Note: Descriptions are shown in the official language in which they were submitted.
105Z050
~ This invention relates to a new process for the
production of shaped articles with a cellular structure.
Plastics are the preferred materials for the
manufacture of shaped articles in all kinds of fields.
Plastics articles are easily produced in large numbers,
and present a number of advantages with respect to their
strength. However, the inflammability and combustibility
of these plastics, which are in themselves suited to the
0 use in question, often stand in the way of this use. Thus,
for example, in materials which are used as building
materials or interior furnishings for rooms, not only is
- their inflammability in itself important, but also their
behaviour in a fire in the presence of increasing radiant
heat, their extinguishability, and their heat conductivity,
particularly at high temperature~ abo~e 600~C are ~f
importance. Therefore there has been no shortage of attempts
to make such combustible plastics non-inflammable. For
preference, halogen, phosphorus and antimony compounds
0 are used for this. It has however been shown that in a
number of plastics, many of these flame-retarding components
work their way to the surface of the shaped part and are
removed from there by mechanical effects. In this way
the plastic is constantly losing flame-retarding components,
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105Z050
with consequent increase in the combustibility of the plastic.
Particularly in foam plastics, not inconsiderable
difficulties arise in adapting the products, and shaped
articles made from them, to the re~uirements which are imposed
on flame-proof plastics, particularly when used as building
materials.
According to a process known from German Offen-
legungsschrift 1 544 857, non-combustible sound-proofing
building elements are manufactured by polymerising a water-in-oil
emulsion of styrene and/or methacrylic acid ester and/or vinyl
ester with a minimum water content of 2~%. Non-inflammability is
obtained by the fact that the water of the emulsion stays, to a
large extent, in the building element, and is held there for a
long period. For this reason it is recommended that the outer
surfaces of the elements be covered with metal foil or an alloy foil
made of metal/paper/plastic. The water can also be kept in the
elements made from the emulsion by addition of hydrophilic compounds.
The possibility is also referred to of lastingly reducing the
inflammability of such elements by additionally incorporating
flame-retarding components such as e.g. phosphorus and halogen
compounds. According to this
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lO5Z050
known process, the combustibility of the elements thereby produced
is substantially reduced and, in the event of the elements igniting,
the temperature only rises slowly. For comparison, a plate 5.5 mm
S thick, made of an emulsion with unsaturated polyester and having a
water content of about 80% by weight, coated with aluminium foil
0.1 mm thick and heated with a blow-lamp flame (1150C) on one side,
has, after 3 minutes, a temperature of 90C on the other sidè of the
plate, whereas with a corresponding asbestos sheet of the same
- thickness a temperature of 450C is measured after only 2-minutes.
Certainly, the aluminium foil initially protects the plastic sheet
- from the effect of the heat. However, it cannot be avoided
that the water slowly escapes from the shaped parts produced in
accordance with this previously known process. Conneceed with
this are a gradual shrinkage and dlstortion of the elements, and
also a loss of flame-proofing, corresponding to the quantity of
-
water lost.
Dehydrated cured emulsions or emulsion foams as they will
be called hereafter, cannot be adequately protected by the usual
means from the effècts of flames, on account of their very large
surface area.
; Therefore possibilities have been sought of flame-
proofing emulsion foams in such a way that the shaped
parts produced from them resist even high burning temperatures,
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- 105ZO50
and that this protective effect does not subside as the
density of the emulsion foam decreases.
In British Patent Specificiation No. 1458203
(Application No, 53652/73) I describe and claim a process
for producing shaped articles with a cellular structure
which comprises shaping and curing an emulsion comprising
from 25 to 90 parts by weight of water dispersed in from
75 to 10 parts by we~ght of a liquid synthetic resin-
monomer mixture comprising styrene and/or a methacrylic
; 10 or acrylic acid ester and a copolymerisable unsaturated
. polyester or copolymer of styrene and butadiene, the
emulsion having a dispersion level which is in the
characteristic range (as therein defined) prior to
commencement of curing and the curing being effected at a
i
.~ 15 rate.whereby the emulsion gels before commencement of
disintegration of the emulsion, The expr-ession
. "characteristic range is used in British Patent Specification
No, 1458203 to define a dispersion level range extending
from a lower limit at which the water-in-oil emulsion can
be cured to a shaped article whose volume amounts to at
least 90/O of the volume occupied by the emulsion prior to
commencement of curing to an upper limit at which the water-
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i ~ in-oil emulsion can be cured whilst maintaining at least
90% of the emulsion vo~ume prior to commencement of curing
to a shaped article with a continuous fine-porous structure
which loses at least 20% of the weight of the water
contained in the cured emulsion from a sample with a ratio
of surface to volume of 1,17:1 when dried at a temperature
of 23C and a relative humidity of 60% for 24 hours.
According to the present invention I now provide
a process for producing a shaped article with a cellular
: 10 structure and a water content of not more than 14% by
volume which comprises shaping and curing an emulsion
comprising from 25 to 90 parts by weight of water dispersed
in from 75 to 10 parts by weight of a liquid synthetic resin-
monomer mixture comprising styrene and/or a methacrylic
or acrylic acid ester and a copolymerisable unsaturated ,
: polyester or copolymer of styrene and butadiene and there-
after drying to provide a water content of not more than
14% by volume in the shaped article thus produced; the :
said emulsion containing from 5 to 30% by weight of an ,
inorganic flame-retarding component (as herein defined) in
powder form with an average particle size of not m~ e than
50~ in diameter (the percentage being based on the total
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. weight of emulsion), the emulsion having a dispersion
level which is in the characteristic range (as herein defined)
prior to commencement of curing and the curing being
effected at a rate whereby the emulsion gels before
,, 5 commencement of disintegration of the emulsion,
: The characteristic range is used herein in precisely
; the same sense as in British Patent Specification No,
1458203, It extends from a dispersion level at which
dispersion has just commenced and is minimal up to a level
at which there is an onset of stable dispersion formation
i,e, formation of an emulsion which will not change its
phase structure upon subsequent curing and which does not
decompose as a result of phase change,
The characteristic range of the dispersion level
following the increasing dispersion of the dispersed phase
can be regarded as being capable of subdivision into a lower,
medium and upper portion, If the dispersion level of the
emulsion is set to a value which is in the lower portion of
the characteristic range, by curing of this emulsion
shaped articles are obtained whose base or outer surfaces
have distributed over them a closed and non-porous polymer-
isation layer whilst the remaining portions of the shaped
.
: - -- 7 --
5Z 05~D
article form a coarse to fine cellular structure. These
shaped a.rticles have a sandwich character, whereby the
thickness.of the closed layer and the cell diameter of
the cellular layer decrease with increasing dispersion
level of the emulsion, Inasfar as the cells of the cellular
layerare open-celled the water, optionally after opening
the closed dense polymerisation layer, can be removed by
suction or dried out, If the dispersion level of the
emulsion is set to a value which lies in the middLe portion
of the characteristic range shaped articles are obtained
having a medium to fine structured core surrounded completely
by a thin dense polymer layer. Within this portion of the
characteristic range the skin-like layer becomes thinner
and finally permeable with increasing dispersion level of
the emulsion. In the same way with increasing dispersion
level of the emulsion the cellular structure of the core
becomes.finer, From these shaped articles the water
contained in the cells of the core can be removed despite
the presence of the closed, thin, outer layer by suction
. 20 by opening this layer or can be expelled by drying, provided
that the cells of the core are open, On setting the disp-
ersion level to a value which lies in the upper portion of
., .
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the characteristic range shaped articles are obtained whose
surface has no resin deposits and which overall consists of a
very uniform fine cellular structure with open and/or closed
cells, With increasing dispersion level of the dispersion
~- 5 phase in the emulsiDn the diameter of the cells of the shaped
~; articles produced from the particular emulsion becomes
increasingly smaller. On further increasing the dispersion
level the emulsion passes into the state of absolute
stability and in this state can be completely cured. The
lO onset of this dispersion state occurs at the upper extremity
~ of the characteristic range as herein defined. Inasfar
r as the emulsion is present in the state of absolute
stability its curing leads to shaped articles which
eitherdo not give off the water or only give it off with
15 difficulty,
Water is removed from the cured emulsion preferably
by drying at a temperature of from 15 to 500C. Drying
-~ can of course also be effected if desired at temperatures
of over 500C.
., -
The monomer content of the synthetic resin-monomer
mixture used in the process according to the invention
comprisesstyrene and/or an ester of methacrylic or acrylic
., .
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, ~13
~oszo~o
acid such as for example methyl methacrylate, ethyl
methacrylate, ethylene glycol methacrylate, 1,4-but-2-ene
dimethacrylate, cyclohexyl methacrylate, ethyl acrylate or
1,2-propanediol diacrylate The mixture may also if desired
, contain additional monomers, e,g. a nitrile such as for
example acrylonitrile
t The monomer component of the mixture can if necessary
serve as the solvent or diluent for the synthetic resin
portion This resin portion can be a high molecular
.. 10 weight unsaturated polyester or a copolymer of styrene
and butadiene which is copolymerisable with the monomer
or monomer mixtu~e Particularly suitable are unsaturated
polyesters which are obtained by condensation of dihydric
alcohols, for example ethanediol, 1,2-propandiol, 1,3-
` 15 propandiol, diethylene glycol, 1-allyl-2,3-hydroxypropandiol
and unsaturated a~-ethylenically unsaturated dicarboxylic
acids, for example maleic acid and fumaric acid In
addition the unsaturated polyesters can also contain di-
. and polyvalent carboxylic acids, for example endomethylene
` 20 tetrahydrophthalic acid, tetrahydrophthalic acid, phthalic
.
: acid, succinic acid, adipic acid, propionic acid, benzene
tricarboxylic ~cid and benzene tetracarboxylic acid, and
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1052050
also other low grade alcohols such as benzyl alcohol,
1,2-di(allyloxy)-3-propanolglycerol, pentaerythritol,
as well as hydroxycarboxylic acids, e g 4-hydroxymethyl-
cyclohexane carboxylic acid The use of these substances
. 5 for expanded resin products is described in United States
~eissue Patent 27,444, German DOS 2,046,575 and German
D~S 1,024,564, 1,067,210 and 1,081,222. In conjunction
with self-emulsifying polyesters it is also possible to
use epoxide compounds with more than one epoxide bond as
the polymerisable phase, as indicated in German DOS
1,495,843
- It is particularly advantageous to use a mixture
~~ of styrene and methyl methacrylate in the weight ratio
4 to 4:1 as monomer together with an unsaturated polyester
. 15 copolymerisable therewith In addition it is also
possible to add to the emulsion polymers of high molecular
weight which do not copolymerise with the monomer These
are preferably polymers of styrene, vinyl chloride, esters
- of methacrylic acid and optionally unsaturated polyesters
which are copolymerised with monomers, for example with
styrene or methyi methacrylate,
. In order to form an emulsion of the water-in-oil
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~OSZ050
type, an emulsifying agent with molecules consisting of
hydrophobic and hydrophilic portions is preferably used,
Such emulsifying agents may be used individually or in
admixture,
Emulsifying agents which partially separate in the
~- monomer portion of the water-in-oil emulsion in the
presence of water have proved to be particularly suitable,
The stability of such emulsifying agents can be proved by
,~ a simple test, For this purpose, 5 to 10% by weight (based
on the total weight of the emulsion) of the emulsifying
agent or mixture of emulsifying agents to be tested are
~`~ dissolved in the monomers of the process, A few drops of
water are added to about 10 cc of this solution, In the
'-; case of particularly effective emulsifying agents the
introduction of the water leads to a visible separation,
Examples of low molecular weight water-in-oil
emulsifying agents are esters of higher fatty acids with
polyhydric alcohols, amides of higher fatty acids and salts
of alkylsulphonic acids, Frum the very large number of
' 20 high molecular weight compounds particularly suitable are
`~ polymers or polycondensates which are completely or almost
completely water-insoluble and which containing hydrophilic
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.:
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,
~4~
.~. . ~ ~ . . . . .
-
105;~050
groups such as for example carboxyl, carboxylate,
carboxamide and hydroxyl groups, ester or ether groupings,
amino, ammonium, sulphonic acid and/or sulphoxide groups
Such emulsifying agents are for example described in German
Patent 1,301,511 Copolymers with an acid number between
8 and 12 which consist of units of an ethylenically-
unsaturated carboxylic acid, for example acrylic acid,
; and styrene, and wherein the free carboxyl groups are
wholly or partially neutralised with organic or inorganic
bases, can be used with equal success. It is also
possible to use polymers or copolymers of styrene, methyl
methacrylate or vinyl acetate as the emulsifying agent
,. if these polymers or copolymers are produced in emulsion
polymerisation processes in the presence of persulphates
' 15 and consequently contain sulphonic acid groups Saturated
and unsaturated polyesters can also be effective as
emulsifying agents, particularly if they are partly or
completely saponified with alkali~ or if they contain
an adequate number of free carboxyl groups These
emulsifying agents ~re for example described in detail
in German DAS 1,199,982 or German Patent ~pecification
1,267,845, These can be the same polyesters as are also
~ .
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:
lOSZO~;O
, used as the resin component of the resin - monomer
mixture, It is also possible to use graft copolymers -
which are produced in the presence of polyalkylene oxides
from styrene and which are described for example in German
. 5 DAS 1,169,671 as emulsifiers, It is also possible to use
film-forming polymers, e,g, cyclised rubber or copolymers
. of vinyl compounds with a gr~up having 8 C-atoms described
: in German DAS 1,148,382 as emulsifying agents. It is
also possible to use as emulsifying agents hydrophobic
polymerisation products of organic compounds which contain
0.5 to 60%, preferably 28 to 55%, by weight of oxyethylene
. groups as hydrophilic components, Preferably the
hydrophobic portion of these emulsifying agents can be
. composed of polyoxypropyLene and must then have a
~: 15 molecular weight of over 600, Also copolymers with a
total molecular weight of above 800 which contain 90 to
- 20% by weight of polyoxypropylene glycol and 10 to 80%
by weight of polyoxyethylene glycol are suitable emulsifying
agentssuch as are known from German DOS 1,495,227. -
Further suitable emulsifying agents are described in
German DOS 2,046,575 and 1,928,026. The effectiveness
'oi the en~ls iiyin6 a~ents soluble in the organic phas e
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- 1052050
can be increased by water-soluble l~w molecular weight
organic compounds which contain both a hydrophilic and
- a hydrophobic proportion Compounds of this type are in
particular alcohols, organic acids, ethers, ketones and
wetting agents It is understood that the above-indicated
emulsifying agents can be used individually or in mixture
The quantity of the èmulsifying agent or mixture of emulsifying
agents which is advantageously u~ed is adjusted according
to the desired dispersion level of the emulsion and is
preferably in a range from 0 05 to l~/o by weight (based
on the total weight of the emulsion) 25 to 90 parts by
weight of water are then emulsified in 75 to 10 parts by
weight of this polymerisable mixture. In order to disperse
the water in the organic phase conventional stirrers,
- 15 dissolvers or similar apparatus can be used.
In order to cure the emulsion, curing catalysts are
conveniently added These curing catalysts can be water
soluble, e.g alkali, formaldehyde, sulphoxylates, per-
sulphates, hydrogen peroxide, sodium hydrogen sulphite and
20 cobalt chloride However, it is also~possible to use
catalysts such as benzoyl peroxide, lauroyl peroxide, ethyl
methyl ketone peroxide, cyclohexanone peroxide,
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105Z050
- azodiisobutyryl nitrile, N,N-diisopropyl-p-toluidine,
tertiary amines, such as dimethylparatoluidine, dimethyl-
or diethylaniline and cobalt naphthenate, which are soluble
in the polymerisable phase In some cases it can be
advantageous to use in addition to a water soluble catalyst
one which is soluble in the polymerising phase. These
catalytically active substances are with advantage a~ded in
quantities of 0 1 to 10% based on the total weight of the
emulsion Furthermore wetting agents, inhibitors (e g.
4-ethyl-pyrocatechol, 3-methyl-pyrocatechol, tertiary butyl
.
' pyrocatechol, toluquinol, quinol, 2,5-di-tert.-butylquinoneand p-benzoquinone), cross-linking compounds, softeners,
` fillers and dyes may if desired be added to the emulsion
prior to use.-
` 15 The process of the invention provides shaped ~ -
articles with a cellular structure which is predominantly
- open-pored in character, that is with a major part of the
cells of the structure being open-pored The cells are
preferably as fine as possible with an average cell
- 20 diameter of not more than 50~, and ad~antageously less
than 20~, in which thefLame-retarding component is contained, `
either dissolved or evenly distributed as a fine-particulate
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lOSZOSI~
- solid The use of fire-retarding components in accordance
with the invention makes it possible to produce shaped
articles which are stable even at temperatures above 800C
' thus preventing the spread of fire
The expression "flame retarding component" is
~ used herein to define a component of the emulsion which
i serves to retard burning or to provide resistance to burning
in shaped articles produced therefrom
The flame-retarding components used in accordance
with the present invention preferably have an average
particle size of not more than 20~.
As flame-retarding components, there may for example
. be used, according to the invention, inorganic compounds
which split off water at high temperature, for example
~ 15.~ water glass (in the form of sodium ~ potassium di- and
. tri- silicates), calcium sulphate dihydrate, silicates
such as magnesium silicate and aluminium silicate, boron
compounds such as borax, aluminium hydroxide, asbestos,
. and crystallinesalts which contain water of crystallisation
which is released at higher temperatures Equally good
flame-proofing is obtained with non-com.bustible inorganic
: substances which split off carbon dioxide when they ignite,
- 17 -
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105Z050
e,g. calcium carbonate (convenien~ly used as chalk) and
sodium bicarbonate, These flame-retarding components can
be introduced into the emulsion in the form of an aqueous
solution or as powdery solids,
There may also be used compounds, e.g. para-
. formaldehyde, urea, phosphates, dicyandiamide and phosphoric
acid esters of pentaerythritol, which at higher temperatures
~- (220-3000C) expand to provide flame-retarding properties,
Such flame-retarding components can additionally be applied
as lacquers or solutions for impregnating the finished
. shaped articles, whereas the other flame-retarding components
to be used according to the invention are only added to
th emulsion before hardening.
Even with small quantities of the flame-retarding
15 components mentioned above, e,g, from 5 to 2~/o by weight
based on the weight of the emulsion (i,e, the total weight
;; of the emulsion including any further ingredients),
outstanding flame-proofing has been obtained even at high
temperatures above 1000C,
: 20 The shaped articles produced according to the
invention also have the advantage that in the event of
fire they are easily extinguished.with water and scarcely
: - ' .
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- 105Z050
; distort under the action of high temperatures Such a
resistance to the effects of burning could not be predicted
since, with the same flame-retarding components in compact
non-foamed resins, no such effect is achieved.
If desired, at least part of the flame-retarding
component can be provided by a substance serving also as
- a filler, for example perlite, chalk or asbestos The
emulsions used in the process according to the invention
may also if desired contain a filler component in addition
to, or instead of, such flame-retarding components.
Fibrous and/or particulate filler materials, if desired
of coarse particle size, may be used Such materials
which have proved suitable include plastics and foams which
do not dissolve in the emulsion or do not disintegrate
through dissolution or expansion, in the form of tiny,
optionally expandable particles, hollow spheres, solid
spheres, and fillers with, optionally, larger particle
sizes, made, e g. from polyurethanes, melamine resins,
urea resins, formaldehyde resins, phenol resins, epoxy
resins, polyamides, PVC, polyvinylidene chloride, poly-
acrylonitrile and polymethacrylate, or from expanded
inorganic materials, e g., glass, clay, perlite, vermiculite,
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lOSZ050
slag and pumice
Heavy aggregates such as quartz, grit and asbestos
are~also suitable as fille~s.. Where the filler is in
the form of fibres, the mechanical properties, particularly
the rigidity, of the shaped articles produced according
~ to the invention may be substantially improved,
Flame-retarding components serving as fillers and/or
~. additional fillers may be used in combination as desired
in order to vary the density and mechanical properties,
` 10 such as rigidity under pressure and inflexibility, of the
'~ shaped articles produced according to the invention
- The fillers which can be used may be of such a
course particle size (e g 10-30mm in diameter), that the
water-in-oil emulsion, which already contains the inorganic
flame-retarding components, can fill the spaces between
¦~ the particles, while the emulsion can also contain filler
particles which are finely ground and able to slide (0 05-
2mm in diameter) In general the fillers conveniently
have a particle size from 0 05 to 30mm,
For the completion of the process according to
the invention, it is moreover advantageous to remove the
water within a short time, Investigations have shown that
~,
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,,. ,. 105Z.050
the final shrinkage measurement. in emulsion foams is
only reached when 75-85% of the water used has been removed,
A high water content in the shaped articles
produced according to the invention can affect the good
insulating effect of the porous material against heat,
and therefore also the stability of this material at
higher temperatures.
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lOSZOSO
; Emulsion water remaining in the product or escaping
very slowly indicates that the water must be diffusing
out of closed cells. This very condition, through
irregular drying, leads a) to distortion and b), under the
action of flames, to a strong tendency to crack. Openings
are caused through which the flames penetrate.
Predominantly sealed-pore materials barely absorb
any moisture after water has diffused out. In open-pored
emulsion foams the residual moisture which is advantageous
in flame-proofing can, taking into consideration the
r; humldity of the air, be put in and retained by the co-use
of hygroscopic materials and materials which contain water
~- in a phy~i~ally bound state, but which 1s given off at
high temperatures. Under the effect of heat, the steam
can escape from the open pores, without pressure building
up in them. Open-pored foams can be filled with wate~r-
during a fire or when there is danger of fire, so that
additional extinguishing and flame-proofing effects are
obtained. The water quickly dries out again afterwards
without causing any damage. Also, impregnation with
flame-retarding components can be performed.
':
~ According to the process of the invention, the shaped
;~ articles obtained have a structure such that unobstructed drying
can proceed and the water is
. .
- 22 -
lOSZOSO
not compelled to diffuse out through cell walls, i.e. a structure
which is predominantly open-celled is ensured. This can be
tested by the rapidity of the drying process itself, exactly
like testing the permeability of liquids and gases, but also
usefully, by testing the absorption speed of liquids, i.e. in
the drop-absorption test. For the shaped articles produced
according to the invention, it is therefore preferred that they
have the smallest possible water content after drying, advantageously
not more than 0-5% by volume, which amount is mostly present
because of the humidity of the air itself.
The openness of the pores of the end product produced from
a water-in-oil emulsion is controlled by suitable adjustment of
the dispersion level of the emulsion as hereinbefore explained.
This adjustment of the dispersion level is advantageously
effected by the use of emulsifying agents and by controlling
the mechanical distribution via the stirrer, by means of
its number of turns and the stirring time of the emulsion.
In this way the required openness of the pores and thus
degree of dryness in the desired time after curing is
obtained. At the same time the mechanica~ properties
dependent on the volume of the pores, the fineness of
structure, and the proportions of open and closed
. .
- 23 -
lOSZ050
cells are also ad~usted.
The required dispersion level can be ascertained
in a simple way by viscosity measurement. The viscosity of the
emulsion is related to its stability during curing, on the one
hand, and to the dehydration properties of the cured product,
on the other hand, as is disclosed in British Patent Specification
No. 145~203 (British Patent Application 53652/73).
With about six test experiments, a curve can be
ascertained from which one can clearly see the dispersion
level to which the emulsion must be adjusted in order
to dehydrate the finished shaped article in a short time
after curing.
For this, about six samples of the water-in-oil
emulsions, of increasing viscosity, which can be set by
increasing the number of turns, the stirring time or the
temperature, but also by means of the emulsifying agents, are
cured in otherwise similar starting conditions. From
these six cured samples, the weight when wet, and the de-
hydration by drying at a temperature of 23C, with
ventilation, are determined. The process can also be
shortened by determining the weight loss shortly after curing
and after the water has been suction filtered off under
reduced pressure. If the weight loss or water loss as a
- 24 -
lOSZ050
percentage is related to the viscosity, a curve results
from which the most suitable viscosity can be ascertained
for yielding, on the one hand, a sufficiently solid, and
on the other hand, a fast-drying product.
The ratio of open to closed pores can also easily
be ascertained, as mentioned above, by the speed and
quantity of the uptake of liquids (water, alcohol) in
sample articles.
It must be borne in mind that adding flame-retarding :~
components and fillers can substantially alter the nature of a :
~ .; water-in-oil emulsion. An emulsion which, after curing, - ~.
- -
~ has.. à.suf.ficient-drying speed or openness of pore~s, can
1~. lead to a virtually sealed cellular system by the-addition
.. of fillers. The`adiustm~nt ~ ~ e... di ~ersi~.a ~ ~
: therefore, to be performed, if possible,-with.théJe addit ~ .
In the following illustration the chang.es in drying
speed, depending on viscosity, are shown with the help of .
;: a graphic represent~tion. It can be clearly seen that the .
properties of the cured products are pre-determined
:; ~
` with the adjustment of the dispersion-level. . -~`
~-. . The values graphically shown in the Figure are obtained
with a water-in-oil emulsion, consisting of 45 parts by weight -
of an unsaturated polyester ca~t resin and 55 parts by weight
: of water. In the experiments the
.
- 25 -
1052050
viscosity was altered each time and the sample piece was
dehydrated by suction filtering. The water 1098, per cent,
ascertained after suction filtering was correlated with
viscosity before curing. The change in water loss, in
relation to the viscosity, is connected with the stability of
the emulsion during curing. The openness of the pores can
be adjusted via the dispersion level, as can clearly be seen,
and as described in British Patent Specification No. 1458203
(British Patent Application 53652/73). The dispersion level
is set at a favourable drying range between 1500 and 200cP,
since, in this range, the mechanical values increase again.
The shaped articles manufactured according to the new
process attain, at low densities (from about 0.15 g/cm3), flame
,
resistance and mechanical properties which would not have been
at all expected.
Thus, for example, a 4 cm thick~ sheet, produced
according to the invention, and made from an emulsion with
a water content of 60%, a styrene-modified polyester
resin and 34% by volume of expanded glass (1-5mm particle
size), has a density after drying of 0.38. In a-comparison -
test with a corresponding material made, according to a
previously-known process, from expanded polystyrene and cement,
and a material made from polyester foam and expanded glass,
.:
- 26 -
lOSZ050
the following solidity values result:
Material Density Rigidity Infle~ibility Heat-con-
g/c cm under2pressure kp/cm ductivity
; kp/cm number
Foamed poly- 0.3 3 2 0.1
styrene/cement 0.5 15 4 0.15
Foamed poly-
ester/expanded
glass 0.37 32.5 - 0.6
Emulsion foam/
expanded glass 0;37 60 30 0.047
. ~
When the previously-mentioned emulsion foam sheet,
placed vertically, is directly exposed ~o flames from a butane
burner, which produces a temperature of 1600G on the upper
.
surface of the sheet, a temperature of 140C is not measured with
a thermocouple element on the back of the sheet until-after 55
minutes. It should here be pointed out that the flllers used
for economical reasons favour heat conduction, but to the not
inconsiderable detriment of flame-proofing.
It is believed that the favourable results of the emulsion
foam produced according to the invention must obviously be explained
by the fact that owing~to th~ s~ructural fineness of the cured
emulsion, with the escape of water an excelleht temperature
insulation is obtained, which scarcely changes, even at higher
temperatures.
- .
2-7 -
105ZOSO
The slight alteration of the heat conduction number
(kcal/m.h. C) as the temperature rises can be seen from
the following Table:
0C 20C 60C
Emulsion foam without 0.047 0.048 0.049
filler, density 0.3
Emulsion foam with filler 0.0475 0.0485 0.05
(expanded mineral),
Resin : filler = 1 : 1,
Density 0.35
~ .
Thus it can be seen that the alteration in the heat con-
duction number is smaller than is known for conventional
. insulation foams, such as those made from polystyrene, for
example.
~- For a better characterisation of the properties under the
- effects of flames, comparative experiments are subsequently
~, ` . -:
performed, in which the flame-retarding components to be
used according to the invention are added to compact resins
and emulsion foams. As has already been mentioned, the
proportion of open cells in the cured product is pre-
determined, in performing the process of the invention by
~ , ~
adjusting the dispersion level, and the presence of a maj~r
proportion of open cells makes it possible for 75-85X of the
water introduced with the emulsion to be removed, without complications,
in
, . . .
- 28 -
1052050
the shortest possible time. Thus the open cellular
structure which is obviously necessary for flame-proofing
the products according to the invention is obtained and, in
the shaped article produced according to the invention, the
adjustment of the residual water to a quantity of preferably
between 0 and 5%, to a maximum of 14% calculated on the volume,
is possible taking into account the air humidity and the
addition of hygroscopic materials and additives which contain
physically bound water.
The advantageous residual water content varies
according to the density and combustibility of the materials
and the filler content. It is of advanta~ge if, in performing
the process of the invention, one takes into account the
emulsifying agents and procedures which lead to open-pored foams
and which are described in U.S. Reissue~Patent 27,444,- U.S. Patent
3,734,867 and in Belgian Patents 785,091 and 74I,308.
In these publications, however, the procedures which
lead to a small w~ter residue in the dried product are not given.
In the following investigations, therefore, the adjustment of the
small water content in the end product is first undertaken via the
dispersion level, using three recipes for emulsion foams as
starting materials.
; In the following table (in which all proportions are by
- weight unless otherwise stated) the composition of the formula
, ~ .
- 29 -
;
1052050
for the emulsion foams is stated, and, with the given viscosity,
the value is ascertained which guarantees a corresponding
dehydration and openness of the pores of the product
containing the introduced flame-retarding components.
The composition of the samples varies only in the
~ quantity of water added to the emulsion, in the viscosity,
ç and the various flame-retarding components tested in the burning
test. The preparation of the samples is performed in known
manner. The polymerisable portions of the formula and the
~- additive which is soluble in them - without accelerators -
are added, with water, to the water-in-oil emulsion. The
flame-retarding component is added to the complete water-in-cil
emulsion, to the water, or to the resin as desired and
finally the peroxide catalyst and the fillers are stirred~in.
The emulsion is poured into a 7 x 7 x 3 cm
polyethylene container and cured. Before the casting is
removed, the weight when wet is determined and the sample
is dried at 23 C until it reaches a constant weight. The
residual water content is determined and the burning test
is performed. In the burning test (see Table 2) the sample
is clamped Ln a vertical position and exposed to a butane
1 burner flame at right angles producing a temperature of
1600C in the light blue centre of the flame. The centre
flame at 1600C is directed onto~the surface of the
., ' .
- 30 -
10 5Z~D5~D
experimental body in such a way that, at this spot, a
temperature of approx. 1600C occurs over a surface of
about 15-20 mm in diameter. On the back of the sample
part, in a borehole set at a distance of 10 mm from the
centre of the flame, the temperature is followed for a period
of 5 minutes, by means of a thermocouple element. In addition,
after removal of the charred parts, the depth in the centre
of the burnt-out depression caused by burning is measured.
'
~ .
, ,
.~ ' .
. . .
. .
- 31 -
:''' '
~ C 1'- tT~ r/~v~ C- rr~ ) i~ 1~ rt D O ~ ~ , . ~1 ~ t'~ ~ :'
~-r ,-. ~ 3 ~ ~ ~,rt 1-~ 0 3 rt I-h 1~ rD O O ~D X pJ
r '' rn 01-- O ' ~ ~t~ 3 ~ c 3~ r ~ c~ tt ~ o ~ rn '~:1 ~_ .
, rrn ~ ~ ~t ~t ~ U) r~ ~_ rD O 3 tD ~ I~ ~D ..
0~rt~t ~tO p~ It rt 't p) N ~ rn rn 3 O ;;
rt . 3 3~:: rD t It ~ O Z
~.... r, r~ o ~ ~ ~ rD ~ X O ~.
.~ 3 ~ C rt ~t Q ~t X ~ .
ID ~t ID ID 0~ rj
_ ~ _~_ _. _ l rt _
I_ O rJI O I_ . . r ~, O O O O D r ~ I--
_ _ _ _ _ __ .,
~ IJI O I~ Ir~ I~) ~_ (~ ,0 ~ ~O- rt~ ~ ~ t~
.` ~1 O ~o O rJ~ O _ O ~ O r-~ _ O
Or ~ Ul ~) ~_ ~ .0 ~A) I~ ~ 00 C ~ r~
_ o r,~ o ~n __ o _ o o D o ~_ ~ ,.
~n g ~ O t~ X X X X X X X X ~ ~ ,
~ _ _ ~ __ .. _ _ _ . ~
rJ~ 8 ~ o o x x x x x x x x rJI :;
. _ ~- . _ _ __ _ _ ,~
~ g ~ o g X X X X X X X X .,~
' ' _ ~ _ ~ _ _ _ _ _ _ ~
`.' ~n 0 ~ O g X X X X X X X X ~I ~
rJ~ CO _ ~ _ _ _ _ _ _ , ,~ ,
~n O ~ O ~ X X _ _X X X X _ ~t
a~ X X X X X X- ' X X X X X X ~
,', J
' 1
-- 3 2
' `.
-~ 10 5Z~DS~D
In Table 1, the abbreviations, explained as follows,
are used In this explanation, the percentages referred
to are by weight:
UP = Unsaturated l Commercial product made from
polyester resins maleic and phthalic acid
anhydride and propylene glycol;
styrene content 35%, viscos~ty
650-lO0 cP at 20C, acid number
below 30 = U P 1
2. Commercial polyester ca~ resin
based on HET acid;
; Type lllO according to DIN 14946,
chlorine content 27%, maximum
acid number 30, styrene content-
25% = U P 2
Monomers 1. Styrene = St
.~ 2 Methyl methacrylate = M M A
Peroxides 1. 50% Benzoyl peroxide = B P -
-
Accelerator 1, 50% Dimethyl-p-toluidine - D M T
Inhibitor 1 "C 10" (Manufacturer Ak~d Chemie
GmbH)
~ Emulsifier 1 Pluronic 123 (Manufacturer
;~ Wyandott;"Pluronic" is a
` registered Trade Mark):
. Condensation product made from
.~ propylene and ethylene-glycol = -
P 123
In Table l, the symbol "X" indicates that the
figure is the same as that given for the immediately
~ preceding experiment,
`: .
,
: ` - 33 -
.
.,,
.
l os~ oso
~ ~1 1~ ~ U~ ~ Ln 1 ~rl O O L C ~ _I
_ __ _ ........... _ _ _ _ . _ _
O Ln Ln Ln ~D ~ X I~ ~ L ~) _I .
_ __ I_ _ _ __
r--I L~') t~ ) C`J L ~ Ln L
. ~1 ~ _ _ Ln 1~ _ X _ _ _ __ _ _ L~
~, O ~ CO ~ ~ ~`I ~; O O ~1 C~l n
C~ N ~ `;t ~D co ~ V ~1 1~ ~ a~ _ ___
_ _ _ _ ~ _
~I ~ Ln O L . ~ ~ ~ Lt~ n ~I
--__ __ _ 0~ V _ _
~ ~ Ln Ln Ln _l O c~l I~ O c~l ~D
0~:> ~ ~ L~l ~0 1~ ~D~d L ~ ~ C`l _I _I .
, I _ __ _ _ _
. Ln I~ ~r) ~I r~ L~,~ 1 ~ --I L~O~ Ln O
. I~ . ~ Ln I~ 00 CO ~ ~ ~n t~ N C~ C~l
. O O CO I~ O _ _ ~ =~, _ _
O ~ Ln ~ I_ co . ~ 1~ ~ t`J u~l Lcn ~D ':t
. ._ _ _
Ln ~ o l l l x uJ o~ o Lcno n o
: ~ -- CO ------ -- N ~ _ _
A
. ,,~ ~ _ o o __ X _ ~ ~ _ o o C~ o
D _ ___ . K _ l l _ ul ~ co ~ ~ .
:. ~ m _ _ _ _ . ~ ~ :~ 3
.~ ~ n I ~ ~ ~ ~a ~
~ o ~ ~ o ~ o ~
o ~- ~:: h h ~ E E ~: ~
O o~ ~ ~ ~ ~ ~ ~ ~3
- æ ~ 0 E . ~ ~ "~ h h O 1~ 0 O 1- O
o _I ~ ,~ ul ~5 13 o) .s~ ~0 ~ 5' h ~ ~
~ ~ ~ ~ ~ cJ O 11 ~ ~ .. 1 ~> ~r~ V ~ _ U~
E~ ~ E~ ~ ~ ~ ~ X ~ ~ ~ 3 ;i: ~ ~ ~ ~3; 3 ~ 3 ~
~ ~ 3
., i
,
.
1 052 50
? -.
.
_ _ _ _ . _ O _ D _ _ ~
. ~ e ~ ~ sr~ ~ ~ o ~o ~ ~ :~ ~ O ~ O o ~ ~O .-
~"~ X-- ------ I_ _, _ _ , '.
~ ~`J u~ u~ O u~ ~ ~? X ~ c~l o o O O O
_ O _ _ _ _ I~ . _ ~ .~ _ ~
i ` ~ -1 ~`I ~ ~ 1~ 4~ _ . _ ; .~ .
~`~ t _ __ _ _ . _ _
_ . x o . o '`
.,.""`~ , ~ ~ ~ u~ OD ~D ~ C~l Oo ~0 0~ U~
- - . - ~ - ~ -
~D U~ u~ O u~ ' ~ 'c~O~' O u~ u~ a)' ~'
L: ,~ _~ ~7 u~ ~D I~ I~ ~ ~ 'V r. ~D o~ u~
- ~, _ _ _ K __ _
O ~0 U~ U~ Ul ~D : ,~ ~ N O C~ 1~ ~
,' ,l~ l _ _. I X ~ ___ __ __ , .:
" ~ ~) ~ ~ V~ O --l 1- O ~ N ,0 Ir~
_ _ _ __.__ _ ~ ~ :~ ~ .,
. '` _ _ ~ _ - ~U "a ~0 ~ ~:) 3
O(~J ~ ~ ~ ~ ~ 3
':''` o~01 :1 ~ -01 ~0 0 ~J-
.n . o ~ ~1 o 0 h ~ ~: ~ 6 ~:: .
. ~bO a) o. ~ ~ ~1 ~1.~ ,. -
. .~ O ~ .~ v ~ ~ ~ 0~ 0 ~ X~ ~ ~ ~ O ~
....'. N ~ ~ ~ ~ ~ ,s: ~1 ~ ,1 as ~J ~1 0 ~ J.~
.~ . O ~ 0 .~ 0 0 V O ~ h ~ ~1 ~ ~1 ~ .o
O t V ~ ~ ~1 O Cl O O J- O ~ O ~ .,~
Z 0 al o o ~ h ~ ~ ~1 ~ h ~ ~ 3
. . ~J ~S 1~ ,1 ~ O ~ V V 3 V V ~ 3 V h
-. ,0 ,1 e 0 : . v h 1~ 80 c v ~ ~ ~r~ V ~ ~
. ~ , 0 Q~ V ~J h ~ ~1 O W Cs ~ 5: O ~- Ql ,1: ,C <D
. . ~ u~ . . ~ . v x -.- ~ ~ ~ ~u 3 3 3 3 nJ ~'Z 3 S~ 3 p~
. ~ _35_
,.- ,~ . ~. .
.~. , '.
. . .
. . . . .
... . . - .
^~
- 10 5Z~D5~D
sThe following observations apply to the experiments
(i.e. example referred to in the preceding Tables 1 and 2.
Examples l - 5 are for purposes of comparison; Examples
6 - 19 illustrate the invention :-
Example 1
The sample contains no flame-retarding substance of
any kind. The sample begins to burn all over immediately
after the fl~me has been applied, and after only 1 minute
a hole 3.5 cm wide has been burnt through the sample. The
experiment is interrupted. The sample has lost three
quarters of its weight.
~.' :
Example 2
- The sample was produced with a chlorinated commercial
polyester resin, chlorine-paraffin content 20%, with the
addition of 5% of antimony trioxide. After a little over
2 minutes the sample is burnt through.
Example 3-5
The behaviour of the materials using fillers-of coarse
particle size is demonstrated, namely-expanded c~ay (diameter
2-3 mm) quartz ~diameter 2-3 mm) and boron silicate glass
(diameter 1 mm).
~ .
. i ... .
~ - 36 -
,: . :
.
:
.
... ..
'' iOSZ050
These samples are not satisfactory either, since
they start to burn over the whole surface, and after a
short time the maximum temperature of 100C is attained
on the back.
A clear improvement, however, was then obtained
with perlite and chalk, whereby, for perlite, a mixture of
very fine parts, of particle diameter approx. 40~, and
` coarser parts up to 2 mm in diameter, was used.
:
Examples 3-8 ~ -
- Received the additives under the following
considerations. It is taken as a premise that, in flame- -
proofing, the ratio of distribution of the flame-retarding ~;
materials and the combustible substances is-of importance. ~ ;
I The additions in the aforementioned Examples 3-8 ~-
~, were therefore made in proportions by volume, namely,
~t for each part by volume of emulsion, two parts by volume ~ ~ -
of filler were added. The samples 3-5, with coarse fillers, ~`~
immediately began to burn over their whole surface, and on
the back, a temperature of 100C was reached after a short
; time.
The samples 6, 7 and 8, provided with finer fillers,
- namely perlite and chalk, are clearly distinguished from
them.
- 37 -
'
lOSZ050
Here, a significantly more effective flame-prooflng
can already be ascertained. The mixture of fine and coarser-
particled perlite already fulfills the conditions necessary
for the performance of the process, and so does the chalk.
In Examples 9-13, the flame-proofing qualities of
various silicates and borax is proved. It is shown that the
temperature measured on the back rises slowly and moderately.
The depth of the burnt-out depression is between 5 and 9 mm.
Over the burnt centre, spreads a more or less solid
insulating layer, which, after removal, reveals the undamaged
state of the material which was treated with the flame.
Examples 14-17 are performed with increasing concentrations
of flame-retarding agents and increased pore volumes, and it
is shown that flame proofing does not diminish, even with
lower densities if anything, it increases. In Examples
18 and 19, the fl~me resistance of 4 cm thick sheets io
tested, which sheets were produced from an emulsion with - -
55% water and unsaturated polyester cast resin, using a ~ ~ -
silicate mixture (Example 18) and aluminium hydroxide
(Example 19) and expanded glass (particle diameter 20-30 mm),
The volume ratio of filler to emulsion? provided with flame-
proofing agents, is 1 : 2. Example 19 has already been
reported in more detail in the preceding description.
,
i - 38 -
~ .
10 5Z OS~D
In both Examples 18 and 1~, a temperature of 140C,
at a distance of 4 cm from the maximum temperature on the
other side, is not measured until after 55-58 minutes.
At the same time, this maximum temperature on the back,
after a period of 55-58 minutes, is confined to
the direct action of the burner on a circle of about 25 mm
in diameter. In the surrounding area the temperature
quickly falls to 60 - 70C, and reaches approx. 30C on the
back at a distance of 6 cm from the burnt centre. The
article is unaffected apart from the area of the direct
effect of flames from the burner, The depth of the burnt
out depression is 35 mm. In Example 19, the flame came
through to the back after 60 minutes, whereas, in Example 18,~
the back remained completely undamaged.
For reducing inflammability per se, the same
agents can be used in a higher concentration, while this can
be restricted to particular parts or surfaces. In addltion
to additional impregnation of the surface, inflammabiIity
can be checked by a higher concentration of the flame~
retarding agents in the surface, or a subsequent coating.
At the same time, water-blnding drying agents can also be
put to use, to advantage, e.g. by the addition of small
quantities of hygroscopic salts such as calcium chloride,
lithium chloride, glycerol, alcohols, glycols,
1~5ZOSO
carbohydrates, cellulo~es, and substances which become enriched
with water, by means of the humidity in the air. The slight
water concentration resulting therefrom has hardly any effect~
or no effect at all, on the insulating and drying properties
of the material. The moisture content can be very accurately
adjusted, and a maximum can be maintained even at a low average
humidity of 25-30%.
According to the process according to the invention,
shaped articles with a cellular structure, the pore w lumes
.. . .
of which are 25-85% by volume and the pores of which are
predominantly open, may be obtained. By means of appropriate
shaping, all the structural engineering parts which are used -
in building can be produced according to the proce`ss of the
invention. Thus it is possible for example to manufacture~
according to the process of the invention, the shaped parts
which are necessary for erecting walls, such as for example,
wall slabs, tile-shaped members of all shapes and sizes~ wall-
covering elements, supports, carriers, reinforcements,
door and window frames, door panels and the likeO Similarly~
there may be produced, formworks for constructional purposes,
individual formwork members, formwork stones and support members
which are for example reinforced with glass fibre. Bases for
oil and water tanks, and for bathtubs and similar apparatus~
-- 40 --
~0 5Z~S~D
can also be produced according to the process of the invention.
Moreover it is possible to manufacture pipe lagging, insulation
layers and whole insulation walls or insulated shaped parts
according to the process of the invention.
However~ furniture, furniture parts, internal
furnishings of homes, such as, for example, panel~, boards~
picture frames, and devices for hanging curtains, can be made
according to the process of the invention. The process
according to the invention also makes it possible to produce
moulded parts which can be used, in all kinds of applications~
for fitting out large areas, as parts for industrial manufacture~
such as, for example, housing, temporary accommodation, and roof
coverings. ~ `
Since the shaped articles of the invention, produced
according to the process of the invention, prove practically
non-combustible when flames are applied to them~ these shaped
parts c~n also be used as so-called fireproof partitions or
walls, and as fireproof doors.
The shaped articles according to the invention also
have the considerable advantage that they are extensively
resist~nt to weathering and are not subject to rotting.
By their relatively high pore volume and their low content
of free water, the shaped article~ produced according to the
invention are very light and show virtually no shrinkage,
- 41 -
105Z050
t compared with a porous shaped article the pores of which are
completely full of water. The shaped articles according to the
invention can rather be designated decidedly stable in form.
Even in the extreme conditions of an electric storm the
shaped articles according to the invention keep their shape
. over a fairly long periodO
.
.: ~
' ;' ~' ' '
.
:; - 42 _
