JPS61243040A - Hemiformal of phenol - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention #J relates to a reaction product of formaldehyde and phenol in which a reaction occurs between formaldehyde and the hydroxyl group of phenols to form hemiformal. More particularly, the present invention relates to hemiformals of phenol that are stable and can be stored for extended periods of time. All liquid hemiformals that are curable to phenolic resins are contemplated when utilized with conventional phenol-formaldehyde curing catalysts.

Speculation has been made in the literature for some time regarding the production of hemiformals of phenol.

An example of this difficult literature is Reinhold Publish
Formaldehyde, 3rd edition, published by New York, 1964).
05, page 306 (by Walker), which states: ``In the absence of added catalyst, anhydrous formaldehyde and free formaldehyde react, although the reaction is not apparent.
Dissolves in molten phenol to produce a clear colorless solution with a strong odor of formaldehyde. In such a solution, some solvation probably occurs and the 06H500H20H
, C6H50CH20CH20H and other hemiformals are thought to exist. However, studies of formaldehyde polymers suggest that phenol is the solvent for the compounds of Ton et al., and that most of the dissolved formaldehyde in the phenol solution is in the polymerized state. Hydroxy ion #I in dilute alkaline formaldehyde aqueous solution in the presence and absence of sodium ferulate of Meditol! F'itgeral including degree measurements
d, J.S., and Martin, R.J.
Study by L. (Au5tra anJ, Ohe
M, 8.194-214 (1955)) points out that the concentration of hemiformal is too low to be measured by this method. However, in the authors' opinion, the formation of hemiformals with hindered phenols such as meditol is analogous to the formation of hemiformals with tert-butyl alcohol, which does not exhibit any appreciable solvation of formaldehyde. There are clearly similarities between non-aqueous solutions of phenol formaldehyde and formaldehyde solutions in alcohols and other polar solvents. R
eychJer A, (8ull Sot, Oh
im, (4) 1.1189-95 (1907)
, Ohem, Abs, vol. 2, p. 1266 (190
8) Add a small amount of sodium alcohol to Lt″L,
It catalyzes solutions of linear formaldehyde polymers in phenol, just as sodium alcoholates catalyze solutions of methanol, ethanol, and other alcohols. It has also been suggested that hemiformal can be produced by isolating methylphenyl formal from the acid catalytic reaction of phenol with a methanol-containing formaldehyde solution [Rreslauer R J, author.

Pictel, A. Berichte, 40.3789
(1907): ].

One of the difficulties with the conclusions raised in the Walker article is that hemiformal is formed from the acid catalytic reaction of phenol with a methanol-containing formaldehyde solution. The acid acts to catalyze the reaction between phenol and formaldehyde, resulting in the usual alkylation of phenol with formaldehyde.
It is well known to produce Knoll m IIW'. 〃
1. Therefore, Walker's proposal for the existence of hemiformal is nothing more than a known reaction.

This known reaction is the reaction of methanol with formaldehyde in the presence of an acid catalyst, and the resulting product is then reacted with phenol to yield an ether product characterized as the final product of the reaction. It is something. In fact, the reaction between formaldehyde and 7-enol to produce hemiformal produces an equilibrium reaction, which is completely absent from the reaction characterized by Walker.

This means that in the theoretical reaction proposed by Walker,
This again suggests that first the formaldehyde is stabilized with methanol and then the product reacts with phenol.

Bakerind and Render n “Indu
trial and Engineering Ohe
In an article in Mistry J Vol. 17, No. 3, pp. 225-237 (1925), the following theory regarding the theoretical formation of hemiformal of phenol is stated.

``Phenol first associates directly with aldehydes to form mixed ether/alcohol encounters (XXXI[I)t-, and the resulting ether group rearranges very rapidly to become phenol.

('In) CX)Oα)' (XXXV)
(XXXVT) Thus, Bakel
andRender clearly points out the following. That is, hemiformal, if present, is at best a fleeting substance, unstable under the conditions in which it was produced, and at best a theoretical composition that forms an intermediate in the production of phenolic resins. be.

8 Trupinskaya et al. Plant, Ma.
(1968 (12)), pages 18-20, give a complete description of the preparation of the product by adsorption of formaldehyde into molten phenol in a formaldehyde to phenol ratio of 3:10. This ratio corresponds to a formaldehyde to phenol molar ratio of 0.94:1.

The formaldehyde source was a converter gas stream containing about 10% methanol, and analysis of the product showed it to contain up to 8% methanol.

In the presence of methanol, this reference (Plast, Ma
A methanol-stabilized product similar to that disclosed in the above-cited Walker paper mentioned in sa) is speculated;
That is, it is believed that formaldehyde reacts with methanol and then with phenol to form an ether product. Also, hemiformals with a high average formaldehyde to phenol ratio, one step higher than Hl at a low formaldehyde to phenol ratio, are unlikely to be formed in this process.

Belgian Patent No. 66 issued November 16, 1965
Specification No. 7360 (Ohemische WerkeH
Uels A, G, ) disclose the treatment of various hydroxy compounds, including phenol, with monomeric formaldehyde at a formaldehyde to phenol ratio of 1:1. At low formaldehyde to phenol ratios, the hemiformals formed do not contain on average more than one formaldehyde moiety in the hemiformal chain structure. Bakerand OLPiR quoted above
It is known in the art that hemiformals are transient or unstable species, and become increasingly unstable as the length of the hemiformal chain increases, as disclosed in the paper by Ender. This is to be expected by those skilled in the art.

Therefore, the additional formaldehyde added to the Huels method does not form a hemiformal with a higher ratio of formaldehyde to phenol, but rather reacts with the phenol at other positions on the aromatic ring, e.g. at the para or ortho position. is expected.

Accordingly, one skilled in the art would expect that hemiformal chains with more than one formaldehyde moiety are unstable in hemiformal compositions having formaldehyde to phenol ratios greater than 1:1;
Other 7 enol/formaldehyde resin products are formed or dissociated to form free formaldehyde.

In its constituent aspects, the present invention firstly produces a hemiformal of phenol having an average molar ratio of formaldehyde to phenol moieties as large as 1↓, and this hemiformal has cognitive stability; It has been established that it is isolable, storable and can be utilized for the formation of various products, one of which is, of course, phenol formaldehyde resin. Previous attempts to establish the formation of this hemiformal of phenol have not been successful, and no known methods for establishing the de facto existence of this hemiformal of phenol have been disclosed in the literature. Not yet.

Canadian Patent Application No. 417716-9 (G, erod
e and 8. Ohow K Engineering December 1, 1982
(Application filed on May 5) discloses a hemiformal of methylol f hyphenol, in which formaldehyde reacts with the methylol group in addition to the phenolic hydroxyl group of phenol to form hemiformal 7.

Canadian Patent Application No. 417715-1 (G, erod
e and S, Chow Ic L 1982 12
(filed on May 15th) ↓ and Canadian patent application cylinder 418533-
No. 1 (G, Brode + S, Ohow work lol
, filed December 23, 1982 by Hale)
These applications disclose the use of various hemiformals of phenol in thermosetting arsenic solutions and the use of this solution in the formation of TFFL fiber reinforcement. The present invention illustrates the use of hemiformal phenols to form useful thermosetting products.

The hemiformal of the present invention is a curable yet stable composition, typically having good stability at temperatures between about 35°C and about 55°C. In fact, this material can remain in storage for a considerable period of time between about 35°C and about 55°C.
The range of F to low temperatures to 7'C can even be maintained at high temperatures. However, when kept at lower degrees, formaldehyde tends to separate from the product at various concentrations resulting in the formation of formaldehyde crystals. At temperatures above 55°C, there is an increased possibility of loss of formaldehyde from the hemiformal structure, which is typically in the ortho position to the formal structure leading to the formation of phenol/formaldehyde resin based structures. c is the ξ position, which can be effective for reacting with the benzene ring. The rate at which this occurs depends, of course, on the temperature at which the hemiformal is stored; at higher temperatures, a reticulated product with a phenol/formaldehyde structure will form more rapidly.

Formaldehyde separates into a formaldehyde-based structure at temperatures lower than 35°C, but the product
The clear hemiformal product can be reverted by returning to a temperature of 5°C to about 55°C. Therefore, products stored at lower temperatures where crystallization or precipitation occurs are utilized in their most effective form by bringing them to moderate temperatures of about 35°C to about 55°C. and the products of the invention can be achieved.

The hemiformal of the present invention is a liquid material having a very low viscosity, such as about 20 to 100 centipoise (Brookfield), when measured at about 35°C to about 55°C. Generally, the viscosity is about 75 centipoise at 35°C.

The hemiformal of the present invention is represented by the following formula (1). In the above formula (1), nt! n is a positive number greater than 1, preferably greater than 1 and less than about 5, most preferably n has an average value of about 1.2 to about 2.5. With respect to the above ranges for n, it must be understood that these numbers constitute average values of n, and that the hemiformals of the invention are typically mixtures of different molecules with varying values of n. I understand that there is something.

In addition, the present invention provides the above hemiformal (see formula ■)
It includes the use in combination with other hemiformals having an amount of up to about 50 molar based on the total weight of the composition.

In the above formula (ID, n is as defined above.

R is any monovalent substituent typically used in connection with phenolic structures, and X has a value of 1 to about 3. R is preferably a monovalent group, such as alkyl having about 1 to about 18 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, and aromatic ring having 1 to about 3 carbon atoms. Aryl containing from 1 to about 18 carbon atoms, aralkyl, alkaryl, alkoxy containing from 1 to about 18 carbon atoms, aloxy containing from 1 to 3 aromatic nuclei, halides such as chlorine, bromine, fluorine and iodine, from 1 to about 18 carbon atoms , aryl fulfites having 1 to about 3 aromatic nuclei, and the like. The hemiformal of formula (1) should in a preferred embodiment not exceed the molar a degree of the hemiformal of formula (2). 2… no Hemiho A/”f −/l/ f,
One of the advantages of utilizing the hemiformal of Formula 1 in combination is that the hemiformal of the spinner (Formula II) tends to change the properties of any resulting phenolic resin derived from the combination of the two. The change in properties of 27λ is of a type that takes into account the maximum variety of phenolic resin products. For example, halogen substitutes increase the flame retardancy of the resulting phenolic resin. Aryl/alkyl substituents that also contain hydroxyl groups, e.g. bisphenol A
diphenols, such as bisphenol, have an additional 7-enolic hydroxyl group, which is useful for hemiformal production. Preferably, the substituted phenolic hemiformal shown in 2H has at least one functional group blind, i.e. at least both ortho positions , or the ortho position and the nosola position are open.This n is taken into consideration that a crosslinking reaction occurs when the hemiformal of the present invention is hardened.As specified above as R The various substituents in , 2 and 2 impart properties expected in conventional phenolic resin chemistry to the final resin product formed by co-reaction of the hemiformal of 2H with the hemiformal of formula I. .

Oil modified A7 such as linseed oil or castor oil modified phenol'
1-/- such derived substituted hemiformal mixed voices are also contemplated. These modified phenols are produced by reacting phenol and oil in the presence of an acidic ion exchange resin.

It is well known that modified phenols consist of complex mixtures containing phenol and various substituted phenols derived from the reaction of the phenol with unsaturation sites in the carbon chain of the alcohol. The resulting substituted or modified phenol mixture can then be treated with formaldehyde as described herein to produce a hemiformal mixture.

When making hemiformal mixtures using oil-modified phenol, at least 50 mole percent of the phenol used should be unreacted with the oil. The above class of hemiformals is produced by passing gaseous formaldehyde through liquid phenol. Liquid phenol means molten phenol or phenol dissolved in a solvent that is non-reactive with phenols and aldehydes. Preferably ha.

Use molten phenol. The molten phenol may be phenol itself, or may be phenol substituted with R as shown in formula H above. The substituted phenols or hemiformals obtained therefrom may be solid at the reaction temperature. In such cases, a non-reactive solvent may be used to form the liquid solution. gaseous formaldehyde.

Can be obtained from many sources. A preferred method for producing gaseous formaldehyde is to thermally decompose Nogura formaldehyde to form formaldehyde.

This formaldehyde is then passed through molten phenol in the absence of water. Another method of producing gaseous formaldehyde involves the oxidative decomposition of methanol to directly obtain the as-produced formaldehyde.
This method involves introducing formaldehyde into molten phenol in the absence of water.

In the reaction between formaldehyde and molten phenol, the temperature at which phenol melts, e.g.
C. to about 75.degree. C., preferably from about 45.degree. C. to about 60'C.

As mentioned above, it is desirable that the formaldehyde contain no water. However, it is quite difficult to obtain formaldehyde that does not contain water, and water is usually introduced into the formaldehyde that is subjected to the reaction. Typically, the amount of water permissible in the practice of this invention is up to about 15 parts water in association with the hemiformal, based on the total weight of the hemiformal composition! This is the amount of water that makes up 1 degree. In a preferred embodiment, the amount of water present in the produced hemiformal desirably does not exceed about 5% by weight, based on the total weight of the hemiformal composition.

The reaction need not be carried out in the presence of a catalyst; in preferred embodiments, the reaction is carried out in the absence of a catalyst. The absence of typical acidic or basic catalysts utilized in the reaction of heptenols and formaldehyde to produce resin structures adversely affects the formation of hemiformals, so the absence of these catalysts in the reaction is highly preferred. The reaction between gaseous formaldehyde and molten phenol is carried out with stirring to provide intimate mixing of the reactants and to ensure uniform reaction.

The reaction may be carried out below atmospheric pressure or above atmospheric pressure; however, in the usual case, the hemiformal reaction is carried out under atmospheric pressure conditions.

The reaction of formaldehyde and phenol to produce hemiformal is a slightly exothermic reaction that requires little temperature control to produce the desired product.

As previously pointed out, the hemiformal of the present invention is a stable material. This means that at temperatures from 35 DEG C. to about 55 DEG C., the formaldehyde present in the hemiformal moiety substantially reacts with the aromatic portions of the hemiformal moiety to form a phenolic resin-like structure. for example,
The data indicate that at a temperature of about 35° C., only 0.04 molar concentration of formaldehyde present in the hemiformal structure reacts after 24 hours.

Increasing the temperature to 55°C results in an increase in the reaction rate.

The liquid hemiformal of the present invention of formula (1) may be catalyzed by any one of the various acids or base catalysts typically used in the production of phenolic resins, either alone or in combination with the hemiformal of formula (H) above. It can be easily converted into a phenolic resin by using it. It may be desirable to add phenol to the hemiformal composition to adjust the formaldehyde to phenol ratio for a particular resin composition.

The addition of 7 enols to the hemiformal composition balances the ratio of formaldehyde to phenol, thereby increasing the novolac mass. C can produce any resin composition as a resol. In this case, each formal moiety present in the hemiformal constitutes a total equivalent of formaldehyde molecules. Thus, from the formaldehyde concentration of the hemiformal, it is possible to precisely determine which type of phenolic resin one wishes to produce by simply adding or not adding phenol. Since hemiformal is extremely reactive in the presence of a catalyst,
There is no need to apply heat when producing phenolic resin from hemiformal. By simply adding a catalyst to the hemiformal, with or without phenol, polymerization occurs to produce the desired phenolic resin.

The present invention is not intended to be limited in any way to the following examples.

Example 1 A liquid hemiformal of phenol was produced by the following procedure.

Monomeric formaldehyde was generated by thermal decomposition of paraformaldehyde as follows. That is, mineral oil 5
A 7C:2 liter flask equipped with a stirrer, thermometer, gas inlet and outlet tubes was charged with 200 f of commercially available formaldehyde (formaldehyde, grade 91). This mixture t- under nitrogen atmosphere, 120
Heated at 140°C. The gaseous formaldehyde formed was purified by passing a nitrogen stream through a heated connecting glass tube into a cold trap (-20°C) and then fed to 400 t of molten phenol. The temperature of molten phenol! f was about 40-60°C. An additional K100F of formaldehyde was added to the mineral oil when it was consumed in thermal decomposition. The product was a hemiformal of phenol as described above. The effective amount of formaldehyde from hemiformal was determined as follows. That is, about 1-1.5 f'i of hemiformal was stirred into about 75 f'i of methanol and adjusted to a pH of 4.0.

1 normal (1k) hydroxylamine salt solution (75
-) this too! The mixture was added to a methanol solution at pH 4.0 and reacted for about 1 hour. This solution was then standardized at 0.5
It was titrated to pH 4.0 with N sodium hydroxide.

This generated hemiformal contains formaldehyde as its 34
．． It was found that the content was equivalent to 4%+7;).

This is equivalent to a formaldehyde to phenol ratio of 6:1.

Example 2 A hemiformal consisting of a mixture of hemiformal of phenol and hemiformal of substituted phenol (cresol) was produced by the following procedure.

Formaldehyde generated by the method described in Example 1 was absorbed into a mixture of p-cresol (54F) and phenol (141F) at 40-60°C. The resulting mixed hemiformal was analyzed in the same manner as in the example and found to contain formaldehyde equivalent to 34.7% of the molar ratio of 0H20/(phenol + p-cresol) of 1.73:1. I found out that there is.

Example ■ This example illustrates the production of hemiformal oil-modified phenol.

ProductionIn a three-necked flask equipped with a stirrer, linseed oil 69.5
f, phenol 188f and acid type ion exchange resin [Amberlis] A-15 (trade name)] 2ft-150
Linseed oil modified phenol was prepared by mixing for 4 hours at °C. The ion exchange resin was then removed from the linseed oil modified phenol by filtration.

Gaseous formaldehyde was produced in the same manner as in the above example,
It was fed into modified phenol at 45-65°C. The resulting hemiformal was analyzed as in Example 1 above and was found to contain equivalents of 27% formaldehyde, corresponding to a formaldehyde to modified phenol molar ratio of 1.6 and 21.

b) Production of hemiformal from tung oil-modified phenol In a three-necked flask equipped with a stirrer, ? ! Soft oil s2t, phenol 188f and lactic acid type ion exchange resin (Amberlis)
A-15) Castile oil modified phenol was produced by mixing at 188fk100tl for 3 hours.

To produce hemiformal, gaseous formaldehyde produced as in Example 1 was fed into modified phenol at 45-65°C. The hemiformal of the resulting cut oil-modified phenol was analyzed in the same manner as in Example 2.
It was found to contain 40 thiformaldehyde equivalents, corresponding to a formaldehyde to modified phenol molar ratio of 7:1.

Example■ This example shows the hemiformal of phenol.

The present invention is intended to illustrate that it can be used in thermosetting compositions that are hardened to form a complete composite.

A solution of the hemiformal of Example ① and the aromatic polyester described below was heated to 60 to 70°C.
The solution was prepared by stirring vigorously at 100° C. and then adding the above ester at 60-70° C. for 1 hour to form a solution containing 29.4% by weight of polyester.

The polyester contains 31.25 f (0.3 f mol) of neopentyl glycol and 152.3 f (0.759 f mol) of isophthaloyl chloride in 3 L of anhydrous trichlorobenzene.
mol) and terephthaloyl chloride 50.769 (mol)
A mixture of 0.259 mol) Eri was prepared by stirring at reflux temperature. The liberated hydrogen chloride was stripped from the reaction mixture by a stream of nitrogen. When the release of hydrogen chloride is completed, which takes about 2 to 3 hours, bisphenol-A
I 71.3 f (0.75 mol)'t was added. Heating and dissipation to nitrogen was continued until no more hydrogen chloride was evolved. This solution was cooled and the polyester recovered by coagulation in methanol had a reduced viscosity (in p-chlorophenol at 50°C) of 0.2 dllf,
yc.

The aromatic polyester formed by oxidation had a phenol moiety at the terminal position.

1.8 parts by weight of hexamethylenetetramine, based on the total weight of the solution, was mixed with the hemiformal/polyester solution to act as a catalyst for the release of ammonia.

This mixture was then mixed with reinforcing glass fibers. This glass fiber is a non-woven glass mat, P PG
Industries Inc.

(Commercially available as type AKM from Bitsparken, Pennsylvania, USA.

The glass content was 30 parts by weight based on the total weight of the cured composite. Boil the above mixture for about 15 minutes at about 60-160℃
C. to form a partially cured tack-free composition 7c (Stage B). Then.

This partially cured composition was charged to a gold mass at 140-150°C for 45 minutes to obtain a fully cured composite.

Patent applicant: 3 easy on, carbide, corporate seal, +------ffi

Claims (1)

[Claims] 1. Formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, n is a positive number greater than 1) and is stable between about 35°C and about 55°C A liquid hemiformal of phenol, which is characterized in that it is curable to a phenolic resin in the presence of a phenol/formaldehyde curing catalyst. 2. The liquid hemiformal according to claim 1, wherein n is a positive number greater than 1 and less than about 5. 3. The liquid hemiformal of claim 1, wherein n is a positive number between about 1.2 and about 2.5. 4.Formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼Hemiformal of phenol with (I) and formula: ▲Mathematical formula,
Chemical formulas, tables, etc.▼(II) (In the formula, n is a positive number greater than 1, m is a positive number greater than 1, x has a value of 1 to about 3, and R is a monovalent is a group of formula (II), at least two of the ortho or para positions to the -O(CH_2)_mH group in the hemiformal of formula (II) are spaced, and the hemiformal (I) is a group of A liquid hemiformal mixture, characterized in that the molar ratio of hemiformal (II) is at least 1. 5. The mixture according to claim 4, wherein n is a positive number greater than 1 and less than about 5, and m is a positive number greater than 1 and less than about 5. . 6, n is a positive number between about 1.2 and about 2.5, and m is a positive number between about 1.2 and about 2.5. A mixture according to range 5. 7. Formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, n is greater than 1, x has a value of 0 to about 3, and R is a monovalent group) Liquid hemiformal composition having the following: at least two of the ortho or para positions relative to the O(CH_2O)_nH group are open in the composition, and x=0 for at least 50 mol% of the composition. A liquid hemiformal composition characterized by: 8. The composition of claim 7, wherein n is a positive number greater than 1 and less than about 5. 9. The composition of claim 7, wherein n is about 1.2 to about 2.5.