DE1520636A1 - Process for the production of internally plasticized phenolic resins - Google Patents

Description

File number! P 15 2o 636.7 1520638

REIGHHOLD CHEMIE AKTIENGESELLSCHAPT, Hamburg 7o, Iversstr. 57

Process for the production of internally plasticized phenolic resins

A major deficiency of the curable phenol-formaldehyde resins is their brittleness in the hardened state effectively elasticizing these resins is almost like that old, like their technical use »The polar nature of curable phenolic resins limits the choice of suitable plasticizers very strong a · There must be more or less polar compounds with the phenolic resin both in the soluble or fusible initial stage, as well as compatible with the cured, crosslinked phenolic resin,

It is known to use hardenable phenolic resins with ester plasticizers, such as phthalic acid, adipic acid or phosphoric acid esters plasticize · This type of plasticization as well as the durability However, the hardened masses against chemicals is unsatisfactory. They are also used as plasticizers partial or complete esters of polyols for phenolic resins with low molecular weight fatty acids as well as the polyols themselves have been proposed. However, tolerability is these substances are limited with phenolic resins. Due to the hydrophilic nature of these compounds, the cured art substances sensitive to water. The aforementioned soft

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making substances are neither involved in the hardening reaction of reoils, still in the hardening of novolaks, e.g. with hexamethylenetetramine, involved. In this way, only external plasticization is possible and only to a limited extent.

Since the external plasticization of phenolic resins is unsatisfactory, there has been no lack of attempts to internally use these resins to plasticize, i.e. to bind the plasticizer to the phenolic resin through chemical reaction. It was suggested e.g. # Resoles etherified with butanol with conjugated double bonds the wood oil fatty acid or with oxyoleic acid residues of castor oil to react. It is mostly assumed today that with the participation of an ortho-standing Methylol group and the phenolic hydroxyl group with the Double bonds of fatty acids, so-called chroman ring systems form.

Furthermore, partial esters of polyols with monocarboxylic acids and / or dicarboxylic acids, ie the free alcoholic Containing hydroxyl groups, with the methylol groups of resoles be made to react under etherification. These Internally plasticized phenolic resins have a reduced reactivity and are used because of the high curing temperature required exclusively as a basis for stoving enamels. As a binder e.g. for laminates and molding compounds they are not useful.

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However, unetherified resols modified with wood oil and / or natural resins are used for this purpose. However, the formation of the chroman ring system and thus internal plasticization only occurs at temperatures above 160 ° C. However, since such high temperatures are not used in the processing of phenolic resins with curing times that are customary in the industry, it can be assumed that only external plasticization is achieved with this type of modification. Then leaves?, Ush Cte lack of resistance include cured films to solvents.

The rigidity of simple, cured phenol-formaldehyde resins is undoubtedly based on the fact that the individual phenol radicals are predominantly connected to one another by methylene bridges. It has therefore been proposed to react di- or .Polyphenols with formaldehyde, in which the Abetände between the phenol nuclei are increased by longer aliphatic bridges, di- and polyphenols of this type are described in French patent 808 717 and are made by reacting chlorinated paraffins with phenols, obtained in the presence of Friedel-Craft ¹ S catalysts. Similar processes for the preparation of such polyphenols and their use in the formation of phenol-formaldehyde resins are described in the literature listed below:

German patent application ρ l8o 39 D, German patent application K 229 09 IVb / 39c (DAS 1 o26 o71),

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American patents 2,859,203 and

2,859 2o4; W.H. Brockes, Ind.Engng.Chem. 53, 7 (1961) pp. 57o-572

The use of polyphenols leads to well-plasticized synthetic resins. However, their reactivity is very low and insufficient for most purposes. Another disadvantage is the low content of aliphatically bound Chlorine. This reduces the electrical and corrosive properties, as a result of the unavoidable elimination of the halogen, worsened.

In French patent 9 ^ 4 132 and the identical American Patent 2,623,891 is the manufacture of polyphenols described by the reaction of phenol with unsaturated fatty acids in the presence of Friedel-Craft'e catalysts are obtained. The condensation with formaldehyde leads to well plasticized resins. A disadvantage of this method is the cumbersome display the di- or polyphenols, as well as the low reactivity of these bodies.

It has now been found that simple phenol-formaldehyde resins based on phenol, cresols, xylenols or similar phenols by reaction with epoxidized, unsaturated ones oils or derivatives of epoxidized unsaturated fatty acids or epoxidized unsaturated fatty alcohols plasticize permit. Both novolaks and resols can be used in

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same way for the implementation with epoxidized unsaturated, oils or derivatives of epoxidized unsaturated fatty acids are used. They act in the phenolic resin of the acidic or basic condensation still present contact agents such as oxalic acid, sulfuric acid, phosphoric acid or Ammonia, amines, alkali and alkaline earth metal hydroxides as catalysts for the reaction of phenolic resin with those mentioned epoxidized compounds. The addition of the compounds containing epoxy groups to the reactive sites of the phenolic resins - mainly to the phenolic hydroxyls or, in the case of resols, also to the methylol groups - is shown by the analytically traceable decrease in the epoxide group content of the reaction mixtures.

The invention thus relates to a method for producing internally plasticizing, heat-curable phenol-formaldehyde condensation products, characterized in that phenol-formaldehyde condensation products with epoxidized, Unsaturated fatty acid derivatives containing unsaturated glycerides and / or epoxy groups with heating reacted and optionally post-condensed with formaldehyde.

In the context of the invention, epoxy compounds suitable for combination with phenolic resins and initially natural glycerides containing epoxidized unsaturated fatty acid residues, for example soybean oil, safflower oil, linseed oil and the like. Also to be mentioned are epoxidized esters of synthetic unsaturated fatty

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acids as well as tall oil fatty acids with glycerine and synthetic ones Dialcohols, trial alcohols and higher alcohols of the most varied types. Epoxidized partial esters of unsaturated fatty acids are also suitable for reaction with phenolic resins suitable with polyols, which are easily obtained from unsaturated natural glycerides by transesterification with polyols, e.g. with glycerine in the form of mono- or diglycerides are easily accessible. As derivatives of epoxidized unsaturated Fatty acids are also esters of monohydric alcohols, amides, nitriles, hydrazides, hydrazidines or amidrazones Question that on average have one or more epoxy groups in the molecule. Next are epoxidized fatty acid esters which are based on esters of unsaturated fatty acids with saturated monoalcohols or saturated fatty acids with unsaturated alcohols or unsaturated fatty acids with unsaturated ones Alcohols are.

Examples are butyl epoxystearate from butyl oleate, glycidyl stearate from allyl stearate and epoxidized allyl oleate the epoxy groups can be contained in the fatty acid residue as well as in the alcohol residue, epoxidized unsaturated oils, Derivatives of epoxidized unsaturated fatty alcohols are according to known processes easy to manufacture. ' Depending on the degree of unsaturation of the output materials For the purposes of the invention, partially or completely epoxidized compounds can be used. The one between the epoxy groups of the substances mentioned and the phenol-formaldehyde condensate products The reactions that take place are inconsistent with the nature of the

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Resin bound and run under conditions as they are in the manufacture or processing of technical phenolic resins are common. The end products obtained after complete curing are characterized by excellent plasticization the end. In addition to good mechanical properties and excellent electrical fourths, they also show good resistance against solvents and chemicals.

Phenol-formaldehyde resins plasticized according to the invention are particularly suitable for the production of laminates such as hard fabrics, Cold punchable hard papers, molding compounds with increased Impact strength, insulating silk, insulating paper and elastic coatings of all kinds are suitable.

Example 1;

25o g of a resole, the g in a known manner by condensation of 470 phenol, 4oo g 3o tigern formaldehyde and 5o g of aniline 80 ⁰ C and then dewatering was prepared under vacuum at will with 2oo g epoxidized soybean oil (oxirane oxygen content: 6%) 1 Brought to reaction at 130 ° C. for 1/2 hour. The epoxy group content fell to two thirds of the original value during this reaction. The reactivity of the resin to a Härtuzeit of about 5 minutes was performed by adding further 15o g 3o / Sigem formaldehyde, Io g ammonia, condensation at 80 ⁰ C, followed by dewatering under vacuum. ^C set at l6o C. The resin νατ clearly soluble in fuel.
There were generally got after dom. C "v ^ fnlirun, (lurch Imprär * -

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ning of 80 g / m heavy α-cellulose paper, followed by Drying and pre-pressing of 12 layers of this resin-laden Made of paper, hard paper. They have been tested for their punchability at room temperature in accordance with DIN pre-standard 53 488 tested «Hard papers made using the resin according to this example« own one On the other hand, hard papers made comparatively from unplasticized phenolic resins had a punching value of under 2. a punching parameter of over 4.

Example 2;

A novolak was prepared from 47o g of phenol, 284 g of 36 tiger formaldehyde and 4.7 g of oxalic acid with reflux and dehydrated under vacuum. 4oo g of this novolak was mixed with 2oo g epoxidized soybean oil and brought 2 hours at 150 ⁰ C for reaction. The oxirane oxygen content fell to two-thirds of its original value during this reaction. The resin obtained could be cured in 3 minutes at 160 ° C. with the addition of 3% hexamethylenetetramine.

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Claims (5)

File ON "bte <U0JO PATENT CLAIMS / 1 J Process for the production of internally plasticizing, heat-curing phenol-formaldehyde condensation products, characterized in that phenol-formaldehyde condensation products are reacted with epoxidized, unsaturated olcerides and / or epoxy-containing derivatives of unsaturated fatty acids with heating and optionally with formaldehyde post-condensed. 2. The method according to claim 1, characterized in that the phenolic resins are condensation products of mono- or polyvalent or / and alkylated phenols with formaldehyde can be used. 3. The method according to claim 1 or 2, characterized in that the plasticizing epoxy-containing fatty acid derivatives partially or fully epoxidized fatty acid mono- or polyalcohol ester yamides, hydrazides, nitriles, -hydraaidine, -amidrazone and epoxidized fatty acid esters are used with lower or higher unsaturated alcohols, the epoiydgruppen in the fatty acid and / or Alcohol content is included » 4. New phenol-lownaldthyd-ion * · * - food products available from the JUtIt according to the process mentioned in claim 1 bit 3 . 909816/0640 Ncua documents (An.751 paragraph 2 no. 1 Sofc 3 BADORJGfNAL I / O 5. Use of the plasticized phenol-formaldehyde resins obtainable in accordance with the processes mentioned in claims 1 to k for the production of laminates, such as hard fabrics, cold-danceable hard papers, molding compounds with increased impact resistance, insulating silk, insulating paper and elastic coatings of all kinds. 8098t6 / 0640 BAD ORJGiNAL