Note: Descriptions are shown in the official language in which they were submitted.
o759S5
This invention relates to a photopolymerizable composition which
displays good adhesion when applied to a support composed of copper or a
copper alloy. Application of the photopolymerizable composition to the
support may be accomplished by coating with a solution of the components
of the photopolymerizable composition and drying the resulting layer, or
by the dry transfer of a prefabricated laminate material consisting of a
photopolymerizable layer secured to a temporary flexible base.
It is known to apply, either by a wet or by a dry process, light-
sensitive layers, especially pho~oresist layers, to a permanent support of
metal, especially copper~ where the layer is then image-wise exposed and
developed and the bared areas of the support are finally modified by the
application or removal of metal, The process is used in particular for the
preparation of printed circuits, but also for the photomechanical preparation
of gravure or multi-metal printing plates obtained by image-wise etching of
copper-based supports.
In the processing of photoresist layers, especially photopoly-
merizable layers, on copper supports, the frequently unsatisfactory ad-
hesion of the layers to the supports presents a great problem This is
particularly evident when the photoresist layer is formed of very fine,
insulated particles and is then used as an etching or electroplating resist.
In this case, it may happen that the processing solutions penetrate beneath
fine portions of the layer and may even separate them from the support.
Several suggestions have been made to eliminate this drawback by
adding adhesion-improving substances. Thus, United States Patent No.
3,622,334 discloses a photopolymerizable
~'"A
' .L~ - 1
K 2343
:~075955
layer capable of a dry transfer which contains certain N-
heterocyclic compounds to improve its adhesion to metal sup-
ports.
U. S. Pat~nt No. 3,645,772, discloses a process for
improving the adhesion of a photoresist layer on copper sup-
ports, in which the support is coated, before application of
the photoresist layer, with a thin, intermediate layer com-
prising an organic nitrogen compound which also may contain
mercapto groups.
German Offenlegungsschrift No. 2,028,773, discloses
mercapto compounds as adhesion-imparting agents between photo-
hardenable copying layers and copper supports. The adhesion-
imparting agents may be present either in the copying layer
or as a separate intermediate layer. Heteroc~clic compounds
` containing mercapto groups, e.g. marcapto benzthiazole, but
- also the mercapto acetic acid 2-naphthyl amide, are described
- as particularly useful adhesion-imparting-agents. The latter
compound is named, as the only representative of its class,
on page 6 of the Germ3~ Offenlegungsschrift. No details are
given of its effect and application.
The German Offenlegungsschrift discloses only the
application of layers from a solution, especially of photo-
hardenable diazo layers. Now it has been found that adhesion
problems occur in particular in the dry transfer process,
because layers applied by this process do not seem to have
the degree of adhesion to the supp~rt attained by layers ap-
plied from a solution. Further, it was found that photopoly-
merizable layers have particular adhesion problems after expo-
-2-
1~75955
sure, because they are always ~ore brittle in the polymerized, hardened
state than they are in the unexposed state, The increased brittleness may
result in an easier undercutting by etching or electroplating solutions and
- may even cause portions of the layers to break away, On the other hand,
photo-resist layers intended for a dry transfer process, also designated as
dry resis~ layers, must not be too soft in the unexposed state, because other-
wise they would display an undesired cold flow during storage, especially in
the case of relatively thick layers.
Both when used as components of a layer and as a separate inter-
- 10 mediate layer, the hitherto known adhesion-imparting agents are not effective
enough to anchor photopolymerizable layers so safely to copper supports that
the photo-resist produced there~rom is sufficiently resistant to corrosive
etching and electroplating baths.
It is an object of the present invention to provide new photo-
polymerizable laminate material containing adhesion-imparting substances for
the purpose described, which are superior in their effect to known adhesion-
imparting agents.
According to one aspect of the invention there is provided in a
photopolymerizable laminate material comprising a base and a thermoplastic
photopolymerizable copying layer, said layer comprising a) a thermoplastic
polymeric binder, b) a photopolymerizable compound which boils at a tempera-
ture of at least 100C and which contains at least one terminal, ethylenically
unsaturated group, and c) a photoinitiator, activatable by actinic radiation,
the improvement comprising including an adhesion-imparting substance evenly
- distributed in the photopolymerizable copying layer or applied as a separate
layer on that surface of said copying layer remote from said base, said ad-
hesion-imparting substance having the formula
R
H
[ HS - (CH2)n - CO - N - ~ - R2
~ 3 ~
. ,
'~ .
S95S
in which
; m is 1 or 2,
n is 1 or 2,
Rl is H, halogen, or an alkyl or alkoxy group, and
R2 is halogen or an alkyl or alkoxy group.
;
~ ~ -3a-
` 107~i9SS
According to a further aspect of the present invention there is
provided a process for preparing a copper or copper alloy support bearing
an adherent photopolymerizable laminate materialJ which process comprises
applying to the surface of the support an adhesion-imparting substance and a
thermoplastic photopolymerizable copying layer, the adhesion imparting sub-
stance being in contact with the support surface and being applied either as
a separate layer or evenly distributed throughout the thermoplastic photo-
:
polymerizable copying layer, the adhesion imparting substance having theformula
~ - tCHz)n - CO - N ~ ~ 2
in which
m is 1 or 2,
n is 1 or 2,
Rl is H, halogen or an alkyl or alkoxy group, and
R2 is halogen or an alkyl or alkoxy group.
One preferred form of the invention is a photopolymerizable lamin-
ate material comprising the flexible base, the thermoplastic photopolymeriz-
able copying layer, the adhesion-imparting substance and a peelable protective
;` coating on the surface of the copying layer away from the base.
Halogen atoms, i.e. fluorine, chlorine, bromine, or iodine atoms,
may be used as substituents Rl and R2, with fluorine, chlorine and bromine
being preferred. Among the alkyl and alkoxy groups, those having from 1 to 4
carbon atoms are preferred.
-4-
K 23~3
,
1~:)7595~
Both, in layers applied in the form of liquid solu-
tions to copper supports, as also in layers laminated to cop-
per supports by a dry transfer process, the new adhesion-
imparting substances are very effective. In comparison with
known adhesion-improving agents, their effest is particular-
ly conspicuous i~ the latter process, because in this case
adhesion poses the greater problem.
As already mentioned, the adhesion-imparting sub-
stances may be either incorporated in the photopolymerizable
copying layer, or used in the form of a separate interme-
diate layer between the copper support and the copying layer.
Which of these possibilities is selected largely depends on
which is more advantageous in each individual case. Incorpor-
ation in the layer saves a process step, but the effect of the
same quantity per unit of surface area is more pronounced
when the substance is concentrated at the boundary layer.
In the case of relatively expensive adhesion-imparting sub-
stances, it is therefore preferred to use them in the form
of a separate layer. The separate layer may be easily ap-
pliçd after the customary preliminary clea~ing of the copper
surfacP. Alternatively, it is also possible to apply the ad-
hesion-imparting layer to the surfa~e of the photopolymeri-
zable l,ayer during the manufacture of the dry resist, for
example by coating it onto the normally provided protective
coating and laminating the coated surface to the photopoly-
m~rizable layer.
When the copyir.g layer is applied to the copper
surface from a solution, the procedure described on pages 4
~07S955 K 2343
and 5 of German O~fenleguncJsschrift No. 2,028,773, is follo-~-
ed.
~ hen the copying layer is applied as a dry ~esist
to the s~pport to be modified, the process describe~ in U. S.
Patent Nos, 3,622,334, and 3,645,772, is used. I'he transfer
materi~ls used are lamina-tes composed of a dimensionally sta-
ble film base, the dry resis-t layer, and prefera~ly a protec-
tive coating, suçh as those discloqed i~ U. S, Patent No.
3,469,9B2, or German OEfenlegungsschrift ~o. 2,123,702.
Plate$ or foils of co~per or copper alloys, e.g.
of brass, tombac, bronza, alumi~um b~onze, nickel silver, or
Monel metal, ma~ be used as the supports which are to be co~t-
ed and modified. The plate o~ foil ~ay be backed by a car-
rier o~ some other material, e.g. py an aluminum, steel, or
plastic $oil o~ a plate of insuiating materi~l, e.g. of ~
synthetic xesin moldin~ ~aterial, ~he products obtaine~ by
lm~ge-wise ~odi~ication of the Supp~rt~ esp3cially by etFhing
- or electxopl~ting, may ke used ~qr the prep~ration of relie$,
gxaVuxe or pl~ogra~hic printin~ plates, for the ma~ufacture
~p of printe~ and integrated circuits, and ~or chemical mi~lin~.
~ he photop~ly~eriæable layers used in the p.ocess
accordin~ to the invention are comp3sed of ~ hig~ molec~l~r
~eight binder, polyme~izable unsaturated compounds, and pho-
toiniti~tors.
Suitable poly~erizable compounds are kno~n an~ d~-s-
~ cribe~, f~r ~xample, in U. S. P~ent ~os, ~,760,863, and
3,060,023. Acrylic and me~hacrylic esters, such as diglyce~-
ol diacrylate, guaiacol glycerol ether diacrylate, neopentvl
6--
~ O~S9~S K 2343
glycol diacrylate, 2,2-dimethylol-butanol-(3)-diacrylate, and
the acrylates and methacrylates of polyesters of the "Desmo-
phen" type containing hydroxy groups are preferred. General-
ly, those compounds are preferred which contain two or more
polymerizable groups. Acrylic and espacially methacrylic es-
ters containing urethane groups are particularly suitable.
Monomers of this type are described in German Offenlegungs-
schriften Nos. 2,064,079, and 2,361,041.
Further, the photopolym2r layer contains at least ¦~
one photoinitiator. Suit3ble initiators are, for example:
hydrazones, five-membered nitrogen-containing heterocycllc
compounds, mercapto compaunds, pyrylium or thiopyrylium
salts, multi-nuclear quinones, synergistic mixtures of differ-
ent ketones, dye/redox systems, and certain acridine, phena-
zine, and quinoxaline compounds.
Polyamides, polyvinyl esters, polyacrylic and poly-
methacrylic esters, polyvinyl acetals, and unsaturated poly-
esters may be used as binders, for example.
Praferably, the binders used should be soluble or
at least swellable in aqueous-alkaline solutions, because
layers containing such binders may be developed with the pre-
ferred aqueous-alkaline developers. Such binders may contain
the ~ollowing groups, for example: -COOH, -PO3H2, -SO3H,
-SO2NH2, -SO2-NH-CO-, and similar groups. Examples of such
binders are: maleinate resins, polymers of N (p-tolylsulfonyl)
-carbamic acid- ~--methacryloyl-oxy-ethyl)-ester and copoly-
mers of these and similar monomers with other monomers, sty-
rene/maleic anhydride copolymers, and methyl methacrylate/
r~de /y~ar~
K 2343
. , , ~
107SgSS
mathacrylic acid copolymers, Preferably, ho~ever, copoly-
mers of methacrylic acid, alkyl methacryla-tes, and methyl
- methacrylate and/or styrene, acrylonitrile, and the like are
used, such as those disclosed in German Offenlegungsschrift-
en Nos. 2,064,0~0, and 2,363,806.
Further, dyestuffs, pigments, polymerization inhi-
bitors, color couplers and hydrogen donors may be added to
the copying layers.
If the adhesion-imparting substances are used as
components incorporated ;in the copying layer, they are
normally added in quantities from 0.05 to 5.0 percent by
weight, based on the weight of the non-:volatile components
of the layer. The preferred quantity is in the range of
about 0.1 to 2.0 per cent by weight, especially between 0.4
and 1.5 per cent by weight.
If the adhesion-imparting substances are applied
as a separate layer to the copper support or to the surface
of the copying layer, they are normally applied in the fo~m
of 0,1 to 5 per cent solutions in organic solvents, or in
mixtures of organic solvents with water, and then dried. It
is important that the quantity of adhesion-imparting sub-
stance deposited be sufficient to form a homogeneous, co-
herent layer. The preferred concentration range is between
about 0.15 and 2.0 per cent by weight. Lower alkanols and
ketones, for example, were found to be suitable solvents.
For performing the process of the invention, the
copper-containing support is cleaned, d`egreased, and possi-
bly roughened in known manner by a mechanical treatment and/
75~S:~ K 2343
or by etching, According to one embodiment of the invention,
the adhesion-imp~rting substance is then applied in the form
of a dilute solution and dried. The polymerizable layer is
then applied on top of this layer, either from a solution or
by dry lamination, applying pressure and heat. During further
processing, the layer is exposed in known manner and the un~
exposed areas of the layer are removed by means of a develo-
per, preferably an aqueous alkaline solution which may contain
small quantities of organic solvents, if desired. In order
to clean the bared areas of the copper support from traces of
the layer or from other impurities which may be present, it
may be advisable to subject the plate to a treatment with an
oxidizing agent, for example an aqueous solution o~ ammonium
peroxy disulfate. The copper surface is then etched in the
normal manner, or metal is d~posited in the bared areas by
an electroplating or electroless plating process. The har-
dened photoresist layer is then removed in known manner by
means of organic solvents and/or a~ueous alkaline solutions.
According to another embodiment of the inventive
- 20 process, thq adhesion-imparting substance is applied together
with the copying layer. In this case, the adhesion-imparting
substance Lnay be evenly distributed in the co3ting solution
or in the pre-fabricated dry resist layer, or it may be pre-
sent in the form of a separate layer on the surface of the dry
resist layer. Further processing is qs described above.
The adhesion-imparting substances used ~ccording to
the present invention effect an excellent adhesion between the
hardened photopolymer layer and the copper support. The adhe-
_9_
~ gS S K 2343
. ',~
sion produced by the p~esent invention substantially exceeds
that resulting from known adhesion-imparting agents. The `
adhesion is so good that the plates may be etched or elec-
troplated in strongly acid baths without parts of the re-
sist layer being undercut at the boundary surface or sepa-
rated from the support. This advantage is particularly
evident when strongly acid galvanic gold baths and very severe
conditions are employed, for example twice the normal current
density.
Surprisingly, lt was found, however, that after
the etching or electroplating proce~s, the resist layer may
be removed more easily and rapidly with conventional sol-
vents than a comparable resist layer which had been produced
without the use of the new adhesion-imparting substances.
Some of the aromatic merc3pto alkanoic acid amides
used according to the invention as adhesion-imparting sub-
~tances ~re new, others already have been described in the
literature. The new compounds a~e obtained analogously to
the preparation of the known compounds.
The compounds are prepared by mixing 2-mercapto
acetic acid or 3-mercapto propionic ~cid with an equivalent
quantity of the appropriate aniline and heating the mixture
for several hours in a nitrogen atmosphere to temperatures
ranging from about 130 to 170C, until the water formad has
evaporated. The reaction mixture is then dissolved in a
suitable solvent and the anilide is precipitated by intro-
ducing the mixture into water while stirring.
The following table contains a list of suitable
adhesion-imparting substances, including their melting
points.
--10--
.. ... . .
1~75955 K ;2343
T a b 1 e
No. of Melting
Compound Desiqnation _ Point (C)
1 2-mercapto-acetic acid-2,4- 1
dichloro-anilide 108 - 110
2 2-mercapto-acetic acid-3,4-
dimethyl-anilide 106 - 108
3 2-mercapto-acetic acid-2-
methoxy-5-ch3oro-anilide 84 - 85
4 3-mercapto-propionic acid-2,4-
dichloro-anilide 10~ - 106
5` 3-mercapto-plopionic acid-4-
fluoro-anilide 66 - 67
6 3-mercapto-propionic acid-3-
methyl-anilide ~ 10
7 3-mercapto-propionic acid-4-
methoxy-anilide 75 - 76
8. N, N'-bis-(3-merca~pto-propionyl)-
1, 3-phenylene-diamine 107 - 108
`~ 9 N, N'-bis-(3-mercapto-propionyl)- 278
1, 4-phenylene-diamine ~(with decompos.)
The ~ollowing examples illustrate preferred embodi-
ments of the inventive process and material. The relation
between parts by weight and parts by volume is the same as
between grams and milliliters. Percentages are by weight un-
less stated otherwise. The parts by weight of monomer units
in the polymers are the quantities used for polymerization.
Examples ~ to g
A solution of
5.6 parts by weight of the reaction product of 1
K 2343
107S9SS
mole of 2, 2, 4-trimathyl-hexamethylene-diiso-
- cyanate and 2 moles of 2-hydroxy-ethyl-metha-
crylate,
6.5 parts by weight of a terpolymer of styrene,
n-hexyl-methacrylate, and methacrylic acid
(10 : 60 : 30) with an acid number o~ about
182,
0.2 part by weight of 9-phenyl-acridine,
- 0.015 part by weight of 4, 4'-bis-dimethylamino-ben-
' zophenoner
0.15 part by weight of triethyleneglycol-dimethacry-
~: .
late, and
0,025 part by weight of a blue azo dyestuff produced
by coupling 2, 4-dinitro-6-chloro-benzene-dia-
zonium salt with 2-methoxy-5-acetylamino-N-
cyanoethyl-N-hydroxyethyl-aniline, in
28.0 parts by-weight of butanone-2
: is whirler-coated onto a 25~ m thick polyethylene terephtha-
late ilm such that a 25~ m thick layer is produced (weight
Qf the layer: 30 g/m2). The layer is further dried for 2
minutes at 100C in a drying oven.
: In order to protect the resulting layer from con-
.. . tamination by dust or rom damage, it is covered with a 20
to 25~ m thick protective coatlng which adheres less strong-
ly to the layer than the polyester base. The resulting
material may be stored in this form over a relatively long
period of time. ~
The copper surface of a phenoplast plate laminated
-12-
.
iL~7595S K- 2 3 4 3
with a 35~m thick copper foil is mechanically cleaned with pumice
powder or a brushing device, thoroughly rinsed with water, and dried
by blowing with oil-free air.
Samples of the cleaned plate are immersed for about 30
seconds in a bath containing, in each case, 1 part by weight of one
of the compounds Nos, 1 to 9 dissolved in 99 parts by weight of
ethanol .
After immersion-coating, the plates are dried with a hat-
air blower and then stored for 5 minutes at 100 C in a drying oven.
In the case of li~uid adhesion~imparting substances, e.g.
compound No. 6, a very thin, oily film remains on the copper surface
which cannot be rinsed off with water. In the case of compounds
which are crystalline at room temperature, a firmly adhering, grey to
white layer of fine particles is formed on the copper surface after
immersion and drying, which also cannot be removed by rinsing with
water.
After peeling off the protective coating, the dry resist is
laminated onto the copper plates pretreated in this manner, using a
laminator, for example the laminator Type 25 marketed by Dynachem
Corporation, Santa FeSprings, USA. The lamination pressure is
adjusted to the highest value, the temperature to 115 - 125 C, and
the feed speed to 0.8 m per minute.
All 9 samples of the resist laminated to copper are then
exposed for 17 seconds through the film base under a negative original,
using a xenon lamp of Klimsch ~ Company, model Bikop, ~ kilowatts,
from a distance of ~0 cm.
~ I~de 1~
.
-- 13 --
~ - ~07$9$s K 2343
After removal of the film base, the unhardened areas
of the layer are washed away with a 0.4 per cent sodium carbon-
ate solution. On the average, development requires 90 se-
conds.
The developed plates are then successively subject-
ed to the following treatments: -
a) Immersion in a 15 per cent aqueous ammonium persulfate
solution until a uniform coppor surface is achieJed, i.e.
until all traces of fogging have disappeared. The times
are given in the table.
30 seconds' rinsing with water.
b) 30 seconds' immersion in 10 per cent by weight sulfuric
acid,
followed by 30 seconds' rinsing with water.
The cleaned, bared areas of the coppsr surface are then elec-
troplated as follows:
c) 30 minutes' treatment, at 2 A/dm2 - based on the area-to
A be coppar-plated - with the "Feinkornkupferplastikbad" of
Messrs. Schlotter, at a tempsrature;of 20 to 25C and a
pH value of less than 1,
followed by 30 seconds' rinsing with water.
d) 10 minutes' treatment, at 4 A/dm2, in the nickel bath of
type "Norma ~ of Messrs. Schlotter, at a temperature of
50 to 55C and a pH value betwaen 3.5 and 4.5,
followed by 30 seconds' rinsing with w~ter.
e) 15 minutes' treatment, at 0.6 A/dm2, with the gold bath f
type "Autronex-N" of Messrs. Blasberg, at a temperature
of 20 to 25C and a pH value between 3.5 and 4.0,
followed by 30 seconds' rinsing with water and drying.
~~r~de ~
-14-
; , :
,~ ,
75955 ~ ~343
For all electroplating baths, the current density
may be doubled, if desired.
In order to remove the hardened areas of the resist,
~! the plate may be successively immersed in a 5 par cant caus-
tic soda solution and in methylene chloride.
- A sample of the plate which had not been treated with
the adhesion-imparting substance cannot be decoated as quick-
ly as a treated sample.
Then, the decoated plates are etched at a temper-
ature of about 42 to 55 C, with an iron-III-chloride solu-
tion of 42Be, using either an etching machine or a rocking
bath, then rinsed with water, and dried by blowing with com-
pressed air. In this manner, the copper areas formerly co-
vered by the resist ~re etched away.
T a b 1 e
- ~xample Compound Superficial E~ching ~dhesion
~o. No. with 15% by weight
(NH4)2S20g(Time in
seconds~
I ~ 55 +++
, 2 2, 160 +++
3 3i 95 +++
q 4 60 +++
~ 5 ~ 130 +++
6 6 90 +++
7 7 160 ++
- 8 8 125 t-~+
~ 9 60 +++
,':
--15--
- , , :
,
_- K ~343
~075~55
. . .. I
+~ = good adhesion
~ = very good adhesion
Examples 10 to 18
For each example, the coating solution used in
Example 1 for the p eparation o~ the photopolymerizable layer
is mixed with 0.15 g = 1.2% (calculated on the solids content)
of one o~ the compounds Nos. 1 to 9, the acid amide being
dissolved in part of the solvent employed.
The photopolymer layers are applied to polyester
films in the manner described in Example 1.
The copper plates are pretreated as described in
Example 1, exc~-pt that no adhesion-imparting layer is applied.
Lamination, exposure, and development are as described in
Example 1. As in Example 1, single or double current densi-
ties may be employed in the gold bath without impairing ~he
resistance of the plate ~o the gold bath, which would be the
case when no adhesion-imparting substance is used.
The table shows how the mercapto fatty acid ani-
lides improve the bond strength at the boundary surface be-
tween the copper surface and the resist layer in the acid
`` electroplating baths.
-16-
~ ~ K 2343
10~9~S
T a_b l e
Example Compound Superficial Etching Adhesion
No. No. with 15% by weight
(~tI4)2S~o~ (Time in
seconds)
..
I 45 ++
11 2 45 +++
1~ 3 30 ++
~ 13 4 45 +++
14 5 60 +
~ 50
16 7 60 +~+
17~ 8 50 ~+
18~ 9. 60 +++
~ ~ '
~ = atisfactory adhesion
'~ ++ a good adhesi.on
+++ - very good adhesion
- ~
ExamPle 19
5.6 parts by weight of the reaction p.oduct of
~ 1 mole of 2,2,4-trimethyl-hexamethylene
diisocyanate and 2 moles of 2-hydroxy-~thyl
. methacrylate,
10.0 parts by weight of a terpolymer of styren~e,
n-butyl-methacrylate, and methacrylic acid
~ (11.3 : 68.7 : 20) with an acid number of
about 125,
-17-
- : ~
~75955 K 2343
0,05 part by weight of 9-phenyl-acridine,
0.15 part by weight of triethyleneglycol dimeth-
acrylate,
0.025 part by weight of the blue azo dyestuff used
in Examples 1 to 9, and
0.31 part by weight of 3-mercapto-propionic acid-
4-methoxy-a~lide(Compound No. 7)
' are dissolved in
i 30.0 parts by waight of butanone-2.
Advantageously, the a_i.d amide is first dissolved in part of
: the butanone.
.. ~he resulting solution is whirler-coated onto a
25~ m thick polyester film in such a manner that a 38~,m
- thick layer (45 g/m2) is produced. The layer is then dried for 3 minutes at 100C in a drying oven.
.' ~ The further procedure is as described .in Examples
10 to 18 except that the exposure time is 40 to 45 sec~nds
because the layer is thicker. The layer is then developéd
within about 2 minutes with a solution o~
. 20 30.0 ~arts by weight of Na2sio3 . 9 H20 and
0.53 part by weight of SrC12 - 8 H2O in
970.0 parts by volume of water.
~he resist containing the.adhesion-imparting substance has an .
excellent adhesion. Single and double current densities may
be used with all electroplating baths.
Example20 '
A copper-phenoplast laminate cleaned with pu~ice
powder is thoroughly rinsed with water and then dried by blow- :~
-18-
~ K 2343
~L~7S9SS
ing with oil-free air.
The plate is then immersed for 30 seconds in a pre-
treating bath containing
1 p3rt by weight of 3-mercapto-propionic acid-2,
4-dichloro-anilide (Compound No. 4) and
99 parts by waight of ethanol.
The solution iS allowed to drip off and the plate
is then dried with a hot-air blower, Finally, the plate is stored for
5 minutes at lOO~C in a drying oven.
The thus pretreated copper surface is then lamina-
ted with a dry resist layer at a temperature of approximately
115 to 120C by means of the laminator used in Examples 1 to
The dry resist layer is produced by whirler-coating
I a solution of
- 5.6 parts by waight of a cop~lymer of
175 p.b.w. of 2-ethyl-hexyl-methacrylate,
- 30 p.b.w. of acrylonitrile,
20 p.b.w. of ethyl methacrylate, and
95 p.b.w. of methacrylic acid,
5,6 parts by weight of a monomer obtained by
reacting 1 mole of 2,2,4-trimethyl-hexamethy-
lene-diisocyanate with 2 moles of hydroxy-
ethyl-methacrylate,
0.15 part by weight of triethyleneglycol-dimethyl
acrylate,
0.2 part by waight of 9~phenyl-acridine,
0.015 p3rt by weight of Michler's ketone,
--19--
_ K 2343
` 1~7595S
0.04 part by weight of the blue azo dyestuff used
in Ex~ 1, in
20.0 p~rts by weight of ethyleneglycol monoethyl
ether and
12.5 parts by weight of methyl ethyl ketone,
onto a 25~ m thick polyester film. After drying for 2 minutes
at a temperature of 100C, a lay~r weighing 30 g/m2 is ob-
tained.
The laminated layer is exposed for 20 seconds,
then wiped over for 1 tc 2 minutes with a solution of
1,000.0 parts by weight of water,
15.0 parts by weight of Na2Sio3 9 H20,
3.0 parts by welght of polyglycol 6,000,
0.6 part by weight of levulinic acid, and
0.3 part by weight of Sr(OH)2 8 H20,
and finally rinsed with water. `
The electroplating process is as described in
Examples 1 to 9.
By the use of the described adhesion-imparting sub- I
,. . ..
stance, the resistance to the gold bath is improved.
The hardened image areas are removed with acetone
and the bared copper areas are then etched in an etching ma- ¦
chine with an iron-III-chloride solution of 42Be, rinsed
with water, and dried by blowing with compressed air.
Example 21
A solution of
5.6 parts by weight of the reaction product of
1 mol* of hexamethylene diisocyanate and
2 moles of hydroxypropyl methacrylate,
`
K 2343
~07
6.5 parts by weight of a terpolymer of styrene,
n-hexyl-methacrylate, ànd methacrylic acid
(10 : 6~ : 30) with an acid number of about
185,
0.2 part by weight of 9-phenyl-acridine,
0.15 part by weight of triethyleneglycol dimetha-
crylate~
0.015 p~rt by weight of 4,4'-bis-dimethylamino-
benzophenone,
; 10 0.024 part by weight of the blue azo dyestuff used
in Examples 1 to 9,
0.15 part by weight of 3-mercapto-propionic acid-
2,4-dichloro-anilide(Compound No.4), in
30.0 parts by weight of butanone-2,
is whirler-coated onto a 25~ m thick polyester film in a
manner such that a 25~ m thick layer, we ghing 30 grams per
square meter, is produced. The layer is then dried for 2"
minutes at 100C in a drying oven.
The further procedure is as described in Examples
1 to 9. The gold bath may be used with normal or double
current density, without impairing the resistance of the mate-
rial to the gold bath. Decoating of the hardened areas of
the layer with acetone or with a 5 per cent caustic soda solu-
tion and mathylene chloride is facilitated by the addition
of the adhesion-imparting substance.
It will be obvious to thase skilled in the art
that many modifications may be made within the scope of the
present invention without departing from the spirit thereof,
and the invention includes all such modifications.
-21-
