urethane acrylate.
  • Another component is hydroxypropyl methacrylate (HPMA).
  • HPMA hydroxypropyl methacrylate
  • the amount of the HPMA is generally from about 2 to about 25 pbw, desirably from about 5 to about 20 pbw, and preferably from about 10 to about 15 pbw per 100 total pbw of the polyester urethane acrylate. This compound is utilized in addition to the hydroxyalkyl methacrylates utilized to form the polyester urethane acrylate resin.
  • Still another component is styrene.
  • the amount of the styrene is generally from about 10 to about 100 pbw, desirably from about 20 to about 80 pbw, and preferably from about 30 to about 50 pbw per 100 total pbw of the polyester urethane acrylate.
  • the coating composition is an optically clear coating for use in, inter alia, IMC of thermoplastic parts.
  • the clear coating can be colored with a pigment, a colorant, etc., in a desired or effective amount to yield a desired color, tint, hue, or opacity.
  • Pigments and pigment dispersions are known in the art and include, for example, Ti0 2 , carbon black, phthalocyanine blue, phthalocyanine red, chromium and ferric oxides, and the like.
  • the coating composition is zinc and cobalt ester octoate as cure accelerators.
  • These accelerators are conventionally acquired in solutions in mineral oil. Preferred preparations of these accelerators include 12-18% by weight solutions.
  • the amount of the accelerators is generally from about 0.1 to about 4.0 pbw, desirably from about 0.3 to about 2.0 pbw, and preferably from about 0.5 to about 1.5 pbw per 100 total pbw of the polyester urethane acrylate.
  • compositions of the present invention also can contain conventional additives, and fillers, etc., in conventional amounts.
  • various cure inhibitors such as benzoquinone, hydroquinone, methoxyhydroquinone, p-t- butylcatechol, and the like
  • various light stabilizers can be utilized such as, for example, the various hindered amines (HALS), substituted benzophenones, and substituted benztriazoles, and the like.
  • Lubricants and mold release agents are generally utilized with specific examples including various metal stearates, such as zinc stearate or calcium stearate or phosphonic acid esters. Reinforcing fillers such as talc can be utilized.
  • Talc has also been found to help promote adhesion of the IMC composition to the FRP substrates.
  • Another additive is a hardener and thixotrope such as silica.
  • a commercial mold release agent may also be used in the composition. Suitable mold release agents include those that are colorless upon curing of the composition.
  • a preferred mold release agent is ZelecTM LA-2 lauric acid- modified phosphoric acid (Stepan Co.; Northfield, Illinois).
  • the polyester urethane acrylate and the other curing monomers or components can be chain extended through the utilization of a free radical initiator such as a peroxide.
  • a free radical initiator such as a peroxide.
  • suitable free radical initiators include t-butyl perbenzoate (TBPB), t-butyl peroctoate in diallyl phthalate, diacetyl peroxide in dimethyl phthalate, dibenzoyl peroxide, di(p-chlorobenzoyl) peroxide in dibutyl phthalate, di(2,4-dichlorobenzoyl) peroxide in dibutyl phthalate dilauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide in dibutyl phthalate, 3,5-dihydroxy-3,4-dimethyl-1 ,2- dioxacyclopentane, t-butylperoxy(2-ethyl he
  • a preferred initiator is TBPB.
  • the initiator should be used in an amount sufficient to overcome the effect of the inhibitor and to cause curing of the ethylenically unsaturated compounds.
  • the initiator is used in an amount of up to about 5.0% or from about 0.2 to about 4.0, desirably from about 0.3 to about 3.0%, and preferably from about 0.5 to about 2.0% by weight based on the total weight of all of the ethylenically unsaturated components employed in the I IMC compositions.
  • the reaction of the polyester urethane acrylate with the curing components in the presence of the peroxide initiator is generally at a temperature of from about 38°C (100°F) to about 149°C (300°F), and desirably from about 66°C (150°F) to about 93°C (200°F).
  • the coating composition may be prepared in conventional mixing equipment.
  • the blended polyester urethane acrylate is mixed with the styrene, the IBOA, and the HPMA. After these compounds are mixed, the zinc and cobalt ester octoate accelerators, the mold release agent and any of the above-noted fillers and additives such as cure inhibitors, light stabilizers, lubricants, etc., are added and mixed. Initiator such as TBPB is added last.
  • a polyacrylate ester of a polyol can be present in the polyester urethane acrylate from the supplier.
  • one or more pigments, colorants, etc. can be utilized in suitable amounts.
  • a carrier for example, a polyester
  • Any conventional or suitable mixing vessel can be utilized, and the various components and additives mixed until the compounds are blended. Even if pigments are not contained in the blend, the mixture at this point is not clear.
  • the mixed ingredients are coated onto an injection molded thermoplastic part with the IMC composition heated to a cure temperature. Suitable cure temperatures generally range from about 38° to about 149°C (from about 210° to about 300°F). Upon cure or chain extension, the IMC composition becomes clear.
  • the components of the coating composition can be prepared in two separate batches to prolong the shelf-life of the two components.
  • the accelerators are separated from the initiator.
  • This method of preparation includes creating a masterbatch including the HPMA the (IBOA), the styrene, the aliphatic polyester urethane diacrylate, and the hexanediol diacrylate (e.g., in the form of the CN-963B80 mixture).
  • the masterbatch may then be divided into an A and a B component.
  • the cobalt and zinc accelerators can be added to the A component while the TBPB and the mold release agent can be added to the other component.
  • the two components then can be added together into the mold at the desired time.
  • the coating composition of the present invention finds particular utility in the IMC of injection molded thermoplastic parts. Such a process is described more in depth in U.S. Publ. No. 2002/0039656, the disclosure of which is incorporated by reference.
  • FIG. 1 A molding apparatus is shown in FIG. 1 , and is generally designated 10.
  • Molding apparatus 10 includes a first mold half 20 which remains in a stationary or fixed position relative to a second movable mold half 30.
  • FIG. 1 shows the mold halves in an open position.
  • First mold half 20 and second mold half 30 are adapted to slidingly mate or nest to a mold cavity 40.
  • Mold halves 20,30 mate along surfaces 24 and 34 when they are in the closed position, forming a parting line.
  • Movable mold half 30 reciprocates generally along a horizontal axis relative to the first or fixed mold half 20 by action of a clamping mechanism 70 with a clamp actuator 72 such as through a hydraulic or mechanical actuator as known in the art.
  • clamping mechanism 70 is capable of generating an operating pressure in excess of the pressures generated or exerted by either one of first composition injector 50 and second composition injector 60.
  • first composition injector 50 is a typical injection molding apparatus which is capable of injecting a thermoplastic or thermosetting composition into the mold cavity. First composition injector 50 is shown in a "backed off" position but can be moved horizontally so that nozzle or resin outlet 58 mates with mold half 20 and can inject into mold cavity 40.
  • First composition injector 50 is illustrated as a reciprocating-screw machine.
  • a first (resinous) composition may be placed in hopper 52 and rotating screw 56 moves the composition through the heated extruder barrel 54, where the material is heated above its melting point.
  • screw 56 acts as an injection ram and forces the extrudate through nozzle 58 into the mold.
  • Nozzle 58 generally has a non-return valve at the nozzle or screw tip to prevent backflow into screw 56.
  • Nozzle 58 may also contain means to heat or cool to better control the temperature and thus flow properties of the extrudate.
  • First composition injector 50 is not limited to the embodiment shown in Fig. 1 but can be any apparatus capable of injecting a flowable (e.g., thermoplastic or thermosetting) composition into mold cavity 40.
  • the injection molding machine can have a mold half movable in a vertical direction, such as in a stackmold with center injection.
  • Other suitable injection molding machines include many of those available from Cincinnati-Milacron, Inc.
  • a predetermined quantity of a first composition 80 is injected into the mold cavity from the first composition injector 50, forming a substrate or workpiece.
  • the substrate formed in the mold cavity from the first composition has at least a show surface and an opposite surface.
  • a coating composition is then introduced into the mold cavity from the second injector 60. This injection is begun after the previously injected material has begun to cool.
  • Resins useful as substrates in the practice of the invention are numerous, although thermoplastics are preferred.
  • the substrate resin preferably is amenable to being injection molded in commercially available equipment.
  • Resins useful in the practice of the invention include PE, polystyrene, PBT and PBT alloys, PP, polyurethane, PMMA, ABS copolymer, PVC, polyesters, polycarbonates, PP/PS or polypropylene polystyrene alloys, nylon, polyacetal, SAN, acrylics, cellulosics, polycarbonate alloys and PP or propylene alloys. Other combinations of these materials may be used.
  • a particularly preferred substrate resin is polycarbonate, which together with the optical quality coating composition, provides a clear, colorless part for use in applications demanding such characteristics.
  • the resulting masterbatch was then separated into an A and a B component.
  • the A and B component included the components listed in Tables 2 and 3, respectively.
  • Polycarbonate panels were prepared in a 13 cm x 51 cm x 0.3 cm mold using CALIBRETM 20-115 polycarbonate resin (The Dow Chem. Co.; Midland, Michigan).
  • the coating components were injected into the closed mold at a mold temperature of 93°C and cured for 180 seconds at 4.5 Mg of clamp pressure.
  • the resulting coating provided a colorless optical quality coating composition displaying good adhesion, water resistance, UV resistance and hardness.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Paints Or Removers (AREA)
  • Macromonomer-Based Addition Polymer (AREA)

Abstract

La présente invention a trait à une composition de revêtement formée à partir d'ingrédients comprenant du méthacrylate d'hydroxypropyle (HPMA), de l'acrylate d'isobornyle (IBOA), du styrène, du diacrylate d'hexanediol (HDOA), et une résine uréthanne diacrylique de polyester aliphatique. Des revêtements obtenus à partir de cette composition sont de qualité optique et présentent une excellent adhérence aux articles en matière thermoplastique.
PCT/US2004/008225 2003-03-19 2004-03-18 Revêtement de qualité optique Ceased WO2004085549A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US45582003P 2003-03-19 2003-03-19
US60/455,820 2003-03-19

Publications (2)

Publication Number Publication Date
WO2004085549A2 true WO2004085549A2 (fr) 2004-10-07
WO2004085549A3 WO2004085549A3 (fr) 2004-11-18

Family

ID=33098071

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2004/008225 Ceased WO2004085549A2 (fr) 2003-03-19 2004-03-18 Revêtement de qualité optique

Country Status (1)

Country Link
WO (1) WO2004085549A2 (fr)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
MX173523B (es) * 1981-11-02 1994-03-11 Gencorp Inc Mejoras en composicion de revestimiento termoendurecible y metodo
US4561950A (en) * 1984-04-02 1985-12-31 Desoto, Inc. Post-formable radiation-curing coatings
US5777053A (en) * 1997-01-17 1998-07-07 Gencorp Inc. In-mold coating compositions suitable as is for an end use application
US6617033B1 (en) * 2000-07-12 2003-09-09 Omnova Solutions Inc. Method for in-mold coating a polyolefin article

Also Published As

Publication number Publication date
WO2004085549A3 (fr) 2004-11-18

Similar Documents

Publication Publication Date Title
US6617033B1 (en) Method for in-mold coating a polyolefin article
CA2224779C (fr) Composition de revetement sous moule prete a etre appliquer
JP4914559B2 (ja) インモールドコーティング射出成型された熱可塑性基体の最適化
US6863981B2 (en) In-mold appearance coatings for nylon and nylon based thermoplastic substrates
US20040071980A1 (en) Method for in-mold coating a polyolefin article
EP1656429B1 (fr) Revetement dans le moule consistant a deposer une couche de base
WO2004085549A2 (fr) Revêtement de qualité optique
JP4420841B2 (ja) 型内被覆用組成物及び型内被覆成形品の製造方法
JP4456024B2 (ja) 型内被覆成形用組成物及び型内被覆成形品の製造方法
JP4431514B2 (ja) 型内被覆組成物及び型内被覆成形品の製造方法
JPH0570712A (ja) 型内被覆組成物
JP2016022591A (ja) 型内被覆組成物、型内被覆成形体及び塗装物品
WO2005108512A1 (fr) Revetement dans le moule a adhesion amelioree
WO2004035697A1 (fr) Revetement conferant une surface tactile a des articles moules

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DPEN Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed from 20040101)
122 Ep: pct application non-entry in european phase