U.S. patent application number 14/152266 was filed with the patent office on 2014-08-14 for aqueous surface-treating agent.
This patent application is currently assigned to NOK Corporation. The applicant listed for this patent is NOK Corporation, NOK Kluber Co., Ltd.. Invention is credited to Toshihiro Higashira, Tetsuhiro Kitahara, Yoshifumi Kojima, Masaki Tahara.
Application Number | 20140228261 14/152266 |
Document ID | / |
Family ID | 40549087 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140228261 |
Kind Code |
A1 |
Tahara; Masaki ; et
al. |
August 14, 2014 |
AQUEOUS SURFACE-TREATING AGENT
Abstract
An aqueous surface-treating agent, which comprises a silicone
oil aqueous emulsion, a polyurethane resin aqueous emulsion, and a
silane compound represented by the following general formula:
##STR00001## (where R.sup.1 and R.sup.2 each are an alkyl group
having 1 to 4 carbon atoms, and n and m are 1.ltoreq.n.ltoreq.3 and
m=3-n, respectively), and/or a hydrolyzate thereof; wherein 100
parts by weight or more of the polyurethane resin in terms of the
weight of solid matters is used on the basis of 100 parts by weight
in terms of nonvolatile matters of silicone oil, can prevent
sticking of rubber seal materials such as O rings, etc. themselves
or sticking to a metal, a resin, etc., and can reduce the friction
of rubber or resin seal members at the time of sliding motion.
Inventors: |
Tahara; Masaki; (Ibaraki,
JP) ; Kitahara; Tetsuhiro; (Ibaraki, JP) ;
Higashira; Toshihiro; (Kanagawa, JP) ; Kojima;
Yoshifumi; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NOK Corporation
NOK Kluber Co., Ltd. |
Tokyo
Tokyo |
|
JP
JP |
|
|
Assignee: |
NOK Corporation
Tokyo
JP
NOK Kluber Co., Ltd.
Tokyo
JP
|
Family ID: |
40549087 |
Appl. No.: |
14/152266 |
Filed: |
January 10, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12681919 |
Apr 7, 2010 |
8658722 |
|
|
PCT/JP2008/062994 |
Jul 18, 2008 |
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14152266 |
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Current U.S.
Class: |
508/144 |
Current CPC
Class: |
C09D 183/04 20130101;
C10M 155/02 20130101; C09D 175/04 20130101; C09D 175/04 20130101;
C10M 2229/052 20130101; C08K 5/5419 20130101; C10M 149/12 20130101;
C08L 75/04 20130101; C08L 83/00 20130101; C09D 5/00 20130101; C10M
2217/045 20130101; C09D 183/04 20130101 |
Class at
Publication: |
508/144 |
International
Class: |
C10M 155/02 20060101
C10M155/02; C10M 149/12 20060101 C10M149/12 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 9, 2007 |
JP |
2007-263457 |
Jun 24, 2008 |
JP |
2008-164431 |
Claims
1-9. (canceled)
10: An aqueous surface-treating anti-adhesive agent, which
comprises a silicone oil aqueous emulsion, a polyurethane resin
aqueous emulsion, and a silane compound represented by the
following general formula: ##STR00006## (where R.sup.1 and R.sup.2
each are independently an alkyl group having 1-4 carbon atoms, n
and m are 1.ltoreq.n.ltoreq.3 and m=3-n respectively), and/or a
partial hydrolyzate thereof, wherein 100 parts by weight or more of
the polyurethane resin in terms of the weight of solid matters is
used on the basis of 100 parts by weight in terms of the weight of
nonvolatile matters of the silicone oil, wherein the polyurethane
resin aqueous emulsion is a mixture of (a) an aqueous emulsion
containing a hydrazide and a carbonyl group-containing polyurethane
resin, and (b) a silanol-modified polyurethane resin aqueous
emulsion wherein the silanol-modified polyurethane resin has, in
the polyurethane structure, silanol groups, which turn to siloxane
bonds by condensation cross-linking reaction after surface
treating, in a ratio by weight of solid matter sum total of
(a):(b)=5-95:95-10, and wherein when applied to rubber seal members
the anti-adhesive agent prevents sticking of the rubber seal
members to themselves and prevents sticking of the rubber seal
members to other materials.
11: An aqueous surface-treating anti-adhesive agent according to
claim 10, wherein 10-60 parts by weight of the silane compound
and/or a hydrolyzate thereof is used on the basis of 100 parts by
weight in terms of nonvolatile matters of the silicone oil.
12: An aqueous surface-treating anti-adhesive agent according to
claim 10, for application to the surfaces of rubber materials or
resin materials.
13: An aqueous surface-treating anti-adhesive agent according to
claim 12, wherein the rubber materials are seal materials.
14: A seal material surface-treated by an aqueous surface-treating
anti-adhesive agent according to claim 13.
15: An aqueous surface-treating anti-adhesive agent according to
claim 12, wherein the rubber materials are sliding members.
16: A sliding member surface-treated by an aqueous surface-treating
anti-adhesive agent according to claim 15.
17: A method for surface-treating rubber materials to prevent
sticking of the rubber materials to themselves and prevent sticking
of the rubber materials to other materials which method comprises:
a) providing an aqueous surface-treating anti-adhesive agent, which
comprises a silicone oil aqueous emulsion, a polyurethane resin
aqueous emulsion, and a silane compound represented by the
following general formula: ##STR00007## (where R.sup.1 and R.sup.2
each are independently an alkyl group having 1-4 carbon atoms, n
and m are 1.ltoreq.n.ltoreq.3 and m=3-n respectively), and/or a
partial hydrolyzate thereof, wherein 100 parts by weight or more of
the polyurethane resin in terms of the weight of solid matters is
used on the basis of 100 parts by weight in terms of the weight of
nonvolatile matters of the silicone oil, wherein the polyurethane
resin aqueous emulsion is a mixture of (a) an aqueous emulsion
containing a hydrazide and a carbonyl group-containing polyurethane
resin, and (b) a silanol-modified polyurethane resin aqueous
emulsion wherein the silanol-modified polyurethane resin has, in
the polyurethane structure, silanol groups, which turn to siloxane
bonds by condensation cross-linking reaction after surface
treating, in a ratio by weight of solid matter sum total of
(a):(b)=5-95:95-10, and wherein when applied to rubber seal members
the anti-adhesive agent prevents sticking of the rubber seal
members to themselves and prevents sticking of the rubber seal
members to other materials; and (b) surface-treating rubber
materials with the aqueous surface-treating anti-adhesive agent.
Description
RELATED APPLICATION
[0001] This application is a continuation application of U.S.
patent application Ser. No. 12/681,919, filed Apr. 7, 2013 which in
turn was a 35 U.S.C. .sctn.371 national phase filing of
International Patent Application No. PCT/JP2008/062994, filed Jul.
18, 2008. Priority is claimed under 35 U.S.C. .sctn.120 to U.S.
patent application Ser. No. 12/681,919 and to International Patent
Application No. PCT/JP2008/062994. Priority is further claimed
under 35 U.S.C. .sctn.119 to Japanese Patent Application Nos.
2007-263457, filed Oct. 9, 2007 and 2008-164431, filed Jun. 24,
2008.
TECHNICAL FIELD
[0002] The present invention relates to an aqueous surface-treating
agent, and more particularly to an aqueous surface-treating agent
effectively applicable to surfaces of rubber seal materials,
etc.
BACKGROUND ART
[0003] Most of now available rubber seal materials suffer from
sticking problems between seal materials themselves or sticking to
contact surfaces of mating materials such as metals, resins, etc.,
when assembled into equipment. To overcome such problems, a liquid
material such as wax, grease, lubricating oil, etc. is applied to
the seal materials, thereby improving the assembling work.
[0004] When rubber parts such as O rings, etc. are transported by a
parts feeder to conduct automatic assembling, the more the liquid
material is applied, the lower the friction coefficient, but
blocking of the parts themselves will occur due to sticking of the
applied liquid material, thereby bringing about an inconvenience to
the automatic feeding of the parts. To reduce the sticking
occurrence, on the other hand, the less the liquid material to be
applied, the more often the liquid material is liable to deposit
onto the surroundings, thereby causing the blocking. The applied
liquid material is liable to come off due to the liquid nature, and
thus its retainability is not sufficient. Furthermore, it is
difficult to control the application amount of the liquid material,
and thus it is difficult to obtain the rubber parts in a stable
state only by the liquid material. Blocking as well as sticking can
be prevented by spraying inorganic powders of graphite, silica,
talc, etc., but surrounding pollution due to disengagement of the
deposited powders is inevitable.
[0005] To overcome such problems, Patent Document 1 proposed a
surface-treating agent, which comprises (1) a reaction product of
polysiloxane having a terminal hydroxyl group, with silyl
isocyanate, (2) a reaction product of an oligomer having a
functional group reactive with an isocyanate group, with silyl
isocyanate, (3) a silyl isocyanate oligomer represented by the
following general formula:
##STR00002##
(R: an alkyl group, an aryl group, or an isocyanate group, and n:
an integer of 1 or more), and (4) an organic solvent-soluble
rubber. The assembling work and stickiness can be improved by such
a surface-treating agent, but the major component of the
surface-treating agent is an organic solvent such as toluene, ethyl
acetate, methyl ethyl ketone, etc., which can also lead to such
problems as a high environmental load and a difficult handling.
[0006] Patent Document 1: JP-A-2000-63744
[0007] Patent Document 2 proposes an aqueous mold-releasing agent
composition for use upon application to the surface of a mold,
which comprises (A) a silicone emulsion, (B) a urethane resin-based
aqueous emulsion, and (C) a silane compound having at least one of
epoxy group and methacryloxypropyl group at the molecular chain
terminal, and/or a partial hydrolyzate thereof. Such a composition
has a low environmental load due to the aqueous system, but has a
problem of surrounding pollution due to bleeding of oily matters
onto the surface after application and drying, when used as a
surface-treating agent for the sliding members, which is the object
of the present invention, because the aqueous emulsion containing a
polyhydrazide and a carbonyl group-containing polyurethane vinyl
hybrid polymer is used as Component (B). Furthermore, tight
adhesion to the rubber materials is not satisfactory, resulting in
short durability and easy peeling. Thus, the proposed composition
is not preferable.
[0008] Patent Document 2: JP-A-2005-125656
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0009] The object of the present invention is to provide an aqueous
surface-treating agent capable of preventing sticking between
rubber seal materials such as O rings, etc. themselves or sticking
to metals, resins, etc., and reducing friction of rubber or resin
seal members at the time of sliding motion.
Means for Solving the Problem
[0010] The object of the present invention can be attained by an
aqueous surface-treating agent, which comprises a silicone oil
aqueous emulsion, a polyurethane resin aqueous emulsion, and a
silane compound represented by the following general formula:
##STR00003##
(where R.sup.1 and R.sup.2 each are an alkyl group having 1-4
carbon atoms, n and m are 1.ltoreq.11.ltoreq.3 and m=3-n,
respectively), and/or a partial hydrolyzate thereof, wherein 100
parts by weight or more, preferably 100-2,000 parts by weight, of
the polyurethane resin in terms of the weight of solid matters is
used on the basis of 100 parts by weight in terms of the weight of
nonvolatile matters of the silicone oil.
Effect of the Invention
[0011] The present surface-treating agent has such features as a
low environmental load owing to the nature of an aqueous system and
a good applicability without any special equipment. Furthermore,
the tight adhesion to substrates can be attained without any
bleeding of oily matters by making the total polyurethane resin
content higher than the silicone oil content, whereby a
distinguished durability can be obtained. As a result, sticking
between rubber materials such as 0 rings themselves or sticking to
metals, resins, etc. can be effectively prevented, and furthermore
friction of rubber or resin seal members can be reduced at the time
of sliding motion.
[0012] When a mixture of (a) an aqueous emulsion containing a
hydrazide and a carbonyl group-containing polyurethane resin and
(b) an aqueous emulsion of a silanol-modified polyurethane resin is
used as the polyurethane resin, the solvent resistance can be also
improved in addition to the afore-mentioned features.
BEST MODES FOR CARRYING OUT THE INVENTION
[0013] The silicone oil for use in the present invention includes
an organopolysiloxane having at least one organic group bonded to
the silicon atom and having a kinematic viscosity at 25.degree. C.
of 50-1,000,000 mm.sup.2/sec., preferably 500-200,000
mm.sup.2/sec., where its molecular structure can be any of linear,
branched or reticular structures, preferably linear or branched
one, more preferably linear one. The organic group bonded to the
silicon atom of organopolysiloxane is typically an alkyl group such
as methyl, ethyl, propyl, butyl, or hexyl; an alkenyl group such as
vinyl, or propenyl; an aryl group such as phenyl; an aralkyl group
such as phenethyl; and those hydrocarbon groups, some of whose
hydrogen atoms are substituted by a halogen atom, a nitrile group,
etc. The terminal organic group of organopolysiloxane is typically
methyl, amino, epoxy, carbinol, hydroxyl, methoxy, methacryloxy,
carboxyl, silanol, alkoxy, etc., and preferably carbinol, hydroxyl
or methoxy. The silicone oil can give a lubricability, a low
friction, and a non-stickiness to the surface-treatment film.
[0014] The aqueous emulsion containing such a silicone oil for use
in the present invention includes not only a hydrophilic type
silicone oil aqueous emulsion, but also an emulsifier-forced
emulsion type silicone oil aqueous emulsion, where their dispersion
method is not particularly limited. Such silicone oil aqueous
emulsions have a silicone oil content (nonvolatile matters) of 3-60
wt. %.
[0015] The silicone oil aqueous emulsion is admixed with a
predetermined amount of a polyurethane resin aqueous emulsion.
Polyurethane resin (solid matters) is added to the silicone oil
aqueous emulsion in a proportion of 100 parts by weight or more,
preferably 100-2,000 parts by weight, on the basis of 100 parts by
weight of silicone oil (nonvolatile matters) of the silicone oil
aqueous emulsion. When the polyurethane resin is used in a
proportion of less than 100 parts by weight, the coatability will
be lowered, and bleeding of silicone oil will occur to lower the
durability. Thus, this is not preferable.
[0016] The polyurethane resin aqueous emulsion includes a
self-emulsification type having hydrophilic groups as introduced
into the polyurethane structure, a forced emulsification type
emulsified by an emulsifier, etc., where any type of polyurethane
molecular structure, such as ether polyol type, ester polyol type,
polycarbonate type, etc. can be used without any particular
limitation. It is preferable to use an aqueous emulsion containing
a hydrazide and a carbonyl group-containing polyurethane resin as a
self cross-linkable type polyurethane, and more preferable to use a
mixture thereof further with a silanol-modified polyurethane resin
aqueous emulsion or with a self cross-linkable group-free
polyurethane resin aqueous emulsion, particularly preferably a
mixture thereof further with a silanol-modified polyurethane resin
aqueous emulsion. In the case of the mixture thereof further with
the silanol-modified polyurethane resin aqueous emulsion, it is
preferable to prepare the mixture upon mixing in a ratio by weight
of solid matter sum total of the aqueous emulsion containing a
hydrazide and carbonyl group-containing polyurethane resin
silanol-modified polyurethane resin=5-90:95-10. In the case of the
mixture thereof further with the self cross-linkable group-free
polyurethane resin aqueous emulsion, the same solid matter ratio by
weight as mentioned above can be used.
[0017] The self cross-linkable type polyurethane has more
distinguished solvent resistance, tight adhesion, and stability
than those of the self cross-linkable group-free polyurethane
resin, and thus even in the case of using only the aqueous emulsion
containing a hydrazide and a carbonyl group-containing polyurethane
resin, the afore-mentioned characteristics can be fully obtained by
making total content of polyurethane resin higher than the silicone
oil content. The silanol-modified, self cross-linkable type
polyurethane can attain much higher levels of solvent resistance
and tight adhesion. Thus, a polyurethane resin aqueous emulsions
surface-treating agent comprising a mixture of these components can
reduce the friction of rubber or resin seal members at the time of
sliding motion, and also can improve the solvent resistance. The
silanol groups as contained therein have a good compatibility with
silicone oil and silane compound as constituents of the aqueous
surface-treating agent. This is another advantage of using the
silanol-modified polyurethane resin aqueous emulsion.
[0018] The aqueous emulsion containing a hydrazide and a carbonyl
group-containing polyurethane resin includes an aqueous emulsion
containing a hydrazide and a carbonyl group-containing polyurethane
vinyl hybrid polymer, as disclosed in Patent Documents 3 and 4,
where the azomethine bonds formed by reaction of the hydrazide with
the carbonyl group of polyurethane-vinyl-hybrid polymer can lead to
cross-linking. In this case, these two compounds can be used
generally in a proportion of the number of hydrazine groups to the
number of carbonyl groups of 1:40-2:1.
##STR00004##
[0019] The hydrazide includes hydrazine, lower molecular weight
aliphatic compound, aromatic compound or mixture thereof having a
hydrazide group and/or a hydrazone group, and further includes a
polyhydrazide or a polyvalent hydrazide compound having at least
two of these groups. The polyurethane-vinyl-hybrid polymer can be
prepared by free radical-initiated polymerization of an ionically
and/or nonionically stabilized polyurethane macromonomer having a
terminal vinyl group and/or side chain vinyl group, and in some
cases a terminal hydroxyl group, a urethane group, a thiourethane
group or a urea group, with other functional vinyl monomer having a
carbonyl group, and a non-functional vinyl monomer. For such
aqueous emulsion, commercially available products, such as Daotan
VTW6462/36WA, a product of Japan Thytec Industries, Daotan series,
products of Solucia Japan, etc. can be practically used, as
described in afore-mentioned Patent Document 2.
[0020] Patent Document 3: JP-A-7-233347
[0021] Patent Document 4: JP-A-2006-299274
[0022] The silanol-modified polyurethane resin aqueous emulsion is
an aqueous dispersion containing silanol groups in the polyurethane
structure, where the silanol groups turn to siloxane bonds by
condensation cross-linking reaction:
##STR00005##
The siloxane bonds are stable, as compared with bonds formed by
other urethanization cross-linking reaction, and thus the resulting
surface treatment film has such an effect as a good solvent
resistance. The polyurethane resin aqueous emulsion can give a
sliding durability to the surface treatment film, and further can
take the silicone oil therein to give a lubricability, a low
frictional resistance, and a non stickiness, without any bleeding
the oil matters to the surface treatment film. The silanol-modified
polyurethane resin aqueous emulsion for use herein has a resin
concentration of 10-70 wt. % in terms of solid matters.
[0023] The silane compound for use herein includes silane compounds
represented by the following general formula:
H.sub.2N(CH.sub.2).sub.3Si(OR.sup.1)nR.sup.2m, (D)
or
H.sub.2NC.sub.2H.sub.4NH(CH.sub.2).sub.3Si(OR.sup.1)nR.sup.2m
(E)
(R1, R2 an alkyl group having 1-4 carbon atoms, n, m
1.ltoreq.n.ltoreq.3, m=3-n). These silane compounds are components
capable of holding the silicone oil within the surface treatment
film by reaction of the reactive organic groups of the silicone
emulsion with the alkoxy groups of the afore-mentioned specific
silane compounds, and capable of giving a lubricability, a low
friction resistance, and a non-stickiness of the surface, without
any bleeding the oily matters, and also reacting with the
polyurethane aqueous emulsion to improve the affinity between
cross-linked polyurethane resin and the silicone oil to retain the
silicone oil within the surface treatment film. Furthermore, these
silane compounds can act to improve the coatability on a substrate
to be surface treated.
[0024] Such silane compounds include, for example,
.gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropyltriethoxysilane,
.gamma.-glycidoxypropyltripropoxysilane,
.gamma.-glicidoxypropylmethyldimethoxysilane,
.gamma.-glycidoxypropylmethyldiethoxysilane,
.gamma.-glicidoxypropylmethyl-dipropoxysilane, (i.e. silane
compounds A); .gamma.-methacryloxypropyltrimethoxysilane,
.gamma.-methacryloxypropyltriethoxysilane,
.gamma.-methacryloxy-propyltripropoxysilane,
.gamma.-methacryloxypropylmethyldimethoxysilane,
.gamma.-methacryloxypropylmethyldiethoxysilane,
.gamma.-methacryloxypropylmethyl-dipropoxysilane (i.e. silane
compound B); 3-acryloxypropylmethyl-dimethoxysilane,
3-acryloxypropylmethyldiethoxysilane,
3-acryloxypropyl-triethoxysilane (i.e. silane compounds C);
3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane (i.e.
silane compounds D); and
N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane,
N-2-(aminoethyl)-3-aminopropyltrimethoxysilane,
N-2-(aminoethyl)-3-aminopropyltriethoxysilane,
3-(2-aminoethyl)-aminopropylmethyldimethoxysilane (i.e. silane
compounds E), among which .gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropylmethyldimethoxysilane,
.gamma.-methacryloxypropyltrimethoxysilane,
.gamma.-methacryloxypropylmethyldimethoxysilane, etc. can be
preferably used.
[0025] Partial hydrolyzates of these silane compounds can be also
used in the present invention. The hydrolyzates can be obtained by
condensation reaction of one of the silane compounds or a mixture
of two or more thereof, under hydrolysis conditions depending on
the species of the selected silane compounds.
[0026] It is preferable to add 10-60 parts by weight of the silane
compound to 100 parts by weight of oily matters (nonvolatile
matters) of silicone oil emulsion. When the silane compound is used
in a proportion of more than 60 parts by weight, the friction
coefficient will be increased, and the durability will be lowered,
whereas in a proportion of less than 10 parts by weight, excess
bleeding of oil will occur.
[0027] To prevent thread-forming spinnability or partial liquid
gathering, thereby stopping occurrence of a potted coating or short
coating amount, the surface-treating agent comprising
above-mentioned, essential components can contain an amphoteric
surfactant such as alkylamine oxide-based compounds, alkyl betaine,
etc. The alkylamine oxide-based compounds include
dimethylalkylamine oxide, etc., and the alkyl betaine includes
alkyldimethylaminoacetic acid betaine, etc., where the alkyl group
includes, for example, lauryl group, myristyl group, natural
oil-modified groups derived from coconut oil, etc. The alkylamine
oxide-based compound or the alkyl betaine can be used in a
proportion of 10 wt. % or less on the basis of total
composition.
[0028] The surface-treating agent can further contain a defoaming
agent, a pigment, inorganic powders, a thickening agent, a
surfactant, etc., if required. The composition is used upon
dilution with water to a concentration of the effective components
to 0.1-40 wt. % from the viewpoint of coating efficiency and
coatability. These compounding ingredients are used upon mixing and
emulsification treatment with sufficient stirring. The mixing can
be carried out by a well-known mixer-stirrer, a combi-mix, etc.
provided with stirring blades of paddle type, anchor type, etc.,
and the emulsification treatment can be carried out by an
emulsifying dispersing device such as a colloid mill, a homo-mixer,
a homogenizer, a sand grinder, etc.
[0029] The surface-treating agent so prepared can be subjected to
surface treatment by applying it to the surface of a member to be
coated by immersion, brush coating, roll coating, spray coating,
knife coating, dip coating, etc., followed by heat drying at
120.degree.-150.degree. C. for 30-60 minutes to form a cured
film.
[0030] The present surface-treating agent can be effectively used
for rubber materials such as fluororubber, NBR, hydrogenated NBR,
SBR, isoprene rubber, butadiene rubber, chloroprene rubber, acrylic
rubber, EPDM, urethane rubber, silicone rubber, etc., or for resin
materials such as thermoplastic resins, thermosetting resins, etc.,
for example, ABS, AS, etc.
EXAMPLES
[0031] The present invention will be described in detail below,
referring to Examples.
TABLE-US-00001 Parts by weight Both terminal hydroxyl
groups-containing emulsion 4.07(1.34) polymerization
polydimethylsiloxane aqueous emulsion (viscosity at 25.degree. C.:
100,000 mPa sec; nonvolatile matters: 33%) Hydrazide and carbonyl
group-containing polyurethane 2.71(0.98) resin aqueous emalsion
(solid matters 36 wt. %; Daotan VTW 6462/36WA) Silanol-modified
polyurethane resin aqueous emulsion 6.67(2.00) (solid matters: 30
wt. %; Tackelack WS-5000, a product of Mitsui Chemical Polyurethane
Co.) .gamma.-glycidoxypropyltrimethoxysilane 0.68
Dimethyllaurylamine oxide (amphoteric surfactant) 0.45 Water
85.42
The foregoing components (figures in the parentheses show weights
of solid matters) were mixed together, and further subjected to
emulsification treatment by a homogenizer and an ultrasonic
treating unit to obtain a surface-treating agent. The resulting
surface-treating agent had 2.98 parts by weight of total
polyurethane resins, which corresponded to 222.3 parts by weight on
the basis of 100 parts by weight of silicone oil (in terms of
nonvolatile matters, as will be likewise used hereinafter).
[0032] Then, the surface-treating agent was applied to a
fluororubber sheet and a fluororubber O ring (hardness: JIS A70
dimensions: 7.8 mm in inner diameter, 1.9 mm in thickness
(diameter), and nominal number: JIS B 2401-4 grade D P8 by spray
costing method), and then cured at 150.degree. C. for 30 minutes to
obtain the coated fluororubber sheet and O ring each having a
coating film as formed thereon to a film thickness of about 2
.mu.m.
[0033] The surface treated fluororubber sheet having a thickness of
2 mm or O ring was subjected to determination and tests according
to the following test items:
[0034] Friction coefficient: According to ASTM D-1894 determine
kinematic friction coefficient of surface-treated, vulcanized
rubber sheet surface by using a surfaceness tester, Heydon
tribogear, made by Shinto Scientific Co.
[0035] (Test Conditions)
[0036] Mating member: SUS304 steel ball, 10 mm in diameter
[0037] Moving speed: 50 mm/min.
[0038] Load: 0.49N
[0039] Amplitude: 50 mm
[0040] Durability test: To conduct a test under the following
conditions, using a Heydon tribogear, and then evaluate the tested
film states according to the following ranking:
[0041] No peeling: O
[0042] Partial exposure of the substrate: X
[0043] (Test Conditions)
[0044] Mating member: SUS304 steel ball, 10 mm in diameter
[0045] Moving speed: 400 mm/min.
[0046] Load: 0.98N
[0047] Amplitude: 30 mm by 500 runs
[0048] Non-stickiness test: To conduct a test by sandwiching the
surface-treated fluororubber O ring between SUS430 members,
followed by heating in a thermostat tank at 150.degree. C. in a 50%
compressed state for 30 minutes, leaving to stand at room
temperature for one hour, releasing the O ring from the SUS
members, and then to evaluate the releasing state according to the
following ranking: [0049] Immediately releasable from the mold
without any trouble: O [0050] Sticky right after the leasing
operation, but releasable from the mold one minute thereafter:
.DELTA. [0051] Sticky or peeling by transfer to the SUS members:
X
[0052] Solvent resistance test: To immerse the surface-treated
fluororubber O ring into toluene for 24 hours, then conduct as
ultrasonic washer treatment for 10 minutes, while keeping the O
ring as immersed in toluene, then taking it out of the toluene, and
evaluate the film state according to the following ranking:
[0053] Neither dissolution nor peeling of the film: O
[0054] Neither dissolution nor peeling, but whitening of the film:
.DELTA.
[0055] Observation of either dissolution or peeling of the film:
X
Bleeding evaluation: To apply the surface-treating agent to a
rubber sheet, followed by drying, and evaluate the surface state of
the surface-treated rubber sheet according to the following
ranking:
[0056] No bleeding of oily matters to the surface: O
[0057] Bleeding of oil matters to the surface: X
[0058] Pot life test: To leave a surface-treating agent solution
having a solid matter concentration of 10 wt. % to stand in the
circumstance at the liquid temperature of 25.degree. C. and the
humidity of 70% for 72 hours and evaluate formation of precipitates
in the solution by visual observation according to the following
ranking:
[0059] No observation of precipitates: O
[0060] Observation of precipitates: X
[0061] Coatability test: To visually observe the coating film state
of surface-treated fluororubber sheet to evaluate according to the
following ranking: Uniform coating without any unevenness: O
[0062] Uneven coating without uniform coating: X
[0063] Evaluation of O ring transporting characteristics by parts
feeder: To transport 500 surface-treated fluororubber O rings by a
parts feeder, and count the number of passed O rings per hour
(transport rate) and the number of O rings remaining on the parts
feeder, where the more the passed O rings number, the higher the
transport rate, and the blocked O rings remain on the parts
feeder
Example 2
[0064] In Example 1, the same amount of
.gamma.-methacryloxypropyltrimethoxysilane was used in place of
.gamma.-glycidoxypropyltrimethoxysilane. The resulting
surface-treating agent had 2.98 parts by weight of total
polyurethane resins, which corresponded to 222.3 parts by weight on
the basis of 100 parts by weight of silicone oil.
Example 3
[0065] In Example 1, the same amount of a self-cross-linking
group-free polyurethane resin aqueous emulsion (solid matters 30
wt. %; Tackelack W-6061, a product of Mitsui Chemical Polyurethane
Co.) was used in place of the silanol-modified polyurethane resin
aqueous emulsion. The resulting surface-treating agent had 2.98
parts by weight of total polyurethane resins, which corresponded to
222.3 parts by weight on the basis of 100 parts by weight of
silicone oil.
Example 4
[0066] In Example 1, the silanol-modified polyurethane resin
aqueous emulsion was excluded from use, and the amount of the
hydrazide and carbonyl group-containing urethane resin aqueous
emulsion was changed to 8.28 (2.98) parts by weight. The resulting
surface-treating agent had 2.98 parts by weight of total
polyurethane resins, which corresponded to 222.3 parts by weight on
the basis of 100 parts by weight of silicone oil.
Comparative Example 1
[0067] In Example 1, the following components were used for a
surface-treating agent
TABLE-US-00002 Parts by weight Both terminal hydroxyl
groups-containing, emulsion 2.30(0.76) polymerization
polydimethylsiloxane aqueous emulsion (nonvolatile matters 33%)
Hydrazide and carbonyl group-containing polyurethane 1.55(0.56)
resin aqueous emulsion (solid matters: 36 wt. %)
.gamma.-glycidoxypropyltrimethoxysilane 0.40 Dimethyllaurylamine
oxide 0.75 Water 95.00
The resulting surface-treating agent had 0.56 parts by weight of
total polyurethane resins, which corresponded to 73.5 parts by
weight on the basis of 100 parts by weight of silicone oil.
Comparative Example 2
[0068] In Comparative Example 1, the same amount of
.gamma.-methacryloxypropyltrimethoxysilane was used in place of the
.gamma.-glycidoxypropyltrimethoxysilane. The resulting
surface-treating agent had 0.56 parts by weight of total
polyurethane resins, which corresponded to 73.5 parts by weight on
the basis of 100 parts by weight of silicone oil.
Comparative Example 3
[0069] In Comparative Example 1, neither hydrazide and carbonyl
group-containing polyurethane resin aqueous emulsion, nor
.gamma.-glycidoxypropyltrimethoxysilane, and dimethyllaurylamine
oxide was used at all.
Comparative Example 4
[0070] In Example 1, no surface treatment was carried out at
all.
[0071] The results obtained in the foregoing Examples and
Comparative Examples are shown in the following Table.
TABLE-US-00003 TABLE Example No. Comp. Ex. No. 1 2 3 4 1 2 3 4 Test
items Friction coefficient 0.16 0.16 0.17 0.17 0.18 0.18 0.05 2.50
Durability test .largecircle. .largecircle. .largecircle.
.largecircle. X X X -- Non-stickiness tests .largecircle.
.largecircle. .DELTA. .DELTA. .largecircle. .largecircle.
.largecircle. X Solvent resistance test .largecircle. .largecircle.
X .DELTA. .DELTA. .DELTA. X -- Bleeding evaluation .largecircle.
.largecircle. .largecircle. .largecircle. X X X -- Pot life test
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. -- Coatability test
.largecircle. .largecircle. .largecircle. .largecircle. X X X --
Transport characteristics test Transport rate 100 100 90 80 50 40
60 10 (number of O rings/min) Remaining O rings 0 0 10 10 100 110
200 300 (number) Overall evaluation .largecircle. .largecircle.
.DELTA. .DELTA. X X X X
[0072] It can be seen from the foregoing results that in the cases
of low friction coefficient without any stickiness there are such
tendencies that blocking and number of remaining 0 rings will be
smaller, and the transport rate will be higher, whereas in the case
of application of only silicone oil or higher silicone oil content,
stickiness will be increased though the friction coefficient is
lowered, resulting in blocking of O rings themselves, and slower
transport rate.
INDUSTRIAL UTILITY
[0073] The present aqueous surface-treating agent can be
effectively used for the surface treatment of seal materials such
as 0 rings, oil seals, V rings, D rings, X rings, packings, etc.,
automobile sliding rubber such as weather strips, wiper blades,
etc., business machine rubber materials such as toner blades,
rubber rolls, etc., resin gears for use in automobiles, business
machines, etc., and sliding members such as paper-feeding resin
clicks for printers, etc.
* * * * *