MXPA98002113A - Compositions of coating resistant to the impact of the abrasion, method for the same and article recubie - Google Patents

Abstract

A curable coating composition resistant to damage induced by impact abrasion comprising: A) An oligomeric or polymeric component comprising aliphatic ester or other aliphatic ether groups having a plurality of reactive functionalities thereon and having a reactive functionality between and 5 and an equivalent weight of between 150 and 750, and B) a compound comprising a plurality of groups that are reactive with the reactive functionality on the component (A). Also included are methods for obtaining the coating composition and a coated article having on it a coating composition as described

Description

COMPOSITIONS OF COATING RESISTANT TO THE IMPACT OF THE ABRASION, METHOD FOR THE SAME AND COATED ARTICLE Related requests This request is a continuation in part of United States Series No. 08 / 698,524, filed on August 15, 1996, which is a continuation in part of United States Series No. 08 / 550,880, filed on October 6, 1995, now abandoned, and United States Series No. 08 / 698,526, filed on August 15, 1996, which is a continuation in part of United States Series No. 08 / 686,929, filed on October 6, 1995.

Field of the Invention The invention relates to curable coating compositions based on polymeric or oligomer components having a highly defined architecture for imparting specific physical characteristics to the coating.

BACKGROUND OF THE INVENTION Curable coating compositions such as thermosetting coatings are widely used in the coatings art. They are often used for top layers in the industrial and automotive coatings industry. Coatings of color-plus-clear coatings are particularly useful as top coatings where exceptional gloss, depth of color, clarity of the image, or special metallic effects are desired. The automotive industry has made extensive use of these coatings for automotive body panels and plastic components. It is essential that the coatings are durable and resistant to weathering factors such as environmental degradation including etching acid from the environment.

In addition to weathering, other characteristics are desirable. For example, it may be desirable to provide a coating that has a high degree of flexibility. This can be particularly advantageous if the substrate on which the coating is placed is flexible on its own, as is the case with plastics, rubber or textile substrates.

In the case of coatings for plastics, additional operating characteristics are desired. These coatings must exhibit extreme flexibility at low temperatures to facilitate bending together with the plastic substrate at the time of impact or deformation. A preferred plastic within the automotive components market is the thermoplastic polyolefin (TPO). TPO is used as the substrate for bumpers, coatings or veneers, bands and other moldings in automobiles and has operational challenges for a coating because conventional coatings can easily be scraped off the TPO substrate. This damage can result from the contacts of bump bumpers with other vehicles, supermarket trolleys, parking meters or other objects. The damage is evident when removing the coating layers from the substrate that exposes the plastic and results in a significant cosmetic defect. It is recognized that these defects are a problem that advances in the industry.

The present invention is directed to coating compositions comprising oligomeric and polymeric components of a specific architecture that provides the flexibility of temperature sufficiently low for applications on plastics and also offers a high degree of resistance to impact abrasion damage, like the one that is evidenced in the TPO substrates.

Description of the Drawings Figure 1 illustrates the test device that is used to test paint damage induced by coating impact.

Compendium of the Invention In accordance with the present invention, a curable coating composition resistant to damage induced by the impact of abrasion is provided. Damage to paint induced by the impact of abrasion is also referred to in the industry as damage or graying to paint induced by friction. According to the present invention, a coating composition is formed comprising: (A) an oligomeric or polymeric component of a defined architecture and (B) a compound comprising a plurality of groups that are reactive with the reactive functionality on the polymeric component or oligomeric (A).

The oligomeric or polymeric component (A) has an architecture that provides flexibility within a cured film and has a reactive functionality thereon. The reactive functionality on the oligomeric or polymeric component is selected from the group consisting of. hydroxyl, epoxy, isocyanate, carboxy, primary carbamate, amine, and mixtures thereof. The oligomeric or polymer component has an equivalent weight of between 150 and 750 and a defined number of reactive functional groups.

The compound (B) comprising a plurality of groups that are reactive with the reactive functionality on the polymeric or oligomer component (A). The reactive groups on (B) include active methyl or methylalkoxy groups on aminoplast surfactants or on other compounds such as phenol / formaldehyde adducts, isocyanate groups, siloxane groups, epoxy, carboxylic acid, cyclic carbonate and anhydride groups. The present invention provides coatings highly resistant to impact abrasion having a good combination of properties such as durability, hardness and resistance to scratching, scratching, solvents and etching acid. The coating compositions according to the invention can also provide low levels of VOC and can be used to prepare coatings having excellent flexibility for use on a variety of flexible substrates.

Detailed description of the invention In accordance with the present invention, a coating composition is formed comprising (A) an oligomeric or polymeric component of a defined architecture having an aliphatic ester or aiiphatic ether groups and compound (B) comprising a plurality of groups that are reactive with the reactive functionality on the oligomeric or polymer component (A). The component (A) has an average functionality between 2 and 5 and has an equivalent weight between 150 t 750. The architecture of the oligomeric and polymeric component (A) provides the cured coating composition with a high degree of flexibility.

The oligomeric and polymer component (A) comprises a component according to one of the following formulas: I) X-L-X 'wherein X and * may be the same or different and represent the degradable functionality selected from the group consisting of hydroxyl, amino, primary carbamate, isocyanate, epoxy, carboxyl and mixtures thereof, and L represents a segment comprising one or more units selected from the group consisting of eliphatic ester groups, aliphatic esters derived from lactones, aliphatic ester groups and mixtures thereof, or; II Z- (Ln -Y) n where Z represents a linking group comprising a diol, polyol, diisocyanate or polyisocyanate, Y represents a degradable functionality selected from the group consisting of hydroxyl, amine, primary carbamate, isocyanate, epoxy, carboxyl and mixtures thereof, and Ln represents one or more units selected from the group consisting of aliphatic ester groups , esters derived from lactones, aliphatic ether groups and mixtures thereof, wherein each Ln can be the same or different, and n is the functionality of the polymer or oligomer (A) and is number between 2 and 5, preferably between 2.0 and 3.6, o; III) Z- (Ln-x -Y) n-x Yx wherein Z represents u-linking group comprising a diol, polyol diisocyanate or polyisocyanate, Y represents a degradable functionality selected from the group consisting of hydroxyl, amine, primary carbamate, isocyanate, epoxy, carboxyl and mixtures thereof , and L represents one or more units selected from the group consisting of aliphatic ester groups, esters derived from lactones, aliphatic ether groups and mixtures thereof, wherein each Ln may be the same or different, and n is the functionality of the polymer or oligomer (A) and is number between 2 and 5, preferably between 2.0 and 3.6, and x is the number of functional end groups that do not contain a chain extension segment and is a number between 0 and n.

The value of n can be affected not only by the functionality of the group Z, but can also be modified through the reaction of a portion of the group Z with terminal groups of non-functionality. For example, a polyisocyanate having a functionality of 3.6 can be reduced to 3.1 by reacting a fraction of the isocyanate with a non-functional terminal group such as an alcohol.

In formula II and III, z may be any dio or polyol. Useful examples include but are not limited to 1, 6-hexane diol, trimethylolpropane, diethylene glycol, pentaerythritol and diol or substituted carbamate polyol, such as the diol obtained by reacting glycerin carbonate and ammonia.

In one embodiment of Formula I, a hydroxy alkyl carbamate is used for the cleavage of the e-caprolactone ring. X represents the primary carbamate, L represents the e-capropactone derived from the polyester segment and X 'represents the hydroxyl groups.

In one embodiment of Formula I, a hydroxy alkyl carbamate is used for the ring cleavage of e-caprolactone. The X represents a carba before primary, L represents an e-caprolactone derived from the polyester segment and X 'represents hydroxyl groups.

In one embodiment of Formula II, Y is hydroxyl, L is an e-caprolactone derived from the polyester and Z is a polyol. Examples of suitable polyols include diethylene glycol and trimethylolpropane (TMP) Diethylene glycol and TMP extended with e-caprolactone is commercially available from Union Carbide, under the trademark of Tone® polyols.

In an alternative embodiment of Formula II, Y is a primary carbamate, L is based on an e-caprolactone derived from a polyester, and Z is diisocyanate or polyisocyanate or mixture thereof, In one embodiment of Formula III, Z is polyisocyanate and a portion of the isocyanate is attached to a primary carbamate and the L group is a lactone derived from polyester. Both Y and Yx are primary carbamates.

In an alternative embodiment of Formula III, the glycerin carbonate is reacted with ammonia followed by the reaction of e-caprolactone. In this embodiment, Z represents the reaction product of glycerin carbonate and ammonia, and L represents the repeated ester groups and Y represents the functional groups of hydroxyl and carebamate.

Component (A) also comprises a mixture of any of the compositions according to formulas I, II, and III. The oligomeric and polymeric components (A) according to formulas I, II and / or III can be combined with other resins having the architecture of component (A), as such, but, without being limited to polyester and acrylic resins and polymers, and added to the coating compositions to obtain the advantages, particularly the advantage of the flexibility in a cured film provided by the present invention.

In a preferred embodiment, the oligomeric components described in formula (I) are compounds having a primary carbamate functionality, or a group that can be converted to a primary carbamate group and hydroxyl functionality. The oligomeric components according to formula (I) can be the reaction product of: (a) (i) a compound having at least one carbamate group (or a group that can be converted to carbamate) and an active hydrogen group reactive with a lactone or a hydroxy carboxylic acid, and (a) (ii) a lactone or hydroxy carboxylic acid.

The primary carbamate groups can generally be characterized by the formula: 0 -0-NH2 The oligomeric component (I) can be formed by the reaction of a lactone or hydroxy carboxylic acid with a compound having an active hydrogen group capable of undergoing a condensation reaction with the acid group of the hydroxy carboxylic acid or the rupture of the lactone ring (for example, hydroxyl, amine, acid) and a carbamate or a group that can be converted to a primary carbamate. When a compound having an active hydrogen group and a group that can be converted to a carbamate is used to react with the lactone or hydroxy carboxylic acid, the conversion of the group to a carbamate can be achieved during or after the reaction of the ring rupture.

Compounds having a carbamate group and an active hydrogen group are known in the art. The hisroxypropyl carbamate, for example, is well known and commercially available. Amino carbamates are described in U.S. Patent 2,842,523. alternatively, these compounds can be prepared starting with a compound having an active hydrogen and a group that can be converted to a primary carbamate as described below, and then converting that group to the primary carbamate before starting the reaction with the lactone or the hydroxy carboxylic acid.

The groups which can be converted to carbamates include the cyclic carbonate groups, epoxy groups and unsaturated bonds. The cyclic carbonate groups can be converted to carbamate groups by reaction with ammonia, which ring opens the cyclic carbonate to form a β-hydroxy carbamate. The epoxy groups can be converted into carbamate groups by first becoming a cyclic carbonate group by reaction with C? 2. This can be done at any pressure, from atmospheric to supercritical pressures of C 2, but preferably under high pressures (e.g., 60-150 psi pounds per square inch). The temperature for this reaction is preferably 60-150 ° C. Useful catalysts include any that activates an oxirane ring, such as tertiary amine or quaternary limes (e.g., tetramethyl ammonium bromide), combinations of complex organotin halides and alkyl phosphonium halides (e.g. (CH3) 3SnI, Bu.Snl, Bu.PI, and (CH3) .PI), potassium salts (eg, K2 C03, Kl) preferably in combination with crowned ethers, tin octoate, calcium octoate and similar. The cyclic carbonate group can then be converted into a carbamate group as described above. Any unsaturated bond can be converted into carbamate groups by a first reaction with peroxide to become an apoxia group, then with CO2 to form a cyclic carbon, and then with ammonia to form the primary carbamate.

Other groups such as hydroxyl groups or isocyanate groups can also be converted into carbamate groups. However, if the groups were present on the compound and then converted to carbamate after reaction with the lactone or the hydroxy carboxylic acid, they would have to be blocked, so that they would not react with the lactone, the hydroxy carboxylic acid or with the active hydrogen groups. When blockage of these groups is not viable, the conversion to carbamate would have to be completed before the reaction with the lactone or the hydroxy carboxylic acid. The hydroxyl groups can be converted to carbamate groups by reaction with cyanic acid (which can be formed in situ by thermal decomposition of the urea) to form a primary carbamate group (ie, unsubstituted carbamates). This reaction occurs preferably in the presence of a catalyst as is known in the art. A group of hidoxyl can also be reacted with phosgene and then with ammonia to form a compound having a primary carbamate group (s). Finally, the carbamates can be prepared by the transesterification approach wherein the hydroxyl group reacted with an alkyl carbamate (for example, methyl carbamate, ethyl carbamate, butyl carbamate) to form a compound containing a carbamate group primary. This reaction is carried out under heat, preferably in the presence of a catalyst such as an organometallic catalyst (for example, dibutyltin dilaurate) Other techniques for the preparation of carbamates are also known in the art and are described, for example in P .Adams & F. Baron, "Esters of Carbamic Acid", Chemical Review, v. 65, 1965.

A less preferred method for converting OH groups into carbamate groups is to selectively react a compound such as a hydroxyalkyl carbamate with a diisocyanate to form a carbamate-capped isocyanate derivative. The reaction of the derivative with a terminal hydroxyl group results in a terminal carbamate group.

A preferred class of compounds having an active hydrogen group and a group which can be converted to a carbamate is that of the hydroxyalkyl cyclic carbonates.

The hydroxyalkyl cyclic carbonates can be prepared by a number of approximations. Certain hydroxyalkyl cyclic carbonates such as 3-hydroxypropyl carbonate (ie, glycerin carbonate) are commercially available. The cyclic carbonate compounds can be synthesized by any of the different approaches. One approach involves the reaction of a compound containing a group of epoxy with CO2, under conditions and with catalysts as described hereinbefore. The epoxies can also be reacted with the β-butyrolactone in the presence of one of these catalysts. In another approach, a glycol such as glycerin is reacted at temperatures of at least 80 ° C with diethyl carbonate in the presence of a catalyst (eg, potassium carbonate) to form a hydroxyalkyl carbonate. Alternatively, a functional compound containing a ketal of a diol-1,2 having a structure: 0 0 R it may be ring breaking with water, preferably with a minimum amount of acid, to form a glyco-1,2, which is then also reacted with the dethyl carbonate to form the cyclic carbonate.

Cyclic carbonates typically have rings that have members 5-6-, as is known in the art. The 5-membered ring is preferred, due to its ease of synthesis and greater degree of commercial availability. The 6-membered rings can be synthesized by the reaction of phosgene with 1,3-propane diol under conditions known in the art for the formation of cyclic carbonates. Preferred cyclic hydroxyalkyl carbonates used in practice can be represented in the formula: ÍS wherein R (1 each example of R if n is more than 1) is a hydroxyalkyl group of 1-18 carbon atoms, preferably 1-6 carbon atoms and more preferably 1-3 carbon atoms, which they can be linear or branched and they can have substituents in addition to the hydroxyl (which by itself can be primary, secondary or tertiary), and n is 1 or 2, which can be replaced by one or more substituents such as blocked amines or non-hydroxy groups. saturated. More preferably, R is -CmH2mOH wherein the hydroxyl can be primary or secondary and m is from 1 to 8, and even more preferably, R is - (CH2) p-OH wherein the hydroxyl is primary and p is from 1 to 2 .

Lactones that can be ring broken by an active hydrogen are well known in the art. These include, for example, e-caprolactone, α-caprolactone, β-butyrolactone, β-propriolactone, β-butyrolactone, -methyl-β-butyrolactone, β-n-ethyl-y-butyrolactone, β-valerolactone, d-valerolactone ? -nonaic lactone,? -octanoic lactone, and pentolactone. In a preferred embodiment, the lactone is e-caprolactone. Lactones useful in the practice of the invention are also characterized by the formula: wherein n is a positive integer from 1 to 7 and R is one plus H atoms, or substituted or unsubstituted alkyl groups of a-7 carbon atoms.

The ring-breaking reaction of the lactone is typically conducted under elevated temperatures (eg, 80-150 ° C). The reactants are generally liquid so that a solvent is not necessary. However, a solvent can be useful to promote good conditions for the reaction, even if the reagents are liquid. Any non-reactive solvent can be used, including both polar and non-polar organic solvents. Examples of useful solvents include toluene, xylene, methyl, ethyl, ketone, methyl isobutyl ketone, and the like. Preferably a catalyst is present. Useful catalysts include proton acids (e.g., okatanoic acid, Amnberlyst® 15 (Rohm &Haas)), and tin catalysts (e.g., tin octoate). Alternatively, the reaction can be initiated by forming a sodium salt of the hydroxyl group on the molecules to react with the cation ring.

The ring-breaking reaction of the lactone provides a chain extension of the molecule if sufficient quantities of lactone are present. The relative amounts of the carbomate compound (a) (i) and the lactone (a) (ii) can be varied to control the degree of chain extension. Breaking the lactone ring with a hydroxyl or amine group results in the formation of an ester or amide or an OH group. The OH group can then react with available ring bull of lactone, thus resulting in chain extension. The reaction is countered in this way by the ratio of the lactone in relation to the amount of the initiator compound (a) (i).

A compound (a) (i) having a hydroxyl active hydrogen group can also be reacted with a hydroxyl carboxylic acid including dimethylhydroxypropionic acid, hydroxy stearic acid, tartaric acid, lactic acid, benzoic acid of 2-hydroxyethyl and triametico acid of diamine ethyl (-2-hydroxyethyl). The reaction may be conducted under typical transesterification conditions, for example, temperatures from ambient temperature to 150 ° C with transesterification catalysts such as calcium octoate, metal hydrocides (eg KOH), Group I or II metals (e.g., Na, Li), metal carbonates (e.g., H2C03) that can be improved by being used in combination with crown ethers, metal oxides (e.g., dibutyltin oxide), metal alkosides (e.g. Ba0CH3, AL (0C3H7) 3), metal esters (eg, tin octoate, calcium octoate or protic acids (eg H2S04), MgC03, or Ph4SbI.The reaction can also be conducted at room temperature with a catalyst supported by polymer such as Ambertlist-15® (Rohm &Hass) as described by R. Anand, Synthetic Communications, 24 (19), 2743-47 (1994), the information of which is incorporated herein by reference.

In a preferred embodiment of formula (ii), the oligomeric or polymer component is formed by reacting the component as described in the preferred embodiment for formula (I) with a diisocyanate or polyisocyanate. In this way, this modality can be described as a nucleus to which a plurality of functional carbamate residues of the preferred embodiment of formula (I) are added.

A preferred embodiment of Formula III is obtained by mixing the preferred embodiment of formula (I) with other compounds comprising at least one hydroxyl group plus a carbamate group (e.g., hydroxypropyl carbazoate) prior to the reaction with the diol. polyisocyanate In a case such as this, the resulting product mixture of the reaction will reflect the stoichiometric ratio of the components according to the preferred embodiment of Formula (I) for the other compounds.

The polyisocyanate can be an aliphatic polyisocyanate, including a cycloaliphatic polyisocyanate or an aromatic polyisocyanate. Useful aliphatic polyisocyanates include ethylene diisocyanate, 1/2-diisocyanatopropane, 1,3-diisocyanatopropane, 1/6-diisocyanatohexane, 1,4-diisocyanate of butylene, diisocyanatohexane of lysine, 1,4-methyl ene- (isocyanate of cyclohexyl) and isophorone diisocyanate Useful aromatic diisocyanates and araliphatic diisocyanates include various isomers of toluene diisocyanate, meta-xylylenediisocyanate and para-xylylenediisocyanate, also 4-chloro-1,3-phenylene diisocyanate, 1,5-diisocyanate Naphthalene-tetrahydro, 4,4'-dibenxyl diisocyanate and 1,2-benzene triisocyanate can be used .. In addition, the various isomers of,, a ', a'-tetramethylene xylene diisocyanate can be used. Polymeric or oligomeric agents with polyol can be used, and isocyanurates such as isocyanurate of isophorone diisocyanate or isocyanurate of hexamethylene diisocyanate can also be used. biurets of isocyanates such as DESMODUR® NI00 from Mobay.

The composition of the invention is cured by a reaction of the polymeric or oligomeric component (A) with a component (B) which is a compound having a plurality of functional groups that are reactive with the reactive functionality on the component (A). The reactive groups on (B) include the methylol or metyalalkoxy groups on crosslinking agents or on other compounds such as the phenol / formalhehido adducts, isocyanate groups, siloxane groups, cyclic carbonate groups, and anhydride groups. Examples of the compounds (B) include melamine formaldehyde resin (including monomeric and polymeric melamine resin and partially or completely of alkylated melamine resin), urea resins (for example, methylol ureas such as the formaldehyde resin of urea, alkoxy ureas such as butylated urea formaldehyde resin), polyanhydrides (e.g., polysixin anhydride), and polysiloxanes (e.g., trimethoxy siloxane). Aminoplast resin such as melamine formaldheide resin or urea formaldheide resin are especially preferred. Also preferred are aminoplast resin wherein one or more amino nitrogens are substituted with a carbamate group to be used in a process with a curing temperature of less than 150 ° C, as described in U.S. Patent 5,300,328. .

Alternatively, component (B) can be a polymeric isocyanate wherein component (A) comprises isocyanate-reactive functional groups. Polymeric isocyanates suitable as component (B) are known in the art and include polymers of the following isocyanates: hexamethylene diisocyanate, sodorone diisocyanate, 4,4'-biphenylene diisocyanate, toluene diisocyanate, bis-cyclohexyl diisocyanate, diisocyanate xylene tetramethylene, ethyl ethylene diisocyanate, 2,3-dimethyl ethylene diisocyanate, 1-methyltrimethylene diisocyanate, 1,3-cyclopentylene di-isocyanate, 1,4-cyclohexylene diisocyanate, 1,3-penylene diisocyanate, 1, 5-naptylene diisocyanate, methane bis- (4-isocyanatocyolhexyl) and the like. The polymers refer to the isocyanurates, biurets, allophanates and polyol adducts of the isocyanates named above.

Depending on the functionality of the component (A), the functional crosslinking agents of epoxy, acids and anhydrides can also be used in the coating compositions of the present invention.

The coating composition according to the invention can be applied without solvent. However, in many cases it is also desirable to use a solvent in the coating composition. This solvent should act as a solvent with respect to both oligomeric or polymeric components (A), as well as component (B). In general, depending on the solubility characteristics of the components (A) and (B), the solvent can be any organic solvent and / or water. In a preferred embodiment, the solvent is a polar organic solvent. More preferably, the solvent is a polar aliphatic solvent or a polar aromatic solvent. Even more preferred, the solvent is a ketone, ester, acetate, aprotic amide. aprotic sulfoxide or aprotic amine. Examples of the useful solvents include methyl ethyl ketone, methyl isobuityl ketone, amyl acetate, ethylene glycol butyl ether acetate, propylene glycol monomethyl ether acetate, silene, N-methylpyrrolidone or mixtures thereof. the aromatic hydrocarbons. In another embodiment, the solvent may be water or a mixture of water with co-solvents.

The coating composition that is used in the practice of the invention may include a catalyst to improve the cure reaction. For example, when aminoplast compounds, especially monomeric melamines are used as component (B), a strong acid catalyst can be used to improve the cure reaction. These catalysts are well known in the art and include, for example, p-toluenesulfonic acid, dinonylnaphthalene disulfonic acid, dodecylbenzenesulfonic acid, phenyl phosphate, monobutyl group, butyl phosphate and hydroxy phosphate ester. Other catalysts that may be useful in the composition of the invention include Lewis acids, zinc salts and tin salts.

The coating compositions can be coated on an article by any of the techniques well known in the art. These include, for example, spray coating, chemical bath coating, cylinder coating, curtain coating and the like. For the automotive components, the spray coating is preferred. One advantage that can be achieved with the coating compositions according to the invention, is that coatings with a high degree of flexibility can be prepared. Accordingly, in a preferred embodiment the substrate on which the coating is applied is flexible, such as plastic, rubber or textile substrates.

Any additional agent that is used, for example, surfactants, fillers, stabilizers, moisture agents, dispersing agents, adhesion promoters, UV absorbers, HALS, etc. they can be incorporated into the coating composition. While the agents are well known in the prior art, the amount used must be controlled to avoid adverse effects to the coating characteristics.

In a preferred embodiment, the coating composition according to the invention is preferably used in a high gloss coating and / or as the transparent layer of a more transparent colored coating composition. The high gloss coatings as used herein are coatings having a 20 ° gloss (ASTM D523-89) or a DOI (ASTM E430-91) of at least 80. In other preferred embodiments, the coating composition is You can use it to prepare a high gloss, a first low gloss or enamel coatings.

When the composition of the coating of the invention is used as a high gloss pigmented paint coating, the pigment may be any organic or inorganic compound or colored, filled, metallic or other inorganic flake materials such as mica or flakes or lamellae of aluminum, and other materials of the type that are normally called corao pigments within the technique. The pigments are generally used in the composition in an amount of 2% to 350%, based on the total weight (not including the solvent) of components and B (ie, a P: B ratio of 0.02 to 3.5).

When the coating composition according to the invention is used as the transparent cover of a more transparent colored composite coating, the pigmented composition of the base layer can be any of a number of types well known in the art and does not require explanation in detail in the present. Polymers known in the art to be useful in basecoat compositions include acrylics, vinyls, polyurethanes, polycarbonates, polyesters, alkyls and siloxanes. Preferred polymers include acrylics and polyurethanes. In a preferred embodiment of the invention, the basecoat composition also utilizes a functional acrylic carbamate polymer. The basecoat polymers are preferably crosslinked and thus comprise one or more types of crosslinking functional groups. These groups include, for example, hydroxy, isoacyanate, amine, epoxy, acrylate, vinyl, silane and acetotacetate groups. These groups can be masked or blocked in such a way that they are not blocked and available for the crosslinking reaction under the desired curing conditions, generally at elevated temperatures Useful crosslinkable functional groups include hydroxy, apoxia, acid, anhydride, silane and acetoacetate groups The preferred crosslinkable functional groups include hydroxy functional groups and amino functional groups.

The polymers of the base layer can be self-crosslinkable or may require a separate crosslinking agent that is reactive with the functional groups of the polymer. When the polymer comprises hydroxy functional groups, for example, the crosslinking agent may be an aminoplast resin, isocyanates and blocked isocyanates (including isocyanurates), and anhydride functional crosslinking acid or agents.

The coating compositions described herein are preferably subjected to conditions such as to cure the coating layers. Although various curing methods can be used, thermal curing is preferred. Generally the thermal curing is affected by the exposure of the coated article at high temperatures provided primarily by radioactive thermal sources. The curing temperatures will vary depending on the particular crosslinking agents, however, they are generally between the range of 93 ° C and 177 ° C. The coating composition according to the present invention is curable even at relatively low cure temperatures. Thus, in a preferred embodiment, the cure temperature is preferably between 115 ° C and 150 ° C, and more preferably at temperatures between 115 ° C and 138 ° C for a blocked acid catalyzed system. For a catalyzed system of an unblocked acid, the cure temperature is preferably between 82 ° C and 99 ° C. The curing time will vary depending on the particular components that are used, and the physical parameters such as the thickness of the layers; however, the typical curing time is in the range of 15 to 60 minutes, preferably 15-25 minutes for the blocked acid catalyzed systems and 10-20 minutes for the catalyzed systems of unblocked acid.

The invention will be further described in the following examples which are not limiting.

Composition No. 1 The e-caprolactone, hydroxy propyl carbomate and toluene are added to a round-bottomed glass flask equipped with a stirrer, thermometer and an inlet for the inert gas. After mixing thoroughly under an inert atmosphere, the tin octoate is added. The mixture was heated to 130 ° C and maintained at that temperature for a period of 4.5 hours, after cooling to room temperature.

Material Weight (gr) e-caprolactone 5715 Hydroxy propyl carbamate 2385 Toluene 886 Tin octoate 14 Composition No. 2 Isforone diisocyanate was added to the round-bottomed glass flask equipped with a stirrer, thermometer and inlet for the inert gauze. Composition No. 1 was added by mixing under an inert atmosphere for a period of more than one hour with sufficient heating to promote the exothermic reaction. At the initiation of the exotherm, cooling was applied so that the temperature leapt to 67 ° C. The mixture was heated and maintained at a temperature of 80 ° C until all the isocyanate was consumed. The mixture was reduced with propylene glycol methyl ether acetate and cooled to room temperature.

Material Weight (gr) Isoforone diisocyanate 1222 Composition No. 1 4989 Propylene glycol 4989 methyl ether acetate Composition No. 3 Isocyanate of isophorone diisocyanate and propylene glycol methyl ether acetate were added to the round-bottomed glass flask equipped with a stirrer, thermometer and inert gas inlet. The heating was applied under conditions of inert atmosphere at a temperature of 46 ° C and until the isocyanurate was completely dissolved by the methyl ether acetate of propylene glycol. The n-butanol and composition No. 1 were added over a period of more than 40 minutes. The mixture was allowed to exotherm until a temperature of 80 ° C was reached. This temperature was maintained until the reaction of n-butanol and composition No.l came to an end. The additional n-butanol was added and the mixture was maintained at 80 ° C until the isocyanate groups were consumed. The mixture was then reduced with propylene glycol methyl ether acetate and then cooled to room temperature.

Material Weight (gr) Isocyanurate of 2068 Isoforone diisocyanate (100% N.V.) * Glycol methyl ether acetate 1340 propylene Composition No. 1 3228 n-butanol 62 n-butanol 56 Glycol methyl ether acetate 378 propylene * Available at Huís America Example 1 A clear coat was prepared by mixing the following ingredients together: Ingredients Weight in Grams Composition No. 3 1250.5 Resimene® 747 to 143.4 NACURE® XP-2 3B 30.8 TINUVIN® 1130C 30.6 TINUVIN® 123D 6.2 BUK® 32OE 1.9 Lindron® 22f 3.5 Butyl ether acetate of 640.9 ethylene glycol n-butanol 319.9 T or t 2427. 6 This mixture was reduced with n-butyl acetate to a viscous application of 31 seconds on a Ford No.4 cup. a Resimine® 747 is a fully methylated melamine sold by Monsanto. b Nacure® XP-243 is a blocked acid catalyst available from King Industries c Tinuvin® 1130 is an ultraviolet absorber available in Ciba Geigy d Tinuvin® 123 is a light stabilizer of clogged amine available from Ciba Geigy. e Byk® 320 is a surface modified agent available from Byk Industries. f Lindron® 22 is a surface modifying agent available from Lindau Chemicals.

Example 2 A clear layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams Composition No. 3 324.4 Resimene® 747 37.9 NACURE® XP-2 3 8.0 TINUVIN® 1130 8.2 TINUVIN® 123 1.9 BUK® 306a 2.3 Butyl ether acetate of 79.9 ethylene glycol n-butanol 39. 7 T or t a l 502. 3 a Byk® 306 is a modified surface agent available from BYK Industries.

Example 3 A clear layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams Composition No. 3 290.6 Resi ene® 747 67.8 NACURE® XP-243 8.2 TINUVIN® 1130 8.2 TINUVIN® 123 1.7 BUK® 306 2.3 Butyl ether acetate-81.4 ethylene glycol n-butanol 40.7 T or t a l 501. 2 This mixture was reduced with n-butyl acetate to a viscous application of 90 cP.

Example 4 • A transparent layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams Composition No. 1 286.4 Resimene® 747 147.4 NACURE® XP-243 11.7 TINUVIN® 1130 11.6 TINUVIN® 123 2.2 BUK® 306 3.3 A butyl ether acetate 7.8 ethylene glycol n-butanol 7. 8 T or t a l 478. , This mixture was reduced with n-butyl acetate to a viscous application of 165 cP.

Example 5 A clear layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams Composition No. 1 107.7 Composition No. 2 117.1 Resimene® 747 151.6 NACURE® XP-243 10.0 TINUVIN® 1130 10.1 TINUVIN® 123 2.0 BUK® 306 3.0 Butyl ether acetate of 49.9 ethylene glycol n-butanol '50. 3 T or t a l 501.7 This mixture was reduced with n-butyl acetate to a viscous application of 139 cP.

Example 6 A clear layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams TONE® 310a 262.9 Resimene® 747 101.8 NACURE® XP-243 10.9 TINUVIN® 1130 10.9 TINUVIN® 123 2.1 BUK® 306 3.1 Butyl ether acetate of 29.6 ethylene glycol n-butanol 29.3 T or t a l 450.6 This mixture was reduced with n-butyl acetate to a viscous application of 166 cP. a Tone® 310 is a polyol based on e-caprolactone available from Union Carbide.

Example 7 A clear layer was prepared by mixing together the following ingredients: Ingredients ^ Weight in Grams TONE® 310a 205.6 Resimene® 747 159.2 NACURE® XP-243 11.0 TI UVIM® 1130 11.4 TINUVIN® 123 2.4 BUK® 306 2.9 Butyl ether acetate of 35.7 ethylene glycol n-butanol 29.9 T o t l 458.1 This mixture was reduced with n-butyl acetate to a viscous application of 183 cP.

Example 8 A clear layer was prepared by mixing together the following ingredients: Ingredients Weight in Grams Component -A TONE® 310a 273.2 TINUVIN® 1130 14.2 TINUVIN® 123 2.9 BUK® 306 3.9 Butyl ether acetate of 51.2 ethylene glycol Component -B: Desmodur® N3390a 136.9 Desmodur® Z4370 / 2b 117.3 T or t a l 652.8 The mixture of component-A was reduced with n-butyl acetate to a viscous application of 126 cP. Component-A and Component-B were mixed together just prior to the application.

Desmodur® 'N3390a is the isocyanurate of hexamethylene diisocyanate.

Desmodur® Z4370 / 2b is the isocyanurate of isophorone diisocyanate.

Example 9 A flexible transparent layer of the commercial component-1 which is commercially available from BASF Corporation and is identified as E86CM200. This clear coat is based on a functional acrylic hydroxyl polymer that is crosslinked with a methylated melamine crosslinker sold under the trademark of Resimene® 747.

This clear coat, E86CM200, was reduced with n-butyl acetate to a viscous 24-second application of Ford No.4.

Example 10 A flexible transparent layer of the commercial component-2 which is commercially available from BASF Corporation. The -A component is identified as E42CM024 and the component -B is identified as N52CM045. This transparent layer is based on a functional hydroxyl acrylic polymer that is crosslinked with a mixture of isocyanates.

This transparent layer E42CM024, was reduced with n-butyl acetate until a viscous application of 24 seconds of Ford No.4.

The clear coat compositions of Examples 1-10 were spray applied to a white pigmented base coat to form a more transparent colored coating on a Thermoplastic Polyolefin (TPO) substrate, Dexter Dexflex D-161B, which was prepared with an adhesion promoter. The white pigmented base layer that was used in Examples 1-10 is commercially available from BASF Corporation and identified as R86WE466. The adhesion promoter that was used in Examples 1-10 is commercially available from Morton and identified as Morton HP210544G1.

The adhesion promoter was applied by spraying in one layer to the TPO plates at a temperature of about 2 ° C. An instant time of 5 minutes was allowed at a temperature of approximately 24 ° C before the application of the base coat. The base layer was applied by spraying in two layers to the plates promoted by adhesion at a temperature of approximately 24 ° C. An instant time of 30 seconds was allowed between the two applications of the base layer.

After the second application of the base coat, an instant time of about 5 minutes was allowed before the application of the clear coat compositions. The clearcoat compositions of Examples 1-10 were each applied by spraying to the plates of the coated base in two layers with an instant of 60 seconds between each layer at a temperature of about 24 ° C. The clear layer was flashed at room temperature for 10 minutes and then baked for 30 minutes at 121 ° C. The plates were baked in a horizontal position in a conventional gas oven.

Test of Coating Compositions.

The coating compositions described above were tested to impact the abrasion resistance in accordance with the following test method.

The Sledge Test is a method for evaluating impact-induced paint damage according to the development of D &S Plastics International of Auburn Hills, Michigan. This test method is similar to many of the pendulum impact tests, such as the Izod, Konig and Persoz Pendulum Hardness Tests. This test involves the impact of the brightness of a rough 15-pound sled on a coated substrate.

The test apparatus is shown in Figure 1 and comprises an open structure connected by a crossbar. A pendulum arm with a 15-pound semicircle "sled" is attached to the crossbar. The length of the pendulum arm is 59.1 cm. (23.21 inches) from the center of the revolution to the point of the weight of the "sled". The distance from the center of the revolution to the point of the holder of the test sample is 59.2 cm. (23.31 inches). This gives an impact depth at 0o of 0.043 inches) with a 0.32 cm standard thickness test plate.

The test sample is first cleaned with isopropyl alcohol and conditioned for 1 hour at a temperature of 165 ° F. During this time the weight of the "sled" is also cleaned with isopropyl alcohol. When the sample is ready for testing, the pendulum arm is lifted 90 ° from the test sample holder and closed in place with a release mechanism. The sample of the test is removed from the oven and placed immediately in the sample holder. The release mechanism is then released and the pendulum arm arches downward and the weight of the "sled" makes contact with the test sample with a brightness impact. The weight of the "sled" is then raised again to a position prepared at 90 ° towards the holder of the test sample and the test sample is stopped. Using a transparent superimposed layer with a 5 mm X 5 mm grid, the area of paint removed in mm2 is reported. The larger the number the more was the damage incurred in the sample.

The results of the clear coat compositions of Examples 1-10 are reported in Table I.

TABLE T Table of Comparative Results for Transparent Layer Compositions Coating Weight Functionality Sled Equivalent Average Area removed ip? N2 Example 1 705 3.1 0 Example 2 705 3.1 0 Example 3 705 3.1 0 Example 4 202 2 Cont. Coating Weight Functionality Sledge Equivalent Average Area removed mm2 Example 5 286 2 0 Example 6 299 3 < 1 Example 7 299 3 0 Example 8 299 3 0 Example 9 565 6.1 115 Commercial Control Ikg Example 10 407 7.7 137 Commercial Control 2. Kg

Claims (24)

1. A curable coating composition resistant to damage induced by impact abrasion comprising:

A) a sligomeric or polymeric component comprising aliphatic ester or other aliphatic ether groups having on it a plurality of reactive functionalities and having a reactive functionality between 2 and 5 and an equivalent weight of between 150 and 750, and

B) a compound comprising a plurality of groups that are reactive with reactive functionality on component (A).

2. The curable coating composition of claim 1, wherein the compound (A) is selected from the group consisting of:

I) X-L-X 'wherein X and X' may be the same or different and represent the degradable functionality selected from the group consisting of hydroxyl, amino, primary carbamate, isocyanate, epoxy, carboxyl and mixtures thereof, and

L represents a segment comprising one or more units selected from the group consisting of aliphatic ester groups, aliphatic esters derived from lactones, aliphatic ester groups and mixtures thereof;

II Z- (Ln -Y) n where Z represents a linking group selected from the group consisting of diols, polyols, diisocyanates and polyisocyanates,

Y represents a degradable functionality selected from the group consisting of hydroxyl, amine, primary carbamate, isocyanate, epoxy, carboxyl and mixtures thereof, and Ln represents one or more units selected from the group consisting of aliphatic ester groups , esters derived from lactones, aliphatic ether groups and mixtures thereof, wherein each Ln may be the same or different,

And n is the functionality of the polymer or oligomer (A) and is number between 2 and 5,;

III) Z- (Ln-x -Y) n-x Yx

wherein Z represents a linking group selected from the group consisting of diols, polyols diisocyanates and polyisocyanates, Y represents a degradable functionality selected from the group consisting of hydroxyl, amine, primary carbamate, isocyanate, epoxy, carboxyl and mixtures of the same, and L represents one or more units selected from the group consisting of aliphatic ester groups, esters derived from lactones, aliphatic ether groups and mixtures thereof, wherein each Ln may be the same or different, and is the functionality of the polymer or oligomer (A) and is number between 2 and 5, and x is the number of functional end groups that do not contain a chain extension segment and is a number between 0 and n, and mixtures of (I) , (II) and (III).

3. The coating composition of claim 2, wherein n is a number between 2.0 and 3.6

4. A composition of the coating according to claim 2, wherein in the formula (I) X and X 'are selected from the group consisting of hydroxyl and primary carbamate.

5. A composition of the coating according to claim 2, wherein in the formula (II) Y is hydroxyl, L is a polyester derived from e-caprolactone and Z is a polio.

6. A composition of the coating according to claim 2, wherein the Z is selected from the group consisting of 1,6-hexane, trimethylolpropane, diethylene glycol, pentaerythritol and diol or substituted carbamate polyol.

7. A coating composition according to claim 2, wherein in Formula (III) z represents a diol or polyol with a carbamate-or pendant group.

. claim 2, wherein in Formula (III) Y is a primary carbamate and Z is a polyisocyanate and x is between n and 0.

9. A coating composition according to claim 1 or 2, wherein the reactive groups on the component (B) are selected from the group consisting of active methylol and methylalkoxy groups on the aminoplast crosslinking agents, active methylol and groups of methylalkoxy on phenol / dormaldehyde adducts, isocyanate groups, solxane groups, cyclic carbonate groups and anhydride groups.

10. A coating composition according to claim 1 or 2, wherein component B is selected from the group consisting of melamine formaldehyde resin, urea resins, polyisocyanates, polyanhydrides and polysiloxanes.

11. A coating composition according to claim 1 or 2, wherein the component (B) is selected from the group consisting of monomeric melamine, polymeric melamine resin, partially alkylated and fully alkylated melamine resins.

12. A coating composition according to claim 1 or 2, wherein the component (B) is selected from the group consisting of polyisocyanate resins.

13. A coating composition according to claim 2, wherein the oligomeric or polymer component (A) comprises

(a) a compound comprising carbamate and hydroxyl functional groups which is the reaction of the product of

(i) a compound comprising a carbamate group or a group that can be converted into a carbamate or group, and an active hydrogen group that is reactive with a lactone or hydroxy carboxylic acid, and (ii) a lactone or a carboxylic acid of hydroxy.

14. A coating composition according to claim 13, wherein the active hydrogen group on (a) (i) is selected from the group consisting of hydroxyl and amino groups.

15. A composition of the coating according to claim 13, wherein the component (a) further comprises: (iii) a compound that is reactive with the hydroxyl groups on a plurality of molecules of the compound (a) (i), but which it is not reactive with the carbamate groups on the compound (a) (i).

16. A coating composition according to claim 15, wherein the component (a) (iii) comprises isocyanate.

17. A coating composition according to claim 13 or 15, wherein the compound (a) comprises carbamate and hydroxyl functional groups.

18. A coating composition according to claim 13 or 15, wherein the compound (a) (ii) is a lactone.

19. A composition of the coating according to claim 2, wherein the component (A) is a mixture of the compounds selected from the group consisting of (I), (II) and (III).

20. A composition of the coating according to claim 1 or 2, further comprising a compound selected from the group consisting of polymer acrylic and polyester and resins.

21. A coating composition according to claim 1 which is a clear coating composition.

22. A composition of the coating according to claim 1, which also comprises a pigment.

23. An article comprising a substrate having thereon a cured coating derived from a coating composition in accordance with both claim 1 and claim 2.

24. An article according to claim 23, wherein the substrate is a flexible substrate.