MXPA00002142A - Foaming urethane composition and methods of using such compositions - Google Patents

Abstract

This invention relates to a foamable composition comprising at least two parts. More specifically, the first part comprises at least one polyol, at least one gelling agent, and at least one blowing agent wherein the first part comprises an effective amount of hydrophobic ingredients and a second part comprising at least one isocyanate. A foam mass can be prepared by a method of combining a polyol component with an isocyanate component substantially free of urethane prepolymer and applying the mixture to a void or substrate. The invention also relates to methods of using certain polyurethane compositions in the repair of surface defects or for the reinforcement of structural members such as spike holes left after spike removal from railroad ties during road bed maintenance or repair. This invention further relates to a method of foaming certain polyurethane compositions in the presence of water.

Description

STRUCTURAL COMPOSITION OF URETANE AND M ALL FOR USING SUCH COMPOSITIONS DESCRIPTION OF THE INVENTION This application is a Continuation in Part of the North American Application Serial No. 60/058981, filed September 10, 1997, the application of which is incorporated herein by reference . This invention relates to a foamable composition comprising at least two parts. More specifically, the first part comprises at least one polyol, at least one gelling agent, and at least one blowing agent wherein the first part comprises an effective amount of hydrophobic ingredients and a second part comprises at least one isocyanate . A foam mass can be prepared by a method for combining the polyol component with an isocyanate component substantially free of urethane prepolymer and applying the mixture to a vacuum or substrate. The invention also relates to methods for using certain polyurethane compositions in the repair of surface defects or for the reinforcement of structural members such as spigot holes left after the removal of the spigot from railway sleepers during maintenance or repair. of the infrastructure. This invention also relates to a method for foaming certain polyurethane compositions in the presence of water.

The materials used to repair defects in structural members should have certain characteristics. The material should be easily applied and should form high strength joints for structural members made of various materials. Particularly, for exterior repairers, repair materials must be usable in many environments including environments that have extremes of heat and cold and that have the presence of substantial amounts of ambient water. A particularly important end use for such repair compositions in the re-cycling or re-use of railway sleepers. Typically, in the maintenance of the railroad track, the rails along with the plates of sleepers and spikes, are removed from the railway sleepers that remain in the infrastructure. If a new rail is to be nailed to the old rail, it is critical that the dowel holes of the railroad crossbar be repaired beforehand to place the new rail. The presence of spike holes in an old cross member can cause problems because if a spigot is driven into a portion of the nearby cross member and the old spigot hole, the driving force of the spike can displace the spike from its intended location in a old hole, displacing the rail, the sleeper plate and the spigot. In the case where the spigot is driven into an incorrect location the substantial economic loss can result in the misaligned rail repair. If a misaligned rail is not repaired, the defect can cause derailment or other problems. In addition, spike holes can be the source of structural weakness in the sleeper, allowing water to enter the core of the sleeper accelerating degradation. Mechanical spike hole repair means have been suggested in the art. For example, Moses, US Patent No. 3,191,864, issued June 29, 1965, teaches a mechanical spigot bore insert used by first outer bore and old spigot bore, installing an insert and driving a new pin into the insert. Newman US Patent No. 3,716,608, issued February 13, 1973 teaches metal inserts that can be placed in drilled holes with a synthetic resin filler in which the pins can be driven. In another repair area. Tessenki, US Patents Nos. 4,070,201 and 4,152,185, issued on January 24, 1978 and May 1, 1979, respectively, teach a pin hole obstruction material of the railroad tie and method, using a substantial uniform mixture of a gradual abrasive material and a granular plastic material that is emptied into the hole left after the removal of the spike. The driving force of a spike in the abrasive material generates heat that plasticizes the material resulting in a firm bonding of the spike to the material. Mechanical and resin based filling methods tend to be time consuming, expensive and adapted to manual, without automatic application or installation. Rhodes et al., U.S. Patent No. 4,295,259, issued October 20, 1981, teaches a method for reusing the polyurethane foam injected into the holes. In Col. 4, lines 14-20, this reference states that "Chemical polyurethane manufacturers warn that both components are not allowed to fall below 55 ° F (13 ° C) at any time, including shipping and storage. Temperatures below 55 ° F (_3 ° C) apparently have a detrimental effect on the properties of the final product.The temperature control during the operation is used to regulate the viscosity. " Other polyurethane foam compositions have been suggested for other uses. For example, Maruyama et al., U.S. Patent No. 4,264,743, issued April 29, 1981, teaches a polyurethane foam sealing material of a polyisocyanate and a polyol component, a larger portion of the polyol component consisting of polyol derived from a dimer acid or castor oil, or a mixture thereof in the presence of a blowing agent, a foam stabilizer, a catalyst, and optionally, a lipophilic filler. As the catalyst, tertiary amines and organotin compounds are preferably used. The sealing materials are suitable for use in defense, fan, air conditioning joints and other parts in automobiles, as well as in ships, refrigerators and other assembly products. Barker et al., US Patent No. 5,124,367 issued June 23, 1992, teaches a flame retardant composition comprising a dispersion of solid fire retardant additive in a liquid reactive isocyanate compound, having a functionality of 2 to 8 and an equivalent weight average of about 31 to about 5000 and, as an anti-sedimentation agent, an effective amount of a fatty acid ester and / or amide such as castor oil. The anti-sedimentation agent is described in an amount of 0.05 to 5%. The composition is useful in the manufacture of flexible and rigid foams, resistant to flame. Grimm et al., U.S. Patent No. 5,470,515, issued November 28, 1995, teaches insulation of tubes by application of at least one layer of insulation and at least one outer surface layer by rotational molding. A rigid polyurethane foam is used as the insulation layer while a solid polyurethane is used as the surface layer. The rigid polyurethane foam is obtained by the reaction of a) an aromatic isocyanate with b) a polyol component yielding on average at least 3 hydrogen atoms of reactive isocyanate containing: 1. a polyether containing at least two hydroxyl groups and having a molecular weight of from 300 to 700, 2. an aliphatic, cycloaliphatic or aromatic polyamine having a molecular weight of from 32 to 1,000 as a crosslinking agent and a blowing agent, and optional ingredients. The solid polyurethane is obtained by the reaction of a) a finished NCO prepolymer having an NCO content of 5 to 20% obtained by the reaction of 1) 4,4-diphenylmethane diisocyanate, optionally mixed with 2,4 'isomers and 2.2 'and 0 to 30"by weight of high functionality components with; 2) polyethers containing 2 to 4 OH groups having a molecular weight of 1,000 to 6,000 to which up to 30% by weight of a hydrophobicizing agent, preferably castor oil, has been optionally added with b) a polyol component containing 1) a polyether containing 2 to 4 hydrogen atoms of reactive isocyanate and having a molecular weight of 1,000 to 6,000; 2) 5 to 35 ?. by weight of an aromatic diamine having a molecular weight of 122 to 400; 3) 0 to 5% by weight of an aliphatic or cycloaliphatic diamine having a molecular weight of 60 to 4000; 4) 0 to 30% of a hydrophobicizing agent and 5) optional auxiliaries and additives. Doyle et al., US Patent No. 4,248,811, issued February 3, 1981 teaches equipment and formulations for filling ordinary pneumatic sleepers with a polyurethane foam. A composition was exemplified where component A contains 5 equivalents, 665 pounds of 4,4'-diphenylmethane diisocyanate (MDI), 1 equivalent, 1250 pounds of hydroxy-terminated polybutadiene, and component B contains 1.1 equivalents, 1375 pounds of finished hydroxy polybutadiene, 1 equivalent of 340 pounds of castor oil, 1 equivalent of 80.1 pounds of 1,4-butanediol, 35 pounds of silicone surfactant, 4.5 pounds of tertiary amine horseman., 4.5 pounds of charged octoate and 30.0 pounds of oily resin fatty acid. Castor oil is added to complete the polybutadiene. The use of polyurethane foam in filler pin holes in used railway sleepers can present significant problems. The polyurethane foam compositions do not appear to adhere to a pin hole with sufficient adhesion to prevent accidental removal of the foam repair mass during repair and subsequent mechanical installation of the rail. In addition, urethane foams of the prior art tend to foam uncontrollably in the presence of substantial environmental humidity. Since moisture tends to accelerate the foaming properties of the urethane composition, the presence of water can cause rapid cellular expansion resulting in a mass of low strength, low density foam that can result in the formation of an incomplete repair or unreliable structural members. Morin, US Patent No. 4,661,532, issued April 18, 1987, teaches that mineral tar containing foamable urethane compositions and a method for repairing defects in structural components. A composition of two hydrophobic urethane foaming packets is described in the first package comprising a polyol made hydrophobic by the presence of an effective amount of a mineral tar or mineral tar pitch composition. Although the use of mineral tar significantly improves the problems associated with the adhesion and uncontrolled foaming of the polyurethane composition in the presence of substantial moisture, this approach has had limited commercial success due to the safety hazards of the worker since the mineral tar has been identified as a carcinogen. Therefore, the products were developed in which the mineral tar was replaced with a mixture of hydrophobic polyols comprising approximately 20 '. by weight of castor oil present in the polyol component. The viscosity of each part of such products is approximately 2,000 cPs at 77 ° F (25 ° C), but increases to approximately 50,000 cPs at 50 ° F (10 ° C), and in excess of 100,000 cPs at 40 ° F (4 ° C). Therefore, mineral tar containing compositions as well as non-carcinogenic modifications were found to be difficult to apply by conventional application equipment without the addition of heat. The recommended application temperature for such products ranges from approximately 130 ° F (54 ° C) to approximately 140 ° F (60 ° C). As the railroad repair follows a task throughout the year, instead of seasonal during the hot months of the year, the difficulty in the application becomes very problematic. Accordingly, a substantial need exists in the art for foamable compositions employing non-carcinogenic ingredients that can be used to repair surface defects in structural components such as railway sleepers to provide a repair mass having strong adhesion to the structural member of the substrate, which can be used in the presence of substantial amounts of ambient water and can be used in automatic application equipment at all temperatures. The Applicant has discovered a polyurethane composition that can be foamed in the presence of high concentrations of water. The composition of the present invention creates viscosity and enough sufficiently fast gels that can be foamed under water, while still maintaining excellent foam quality such as foam structure, strength and density. The foamable polyurethane compositions exhibit excellent adhesion to a variety of substrates including plastic, metal and wood, even when such substrates are wet. The present invention is a foamable composition having at least two parts comprising: a) a part A comprising at least one polyol, at least one gelling agent, and at least one blowing agent; wherein part A comprises an effective amount of hydrophobic ingredients; and b) a part B comprising at least one isocyanate. Preferably, the polyol is a castor oil and the gelling agent is a polyamine. In addition, the polyurethane composition preferably further comprises at least one plasticizer in part A and / or part B to reduce the viscosity as well as certain catalysts to achieve correct reaction ratios after mixing and application. Advantageously, each part exhibits a low viscosity over a wide temperature range, having a Brookfield viscosity of less than about 10,000 cPs at temperatures ranging from about 20 ° F. (-7 ° C) at 40 ° F (4 ° C). The invention further relates to a foam mass prepared by a method of: a) forming a mixture comprising a polyol component comprising at least one polyol, at least one gelling agent, and at least one blowing agent and an isocyanate component substantially free of prepolymer; b) apply the mixture to a vacuum or substrate. In this embodiment, the isocyanate component is preferably substantially free of isocyanate reagents to prevent the formation of a prepolymer which tends to substantially increase the viscosity of the isocyanate component. In a preferred embodiment, the present invention further relates to a foamable composition comprising: a) a part A comprising an amount of 30 'by weight of more than at least one hydrophobic polyol, at least one gelling agent, and at least one blowing agent; and b) a part B comprising at least one isocyanate. Another aspect of the present invention is to provide a polyurethane foam composition that is substantially unaffected by variations in the concentration of blowing agent such as water. This assumes that the moist and hydrophobic agent forms a balance to the outer surface of the foam by limiting the additional moisture taken. The invention further relates to a method for repair or reinforcement of a structural member comprising the steps of: a) providing a structural member having a vacuum; b) providing a foamable composition comprising a mixture of: i) a first part comprising at least one polyol, at least one gelling agent, and at least one blowing agent; wherein the first part comprises an effective amount of hydrophobic ingredients, and ii) a second part comprising at least one isocyanate; c) apply the mixture in vacuum. The composition initially has a relatively low viscosity to that of mixing. However, the applicant assumes that the thixotropic nature of the polyamine causes the composition to achieve the correct consistency for good repair or reinforcement at least immediately to the application. Since the consistency of the foam depends on a chemical reaction, the thixotropic nature of the composition, rather than merely the initial viscosity of the mixed parts, the composition can be easily applied at temperatures ranging from about -20 ° F. (-29 ° C) to approximately 120 ° F (49 ° C). The invention further relates to a method for foaming a polyurethane composition under water comprising the steps of: a) providing a submerged substrate in an aqueous environment; b) providing a polyurethane composition in an applicator having an outlet port, such composition comprising: i) a first part comprising at least one polyol, at least one gelling agent, and at least one blowing agent; wherein the first part comprises an effective amount of hydrophobic ingredients, and ii) a second part comprising at least one isocyanate; c) mixing the first and second parts to form a mixture; d) submerge the outlet port in the aqueous environment; e) apply the mixture to the substrate. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1, entitled "Ball Mili Demolition Test" describes the erosion and impact and abrasion resistance of Example 5 foamed at a density of approximately 18-22 pounds / ft3 (.29- .35 kg / dm3) ) an embodiment according to the present invention and Comparative Example A. The foaming compositions of the present invention exhibit a percentage loss of 20% less than Comparative A over the course of the representative time of an improved 50% loss of percentage at 96 hours and approximately 30% improved at 288 hours. Figure 2 depicts the storage modules (C), loss modules (G "), and tan delta of Example 5 foamed at a density of about 18-22 pounds / feet3 (.29-.35 kg / dm3). The G 'is related to the strength of the foam The foamable compositions of the present invention are rigid, which have a G 'greater than 1 X 10 { 'dynes / cm' during a temperature that varies from 20 ° C to 100 ° C. The term "polyurethane foam" as described herein is defined as a polymer containing at least two urethane groups including ureas, isocyanurates and biurets. More specifically, the foam of the present invention is a polyurethane-urea foam. "Hydrophobic" refers to those ingredients that have a water concentration at room temperature of less than 1% after being conditioned for 14 days at 100 ° F (38 ° C) and 95% relative humidity in a cylindrical container about 4 cm in height having an inner diameter of approximately 3 cm. The foamable composition of the present invention comprises at least two parts. By mixing the two parts and exposing the mixture at ambient pressures and temperatures, the composition foams. Generally, each part is provided separately and mixed immediately before the application. However, the invention also contemplates encapsulated ingredients, particularly encapsulated catalysts and / or isocyanates and / or gelling agents. In these embodiments, the composition can be provided as a single mixture. The first part, part A, or polyol component comprises at least one polyol, at least one gelling agent, and at least one blowing agent. The polyol component comprises an effective amount of hydrophobic ingredients such that the density of the foam differs by not more than 10 pounds / foot3 (.16 kg / dm3), preferably by no more than 5 pounds / foot3 (.08 kg / dm3) when foaming in the presence of water compared to being foamed dry. The amount of hydrophobic ingredients present in the polyol component is typically at least 20% by weight, preferably about 30% by weight, or more, more preferably about 40% by weight or more, even more preferably about 50% by weight. weight or more and more preferably more than 60% by weight. The applicant assumes that the relatively high concentration of hydrophobic ingredients in combination with the formation of a gel is contributing to the characteristic that the composition is not essentially affected by high concentrations of water. In the absence of a gelling agent, there tends to be a substantial difference in foam density achieved to dry conditions in contrast to wet conditions. Since water is a common blowing agent, the expansion ratio of the foamable compositions is typically directly related to the concentration of water present. Therefore, as the concentration of water increases, the polyurethane compositions in the absence of gelling agent tend to froth, instead of producing a consistent foam. The first part or part A of the foamable composition of the present invention comprises at least one polyol. For the preparation of polyol rigid foams (es), in general, it has a molecular weight of 50 to 4000, a functionality of 2-8 and a hydroxyl number, as determined by ASTM designation E-222-67 (Method B) ), in a range from about 14 to about 180Q, preferably from about 50 to about 500, and more preferably from about 100 to 200. The polyols and methods for their preparation are known. For the purpose of the present invention, a "polyol" is an ingredient having at least two active hydrogen atoms. The term "active hydrogen atom" refers to hydrogens that exhibit activity according to the Zerewitnoff test as described by Kohlerin, Journal of the American Chemical Society, Vol. 49, pp. 31-81 (1927). Useful polyols include polyethers, polyesteramides, polythioethers, polycarbonates, polyacetals, polyolefins, polysiloxanes and especially, Preferred polyols are hydrophobic including various grades of castor oil, ricinoleate polyols (highly refined castor oil) and derivatives thereof. Casserole oil also known as castor oil, is a triglyceride (ester) or fatty acids derived from the seed of the castor plant. Approximately 90% of the contained fatty acid is ricinoleic acid, a carbon acid 18, which has a double bond in the 9-10 position and a hydroxyl group in the 12th carbon. The rest of the castor oil is made of dihydroxystearic acid (.11), palmitic acid (1%), stearic acid (1%), oleic acid (3%), linoleic acid (4.2%), linolenic acid (.3%) ) and eicosanoic acid (.3%). Castor oil is available in a variety of grades from various suppliers. Other suitable polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol and mixtures thereof. The polyol is present in the first part or part A at a concentration ranging from about 5% by weight to about 95% by weight, preferably from about 10% by weight to about 80% by weight, most preferably about 20% by weight. % to about 80% by weight, even more preferably from about 40%, to about 0%, and most preferably from about 50% to about 80%, based on the total weight of the first part (part A) . It is a conjecture that low molecular weight polyols act as hard segments with polyurethane foam to increase stiffness. Alternatively, in addition to the low molecular weight polyols, high molecular weight polyols can also be used. Preferably, the polyol component comprises at least one short chain extended to increase stiffness. Short chain extenders are known in the art and include such polyols as ethylene glycol, dipropylene glycol and glycerin. In addition to, or in the alternative, high functional polyols having more than two hydroxyl groups per molecule can be employed in the part A component. Examples include glycerol, trimethylolpropane, 1,2,4-butantriol, 1,2 , 6-hexantriol and mixtures thereof. The high functional polyol may be present in the part A component in a range from about 5% by weight to about 20% by weight, and preferably about 10%. by weight to approximately 15% by weight based on total weight. Such materials react to provide rigid polyurethane foams having increased crosslink density. The first part (part A) of the composition of the present invention comprises at least one gelling agent. Any material that thickened the mixture, particularly at the interface contacting the substrate or water, to the extent that the isocyanate component is substantially prevented from reacting with excess ambient water is suitable for use as the gelling agent. Suitable gelling agents include peroxides, polyamides, and preferably polyamines. The polyamine is typically a primary or secondary amine and has in the first part (part A) component in a range from about 0.1% by weight to about 5% by weight, and preferably from about 0.5% by weight to about 2 to 3. % by weight based on the total weight of the polyol component. By mixing the polyol and isocyanate component, the gel composition typically for 1 minute, preferably in about 15 seconds or less, more preferably about 10 seconds or less, and more preferably about 5 seconds or less when mixed and apply by mixing meter application equipment. It is an assumption that polyamine acts as a chemical thixotropic to provide an urgent gel once the parts are mixed together. It is an additional assumption that the urgent formation of a gel increases the sealing characteristics of the foam. For example, vacant spigot holes often create gaps with a rail tie that can pass completely through the tie. As the inventive foamable composition is injected into the hole, the thixotropic gelling action provided by the polyamine allows the composition to more easily adhere to the inner surface of the hole. Thus, the composition foams within the vacuum to properly seal the hole. In the absence of the polyamine, the composition is more similar to the flow through the hole and / or break and provide an inadequate seal once foamed. Alternatively, in the absence of a gelling agent, the ingredients for each part can be selected such that the composition is suitable and sufficiently high in viscosity upon mixing without a thixotropic ingredient. However, it is much less desirable since the high initial viscosity causes the composition to be more difficult to apply consistently, particularly at low application temperatures. The structure or type of polyamine is selected at the base of the desired gel ratio. In general, the polyamine can be monomeric or polymeric, having a functionality of 2 or more. The linear aliphatic polyamines result in the fastest gelation ratio, while the cycloaliphatic polyamines produce a slightly slow gel ratio and still slightly slow aromatic polyamines. However, although the relatively "slow" aromatic polyamine results in the formation of a gel in less than about 15 seconds when applied by a mixing measuring device. For automatic application means, aliphatic and cisloaliphatic polyamines are preferred while aromatic polyamines are preferred for manual application equipment. Preferably, the molecular weight of the polyamine ranges from about 100 grams / moles to about 400 grams / moles. Examples of useful polyamines include ethylenediamine, tolylenediamine, diaminodiphenylmethane and polymethylene polyphenylene; polyamides and aminoalcohols, for example ethanolamine and diethanolamine. Preferred aromatic amines include 4,4'-diamino-diphenylmethane, 3,5-diethyl-2,4-tolylenediamine (DETDA), and Hardener HY-450, a 4, '-methylenebis (2-ethylbenzamine) available from Ciba Geigy. For cycloaliphatic amines of fast gel ratios such as AMICURE PACM, a bis- (p-aminocyclohexyl) methane, available from Air Products and Chemicals & Inc, are preferred, while linear aliphatic amines such as JEFFAMINE, available from Hunstman Chemical Corp (Houston, TX) are assumptions of gel rapidity. The foamable composition as a whole necessarily comprises -at least 20% by weight of hydrophobic ingredients. Preferably, the amount of hydrophobic ingredients is greater than 30%, more preferably greater than 40:., Even more preferably greater than 50% and more preferably about 60% by weight or more. In embodiments wherein the hydrophobic ingredients are mainly contributed by the polyol portion, the first part (part A) will comprise at least about 50% by weight, preferably at least about 60% by weight, and most preferably about 70% to about 95% by weight of hydrophobic ingredients, based on the total weight of part A. The polyol itself may be the only hydrophobic component, as in the case where relatively high concentrations of castor oil are employed and / or additional hydrophobic ingredients can be used. A preferred hydrophobic additive is a monofunctional alcohol such as dinonylphenol. Additional hydrophobic agents include fuel oils such as fuel diesel, paraffin waxes, animal or vegetable waxes, and the like. The high concentration of hydrophobic ingredients in combination with the gelling agent allows the foamable composition to be injected in an aqueous environment. For example, vacant tenon holes often contain standing water that increases foaming and decreases the foam density that can be detrimental. Foamable compositions having increased hydrophobicity are less similar to trapped emulsion and / or water which may result in reduction of foam stiffness and adhesion characteristics. The foamable composition of the present invention comprises at least one blowing agent typically present in the first part of the component (part A). The preferred blowing agent is water that is added to an amount ranging from about 0.5% by weight to about 1% by weight, and preferably from about 0.15% by weight to about 0.5%. by weight, based on the total weight of Part A. In many cases, the polyol component and / or hydrophobic ingredients containing a small concentration of residual moisture or water at a concentration sufficient to act as a blowing agent. Accordingly, the blowing agent can inherently present and thus need not be separately added. The foamable composition of the present invention comprises at least one isocyanate, used in the second part or the part B component. Any of a wide variety of organic polyisocyanate compositions can be employed in the isocyanate component, including monomeric polyisocyanates and / or polymeric which may be linear, branched, cyclic aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, terminated isocyanate prepolymers, isocyanurates and mixtures thereof. Representative examples include 2,4-toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), m-phenylene diisocyanate, 4-chloroyl, 3-phenylene, diisocyanate, 4'-biphenyl, diisocyanate, 1, 5-naphthalene, 1,4-tetramethylene diisocyanate, 6-hexamethylene diisocyanate, 1, 10-decamethylene diisocyanate, 1, 10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate) and others. In addition, the isocyanate compound may contain other substituents that do not substantially lower the natural reagents of the isocyanate groups. It is preferred to use a mixture of two or more isocyanates wherein at least one of the isocyanates is aromatic. Aromatic diisocyanates, those having at least two isocyanate groups directly attached to an aromatic ring, react in the urethane reaction more rapidly with polyols than the aliphatic isocyanates. Preferred isocyanates are polymeric MDIs including polymethylene polyphenyl isocyanates containing 4, '-methylene bisphenyl isocyanate commercially available from The Dow Chemical Company, Midland, MI as PAPI 2027, PAPI 2020 and PAPI 2901; from ICI such as Rubinate M, Rubinate 9257, and Rubinate 9258; and from Bayer as Modur MR, MR-200 and MRS-10. Preferably, the isocyanate component is substantially free of isocyanate reagents to prevent the formation of a prepolymer which tends to substantially increase the viscosity of the isocyanate component. The isocyanate is present in the second part of the component (part B) in a range above about 100% by weight. Preferably, the isocyanate is employed at a concentration of about 85% by weight to about 99% by weight, and most preferably about 94;. by weight to about 97% by weight based on the total weight of part B. At least one plasticizer is preferably used in the polyol component (part A) and / or isocyanate component (part B) to improve the flow characteristics by reducing the viscosity. Suitable plasticizers include polymer resins, elastomers, waxes, oils and mixtures thereof. Specific examples include esters of phthatate, alkyl phosphates, polyphenyls, di compounds and triphenyl as well as partially hydrogenated versions, aromatic oils, chlorinated waxes or paraffins, adipate esters, synthetic rubber polymer, natural oils, rosin and resin derivatives of turpentine and polysulfide rubber. A preferred plasticizer is Eastman TXIB Plasticizer (Eastman Chemical Company, Kingsport, TN), a diisobutyrate plasticizer of 2, 2, 4-trimethyl-l, 3-pentanediol. The plasticizer may be present in part in a range from about 1% by weight to about 25% by weight, and preferably from about 5% by weight to about 10% by weight, with respect to the total weight of each part. The addition of a plasticizer to the components of part A and / or part B is preferred to improve the characteristics of the tire during the repair operation of railway sleepers. Preferably the ingredients are selected to lower the crystallization temperature of each component to improve the freeze-thaw stability. For example, the railroad industry repairs rails all year round and fluctuations in temperature, especially during low temperatures, prefer that each part flows without additional heat at reduced temperatures. Additionally, the isocyanate used in the component of part B may tend to crystallize under cold temperatures so that the addition of a plasticizer allows for enhanced processing characteristics. The viscosity of each part of the foamable composition of the present invention is preferably as low as possible at as low a temperature as possible.

Accordingly, each part of the foamable composition of the present invention has a viscosity (24 hours) of less than about 10,000 '-Ps, preferably less than about 5,000 cPs, more preferably less than about 2,000 cPs, at least preferably less than about 1,000 cPs at a temperature of about 50 ° F (10 ° C) or less. Preferably, each part of the foamable composition exhibits the desired viscosity at a temperature of less than about 40 ° F (4 ° C), more preferably to less than about 30 ° F (-1 ° C) and more preferably to about 20 ° F (-7 ° C) or less. The inventive foamable composition of the present invention is preferably applied at a temperature at which the viscosity is about 1,000 cPs or less. Due to the relatively flat viscosity curve, the composition of the present invention are more amicably used, being able to be applied over a relatively wide temperature range. For best results, the composition is applied at a temperature of about 70 ° F (21 ° C) to about 100 ° F (38 ° C), with about 90 ° F (32 ° C) being more preferred. To be applied over a wide temperature range and without requiring any special handling, it is preferred that each part of the foamable composition of the present invention exhibit freeze-thaw stability meaning that the freezing and thawing of the components has no substantial detrimental effect in the processability nor the properties of the resulting foam. Preferably, each part is a stable liquid at temperatures below 30 ° F (-1 ° C), more preferably below 10 ° F (-12 ° C), even more preferably below 0 ° F (- 18 ° C), still more preferably about -10 ° F (-23 ° C) or less and more preferably at about -20 ° F (-29 ° C) or less. The reaction ratio of the composition of the invention after mixing the polyol component with the isocyanate component can be accelerated by the incorporation of effective amounts of catalysts to promote the reaction of the active hydrogen atom / isocyanate. Suitable catalysts are those which are known to increase the polyol / isocyanate reaction. Preferably, a catalyst combination is employed to accelerate the formation of urethane bonds as well as isocyanurate bonds. The applicants assume that the finished foam is comprised of a variety of bonds including isocyanurate, biuret and urea bonds instead of predominantly urethane bonds. The catalysts are typically employed in amounts ranging from about 0.1% by weight to about 5% by weight, and preferably from about 0.3% by weight to about 3% by weight, based on the total weight of part A. The catalysts they include organic amine compounds and organometallic compounds and mixtures thereof which are typically present in the polyol component (Part A) for stability purposes. In addition, the catalyst can be used in combination with various accelerators and / or curing agents such as Lewis Base catalysts including ANCAMINE K.54 (Pacific Anchor Chemical Corporation, Los Angeles, CA), a tris- (dimethylaminomethyl) phenol. The amine-based catalysts differ from the polyamine gelling agent, with respect to the number of reactive sites present as well as with respect to the concentration employed. While the amine-based catalysts are typically tertiary amines, the polyamine gelling agent is typically a primary or secondary amine. Therefore, the polyamine gelling agents are a reagent that is incorporated into the foam instead of aggregate for the purpose of propagating the reaction, as in the case of the catalysts. Specific examples of catalysts useful for promoting the urethane reaction include dibutyltin dilaurate, stannous octoate, aliphatic and tertiary alicyclic tertiary amines, ~ including triethylamine, triethanolamine, tri-n-butylamine, triethylenediamine, alkylmorpholene, etc. Complex mixtures of such catalysts and modified forms can also be employed. For the promotion of the isocyanurate reaction, preferably specific types of catalysts are used such as Polycat 41 (N, N, N ', N', N ", N" -hexamethyl-l, 3,5-triazine 1,3, 5 (2H, 4H, 6H tripropanamine), Polycat 43 (a proprietary tertiary amine) and several catalysts based on potassium salts of organic acids including DABCO T-45 (potassium octanoate in dipropylene glycol (DPB) (60/40), DABCO K-15 (potassium octonate in DPG (70/30), METACURE T-120 (organotin catalyst (17.5% tin) exhibiting high catalytic activity), and Polycat 46 (potassium acetate in ethylene glycol). DABCO are supplied by Air Products &; Chemicals, Inc. (Allento n, PA). More preferred are the combinations of the isocyanurate reaction catalysts. For example, a slowly reacting trimer catalyst such as DABCO TMR-2 and DABCO TMR-3 (quaternary ammonium salts) and DABCO TMR-30 (2,4,6-tris (dimethylamino-methyl) phenol) can be employed and preferably in combination with strong trimer catalysts. Alternatively, combinations of strong trimer catalysts and a small amount of urethane catalysts, such as DABCO 33 LV (triethylenediamine in DPG (33/67) and a metal-based catalyst similar to DABCO T-12 (dibutyltin dilaurate) can Also, these catalyst systems are preferred to minimize initial foaming as described in U.S. Patent No. 5,556,934, issued September 17, 1996, incorporated herein by reference.Other characteristics of the polyurethane foam can be modified with additives commonly used in polyurethane foam compositions including fillers and extenders such as ultraviolet (UV) light stabilizers, antioxidants, fungicides, bactericides, surfactants, dyes and mixtures thereof The polyurethane composition can be made according to manufacturing methods The polyol component and the isocyanate component are individually Prepared using commonly available blends and mixing techniques. The two-part inventive foamable composition is most effectively used to mix and apply the composition using collision equipment that mixes the packages at an appropriate ratio. In such processes, the components are mixed-measured together with a ratio of active hydrogen atoms (part A) to the isocyanate group (part B) in a range from about 1: 1 to about 1: 4, and preferably at a ratio of approximately 1: 3. Therefore, excess isocyanate is preferred. In the repair of a railway sleeper, the composition of the invention is preferably preheated to a temperature ranging from about 80 ° F (27 ° C) to about 120 ° F (49 ° C) and is applied to the spike hole using an automatic mixer and application unit that is part of a one-lane repair process that can remove the spike and shank plate, lift or replace the rail sleeper, and repair the spigot holes using the polyurethane composition of the invention, followed by the replacement of the spigot plate and the rail and the reespigado assembly together. The inventive composition of the present invention is also useful for reinforcing composite structural members including building materials such as doors, windows, furniture and cabinets and for repairing walls and concrete. The composition can be used to fill any unintentional voids, particularly to increase strength. The structural components are formed from a variety of materials such as maceration, plastic, concrete and others, while the defect to be repaired or reinforced can appear as cuts, holes, deep holes, cracks, etc. The foamable composition of the present invention is supposed to be useful for other applications where a foam is formed in an aqueous environment is of importance as for example in damping dam repair. A foam mass can be prepared by combining the polyol component, being substantially free of urethane prepolymer with an isocyanate component. The foam can be an open or closed cell that exhibits a uniform cell structure that can collapse on the surface to form a skin. In addition, the resulting foam, particularly for use in railway repair, can be characterized as follows: Preferred Useful Most Preferred Foam Density > 5 pounds / foot3 > 10 pounds / foot3 15-30 + pounds / foot3 Resistance (G ') > 1X107 dynes / cm2 > 1X107 dynes / cm2 > 1X108 dyne / cm2 Demolition Test < 40% loss < 30% loss < 20% loss (96 hours) The density of foam does not change substantially when foaming in humid environments compared to dry. Preferably, the difference in foam density is no greater than about 10 pounds / ft3 (.16 kg / dm3) more preferably not more than about 5 pounds / ft "(.08 kg / dm3) and more preferably a difference of no more than about 3 pounds / ft3 (.05 kq / dm '') Test Methods Fusion Viscosity The melt viscosity is determined according to the following procedure using a Brookfield Laboratories DVII + Viscometer The pivot used is an RV Spindle Set, suitable for measuring viscosities in the range of 10 to 100,000 centipoise.The viscometer device is lowered and the pivot submerged in the sample tested.The descent is continued until the pivot line is on the sample.The viscometer is returned to the , and set at a cut ratio that leads to a torque indicated in the range of 30 to 60 percent.The indications are taken each half a minute for approximately 2 minutes, or up to the values e stabilized, whose final indication is recorded. The initial viscosity is tested immediately after the preparation of the polyol or isocyanate component and is often considerably higher than the viscosity after 24 hours. The viscosity after 24 hours is representative of the viscosity during use. Therefore, the reference to viscosity refers to the viscosity 24 hours unless otherwise stated. Density or Drying Density is determined either by a method for displacing water or by foaming the composition directly in an empty container of a known mass and volume. Moisture Density is determined by the same method as the drying density except the compositions, if it is foamed directly in a water bath or water filled container. Dynamic Mechanical Analysis A deflection temperature was conducted in accordance with ASTM-D4440-93 in the foam using geometric xectangular torsion and a frequency of radians / seconds and a temperature ramp of 2 ° C / minute.

The storage modules (G '), loss modules (C) and tan delta were plotted over the desired temperature range. Demolition Test of Ball Mill The test is used to determine the resistance to erosion by impact and abrasion. The results are expressed as a percentage loss after a period of time, typically after 100 hours. A ball mill of the type commonly used to grind pigments is employed having an external dimension of approximately 5.5"± 2" in height having a diameter of 5.5"± 1". The ball mill contains thirty-three rounded cylindrical balls approximately 3/4"± 1/4" in height and 3/4"± 1/4" in diameter. Ten plugs of the sample to be tested are prepared which are similar in size to the balls in the ball mill. The total weight of the sample caps is recorded as close as 0.1 grams. The balls of the clean ball mill are previously sprinkled with small pieces of the sample to be tested for at least 2 hours. Empty the ball mill out of all the dust that can be easily moved out. Place the plugs lengthwise with powdered balls in the ball mill. Seal and roll the ball mill on a paint roller or similar device at 50 rpm ± 5 rpm. Every 12-24 hours, stop the ball mill, remove the plugs, blow any dust that can be removed with compressed air and weigh the samples as close as 0.1 gram. Determine the percentage loss by subtracting the weight eroded from the initial weight and dividing the difference by the initial weight X 100%.

The following examples were prepared according to the following general procedure: The "polyol", part A or first part component is prepared by adding all the ingredients to a Cowles dissolver at room temperature and stirring until the mixture is completely homogeneous. For examples that include small concentrations of catalysts or other ingredients, it is also advantageous to make a premix of the polyamine and the ingredient employed in small concentrations. If a single isocyanate is used without any additional ingredients, no additional preparation is required. In the examples when the "iso", part B or second part also comprises a plasticizer mixed or reacted with the isocyanate, the ingredients are added to a Cowles dissolver and stirred until the mixture is completely homogeneous. Each part is packaged separately in an appropriate manner. Tables I, II and III represent several "polyol" or part A component while Table IV represents several "iso" or part B components. Castor oil, finished hydroxyl polybutadiene resin, and dinonylphenol a monofunctional alcohol are hydrophobic ingredients, while Eastman TXIB polyether polyols, short chain extenders, isocyanates and plasticizers are not hydrophobic.

The present invention encompasses all possible combinations of polyol component and isocyanate components according to the claims. The following observations and, or physical properties were obtained at the combination of the polyol component and isocyanate component at a mixing ratio of 1 to 1. Example 1 Poiyol 1 was reacted with Iso B resulting in a foam having a wet density 120 ° F (49 ° C) of 16 pounds / foot3 (.26 kg / dm3) and a dry density of 27 pounds / foot3 (.43 kg / dm3). E p e 2 Poiyol 6 was reacted with Papi isocyanate 2027 not compound producing a foam. Example 3 Poiyol 8 was reacted with Iso H resulting in a gel time of 15 seconds and a foam density of 24 pounds / foot3 (.37 kg / dm3). Example 4 Poiyol 9 was reacted with Iso K and placed in a mold. The samples were placed in an oven during 2 hours at 158 ° F (70 ° C). The sample was then tested by Azod impact resulting in an average resistance of 0.228 feet pounds. (- empty space 0.045) = 0.183 feet pounds. Example 5 Poiyol 11 was modified by decreasing the castor oil content by 1% by weight, increasing the Dabco T-120 catalyst to 1.2% by weight, increasing the Ancamine K-54 to 0.4% by weight and replacing the aromatic amine HY -450 with Amicure PACM. The polyol has an initial viscosity of 1200 cPs, and a viscosity of 24 hours of 250 cP. The polyol was reacted with Iso K to produce a foam. The viscosity profile for the polyol component and iso component was as follows: Part A / Polyol Part B / lso 20 ° F (-7 ° C) 6000 cPs 10,000 cPs 30 ° F (-1 ° C) 2500 cPs 5000 cPs 40 ° F (4 ° C) 2000 cPs 2500 cPs 50 ° F (10 ° C) 1000 cPs 1250 cPs 60 ° F (16 ° C) 500 cPs 500 cPs Example 6 Poiyol 14 was reacted with Iso A to produce a foam that has an initial wet density of 24. 1 pound / foot (.386 kg / dm3 and a dry density of 28. 1 pound / foot3 (.450 kg / dm3). The next day another foam sample was made in which the wet density was 21.1 pounds / foot3 (.338 kg / dm3) and the dry density was 24.4 pounds / foot3 (.390 kg / dm3). The viscosity of the Poiyol component was 310 cPs initially and stable at 260 cPs after 1 and 2 days. The moisture content of the Poiyol component was measured to be 0.4319% initially, 0.4012% after 1 day and 0.3649% after 2 days. Example 7 Poiyol 14 was modified by replacing 3% by weight of castor oil with 3% by weight of ethylene glycol and reacted with Iso P_ paxa to produce an esum having an initial wet density of 14.5 pounds / ft3 (.232 kg / dm3 ) and a density dry of 21.9 pounds / foot (.350 kg / dmJ). The next day another foam sample was made having a wet density of 20.3 lbs / ft3 (.325 kg / dm3) and a dry density was 24.6 lbs / ft (.394 kg / dm3). The viscosity of the Iso component was 140 cPs initially and stable at 120 cPs after 1 and 2 days. Example 8 The modified Poiyol 14 of Example 7 was also made to react with Iso K by producing a foam having an initial wet density of 16.0 pounds / ft3 (.256 kg / dm3) and a dry density of 21.5 pounds / ft3 (.344 kg. / dm3). The next day another foam sample was made having a wet density of 16.7 pounds / foot3 (.267 kg / dm ') and a dry density of 22.5 pounds / foot3 (3.60 kg / dm3). The viscosity of the Poiyol component was consistent with Example 5 in which the viscosity decreased slightly during the first 24 hours and then stabilized accompanied by a tendency to decrease moisture content. Surprisingly, the change and moisture content had essentially no effect on foam density. Example 9 Poiyol 16, which has an initial viscosity of 270 cPs was reacted with Iso K to produce a foam. Example 10 Poiyol 22 was reacted with Iso K to produce a foam. Example 11 Poiyol 23 was reacted with Iso J resulting in a foam having a wet density of 18.2 lbs / ft3 (.291 kg / dm3) and a dry density of 29.0 lbs / ft3 (.464 kg / dm3). Examples 12-17 Poiyol 25, which has an initial viscosity of 2000 cPs was reacted with a non-compound Papi 2027 isocyanate resulting in a gel ratio of 20 seconds. The composition was used to foam under dry conditions with Tamper's available railway sleeper test equipment at a temperature ranging from room temperature (77 ° F (25 ° C)) to 125 ° F (52 ° C) under a Variety of test conditions as follows. Pressure Nozzle Temp. (° F) Density (pounds / ft3) standard # 20 115 (46 ° C) 24.9 (.398 kg / dm3) standard # 40 120 (49 ° C) 24.4 (.390 kg / dm3) standard # 20 125 (52 ° C) 26.6 (.426 kg / dm3) 40 lbs. # 30 120 (49 ° C) 25.6 (.410 kg / dm3) standard # 40 77 (25 ° C) 31.5 (.504 kg / dm3) 50 lbs. # 30 125 (52 ° C) 26.7 (.427 kg / dm3) standard # 30 125 (52 ° C) 25.5 (.408 kg / dm3) standard # 20 77 (25 ° C) 29.2 (.467 kg / dm3) standard # 15 77 (25 ° C) 32.4 (.518 kg / dm3) Foam density was found to be very consistent throughout this temperature range, particularly when the same nozzle size was used. Jeffamine 400 and 403 were individually added to Poiyol 25 and reacted with non-compound Papi 2027 isocyanate to decrease the gel ratio as follows: Jeffamine 0-400 Jeffamine T-403 1% by weight - 14 seconds 1% by weight - 13 seconds 2% - 13 seconds 2% - 12 seconds 3% - 11 seconds 3% - 11 seconds E xployment 18 Poiyol 29, which has an initial viscosity of 490 cPs, was reacted with Iso F, which has a viscosity initial of 470 cPs resulting in a foam that has a density of 13.5 lbs / ft3 (.216 kg / dm3) at 120 ° F (49 ° C) and a density of 12.7 lbs / ft3 (.203 kg / dm3) at a High temperature .

Example 19-21 Poiyol 31 was reacted with Iso A resulting in a foam having a wet density of 18.7 pounds / ft '(.299 kg / dm3) and a dry density of 23.3 pounds / ft3 (.373 kg / dm3) ). The viscosity of each component was measured as follows: Temp. (° F) Viscosity of Polyol Viscosity Iso 10 (-12 ° C) 3400 2800 30 (-1 ° C) 1700 990 40 (4 ° C) 1230 840 60 (16 ° C) 530 290 77 (25 ° C) 285 170 '90 (32 ° C) 190 105 0 (18 ° C) 5600 15 (-9 ° C) 2650 20 (-7 ° C) 1200 Poiyol 31 was combined with 1% by weight of zinc stearate and was made react with Iso A to produce a foam that has a dry density of 19.9 pounds / ft3 (.318 kg / dm3) and a wet density of 10.2 pounds / ft3 (.163 kg / dm3). Poiyol 31 was also reacted with Iso A at room temperature with 60 pounds of pressure resulting in a wet density of 16.5 pounds / foot3 (.264 kg / dm3) and a dry density of 19.2 pounds / foot3 (.307 kg / dm3). ).

Example 22 Poiyol 33, which has an initial viscosity of 1325 cPs was reacted with Iso K resulting in a gel time of 20 seconds and a density of approximately 25 pounds / ft3 (.40 kg / dm3). Example 23 Poiyol 36 was reacted with Iso H resulting in a gel time of 20 seconds and a foam having an initial density of 15.6 pounds / ft3 (.250 kg / dm3). Example 24 Poiyol 37 was reacted with non-composite Papi 2027 to produce a foam. Example 25 Poiyol 38, having an initial viscosity of 460 cPs at room temperature and a viscosity of 6400 cPs at 0 ° C, was reacted with Iso F, which has an initial viscosity at room temperature of 440 cPs and a viscosity of 5600 cps at 0 ° C. The composition had a gel time of 20 seconds at room temperature and 50 seconds at 0 ° C. Example 26 Poiyol 40 was reacted with Iso C resulting in a foam having a dry density at 130 ° F (54 ° C) of 20.8 pounds / ft3 (.333 kg / dm3). Example 27 Poiyol 40 was reacted with Iso F resulting in a foam having a dry density at 130 ° F (54 ° C) of 28.7 lb / ft3 (459 kg / dm3) and a wet density of 21.9 lb / ft3 (.350 kg / dm3). Example 28 Poiyol 43 was modified with the addition of 6.2% by weight of Voranol 230-660 and 2.0% by weight of AMICURE PACM gelling agent. The polyol component, which has an initial viscosity of 240 cPs, was reacted with Iso K to produce a less rigid foam. The dry density was 19.3 pounds / foot3 (.309 kg / dm3) while the wet density was 29.3 pounds / foot3 (.469 kg / dm3). Although this material is assumed to not have sufficient strength to be suitable for repair of railway sleepers, it should be suitable for other applications such as damming. lip Cp Table III.

TABLE IV

Claims (19)

1. CLAIMS 1. A foamable composition characterized in that it comprises at least two parts wherein the first part comprises at least one polyol, at least one gelling agent, and at least one blowing agent, wherein the first part comprises at least one hydrophobic ingredient present in an effective amount, and a second part comprising at least one isocyanate.
2. 2. The composition according to claim 1, further characterized in that it comprises a catalyst selected from the group consisting of urethane reaction catalysts, isocyanurate reaction catalysts, and mixtures thereof.
3. 3. The composition according to claim 1, characterized in that the amount of hydrophobic ingredient is at least about 20% by weight.
4. 4. The composition according to claim 1, characterized in that the difference between the wet foam density and the dry foam density is not more than 10 pounds / foot3 (.16 kg / dm3).
5. 5. The composition according to claim 1, characterized in that the polyol is hydrophobic.
6. 6. The composition according to claim 1, characterized in that the polyol is castor oil.
7. The composition according to claim 1, characterized in that the gelling agent is a polyamine.
8. 8. The composition according to claim 1, further characterized in that it comprises at least one plasticizer.
9. 9. The composition according to claim 1, characterized in that the first part is substantially free of prepolymer.
10. The composition according to claim 1, characterized in that the viscosity of each part is less than about 10,000 cPs at 50 ° F (10 ° C).
11. The composition according to claim 1, characterized in that the first part and the second part is a liquid at a temperature of less than about 30 ° F (-1 ° C).
12. The composition according to claim 1, characterized in that the composition is foamable under water and produces a foam having a density greater than about 5 pounds per cubic foot (.08 kg / drn).
13. 13. A method for repairing or reinforcing a structural member characterized in that it comprises the steps of: a) providing a structural member having a vacuum; b) providing a mixture of the foamable composition of claim 1; c) apply the mixture to vacuum. 1 .
14. The method according to claim 13, characterized in that the mixture is applied at temperatures ranging from about -20 ° F (-29 ° C) to about 120 ° F (49 ° C).
15. The method according to claim 13, characterized in that the structural member is selected from the group consisting of railway sleepers, building materials, window molding, furniture, wall and concrete elements.
16. 16. A method for foaming an underwater composition characterized in that it comprises the steps of: a) providing a submerged substrate in an aqueous environment; b) providing a mixture of the foamable composition of claim 1; c) immerse the outlet port in the aqueous environment; d) apply the mixture to the substrate.
17. 17. The foam mass prepared by a method for mixing the foamable composition according to claim 1 to an effective stoichiometric ratio.
18. 18. A foam mass having a loss of demolition of ball mill of less than 40: after 96 hours.
19. 19. The foam mass according to claim 18 characterized in that it has a G 'of more than 1 X 106 dynes / cm2.