DE1445240A1 - Process for the production of curable synthetic resins - Google Patents

Description

Process 2: ur production of curable synthetic resins The production of curable synthetic resins which are cured by interpolymerization known. So can unsaturated polyester resins by condensation of bivalent Alcohols and dicarboxylic acids, among which there are unsaturated components, getting produced. The curing takes place through copolymerization between the unsaturated linear polyester and a so-called conomer, such as styrene or an acrylic ester, which is temporarily used as an aluminum solvent for the polyester and with this. together under the influence of a catalyst into a solid end product transforms.

In contrast, the method according to the invention consists in that first on the one hand polyfunctional so-called "basic structures" and on the other hand, monofunctional So-called "end groups" prepared separately in terms of time and space and then optionally can be esterified into different end products. This procedure enables numerous Variations of the synthesis.

The so-called basic structures are obtained by using several dicar @ onic acids, those that are saturated, unsaturated or aromatic and, in some cases, also duroh 3 or higher valued Carboxylic acids can be replaced with several polyhydric alcohols, amine @ lkohelen or amines in excess initially z intermediates with a molecular weight of partly

500-15,000 are implemented. These basic structures are more or less complex branched and carry numerous hydroxyl groups both terminally and pendant. As a result of daE Excess hydroxyl groups, the fondensation takes place quickly and under mild conditions, so that an etherification is largely avoided. Because the basic structure is practical is neutral and can be stored almost indefinitely, it can be made in advance.

Instead of saturated, unsaturated or aromatic carboxylic acids Their derivatives, such as anhydrides or esters, can also be used. For the subsequent Esterification is the available number of hydroxyl groups, the number of which in a delayed Condensation product is particularly large, particularly important in the basic structure. at this esterification is advantageously used not the equivalent, but a lower one Mange of the acidic terminal links.

The so-called end groups, the non-functional ones, are prepared independently of this represent acidic compounds. For this purpose, dicarboxylic acid anhydrides are now used in excess at moderate temperatures with monohydric alcohols, amino alcohols or amines to a basic acidic half-star or half-amide. As end groups in the sense of In the invention, compounds are also suitable which in themselves only react sluggishly.

Even substances like higher fatty alcohols, secondary alcohols and these Corresponding mine is made into anhydrides by fusing with dicarboxylic acid converted into monobasic acidic compounds that can be used as end groups. Boi the use of secondary alcohols such as cyclohexanol is advantageous at relatively low temperatures, as the resulting half-ester decays back already tends above 1400.

Since the end links are stable at room temperature, too they are made in advance.

The backbones and end groups are then in roughly equivalent proportions by processes known per se, e.g. by heating, elimination of water, if necessary in Presence of catalysts and entrainers, together up to the desired Molecular size condensed with a possible low acid number. The last part of the reaction is particularly promoted by heating in a vacuum, also volatile and undesired impurities are removed at the same time.

A proportion of monocarboxylic acids can also be used as end groups, with also cyclic, saturated or unsaturated compounds such as naphthenic acids be considered. If special high molecular weight end products are desired, can you also have 2 or more backbone molecules, which are not necessarily the same composition and need to have the same structure through a bridge of dibasic acids Connect between groups.

The bifunctional acidic compounds can, for example, be dioarboxylic acids or their derivatives or also bifunctional acidic condensation products, such as oie from 2 moles of dioarboxylic anhydride and 1 mole of bifunctional alcohol, amine or Amino alcohol can be obtained.

The inventive method has a number of advantages.

Technically important is first of all the zeitgeist that appears next to each other, but spatially separated production of basic structures and end groups and the rapid The course of these basic reactions results. Another significant advantage is the large one Number of possible combinations: from half a dozen different "basic structures" and the same number of different groups "can for example be at least Manufacture 36 different end products. Their number becomes considerably higher by there are either several types of end groups and these again in changing proportions combined with each other. A third advantage is the expansion of the raw material base and thus also the property scale through the use of the monofunctional ones mentioned Compounds, among which optionally substituted monohydric alcohols, amino alcohols or amines and monocarboxylic acids predominate.

According to the method according to the invention, the position of the double bonds, which are the carriers of cerium polymerization, largely predetermined, the double bonds, which essentially in%, ß unsaturated mono- or mobr @ Erligen carboxylic acids are present, can either in that B @ undgerüst or to the end groups or to both places are relocated. This allows the material properties de esters largely influence. With growing Regularity the distribution of the double bonds are increasingly stronger and harder products obtained while increasing the standing of the double bonds softening each other works.

In the route according to the invention galingt ea, condensation products to produce which differ greatly in their molecular weight, so that they are either at the limit of solubility or because of their insolubility ai behave practically like monomers. Through a combination of he ## according to the invention manufactured components of different molecular weight can be used to determine the fluidity, the impregnation and usability and the sum of the physical-technical Have a decisive influence on properties. According to the scope of the method according to the invention the "end groups" are freely selectable according to number, type and combination. Of these will be the solubility, the compatibility with other compounds, the surface design, the behavior at increased temperature, the water sensitivity and many others Size is decisive.

By exchanging the end groups, the same basic structure can be created Manufacture synthetic resins with completely different properties.

One or more dioarboxylic acids can be used to produce the Grundestor react with a significant excess of hydroxyl groups, for example 4 equivalents of diearbic acid mixture with at least 6.5 to 7.5 equivalents of polyvalent Alcohols that are at least partially trivalent and higher. The implementation designed For example, as follows: I a) o-phthalic acid (9, -kg), azelaic acid (3.5 kg) Glycol (1.6 kg), diglycol (5 kg) and trimethylol prepane (6 kg) are combined in one Stainless steel cooker carefully melted under carbonic acid, with 120 g of a mixed catalyst (from faratoluenesulfonic acid and boric acid) added and under constant roaming and after addition of 20 g of diisopropyl-methylphenol initially brought to 150 °. Under Langzaner @increase of the temperature to 1700 wind the main amount of the reaction water aborted. If the acid number has dropped sufficiently and if the amount of water is released, what If the acid number is about 35-45, then toluene is about 150-160 ° a solvent cycle. There is again water and the acid number drops to less than 20. this product, which now contains around 10-20% toluene and its OH equivalent is about 300, can be used as a backbone with end group material implemented. It is not just that when measuring the corresponding initial weight OH equivalent weight, but also the own acid number of the one just made Basic ester to be considered.

This basic structure is free of double bonds and has clearly softening properties Character: Unsaturated end groups are therefore required for esterification0 The The attached end groups are then the sole carriers of the future interpolymerization (Hardening).

X b) In example a) the azelaic acid is replaced by adipic acid (2.95 kg) and the trimethyloprpane used there by pentaerythritol (5, - kg) in equivalent close replaced. The manufacturing technique remains unchanged.

A somewhat more branched basic structure is obtained than that of the esterification delivers significantly tougher products.

I c) In example a) all of the azelaic acid is replaced by maleic anhydride replaced in an equivalent amount. The manufacturing technique is not changed. Ee There is, in turn, a light yellow, resinous intermediate product of about the same OH equivalent weight, but because of the double bonds it contains Ale delivers a considerably harder end product (hardened mixed condensation product) the products manufactured in accordance with a) and b).

Instead of the method of working described, in the case of an internal etherification If a small loss of hydroxyl groups cannot be completely avoided, a Vacuum esterification can be used, which results in particularly light-colored products with lower OH equivalent weight can be obtained.

I d) (Construction of an unsaturated basic structure with the use of Mity ton amino alcohols) phthalic anhydride (6, - kg), maleic anhydride (3, kg) and Succinic anhydride (1, - kg) are poured over with toluene (5, - kg) and in a Condensation apparatus heated with stirring and with exclusion of air by CO2 as long as until dissolution has taken place. One slowly drips into this solution at about 80 ° Solution of 1.5 kg of N-methylmono-ethanolamine. and 2, - kg of triethanolanine in 3.5 kg Acetone. React with vigorous stirring and a simultaneous rise in temperature the boiled-up amino alcohols with the acid anhydrides presented. You keep that Temperature below 1000 and ensures that the introduced acetone continuously distilled off. After adding the amino alcohol mixture, the mixture is heated for a short time further and then with the help of vacuum the remaining acetone and finally also, as far as possible, the toluene at a maximum of 80 °. Then you give a preheated, a clear mixture of 2.6 kg of ethylene glycol and 5.4 kg of trimethylolpropane added to it until it is clearly mixed, carries 120g of a 3: 1 mixture of benzenesulfonic acid and boric acid and increases the temperature to 115-120 °. Initiate a With a weak stream of CO2, a vacuum of 100-120 Torr is applied. Distill immediately Residues of toluene as well as increasing amounts of condensation water from. One condenses until the acid number has dropped below 20 and then ateigort under setting the vacuum to about 20-25 Torr, the temperature briefly to 140-145 °. Go there volatile constituents are reduced again, the acid count continues to decrease slightly. Man Now lets it cool down under carbonic acid and gets a sticky, flowable, yellowish color Resin with an acid number of max. 15 and an OH equivalent of max. 250.

The creation of end groups is illustrated by the following examples: II a) Maleic acid cyclohexyl half ester: 392 8 maleoic anhydride 400 g of cyclohexanol are heated with vigorous stirring in a stream of carbonic acid for three hours to 100-110 °, A clear, yellowish melt with an acid number of 280- @ 1 (bo @ .for C10H14-O4 P 283-84), which solidifies in crystalline form soon after cooling. Yield almost quantitatively.

@@@@@@ / @@@@ @@@@@@@@@@ COPY II b) malic acid n-hexyl half ester: 992 g maleic anhydride 410 g n-Hex8nol The components are, as described under a), heated. A light yellow Schnelse is created in almost quantitative yield, the even after cooling, the agate remains liquid and only slowly a little Amount of crystals settles. Acid number = 268 (calc. For C10H16O4 = 285-86), II o) oleyl maleic acid half-ester: 196 g maleic anhydride 540 g technical oleyl alcohol are at about 120 ° below CO2 heated with vigorous stirring until the calculated acid number (C22H38O4) SZ = 155) sets.

A clear, yellowish melt is created, which later becomes a waxy crystalline mass solidified. Almost quantitative yield.

The following example illustrates how to make a polybasic Halbesters, which serve as a bridge to esterification with two or more basic structures can: II d) biocaleinic acid triglycol di-half ester 150 g triglycol 196 g maleic anhydride are together, as described in Example a - o, heated at 110-120 ° and implemented. After a maximum of 3-3.5 hours, the expected acid number is 325 achieved. The melt, which is clear in the heat, can become a little @beet in the cold. Water separation does not occur either here or in the preceding examples 2 a-- c in noteworthy proportions. Almost quantitative yield.

II e) (production of a partly saturated, partly unsaturated.

End group, the monohydric alcohol being replaced by an amine).

In a standard cooker, succinic anhydride (1, - kg) and Maleimic anhydride (0.98 kg) heated with 1, - kg of benzene until dissolved has occurred. In the on oa. 70 ° cooled solution gives man lengaam a solution of 2.26 kg of hexahydro-N-menomethylaniline in 2.5 kg of acetone with stirring. With warming and slight fog formation, an immediate reaction occurs, which you get through Continuous distilling off of the acetone and cooling to the extent that a temperature is moderate of 80-90 ° is not exceeded if possible. It separates a solid, whitish crystalline product, which is obtained after the addition has been completed and after concentration has been completed the reaction mixture in vacuo by subsequent cooling and suction in a solid Shape.

A dried sample of the product dissolves easily in cold, diluted, aqueous alkalis and shows the calculated equivalent of about 210-215 @ for the The air-dry or even the still moist crude product can be converted further or its suspension in the solvent can be used.

The following examples explain the overall invention: 1) 609. g des Base esters prepared according to Example I @ are placed in a standard laboratory cooker iür condensation resins under carbonic acid with 300 g of that obtained according to Example IIa Maleic acid cyclohexanol half esters added; furthermore 0.5% mixed catalyst (as in Example 1 a) and 1 g of di-isopropyl-methylphenol were added. The esterification is carried out at low temperature, using as much benzene as the water entrainer it is added that already at 105-110 ° there is a brisk solvent cycle adjusts. In the course of several hours, the original acid number drops from 100-110 first rapidly, then more slowly and with initially brisk separation of water about 20-22 from, occasional addition of benzene to regulate the cooking temperature is necessary.

Now is first at the same temperature and applied, slowly all solvents present are distilled off under increased vacuum and then, at a temperature slowly increased to 140-1500, with removal of more volatile Components complete the condensation even at full vacuum of about 20-30 Torr. The tough, clear, light yellow resin dissolves easily in half the amount at around 70-80 ° its weight on. Styrcl to a clear, moderately viscous solution, the one Has a viscosity of around 1000 - 1500 cP and an AN of 15. This solution can be used in the same way, e.g. by adding 2% dibenzoyl peroxide paste (50%) Harden 100-110 ° to a hard Kunethare.

2) 700 g of the base resin produced according to I o) are mixed with 600 g half-ester according to Example II o) and 50 g half-ester according to Example Ii a) unset, esterification is first carried out at a temperature around 110-120a, then - with toluene as a solvent - the further esterification takes place at a temperature above 150 °. As soon as the reaction mixture has an acid number below 20, a vacuum is applied and at an increased temperature of up to 1800 in a vacuum at 20-30 Torr heated after all solvent and volatile at lower temperature Components have been removed.

After at least two hours of vacuum treatment, the resulting yellow resin cooled under vacuum and then - at about 70-80 ° - in half the amount its weight in styrene. solved. The solution is particularly easy and smooth. The solution proves to be highly compatible with other styrene additives.

The hardening product obtained in a known manner is also at room temperature tough-elastic and can be cut with a knife, like 3) With the same basic resin weight / with Experiment 2) 500g of the according to Example 11 o) and 120 g of Example II d) produced half-esters are used. With gentle pre-esterification - use of the catalyst according to example 1) and benzene as the circulating medium - one succeeds in producing one highly viscous resin, which still easily dissolves in styrene and can be easily diluted with styrene is.

In the hardened state, the resin alu clearly proves itself. elastic and easy to cut, but visibly more viscous than the product according to example 2.

4) 600 g of a base resin still containing some solvent, produced according to example I a), are produced with 300 g of one according to example II a) Half ester with an acid number of about 280 and 5 g mixed catalyst according to the example 1 offset and carefully fused. Under initiating a weak standing C02 strosa a vacuum of @o to 100 mm is applied. Distilled from the melt The xylene contained in it quickly evaporates, followed by condensation water. At a The temperature drops from 1100 to about 100-110 at the beginning transmitting The acid number drops rapidly and has fallen to a value of 25 after just 9 hours. You can now either continue the vacuum distillation under these Betingungen and receives after another 3 hours - with an acid number of the undiluted resin from about 22 - when dissolving in half the weight of Monostryrol a resin solution of noticeably light color, the viscosity of which - measured in a 4 mm DIN cup at 200 - 200 see.

On the other hand, one can use distillation. at one increased to 1500 Continue temperature and then receive - with elimination of some cyclohexanol highly viscous, light, extremely tough resin with an acid number of 21, its viscosity according to Dissolving in 45% styrene is still 250 sec.

If, however, about 30 g of ethylene glycol are added to the product, which has decomposed in a vacuum and esterifies under the previous conditions, the acid number also falls to less than 15. By briefly increasing the vacuum (to 15mm) and the temperature (at 145-150 °) the rest of the glycol) oa. 20 g) distilled off. The remaining bright resin dissolves easily in styrene and delivers. solved in the ratio 2 t 1, a Product of viscosity 180 resin All so in different ways and with Esterification products of the same reaction mixture obtained with different properties9 whose properties are only modified in the last phase of esterification, can be cured excellently and result in light, hard and dry curing products with a beautiful, smooth surface.

According to the invention, aleo is obtained through a vacuum condensate low temperature surprisingly quickly to the goal and still maintains far Influence on the technical resin properties of the reaction product.

5) (Implementation of an amino alcohol backbone with an end group and some "bridge images") 500 g of the according to I d). with the use of amino alcohols The basic frameworks produced are intt 300 g of one from 1, - kg maleic anhydride and 1.1 kg of benzyl alcohol analogous to II a) and 40 g of the end group prepared according to II d) obtained two-half esters with additional clay, 5 g mixed catalyst and implemented under the bath conditions of Example 4. being during the vacuum condensation how there a small Mangs ethylanglycol (40 g) is gradually added. To Diploma of vacuum treatment in the temperature range from 110 - 1500 the result is a brownish-yellow, very tough resin, which is still at 50 - 600 initially dissolved with 10% of its own weight in diallyl phthalate and then with more 40% of its own weight in monostyrene (i.e. to a total content of 33.3% Monomers) can be diluted.

The clear, viscous solution hardens after adding 2% dibenzoyl peroxide at temperatures above 70-80 ° quickly to tough, hard, elastic products which gain in hardness and elasticity when post-tempering at 100 - 1200C and have dry surfaces.

The influence of the various end groups is clearly divided into that the esterification product according to Example 1 in industrial processing as Impregnating resin has a particularly beautiful flow and excellent dielectric values (especially low dielectric losses) with great hardness. Is created by exchanging the End group IIa) taken the end group IIb), the result is an elasticized, dielectric but inferior product with less flow, but better compatible with styrene is. As mentioned, the product according to Example 2 is highly elastic and can be cut as a result of the long-chain end groups with oleyl residues, which also reduces its solubility in styrene.

The foils made from it stick together above 80 ° under pressure together. On the other hand, the water absorption is very low, and the dielectric values are almost constant within wide limits.

The polyesters obtained according to the invention have primarily Importance as impregnation, casting and transferring resins. They are generally used in Immersion, pouring or spraying processes, especially for covering or embedding processed by electrical conductors.

In the solution of the monomer, the Estßr are long-lasting and will preferably traded in this form. The hardening takes place through the addition of a catalyst, hardening can be accelerated by adding siccatives or by heating can. The material mixed with siccatives can also be used as a baking agent. Because of their good electrical properties, especially their high insulation properties the polyesters according to the invention are primarily suitable for electrotechnical applications Purposes.

Claims (6)

P a t e n t a n s p r ü c h e: i.) Method of manufacture not linear, unsaturated, hardenable resins of polyester character used in copolymerizable Monomers are soluble, characterized in that initially on the one hand so-called Basic structures, i.e. polyvalent and side-chain hydroxyl groups bearing ( neutral, saturated or unsaturated compounds through co-condensation of polybasic, saturated, unsaturated or aromatic carboxylic acids with polybasic Hydroxyl compounds in excess, and on the other hand so-called end groups, i. monovalent, acidic, saturated or unsaturated compounds of relative low molecular weight by esterifying dicarboxylic acid anhydrides in excess with monohydric alcohols, amino alcohols or amines, whereupon the two components, of which at least one must be unsaturated, into one practically neutral, branched unsaturated compound esterified with one another will. 2.) Method according to claim 1, characterized in that the structure the backbones instead of polyhydric alcohols wholly or partially amino alcohols or amines can be used. 3.) Method according to claim 1, characterized in that as monofunctional acidic end groups also proportionally saturated, unsaturated or aromatic monocarboxylic acids or their derivatives are used. 4.) Process according to claims 1 to 3, characterized in that that the used monofunctional acidic compounds which eu end groups are determined proportionally by bifunctional or higher acidic compounds be replaced - as they are made of two moles of dicarboxylic anhydride and one mole of one hydrofluoric alcohol, amino alcohol or an imine can be obtained -which as Bridge members are used to achieve higher molecular weights. 5.) Process according to claims 1 to 4, characterized in that that the esterification in vacuo at temperatures below 150 ° preferably by about 110 ° takes place. 6.) Method according to claims 1 to 5, characterized in that that the condensation products from available various basic structures and various end groups are produced