CA2052224C

CA2052224C - Accelerators for curing phenolic resole resins

Info

Publication number: CA2052224C
Application number: CA 2052224
Authority: CA
Inventors: Arthur Harry Gerber
Original assignee: Borden Chemical Inc
Current assignee: Hexion Inc
Priority date: 1990-11-21
Filing date: 1991-09-25
Publication date: 1998-01-20
Anticipated expiration: 2011-09-25
Also published as: BR9103262A; JPH04300948A; JPH0762104B2; MY131202A; CA2052224A1

Abstract

There are disclosed methods and compositions for accelerating the hardening of phenolic resole resins having a pH of about 4.5 to 9.5 with lightburned magnesium oxide or magnesium hydroxide, with or without the addition of an ester functional hardening agent. Acceleration of hardening is achieved by incorporating into said compositions an effective quantity of a material which: increases the solubility of magnesium in the hardenable mixture; by certain amines; or by certain chelating agents. Accelerator compounds include those which provide chloride, sulfamate, nitrate, formate, and phosphite anions as well as selected tertiary amines.

Description

R. l . C.-2 1 95 1 0/1 5/90 ACCELERATORS FOR CURING PHENOLIC RESOLE RESINS

Background of the Invention This application is a continuation-in-part of my application serial number 07/562206, which was filed on August 2,1990.
This invention relates to methods and compositions for accelerating the hardening of phenolic resole resin binder compositions which are hardened with magnesium oxide or magnesium hydroxide alone or together with an ester functional hardening agent. Such hardening can take place at about room temperature.
It is often desirable to accelerate or shorten the time it takes for phenolic resole resins to harden by the use of a lightburned magnesium oxide or magnesium hydroxide hardener, alone or together with an ester functional hardening agent, particulary if such acceleration does not significantly affect the eventual hardness, tensile strength, and other desirable properties of the hardened or cured resin. This is particularly the case in cooler climates and lower temperatures.
Magnesium oxide or hydroxide, with or without an ester functional hardening agent, are used as the hardening agents in this invention.
Applicant has found that the hardening of phenoiic resole resin compGsitions admixed with hardening quantities of lightburned magnesium oxide or magnesium hydroxide, either alone or together with an ester functional hardening agent can be accelerated by use of certain amines or compounds which increase the solubility of magnesium from the hardener which is admixed with the resin. Illustrative of accelerators are compounds which provide R. l . c. -2195 10/1 s/so .) '' ' ;i ,; ,; '~

anions of chloride, sulfa~e, nitrate, and sulfamate as well as various amino compounds such as

2,4,6~tris(dimethylaminomethyl)phenol.
Lightburned magneshJm oxide and magnesium hydroxide are well known room temperature hardening agents for phenolic resole resins. Furthermore, magnesium oxide and magnesium hydroxide are used as the condensation catalysts for the manufacture of phenol-formaldehyde resole resins from phenol and formaldehyde. Additionally, relatively inactive magnesia, e.g., periclase or refractory grade magnesia, is a conventional refractory which is often bound into various shapes with phenolic resole resins; however the periclase is relatively inactive and is not used as a hardener. Illustrative of references which disclose the use of magnesium oxide or magnesium hydroxide to harden phenolic resole resins in various types of compositions, there can be mentioned U.S. Patents: 2,869,194 of Jan. 20, 1959 to R.H.
Cooper; 2,869,196 of Jan. 20, 1959 to R.H. Cooper; 2,913,787 of Nov. 24, 1959 to R.~i.
Cooper; 3,666,703 of May 30, 1972 to T. Murata et al; 2,712,533 of July S, 1955 to J.S.
Mitchell; 2,424,787 of July 29, 1947 to W.H. Adams, Jr.; and 4,794,û51 of December 27, 1988 to M.K. Gup~a.
The 4,794,051 Gupta patent also mentions ~he use of a class of ester functional hardening agents namely, lactones, which are used together with the magnesium hardeners, but preferably in admixture with calcium hardeners. The 2,869,194 Cooper patent also mentions that magnesium oxychloride and magnesium oxysulfate, which can be prepared by mixing magnesium oxide powder with an aqueous solution of magnesium chloride or its equivalent or magnesium sulfate or its equivalent, frequently provide shorter hardening times as oompared to the magnesium oxide alone. The 2,913,787 Cooper patent also mentions the optional inclusion in his compositions of ~novolak type" phenolics as well as optional inclusion of hexamethylene tetramine or equivalent curing agent or accelerator for R. I . C. -2195 10/15/90 J !'d /~1 i phenolic resins, including ethylene diamine, diethylene triamine and the like relatively low molecular weight polyamines and paraformaldehyde.
U.S. Patent Application Ser. No. 450,989 entitled "Phenolic Resin Compositions~ filed December 15, 1989 with P.H.R.~. Lemon, J. King, H. Leoni, G. Murray, and A.H. Gerber as inventors, which is based on GB 8829984.7 filed 12122/88, discloses the preparation of phenolic resole resins with alkali or alkaline earth metal compounds as the basic catalyst and the subsequent room temperature hardening of such resins with an esterified phenolic as the ester functional hardening agent together with various bases, including oxides and hydroxides of magnesium and calcium.
European Patent Application Publication Number 0û94165, which was published on November 1 6, 1983 with P.H.R.B. Lemon et al as inventors, has broad recitations which mention the use of various alkaline materials including magnesium oxide (magnesia) for condensing phenol and formaldehyde to form phenol-formaldehyde resins and for further increasing the alkalinity of such resins which use ester functional agents for hardening the phenolic resin. European Patent Application Publication No. 0243,172, which was published on 28 October 1987 and lists P.H.R.B. Lemon et al as inventors, has recitations similar to those of the above-mentioned 0094165 publication.
U.S. Patent 4,939,188, which issued on July 3, 1990 with A.H. Gerber as inventor, discloses the use of lithium ion generating alkalizing agents in resole resin binder compositions which, when hardened by an ester functional curing agent, exhibit tensile and compressive strengths superior to that obtained from compositions using sodium or potassium ion generating alkalizing agents.
U.S. Patent 4,0~ 1,186 of March 8, 1977 to Higgenbottom as well as 4,216,295 of Aug 5, 1980 to Dahms relate to phenolic resoles catalyzed with alkaline earth metal R.l.C.-219s 10/15/9o hydroxides and neu~ralized with oxalic acid or its acid sal;s which provide stable, inert, insoluble oxalate salts dispersed in said resole and, additionally increases Ihe viscosity of the resole resin.
U.S. Patent 3,624,247 of Nov. 30, 1971 to Gladney et al relates to the removal of residual calcium catalyst used in the production of phenolic resins. The residual calcium catalyst is removed by treatment with an alkaline solution of an ammonium salt which form an insoluble salt with calcium upon pH adjustment. Soluble ammonium compounds used in the process of the 247 patent are listed as sulfate, phosphate, and carbonate.
U.S. Patents Re 32,720 of July 26, 1988 and Re 32,812 of Dec. 27, 1988 to P.H.R.B.
Lemon et al are further illustative of the literature which discloses room temperature hardening of highly alkaline phenol-formaldehyde resole resins with an ester hardening (curing) agent.
Japanese Kokoi Tokkyo Koho JP 60/90251 of May 21, 1985 to Kyushu Refractories Co., Ltd., which discloses the cold-hardening of a ~hermoselting resole resin by the use of ethylene carbonate and magnesium oxide.

R ~ ',t~ ~p",~ 7L p~ t ~ 6~r 5~,qc~?7/~G ~ ac~ c(~ c~ Ar~ C~r r r~ f~/~g f ~ e ~ ra~ 9 d f~ c~cG s~ie r~s~ r r tJ ~r~,~m /~ t~

,' ' ' ':1 '~ ',,~ i' R. I . c . -2195 10/15/~0 SUMMAF~Y OF THE INVENTION

It has now been found that the room temperature hardening of phenolic resole resin compositions admixed with hardening quantities of lightburned magnesium oxide or magnesium hydroxide, either alone or together with an ester functional hardening agent, can be accelerated with certain amines or with materials which increase the solubility of magnesium in the reaction mixture. Further, it has been found that: the use of a relatively low surface area lightburned magnesium oxide when admixed with a higher surface area magnesium oxide has little effect in accelerating the hadening of the phenolic composition beyond that due to the high surface area material but provides grealer strength to the composition on thermal curing; the use of lithium carbonate is both an accelerator and a strength improver in the phenolic composition; and when sulfamate accelerators are used with low molecular weight phenolics, having a high free phenol content; the strength of the composition is improved. The phenolic resole resins used in this invention generally l1ave a pH of about 4.5 to 9.5.
In one aspect of the inventio.n, compositions and methods for preparing binders having a shor~ened hardening time are provided by mixing the phenolic resole resin with a magnesium hardening agent with or without an ester functional hardening agent and an accelerator.
In another aspect of this invention, the above-mentioned compositions and methods together with an aggregate are used for patching or resurfacing various rigid substrates such as concrete and asphaltic structures.
In another aspect, a shaped article is provided; the shaped article comprising an aggregate material bonded together by a resin binder; the binder comprising a hardened phenol-formaldehyde resin hardened in the presence of a magnesium hardening agent and an accelerator, with or without an ester functional hardener.

F~. I . C -2195 10/15/90 ;i ;j ,~ i Illustra~ive of accelera~ors, there can be mentioned materials which provide anions of chloride, sulfate, nitrate, sulfamate, phosphites, corresponding acid addition salts of basic nitrogen compounds and compounds of the formula:

N - X - N

wherein: X is a lower aliphatic hydrocarbon group, R1 and R2 are alkyl or together with the nitrogen to which they are attached form a heterocycle and R3 and R~ can be hydrogen, alkyl, or when R3 and R4 are taken together with the nitrogen to which they are attached form a heterocyclic group.

Advant3ges The processes and compositions of this invention provide a means for accelerating the rate of hardening of phenolic resole resins with magnesium hardening agents over a wide temperature range such as about 6û F to 120'F by use of small amounts of amines or various chemicals which increase the solubility of magnesium in the binder composition and accelerate the hardening of the resin. One of the variables affecting the rate of hardening of phenolic resole resins is temperature. Lower temperatures decrease the rate of hardening.

Therefore, by use of the accelerators of this invention, the hardening rate r,an be accelerated over a wide range of temperatures such as room or ambient temperatures, particularly in cooler climates or work places having lower temperatures. By use of the accelerators of R l C -2 1 95 1 0/1 5/gO
,, !

this invention, the hardening rate can be accelerated at low temperatures in order to maintain a desirable processing time while developing adequate strength.
The rnethods and compositions of this invention can also affect reaction rate of the phenolic resole resin by selection of surface area of the magnesia to be used, by choice of the specific accelerator, and, optionally, by choice of the specific ester as well as the quantities of the hardeners and accelerators.
Preferred methods and compositions of this invention utilize an ester functional hardening agent together with the magnesium hardening agent since the reaction rate of phenolic compositions are strongly affected when an ester is used with the lightburned magnesia or magnesium hydroxide hardener together with an accelerator. Furthermore, the hardened phenolic resole resins, which use both a magnesium hardening agent and an ester functional hardening agent, have greater compressive and tensile strengths as well as greater resistance to aqueous organic acids as compared to phenolic resole resins which have been hardened only with magnesium oxide or magnesiurn hydroxide.
The methods and compositions of this invention possess many advantages as compared to curing of phenolic resole resins with esters alone as shown in U.S. Re 32,72û of July 26, 1988 to Lemon et al and U.S. Re 32,812 of December 27, 1988 to Lemon et al. The processes and composnions of those paten~s require alkali metal hydroxides and for practical applications, the resins have a pH of greater than 12. In contrast to those patents, the present invention involves substantially lower pH values, and there is no need for alkali metal hydroxides or salts. The compositions and methods of the present invention have many advantages over those which do require high alkalinity, e.g., pH of 10 or 12 or more, particularly in view of the high alkali metal concentration required for the highly.alkaline compositions. Illustratively, the phenolics of the present invention have: ~etter shelf Pag~ 7 ~.I.C.-2195 10;15/90 s~abili~y; improved stability of resin color in relation to time and exposure to the atmosphere; !ower viscosities at higher solids levels which, among other ~hings, increases wettability of aggregate or subs~rate which, in turn, increases bond strength; safer material and waste handling properties; a higher density and less porosity on curing at the higher solids levels for resin, compositions, e.g., such as those containing aggregate which, in turn, increases strength and resistance to solvents and aqueous media; and improved stability with aggregates normally attacked by sodium or potassium at a high pH and improved stability to glass or polyester fiber. Excess alkali can result in strenglh loss, e.g., see Lemon et al Re 32,812, Table ~, wherein the effect of KOH/phenol molar ratio shows steady decrease in compressive strength of resoles as the mole ratio is increased from û.68 (5û32 psi) to 1.02 (4271 psi). In contrast to this, an excess of the magnesium hardener can increase strength and also insolubility oF the final composite because of the divalent cross linking by magnesium in comparison with chain termination by use of sodium or potassium alkalies.
Accelerators are also advantageous for reducing the strip time of molded or cast materials or simply to increase the hardening rate, particularly when temperatures are significantly below 70'F.

D~tailed Description of the Invention l~Aa~nesium Oxide and Ma~nesium Hydroxide I lardenino Aaents The term ~accelerator~ as used herein refers to a material which speeds up, hastens, or simply accelerates gelation or hardening of the phenolic resole resin in the methods and Fi. l.C.-2195 1 o/1 slso compositions of this invention such as the hardenable binders which contain the phenolic resole resin, a magnesium hardener, and optionally an ester functional hardening agent. Some of the accelerators of this invention appear to work by increasing the amount of magnesium or magnesium compound in solution, i.e., by changing trhe solubility of magnesium compound in the hardenable mixture.
The ~erm "hardening agent~ is used herein to denote a material which increases the rate of hardening of a phenolic resole resin, e.g., at room or ambient temperature (~.T.). Hardening is anained with increases in viscosity and gelation to form a solid which is firm to the touch and generally inflexible. The hardenable binder compositions of this invention which contain a phenolic resole resin, magnesium hardener and optionally an ester functional hardening agent but without an accelerator will generally be hard within about 24 hours of standing at 75-F.
Although such hardening can also be referred to as ~curing," the ~hardening" or ~curing~ with hardening agents does not develop the tensile and compressive strengths of a thermal cure.
By the term ~room temperature hardening~ we mean the hardening of compositions of this invention at temperatures of about 60~F to 90 F, particularly about 65'F to 80-F~ However, the use of acGelerators in the processes and compositions of this invention accelerate the hardening of compositions of this invention at lower and higher temperatures such as 60'F to 120'F. In addition to room temperature hardening, or hardening at ambient temperatures such as those of about 60-F to 120-F, the compositions of this invention can be thermally cured after hardening by the hardening agents or the compositions can be thermally cured prior to such hardening. The term "themmal curing~ as used herein means curing of the composition at a temperature of at least 170-F and generaly at a temperature of at least 212'F.
The magnesium hardening agents are magnesium hydroxide, lightburned magnesium oxide, or other magnesium oxide which has the hardening activity for phenolic resole resins of Pag~ 9 ~: ~U .~ R.l.C.-2195 10/15/90 A

lightburned magnesium oxide such as that having a surface area of at least 10 square meters per gram (10m2/g)~ Lightburned magnesium oxide is the preferred magnesium hardening agent because magnesium hydroxide gives lower strengths to the hardened compositions.
Small quantities of calcium hydroxide, calcium oxide, or calcined dolomite (doloma) can also be added as a hardening agent. However, the use of calcium oxide, calcined dolomite, or calcium hydroxide alone or in high quantities together with the magnesium hardeners have serious shortcomings. Thus, caicium based oxides, including calcined dolomite, or hydroxides are highly basic and react too quickly, thus greatly reducing the mix working time. However, minor quantities, e.g., from about 1% to less than 50% by weight based on the weight of the magnesium hardening agent, of these calcium containing compounds, when mixed with the magnesium hardening agents, can be used to replace an equivalent weight of the magnesium hardening agents. Preferably such minor quantities do not exceed about one-fourth of the total weight of the magnesium oxide or magnesium hydroxide hardening agent. An additional shortcoming in the use of calcium based oxides is ~hat they can insolubilize some of the accelerators.
Reactivity and surface area of magnesium oxide (magnesia) differ greatly depending on the procedure used for manufacture of the magnesia. Lightburned grades of magnesium oxide are calcined at temperatures ranging from about 1600 to 1~00-F. Hardburned grades are calcined at iemperatures ranging from about 2800 to 3000'F. Deadburned or periclase grade of magnesium oxide is calcined at temperatures of over 4000'F. The lightburned grades are generally available in powder or granulated form while hardburned grades are available in kiln run, milled, or screened sizes. Periclase is generally available as briquettes and as screened or milled fractions. There are large differences in surface areas for the various magnesias. Thus, lightburned magnesia has a surface area of about 10 to 200 or more square meters per gram R.i.C.-21 ss 1 0/l slso-A

(m2/9). Hardburned magnesia has a surface area of a~out one square meter per gram, whereas deadburned magnesia has a surface area of less than one square meter per gram. Magnesia which is conventionally used as a refractory aggregate is the deadburned or periclase magnesia.
Neither hardburned nor deadburned magnesia are effective hardening agents. It is the lightburned magnesia which is an effective hardening agent. Magnesia products having different surface areas can be obtained from the Martin Marietta Company under the designator of Mag Chem Magnesium Oxide Products. Illustratively, Mag Chem 30 has a surface area of about 25 square meters per gram. Mag Chem 50 has a surface area of about 65 square meters per gram whereas Mag Chem 200D has a surface area of about 170 square meters per gram.
One of the variables for viscosity increase, formation of gel and subsequent hardening of a phenolic resole resin is dependent on the surface areas of the lightburned magnesium oxide.
Magnesium oxides, with the higher surface areas, are more active and provide shorter times for gelation and hardening. Thus, lightburned magnesium oxide, having a surface area of less than about 25 square meters per gram, is slow acting and generally will not be used when it is desired to have the binder composition cure in a relatively short period of time at temperatures below about 1 20'F. On the other hand, magnesia having a higher surface area, such as about 65 square meters per gram (m2ig) and above, will harden the same binder composition in a shorter period of time. For many applications, using magnesia having a surface area of about 25 to 65 square meters per gram is suitable. Hardburned magnesia reacts too slowly as a hardener to be of practical value, and deadburned magnesia is sufficiently inert so that it is used conventionally as a refractory with phenolic resin binders with little or no effect on room temperature hardening rates.
The phenolic resole resins of this invention contain one or more volatile solvents, including water. Loss of solvent in the thermally cured compositions leads to increased porosity R.l.C.-2195 10/1 5/90 porosi~y and permeability ~o liquids and decrease of strength. One means for obtaining the higher strength and less porosity is to use a larger quantity of lightburned rnagnesium oxide hardener. However, this will further shorten the time of viscosity build up and gelation. It has now been found that lightburned magnesium oxide having at least two different surface areas can provide the improved results such as increased strength without substantially accelerating the viscosity build up. To attain such improved results, the lightburned magnesium oxide hardener comprises particles having at least tv~o different surface areas with aoout 25 to 75% thereof by weight having a surface area of at least ~0 square meters per gram and about 25 to 75%
thereof, by weight, having a surface area of about 1 û to 25 square meters per gram.
Preferably, the magnesium oxide hardener for such improved results consists essentially of particles having at least 2 different surface areas as set forth in the previous sentence. By following this method of using different surface areas, the room or ambient temperature gelation can take place in about the same time as with the higher surface area hardener used alone, even though there is substantially more of the hardener present but the compressive strength of the composition on curing is substantially increased and the composition has less porosity and less permeability. Furthermore, the fire retardency of compositions having the increased quantity of the magnesia is also improved. Compositions containing the lightburned magnesia of different surface areas will optionally contain an accelerator of this invention, an ester functional hardening agent as well as fillers, modifiers, aggregate, and other additives at the same concentration as with lightburned magnesium oxide which does not contain a mixture of the hardener having different surface areas.
The quantity of lightburned magnesium oxide or magnesium hydroxide which is used in this invention as a hardener is an amount sufficient to increase the rate of gela~ion or hardening of the phenolic resole resin. This quantity can vary over a wide range. The R. I.C.-219~ 10/~ 5/90 quantity of the magnesium hardener used will vary depending on whether or not an ester hardening agent is also used in the composition, the surface area of the magnesium oxide, the ~pecific ester hardening agent. the quantity of magnesium and ester hardening agent or agen~s, the temperature, and the desired result. Thus, the magnesium oxide or magnesium hydroxide hardening agent will generally vary from about 5% to 40% by weight of the resin in the various composilions and methods of this invention. ~lowever, when mixtures of lightburned magnesium oxide having different surface areas is used, the quantity of the magnesium oxide preferably varies from about 5% to 50% or more by weight of the resin.
When magnesium oxide or magnesium hydroxide hardener is used without the ester hardening agent, it is preferred that from about 10% to 40% by weight be used, based on the weight of the resin, and particularly 15% to 30% by weight based on the weight of resin. When the magnesium oxide or magnesium hydroxide is used together with an ester functional hardening agent, is is preferred that the quantity of magnesium oxide or magnesium hydroxide hardening agent vary from about 5% to 30% by weight of the resin, and particularly, from about 5% to 20%.

The Ester Hardenin~ Aaent The ester functional hardening agent, also referred to as ester functional curing agent, accelerates the hardening of the resole when used with the magnesium hardeners while at the same time use of both magnesium hardening agent and ester hardening agent mixed with the resole resin provide a hardening system which is very sensitive to small quantities of the acr,elerat~rs of this invention. Mixtures of phenolic resole resins and an ester functional hardening agent in the absence of magnesia, or other added alkali, will not harden at 70'F

Pag~ 1 3 R.l.C.-2195 10/15/90 wi~hin several days or longer. The ester functionality for hardening of the phenolic resole resin can be provided by lactones, cyclic organic carbonates, carboxylic acid esters, or mixtures thereof.
Generally, low molecular weight lactones are suitable as the ester functional hardening agent, such as beta or gamma-butyrolactone, gamma-valerolactone, caprolactone, beta-propiolactone, beta-butyrolactone, beta-isobutyrolactone; beta-isopentyllactone, gamma-isopentyllactone, and delta-pentyllactone. Examples of suitable cyclic organic carbonates include, but are not limited to: propylene carbonate; ethylene glycol carbonate; 1,2-butanediol carbonate; 1,3-butanediol carbonate; 1,2-pentanediol carbonate; and 1,3-pentanediol carbonate.
The carboxylic acid esters which can be used in this invention include phenolic esters and aliphatic esters.
The aliphatic esters are preferably those of short or medium chain length, e.g., about 1 to 1r~ carbon mono- or polyhydric, saturated or unsaturated alcohols with short or medium chain length, e.g., about 1 to 10 carbon aliphatic, saturated or unsaturated carboxylic acids which can be mono- or polycarboxylic. The preferred aliphatic esters are those of alkyl, mono-, di-, or trihydric alcohols with alkyl, or mono-, or diunsaturated acids which can be mono-, di-, or tricarboxylic. The carboxylic acids can be substituted with hydroxy, cyano, chloro, or bromo groups.
As to aromatic esters, such esters can be obtained by esterifying the aromatic, e.g., phenolic, group or groups of a mono- or polyhydric aromatic phenol to prepare a formate or acetate ester of such aromatic compound. Additionally, the aromatic ester can be an esterified phenolic compound containing one or more phenolic hydroxyl groups and/or one or more esterified phenolic hydroxyl groups and further containing one or more esterified , ~ ~, R.l.C.-2195 10~15/9o methylol groups positioned ortho and/or para lo a phenolic hydroxyl group or esterified phenolic hydroxyl group. Such phenolic esters and their method of manufacture are disclosed in U.S. Ser. No. 450,989 filed December 15, 1989 entitled ~Phenoiic Resin Compositions' with P.H.R.B. Lemon et al as inventors which in turn is based on GB 88299~4.7 filed 12122188 with the same inventors and both the U.S. and British cases are incorporated herein by reference.
It will be understood that the esterified phenolic compound used may be a mono-, a di-or a polyesterified methylolated mono-, di- or polynuclear phenol wherein at least one esterified methylol group is attached to an aromatic ring carbon atom ortho or para to a phenolic hydroxyl group or esterified phenolic hydroxyl group. The acid portion of the phenolic esters can be the same as those of the aliphatic esters.
Specific carboxylic acid esters include but are not limited to: n-butYI formate; ethylene glycol diformate; methyl and e~hyl lactates; hydroxyethyl acrylate; hydroxyethyl methacrylate;
n-butyl acetate; ethylene glycol diacetate; triacetin (glycerol triacetate); diethyl fumarate;
dimethyl maleate; dimethyl glutarate; dimethyl adipate; 2-acetyloxymethyl phenol; 2-methacryloyloxymethyl phenol; 2-salicyloyloxymethyl phenol; 2-acetyloxymethyl phenol acetate; 2,6-diacetyloxymethyl ~-cresol; 2,6-diacetyloxymethyl R-cresol acetate; 2,4,6-triacetyloxymethyl phenol; 2,4,6-triacetyloxymethyl phenol acetate; ~,6-diacetyloxymethyl phenol acetate; 2,2',6,6'-tetraacetyloxymethyl Bisphenol A; and 2,2',6,6'-tetraacetyloxymethyl 3isphenol A diacetate. Also suitable are: cyanoacetates derived from 1 to 5 carbon atom aliphatic alcohols; formates and acetates of benzyl alcohol, alpha,alpha-dihydroxyxylenols, phenol, alkyl substituted phenols, dihydroxyben2enes.
bisphenol A, bisphenol F, and low molecular weight resoles. At times, it is advantageous to use mixtures of the ester functional hardening agents.

Pag~ 15 .I.C.-~95 9123/90 Gaseous esters, such as C1 lo C2 ~Ikyl formates, can be used as ester functional hardening agents ;n low density articles or when applying the binders to fabric or paper substrates. Whe ~aseous es~ers are used as hardening agents, the ester is ~enerally not mixed with the resin ~inder and aggre~ate but rather is supplied as a ~as to the shaped article as is well known in the art.
The ester functional 'nardening agent is present in an amount sufficient to increase the ~ensile and Gompressive strength of the hardened composition. Such quantity aiso increases the rate of hardening of the phenolic resole resin in the presence of the magnesium hardener and will vary over a broad range such as that of about ~% to 40% by weight of the phenolic resole resin anci preferably from about 10% to 25% by weight of the resin. As with said rnagnesium hardening agent, the exact quantity will depend on the particular ester hardener used, the amount and specific magnesium hardener used, the temperature at which the composition is used or stored, and desired results.

The Phenolic Resole Resin A broad range of phenolic resole resins may be used in this invention. These can be phenol-formaldehyde resole resins or those wherein phenol is partially or completely substituted by one or more phenolic compounds such as cresol, resorcinol, 3,5-xylenol, bisphenol-A, or other substituted phenols and the aldehyde portion can be partially or wholly replaced by acetaldehyde, furaldehyde, or benzaldehyde. The preferred phenolic resole resin is the condensation product of phenol and formaldehyde. Reso~e resins are thermosetting, i.e., they form an infusible three-dimensional polymer upon application of heat and are produced by the reaction of a phenol and a molar excess of a phenol-reactive aldehyde typicaily in the presence of an alkali or alkaline earth metal compound as con~ensing catalyst.

R.l.C.-21 95 9/23190 Preferred phenolic resole resins used in this invention have less than about 1% and prsferably not more than 0.5% by weight of water soluble sodium or potassium. Typically, ~he phenolic resole resin will be a phenol-formaldehyde resin produced by reactin3 phenol and torrnaldehyde in a molar ratio (phenol: formaldehyde) within the range of from about 1:1 to 1:3. A preferred molar ratio for use in this invention ranges from about one mole of the phenol for each 1.1 rnole of the aldehyde to absut 1 mole of phenol for 2.2 moles of the aldehyde and particularly a range of phenol to aldehyde of 1 to 1.2 to 1 to 2. The phenolic resole resin will usuallly be used in solution.
The pH of the phenolic resole resin used in this invention will generally vary from about 4.5 to 9.5 with a pH oi absut ~ to 9 and particularly about 5 to 8.5 being preferred. Free phenol will typically be 2% to about 25% by weight of the resin with preferred levels being ~% to about 12%. The molecular weigh~ of the resin will vary from about 200 to 50ûO
weigh~ avera~e molecular weight with 300 to about 2000 being preferred. All other thlngs bein3 equal, higher molecular weights and lower free-phenol will provide shorter gel or hardening time and increase strength development. The weight average molecular weight ~Mw) is measured using gel permeation chromatography and phenolic compounds and polystyrene standards. The sample molecular weigh~ to be measured is prepared as ~ollows:
The resin samp!e is dissolved in tetrahydrofuran and slightly acidified with 1N hydrochloric or sulfuric acid and dried over anhydrous sodium sulfate. The salts which result are remoYed by filtration and the supernatent liquid run through a qel permeation chromatograph.
The resin solids in the resole resin can vary over a broad range, such as that of abou~
S0% to 90~~O by weigh~ of the phenolic resole resin. Preferably, the resin solids vary from about 50% to 80% by weight of the phenolic resole resin. The viscosity of the phenolic resole resin, or simply the resin, oan vary sver a broad range such as that of a~out 100 to Pag~ 17 R.i.C.-21 95 9/23190 4,U00 cps at 25'C. Preferably, the viscosity varies from about 200 to 3,000 cps at 25 C
snd partic~Jlary frorn about 250 to 2,û00 cps al 25 C. The viscosity measurements herein are ~iven In centipoises (cps) ~s measured by a Brookfield RVF viscomeler at 25 C or by Gardner-Holt viscosities at 25 C. The Gardner-Holt viscosities which are in centistokes are multipled by the specific gravity (generally 1.2) to give the cps at 25 C.
The quantity of resin based on a~gregate, when aggregate is used for the raw batch compositions, can vary over a broad range, preferably from about 3% to ~0% by weight of resin based on the weight of aggregate and particularly from about 5% to 15% of resin based on the weight of aggregate.
The liquid portion of the resin is water or water together with a non-reactive solvent.
The resin can include a number of optional modifiers or additives such as silanes, hexa, or urea. Solven~s in addition to water can be selected from alcohois of one to five carbon atoms, diacetone alcohol, glycols of 2 to 6 carbon atoms, mono~ and dimethyl or butyl ethers of glyGols, low molecular weight (200-600) polyethylene glycols and methyl ethers thereof, phenolics of 6 to 15 carbons, phenoxyethanol, aprotic solvents, e.g., ~LN-dimethylformamide, ~L,N dimethylacetamide, 2-pyrrolidinone, N-methyl-2-pyrrolidinone, dimethyl sulfoxide, te~ramethylene sulfone, hexamethylphosphoramide, tetramethyl urea, methyl ethyl ketone, methyl isobutyl ketone, cyclic ethers such as tetrahydrofuran and m-dioxolane, and the like.
~ ypical water contents for the resins used in this invention will vary from about 5% to 20% by weight of the resin and can thus be referred to as aqueous solutions.
Organofunctional silane adhesion promoters are recornmended for use when ~mpositions of this invention include siliceous aggregates, such as silir,a sands, crushed rock and silicates, and alumina based aggregates.

R. I. C.-21 9S 9123/90 The organofunctional silanes are used in a quantity sufficient to improve adhesion between the resin and aggrPgate. Typical usage levels of these silanes are 0.1 to 15% based on resin weight. Illustrative of silanes that are useful are those represented by the generic Formula 1.

~ormula l: (RO)3 Si- CH2 - CH2 - CH2 - X
where R - CH3, or C2Hs X = Cl, -NHR1, -O-CH2-CH-CH2, or ~SH

and R1 ~ H, CH3, C6Hs (phenyl), -CH2CH2N1~2, O O r~

-C-NH2, or - N -C-N-C-(-CH2)s H

Other useful silanes not represented by Formula I are 2-(3,4-epoxycyclohexyl)ethyl trimeihoxysiiane, bis(trimethoxysilylpropyl)ethylenediamine, .~L-trimethoxysilylpropyl-N,~,N-trimethylammonium chloride and secondary amino silane l(RO)aSi-CH2CH2CH2]2NH.

The Accelerators A wide ran~e o/ rr aterials have been found to be accelerators. Accelerating the hardening of the phenolic resole resin proYides for a shorter wait between the time the composition is mixed and when it is hard enough to use. Without the use of an accelerator, in R.l.C.-2195 lO/15/90-AA
,. ... .

many Instances the phenolic resole resin, magnesium hardener and optionally ester functional hardening agents. with or without fillers or aggregates will harden within 24 hours at 75-F
so that on bending or flexing a sheet or bar of such composition, the sheet or bar wiil break.
In case of ioni~able compounds, it is the anion. e.g., Cl-, which determines whether a material is an accelerator. Thus the cation, e.g., Na+,H+,Li~ does not change the anion from being an accelerator~ although it can have some effect on the amount of gelation or hardening.
Salts containing the following cations are particularly suitable in the accelerators of this a, r!~ invention: sodium; potassium; lithium; calcium;magnesium; ammonium; and lower alkyl substituted ammonium compounds such as those having from 1 to 4 carbon atoms in each alkyl group. The cations of the previous sentence as well as hydrogen, e.g., such as in nitric acid, are the preferred cations for accelerators of this invention. However, some compounds which do not appear to ionize are also accelerators.
The accelerators used in this invention have some solubility in the reaction medium. Such solubility can be different than that in water, particularly when the reaction medium contains substantial quantities of ester and less than about 15% water. For general purposes, however, the solubility in water of the accelerators is at least 0.1% and preferably at least 1.0% by weight at 25'C except for the reactive organic bound chlorine or bromine containing accelerators which are otten substantially insoluble in water. The accelerators can be in an aci~
form, e.g., hydrobromic acid, or in a salt form, as an acid addition salt of a basic nitrogenous compound or simply in a form which provides the accelerator anions when mixed with the phenolic magnesium hardener and optionally the ester. When the acid form is used in the presence of the magnesium hardeners, Ihe salt of the acid is formed in situ, e.g., the magnesium salt when added to a phenolic resole resin and hardener composition of this invention, the acid or salt provides the appropriate anion.

' J '' R.l.C.-2195 lo/15/go AA
, ,. I ~., The ionizable accelerators. e.g., those which provide chloride, sulfamate, etc. anions to the hardenable mixture appear to increase the solubility of magnesium or the quantity of soluble magnesium from the magnesium hardener in the hardenable mixture. This in turn accelerates the hardening of the phenolic. As stated hereinabove, the accelerator needs to have some solubility in the har~enable mixture. In this regard, the choice of the cation for combining with the anion of the ioni~able accelerator needs to be made so that the anion is not rendered insoluble. This also applies with the use of other materials which may insolLlbilize some of the accelerator anions such as acid addition salts of amines of the various calcium containing compounds which can be used together with the magnesium hardeners for hardening the phenolic resole resins. To avoid insolubilization, the accelerator anion needs to be one which is not insolubilized by such materials or the hardenable mixture needs to contain a high quantity of the accelerator anion so that sufficient anions remain for solubilizing the magnesium hardener.
Illustratively, when calcium is the cation of the accelerator compound or when calcium containing hardeners are used, the accelerator anion should be one which forms a water soluble calcium compound such as one having a water solubility of at least 1% by weight at 25 C.
In the case of compounds which dissociate in water or alcohols ~o provide anions, compounds providing the following anions are accelerators and appear to be effective by increasing the amount of magnesium in the aqueous solution of the magnesium hardener, phenolic resole resin, and other ingredients in the hardenable mixture: chloride, nitrate, sulfate, sulfite, bisulfite, bisulfate, sulfamate, phosphite, hypophosphite, cyanate, bromide, formate, and thiosulfate. Such accelerators increase the quantity of soluble magnesium in the hardenable mixture of phenolic, magnesium hardening agent and optionally ester hardening agent or other ingredients without addition of further magnesium oxide or magnesium hydroxide. The compound providing the anion accelerator can be in various forms such as the !, ,' R.l.C.-~195 10/1S/90-AA

acid, salt, amine acid addition salt or reactive organic bound chlorine or bromine containing compounds. In the case of amine acid addition salts, such salts should have a water solubility of at least 1% by weight at 25 C. By reactive organic bound chlorine or bromine containing ~ompounds, we mean materials which contain covalently bound chloride or bromide and which c l e ~ c react by solvolysis or ncuclc~pr,ill;c displacement with hydroxyl compounds such as water, alcohols, phenolic resins, or amines to liberate chloride or bromide ions, particularly in the presence of an alkaline material such as magnesium or calcium oxides or hydroxides.
Illustrative of compounds providing the accelerator in the acid form there can be mentioned: hydrochloric acid, phosphorous acid, hydrobromic acid, formic acid, hypophosphorous acid, sulfamic acid, and sulfuric acid.
Illustrative of salts for providing the anion accelerator, there can be mentioned: sodium chloride, potassium chloride, sodium bromide, lithium chloride, magnesium chloride, lithium carbonate, magnesium bromide, caicium chloride, ammonium sulfate, potassium bromide, potassium sulfamate, monosodium phosphite, choline formate, and the like.
Lithium carbonate is an accelerator which also improves the strength of the hardened resin composition, particularly after ~hermal cure. Lithium carbonate should be avoided when the composition contains water soluble calcium in a quantity greater than the quantity of lithium carbonate, due to possible decomposition of the carbonate by the water soluble calcium, e.g., such as in calcium oxide. Sulfamic acid and salts thereof are accelerators which also increase the strength of room temperature hardened phenolic resole resin compositions when ~he resin has at least about 10% of free phenol, e.g., 10 to 25% and relatively low molecular weight such as that of a weight average molecular weight (Mw) of about 150 to 500.

R l.C.-~195 '0/15/90 AA

lliustrative of reactive organic bound chlorine or bromine containing accelerator compounds, there can be mentioned: cyanuric ehloride (2,4,o-trichloro-~,-triazine); 2,4-dichloro-6-n-propoxy-s-triazine; 2,4-dichloro-6-anilino---triazine; 2,4-dichloro-6-o-~ I I S ~t~chloroanilino-s-triazine; methanesulfonyl chloride; ~ trichlorololuene; and 2,3-dibromopropionitrile. Additional reactive organic bound chlorine or bromine containing compounds include: epichlorohydrin, epibromohydrin, 2,4-dichloro or dibromo-6-substitutet ~-triazines such as wherein the substituent is alkoxy or aklylamino of 1-6 carbons, aryloxy and arylamino of 6-lû carbons, and other heterocyclic polychlorides, e.g., 2,~-dichloropyrimidine; dichlorodiphenyl silane, silicon chlorides or bromides such as silicon tetrachloride, silicon tetrabromide, phenyl trichlorosilane, 1,3-dichloro-1,1,3,3-tetramethyl disiloxane; other carbon-chlorine or bromine compounds such as allyl, benzyl and cinnamyl chlorides, 1,4-dichloro-2-butene, methyl 2-chloroacetoacetate, 1,4-dibromo-2-butene, 2,3-dichloropropionaldehyde, 2,3-dichloropropionitrile, ~ -dibromoxylene, ~,~l-dichloroxylene, 2-chloromethyl-m-dioxolane, and acid chlorides, e.g., acetyl chloride, pivaloyl chloride, benzoyl chloride, isophthaloyl ct~loride, terephthaloyl chloride, and sulfur-chlorine compounds, e.g., benzene and toluene-sulfonyl chlorides. 1,3-benzene disulfonyl-chloride, and methanesulfonyl chloride. Additionally, compouds which liberate accelerator anions or compounds such as hydrogen chloride in water or alkanols such as dichlorophenylphosphine are operable.
b~S t~
Q ~//d~ Additionally, certain strongitertiary amines are accelerators. Illustrative of such accelerators, there can be mentioned 1,3,5-tri(lower alkyl) hexahydro-1,3,5-triazines wherein the lower alkyl has from 1 to 3 carbon atoms; 1,4-diazabicyclo[2.2.2.1octane which is Pag~ 23 R. I C -2195 l O/1 5/90-A
,,; " ~

commonly referre~d to as ~riethyl~ne diamine; 2,21-bipyridine: 1,1,3,3 tetra lower alkyl of 1 to 3 carbon a~oms guanidine; 2,4-di(lower alkylaminomethyl)phenol, 2,6-di(lower alkylaminomethyl)pllenol, and 2,4,6-tris~dilower alkylaminomethyl)phenol wherein each alkyl group has from 1 ~o 3 carbon atoms; and a compound of the formula:

~1 R3 N - X - N

wherein:
( i ) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to about 3 carbon atoms, and R1and R2 when taken together with the nitrogen to which they are attached represent a rnember selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
( ii) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2-, -CH2-CH=CH-CH2, and -CH2-CH2-fH-, -CH2-fH-C112-;

and ( i i i ) each of R3 and R4 is a member selected from the group consisting of hydrogen. alkyl of 1 to about 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino~ Acid addition salts o~basic~accelerators, wherein Ac~lel~r --o. ~ r ~ .v, ~ ~h~h ~s ~ r~t~ ef the acid includes one of the previously mentioned~Janions~às well as lithium carbonate, provide o ~ r ~ t r~ f~ r~l ' beneficial accelerator compounds.
r~ c~)/cro~ 6~a~ /f~v~
r~ r7~,f~"f a~
b~ ~e~v~ ~h~f~Pf fhe ~'~
~',4R 6 Oh~ A fc~ o or ~; 7~r~ .

j i. '.' ,', R.l.C-2195 10/15/90-AA

S~ill another group of accelerators are certain chelating agents, such as:

heptane-2,4-dione; pentane-2,4-dione, also referred to as acetylacetone; 2,21-bipyridine;
benzoylacetone; 2-acetylcyclopentanone; and 2-formylcyclopentanone.
The quantity of accelerator used in this invention can vary over a wide range depending on the activity of the particular accelerator, the amount of acceleration desired, the room or ambient temperature, the surface area and quantity of the lightburned magnesium oxide, and the type and quantity of ester hardener. Thus, the quantity of accelerator sufficient for hastening the gelation and hardening of the phenolic resole resin can vary over a broad range such as that of from about 0.1% to 5% by weight based on the weight of the phenolic resole resin.
Preferably, the quantity of accelerator is from about 0.5% to 5% and, particularly, from 1.0%
to 5% by weight of the resin. Chlorides can be effective accelerators by use of as little as 0.1%
by weight, based on the resin but higher quantities of the other accelerators are generally required.

Fillers. Aa~reoates. and Modifiers The compositions of this invention can include fillers, modifiers, and aggregates which are conventionally used with phenolic resole resins. The aggrega~e material may be a particulate material such as that in granular, powder, or flake form. Suitable aggregate materials include but are not limited to: magnesite, alumina, zirconia, silica, zircon sand, olivine sand, silicon carbide, silicon nitride, boron nitride, bauxite, quartz, chromite, and corundum. For certain applications, low density aggregate materials such as vermiculite, perlite, and pumice are Pag~ 25 .I.C.-219~ 1 0/15/90-A

preferred. For other applica~ions. preferable high density aggregates include: limestone, quartz, sand, gravel, crushed rock, broken brick, and air cooled blast furnace slag. Sand, gravel, and crushed rock are preferred aggregates in polymeric concrete. Fillers such as calcium carbonate, kaolin, mica, wollastonite, and barites can be used in quantities of up to about ~0% by weight of the formulated resin product. The quantity of such fillers can equal the quantity of the resin. Hollow microspheres of glass, phenolic resin, or ceramic can also be used in quantities of up to about 20% of the formulated resin product. Other optional modifiers, particularly in polymer concrete, include fibers such as steel, alkali resistant glass, polyester, carbon, silicon carbide, asbestos, wollastonite fibers, and aromatic polyamides such as KELVAR~ aramid fiber which is sold by DuPont, and polypropylene. The quantity of such fibers can vary over a wide range sufficient to improve the strength of the composition, e.g., from about 2% to 5% by weight of aggregate when aggregate is used in the composition.
The raw batch compositions produced by combining the hardenable resin binder, aggregate, hardening agent or agents, and accelerator may additionally comprise any of a number of optional modifiers or additives including non-reactive solvents, silanes, hexamethylenetetraamine, clays, graphite, iron oxide, carbon pitch, silicon dioxide, metal powders such as aluminum, magnesium, silicon, surfactants, dispersanls, air detraining agents, and mixtures thereof. Air detraining agents such as antifoamers, e.g., dimethylpolysiloxane and the like, can be employed in an amount sufficient to increase the strength of the composition. Such quantities can vary over a broad range such as from about 0.005% to 0.1% based on the weight of resin and preferably from about 0.01% to 0.05%
based on the weight of resin. Illustrative of additional air detraining agents there can be mentioned: various acetylenic derivatives such as the Surfynols of Air Products and Chemicals, Inc. such as Surfynol DF-110L, Surfynol 104, and Surfynol GA; and various siloxanes such as Pag~ 26 C J . 'j~ R . I . C . - 2 1 9 5 1 0/ 1 5/9 0 A

dimethylpolysiloxane and dimethylsiloxane-alkylene oxide block copolymer such as PS073 which is supplied by Huls Petrarch Systems.
In foundry applications and sand-binder overlays, or where silica sand is used as the aggregate, a preferred additive is a silane adhesion promoter, such as gamma-aminopropyl triethoxysilane. In refractory applications, clays, metal powders (e.g., aluminum, magnesium, or silicon), and graphite are preferred additives. When graphite or metal powders of aluminum, magnesium, or silicon or mixtures thereof are used as additives, the amount of aggregate, such as alumina or magnesia, can be reduced to as low as about 70% by weight of the composi~ion.

Ao~lications The methods and compositions of this invention are particulary useful in: preparing shaped articles such as bonding refractory aggregate for the manufacture of bricks and castable monolithic shapes; coated abrasives; polymer concrete, also referred to as resin-filled aggregate, for repair or protective overlay for concrete lo provide resistance to acids, oils, and organic solvents; manufacture of precast shapes such as pipe, tile, wall panel, and the like, where hydrolytic, solvent, acid, and heat resistance are desirable; and impregnated paper for use as auto oil and air filters.
Refractory shaped articles include refractory brick and monolithic refractories. The conventional refractory compositions contain: a hardenable phenolic resole resin; magnesium hardening agent; aggregate; and optionally ester functional hardening agent, metal powders and graphite. Aggregates normally used for refractories are: magnesia (periclase);
alumina; zirconia; silica; silicon carbide; silicon nitride; boron nitride; bauxite; quart~:

, . R.l C.-2195 10/15/90 corundum; zircon sand; olivine sand; and mixtures thereof. Preferred aggregates for refractory use are refractory magnesia, also referred to as periclase, alumina, and silica. The ~moun~ of graphite generally varies from about ~% to 25% by weighl of the refractory aggregate and the quantity of metal powder such as aluminum, magnesium, and silicon ~vill generally vary from about 1% to 5% by weight of refractory aggregate. In the case of refractories such as brick, the refractory composition Is pressed into the desired shape and thermally cured or, after pressing, the composition is allowed to harden at ambient temperature and then thermally cured.
In some refractory applications, prefabricated forms, other than brick-like shapes, are required. These ~monolithic refractories~ are cast by placing a liquid flowable binder-aggregate system into a mold and then filling out the mold by using vibration. Once the binder-aggregate system room temperature hardens, the mold is stripped away so that the shape can be thermally cured and readied for use, either before or after transporting the monolithic refractory to its place of use.
Hydraulic refractory calcium aluminate cements constitute the current binder technology for monolithic refractories. However, chemical interaction between molten metal such as iron, steel, and aluminum and hardened cements create problems such as dissolving, softening, or simply weakening hydrated cement phases which in turn increase permeability of the hardened refractory shape. This, in turn, severely limits the service life of the refractory shape. After room temperature hardening, the monolithic can be thermally cured or carbonized, preferably at the site of use such as part of a fumace lining. Carbonizing takes place at temperatures above Bû0'C or 1,00û C.
Polymer concrete is formed by polymerizing a monomer, resin, or mixture thereof in the presence of an aggregate. Polymer concrete had its initial application in the repair of Pag~ 28 R l c.-2ls5 10/1s/so Portland Cement concrete. Today, they have many other uses as described herein above.
The binder compositions of ~his invention are particularly advantageous for this use since the iack of high alkalinity and high sodium or potassium levels does not affect the aggregate and the composi~ion can cure at room or ambient temperature in a reasonable time indoors or outdoors.

Pag~ 29 R. I . C .-2195 10/1 5/9o . , ,., ''/

One use for the compositions of this invention is as coating or topping applied to a rigid surface such as concrete. Thus, a room temperature curable flooring composition is provided comprising a resin binder and aggregate system prepared as described above. Aggregates for the overlay ~oating can be selected from low or high density materials or mixtures thereof. The small amounts of sodium or potassium ions present in the preferred compositions of this invention from the preparation are not sufficient to produce adverse effects on concrete.
A preferred use for the oompositions of this invention are for shaped articles wherein the article is cast and permitted to harden at room or ambient temperatures and is then thermally cured.
In order that those skilled in the art may more fully understand the invention presented herein, the following procedures and examples are set forth. All parts and percentages in the examples, as well as elsewhere in this specification and claims, are by weight and temperatures are in degrees Fahrenheit unless otherwise stated.

R.l.C.-21ss 10/15/90 Procedure For The Preparation And Testin~ Of Polymer Concrete For Compressive Stren~th A ~-quart Hobar~ mixer was charged with - 990.0 9 Industrial Grade Sand No. 4 (Vulcan Materials Co.) This is also referred to herein as coarse sand.
360.0 9 Industrial Grade Sand No. 10 (Vulcan Materials Co.) This is also referred to herein as medium particle size sand.
150.0 9 Oklahoma Mill Creek Foundry Sand (U.S. Silica) This is also referred to herein as fine sand.
and 22.5 9 Magchem 50 (65 square meters per gram) a lightburned magnesia from Martin Marietta Magnesia Specialties.
180~0 9 of Resin A containing 1.8 9 silane, namely 3-,glycidoxypropyl trimethoxysilane, was added. The resin-aggregate was mixed for a total of 2 minutes (at medium setting for 1 minute and high setting for 1 minute) then 45.0 9 of y-butyrolactone and 15.0 9 water were added and mixing continued for 1 minute at medium setting and an additional 1 minute at a high setting.
The mixture was then transferred to a mold containing 15 cylindrical cavities of 1-1/2" depth and 1-1/2~ diameter. Each cavity was lined with thin polyester film to ease removal of hardened specimens. The charged mold was then vibrated for 2 minutes at a setting of ~.1 using a Syntron Vibrating Table. Surfaces were lightly troweled and the molds then transferred to a constant temperature (72'F +l~ 2-F) and humidity (~1% +I- 2%) room. Hardened specimens were removed from the mold after 2~ hours and either tested or stored for evaluation at a later date. Compressive strengths for polymer concrete were determined on a Tinius Olsen Pag~ 31 , ,~ R l.C. 2195 1c/1stso ,' . J ~

tensile tes~ machine at a slow speed of 0.15 inches/rninute. Pounds to failure divided by 1.77 represents compressive strength in psi.

Proccdure For The Preparalion and Testin~ O~ Polymer C:oncrete ~or Tensile Strength A 5 quart Hobart mixer was charged with 891.0 9 Industrial Grade Sand No. 4, 324.0 9 Industrial Grade Sand No. 10, both from Vulcan Materials Co., 135.0 9 Oklahoma Mill Creek Foundry Sand (U.S. Silica), and 13.5 9 Magchem 50 (Martin ~arietta Magnesia Specialties).
To this mixture, was added 162.0 9 of Resin A containing 1.62 g (grams) silane namely

3-glycidoxypropyltrimethoxy silane. The resin/aggregate mixture was mixed 2 minutes, one at medium speecl and one at high speed. This mixture was then transferred ~o aluminum forms (pre-sprayed with release agent) and cast to form dogbone specimens 3 inches long, 1 inch thick and 1 inch wide at the neck. The sprayed forms had been previously placed on polyester film atop an aluminum tray. Dogbone molcls were filled and vibrated for 2 minutes at a setting of 5.1 on a Syntron Vibrating Table. The surfaces were lightly troweled and then the assembly transferred to a constant temperatLIre (72-F ~/- 2'F) and humidity (51%
~/-2%) room and allcwed to harden. After 24 hours, samples were removed from molds and either tested or stored for evaluation at a later date. Tensile strengths were determined on a Tinius Olsen tensile test machine at a slow speed of 0.15 inches/minutes. Readings in psi are indicated on digital readout.

' ' C'~
, .., ;. . R. I c.-21 95 1 C/1 s/so Determir)ation of Soluble Magnesium From Reaction of Resin A & Magnesia Hardener with/without Ester Hardener and with/without Additi~re A glass screw cap vial (28x95mm) was charged with 6.0 9 Resin A
0.5 9 water 1.5 9 ~-butyrolactone (or 2-methoxyethyl ether, as indicated in the Examples or Tabies herein), which was briefly mixed to homogenize the solution whereupon 0.75 9 lightburned magnesia (Magchem 50; Martin Marietta Magnesia Specialties) was added. The mixture was thoroughly mixed tor 1 minute using a S/P Vo~ex Mixer (American Scientific Products) at a setting of 9.
1.5 9 of the uniform dispersion was immediately transferred to a vial containing 4.5 9 ~L.N-dimethylformamide (DMF) and O.S g methanol. After mixing well for ~ minute, the conten~s were transierred to a centrifuge tube which was centrifuged for 5 minutes. The reiativeiy ciear liquor was fiitered through a teflon microfilter. A weighed amounl of ciear solution was ashed in a platinum dish which was hea~ed a~ 600'C in a muffle furnace. The residue was treate~ with aqueous hydrochioric acid, diluted ap?ropriately, and anaiy~ed for magnesium by atomic absorption.
The above freshly mixed soiution/magnesia dispersion (1.5 9 per vial) was transferred to other empty vials which were piaced in a 25 C water bath. At appropriate iimes, 4.5 9 DMF
was added and, after 2 to 3 minutes of mixing, compiete dispersion of resin was achieved. Then û.5 g methanol was added, remixed, and then centrifuged and anaiyzed as described above. %
Magnesium in original sample = % magnesium found x 4.27 factored to correct for solvent dilution .

~.I.c.-21ss 1o/1s/so Flow Determination of Resin/Hardener/~Aagnesia/Aggregate ~IAix A dome shaped 150 ml glass bowl 3" wide and 2~ deep is lightly sprayad with release agent and charged, in 3 portions, with composi~e mix derived from resole, ester hardener, lightburned magnesia hardener, and aggregate (silica sands or refractory dead burned magnesias). The composite mix is gently tapped in place with a pestle after each addition.
The bowl and contents are inverted onto polyester film taped to a Syntron Vibrating Table.
The table is then vibrated for 20 seconds at a setting of 8 (3/4 of maximum setting). The diameter ~in inches) of the resulting hemisphere is measured and % flow calculated by:
(Diamater measured - 3.0) x 100 3.0 Procedure For Gel Determination A screw cap glass vial (28x95mm) is charged with: 6.0 grams Resin A or Resin B (as indicated in the Tables or Examples); additives if any, as indicated in Tables or Examples; 0.5 grams water; and 1.5 grams (9.) gamma butyrolactone. The solution is mixed well prior to addition of 0.7~ 9 of lightburned magnesia having a surface area of 65 square meters per gram. The mixture is thoroughly mixed ~or one minute using a S/P Vortex Mixer of American Scientific Products at a setting of 9. Five grams (g) of this mixture is immediately transferred to a glass test tube (18xl55mm). A glass rod with a magnetized head fitting is introduced into the mixture and fitted to a Sunshine Gel Time Meter which is then turned on.
The tube is immersed in a 25 C water bath throughout the test.

R.l.C.-2195 10/15/90 ,; 'J ~

Determination of gel Rmes with Resin C used 5.0 9 of mixture derived from 8~0 9 of Resin C, 1.2 9 gamma-butyrolactone and 1.6 9 of the lightburned magnesia having a surface area of 65 square meters per gram Solvents were optional. Gei determinations were run at 25'C or at 60'C (boiling chloroform).
- 100'C gel times with Resin D used 5.0 9 of a mixture derived from 8.4 9 Resin D, 0.0081 ester equivalents of organic hardener, 2-methoxyethyl ether and 0.16 9 of lightburned magnesia having a surface area of 25 square meters per 9. The weight sum of ester hardener and 2-methoxyethyl ether was kept constant.
Gel times with resin E used 3.85 9 resin and 1.16 9 of ethyl lactate or 4.0 g Resin E and 1.0 9 Triacetin.

Phenolic Resole Properties Phenolic Resole Resin E is a commercial product sold as Alphaset 9,000 by Borden Chemical Company. Resin E is not a resin used in this invention except for comparison purposes. This resin has approximately 50% solids, ~0% water, a viscosity of 150 cps at 25 C, and a pH of 13.
Phenolic Resole Resin A, or simply Resin A, is a phenol formaldehyde resole resin prepared by reacting phenol (P) with 50% formaldehyde (F) at a F/P molar ratio of 1.25 using sodium hydroxide as catalyst and then further formulated. This resin intermediate is formulated with acetic acid, ethanol, methanol, and N,N-dimethylformamide (DMF) to provide Resin A which has: a Gardner-Holt viscosity at 25'C, of 2,560 Centistokes, or approximately 3,000 cps at 25 C; 68% solids; 7% free phenol; 10% lower alkyl alcohols; 12% water; 4%
DMF; a pH of 5.9, and a weight average molecular weight of 4,000.

Page ~5 R.l.C.-2195 10/15/9~

Phenolic Resole Resin B, or simply Resin B, is a more alkaline, water dilutable analog of Resin A without the acetic acid, and ~I,N-dimethylformamide (DMF), but instead formula~ed with ethanol to provide a 7.5% ethanol conten~ and potassium hydroxide 0.75~/O based on Resin B
to provide a pH of 8.9 to the final resin solution as well as a weight average molecular weight of ~,OOû and 67% solids, 18% water, and 7% free phenol, all based on the weight of resin (B.O.R.).
Phenolic Resole Resin C, or simply Resin C, is prepared by reacting phenol (P) with 50% formaldehyde (F) at a F/P molar ratio of 1.25 using sodium hydroxide catalyst. This resin has a viscosity of 250 cps at 25 C; 68.6% solids B.O.R.; 15.7% free phenol B.O.R.;
11.7% water B.O.R.; a pH of 8.9 and a weight average molecular weight of 290.
Phenolic Resole Resin D, or simply Resin D, is prepared by reacting phenol (P) with 50% formaldehyde (F) at a F/P molar ratio of 2.0 using potassium hydroxide catalyst. This resulting intermediate resin has a weight average molecular weight of 390 and is formulated with phenol and Dowanol DPnB (dipropylene glycol monobutyl ether-Dow Chemical) to give the final resin having: solids of 78%; ~ree phenol of 16%; water of 8%; Dowanol DPnB of 8%;
potassium of 1.3%; a pH of 9.2; and a viscosity at 2'i'C of 3450 cps.

Pag~ 36 R.l.C. 2195 l(~ YU
3 , l !
, i . J i~
EX~MP~E 1 In this example, various additives were tested at 2%, based on resin weight (B.O.R.), unless indicated otherwise, for their effect on the rate of hardening of the phenolic resole resin in the presence of bo~h magnesium hardener and ester hardener at about 25 C. The rate of hardening was determined by measuring time of gelation in accordance with the hereinabove procedure entitled "Procedure For Gel Determination.~ The resin employed was Resin A, the ester was ~butyrolactone, and the magnesium hardener INas Magchem 50. The control for Table 1 was the composition without additive which gave a gel time of 48 minutes. Also, for a lower molecular weight analog of Resin A, which is indicated on Table 1 with the superscript ~(a)", the composition without additive gave a gel time of 67 minutes. Thus, gel times of less than 48 minutes, wherein the time is not followed by the superscript a(a)," of the various additives denote accelerators whereas get times of more than 48 minutes, wherein the time is not followed by the superscript ~(a),~ denote retarders. The results of this example are shown in Table 1. Some of the more significant results shown in Table 1 are as follows.
The chlorides are the most effective accelerators. Organic chlorine or bromine containing materials that react with water or alcohols at about 25 degrees C at pH of about 5 to 9 to liberate chloride or bromide ions act as reactive accelerators. Fluoride and bifluoride salts are retarders. Phosphoric acid and salts thereof are effective retarders. Surprisingly, related materials such as phosphorous acid. sodium phosphite, and hypophosphorous acid are accelerators.

Pag~ 37 R. l. C .-2195 10/15/go Effec~ of Additives on Gel Time of Resin A / y-Butyrolactone/Ma~tnesia Hardener Syslem: 6.0 9 Resin A 1.~ 9 y-Butyrolactone 0.5 9 water 0.75 Lightburned Magnesia having surface area of 6~ square meters per gram (65m2lg) Mix Additive (2% on Resin) Gel Time. Min. (25'C) (Unless otherwise indicated) Inorpanic None 48 67(a) 62(a)(b) 2 Ammonium Bifluoride (0.5% B.O.R.) 148 241(a)(b) 3 Ammonium Chloride 7

4 Ammonium chloride (0.33% 8ØR.) 28 Ammonium Fluoride 128 6 Ammonium Nitrate 33 7 Ammonium Phosphate Monobasic 85 8 Ammonium Sulfate 23 9 Ammonium Sulfite 32 Calcium Chloride 19 11 Calcium Formate 45 12 Choline Chloride 25 13 Choline Formate 37 14 Hypophosphorous acid 40 (a) Lithium Carbonate 36 16 Lithium Fluoride 61 17 Lithium Nitrate 17 1 8 Lithium Sulfate 34 19 Magnesium Chloride 6 Magnesium Oxalate 56 21 Magnesium Sulfa~e 44 22 Meta phosphoric acid/mono sodium metaphosphate, 1:2 74 Paga 38 ~ ;J 1~ ~; R.l.C.-2195 10115/90 Table 1, Continued kli~Additive ~2% on Resinl Gel Time in Minutes at 25 C
(unless otherwise indicated) 23 Phosphoric Acid 107 24 Phosphorous Acid 19 Potassium Cyanate 37 26 Potassium Fluoride 126 27 Potassium lodide 39 2 8 Potassium Sulfamate 16 29 Sodium Bromide 30 Sodium Carbonate 55 31 Sodium Chloride 12 3 2 Sodium Bisulfate 3 6 33 Sodium Bisulfile 26 34 Sodium Dithionite 42 Sodium Fluoride 174 36 Sodium Hydroxide (1.4% B.O.R.) 4û
3 7 Sodium Nitrate 2 9 3 8 Sodium Nitrite 4 6 39 Sodium Phosphate, Monobasic 90 4û Sodium Phosphate, Tribasic 77 41 Sodium Phosphi~e, Monobasic 31 4 2 Sodium Silicate 4 7 43 Sodium Sulfate 22 44 Sodium Thiosulfate 20 QrqaniC
Acetic acid 4 5 2 Acetoguanamine (2,4-diamino-6-methyl-s-triazine) 6 0 3 Acetylacetone (pentane-2,4-dione at 3% B.O.R~) 39 (a) 4 Aminoacetic acid (glycine) 65 ? R.l.C.-2195 10/15/90 Table 1, Continued kli~ Additive (2% on Resinl Gel Time in Minutes at 25-(~
(unless othsrwise indicated) Aminoacatic acid (glycine) 65 6 Q-Aminobenzoic acid 108 (a) 7 3-Aminopropionic acid (13-alanine)66 8 Aminotri(methylenephosphonic acid) 68 9 Aspartic Acid 104 Ben70guanamine (2,4-diamino-6-phenyl-s-triazine) 49 1 1 2,3-8utanedione (Biace~yl) 75 (a) 12 Chloroacetamide 52 13 Citric Acid 193 14 2,3-Dibromopropionitrile 40 2,4-Dichloro-6-n-propoxy-_-triazine 22 16 2,4-Dichloro-6-o.-chloroanilino-~-triazine 26 17 Dichlorodiphenyl silane 24 18 a,a-Dichlorotoluene 4 6 19 Diethyl phosphita 5 1 Q,R-Dim9thylaminomethyl phenols59 (a~
,,qO DMP-10 of Rohm &+~ Co.
21 EDTA ''~Ap?~ 73 22 Guanidine Hydrochloride 24 23 Glutamic Acid ~ 76 2 4 Glycolic Acid 4 7 2 5 Haxachlorocyclopentadiene 4 9 2 6 Hexamethylenetstraamine 4 4 27 1-Hydroxyethylidene-1, 1-diphosphonic acid 63 2 8 Imidazolo 5 6 2 9 Iminodiacetic acid 1 03 3 0 Malic Acid 118 31 Malonic Acid 55 3 2 h~elamine 6 6 3 3 Methanesulfonyl Chloride 2 2 R.l.C.-2195 10/15/90 TLtble 1, ~:ontinued ~L~ Additive (2% on Resin)Gel Time in Minutes at 25'C
(unless otherwise indicated) 34 Mathyl 2,3-dichloropropionate 43 3 5 N-methyl imidazole 4 8 36 Oxalic Acid 86 3 7 Phenyltriethoxy siiane 5 7 38 Succinic acid 41 3 9 Tartaric Acid 1 4 0 4 0 Terephthalic acid 5 6 41 Tetraethoxy Silane >276 42 Tetraethoxy Silane (4% B.O.R.) 327 43 Tetraethoxy Silane (0.5% B.O.R.) 92 4 4 Tetraethoxy Silane (40% hydrolyzed) at 0.5% concentration B.O.R. (Silbond 40 of Akzo Chem., Inc.) 90 Tetra n-butylammonium chloride 38 46 ~L,N.N1,N1-tetramethYI-1.3-propane diamine 40 (a) 47 Alpha, Alpha, Alpha-trichlorotoluene 35 4 8 Triethylene diamine, i.e., 1 ,4-diazabicyclo ~2.2.2I octane 3 9 4 9 Alpha, Alpha, Alpha-trifluorotoluene 4 9

5 0 Trimethyl Borate 4 6 51 Trimethyl Phosphite 5 3 52 2,4,6-Tris(dimethylaminomethyl)phenol 35 (a) Resin having a weight average molecular weight of about 3,000 whereas the resin for the other detarminations had a weight average molecular weight of about 4,000.
(b) 0~759 lightburned magnesium oxide having a surface area of 10 m2/g used in addition to 0.75 g lightburned magnesium oxide having a surface area of 65 m2/g.

R.l.C. 2195 10/15/90 FXAMPI FS 2 ANC) 3 In these examples, tests were run to determine the effect of lightburned magnesia or magnesium hydroxide, esters, and additives on the compressive strength of polymer concrete.
These examples were run in accordance with the Procedure For The Preparation and Testing of Polymer Concrete set forth hereinbefore.
For the polymer concrete data shown in Table 2 and 3, the compressive strengths were de~ermined, unless specified otherwise, on room temperature (R.T.) cured specimens using Resin A, ~-butyrolactone as ester, lightburned magnesia or magnesium hydroxide as the alkali, and mixture of silica sands as aggregate.
It can be seen in Table 2 and Table 3 that:
( a ) Fluoride re~arder lowers R~T. strength after 24 hours, but this relative effect is more dramatic afler 8 hours when compared to control. Lithium carbonate and calcium formate increase 1 day R.T. strength, but lithium fluoride (very low solubility) has no effect.
( b ) Replacement of magnesia by a chemical equivalent of magnesium hydroxide leads to a dramatic decrease in compressive strength. However, magnesium hydroxide responds to accelerative and retardative effects. Chloride increases 24-hour R.T. compressive slrength whereas fluoride decreases strength.
c ) Replacement of y-butyrolactone ester by an eclual weight of inert high boiling solvent (a glycol diether) leads to a dramatic reduction in 3 and 7 day R.T. strength. Four day immersion in 10% acetic acid, after a 3 day dry R.T. cure, leads to a strength decrease relative to a 7-day dry R.T. cure. With butyrolactone, an increase in strength is seen after the acetic acid treatment.

R.l.C.-2195 10/15/90 (d) Four day hot (90 C) water immersion preceded by 3 day dry R.T. cure of concretes prepared using ~-butyrolactone and lightburned magnesia leads to significantly higher strength than systems where inert solvent replaces ester or where magnesium hydroxide replaces magnesia.
( e ) Sulfamates which are good accelerators show a negative effect on strength (8 or 24 hours) with Resin A. However, sulfamates show improved strength with low molecular weight resins and high free phenol contents, e.g., 10% to about 2~% of free phenol based on the weight of resin, as can be seen in Example and Table 10 herein. Moderate accelerator Li2CO3 shows a 24% strength increase after 24 hours.

R. l. C.-2195 10/15/90 Polymer Concrete Usinçi Resin "A"
Effect of Alkali and Ester Mix: 36 9. Resin per 300 9. sand mixture Diglyme or y-Butyrolactone (25% B.O.R.) Water (8.3% on resin) Alkali source (magnesia or magnesium hydroxide hardener) Epoxy Silane, 3-glycidoxypropyltrimethoxy silane, (1% on resin) Compressive Siren~th. psi (Average of 3) 3 Days R.T. Dry + 4 Days Wet Immersion 3 Days 7 Days R.T. R.T. H20/ H20/ 10% Acetic Mix Drv Drv R.T. 9Q'C Acid R.T.
1. Diglyme (a) 437 777 669 3423 611 (25% on resin) Lightburned Magnesia of 65 m2tg (12.5% on resin) 2. r-Bulyrolactone 2962 3704 3546 4893 3934 (25% on resin) Lightbumed Magnesia of 65 m2/g (12.5% on resin) 3. ~-Butyrolactone 587 1628 1601 3245 1628 (25% on resin) Magnesium Hydroxide (18% on resin) (b) (a) Diglyme = (2-methoxyethyl)ether, inert solvent (b) Equivaient to 12.5% Lightburned Magnesia Oxide Effect of Addltlves on Compressive Strength Uslng ~-Butyrolactone (Ester) With Magneslum Hydroxlde as Alkall Hardener Additive (~/0 on Resin) 24 Hr. R.T. Comp. Str.. psi ~average of 3 None 1 67 NH4CI (2% B.O.R.) 214 NH4F (2% B.O.R.) 47 .. ., .~ R.l.C-2195 10/15/90 Polymer Concrete Usin~ Resin A - Effect of Additives on Compressive Strength Mix: Resin A (36 9 per 300 9 sands) ~agre~ate:
~-Butyrolactone (25% B.O.R.) Mixture of 3 sands:
Magchem 50 (12.~% B.O.R.) (MgO) 198 g coarse Water (8.3% B.O.R.) 72 g medium Epoxy silane, namely, 3-glycidoxypropyl- 30 9 fine trimethoxy silane (1% B.O.R.) Room Temp. Comp. Str............ psi (average of 3) Additive ~% on resin) 8 Hrs. Hardening 24 Hrs. Hardenin~
Nono (control) 477 NaF (at 2% B.O.R.) 168 Sodium Sulfamat~ (at 2% on Resin) 393 Control 1 390 NaF (at 2% B.O.R.) 1103 Sodium Sulfamate (at 1% B.O.R.) 1110 Control 1 353 Li2C03 (at 2% B.O.R.) 1781 LiF (at 2% B.O.R.) 1315 Calcium Formato (at 2% B.O.R.) 1520 In addition to the above Table 3, deadburned pulveri2ed periclase was used by substituting about 18% of the periclase in place of the 12.5% Magchem 5C in the mix of Table 3. Without a retarder, the mix with periclase showed a 24-hour compressive streng~h, psi of 105, and with a 2% addition of ammonium fluoride, the mix remained soft after 5 days at room temperature.
The periclase was 98.1% MgO on an ignited basis with a bulk specific gravity of 3.28 having 95% passing through a 5û U.S. Sieve Series screen and 75% passing a 200 U.S. Sieve Series screen.

Pago 45 R. l. C. -2 1 9s l o/1 s/so In this example, tests were run ~o determine the effect of surface area of the lightburned magnesia hardener on gel time. The composi~ions tested were 6.0 9 (grams) Resin A; 0.5 9 water; 1.5 9 of ~butyrolactone and 0.75 9 of magnesia hardener of different surface areas. The results are shown in Table 4. It can be seen from Table 4 that gel time is a function of magnesia surface area and concentration with the higher surface areas or concentrations decreasing the gel time.

R.l.C. 21ss 10/15/90 Effect of Magnesia on Gel Time of Resole-Ester-Ni3~nesia Hardener System: 6.0 g Resin A 1.5 9 y-Butyrolactone 0.5 9 water 0.75 9 (grams) Lightburned Magnesia (MgO) ~i~Surfa~e Area of M~O m2/g Gel Time Min. at 25'C
(square meters per gram) 3(a) 6 5 9 9 (a) 1/2 quantity of MgO used.

Pag~ 47 EX~MPLE 5 This exam~le was performed to show the effect of additives which were previously shown 10 be accelerators or retarders at the 25 C room temperature (R.T.) hardening on the solubilization of magnesium in the reaction mixture. The example was run in accordance with the ~Procedure For 3etermination of Soluble Magnesium From Reaction Of Resin A & Magnesia Hardener With/Without Ester Hardener And With/Without Additive~ which is set forth hereinabove. The results are shown in Table 5. The percentage readings of B.O.R. following the additive are percentages of the additive based on resin weight (a.O.R.). It can be seen from Table 5 that chloride increases magnesium solubilization and fluoride decreases solubilization in the reaction mixture. A similar effect is seen without ester in mixes 4-6 wherein the ester is replaced by inert solvent 2-methoxyethyl ether. The chelating agent, pentane-2,4-dione also increase magnesium solubilization.

Pag~ 48 R . I . C . -2 19 5 10/1 S/9 0-A

TABLE ~J
Effect of Additives on Solubilization of Magnesium System: ResinA 6.0 9 y-Butyrolactone (or inert solvent) 1.5 g Water 0.5 g Lightburned Magnesia (6~ m2/g) 0.75 9 % Soluble Mapnesium Reaction Time, Min.
Mix~L Additive (% on Resin) 1 12 6Q
None 0.48 0.801.60 ~50 min) 2 Sodium chloride (2% B.O.R.) 0.530.97 - -3 Ammonium fluoride (0.17% 8ØR.) 0.260.53 0.69 4 Nor,e 0.43 0.76 --Sodium chloride (2% B.O.R.) 0.520.91 - -

6 Ammonium fluoride (0.17% B.O.R.) 0.200 34

7(b) None o 0015

8 Citric Acid (2% B.O.R.) .16 0.31

9 Tetraethoxy Silane (2% B.O.R.) 0.470.72

10(C) Tetraethoxy Silane (2% B.O.R.) 0.430.69

11 (d) Silbond 40 0.54 0.901.25 (a~ter 15 min.)

12 ~ Ll ,N 1 -Tetramethy~-1,3-propane-diamine (2% B.O.R.)0.64 1.05

13 Pentane-2,4-dione (2% B.O.R.)0.73 1.09 1.67 (a) Mixes 1-3, 7-13 use ~-butyrolactone Mixes 4-6 use inert solvent 2 methoxyethyl ether (b) No resin is present, but proportionate amounts of water, alcohols, D.M.F. in resin are present.
( c ) Delayed addition of ester and magnesia by five minutes.
( d ) Delayed addition of ester and magnesia by 30 minutes.

; R.I.C -2195 10/15/90 A

In this example, a number of di- and tri-amino compounds were tested as accelerators, including acyclic and cyclic compounds. The results of this example are shown in Table 6. Mix No. 8 shows the additive accelerating effect of TRIS and a chloride.

Paga 50 ~ i ~ ;? ~~ j R.l.C. 2195 10/15190 ,." ,. ,~

Fffect of Solvent & Amine on Gel Tirne of Flesin C/y-ButyrolactonelMa9nesia Mix: 8.0 9 Resin C
1.33 9 solvent 1.2 9 y-butyrolactone 1.6 9 magnesia (surface area of 65 m2/g) Amine Gel Time Mi~ Solvent (2% on resin) Min. (25'C~

2 1:1 H20/dipropylene glycol n-monobutyl ether (DPnB) 315 3 1:1 H20/DPNB TRIS ~2,4,6-tris(dimethyl- 205 aminomethyl) phenol}
4 1:1 H20/DPnB 1,1,3,3-tetramethyl-guanidine 277 1:1 H20/DPnB .~l,N,Nl,Nltetramethyl 194 ethylene diamine 6 1:1 H20/DPnB ~LN,N1,N1-tetramethyl-174 1 ,3-propanediamine 7 1:1 H20/DPnB 1,3,5-triethyl hexahydro- 213 1 ,3,5-s-triazine 8 1:1 H20/DPnB TRIS ~ 0.5% HCI, which 16 corresponds to TRIS
dihydrochloride 9 1:1 H20/DPnB 0.5% HCI 244 1:1 H20/tetramethylene-sulfone TRIS 217 11 1 :1 H20/polyethylene glycol (mol. wgt. 300) TRIS 195 12 1:1 H20/polyethylene glycol mono-methyl ether (mol. wgt. 350) TRIS 18 5 13 1:1 H20/polyethylene glycol mono-methyl ether (mol. wgt. 350) - - 2 7 5 R. l. C.-2195 10/15/90 Table 6, Continued Amine ~; ~Q~~2% on Resin~ Min. ~25 Ç~

14 1:1 H20/DPnB N.~,Nl,N1-tetramethyl diaminomethane 1 06 1:1 H20/DPn8 N,N-diethylathylanediamine 189 (1~4)~
16 1:1 H20/DPnB ~LN-dimethyl~1,3-propanadiamine 185 17 1:1 H20/DPn8 N,N-dipiperidinylmethane 164 18 1:1 H20/DPnB N-(3-aminopropyl)morpholine 159 l 9 1:1 H20/DPnB 4-amino-2,6-dimethylpyrimidine 251 1:1 H20/DPnB 2,21-bipyridina 206 ~ Prereacted amine with resin prior to addition of ester and MgO.

,, ., R.l.C.-21ss 1o/1s/so Tests were performed to show the effect on gel time of various additives with certain esters. The gel tirne tests were run in accordance with the procedure set ~orth hereinbefore en~itled UProcedure For Gel Determination.~ The test results set forth in Table 7 show accelerator or retarder activity of various additives at different temperatures and with different esters and resins.

R. l . C.-2195 10/1 5/go r,, j, Eftect ot Addltlv0s on Gel Tlme of Resole-Ester-Magnesla tlardener Additive (2% on Gel Time, ~i~L~ Resin ~ Undil~ned Resin) Iem~ ~ Minutçs A y-Butyrolactone None 60 7 2 A y-Butyrolactone Sodium fluoride 60 21 3 A y-Butyrolactone Monosodium phosphate 60 13 4 A Methyl lactate None 2 5 9 2 A Methyl lactate Ammonium chlorida 25 22 6 B y-Butyrolactone None 25 48 7 B y-Butyrolactone Ammonium chloride 25 19 8 B y-Butyroiactone Ammonium fluoridç 25 267 9 B y-Butyrolactone Nonç 25 52 B y-Butyrolactone Sodium sulfate 25 12 11 A Propylenç carbonate None 25 23 1 2 A Dimethyl succinate None 25 71 13 A Dimethyl succinate Lithium chloride 25 13 (a) 6.0 9 resin, 0.5 9 water 1.5 y-butyrolactone, 0.75 9 lightburned magnesia (65 m2/g surfacç area) for Mixes 1-3, 6-8. Additional 1.8 9 water for Mixes 9-10 in relation to Mix 1. Replace y-butyrolactone by 1.75 9 methyl lactate for mixes 4-5 in relation to Mix 1. ln mixes 11-13, used the indicated ester in place of y-butyrolactone in relation to Mix 1.

R.l.C.-2195 10i15/90 ~XAMP~E 8 This example was per~ormed to determine the effect of magnesia/lime ratios and additives on gel times of a resole and ester. The results of this example are shown in Table 7. tt oan be seen that in ~esin A, up to 33% of MgO hardener can be replaced by CaO with substantially no effect on gel time (mixes 1-4) but a problem results at a 1:1 ratio (mix 5). In contrast, Resin C (lower molecular weight and higher free phenol) cannot tolerate even a 20% replacement of MgO with CaO without significantly adversely affecting gel time (Mix 10 versus control Mix 8). These results run counter to the Gupta U.S. 4,794,051 patent cited earlier herein in Col 4, lines 4~53 and 34-37, it is stated that magnesium oxide or hydroxide is too slow a hardening agent and that it is preferable to use a mixture of calcium and magnesium alkalis at a ratio of 10:1 to 0.1 to 10. Furthermore, it should be pointed out that the Gupta compositions remain thermoplastic ~at about 20'C to 70 C for 24 to 100 hours or longer~ (Col. 60, line 23 of Gupta) whereas the mixtures of phenolic resole resin and hardener or hardeners of this invention without retarder, harden in less than 24 hours.

Pags 55 R. l . C.-2195 10/15/90 Effect of Magnesia Hardener Lime Ratio and Additives On Gel Time of Resole-Ester Gel Time, Additive Mi~L~Rçsin ~Ik~ lT~mr~-C~LLQ~ ~2% on R2sin) A MgO 25 48 - -2 A 4:1 MgO/CaO 2 5 49 - -3 A 3:1 MgO/CaO 25 50 --4 A 2:1 MgO/CaO 25 52 --A 1:1 MgO/CaO 25 Mix lumps, test not run --6 A 2:1 MgO/CaO 25 11 NH4CI
A 2:1 MgO/CaO 25 104 NH4F
8 C MgO 60 54 --g(b) C 2:1 MgO/CaO 60 t 23 - -1 o(b) C 4:1 MgO/CaO 60 94 - -11 C MgO 60 6 2 Melamine 12 C MgO 60 79 Aspartic acid 13 C MgO 60 28 --14 C MgO 60 42 NH4F (0.1~% on resin)

15(c) C ~lgO 60 47 - -

16(c) C t,lbO 60 63 NH4F (0.15% on resin)

17(c) C MgO 60 115 Tetraethoxysilane

18(c) C MgO 60 86 Tetraethoxysilane (1.0% on resin) (a) For 6 9 Resin A use 0.5 9 water, 1.5 9 y-butyrolactone, 0.75 9 alkali (lightburned MgO with surface araa of 65 m2/g). For 8 9 Resin C use 1.2 9 y-butyrolactone in Mixes 13-1d" no ester in mixas 8-12 and 15-18, and 1.6 9 alkali, namely tha MgO, CaO or mixtures thereof in all mixes with Resin C.
(b) Mild 2xo~hemm upon addition sf alkali, coalescing of panicles observed.
(c) Resin stored at about 40-F for several months.

R l.C.-2195 10/15/9o This example was per~ormed to show the effect of additives on gel times of Resin E which is a highly a!kaline phenoiic resole resin having a pH of about 13. The r~ompositions of this example did not contain a magnesium hardening agent. The results of this exarnple are shown in Table 9. Normally, with Resin E, the ethyl lactate induces hardening of the resin as shown by the gelation of Mix 1. However, all of the additives, including the chloride, which is an accelerator with the magnesium hardeners, acted as retarders or had no effect. It can be seen from Table 9 that, with this resin, most of the additives were retarders, particularly the bifluoride. The fact that ammonium chloride shows good retardation in this mixture is in marked contrast with the magnesium hardening agent systems of this invention.

R.l.C.-2195 10/15/90 '''' ? ~,i i ! .; J ~' TABLE '3 Effect of Additives on Gel Time OF Resin F with Ester Hardener (Resin E = Alphaset 9000 of Borden C:hemical Co.) Additive i~ 2% on Resin ~ Gel Time (25-C/Min) None E~hyl Lactate 4 6 2 Sodium chloride Ethyl Lactate 49 3 Sodium sulfate Ethyl Lactate 4 9 4 ~bne Triacetin 11 Ammonium chloride Triacetin 13 6 Ammonium bifluorideTriace~in 13 7 Ammonium sulfamateTriacetin 13 8 Sodiurn phosphate monobasic Triacetin 16 9 Sodium fluoride Triacetin 13 Sodium sulfite Triacetin 15 l 1 Formic acid (1.5% B.O.R.)(a) Triacetin 13 (a) Acid equivalent to 2% sodium phosphate monobasic.

R.l C.-2195 10/15190 Exam~le l 0 This example shows a series of experiments (Exp.) wherein increased tensile strength is obtained in a composition containing certain accelerators in relation to the same composition without an accelerator.
The results of this example are shown in Table 10.
The composition of Example 10 consisted of: (a) refractory magnesia aggregate made up predominantly of particles having a sieve size of 14 to 48; (b) 10% of Resin F, based on the weight of aggregate; (c) 15% of gamma-butyroiactone, based on the weight of Resin F (B.O.R.);
and (d) 30% of MAGOX 98 Premium, based on the weight of Resin F, said MAGOX 98 Premium being a lightburned magnesium oxide hardening agent having a surface area of 100 square meters per gram which is sold by Premier Refractories & Chemicals, Inc. The quantity of accelerator, when employed, was at a level of 1%, based on the weigh~ of resin (B.O.R.). The tensile strength readings provided in Table 10 for this example are that of an average of 3 specimens with the parenthetical value representing the median.
Resin F is a phenol-formaldehyde resole resin having the following properties: solids of 64.12~/o, based on the weight of resin; a water content of 5.65%, based on the weight of resin; a free phenol content of 25.19%, based on the weight of resin; a number average molecular weight (Mn) of 107; a weight average molecular weight (Mw) of aoout 200; a viscosity at 25-C of M 1/4 on the Gardner~Holt scale or 325 centistokes, which is converted to about 390 centipoise. In the manufacturs of Resin F, there is charged to a reactor a molar ratio of forrnaldehyde to phenol of 0.93 which is reacted under mild heating conditions so that 25.2% by weight of the phenol remains unreacted in the resin after distillation to reduce water to about 6% and thus also raises the molar ratio of formaldehyde reacted with phenol to a ratio of greater R. I. c.-2 ~ 95 1 ol1 s/so than one, in spite of the fact that the molar ratio of formaldehyde to phenol charged to the reactor is less than one.
The resin bonded magnesia refractory tensile specimens were prepared and tested as fol!ows. Resin F and the magnesium hardening agent were intimately admixed with th refractory magnesia. The accelerator, when used, was added at this stage. Following this stage, the gamma-butyrolactone was added to the mixture and the mixture was further mixed for a period of about 3 or 4 minutes. A 150 gram sample of the mix was then charged to a dsgbone die which was then subjected to a ramming pressure of 15 tons for one minute to produce a tensile strength specimen. The specimens, 3 inches long, 1 inch thick, and 1 inch wide at the neck, were allowed to stand 24 hours (H.) at constant temperature and humidity ~R.T.) of 72-F ~/-2-F and 51% +/- 2% relative humidity prior to being subjected to breaking on a Tinius Olsen tensile test machine. Some of the dogbone specimens, after the 24 hour (H.) period at the constant temperature and humidity conditions (R.T.) were subjected to a thermal treatmenl of 110 C for 2 hours and then allowed to cool to room temperature prior to breaking.
It can be seen from Table 10 that: the addition of the sulfamate accelerator increased the rocm temperature tensile in relation to the same composition without the sulfamate additive;
and that the addition of lithium carbonate increased both the room temperature and thermal cure tensile in relation to the same composition witho~lt this additive.

R.l.C.-21ss 10/15/9o , ., . .s ~, ..

Table 10 Effect Of Certain Accelerators t:)n Tensile Str~n~th of Aggre~ate BoundWith Low Molecular Weight Phenolic Resols Resin with Magnesium Oxide Hardener and Ester Hardener Tensile Stren~th~ psi Exa- ~ditiV~ 24 H. at ~ T. 24 H. at R.T. -~ 2H. at 110'C
None ~5 (55) 857 (890) 2 Sodium Sulfamale 18 3 ( 17 5 ) 9 5 2 ( 9 8 5 ) (1 % B.O.R.) 3 Lithium Carbonate 135 (140) 1035 (1060) (1 % B.O.R.) 4 Ammonium Sulfamale 1 32 ( 1 40) 71 7 (770) (1 % B.O.R.) R. l.C.-2195 l o/1 5/go Fxample 11 In this example, compressive strength tests were made at different times on a polymer concrete composition in r~mparison with the same composition which also contained 2%, based on the weight of Resin A (B.O.R.), of the accelerator N,N,N1,N1-tetramethyl-1,3-propanediamine and additionally, in some instances 0.1%, based on the weight of resin (B.O.R.) of SAG 10, a defoamer which also acts as an air detraining agent. SAG 10 is a 10% emulsion of dimethylpolysiloxane which is sold by Union Carbide Corporation.
The compressive strength tests of this Example 11 as well as the basic composition or standard mix is that set forth previously herein in the procedure entitled ~Procedure For The Preparation And Testing of Polymer Concrete For Compressive Strength.~ The results of this example are set forth in Table 11.
It can ~e seen from Table 11 that the compressive strength of the standard mix or control at room temperatures (R.T.) was less than that of the slandard mix after the inclusion of the accelerator at 2%, based on the weight of resin (E3ØR.), which in turn was less than that of the standard mix plus accelerator at 2% (B.O.R.) and 0.1% (B.O.R.) of the air detraining agent.
Table 11 also shows that the compressive strength of the standard mix when the accelerator and the air detraining agent were included in the composition was greater than that of the standard mix plus the accelerator under the one day of hardening age room temperature plus 2 hours thermal cure at 10D'C.

Pag~ 6?

R. l. C. -2195 10/15/90 Table 11 Compressive Stren~th of Polymer Concre~e with Accelerator And Air Detraining Agent Compressive Strenglh, psi Standard Mix ~
Standard MixStandard Mix Accelerator + Air Cure Conditions(Control)+ Accelerator Detraining Agent 8 Hours at Room Temp. 379 511 664 (Average) (382) (513) (667) One Day at Room Temp. 1246 1551 1729 (Average) (1265) (1559) (1794) One Day at Room Temp. ~ 607 7153 + Two Hours at 100'C 5777 6664 (Average) (5559) (6976) R.I.C.-2195 l O/1 5/90-A

Example 12 This example shows gel times of Resin A in accordance with the procedure and composition, also referred to as standard or control composition, set forth hereinbefore entitled ~Procedure For Gel Determination."
The results of this example are set forth in Table 12. Experiment (Exp.) 1 in Table 12 is the standard composition set forth in the above-mentioned procedure and consists of: 69 of Resin A; 0.59 of water; 1.59 of gamma-butyrolactone; and 0.759 of lightburned magnesium oxide hardener having a surface area of 65 square meters per gram (MgO 5û).
Exp. 2 in Table 12 shows the decrease in the time required for gelation of the standard composition by addition of 2% B.O.R. of the hardening accelerator N,N,N1,N1-tetramethyl-1,3-propanediamine.
Exp. 3 in Table 12 shows the prolongation of the time requird to gel the composition of Exp. 2 when the ester hardening agent, namely gamma-butyrolactone, is replaced with an inert solvent.
Exp. 4 in Table 12 shows that the addition of a relatively low surface area lightburned magnesium oxide hardener, namely Magchem 20M, had little effect on further shortening the time required for gel formation of the composition in E.xp. 2 which contains both the gamma-butyrolactone and the lightburned magnesium oxide hardener having a surface area of 65 square meters per gram. Magchem 2~M has a surface area of ten sqLare meters per gram.
Exp. 5 in Table 12 shows that the addition of the relatively low surface area (10 square meters per gram) lightburned magnesium oxide hardening agent (Mag.,hem 20M) had a relatively smail effect on decreasing the time it takes to gel the composition of Exp. 3.

'J I~ ;~J ~' R.I.C.-2195 10/15/90 A

Table 12 Effect On Gel Times Of Resole Resin A By Garnma-Butyrolactone Hardener,Various Lightburned Magnesium Oxide Hardening Agents And N,~LN1,N1-Teframethyl-1,3-Propanediamin~ Accelerator at 25 C:

Composition Time ~Minutes) Exp. 1 Control (Resin A/H20/y-Butyrolactone/MgO 50) (No accelerator) 64 Exp. 2 Control + 2% N,~ L1,N1-tetramethyl-1,3-propanediamine 48 (B.O.R.) Accelerator Exp. 3 The Composition of Exp. 2 but replace ~-Butyrolactone with 115 2-methoxyethyl ether (inert solvent) Exp. 4 The Composition of Exp. 2 but with addition of 4 6 0.75 grams (9) Magchem 20M for each 69 of Resin A
Exp. 5 The Composition of Exp. 3 but add 0.759 Magchem 20M 9 4 per each 69 of Resin A

R.I.C. 2195 10/15/9C

Example 13 The compositions of this example are the same as those of Example 12 except for ~he presence or absence of magnesium or ester hardening agents and together with Example 12 and Table 12 and the following Table 13 serve to show the synergism obtained by using both a magnesium hardening agent and an ester hardening agent in the presence of an accelerator.
Thus, in Exp. 2 of Table 12, it took only 48 minutes for the composition containing the accelerator and both an ester and the magnesium hardening agent to gel. Exp. 3 of Table 12, which is identical to Exp. 2 of the same table except that it does not contain the ester hardening agent, took 11~ minutes to gel. It can be seen from Table 13 that the identical composition of Exp. 2 in Table 12 but without the magnesium hardener had not gelled after 14 days. Table 13 also shows that the accelerator without the magnesium hardener or ester hardener had little, if any, effect on the viscosity increase of Resin A in relation to me use of the accelerator together with ester and magnesium hardener.

Pags 66 R. l.C.-21 95 1 0~1 5/90 Table 13 Effect Of Ester Hardener And Accelerator On Viscosity at 25'C Of Resin A
Over Period Of Time Hours at 6g Resin A 69 Resin A
at 25 C
0.59 Water 0.59 Water 0.12g ~LN,N1.N1-Tetramethyl- 0.129 N,N,N1,Nl-Tetramethyl-1,3-propanediamine 1,3-propanediamine (2% B.O.R.) 1.59 y-Butyrolactone 1.59 2-Methoxyethyl ether (inert solvent in place of y-Butyrolactone~

Gardner-Holt Centistokes Gardner-Holt Centistokes 0 I-J(I 1/4) 231 I-J (I 1/3) 233 6.5 K-L 288 J-K 263 14 Days W 1û70 L-M 310 R. I.C.-219~ 1 o/1 s/so This example was performed to show the effect of using a mixture of lightburned magnesium oxide hardeners of different surface areas. To a solution of 8.09 Resin A, 0.679 water, and ~.09 gama butyrolactone, there was added 1.09 lightburned magnesia having a surface area of 6~m2/g. The mixture was strongly agitated for 1 minute and then 5.09 of the mixture was transferred to each of two small cylindrical plastic vials (22mm wide) and capped and allowed to stand at 72'F +/- 2'F for 4 days. The hardened mass was removed from the vials and weighed. The hardened masses were designated as cylinders No. 1 and No. 2. These were then heated for 2 hours at 105'C, weighed and then heated for another 2 hours 13~-C and reweighed. A similar procedure was followed as above except that an additional 1.09 of lightburned magnesia having a surface area of 1û square meters per gram was added to the same quantity of the various ingredients used to prepare cylinders No. 1 and No. 2 for a total magnesia of 2.09 per 89 of Resin A and the samples designated as cylinders No. 3 and No. 4. The results are shown in Table 14 wherein the compressive failure was measured on a Tinius Olsen tensile tes~ machine. It can be seen from Table 14 ~hat samples with additional magnesia lose less weight and have higher crush strengths than samples with 50% less magnesia. The effect on gel time was minimal, as can be seen in Table 1, Mix 1, in that the mixture of magnesias had a gel time of 62 minutes for samples No. 3 and No. ~ as compared to 67 minutes for the samples No. 1 and No. ?. Following the same procedure as in this example, various accelerators such as ammonium sulfamate, sodium chloride, pentane 2,4-dione, and 2,21-bipyridine can be added to such compositions containing mixed surface area magnesium to obtain higher strength while shortening the time it takes to gel or harden binder, raw, batch, and other compositions of this invention.

;, ; ~ R.l.C. 2195 1Q~15rsO

Table 14 Ef~ect ot a Mlxtur~ ol Lightburned Ma~ne31um Oxide~ Havin~ Dl~ferent Surfac~
Area~ In Bindes Compositlor Wei~ht In (~rarns Pour ds To 2 Hours 2 HoursCompressive CylinderUnheatQ~iat 105 C at 135'C ~ai~

4.g9 4.79 4.65 2755 2 4.98 4.79 4.65 2855 i 3 4.98 4.85 4.77 3495 4 ~.96 4.83 4.75 3545

Claims

WHAT IS CLAIMED IS:

1. A method for accelerating the hardening of a phenolic resin binder composition which comprises mixing:
A a hardenable phenolic resole resin having a pH of about 4.5 to 9.5;
B. a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least about 10 square meters per gram, the quantity of said hardening agent being sufficient to increase the rate of hardening of said resin; and C. an accelerator in an amount sufficient to accelerate the hardening of said mixture, said accelerator selected from the group consisting of:
(1) a compound which has a solubility in water of at least 1% by weight at 25°C and provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate;
(2) a member selected from the group consisting of a 2,4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group;
(3) a 1,3,5-tri(lower alkyl)hexahydro-1,3,5-triazine wherein each of the lower alkyl groups has from 1 to 3 carbon atoms;
(4) lithium carbonate;
(5) 1,4-diazabicyclo[2.2.2.]octane;

(6) a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,21-bipyridine, and benzoylacetone; and (7) a compound of the formula:

wherein:
(a) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
(b) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, and (c) each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

2. The method of claim 1 wherein the resin has a pH of about 5 to 9 and the hardening agent is magnesium oxide.

3. The method of claim 1 wherein the resin is the condensation product of phenol and formaldehyde.

4. The method of claim 2 wherein the hardener comprises particles of at least two different surface areas with about 25% to 75% by weight thereof having a surface area of at least 50 square meters per gram and about 25% to 75% by weight thereof having a surface area of about 10 to 25 square meters per gram.

5. The method of claim 2 wherein the accelerator is a compound which provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate.

6. The method of claim 2 wherein the accelerator is pentane-2,4-dione.

7. The method of claim 2 wherein the cation which combines with the anion to form said compound is sodium.

8. The method of claim 5 wherein the anion is sulfamate.

9. The method of claim 8 wherein the resin has a weight average molecular weight of about 150 to 500 and contains from about 10% to 25% by weight of free phenol.

10. The method of claim 5 wherein the cation which combines with said anion to form said compound is a member selected from the group consisting of hydrogen, sodium, potassium, lithium, calcium, magnesium, ammonium, and alkyl substituted ammonium having from 1 to 4 carbon atoms in each alkyl group.

11. The method of claim 2 wherein the accelerator is a member selected from the group consisting of a 2,4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl) phenol, and a 2,4,6-tris(dialkylaminomethyl) phenol having from 1 to 3 carbon atoms in each alkyl group.

12. The method of claim 11 wherein the accelerator is in the form of an acid addition salt of an amine wherein said acid addition salt has a water solubility of at least 1% by weight and the anion of said acid is a member selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate.

13. The method of claim 2 wherein the accelerator is a 1,3,5-tri(lower alkyl)hexahydro-1, 3,5-triazine having from 1 to 3 carbon atoms in each alkyl group.

14. A method of claim 2 wherein the accelerator is lithium carbonate.

15. The method of claim 2 wherein the accelerator is 1,4-diazabicyclo[2.2.2.]octane.

16. The method of claim 2 wherein the accelerator is a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,2 1-bipyridine, and benzoyacetone.

17. The method of claim 2 wherein the accelerator is a compound of the formula:

wherein:

A each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino Paga 73 B. X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2. -CH2-CH=CH-CH2-, , and ; and C. each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

The method of claim 2 wherein the accelerator is an acid addition salt of an amine wherein said acid addition salt has a water solubility of at least 1% by weight at 25°C
and the anion of said acid is an anion which does not retard the hardening of a phenolic resole resin with a magnesium hardening agent, and the amine is a member selected from the group consisting of: a 2,4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group; 1,3,5-tri (lower alkyl) hexahydro-1,3,5-triazine having from 1 to 3 carbon atoms in each alkyl group;
2,2 1-bipyridine; 1,4-diazabicyclo[2,2,2]octane; and a compound of the formula:

wherein:

Pago 74 A each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
B. X is a member selected from the group consisting of (-CH2-)n, wherein n is an interger of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and C. each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

19. The method of claim 18 wherein the acid addition salt is that of sulfamic acid.

20. The method of claim 17 wherein the acid addition salt is that of nitric acid.

21 . A composition of claim 2 which is hardened at room temperature.

22. A composition of claim 2 which has been permitted to increase in viscosity and then thermally cured.

23. A method for accelerating the hardening of a phenolic resole resin composition which comprises mixing:
A a hardenable phenolic resole resin having a pH of about 5 to 9, a solids content of about 50% to 90% by weight of the resin, and a viscosity of about 100 to 4,000 cps at 25-;

B. from about 5% to 50% by weight of the resin of a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least about 10 square meters per gram;
C. from about 5% to 40% by weight of the resin of an ester tunctional hardening agent; and D. from about 0.5% to 5% by weight of the resin of an accelerator selected from the group consisting of:
(1) a compound which has a water solubility of at least 1% by weight at 25°C and provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate;
(2) a 2,4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group;
(3) a 1,3,5-tri(lower alkyl)hexahydro-1,3,5-triazine wherein each lower alkyl group has from 1 to 3 carbon atoms;
(4) lithium carbonate;
(5) 1,4-diazabicyclo[2.2.2.]octane;
(6) a chelating agenl selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,21-bipyridine, and benzoylacetone; and (7) a compound of the formula:

wherein:
(a) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino, (b) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and (c) each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

4. The method of claim 23 wherein the resin has a viscosity of about 200 to 3,000 cps at

25°C and the hardening agent is magnesium oxide.
5. The method of claim 23 wherein the resin is the condensation product of phenol and formaldehyde at a molar ratio of one mole of phenol for each 1.1 to 2.2 moles of formaldehyde.

26. The method of claim 23 wherein the accelerator is pentane-2,4-dione.

27. The method of claim 24 wherein the magnesium oxide hardener consists essentially of particles having at least two different surface areas with about 25% to 75% thereof, by weight, having a surface area of at least 50 square meters per gram and 25% to 75%
thereof by weight having a surface area of 10 to 25 square meters per gram.

28. The method of claim 24 wherein the accelerator compound is a 2,4, 6-tris(dialkylaminomethyl)phenol.

29. The method of claim 25 wherein the accelerator is a compound which provides sulfamate anions to the mixture.

30. The method of claim 25 wherein the accelerator is lithium carbonate.

31. The method of claim 25 wherein the cation which combines with said anion to form said accelerator compound is a member selected from the group consisting of hydrogen,sodium, potassium, lithium, calcium, magnesium, ammonium, and lower alkyl substituted ammonium having from 1 to 4 carbon atoms in each alkyl group.

32. The method of claim 24 wherein the ester functional hardening agent is a member selected from the group consisting of a lactone, a cyclic organic carbonate, a carboxylic acid ester, and mixtures thereof.

33. The method of claim 32 wherein the ester is a lactone.

34. The method of claim 33 wherein the lactone is gamma-butyrolactone.

35. The method of claim 32 wherein the ester is a carboxylic acid ester.

36. A composition prepared by hardening a mixture comprising:
A a hardenable phenolic resole resin having a pH of about 5 to 9, a solids content of about 50% to 90% by weight of the resin, and a viscosity of about 100 to 4,000 cps at 25°C;

B. from about 5% to 50% by weight of the resin of a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least about 10 square meters per gram;
C. a calcium containing compound selected from the group consisting of calcium oxide, calcium hydroxide, and calcined dolomite wherein the quantity of the calcium containing compound is less than 50% by weight of the magnesium hardener and said calcium containing compound replaces an equivalent amount, by weight of the magnesium hardening agent; and D. from about 0.5% to 5% by weight of the resin of an accelerator selected from the group consisting of:
(1) a compound which has a solubility in water of at least 1% by weight at 25°C
and provides to the mixture an anion which increases the amount of water soluble magnesium in said mixture, said anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate;
(2) a member selected from the group consisting of a 2, 4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group;
(3) a 1,3,5 tri(lower alkyl)hexahydro-1,3,5-triazine wherein each lower alkyl group has from 1 to 3 carbon atoms, (4) 1,4-diazabicyclo [2.2.2.]octane;

(5) a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,21-bipyridine, and benzoylacetone; and (6) a compound of the formula:

wherein:

(a) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
(b) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and (c) each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino.
piperidino, and pyrrolidino.

37. The composition of claim 36 wherein the hardening agent is magnexium oxide, the quantity of the calcium compound is from about 1% to 25% by weight of the magnesium hardener, and the mixture includes from about 5% to 40% by weight of the resin of an ester functional hardening agent.

38. The composition of ciaim 36 wherein the resin is the condensation product of phenol and formaldehyde.

39. The composition of claim 37 wherein the accelerator is pentane-2,4 dione.

40. The composition of claim 38 wherein the anion provided by said compound is sulfamate.

41. A composition prepared by hardening a mixture comprising:
A a hardenable phenolic resole resin having a pH of about 5 to 9, a solids content of about 50% to 90% by weight of the resin, and a viscosity of about 100 to 4,000 cps at 25°C;
B. from about 5% to 50% by weight of the resin of a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least about 10 square meters per gram;
C. from about 5% to 40% by weight of the resin, of an ester functional hardening agent; and D. from about 0.5% to 5% by weight of the resin of an accelerator selected from the group consisting of:
(1) a compound which has a water solubility of at least 1% by weight at 25°C and provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate;
(2) a member selected from the group consisting of a 2, 4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group;
(3) a 1,3,5-tri(lower alkyl)hexahydro-1,3,5-triazine wherein each lower alkyl group has from 1 to 3 carbon atoms;
(4) lithium carbonate;
(5) 1,4-diazabicyclo[2.2.2.]octane;
(6) a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,2-bipyridine, and benzoylacetone; and (7) a compound of the formula:

wherein:

(a) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
(b) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and (c) each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

42. The composition of claim 41 wherein the resin has a viscosity of 200 to 3,000 cps at 25° and the hardening agent is magnesium oxide.

43. The compsosition of claim 41 wherein the resin is the condensation product of phenol and formaldehyde at a molar ratio of about one mole of phenol for each 1.1 to 2.2 moles of formaldehyde.

44. The composition of claim 42 wherein the quantity of magnesium oxide hardening agent varies from about 10% to 40% based on the weight of resin; the ester functional hardening agent is a member selected from the group consisting of lactones, cyclic organic carbonates, carboxylic acid esters, and mixtures thereof, and the quantity of accelerator varies from about 1.0 to 5% based on the weight of resin.

45. The composition of claim 44 wherein the accelerator is a compound which provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate.

46. The composition of claim 45 wherein the cation which combines with the anion to form said compound is a member selected from the group consisting of hydrogen, sodium, potassium, lithium, calcium, magnesium, ammonium, and alkyl substituted ammoniumhaving from 1 to 4 carbon atoms in each alkyl group.

47. The composition of claim 44 wherein the accelerator is a 2, 4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol, and a 2,4, 6-tris(dialkylaminomathyl)phenol having from 1 to 3 carbon atoms in each alkyl group.

48. The composition of claim 44 wherein the accelerator is a 1,3,5-tri(lower alkyl) hexahydro-1,3,5-triazine having from 1 to 3 carbon atoms in each alkyl group.

49. The composition of claim 44 wherein the accelerator is pentane-2,4-dione.

50. The composition of claim 44 wherein the accelerator is 1,4-diazabicyclo[2.2.2.]octane.

51. The composition of claim 44 wherein the accelerator is a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,q-dione, 2,21-bipyridine, and benzoylacetone.

52. The composition of claim 44 wherein the accelerator is a compound of the formula:

wherein:
A each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
B. X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and C. each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

53. The composition of claim 44 wherein the accelerator is lithium carbonate.

54. The composition of claim 44 wherein the accelerator is an acid addition salt of an amine wherein said salt has a water solubility of at least 1% at 25°C and the anion of said acid is a member selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate, and the amine is a member selected from the group consisting of: a member selected from the group consisting of a 2, 4-di(dialkylaminomethyl)phenol, a 2,6-di(dialkylaminomethyl)phenol and a 2,4, 6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group; a 1,3,5-tri(lower alkyl)hexahydro-1,3,5-triazine having from 1 to 3 carbon atoms in each alkyl group; 2,21-bipyridine; 1,4-diazabicyclo[2.2.2.]octane; and wherein:
A each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 whan taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;

B. X is a member sslected from the group consisting of (-CH2-)n wherein n is an integer ot 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, and , and ; and C. each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

55. The composition of claim 54 wherein the acid addition salt is that of sulfamic acid.

56. The composition of claim 44 wherein the magnesium oxide hardener comprises particles of at least 2 different surface areas including about 25% to 75% by weight thereof having a surface area of at least 50 square meters per gram and 25% to 75% thereof having a surface area of about 10 to 25 square meters per gram.

57. The composition of claim 44 wherein the resin is the condensation product of phenol and formaldehyde.

58. The composition of claim 44 wherein the ester functional hardening agent is a lactone.

59. A composition of claim 44 which has been hardened at ambient temperature.

60. A composition of claim 59 which has been thermally cured.

61. A raw batch composition comprising a mixture of:
A an aggregate material;
B. a hardenable phenolic resole resin having a pH of about 5 to 9, a resin solids content of about 50% to 90% by weight of said resin, and a viscosity of about 100 to 4,000 cps at 25°C;

C. from about 5% to 40% by weight of the resin of a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least 10 square meters per gram;
D. an accelerator in an amount sufficient to accelerate the hardening of said mixture, said acceierator selected from the group consisting of:
(1) a compound which provides to the mixture an anion selected from the group consisting of cyanate, formate, hypophosphite, nitrate, phosphite, and sulfamate;
(2) a 2,4,6-tris(dialkylaminomethyl)phenol having from 1 to 3 carbon atoms in each alkyl group;
(3) a 1,3,5-tri(lower alkyl)hexahydro-1,3,5-triazine wherein each alkyl group has from 1 to 3 carbon atoms;
(4) lithium carbonate;
(5) 1 ,4-diazabicyclo[2.2.2]octane;
(6) a chelating agent selected from the group consisting of pentane-2,4-dione, heptane-2,4-dione, 2,2 1-bipyridine, and benzoylacetone; and (7) a compound of the formula:

wherein:

(a) each of R1 and R2 is a member selected from the group consisting of alkyl having 1 to 3 carbon atoms, and R1 and R2 when taken together with the nitrogen to which they are attached, represent a member selected from the group consisting of piperidino, piperazino, morpholino, thiomorpholino, and pyrrolidino;
(b) X is a member selected from the group consisting of (-CH2-)n wherein n is an integer of 1 to 6, -CH=CH-CH2, -CH2-CH=CH-CH2-, , and ; and (c) each of R3 and R4 is a member selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, and R3 and R4 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperazino, morpholino, thiomorpholino, piperidino, and pyrrolidino.

62. The composition of claim 61 wherein: the pH of the resin is from about 5 to 8.5; the quantity of resin is from about 3% to 20% by weight based on the aggregate; and the mixture includes an ester functional hardening agent in an amount sufficient to increase the rate of hardening of the mixture.

63. A composition of claim 62 which has been hardened at ambient temperature.

64. The composition of claim 62 wherein: the magnesium hardening agent is magnesium oxide having a surface area of about 10 to 200 square meters per gram; and the mixture includes fibers in an amount sufficient to improve the flexural strength of the composition on hardening.

65. The composition of claim 64 wherein: the aggregate is sand; and the composition includes from about 0.1% to 1.5% based on the weight of resin of a silane adhesion promoter and from about 0.005% to 0.1% an air detraining agent.

66. A thermally cured composition of claim 62.

67. The composition of claim 62 wherein the aggregate is a member selected from the group consisting of: refractory grade magnesia; alumina; zirconia; silica; silicon carbide;
silicon nitride; boron nitride; bauxite; quartz; corumdum; zircon sand; olivine sand;
and mixtures thereof.

68. The composition of claim 62 rein the phenolic resole resin is the condensation product of phenol and formaldehyde and the composition includes a filler.

69. The composition of claim 67 which further includes from about 5% to 25% of graphite based on the weight of the aggregate and from about 1% to 5% by weight of the aggregate of a metal powder selected from the group consisting of aluminum, magnesium, and silicon.

70. A composition of claim 69 which has been hardened at ambient temperature.

71. A composition of claim 69 which has been thermally cured.

72. A raw batch composition comprising a mixture of:
A. a hardenable phenolic resole resin having a pH of about 5 to 9, a resin solids content of about 50% to 90% by weight of said resin, and a viscosity of 100 to 4,000 cps at 25°C;
B. a magnesium hardening agent selected from the group consisting of magnesium hydroxide and lightburned magnesium oxide having a surface area of at least about 10 square meters per gram, the quantity of said hardening agent being sufficient to increase the rate of hardening of said resin;
C. from about 5% to about 40% based on the weight of resin of an ester functional hardening agent;

D. from about 0.1% to 5% based on the weight of resin of an accelerator which provides to said mixture an anion which increases the water soluble magnesium in said mixture, said anion selected from the group consisting of: bisulfite; bisulfate;
bromide; chloride; sulfate; sulfite; and thiosulfate.

73. The composition of claim 72 wherein: the resin has a viscosity of about 200 to 3,000 cps at 25°C; the magnesium hardening agent is magnesium oxide; and the composition includes a member selected from the group consisting of an aggregate and a filler.

74. The composition of claim 72 wherein the mixture includes a calcium containing compound selected from the group consisting of calcium oxide, calcium hydroxide, and calcined dolomite wherein the quantity of the calcium containing compound varies from about 1% to 25% by weight of the magnesium hardening agent and said calcium containing compound replaces an equivalent amount, by weight, of the magnesium hardening agent.

75. The composition of claim 73 wherein said anion is provided by an acid addition salt of an amine wherein the anion of said acid is a member selected from the group consisting of bisulfite, bisulfate, bromide, chloride, sulfate, sulfite, and thiosulfate.

76. The composition of claim 73 wherein the ester is a lactone.

77. The composition of claim 73 wherein the ester is a carboxylic acid ester.

78. The composition of claim 73 wherein the anion is provided by a reactive organic chlorine or bromine containing compound.

79. The composition of claim 73 wherein the anion is chloride.

80. The composition of claim 73 wherein the anion is sulfate, bisulfate, or bisulfite.

81. A composition of claim 73 which is hardened at ambient temperature.

82. A composition of claim 73 in which the viscosity has been permitted to increase at ambient temperature and is subsequently thermally cured.

83. A composition comprising a mixture of:
A. a hardenable phenolic resole resin having a pH of about 5 to 9;
B. lightburned magnesium oxide hardener in an amount sufficient to increase the hardening rate of said resin wherein the hardener comprises particles of at least two different surface areas with about 25% to 75% by weight thereof having a surface area of at least 50 square meters per gram and 25% to 75% by weight thereof having a surface area of about 10 to 25 square meters per gram.

84. The composition of claim 83 including an ester functional hardening agent in a quantity sufficient to increase the hardening rate of said mixture.

85. The composition of claim 83 wherein: the quantity of magnesium oxide is 5% to 50% by weight of the resin; the quantity of the ester is from about 5% to 40% by weight of the resin; and the magnesium hardener consists essentially of particles of at least two different surface areas with about 25% to 75% by weight thereof having a surface area of at least 50 square meters per gram and 25% to 75% by weight thereof having a surface area of from about 10 to 25 square meters per gram.

86. The composition of claim 84 wherein the phenolic resole resin is the condensation product of phenol and formaldehyde.

87. A composition of claim 83 which has been hardened at ambient temperature.

88. A composition of claim 83 in which the viscosity thereof has been permitted to increase at ambient temperature and is subsequently thermally cured.