Quaternary ammonium carbonate compositions and preparation thereof

Quaternary ammonium carbonates having the formula ##STR1## wherein R.sup.1 is a C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl group and R.sup.2 is a C.sub.8 -C.sub.20 alkyl group have been synthesized. These compounds and compositions further comprising the corresponding quaternary ammonium bicarbonate ##STR2## wherein R.sup.1 is the same or a different C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl group and R.sup.2 is the same or a different C.sub.8 -C.sub.20 alkyl group and/or the corresponding quaternary ammonium metal carbonate ##STR3## wherein R.sup.1 is the same or a different C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl group; R.sup.2 is the same or a different C.sub.8 -C.sub.20 alkyl group and M is a non-coupler metal, are prepared by reacting two reactants, a C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium chloride and a metal hydroxide, in a solvent comprising a C.sub.1 -C.sub.4 normal alcohol. The amount of metal chloride reactant is that amount sufficient to yield the C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium hydroxide, a metal chloride, and optionally unreacted metal hydroxide. The resultant quaternary ammonium hydroxide and any unreacted metal hydroxide are then reacted with carbon dioxide to yield the quaternary ammonium carbonate and optionally metal carbonate. Also provided is a method for preserving a wood substrate. Accordingly, the substrate is treated with a metal coupler-free wood preservative system comprising a biocidal effective amount of the carbonate quats above, preferably those prepared by the method above, and a solvent.

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Table of Related Applications 
Appln. No. 
Dated Filed 
Title Inventor 
______________________________________ 
08/074,313 
Concurrently 
Quaternary Ammonium 
Leigh E. 
herewith Hydroxide Walker 
Compositions and 
Preparation Thereof 
08/074,136 
Concurrently 
Quaternary Ammonium 
Leigh E. 
herewith Carboxylate Walker 
Compositions and 
Preparation Thereof 
08/074,314 
Concurrently 
Waterproofing and 
Leigh E. 
herewith Preparation Walker 
Compositions and 
Preparation Thereof 
______________________________________ 
1. Field of the Invention 
This invention relates to the indirect synthesis of C.sub.1 -C.sub.20 alkyl 
or aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium 
carbonate compositions from corresponding quaternary ammonium chlorides. 
Di C.sub.8 -C.sub.12 alkyl quaternary carbonate compositions, including 
those prepared by the method of the present invention, are particularly 
useful in wood preservative systems, as surfactants and as biocides. 
2. Background of the Invention 
Quaternary ammonium compounds (quats), and particularly 
didecyldimethylammonium chloride (DDAC) 
##STR4## 
could be used as wood preservatives, if they were stable, because they 
possess resistance properties to fungi and termites, to loss of strength, 
and to electrical sensitivity similar to those of commonly used acidic 
copper/chromium/arsenic solution (CCA) or ammoniacal copper and arsenic 
salt solution preservatives. See Proc of the Am. Wood Pres. Assoc., 
80:191-210 (1984). Although chloride quats do not include potentially 
dangerous heavy metals, didecyldimethylammonium chloride leaches rapidly 
in soil (Nicholas et al., Forest Prod. J., 41:41 (1991), and therefore, 
does require coupling with copper salt. 
Findlay et al., U.S. Pat. No. 4,929,454, disclose a method of preserving 
wood by impregnation with a quaternary ammonium compound and at least one 
of zinc and copper, wherein the quat anion is chosen from the group 
consisting of hydroxide, chloride, bromide, nitrate, bisulfate, acetate, 
bicarbonate, and carbonate, formate, borate and fatty acids. These quats 
have distinct environmental and safety advantages over commonly used 
acidic copper/chromium/arsenic solution (CCA) or ammoniacal copper and 
arsenic salt solution preservatives in that potentially dangerous heavy 
metals are not included. The Findlay et al. quats require copper or zinc 
in order to render them relatively insoluble and to prevent them from 
leaching out of a treated substrate. The use of copper or zinc in the 
above formulations may yet raise environmental and corrosion concerns. 
Additionally, didecyldimethylammonium chloride tends to absorb 
preferentially to the surface of the wood and does not uniformly treat the 
whole substrate. Finally, DDAC treated wood shows surface erosion or ages 
upon exposure to light. See Preston et al., Proc. Am. Wood Pres. Assoc., 
83:331 (1987). 
The biocidal activities of various chloride quats against bacteria, fungi, 
and algae are tabulated in Cationic Surfactants, E. Jungerman Ed., pp. 
56-57, Marcel Dekker, Inc., 1969. Nicholas, "Interaction of Preservatives 
with Wood," Chemistry of Solid Wood, Advance in Chemistry Series #207, 
Powell ed., (A.C.S. 1984) notes that didecyldimethyl ammonium compounds 
and particularly DDAC are potential biocides. Preston, J.A.O.C.S. 60:567 
(1983) concurs and suggests that maximum fungitoxicity is exhibited with 
dialkyldimethyl compounds having C.sub.10 -C.sub.12 alkyl groups. Butcher 
et al., Chem Abstracts No. 91:152627b, suggests that the presence of an 
acid or a base can affect the activity of didecyldimethyl-ammonium quats. 
Quaternary ammonium compounds (quats) are typically prepared by the 
reaction: 
EQU R.sup.1 R.sup.2 R.sup.3 N+R.sup.4 X.fwdarw.R.sup.1 R.sup.2 R.sup.3 R.sup.4 
NX (II) 
wherein X is a halogen, a sulfate, a sulfo compound, or the like. When at 
least one of R.sup.1, R.sup.2, R.sup.3, or R.sup.4 is C.sub.12 or longer, 
the product is an inert soap. Many of the inert soaps have biocidal 
activity against bacteria, fungi, algae, and related organisms. 
Reaction (II) above is limited by the reactant R.sup.4 X because R.sup.4 
must react with tertiary amines. For example, methyl chloride (R.sup.4 
X=CH.sub.3 Cl) will react with a tertiary amine at less than 100.degree. 
C. to yield a quaternary compound R.sub.3 N.sup.+ CH.sub.3 Cl.sup.-, while 
methanol or methyl acetate (R.sup.4 X=CH.sub.3 OH or CH.sub.3 COOCH.sub.3) 
will not, under similar reaction conditions. 
General quaternary ammonium compounds with a sulfo group are easily 
prepared either by the reaction of a sulfate compound with a tertiary 
amine (III) or by a double exchange (IV). 
EQU R.sub.3 N+RSO.sub.3 CH.sub.3 .fwdarw.R.sub.3 NCH.sub.3.sup.+ 
RSO.sub.3.sup.-(III) 
EQU R.sub.3 N.sup.+ CH.sub.3 Cl.sup.- +RSO.sub.3.sup.- Na.sup.+ .fwdarw.R.sub.3 
NCH.sub.3.sup.+ RSO.sub.3.sup.- +NaCl (IV) 
If trimethylamine is heated with carbon dioxide and methanol above 
200.degree. C. and at 85 to 95 atmospheres, the carbonate quat, 
bis-tetramethylammonium carbonate, is prepared. Industrial Organic 
Nitrogen Compounds, Astle Ed. p 66, Reinhold Inc, 1961. However, this 
reaction is limited to the methyl compound because higher homologs 
decompose to olefins by the Hofman elimination reaction. See, Organic 
Reactions, 11, Chptr. 5, 377, Krieger Publishing Co., 1975. 
Chem Abst. 110, 212114 (1989) suggests that dimethyl carbonate will react 
with triethylamine in methanol in twelve hours at 115.degree. C. and under 
pressure to yield a methyl carbonate quat ester. 
Chem Abst. 114, 24824 (1991) discloses that 6-hydroxyhexyldimethylamine 
reacts with dimethyl carbonate to yield a carbonate ester quat. 
Quaternary ammonium hydroxides (hydroxy quats), the intermediate in the 
reaction scheme of the present invention, are currently prepared by the 
reaction of quaternary ammonium iodide with silver oxide (V). 
EQU RN.sup.+ (CH.sub.3).sub.3 I.sup.- +AgO.fwdarw.RN.sup.+ (CH.sub.3).sub.3 
OH.sup.- +AgI (V) 
However, this reaction is costly, and it is difficult to recover the silver 
reagent. See, Organic Reactions, 11:Chptr 5, pp. 376-377, Krieger 
Publishing Co., 1975. 
In an olefin synthesis, it has been suggested to treat a quaternary salt 
with aqueous sodium or potassium hydroxide followed by pyrolysis in order 
to form the hydroxy quat and then to decompose the hydroxy quat directly. 
However, in this method the hydroxy quat is not isolated and the 
conditions for its preparation are undesirable. See, Organic Reactions, 
11:Chptr 5, pp. 376-377, Krieger Publishing Co., 1975. 
Talmon et al., Science, 221, 1047 (1983), have used an ion exchange resin 
to convert didecyldimethylammonium bromide to didecyldimethylammonium 
hydroxide (VI). 
EQU (C.sub.12 H.sub.25).sub.2 (CH.sub.3).sub.2 N.sup.+ Br.sup.- +Ion Exchange 
Resin.fwdarw.(C.sub.12 H.sub.25).sub.2 (CH.sub.3).sub.2 N.sup.+ 
OH.sup.-(VI) 
However, 50 ml of ion exchange resin and two treatment steps were required 
to convert 3 grams of quaternary ammonium chloride to the corresponding 
hydroxide. See also, Organic Synthesis, Collective Volume VI, 552, John 
Wiley Inc., 1988; Brady et al. J. Am. Chem. Soc., 106:4280-4282, 1984; 
Brady et al. J. Phys. Chem., 90:9, 1853-1859, 1986; Miller et al. J. Phys. 
Chem, 91:1, 323-325, 1989; Radlinske et al. Colloids and Surfaces, 
46:213-230, 1990. 
Alternatively, quaternary ammonium hydroxide compositions have been 
prepared by treating a haloquat in an electrochemical cell with special 
cation exchange diaphragms between the cells. The hydroxy quat collects at 
one electrode, and the halide collects at the other. See, Japanese Patent 
Publication No. 02-106,915; Awata et al., Chemistry, Letters, 371 (1985). 
Japanese Patent Publication No. 01-172,363 discloses the preparation of 
relatively low yields of tetraethylammonium hydroxide by reacting 
triethylamine with diethyl sulfate, heating the resultant quat with 
sulfuric acid to yield the sulfate quat, and reacting the sulfate quat 
with barium hydroxide to yield the short chain quat, tetraethylammonium 
hydroxide, and barium sulfate. 
Di C.sub.8 -C.sub.12 alkyl quaternary ammonium hydroxides prepared by ion 
exchange were used as strong bases to digest animal tissue by Bush et al., 
French Patent Publication No. 1,518,427. 
Akzo discloses that the addition of a metallic hydroxide to a quaternary 
ammonium chloride such as didecyldimethylammonium chloride, in an aqueous 
medium, results in an equilibrium mixture of quaternary ammonium chloride 
and quaternary ammonium hydroxide (VII). This reaction can be driven to 
the right by the use of isopropanol as a solvent. 
EQU (R.sup.4 N)Cl+KOH.fwdarw.(R.sub.4 N)OH+KCl (VII) 
It has now been discovered that useful C.sub.1 -C.sub.20 alkyl or 
aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium 
carbonates can be prepared, particularly by indirect synthesis from 
C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl 
quaternary ammonium chlorides, through C.sub.1 -C.sub.20 alkyl or 
aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium 
hydroxide intermediates. It has further been discovered that di C.sub.8 
-C.sub.12 alkyl quaternary ammonium carbonate quats are useful in wood 
preservative systems as they have improved leaching resistance, 
particularly without the use of the commonly used metal stabilizers or 
couplers, arsenic, chromium, copper, and zinc or combinations thereof.

SUMMARY OF THE INVENTION 
Quaternary ammonium carbonates having the formula 
##STR5## 
wherein R.sup.1 is a C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl 
group and R.sup.2 is a C.sub.8 -C.sub.20 alkyl group, and preferably 
wherein R.sup.1 is the same as R.sup.2 and R.sup.1 is a C.sub.8 -C.sub.12 
alkyl group, as well as compositions further comprising the corresponding 
quaternary ammonium bicarbonate 
##STR6## 
wherein R.sup.1 is the same or a different C.sub.1 -C.sub.20 alkyl or 
aryl-substituted alkyl group as above and R.sup.2 is the same or a 
different C.sub.8 -C.sub.20 alkyl group as above, but preferably wherein 
R.sub.1 is the same as R.sup.2 and R.sup.1 is a C.sub.8 -C.sub.12 alkyl 
group; and/or the corresponding quaternary ammonium metal carbonate 
##STR7## 
wherein R.sup.1 is the same or a different C.sub.1 -C.sub.20 alkyl or 
aryl-substituted alkyl group and R.sup.2 is a C.sub.8 -C.sub.20 alkyl 
group; but preferably wherein R.sup.1 is the same as R.sup.2 and R.sup.1 
is a C.sub.8 -C.sub.12 alkyl group and M is a mono-, bi-, or trivalent 
metal,preferably a monovalent metal, and most preferably an alkali metal, 
are prepared by reacting two reactants, (a) C.sub.1 -C.sub.20 alkyl or 
aryl-substituted alkyl, C.sub.8 -C.sub.20 alkyl quaternary ammonium 
chloride and preferably a di C.sub.8 -C.sub.12 alkyl quaternary ammonium 
chloride and (b) a metal hydroxide, in a solvent comprising a C.sub.1 
-C.sub.4 normal alcohol. The amount of metal hydroxide reactant is that 
amount sufficient to yield the corresponding C.sub.1 -C.sub.20 alkyl or 
aryl-substituted, C.sub.8 -C.sub.20 alkyl quaternary ammonium hydroxide, 
and preferably the corresponding di C.sub.8 -C.sub.12 alkyl quaternary 
ammonium hydroxide, a metal chloride, and optionally unreacted metal 
hydroxide. The resultant quaternary ammonium hydroxide and any unreacted 
metal hydroxide are then reacted with carbon dioxide to yield the 
corresponding quaternary ammonium carbonate, optionally the corresponding 
quaternary ammonium bicarbonate, and optionally the corresponding 
quaternary ammonium metal carbonate, or a combination of any of the 
foregoing, and optionally metal carbonate. 
Also contemplated by the invention is a method for preserving a wood 
substrate. Accordingly, the substrate is treated with a metal coupler-free 
wood preservative system which comprises (a) a biocidal effective amount 
of at least one of the above di C.sub.8 -C.sub.12 alkyl quaternary 
ammonium carbonate compounds or compositions, and preferably those 
prepared by the method above, and (b) a solvent. 
DETAILED DESCRIPTION OF THE INVENTION 
Quaternary ammonium carbonate (carbonate quats) having the formula 
##STR8## 
wherein R.sup.1 and R.sup.2 are the same C.sub.8 -C.sub.12 alkyl group, 
have been identified for use as wood preservatives. These carbonate quats 
do not require metal couplers to render them leach resistant. 
A preferred carbonate quat is didecyldimethylammonium carbonate wherein 
R.sup.1 and R.sup.2 are a C.sub.10 alkyl group and most preferably an 
n--C.sub.10 alkyl group. Didecyldimethylammonium carbonate, when observed 
as a 70-80 percent by weight solution in a 5-7 percent by weight 
alcohol/15-20 percent by weight water is a yellow/orange liquid that has a 
slightly fruity odor. This formulation has a flash point of about 
160.degree. F., and it reacts with carboxyl containing compounds. 
The stability, and particularly the thermal stability, of carbonate quats 
is far superior to that of hydroxy quats, making these carbonate quats 
suitable for concentrating and as stock intermediates for further 
processing. 
One or more of these carbonate quats alone or in combination with the 
corresponding bicarbonate quat(s) and/or metal carbonate salt(s), 
preferably potassium carbonate salt, can be formulated as metal 
coupler-free wood preservative systems. These systems include biocidal 
effective amounts of at least one carbonate quat and a suitable solvent, 
including aqueous and non-aqueous solvents. Preferably, the solvent is an 
aqueous solvent including, but not limited to, water, aqueous alcohol such 
as aqueous ethanol, ammonia water, and the like, or a combination of any 
of the foregoing. 
Although other conventional additives may be added as required for 
application to different substrates and for different uses as known to 
those of ordinary skill in the art, metal stabilizers are not required 
and, in fact, are not recommended to inhibit leaching of the quat from the 
substrate. Accordingly, wood substrates, such as lumber, timber, and the 
like, can be treated with metal coupler-free preservative systems which 
comprise the above carbonate quat(s) diluted in a suitable solvent as 
above. 
The amount of di C.sub.8 -C.sub.12 alkyl quaternary ammonium carbonate(s) 
used to treat the substrate is a biocidal effective amount, i.e. that 
amount effective to inhibit the growth of or to kill one or more organism 
that causes wood rot, to inhibit sap stain, or a combination thereof. Such 
organisms include, but are not limited to, Trametes viride or Trametes 
versicolor, which cause a white rot; Goeophyllium trabeum, which causes a 
brown rot; and Aspergillus niger, which causes sap stain/mold. 
Typically, a wood preservative system will comprise from about 0.1 to about 
5 parts by weight of the carbonate quat(s) and from about 95 to about 99.9 
parts by weight of solvent based upon 100 parts by weight of quat and 
solvent combined. Most preferably, the wood preservative system of the 
present invention will comprise from about 1 to about 2 parts by weight of 
carbonate quat(s) and from about 98 to about 99 parts by weight of solvent 
on the same basis. 
Treatment of the substrate is accomplished by any means known to those of 
ordinary skill in the art including, but not limited to, dipping, soaking, 
brushing, pressure treating, or the like. The length of treatment required 
will vary according to treatment conditions, the selection of which are 
known to those skilled in the art. 
The metal coupler-free preservative systems of the present invention 
display greater resistance to leaching than wood preservatives currently 
used in the industry. Resistance to leaching is defined as retention of a 
biocidal effective amount, and preferably at least about 2% by weight, of 
carbonate quat(s) in the substrate over a prolonged period of at least 
about 100 hours and preferably about 350 hours. Applicants hypothesize, 
without being bound by any theory, that the carbonate quat reacts or 
complexes with the woody matrix of the substrate, thereby "fixing" it in 
the substrate. It is also believed that the long chain carbonate quat(s) 
and the wood preservative systems that include such quats enhance 
water-proofing properties of treated substrates. 
Although certain carbonate quats can be prepared by a variety of methods, 
applicants have discovered an indirect synthesis method that can be used 
to prepare a variety of C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, 
C.sub.8 -C.sub.20 alkyl quaternary ammonium carbonate compounds, 
preferably di C.sub.8 -C.sub.12 alkyl quaternary ammonium carbonate 
compounds, and most preferably didecyldimethylammonium carbonate. 
##STR9## 
wherein R.sup.1 is a C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl 
group; is a C.sub.8 -C.sub.20 alkyl group; and preferably R.sup.1 is the 
same as R.sup.2 and R.sup.1 is a C.sub.8 -C.sub.12 alkyl group; R.sup.3 is 
a straight chain C.sub.1 -C.sub.4 alkyl group; M is a mono-, bi-, 
tri-valent metal, preferably a monovalent metal, and most preferably an 
alkali metal; and m is 1 if M is mono-valent, 2 if M is di-valent, and 3 
if M is trivalent. 
A C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, C.sub.8 -C.sub.20 
alkyl, and preferably a di C.sub.8 -C.sub.12 alkyl, quaternary ammonium 
chloride is used as a starting material and is reacted with a metal 
hydroxide to yield a C.sub.1 -C.sub.20 alkyl or aryl-substituted alkyl, 
C.sub.8 -C.sub.20 alkyl, and preferably a di C.sub.8 -C.sub.12 alkyl, 
quaternary ammonium hydroxide intermediate. The hydroxy quat 
intermediate(s) and any excess metal hydroxide are then reacted with 
carbon dioxide to yield the carbonate quat(s) and the metal carbonate. 
Many di C.sub.8 -C.sub.12 alkyl quaternary ammonium chlorides are suitable 
reactants to prepare the intermediate hydroxy quat, but 
didecyldimethylammonium chloride is preferred. The selections of the 
R.sup.1 and R.sup.2 substituents of the chloride quat reactant are 
determinative of the hydroxy quat intermediate, and therefore, of the 
carbonate quat product. 
Special mention is also made of processes wherein R.sup.1 is a methyl, 
C.sub.8 alkyl, C.sub.9 isoalkyl, C.sub.10 alkyl, C.sub.12 alkyl, C.sub.14 
alkyl, C.sub.16 alkyl, or benzyl group; and R.sup.2 is a C.sub.10 alkyl, 
C.sub.12 alkyl, C.sub.14 alkyl, or C.sub.16 alkyl group. 
The metal hydroxide reactant is a mono-, bi-, or trivalent metal hydroxide, 
preferably a mono-valent metal hydroxide, and most preferably an alkali 
metal hydroxide such as sodium hydroxide or potassium hydroxide. Special 
mention made of potassium hydroxide. The metal chloride first step 
reaction product will precipitate and is easily removed, i.e. by 
filtration or the like, yielding a hydroxy quat/solvent reaction product. 
The hydroxy quat can be separated therefrom by drying or the like, if 
desired. 
The first reaction (XI) is conducted in a solvent which comprises a C.sub.1 
-C.sub.4 normal alcohol. Preferably the solvent is ethanol, and most 
preferably, anhydrous ethanol. The reaction to form the hydroxy quat is 
typically an equilibrium reaction, but the use of a C.sub.1 -C.sub.4 
normal alcohol solvent drives the reaction sharply to the hydroxy quat. 
The amount of metal hydroxide reactant typically is a stoichiometric amount 
with respect to the di C.sub.8 -C.sub.12 alkyl quaternary ammonium 
chloride reactant. Therefore, on a theoretical basis and if the reaction 
were complete and unequilibrated, there would be no excess of metal 
hydroxide reactant upon completion of the intermediate reaction. In 
practice, yield when using a stoichiometric amount of metal hydroxide 
reactant will range from about 65% to about 95%, but will vary, dependent, 
in part, upon the particular metal hydroxide reactant. 
Yield of the hydroxy quat can be further improved over conventional methods 
by utilization of a stoichiometric excess of metal hydroxide ranging from 
about 2% to about 20% excess. If an excess of metal hydroxide is used 
yield will be increased to from about 95% to about 99%, again varying as 
above. 
The unreacted metal hydroxide is soluble in the hydroxy quat/solvent 
intermediate. 
Hydroxy quat and any unreacted metal hydroxide are then reacted with at 
least a stoichiometric equivalent of carbon dioxide to yield the 
quaternary ammonium carbonate(s), and if any unreacted metal hydroxide 
were present, the metal carbonate(s), The conversion of the metal 
hydroxide to the metal carbonate is the preferred reaction of the two 
carbonations and will proceed more rapidly. The metal carbonate will 
precipitate and can be separated easily, i.e. by filtration or the like, 
leaving the stable carbonate quat(s) or carbonate quat(s)/solvent reaction 
product. 
The carbonation step can also produce the bicarbonate quat or the metal 
carbonate quat as byproducts. The carbonate quat alone or in combination 
with the bicarbonate quat and/or the metal carbonate quat are suitable for 
use in the metal coupler-free wood preservative systems of the present 
invention. These carbonate quats or carbonate/bicarbonate/metal carbonate 
compositions, do not require a metal coupler for stabilization in a wood 
substrate. Completely metal-free wood preservative systems are preferred. 
However, if a metal carbonate quat is included in the system, preferably 
the metal is not a metal currently used as a coupler, and most preferably, 
it is an alkali metal and does not pose environmental or corrosion hazards 
or concerns. 
Mixing, adding, and reacting of the components in the present invention can 
be accomplished by conventional means known to those of ordinary skill in 
the art. The order of addition of reactants or solvent in any individual 
step does not affect the process. Reactants and/or solvent can be added 
sequentially or simultaneously in any suitable reaction vessel. For 
example, the metal hydroxide may be dissolved in alcohol and the resultant 
mixture added to the chloride quat or the chloride quat may be dissolved 
in alcohol and the metal hydroxide added to the resultant mixture. 
Importantly, the method of the present invention is suitable for 
commercial scale production techniques and equipment, yet convenient for 
small scale work. 
Typically, the reactants and solvent of the chloride quat to hydroxy quat 
reaction (XI) will be stirred and heated to from about 20.degree. C. to 
about 70.degree. C. and held at that temperature for a period of from 
about 1 hour to about 5 hours. The reaction mixture is then cooled, first 
to room temperature and then to about 0.degree. C. where it is held for 
about 1 hour to about 2 hours. Any precipitated metal chloride is 
collected as is known in the art, i.e. such as by filtration. 
Alternatively, the first reaction reactants and solvent can be stirred at a 
slightly elevated temperature, i.e. from about 20.degree. C. to about 
40.degree. C., to yield the hydroxy quat/solvent mixture. Hydroxy quat can 
be separated as above. 
The carbon dioxide is generally bubbled for a suitable period known to 
those of ordinary skill in the art through the hydroxy quat/solvent 
supernatant after the metal chloride precipitate has been separated. 
Alternatively, the carbon dioxide can be added as solid dry ice directly 
to the hydroxy quat. Typically, this time varies from about 0.5 hour to 
about 1 hour at ambient temperature. Any precipitated metal carbonate is 
collected as is known in the art, i.e. such as by filtration. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The following examples illustrate the invention without limitation. All 
parts and percentages are given by weight unless otherwise indicated. 
Quaternary compounds are quantified by two phase titration with sodium 
laurylsulfate and an indicator. The mixture is buffered to a pH of 10. 
PREATION OF CARBONATE QUATS 
EXAMPLE 1 
180 grams (0.4 moles) of 80% didecyldimethylammonium chloride in 20% 
ethanol water (144 grams DDAC), 180 ml of absolute denatured ethanol 
(denatured with methanol/isopropanol), and 32 grams (0.49 mole) of 85% 
potassium hydroxide pellets (27 grams KOH) were mixed in a flask that was 
purged with nitrogen and equipped with a heating mantle and a magnetic 
stirrer. The mixture was stirred and heated at 60.degree.-70.degree. C. 
for three hours. The mixture was then allowed to cool to room temperature 
and finally cooled to 5.degree. C. 
Potassium chloride precipitated, and the precipitate was collected on a 
vacuum filter. The solid was washed with cold ethanol and subsequently was 
dried, yielding 31 grams (calculated yield 29.6 grams) of dry potassium 
chloride. 
The ethanolic solution of the hydroxy quat containing about 0.09 mole of 
unreacted KOH, was stirred while 50 grams of carbon dioxide (from sublimed 
carbon dioxide) were bubbled over one half hour. The resultant mixture was 
then filtered to remove 7.2 grams of potassium carbonate (6.2 grams 
calculated), and the filtrate was concentrated to yield an orange/brown 
liquid with 80-85% carbonate quat in water/ethanol and less than 0.1% 
chloride quat having a product with 98 to 99% exchanged quat purity. 
EXAMPLE 2 
180 grams (0.4 moles) of 80% didecyldimethylammonium chloride in 20% 
ethanol water (144 grams DDAC), 180 ml of absolute denatured ethanol 
(denatured with methanol/isopropanol), and 32 grams (0.49 mole) of 85% 
potassium hydroxide pellets (27 grams KOH) were mixed in a flask that was 
purged with nitrogen and equipped with a heating mantle and a magnetic 
stirrer. The mixture was heated to 50.degree. C. and stirred for one hour. 
Potassium chloride precipitated, and the precipitate was collected on a 
vacuum filter. The solid was washed with cold ethanol and subsequently was 
dried, yielding 31 grams (calculated yield 29.6 grams) of dry potassium 
chloride. 
The ethanolic solution of the hydroxy quat containing about 0.09 mole of 
unreacted KOH, was stirred while 50 grams of carbon dioxide (from sublimed 
carbon dioxide) were bubbled over one half hour. The resultant mixture was 
then filtered, and the filtrate was concentrated to yield an orange/brown 
liquid. Yield was similar to that of Example 1. 
EXAMPLE 3 
The procedure of Example 1 is followed substituting 0.4 moles of 80% 
octyldecyldimethylammonium chloride for the didecyldimethylammonium 
chloride to yield octyldecyldimethylammonium carbonate. 
EXAMPLE 4 
The procedure of Example 1 is followed substituting 0.4 moles of 80% 
isononyldecyldimethylammonium chloride for the didecyldimethylammonium 
chloride to yield isononyldecyldimethylammonium carbonate. 
EXAMPLE 5 
The procedure of Example 1 is followed substituting 0.4 moles of 80% 
benzyldodecyldimethylammonium chloride for the didecyldimethylammonium 
chloride to yield benzyldodecyldimethylammonium carbonate. 
EXAMPLE 6 
The procedure of Example 1 is followed substituting 0.4 moles of 80% of a 
mixture of benzyldodecyl-; benzyltetradecyl-; and 
benzylhexadecyldimethylammonium chloride for the didecyldimethylammonium 
chloride to yield a mixture of benzyldodecyl-; benzyltetrabutyldecyl-; and 
benzylhexadecyldimethylammonium carbonate. 
EXAMPLE 7 
The procedure of Example 1 is followed substituting 0.4 moles of 80% 
dihexadecyldimethylammonium chloride for the didecyldimethylammonium 
chloride to yield dihexadecyldimethylammonium carbonate. 
EXAMPLE 8 
The procedure of Example 1 is followed substituting 0.4 moles of 80% 
dodecyltrimethylammonium chloride for the didecyldimethylammonium chloride 
to yield dodecyltrimethylammonium carbonate. 
TREATMENT OF WOOD SUBSTRATES 
EXAMPLE 9 
End grain pine wafers were weighed and then soaked with 
didecyldimethylammonium carbonate until a weight gain of was observed. 
The treated wafers were then placed in water and weighed periodically to 
determine resistance to leaching. 
Results are illustrated in FIGS. 1A and 1B. 
COMATIVE EXAMPLE 9A 
The procedure of Example 9 was followed substituting 
didecyldimethylammonium chloride for the didecyldimethylammonium 
carbonate. 
Results are illustrated in FIGS. 1A and 1B. 
FIGS. 1A and 1B illustrate that the carbonate quat resists leaching for 
extended periods while the chloride quat leaches to levels of 1% or less 
in a relatively short period. 
EXAMPLES 10 AND 11 AND COMATIVE EXAMPLES 10A, 10B, 11A AND 11B 
A 10".times.0.5".times.0.75" piece of ponderosa pine was equilibrated, 
weighed, and heated for two hours at 60.degree. C. The wood was treated 
with a treating solution of 2% didecyldimethylammonium carbonate in water 
solvent by heating in the solution at 60.degree. C. to 80.degree. C. for 
one hour, cooling and standing overnight, and then being subjected to a 
second warm to cool cycle. The samples were allowed to dry to constant 
weight, and the uptake was determined by comparing starting and finishing 
weights. 
The samples were then heated for two hours at 60.degree. C., and the weight 
of the warm treated samples was compared to the oven dried sticks before 
treatment. 
Additional examples were prepared either omitting the carbonate quat, 
substituting a chloride quat, or using 1% quat in a 3% aqueous ammonia 
solvent. 
Formulations and results are illustrated in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Weight Uptake from Quat Solutions 
Example 
10 10A 10B 11 11A 11B 
__________________________________________________________________________ 
Solvent 
Water Water 
Water 
3% Ammonia 
3% Ammonia 
3% Ammonia 
Quat Carbonate 
-- Chloride 
Carbonate 
-- Chloride 
Weight 
1.8 -0.4 
0.6 1.6 -0.6 2.0 
Uptake (%) 
__________________________________________________________________________ 
Examples 10 and 11, when compared with Comparative Examples 10A, 10B, 11A, 
and 11B respectively, illustrate the ability of the carbonate quats of the 
present invention to be applied to wood substrates. The carbonate quat is 
absorbed better than the chloride quat in water, and is absorbed similarly 
to the art accepted chloride quat in ammonia/water. However, the carbonate 
quats can be used without metal coupling agents in treating wood 
substrates. 
EXAMPLES 12-15 AND COMATIVE EXAMPLES 12A, 12B, 15A and 15B 
A piece of wood was treated according to the procedure of Example 10. The 
piece of wood was then soaked in water at room temperature for 24 hours, 
dried to constant weight, and weighed to determine how much chemical 
remained. The piece of wood was soaked for 96 additional hours (120 hours 
total), dried to constant weight, and weighed to determine the leaching of 
quat from the treated wood. The water was changed several times during 
this period. 
Additional examples were prepared with different quat concentrations, 
different anions, and different solvents. 
Formulations and results are illustrated in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Leaching of Quat 
Example 12 12A 12B 13 14 15 15A 15B 
__________________________________________________________________________ 
Solvent Water Water 
Water 
Water Water 3% Ammonia 
3% Ammonia 
3% Ammonia 
Quat 2% 2% 2.5% 5% 2% 2% 
Carbonate Chloride 
Carbonate 
Carbonate 
Carbonate Chloride 
Weight Uptake 
1.8 0.4 0.6 1.1 1.8 1.6 0.6 2 
(%) 
Retained Quat 
2/110 -0.2/-- 
0.5/83 
--/100+ 
--/100 
1.7/100 
-0.3/-- 
1.7/85 
at 24 Hours 
(Absolute %/ 
Relative %) 
Retained Quat 
1.6/80 
-0.2/-- 
0.4/67 
--/-- --/-- 1.2/75 -0.3/-- 
1.36/65 
at 120 Hours 
(Absolute %/ 
Relative %) 
__________________________________________________________________________ 
Examples 12-15 and particularly Example 12, when compared with Comparative 
Examples 12A and 12B, and Example 15, when compared with Comparative 
Examples 15A and 15B, demonstrate the improved retention properties of 
carbonate quats over conventional chloride quats, particularly in the 
absence of metal stabilizers. 
All patents, applications, articles, publications, and test methods 
mentioned above are hereby incorporated by reference. 
Many variations of the present invention will suggest themselves to those 
skilled in the art in light of the above detailed description. Such 
obvious variations are within the full intended scope of the appended 
claims.