Radiation-reactive precursor stages of highly heat-resistant polymers

The invention relates to oligomeric and/or polymeric radiation-reactive precursor stages of polymers on the basis of heterocycles and has the objective to make available radiation-reactive precursor stages of this kind in which the problems arising due to the need of using organic solvents are eliminated. For this purpose, the invention provides addition products of cyclic carboxylic-acid anhydrides with hydroxyl group-containing compounds, where the hydroxyl group-containing compounds represent addition products of olefinically unsaturated monoepoxides on carboxyl group-containing prepolymers of polyimides, polyisoindoloquinazoline diones, polyoxazine diones and polyquinazoline diones or on amino group-containing prepolymers of polyimidazoles and polyimidazopyrrolones or on hydroxyl group-containing prepolymers of polyoxazoles. The radiation-reactive precursor stages according to the invention are suited, for example, for the manufacture of highly heat-resistant relief structues.

BACKGROUND OF THE INVENTION 
The present invention relates to oligomeric and/or polymeric, 
radiation-reactive precursor stages on the basis of heterocycles. 
Precursor stages of polymers on the basis of heterocycles are known, for 
example, from German Pat. No. 2 308 830 and its corresponding U.S. Pat. 
No. 3,957,512. These polymer precursor stages are polyaddition or 
polycondensation products of polyfunctional carbocyclic or heterocylic 
compounds, carrying radiation-sensitive radicals, with diamines, 
diisocyanates, bis-acid chlorides or dicarboxylic acids. The compounds, 
carrying radiation-sensitive radicals, contain two carboxyl, 
carboxylic-acid chloride, amino, isocyanate or hydroxyl groups suitable 
for addition or condensation reactions and in part, in ortho- or 
peri-position thereto, radiation-reactive groups bound to carboxyl groups 
in ester-fashion. The diamines, diisocyanates, bis-acid chlorides and 
dicarboxylic acids to be reacted with these compounds have at least one 
cyclic structure element. 
The known polymer precursor stages serve to prepare protective and 
insulating layers as well as relief structures of highly heat-resistant 
polymers, into which they are converted by light exposure and, optionally, 
subsequent annealing. In the process, particularly polymers of the 
following classes of substances are obtained: Polyimides (including 
polyamidimides and polyester imides), poly-1,3-quinazoline-2,6-diones, 
polyisoindoloquinazoline diones, poly-1,3-oxazine-6-ones and 
polybenz-1,3-oxazine-2,4-diones. 
The known polymer precursor stages, which can be cross-linked by radiation 
and can, therefore, be structured by photo-techniques, are soluble in 
organic solvents. If organic solvents are used, however, problems arise, 
particularly with respect to toxicity, flammability and swelling and the 
destruction of sealing materials as well as disposal problems. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to make available 
radiation-reactive precursor stages of the type mentioned at the outset, 
with which the problems connected with the use of organic solvents are 
eliminated. 
According to the present invention, this and other objects are achieved by 
the provision that the precursor stages consist of addition products of 
cyclic carboxylic-acid anhydrides with hydroxyl group-containing 
compounds, where the hydroxyl group-containing compounds are addition 
products of olefinically unsaturated mono-epoxides 
on carboxyl group-containing polyaddition products of aromatic and/or 
heterocyclic tetracarboxylic-acid dianhydrides and diamino compounds or 
diamino compounds with at least one ortho-position amido group or on 
carboxyl group-containing polyaddition products of aromatic and/or 
heterocyclic dihydroxydicarboxylic acids or corresponding 
diaminodicarboxylic acids and diisocyanates; or 
on amino group-containing polycondensation products of aromatic and/or 
heterocyclic tetraamino compounds with dicarboxylic-acid chlorides or 
esters, or on amino group-containing polyaddition products of the 
tetraamino compounds and tetracarboxylic-acid dianhydrides or 
on hydroxyl group-containing polycondensation products of aromatic and/or 
heterocyclic dihydroxydiamino compounds with dicarboxylic-acid chlorides 
or esters. 
The radiation-reactive precursor stages of highly heat-resistant polymers 
according to the present invention have the essential property that they 
are highly soluble in aqueous alkaline solvents. This property is of 
importance particularly for the resist technology since here, not only 
working in or out of an aqueous solution is possible, but the problems 
which arise when organic solvents are used are also eliminated. Through 
the invention, reactive precursor stages of highly heat-resistant polymers 
with negative-resist properties are made available for the first time, 
which can be developed, like positive resists, in aqueous alkaline 
solution and can, therefore, be structured photo-technically without the 
use of organic solvents. Through the use of the polymer precursor stages 
according to the present invention, which can, incidentally, be prepared 
in a simple manner, advantages are therefore obtained with respect to 
economy and ecology. 
The polymer precursor stages according to the present invention are 
particularly well suited for the preparation of structured, highly 
heat-resistant protection and insulating layers in microelectronics 
(generation of fine structures) as well as for use as photo-resists (see 
in this connection the concurrently filed U.S. Patent Application "Method 
For The Preparation Of Highly Heat-Resistant Relief Structures And The Use 
Thereof", Ser. No. 270,357. 
The radiation-reactive precursor stages according to the invention have 
generally the following structure: 
##STR1## 
In Formulas (1) and (2), n is an integral number from 2 to about 100; m, v 
and w are 0 or 1. The following applies to R, R.sup.1, R.sup.2, R.sup.3, A 
and D: 
R is an optionally halogenated, at least partially aromatic and/or 
heterocyclic, tetravalent, i.e., tetrafunctional radical, in which two 
valences respectively are arranged in adjacent positions; if the radical R 
has several aromatic and/or heterocyclic structure elements, then the 
pairs of valences are situated at respective end-position structure 
elements of this type; 
R.sup.1 is an optionally halogenated divalent, i.e., difunctional radical 
of aliphatic and/or cycloaliphatic structure, optionally having 
heteroatoms, and/or aromatic and/or heterocyclic structure; 
R.sup.2 is an olefinically unsaturated radical, for example, an allyl 
ether-containing or a maleinimide-containing group and in particular, an 
optionally substituted, (meth)acrylester-containing group; 
R.sup.3 is an optionally halogenated, divalent, i.e., difunctional radical 
of aliphatic and/or cycloaliphatic, olefinically unsaturated and/or 
aromatic and/or heterocyclic structure; 
A is --O--, --NH-- or 
##STR2## 
and D is 
##STR3## 
--O--, --S--, --NH-- or 
##STR4## 
The following also applies to these structures: 
For m=1 and v=1, A=--NH-- or --O-- and 
##STR5## 
For m=0 and v=1, 
##STR6## 
For m=1 and v=0, 
##STR7## 
and D=--O--, --S-- --NH-- or 
##STR8## 
For m=0 and w=0, v=1. 
The radicals R, R.sup.1, R.sup.2 and R.sup.3 have, in particular, the 
following meaning: 
##STR9## 
where p=0 or 1 and X stands for one of the following radicals: 
##STR10## 
For the further radicals applies: 
##STR11## 
with o=2 to 10 and 
##STR12## 
with p=0 or 1 Z=H or alkyl with 1 to 6 carbon atoms, 
Z.sup.1 =alkyl with 1 to 10 carbon atoms or aryl, 
Z.sup.2 =aryl or heteroaryl and 
##STR13## 
where q=2 to 14 and r=2 to 18, and Z.sup.1 and Z.sup.2 are defined as 
above. 
##STR14## 
where p=0 or 1, q=2 to 14 and r=2 to 18, and Z.sup.1 is defined as above; 
##STR15## 
wherein Z, Z.sup.1 and Z.sup.2 are defined as above. 
##STR16## 
where s=2 to 16; X.sup.2 =--CH.sub.2 -- and --CH.sub.2 
--O--(CH.sub.2).sub.r --O].sub.t --(CH.sub.2).sub.3 --; and 
Y.sup.2 =--H, --CH.sub.3, --Cl, --Br or --C.tbd.N, where r=2 to 18, s=2 to 
16 and t=1 to 10. 
##STR17## 
where s=2 to 16 and Y.sup.2 is defined as above. 
The radiation-reactive precursor stages according to the present invention 
are addition products of cyclic carboxylic-acid anhydrides with hydroxyl 
group-containing compounds. The hydroxyl group-containing compounds, in 
turn, are addition products of olefinically unsaturated monoepoxides on 
carboxyl group-containing or amino group-containing or hydroxyl 
group-containing prepolymers. These hydroxyl group-containing compounds, 
which are precursor stages of polyimides, polyisoindoloquinazoline diones, 
polyoxazine diones, polyquinazoline diones, polyimidazoles, 
polyimidazopyrrolones and polyoxazoles, are the subject of 
commonly-assigned U.S. Patent Applications Ser. No. 179,453, Ser. No. 
179,455 and Ser. No. 179,462, all filed on Aug. 19, 1980. 
To the mentioned hydroxyl group-containing compounds, cyclic 
carboxylic-acid anhydrides are added. These anhydrides have the following 
structure (3), where the radical R.sup.3 has the meaning given above: 
##STR18## 
Preferred here are maleic-acid anhydride and itaconic-acid anhydride. 
Further anhydrides are, for example, succinic-acid anhydride and 
phthalic-acid anhydride. 
The structure of the radiation-reactive precursor stages according to the 
invention are illustrated with the aid of the following formulas (4) to 
(10): 
##STR19## 
In formulas (4) to (10), the following radiation-reactive polymer precursor 
stages are shown: 
(4) addition product of a carboxylic-acid anhydride and a polyimide 
precursor stage, obtained by addition of glycidylmethacrylate on the 
polyaddition product of pyromellithic-acid anhydride and 
4,4'-diaminodiphenyl ether; 
(5) addition product of a carboxylic-acid anhydride and a 
polyisoindoloquinazoline dione precursor stage, obtained by addition of 
glycidylmethacrylate on the polyaddition product of pyromellithic-acid 
anhydride and 4,4'-diaminodiphenyl-3,3'-dicarboxylic-acid amide: 
(6) addition product of a carboxylic-acid anhydride and a polyoxazine dione 
precursor stage, and specifically a polybenzoxazine dione precursor stage, 
obtained by addition of glycidylacrylate on the polyaddition product of 
4,4'-dihydroxydiphenylmethane-3,3'-dicarboxylic acid and 
4,4'-diphenylmethanediisocyanate; 
(7) addition product of a carboxylic-acid anhydride and a polyquinazoline 
dione precursor stage, obtained by addition of glycidylmethacrylate on the 
polyaddition product of 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid 
and 4,4'-diphenylmethanediisocyanate; 
(8) addition product of a carboxylic-acid anhydride and a polyimidazole 
precursor stage, and specifically a polybenzimidazole precursor stage, 
obtained by addition of glycidylmethacrylate on the polycondensation 
product of 3,3'-diaminobenzidine and isophthalic-acid dimethyl ester; 
(9) addition product of a carboxylic-acid anhydride and a 
polyimidazopyrrolone precursor stage, obtained by addition of 
glycidylmethacrylate on the polyaddition product of 3,3'-diaminobenzidine 
and pyromellithic-acid dianhydride; 
(10) addition product of a carboxylic-acid anhydride and a polyoxazole 
precursor stage, and specifically a polybenzoxazole precursor stage, 
obtained by addition of glycidylmethacrylate on the polycondensation 
product of 3,3'-dihydroxybenzidine and isophthalic-acid dichloride. 
The term "polyimides", incidentally, also includes compounds such as 
polyester imides, polyamidimides and polyquinazolinedionimides. "Diamino 
compounds" are understood to include also derivatives of hydrazine; in the 
reaction of such compounds with tetracarboxylic-acid dianhydrides, 
so-called polyhydrazines are produced. 
In addition to being used as photoresists and for the manufacture of 
protection and insulating layers, where structuring takes place, the 
precursor stages according to the present invention can also serve 
generally, in non-structured form, for manufacturing protective and 
insulating coatings. To particular advantage, these precursor stages can 
be used for preparing plastic coatings for light-conducting fibers of 
optical waveguides. 
DETAILED DESCRIPTION OF THE INVENTION 
The invention is explained in still further detail with reference to the 
following embodiment examples:

EXAMPLE 1 
Preparation Of A Radiation-Reactive Precursor Stage For Polybenzoxazole 
To a solution of 6.49 parts by weight 3,3'-dihydroxybenzidine in 50 parts 
by volume dimethylacetamide and 9 parts by volume pyridine, 6.1 parts by 
weight isophthalic-acid dichloride in 20 parts by volume cyclohexanone are 
added dropwise, while stirring intensively, at a temperature of -5.degree. 
to -20.degree. C. within about 30 minutes. After continued stirring at 
room temperature for 3 hours, the viscous reaction solution is allowed to 
stand overnight; the solution then is added dropwise to 1000 parts by 
volume water, while stirring. The resin precipitated thereby is separated, 
washed with water and methanol and dried in a vacuum at about 60.degree. 
C. 
10 parts by weight of the polybenzoxazole prepolymer prepared in the manner 
described are dissolved in 100 parts by volume N-methylpyrrolidone. To 
this solution are added 50 parts by volume glycidylmethacrylate, 0.5 parts 
by volume benzyldimethylamine and 0.5 parts by weight hydroquinone. After 
heating for 2 hours to a temperature of about 90.degree. C., the reaction 
product is precipitated, while stirring, from 1000 parts by volume ethanol 
and is dried in a vacuum to yield a yellow-brown powder. 
3.2 parts by weight of the addition product obtained, which is no longer 
soluble in an aqueous alkaline solution, are dissolved in 35 parts by 
volume N-methylpyrrolidone. While stirring, 1 part by weight itaconic-acid 
anhydride is added to this solution. After a reaction time of 20 hours at 
room temperature, heat is applied for 3 hours at 50.degree. to 60.degree. 
C. The reaction solution then is added dropwise to 500 parts by volume 
water, while stirring vigorously. The precipitate collected is drawn off 
and dried at room temperature in a vacuum. The resin obtained is soluble 
in 0.7% sodium hydroxide solution. The IR spectrum shows a wide band at 
3100 to 3400 cm.sup.-1, which can be related to the carboxyl group. 
EXAMPLE 2 
Preparation Of A Radiation-Reactive Precursor Stage For Polybenzimidazole 
10.7 parts by weight 3,3'-diaminobenzidine are dissolved in 95 parts by 
volume N-methylpyrrolidone and heated, together with 9.7 parts by weight 
isophthalic-acid dimethyl ester, for 8 hours to a temperature of 
150.degree. to 175.degree. C. and subsequently for 2 days to approximately 
185.degree. C. To this solution are then added 40 parts by volume 
glycidylmethacrylate. After a reaction time of 48 hours at room 
temperature and 4 hours at about 50.degree. to 60.degree. C., 8 parts by 
weight itaconic-acid anhydride are added to the reaction mixture. After a 
reaction time of 4 days at room temperature, the reaction product is 
precipitated with 1000 parts by volume water and dried in a vacuum. The 
resin obtained is soluble in an aqueous alkaline solution and exhibits a 
broad absorption in the IR spectrum between 3100 and 3400 cm.sup.-1 which 
can be related to the COOH group. 
EXAMPLE 3 
Preparation Of A Radiation-Reactive Precursor Stage For Polyimide 
To 65.4 parts by weight pyromellithic-acid dianhydride (0.3 mol) in 450 
parts by volume dimethylacetamide are added, while stirring, 45 parts by 
weight 4,4'-diaminodiphenyl ether (0.23 mol) and subsequently, the 
solution is stirred for 2 hours at room temperature. Then, 2 parts by 
weight methacrylic acid-2-hydroxyethyl ester (0.016 mol) are added to the 
reaction mixture in order to bind the still present end-position anhydride 
groups. After stirring at room temperature for 2 hours, 150 parts by 
volume glycidylmethacrylate, 1.5 parts by volume benzyldimethylamine and 
0.1 parts by weight hydroquinone are added to the reaction solution. 
Subsequently, the solution is warmed to a temperature of 50.degree. to 
60.degree. C. while stirring for 23 hours and then is added dropwise to 
4000 parts by volume ethanol while stirring vigorously. The precipitate 
formed is drawn off and is dried in a vacuum at room temperature. The 
reaction product is no longer soluble in an aqueous alkaline solution but 
can be dissolved in polar organic solvents. In the IR spectrum, the 
polyimide precursor stage shows an ester band at 5.8 .mu.m. 
35 parts by weight of the polyimide precursor stage obtained are dissolved 
in 100 parts by volume dimethylacetamide, and 10 parts by weight maleic 
acid anhydride are added thereto. After a reaction time of 5 days at room 
temperature, the resin solution is diluted with 50 parts by volume 
dimethylacetamide and precipitated from 2500 parts by volume water. The 
resin is washed with water and is dried in a vacuum. The yellowish powder 
obtained is soluble in an aqueous alkaline solution. The IR spectrum shows 
the COOH absorption band at 3100 to 3400 cm.sup.-1. 
EXAMPLE 4 Preparation Of A Radiation-Reactive Precursor Stage For 
Polyamidimide 
50 parts by weight of a polyamidimide prepolymer prepared from 
2,6-diaminopyridine and trimellithic-acid anhydride are dissolved in 100 
parts by volume dimethylacetamide and reacted, while stirring, with 0.05 
parts by volume benzyldimethylamine, 0.05 parts by weight hydroquinone and 
75 parts by volume glycidylmethacrylate. The solution is warmed for 19 
hours to a temperature of 50.degree. to 60.degree. C. and subsequently, 10 
parts by weight phthalic-acid anhydride are added. After a reaction time 
of 6 days at room temperature, the resin is precipitated from 2000 volume 
parts water and is dried. The so obtained light-brown powder is soluble in 
an aqueous alkaline solution. 
EXAMPLE 5 
Preparation Of A Radiation-Reactive Precursor Stage For 
Polyisoindoloquinazolinedione 
11 parts by weight 4,4'-diaminodiphenyl-3,3'-dicarboxylic acid amide are 
made into a suspension with 120 parts by volume dimethylacetamide and are 
reacted, while stirring, with 10 parts by weight pyromellithic acid 
dianhydride, dissolved in 100 parts by volume of a 
dimethylacetamide/dimethylformamide mixture (volume ratio 1:1). After 
stirring for 2 hours, 25 parts by volume glycidylmethacrylate, 0.5 parts 
by volume benzyldimethylamine and 0.05 parts by weight 
hydroquinonemonoethyl ether are added to the solution obtained. After 
stirring for 25 hours at a temperature of 60.degree. C., a resin is 
precipitated from the solution with 3000 parts by volume propanol, and is 
dried. This resin is no longer soluble in aqueous alkaline solutions and 
shows an ester band in the IR spectrum at 5.8 .mu.m. 
10 parts by weight of the resin are dissolved in 100 parts by volume 
dimethylacetamide and reacted with 5 parts by weight maleic acid 
anhydride. After letting the solution stand for 5 days at about 30.degree. 
C., the reaction solution is added dropwise to 1000 parts by volume water 
and the precipitated resin is dried, a light-brown powder being obtained 
which is soluble in an aqueous alkaline solution. 
EXAMPLE 6 
Preparation Of A Radiation-Reactive Precursor Stage For 
Polyquinazolinedionimide 
From 22 parts by weight pyromellithic acid dianhydride, dissolved in 200 
volume parts dimethylacetamide, and 27 parts by weight 
3-(p-aminophenyl)-7-amino-2,4-(1H, 3H)-quinazoline dione, dissolved in 150 
volume parts dimethylacetamide, a polyquinazolinedionimide prepolymer is 
obtained after a reaction time of 2 hours at room temperature while 
stirring. 
To the solution of this prepolymer in dimethylacetamide, 2 parts by volume 
acrylic-acid-2-hydroxyethyl ester are added. After stirring for 1 hour, 
the reaction solution is reacted with 50 volume parts glycidyl acrylate, 
0.5 parts by volume benzyldimethylamine and 0.05 parts by weight 
hydroquinone. After heating to a temperature of about 60.degree. C. for 20 
hours, 10 parts by weight succinic acid anhydride are added to the 
solution. After a reaction time of 4 days at room temperature, a slightly 
brownish resin which is soluble in an aqueous alkaline solution is 
obtained by precipitation in 2000 volume parts water. 
EXAMPLE 7 
Preparation Of A Radiation-Reactive Precursor Stage For Polybenzoxazine 
Dione 
To a solution of 28.8 parts by weight methylenedisalicylic acid (0.1 mol) 
and 0.1 parts by weight 1,4-diazabicyclo(2,2,2)octane (as catalyst) in 100 
volume parts N-methylpyrrolidone, 25 parts by weight p,p'-diphenylmethane 
diisocyanate (0.1 mol), dissolved in 50 volume parts N-methylpyrrolidone, 
are slowly added dropwise while stirring. After a reaction time of 20 
hours at room temperature, 75 parts by volume glycidyl acrylate and 0.1 
parts by weight hydroquinone are added to this solution while stirring. 
After a further reaction time of 20 hours at a temperature of 50.degree. 
to 60.degree. C. and 48 hours at room temperature, the resin is 
precipitated with 2000 volume parts toluene and is dried in a vacuum. 
5 parts by weight of the dried resin are dissolved in 20 volume parts of a 
dimethylacetamide/dioxane mixture (volume ratio 1:1) and are reacted with 
1 part by weight maleic acid anhydride. After standing at room temperature 
for 6 days, a resin soluble in an aqueous alkaline solution is obtained by 
precipitation in 50 volume parts water. 
EXAMPLE 8 
Preparation Of A Radiation-Reactive Precursor Stage For Polyquinazoline 
Dione 
1.4 parts by weight 4,4'-diphenylmethane diisocyanate are dissolved at 
about 100.degree. C. in 110 parts by weight polyphosphoric acid and then 
heated to about 140.degree. C. To the so obtained solution, 1.36 parts by 
weight 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid are added under 
nitrogen. The reaction mixture is stirred vigorously for 5 hours at a 
temperature of 150.degree. to 155.degree. C.; after the mixture has cooled 
down, precipitation with 1000 volume parts water follows and the 
yellow-brown product obtained (2.7 parts by weight) is dried. The 
non-radiation-reactive prepolymer, a polyureic acid, shows an absorption 
at 1670 cm.sup.-1 in the IR spectrum which is typical of the urea 
grouping. On the other hand, no quinazoline dione bands appear which would 
have to be located at 1730 cm.sup.-1, i.e, no partial cyclization has yet 
taken place. 
2.7 parts by weight of the polyureic acid obtained in the manner described 
are dissolved in 50 volume parts N-methylpyrrolidone, reacted with 0.5 
volume parts benzyldimethylamine, 0.5 parts by weight hydroquinone and 20 
volume parts glycidylmethacrylate while stirring, and warmed for 20 hours 
to a temperature of about 60.degree. C. Thereupon, 1 part by weight maleic 
acid anhydride is added and, after a reaction time of 7 days at room 
temperature, the solution is precipitated from 50 volume parts water. The 
separated resin is practically colorless and is soluble in 1% aqueous 
sodium hydroxide solution.