Note: Descriptions are shown in the official language in which they were submitted.
20710~3
SURFACE COATING MEMBER
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention concerns a surface coating
member and, more in particular, it relates to a surface
coating members prepared by applying a lubricating coating
to the surface of a rubber or plastic member such as wiper
blade, seal packing, O-ring, weather strip, glass run,
timing belt, rubber bellows, gear and door catcher. More
in particular, the present invention relates to a surface
coating member suitable as a surface-coated sliding member
such as a wiper blade, glass run, weather strip and O-ring
whose surface is in sliding contact with other members.
Description of the Prior Art
For a wiper blade rubber, a molding product of natural
rubber or synthetic rubber has been employed so far.
However, the wiper rubber of this kind has the following
drawbacks and hence is not always satisfactory.
That is, slnce an adhering phenomenon occurs between
the wiper blade rubber and a glass surface in the damp-
drylng state or under cold climate condition, to bring
about a so-called "locking phenomenon" in which the wipe~r
20710~3
operation is blocked, or a so-called "trembling phenomenon",
that is, self-exciting vibration due to the negative cha-
racteristics of the velocity dependency of the frictional
coefficient. This leads to problems such as (1) unsatis-
factory wiping, (2) abnormal abrasion at the surface of
the blade rubber, (3) shortening for the life in each of
the connection portions of the wiper system,(4) increase
in the consumption power for the operation motor and (5)
eyesore and grating due to the trembling phenomenon.
For overcoming such problems, Japanese Patent Laid-
Open Sho 55-15873 proposes to coat the rubber surface
of a wiper blade with a silicone composition containing
molybdenum disulfide.
However, in the wiper blade rubber having such a
coating as described in the above-mentioned patent publi-
cation, it has been found that the durability of the coating
layer becomes poor. The problem also occurs in the weather
strip or the glass run.
Further, the following drawbacks are also caused
between the metal surface and the rubber material and the
coating material not always has a satisfactory property.
That is, in an oil seal or gasoline cap seal, sticking
occurs between the rubber and the metal surface to increase
torque upon opening and closure. In an O-ring, packing or
timing belt, there happens abnormal abrasion, stlck slip
20710~3
r generation of ringing owing to high slidlng resistance
between the rubber and the metal surface. Also in rubber
bellows, puncture occurs due to the abnormal abrasion.
Further, in a gear or door catcher made o~ polyacetal,
nylon resin, etc. abnormal abrasion, ringing or creaking
occurs.
For overcoming the ~oregoing problems, although a
countermeasure such as coating of grease has been applied,
this lacks in durability.
OBJECT AND SUMMARY OF THE INVENTION
The obfect of the present invention is to overcome
the foregoing problems and provide a surface coating member
having excellent slid$ng property and also high durability
o~ the coating layer.
An improved surface coating member was disclosed by the
inventors in PCT/JP91/00533 wherein the above-mentioned
problems are solved. The present invention has an object to
improve surface coating member of PCT/JP91/00533 and enhance
strength and hardwearing properties of a surface layer.
The surface coating member according to the present
invention comprises a surface coating member in which a coating
layer containing a solid lubricant, a resin matrix and rein-
forcement i8 formed at the surface, in which the resin matrix
comprises a ~luoro-ole~in vinyl ether polymer resln and/or
a ~luoro-ole~ln vinyl ether vinyl ester copolymer resin.
There is no particular restriction to rubber or plastic
constituting the main body portion o~ the coating member
according to the present invention but various kinds of
rubber and plastic can be employed. The rubber may be
20710~3
. .
either of natural or synthetic rubber. As an example of
the synthetic rubber, there can be mentioned, for instance,
styrene butadiene rubber, butadiene rubber, isoprene rubber,
ethylene propylene rubber (EPM, EPDM), acrylonitrile buta-
diene rubber, chloroprene rubber, isobutylene isoprene
rubber, alfin rubber, polyether rubber, polysulfide rubber,
silicone rubber, acrylic rubber, fluoro rubber, halogenated
polyethylene rubber, urethane rubber, ethylene vinyl
acetate rubber, high styrene rubber and acrylonitrile
isoprene rubber. Among them, EPDM is particularly,
preferred.
As the plastic material, either of a thermosetting
resin or a thermoplastic resin may be used.
As an example oi the plastic, there can be mentioned,
ior instance, ABS resin, ABS blend, acetal resin (homo-
polymer), acryl resin, ACS resin, alkyd resin, amino resin,
ASA resin, cellulose type resin, chlorlnated polyether,
diallyl phthalate resin, epoxy resin, ethylene - vinyl
acetate copolymer, fluoro resin, ionomer, methyl pentene
polymer, phenol resin, polyamide (nylon), polyallyl ether,
polyallyl sulfone, polybutene-l, polycarbonate, unsaturated
polyester resin, polyethylene, polyethylene terephthalate
(tetron), polyimide, polyamideimide, polyphenylene oxide,
polyphenylene suliide, polypropylene, polystyrene, poly-
sulione, polyether sulfone, polyurethane, vinyl chloride
-- 4
2071053
~sin, polyallylate and so on.
The coating layer coating the rubber or plastic
comprises a solid lubricant, a resin matrix and reinforcement.
As the resin matrix, a fluoro-olefin vinyl ether
polymer resin and/or a fluoro-olefin vinyl ether vinyl
ester copolymer resin may be used.
As the solid lubricant, there can be used, for example,
sulfide such as molybdenum disulfide and tungsten disulfide,
~luoride such as polytetrafluoro ethylene and fluorinated
graphite, graphite and silicone powder. The solid lubricant
described above may be used alone or as a combination o~ two
or more o~ them. In the present invention, combined use of
the sulfide, fluoro compound and graphite is preferred in
view of the excellent lubrication resistance, fitness and
feeling. In this case, the blending ratio for the sulfide,
fluoro compound and graphite is preferably from 10 to 1500
parts by weight o~ the sulfide and 100 to 3000 parts by
weight o~ the fluoro compound based on 100 parts by weight
of the graphite, more preferably, from 10 to 200 parts by
weight of the sulfide and 100 to 2000 parts by weight of the
fluoro compound.
It is desirable that the solid lubricant has an average
grain size of less than 10 pm, preferably, less than 5 ~m.
partlcularly, pre~erablY~ less than 3 pm.
As the reinforcement, there can be used, for example,
carbon black and/or fibrous filler. The carbon black rein-
forces the coating layer and acts as black pigment. The
fibrous filler reduces wear of the solid lubricant such as
polytetrafluoroethylene, silicone powder or the like, so
20710~3
that hardwearing properties and strength of the coating
layer are enhanced. As the fibrous filler, there can be used
carbon fiber, glass fiber, silicon carbide fiber, alumina
(aluminium oxide) fiber, potassium titanate fiber and so on.
It is desirable that the fiber has a diameter of 0.3 ~um to
5.0/um and a length of 5 ~m to 100/um.
The blending ratio of the solid lubricant, resin matrix
and reinforcement is preferably from 49.9 to 80 parts by
weight of the solid lubricant, 50 to 5 parts by weight of
the resin matrix and 0.1 to 15 parts by weight of reinfor-
cement, more preferably, from 67 to 85 parts by weight of
the solid lubricant, 30 to 10 parts by weight of the resin
matrix and 3 to 5 parts by weight of reinforcement.
For ~orming the coating on the surface o* the rubber
or the plastic in the present invention, the solid lubricant,
the resin matrix, reinforcement and a curing agent may be
coated being dispersed or dissolved in an organic solvent.
As the curing agent, there can be used, for
example, polyisocyanate and melamine resin.
As the organic solvent. methyl ethyl ketone, toluene,
xylene, isopropyl alcohol. isobutanol. n-butanol, butyl
acetate, MIBK and cellosolve acetate are pre~erred, for
example.
As the coating method, various method such as brushing,
spraying or dipping may be employed. Prior to the coating.
the surface of the rubber or plastic may be cleaned or a
sur~ace treatment may be applied for lmproving the fitness
with the resin matrix. For the surface treàtment, a primer
treatment can be mentioned.
20710~3
It should be noted that the present invention differs
from that of PCT/JP91/00533 in the presence of the reinfor-
cement. Namely, the surface coating member of PCT/JP91/00533
is consisted from the solid lubricant and the resin matrix
where the lubricant and the matrix are identical entirely to
those of the present invention. (Incidentally, in PCT/JP9l/
00533, it is desirable that the surface coating member
comprises 50 to 95 parts by weight of the solid lubricant
and 50 to 5 parts by weight of the resin matrix, more par-
ticularly, 70 to 90 parts by weight of the solid lubricant
and 30 to lO parts by weight of the resin matrix.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. l is a schematic side elevational view for
illustrating the method of experiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present will now be explained with reference to
examples and comparative examples.
Compositions shown in the following (Comparative
Example l) - (Comparative Example 13)~ as well as (Example
l) - (Example 9) were sprayed on the surface of rubber
pieces, and the compositions were cured under the curing
conditlons (heatlng conditions) shown for each of them,
to form a coating layer at a thickness of lO ~m to the
surface of each of the rubber pieces. Each rubber piece
was cut into a slze of lO mm x 6 mm x 2 mm to prepare a
test piece. The coating sur~ace was ~ormed on the lO mm x
6 mm surface of the test piece.
The test plece was mounted to FALEX No. 1 Tester
(Faville-Levally Corporation) and the durability of the
coatlng layer was examined.
207105~
Fig. 1 is a schematic side elevational view illustra-
ting the state of the test, in which a test piece was held
to a test piece holder 2 and urged to the outer circumfe-
rential surface of a ring 3 of 35 mm diameter under a load
of 9.06 kg (20 LBS). The outer circumferential surface of
the ring 3 was made of SAE 4620 steel and the surface
roughness was 6 - 12 rms. The ring 3 was reciprocally
rotated around the axial center as shown by arrows within
a rotational range oi 90 at a rate of 100 cycle/min.
The number of cycles at which the frictional coeffi-
cient reached 0.2 was measured as a life cycle. In a case
where the coating layer was abraded to expose the rubber
layer before the frictional coeificient reached 0.2, the
number of cycles up to that time was defined as the life
cycle.
The life cycle for each of the comparative examples and the
the examples is as shown in Table-l and Table-2. The static
irictional coefflcient and the dynamic frictional coef-
iicient at the surface of the coating layer ior each of
the test pleces beiore the slldlng movement with the ring
3 were measured and the results are also shown together in
Table-l and Table-2.
From Table-l and Table-2, it-can be seen that the test
pieces of Examples 1 - 9 according to the present invention
have low friction coefficient and the durability of the
coating layer was remarkably high.
It is seen clearly that the reinforcement enhances
durability of the coating layer when compound the com-
parative examples 5 to 13 and the examples 1 to 9 wherein
the reinforcement is comprised in each of the comparative
examples 5 to 13 respectively.
2Q71~
The average grain size of the solid lubricant used
hereinafter is less than 5 ~m in each o~ the cases.
In the following descriptions, "parts" means "parts
by weight".
(Comparative Example 1)
(Polyurethane resin) Nipporan 5185 100 parts
(manufactured by Nippon Polyurethane Industry co.)
(Isocyanate curing agent) Coronate HL 10.0 parts
Curing cond~tions: 80C - 30 min.
(Comparative Example 2)
(Polyurethane resin) Nipporan 5185 26.0 parts
(manuiactured by Nippon Polyurethane Industry co.)
(Molybdenum disul~ide) Technical grade30.0 parts
(manuiactured by Climax Molybdenum Co.)
(Polytetrafluoroethylene) Lubron L-542.0 parts
(manuiactured by Daikin Industry Co.)
(Graphite) ACP 1000 2.0 parts
(manu~actured by Nippon Graphite Industry Co.)
(Isocyanate curing agent) Coronste HL2.6 parts
Curing conditions: 80C - 30 min.
Comparative Example 3) (corresponding to Example 3 in
Japanese Patent Laid-Open Sho
55-15873)
KM-765 (Emulsion with 20X silicone content) -45 parts
(manuiactured by Juetsu Chemical Co.)
C-PM-4F (catalyst, manu~actured by Juetsu
Chemlcal Co.) 4.5 parts
g
20710~
Molybdenum disulfide (4.5 ~m average grain size) 4.0 parts
Water 52.0 parts
Curing condition: After leaving at a room temperature for
10 min, a cured layer was obtained at 150C - 10 min
(Comparative Example 4)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 100 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Isocyanate curing agent) Barnock DN980 24 parts
(msnufactured by Dainippon Ink Chemical Industry Co.)
Curing condition: 80C - 10 min.
(Comparative Example 5)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 26 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technical grade 30 parts
(manufactured by Climax Molybdenum Co.)
(Polytetrailuoro ethylene) Lubron L-5 42 parts
(manufactured by Daikln Industry Co.)
(Graphlte) ACP 1000 2 parts
(manu~actured by Nippon Graphite Industry Co.)
(Isocranate curing agent) Barnock DN980 6.2 parts
(Dainippon Ink Chemical Industry Co.)
Curlng condltlon: 80C - 10 min.
- 10
20710~3
(Comparative Example 6)
(Fluoro-olefin vinyl ether vinyl ester copolymer~
Fluonate K702 28 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technlcal grade10 parts
(manufactured by Climax Molybdenum Co.)
(Polytetrafluoro ethylene) Lubron L-560 parts
(manufactured by Daikin Industry Co.)
(Graphite) ACP 1000 2 parts
(manufactured by Nippon Graphite Industry Co.)
(Isocyanate curing agent) Barnock DN980 6.7 parts
(Dainippon Ink Chemical Industry Co.)
Curing condition: 80C - 10 min.
(Comparative Example 7)
(Fluoro-olefin vinyl ether vlnyl ester copolymer)
Fluonate K702 28 parts
(manufactured by Dainlppon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technical grade47 parts
(manu~actured by Climax Molybdenum Co.)
(Polytetrai'luoro ethylene) Lubron L-523 parts
(manu~actured by Daikin Industry Co.)
(Graphite) ACP 1000 2 parts
(manu~actured by Nippon Graphite Industry Co.)
-- 11 --
20710~3
(Isocyanate curing agent) Barnock DN980 6.7 parts
(Dainippon Ink Chemical Industry Co.)
Curing condition: 80C - 10 min.
(Comparative Example 8)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 49 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technical grade39 parts
(Polytetrafluoro ethylene) Lubron L-510 parts
(Graphite) ACP 1000 2 parts
(Isocyanate curing agent) Barnock DN980 6.7 parts
Curing condition: 80C - 10 min.
(Comparative Example 9)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 49 parts
(Molybdenum dlsulflde) Technical grade47 parts
(Polytetrafluoro ethylene) Lubron L-52.5 parts
(Graphite) ACP 1000 1.5 parts
(Isocyanate curlng agent) Barnock DN980 12.0 parts
Curing condltlon: 80C - 10 mln.
(Comparative Example lO)
(Fluoro-olefln vlnyl ether vlnyl ester copolymer)
- 12
20710~3
Fluonate K702 49 parts
(Molybdenum disulfide) Technical grade 49 parts
(Graphite) ACP 1000 2 parts
(Isocyanate curing agent) Barnock DN980 12 parts :
Curing condition: 80C - 10 min.
(Comparative Example ll)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 39 parts
(Molybdenum disulfide) Technical grade 59 parts
(Graphite) ACP 1000 2 parts
(Isocyanate curing agent) Barnock DN980 9.4 parts
Curing condition: 80C - 10 min.
(Comparative Example 12)
(Fluoro-olefln vinyl ether vinyl ester copolymer)
Fluonate K702 28 parts
(Molybdenum disulfide) Technical grade 70 parts
(Graphite) ACP 1000 2 parts
(Isocyanate curing agent) Barnock DN980 6.7 parts
Curing condition: 80C - lO min.
(Comparative Example 13)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 20 parts
- 13
20710~3
tMolybdenum disulfide) Technical grade 78 parts
(Graphite) ACP 1000 2 parts
(Isocyanate curing agent) Barnock DN980 4.8 parts
Curing condition: 80C - 10 min.
(Example 1)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate K702 26 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technical grade 30 parts
(manufactured by Climax Molybdenum Co.~
(Polytetrafluoro ethylene) Lubron L-5 37 parts
(manu~actured by Daikin Industry Co.)
(Graphite) ACP 1000 2 parts
(manuiactured by Nippon Graphite Industry Co.)
(Carbon fiber) Kureka chop C5 parts
~manufactured by Kureha Chemical Industries, Ltd.)
(Isocyanate curing agent) Barnock DN980 6.2 parts
(Dain~ppon Ink Chemical IndustrY Co.)
Curlng condition: 80C - 10 min.
(Example 2)
(Fluoro-oleiin vinyl ether vinyl ester copolymer)
Fluonate K702 28 parts
(manu~actured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disuliide) Technical grade 5 parts
(manuiactured by Climax Molybdenum Co.)
- 14
2071053
fPolytetrafluoro ethylene) Lubron L-5 60 parts
(manufactured by Daikin Industry Co.)
(Graphite) ACP 1000 2 parts
(manufactured by Nippon Graphite Industry Co.)
(Carbon fiber) Kureka chop C 5 parts
(manufactured by Kureha Chemical Industries, Ltd.)
tIsocyanate curing agent) Barnock DN980 6.7 parts
(Dainippon Ink Chemical IndustrY Co.)
Curing condition: 80C - 10 min.
(Example 3)
(Fluoro-ole~in vlnyl ether vlnyl ester copolymer)
Fluonate K702 28 parts
(manufactured by Dainippon Ink Chemical Industry Co.)
(Molybdenum disulfide) Technical grade44 parts
(manu~actured by Clima~ Molybdenum Co.)
(Polytetra~luoro ethylene) Lubron L-S23 parts
~manu~actured by Daikin Industry Co.)
(Graphlte) ACP 1000 2 parts
(manu~actured by Nippon Graphite Industry Co.)
(Potassium titanate fiber) Tismo D 3 parts
~manufactured by Ohtsuka Chemical Industries, Ltd.)
(Isocyanate curlng agent) Barnock DN980 6.7 parts
(Dainippon Ink Chemical Industry Co.)
Curlng condltlon: 80C - 10 mln.
(Example 4)
tFluoro-ole~in vlnyl ether vinyl ester copolymer)
Fluonate ~702 49 parts
(manu~actured bY Dalnlppon Ink Chemlcal Industry Co.)
- 15
2'Q'71'0~
(Molybdenum disulfide) Technlcal grade 36 parts
(Polytetrafluoro ethylene) Lubron L-5 10 parts
(Graphite) ACP 1000 2 parts
(Potassium titanate fiber) Tismo D3 parts
(manufactured by Ohtsuka Chemical Industries, Ltd.)
(Isocyanate curing agent) Barnock DN980 6.7 parts
Curlng condition: 80C - 10 min.
(Example 5)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate X702 49 parts
(Molybdenum disulfide) Technical grade 44 parts
(Polytetrafluoro ethylene) Lubron L-5 2.5 parts
(Graphite) ACP 1000 1.5 parts
(Silicon carbide whisker) TWS-100 3 parts
(manufactured by Tokai Carbon Co., Ltd.)
(Isocyanate curing agent) Barnock DN980 12.0 parts
Curing condition: 80C - 10 min.
(Example 6)
(Fluoro-ole~in vinyl ether vinyl ester copolymer)
Fluonate K702 49 parts
tMolYbdenum disul~ide) Technical grade 46 parts
(Graphite) ACP 1000 2 parts
(Silicon carbide whisker) TWS-100 3 parts
(manufactured by Tokai Carbon Co., Ltd.)
. _ .
(Isocyanate curing agent) Barnock DN980 12 parts
Curing condition: 80C - 10 min.
- 16
(Example 7) 2~71053
(Fluoro-olefin vinyl et~er vinyl ester copolymer)
Fluonate K702 39 parts
(Molybdenum dlsulfide) Technlcal grade 54 parts
(Graphite) ACP 1000 2 parts
~Glass fiber) GP-I-O 5 parts
(manufactured by Unitika U.M. Glass Ltd.)
(Isocyanate curing agent) Barnock DN980 9.4 parts
Curing condition: 80C - 10 min.
(E~ample 8)
(Fluoro-olefin vinyl ether vinyl ester copolYmer)
Fluonate K702 28 parts
(Molybdenum disulfide) Technical grade 6S parts-
(Graphite) ACP iooo 2 parts
(Potassium titanate fiber) Tismo D 5 parts
(manufactured by Ohtsuka Chemical Industries, Ltd.)
(Isocyanate curing agent) Barnock DN980 6.7 parts
Curing condition: 80C - 10 min.
(Example 9)
(Fluoro-olefin vinyl ether vinyl ester copolymer)
Fluonate ~702 20 parts
(Molybdenum disul~lde) Technlcal grade 73 parts
(Graphlte) ACP 1000 2 parts
(Carbon fiber) Kureka chop C 5 parts
(manufactured by Kureha Chemical Industries, Ltd.)
(Isocyanate curlng agent) Barnock DN980 4.8 parts
Curing condltion: 80C - 10 min.
- 17
?n7~ ~ r?
Table - 1 .
C~ ~ar ~iv- 1 _ 3 4 5 6 7
frictional i. 7 O. 25 0 13 0.23 0.10 0.090.10
f rlctional . . . .
t~ o. 5 0 35 0.13 0.38 0.14 0. l60.15
Endur~nce life
tsliding cycles) 10 200 lOOO lOO 45000 42000 44000
Compara t ive 8 9 10 ¦11 12 13
St~tic .. .
co f(f~ci-n) 0.13 0.13 0.14 0 1 0.1 0 09
~ 0.17 0.17 0.170. lG O. 16 0 14
Enduranc- lif- .
~sliding cycl--33000 35000 3500037000 37000 39000
. .
- 18 - .
20710~
Table--2
~ e 1--2 3--4 5--6--7 .
frictiono; O. 11 0.10 O. 11 0.14 0;15 0.16 0.11
Dyn~tic
coeftic~ent O. 18 O. 17 0.16 0.19 O. 19 O. 19 D 17
Enduranco lifo
~sliding cycles120000 100000 100000 9000O 80000 80000 97000
Example ¦ 8 ¦ 9
Stotlc
frictionol O. 11 O 10
Dynotlc
frictlonol
ccef(fic~ent O. 17 0.15
Enduronc- llfo
~liding cycl-s 96000 96000
- 19--
20710S3
As has been described above, the surface coating
member according to the present inventlon has an
extremely low friction coefficient for the coating
surface and the durability of the coating layer is
remarkably high.
- 20 -
