DE2058413C3 - New aromatic carboxylic acids, processes for their preparation and functional derivatives of these carboxylic acids - Google Patents

Description

B-C

C-

R ^:

CH,

R ¹

in which the isopropylidene groups are linked with ring B in the m- or p-position to one another and with the rings A or C in the m- or p-position to the CO-Y or π CO-X group, R ¹ and R ^{2 are the} same or are different and are hydrogen, (C, - d) -alkyl, halogen, phenyl. Carboxy, (Ci —C4) -alkoxycarbonyl and phenoxycarbonyl can be and X and Y can be either the same or different and - ^{: |} OH, methoxy, phenoxy. Halogen, amino, phenylamino. Mean hydrazino or benzoyloxy; in addition, X and / or Y can each be the two-volume radical ^{with R 'or R 2}

j!

- O- C

represent and thus form one or more anhydride rings. in

2. Process for the preparation of the carboxylic acids of formula (I), characterized in that aiky! aromatic hydrocarbons of the general Formula (II)

R ²

'; ■■■ - V ¹ Va

R '' CFI,

Λ Β

CII., R ²

(H)

in which the rings A, B and C are linked to one another analogously to formula (I) and the substituents R ¹ and R ^{2 have} the meaning and position as described in claim 1 with nitric acid, stainless gases, oxygen or oxygen-containing gases at temperatures between 100-25O ⁰ C, optionally under increased pressure and in the presence of heavy metal catalysts and initiators.

The present invention relates to novel aromatic carboxylic acids and carboxylic acid derivatives in general formula 1

R ²

ClI,

R-

C · '"' II,

R ¹

er 'iv h-jpropvlk1engn.i | ipen with ring B in m- or'.'iiiü!.:.! linked to one another in each of the rings A or C in the m- or p-position to the CO-Y or CO-X group, R ¹ and R- are identical or different and are hydrogen. (C, -O) -Alky !, halogen, phenyl, carboxy. (Ci-OJ-A'koxycarbonyl and phenoxycarbonyl and X and Y can be either the same or different and are OH, methoxy, phenoxy, halogen, amino, phenylamino, hydrazino or benzoyloxy; in addition, X and / or Y can each mean with R 'orR ^{2 the} double-bonded remainder

- O — C -

represent and thus form one or more anhydride rings.

Aromatic di- or polycarboxylic acids and their derivatives are valuable intermediate products for production of synthetic resins, e.g. B. alkyd and polyester resins and plasticizers. The characteristics of these products can be z. B. strongly influence by the choice of di- or polycarboxylic acid and can on this way in some ways, e.g. B. in the hardness, the physical drying of lacquer films, the volatility and migration resistance in plasticizers can be significantly improved.

However, only relatively few aromatic carboxylic acids are produced on an industrial scale because usually the starting products are difficult to access or in insufficient purity. Only Monosubstituted benzoic acids, such as toluic acid and chlorobenzoic acid. Hydroxybenzoic acid. the different Phthalic acids o-, ni-, p-phthalic acid and a few Polycarboxylic acids such as trimellitic and pyromellitic acids are relatively easily available. In this respect, the dicarboxylic or polycarboxylic acids according to the invention mean a essential enrichment for the manufacture and modification of synthetic resins.

The di- or polycarboxylic acids according to the invention are prepared by oxidation of alkyl aromatics of the general formula II

R ²

C ¹ H.,

CH,

in which the isopropylidene groups are linked to the rings analogously to formula I and the substituents are Ik leutung and position have as they are for formula I. are described. According to the earlier application P 20 55% 8.6, such alkylaromatics are for the first time also for technical purposes easily accessible.

The oxidation can be carried out with chromic acids, permanganate and similar known inorganic oxidants be performed. However, preference is given to nitric acid, usually in dilution, nitrous gases and Oxygen or gases containing oxygen are used as cheap oxidizing agents. You get the Carboxylic acids according to the invention in good and excellent yields.

That was by no means to be expected: Inehrlach attempts have been made (compare, for example, US patents 27 44 K ?. ¹ and 27 12 54!), Structurally similar aromatic carboxylic acids. / .. B. Isopropylidenedibanoic acid and isopropylidene-his-o-phialic acid by oxidation of

Isopropylidene-bis-toluene and isopropylidene-bis-o-xylene to win with nitric acid. The yields of these carboxylic acids are quite moderate Production of these carboxylic acids by this process is therefore completely uninteresting for technology.

The reason for the moderate yields undoubtedly lies in the structure of the starting products their possibility of side reactions.

On the one hand, Dipi.enylpropanes are easily cleavable with acid catalysis on the isopropylidene group. Friedel-Crafts catalysts are effective even at temperatures below O ^'J C. Thus, mineral acids such as HNOi, especially at higher temperatures, are likely to trigger cleavage.

On the other hand, one observes the oxidation of methylaromals with nitric acid, e.g. B. from p-xylene to Terephthalic acid, always small amounts of Nnroarcmaten. Nitro groups can, however, only be introduced on the starting product, since this is done in stages Course of the oxidation after formation of a carboxyl group, i.e. a substituent of the 2nd order, the Nitration is almost completely prevented under the prevailing reaction conditions. Such a one Suppression of undesired Niirierungsrcaktioncn applies to the oxidation, z. B. of bis-iolylpropanes, however not to. On the contrary, after oxidation one Methyl group to the carboxyl group, the aromatic nucleus of the nitration remains easily accessible, yes, this can even be done much more easily afterwards, since the The resulting carboxyl group increases the solubility of the compounds in nitric acid.

It is also known and for 1,4-diisopropylbenz <; l it has also been confirmed by our own experience that with the nitration of p-cymene (compare Ind. eng. Cheni. 28, 589-601 [1936]) or p-diisopropylbenzene (compare Am. Soc. 65, 2434-9 [1943]) with a strongly exothermic Reaction and partly! ' Resinization, splitting off of an isopropyl group and its replacement by a nitro group Extraordinarily easy success, what can be transferred to the present lall, can turn into splitting, z. B. the bis-tolyl-propane, as a side reaction bji the Means nitric acid oxidation.

In addition, if the reaction time is longer, the isopropylene residue can also be used with the oxidizing agents react.

It was therefore expected that the starting products of the formula II, structurally similar to the diphenylpropanes, z. B. in the case of oxidation with nitric acid, also perhaps to a greater extent in the side reactions described entered, especially since the middle aromatic nucleus (B) during the whole The reaction remains free of the carboxyl groups aggravating the nitration and the solubility of the Compounds after conversion of the methyl groups of the aromatic nuclei (A) and (C) into carboxyl groups is increased considerably.

Unfortunately, however, all side reactions take place to a much lesser extent than with the comparatively mentioned Diplicnylpropandcrivalen, so that the respective bulges at uniform :! Carboxylic acids can be described as surprisingly good.

Furthermore, it has not yet been described that bis-tolylpropane can be oxidized to aromatic carboxylic acids with aerosol. That is given the broad Use of this procedure is surprising and can only be interpreted in such a way that it is used for connections this yps so far has vers.n't.

All the more surprising. that the ingenuity Carboxylic acids are obtained in excellent yields by air oxidation, which is mainly because of this It is astonishing because even at temperatures of 180-00 ° C in an acidic medium neither cleavage nor i oxidative degradation at the isopropylidene group in takes place to a significant extent. The fear that such a breakdown could lead to the application of Luftoxydaticn Making it practically impossible was actually justified, since in certain cases we are among the by-products

ίο the air oxidation ix-methyl-styrene derivatives clearly could prove.

The invention therefore also relates to a process for the production of those according to the invention Carboxylic acids or carboxylic acid derivatives of the formula I,

ij which is characterized in that alkylaromatic hydrocarbons of the general formula II with nitric acid, nitrous gases, oxygen or oxygen-containing gases at 100-250 ⁰ C, preferably 120-200 "C, optionally under elevated pressure and

j »in the presence of heavy metal catalysts, oxidized. Suitable starting materials for the preparation of the carboxylic acids according to the invention are alkylaromatics of the general formula II, /. B.

> -> \. \ '- bis (4-methylphenyl) -p-diisopropylbenzene.

■ v, V-bis (4-methylphenyl) -m-diisopropylben / ol.
\ A'-bis (3,4-dimethylphenyl) -m- and

-p-diisopropylbenzene,
λλ'-bis (2,4-dimethylphenyI) -Hi- and
sn -p-diisopropylbenzene,

\ .. \ '- bis- (2.5-dimethyIphenyI) -ItI- and

-p-diisopmpylben / ol,
\. \ '- bis- (2.4, b-methylphenyl) -Hi- and

-p-diisopropylben / ol.
ι, \, \ '- bis (4-meih> Ii-phenyl-phcnyI) -Hi- and

-p-dii sop ropy! benzene.
\ / «'- bis (4-methyl-3-chlorophenyl) -m- and

p-diisopropylbenzene,
A .. \ '- bis (2-chloro-4-methylphenyl) -m- and

-p-diisopropylbenzene.
i \, (\ '- bis (4-carboxy-4-methylphenyl) -ni- and

-p-diisopropylbenzene and
i \,. \ '- bis (4-methoxycarbonyl-3-niethyl-

phenyl) -m- and -p-diisopropylben / ol.

The oxidation can be carried out in solution or in bulk. The solvents must be inert and should dissolve the starting products appropriately well. Suitable are / .. B. aliphatic ^ carboxylic acids such as Acetic acid and propionic acid. Nitroben / ol and chlorobenzene.

The application of pressure is not absolutely necessary, but it is necessary to achieve a faster rate Implementation at elevated temperature or to increase the oxygen partial pressure is usually appropriate.

The reaction temperature is not very critical. Man can achieve conversions at 100 C both with oxygen and with nitric acid. On the other hand make yourself Side reactions hardly noticeable even at temperatures around 200 "C.

In principle, both the Nitric Oxydaiion like air oxidation carried out without catalysts will. However, catalysts do not only increase the reaction rate, they improve it also the selectivity of the Re.iklion. be that in. in her appropriately usable. Suitable as catalysts are heavy metals like cobalt. Nickel. Iron. Manganese. Chrome. Vanadium. Bismuth. Lead. Mohbdan, tungsten

and their compounds such as oxides, nitrates. Sulfates. Chlorides, bromides. Acetates, naphthenates and ben / oates. They are obtained in quantities of around 0.001 - 10% applied to the hydrocarbon used.

The use of initiators such as aldehydes and aliphatic ketones is also possible for air oxidation. z. B. paraldehyde. Acetaldehyde, methyl ethyl ketone and diethyl ketone to eliminate the induction period. of bromine and of bromides such as ammonium, potassium. Cobalt and manganese bromide maintenance a relatively high ridical concentration is recommended. The form of application of the oxidizing agent is not very critical. Nitric acid can / .. B. 5- to 50ge \% maybe percent solution and oxygen in pure form and also be inserted as desired with inert gases such as nitrogen and carbon dioxide diluted in the reaction.

The oxidation can be carried out with one or more oxidizing agents, e.g. B. with ENT. NO ₂ and O ₂ . carried out simultaneously or one after the other. In the production of the tetracarboxylic acid from: vV-bis- (3.4-dimetriylprienyl) -diisopropyibenzene / .. ß. a pre-oxidate can first be obtained with air, which then gives the tetracarboxylic acid after treatment with HNOj.

The carboxylic acids according to the invention are isolated by filtration or centrifugation, which Purification of the raw products by boiling and recrystallization from suitable solvents Conversion into the alkali or ammonium salts and precipitation of the same or also by saponification for example, the easily accessible Methylcsier.

From the di- or polycarboxylic acids according to the invention, according to processes known per se, those of the corresponding to general formula I, carboxylic acid derivatives can be synthesized.

The compounds according to the invention are valuable starting materials for the production of synthetic resins with excellent transparency. Chemical resistance and / or temperature resistance and plasticizers.

example 1

A melt of 61 g? \ A'-bis (4-methylphenyl) -p-diisopropylbenzene, 0.1 g of manganese (II) acetate and 2 drops of bromine are oxygenated for 2 hours at 160-170 ° C fumigated. After cooling, it is taken up in 200-250 ml of glacial acetic acid, heated to the boil and suctioned off while still hot. The filter cake is washed with hot glacial acetic acid and dried: 8 g, melting point 317.degree. C.-320.degree.

Acid number: 265-270
ber. 279

NMR: Analysis: A, a'-bis- (4-carboxyphenyl) -p-diisopropylbenzene. After evaporation, extraction with toluene and distillation of the Toluene phase obtained 36 g of unreacted starting product. The residue, which is sparingly soluble in toluene (16 g Mp. 206-263 ° C.) consists largely of ac- (4-methylphenyl) - <x '- (4-carboxyphenyl) -p-diisopropylbenzene.

20.125 g (0.05 mol) \, (\ '- bis (4-carboxyphenyl) -p-diisopropylbenzene, 30 g (0.5 mol) ethylene glycol, 5 mg antimony trioxide, 20 mg calcium acetate and 5 mg titanium bulylate are added at 220 -23O ⁰ C bath temperature under Wasserabspa Settin g condensed. at 240-260 ⁰ C then excess ethylene glycol is abdestillicri and terminates the condensation at 250 -260 "C and 0.1 mm Hg. 5 g of polyethylene are added to the polycondensate and at 280 C in 1 '/ : h cingecstcrt.

A yellowish polycondensate is increased with a Melting temperature of 111 "C, which is easy to foil and has fibers processed.

Example 2

A mixture of 250 g of a, a'-bis (4-methylphenyl) -pdiisoprojj, »benzene, 130g glacial acetic acid, 0.5g manganese (ll) acetai and 10 drops of bromine through a frit at the bottom of a cylindrical reaction vessel with Saueri " substance (5-7 l / h) fumigated at 100-1 IOC. After about 150-170 hours, 40 g of dicarboxylic acid are obtained. the The composition of the remaining oxidate is similar to that in Example 1.

! - B eis ρ ie I 3

A mixture of 600 g <x.V-bis- (4-methyIphenvl) -pdiisopropylbenzene. 1 kg of glacial acetic acid. 5 g of manganese acetate. 5 g ammonium bromide and 10 g paraldehyde is in one Pressure pipe gassed with 400 liters of air at 8 atmospheres and 140-160 ° C. After 5-6 hours the oxidation ceases canceled, the mixture cooled to 100-110 pressed and the filter cake boiled with glacial acetic acid. 293 g of A'-bis (4-carboxyphenyl) pdiisopropylbenzene are obtained (M.p. 318-322 ° C). Mother liquor

2 ~> and washing solution are combined and freed from glacial acetic acid. 339 g residue. After warming up with toluene, 231 g of melting point 200-207 'remain. which consist essentially of monocarboxylic acid. The toluene phase is fractionally distilled and increased

«Ι 65 g of unreacted starting product and 40 g resinous residue. Conversion of hydrocarbon: 89% yield of dicarboxylic acid: 81% of theory. Th. Under Taking into account the fact that the monocarboxylic acid is further oxidized to the dicarboxylic acid.

Example 4

Example 3 is repeated with propionic acid as the solvent at 160-180 ° C. After 3 hours of oxidation 372 g of dicarboxylic acid are obtained (melting point 319-322'-C). 4 (i The mother liquor is worked up as in Example 3. Es 225 g of monocarboxylic acid, 30 g of starting product and 29 g of resin remain. The conversion of hydrocarbon is 95%. The yield of dicarboxylic acid is 89% of theory.

Example 5

A mixture of 150 g of ₁ A'-bis (4-methylphenyl) -mdiisopropylbenzene. 1600 g glacial acetic acid, 3 g cobalt acetate. 1 g of potassium bromide and 10 g of paraldehyde are added for 5 hours at 160-166 ° C at 9 atmospheres and 300 liters / hour. Air oxidizes. On cooling, a. <X'-bis- (4-carboxyphenyl) -m-diisopropylbenzene crystallizes out of the solution, which is filtered off with suction, washed well with glacial acetic acid and dried. 69 g m.p.

Number of sows: 268-272
ber. 279

IR and NMR analysis: <\, i \ '- bis (4-carboxyphenyl) mdiisopropy !benzene.

WJ 30 g (approx. 0.075 mol) «.« '- Bis - ^ - carboxy-phenyO-mdiisopropylbenzene, 30 g (approx. 0.5 mol) of ethylene glycol and 10 mg of titanium tetrabutoxide are kept at a bath temperature of 220 ° C. under N2 until most of the water has been distilled off. Then one heats he ¹ d.05 Torr within

ti "i ..in 2 '/ _' h to 270 ^° C. and holds 1 - h at this temperature. The yellowish, transparent polycondensate has a relative viscosity of 1.596, corresponding to a molecular weight of 81,000.

The line temperature is 87 C, the Zerselziingsieuiperatur > 380 "C. Line l'olie des i'rodukics The present example is after 200 h at 65 ° C in IO "/ iiige caustic soda and after 3 months and 10% N lh solutions unchanged at low temperature.

In comparison, the unier was far cheaper l-ietliiisiiügcn a (jriiiuilaiprobe of Polyäthyleiue-. eplithakii 60 hours at 60 ° C with 10% sodium hydroxide solution beh .-; r.d -. 'left The weight loss of the granules was according to this Behaiiulu.ig 14%.

A solution of the polycondensation in benzene is poured into a bottle and baked at 150 ° C. for 30 minutes. A colorless, scratch-resistant, glossy, elastic and well-echoing coating is produced.

IS

H e i s ρ ι c I 6

A mixture of 150 g of bis (4-methylphenyl) pdiisopropylbenzene. 1.5 1 glacial acetic acid, 5 g manganese acetal. 2 g of KHi and 10 g of paraldehyde are subjected to oxidation at lb5-180 "C, 9 atm and 100-300 ltr./hour air einzupumpen. the dicarboxylic acid formed is separated off, washed with hot glacial acetic acid and dried. the residue of the washing solution is added to the 2 ^r> mother liquor aufkonzcntrierl this with Ausgangsprodukl and pumped back into the reactor. about 10 cycles a total of 1655 g are \ .V- Bis- (4-methylphenyl-p-diisopropylbenzene is used and 17Ob ₁ L ¹ dicarboxylic acid (Section 31b -J19'C ") is obtained. This corresponds to a yield of 87% of theory.

Line sample of the Dicarbonsiiurc. in the autoclave by Lrhit / cn purified with glacial acetic acid to 200 C, has a mp. of 323 -J2 ^r) C and a Säurczahl of "27 3-273 (calc. 274).

Example 7

a) Line mixture of 115 gr \., V-bis (3,4-dimethylphenyl) -p-diisopropylbenzene, 1100 g of 15% aqueous nitric acid. 2 g of vanadium pentoxide and 2 g of copper (II) -aeetai are kept in a 2-liter autoclave under an initial air pressure of 25 atmospheres at 150 ° C. for 5 hours. After cooling, the crystals are filtered off with suction, washed with plenty of water and dried: 139 g, i.e. 91% of theory. By boiling the crude product with toluene, 133 g of V-bis- (3,4-dicarboxyphenyl) -pdiisipropylbenzene, ie 87% of theory, are obtained. Th. The nitrogen content of the product is 0.1%, the acid number 446-451 (calc. 457). Mp. With elimination of water 192-198 ^D C. The structure is confirmed by IR and NMR analysis.

b) 24 g .A., i \ '- bis (3,4-dicarboxyphenyl) -p-diisopropylbenz.ol are refluxed in 100 g of acetic anhydride for 1 hour. Crystallize on cooling 15 g of a product with a melting point of 220-22I = C. a nitrogen content of 0.03% and a saponification number of 487 (calc. 493). The NMR analysis confirms the conversion of the bo Tetracarboxylic acid in its bisanhydride.

c) 22.723 g (0.05 mol) t \, V-bis (3.4-dicarboxyphenyl) -p-diisopropylbenzene dianhydride, 5.21 g (0.05 mole) neopentyl glycol and 120 ml anhydrous chlorobenzene are refluxed until a b5 clear solution has emerged. The polyester polycarboxylic acid is precipitated by pouring it into ligroin. A white product is obtained in the form of the triethanolamine salt Clearly soluble in water. The IVily condensate is suitable as a hardener for epoxy resins and ν branching or crosslinking agents for polyester.

Example 8

As described in Example 7, r \ .V-bis- (3.4-diincihvlphenyl) oxidized in-diisopropylbenzene. Raw product: 140 g, d. s. 92% d. Th. After boiling with toluene, 127 κ, d.s. 83% d. Th .. nitrogen content: 0.13%, κι Säue / ahl 447-449 ibcr. 457), m.p. 186-189 C under Cerv. : /. approx.

! R and NMR analysis confirm the structure of a λ. V- B is- (3.4 -diearbonboxvpheny I) - m -diisopropylbenzene s

Example 9

34.2 g (0.1 mole) <x, V-bis (4-carboxyphenyl) -p-diisopropylbenzene are suspended in 100 ml of benzene, mixed with 10 drops of dimethylformamide and on 50 "C. To this, 25 g of thionyl chloride are added dropwise in about 30 minutes and hold on for a long time 50-60 "C. Until no more gas evolution is observed. After distilling off benzene and excess Thionyl chloride leaves 30 g of crystalline residue (melting point 107-110 ° C.). By recrystallization Benzene, cyclohexane give 21 g of yellowish crystals with a melting point of 114-116 ° C.

The chlorine content is 16.4%.

Eür ^, V-bis (4-chlorocarbonylphenyl) -p-diisopropylbenzene the chlorine content is calculated to be 16.16%.

21.96 g (0.05 mol) \, V-bis (4-chlorocarbonylphenyl) p-diisopropylbenzene and 17.3 g (0.05 mol) i \, \ '-Bis- (4-hydroxyphynyl) -p-diisopropylbenzene are each in anhydrous methylene chloride dissolved, the solutions combined and 20 ml of anhydrous pyridine added dropwise. Then another 0.2 g of acid dichloride are dissolved _{in CH 2 CIj.} added and left to react for 15 minutes. The polymer is precipitated by pouring the clear solution into methanol. The resinous precipitate quickly turns into a crystalline state and only dissolves again in hot, high-boiling solvents such as chlorobenzene. Dichlorobenzene and cyclohexane.

The glass transition temperature is! 50 "C. The crystal · melting point the decomposition temperature door is at 175 ° C, about 400 ⁰ C.

Example 10

200 g of A, V-bis (4-carboxyphenyl) -p-diisopropylbenzene are dissolved in 1000 g of methanol in an autoclave at 200 ° C. for 5 hours held. On cooling, 152 g of crystals precipitate from the reaction solution and precipitate after recrystallization Melt methanol at 112-113 ° C, according to thin-layer chromatography Investigation are uniform and, according to NMR analysis, <x, "'- bis (4-carbomethoxyphenyl) -p-diisopropylbenzene represent.

47 g (approx. 0.11 mol) of ct, a'-bis (4-carbomethoxyphenyl) -p-diisopropylbenzene, 23 g (approx. 0.22 mol) of neopentyl glycol and 10 g mg of Sb ₂ Oj are melted _{under N 2} . From a bath temperature of 260 "C the elimination of methanol begins, which takes place rapidly at 275 ° C. After 3 h under normal pressure, 1/2 h water jet vacuum (12 Torr) and 4-5 h high vacuum (0.2 t) are applied at 270-300 ° C bath temperature.

A light gray melt is obtained. After cooling, it is dissolved in CH ₂ Cl ₂ , filtered and _{precipitated with CH 1} OH, filtered off with suction and dried. The polymer has a rel. Viscosity of 1.452. The solution can be cast into foils.

The Linfner temperature is 132 C. Decomposition is above 420 "C. When exposed to poorly dissolving solvents, * Isopropanol will crystallize the film through turbidity, as from the X-ray diffraction diagram can be seen.

Knstall melting point 175 ° C.

After about 2 months of storage in 10% ammonia solution Isi a foil unchanged, the same after 600 hours in boiling 10% sodium hydroxide solution. 10% Boiling hydrochloric acid only attacks the film noticeably after 150 hours. (See opposite comparison attempt in example>).

Example 11

[• 'in a mixture of 40.2 g of t, ^' - bis (4-carboxyphenyl) -pdiisopropylbenzene, 40.2 g of phenol, 64.2 g of diplicnyl carbonate and a trace of Tiliinleirabutylal will last for I Ii 200 - 240 C until no more gas escapes. After distilling off the remaining PhCiH) Is in vacuo up to 250 '(.' and cooling, 67 g of a yellow

■> Krislallkiichens. M.p. 199-201 "C" (from toluene).

The NMR analysis confirms the structure of a

AA'-bis (4-carbophenoxyphenyl) -p-diisopropylben / ols.

27.37 g (0.05 mol) \, \ '- bis (4-chloropheno \ y-phenyl) -

p-diisopropylben / ol, 17.32 g (0.05 mol) \. \ 'bis- (4-hy-

Hi droxyphenyl) -p-diisopropylben / ol and I mg Nalrkiminclhylai are under N_. auigeschniol / cn. Hei 2W) C Bath temperature starts to distill phenol / ti. Within I h is heated to 300 "C, the I laiipl amount Phenol dissolves. Man liil.it for another 2 hours

r> i () 0'C and 1 Torr and receives a yellow, clear and hard polycondensal. The relative viscosity is 1.24j. The freezing temperature 15b C.

Claims (1)

Patent claims: 1. Carboxylic acids and carboxylic acid derivatives of the form! (I) R ² γ-c-Ia ' CH, R ²