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DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a silicone emulsion composition. More
particularly, the present invention relates to a cationic emulsion
composition of a polydiorganosiloxane containing amino, epoxy and hydroxyl
groups as functional groups.
The polyorganosiloxane emulsion compositions are used as a releasing agent,
stripping agent, paint component, and anti-foam agent. In addition, they
are used widely for the treatment of papers, fibers, and glasses.
An organopolysiloxane latex composition obtained by the emulsion
polymerization of a cyclic organosiloxane in the presence of an
organotrialkoxysilane containing an amino, epoxy, or mercapto group as a
functional group coupling agent has been proposed as a one-package type
emulsion composition having an excellent film-forming property (Japanese
Patent Laid-Open No. 131661/1979). It has been reported that this
composition is preferred particularly as a finishing agent for fibers or
as a treating agent for papers and fibers. However, in case the
organoalkoxysilane contains an amino group as the functional group and the
amount thereof is large, a yellowing phenomenon occurs in the course of
the heat treatment of the fibers or papers. Further, if the
organotrialkoxysilane containing an amino or epoxy group as the functional
group is used in a large relative amount, gelation occurs during the
emulsion polymerization due to its strong hydrolyzability, and, in
addition, the stability of the emulsion per se is deteriorated by an
alcohol formed by the hydrolysis. On the other hand, if the relative
amount of the organotrialkoxysilane having an amino group or the like as
the functional group is insufficient and the ratio of the functional group
to the total emulsion composition is insufficient, the adhesion of the
composition to a base is reduced. If the amount of the
organotrialkoxysilane is less than 1%, the effects thereof cannot be
exhibited.
After intensive investigation made for the purpose of overcoming these
defects of the conventional processes, the inventor has succeeded in
obtaining a silicone emulsion composition free of the above defects by
reacting a reaction product of an amino group-containing silane and an
epoxy group-containing silane as a silane derivative with a silanol
group-containing polydiorganosiloxane and emulsion-polymerizing the
reaction product with a cyclic organosiloxane. The present invention has
been completed on the basis of these findings.
An object of the present invention is to provide a silicone emulsion
composition having excellent film-forming ability, adhesion, and stability
and suitable for use particularly in the treatment of fibers and papers.
SUMMARY OF THE INVENTION
The composition of the present invention is a silicone emulsion composition
obtained by emulsion-polymerizing:
(1) 0.1-60 weight percent of a reaction product of (A) 50-99.9 weight
percent of a polydiorganosiloxane having at least one silanol group in the
molecule and a viscosity at 25.degree. C. of 5-10,000 cSt, and (B) 0.1-50
weight percent of a product obtained by reacting (a) 1 mole of an amino
group-containing silane with (b) 0.5-3.0 mole of an epoxy group-containing
silane, with
(2) 1-50 weight percent of a cyclic organosiloxane in the presence of:
(3) 0.1-20 weight percent of a quaternary ammonium salt surfactant, and
(4) 20-90 weight percent of water.
DESCRIPTION OF THE INVENTION
The polydiorganosiloxane (A) used as the starting material of the reaction
product (1) constituting the composition of the present invention has at
least one silanol group in the molecule and a viscosity at 25.degree. C.
of 5-10,000 cSt, preferably 50-1,000 cSt. If the polydiorganosiloxane has
a viscosity at 25.degree. C. of less than 5 cSt, i.e. a low molecular
weight, the silanol group content becomes too large and a reaction product
thereof with (B) has reduced stability. For the same reasons as above, the
stability of a reaction product thereof with (B) is reduced a little also
when the viscosity is less than 50 cSt. On the other hand, if the
viscosity is higher than 1,000 cSt, a reaction product thereof with (B)
has an excessive viscosity, and the emulsification thereof becomes
difficult. If the viscosity is higher than 10,000 cSt this phenomenon
becomes remarkable, and the relative amount of (B) in the composition is
reduced due to the reduction in amount of the terminal silanol group and
also due to compound (2) required in a large amount for reducing the
viscosity of the system, whereby the intended excellent film cannot be
obtained.
As the organic group bonded with the silicon atom in the
polydiorganosiloxane (A), there may be mentioned, for example, an alkyl
group such as methyl, ethyl, butyl, hexyl, decyl or dodecyl group, an
aralkyl group such as beta-phenylethyl or beta-phenylpropyl group, phenyl
group or vinyl group. From the viewpoint of ease of the synthesis of the
polydiorganosiloxane, a methyl or phenyl group is preferred, and among
them, methyl is particularly preferred. The polydiorganosiloxane (A)
contains at least one silanol group in the molecule. Preferably the
polydiorganosiloxane is blocked with silanol groups at both terminals
thereof. As particular examples of (A) there may be mentioned a
polydimethylsiloxane blocked with silanol group at one terminal and
trimethylsilyl group at the other; polydimethylsiloxane blocked with
silanol groups at both terminals; and polymethylphenylsiloxane blocked
with silanol groups at both terminals.
The component (B) used as the other starting material of component (1) is a
reaction product of components (a) and (b). The component (a) is an amino
group-containing silane of formula (I):
##STR1##
wherein Q.sup.1 represents a monovalent group selected from the group
consisting of hydrogen atom, --CH.sub.3, --CH.sub.2 CH.sub.2 NH.sub.2 and
--CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2, R.sup.1 represents a
divalent hydrocarbon group having 1-4 carbon atoms, R.sup.2 and R.sup.3
each represent a monovalent hydrocarbon group having 1-4 carbon atoms and
a represents an integer of 0 or 1. As the divalent hydrocarbon group
R.sup.1 having 1-4 carbon atoms in the above formula (I), there may be
mentioned, for example, methylene, ethylene, propylene or butylene. As the
monovalent hydrocarbon group R.sup.2 or R.sup.3 having 1-4 carbon atoms,
there may be mentioned, for example, methyl, ethyl, n-propyl, isopropyl,
n-butyl or isobutyl. As the amino group-containing silane, there may be
mentioned, for example, gamma-aminopropyltriethoxysilane,
gamma-aminopropylmethyldiethoxysilane,
N-(beta-aminoethyl)aminomethyltrimethoxysilane,
gamma-[N-(beta-aminoethyl)amino]propyltrimethoxyysilane,
gamma-[N-(beta-aminoethyl)amino] propylmethyldimethoxysilane,
N-(beta-aminoethyl)aminoethyltributoxysilane or
gamma-[N-(beta-(N-beta-aminoethyl)amino)ethyl)amino]
propyltrimethoxysilane.
The component (b) is an epoxy group-containing silane of formula (II):
##STR2##
wherein Q.sup.2 represents an epoxy group-containing group selected from
the group consisting of glycidoxy and epoxycyclohexyl groups, R.sup.4
represents a divalent hydrocarbon group having 2-4 carbon atoms, R.sup.5
and R.sup.6 each represent a monovalent hydrocarbon group having 1-4
carbon atoms and b represents an integer of 0 or 1. As the divalent
hydrocarbon group R.sup.4 having 2-4 carbon atoms in the above formula
(II), there may be mentioned, for example, ethylene, propylene or
butylene. As the monovalent hydrocarbon group R.sup.5 or R.sup.6 having
1-4 carbon atoms, there may be mentioned, for example, methyl, ethyl,
n-propyl, isopropyl, n-butyl or isobutyl.
As particular examples of the epoxy group-containing silanes, there may be
mentioned gamma-glycidoxypropyltrimethoxysilane,
gamma-glycidoxypropylmethyldimethoxysilane,
beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,
beta-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane,
beta-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and
beta(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane.
The component (B) is prepared by reacting 1 mole of component (a) with
0.5-3.0 mole, preferably 0.75-1.5 mole, of component (b). The reaction is
carried out generally by mixing components (a) and (b) and heating the
mixture to 20.degree.-80.degree. C. under stirring. The reaction product
of components (a) and (b) may contain a small amount of unreacted
components. If the component (b) is used in an amount of less than 0.5
mole or more than 3.0 mole per mole of the component (a), the amount of
one of the silane compounds to be reacted becomes insufficient and,
therefore, the reaction mixture formed by the reaction of (a) and (b)
contains only a reduced amount of the reaction product having a high
functional group content, whereby the desired cross-linked structure
cannot be obtained.
The component (1) is obtained by reacting the above-mentioned components
(A) and (B) by an ordinary method. The components (A) and (B) are used in
a proportion of 50-99.9 weight percent to 0.1-50 weight percent
respectively to (1). If the amount of component (B) is less than 0.1
weight percent to (1), adhesive film does not form. If the amount of
component (B) exceeds 50 weight percent to (1), the reaction product of
(A) and (B) has a low stability and it gels in the course of the reaction
in some cases. As for the reaction conditions, for example, the components
(A) and (B) are charged in a reactor, and the reaction is carried out at
40.degree.-60.degree. C. in nitrogen stream for 1-5 hours.
The amount of component (1) to the composition is 0.1-60 weight percent,
preferably 1-30 weight percent. If the amount of component (1) is less
than 0.1 weight percent, film which has excellent adhesion properties does
not form. And if the amount of component (1) exceeds 60 weight percent,
the composition cannot be easily emulsified.
The component (2) used as another starting material of the composition of
the present invention is a cyclic organosiloxane of formula (III):
##STR3##
wherein R.sup.7 and R.sup.8 may be the same or different, and each
represent a substituted or unsubstituted hydrocarbon group having 1-50
carbon atoms and n represents an integer of at least 3. As groups R.sup.7
and R.sup.8, there may be mentioned, for example, straight or branched
alkyl groups (such as methyl, ethyl, hexyl, octyl, decyl, hexadecyl and
octadecyl groups); alkenyl or dienyl groups (such as vinyl, allyl and
butadienyl groups); aryl groups (such as phenyl, naphthyl and xenyl
groups); and aralkyl groups (such as benzyl, beta-phenylethyl,
methylbenzyl and naphthylmethyl groups). As the substituent of the
hydrocarbon group, there may be mentioned a halogen atom such as fluorine
or chlorine or cyano group.
The amount of component (2) to the composition is 1-50 weight percent,
preferably 5-30 weight percent. If the amount of component (2) is less
than 1 weight percent or more than 50 weight percent, the composition
cannot be easily emulsified, and an emulsion after polymerization is not
stable. From the viewpoint of stability of emulsion, total amount of
components (1) and (2) is preferably 20-60 weight percent of the
composition.
As the quaternary ammonium salt surfactant (3) used in the production of
the composition of the present invention, there may be mentioned, for
example, an alkyltrimethylammonium salt such as octadecyltrimethylammonium
chloride or hexadecyltrimethylammonium chloride; a dialkyldimethylammonium
salt such as dioctadecyldimethylammonium chloride,
dihexadecyldimethylammonium chloride or didodecyldimethylammonium chloride
and a benzalkonium chloride such as octadecyldimethylbenzylammonium
chloride or hexadecyldimethylbenzylammonium chloride.
The amount of component (3) in the composition is 0.1-20 weight percent,
preferably 0.5-8 weight percent. If the amount of the component (3) is out
of this range, a good emulsified state cannot be obtained.
The amount of component (4), water, in the composition is 20-90 weight
percent, preferably 40-80 weight percent. If the amount is out of this
range, a stable emulsion cannot be formed.
The composition of the present invention is obtained by mixing the
components (1), (2), (3), and (4) together to obtain a rough dispersion,
emulsifying them by means of an emulsifying machine such as a colloid mill
or a homogenizer to obtain a homogeneous emulsion and subjecting the same
to the emulsion polymerization under heating with stirring. The emulsion
polymerization reaction is usually preferably carried out in the presence
of an emulsion polymerization catalyst. It is particularly preferred to
use potassium hydroxide as the emulsion polymerization catalyst. An
excellent composition can be obtained by incorporating a nonionic
surfactant in the reaction system in addition to the above-mentioned
cationic surfactant. As the nonionic surfactant, there may be mentioned,
for example, a glycerol fatty acid ester, sorbitan fatty acid ester,
polyoxyethylene (hereinafter referred to as POE) alcohol ether, POE
sorbitan fatty acid ester, POE glycelol fatty acid ester, POE alkylphenol
ether or POE polyoxypropylene block copolymer. The emulsion polymerization
reaction is carried out generally at 30.degree.-90.degree. C., preferably
at 60.degree.-80.degree. C.
In case the composition of the present invention is used as a fiber
treating agent, the treatment is effected as follows: a cloth is immersed
in a solution of the composition in water, the cloth is squeezed, dried at
a given temperature for a given period of time, and, if necessary,
heat-treated.
As will be proved in the following examples, in comparison with the
comparative examples, the composition of the present invention thus
obtained has excellent film-forming ability, adhesion, and stability. This
silicone emulsion composition is suitable for use as a treating agent for
fibers and papers since it does not cause any yellowing of them.
The following examples and comparative examples will further illustrate the
present invention, which by no means limit the invention. In the examples
and comparative examples, parts means weight parts.
EXAMPLE 1
10 parts of a reaction product of equimolar amounts of
gamma-(N-beta-aminoethylamino)propyltrimethoxysilane and
beta-(3,4-epoxycyclohexyl)ethyltriethoxysilane were reacted with 90 parts
of polydimethylsiloxane blocked with silanol groups at both terminals and
having a viscosity at 25.degree. C. of 200 cSt at 80.degree. C. for 3
hours to obtain a colorless, transparent base oil A.
8 parts of base oil A, 27 parts of octamethylcyclotetrasiloxane, 5 parts of
dioctadecyldimethylammonium chloride, 59.5 parts of water, and 0.5 part of
potassium hydroxide were stirred together to obtain a mixture. The mixture
was emulsified by passing them through a colloid mill having a mill
distance of 10 mil. The resulting product was stirred under heating to
75.degree. C. for 3 hours. After cooling to 40.degree. C. under stirring,
it was neutralized with hydrochloric acid to obtain composition A-1.
EXAMPLE 2
15 parts of a reaction product of equimolar amounts of
gamma-aminopropyltriethoxysilane and
gamma-glycidoxypropylmethyldimethoxysilane were reacted with 85 parts of
polydimethylsiloxane blocked with silanol groups at both terminals and
having a viscosity at 25.degree. C. of 100 cSt at 80.degree. C. for 5
hours to obtain a colorless, transparent base oil B. 15 parts of the base
oil B, 20 parts of octamethylcyclotetrasiloxane, 5 parts of
dihexadecyldimethylammonium chloride, 59.5 parts of water and 0.5 part of
potassium hydroxide were stirred together and composition B-1 was obtained
in the same manner as in Example 1. 3 parts of sorbitan monolaurate was
added to 100 parts of composition B-1, and the mixture was stirred at room
temperature to obtain composition B-2.
EXAMPLE 3
10 parts of a reaction product of equimolar amounts of
gamma-aminopropyltriethoxysilane and
beta-(3,4-epoxycyclohexyl)ethyltriethoxysilane were reacted with 90 parts
of polydimethyldiphenylsiloxane blocked with silanol groups at both
terminals, comprising 10 mole % of diphenylsiloxy units and 90 mole % of
dimethylsiloxy units and having a viscosity at 25.degree. C. of 500 cSt at
80.degree. C. for 3 hours to obtain a colorless, transparent base oil C.
10 parts of the base oil C, 25 parts of a mixture of 72 weight percent of
octamethylcyclotetrasiloxane and 28 weight percent of
decamethylcyclopentasiloxane, 4 parts of dihexadecyldimethylammonium
chloride, 60.5 parts of water, and 0.5 part of potassium hydroxide were
stirred together to obtain a mixture. The mixture was emulsified by
passing them through a colloid mill having a mill distance of 10 mil. The
resulting product was stirred under heating to 70.degree. C. for 4 hours.
After cooling to 40.degree. C. under stirring, it was neutralized with
hydrochloric acid to obtain composition C-1.
COMPARATIVE EXAMPLE 1
2 parts of gamma-(N-beta-aminoethylamino)propyltrimethoxysilane was mixed
with 31 parts of octamethylcyclotetrasiloxane. 59.5 parts of water was
mixed with 7 parts of dihexadecyldimethylammonium chloride to obtain a
solution. The above-prepared silane-siloxane mixture was added dropwise to
the solution, and the whole was stirred. 0.5 part of potassium hydroxide
was added to the mixture. Passing them through a colloid mill (mill
distance: 10 mil), an emulsion was obtained, and then, the emulsion was
stirred under heating to 75.degree. C. for 3 hours. After cooling to
40.degree. C. under stirring, it was neutralized with hydrochloric acid to
obtain composition D.
COMPARATIVE EXAMPLE 2
Composition E was prepared from 4 parts of gamma-aminopropyltriethoxysilane
and 29 parts of octamethylcyclotetrasiloxane in the same manner as in
Comparative Example 1.
Compositions A-1, B-1, B-2, C-1, D and E obtained in the above examples and
comparative examples were used for the treatment of cloths to obtain
experimental data as shown in the following table. Effects of the
compositions as fiber-treating agents were evaluated using cloths treated
under the following treatment conditions:
Treating bath: Each composition diluted with water to 1/30 concentration
Cloth: Knitted cotton cloth
Treating method: The cloth once immersed in the bath was squeezed
(squeezing rate: 100%), dried at 120.degree. C. for 5 minutes and
heat-treated at 180.degree. C. for 11 minutes.
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Composition Color
Test Resilience
Slipperiness
Yellowing
Fastness
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A-1 Good Slight Not 5-4 Grade
caused
B-1 Good None Not 5-4 Grade
caused
B-2 Good None Not 4-5 Grade
caused
C-1 Good None Not 4-5 Grade
caused
D Good None Slight 4 Grade
yellowing
E Good None Yellowing
3 Grade
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Test method according to JIS L 0849. Resilience and slipperiness were
examined by means of fingers and yellowing was judged by visual
observation.
The compositions obtained in Examples 1 to 3 did not cause the yellowing of
the material and exerted no bad influence on the color fastness.
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