U.S. patent application number 09/897966 was filed with the patent office on 2001-12-13 for method of producing the plated molded articles by non-electrode plating, and the resin compositions for that use.
This patent application is currently assigned to IDEMITSU PETROCHEMICAL CO., LTD.. Invention is credited to Arashi, Toshimi, Kosaka, Wataru, Tamura, Eiji.
Application Number | 20010051682 09/897966 |
Document ID | / |
Family ID | 26382720 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010051682 |
Kind Code |
A1 |
Tamura, Eiji ; et
al. |
December 13, 2001 |
Method of producing the plated molded articles by non-electrode
plating, and the resin compositions for that use
Abstract
A process for producing an electrolessly plated molded article,
which includes molding a resin composition made of a thermoplastic
resin having a specific Izod impact strength and a Rockwell surface
hardness and an inorganic filler, then treating the surface of the
molded article with air blast using an abrasive having a sharp
granular shape, and then conducting catalyst coating, activation
treatment and electroless plating. It has been possible to apply
the electroless plating with a high adhesion strength to the molded
article of the thermoplastic resin composition without conducting
the chemical etching treatment.
Inventors: |
Tamura, Eiji; (Ichihara-shi,
JP) ; Kosaka, Wataru; (Ichihara-shi, JP) ;
Arashi, Toshimi; (Ichihara-shi, JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
IDEMITSU PETROCHEMICAL CO.,
LTD.
Minato-ku
JP
|
Family ID: |
26382720 |
Appl. No.: |
09/897966 |
Filed: |
July 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09897966 |
Jul 5, 2001 |
|
|
|
09510674 |
Feb 22, 2000 |
|
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Current U.S.
Class: |
524/400 ;
524/432; 524/443 |
Current CPC
Class: |
C23C 18/1653 20130101;
C23C 18/34 20130101; H05K 2201/0209 20130101; C23C 18/40 20130101;
H05K 2201/0248 20130101; H05K 1/0373 20130101; H05K 3/181 20130101;
H05K 2203/025 20130101; C23C 18/285 20130101; C23C 18/2013
20130101; C23C 18/30 20130101; H05K 3/381 20130101; H05K 2201/09118
20130101; H05K 2201/0129 20130101 |
Class at
Publication: |
524/400 ;
524/432; 524/443 |
International
Class: |
B05D 003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 1999 |
JP |
11-042983 |
Claims
What is claimed is:
1. A process for producing an electrolessly plated molded article,
which comprises molding a resin composition made of (A) 100 parts
by weight of a thermoplastic resin having the following properties
(a1) and (a2) (a1) an Izod impact strength of 35 J/m or less, and
(a2) a surface hardness of R115 or more in terms of a Rockwell
surface hardness, and (B) 100 parts by weight or more of an
inorganic filler, then treating the surface of the molded article
with blast to make a surface roughness Rmax 15 .mu.m or more, and
thereafter conducting catalyst coating, activation treatment and
electroless plating.
2. The process for producing the electrolessly plated molded
article as claimed in claim 1, wherein the treatment with blast is
conducted by treatment with air blast using an abrasive having a
sharp granular shape.
3. A process for producing an electrolessly plated molded article,
which comprises molding a resin composition made of (A) 100 parts
by weight of a thermoplastic resin having the following properties
(a1) and (a2) (a1) an Izod impact strength of 35 J/m or less, and
(a2) a surface hardness of R115 or more in terms of a Rockwell
surface hardness, and (B) 100 parts by weight or more of an
inorganic filler, then treating the surface of the molded article
with air blast using an abrasive having a sharp granular shape, and
thereafter conducting catalyst coating, activation treatment and
electroless plating.
4. The process for producing the electrolessly plated molded
article as claimed in claim 2 or 3, wherein the abrasive having the
sharp granular shape is granulated alumina.
5. The process for producing the electrolessly plated molded
article as claimed in any one of claims 1 to 4, wherein the
thermoplastic resin is a polyarylene sulfide or a syndiotactic
polystyrene.
6. The process for producing the electrolessly plated molded
article as claimed in any one of claims 1 to 5, wherein at least a
part of the inorganic filler is a whisker.
7. The process for producing the electrolessly plated molded
article as claimed in claim 6, wherein the whisker is one type or a
combination of two or more types selected from a zinc oxide
whisker, an aluminum borate whisker and a calcium silicate
whisker.
8. A polyarylene sulfide resin composition for an electrolessly
plated molded article, which composition is made of (A') 20 to 50%
by weight of a polyarylene sulfide having a melt viscosity of 100
Pa.multidot.sec or less, (B') 5 to 50% by weight of a zinc oxide
whisker, (C') 0 to 75% by weight of a ground inorganic filler, and
(D') 0 to 50% by weight of a fiber reinforcement.
9. The polyarylene sulfide resin composition for the electrolessly
plated molded article as claimed in claim 8, wherein the ground
inorganic filler is one type or a combination of two or more types
selected from aluminum nitride, magnesium oxide, alumina and
graphite.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process for producing an
electrolessly plated molded article in which electroless plating is
applied to a molded article of a thermoplastic resin composition
made of a thermoplastic resin having a high hardness and an
inorganic filler, and a polyarylene sulfide resin composition for
the electrolessly plated molded article. More specifically, it
relates to a process for producing an electrolessly plated molded
article which dispenses with chemical etching treatment upon
polishing the surface of the hard molded article by a specific
blast method, and a polyarylene sulfide resin composition which can
preferably be used in this process.
[0003] 2. Description of the Related Art
[0004] The plating of plastics has been applied to engineering
plastics such as nylons, polyacetals, modified PPE, polycarbonates,
modified PPE/nylon and ABS/polycarbonate since it was developed
concerning an ABS resin. The plating process, namely, an
electroless plating process comprises steps of degreasing, etching,
neutralization, catalyst coating, activation and electroless
plating. Of these, especially the etching is an important step for
roughening a surface of a molded article and securing a plate
adhesion by an anchoring effect.
[0005] However, in the etching step and the neutralization step, a
mixed acid of chromic acid and sulfuric acid is used as an etching
agent in an ABS resin, and chemicals of strong acid and strong
alkali are used in other resins. Accordingly, the measures taken to
the safe environmental equipment and the quality control in the
steps have been serious problems. For example, in case of a
thermoplastic resin having a high hardness and a strong chemical
resistance, such as a polyarylene sulfide, the usual etching is
difficult, and an etching treatment in which glass fibers as the
filler are raised on the surface through blast polishing and then
eluted with hydrofluoric acid has been required.
[0006] Accordingly, a simple method that replaces the ordinary
chemical etching treatment has been in demand.
[0007] The invention aims to provide a process for producing an
electrolessly plated molded article in which electroless plating
with a great adhesion strength can be applied to a molded article
of a thermoplastic resin composition made of a thermoplastic resin
having a high hardness and an inorganic filler without conducting
chemical etching treatment, and a polyarylene sulfide resin
composition for the electrolessly plated molded article.
SUMMARY OF THE INVENTION
[0008] The present inventors have assiduously conducted
investigations to solve the problems, and have consequently found
that in a molded article obtained by mixing a polyarylene sulfide
with an inorganic filler, molding the mixture and polishing the
molded article with granulated alumina, catalyst coating smoothly
proceeds without conducting etching treatment, which results in
providing an electrolessly plated molded article having a strong
adhesion strength. This finding has led to the completion of the
invention. The summary of the invention is as follows.
[0009] (1) A process for producing an electrolessly plated molded
article, which comprises molding a resin composition made of
[0010] (A) 100 parts by weight of a thermoplastic resin having the
following properties (a1) and (a2)
[0011] (a1) an Izod impact strength of 35 J/m or less, and
[0012] (a2) a surface hardness of R115 or more in terms of a
Rockwell surface hardness, and
[0013] (B) 100 parts by weight or more of an inorganic filler, then
treating the surface of the molded article with blast to make a
surface roughness Rmax 15 .mu.m or more, and thereafter conducting
catalyst coating, activation treatment and electroless plating.
[0014] (2) The process for producing the electrolessly plated
molded article as recited in (1), wherein the treatment with blast
is conducted by treatment with air blast using an abrasive having a
sharp granular shape.
[0015] (3) A process for producing an electrolessly plated molded
article, which comprises molding a resin composition made of
[0016] (A) 100 parts by weight of a thermoplastic resin having the
following properties (a1) and (a2)
[0017] (a1) an Izod impact strength of 35 J/m or less, and
[0018] (a2) a surface hardness of R115 or more in terms of a
Rockwell surface hardness, and
[0019] (B) 100 parts by weight or more of an inorganic filler, then
treating the surface of the molded article with air blast using an
abrasive having a sharp granular shape, and thereafter conducting
catalyst coating, activation treatment and electroless plating.
[0020] (4) The process for producing the electrolessly plated
molded article as recited in (2) or (3), wherein the abrasive
having the sharp granular shape is granulated alumina.
[0021] (5) The process for producing the electrolessly plated
molded article as recited in any one of (1) to (4), wherein the
thermoplastic resin is a polyarylene sulfide or a syndiotactic
polystyrene.
[0022] (6) The process for producing the electrolessly plated
molded article as recited in any one of (1) to (5), wherein at
least a part of the inorganic filler is a whisker.
[0023] (7) The process for producing the electrolessly plated
molded article as recited in (6), wherein the whisker is one type
or a combination of two or more types selected from a zinc oxide
whisker, an aluminum borate whisker and a calcium silicate
whisker.
[0024] (8) A polyarylene sulfide resin composition for an
electrolessly plated molded article which composition is made
of
[0025] (A') 20 to 50% by weight of a polyarylene sulfide having a
melt viscosity of 100 Pasec or less,
[0026] (B') 5 to 50% by weight of a zinc oxide whisker,
[0027] (C') 0 to 75% by weight of a ground inorganic filler,
and
[0028] (D') 0 to 50% by weight of a fiber reinforcement.
[0029] (9) The polyarylene sulfide resin composition for the
electrolessly plated molded article as recited in (8), wherein the
ground inorganic filler is one type or a combination of two or more
types selected from aluminum nitride, magnesium oxide, alumina and
graphite.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The preferred embodiments of the invention are described
below.
[0031] [1] Thermoplastic Resin Having a High Hardness
[0032] The thermoplastic resin used in the invention has a high
hardness, and its properties are as follows.
[0033] (a1) an Izod impact strength of 35 J/m or less, preferably 7
to 30 J/m, and
[0034] (a2) a surface hardness of R115 or more, preferably R120 to
R128 in terms of a Rockwell surface hardness.
[0035] With respect to the Izod impact strength, a notched strength
at room temperature is measured according to ASTM D 256, using an
injection-molded piece having a size of 64.times.12.7.times.3.2 mm.
Further, the Rockwell surface hardness is measured at room
temperature (23.degree. C..+-.2.degree. C., 50%.+-.5% RH) according
to ASTM D785, using an injection-molded piece having a size of
80.times.80.times.7 mm with an R scale [as an indenter, a steel
ball having a diameter of 12.7.+-.0.0025 is used, the indenter is
put on a surface of a test piece under a test load of 60 kg
(provided a standard load is 10 kg), and a return distortion amount
of the test piece including the indenter is measured].
[0036] The thermoplastic resin used in the invention is such a hard
resin. When the Izod impact strength exceeds 3.5 J/m or the surface
hardness is less than R115 in terms of the Rockwell surface
hardness, the uneven shape of the surface on the molded article by
which to exhibit the anchoring effect is hardly provided.
[0037] Further, the resin of the invention is a thermoplastic
resin, namely a resin having such qualities that it is softened by
heating to become plastic and is hardened again by cooling. It is
contrasted with a thermosetting resin. Specific examples thereof
include linear polymers formed by an addition polymerization
reaction, such as polyethylene, polystyrene and polyvinyl chloride,
and polycondensates of difunctional monomers, such as polyesters
and nylons. Of these, specific examples of the thermoplastic resin
having the properties (a1) and (a2) include a polyarylene sulfide,
a syndiotactic polystyrene, nylon 66, nylon 6, polyethylene
terephthalate, polybutylene terephthalate, an acrylic resin and an
acrylic-styrene resin. These can be used either singly or in
combination. Of these, a polyarylene sulfide and a syndiotactic
polystyrene are especially preferable.
[0038] [1.1] Polyarylene Sulfide
[0039] The polyarylene sulfide used in the invention is a polymer
containing 70 mol % or more of a recurring unit represented by a
structural formula [--Ar--S--] wherein Ar is an arylene group and S
is sulfur. Its typical example is a polyarylene sulfide containing
70 mol % or more of a recurring unit represented by the following
structural formula (I) 1
[0040] wherein
[0041] R.sup.1 is a substituent selected from an alkyl group having
6 or less carbon atoms, an alkoxy group, a phenyl group, a
carboxylic acid or its metal salt, an amino group, a nitro group
and halogen atoms such as fluorine, chlorine and bromine, m is an
integer of 0 to 4, and n is an average degree of polymerization in
the range of 10 to 300.
[0042] When the recurring unit is less than 70 mol %, an amount of
an inherent crystalline component characteristic of a crystalline
polymer is reduced, and a mechanical strength is sometimes
unsatisfactory.
[0043] Further, a homopolymer and a copolymer are also
available.
[0044] Examples of the copolymer structural unit include an
m-phenylene sulfide unit, an o-phenylene sulfide unit, a
p,p'-diphenyleneketone sulfide unit, a p,p'-diphenylenesulfone
sulfide unit, a p,p'-biphenylene sulfide unit, a
p,p'-diphenylenemethylene sulfide unit, a p,p'-diphenylenecumenyl
sulfide unit and a naphthyl sulfide unit.
[0045] Further, the molecular structure may be a linear structure,
a branched structure or a crosslinked structure. A linear structure
is preferable.
[0046] That is, as the polyarylene sulfide of the invention,
besides a polymer having a substantially linear structure, a
polymer having a branched structure which is obtained by the
polymerization using a small amount of a monomer having three or
more functional groups as part of monomers or a crosslinked
structure can also be used. Further, it may be used by being
blended with the polymer having the substantially linear
structure.
[0047] Moreover, as the polyarylene sulfide used in the invention,
a polymer obtained by increasing a melt viscosity of a polymer of a
linear structure having a relatively low molecular weight through
oxidative crosslinking or heat crosslinking to improve a
moldability is also available.
[0048] The polyarylene sulfide used in the invention can be
produced by a known method. For example, it can be obtained by
polycondensing a dihalo aromatic compound with a sulfur source in
an organic polar solvent, and washing and drying the
polycondensate.
[0049] In addition, in the polyarylene sulfide used in the
invention, a melt viscosity at a resin temperature of 300.degree.
C. and a shear rate of 200 sec.sup.-1 is 100 Pa.multidot.sec or
less, preferably between 10 and 90 Pa.multidot.sec, more preferably
between 20 and 60 Pa.multidot.sec. When the melt viscosity exceeds
100 Pa.multidot.sec, an amount of an inorganic filler required to
form an uneven shape of a surface on a molded article by which to
exhibit an anchoring effect is reduced, and a plate peeling
strength is decreased.
[0050] The melt viscosity (Pa.multidot.sec) is measured under
conditions that a resin temperature is 300.degree. C. and a shear
rate is 200 sec.sup.-1 using Capillograph (manufactured by Toyo
Seiki K.K.).
[0051] [1.2] Syndiotactic Polystyrene
[0052] In the invention, the syndiotactic polystyrene mainly refers
to a styrenic polymer having a syndiotactic polystyrene structure.
The syndiotactic structure here referred to is a stereostructure in
which phenyl groups as side chains are alternately positioned in
the opposite direction relative to a main chain made of a
carbon-carbon bond. The tacticity is measured by the nuclear
magnetic resonance method (.sup.13C-NMR) with isotopic carbon. The
tacticity measured by the .sup.13C-NMR method can be expressed by
the ratio of plural continuous structural units. For example, when
the number of structural units is 2, the tacticity is expressed by
diad. When the number of structural units is 3, it is expressed by
triad. When the number of structural units is 5, it is expressed by
pentad. The styrenic polymer mainly having the syndiotactic
structure, referred to in the invention, is a polymer having at
least 75%, preferably at least 85% of a syndiotacticity in
racemidiad, or at least 30%, preferably at least 50% of a
syndiotacticity in racemipentad. Examples thereof include
polystyrene, a poly(alkylstyrene), a poly(halostyrene), a
poly(haloalkylstyrene), a poly(alkoxystyrene), poly(vinyl
benzoate), hydrogenated substances thereof, mixtures thereof and
copolymers containing the same as a main component. Examples of the
poly(alkylstyrene) include poly(methylstyrene), poly(ethylstyrene),
poly(isopropylstyrene), poly(tert-butylstyrene),
poly(phenylstyrene), poly(vinylnaphthalene) and poly(vinylstyrene).
Examples of the poly(halostyrene) include poly(chlorostyrene),
poly(bromostyrene) and poly(fluorostyrene). Examples of the
poly(haloalkylstyrene) include poly(chloromethylstyrene). Examples
of the poly(alkoxystyrene) include poly(methoxystyrene) and
poly(ethoxystyrene).
[0053] Of these, especially preferable examples of the styrenic
polymers include polystyrene, poly(p-methylstyrene),
poly(m-methylstyrene), poly(p-tert-butylstyrene),
poly(p-chlorostyrene), poly(m-chlorostyrene),
poly(p-fluorostyrene), hydrogenated polystyrene and copolymers
containing the structural units thereof.
[0054] The styrenic polymer mainly having the syndiotactic
structure can be produced by a known method. For example, a method
is mentioned in which a styrenic monomer (monomer corresponding to
the styrenic polymer) is polymerized in an inert hydrocarbon
solvent or in the absence of a solvent using a condensate of a
titanium compound, water and a trialkyl aluminum as a catalyst
(Japanese Patent Laid-Open No. 187708/1987). Further, the
poly(haloalkylstyrene) and the hydrogenated substance thereof can
also be obtained by a known method described in, for example,
Japanese Patent Laid-Open Nos. 46912/1989 and 178505/1989.
[0055] The molecular weight is not particularly limited. The weight
average molecular weight is at least 10,000, preferably at least
50,000. Further, the molecular weight distribution is not
particularly limited either, and various molecular weight
distributions are available. When the weight average molecular
weight is less than 10,000, thermal and mechanical properties of
the resulting composition or molded article are decreased. Thus, it
is undesirable.
[0056] These styrenic polymers having the syndiotactic structure
can be used either singly or in combination.
[0057] [2] Inorganic Filler
[0058] The type of the inorganic filler used in the resin
composition of the invention is not particularly limited. It
includes so-called ground inorganic fillers such as particulate,
granular and flaky inorganic fillers, and so-called fibrous
inorganic fillers such as a whisker, an inorganic fiber and a
metallic fiber. Specific examples of the ground inorganic fillers
include calcium carbonate, calcium sulfate, calcium phosphate,
magnesium carbonate, magnesium oxide, magnesium phosphate, talc,
mica, silica, alumina, silica alumina, kaolin, bentonite,
montmorillonite, clay, graphite, carbon black, glass beads,
titanium oxide, zirconium oxide, silicon nitride, hydrotalcite and
aluminum hydroxide. Further, specific examples of the fibrous
inorganic fillers include a glass fiber, a carbon fiber, a calcium
titanate whisker, an aluminum borate whisker, a calcium carbonate
whisker, a calcium silicate whisker (wollastonite), a calcium
sulfate whisker (zonolite), a silicon carbide whisker, a silicon
nitride whisker, a zinc oxide whisker, an alumina whisker and a
graphite whisker.
[0059] Of these, the whisker is especially preferable. As the
inorganic filler constituting the resin composition of the
invention, it is preferable that at least a part thereof is a
whisker and the remainder is the other inorganic filler.
[0060] The whisker allows the formation of the surface structure
appropriate for the catalyst coating by the treatment with blast in
the electroless plating step of the invention. Accordingly, a
plated molded article excellent in an adhesion strength in
particular can be provided.
[0061] As the whisker, a zinc oxide whisker, an aluminum borate
whisker and a calcium silicate whisker which are used either singly
or in combination are preferable. More preferable is a zinc oxide
whisker.
[0062] [3] Resin Composition Made of a Thermoplastic Resin Having a
High Hardness and an Inorganic Filler
[0063] The electrolessly plated molded article of the invention is
formed of a resin composition made of 100 parts by weight of the
thermoplastic resin having the high hardness and 100 parts by
weight or more, preferably 100 to 400 parts by weight of the
inorganic filler.
[0064] That is, when the inorganic filler is less than 100 parts by
weight, the uneven shape of the surface on the molded article by
which to exhibit the anchoring effect is hardly provided, and the
plate adhesion strength is decreased.
[0065] In the invention, the electroless plating of the invention
is applied to the molded article formed of the resin composition
having the high surface hardness. The electrolessly plated molded
article of the invention is the molded article containing such a
hard resin and the inorganic filler, so that the electroless
plating treatment to be described later acts effectively.
[0066] [4] Polyarylene Sulfide Resin Composition
[0067] The most preferable resin composition for the electrolessly
plated molded article in the invention is a polyarylene sulfide
resin composition made of
[0068] (A') 20 to 50% by weight, preferably 20 to 40% by weight of
a polyarylene sulfide having a melt viscosity of 100
Pa.multidot.sec or less, preferably 20 to 60 Pa.multidot.sec,
[0069] (B') 5 to 50% by weight, preferably 10 to 30% by weight of a
zinc oxide whisker,
[0070] (C') 0 to 75% by weight, preferably 10 to 50% by weight of a
ground inorganic filler, preferably one type or a combination of
two or more types selected from aluminum nitride, magnesium oxide,
alumina and graphite, and
[0071] (D') 0 to 50% by weight, preferably 20 to 40% by weight of a
fiber reinforcement.
[0072] The polyarylene sulfide and the zinc oxide whisker among the
molding components are the same as described above.
[0073] [4.1] Ground Inorganic Filler
[0074] The ground inorganic filler used in the polyarylene sulfide
resin composition for the electrolessly plated molded article of
the invention may be added as required in view of the adjustment of
the specific gravity of the molded article and the problem on the
end of the molded article in which the fibrous filler is not
incorporated. Examples thereof include aluminum nitride, magnesium
oxide, alumina, graphite, calcium carbonate, calcium sulfate,
calcium phosphate, magnesium carbonate, magnesium oxide, magnesium
phosphate and glass beads. Of these, aluminum nitride, magnesium
oxide, alumina and graphite which are excellent in the heat
dissipation can effectively be used to improve the plate adhesion
strength in the heat cycle of the plated article.
[0075] [4.2] Fiber Reinforcement
[0076] The fiber reinforcement used in the polyarylene sulfide
resin composition for the electrolessly plated molded article of
the invention is a fiber reinforcement except a whisker. Examples
thereof include inorganic fibers such as a carbon fiber, asbestos,
a glass robing, a glass chopped strand and a glass long fiber mat,
and metallic fibers such as a copper fiber, a titanium fiber, an
aluminum fiber and an iron fiber.
[0077] [4.3] Formulation
[0078] When the amount of the polyarylene sulfide as component (A')
is less than 20% by weight, the fluidity is notably decreased. When
it exceeds 50% by weight, the uneven shape of the surface on the
molded article by which to exhibit the anchoring effect is hardly
provided, and the plate adhesion strength is decreased. Further,
when the amount of the zinc oxide whisker as component (B') is less
than 5% by weight, the plate adhesion strength is decreased. When
it exceeds 50% by weight, the fluidity is notably decreased. Still
further, when the amount of the ground inorganic filler as
component (C') exceeds 75% by weight, the fluidity is notably
decreased. When the amount of the fiber reinforcement as component
(D') exceeds 50% by weight, the fluidity is notably decreased.
[0079] The polyarylene sulfide resin composition for the
electrolessly plated molded article of the invention may contain,
in addition to the foregoing components, the other components as
required unless the effects of the invention are impaired. Examples
of the other components include additives such as an antioxidant, a
weathering agent, a lubricant, a plasticizer, an antioxidant and a
colorant, thermoplastic resins and/or thermosetting resins such as
a polyamide, an epoxy resin, a silicone resin, silicone oil, a
polyolefin, a polyether sulfone and a polyphenylene ether, rubbers
such as hydrogenated SBS, hydrogenated NBR, silicone rubber and
fluororubber, and a pigment.
[0080] The polyarylene sulfide resin composition of the invention
can be obtained by mixing components (A'), (B'), (C') and (D') with
the additives as required, and melt-kneading the mixture with a
Henschel mixer and a twin-screw extruder usually at 280 to
350.degree. C.
[0081] [5] Process for Producing an Electrolessly Plated Molded
Article
[0082] A process for producing an electrolessly plated molded
article in the invention comprises forming the molded article, then
treating the molded article with blast to make the surface
roughness Rmax approximately 15 .mu.m or more, and thereafter
conducting catalyst coating, activation treatment and electroless
plating.
[0083] That is, it is a process for producing an electrolessly
plated molded article which process dispenses with the chemical
etching step that has been so far inevitable by the treatment with
blast.
[0084] The steps in the production of the electrolessly plated
molded article in the invention are described in detail below.
First, it is required that the surface of the molded article is
polished by treating the molded article with air blast using an
abrasive having a sharp granular shape until the surface roughness
Rmax reaches approximately 15 .mu.m or more. The abrasive having
the sharp granular shape is not particularly limited so long as it
is a general abrasive having a blocky or sharp granular shape.
Further, the granular shape of many abrasives is known to depend on
the granulating conditions of the granulating step in the
production stage. Accordingly, it can usually be selected from
crude granules obtained from molten alumina, burnt alumina, silica
rock and a molten mixture of chromium oxide and burnt alumina which
have been ordinarily used for air blast treatment of processed
products of plastics, brass, aluminum and zinc diecast. Of these,
granulated alumina can preferably be used. It is thus inevitable to
use the abrasive having the sharp granular shape. When beads of
glass or metals having a round corner in contrast with this is used
as an abrasive, no satisfactory effect is provided.
[0085] The molded article thus treated with air blast
satisfactorily exhibits the same effect as that given by the
chemical etching, and then subjected to the catalyst coating
step.
[0086] The steps of from the catalyst coating to the electroless
plating are conducted by methods known so far. For example, in the
catalyst coating step, a molded article to be treated is dipped in
a colloidal solution containing tin ions and palladium ions at room
temperature for 2 to 5 minutes. Subsequently, the tin layer coated
on the surface of palladium is removed, and the activation
treatment is conducted for exhibiting the function of the palladium
catalyst. Specifically, the molded article is treated with a strong
acid such as sulfuric acid or hydrochloric acid. The catalyst here
functions to adsorb nickel or copper metal precipitated, and this
function enables the plating. In case of the nickel plating, an
electroless plating bath (pH 9.0 to 9.5, 25 to 35.degree. C.)
comprising 30 g/liter of nickel sulfate as a metal salt, 40 g/liter
of sodium citrate as a complexing agent, 20 g/liter of sodium
phosphite as a reducing agent and 25 ml/liter of ammonia as a pH
adjustor is ordinarily used. When the molded article to be treated
is dipped in this electroless plating bath, metallic ions reduced
with the reducing agent are precipitated on the surface as metals.
This electroless plating treatment usually provides a plate having
a thickness of 0.2 to 0.5 .mu.m in 5 to 10 minutes.
[0087] The process for producing the electrolessly plated molded
article in the invention is characterized by the specific treatment
with blast which dispenses with the chemical etching that has been
so far an indispensable step. Especially when a molding material
made of a polyarylene sulfide and an inorganic filler is used,
deburring that occurs in the molding is indispensable. Accordingly,
it is quite advantageous that the deburring can be conducted in the
extended stage of the treatment with blast.
[0088] The invention is illustrated more specifically with
reference to Examples.
[0089] The test methods used in Examples are as follows.
[0090] (1) Measurement of a Surface Roughness
[0091] Rmax was measured according to JIS B 0601 using a surface
roughness measuring unit (Surf Coder SE-307 manufactured by Kosaka
Kenkyusho).
[0092] (2) Evaluation of an Adhesion Strength of a Plated Film
(Peeling Strength at Room Temperature)
[0093] Parallel cuts having a width of 10 mm were applied to the
plated surface of the plated sample, and one end was peeled off
from the substrate by approximately 20 mm. The peeled portion was
installed on a tensile tester, and the tester was actuated at a
rate of 25 mm/min such that the plate was uniformly peeled off to
obtain a peeling strength (kgf/cm).
[0094] When the plate was not deposited, it was expressed by x.
When the adhesion strength was less than 1.0 kgf/cm, the plate was
of no practical use as a plated film.
[0095] (3) Evaluation of an Adhesion Strength (Peeling Strength) in
a Heat Shock Test of a Plated Film
[0096] A heat cycle tester manufactured by Tabai Espec was used. A
heat cycle condition was that one cycle was -30.degree. C. (1
hour), 20.degree. C. (1 hour), 80.degree. C. (1 hour) and
20.degree. C. (1 hour) and this cycle was repeated 200 times. The
resulting plated sample was measured for the peeling strength in
the same manner as in (2). When a plate was not deposited, it was
expressed by x. When the adhesion strength was 0.3 kgf/cm or less,
the peeling of the plated film was sometimes observed.
[0097] Further, the components used in Examples are as follows.
[0098] (a) Resin
[0099] PPS: polyphenylene sulfide
[0100] IPC-1 (made by Idemitsu Petrochemical Co., Ltd.), melt
viscosity (300.degree. C., 200 sec.sup.-1) 30 Pa.multidot.sec, Izod
impact strength 12 J/m, Rockwell hardness R120
[0101] IPC-3 (made by Idemitsu Petrochemical Co., Ltd.), melt
viscosity (300.degree. C., 200 sec.sup.-1) 90 Pa.multidot.sec, Izod
impact strength 18 J/m, Rockwell hardness R120
[0102] IPC-6 (made by Idemitsu Petrochemical Co., Ltd.), melt
viscosity (300.degree. C., 200 sec.sup.-1) 500 Pa.multidot.sec,
Izod impact strength 40 J/m, Rockwell hardness R120
[0103] SPS: syndiotactic polystyrene
[0104] 130 Z (made by Idemitsu Petrochemical Co., Ltd.), Izod
impact strength 15 J/m, Rockwell hardness R116
[0105] PA66: nylon 66
[0106] Leona 1200S (made by Asahi Chemical Industry Co., Ltd.),
Izod impact strength 34 J/m, Rockwell hardness R120
[0107] (b) Whisker
[0108] Potassium titanate: Tismo D101 (made by Otsuka Kagaku
K.K.)
[0109] Zinc oxide: Panatetra 0511 (made by Matsushita Amtec)
[0110] Aluminum borate: Alborex YS2A (made by Shikoku Kasei
Kogyo)
[0111] Calcium silicate: NYGLOS (made by Nyco)
[0112] (c) Ground Inorganic Filler
[0113] CaCO.sub.3: Whiton P-30 (made by Shiraishi Kogyo K.K.)
[0114] Al2O.sub.3: AL-43 PC (made by Showa Denko K.K.)
[0115] MgO: Pyrokisma 3320 (made by Kyowa Kagaku Kogyo K.K.)
[0116] (d) Fiber Reinforcement
[0117] GF (glass fiber): 03JAFT591 (made by Asahi Fiber Glass Co.,
Ltd.)
EXAMPLE 1
[0118] A flat plate having a size of 80.times.80.times.3.2 mm was
obtained by injection molding with an injection-molding machine
(J50E-P manufactured by The Japan Steel Works, Ltd.) using a
molding material comprising (a) 50% by weight of polyphenylene
sulfide [IPC-3 made by Idemitsu Petrochemical Co., Ltd., melt
viscosity (300.degree. C., 200 sec.sup.-1) 90 Pa.multidot.sec, Izod
impact strength 18 J/m, Rockwell hardness R120], (b) no whisker,
(c) no ground inorganic filler and (d) 50% by weight of a glass
fiber as a fiber reinforcement according to the formulation shown
in Table 1. For applying the electroless copper plating to this
molded article, the molded article was first treated with blast.
The polishing treatment with blast was conducted with Ascon Blast
Cabinet B-O model manufactured by Atsuji Tekko K.K. as a blast
treatment device using glass beads ("GB" for short) (J-70
manufactured by Toshiba-Ballotini Co., Ltd., particle diameter 350
to 180 .mu.m), stainless beads (SB for short) (CHRONITAL No. 30
manufactured by Keetel, particle diameter 140 to 150 .mu.m) and
alumina ("WA" for short) (NISSORUNDUM 50A WA #150 manufactured by
Taiheiyo Random K.K.) as an abrasive respectively. The treatment
with blast was conducted at a blast pressure of 3 kg/cm.sup.2 upon
setting a distance between an end of a jet nozzle and a flat plate
of a molded article at approximately 5 cm. Then, the surface
roughness Rmax was 18 .mu.m.
[0119] Thereafter, the molded article subjected to the treatment
with blast was dipped in a colloidal solution containing tin ions
and palladium ions at room temperature for approximately 3 minutes.
Then, in order to remove the tin layer coated on the surface of
palladium, the activation treatment for exhibiting the function of
the palladium catalyst was conducted using hydrochloric acid. The
molded article subjected to the activation treatment was dipped in
the electroless copper plating bath.
[0120] The electroless copper plating bath was made of 10 g/liter
of copper sulfate as a metal salt, 50 g/liter of Rochelle salt as a
complexing agent, 10 ml/liter of formalin as a reducing agent and
10 g/liter of sodium hydroxide as a pH adjustor. The treatment was
conducted with a pH of 12 at a temperature of 25.degree. C. for a
dipping time of 8 minutes. The plated film thickness of the
resulting electrolessly plated molded article was approximately 1
.mu.m on average.
[0121] Further, for applying the electroplating to the molded
article, it was placed in an electrolyte of copper sulfate as an
electrode plate, and a current having a low current density of
approximately 0.5 A/cm.sup.2 was passed to conduct strike plating
with a plated film thickness of approximately 3 .mu.m. The
resulting plated molded article was then washed with water.
Subsequently, copper plating, water-washing, nickel substrate
plating and water-washing were repeated again. The plate of the
uppermost layer was washed with water, and finished by drying. The
copper plating was applied to the uppermost layer, and the
thickness of the final plated film was approximately 25 .mu.m.
[0122] The samples in which three types of abrasives were used
respectively were evaluated with respect to the adhesion of the
plated film at room temperature and the adhesion in the heat cycle.
The results of the evaluations are shown in Table 2.
EXAMPLES 2 TO 10 AND COMPARATIVE EXAMPLES 1 TO 4
[0123] According to the formulation shown in Table 1, a molding
material was prepared as in Example 1, and molded into a flat
plate. Then, the flat plate was subjected to the electroless copper
plating and the final copper electroplating.
[0124] The samples in which three types of abrasives were used
respectively were evaluated with respect to the adhesion of the
plated film at room temperature and the adhesion in the heat cycle.
The results of the evaluations are shown in Table 2.
1TABLE 1 (unit: wt. %) Calcium Aluminum Calcium PPS titanate Zinc
oxide borate silicate Ground filler IPC-1 IPC-3 IPC-6 SPS PA66
whisker whisker whisker whisker CaCO.sub.3 Al.sub.2O.sub.3 MgO GF
Example 1 50 50 Example 2 30 40 30 Example 3 30 15 25 30 Example 4
30 15 25 30 Example 5 30 15 25 30 Example 6 30 25 30 Example 7 40
50 15 10 Example 8 50 50 Example 9 30 20 10 40 Example 10 30 10 40
20 Example 11 30 40 30 Comparative 70 30 Example 1 Comparative 100
Example 2 Comparative 100 Example 3 Comparative 60 40 Example 4
[0125]
2TABLE 2 (unit: kgf/cm) Plate adhesion strength Plate adhesion
strength at room temperature in heat cycle Type of abrasive Type of
abrasive GB SB WA GB SB WA Example 1 x x 1.0 - - 0.5 Example 2 x x
1.2 - - 0.8 Example 3 x x 1.3 - - 0.9 Example 4 x x 1.5 - - 1.0
Example 5 x x 1.5 - - 1.0 Example 6 x x 1.5 - - 1.0 Example 7 x x
1.0 - - 0.7 Example 8 x x 1.0 - - 0.5 Example 9 x x 1.5 - - 1.3
Example 10 x x 1.8 - - 1.6 Example 11 x x 1.1 - - 0.8 Comparative x
x 0.3 - - <0.1 Example 1 Comparative x x <0.1 - - <0.1
Example 2 Comparative x x <0.1 - - <0.1 Example 3 Comparative
x x 0.8 - - 0.4 Example 4
[0126] In the molded articles obtained by the treatment with blast
using the abrasive having the sharp shape in the invention and
having the adhesion strength of the plated film which is clearly
exhibited depending on the type of the abrasive, the formation of
the plated film having the high adhesion strength is observed.
Meanwhile, in the molded articles treated with blast using the
abrasive beads, the formation of the plated film is not observed.
In the molded articles obtained by the treatment with blast using
the abrasive having the sharp shape as shown in Comparative
Examples 1 to 4, when the amount of the inorganic filler is less
than 50% by weight, no satisfactory adhesion strength of the plated
film is provided. By the way, as shown in Examples 3 to 7, 9 and 10
in which the whisker is used as the inorganic filler, the adhesion
strength of the plated film is especially high. Further, in Example
10, the adhesion strength in the heat cycle is especially high due
presumably to the effect provided by MgO having the good heat
dissipation.
* * * * *