Note: Descriptions are shown in the official language in which they were submitted.
DISCLOSURE:
This invention relates to the 2roduction o~ thermosetting
phenol formaldehyde resins.
A great deal of prior worlc has been done on the phenol-
formaldehyde resins system. These :resins are valuable for use
in preparing various thermosetting materials. It is also commonly
known to react phenol and formaldehyde in the presence of another
monomer to yield a condensation product.
In the present invention, the phenol is methylolated in
the absence of other monomers using calcium oxide (calcia), or
calcium hydroxide as a catalyst. The use of calcium type catalysts
is known in the art. The known prior art does not disclose the
present invention, nor are they capable of making full water-
soluble products having the desirable characteristics achieved by
the practice of the present invention.
In the commercial manufacture of phenol formaldehyde
resins, it is economically desirable to achieve as high a ratio
of formaldehyde to phenol as is practical, in order to permit the
subsequent combination with higher amounts of low cost monomers.
Such high mole ratio of formaldehyde to phenol in binder resins
also appears to increase the resinification efficiency, and leads
to a better bond with any substrate to which the material is to
be applied, when combined with additional monomers. In particular
the presence of unsubstituted (free) phenol in the product is found
to be detrimental to the resin. The phenol will have a tendency
to distill off in the curing process and this constitutes a potent
air pollutant.
Structurally, the upper limit for formaldehyde addition
is about 3 moles of formaldehyde per mole of phenol. In accordance
with the present invention, a high ratio of formaldehyde is pro-
; vided together with a very high ratio of calcium catalyst. In the
calcia-cataLyzed system, the high catalyst percentage directs the
- 1 - : ' '
~;
reaction toward~ a minimum of unreacted phenol, while slmulta-
neously a minimum of water insoluble ph0nyls are formed. The
present invention provides a means of ~orming such binders in an
essentially one-step process, by the use of a catalyst which
achieves the reaction more easily.
The present invention provides a product which has a low
content of water insoluble materials, free phenol, monomethylol,
and the like, and avoids the necessity for extracting such mat-
erials. The prior art requires various types of extraction steps
for the obtaining of a suitable resin.
The present invention therefore provides a method of
making a calcium catalyzed thermosetting resin comprising the
step of methylolating a phenol with formaldehyde, under alkaline
conditions, in the presence of calcium hydroxide, and water as a
solvent. The methylolation reaction is terminated by cooling
while the condensation reaction product is still water soluble.
The formaldehyde is introduced in an amount of 2.8 to 4.5 moles per
mole of phenol. The calcium hydroxide is present in an amount of
3 to 5.5% calcium based on the weight of phenol. The pH during
2Q the cooking reactions will be moderately alkaline in the range of
8 to 9.5t and ~iLl preferably be in the range of 8.3 to 9.5, and
most preferably 8.5 to 9.5.
The formaldehyde may preferably be introduced in an
amount of 2.8 to 4.5 moles per mole of phenol, preferably 3 to 4.5;
more pre~erably 3.5 to 4; and most preferably 3.5; 3.6; 3.7 or 3.8 --
moles per mole of phenol. The phenol most preferably should be
U. S. P. grade. The calcium hydroxide may preferably be present
in an amount of 4.5 to 5% calcium, based on the weight of phenol.
The reaction may be carried out at any suitable tem-
30 perature, preferably no higher than about 155F., and preferablyfor a period of 3 to 10 hours.
- 2 -
~.
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,.. , - .... .: :
,
.
The minimum ~e~ction tlme is not sharpl~ de~ined and is
contingent upon the effectivenass of the heat exchange mechanism.
It will normally be at least three hours in conventional batch
apparatus equipped with a high speed stirrer. However, it is
possible to achieve the desired reaction in a lower time, provided
that the exothermic reactton does not over heat the material.
For example, it should be possible to operate at a reaction time
of 2 and 1/2 or 2 hours, or even lower, in a continuous reaction
system or in a very small reactor, where the heat ma~ be dissipated
iO quickly. The same effect might be achieved if very high shear
apparatus is employed.
The reaction temperature should preferably be maintained
no higher than 125F. for the first hour of reaction time. The
reaction may be carried out in batches or may preferably be carried
out in a continuous manner in apparatus suitable for the purpose.
If the reaction is carried out at atmospheric pxessure, the tem-
perature will preferably be controlled by the use of heating and ~
cooling coils. The reaction may also be carried out at sub-atmos- 1~ -
pheric pressure with a reflux condenser being employed to maintain
2Q the reagent concentrations. After carrying out the process the
product may, if desired, be brought to a neutral or mildly alkaline
pH of 7 to 7.6 by addition of an acid. Partial or complete neu-
tralization of the resin tends to increase the gel time of the
resin among other things. For example, the gel time by a standard
method in one case went from about 300 seconds to 450 seconds and
then to 600 seconds, in adding acid and bringing the pH from 8.6
through 8.2 to 7.6. Among acids which have been found suitable ;
are the following: sulfamic, phosphoric, sulfuric, acetic, maleic,
and carbonic acids, and their ammonium salts. Alternatively, the
3a resin may be stored at room temperature or under refrigeration in
its alkaline condition and neutralized just before use, if at all.
: ,
- 3 -
.~:
:............. . . .
:, '~' ' ' ' . '
The condensatiQn reacti~n product will normally be ~ur-
ther combined with a monomer or an amine type resin or amine type
copolymer resin. Accordingly, the above method may ~urther com-
prise combining the condensation product with up to 82~ of a mono-
mer or an amine type resin or amine type copolymer resin based on
the combined solids to produce a thermosetting, low phenolic, res-
inous bonding material.
The present invention further provides a water disper-
sable soluble or water soluble calcium catalyzed phenol-formalde-
lQ hyde condensation resin product, characterized as follows:
(i) a ratio of 2.8 to 4.5 moles of formaldehyde per
mole of phenol,
(ii) 3 to 5.5% of calcium based on the weight of phenol,
(iii)- not over about 2% unreacted phenol by weight,
(iv) between 3 to 16% unreacted formaldehyde, by
weight,
(v) between 2.3 to 2.7 methylol groups per phenol
molecule,
(vi) low content of water-insoluble higher phenyls,
preferably not exceeding 1.5% of total as determined
by gas chromato~raphy on the silylized resin,
(vii) low content of monomethylolphenol, preferably
not exceeding a maximum content of 1.5%, based upon
the weight of the liquid resin.
__ The unreacted (free) phenol will be normally present
between 0.10% and 2.0% by weight, which is considered to be among
acceptably low levels.
The resins produced by the present invention may be
practically clear. Following neutralization any insoluble neu-
trazliation products are of micron to sub-mircon particle size and
are essentially non-settling.
. .. .
. , .: ~ .
..
The resin conflguration contributes to the outstanding
chemical stability at room termperature of these resins. This
stability which has been observed before or after neutralization
of the catalyst by conventional means, is remarkable in view of
the relative instability of the prlor art products, and is econo-
mically attractive. Because of it, the resins produced following
this invention ~lay be stored or shipped at ambient temperatures
or lower, with or w-ithout having been neutralized.
The choice of calcia in high concentration as catalyst
la further contributes to more economical and efficient production of
a higher quality material than is achieved with the conventional
catalysts such as alkali metal hydroxides, barium hydrates, etc. ~ ;
The material costs are rather considerably lower since relatively
inexpensive calcium oxide (burnt lime) may be employed. The cal-
cium oxide or calcium hydrate used in carrying out the present
development work came from various sources, as reflected in the ';
accompanying examples. In addition to the lower raw material costs
for the catalys~, the resinification efficiency is higher during
the reaction, i.e. a higher proportion of the phenol and formal-
2Q dehyde is converted into useful resin solids.
Further technical and economical advantages arise from ~;
the finding that resins produced by the present invention, when
combined in aqueous solution with urea and the conventional binder
- - ingredients, show better bonding characteristics at 60% advanced
calcium catalyzed phenolic resin combined with 40% urea, than 65- -
to 70~ conventional sodium, barium or magnesium catalyzed phenolic
resin combined with 35 to 30% urea.
For the same reasons, the resin may be used satisfac-
torily in binders containing 70% or more of conventional alkylated
amine copolymer resin of the type disclosed in U. S. Patent No.
3,624,246, issued November 30, 1971 entitled "Alkylated Amine
Copolymers" of Deuzeman et al, in U. S. Patent No. 3,487,048
_ 5 _
: :. .
7~
issued December 30, 196~ ~f Deuzeman enti~led "~eh~lated ~el~ine-
Formaldehyde Condensate" and in U. S. Patent No. 3,432,453 issued
March 11, 1969 of Gladney and Deuzeman.
The use of the present calcia catalyzed system offers
other practical technical and economical advantages over conven-
tional systems as follow from the materials used and the composition
of the condensation reaction products.
Referring to the commonly accepted A-B-C stages in the
cure of a phenolic resin the high percentage of calcium catalyst
1~ results in a phenolic resin with a long A ~B stage, good flow
characteristics in the B stage, and a short curing time from B to
C stage. Thus, the present resins and binders produced therefrom
; do not tend to pre-cure at the point of application (which adversely
affects operation and product~ but do cure at least as rapidly in
the curing ovens as resins used heretofore.
l As is known in the art, conventional barium or soda
-~ catalyzed phenol-formaldehyde resins must be neutralized upon ter-
minating the condensation reaction ("resin coo.~") otherwise they
will continue to react. In contrast, the calcia catalyzed resins
2Q have been found to be very stable. In some cases, material has
been stored in its non-neutralizing state at up to 70 F for several -
months without deterioration. Normally, the resin cook will be
"neutralized" after reaction either lmmediately, or at the time of
using the resin, however, for some end uses this may not be
necessary at all. There are several known ways of neutralizing
when required.
In the case of soda (Na20) or potassia (K20) catalyzed
j resins neutralization with acids such as hydrochloric acid, sul-
furic acid or carbonic acid, soluble salts are formed in the
aqueous resol solution, in quantities potentially objectionable
for the use of such resins in certain end uses, for example the
bonding of glass fibres. Upon the neutralization of barium hy-
- 6 -
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., ~
;,~ . " ' :
P~
droxide catal~st ~ith sulfu~c ~c~d, a precipitate hay~ng a high
specific gravity of 4.5 is ~ormed, and it must be ultra-fine in
order to avold settling during storage and other operations. Sim-
ilarly, barium carbonate has a spec:ific gravity of 4.3, whereas
calcium sulfate and calcium carbonate have a specific gravity of
2.9 and 2.8 respectively. These ca:lcium salts appear to resist
settling in particle sizes as large as 1 to 2 microns and it does
not appear necessary to obtain colloidal particle size (0.1 micron).
Using catalyzation with caustic soda or barium hydrate
in conventional concentrations, the resulting resins cannot be
cooked long enough to react all free phenol without simultaneously
forming water-insoluble phenyls and other reaction products, which
tend to agglomerate upon dilution with water and other binder in-
gredients to form objectionable gummy masses in the binder circu-
lation system, filters, spray nozzles, and the like.
One of the requirements for binder resins is a very
high degree of water miscibility, or dilutabillty. It is common
to require miscibility of the resin with no less than 500% of water
but preferably with 2000% or more ("infinite dilutability") without ~;
2Q clouding~ By the use of the process of the present invention, a
resin may be obtained which contains a minimum of these objection-
able water insoluble reaction products.
If a resin has an excessi~e amount of monomethylolphenol
a binder formed therefrom may be found objectionable. The mono-
; methylolphenol being relatively volatile will on application be
entrained in the effluent gas stream and resist removal therefrom.
The monomethylolphenol should be maintained at a level low enough
to minimize this effect. A suitable range of monomethylolphenol
' is from 1.5~ down to 0.075~ of the weight of the liquid resin.
Similarly, the higher phenyls are objectionable in high
concentrations because they are poorly soluble in water and will
precipitate out on dilution of the resin suspension or solution
....... . .
in forming a binder. Accordingly, the concentration of the
higher phenyls should be kept below the level at which such
objectionable precipitates will form on dilution. This level will
also be different for each system and may be ascertained where re-
quired. The higher phenyls do not exceed 1.5% of the total peak
height of the silylized resin when run through a gas chromato-
graph.
The phenol/formaldehyde resin product was examined using
gas chromatography by silylization as follows. To a small sample
of resin is added a silylizing agent, in this case'N,O-Bis (Tri
methylsilyl)-Trifluoroacetamide (BSTFA) in slight excess of two-
fold and the two were allowed to react.
The BSTFA donated a Si(CH3)3 group which replaces labile
H2 and forms trimethylsilyl derivatives, which are stable and may
be chromatographed within the operating temperature limit of the
column, with excellent separation, up to the di-phenyl with 4
methylol substitutions.
The resins produced in accordance with the present in-
vention may be used in a wide variety of aqueous binder formula-,
tions as previously stated.
In the present examples the cone efficiency test was
carried out following the method and apparatus for evaluating
resin or binder systems as described by A. Simison in U. S. Patent
2,653,473. It serves to determine the percentage o resinous pro-
ducts retained during application to mineral fibres, in relation
to those lost by volatilization under conditions closely simula-
ting those experienced in manufacture.
The use of such resin solutions which are further mixed
with a monomer before combining with other materials to form a
binder formulation is preferable to the alternative of preparing
a so-called copolymer resin, in which the other non-phenolic mono-
mer, such as urea, is added to the mixture of phenol and formal-
.,.. , ~ ...
7~
dehyde durlng the condensation there~f. A successful copolyme~resin cook cylce is not only dependent on the ratio of formalde-
hyde to other monomers and on the type and concentration of cata-
lyst used but to a great degree its success depends on the stabil-
ity Qf the reaction products formed during the cook, which products
are all competing for the a~aila~le free formaldehyde in the cook.
Therefore, temperatures and sequences of additions of monomers
are critical and so is the free ~ormaldehyde level in the cook at
the points of various additions. It is sometimes also necessary
lQ to vary the temperature and pH during the cook. Storage life of
the resulting copolymer resins are usually short ~ven when cooked
and stored under optimum conditions if high water tolerances have
to be met.
Many of these difficulties are overcome by the present
invention which involves reacting phenol and formaldehyde separ- ;
ately under more easily controlled conditions. In accordance with
the present invention a phenol formaldehyde resin is cooked to ;~
optimum properties and held in storage until needed. Another
resin such as a urea resin or urea copolymer may also be cooked to
2Q optimum properties and similarly stored. The phenol formaldehyde
resin may be combined with a monomer such as urea, and any addi-
tional resins such as amine resin, especially urea resin, before
the application of the binder to a substrate. By this means, each
resin may be produced, tested and stored at its optimum properties
and no interferences or competition occurs for the different types
of monomers with the formaldehyde during the cook.
I Among the monomers which are considexed suitable for
j addition to the phenol formaldehyde resin in forming a binder are
amines such as urea, dicyandiamide, ketones such as acetone,
3Q alcohols, such as methanol and glycols, and the like.
In carrying out the resin condensation reaction, a
reasonable amount of water should be present. If -too little
_ g _
... .
water is present, heat ey~lution is excessive, and the selectivit~
of the substitution reaction suf~ers. Too much water will slow the
reaction time down and may also result in slower-setting resins.
However, the amount of water present is otherwise not critical.
The temperatures of the reaction are normally not raised
above 155F. as hlgher temperature encourages the excessive co-
condensation and the formation of insoluble products. This tem-
perature is preferably to be reached from a charge temperatures of
70 F. or below in either a linear increase over 60 minutes or in
1~ a stepwise increase whereby a first hold temperature no higher
than 125F. is maintained for 60 minutes approximately. The con-
densation reaction is preferably arrested by cooling to 100F. or
below at a predetermined free formaldehyde content, which may
range from 3 to 16% by weight of the total charge, before any
planned neutralization of the catalyst is effected.
The neutralization of the catalyst is preferably conduc-
ted in such a fashion that a micron or sub-micron size precipitate
is formed which is essentially non-settling in the resol solutions.
The following examples are intended to exemplify the
2Q principles underlying the present invention and are not intended
to be limiting in their scope. The unmodified resin produced in
Examples 1 to 7 was sampled~ and characteristics of the samples
T~ere tested. The percentage of organic solids was determined by
- heating in a drying oven. The gel time at 266F was determined in
a steam heated brass cup. The free phenol was determined by gas
. ,.
chromatography. The resins produced in these Examples were modi-
fied in various ways and produced superior aqueous binders for
glass fiber.
.
EXAMPLE 1
3Q Laboratory preparation of a calcia catalyzed resin of a
charge ratio ~starting ratio) of 1 mol phenol to 2.8 formaldehyde.
` Charge Ratio: phenol: formaldehyde ~r 1 2 ~ 8
.
, - lo ~
~A
. . . . .
~ . ` , . .
Ingredients:
formaldehyde ~ aqueous - 44% solution 1995 gms
phenol - USP 98~ 1005 gms
calcium oxide ~ Ashgrove Springfield sn ~ 7 gms
high calcium pebble quickline ~3.5% Ca based
CaO 96.3% - ground to (-10) on weight of
mesA on U. S. standard scale phenol~
Procedure:
The formaldehyde was placed in a 3 liter glass reactor. ;~
The agitator was started~ phenol was added, and then calcium oxide
la was added. The temperature was allowed to rise to 125F. in a
period of about 1 hour. The temperature was held at 125F. for
30 minutes. The temperature was increased to 150 F. in 30 minutes.
The temperature was held at 150F. until the free formaldehyde was
4.5% and then cooled to 75F. The pH at the end of reaction was
8.70. `'
The resin was neutralized with CO2-to a pH of 7.3.
Results:
Organic solids: 48.44
Gel time at 266F. 528 seconds
2~ Free phenol: 1.8
EXA*IPLE 2 '~
Production of a calcia catalyzed resin of the starting '`
- ratio 1 mol phenol to 2.8 mol formaldehyde, suitable for use in
binders particularly, in varying combinations with urea.
Charge Ratio: 1:2.8
' Batch'Size: 2000 gals.
Ingredients:
formaldehyde - aqueous - 44% solution 1375 imp. gals. '
phenol - USP 98~ 743 imp. gals.
3a calcium oxide - Beachville rotary
crushed high calcium quick-
lime CaO 92~ 3)mesh
on U. S. standard scale 406 lbs.
. , .
~' ' '
Procedure:
The 3000 gals. reactor was loaded with formaldehyde and
phenol. The agitator was started. The catalyst (calcium oxide)
was poured in over a period of 15 minutes. When all the catalyst
was loaded, the temperature was allowed to rise 125F. in 1 hour.
The temperature was held at 125 F. for 1 hour. The temperature
was increased to 150F. over a period of 25 minutes. The temper- ~'
ature was held at 150 F. for about 1-1/4 hours to a free formal
dehyde of 4-1/2%. The mixture was cooled to 80F. The pH at the
end of reaction was 8.40.
The resin was neutralized with CO2 to a pH of 7.23.
Results:
Qrganic solids: 48.66% Cone efficiency: 73%
Gel time at 266 F.: 640 seconds
Free phenol: 2.06%
''EXAMPLE`'3
Charge Ratio:~ 1:3.1 ~ '
' I'ngred'ients:
formaldehyde - aqueous - 44%2030 gms
phenol - USP 98% 920 gms.
calcium oxide - Beachville rotary
crushed high calcium quick-
lime-CaO 93.5% -(-3) mesh 53.9 gms (4% Ca
on U. S. standard scale based on phenol)
Proced'ure !
, Formaldehyde was poured into the glass reactor, and the
agitator was started. The phenol was added, followed by the cal-
cium oxide. The temperature was raised to 120F. in a period of
about 30 minutes. The temperature was held at 120~F. for a period
of 3 hours. The temperature was raised to 140F. in 48 minutes.
3Q The temperature was held at 140F. for 43 minutes. The tempera-
ture was then raised to 150F. The mixture was cooked at this
temperature until a free formaldehyde of 5.5%. Then it was
~'
;
:,:, '' -, . '
cooled to 75F. The pH a-t the end of reaction was 7.9
The resin was neutralized with CO2 to a pH of 7~2
Results~
Organic solids: 45.61~ Cone efficiency: 78.4%
Gel time at 266F: 509 seconds
I Free phenol: 0~82%
j EXAMPLE 4
Charge Ratio: phenol:formaldehyde 1:3.5
Ingredients:
lQ formaldehyde - aqueous - 44~ solution 2139.3 gms
phenol - USP 98% 860.7 gms
calcium oxide - Ashgrove Springf~eid
high calcium pebble quicklime
- CaO 96.3% - ground to (-10) 49.06 gms (4% Ca
mesh on U. S. standardbased on phenol)
Procedure:
.
The formaldehyde was poured into the glass reactor. The
I agitator was started. Phenol was added, followed by calcium oxide.
The temperature was allowed to rise to 100F. The mixture was
- held at that temperature for 45 minutes. The temperature was -¦
2Q increased to 110F, in 30 minutes period, and held at that tem-
perature for 1 hour and 30 minutes. The temperature was raised
to 120F. in 30 minutes, and held for 1 hour. The temperature
: . ~
was raised to 130F in 30 minutes, and held for 1 hour. The tem-
perature was raised to 150F. and held at that temperature till a
free formaldehyde of 8.60%. The mixture was cooled to 75F. The
pH at the end of reaction was 8.3
The resin was neutralized with CO2 to a pH of about 7.2 ~;
Results:
Organic solids: 42.8~ Cone efficiency: 83.4%
3Q Gel time at 266 F.: 503 seconds
, .
Free phenol: 0~38~
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.. .. . ..
.. .. . . .
~XAMPLE 5:
Production of a calcia catalyzed resin of the starting
ratio 1 mol phenol to 3.7 mol formaldehyde, suitable for use in
binders particularly, ln varying combinations with urea.
Batch size; 3000 gals.
Ingredients;
Formaldehyde ~ aqueous 44% s~lution 2235 gals.
phenol - U~S.P. 98~ 912 gals.
Ca~QH12~Beachville Chemical Hi~h
Calcium Hydroxide Powder
lQ taken as 99~ pure880 lbs.
Procedure:
The 3,000 gals. reactor was loaded with formaldehyde
and phenol. The agitator was started. The catalyst (Ca(OH)2)
was poured in over a period of about one hour and 35 minutes.
The temperature at this point was about 86 F. It was
held at 86F for about 25 minutes, then the temperature was raised
to 110F in 32 minutes. The temperature was held at 110F for
about 28 minutes. The temperature was increased to 125F in 20 ~ -
minutes. The temperature was held at 125 F for about 40 minutes.
2Q The temperature was increased to 150 F in 50 minutes. The temper-
ature was held at 150F for about 55 minutes to a free formalde-
hyde of 8.20~. The mixture was cooled to 80F. The final pH was
8.55.
Results~
Free phenol - 0.3%
The resin was neutralized with carbon dioxide to a pH ~;
of 7.8
Organic solids: 44.5
Gel time at 266F: 512 seconds
Results of silylization and gas chromatographic study of
resulting 1:3.7 Resin, as charted. From the chart the ratios of
chosen peaks were calculated.
'~
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,: :
phenol - 3.9
' O-methylol - 6.3
P-methylol 4.4
O-p di-methylol - 11.7
2,4,6-tri-methylol - 57.3
~ di-phenyl - 16~4
-I (4)
EXAMPLE 6:
Production of a calcia catalyzed resin of the starting
ratio 1 mol phenol to 3.8 mol formaldehyde, suitable for use in
binders, particularly in varying combinations with urea.
Batch s-i-ze: 2400 gals.
Ingredients:
Formaldehyde- 1804 gals. ~;
Phenol - 721 gals.
Ca(OH2) - Hlgh Calcium
Beachville chemical hydroxide - Power
Ca(OH~2 taken as 91.4% - 750 lbs.
., ,
Procedure:
. :
The 3,000 gal~ reactor ~as loaded with formaldehyde and
2Q phenol~ The agitator was started~ The catalyst (calcium hydroxide)
was poured in over a period of three hours~ The temperature was
allowed to rise to 84 F~ When all the catalyst was loaded, the
temperature was allowed to rise to 90F. then 100F and then to
110 F. All these steps were carried out within one hour. The tem-
perature was h~Id at 110F for about 1/2 hour. The temperature
was increased to 120F in 15 minutes. The temperature was held
o
at 120 F for about 15 minutes. The temperature was increased to
130F in ahout 15 minutes. The temperature was held at 130F for
about one hour. The temperature was increased to 140 F in about
~ .
3Q 30 minutes. The temperature was allowed to rise to 147F in about
26 minutes. The temperature was held at 147F. for about 30 min-
utes to a free formaldehyde of 10.5%. The mixture was cooled to
- 15 -
76 F. The pH at the end of re~ction was 8.45.
The resin was neutralized with CO2 to a pH of 7.2.
Results:
Organic solids: 39.63~
Gel time at 266 F: 711 secs.
Free phenol: .14%
EXAMPLE 7:
Charge Ratio: phenol:formaldehyde 1:4
Ingredients:
formaldehyde - aqueous - 44% solution2218.80 gms
phenol - USP 98% 781.20 gms
calcium oxide - Ashgrove Springfield high
calcium pebble quicklime - CaO
96.3~ ground to (-10) mesh on
U. S. standard 55.7 gms
Procedure:
The formaldehyde was poured into the glass reactor.
The agitator was started. Phenol wa~ added, followed by
calcium oxide. The temperature was raised to 100F. in a period ;
of 10 minutes and the temperature was held at this point for
25 minutes. The temperature was raised to 110F. in 30 minutes,
and held at this point for 1 hour. The temperature was raised
to 120F. in 30 minutes, and held there for 1 hour. The
temperature was raised to 130F. in 30 minutes, and held for
1 hour. The temperature was raised to 140F. in 30 minutes,
and held there until a free formaldehyde of 10.7%. The mixture
was cooled to 75F. The pH at the end of the reaction was 8.6.
The resin was neutralized with CO2 to a pH of about 7.2.
Results:
Organic solids: 40.2% Cone efficiency: 82.4%
Gel time at 266 F: 655 seconds
Free phenol: 0.29%
EXAMPLE 8:
Binder preparation:
135 grams of nearly neutral phenolic resin resulting
from Example 1 (1:2.8 charge ratio - 48.44~ organic solids) was
- 16 ~
~,
.~, . . .
mixed wlth 10 gra~s o ~ 10~ ~mmoni,u~ sulphate solution.~ Then 35
grams of urea were added. This was mixed well until the urea was
fully dissolved. The ~ollowing were added to the mixture: 1 gram
of ammonium hydroxide, 1 gram of a 10~ silicone solution and 20
grams of a 50~ oil emulsion~ The mixture was diluted further down
to 20% organic solid ~y adding 350 grams of water. The resulting
co-condensation product was found t:o have very satisfactory charac- ',
teristics for ~inder formulation. It had a standard tensile
strength ~psi) of 717 dry and 442 wett and had a gel time of 740 ~ '
seconds at 266 F~
i EXAMPLE 9:
Laboratory preparation of a calcia catalyzed resin of a
starting ratio of 1 mol phenol to 3.6 moles formaldehyde.
Charge ratio: phenol:formaldehyde - 1:3.6
Ingredients:
.. ,
- formaldehyde - aqueous - 44% sol.2077 gms
phenol - USP 98% 809 gms
Calcium hydroxide (99.3%) 73.9 gms
Procedure:
2Q ' The formaldehyde and phenol was loaded in the 3 liter
glass reactor. The agitator was started. Then the calcium hy- ~ ;
droxide was added. The temperature was allowed to rise to 100F.
The temperature was held at 100F for about 1 hour. The tem-
perature was increased to llOOF. The temperature was held at
110F for about 1 hour. The temperature was increased to 125 F.
The temperature was held at 125F for about 1 hour. The tempera-
ture uas increased to 140 F. The temperature was held at 140F
for about 1 hour. The temparature was increased to 150F. The
temperature was maintained at 150 F until the free formaldehyde
was 8.45%, and then cooled to room temperature. The pH at the
,~ end of the reaction was 8.50.
, - 17 -
:'
Results:
Organic solids - 41,38% Tensile strength ~ Dry - 852 psi.
~et - 504 psi
% Free phenol - .2%
Estimated gel time at 266 F for a neutralized resin
P~ 7 5 r was 500 secs.
The resin was incorporated into binder formulation having
the following composition:
54~ Calc~a catalyzed phenol formaldehyde resin; ratio
1.3~6
46% urea
1% CNH4~2 SO4
0.1% A-1120 silicone
The resulting binder was very satisfactory for the
bonding of glass fi~re mats as well as other applications.
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18
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