MXPA97009987A

MXPA97009987A - Polyurethane polyols and coatings of the same that have viscosity relat

Info

Publication number: MXPA97009987A
Application number: MXPA/A/1997/009987A
Authority: MX
Inventors: Leo Yahkind Alexander; Wagstaff Ian; Herbert Walker Frederick
Original assignee: Akzo Nobel Nv
Priority date: 1995-06-07
Filing date: 1997-12-08
Publication date: 1998-10-15

Abstract

The present invention relates to a film-forming composition, a method for forming the composition and application of the composition to coating formulations that provide a cured coating having rain-acid resistance, a polyurethane-polyol-film-forming composition comprises a reaction product of an n-functional isocyanate (wherein n is a number ranging from about 2 to about 5) with at least one diol or triol or mixtures thereof, and a compound containing reactive isocyanate functional groups , preferably a monofunctional alcohol or thiol, the low viscosity polyurethane polyol of the present invention is typically entangled / cured using a melamine to produce a cured coating which is highly resistant to corrosion acid and which also has other suitable physical and mechanical properties; the coating compositions have better flow characteristics Adas comparatively with compositions containing polyurethane polyols prepared without the alcohols or thiols monofunctional

Description

POLYURETHANE POLYCLES AND COATINGS OF THE SAME THAT HAVE REDUCED VISCOSITY BACKGROUND OF THE INVENTION 1. - FIELD OF THE INVENTION The present invention refers to the use of a particular class of polynomials. for forming a t-bond or with an air content of solids having a reduced viscosity at i as resistance to environmental factors, as well as acidity, and light as a result of radicle-t. The polyurethane polyols are prepared by reacting a polyisocyanate or as a compound having a unique functional group reactive with the soclanate, such as a non-functional alcohol or a thiol. mono fune i ona L, as with a diol or triol that reacts sub- sistically only at a single end with a partner-t o. 2. BACKGROUND OF THE INVENTION Many of the high-performance, high-performance, high-performance automotive applications currently in use have been developed in polymer systems that contain polyester + or acrylic polyols. ., (? n the single-component reversals, in which all the ingredients are from the reverse or combine in a stable storage mixture, the polyester or acrylic polyol component. it is typically entangled with inelamin (ammoplastic ream) under heat cure conditions of approximately 121.1 ° C or more to provide a thermally cured coating.In typical two-component systems, such polyols are combined with a suitable isocyanate shortly before the application to The surface to be coated and the combination is cured at temperatures ranging from approximately 21.L ° C to approximately 13 ° 7.7 ° C. Currently, the automotive industry is using coatings of base coat and clear coat in quantities each more time I grew up In such systems, a pigmented coating is applied over appropriate primers and the coating system is completed by applying a clear, non-pigmented top coat over the pigmented base coat. It is also desirable that such coating systems comply with the VOC regulation, which typically requires that the transparent layer has solids in volume of more than 50% (for a high solids content type). Simultaneously, due to the deterioration of our environment, the automotive industry has been looking for coating systems which, after being cured / dried, are resistant to acid rain. To obtain high solids contents while maintaining an acceptable viscosity of the coating formulation for spray application, the industry has tended to reduce the number-average molecular weight (Mn) of the film forming the polymers and increase the amount of interleaver, thereby obtaining a cured coating having hardness, gloss, impact resistance, appearance and adequate exterior durability. Typical coating formulations use a melamine or other non-plastics resin as an interlacer. The increased amounts of melamine ring crosslinkers reduce the viscosity of the formulation. As the amount of resin is increased, the resistance to acid rain of these coatings is compromised. At present, automotive manufacturers consider that the improved resistance of automotive finishing coatings to environmental corrosion (acid rain) is a high priority. It is believed that the ester bonds in an acrylic rnelarnin coating or the polyester amine mel amine are weak spots in the entangled resin network, susceptible to catalyzed hydrolysis or acid. The current automotive topcoats with only solid content, either monolayers or the most modern base / clearcoats, are predominantly olymetric acrylic polyols intertwined with rnelarnine / formaldehyde resins. Modern upper layers of this type form visually appealing films, high gloss and are designed to retain high gloss levels after extensive accelerated exposure to the environment and Florida exposure. In recent years, additional improvement in durability has been obtained by the use of basecoat / clearcoat systems, in which the clearcoat acts as a screen to protect the pigmented film. There has been a general reduction in pH and an increase in the concentration of electrolytes, in rainwater, creating "acid rain". Probably as a result of the combination of these factors, a new problem has arisen in the upper layer technology, which is generally referred to as acid or environmental corrosion. The defect looks like a pattern of grainy water spots seen predominantly on horizontal surfaces. An in-depth study of the problem of General Motors workers indicates that acid components in a case of wetting (dew or rain) react with calcium, a common constituent of dirt. As the small droplets evaporate, a calcium sulfate precipitate forms on the horizontal surfaces around the perimeters of the small droplets. In subsequent washing, the precipitate is removed, but the marks remain. It is generally observed that the problem is more noticeable on dark surfaces, freshly painted in more warm and polluted environmental media. Normal entanglement on the surface of a coating induced by exposure to ultraviolet wording and oxygen can ultimately protect the film. In this way, the problem is largely one that occurs in the parking lots of the automotive distributors. Frequently, corroded cars must be repainted before they can be sold. A leading manufacturer of E.U.A. estimates that the cost of environmental corrosion exceeds 50 million dollars per year. A considerable amount of work has been done related to the coatings containing polyurethane polyols. One way of making polyurethane polyols is to react a functional isocyanate or isocyanate with a significant excess of a diol. After the reaction is complete, the excess diol is removed, preferably by distillation.The obvious disadvantage of this method of making low molecular weight polyurethane polyols is that distillation of the diols is inconvenient and it is not possible to use diols of high molecular weight (which can not be separated by distillation) at a later time, and the molecular weight control is difficult in such procedures because even in the excess of the sticiometer, a limited number of hydroxyl groups on the same The molecules of the diols will react with the isocyanate, giving chain extensions beyond the desired low molecular weight polymers.This results in broad molecular weight distributions.The US patents that describe the production of polyurethane polyols using esti-bio-electrical excess of diols include: US Pat. No. 4,543,405 to ñrnbrose, and others; published on September 24, 1985; and the U.S. Patent. 4,288,577 to McShane, Jr., published September 8, 1981.

Interlaced coatings based on polyurethane polyols of this type have been described in U.S. Patents. A 548, 998 to Chang, and others; published on October 22, 1985; 4,540,766 to Chang, et al., Published September 10, L985; and 4,485,228 to Chang, et al., published November 27, 1984. The coatings or base of these compositions offer good balance of flexibility and hardness. Another class of similar polypnecop coating systems are based on modified urethane polyesters. Polymeric systems are prepared by reacting a polusocyanate with an excess of diol and only then this mixture results in a polyol reagent to carry out the conventional condensation of polyester including acids, diols, triols, etc. Alternatively, conventional hydroxyl-terminated polyesters can be extended with isocyanates. The typical patents of E.U.ñ. which describe such polymeric systems include: U.S. Patent. 4,605, i? 24 a ñrnbrose, and others, published on August 12, 1986; the Patent of E.U.A. 4,540,771 to ftrnbrose et al., Published September 10, 1985; the Patent of E.U.fi. 4,530,976 to Kordornenos et al., Published July 23, 1985; the Patent of E.U.fi. 4. 533.703 to Kordo enos et al., Published on 6th June 1985; the Patent of E.U.ñ. 4,524,192 to filexander et al., Published June 18, 1985; and the Patent of E.U.fi. 4. 533.704 to filexander et al., Published on 6th of 1985. These patents describe methods for producing polymers and their use in coatings. Japanese Patent 82-3P-115024, assigned to ASAHT Chemical IND KK, describes a method for preparing an isocyanate-terminated prepolymer in which the isocyanate termination groups have different reactivity. The polyisocyanate-terminated prepolymer is prepared by reacting two types of polusocyanate that have different reactivities with the diols having two kinds of hydroxyl group in the different reactivity. In the subsequent preparation, a subsequent cure is carried out using moisture or another source of hydroxyl groups. The Patent of F.U.fi. No. 3,576.77? describes the use of polyurethanes prepared from organic isocyanates and glycols together with unsaturated alkyd resins modified with oil to prepare txotropic paints. Small quantities of monocyanates and monoalcohols may be used concurrently with these reagents. Since it has been described that polyurethanes retain their thixotropic properties, it is believed that they have relatively large molecular weight distributions. European Patent EP 0 001 304 of fi x N.V. discloses coating compositions containing physical mixtures in organic solvents of polyhydroxy compounds, and polyisocyanates in tertiary alcohols having a long life in crucible but quick cure when applied.

The Patent of E.U.fi. No. 2,873,266 discloses polyurethane which is prepared by reacting the mixture of primary and secondary glycols, each containing at least 4 carbon atoms between the hydroxyl groups with an aliphatic diiso compound containing two groups of the formula -N = C = X separated by at least 4 carbon atoms, where X is oxygen or sulfur. The Patent of E.U.ñ. No. 4,619,955 discloses isocyanate functional urethanes, useful as flexibilizing additives for polypnepic vehicles, including the reaction products of a) aliphatic polusocyanates, b) at least one non-functional alcohol containing an ether or carboxy-oxygen and c) at least a diol The Patent of E.U.fi. No. 4,631,320 discloses thermosetting coating compositions including polyurethanes containing hydroxy groups, arnine linkers and catalysts and / or optional solvents. The hydroxyurethane hydrates can be prepared either by self-condensing certain polyhydroxyalkyl carbonate compounds or by condensing them with polyols. The Patent of E.U.ñ. No. 5,155,201 from Akzo N.V. discloses polyurethane polyols containing reaction products of n-functional polusocyanates (n = 2-5) and substantially inonorne diols having hydroxyl groups separated by 3 carbon atoms or metals, and is incorporated herein by reference.

The Patent of E.U.ñ. No. 5,175.22? of flkzo N.V. discloses acid corrosion resistant coating compositions which include crosslinker polylactane polyols reactive with hydroxyl groups. The polyurethane polyols include reaction products of substantially asymmetric diols which are substantially free of hydroxyl groups separated by 3 carbon atoms or less and pol. n-functional socianates (n = 2-5). This Patent is incorporated herein by reference. ftditionally, the U.S. Patent. No. 5,130,405 of Akzo N.V. discloses acid corrosion resistant coatings including (1) polyurethane polyols prepared from symmetrical 1,3-diol and polyisocyanate components and (2) crosslinking agents reactive with hydroxyl groups, and incorporated into the present by reference. Using any given isocyanate starting material, none of the references cited above discloses a composition or process for making a composition having a controlled molecular weight that permits coatings of high solids content with excessively high viscosity viscosity. class that is possible using the present invention, without resorting to the use of large molar excesses of diol components. The preparation of polyurethane polyols is also possible without the use of isocyanate reagents. The preparation includes the reaction of a mine with a cyclic carbonate, resulting in a urethane group with a hydroxyl group in a beta position to the urethane group. For example, the reaction of a diamine with two moles of ethylene carbonate or propylene will result in a polyurethane diol. Vaccines of this method are found to produce polyurethane polyols in the following patents: U.S. Patent. 3,248,373 to Barpnger, published on 26 fibril, 1966; European Patent 0257848 to Blank published on March 2, 1988; Patent of E.U.fi. 4,611,320 to Parel-'h and others, published on December 23, 1986; Patent of E.U.fi. 4,520,167 to Blan y otr-os, published on May 28, 1985; Patent of E.U.fi. 4,484,994 to Jacobs III et al., Published November 27, 1984; Patent of F.U.fi. 4,268,684 to Gurgiolo, published May 9, 1981; and Patent of E.U.fi. 4,284,750 to ñinbirsal-'is, published on 18th of 1981. Most of the patents that have just been listed describe the use of such polyurethane polyols in entangled coatings. Polymer systems that include these coatings do not provide exceptional chemical resistance or resistance to acid rain. European Patent Application 0 530 806 (Mitsubishi Kasei) discloses linear polyurethane polyols obtained by the reaction of several hydrocarbon diols (having from 7 to 20 carbon atoms) with isofurone diisocyanate, reportedly having Mn of 500 to 20,000. Since both reagents are dysfunctional, the final molecular weight and viscosity must be determined strictly by the OH / NCO ratio and the non-symmetric nature of the dn socion. No modifications are described with the rnonofional reagents. European Patent Application 0 537 900 A2 (Rohm a Haas) discloses thickeners for non-aqueous solvent-containing compositions based on polyol reaction products which contain at least two hydroxyl groups with polyisocyanates which contain at least two isocyanate groups and one active hydrogen compound. The active hydrogen compound may contain hydroxyl groups or primary or secondary arnino groups. The reaction of the isocyanates with the amines to form urea compounds for the control of rheology (ie, thickening) is a well-known technique that is part of the present invention. A summary of JP 0 5,043,6440 discloses polyurethane resins which are prepared by reacting glycols (fi) with polusocyanates (B) in the presence of non-functional hydrogen (C) active compounds (such as monotialcoles), then reacting the Urethane urethane obtained (D) with chain extenders (E) to obtain polyurethane reams of very high molecular weight (Mn >); 200,000). The use of ex, (3-diols and t-diols) is not described A summary of JP 0 4, U7,418fi (Hitachi) describes the preparation of urethane resins in the presence of acrylic monomers to reduce the emissions of Solvents from L2 coatings containing the same. The resins contain (fl) copolymers containing unsaturated ethylene-unsaturated monomers containing hydroxyl groups, as above, (B) poluciates, and (C) reactive diluents consisting of 100-60% by weight of a polyhydric alcohol and 0-40 % by weight of a monoohydric alcohol. Recently, it has become increasingly important, for environmental compliance, to develop polirnecop systems with low viscosities of the solutions, which allow the formulation of coatings with high solids content with low application viscosities. Coatings with a high solids content (greater than about 50% by weight solids) decrease the amount of volatile organic compounds (VOC) that pass into the atmosphere after the drying / curing of the coating. In order to produce acceptable viscosities of the solutions (20-30 sec, Ford viscosity # 4 approximately 25 ° C) for typical high solids coating systems it is necessary that the polymer forming the film has a weight average molecular weight (MP) less than about 5000. To achieve properties of the films in such systems after interlacing, it is also necessary that the number average molecular weight (Mn) exceed about 800 and that each molecular average in number contains at least two. reactive hydroxyl groups. These general principles are applicable to polyester polyols, acrylic polyols and also to urethane polyols when they are entangled with reams of melarnine or with isocyanates. As is evident from the discussion above, the requirements for the acceptable viscosities of the solutions and the good properties of the films lead to contradictory requirements of molecular weights-for the low viscosities of the solutions the Mp must be low, but for good properties of the movies the Mn must be high. The one-component, high-solids, transparent coatings currently used are based on acrylic polyols and molecular weight, typically hexarnetoxirneti lrnelarnin. Acid rain and high solids coating coating systems have been achieved using component systems, such as the polyol-isocyanate systems previously discussed. These coating systems can be used at a total percentage by weight of solids greater than about 50%. However, the presence of reactive isocyanate groups requires the use of a two-component system that must be mixed shortly before use. Two-component systems require additional handling and storage operations and also provide a source of error in the relative amount of ingredients used. Errors that have mixed can adversely affect the quality of the finished coating. The use of isocyanate reactive interlayers requires the use of special safety equipment to avoid the toxic effects that result from human exposure to isocyanate. Unfortunately, this technology is substantially more costly than current one-component coatings, both in terms of the cost of the starting material and the expense involved in retrofitting an existing automotive assembly line to handle two-component coatings. In this connection, it would be advantageous to have a single component isocyanate system which can be applied to a high percentage by weight of solids and which exhibits resistance to acid rain.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention, a polyurethane polymer composition useful as a film-forming material comprises a reaction product of: (a) Approximately one NCO equivalent of an N-functional isocyanate compound, wherein n is a number which varies from two to about 5; (b) x moles of at least one diol or triol of a component or mixtures thereof, is registered to those of substantially non-standard species in which the hydroxyl groups are separated by two or three carbon atoms; and (c) and moles of a compound containing from 1 to 18 carbon atoms and a single functional group capable of reacting with an isocyanate, wherein the sum X + Y is about (1.6 to 1.4 y = about O. Olx at about 75x, with such a ratio of NCO / OH equivalent not exceeding one.These ingredients are preferably combined in a sequence which produces reaction products having polydispersity, for example Mp / Mn <3, or preferably < 2.5, most likely < 2. Compounds of (c) can be selected from a group of unique hydrogen-containing active compounds, containing from 1 to 18 carbon atoms, as expressed in US Pat. 4,394,491, each compound can be described as "rnonoahles", ie organic compounds containing single portions of hydrogen capable of reacting with the isocyanate portions of unsaturated isocyanates by means of an ur-ethane reaction This Patent is incorporated herein by reference. This class includes monoalcohols and thiols, primary and secondary amines and heterocyclic nitrogen compounds containing an active hydrogen linked to a nitrogen atom within the ring. Monoalcohols and thiols are currently referred to. Some of these compounds can be represented by the formulas R-OH, R-SH, R-NH2, R1-NH-R2 and (CH2) 2 = NH, where R is a hydrocarbyl group having 18 carbon atoms or minerals and it can be an alkyl, alkenyl, alkaline, alkanol or the like group, and R1 and R2 are selected from the same family of groups, with a of the carbon atoms in R1 and R2 of 18 or less. The nitrogen-containing heterocyclic rings may contain from 4 to about 7 members selected from carbon atoms, nitrogen atoms and other compatible atoms such as sulfur and oxygen. Preferably, the ring contains only nitrogen and from 4 to about 6 carbon atoms, ie, z = 4 to 6 in the formula. It should be noted that, as used herein, the term "polyurethane polyol" refers to a reaction product in which the major reactants (diol component and polyisocyanate component) are substantially bound only by linkages of urethane. This is in contrast, for example, with the aforementioned modified polyester-urethane and urethane polyester polyols, in which the reactants are linked by means of urethane linkages as well as ester linkages. In addition, these groups include hydroxyl groups as their main functional groups. Optionally, monofunctional alcohols, thiols or other active hydrogen compounds (c) may contain additional polar groups which are substantially unreactive with the isocyanate groups of the n-functional polyisocyanates (a), or even less reactive than the reactive functional groups of isocyanate under typical reaction conditions, as described below and in the examples. Such groups may include nitro groups, carboxylate groups, urea groups, fluoro groups, silicon-containing groups and the like. It is believed that the presence of such functional groups in the alcohols / thiols (c), and therefore in the finished polyurethane polyol, makes such resins better pigment dispersants and also improves the addition to certain substrates of the coating compositions containing the same. further, according to the invention, the polyurethane polyols can be reacted with a suitable dusocyanate to form an adduct having a molar ratio of isocyanate: OH equivalents of no more than about 0.5: 1. Such adducts can be used in coating compositions in the same manner as the polyurethane polyols themselves. In accordance with the invention, the n-functional isocyanate (a) is reacted with the diol or triol or mixtures thereof (b) and said isocyanate reactive compound (c) of such anneal substantially all the isocyanate groups. of said n-functional isocyanate (a) is reacted with a hydroxy group on said diol or triol molecules or with said isocyanate-reactive compound (c), whereby the reactive hydroxyl groups on said diol or triol remain substantially unreacted In accordance with the invention, the above materials for forming coating films can be used in combination with compounds having interlacing functional groups and (optionally) with catalysts to provide a coating material with a high content of solids which is cured and it is dried to a cell having excellent characteristics of interpene resistance, including resistance to acid rain and non-invasive behavior in relation to other materials known to form films. According to one embodiment of the invention, the high-solderable thermosetting coating composition comprises from about 20 to about 80% by weight of a polyurethane polyol as described above, optionally up to about 80% by weight. % by weight of another polyol selected from the group consisting of polyester polyols, polyacrylate polyols and alkyd polyols and from about 10 to about 50% by weight of a partially alkylated rnelamine resin which acts as a crosslinker for the other components, all percentages being based on weight in the total content of carrier solids. Although the composition of the present invention is particularly useful in automotive coatings, it may also be useful for other coatings of the transportation industry, with plastics and for general industrial and decorative applications. The process of the present invention allows exceptionally good control of the molecular weight of the polyurethane polyol, which allows the formulation of the high solids coating with exceptionally low application viscosity. An unexpected beneficial feature of the polyurethane polyols that are produced using this particular class of polyols is that for automotive coatings they provide good rain resistance here when cured with melamine in a one-component coating. Other salient features of the polyurethane polymers of the present invention is that they can be used to produce coatings having good durability against ultraviolet radiation, chemical resistance and other desirable properties not only for the automotive industry, but possibly for other applications as well. ions, such as household appliances, metal furniture and commercial machines, for example. As also indicated above, the diol component is selected from substantially monomeric diols in which the hydroxyl groups are separated by two or three carbon atoms. The component of dio! it may include only one such rnonorneric diols or combinations thereof. For the purposes of the present invention, this class of diols can be divided into "the groups: (i) asymmetric diols - having hydroxyl groups of different order, for example, a primary hydroxyl group and a secondary hydroxyl group and (n) symmetric diols, in which both hydroxyl groups are of the same order, preferably primary. Suitable triols can be used as additions or alternatives to the dols described above., as discussed below, but is not generally preferred because they result in higher viscosity products.

The n-functional isocyanate is substantially monomeric and is therefore di functional, with a functionality of 3 to 4 being very preferable. The isocyanate may be an isocyanurate of an onorneric dusocyanate. For example, the isocyanurate of 1,6-hexarnet? Lend? Soc? Anat. The isocyanate can also be a biuret of an isocyanate monomer; for example, a 1, 6-hexarnet bi? ret? lend? soc? fidernás, the isocyanate can be the reaction product of a dusocyanate and a polyhydroxy compound, such as the product of a metatetrarnetiixilelendusocianato with tpme + iolpropane. In the present invention, isocyanatates are preferred. The amount of isocyanate is chosen so that the ratio of the number of isocyanate equivalents to the number of moles of the monofunctional alcohol (or other isocyanate-reactive compound) and the diol or triol molecules are in the range of from about 0.6 to about 1.4, preferably from 0.9 to 1.1. Typically, the Mp / Mn ratio of the reaction product varies from about 1.1 to about 2.5 or about 3, wherein Mn varies from about 300 to about 3,000, with the most preferred Mn being about 2,500. Coatings comprising the composition for forming polyurethane polyol films, which are described above, may be clear coatings in which the total weight percent of solids in coating varies from about 40% to about 80% and in which the viscosity of the coating material (composition for forming films in a suitable solvent system) over the said range of the solids content is from about 25 cps to about 300 cps at 25 ° C. The compositions for forming polyurethane polyol films of the present invention can also be used in pigmented paint and coating formulations. The total percentage by weight of solids in the coating varies from about 40% to about 80% at which the viscosity of the coating material over the said range of the solids content is from about 25 cps to about 300 cps to about 25 ° C. It has been found that single-coat pigmented coatings that are made using the composition are less prone to yellowing when overcoated after being cured than conventional polyester acrylic enamels. The use of non-functional alcohols / thiols or other compounds of (c) instead of a portion of the diol / tpol component (b) results in polyurethane polyols which have less hydroxyl functionality than those prepared as diols / tpoles only. Such polyurethane polyols, as described in U.S. Patent No. Nos. 5,155,201; 5,130,405 and 5,175,227, all transferred to the benefit of the applicant, have been observed to produce coating compositions that cure films that have many traits. advantageous, including resistance to corrosion walking. Surprisingly, the coating compositions of the present invention which incorporate polyurethane polyols having lower hydroxyl functionality have been found to have equivalent resistance to acid corrosion and reduced viscosity. The combination of the acceptable resistance to acid corrosion (of the cured films) with reduced viscosities (of the polyurethane polyols and coatings containing them) is advantageous, since it allows the formulation of coatings compositions having high content. high solids that have lower volatile organic content (VOC) increasingly requested in the market. Reducing the viscosity of such coating compositions while retaining a similar acid corrosion resistance in cured coatings (as compared to the products of these prior patents) is considered surprising and unexpected because the substitution of non-functional species for diols reduces the content of hydroxyl in the resulting ream and in this way the interlacing density of the network formed when the polyurethane polyol is cured with rnelanma. A polymer chemist would again expect such effects to decrease the chemical resistance properties of the cured coatings which are revised again by increasing the interlacing density.

DETAILED DESCRIPTION OF THE INVENTION Compositions of Polyurethane Folioles The polyurethane urethane polyol composition of the present invention can be synthesized using either isocyanates or polyisocyanates. The isocyanates are n-functional, wherein n is a number ranging from 2 to approximately 5, with functionality from 2 to 4 being preferred and functionality from approximately 3 to 4 being very preferred. Due to variations in the preparation of such isocionatos, the values of n must be either integers or have intermediate values in the numerical ranges indicated. Preferred isocyanates are either biurets or hexane-diisocyanates. Isocyanurates are typically obtained by cyclotransporting three moles of a dusocyte. The biurets are typically obtained from the reaction of res moles of diisocyanate by water rnol. Preferred polyurethane polyol compositions have a number average molecular weight (Mn) ranging from about 300 to about 3,000, with the ratio of their weight-average molecular weight (Mw) varying to the number average molecular weight of about 1.1. approximately 3. Preferably, this ratio (polydispersity indices) varies from approximately 1.1 to approximately 2.5 and preferably approximately from approximately to 2.

Some examples of isocyanates that can be used to synthesize the composition of the present invention include: ducts such as 1, 6-hexarnet? Lend? Soc? Onate, obtainable for example, as HMDI through Miles, formerly Mobay Chemical Corp.; isophorone diisocionate, obtainable as IPDI through, for example, Huís America Inc .; full tetramethylxyl dioxide, obtainable for example, as TMXDT (meta) through citek; dusocionato of 2-rnet Ll-l, 5 ~? entano; dusocionate of 2, 2, 4-t rirnet 11 -i, 6-hexarnet? leno; 1, 12-dodecane and bisois diisocionate (4-c-clohexa-1-isocyanate) of rnetylene, obtainable for example, as Desrnod? r U through Miles; and polyunsaturates such as the bi-ret HMDI, obtainable for example, as Desrnodur N through Miles; the HMDI isolate, for example, as Desrnodur N-3390 through Miles; the isocyanurate of IPDI, obtainable for example, as Desrnod? r Z-4370 through Miles; and the tnisocionato product of rn-TMXDI and of trimethylolpropane, obtainable for example, as Cythano 3160 through Cytek. These isocyanurates and biurets of each dusocycle listed above can also be used to synthesize the compositions of the present invention. There are numerous n-functional solutions obtainable commercially which can be used in the present invention, as indicated above.

Preferred asymmetric diols are those having from 3 to 18, rn? And probably from 4 to 18, and especially from 5 to 12 carbon atoms. Some examples of such asymmetric diols include: 2-et? L-l, 3-hexan-d? Ol (EHDO), available for example, through Union Carbide Corp .; 1, 2-? Ropanod? Ol; 1,3-b? Tanod? Ol; 2,2,4-tprnet? L-l, 3-pentanodol, obtainable for example through Eastrnan Chemical Products, Inc .; and 1,12-octadecanediol, as well as 1,2-hexanedione, 1,2-octanediol and 1,2-decanediol. Preferred of these are 2-et? Li, 3-hexanediol, 1,2-hexanediol, 1,2-octanodol, 1,2-decanodaol and 2,2,4-t-phenethyl-1,3-pentanod. ? ol. Such asymmetric diols can be classified as l, 2- (a, β) and l, 3- (, t) diols. When such diols are reacted with isocyanates under conditions that favor the reaction of substantially isocyclic groups all obtainable with the active hydroxyl groups of the diols, the remaining hydroxyl groups of the diols (or triols) will be constrictively blocked to further reactions. If the synthesis temperature is higher than desired, the reactivity of the second hydroxyl group in the (above) diol molecule which has already reacted with isocylate increases with respect to the hydroxyl groups on the unreacted diol. When this happens, the selectivity of the reaction between the isocylate functional groups and the preferred hydroxyl group is reduced. The ratio in the P / Mn of the polyurethane polyol compound is thereby disadvantageously increased. Therefore, in the synthesis method of the polyurethane polyols of the present invention using asymmetric diols, the synthesis reaction temperature is typically controlled between about 15 ° C and about 120 ° C. The symmetric diols referred to include those having from 2 to 18, preferably from 5 to 18 carbon atoms and especially from 5 to 12 carbon atoms. Some specific examples include ethylene glycol, neopentylglycol, 2,3-butanediol, 2,4-pentanodol, 1,3-propanediol, 2,2-d? Et? -1,3-propanediol and 2-but? l-2-et? ll, 3-? ropanod? ol. Preferred of these are neopentiigiicol, 2,3-butanediol, 2,2-d? Et? -1,3-propanediol and 2-et? L-2-but? Ll, 3-propanediol . Suitable triols having from 3 to about 18 carbon atoms can be used as alternatives to or in addition to the diols described above. The hydrocarbyl groups to which they are linked The hydroxyl groups may be alkyl, alkenyl or alkanyl, with molecular structure and either symmetrical or asymmetric arrangement of the hydroxyl groups (ie, primary or secondary). Such compounds may be represented by the formulas R-OH and R-SH, where R is a hydrocarbyl group having 18 carbon atoms or derivatives and may be an alkyl, alkenyl, alkanyl or similar group. The group R can be linear or branched, cyclic or acyclic, and the alcohols and thiols can therefore be primary, secondary or tertiary. The presently preferred species are the linear primary alcohols and thiols, with short chain alike species having from 2 to about 12 carbon atoms being very preferred. It is generally preferred that the components are reacted at a temperature of about L25 ° C or less, which preferably ranges from about 15 ° C to about 125 ° C. If the reaction temperature is too high or too low, the molecular weight properties of the resulting poly ur-ethane polyols can be undesirably compromised. The effects of low temperature may be due to solubility effects and are therefore dependent on the solvents optionally employed. The portion in time may vary from about 30 minutes to about 24 hours. As mentioned above, the components can optionally be reacted in the presence of a polyurethane catalyst. Suitable polyurethane catalysts are conventional and can be used in conventional amounts. Of course, the particular choice of the type of catalyst and the amount will be determined based on a number of factors such as the particular components and the reaction conditions. These and other factors are well known to those skilled in the art, who may be the appropriate selections as appropriate. Presently preferred catalysts include the tin-containing and tertiary amine-containing compounds, such as tin organometallic compounds and tertiary alkylaryl compounds. The major reactants can be combined in any suitable sequence that produces reaction products having low poly-distress, some variations of which will produce preferred versions of the polyurethane polyols. For example, (i) the isocyanate-reactive functional moiety component (c) can be reacted with the n-functional isocyanate (a) and after that resulting intermediate compound can be reacted with the diol or triol component (b). (This is designated as "method 1"). Alternatively, (n) the n-functional isocyanate (a) can be reacted with a mixture of the diol component (b) and the non-functional component (c), preferably in the presence of a catalyst. (This is designated as "method 2"). fiducially(m) a n-functional isocyanate portion (a) can be reacted with the isocyanate reactive rnonofunctional component (c), the resulting intermediate can then be mixed with the rest of the n-functional isocyanate (a) and the The mixture is reacted with the diol or triol component (b). (This is designated co or "method 3"). As is common in the preparation of polyurethanes, a variety of reaction products can be formed in such fractions, independent of the reagents, their proportions and the reaction sequences employed. For purposes of the present invention, it is desired to obtain substantially homogeneous products having low polydispersity, preferably less than about 2. In some cases it is advantageous to use a small proportion of non-functional polyurethanes together with the polyurethane polyols, either they are generated in situ or added from a separate source. Generally, the reaction products of the processes used to prepare the polyurethane polyols will include species that can be represented by the following structure: 0 0 [HO-R2-0-C-NH -]? '- Rl- ~ C- ~ NH-C-R3] and' wherein R1 is the portion of an n-functional polyisocyanate ranging from 2 to about 5, of which the isocyanate groups are subtracted; R 2 is the portion of a substantially monomeric diol having 2 or 3 carbon atoms between the hydroxyl groups from which it is subtracted at least one hydroxyl group, R 3 is the portion of an active, non-functional compound containing hydrogen, reactive with the isocyanate group from which the active hydrogen is subtracted, and x '+ y' = from 2 to about 5. Preferably the diols of R 2 are selected from a, β-diols and t-diols.

As stated above, a variety of reaction products can be formed in these reactions. For example, polusocyanates that are at least difunctional may be bound together with polyols that have reacted at the ends. The degree to which this occurs depends on the selectivity of the particular diols and isocyanates employed and the degree of func onaiity of the precursor isocanadates. Furthermore, according to the invention, the polyurethane polyols described above can be reacted with dusocyanate to form an adduct, combining the dusocyanate with the polyol in amounts such that as a result equivalent ratios? Soc? Anatos: 0H of no more of approximately 0.5: 1 in the adducts formed. Suitable dusocyanates include those described above for component (a).

Interleavers Two reinforcing interlayers are illustrated in the following examples as being useful with the polyurethane polyol compositions of the present invention for providing cured interlaced coatings. There are numerous kinds of crosslinker-reactive with the hydroxyl group that can be used with these polyurethane polyol compositions such as polusocyanates, blocked polusocyanates and / or aminoplast resins. Blocking agents for the blocked polusocyanate can be carboxymethols, alcohols, phenolic compounds, rnalonic esters or acetoacetates. Aminoplast resins are currently preferred, which in general terms are condensation products with rnelarnine aldehyde, urea, benzoguanarnma or similar compounds. The most commonly used aldehyde is formal deha or. These condensation products contain inethylol or alkyl groups! In this case, alkyl-alkyl groups are usually etherified at least partially with an alcohol, such as methanol or butanol, to form ethers at the sides. The ratchet resin may be substantially uniform or polish depending on the desired final properties of the cured polyurethane polyol coating. The rnelanine resins of rnelanine are preferred because they allow the formulation of coatings with higher solids contents. The polyacrylates are useful in coating in which the use of an acid or strong catalyst should be avoided. Some examples of the linker-ainine are readily obtainable from the class described above include: Hexarnetoxirnetylrnelarnine such as Cyrnel 303, obtainable through Cytek Industries, Inc .; mixed etherethoxy / butoxirnetiiinelarnine, such as Cymel 1135, also obtainable through Cytek; b) Toxirnetylmelarnin polinenco, such as M-281-M, obtainable through Cook Cornposites and PoLyners; and high polymethyl methoxymethylmelanin in irnin, such as Cyrnel 325 available through Cytek. This list could include many other entralazers that differ by the degree of polymerization, the content of irnino, in rnethylol-free content and the ratios of the alcohols used for the etherification. * 22 These aminoplast entanglement agents can be used at widely varying weight ratios of polyurethane polyol of r-splice of armoplast, generally ranging from about 90:10 to 40:60, preferably from about 90: LO to 50:50. Suitable isocyanate crosslinking agents include any of those known for use in similar systems. Specific examples include the briefly described functional isolations n, especially the biuret and isocionurato versions. The blocking of said isocyanates is well known to those skilled in the art and does not need to be detailed in the present invention. In the case of the aminoplast entanglement agents, the isolating interlacing agents can also be used in widely varying amounts, but generally in an equivalent ratio of hydroxyl groups to isocyanate ranging from about 0.7 to about 2.2.

Entangle Catalyst The entanglement catalyst used in the following examples was a blocked dodecylbenzene sulfonic acid, such as Nac? Re 5226, available from King Industries. Other acid catalysts can also be used. Acid catalysts are used to increase the rate of crosslinking reaction in compositions cured with rnelamine. Generally, from 0.1 to 5% by weight of the catalysed "active Jor, based on the content of non-volatile compounds of the coating formulation is used. These acids? Ue < can be blocked by means of an appropriate compound, since the catalyst is inactive until < That the coating is baked. Optionally, the catalyst can be used in an unblocked form, which may require the formulation of a two component coating. As a coating of an individual component is preferred, for the reasons described above, the following work was done using an acid catalyst blocked in a one component system. Examples of acids that can be used include phosphoric acid, alkyl acid phosphates, sulonic acids and substituted sulphonic acids, and rnaleic acid or alkyl acid monolates. Examples of readily available catalysts include: para-toluene-lfonico acid (PTSA) such as Cycat 4040, available from Cytek; dodecylbenzene sulphonic acid (DDBSA) such as Bio-Soft 5-100, available from Stepan; Phosphoric acid phosphate (PAP); DDBSA blocked by amines, such as Nacure 5226 and Nacure XP-158, available from King Industries; PTSA blocked by amine, such as VP-451, available from Byk-Mallinckrodt; dinonylnaphthalene disulfonic acid (DNNDSfl); and rnaleic acid. This list may include numerous additional catalysts (blocks "unblocked") known to those skilled in the art. The type of catalyst used is determined by the desired baking program. Depending on the type of catalyst used, the baking connections are typically around 80 ° C to about 200 ° C. The light coatings described in the present invention can be modified to produce pigmented coatings or coatings. Paint formulations often contain various flow-additives, surface tension adjustments, pigment circulation, or solvent loosening. Some typical additives are cited below: flow adjuvants such as polybutylene lacp of fi-620-fi2 , available from Cook; ilicon Byk-320, available from Byk-Mallinc rodt; pigment moistening agents such as Disperbyk, available from Byk-Mali inc rodt; UV light absorbers, such as T uvm 900 from Ciba; and hindered amine light stabilizers, such as Tinuvin 292 from Giba. Other additives can also be used. The coatings can contain from 0 to 400% by weight of p? < Suitable grinders and / or extenders based on the combined weights of the polyurethane polyol and the interlayer-, and from 0 to 15% by weight of additives to improve the properties of the coating, based on the total solids content of the coating. These coating compositions can be applied to any number of well-known substrates of any number of conventional application methods. The curing of the coatings can be carried out under various conditions, although the curing of the one-component systems described above is preferably carried out under baking conditions, typically from about 80 ° C to about 200 ° C. The above generated discussion of the present invention will be further illustrated by the following specific but limiting examples.

EXAMPLES Synthesis of polyurethane polyols COMPARATIVE E3EMPLOS I, II AND III For use as controls, the polyurethane polyols based on isocyanates and diols (only) without the monofunctional species of the present invention, were prepared in accordance with the methods of Example 1 of the co-assigned US patent. No. 5,155,201 (previously incorporated by reference). Representative ingredients and properties of the polyols are shown in Table I below.

Examples IV and V are non-functional polyurethanes prepared by method 2, with sufficient isocyanate used to react with all available hydroxyl groups. As such, it is equivalent to the complete replacement of the diol reagent by a monofunctional species such as alcohol.

Coatings formulated using the polyurethane polyol composition TABLE I Polyurethane polyols prepared with long-acting alcohols Exemplary alcohol / HDT method LV Des 3300 JHDO lonofunctional DEPD Z from NV Vise.20C Hn n «/ n I 1.0 eq l.Oi 72.7 4470 1778 1.56 II 1.0 eq l.Ol 60.4 1330 1642 1.37 III 1.0 eq l. (74.6 6100 1598 1.33 IV 1.0 eq l.DOi slUT 75.1 1020 963 1.25 V 1.0 eq 1.001 slUT 69.9 400 1093 1.32 1/1 1.0 eq 0.67? 0.33? slUT 69.4 940 1378 1.48 2/1 1.0 eq 0.601 0.40? SlUT 73.9 3025 1500 1.84 3/1 1.0 eq 0.501 0.401 SlUT 59.9 700 1390 1.47 4/1 Or eq 0.33? 0.671 slUT 70.9 500 1284 1.44 /1 1.0 eq 0.33? slUT 0.671 72.2 1040 1442 1.37 6/2 1.0 eq 0.73? 0.27? EH 66.7 1360 1912 2.06 7/2 1.0 eq 0.65? 0.35? OCDA 70.0 N / A 1926 1.62 8/2 1.0 eq 0.65? 0.35? DDA 67.2 1500 1857 1.57 9/2 1.0 eq 0.73? 0.27? DA 60.2 1440 2031 1.64 /2 1.0 eq 0.001 0.20? DA 66.9 1600 2182 1.92 11/3 1.0 eq 0.67? 0.33? SlUT 74.0 3005 1528 1.84 HDT LV = isocyanurate-containing trisomer ring of HHDI 1EPD = 2-butyl-2-ethyl, l, 3-pypannediol EHDO = 2-ethyl, l, 3-hexanediol Des 3300 - (Desiodur 3300) - isocyanurate of HflDI EH - 2-ethexanol DA = decyl alcohol OCDA = octadecanol DDA = dodecanol slUT = secondary butanol HflDI - hexaethylene isocyanate EXAMPLES 1 fl 5 (Method 1, monoalcohol reacted with NCO, and intermediate or added after daol) In these examples, rnonofunctional alcohol is added to the entire isocyanate component, and the resulting intermediate is then added to the diol component for reaction. Representative reaction procedures are described below.

EXAMPLE 1 Pol 10 I of polyurethane obtained by the reaction of secondary butanol and 2-et l-l, 3-hexanod? L (EHDO) with Desmodur 3300 (hexarynet dioxide dionsion isolate) Reagents: Reagent Weight eq. Grams Fq's% by weight Kettle Charge (fi) DBTDL at 10% 74. 12 146. 0 1. 97 5. 409 10 (in butyl acetate) Feeding (B) 15 Des 3300 194.0 1.158.2 5.97 42.907 Methyl arnyl ketone 809.2 29.978 Kettle Charge (C) 20 EHBO 146. 0 584. 0 8. 0 21,635 DBTDL to 10% 0. 5 0.022 (in huta acetate lo) "25 DBTDL Tin Dibutyl Dilaurate In a 4NRB 5 flask equipped with a reflux condenser, mechanical agitator, thermometer, adapter for rnonornero input, and maintained under a nitrogen atmosphere, the boiler charge (B) was placed. After heating the mixture to 70 ° C, feed (A) was added at 1.3 ml / inin (2hrs), maintaining the temperature at 70 ° C. 35 This mixture (fiB) was kept at 70 ° C for 1.5 hours, cooled to room temperature and transferred to a can of 3.78 1. The boiler charge (C) was placed in the original 5 liter 4NRB flask (which previously it was rinsed with solvent). After heating (or at 70 ° C, the feed (AB) was added at 14.5 rnl / rnm (2 hr) After completing the addition of the feed, the temperature was maintained at 70 ° C for another 1.5 hours, after which the ream was cooled and transferred to a container of 3.78 1. The percentage of non-volatile compounds was measured in samples of approximately 0.5 g, diluted with approximately 1.0 g of MAK, stirred with a tarred paperboard, and heated for 1 hour at 110 ° C. The viscosity of Brookfiel Viscosity was given using a spindle of number 4, at 10 rpm, at 25 ° C. The molecular weights are by GPC, using polyethylene glycol / polystyrene standards. of non-volatile compounds: 70.0 (in theory); 69.4 (replenished) Hydroxyl Weight: 473 Viscosity: 940 rnPa.S PMn: 1378 PMp: 2035 PMp / PMn: 1.5 The remaining examples 2 to 5 were prepared using similar reaction procedures The proportions of the reagents and the results all are shown in table T.

EXAMPLES 6 TO 10 (Method 2, NCO added to a mixture of diol and monoalcohol) EXAMPLE 6 Polyurethane polyol obtained by the reaction of secondary b? Tanol and 2-et? L-l, 3-hexanod? Ol (EHDO) with Desmodur 3300 Reagents Weight Weight Quantity Equivalents / 2 equivalent • olecular Roles fl: Boiler load 2-ethyl-l-hexanol 130.00 130.00 228.20 1.75 7.322 2-ethyl-l, 3-hexanediol 146.00 73.00 692.80 4.75 22.212 2-heptanone 467.40 14.992 DDTDL solution at 102 2.20 9.072 in n-butyl acetate 1: isocylate filtration Desiodur isosiconate N-3300 194.00 1261.00 6.50 40.432 2-heptanone 467.40 14.992 3119.0 100.002 Characterization: 2BZ of non-volatile co-units: Theoretical: 70.80Z 71.002 Actual: 67.BOX 67.602 Equivalent weight of OH: Theoretical: 4S9.4 459.4 Viscosity of irookfield: 1360 iPa.s end: 1912 Ru: '393S Hv / Rn: 2.08 In a 5-liter, 4-necked, round-bottomed flask equipped with a reflux condenser, mechanical stirrer, thermocouple, heating mantle, heating mantle, nitrogen-bearing adapter, and maintained under a nitrogen atmosphere, I place the boiler load (fi). After heating the mixture at 7 ° C, the isocyanate feed (B) was added for a period of 2.5 to 3 hours at a rate of approximately 11.5 ml / ml with a Masterflex peristaltic pump and Vi ton # tube. 16 keeping the temperature at 70 ° C all the time. the resin was maintained for another 1.5 hours at 70 ° C, then cooled to room temperature and decanted in a metal can of 3.7R 1. The percentage of non-volatile compounds was measured in samples of approximately 0.5 g, Diluted with approximately 1.0 g of 2-hethoneone, stirred with an alkylated paper clip, and heated for 1 hour at 110 ° C. The viscosity of Brook ield was measured in a resin sample at 25 ° C using a # 4 spindle at LO.O rpm. Molecular weights were determined by gel permeation chromatography using polyethylene glycol / polystyrene standards. The remaining examples 7 to 11 were prepared using similar reaction procedures. The proportions of the reagents, and the results are shown in Table I.

EXAMPLE 12 (Method 3, the reaction product of the alcohol and the part of Isocyanate is mixed with the isocyanate residue, and the mixture is then added to the diol) Polyurethane polyol obtained by the reaction of secondary b? Tanol and 2-et? L-l, 3-hexadod? Ol (EHDO) with Desrnodur 3300 Reagents: Reagent Weight eq. Grams Eq's% by weight Load of Cal was (fi) butanol sec. 74.1? 224.1 3,023 5,800 rnetilarnilcetona 257.9 6,672 DBTDL at 10% (in butyl acetate) 0.9 0.023 Feeding (B) Des 3300 194.0 1,777.0 9,160 45,971 Methylarylketone 450.0 11,641 Boiler Load (C) EHBO 146.0 896.0 21,635 23,179 Methylamine ketone 257.8 6,669 DBTDL to 10% 1.8 0.047 (in buyl acetate) DBTDL = Tin Dibutyl Dilaurate In a 5 liter 4NRB flask equipped with a reflux condenser, mechanical stirrer, thermometer, adapter for inlet of nitrogen, and maintained under a nitrogen atmosphere, the boiler charge (fi) was placed.

After heating the mixture to 70 ° C, feed (B) was added at 8.1 rnl / rnin (2hrs), maintaining the temperature at 70 ° C. The remaining 60% of feed (B) was added for 10 minutes, still maintaining the temperature at 70 ° C. This mixture (RB) was transferred to a 3.78 1 can and cooled to room temperature. The boiler charge (C) was placed in the original 5 liter 4NRB flask (which was previously rinsed with solvent).

After heating (C) to P0 ° C, the feed (fiB) was added at 17.0 rnl / inin (2 hr). After the addition of the feed was completed, the temperature was maintained at 70 ° C for another 1.5 hours, after which the resin was cooled and transferred to a container of 3.78 1. The percentage of non-volatile compounds was measured. in samples of approximately 0.5 g, diluted with approximately 1.0 g of MflK, stirred with a tarred paperboard, and heated for 1 hour at 110 ° C. The faithful Broo viscosity was measured using a spindle of number 4, at 10 rprn, at 25 ° C. The molecular weights are by GPC, using polyethylene glycol / polystyrene standards. Characterization:% of non-volatile compounds: 75.0 (in theory); 74.0 (measured) Hydroxyl equivalent weight: 472 Viscosity: 3085 rnPa. PMn: 1526 PMp: 2807 PMp / PMn: 1.84 PROOF OF GROBODO MONCH WITH OCCULT Table II below describes the etching properties of polyurethane urethane polyol resins, modified with rnonofunctional alcohol (secondary butanol). All reams were incorporated into formulations consisting of 35 wt.% Of rnelarnine (Cyrnel 303), 11% of MPL-200 (a polyurethane polyol, prepared as in the TI example from HDTLV and 2-et? L - l, 3-hexanod? ol (which was incorporated into the formula in a fumed silica dispersion for rheology control), 3% resin from commercial additives and 51% resin PUPO. All formulas contained (based on resin solids) acid catalyst Nacure 5226 at 0.4%, UV light absorber Sanduvor 3206 at 2.7%, light stabilizer on hindered amine Tinuvín 440 at 1.34%, fumed silica flerosil R972 at 10.6% and flow agent Coroc fl-620-fl2 at 0.4%. Substitution of the diol with onofunctional alcohol was made at 1/3, 1/2 and 3/2 molar replacement by mixing MPL-200 (the polyurethane polyol of Example I) with a non-functional polyurethane of Example III (MPL-457 ) or using resins q? e were prepared by reacting combinations of rnonoalcohol / diol with demifunctional isocyanate Desmodur 3300, using the method described above. The light coatings were sprinkled over a black base coating of wet-on-wet acrylic / melamine, and baked for 17 minutes at 143. ° C (metal temperature). It was determined that 4? all the dry films are between 45.72 and 53.34 u. The movies < -, and tested for resistance to etching with acid by the acid stain test described in the U.S. Patent. No. 5,130,405, column 11, incorporated herein by reference. A simulated solution for acid rain was formulated by mixing a normal aqueous solution of sulfuric, nitric and hydrochloric acids at a volume ratio of 65/30/5, respectively. The resulting acid mixture had a μH of 0.2 units. The panels prepared in the examples were tested for acid resistance. Each panel was stained with 0.5 rnl of the aforementioned acid solution, and allowed to stand without covering at room temperature. The evaporated water was replaced with another acid solution at regular intervals (2 hours) so that the size of the stain would remain the same during the entire test, filtering the exposure time, the panel was rinsed with distilled water and of or that will dry during the night. The panels were inspected to observe the changes the next day. The exposure times needed to damage the different systems are shown below in the TI box.

TABLE II PROOF OF RUNCH OF 6RA1ADO WITH ACIDO OF THE REVESTItLIENTOS Ejecil / method Ratio of the breed Level of preparation type (based on solids Type Butanol level of the lisia) Diol secondary diol ring (doles) (toles) Coiparativo Ejelo II ... EHDO 1.0 0.0 9 /1 - 1EPD 0.67 0.33 10 1/1 - EHDO 0.57 0.33 8 Mixture of II to V 0.67: 0.33 EHDO 0.67 0.33 8 3/1 - EHDO 0.5 0.5 7 Mixture of II S V 0.5: 0.5 EHDO 0.5 0.5 10 4/1 - EHDO 0.33 0.67 10 Mixture of II 8 V 0.33: 0.57 EHDO 0.33 0.67 10 Control of acrylic coiercial * - - ... ... 3 * A clear coating of interlaced lelaiin acrylic produced coiercialiente.

Several important conclusions can be reached from these data: 1) Polyurethane polyols can be prepared from mixtures ofnonfunctional alcohols and diols to give coatings with etch resistance. However, as seen in Table I, the viscosities of these "modified" polyurethane polyols were less than those of conventional polyurethane polyols such as comparative examples I, TI and III. 2) There is no great difference between the etch resistance properties of coatings based on the mixture of non-functional polyurethane polyols and polyurethane polyols totally diol derivatives, and coatings based on polyurethane polyols having the same level of non-functional alcohol that reacts in the polyol in a statistically random manner. 3) Polyurethane polyols prepared from 2-butyl-2-yl-l, 3-propanediol (BEPD) are better than those prepared from 2-yl? i -l, -hexanod? ol. Species prepared from BEPD produce coatings that have greater resistance to etching with acid. Pun when you do not want to link it to the theory, you think that this is due to the steric hindrance provided by the bulky butyl groups.

COMPUTER EXAMPLES VI X The resin solution of Example I (a conventional polyurethane polyol) was used to formulate clear interlaced rnelanine coatings at 30 and 40% by weight of hexarnetoxirnethyllene, based on the total resin solids, comparison way, a typical hydroxy-functional polyaplate was formulated in coatings at the same levels of rnelarnine. All samples were catalyzed with an acid catalyst such as Nac? Re 5226 available from King Industries, in active catalyst at 0.38% based on the resin solids. Samples were reduced to 60% nonvolatile compounds (NV) with butyl acetate, and brought to a dry film thickness of 1.5-1.8 rmls on aluminum test panels. The coatings were cured for 30 minutes at approximately 121. 1 ° C. The panels produced in these examples were subsequently tested for acid resistance as described above for the examples in Table III.

CODE III EXAMPLE / LEVEL OF HOURS FOR THE HOURS FOR MELAMINE POLYMER FIRST STAIN THE FIRST DEGRADATION VI lato-functional polyap 30% No degradation after 7 hours.

VII polyacrylate to hydroxy- 45% functional VIII polio! of 30% urethane-free polyurethane, 7 hrs, IX polyol of 45% non-stained polyurethane, 7 hrs X two-component acrylic urethane without stain, 7 hrs The above data suggests that a significant improvement in acid resistance can be obtained by replacing an acrylic resin with a polyurethane polyol of the co-assigned U.S. Patent. No. 5,155,201. The interlaced rnelarnine polyurethane polyol coatings exhibited an acid resistance approaching that of a two component acrylic urethane control, which is known for its acid resistance. The two-component coating was an acrylic urethane based on a hydroxy-functional polycarbonate resin, which was entangled with Desmodur- N-3390 from Miles. The coatings prepared from the polyurethane polyols of the present invention provide comparable strength to etching with acid when cured, with the advantage of showing lower viscosity during application.

HYPOTHETICAL EXAMPLE XI A single-layer pigmented top coat is prepared as follows: about 150 parts by weight of the polyurethane polyol of the type described in the previous examples is placed in a mixing flask. To this is added about 183 parts of titanium dioxide pigment (Titanox 2160, available from N.L. Chemicals Inc.). The two materials are mixed using high speed dispersion equipment. After the pigment dispersion, the following ingredients are added: about 106 parts by weight of rnelamine crosslinker (Cyrnel 303, available from Cytek); about 53 parts by weight of solvent (butyl acetate); Approximately 12 parts by weight of blocked acid catalyst (Nacure 5226, available from King Industries); about 96 parts by weight of an additional solvent (rnetii arnil ketone); and about another 150 parts by weight of the same polyurethane polyol. The non-volatile content of the resulting white top coat is about 65.0% by weight. This topcoat is applied to 20-gauge steel phosphating test panels using commercially available spray-spray equipment to a dry-cured coating thickness of approximately 2.0 rnils. The coating is dried and cured by baking in an oven at approximately 121.1 ° C for a period of about 30 minutes. Only a limited number of preferred embodiments of the present invention have been described above. However, those skilled in the art will recognize the numerous substitutions, modifications and alternatives that may be made without departing from the spirit and scope of the invention, as are limited by the following claims.

Claims

NOVEDOD OF THE INVENTION CLAIMS

1. - A polyurethane polyol composition comprising the reaction product of: (a) about one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5; (b) x moles of at least one component gave! or triol or mixtures thereof, said diol or triol being selected from substantially monomeric species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; and (c) and moles of a compound containing 1 to 18 carbon atoms and an individual functional compound capable of reacting with an isocyanate, wherein the sum of x + y is approximately 0.6 to 1.14 and y = a O .Ox to approximately 75x, provided that the equivalent NCO / OH ratio is less than 0.976.

2. The composition of claim 1, further characterized in that said n-functional isocyanate (a) is selected from the group consisting of the isocyanurates and biurets of monomeric dusocyanates, and reaction products of dusocyanates and polyhydroxy compounds.

3. The composition of claim 2, further characterized in that said isocyanate (a) is selected from the group consisting of hexarnetylene dusocyanate, isophorone dusocyanate, tetrarnetiixylylene dusocyanate, 2-? Net? 11 dusocyanate, 5- enanthane, dusocyanate of 2, 2, 4 -t prneti i -i, 6 -hexaneti log, diisocyanate 1,12-dodecane, and b? s (4-c? clohex? l isodanate) of rnetylene.

4. The composition of claim 1, further characterized in that said diol or triol is asymmetric.

5. The composition of claim 4, further characterized in that said diol is selected from the group consisting of 2, 2, 1-tprneti L-1, 3-entanodol, 2-yl. -1, 3-hexanod? Ol; 1, 2-propanod? Ol; 1,2-hexanediol; 1,2-octanediol; 1,? -decanod? Ol, l, 2-octadecanod? Ol and 1,3-butanediol.

6. The composition of the rei indication 1, further characterized in that said diol or triol contains hydroxyl groups that are rich sunet.

7. The composition of claim 6, further characterized in that said hydroxyl groups are all primary.

8. The composition of claim 1, further characterized in that the isocyanate reactive compound (c) is a single active hydrogen-containing compound.

9. The composition of claim 1, further characterized in that said compound (c) is an alcohol or thiol characterized by the formulas R-OH and R-SH, wherein R is the hydrocarbyl group containing from 1 to 18 carbon atoms which may be alkyl, alkenyl, aplo or alloy.

10. The composition of claim 9, further characterized in that said compound (c) is an aiiphatic alcohol having from about 2 to about 12 carbon atoms.

11. The composition of claim 1, further characterized in that said compound (c) is an amine selected from the group represented by the formulas R-NH2 and R1-NH-R2 and (CH2) 2-NH, wherein each R is a hydrocarbyl group that has from 1 to 18 carbon atoms, the sum of the carbon atoms in Rl and R2 also being from 1 to IB, and where z = from 4 to approximately 6.

12. - The polyurethane polyol composition of claim 1, further characterized in that the ratio of the weight average molecular weight (Mw) to the average molecular weight number (Mn) ranges from about 1.1 to about 3, and wherein Mn from about 300 to about 3000.

13. A polyurethane polyol composition comprising the reaction product of: (a) about one NCO equivalent of an n-functional isocyanate compound, wherein n is a number that varies 2 to about 5; (b) x moles of at least one component diol or triol or mixtures thereof, said diol or triol being selected from species essentially unrelated, where the hydroxyl groups are separated by 2 or 3 atoms. carbon; and (c) and moles of a compound containing 1 to 18 carbon atoms and a single functional compound capable of reacting with an isocyanate, and at least one additional functional group which is a polar group and is reactive with groups isocyanate that said functional group reacts with isocyanate ba or typical reaction conditions, where the a su of x + y is approximately 0.6 to 1.14 and y = a O.Olx at approx imadarne 75x, provided that the equivalent ratio of NCO / OH does not exceed unity.

14. The polyurethane polyol of claim 13, further characterized in that said polar group is selected from the group q? E consisting of a nitro group, carboxy lato group, urea group, fluoro group and groups containing illicium.

15. A method for preparing a polyurethane polyol composition comprising the steps of: (a) providing approximately one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5; (b) providing about x moles of at least one substantially continuous diol or triol or mixtures thereof, wherein the hydroxyl groups in each diol or triol molecule are separated by 2 or 3 carbon atoms; and (c) providing approximately and moles of a compound containing from 1 to 18 carbon atoms and an individual functional compound capable of reacting with an isocyanate, wherein the sine of x + y is about 0.6 to 1.14 and y = a O.Oxx at approximately 75x, provided that the equivalent NCO / OH ratio is less than 0.976; and (d) reacting said n-functional isocyanate (a) with said diol or triol or mixtures thereof (b) and the isocyanate reactive compound (c).

16. The method of claim 15, further characterized in that said n-functional isocyanate (a) is reacted with said diol or triol or mixture thereof (b) and said isocyanate reactive compound (c) in a manner such that substantially all of the isocyanate groups of said n-functional isocyanate (a) are reacted with a hydroxyl group in said diol or triol molecules or with said isocyanate-reactive compound (c), whereby the hydroxyl groups less reagents in said dio or triol remain substantially unreacted.

17. The method of claim 15, further characterized in that the reaction of step (d) is carried out in the presence of a catalyst, and further characterized in that the concentration of said catalyst varies from an effective amount of 0.1 to about 5% by weight based on non-volatile solids.

18. The method of claim 17 further characterized in that said catalyst is selected from the group consisting of organometallic compounds and tertiary alkylarynins.

19. - The method of claim 18, further characterized in that said catalyst is a tin compound organometalllco.

20. The method of claim 15, further characterized in that said nfunctional isocyanate (a) is selected from the group consisting of rnonorneric dusocyanate isoclanurate, biurets of heterocyclic diisocyanates, and reaction products of dusocyanates and polyhydroxy compounds. .

21. The method of claim 15, further characterized in that the reaction step (d) is carried out on a temperature scale of about L5"C to about 125 ° C for a period that varies from around 30 minutes to about 24 hours.

22. The method of claim 15, further characterized in that the Isocyanate and the components (diol or triol) are continuously bonded by means of ur-ethane bonds

23. The method of claim 15, further characterized in that said component Diol or trioL (b) and said isocyanate reactive component (c) are mixed and reacted in the presence of a catalyst with the isocyanate component

24. The method of claim 15, further characterized in that said component or reagent of isocyanate (c) is reacted with said isocyanate component (a) and the resulting intermediate is then reacted with said diol or triol component (b).

25. - The method of claim 15, further characterized in that a portion of said n-functional isocyanate (a) is reacted with said isocyanate reactive component (c), the resulting intermediate is then mixed with the rest of the n-functional isocyanate (a) and the resulting mixture is reacted with said diol or triol component (b).

26. The method of claim 25, further characterized in that said component (c) is an alcohol or thiol characterized by the formulas R-OH and R-SH, wherein R is the hydrocarbon group which contains from 1 to 18 carbon atoms that can be alkyl, alkylene, aryl or alkanol.

27. The method of claim 15, further characterized in that said isocyanate reactive component (c) is an individual compound containing active hydrogen.

28. The method of claim 15, further characterized in that said isocyanate reactive component (c) is a primary or secondary amine.

29. A method for preparing an adduct of a polyurethane polyol and a dusocyanate comprising the step of reacting a dusocyanate with the reaction product of the method of claim 15.

30.- A coating composition comprising: a) polyurethane polyol composition comprising the reaction product of: (1) about one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5; (2) x moles of at least one diol or triol component or mixtures thereof, said diol or triol being selected from substantially monomeric species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; and (3) and moles of a compound containing 1 to 18 carbon atoms and an individual functional compound capable of reacting with an isocyanate, wherein the sum of x + y is about 0.6 to 1.14 and y = aO.Olx a approximately 75x, provided that the equivalent NCO / OH ratio does not exceed unity; (b) an interleaver selected from the group consisting of arni oplastic reams, polusocyanates, and blocked polusocyanates; (c) 0.1 to 5% by weight of a suitable catalyst for the crosslinking reaction between the polyurethane polyol of step (a) and the crosslinker of step (b) based on the non-volatile content; (d) a solvent or solvent mixture compatible with the total coating composition; (e) 0-400% by weight of suitable pigments and / or extenders based on the combined weights of the polyurethane polyol of step (a) and the interleaver of step (b); and (f) 0 to 15% by weight of additives to improve the coating properties, based on the total solids content of the coating, further characterized in that the solids refer to the weight of the cured coating.

31.- The coating composition of the r-e? Vmd? cation 30, further characterized in that said interleaver is an ammoplastic ream.

32. The coating composition of claim 31, further characterized in that the arninoplasty resin is selected from the group consisting of condensation products of melamine aldehyde, ream of urea, benzoguanarnin resin and partially or partially ether totally rented from them.

33. The coating composition of claim 31, further characterized in that said aminoplastic resin is reacted with an alcohol to form ether at least partially alkylated thereof.

34. The coating composition of claim 30, further characterized in that said interleaver is a polusocyanate or blocked polyneocyanate.

35. The coating composition of claim 34, further characterized in that the blocking agent for the blocked polusocyanate is selected from the group consisting of ketoxirnes, alcohols, phenolic compounds, rnalonic esters, and acetoacetates.

36. The coating composition of claim 30, further characterized in that said polyurethane polyol has? N Mw / Mn ranging from about 1.1 to 3 and an Mn ranging from about 300 to 3000.

37.- The composition of coating of claim 30, further characterized in that said polyurethane polyol is reacted with at least one dusocyanate to form an adduct therewith.

38.- A high-solids, thermally cured coating composition, comprising: (a) about 20% to about 80% by weight of a polyurethane polyol composition comprising the reaction product of: (1) about one NCO equivalent of an isocyanate n-functional compound, where n is a number that varies from 2 to approximately 5; (2) x moles of at least one diol or triol component or mixtures thereof, said diol or triol being selected from substantially nonnorneric species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; and (3) and moles of a compound containing from 1 to 18 carbon atoms and an individual functional compound capable of reacting with an isocyanate, wherein the sine of x + y is approximately 0.6 to 1.14 and - to O.OIx to approximately 75x, provided that the equivalent NCO / OH ratio does not exceed unity; (b) ap-ox imadarnent 0% to about 80% by weight of a polyol selected from the group consisting of polyester polyols, polyacrylate polyols and alkyd polyols; and (c) from 10% to about 50% by weight of a ream of at least partially alkylated rnelamine acting as a crosslinker for components (a) and (b); with the above weight percentages being based on the total solids content.

39.- A polyurethane polyol composition comprising reaction products characterized by the structure 0 0 CH0-R2-0-C-NH-]? '- RI-CMH ~ C-R3] -y' wherein R1 is a portion of n-functional polyisocyanate, with n ranging from 2 to about 5, of which the isocyanate groups are subtracted, R2 is the portion of a substantially monomeric diol selected from the group consisting of -β-diols and -t-diols of which the hydroxy groups are subtracted, R 3 is the portion of a monofunctional reactive compound of isocyanate group containing active hydrogen containing 18 carbon atoms, of which active hydrogen is subtracted, and x '+ y' = from 2 to 5, and the equivalent ratio of NCO: OH is less than 0.976.

40.- A mixture of the polyurethane polyol composition of claim 1, with a non-functional polyurethane.

41. A mixture of the polyurethane polyol composition of claim 13, with a non-functional polyurethane.

42. The method of claim 15, further comprising the step of: (e) mixing the resulting polyurethane polyol with a non-functional polyurethane.

43.- The coating composition of claim 30, further comprising: (g) a non-functional polyurethane.

44. - A high-solids thermal setting coating composition comprising: (a) from about 20% to about 80% by weight of a mixture of: (i) a polyurethane polyol comprising the product of reaction of: (1) supproximately an NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5; (2) x moles of at least one diol or triol component or mixtures thereof, said diol or triol being selected from substantially monomeric species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; and (3) and moles of a compound containing 1 to 18 carbon atoms and an individual functional compound capable of reacting with an isocyanate, wherein the sum of x + y is about 0.6 to 1.14 and y = aO.Olx a approximately 75x, provided that the equivalent ratio of NCO / OH does not exceed one unit, and di) a non-functional polyurethane; (b) about 0% to about 80% by weight of a polyol selected from the group consisting of polyester polyols, polyacrylate polyols and alkyd polyols; and (c) from 10% to about 50% by weight of a ream of at least partially alkylated reactant acting as a crosslinker for the components (a) and (b); with the above weight percentages being based on the total solids content.

45.- A mixture of the polyurethane polyol composition of claim 39 with a non-functional polyurethane.

46. A polyurethane polyol composition which comprises: (i) about 33 to 67% of the reaction product of: (1) about one mole of an n-functional isocyanate compound, wherein n is a number It ranges from 2 to about 5, and (2) from 0.8 to 1.2 n moles of at least one diol or triol component, or mixtures thereof, said diol or triol being selected from substantially monomeric species. , where the hydroxyl groups are separated by 2 or 3 atoms of carbon; (n) Approximately 33 to 67% of the reaction product of: (1) about one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) a mold a compound containing 1 to 18 carbon atoms and an individual functional group capable of reacting with an isocyanate.

47.- A polyurethane polyol composition comprising: (I) about 33 to 67% of the reaction product of: (1) about one mole of an n-functional isocyanate compound, wherein n is a vain number of 2 to about 5, and (2) from 0.8 to 1.2 n moles of at least one diol or triol component, or mixtures thereof, said diol or triol being selected from substantially non-normal species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; (2) about 33 to 67% of the reaction product of: (1) about one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) a mold a compound containing 18 carbon atoms, an individual functional group capable of reacting with an isocyanate, and at least one additional functional group which is a polar group and is reactive with isocyanate groups that said reactive functional isocyanate under typical reaction conditions.

48. A method for preparing a polyuret-polyol composition not comprising the steps of: (a) reacting approximately n-nol of an n-functional L-cyanate compound, wherein n is a number of th from 2 to about 5, with about 0.8 to 1.2 n moles of at least one substantially identical diol or triol, or mixtures thereof, wherein the hydroxyl groups in each diol or triol molecule are separated by 2 or 3 atoms of carbon; (b) reacting approximately one NCO equivalent of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, with about one mole of a compound having from 1 to 18 atoms carbon and an individual functional group capable of reacting with an isocyanate; (c) rnequing about 33 to 67% of the reaction product of (a) with about 33 to 67% of the reaction product of (b). 49.- A coating composition comprising: (a) a mixture of (i) about 33 to 6% of the reaction product of: (1) about one nmr of a n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) from 0.8 to 1.2 n moles of at least one diol or triol component or mixtures thereof, said diol or triol being selected from substantially non-normal species, wherein the hydroxyl groups are separated by 2 or more. or 3 carbon atoms; (n) about 33 to 67% of the reaction product of: (1) about one NCO equivalent of a n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) a mold a compound containing from 1 to 10 carbon atoms and an individual functional group capable of reacting with an isocyanate; (b) an interleaver selected from the group consisting of arnmoplastic resins, polusocyanates, and blocked polusocyanates; (c) 0.1 to 5% by weight of a suitable catalyst for the crosslinking reaction between the polyurethane polyol of step (a) and the crosslinker of step (b) based on the non-volatile content; (d) a solvent or solvent mixture compatible with the total coating composition; (e) 0-400% by weight of suitable pigments and / or extenders based on the combined weights of the polyurethane polyol of step (a) and the interleaver of step (b); and (f) 0 to 15% by weight of additives to improve the coating properties, based on the total solids content of the coating, further characterized in that the solids refer to the weight of the cured coating. 50.- A high-solids thermal setting coating composition comprising: (a) about 20% to about 80% by weight of a mixture of: (i) about 33 to 67% of the reaction product of: (1) about one nn of an n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) from 0.8 to 1.2 n moles of at least one diol or triol component, or mixtures thereof, said diol or triol being selected from substantially monomeric species, wherein the hydroxyl groups are separated by 2 or 3 carbon atoms; di) about 33 to 67% of the reaction product of: (1) about one NCO equivalent of a n-functional isocyanate compound, wherein n is a number ranging from 2 to about 5, and (2) one nnol of a compound containing 1 to 18 carbon atoms and an individual functional group capable of reacting with an isocyanate; (b) about 0% to about 80% by weight of a polyol selected from the group consisting of polyester polyols, polyacrylate polyols and alkyd polyols; and (c) from 10% to about 50% by weight of a partially alkylated amine ring resin which acts as an interlayer for components (a) and (b); with the above weight percentages being based on the total solids content. 51.- A composition of polyurethane polyol that comprises a blend of (A) approximately 33-67% of the reaction product characterized by the structure: 0 CH0-R2-0-C-NH-3 n ~ -Rl, and (B) about 33-67% of the reaction product characterized by the structure 0 wherein R 1 is a portion of an n-functional polusocyanate, with n ranging from 2 to about 5, from which the isocyanate groups are subtracted, R 2 is the portion of a substantially monomeric diol selected from the group consisting of ß-diols and -t-diols from which the hydroxyl groups are subtracted, R3 is the portion of a monofunctional reactive compound of isocyanate group containing active hydrogen containing from 1 to 18 carbon atoms, of which active hydrogen is subtracted .