U.S. patent application number 11/711264 was filed with the patent office on 2007-07-12 for cladding resin composition.
This patent application is currently assigned to Dai-Ichi Kogyo Seiyaku Co., Ltd.. Invention is credited to Shigeo Mori, Tetsuo Shiraiwa.
Application Number | 20070161772 11/711264 |
Document ID | / |
Family ID | 13618296 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070161772 |
Kind Code |
A1 |
Shiraiwa; Tetsuo ; et
al. |
July 12, 2007 |
Cladding resin composition
Abstract
The invention relates to a cladding resin composition curable by
heat, ultraviolet radiation, an electron beam or the like. The
composition comprises a polyoxyalkylene polyol phosphate ester
(hydroxyl value: 10-2,000 mg KOH/g) and a polymerizable or reactive
functional group-containing compound. This composition is highly
conductive as it is and, without incorporation of the conventional
conductive additives, can be used successfully in the field of
coatings and protective films where electric conductivity is a
requisite.
Inventors: |
Shiraiwa; Tetsuo; (Ikoma,
JP) ; Mori; Shigeo; (Nishikyo-ku, JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET
SUITE 4000
NEW YORK
NY
10168
US
|
Assignee: |
Dai-Ichi Kogyo Seiyaku Co.,
Ltd.
Kyoto-shi
JP
|
Family ID: |
13618296 |
Appl. No.: |
11/711264 |
Filed: |
February 27, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10404275 |
Apr 1, 2003 |
7189444 |
|
|
11711264 |
Feb 27, 2007 |
|
|
|
08811068 |
Mar 3, 1997 |
6552159 |
|
|
10404275 |
Apr 1, 2003 |
|
|
|
08434305 |
May 2, 1995 |
|
|
|
08811068 |
Mar 3, 1997 |
|
|
|
07831139 |
Feb 4, 1992 |
|
|
|
08434305 |
May 2, 1995 |
|
|
|
Current U.S.
Class: |
528/45 ; 528/271;
528/272; 528/287; 528/297; 528/392; 528/397; 528/80; 528/89 |
Current CPC
Class: |
C09D 175/08 20130101;
C08L 63/00 20130101; C08G 18/8077 20130101; C08L 2666/22 20130101;
C08G 18/5084 20130101; Y10T 428/2964 20150115; Y10T 428/2973
20150115; H01B 1/12 20130101; C08G 18/10 20130101; C08G 18/672
20130101; Y10T 428/161 20150115; C08G 65/327 20130101; C08G 18/10
20130101; C08L 63/00 20130101 |
Class at
Publication: |
528/045 ;
528/080; 528/089; 528/271; 528/272; 528/287; 528/297; 528/392;
528/397 |
International
Class: |
C08G 18/81 20060101
C08G018/81 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 1991 |
JP |
3-76892 |
Claims
1. A cladding resin composition comprising the reaction product of:
a polyoxyalkylene polyol phosphate ester, having a hydroxyl value
of 10-2,000 mg KOH/g; and at least one compound selected from the
group consisting of: polyisocyanates, active hydrogen-containing
(meth)acrylates, (meth)acrylic acid, and maleic anhydride.
2. The cladding resin composition according to claim 1, wherein
said at least one compound and said polyoxyalkylene polyol
phosphate ester are in a molar ratio of the former to the latter of
1:1 to 10:1.
3. The cladding resin composition according to claim 1, wherein
said active hydrogen-containing (meth)acrylate is a dihydric
alcohol mono(meth)acrylate.
4. The cladding resin composition according to claim 1, wherein
said active hydrogen-containing (meth)acrylate is at least one
member selected from the group consisting of: ethylene glycol
mono(meth)acrylate, propylene glycol mono(meth)acrylate, and
diethylene glycol mono(meth)acrylate.
5. A resin composition comprising a polyoxyalkylene polyol
phosphate ester, having a hydroxyl value of 10-780 mg KOH/g, and
one or more polymerizable or reactive functional group-containing
compounds capable of reacting with the phosphate ester and/or with
a metal salt derived from said phosphate ester, to produce a cured
coating, wherein a molar ratio of said one or more polymerizable or
reactive functional group-containing compounds to said
polyoxyalkylene polyol phosphate ester is 1:1 to 10:1.
6. The resin composition according to claim 5, wherein said one or
more polymerizable or reactive functional group-containing
compounds is at least one member selected from the group consisting
of active hydrogen-containing (meth)acrylates, (meth)acrylic acid,
and maleic anhydride.
7. The resin composition according to claim 5, wherein said metal
salt is an alkali metal salt.
8. The resin composition according to claim 7, wherein said alkali
metal salt is a sodium, potassium, or lithium salt.
9. A film or coating comprising the reaction product of: a
polyoxyalkylene polyol phosphate ester, having a hydroxyl value of
10-2,000 mg KOH/g; and at least one compound selected from the
group consisting of: polyisocyanates, active hydrogen-containing
(meth)acrylates, (meth)acrylic acid, and maleic anhydride, wherein
said dry film or coating is substantially free of solid
particles.
10. The film or coating according to claim 9, wherein said at least
one compound and said polyoxyalkylene polyol phosphate ester are in
a molar ratio of the former to the latter of 1:1 to 10:1.
11. The film or coating according to claim 9, wherein said active
hydrogen-containing (meth)acrylate is a dihydric alcohol
mono(meth)acrylate.
12. The film or coating according to claim 9, wherein said active
hydrogen-containing (meth)acrylate is at least one member selected
from the group consisting of: ethylene glycol mono(meth)acrylate,
propylene glycol mono(meth)acrylate, and diethylene glycol
mono(meth)acrylate.
13. A film or coating comprising a polyoxyalkylene polyol phosphate
ester, having a hydroxyl value of 10-780 mg KOH/g, and one or more
polymerizable or reactive functional group-containing compounds
capable of reacting with the phosphate ester and/or with a metal
salt derived from said phosphate ester, to produce a cured coating,
wherein a molar ratio of said one or more polymerizable or reactive
functional group-containing compounds to said polyoxyalkylene
polyol phosphate ester is 1:1 to 10:1, wherein said film or coating
is substantially free of solid particles.
14. The film or coating according to claim 13, wherein said one or
more polymerizable or reactive functional group-containing
compounds is at least one member selected from the group consisting
of active hydrogen-containing (meth)acrylates, (meth)acrylic acid,
and maleic anhydride.
15. The film or coating according to claim 13, wherein said metal
salt is an alkali metal salt.
16. The film or coating according to claim 15, wherein said alkali
metal salt is a sodium, potassium, or lithium salt.
Description
REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application of Ser. No. 10/404,275,
filed Apr. 1, 2003, which is currently allowed and which is in
turn, a continuation application of Ser. No. 08/811,068, filed Mar.
3, 1997, currently issued and which is a continuation application
of Ser. No. 08/434,305, filed May 2, 1995, currently abandoned and
is a continuation application of Ser. No. 07/831,139, filed Feb. 4,
1992, currently abandoned. The subject matter of the aforementioned
prior applications are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a cladding resin
composition which can be cured by heat, ultraviolet light or an
electron beam.
[0003] In the conventional resin composition for cladding purposes,
improvement of the electric conductivity of the cured film has been
sought by incorporating a conductive substance such as carbon
black, and graphite or the like.
[0004] However, the practice requires a large quantity of such
conductive substance and this causes problems in dispersibility and
entails physical degradation of the resin.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to overcome the
above-mentioned disadvantages and provide a highly conductive
cladding resin composition without involving addition of such
conventional conductive substance.
[0006] The present invention is, therefore, concerned with a
cladding resin composition comprising a polyo yalkylene polyol
phosphate ester (hydroxyl value: 10-2,000 mg KOH/g) and a
polymerizable or reactive functional group-containing compound.
Reactive functional group-containing compounds include ones that
are polymerizable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] The polyoxyalkylene polyol to be used in accordance with the
invention can be prepared, for example by addition-polymerizing an
alkylene oxide and/or a glycidyl ether with an active hydrogen
compound in the presence of a catalyst and removing the catalyst by
a per se known purification procedure such as ion exchange,
neutralization filtration, adsorption and so on. This
polyoxyalkylene polyol preferably has a molecular weight of 200 to
10,000.
[0008] The active hydrogen compound mentioned above includes
various compounds each having two or more active hydrogen atoms,
such as polyhydric alcohols, e.g. ethylene glycol, propylene
glycol, 1,4-butanediol, glycerol, trimethylolpropane, sorbitol,
sucrose, etc., amine compounds, e.g. monoethanolamine,
ethylenediamine, diethylenetriamine, 2-ethylhexylamine,
hexamethylenediamine, etc., and phenolic active hydrogen compounds
such as bisphenol A, hydroquinone and so on.
[0009] The alkylene oxide mentioned above includes, among others,
ethylene oxide, propylene oxide, butylene oxide, hexene oxide,
cyclohexene oxide, nonene oxide, and .mu.-olefin oxides containing
12 to 28 carbon atoms.
[0010] The glycidyl ether mentioned above includes, among others,
methyl glycidyl ether, butyl glycidyl ether, allyl glycidyl ether,
phenyl glycidyl ether and so on.
[0011] In the addition-polymerization to the active hydrogen
compound, either an alkylene oxide or a glycidyl ether or both may
be reacted and, in the latter (copolymerization) case, the order of
addition is optional. As the catalyst for this
addition-polymerization reaction, a basic catalyst such as sodium
methoxide, sodium hydroxide, potassium hydroxide, lithium
carbonate, etc. is generally employed but a Lewis acid catalyst
such as boron trifluoride or an amine catalyst such as
trimethylamine, triethylamine, etc. is also useful. The amount of
such catalyst can be the amount generally employed.
[0012] The polyoxyalkylene polyol may be partially substituted by a
halogen, such as chlorine and/or bromine.
[0013] For phosphorylation of such polyoxyalkylene polyol, a
phosphorus compound such as diphosphorus pentoxide, phosphoryl
trichloride or the like is employed.
[0014] The phosphorylation reaction is conducted in the routine
manner and the proportions of the polyoxy-alkylene polyol and
phosphorus compound are such that the product phosphate ester will
have a hydroxyl value in the range of 10 to 2,000 mg KOH/g. This
phosphate ester may be partially converted to a metal salt, such as
an alkali metal salt, e.g. lithium salt, sodium salt or potassium
salt. Such a metal salt can be prepared by neutralizing the
phosphate ester with an basic alkali metal compound such as lithium
hydroxide, sodium hydroxide or potassium hydroxide.
[0015] The polymerizable or reactive functional group-containing
compound includes, among others, various polyisocyanates,
unsaturated compounds such as active hydrogen-containing
(meth)acrylates, (meth)acrylic acid, maleic anhydride, etc.,
glycidyl ether compounds and so on, and these compounds can be used
alone or in combination.
[0016] Throughout this specification, (meth)acrylic acid means
acrylic acid and/or methacrylic acid, while (meth)acrylate
represents acrylate and methacrylate.
[0017] The polyisocyanate compound includes, among others,
2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate
(2,6-TDI), 4,4'-diphenylmethane diisocyanate (MDI), hexamethylene
diisocyanate (HMDI), isophorone diisocyanate, etc. as well as
mixtures thereof. Polyisocyanates having polyoxyalkylene chains can
also be employed.
[0018] The polyisocyanate compounds may be used in the form of
blocked isocyanates. The blocking agent which can be used for this
purpose includes methyl ethyl ketoxime, phenol, caprolactam, ethyl
acetoacetate, methanol, sodium hydrosulfite and so on. The blocking
can be achieved by adding such a blocking agent to a polyisocyanate
and reacting the mixture at 30-90.degree. C. for 0.5 to 2
hours.
[0019] The active hydrogen-containing (meth)acrylate includes,
among others, dihydric alcohol mono(meth)-acrylates such as
ethylene glycol mono(meth)acrylate, propylene glycol
mono(meth)acrylate, diethylene glycol mono(meth)acrylate and so
on.
[0020] The glycidyl ether compound includes, among others, ethylene
glycol diglycidyl ether, polypropylene glycol diglycidyl ether,
polyethylene glycol diglycidyl ether, trimethylolpropane diglycidyl
ether and sorbitol polyglycidyl ether.
[0021] The polyoxyalkylene polyol phosphate ester and the
polymerizable or reactive functional group-containing compounds
react with each other to give a cured product. When two or more
different polymerizable or reactive functional group-containing
compounds are employed, all of them may be reacted concurrently or
one or more of them be reacted in the first place, with the
remainder being reacted thereafter. The proportion of the
polymerizable or reactive functional group-containing compound is
1.0 to 10.0 moles per mole of the phosphate ester.
[0022] The catalyst for this reaction is selected according to the
kind of polymerizable or reactive functional group-containing
compound. In the case of polyisocyanates, there may be employed
organometal catalysts such as dibutyltin dilaurate, dibutyltin
diacetate, ephenylmercury propionate, lead octenoate, etc. and
amine catalysts such as triethylenediamine,
N,N'-dimethyl-piperazine, N-methylmorpholine, tetramethylguanidine,
triethylamine, etc. In the case of (meth)acrylic acid, sulfuric
acid and p-toluenesulfonic acid may be employed and, where
necessary, polymerization inhibitors such as hydroquinone,
hydroquinone monomethyl ether, etc. can be employed in
conjunction.
[0023] In the cladding resin composition of the invention, said
phosphate ester and polymerizable or reactive functional
group-containing compound react with each other to give a cured
resin. This reaction can be induced by heat, ultraviolet light, an
electron beam or the like and, where necessary, a polymerization
initiator and a sensitizer may also be used.
[0024] Since the cladding resin composition of the invention is
highly conductive, it is no longer necessary to incorporate the
conventional conductive substance and the composition can be used
advantageously in the field of coatings and protective films, etc.
where electric conductivity is a requisite.
[0025] The following examples and comparative examples are further
illustrative and by no means limitative of the invention.
EXAMPLE 1
[0026] A 5 l autoclave was charged with 920 g of glycerol and 12 g
of potassium hydroxide. Then, 2,500 g of propylene oxide and 700 g
of ethylene oxide were successively introduced and reacted at
120.degree. C. for 6 hours. The reaction was further continued at
the same temperature for 3 hours. The reaction product was then
purified to give 3,900 g of a polyoxyalkylene polyol (A-1) having a
molecular weight (calculated from the OH value) of 400.
[0027] To 200 g of the above polyoxyalkylene polyol (A-1) was added
24 g of diphosphorus pentoxide and the reaction was carried out at
70.degree. C. with stirring for 3 hours to give a phosphate ester
(B-1) (OH value: 310 mg KOH/g, viscosity: 480 cps/25.degree.
C.).
[0028] To 100 g of the above phosphate ester (B-1) were added 48 g
of 2,4-tolylene diisocyanate, 0.05 g of dibutyltin dilaurate and 50
g of methyl ethyl ketone to provide a cladding resin composition.
This composition was coated on an aluminum sheet (JIS K5400; 50 mm
.times.50 mm .times.1 mm; the same applies hereafter) and caused to
dry and cure at 150.degree. C. for 30 minutes to give a test sample
(S-1) having a coating thickness of 20 .mu.m.
EXAMPLE 2
[0029] A 5 l autoclave was charged with 920 g of glycerol and 4 g
of potassium hydroxide. Then, 1,200 g of ethylene oxide was
introduced at 130.degree. C. for 3 hours. The reaction was further
continued at the same temperature for 1 hour. The reaction product
was then purified to give 1,900 g of a polyoxyalkylene polyol (A-2)
having a molecular weight (calculated from the OH value) of
200.
[0030] To 200 g of this polyoxyalkylene polyol (A-2) was added 34 g
of diphosphorus pentoxide and the reaction was conducted at
70.degree. C. with stirring for 3 hours to give a phosphate ester
(B-2) (OH value: 780 mg KOH/g, viscosity: 360 cps/25.degree. C.).
To 100 g of a polyethylene glycol having a molecular weight of 400
was added 84 g of hexamethylene diisocyanate and the mixture was
reacted at 90.degree. C. with stirring for 4 hours. Then, 44 g of
methyl ethyl ketoxime was added and the reaction was conducted at
60.degree. C. for 30 minutes to give a blocked isocyanate.
[0031] To 100 g of the phosphate ester (B-2) prepared above were
added 512 g of this blocked isocyanate, 0.2 g of dibutyltin
dilaurate and 300 g of methyl ethyl ketone to prepare a cladding
resin composition. This composition was coated on an aluminum sheet
and caused to dry and cure at 150.degree. C. for 30 minutes to give
a test sample (S-2) having a coating thickness of 20 .mu.m.
EXAMPLE 3
[0032] A 5 autoclave was charged with 390 g of trimethylolpropane
and 5 g of potassium hydroxide, and 2,100 g of ethylene oxide was
introduced at 130.degree. C. for 4 hours. The reaction was further
continued at the same temperature for 1 hour. The reaction product
was then purified to give 2,100 g of a polyoxyalkylene polyol (A-3)
having a molecular weight (calculated from the OH value) of
800.
[0033] To 200 g of this polyoxyalkylene polyol (A-3) was added 10 g
of pyridine, followed by addition of 6 g of phosphoryl trichloride
with stirring. The reaction was carried out at 70.degree. C. for 3
hours. After purification, 10 g of 10% aqueous solution of lithium
hydroxide was added. Dehydration gave a phosphate ester (B-3)
(hydroxyl value: 150 mg KOH/g, viscosity: 590 cps/25.degree. C.).
This phosphate ester had been partially converted to the lithium
salt.
[0034] To 100 g of the above phosphate ester (B-3) were added 22 g
of hexamethylene diisocyanate and 50 g of methyl ethyl ketone to
give a cladding resin composition. This composition was coated on
an aluminum sheet and caused to dry and cure at 150.degree. C. for
30 minutes to give a test sample (S-3) having a coating thickness
of 20 .mu.m.
EXAMPLE 4
[0035] A 5 l autoclave was charged with 100 g of bisphenol A and 6
g of potassium hydroxide, and 1,500 g of ethylene oxide was
introduced at 130.degree. C. for 3 hours. The reaction was further
continued for 1 hour and the reaction product was purified to give
2,300 g of a polyoxyalkylene polyol (A-4) having a molecular weight
(calculated from the OH value) of 500.
[0036] To 200 g of this polyoxyalkylene polyol (A-4) was added 10 g
of diphosphorus pentoxide and the reaction was conducted at
70.degree. C. with stirring for 3 hours to give a phosphate ester
(B-4) (hydroxyl value: 140 mg KOH/g, viscosity: 530 cps/25.degree.
C.).
[0037] To 100 g of the above phosphate ester (B-4) was added 43 g
of 2,4-tolylene diisocyanate and the mixture was reacted at
90.degree. C. with stirring for 3 hours. Then, 30 g of ethylene
glycol monomethacrylate was added and the mixture was further
stirred under heating for 3 hours. Then, 5.2 g of a
photopolymerization initiator (IRGACURE 184) was added to give a
cladding resin composition. This composition was coated on an
aluminum sheet and irradiated with ultraviolet light (lamp: 80
W/cm.times.1, distance from the lamp: 8 cm) to provide a test
sample (S-4) having a coating thickness of 20 .mu.m.
EXAMPLE 5
[0038] A 5 l autoclave was charged with 136 g of pentaerythritol
and 10 g of potassium hydroxide. Then, 2,000 g of 1,2-butylene
oxide and 500 g of methyl glycidyl ether were successively
introduced at 110.degree. C. over 5 hours. The reaction was further
continued at the same temperature for 3 hours. The reaction product
was then purified to give 2,300 g of a polyoxyalkylene polyol (A-5)
having a molecular weight (calculated from the OH value) of
2,500.
[0039] To 200 g of this polyoxyalkylene polyol (A-5) was added 6 g
of diphosphorus pentoxide and the mixture was reacted at 70.degree.
C. with stirring for 3 hours to give a phosphate ester (B-5)
(hydroxyl value: 65 mg KOH/g, viscosity: 620 cps/25.degree.
C.).
[0040] To 100 g of the above phosphate ester (B-5) were added 20 g
of acrylic acid, 50 g of benzene and 1 g of sulfuric acid and the
reaction was conducted at 80-90.degree. C. with air bubbled through
the system. The end point of the reaction was confirmed from the
volume of water withdrawn and the acid value. The reaction mixture
was then neutralized with aqueous sodium hydroxide solution and
washed with a saturated aqueous solution of sodium sulfate. After
the benzene was distilled off under reduced pressure, 1 g of
2,2'-azobisisobutyronitrile (polymerization initiator) was added to
give a cladding resin composition. This composition was coated on
an aluminum sheet and caused to cure at 120.degree. C. for 3 hours
to provide a test sample (S-5) having a coating thickness of 20
.mu.m.
EXAMPLE 6
[0041] A 5 l autoclave was charged with 45 g of glycerol and 16 g
of potassium hydroxide, and 3,000 g of 1,2-butylene oxide and 1,500
g of ethylene oxide were successively introduced at 120.degree. C.
for 8 hours. The reaction was further continued at the same
temperature for 3 hours. The reaction product was then purified to
give 4,100 g of a polyoxyalkylene polyol (A-6) having a molecular
weight (calculated from the OH value) of 8,000.
[0042] To 200 g of this polyoxyalkylene polyol (A-6) was added 4 g
of diphosphorus pentoxide and the mixture was reacted at 70.degree.
C. with stirring for 3 hours to give a phosphate ester (B-6)
(hydroxyl value: 18 mg KOH/g, viscosity: 920 cps/25.degree.
C.).
[0043] To 100 g of the above phosphate ester (B-6) were added 10 g
of ethylene glycol diglycidyl ether and 1 g of diethylenetriamine
(curing catalyst) to give a cladding resin composition. This
composition was coated on an aluminum sheet and caused to cure at
120.degree. C. for 5 hours to provide a test sample (S-6) having a
coating thickness of 20 .mu.m.
COMPARATIVE EXAMPLE 1
[0044] To 100 g of the polyoxyalkylene polyol (A-1) prepared in
Example 1 were added 65 g of 2,4-tolylene diisocyanate, 0.05 g of
dibutyltin dilaurate and 50 g of methyl ethyl ketone to prepare a
cladding composition. This composition was coated on an aluminum
sheet and caused to cure at 150.degree. C. for 30 minutes to
provide a test sample (S-7) having a coating thickness of 20
.mu.m.
COMPARATIVE EXAMPLE 2
[0045] To 100 g of the polyoxyalkylene polyol (A-4) obtained in
Example 4 was added 67 g of hexamethylene diisocyanate and the
mixture was reacted at 90.degree. C. with stirring for 3 hours.
Then, 52 g of ethylene glycol monomethacrylate was added and the
mixture was further stirred under heating for 3 hours. Then, 6.6 g
of a photopolymerization initiator (IRGACURE 184) was added to the
mixture to give a cladding composition. This composition was coated
on an aluminum sheet and irradiated with ultraviolet light (lamp:
80 W/cm.times.1, distance from the lamp: 8 cm) to provide a test
sample (S-8) having a coating thickness of 20 .mu.m.
Measurement of Volume Resistivity
[0046] The test samples prepared in Examples 1 through 6 and
Comparative Examples 1 and 2 were allowed to stand at the varying
temperatures indicated in Table 1 for 3 days and the volume
resistivity of each sample was measured with a volume resistivity
meter (R8340/R12702A, manufactured by Advantest). The results are
shown in Table 1. TABLE-US-00001 TABLE 1 Test Volume resistivity
(.OMEGA. cm) sample 25.degree. C. 0.degree. C. Example S-1 2.5
.times. 10.sup.10 7.2 .times. 10.sup.11 S-2 3.6 .times. 10.sup.10
8.1 .times. 10.sup.11 S-3 8.5 .times. 10.sup.9 9.2 .times.
10.sup.10 S-4 6.1 .times. 10.sup.10 5.9 .times. 10.sup.11 S-5 1.3
.times. 10.sup.10 4.5 .times. 10.sup.11 S-6 5.7 .times. 10.sup.10
7.9 .times. 10.sup.11 Comparative S-7 5.2 .times. 10.sup.13 2.1
.times. 10.sup.14 Example S-8 4.1 .times. 10.sup.14 1.9 .times.
10.sup.16
[0047] It will be apparent that the cladding resin composition
according to the invention is very satisfactory in electric
conductivity.
* * * * *