DE1939758B2 - Polyamide-based hot melt adhesive - Google Patents

Description

A. 10-40 mol% aliphatic, open chain and / or cyclic dicarboxylic acids with 4-12 carbon atoms and aliphatic open-chain and / or cyclic diamines having 2-15 carbon atoms, at least half of which of the diamine radicals at least three carbon atoms of the main chain or of the ring contains bonded alkyl groups

B. 10-40 mol% ε-aminocaproic acid

C 25-80 mol% -aminocarboxylic acids with 7-12 carbon atoms and possibly

D. small amounts of aromatic dicarboxylic acids or diamines.

2. Use of copolyamides according to claim 1, characterized in that as open-chain diamines with at least three bonded to carbon atoms of the main chain Alkyl groups 2,4,4-trimethylhexamethylenediamine and / or 2,2,4-trimethylhecamethylenediamine as corresponding cyclic diamine 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (Isophoronediamine) is used

3. Use of copolyamides according to Claims 1 and 2, characterized in that one the open-chain and cyclic diamines with three carbon atoms of the main chain or des Ring-bonded alkyl groups in a molar ratio of 80:20 to 20:80

Chain diamines reduce the melting point, but also the hot water resistance

Finally, those copolyamides became known as hot melt adhesives, which are polymeric as acid components Contain fatty acids (Skeist, Handbock of Adhesives 1962, ρ 425-433), also these copolyamides In addition to their poor resistance to chemical cleaning, they do not show sufficient resistance to hot water, d. H. they are not sufficiently resistant to ίο hot detergents.

Copolyamides based on long-chain amino acids,

e.g. aminoundecanoic acid or laurolactam Although hot melt adhesives are suitable for heat sealing textiles, they are not sufficient

ι 5 wash resistance, d. H. Hot water resistance

The object of the invention is therefore the disadvantages of State of the art to overcome and hot melt adhesive

provide which are both good hot water resistant as well as being resistant to dry cleaning.

Of course, the melting temperatures should be below 160 ^0C.

The problem is solved if copolyamides based on dicarboxylic acids, Diamines and ω-aminocarboxylic acids used which

A. 10-40 mol% of residues of aliphatic, open-chain and / or cyclic dicarboxylic acids with 4-12

so carbon atoms and their equivalent residues of aliphatic and / or cyclic diamines with 2-15 carbon atoms, with at least half of the diamine residues at least three bonded to carbon atoms of the main chain or the ring

J5 contain alkyl groups, B. 10-40 mol% residues of ε-aminocaproic acid

C. 25-80 mol ¹ j residues of ω-aminocarboxylic acids having 7 - which contain 12 carbon atoms.

From US-PS 22 52 555 it is known that copolyamides of at least one diamine with at least one hydrogen atom on the nitrogen atoms, at least ⁴ ^ one hydrogen atom on the nitrogen atoms, at least one dicarboxylic acid and at least one monoaminocarboxylic acid can also be used as hot melt adhesives. Example 1 of this patent describes a binary copolyamide of e-amino ^w caproic acid and the salt of 2,5-dimethylhexamethylenediamine and ot / t'-dimethyladipic acid. This copolyamide has a low melting point; however, this feature alone is not sufficient for processing textiles. This copolyamide has indeed "a low melting point; fehlf this feature is however not in itself sufficient for the processing of textiles This copolyamide is not cleanable, because it is soluble in halocarbons Finally, this copolyamide is it **> heißwasserbesländig and also a.. Longer-chain lactam. Caprolactam alone in connection with polyamide-forming components from dicarboxylic acids and diamines are not sufficiently hot water resistant. The low melting point is a necessary but not sufficient feature, since the conditions of hot water resistance and resistance to cleaning must also be met Open-chain and cyclic, branched or unbranched aliphatic dicarboxylic acids with 4 to 12 carbon atoms can be contained in the hot melt adhesive according to the invention, for example: succinic acid, adipic acid, 2,2,4-trimethyladipic acid, azelaic acid, dodecanedioic acid, C. cyclohexane-1,4-dicarboxylic acid.

The following suitable diamines may be mentioned, for example: up to 50 mol% of the diamine content open-chain or cyclic aliphatic unbranched diamines with 2 to 12 carbon atoms, for example hexamethylene diamine, dodecamethylene diamine and up to 00 to 100 mol% of the branched diamines, such as 2.4 , 4- and 2,2,4-trimethylhexamethylenediamine, I -aminoO-aminomethyl-S ^ .S-trimethylcyclohexane.

Ω-Aminocarboxylic acids are also understood to mean their lactams. For example: ω-aminocaproic acid (caprolactam), ω-aminoundecanoic acid, ω-aminolauric acid (laurolactam).

By adding small amounts of aromatic dicarboxylic acids or diamines, the melting temperature can be increased if necessary.

The middle molecular weights of the polyamides used as hot melt adhesives according to the invention are between 2000 and 40,000. The most suitable polyamides for textile bonding have average molecular weights between 6,000 and 25,000.

The copolyamides used can very easily by known processes, / .. B. by melt condensation, getting produced. The molecular weights are in

known way by using a diamine or Dicarboxylic acid excess or by adding monofunctional ones Amines or carboxylic acids adjusted during the condensation

The specification of the mol percent relates to the CONH groups, & h. the sum of 0.5 mol of dicarboxylic acid residues and 0.5 mol of residual diamine is treated as 1 mol

The melting temperatures were determined with a hot stage microscope at the temperatures indicated the samples begin to stick to the base.

example 1
A copolyamide from

1.06 mol adipic acid

0.60 mol l-amino-3-aminomethyl-3,5,5-t: rimethyl-

cyclohexane

0.20 moles of dodecamethylene diamine

0.20 moles of 2,4,4-trimethylhexamethylene diamine

2.00 mol caprolactam

4.00 mol ω-aminoundecanoic acid

is prepared by melt condensation at 200-230 ⁰ C The average molecular weight is 17 000th

The melting temperature betrögt 140 ° C, the max, water absorption 8%, the copolymer is dissolved in ethanol and sprayed onto a web of pulp fiber After brief pressing at 130 ⁰ C s is obtained a solid non-woven fabric when washed with wash liquor of 80 "C retains its strength

Example 2
A copolyamide from

0.70 moles of adipic acid

030 moles of azelaic acid

1.08 mol l-amino-S-aminomethyl-S.S.S-trimethyl-

cyclohexane
1.00 mol caprolactam

5.00 moles of ω-aminoundecanoic acid

is prepared by melt condensation at 200-230 ⁰ C The average molecular weight was 54 000. The melt temperature is 150 ⁰ C, the max.

μ water absorption 12%. For this polyamide staple fibers were produced and this was in an amount by weight of 5% is added in the production of a nonwoven web of nylon 6,6 by pressing at 120 ⁰ C the fleece is solidified when washing in the wash liquor of 100 ° C no strength loss was observed

Claims (1)

Patent claims: 1. Use of copolyamides based on of dicarboxylic acids, diamines and α-amino carboxylic acids as a hot-melt adhesive, characterized in that copolyamides are used as the hot-water-resistant hot-water adhesive