FI56974C - FOERFARANDE FOER FRAMSTAELLNING AV PAERLOR AV VAERMEHAERDANDE ELLER ICKE-VAERMEHAERDANDE FENOL-ALDEHYDHARTSER - Google Patents

Description

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Ma LJ '' UTLÄGGNINGSSKRIFT 0 03/4 • C (45) Patent granted on 12 25 1930

Patent patent

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FINLAND — FINLAND (M) Ptttnttlhtkamut - Paten tin föknlnf 1500/71 (22) Hakemlapiivi - Ansefcningtdag 28.05.71 (23) Alkupllvi - GUtighetadag 28.05 * 71 (41) Tullut slikuu - Blivlt offwitllg 23.01.72

National Board of Patents and Registration .... „..., ...,, _ · (44) Date of issue and date of issue. -

Patent and registration authorities' Antökan utlajd och utl.akrlfttn publkerad 31-01.80 (32) (33) (31) Pyy * 1® ** / etuoikeui —Begird prlorltat 22.07 * 70 France-France (FR) 7027010 (71) Saint -Gobain, 62 Bd Victor Hugo, 92 Neuilly sur Seine, France-France (FR) (72) Daniel Hanton, Estrees-Saint-Denis, France-France (FR) (7 ^) Berggren Oy Ab (5 * 0 Method of beads The present invention relates to a process for the preparation of beads from thermosetting or non-thermosetting phenol aldehyde resins.

According to known methods, these resins are prepared by condensation. In particular, phenolic resins are prepared by condensing one mole of phenol or phenol derivative with at least one mole of formaldehyde in aqueous solution. This condensation, which takes place in a basic medium, gives a resin which must be evaporated in vacuo to remove the water it contains as accurately as possible with a view to its subsequent use.

It is also known to polymerize monomers in suspension for the preparation of thermoplastic resins, such as vinyl resins, to obtain particle aggregates with a particle diameter of 0.1 to 3 mm and which are practically anhydrous.

It is also known to prepare aqueous dispersions of thermosetting plastic beads. Accordingly, Swedish Patent 149,335 discloses a process for the preparation of aqueous dispersions of partially condensed urea-2,56974 formaldehyde resin particles in which the colloidal particles of the resin are positively charged by condensing the urea with a condensed a quaternary ammonium or phosphonium group or a tertiary sulfonium group and, directly attached to a nitrogen, phosphorus or sulfur atom, an alkyl group having at least 8 carbon atoms.

German application 1,569,332 discloses a particle board binder formed by an aqueous emulsion of a resin prepared by condensing phenol with formaldehyde in the presence of barium oxide and an emulsifier and then neutralizing.

However, in the past it has not been possible to produce polycondensed thermosetting phenolic resins as beads which are practically anhydrous and whose particle size can be controlled.

This invention relates to a hitherto unknown process for the preparation of beads from a non-thermosetting or curable phenol-aldehyde resin, which process is characterized by condensing 1 mole of phenol or its derivative with 1 to 1.3 moles of formaldehyde and optionally 0.01- With 0.2 mol of a compound having amino functional groups, which causes the resin to be insoluble in the reaction medium when the degree of crosslinking of the resin is still low enough for the resin to be thermosetting, with condensation being carried out at 30-110 ° C in solution and in a homogeneous phase using a weight ratio of starting materials to water of the order of 1: 1 to form a resin which is insoluble in the reaction medium and consists of a suspension of innumerable small oily droplets in the reaction medium, which suspension balance is maintained by stirring that suspension an addition of a suspending agent, and that the condensation is continued until a degree of crosslinking corresponding to the non-thermoplastic or thermoplastic end product is obtained, after which the reaction medium is cooled, and the resin particles formed by cooling said oily droplets are recovered.

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With the process according to the invention, the resin is prepared easily and quickly and, in the case of reactive resins, leads to resins which, with a lower degree of crosslinking, are less water-soluble than known resins. Separation of the beads from the reaction medium can be carried out in a simple manner, and in the case of thermosetting resins considerable savings are achieved compared to the prior art by avoiding the otherwise necessary dewatering, e.g. by vacuum distillation, and by conventional thermal evaporation and spray drying methods. results in resins whose properties no longer correspond to those originally desired. The beads obtained by the process according to the invention are practically anhydrous, since the amount of water in these hay is always less than about 1% by weight.

In the process of the invention, a suspending agent added to separate the resin droplets as they form and prevent them from adhering to each other is preferably formed by combining a surfactant such as an alkaline alkylaryl sulfonate and a protective colloid such as carboxymethylcellulose or polyethylene glycol.

Preferred results are obtained by using the surfactant and the protective colloid in an amount such that their total amount is 1-2.5% by weight of the total weight of the reaction charge, including water.

According to a preferred embodiment of the process for preparing the resins according to the invention, the catalyst used for carrying out the polycondensation reaction is preferably an alkaline catalyst, namely an organic or inorganic base and in particular a nitrogen-containing organic base.

Examples of preferred polycondensation catalysts for use in the process of the invention include ammonia, ethylenediamine, diethylenetriamine, hexamethylenediamine and hexamethylenetetramine in a dose of 0.02 to 0.5 moles, and preferably 0.05 to 0.2 moles per mole of phenol or derivative thereof.

An optionally used insolubilizing compound containing amino functional groups is used as mentioned 4,56974 0.01 to 0.2 moles per mole of phenol or a derivative thereof, and it has proved advantageous according to the invention to use this compound in an amount of 0.03 to 0.1 moles. per mole of phenol or a derivative thereof.

For example, primary or secondary aliphatic, aromatic or alicyclic amines, and in particular hydrazine hydrate, piperazine, piperidine or dicyandiamide, can be used as the insolubilizing compound. However, a particularly good insolubilizing effect is obtained when, according to the invention, the insolubilizing amino-functional compound mentioned is the compound tetraformaltriazine having the formula: / CH2 \ ν 'CH2 \

HN N NH

I I I

HN N NH

This known compound can be prepared by reacting three moles of hydrazine with four moles of formaldehyde. Examples of other useful compounds are melamine, aniline or urea.

The condensation is carried out as mentioned at a temperature of 30 to 110 ° C, and according to the invention it has proved advantageous to carry out the condensation at a temperature of 50 to 85 ° C, especially in the case of phenol.

Cooling of the reaction mixture back to ambient temperature is accomplished by continuing to stir.

Examples of reactive monomers which are particularly well suited for polycondensation with formaldehyde are phenol or one of its derivatives, such as resorcinol, metacresol, pracresol and certain xylenols. Formaldehyde is used as an aqueous solution or prepared from pre-depolymerized trioxymethylene.

It is particularly preferred to use 1.2 to 1.8 moles of formaldehyde per mole of phenol.

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The weight ratio of organic phase (monomers, catalyst, etc.) / water can be 1: 1.

The beads prepared by the process of the invention can be used for all such resins for common purposes.

With regard to thermosetting resins, the following uses may be mentioned in particular: - as a binder for paints or varnishes in the resin solvent, the curing being effected, after evaporation of the solvent, by heating in an oven, grinding and the use of powder as a binder in mineral fiber felts or for bonding organic fibers, - manufacture of brake belts mixed in particular with asbestos fibers, - manufacture of grinding wheels by mixing manufacture of materials reinforced with mineral materials such as quartz sand.

The following examples are provided to illustrate the invention.

Example 1 To 940 g (10.0 mol) of phenol is added 1945 g (23.3 mol) of 36% formalin. The mixture is placed in a reactor maintained at 50 ° C and stirred continuously at 100 rpm. 85 g of ammonia with a viscosity of 22 ° BeaunO are added in one or more fractions.

The temperature is raised to 75 ° C and 500 g of water are added and after three hours the condensate separates into two phases. When this step is reached, a suspension is formed by adding 4 g of "Nacconol 90 F" (sodium dodecylbenzenesulfonate) and 20 g of "Tylose VHR" (carboxymethylcellulose), which are trademarks of the above-mentioned suspending agents, the former being manufactured by ALLIED CHEMICAL and the latter by ALLIED CHEMICAL. HOECHST. After 3 hours at 75 [deg.] C., the suspension is cooled and the round phenolic resin beads are separated, which are washed, centrifuged and dried. The average grain diameter of the obtained beads is 0.5 mm. They are indigestible and illuminate well the way in which a non-reactive phenolic resin is obtained by polycondensation in suspension without digestibility additives.

These beads can be used as fillers or as softeners for conventional substances such as cement, gypsum, etc.

Example 2

1645 g (14 mol) of 25.5% formalin, 93 g (1 mol) of aniline and 940 g (10 mol) of phenol are charged to a reactor at a temperature of 50 ° C. 60 g (1 mol) of ethylenediamine are then added in one or two fractions. The temperature is raised to 75 ° C and maintained at this value. After 75 minutes, 1 g of "Nacconol 90 F" and 5 g of "Tylose VHR" are added. After a total condensation time of 3 hours, round beads with a diameter of 1.25-2 mm are separated from the reaction medium.

100 g of these beads are placed dried in a test crucible and placed in a drying oven heated to 170 ° C. After 15 minutes, a dense and continuous mass of thermosetting phenolic resin is obtained, which illuminates the melting and reactivity phenomenon.

Example 3

282 g (3 mol) of phenol, 345 g (4.14 mol) of 36% formalin and 37.8 g of melamine are charged to a reactor at a temperature of 50 ° C. The temperature is raised to 75 ° C and 51.4 g of ammonia having a viscosity of 22 ° B are added in three fractions. The temperature is raised and stabilized at 80 ° C.

After two hours of condensation, a solution of 1 g of "Nacconol 90 F" and 4 g of "Tylose VHR" in 150 g of water is added. After a total condensation time of five hours, beads with an average diameter of 1.5 mm are obtained. These beads are fusible and can be used as a binder or adhesive under the same melting and firing conditions as the beads of Example 2.

Example 4

A reactor at 50 ° C is charged with 940 g (10 mol) of phenol, 60 g (1 mol) of urea, 1145 g (13.8 mol) of 36% formalin, 150 g of ammonia with a viscosity of 22 B , and 500 g of water. The temperature is raised to 7 56974 80 ° C. After 85 minutes, 1 g of "Nacconol 90 F" and 5 g of "Tylose VHR" are added. After four hours of condensation, fusible beads with a mean diameter of 0.3 mm are obtained, which can be used as in the previous example. For example, they can be used to glue or reinforce mineral or organic fibers.

Example 5

940 g (10 mol) of phenol, 1400 g of water and 15 g (0.468 mol) of hydrated hydrazine are charged to a reactor at a temperature of 45 ° C. After 4 minutes, 420 g (4.7 mol) of trioxymethylene are added, followed by 150 g of ammonia having a viscosity of 22 ° B and 500 g of water, and the temperature is raised to 80 ° C. After two hours of condensation, 2 g of "Nacconol 90 F" and 10 g of "Tylose VHR" are added. After four hours of condensation, oval beads are separated which do not pass 95% through the AFNOR No. 28 sieve (sieve mesh 0.5 mm). These beads are digestible and can be used as in the previous examples.

Example 6

To a 4 L glass reactor equipped with a stirrer at 130 rpm, a reflux condenser and a thermometer was gradually added 940 g (10 mol) of phenol at 40-50 ° C, followed by 1165 g (14 mol) of phenol. formaldehyde as a 36% aqueous solution. 0.33 moles of pure tetraformaltrazine and then 34 g (2 moles) of ammonia as a 30% aqueous solution based on NH3 were then added in small portions.

The reaction mixture was brought to 85 ° C partly by exotherm and partly by heating. After 30 minutes of reaction at this temperature, 5 g of "Tylose C 300" (carboxymethylcellulose, trade name) and 1 g of "Nacconol 90 F", both dissolved in 200 ml of water, were added. The reaction mixture was kept at 85 ° C for 2 hours, then cooled.

Separate spheres with a diameter of 0.4-0.8 mm were obtained. These beads were meltable under the conditions set forth in Example 2.

Example 7

At 45 ° C, 940 g (10 mol) of phenol, 16.5 g (0.515 mol) of hydrazine hydrate, 1165 g (14 mol) of a 36% aqueous solution of formaldehyde, 157.5 g of ammonia (22 ° B§) and 800 g of of water.

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The reaction mixture was brought to 85 ° C by heating, and the temperature was maintained at this level during condensation.

The time elapsed from the time tQ at which the reaction mixture reached 70 ° C was measured.

At t + 45 minutes, 2 g of "Nacconol 90 F" and 10 g of "Tylose VHR" were added and condensation was continued.

Several samples were prepared by the same method but by stopping the condensation at different times. The condensation was stopped by cooling to room temperature, and the obtained beads were air-dried, washed and dried.

These samples were numbered 1-5, and the condensation times were as shown in the following table: Sample No. Condensation time from time - * s_ 1 hour 50 minutes 2 1 hour 55 minutes 3 2 hours 4 2 hours 5 minutes 5 2 hours 10 minutes

The various samples were placed in a Brabender instrument used at a constant temperature of 90 ° C. The curves shown in the accompanying drawing indicate the torque observed with the instrument as a function of the sample residence time in the instrument.

These curves express the melting duration of the beads as a function of the condensation duration.

It can be seen that the operating level, expressed in minutes, at which the 90 kg C Brabender instrument has developed a torque of 1 kgm varies as a function of the condensation time of the samples, as shown in the table below.

Claims (7)

A process for preparing beads of a non-thermoplastic or thermoplastic phenol aldehyde resin, wherein phenol or a derivative thereof is condensed with formaldehyde in an aqueous medium from which the beads are separated, characterized in that in the presence of a basic catalyst, condensation is condensed. 1 mole of phenol or a derivative thereof with 1-1.3 moles of formaldehyde and optionally 0.0ΙΟ, 2 moles of a compound of functional amino groups, which compound provides insolubility of the resulting resin in the reaction medium where the degree of crosslinking of the resin is still sufficient position for the resin to be heat-curable, and the condensation is carried out at a temperature of 30-110 ° C in solution and in a homogeneous phase with a weight ratio of starting material to water of the order of 1: 1, to form a resin which Is insoluble in the reaction medium and consists of a suspension of small oil-like droplets in the reaction medium, which suspension equilibrium is maintained by stirring so that a suspension is stabilized by the addition of a suspending agent1 formed by mixing a surfactant such as an alkali metal alkylaryl sulfonate with a protective colloid such as carboxymethyl cellulose, and condensation is continued until a final cross-load or non-thermal degree corresponding to a terminal load is obtained. The reaction medium is cooled, and the resin particles formed by said oil-like droplets upon cooling are isolated. Process according to Claim 1, characterized in that 1 mole of phenol is condensed with 1.2-1.8 mole of formaldehyde. Process according to Claim 1, characterized in that the total amount of said two constituents amounts to 0.1 to 2.5% by weight of the entire reaction batch including water. Process according to any of claims 1-3, characterized in that, as a basic catalyst, an organic base or an inorganic base is used, preferably an organic nitrogen base. Process according to any one of claims 1-4, characterized in that the insoluble functional amino groups containing the compound are used in an amount of 0.03-0.1 mole per mole of phenol or derivatives thereof.