SE510065C2 - Elastic laminate material without chlorine compounds, suitable for body contact - Google Patents

Abstract

An elastic laminate material (multi-layer material, sandwich material) intended to be used for various purposes in which the material may be used in direct contact with human skin, and which comprises a base material (1) of an elastic, porous foam material, preferably a material having closed cells, and a stretchable or elastic surface layer (2) on one side or on both sides thereof, preferably a knitted material like a "stretch material", a tricot/woven material, a piquet material etc., which has been fixed to the base material (1) by means of an intermediate glue layer (3), and in which the base material (1) comprises an elastomeric material which does not contain any chlorine compounds, for instance EPDM rubber, SBR rubber or NBR rubber, and in which the glue layer (3) comprises a thermoplastic melt glue of the type which is dry and non-sticking in cold condition but which has good adhesive properties in heated condition, for instance an EVA glue, a glue of polyolefine, a poylester, a polyethylene or a polyurethane.

Description

10 15 20 25 30 35 of freezing etc., and the described laminate of the chloroprene foam rubber, stretch-Nylon and contact adhesive film have been used for it for a number of years stated purpose.

However, it has turned out - partly that the foam rubber material can cause skin rashes or allergies, especially for people with sensitive skin, probably due to the fact that the chloroprene material can emit irritating chlorine compounds; - partly also that the binder in the contact adhesive, which may consist of toluene, xylene and similar aromatic hydrocarbons, can migrate and emit odors and residues of toluene and other hydrocarbons, as well as residues of heavy metals, which also can cause adverse skin reactions and create irritating odor.

Due to these properties of the material, the material has not been able to certified to the desired class according to ÖKOTEX standard 100, product class 2. Det it can be expected that there will soon be EU directives in this area as well.

The basis for the invention has therefore been to achieve the problem an elastic laminate material consisting of a body of an elastic closed cell foam material, an extensible or elastic, preferably knitted surface layer material and a similarly stretchable or elastic adhesive between the foam material body and the surface layer material, which laminate material lacks Ingredients that may emit and cause skin rashes, allergies or disturbances odor, and which can be used in direct skin contact even by people with a lot Sensitive Skin. The object of the invention has been to find an elastic body material of foam rubber type, which is free from chlorine compounds and others compounds that can cause skin problems or other unwanted effects, and that find a material that can be used for strong and safe gluing together the laminate.

A possible foam material for the laminate body is an elastomer of the type ethylene-propylene-diene terpolymer, so-called EPDM rubber, which elastomer can provided as a closed cell synthetic foam rubber material, and which has been shown to give at least the same technically sound effect as before commonly use chloroprene foam rubber, but which lacks the undesirable effects of chloroprene foam rubber. The EPDM foam can be sulfur vulcanized or peroxide vulcanized and temperature cured.

Other possible foam materials for the material body are styrene- butadiene rubber (SSBR rubber), acrylonitrile-butadiene rubber (NBF1 rubber). The 10 15 20 25 30 35 510 065 is also possible to use any type of urethane. However, SER rubber provides not as good quality as EPDM foam rubber; NBR rubber can in case of prolonged use give rise to certain medically adverse effects; and urethane rubber is not as hydrolysis resistant as EPDM rubber and can undergo changes during prolonged contact with water.

One problem with EPDM foam rubber is that it is difficult to glue, and that it can therefore be difficult to get the surface layer of textile material to adhere to EPDM foam rubber. Extensive experiments, however, have surprisingly shown that it is possible to achieve both a strong and elastic joint between the EPDM the foam rubber and the textile layer by means of a thermoplastic hot melt adhesive, e.g. in the form of an adhesive film or a melt adhesive in powder form, which glue lacks adhesion (does not smudge) in the cold state, but which has good adhesion when heating, especially in combination with pressure treatment.

The adhesive must not contain any medically unsuitable substances or environmentally harmful ingredients, and it must be so stretchy or elastic that it stretches more than the foam rubber material, eg more than 200%. The glue should too be water-resistant and have good weather-resistant properties, it should be resistant to UV radiation, and it should be such that no damage occurs in the adhesive even with strong bending and breaking of the laminate foam rubber material and fabric.

A well-suited adhesive is an ethylene-vinyl acetate adhesive, commonly referred to as EVA glue, which gives an elastic and very good joint when heated and at the same time compression of foam rubber, adhesive film or powder and the textile layer.

Glue joining can take place at a temperature of 120-180 ° C and at a pressure of 4-8 bar for a time of 10-20 seconds. Gluing can, for example, take place through known so-called "hot-melt technology" and using some type of heat exchanger, e.g. IR heater, or by other known techniques.

Other useful adhesives are polyolefins or polyesters. It is too possible to use polyethylene film or polyurethane adhesive film.

The adhesive film may be an EVA film or a polyolefin film or polyester film, which is perforated. Alternatively, you can use a thin one film of other materials, on which adhesive points of EVA, a polyolefin or a polyester has been applied, and which are activated to provide an adhesive joint through heat and pressure.

It is very difficult to make an adhesive joint on a hydrocarbon material of type EPDM foam rubber. It is therefore surprising that a very good, 10 15 20 25 30 35 510 065 strong, water-resistant and stretchable or elastic adhesive joint with good weather resistance and good cooling properties can be achieved between EPDM the foam rubber and the textile material by means of a thermoplastic adhesive film or a thermoplastic powder of the type mentioned.

The laminate material in question in the present case must be such that it can be used as clothing material, which can be sewn, glued, possibly. welded.

Figure 1 shows an exploded view of a laminate material according to FIG the invention. Figure 2 schematically shows the way to join together the laminate parts. Figures 3, 4 and 5 are diagrams showing different properties of a laminate according to the invention.

The laminate material shown in Figures 1 and 2 consists of a frame 1 of a synthetic foam material with closed cells, for example an EPDM foam rubber, which is laminated together with a surface layer 2 of a textile material, e.g. a knitted textile material such as stretch-Nylon. The glue joint 3 is shown in this case consist of an adhesive film of a thermoplastic hot melt adhesive, for example an ethylene-vinyl acetate glue, commonly called EVA glue. The adhesive foil appears perforated, which improves the elastic properties of the adhesive film. It is alternatively possible that instead of use an adhesive film to spray the foam rubber body 1 and / or the surface layer 2 with a dry powder of the same type of material, or to drip on melted drops of an adhesive on the body 1 and / or the surface layer 2.

As schematically indicated in Figure 2, the gluing of frame 1 takes place. which may have a thickness of 1.5-10 mm, a surface layer 2, which may have a thickness of up to 0.3-1.5 mm, and the intermediate adhesive film 3 by a pressure 4 is applied, eg a pressure of 4-8 bar, at the same time as the adhesive film is heated to a temperature of 120-180 ° C. The heat can be provided by IR radiation or other known technology. The pressure and heat are maintained for a period of 10- 20 seconds.

As an alternative to the mentioned foam rubber material of the EPDM type any other closed cell foam type elastomer can be used, e.g. rubber or NBR rubber.

As an alternative to the stretchable or elastic adhesive film of EVA can use a corresponding adhesive film of a polyolefin, a polyester, polyethylene, or possibly polyurethane.

To assess different properties of a laminate material consisting of a chlorine-free foam rubber material and a textile sound layer and with an adhesive joint of one thermoplastic hot melt adhesive, a number of different studies have been done by different 10 15 20 25 30 35 510 065 laminate combinations, which are shown in Figures 3, 4 and 5. Figure 3 shows the tensile strength of the new laminate to break after 1-8 washes of the material at 40 ° C temperature; Figure 4 shows the elongation at break of the laminate, likewise after 1-8 washes; and Figure 5 shows the peeling of the surface layer from the body material at different peeling forces and likewise after 1-8 washing of the laminate. As reference material was used in all examinations a laminate material of the previously mentioned known type consisting of chloroprene foam rubber, stretch-Nylon and a contact adhesive of well-known variety.

ANALYSIS OF LAMINATE WITH THERMOPLASTIC UMFILMS A number of different films have been investigated with respect to the possibility of provide an adhesive joint between EPDM foam rubber and a stretch nylon material. The adhesive films were provided by Borealis and were designated 0EO467, EVA OE5019, EEA OE5810 and EBA 0E6420. The film thickness was 80 in all cases um. The EPDM foam had a thickness of 3.5 mm, and the surface layer consisted of stretch-Nylon with a thickness of about 1 mm. The EPDM foam rubber had the following composition: Polymer EPDM 32% Emollient: mineral oil 29% Carbon black 15% Filler material: calcium carbonate with any proportion of Al, Si and traces of Zn, Ti 24%.

It has been found possible to vary the thickness of the foam material between eg 1.5 and 10 mm, and that the fabric material can be given a thickness of eg 0.3-1.5 mm.

The following tests were performed: tensile strength, shown in Figure 3, elongation at break, shown in Figure 4 and the peeling force, shown in Figure 5.

For assessment of tensile strength to fracture and elongation of assessments were made after the laminate had been washed 2, 4 and 4, respectively 8 times. The washing took place at 40 ° C and the laminate was dried in air.

The test was performed on a laminate material 3.5 mm thick.

The diagrams in Figures 3 and 4 show that the tensile strength to fracture and the elongation of the material remained virtually unchanged after these 8 10 15 20 25 510 065 washes. The results of the tensile strength tests according to Figure 3 show also that the tensile strength of the fracture was practically the same as for it previously known Chloroprene contact adhesive material, which was used as a reference material. Figure 4 shows that the crime extension was slightly smaller the reference material, with the small difference was judged negligible.

Furthermore, a peeling survey was conducted as a function of the number of washes. The examinations were performed so that a traction force was applied between the foam rubber material and the textile light layer. The result is reported in Figure 5.

It appears that the peeling strength was almost unchanged after all washes.

It also appears that the peeling strength was actually greater for this current new material than for the previously known "Chloroprene material".

The flexural strength was examined in further experiments after fictitious aging by UV irradiation. It turned out that the laminate materials showed one only slightly increased stiffness after the 8 washes and UV irradiation. lngen increase in stiffness could also be noted after the laminate pieces were exposed for freezing.

It could be determined that the adhesion using the thermoplastic the films were satisfactory for all specified films, and that the adhesion did not showed some noticeable decrease after 8 washes. The UV treatment led to an insignificant reduction in tensile strength and elongation at break. lngen reduction of the delamination force could be observed after 100 hours of UV irradiation. Freezing of the laminate does not seem to affect the properties of either the materials according to the flexural strength test.

It could also be stated that the new laminate material in all respects showed the same good technical properties as before known "Chloroprene material". No emission of chlorine compounds or others harmful compounds may be present in the new material, nor do they emit the thermoplastic adhesive layer any substances or any odor.

Claims (8)

10 15 20 25 30 35 PATENT REQUIREMENTS An elastic laminate material (multilayer material, sandwich material) intended for use in various contexts where the material may be used in direct contact with human skin and consisting of a body (1) of an elastic, porous foam material, preferably a closed cell material, and an extensible surface layer (2) on one or both sides thereof, preferably a knitted material such as a "stretch material", a knitted / woven material, a piqué material or similar material, which is fixed to the body (1) by means of an intermediate adhesive layer (3), characterized in that the body consists of an elastomer without content of any chlorine compounds, such as a foam material of a polymer of the type ethylene-propylene-butadiene terpolymer material (EPDM) or a foam rubber material of a thermoplastic elastomer such as styrene-butadiene rubber (SBR) or acrylonitrile-butadiene rubber (NBR), and in that the adhesive layer (3) consists of a thermoplastic hot-melt adhesive of the type which is dry and tack-free in cold condition but has good gluing properties when heated. A laminate material according to claim 1, characterized in that the adhesive joint consists of a thermoplastic hot melt adhesive (3) in the form of an adhesive foil, a dry adhesive powder or adhesive clicks applied to the foam rubber body (1) and / or to the surface layer (2) of textile material. A laminate material according to claim 2, characterized in that the adhesive foil is perforated. A laminate material according to claim 2 or 3, characterized in that the adhesive layer consists of an ethylene-vinyl acetate adhesive (EVA). A laminate material according to claim 2 or 3, characterized in that the adhesive layer consists of a polyolefin, a polyester, a polyethylene or a polyurethane material. A laminate material according to any one of the preceding claims, characterized in that the adhesive layer has an optimal melting point for adhesion of 120-180 ° C. A laminate material according to any one of the preceding claims, characterized in that the laminate consists of a foam rubber body (1) with a thickness of, for example, between 1.5 and 10 mm, a textile sound layer on either or both sides of the foam rubber body (1) with a thickness of about 1 mm, and where the laminate is glued together with a pressure of 4-8 bar and a temperature of 120-180 ° C for a gluing time of 10-20 seconds. 510 065 A laminate material according to any one of the preceding claims, characterized by the laminate material has such a structure and structure that it can be used as a clothing material, which can be sewn, glued or possibly. welded.