DE1939758A1 - Polyamide-based hot melt adhesive - Google Patents

Description

Hotmelt adhesive _on__Pol2amid_-_ base 19.39758

The invention relates to the use of a copolyamide of certain composition as a hot melt adhesive.

It is generally expected of a hot melt adhesive that its properties, in particular the melting behavior and thus its thermal stability are not significantly changed by environmental influences will. If a hot melt adhesive contains hydrophilic groups, it will be stored in water or in a humid atmosphere Swollen with water. In the case of polyamides, the melting temperatures of which are below about 180 ° C, the water absorption leads to a strong reduction in heat resistance, so that the bonded parts under the action of water, especially hot water, disintegrate.

Polyamide-based hotmelt adhesives, which are supposed to be resistant to water, especially hot water, therefore have one as possible low content of CONH groups responsible for water absorption. They are made using Long-chain dicarboxylic acids, e.g. dimerized fatty acids or long-chain amino acids such as £ <-aminolauric acid or their lactam. The relatively low content of these polyamides in CONH groups allows high water absorption not to.

In many cases, however, the highest possible water absorption is desired. This applies, for example, to certain hot-melt adhesives, especially those that are to be used for bonding textiles and the. Should not impair the moisture balance between the skin and the surrounding air. This property is often important for maintaining breathability even for glued wooden parts. The discovery of such a polyamide-based adhesive was on the task which was of the present invention is based,

109804/202

Copolyamides with a high proportion of similar unver- i ν branched structural units are tellkristallin and have of melting temperatures well above 200 ^0C. Such high melting temperatures are generally undesirable for various reasons when used as hot-melt adhesives. With lower contents of the mentioned unbranched structural units of the same type, the melting temperature drops considerably. At the same time, however, the resistance to water, in particular to hot water, is reduced, so that in order to avoid this disadvantage it is necessary to use long-chain dicarboxylic acids, diamines and aminocarboxylic acids. Naturally, however, such polyamides have only a very low ability to absorb moisture.

It has now been found that certain polyamides on the branched As a hot-melt adhesive, diamines are based on the requirements for high water absorption and simultaneous resistance against hot water, even though their melting temperatures are below 160 ° C. Polyamides of this type are marked through a composition of the following components:

1.) lo-90 mol # residues of aliphatic, open-chain and / or cyclic dicarboxylic acids with 4-12 carbon atoms and these equivalent radicals of aliphatic open-chain and / or cyclic diamines with 2-15 carbon atoms, where at least half of the diamine radicals are branched, that is, bound to carbon atoms of the main chain or of the ring Contains alkyl groups.

2.) 9o-lo mol # of residues of <^ / - amine carboxylic acids with 4-12 carbon atoms *.

To obtain hot-melt adhesive having melting temperatures below 150 ⁰ C and with a resistance to wash liquors of ^8θ Θ, in the mentioned under 1. to the component for use fcom-

. . 109808/2021

With the copolyamides, at least half of the diamine residues are present at least 2 carbon atoms of the main chain or of the Ring bound alkyl groups contain. >

The melting temperature is even lower when open-chain diamines are combined with cyclic diamines. Surprisingly, the resistance to hot water is not impaired. Open-chain diamines with at least three carbon-bonded alkyl groups and cyclic diamines with at least three alkyl groups bonded to ring carbon atoms in proportion 1 have proven to be particularly ^{favorable. With these, melting temperatures below 150 °} C. and resistance to boiling wash liquor are achieved.

A moisture absorption capacity of 8 % - 12 % can be achieved with hot melt adhesives of the following composition:

1. lo-40 mol # of residues of dicarboxylic acids with 4-12 carbon atoms and these equivalent radicals of diamines having 2-15 carbon atoms, with at least half of the diamine radicals contain at least three alkyl groups bonded to carbon atoms of the main chain or of the ring.

2. lo-40 mol # residues of ζ / -aminocaproic acid

25-80 mol # of residues of β / -amino carboxylic acids with 7-12 carbon atoms. This hot melt adhesive can despite rel. high melting temperature at temperatures down to 110 ° C processed who because they have a wide softening range.

A particularly high water absorption capacity of up to approx. 15 % can be achieved with hot melt adhesives of the following composition:

1. lo-40 mol # of residues of dicarboxylic acids with 4-12 carbon atoms and these equivalent residues of diamines, where 20-80 % of the diamine residues are open-chain and at least half contain at least three alkyl groups bonded to carbon atoms of the main chain and 80 - 2o # of the diamine residues are alicyclic and at least half of them

10980-8 * 2-021 '

contain three alkyl groups attached to the ring. ^{:: ;;} · ■ · ■■ '■ 2. 90-60 mol $ residues of the' / ^ aminocaproic acid

These particularly interesting hot melt adhesives have melting temperatures down to HO ⁰ C and, despite their high water absorption, are resistant to washing liquor up to 80 ⁰ C, in the case of high aminocaproic acid residues of 85-70 mol, also resistant to boiling washing liquor. The residues of the following dicarboxylic acids can be contained in the hot melt adhesives according to the invention:

Open chain and cyclic, branched and unbranched aliphatic Dicarboxylic acids with 4-12 C atoms, e.g. succinic acid, adipic acid, 2,2,4-trimethyladipic acid, azelaic acid, Dodecanedioic acid, cyclohexane-lj ^ -dicarboxylic acid.

The residues of the following diamines can be contained in the hot melt adhesives according to the invention:

Up to 5o Mo1 $ of the diamine part are open-chain or cyclic aliphatic unbranched diamines with 2-12 C-atoms, e.g. Kthylenediamine, hexanebhylenediamine, dodecamethylene diamine, 50-100 Mol $ of the diamine part branched diamines with 3-15 C-atoms, eg 1,2- Propylenediamine, 3-methylhexamethylenediamine, ~ 5, 3-dimethylhexamethylenediamine, 2,4,4- and 2,2,4-trimethylhexamethylenediamine, J5 * 6-diamino ^ -methylcyclohexane, 1-amino-3-aminomethyl- ^ iSiS-trimethylcyclohexane, 4,4'-bisaminomethyl-2,2'-dimethyldicyclohexy methane.

The residues of the following C / -aminocarboxylic acids can be contained in the hot-melt adhesives according to the invention: C -aminocarboxylic acids with 4-12 carbon atoms, for example ^ -aminobutanoic acid, ^ - aminocaproic acid, ^ -aminoundecanoic acid, £ -aminolauric acid.

The addition of other polyamide formers to achieve certain properties is possible. For example, by adding small amounts of aromatic dicarboxylic acids or diamines increase the melting temperature if necessary.

The mean molecular weights of the invention as a hot melt adhesive The polyamides used are between 2000 and 40,000. The most suitable polyamides for textile bonding are mean molecular weights between 6,000 and 25,000.

The polyamides used according to the invention can be produced very easily by known processes, for example by melt condensation will. The molecular weights are determined in a known manner by using an excess of diamine or dicarboxylic acid or adjusted by adding monofunctional amines or carboxylic acids during the condensation.

The indication of the mol percent refers to the CONH groups, i.e. the sum of 0.5 moles of dicarboxylic acid residues and 0.5 moles Residual diamine is treated as 1 mole.

The melting temperatures were determined with the hot stage microscope. At the specified temperatures, the samples begin to stick to the surface.

example 1

A copolyamide from
1.05 moles of adipic acid

0.70 moles of 1-amino-1-aminomethyl- ^ iSiS-trimethylcyclohexane 0.30 moles of 2,2,4-trimethylhexamethylenediamine 6.00 moles of caprolactam

Is produced by melt condensation at 200-230 ^° C. The average molecular weight is about 000. The melting temperature is I5 bei'150 ⁰ C. The copolyamide accepts max. About 12 # V / ater on.

The product is comminuted in a blower mill to a grain size of 0.1 to 0.4 ram. To test for adhesion, the powder is sprinkled in a thin, even layer on pieces of canvas fabric 4 χ 10 cm in size, and covered with pieces of the same fabric of the same size

6 -

Iron at 130 ⁰ C, the two layers of fabric are glued. ° ·

After 1/2 hour of heating and stirring these test specimens in ^; '. Water of 95-10O ⁰ C, which contains 0.4 # of a household detergent ^: no reduction in adhesion is found. This is also 1/2 hour. Stirring in trichlorethylene at 60 ° C without affecting the adhesive strength.

Example 2

A copolyamide from

1.04 moles of azelaic acid

, 0.30 mole 1-4 bisaminomethylcyclohexane 0.30 moles of 2-methylhexamethylenediamine

0.4o moles of 3,3-dimethylhexamethylenediamine 5.20 moles of caprolactam

is produced by melt condensation at 200-230 C. The average molecular weight is 12,000. The melting temperature is 140 ° C., the water absorption 11 %. A 0.2 mm thick film made of this material is placed between 2 thin wooden plates, which are pressed in a steam-heated press with a pressure of 10 kg / cm. The glued wooden parts are stored in water at 60 ° C. for 10 hours. The bond does not come off.

Example ? .

By replacing ^ / 1,3-bisaminomethylcyclohexane in Example 2 by Hexamethylenediamine is given to a polyamide whose melting and processing temperature is 10 ° C higher. The heat resistance also increases by 10 ° C.

Example. 4th

A copolyamide from

1.08 moles of adipic acid

ο, βο Mol 2,4,4-l? ri®ethylhe3 £ amethylendiaß! to q.4o mol l-

BATH ORIGINAL

1.08808 / 2021

7.00 moles of caprolactam. ...-.

is obtained by melt condensation at 200 - 250 ⁰ C prepared. The mean molecular weight is _: 10,000. The melting temperature is 150 ° C, the maximum water absorption 12 %, The copolyamide can be used to bond lining materials in clothing. The glued parts do not come off in boiling detergent solution.

Example 5

A copolyamide from

1.06 moles of adipic acid

0.60 moles of 1-amino-5-aminomethyl-5,5i5-trimethylcyclohexane 0.2o moles of dodeca ^ methylenediamine

0.20 moles of 2,4,4-trimethylhexamethylene diamine

2.00 moles of caprolactam '

4.00 moles / 2 / aminoundecanoic acid

is obtained by melt condensation at 200 - 250 ⁰ C prepared. The mean molecular weight is 17000. The melting temperature is 140 ° C, the maximum water absorption 8 %. The copolymer is dissolved in ethanol and sprayed onto a cellulose fiber fleece. After brief pressing at 150 ^° C., a solid nonwoven fabric is obtained which retains its strength ^{when washed with washing liquor at 80 ° C.}

Example 6

A copolyamide from

0.70 moles of adipic acid

0.50 moles of azelaic acid

1.08 moles of 1-amino-5-aminomethyl-5i5i5-triniethylcyclohexane 1.00 moles of caprolactam

5.00 moles of Ca- aminoundecanoic acid

is obtained by melt condensation at 200 - 250 ⁰ C prepared. The average molecular weight is 14000. The melting temperature is 150 ⁰ C, the max. Water uptake # 12. Staple fibers were produced from this polyamide and these were added to a weight of 5% during the production of a fleece made of nylon 6.6 to. The web was consolidated by pressing at 120 ⁰ C. When washing in washing liquor at 100 ^° C., no loss of strength was observed.

'¥ 09808/2021

Claims (2)

P_a_t_e_n_t_a_n_s_g_r_ü_c_h_e 1. Claim Use of a copolyamide 1.IO-9O Mol # residues of aliphatic, open-chain and / or cyclic dicarboxylic acids with 4-12 carbon atoms and residues of aliphatic open-chain ones equivalent to these and / or cyclic diamines with 2-15 carbon atoms, at least half of the diamine radicals being branched, the means alkyl groups bonded to carbon atoms of the main chain or of the ring contains and 2. 90-10 mol # residues of £ -aminocarboxylic acids with 4-12 C atoms as hot melt adhesives 2. Claim Use according to claim 1, characterized in that in component 1 of the copolyamide used, at least half of the diamine residues contain at least 2 alkyl groups bonded to carbon atoms of the main chain of the ring. ^odur 3. Claim Use according to Claims 1 and 2, characterized in that in component 1 the copolyamide used at least half of the diamine residues have at least three alkyl groups bonded to carbon atoms of the main chain or of the ring contains. 4. Claim Use according to claims 1 - 3 * characterized in that that in component 1 of the copolyamide used, open-chain and cyclic diamine radicals in a molar ratio of 80: up to 20:80 are included. 5. Claim Use of a copolyamide according to claim 1 as a hot melt adhesive, characterized in that it is composed as follows: is: 109808/2021 1. 10 - 40 mol # residues of aliphatic, open-chain and / or cyclic dicarboxylic acids with 4-12 carbon atoms and residues of aliphatic open-chain ones equivalent to these and / or cyclic diamines with 2-15 carbon atoms, at least <half of the diamine radicals being branched, and 2. 10 - 40 mol # residues of £ -aminocarboxylic acid and 25 - 80 mol # of residues of ^ -aminocarboxylic acid with 7 - 12 carbon atoms 6. Claim Use of a copolyamide according to claims 1-5 as a hot melt adhesive, characterized by the following composition: 1. 10-40 mol # residues of aliphatic, open-chain and / or cyclic dicarboxylic acids with 4 to 12 carbon atoms and residues of aliphatic open-chain ones equivalent to these and / or cyclic diamines with 2-15 carbon atoms, at least half of the diamine radicals being branched, and 2. 90 - 60 MoIJi residues of the C -aminocarboxylic acid. 10900 «/ 2021