JPS6358167B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for producing a condensation resin of p-chlorophenol or m-alkyl substituted phenols and m-cresol. More specifically, it is a method for producing a novolac-type polymer useful as an adhesive between polyester fiber and rubber, etc., by using a resol-type initial condensate of the phenols. Polyester fiber has a higher modulus of elasticity than nylon and is superior in dimensional stability, and is less prone to flat spots like nylon, so it is showing superiority over nylon as a tire cord for passenger car tires.However, it has some disadvantages. It has both. Its biggest disadvantage is that it is difficult to bond due to the structure of polyester itself. In order to solve this problem, many studies have been conducted and reported on adhesives or bonding methods. In most cases, a highly reactive compound dissolved in a solvent is attached to the fibers and dried, followed by a one-step treatment, followed by a process in which resorcinol formalin latex (hereinafter referred to as RFL) is used to attach them to the fibers and dry them.
This is a two-stage process that uses a solvent to carry out the second stage treatment, and has drawbacks such as danger from the solvent, contamination of the working environment, and complexity of the process. In contrast, water is used as a medium and adhesive and RFL
Japanese Patent Publication No. 11251/1973 and Japanese Patent Publication No. 8733/1986 are known as adhesives and bonding methods that exhibit high adhesive strength by performing one step of treatment in one bath. It goes without saying that mold adhesives do not pollute the environment due to flammability or toxicity, and that the process is simplified, efficient, and industrially useful. Compared to that, the adhesive strength is still insufficient. Regarding novolac resin using m-cresol, it is described in JP-A-51-116847 as a 2,6-dimethylol-3methylphenol condensate having 3-methylphenol at the end. There is a description of. This resin is obtained by reacting m-cresol with formaldehyde under an acidic catalyst.
There is no example of using a resol initial condensate, including other patents. Moreover, there is no example related to copolymerization of p-chlorophenol and m-cresol before the present invention. The object of the present invention is to establish a method for producing a polymer that has outstanding effects on adhesion between polyester fibers and rubber. More specifically, the objective is to establish a manufacturing method that can easily provide industrially a polymer that is dispersed in an aqueous medium and that produces sufficient adhesive strength in one bath treatment. The present inventors took these into consideration and as a result of intensive study, after converting monovalent phenols into resols, m
-We applied a method of condensation with cresol and found that although the resulting polymer was insoluble in water, a stable aqueous dispersion could be obtained by a dispersion method. The present invention was completed by establishing a method for producing a polymer that is easily industrially produced and has the highest effectiveness as a one-bath adhesive for polyester and rubber. I came to the conclusion. That is, in the present invention, in the presence of an alkali catalyst, p
-chlorophenol or general formula

[Formula] (in the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is H or CH ₃ group), and one or more phenols represented by the above phenols and 0.7 ~2.5 times the molar ratio of formaldehyde is reacted to obtain a resol-type initial condensate in which unreacted formaldehyde remains at 50% or less based on the charged amount, and then an amount equivalent to the above alkali catalyst or 10 mol% excess relative to the above phenols is obtained. A dispersible meta-cresol polymer, characterized in that the above-mentioned resol initial condensate is added to a mixture of 0.7 to 2.5 times the molar amount of m-cresol to the above-mentioned phenols, and a co-condensation reaction is carried out. This is a manufacturing method. The first feature of the present invention lies in the structure of monovalent phenols, which are the raw materials for the resol initial condensate to be condensed with m-cresol. The alkyl-substituted phenol and p-chlorophenol are industrially easily available, and the solubility parameter of the condensate with m-cresol has a structure close to that of polyester. Furthermore, in order to improve the reactivity with formalin during resolization, the alkyl group substitution position of the alkylphenol should be at the meta position, and the size of the substituted alkyl group should be selected so that it has up to 4 carbon atoms and has little steric hindrance. There is a need. These phenols include p-chlorophenol, m-cresol,
3,5-xylenol, m-ethylphenol,
m-lso-propylphenol, m-n-propylphenol, m-tert-butylphenol, m
-lso-butylphenol, m-sec-butylphenol, m-n-butylphenol are mentioned, but preferred ones are p-chlorophenol, m-cresol, 3,5-xylenol, m-ethylphenol, m- lso-propylphenol, m-
An example is tert-butylphenol. The second feature of the present invention is that when obtaining a resol-type initial condensate, the amount of unreacted formaldehyde is 50% or less based on the amount charged, preferably approximately 1 to 20%.
%. The resol-forming reaction conditions are important because they have a great influence on the performance of the resorcinol copolymer, which is the final target product, particularly on the adhesive performance. Generally, this reaction generates a large amount of heat, and the resol-type initial condensate is unstable to heat. If the reaction is allowed to proceed too much, that is, when unreacted formaldehyde becomes less than 1% of the charged amount, a benzyl ether-type compound is formed due to a dehydration reaction. Undesirable side reaction products such as these are likely to be produced. On the other hand, if the reaction conditions are too mild, for example, if the amount of unreacted formaldehyde exceeds 50% of the charged amount, the unreacted formaldehyde will react with m-cresol during the novolacification reaction, and the proportion of the novolac copolymer similarly sought will decrease. This results in a decrease in performance as an adhesive.
In order to avoid this, in the method of the present invention, the reaction is controlled so that the amount of unreacted formaldehyde remains within the above specified range. Regarding the reaction temperature, 20° to 100°C, preferably
A range of 40° to 90°C is suitable. Specifically, this temperature needs to be appropriately selected depending on the combination of other conditions, such as the type of phenol used, the amount of catalyst, and the reaction time. For example, the reaction generally tends to proceed at lower reaction temperatures in the order of p-chlorophenol, m-tert-butylphenol, m-ethylphenol, m-cresol, and 3,5-xylenol. If the amount of catalyst is increased, the reaction temperature can be lowered, and the reaction temperature will naturally affect the reaction time, but for process control purposes, it will take 1 to 24 hours, preferably 2 hours.
It is preferable to select the temperature so that the heating time is about 10 hours. The third feature of the present invention is that the above-mentioned phenols are condensed with m-cresol. High purity m-cresol is easily available at low cost. The fourth feature of the present invention resides in a method of condensation reaction between the resol initial condensate and m-cresol. Generally, acid and m-cresol are added to the resol liquid to perform novolacification, but although this method has the advantage of being able to be done in a single container, it also causes the side reaction of novolacification between the resol initial condensates due to acid addition. As it occurs,
Since the condensation reaction proceeds all at once, complicated operations such as gradually raising the reaction temperature are required for reaction control, and this involves risks. The method of the present invention is characterized in that a mixture of an alkaline catalyst, an equivalent amount or a 10 mol% excess of acid relative to the phenol used, and m-cresol is gradually reacted with the resol type initial condensate. be. In other words, in the conventional method in which a mixture of acid and m-cresol is suspended in water and added to the resolization reaction solution, the resol-type initial condensate itself changes due to heating until the reaction is completed; The various problems mentioned above can be solved all at once by the reverse method of adding the resol-forming reaction liquid to the mixture. The added resol-type initial condensate can be used after being cooled if necessary, and has the advantage that progress of deterioration over time can be suppressed. The molar ratio of formaldehyde to the phenols used in the present invention is important to obtain a copolymer with a preferable molecular weight distribution, and it is preferable to use a molar ratio of 0.7 to 2.5 times the molar ratio of formaldehyde to the phenols.
A molar ratio of ~2.2 times is particularly preferred. The molecular weight distribution is measured by gel permeation chromatography (hereinafter referred to as GPC), and based on the waveform and actual adhesive strength, the average molecular weight is in the distribution range of 200 to 1500, preferably 250 to 800. be. Furthermore, the amount of m-cresol used in the present invention is
The amount is preferably 0.8 to 1.2 equivalents per equivalent of methylol group of the resol type initial condensate, and the amount of the phenols
The molar ratio ranges from 0.7 to 2.5 times. Since a considerable portion of the formaldehyde used reacts, the number of methylol groups in the resol initial condensate formed and m used
- It is possible to obtain a polymer in which the number of cresols is approximately equal and m-cresol is located at the end by a condensation reaction. Known alkali catalysts can be used, and hydroxides or carbonates of alkali metals or alkaline earth metals are used. The amount of catalyst is in the range of 0.2 to 20 mol%, preferably 0.5 to 10 mol%, based on the phenols. Further, although the resolization reaction is carried out in an aqueous solvent system, it can also be carried out in a system in which other organic solvents are used in combination. In this case, it is preferable to use a solvent that can dissolve the raw material phenols and also dissolve the generated resol-type initial condensate. Examples include aliphatic alcohols such as methyl alcohol and ethyl alcohol, aliphatic ketones such as acetone and methyl ethyl ketone, etc. can be given. The acid catalyst used in the condensation reaction is used in an amount equivalent to the alkali catalyst used above or in an excess of 10 mol %, preferably 0.3 to 3 mol %, relative to the phenols, and may be any of the known hydrochloric acid, sulfuric acid, nitric acid, formic acid, oxalic acid, acetic acid, p -Toluenesulfonic acid etc. can be used. Since the amount of catalyst used remains in the produced resin, it is desirable to use as little as possible. In the co-condensation reaction, a small amount of water is added to suspend m-cresol, but other solvents may also be used in combination. When using the polymer produced in this way as an adhesive, the remaining monomers can be removed by known separation methods such as distillation or extraction to form a fusible resin, which is then made into an aqueous dispersion. desirable. Thus, the polymer produced by the method of the present invention has extremely superior properties in terms of adhesive performance, ease of handling, etc. compared to those produced by conventionally known methods, and the industrial value of the present invention is high. be. Adhesive performance is measured by Imperial Chemical Industries Limited (ICI), which is widely used for rubber-polyester fibers as a one-bath adhesive.
It is an aqueous dispersion that is much superior to Valkabond E manufactured by Co., Ltd., and is also stable in terms of handling, and is fully suitable for the purpose of the present invention. There is also no problem with storage stability since it is a novolak type resin. The polymer produced by the production method of the present invention is most characteristically used in an adhesive treatment solution for polyester fibers.
That is, it is used by mixing it with so-called RFL, which is a mixture of an alkaline initial condensate of resorcinol and formaldehyde and rubber latex. As is well known, RFL generally consists of 1 to 4 moles of formaldehyde per 1 mole of resorcinol.
One or more types of vinyl pyridine-styrene-butadiene latex, styrene-butadiene latex, polybutadiene latex, natural rubber latex, etc. are produced by condensation under an alkali catalyst such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide. obtained by mixing. Each of the two components present in the adhesive treatment liquid has a polymer solid content of 30 to 50% of the total adhesive solids weight of 100%,
RFL is preferably 50-70. The polyester fibers are immersed in the adhesive treatment solution or coated with an adhesive by other suitable means,
Then, it is heat treated at a temperature in the range of 200°C to 250°C, and the treated cord is embedded in unvulcanized rubber and vulcanized and bonded. Hereinafter, examples will be given to explain the manufacturing method of the present invention, and comparative examples will be given to explain the manufacturing method of the present invention and for comparison.
Further, referring to reference examples, the results of evaluation of adhesive strength using each of the produced polymers as an adhesive between polyester fiber and rubber will be explained in detail. Furthermore, in the text, parts refer to parts by weight unless otherwise specified. Example 1 While stirring 257 parts of p-chlorophenol with 500 parts of water and 8 parts of caustic soda in a 2000 ml four-necked kolben, 324 parts of a 37% formalin aqueous solution was boiled over 3 hours at a temperature of 80°C. Made and dripped. Stirring was continued for another 2 hours at the same temperature, and when the amount of unreacted formalin reached 10% of the charged amount, the mixture was cooled to 25°C and 500 parts of ethyl alcohol was added to form a homogeneous liquid, and the reaction was stopped. Next, add 432 parts of m to a 3,000 ml separate flask.
-Cresol, 500 parts of water, and 12.5 parts of oxalic acid were charged, and the above p-chlorophenol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, water and ethyl alcohol in the system were removed, unreacted m-cresol and p-chlorophenol were removed by vacuum distillation, and p-chlorophenol-m -Cresol-formadehyde resin (A) 753 parts were obtained. The above resin is a reddish brown solid with 90%
It was a fusible oligomer with a softening point of °C and an average molecular weight of 580. Example 2 257 parts of p-chlorophenol was mixed with 500 parts of water and 8 parts of caustic soda in a 2000 ml four-necked kolben at a temperature of 80° C. while stirring at a temperature of 283.5 parts of 37%.
An aqueous formalin solution was slowly added dropwise over a period of 3 hours. Stirring was further continued at the same temperature for 2 hours, and when the amount of unreacted formalin reached 9% of the charged amount, the mixture was cooled to 25°C and 500 parts of ethyl alcohol was added to form a homogeneous liquid, and the reaction was stopped. Next, add 378 parts of m to a 3000 ml separable flask.
-Cresol, 430 parts of water, and 12.2 parts of oxalic acid were charged, and the above p-chlorophenol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, water and ethyl alcohol in the system were removed, unreacted m-cresol and p-chlorophenol were removed by vacuum distillation, and p-chlorophenol-m -Cresol-formadehyde resin
(B) 688 copies were obtained. Example 3 216 parts of m-cresol was stirred with 250 parts of water and 1.6 parts of caustic soda in a 1000 ml four-necked Kolben at a temperature of 50°C, and 324 parts of a 37% formalin aqueous solution was slowly prepared over 3 hours. dripped. Stirring was further continued for 2 hours at the same temperature, and when the amount of unreacted formalin reached 10% of the charged amount, the reaction was stopped by cooling to 25°C. Next, add 432 parts of m to a 2000 ml separable flask.
-Cresol, 500 parts of water, and 5 parts of oxalic acid were charged, and the above m-cresol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, the water in the system was removed, and unreacted m-cresol was removed by vacuum distillation.
702 parts of cresol-formadehyde resin (C) was obtained. Example 4 150 parts m-tert in a 1000 ml four-necked Kolben
-While stirring butylphenol with 250 parts of water and 20 parts of caustic soda, 121.6 parts of a 37% aqueous formalin solution was slowly added dropwise at a temperature of 70°C over 3 hours. Stirring was further continued at the same temperature for 2 hours, and when the amount of unreacted formalin reached 15% of the charged amount, the mixture was cooled to 25°C, and 200 parts of ethyl alcohol was added to form a homogeneous liquid, and the reaction was stopped. Next, add 162 parts of m to a 2000 ml separable flask.
-Cresol, 200 parts of water, and 6.2 parts of oxalic acid were charged, and the above m-tert-butylphenol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, water and ethyl alcohol in the system were removed, and unreacted m-cresol and m-tert-butylphenol were removed by vacuum distillation.
332 parts of tert-butylphenol m-cresol-formadehyde resin (D) was obtained. Example 5 244 parts of 3,5- in a 2000 ml four-necked Kolben
While stirring xylenol with 340 parts of water and 4 parts of caustic soda, 324 parts of a 37% formalin aqueous solution was slowly added dropwise at a temperature of 50°C over 3 hours. Stirring was further continued at the same temperature for 2 hours, and when the amount of unreacted formalin reached 4% of the charged amount, the mixture was cooled to 25°C, and 250 parts of ethyl alcohol was added to form a homogeneous liquid, and the reaction was stopped. Next, add 432 parts of m to a 3000 ml separable flask.
-Cresol, 500 parts of water, and 7.9 parts of oxalic acid were charged, and the above 3,5-xylenol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, water and ethyl alcohol in the system were removed, and unreacted m-cresol and 3,5-xylenol were removed by vacuum distillation. -m-cresol-formadehyde resin
(E) Obtained 731 copies. Example 6 108 parts of m-cresol and 122 parts of m-ethylphenol were added in a 1000 ml four-necked Kolben.
While stirring with 250 parts of water and 1.6 parts of caustic soda, 324 parts of a 37% formalin aqueous solution was slowly added dropwise over 3 hours at a temperature of 60°C. Stirring was further continued at the same temperature for 2 hours, and when the amount of unreacted formalin reached 7% of the charged amount, the reaction was stopped by cooling to 25°C. Next, add 432 parts of m to a 2000 ml separable flask.
-Cresol, 500 parts of water, and 5 parts of oxalic acid were added, and the above m-cresol was mixed with stirring at 70℃.
The m-ethylphenol-formalin reaction solution was slowly added dropwise over 3 hours. After further stirring at the same temperature for 3 hours, water in the system was removed, unreacted m-cresol and m-ethylphenol were removed by vacuum distillation, and m-cresol-m-
Ethylphenol-formaldehyde resin (F)704
I got the department. Comparative Example 1 In a 2000 ml four-necked Kolben, 324 parts of p-chlorophenol was stirred with 500 parts of water and 8 parts of caustic soda at a temperature of 60°C.
A 37% formalin aqueous solution was slowly added dropwise over 3 hours. Stirring was further continued at the same temperature for 2 hours, and when the amount of unreacted formalin reached 35% of the charged amount, the mixture was cooled to 25°C and 500 parts of ethyl alcohol was added to form a homogeneous liquid, and the reaction was stopped. Next, add 432 parts of m to a 3000 ml separable flask.
-Cresol, 500 parts of water, and 12.5 parts of oxalic acid were charged, and the above p-chlorophenol-formalin reaction solution was slowly added dropwise over 3 hours while stirring at 70°C. After further stirring at the same temperature for 3 hours, water and ethyl alcohol in the system were removed, and unreacted p-chlorophenol and m
-Cresol was removed by vacuum distillation to obtain 730 parts of p-chlorophenol-m-cresol-formaldehyde resin (G). Reference Example 1 The polymer resin obtained in the above Examples and Comparative Examples was used as an adhesive between polyester fiber and rubber, and the results of evaluating the adhesive force thereof will be explained below along with the test method. (a) The adhesive treatment liquid was obtained by mixing 40 parts of polymer aqueous dispersion and 60 parts of RFL. The polymer aqueous dispersion is anionic surfactant Demol SSL (manufactured by Kao Atlas Co., Ltd.)
15% solids dispersed in water using a laboratory sand grinder. RFL consists of water, 635.5 resorcinol, 20.5, 37% formaldehyde, 18, 5% caustic soda aqueous solution, 32 vinylpyridine latex (41%), 294 and is an aqueous dispersion with a solid content of 15%. (a) Unvulcanized rubber consists of the following composition: Smoked sheet 30 parts Styrene-butadiene rubber 70 Carbon black 40 Stearic acid 1.5 Process oil (petroleum) 5 Zinc Flower 5 N-phenyl-β-naphthylamine 1 Benzothiazyl disulfide 0.8 Diphenylguanidine 0.2 Sulfur 2 ) Polyester fiber tire cord is 1500d/2 as polyester fiber (number of twists is 4).
0/10 cm and the number of first twists was 40/10 cm). (d) Treatment method The polyester fiber tire cord (c) was immersed in the above adhesive treatment solution (a) and heat treated at 240°C for 2 minutes at a fixed length. (e) Test method The processing code obtained by the above processing method (d) was buried in unvulcanized rubber (a) of the above composition and heated at 145°C with 100kg/
The adhesive strength was measured by H test at room temperature after vulcanization for 30 minutes under a pressure of cm ² . (F) The measurement results of adhesive strength are shown in Table 1. It is clear from this table that the adhesive strength of the copolymer produced by the method of the invention is much better than that of the known copolymer (Comparative Example 2). Furthermore, if unreacted formaldehyde, which is out of the scope of the method of the present invention, remains, the adhesive strength is significantly reduced (Comparative Example 1).

【table】

Claims (1)

[Claims] 1. In the presence of an alkali catalyst, p-chlorophenol or the general formula [Formula] (wherein R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ represents H or CH ₃ group) One or more of the phenols shown and 0.7 to 0.7 to the above phenols.
A resol-type initial condensate was obtained by reacting formaldehyde at a molar ratio of 2.5 times to obtain a resol-type initial condensate in which unreacted formaldehyde remained at 50% or less based on the charged amount, and then an amount equivalent to the above-mentioned alkali catalyst or an excess of 10 mol% relative to the above-mentioned phenols was obtained. A dispersible meta-cresol polymer characterized by adding the above-mentioned resol initial condensate to a mixture of acid and m-cresol in an amount of 0.7 to 2.5 times the mole of the above-mentioned phenols, and causing a condensation reaction. Production method.