Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
23443-276
The present invention relates to a water-dilutable
concentrate, an aqueous medium, and a process for the treatment
of wood.
Wood is understood to mean all types of wood and wood
materials exhibiting an open-pore structure susceptible to the
application methods of impregnating technique. Wood materials
include, for example, plywood, blockboards, and chipboards.
Wood preservatives are understood to mean wood-
protective biocidal active agents which do not inhibit air drying,
namely primarily those with insecticidal and/or fungicidal
activity.
The application leads to the impregnating technique of
wood and related techniques. In this connection, an effective
and permanent wood protection is intended. It is considered
important herein that the binder, or the binder and the wood
preservative, are transported in sufficient concentration into
the wood parts to be protected (penetration) and are fixed therein.
In certain cases, a decorative function can be additionally
obtained in the wood surface.
The invention is not directed to the wood varnishing
technique. In the latter process, a decorative function is
intended in the surface of the wood, but in any event no penetra-
tive effect is desired (coating agents for the surface coating of
wood).
German Patent 2,838,930 and German Offenlegungschrifts
3,026,300 and 3,200,782 have been known in the field of the
application. (Furthermore, the German patent application serial
7451/15-ko - l -
O.Z. 3935
No. P 32 14 196 exists in the field of the application.) The
wood treated with the agents described therein, which contain
customary driers (siccatives), exhibits a drying characteristic
in air drying that is not always satisfactory for practical
requirements. Usually, at least 24 hours of drying will be
required before it is possible to expose impregnated wood to
outside weathering wi.thout having to expect washing out of binder
or binder and wood preservative.
The object resides in overcoming this drawback and
providing a water-dilutable concentrate, an aqueous medium, and
a process for wood treatment so that the drying period of the
air drying may be substantially reduced.
Thus one aspect of the present invention provides a
composition in the form of a water-dilutable concentrate or
aqueous medium for the treatment of wood, comprising: a macro-
molecular organic binder with an unsaponifiable carbon chain;
the binder consisting of at least one carboxylated diene polymer
having an acid number of 50 to 250, an average content of olefinic
double bonds corresponding to an iodine number of at least 200
and a relative molecular weight (Mn) of 500 to 5,000 wherein in
case of more than one polymer binders being used none of them has
an iodine number of less than lO0; the carboxy groups of the
binder being partially or fully neutralized with a base selected
from the group consisting of alkaline alkali metal compounds,
ammonia, low molecular water-soluble monoamines that do not
inhibit air-drying, and mixtures thereof, wherein the strength
and the amount of the base are selected such that the pH of the
~l2~
concentrate i5 6 to 11.5, and the binder is in the dissolved
state.
Another aspect of the present invention provides a
process for the treatment of wood, which process comprises
impregnating wood with the above-mentioned aqueous treatment
medium and air-drying the so-treated wood.
The water-dilutable concentrate of the invention
contains a macromolecular organic binder, i.e. a polymer.
I. The polymers of this invention can be copolymers
of (a) at least one 1,3-(cyclo)diene, such as 1,3-butadiene and
cyclopentadiene, or (b) at least one 1,3-(cyclo)diene and at
least one copolymerizable olefin, such as styrene, or (c) the
monomer according to (a) or (b) and additionally at least one
mono- or diester of an ~,~-olefinically unsaturated mono- or
dicarboxylic acid, on the one hand, and at least one ,~~olefin-
ically unsaturated mono or dicarboxylic acid and/or a half ester
of the dicarboxylic acid, on the other hand.
The unsaturated mono-carboxylic acids are, for example,
acrylic and methacrylic acid. The unsaturated dicarboxylic acids
are, for example, maleic and fumaric acid. Preferred alcohol
components of the esters are monohydric Cl- to C10-alkanols,
optionally containing ether groups, or mixtures thereof.
The polymers are basically known and can be produced
according to conventional methods.
II. The polymers of this invention are preferably
adducts of the basic polymers characterized hereinbelow and an
acid component selected from the group consisting of ~,~-olefin-
ically unsaturated dicarboxylic acids, their anhydrides and half
esters and mixtures thereof, and optionally, in addition, one or
more diester of the dicarboxylic acids.
The basic polymers are homopolymers of 1,3-(cyclo)dienes
or copolymers of mixed 1,3-(cyclo)dienes or copolymers of at least
one 1,3-(c~yclo)diene and at least one copolymerizable olefin.
They can be modified by isomerization, partial cyclization, or
partial hydrogenation.
The monomers (see paragraph I) mentioned by way of
example in connection with the first group of polymers of this
invention also apply as examples for the basic polymers and acid
components of the adducts, i.e. the second group of polymers.
The adducts which contain ester groups can be obtained
by direct or indirect methods, i.e. by subsequent partial
esterification of the adducts.
Preferred alcohol components for subsequent esterifica-
tion are saturated or oleflnically or acetylenically unsaturated,
monohydric Cl- to C10-alcohols, which optionally contain ether
groups, or mixtures thereof. The adducts modified by subsequent
esterification are preferred. They preferably exhibit an acid
number of 50-125 ~mg KOH/g]. The acid number means the amount of
KOH(mg) required to neutralize one gram of the acldic test
material and the iodine number means the amount of iodine (g)
required to saturate 100 gram of the unsaturated test material.
The polymers are basically known and can be produced in
accordance with conventional methods ~German Patent 2,~38,930).
Preferred bases used to neutralize the carboxy groups
of the binder includes alkali metal hydroxides, alkali metal
carbonates, alkali metal bicarbonates, ammonia and triloweralkyl-
amine, particularly preferred bases includes for example ammonia
and triloweralkylamines such as triethylamine.
The wood preservatives utilized can be the customary
ones.
Suitable, water-insoluble wood preservatives are, for
example, 2,5-dimethylfuran-3-carboxylic acid N-methoxy-N-cyclo-
hexylamide, tributyltin benzoate, tributyltin naphthenate, ~-
hexachlorocyclohexane, pentachlorophenol, pentachlorophenol
laurate, 2-mercaptobenzothiadiazole-2,2-(methoxycarbonylamino)-
benzimidazole, N,N-dimethyl-N'-phenyl-MI-(fluorodichloromethyl-
thio)sulfamide, N,N-dimethyl-NI-p-tolyl-N'-(fluorodichloromethyl-
thio)sulfamide, carbamates, dithiocarbamates~ phosphoric acid
esters, phosphonic acid esters, thiophosphoric acid esters,
dithiophosphoric acid esters, thionophosphoric acid esters,
o-phenylphenol, hydroxyquinoline derivatives, endosulfan,
pyrethroids, and 3-iodo-2 propynylbutyl carbamate.
Suitable water-soluble wood preservatives are, for
~xample, alkali fluorides, silicofluorides, such as MgSiF6,
alkali arsenates, borates, and salts of lead, tin, cadmium,
nickel, cobalt, manganese, copper, mercury, zinc, and chromium,
as well as (C12- to C14-alkyl)benzyldimethylammonium chloride.
Conventional additives are, for example, pigments,
pellicle-preventing agents, stabilizers, surfactants, viscosity
regulators, and water-compatible solvents.
Suitable water-compatible organic solvents are, for
example, isopropanol, butanols, diacetone alcohol, alkyl
-- 5 --
"Cellosolves", and dimethyl ethers of glycols. The solvents or
solvent mixtures can be utilized in amounts of up to 100 parts by
weight, based on 100 parts by weight of binder. They are prefer
ably employed in quantities of 5-50 parts by weight, especially
preferably 10-40 parts by weight.
Pore-sealing additives should not be added in the
composition of the present invention, and they are understood to
mean those additives which, based on their type and their
concentration in the treatment medlum during application, cause
pore closure of the wood and thereby would substantially impede
the desired penetration effect of the treatment medium.
Additives of the above-described kind can be admixed in
quantities customary under practical conditions. The type and
amount are in all cases dependent on the material to be treated
in each particular case, its purpose of use, and the treatment
method, and they can be readily determined by a few orientation
experiments.
Since the binders utilized in the treatment media of
this invention are air-drying, i-t is generally unnecessary to add
to them additional resins as crosslinking agents. Additional
binders acting as crosslinking agents -- optionally with heat
treatment -- can, of course, likewise be included, such as, for
example, water-soluble aminoplasts or phenolic resins, unless the
effect desired along the lines of the objective of the present
invention is considerably impaired.
The treatment media of this invention generally have a
binder content o~ 1-40% by weight, preferably 5-30% by weight, and
~ d~`nn2,k 6 -
c~,r~
they can be applied in accordance with all known methods of the
prior art (cf. DIN 68 800, page 3). In this context, the
protective effect attainable is -- as is known to those skilled
in the art -- narrowly linked with the treatment method.
An especially effective method is an impregnating method
t~7oro~ h
wherein the wood is subjected to t~e~h impregnation, if desired
under pressure or vacuum.
The following examples serve for explaining the
invention. Parts should be understood to mean parts by weight,
and percent should be understood to mean percent by weight, unless
indicated otherwise.
Examples
Basic Polymer 1
A polybutadiene characterized as follows:
Mn (determined by vapor pressure osmosis in chlorobenzene):
about 1,700;
Iodine number [g iodine/100 g] (DIN 53 241): 445;
Double bond distribution (IR analysis) in %, based on total
double bonds:
73 cis and 25 trans (in structural units obtained by
1,4-polymerization of 1,3-butadiene); 2 vinyl (in
structural units obtained by 1,2-polymerization of
1,3-butadiene);
Viscosity [Pa-s] (DIN 53 214, 20 C): 0.8
Basic Polymer 2
-
A polycyclopentadiene characterized as follows:
Iodine number [g iodine/100 g]: 170-180;
Melting point: about 145 C;
Color (Gardner): 5
Density [g~cm3]: 1.1 to 1.2
Preparation of Binder 1
.
1,200 parts of basic polymer 1 and 300 parts of maleic
anhydride (MA) are heated in the presence of 1.5 parts of
acetylacetone and 1.6 parts of the commercially available anti-
oxidant N,N'-diphenyl~p-phenylenediamine under nitrogen for one
hour at 180 C and then for 3 hours at 190 C. The thus-obtained
MA adduct contains < 0.1% free MA and has an acid number of 218
mg KOH/g (titratlon in pyridine/water).
Preparation of Binder 2
Under nitrogen, 233 parts of basic polymer 1, 58.3
parts of basic polymer 2, 1.9 parts of copper naphthenate, and
0.1 part of acetylacetone are heated to 120-140C until a homo-
geneous mixture has been obtained. After adding 63.9 parts of
MA, the reaction mixture is heated within one hour at a rising
temperature up to 190C, and left for 3 hours at this temperature.
The reaction mixture is then cooled to 130 C, combined with 58.7
parts of ethylene glycol monoethyl ether (ethyl glycol), and left
for one hour at this temperature. The resultant half ester has
an acid number of 83 mg KOH/g.
~ ` ~
~ Preparation of Concentrate 1 and Treatment
~edium 1
_ _ _ _ _ _ ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ :
The components are mlxed in the indicated sequence
at 40-60 C. `
Binder 1 35.0 parts -
: Ethyl glycol L7.5 parts
~ -Hexachloroc~clohexane 2~3 parts
2,5-Dimethylfuran-3-carboxylic acid
.N-methoxy-N-cyclohexylamide (50~ in -
aliphatic naphtha fraction)12.5 parts
Drier (in an aliphatic naphtha
fraction) 6.0 parts
NH3 Solution (12.8% strength~19.0 parts
Water 7.7 parts
100.0 parts
One part of concentrate 1, obtained as a clear
sollltion, is mixed with 4 parts of water. The thus-obtained
treatment medium 1 is a clear solution and has a pH of 9.5.
The condition of concentrate 1 and treatment medium 1 :
20 iB nearly unchanged after a one-month storage~in a closed
container at about 60 C~ ~ .
, ~ .. ... .
~ .
~ d~ l$ ~
.. .
Preparation of Treatment Medium 2
The components are mixed at room temperature in the -
indicated sequence.
B.~nder 2 .104.1 parts
Ethyl glycol -- 15.0 parts
Ethoxylated nonylphenols S.0 parts
y -Hexachlorocyclohexane . - 2.6 parts
-2,5-Dimethylfuran-3-carboxylic acid
N-methoxy-N-cyclohexylamide ~50% in
. 10 aliphatic naphtha fraction)15.6 parts
- Drier (in an aliphatic naphtha
fraction) 2.5 parts
. . Triethylamine (about 50% strength) 40.0 parts
Water ~ 335.0 -parts
~ 519.8 parts
The thus-obtained treatment medium 2 is a clear
solution and has a pH of 10.1. Its condition is nearly
unchanged after a one-month storage in a closed container
at about 60 C.
. The treatment media 1 and 2 of this invention show
a very good shelf stability which is not inferior to that of
the treatment media of the above-discussed state of the art.
.
Tests for Air-Drying Characteri7~ation
__ ______ ___ ~______________________
The drying behavior during air drying of wood
treated according ~o this inventlon as compared to the state
of the art is characterized by the dust drying times of
coatings of the treatment media on glass plates. Treatment
-- 10 --
. ' ' ' .
media 3 and 4 of this invention and,,for comparison~ treat-
ment medium A according to German Patent 2,838r930 are used
in this test. They correspond to the following formulations:
.
- Treatment Medi;um 3
Binder 1 . 30.0 parts
NH3 Solution (,25% strength) 8.7 parts
Cobalt octoates and lead octoates
in an aliphatic naphtha fraction
- (2.25% Co,,14.0% Pb)1.2 parts
Water 60o l parts
, 100.0 parts
Treatment Medi'um 4
Binder 2 30.0 parts
NH3 Solution (25% strength) 7.2 parts
Cobalt octoates and lead octoates
in an aliphatic naphtha fraction
(2.25% Cot 14.0 Pb)1.2 parts
Water . _ 6L.6 parts
100~0 parts
Treatment Medium A
Binder (German Patent 2,838,930,
column 7~ Example 1)30.0 parts
- Acetic acid 4. 6 parts
Cobalt octoates and lead octoates
in an aliphatic naphtha fraction
(2.25% Co, 14.0% Pb)1.2 parts
Water 6'4'.2 p'arts
100.0 p~rts
: ~,-- . .
~ - . .
~ The treatment media are applied on glass plates
with a 100 ~m coating Xnife and stored at 20 C. The dust
drying times are'determined according to DIN 55 934 (table).'
.
Table: Air Drying on Glass Plates
_ _ _ _ _ _ _ .
Treatment Me'diu'm'' '' D'us't' Dr'y'i~'T'ime `[h]
3 about 3.5
4 about 3.5
A about 22
Similar results are obtained by adding customary
amounts of wood preservatives to t-eatment media 3, 4, and ~.
- 12 -
