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Description  |
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BACKGROUND OF THE INVENTION
This invention relates to a novel and economical process to break down
particles of cellulose-containing plants into smaller polymers and
compounds, and in the process, they react with the oxidated silicon
compounds which are highly reactive chemically and are soluble in water
and/or common organic solvents.
This process requires temperatures high enough to melt the solid alkali
metal hydroxide in order for it to react with the cellulose-containing
plants and oxidated silicon compounds. It is not necessary to remove the
lignin from wood in the process of this invention. When an organic or
inorganic acid compound is added to the alkali metal-cellulose-silicate
condensation product, carbon dioxide is given off. This carbon dioxide may
be used to produce foamed products. The alkali metal-cellulose, silicate
condensation product is a dark brown, said product which softens at about
150.degree. C. and becomes a thick liquid between 150.degree. C. to
200.degree. C.
When wood is used as the cellulose-containing plant, the usual
lignin-cellulose bond is not broken in most cases, but the molecules of
cellulose are broken down into smaller molecules and react with the
oxidated silicon compounds to produce alkali metal-cellulose-silicate
condensation products. These condensation products are highly reactive
chemically, especially with aldehydes, furan compounds, polyisocyanates,
polyurethane prepolymers, polyisocyanate silicate prepolymers,
isocyanates, ketones, vinyl acetate, acrylic acid monomers, allyl halides,
polyfunctioning alkylating agents, monofunctional alkylating agents,
acrylic acid compounds with other vinyl monomers, epihalohydrins with
polyamines, sulfur, silicon halides, organic polyhalides and polyamines,
furfuryl alcohol, compounds which contain halogen atoms capable of being
quaternized or R-SO.sub.2 -groups, epoxide compounds, aldehydes and
phenols, aldehydes and amino compounds, vinyl acetate with other vinyl
monomers, halodydrins and mixtures thereof.
An aqueous solution of the alkali metal-cellulose-silicate condensation
product may be used commercially to react with polyisocyanates,
isocyanate-terminated polyurethane prepolymers, polyisocyanate silicate
prepolymers and isocyanate-terminated polyurethane silicate prepolymers.
The aqueous solution of the alkali metal-cellular-silicates may produce
novel and useful products by being polymerized with aldehydes, furfuryl
alcohol, halohydrins, epihalohydrins and polyamines, ketones, organic
epoxides, vinyl monomers, allyl halides, organic polyhalides, organic
halides, organic acid sulfates, organic poly(acid sulphates), organic
nitrates, organic polynitrates, organic acid phosphates, organic poly(acid
phosphates), organic bicarbonates, organic poly(bicarbonate compounds
containing radicals), organic compounds containing formate radicals,
organic compounds containing poly(formate) radicals, organic compounds
containing acetate, propionate laurate, oleate, stearate, oxalate, acid
malonate, acid tartrate, acid citrate radical and mixtures thereof, sulfur
and mixtures thereof.
The water-soluble alkali metal-cellulose-silicate condensation product may
be precipitated by the addition of a salt-forming compound, such as an
organic or inorganic acid. The water is filtered off. The water contains
5% to 30% by weight of water-soluble cellulose-containing plant polymers;
these may be recovered by evaporating the water. The precipitated
cellulose-silicate condensation product is in the form of dark brown- to
black-colored fine particles which are soluble in acetic acid, alcohols,
dilute alkali hydroxide solutions and other organic solvents.
The cellulose-silicate reaction product will react chemically with
isocyanate compounds, polysocyanate compounds, polythiocyanates,
thiocyanates, polyurethane prepolymers, polyisocyanate silicate
prepolymers, polyurethane silicate prepolymers, silicon halides,
polycarboxyl acids and their corresponding anhydrides, organic epoxides,
aldehydes, ketones, furfuryl alcohol, epihalohydrins and mixtures thereof.
At least 3 components are used to produce alkali metal-cellulose-silicate
condensation product such as:
Component A: Cellulose-containing plants;
Component B: Oxidated silicon compound;
Component C: Alkali metal hydroxide.
Component A
Any suitable cellulose-containing plant or the products of
cellulose-containing plants which contain cellulose may be used in this
invention. The plant material is preferred to be in the form of small
particles such as sawdust. In nature, cellulose is widely distributed. It
is found in all plants, and they may be used in this process, preferably
in a dry, small-particle form.
Suitable cellulose-containing plants include, but are not limited to,
trees, e.g., spruce, pine, hemlock, fir, oak, ash, larch, birch, aspen,
poplar, cedar, beech, maple, walnut, cypress, redwood, cherry, elm,
chestnut, hickory, locust, sycamore, tulip, tupelo, butternut, apple,
alder, magnolia, dogwood, catalpa, boxwood, crabwood, mahogany,
greenheart, lancewood, letterwood, mora, prima vera, purpleheart,
rosewood, teak, satinwood, mangrove, wattle, orange, lemon, logwood,
fustic, osageoragane, sappanwood, Brazilwood, barwood, camwood,
cottonwood, sandalwood, rubber, gutta, and mesquite; shrubs, e.g.,
oleander, cypress, junipers, acanthus, pyracantha, lugustrum, lantana,
beugainvilla, azalea, feijoa, ilex, fuchsia, hibiscus, datura, holly,
hydrangea, jasmine, eucalyptus, cottoneaster, xylosma, rhododendron,
castor bean, eugenia, enonymus, fatshedera, aralia, etc.; agricultural
plants, e.g., cotton, cotton stalks, corn stalks, corn cobs, wheat straw,
oat straw, rice straw, cane sugar (bagasse), soybean, stalks, peanut
plants, pea vines, sugar beet waste, sorghum stalks, tobacco stalks, maize
stalks, barley straw, buckwheat straw, quinoa stalks, cassava, potato
plants, legume vines and stalks, vegetable (inedible portion), etc.;
weeds, grasses, vines, kelp, flowers, algae and mixtures thereof. Wood
fibers and cotton fibers are the preferred cellulose-containing materials.
The waste products of agricultural plants may be air-dried, then ground
into small particles and used in this invention. Commercial waste products
containing cellulose, e.g., paper, cotton clothes, bagasse wallboard, wood
products, etc.; may be used in this invention. Wood with the lignin
removed (wood pulp) may be used in this invention. Cellulose-containing
plants which have been partially decomposed, such as humus, peat and
certain soft brown coal may be used in this invention.
Other products of plants may be recovered in the process of this invention
such as waxes, gums, oils, sugars, alcohols, agar, rosin, turpentine,
resins, rubber latex, dyes, etc.
Component B
Any suitable oxidated silicon compound may be used in this invention.
Suitable oxidated silicon compounds include silica, e.g., hydrated silica,
hydrated silica containing Si-H bonds (silicoformic acid), silica sol,
silicic acid, silica, etc.; alkali metal silicates, e.g., sodium silicate,
potassium silicate, lithium silicate, etc., natural silicates with free
silicic acid groups and mixtures thereof.
Silica is the preferred oxidated silicon compound.
Component C
Any suitable alkali metal hydroxide may be used in this invention. Suitable
alkali metal hydroxides include sodium hydroxide, potassium hydroxide and
mixtures thereof. Sodium hydroxide is the preferred alkali metal
hydroxide.
The alkali metal-cellulose-silicate condensation product may be reacted
with inorganic acids, e.g., sulfuric acid, hydrochloric acid, nitric acid,
phosphoric acid, sulphurous acid, hypophosphorous acid, fluorbaric acid,
etc.; organic acid, e.g., acetic acid, propionic acid, glycolic acid,
lactic acid, succinic acid, tartaric acid, oxalic acid, phthalic acid,
trimetallitic acid and the like; phosphine acid, phosphonous acid,
phosphonic acid, amidosulphonic acid, etc.; inorganic hydrogen-containing
salts e.g., sodium hydrogen sulphate, potassium hydrogen sulphate, sodium
dihydrogen phosphate, potassium dihydrogen phosphate and the like, to
produce cellular solid cellulose-silicate products. Carbon dioxide is
released in the reaction to produce air cells in the cellulose-silicate
products. Further examples of acids may be found in German Pat. No.
1,178,586 and in U.S. Pat. No. 3,480,592, and these acids may be used in
this invention.
The acid comounds may also be used to react with the alkali metal atoms in
the alkali metal-cellulose-silicate condensation product to produce a salt
and also release CO.sub.2 which expands the cellulose-silicate and the
cellulose-silicate reaction products into cellular solid products. The
acid compounds may also be used as a catalyst in the reactions to produce
formed aminoplast-cellulose-silicate solid products, foamed
phenoplast-cellulose-silicate solid products, aldehyde-cellulose-silicate
cellular solid products, polyurethane-cellulose-silicate cellular solid
products and cellulose-silicate cellular products.
Any suitable aldehyde may be used in this invention, such as formaldehyde,
acetaldehyde, butyl aldehyde, chloral, acrolein, furfural, benzaldehyde,
crotonaldehyde, propionaldehyde, pentanals, hexanals, heptanals, octanals
and their substitution products, semi-acetals and full acetals,
paraformaldehyde and mixtures thereof. Compounds containing active
aldehyde groups such as hexamethylene tetramine may also be used to
produce aldehyde-cellulose-silicate cellular solid or solid reaction
products.
Any suitable amino compound may be used in this invention to produce
aminoplast-cellular-silicate reaction products such as urea, thiourea,
alkyl-substituted thiourea; alkyl-substituted ureas, melamine, aniline,
quanidine, saccharin, dicyandiamide, benzene sulfonamides, toluene
sulfonamide, aliphatic and aromatic polyamines and mixtures thereof. Urea
is the preferred amino compound, and formaldehyde is the preferred
aldehyde when used with an amino compound.
Any suitable phenol compound may be used in this invention to produce
phenolplast-cellulose-silicate cellular solid or solid reaction products
such as phenol, p-cresol, o-cresol, m-cresol, cresylic acid, xylenols,
resorcinol, chashew nut shell liquid, anacordol, p-tert-butyl phenol,
Bisphenol A, creosote oil, 2,6-dimethylphenol and mixtures thereof. Phenol
is the preferred phenol compound and formaldehyde is the preferred
aldehyde when used with a phenol compound.
Any suitable mixture of the amino compounds and phenol compounds with an
aldehyde may be used in this invention to produce
aminoplast-phenolplast-cellulose-silicate solid or cellular solid
products.
Any suitable organic polyisocyanate may be used according to the invention,
including aliphatic, cycloaliphatic, araliphatic, aromatic and
heterocyclic polyisocyanates. Suitable polyisocyanates which may be
employed in the process of the invention are exemplified by the organic
diisocyanates which are the compounds of the general formula:
O.dbd.C.dbd.N--R--N.dbd.C.dbd.O
where R is a divalent organic radical such as an alkylene, aralkylene or
arylene radical. Such suitable radicals may contain, for example, 2 to 20
carbon atoms. Examples of such diisocyanates are:
tolylene diisocyanate
p,p'-diphenylmethane diisocyanate (sic)
phenylene diisocyanate
m-xylylene diisocyanate
chlorophenylene diisocyanate
benzidene diisocyanate
naphthylene diisocyanate
decamethylene diisocyanate
hexamethylene diisocyanate
pentamethylene diisocyanate
tetramethylene diisocyanate
thiodipropyl diisocyanate
propylene diisocyanate
ethylene diisocyanate
Other polyisocyanates, polyisothiocyanates and their derivatives may be
equally employed. Fatty diisocyanates are also suitable and have the
general formula
##STR1##
where s+y totals 6 to 22 and z is 0 to 2, e.g., isocyanastearyl
isocyanate.
It is generally preferred to use commercially readily available
polyisocyanates, e.g., tolylene-2,4- and -2,6-diisocyanate and any
mixtures of these isomers ("TDI"), polyphenyl-polymethyleneisocyanates
obtained by aniline-formaldehyde condensation followed by phosgenation
("crude MDI"), and modified polyisocyanate containing carbodiimide groups,
allophanate groups, isocyanurate groups, urea groups, imide groups, amide
groups or biuret groups, said modified polyisocyanates prepared by
modifying organic polyisocyanates thermally or catalytically by air,
water, urethanes, alcohols, amides, amines, carboxylic acids, or
carboxylic acid anhydrides. Phosgenation products or condensates of
aniline or anilines alkylsubstituted on the nucleus, with aldehydes or
ketones may be used in this invention. Solutions of distillation residues
accumulating during the production of tolylene diisocyanates, diphenyl
methane diisocyanate, or hexamethylene diisocyanate, in monomeric
polyisocyanates or in organic solvents or mixtures thereof may be used in
this invention. Organic triisocyanates such as triphenylmethane
triisocyanate may be used in this invention. Cycloaliphatic
polyisocyanates, e.g., cyclohexylene-1,2-; cyclohexylene 1,4-; and
methylene-bis-(cyclohexyl-4,4') diisocyanate may be used in this
invention. Suitable polyisocyanates which may be used according to the
invention are desired, e.g., by W. Siefkin in Justus Liebigs Annalen der
Chemie, 562, pages 75 to 136. Inorganic polyisocyanates are also suitable
according to the invention.
Organic polyhydroxyl compounds (polyols) may be used in this invention with
polyisocyanates or may be first reacted with a polyisocyanate to produce
isocyanate-terminated polyurethaneprepolymers and then also used in this
invention.
Reaction products of from 50 to 99 mols of aromatic diisocyanates with from
1 to 50 mols of conventional organic compounds with a molecular weight of,
generally, from about 200 to about 10,000, which contain at least two
hydrogen atoms capable of reacting with isocyanates, may also be used.
While compounds which contain amino groups, thiol groups, carboxyl groups
or silicate groups may be used, it is preferred to use organic
polyhydroxyl compounds, in particular, compounds which contain from 2 to 8
hydroxyl groups, especially those with a molecular weight of from about
800 to about 10,000 and preferably from about 1,000 to about 6,000, e.g.,
polyesters, polyethers, polythioethers, polyacetals, polycarbonates or
polyester amides containing at least 2, generally from 2 to 8, but
preferably dihydric alcohols, with the optional addition of trihydric
alcohols, and polybasic, preferably dibasic, carboxylic acids. Instead of
the free polycarboxylic acids, the corresponding polycarboxylic acid
anhydrides or corresponding polycarboxylic acid esters of lower alcohols
or their mixtures may be used for preparing the polyesters. The
polycarboxylic acid may be aliphatic, cycloaliphatic, aromatic and/or
heterocyclic and may be substituted, e.g., with halogen atoms and may be
unsaturated; examples include: saccinic acid, adipic acid, sebacic acid,
suberic acid, analaic acid, phthalic acid, phthalic acid anhydride,
isophthalic acid, tetrahydrophthalic acid anhydride, trimellitic acid,
hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride,
endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride
fumaric acid, maleic acid, maleic acid anhydride, dimeric and trimeric
fatty acid such as oleic acid, optionally mixed with monomeric fatty
acids, dimethylterephthalate and bis-glycol terephthalate. Any suitable
polyhydric alcohol may be used such as, for example, ethylene glycol;
propylene-1,2- and -1,3-glycol; butylene-1,4- and -2,3-glycol;
hexane-1,6-diol; octane-1,8-diol; neopentyl glycol,
cyclohexanedimethanol-(1,4-bis-hydroxymethylcyclohexane);
2-methylpropane-1,3-diol; glycerol; trimethylol propane;
hexane-1,2,6-triol; butane-1,2,4-triol; trimethylol ethane;
pentaerythritol; quinitol; mannitol and sorbitol; methylgrycoside;
diethyliene glycol; triethylene glycol; tetraethylene glycol; polyethylene
glycols; dipropylene glycol; polypropylene glycols; dibutylene glycol and
polybutylene glycols. The polyesters may also contain a proportion of
carboxyl end groups. Polyesters of lactones, such as
.epsilon.-caprolactone, or hydroxycarboxylic acid such as
.omega.-hydroxycaproic acid, may also be used.
The polyethers with at least 2, generally from 2 to 8 and preferably 2 or
3, hydroxyl groups used according to the invention are known and may be
prepared, e.g., by the polymerization of epoxides, e.g., ethylene oxide
prepolymer oxide, butylene oxide, tetrahydrofuran oxide, styrene oxide or
epichlorohydrin, each with itself, e.g., in the presence of BF.sub.3, or
by addition of these epoxides, optionally as mixtures or successively, to
starting components which contain reactive hydrogen atoms such as alcohols
or amines, e.g., water, ethylene glycol; propylene-1,3- or 1,2-glycol;
trimethylol propane; 4,4-dihydroxydiphenylpropane, aniline, ammonia,
ethanolamine or ethylenediamine; sucrose polyethers such as those
described, e.g., in German Auslegeschriften Nos. 1,176,358 and 1,064,938
may also be used according to the invention. It is frequently preferred to
use polyethers which contain predominantly primary OH groups (up to 90% by
weight, based on the total OH groups contained in the polyether).
Polyethers modified with vinyl polymers such as those which may be
obtained by polymerizing styrene or acrylonitrites in the presence of
polyethers, (U.S. Pat. Nos. 3,383,351; 3,304,273; 3,323,093 and 3,110,695;
and German Pat. No. 1,152,536) and polybutadienes which contain OH groups
are also suitable.
By "polythioethers" are meant, in particular, the condensation products of
thiodiglycol with itself and/or with other glycols, dicarboxyl acids,
formaldehyde, aminocarboxylic acids or amino alcohols. The products
obtained are polythio-mixed ethers or polythioether ester amides,
depending on the co-component.
The polyacetals used may be, for example, the compounds which may be
obtained from glycols, 4,4'-dihydroxydiphenylmethylmethane, hexanediol,
and formaldehyde. Polyacetals suitable for the invention may also be
prepared by the polymerization of cyclic acetals.
The polycarbonants with hydroxyl groups used may be of the kind, e.g.,
which may be prepared by reaction diols, e.g., propane-1,3-diol;
butane-1,4-diol; and/or hexane hexane-1,6-diol or diethylene glycol,
triethylene glycol tetraethylene glycol, with diarylcarbonates, e.g.,
diphenylcarbonates or phosgene.
The polyester amides and polyamides include e.g., the predominantly linear
condensates obtained from polyvalent saturated and unsaturated carboxylic
acids or their anhydrides and polyvalent saturated and unsaturated amino
alcohols, diamines, polyamines and mixtures thereof.
Polyhydroxyl compounds which contain urethane or urea groups, modified or
unmodified natural polyols, e.g., castor oil, carbohydrates and starches,
may also be used. Additional products of alkylene oxides with phenol
formaldehyde resins or with ureaformaldehyde resins are also suitable for
the purpose of the invention.
Organic hydroxyl silicate compound as produced in U.S. Pat. No. 4,139,549
may also be used in this invention.
Examples of these compounds which are to be used according to the invention
have been described in High Polymers, Volume XVI, "Polyurethanes,
Chemistry and Technology", published by Saunders-Frisch Interscience
Publishers, New York, London, Volume I, 1962, pages 32 to 42 and pages 44
to 54, and Volume II, 1964, pages 5 and 6 and pages 198 and 199; and in
Kunststoff-Handbuch, Volume VII, Vieweg-Hochtlen, Carl-Hanser-Verlag,
Munich, 1966, on pages 45 to 71.
If thepolyisocyanates or the prepolymer which contains NCO groups have a
viscosity above 2000 cP at 25.degree. C., it may be advantageous to reduce
the viscosity thereof by mixing it with a low-viscosity organic
polyisocyanate and/or an inert blowing agent or solvent.
Inorganic polyisocyanates and isocyanate-terminated polyurethane silicate
prepolymers may also be used in this invention.
When an aqueous solution of alkali metal cellulose silicate is being used
to react with, or as a curing agent for, polyisocyanate, and in certain
cases where the alkali metal cellulose silicate is reacting with
polyisocyanates, it is advantageous to use activators (catalysts) such as
tertiary amines, e.g., triethylamine, tributylamine, N-methyl morpholine,
N-ethyl morpholine, tetramethylenediamine, pentamethyldiethylenetriamine,
triethanolamine, triisopropanolamine, organo-metallic compound, e.g., tin
acetate, tin oxtoate, tin ethyl hexoate, dibutyl tin diacetate, dibutyl
tin dilaurate and mixtures thereof.
Other examples of catalysts which may be used according to the invention
and details of their action are described in Kunststoff-Handbuch, Volume
VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966,
on pages 96 and 102. Silammines are suitable catalysts, e.g.,
2,2,4-trimethyl-2-silamorpholine or 1,3-diethyl aminoethyltetramethyl
disiloxane. Suitable catalysts are also tetraalkyl ammonium nydroxides,
alkali phenolates, alkali metal hydroxides, alkali alcoholates and
hexahydrotriazines.
Suitable flame-resistant compounds may be used in the products of this
invention such as those which contain halogen or phosphorus, e.g.,
tributylphosphate; tris(2,3-dichloropropyl)-phosphate;
polyoxypropylenechloromathylphosphonate; cresyldiphenylphosphate;
tricresylphosphate; tris-(beta-chloroethyl)-phosphate;
tris-(2,3-dichloropropyl)-phosphate; triphenyl-phosphate; ammonium
phosphate; perchlorinated diphenyl phosphate; perchlorinated terephenyl
phosphate; hexabromocyclodecane; tribromophenol; dibromopropyldiene,
hexabromobenzene; octabromodiphenylether; pentabromotoluol;
poly-tribromostyrol; tris-(bromocresyl)-phosphate; tetrabromobis-phenol A;
tetrabromophthalic acid anhydride; octabromodiphenyl phosphate;
tri-(dibromopropyl)-phosphate; calcium hydrogen phosphate; sodium or
potassium dihydrogen phosphate; disodium or dipotassium hydrogen
phosphate; ammonium chloride; phosphoric acid; polyvinylchloride tetomers
chloroparaffins as well as further phosphorus- and/or halogen-containing
flame-resistant compounds as they are described in "Kunststoff-Handbuch",
Volume VII, Munich, 1966, pages 110 and 111, which are incorporated herein
by reference. The organic halogen-containing components are, however,
preferred in the polyurethane-cellulose-silicate products. In the
production of aldehyde-cellulose-silicate, aminoplast-cellulose-silicate,
phenoplast-cellulose-silicate cellular products, and phosphoric acid may
be used to react with the alkali metal atoms, thereby producing an alkali
metal hydrogen phosphate which may be used as the flame-resistant
compound.
DETAILED DESCRIPTION OF THE INVENTION
The preferred process to produce the alkali metal-cellulose-silicate
condensation product is to mix about 3 parts by weight of air-dried fine
particles of a plant, 1 to 2 parts by weight of an oxidated silicon
compound and 2 to 5 parts by weight of an alkali metal hydroxide compound,
then to heat the mixture at ambient pressure and 150.degree. C. to
220.degree. C. for 5 to 60 minutes, thereby producing an alkali
metal-cellulose-silicate condensation product.
The alkali metal-cellulose-silicate polymer softens or melts into a thick
liquid at 150.degree. C. to 220.degree. C. and when it cools, it forms a
dark-brown solid mass. The mass is easily broken up into fine particles
and is soluble in organic solvent, e.g., alcohols, polyols,
epichlorohydrin, chlorohydrin, etc., and/or water.
The alkali metal-cellulose-silicate condensation product may be neutralized
with an acid compound to a pH of about 7 to produce a foamed
cellulose-silicate product by the production of CO.sub.2 when the acid
reacts with the alkali metal atoms to form a salt. The foamed
cellulose-silicate product may be optionally washed to remove the salt,
then dried, and may be utilized for thermal- and sound-insulation material
in construction of buildings, cars, boats and airplanes. The foamed
cellulose-silicate may also be reacted with polyurethane and/or
isocyanate-terminated polyurethane prepolymers.
In an additional preferred process, about 2 parts by weight of the alkali
metal-cellulose-silicate condensation product produced by the process of
the invention are mixed with 1 to 5 parts by weight of an aldehyde, then
agitated at ambient temperature and pressure for 10 to 60 minutes, thereby
producing an aldehyde-alkali metal-cellulose-silicate copolymer. The
aldehyde-alkali metal-cellulose-silicate copolymer is then reacted with an
acid compound until the pH is 6 to 7, thereby producing a foamed
aldehyde-cellulose-silicate copolymer. The salt is removed by washing and
filtering.
In an additional preferred process, about 2 parts by weight of the alkali
metal-cellulose-silicate condensation product produced by the invention
are mixed with 1 to 5 parts by weight of an amino compound and 0.5 to 5
mols of an aldehyde for each mol of the amino compound, then agitated at a
temperature and pressure between ambient temperature and 100.degree. C.
for 10 minutes to 12 hours, thereby producing an aminoplast-alkali
metal-cellulose-silicate resin; then an acid compound is added until the
pH is 5 to 7, while agitating until the mixture begins to expand, thereby
producing a cellular solid aminoplast-cellular-silicate product.
In an additional preferred process, about 2 parts by weight of the alkali
metal-cellulose-silicate condensation product produced by the process of
this invention are mixed with 1 to 5 parts by weight of a phenol compound
and 1 to 5 mols of an aldehyde per mol of the phenol compound, then
agitated at a temperature from ambient to 100.degree. C. for 10 minutes to
12 hours, thereby producing a phenoplast-alkali metal-cellulose-silicate
resinous product; then an acid compound is added until the pH is 5 to 7
while agitating for a few seconds until the mixture begins to expand,
thereby producing a cellular solid phenoplast-cellulose-silicate product.
The processes to produce cellular solid aminoplast-cellulose-silicate
products and phenoplast-cellulose-silicate cellular solid products may be
combined to produce cellular solid
phenoplast-aminoplast-cellulose-silicate products.
In an additional preferred process, 1 to 4 parts by weight of the alkali
metal-cellulose-silicate condensation product produced by the process of
this invention and about 3 parts by weight of an isocyanate-terminated
polyurethane prepolymer are rapidly and thoroughly mixed at ambient
temperature and pressure, and in a few seconds to about 120 minutes, the
mixture expands 3 to 12 times its original volume to produce a cellular
solid polyurethane-cellulose-silicate product.
In an additional preferred process, one part by weight of an aqueous
solution containing 20% to 60% by weight of the alkali
metal-cellulose-silicate product produced by the process of this invention
is mixed at ambient temperature and pressure with 1 to 10 parts by weight
of an organic polyisocyanate or polyisothiocyanate and the mixture is
optionally heated up to 100.degree. C.; then in a few seconds to 120
minutes, the reaction is complete, thereby producing a
polyisocyanate-cellulose-silicate cellular solid or solid product.
In an additional preferred process, about 10 parts by weight of an aqueous
solution containing 20% to 60% by weight of the alkali
metal-cellulose-silicate condensation product as produced by the process
of this invention are mixed, at ambient pressure and temperature to
100.degree. C., with 10 to 100 parts by weight of an isocyanate-terminated
polyurethane prepolymer and optionally up to 0.01 part by weight of an
amine catalyst; then in a few seconds to 120 minutes, the reaction is
complete, thereby producing a polyurethane-cellulose-silicate cellular or
solid product.
In an additional preferred process, 1 to 3 parts by weight of the alkali
metal-cellulose-silicate condensation product as produced by the process
of this invention, 1 to 3 parts by weight of a polyol and 3 parts by
weight of an organic polyisocyanate or polyisothiocyanate are rapidly
mixed at ambient temperature and pressure; then in a few seconds to 120
minutes, the reaction is complete, thereby producing a
polyurethane-cellulose-silicate cellular solid or solid product.
In an additional preferred process, 2 parts by weight of the alkali
metal-cellulose-silicate condensation product as produced by the process
of this invention are mixed with 1 to 4 parts by weight of an organic
polyisocyanate, then agitated for 10 to 60 minutes at a temperature
between 20.degree. C. to 70.degree. C., thereby producing a
polyisocyanate-alkali metal-cellulose-silicate prepolymer; then 10% to
100% by weight of a curing agent, based on the weight of the prepolymer,
is added to the prepolymer while agitating at 20.degree. C. to 80.degree.
C. for 5 to 20 minutes, thereby producing a cellular solid or solid
polyisocyanate-cellulose-silicate product.
In an additional preferred process, 1 to 3 parts by weight of the alkali
metal cellulose produced by the process of this invention, 1 to 3 parts by
weight of a polyol (polyhydroxyl compound) and 1 to 3 parts by weight of
an organic polyisocyanate or polyisothiocyanate are rapidly and thoroughly
mixed at ambient temperature and pressure, and in a few seconds to 5
minutes, the mixture begins to expand, expanding 3 to 12 times its
original volume, thereby producing a tough cellular solid
polyurethane-cellulose-silicate product.
When the alkali metal-cellulose-silicate produced by this invention is
reacted with an acid compound, CO.sub.2 is given off, and a foamed
cellulose-silicate product is produced. In cases where inadequate CO.sub.2
is produced to form adequately expanded cellular solid cellulose-silicate
products, a blowing agent may be used. The blowing agent may be added to
the alkali cellulose-silicate condensation product or to an aqueous
solution of the condensation product before the acid compound is added.
The blowing agent may be also added with the acid compound. The chemical
reaction between the acid compound and the alkali metal atoms will usually
produce enough heat to evaporate or expand the blowing agent; if
necessary, an external source of heat may be used.
Readily volatile blowing agents, e.g., dichlorodifluoromethane,
trichlorofluoromethane, butane, isobutylene, vinyl chloride, etc., may be
used to produce cellular solid products in this invention. In addition,
the liquid reaction mixtures can be expanded into a foam by the
introduction of gases, optionally under pressure, such as air, CF.sub.4,
noble gases and H.sub.2 O.sub.2, the resulting foam being introduced into
the required mold and hardened therein. The resultant foam may optionally
contain foam stabilizers such as surfactants, foam formers, emulsifiers
and, if desired, organic or inorganic fillers or diluents may initially be
converted by blowing gas into a foam, and the resulting foam may
subsequently be mixed in a mixer with the other components, the resulting
mixture being allowed to harden. Instead of blowing agents, it is also
possible to use inorganic or organic, finely-divided hollow bodies such as
expanded hollow beads of glass, plastic, straw, expanded clay, and the
like, for producing foams.
The foams obtainable in this way can be used in either their dry or their
moist form, if desired, after a compacting or tempering process,
optionally carried out under pressure, as insulating materials, cavity
fillings, packaging materials, building materials, etc. They can also be
used in the form of sandwich elements, for example, with metal-covering
layers in house, vehicle and aircraft construction.
It is also possible to introduce into the foaming reaction mixtures,
providing they are still free-flowing, organic and/or inorganic foamable
or already foamed particles such as, for example, expanded clay, expanded
glass, wood, popcorn, cork, hollow beads of plastics such as vinyl
chloride polymers, polyethylene, styrene polymers or foam particles
thereof or even, for example, polysulphene, polyepoxide, polyurethane,
phenoplasts, aminoplasts, polyimide polymers, phenoplast silicates,
aminoplast silicates, epoxy silicate polymers, polyisocyanate polymers,
polyurethane silicate polymers or their reaction mixtures; the foaming
mixture may be allowed to foam through interstitial spaced particles in
packed volumes of these particles and, in this way, insulating materials
can be produced. Combinations of expanded clay, glass or slate are
especially preferred with the reaction mixture, according to the
invention.
It is also possible to introduce into the foaming reaction mixtures,
providing they are still free-flowing at a predetermined temperature, a
blowing agent which is capable of evaporation or of gas formation at this
temperature, such as, for example, a halogenated hydrocarbon. The initial
liquid mixture formed can be used not only for producing uniform foams or
non-uniform foams containing foamed or unfoamed fillers, but it can also
be used to foam through any given webs, woven fabrics, lattices,
structural elements or other permeable structures of foamed materials,
resulting in the formation of composite foams with special properties, for
example, favorable flame behavior, which may optionally be directly used
as structural elements in the building, furniture, vehicle and aircraft
industries.
The cellular solid products (foams) according to the invention can be added
to soil in the form of crumbs, optionally in admixtures with fertilizers
and plant-protection agents, in order to improve its agrarian consistency.
Since the hardened foams obtained by the process according to the invention
can show considerable porosity after drying, they are suitable for use as
drying agents because they can absorb water; however, they can also be
charged with active substances or used as catalyst supports or as filters
and absorbents.
On the other hand, the foams can be subsequently lacquered, metallized,
coated, laminated, galvanized, subjected to vapor deposition, bonded or
flecked in either their moist or their dry form or in impregnated form.
The moldings can be further processed in their moist or their dry form,
for example, by sawing, milling, drilling, planing, polishing and other
machining techniques. The optionally filled moldings can be further
modified in their properties by thermal after-treatment, oxidation
processes, hot-pressing, sintering processes or surface melting or other
consolidation processes. Suitable mold materials include inorganic and/or
organic foamed or unfoamed materials such as metals, for example, iron,
nickel, fine steel, lacquered or, for example, teflon-coated aluminum,
porcelain, glass, wood, plastics such as PVC, polyethylene, epoxide
resins, ABS, polycarbonate, etc.
Fillers in the form of particulate or powdered materials can be
additionally incorporated into the liquid mixtures of the foamable
reactants for a number of applications.
Suitable fillers include solid inorganic or organic substances, for
example, in the form of powders, granulate, wire, fibers, dumb bells,
crystallites, spirals, rods, beads, | | |
