Note: Descriptions are shown in the official language in which they were submitted.
6~:)136
C ,~ McPhersorl 3
,~ :
:l. Backgro~ cl o~ the Irlvention
__ _ _~
2 l. l~ield of the Invention :~
3 This lnventlon relates to a cured epoxy ;
4 polymer h-lvi.ng improved adhesive properties to a
~ : 1-
metal dep,~sit,~d on a surfaoe thereof, and more
6 particularly, to a cured cpoxy polymer resulting
7 ~rom cur-J.ng a mixture comprising (a) a diglycidyl
8 ether based upon llnoleic dimer acid~ ~b) an
9 elastomerically modlfied epoxy resin blend, ~c3
a diglycidyl ether of bi3phenol A (4,~'-isopropylidene
11 diphenol) and/or bisphenol ~ (methylenediphenol) an
12 (d) a sultable curlng agent. :
13 2. Descriptlon of the Prior Art
During the past ~ew years, a market ~or
metal~plated polymer par~s has grown rapidl~J~as
16 manufacturers have begun to appreoiate the functional~
17 appearance o~ such~parts when plated wlth brlgh~
18 metallic ~inlshes, and to take advantage o~ economies~
l9 ln cost and~weight a~forded:b~ substltuting molde~d
polymeric parts ~or metal. Furthermore, such plated -~
21 ~lnishes are not as susceptible to pittirlg and ~
22 corrosion because there is not a ~alvanic reaction
23 between a polymeric sub3trate and a plated metal.
24 Beeause polymexic materials normally~do no~t~
conduct electrlclt~, it ~9 oommon~gractlce ~o p~7vi~e~a~
28
29
:
~; :: .
~ ~ 31
; ~'.~, : :
1~6¢~1L3
conductive layer or coatiny, such as copper, by electroless
deposition so that an additional thickness of metals, par-
ticularly copper, nickel and chromium, can be electrolytically ;~ ~E
plated onto the electroless copper layer. Electroless de-
position refers to an electrochemical deposition of a metal
coating on a conductive, non-con~uctive, or semiconductive
substrate in the absence of an external electrical source.
While there are several methods of applying this metallic
coatiny by a combined use of electroless and electrolytic
procedures, it was not until quite recently that processes
were developed which can provide even minimal adhesion of the
conductive coating to the polymer. This is because overall
adhesion is governed by the bond strength between the polymer
substrate and the electroless copper layer. Even ~:ith these `
ir.lproved processes, reasonable adhesion can be obtained with
only a very few polymers, and then only when great care is -;
taken in all of the ste~s for the preparation and plating of ~ :~
the polyr.ler substrate.
Polymers extensively employed and upon which electro-
: . . .
less deposition is conducted, especially in the printed circuit
industry are epoxy polymers resulting from curing uncured di~
glycidyl ethers of bisphenol A resins produced by a condensation -~
reaction between bisphenôl A and epichlorohydrin. The conden-
sation reaction products or epoxy resins have a general structure
0\ CEI OH CH
2 2 E O ~-c~_OcH2 cE~_ cH2 _ l _ o ~_ c~
3 3 J `;
f O
~ 0 C~ CH/\ ~
~,
~:;
.
36
where n is the number of repeated units in the resin chain.
The varying types of these epoxy resins are described in
terms of their viscosity or softening point, epoxide
equivalent weight and hydroxyl content. The epoxide
equivalent weigh-t is defined as the number of grams of
resin containing one gram equivalent of epoxide. The epoxide
equivalent weight is determinative of the number of repeated
units in the epoxy resin chain. The hydroxyl content is
defined as the number of equivalents of hydroxyl groups
contained in 100 grams of resin.
One of the valuable properties of epoxy ~;
resins, i.e., diglycidyl ethers of bisphenol A and variants
or modifications thereof, is their ability to transform
readily from a liquid or viscous state to tough, hard
thermoset solids, i.e., transform from a linear structure to
a network crosslinked in three dimensions. This hardening
is accomplished by the addition of a chemically active
reagent known as a curing agent. Some curing agents promote - `
curing by catalytic action, others participate directly in
` 20 the curing reaction and are absorbed into the resin chain.
The surface of a cured or crosslinked epoxy
article is hydrophobic and is therefore not wet by liquids
havin~ a high surface tension. Since electroless
de~ositions usually employ aqueous sensitizing and "
activating solutions having metal ions therein, the surface
will not be wet thereby. Since the sensitizing and `
activating solutions will not wet the surface, the -
catalytic species are not absorbed onto the surface and
subsequent deposition of the metal ions cannot proceed.
In the present state of the art, various
methods are available for rendering the surface of a polymer
:~
-3- ~
- - :.~ , ,. ~ , ,
6~3~36 ; ~
or a plastic material hydrophilic. One method in common
practice in plating plastic materials entails mechanical -
roughening of the surface of the plastic. Initially, this ;
surface roughening is accomplished by some form of mechanical -
deglazing, such as scrubbing with an abrasive slurry, wet
, .
tumbling, dry rolling or abrasive (sand) blasting. However,
this prior art method gives an adhesion of up to 3 lbs./
in. at 25C for a copper pattern on a cured polymer based
, .
upon the diglycidyl ether of bisphenol A. This adhesion
is unsatisfactory for printed circuit boards having a copper :~
pattern thereon. It has been empirically established ;~
that a minimum peel strength of about 5 lbs./in., at a 90
; ~ :" . ~ ,
peel and a peel rate of 2 in./min. at 25C is required
,, ~ , .
to prevent a metal coating from blistering or peeling `~
from a plastic surface during variations in temperature
and to allow for various processing steps usually employed
in generating the copper pattern. The adhesion requirements
for printed circuit boards is therefore at least 5 lbs./in.
at a 90 peel and a peel rate of 2 in./min. at 25C
(for a copper thickness of 1.4 mil).
In addition, this mechanical deglazing process
,: .
is costly in that many parts have to be finished by
hand and, in the case of relatively small parts, or parts
with complex contours, it is very difficult to abrade the
surface uniformly by conventional means. Of greatest
disadvantage, however, is in forming printed circuits,
utilizing a photoimaging process, such as the photoselective
metal deposition process revealed in U.S. Patent No.
3,562,005, assigned to the assignee hereon. The `
photoimaging process inherently requires a high pattern
,~ "~,
resolution. This resolution is limited by the topography of
::
,'"; :: '
,.
'.:
'." " " .' , ' ' ' ' ', ' . . ' . ' ' ", ,' ' ' ' ' ` ;;., ' ' ' ' ,, , "' ~ , ~.~1, . . .
- `` 16)6~)~36 ~: the surface on which the pattern is generated. When
mechanical deglazing ls employed, e.g., by sand blasting,
the resolution of the pattern suffers because of the
mechanically roughened surface.
; In more recent years, chemical cleglazing or
etchir.g techniques were developed for various plastics using
strong acidic solutions. U.S. Patent No. 3,437,507 reveals
a chromic acid treatmen-t of plastics, such as an acrylonitrile~
batadiene-styrene (A-B-S) and an amine cured diglycidyl
ether of bisphenol A epoxy, to improve the adherence of
an electroless deposit to the surface thereof. Again,
as indicated above, a minimum adhesion value of 5 lbs./in. `
; has to be met for printed circuit boards. A cured
diglycidyl ether of bisphenol A epoxy polymer treated with -;
chromic acid gives adhesion values of about 3 lbs./in. for
metallic patterns deposited thereon.
Another method, generally employed for plastics,
such as A-B-S, comprises treating the plastic with an ~'
organic solvent thereof. U.S. Patent No. 3,425,946
reveals-such a method with A-B-S plastic. However, what ~
solvents are effective depend on the plastic employed and is
therefore empirical in nature. Organic s~lvent pretreatment
~, .
alone is ineffective in raising the adherence of metallic
patterns to cured epoxies such as the epoxy polymers
resulting from curing the diglycidyl ether of bisphenol A.
A cured diglycidyl ether of bisphenol A epoxy treated in ; ~ -
this fashion exhibits an adhesion of about 3 lbs./in.,
whereas as stated above, 5 lbs./in. is the minimum amount
desired for printed circuit boards (at 25C~
There has not heretofore been electroless
metallization of a virgin epoxy, i.e., an as-cured epoxy
~
'
~:
60~3~i ;
without pretreat~ent of any surface thereof with solvents,
etchants, abrasives, etc., to render such surface hydrophilic.
A cured epoxy surface which gives improved adherence
with respect to an electroless metal deposited thereon, without
pretreatment thereof (etching, solvation, abrading, etc.), is ~ ;~
, ~
therefore needed and is an object of this invention.
Sum~lary of the Invention ~;
Broadly stated, this invention relates to a cured
epoxy polymer having improved adhesive properties to a metal
deposited on a surface thereof and more particularly, to a
cured epoxy polymer resulting from curing a mixture comprising
(a) a diglycidyl ether based upon linoleic dimer acid, (b) an
elastomerically modified epoxy resin ~lend, (c) a diglycidyl ~;
ether of bisphenol A (4,4'-isopropylidenediphenol) and/or
bisphenol F (methylenediphenol) and (d) a suitable curiny agent.
ore specifically, according to the invention there
is provided a cured epoxy polyrner having improved adhesive ;~
properties comprising the reaction product of a mixture com~
.
prising: (1) a resin component comprising, (a) about 25 to -
20 about 95 parts by weight per 100 parts by weight of said resin
component of a diglycidyl ether based upon linoleic dimer acid
selected from the group consisting of (al) an adduct of two
moles of the diglycidyl ether of bisphenol A and one mole of
linoleic ~imer acid having a structural formula of
H2C-CH-CH -0 ~ CH3 -0-CH2-CH-CE~2-o
0 0 OH CH~ 0
C C_o-cH2-cH-c~2-o~ c-~-ocH2-cH-cH2 ~ .... . .
( ~ 7 (/~2)7 3
_cH=cH_~cH2~_cH3
(C~2)5
C~3
; t
~ - 6 ~
: .. ~ . : - . .. . ~ . - ~ .
6~13~
and an epoxide equivalent weight of 650 to 750, Ib1) a digly~
cidyl ether of linoleic dimer acid having a structural formula
of
/0 o o /o\ ,,
H2c_cEl_c~2_o_c C-0-C~2-CH-CH2
,-, .. . .
(CI12)7 ~CH2)7
H2-CH=CH-(CH2)~ CH3
(,CH2)5
3' : `
and an epoxide equivalent weight of 400 to 420, and ~cl) a .
mixture thereof; (b) about 5 to about 50 parts by ~7eight per
100 parts by wei~ht of the resin component of an elastomerically :
modified epoxy resin blend comprising the reacti.on product of ,
~ ., .
about ~0 weight percent of a carboxyl terminated acrylonitrile/
butadiene random copolymer having a structural formula of
CH3 C~1
HOOC-CH2CH2C ~ (CH2CH=CHCH2)5C~12CH ~ C-C~12CH2C~OH,
CN CN CN
containing 2.37 percent carboxyl groups, 18 to 19 percent bound
acrylonitrile and having a number average molecular weight of :.
3200, cor.lbined with about 60 weight percent of a diglycidyl
ether selecte~ from the group consisting of a diglycidyl ether
of bisphenol A having an epoxide equivalent weight of 180 to
195 and a diglycidyl ether of bisphenol F having an epoxide
equivalent weight of 152 to 167; and (c) a remainder of a di-
glycidyl ether selected from the group consisting of a diglycLdyl
ether of bisphenol A, a diglycidyl ether of bisphenol F or a
mixture thereof; and ~2) a curing agent selected from ~a)
acid anhy~ride present in an amount ranging from about 16 to :;~
about 60 parts ky weight per 100 parts by weight of the resin
~.
component, (b) a polyamine present in an e~ual role-to-mole
_ 7 _
i, h
';' ' ~ '. ~' , : ` ` ' ;; , ' " : , .', ,, ' ` ' .: ' ' ' ` '
6~ 3~i
ratio ~ith the resin component, (c) a mixture comprising said
~olya~line in (b) above co~ined with at leas-t 5 parts by weight
per 100 parts by weight of the resin component of an acid :: :
Ir~J ~f J~ On~ : .:
anhydride, (d) a n:ixture comprising said~acid anhydride in (a)
above combined with up to about 30 parts by weigllt per 100
parts by weight of the resin component of a carbo~ylic acid
selected from the group consisting of dicarboxylic acid having
a structural formula of
O '
.. . . .
(HO--C) 2R'', where R'' is an organic radical selected 'rom
10 CH2 (C~I2) 5cH2 ~ CH2 (C 2) 6 (Cl 2) 6 2 ~ ~ :
H 2 CH= CE~ ( C~12 ) ~ C~13
( CH2 ) 5CH3
,CH 3 ,C~I 3
2 2 , ~ 2CH CHCH2) 5-CH2-CH--3~-CH CH a d
CN CN CN . ~ :
CH CH 3
CH2CH2C~ (C~2CH=CHCH2 ) 5CH2CH~ CH CH2 ) ,C CH2 CH2;
CN CN COOH CN
a trimmer acid having a stocchiometry of C54H9606, and a mixture
thereof, and (e) a mixture of the foregoing.
Description of the Drawing : :
The present invention will be more readily understood
by reference to the drawing taken in conjunction t~,ith the .
detailed description, wherein the Figure is a
-'
- ~,~ .- ~ . - .
136 ; ~ ~
cross-sectional view of a laminar body of the invention ~;
comprising a cured epoxy-coated subs-trate plated with an
electroless metal deposit.
Detailed_Description
The present invention is described primarily ` ~ ;
in terms of an adherent copper deposit, deposited from an
electroless plating bath, upon a cured epo~y having improved
adhesive properties. However, it will be understood that ;~-
such description is exemplary only and is for purposes of
exposition and not for purposes of limitation. It will be
readily appreciated that the inventive concept described is
equally applicable to applying to the cured epoxy other
conventional species which may be utilized in cementing,
printing and metallizing the epoxy. Again, it is, of
course, to be understood that by a "cured epoxy" is meant
the product resulting from curing a curable mixture comprising
a resin component of (a) a diglycidyl ether based upon ;~
linoleic dimer acid, (b) an elastomerically modified
epoxy resin blend and (c) a diglycidyl ether of bisphenol A
and/or bisphenol F, cured with a suitable curing agent
component selected from an acid anhydride, a polyamine, a ~ ;
mixture of an acid anhydride and a polyamine, and a mixture
of an acid anhydride and a suitable carboxylic acid.
A suitable diglycidyl ether based upon
linoleic dimer acid is the adduct of two moles of the
diglycidyl ether of bisphenol A and one mole of linoleic
dimer acid (ratio of 2:1) having the structural formula ;
~",
_g_ ' :
' ~
'':
60136
0 CH 3 OH
(1) ~12C-CH-C~12-0~C~ 0-cEl2-c~I-`cH2-o~) .j
"~--C C-o-cH2-cE~-c~l2- 0~--C~ G CH2 2
(CH2)7 (CH2)7 C 3 j~
~C~2-Cll=CEl- (C:M2) ~--C~13 `;
2 5 3
These uncured modified diglycidyl ethers are described in terms
of their epoxide equivalent weight. The epoxide equivalent
,. ~ . ~ .
weight is defined as the number of grams of resin containins
one gram equivalent of epoxide. The above-described linoleic
aimer ester modified diglycidyl ether of bisphenol A employed
has an epoxi~e equivalent weight of 650 to 750.
A second suitable diglycidyl ether of linoleic
dimer acid is one haviny a general structural formula
O O O O .".' '
\ " " / \ , ~ ~
(2) H2C-CIl-CH2-0-C C-0-CH2-CH-cH2
2)7 (OEi2)7
\ ~ CH2-CH=CH-(CH2)~ C~13
(~H2)5-CH3
and an epo~ide equivalent weight of 400 to 420. ;~
The concentration of the above~described suitable
diglycidyl ether based upon linoleic dimer acid resins in the
resin component ranges from a minimum of about 0 parts by
weight per 100 parts by weight of the total resin component
(to be cured) to a ma~:imum representing the entire resin
component, i.e., lO0 parts by weight per lO0 parts by weight
of the resin. A preferred concentration ranges from about 25
to about 95 parts by weight per lO0 parts by weight of the total
resin cor.~ponent.
- 1 0 - ' '
'.~` ' .
1~60~36
Combined with the diglycidyl ether based upon linoleic ~ ;~
dimer acid, when of course the resin component to be cured
cor~lprises less than 100 parts by weight of the diglycidyl
ether based upon linoleic dimer acid, is a suitable elasto~
merically modified epoxy resin blend. ~ suitable elastomerically
modified epoxy resin blend comprises the react.ion product of
about 40 weight percent of a carboxyl terminated acrylonitrile/
butadiene random copolymer having a structural formula of
,CH3 , 3 ;~
2 2, ~ CH2C~I=CHCH-2~5~H2 CII~o c- c~l C~l COOH;
CN CN CN .
containing 2.37 percent carboxyl groups' 18 to 19 percent bound
acrylonitrile, having a number average molecular weight of 3200
and a viscosity of 110,000 cps at 27C combined ~;ith about 60
weight percent of a dlglycidyl ether selected from (1) bisphenol
A, having a structural formula ~ .
0 ~ CH OH
H2C-CH-C~lz ~ o ~ C ~ -OCH2CH CH2 ~n
~--O~C~OCH2CH-CH2,
tJhere n is the number of repeated units in the resin chain, and
having an epo~ide equivalent weight of 180 to 195 and (2)
bisphenol F, having a structural formula of
H2C_cH_oH2~o_~--C~2~_oC~12cH_cH2~o_~~CH2~) ~ ~
/0\
O-CH2CH-CH2 .
where n is the number of repeated units in the resin chain, and
,: ,~, .
.. . . .
l.
havlng an e~oxide equivalent ~eiyht o~ 152 to 167.
The ~lglycidyl ether (60 ~elght percen-t~ of bisphenol
A or blsphenol F is typically reacted with the carboxyl ter-
minated acrylonitrlle/butadiene random copolymer (40 weight
percent) at 300F for 30 m.inutes to yield a desired reaction
product or elastomerically Mo~ified epoxy resin blend. lhe
desired reaction product or elastomerically modified epoxy
resin blend comprises a mixture of the diglycidyl ether of ~ ~ :
bisphenol ~ or bisphenyl F and the adduct of -t~o moles of the
diglycidyl ether of hisphenol A or bisphenol F and one mole
of the carboxyl terminated acrylonitrile/butadiene copolyrner
which is believed to have the following structural formula .
0 ~ OH 0 CH :
H2/C-C~I-C~I2-0 ~ -C ~ -OCH2CH C~I2-OC-CH2CH2C ~ CH2CH=CHCH
R CN
. .;
tCH3 0 OH R 0
2 ,H ~ oC ~H2CH2-c-ocH2cH-cH2-o ~ -C ~ 2 2'
CN CN R
where R is a radical selected from H and CH3.
~hen the diglycidyl ether of bisphenol ~ is employed
.. . .
as the reactant, the resultant desired reaction blend or mixture
has an epoxide equivalent weight of 335 to 355, a viscosity of
Y-Z (Gardner-Holdt, 80% N.V. in methyl cellosolve [methoxy :
ethanol~), and an acid value of less than 0.2 (number of milli-
20 grams of KOH neutralized per one gram of the reaction resin :~
blend). ~-~hen the diglycidyl ether of bisphenol F is ernployed ~ ~
as the reactant, the resultant desired reaction blen~ or ~:.
mixture has an epoxide equivalent weight of 285 to 305, a .;~ :
viscosity of X-Y `~
..,; :,:`
'`.' ' ~:
', '. "
: ,: '
: ~ 12 -
. . . -
106~36 :
(Gardner-Holdt, 80% N.V. in methyl cellosolve), and an acid
value of less than 0.2 (milligrams of KOH neutralized per ~;~
one gram of the reaction resin blend). ,
The concentration of the above-described
elastomerically modified epoxy resin blend ranges from a
maximum of about 50 parts by weight per 100 parts by weight
of the resin component down to zero (where for example the
resin component comprises essentially all of the diglycidyl
ether based upon linoleic dimer acid). A preferred
concentration range however ranges from about 5 parts to -~
about 50 parts by weight per 100 parts by weight of the
resin component.
The resin component may also comprise a remainder -
o~ a suitable diglycidyl ether selected from a diglycidyl
ether of bisphenol A, a diglycidyl ether of bisphenal F or
a mixture of the two. Again, it is, of course, understood
that such a remainder is dependent upon the amounts of `
the other epoxy-group containing materials of the resin
component. The diglycidyl ethers of bisphenol A are
described in terms of their viscosity or softening point, ;~
epoxide equivalent weight and hydroxyl content. Again,
the epoxide equivalent weight is defined as the number
of grams of resin containing one gram equivalent of ~ `
epoxide. The hydroxyl content is defined as the number of
equivalents of hydroxyl groups contained in 100 grams of `~
resin.
Some typical suitable diglycidyl ethers of
bisphenol A resins are those having an epoxide equivalent
weight of 170 to about 4000. Some typical examples of these
epoxy resins are (1) DER ~31 which is a trademark product `
of Dow Chemical Company and which is an epoxy resin having
~ '
~ -13-
, .
~L~)60~3~;
an epoxide equivalent ~eiyht of 182 to 190 and a viscosity of
10,000 to 16,000 cps; (2) Epon ~ 836 which is a trademark
product of Shell Chemical Company and which is an epo~y resin
having an epoxide equivalent weight of 280 to 350, a softening
point of 40 to 45C and a hydroxyl content of 0.21; (3~ Epon ~ ~
1001 which is a trademar~ product of Shell Chemical Company ;~ -
and ~hich is an epoxy resin having an epoxide equivalent weight
of 450 to 550, a softening point of 65 to 74C and an hydro~yl
content of 0.28; (4) Araldite ~ 6097 which is a trademark :
product of Cioa-Geigy Corporation and which is an epoxy resin
having an epoxide equivalent weight of 2,000 to 2,500 and a `~
softening point of 125 to 135C; t5) Epon C) 1009 which is a
: traaemark product of Shell Chemical Company and which is an
epoxy resin having an epoxide equivalent ~7eiyht of 2,500 to
4,000 and a softening point of 1~5 to 155C.
Some typical suitable epoxy resins incorporating :
tetra~roll;obisphenol A (3,3',5,5'-tetrabromo-4,4'~isopropylidene-
diphenol) to impart fire retardancy to the cured composite are
the diglycidyl ethers of tetrabromobisphenol A having a
20 structural formula ~ :
0 Br CH3 Br 0\ :
(3) CH2-CH-CH2-0 ~ C ~ 0 C~2 2' ;~
Br CH3 r
and epoxy resins containing both bisphenol A and tetrakron~.o- ;
bisphenol A having a structural formula ... - .
f
2 C CH2 tO~--C~--O--CH2- CH- C112~- ~
~ CH3 /0\ ~ .
o ~ -C ~ 2 2' '!..
3 `
, c -- 1 ~
'' '
:. , . . . : . . -
~ ~ :
60~3~
where n is the number of repeated units in the resin chain
and X is either bromine or hydrogen depending upon the
method of manufacture of the epoxy resin. Some typical
- suitable diglycidyl ethers of tetrabromobisphenol A resins
are (1) DER ~ 542 which is a trademark product of Dow
Chemical Company and which is an epoxy resin havlng an
epoxide equivalent weight of 325 to 375, a softening point
of 45 to 55C and a bromine content of 44-48% by weight and -~
l2) Epi-Rez 3 163 which is a trademark product of Celanese
Corporation and which is an epoxy resin having an epoxide
10equivalent weight of 350 to 450 and a bromine content of 50~ -~
by weight. Typical examples of suitable epoxy resins
containing both bisphenol A and tetrabomobisphenol A are ,`
(1) Epon~ 1045 which is a trademark product of Shell Chemical
Company and which is an epoxy resin having an epoxide
equivalent weight of 450 to 500 and a bromine content of
19% by weight and (2) Araldite~ 8011 which is a trademark `
product of Ciba-Geigy Corporation and which is an epoxy
, ::
resin having an epoxide equivalent weight of 455 to
500 and a bromine content of 19-23% by weight.
The diglycidyl ethers of bisphenol F are described
in terms of their epoxide equivalent weight. Some typical -
suitable diglycidyl ethers of bisphenol F resins are
those having an epoxide equivalent weight of 165 to 180. ;
The resin component is then combined with a
curing agent component to form the curable mixture (reaction --~
mixture). A curing agent is one selected from (a) a -
suitable acid anhydride, (b) a suitable polyaminer (c) a ~;
mixture of the acid anhydride and the polyamine, (d) a :~
mixture of the acid anhydride and a suitable carboxylic acid
and (e) mixtures of the foregoing.
; ~ '.' ':,
-15- -~
1~)60136
Typical suitable anhydrides are chlorendic
anhydride, the maleic anhydride adduct of
methylcyclopentadiene [a light yellow semiviscous liquid
with a viscosity of 138.4 cps. at 25C (available
commercially as "Nadic Methyl Anhydride")] havin~ a ; ;~
structural formula
H3~>
phthalic anhydride, citraconic anhydride, glutaric ;~
anhydride, maleic anhydride, and mixtures thereof. Other .
typical anhydrides which may be employed are described in .
U.S. Patent No. 3,329,652.
The total concentration of the uncombined
acid anhydride curing agent ranges from a minimum of about .. :
16 parts by weight to about 60 parts by weight per 100 parts : ;~
by weight of the resin component. An anhydride to epoxide `~
molar ratio of 0.6 to 0.9 yields the optimum adhesive
properties of the cured polymer. ~ .
Typical suitable polyamines include dicyandiamide,
metaphenylenediamine, hexamethylenediamine, triethylenetetra
amine, polyoxypropylenediamine having a structural formula of
(6) CIH3 ,3
(H2NCH-cH2-[ocH2cH ~nNH2, .~ ;
where n is about 2), and -
polyoxypropylenetriamine havln~ a structural formula of
-.
~,
-16-
'~ :
, :. :; :.: , . . . . -. : ~ : . , ~ : ;:
L36 `~
(7) C~l3 ~ ~
c~2-LCll2cH 3X NH2
~ C~13 ~ ~
(~12C-CH2 C-CH2- LC~I2CH 1yNH2
¦ 3
CH2-~OCH2CH-~z NH2
where x ~ y + z = 5.3).
The polyamine curing agent i5 typically
combined to give equimolar concentrations of amine hydrogen
and epoxide. It has been found that a mixture of the ~;~
polyamine and a suitable acid anhydride such as glutaric
anhydride, maleic anhydride, citraconic anhydride, etc.,
can also be employed where the acid anhydride is present ~ ~
in the mixture in an amount ranging up to about 10 parts -
by weight per 100 parts by weight of the resin component.
Typical suitable carboxylic acids which may
be combined with the acid anhydride curing agent are
linoleic dimer acid having a structural formula of
~ .
(8) 0
(HO~C) C-OH),
CH2 ~ 2)7
H2CH=CH(CH2)4CH3
~ _ ~ (CH2)5C~3
linoleic trimer acid having a stoichiometry of C54H9606, an
acid value of 145 to 185 and an average molecular weight of
about 810, aza~eic acid having a structural formula of
g ) O O ,,
(HOC-(CH2)7-C-OH),
and a carboxyl terminated acrylonitrile/butadiene random ~
copolymer selected from one having a structural formula of ~ -
,
17
`'~
6~)~36
(10) '~
CH3 CH3 ;~ ~;
Hooc_cH2CH2C --CH2CH=CHcH2--5CH2CH 10 , 2 2
CN CN CN
containing 2.37 percent carboxyl groups, 18 to 19 percent `
bound acrylonitrile, having a number average molecular
weight of about 3200 and a viscosity of 110,000 cps at 27C;
and one having a structural formula o~
(11 )
,CH3 CH3
2 2, {~ 2CH CHC~2-5CH2CH~lo (cHcH2)c-cH2cH2cooH ~ ~;
CN CN COOH CN ;;~
containing 2.93 percent carboxyl groups, 18 to 19 percent
bound acrylonitrile, having a number average molecular `~
weight of about 3400 and a viscosity of 125,000 cps at 27C. !~1
The carboxylic acid concentration present in an acid
anhydride-carboxylic acid curing agent mixture ranges up to
about 20 parts by weight per 100 parts by weight of the
resin component combined with about 20 to about 60 parts by -;
weight per 100 parts by weight of the resin component of the `
acid anhydride. ~ -
It is, of course, to be understood that the
selecte.d curing agent can be combined with other type curing
agents or accelerators therefor, e.g., an amine such as
benzyldimethylamine. It is also to be understood that
conventional filler materials, such as aluminum oxide,
silicon dioxide, titanium dioxide and flame retardant `
additives such as antimony trioxide may also be added to the
resultant resin-curing agent reaction mixture.
The mixture of epoxy resin and curing agent
may then be heated to attain homogenization, complete
liquification and initiate a partial cure, e.g., typically at
-18-
~" .. - .. , ., . . . .. . , . , . . ., :
~-,.,;: - : . , . '.
::: . . ..
6~3~ ~
50-lQ0C for 5 to 60 minutes. It is to be noted that, when ~;
physically expedient to do so, the mixture may be used
without a pre-cure heat treatment. Also, alternatively, the
reaction mixture may be dissolved in a suitable solvent, ~;
e.g., acetone.
Referring to the Figure, a sui-table substrate
or base 21 is selected. A suitable substrate or base 21
may comprise any material which is compatible with the ;
epoxy resin with which it is destined to be coated and ~-
which resin is destined to be cured. For printed circuit ~-
manufacture, the substrate 21 may be of a rigid material,
e.g., glass, metal, etc., or of a flexible material, e.g., a
polymer or plastic, e.g., a polyester. Applied to a surface
22 of the substrate 21 is the curable mix-ture comprising the
resin component, the curing agent component and any solvents, ;
fillers or additives. The mixture may be applied to the
surface 22 by any conventional means, e.g., spraying, ;~-
dipping, spinning, etc., whereby a coat or layer 23 thereof
forms. The layer 23 may be of any desired thickness,
typically it may range from 0.5 to 20 mils thick.
The coated substrate 21 is then heated under
conditions of time and temperature, e.g., typically ranging ~;
from 5 to 60 minutes at 140-170C, whereby a fully cured
epoxy polymer results. By a full cure one means that the
epoxy groups originally present have been consumed during
the curing reaction and the degree of cross-linking provides
optimum physical properties for the desired application.
For the desired time and temperature relations ascribed to
above infrared spectroscopy shows that the anhydride and
epoxy groups have been consumed. In addition, the epoxy
polymer no longer flows when submi-tted to a heat and
pressure cycle.
-19- `;
., . ' ' !
':
.'' ' ~" ' ' , ' ' ~ '
~O~ L3~
It is, of course, to be understood that the ~.
time and temperature curing parameters are interdependent -~
and that variations in the temperature will require
variations in the time whereby optimum results will be
attained. In this regard, the various cur:ing parameters and i ~;~
~ -,, ,
their independency are well known in the a;rt, and their i ;
interaction between one another is also we:ll known or can be . .
easily ascertained experimentally by one skilled in the art
in the light of the subject invention disclosed herein. ;`~:
A suitable species is then deposited on a .
surface 24 of the cured epoxy layer or coat 23. A suitable
species may be any of a multitude of materials well known in
the art which can be deposited upon a cured epoxy surface
and comprises in part conventional aqueous or organic based
paints, lacquers, inks and adhesives, aqueous or non-aqueous ;
solutions of inorganic salts, aqueous or non-aqueous ~ .
electroless metal deposition solutions and the metal
deposits resulting therefrom, metals, etc. The suitable
species may be deposited or applied to the cured epoxy
surface 24 by any standard means known in the art including
dipping, brushing, spray coating, spin coating, vapor i.
depositing, electroless depositing with or without
electrodepositing, sputtering, etc~
It is to be noted and stressed at this point
that unlike prior epoxy formulations and methods of ;~
metallization thereof, the virgin epoxy disclosed in this
invention, i.e~, the cured epoxy which results (which~
i.ncludes aged material and/or reconstituted from scrap
material), does not have to be pretreated (etched, solvated, ; ;
sand blasted, etc~) -to be rendered hydrophilic to ach:ieve
adherent electroless metallization (as well as adherent
-20-
~.
---`` 10~;0~36 ~:
electrodeposited metallization) to a surface thereof. This
is a surprising and unexpected property of the epoxy
disclosed herein and the method employed in its metallization.
The selected species-deposited, cured epoxy
surface 24 is then thermally aged or post baked for a period
of time sufficient to insure adequate adhesion of the `~
selected species to the cured epoxy surface, e.gO, an -
adequate adhesion typically being represented by a metal
deposit (electroless and electro) evidencing a peel strength
of at least 5 lbs./linear in. at 25C. The thermal aging
typically may be as low as a temperature of 120C for 10
minutes or as high as 180C for one hour. ~gain, it is to ~ ~
be understood and stressed that the above temperature and ;
time parameters are all interdependent and that variations `~
in temperature will produce variations in the other
parameters whereby optimum results will be attained. In
this regard, the time-temperature adhesion parameters can `~
be easily ascertained experimentally by one skilled in the
art in view of the subject invention disclosed herein.
Where the selected species is an
electrolessly deposited metal, a standard electroless -
technique may be employed. Again, it is to be pointed out
that the cured epoxy surface 24 is a virgin surface in that
it has not been etched, roughened, solvated, swell-etched,
etc., to render the surface more receptive to electroless `
plating sensitizing, activating and plating solutions, such ;~
an expedient being unnecessary. A typical electroless ~ `
.;. , .
technique which is illustrative only and not restrictive is
as follows. The cured epoxy surface 24 is thoroughly rinsed
, :
-21- ~
` ~'' ',
'` '' ~
'; ' ., ', ' ,,'~ ~ . .~.' ' '.','; ' ' ' . . ' ' ' ' , '
~6~L36 :~
with water or any other suitable cleaning agent. Proper ;~
rinsing is essential in order to remove essentially all
contamination, such as contaminating particles, etc., so as
- not to contaminate a sensitizing, an activating and an
electroless plating solution to ~hich the epoxy surface 24
is destined to be subjected. Contamination, particularly of
the plating bath, is undesirable because the stability of ;;
such plating baths is frequently adversely affected by such ~
a condition. ~ ~ `
After rinsing, the cured epoxy surface 24 is `~
then sensitized. Sensitization consists of depositing or
absorbing on the epoxy surface 24 a sensitizing species,
e.g., Sn 2 ions, which is readily oxidized. Conventionally, ;
the cleaned surface 24 is dipped into a standard sensitizing
solution, e.g., aqueous stannous chloride with a supporting
medium such as HCl, ethanol, ethanol and caustic, or ethanol
and hydroquinone. It is to be understood that the
~ensitizing solutions and the conditions and procedures of ~ "
sensitizing are well known in the art and will not be
20 elaborated herein. Such sensitizers and procedures may be
found, in part, in Metallic Coating of Plastics, William
~: .
; Goldie, Electrochemical Publications, 1968.
After sensitizing, the sensitized epoxy
; surface 24 is rinsed, then activated. It is to be noted
that it is important that the sensitized surface 2~ be ~
rinsed thoroughly in a cleaning medium, e.g., deionized ~ `
- water, after sensitizing. If such is not done, there is a
possibility that excess sensitizer on the surface will cause
reduction of an activating species, e.g., Pd+2, to which the
sensitized surface is destined to be exposed, in non-adherent
form on the surface 24. Activation relates to providing
-22~
.~ , , - ~ . . ,
~6~)~3~
" , . ~;
a deposit of a catalytic metal, e.g., Pd, over the surface
of the cured epoxy polymer, ln sufficient quan-tities to
successfully catalyze a plating reaction once the surface ~-
24 is introduced into an electroless plating bath. The
sensitized surface 24 is exposed to a solution containing -
the activating species, e.g., a noble metal ion, wherein the ; ~ -
sensitizing species is readily oxidized and the noble metal
ion, e.g., Pd+2, is reduced to the metal, e.g., Pd, which ;
in turn is deposited on the cured epoxy surface 24. The
deposited activating metal, e.g., Pd, acts as a catalyst for
localized fur-ther plating. Again, it is to be understood
that the various activating metal ions and their solutions,~
the conditions and procedures of activation are well known
in the art and will not be elaborated herein. Such ~ ;
activators and procedures may be found, in part, in Metallic
Coatinq of Plastics, previously referred to. ~;
. . .
After the activating step, the activated `
epoxy surface 24 is rinsed with deionized water and then
immersed in a standard electroless plating bath containing a
metal ion, e.g., Cu+2, destined to be reduced by the ;~
catalytic metal species, e.g., Pd. The metal ion, e.g., Cu 2, ;
is reduced by the catalytic metal, e.g., Pd, and is
electrolessly deposited on the polymeric surface 24 to form
a metallic, e.g., Cu, layer or deposit 26 (referring to the
Figure). Again, it is to be pointed out that the electroless -
baths, the electroless plating conditions and procedures
are well known in the art and will not be elaborated herein. ~`
Reference is again made to Metallic Coating of Plastics,
previously referred to, for some typical examples of
electroless baths and plating parameters. It is to be noted
that in some cases, it is possible to combine the
:~ .
-23-
-~ 136
. ~ .
sensitizing and activatlng steps ~.
into one step. The electroless metal-deposited, cured epoxy
composite is then thermally aged, e.g., at 110 to 180C for -~
10 to 60 minutes whereby an adherent electroless metal
deposit is attained. It is to be noted that the electroless
metal deposit may be subjected to a conventional
electroplating treatment whereby it is built up. In such a
situation, it is, of course, understood that there may be an
additional thermal aging or post bake or just one thermal
aging, after the final electroplating treatment.
A preferred method of electrolessly depositing
a metal on the resultant cured epoxy surface is the method
revealed in U.S. Patent No. 3,562,005, assigned to the
assignee hereof. The preferred method entails applying
a photopromoter solution to the surEace 2~ utilizin~
procedures revealed in U.S. Patent No. 3,562,005. A
photopromoter is defined as a substance which, upon being
exposed to appropriate radiation, either ta) dissipates
chemical energy already possessed thereby or (b~ stores
chemical energy not previously possessed thereby. When ;-
the substance possesses or has stored chemical energy it
is capable of promoting, other than as a catalyst, a
chemical reaction whereby it, the photopromoter, undergoes
a chemical change in performing its function (unlike a
catalyst). The resultant photopromoter-covered, cured
epoxy surface 2g may then be rinsed with deionized water
(depending on the type of photopromoter employed) and is ~-
then dried. The photopromoter-coated surface 24 is then
selectively exposed to a source of ultraviolet radiation, -
through a suitable mask, to form at least one region which
is capable of reducing a precious metal from a precious
-24-
. . - . . . .
,. ~ .
6~)136
metal salt, e.g., PdC12. The region
so capable is exposed to -the precious metal salt, e.g., `~
PdC12, whereby the precious metal salt is reduced to the
- precious me-tal, e.g., Pd, which in turn is deposited thereon.
The precious metal-deposited region is then ~`
exposed to a suitable electroless mekal plating bath, e.g.,
copper, wherein the metal, e.g, copper, is pla-ted on the
region forming an adherent metal deposit or layer 26 on the
cured epoxy surface 24. The electroless metal-deposited i;
cured epoxy surface 24 is then thermally aged or post baked, ~` `
e.g., typically at 110 to 180C for 10 to 60 minutes,
whereby an adherent electroless metal deposit 26 is ~-
attained. It is to be noted that the electroless metal
deposit may be subjected to a conventional electroplating
treatment whereby the electroless metal deposit is built up.
In such a situation, it is again to be understood that there ~ `
may be an additional thermal aging or just one thermal
aging, after the electroplating treatment.
A suitable photopromoter soluiion may be
either a positive type or a negative type as discussed in
.
U.S. Patent No. 3,562,0~5. A suitable mask, either positive
or negative, depending on whether the photopromoter is
positive or negative, is one as discussed in U.S. Patent
No. 3,562,005, and typically comprises a quartz body having
a radiation opaque pattern thereon. The ultraviolet
radiation source is a source of short wavelength radiation
(less than 3,000A, and typically about 1,800A to about "~
O ~ : -
2,900A).
EXAMPLE I
An epoxy resin-curing agent mixture (liquid)
was prepared in the following manner. One hundred fifty
: ~ `,:,
-25-
: . .... . . . .. . .
~L~6[)~36
yrams (75 parts by weisht per 100 parts by welght of the resin
component of the mixture) of a commercially,obtained epoxy
resin, the adduct of two moles of the dislycidyl etIIer of
bisphenol A (epoxide equivalent weight of 180 to 195) and one ;~
mole of linoleic dimer acid having the structural formula
O\C~I3 OII ~"
, H2C-(~CH2-o~ ~-0CH2CH-CH2-0--~ ,
C 3
H -C ~ -0~I:2CH-CH2~ , ~
C~2)7 (CH2)7 3 , ,.~ ;
;'' ':;,
~\ ~ (C~I2) -CH
and an epoxide equivalent weight of 650 to 750 was combined ' ~.:
with 50 g.rams (25 parts by weight per 100 parts by weight of :~
the resin component) of a cormercially obtained, custom-
10 synthesized elastomerically modified epoxy resin blend comprisins ,.~
the reaction product of a mixture comprising (1) 40 we~ight ~ :
percent of a carboxyl terminated acrylonitrile/butadiene random
copolymer having a structural formula of : ; :
CH3 , 3
Hooc-cH2CI~2-C ~ CH2C~I=c~lc~l2)5cH2c~l ~ oC-c'~I2cH2
C~ CN CN
containing 2.37 percent carboxyl groups, 18 to 19 percent bound
acrylonitrile, having a number average molecular weight of
3200 and a viscosity of 110,000 cps at 27C and (2) 60 weight
percent of a diglycidyl ether coMprising bisphenol ~ having an '
epoxide equivalent weight of 180 to 195. The mixture had been ~ :
20 heated at 300~ for 30 minutes to yield a reaction product or
blend having an epoxide
-- 26 -
?~ :
':
.36
., :
equivalent weight o~ 335 to 355, an acid value or number of
less than 0.2 ~illigram of KOH/gram of reaction product, and `
a viscosi-ty of Y-Z (Gardner-Holdt 80~ N.V. in methyl `~
cellosolve [methoxy ethanol]). ~ ~ -
To the resin component was added 40 grams of ; ~
, ~. , .
chlorendlc anhydride (20 parts by weight per 100 parts by
weight of the resin component) and 5 grams of phthalic
anhydride (two and one-half parts by weight per 100 parts by
weight of the resin component) to form the epoxY resin-
curlng agent mlxture. The resultant mixture was then
heated to liquifaction at 60C for 30 minutes. i -~
Referring to the Figure, a commercially obtained ;~
epoxy-glass laminate was employed as a substrate 21.
The liquified epoxy resin-curing agent mixture was applied ` ;
to a surface 22 thereof, using a conventional means,
to form an epoxy (partially cured) layer 23 thereon ~0.5 to
2 mils thick). The coated substrate 21 was then heated at
150C for 30 minutes to obtain a fully cured epoxy layer or
coat 23 as evidenced by infrared spectroscopy which revealed
a disappearance of anhydride and epoxide functional groups.
The fully cured epoxy-coated substrate 21
(virgin epoxy coated) was then sensitized by immersion in a `
conventional aqueous hydrous oxide tin sensitizer ~a 3.5
weight percent SnC12.2H20 and 1 weight percent SnC14.5H2O
aqueous solution) for one minute at 25C, activated in a .05
weight percent aqueous PdC12 solution by immersion therein
for 30 seconds, water rinsed for two minutes and then ~ ~
:',' ,:
immersed in a commercially obtained electroless copper ~-
plating bath to deposit an electroless copper layer 26 on
the epoxy layer 23. The electroless copper layer 26 was
then subjected to a conventional electroplating to obtain a
-27-
:~ , . , .- . . ,. , , ; . . . : :
.:~: . . . - ; : - : , . ,,. : - - .
36~1136 ~-
1.5 mil thick copper layer 26 and thereby form a laminar ;~
article comprising a metal (Cu) layer 26 deposited on an ~ ;
epoxy layer 23. The electroplated deposited substrate 21
was the~ heated or baked at 120C for 10 minutes. -
A peel strength measurement of the deposited
metal was undertaken at a 90 peel at a rate of two inches
per minute employing a conventional peel testing apparatus. ; ;~
The peel strength was 14.3 lbs./linear inch at 25C. At
90C the peel c.trength value was 1.1 lb~/linear inch. For ;~
printed circuit manufacture a peel strength of 5 lbs./linear
inch at 25C is adequate.
EXAMPLE II
The procedure of Example I was repeated except
that the resin component of the mixture comprised the
following:
(a) 30 grams ~30 parts by weight/100 parts ~
by weight of the resin component) of the adduct of two moles ~ ; ;
of the diglycidyl ether of bisphenol A having an epoxide
equivalent weight of 180 to 195 and one mole of linoleic ;
dimer acid (of Example I);
(b) 30 grams (30 parts by weight/100 parts
by weight of the resin component) of the reaction product or ;~
elastomerically modified epoxy resin blend resulting from ;
combining 40~ by weight carboxyl terminated butadiene/
acrylonitrile random copolymer and 60% by weight of the
. . ~ ,.:
diglycidyl ether of bisphenol A having an epoxide equivalent
weight of 180 to 195 [of Example I]; and
(c) 40 grams (40 parts by weight/100 parts
by weight of the resin component) of a brominated diglycidyl
ether of bisphenol A, commercially obtained, having an
epoxide equivalent weight of 450 and 500 and containing
...
-28-
0136 `~
18-20~ by ~eight of bromine and having the s-tructural formula
previously described and designated as structural formula (4), ~ -
above, ~ ;
C~2 - Ci~- C112--EO ~ - C ~-0 C~12 CH_ci l 2 ~ ~--C~
x CH3 _ n 3
O :: :
OCH2-CH-C'~I2' '
where n = number of repeated units and x = H or Br.
l'he resin component was combined with a curing agent
component comprising 30 grams (30 parts by weisht/100 parts by
weight of the resin component) of chlorendic anhydride and 16
grams (16 parts ~y weight/100 parts by weight of the resin
component) of an auxiliary anhydride comprising the adduct of
~: , .
methylcyclopentadiene and rlaleic anhydride having a structural ~ ;
formula designated as structural formula (5), above.
/ IH C ~ ;~
_~O ;` :
,~
The combined components of resin and curing agent
.
were not heated prior to applyins the mixture to the substrate
21. Again the epo~y resin-curing agent coated substrate was
heated at 120C for 30 minutes to attain a fully cured epoxy
as evidenced by an infrared spectrur.l which revealed the
disappearance of the anhydride and epoxide functional groups.
A post-bake of 170C for 30 minutes of the metaI-
deposited substrate 21 was undertaken.
~ '
- 29 - ~
Peel strengths of 2.6 to 3.7 lbs./linear
inch at 0C, 9 to 10 lbs./linear inch at 25C and 5 to 7
lbs./linear inch at 90C were obtained.
EXAMPLE III
The procedure of Example I was repeated
except that the resin mixture comprised:
(a) 40 grams (40 parts by weight/100 parts
by weight of the resin component) of the adduct of two moles
of the diglycidyl ether of bisphenol A having an ~poxide
equivalent weight of 180 to 195 and one mole of linoleic
dimer acid (of Example I); ~ ;
(b) 30 grams (30 parts by weight/100 parts
hy weight of the resin component) of an elastomerically ~-
modified epoxy resin blend comprising the reaction product
resulting from the reaction at 300F for 30 minutes of (1)
, .
40 weight percent of the carboxyl terminated
acrylonitrile/butadiene copolymer of Example I and (2) 60
weight percent of the diglycidyl ether comprising bisphenol
F having an epoxide equivalent weight of 152 to 167 (the
reaction product or elastomerically modified epoxy resin ,~
blend having an epoxide equivalent weight of 285 to 305,
an acid value of less than 0.2 milligrams of K~H per one
gram of the resultant reaction blend and a viscosity of X-Y
[Gardner-Holdt, 80% N.V. in methyl cellosolve]); and ~`
. .
(c) 30 grams (30 parts by weight/100 parts
by weight of the resin component) of the brominated
diglycidyl ether of bisphenol A (of Example II).
The resin mixture was combined with a mixture ~
comprising: -
; 30 (a) 20 grams (20 parts by weight/100 parts
by weight of the resin component) of chlorendic anhyclride
curing agent;
-30-
,
~; ,
~.
. . :,: : : ~ : ::
L0~0~.3~ ~ ~
(b) 10 grams (10 parts by weight/100 parts
by weight of the resin component) of the adduct of
methylcyclopentadiene and maleic anhydride lof Example II,
above] curing agent; ,;
(c) 10 grams (10 parts by weight/100 parts ;
by weight of the resin component) of citraconic anhydride -
curing agent;
(d) 1 gram of benzyldimethylamine curing agent
accelerator; and
. ::,
(e) 2 grams of antimony trioxide.
,-, : ,, ,~, .. .
The combined components were then directly
applied to the substrate 21 and fully cured at 150C for one
hour. The peel strength obtained (af-ter the post bake of ~;
the metal-deposited substrate 21 (laminate) was 8 lbs./
linear inch a-t 25C.
EXAMPLE IV ~-
The procedure of Example I was repeated except ~ ;
that the resin mixture comprised~
(a) 30 grams (28.8 parts by weight/100 parts
by weight of the resin component) of the diglycidyl
ether of linoleic dimer acid, commercially obtained, and
having the structural formula previously described and
designated as structural formula (2), above, i.e.,
/0\ 0 0 /0\ `.~ ~ -
H2C-CHCH2-0-C ,C OCH2CH CH2 ~ ~ ?~
(CH2)7 2)7
2CH CH(CH2)4CH
(CH ) CEI
2 5 3 `~
and an epoxide equivalent weight of 400 to 420; ~;~
(b) 34 grams (32.7 parts by weight/100 parts
by weight of the resin component) of the reaction product
(300 F, 30 minutes) of 40~ by weight of the carboxyl
-31-
. . ,, ,., . , . , , , ~,
~L~6~)~L36 ~
terminated butadiene/acrylonitrile copolymer and 60~ by
weight of the diglycidyl ether of blsphenol A having an
epoxide equivalent weight of 180 to 1~5 [o:E Example I]; and
(c) 40 grams (38.5 parts by weight/lOQ parts
by weight of the resin component) of the brominated :
., ~ ",
diglycidyl ether of bisphenol A (o~ Example II).
The resin mixture component was combined with a
mixture comprising~
(a) 25 grams (24 parts by weigh~/100 parts
by weight of the resin component) of chlorendic anhydricle .`
curing agent;
(b) 25 grams (24 parts by weight/100 parts ~
by weight of the resin component) of the adduct of ..
methylcyclopentadiene and maleic anhydride [of Example
II, above] curing agent; and
(c) one gram of a curing agent accelerator,
commercially obtained, having the structural formula
OH
(CH3)2NCH2 ~ 2 ( 3)2
~H
2 ( 3~2
The combined components were then directly
applied to the substrate 21 and fully cured at 150C for
30 minutes. The peel strength obtained (after the post
bake of the metal-deposited laminate) was 8 lbs./linear inch
at 25C. ~:
EXAMPLE V
The procedure of Example I was repeated except ; ~;~
that the resin component of the mixture comprised the following: :
-32-
~0~i()13~
... . .
(a) 750 grams (17 parts b~ weight per 100
parts by weight of the resin component) of the diglycidyl ~:
ether of linoleic dimer acid having the structural forrnula :
-to\ O O /o ,: -
,,H2C-CH-CH2-0-C C-O-CH2CE~-CH2l
(CH2)7 ( 2)7 :
< ~ H2cH=cH-(cH2)4 CH3
~ (CH2)5-CH3 ~
and an epoxide equivalent weight of 400 to 420; ~ :
(b) 1250 grams (28.5 parts by weight per ~
,~ , ,
100 parts by weight of the resin component) of the adduct of
two moles of the diglycidyl ether of bisphenol A having an
,:
epoxide equivalent weight of 180 to 195 and one mole of
linoleic dimer acid (of Example I); and
(c) 2400 grams (54.5 parts by weight per ~i
100 parts by weight of the resin component) of the :
brominated diglycidyl ether of bisphenol A (of Example II).
. .
The resin mixture was combined with a mixture
comprising~
(a) 1000 grams (22.7 parts by weight per 100.
parts by weight of the resin componentj of chlorendic
anhydride curing agent; ; ~.
(b) 1000 grams (22.7 parts by weight per .` :~
100 parts by weight of the resin component) of the adduct of
methylcyclopentadiene and maleic anhydride curing agent (of
Example II);
(c) 400 grams (9.1 parts by weight per 100
parts b~ w~ight of the resin component) of a carboxyl
terminated butadiene/acrylonitrile random copolymer having a
structural formula of
`: :
~33-
': , ,
`,,. ' , .
., ' '~
1~6~)~L36
,
, ......................................................... , - .
CH3 CH
l ~ _ , 3
HOOC-CH2CH2-C~ _ 2 CHCH2 5CH2CH , 10l CH2CH2C
: ,
containing 2.37 percent carboxyl groups, 18.8 percent bound
acrylonitrile, having a number average molecular weight of
3200 and a viscosity of 110,000 cps at 27C;
(d) 200 grams ~4.5 part~ by weight per 100 ~ .
parts by weight of the resin component) of a carboxyl
terminated butadiene/acrylonitrile random copolymer having a
structural ~ormula of
,CH3 3
HooC-CH CH2C {cH2cH=cHcH2-scH2cH ~ 10(CH CH2~, 2 2
CN CN COOH CN
containing 2.93 percent carboxyl groups, 18 to 19 percent
bound acrylonitrile, having a number average molecular
weight of 3400 and a viscosity of 125,000 cps at 27C;
(e) 200 grams (4.5 parts by weight per 100
:: . :
parts by weight of the resin component) of a ground mixture
comprising 70 parts by weight of antimony oxide and 30 parts
by weight of a butadiene/acrylonitrile copolymer containing
33 percent acrylonitrile and having a specific gravity of
0.98 and an average Mooney viscosity of 80; and
(f) 50 grams (1.1 parts by weight per 100
parts by weight of the resin component) of benzyldimethyl- ;~
amine. ;
The combined components were then applied to
and impregnated a glass cloth having a thickness of about 4
mils and cured at 160C for six minutes and 150C for 15
minutes to obtain a full cure. The peel strength obtalned
of the metallized composite, after a 170C bake for 30 `
minutes, was 7 to 9 lbs./linear in. a~ room temperature.
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. . , , : : ., , :
1~6~)136 ::
Example VI
:' :
The procedure of Example I was repeated
except that the resin component mixture comprised the
following~
(a) 1000 grams (50 parts by weight per 100
parts by weight of the resin component) of the adduct of two
moles of the diglycidyl ether of bisphenol A having an
epoxide equivalent weight of 180 to 198 and one mole of ::
linoleic dimer acid (of Example I); and :
(b) 1000 grams (50 parts by weight per 100
parts by weight of the resin component) of the brominated
diglycidyl ether of bisphenol A (of Example II).
The resin componen-t mixture was combined with ;;
a mixture comprising:
(a) 500 grams (25 parts by weight per 100
parts by weight of -the resin component) of the adduct of ~ :
methylcyclopentadiene and maleic anhydride (of Example II);
(b) 300 grams (15 parts by weight per 100
parts by weight of the resin component) of chlorendic
anhydride; ~ :
(c) 240 grams (12 parts by weight per 100 ~
parts by weight of the resin component) of a carboxyl `~ ;
terminated butadiene/acrylonitrile random copolymer having
a number average molecular weight of 3200, containing 2.37
percent carboxyl groups and 18 to 19 percent acrylonitrile, :
having the structural formula ~`
,CH3 1 3
Hooc-cH2-cH2-c~H2cH=cH-cH2-5cH2cH~loc-cH2cH2cooH;
CN CN CN ~; ,
(d) 200 grams (10 parts by weight per 100
parts by weight of the resin component) of the tri-carboxylic ~ :
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~.
6~)13~i ~
acid obtained from the trime~ization of linoleic acid having
- a molecular weight of approximately 810 and an acid value of
145 to 185 and a stoichiometry of C54H9606;
(e) 66 grams (3.3 parts by weight per lQ0
parts by weight of the resin component) of a paste made by
grinding mixture of 60 parts by weight of antimony oxide
and 40 parts by weight of the diglycldyl ether of bisphenol
A having an epoxide equivalent weight of 180 to 195; and
(f) 20 grams (1.0 part by weight per 100
parts by weight of the resin component) of benzyldimethylamine. ~; ;
The combined components were applied to and
impregnated a glass cloth having a thickness of about 4 mils ;
and cured at 150C for 20 minutes to give a fully cured
composite. The peel strength, obtained after a bake at 170C
for 30 minutes of the resultant copper-epoxy composite was
16 to 20 lbs./linear in. at room temperature. ;
EXAMPLE VII ~
~ ~
An epoxy resin-amine curing agent solution
was prepared in the following manner. One hundred and fifty
grams of the adduct of two moles of the diglycidyl ether of
bisphenol A having an epoxide equivalent weight of 180 to
195 and one mole of linoleic dimer acid (of Example I) was
combined with 6.2 grams of hexanediamine, 50 ml. of xylene
and 100 ml. of acetone. A 4 mil thick glass cloth
(commercially obtained) was immersed into the solution and
allowed to drain. The impregnated or coated cloth was then
fully cured at 140C for one hour. The fully cured
epoxy-glass was then metallized as described in Example I ~`
and baked at 120C for 10 minutes. A peel strength
measurement of the deposited copper metal (90C peel at two
~ ;~
:
' . : `,' :~;
3136
inches per minute) gave a value of 8 lbs./llnear in. at
room temperature.
E XAMP LE V I I I ~ ,
A commercially obtained epoxy-glass hardboard ;~
was coated, to form a layer 0.5 mil thick, with an epoxy
j ~ :
resin-curing agent solution comprising (a) 550 grams ``
of the epoxy resin comprising the adduct of two moles of the
diglycidyl ether of bisphenol A having an epoxide equivalent
weight of 180 to 195 and one mole of linoleic dimer acid (of ~ ~ -
Example I), Ib) 16.2 grams diethylenetriamine, (c) 150 ml.
of xylene and (d) 300 ml. of toluene. The coated epoxy~
glass hardboard was allowed to cure under ambient conditions
for one day. The cured board was then metallized as
described in Example I and then baked at 140C for one
hour. A peel value of 8 lbs./linear in. was obtained.
EXAMPLE IX
_
One hundred and fifty grams of the adduct of
two moles of the diglycidyl ether of bisphenol A having an
epoxide equivalent weight of 180 -to 195 and one mole of
linoleic dimer acid (of Example I) was combined with (a) 3 ;;
grams of diethylenetriamine, (b) 25 grams of a polyoxy- ~;
propylenediamine having an approximate molecular weight of
1,000 and a structural formula of `
,CH3 ,CH3
H2NCH-[CH2-OCH2CH-]nNH
where n = 15.9, (c) 50 ml. of xylene, (d) 75 ml. of
isophorene and (e) 100 ml. of acetone. A commercially `
obtained epoxy-glass hardboard was coated with the resultant ~ ;
epoxy resin-curing agent solution to form a layer 2 mil ~ ;
thick. The coated board was allowed to cure at ambient
conditions for one day and then metallized as described in
.,
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,
.
0~L3~
Example I. The copper-deposited sample was then baked at
140C for one hour. A peel strength of 12 lbs./linear in.
was obtained at room temperature.
EXAMPLE X
The procedure of Example IX was repeated except
that there was a bake at 140C for 30 minutes prior;~
to metallization and a bake after metallization of 140C for
one hour. The peel value obtaind was 8 lbs./linear ln. ~ ~
EXAMPLE XI ~.,~;.
The procedure of Example I was repeated except ~ ;
that 125 grams of the adduct of two moles of the diglycidyl
ether of bisphenol A having an epoxide equivalent weight
of 180 to 195 and one mole of linoleic dimer acid (of
Example I) was col~ined with (a) 12.2 grams of a
polyoxypropylenetriamine having an approximate molecular
wei~ht of 403, having a structural formula
CH 2 ~ CH2 CH~XNH2
CH3
~: :
CH3CH2 ( ' CH2~0CH2 CH~yNH2
I , 3
CH2-~OCH2CH-]zNH2,
where x + y + z = 5.3, and (b) 125 grams of toluene. An
epoxy-glass hardboard, commercially obtained, was coated
with the resultant solution and cured at 120C for one hour.
The fully cured board was then metallized as described in
Example I and baked at 120C for 10 minutes. The resultant
peel value was 7.5 lbs./linear in. at 25C.
,~~ EXAMPLE XII -~
The procedure of Example I was repeated
except that 75 grams of the adduct of two moles of the
. ~,. :
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: ~; . , . . : : , . -. , . '
' .,;: . ,- .:. ;, . , ,~ .
... . . . . . . . .
1~)6~36
diglycidyl ether of bisphenol A having an epoxide equivalent
weight of 180 to 195 and one mole of linoleic dimer acid (of
Example I) was combined with (a) 25 grams of a reaction
mixture (300F for 30 minutes) comprising (1) 40 parts by
weight of a carboxyl terminated butadiene/acrylonitrile -
copolymer (of Example VI) having a number average molecular
weight of 3200, and (2) 60 parts by weight of a diglycidyl
ether of bisphenol A having an epoxide equivalent weight of
180 to lq5, (b) 12 grams of a polyoxypropylenetriamine (of ~;
Example XI), and (c) 25 grams of xylene. An epoxy-glass
hardboard was coated with the resultant solution and cured
at 120C for one hour. The fully cured board was then
metallized as described in Example I and baked at 170C for
30 minutes. A peel value of 6 lbs./linear in. at 25C was
obtained.
EXAMPLE XIII ;
The procedure of Example I was repeated except
:.
that the resin component comprised:
(a) 24 grams of the reaction product (at
300F for 30 minutes) of (1) 60 weight percent of the ~`
diglycidyl ether of bisphenol A having an epoxide equivalent `~
weight of 180 to l9S and (2) 40 weight percent of a carboxyl
terminated butadiene/acrylonitrile copolymer (of Example VI)
having a number average molecular weight of 3200, and
(b) 80 grams of the diglycidyl ether of-~; ;`
bisphenol A having an epoxide equivalent weight of 180 to -
195. "~
The resin component was combined with 32
grams of polyoxypropylene triamine (of Example XI).
The combined components were then coated on
an epoxy-glass hardboard, commercially obtained, and cured
'
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, . ., : . . ~ - ' .
.: , : . . , . , . :
- 1~6~)136
at 100C for one hour. The cured board was metallized and
then baked at 170C for 30 minutes. Peel values of 8.8 to
12.5 lbs./linear in. at 25C, 7 lbs./linear in. at 0C and
3.5 lbs./linear in. at 90C were obtained.
EXAMPLE XIV
The procedure of Example XI was repeated
except tha-t the resin component comprised~
(a) 50 grams of the reac-tion product (at ~ ~ ;
300F for 30 minutes) of (1) 60 weight percent of the
diglycidyl ether of bisphenol A having an epoxide equivalent
weight of 180 to 195 and (2) 40 weight percent of the carboxyl
terminated butadiene/acrylonitrile copolymer (of Example VI)
having a number average molecular weight of 3200; and ; (b) 50 grams of the diglycidyl ether of
tetrabromo bisphenol A having an epoxide equivalent weight
of ~50 to 500 (of Example II).
The resin component was combined with 13
grams of polyoxypropylenetrlamine (of Example XI). The `
combined components were then coated on the epoxy-~lass
hardboard and cured at 120C for 30 minutes. The cured
board was metalli2ed and then baked at 170C for 30 minutes.
A peel value of 10 lbs./linear in. at 25C was obtained.
It is to be understood that the above-described
embodiments are simply illustrative of the principles of
the invention. Various other modifications and changes
may be made by those skilled in the art which will embody
the principles of the invention and fall within the spirit `~
and scope thereof.
,~ ~
.~
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