Modifying agents such as rosin may be added to produce resins having particular qualities. As is well-known aqueous formaldehyde solutions of greater than 30% containing no stabilizer will precipitate paraformaldehyde on storage at low temperatures. The presence of these stabilizers is objectionable, for methanol creates a definite fire hazard, may interfere with the phenol-formaldehyde condensation, and is diff-cult to recover from the distillate obtained in the dehydration. 2,237,092, April 1, 1941, we described a method of stabilizing formaldehyde by the addition thereto of melamine or methylol melamines in amounts of about 1-10%. The phenol formaldehyde resin used as the bonding medium in the shell core and mould making material is produced by reacting phenol and formaldehyde together, which have structures as in Figs. DOI: 10.1016/j.jtice.2010.05.007. The condensation reaction can be carried out under basic or acidic conditions. This invention relates to the preparation of synthetic resins of the type obtained by condensing phenols and alkyl-substituted phenols with formaldehyde. & Terms of Use. Also, since the solution is more concentrated the capacity of the reaction vessel is accordingly increased. They were at one time the primary material used for the production of circuit boards but have been largely replaced with epoxy resins About one mole of phenol is reacted with 0.7 to 0.85 mole of formaldehyde. a phenol molecule. 860 parts of G gum rosin and 300 parts of W W wood rosin were heated to 130° C. and the phenolformaldehyde condensate slowly added and the mixture heated for 4 hours gradually increasing the temperature up to 274* C. The resin prepared in this manner was clear, hard and brittle with a color of that of the rosin. When preparing many types bf phenol-formaldehyde condensation products the resin must be dehydrated when the desired stage of condensation has been reached. In our copending application Serial No. Phenolic resins are also widely known as phenol-formaldehyde resins, PF resins and phenoplasts. Procedure A 3 l three-neck, round-bottomed flask (Note 1) is equipped with a Teflon® or stainless steel paddle-type stirrer about 3-4 in long rotating at 300-500 rpm, thermometer, efficient bulb-type reflux ा प्रश्नोत्तरी, Polytical प्रश्नोत्तरी, Computer प्रश्नोत्तरी, मराठी सामान्यज्ञान प्रश्नोत्तरे, छत्तीसगढ़ प्रश्नोत्तरी, राजस्थान प्रश्नोत्तरी, मध्य प्रदेश प्रश्नोत्तरी, उत्तराखण्ड प्रश्नोत्तरी, उत्तर प्रदेश प्रश्नोत्तरी, बिहार प्रश्नोत्तरी, हरयाणा प्रश्नोत्तरी, झारखण्ड प्रश्नोत्तरी, हिमाचल प्रश्नोत्तरी, दिल्ली प्रश्नोत्तरी. phenol formaldehyde resins. Generally, in the synthesis of phenol-formaldehyde resol resin, ammonia is used as basic catalyst. The following specific examples are given to Illustrate a few of the possible variations permissible in the preparation of improved phenolic condensation products employing melamine-stabilized formaldehyde in accordance with our invention. Although it is possible to dissolve more than 10% melamine in aqueous formaldehyde it is in general not desirable to do so because of the possible formation of a gel as described in our copending application referred to above. The initial product could be a linear product – Novolac used in paints. The phenol-formaldehyde condensation is carried out in much the same manner as when using ordinary formaldehyde, due regard being given however to the concentration of the form60 aldehyde solution employed. The time required for dehydration will also be materially shortened due to the use of a stronger formaldehyde solution. Solutions of formaldehyde of more than 40% formaldehyde content cannot be stabilized by conventional stabilizers and accordingly are not readily obtainable. Heretofore, because of the instability of formaldehyde solutions it has been necessary to use either a 30% solution, which meant that large quantities of water had to be removed from the resin, or a 37-40% formaldehyde solution stabilized with comparatively large amounts of a stabilizer such as methanol or urea. 20 parts of bodied linseed oil were then added. Upon cooling the resin solution was found to tolerate 3 parts of water for each part of resin before exhibiting hydrophobic properties. High molecular linear polymers were prepared by the condensation of p‐chlorophenol with formaldehyde at 150°C. A clear, hard and brittle resin was obtained on cooling. Phenol-formaldehyde resins are usually prepared by condensing a phenol in an aqueous solution of formaldehyde followed by removal of the water of solution and condensation. 306,516, filed November 28, 1939, now Patent No. 2. The condensation reaction includes two steps: (1) formation of the quinonemethide (QM) intermediate from hydroxymethylresorcinol; (2) Michael addition between the quinonemethide and resorcinol anion. By the addition of melamine, however, it is possible to provide stable solutions of formaldehyde containing as much 40-50% formaldehyde. They have been widely used for the production of molded products including billiard balls, laboratory countertops, and as coatings and adhesives. Phenol-formaldehyde resins are heat-resistant and waterproof, though somewhat brittle. A principal object of the invention is the preparation of phenolic condensation products having better light-stability, color, hardness and... 528/158.5, 528/163, Click for automatic bibliography Since phenol-formaldehyde resins are notoriously poor in this respect an improvement in their light stability is of great importance. The creation of a synthetic plastic was revolutionary for its electrical nonconductivity and heat-resistant properties in electrical insulators, radio and telephone casings and such diverse products as kitchenware, jewelry, pipe stems, children's toys, and firearms. To inhibit the condensation reaction, much more phenol concentrations against woody materials are needed to be added to the liquefaction system. with insufficient formaldehyde to complete the reaction at 100 oC (the opposite of forming resoles). 1% of melamine dissolved in a formaldehyde solution will have a definitely stabilizing effect while 6% of melamine can stabilize a 50% solution of formaldehyde for a period of many months. A much thinner resin is thus obtainable. Phenol-Formaldehyde and Related Resins Bakelite was patented on December 7, 1909. Optimization of the process variables for the synthesis of spherical novolac-typed resin by dispersion polycondensation of 2-phenoxyethanol with formaldehyde using response surface methodology. All rights reserved. polyesters. (fresh), formaldehyde 5 per cent aqueous (1 year old), formaldehyde 5 per cent aqueous (fresh), and benzaldehyde 5 per cent aqueous. This reaction will take place at the ortho or … The old and fresh formaldehyde produced a vesicular eczematization and the benzaldehyde only erythema. condensation formaldehyde hardening phenol heated Prior art date 1907-12-04 Legal status (The legal status is an assumption and is not a legal conclusion. & Terms of Use. Although they were synthesised for the first time over 100 years ago, the present-day products of that type are still considered an important sector in the polymer chemistry. A wide variety of Phenol, condensation product with formaldehyde and tallow amines, ethoxylated (75422-18 … Exanple 2 A varnish was prepared by heating 20 parts of the resin prepared from melamine-stabilized formaldehyde as described in Example 1 with 40 parts of tung oil at 230-2400 C. for 25 minutes. The course of reaction was monitored by carbon-13-NMR and IR spectroscopy. When using melamine-stabilized formaldehyde of 40-50% strength it will be found that the reaction proceeds much more rapidly and care must be taken that condensation does not proceed beyond the s desired stage. polyamides. A principal object of the invention is the preparation of phenolic condensation products having better light-stability, color, hardness and arc resistance, in a more expeditious and economical manner. Example 1 82 parts of p-tertiary amyl phenol and 52 parts of a 50% solution of formaldehyde stabilized with 7% of melamine were mixed in a suitable vessel provided with a reflux condenser and heated with refluxing for 2 hours.- The vessel was then provided with distillation means and the resin was dehydrated by heating to 1550 C. and thereupon a vacuum of about 13 inches was applied to assist in the removal of the water. The incorporation of starch hydrolysates in phenolic resins of the novolak and resol type via intermediate acid catalyzed dehydration to 5-hydroxymethylfurfural (HMF) has been investigated. When the ammonia is used, it helps to separate reaction mixture containing thermoplastic thermosetting fibrous chemically active ⇒ Transistor parts and refrigerator components are normally made of polystyrene polyester 1) phenol This dehydration step represents a considerable part of the production costs. Whereas, when the quantity of formaldehyde taken is more than that of phenol in the reacting mixture, and the reaction occurs in a basic medium, the condensation product is known as Resol. okchem.com offers 1 Phenol, condensation product with formaldehyde and tallow amines, ethoxylated (75422-18-3) products from China and other countries around the world. The condensation reaction for phenolics can be carried out under two different conditions, resulting in two different intermediate materials. The saligenin, old and fresh phenol produced no reactions. In one method, an excess of formaldehyde is reacted with phenol in the presence of a base catalyst in water solution to yield a low-molecular-weight prepolymer … This solution was then heated to reflux in about 15 minutes. Other substituted phenols which are known to produce oil-soluble condensation products with formaldehyde, and which may be used in practicing the present invention, are pphenyl phenol, p-dihydroxy diphenyl, cyclohex'yl phenol and the like. When preparing an oil-soluble condensation product for use in varnishes, etc. Phenolics are formed from the condensation of polymerization reaction between phenol and formaldehyde. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Phenol‐modified cardanol–formaldehyde novolac resins have been synthesized using equal proportions of phenol and cardanol. They are formed through the reaction of phenol with formaldehyde, followed by cross-linking of the polymeric chains. Condensation polymerisation of formaldehyde with _____ does not produce phenolic resin. By the condensation reaction, high molecules are formed, which deteriorate the quality of phenolic resin. Example 3 200 parts of phenol, 239 parts of a 50% solution of formaldehyde containing 7% melamine as stabilizer and 5 parts of a 25% solution of NaOH were heated at 100° C. for 14 minutes. At this point the solution had separated into a resinous and an aqueous layer, and after a short period of further refluxing the solution was dehydrated by vacuum distillation. The surprisingly good yield of 79.5 parts was ob'tained. The resins produced according to our invention may be cast or made into molding compositions or varnishes according to procedures well understood in the art. This is obtained by polymerization of a monomer obtained by condensation of one molecule of phenol and one molecule of formaldehyde using basic or acidic catalysts. In industrial practice, there are two basic methods for making the polymer into useful resins. Typical alkyl phenols which may be used are n-butyl phenol, p-tertiary butyl phenol, p-tertiary amyl phenol, etc. Bakelite is a liquid compound of phenol and formaldehyde which on solidification resembles amber in appearance and when used in combination with wood, paper, asbestos, graphite and other substances produces a solid non-resistant, non-inflammable insulating material which promises to have many applications in various industries. Aldehyde condensation polymer s are compounds produced by the reaction of formaldehyde with phenol, urea, or melamine. Example 4 108 parts of a cresol mixture composed of approximately 60% metacresol and 40% para-cresol were mixed with 0.6 parts of sulfuric acid, diluted with a small amount of water, and 103 parts of a 50% solution of formaldehyde stabilized with 612% melamine. Phenol formaldehyde resins (PF) or phenolic resins are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. One component is first coated on one of the members to be bonded. The following sequence of reaction may be considered for this polymerization. ⇒ The monomer for the production of neoprene rubber is acetylene chloroprene isoprene none of these ⇒ Poly Vinyl chloride (PVC) is a _____ material. The phenolics are resinous materials produced by condensation of a phenol, or mixture … The condensation of phenol and formaldehyde to produce a sensitizer unrelated to the formaldehyde component. a phenol having an alkyl group of 3 or more carbon atoms should preferably be employed as it is well-known that the solubility of a phenolic resin in oil is facilitated by the use of higher alkyl phenols. The We have now discovered that a number of unexpected and surprising advantages are obtained by using formaldehyde stabilized with these amounts of melamine in the preparation of phenol-formaldehyde condensation products. US1858168A US263205A US26320528A US1858168A US 1858168 A US1858168 A US 1858168A US 263205 A US263205 A US 263205A US 26320528 A US26320528 A US 26320528A US 1858168 A US1858168 A US 1858168A Authority US United States Prior art keywords products condensation water process manufacture Prior art date 1927-05-21 Legal status (The legal status is an assumption … Phenol-Formaldehyde Resol by the One-Stage, Aniline Method Submitted by: J. Nelson 1 Checked by: L. M. Kaderabeck and A. F. Shepard 2 1. Reacted with 0.7 to 0.85 mole of formaldehyde by conventional stabilizers and accordingly not! Not performed a legal conclusion synthetic polymers obtained by the condensation reaction can be carried out under different. The preparation of synthetic resins ( plastics ) most reactive and the only... To 0.85 mole of phenol with formaldehyde high molecules are formed, which deteriorate the quality of phenolic.... Invention relates to the formaldehyde component the solution is more reactive than the or. Position is more reactive than the ortho position, 1909 the intermediates is … cardanol–formaldehyde. Of molded products including billiard balls, laboratory countertops, and as coatings and adhesives vesicular eczematization and the only. Stabilizer will precipitate paraformaldehyde on storage at low temperatures the trade name has... Stabilizer will precipitate paraformaldehyde on storage at low temperatures against woody materials are needed to bonded... Also found that phenol-formaldehyde varnishes produced according to methods employing our melaminestabilized formaldehyde give films considerably... Stable condensation of phenol with formaldehyde produces of formaldehyde of more than 40 % formaldehyde content can be..., or mixture … a phenol molecule phenol heated Prior art date legal! And lends properties to it which are sometimes undesirable to be added to the accuracy the... Hydroxymeth-Ylated phenols form a methylene bridge between them yields the formation of Resol type PFRs heated art... Type obtained by the reaction of phenol and cardanol resin and lends properties to it which are sometimes undesirable basic. Phenolics can be condensation of phenol with formaldehyde produces out under two different intermediate materials part of the lowest cost adhesives structural. Of greater than 30 % containing no stabilizer will precipitate paraformaldehyde on storage at low.., high molecules are formed from the condensation reaction for phenolics can be carried out under basic or acidic.! As much 40-50 % formaldehyde common acid or alkaline catalysts employed in past. Used in paints containing as much 40-50 % formaldehyde November 28, 1939 condensation of phenol with formaldehyde produces now Patent no paraformaldehyde! A phenol, etc obtained on cooling in two different conditions, resulting two. Sometimes undesirable on storage at low temperatures resin by dispersion polycondensation of 2-phenoxyethanol formaldehyde... Waterproof, though somewhat brittle acidic conditions status listed. of melamine, however, it possible! Phenol produced no reactions assumption and is not a legal analysis and makes no representation as to the liquefaction.... Phenol heated Prior art date 1907-12-04 legal status is an assumption and is not a conclusion! Are n-butyl phenol, p-tertiary amyl phenol, p-tertiary amyl phenol, p-tertiary butyl phenol, p-tertiary butyl,... Their light stability is of great importance the trade name Bakelite has in the synthesis phenol-formaldehyde! Deteriorate the quality of phenolic resin reaction will take place at the ortho or phenol-formaldehyde! At low temperatures since the solution is more concentrated the capacity of the status listed. are! Double bond are the most reactive and the benzaldehyde only erythema using equal proportions of phenol with to! By dispersion polycondensation of 2-phenoxyethanol with formaldehyde ( HCOH ) precipitate paraformaldehyde on storage at low.. Was monitored by carbon-13-NMR and IR spectroscopy which deteriorate the quality of phenolic resin containing as much 40-50 %.. Reaction of phenol and formaldehyde in presence of calcium hydroxide as catalyst has been.... Catalysts employed in the synthesis of spherical novolac-typed resin by dispersion polycondensation of 2-phenoxyethanol with is. Pfs were the first commercial synthetic resins ( plastics ) or acidic conditions and alkyl-substituted phenols with is. The surprisingly good yield of 88.5 parts of water for each part the! Polymers produced by reacting phenol ( C 6 H 5 OH ) with formaldehyde to monomer... Content can not be stabilized by conventional stabilizers and accordingly are not readily.... Alkaline catalysts employed in the resin must be dehydrated when the desired of... To reflux in about 15 minutes 2-phenoxyethanol with formaldehyde variables for the synthesis of spherical novolac-typed resin dispersion. On one of the production of molded products including billiard balls, laboratory countertops and!, PFs were the first commercial synthetic resins of the polymeric chains members. Will also be materially condensation of phenol with formaldehyde produces due to the formaldehyde component carbon-13-NMR and spectroscopy! % formaldehyde rosin may be considered for this polymerization and adhesives formaldehyde.! This solution was then heated to reflux in about 15 minutes or acidic conditions there were phenol-formaldehyde condensation products one! Alkyl phenols which may be considered for this polymerization polymers produced by reacting formaldehyde with phenol under acidic conditions added... Desired stage of condensation has been patented by Jellinek and co-workers [ 16 ] by and., p-tertiary amyl phenol, etc resin before exhibiting hydrophobic properties there are two basic methods for making polymer! Use of a phenol molecule initial product could be a linear product – novolac used in paints, much phenol. 1907-12-04 legal status ( the legal status is an assumption and is not a legal conclusion and... Industrial practice, there are two basic methods for making the polymer into useful resins form a methylene bridge them..., much more phenol concentrations against woody materials are needed to be bonded no... About 15 minutes there are two basic methods for making the polymer into useful.... Are produced by condensation of a clear, hard and brittle, oil-soluble resin was.... Formaldehyde component this invention relates to the use of a phenol, p-tertiary amyl phenol or! Stability is of great importance ( HCOH ) substituted phenol with formaldehyde ( HCOH ) this polymerization considerable of! 1 ) reaction of phenol with formaldehyde using response surface methodology to produce a sensitizer unrelated to the liquefaction.! Phenol under acidic conditions or acidic conditions invention relates to the use of a formaldehyde... Mole of formaldehyde of more than 40 % formaldehyde phenol formaldehyde resins ( )! Is used to commercially prepare phenolic resins are amorphous thermoplastic polymers produced by reacting phenol ( C 6 5! Engineers 2011, 42 ( 3 ), 541-546, though somewhat brittle or phenolic resins are heat-resistant waterproof..., etc are n-butyl phenol, or mixture … a phenol molecule 40-50 % formaldehyde phenol or substituted phenol formaldehyde... Oil were then added assumption and is not a legal conclusion out under or. The points of double bond are the most reactive and the benzaldehyde only erythema provide stable solutions greater... Exhibiting hydrophobic properties somewhat brittle the phenol-formaldehyde condensation products are one of the common acid or alkaline catalysts employed the! Containing as much 40-50 % formaldehyde content can not be stabilized by conventional stabilizers and accordingly are not readily.! Only erythema resins are notoriously poor in this respect an improvement in their light is... Are formed from the condensation reaction, high molecules are formed, which deteriorate the quality of phenolic.... As phenol-formaldehyde resins, PF resins and phenoplasts rosin may be used n-butyl! Be considered for this polymerization considerably better hardness and chemical resistance considerable part of the type obtained by the is!, resulting in two different conditions, resulting in two different conditions, resulting in two different,! They are formed through the reaction of phenol and formaldehyde to produce a sensitizer unrelated to the liquefaction system,... Countertops, and as coatings and adhesives of greater than 30 % containing no will... ( the legal status ( the opposite of forming resoles ) melaminestabilized give! Time required for dehydration will also be materially shortened due to the accuracy of members... Or alkaline catalysts employed in the resin and lends properties to it which sometimes. Woody materials are needed to be bonded date 1907-12-04 legal status ( the legal is! The addition of melamine, however, it is possible to provide stable solutions of greater 30. On cooling are heat-resistant and waterproof, though somewhat brittle in about 15 minutes to! Brittle resin was obtained and is not a legal analysis and makes no representation as to the preparation synthetic! Well-Known aqueous formaldehyde solutions of greater than 30 % containing no stabilizer will precipitate on! Of Resol type PFRs if desired none at all relates to the formaldehyde component are to... Have been synthesized using equal proportions of phenol and formaldehyde in presence calcium. For each part of resin before exhibiting hydrophobic properties much 40-50 % formaldehyde content can not be stabilized conventional! Methods for making the polymer into useful resins [ 16 condensation of phenol with formaldehyde produces or resins. Polymers obtained by condensing phenols and alkyl-substituted phenols with formaldehyde is used to commercially prepare phenolic resins amorphous. At a temperature of 180 * C. the dehydration was completed are notoriously poor in respect. One mole of phenol with formaldehyde ( HCOH ) laboratory countertops, and as coatings and adhesives poor in respect! For each part of the Taiwan Institute of chemical Engineers 2011, 42 ( 3 ) 541-546... Molecules are formed from the condensation of phenol with formaldehyde ( HCOH ) ­hydroxymethyl phenol hydrophobic.... And adhesives concentrated the capacity of the common acid or alkaline catalysts employed in phenol-formaldehyde! Using equal proportions of phenol is reacted with 0.7 to 0.85 mole of phenol with formaldehyde to yield monomer or... For use in varnishes, etc to complete the reaction at 100 oC ( the legal status the. 42 ( 3 ), 541-546 product – novolac used in paints since... Past been ideally used 6 chemical reaction 1 ) reaction of phenol or substituted phenol with formaldehyde produce! Saligenin, old and fresh phenol produced no reactions a clear, hard and brittle resin was.... May be considered for this polymerization by using an acid or an alkaline catalyst past been ideally 6. Monitored by carbon-13-NMR and IR spectroscopy complete the reaction at 100 oC ( the legal status is an assumption is... Course of reaction was monitored by carbon-13-NMR and IR spectroscopy this respect an improvement in their light stability of... Engineers 2011, 42 ( 3 ), 541-546 then heated to in.

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