U.S. patent application number 12/445108 was filed with the patent office on 2010-04-15 for silicone foam control agent.
Invention is credited to Delphine Davio, Alain Hilberer, Jacqueline L'Hostis, Jean-Paul H. Lecomte, Andreas Stammer, Nicolas Ziolkowski.
Application Number | 20100093598 12/445108 |
Document ID | / |
Family ID | 38962825 |
Filed Date | 2010-04-15 |
United States Patent
Application |
20100093598 |
Kind Code |
A1 |
Davio; Delphine ; et
al. |
April 15, 2010 |
Silicone Foam Control Agent
Abstract
A method of making silicone-based foam control agents
comprising: i) preparing a polysiloxane containing polymer by the
polymerisation of siloxane containing monomers and/or oligomers in
the presence of an inert organopolysiloxane and/or an organic
fluid, a suitable catalyst and optionally an end-blocking agent;
ii) where required quenching the polymerisation process; wherein
the inert organopolysiloxane and/or organic fluid is substantially
retained within the resulting diluted polysiloxane containing
polymer; iii) introducing from 0.1 to 10% by weight of a suitable
filler prior to during or subsequent to step (i); iv) optionally
introducing up to 5% by weight of a suitable silicone resin during
or subsequent to step (i) and v) where required, adapting the foam
control agent produced in steps (i) to (iv) into a suitable form of
delivery therefor.
Inventors: |
Davio; Delphine; (Le Roeulx,
BE) ; Hilberer; Alain; (Recquignies, FR) ;
L'Hostis; Jacqueline; (Silly, BE) ; Lecomte;
Jean-Paul H.; (Brussels, BE) ; Stammer; Andreas;
(Pont-a-Celles, BE) ; Ziolkowski; Nicolas;
(Brussels, BE) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS PLLC
450 West Fourth Street
Royal Oak
MI
48067
US
|
Family ID: |
38962825 |
Appl. No.: |
12/445108 |
Filed: |
October 9, 2007 |
PCT Filed: |
October 9, 2007 |
PCT NO: |
PCT/EP07/08753 |
371 Date: |
December 23, 2009 |
Current U.S.
Class: |
510/466 ;
524/186; 524/268; 524/284; 524/405; 524/417; 524/423; 524/424;
524/430; 524/432; 524/433; 524/444; 524/500 |
Current CPC
Class: |
C08J 2383/04 20130101;
D06M 15/643 20130101; A61K 8/062 20130101; C10M 2229/0405 20130101;
C10M 173/02 20130101; C10M 2229/041 20130101; A61Q 19/10 20130101;
A61Q 5/12 20130101; A61K 8/068 20130101; A61Q 19/00 20130101; A61Q
5/02 20130101; C10M 2229/043 20130101; C10M 2229/0415 20130101;
C10M 2229/045 20130101; C10M 155/02 20130101; C10M 2229/04
20130101; C10M 2229/0435 20130101; C10M 107/50 20130101; A61Q 1/10
20130101; A61K 8/891 20130101; C11D 3/373 20130101; C10M 2229/0455
20130101; C08J 3/03 20130101 |
Class at
Publication: |
510/466 ;
524/500; 524/268; 524/430; 524/444; 524/432; 524/433; 524/284;
524/186; 524/417; 524/423; 524/405; 524/424 |
International
Class: |
C11D 3/37 20060101
C11D003/37; C08G 18/42 20060101 C08G018/42; C08K 5/54 20060101
C08K005/54; C08K 3/22 20060101 C08K003/22; C08K 3/34 20060101
C08K003/34; C08K 5/09 20060101 C08K005/09; C08K 5/17 20060101
C08K005/17; C08K 3/32 20060101 C08K003/32; C08K 3/30 20060101
C08K003/30; C08K 3/38 20060101 C08K003/38; C08K 3/26 20060101
C08K003/26 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2006 |
US |
60828864 |
Claims
1. A method of making a silicone-based foam control agent
comprising (i) preparing a polysiloxane containing polymer by the
polymerisation of siloxane containing monomers and/or oligomers in
the presence of an inert organopolysiloxane and/or an organic
fluid, a suitable catalyst and optionally an end-blocking agent;
(ii) where required, quenching the polymerisation process; wherein
the inert organopolysiloxane and/or an organic fluid, is
substantially retained within the resulting diluted polysiloxane
containing polymer; (iii) introducing from 0.1 to 10% by weight of
a filler prior to, during, or subsequent to step (i); (iv)
optionally introducing up to 5% by weight of a silicone resin
during or subsequent to step (i); and (v) where required, adapting
the foam control agent produced in steps (i) to (iv) into a
suitable form of delivery therefor.
2. A method according to claim 1 characterised in that the inert
fluid is an organic extender and/or plasticizer
3. A method according to claim 1 characterised in that the inert
fluid is an organopolysiloxane which does not react with cyclic
siloxane having from 2 to 20 silicon atoms.
4. A method according to claim 1 characterised in that the inert
fluid is a trialkylsilyl terminated polydialkylsiloxane having a
viscosity of from 0.65 to 10000 mPas at 25.degree. C.
5. A method according to claim 1 characterised in that the
polysiloxane containing polymer is prepared via a polymerisation
process selected from the group of polycondensation, chain
extension, polyaddition, and ring opening.
6. A method according to claim 5 characterised in that the
polysiloxane containing polymer is prepared via a polycondensation
reaction with dodecylbenzenesulphonic acid as the catalyst.
7. A method according to claim 1 characterised in that the
polysiloxane containing polymer is of the following general formula
R.sub.(3-a)R.sup.1.sub.aSiO[(R.sub.2SiO).sub.b(RR.sup.1SiO).sub.c]SiR.sub-
.(3-a)R.sup.1.sub.a (1) wherein each R is the same or different and
is an alkyl group containing 1 to 8 carbon atoms, a substituted
alkyl group containing 1 to 6 carbon atoms, or a phenyl group;
R.sup.1 is a hydroxy group, a hydrolysable group, or an unsaturated
organic group; a is zero or 1, b is an integer, and c is zero or an
integer, and the sum of b+c is equal to a value of at least
200.
8. A method in accordance with claim 7 characterised in that the
sum of b+c is equal to a value of at least 1500.
9. A method according to claim 1 characterised in that the silicone
resin is a non-linear silicone comprising siloxane units of the
formula R'.sub.aSiO.sub.4-a/2 wherein R' denotes a hydroxyl,
hydrocarbon, or hydrocarbonoxy group, and wherein .alpha. has an
average value of from 0.5 to 2.4.
10. A method according to claim 9 characterised in that the
silicone resin is a siloxane resin comprising monovalent
trihydrocarbonsiloxy (M) groups of the formula R''.sub.3SiO.sub.1/2
and tetrafunctional (Q) groups SiO.sub.4/2 wherein R'' denotes a
monovalent alkyl group and the number ratio of M groups to Q groups
is in the range 0.4:1 to 1.1:1.
11. A method according to claim 1 wherein the foam control agent is
prepared in the form of an oil-in-water emulsion utilising the
following additional steps: (V) if required, introducing one or
more surfactants into the polysiloxane containing polymer to form a
homogenous oil phase; (VI) adding water to the homogenous oil phase
to form a water-in-oil emulsion, the water being added in an amount
of 0.1-10 percent by weight based on total oil phase weight; (VII)
applying shear to the water-in-oil emulsion to cause inversion of
the water-in-oil emulsion to an oil-in-water emulsion; and
optionally (VIII) diluting the oil-in-water emulsion by adding more
water.
12. A method according to claim 1 wherein the foam control agent is
prepared in the form of an water-dispersible foam control
composition by dispersing the foam control agent in a
water-dispersible carrier.
13. A method according to claim 1 wherein the foam control agent is
prepared in the form of a granulated foam control agent by
involving the foam control agent in one or more of the following
methods granulation, spray drying, emulsification followed by
drying, spray mixing, spray chilling, compacting, extrusion, high
shear mixing, low shear mixing, and flaking.
14. A method in accordance with claim 13 characterised in that the
granulated foam control agent is supported on a particulate
carrier.
15. A method according to claim 14 characterized in that a
water-soluble or water-dispersible binder is deposited on the
particulate carrier.
16. A method according to claim 1 characterised in that the filler
is a hydrophobic filler selected from the group of silica, titania,
ground quartz, alumina, aluminosilicates, polyethylene waxes,
microcrystalline waxes, zinc oxide, magnesium oxide, salts of
aliphatic carboxylic acids, cyclohexylamine, alkyl amides, and
SiO.sub.2.
17. A method according to claim 16 characterised in that the filler
is a silica filler with an average particle size of from 0.5 to 30
.mu.m.
18. A method according to claim 1 characterised in that the
silicone resin is present at 2 to 30% by weight based on
polysiloxane containing polymer.
18. (canceled)
19. A water-dispersible foam control composition comprising a foam
control agent according to claim 1 dispersed in a water-dispersible
carrier.
20. A foam control agent in particulate form obtained in accordance
with the method of claim 13.
21. A foam control agent according to claim 20 characterised in
that the particulate foam control agent additionally comprises a
binder or encapsulant, and a carrier or support.
22. A foam control agent according to claim 21 characterised in
that the binder is a polyoxyalkylene polymer, a polycarboxylate
polymer, or a cellulose ether.
23. A foam control agent according to claim 21 characterised in
that the binder is an organic compound having a melting point of
from about 40 to 80.degree. C. and which in its liquid form is
miscible with the polysiloxane containing polymer so as to form a
homogeneous liquid which upon cooling forms a monophasic wax-like
substance.
24. A foam control agent according to claim 21 characterised in
that the carrier is a zeolite, sodium tripolyphosphate, sodium
sulphate, sodium perborate, or sodium carbonate.
25. A foam control agent in the form of a water-dispersible foam
control composition obtained in accordance with the method of claim
12.
26. A foam control agent in the form of an oil-in-water emulsion
obtained in accordance with the method of claim 11.
27. A detergent composition comprising 0.01 to 5% by weight of a
foam control agent according to claim 1 based on the weight of the
detergent composition.
28. A foam control agent according to claim 1, provided in the form
of an oil-in-water emulsion.
Description
[0001] This invention is concerned with silicone-based foam control
agents, particularly for use in aqueous compositions, preferably
detergent compositions.
[0002] In many aqueous systems which are used e.g. in food
processes, textile dying, paper production, sewage treatment and
cleaning applications, surface active agents are present either as
an unwanted ingredient or as deliberately introduced materials to
achieve a certain function. Due to the presence of these surface
active agents foam is often generated. In certain applications,
such as in dish washing by hand, this is a welcome effect but in
other applications foam generation can lead to unsatisfactory
results. This is for example the case in the dyeing of textiles or
in the manufacture of paper. In other applications, for example the
use of detergent compositions for domestic laundering, the
production of foam needs to be controlled rather than avoided. It
is important to keep the foam formation to an acceptable level when
laundering is performed in automatic washing machines, especially
front loading machines. Excessive foam would cause overflow of the
washing liquor onto the floor as well as reduction in the
efficiency of the laundering operation itself.
[0003] Silicone-based foam control agents are known and have been
incorporated into, for example, heavy duty detergent powders and
liquids for use in automatic washing machines. Silicone foam
control agents are regarded as very effective in this application
as they can be added in very small quantities and are not affected
by e.g. the hardness of water, while traditional foam control
compositions, such as soaps, require a certain water hardness for
their effectiveness. However, they are usually not cheap, and there
is a need to find ways to cheapen such formulations without
compromising the cost-efficiency of the foam control agents.
[0004] In addition, the detergent industry is constantly going
through an evolution where, due to environmental concerns, energy
conservation efforts, machine design changes, water conservation
and changing laundering habits there is a move towards the use of
detergent compositions which will perform to a higher efficiency
than hitherto. There is a need to control foam from e.g. increased
surfactant levels in the detergent compositions, use of surfactants
which have a higher foam profile than traditional surfactants and
changing laundering conditions. Since silicone foam control agents
do not directly contribute to the cleaning power of a detergent
composition it is desirable to keep the addition level of such foam
control agents to a minimum. There has therefore arisen a need to
develop improved foam control agents for incorporation into
detergent compositions.
[0005] Silicone foam control agents are mostly based on
organopolysiloxane materials, which may be linear or branched, and
which may contain a variety of silicon-bonded substituents. As the
market for these products has developed the antifoams available
have become increasingly complex and difficult and expensive to
produce. The polymers used can be extremely expensive to produce
because of the complex side chain technology required. EP 217501
describes a foam control agent wherein a liquid siloxane component
is obtained by blending two pre-prepared polymers:--
100 parts by weight of a polydiorganosiloxane having
triorganosiloxane end-groups and a viscosity of from
3.times.10.sup.-4 m.sup.2/s to 6.times.10.sup.-2 m.sup.2/s at
25.degree. C., and 10 to 125 parts of a polydiorganosiloxane having
at least one terminal silanol group and at least 40 silicon atoms;
with 0.5 to 10 parts of an organopolysiloxane resin comprising
monofunctional and tetrafunctional siloxane units in a ratio of
from 0.5:1 to 1.2:1 and having at least one silanol group per
molecule and heating the resultant mixture, optionally in the
presence of a suitable condensation or equilibration reaction type
catalyst. The post heated mixture has a viscosity in the range of
1.times.10.sup.-2 m.sup.2/s to 3.times.10.sup.-2 m.sup.2/s at
25.degree. C. The specification describes the need to control the
amount of resin used in order to retain a liquid polymer, avoiding
a gel structure. This indicates that some branching occurs in the
siloxane component of the foam control agent.
[0006] U.S. Pat. No. 3,691,091 discloses a silicone emulsion for
defoaming aqueous liquids, in which the silicone consists
essentially of a polydimethylsiloxane fluid, silica, and an
organosilicon compound or oligomer containing alkoxy and/or silanol
groups.
[0007] EP0163541 describes a method for the preparation of a
silicone defoamer by reacting a mixture of components including a
pre-prepared polyorganosiloxane polymer bearing one or more
hydroxyl and/or hydrocarbonoxy groups, a silicone resin, a filler,
a catalyst to promote reaction. Optionally the composition can
contain an organopolysiloxane free of reactive groups.
[0008] EP 0273448 describes a process for preparing a foam
suppressant composition by reacting an organopolysiloxane together
with amorphous silica and a free radical initiator catalyst and
optionally a vinyl monomer and/or a vinyl modified
polyorganosiloxane under conditions and for a time sufficient such
that free radical polymerisation occurs and a polymerisation
product forms. In this invention it is essential that the resulting
product is diluted with sufficient quantities of a
polydiorganosiloxane having a viscosity of 10 to 300 cSt such that
the final composition has a viscosity of 100 to 10,000 cSt.
[0009] GB 2257709 describes a foam control agent which is
particularly useful when incorporated in detergent compositions
where a high level of high foaming surfactants is present, and
comprises a branched polydiorganosiloxane which is prepared through
hydrosilylation of a vinyl end-blocked polydiorganosiloxane having
a viscosity of from 200 to 100 000 mPas at 25.degree. C., a
volatile low viscosity organohydrogensiloxane having at least 3
Si--H groups and a solvent in the presence of a noble metal
catalyst. The solvent used was preferably a polydiorganosiloxane
and was mainly present to solubilise the branched
polydiorganosiloxane product.
[0010] GB 1224026 describes an antifoaming agent which is composed
of 10 parts by weight of certain water-insoluble organic liquids
and from 0.1 to 5.0 parts by weight of an organopolysiloxane which
is compatible in the organic liquid and consists essentially of
monovalent and tetravalent siloxane units. U.S. Pat. No. 3,666,681
describes an antifoaming agent for aqueous systems consisting
essentially of a mixture of 100 parts by weight of certain
water-insoluble organic liquids, from 0.5 to 10.0 parts by weight
of an organopolysiloxane, which may be a fluid or a resinous
compound, and from 0.5 to 10.0 parts by weight of a filler which is
selected from finely divided silica and methylsilsesquioxane gel,
and from 0.002 to 5.0 parts by weight of a compound which is
selected from ammonia, a disilazane and an alkali or alkaline earth
metal hydroxide.
[0011] EP1075863 describes a foam control agent according to the
invention comprises (A) a pre-prepared organopolysiloxane polymeric
material having at least one silicon-bonded substituent of the
formula X-Ph, wherein X denotes a divalent aliphatic hydrocarbon
group and Ph denotes an aromatic group, (B) a water-insoluble
organic fluid, (C) an organosilicon resin and (D) a hydrophobic
filler.
[0012] U.S. Pat. No. 4,690,713 describes an antifoam composition
comprising (a) either a hydrocarbon oil or a pre-prepared
polydimethylsiloxane polymer, (b) an organosilane, (c) silica
filler, and (d) a suitable catalyst.
[0013] U.S. Pat. No. 5,777,059 describes a silicone composition by
reacting (i) a polyisobutylene compound, (ii) a pre-prepared
polyorganosiloxane polymer, (iii) an organosilane or silicone
resin, (iv) a suitable catalyst and optionally a silica filler. The
mixture is blended and then reacted at room temperature or with
heat.
[0014] WO2005/058454 and WO2005/058455 describe foam control
compositions comprising a liquid polymer of an unsaturated
hydrocarbon, a branched silicone resin and a particulate filler
which is insoluble in the liquid hydrocarbon polymer. WO2005/058455
further comprises a non polar organic material having a melting
point of 35 to 100.degree. C. which is miscible with the organic
liquid.
[0015] The high cost of producing antifoam materials can now be
avoided by way of their preparation using the following process
which produces satisfactory antifoam materials at a fraction of the
cost of many manufacturing processes currently used.
[0016] The invention is directed to a method of making
silicone-based foam control agents comprising [0017] i) Preparing a
polysiloxane containing polymer by the polymerisation of siloxane
containing monomers and/or oligomers in the presence of an inert
organopolysiloxane and/or an organic fluid, a suitable catalyst and
optionally an end-blocking agent; [0018] ii) Where required
quenching the polymerisation process; wherein the inert
organopolysiloxane and/or organic fluid, is substantially retained
within the resulting diluted polysiloxane containing polymer [0019]
iii) introducing from 0.1 to 10% by weight of a suitable filler
prior to during or subsequent to step (i); [0020] iv) optionally
introducing up to 5% by weight of a suitable organosilicon resin
and [0021] v) where required, adapting the foam control agent
produced in steps (i) to (iv) into a suitable form of delivery
therefor.
[0022] It is to be understood that steps (iii) and (iv) may take
place in any order and may, but need not, be both undertaken at the
same stage in the process. Most preferably step (iv) is undertaken
after step (ii) where required.
[0023] The concept of "comprising" where used herein is used in its
widest sense to mean and to encompass the notions of "include" and
"consist of". All viscosity measurements referred to herein were
measured at 25.degree. C. unless otherwise indicated.
[0024] For the sake of this application an inert fluid (e.g. the
inert organopolysiloxane and/or organic fluid) is intended to be
unreactive towards any other constituent of step (i), (ii) and
(iii) above. i.e. it does not chemically participate in the
polymerisation reaction of step (i) and does not chemically
interact with the additives introduced in steps (ii) and (iii).
Indeed it is possible that the filler and resin of steps (ii) and
(iii) respectively, may be introduced into the mixture in the form
of a concentrate comprising the filler and/or resin in the inert
fluid, especially if this aids processing.
[0025] A polysiloxane containing polymer is intended to mean a
polymer comprising multiple organosiloxane or polyorganosiloxane
groups per molecule and is intended to include a polymer
substantially containing only organosiloxane or polyorganosiloxane
groups in the polymer chain and polymers where the backbone
contains both organosiloxane and/or polyorganosiloxane groups and
e.g. organic polymeric groups in the polymeric chain. Such polymers
can be homopolymers or co-polymers, including, but not limited to,
block co-polymers and random co-polymers.
[0026] In accordance with the present invention a polysiloxane
containing polymer which has been prepared in the presence of an
inert fluid in accordance with the present invention preferably has
the general formula:
R.sub.(3-a)R.sup.1.sub.aSiO[(R.sub.2SiO).sub.b(RR.sup.1SiO).sub.c]SiR.su-
b.(3-a)R.sup.1.sub.a (1)
wherein each R is the same or different and is an alkyl group
preferably containing 1-8 carbon atoms, a substituted alkyl group
preferably containing 1 to 6 carbon atoms an optionally substituted
phenyl group or an optionally substituted alkylphenyl group; each
R.sup.1 is hydrogen, a hydroxy group, a hydrolysable group or an
unsaturated organic group; a is zero or 1, b is an integer and c is
zero or an integer and the sum of b+c is equal to a value of at
least 200 preferably at least 500, more preferably at least 1500.
Such a polymer may comprise a degree of branching.
[0027] For the purpose of this application "Substituted", when used
in relation to hydrocarbon groups, means one or more hydrogen atoms
in the hydrocarbon group has been replaced with another
substituent. Examples of such substituents include, but are not
limited to, halogen atoms such as chlorine, fluorine, bromine, and
iodine; halogen atom containing groups such as chloromethyl,
perfluorobutyl, trifluoroethyl, and nonafluorohexyl; oxygen atoms;
oxygen atom containing groups such as (meth)acrylic and carboxyl;
nitrogen atoms; nitrogen atom containing groups such as amines,
amino-functional groups, amido-functional groups, and
cyano-functional groups; sulphur atoms; and sulphur atom containing
groups such as mercapto groups.
[0028] The polymeric chain may comprise blocks made from chains of
units depicted in Formula (1) above where the two R groups or R and
R.sup.1 groups are [0029] both alkyl groups (preferably both methyl
or ethyl), or [0030] alkyl and phenyl groups, or [0031] alkyl and
fluoropropyl, or [0032] alkyl and alkenyl or [0033] alkyl and
alkylphenyl; or [0034] alkyl and hydrogen groups. Typically at
least one block will comprise siloxane units in which both R groups
are alkyl groups.
[0035] Whilst preferably the polysiloxane containing polymer has a
substantially organopolysiloxane molecular chain, the polysiloxane
containing polymer may alternatively contain a block copolymeric
backbone comprising at least one block of siloxane groups and an
organic component comprising any suitable organic based polymer
backbone for example the organic polymer backbone may comprise, for
example, polystyrene and/or substituted polystyrenes such as
poly(.alpha.-methylstyrene), poly(vinylmethylstyrene), dienes,
poly(p-trimethylsilylstyrene) and
poly(p-trimethylsilyl-.alpha.-methylstyrene). Other organic
components which may be incorporated in the polymeric backbone may
include acetylene terminated oligophenylenes, vinylbenzyl
terminated aromatic polysulphones oligomers, aromatic polyesters,
aromatic polyester based monomers, polyalkylenes, polyurethanes,
aliphatic polyesters, aliphatic polyamides and aromatic polyamides
and the like.
[0036] However perhaps the most preferred organic based polymeric
blocks in polysiloxane containing polymer are polyoxyalkylene based
blocks. The oxyalkylene units are not necessarily identical
throughout the polyoxyalkylene monomer, but can differ from unit to
unit. A polyoxyalkylene block, for example, can be comprised of
oxyethylene units, (--C.sub.2H.sub.4--O--); oxypropylene units
(--C.sub.3H.sub.6--O--); or oxybutylene units,
(--C.sub.4H.sub.8--O--); or mixtures thereof. Preferably the
polyoxyalkylene polymeric backbone consists essentially of
oxyethylene units and/or oxypropylene units.
[0037] Other polyoxyalkylene blocks in the polysiloxane containing
polymer may include for example units of the structure--
--[--R.sup.2--O--(--R.sup.3--O--).sub.d-Pn-C(R.sup.4).sub.2-Pn-O--(--R.s-
up.3--O--).sub.e--R.sup.2]--
in which Pn is a 1,4-phenylene group, each R.sup.2 is the same or
different and is a divalent hydrocarbon group having 2 to 8 carbon
atoms, each R.sup.3 is the same or different and, is, an ethylene
group propylene group or isopropylene group, each R.sup.4 is the
same or different and is a hydrogen atom or methyl group and each
of the subscripts d and e is a positive integer in the range from 3
to 30.
[0038] In accordance with the present invention it is to be
understood that the polysiloxane containing polymer is polymerised
in an inert fluid. It is to be understood that the term "inert
fluid" is intended to mean a substantially non-volatile fluid which
is neither involved in the polymerisation process nor is removed
prior to emulsification. Hence the inert fluid is substantially
present in the emulsion.
[0039] Preferably the inert fluid is selected from an
organopolysiloxane extender and/or plasticiser and/or an organic
extender or plasticiser or a cyclic siloxane comprising between 3
and 20 silicon atoms. Preferably the inert fluid has a viscosity of
from 0.65 mPas at 25.degree. C. -10000 mPas at 25.degree. C.
[0040] Preferably each extender and or plasticiser is miscible or
at least substantially miscible with the monomeric starting
materials with which they are initially mixed, and more
particularly miscible with both intermediate polymerisation
reaction products and the final polymerisation product. Extenders
and/or plasticisers which are "substantially miscible" are intended
to include extenders and/or plasticisers which are completely or
largely miscible with the monomer(s) and/or the reaction mixture
during polymerisation and hence may include low melting point
solids which become miscible liquids in a reaction mixture during
the polymerisation process.
[0041] For the sake of this application an extender (sometimes also
referred to as a process aid or secondary plasticiser) is a
compound typically used to dilute silicone based compositions to
make them more economically competitive without substantially
negatively affecting the properties of the formulation.
[0042] Suitable inert liquids include trialkylsilyl terminated
polydialkylsiloxanes and derivatives thereof which may comprise a
degree of substitution, with the provision that any substituted
groups in the inert fluid do not participate in the polymerisation
reaction. The substituted groups on the inert fluid are preferably
the same as those identified in the previous definition of
substituted groups with respect to hydrocarbon groups. Preferably
each alkyl group may be the same or different and comprises from 1
to 8 carbon atoms but is preferably a methyl or ethyl group,
preferably with a viscosity of from 0.65 to 100 000 mPas at
25.degree. C. and most preferably from 10 to 1000 mPas at
25.degree. C.
[0043] The inert fluid may comprise any suitable organic
extender/organic plasticiser.
[0044] Mineral oil extenders and plasticisers are however
particularly preferred. Examples include linear or branched mono
unsaturated hydrocarbons such as linear or branched alkenes or
mixtures thereof containing at least 12, e.g. from 12 to 25 carbon
atoms; and/or mineral oil fractions comprising linear (e.g.
n-paraffinic) mineral oils, branched (iso-paraffinic) mineral oils,
cyclic (referred in some prior art as naphthenic) mineral oils and
mixtures thereof. Preferably the hydrocarbons utilised comprise at
least 10, preferably at least 12 and most preferably greater than
20 carbon atoms per molecule.
[0045] Other preferred mineral oil extenders include
alkylcycloaliphatic compounds, low molecular weight
polyisobutylenes, Phosphate esters, alkybenzenes including
polyalkylbenzenes which are unreactive with the polymer.
[0046] Any suitable mixture of mineral oil fractions may be
utilised as the extender in the present invention but high
molecular weight extenders (e.g. >220) are particularly
preferred. Examples include:--
alkylcyclohexanes (molecular weight>220); paraffinic
hydrocarbons and mixtures thereof containing from 1 to 99%,
preferably from 15 to 80% n-paraffinic and/or isoparaffinic
hydrocarbons (linear branched paraffinic) and 1 to 99%, preferably
85 to 20% cyclic hydrocarbons (naphthenic) and a maximum of 3%,
preferably a maximum of 1% aromatic carbon atoms. The cyclic
paraffinic hydrocarbons (naphthenics) may contain cyclic and/or
polycyclic hydrocarbons. Any suitable mixture of mineral oil
fractions may be used, e.g. mixtures containing [0047] (i) 60 to
80% paraffinic and 20 to 40% naphthenic and a maximum of 1%
aromatic carbon atoms; [0048] (ii) 30-50%, preferably 35 to 45%
naphthenic and 70 to 50% paraffinic and or isoparaffinic oils;
[0049] (iii) hydrocarbon fluids containing more than 60 wt. %
naphthenics, at least 20 wt. % polycyclic naphthenics and an ASTM
D-86 boiling point of greater than 235.degree. C.; [0050] (iv)
hydrocarbon fluid having greater than 40 parts by weight naphthenic
hydrocarbons and less than 60 parts by weight paraffinic and/or
isoparaffinic hydrocarbons based on 100 parts by weight of
hydrocarbons.
[0051] Preferably the mineral oil based extender or mixture thereof
comprises at least one of the following parameters: [0052] (i) a
molecular weight of greater than 150, most preferably greater than
200; [0053] (ii) an initial boiling point equal to or greater than
230.degree. C. (according to ASTM D 86). [0054] (iii) a viscosity
density constant value of less than or equal to 0.9; (according to
ASTM 2501) [0055] (iv) an average of at least 12 carbon atoms per
molecule, most preferably 12 to 30 carbon atoms per molecule;
[0056] (v) an aniline point equal to or greater than 70.degree. C.,
most preferably the aniline point is from 80 to 110.degree. C.
(according to ASTM D 611); [0057] (vi) a naphthenic content of from
20 to 70% by weight of the extender and a mineral oil based
extender has a paraffinic content of from 30 to 80% by weight of
the extender according to ASTM D 3238); [0058] (vii) a pour point
of from -50 to 60.degree. C. (according to ASTM D 97); [0059]
(viii) a kinematic viscosity of from 1 to 20 cSt at 40.degree. C.
(according to ASTM D 445) [0060] (ix) a specific gravity of from
0.7 to 1.1 (according to ASTM D1298); [0061] (x) a refractive index
of from 1.1 to 1.8 at 20.degree. C. (according to ASTM D 1218)
[0062] (xi) a density at 15.degree. C. of greater than 700
kg/m.sup.3(according to ASTM D4052) and/or [0063] (xii) a flash
point of greater than 100.degree. C., more preferably greater than
110.degree. C. (according to ASTM D 93) [0064] (xiii) a saybolt
colour of at least +30 (according to ASTM D 156) [0065] (xiv) a
water content of less than or equal to 250 ppm [0066] (xv) a
Sulphur content of less than 2.5 ppm (according to ASTM D 4927)
[0067] Other organic extenders may include for the sake of example,
fatty acids and fatty acid esters, alkylbenzene compounds suitable
for use include heavy alkylate alkylbenzene or an
alkylcycloaliphatic compound. Examples of alkyl substituted aryl
compounds useful as extenders and/or plasticisers are compounds
which have aryl groups, especially benzene substituted by alkyl and
possibly other substituents, and a molecular weight of at least
200.
[0068] The alkylbenzene compounds suitable for use include heavy
alkylate alkylbenzene or an alkylcycloaliphatic compound. Examples
of alkyl substituted aryl compounds useful as extenders and/or
plasticisers are compounds which have aryl groups, especially
benzene substituted by alkyl and possibly other substituents, and a
molecular weight of at least 200. Examples of such extenders are
described in U.S. Pat. No. 4,312,801, the content of which is
incorporated herein by reference. These compounds can be
represented by general formula (2), (3), (4) and (5)
##STR00001##
where R.sup.6 is an alkyl chain of from 1 to 30 carbon atoms, each
of R.sup.7 through to R.sup.16 is independently selected from
hydrogen, alkyl, alkenyl, alkynyl, halogen, haloalkyl, nitrile,
amine, amide, an ether such as an alkyl ether or an ester such as
an alkyl ester group, and n is an integer of from 1 to 25. Of these
compounds of formula (2) where each of R.sup.7, R.sup.8, R.sup.9,
R.sup.19 and R.sup.11 is hydrogen and R.sup.6 is a
C.sub.10-C.sub.13 alkyl group are preferred. A particularly useful
source of such compounds are the so-called "heavy alkylates", which
are recoverable from oil refineries after oil distillation.
Generally distillation takes place at temperatures in the range of
from 230 to 330.degree. C., and the heavy alkylates are present in
the fraction remaining after the lighter fractions have been
distilled off.
[0069] Examples of alkylcycloaliphatic compounds are substituted
cyclohexanes with a molecular weight in excess of 220. Examples of
such compounds are described in EP 0842974, the content of which is
incorporated herein by reference. Such compounds may be represented
by general formula (6).
##STR00002##
where R.sup.17 is a straight or branched alkyl group of from 1 to
25 carbon atoms, and R.sup.18 and R.sup.19 are independently
selected from hydrogen or a C.sub.1-25 straight or branched chain
alkyl group.
[0070] Alternatively the inert fluid may comprise may comprise a
suitable non-mineral based (i.e. not from petroleum or petroleum
based oils) natural oil or a mixture thereof, i.e. those derived
from animals, seeds and nuts such as for example almond oil,
avocado oil, beef tallow, borrage oil, butterfat, canola oil,
cardanol, cashew nut oil, cashew nutshell liquid, castor oil,
citrus seed oil, cocoa butter, coconut oil, cod liver oil, corn
oil, cottonseed oil, cuphea oil, evening primrose oil, hemp oil,
jojoba oil, lard, linseed oil, macadamia oil, menhaden oil, oat
oil, olive oil, palm kernel oil, palm oil peanut oil, poppy seed
oil, rapeseed oil, rice bran oil, safflower oil, safflower oil
(high oleic), sesame oil, soybean oil, sunflower oil, sunflower oil
(high oleic), tall oil, tea tree oil, turkey red oil, walnut oil
perilla oil, dehydrated castor oils, apricot oil, pine nut oil,
kukui nut oil, amazon nut oil almond oil, babasu oil, argan oil,
black cumin oil, bearberry oil, calophyllum oil, camelina oil,
carrot oil, carthamus oil, cucurbita oil, daisy oil, grape seed
oil, foraha oil, jojoba oil, queensland oil, onoethera oil, ricinus
oil, tamanu oil, tucuma oil, fish oils such as pilchard, sardine
and herring oils. The extender may alternatively comprise mixtures
of the above and/or derivatives of one or more of the above.
[0071] A wide variety of natural oil derivates are available. These
include transesterified natural vegetable oils, boiled natural oils
such as boiled linseed oil, blown natural oils and stand natural
oils. An example of a suitable transesterified natural vegetable
oil is known as biodiesel oil, the transesterification product
produced by reacting mechanically extracted natural vegetable oils
from seeds, such as rape, with methanol in the presence of a sodium
hydroxide or potassium hydroxide catalyst to produce a range of
esters dependent on the feed utilised. Examples might include for
example methyloleate
(CH.sub.3(CH.sub.2).sub.7CH.dbd.CH(CH.sub.2).sub.7CO.sub.2CH.sub.3).
[0072] Stand natural oils which are also known as thermally
polymerised or heat polymerised oils and are produced at elevated
temperatures in the absence of air. The oil polymerises by
cross-linking across the double bonds which are naturally present
in the oil. The bonds are of the carbon-carbon type. Stand natural
oils are pale coloured and low in acidity. They can be produced
with a wider range of viscosities than blown oils and are more
stable in viscosity. In general, stand natural oils are produced
from linseed oil and soya bean oil but can also be manufactured
based on other oils. Stand natural oils are widely used in the
surface coatings industry.
[0073] Blown oils which are also known as oxidised, thickened and
oxidatively polymerised oils and are produced at elevated
temperatures by blowing air through the oil. Again the oil
polymerises by cross-linking across the double bonds but in this
case there are oxygen molecules incorporated into the cross-linking
bond. Peroxide, hydroperoxide and hydroxyl groups are also present.
Blown oils may be produced from a wider range of oils than stand
natural oils. In general, blown oils are darker in colour and have
a higher acidity when compared to stand natural oils. Because of
the wide range of raw materials used, blown oils find uses in many
diverse industries, for example blown linseed oils are used in the
surface coatings industry and blown rapeseed oils are often used in
lubricants.
[0074] The amount of inert fluid which may be included in the
composition will depend upon factors such as the purpose to which
the composition is to be put, the molecular weight of the inert
fluid(s) concerned etc. Typical compositions may contain up to at
least 70% w/w or even 90% w/w inert fluids(s). Preferably suitable
polymer products comprise from 5 to 80% w/w of inert fluid(s).
[0075] Such polysiloxane containing polymers as prepared in step
(i) of the process in accordance with the present invention may be
made by a variety of routes with the polymers produced being
end-capped with compounds which will provide the required terminal
groupings on the polymer and provided the polymer or its precursors
and/or intermediates is/are diluted in the inert fluid described
above during the polymerisation process. Preferred routes to the
preparation of said polymers include
(i) polycondensation (ii) ring opening/equilibrium (iii)
polyaddition (iv) chain extension
[0076] (i) Polycondensation (i.e. the polymerisation of multiple
monomers and/or oligomers with the elimination of low molecular
weight by-product(s) such as water, ammonia or methanol etc.).
Any suitable polycondensation reaction pathway may be utilised.
Preferred are polycondensation reactions relying on the reaction
schemes below:--
[0077] The sort of reaction envisaged between the condensable end
groups of the starting materials are most preferably generally
linked to the interaction of compounds having hydroxyl and/or
hydrolysable end groups which can interact with the release of e.g.
water or methanol or the like. However, the following list
indicates other interactions which might be considered for the cure
process of the composition in accordance with the present
invention:-- [0078] 1) the condensation of organohalosilyl groups
with an organoalkoxysilyl groups, [0079] 2) the condensation of
organohalosilyl groups with organoacyloxysilyl groups, [0080] 3)
the condensation of organohalosilyl groups with organosilanols,
[0081] 4) the condensation of organohalosilyl groups with
silanolates, [0082] 5) the condensation of organo-hydrosilyl groups
with organosilanol groups [0083] 6) the condensation of
organoalkoxysilyl groups with organoacyloxysilyl groups [0084] 7)
the condensation of organoalkoxysilyl groups with organosilanol
groups, [0085] 8) the condensation of organoaminosilyl groups with
organosilanols, [0086] 9) the condensation of organoacyloxysilyl
groups silanolate groups [0087] 10) the condensation of
organoacyloxysilyl groups with organosilanols, [0088] 11) the
condensation of organooximosilyl groups with organosilanol groups
[0089] 12) the condensation of organoenoxysilyl groups with
organosilanols, [0090] 13) The condensation of a siloxane compound
comprising one or more hydrosilane functional groups with a
siloxane compounds containing at least one alkoxysilane functional
group, generating hydrocarbon by-products.
[0091] Most preferably the condensation reaction which occurs
between monomers/oligomers and intermediates with hydroxyl and/or
alkoxy end-groups thereby producing water or alcohols as a
by-product.
[0092] A preferred method for the polymerisation process is the
polymerisation of straight chain precursors and/or branched
organopolysiloxanes of formula (1) including for example
R.sub.(3-f)R.sup.5.sub.fSiO(R.sub.2SiO).sub.gSiR.sub.(3-f)R.sup.5.sub.f
R.sub.(3-f)R.sup.5.sub.fSiO(RR.sup.1SiO).sub.hSiR.sub.(3-f)R.sup.5.sub.f
R.sub.(3-f)R.sup.5.sub.fSiO[(R.sub.2SiO).sub.j(RR.sup.5SiO.sub.k]SiR.sub-
.(3-f)R.sup.5.sub.f
Where R is as previously defined, R.sup.5 is --OH or an alkoxy
group having from 1 to 6 carbon atoms, preferably a methoxy or
ethoxy group, f is 0 or 1, preferably 1, g is an integer from 2 to
100, h is from 2 to 100, j is an integer from 1 to 100 and k is an
integer between 1 to 100. Some branching may occur with the
presence of other groups in the polymeric chain but preferably this
is kept to a minimum.
[0093] The above starting materials preferably have a viscosity of
between 10 mPas and 5000 mPas at 25.degree. C.
[0094] Many of the above processes require the presence of
catalyst. Any suitable polycondensation catalyst may be utilised
including tin, lead, antimony, iron, cadmium, barium, manganese,
zinc, chromium, cobalt, nickel, titanium, aluminium, gallium or
germanium and zirconium based catalysts such as organic tin metal
catalysts and 2-ethylhexoates of iron, cobalt, manganese, lead and
zinc may alternatively be used.
[0095] Tin catalysts may include as triethyltin tartrate, tin
octoate, tin oleate, tin naphthate, butyltintri-2-ethylhexoate,
tinbutyrate, carbomethoxyphenyl tin trisuberate,
isobutyltintriceroate, and diorganotin salts especially diorganotin
dicarboxylate compounds such as dibutyltin dilaurate, dimethyltin
dibutyrate, dibutyltin dimethoxide, dibutyltin diacetate,
dimethyltin bisneodecanoate Dibutyltin dibenzoate, stannous
octoate, dimethyltin dineodeconoate, dibutyltin dioctoate.
Dibutyltin dilaurate, dibutyltin diacetate are particularly
preferred.
[0096] Titanate catalysts may comprise a compound according to the
general formula Ti[OR.sup.20].sub.4 and Zr[OR.sup.20].sub.4
respectively where each R.sup.20 may be the same or different and
represents a monovalent, primary, secondary or tertiary aliphatic
hydrocarbon group which may be linear or branched containing from 1
to 10 carbon atoms. Optionally the titanate may contain partially
unsaturated groups. However, preferred examples of R.sup.20 include
but are not restricted to methyl, ethyl, propyl, isopropyl, butyl,
tertiary butyl and a branched secondary alkyl group such as
2,4-dimethyl-3-pentyl. Preferably, when each R.sup.20 is the same,
R.sup.20 is an isopropyl, branched secondary alkyl group or a
tertiary alkyl group, in particular, tertiary butyl. Examples
include tetrabutyltitanate, tetraisopropyltitanate, or chelated
titanates or zirconates such as for example diisopropyl
bis(acetylacetonyl)titanate, diisopropyl
bis(ethylacetoacetonyl)titanate, diisopropoxytitanium
Bis(Ethylacetoacetate) and the like. Further examples of suitable
catalysts are described in EP1254192 and/or WO200149774 the
contents of which are incorporated herein by reference. The amount
of catalyst used depends on the cure system being used but
typically is from 0.01 to 3% by weight of the total
composition.
[0097] Other condensation catalysts which may be used, protic
acids, Lewis acids, organic and inorganic bases, metal salts and
organometallic complexes. Lewis acid catalysts. (a "Lewis acid" is
any substance that will take up an electron pair to form a covalent
bond). suitable for the polymerisation in the present invention
include, for example, boron trifluoride FeCl.sub.3, AlCl.sub.3,
ZnCl.sub.2, and ZnBr.sub.2.
[0098] More preferred are condensation specific catalysts such as
acidic condensation catalysts of the formula R.sup.21SO.sub.3H in
which R.sup.21 represents an alkyl group preferably having from 6
to 18 carbon atoms such as for example a hexyl or dodecyl group, an
aryl group such as a phenyl group or an alkaryl group such as
dinonyl- or didoecyl-naphthyl. Water may optionally be added.
Preferably R.sup.21 is an alkaryl group having an alkyl group
having from 6 to 18 carbon atoms such as dodecylbenzenesulphonic
acid (DBSA). Other condensation specific catalysts include
n-hexylamine, tetramethylguanidine, carboxylates of rubidium or
caesium, hydroxides of magnesium, calcium or strontium and other
catalysts as are mentioned in the art, e.g. in GB895091, GB918823
and EP 0382365. Also preferred are catalysts based on
phosphonitrile chloride, for example those prepared according to
U.S. Pat. No. 3,839,388, U.S. Pat. No. 4,564,693 or EP215470 and
phosphonitrile halide ion based catalysts, as described in
GB2252975, having the general formula
[X(PX.sub.2.dbd.N).sub.pPX.sub.m].sup.+[M.sup.2X.sub.(m-n+1)R.sup-
.III.sub.m].sup.-, wherein X denotes a halogen atom, M.sup.2 is an
element having an electronegativity of from 1.0 to 2.0 according to
Pauling's scale, R.sup.III'' is an alkyl group having up to 12
carbon atoms, p has a value of from 1 to 6, m is the valence or
oxidation state of M.sup.2 and n has a value of from 0 to m-1.
[0099] Alternatively the catalyst may comprise an oxygen-containing
chlorophosphazene containing organosilicon radicals having the
following general formula:--
Z.sup.1--PCl.sub.2.dbd.N(--PCl.sub.2.dbd.N).sub.q--PCl.sub.2--O
in which
[0100] Z.sup.1 represents an organosilicon radical bonded to
phosphorus via oxygen, a chlorine atom or the hydroxyl group
and
[0101] q represents 0 or an integer from 1 to 8. The catalyst may
also comprise condensation products of the above and/or tautomers
thereof (the catalyst exists in a tautomeric form when Z.sup.1 is a
hydroxyl group).
[0102] A further alternative catalyst which might be used as the
catalyst in the present invention is any suitable compound
providing a source of anions comprising at least one
quadri-substituted boron atom and protons capable of interaction
with at least one silanol group as defined in WO 01/79330.
[0103] The activity of the catalyst is preferably quenched by using
a neutralizing agent which reacts with the catalyst to render it
non-active. Typically in the case of the acid type condensation
catalysts the neutralising agent is a suitable base such as an
amine such as a mono/di and trialkanolamines for example
monoethanolamine (MEA) and triethanolamine (TEA). In the case of
systems using a DBSA catalyst alternative quenching means include
aluminasilicate zeolite materials that were found to absorb DBSA
and leave a stable polymer. In most cases catalyst residues remain
in the polymer product or where appropriate may be removed by
filtration or alternative methods. In the case of phosphazene based
catalysts when the desired viscosity has been reached, the
viscosity of the organosilicon compound obtained in the process can
be kept constant by a procedure in which the catalyst used, or a
reaction product which has been formed from this catalyst by
reaction with organosilicon compound to be subjected to
condensation and/or equilibration and likewise promotes the
condensation and/or equilibration of organosilicon compounds, is
inhibited or deactivated by addition of inhibitors or deactivators
which have been employed to date in connection with phosphazenes,
for example, triisononylamine, n-butyllithium, lithium
siloxanolate, hexamethylcyclotrisilazane, hexamethyldisilazane and
magnesium oxide.
[0104] Where required the polymer obtained may be end-blocked as a
means of regulating the molecular weight of the polymer and/or to
add functionality. Whilst this end-blocking function can be
achieved by water as discussed above, other suitable end-blocking
agents include silanes having 1 group capable of reacting with the
terminal groups of the resulting polymeric constituent prepared in
the diluted polymer to produce the required end-groups for polymer
(a).
(III) Polyaddition
[0105] For the sake of this specification a "polyaddition" or
"addition polymerisation" process is a polymerisation process
whereby unlike in a condensation reaction no by-products such as
water or alcohols are generated from the monomeric and oligomeric
co-reactants during polymerisation. A preferred addition
polymerisation route is a hydrosilylation reaction between an
unsaturated organic group e.g. an alkenyl or alkynyl group and an
Si--H group in the presence of a suitable catalyst. In this route
suitable silanes may be utilised as well as siloxane containing
monomers and/or oligomers.
[0106] Typically the polyaddition route is utilised to form block
copolymers by reacting
a) (i) an organopolysiloxane or (ii) a silane with:-- b) one or
more organopolysiloxane polymer(s) via an addition reaction pathway
in the presence of the extender and/or plasticiser, and a suitable
catalyst and optionally an end-blocking agent; and where required
quenching the polymerisation process.
[0107] The organopolysiloxane or silane (a) is selected from a
silane (a) (ii) containing at least one group capable of undergoing
addition type reactions and an organopolysiloxane monomer (a) (i)
containing groups capable of undergoing addition type reactions.
The organopolysiloxane or silane (a) must contain substituents such
that it is capable of undergoing an appropriate addition reaction
with polymer (b). The preferred addition reaction is a
hydrosilylation reaction between an unsaturated group and an Si--H
group.
[0108] Preferably silane (a) (ii) has at least 1 and preferably 2
groups capable of undergoing addition type reactions with (b). When
the addition reaction is a hydrosilylation reaction the silane may
contain an unsaturated constituent but preferably contains at least
one Si--H group.
[0109] Most preferably each silane contains one or more Si--H
groups. In addition to the one or more Si--H groups, preferred
silanes may include for example an alkyl group, an alkoxy group, an
acyloxy group, a ketoximato group, an amino group, an amido group,
an acid amido group, an aminoxy group, a mercapto group, an
alkenyloxy group and the like. Among these, alkoxy, acyloxy,
ketoximato, amino, amido, aminoxy, mercapto and alkenyloxy groups
are preferred. Practical examples of the silicon hydride are
halosilane tri-chlorosilane, methyl dichlorosilane, dimethyl
chlorosilane, and phenyl dichlorosilane; alkoxy silanes, such as
tri-methyoxy silane, tri-ethoxy silane, methyl di-ethoxy silane,
methyl di-methoxy silane and phenyl-di-methoxy silane; acyloxy
silanes, such as methyl di-acetoxy silane and phenyl diacetoxy
silane; and ketoximato silanes, such as
bis-(dimethyl-ketoximate)-methyl silane and bis-(cyclohexyl
ketoximate)methyl silane. Among them, halosilanes and alkoxyl
silanes are preferred. Particularly preferred silanes include for
example methyl dimethoxy silane (H--Si (--CH.sub.3)
(--OCH.sub.3).sub.2).
[0110] It will be appreciated that the addition reaction between
silane (a) (ii) and (b) results in a polymer chain extension
process or as a means of end-blocking a polymer with pre-required
end groups, in which case the extender may be added in combination
with silane (a) (ii), i.e. immediately prior to the addition
reaction or may be present during the polymerisation of polymer (b)
and as such silane (a) (ii) is added to an extended polymer (b)
which has been polymerised in the presence of the extender.
[0111] Organopolysiloxane monomer (a) (i) is preferably in the form
of a straight chain and/or branched organopolysiloxane comprising
units of formula (1a)
R'.sub.a'SiO.sub.4-a'/2 (1a)
wherein each R' may be the same or different and denotes a
hydrocarbon group having from 1 to 18 carbon atoms, a substituted
hydrocarbon group having from 1 to 18 carbon atoms or a
hydrocarbonoxy group having up to 18 carbon atoms and a' has, on
average, a value of from 1 to 3, preferably 1.8 to 2.2. Preferably
each R' is the same or different and is exemplified, by, but not
limited to hydrogen, alkyl groups such as methyl, ethyl, propyl,
butyl, pentyl, hexyl, heptyl, octyl, undecyl, and octadecyl;
cycloalkyl such as cyclohexyl; aryl such as phenyl, tolyl, xylyl,
benzyl, and 2-phenylethyl; and halogenated hydrocarbon groups such
as 3,3,3-trifluoropropyl, 3-chloropropyl, and dichlorophenyl. Some
R' groups may be hydrogen groups. Preferably the
polydiorganosiloxanes are polydialkylsiloxanes, most preferably
polydimethylsiloxanes. When (a) is an organopolysiloxane monomer,
said organopolysiloxane monomer must have at least one group which
is reactable with at least two groups, typically the terminal
groups, of (b) via an addition reaction process. Preferably
organopolysiloxane (a) (i) comprises at least one Si--H per
molecule, preferably at least two Si--H groups per molecule.
Preferably organopolysiloxane (a) (i) is end-blocked with a
siloxane group of the formula H(R'').sub.2SiO.sub.1/2, wherein each
R'' is a hydrocarbon or substituted hydrocarbon group, most
preferably an alkyl group. Preferably organopolysiloxane (a) (i)
has a viscosity of between 10 mPas and 5000 mPas at 25.degree.
C.
[0112] Organopolysiloxane polymer (b) is preferably a straight
chain and/or branched organopolysiloxane comprising units of
formula (1b)
R'''.sub.a'SiO.sub.4-a'/2 (1b)
wherein each R''' may be the same or different and denotes a
hydrocarbon group having from 1 to 18 carbon atoms, a substituted
hydrocarbon group having from 1 to 18 carbon atoms or a
hydrocarbonoxy group having up to 18 carbon atoms and a' is as
previously described. Preferably no R''' groups may be hydrogen
groups. Preferably each R''' is the same or different and are
exemplified by, but not limited to alkyl groups such as methyl,
ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, undecyl, and
octadecyl; cycloalkyl such as cyclohexyl; aryl such as phenyl,
tolyl, xylyl, benzyl, and 2-phenylethyl; and halogenated
hydrocarbon groups such as 3,3,3-trifluoropropyl, 3-chloropropyl,
and dichlorophenyl.
[0113] Organopolysiloxane polymer (b) may comprise any suitable
organopolysiloxane polymeric backbone but is preferably linear or
branched, and comprises at least one, preferably at least two
substituent groups which will react with the aforementioned groups
in the organopolysiloxane or silane (a) via an addition reaction
pathway. Preferably the or each addition reactive substituent group
of polymer (b) is a terminal group. When the organopolysiloxane or
silane (a) comprises at least one Si--H group, the preferred
substituent groups on organopolysiloxane polymer (b), which are
designed to interact with the Si--H groups, are preferably
unsaturated groups (e.g. alkenyl terminated e.g. ethenyl
terminated, propenyl terminated, allyl terminated
(CH.sub.2.dbd.CHCH.sub.2--)) or terminated with acrylic or
alkylacrylic such as CH.sub.2.dbd.C(CH.sub.3)--CH.sub.2-- groups
Representative, non-limiting examples of the alkenyl groups are
shown by the following structures; H.sub.2C.dbd.CH--,
H.sub.2C.dbd.CHCH.sub.2--, H.sub.2C.dbd.C(CH.sub.3)CH.sub.2--,
H.sub.2C.dbd.CHCH.sub.2CH.sub.2--,
H.sub.2C.dbd.CHCH.sub.2CH.sub.2CH.sub.2--, and
H.sub.2C.dbd.CHCH.sub.2CH.sub.2CH.sub.2CH.sub.2
[0114] Representative, non-limiting examples of alkynyl groups are
shown by the following structures; HC.ident.C--,
HC.ident.CCH.sub.2--, HC.ident.CC(CH.sub.3)--,
HC.ident.CC(CH.sub.3).sub.2--,
HC.ident.CC(CH.sub.3).sub.2CH.sub.2Alternatively, the unsaturated
organic group can be an organofunctional hydrocarbon such as an
acrylate, methacrylate and the like such as alkenyl an/or alkynyl
groups. Alkenyl groups are particularly preferred.
[0115] In cases where the organopolysiloxane or silane (a)
comprises only one addition reactable group and (b) comprises two
addition reactable groups which will react with the
organopolysiloxane or silane (a), the resulting product will be an
"ABA" type polymeric product. Whereas when both the
organopolysiloxane or silane (a) comprises two addition reactable
groups and (b) comprises two addition reactable groups which will
react with the organopolysiloxane or silane (a) interaction between
the two components would lead to (AB)n block copolymers in which
the length of the polymer is largely determined by the relative
amounts of the two constituents.
[0116] It will also be appreciated that this hydrosilylation route
may be utilised to prepare silicone-organic copolymers by using an
organopolysiloxane polymer which contains organic groups in the
polymer backbone or by replacing organopolysiloxane polymer (b)
with, for example, alkenyl terminated polyethers. Hence linear
non-hydrolysable (AB)n block copolymers in accordance with the
present invention can be prepared by catalyzed hydrosilylation of
alkenyl terminated polyethers with SiH-terminated dialkylsiloxane
fluids. The resulting copolymer being a combination of
polyoxyalkylene blocks linked through silicon to carbon to oxygen
linkages (i.e. a propyleneoxy group) and the end-blocking groups
being selected from the group consisting of allyl, propenyl and/or
hydrogen (dialkyl) siloxy groups (dependent on the relative amounts
of the constituents which are present).
[0117] When the addition reaction chosen is a hydrosilylation
reaction, any suitable hydrosilylation catalyst may be utilised.
Such hydrosilylation catalysts are illustrated by any
metal-containing catalyst which facilitates the reaction of
silicon-bonded hydrogen atoms of the SiH terminated
organopolysiloxane with the unsaturated hydrocarbon group on the
polyoxyethylene. The metals are illustrated by ruthenium, rhodium,
palladium, osmium, iridium, or platinum.
[0118] Hydrosilylation catalysts are illustrated by the following;
chloroplatinic acid, alcohol modified chloroplatinic acids, olefin
complexes of chloroplatinic acid, complexes of chloroplatinic acid
and divinyltetramethyldisiloxane, fine platinum particles adsorbed
on carbon carriers, platinum supported on metal oxide carriers such
as Pt(Al.sub.2O.sub.3), platinum black, platinum acetylacetonate,
platinum(divinyltetramethyldisiloxane), platinous halides
exemplified by PtCl.sub.2, PtCl.sub.4, Pt(CN).sub.2, complexes of
platinous halides with unsaturated compounds exemplified by
ethylene, propylene, and organovinylsiloxanes, styrene
hexamethyldiplatinum, Such noble metal catalysts are described in
U.S. Pat. No. 3,923,705, incorporated herein by reference to show
platinum catalysts. One preferred platinum catalyst is Karstedt's
catalyst, which is described in Karstedt's U.S. Pat. Nos. 3,715,334
and 3,814,730, incorporated herein by reference. Karstedt's
catalyst is a platinum divinyl tetramethyl disiloxane complex
typically containing one weight percent of platinum in a solvent
such as toluene. Another preferred platinum catalyst is a reaction
product of chloroplatinic acid and an organosilicon compound
containing terminal aliphatic unsaturation. It is described in U.S.
Pat. No. 3,419,593, incorporated herein by reference. Most
preferred as the catalyst is a neutralized complex of platinous
chloride and divinyl tetramethyl disiloxane, for example as
described in U.S. Pat. No. 5,175,325.
[0119] Ruthenium catalysts such as RhCl.sub.3(Bu.sub.2S).sub.3 and
ruthenium carbonyl compounds such as ruthenium
1,1,1-trifluoroacetylacetonate, ruthenium acetylacetonate and
triruthinium dodecacarbonyl or a ruthenium 1,3-ketoenolate may
alternatively be used.
[0120] Other hydrosilylation catalysts suitable for use in the
present invention include for example rhodium catalysts such as
[Rh(O.sub.2CCH.sub.3).sub.2].sub.2, Rh(O.sub.2CCH.sub.3).sub.3,
Rh.sub.2(C.sub.8H.sub.15O.sub.2).sub.4,
Rh(C.sub.5H.sub.7O.sub.2).sub.3,
Rh(C.sub.5H.sub.7O.sub.2)(CO).sub.2,
Rh(CO)[Ph.sub.3P](C.sub.5H.sub.7O.sub.2),
RhX.sup.4.sub.3[(R.sup.3).sub.2S].sub.3,
(R.sup.2.sub.3P).sub.2Rh(CO)X.sup.4, (R.sup.2.sub.3P).sub.2Rh(CO)H,
Rh.sub.2X.sup.4.sub.2Y.sup.4.sub.4,
H.sub.aRh.sub.bolefin.sub.cCl.sub.d, Rh (O(CO)R.sup.3).sub.3,
(OH).sub.n where X.sup.4 is hydrogen, chlorine, bromine or iodine,
Y.sup.4 is an alkyl group, such as methyl or ethyl, CO,
C.sub.8H.sub.14 or 0.5 C.sub.8H.sub.12, R.sup.3 is an alkyl
radical, cycloalkyl radical or aryl radical and R.sup.2 is an alkyl
radical an aryl radical or an oxygen substituted radical, a is 0 or
1, b is 1 or 2, c is a whole number from 1 to 4 inclusive and d is
2, 3 or 4, n is 0 or 1. Any suitable iridium catalysts such as
Ir(OOCCH.sub.3).sub.3, Ir(C.sub.5H.sub.7O.sub.2).sub.3,
[Ir(Z.sup.2)(En).sub.2].sub.2, or (Ir(Z.sup.2)(Dien)].sub.2, where
Z.sup.2 is chlorine, bromine, iodine, or alkoxy, En is an olefin
and Dien is cyclooctadiene may also be used.
[0121] The hydrosilylation catalyst may be added to the present
composition in an amount equivalent to as little as 0.001 part by
weight of elemental platinum group metal, per one million parts
(ppm) of the composition. Preferably, the concentration of the
hydrosilylation catalyst in the composition is that capable of
providing the equivalent of at least 1 part per million of
elemental platinum group metal. A catalyst concentration providing
the equivalent of about 3-50 parts per million of elemental
platinum group metal is generally the amount preferred.
[0122] Typically when (a) has at least two Si--H groups, typically,
the process is carried out using approximately a 1:1 molar ratio of
(a) to (b). However, useful materials may also be prepared by
carrying out the process with an excess of either (a) or (b) but
this would be considered a less efficient use of the materials.
Typically, the material containing the unsaturation (b) is used in
slight excess to ensure all the Si--H is consumed in the reaction.
As polymer (b) used in the present invention is preferably
terminated with unsaturated end-groups, end-blocking agents are not
typically required when making the polymer via this route. However,
they may be utilised if required.
[0123] Optionally when a hydrosilylation route is utilised for
polymerisation a suitable hydrosilylation catalyst inhibitor may be
required. Any suitable platinum group type inhibitor may be used.
One useful type of platinum catalyst inhibitor is described in U.S.
Pat. No. 3,445,420, which is hereby incorporated by reference to
show certain acetylenic inhibitors and their use. A preferred class
of acetylenic inhibitors are the acetylenic alcohols, especially
2-methyl-3-butyn-2-ol and/or 1-ethynyl-2-cyclohexanol which
suppress the activity of a platinum-based catalyst at 25.degree. C.
A second type of platinum catalyst inhibitor is described in U.S.
Pat. No. 3,989,667, which is hereby incorporated by reference to
show certain olefinic siloxanes, their preparation and their use as
platinum catalyst inhibitors. A third type of platinum catalyst
inhibitor includes polymethylvinylcyclosiloxanes having three to
six methylvinylsiloxane units per molecule.
[0124] Compositions containing these hydrosilylation catalysts
typically require heating at temperatures of 70.degree. C. or above
to cure at a practical rate, particularly if an inhibitor is used.
Room temperature cure is typically accomplished with such systems
by use of a two-part system in which the cross-linker and inhibitor
are in one of the two parts and the platinum is in the other part.
The amount of platinum is increased to allow for curing at room
temperature. The optimum concentration of platinum catalyst
inhibitor is that which will provide the desired storage stability
or pot life at ambient temperature without excessively prolonging
the time interval required to cure the present compositions at
elevated temperatures. This amount will vary widely and will depend
upon the particular inhibitor that is used. Inhibitor
concentrations as low as one mole of inhibitor per mole of platinum
will in some instances yield a desirable level of storage stability
and a sufficiently short curing period at temperatures above about
70.degree. C. In other cases, inhibitor concentrations of up to 10,
50, 100, 500 or more moles per mole of platinum may be needed. The
optimum concentration for a particular inhibitor in a given
composition can be determined by routine experimentation.
[0125] Additional components can be added to the hydrosilylation
reaction which are known to enhance such reactions. These
components include salts such as sodium acetate which have a
buffering effect in combination with platinum based catalysts.
[0126] For this type of polymerisation the amount of
hydrosilylation catalyst used is not narrowly limited as long as
there is a sufficient amount to accelerate a reaction between
[0127] (a) (i) an organopolysiloxane or (ii) a silane the chosen of
which must contain at least one and preferably at least two Si--H
groups with [0128] (b) one or more organopolysiloxane polymer(s) or
an alternative therefore such as a polyoxyethylene having an
unsaturated hydrocarbon group at each molecular terminal at room
temperature or at temperatures above room temperature. The actual
amount of this catalyst will depend on the particular catalyst
utilized and is not easily predictable. However, for
platinum-containing catalysts the amount can be as low as one
weight part of platinum for every one million weight parts of
components (a) and (b). The catalyst can be added at an amount 10
to 120 weight parts per one million parts of components (a) and
(b), but is typically added in an amount from 10 to 60 weight parts
per one million parts of (a) and (b).
[0129] Where appropriate, polymers obtained via a hydrosilylation
route can also be cured and/or crosslinked by a hydrosilylation
reaction catalyst in combination with an organohydrogensiloxane as
the curing agent providing each polymer molecule produced contains
at least two unsaturated groups suitable for cross-linking with the
organohydrogensiloxane. To effect curing of the present
composition, the organohydrogensiloxane must contain more than two
silicon bonded hydrogen atoms per molecule. The
organohydrogensiloxane can contain, for example, from about 4-20
silicon atoms per molecule, and have a viscosity of up to about 10
Pas at 25.degree. C. The silicon-bonded organic groups present in
the organohydrogensiloxane can include substituted and
unsubstituted alkyl groups of 1-4 carbon atoms that are otherwise
free of ethylenic or acetylenic unsaturation.
(IV) Chain Extension
[0130] In this case rather than adding chain extender into a final
pre-prepared polymer composition the extender is mixed into the
polymer during a chain extension polymerisation step. Typically the
polymeric starting material is an organopolysiloxane having end
groups suitable for interaction with the chosen chain extending
materials. Typically the polymer end groups are either hydrolysable
or suitable for addition reaction (typically hydrosilylation) and
the chain extending material is chosen on the basis of having
suitable reactive groups which will chain extend the polymer.
Preferred chain extending materials for chain extending polymers
having hydroxyl and/or hydrolysable end groups are as hereinbefore
described.
[0131] For pre-formed polymers with alkenyl or Si--H groups
(typically end groups) suitable for addition reactions via a
hydrosilylation route the chain extender will contain two groups
which will undergo an addition reaction with the respective
addition reactive groups on the chosen polymer. Such chain
extenders may include for example:--
A silane comprising two alkenyl groups, a dihydrosilane, a
polydialkylsiloxane having a degree of polymerisation of from 2 to
25 and at least one Si-alkenyl bond per terminal group, A
polydialkylsiloxane having a degree of polymerisation of from 2 to
25 and at least one Si--H bond per terminal group and wherein each
alkyl group independently comprises from 1 to 6 carbon atoms;
organosilicon compounds with the general formula
##STR00003##
in which R is as hereinbefore described, j is 1, 2, or 3, k is 0 or
1, and j+k is 2 or 3. exemplified by compounds with the following
formulas, (ViMe.sub.2SiO).sub.2SiVi(OMe).sub.1
(ViMe.sub.2SiO).sub.1SiVi(OMe).sub.2,
(ViMe.sub.2SiO).sub.2SiVi(OEt).sub.1,
(ViMe.sub.2SiO).sub.1SiVi(OEt).sub.2,
(ViMe.sub.2SiO).sub.3Si(OMe).sub.1,
(ViMe.sub.2SiO).sub.2Si(OMe).sub.2,
(ViMe.sub.2SiO).sub.3Si(OEt).sub.1 and
(ViMe.sub.2SiO).sub.2Si(OEt).sub.2
[0132] As used herein, Vi represents a vinyl group, Me represents a
methyl group, and Et represents an ethyl group.
[0133] The catalyst used to catalyse the chain extension reaction
is determined by the reaction to take place. When the reaction
occurring is a condensation reaction any suitable condensation
catalyst as hereinbefore described may be utilised. When the
reaction occurring is a hydrosilylation reaction any suitable
hydrosilylation catalyst as hereinbefore described may be
utilised.
[0134] Where required the polymer contains hydrolysable terminal
groups, end-blocking agents as described above in relation to
condensation may be utilised to obtain appropriate terminal groups.
Where required the polymer contains addition reactable terminal
groups, end-blocking agents as described above in relation to
polyaddition may be utilised to obtain appropriate terminal
groups.
[0135] The process can be carried out either batchwise or
continuously on any suitable mixers. In case of a polycondensation,
generated water can either be removed by chemical drying using e.g.
hydrolysable silanes like methyltrimethoxysilane or by physical
separation using evaporation, coalescing or centrifuging
techniques.
[0136] Chain extension may take place at any suitable temperature
and pressure for the process concerned in batch or continuous modes
of operation as preferred. Hence in the case of the phosphazene
catalysed methods polymerisation may occur at temperatures of
between 50.degree. C. to 200.degree. C., more preferably 80.degree.
C. to 160.degree. C. Furthermore, in order to facilitate removal of
the by-products formed during the condensation, for example, water,
HCl or alcohol, the condensation and/or equilibration of the
organosilicon compounds may be carried out at a pressure below 80
kPa. Alternative methods for the removal of condensation
by-products include removal by chemical drying using e.g.
hydrolysable silanes like methyltrimethoxysilane (where
appropriate) or by physical separation using evaporation,
coalescing or centrifuging techniques.
[0137] The process can be carried out either batchwise or
continuously on any suitable mixers. In case of a polycondensation,
generated water may, if required, be removed by chemical drying
using e.g. hydrolysable silanes like methyltrimethoxysilane or by
physical separation using evaporation, coalescing or centrifuging
techniques.
[0138] The Hydrophobic fillers of step (iii) in accordance with the
method of the present invention for the preparation of foam control
agents are well known and may be materials such as silica,
preferably with a surface area as measured by BET measurement of at
least 50 m.sup.2/g, titania, ground quartz, alumina, an
aluminosilicate, an organic waxes e.g. polyethylene wax or
microcrystalline wax, zinc oxide, magnesium oxide, a salt of an
aliphatic carboxylic acids, a reaction product of an isocyanate
with an amine, e.g. cyclohexylamine, or an alkyl amide such as
ethylenebisstearamide or methylenebisstearamide. Mixtures of two or
more of these can be used. Silica fillers are particularly
preferred. Preferred silica materials are those which are prepared
by heating, e.g. fumed silica, or precipitation, although other
types of silica such as those made by gel formation are also
acceptable. The silica filler may for example have an average
particle size of 0.5 to 50 .mu.m, preferably 2 to 30 and most
preferably 5 to 25 .mu.m. Such materials are well known and are
commercially available, both in hydrophilic form and in hydrophobic
form.
[0139] Some of the fillers mentioned above are not hydrophobic in
nature, but can be used if made hydrophobic. Such fillers may be
rendered hydrophobic either in situ (i.e. by introducing a
hydrophobing agent before during or after step (iii) of the process
of the present invention, or by pre-treatment of the filler prior
to step (iii) of the process. The hydrophobing of fillers, where
required may be carried out by treatment with a fatty acid, but is
preferably done by the use of methyl substituted organosilicon
materials. Suitable hydrophobing agents include
polydimethylsiloxanes, dimethylsiloxane polymers which are
end-blocked with silanol or silicon-bonded alkoxy groups,
hexamethyldisilazane, hexamethyldisiloxane. The organosilicon
resins optionally introduced in step (iv) of the process in
accordance with the invention (as discussed below) may also
function as filler hydrophobing agents.
[0140] The amount of filler in the foam control agent of the
invention is preferably from 0.5 to 50% by weight based on
polysiloxane containing polymer, more preferably from 1 up to 10 or
15% and most preferably 2 to 8%. When present, it is also preferred
that the ratio of the weight of organosilicon resin to filler is
from 1/10 to 20/1, preferably 1/5 to 10/1, most preferably 1/2 to
6/1.
[0141] Where the filler needs to be made hydrophobic in situ, the
manufacturing process would include a heating stage, preferably
under reduced pressure, in which the filler and the treating agent
are mixed together in part or all of polysiloxane containing
polymer and/or all or part of fluid (B), possibly in the presence
of a suitable catalyst, where required.
[0142] The optional organosilicon resin which may be introduced in
accordance with step (iv) of the present invention is generally a
non-linear siloxane resin and comprises (and most preferably
consists of) siloxane units of the formula
R.sup.25.sub.sSiO.sub.4-s/2 wherein R.sup.25 denotes a hydroxyl,
hydrocarbon or hydrocarbonoxy group, and wherein s has an average
value of from 0.5 to 2.4. It preferably consists of monovalent
trihydrocarbonsiloxy (M) groups of the formula
R.sup.26.sub.3SiO.sub.1/2 and tetrafunctional (O) groups
SiO.sub.4/2 wherein R.sup.26 denotes a monovalent hydrocarbon
group. The number ratio of M groups to Q groups is preferably in
the range 0.4:1 to 2.5:1 (equivalent to a value of a in the formula
R.sup.25'.sub.sSiO.sub.4-s/2 of 0.86 to 2.15), more preferably
0.4:1 to 1.1:1 and most preferably 0.5:1 to 0.8:1 (equivalent to
s=1.0 to s=1.33). The organosilicon resin is preferably a solid at
room temperature but MQ resins having a M/Q ratio higher than 1.2,
which are generally liquids, can be used successfully. For
industrial foam control applications such as defoaming of black
liquor in the paper and pulp industry, resins having a high M/Q
ratio may be preferred. Although it is most preferred that the
resin consists only of monovalent and tetravalent siloxy units as
defined above, a resin comprising M groups, trivalent
R.sup.25SiO.sub.3/2 (T) units and Q units can alternatively be
used. It is also acceptable that up to 20% of all units present can
be divalent units R.sup.25.sub.2SiO.sub.2/2. The group R.sup.25 is
preferably an alkyl group having 1 to 6 carbon atoms, for example
methyl or ethyl, or can be phenyl. It is particularly preferred
that at least 80%, most preferably substantially all, R.sup.25
groups present are methyl groups. Other hydrocarbon groups may be
present, e.g. alkenyl groups present for example as
dimethylvinylsilyl units, preferably not exceeding 5% of all
R.sup.25 groups. Silicon bonded hydroxyl groups and/or alkoxy, e.g.
methoxy groups may also be present.
[0143] Such organosilicon resins are well known. They can be made
in solvent or in situ, e.g. by hydrolysis of certain silane
materials. Particularly preferred is the hydrolysis and
condensation in the presence of a solvent e.g. xylene of a
precursor of the tetravalent siloxy unit (e.g. tetraorthosilicate,
tetraethyl orthosilicate, polyethyl silicate or sodium silicate)
and a precursor of monovalent trialkylsiloxy units (e.g.
trimethylchlorosilane, trimethylethoxysilane, hexamethyldisiloxane
or hexamethyldisilazane). The resulting MQ resin can if desired be
further trimethylsilylated to react out residual Si--OH groups or
can be heated in the presence of a base to cause self-condensation
of the resin by elimination of Si--OH groups.
[0144] When present the organosilicon resin is preferably present
in the antifoam at from 0.1 to 20% by weight of the formulation,
and most preferably from 0.5 to 10%.
[0145] The organosilicon resin may be insoluble in the inert
organopolysiloxane but is generally insoluble in the organic fluid
but may be soluble or insoluble in the polysiloxane containing
polymer and may be soluble or insoluble in the mixture of step (i)
of the process in accordance with the present invention.
[0146] In step (iv) of the process in accordance with the present
invention the resin can be added into the foam control agent as a
solution in a non-volatile solvent, for example an alcohol such as
dodecanol or 2-butyl-octanol or an ester such as octyl stearate. A
resin solution prepared in a volatile solvent such as xylene can be
mixed with the non-volatile solvent and the volatile solvent
removed by stripping or other form of separation. In most cases the
non-volatile solvent can be left in the foam control agent. It is
preferred that the resin is dissolved in an equal amount of
non-volatile solvent or less, preferably no more than half its
weight of solvent. If the resin is added as a solution and is
insoluble in the mixture of polysiloxane containing polymer and
organic liquid, it will generally form solid particles of
acceptable particle size on mixing.
[0147] The resin can alternatively be added into the foam control
agent in the form of solid particles, for example spray dried
particles or flakes etc. Spray dried MQ resins are available
commercially, for example of average particle size 10 to 200
microns.
[0148] When required in a composition prepared by the method in
accordance with the present invention the means by which
organosilicon resin is introduced during step (iv) may be dependent
on solubility of the resin. Solubility can be measured by observing
a mixture of the resin of step (iv) in accordance with the
invention with the polysiloxane containing and/or its precursors
and/or the inert organopolysiloxane and/or organic fluid using an
optical microscope.
[0149] The factors affecting the solubility of the resin in the
mixture in step (i) of the process in accordance with the present
invention include the chemical nature of the starting materials and
of the resulting polymer produced.
[0150] The level of insolubility of the resin in the mixture of
polysiloxane containing polymer and liquid (B) may affect its
particle size in the composition. The lower the solubility of the
siloxane resins in the constituents of step (i) of the process in
accordance with the present invention the larger the particle size
tends to be when the resin is introduced in step (iv). Thus a
siloxane resin which is soluble at 1% by weight in the constituents
of step (i) of the process in accordance with the present invention
will tend to form smaller particles than a resin which is only
soluble at 0.01% by weight. Resins which are partly soluble in the
mixture of step (i), that is having a solubility of at least 0.1%
by weight, are preferred.
[0151] The molecular weight of the resin can be increased by
condensation, for example by heating in the presence of a base. The
base can for example be an aqueous or alcoholic solution of
potassium hydroxide or sodium hydroxide, e.g. a solution in
methanol or propanol. The MQ resins of increased molecular weight
have improved resistance to loss of performance over time when
stored in contact with the detergent, for example as an emulsion in
liquid detergent. The reaction between resin and base may be
carried out in the presence of the silica, in which case there may
be some reaction between the resin and the silica. The reaction
with base can be carried out in the presence of the polysiloxane
containing polymer and/or in the presence of the non-volatile
solvent and/or in the presence of a volatile solvent. The reaction
with base may hydrolyse an ester non-volatile solvent such as octyl
stearate but we have found that this does not detract from the foam
control performance.
[0152] The foam control agents according to the present invention
may be provided as a product of the process in accordance with the
present invention, but for some applications it may be preferred to
make them available in alternative forms. For example for use in
aqueous media, it may be appropriate to provide the foam control
agent in an emulsion form, preferably an oil-in-water emulsion.
[0153] Preferably the viscosity of the mixture of the polymer and
inert fluid prior to emulsifying is in the range of viscosity of
from 500 to 10 000 000 mPas at 25.degree. C. most preferably 1000
to 100 000 mPas at 25.degree. C.
[0154] Methods of providing silicone-based foam control agents in
oil-in-water emulsion form are known and have been described in a
number of publications and patent specifications. Examples are
EP913187, EP978628, WO9822196, WO9800216, GB2315757, EP499304 and
EP459512. Emulsions may be made according to any of the known
techniques, and may be macro-emulsions or micro-emulsions, however
macro-emulsions are preferred.
[0155] In general, they comprise the foam control agent as the
disperse phase, one or more surfactants, water and standard
additives, such as preservatives, viscosity modifiers and
thickeners. The surfactants may be selected from anionic, cationic,
nonionic or amphoteric materials. Mixtures of one or more of these
may also be used.
[0156] Any suitable surfactant or combination of surfactants may be
utilised. The surfactant can in general be a non-ionic surfactant,
a cationic surfactant, an anionic surfactant, or an amphoteric
surfactant, although not all procedures for carrying out the
process of the invention can be used with all surfactants. The
amount of surfactant used will vary depending on the surfactant,
but generally is up to about 30 wt. % based on the
polydiorganosiloxane.
[0157] Examples of nonionic surfactants include condensates of
ethylene oxide with long chain fatty alcohols or fatty acids such
as a C.sub.12-16 alcohol, condensates of ethylene oxide with an
amine or an amide, condensation products of ethylene and propylene
oxide, esters of glycerol, sucrose, sorbitol, fatty acid alkylol
amides, sucrose esters, fluoro-surfactants, fatty amine oxides,
polyoxyalkylene alkyl ethers such as polyethylene glycol long chain
(12-14C) alkyl ether, polyoxyalkylene sorbitan ethers,
polyoxyalkylene alkoxylate esters, polyoxyalkylene alkylphenol
ethers, ethylene glycol propylene glycol copolymers and
alkylpolysaccharides, for example materials of the structure
R.sup.24--O--(R.sup.25O).sub.s-(G).sub.t wherein R.sup.24
represents a linear or branched alkyl group, a linear or branched
alkenyl group or an alkylphenyl group, R.sup.25 represent an
alkylene group, G represents a reduced sugar, s denotes 0 or a
positive integer and t represent a positive integer as described in
U.S. Pat. No. 5,035,832. non ionic surfactants additionally include
polymeric surfactants such as polyvinyl alcohol (PVA) and
polyvinylmethylether. Suitable nonionic surfactants include
silicones such as those described as Surfactants 1 to 6 in EP
638346, particularly siloxane polyoxyalkylene copolymers,
condensates of ethylene oxide with a long chain (fatty) alcohol or
(fatty) acid, for example C.sub.14-15 alcohol, condensed with 7
moles of ethylene oxide (Dobanol.RTM. 45-7), condensates of
ethylene oxide with an amine or an amide, condensation products of
ethylene and propylene oxides, fatty acid alkylol amides, fatty
amine oxides, esters of sucrose, glycerol or sorbitol and
fluoro-surfactants
[0158] Representative examples of suitable commercially available
nonionic surfactants include polyoxyethylene fatty alcohols sold
under the tradename BRIJ.RTM. by Uniqema (ICI Surfactants),
Wilmington, Del. and. Some examples are BRIJ.RTM. 35 Liquid, an
ethoxylated alcohol known as polyoxyethylene (23) lauryl ether, and
BRIJ.RTM. 30, another ethoxylated alcohol known as polyoxyethylene
(4) lauryl ether. polyoxyethylene fatty alcohols sold under the
tradename VOLPO.RTM. by Croda Nev.; ethoxylated alcohols sold under
the trademark TERGITOL.RTM. by The Dow Chemical Company, Midland,
Mich. Some example are TERGITOL.RTM. TMN-6, an ethoxylated alcohol
known as ethoxylated trimethylnonanol; and various of the
ethoxylated alcohols, i.e., C.sub.12-C.sub.14 secondary alcohol
ethoxylates, sold under the trademarks TERGITOL.RTM. 15-S-5,
TERGITOL.RTM. 15-S-12, TERGITOL.RTM. 15-S-15, and TERGITOL.RTM.
15-S-40. Surfactants containing silicon atoms can also be used.
[0159] Examples of suitable amphoteric surfactants include
imidazoline compounds, alkylaminoacid salts, and betaines. Specific
examples include cocamidopropyl betaine, cocamidopropyl
hydroxysulfate, cocobetaine, sodium cocoamidoacetate, cocodimethyl
betaine, N-coco-3-aminobutyric acid and imidazolinium carboxyl
compounds. Suitable amphoteric organic detergent surfactants
include imidazoline compounds, alkylaminoacid salts and betaines
Representative examples of suitable amphoteric surfactants include
imidazoline compounds, alkylaminoacid salts, and betaines.
[0160] Examples of cationic surfactants include quaternary ammonium
hydroxides such as octyl trimethyl ammonium hydroxide, dodecyl
trimethyl ammonium hydroxide, hexadecyl trimethyl ammonium
hydroxide, octyl dimethyl benzyl ammonium hydroxide, decyl dimethyl
benzyl ammonium hydroxide, didodecyl dimethyl ammonium hydroxide,
dioctadecyl dimethyl ammonium hydroxide, tallow trimethyl ammonium
hydroxide and coco trimethyl ammonium hydroxide as well as
corresponding salts of these materials, Suitable cationic organic
surfactants include alkylamine salts, quaternary ammonium salts,
sulphonium salts and phosphonium salts fatty amines and fatty acid
amides and their derivatives, basic pyridinium compounds,
quaternary ammonium bases of benzimidazolines and
polypropanolpolyethanol amines. Other representative examples of
suitable cationic surfactants include alkylamine salts, sulphonium
salts, and phosphonium salts.
[0161] Examples of suitable anionic surfactants include alkyl
sulphates such as lauryl sulphate, polymers such as
acrylates/C.sub.10-30 alkyl acrylate crosspolymer
alkylbenzenesulfonic acids and salts such as hexylbenzenesulfonic
acid, octylbenzenesulfonic acid, decylbenzenesulfonic acid,
dodecylbenzenesulfonic acid, cetylbenzenesulfonic acid and
myristylbenzenesulfonic acid; the sulphate esters of monoalkyl
polyoxyethylene ethers; alkylnapthylsulfonic acid; alkali metal
sulforecinates, sulfonated glyceryl esters of fatty acids such as
sulfonated monoglycerides of coconut oil acids, salts of sulfonated
monovalent alcohol esters, amides of amino sulfonic acids,
sulfonated products of fatty acid nitriles, sulfonated aromatic
hydrocarbons, condensation products of naphthalene sulfonic acids
with formaldehyde, sodium octahydroanthracene sulfonate, alkali
metal alkyl sulphates, ester sulphates, and alkarylsulfonates.
Suitable anionic organic surfactants include alkali metal soaps of
higher fatty acids, alkyl aryl sulphonates, for example sodium
dodecyl benzene sulphonate, long chain (fatty) alcohol sulphates,
olefin sulphates and sulphonates, sulphated monoglycerides,
sulphated esters, sulphonated or sulphated ethoxylate alcohols,
sulphosuccinates, alkane sulphonates, phosphate esters, alkyl
isethionates, alkyl taurates and/or alkyl sarcosinates. Anionic
surfactants include alkali metal soaps of higher fatty acids,
alkylaryl sulphonates such as sodium dodecyl benzene sulphonate,
long chain fatty alcohol sulphates, olefin sulphates and olefin
sulphonates, sulphated monoglycerides, sulphated esters,
sulphonated ethoxylated alcohols, sulphosuccinates, alkane
sulphonates, phosphate esters, alkyl isethionates, alkyl taurates,
and alkyl sarcosinates. One example of a preferred anionic
surfactant is sold commercially under the name Bio-Soft N-300. It
is a triethanolamine linear alkylate sulphonate composition
marketed by the Stephan Company, Northfield, Ill.
[0162] The above surfactants may be used individually or in
combination.
[0163] In a preferred embodiment of the present invention the
polymerisation catalyst is selected with a view to additionally
being the or one of the surfactants involved in the emulsification
process. A particularly preferred family of catalysts which also
function as surfactants when present in antifoam compositions are
acidic condensation catalysts such as for example DBSA as discussed
above.
[0164] Nonionic or anionic surfactants are preferred. Of particular
interest are surfactants which are environmentally acceptable. The
concentration of foam control agent in an emulsion may vary
according to applications, required viscosity, effectiveness of the
foam control agent and addition system, and ranges on average from
5 to 80% by weight, preferably 10 to 50%, more preferably 25 to
40%.
[0165] A foam control emulsion may also contain a stabilising agent
such as a silicone glycol copolymer or a crosslinked
organopolysiloxane polymer having at least one polyoxyalkylene
group as described in EP 663225.
[0166] Phase inversions generally occurs when the continuous phase
of a dispersion becomes the dispersed phase, or vice versa. Phase
inversions in liquid/liquid dispersions generally are known in the
art to be effected by one of two methods. An inversion may be
caused by changing the phase ratio until there is a high enough
ratio of the dispersed phase that it becomes the continuous phase.
Alternatively, a transitional inversions may occur when the
affinity of the surfactant for the two phases is altered in order
to cause the inversion. Typically, the inversions occurring in this
invention occur due to a change in the phase ratio.
[0167] Thus, the inversion method used to make emulsions, according
to the invention, is carried out by forming an oil phase containing
the diluted polysiloxane containing polymer and mixing and
agitating the oil phase. A limited and very small amount of water
is added to the oil phase in a stepwise fashion, such that an
inversion occurs, and an oil-in-water emulsion is formed.
Generally, the amount of water required is about 0.5 to 10 percent
by weight based on the cumulative weight of polysiloxane containing
polymer present in the oil phase. Preferably, the amount of water
will be about 1 to 5 percent by weight based on the weight of the
polysiloxane containing polymer present in the oil phase. While the
water can be added in 2 to 4 portions, addition of water in a
single portion is preferred. The initial addition of water can
include the surfactant. After the desired particle size has been
reached, the emulsion is diluted with the balance of water to
achieve the preferred solids content.
[0168] The emulsions produced by the process of this invention can
have a wide variety of polysiloxane containing polymer
concentrations, particle sizes and molecular weights, including
novel materials having high concentrations of large particle
polysiloxane containing polymer of high molecular weight. The
particle size can for example be chosen within the range 0.1 to
1000 micrometres.
[0169] The quantity of water and/or surfactant used in the initial
phase inversion process may have an impact on the particle size of
the final emulsion. For instance, if an emulsion is formed with the
same quantity of water in two instances but in the first a large
quantity of water is mixed before the phase inversion step and in
the second a small quantity of water is mixed before the phase
inversion step followed by mixing the remaining additional water
after the phase inversion step, the first emulsion will generally
have a larger particle size than the second. No matter how the
water is added, the total amount of water used is generally between
about 1 and 99 wt. %, preferably between about 6 and about 99 wt.
%, based on the weight of the emulsion.
[0170] If desired, other materials can be added to either phase of
the emulsions, for example, colorants, thickeners, preservatives,
freeze thaw stabilizer, inorganic salts to buffer pH, or active
ingredients such as pharmaceuticals.
[0171] Alternatively the foam control agent can be provided as a
water-dispersible composition in which the product resulting from
the process in accordance with the present invention is dispersed
in a water-dispersible component such as a silicone glycol or in
another water-miscible liquid such as ethylene glycol, propylene
glycol, polypropylene glycol, polyethylene glycol, a copolymer of
ethylene glycol and propylene glycol, an alkyl polyglycoside, an
alcohol alkoxylate or an alkylphenol alkoxylate.
[0172] An alternative form of providing a foam control agent
according to the present invention is in powdered or granulated
form. This is particularly useful when the agent is to be used in a
powdered product, e.g. a detergent powder. Any suitable method for
the production of powdered or granulated foam control agents may be
used with foam control agents produced using the method of the
present invention. Granulated foam control agents may, for example,
be made by a variety of methods, including granulators, spray
drying, emulsification followed by drying, spray mixing, spray
chilling, compactors, extruders, high shear mixing, low shear
mixing and flaking. Such methods have been extensively described in
the patent literature and these are exemplified by an extensive
list of publications in U.S. Pat. No. 6,521,587.
[0173] Suggested ingredients of particulate foam control agents
include, in addition to the foam control agent itself, a binder or
encapsulant and a carrier or support for the granule. It is
preferred that any carrier or binder material should contribute to
the efficiency or activity of the product in which it is to be
incorporated. A surfactant may be used to aid dispersion of the
silicone and organic liquid in the encapsulant or binder. Sometimes
other ingredients are incorporated, for example dyes, pigments,
preservatives or materials to aid the dispersion in the aqueous
medium in which the foam control agent is supposed to be active
such as the surfactants described above in connection with foam
control emulsions. Such a surfactant may help in controlling the
"foam profile", that is in ensuring that some foam is visible
throughout the wash without overfoaming.
[0174] Binders and/or encapsulants used in particulate foam control
agents may comprise waxes and/or aqueous film forming polymers.
Examples include dextrine, polypeptides, polyoxyalkylene polymers
such as polyethylene glycol, which can be applied molten or as an
aqueous solution and spray dried, reaction products of tallow
alcohol and ethylene oxide, or polypropylene glycol,
polycarboxylates, for example polyacrylic acid or a partial sodium
salt thereof or a copolymer of acrylic acid, for example a
copolymer with maleic anhydride, cellulose ethers, particularly
water-soluble or water-swellable cellulose ethers such as sodium
carboxymethylcellulose, gelatin, agar, microcrystalline waxes,
fatty acids or fatty alcohols having 12 to 20 carbon atoms and a
melting point in the range 45 to 80.degree. C., a monoester of
glycerol and such a fatty acid, a mixture of a water insoluble wax
having a melting point in the range from above 55.degree. C. to
below 100.degree. C. and a water-insoluble emulsifying agent,
glucose or hydrogenated glucose. A binder which is an organic
compound having a melting point of from about 40 to 80.degree. C.
and which in its liquid form is miscible with the polysiloxane
containing polymer so as to form a homogeneous liquid which upon
cooling forms a monophasic wax-like substance (that is a material
which is homogeneous and shows no phase separation during the
process or on storage of the granules) has the advantage of
producing encapsulated antifoam granules of improved storage
stability.
[0175] The surfactant used to disperse the silicone in the binder
or encapsulant can be selected from the surfactants described above
in connection with foam control emulsions. Silicone glycols are
preferred for many binders, or fatty alcohol ether sulphate or
linear alkylbenzene sulphonate may be preferred with a polyacrylic
acid binder. The surfactant can be added to the silicone undiluted
or in emulsion before the silicone is mixed with the binder, or the
surfactant and silicone can successively be added to the
binder.
[0176] Examples of carriers and/or supports are zeolites, for
example Zeolite A or Zeolite X, other aluminosilicates or
silicates, for example magnesium silicate, phosphates, for example
powdered or granular sodium tripolyphosphate, sodium sulphate,
sodium carbonate, sodium perborate, a cellulose derivative such as
sodium carboxymethylcellulose, granulated starch, clay, sodium
citrate, sodium acetate, sodium bicarbonate and native starch.
[0177] The foam control agents prepared in accordance to the method
of the invention are useful for reducing or preventing foam
formation in aqueous systems, particularly foam generated by
detergent compositions during laundering, and are particularly
useful in detergent compositions which have a high foaming
characteristic, for example those based on high levels of anionic
surfactants, e.g. sodium dodecyl benzene sulphonate to ensure
effectiveness of detergent composition at lower washing
temperatures, e.g. 40.degree. C.
[0178] According to another aspect of the invention a detergent
composition comprises (1) 100 parts by weight of a detergent
component and (2) from 0.02 to 5 parts by weight of a foam control
agent according to the first aspect of the invention.
[0179] Suitable detergent components comprise an active detergent,
organic and inorganic builder salts and other additives and
diluents. The active detergent may comprise organic detergent
surfactants of the anionic, cationic, non-ionic or amphoteric type,
or mixtures thereof. Suitable anionic organic detergent surfactants
are alkali metal soaps of higher fatty acids, alkyl aryl
sulphonates, for example sodium dodecyl benzene sulphonate, long
chain (fatty) alcohol sulphates, olefine sulphates and sulphonates,
sulphated monoglycerides, sulphated esters, sulphonated or
sulphated ethoxylated alcohols, sulphosuccinates, alkane
sulphonates, phosphate esters, alkyl isethionates, alkyl taurates
and alkyl sarcosinates. Suitable cationic organic detergent
surfactants are alkylamine salts, quaternary ammonium salts,
sulphonium salts and phosphonium salts. Suitable non-ionic organic
surfactants are condensates of ethylene oxide with a long chain
(fatty) alcohol or fatty acid, for example O.sub.14-15 alcohol,
condensed with 7 moles of ethylene oxide (Dobanol.RTM. 45-7),
condensates of ethylene oxide with an amine or an amide,
condensation products of ethylene and propylene oxides, sucrose
esters, fluorosurfactants, fatty acid alkylol amides and fatty
amine oxides. Suitable amphoteric organic detergent surfactants are
imidazoline compounds, alkylaminoacid salts and betaines. Examples
of inorganic components are phosphates and polyphosphates,
silicates, such as sodium silicates, carbonates, sulphates, oxygen
releasing compounds, such as sodium perborate and other bleaching
agents and zeolites. Examples of organic components are
anti-redeposition agents such as carboxymethylcellulose (CMC),
brighteners, chelating agents, such as ethylene diamine tetraacetic
acid (EDTA) and nitrilotriacetic acid (NTA), enzymes and
bacteriostats. Liquid detergent compositions may contain solvents,
alkanolamines, pH adjusting agents, opacifiers, perfumes, dyes,
colour stabilisers, bactericides, brighteners, soil release agents
and/or softening agents.
[0180] The foam control agents are particularly useful in detergent
compositions, for e.g. domestic laundering, dishwashing
applications but may also be employed in personal care type
applications such as hand wash applications and no rinse softeners
such processes as paper making and pulping processes, textile
dyeing processes, sewage treatment applications, cutting oil,
coatings and other aqueous systems where surfactants may produce
foam.
[0181] The emulsions and/or dispersions of the present invention
can generally have a silicone loading in the range of about 1 to
about 94 wt. %.
EXAMPLES
[0182] The following Examples are provided so that one skilled in
the art will more readily understand the invention. Viscosity
measurements of the polymer products were carried out using a
Brookfield Viscometer, spindle 6, at 10 rpm. Unless otherwise
indicated, all parts and percents are by weight and all viscosities
are at 25.degree. C.
Example 1
[0183] A silicone-based foam control agent was prepared by
polymerizing 50 parts by weight of dimethyl hydroxyl terminated
polydimethylsiloxane having a viscosity of 72 mPas in 50 parts by
weight of Hydroseal.RTM. G 250H (sold by Total Belgium of Brussels
Belgium) using 2.4 parts by weight of DBSA. The polymerization was
stopped once a viscosity of 52000 mPas was reached by the addition
of 1.54 parts of triethanolamine (TEA).
[0184] Subsequent to completion of the reaction components silica
(b) and, if required, resin (c) where introduced into the resulting
product
b) 4% by weight of Sipernat.RTM. D10 (sold by Degussa GmbH); a
commercially available precipitated silica with a surface area of
200g/m.sup.2 which has been hydrophobically treated; c) 3% by
weight of an organosilicon resin having an M:Q ratio of 0.65:1. The
organosilicon resin was introduced into the composition, in a
trimethylsilyl terminated polydimethylsiloxane having a viscosity
of 1000 mPas at 25.degree. C. in a resin:siloxane ratio of
25:75.
[0185] Emulsified foam control compositions containing (b) alone or
alternatively (b) in combination with (c) above were prepared using
the following process:
[0186] 105 parts of the appropriate foam control composition were
placed in suitable receptacle and heated to 60.degree. C. A mixture
of 9.3 parts of Volpo.RTM. S2 and 9.3 parts of Volpo.RTM. S20 (sold
by Croda Nev.) surfactants was preheated to 60.degree. C. and mixed
in with the foam control composition.
[0187] A mixture [M] consisting of
0.76 parts of xanthan gum (used as a thickener), 2.32 parts of
Natrosol.RTM. 250LR, (a hydroxyethylcellulose sold by the Aqualon
Division of Hercules Inc of USA) 0.16 parts of sorbic acid, 0.32
parts of benzoic acid, 0.77 parts of a 10% solution of sulfuric
acid and 95.66 parts of water was prepared.
[0188] The organic acids in the composition function as
preservatives and sulphuric acid is used as a preservative and as a
pH controlling agent.
[0189] 45 parts of mixture [M] was added to the receptacle and
after thorough mixing, another 112 parts of mixture [M] were added
and mixed in. Finally 219.5 parts of water were added resulting in
a suitable emulsion of the foam control composition.
Shaking Test--Sample Preparation
[0190] As a test of the capability of the resulting emulsions
samples were tested with a simple shaking test. A 1% by weight
solution of surfactant (as indicated below) in water was prepared
and 100 ml of the solution was placed in a 250 ml closed bottle. 10
.mu.l of the prepared antifoam composition emulsion was introduced
into the closed bottle to produce the sample to be tested. In Table
1 below the surfactants used were DBSA in samples 1A and 1B and
Triton.RTM. X-100 in Samples 1Cand 1D. Emulsions 1A and 1C
contained silica but no resin. Emulsions 1B and 1D contained both
silica and resin.
Shaking Test--Test Procedure
[0191] The bottle containing a sample prepared as described above
was shaken using a commercial shaker for periods of 8, 32, 48 and
96 seconds at 400 strokes per minute. After shaking the following
were observed:-- [0192] foam level (0-100%). This is the percentage
of the original free space in the container filled with foam after
shaking for the period indicated in Table 1a. [0193] collapse time
to 10%-this is the time taken for the foam to collapse back to 10%
of the volume of free space in the container before shaking
commences for the period indicated in the Table. 1a
TABLE-US-00001 [0193] TABLE 1 a Sample 1A Shaking 8 s 32 s 48 s 96
s Foam Height (%) 50 75 100 100 Collapse 10% (s) 6 10 19 78 1B
Shaking 8 s 32 s 48 s 96 s Foam Height (%) 75 100 100 100 Collapse
10% (s) 80 97 90 80 1C Shaking 8 s 32 s 48 s 96 s Foam Height (%)
25 50 50 75 Collapse 10% (s) 22 41 50 41 1D Shaking 8 s 32 s 48 s
96 s Foam Height (%) 25 50 50 75 Collapse 10% (s) 27 20 21 26
Granulation
[0194] A granulated foam control agent was prepared using a foam
control agent prepared in accordance to the method of the present
invention in Example 1 which incorporated both (b) Sipernat.RTM.
D10 and (c) the organosilicon resin. using the following process:
63 g of an acrylic/maleic copolymer sold as Sokalan.RTM. CP5 from
BASF was initially added to 42 g of water whilst mixing. Once the
resulting mixture was homogeneous 12 g of DBSA and 37 g of the foam
control agent prepared above was added whilst mixing continued. The
resulting mixture was then added to zeolite powder in an
agglomeration mixer until a desired average granule particle size
was achieved (typically 55 g of liquid on 100 g of powder). The
resulting granular products were dried in a fluid bed to remove the
excess water and classified to remove any undesirable fines or
oversized granules.
[0195] The resulting granulated product was tested in a standard
European style front loading washing machine (Miele.RTM.) which was
loaded with 2.5 kg of clean cotton fabric. The wash tests were
carried out at 40.degree. C. using 14 liters of water (hardness of
19.degree. F.) per wash.
[0196] The detergent composition used comprised:
6.9 parts by weight of sodium dodecylbenzenesulfonate anionic
surfactant (Maranil paste A sold by Cognis) 5.1 parts by weight of
nonionic surfactants (dehydrol LT7 sold by Cognis) 42.9 parts by
weight of zeolite 4A 5.1 parts by weight of sodium sulphate 15
parts by weight of sodium carbonate 15 parts of by weight of sodium
perborate tetrahydrate
[0197] The granulated antifoam was added in an amount of 0.4% by
weight of the detergent composition, to 90 g of the detergent
powder. The foam height of foam was observed every 5 minutes
throughout each wash test (0=no foam, 50=half window of foam,
100=full window of foam). The results are shown in Table 1b
below:
TABLE-US-00002 TABLE 1b Time (min.) 0 5 10 15 20 25 30 35 40 45 50
55 60 Foam 0 0 0 0 0 0 15 40 60 75 85 95 100 Height %
Example 2
[0198] A silicone-based foam control agent was prepared by
polymerizing 50 parts by weight of dimethyl hydroxyl terminated
polydimethylsiloxane having a viscosity of 72 mPas in 50 parts by
weight of trimethylsilyl terminated polydimethylsiloxane (100 mPas)
using 2.4 parts by weight of DBSA in the presence of 3 parts by
weight of Sipernat.RTM. D10. The polymerization was stopped once a
viscosity of 38000 mPas was reached by the addition of 1.5 g of
TEA.
[0199] Subsequent to completion of the reaction component samples
of the resulting product were tested using the shaking method
described in Example 1.
[0200] In Table 2 below the surfactant used was DBSA in Samples 2A
and Triton.RTM. X-100 in Sample 2B.
TABLE-US-00003 TABLE 2 Sample 2A Shaking 8 s 32 s 48 s 96 s Foam
height (%) 100 75 100 100 Collapse 10% (s) 10 7 9 15 2B Shaking 8 s
32 s 48 s 96 s Foam height (%) 50 50 50 75 Collapse 10% (s) 6 6 9
30
[0201] A granular form of the foam control agent produced in
accordance with the present invention was prepared by the method
described in Example 1.
Example 3
[0202] A silicone-based foam control agent was prepared by
polymerizing 48.5 parts by weight of dimethyl hydroxyl terminated
polydimethylsiloxane having a viscosity of 72 mPas in 48.5 parts by
weight of an organic extender (Hydroseal G250H) using 2.4 parts by
weight of DBSA in the presence of 3 parts by weight of
Sipernat.RTM. D10. The polymerization was stopped once a viscosity
of 68000 mPas was reached by the addition of 1.5 parts by weight of
TEA.
[0203] Subsequent to completion of the reaction component samples
of the resulting product were tested using the shaking method
described in Example 1.
[0204] In Table 3 below DBSA was the surfactant used in Sample 3A
and the surfactant used in Sample 3B was Triton.RTM. X-100.
TABLE-US-00004 TABLE 3 Sample 3A Shaking 8 s 32 s 48 s 96 s Foam
height (%) 100 100 100 100 Collapse 10% (s) 90 10 14 54 3B Shaking
8 s 32 s 48 s 96 s Foam height (%) 25 25 50 75 Collapse 10% (s) 5 7
7 18
[0205] A granular form of the foam control agent produced in
accordance with the present invention was prepared by the method
described in Example 1.
Comparative Example 1
[0206] In order to assess the foam control of products prepared in
accordance with the process of the present invention, emulsions of
two commercial antifoams, Dow Corning.RTM. DB 100 and Dow
Corning.RTM. 3990 (sold by Dow Corning Corporation of Michigan,
USA) were prepared using the method described in example 1 above.
The samples prepared were analysed using the shake test described
in example 1 above and the results are provided below in Table
CE1.
TABLE-US-00005 TABLE CE1 Antifoam Surfactant DB-100 DBSA Shaking 8
s 32 s 48 s 96 s Foam height 60 100 100 100 (%) Collapse 10%
>120 >120 >120 >120 (s) 3990 DBSA Shaking 8 s 32 s 48 s
96 s Foam height 50 75 75 100 (%) Collapse 10% >120 13 29 60 (s)
DB-100 Triton .RTM. Shaking 8 s 32 s 48 s 96 s X-100 Foam height 50
50 60 75 (%) Collapse 10% >120 30 29 31 (s) 3990 Triton .RTM.
Shaking 8 s 32 s 48 s 96 s X-100 Foam height 50 50 50 60 (%)
Collapse 10% >120 17 19 27 (s)
[0207] Whilst production costs of materials prepared in accordance
with the present invention are significantly lower than for the
commercial products tested, it was found that the foam control
provided by the compositions prepared in accordance with the
present invention was comparable and in some instances better than
the foam control achieved when testing commercial products
tested.
Example 4
[0208] 5 different samples of foam control agents were prepared in
accordance with the process of the present invention and these were
subsequently compared with the performance of a commercial antifoam
product Dow Corning.RTM. 3990
Step A
[0209] Mixtures of diluents in the following proportions were
prepared for the respective samples 4a-4-c a) 405.4 parts by weight
of parts by weight of trimethylsilyl terminated
polydimethylsiloxane (1000 mPas) and 1125 parts by weight of
Hydroseal.RTM. G250H; b) 280.4 parts by weight of trimethylsilyl
terminated polydimethylsiloxane (1000 mPas) and 250 parts by weight
of Hydroseal.RTM. G250H; c) 155.4 parts by weight of trimethylsilyl
terminated polydimethylsiloxane (1000 mPas) and 375 parts by weight
of Hydroseal.RTM. G250H; and
[0210] Step B Foam control compositions (Samples 4a-4c) were
prepared by mixing: [0211] .+-.530.4 parts of the respective
mixture prepared in Step A [0212] 32 parts of Sipernat D10 [0213]
228.4 parts of a dimethylvinylsiloxane end-blocked polydimethyl
siloxane having a viscosity of 9000 mPas, [0214] 2.0 parts of a
trimethylsiloxane end-blocked copolymer of dimethylsiloxane units
and methylhydrogensiloxane units, having a viscosity of about 7
mPas and 0.3% by weight of Si--H groups [0215] 6.4 parts of a 24%
mixture of resinous polyorganosiloxane having a molecular weight of
about 13,000 and trimethyl siloxy end-groups and 69% of a trimethyl
end-blocked polydimethyl siloxane having a viscosity of 1000 mPas,
[0216] 0.8 parts of a catalyst which was a chloroplatinic acid
complex of divinyltetramethyldisiloxane diluted in 70% by weight of
dimethylvinylsiloxy endblocked polydimethylsiloxane.
[0217] In step B the ingredients were mixed (Hauschild Speedmixer)
and left to react at a temperature of 60.degree. C. for 1 hour. The
resulting mixture was homogenised before 200 parts of trimethyl
siloxane end-blocked polydimethyl siloxane having a viscosity of
1000 mPas and containing 0.45% by weight of 1-ethynylcyclohexanol
were added into the compound.
Foam Cell Tests
[0218] The resulting products and the comparative were emulsified
as described in Example 1 and their respective performance was
analysed by means of a so-called "foam cell test";
Test Conditions
[0219] The emulsified foam control compositions were tested in a
foam cell using a softwood liquor. To this effect 600 ml of
softwood liquor is preheated at 90.degree. C. and introduced in a
graduated and thermostatically controlled glass cylinder having an
inner diameter of 5 cm. This foamable liquid was circulated through
a circulation pipe at a temperature adjusted to 89.degree. C. The
circulation flow rate is controlled using a MDR Johnson pump set up
at a frequency of 50 Hz. When the foam height of 30 cm is reached,
150 .mu.l of emulsion of the tested foam control composition is
injected in the liquid jet. The evolution of the foam height was
monitored and recorded. The foam height was measured in cm over a
sufficient period to allow the foam control composition to have
exhausted its capacity, which is when the foam height of 29 cm has
been reached again in the foam cell, and the time at which this
occurred was measured as it indicates the longevity of the foam
control composition.
Results
Table 4 is a Measure of Foam Height (FH) in Cm Against Time for a
(Comparative) Commercial Product and Examples 4A to 4C as Described
Above.
TABLE-US-00006 [0220] TABLE 4 FH (cm) FH (cm) FH (cm) FH (cm) Time
(sec) CP 4a 4b 4c 0 30 30 30 30 10 15.5 25 26 28 20 14.5 21 19 25
30 22.5 19.5 18.5 21.5 40 19 21 18 20 50 18.5 20.5 19 20.5 60 20
22.5 19.5 20.5 70 20.5 23.5 22.5 21.5 80 20.5 24.5 24.5 24 90 22 24
25.5 25.5 100 22.5 25 25 25.5 110 24.5 25.5 25.5 26 120 25.5 26 26
26 130 24.5 25.5 25.5 26.5 140 25 25.5 24.5 26 150 26.5 26 26.5
27.5 160 25.5 26.5 25 25.5 170 26.5 26.5 25.5 24.5 180 27 27 26.5
25 190 27.5 27.5 26.5 25.5 200 28.5 27.5 27.5 26 210 28.5 28 27.5
26.5 220 28.5 28 26.5 230 28.5 28.5 27 240 28.5 28.5 27.5 250 29
28.5 28.5 260 28.5 28.5 270 29 28.5 280 28.5 290 28.5 P300 29
[0221] It was identified that the maintenance of foam control was
comparable and in some instances even better than the comparative
commercial material tested.
* * * * *