Note: Descriptions are shown in the official language in which they were submitted.
```` ~ ~058353
This invention relates to compositions and proceduxes for
preserYing wooden poles, thereby prolonging the service life of wooden
poles partially buried in the ground by treatment either beEore or after
they are so partially buried and whether the poles are wet or dry.
Telephone'communication poles, and wooden power transmission
poles will decay in line service (particularly at the ground/air inter-
face) unless protected with wood preservatives. Generally, for a long
service life (50 years or more), the poles are pressure impregnated
with wood preservatives. These preservatives often lose effectiveness
over a period of 25 to 35 years, generally in the groundline region (i.e.
the ground/air interface) where conditions for leaching microbial acti-
vity and slow movement of preservative to the surrounding soil deplete
the preservatives to ine~ffective levels. It is much more economical to
apply a remedial form of preservative treatment to replenish the toxicity
required at the groundline region than to replace the old poles with new
impregnated ones. Poles which are given such remedial treatment with
presently available preservatives are expected to last from 5 to 15 years
longer than if they had been left untreatedO Hence, the groundline
treatment must be repeated at 5 to 15 year intervals.
~20 The need for prolonging the service life of existing poles is
most urgent. Because many users of such poles cannot meet the demand
for new pole requirements, existing poles must consequently be so
improved that they will not require early replacement. This, in turn,
means that the need for an improved form of groundline preservative is
therefore urgently required.
A number of preservative mastics, or paste-type chemical formu-
lations for groundline treatment exist. Most of these formulations con-
tain pentachlorophenol in a suitable solvent, and non-leach resistant
additives such as, for example, sodium fluoride and borax. Such formula-
tions are applied to the groundline areas of utility poles in the form of
bandages. However, since pentachlorophenol has been in short supply for
the past few years and since this shortage may continue in the future, an
- 1- ~ ,
1~58353
'. .
alternative preservative is desirable,''0n the other hand, the non-leach ;'
resistant chemicals, when used alone,'have a short life, and have been
found not to be economically favourable.'
While pentachlorophenol is very leach resistant, the rate of '~
penetration of thes~ systems is very Slow9 often requiring more than 5
years for the toxic pentachlorophenol system to penetrate 1-1/2
inch depth. It is also-believed'that the pentachlo~ophenol bandages lose -''
some of their effectiveness after 10 to-15 years following pole treatments,
and that re-treatments may be necessary at a maximum of 15 year intervals. ;~
On the other hand, while sodium fluoride penetrates rapidly, the levels
of retention are very often too lo~ to be effective. '
Pentachlorophenol', the'main component of the'above-described
~ .
groundline preservatives, is oil soluble and is carried in solvents such
as, for example, grease,'thickened oil base, etc. Consequently, the
system is not essentially compatible with wet wood, i.e. wood which is
considerably above the fibre saturation point. A very high percentage of
poles are wet at the butt ends where effective treatment is required. It
has also been found that the toxic components in many of the commercial
formulations of groundline bandage preservatives do not penetrate the
entire sapwood depth in poles. Consequently, it is believed that suit-
able groundline treatment of poles may exténd their service life by 2 to
5 years.
A soluble borate such as, for example,'sodium tetraborate in
water has been used in "pressure-diffusion" treatments in Australia.
Such process consists of impregnating round material with a high concen-
tration of the borate in an abbreviated schedule (in the retort) and then ~'
stacking the material to allow deeper penetration by diffusion. However,
this technique suffers the disadvantage that an expensive pressure system
is necessary. ~-
Other prior art compositions suffer further disadvantages.
Thus, United States Patent ~o. 2,875,020 issued February 24, 1959 to
R.G. Ring provides a wood preservative method and package including a
`~ ~058353
porous fibrous oil and water permeable sheet, e.g~ a porous fibrous
material such'as, for example,'fabrics and felted'-mats of vegetable
fibres or glass fibre; a layer'on one side only of the sheet of an
- inert, oil base carrier'of grease-like consistency containing at least
2% pentachloropheno~, and a synthetic reservoir oil and water impervious
film completely enclosing the sheet and layer, e.g. a sleeve of poly-
ethylene, polyvinyl compounds, etc. Such procedure is labour intensive ~'~
and undesirable.'
United States Patent No. 2,939,704 issued June 7, 1960 to C.E.
Wilkinson provides a composition including a suitable asphalt base, cut
back with a volatile diluent, as well as an inorganic filler consisting
essentially of fine asbestos fibres, fine mica, fine vermiculate or fine
alkali metal tetraborate. This suffers the disadvantage of lack of com-
patibility of the organic component (the asphalt), i.e. the most effec-
tive preservative constituent, with wet wood. '
United States Patent No. 3,376,144 issued April 2, 1968 to R.E.Strutz provides a wood preservative composition thickened with a combina-
tion of a microcrystalline wax, water'soluble non-ionic surfactant, and
water, combined with a mixture of an organic wood preservative liquid
and an alkaline inorganic alkali metal salt. This composition suffers
the disadvantage of a low level of retention.
United States Patent No. 3,390,951 issued July 2, 1968 to J.H.
Finger et'al provides a method of strengthening, preserving and extending
the life of wooden poles by applying a metal band ~o the pole surrounding
the zone of weakness with a fibrous resin impregnated material, and
connecting tension means to the pole above the upper band means and
below the lower band means and extending therebetween. This procedure
suffers the disadvantage of being too labour intensive and provides a
separate heterogenous addition to the pole.
United States Patent No. 3,409,388 issued November 5, 1968 to
R.F. Nelson provides a method for preserving wooden poles by applying a
. bandage which is an elongated tube of preservative impermeable water
-- 3 --
1[)58353
soluble material, to spaced areas of the pole and dissolving the protec-
tive ~ilm to permit direct contact'between the preservative and the pole.
This suffers the'disadvantage of low level of retention of of not pro-
viding optimum times of contact of the'wrapped preservative with the
wood.
Canadian Patent No. 568,393 issued January 6, l9S9 to Bror 0.
H~ger proposed to provide an agent for the preservation of wood including -
an aqueous ammoniacal so3ution of an amine-forming metal of the group
consisting of copper, zinc, nickel, cobalt, cadmium and silver, and dis-
solved carbon dioxide of a content of at least two-thirds of the metal
content. This composition is far too dilute to be used for groundline
treatment. The same patentee, in Canadian Patent No. 960,959 issued
January 14, 1975, provided a~composition consisting essentially of (1)
a metal compound selected from the group consisting of the oxides,
hydroxides, and carbonates of copper, zinc, nickel, cadmium and cobalt,
and (2) a fatty acid having fr~m 6 to 12 carbon atoms per molecule, dis-
solved in (3) an ammoniacal water solution. Both these compositions
suffer'the disadvantage that they do not have optimum high water repel-
lency, optimum low water uptake, optimum fast and high preservative
penetration, and optimum resistance to arsenic leaching.
Finally, Canadian Patent No. 978,474 issued November 25, 1975
naming Michael R. Clarke and Jaromir R. Rak as inventors, provides a
dilute aqueous composition comprising a normally water-insoluble compound '
selected from zinc arsenate, zinc arsenite, copper arsenate, copper
arsenite or mixtures thereof, a water repellent component, including a
carbonate or bicarbonate and sufficient ammonia to dissolve the normally
water-insoluble compound. This composition, while it is very useful, is
too dilute to be used to preserve wooden poles at the groundline in the
form of bandages. Also, the composition is not sufficiently
compatible with wet poles.
An object of one aspect of this invention is to provide a wood
treating composition which may be'used'for treating wet poles.
.:
.
1058353
`~ An object of another aspect of this invention
is to provide a wood treating composition having high levels
of retention.
An object of another aspect of thé present
invention is to provide a thickened pole preservative including
two components, namely, an-aqueous ammoniacal multiple
preservative and a thickener carrier system.
An object of another aspect of this invention
is to provide ammonia-base compositions including an active
preservative and havingathickener to give a paste-like
consistency.
An object of yet another aspect of this invention
is to provlde a method of preserving wooden poles, e.g., by
the use of a bandage-type application to in-service wood or
by applying to poles prior to being used, or by applying a:
composition to the wooden poles in such a manner that the
composition penetrates into the pole.
By à bro~ad aspect of this invention, a thickened r
ammonia-base wood treating composition is provided for
application as a covered layer to a wood surface, the composition
comprising: (A) a preservative component which is one of (i)
a normally water-insoluble salt selected from the group
consisting of zinc arsenate, zinc arsenite, copper arsenate,
copper arsenite and mixtures thereof; (ii) an ammonia-soluble
salt selected from the group consisting of copper borate,
zinc borate or mixtures thereof, and copper chromate, zinc
chromate or mixtures thereof; or (iii) an ammonia dispersible
organometallic compound selected from the group consisting of
copper naphthenate, zinc naphthenate or mixtures thereof,
copper-8-quinolinolate, zinc-8-quinolinolate or mixtures thereof,
or tributyltin oxide; and (iv) sufficient aqueous ammonia, in
~ 1 . 5
. .. . .. . . .. . ... . .
1058353
a concentration of 1 to 28% by weight NH3 to solubilize the
normally water-insoluble salt (i), or the ammonia-soluble
salt (ii), or to disperse the organometallic eompound tiii); ~;
and (B) a suffieient amount of a thiekener eomponent
selected from the group consisting of: (v~)(a) a saturated
fatty acid of 12 to 22 carbon atoms; (b) an unsaturated fatty
acid of 12 to 22 earbon atoms; (c) a eopper, zine, sodium,
potash, or amine salt of a saturated fatty aeid of 12 -to 22
carbon atoms; (d) a copper, zinc, sodium, potash, or amine
salt of an unsaturated fatty acid of 12 to 22 earbon atoms;
or (e) mixtures there~f; (vi)(a) asbestos screenings; (b)
natural serpentine fibrous fragments; (e) miea flakes; (d)
adipie acid plus asbestos screenings; (e) adipic acid plus
natural serpentine fibrous fragments; or (f) adipic acid
plus miea flakes; (vii) a mastie of (a) a petroleum fraction
seleeted from oils and greases with one of (b) asbestos
sereenings; (e) natural serpentine fibrous fragments; (d) miea r
~ flakes; (e) adipie aeid plus asbestos screenings; (f) adipie
aeid plus natural serpentine fibrous fragments; or (g)adipie aeid plus miea flakes; and (viii) a metallie soap
seleeted from an insoluble soap of naphthenie aeid, oetoie
aeid,.2-ethylhexoie aeid, rosin aeids or tall oil aeids, with
¦ aluminum, ealeium, eadmium, eobalt, eopper, iron, lead, manganese,
niekel, tin or zine; to provide a thickened composition having
a viscosity of at least 30 poises, and desirably to provide
one composition of 30 to 120 po~ses, and another composition
of 250 to 800 poises. (As used herein, the viscosity in
poises is as measured by a Brookfield Viseometer at 25C.).
In preferred variants of this invention the
preservative may be: (A)(i) a normally water-insoluble salt
~ -6-
:,` ;, :
.,. ~, : . . , , . . :. . .
, . .
~OS8353
selected from the group consisting of zinc arsenate, zinc
arsenite, copper arsenate, copper arsenite and mixtures thereof;
and (iv) sufficient aqueous ammonia, in a concentration o~
1 to 28% by weight-NH3 to solubilize the salt (i); or it may
be: (A)(ii) an ammonia-soluble salt selected from the group
consisting of copper borate, zinc borate or mixtures thereof,
... .
and copper chromate, zinc chromate or mixtures thereofi and
~,} (iv) sufficient aqueous ammonia, in a concentration of 1 to
~, _
28% by weight NH3 to solubilize the salt (ii); or it may be:
~3 (A)(iii) an ammonia dispersib]e organometallic compound selected
~ from the group consisting of copper naphthenate, zinc naphthenate
'~ or mixtures thereof, copper-8-qu~nolinolate, zinc-8-quinolinolate
i or mixtures *hereof, or tributyltin oxide; and (iv) sufficient
.~, ~
aqueous ammonia, in a concentration of 1 to 28~ by weight
NH3 to disperse the compound (iii).
In another variant, the composition includes
an acrylic resin as a water repellency improving agent.
~ In yet another variant, the composition includes r
.~, .
zinc thiocyanate, copper thiocyanate or mixtures thereof to
! ~ I
~20 increase toxicity. t
In one variation, the thickener comprises a
metallic soap.
In a preferred variation, the composition
includes 0.1 to 4% by weight copper arsenate, copper arsenite,
~, .
zinc arsenate or zinc arsenite or mixtures thereof (as Zn and/or
~. Cu metal) of the total aqueous solution; 0.15 to 10% by weight
,~t of the total aqueous solution or a carbonate or a bicarbonate; r
~ j
and from 15-26% ammonia.
In another variant, the ratio of active
~ 30 preservative ammoniaJwater in the preservative component (A) is
;"~ 20-40/15-25/65-35, while in yet another variant, the ratio of
~ preservative component (A)/thickener component (B) is 31-85/69-15.
. . , ,. - ,:
, : ~', , ;, , ; .
~- ~0583S3
: ``
Examples of suitable wood trea-ting compositions
within aspects of this invention include: (i) an-ammoniacal
solution of copper arsenate as the preservative and zinc
stearate as the thickener; (ii) an ammoniacal solution of
copper arsenate as the preservative and stearic acid as the
; thickener; (iii) an ammoniacal solution of copper arsenate
s
~1' .
.. ...
:,, ;' `. ' '. ,'" .' " ~''. ' ,~. ',' ' "~' " ',' "; ' ... .. . .
, ', ' ': ` ' " ' , .' :
1058353
-- as the preservative and lauric acid as the thickener; (iv)
an ammoniacal solution of copper arsenate as the preservative
: and asbestos screenings as the thickener; (v) an ammoniacal
solution of copper arsenate as the preservative and a mastic
of adipic acid and asbestos screenings as the thickener; (vi)
an ammoniacal solution of copper arsenate as the preservative
and a mastic of a petroleum grease and asbestos screenings as
the thickener; (vii) an ammoniacal solution of copper arsenate
as the preservative and a mastic of a petroleum grease and
. natural serpentine fibrous fragments as the thickener; (viii)
an ammoniacal solution of copper chromate as the preservative
and a mastic of a petroleum grease and natural serpentine
fibrous fragments as the thickener; (ix) an ammoniacal solution
of copper metaborate as the preservative and a mastic of a
petroleum grease and natural serpentine fibrous fragments as
thè thickener; (x) an ammoniacal solution of copper arsenite
as the preservative and a mastic of a petroleum grease and natural
serpentine fibrous fragments as the thickener; (xi) an ~.
ammoniacal solution of zinc arsenate as the preservative and
a mastic of a petroleum grease and natural serpentine fibrous
fragments as the thickener; (xii) an ammoniacal solution of zinc
arsenate and copper arsenate as the preservative and a mastic
of a petroleum grease and natural serpentine fibrous fragments
as the thickener; (xiii) an ammoniacal solution of copper borate
as the preservative and zinc stearate as the thickener; (xiv)
an ammonical solution of copper naphthenate as the preservative
and a mastic of a petroleum grease and natural serpentine fibrous
ragnlents as the thickener; (xv) an ammoniacal solution of copper
naphthenate as the preservative and a mastic of a petroleum grease
and asbestos fibers as the thickener; (xvi) an ammoniacal solution
of copper borate as the pr ervative and a mastic of natural
-8-
, . ~
.,. ~ ~ .
. , ::: . .: : :, . .
,,, . ~ ~
1058353
serpentine fibrous fragments and a petroleum grease as the
thickener; L
; ,,.
_
'1 .
, ' -, . .
.
r
-
.
-8a-. ~
C
_ _, ........ ........ . , ... , .... ,, . , . ..... ... . , .. ... .... , _ .. . . _, .. ..... , _ ........ . .. ... . .......
_ , . . ..
,. ;. * r
' '' " ' '` ' ' ' ~ ;' ' ~ , . ' ,'.
1058353
- ~_ (xvii) an ammoniacal solution o~` copper ammonium arsenate
as the preservative and a mastic of natural serpentine fibrous
fragments and a petroleum grease as the thickener; and (xviii) ~"
an ammoniacal solution of zinc ammonium arsenate as the
preservative and a mastic of natural serpentine fibrous fragments
and a petroleum grease as the thickener.
The wood treating composition within another
aspect of the invention contains sufficient thickener (B) to
provide a composition for dip treatmen-t and having a viscosity
of 30-120 poises.
The wood treating composition within yet another
aspect of the invention contains sufficient thickener (B) to ',
provide a composition for brush, roller or trowel treatment, and
having a viscosity greater than 120 poises.
The wood treating composition of another aspect
of this invention contains sufficient thickener (B) to provide
a composition for brush, roller or trowel treatment, and having
a viscosity of 250-800 poises.
The wood treating composition of still another r
aspect of this invention contains sufflcient thickener (B) to
provide a composition for trowelling which does not flow
spontaneously but lS thixotropic.
By another aspect of the invention, a method is
provided for preserving wooden poles by the steps of: (a)
applying a coating thereto of any of the compositions described
above to give a covered layer which is substantially uniform
and to provide a layer which is at least 1/8" thick; (b) providing
a substantially ammonia impervious enclosed atmosphere around
such coated wooden poles for a time sufficient to permit
penetration into the poles; and (c) re~oving the
a~
.. ~,...... . . . . .
1058353
~~ enclosure providing the ammonia impervious enclosed atmosphere,
thereby to permit volatile material to escape and provide a ' '
preservative treated wooden pole.
In one variant of this aspect, the ammonia
impervioùs enclosed atmosphere may be provided by a polyethylene
sheet enclosure.
By yet-another aspect of this invention, a method
is provided for prolonging the service~life of wooden poles
including the steps of applying a thickened ammonia composition
as described above to a preselected groundline area of a wooden
pole to give a covered layer which is substantially uniform and
thus to provide a layer of at least 1/8" thick; and applying
a substantially ammonia and water impervious bandage including
means for sealing such bandage around its edges to the coated r
groundline area of the wooden pole, the bandage providing
enforced contact between the wooden pole and the coàting. ;'
In one variant of this aspect, the bandage is
I
formed of polyethylene tape.
` The essence of'~his invention involved the use of 1,
an ammoniacal preservative solution as a thickened ~semi-solid) ~'
preservative composition which can be ~onveniently applied to
utility poles in situ as a coating by e.g., the trowelling, or
which can be applied by dipping poles therein, or which can
~'~ be applied by brushing thereon. The thickened ammoniacal wood
:
treating compositions of aspects of this invention achieve
rapid penetration into permeable as well as refractory species ~,
of wooden poles. The use of ammonia as a vehicle for including
rapid penetration-of'preservative chemicals in groundline'type
treatments according to a preferred aspect of this invention
~ 30 has not, heretofore, bee~'used.
;~ Moreover? the conjoint use of ammonia and a
~L '
10-
' 1058353
.; ,.~
thickener, either the single phase or the mastic type for the
treatment of wooden poles~ either in situ in the ground, or
individually, or in bundles, has not been suggested heretofore.
It is believed that a synergistic effect is achieved in that
the ammonia carries the otherwise water immiscible thickener
components into the wood bein~ treated~ ¦
As noted above 5 there are three classes of
preservatives useful in aspects of this invention. One class
comprises water-insoluble but ammonia-soluble zinc arsenate,
zinc arsenite, copper arsenate or copper arsenite or mixtures
thereof.
Another class includes water-soluble, ammonia- 1,
soluble salts, namely, copper metaborate or zinc metaborate or
mixtures thereof or copper chromate or zinc chromate or mixtures
thereof.
A third class includes water-insoluble, ammonia
dlspersible organometallics, e.g., copper naphthenate or zinc r
naphthenate or mixtures thereQf, copper 8-quinolinolate or zinc r
8 quinolinolate or mixtures thereof, or tributyltin oxide.
An especially preferred preservative is that
disclosed and
- I .
-lOa-
~.
: .. . , , . . .::, . .:: ,,,. : . ~ : , . : : : .
1058353
claimed in Canadian ~atent ~o. 978~474 issued NoYember 25~ 1975 in the
name of Michael R. ~larke'and 3aromir R. ~ak. 'Thus, the following preser-
vatives'may be'thickened to provide compositions of aspects of the
invention:
The prese~vative is based on copper and/or zinc ammonium com~
plexes containing aresenic anions ~As or As ) and other additives, all
components being soluble in one common aqueous ammoniacal solution. In
the above-noted'composition, the preservative compounds in the form of
water-insoluble salts of zinc or copper'or a mixture of these are
. 10 solubilized in admixture with certain specified water'repellent compounds
in the ammoniacal solution. ' ;.
The preservative composition comprises an aqueous solution con- ''
taining: (a) a normally water-insoluble compound selected'from the group .': .
consisting of zinc arsenate, zinc arsenite, copper arsenate,'and copper ''~
arsenite and mixtures'thereof in an amount of 0.1 to 4% by weight (as Zn '~
or Cu metal~ of the'total aqueous solution; (b) 0.15 to 10% by weight of ' '
the total aqueous solution of a water repellent component comprising one .'..
of (i) a water-insoluble organic acidic compound having a solubility of
0.2% and in concentration a~ueous ammonia, the water-insoluble organic
acidic compound being selected'from the group consisting of a substan-
tially water-insoluble saturated or unsaturated monocarboxylic acid having
f between 8 and 15 carbon atoms in the'carboxylic acid; a substantially
water-insoluble saturated or unsaturated'monocarboxylic acid having
between'8 and 15 carbon atoms in the carboxylic acid substituted with a
hydrocarbon radical; a substantially water-insoluble saturated or
unsaturated monocarboxylic acid having between 8 and 15 carbon atoms in
the carboxylic acid substituted'with a hydroxyl radical; a substantially
water-insoluble saturated or unsaturated monocarboxylic acid having
between 8 and ~5 carbon atoms in the'carboxylic acid substituted with a
halogen; maleinized'unsaturated fatty acids from animal or vegetable
sources, and having an acia value of 200 to 500; maleinized unsaturated
fatty acid esters from animal or vegetable sources and having an acid
- 11 -
-~ lOS8353
value of 200 to 500, maleinized unsaturated fatty.acids, formed by the
reaction of maleic acid with fatty polycarboxylic acids and having an
acid value between 200 and 500,' maleinized unsaturated fatty acids
. formed by the'reaction of maleic alkyds with fatty:polycarboxylic acids,
and having an acidr~alue between'200 and 500; maleinized unsaturated
fatty acid resins formed'by the'reaction of maleic acid with fatty poly-
carboxylic acids, and having an acid value between 200 and 500; malein-
ized unsaturated'fatty:acid resins formed'by the'reaction of maleic
alkyds with fatty polycarboxylic acids, and having an acid value between
200 and 500; aromatic carboxylic acids having an acid value between 200
and 500; acid esters of phosphoric acid with monohydric alcohols and
having an acid value between'200 and 500; acid esters of phosphoric acid .
with fatty alcohols and having~an acid value between 200 and 500; synth-
etic polycarboxylic acids having an acid value between 200 to 500, and ~.
mixtures thereof, in an amount of up to 200% of the'zinc or copper, or
(ii) a combination of the'selected'organic acidic compound and a carbon-
ate or bicarbonate ion selected from the'group consisting of zinc carbon-
ate,'zinc bicarbonate,'copper'carbonate and copper bicarbonate in an '~
amount of up to 150% of'the zinc or copper; and (c) ammonia, in an
amount of 1 to 28% by weight of the total aqueous solution; the ammonia
being sufficient to solubilize the normaliy water-insoluble salt of zinc
or copper and the normally water-insoluble water-repellent compound.
The constituents of the'preservative composition may range in
concentration (expressed'as percentage by weight of the total) as follows: -
l. Zinc and/or copper arsenic compound, present as the arsenate or the
ac arsenite, in an amount of 0.1-4 (as Zn or Cu metal). .
2..Water repellent compound being a water-insoluble organic acidic com-
pound having a solubility ~ 0.2,.the'compound being present in proportions
ranging between 0% and 200% of the'zinc or copper; or carbonate or bicar-
bonate ions present in proportions ranging between'0% and 150% of the zinc
or copper; or both the'water-insoluble organic acid compound and the car-
bonate or bicarbonate in an amount of 0.15-10, and '
, :::
- 12 -
~058353
3. Ammonia~ in an amount of 1-28.
Whether'copper and/or zinc is used, the organic acidic component ' .
may generally be defined'as an acidic compound which is insoluble in water
but wh~ch is capable of forming compounds with the'metal'ammonia complex -
which are saluble ~n aqueous ammoniacal solutions. The'organic acidic ;'
component has a solubility of _ 0.5%, preferably >3% in concentrated .
aqueous ammonia (28%).-Such'component may be'a substantially water- ; :
insoluble monocarboxylic acid having between 8 and 15 carbon atoms in .
the carboxylic acid and being either unsubstituted or substituted'with
hydrocarbon radicals, hydroxyl radicals or halogens.- Examples include
capric (decanoic), lauric (dodecanoic), myristic ~tetradecanoic);
unsaturated fatty acids, for example a 9'10-decylenic, ~ 9'10-dode- '
cylenic. The preferred materials are those saturated and unsaturated
higher aliphatic acids containing from nine to fifteen carbon atoms.
Other'organic acidic compounds which may be'ysed are maleinized unsatur-
ated fatty acids or esters from animal or vegetable sources such as, for
example,'sardine and o~her fish oils, lard, coconut oil, sesame oil,
.. . . .
soybean oil, tung oil, corn oil, and having an acid value of 200 - 500;
maleinized unsaturated fatty acids, oils and resins formed by the reaction
of maleic acid or maleic alkyds with the fatty polycarboxylic acids having
an acid value between 200 and 500; aromotic carboxylic acids and deri-
vatives thereof having an acid value between 200 and 500; the acid esters
of phosphoric acid with monohydric alcohols or fatty alcohols having an
acid value between 200 and 500; condensation polymers in which the acid
value is between 200 and 500; and any mixtures of the above. Other acids
which may be usediinclude synthet;c polycarboxylic acids such as, for
example, polyesters and alkyds having an acid value betweén 200 - 500.
The above-identified organic acidic compounds may be used as
the sole water repellent agent, or may be used in admixture with a car-
boante ion, or a bicarbonate ion. The carbonate ion or bicarbonate ion '' :
can be provided either'by selection of the zinc carbonate,'zinc bicar- ~'
bonate, copper carbonate or copper'bicarbonate,'or it can be fonmed by
- 13 -
. . - - - , ~ . ,
lOS83S3
reaction of a suitable zinc or copper salt, e.g~ the oxide with ammonium
carbona~e or ammonium bicartoonate ~n the ammonia solution. 'In addition,
the'carbonate or the'bicarbonate ma~ be used'as the'sole water'repellent
agent or may be used'in admixture with the'above-identified organic
acidic compounds.
The organic acidic components used are those which are charac-
terized'in that they'form compounds with copper'and/or with æinc which
are water-insoluble,'but which'are soluhle to greater'than 0.2%, prefer-
ably greater than 3%, in 28% aqueous ammonia solution.
If the'composition is one containing zinc ions, the wood mater-
; ial provided is one having high aesthetic considerations, while if the
solution is one containing copper'ions, the'wood material provided is one
having low aesthetic considera~ions. In either'case, the essential
presence of arsenic acids or arsenious acids or mixtures thereof in such
composition results in a composition which protects the wood against
biological degradation. ~en carboxylic acids and/or carbonic or bicar-
bonic acid ions are present in the'composition, the composition imparts
high water repellency and weather resistance to the'wood. When'carbonic
or bicarbonic acid ions or mixtures'thereof are present in the composi~
tion, the'composition imparts protection to the wood against glowing
combustion.
The'level'of'ammonia used'in the'preservative component com- ';
positions described above is generally in excess of that required to form
the copper'or zinc salts or coordinating complexes; the pH of the aqueous
compositions will generally be pH 9 or higher. The non-volatile solids
of the compositions may vary between'1% and 25% (in the case of zinc), or
between 1% and 15% (in the'case of copper, or mixtures of copper and
zinc~.
In one embodiment of preservative component, the compositions
comprise an aqueous solution of a zinc ammonium arsenate or arsenious ~ '
complex'with the'water'repellent additive in the form of carbonate or
carboxylic acids, as defined'above,'which is characterized by its ability
- 14 -
1058353 ~
to give rapid penetratlon into wood substance and which on drying leaves
wood with its natural appearance and colour, resistant to biological
deterioration, resistant to weathering and resistant to glowing combus-
tion. The treating solution has excellent stability under processing
conditions. ~ ~'
One example of such preservative component composition is:
zinc meta arsenite '1.5 parts by weight
zinc carbonate 4.5 parts by weight
decanoic acid 3 parts by weight
aqueous ammonia (5~ ammonia91 parts by weight
in water)
In another'embodiment of preservative component, the composition
comprises an aqueous solution of a copper ammonium arsenic or arsenious
complex'with the'water'repellent additive in the form of carbonate or
carboxylic acids, as defined above,'which is characterized in that it
renders the wood resistant to weathering and resistant to biological
deterioration, The treating solution has excellent stability under pro-
cessing conditions.
One example of such preservativç component composition is:
copper arsenate 3 parts by weight
copper carbonate ' 3 parts by weight
organic additive ' 2 parts by weight
e.g., as decanoic acid ~ '
aqueous ammonia 92 parts by weight
(5% ammonia in water)
Another preservative component composition is based on zinc or '
zinc and copper ammonium complexes containing arsenic anions (As or
AsV), with the weight ratio of zinc or zinc and copper (as oxides) to
arsenic (as oxides) being 1.5 or more,'containing carbonate or bicarbonate
ions, and preferably the weight ratio of C02/NH3/Zn/As or C02/NH3/Zn+Cu/As
being 1.7-2.3/5.9-6.7/1.9-2.9/.9, all components being soluble in one
common aqueous ammoniacal solution. In the above-noted composition, the
preservative compounds in the'form of water-insoluble salts of zinc or a
- 15 -
.: : :
1058353 -
mixture of zinc and copper are solu~ilized in admixture with certain
specified'water repellent compounds in the'ammoniacal solution.
Such p~eservative component c~mposition comprises an aqueous
solution containing ~a) a normally water-insoluble compound of zinc or
zinc and copper'wi~h arsenic acid or arsenious acid in an amount of 0.1 - i
4~ by weight'(as Zn or Zn + Cu metal) of the total aqueous solution, the
weight ratio of zinc or zinc and copper'(as oxides) to arsenic (as oxides)
being 1.5 or more;' Cb)'0.15 - 10% by'weight of the total aqueous solu-
tion of carbonate and/or bicarbonate ions in an amount of up to 150% of
the zinc or the'zinc and copper, and (c) ammonia, in an amount of 1 - 28%
by weight of the total aqueous solution; and the'ratio of CO2/NH3/Zn/As
or C02/NH3/Zn + Cu/As being 1.7-2.3/5.9-6.7/1.9-2.9~.9, the ammonia being -
sufficient to solubilize the'~ormally water-insoluble salt of zinc or
zinc and copper, and the carbonate and/or bicarbonate. ;
Tke constituents of the preservative composition may range in
concentration (expressed'as percentage by weight'of the total) as follows: '
1. Zinc or zinc and copper'arsenic compound, present as the arsenate or ~ '
the arsenite with the'weight'ratio of zinc or zinc and copper (as oxides~
to arsenic ~as oxides) being 1.5'or more,'in an amount of 0.1-4 (as Zn or
Zn + Cu metal), 2. Carbonate and/or bicarbonate ions present in propor~
tions ranging up to 150% of the zinc or zinc and copper, in an amount of
0.15 - 10; and 3. Ammonia, in an amount of 1 - 28; and the balance, to ;' ~
100%, water, and preferably with the ratio of C02/NH3/,Zn/As or '
CO2/NH3/Zn + Cu/As being 1.7-2.3/5.g-6-7/1-9-2 9/ 9
One embodiment of such preservative component compositions
comprises an aqueous solution of a zinc ammonium arsenate or arsenious
complex with the water repellent additive in the form of carbonate which
! iS characterized by its ability to give rapid penetration into wood sub-
stance and which, on drying, leaves wood with its natural appearance
and colour, resistant to biological deterioration,resistant to weathering
and resistant to flowing combustion. 'The treating solution has excellent
stability under processing conditions and has been found to have very low
- 16 -
--~ lOS8353
arsenic leachability.
One example of such-treating composition is:
arsenic oxide ~III)1.2 parts by weight
zinc oxide3.6'parts by weight
N~4HCO34.2 parts by weight
aqueous ammonia (28% NH ,
20 ml in 100 ml water~ 91 parts by weight
Another example of such treating composition is:
arsenic oxide (V)1.4 parts by weight
zinc oxide3.5 parts by weight
NH4HCO34.1 parts by weight
aqueous ammonia (28% NH ,
20 ml in 100 ml water)3 90 parts by weight
A preservative CompoRent composition comprises an aqueous solu-
tion of a copper ammonium arsenic or arsenious complex with the water
repellent additive in the form of carbonate and/or bicarbonate, which is
characterized in that it gives rapid penetration into the wood substance
and which, on drying, renaers the wood resistant to weathering and resis-
tant to biological deterloration. The'treating solution has excellent
stability under processing conditions and has been'found to have medium
arsenic leachability.
One example of such composition''is: -
arsenic oxide ' !1.4 parts by weight
copper oxide '2.4 parts by weight '~
NH4HC031.8 parts by weight
aqueous ammonia (28% NH ,
25 ml in 100 ml water~ 94.4 parts by weight
The above-descri6ed'preservative component is-used with a
thickener component to provide the wood treating compos'itions of various
aspects of this invention. One example of thickener used in formulating
compositions of aspects of this invention is fatty acids of 12 - 22 carbon
atoms. This includes the saturated fatty acids: lauric, tridecylic,
.. ,, ~ ~
myristic, pentadecylic, palmitic, margaric, stearic, nondecylic, arachidic,
.
1058353
and achenic, and the unsaturated fatty acids~ _dodecylic, palmi- ~
. .
toleicJ oleic, succinoleic~ pelrosel~nic~ vaccenic~ linoleic, linolenic,
eleostearic, licanic, parinaric, tariric, gadoleic, arachidonic, cetoleic,
and erucic. The'presence of carboxylic acid group in the thickener
appears to be desir~ble in assisting stability and proYiding ease of
mixing.
Various salts and soaps of these fatty acids may alsobe used.
More common ones'include copper, zinc, sodium, potash,'amine salts and
metallic soaps. '~
As used herein, the term "metallic soap" is intended to mean an '
insoluble soap of stearic acid, naphthenic acid, octoic acid, 2-ethyl-
hexoic acid, rosin ta resinate of the resin acids) or tall oil ~a tallate
of tall oil acids) with heavy.metals, e.g. aluminium, calcium, cadmium,
cobalt, copper, iron, lead, manganese, nickel, tin or zinc.
Another example of a thickener is a fibrous thickener. These
include asbestos, natural serpentine or mica flakes. While asbestos
fibres'are useful, since asbestos fibres have been indicated as being a '
., .
health hazard, it is desirable to replace the asbestos content with a ''~
natural serpentine compound, especially that mined in Timmins, Ontario, ~ '
Canada, and known as Hedman Cationic Fibre (HCF). The Hedman Cationic
Fibre can be described as follows: ' '
Hedman Cationic Fibre is the trade name of a natural serpentine ~ '
compound. Serpentine is the'geological name for a group of minerals
having in common the same chemical formula of hydrous magnesium silicates.
The most common varieties of serpentine are Antigorite, Lizardite and
Chrysotile. The Hedman product consists predominantly of Lizardite, the
balance (approximately 15 percent by volume or 10 weight percent) being
Chrysotile.
Lizardite is a one-layer'orthorhombic polymorph of serpentine.
In its natural state lizardite in the'Hedman ore has a platey or flaky
structure. The thin plates'are up to 5 microns in diameter, inflexible
and brittle. 'Due to vigorous shearing and other mechanical action in
-- lg -- '
' '' "' ''
1058353
the Hedman plant circuit~ many of the lizardite plates are broken up
into fragments and appear in abundance in the'finished'product as pris-
matic laths'of 0.2'to l.O'microns in length. 'The'main characteristics of
lizardite are platey'structure,'which can easily be recognized'with the
aid of electron di~fraction. 'The'plates are thin and do not generally
absorb and/or shatter'the electron beam to the'extent that non-serpentine
plates (for instance biotite)'do. 'In the'Hedman product, the'fragmented
' liæardite prismatic laths can be identified on 17,600X electro micro-
graphs. Also, lizardite is inflexible and non-fibrous. ~ ',
Chrysotile is a fibrous variety of serpentine and it is also
called'serpentine fibre. Those ~ibres'which are'longer than 5 microns
and have a length-to-diameter'ratio of at least 3:1 are called'"asbestos
fibres". .~ ' '
The main characteristics of chrysotile are fibrous, the fibres
having a tube running along the'length.' (This tubular structure belongs
excluslvely to chrysotile).
The'concentration of fibres'longer'than 5 microns in the fib-
rous portion of the Hedman product was determined, Only 0.2% of the
fibrous (chrysotile)'portion are longer'than 5 microns, (i.e. an asbestos
portion). This was 30'to 40 times less than in those short asbestos
fillers which may be'used as a fibrous thickener. Since only 10 - 15 per-
cent, with a maximum being 20%, of the Hedman product i9 chrysotile, only
0.02 tO 0.04 percent of the'total product is "asbestos fibres".
A portion of the fibrous thickener may be replaced by a dibasic ~ ;
acid, namely succinic, glutaric, adipic, pimelic, suleric, azelaic, or
sebacic acid. However, it is preferred that such replacement acid be
adipic acid,
CH2COOH
CH2
CH2CH2COOH
As ~oted'before,~ t--is believed that the'presence of carboxylic acid
groups assists in stabilizing the'composition as well as enabling greater
- 19 -
,,,
~058353
ease of mixing.
; The thickener may be used as a single phase thickener, or as a
mastic type. If used as a mastic type, it may be:' asbestos screenings
and a petroleum residue selected from oils, greases, petroleum jelly or ~'
petrolatum; natur~l serpentine and a petroleum residue selected from
'' oils, greases, petroleum jelly or petrolatum; mica flakes and a petrol- ;
eum residue selected from oils, greases, petroleum jelly or petrolatum;
i; adipic acid, asbestos screen;ngs and a petroleum residue selected from ;~
oils, greases, petroleum jelly and petrolatum; adipic acid, natural
serpentine and a petroleum residue selected from oils~ greases, petroleum
jelly and petrolatum; and adipic acid, mica flakes'and a petroleum
. . .
residue selected from oils, greases, petroleum jelly and petrolatum.
Any thick petroleum residue, be it oil, grease, petroleum jelly
or petrolatum may be used. The'thickened'ammonia-base preservatives can ~'
have a wide variation in viscosity depending on the mode which is desired
to apply it to the wood surface.' In all cases, the thickened preservative
should remain aæ an adherent layer'and not run off. For dip application,
the viscosity is preferably wlthin the range of 30 to 120 poises'(Brook-
" field Viscometer, 25C.). For mechanical deposition ~as by brush, roller,
trowel, etc.~, the'viscosity should be higher than 120 poises, preferablywithin 250 to 800 poises. Thicker'materi'als can be used'for trowel
application, e.g. the'composition may have a consistency similar to that
of a cup grease or of heavy putty. These thickened mixtures do not flow
spontaneously and are thixotropic. 'When passed through a colloid mill,
the thick grease-like mixtures do not liquefy but remain as a thick paste,
i.e. are stable at high shear but are thixotropic.
As used hereinabove,'"petrolatum" may be defined as white
mineral oil, liquid paraffin, or white paraffin oil, and being a colourless
transparent oily liquid, a mixture of liquid hydrocarbons; almost taste-
; 30 less and odorless even when warm; sp. gr. 0.828-0.880 ~25C.) (light?,
0.860-0.905 (26C.?'~eav~?; soluble in ether, chloroform, carbon disul-
fide9'benzine,'benzene,'boiling alcohol, and fixed or volatile oils;
_ 20 -
- , ..
1058353
insoluble in water, cold alcohol, glycerine, and derived by distillation
of high boiling C330-390oc-) petroléum fractions. '
It is also desira61e to improve the water'repellency of the
treated wood by'including, in the'composition, an acrylic wax or acrylic '
resin.
As used herein, the term ~acrylic resin" is intended to embrace
any thermoplastic or thermosetting polymer Qr copolymer of acrylic acid,
metha~rylic acid, esters of these acids or acryl~petrile, and polymer- ;
- ized, in most instances'from acrylonitrile and the methyl or ethyl esters
of acrylic or methacrylic acid. 'This includes'polyacrylates'and poly-
methacrylates. Acrylic resins, having repeating acrylonitrile units
[-CH2CH(CN)-] and acrylic rubbers, e.g. nitrile rubber having the repeat-
g [ CH2CH CHCH2CH2CH(C~)-] are also included. ~ '
In order'to provide added toxicity, it is desirable to add
zinc and/or copper thiocyanate to provide improved compositions of
aspects of this invention.
By another variant, a preservative may be prepared'as a semi-
solid mass consisting of normally water-insoluble arsenates and/or
arsenites which are maintained soluble in the ammoniacal medium. The ; ~'
ammonia is believed also to act as a rapid penetrating agent carrying the
preservative deeply into the'wood. 'Uet'wood cam be penetrated'remarkably
well. It is believed that the ammonia escapes in the gaseous
phase and the preservative remains in the wood and becomes essentially
permanently fixed. Preservatives deposited in the wood in this process
can have a life expectancy of more than 30 years based upon long term
outdoor exposure tests of wood treated with similar toxic salts.
The ammoniacal based'preservatives of aspects of this invention
have an enhanced capability of penetrating wet wood during the extreme
cold winter months. 'Transmission poles, bridge piles, and wharf timbers
could be treated in the'late autumn when the water table is low and the
preservative would be penetrated before the spring water levels are
elevated.
- 21 -
` ` 1058353 ~
j' The ammoniacal based preserYatiYes o~ aspects of this invention
thus have wide ut~lity, 'The'arsenic-containing ammoniacal preservatives,
as well as the arsenic-free'formulations of aspects of this invention are
particularly suitable ~i.e.''are substantially non-leachable) for the
; treatment of wood ~ith high moisture content. This condition frequently
occurs in utility poles set in low-lying areas and in bridge piles set ';~
in streams and in wharf piles. It is essential that~the'ammoniacal based
preservatives of aspects of this invention, when applied to the'groundline
areas of poles in the'form of bandages, be'bandaged'with an ammonia-
' 10 impervious wrapper to reduce'loss of volatile ammonia, and also that the '
bandage include means for sealing the bandage around its edges. Any
ammonia-impervious sheet, wrap or tape material can be used'to enclose '
the treated wood surface~.' Polyethylene film has been found to work well,
but other film or sheet'material, e.g. acetal resins, for example those
known by the'Trade Marks of Delrin and Celcon; cellulose acetate film;
polyethylene terephthalate film, for example that known'by'the Trade Mark
of Mylar; polyolefins including copolymers of ~thylene, polypropylene,
ethylene propylene terpolymer, and polytetrafluoroethylene, for example
that known by the'Trade Marks of Halon and Teflon; polyvinyl alcohol;
polyvinyl butyral resins; polyvinyl chloride; polyvinyl chloride- "
acetate,' and polyvinyl fluoride.' '
Since ammonia-based'preservatives penetrate wood more readily
than simple water-borne chemical salts (except possibly sodium fluoride)
modified preservatives of aspects of this invention have been provided
for preserving by dip treatments or by brush treatments. Deposits of ' '
1/8 to 3/16 inch (3 to 5 mm) thickness are sufficient for both dipping
and brushing.
After applying the coating, it is essential to provide an
essentially ammonia-impervious environment around the'pole or poles (from
material as described above?. Individual poles may be enclosed in a thin
. .
film bag, e.g. of the material described above,'and sealed. Alternatively,
piles'of treated'poles'may be c~vered'with a sheet of material described
~ 10S83S3
above. In any event, the'enclosed'environment must be maintained for
a time sufficient to permit penetration into the wood. A time of three ' '
to four weeks is believed to be sufficient. '~
Dip treatments are useful wherever treated'wood is required
- when pressure treat~lng plants are not accessible.
Brush treatments are useful for treatment of timbers in place
where decay hazard exists but the'timbers are sound or incipient decay
is suspect, for example,'for joists in crawl spaces, beams in wharf and
bridge supports, and possibly for treating deep checks in transmission
poles.
It has been'found that the'toxic ingredlents penetrate wood
more readily than ordinary water-60rne salts and are not leachable as are
regular water-borne salts. 'Simple equipment and minimal training of ' ;
operators is required. In general, it is more economical than pressure ' '~
treatments. . .
The treatment is optimum in green ~unseasoned) wood. The
treatment provides for a reduction of the loss of ammonia by evaporation
or fuming. The treated'material should be:close piled, wrapped to retain
- 23 -
1058353 ~ ~
ammonia, and be stored fo~ 30 days or longer. '
In the bandage wrapping procedure,'the'test poles'were sealed ~ '; by a band of wire tightened'with pliers at the'upper and lower edges.
Pole sections which were set in water'for 30 days were sealed'at the
bandage edges'with~a water'resistant adhesive tape.
In a specific variant of this invention, a composition contain-
ing zinc and/or copper'stearate-and zinc and/or copper (meta) borate in
an ammoniacal solution has been found to be particularly useful. Such
zinc and/or copper'stearate-ammoniacal zinc and/or copper borate system '
is different from any other groundline system, in that it involves the
use of zinc and/or copper stearate as a thickener vehicle and the use of
zinc and/or copper borate as a preservative. ` '
The organometallic~preservative component dispersed in a thickened
ammoniacal composition, e.g. copper and/or zinc naphthenate, copper and/or
zinc-8-quinolinoleate, and tributyltin oxide, of still other aspects of
this invention is particularly suitable for preserving large seasoning '
checks, cracks, and pile cut-offs Utility poles, especially those
treated with water-borne salts', frequently split longitudinally and
expose the heartwood which i8 then'vulnerable to decay. The organo-
metallic preservative can be applied with a grease gun using fine or '
fish tail-nozzles to fill cracks, breaks, checks and seasoning splits.
Copper naphthenate, as shown'by a 22 year old test of above-ground expos-
ure conducted by the'laboratory, is very effective for, treatments of ~ '
aerial sections of poles. This formulation is also useful for groundline
sections of poles set in dry locations and could incorporate agricultural
fungicides such as, for example, that known by the'Trade Mark of Mirex,
for combatting termites, carpenter'ants, etc. As discussed above, it is
necessary to apply a wrapper to minimize loss of ammonia when the com-
position of aspects of this invention is used as a groundline treatment.
Alternatively, a strip seal of some type should be used. 'It is possible,
as well, that a plurality or bundle of poles could be wrapped together.
The following examples'are given'to illustrate aspects of the
- 24 -
: , . . : : . . .
~OS8353
invention.
.....
- ~xamples 1 - 6 -
Thickened'copper arsenate and zinc arsenate preservatives are
provided'by first providing copper arsenate and zinc arsenate solutions
as follows:
By By
Copper Arsenate Weight Parts
Copper (as basic copper'carbonate)' 700 g 3.5
Arsenic (as H3As04 - 71%) 400 g 2.0
Ammonium bicarbonate (NH4HC03) 360 g 1.8
Water of solution 200 g 1.0
This solution is dissolved in 26 percent ammonia water to a volume of
2100 ml (10.5 parts). The yield is approximately 30 percent active
copper arsenate solids in 23 percent ammonia solution.
! - By By
Zinc Arsenate Weight Parts
Zinc (as zinc oxides) 123.5 g 2.9
Arsenic (as H3As04 - Jl%) 84.7 g 2.0
Ammonium bicarbonate ~NH4HC03) 142.6 g 3.4
This solution is dissolved in 627 g (14.8 parts) of 26 percent am~onia
water, to yield approximately 24 percent active zinc arsenate solids in
16.7 percent ammonia solution.
Two types of thickened'preservatives are provided. The first
type is represented by the following four single phase-substrate systems,
prepared by thickening either the zinc arsenate or the copper arsenate
solutions with suitable single phase substrates, e.g. stearate acid, zinc
stearate~ lauric acid, or asbestos screenings. The'examples which follow
are those prepared with copper arsenate.
% (by weight?
1. Copper arsenate solution 85
Zinc stearate 15
2. Copper arsenate solution 35
Stearic acid 65
- 25 -
t
' ' , ' , ' : ' ' ;' ~ ~ . . ' , ,
1058353
.
' %-(by weight)
.
3. Copper'arsenate solution 40
Lauric acid 60
'~ 4. Copper arsenate solution 70
Asbestos screenings 30
The second type is represented'by the'following two mastic
carrier systems, prepared'by thickening either the zinc arsenate~or the
copper'arsenate solution with a suitable mastic carrier system, e.g. ' '
Vaseline (Trade ~ark for a petroleum jelly consisting of a semi-solid
mixture of carbons, having a m.p. usually ranging between 38 and 60C;
it is colourless, or of a pale yellow colour, translucent, and a semi- '
solid unctuous mass) and asbestos screenings, or the more expensive
adipic acid and asbestos screenings. The following are two examples of
compositions prepared with copper arsenate:
% ~by weight)
5. Copper arsenate solution 48
Adipic acid 49
Asbestos screenings 3 - -
6. Copper arsenate solution 60
Vaseli~e 20
Asbestos screenings20
It was found that all these compositions were effective in
exhibiting good characteristics from the handling properties as '
required for field treatments of in-line poles, and in respect of pene-
tration. Composition No. 6 gave the best results.
It is observed that these copper and/or zinc arsenate and/or'~ ' -
arsenite solutions can be mixed in any proportions for use in the semi-
solid thickened formulations of aspects of this invention. However, for ~ '
heavy-duty treatments this preservative should consist of at least 50
30' percent copper arsenate and/or arsenite and up to 50% zinc arsenate and/or
arsenite, and for the most severe hazards the proportion of copper
arsenate and/or arsenite is increased'to 100 percent.
` ` 10583S3
; . ~ .
Example 7
An example using HCF instead of asbestos screenings was pre- -
pared as follows:
~ .
Wei~ht (~
Preservative: copper arsenate solution 34.5 ''
,;,.
Carrier: serpentine (HCF~ 34.5
' Grease lPetrofibe 220, the'Trade Mark for -31.0 ~'
industrial grade,'soft, low melting petro-
latum. Petrolatum may be described as
follows: Properties: Almost colourless to
amber-coloured, gelatinous, olly, trans-
lucent, semi-sol~d, amorphous mass whose
consistency varies'with the'temperature.'
I Soluble in chloroform, ether, benzine, car-
'~ bon disulfide,'benzene and oils; very
slightly soluble in alcohol; insoluble in
water. Sp. gr. 0.8I5-0'.'880 ag 60C; m.p.
38-60PC. Chief'constituents: Hydrocarbons
of the methane s~ries, (ClGH3 Up to C 2H66)
and of the olefin series, ~C 4H , etc~
Derivation: by fractional disl~ ation of
still residues from the steam distillation
of paraffin-base petroleum, or from steam-
reduced amber crude oils (oils from which '
the light'fractions have been removed).l
The formulation has very satisfactory physical properties.
-Examples 8 a~d 9
It is also possible to provide, within ambits of this invention,
arsenic-free formulations. The following arsenic-free preservatives were
made in ammoniacal solutions:
% (by weight)
8. Copper carbonate + sodium chromate 46
equivalent to approximately 37
percent copper chromate '
Hedman cationic fibre rHCF) 31
Petrofibe 220 23
100
9. Copper meta borate,'Cu(BO2)2 (20%) 46
HCF 31
Petrofibe 220 23
This mastic carrier system is suitable not only for ammoniacal
preservatives, but also suitable for certain organic preservatives
(copper naphthenate,:etc.)'which'remain stable in am~oniacal carrier
system.
- 27 -
1058353
Examples 10 - 14
The'following formulations were prepared'and found to be
`~ satisfactory and release the'preservative salts for the'bandage-type
treatments:
~ % (by weight~
10. Copper arsenate solution or zinc 31 '; '
arsenate, or a mixture of ~inc
arsenate and copper'arsenate '''
~20 to 40% salts, i.e. 15-20%
ammonia solutions of excess ammonia
Industrial petrolatum 34.5 -
Fibre ~asbestos, or Hedman Cationic ' 34.5
Fibre (HCF)] 100.0
11. Copper metaborate, Cu(~02)2, 20% in 46
ammonia solution
Industrial petrolatum 23
Fibre rasbestos or HCF) '- 31
10 0 ! ', .
12. Copper arsenate solution in ammonia 80
(or copper'borate solution~
Zinc stearate '''20
100
13. Copper carbonate + sodium chromate in 46
ammonia water equivalent to approxi~
mately 35% copper chromate
Industrial petrolatum 23
Fibre (asbestos or HCF) 31
100 ::
14. Copper naphthenate ~8% Cu) 25
Industrial petrolatum30 ''
Ammonia water'(26% NH3) 20
Fibre (asbestos or HCF) 25 `'
- 100
It has been found that zinc and/or copper is'an excellent
vehicle for ammoniacal zinc and/or copper borate and will hold 5 to 6
times its weight of solution. Water insoluble borates have not been used
heretofore as the prime ingredient in groundline bandage treatments
because of the'solubility problems.- The preservatives are generally used
- 28 -
~058353
,
- in water-soluble form and therefore remain leachable. Copper and/or zinc
', borate in the ammoniacal so~ution according to aspects of this invention
penetrate wood as well as the'arsenate and/or arsenite system of the
previously described aspects of this in~ention. The copper and/or zinc
borate system'of asipects of this invention have very hi'gh leach resis-
tance.
The tests were conducted'as follows:
' Sections of logs of red pine,'jack pine, and white spruce were
obtained, debarked and treated by spreading the preservative mixture with
a spatula. Moisture content (MC~ was determined on the outer'l-inch and
inner l-l/2-inch zones'by the oven-drying method.
The treated areas were tightly wrapped in polyethylene film
and the specimens were stored~indoors for 30 days. One series of speci-
mens was storèd outdoors during the winter months (5 months). One set of
' creosoted'white spruce specimens was included in the'tests.
Results
Test results are shown in Table 1. The influence of MC on
' depth of penetration is shown in the Table below.
'' , '
' 20
.. . .
.~ , . .
, ~ .
. :
- ' 30
.,
. ' ',
- 29 -
` . . ' .. , :
_~ 1058353
. .
: '
, 0 o ~ ~
a) ?~1 14
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-- 30 --
.
~ ` 1058353
- 1. Thickened ammonia base preservatives of aspects of this
invention penetrate wet wood rapidl~ to depths approximately equal to
pressure preserved wood (red pine, iack pine, and white spruce species).
l One inch or greater penetration at retentions exceeding 1 pound per
r,~ cubic foot of active salts can be obtained.
2. The preservatives of aspects of thls invention are stable
to temperature changes and can be used for treatments of timbers during
winter months where other types of preservatives may not be suitable.
3. The preservatives of aspects of this invention become fixed
in the wood and are expected to be equivalent to pressure treated wood
i in performance, i.e. to be effectlve for 30 years or more.
~ 4. The preservatives of aspects of this invention penetrate
;~ creosoted wood and should be well suited to retreatment of degraded
communication`and power line poles in service.
Tests on the fungidical effectiveness of copper meta boroate -
~in treated wood against two test fungi have béen carried out. At` a
retention of 0.39 pound per cubic foot, no decay attack (based on weight
; 1088) was noted; in the same test series untreated specimens lost 35
percent and 37 percent of their weight against these two fungi. This
retention could be easily obtained by the bandage method.
The system of aspects of this invention shows unexpected rapid
diffusion (one inch in 30 days) at unexpected high retentions (1 pcf of
salts) (based on calculated weight loss of the applied material).
The reoults of comparative tests between Pol-Nu (the Trade Mark
for a widely used pentachlorophenol-grease preservative), and the ammonia
composition of aspects of this invention are shown below in Table 2.
The CAA formulation was the model because penetration could be observed
:: .
easily.
':
; 30
~ ~ `" .' ' '
",': ,
- 31 - ~
: :
` -~`" 1058353
Table 2
;Comparison;of ~0~-~U~and CAA system
Average depth of penetratîon MC Average reten~ion for
l-inch depth
Species Pol-Nu CAA % Pol-Nu CAA Solids
:, . --- . _ _ :
W. spruce0.244 0.600 93 0.0642 0.189
,~ :
Jack pine 0.556 0.320 44.5 0.0628 D.171
W. spruce - - 13.8 - -
W. spruce - Vl-1.44 138 - 2.35 (ZAA)
V2-1.04 138 - 2.04 (CAA, ZAA)
. _ , . ------ -- . :
The preservative can be applied to poles or bridge piles during
low water periods, a protective sheath applied, to be effective enough
for submersion in water at high level or flooding conditions. T~o 30-day
immersion tests were carried out. The preservative of aspects of this
.
invention may be applied during low water period, or during winter time.
Copper borate, copper arsenate and zinc arsenate have been
tested in penetration tests. The copper arsenate preservative was used
as the model system because of availability. The arsenic-containing
formulations would be used under "restricted" category of the Pest Con-
trol Products Act (Department of Agriculture), i.e. only trained per-
sonnel in wood preservation, or authorized persons could carry out treat-
ments. The non-arsenic containing formulations could be designed
"commercial" since they are expected to comply with the defined limita-
tions.
A system of thickened ammonia-base wood preservatives was
formulated which has advantages over the standard grease-type (known by
the Trade Marks of Pol-Nu, Woodtreat AA, etc), and paste-type (known by
the Trade Marks of Osmosar, FCAP, etc.) preservatives. The grease-types
penetrate dry wood but diffuse very slowly, while the paste-types pene-
trate wet wood and remain leachable, usually at fairly low concentrations
because the process is limited by the amount of preservative brushed on
the wood.
The compositions of certain aspects of this invention may be
_ 32 -
.
--` 10583S3
:~
applied to the'posts by the'dip treatment or the'brush treatment.
Suitable compositions have been'formulated'by'thickening
concentrated'ammoniacal copper'arsenate,'or copper borate preservative
solutions by'the addition of thickening agents, compatible gels, etc. to
provide composition's having viscosities for dip treatments of 30 tO 120
poises, and for brush,'roller, trowel, etc. treatments of higher than
120 poises,-e.g.' from 250 - 800 poises. Other'thicker, thixotropic con-
; sistencles are als'G operative.''
Example 15
.. .. ... .. . . ..
Preservative for dip treatments: % (by'weight)
Preservative solution (copper borate;' 51.3
copper'ammonium arsenate; or zinc
ammonium arsenate)'
HCF (inert)~ ' 33-3
Industrial Vaseline (Petrofibe) lS.4
100.0
E~ample'16
Preservative for brush treatments:
Preservative solut~on (copper borate; 43.
copper ammonium arsenate; or zinc
ammonium arsenate)
HCF tinert) 28.2
Industrial Vaseline rPetrofibe~ 13.0
Petroleum Oil (S.A.E. 20) 15.4
100. 0
Such modification of the'mastic type preservative was tested
for brush application and appeared'to be satisfactory.
The effectiveness of these treatments usi~ng inorganic salts
(which remain leachable)'has been demonstrated in tests under Canadian
conditions. For example, jack pine rail ties had an average life in
track to 18 years compared to 6 to 8 years untreated. Fence posts treated
by brushing (jack pine and white spruce)'lasted for 20 years compared to
3 to 6 years untreated. ' ~ '
The'thickened'-ammonia-base preservative has been found to have
the'following main advantages.-
'~'
-- 33 -- .:
- , : ,: . . . .
--'` 105~353 ::
' 1. It may penetrate ~et'~ood rapidly; usually l-inch depth ' -
can be obtained'in a month.''Generally poles are wet'at the'groundline
and many grease-type preservatives'also-înclude water'solubles'sodium
.~ - . . . . .
~ fluoridejor borax, because the grease alone is not compatible to wet wood. -
R . 2. The'preservative of aspects of this invention in the treated
sections of wood is at high concentrations, equivalent to, or exceeding, '- ~'
requirements b~'pressure treatment. 'This, in itself~ is remàrkable for
, diffusion treatment. '
`,i 3.'The'preservative saits of aspects of this invention become
i 10 fixed in the wood and are expected'to provide adequate fungal protection
for 30 years or longer. 'This'is also remarkable for diffusion treatments.
For example,'Pol-Nu is expected'to be effective ~or 12 to 15 years~ while
Osmosar and RCAP for a maximum of 8 to lO years.
4. The'preservative of aspects of this invention will penetrate
wood durinjg winter exposure and could therefoFe be'used'in locations
where grease-type or pasté-type preservatives'may be ruled out. For
example, bridge pilings set in streams, ponds, or running water, could
be treated in the'fall at iow water'level, or possibly shortly after
freeze-up, and the preservative saits would be penetrated and non-leach- j -
~.
able (upon loss of ammonia) in the spring when water levels would be
restored. Grease-types'penetrate too slowly, and paste-types remain
- leachable and not suitable for this difficult requirement.
; 5. The'preservative of aspects of this invention is stable in
closed containers and is not affected by freezing, as is ~oodtreat AA
(penta emulsion type).
6. The preservative of aspects of this invention penetrates wet
creosoted wood and is therefore particularly well suitable to retreatment
: .
of old creosoted poles.
- 34 -
.
