Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
3~1'7
3698A
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to particle board binders and
is more particularly concerned with the use of organic
polyisocyanates as particle board binders, with compositions
for said use, and with the particle boards so prepared.
2. Description of the Prior Art
The use is now widely recognized of organic poly-
- isocyanates, particularly toluene diisocyanate;
1~ methylenebis(phenyl isocyanate~, and polymethylene
polyphenyl polyisocyanates, as binders, or as a component
or a binder,for the preparation of particle boards; see,
for example, U. S. Patents 3,~28,592; 3,440,189; 3,557,263;
3,~36,199; 3,870,665; 3,919,017 and 3,930,110.
In a typical process the binder resins, optionally
in the form of a solution or aqueous suspension or
emulsion, are applied to or admixèd with the particles
of cellulosic material, or other types of material
capable of forming particle boàrds, using a tumbler
apparatus or blender or other form of agitator. The
mixture of particles and binder is then formed into a
mat and subjected to heat and pressure using heated platens.
The process can be carried out in a batch operation or
continuously. To avoid adhesion of the board so formed
to the heated platens it has hitherto been necessary to
interpose a sheet, impermeable to isocyanate, between the
surface of the board and the platen during the forming
process, or to coat-the surface of the platen, prior to
each molding operation, wi~h an appropriate.release agent
or to coat the surface of the partisles themselves with a
- ~ ~. Z38~7 3698A
material which will not adhere to the ~lat:en. Any
of these alternatives, particularly where the process
is being operated on a continuous basis, is cumber-
some and a drawback to what is otherwise a very
satisfactory method of making a particle board with
highly attractive structural strength properties.
We have now found that the above drawbacks to
the use of organic isocyanates as particle board
binders can be minimlzed in a very satisfactory
manner by incorporating certain phosphorus-containing
compounds as internal release agents in the isocyanate
compositions so utilized. We are aware of U. S.
Patent 4,024,088 which describes the incorporation
of phosphorus-containing compounds as internal release
agents in thè preparation of polyether polyurethanes.
We have found that the phosphorus compounds disclosed
in this reference are not suitable for use in the
process of the present invention.
SU~RY OF THE INVENTION
This invention comprises an improved process for
the preparation of particle board in which particles
of organic material capable of being compacted are
- contacted with a polyisocyanate and the treated
particles are subsequently formed into boàrds by
the application of heat and pressure, wherein the
improvement comprises contacting said particles, in
addition to the treatment with polyisocyanate, with
from about 0.1 to 20 parts, per 100 parts by weight
of polyisocyanate, of a phosphate selected from the
class consisting of
~..238~7
3698A
6a) acid phosphates of the formulae
O O
1` ~
RO - P - OH and~RO) 2 ~ - OH
OH
tI) ~II)
and the ammonium, alkali metal and alkaline
earthmetal salts thereof;
(b) pyrophosphates rQpresented by those derived
from the acid phosphates (I) and (II) and
mixtures of (I) and (II);
(c) The O-monoacyl derivatives of the acid
phosphates (I) and (II) having the formulae
O O
RO - ~ OCORl and (RO)2~ - OCOR
I
OH
(V) (VI)
(d) carbamoyl phosphates having the formula
O
R2NHCO - O -~(OR)
OH
(VII)
and the ammonium, alkali metal and alkaline
earth metal salts of the compounds of formula
(VII);
(e) branched polyphosphates of the formulae
O O O O O
RO -~ - O-~(OR~2 and (RO)2P- O -P- O ~ (OR)2
o -P(OR)2 (VIII) ¦ O (IX)
~ o -~(OR)2
(f) polyphosphates cor~esponding to the general formula
~ Z~8~7 3698A
[ROP - ~n (X)
including the cyclometaphosphates
tn = 3); and
(g) mixtuxas of two or more of said compounds; -
wherein, in the various formulae shown above, each R is
independently selected from the class consisting of alkyl
having from 8 to 35 carbon atoms, inclusive, alkenyl
having from 8 to 35 carbon atoms, inclusive and,
R'-(O-IH-CH~
wherein R' is alkyl having from 8 to 35 carbon atoms,
inclusive, one of A and B represents hydrogen and the
other is selected from the class consisting of hydrogen
and methyl, and n is a number having an averaga valu~
from 1 to 5; Rl is hydrocarbyl from 1 to 12 carbon
atoms, inclusive; R2 is selected from the class con-
sisting of hydrocarbyl from 1 to 12 carbon atoms and
hydrocarbyl substituted by at leas~ one additional
--NHCOO -P(OR)~ group wherein R has the significance
defined above; and n is~an integer. I
The invention also comprises novel compositions com- I
prising organic polyisocyanates having incorporated therein
one or more of the aforesaid compounds. The invention also
comprises particle board prepared in accordance with the
aforesaid process.
The term "alkyl having from 8 to 35 carbon atoms" means
a saturated monovalent aliphatic radical, straight chain or
--5--
.
~.2~7 3698A
branched chain, which has the stated number of carbon
atoms in the molecule. Illustrative of such groups are
octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetra-
decyl, pentadecyl, hexadecyl, heptadecyl, octadecyl,
nonadecyl, eicosyl, henei.cosyl, docosyl, tricosyl,
pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl,
triacontyl, pentatriacontyl, and the like, including
isomeric forms thereof.
The term "alkenyl having from 8 to 35 carbon atoms"
means a monovalent straight or branched chain aliphatic
radical containing at least one double bond, and having the
stated number o~ carbon atoms in the molecule. Illustrative
of such groups are octenyl, nonenyl, decenyl, undecenyl,
dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl,
heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, heneicosenyl,
docosenyl, tricosenyl, pentacosenyl, triacontenyl, pentatria-
-contenyl, and the like, including isomeric forms thereof.
The term "pyrophosphates ~ derived from the acid
phosphates (I) and (II) and mixtures of (I) and (II)" has
the following meaning. The acid phosphates (I) and (II) are
generally prepared in the form of mixture5 of the monoacid
phosphate tII) and the diacid phosphate ~I) which mixtures
are produced by reaction of the corresponding alcohol ROH,
wherein R is as above defined, with phosphorus pentoxide in
accordance with procedures well-known in the art for the
preparation of acid phosphates; see, ~or example, Kosolapoff,
Organophosphorus Compounds, pp 220-221~ John Wiley and Sons,
Inc., New York, 1950. The mixture of the mono- and di-acid
phosphates so obtained can be separated, if desired, for
example by fractional crystallization of the baxium and like
~ ~ 3698A
38~L~
salts as described in the above cited reference. The
individual acid phosphates or mixtures of the two can be used
in the process of the invention. The pyrophosphates (III) and
~IV) are readily obtained from the corresponding acid phosphates
(II) and (I) respectively, by reaction of the latter with a
dehydrating agent such as carbonyl chloride, aryl or alkyl
monoisocyanates and polyisocyanates, N,N'-dihydrocarbyl-
carbodiimides, and the like in accordance with procedures well-
known in the art; see, for example, F. Cramer and M. Winter,
Chem. Ber. 94, 989 (1961)i ibid 92, 2761 (1959); M. Smith, J. G.
Moffat and H. G. Khorana, J. Amer. Chem. Soc. 80, 6204 (1958);
F. Ramirez, J. F. Màrecek and I. Ugi, JACS 97, 3809 (1975).
The individual acid phosphates (I) and (II) can be separately
converted to the corresponding pyrophosphates or mixtures of
the two types of acid phosphate (I) and (II) can be converted
to the corresponding mixture of pyrophosphates.
In the case of the acid phosphates having the formula (II)
above the corresponding pyrophosphates are those represented
by the formula:- !
o o
~ ~
(RO)2P- O -P(OR~2 (III)
wherein R has the meaning hereinbefore defined. In the case
of the acid phosphates having the formula (I) above
the corresponding pyrophosphates are a complex mixture whose
average composition is represented by the formula:-
01 - 0-
HO ~-O ~ - -OH (IV)
O x
wherein x is a number having an average value of 1 or higher
and R has the meaning hereinbefore defined.
--7--
~-Z~7 3698A
I
The term "hydrocarbyl from 1 to 12 carbon atoms,
inclusive" means the monovaIent radical obtained by
removing one hydrogen atom from the parent hydrocarbon
having the stated carbon atom content. Illustrative
of such groups are alkyl such as methyl, ethyl, propyl,
butyl, pentyl, hexyl, octyl, decyl, dodecyl and the
like including isomeric forms thereof; alkenyl such as
vinyl, allyl, butenyl, pentenyl, hexenyl, octenyl,
decenyl, dodecenyl and the like, including isomeric
forms thereof; aralkyl such as benzyl, phenylpropyl,
phenethyl, naphthylmethyl, and the likei aryl such
as phenyl, tolyl, xylyl, naphthyl, biphenylyl and
the like; cycloalkyl such as cyclobutyl, cyclopentyl,
cyclohexyl, cycloheptyl, cyclooctyl, and the like,
including isomeric forms thereof; and cycloalkenyl
such as cyclopentenyl, cyclohexenyl, cycloheptenyl,
cyclooctenyl and the like including isomeric forms
thereof.
The term "alkali metal" has its well recognized
meaning as being inclusive of lithium, sodium, potassium,
rubidium and caesium. The term "alkaline earth metal"
also has its well recognized meaning as being inclusive
of calcium, strontium, m~agnesium and barium.
DETAILED DESCRIPTION OF THE INVENTION
The process of the invention is carried out
substantially in accordance with methods previously
described in the art in which an organic polyisocyanate
is used as the binder resin, or a component thereof,
~see, for example, German Offenlegungsschrift 2610552
and U. S. 3,428,592) with the chief exception that a
-8-
~ 3~1~ 3698A
phosphate as hereinbefore defined is employed in
combination with the isocyanate composition which is
used to treat the particles which are to be bonded
together to form the particle board.
Thus, particle board is produced according to the
invention by bonding together particles of wood or
other cellulosic or organic material capable of being
compacted using heat and pressure in the presence o~ a
binder system which comprises a combination of an organic
polyisocyanate and a phosphate as herein~efore defined,
hereinafter referred to as the "phosphate release agent".
~he polyisocyanate and the phosphate release agent
can be brought into contact with the particles as
separate, individual components or, in a preferred
embodiment, the polyisocyanate and phosphate are brought
into contact with the particles either simultaneously
or after admixture. Whether the polyisocyanate and
phosphate are introduced separately or in admixture, they
can be employed neat, i.e. without diluents or solvents
or one or other or both can be employed in the form of
aqueous dispersions or emulsions.
The polyisocyanate component of the binder system
can be any organic polyisocyanate which contains at least
two isocyanate groups per molecule. Illustrative of
~5 organic polyisocyanates are diphenylmethane diisocyanate,`
m- and p-phenylene diisocyanates,chlorophenylene diisocyanate,
~,~-xylylene diisocyanate, 2,4- and 2,6-toluene diisocyanate
and the mixtures of these two isomers which are available
commercially, triphenylmethane triisocyanates, 4,~'-
diisocyanatodiphenyl ether, and polymethylene polyphenyl
_g_
3~saA
3~:L7
polyisocyanates. The latter polyisocyanates are mixtures
containing from about 25 to about 90 percent by waight of
methylenebis(phenyl isocyanate) the remainder of the
mixture being polymethylene polyphenyl polyisocyanates of
functionality higher than 2Ø Such polyisocyanates and
methods for their preparation are well-known in the art; see,
for example, U. S. Patents 2,683,730; 2,950,263; 3,012,008
and 3,097,191. These po~yisocyanates are also available in
various modified forms. One such form comprises a poly-
methylene polyphenyl polyisocyanate as ahove which has beensubjected to heat treatment, generally at temperatures from
about 150C to about 300~, until the viscosity (at 25C)
hasbeen increased to a value within the range of about 800
to 1500 centipoises. Another modified polymethylene polyphenyl
polyisocyanate is one which has been treated with minor amounts
of an epoxide to reduce the acidity thereof in accordance
with U. S. Patent 3,793,362.
The polymethylene polyphenyl polyisocyanates are the pre-
ferred polyisocyanates for use in the binder systems of the
invention. Particularly preferred polymethylene polyphenyl
polyisocyanates are those which contain from about 35 to about
65 percent by weight of methylenebis(phenyl isocyanate).
When the organic polyisocyanate is to be employed as
binder system in the form of an aqueous emulsion or dispersion
in accordance with the invention, the aqueous emulsion or
dispersion can be prepar~d using any of the techni~ues known
in the art for the preparation of aqueous emulsions or dis-
persions, prior to use of the composition as the binder.
Illustratively, the polyisocyanate is dispersed in water in
the presence of an emulsifying agent. The latter can be any of
10-- .
3698A
3~:L7
the emulsifying agents known in the art including
anionic and nonionic agents. Illustrative of nonionic
emulsifying agents are polyoxyethylene and polyoxypropylene
alcohols and block copolymers of two or more of ethylene
oxide, propylene oxide, butylene oxide, and styrene;
alkoxylated alkylphenols such as nonylphenoxy poly(ethylene~
oxy)ethanols; alkoxylated aliphatic alcohols such as
ethoxylated and propoxylated aliphatic alcohols containing
from about 4 to 18 carbon atoms; glycerides of saturated
and unsaturated fatty acids such as stearic, oleic, and
ricinoleic acids and the like; polyoxyalkylene esters of
fatty acids such as stearic, lauric, oleic and like acids;
fatty acid amides such as the dialkanolamides of fatty
acids such as stearic, lauric, oleic and like acidsO A
detailed account of such materials is found in Encyclopedia
of Chemical Technology, Second Edition, Vol. 19, pp. 531-554,
1969, Interscience Publishers, New York.
The formation of the emulsion or dispersion can be carried
out at any time prior to its use as the binder composition, but,
preferably, it is carried out within about 3 hours prior to
use. Any of the methods conventional in the art or the
preparation of aqueous emulsions can be employed in preparing
the aqueous polyisocyanate emulsions employed in the process of
the invention. Illustratively, the emulsion is for~ed by
bringing the polyisocyanate, emulsifying agent and water
together under pressure using a conventional spray gun in
which the streams of water and polyisocyanate impinge and
are mixed under turbulent conditions in the mixing chamber
of the spray gun. The emulsion so formed is discharged in the
form of a spray which is applied to the cellulosic
.
~ ~. 23~7 3698A
particles to be Eormed into boardstock in the manner discussed
below.
As discussed above,the phosphate release agent can be
brought into contact with the particles as a separate com-
ponent in which case it is employed in neat ~orm, i.e.without diluents,or as an aqueous solution or dispersion.
Preferably the phosphate either neat or in diluted form
when used alone i.e. separately from the polyisocyanate,is
presented to the particles in the form of a spray. However,
in a preferred embo~iment of the invention the phosphate
release agent and the polyisocyanate are employed together
in a single composition. This can be accomplished in
several ways. Thus, when the polyisocyanate is employed as
binder resin without diluents such as water, the phosphate
release agent can be incorporated in the polyisocyanate by
simple admixture. Where the polyisocyanate is employed as
binder resin in the form of an aqueous emulsion the phosphate
release agent can be added as a separate component during
the formation of the emulsion or after its formation or, in
a particularly advantageous embodiment, the phosphate is
premixed with the organic polyisocyanate prior to emulsification
of the latter. Thus, the organic polyisocyanate and the
phosphate release agent.can be premixed and stored for any
desired period prior to formation of the emulsion. Further,
when an emulsifying agent is employed ln preparation of the
emulsion said agent can also be incorporated into the mixture
of organic polyisocyanate and phosphate release agent to
form a storage stable composition which can be converted, at
any desired time, to an aqueous emulsion for use as a binder
resin by simple admixture with water.
-12-
3698~ 1
-~.23~7
When the polyisocyanate is employed as binder in the form
of an aqueous emulsionl the proportion of organic polyisocyanate
present in the said aqueous emulsion is advantag&ously within
.
the range of about 0.1 to abou~ 99 percent by weight and
preferably within the ran~e of about 25 to about 75 percent by
weight.
Whether the phosphate release agent is introduced as a
separate component or in combination with the polyisocyanate,
the proportion of phosphate release agent employed is within
the range of about 0.1 to about 20 parts by weight, per 100
parts of polyisocyanate and, preferably, is within the range of
about 2 to about 10 parts by weight, per 100 parts of poly-
isocyanate. The proportion of emulsifying agent required to
prepare the aqueous emulsion is not critical and varies
lS according to the particular emulsifying agent employed but is
generally within the range of about 0.1 to about ~0 percent by
weight based on polyisocyanate.
The starting material for the particle board comprises
particles of cellulosic and the like material capable of being
compacted and bonded into the form of boards. Typical such
materials are wood particles derived from lumber manufacturing
waste such as planar shavings, veneer chips, and the like.
Particles of other cellulosic material such as shredded paper,
pulp or vegetable fibres such as corn stalks, straw, bagasse
and the like, and of non-cellulosic materials such as scrap
polyurethane, polyisocyanurate and like polymer foams can also
be used. The methods for producing suitable particles are well
known and conventional. If desired, mixtures of cellulosic
particles may be used. Particle board has been successfully
produced, for example, from wood particle mixtures containing
-13-
~ .3~7 3698A
up to about 30~ bark.
The moiqture content of the particles suitably may range
from about 0 to about 24 percent by wei~ht. Typically~ particlcs
made from lumber waste materials contain about 10 - 20% moisture,
and may be used without first being dried.
Particle board is fabricated by spraying the particles
with the components of the binder composition, either separately
or in combination, while the particles are tumbled or agitated
in a blender or like mixing apparatus. Illustratively, a
total of about 2 to 8% by weight of the binder system (excluding
any water present therein) is added, based on the "bone dry"
weight of the particles, but higher or lower amounts of
binder resin may be used in any given application. If desired,
other materials, such as wax sizing agents, fire retardants,
pigments and the like, may also be added to the particles during
the blending step.
After blending sufficiently to produce a uniform mixture,
the coated particles are formed into a loose mat or felt,
preferably contalning between about 4~ and about 18~ moisture
by weight. The mat is then placed in a heated press between
caul plates and compressed to consolidate the particles into
a board. Pressing times, temperatures and pressures vary
widely depending on the thickness of the board produced, the
desired density of the board, the size of the particles used,
and other factors well known in the art. By way o example,
however, for 1/2" thick particle board of medium density,
pressures of about 300 to 700 psi and temperatures of about
325 - 375F are typical. Pressing times are typically
about 2 - 5 minutes. Because a portion of the moisture
present in the mat reacts with polyisocyanate to form
-14-
3698A
~`.Z3~7
polyurea, as described earlier, the level of moisture present
in the mat is not as critical with isocyanate binders as with
other binder systems.
The above-described process can be carried out on a batch
basis, i.e. individual sheets of par-ticle board can be molded
by treating an appropriate amount of particles with the binder
resin combination and heating and pressing the treated material.
Alternatively,the process can be carried out in a continuous
manner by feeding treated particles in the form of a continuous
web or mat through a heating and pressing zone defined by upper
and lower continuous steel belts to which, and through which,
the necessary heat and pressure are applied.
Whether the process of the invention is carried out
in a batchwise or continuous manner, it is found that the
particle board produced using the polyisocyanate and
phosphate release agent combination of the invention is
released readily from the metal plates of the press used
in its formation and shows no tendency to stick or adhere
to said plates. This is in direct contrast to previous
experience with the use of polyisocyanates alone as binder
resins as discussed above~
While any of the phosphate release agents defined
hereinbefore can be used,-either alone or in combination,
in the process of the invention, it is preferred to use
the pyrophosphates (III) and (IV) or mixed pyrophosphates
derived from mixtures of the acid phosphates (I) and (II).
Thus, the free hydroxyl groups present in the pyrophosphates,
or any free hydroxyl groups present in the form of uncon-
verted acid phosphate starting material, are generally
sufficiently hindered as to be unreactive at ambient
-15-
~.238~7 3698A
temperatures with the polyisocyanate employed in
the process of the invention and the pyrophosphates
can be stored in combination with said polyisocyanate
for prolonged periods wi-thout showing any evidence of
deterioration. However, when the mixture of pyrophosphate
and polyisocyanate is emulsified and employed in the
process of the invention the processing temperature and
the steam generated in the formation of the particle
board are believed to result in hydrolysis of the
pyrophosphate with regeneration of the corresponding
acid phosphates which latter then serve to facilitate
subse~uent release of the particle board from the
plates of the press. It is to be understood that the above
theory is presented for purposes of explanation only and
is not to be construed as limiting in any way the scope
of the present invention.
As set forth above, the monoacid phosphates (II)
and the di-acid phosphates ~I) and the salts thereof
which are employed in the process of the invention are
obtained by conventional procedures such as reaction of
the corresponding alcohol ROH, wherein R is as herein-
above defined, with phosphorus pentoxide; Kosolapoff,
ibid. As will be obvious to one skilled in the art,
it is possible by using mixtures of two or more
different alcohols in the above reaction to obtain a
corresponding mixture of acid phosphates ~I) and or (II)
wherein the various components of the mixture have
different values of the group R. As also set forth above
the mixture of mono- and di-acid phosphates obtained in
the above reaction can be separated into its individual
-16-
3698A
~L~.23~:~7
components by conventional methods, such as fractional
crystallization and -the like, and the individual compounds so
obtained can be employed in the process of the invention.
Alternatively, and preferably, the mixture of mono- and di-acid
phosphates obtained in the above reaction can be employed as
sucn, withoutseparation, into its components, in the process
of the invention or can be converted to the corresponding
mixture of pyrophosphates using the procedures discussed here-
inbefore, which latter mixture is then employed in the process
of the invention~
Illustrative of the acid phosphates of the formula (I)
above which can be employed individually or in combination
with other acid phosphates in the process of the invention are:
mono-O-octyl, mono~O-nonyl, mono-O-decyl, mono-O-undecyl,
mono-O-dodecyl, mono-O-tridecyl, mono-O-tetradecyl, mono-O-penta~
decyl, mono-O-hexadecyl, mono-O-heptadecyl, mono-O-octadecyl,
mono-O-nonadecyl, mono-O-eicosyl, mono-O-heneicosyl, mono-O-
docosyl, mono-O-tricosyl, mono-O-pentacosyl, mono-O-hexacosyl,
mono-O-heptacosyl, mono-O-octacosyl, mono-O-nonacosyl,
mono-O-triacontyl, mono-O-pentatriacontyl, mono-O-dodecenyl,
mono-O-tridecenyl, mono-O-tetradecenyl, mono-O-pentadecenyl,
mono-O-hexadecenyl, mono-O-heptadecenyl, mono-O-octadecenyl,
mono-O-nonadecenyl, mono-O-eicosenyl, mono-O-heneicosenyl,
mono-O-docosenyl, mono-O-tricosenyl, mono-O-pentacosenyl,
mono-O-triacontenyl and mono-O-pentatriacosenyl di-acid phosphates
and the diacid phosphates in which the esterifying radical
is that derived from lauryl and like monohydric alcohols which
have been capped using from about 1 to 5 moles of ethylene oxide.
Illustrative of the acid phosphates of the ~ormula (II)
above which can be employed individually or in combination with
-17-
~.23~7
other acid phosphates in the proces3 of the invention are:
O,O-di(octyl), O,O-di(nonyl), O,O-di(d~cyl), O,O-di(undecyl),
O,O-di(dodecyl), O,O-di(tridecyl), O,O-di(tetradecyl), O,O-di-
- (pentadecyl), O,O-di(hexadecyl), o,O-di(heptadecyl), O,O-di-
(octadecyl), O,O-di(nonadecyl), O,O-di(eicosyl), O,O-di(heneicosyl),
O,O-di(docosyl), O,O-di(tricosyl), O,O-di(pentacosyl), O,O-di-
(hexacosyl), O,O-di(heptacosyl),O,O-di(octacosyl), O~O-di-
(nonacosyl), O,O-di(triacontyl), O,O-di(pentatriacontyl), O,O-di-
(dodacenyl), O,O-di(tridecenyl), O,O-di(tetradecenyl), O,O-di-
(pentadecenyl), O,O-di(hexadecenyl), O,O-di(heptadecenyl),
O,O-di(octadecenyl), O,O-di(nonadecenyl), O,O-di(eicosenyl),
O,O-di(heneicosenyl), O,O-di(docosenyl), O,O-di(tricosenyl),
O,O-di(pentacosenyl), O,O-di(triacontenyl), and O,O-di(penta-
triacosenyl) mon~acid phosphates, and the diesterified mono acid
phosphates in which the esterifying radical is that derived from
lauryl and like monohydric alcohols which have been capped with
about 1 to 5 moles of ethylene oxide. Illustrative of the
latter typesof phosphate which are available, in admixture with
the corresponding diacid phosphates,are the materials marketed
under the trade name Tryfac by Emery Industries Inc.
Illustrative of the pyrophosphates of the formula tIII)
above which can be employed individually or in combination
with other pyropho~phates in the process of the invention are:
tetraoctyl, tetranonyl, tetradecyl, tetraundecyl, tetra-
dodecyl, tetra(tridecyl), tetra(tetradecyl), tetra(pentadecyl~,tetxa(hexadecyl), tetra(heptadecyl), tetra(octadecyl), tetra-
(nonadecyl), tetra(eicosyl), tetra(heneicosyl), tetra(docosyl),
tetra~tricosyl), tetra(pentacosyl), tetra~hexacosyl), tetra-
(heptacosyl), tetra(octacosyl), tetra(nonacosyl3, tetra~tria--
contyl), tetra~pentatriacontyl), tetra(dod~cenyl~, tetra(tridecenyl),
-18-
* Trademark
~ 3~7 3698A
tetra(tetradecenyl), tetra(pentadecenyl), tetra(hexadecenyl),
tetra(heptadecenyl), tetra(octadecenyl), tetra(nonadecenyl),
tetra(eicosenyl), tetra~heneicosenyl), tetra(docosenyl),
tetra(tricosenyl~, tetra(pentacosenyl), tetra(triacontenyl),
and tetra(pentatriacosenyl)pyrophosphates.
Illustrative of the pyrophosphates of formula (IV)
above which can be employed individually or in combination
with other pyrophosphates in the process of the invention
are di~octyl), di(nonyl), di(decyl), di(undecyl), di(dodecyl),
di(tridecyl), di(tetradecyl), di(pentadecyl), di(hexadecyl),
di(heptadecyl), di(octadecyl), di(nonadecyl~, di(eicosyl), ;
di(heneicosyl), di(docosyl), di(tricosyl), di~pentacosyl),
di(hexacosyl), ditheptacosyl), di(octacosyl), di(nonacosyl),
di(triacontyl), di(pentatriacontyl), di(dodecenyl), di(tri-
decenyl), di(tetradecenyl), di(pentadecenyl), di(hexadecenyl),
di(heptadecenyl), di(octadecenyl), di(nonadecenyl), di(eicosenyl),
di(heneicosenyl), di(docosenyl), di(tricosenyl), di(pentaco-
senyl), di(triacontenyl) and ~i(pentatriacosenyl)pyrophosphates,.
The O-monoacyl derivatives of the acid phosphates (I)
and (II), which can be employed in the process of the
invention and which are shown as formulae (V) and (VI) above,
are readily prepared by procedures well-known in the art.
Illustratively, the corresponding acid phosphate (I) or (II)
in the form of its silver or other metal salt, is reacted
with the appropriate acyl halide RlCOHal where Hal represents
chlorine or bromine and Rl is as hereinbefore defined, using
the procedures described by Kosolapoff, ibid, p. 334. Illustra-
tive of the O-monoacyl derivatives of the acid phosphates (I)
and ~II) are the O-acetyl, O-propionyl, O-octanoyl, O-decanoyl,
O-dodscanoyl, O-benzoyl, O-toluoyl, O-phenacetyl derivatives
-19
3698A
:~.Z3~317
of the various acid phosphates ~I) and (II) exemplified
above.
The carbamoyl phosphates haviny the formula (VII)
which are employed in the process of -the invention are
readily prepared by reaction of the appropriate acid
phosphate (I) or (II) with the appropriate hydrocarbyl
mono- or polyisocyanate using, for example, the procedure
described by F. Cramer and M. Winter, Chem. Ber~ 92, 2761
tl959). Illustrative of such carbamoyl phosphates are the
methylcarbamoyl, ethylcarbamoyl, propylcarbamoyl, hexylcarbamoyl,
decylcarbamoyl, dodecylcarbamoyl, allylcarbamoyl, hexenyl-
carbamoyl, octenylcarbamoyl, decenylcarbamoyl, dodecenyl-
carbamoyl, phenylcarbamoyl, tolylcarbamoyl, diphenylylcarbamoyl,
benzylcarbamoyl, phenylpxopylcarbamoyl and like hydrocarbamoyl
derivatives of the monoacid phosphates (stabilized in the
form of their ammonium or alkali metal salts) as exemplified
above. The carbamoyl phosphates (VII) may contain free OH
groups due to incomplete conversion of the acid phosphates in the
reaction with the appropriate hydrocarbyl isocyanate because
of low order of reactivity of the OH groups in question with
the isocyanate. Such compounds containing said free OH groups
can be used in the process of the invention without producing
undesirable side-e~fects because of the low order of reactivity
of the OH groups with isocyanate.
The polyphosphates corresponding to the formula (X),
which are employed in the process of the invention, are
readily prepared by reaction o~ the appropriate trialkylphosphate
(RO)3PO, wherein R is as hereinberore defined, with phosphorus
pentoxide using the procedures described by Kosolapoff, i~id,
p. 341. The polyphosphates are generally complex mixtures
-20-
1~.2 3~7 3698A
whose composition is represented generically by the
formula (X), and include cyclic compounds (n = 3)
having a six-membered ring composed of alternate phosphorus
and oxygen atoms.
The polyphosphates corresponding to the formula (VIII)
and (IX), which are employed in the process of the invention,
are readily prepared by the reaction of the appropriate di
or tr~alkylphosphate and the appropriate halophosphate
(RO)2 - Hal where Hal is chlorine or bromine, using, for
example, the procedure described by Kosolapoff, ibid, p. 338.
The procedure involves elimination of alkyl halide.
In a further embodiment of the invention it is found
that the combination of polyisocyanate and phosphate release
agent employed as binder in the process of the invention can
be used in conjunction with thermosetting resin binders
hitherto employed in the art such as phenol-formaldehyde,
resorcinol-formaldehyde, melamine-formaldehyde, urea-
formaldehyde,urea-furfural and condensed furfuryl alcohol
series. Not only does the use of such a combination avoid
the problems of adhesion of the finished particle boards
to the platens of the press, which problems were previously
encountered with a blend of isocyanate and the above type of
thermosetting resin binder, but the physical properties of the
particle boards so obtaine~ are markedly impro~ed by the
use of the combination.
The following preparations and examples describe the
manner and process of making and using the invention and set
forth the best mode contemplated by the inventors of carry-
ing out the invention but are not to be construed as limiting.
-21-
~ 3~7 3698A
Preparation 1
Preparation of pyrophosphate from lauryl acid phosphate.
A mixture of 70 g. lauryl acid phosphate (a mixture of
O,O-dilauryl monoacid phosphate and O-lauryl di-acid phosphate;
Hooker Chemical Company) and 60 g. of phenyl isocyanate was
charged to a dry flask fitted with stirrer, condenser and
drying tube, the flask was immersed in an oil bath preheated
to 80C and the contents of the flask were stirred while the
temperature of the oil bath was slowly raised to 115C. Carbon
dioxide was evolved over a period of about 1 hour. When
evolution of carbon dioxide had ceased, the reaction mixtuxe was
cooled to room temperature and diluted with 100 ml. of chloro-
form. The resulting mixture was filtered and the solid so
collected (24.8 g. of N,N'-diphenylurea) was washed with
chloroform. The combined filtrate and washings were concentrated
on a rotary evaporator at a bath temperature of 50C. When
most of the solvent had been evaporated, crystals of N,N',N"-
triphenylbiuret separated and the evaporation was interrupted
to filter off this solid material (6.6 g.). The filtrate was
evaporated to dryness and subjected finally to reduced pressure
at 50C to remove excess phenyl isocyanate. The residue (70 g.)
was the desired pyrophosphate in the form of a colorless to
pale yellow li~uid. The infrared spectrum of the product
(in CHCl 3 ) did not show any bands characteristic of P-OH bonds
but had a strong band at 940 cm characteristic of P-O-P bonds.
Preparation ?
Prepara~ion of pyrophos~ate from lauryl acid phosphate.
A total of 70 g of lauryl acid phosphate (same starting
material as used in Preparation 1) was charged to a flask fitted
with stirrer, reflux condenser and gas inlet and was heated under
-22-
3698~
-~ ~.23~:1 7
nitrogen at ~S - 75C untiL moltcn. The melt: was
stirred while a slow stream of phosgene was passed
in for a total of 2.5 hours. The temperature was
maintained in the above range throughout the addition.
Evolution of gas from the reaction mixture was
vigorous in the first hour of the phosgene addition
but gradually subsided and was very slow at the end
of the period of addition of phosgene. After the
addition was complete, the mixture was purged with
nitrogen for 15 hours while maintaining the tem~
perature in the above range. At the end of this
time the pressure in the reaction flask was gradually
reduced to about 1.0 mm. of mercury to remove gaseous
hydrogen chloride and carbon dioxide. The viscous
residue so obtained solidified completely on allowing
to stand overnight. There was thus obtained 66 g.
of pyrophosphate as a solid which melts gradually
at abou~ 60C.
Preparation 3
Preparation of pyrophosphate from oleyl acid phosphate.
A mixture of 200 g. of oleyl acid phosphate
(comprised o a mi~ture of O,O-dioleyl acid phosphate
and O-monooleyl acid phosphate as supplied by Hooker
Chemical Company) was reacted with 160 g. of phenyl
isocyanate at a temperature of 85 - 90C for 5.5
hours using the procedure described in Preparation 1.
The N,N'-diphenylurea (6~ g.) was removed by ~iltration
after the reaction mixture had been diluted with 200 ml.
of chloroform. The iltrate was concentratad-on a
rotary evaporator and the excess unreacted phenyl
-23-
~ 8~7 3698A
isocyanate was removed by distillation at reduced
pressure. N,N',N"-triphenylbiuret crystallized from
the oily residue on standing at room temperature.
Removal of the crystals by filtration yielded 196 g.
of a liquid product, the infrared spectrum of which
exhibited a band at 940 cm characteristic of P-O-P
bands but showed no bands characteristic of the P-OH
band.
Preparation 4
Preparation of pyrophosphate from lauryl acid phos~hate.
A solution of 30.4 parts by weight of lauryl
acid phosphate (same starting material as in Prepar-
ation 1) in 21 parts by weight of toluene was
charged to a dry reactor previously purged with nitro-
gen. The solution was heated to 40C with agitationat which point a solution of 7.6 parts by weight
of polymethylene polyphenyl polyisocyanate [eq. wt. =
133; functionality 2.8; containing circa 50 percent
methylenebis~phenyl isocyanate)] in 5 parts by
weight of toluene was added. The resulting mixture
was stirred while a stream of phosgene was intro-
duced (ca. 0.1 parts by weight per minute) and
the temperature was slowly raised to 80C. The
temperature was maintained at this level, with
continuous introduction of phosgene until a total
of 20 parts by weight of the latter had been intro-
duced. The total time of phosgene addition was 5 hr.
50 mins. The reaction mixture was heated at the
same temperature for a further 40 minutes after
phosgene addition was complete before being heated
-24-
~ ~ 2~8L7 369BA
to 90 to 95C and purged with nitrogen for 2 hours
to remove excess phosgene. The pressure in the
reactor was then reduced until refluxing of toluene
commenced and the purging with nitrogen was continued
S for a further 2 hr. The toluene was then removed by
distillation under reduced pressure, the last traces
being removed in vacuo. The residue was cooled to
room temperature, treated with diatomaceous earth
tCelite 545) and filtered after agitating for 30 minutes.
There was thus obtained 23.7 parts by weight of a
mixture of lauryl pyrophosphate and polymethylene
polyphenyl polyisocyanate which was found to contain
6~08% w/w of phosphorus.
Preparation 5
Further preparation of pyrophosphate from lauryl
acid phosphate.
Using the procedure described in Preparation ~
but replacing the polymethylene polyphenyl polyiso-
cyanate there used by an equivalent amount (6.8 parts
by weight) of phenyl isocyanate there was obtained`a
further batch of lauryl pyrophosphate.
Example 1
A series of samples of wood particle board was
prepared using the following procedure from the compon-
ents and quantities of components tall parts by weight)shown in Table 1 below.
~ he wood chips("Turner shavings") were placed
in a rotating blender drum and the drum was rotated
while the p~rticles were sprayed with an aqueous
emulsion of the polyisocyanate, water, phosphate and
-25-
~.238:17
emulsifying agent. The emulsion was prepared by
blending the ~omponents thereof using a Turrex
mixer. The resulting emulsion was sprayed with
a paint spray gun on to the wood particles while
tumbling for 45 - 120 seconds to achieve homo-
geneity. The coated particles were formed
into a felted mat on a 12" x 12" cold-rolled steel
plate with the aid of a plywood forming frame.
After removal of the forming frame, steel bar~
having a thickness corresponding to the desired thickne~s
(1/4 n ) of the final particle board were placed
along two opposing edges of the aforesaid steel
plate and a second 12" x 12" cold-rolled steel
plate was placed on top of the mat. The complete
assembly was then placed on the lower platen of
a Dake press having a capacity of 100,000 lbs. of
~orce. Both platens of the pre~s were pxeheated
to a selected temperature shown in Table 1 below.
Pressure was then applied and the time of
molding shown in Table 1 was calculated from
the point at which the pressure exer~ed on the mat
reached 5Q0 psi. At the e~piry of the molding
time shown in Table 1 the pressure was released
and the particle board was demolded. In all
instances it was found that demolding was accom-
plished readily with no tendency o the board
to stick to the plates with which it was in contact.
This is in direct contrast to the behaviour of a
board prepared under identical conditions
but without the presence of the lauryl acid
26
* Trademark
" s
~,..
l~.Z3817 3698A
phosphate in the emulsion used as binder in preparing
th~ bo~rd.
The various samples of particle board so prepared
were then subjected to a series of physical tests
and the properties so determined are recorded in Table 1.
These properties demonstrate the excellent structural
strength properties of the boards.
TABLE 1
Board A B C D
Materials used
Wood chips 644 644 644 644
Wt. of water in chips 56 56 56 56
Polyisocyanatel 19.219.2 19.2 19.2
Water in emulsion Sl Sl 51 51
Lauryl acid phosphate 1.9 1.9 1.9 1.9
Emulsifying agent 0.10.1 0.1 0.1
* % w/w polyisocyanate 3.03.0 3.0 3.0
* % w/w water 17 17 17 17
* ~ w/w phosphate 0.30.3 0.3 0. 3
* ~ w/w emulsifier 0.016 0.016 0.016 0.016
Platen temp.F 340 340 340 340
Mold time, minutes 1.52.0 2.5 3.0
Physical Properties
Dçnsity, pcf 40 41 41 40
Modulus of rupture:
psi 37103600 43~0 4470
Modulus of elast3icity:
p~i (x 10 ) 502 472 540 5~3
4Dry internal bond: psi 102 104 112 90
sWet internal bond psi ?3 24 24 23
-27-
.2~8~
Footnotes to ~A~LE 1
~: Polymethylene polyphe~yl polyisocyanate: eq.
wt. = 133; functionality 2.8; containing
clrca 50 percent methylenebis(phenyl isocyanate1-
2: Mixture of lauryl d.iacid phosphate and dilauxylmono acid phosphate: Hooker Chemical Company.
s Ethoxylated propoxylated butanol: Witconol~
APEB: Witco Chemical Company.
4: Tests carried out in accordance with ASTM-1037-72.
5: Tests carried out in accordance with German V-100
specifications.
~ Calculated on dry weight of wood particle~.
Example 2
A series of samples of wood particle board was
prepared using the procedure described in Example 1
using ~he various components and quantities (all parts by
weight) shown in Table 2 below, The mold time shown
in the Table for samples E and F is the time for which
the mat was maintained under pressure (500 psi) after
the internal temperature of the mat (as determined by
a thermocouple inserted therein) had reached 130F.
Sample G was a control sample molded as described in
Example 1. The physical proper~ies determined for each
of the finished particle boards are also shown in Table
2 and demonstrate the excellent structural strength
of the various samples. All of the samples demolded
readily and showed no sign of adhering to the steel
plates used in their preparation.
3~
* Trademark
-2~-
.
:~.Z3~ .7 3 6 98A
T~ 2
...
Board E F G
Materials used
Wood chips 644 644 644
Wt. of water in chips 56 56 56
Polyisocyanate (same as Ex. 1) 21 42 21
Water in emulsion56 56 5S
Lauryl pyrophosphate 2.1 4.2 2.1
Emulsifying agen~ (same as Ex. 1) 0 .1 0.1 0.1
* % w/w polyisocyanate 3.3 6.6 3.3
* % w/w water 17.4 17.4 17.4
* % w/w pyrophosphate 0.33 0.65 0.33
* ~ w/w emulsifier0.016 0.016 0.016
Platen temp. F 355 355 355
Mold time, minutes2 2.
Physical Properties
Density: pcf 41 41 42
Modulus of rupture: psi 5130 5090 5320
Modulus of elasticity: psi (x 10 ) 505 513 521
Dry internal bond: psi 128 141 132
Wet internal bond: psi 32 38 31
Footnotes to TABLE 2
~: Prepared as described in Preparation 1.
. 2: Tests carried out in accordance with ASTM 1037-72.
3: Tests carried out in accordance with German V-100
qpecifications.
* Calculated on dry weight of wood particles.
Example 3
A serie~ of samples of wood particle board was prepared
_~9~
~.
. ;. .~,
~.2 3 ~1 ~ 3698A
using exactly the same reactants and proportions shown
in Example 1 and using exactly the procedure described
in that Example, save tha~ the platens of the press
were preheated to 400F and maintained thereat for
S the various molding times shown in T~ble 3 below. The
physical properties of the samples so prepared are
also recorded in Table 3 and show that these samples
all possessed excellent structural strength. None
of the samples ~howed any tendency to adhere to the
molding plates during demolding.
TABLE 3
Board H I J K L
. ... ~
Mold time, minutes 1.0 1.5 2.0 2.5 3.0
Physical Properties
Density: pcf 40 40 41 40 40
Modulus of rupture: psi 2760 3530 3150 3210 3370
Modulus of elasticity: ps~ 409 472 441 438 454
(x 10 )
Dry internal bond: psi94 102 88 107 107
Wet internal bond: psi23 24 23 25 24
Footnotes to TABLE 3
I: Tests carried out in accordance with ASTM 1037-72.
2: Tests carried out in accordance with German V-100
specifications.
Example 4
A series of samples of wood particle board was prepared
usi~g the procedure described in Example 1 but varying
the nature of the polyisocyanate and employing, in place
of the lauryl acid phosphate, the pyrophosphate derived
from oleyl acid phosphate pr~pared as described in
Preparation 3. The various components and the proportions
thPreof (all parts by weight) are shown in Table 4 below
: , -30-
. .; .~, .
~ ~.23~17 3698A
together with the physical properties determined on
the ~inished samples. The thickness of the board
samples in all cases was 3/8 inch (spacer bars
of appropriate thickness were used). None of the
samples showed any tendency to stick to the molding
plates during demolding. Th~ physical properties
of the various samples show that they all have
excellent structural strength.
- z ~ -
3698A
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3698A
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Footnotes to T~BLE 4
: Liquid prepolymer of methylenebis(phenyl isocyanate):
Eq. wt. = 181
2 : Polymethylene polyphenyl polyisocyanate containing circa
65 percent methylenebis(phenyl isocyanate): eq. wt. - 133
3 : Polymethylene polyphenyl polyisocyanate containiny circa
45 percent methylenebis(phenyl isocyanate):eq. wt. = 133.5
4 : Liquid methylenebis(phenyl isocyanate) prepared in
accordance with U. S. 3,384,653: eq. wt. = 143
5 : Polymethylene polyphenyl polyisocyanate containing circa
35 peroent methylenebis(phenyl isocyanate): eq. wt. 140
6 : Polymethylene polyphenyl polyisocyanate containing circa
35 percent methylenebis(phenyl isocyanate): eq. wt. 140
7 : Polymethylene polyphenyl polyisocyanate containing circa
70 percent methylenebis(phenyl isocyanate): eq. wt. = 133
8 : Same as Example 1
9 : Toluene diisocyanate
: Testscarried out in accordance with ASTM 1037-72
1l , Tests carried out in accordance with German V-100
specifications
Example S
This example illustrates the preparation of particle
board in accordance with the invention using a binder
composition in which no extraneous emulsiying agent is
present and the polyisocyanate was applied neat, i.e.
not in the form of an aqueous emulsion.
A series of samples of wood particle board was
prepared using the various components and ~uantities (all
parts by weight) shown in Table 5 below and using the
procedure described in Example 1 with the exception that the
wood particles were first sprayed with the stated amount
of water and thereafter were sprayed with a mixture of the
polyisocyanate and the phcsphate release agent. The
3Q physical properties determined for each of the finished
-34-
3698A
:~.Z38~
particle boards are also shown in Table 5 and
demonstrate the excellent structural strength of
the various samples. All of the samples demolded
readily and showed no sign of adhering to the steel
plates used in their preparation.
TABLE 5
~oard_ W X Y Z zZ_
Materials
Wood chips 644 644 644 644 644
1~ Wt. water in chips 565S 56 56 56
Polyisocyanate 38.638.6 38.6 38.6 38.6
(same as Ex. 1)
Water 56 56 56 56 56
Lauryl pyrophosphate 3.9 3.9 3.9 3.9 3.9
~same as Ex. 2)
* % w/w polyisocyanate 6 6 6 6 6
* % w/w water total 17.4 17.4 17.4 17.4 17.4
* % w/w pyrophosphate 0.6 0.6 0.6 0.6 0.6
Mold time (minutes) 2 2.5 3.0 2 2.5
Board thickness (inches) 3/8 3/8 3/8 1/2 1/2
Physical pro~rties
Density pcf ~2 41 42 40 41
Modulus of rupture:
psi 5320 5186 5787 4325 4B10
IModulus of elasti3ity:
psi (x 10 ) 501 510 564 377 365
lDry internal bond: psi 135 133 141 lB3 178
2Wet internal bond: psi 43 42 46 50 4
Footnotes to TABLE 5
* Calculated on dry weight of wood particles
I Testscarried out in accordance with ASTM 1037-72
2 Testscarried out in accordancP with German V-100
specifications
-35-
3698A
~3.~3~:~7
Example 6
This example illustrates the preparation of three
particle boards in accordance with the process o~ the
invention from "wafer" chips having varying dimensions
as large as 2" x 2" x 1/32" and supplied by Weldwood of
Canada, Ltd. No extraneous water or emulsifying agent
was used and the polyisocyanate and phosphate release
agent were applied neat.
A series of samples of particle board from the
wafer chips was prepared using the various components
and quantities (all parts by weight) shown in Table 6
below and using the procedure described in Example 1
with the exception that the wood wafers were sprayed
with a mixture of the polyisocyanate and the phosphate
release agent and not with an aqueous emulsion as in
Example 1 and that aluminum molding plates were used.
All of the samples demolded readily and showed no sign
of adhering to the aluminum plates used in their prepar-
ation. The excellent structural strength properties
of the resulting particle boards, as evidenced by the
high modulus of rupture shown in Table 6, compare very
favorably with the low value of this parameter (2500 psi)
determined in a board available commercially and
prepared from the same type of wafer chips using a
phenol-formaldehyde resin binder.
-36-
3698A
~.2~ 7
TABLE 6
Board AA BB CC
Wafer chips 955 955 955
Polyisocyanate 19.1 50 50
Lauryl pyrophosphate
(same as Ex. 2) 2.5 6.5 6.5
* % w/w polyisocyanate 2 5.2 5.2
* % w/w total water 4.7 4.7 4.7
* ~ w/w pyrophosphate 0.260.68 0.68
Mold time (mins.) 4.5 4 4.5
Board.thickness ~in.) l/2 l/2 1/2
Density, pcf 46 43 45
Modulus of rupture:psi 7317 7946 10,860
* Calcd. on dry weight of wood wafers
Polymethylene polyphenyl polyisocyanate: eq. wt. - 139:
functionality 3Ø Viscosity at 25C = 700 cps: contain-
ing circa 35 percent methylenebis(phenyl isocyanate).
Example 7
This example illustrates the preparation of a series
of particle boards using polyisocyanate binders in com-
bination with various commercially available phosphates
in amounts corresponding to approximately 0.7 percent
w/w phosphorus in the binder resin combination.
The various samples were prepared using the various
components and guantities (all parts by weight) shown in
Table 7 and using the procedure described in Example 1
with the exception that no emulsifying agent was employed,
and the wat~r was sprayed onto the chips first, followed
by the isocyanate mixed with the release agent. A11 of
the samples demolded readily and showed no sign of adhering
-37-
3698A
3~
to the steel plates used in their preparation. In
contrast, a control board, prepared in exactly the same
manner but omitting the use of a phosphate release agent
adhered to the steel plates used in the preparation
and could not be demolded without damage to the surface
of the board.
-38-
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Footnotes to TABLE 7
-
Alkyl acid phosphate derived from lauryl alcohol
prereacted with 3 molar proportions of ethylene oxide;
Textilana Division of ~enkel Inc., Hawthorne, CaliEornia.
2 Lauryl acid phosphate; Emery Industries Inc., Mauldin,
South Carolina.
3 Alkyl acid phosphate derived from ethoxylated lauryl
alcohol; Emery Industries Inc.
Alkyl acid phosphate derived from ethoxylated mid-chain
branched aliphatic alcohol; Emery Industries, Inc.
5 Alkyl acid phosphate derived from n-octyl alcohol;
Textilana, ibid.
' 10
6 Alkyl acid phosphate derived from ethoxylated lauryl
alcohol; Emery Industries Inc.
7 Prepared as described in Preparation 5.
* Calcd. on dry weight of wood wafers.
Example 8
A further series of particle board samples was prepared
using the same phosphate release agents and procedure
employed in Example 7 but at iower levels of concentration
in the binder resin combination. The various components
and the proportions thereof ~all parts by weight) are shown
in Table 8 below together with the physical properties
determined on certain of the samples. All the samples could
be demolded without damage to the board or signi~icant
adhesion to the mold plates. The samples prepared using
the higher concentrations of phosphate release agent slid
out from between the mold plates when demolded whereas
some of those prepared using the lower concentrations of
phosphate release agent (OO, QQ, and UU) required assistance,
e.e. tapping of the mold plates, in order to eff2ct releaseO
All the samples had a thickness of 1/2" in the final board.
-40-
3698A
æ
0 ~ O O ~ O r~ O ~
~h o ~ ~ ~h ~ rt~ rt tg ~h ~D 3 ~ ~ (D
1~-x P) rr~ rDX P~ x SDX rD x ~ - n ~ It
:~ n ~ n ~ n ~n ~ PJ O ~-
P~ o 1~- ~ ~ P~
~:~ O ~ ~ ~ ~X ~ ~- ~
3 rD ~ ~ u~ b:
tJ- ~S :q O ~ 1--r~ tD O
~ --(D
_ _ _ . . .... .. .
o ~ ~o
~ I II ~ I I o~ a~ o o
. ... . _
O 1- ~D
~ I I I ~ I I a~ a~ o o
--
o ~
oo ~ o o
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co
- - -~
I I I I i ~ D
~ l l l ~ l co co ~ o o~ t
co
o ~ ~
~ I I I I I ~ co al o o~
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o ~ ~o
~ ~ l l l l l ~ ~ o o ~
- -
o l- ~
' ' I I I I I Ul ~ 00 ~ Cl)
~I I I I I I ~o a~ o o U~
-
Q ~ ~D l
P I ~ I I I I Co ~ O O ~3
_.
o ~ I
' I ' I I I I Ul lP Co t~ C
~_ I I I I C;7 Çl~ , o o C
~ `
a~
. .. .. . _
O U~ ~9
P I I ~ I I I a~ a~ o o c~
O t~
I I 'P I I I ~ Cl~ O O
--41--
3 6 9 8A
38:~7
o C~
~D ~D r~ ~ ~(D O ~t O ~0
tn ~ ~ 0~ ~ ~ ~ ~ ~'
O ~ ~ ~ ~ C ~n
~n ~ r~ ~ ~ ~
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n r~ ~ ~ r~ m
P~ ~d ~ ~ .o ~D
t ~ O ~ ~0
. IJ. 1.. ~ P~ X ~ U~ ~h ~ O
,: 3 o ~ t~ ~ '.. ~
1~ W t
a~ ~ o
~o ~ ~7 ~ O
~9 o o _
o Z
o . . . . ~2
g ~ .
~ _. _
5~ 1'- N ~ ~9Cl~ ~Z
~- ~a O ,_ ~ æ
rt O --~ w o c~
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~ ~ æ z æ æ ~
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o
~ _
æ æ z æ
, ~ 3 ~o
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cr~ ~
\- ~, O W ~
a~ ~I o o~
z: ~ æ æ
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a~ o ~
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C~
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1-- , ~ Ul P
~1 W 0~
O O
_
æ æ z z
--42--
3698A
Example 9
This example illustrates the use of a binder
re~in combination in accordance with the invention
in association with a phenol-formaldehyde resin binder
of the prior art.
All of the samples (1/2" thickness) were prepared
using the procedure described in Example 1, with the
exceptions detailed below, and using the reactants
and proportions (all parts by weight) set forth in
Table 9. In the case of Boards YY and ZZ the phenol-
formaldehyde resin was incorporated in the emulsion
of the isocyanate whereas, in the case of Board AAA,
the chips were sprayed firstly with the indicated
amount of added water, then with the phenol-formaldehyde
resin and finally with the polyisocyanate. In the case
of control Board BBB the chips were sprayed with water
and then with phenol-formaldehyde resin. The Boards XX
and ZZ showed no significant adhesion to the mold plates
after molding whereas serious adhesion problems were
encountered in the case of Boards YY, AAA, and BBB. The
physical properties of the various boards are also shown
in Table 9, from which it will be seen that the properties
of Boards XX and ZZ, bo,th within the scope of this
invention, are clearly superior to those of Boards YY,
AAA and BBB all of which are outside the scope of the
invention.
I
-43-
-- 3698A
1~.23~7
TABLE_9
Boards XX YY ZZ AAA BBB
Materials
Wood chips 1920 19201920 1920 1920
Wt. water in chips80 80 80 80 80
Phenol-formaldehyde resin -- 96 96 96 192
Polyisocyanate (same as
E~. 1) 96 48 48 48 --
Added w~ter 208160 160160 112
2 Emulsifying agent ~.42.4 2.4 -- --
10 3 Lauryl pyrophosphate9.~ -~4.8 -- __
* % w/w resin 5 5 5 5 5
* % w/w water 15 15 15 15 15
* ~ w/w phosphate 0.5 --0.25 -- --
Platen temp. F350350 350350350
Mold time (minutes)5.S5.5 5.55.5 5.5
Physical Properties
Density pcf 41~742.8 44.644.541.4
4 Modulus of Rupture:psi3650 300033203250 2770
20 4 Modulus of elasticity ps 3 310 300 355 319 301
4 Dry internal bond:psi 170 158152 168 100
5 Wet internal bond:psi 78 64 61 50 22
1 PB-65: Borden; aqueous suspension, 50% solids.
2 Aqueous solution: sodium salt of styrene-maleic anhydride
copolymer; 30% solids: Monsanto.
3 Prepared as described in Preparation 4.
4 Tests carried out in accordance with ASTM-1037-7~.
5 Test carried out in accordance with German V-100 specifications.
* Calcd. on dry weight of wood particles.
. . .
L7
SUPPLEMENTARY DISCLOSURE
In addition to the phosphate species set out in
the original disclosure, certain further phosphate species have
now been found to be useful in particle board binders.
Hence binders containing these phosphates and the process of
making such binders constitute further embodiments of the
invention.
Thus, the present invention provides a process
for the preparation of particle board wherein particles of
organic material capable of being compacted are contacted with
a polyisocyanate composition and the treated particles are
subsequently formed into boards by the application of heat and
pressure, the improvement comprising contacting said particles,
in addition to the treatment with said polyisocyanate
composition, with from about 0.1 to about 20 parts, per
100 parts by weight of said polyisocyanate, of a phosphate
selected from the class consisting of
(a) acid phosphates of the formulae
- O O
RO P - OH and (RO)2~ OH
2n OH
~I) (II)
and the ammonium, alkali metal and alkaline
earth metal salts thereof;
(b) pyrophosphates represented by those derived
from the acid phosphates (I) and (II) and
mixtures of (I) and (II);
(c) The O-monoacyl derivatives of the acid
phosphates (I~ and (II~ havina the formulae
O O.
3P RO P OCORl and ~RO)2P OCOR~ ;
OH
(~) (VI)
(d) carbamoyl phosphates having the formula
, . .
SD4 5
3698A
3~ 7
I
R2 NHCO--O p ( OR)
OH
(VII)
and the ammonium, alkali metal and alkaline
earth metal salts of the compounds of formula
(VII);
(e) branched polyphosphates of the formulae
O O O O O
RO -P - O -~(OR) 2 and (RO~ 2~ - O ~- o - ~(OR)2
1 r (OR)2 (VIII) ¦ (IX);
~ o -~(OR)2
(f) polyphosphates corresponding to the general formula
. ~
[ROP - ]n (X~
including the cyclometaphosphates (n = 3); and
(g) mixtures of two or more of said compounds;
wherein, in the various formulae shown above, each R
is independently selected from the class consisting of
alkyl having from 3 to 35 carbon atoms, inclusive, alkenyl
having from 8 to 35 carbon atoms, inclusive, aryl, and
R'- (O-CH-lH~
wherein R' is alkyl having from L to 35 carbon atoms,
inclusive, and aryl, one of A and B represents hydrogen and the
other is selected from the class consisting of hydrogen
and methyl, and n is a number having an average value from
- SD46 -
L7
1 to 25; provided that when one of the Rs in ~ormula (II) is
alkyl having from 3 to 35 carbon atoms, inclusive, th~ other R
can be selected from methyl and ethyl; Rl is hyclrocarbyl from
1 to 12 carbon atoms, inclusive; R2 is selected from the class
consisting of hydrocarbyl from 1 to 12 carbon atoms and
hydrocarbylOsubstituted by at least one additional
~r
- NHCOO - P(OR)2 group wAerein R has the signi~icance defined
above; and n is an integer.
The invention also comprises novel compositions
comprising organic polyisocyanates having incorporated
therein one or more of the aforementioned compounds.
The following preparation and examples describe
the manner and process of making and using the new phosphate
compounds and binder compositions. The preparation and
examples are intended only to illustrate the invention
~ithout limiting the scope thereof.
Preparation 6
A series of acid phosphates (mixtures o mono- and di-acid
phosphates) was prepared by reaction of the corresponding alcohol
with phosphorus pentoxide using the following standard procedure
which is illustrated for the preparation of the mixture of the
corresponding ~ono- and di-(hexyloxyethyleneoxyethyl)phosphate
by reaction of hexyl carbitol (hexyl ether of diethylene glycol)
with phosphorus pentoxide.
A total of 9.97 g. (0.07 mole) of phosphorus pentoxide
was charged, under nitrogen and in the absence of ~oisture, to
50 g. of freshly distilled methylene chloride. To the resulting
3C
- SD47 -
I ~fE3
~ ~ 3698AA
3~7
mixture was added, with rapid stirring, a total of 41.4 g.
(0.218 mole) oE hexyl carbitol at such a rate as to
maintain a steady rate of reflux of solvent. When the
addition was complete, the solvent was permitted to distil
slowly from the reaction mixture while the pot temperature
was not permitted to rise above about 80C. The last traces
of solvent were removed in vacuo on a rotary film evaporator
for 15-30 minutes at 85 - 90C. There was thus obtained a
mixture of the mono- and di-(hexyloxyethyleneoxyethyl) acid
phosphates.
Using the above procedure but replacin~ the hexyl
carbitol there used by an equivalent amount of the ollowing
alcohols:-
propyloxypropanol
butyloxypropanol
phenoxypropanvl
phenoxyethanol
nonylphenoxyethanol
butyl carhitol
tridecyl~henoxyethyleneoxYethanol[cl3H2 7 ~0 ( CH2)20-(CH2)2 OH]
butyl ether o~ tri(ethylene glycol)~C4HgO(CH2)20(CH2)20(CH2)20H]
tridecyl ether of nona(ethylene glycol)[C~3H2~0(CH2C~20)9H]
methyl ether of dodeca(ethylene glycol)~CH30(CH2CH20)12H]
dodecyl ether of dodeca(ethylene glycol)[C~2H2sO(CH2CH20)l2H]
methyl ether of heptadeca(ethylene glycol)~CH30(CH2CH20)l~H]
phenol
mixture of methanol and dodecanol
n-propanol
n-butanol
heptanol and tridecyl alcohol;
- SD48 -
~,
.. ~
~.Z3~
there were obtained the corresponding mixtures of the mono- and
di-acid phosphates.
All the above acid phosphates were employed as release agents
in combination with a polyisocyanate binder in the preparation of
particle boards in accordance with the invention.
Example 10
A series of samples of wood particle board was prepared
using a combination of a polymethylene polyphenyl polyiso-
cyanate and an acid phosphate as the binder. The polyisocyanate
used in all cases was a polymethylene polyphenyl polyisocyanate
containing approximately 48 percent by weight of methylenebis-
(phenyl isocyanate) and having an isocyanate equivalent of
134.5 and a viscosity at 25C of 173 cps. A different acid
phosphate was used in each instance but all the acid phosphates
were mixtures of di-acid phosphates of formula RO-~(OH) 2 and
mono-acid phosphates ~RO) 2 (OH) where R had the value shown in
Table 10 below, said mixture of acid phosphates having been
prepared as described in Preparation 6 above unless otherwise
stated.
The method of preparation of the particle board sample
in all instances was as follows:-
A batch of ~00 a. of ~ouglas fir wood chips W25 sprayedwith 112 g. of the polyisocyanate using the procedure and
apparatus described in E~ample 1. When the spraying and tumbling
with polyisocyanate was complete, the treated chips were then
spraved using the same procedure and apparatus with an amount of
the mixture of acid phosphates such that the total amount o~
phosphorus present in the combination of acid phosphate and
pol isocyanate ~;as apprcximately 1 percent by weight. The e~act
amount of the acid phosphate used in each instance is recorded
in T3ble 10 belo~ he mi~ re of acid phos-ha-es W25 dil~_^d
- SD'9 -
~.23~7
with 40 - 50 g. of Freon Rll (trichlorofluoromethane) or water
(diluent indicated in each case in Table lO) to facilitate
spraying. An aliquot ~2156 ~.) of the treated chips was then
utilized to prepare a particle board having a thickness of 3/8"
using the procedure described in Example l but using cold-rolled
steel plates having a dimension of 24" x 36" and a forming
frame with inside dimensions of 18.5" x 3~". A sheet of
aluminum foil was inserted ~etween each steel plate and
the abutting surface of the particle board mat. The platen
temperature was 350~F, and the press time was 2.5 minutes at
about 500 psi minimum, in all cases. After the particle board,
with aluminum sheets in contact therewith, was removed from
- the platens of the press, the relative ease with which the
aluminum foil separated from the particle board was rated as
"excellent" (no resistance to removal), "good" (no resistancb
to peeling of foil) or "fair" (some resistance bu~ could be
peeled off without tearing or other damage to the foil). It
~as apparent that all the acid phosphates used ga~e significant
release properties. The data relating to ~he sam~les is sh~wr
in Table 10.
- ~r50 -
* Trademark
TABLE 10
% w/w acid Diluent
R in acid ~ w/w P in phosph~te for Ease of
phosphate binderl in binderl phosphate release
___ . _
C3H 7 O-C 3H6- 1.18.6 FreonGood
C4HgO~C~H6~ 1.08.7 FreonExcellent
C6HsO~C3H6~ 1.09.7 FreonFair
2C4HgO~CH2CH2~ 1.012.4 WaterGood
nonylphenyl-O-CH2CH2- 914.4 Freon Excellent
C4Hg-(OCH2CH2t~r 1.010.2 FreonExcellent
C6Hi~OCH2CH2~ 1.011.9 FreonExcellent
tridecylphenyl-(OCH2CH2t 20 . 8 16.8 Freon Excellent
C4H9-(oc~2cH23-3 1 O12 .1 FreonExcellent
*3di(nonyl)phenyl-(OCH2CH~t~0.8 28~9 Freon Excellent
* Cl3H27(oCH2CH239 0.825.1 FreonExcellent
- 15 4nonylphenyl-(OCH2CH~t~ 0.830.1 FreonExcellent
* CH3-(OCH2CH2~ 1.224.3 FreonExcellent
* Cl2H2s-(OCH2CH2)12 0.829.4 FreonExcellent
* CH3-(OCH2CH2~ 17 1.230.0 I FreonExcellent
C,2H25(0C}12CH2-t~ 0~742.2 FreonFair
C4Hg- 1.06.2 ~ FreonFair
C6H5- 1.5j 10 ' FreonFair
Mixture of CH3-and Cl2l~2s0 9 , 7.1, Freon Excellent
nonylphenyl 0.6! 7.4 I Freonxcellent
Footnotes to TABLE 10:
1: binder = polyisocyanate + acid phosphate
2: As diethylamine salt: Virco Pet 30~ Mobil Corporation
3- Tryfac 5555: Emery Industries
4: Tryfac 5556: Emery Industries
*: Each of these acid phosphates in admixture with the isocyanate
form~d a good emulsion when shaken with water.
- SD 51
* Trademark
.;~. , .
` 369aAA
Example lL
Using the procedure described in Example 10, but
replacing the mixture of acid phosphates by bis-2-ethylhexyl-
pyrophosphoric acid (Mobil Corporation) and by dibut~lpyrophosphoric
acid (~obil Corporation) in amounts representing 12~ by weight
based on total weight of pyrophosphoric acid and polyisocyanate
there were obtained particle boards with ease of release rated
as "excellent" for the former and "fair" for the latter.
Example 12
A further series of wood particle boards was prepared using
exactly the same procedure as that described in E~ample 10 wlth
the sole exception that the mixture of acid phosphates was
blended with the polyisocyanate and the blend was diluted with
40 - 50 g. of Freon Rll before being sprayed on to the wood
chips. The polyisocyanate employed throughout the series was the
same as that employed in Example 10. A different acid phosphate
was used in each instance but all the acid phosphates were
mixtures of di-acid phosphates of formula RO-~(OH) 2 and
mono-acid phosphates (RO)2~(OH) where R had the value shown in
Table 11 below, said mixture of acid phosphates having been
prepared as described in Preparation 6 above unless otherwise
stated. The ease of release of the particle boards from the
aluminum foil were rated on the basis set forth in Example 10.
The results are recorded in Table 11.
- SD 52 -
~= . . .
3~ 7
TABLE ll
% w/w acid
R in acid % w/w P inphosphate Ease of
phosphate binderlin binderl release
*2C12H2s(OCH2CH2t~ 0.6 9.7 Excellent
53Cl2H2s(OCH2CH2~ 3O. 6 10.6 Excellent
4CI2H25(OCH2CH2~s 0.6 13.6 Excellent
*5CI3H27(OCH~CH2~6 0.6 14.3 Excellent
C3H7 l.0 5.0 Fair
C4Hg 1.7 10.0 Excellent
lOC7HIs 1.3 lO.0 Excellent
CBH~7 0.5 4.6 Excellent
62-ethylhexyl- 1.2 lO Good
7tridecyl 0.8 10 Excellent
Footnotes to TABLE 11
. _ _
5 *: Each of these acid phosphates in admixture with the
isocyanate formed an emulsion on shaking with water.
1: binder~= polyisocyanate + acid phosphate
2: Fosterge A25?3: Textilana
3: Tryfac 325A: Emery Industries
4: Tryfac 525A: Emery Industries
5: Tryfac 610~: Emery Industries
6: Mobil Corporation
7: Mobil Corporation
As noted in the above Example and in Example 10, a number
of the acid phosphates there used possess "self-emulsifying"
properties, i.e. form emulsions when shaken or otherwise agitated
with water in the absence of an additional surfactant. This
rinding is particularly advantageous where the poiyisocyanate
binder containing the acid phosphate release agent is employed
in the form of an aqueous emulsion, since, in the case of ~he
- SD 53 -
. 3698AA
~1~.2~B~7
above acid phosphates there is no need to employ an additional
emulsifying agent -- the acid phosphate serves both as release
agent and emulsifying agent. It has been found that such
"self-emulsifying" properties are found in the case of those
- 5 acid phosphates of the formula (I) and (II) wherein R represents
R'- (O-fH-~H~ wherein R', A and B have the significance
A
hereinbefore defined and m has an average value from 3 to 30.
- SD 54 -
