CA1170393A - Condensation product and its use - Google Patents
Condensation product and its useInfo
- Publication number
- CA1170393A CA1170393A CA000344837A CA344837A CA1170393A CA 1170393 A CA1170393 A CA 1170393A CA 000344837 A CA000344837 A CA 000344837A CA 344837 A CA344837 A CA 344837A CA 1170393 A CA1170393 A CA 1170393A
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- Canada
- Prior art keywords
- phenol
- condensation product
- component
- substituted
- substituted phenol
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
- C08G8/04—Condensation polymers of aldehydes or ketones with phenols only of aldehydes
- C08G8/08—Condensation polymers of aldehydes or ketones with phenols only of aldehydes of formaldehyde, e.g. of formaldehyde formed in situ
- C08G8/24—Condensation polymers of aldehydes or ketones with phenols only of aldehydes of formaldehyde, e.g. of formaldehyde formed in situ with mixtures of two or more phenols which are not covered by only one of the groups C08G8/10 - C08G8/20
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
- B22C1/2233—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- B22C1/2273—Polyurethanes; Polyisocyanates
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/54—Polycondensates of aldehydes
- C08G18/542—Polycondensates of aldehydes with phenols
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Polymers & Plastics (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Mold Materials And Core Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Polyurethanes Or Polyureas (AREA)
- Phenolic Resins Or Amino Resins (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Condensation product of a phenol component with an aldehyde for polyurethane-based binder systems in which the phenol component is a mixture of an unsubstituted phenol with 15 to 40X by weight, based on the total phenol component. of a p-substituted phenol. A process for making such a condensa-tion product. A molding composition for casting purposes containing such a condensation product as a binder in admixture with foundry sand, a polyisocyanate. and a non-polar solvent, and which is cold-cured with a hardening catalyst.
Condensation product of a phenol component with an aldehyde for polyurethane-based binder systems in which the phenol component is a mixture of an unsubstituted phenol with 15 to 40X by weight, based on the total phenol component. of a p-substituted phenol. A process for making such a condensa-tion product. A molding composition for casting purposes containing such a condensation product as a binder in admixture with foundry sand, a polyisocyanate. and a non-polar solvent, and which is cold-cured with a hardening catalyst.
Description
3~3
-2-Condensation ~roduct and its use In the foundry field increasing importance is attached to binder systems based on polyurethane and which are the reaction product of a cross-linkable, reactive OH group-containing phenol resin and a polyisocyanate which serves as the croEs-linking agent because, as a function of the harden-ing catalyst used they can be cured within ~ery short times (e.gO of less than one minute) at normal ambient temperature and give good strength values. An example for a usable process requiring such binders is the cold box process for the production of foundry moulds and cores. In this process a moulding composition comprising a foundry sand, the phenol resin and the polyisocyanate (both of which are normally dis-solved in an organic solvent) is moulded e.g. by means of an "ejecting machine" and the moulded article is then hardened by subsequent treatment with a tertiary amine which is either gaseous or disper~ed in a carrier gas, which serves as the catalyst. ~owever, polyurethane-based binder systems can also be processed in other ways, For example the proced-ure can be such that the hardening catalyst is added to themoulding composition in the form of a liquid amine before moulding. In addition, hardening catalysts other than amines can be used.
Phenol resins suitable for foundry binder systems having a polyurethane base are substantially anhydrous and must be such that under the action of the hardening catalyst they ca~ rapidly react with the polyisocyanates, lead to good 11';~3~3 initial strengths of the moulded articles and achieve optimum final stren~ths arter the storage Or said articles. Further-more they should have a high linear structure and therefore a low ~iscosity in order to aid the ~low beha~iour Or the mould-ing composition. They must also be as stable as possible in the dissolved state, i.e. their solutions must not have any demixing tendancy. Examples of phenol resins of this type which have been used under practical conditions are deecribed in DAS 1583521~ 1720204 and 1920759. These known phenol resin types are produced by condensing a phenol component with an aldehyde, pre~erably rormaldehyde, condensation being car-ried out in such a way that so-called ~'ben2yl ether-phenol resins`' are obtained. This term is understood to mean phenol resins with a content of terminal methylol groups in which the individual phenol rings are mainly interlinke~ in a linear o-o~ linkage, but optionally also in an o-p linkage and in part via methylene bridges and in part via methylene-ether bridges. The phenol component is the unsubstitute~
phenol or a substituted phenol in ~vhich at least both o-position& are unoccupied.
However, these known phenol resin types fail to com-pletely satisfactorily ~ulfill practical requirements. Thus, although they can be cured e.g. with the moulding compos1tion at ambient temperature, this cannot take place sufficiently rapidly whilst gi~ing adequate initial strengths at lower temperatures and certainly not at the not inrrequently occur-ring temperatures down to 0 C or lower. However, the decisive disad~antage o~ the known phenol resin tyes is that 1 1~1 !393 they cannot be dissolved in non-polar solvents and instead require polar solvents. However, as polyiso-syanates have a poor compatibility with polar solvents, but a good compatibility with non-polar and preferably aromatic solvents a mixture of non-polar and polar solvents must be used as a compromise for the moulding composition. This leads to a relatively short pro-cessing time of the moulding composition (this is the "life" during which-a completely mixed moulding com-position remains storable and can be processed to moulded articles having an adequate strength) obviously because cross-linking reactions are initiated by the proportion of polar solvents. In addition, many of the readily available polar solvents such as e.g.
isophGrone or ethyl-isoamylketone have a very intense smell or are even toxic, whilst attention must also be paid to the compatibility of the solvent mixture constituents, which greatly reduces the selection of possible solvents.
The object of the present invention is to provide a phenol re in intended for polyurethane-based binder systems which fulfills the practical require-ments of the foundry art in that it can be used at lower temperatures of down to 0C., and lower in exactly the same way as at ambient temperature, - ~a 11 70393 whilst leading to moulding compositions having a very long processing time at all temperatures.
The invention achieves this object by a novel condensation product of a phenol component with an aldehyde, which product differs basically from all known phenol resin type.s developed for the coldbox process or similar processes with regard to its struc-ture, to its way of use and also to it~s method of production.
Regarding the structure, the invention is characterised in that the phenol component is a mixture of an unsubstituted phenol with 15 to 40YO by weight, based on the total phenol component, of a p-substituted phenol.
The structural difference to the known phenol resin types, thus, lies in the phenol component con-tained therein. Whereas the known types either use the unsubstituted phenol or a substituted phenol (including also p-substituted phenols), thus using in all cases a homogeneous phenol component it is a prerequisite for the invention that the phenol com-ponent is a mixture of unsubstituted phenol and a p-substituted phenol. As a result of this p-substituted phenol content a reinforced low viscosity linear resin structure is obtained which can be considered as cocausal for the improvement of the processing ~.
,,. . ~
~ 5 ~ ~ <~3 characteristics of the binder. It is particularly surprising that this effect only occurs within the above-indicated limit values for the p-substituted phenol content, i.e. does not occur in linear manner to the mixing ratio.
The substituents of the p-substituted phenol do not have a marked influence on the sought charac-teristics of the binder according to the invention.
However, in the case of a higher molecular weight of the substituent the binder viscosity is somewhat higher, so that it can then be advantageous to use p-substituted phenol contents oriented more towards the upper limit value. As substituents consideration is preferably given to straight or branched alkyl groups, but alkylene groups, aryl groups or other cyclic groups and a1so alkyloxy groups, aryloxy groups, halogen groups, nitro groups, acid groups, ester groups and the like can be used, provided that they do not impair the condensation reaction. Typical examples which are also advantageous from the cost standpoint are p-cresol, p-tert-butylphenol, p-octylphenol, p-nonylphenol, p-(ethylcyclohexyl)-phenol, p-cyclohexylphenol, etc.
The binder according to the invention can be combined with all conventional known polyiso-- 5a - 11~ 3 cyanates of the foundry art and requires a tertiary amine or some other hardening catalyst which catalyzes urethane formation. When processing, e.g. in the cold-box process it hardens in the necessary very short time and gives the same strength values as can be obtained with the known phenol resin types on immediate processing. It cannot be cured by acids or in heat.
Its very good reactivity with polyisocyanates is scarcely temperature-dependent and is fully retained even at low temperatures of the moulding composition (down to below 0C.). This is an important advantage of the invention.
Regarding the way of use, the invention is characterised in that the condensation product is used as a binder for a moulding composition for casting purposes containing as further components foundry sand, polyisocyanates and non-polar solvents and which is cold-cured with a hardening catalyst.
The use-relative difference to the known phenol resin types, thus, lies there in that it is possible with the binder according to the invention to produce moulding compositions using only non-polar solvents, i.e. polar solvents can and must in fact be avoided because they impair the result obtained with the invention. Preference is given to those non-polar aromatic solvents which are also preferred .
solvents for polyisocyanates, i.e. high-boiling aromatic hydrocarbons with a boiling range of 150 to 250C. However, it is also possible to use or add non-aromatic, non-polar solvents such as terpene and similar cycloaliphatic substances and optionally also aliphatic hydrocarbons. In all cases the binder solutions have an excellent stability at all tempera-tures.
As a result of the use of only non-polar solvents, which is not possible with any of the hitherto known phenol resin types developed for poly-urethane systems and which is a decisive advantage of the invention, a high stability, combatible system of all the components is obtained in the moulding com-position mixture. Furthermore the processing time of the finished moulding composition is increased to values which could not hitherto be obtained. This is a direct consequence of the fact that no polar solvent is present which can initiate or aid cross-linking reactions in the moulding composition.
In addition, non-polar aromatic solvents are so hydrophobic that the finished moulding composition only has a very low moisture sensitivity which also contributes to the stability.
In addition, the absence of polar solvents also reduces the tendancy of the moulding composition to become tacky, because the interaction with the core and moulding box surface made e.g. from wood, plastic or metal is reduced.
me greatly increased stability of the system containing the binder according to the invention is also clear from its behaviour during silanisation.
It is conventional practice to add a small quantity of silane (about 1% by weight, which increases with the polarity of the solvent used) to cold box binders in order-to increase the system stability and con-sequently obtain higher strength values. In the known phenol resin types silanisation leads to a marked increase in strength, whilst with the binder according to the invention it only has an insignificant action.
Therefore a system containing the binder according to the invention is already so stable that it scarcely requires silanisation.
Due to the low resin viscosity in con-junction with the use of non-polar solvents moulding compositions produced with the binder according to the invention have an excellent flow and discharge behaviour which has a particularly advantageous effect with complicated moulds and cores. Here again the binder according to the invention is superior to known binders.
Regarding the method of production, the invention is characterised in that the molar ratio of phenol to aldehyde tbased on the total phenol compo-nent~ is adjusted to the range 1:1 to 1:1.5, that the condensation reaction starts in a water-containing medium at temperatures up to 100C., and is sub-sequently terminated at temperatures up to about 125C., accompanied by a slow separation of the water and that the condensation catalyst is used in quantities of 0,01 to 0,1% by weight, based on the total phenol component.
The productional difference to the known phenol resin types, thus, lies therein, that the con-densation reaction substantially is performed in a water-containing medium with a less amount of aldehyde, and that also the amount of condensation catalyst is considerably less. For the production of the known phenol resin types for the coldbox process, namely, phenol and formaldehyde are reacted in a molar ratio of more than 1:1.5 in the presence of about 1 to 2%
by weight of a metal salt of a higher carboxylic acid (e.g. zinc naphthenate or lead neododecanoate) as the condensation catalyst at temperatures of up '~,,~
to about 130C., and indeed under practically water-free conditions, in that the formed reaction water is continuously separated. Although this may be advantageous or necessary for the special linkage of the phenol rings sought in the case of known coldbox binders, it leads to a relatively high residual con-tent of free phenol and free formaldehyde in the binder.
As opposed to thus, the method of the invention leads to the advantage that the phenol component of the present binder (comprising the unsubstututed phenol and the p-substituted phenol) leads to a better reaction with the aldehyde (normally formaldehyde~ during the condensation reaction, so that both the free phenol content and the free formaldehyde content are lower than usual in the resin.
As a result when preparing and processing moulding compositions the smell caused by the phenol and the formaldehyde, together with the disadvantageous action on the environment are reduced to a minimum which is particularly advantageous because at the same time there is no unpleasant smell due to the use of polar solvents. Moreover, the method of the invention also leads to the further advantage that for the pro-~;~
perties of the inventive binder, and especially for the strength, optimally fabourable values are obtained.
The condensation catalysts in the method of the invention can be the known catalysts, namely metal salts of higher carboxylic acids, particularly fatty acids which are soluble in organic solvents and specifically with Mn, Co, Zn, Pb, Sn and the like as metals. However, these catalysts are used in a much smaller quantity of only 0.01 to 0.1% by weight and preferably 0.02 to 0.06% by weight. It has surprisingly been found that a higher catalyst quantity no longer leads to usable results.
~ . ~
'3~;~
Hereina~ter the invention is explained by means of examples. Firstly the preparation of the binder and its processing in application to the coldbox process are des-cribed, followed by the results obtained with testpieces according to the invention and according to the prior art.
A Preparin~ the binder 8.8 mol OI~ a phenol component (in the form of a mizture of 91 ,0 liquified phenol and a p-substituted phenol), 13.0 mol o~ formaldehyde (as paraformaldehyde) and 0.01 to 0.1 % by ~eight, based on the phenol component of zinc octo-ate as the condensation catalyst are placed in a glass appara-tus with a volume of 2 litres and provided with an internal thermometer, stirrer and condenser. The mixture was kept at 95 C for 60 to 1&0 minutes, a clear solution being obtained. By starting in a water-containing medium the formaldehyde is bonded as hydrate and kept in the reaction s~stem.
The uater was then distilled from the reaction sys-tem and the temper~ture raised to 115 C. After standing fo~ 60 minutes at 115 C the temperature was increased to i25 G, accompanied by simultaneous distillation. This was ~ollovled by a boiling period of approx. 60 to 180 minutes at 11~ C until a viscosity of 100 poise (20 C) was obtained.
This was ~olloYIed by vacuum distillation to a product temp-erature OL 120 C. The mixture was cooled and mixed with the solvent as soon as no further distil]ate waS obtained.
rlhen using only aromatic hydrocarbons (boilin~
11~ ~3~33 "
range 160 to 180 C; 50 to 55 ~ resin and 50 to 45 % solvent) stable, clear resin soluti~ns were obtained with a viscosity of 0.2 to o.6 poise (20 C), whilst the viscosities were higher on adding polar solvents. The yields were approx.
70 to 80 %, based on the raw material used.
The free phenol content of the resin was max.4.5 ~0, which is much lower than that of the hitherto conventional free phenol content of 6 to 9 %. The resin no longer had to be designated as a "toxic product". The free formal-dehyde content of the resin i~ also much lower than hitherto.When processing the resin measurements performed on the edge o~ the mixer-gave a value of 1 to 2 ppm, compared witht~e hitherto conventional values o~ 5 to 25 ppm. There~ore the resin is not prejudicial to the environment.
B. Processin~ the binder in the coldboæ Process 100 parts by weight of foundry sand H32, 1 part by weight of the resin solution obtairled according to A and 1 part by weight of a polyisocyanate solution (comprising 85 %
industrial polyisocyanate based on diphenyl-methane-diisocyan-ate and 15 % aromatic hydrocarbons with a boilin range o~ ~60to 180 C), optionally accompanied by the addition of a silane were mixed together to give a moulding composition, whereby firstly the resin solution and then the polyisocyanate sol-ution was added to the sand.
Thi~ mol~ding composition Yas moulde~ to moulding articles either immediately or a~ter a predetermined proces-sing time (i.e. after storing in the mixed, but still not 1.~ 35~;~
cured state), followed by curing by "gasing" with a tertiary amine. The strength characteristics of the cured moulded articles were then determined.
C. Characteristics of the moulded articles obtained The characteristics of the cured moulded articles, together with the necessary individual data are given in the attached tables.
Table 1 illustrates by means of a binder covered by the range of the invention, the good strength values which can be obtained and in particular that the good strength values are maintained even with long processing periods. After a 180 minute processing time e.g. the ~inal strengths (7 day values) have only dropped by 23 %. However, in the case of the known phenol resin types after this or even shorter processing times the strength values have generally reached the low values ~hich only occur after about 300 minutes with the binder used as a basis in Table 1.
Table 2 uses the same binder as Table 1 and illu-strates the influence of the processing temperatures. The table shovJs that the characteristics of the moulded article formed are substantially independent of the processin~ temp-eratures not only in the case of immediate processing, but also after a processing time of 60 minutes.
Using the same binder Table 3 shows the influence of different solvents (including polar solvents not in accord-ance with the invention), ~r~hilst Table 4 shows the influence of adding silane. These Tables show that the strengths 1 ~ 3 (particularly the 7 day values) are lower both in the case of immediate processing and with a processing time of 60 minutes if the solvent contains a proportion of a polar component and that a silane addition has a much smaller action in the case of the non-polar solvents according to the invention than with solvents containing a polar component.
Finally Table 5 shows the limit values for the p-substituted phenol content of the binder and ror the con-densation catalyst quantity used. In the case of 10 %
p-substituted phenol contents (not according to the invention) although good strengths and still usable processing times are obtained the resin solutions are no longer stable at temper-atures below 20 C. Conversely with contents of 49 % of p-substituted phenol (also not according to the invention) the strength values and procesaing times drop. Catalyst quantities in excess of 0.10 ~0 (no longer according to the invention) lea to undesirably high viscosity values and unsatisfactory strength characteristics.
Binder prepared as under A with as the phenol com-ponent 23 ~ by weight of p-tert-butylphenol and the residue unsubstituted phenol, with 0.02 ~0 by weight zinc octoate as the condensation catalyst and 55 % resin and 45 % aromatic hydrocarbons of boiling range 160 to 180 C as the resin solution.
Processing ie as defined under B with a temperature of 25 C and no silane addition, The bending strengths are gi~en in ~/cm'.
Testin,~ the cured moulded articles Processing of Imr,~ed-mouldin~ com~osition iately 4~ min 24 h 48 h 7 d Immediately 235 490 519 530 510 A~ter 60 min 226 471 550 519 510 Af'ter 120 min 206 422 481 451 451 Af'ter 180 min 167 343 402 392 392 A~ter 240 min 127 245 304 304 304 After 300 min 88 206 235 216 235 Table 2 3inder as in Table 1 but the resin solution com-prises 50 % resin ~nd 50 ~0 aromatic hydrocarbons o~ boiling range 160 to 180 CO
The processing is as in Table 1, but with the ~ollowing temperatuIIes :
Range I : Sand 20 to 22 C
Mixture 23 to 25 C
Chamber 19 to 22 C
Range II : Sand 2 to 3 C
Mixture 8 to 10 C
Ghamber 1 to 5 C
3ending stren~ths in ~/cm2.
Testin~ the cured moulded articles Processing of Immed-mouldin~ com~osition iately 45 min 24 h 7 d Immediately rOr range I 205 54 648 677 After 60 min for range I 206 49 598 628 Immediately for range II 196 451 549 549 After 60 min for range II 196 343 441 441 Table ~
3inder as given in Table 1 but the resin solution consists of 50 % resin and 50 % s~lvent..
The solvent comprises aromatic hydrocarbons with boiling range 160 to 180 C, either pure or with the rurther solvent contents given in the Table, Processing is as in Table 1. The bending strengths are given in ~/cm2.
~ ~.`,0~!33 Solvent lli~ture immediately ~rixture stored for processed 60 min Testin~ the cured mouided articles Aromatics 45 244S 45 24 48 with imm. min minmin 7d imm.. min min min 7d No addition 215 490 549 - 538 216 412 540 - 598 20 ~ acetal-dehyde-diethyl-acetate 226 441 490 - 549 226 412 490 - 500 20 0:70 dibutyl sebacate 235 480 490480 441 235 480 510 480 412 20 ~0 n-hexyl-acetate 216 462 412382 363 216 432 373 382 333 20 ~ iso-phorone 166 392 333323 323 177 382 402 382 304 10 % ethyl acetate 196 462 471 - 559 206 402 470 - 530 20 % DL-limonene (terpene) 206 471 677 - 755 235 500 687 - 775 40 ~0 D~-limonene (terpene) 1 96 51 0 627 - 755 245 530 647 - 755 50 'Jt DL-limonene (terpene) 21 6 500 678 - 755 265 530 657 - 765 Table 4 Binder as given in Table 3, but the resin solution comprises 55 % resin and 45 ~0 solvent.
Processin~ is as in Table 1, but either with 0.3 ~O
by ;~eight silane addition (S) or without silane addition (0).
The bending strengths are given in N/cm2.
1~ 3-~3 l ~
Solvent Mixture immediately Mixture stored for processed 60 min Testin~ the cured moulded articles Aromatics 45 24 48 45 24 48 with imm. min min min 7d imm. min min min 7d No addition S 285 539 638 647 667 275 480 569588 657 11 ~ n-hexylacetate S 245 500 451441 441 225 441 422422 402 22 % n-hexylacetate S 216 461 412382 363 216 432 373382 353 33 % iso-phorone S 206 480 343343 333 186 441 363333 304 33 % DL-limonen (terpene) S 285 520 647696 735 343 549 628677 735 66 % DL-limonen (terpene) S 294 579 638667 708 265 500 637657 706 lO No addition 0 285 490 53 ~ 569 255 461 53 ~ 529 33 % dibutyl sebacate 0 275 432 382 - 275 255 422 422 - 304 ; 33 % iso-phorone 0 196 432 225186 147 176 363 245176 137 Table 5 Binder as in Table 1, but the phenol component has a different p-substituted phenol content as given belo~ and the condensation catalyst has a di~ferent zinc octoate quantity given belo1.q.
Processing is as in Table 1 and the bending strengths are giv~n in N/cm2.
`` 11703~33 ~estpiece Catalys~ p-sub- Viscosity Testing of cured _no. % stituted (~oise) moulded articles phenol jO Immed-iately 24~ 48h 0.01 1 0 0.2798 491 520 2 0.02 10 0051 186 579 589
Phenol resins suitable for foundry binder systems having a polyurethane base are substantially anhydrous and must be such that under the action of the hardening catalyst they ca~ rapidly react with the polyisocyanates, lead to good 11';~3~3 initial strengths of the moulded articles and achieve optimum final stren~ths arter the storage Or said articles. Further-more they should have a high linear structure and therefore a low ~iscosity in order to aid the ~low beha~iour Or the mould-ing composition. They must also be as stable as possible in the dissolved state, i.e. their solutions must not have any demixing tendancy. Examples of phenol resins of this type which have been used under practical conditions are deecribed in DAS 1583521~ 1720204 and 1920759. These known phenol resin types are produced by condensing a phenol component with an aldehyde, pre~erably rormaldehyde, condensation being car-ried out in such a way that so-called ~'ben2yl ether-phenol resins`' are obtained. This term is understood to mean phenol resins with a content of terminal methylol groups in which the individual phenol rings are mainly interlinke~ in a linear o-o~ linkage, but optionally also in an o-p linkage and in part via methylene bridges and in part via methylene-ether bridges. The phenol component is the unsubstitute~
phenol or a substituted phenol in ~vhich at least both o-position& are unoccupied.
However, these known phenol resin types fail to com-pletely satisfactorily ~ulfill practical requirements. Thus, although they can be cured e.g. with the moulding compos1tion at ambient temperature, this cannot take place sufficiently rapidly whilst gi~ing adequate initial strengths at lower temperatures and certainly not at the not inrrequently occur-ring temperatures down to 0 C or lower. However, the decisive disad~antage o~ the known phenol resin tyes is that 1 1~1 !393 they cannot be dissolved in non-polar solvents and instead require polar solvents. However, as polyiso-syanates have a poor compatibility with polar solvents, but a good compatibility with non-polar and preferably aromatic solvents a mixture of non-polar and polar solvents must be used as a compromise for the moulding composition. This leads to a relatively short pro-cessing time of the moulding composition (this is the "life" during which-a completely mixed moulding com-position remains storable and can be processed to moulded articles having an adequate strength) obviously because cross-linking reactions are initiated by the proportion of polar solvents. In addition, many of the readily available polar solvents such as e.g.
isophGrone or ethyl-isoamylketone have a very intense smell or are even toxic, whilst attention must also be paid to the compatibility of the solvent mixture constituents, which greatly reduces the selection of possible solvents.
The object of the present invention is to provide a phenol re in intended for polyurethane-based binder systems which fulfills the practical require-ments of the foundry art in that it can be used at lower temperatures of down to 0C., and lower in exactly the same way as at ambient temperature, - ~a 11 70393 whilst leading to moulding compositions having a very long processing time at all temperatures.
The invention achieves this object by a novel condensation product of a phenol component with an aldehyde, which product differs basically from all known phenol resin type.s developed for the coldbox process or similar processes with regard to its struc-ture, to its way of use and also to it~s method of production.
Regarding the structure, the invention is characterised in that the phenol component is a mixture of an unsubstituted phenol with 15 to 40YO by weight, based on the total phenol component, of a p-substituted phenol.
The structural difference to the known phenol resin types, thus, lies in the phenol component con-tained therein. Whereas the known types either use the unsubstituted phenol or a substituted phenol (including also p-substituted phenols), thus using in all cases a homogeneous phenol component it is a prerequisite for the invention that the phenol com-ponent is a mixture of unsubstituted phenol and a p-substituted phenol. As a result of this p-substituted phenol content a reinforced low viscosity linear resin structure is obtained which can be considered as cocausal for the improvement of the processing ~.
,,. . ~
~ 5 ~ ~ <~3 characteristics of the binder. It is particularly surprising that this effect only occurs within the above-indicated limit values for the p-substituted phenol content, i.e. does not occur in linear manner to the mixing ratio.
The substituents of the p-substituted phenol do not have a marked influence on the sought charac-teristics of the binder according to the invention.
However, in the case of a higher molecular weight of the substituent the binder viscosity is somewhat higher, so that it can then be advantageous to use p-substituted phenol contents oriented more towards the upper limit value. As substituents consideration is preferably given to straight or branched alkyl groups, but alkylene groups, aryl groups or other cyclic groups and a1so alkyloxy groups, aryloxy groups, halogen groups, nitro groups, acid groups, ester groups and the like can be used, provided that they do not impair the condensation reaction. Typical examples which are also advantageous from the cost standpoint are p-cresol, p-tert-butylphenol, p-octylphenol, p-nonylphenol, p-(ethylcyclohexyl)-phenol, p-cyclohexylphenol, etc.
The binder according to the invention can be combined with all conventional known polyiso-- 5a - 11~ 3 cyanates of the foundry art and requires a tertiary amine or some other hardening catalyst which catalyzes urethane formation. When processing, e.g. in the cold-box process it hardens in the necessary very short time and gives the same strength values as can be obtained with the known phenol resin types on immediate processing. It cannot be cured by acids or in heat.
Its very good reactivity with polyisocyanates is scarcely temperature-dependent and is fully retained even at low temperatures of the moulding composition (down to below 0C.). This is an important advantage of the invention.
Regarding the way of use, the invention is characterised in that the condensation product is used as a binder for a moulding composition for casting purposes containing as further components foundry sand, polyisocyanates and non-polar solvents and which is cold-cured with a hardening catalyst.
The use-relative difference to the known phenol resin types, thus, lies there in that it is possible with the binder according to the invention to produce moulding compositions using only non-polar solvents, i.e. polar solvents can and must in fact be avoided because they impair the result obtained with the invention. Preference is given to those non-polar aromatic solvents which are also preferred .
solvents for polyisocyanates, i.e. high-boiling aromatic hydrocarbons with a boiling range of 150 to 250C. However, it is also possible to use or add non-aromatic, non-polar solvents such as terpene and similar cycloaliphatic substances and optionally also aliphatic hydrocarbons. In all cases the binder solutions have an excellent stability at all tempera-tures.
As a result of the use of only non-polar solvents, which is not possible with any of the hitherto known phenol resin types developed for poly-urethane systems and which is a decisive advantage of the invention, a high stability, combatible system of all the components is obtained in the moulding com-position mixture. Furthermore the processing time of the finished moulding composition is increased to values which could not hitherto be obtained. This is a direct consequence of the fact that no polar solvent is present which can initiate or aid cross-linking reactions in the moulding composition.
In addition, non-polar aromatic solvents are so hydrophobic that the finished moulding composition only has a very low moisture sensitivity which also contributes to the stability.
In addition, the absence of polar solvents also reduces the tendancy of the moulding composition to become tacky, because the interaction with the core and moulding box surface made e.g. from wood, plastic or metal is reduced.
me greatly increased stability of the system containing the binder according to the invention is also clear from its behaviour during silanisation.
It is conventional practice to add a small quantity of silane (about 1% by weight, which increases with the polarity of the solvent used) to cold box binders in order-to increase the system stability and con-sequently obtain higher strength values. In the known phenol resin types silanisation leads to a marked increase in strength, whilst with the binder according to the invention it only has an insignificant action.
Therefore a system containing the binder according to the invention is already so stable that it scarcely requires silanisation.
Due to the low resin viscosity in con-junction with the use of non-polar solvents moulding compositions produced with the binder according to the invention have an excellent flow and discharge behaviour which has a particularly advantageous effect with complicated moulds and cores. Here again the binder according to the invention is superior to known binders.
Regarding the method of production, the invention is characterised in that the molar ratio of phenol to aldehyde tbased on the total phenol compo-nent~ is adjusted to the range 1:1 to 1:1.5, that the condensation reaction starts in a water-containing medium at temperatures up to 100C., and is sub-sequently terminated at temperatures up to about 125C., accompanied by a slow separation of the water and that the condensation catalyst is used in quantities of 0,01 to 0,1% by weight, based on the total phenol component.
The productional difference to the known phenol resin types, thus, lies therein, that the con-densation reaction substantially is performed in a water-containing medium with a less amount of aldehyde, and that also the amount of condensation catalyst is considerably less. For the production of the known phenol resin types for the coldbox process, namely, phenol and formaldehyde are reacted in a molar ratio of more than 1:1.5 in the presence of about 1 to 2%
by weight of a metal salt of a higher carboxylic acid (e.g. zinc naphthenate or lead neododecanoate) as the condensation catalyst at temperatures of up '~,,~
to about 130C., and indeed under practically water-free conditions, in that the formed reaction water is continuously separated. Although this may be advantageous or necessary for the special linkage of the phenol rings sought in the case of known coldbox binders, it leads to a relatively high residual con-tent of free phenol and free formaldehyde in the binder.
As opposed to thus, the method of the invention leads to the advantage that the phenol component of the present binder (comprising the unsubstututed phenol and the p-substituted phenol) leads to a better reaction with the aldehyde (normally formaldehyde~ during the condensation reaction, so that both the free phenol content and the free formaldehyde content are lower than usual in the resin.
As a result when preparing and processing moulding compositions the smell caused by the phenol and the formaldehyde, together with the disadvantageous action on the environment are reduced to a minimum which is particularly advantageous because at the same time there is no unpleasant smell due to the use of polar solvents. Moreover, the method of the invention also leads to the further advantage that for the pro-~;~
perties of the inventive binder, and especially for the strength, optimally fabourable values are obtained.
The condensation catalysts in the method of the invention can be the known catalysts, namely metal salts of higher carboxylic acids, particularly fatty acids which are soluble in organic solvents and specifically with Mn, Co, Zn, Pb, Sn and the like as metals. However, these catalysts are used in a much smaller quantity of only 0.01 to 0.1% by weight and preferably 0.02 to 0.06% by weight. It has surprisingly been found that a higher catalyst quantity no longer leads to usable results.
~ . ~
'3~;~
Hereina~ter the invention is explained by means of examples. Firstly the preparation of the binder and its processing in application to the coldbox process are des-cribed, followed by the results obtained with testpieces according to the invention and according to the prior art.
A Preparin~ the binder 8.8 mol OI~ a phenol component (in the form of a mizture of 91 ,0 liquified phenol and a p-substituted phenol), 13.0 mol o~ formaldehyde (as paraformaldehyde) and 0.01 to 0.1 % by ~eight, based on the phenol component of zinc octo-ate as the condensation catalyst are placed in a glass appara-tus with a volume of 2 litres and provided with an internal thermometer, stirrer and condenser. The mixture was kept at 95 C for 60 to 1&0 minutes, a clear solution being obtained. By starting in a water-containing medium the formaldehyde is bonded as hydrate and kept in the reaction s~stem.
The uater was then distilled from the reaction sys-tem and the temper~ture raised to 115 C. After standing fo~ 60 minutes at 115 C the temperature was increased to i25 G, accompanied by simultaneous distillation. This was ~ollovled by a boiling period of approx. 60 to 180 minutes at 11~ C until a viscosity of 100 poise (20 C) was obtained.
This was ~olloYIed by vacuum distillation to a product temp-erature OL 120 C. The mixture was cooled and mixed with the solvent as soon as no further distil]ate waS obtained.
rlhen using only aromatic hydrocarbons (boilin~
11~ ~3~33 "
range 160 to 180 C; 50 to 55 ~ resin and 50 to 45 % solvent) stable, clear resin soluti~ns were obtained with a viscosity of 0.2 to o.6 poise (20 C), whilst the viscosities were higher on adding polar solvents. The yields were approx.
70 to 80 %, based on the raw material used.
The free phenol content of the resin was max.4.5 ~0, which is much lower than that of the hitherto conventional free phenol content of 6 to 9 %. The resin no longer had to be designated as a "toxic product". The free formal-dehyde content of the resin i~ also much lower than hitherto.When processing the resin measurements performed on the edge o~ the mixer-gave a value of 1 to 2 ppm, compared witht~e hitherto conventional values o~ 5 to 25 ppm. There~ore the resin is not prejudicial to the environment.
B. Processin~ the binder in the coldboæ Process 100 parts by weight of foundry sand H32, 1 part by weight of the resin solution obtairled according to A and 1 part by weight of a polyisocyanate solution (comprising 85 %
industrial polyisocyanate based on diphenyl-methane-diisocyan-ate and 15 % aromatic hydrocarbons with a boilin range o~ ~60to 180 C), optionally accompanied by the addition of a silane were mixed together to give a moulding composition, whereby firstly the resin solution and then the polyisocyanate sol-ution was added to the sand.
Thi~ mol~ding composition Yas moulde~ to moulding articles either immediately or a~ter a predetermined proces-sing time (i.e. after storing in the mixed, but still not 1.~ 35~;~
cured state), followed by curing by "gasing" with a tertiary amine. The strength characteristics of the cured moulded articles were then determined.
C. Characteristics of the moulded articles obtained The characteristics of the cured moulded articles, together with the necessary individual data are given in the attached tables.
Table 1 illustrates by means of a binder covered by the range of the invention, the good strength values which can be obtained and in particular that the good strength values are maintained even with long processing periods. After a 180 minute processing time e.g. the ~inal strengths (7 day values) have only dropped by 23 %. However, in the case of the known phenol resin types after this or even shorter processing times the strength values have generally reached the low values ~hich only occur after about 300 minutes with the binder used as a basis in Table 1.
Table 2 uses the same binder as Table 1 and illu-strates the influence of the processing temperatures. The table shovJs that the characteristics of the moulded article formed are substantially independent of the processin~ temp-eratures not only in the case of immediate processing, but also after a processing time of 60 minutes.
Using the same binder Table 3 shows the influence of different solvents (including polar solvents not in accord-ance with the invention), ~r~hilst Table 4 shows the influence of adding silane. These Tables show that the strengths 1 ~ 3 (particularly the 7 day values) are lower both in the case of immediate processing and with a processing time of 60 minutes if the solvent contains a proportion of a polar component and that a silane addition has a much smaller action in the case of the non-polar solvents according to the invention than with solvents containing a polar component.
Finally Table 5 shows the limit values for the p-substituted phenol content of the binder and ror the con-densation catalyst quantity used. In the case of 10 %
p-substituted phenol contents (not according to the invention) although good strengths and still usable processing times are obtained the resin solutions are no longer stable at temper-atures below 20 C. Conversely with contents of 49 % of p-substituted phenol (also not according to the invention) the strength values and procesaing times drop. Catalyst quantities in excess of 0.10 ~0 (no longer according to the invention) lea to undesirably high viscosity values and unsatisfactory strength characteristics.
Binder prepared as under A with as the phenol com-ponent 23 ~ by weight of p-tert-butylphenol and the residue unsubstituted phenol, with 0.02 ~0 by weight zinc octoate as the condensation catalyst and 55 % resin and 45 % aromatic hydrocarbons of boiling range 160 to 180 C as the resin solution.
Processing ie as defined under B with a temperature of 25 C and no silane addition, The bending strengths are gi~en in ~/cm'.
Testin,~ the cured moulded articles Processing of Imr,~ed-mouldin~ com~osition iately 4~ min 24 h 48 h 7 d Immediately 235 490 519 530 510 A~ter 60 min 226 471 550 519 510 Af'ter 120 min 206 422 481 451 451 Af'ter 180 min 167 343 402 392 392 A~ter 240 min 127 245 304 304 304 After 300 min 88 206 235 216 235 Table 2 3inder as in Table 1 but the resin solution com-prises 50 % resin ~nd 50 ~0 aromatic hydrocarbons o~ boiling range 160 to 180 CO
The processing is as in Table 1, but with the ~ollowing temperatuIIes :
Range I : Sand 20 to 22 C
Mixture 23 to 25 C
Chamber 19 to 22 C
Range II : Sand 2 to 3 C
Mixture 8 to 10 C
Ghamber 1 to 5 C
3ending stren~ths in ~/cm2.
Testin~ the cured moulded articles Processing of Immed-mouldin~ com~osition iately 45 min 24 h 7 d Immediately rOr range I 205 54 648 677 After 60 min for range I 206 49 598 628 Immediately for range II 196 451 549 549 After 60 min for range II 196 343 441 441 Table ~
3inder as given in Table 1 but the resin solution consists of 50 % resin and 50 % s~lvent..
The solvent comprises aromatic hydrocarbons with boiling range 160 to 180 C, either pure or with the rurther solvent contents given in the Table, Processing is as in Table 1. The bending strengths are given in ~/cm2.
~ ~.`,0~!33 Solvent lli~ture immediately ~rixture stored for processed 60 min Testin~ the cured mouided articles Aromatics 45 244S 45 24 48 with imm. min minmin 7d imm.. min min min 7d No addition 215 490 549 - 538 216 412 540 - 598 20 ~ acetal-dehyde-diethyl-acetate 226 441 490 - 549 226 412 490 - 500 20 0:70 dibutyl sebacate 235 480 490480 441 235 480 510 480 412 20 ~0 n-hexyl-acetate 216 462 412382 363 216 432 373 382 333 20 ~ iso-phorone 166 392 333323 323 177 382 402 382 304 10 % ethyl acetate 196 462 471 - 559 206 402 470 - 530 20 % DL-limonene (terpene) 206 471 677 - 755 235 500 687 - 775 40 ~0 D~-limonene (terpene) 1 96 51 0 627 - 755 245 530 647 - 755 50 'Jt DL-limonene (terpene) 21 6 500 678 - 755 265 530 657 - 765 Table 4 Binder as given in Table 3, but the resin solution comprises 55 % resin and 45 ~0 solvent.
Processin~ is as in Table 1, but either with 0.3 ~O
by ;~eight silane addition (S) or without silane addition (0).
The bending strengths are given in N/cm2.
1~ 3-~3 l ~
Solvent Mixture immediately Mixture stored for processed 60 min Testin~ the cured moulded articles Aromatics 45 24 48 45 24 48 with imm. min min min 7d imm. min min min 7d No addition S 285 539 638 647 667 275 480 569588 657 11 ~ n-hexylacetate S 245 500 451441 441 225 441 422422 402 22 % n-hexylacetate S 216 461 412382 363 216 432 373382 353 33 % iso-phorone S 206 480 343343 333 186 441 363333 304 33 % DL-limonen (terpene) S 285 520 647696 735 343 549 628677 735 66 % DL-limonen (terpene) S 294 579 638667 708 265 500 637657 706 lO No addition 0 285 490 53 ~ 569 255 461 53 ~ 529 33 % dibutyl sebacate 0 275 432 382 - 275 255 422 422 - 304 ; 33 % iso-phorone 0 196 432 225186 147 176 363 245176 137 Table 5 Binder as in Table 1, but the phenol component has a different p-substituted phenol content as given belo~ and the condensation catalyst has a di~ferent zinc octoate quantity given belo1.q.
Processing is as in Table 1 and the bending strengths are giv~n in N/cm2.
`` 11703~33 ~estpiece Catalys~ p-sub- Viscosity Testing of cured _no. % stituted (~oise) moulded articles phenol jO Immed-iately 24~ 48h 0.01 1 0 0.2798 491 520 2 0.02 10 0051 186 579 589
3 o.o6 10 0.80 226 628 608
4 0.12 1 0 2.2Q255 530 540 0.01 23 0.20t68 598 598 0002 23 0.31206 579 589 7 0.06 23 0.62255 559 569 8 0.12 23 1.52 235 51 0 471 9 0.01 36 00 23 177 540 559 0.02 36 0.30206 530 549 11 oOo6 36 0.3921 6 51 0 51 0 1 2 001 2 36 o.69216 491 471 13 0001 49 0.20167 451 432 14 0.02 49 0024167 451 422 oOo6 49 0.291 86 41 2 392 16 0.12 49 Oo56167 392 373
Claims (18)
1. A condensation product of a phenol component with an aldehyde for polyurethane-based binder systems, characterized in that the phenol component is a mix-ture of an unsubstituted phenol with 15 to 40% by weight, based on the total phenol component, of a p-substituted phenol.
2. A condensation product according to claim 1, wherein said p-substituted phenol is a p-alkyl substituted phenol.
3. A condensation product according to claim 2, wherein the alkyl substituent is a straight chain alkyl.
4. A condensation product according to claim 2, wherein the alkyl substituent is a branched chain alkyl.
5. A condensation product according to claim 1, wherein said p-substituted phenol is p-cresol.
6. A condensation product according to claim 1, wherein said p-substituted phenol is p-tert-butyl-phenol.
7. A condensation product according to claim 1, wherein said p-substituted phenol is p-octylphenol.
8. A condensation product according to claim 1, wherein said p-substituted phenol is p-nonylphenol.
9. A condensation product according to claim 1, wherein said p-substituted phenol is p-(ethylcyclo-hexyl)-phenol.
10. A condensation product according to claim 1, wherein said p-substituted phenol is p-cyclohexyl-phenol.
11. A process for the production of a conden-sation product of a phenol component with an aldehyde for polyurethane-based binder systems comprising:
condensing a phenol component with an aldehyde in the presence of a metal salt of a higher carboxylic acid with a polyvalent metal as the condensation catalyst, said phenol component being a mixture of an unsubstituted phenol with 15 to 40%, by weight, based on the total phenolcomponent, of a p-substituted phenol, the molar ratio of phenol to aldehyde, based on the total phenol component, being adjusted to the range 1:1 to 1:1.5: the condensation reaction being started in a water-containing medium at a temperature up to 100°C and being subsequently terminated at a temperature up to about 125°C., accompanied by a slow separation of the water, the condensation catalyst being used in an amount of 0.01 to 0.1% by weight, based on the total phenol component.
condensing a phenol component with an aldehyde in the presence of a metal salt of a higher carboxylic acid with a polyvalent metal as the condensation catalyst, said phenol component being a mixture of an unsubstituted phenol with 15 to 40%, by weight, based on the total phenolcomponent, of a p-substituted phenol, the molar ratio of phenol to aldehyde, based on the total phenol component, being adjusted to the range 1:1 to 1:1.5: the condensation reaction being started in a water-containing medium at a temperature up to 100°C and being subsequently terminated at a temperature up to about 125°C., accompanied by a slow separation of the water, the condensation catalyst being used in an amount of 0.01 to 0.1% by weight, based on the total phenol component.
12. A process according to claim 11, wherein said catalyst is employed in an amount of 0.02 to 0.06% by weight, based on the total phenol component.
13. A process according to claim 12, wherein said catalyst is a salt of a fatty acid.
14. A process according to claim 13, wherein said metal of said salt is selected from the group consisting of Mn, Co, Zn, Pb and Sn.
15. A process according to claim 11, 12 or 13, wherein said p-substituted phenol is selected from the group consisting of p-cresol, p-tert-butylphenol, p-octylphenol, p-nonylphenol, p-(ethylcyclohexyl)-phenol and p-cyclohexylphenol.
16. A moulding composition for casting purposes, comprising:
a mixture of:
i) a condensation product of a phenol component with an aldehyde for polyurethane-based binder systems, in which the phenol component is a mixture of an unsubstituted phenol with 15 to 40%
by weight, based on the total phenol component, of a p-substituted phenol, ii) foundry sand, iii) a polyisocyanate, and iv) a non-polar solvent, said composition being adapted to be cold-cured with a hardening catalyst.
a mixture of:
i) a condensation product of a phenol component with an aldehyde for polyurethane-based binder systems, in which the phenol component is a mixture of an unsubstituted phenol with 15 to 40%
by weight, based on the total phenol component, of a p-substituted phenol, ii) foundry sand, iii) a polyisocyanate, and iv) a non-polar solvent, said composition being adapted to be cold-cured with a hardening catalyst.
17. A composition according to claim 16, wherein said p-substituted phenol is selected from the group consisting of p-cresol, p-tert-butylphenol, p-octylphenol, p-nonylphenol, p-(ethylcyclohexyl)-phenol and p-cyclohexylphenol.
18. A composition according to claim 16 or 17, wherein said non-polar solvent is an aromatic hydrocarbon with a boiling range of 150 to 250°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2904961A DE2904961C2 (en) | 1979-02-03 | 1979-02-03 | Binders for foundry molding compounds |
| DEP2904961.4 | 1979-02-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170393A true CA1170393A (en) | 1984-07-03 |
Family
ID=6062575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000344837A Expired CA1170393A (en) | 1979-02-03 | 1980-01-31 | Condensation product and its use |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0014855B1 (en) |
| JP (1) | JPS55137121A (en) |
| AT (1) | AT385274B (en) |
| BR (1) | BR8000644A (en) |
| CA (1) | CA1170393A (en) |
| DE (1) | DE2904961C2 (en) |
| ES (1) | ES478882A1 (en) |
| IN (1) | IN152366B (en) |
| IT (1) | IT1124672B (en) |
| MX (1) | MX154448A (en) |
| YU (1) | YU23180A (en) |
| ZA (1) | ZA794570B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5151341A (en) * | 1989-12-12 | 1992-09-29 | Kim Son N | Radiation-sensitive mixture and production of relief structures |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4590229A (en) * | 1984-06-04 | 1986-05-20 | Ashland Oil, Inc. | Phenolic resin-polyisocyanate binder systems |
| JPS61140981A (en) * | 1984-12-12 | 1986-06-28 | シャープ株式会社 | Liquid crystal display panel |
| DE19738755C2 (en) * | 1997-09-04 | 2002-01-17 | Ashland Suedchemie Kernfest | Phenolic resin and binder for the production of molds and cores using the phenolic resin-polyurethane process |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE884869C (en) * | 1949-07-31 | 1953-07-30 | Kurt Herberts & Co Vormals Ott | Process for the production of resins from phenolic alcohols and reactive carbonyl compounds |
| US3227686A (en) * | 1960-09-22 | 1966-01-04 | Continental Can Co | Internally plasticized phenolic resins |
| US3485797A (en) * | 1966-03-14 | 1969-12-23 | Ashland Oil Inc | Phenolic resins containing benzylic ether linkages and unsubstituted para positions |
| DE1770816C3 (en) * | 1968-07-06 | 1973-10-18 | Reichhold-Albert-Chemie Ag, 2000 Hamburg | Process for the production of flexible phenolic resins |
| GB1278582A (en) * | 1968-08-20 | 1972-06-21 | Bp Chem Int Ltd | Phenolic laminating resins |
| US3624038A (en) * | 1970-11-05 | 1971-11-30 | Johnson & Johnson | Phenol formaldehyde resin consisting of an aryl or alkyl substituted phenol-hcho condensate and an alkaline earth metal carboxylate salt of a hydroxy ring substituted aromatic or phenyl substituted aliphatic acid |
| US4048103A (en) * | 1976-02-09 | 1977-09-13 | Minnesota Mining And Manufacturing Company | Composition based on phenolic resin, polyisocyanate, and petroleum oil |
-
1979
- 1979-02-03 DE DE2904961A patent/DE2904961C2/en not_active Expired
- 1979-03-22 ES ES478882A patent/ES478882A1/en not_active Expired
- 1979-08-29 ZA ZA00794570A patent/ZA794570B/en unknown
- 1979-10-26 IT IT26826/79A patent/IT1124672B/en active
-
1980
- 1980-01-21 AT AT0029880A patent/AT385274B/en not_active IP Right Cessation
- 1980-01-24 EP EP80100360A patent/EP0014855B1/en not_active Expired
- 1980-01-29 YU YU00231/80A patent/YU23180A/en unknown
- 1980-01-31 CA CA000344837A patent/CA1170393A/en not_active Expired
- 1980-01-31 MX MX181036A patent/MX154448A/en unknown
- 1980-02-01 BR BR8000644A patent/BR8000644A/en unknown
- 1980-02-04 JP JP1159980A patent/JPS55137121A/en active Pending
- 1980-02-08 IN IN154/CAL/80A patent/IN152366B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5151341A (en) * | 1989-12-12 | 1992-09-29 | Kim Son N | Radiation-sensitive mixture and production of relief structures |
Also Published As
| Publication number | Publication date |
|---|---|
| ES478882A1 (en) | 1979-11-16 |
| BR8000644A (en) | 1980-10-21 |
| DE2904961A1 (en) | 1980-08-07 |
| YU23180A (en) | 1983-09-30 |
| AT385274B (en) | 1988-03-10 |
| ZA794570B (en) | 1980-08-27 |
| IN152366B (en) | 1983-12-31 |
| EP0014855B1 (en) | 1987-01-21 |
| IT1124672B (en) | 1986-05-14 |
| IT7926826A0 (en) | 1979-10-26 |
| MX154448A (en) | 1987-08-27 |
| JPS55137121A (en) | 1980-10-25 |
| DE2904961C2 (en) | 1986-12-11 |
| EP0014855A1 (en) | 1980-09-03 |
| ATA29880A (en) | 1987-08-15 |
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