DE1266500B - Process for the production of largely amorphous polyamides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C 08g

German KL: 39 c -10

(\ :, ΐ.ΒΙ. I

Iv; ι IS

Number: 1266 50O ₁ (UIcIi _- S

File number: G 32491IV d / 39 c Filing date: June 14, 1961 Opening date: April 18, 1968

Polyamides are already known which are made from terephthalic acid and diamines with at least 6 carbon atoms. Both when using straight-chain diamines such. B. decamethylenediamine, as well as methyl-substituted diamines, such as. B. 3-methylhexamethylenediamine, crystalline fiber-forming products are obtained as the diamine component. When using aromatic diamines, e.g. B. m-xylylenediamines, transparent amorphous polyamides are only obtained if the acid component contains terephthalic acid at least 50 mol percent isophthalic acid. However, these polyamides become cloudy and opaque even when heated to temperatures well below 100 ^{° C .;} In addition, they are insoluble in commercially available solvents such as alcohol or chloroform, so that they are unsuitable for the production of adhesive mixtures or paint solutions.

It has now been found that largely amorphous polyamides can be produced by condensation of terephthalic acid and / or isophthalic acid and its amide-forming derivatives with C-alkyl-substituted aliphatic oc, co-diamines or their amide-forming derivatives if the diamine component is 2-ethylhexamethylenediamine, 3-ethylhexamethylenediamine , 3-ethylheptamethylenediamine, 4-ethyl-octamethylenediamine or their amide-forming derivatives are used. The condensation takes place with essentially equimolar amounts of terephthalic acid, isophthalic acid or mixtures thereof. Instead of the free acids or diamines, amide-forming derivatives of diamine or acids, e.g. B. the diformyl derivatives of diamine or esters of acids with volatile alcohols can be used.

Although the polyamides produced according to the invention are very similar in chemical structure to the polyamides already known, they have a number of strikingly different characteristics which differ from the named polymers produced in a known manner. The most striking properties of these polyamides produced according to the invention are their transparency and their crystal-clear appearance, which persist even after repeated prolonged heating and slow cooling. These polymers produced according to the invention are completely amorphous and their amorphous state is thermodynamically stable. These polymers soften within a wide temperature range, usually from about 20 to 4O ⁰ C, and are particularly well suited to molding and other molding process for this reason. They are not just processes for the production of largely amorphous polyamides

Applicant:

W. R. Grace & Co., Cambridge, Mass. (V. St. A.)

Representative:

Dr. rer. nat. J.-D. Mr. v. Uexküll, patent attorney, 2000 Hamburg 52, Königgrätzstr. 8th

Named as inventor:

Rudolf Gabler, Zollikerberg (Switzerland)

Claimed priority:

Great Britain 8 May 1961 (16 728)

soluble in typical polyamide solvents such as sulfuric acid, formic acid, phenol and cresol, but also swell in lower alcohols, e.g. B. methanol, ethanol and isopropanol, extraordinary and result in honey-like, pourable masses that are used for the production of coatings and adhesives very suitable. They have excellent tear resistance, impact resistance and flexibility. In contrast to known polyamides, on the other hand, they have very low extensibility. These This property, combined with their completely amorphous nature, makes them man-made Textile fibers not suitable.

As stated above, terephthalic acid, isophthalic acid or mixtures of these acids are used Production of the polyamides mentioned is used. The fact that mixtures of these acids are used to produce such polyamides can be used is extraordinarily unexpected as it is common when using mixtures of these acids for the production of super polyamides products which have much lower melting points and are generally less desirable Have properties than the corresponding polyamides made from only one of the acids.

The polyamides made according to the invention are clear and translucent and generally have a bulk

809 539/412

3 4

the same properties, whether it compensates for it under the use of spherical pressure; this is done reaches these two acids produced 25O ⁰ C mixtures in derdung of terephthalic acid, of isophthalic acid or the same time, in which the inner temperature.

became. The terephthalamides are generally The melt is now pressureless for 3 ¹ Z

preferred for most purposes, since their melting point is heated ^{to a temperature of 280 ° C}

points by 50 to 100 ° C higher and their mechanical characterization of the polyamide is the 'tempe-

Properties somewhat more favorable than those of the corresponding temperature kept constant for a further 2 hours

the isophthalamides. The melting points and and the melt in cold water with the help of

mechanical properties of the extruded using nitrogen in order to produce cylin-

The polymers produced from the mixture take an io-drical rods to obtain. The polymer is durca-

Intermediate position between those of the two types, has a melting point in the range of

of homopolymers. 180 to 200 ⁰ C and has a viscosity of 1.2.

Of particular interest are polyamides made from These rods have good physical and mechanical properties

Mixtures of acids with a small amount of iso properties. You can use a knife without

phthalic acid, advantageously one of those 15 to be crumbled, cut, they are tough and

no more than about 5 or at most 10% of the solid and have a very high impact resistance. That

full acidity. This mixed polyamide polymer can be melted and extruded

melt at temperatures that are only slightly below or processed in the injection molding process. IT

the melting temperatures of the corresponding Tereph- can also be cast or toughened in some other way,

thalamide polymers, and are processed in relation to 20 transparent packaging films,

their mechanical properties differ from the pure ...

Terephthalic polyamides indistinguishable. From B e 1 s ρ 1 e 1 III

For this reason, the production of polyamides, the salt of isophthalic acid and 3-ethylhex | -

which is made from a mixture with lower isophthalmethylenediamine according to that in Example | l

Acid content are made up of a preferred 25 described method.

Form of the invention. 30 g of this salt are in a thick-walled

In the following examples, parts mean Ge glass tube melted in a nitrogen atmosphere

important parts. and heated for 5 hours at 28O ⁰ C. Nadh

Example I cooling the pipe is opened, and after pouring off

The pipe becomes 30 of some condensation water

2.03 g of terephthaloyl chloride are in 100 ml of tetra again in a stream of nitrogen during further

Dissolved chlorocarbon and heated ^{at 250 to 280 0} C in a rotating 3% hours. In the end

Shovel equipped mixer stirred vigorously. The tube is kept at the same temperature

this mixture is then given a solution of one hour under a pressure of 8.1 mm Hg.

Hold 1.5 g of 3-ethylhexamethylenediamine and 1.3 g of potassium 35 and then refrigerate.

add hydroxide in 200 ecm of water at once. The light-colored, transparent polyamide thus obtained forms immediately in a practically quantitative amide, melts at 130 to 150 ° C. and has a viscosity yield in the form of a white powder. It gets from 0.8. In addition to the low melting point and stirred for a further 3 minutes, then filtered off with suction, the polyamide produced several times with methanol and then with water has similar properties, washed and dried. This gives 2.5 g of polyamide as that of Example II. It finds particular having a melting point of 180 ⁰ C and an abso- for the production of liquid coating and Klebstoffluten viscosity of 0.72. It can be melted and composites use.

be poured into clear and translucent rods.

₄₅ B e 1 s ρ 1 e 1 IV

EXAMPLE II _Using the procedure of Example U, 16.6 parts of terephthalic acid are mixed with 30 ml of water, 16.6 parts of a mixed acid with 90% te-

mixed and put together on a steam bath to almost boiling rephthalic acid and 10% isophthalic acid

brought. With the help of a dropping funnel, 15.5 parts of 2-ethylhexamethylenediamine are then added to

a solution of 15.5 parts of 2-ethylhexamethylene 50 position of the salt used. That through the poly-

diamine in 50 ml of alcohol is slowly added dropwise, the polyamide produced in the condensation stage is through-

which finally leads to the complete dissolution of the sight and crystal clear. It melts within one

Terephthalic acid. After cooling, the precipitated terephthalic range of 160 to 180 ⁰ C and has a viscosity

thalic acid salt of 2-ethylhexamethylenediamine in the form of 1.0.

of colorless crystals. 55 The polyamide of this example is in its mecha- A mixture of 300 g of the salt obtained above, niche properties from that of Example II not 100 ml of water and 0.5 g of glacial acetic acid is to be distinguished under permanent and suitable for the same purpose Stir and dissolve under vacuum in a one to one solution. .
container of a stainless autoclave from 11 to 140 ⁰ C Example V
heated, resulting in complete dissolution of the salt 60. The procedure of Example II is shown below. With the aid of pure nitrogen, the solution turn is transmitted by 16.6 parts of a mixed acid through a filter in an oven preheated to 25O ⁰ C and 40 ° / o of terephthalic acid and 60% isophthalic acid autoclave. The temperature within the autoclave together with 15.5 parts of 2-ethylhexamethylenedides then falls to 160 to 180.degree. After amine carried out to produce the salt. The rewarming increases the pressure and the temperature generated by the polycondensation process quickly rises again. By opening the valve amid is transparent and crystal clear, it melts inside the lid of the autoclave, the water vapor is half a range from 130 to 150 ⁰ C and has a drained, so that the pressure with the atmo viscosity of 0.8. In its properties it is that

Polyamide produced according to Example III is very similar, and it is also used for the production of liquid coatings and Adhesive compositions are particularly well suited.

Example VI

By carrying out the procedure described in Example II, 16.6 parts of terephthalic acid are obtained and 16.5 parts of 3-ethylheptamethylenediamine for preparation of the salt used. That through the polycondensation reaction The polyamide produced is transparent and crystal clear, it melts within a range of 165 to 185 ° C and has a viscosity of 0.95. The polyamide thus produced has the same properties as that according to Example II manufactured polyamide and is very suitable for the same applications.

Example VII

Following the procedure of Example II, the salt is prepared with 16.6 parts of terephthalic acid and 17.5 parts of 4-ethyloctamethylenediamine. The polyamide obtained is transparent and crystal clear. It melts at a ^{temperature between 120 and 140 °} C. and its viscosity is 1.0. It is particularly suitable for the production of flexible packaging films.

Example VIII

A polyamide was prepared using the procedure described in Example II using a salt of 16.6 parts of isophthalic acid and 16.5 parts of 3-ethylheptamethylenediamine. The polyamide formed by polycondensation of the salt is transparent, clear, it melts within a range of 110 to 130 ° C and has a viscosity of 2.2 l in ° / _o sulfuric acid. The polyamide produced in this way has the same properties as the polyamide produced according to Example III and is suitable for the same applications.

Unexpected technical advantages of the polyamides produced according to the invention over known ones Polyamides can be seen from the following comparative tests.

Polyamides are prepared using the procedure described in Example II. Man uses terephthalic acid and the following substituted polymethylenediamines for this purpose: 3-methylenhexamethylenediamine, 3-methylheptamethylenediamine, 4-methyloctamethylene diamine and 2,5-dimethylene hexamethylene diamine. The products thus obtained are made with several polyamides, the preparation of which is described in the preceding examples was compared. The comparison results are summarized in the following table:

example Used diamine Enamel
Point
⁰ C Optical
properties Crystallinity Usable
as textile fibers I. 3-ethylhexamethylene 180 transparent amorphous no II 2-ethylhexamethylene 180 to 200 transparent amorphous no VI 3-ethylheptamethylene 165 to 85 transparent amorphous no VII 4-ethyloctamethylene 120 to 40 transparent amorphous no Comparison attempt I. 3-methylhexamethylene 270 to 280 opaque crystalline Yes II 3-methylheptamethylene 220 opaque crystalline Yes III 4-methyloctamethylene 245 opaque crystalline Yes IV 2,5-dimethylhexamethylene .. 285 opaque crystalline Yes

The polyamides produced according to the invention have properties which are unexpected differ from the polyamides produced according to comparative experiment I to IV. The sudden one Change from opaque, crystalline, textile fiber-forming polyamides to crystal clear, complete amorphous resins, which cannot be deformed into textile fibers, as an apparent function small changes in the structure could not be foreseen.

Compared to the also initially amorphous and transparent polyamides of isophthalic acid and m-xylylenediamine produced according to German patent specification 1,019,822, the polycondensates produced according to the invention are surprisingly distinguished by the fact that they remain completely clear when they are set to 100 to 140 for 6 months ⁰ C, while the previously known products become opaque and cloudy after 20 hours of heating to 6g at temperatures of 40 to 50 ° C. The condensates according to the invention are thus completely boil-proof. In addition, they are soluble in common solvents, so that they are suitable for the production of adhesive and lacquer solutions.

Claims (1)

Claim: Process for the production of largely amorphous polyamides by condensation of terephthalic acid and / or isophthalic acid or its amide-forming derivatives with C-alkyl-substituted aliphatic , co-diamines or their amide-forming derivatives, characterized in that the diamine component is 2-ethylhexamethylenediamine, 3-ethylhexamethylenediamine -Ethylheptamethylenediamine, 4-Äthyloctamethylenediamine or their amide-forming derivatives are used. Considered publications:
German Auslegeschrift No. 1 019 822;
French Patent No. 845,691;
British Patent No. 794 365;
U.S. Patent No. 2,752,328;
Chemisches Zentralblatt, 1959, p. 5336. 809 539/412 4.68 © Bundesdruckerei Berlin