DE1959625B2 - METHOD OF MANUFACTURING EYEGLASSES FROM EPOXY RESINS - Google Patents

Description

R ¹

(D

R - NH - I,). -1 CH L- (CH,), - NH ₃

ok

"5

in which R is a cycloalkyl group with up to 10 carbon atoms, in particular such a cyclohexyl group, which is optionally substituted by halogen, alkyl (preferably with 1 to IOC atoms) or aryl (preferably phenyl), monosubstituted or polysubstituted, R ^{1 is} alkyl with 1 to 10 carbon atoms, cycloalkyl with up to IOC atoms or cycloalkylalkyl with up to 10 carbon atoms in the alkyl group, χ and ζ are 0 or an integer from 1 to 10 and y is 0 or 1, but x , y and ζ cannot be 0 at the same time, mixed with polyepoxides, preferably conventional mixtures of glycidyl ethers of bisphenol A [22-DHp-hydros) phenyl) propane], and the mixture obtained is poured.

2. The method according to claim 1, characterized in that a polyamine of the general formula

NH - (CH ₂ I ₁ - NH ₂

in which χ is an integer from 1 to 10, preferably 2 to 5, in particular 3, mixed with the polyepoxides and the mixture obtained is cast.

3. The method according to claim 1 or 2, characterized in that a conventional mixture of Glycidyl ether. of bisphenol A of the formula

/ \
CH ₂ -HC-CH ₂

CH ₃

CI ₃

OH

I 0-CH ₂ -CH-CH ₂ CH ₃

CH ₃

-H ₂ C

in which compounds with η = 0 to 80 to 90 percent by weight, compounds with η = 1 to 6 to 12 percent by weight and compounds with η = 2 to 1 to 3 percent by weight, possibly in addition to small amounts, for example less than 2 percent by weight, higher homologues are included , is mixed with the polyamines.

4. The method according to claim 3, characterized in that the mixture additionally at least trifunctional polyepoxides in an amount of 3 to 10 percent by weight, preferably 3 to 7 percent by weight, based on the mixture to be poured.

5. The method according to any one of claims 1 to 4, characterized in that the cycloaliphatic Polyamine, based on polyepoxide, in at least a stoichiometric amount (1/3 mol of polyamine per Epoxy equivalent), at most 1.5 times the stoichiometric amount, preferably in the 1.1 to 1.2 times the amount of the stoichiometric amount is used.

6. The method according to any one of claims 1 to 5, characterized in that the mixture is cured ^{between 5 hours at 6O 0} C and 10 minutes at 140 ^{0 C after casting.}

The invention relates to the production of spectacle frames and their individual parts from organic Plastics. Inexpensive cellulose acetate eyeglass frames are mass-produced by molding in Molds made. This process can be used to insert reinforcement inserts or hinge parts into the cast Work in the glasses frame at the same time and easily, so that additional drilling, milling, Screwing in or any other mechanical auxiliary work is not required. Furthermore, the nose bridge and / or the nasal bridge plates are cast on in a single operation.

However, molded spectacle frames made of thermoplastics are not sufficiently scratch-resistant. and rigid and also too heavy. In order to avoid these disadvantages, the patent proprietor already the use of organic, through incorporation or addition of substances from long-chain aliphatic molecular groups with about j 0 carbon atoms upwards either to the liquid resin or as a hardener or as a third component for the plastic mixture flexibilized thermoset Plastics, in particular epoxy resins, unsaturated polyester resins or the like, for casting spectacle frames or individual spectacle frame parts in molds.

beaten. As a result of the chemical bonding of the flexibilizing additives in the thermoset Plastics do not show any migration of the plasticizer, and there is also no disadvantage accept the surface gloss of the workpiece over time. Spectacle frames manufactured in this way or individual eyeglass frame parts are consistently lighter and harder because of the plastic used and more resistant to scratching and bending than eyeglass frames made from conventional thermoplastics. Furthermore is the thermal rebendability is greater than that of conventional thermoplastics. Not opposite modified thermosets, the plastic used has improved impact resistance.

According to a further development of this proposal, the patent proprietor also recommended using epoxy resins made more flexible by chemically incorporating cycloaliphatic compounds for casting spectacle frames or individual spectacle frame parts in molds, since more temperature-resistant spectacle frames with even better mechanical properties, in particular flexural strength, can then be produced which are also practically completely colorless. In practice it has been shown that, above all, those cycloaliphatic amines which have both a primary amino group and a secondary amino group make it possible to achieve particularly valuable results, as is the case with l-I-foYahycimtwiTviamfnrfc-i-afninrk-nrnnaTl Ηργ

It is the object of the invention to increase the flexibility, the impact resistance, the aging resistance and the physiological compatibility of spectacle frames or individual spectacle frame parts made from epoxy resins. This is achieved in a method for producing spectacle frames from epoxy resins by casting mixtures of cycloaliphatic polyamines and polyepoxides, optionally containing curing accelerators, in ² S forms and curing the mixtures at elevated temperature, which according to the invention is characterized in that at least one polyamine of the general formula

^30th

R-NH- (CH ₂ I ₁ -

CH

in

(CH ₂ I ₁ -NH ₂

in which R is a cycloalkyl group with up to IOC atoms, in particular such a cyclohexyl group, which is optionally mono- or polysubstituted by halogen, alkyl (preferably with 1 to IOC atoms) or aryl (preferably phenyl), R ^{1 is} alkyl with 1 to IOC -Atoms, cycloalkyl with up to IOC atoms or cycloalkylalkyl with up to IOC atoms in the alkyl group, χ and ζ are 0 or an integer from 1 to 10 and y is 0 or 1, but x, y and ζ cannot be 0 at the same time, mixed with polyepoxides, preferably mixed mixtures of glycidyl ethers of bisphenol A [2,2-di- (p-hydroxyphenyl) propane], and the mixture obtained is poured.

The excellent mechanical strength values of epoxy resins produced in this way by curing polyepoxides with cycloalkylamino-aminoalkanes are probably due to the fact that initially only the primary amino group of the cycloalkylaminoalkane used and then the secondary amine group bonded to the cycloalkyl group with the polyepoxide used, in particular diepoxide, are below The formation of long chains reacts and only after these amino groups have been largely consumed do the secondary amino groups formed by the reaction of the primary amino groups with epoxy groups react with sterically favorable epoxy groups with crosslinking. CNe spatial density of crosslinking sites is is thus employed so as smaller, with ever greater excess the cycloalkylamino-amino-alkane, based on polyepoxide, This can be seen in the following two schematic representations, in which by the numbers!, 2 and 3 indicated arrows the chronological order of attack of the epoxy groups on the amino groups is illustrated

I ₂ I,

1. R-NH- (CH ₂ J ₃ -NH ₂

H U

2. R-NH- (CH) ₃ -NH ₂

The first reaction scheme applies to the use of an epoxy group per bound to a nitrogen atom hydrogen atom (V ₃ moles per ^Epoxydäqu: valent), the second reaction scheme, whereas for use per one epoxy group door each is true of two of the three bonded to a nitrogen atom of hydrogen atoms ⁽¹ Z ₂ moles of polyamine per epoxy equivalent). One will move between these two borderline cases within the scope of the invention. In this way, it is possible, by choosing the ratio of hardener (cycloalkylamino-aminoalkane) to polyepoxide, to determine the degree of crosslinking in the epoxy resin obtained in a very simple and reproducible manner, and to achieve flexural strengths and impact strengths that have not yet been achieved with eyeglass frames.

According to the invention, therefore, the cycloaliphatic polyamine, based on polyepoxide, is at least stoichiometric (V ₃ mol polyamine per epoxy equivalent), at most 1.5 times the stoichiometric amount, preferably 1.1 to 1.2 times the amount stoichiometric amount, used. In this way it is achieved with certainty that, when the mixtures of polyepoxide and cycloalkylamino-aminoalkane used harden, practically all epoxide groups are converted, which contributes to the physiological harmlessness of the spectacle frames produced. The physiological harmlessness of the spectacle frames produced in this way remains given in the case of an excess of hardener, since, compared to aliphatic amines, cycloaliphatic amines in the unreacted state are less irritating to the skin. Even if there is an excess of amine (less than twice the stoichiometric amount), the amine always reacts with the epoxy resin at least via the primary amine group, so that in no case free amine is present in the resin structure. This guarantees physiological harmlessness in every case.

In the context of the invention, the usual mixture of the glycidyl ether of bisphenol A is preferred a solcites mixture of glycidyl ethers of the general formula

CH ₂ -HC-CH ₂ - + -

CH ₃

OH

CH ₃

CH ₃

used, in which compounds with »ι = O to 80 to 90 percent by weight, compounds with η = 1 to 6 to 12 percent by weight and compounds with ti = 2 to 1 to 3 percent by weight, at best in addition to small amounts, for example less than 2 percent by weight, higher Homologues are included, since in this way the formation of long linear chains is favored at the beginning of the hardening process. If a ratio between cycloalkylaminoaminoalkane and diepoxide is maintained close to the stoichiometric ratio, it is advantageous if, according to the invention, at least trifunctional polyepoxides are additionally used in an amount of 3 to 10 percent by weight, preferably 3 to 7 percent by weight, based on the mixture to be poured, as this provides a further possibility of adjusting the degree of crosslinking in accordance with the desired mechanical properties.

However, the exclusive use of at least trifunctional polyepoxides is not possible, otherwise hard, brittle products are obtained.

In the context of the invention, the cycloaliphatic polyamine is preferably a polyamine of the general type Formula are saturated, the best results have been achieved so far.

With the French patent 1315 462 it has already been proposed to use loose layers in productive horizons, for example oil. Water or gas leading productive horizons, under Maintaining their permeability to solidify pure liquids or gases and for this purpose a Mixture of polyepoxides and hardeners for polyepoxides dissolved in solvents in the one to be solidified Bring formation. For this known process it is essential to have a solvent for polyepoxides and to use hardeners for this after the polyepoxides have reacted with the hardeners and washing out the solvent from the reaction product in the productive horizon a porous one To obtain support frame made of epoxy resin. For the effect to be aimed for in this known method it does not matter which compound containing active hydrogen atoms is used as a hardener for polyepoxides is used. According to this known proposal, they are preferred as hardeners for polyepoxides Amines, including the 1-cyclohexylamine-3-aminopropane which can be used according to the invention, can be used, but on the basis of the information in French patent 1 315462 it is not possible conclude that, especially when using cycloaliphatic amines, the amines to be used according to the invention Art as a hardener for polyepoxy glasses frames with the excellent ones mentioned at the beginning Properties can be obtained.

The invention is explained in more detail below by means of exemplary embodiments.

in which χ is an integer from 1 to 10, preferably 35 B is ρ ie 1 1

2 to 5, especially 3, is used. With cyclo- 100 parts by weight of a mixture of diepoxides

amino-aminoalkanes of this type, especially those based on bisphenol A (a mixture of glycidyl

ether the general formula

NH- (CH ₂ J _x -NH ₂

(la)

in which the free valences by hydrogen

/ \
CH ₂ -HC-CH ₂

OH

/
0-CH ₂ -CH-H ₂ C

55

in which mixture diepoxides with π = 0 to 88 percent by weight, the epoxides with π = 1 to 10 percent by weight percent and the epoxides with η = 2 to 2 percent by weight were present, the epoxy equivalent weight of this Mixture is 190) and 28 parts by weight with 1-cyclohexylamine-3-arnino-propane were mixed with one another, with diepoxide and diamine im stoichiometric ratio. The mixture obtained was in the usual manner after degassing Poured bubble-free in molds for glasses frames and cured for 1 hour at 100 ° C. The obtained spectacle frames had excellent mechanical Excellent strength values and excellent resistance to aging.

Example 2

The procedure was as in Example 1, with 100 parts by weight of the Genv-sches used in Example 1 from diepoxides and 32 parts by weight of that according to Example! l-cyclohexylamino used were used 3-amino-propane and the resulting mixture was cured for 45 minutes at 120 ⁰ C. The mechanical values determined on spectacle frames manufactured in this way were as follows:

Hardness (ball pressure)

«! Seconds l350kp / cm ²

10 seconds 1380kp / cm ²

determined according to DIN S34S6

Flexural strength U30kp / cm ²

determined according to DIN 53 452

Impact resistance 70 kg / cm ²

determined according to DIN 53 453

Dimensional stability according to V i c a t 103 to 108 "C determined according to VDE 0203

Dimensional stability according to

Martens 65 to & 8C

determined according to DIN 53 458

This combination of mechanical strength values is the best so far.

F ^! ir the mixture of cycloalkylamino-aminoalkanes and diepoxides used according to Example 2, the time-temperature diagram shown in the drawing applies to curing. For other mixtures

similar time-temperature diagrams can be worked out experimentally without difficulty.

The substances identified in the description and in the claims are as such not subject of the protection request.

For this purpose, 1 sheet of drawings

Claims (1)

Patent claims: \. Process for the production of spectacle frames from epoxy resins by casting mixtures of cycloaliphatic polyamines and polyepoxides, optionally containing curing accelerators, in molds and curing the mixtures at elevated temperature, characterized in that at least one polyamine of the general formula