DE2022208A1 - Improved High Frequency Weldable Foams and Methods for Making Them - Google Patents

Description

PATENT LAWYERS

hVOU KKEiSiER DR.-ING. SCHCf NWALD; DR.-ING. TH. MEYER BR. FPES DiPL-CKEM, ALE K VON KREISLER DIPL-CHEM. CAROLA KELLER DR.-ING. KL0PSCK

COLOGNE i “EtEiCHMAWNKAUS

April 28, 1970 Fu / bz

Company Rudolph Koepp & Co-> Chemical factory ÄS, 6227 Qestrlch / Rheingau

Improved high frequency weldable foams and d

"Process for their production "

Foams made from synthetic polymers and in particular flexible or elastic foams of this type are used today in technology ir., large scale, for example used as cushioning material or for the production of insulation. Polyurethane foams are of particular importance here obtained, which can be based on polyester and / or polyether »There are such foams with a largely closed cell structure known as open-pore foams. Polyurethane foams commonly used today are, for example described in "Kunststoff-Handbuch", Volume VII, Polyurethane, Production, properties and use, Carl-Hanser-Verlag, Munich, 1966, pages 25 to 28 and pages% 42 to 447. Further information on polyurethane foams can be found in "'Ullmanns- Encyklopädie der technical chemistry ",>. edition, volume 14, pages 352 bis (Urban & Schwarzenberg, Munich-Berlin, 1965).

For the processing of foams and especially polyurethane foams, their weldability; of great practical importance. In particular, high-frequency welding is important in practice today, »

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Many foams, and in particular polyurethane foams, show unsatisfactory behavior when they are welded and especially with HF welding. It has therefore been proposed to improve weldability and in particular the HP weldability of polyurethane foams, thermoplastic resins in the Incorporate foams. Among other things, the incorporation of polyvinyl chloride, polyvinylidene chloride, Polyvinyl acetate, polyamide or the use of mixtures of such thermoplastics, in particular the use of mixtures of polyamides and polyvinyl chloride. The addition of the thermoplastic resins can either be done during the production of the foam - for example by mixing the thermo. plastic resin with a reaction component of the polyurethane foam before foaming (see for example the German patent specification 1 08l 220) or but also by subsequent impregnation of the finished polyurethane foam with the thermoplastic Resins. Impregnation of the foam with solutions, plastisols or dispersions of the Thermoplastics take place (see, for example, the German patents 1 08l 220 and 1 292 4o6 and the DAS 1 245 117).

The previously proposed thermoplastic resins or resin mixtures, however, have in the processing of the thus modified foam has a number of disadvantages. On the one hand, these make themselves in particular noticeable in difficult welding problems, for example wisely with HP welds with textile structures, on the other hand problems can be caused by insufficient thermal stability! did the thermoplastic resins arise. So are polyvinyl chloride, polyvinylidene chloride and polyvinyl acetate only insufficiently resistant at higher temperatures. Are these resins used in the manufacture of the

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Polyurethane foam with foam, this is how it works inadequate heat resistance already disadvantageous -during of manufacture. The class of thermoplastic resins mentioned can be differentiated by the exothermic Reaction of the polyurethane components results in temperatures that are up to 180 ° C and above hold for several hours, partially decompose. This causes the foam block, especially in the core area discolored and the sweatiness of the foam decreases.

In the case of HF welding itself / and especially in the case of difficult welding problems, such as ornament welds of textile-laminated foams or welding of foam with enclosed textiles or Cotton fleeces with loose electrodes occur when using such thermoplastic resins as a result of unavoidable local Overheating within a larger electrode image repeatedly breakdowns caused by gas formation on the incorporated thermoplastic particles caused by thermal decomposition.

Another disadvantage can be that polyurethane foams finished with such thermally unstable resins not or only badly after the flame lamination process can be connected to textiles. It finally adds that by the inevitable Acid development in the flue gases the entire laminating system is at risk of corrosion. the These disadvantages naturally also apply to mixtures of, for example, polyvinyl chloride with other thermoplastics Auxiliaries, such as polyamides, as well as for mixtures of polyvinyl chloride or other acidic thermoplastic resins with plasticizers.

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Other thermoplastic welding aids that do not form acidic components when subjected to thermal stress, for example polyethylene or polystyrene, are for; most important welding processes, HF welding, not very suitable because they do not have a sufficient loss factor to avoid the poor welding properties to improve pure polyurethane foams. They are therefore particularly useful for improving the ability to weld with HF Unsuitable for polyurethane foams. At best they can serve to improve the plastic behavior to improve the foam when exposed to external temperatures.

Polyamides have a special position. They do not show the disadvantages outlined and are also sufficiently stable at the temperatures which occur during the production and welding of polyurethane foams equipped with them. In particular, it has surprisingly been found - and this is an important element for the present invention - that certain selected types of mixed polyamide are important as welding aids for foams, in particular polyurethane foams. While the melting points of the classic polyamides, for example of the polycaprolactam or 6,6-nylon type, are so high that a sensible use as welding aids for polyurethane foams is difficult, it has been shown that mixed polyamides, especially ternary mixed polyamides, with melting points or heat sealing points below , preferably provide about l80 C below about 10O ⁰ C, a marked improvement in welding characteristics of Polyurethanschäurnen. Such mixed polyamides with heat sealing points in the range from about 100 to ku ^(J 0 and preferably in the range from 120 to IMQ ⁰ C, are described several times (see, for example, the brochures from Bridi r.ohe Anilin- und Rod ;; factory,

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■; ■ ... _ 5 -

Ludwigshafen, M 20? 4d - 8ϋ4ΐΛ (620) April 1965 "Ultramid 1 C "and preliminary work instructions" Kuroplast KR 2235 "11.66 as well as the information sheet from Dr. Plate" GmbH, Chemical Factory, Bonn "Platamid H I05 P" 9.67).

In this context, the so-called polyamide resins have also proven to be the fourth full welding aid for the invention proven, which can be obtained by condensation of ethylenediamine or Polyathylenaininen with branched polycarboxylic acids, in particular, dicarboxylic acids are obtained, which in turn are obtained by dimerization of unsaturated fatty acids can be obtained. In practice, these are polyamide resins with melting points depending on the composition of the resins known in the range from about II5 to I85 C, with for the invention preferably finds polyamide resin types with heat seal points not above about 160 ° C. For the production and properties of such polyarnide resins see, for example, "Ulltnanns Encyklopadie der technischen Chemie", Volume 14, a. a. 0., pages 73 up to 75 as well as "Kunststoff - Handbuch" a. a. 0., Volume VI, Polyamides, page 387

In the context of the work according to the invention, however, it was also found that the sole use of these comparatively low-melting copolyamides or polyamide resins can still entail certain difficulties. The loss factor of the polyamides, which is of great importance for HF weldability, is to a large extent dependent on temperature and humidity. The loss factor of dry polyamides is only about 0.02 at a temperature of about 0.02, but already rises to over 0.2 at 90 C, ie to more than 10 times the value. In the case of HB ⁿ welding, preheated electrodes must therefore be used when only these types of polyamide are used, which is only possible in special cases.

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or it must be welded with very high field strengths, which increases the risk of breakdown considerably.

Surprisingly, it has now continued to be within the scope of the invention demonstrated that a group of synthetic polymers can be used as welding aids and in particular is particularly suitable as an aid for HF welding, which has not previously been used for this purpose. These welding aids according to the invention are polyvinyl alcohol and / or the acetals of polyvinyl alcohol. In particular, polyvinyl acetate and their mixtures with polyvinyl alcohol are the preferred welding aids in the context of the invention.

Polyvinyl alcohol and polyvinyl acetate are known and used Synthetic material classes used to a considerable extent in practice, but not as welding aids. They are described in detail, for example, in "Ulimanns Encyklopadie der technischen Chemie", 5th edition, volume 14, pages 2j56 to 248 (Urban & Schwarzenberg, Munich-Berlin, 1963). It has shown, that they are able to produce foams and in particular polyurethane foams an unexpectedly good ability to weld to rent. They are characterized in particular by a combination of advantageous properties. she show a favorable loss factor even at 20 C, so that high-frequency welding warms up quickly the seam areas is guaranteed without excessive tension requirements. In addition, these compounds exhibit have a very high long-term heat resistance and also split when heated - for example in a flame lamination system - no harmful acids. The invention accordingly relates to foams and in particular polyurethane foam with improved properties for welding, preferably for HF welding, which is due to a content

1 0 9 8 A _9/1 A 9 1 nA n

marked on polyvinyl alcohol and / or polyvinyl acetal.

It is particularly advantageous that these welding aids the invention already incorporated into the foam as part of the foam production can be, as well as by subsequent impregnation in the already pre-formed .foam

are to be incorporated. In the production of polyurethane foams welding aids that are also used become "at least one of the starting components for the polyurethane formation, usually the hydroxy component, is added prior to the polyurethane formation reaction. For the subsequent impregnation of a pre-formed foam with flowable preparations of the welding aid, it may be preferred to have one Use sufficient open-cell foam so that the impregnating agent is not only applied to the outer surface of the foam adheres. But it is also possible that To apply welding aids only superficially to a previously finished foam, which then can also have a closed cell structure. This application can, for. B. by sprinkling, or printing and, if necessary, subsequent sintering, this method of operation can then be of particular importance Be important when comparatively thin foam layers together with quantitatively significant thermoplastic coatings are to be used, for example as a supplement that facilitates the HF welding. During the incorporation of the welding aid already in. Within the scope of foam production, it is possible to evenly interspersed with the welding aid To create foams, regardless of whether they are open-cell or closed-cell: Foam type is involved.

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If the introduction of polyvinyl alcohol and / or polyvinyl acetate in polyurethane foams leads to a significant improvement in the weldability of the foam, then, according to a further feature of the invention, the effect of the polyvinyl alcohol and / or polyvinyl acetal is combined with the effect of other welding aids. Welding aids, which up to now could not be used in HF welding or only with certain difficulties, show a completely different behavior when they are used in a mixture with polyvinyl alcohol and / or polyvinyl acetate. In particular is the ^ß brnischung with the inventive welding aids important pale those thermoplastic resins which are thermally stable in itself entirely or eliminate any acidic components upon heating, the loss angle is however so unfavorable that so far in the HP-welding their use difficulties with brought himself. The admixture of even small amounts of polyvinyl alcohol and in particular polyvinyl acetal or its mixtures with polyvinyl alcohol leads to a greatly improved likelihood of HF welding even on the cold electrode, with a synergistic increase in effectiveness generally being observed. The use of polyvinyl acetal or polyvinyl alcohol is to a certain extent comparable to preheating the welding electrodes. According to the invention, with such mixtures of welding aids, visual defects are achieved which, in the absence of polyvinyl alcohol or acetal, cannot be adjusted or can only be adjusted under the most careful conditions, in particular with preheated electrodes. In this embodiment of the new technical teaching, a further object of the invention is a foam, in particular polyurethane foam, the weldability of which is thereby verbose: · -. is that a mixture of polyvinyl alcohol and / or Po. ' ¹ , .- · vinylacctal mixed with another thermoplr>. ~ "1.0984 9 / U91

■■■:. ■■■■■ ^: ■■■■■ - 9 - ν '■, ■ ^{; ::}

synthetic resin is provided as a welding aid. This further thermoplastic synthetic resin is preferably a thermally stable material, in particular No acidic components are split off under thermal stress. Here, for example, come into consideration Polyhydrocarbons, but above all the polyamides.

It has been shown that just the previously mentioned Mixed polyamides or polyamide resins with hot-seal points up to a maximum of 180.degree. C., preferably up to about 160.degree. C., excellent Mixing components for mixing with the polyvinyl alcohol and / or the polyvinyl acetal are. In this combination it becomes possible to use the favorable dielectric properties of the polyvinyl acetate and / or alcohols with the extremely favorable adhesive strength of these polyamide classes. By the favorable dielectric behavior of polyvinyl acetate or polyvinyl alcohols, rapid heating of the seam area is initiated, until the loss factor of the polyamide component is also the same at an increased temperature becomes high that this part is active in the HP welding Has. In addition, such combinations of welding aids evidently use the sintering or Lower the melting point of the polyurethane foam. Polyurethane foams equipped in this way can be used Composite bodies - for example with appropriately equipped textiles or plastic films - by welding produce that have excellent adhesion.

In the context of the invention it is possible to adhere of the foam to other materials by adding rosin esters or rubber derivatives to increase, as they are known in particular as adhesion promoters in paint technology. Particularly useful -

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even if by no means necessary - it can be the case that a: .-: Mixture of the polyvinyl acetal or alcohol and the mixed polyamide or polyamide resin. This The mixture of substances can then either be incorporated into the foam during production, or it is a suitable preparation, in particular a solution, a dispersion or a plastisol incorporated into the previously prepared foam or placed on its surface and the liquid solution or dispersant is then removed.

Even limited amounts of the polyvinyl acetal and / or polyvinyl alcohol or the invention and containing this compound mixtures give good results with respect to the Schweißfreudigkeit, For example, with about J5 to ^ O wt -.% Of the thermoplastic welding aid in accordance with the invention, a sufficient in many cases willingness set for HP welding and subsequent adhesion in composite materials. However, considerably larger amounts of the welding aid can also be used, even when it is incorporated into the foam during its production. This is possible in particular if the welding aid is added in sufficiently large grains during foaming. These do not then completely dissolve, but are built into the foam structure in grain form. The foam make up% - typically the welding tool can simulate up to about 00 wt.. About 10 percent J50 -.% Are preferred. These details relate in each case to the weight of the finished foam provided with welding aids.

Used as a welding aid in the manufacture of polyurethane foam incorporated, quantities of

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ORIGINAL

5 to 40% by weight of the welding aid, based on the polyol component of the polyurethane / particularly useful be. Even with subsequent impregnation an.s. prefabricated foam with a solution, a dispersion or a plastisol of the writing aid bzv. '. Mixture of thermoplastic resins within the meaning of Findings have been good results with corresponding Amounts of welding aid received. However, depending on the intended use, it can also do a lot here more of the welding aid is applied to the foam .v / ground. For example, the amount of welding aid can be up to 150% by weight, based on the foam gex \ 'ieht, can be increased. This can be meaningful when using thin foam sheets as inserts can be used for HF welding.

Commercially available polyvinyl acetate are generally compounds whose vinyl alcohol groups are predominantly, but not 100 %, acetalized. Sole polyvinyl acetate can be particularly useful as a Zehweißhilfsmittel, in particular also in disregard ■ misehung with the described class of mixed polyamides bzxtf. Polyamide resins are used. Polyvinyl acetals with a content of about to 98 fo, preferably 80 to 38 fo, acetal groups are particularly preferred.

Are in the preferred embodiment of the invention Mixtures of such polyvinyl alcohols are used with the polyamides or polyamide resins of the maximum melting or sealing point of about 160 ° C., any mixtures between Polyamide component and polyvinyl alcohol or acetal component are used. Surprising nerve but only limited notes are sufficient, for example less than 50 wt .-> i of the them · ^ plastic Make up the overall mix in order to

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wanted to ensure rapid and even heating of the weld seam. Already amounts up to about 1/4 of the total mixture of thermoplastic welding aids used can be sufficient. Will additional adhesion promoters, i.e. those from paint technology: known resin esters, or rubber derivatives, are also used, so these can be up to about 25 wt .- ^, based to the total amount of thermoplastic welding aids. The use of the Polyamides or polyamide resins will always be advantageous if particularly good values with regard to the Adhesion strength of the weld seam are required. However, if you want, for example, only sharply profiled seam patterns, such as upholstery pipes or decorative seams on composite materials made of foam and, for example, textiles by HP welding, in which the bond has already been achieved by other measures, such as gluing or Flame lamination is ensured, so you can add polyamide and / or other adhesives Do without materials in whole or in part. Of particular importance is that in all Cases at temperatures not exceeding 170 C. excellent welding results can be obtained. That's just for polyurethane welding of vital importance. Higher temperatures easily lead to thermal decomposition and degradation of the polyurethane foam, while no disadvantageous properties up to this temperature limit are to be expected from the welding process on the polyurethane structure.

The production of the polyurethane foams provided with welding aids for the purposes of the invention, the falls within the scope of the invention, takes place according to the methods known per se of polyurethane foam

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production, as indicated, for example, in the cited literature.

The foams and / or the thermoplastic welding aids can be used in a manner known per se Additives for a wide variety of purposes, for example dyes, flame retardants, Contain plasticizers and the like.

The following examples to illustrate the invention are divided into three sections A, B and C. In the example part A gives the basic recipes for typical polyurethane foams used today. Example A, 1 depicts an ester foam, example A, 2 an ether foam and example A, j5 a self-extinguishing ether foam.

With the help of these three basic recipes, the Comparative tests carried out in Sections B and C.

Part B describes the results obtained with Welding of polyurethane foams can be obtained, which the welding aid in the context of foam production has been added. In all cases, the respective welding aid was the polyester added before the addition of the polyisocyanate.

Section C of the process examples summarizes the results which were obtained when the finished polyurethane foam materials were subsequently impregnated with the welding aids. Here, therefore, polyurethane foams are first produced according to the basic recipes in Section A and then in the procedure in Section; C described manner was subsequently impregnated with the swing Lßhi 1 · -nitteln.

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Part A

Basic recipes for the production of the polyurethane foams.

j.) Polyester polyurethane foam:

100 parts by weight of a branched polyester

Adipic acid, diethylene glycol and triol with a hydroxyl number about 6o with

4.4% by weight of water

1.5 wt. "Dimethylbenzylamine and

1.2% by weight silicone stabilizer stirred.

In the tests explained in Part B, the respective welding auxiliaries are uniformly mixed into this mixture stirred in. This step is not necessary for the experiments in part C. In the mixture prepared in this way give a mixture of

35 parts by weight of tolylene diisocyanate with a content

of 8o % 2.4 and 20 % 2.6 isomers as well

18% by weight of tolylene diisocyanate with a content of 65 % 2.4 and 35 % 2.6 isomers

and mixes intensively with a high-speed agitator. The mixture yields, after 60 to 90 seconds Rise time an open-cell flexible foam having a density of about JO g / l, optionally (Part B) containing the welding aid in suspension..

2.) Polyether polyurethane foam:

100 parts by weight of a branched, with ethylene oxide

modified propylene glycol with a hydroxyl number approx. 49 are with

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4.5 parts by weight of water

0.7% by weight silicone stabilizer

0.08 wt. "Dimethylamino-Äthläther u.

0.5% by weight of tin octoate stirred.

In this mixture are explained under part B. Try to stir in the welding aid evenly. Add to the mixture prepared in this way 55 parts by weight of tolylene diisocyanate with a content

of 80 % 2.4 and 20 % 2.6 isomers. and mixes intensely with a fast running one

Agitator. The mixture obtained after 60 - 90 seconds A

Rise time an open-cell flexible foam with a density of approx. 50 g / ltr., Which if necessary (Part B) contains the finest distribution of welding aids.

5.) polyether polyurethane foam (self-extinguishing);

100 parts by weight of a branched polypropylene glycol

with a hydroxyl number approx. 56 are with

water

Triethylene diamine

Silicone stabilizer M

Triethanolamine and dibromopropyl phosphate Monofluorotrichloromethane stirred.

In this mixture are explained in part B. Try to stir in the welding aid evenly. Enter the mixture prepared in this way Mixture of

2.5 Weight II 0.5 Weight H 0.8 Weight H 6.0 Weight, - 11 10, OWeight 11 5.0 Gev; .- 1!

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JJ parts by weight of toluylene diisocyanate with 65 % 2.4 and

55 % of 2.6 isomers and 10% by weight of diphenylmethane diisocyanate

and mixes intensively with a high-speed agitator. After a Stone Age of 60 - ); 0 seconds, the mixture results in an open-cell flexible foam with a tree volume of approx. 45 g / l, which optionally (Part B) contains the finest distribution of the welding aids.

Welding aids incorporated into the foam during its production.

'' To carry out the experiment:

In each case 15 mm thick samples of a polyurethane foam were used Subjected to various welding tests using the welding aids given below contained. The following vision tests were carried out:

Case I.) HF welding with a 0.4 mm thick Soft PVC film.

Case II.) HF welding, 3sung with a 1 mm thick Nylon velor.

F & ll IIL) HL ^? ~ Welding between a 0.4 »".: I strong V / calibration PVC film and one with 3 -. '. Vg FcIy--

2
vinylicenchlorio / m 'coated ϊ · .. · u; -3 Lc-fjcT-

Paper.

The 3chv.'ei'3un, - _; ; (: ii v / urden ciUiT-hr, ^ r "kri ir.lt elr ^ cr} -: ic!: l> ■ de / on 550 nvr. 'KIacViο Ubci-'. 3ekunc ^ ni: ilt ciirot ' i '.y · now. ¹ 7' ti ''-I'7 Λΐι < ^! a »· i '..- tromi; t:.> !: vi of 0.4 A". ^y : ->

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BATH ORIGINAL

at a frequency of 27.12 MHz. The seam temperature

was held in all cases below 17O ⁰ C.

The subjective impression of the resulting weld seam was assessed and is classified in the attached tables as follows:

0 = no seam formation

1 - Point-by-point indication of a seam ■

2 = Seam in the manner of compressed foam 3 '= welded, translucent seam

The seam strength was determined by tearing it off transversely to the seam according to DIN 53.357 in p / cm seam length one hour de after welding has taken place.

The percentage of welding aid is in Yes by weight, based on the amount of polyol.

The following welding aids were used:

Polyvinyl alcohol: with a degree of hydrolysis 97-99 mol- # Polyvinyl acetate with a grade of 75 ~ 77 f> Acetal,

1 % acetate and 18-21 % alcohol form copolyamide by polymerizing a mixture of laurolactam, caprolactam and other polyamides

Polyamide A polyamide B:

Cyclo rubber:

Ingredients dimerized with a melting point of about 12O ° C Kondensationsprodukt.aus fatty acids with ethylene diamine having a softening point of 110-120 ⁰ C Cyclized isoprene.

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Table 1

Polyester foams according to Al.)

Welding aids

seam

Without

10 % polyvinyl alcohol

10 % polyvinyl acetal

20 % polyamide A

20 % polyamide A + 5 % polyvinyl acetal

10 % polyamide A + 5 % polyvinyl

acetal + O% cyclo rubber

A.)
liability

B.)
liability

420 ρ 610 ρ

840 ρ 950 ρ

1200 ρ 1500 ρ

480 ρ

1900 ρ

200 ρ
1900 ρ

over 2000 p,

not measurable
the foam
rips

over 2000 p,
not measurable
the foam
rips

C) liability

500 ρ 380 ρ

500 ρ 000 ρ

600 ρ

Table 2

Polyether foam according to A 2.)

Welding aids

seam

A.) Liability

B.)
liability

C,)
liability

Without

10 % polyvinyl alcohol

10 % polyvinyl acetal

20 % polyamide A 20 % polyamide B

20 % polyamide A + 5 % polyvinyl acetate

20 % polyamide B + 5 % polyvinyl acetal

20 % polyethylene

20 % polyethylene + 5 % polyvinyl acetal

O / 0 1 l6op 1 1 200 ρ i 2 520 ρ 2 2 300 ρ 2 3 Demolition in
the seam
over 500 ρ 3 3 Demolition in
the seam
over 500 ρ 3 O / 0

ρ

ρ
ρ
ρ

ρ
ρ

Ιβθ ρ ρ

80 ρ 360 ρ

240 ρ 400 ρ 280 ρ

570 ρ

350 ρ 160 ρ

300 ρ

NJ NJ CD OO

Table 3
^ Siiäkherschau ^ according to ^ A ^

Welding aids

Without 10 %

10

Polyvinyl alcohol

Polyvinyl acetal

20 % polyamide A

20 % polyamide + 5 % polyvinyl acetal

Seam A.) Seam B.)

Liability liability

O O

2 3

120 ρ 350 ρ

550 ρ

C)

liability

200 ρ 560 ρ

250 ρ 500 ρ

■ 500 ρ

Part C.

Subsequent impregnation of the without incorporation
foams made from welding aids
according to part AV- -. .

1. V A polyurethane foam, which was produced according to the basic formulation A 1, is impregnated with 50% of its weight of the following solution:

20 parts by weight of a copolyamide from laurolactam,

Caprolactam and other polyamide "

constituents (melting point about 120 ⁰ C) "

10% by weight Po.lyviny! Acetal 2p% by weight of "carbamic acid ester 70, 0% by weight" ethanol 20, 0% by weight "benzene 10, OGew.- "water

The foam impregnated in this way is dried at 105.degree. The product obtained is excellent. High frequency weldable.

2.) A polyurethane ether foam produced according to Basic formulation A 2 is impregnated with the same amount by weight of the following dispersion:

10 parts by weight of a mixed polyamide on the basis

of caprolactam, hexamethylenediamine /
Adipic acid and ρ, ρ-diaminodicyclohexylmethane / adipic acid (melting point about 185 ° c)

5.0% by weight polyvinyl acetal

2.0% by weight "carbaraic acid ester

2.0% by weight benzenesulfonic acid N-butylamide 50, owt- "butanol

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dispersed in

40.0 parts by weight of water 10.0% by weight of vinylpyrrolidone

This dispersion is distributed evenly by squeezing in the foam and thus finished foam at 105 C dried. An excellent HF-weldable product is obtained.

100 parts by weight of a condensation product

dimerized fatty acids with ethylene diamine (softening temperature 110-12Ot)

25 wt. "Polyvinyl acetal with a content of

75-77 % acetal, 1 % acetate and 18-21 % alcohol

10% by weight of cyclized isoprene rubber

are merged with each other. After solidification, the melt is ground to a grain size of; 500 / rev.

A polyester-polyurethane foam, produced according to basic formulation A 1, is cut into a 1 mm thick film and this film is sprinkled with the above-described milled melt using a suitable scattering device with 150% of its own weight. The foam sheet coated in this way is heated so high under an infrared field that the grains of the melt sinter and adhere to the foam surface.

The point-coated foam film produced in this way is used as a supplement for HF welds in particular for HF welding of textiles.

109849 / U91

Claims (1)

Claims 1) Foams, especially polyurethane foams, with improved HF weldability and a content of thermoplastic resins as welding auxiliaries, characterized in that the thermoplastic welding aid is polyvinyl alcohol and / or polyvinyl acetate, optionally mixed with other thermoplastics that promote weldability, are present. 2) foams according to claim 1, characterized in that that polyvinyl alcohol and / or polyvinyl acetal in a mixture with polyamides, preferably with polyamides a melting or heat sealing point below 180 ° G. - 5) foams according to claims 1 and 2, characterized in that the polyamides mixed polyamides with a melting or heat seal point up to about 160 ⁰ C, preferably in the range of about 120 to 140 C, or polyamide resins made from ethylenediamine or polyethylene amines with higher branched dicarboxylic acids are. 4) foams according to claims 1 to j5 *, characterized in that they contain mixtures of polyvinyl acetal and polyvinyl alcohol and in particular polyvinyl acetals with a content of about 70 to 98%, preferably 80 to 88 % acetal groups. 5) foams according to claims 1 to 4, characterized in that they are polyvinyl acetal and / or polyvinyl alcohol together with other thermoplastic raw white auxiliaries, in which Mixtures of polyvinyl acetal and / or polyvinyl alcohol at most 50% by weight, preferably at most about 1098A9 / U91 .% Of the total make up thermoplastics mixture - 25 wt. 6) foams according to claims 1 to 5, characterized '■ * denotes that the welding aid addition Harzester or rubber derivatives, preferably in amounts up to about 25 wt -. Based on the total amount of the thermoplastic welding aid - - contains%. 7) foams according to claims 1 to 6, characterized in that the welding aid is incorporated into the polyurethane foam during its production and is preferably present in amounts of about 3 to 60 wt .-%, preferably about 10 to '$ 0 wt .-% is. 8) foams according to claims 1 to 6, characterized in that the thermoplastic welding aid is introduced by impregnation or surface coating of the preformed foam, and that it is in amounts of 5 to 150 wt. %, Preferably 2 <~> to 100 wt. -% - in each case based on the foam weight - is present. 9) Processes to improve the weldability, in particular the HP weldability of foams, preferably polyurethane foams, by incorporating thermoplastics into the foam during its production and / or by impregnating the finished foam with the thermoplastic, characterized in that the thermoplastics are polyvinyl alcohol and / or polyvinyl acetate optionally used as a mixture with other thermoplastic resins. 1098A9 / U91 10) Method according to claim 9 »characterized in that that you have polyvinyl alcohol and / or polyvinyl acetal together with polyamides, preferably one Mixed polyamides or polyamide resins with / melt or a heat seal point of up to about 160 ° C., preferably about 120 to 140 ° n. 11) Process according to Claims 9 and 10, characterized in that polyvinyl acetate is used with a content of about 70 to 98 %, preferably 80 to 88 %, acetal groups. 12) Process according to claims 9 to 11, characterized in that mixtures of thermoplastic welding aids are used which contain no more than about half, preferably no more than about 1/4 of the thermoplastic resin mixture of polyvinyl acetal and / or polyvinyl alcohol and which also contain additional as Harzester or rubber derivatives, preferably in amounts up to about 25 weight adhesion promoter, -% _s can, based on the total amount of the thermoplastic welding aid contained.. 13) Process according to Claims 9 to 12, characterized in that the thermoplastics are incorporated at least partially in the foam production in such a way that they are added to one and / or more starting components of the foam - in particular the polyol - and preferably about 5 to ^ O wt -.% of thermoplastic materials - based on the polyol - is admixed. 109849/1491 14) Process according to Claims 1 to 11, characterized in that the thermoplastics are incorporated or applied at least partially in the form of a solution or a plastisol or a dispersion in the finished foam in a manner known per se and preferably 5 to 150 wt. -%, in particular 10 to 100 wt -.% of the thermoplastic resin - based on the foam weight - bulk. 109849 / U91