DE1920043A1 - Homogeneous injectable mixtures of polyamides and hydroxyl-containing polyolefins - Google Patents

Description

FARBENFABRIKEN BAYER AG

LEVERKUS EN-Bayerwerk 1 8th APR 1989 Pttent-Abteiluni Sdt / lM

Homogeneous injectable mixtures of polyamides and polyolefins containing hydroxyl groups

The present invention "relates to new homogeneous sprayable Mixtures of polyamides and polyolefins containing hydroxyl groups and a process for their production.

Polyamides, like polycaprolactam, are characterized by high levels Tensile strength, toughness and stiffness. Disadvantageous for however, some uses are the decrease in flexibility at low temperatures.

In order to use polyamides that are more flexible at lower temperatures obtained, attempts have been made to mix polyamides with polymers that have a very low glass transition temperature. The properties of such mixtures, for example of polyamide und.Polyäthylen, are not very satisfactory because Polyamides are incompatible with other polymers and the polymers are therefore difficult to disperse in the polyamide.

The dispersibility of polyolefins in polyamides can be increased by adding dispersants during the production of the Mixtures or grafting of polyolefin and polyamide can be improved.

It is also known that products with improved notched impact strength at lower temperatures are obtained when the polyamides contain polyamide side chains grafted onto carboxy-containing copolymers of ethylene. Le A 12 156 - 1 -

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It has now been found that mixtures of polyamides are possible and hydroxyl-containing olefin copolymers such as less crystalline types of polyamide due to improved flexibility characterized by low temperatures. At the same time, they show an improved behavior similar to that of the more crystalline types Processing like good demoldability.

So there were homogeneous injectable mixtures of polyamides and polyolefins found consisting of

a) from 70 to 99.9% by weight of a polyamide and.

b) 0.1 to 30% by weight of a hydroxyl-containing polyolefin.

the about 60-90 wt.% of recurring units of the general formula

I ¹ I

-. C - C ■ -

and 10 -% of recurring units of the formula 40 wt.

c - c 4-I

consists,

wherein R ₁ , R ₉ * R ^ and Ri, can be the same or different and are hydrogen, a lower alkyl group or halogen,

4 wooei the polyolefin has a molecular weight in the range from 10 to 10- ^, and the homogeneous sprayable mixture has a relative solution viscosity (measured on a solution of 1 g of the mixture in 100 ml of m-cresol at 25 ⁰ C in an Ubbelohde-

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Viscometer) of at least 2.0

Hydrolyzed copolymers of ethylene and vinyl acetate are preferably suitable as hydroxyl-containing polyolefins. The polyolefins are 10-40% by weight of units of the formula.

H OH
ι ι

-C-C-

t I

HH

contain.

For the purposes of this invention, polyamides are those of high molecular weight Polyamides understood that are different from a monoaminomonacarboxylic acid with at least 6 carbon atoms or derived from a salt of a dicarboxylic acid and a diamine. Preferably the polycaprolactam is used.

The mixtures are said to 70 - besteien 99 * 9% by weight of polyamide..

The modified polyamides can be prepared by hydrolytic polymerization of the aminocarboxylic acids or theirs Derivatives or salts of dicarboxylic acids and diamines in Gagenwart of copolymers. The copolymers can be used together with the polyamide-formers Starting materials are added to the reaction apparatus. However, the dosage has proven to be advantageous Copolymers turned out to be in the slightly viscous polyamide melt at a later point in time.

The homogeneous injectable mixtures can still be obtained by intensive mixing of the polyamides with the copolymers and subsequent mixing Extruding this mixture can be obtained.

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The products become form bodies by z. B. injection molding or extrusion processed.

example 1

<£ -Gaprolactam is polymerized with 9% by weight of 6-aminocaproic acid and 0.09% by weight of glacial acetic acid for 1 hour at 200 ° C. with stirring in a nitrogen atmosphere. The temperature is then increased to 270 ° C. One hour after this temperature has been reached, 0.1; 1.0 to 5.0 wt.% Gave a saponified Copolyraeren of ethylene and vinyl acetate of molecular weight 20,000 and with an OH number of 255. After a further 6 hours, the melt is spun in the form of a bristle into a water bath and chopped up. The chopped material is extracted four times for 3 hours each time with water at 95 ° C. and dried in a vacuum drying cabinet at 100 ° C. for 24 hours. The granulate is injected into perm bodies on which the mechanical properties of the products are measured. The data are summarized in the following table. Number 4 is a comparative product made from pure polycaprolactam.

running Content of rel. Sol Limit bending stress viscosity kp / cm 1520 Ε module from the 27500 No. Polyolefin V rel
(1 g / 100
m-cresol
25 ⁰ C) at room at
_ml temp. -20 C
at 1520 Bending test 27900 Weight # . 3.58 1160 1475 kp / cm
at at "
Space-. -20 ⁰ C
temp. 25600 1 0.1 3.47 1140 1600 24400 29,800. CVJ 1.0 3.07 1000 24500 3 5.0 3.1 1190 24000 4th 0 -4- 24300 Le A 12 156

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Example 2

9 * 5 kg of polycaprolactam with a relative solution viscosity of 5.1, measured on a 1 # solution in m-cresol at 25 ° C, with 0.5 kg of a saponified copolymer of ethylene and vinyl acetate with a molecular weight of 20,000 and a OH number of 255 intensively mixed · This mixture is extruded, chopped up and injected into moldings. The products are characterized by good demoldability and improved flexibility at low temperatures.

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Claims (8)

Claims Homogeneous mix of polyamide and polyolefin that can be injected consisting of a) 70-99.9 wt. # of a polyamide and b) 0.1 -. 30 wt $> a hydroxyl-containing polyolefin that at 60 - 90 wt. $ from recurring units of the general formula -4c I R, • C -I- R, and to 10
formula - 40 wt. $> From recurring units of OH I c + consists,
where R R- * and R. be the same or different and can represent hydrogen, a lower alkyl group or halogen, the polyolefin having a molecular weight in the range from 10 to 10 ^, and being the homogeneous sprayable mixture has a relative solution viscosity (measured on a solution of 1 g of the mixture in 100 ml m-cresol at 25 ° C in an Ubbelohde viscometer) of at least 2.0. Le A 12 156 -6- 009843/1938 2. Homogeneous sprayable mixture according to claim 1, characterized characterized in that the polyamide polycaprolactam and the polyolefin containing hydroxyl groups are a saponified copolymer is made up of ethylene and vinyl acetate. 3. Process for the production of homogeneous injectable mixtures of polyamides and polyolefins, characterized in that that the polyamide-forming starting materials before the polycondensation or the polyamides during or after a hydroxyl-containing polyolefin is added to the polycondensation. 4. The method according to claim 3, characterized in that polyamide-forming monomers in the presence of a hydroxylgruppenhaltig en polyolefin "polycondensed at temperatures of 100-300 ⁰ C. 5. The method according to claim 4, characterized in that there is used as the polyamide-forming monomer caprolactam. 6. The method according to claim 3, characterized in that the hydroxyl-containing polyolefin is a polyolefin which 60 - 90 wt. $ from recurring units of the general formula R, C4- and to 10 formula - 40 wt. 3 4 | from recurring units of the -Ic OHi c-4- consists in which R ₁ , R ₂ , R ₅ and R. are identical or different Le A 12 156 —V— 009843/1938 can be and represent hydrogen, a lower alkyl group or halogen. 7. The method according to claim 3, characterized in that the polyamide is mixed with the polyolefin containing hydroxyl groups and then extruded. 8. The method according to claim 6, characterized in that polycaprolactam is used as the polyamide. Le A 12 156 -8- 009843/1938