DE4436095A1 - Epoxy] resins with good solubility in xylene and toluene etc - Google Patents

Abstract

Epoxy resins (I) (claimed), contains bisphenol cpds. in which at least one of the aromatic rings is substd. with linear or branched opt. substd. alkylene with at least one aryl gp.. Also claimed are: (i) a two-stage process for the prodn. of modified epoxy resins by (a) reacting a bis-phenol with an alkenyl-aromatic cpd. in presence of a weak acid, opt. adding more of the same or another bisphenol and (b) reacting with an epoxide; (ii) a one-stage process for the prodn. of modified epoxy resins by reacting a mixt. of aralkylated and non-aralkylated bisphenols with an epoxide; (iii) modified epoxy resins obtd. by these processes.

Description

The invention relates to epoxy resins from aralkylated diphenols and diepoxides or from aralkylated diphenols and epichlorohydrin, a process for their Manufacture as well as their use.

Resins with epoxy groups are generally known (H. Lee, K. Neville in "Handbook of Epoxy Resins", Reissue 1982, McGraw-Hill Book Company, New York; C.A. May in "Epoxy Resins," Marcel Dekker, Inc., New York and Basel, 1988). For example, they can be made by implementing more valuable phenols with epichlorohydrin in the presence of sodium hydroxide or through Addition of bis-phenols to bis-epoxides. These relatively low molecular weight Reactive resins are widely used in material applications because of a high degree of Variability of the properties by modification of the epoxy and phenol Basic body is accessible.

The known, technically accessible epoxy resins are not all or not sufficiently soluble in aromatic solvents, but only in the (considerably more expensive) aliphatic esters and ethers such as B. butyl acetate, Methoxypropanol, ethylene glycol monobutyl ether and diethylene glycol dimethyl ether.

The object was therefore to provide epoxy resins which are aromatic Solvents such as xylene or toluene are soluble, and the excellent Offer level of properties of the known epoxy resins.

According to the invention, this object could be achieved by at least one part of the bisphenols commonly used to prepare the epoxy resins aralkylated bisphenols was replaced.  

The invention therefore relates to epoxy resins containing bisphenol compounds attached to at least one of the aromatic rings via each a linear or branched, optionally substituted alkylene radical are connected to at least one aryl radical. The proportion of these aralkylated Bisphenol compounds according to the invention is between 10 and 90%, preferred between 20 and 80%, and particularly preferably between 30 and 70% of the Total mass of bisphenol compounds for the production of the epoxy resin be used. The rest of the bisphenols are the usual ones used, non-aralkylated bisphenols. It is also within the framework of the Invention possible in combination with the above-mentioned proportions of aralkylier bisphenols aliphatic diols instead of the unsubstituted bisphenols to use. Furthermore, it is possible within the scope of the invention to reduce the Part of the bisphenols and / or diepoxide compounds to be replaced by Polyphenols with three or more hydroxyl groups or polyepoxide compounds, which contain three or more epoxy groups in the molecule. Likewise, a small part of the bisphenols and / or the diepoxide compounds monohydric phenols or monoepoxides can be replaced.

In particular, such epoxy resins are the subject of the invention in which a Part of the bisphenol compounds carries an aralkyl radical on average. The share of this According to the invention, monosubstituted bisphenol compounds are between 10 and 90%, preferably between 20 and 80%, and particularly preferably between 30 and 70% of the total mass of bisphenol compounds used for the production of the epoxy resin can be used.

The synthesis of the bisphenols for the epoxy resins according to the invention are used is in the simultaneously filed patent application Az Hoe 94 / K 61.  

The bisphenols which are suitable for the invention are reaction products of dihydroxyaromatics with aromatics which carry an alkenyl group. It can the alkenyl group is also part of a fused cycloaliphatic Be ring containing an endocyclic or exocyclic double bond. The Aralkylation is preferably carried out so that the bisphenol used after the reaction carries an aralkyl residue on average. Examples of more suitable Bisphenols are reaction products of bisphenol A, bisphenol F, which isomeric dihydroxybenzenes and dihyxdroxynaphthalenes, dihydroxydiphenyl ether, Dihydroxybenzophenone and dihydroxydiphenyl sulfone. Suitable alkenyl aromatics have 8 to 15 carbon atoms and contain at least one aromatic Ring and exactly one alkenyl group. Examples are styrene and its homologues, Isopropenylbenzene, Inden and Diphenylenäthylen.

The reaction of the aralkylated bisphenol component, optionally in Mix with unmodified bisphenols to the corresponding epoxy Resins can be made in various ways, as is known to those skilled in the art:

• 1. Chain-extending addition (taffy process) with epichlorohydrin as Epoxy component, the middle of the excess of epichlorohydrin Molar mass of the reaction product is controllable. If necessary, a further build up by subsequent addition of bisphenols.
• 2. Reaction with bisepoxides (diglycidyl ethers), also with mixtures of different diglycidyl ethers as epoxy components, so-called "Advancement" reaction, (preferably the molar mass is Diglycidyl compounds per 1 epoxy group on average 100 to 525 g / mol).

In all reactions there is a residual content of epoxy groups in the resin aimed at an "epoxy equivalent weight" (molar mass divided by  Number of epoxy groups) from 180 to 5000 g / mol, preferably from 230 to Corresponds to 2000 g / mol.

The diglycidyl ethers suitable for the invention have a number-average mol mass (Mn) of about 300 to 7000 g / mol and an epoxy equivalent weight of about 150 to 3500 g / mol. Examples of this are implementation products from Epichlorohydrin or methylepichlorohydrin with bis (hydroxyphenyl) methane (Bisphenol F) or 2,2-bis (4-hydroxypheny) propane (bisphenol A), butane-1,4- diol, hexane-1,6-diol, bis (hydroxymethyl) cyclohexane, polyoxypropylene glycol with an average molecular weight of 200 to 4000 g / mol and with dihydroxy benzophenone, dihydroxy-naphthalene and resorcinol. Diepoxides with suitable Molar mass are determined either by selecting the proportions of Bisphenol and epichlorohydrin or by reaction of the monomeric diglyci dyl compounds with further bisphenol with the addition of catalysts such as Lewis acids, Lewis bases or phosphonium salts. As part of the The aralkylated bisphenols described above can also be used in the invention use the synthesis of diglycidyl compounds.

A detailed list of suitable epoxy compounds can be found in the manual "Epoxy Compounds and Resins" by A.M. Paquin, jumper Verlag Berlin 1958, Chapter IV and in the above manuals.

The modified epoxy resins according to the invention can be in one represent two-stage process, the first stage being a non-aralkylated Bisphenol component in the presence of weak acids at temperatures from 100 to 160 ° C, preferably from 120 to 155 ° C, with the alkenyl aromatic Component is implemented. The second step is with an epoxy component implemented, using both of the above-mentioned process variants can.  

In a one-step process for the production of the modified epoxy resins a mixture of an aralkylated and a non-aralkylated bisphenol component implemented together with an epoxy component.

The bisphenols listed above can be used individually or as a bisphenol component can be used in a mixture. The term "bisphenol component" includes in Within the scope of the invention also the addition of trihydric or polyhydric phenols, and monohydric phenols in a small amount to the bisphenols. The The amount added is less than 5%, preferably less than 2%, based on the mass of the bisphenol component.

The modified epoxy resins according to the invention can be used, for example Use the production of casting resins, adhesives and injection molding compounds, optionally in combination with customary inert fillers, such as chalk, kaolin, Wood flour, mica or glass balls, or with fibrous reinforcing materials such as glass, aramid, carbon or metal fibers.

In the examples below, all contents, parts and percentages mean Information in each case mass contents, unless expressly stated otherwise.

Examples Example 1

A is added to B and C under nitrogen at 120 ° C Add D at the beginning of 120 ° C in such a way that the temperature of the now following exothermic reaction from the dropping rate between 120 ° C and 160 ° C (maximum temperature!) is maintained. After the addition is complete heated to 190 ° C for two hours, the degree of conversion being determined using Solid state determinations controlled (2g substance / 2g xylene; 1h at 160 ° C in Convection oven). After cooling to 120 ° C., E is added, followed by F. Bei As the reaction begins, the temperature rises to 160 to 170 ° C. To to reach the theoretical epoxy equivalent weight is at 160 ° C. held.

Epoxy equivalent weight: 670 to 690 g / mol
Viscosity at 25 ° C / 40% in butyl diglycol: 480 to 510 mPas

Example 2

A is added to B and C under nitrogen at 160 ° C Add D at 160 ° C initially in such a way that the temperature of the now following exothermic reaction from the dropping rate between 155 ° C and 165 ° C is maintained. After the addition is over two hours heated to 160 ° C, the degree of conversion is based on Solid state determinations controlled (2g substance / 2g xylene; 1h at 160 ° C in Convection oven). Additional amounts of oxalic acid may be required. After cooling to 100 ° C, the melt is taken up by E, followed by F dissolved in G at 60 ° C. After stirring for 60 minutes at 70 ° C. in 120 Minutes the addition H at 80 ° C and about 500 hPa in such a way that a simultaneous azeotropic drainage takes place. Then it is under vacuum and Temperature increase epichlorohydrin distilled off (maximum temperature: 120 ° C, Reduce the pressure to 50 hPa). The mixture is left at 120 ° C. and 50 for 30 minutes hPa and then adds H under the same conditions in 30 minutes. You cool below 100 ° C, releases the vacuum, then adds 1 and stirs intensely 15 Minutes at 95 ° C. The aqueous phase is separated off. With stirring, based on the measured hydrolyzable chlorine content, one and a half times Amount of 4% sodium hydroxide solution added. At 90 ° C for 90 minutes stirs. It is dissolved in J and the aqueous phase is separated off. With K becomes a pH between 6.0 and 7.2, dewatered under azeotropic conditions, draws off about 50 ml of xylene and filter. Under vacuum (up to 50 hPa) and at The solvent is removed at a maximum of 150 ° C.

Epoxy equivalent weight: 290 to 295 g / mol
Total chlorine content: <0.4%
Hydrolyzable chlorine content: <0.1%
Viscosity at 25 ° C: 55,000 mPas

Example 3

A is added to B and C under nitrogen at 120 ° C Add D at the beginning of 120 ° C in such a way that the temperature of the now following exothermic reaction from the dropping rate between 120 ° C and 130 ° C (maximum temperature!) Is maintained. After the expiry of the Addition is heated to 160 ° C for two hours, during which the degree of conversion controlled using solid state determinations (2g substance / 2g xylene; 1h at 160 ° C in a convection oven). After cooling to 120 ° C., E is added, followed by von F. In the reaction that now begins, the temperature rises to 160 to 170 ° C. Until the theoretical epoxy equivalent weight is reached Kept at 160 ° C.

Epoxy equivalent weight: 715-745 g / mol
Viscosity at 25 ° C / 40% in butyl diglycol: 720-750 mPas

Example 4

A is added to B and C under nitrogen at 160 ° C Add D at 160 ° C initially in such a way that the temperature of the now following exothermic reaction from the dropping rate between 155 ° C and 165 ° C (maximum temperature!) Is maintained. After the expiry of the Addition is heated to 160 ° C for two hours, during which the degree of conversion controlled using solid state determinations (2g substance / 2g xylene / 1 h at 160 ° C in a convection oven). Additions of oxalic acid may be required. After cooling to 120 ° C, E is added, followed by F in several Servings. In the reaction that now begins, the temperature rises to 160 to 170 ° C. Until the theoretical epoxy equivalent weight is reached Kept at 160 ° C.

Epoxy equivalent weight: 2000 to 2400 g / mol
Viscosity at 25 ° C / 40% in butyl diglycol: 2100-3000 mPas

Example 5

A is added to B and C under nitrogen at 120 ° C Add D at the beginning of 120 ° C in such a way that the temperature of the now following exothermic reaction from the dropping rate between 120 ° C and 160 ° C (maximum temperature!) Is maintained. After the expiry of the  Addition is heated to 160 ° C for two hours, the degree of conversion controlled using solid state determinations (2g substance / 2g xylene; 1h at 160 ° C in a convection oven). After cooling to 120 ° C., E is added, followed by von F. In the reaction that now begins, the temperature rises to 160 to 170 ° C. Until the theoretical epoxy equivalent weight is reached Kept at 160 ° C.

Epoxy equivalent weight: 705 to 735 g / mol
Viscosity at 25 ° C / 40% in butyl diglycol: 550 to 580 mPa · s.

Claims (8)

1. Epoxy resins containing bisphenol compounds, which at least one of the aromatic rings of the bisphenols via a linear or branched, optionally substituted alkylene radical with at least one Aryl radical are connected. 2. Epoxy resins according to claim 1, containing aralkylated bisphenol compound in a proportion between 10 and 90% of the total mass of bis phenolic compounds that are used to manufacture the epoxy resin. 3. Epoxy resins according to claim 1, containing aralkylated bisphenol compound that an aralkyl per 1 mol of the bisphenol compound wear substituents. 4. Epoxy resins according to claim 1, characterized in that the Aralky substituent is selected from aralkyl radicals with 8 to 15 carbon atoms. 5. Two-stage process for the production of modified epoxy resins, characterized in that in the first stage the bisphenol component with the alkenyl aromatic component in the presence of a weak acid is implemented, and then optionally after adding another Amount of the same or another bisphenol component with an epoxy component is implemented. 6. One-step process for the production of modified epoxy resins, characterized in that a mixture of an aralkylated bisphenolcom  component and a non-aralkylated bisphenol component together with one Epoxy component is implemented. 7. Modified epoxy resins, produced by one of the methods according to Claim 5 or 6. 8. Use of modified epoxy resins according to claims 1, 2 and 7 for the production of casting resins, adhesives, injection molding compounds, filled and (fiber) reinforced construction resins.