CA1103392A - Electrolyte-free aminoplast resins and their preparation - Google Patents
Electrolyte-free aminoplast resins and their preparationInfo
- Publication number
- CA1103392A CA1103392A CA270,645A CA270645A CA1103392A CA 1103392 A CA1103392 A CA 1103392A CA 270645 A CA270645 A CA 270645A CA 1103392 A CA1103392 A CA 1103392A
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- CA
- Canada
- Prior art keywords
- etherified
- methylolaminotriazine
- methylol groups
- aminotriazine
- composition
- 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.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/64—Condensation products of melamine with aldehydes; Derivatives thereof
-
- 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
- C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
- C08G12/40—Chemically modified polycondensates
- C08G12/42—Chemically modified polycondensates by etherifying
- C08G12/424—Chemically modified polycondensates by etherifying of polycondensates based on heterocyclic compounds
- C08G12/425—Chemically modified polycondensates by etherifying of polycondensates based on heterocyclic compounds based on triazines
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
- C08L61/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08L61/32—Modified amine-aldehyde condensates
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- General Chemical & Material Sciences (AREA)
- Phenolic Resins Or Amino Resins (AREA)
- Laminated Bodies (AREA)
Abstract
Abstract of the Disclosure Electrolyte-free etherified methylolamino-triazines are directly prepared by reacting together in the absence of electrolyte, the aminotriazine, formaldehyde and certain ether-alcohols. When the formaldehyde to aminotriazine mol ratio is sufficiently high and the etherification sufficiently extensive, the resulting products are particularly desirable in that they are quite stable and thermoset to exception-ally elastic, cured products having high electrical, moisture, and temperature resistance.
Description
ll`~J33g2 The present invention relates to thermosetting etherified methylol-aminotriazines which are substantially free from electrolyte and contain, as a statistical average, 1.3 to (2n) methylol groups per mol of the amino-triazine (n being the number of amino groups in the aminotriazine and usually amounting to 2 or 3) which are etherified to the extent of at least 33% with a glycol derivative of the general formula I:
R-(ocH2cH2)moH (I) wherein R denotes an aIkyl group having 1 to 4 C atoms and m represents an integer from 1 to 4, and which are suitable, with particular advantage, for the manufacture of mouldings, laminates and surface coatings.
It is hlown to manufacture mouldings by pressing combinations of thermosetting aminoplast resins, carrier materials and optionally further additives, such as pigments, flow auxiliaries and slip agents or release agents, at an elevated temperature. Carrier materials which are suitable for this purpose are, in principle, substantially all absorbent inorganic or organic structures. The carrier materials are impregnated with the aminoplast resins in a known manner, for example by application with brushes or rollers, spraying-on or dipping, and dried to the required residual moisture content. The sheet-like combinations thus obtained are laid one on top of another in several layers and are pressed to form mould-ings at elevated temperatures.
The sheet-like combinations of carrier material with aminoplast resins are also suitable for the surface coating of other materials, such as, for example, wood or chipboard. Thus they are used in the furniture industry, for example, for coating sheets of chipboard, hardboard or ply-wood or other wood-based materials. In this application the carrier 3 1~t33~Z
materi~ls, aft~r impregnation -~ith aminoplast resin, are pres~ed onto the wood-based ~aterials under the action o~
heat and pressure usi~g a gluing agent.
furtner known method of manufacturing mouldings by pres-Qing comprises combining aminoplast re~ins with pulverulent ~illers and optionally further known additives, such a~
pigments,~low au~iliaries and o~tionPlly slip agents or relea e agents, and pressing the~e products in mould~ at -elevated temperature.
The properties o~ a moulding ~anufactured by one of the above-mentioned process are de~endent to a large e~tent on the naturs o~ the aminoplast resi~ used. The Pm;noplast res;n~ hitherto known have disadvantages which in some cases considerably limit their applicability for the pur-poses n~icated above. ~hus, for e~ample, the sheets which coul~ be manufactured by Impregnating paper webs or te~tile web~ with the melamine resins hitherto known T~ere insuf~iciently ela~tic for m2~y end uses. Admittedly it wa~ known ~hat the elasticity and hence the bendi~g radiuQ
can be improved if modi~ying agents, such as, for e~ample, glycols, are added to the aminoplast resin. ~he improve-ment in elasticity produced i~ ~his way was, howe~er, associated with a deterioration of the resistance to wæte~, so th~t the sheets could not be u~ed for some end use~, ~or e~ample en~a~ing profiled mouldings. The laminates or wood-based mouldings manufactured by pressing or by impre~-~tir.g p per webs or textile webs or wood veneers with known ainoplast resins also did not exhibit adequate elastieity, above all in cases ~here the ~anu~actured mouldings are to be employed in situations in which they are subjected to an ~lternating e~osure to heat.
~ 1~i`3392 In the construction of electrical apparatus also, the mouldings manufactured with aminoplast resins hitherto known did not exhibit, because of their electrolyte con-tent, the desired properties, such as high electricalresistance and high tracking resistance.
Etheriiied methylolaminotriazines hitherto known have been manufactured by methylolation and simultaneous or sub-sequent etherification oi the methylolaminotriazines in the presence o~ acid catalysts (compare Houben-Weyl, volume 14/2, pages 35~-368; Ullmann Enzyklopadie der technischen Chemie (Ullmann's Encyclopaedia oi Industrial Chemistry), volume 3, pages 487-489). The degree o~
methylolation here, ior example in the case of melamine, is generally 3-6. Aiter the completion oi the reaction, it was necessary to neutralise the acid catalyst employed and to remove the resulting salt by iilteration. This was, however, generally only incompletely acco0plished, so that on storing the products manui'actured in this way an un-desirable turbidity was produced which was due to further precipitation oi the salt and, moreover, the residues of salt which could not be removed let to an extremely sharp decrease in the electrical resistance and the tracking resistance of the mouldi~gs manu~actured with aminoplast resins of this ~ind.
Previously known methylolaminotriazines etheri~ied with long-chain alcohols have hitherto been obtained mainly by trans-etheri~icatio~ oi corresponding methyl ethers under conditions oi acid catalysis.
It has now been iound, surprisingly, that thermosetting etheri~ied methylolaminotriazines which are substantially ~i - 3 _ 11(3;~39Z
free from electrolyte and contain as a statistical average 1.3 to 2 n methylol groups per mol of the aminotriazine (n being the number of amino groups in the aminotriazine) which are etherified to the extent oi at least 33Z with a glycol derivative o~ the general formula I
R-(CH2CH2)mOH (I) wherein R denotes an alkyl group having 1-4 C atoms and m represents an integer ~rom 1 to 4, do not display the dis-advantages of the thermosetting aminoplast resins known hitherto and are there~ore suitable, with particular advan-tage, ior the manufacture of laminates and wood-based mouldings o~ high elasticity and high resistance to water and also electro-technical laminates and compression mould~ngs o~ high tracking resistance.
Examples o~ glycols, oi the general ~ormula I, which can be used ~or the manu~acture o~ the etheriiied methylolamino-triazines to be used ln accordance with the invention, are methylglycol, ethylglycol, diglycol monomethyl ether, digly-col monoethyl ether, digl~col monopropyl ether, triglycol monomethyl ether, triglycol monoethyl ether, triglycol mono-propyl ether, triglycol monobutyl ether, tetraglycol mono-methyl ether, tetraglycol monoethyl ether, tetraglycol monopropyl ether and tetraglycol monobutyl ether. Examples o~ aminotriazines which can be used for the manuiacture oi the etheriiied methylolami~otriazines to be employed in accordance with the invention are melamineS benzoguanami~e and acetoguanamine.
It is preierable to employ those methylaminotriazines which contain as a statistical average 1.8-2 n methylol groups per mol oi the aminotriazine, and especially those which contain 1.8 to 1.2 n methylol groups per mol of the A
115~339Z
aminotriazine. Those methylolaminotriazines in which at least 50~ of the methylol groups are etherified, are also preferred. Amongst the glycols of the general formula I, employed for the etherification, those glycols are preferred in which R denotes a methyl group, and in addition, those in which m represents the number 1 or 2. Glycols of the general ~ormula I which are particularly pre~erred are those in which R denotes a methyl group and m represents the number 1 or 2. A further group of preferred methylolaminotriazines to be used in accordance with the invention are those which are derived ~rom melamine.
It was surprisingly iound that the use of glycol derivatives oi the general formula I
R_(OCH2CH2)mOH (I) ~or the etheri~ication of the methylolaminotriazines ren-ders the use o~ acid catalysts super~luous and that the molar ratio oi aminotriazine to formaldehyde can be varied within considerably wider limits than has hitherto been known in the case o~ normal etheriiied melamine-iormaldehyde condensation products.
Owing to the absence o$ acid catalysts, neu*ralisation of the reaction mixtures is not necessary, so that completely electrolyte-iree products may be obtained.
The freedom ~rom electrolyte is a decisive ~actor in the outstanding electrical properties of the mouldings accord-ing to the invention and the wide range o~ degree of methylolation permits the properties o~ the products accor-ding to the invention to be adjusted even to extreme industrial demands, with special reference to elasticity, resista~ce to water and resistance to heat and changes of temperature.
116~;~3~z The etherified methylolaminotriazines to be employed in accordance with the invention are manufactured by condens-ing an aminotriazine with formaldehyde and with an excess of the glycol derivative of the formula I, 1.3 to 2 n mols of formaldehyde - if n is the number of amino groups in the aminotriazine - being employed per mol of the aminotriazine and the condensation reaction being carried out in the absence of acids and alkalis. The condensation reaction usually takes place at temperatures of 50 to 180C, pre-ferably 80 to 140C. The condensation reaction is con-tinued until the degree of etherification of the reaction product is at least 33 %. The excess of glycol to be employed can be 1.2 to 20 times the theoretical amount.
After the desired degree of condensation has been achieved, the excess of glycol remaining is removed conveniently by distillation, preferably in vacuo. The water of reaction iormed during the condensation reaction is preferably dis-tilled off continuously. The removal of the water of reaction by distillation is also appropriately carried out in vacuo.
Ii the water of reaction is removed continuously by dis-tillation during the reaction, it is possible to determine, from the quantity of the latter, the degree of etherifi-cation of the reaction product which has been achleved.
The formaldehyde ls preferably employed in the form of paraformaldehyde. It is, however, also possible to use aqueous solutions of formaldehyde or solutions of formalde-hyde in the glycol derivatives of the general formula I
which are employed in accordance with the invention for the etherification.
_ _ The manufacture of mouldings by using the etherified methylolaminotriazines according to the invention is carried out by combining the etherified methylolaminotria-zine with a carrier or filler and pressing the resulting compositions under pressure at elevated temperature so as the produce mouldings.
The compositions can be obtained by impregnating, for example, absorbent sheet-like materials, such as, textile webs composed of natural or synthetic ~ibres, especially cellulose fibres; random fibre fleeces, in particular absorbent paper; and wood veneers, with the aminoplast resins of the present invention. The impregnation can be carried out in a known manner, for example by application with brushes or rollers, spraying-on or dipping, the general procedure being such that the impregnated materials contain 25 to 75 %, pre~erably 25 to 50 %, and most pre~erably 30 to 40 % of the aminoplast resin. After impregnation, the materials are dried to a residual moisture content of 1 to 11 %. The sheet-like combinations thus obtained are laid one on top o~ another in several layers and are pressed to form mouldings, conveniently at temperatures between 110 and 170~ and pressures between 2.0 and 800 kp/cm2.
A ~urther known posstbility ~or manufacturing mouldings by pressing consis~s in combining aminoplast resins wlth pulverulent fillers and optionally further known additives, such as pigments, flow au~iliaries and optionally slip agents or release agents, and pressing these products in moulds at elevated temperature. Known fillers which may be used in compression moulding compositions comprising a pulverulent ~iller and an aminoplast resin of the present invention are, ~or example~ wood ~lour, cellulose powder ~ 1~339Z
including cellulose ester powder, cotton flock, flour, starch, peat, waste products from the wood industry, ground miner-als, asbestos fibres or graphite, of which the first two mentioned are preferred. Pigments which may be used the compositions of the present invention can be organic or inorganic, Suitable inorganic pigments are generally based on sulphides, oxides or mixed oxides of metals, especially of titanium, zinc, iron, chromium, cobalt, lead and cadmium.
Carbon black is a preferred black p~gment. Possible organic pigments are the compounds characterised in the Colour Index as pigment dyes.
Known flow auxiliaries which may be used include sorbitol, glycols and glycol derivatives and polyglycols.
Metal stearates, preferably zinc stearate and magnesium stearate, may additionally be employed as slip agents or release agents, which are required for trouble-free release of the moulding from the compression mould.
The aminoplast resins are mixed with the filler and option-ally the further additives in known manner, for example, in kneaders or drum mixers and this process can be carried out at elevated temperatures from 70 to 140C preferably from 105 to 120C. In relation to the energy required for kneading and the homogeneity of the combination which can be achieved, kneading at elevated temperature gives sub-stantial advantages. After mixing, the resulting combination is cooled to room temperature and generally solidifies. The solid product may be granulated and can then be pressed.
Pressing is generally carried out at temperatures between 120 and 180C, preferably 140 and 170C, under pressures of 200 to 800 ~p/cm2, preferably 400 to 600 kp/cm2. The pressing time is usually from 10 to 60 minutes for the manufacture of moulded laminates and 30 seconds to 5 minutes ~, ,,~
11~)3392 for the manufacture of mouldings using pulverulent ~illers (further described hereinbelow). Compression moulding compositions obtained by using pulverulent fillers can contain 40 to 70 %, preferably 50 to 60 %, of the aminoplast resin.
Surface coatings using the compositions of the present invention are generally manufactured in such a way that, as in the manufacture of moulded laminates, a sheet-like carrier material is first impregnated with the aminoplast resin o~ the present invention as described above and the resin content of the composition can be ~rom 25 to 45, pre~erably ~rom 30 to 40 %, relative to the weight of the total combination. As described above, ~he impregnated carrier materials are subsequently dried to a residual moisture of from 3 to 10 %. The sheet-like resin-carrier combinations thus obtained are pressed onto the sur~aces to be coated, using an adhesion promoter, under a pressure of from 2 to 12 kp/cm2, pre~erably from 4 to 6 kp/cm2, and at temperatures from 110 to 170, preferably from 140 to 150C. The pressing time is generally ~rom 30 seconds to 4 minutes, preferably irom 1 to 2 minutes.
Ii desired decorative surface coatings may be manufactured in this way by using a suitable printed or dyed decorative paper as the sheet-like resin carrier material. Curved sur~aces, such as, for example, profiled mouldings, can also be coated in a trouble-free manner with the combina-tion to be used in accordance with the invention, owing to its extremely high elasticity. It is also possible, for example, to coat chipboard sheets all round, by drawing the sheet-like combination according to the invention round the edges. This was not possible using coating agents, based ~1 39z on aminoplasts, which were previously known. It was necessary here to coat the individual plane surfaces separately.
If desired it is also possible, in the case of the sheet-like compositions used to manufacture mouldings, to print the web-like carrier materials in a decorative manner with organic pigments before the impregnation or, if sheet-like carrier materials containing cellulose fibres or textile fibres are involved, to dye or to print the carriers with textile dyestuffs.
In order to manufacture the mouldings of the present inven-tion ~rom the sheet-like compositions, several layers are pressed to produce the moulded laminates at temperatures from 110 to 170C, preferably 130 to 150C, and at a pressure of from 2.0 to 800 kp/cm2, preferably 50 to 120 kp/cm2, and most preferably 80 to 100 kp/cm2.
The moulded laminates manufactured using the aminoplast resins according to the present invention are distinguished by an outstanding elasticity and, at the same time, very good resistance to water. Owing to their extremely high res~stance values and their high tracking resistance, they are outstanding suitable for the manufacture of components in the electrical industry. The same valuable properties are also displayed by mouldings which have been manufactured using the aminoplast resins ~ccording to the invention in combination with pulverulent fillers. Further advantages of the mouldings and surface coatings which can be manu-factured in accordance with the invention are their resis-tance to high and low temperatures and to changes in temperature, and their excellent Martens heat distortion point, high impact strength and flexural strength and low after-shrinkage.
~; ~.
~, ~i~3392 Example 1 5,300 ml of methylglycol, 1,372 g of melamine and 650 g of p-formaldehyde are stirred at 120C. A clear solution has formed after 1 1/2 hours. Approximately, 1.5 of methyl-glycol are distilled off. This gives a melamine resin solution which contains 66% of condensation product (determined by the loss of weight oi a sample when heated at 120C for 1 hour), can be diluted with water to an un-limited extent and can be diluted with n-butanol to a limited extent, that is to say 1 part of the resin under consideration can be diluted with 1 part of n-butanol at 20C without becoming turbid. The analysis of the product shows that 15.4~ consist oi bound iormaldehyde and 21.3~
as bound methylglycol. The proportion of solvent is 33.8% , determined as methylglycol.
Exam~le 2 1,260 g oi melami~e, 450 g of p-formaldehyde and 6 1 oi methylglycol are stirred ior 1 1/2 hours at a bath temperature of 140C. A solution is formed. 1.5 1 of methylglycol are now distilled off. A resin which can be diluted with water in a ratio oi 1 : 2.0 (that is to say 1 ml of resin takes up 2 ml of water at 20C without becoming turbid) and can be diluted with n-butanol in a ratio oi 1 : 0.8 ls obtained.
The resin can be diluted with methylglycol to an unlimited e~tent. The resin contains 53~ o~ condensation product (1 hour at 55QC/20 mm Hg) and the viscosity, measured in a DIN
beaker with a 4 mm nozzle, is 18.5 seconds.
Exam~le 3 126 g of melamine, 40 g o~ p-formaldehyde and 500 ml of methylglycol are stirred for 2 hours at a bath temperature 11~'3~332 of 140C; a clear solution is formed. About 200 ml of methylglycol are now distilled off. A 62~ strength resin (the strength is determined as above), which contains 11,2%
oi formaldehyde and 18~ of methylglycol in a bound ~orm is obtained.
Exam~le 4 126 g of melamine, 90 g of p-formaldehyde and 1.2 l of ethylene glycol monobutyl ether are stirred at 140C in an apparatus with a descending condenser until no further water distils oif.
After distilling oi~ 600 ml of ethylene glycol monobutyl ether in vacuo, a 60~ strength resin which can be diluted with n-butanol to an unlimited extent is obtained.
ExQm~le 5 187 g of benzoguanamine, 120 g oi p-formaldehyde and 1 l of methylglycol are heated to 120C for 20 minutes; a clear solution is formed. 600 ml o~ methylglycol and water are now distilled of~. 540 g of a 62% strength resin which has unlimited miscibility with n-butanol, can be diluted with 4 parts of xylene and can be diluted with water in a ratio of 1 : 2 is obtained. The viscosity is 17 seconds ( 4 mm DIN beaker).
126 g o~ melamine, 180 g of p-~ormaldehyde and 1.2 l o~
methylglycol are boiled under reflux for 1 hour and 800 g of methylglycol and water are then distilled of~ slowly.
730 g oi an 80% strength resin are o~tained, which can be diluted with water and n-butanol to an unlimited extent.
1~339Z
~ampl~ 7 t,00~ g o~ ~la~ine, 800 g o~ p-formaldehyde and 8 1 of methyl~lycol are boile~ unde~ reflu~ ~or ~ hour3 and appro~i~ately 6 1 of methylglycol and watar are then dis-ti1led off.
3 k~ of a 91~o strangth re~in are obt~i~ed, which is mis-cible -~ith water in all proportions.
~ le 8 7 1 of diglycol monomethyl ether, 630 g o~ melamine and 48Q æ of p-for~aldehyde are heated to120-130C under a ~acuum o~ 400-500 mm ~g, whilst stirring. In the course thereof, 600 ml of water of reaction are removed by dis-tillation.
The e~ce~3 diglycol monomethyl ether (appro~imately 4 l) is no~ distilled off at 100C bath temperature under a ~acuum o~ 10 mm Hg. This recover~d diglycol monomethyl ethe- can be used again in I~rther batches.
R-(ocH2cH2)moH (I) wherein R denotes an aIkyl group having 1 to 4 C atoms and m represents an integer from 1 to 4, and which are suitable, with particular advantage, for the manufacture of mouldings, laminates and surface coatings.
It is hlown to manufacture mouldings by pressing combinations of thermosetting aminoplast resins, carrier materials and optionally further additives, such as pigments, flow auxiliaries and slip agents or release agents, at an elevated temperature. Carrier materials which are suitable for this purpose are, in principle, substantially all absorbent inorganic or organic structures. The carrier materials are impregnated with the aminoplast resins in a known manner, for example by application with brushes or rollers, spraying-on or dipping, and dried to the required residual moisture content. The sheet-like combinations thus obtained are laid one on top of another in several layers and are pressed to form mould-ings at elevated temperatures.
The sheet-like combinations of carrier material with aminoplast resins are also suitable for the surface coating of other materials, such as, for example, wood or chipboard. Thus they are used in the furniture industry, for example, for coating sheets of chipboard, hardboard or ply-wood or other wood-based materials. In this application the carrier 3 1~t33~Z
materi~ls, aft~r impregnation -~ith aminoplast resin, are pres~ed onto the wood-based ~aterials under the action o~
heat and pressure usi~g a gluing agent.
furtner known method of manufacturing mouldings by pres-Qing comprises combining aminoplast re~ins with pulverulent ~illers and optionally further known additives, such a~
pigments,~low au~iliaries and o~tionPlly slip agents or relea e agents, and pressing the~e products in mould~ at -elevated temperature.
The properties o~ a moulding ~anufactured by one of the above-mentioned process are de~endent to a large e~tent on the naturs o~ the aminoplast resi~ used. The Pm;noplast res;n~ hitherto known have disadvantages which in some cases considerably limit their applicability for the pur-poses n~icated above. ~hus, for e~ample, the sheets which coul~ be manufactured by Impregnating paper webs or te~tile web~ with the melamine resins hitherto known T~ere insuf~iciently ela~tic for m2~y end uses. Admittedly it wa~ known ~hat the elasticity and hence the bendi~g radiuQ
can be improved if modi~ying agents, such as, for e~ample, glycols, are added to the aminoplast resin. ~he improve-ment in elasticity produced i~ ~his way was, howe~er, associated with a deterioration of the resistance to wæte~, so th~t the sheets could not be u~ed for some end use~, ~or e~ample en~a~ing profiled mouldings. The laminates or wood-based mouldings manufactured by pressing or by impre~-~tir.g p per webs or textile webs or wood veneers with known ainoplast resins also did not exhibit adequate elastieity, above all in cases ~here the ~anu~actured mouldings are to be employed in situations in which they are subjected to an ~lternating e~osure to heat.
~ 1~i`3392 In the construction of electrical apparatus also, the mouldings manufactured with aminoplast resins hitherto known did not exhibit, because of their electrolyte con-tent, the desired properties, such as high electricalresistance and high tracking resistance.
Etheriiied methylolaminotriazines hitherto known have been manufactured by methylolation and simultaneous or sub-sequent etherification oi the methylolaminotriazines in the presence o~ acid catalysts (compare Houben-Weyl, volume 14/2, pages 35~-368; Ullmann Enzyklopadie der technischen Chemie (Ullmann's Encyclopaedia oi Industrial Chemistry), volume 3, pages 487-489). The degree o~
methylolation here, ior example in the case of melamine, is generally 3-6. Aiter the completion oi the reaction, it was necessary to neutralise the acid catalyst employed and to remove the resulting salt by iilteration. This was, however, generally only incompletely acco0plished, so that on storing the products manui'actured in this way an un-desirable turbidity was produced which was due to further precipitation oi the salt and, moreover, the residues of salt which could not be removed let to an extremely sharp decrease in the electrical resistance and the tracking resistance of the mouldi~gs manu~actured with aminoplast resins of this ~ind.
Previously known methylolaminotriazines etheri~ied with long-chain alcohols have hitherto been obtained mainly by trans-etheri~icatio~ oi corresponding methyl ethers under conditions oi acid catalysis.
It has now been iound, surprisingly, that thermosetting etheri~ied methylolaminotriazines which are substantially ~i - 3 _ 11(3;~39Z
free from electrolyte and contain as a statistical average 1.3 to 2 n methylol groups per mol of the aminotriazine (n being the number of amino groups in the aminotriazine) which are etherified to the extent oi at least 33Z with a glycol derivative o~ the general formula I
R-(CH2CH2)mOH (I) wherein R denotes an alkyl group having 1-4 C atoms and m represents an integer ~rom 1 to 4, do not display the dis-advantages of the thermosetting aminoplast resins known hitherto and are there~ore suitable, with particular advan-tage, ior the manufacture of laminates and wood-based mouldings o~ high elasticity and high resistance to water and also electro-technical laminates and compression mould~ngs o~ high tracking resistance.
Examples o~ glycols, oi the general ~ormula I, which can be used ~or the manu~acture o~ the etheriiied methylolamino-triazines to be used ln accordance with the invention, are methylglycol, ethylglycol, diglycol monomethyl ether, digly-col monoethyl ether, digl~col monopropyl ether, triglycol monomethyl ether, triglycol monoethyl ether, triglycol mono-propyl ether, triglycol monobutyl ether, tetraglycol mono-methyl ether, tetraglycol monoethyl ether, tetraglycol monopropyl ether and tetraglycol monobutyl ether. Examples o~ aminotriazines which can be used for the manuiacture oi the etheriiied methylolami~otriazines to be employed in accordance with the invention are melamineS benzoguanami~e and acetoguanamine.
It is preierable to employ those methylaminotriazines which contain as a statistical average 1.8-2 n methylol groups per mol oi the aminotriazine, and especially those which contain 1.8 to 1.2 n methylol groups per mol of the A
115~339Z
aminotriazine. Those methylolaminotriazines in which at least 50~ of the methylol groups are etherified, are also preferred. Amongst the glycols of the general formula I, employed for the etherification, those glycols are preferred in which R denotes a methyl group, and in addition, those in which m represents the number 1 or 2. Glycols of the general ~ormula I which are particularly pre~erred are those in which R denotes a methyl group and m represents the number 1 or 2. A further group of preferred methylolaminotriazines to be used in accordance with the invention are those which are derived ~rom melamine.
It was surprisingly iound that the use of glycol derivatives oi the general formula I
R_(OCH2CH2)mOH (I) ~or the etheri~ication of the methylolaminotriazines ren-ders the use o~ acid catalysts super~luous and that the molar ratio oi aminotriazine to formaldehyde can be varied within considerably wider limits than has hitherto been known in the case o~ normal etheriiied melamine-iormaldehyde condensation products.
Owing to the absence o$ acid catalysts, neu*ralisation of the reaction mixtures is not necessary, so that completely electrolyte-iree products may be obtained.
The freedom ~rom electrolyte is a decisive ~actor in the outstanding electrical properties of the mouldings accord-ing to the invention and the wide range o~ degree of methylolation permits the properties o~ the products accor-ding to the invention to be adjusted even to extreme industrial demands, with special reference to elasticity, resista~ce to water and resistance to heat and changes of temperature.
116~;~3~z The etherified methylolaminotriazines to be employed in accordance with the invention are manufactured by condens-ing an aminotriazine with formaldehyde and with an excess of the glycol derivative of the formula I, 1.3 to 2 n mols of formaldehyde - if n is the number of amino groups in the aminotriazine - being employed per mol of the aminotriazine and the condensation reaction being carried out in the absence of acids and alkalis. The condensation reaction usually takes place at temperatures of 50 to 180C, pre-ferably 80 to 140C. The condensation reaction is con-tinued until the degree of etherification of the reaction product is at least 33 %. The excess of glycol to be employed can be 1.2 to 20 times the theoretical amount.
After the desired degree of condensation has been achieved, the excess of glycol remaining is removed conveniently by distillation, preferably in vacuo. The water of reaction iormed during the condensation reaction is preferably dis-tilled off continuously. The removal of the water of reaction by distillation is also appropriately carried out in vacuo.
Ii the water of reaction is removed continuously by dis-tillation during the reaction, it is possible to determine, from the quantity of the latter, the degree of etherifi-cation of the reaction product which has been achleved.
The formaldehyde ls preferably employed in the form of paraformaldehyde. It is, however, also possible to use aqueous solutions of formaldehyde or solutions of formalde-hyde in the glycol derivatives of the general formula I
which are employed in accordance with the invention for the etherification.
_ _ The manufacture of mouldings by using the etherified methylolaminotriazines according to the invention is carried out by combining the etherified methylolaminotria-zine with a carrier or filler and pressing the resulting compositions under pressure at elevated temperature so as the produce mouldings.
The compositions can be obtained by impregnating, for example, absorbent sheet-like materials, such as, textile webs composed of natural or synthetic ~ibres, especially cellulose fibres; random fibre fleeces, in particular absorbent paper; and wood veneers, with the aminoplast resins of the present invention. The impregnation can be carried out in a known manner, for example by application with brushes or rollers, spraying-on or dipping, the general procedure being such that the impregnated materials contain 25 to 75 %, pre~erably 25 to 50 %, and most pre~erably 30 to 40 % of the aminoplast resin. After impregnation, the materials are dried to a residual moisture content of 1 to 11 %. The sheet-like combinations thus obtained are laid one on top o~ another in several layers and are pressed to form mouldings, conveniently at temperatures between 110 and 170~ and pressures between 2.0 and 800 kp/cm2.
A ~urther known posstbility ~or manufacturing mouldings by pressing consis~s in combining aminoplast resins wlth pulverulent fillers and optionally further known additives, such as pigments, flow au~iliaries and optionally slip agents or release agents, and pressing these products in moulds at elevated temperature. Known fillers which may be used in compression moulding compositions comprising a pulverulent ~iller and an aminoplast resin of the present invention are, ~or example~ wood ~lour, cellulose powder ~ 1~339Z
including cellulose ester powder, cotton flock, flour, starch, peat, waste products from the wood industry, ground miner-als, asbestos fibres or graphite, of which the first two mentioned are preferred. Pigments which may be used the compositions of the present invention can be organic or inorganic, Suitable inorganic pigments are generally based on sulphides, oxides or mixed oxides of metals, especially of titanium, zinc, iron, chromium, cobalt, lead and cadmium.
Carbon black is a preferred black p~gment. Possible organic pigments are the compounds characterised in the Colour Index as pigment dyes.
Known flow auxiliaries which may be used include sorbitol, glycols and glycol derivatives and polyglycols.
Metal stearates, preferably zinc stearate and magnesium stearate, may additionally be employed as slip agents or release agents, which are required for trouble-free release of the moulding from the compression mould.
The aminoplast resins are mixed with the filler and option-ally the further additives in known manner, for example, in kneaders or drum mixers and this process can be carried out at elevated temperatures from 70 to 140C preferably from 105 to 120C. In relation to the energy required for kneading and the homogeneity of the combination which can be achieved, kneading at elevated temperature gives sub-stantial advantages. After mixing, the resulting combination is cooled to room temperature and generally solidifies. The solid product may be granulated and can then be pressed.
Pressing is generally carried out at temperatures between 120 and 180C, preferably 140 and 170C, under pressures of 200 to 800 ~p/cm2, preferably 400 to 600 kp/cm2. The pressing time is usually from 10 to 60 minutes for the manufacture of moulded laminates and 30 seconds to 5 minutes ~, ,,~
11~)3392 for the manufacture of mouldings using pulverulent ~illers (further described hereinbelow). Compression moulding compositions obtained by using pulverulent fillers can contain 40 to 70 %, preferably 50 to 60 %, of the aminoplast resin.
Surface coatings using the compositions of the present invention are generally manufactured in such a way that, as in the manufacture of moulded laminates, a sheet-like carrier material is first impregnated with the aminoplast resin o~ the present invention as described above and the resin content of the composition can be ~rom 25 to 45, pre~erably ~rom 30 to 40 %, relative to the weight of the total combination. As described above, ~he impregnated carrier materials are subsequently dried to a residual moisture of from 3 to 10 %. The sheet-like resin-carrier combinations thus obtained are pressed onto the sur~aces to be coated, using an adhesion promoter, under a pressure of from 2 to 12 kp/cm2, pre~erably from 4 to 6 kp/cm2, and at temperatures from 110 to 170, preferably from 140 to 150C. The pressing time is generally ~rom 30 seconds to 4 minutes, preferably irom 1 to 2 minutes.
Ii desired decorative surface coatings may be manufactured in this way by using a suitable printed or dyed decorative paper as the sheet-like resin carrier material. Curved sur~aces, such as, for example, profiled mouldings, can also be coated in a trouble-free manner with the combina-tion to be used in accordance with the invention, owing to its extremely high elasticity. It is also possible, for example, to coat chipboard sheets all round, by drawing the sheet-like combination according to the invention round the edges. This was not possible using coating agents, based ~1 39z on aminoplasts, which were previously known. It was necessary here to coat the individual plane surfaces separately.
If desired it is also possible, in the case of the sheet-like compositions used to manufacture mouldings, to print the web-like carrier materials in a decorative manner with organic pigments before the impregnation or, if sheet-like carrier materials containing cellulose fibres or textile fibres are involved, to dye or to print the carriers with textile dyestuffs.
In order to manufacture the mouldings of the present inven-tion ~rom the sheet-like compositions, several layers are pressed to produce the moulded laminates at temperatures from 110 to 170C, preferably 130 to 150C, and at a pressure of from 2.0 to 800 kp/cm2, preferably 50 to 120 kp/cm2, and most preferably 80 to 100 kp/cm2.
The moulded laminates manufactured using the aminoplast resins according to the present invention are distinguished by an outstanding elasticity and, at the same time, very good resistance to water. Owing to their extremely high res~stance values and their high tracking resistance, they are outstanding suitable for the manufacture of components in the electrical industry. The same valuable properties are also displayed by mouldings which have been manufactured using the aminoplast resins ~ccording to the invention in combination with pulverulent fillers. Further advantages of the mouldings and surface coatings which can be manu-factured in accordance with the invention are their resis-tance to high and low temperatures and to changes in temperature, and their excellent Martens heat distortion point, high impact strength and flexural strength and low after-shrinkage.
~; ~.
~, ~i~3392 Example 1 5,300 ml of methylglycol, 1,372 g of melamine and 650 g of p-formaldehyde are stirred at 120C. A clear solution has formed after 1 1/2 hours. Approximately, 1.5 of methyl-glycol are distilled off. This gives a melamine resin solution which contains 66% of condensation product (determined by the loss of weight oi a sample when heated at 120C for 1 hour), can be diluted with water to an un-limited extent and can be diluted with n-butanol to a limited extent, that is to say 1 part of the resin under consideration can be diluted with 1 part of n-butanol at 20C without becoming turbid. The analysis of the product shows that 15.4~ consist oi bound iormaldehyde and 21.3~
as bound methylglycol. The proportion of solvent is 33.8% , determined as methylglycol.
Exam~le 2 1,260 g oi melami~e, 450 g of p-formaldehyde and 6 1 oi methylglycol are stirred ior 1 1/2 hours at a bath temperature of 140C. A solution is formed. 1.5 1 of methylglycol are now distilled off. A resin which can be diluted with water in a ratio oi 1 : 2.0 (that is to say 1 ml of resin takes up 2 ml of water at 20C without becoming turbid) and can be diluted with n-butanol in a ratio oi 1 : 0.8 ls obtained.
The resin can be diluted with methylglycol to an unlimited e~tent. The resin contains 53~ o~ condensation product (1 hour at 55QC/20 mm Hg) and the viscosity, measured in a DIN
beaker with a 4 mm nozzle, is 18.5 seconds.
Exam~le 3 126 g of melamine, 40 g o~ p-formaldehyde and 500 ml of methylglycol are stirred for 2 hours at a bath temperature 11~'3~332 of 140C; a clear solution is formed. About 200 ml of methylglycol are now distilled off. A 62~ strength resin (the strength is determined as above), which contains 11,2%
oi formaldehyde and 18~ of methylglycol in a bound ~orm is obtained.
Exam~le 4 126 g of melamine, 90 g of p-formaldehyde and 1.2 l of ethylene glycol monobutyl ether are stirred at 140C in an apparatus with a descending condenser until no further water distils oif.
After distilling oi~ 600 ml of ethylene glycol monobutyl ether in vacuo, a 60~ strength resin which can be diluted with n-butanol to an unlimited extent is obtained.
ExQm~le 5 187 g of benzoguanamine, 120 g oi p-formaldehyde and 1 l of methylglycol are heated to 120C for 20 minutes; a clear solution is formed. 600 ml o~ methylglycol and water are now distilled of~. 540 g of a 62% strength resin which has unlimited miscibility with n-butanol, can be diluted with 4 parts of xylene and can be diluted with water in a ratio of 1 : 2 is obtained. The viscosity is 17 seconds ( 4 mm DIN beaker).
126 g o~ melamine, 180 g of p-~ormaldehyde and 1.2 l o~
methylglycol are boiled under reflux for 1 hour and 800 g of methylglycol and water are then distilled of~ slowly.
730 g oi an 80% strength resin are o~tained, which can be diluted with water and n-butanol to an unlimited extent.
1~339Z
~ampl~ 7 t,00~ g o~ ~la~ine, 800 g o~ p-formaldehyde and 8 1 of methyl~lycol are boile~ unde~ reflu~ ~or ~ hour3 and appro~i~ately 6 1 of methylglycol and watar are then dis-ti1led off.
3 k~ of a 91~o strangth re~in are obt~i~ed, which is mis-cible -~ith water in all proportions.
~ le 8 7 1 of diglycol monomethyl ether, 630 g o~ melamine and 48Q æ of p-for~aldehyde are heated to120-130C under a ~acuum o~ 400-500 mm ~g, whilst stirring. In the course thereof, 600 ml of water of reaction are removed by dis-tillation.
The e~ce~3 diglycol monomethyl ether (appro~imately 4 l) is no~ distilled off at 100C bath temperature under a ~acuum o~ 10 mm Hg. This recover~d diglycol monomethyl ethe- can be used again in I~rther batches.
2.1 '~g o~ 75~0 strength resin (the strength is determined by the content of frëe ~on-etheri~ied methylglycol since, becæuse of the high boiling point of thi~ alcohol, deter-mination of the ~olids by the customary method do2s not give reproducible results), ~rhich is miscible ~th water in all proportions are obtained. It can be diluted in t~e ~01107n~g ratios with the lo110l~ling solvents:
~oluene 1:10 n-Eutanol 1:3 Iiethanol 1:
If ~et~yl~ri~lycol or ethyltriglycol is used in place o~
methyl~i~lycol and the procedure is other-,rise as described in ~ ~ple 8, essentially s~silar results are ob~ined.
1~
il6~33~z With these very high-boiling glycol derivatives it is advisable to carry out the concentrating operation under 1 mm ~g using a thin iilm evaporator.
The examples which iollow illustrate some of the possi-bilities for use oi the aminoplast resins according to the invention.
Example 9 10 sheets of an electrolyte-iree paper weighing 80 g/m2 are impregnated in the aminoplast resin manufactured according to Example 1. Aiter drying, which is carried out at 130C, the res~n content is about 60% and the residual moisture content (determined by drying a sample at 160 C ior 5 minutes~ is about 6~.
rhe papers are laid one on top oi another and are pre~sed ~ a multi-daylight press between nickel sheets chromium-plated to a high gloss, ior a period oi 15 minutes at a temperature o~ 140C and under a pressure of 80 kp/cm2.
Aiter cooling the lami~ate under pressure to approxi~ately 70C, a laminate 1.1 mm thick is obtsined. Testing this laminate gives the $ollowing data:
Curing stage in Kiton test: 2 - 3 Electrical suriace resistance DIN 53,482 : 5.5 x 10125~L
Tracking resistance DIN 53,480: stage KA 3b.
Exam~le 10 A paper printed with a wood gra~n pattern and weighing 80 g/m is impregnated in a solution, diluted with water to 40~ by weight oi solid resin, oi the aminoplast resin manu-factured according to Example 7. The resin content oi the impregnated paper is approximately 38~ and the residual moisture content is approximately 2%.
The impregnated paper is glued cold onto a chipboard sheet, using a commercially available polyvinyl acetate glue~ A
length oi the paper corresponding to the thickness oi the board is allowed to project beyond the edges o~ the chip-board and the latter are encased in a second process by bending the paper round the edge, using a suitable white glue. The paper is so elastic that no cracks are iormed during the encasing. The encased chipboard sheet can then be provided with a coating o~ an acid-curing lacquer.
Example 11 70 parts oi the resin manufactured according to Example 6, 30 parts o~ microcellulose, 4 parts oi titanium dioxide and 1 part o~ zlnc stearate are rolled out into a milled hide on a roll mill at 110C. Aiter the molled hide has been granulated, a moulding is produced in a standard bar mould at 150 - 155C and 250 kp/cm2 with a compression t~me oi 10 minutes (or 8 minutes ior testing aiter-shrinkage);
it has the iollowing properties:
Fle~ural strength according to DIN 52,362: 840 Xp/cm2 Tracking resistance according to DIN 53,480: KA3c Martens heat distortion point (~IN 53,~62): 121C
After-shrinkage according to DIN 53,464: 1%
Impact strength according to DIN 53,453: 7 kpcm/cm2.
Exam~le 12 The method o~ preparing resin as described in Example 7 was repeated a~d yielded 2.1 kg oi 70~ strength resin, the strength o~ which was determined by the value obtained on stoving for 1 hour at 120C, and which was miscible with water in all proportions. It could be diluted in the following ratios with the following solvents:
Toluene 1:40 n-Butanol 1:3 Methanol 1: ~o The resulting product was diluted with isopropyl alcohol to a concentration of approximately 45X. 2% oi p-toluene-sulphonic acid (relatlve to solid resin) was added in order to ~ccelarate curing.
A cellulose carrier web weighing approximately 250 g/m2 is impregnated in this solution to a resin content of approximately 25~, relative to the ~inal weight of paper, and is dried at 130C to a residual moisture content oi 1%.
The curing oi the resin in the sheet takes place at the same time as the drying. The melamine resin sheet is then given a lacquer coating, approximately 30 g/m~, of an acid-curing, commercially available lacquer, and is glued, as a highly elastic overlapping edge band, onto the edge oi a chipboard ~heet using a commercially available hot-melt adhesive based on ethylene-vinyl acetate copolymers.
E~am~le 13 The method of preparing resin as described in example 7 was repeated and approximately 2.1 kg of a 70~ streDgth resin which was miscible with water in all proportions, obtained.
The resin solution is then diluted with water to S0~ strength and pieces of wood veneer, 0.8 mm thic~, are impregnated i~ it to a resin content of approximately 28-32~, and are dried in a circulating air oven to a residual moisture con-116);~392 tent of 7-8%. 10 layers of this wood veneer are pressed to give a sheet between nickel sheets chromium-plated to a high gloss, at 140C, under a pressure of 110 kg/cm2 and ~or a period o~ 18 minutes. The floowing values are determined on the sheet.
Flexural strength according to DIN 52,362: 2,237 kp/cm2 Impact strength according to DIN 53,453: 21.2 kpcm/cm2 Water pick-up aiter storing ~or 96 hours at 60& 11.7~.
No cracks are formed on subjecting the sheet to an alterna-ting heat treatment o~ 3 periods o~ 20 hours at 80C, and cooling to 20C three times.
~oluene 1:10 n-Eutanol 1:3 Iiethanol 1:
If ~et~yl~ri~lycol or ethyltriglycol is used in place o~
methyl~i~lycol and the procedure is other-,rise as described in ~ ~ple 8, essentially s~silar results are ob~ined.
1~
il6~33~z With these very high-boiling glycol derivatives it is advisable to carry out the concentrating operation under 1 mm ~g using a thin iilm evaporator.
The examples which iollow illustrate some of the possi-bilities for use oi the aminoplast resins according to the invention.
Example 9 10 sheets of an electrolyte-iree paper weighing 80 g/m2 are impregnated in the aminoplast resin manufactured according to Example 1. Aiter drying, which is carried out at 130C, the res~n content is about 60% and the residual moisture content (determined by drying a sample at 160 C ior 5 minutes~ is about 6~.
rhe papers are laid one on top oi another and are pre~sed ~ a multi-daylight press between nickel sheets chromium-plated to a high gloss, ior a period oi 15 minutes at a temperature o~ 140C and under a pressure of 80 kp/cm2.
Aiter cooling the lami~ate under pressure to approxi~ately 70C, a laminate 1.1 mm thick is obtsined. Testing this laminate gives the $ollowing data:
Curing stage in Kiton test: 2 - 3 Electrical suriace resistance DIN 53,482 : 5.5 x 10125~L
Tracking resistance DIN 53,480: stage KA 3b.
Exam~le 10 A paper printed with a wood gra~n pattern and weighing 80 g/m is impregnated in a solution, diluted with water to 40~ by weight oi solid resin, oi the aminoplast resin manu-factured according to Example 7. The resin content oi the impregnated paper is approximately 38~ and the residual moisture content is approximately 2%.
The impregnated paper is glued cold onto a chipboard sheet, using a commercially available polyvinyl acetate glue~ A
length oi the paper corresponding to the thickness oi the board is allowed to project beyond the edges o~ the chip-board and the latter are encased in a second process by bending the paper round the edge, using a suitable white glue. The paper is so elastic that no cracks are iormed during the encasing. The encased chipboard sheet can then be provided with a coating o~ an acid-curing lacquer.
Example 11 70 parts oi the resin manufactured according to Example 6, 30 parts o~ microcellulose, 4 parts oi titanium dioxide and 1 part o~ zlnc stearate are rolled out into a milled hide on a roll mill at 110C. Aiter the molled hide has been granulated, a moulding is produced in a standard bar mould at 150 - 155C and 250 kp/cm2 with a compression t~me oi 10 minutes (or 8 minutes ior testing aiter-shrinkage);
it has the iollowing properties:
Fle~ural strength according to DIN 52,362: 840 Xp/cm2 Tracking resistance according to DIN 53,480: KA3c Martens heat distortion point (~IN 53,~62): 121C
After-shrinkage according to DIN 53,464: 1%
Impact strength according to DIN 53,453: 7 kpcm/cm2.
Exam~le 12 The method o~ preparing resin as described in Example 7 was repeated a~d yielded 2.1 kg oi 70~ strength resin, the strength o~ which was determined by the value obtained on stoving for 1 hour at 120C, and which was miscible with water in all proportions. It could be diluted in the following ratios with the following solvents:
Toluene 1:40 n-Butanol 1:3 Methanol 1: ~o The resulting product was diluted with isopropyl alcohol to a concentration of approximately 45X. 2% oi p-toluene-sulphonic acid (relatlve to solid resin) was added in order to ~ccelarate curing.
A cellulose carrier web weighing approximately 250 g/m2 is impregnated in this solution to a resin content of approximately 25~, relative to the ~inal weight of paper, and is dried at 130C to a residual moisture content oi 1%.
The curing oi the resin in the sheet takes place at the same time as the drying. The melamine resin sheet is then given a lacquer coating, approximately 30 g/m~, of an acid-curing, commercially available lacquer, and is glued, as a highly elastic overlapping edge band, onto the edge oi a chipboard ~heet using a commercially available hot-melt adhesive based on ethylene-vinyl acetate copolymers.
E~am~le 13 The method of preparing resin as described in example 7 was repeated and approximately 2.1 kg of a 70~ streDgth resin which was miscible with water in all proportions, obtained.
The resin solution is then diluted with water to S0~ strength and pieces of wood veneer, 0.8 mm thic~, are impregnated i~ it to a resin content of approximately 28-32~, and are dried in a circulating air oven to a residual moisture con-116);~392 tent of 7-8%. 10 layers of this wood veneer are pressed to give a sheet between nickel sheets chromium-plated to a high gloss, at 140C, under a pressure of 110 kg/cm2 and ~or a period o~ 18 minutes. The floowing values are determined on the sheet.
Flexural strength according to DIN 52,362: 2,237 kp/cm2 Impact strength according to DIN 53,453: 21.2 kpcm/cm2 Water pick-up aiter storing ~or 96 hours at 60& 11.7~.
No cracks are formed on subjecting the sheet to an alterna-ting heat treatment o~ 3 periods o~ 20 hours at 80C, and cooling to 20C three times.
Claims (28)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An etherified methylolaminotriazine substantially free from electrolyte and containing, as a statistical average, from 1.3 to (2n) methylol groups per mol of the aminotriazine, where n is the number of amino groups in the aminotriazine, which methylol groups are etherified to the extent of at least 33% with a glycol derivative of the general formula:
R-(OCH2CH2)mOH (I) wherein R denotes an alkyl group having from 1 to 4 C atoms and m repre-sents an integer from 1 to 4.
R-(OCH2CH2)mOH (I) wherein R denotes an alkyl group having from 1 to 4 C atoms and m repre-sents an integer from 1 to 4.
2. An etherified methylolaminotriazine as claimed in claim 1, which contains as a statistical average from 1.8 to (2n) methylol groups per mol of the aminotriazine.
3. An etherified methylolaminotriazine as claimed in claim 1, which contains as a statistical average from 1.8 to (1.2 n) methylol groups per mol of the aminotriazine.
4. An etherified methylolaminotriazine as claimed in any of claims 1 to 3, wherein the methylol groups are etherified to the extent of at least 50%.
5. An etherified methylolaminotriazine as claimed in any of claims 1 to 3, wherein the methylol groups are etherified with a glycol derivative of formula I in which R is a methyl group.
6. An etherified methylolaminotriazine as claimed in any of claims 1 to 3, wherein the methylol groups are etherified with a glycol derivative of formula I in which m represents the number 1 or 2.
7. An etherified methylolaminotriazine as claimed in any of claims l to 3, wherein the methylol groups are etherified with a glycol derivative of formula I in which R is a methyl group and m represents the number l or 2.
8. An etherified methylolaminotriazine as claimed in any of claims l to 3, wherein the aminotriazine is melamine.
9. A process for the manufacture of an etherified methylolaminotriazine, wherein an aminotriazine is subjected to a condensation reaction with from 1.3 to (2n) mols of formaldehyde per mol of aminotriazine, where n is the number of amino groups in the aminotriazine, and an excess of a glycol derivative of the formula:
R-(OCH2CH2)moH (I) wherein R denotes an alkyl group with l to 4 C atoms and m represents an integer from l to 4, in the absence of acids and alkalis, until the degree of etherification is at least 33%.
R-(OCH2CH2)moH (I) wherein R denotes an alkyl group with l to 4 C atoms and m represents an integer from l to 4, in the absence of acids and alkalis, until the degree of etherification is at least 33%.
10. A process as claimed in claim 9, wherein from 1.8 to 2 n mols of formaldehyde are employed per mol of the aminotriazine.
11. A process as claimed in claim 9, wherein from 1.8 to (1.2n) mols of formaldehyde are employed per mol of the aminotriazine.
12. A process as claimed in any of claims 9 to 11, wherein the con-densation reaction is continued until the degree of etherification is at least 50%.
13. A process as claimed in any of claims 9 to 11, wherein a glycol derivative of formula I wherein R is a methyl group is employed.
14. A process as claimed in any of claims 9 to 11, wherein a glycol derivative of formula I wherein m represents the number l or 2 is employed.
15. A process as claimed in any of claims 9 to 11, wherein the amino-triazine employed is melamine.
16. A process as claimed in any of claims 9 to 11, wherein the conden-sation reaction is effected at from 50 to 180°C.
17. A process as claimed in any of claims 9 to 11, wherein the conden-sation reaction is effected at from 80 to 140°C.
18. A thermosetting composition comprising an aminoplast resin and a carrier or filler wherein the aminoplast resin comprises a substantially electrolyte-free, etherified methylolaminotriazine which contains, as a statistical average from 1.3 to (2n) methylol groups per mol of the amino-triazine, where n is the number of amino groups in the triazine, which methylol groups are etherified to the extent of at least 33% with a glycol derivative of the general formula I:
R-(OCH2CH)mOH (I) wherein R is an alkyl group having 1 to 4 C atoms and m represents an integer from 1 to 4.
R-(OCH2CH)mOH (I) wherein R is an alkyl group having 1 to 4 C atoms and m represents an integer from 1 to 4.
19. A composition as claimed in claim 18 wherein a substantially electrolyte-free, etherified methylolaminotriazine which contains as a statistical average 1.8 to (2n) methylol groups per mol of the aminotriazine, is used as the aminoplast resin.
20. A composition as claimed in claim 18 wherein a substantially electrolyte-free, etherified methylolaminotriazine which contains as a statistical average 1.8 to (l.2n) methylol groups per mol of the aminotria-zine, is used as the aminoplast resin.
21. A composition as claimed in any of claims 18 to 20, wherein a substantially electrolyte-free, etherified methylolaminotriazine in which the methylol groups are etherified to the extent of at least 50%, is used as the aminoplast resin.
22. A composition as claimed in any of claims 18 to 20, wherein a substantially electrolyte-free, etherified methylolaminotriazine in which the methylol groups are etherified with a glycol derivative of the formula I, wherein R is a methyl group, is used as the aminoplast resin.
23. A composition as claimed in any of claims 18 to 20, wherein a substantially electrolyte-free, etherified methylolaminotriazine in which the methylol groups are etherified with a glycol derivative of formula I, in which m represents the number 1 or 2, is used as the aminoplast resin.
24. A composition as claimed in any of claims 18 to 20, wherein a substantially electrolyte-free, etherified methylolaminotriazine in which the methylol groups are etherified with a glycol derivative of formula I, in which R denotes a methyl group and m represents the number 1 or 2, is used as the aminoplast resin.
25. A composition as claimed in any of claims 18 to 20, wherein a substantially electrolyte-free methylolaminotriazine in which the aminotria-zine is melamine, is used as the aminoplast resin.
26. A composition as claimed in any of claims 18 to 20 comprising a pulverulent filler and from 40 to 70% by weight of the aminoplast resin.
27. A composition as claimed in any of claims 18 to 20 comprising a carrier sheet material impregnated with from 25 to 75% by weight of the aminoplast resin.
28. A composition as claimed in any of claims 18 to 20 with contains at least one additive selected from a pigment, a flow auxiliary and a slip or release agent.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2603768.3 | 1976-01-31 | ||
| DE19762603767 DE2603767A1 (en) | 1976-01-31 | 1976-01-31 | Methylolamino-triazines etherified with glycols - are devoid of electrolytes and useful for mouldings, laminates and coatings |
| DEP2603767.2 | 1976-01-31 | ||
| DE2603768A DE2603768C2 (en) | 1976-01-31 | 1976-01-31 | Electrolyte-free aminoplasts etherified with glycol ethers and process for their production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1103392A true CA1103392A (en) | 1981-06-16 |
Family
ID=25769994
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA270,645A Expired CA1103392A (en) | 1976-01-31 | 1977-01-28 | Electrolyte-free aminoplast resins and their preparation |
Country Status (7)
| Country | Link |
|---|---|
| CA (1) | CA1103392A (en) |
| CH (1) | CH625255A5 (en) |
| FR (1) | FR2339601A1 (en) |
| GB (1) | GB1521863A (en) |
| IT (1) | IT1114401B (en) |
| NL (1) | NL7700791A (en) |
| PT (1) | PT66128B (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE572158A (en) * | ||||
| FR827014A (en) * | 1936-10-19 | 1938-04-14 | Ste Ind Chim Bale | Improvements to the aldehyde condensation products of aminotriazines and their manufacturing processes |
| BE600826A (en) * | 1958-05-05 |
-
1977
- 1977-01-26 NL NL7700791A patent/NL7700791A/en not_active Application Discontinuation
- 1977-01-28 GB GB353777A patent/GB1521863A/en not_active Expired
- 1977-01-28 CA CA270,645A patent/CA1103392A/en not_active Expired
- 1977-01-28 PT PT6612877A patent/PT66128B/en unknown
- 1977-01-31 FR FR7702571A patent/FR2339601A1/en active Granted
- 1977-01-31 CH CH113977A patent/CH625255A5/en not_active IP Right Cessation
- 1977-01-31 IT IT1980977A patent/IT1114401B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| FR2339601A1 (en) | 1977-08-26 |
| IT1114401B (en) | 1986-01-27 |
| FR2339601B1 (en) | 1981-05-29 |
| PT66128A (en) | 1977-02-01 |
| NL7700791A (en) | 1977-08-02 |
| PT66128B (en) | 1978-06-30 |
| GB1521863A (en) | 1978-08-16 |
| CH625255A5 (en) | 1981-09-15 |
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