CA2023661A1

CA2023661A1 - Reaction product, preparation thereof and radiation-sensitive mixture preparable therewith

Info

Publication number: CA2023661A1
Application number: CA002023661A
Authority: CA
Inventors: Friedrich Seitz; Erich Beck; Joachim Roser; Eleonore Bueschges; Thomas Zwez; Guenther Schulz
Original assignee: Individual
Current assignee: BASF SE
Priority date: 1989-08-22
Filing date: 1990-08-21
Publication date: 1991-02-23
Also published as: DE3927631A1; KR910004694A; JPH0397718A; EP0415175A3; AU6117790A; EP0415175A2

Abstract

- 28 - O.Z. 0050/41047 Astract of the Disclosure: Novel ureido- and carboxyl-containing reaction products which are suitable for preparing radiation-sensitive compositions, in particular compositions whose solubility in water or aqueous alkali increases on irradiation, are obtained by reacting i) a di- or polyisocyanate with ii) at least one amino compound and iii) at least one anhydride of an at least dibasic carboxylic acid, with or without iv) z compound which is dif:ferent from compound ii) and has hydroxyl or amino groups, the total number of NCO and anhydride groups in i) and iii) being equal to or less than the number of groups in ii) and iv) which are reactive therewith.

Description

~2 ~
o.Z. 0050/~1047 Reaction product preparatlon thereof and radiati3n-sen~itive mixture preparable therewith The present invention relates to novel reaction products which contain ureido and carboxyl groups, to S processes Eor preparing s~me and also to radiation-sensitive mixtures which contain these reaction products as well as polymerizable ethylenically unsaturated compounds ~ith or without an initiator system which produces free radicals on irradiation with actinic light.
~ore particularly, the present invention relates to those radiation-sensitive mixture~ which on irradiation become soluble in ~water or aqueous alkali.
Positive-working light-sensitive compositions, ie. compounds or mixtures of compounds whose solubility in a given solvent increases on irradiation, are known per se. The compounds most frequently used in reproduc-tion technology are naphthoquinonediazides and derivat-ives thereof (cf. W. Fra~, Chemie in unserer Zeit, 17 (1983), 10; H.W. Vollmann, Angew. Chem. 92 (1980) 95). On irradiation these compounds eliminate nitrogen and undergo a ~olff rearrangement which converts a hydro-phobic diazoketone unit into a carboxyl group which renders the compounds mentioned, or mixtures containing these compo~mds, soluble in aqueous alkali.
A further class of compounds which are suitable for preparing positive-working light-sensitive mixtures are aromatic or heteroaromatic nitro compounds. Whereas the above-described compounds with a diazoketone struc-ture are usually present in light-sensitive mixtures as low molecular weight compounds, light-sensitive nitro compounds can be used not only in the form of low molecu-lar weight compounds (DE-A-22 07 574), US-A-4 181 531) but also as polymers formed from monomers having an o-nitrocarbinol ester structure or copol~mers of these monomers with other vinyl compounds (cf. DE-A-21 50 691, DE-A-29 22 746 and EP-A-l9 770). Here too irradiation results in the formation of a carboxyl group which 2 ~
- 2 - o.z. 0050/41047 increases the solubility of the mixtures in aqueous alkali .
A similar principle is probably at work with the positive syst~3ms which are described for example in US-A-4 469 774 and which contain photochemically cleavable benzoin ester; in the side chain.
A further instance of solubi7 zation due to carboxyl groups is described for example in EP-A-62 474, EP-A-99 949 or US-A-4 415 652. The mixture contains a water-insoluble binder, a mercaptocarboxylic acid and an initiator sys1tem which forms free radicals on irradia-tion. Irradiation causes a free radical graft of the mercaptocarbo~lic acid onto the binder, thereby render-ing the latter soluble in aqueous alkali.
In photosensitive mixtures devised according to one of the above-described principles, only at most one carboxyl group is formed or grafted onto the binder per quantum of light absorbed. Usually the quantum yield is still distinctly below 1. For this reason all cases require long axposure times, but the solubility differen-tiation achieved is still poor in most cases. Of the photosensitive systems mentioned, therefore, only those which are based on the Wolf rearrangement of diazoketones have become es1tablished in the marketplace, and this only in the area of positive offset plates or positive resists for ~he fabrication of integrated circuit~. In the case of other prod~lctq, in particular photoresist films for circuitboard manufacture, the long exposure times re-quired and t~he half-aqueous developers required on account of the~ lack of solubility differentiation are unacceptable. rrhe problem of how to dispose of developers will become increasingly important in the future.
A fund,~mentally different way of increasing the ~olubility of a photosensitive layer by irradiation - 35 consist~ in se~lecting the composition of the layer in such a way that the average molecular weight of the binder decreases on irradiation. To this end, groups 2~23~
~ 3 - O.Z. 0050/410~7 which are cleavable by actinic light are incorporated in the main chain of a polymer. Examples of such sys~ems are polyoxymethyl,~ne polymers which contain acetal units formed from o-nitroberlzaldehyde or derivatives of o-nitrobenzaldehyde in the main chain. Such polymers andlight-sensiti~e layers prepared therefrom are described for example in US-A-3 991 033 and US-A-4 1~9 611. In the same way it is also possible to incorporate acetals of o-nitrobenzaldehyde in the main chain of polymers which are essentially polyesters formed lrom a dicarboxylic acid and a difunctional alcohol (cf. US-A-4 086 210). Other polymers which on irradiation react by cleaving the main chain and hence reducing the molecular weight are poly-mers which contain hexaarylbisimidazole units in their main chain tcf. US-A-4 009 040).
A combination of main chain degradation and grafting with a carboxyl group is the principle exploited in EP-A-57 162 where unsaturated carboxylic acids are present as well as a polymer which contains benzoin units in the main chain. On irradiation the benzoin units split and reduce the average molecular weight. At the same tLme the unsaturated carboxylic acids undergo addition to the free radicals formed at the cleavage sites and thus likewise increase the solubility in aqueous alkali.
Again the positive-worXing photosensitive layers based on the main chain degradation of a suitable polymer according to one of the principles described above are not sufficiently sensitive to light. In addition, a postexposure ~hermal aftertreatment is necessary in many cases. For this reason none of the systems described have become established in practice.
Attempts have therefore been made to utilize the high light-sensitivity of photopolymerizable layers for the production of positive-working layers by forming an inhibitor of the polymerization by imagewise exposure through an original and then polymerizing the non-inhibited areas in a second, not necessarily imagewise ~ ~ 2 ~
- 4 - O.Z. 0050/41047 exposure step. Examples of compounds proposed for the formation of polymerization inhibitors by irra~iation are nitroso dimers (cf. DE-A-25 42 151) or certain o~nitro-aromatics (cf. DE-A-27 10 417 and EP-A-103 197). These systems all require an additional exposure step, so that if anything the total process time is increased compared with other positive systems.
The hitherto most successful attempt at increas~
ing the light sensitivity of positive-working light-sensitive layers has become known as chemical enhance-ment. Here irradiation leads to the formation of a catalyst which in a second, thermal step, catalyzes a reaction which ultimately leads to an increase in the solubility of the photosensitive layer. The catalyst is usually a strong acid which is formed photochemically, for example, from an organic halogen compound, in par-ticular a halogen atom containin~ triazine compound (cf.
for example DE-A-23 06 248), an aromatic nitro compound (cf. for exampl-~ EP-A-78 981), a dia20nium salt or an aromatic iodonium or sulfonium salt (cf. for example DE-A-36 30 677 and US-A-4 491 628). The acid formed is used for splitting acid-labile bonds in the second, thermal step of the procesc. Depending on the acid-labile compound used, this splitting can lead either to the formation of a hydrophilic group from a hydrophobic group (cf. for example DE-A-36 20 677 and US-A-4 491 628) or to a decr ase in the molecular weight. Examples of acid-labile groups suitable for the last case are acetal (cf.
DE-A-23 06 248, EP-A-78 981, EP-A-82 463 and US-A-3 779 778), orthocarboxylic ester (cf. EP-A- 78 981 and EP-A-82 463), enol ather (cf. EP-A-6 627 and EP-A-82 463), silyl ether (cf. DE-A-35 44 165 and EP-A-130 599) or silyl ester groups (cf. EP-A-130 599).
Although these mixtures make it possible to achieve light sensitivities which in the best cases correspond to those of negative-working layers, products which are construc-ted according to the principle of chemical enhancement ~ ~ 2 .~
- 5 - O.Z. 0050/41047 have become important only withi~ the area of resists for fabrication of integrated circuits. In other fields, the additional thermal step required is not acceptable.
- A further type of a positive-working light-sensitive mixture is described in EP-A-106 156. This mixture consists of a polycolldensate having certain groups in the main chain and unsaturated groups at the end of the chain in combination with a photoinitiator.
Groups mentioned for forming the main chain are aromatic hydrocarbon, diaryl ether, cliaryl sulfide, diaryl sulfone, diarylamine, diaryl keltone and diaryl dike~one groups. End groups are alkenyl groups or unsaturated carboxylic acid groups. The cause for the increase in the solubility on irradiation is suspected to be a chain degradation process induced by free radicals. Despite the very high initiator content of typically 25~ by weight, only moderate light sensitivities are achieved.
The Examples show that in most areas there is still a demand for new positive-working light-sensitive mixtures which combine high light-sensitivity and ease of handling, ie. in particular the absence of additional operations.
It is an object of the present invention to develop a positive-working light-sensitive mixture having the properties mentioned and to devise its underlying reaction product.
We have found, surprisingly, that this object is achieved in that the solubility of mixtures of certain carboxyl- and ureido-containing reaction products and ethylanically unsaturated compounds increases on irradia-tion in the presence of compounds from which free radicals are formed on irradiation.
The present invention accordingly provides a ureido- and carbox~ containing reaction product obtained by reacting i) at least one di- or polyisocyanate, with ii) at least one amino compound of the general ~3i~g ~
- 6 -O.Z. 0050/41047 formula ~I) R~HN-R-XH (I) where - R is the divalent radical of a substituted or unsubstituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R' is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl, a derivative thereof or the monovalent radical H [ O~(CH2)n-CHR"--~
where n is from 1 to 3, m is from 1 to 10 and R~
is H or Cl-C4-alkyl, or an isomer thereof, X is O, S or NR"', R"' is hydrogen, alkyl, aryl, aralkyl, h~droxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and/or at least one amino compound of the general formula (II) ~ Rl~
H~ ~ / R3 (II), where R1 and R2 are identical or different and each is the di.valent radical of a substituted or unsub-~tituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R3 is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and iii) at least one anhydride of an at least dibasic carboxylic acid, with or without 35 iv) an organic compound which is different from component ii) and has at least one hydroxyl group or ami.no group, the amino group having at least 2 ~
- 7 - O.Z. 0050/~1~47 one hydrogen on the nitrogen, with the proviso that the total number of ~Co and an-hydride groups in i) and iii) is equal to or less than the number o~ groups in ii) ancl iv) which are reactive -therewith and i~ in the general formula (I) of component ii) X is O at least one compo~nd of component iv) is included.
This ureido- and carboxyl-containing reaction product is suitable for use as a raw material for 1~ radiation-sensitive mixtures. It is especially suitable for making films whose solubility in aqueous solutions increases on irradiation.
In particular embodiments of the present inven-tion, the reaction product according to the present invention is prepared using as component i) a diisocyan-ate, as component ii) one or more hydroxyalkylamines and as component iii) a cyclic carboxylic anhydride.
Suitable components iv) are in particular mono-alcohols and also primary and secondary monoamines.
The present invention also provides three pro-cesses for preparing the reaction products according to the present invention, which comprise either reacting in a first stage one or more di- or polyisocyanates i) with at least one amino compound ii) and optionally at the same time with a compound having at lea~t one hydroxyl group or amino group iv) to give a urea compound which i5 capable of reaction with anhydride groups and which is reacted in a second stage with at least one acid an-hydride iii) to give an acid-functionalized urea com-pound; or reacting in a first stage one or more di- or polyisocyanates i) with at leas~ one amino compound ii) to give an isocyanato-substituted urea compound which is reacted in a second stage with one or more hydroxylamino compounds iv) to give a urea compound which is capable of reaction with ,anhydride groups and which is reacted in a third stage with at lea~t one acid anhydride iii) to give an acid-functionalized urea compound; or reacting in a 3 ~
- 8 - O.Z. 0050/~1047 first stage one or more di- or polyisocyanates i) with one or more compounds having hydroxyl or amino groups iv) to give an i.socyanato-substituted urethane or urea compound which is reacted in a second stage with at least one amino compound ii) to give a urea compound which is capable of reaction with anhydride groups and which is reacted in a third stage with at :least one acid anhydride iii) to give an acid-functionalized urea compound.
The present invention additionally provides radiation-sensi.tive mixtures of (a) a ureido- and carboxyl-containing reaction product, (b) at least one ethylenically monounsaturated or polyunsaturated compound, 5 (c) optionally, a photoinitiator or photoinitiator system, and (d) optionally, further additives and auxiliaries, wherein compon~nt (a) is an ureido- and carboxyl-contain-~0 ing reaction product obtained by reaction of i) at least one di- or polyisocyanate, with ii) at least one amino compound of the general formula (I) R'HN-R-XH (I) where R is the divalent radical of a substituted or .unsub~tituted alkane, arene, ether, polyether, amine, poly2~ine, ester, polyester, amide or poly2~ide, R' is :hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl, a derivative thereof or the monovalent radical H [ O- ~ CH2 ) D~CHR l~m where n. is from 1 to 3, m is from 1 to 10 and R"
is H OX C~-C4-alkyl, or an isomer thereof, X iS OJ S or NR"', R"' is hydrogen, alkyl, aryl, aralkyl, hydroxy-2~2~
- 9 - O.Z. 0050/41047 alkyl, aminoal~yl, mercaptoalkyl or a derivative there~f, and/or ~ at least one amino compound of the general s formula (II) Rl HN NR3 (II), where Rl and R2 are identical or different and each is the divalent radical of a substituted or unsub-stituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R3 is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a dPrivative thereof, and iii) at least one anhydride of an at least dibasic carboxylic acid, with or without 20 iv) an organic compound which is different from component ii) and has at least one hydroxyl group or amino group, the amino group having at least one hydrogen on the nitrogen, with the proviso that the total number of NCO and an-hydride group-; in i~ and iii) is equal to or less than the number of groups in ii) and iv) which are reactive therewith.
The presant invention provides in particular those radiation-sensitive mixtures whose solubility in ~ater or aqueous alkali increases on irradiation.
In these radiation-sensitive mix~ures, the photoinitiator system (c) is preferably benzophenone or derivatives thereof, hexaarylbisimidazole derivatives, or N-alkoxypyridinium salts, or mixtures thereof.
The ethylenically unsaturated compounds (b) are preferably ~ ethylenically unsaturated carbonyl compounds, such as acrylate~ or methacrylates.

2~2~
- 10 - O.Z. 0050/41047 The reaction products according to the present invention ar~ prepared in the known manner of preparing urea or urethane-urea compounds, by addition of the excess NH ancL OH groups of components ii) and optionally iv) to the i~30cyanate compound i), the number of groups in ii) and iv) which are reactive toward isocyanate being from 1.01 to 6, preferably from 1.5 to 4, per isocyanate group. If a compound iv) is adcled, the isocyanate com-pound i) can be reacted with components ii) and iv) either simultaneously or in stages in any desired order.
Thereafter all or some of the remaining groups which are reactive with anhydride- preferably from 1 to 4 of these groups -are reacted with an anhydride group of component iii) in a s~lilarly known manner to give the respective carboxylic acid compounds.
For easier handling of the products, the reaction may conveniently be carried out in inert solvent.
Suitable for this purpose are in particular solvents having a boiling point of below 150C/atmo~pheria pres-sure, such as acetone, methyl ethyl ketone, ethyl ace-tate, butyl acetate, tetrahydrofuran, toluene, trichloro-ethane. Other suitable solvents are the ethylenically unsaturated compounds (b), if they are liquid.
The temperature for the reaction of the isocyan-ate groups is in general within the range from 0 to 100C, preferably from 20 to 70C.
To speed up the reaction it is possible to use catalysts as described for example in Houben-Weyl, Methoden der organischen Chemie, volume XIVt2, p. 60f, Georg Thieme Verlag, Stuttgart (19633 and Ullmann, Encyclopadie der technischen Chemie, volume 19, p. 306 (1981). Preference is given to tin-containing compounds, eg. dibutyltin dilaurate.
In general, the cataly~t is used in an amount of - 35 from 0.001 to 2.5~ by weight, preferably from 0.0~5 to 1.5% by wei~llt, based on the total amount of the reactants.

2~2~
~ O.Z. 0050/41047 To stabilize th~ radiation-sensitive mixtures it is also possible to add from O.OOl to 2% by weight, preferably from 0.005 to l.0% by weight, of polymeriza-tion inhibitors. These are ~he usual compounds used for S inhibiting thermal polymerization, for example compounds of the hydroquinone, the hydroquinone monoalkyl ether, the 2,6-di-t-butylphenol, the N-nitrosamine, the pheno-thiazine or the phosphorous ester type.
The -products thus obtained are subsequently reacted with at least one anhydride compound iv) to give a carboxylic acid compound. For this reaction the groups which are reactive toward anhydride may be used in an equivalent amount or in excess. Preference is given to equivalent ratios of from l : l to 4 : l. To speed up the reaction it is possible to add ca~alysts of the Lewis acid or Lewis base type in antounts of from 0.Ol to 2~ by weight. Preference is given to 4-(N,N-dimethylamino)-pyridine and N-methylLmidazole. ~he reaction can be carried out within the range from 20 to 120C. A solvent may be added if appropriate.
Especially if the reaction was carried out without a solvent the product, which is solid or highly viscous at room temperature, may be diluted before cooling. In addition to the abovementioned solven~s it is also possible after the reaction to use alcoholic diluents such as methanol, ethanol, isopropanol, etc.
There now follow detailed observations concerning the formative components for preparing the reaction products accorcling to the present invention and their use in radiation-sensitive mixtures.
Suitable compounds for the reaction of components i) to iv) are i.or example the following:
A suitable compound for use as isocyanate com-ponent i) is any compound which contains at least two isocyanate groups capable of reaction with alcohols or primary or secondary amines. Particular preference is given to diisocyanatodiphenylmethane, diisocyanatotoluene ~ ~ 2 ~
- 12 - O.Z. 0050/41047 (= toluylene diisocyanate), hexamethylen~ diisocyanate ar.d isophoro~e diisocyanate and also to oligomers thsreof of the isocyanurate and biuret type.
Suitable amino compounds ii) ar~ those of the general formulae R~HN-R-XH (I) (I) and/or (II) " ,R ~
HN / R3 ( I I ) 10 --T~
where, in the general formula (I) R ' HN-R-XH~ ( I ) Ris a divalent radical of a sub~tituted or unsub-stituted alkane, for example of from 2 to 10 carbon atoms, such as -(CH2)p- where p is from 2 to 10, -CH2-C ( CH3 ) -CH2- or -CH ( CH3 ) -CH2-, of an arene, for example phenylene, of a substituted arene, for ex~mple -(CH2)r-C6H3(0H)- where r is from 1 to 6, preferably 2, of an ether, for example -(CH2-CHRIV-O)q-CH2=CHRIv- where q is from 1 to 5, and RIV is H or alkyl of from 1 to 4 carbon atoms, of an amine, for example of from 2 to 20 carbon atoms, eg. -(CH2)3-N(C~3)-(CH2)3-, of a polyamine, for example -(CH2-CH2-NH)o~ where ~
is from 2 to 5, of an e~ter, for ex~nple of from 4 to 20 carbon atoms, eg. -(CH2~2-COO-(CH2)~- where s is f:rom 2 to 6, -CH2-COO-CH2-CH(CH3)-, or of an amide, for example of from 4 to 20 carbon atoms, e g . - ( C H 2 ) 2 - C Q N H - C H 2 - r 3 0 - ( CH2 ) 2-CONH- ( CH2 ) 5-NHOC- ( CH2 ) 2-;
R~is hydrogen, alkyl, for exampl~ of from 1 to 30, preferably from 1 to 10, carbon atoms, eg.
methyl, ethyl, propyl, butyl and isomers thereof, cycloh~exyl, aryl, for example of from 6 to 18 carbon atoms, preferably phenyl, aralkyl, for example of from 7 to 20 carbon atoms, eg. benzyl, l-methyl-3-phenylpropyl, l-phenylethyl, hydroxy-2~23~ ~
- 13 - O.Z. 0050/41047 alkyl, for example of from 2 to 10 carbon atoms, eg. hydroxyethyl, hydroxypropyl, hydroxybutyl, aminoalkyl, for example of from 2 to 10 carbon - atoms, eg. aminoethyl, aminopropyl, dimethyl-aminobutyl, dimethylaminoneopentyl, mercapto-alkyl, for example of from 2 to 10 carbon atoms, eg. mercaptoethyl, or derivatives of these groups - derivatives being in the present case alkyl-, halogen-, nitro-, nitrile-, carboxyl-, ester-, acyl-, OH-, amino-, sulEo- or diazo-substituted groups of the aforementioned kind - or the monovalent radical H~O-(CH2,n-C~R"~ where n is from 1 to 3, m is from 1 to 10 and R" is H or Cl-C4--alkyl, or isomers thereof as obtainable by simple addition or polyaddition of cyclic ethers, eg. ethylene oxide, propylene oxide or tetra-hydrofuran, for example hydroxyethyloxyethyl;
X is O, S or NR"', where R"' is hydrogen, alkyl, for example of from 1 to 10 carbon atoms, eg.
methyl or ethyl, aryl, for example phenyl or naphthyl, aralkyl, for example benzyl or phenyl-ethyl, hydroxyalkyl, aminoalkyl or mercaptoalkyl, with alkyl groups which may each contain from 1 to 10 carbon atoms, or derivatives of these groups of the type mentioned under R'.
Examples of compounds of the general formula R'HN-R-XH are ethylenediamine, butanediamine, neopentanediamine, polyoxypropylenediamines, polyoxyethylenediamine~, N-ethylethylenediamine, diethylenetriamine, monoisopropanolamine. Par-ticular preference is given to ethanolamine, diethanolamine, diisopropanolamine, neopentanol-amine, ethylisopropanolamine, butylethanolamine and 2-mercaptoethylamine.
In the general formula (II) ~ ~ 2 ~
- 14 - O.Z. 0050/41047 ,,,R~
\ R2 / (II) - Rl ancl R2 are identical or different and each is s the divalent radical of a substituted or unsub-stituted alkane, for example of from 2 to 4 carbon atoms, eg. -(CHz) t- where t is from 1 to ~, of an arene, for example o-phenylene, or an ether, for example of from 2 to 4 carbon atoms, eg. -CH2-O-CH2-, R3 is a hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl" aminoalkyl, mercaptoalkyl or a derivative thereof of the type mentioned under R'. Preferred compo~lnds of the general formula (II) are piper-azine and 1-~2-hydroxyethyl)piperazine.
~Lmilairly, it is also possible to use mixtures of the amino compounds mentioned under ii).
Suitable acid anhydrides iii) are the anhydrides of all compounds which contain at least two carboxylic acid groups. Particular preference is given to cyclic carboxylic anhydrides, eg. phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride and the anhydride of benzophenonetetracarboxylic acid.
The optional compounds which are differen~ from component ii) and have at least one hydroxyl group or amino group, the amino group having at least one hydrogen on the nitrogen, may be any alcohols and primary and secondary amines which are different from ii). Preference is given to using monofunctional alcohols or amines of alkanes of from l to 6 carbon atoms. It is also possible to use polyal~ohols.
The compounds i) to iv) used for preparing the reaction product according to the present invention are adapted to one another in such a way that the resulting mixtures accorcling to the pre~ent invention are insoluble in water or aqueou3 alkali. rhe reaction products accord-ing to the pre~ent invention can have acid numbers up to ~23~
- 15 - O.Z~ 0050/41047 300, prefera~bly from 10 to 200, mg of KO~/g. The molecular weight is advantageously chos~n in such a way as to produce good film forming properties.
(b~ Suitable ethylenically monounsaturated or polyunsaturated compounds are low molecular weight o~
oligomeric compounds having at least one ethylenic double bond. ~h2 compounds are selected for compatibility with the urea compound (a) according to the present invention.
Preference is given to ~ unsatu~ated carbonyl compounds, eg" acrylates and methac~rlates. The ethyleni-cally unsaturated compounds (b) are preferably present in the radiation--sensitive mixtures according to the present invention in an amount of from 3.1 to 40%, particularly preferably from 5 to 40%, based on the total weight of the radiation-sensitive mixture.
(c) The photoinitiators which may be included in the radiation-sensitive mixture according to the present invention are the photoinitiators and photoinitiator systems which are customary and known per se for lightsensitive photopolymerizable recording materials.
Specific examples are: benzoin, benzoin ethers, in particular benzoin alk~rl ethers, substituted benzoins, alk~rl ethers of substituted benzoins, eg. ~-methyl-benzoin alk~rl ethers, or hydroxymethylbenzoin alkyl ethers; benzils, benzil ketals, in particular benzil dimethyl ketal, benzil methyl ethyl ketal or benzil methyl benzyl ketal; the acylphosphine oxide compounds known for use as e~fective photoinitiators, eg. 2,4,6-trimethylbenzoyldiarylphosphine oxide; benzophenone, derivative~ of benzophenone, 4,4'-dimethylaminobenzo-phenone, derivatives of Michler~s ketone; anthraquinone and substituted anthraquinones; aryl-substituted imidazoles or derivatives thereof, eg. 2,4,5-tri-ar~rlimidazole dimers; thioxanthone derivatives, the active photoinitiator acridine or phenacine derivatives and N- alkoxyp~rridinium salts and derivatives thereo F .
Suitable photoinitiators also include diazonium salts, - 16 - O.Z. 0050/41047 eg. p-phenylaminobenzenediazonium hexafluorophosphate, iodonium salts, eg. diphenyliodonium tetrafluoroborate, or sulfonium salts, eg. triphenylsulfonium he~a-fluoroarsenate. Examples of initiator systems are com-binations of the aforementioned initiators with sensitiz-ing assistants or activators, i~ particular tertiary amines. Typical examples of such initiator systems are combinations of benzophenone or benzophenone derivatives with tertiary amines, such as triethanolamine or Michler's ketone; or mixtures of 2,4,5-triarylLmidazole dimers and ~ichler's ketone or the leuco bases of tri-phenylmethane dyes. The choice of suitable photo-initiators or photoinitiator systems is known to the skilled worker. Particularly preferred photoinitiators are Michler's ketone, benzophenone, he~aarylbisimidazole dPrivatives and N-alkoxypyridinium salts. It is also very advantageous to use mixtures of said photoinitiators. The photoinitiators or photoinitiator syRtems are in general present in the light-sensitive recording layer in amounts of from 0.1 to 10~ by weight, based on the radiation-sensitive mixture.
Particularly preferred photoinitiators are Michler's ketone, benzophenone, hexaarylbisimidazole derivatives and N-alkoxypyridinium salts. It is also very advantageous to use mixtures of said photoinitiators.
(d) Suitable additives and/or auxiliaries (d) for possible inclusion in the radiation-sensitive mixture according to the present invention include for example dyes and/or pigments, photochromic compounds and systems, sensitometric regulators, plasticizer~, flow control agent~, delusterants, lubricants, ba~ic components and the like. Examples of dyes and/or pigments, which may serve not only as contrast agents but also to reinforce the layer, include inter alia Brilliant Green (C.I. 42 040), Victoria Pure Blue FGA, Victoria Pure Blue 80 (C.I.
42 595), Victoria Blue B (C.I. 44 045), Rhodamine 6 G
(C.I. 45 160), triphenylmethane dyes, naphthalimide dyes 2 ~
- 17 - O.Z. 005~/41047 and 3 -phenyl-7-dimeth~lamino-2,2'-spirodi(2H-l-benzopyran). Photochromic or color change systems which on irradiation with ac~inic li~ht undergo a reversible or irreversible color chan~e without thereby interfering S with the photopolymerization process are for example leuco dyes together with suitable activators. Examples of leuco dyes are the leuco bases oi. triphenylmethane dyes, such as cr~stal violet leuco base and malachite green leuco base, leuco sasic Blue, leuco pararosaniline, leuco Patent Blue A or V; it is also possible to use Rhodamine B base. Sui~able activators ior these photochromic compounds include inter alia organic halogen compounds which eliminate the halogen radicals on irradiation with actinic light or hexaarylbisimidazoles. Suitable color lS change systems are also described in DE-A-38 24 551.
Particularly suitable color change systems are tho~e where the color intensity decreases on irradiation, for example Sudan dyes, polymethine dyes or azo dyes combined with suitable photoinitiators. Suitable sencitometric regulators include compounds such as 9-nitroanthracene, lO,lO'-bisanthrone, phenazinium, phenoxazinium, acridinium or phenothiazinium dyes, in particular com-bined with mild reducing agents, 1,3-dinitrobenzenes and the like. Suitable pla~ticizers are the known and cus-tomary low or high molecular weight esters, such asphthalates or adipates, toluenesulfonamide or tricresyl phosphate. Suitable basic componen~s are additions of amines, in particular tertiary amines, eg. triethylamine or triethanolamine, or alkali metal or alkaline earth metal hydroxides and carbonates. ~he additives and/or assistants are present in the radiation-sensitive mixture in the effective amounts known and customary for these substances. However, their amount should in general not exceed 30% by weight, preferably 20% by weight, based on the radiation sen~itive mixture.
In many cases it has proYed advisable to add to the radiation-sensitive material-~ according to the -2~3~
-- la - O.Z. 0050/410~7 present invention acidic polymers such as partially esterified styr~ne~maleic anhydride copolymers, copoly-mers of styrene, methyl methacrylate, ethyl acryla-te and methacrylic acid or copolymers of methyl methacrylate, ethylhexyl acrylate and acrylic acid or methacrylic acid.
Such acidic polymers are preferably added to the radiation-sensitive mixture in a concentration of 1 - 40%
by weight, particularly preferab:Ly in a conc~ntration of 5 - 30~ by weight, based on the total weight o~ the radiation-sensitive material.
A film or coating can be prepared by dissolving th~ above-described radiation-sensitive mixture in a solvent and then applying the resulting mixture to a permanent or temporary support by casting, with or without a doctor blade, spin coating, roller coating or some other technique.
Suitable solvents are for example aromatic hydrocarbons, low molecular weight ketones, alcohols, ethers, esters and chlorocarbons.
A suitable support for the radiation-sensitive coatings according to the present invention is virtually any material which is customary in printing and in the fabrication of circuit boards for the electronics in-dustry. However, an important condition is that the support be inert, ie. that it should not react with the radiation-sensitive mixture used for preparing the coating.
Suitable support materials are for example steel, aluminum alloys, mechanically, chemically or electro-chemically roughened aluminum, silicon, polyesters and other plastics. The layer thickness here may vary within wide limits. If the radiation-sensitive mixture is used for example as a letterpress or intaglio printing plate, it will typically be within the range from 50 to 500 ~m, if used as a photoresist for the fabrication of printed circuits within the range from 20 to lO0 ~m and if used as a photoresist for structuring semiconductor materials 2~3~g.~
- 19 _ O.Z. 0050/41047 within the range from 0.3 to 5 ~m. If the radiation-sensitive mixture according to the present invention is used as an offset printing plate, the coating will be prepared in such a way as to produce dry layer weights of S from 0.5 to 5 g/sqm.
The radiation-sensitive ~lixtures according to the present invention are advantageous for producing printing plates or resist patterns in a conventional manner. To this end the light-sensitive recording layer - in the case of photoresist films and laMinating materials after lamination to the substrate to be protected - is sub~
jected to imagewise exposure with actinic light, suitable sources of which are the customary ones r such as W
fluorescent tubes, mercury high, medium or low pressure lamps, superactinic fluorescent tubes, pulsed xenon lamps or even W lasers, argon lasers and the like. The wave-length emitted by the light sources should in general be within the range from 230 to 450 nm, preferably within the range from 300 to 420 nm, and be adapted in par-ticular to the characteristic absorption of the photo-initiator present in the photopolymerizable recording layer.
Following imagewise exposure, the printing plate or resist pattern is developed by washing out the irra-diated areas of the recording layer with water or prefer-ably an aqueous alkali. The process of development can take the form of wa~hing, spraying, rubbing, brushing etc. The recording elements according to the present invention here show a wide exposure latitude and a very low overwash sensitivity. Suitable developers are aqueous alkalis which to set the best pH, in general pH 8-14, preferably a pH within the range from 9 to 13, contain alkaline substances, for example borax, disodium hyd-rogenphosphate, sodium carbonate, al~ali metal hydroxides or organic bases, such as di- or triethanolamine, dis-solved in water. The aqueous alkali developers may also contain buffer salts, for example water-soluble alkali ~23~
- 20 - O.Z. 0~50/41047 metal phosphates, silicates, borates, acetates or benzo-ates. Further suitable constituents of developers are wetting agents, preferably anionic wetting agents, and possibly water-soluble polymers, for example sodium carboxymethylcellulose, polyvinyl alcohol, polysodium ac 'ate and the like. Although the recording elementq according to the present invention are in general washed out with water or aqueous alkali, it is of course pos-sible in principle, although not strictly necessary, that the developer should also contain a small amount of water-soluble organic solvent, for example an aliphatic alcohol, acetone or tetrahydrofuxan.
The radiation-sensitive mixtures according to the present invention can be structured fer example by high-energy radiation such as electron beams or X-rays, when they show their very high sensitivity to radiation. If used in this way it is generally possible to dispense with the addition of a separate initiator system. If, by contrast, the mixtures according to the present invention are to be structured by visible or W light, as is customary for production of printing plates and photo-resists, it is advisable to add suitable photoinitiators whose spectral sensitivity matches the emitted spectrum of the light source used.
The radiation-sensitive mixtures according to the present invention show very high light sensitivity for positive-working systems, which corresponds to the light sensitivity of commercial negative systems of similar thickness. This high light sensitivity is obtained without any need for additional operations, for example the thermal aftertreatment which is necessary with many other positive systems. Similarly, the developers used correspond to those used for negative-workin~ layers, so that the recording layers according to the present invention are completely compatible with conventional systems. The radiation-sensitive recording layers accord-ing to the present invention are highly suitable for 2 ~ 2 ~
- 21 - O.Z. 0050/~1047 multiple exposures. This makes it possible in many applications to save process steps. Multiple ex~os~rss are not possible with all photopolymerizable systems, including many positive systems, for fundamental reasons.
The radiation-sensitive mixtures according to the present invention also have the interesting property of acting as positive systems for short exposure times but as cross-linXable systems for long exposure times. This effect occurs in particular when the radiation-sensitive mixture contains the ethylenically monounsaturated or poly-unsaturated compounds b) in an amount of > S~ by weight.
This property can be utilized after a first, imagewise exposure step with a short exposure time and after removal of the irradiated areas in a dev~loper for initiating a crosslinking reaction in a second, not necessarily imagewise exposure step using a distinctly longer exposure time. In this way it is possible to improve the mechanical properties, for example of print-ing plates.
The invention is illustrated in more detail by the Examples which follow.
In the method of preparation and in the Examples, the parts and percentages are by weight, unless otherwise stated.
Preparation of the reaction products according to the present invention.
Method of preparation A mixture of 129 g of diisobutylamine (1 mol), 133 g of diisopropanolamine and 112 g of methyl ethyl ketone i~ added dropwi~e at 20-25C, with or without ice cooling, to 222 g of isophorone diisocyanate (1 mol), 148 g of methyl ethyl ketone and 0.1 g of dibutyltin dilaurate in the course of 45 minutes. The temperature is then raised to ~0C, 148 g of phthalic anhydride (1 mol) and 3.1 g of N-methylimidazole are added, and heating is continued at 80''C for a further 6 hours.
Use in radiation-sensitive mixtures 3 ~ ~ ~
- 22 - O.Z. 0050~1047 10 g of the reaction product prepared in accor-dance with the above method of preparation, 2.5 g of butyl acrylate, 700 mg of N-methoxypicolinium tosylate and 15 mg of Michler~s ketone were dissolved in a g of methyl ethyl ketone and cast on to a 23 ~m thick sheet o~
polyethylene terephthalate in such a way that, after drying, the photosensitive layer had a thickness of 40 ~m. The layer was covered for storage with a 30 ~m thick sheet of PE. To test the layer, the sheet of PE was peeled off, the composite of polyethylene terephthalate film and photosensitive layer was laminated with the photosensitive layer next to the copper onto a copper-clad circuit board substrate and irradiated in a Riston~
PC printer at 150 mJ/cmZ. After the polyethylene tere-phthalate film had been peeled off, the layer was developed in a spray washer with 1~ strength sodium carbonate solution at 30C for 30 seconds, the exposed areas of the light-sensitive layer proving completely 0 removable. The non-irradiated layers remained unchanged.

As in Example 1, 9 g of the product obtained in accordance with the above method of preparation and 1 g of ethylhexyl acrylate were dissolved in 8 g of methyl ethyl ketone and admixed with 300 mg of benzophenone and 15 mg of Michler's ketone. The solution was used in the same way as in Example l to cast layers 40 ~m in thick-ness. The layers were laminated onto copper-clad cir-cuitboard substrates and irradia~ed in a Riston PC
printer at 100 mJ/cm2. The irradiated areas were removable with 1~ strength sodium carbonate solution in the course of 35 seconds without leaving residues on the copper.

Claims

1. A ureido- and carboxyl-containing reaction product obtained by reacting i) at least one di- or polyisocyanate, with ii) at least one amino compound of the general formula (I) R'HN-R-XH (I) where R is the divalent radical of a substituted or unsubstituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R ' is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl, a derivative thereof or the monovalent radical where n is from 1 to 3, m is from 1 to 10 and R"
is H or C1-C4-alkyl, or an isomer thereof, X is O, S or NR"', R"' is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and/or at least one amino compound of the general formula (II) (II), where R1 and R2 are identical or different and each is the divalent radical of a substituted or unsub-stituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R3 is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and iii) at least one anhydride of an at least dibasic - 24 - O.Z. 0050/41047 carboxylic acid, with or without iv) an organic compound which is different from component ii) and has at least one hydroxyl group or amino group, the amino group having at least one hydrogen on the nitrogen, with the proviso that the total number of NCO and an-hydride groups in i) and iii) is equal to or less than the number of groups in ii) and iv) which are reactive therewith and if in the general formula (I) of component ii) X is O at least one compound of component iv) is included.

2. A reaction product as claimed in claim 1, wherein component iv) is a monoalcohol or a primary or secondary monoamine.

3. A reaction product as claimed in claim 1, wherein componsnt i) is a diisocyanate.

4. A reaction product a claimed in claim 1, wherein component ii) comprises one or more hydroxyalkylamines.

5. A reaction product as claimed in any one of the preceding claims, wherein component iii) is a cyclic carboxylic anhydride.

6. A process for preparing a reaction product as claimed in claim 1, which comprises reacting in a first stage one or more di- or polyisocyanates i) with at least one amino compound ii) and optionally at the same time with a compound having at least one hydroxyl group or amino group ii) to give a urea compound which is capable of reaction with anhydride groups and which is reacted in a second stage with at least one acid anhydride iii) to give an acid-functionalized urea compound.

7. A process for preparing a reaction product as claimed in claim 1, which comprises reacting in a first stage one or more di- or polyisocyanates i) with at least one amino compound ii) to give an isocyanato-substituted urea compound which is reacted in a second stage with one or more hydroxyl or amino compounds iv) to give a urea - 25 - O.Z. 0050/41047 compound which is capable of reaction with anhydride groups and which is reacted in a third stage with at least one acid anhydride iii) to give an acid-function-alized urea or urethane-urea compound.

8. A process for preparing a reaction product as claimed in claim 1, which comprisles reacting in a first stage one or more di- or polyisocyanates i) with one or more compounds having hydroxyl or amino groups iv) to give an isocyanato-substituted urethane or urea compound which is reacted in a second stage with at least one amino compound ii) to give a urea compound which is capable of reaction with anhydride groups and which is reacted in a third stage with at least one acid anhydride iii) to give an acid-functionalized urea compound.

9. A radiation-sensitive mixture of (a) a ureido- and carboxyl-containing reaction product, (b) at least one ethylenically monounsaturatad or polyunsaturated compound, (c) optionally, a photoinitiator or photoinitiator system, and (d) optionally, further additives and auxiliaries, wherein component (a) is an ureido- and carboxyl-contain-ing reaction product obtained by reaction of i) at least one di- or polyisocyanate, with ii) at least one amino compound of the general formula (I) R'HN-R-XH (I) where R is the divalent radical of a substituted or unsubstituted alXane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R' is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl, a derivative thereof or the monovalent radical - 26 - O.Z. 0050/41047 where n is from 1 to 3, m is from 1 to 10 and R"
is H or C1-C4-alkyl, or an isomer thereof, X is O, S or NR"', R"' is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and/or at least one amino compound of the general formula (II) (II), where R1 and R2 are identical or different and each is the divalent radical of a substituted or unsub-stituted alkane, arene, ether, polyether, amine, polyamine, ester, polyester, amide or polyamide, R3 is hydrogen, alkyl, aryl, aralkyl, hydroxy-alkyl, aminoalkyl, mercaptoalkyl or a derivative thereof, and iii) at least one anhydride of an at least dibasic carboxylic acid, with or without iv) an organic compound which is different from component ii) and has at least one hydroxyl group or amino group, the amino group having at least one hydrogen on the nitrogen, with the proviso that the total number of NCO and an-hydride groups in i) and iii) is equal to or less than the number of groups in ii) and iv) which are reactive herewith.

10. A radiation-sensitive mixture as claimed in claim 9, whose solubility in water or aqueous alkali increases on irradiation.

11. A radiation-sensitive mixture as claimed in claim 9 or 10, wherein the photoinitiator system (c) comprises - 27 - O.Z. 0050/41047 benzophenone or a derivative thereof, hexaarylbisimida-zole derivatives, N-alkoxypyridinium salts or mixtures thereof.

12. A radiation-sensitive mixture as claimed in any one of claims 9 to 11, wherein the ethylenically un-saturated compound used is an .alpha.,.beta.-ethylenically unsatur-ated carbonyl compound.

13. A radiation-sensitive mixture as claimed in any one of claims 9 to 12, wherein the ethylenically un-saturated compound used is an acrylate or methacrylate.