DE2012588C2 - Process for producing thermosetting binders for foundry molded parts - Google Patents

Description

This invention relates to a Ve-lessening of the ^Ττο ™!? ^ NdL · solves the problem by a procedural method according to DT-AS 19 22015. Production of a thermosetting binder

According to the French patent specification III- / 58 it is known that everything is condensed together, alkaline-condensed Phcvü-Form- 3 ° part- au ^Γ ^ "j _th pheno-formaldehyde-condensate-condensation products with non-actinic products, urea-acetone-formaldehyde-urea- Formaldehyde products, an acid or acidic catalyst and a divalent acidic catalyst and sand are mixed together with aliphatic alcohol and new from this mixture to form cores and a _{condensation product formed} above 200 ° C in half to two minutes to harden 35 Wte m ^^ _{that the a} , _kalisch koaden-

From the German patent 10 12035 the ° ™ ^urcn _p *,. _Forma i _d ehyd - condensation product using with low molecular weight aliphatic ^. ^rte _H "! _ _{material acetone nd} formaldehyde during alcohols etherified non-acetone urea form mn ■" £ * ^ ittmanes alkaline, during a daraldehyd condensates condensed acidic than Kernbindem.ttel known ^ fSlSJnWdL period, this core binder are for hot box process 40 au success ^^ 3 ^ ^εΐ ^ _{ηα6η5 & ιίοη5ρΓθαϋ Κΐ} with an unsuitable because they zwe curing times of about, STUN the \ e ™ ^ae need _n ⁿ _{iedermolekularen} aliphatic Alkoden. For the hot box process but are jjf ^ ^ JäSsiert and the sign of hardness that has now arisen is neutralized by fractions of a minute forffich ^ ^e ^ Sf _product .

After the German Offenlegungsschnft 15 69023 ^Ko "™ ^ _{process in} a single Apsoll a suitable for the hot box process binding 45 The BJ ^ Figure ¹ _{In this} phenol _{is first} obtained miuel when a Vorkonden- PJ ^ ^ Sg ^ _{kalisch ko} ndensiert, then sation product from urea, phenol and formaldehyde "f ™ ^ ° _η ³ _and formaldehyde is added and hydrolyzed with an alcohol of the general formula" ^^^ cleavage of the alkaline state R-CH ₂ OH R is hydrogen em ^ l ^^^^ _{tiaumes far} he condenses, aliphatic aromatic or heterocyclic ^ remainder 5 ° ™ ena ^ ne _{during a second}

being. Be particularly advantageous solo isopropyl "w ll be _{h AMauf of}

have proven alcohol. However, it can be shown expen- ^ ™ "^^ JJdI divalent niedermolekumentell that this binder! Need for the second Zei ™ ^ _h j ^ _{1 and AII?.} HBPß lnge curing time unless [^^^ ZL · di kd

mentally show that this binding agent! one for ^ _h j ^ _{1 and under Aü?} .

Hot box process too long curing time required unless [^^^, ZL in condition "continues not kondenes the alcohol to furfuryl 55 jS ^ STJid neutralized and then so

ttr British patent * 10 77 376 is the ^^^^ Ϊ ^ Μ ^^^^^^ Use of an acetone-free mixture of urine ^ "^^ ,, ^^ embodiment of the Verstoff-formaldehyde precondensation products with NacB euier oes »period between

alkaline condensed phenol formaldehyde con- 60 drive ^^ wrd ^ der gen ^ _dem ^^^^ ^ ^ _-

densation products as ^Hot - ^B ° ^x ; _f ^ ^{binding lttel} _ma ^b _x f ^ JTalSSchem alcohol is, wrote exirem short. According to this patent specification, max. Werügem ai.pnau _{immediately after receipt}

male strengths of the cores ermcht, 1 "· ^ gen acid divalent aliphatic alcohol type hot for 30 seconds in 200 ° C mixture of binders' ^{from a} _hd - _From ^ _hrun gsform is the Ge Karak th & lingers. The kernels should (6.9 mm 65 to ^ tzL ^ Du ^ o «^^ ^^ ^ _β ^

Kerak & ten lingers. The nuclei are said to, ^^^ ^^ ^^ ^ _β ^

harden deeply. ppctiokeiten made with the binder

n; «Her DT-AS 19 22 015 underlying strengths« rj ^^

there would now be brätand in it, a thermosetting binding cores neraugc ^ «w« v ...

3 4

According to the process according to the invention, R "i _O ni,> i
per mole of phenol 0.5 to 1.5 moles of urea, 0.1 to example
-I O ₁ mole of acetone, 2 to 7 moles of formaldehyde and 0.1 175 parts by weight of phenol and 250 parts by weight ^ to 0.8 mol of low molecular weight dihydric nliphn- igc wiisscrige 37% formaldehyde solution were reacted to "', genetic alcohol, are preferably used per 5 first signs of beginning reflux under moles of phenol 0.7 to 1.0 moles of urea, 0.2 to 0.5 moles of stirring, heated to this temperature and by acetone, 3 to 5 moles of formaldehyde and 0.2 to 0.5 moles Addition of sodium hydroxide solution kept the pH value of 8.5 dihydric, low molecular weight, phosphatic alcohol up to 9.0. After 30 to 40 minutes, they were reacted. The stated number of moles for form - another 350 parts by weight of 37% aqueous form - " " aldehyde is the total amount of io aldehyde solution to be converted, 100 parts by weight of urea, 25 parts by weight of formaldehyde, 20 to 80%, preferably 40 parts by weight of acetone and 35 Parts by weight 10% igc to 60% of the total amount of formaldehyde Na ₃ PO ₄ solution added. The reaction mixture _Λ 'become alkaline with the phenol to form the phenol- was another 15 minutes just below the re- ?' 'aldehyde r.ondensat condensed. The remaining "amount held flow temperature, then was washed with 10%' formaldehyde is later adjusted along with the urinary 15 formic acid of pH 5, and by f, cloth and acetone. The 15 parts by weight of ethanediol were added to formaldehyde for about 5 minutes / can be added in the form of an aqueous solution and or, or as, After this addition, a further 30 Mi- - ° paraformaldehyde was used neutralizing is stopped and then reacted with NaOH solution to a pH suitable for buffering the sodium hydroxide alkaline ao value 7.5. Thereafter, at about 4O ⁰ C state tertiary Natnumorthophosphat and stripped in vacuo to 420 parts by weight of water.
Acidification of formic acid. With the binders produced according to the invention the following example serves to explain the means can molded parts for metal foundry, z. B. Invention and by no means its limitation to cores, especially after the hot box process this example. as are manufactured.

Claims (1)

¹ «,! Uni -to create that neither furfuryl alcohol nor Contains descendants and yet for the Claim: Hot box process is suitable. nip D ^ AS 19 22015 concerns cm procedure for ; Process for producing a heat-resistant and thermosetting binder ibarcn binder by acidic Zusammcnkoi - 5 's "" - _"Kon dcnsationsprodukten of alkali Censoring of alkaline condensed phenol- a. . p _{|) cno} | _Formaldehyde Condcn _S ation _S - iFormaldcl.yd- condensation products, urinary ^ ⁰ "^" _and urea and formaldehyde cnthal- "cloth-acetone Formaldchyd-Kondensationsproduk- proouK _{densationsproduk} th, characterized gckcnoten and a dihydric low molecular weight tcnucn ^ Harnstoir-formaldehyde condensation : Aliphatic alcohol and neutralization of the ent- «« »jnne ^ _n condensed and contains Resulting condensation product, thereby twnspro ^ ₈ | _kaI j _sc h condensed phenol; geke η η ζ eich η et that the alkaline condensate, ™ _idehyd . _Condensation product as well as cine ™, £ ._... ", ._, ^^", H.hud condensation product ξ ° [™ ° Π ° "of any molecular aliphatic aiko- sienerneinji-ruiiiiaiuviijfu-iw ·! - "-" - "- ι-," _rt " _en jueciermuicMiiaii-i · u .. ^ .. ^» .— ~ _{: Kondcnsiert} with urea, acetone, and formaldehyde during jwuw ^ b ^^ and enlstan- cines first period alkaline, during a 15 '°' ^b _{K densalionsp} is neutralized roduct, • subsequent second period acidic kor.- ^α "£. _{Verfa] ircn} consists of three processes that condenses in, the resulting condensation product w _getrenn te apparatuses carried out will, -With a divalent low molecular general "|., ^ _{1 from} <j _s manufacturing processes for the Phenolphatischen alcohol condensed sour 'and' ^ ^m" 3, _dehvd .Kondensationsprodukt, the urea now resulting condensation product newly * "^" ^^^ ^^ "^. The product of condensation and is neutralized. a common condensation process. It is now the object of the present invention, to offer a process that differs from the _{Z5 stated} that it was advantageous that it consisted of a single piece of equipment requiring only one piece of equipment