Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
  • C08G8/04—Condensation polymers of aldehydes or ketones with phenols only of aldehydes
  • C08G8/08—Condensation polymers of aldehydes or ketones with phenols only of aldehydes of formaldehyde, e.g. of formaldehyde formed in situ
  • C08G8/10—Condensation polymers of aldehydes or ketones with phenols only of aldehydes of formaldehyde, e.g. of formaldehyde formed in situ with phenol

Definitions

• TITLE IMPROVED PHENOL FORMALDEHYDE RESINS relates to improved phenol formaldehyde resins which have superior qualities of fire resistance, mouldability, insulation, and stability when compared to conventional resins.
• phenol formaldehyde resins may be formed from phenol and formaldehyde wherein formaldehyde may react with the aromatic ring at the ortho and/or para positions. This is assisted by heating but can be a slow process unless a basic or acid catalyst is included.
• the main reactions involve direct addition of phenol and formaldehyde yielding methylol derivatives as well as direct condensation of phenol and a methylol derivative with loss of water yielding methylene derivatives.
• the direct condensation reaction involving the formation of methylene groups between adjacent aromatic rings is catalysed by bases and is favoured by an excess of phenol ie. a deficiency of formaldehyde.
• the addition reaction yielding methylol derivatives is catalysed by strong bases and is favoured by an excess of formaldehyde.
• hydrophobic compounds eventually separate out as a lower or base layer.
• this layer is freed from an aqueous layer and further volatiles are removed by distillation under reduced pressure there is produced a resinous product of moderate molecular weight known as a resol or novola ⁇ which can be made to yield a cross linked polymeric network.
• Novolacs involve the initial formation of dehydroxyphenol methanes and on further condensation and methylene bridge formation form a fusible and soluble linear polymers of phenol groups separated by methylene bridges where ortho and para links occur at random.
• resol polymers are formed by condensation of methylol phenols either through methylene linkages or through ether linkages. If these reactions are carried further large numbers of phenolic nuclei can condense to give a repeating network.
• phenolic resin chemistry the four major reactions in phenolic resin chemistry are (i) addition to give methylol phenols; (ii) condensation of a methylol phenol and a phenol to give a methylene bridge; (iii) condensation of ether bridges of methylene bridges and formaldehyde, the latter reacting again in reaction (i) .
• Phenolic resins known as one stage resins may be produced by charging all reactants comprising phenol, formaldehyde, and alkaline catalyst into a resin kettle and reacted together. The ratio of formaldehyde to phenol is about 1'25:1.
• the mixture is rolled on heated mixing rolls where the reactions are carried further to the point where the resin is in the B stage or resitol nearly insoluble in organic solvents but still fusible under heat and pressure.
• the resin is then cooled and cut into final form.
• the C stage or resite which is the final, infusible, cross linked polymer is reached on subsequent fabrication eg. by moulding.
• the resins produced as described above are used in compression or transfer moulding yielding products that are heat resistant, stable and resistance to cold flow. They are also used as laminating resins, bonding resins, casting resins, coatings and adhesives and ion- exchange resins.
• Conventional phenol formaldehyde resins as described above do not have good shelf life and are relatively unstable so that storage and transportability is a major problem.
• conventional phenol formaldehyde resins have relatively low temperature resistance which is of the order of 100-300°C.
• the instability of conventional phenol formaldehyde resins is due to the fact that such resins contain water which separates out after a period of time from the resin to form separate layers of resin and water. This product cannot be used commercially.
• a further object of the invention is to provide a first component resin and a second component resin which may when mixed together form a phenol formaldehyde resin.
• the first component may be formed from phenol formaldehyde resin precursors as well as a first additive which may prevent solidification or curing of the first component resin.
• the second component resin may be formed from phenol formaldehyde resin precursors as well as a second additive which may prevent solidification or curing of the second component resin.
• the first additive may include the following compounds: (i) a gly ⁇ ol; and
• glycol and the aromatic dicarboxylic acid or tricarboxylic acid or anhydride thereof are added as a mixture.
• an alpha hydroxy acid may be added to the mixture of phenol formaldehyde resin precursors.
• the glycol is preferably glycerol for ease of convenience, availability, and also because of its relatively low cost.
• gly ⁇ ols may be used and these can be selected from propylene glycol, ethylene glycol, 1,3 propane diol, 1,2 butanediol, meso - 2,3 butanediol pina ⁇ ol, pentaerythritol and meso- hydrobenzoin.
• the aromatic dicarboxylic acid or tricarboxylic acid is preferably utilised as an anhydride to avoid adding additional water to the reactor. Therefore the preferred additive is phthalic anhydride. However it is also possible to utilise phthalic acid, isophthalic acid or terephthalic acid or hemimelliti ⁇ acid, trimellitic acid or tri esic acid.
• the glycerol and phthalic anhydride is mixed in a separate additive tank or reactor prior to being added to the reactor containing the phenol and formaldehyde resin precursors.
• the ratio of glycerol to phthalic anhydride may be from 2:1 to 5:1.
• When mixed it may form glycerol phthalate which may then be linked to any available hydroxy, carboxyl or methylene groups in the reactor to form a suitable condensation product.
• the lactic acid may also be utilised to neutralise any base present in the reactor such as sodium hydroxide.
• the alpha hydroxy acid is suitably selected from lactic acid, glycolic acid, hydroxybutyric acid, mandelic acid, melic acid, tartaric acid, mesotartaric acid or citric acid.
• lactic acid is utilised because of its availability and relatively low cost.
• the second additive may include the following compounds:
• the alpha hydroxy acid may include any of the alpha hydroxy acids already discussed above in regard to the first additive.
• Preferably lactic acid is utilised.
• the non aqueous solvent is preferably one which is water miscible and thus may be an alcohol having one, two or three carbon atoms.
• Methanol is preferred again because of its commercial availability and low cost but ethanol may also be utilised if desired.
• a reactor may have phenol and formaldehyde added thereto so as to form a phenol formaldehyde resin together with other necessary reactants such as a base which may be selected from NaOH or KOH or other suitable bases such as calcium hydroxide barium hydroxide, sodium carbonate or organic amines.
• a base which may be selected from NaOH or KOH or other suitable bases such as calcium hydroxide barium hydroxide, sodium carbonate or organic amines.
• An acid catalyst may also be used but a base catalyst is preferred.
• the first additive may be added to the reactor to prevent further curing of the phenol formaldehyde resin precursors as described above.
• the calculation would have already been made to determine the amount of water that would have to be removed from the reactor. This calculation can be made from the weights or volumes of the reactants.
• the reaction in the reactor may be substantially complete. In relation to production of the second component this may take place in the following manner.
• the aliphatic dicarboxylic acid is suitably oxalic acid by reason of commercial availability and low cost but this does not preclude any other suitable acid being used such as aloni ⁇ acid, suc ⁇ inic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid or sebacic acid. All these acids are saturated acids. It is also possible to use unsaturated acids such as maleic acid or fumaric acid.
• the phenol formaldehyde resin precursors are mixed with the lactic acid, para toluene sulphonic acid, zinc chloride and sulphuric acid or hydrochloric acid as well as methanol.
• the phenol formaldehyde precursors are passed from an initial reactor to a mixing tank containing the second additive ingredients. Previously the second additive ingredients have already been mixed together in an additive tank. The second component in liquid form may then be obtained from the mixing tank. This process may take 40 to 50 minutes.
• reactor 10 which communicates with a top condensor (not shown) through forward line 11 and return line 12.
• the top condensor cools down vapours introduced into reactor 10 before returning the liquid vapour (eg formaldehyde vapour and phenol vapour) to reactor 10.
• Sodium hydroxide may be passed into reactor 10 manually through an access point (not shown) or passed into reactor 10 through a supply line (not shown) .
• a series of concentric coils (not shown) for the purpose of the introduction of steam when heating of reactor 10 is required or cold water when cooling of reactor 10 is required. This may be accomplished by suitable valving.
• feed tank assembly 13 which comprises a feed or supply tank for formaldehyde, a feed or supply tank for phenol, and a feed or supply tank for methanol.
• feed tank assembly 13 which comprises a feed or supply tank for formaldehyde, a feed or supply tank for phenol, and a feed or supply tank for methanol.
• Each of these tanks are separate from each other and have separate lines to reactors 10 and 20 each operated by valves 14 and 15.
• reactor 20 forward line 16 and return line 17 to a top condensor (not shown) for the same purpose as the top condensor associated with reactor 10.
• Each reactor 10 and 20 has associated therewith as shown condensate tanks 18 and 19 together with supply lines 21 and 22.
• the vacuum pump may have a capacity of 30 psi.
• the vacuum pump can transfer quantities of reaction contents of reactors 10 and 20 into condensate tanks 18 and 19.
• collector tank 23 for reactor 10 having associated therewith cooling coils (not shown) .
• the contents of tank 23 may be passed to storage tanks (not shown) for the various reactants by line 24 after removal of any surface water layer.
• the first component may be then be passed into the storage tank.
• Reactor 20 also has associated therewith additive tank 25 in which the contents of the second additive may be mixed.
• the contents of reactor 20 and tank 25 may be passed into mixing tank 26 through lines 27 and 28.
• the second component may then be collected in storage tank 29 after passage through line 30.
• line 31 for passage of the contents of mixing tank 26 to a storage bin (not shown) .
• valves 32, 33, 34, 35, 36, 36, 37, 38, 39, 40 and 41 are also shown.
• Samples of reaction contents of reactor 10 may be obtained from a reactor valve (not shown) .
• the rate of temperature increase is suitably no faster than 3°C per minute. 6.
• the condensors are turned on after 30 minutes.
• the first additive is now added to reactor 10 and the temperature cooled to
• the temperature in reactor 10 may then rise to 96°C with preferably the vacuum pump operating until the appropriate
• methanol may be pumped into the methanol feed tank.
• the reactor 10 may then be cooled to 60°C and methanol is added to replace the
• the temperature of reactor 10 is maintained around 87°C for as long as possible with the temperature of the reactor never exceeding 100°C.
• tank 25 there is added methanol, ZnCl-, PTSA, H 2 S0 4 , lactic acid, glycerol and the contents agitated to dissolve same to form the second additive.
• the second additive neutraliser is passed into mixing tank 26 from additive tank 25 and the temperature is cooled till 22°C.
• Phenol is then added to reactor 20. Heating is then commenced and at 65°C the agitator is turned off and at 70°C the steam is turned off.
• the heat in reactor 20 is then allowed to rise to 100°C suitably at a rate of 1°C per 15 seconds.
• the vacuum pump is turned on 15 minutes after the reaction. After the vacuum is commenced the reactor temperature is maintained close to 100°C by increasing steam.
• reaction contents of reactor 20 are then passed into mixing tank 26 slowly. Subsequently the mixing tank is cooled to 20-22°C.
• Sulphuric acid (1) 120 - 200 (preferably 187) Lactic acid (1) 28 - 45 (preferably 42) Formaldehyde (1) 120-140 (preferably 134)
• the ratio of the second component to the first component for a given batch is 2:1 up to a maximum ratio of 4:1.
• the formaldehyde used in the first component is a 46% aqueous solution and may not include a stabiliser, requiring the temperature to be maintained above 30°C to prevent paraldehyde formation.
• a 37% formaldehyde can be used with 7% methanol stabiliser.
• the phenol which is used in the above process is pure phenol which at temperatures over 60°C liquefies and thus is used in this form.
• the NaOH used may be 1kg per 2kg of water ie. about 226kg NaOH per 452 litres of water. Lactic acid which is used is a viscous fluid but is pourable. The most concentrated solution available is used which has a maximum strength of 76%.
• sulphuric acid concentrated sulphuric acid which is about 96-98% concentration.
• formaldehyde and phenol are present in a ratio of greater than 1 and more suitably 2:1 or 3:1.
• formaldehyde and phenol are present in a ratio of greater than 1 and more 1.75:1.40.
• formaldehyde as used herein may also include any formaldehyde precursor such as hexamethylene tetramine ( CH 2 ⁇ 6 N 4 which after treatment with an acidic species (eg phenol) will generate free formaldehyde.
• formaldehyde precursor such as hexamethylene tetramine ( CH 2 ⁇ 6 N 4 which after treatment with an acidic species (eg phenol) will generate free formaldehyde.
• the resin is initially soluble in water but as the reaction proceeds the resin becomes less tolerant of water. This change in tolerance to water can be measured in two ways. Water tolerance
• reaction mixture contains water and the solubility of the resin in that water is affected by temperature the process of the reaction can be followed by doing a cloud temperature. Early in the reaction the temperature at which the mixture goes cloudy is very low. At some stage it reaches 0°C and then later on 25°C. This is the same point at which the water tolerance is found to be zero.
• Reaction time is affected by the pH of the reaction mixture.
• the reaction is slowed down once the glycerol/phthalate and lactic acid are added.
• the glycerol/phthalate could be added when the water tolerance is zero (or the cloud point is 25°C - these are the same point) and the reaction continued until a cloud point of 80°C is reached.
• the reaction would be run at 95°C to cloud point 25°C when the glycerol/phthalate is added and cooling applied to 90"C and the lactic acid added (the lactic should be added not more than 5 minutes after the glycerol/phthalate is added.
• the reaction is then continued at 85-90°C until a cloud point of 80°C is reached.
• first component and second component will react exothermically and provide a solid product or casting resin.
• This product can also be used by adding fillers to the first component eg any cellulose product such as mica, woodflour, cotton flock, chopped rags, fibreglass, nitrile rubbers, microballoons before mixing with the second component.
• the amount of filler that may be used can vary from 25-70% of the first component.
• a primer should be used to give adhesion.
• Suitable primers are EPOGARD self primer manufactured by GENERAL PAINTS or INTERNATIONAL PAINTS CC 25.
• the mixture in its desired ratio and immediately after mixing is manually applied to the fibreglass by roller or other suitable applicator similar to current techniques for application of polyesters to fibreglass.
• Foamed insulation may be achieved by adding a surfactant and foaming agent to the first component before admixture with the second component.
• the two component phenol formaldehyde resin of the invention has very good stability and a very low water content.
• the first component may be classified as a Resol (A-stage resin) or an alkaline catalysed thermosetting phenol-formaldehyde type resin consisting primarily of partially condensed phenol alcohols. Almost all the water has been removed from this product. This product has been stored in tinplate containers in a laboratory without any signs of deterioration for twelve months. Batches have been prepared with viscosities from 200 ⁇ ps to 2600 ⁇ ps.
• the second component may be classified as an acid catalyst in further Resole and has been stored in glass in a laboratory for twelve months without any signs of deterioration.
• the viscosity of this material may be approximately 400cps.
• Laminates were made using powder bound chopped strand mat and a resin mix of two parts by weight first component and one part by weight second component.
• the laminates were layed up on a sheet of laminex coated with a silicone/wax release agent.
• the matrix was rolled out with a fluted metal roller to remove air bubbles.
• a sheet of plastic was placed over the laminate before it gelled and a heavy flat plate placed on top to give a smooth finish.
• Specific Gravity of Laminate 1.28 polyyester with 25% glas s 1.4
• phenol formaldehyde of the invention unlike phenol formaldehyde resins can be
• phenol formaldehyde resins of the invention are:
• a batch can be cooked in an hour while other conventional resins take up to ten hours.
• fibreglass panels coated with the resin may be cut and will not crack. The panels will also not burn or give off toxic fumes.
• paper and cardboard could be impregnated with the resin as cores for doors or partitions.
• the resin can be painted over wood to give fire retardance.
• it can be used for water proofing wood for use in posts, walls, and resistance to termites,
• it can be used on marine piles to prevent marine growth.
• it can be bonded to polystyrene to make floating pontoons.
• petrol, oil, kerosene do not cause any deterioration or corrosion
• it can be used as a coating on cement and thus provide a surface that is easily cleared and not capable of causing contamination.
• it can be used for filling unused mine shafts or blocking them to prevent fire.
• it can be used for casting by the addition of cellulose compounds. Casts may be drilled or machined.
• the resin may be used to form brake linings, tackifiers for rubber as fillers, plywoods, foundry sand cores, oil filters, pulp preforms in the case of travel goods or car fascia panels, water lubricated bearings gear wheels and electrical switch and terminal panels. It will also be appreciated that resin properties can be varied in the manufacture thereof by variations in the relevant amounts of PTSA and H 2 S0 4 .

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Phenolic Resins Or Amino Resins (AREA)

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• 1992
  • 1992-04-02 WO PCT/AU1992/000138 patent/WO1992017528A1/en not_active Ceased
  • 1992-04-02 CA CA002107345A patent/CA2107345A1/en not_active Abandoned
  • 1992-04-02 AU AU15342/92A patent/AU655813B2/en not_active Ceased
  • 1992-04-02 US US08/122,598 patent/US5470924A/en not_active Expired - Fee Related
  • 1992-10-09 TW TW081108093A patent/TW222290B/zh active
  • 1992-10-14 CN CN92111502.4A patent/CN1085572A/zh active Pending

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