MXPA97004376A - Initiating systems improved to curing compositions of vinyl ester and polyesterinsatur resins - Google Patents

Abstract

Thermosetting polymeric compositions comprising an ethylenically unsaturated polyester resin or vinyl ester, an organic peroxide initiator component, a decomposition promoter of said peroxide, and a resin polymerization inhibitor, wherein the inhibitor is present in an amount are described. with respect to the amount of the promoter present so that the gel time of the composition is independent of the amount of the promoter present. The observance of the indicated ratio between the promoter and the inhibitor provides the advantages of both components and also allows the operator to obtain characteristics and performance of healing as a unique function of the peroxide content of the composition.

Description

INITIATING SYSTEMS IMPROVED TO CURING COMPOSITIONS OF RESINS OF VINYL ESTER AND INSATURED POLYESTER The present invention relates to compositions containing unsaturated vinyl ester and / or polyester resins and / or which are capable of being cured by applying heat to the composition. More particularly, the present invention relates to improvements in the additive compounds within said compositions in order to provide satisfactory control of the curing conditions. Thermosetting resin compositions are known in general, in particular compositions in which the polymer comprises one or more polyesters and / or vinyl esters containing ethylenic unsaturation. Said compositions generally contain a greater amount of one or more thermosetting ethylenically unsaturated vinyl ester and / or polyester ester products, together with suitable additives. Healing takes place through the formation of bonds between the double ethylenic bonds in the molecules. Optionally it may include one or more entanglement agents and / or ethylenically unsaturated monomers, in which case the heat-induced cure proceeds by the reaction between the respective monomer (s) and / or entanglement agents with ethylenic double bonds of the polymer molecules. The healing of the unsaturated resin generally proceeds through mechanisms initiated with free radical. An initiator is added which is typically an organic peroxide, or a mixture of organic peroxides, which decompose to form a pair of portions each containing an odd oxygen atom that serves to initiate the reaction by which the resin is cured. polymeric Inhibitors have been used in this field to stabilize polymerizable monomers free from premature polymerization. The clearance of the free radical inhibitors could otherwise initiate the polymerization reaction. Therefore, the inhibitors extend the storage life and the curing time of the olefinic monomeric compositions and the products containing polymerized monomers. A fully satisfactory thermosetting vinyl ester or polyester composition must satisfy several different criteria. Satisfying all these criteria even to a reasonable degree is highly challenging, because none of the criteria are little conflicting with each other. For example, the thermal composition should be capable of being cured at a satisfactory rate and within a satisfactory period of time upon exposure to heat. On the other hand, the ability of the composition to begin curing requires a formulation so that the composition will not begin to heal before the user wishes to begin healing. In this way the use of additives could inhibit premature curing that would be expected to interfere with the healing principle and / or regimen when in fact healing would be desired. Similarly, it is often desirable for the thermosetting composition to exhibit time. of satisfactory gelling by which the length of time of the initial exposure is averaged with the conditions effective to initiate the cure, to the point at which the cure has proceeded sufficiently to form a visible gelation. However, it is also desirable that a thermosetting composition exhibits a reasonable crucible life; that is, in applications such as in the production of molded extruded forms or other forms wherein the compositions are exposed to conditions such that healing begins and requires the composition to undergo shaping operations and the like before being fully cured, is desirable that the cure proceeds at a sufficiently moderate rate so that extrusion or other desired processing can be effected on the total amount of the curable composition before the cure proceeds so far that subsequent extrusion or other forming operations can not be carried out. The success of these diverse objectives has conventionally required the use of promoters, or inhibitors, under conditions wherein the compromise is reached between the various desired characteristics of the composition, the performance of the cure, and the properties of the cured product. Even so, in carrying out this commitment it has required balancing several additives, their quantities, and the various variables that affect the performance of the cure. In this way the need remains in this field to identify the characteristics of the formulation by making it possible to perform to a more complete degree the advantages of the thermosetting vinyl ester and polyester compositions. There also remains a need in this field for compositions that achieve the desirable characteristics while simplifying the number of operation variables that the user must attend in order to obtain an optimal performance. The present invention achieves these objectives, and also achieves the various benefits and advantages described herein. The present invention is directed to a thermosetting polymeric composition comprising: (a) a resin selected from the group consisting of ethylenically unsaturated polyesters, vinyl esters and mixtures thereof; (b) an organic peroxide that is capable of decomposing by heating in free radicals that initiate curing by polymerization of said resin, whose peroxide exhibits a half-life temperature of ten hours greater than or equal to 30 ° C; and (c) a promoter for the decomposition of said peroxide and a cure inhibitor by polymerization of said resin, wherein said inhibitor is present in an amount with respect to the amount of said promoter present so that the gelification time of said said composition is independent of the amount of said promoter that is present. The present invention is further directed to a method of curing an ethylenically unsaturated resin, which comprises "heating said thermosetting polymeric composition to an effective temperature to cure the composition." Further, the present invention is directed to a mixture of a promoter for decomposition. of an organic peroxide initiator for an ethylenically unsaturated vinyl ester or polyester ester, with a polymerization inhibitor of the vinyl ester or the ethylenically unsaturated polyester, wherein the inhibitor is present in an amount with respect to the amount of the present promoter so that the gelling time of a thermosetting composition containing the mixture, the vinyl ester or the ethylenically unsaturated polyester, and an organic peroxide initiator for the polymerization of the polyester or the vinyl ester, is independent of the amount of the promoter that is present. modality The preferred embodiment of the present invention constitutes a two-component kit wherein one of the components is the aforementioned mixture of the promoter with the inhibitor and the other component is an organic peroxide that is capable of decomposing by heating in free radicals that initiate healing by polymerization of the vinyl ester or the ethylenically unsaturated polyester, wherein the peroxide exhibits a half-life of ten hours greater than or equal to 30 ° C. The heat curable polymers with which the present invention is particularly useful include those based on ethylenically unsaturated polyesters. Optionally, a copolymerizable vinyl or vinylidene monomer with the same may also be present, such as an entanglement agent containing one or two different ethylenically unsaturated sites.

Preferably, the ethylenically unsaturated polyester has one or more α, β-ethylenically unsaturated polyesters. The α, β-ethylenically unsaturated polyesters of this type are the usual polycondensation products of (i) at least one a, β-ethylenically unsaturated dicarboxylic acid containing generally 4 or 5 carbon atoms or their ester forming derivatives optionally in a mixture with up to 90 mol%, based on the unsaturated acid components, of at least one saturated aliphatic dicarboxylic acid containing from 4 to 10 carbon atoms or a cycloaliphatic dicarboxylic acid containing from 8 to 10 carbon atoms or their derivatives ester formers, with (ii) at least one polyhydroxy compound, more especially a dihydroxy compound, containing from 2 to 8 carbon atoms, ie polyesters of the type described, for example, by JR Lawrence in "Polyester Resins", Reinhold Publ. Corp., New York 1960, pages 18 and subsequent, and by Goerden-Vieweg in Kunststoff-Handbuch, Vol, HIV ("Polyester"), Carl Hanser Verlag, Munich 1973, pages 247 to 312. Examples of preferred unsaturated dicarboxylic acids or its derivatives are maleic acid or maleic acid anhydride and fumaric acid. However, it is also possible to use, for example, mesaconic acid, citraconic acid, itaconic acid or chloromaléic acid. Examples of the saturated aiiphatic dicarboxylic acids and cycloaliphatic dicarboxylic acids or their derivatives used according to the invention are italic acid, or italic acid anhydride, isophthalic acid, telephthalic acid, hexahydro or tetrahydrophthalic acid or their anhydrides, endomethylenetetrahydrophthalic acid or its anhydride, succinic acid or anhydride of succinic acid and chlorides and esters of succinic acid, adipic acid and sebacic acid. In order to produce substantially non-flammable resins, it is possible to use, for example, hexachloroemethylethylenetetrahydrophthalic acid (HET acid), tetrachlorophthalic acid or tetrabothotonic acid. Preferred polyesters contain residues of maleic acid from which they can be replaced from 25 to 75 mol% by residues of phthalic acid or isophthalic acid. Suitable dihydric alcohols are ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene glycol, dipropylene glycol, thiodiglycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 2,2-bis - (4-hydroxy-cyclohexyl) -propane, bis-alkoxylated bisphenol, bisphenol perhydro and others. It is preferred to employ ethylene glycol, 1,2-propanediol, diethylene glycol and dipropylene glycol. Further modifications are possible by incorporating up to 10 mol%, based on the alcohol or the acid component, of monohydric, trihydric and / or tetrahydric alcohols containing from 1 to 6 carbon atoms, such as methanol, ethanol, butanol, allyl alcohol , benzyl alcohol, cyclohexanol and tetrahydrofuran alcohol, trimethylolpropane, glycerol and pentaerythritol, and mono-, di- and tri-allyl ethers and benzyl ethers of trihydric and polyhydric alcohols containing from 3 to 6 carbon atoms according to the German Patent No. 1,024,654, and also by the incorporation of monobasic acids, such as benzoic acid or long chain unsaturated fatty acids, such as oleic acid, flaxseed oil fatty acid and ricinin fatty acid. The acid numbers of the polyesters usually reach between 1 and 100 and preferably between 20 and 70 their OH numbers between 10 and 150 and preferably between 20 and 100, and the molecular weights measured as average numbers (Mn) 'between approximately 500 and 5000 and preferably between approximately 1000 and 3000 (as measured by vapor pressure osmometry in dioxane and acetone, in the case of different values, the lower value is taken as the correct value). Suitable copolymerizable vinylidene and vmyl compounds are unsaturated compounds commonly found in polyester technology which preferably contain α-substituted vinyl groups or β-substituted allyl groups, preferably styrene, and also, for example, alkenylated or alkylated styrenes and alkylated styrenes; chlorinated nucleus, the alkyl groups contain from 1 to 4 carbon atoms, such as for example vinyltoluene, divinylbenzene, α-methylstyrene, tert-butystyrene or chlorine styren; vinyl esters of carboxylic acids with 2 to 6 carbon atoms, preferably vinyl acetate; vmilpyridine, vinylnaphthalene, vinylpyrrolidone, vinyl cyclohexane, acrylic acid and methacrylic acid and / or their esters (preferably vinyl, allyl and methyl esters) with 1 to 4 carbon atoms in the alcohol component, their amides and nitriles, acid anhydride maleic, semi-esters and diesters with 1 to 4 carbon atoms in the alcohol component, hemiamines and diamines or cyclic imides such as N-methylmalide imide or N-cyclohexyl maleic imide; allyl compounds, such as allylbenzene, and alkyl esters, such as allyl acetate, diallyl phthalic acid ester, isophthalic acid diallyl ester, fumaric acid diallyl ester, allyl carbonate, diallyl carbonates, triallyl phosphate and triallyl cyanurate . When a vinyl or vinyloid comonomer is present, it will generally comprise up to about 60% by weight of the amount of the resin present. The vinyl ester resins useful in this invention include those which are described in US Pat. No. 3,367,992 wherein the half esters of dicarboxylic acid of methacrylates or hydroxy alkyl acrylates are reacted with polyepoxide resins. Bowen in the U.S. Patents. Nos. 3,066,112 and 3,179,623 describe the preparation of vinyol ester resins from monocarboxylic acids such as methacrylic and acrylic acids. Bowen also discloses alternative methods of preparation wherein a glycidyl acrylate and methacrylate are reacted with the sodium salt of a dihydric phenol such as bisphenol A. The vinyl ester resins based on epoxy novolac resins are described in the Patent of the USA No. 3,301,743 of Fekete et al. Fekete et al. Also describe in U.S. Pat. 3,256,226 vinyl ester resins wherein the molecular weight of the polyepoxide is increased by reacting a dicarboxylic acid with the polyepoxide resin as well as with the acrylic acid. Other difunctional compounds that contain a group that is reactive with an epoxide group such as an amine, mercaptan, and the like, can be used in place of the dicarboxylic acid. All the resins described above, which contain the characteristic bonds -C (O) -OCH CH (OH) CH20- and the terminal polymerizable vinylidene groups, are classified as vinyl ester resins and are incorporated herein by reference.

Briefly, any of the known polyepoxides can be employed in the preparation of the vinyl ester resins useful in this invention. Useful polyepoxides are glycidyl polyethers, both polyhydric alcohols and polyhydric phenols, epoxy novolac resins, epoxylated fatty acids or dry oily acids, epoxidized diolefins, esters of diunsaturated epoxidized acids, as well as unsaturated epoxidized polyesters, while containing more than one group oxirane per molecule. The polyepoxides can be monomeric or polymeric. Preferred polyepoxides are glycidyl polyether alcohols of polyhydric alcohols or polyhydric phenols weighing about 150 to 2000 epoxide group. These polyepoxides are usually made by reacting at least two moles of an epihalohydrin or a glycerol dihalogenhydrin with one mole of the polyhydric alcohol or of polyhydric phenol, and a sufficient amount of a caustic alkali to combine with the halogen of halogenhydrin. The products are characterized in the presence of more than one epoxide group per molecule, that is, an equivalence of 1,2-epoxy greater than one. Unsaturated monocarboxylic acids include acrylic acid, methacrylic acid, halogenated methacrylic or methacrylic acid, cinnamic acid and the like and mixtures thereof, and hemiesters of hydroxyalkyl acrylate or methacrylate of dicarboxylic acids as described in U.S. Pat. No. 3,367,992 wherein the hydroxyalkyl group preferably has from 2 to 6 carbon atoms. Preferably, the phase of the tervalent resin comprises from 40 to 70 weight percent of the vinyl ester or polyester resin and from 60 to 30 percent of a copolymerizable monomer. Suitable monomers include aromatic vinyl compounds such as styrene, vinyltoluene, vinylbenzene and similar saturated alcohols such as methyl, ethyl, isopropyl, octyl, etc., esters of acrylic acid or methacrylic acid; vinyl acetate, diallyl maieate, dimethalyl fumarate; mixtures thereof and all other monomers that are capable of copolymerizing with the vinyl ester resin and which are essentially insoluble in water. Another embodiment of this invention uses a modified vinyl ester resin wherein from about 0.1 to 0.6 moles of a dicarboxylic acid anhydride per equivalent of hydroxyl is reacted with the vinyl ester resin. The acid anhydrides, both saturated and unsaturated, are useful in said modification. Suitable dicarboxylic acid anhydrides containing ethylenic unsaturation include maleic anhydride, citraconic anhydride, itaconic anhydride, unsaturated aliphatic dicarboxylic acid anhydrides and the like. The modified vinyl ester resin is used in this invention in the same manner as described above for the unmodified vinyl ester resin. An important aspect of the present invention is that the thermosetting vinyl ester or polyester resin composition contains both a promoter and an inhibitor, wherein the promoter and the inhibitor are present in certain carefully controlled amounts with respect to one another. The promoter is a transition metal salt, or a combination of two or more transition metal salts. Suitable transition metals include manganese, iron, cobalt, nickel, copper and tin. The salts are preferably one or more halides, carboxyiates, alkoxides, amines, or mixtures thereof. Halides include fluorides, chlorides, and bromides, chlorides are preferred. Preferably, the carboxylates are derived from organic monocarboxylic acids having from 6 to 24 carbon atoms. Useful acids include monocarboxylic and alicyclic, aromatic, aliphatic, saturated and unsaturated acids, for example, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, octanoic acid, nonanóico acid, isononanoico acid, lauric acid, míristico acid, stearic acid, acid araquídico, behenic acid, oleic acid, linoleic acid, erucic acid, benzoic acid, p-tert-butilbenzoic acid, salicylic acid, naphthenic acid, ricinoleic acid, a-hydroxystearic acid, monobutyl maleate, monodecyl phthalate, cyclopentanoic acid, cyclohexane acid, cycloheptanoic acid, and methylcyclohexanoic acid. The salts of the generally preferred aliphatic monocarboxylic acids have from 8 to 12 carbon atoms or the alicyclic acids have from 5 to 7 carbon atoms and are present in the accelerator systems. Cobalt naphthenate and cobalt 2-ethylhexanoate and their mixtures are especially preferred. Preferred alkoxides are straight or branched saturated alkoxides having from 2 to 24 carbon atoms. Preferred amines are primary and secondary amines substituted with alkyl containing a total of 2 to 24 carbon atoms. Preferred inhibitors, for example, are phenols or phenolic derivatives, including sterically constricted phenols having alkyl substituents with from 1 to 6 carbon atoms in one or both of the ortho positions for the hydroxyphenolic group, β-diketones, amines, preferably secondary amines and their derivatives, quinones, copper salts of organic acids, and copper (I) halide addition compounds with phosphites Examples include 4,4, -bis- (2,6-di-tert.-butyl) -phenol), 1,3,5-trimeti1-2,4,6-tris- (3, 5-di-tert. -buty1-4-hydroxybenzene), 4,4'-butylidene-bis- (6-tert -butyl-m-cresol), 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid diethyl ester, N, N'-bis (B-naphthyl) -p-phenylenediamine, N, N'-bis - (l-methylheptyl) -p-phenylenedia ina, phenyl-β-naphthylamine, 4,4'-bis (aa-dimethylbenzyl) -diphenylamine, 1, 3,5, -tris- (3, 5-di-tert. -butii-4-hydroxyhydrocinnamoyl) -hexahydro-s-triazine, hydroquinone, p-benzoquinone, toluhydroquinone, trimethylhydroxy quinone, 3,5-di-tert. -butylhydroquinone, 2,6-di-tert. -butyl-hydroquinone, 3,5-dibutylquinone, p-tert. -butylpyrocatechol, chloranil, bromanil, naphthoquinone, copper naphthenate, copper octoate, Cu (I) Cl / trimethyl phosphite, Cu (1) Cl / -trimethylphosphite, Cu (I) Cl / trischloroethyl phosphite, Cu ( 1) Ci / tripropyl phosphite or p-nitrosodimethyl aniline. Other suitable stabilizers are described in "Methoden der organischen Chemie" (Houben-eyl), 4th Edition, Volume. X1V / 1, pages 433-452, 756, Georg Thieme-Verlag, Stuttgart, 1961. Preferred inhibitors include hydroquinone, benzoquinone, tert-butyl catechol and more preferably 4-methoxyfenoi (also known as hydroquinone monomethyl ester) and 4- ethoxyphenol. Mixtures of inhibitors are also contemplated. It has surprisingly been found that thermosetting compositions contain a greater amount of an ethylenically unsaturated polyester, and / or vinyl ester, and an organic peroxide initiator component, can be formulated so that when the inhibitor promoter is present in amounts with respect to one with the other having a certain relationship, the compositions exhibit all the advantages provided by the presence of the promoter and the inhibitor, however they exhibit a healing behavior that is independent of the amount of the current promoter (and thus also independent of the amount of the promoter). present inhibitor) so that the amount of the initiator of the organic peroxide present is essentially the only variable composition that affects the performance of the curing of the thermosetting composition. This is a particularly surprising finding so that it could be expected in all cases that the amount of promoter, the amount of inhibitor, and the amount of peroxide initiator all contribute essentially independently of each other than when carrying out the healing of the In this way, they require the multivariate equilibrium of the conditions and complexity imposed in the task of obtaining the realization of reproducible healing.

Now, however, by virtue of this discovery, it is possible to obtain the advantages of the promoter and the advantages of the inhibitor, although they obtain the freedom from which they are provided having to adjust only the content of organic peroxide initiator in order to obtain the characteristics of desired curing such as gelling time. Processing in accordance with this invention also provides improvements in gelation time, life in the crucible, and the remainder between the gelation time and life in the crucible. More particularly, it has been found that the weight ratio of the promoter (such as metal) to the inhibitor should be in the range of about 1: 1 to 0.01: 1, preferably from about 0.9: 1 to about 0.05: 1, and yet more preferably from about 0.8: 1 to 0.1: 1. Although in carrying out the curing of the composition is essentially independent of the content of the promoter provided in this manner which is observed in this relation, it will be appreciated that for practical reasons the amounts of the promoter and the inhibitor must be within the reasonable limit. In this way the amount of the promoter (based on the metal) should generally be within the broadly defined scale of about 0.0001 to about 0.50 ppc (parts by weight per hundred parts by weight of resin, including any reactive polymerizable monomer added) , preferably within the range of approximately 0.0005 to 0.4 ppc, and more preferably from about 0.001 to 0.3 ppc. The inhibitor should be present in the range of about 0.0001 to about 1.0 ppc. preferably from about 0.001 to about 0.75 ppc, and more preferably from about 0.005 to 0.5 ppc. The present invention is particularly useful with organic peroxide initiators having half-life temperatures of 10 hours or 30 ° C or higher. When it is desirable to sustain life in a crucible (as in the case with some extrusion and molding processes), the peroxide initiator must exhibit a mean life temperature of 10 hours equal to or greater than 90 ° C. As is known in this field, the half-life temperature of 10 hours is defined as the temperature at which a given peroxide compound is converted to 50% by its decomposition products by residing at that temperature for 10 hours. Organic peroxides that exhibit this property can easily be identified by those of ordinary skill in the art from published references and commercial literature. In addition, the 10-hour half-life temperature of any given peroxide can be readily determined by those of ordinary skill in the art by the application of well-known analytical techniques. Examples of peroxides exhibiting these properties include t-butyl peroxybenzoate, tallow peroxybenzoate, t-butyl peroxyisononanoate, t-amyl peroxyisononanoate, t-butyl peroxy-2-methylbenzoate, t-amyl peroxy-2-methylbenzoate. , t-butyl peroxyacetate, t-amyl peroxyacetate, di- (4-t-butyl-cyclohexyl) peroxydicarbonate, t-butyl peroxyisopropyl carbonate, and 1,1-di- (t-butylperoxy) -3,5, 5- tri-ethylcyclohexane. Other useful peroxides include butyl peroxineoheptanoate, cumyl peroxineheptanoate, di- (sec-butyl) peroxydicarbonate, di- (2-ethylhexyl) peroxydicarbonate, t-amyl peroxydecanoate, t-butyl peroxineodecanoate, t-amyl peroxyneheptanoate. , t-butyl peroxineoheptanoate, t-amyl peroxypivalate, t-butyl peroxypivalate, di-isononanoyl peroxide, 2,5-dimethyl-2,5-di- (2-ethylhexanoylperoxy) hexane, peroxy 2-ethylhexanoate of t -amyl, t-butyl 2-ethylhexanoate peroxy, benzoyl peroxide, l-bis- (t-amylperoxy) -cyclohexane, 1,1-bis- (t-butylperoxy) cyclohexane, peroxy-2-ethylhexyl carbonate t-butyl, dichumyl peroxide, di-tert-amyl peroxide, di-tert-butyl peroxide, eumeno hydroperoxide, methyl ethyl ketone peroxide, and 2,4-pentanedione peroxide. The most preferred peroxides for the purposes of this invention are t-amyl peroxybenzoate and t-butyl peroxyisononanoate. Other satisfactory peroxide initiators can be formed by mixing two or more peroxide compounds. The organic peroxide initiator component must be present in an amount effective to initiate the desired cure of the ethylenically unsaturated resin component by exposure to the initiation temperature. Although the particular amount can easily be identified to provide a series of components and amounts, it can generally be established that the amount of organic peroxide initiator component in general should be in the range of 0.1 to about 10 ppc, preferably on the scale of about 0.3 to about 7.5 ppc, and more preferably in the range of about 0.4 to about 6.0 ppc. Formulations of thermosetting resins prepared in accordance with this disclosure provide a number of advantageous properties. One of the main advantages, as mentioned, is the relative freedom provided to the formulator so that the concentration of peroxide initiator is the only variable composition that affects the functioning of the cure. This in turn gives the operator considerable increased freedom, and also increases the inherent safety of the system and its use.

In practice, the promoter and the inhibitor can be compounds per se in the polymerizable resin. Alternatively, the promoter and the inhibitor can be combined in a suitable solvent, and the resulting solution is then combined with the polyester resin. Suitable solvents can easily be identified by those of ordinary skill in the art. Examples include mineral spirits, benzene, toluene, xylene, mesitylene, or 2,2,4-trimethyl-1,3-pentanediol diisobutyrate ("TXIB"). The preferred solvent is a mixture of mineral alcohols and TXIB. In those embodiments wherein other polymerizable comonomers are also present such as styrene, vinyltoluene, divinylbenzene, methyl acrylate, methyl methacrylate, or 2- (acetoacetoxy) ethyl methacrylate, the monomer may be present in the solvent or in appropriate cases in which the monomer can in fact serve as a solvent. The resulting polymerizable resin compositions can be used in any form in which thermosetting polyester resin compositions can be used. A particularly preferred operation that utilizes the thermocurability advantage of the composition is known as "pultrusion". This operation employs a fibrous, solid reinforcing means, typically glass fibers and / or a mat of interwoven glass fibers. The reinforcing means is continuously pulled through a bath containing the thermosetting resin composition (which also contains in the case of the present invention the promoter, the inhibitor and the organic peroxide initiator component). The composition is in the liquid state, such as or, by virtue of being dissolved or dispersed in a suitable liquid solvent or vehicle such as any of the aforementioned monomers in the liquid state. The reinforcing means is continuously pulled through the resin bath and then through a heated matrix. The heat imparted by the matrix cures the resin in the matrix so that the form that is imparted to the composition of the composition and to the reinforcing medium by the matrix is retained. As is well known any of an unlimited number of profiles in cross section can be imparted to the resulting solid article by the matrix. The present invention is particularly useful in pultrusion operations, particularly since the operator only needs to adjust the level of the peroxide initiator in the thermosetting composition in order to adjust the operating characteristics so that the dimensions of the object being formed, are obtained in order to optimize the characteristics and conditions of healing.

Other examples of curing operations to which the present invention is applicable include filament winding, volume and sheet molding compounds, resin transfer molding, thermofixation injection molding. In any of these operations a means of reinforcement may be included. For example, this may comprise filaments, or cut fibrous material. The curing of the composition is generally provided by heating to a temperature in the order of about 26.6 ° C to about 426.6 ° C. As recognized in this field, the particular temperature can be adjusted by the operator to produce a desired cure setting time and cure rate. Preferred operations are carried out at 37.7 ° C to 371.1 ° C and more preferably at 48.8 ° C to 260 ° C. These can in turn be affected by considerations of the dimensions of the cured article, the desired production rate and the like. The promoter and the inhibitor can be combined as indicated after the mixture is compounded with the vinyl ester or polyester resins, or if desired the promoter and the inhibitor can be separately composed within the resin.

The present invention is illustrated in the following examples, which are provided for purposes of description and not to be construed as limiting the scope of what is considered to be the invention. Axis "1 Resin Materials: A polyester resin is used for general use (Reichhold 31020-03). Promoters: The cobalt naphthenate promoter is used as a 6% Co solution in mineral spirits (OMG Chemical). The cobalt 2-ethylhexanoate promoter was used as a 12% Co solution in mineral spirits (Strem Chemical). Inhibitors: All inhibitors - 4-methoxyphenol (HQMME), 4-ethoxyphenol (HQMEE); hydroquinone (HQ); t-butylcatechol (TBC); Dimethoxybenzene (DMB) - were sold by Aldrich. (All are commercially available in bulk). Promoter / Inhibitor pre-mixes: Promoter / inhibitor solutions (Pro / In solutions) were made using the following general procedure: The inhibitor (HQMME, HQMEE, HQ, etc.) was dissolved in an appropriate solvent (txib, toluene , etc.) then the desired amount of the promoter solution (cobalt naphthenate [Co 6%] in mineral spirits or cobalt 2-ethylhexanoate [Co 12%] in mineral spirits) was added to produce the final solution. The order of the reagent addition is not important. The concentrations of the promoter / inhibitor solutions used in the examples were as follows: • Examples 3.01-3.07 and 4.01 4.05: 66.7% of the solution of cobalt naphthenate (Co 6% in odorless mineral spirits), 26.6% txib and inhibitor 6.7%; Example of the solution of cobalt naphthenate of 5.01-50% (Co at 6% in odorless mineral spirits) TX1B at 40% and HQMME at 10%; Example of cobalt naphthenate solution at 5.02-50% (Co at 6% in odorless mineral spirits), 40% toluene and 10% HQMME; • Example 5.03-50% solution of cobalt 2-ethylhexanoate (Co 12% in odorless mineral spirits), N-methylpyrrolidone 40% and HQMME 10%; Example 5.04-50% solution of cobalt-2-ethylhexanoate (Co 12% in odorless mineral spirits), 2- (acetoacetoxy) ethacrylate 40% and HQMME 10%.

Gelified experiments in hot blocks A hot block gelation tester was used to assess the curing characteristics of the resin. The experiments were carried out using the following procedures: A resin sample of 50.0 ± 0.10 grams was measured in a 157.5 gram paper cup. Any promoter (metal salts, e.g., cobalt naphthenate solution) and inhibitor (e.g., HQMME) or the premixed promoter / inhibitor solution was added to the resin at ± 0.01 grams and mixed in the resin using A spatula. The peroxide initiator was then weighed in the ± 0.01 gram cup after mixing with a spatula. All the resin samples were made consecutively to reduce partial errors. The resulting mixture was coated and equilibrated at room temperature for 15 to 30 minutes. A 5 milliliter aliquot of the catalyzed resin mixture was supplied to the cavity of a preheated hot block tester. The cavity was lubricated with silicone grease with a release agent. The temperature of the resin during the cure was recorded through a thermocouple and a registration diagram. Each of the experiments was terminated after the peak of the exotherm was observed. The gelation time was taken at -12.2 ° C above the block temperature. The peak exotherm is the maximum temperature achieved during the healing process. The time of the exotherm (exo time) is the time in which the peak exotherm was reached. Pot life The catalyzed resin sample that remains (prepared as above) was left at room temperature (this is 22.2-25.5 ° C) and checked periodically for the gelation signals. The crucible of the resin initiated was taken as the first sign of gelation formation in the sample. When a range was reported, that range is from the last moment the "ungelled sample was verified while the first gelation was observed." Discussion of the Examples Table 1 (Example 1.01-1.05) shows the typical effects of the levels of variation of the inhibitor, promoter, and peroxide in the curing of the unsaturated polymer resin Since the concentration of the inhibitor was concentrated, the curing time and crucible life also increased, Conversely, an increase of the promoter relative to the peroxide or peroxide results in a decrease in curing time and crucible life The curing control of the resin is complicated since each additive can have a dramatic effect Table 2 (Examples 2.01-2.09) exhibits the inventive system where the relatively constant healing characteristics are achieved through the appropriate formulation of promoter to inhibitor. When inhibitor is used, the same healing response is achieved over a broad level of use. Healing is controlled by varying the peroxide concentration. Table 3 (Examples 3.01-3.07) shows how the invention can be further simplified by pre-mixing the promoter and the inhibitor in an appropriate solvent. This offers a more reproducible, safer means to supply the additives to the resin before being cured. Again, the healing characteristics are constant over a range of additive addition. It also shows the prolonged life in the crucible. Table 4 includes the operation of several inhibitors (Example 4.01-4.05). Hydroquinone monomethyl ether (HQMME) and hydroquinone monoethyl ether (HQMEE) offer the best performance in both resin curing and crucible life. Hydroquinone (HQ) and t-butyl catechol (TBC) provide good response to healing but are less effective in increasing crucible life. Dimethoxybenzene (DMB) was at least effective. With dimethoxybenzene, pot life was also short to measure healing performance. The effect of the various solvents on the operation of the pre-blended solutions of the polymer promoter is shown in Table 5 (Examples 5.01-5.Ü4; Examples of non-polymerizable solvents - txib, toluene, and N are included. - methyl pyrrolidone - and a polymerizable solvent - (acetoacetoxy) ethyl methacrylate Also shown in table 5, the effectiveness of two different promoters - cobalt naphthenate and cobalt 2-ethylhexanoate -.

Tab 1. Effects of promoter variation, peroxide and inhibitor concentrations in the cured ream (gel time and exotherm time) and crucible life.

Ejeiflo Sol. Co PeróPeróInhiInhiType Type Life type Co-mhib a pro. ppc. xido xido bidodor de de en pc. ppc. ppc. gelifi- exo criReía- Relacacion mn. solción cion ± 0.100 ± ü.100 hour in lolar weight 1. 01 - - 1.50 tbpi - - 1.375 1.969 - - - 1.02 0.20 0.012 1.50 tbpi - - 0.723 1.205 8 a 20 - - 1.03 0.25 0.015 1.50 tbpi - - 0.704 1.19u 8 a 20 - - 1.04 0.10 0.00b 1.50 tapb ~ - 0.722 1,160 8 to 20"- 1. 05? .10 0.006 2.00 tbpi 0.010 HQMME 0.715 1.225 > 52 0.60 1.26 I.OD 0.10 0.006 2.00 tbpi 0.020 HOME 0.768 1.262 > 72 0.30 0.63 1. 0 / 0.10 0.006 2.00 tbpi 0.030 HOME 0.829 1.348 > 72 0.20 0.42 1. 08 O.l? 0.00b 2.00 tbpi 0.040 HOME 0.699 1.422 > 72 O.b 0.32 1. 05 0.10 0.006 2.00 tbpi 0.030 HQNM 0.829 i.346 > 72 0.2 0.42 1. 10 0.20 0.012 2.00 tbpi 0.030 HQMSL 0.738 1.263) 52 Ü.4U 0.84 j i.11 0.30 i 0.018 2.00 tbpi 0.0 30 HQÜML 0 .b64 i .214 > 72 í i.óú 1..0 1. 12 0.40 0.024 2.ÜU tbpi 0.030 HQ? ME. Ú.b69 1.201 52-52 0.60 1..9 1. 13 0.10 0.006 0.55 tupi 0.010 Hßü.u 1,162 1,693 > 72 ü.bú i.2o 1. 14 0.10 0.00b 2. Ou tDpi 0.010 HQSY, 0.515 1.22o > 72 O.bO 1.2o 1. 15 0.10 0.00 3.25 topí 0.010 HQÜME 0.634 1.12o 27-52 ü.ó? i.2o á ± Table 1 (continued) Peroxide. Co-Peroxide-Inhibitor Laughter-Laughter-Laughter-Relationship tion in en in weight? Olar weight lolar 125 32 - -luO 2o - - 250 64"~ 333 85 20u 106 333 65 100 54 333 85 67 36 333 85 50 27 333 85 67 36 Ib / 43 67 36 111 26 67 3o 63 21 67 36 125 32 75 40 333 65 200 106 542 138 325 155 Notes: Hot block at 121"C, msaturated polyester resin, The exotherm peak was 171 ± -6.6" C for all conditions; Pro sol cobalt naphthenate (Co ai 6% in odorless mineral spirits); tbpi is t-butyl peroxnsononanoate; tapb is t-amiio peroxybenzoate; HQ MÜ is 4-methoxyf enoi.

Table 2. M effect of constant promoter at innyriator ratio on resin curing.

Ejenplo Sol. Co PeróPeróInhiInhi- Tieapo Tieipo Co-inhibitor pro. ppc. oxido bidodor de de pc. ppc. ppc. gelifi- exo Reía- Relacion a. 100% in weight noir 2. 01 0.10 0.006 0.75 tbpi 0.010 1.162 1.693 u.bü? .. b 2. 02 0.10 0.006 2.00 tbpi 0.010 HQMME 0.715 1.225 O.bO 1.2b 2.03 0.20 0.012 2.00 tbpi 0.020 HQMME 0.686 1.201 0.60 1.26 2.04 0.25 0.015 2.00 tbpi 0.025 HQMME 0.682 1.203 0.60 1.2o 2.05 0.30 0.018 2.00 tbpi 0.030 HOME 0.684 1.204 0.60 i.26 2.06 0.40 0.024 2.00 tbpi 0.040 HQMME 0.710 1.2.3 0.60 1.2o 2. 07 0.10 0.006 3.25 tbpi 0.010 HQMME 0.634 1.120 0.60 1.26 2. 08 0.10 0.006 2.00 ibpi 0.015 HQMME 0.541 1.253 0.40 0.84 2.09 0.20 0.012 2.00 tbpi 0.030 KQMME 0.736 i.263 0.40 0.64 2.10 0.30 0.016 2.00 tbpi 0.045 HfiMME 0.764 1.316 0.40 0.64 2. 11 0.10 0.006 2.00 tbpi 0.020 HQMME 0.766 1.262 0.30 u.63 2.12 0.15 0.009 2.00 tbpi 0.030 HQMME 0.779 1.3U1 0.30 O.o3 2.13 0.20 0.012 2.00 tbpi 0.040 HQMME 0.796 1.333 0.30 0.o3 2.14 0.25 0.015 2.00 tbpi 0.050 HQMME 0.82o 1.378 0.30 O.o3 2. 15 0.10 0.006 2.00 tbpi 0.025 HQMME 0.798 1.3U 0.24 0.51 2.1b 0.15 0.009 2.00 tbpi 0.038 HQMME 0.627 1.354 0.24 0.51 2.15 0.20 0.012 2.00 tDpi 0.050 HQMME 0.866 1.411 0.24 0.51 2. 16 0.10 0.00o 2.0u tbpi 0.030 HQ ??, 0.829 1.343 u.20 0.42 2.19 o.b 0.0u9 2.00 tbpi 0.045 HQMÍ, ü. S and 1.412? 0.4.

Peroxide.Co Peroxide-Pilela- Inhibitor Relay- Relationship in en in in weight Dollar solar weight 125 32 75 40 333 65 200 106 io5 43 100 54 133 34 80 43 111 28 67 36 63 21 50 2? 542 136 325 175 333 65 133 72 167 43 67 36 iii 28 44 24 333 85 100 54 222 57 67 36 167 43 50 27 133 34 40 22 333 85 80 43 222 57 53 29 167 43 40 22 333 85 67 36 222 57 44 24 Notes: Hot block at 121 ° C; msatured polyester resin; The peak exotherm was 171 ± 6.6"C for all conditions: Pro sol cobalt naphthenate (Co at 6% in odorless mineral spirits), tbpi is t-butyl perox- onononanoate, tapb is t-amyioperoxybenzoate, HgMME is 4 -methoxifenoi.

Table 3. The use of premixed promoter / inhibitor (pro / in) solutions for healing resins Ejeiplo Sol. Co PeróPeróInni- InhiType Type Tieipo Vida Co-innibidor Pro / ppc. xido xido bidor bidor de en en pc. ppc. gelifi- exo criReía- Relappc. cation solción tion sin. hours in lolar weight 3. 01 0.15 0.006 0.75 tbpi 0.010 HQMME 1.214 1.746 > 72 0.60 i.26 3. 01 0.15 0.006 2.00 tbpi 0.010 HQMM 0.758 1.262 > 72 O.oO i.2b 3. 02 0.38 0.015 2.00 tbpi 0.025 HQMME 0.736 1.244 > 72 0.60 i. 6 3. 03 0.60 0.024 2.00 tbpi 0.040 HQMME 0.768 1.262 > 72 0.60 i. or 3. 04 0.15 0.006 3.25 tbpi 0.010 HQMME 0.517 1.211 > 72 0.60 1.26 3. 05 0.15 0.006 1.75 tapb 0.010 HQMME 0.711 1.18b 20 to 360.60 1.26 3. 06 0.36 0.015 1.75 tapb 0.025 HQMME 0.634 1.117 20 to 360.60 1.26 3. 07 0.60 0.024 1.55 tapb 0.040 HQMME 0.621 1.095 20 a 3b O.bO i.2b Table 3 (Continued) PeroxiaoiLO oxiao-inniDiaor Laughter- Laughter- Laughter- Relationship in the weight of soiar weight loiar 125 32 75 40 333 65 200 108 132 34 79 43 83 21 50 27 542 136 325 175 292 62 175 104 115 33 69 41 73 21 44 26 Notes: hot block at 121 ° C, ream of unsaturated poiester; the peak exotherm was 17 ± 6.6 ° C for all conditions; Pro / ín is a mixture containing cobalt naphthenate solution at 66./% (Co at 6% in odorless mineral spirits, 26.6% txib and HQMME is 6.7%, tbpl is t-butyl perox- onononanoate, tapb is peroxybenzoate t-amiio, HQMME is 4-methoxyf enoi.

Table 4. The effect of several inhibitors by the cured resin and life of the crucible.

Ejesplo Sol. Co Pero- Per- ini- InhiTl € ipo Tiespo Viaa 10-? NniDi? Or JTO / ppc. oxido ppc. ppc. geiifi- exo criRelaRelappc. cation without. solción tion sin. hours in solar weight 4. 01 0.15 0.006 2.00 tapb 0.010 HQMME 0.686 1.125 20 a 36 ú.óú 1.26 4. 02 0.15 0.006 2.00 tapb 0.010 HQMEE 0.750 1.250 20 to 3o 0.60 i.41 4. 03 0.15 0.006 2.00 tapb 0.010 HQ 0.688 1.166 6 to 20 0.60 i.12 4. 04 0.15 0.006 2.00 tapb 0.010 TBC 0.719 1.166 6 to 20 O.oO i.69 4. 05 0.15 0.006 2.00 tapb 0.010 DMB - - < .6 O.óí 1.41 Peroxide: Co Peroxide: inhibitor RelaRelaRelaRelation in en in in solar weight solar weight 333 94 200 119 333 94 200 133 333 94 200 106 333 94 200 160 333 94 200 133 Notes: Hot block at 121"C, unsaturated resin, the peak exotherm was 171 ± -6.6" C for all conditions; Pro / in is a mixture containing cobalt naphthenate solution at 66.7% (Co ai 6% in harmless mineral spirits), txib at 26.6% and inhibitor at 6.7%; tapb is t-amiio peroxybenzoate; HQMME is 4-methoxyphenoi; HQMEE is 4-ethoxynyol, HQ is hydroquinone; TBC is t-butyl catechoi; DMB is dimethoxybenzene Table 5. The use of various solvents and other cobalt salts to make the promoter / inhibitor (pro / in) solutions.

Ejespio Soi. Co But- But- Inhi- Inni- Tieipo Tiespo Life Co-mhibiQor Pro / ppc. oxido ppc. ppc. gelifi- exo criReía- Relappc. cation without. solción cion sin. hours in solar weight . 01 0.20 0.006 2.00 tapb 0.0200 HQMME 0.688 1.177 20 a 3b 0.30 0.63 . 02 0.20 0.00b 2.00 tapb 0.0200 HQMME 0.671 1.168 20 a 3b 0.30 Ú.b3 . 0. 0.10 0.006 2.00 tapb 0.0100 HQMME 0.668 1.188 20 a 36 0.60 i.2o . 04 0.10 0.006 ¿. \) \ Tapb 0.0100 HQMME 0.719 1.156 2u a 3o u.bO i.2o Peroxide. Co Peróxioo: Laughter inhibitor - Laughter - Laughter - Relationship to the weight of the body in solar weight 333 94 100 60 333 94 iüO 60 333 94 200 119 333 94 200 119 Notes: hot block at 2 ° C, saturated resin resin, peak exotherm was 171 ± -6.6 ° C for all conditions, Pro / in solutions are as follows: cobalt naphthenate solution 5.01-50% (Co ai 6% in odorless mineral spirits), 40% txib and 10% HQMME, cobalt naphthenate solution 5.02-50% (Co 6% in odorless mineral spirits), toluene 40% and HQMME 10%, solution 2 50% cobalt-ethylhexanoate (12% Co in odorless mineral spirits), 40% N-methyl pyrrolidone and 10% HQMME, cobalt 2-ethylhexanoate solution 5.04-50% (12% Co in odorless mineral spirits), 2- (acetoacetoxy) ethyl methacrylate 40% and HQMME 10%, tapb is t-amyl peroxybenzoate, HQMME is 4-methoxyphenol.

Y

Claims (16)

1. A thermosetting polymer composition comprising (a) a resin selected from the group consisting of ethylenically unsaturated polyesters and vinylic esters and mixtures thereof; (b) an organic peroxide component which is capable, by heating, of decomposing into free radicals initiating curing by polymerization of said resin, whose peroxide component exhibits a half-life temperature of 10 hours greater than 30 ° C; (c) a promoter for the decomposition of said peroxide and an inhibitor of the polymerization of said resin, wherein said inhibitor is present in an amount with respect to the amount of said promoter present so that the time of gelling of said composition is independent of the amount of the said promoter that is present.

2. A composition according to claim 1, wherein the weight ratio of said promoter, based on its metal content, to said inhibitor is from about 1: 1 to about 0.01: 1.

3. A composition according to claim 2, wherein said ratios from about 0.8: 1 to about 0.1: 1.

4. A composition according to claim 1, wherein said organic peroxide component is selected from the group consisting of t-butyl peroxybenzoate, t-amyl peroxybenzoate, t-butyl peroxyisononanoate, t-amyl peroxyisononanoate, peroxy -2-methyl t-butyl methylbenzoate, t-amyl peroxy-2-methylbenzoate, t-butyl peroxyacetate, t-amyl peroxyacetate, di- (4-t-butyl-cyclohexium) peroxydicarbonate, peroxypropyl carbonate butyl and 1, l-di- (t-butyl peroxy) -3,5,5-trimethylcyclohexane and mixtures thereof.

5. A composition according to claim 1, wherein said promoter is selected from the groups consisting of transition metal carboxyiates and transition metal halides.

6. A composition according to claim 5, wherein said promoter is selected from the group consisting of cobalt haftenate, cobalt 2-ethyl hexanoate and mixtures thereof.

7. A composition according to claim 1, wherein said inhibitor is selected from the group consisting of tert-butyl catechol, hydroquinone, benzoquinone, 4-methoxyphenol, 4-ethoxy phenol, and mixtures thereof.

8. A composition according to claim 1, further comprising a co-polymerizable comonomer selected from the group consisting of unsaturated vinyl compounds, unsaturated vinylidene compounds and mixtures thereof.

9. A method for curing an ethylenically unsaturated resin, comprising heating a thermosetting composition according to any of claims 1 to 8 at an effective temperature to cure said mixture.

10. A mixture useful for promoting heat-induced curing of a composition comprising a resin selected from the group consisting of ethylenically unsaturated polymers and vinyl esters and mixtures thereof, and an organic peroxide initiator component which decomposes upon heating in a Free radicals that initiate curing by polymerization of said resin, said peroxide exhibits a half-life temperature of 10 hours greater than 30 ° C, said mixture comprising a promoter for the decomposition of said peroxide and a polymerization inhibitor of said resin wherein said inhibitor is present in an amount with respect to the amount of said promoter present so that the time of geiification of a composition containing said resin, said starter component and said mixture is independent of the amount of said promoter. which is present in said composition.

11. A mixture in accordance with the claim 10, wherein the weight ratio of said promoter, based on its metal content, to said inhibitor is from about 1: 1 to 0.01: 1.

12. A mixture in accordance with the claim 11, wherein said ratio is from 0.8: 1 to 0.1: 1

13. A mixture according to claim 10, wherein said organic peroxide inhibiting component is selected from the group consisting of t-butyl peroxybenzoate, t-butyl peroxybenzoate, and -amyl, t-butyl peroxyisononanoate, t-amyl peroxyisononanoate, t-butyl peroxy-2-methylbenzoate, t-butyl 2-methylbenzoate, t-butylperoxyacetate, t-amylperoxyacetate, peroxydicarbonate di- (4-t-butyl-cyclohexyl), t-butyl peroxy isopropyl carbonate, and 1, l-si- (t-butyl peroxy) -3,5,5-trimethylcyclohexane and mixtures thereof.

14. A mixture according to claim 10, wherein said promoter is selected from the group consisting of transition metal carboxylates, transition metal halides, and mixtures thereof.

15. A mixture according to claim 14, wherein said promoter is selected from the group consisting of cobalt naphthenate, cobalt 2-ethylhexanoate, and mixtures thereof.

16. A mixture according to claim 10, wherein said inhibitor is selected from the group consisting of tert-butyl catechol, hydroquinone, benzoquinone, 4-methoxyphenol, 4-ethoxyphenol, and mixtures thereof.