Rubber compounding resin

Abstract: A rubber compounding resin which is low fuming, nonhygro­ scopic and low in free resorcinol. It is made by first reacting resorcinol or other phenolic compound and styrene or other vinyl compound in a molar ratio of 1.0 mole of resorcinol to 0.25 to 1.0 mole of styrene after which formaldehyde or other aldehyde is added in the amount of 0.5 to 0.7 moles. Alternatively, the resorcinol can first be reacted with the formaldehyde after which the styrene is added. The composition resulting from the above procedure has been identified as having the structure wherein X is hydroxyl, hydrogen or an alkyl group having 1 to 4 carbon atoms. An intermediate in making the above compound has been identified as having the structure wherein X is hydroxyl, hydrogen or an alkyl group having 1 to 4 carbon atoms.

Description: This invention relates to phenolic resins which are used in forming adhesives and, in particular, to resorcinol-aldehyde resins which are used with curing agents in rubber to give improved tyre cord-to-rubber adhesion. Resorcinol-aldehyde resins of the novolak type are used as bonding agents in rubber to promote adhesion of steel cord to the rubber. The known resins generally have 10% to 20% unreacted resorcinol and produce objectionable fuming when added to the rubber. Also, the resins are hygroscopic and may present a problem in storage and handling. Efforts to improve these resins by increasing the charge of formaldehyde to react with more of the resorcinol have not generally been successful: it has been found that whilst there is a lowering of the amount of unreacted resorcinol, the softening point of the resin becomes too high to allow compounding with rubber. It is, therefore, an object of the invention to provide a phenolic resin of the novolak type that is low fuming, nonhygroscopic, low in free resorcinol and capable of cross-linkage with curing agents in rubber to give improved cord-to-rubber adhesion. In GB-A-1204519 there is disclosed a process for the manufacture of electrical grade laminates, in which a resol resin is used. The resol resin is formed from phenol, styrene or a styrene derivative and a molar excess of aldehyde. In DE OLS 2330850 there is disclosed a process for forming alkylarylphenol solutions from phenol and styrene or a styrene derivative, the solutions being used to prepare resol resins by reaction with a molar excess of formaldehyde. In DE OLS 2150216 there is disclosed a process for the preparation of resol resins in which phenol is reacted with styrene subsequent to which a molar excess of formaldehyde is added. In DE-A-689600 there is disclosed a reaction product of styrene and resorcinol. In GB-A-1131163 there are disclosed water-soluble resol resins made from a molar excess of formaldehyde and a Friedel-Crafts catalysed condensation product of phenol itself or a mixture of phenol with up to 20% cresol, and styrene or alkyl-substituted styrene. In DE OLS 2411297 there is disclosed a resol resin which is the reaction product of a molar excess of formaldehyde and a condensation product of phenol and styrene. In US-A-2602076 there is disclosed oil-soluble phenolic resol resins formed from a molar excess of formaldehyde and a condensation product of phenol and styrene. According to a first aspect of the present invention there is provided a process for making a phenolic resin, for use in rubber compounding, which process comprises the steps of reacting a compound having the formula I in which X is hydroxyl, hydrogen or an alkyl group having from 1 to 4 carbon atoms, with a compound having the formula II Y - CH = CH₂ II in which Y is phenyl, hydrogen or an aliphatic alkyl group having from 1 to 4 carbon atoms, and with a compound having the formula III in which Z is hydrogen or an alkyl group having from 1 to 4 carbon atoms; and wherein the molar ratio of the compound of formula III to the compound of formula I is in the range of from 0.5 to 0.8 moles to 1.0 mole. According to a second aspect of the present invention there is also provided a phenolic resin when made by the process of the invention. A preferred phenolic resin according to this aspect of the invention is one prepared by the process of the invention where in the compound of formula I X is hydrogen, in the compound of formula II Y is phenyl, and in the compound of formula III Z is hydrogen whereby the phenolic resin can be represented by formula IV According to another aspect of the present invention there is used in a rubber composition a phenolic resin according to invention and a curing agent therefor. We have found that vinyl compounds and, in particular, styrene can be reacted either with (1) the resorcinol or other phenolic compounds prior to reaction with formaldehyde or other aldehydes, or (2) with the free resorcinol remaining after the resorcinol/phenol formaldehyde reaction is completed to give low fuming, nonhygroscopic resins containing from 0% to 5% free resorcinol. Surprisingly and unexpectedly, the softening point of the resin is not raised by the reaction with styrene, and the adhesion to steel cord properties compared to conventional resins remain high. Phenolic resins have also been successfully prepared using stripped crude resorcinol and blends of resorcinol and resorcinol still bottoms, and the procedure is applicable for phenol-resorcinol formaldehyde type resins. The compound of formula I is preferably resorcinol. The compound of formula II is preferably styrene. The compound of formula III is preferably formaldehyde. The molar ratio of the compound of formula I to the compound of formula II is preferably approximately 1 mole to 0.25-1.0 mole. The process may be carried out by (a) first reacting the compound of formula I with the compound of formula II and then (b) reacting the product of step (a) with a compound of formula III. Step (a) may be carried out at a temperature in the range of from 120 to 140°C, and may be effected in the presence of an acid catalyst, e.g. p-toluene sulphonic acid. Step (b) may be carried out at a temperature in the range of from 110° to 130°C. Resorcinol still residue and sodium hydroxide may be introduced in step (b). Alternatively, the process may be carried out by (a) first reacting the compound of formula I with the compound of formula III and then (b) reacting the reaction product of step (a) with the compound of formula II. Step (a) may be carried out at a temperature in the range of from 100 to 120°C. In step (b) dehydration at atmospheric pressure at a temperature in the range of from 130 to 150°C may take place before the compound of formula II is added. Step (b) may subsequently be carried out at a temperature in the range of from 130 to 150°C. Step (b) may be effected in the presence of an acid catalyst, e.g. p-toluene sulphonic acid. Resorcinol still residue and water may be introduced in step (a) and sodium hydroxide in step (b). In one embodiment of the process of this invention, resorcinol and styrene are reacted at a molar ratio of 1 mole of resorcinol to 0.25 to 1.0 moles of styrene in the presence of an acid catalyst at 120°C. Thereafter, formaldehyde is added at a molar ratio of 0.5 to 0.7 and reacted at 100°C, after which the reaction product is dehydrated. In another embodiment of the process of this invention, resorcinol and formaldehyde are reacted at a molar ratio of 1 mole of resorcinol to 0.5 to 0.7 moles of formaldehyde at 100°C. The reaction product is then dehydrated at atmospheric pressure to 140°C. Styrene at a molar ratio of 0.25 to 1.0 is then added to complete the reaction at 140°-150°C. The invention is further described with reference to the attached drawings in which: Figure 1 is a flow diagram which illustrates a process which is a preferred embodiment of the present invention. Figure 2 is a flow diagram which illustrates a process which is an alternative embodiment of the present invention. Referring to Figure 1, one way to make the resin of the present invention is first to charge a reactor with molten resorcinol and an acid catalyst. Suitable catalysts would include, but are not be limited to, p-toluene sulphonic acid, and phenol sulphonic acid, toluene sulphonic and benzene m-disulphonic acid. After 10 minutes of mixing the resorcinol and catalyst, styrene would then be added streamwise for a period of from ¾ to 1¾ hours while the temperature is at 120° to 140°C. After all the styrene has been added, the temperature is maintained at 120° to 140°C for ½ hour. Part of the formaldehyde is then added to the reactor streamwise over a period of 2 to 2½ hours. The reaction is exothermic and controlled by the rate of formaldehyde addition. The reactor temperature is preferably kept between 100 to 120°C and it should not exceed 135°C. After all of this part of the formaldehyde is added, the mixture is held at reflux for 15 minutes. Thereafter, a commercially available resorcinol still residue known as RM-441 is preferably added in 80% solution over ¼ to ½ hour to the reactor while the reaction mixture is maintained at 80° to 100°C. About 27 grams of this solution would preferably be used for each mole of resorcinol used. This residue is a mixture of resorcinol and 3,4'-dihydroxy diphenyl; 2,4,3'-trihydroxyl diphenyl and higher molecular weight polymeric materials. Analysis of typical samples of such residue shows 2% to 8% resorcinol, 12% to 20% dihydroxy diphenyl and 25% to 35% trihydroxyl diphenyl and the higher molecular weight polymers making up the balance. RM-441 is commercially available from Koppers Company, Inc. located at Pittsburgh, Pennsylvania, U.S.A. The remainder of the formaldehyde is then added streamwise for an additional time of ½ hour while the reaction mixture is maintained at 95° to 100°C after all formaldehyde is added and the mixture is held at reflux for 15 minutes. For each mole of resorcinol used, about 0.08 moles of sodium hydroxide are then charged to the reactor. Atmospheric distillation is conducted until a temperature of 145°C is reached. A vacuum is applied to the kettle. As a vacuum is applied, the temperature will drop and the resin will foam. The rate that vacuum is applied should be controlled so that the temperature does not drop below 125°C and the resin does not foam into the vapour lines. When foaming has subsided, the vacuum should be applied in increments until full vacuum at least (95% or 952 x 10²Pa [715 mm Hg]) is maintained. Pulling vacuum too rapidly may pull resin into the vapour header and condenser, plugging the condenser. When a temperature of 160°C has been reached, vacuum is released and the kettle emptied, after which the finished resin is transported to a flaker to reduce it to about ⅛ to ¼ inch flakes. It may alternatively be broken into small pieces or ground to about 0.64 cm (¼ inch) pieces. Referring to Figure 2, the resin of the present invention may alternatively be produced by first charging water and resorcinol to the reactor. An agitator is used, and, as necessary, the addition of resorcinol is stopped briefly to allow for the mixing of water and resorcinol. If the agitator labours or stalls, heat may be put on the reactor, but the temperature of the mixture should not exceed 100°C. The resorcinol still residue 80% solution is then charged to the reactor and the mixture is heated to 100° to 120°C. A 37% formaldehyde solution is then added to the mixture during an additional time of 2 to 2½ hours. The reaction time is exothermic and is controlled by the rate of formaldehyde addition. Reactor temperature should not be allowed to exceed 135°C. The formaldehyde is added in two increments, and when all of the first amount of formaldehyde has been added to the reactor, mixing is conducted for 10-15 minutes and a sample is withdrawn for a viscosity check. A high-intensity light may be required to see the bubble. The viscosity should be 30-36 Gardner Holdt seconds at 23°C. If the results obtained are within this range, an adjustment in the second formaldehyde charge may be necessary. When all of the second amount of formaldehyde has been charged, the mixture is agitated for 10 minutes, a sample is withdrawn and viscosity checked. This result should be 40 to 85 Gardner Holdt seconds. If viscosity is not within this range, additional formaldehyde or resorcinol is added to obtain an endpoint within the acceptable range. The ideal endpoint would be 63 Gardner Holdt seconds. Reactor valves are set for atmospheric distillation, and atmospheric distillation is continued until a temperature of 110°C is reached. When the reactor temperature reaches 110°C, p-toluene sulphonic acid is charged. Styrene is then added streamwise over a period of one hour. Distillation is continued during styrene addition and styrene is retained from water styrene azeotrope while removing water. When a temperature of 140°C has been reached, the temperature is held at 140° to 145°C for 30 minutes. The kettle is switched to vacuum distillation. A vacuum is slowly applied to the kettle. As a vacuum is applied, the temperature will drop and the resin will foam. The rate that the vacuum is applied should be controlled so that the temperature does not drop below 125°C and the resin does not foam into the vapour lines. When foaming has subsided, the vacuum should be applied in increments until full vacuum (at least 95% or 952 x 10² Pa [715 mm Hg]) is maintained. Pulling the vacuum too rapidly may pull resin into the vapour header and condenser, plugging the condenser. When a temperature of 160°C has been reached, the vacuum is released and the kettle is emptied. The completed resin is then flaked, broken into small pieces or ground to about 0.64 cm [¼ inch] pieces. The process of the present invention is further illustrated by the following Examples. Example 1 440.4 grams of resorcinol was charged to a flask and heated to 125°C. 0.8 g of p-toluene sulphonic acid was then added and mixed for 10 minutes. 145 g of styrene was then charged to the flask streamwise over a period of about 1 hour, temperature being maintained at 125° to 135°C for 1 hour after all of the styrene had been added. A 37% formaldehyde solution in the amount of 220 g. was then charged to the reactor streamwise over a period of 30 minutes at a temperature of 100° to 125°C. After all the formaldehyde was added, the mixture was held at reflux for 15 minutes. 0.2 g. of 50% solution of sodium hydroxide was added and water was then removed by atmospheric distillation to 145°C and vacuum was applied and distillation continued to 160°C. When a temperature of 160°C was reached, the vacuum was released and the flask emptied. The resulting resins had a softening point of 123°C and a moisture content of 0.2%. Free resorcinol was 3.4 percent. The compound made by the reaction of resorcinol and styrene in the above-described manner was identified by infrared (IR) and proton magnetic resonance (NMR) procedures and found to have the following structure. The compound made as a product of the entire above-described procedure was analyzed by infrared (IR) and proton magnetic resonance (NMR) procedures and identified as having the following structure. This disclosed resin was compared with a silica/black control nonbonding agent and B-19S, a resorcinol-aldehyde resin rubber curing agent available from Koppers Company, Inc., Pittsburgh, Pennsylvania, U.S.A. Rheometer cur, hardness, tensile strength, adhesion and fuming characteristics were evaluated. The results of this test are shown in Table 1. Example 2 440 g. of resorcinol was charged to a flask and heated to 120-130°C. 0.7 g. of p-toluene sulphonic acid was then charged and mixed for ten minutes at 120° to 130°C. A 37% formaldehyde in the amount of 220.4 g. solution was charged over a period of 1 hour. When all of the formaldehyde was charged the flask was set for atmospheric distillation, and atmospheric distillation was continued until a temperature of 140°C was reached. When reactor temperature reached 140°C, 145.3 g. of styrene was added streamwise over a period of 90 minutes. Temperature was maintained at 135° to 140°C and held at 140° to 150°C for 1 hour after all the styrene had been added. The flask was then switched to vacuum distillation. When a temperature of 160°C was reached, the vacuum was released and the flask emptied. The resulting resin had a softening point of 122°C and a moisture content of 0.05%. Free resorcinol was 5.4%. A test similar to the one conduct on the product of the foregoing example was conducted on this product of this example. The results of this test are shown in Table 2. Examples 3-6 The procedure of Example 1 was repeated four times except the amount of styrene used was varied as is shown in Table 3. The percentage of free resorcinol and the softening points of the resulting resins were measured and are shown in Table 3. Example Styrene (g) Free Resorcinol Softening Point 3 0.00 13.5 126.6 4 145.00 3.4 15.9 5 184.8 3.1 124.7 6 206.6 1.1 121.5 Examples 7-9 The procedure of Example 1 was repeated three more times except that the 440.4 g. of resorcinol, 0.8 g. p-toluene sulphonic acid, 204 g. of 37% formaldehyde solution and 0.3 g. of sodium hydroxide were used and the amount of styrene was varied as shown in Table 4. The percentage of free resorcinol and the softening points of the resulting resins were measured and are shown in Table 4. Example Styrene (g.) Free Resorcinol (%) Softening Point (°C) 7 0.00 15.5 114.8 8 145.00 7.9 112.6 9 224.00 2.5 112.0 Examples 10-15 The procedure of Example 2 was repeated six times except the amount of styrene used was varied as is shown in Table 5. The percentage of free resorcinol and the softening points of the resulting resins were measured and are shown in Table 5. Example Styrene (g.) Free Resorcinol (%) Softening Point (°C) 10 0.00 13.5 126.6 11 60.00 9.0 127.4 12 79.2 7.4 124.8 13 110.0 5.4 122.6 14 145.2 2.6 118.7 15 149.2 1.7 117.0 Examples 16-18 The procedure of Example 2 was repeated three more times except that 440.9 g. of resorcinol, 0.8 g. of p-toluene sulphonic acid, 204.0 g. of 37% formaldehyde solution and 0.3 g. of 50% sodium hydroxide solution were used, and the amount of styrene used was varied as is shown in Table 6. The percentage of free resorcinol and the softening points of the resulting resins were measured and are shown in Table 6. Example Styrene (g.) Free Resorcinol (%) Softening Point (°C) 16 0.00 15.5 114.8 17 88.00 9.1 112.3 18 158.40 3.6 109.4 Example 19 89.9 kg [198 pounds) of resorcinol was charged to a reactor and heated to 120 to 130°C. 147 grams [0.3 pounds] of p-toluene sulphonic acid was then similarly charged and mixed for 10 minutes at 120° to 130°C. Styrene was then charged to the reactor streamwise. The resulting reaction was exothermic and was controlled by the rate of styrene addition. The addition time was about 1 hour. Temperature was maintained at 125° to 135°C for the reaction and then held at 135 to 145°C for ½ hour after all of the styrene had been added. A 37% formaldehyde solution in the amount of 40.6 kg [89.4 pounds] was then charged to the reactor streamwise. The resulting reaction was exorthermic and was controlled by the rate of formaldehyde addition. The reactor temperature was not allowed to exceed 135°C. Addition time for formaldehyde was about 2 hours. After all the formaldehyde was added, the mixture was held at reflux for 15 minutes. At 80% solution of RM-441 then was charged to the reactor streamwise in an amount of 15 kg [27.5 pounds]. Addition time was about ½ hour. An addition 5.2 kg (11.4 pounds) of 37% formaldehyde solution was then added to the reactor streamwise. Addition time was about ½ hour. After all the formaldehyde had been added, the mixture was held at reflux for ¼. 0.91 kg [2 pounds] of a 50% sodium hydroxide solution was then added and reactor valves were set for atmospheric distillation. Atmospheric distillation was continued until a temperature of 145°C was reached. The kettle was then switched to vacuum distillation. The rate that the vacuum was applied was controlled so that the temperature did not drop below 125°C and the resin did not foam into the vapour lines. When a temperature of 160°C was reached, the vacuum was released and the kettle empties. The resulting resins from several batches had a softening point of 117°-123°C and a moisture content of 0.7%. The pH of a 40% aqueous alcohol solution was 5.0-6.0. Free resorcinol was 2.5%-3.5%. Example 20 5.3 kg [9.7 pounds] of water was charged to the reactor followed by 84 kg [185.2 pounds] of technical grade resorcinol. After each 22.7 kg [50 pounds], or as needed, the addition was stopped and the agitator run briefly until the resorcinol and water were mixed after which charging was resumed. 11.7 kg [25.7 pounds] of an 80% solution of RM-441 was then charged to the reactor and the mixture was heated to 100° to 120°C. 40.6 kg [89.4 pounds] of a formaldehyde solution was then added to the reactor streamwise. The resulting reaction was exothermic and was controlled by the rate of formaldehyde addition. The reactor temperature was not allowed to exceed 135°C. Addition time for the formaldehyde was between 2 and 2½ hours. When all of the formaldehyde had been added to the reactor, it was mixed for 10 minutes and a sample was withdrawn for a viscosity check. The viscosity was between 30 to 36 Gardner Holdt seconds at 23°C. Another 2.13 kg [4.7 pounds] of 37% formaldehyde solution was then added streamwise. When all of the second amount of formaldehyde was charged, the mixture was agitated for 10 minutes. A sample was withdrawn and viscosity checked. The results were from 45-85 Gardner Holdt seconds. Reactor valves were set for atmospheric distillation and continued until a temperature of 110°C was reached. When reactor temperature reached 110°C, 0.54 kg [1.2 pounds] of p-toluene sulphonic acid were charged. 37.8 kg [83.3 pounds] of styrene were added streamwise over a period of one hour. Distillation was continued during styrene addition and styrene was returned from the water/styrene azeotrope while water was removed. Once a temperature of 140°C was reached, the reaction was held at 140° to 145°C for 30 minutes. The kettle was switched to vacuum distillation. The rate that the vacuum was applied was controlled so that the temperature did not drop below 125°C and the resin did not foam into the vapour lines. When a temperature of 160°C was reached, the vacuum was released and the kettle was emptied. The resulting resin had a softening point of 117 to 128°C and a moisture content of 0.7%. The pH of a 50% aqueous/alcohol solution was from 5.0-6.0. It has 2.5%-3.5% free resorcinol. It will be appreciated that the above-described resins are low fuming, nonhygroscopic and low in free resorcinol.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR, GB, GR, IT, LU, NL, SE A process for making a phenolic resin, for use in rubber compounding, which process comprises the steps of reacting a compound having the formula I in which X is hydroxyl, hydrogen or an alkyl group having from 1 to 4 carbon atoms, with a compound having the formula II Y - CH = CH₂ II in which Y is phenyl, hydrogen or an aliphatic alkyl group having from 1 to 4 carbon atoms, and with a compound having the formula III in which Z is hydrogen or an alkyl group having from 1 to 4 carbon atoms; and wherein the molar ratio of the compound of formula III to the compound of formula I is 0.5 to 0.8 moles to 1.0 mole. A process according to claim 1, wherein the compound of formula I is resorcinol. A process according to claim 1 or 2, wherein the compound of formula II is styrene. A process according to claim 1, 2 or 3, wherein the compound of formula III is formaldehyde. A process according to any one of claims 1 to 4, wherein the molar ratio of the compound of formula I to the compound of formula II is 1 mole to 0.25-1.0 mole. A process according to any one of claims 1 to 5, wherein the compound of formula I is resorcinol and the free resorcinol content of the phenolic resin is between 0 and 5 weight percent. A process according to any one claims 1 to 6 comprising the steps of: (a) first reacting the compound of formula I with the compound of formula II; and then (b) reacting the product of step (a) with a compound of formula III. A process according to claim 7, wherein step (a) is carried out at a temperature in the range of from 120° to 140°C. A process according to claim 7 or 8, wherein step (a) is carried out in the presence of an acid catalyst. A process according to claim 9, wherein the acid catalyst is p-toluene sulphonic acid. A process according to any one of claims 7 to 10, wherein step (b) is carried out at a temperature in the range of from 110° to 130°C. A process according to any one of claims 7 to 11, wherein resorcinol still residue and sodium hydroxide are introduced in step (b). A process according to any one of claims 1 to 6, comprising the steps of: (a) first reacting the compound of formula I with the compound of formula III; and then (b) reacting the product of step (a) with the compound of formula II. A process according to claim 13, wherein step (a) is carried out at a temperature in the range of from 100° to 120°C. A process according to claim 13 or 14, wherein in step (b), before the compound of formula II is added, dehydration at atmospheric pressure takes place from 130° to 150°C, and, after the compound of formula II is added, the reaction is completed at a temperature in the range of from 130° to 150°C. A process according to claim 13, 14 or 15, wherein step (b) is carried out in the presence of an acid catalyst. A process according to claim 16, wherein the acid catalyst is p-toluene sulphonic acid. A process according to any one of claims 13 to 17, wherein resorcinol still residue and water are introduced in step (a) and sodium hydroxide is introduced in step (b). A phenolic resin when made by the process of any one of claims 1 to 18. A phenolic resin as claimed in claim 19 wherein the compound of formula I is resorcinol, the compound of formula II is styrene and the compound of formula III is formaldehyde, whereby the phenolic resin can be represented by formula IV A phenolic resin as claimed in claim 19 or 20, having a free resorcinol content between 0 and 5 weight percent. A phenolic resin according to claim 19, wherein X, in the compound of formula I, is hydrogen or an alkyl group having from 1 to 4 carbon atoms. The use in a rubber composition of a phenolic resin as claimed in any one of claims 19 to 22. Claims for the following Contracting State : ES A process for making a phenolic resin, for use in rubber compounding, which process comprises the steps of reacting a compound having the formula I in which X is hydroxyl, hydrogen or an alkyl group having from 1 to 4 carbon atoms, with a compound having the formula II Y - CH = CH₂ II in which Y is phenyl, hydrogen or an aliphatic alkyl group having from 1 to 4 carbon atoms, and with a compound having the formula III in which Z is hydrogen or an alkyl group having from 1 to 4 carbon atoms; and wherein the molar ratio of the compound of formula III to the compound of formula I is 0.5 to 0.8 moles to 1.0 mole. A process according to claim 1, wherein the compound of formula I is resorcinol. A process according to claim 1 or 2, wherein the compound of formula II is styrene. A process according to claim 1, 2 or 3, wherein the compound of formula III is formaldehyde. A process according to any one of claims 1 to 4, wherein the molar ratio of the compound of formula I to the compound of formula II is 1 mole to 0.25-1.0 mole. A process according to any one of claims 1 to 5, wherein the compound of formula I is resorcinol and the free resorcinol content of the phenolic resin is between 0 and 5 weight percent. A process according to any one claims 1 to 6 comprising the steps of: (a) first reacting the compound of formula I with the compound of formula II; and then (b) reacting the product of step (a) with a compound of formula III. A process according to claim 7, wherein step (a) is carried out at a temperature in the range of from 120° to 140°C. A process according to claim 7 or 8, wherein step (a) is carried out in the presence of an acid catalyst. A process according to claim 9, wherein the acid catalyst is p-toluene sulphonic acid. A process according to any one of claims 7 to 10, wherein step (b) is carried out at a temperature in the range of from 110° to 130°C. A process according to any one of claims 7 to 11, wherein resorcinol still residue and sodium hydroxide are introduced in step (b). A process according to any one of claims 1 to 6, comprising the steps of: (a) first reacting the compound of formula I with the compound of formula III; and then (b) reacting the product of step (a) with the compound of formula II. A process according to claim 13, wherein step (a) is carried out at a temperature in the range of from 100° to 120°C. A process according to claim 13 or 14, wherein in step (b), before the compound of formula II is added, dehydration at atmospheric pressure takes place from 130° to 150°C, and, after the compound of formula II is added, the reaction is completed at a temperature in the range of from 130° to 150°C. A process according to claim 13, 14 or 15, wherein step (b) is carried out in the presence of an acid catalyst. A process according to claim 16, wherein the acid catalyst is p-toluene sulphonic acid. A process according to any one of claims 13 to 17, wherein resorcinol still residue and water are introduced in step (a) and sodium hydroxide is introduced in step (b). The use in a rubber composition of a phenolic resin as prepared by the process according to any one of claims 1 to 18, with a curing agent therefor.

Inventors: HOOD RICHARD T, LAMARS ROBERT M, HOOD, RICHARD T, LAMARS, ROBERT M
Applicants: INDSPEC CHEMICAL CORP, INDSPEC CHEMICAL CORPORATION
Application year: 1989
Main classification: C08G16
IPC codes: C08G16