DE2438749A1 - Flat-shaped stiffener prodn. - by applying binder to support followed by sprinkling thermoplastic adhesive powder and heating - Google Patents

Abstract

Flat-shaped article provided with a thermoplastic or elastic binder and adhesive is produced by coating the article with an opt. synthetic binder applied by a standard process, e.g. as a solid or paste but pref. as an aq. dispersion; and forming the adhesive layer on this solvent-contg. and/or non-consolidated binder layer, by sprinkling or spreading a powdery thermoplastic having adhesive props. and subsequently heating to temps. above film-forming temp. The article is e.g. a stiffener esp. for shoes. Homogeneous, solidly anchored adhesive layers are obtd. High-melting, heat-sensitive adhesives may be used in solid form. Substrates, sensitive to high temps. or solvents, may be coated without damage.

Description

Gebr. Giulini GmbH

Lud.wigsh.afen / Rh. P _at

Process for adhesive powder coating containing solvents and / or unconsolidated fabrics

The present invention relates to an improved process for the production of thermoplastic material and adhesive-provided flat structures as well as .ein Device for its implementation,

Processes for the production of such flat structures are already known. A method is disclosed in OS 1 954-687 described in the woven, felt, nonwoven webs or knitted fabrics initially with an aqueous dispersion of a thermoplastic Impregnated and / or coated plastic and, after drying, with an adhesive layer consisting of a plastic dispersion, a solvent adhesive or a hot melt adhesive. The ones with thermoplastic Plastic-provided textile fabrics can be deformed when heated and are used for stiffening and maintaining the shape of shaped objects, in particular as cap materials for stiffening shoes or shoe parts. After cutting, they are exposed to heat and pressure, possibly also solvents the material to be stiffened ", for example leather, glued.

Although cap fabrics made in this way for gluing with Leather or other materials to be stiffened are well suited, the known manufacturing methods are still used not considered satisfactory in all respects. For example, a disadvantage is seen in that the adhesive is applied in a separate process step must become. This creates an additional work

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Gebr. Giulini GmbH Ludwigshafen / Rh.

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gear required. In addition, certain plastics show adhesive properties in this application process a low adhesive strength, so that if necessary the Application of adhesion promoter is required.

In order to eliminate the above disadvantages, the object was thus to provide a method for producing stiffening materials where the adhesive is used together with the stiffening material in one operation can be applied to the fabric.

The solution to the problem is that the flat structure in a known manner with a Binder is provided and that on this * layer the Adhesive layer by sprinkling on a powdered thermoplastic with adhesive properties and then Heating to temperatures above the film formation temperature is formed.

The binders used according to the invention can be of either synthetic or natural origin. Examples of binders of synthetic origin are thermoplastics such as polystyrene and polyethylene vinyl acetate; Centrifuged natural rubber latices can be used as binders of natural origin. You can use both in Form of aqueous dispersions or solutions in organic solvents, as well as solid or paste-like Form ^ Of course, the binders can also contain dyes, fillers, anti-aging agents, Propellants and others contain. However, aqueous dispersions of are preferred in the new process synthetic binders are used.

* Solvent-based and / or non-solidified

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Gebr. Giulini GmbH Lu.dwigsh.af en / Rh ..

For impregnation and / or coating of the fabric, The carrier of which can consist of both natural and synthetic fibers can be dispersions of styrene or styrene copolymers, ve * - such as styrene-butadiene or styrene-butadiene-acrylonitrile copolymers, which can optionally also contain an acrylate can be used. Polyvinyl ester, such as polyvinyl acetate, polyacrylates or polymethacrylates are also available in the form of their aqueous dispersions suitable. Dispersions of terpolymers, such as acrylonitrile-styrene-butadiene terpolymer, can also be applied will. Solutions or solids of the polymers just mentioned can also be used as binders.

The concentration of the dispersions can be within wide limits fluctuate, but is expediently between $ 4 and 65%. The quantities applied are also not critical,

you can z. B. 75-1000 g / m.

All powdery thermoplastics are used for powder application with adhesive properties in question. If the thermoplastics are only offered on the market in the form of granules, they must be ground before they can be used, expediently to a grain size of 0.1-500 μm. The amounts of powder applied are between 30 and 100 g

ρ · p

Fe st off / in, but in particular between 4-5 and 65 g / m. Particularly suitable thermoplastics for the purpose according to the invention are polyamide, polyester and polyvinyl acetate and their copolymers. The softening point of the thermoplastics' should be above 50 O ^0. An upper temperature limit for the softening point cannot be given, but it should be such that the subsequent heating results in a film formation without damaging the binding agent.

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Gebr. Giulini GmbH Ludwigshafen / Rh.

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by means of or the fabric comes.

For the simultaneous application of the aqueous binder dispersion, binder solution or binder with the Powdery adhesive can be the known units with impregnation, spreading or spreading units and Systems equipped with dryers are used. All that is required is the installation of an additional powder spreading head, via which the powder is applied to the not yet solidified binder layer.

The drying temperature in the oven should be above 90 C, advantageously between 110 and 150 ° C.

That the method according to the invention is so homogeneous, firmly anchored adhesive layers are obtained must be regarded as surprising and was from the prior Technology cannot be derived without an inventive step. By the application of the plastic powder to the not yet dried or solidified binder layer had to be feared that a non-closed, above all, an uneven adhesive layer is formed, which leads to poor bonding. Furthermore, it was to be assumed that the fine powder sinks into the not yet dried binder layer and so poor adhesion can arise. In addition, it must be emphasized at this point that the process to be observed in the new process Improving the bond strength of certain adhesives, e.g. B. polyamide adhesive, was not foreseeable. The order of heat-sensitive or very high-melting plastics with adhesive properties in solid form is this procedure is only possible. Also, according to the method according to the invention, support materials that are sensitive against high temperatures or solvents, damaging

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Gebr. Giulini GmbH

Lud.wigsh.af en / Rh. ,

- 5 lots can be provided with appropriate plastics.

The subject is now based on the following examples the invention will be explained in more detail:

Example 1 ■ *

A cotton fabric weighing 170 g / m², "heavily roughened on both sides in twill or plain weave is impregnated with a dispersion of the following composition:

14.7514 kg of water ■ ..

0.2066 kg of sodium polyphosphate. . -

8.3600 kg of titanium dioxide
25.5800 kg of kaolin

0.0490 kg color pigment red

0.0049 kg color pigment black

0.0340 kg color pigment yellow 19.0000 kg acrylic acid copolymer 31.0000 kg of carboxylated butadiene styrene latex

1.0000 kg ammonium bicarbonate

0.0200 kg silicone antifoam emulsion, 20%

The amount of coating is 470 g / m² dry substance if the fabric is pulled between two rollers with an automatically controlled roller gap width of about 0.95 mm. In the subsequent coating process with polyamide resin from HO ⁰ G *, 60 g of the ground hotmelt adhesive are sprinkled into the still wet coating immediately after the application with a doctor blade. It is dried at 120 ^° C ^.; -

The fabric finished in this way is wound up in Hollen and cut into sheets from which the ~

Growing srunkt

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Gebr. GiuUni GmbH Ludwigshafen / Rh.

desired stiffening parts are punched out. Example 2

On a 170 g / sqm heavy cotton twill fabric 650 g / sqm of a solid binder mixture as follows Composition at room temperature applied:

95 % polyethylene
5 % Porofor N®

The average particle size is 250 - 4-00 μm. Then a polyester with a softening point of 98 C is applied as a thermoplastic with adhesive properties, namely 60 g / m². Awake film formation at 150 ^° C. is calendered to a thickness of 1.7 mm and cooled on rollers.

= registered trademark of Bayer AG, Leverkusen

9803/0812

Claims (1)

Gebr. Oiulini GmbH
Lu.dwigsh.afen / Rh. Patient Patent claims 1.) Process for the production of with thermoplastic or sheet-like structures provided with elastic binding agent and adhesive, characterized in that the Flat structure is provided in a known manner with a binder and that on this ^ layer the adhesive layer by sprinkling a powdery Thermoplastics with adhesive properties and subsequent heating to temperatures above the Film formation temperature is formed, 2.) Method according to claim 1, characterized in that the binder is in the form of an aqueous dispersion the fabric is applied. 3.) The method according to claim 2, characterized in that the surface ge '
is heated. the fabric to a temperature above 90 ° C 4.) Process according to claims -1-5 *, characterized in that that the powdered thermoplastic is provided with a filler additive. 5.) The method according to claim 4, characterized in that a powdered thermoplastic with a particle size between 0.1 - 500 / µm is used. 6.) Process according to claims 4 and 5 »characterized in that that the powdery thermoplastic in quantities between 30 and 100 g / sqm, in particular 45 - 65 g / sqm, is applied. * Solvent-based and / or non-solidified 4th 60.98Q9 / Q812