EP1421878A1 - Moulded body, expecially cushions - Google Patents

Abstract

A molded article, preferably a seat cushion, comprises a lower bearing surface (1), a gel layer (2), comprising a polyurethane gel, having integral supports (3) separated from each other by extending channels (4), upon which a polyurethane foam layer (6) lies, whose upper face (5) is covered by an outer covering (7).

Description

The invention relates to a molded body, in particular for a seat cushion.

The invention has for its object to design such a shaped body so that it can be used especially for a seat cushion and here too a high level of seating comfort with reduced compared to conventional seat cushions Construction height and which is generally suitable for the seating area (armrests, back cushions, Neck pillow) and especially for the vehicle area where a reduction in the overall height is particularly advantageous, because this creates a larger installation space under the vehicle seat for technical installations can be created.

In its most general form, this object is achieved according to the invention by a molded body with the features of claim 1.

It is expedient if the support in the area of the load Pressure peaks are closer together, the Pad can preferably be columnar.

For ventilation purposes, it is advantageous if the upper support is a knitted spacer is that of two textiles connected by spacer threads Surfaces. The spacer fabric, known per se, is composed of one another a goods base, a goods side and from them connecting bars. The properties of a spacer knit essentially become of the binding structures, i.e. the integration of the threads in the surface, the Mesh density and the thread thickness influenced. Offer through their 3D structure Spacer fabrics have many technical advantages such as air permeability, low weight, good resilience, shock absorption, heat circulation, recyclability, Grade purity and good ductility.

Regarding special embodiments of the polyurethane foam layer as well their connection to the gel layer is based on the subjects of claims 6 to 10 referenced.

According to the invention, the gel layer consists of a polyurethane gel, the chemical of which Structure made of long polymer threads and only a few linkages without Use of added plasticizers can exist.

However, it is possible for the gel to be based on an undercrosslinked polyurethane of polyols and polyisocyanates or polyethers and polyisocyanates becomes.

According to the invention, it is expedient if the gel masses contain one raw material Isocyanate functionality of the polyol component of at least 5.2 is preferred of at least 6.5, in particular of at least 7.5.

a) einem oder mehreren Polyolen mit Hydroxylzahlen unter 112 und

b) einem oder mehreren Polyolen mit Hydroxyzahlen im Bereich von 112 bis 600 besteht,

wobei das Gewichtsverhältnis der Komponente a) zu Komponente b) zwischen 90:10 und 10:90 liegt, die Isocyanat-Kennzahl des Reaktionsgemisches im Bereich von 15 und 60 liegt und das Produkt aus Isocyanat-Funktionalität und Funktionalität der Polyolkomponente mindestens 6 beträgt.It is advantageous if the polyol component for producing the gel from a mixture

a) one or more polyols with hydroxyl numbers below 112 and

b) there is one or more polyols with hydroxyl numbers in the range from 112 to 600,

wherein the weight ratio of component a) to component b) is between 90:10 and 10:90, the isocyanate index of the reaction mixture is in the range from 15 and 60 and the product of isocyanate functionality and functionality of the polyol component is at least 6.

As an alternative solution it can be provided that the polyol component for the production of the gel from one or more polyols with a molecular weight between 1000 and 12000 and an OH number between 20 and 112, the product of the functionalities of the polyurethane-forming components is at least 5 and the isocyanate index is between 15 and 60.

Finally, it is advantageous to use such isocyanates for gel production of the formula Q (NCO), in which n is 2 to 4 and Q is an aliphatic Hydrocarbon residue with 8 to 18 carbon atoms, a cycloaliphatic hydrocarbon residue with 4 to 15 carbon atoms, an aromatic hydrocarbon residue with 6 to 15 carbon atoms or an araliphatic hydrocarbon radical with 8 to 15 carbon atoms, and if the polyurethane with isocyanates in pure form or with urethanized, allophanized, biurethized or functionally modified isocyanates.

The patent EP 57 838 claims gels to prevent pressure ulcers, which characterized by a low key figure, i.e. by so-called sub-networking are. They are made by reacting a polyisocyanate with long chain Polyols, which should be free of short-chain components, are produced. This Dimensionally stable gels made from polyurethane raw materials can be used as mattresses, mattress inserts, Automotive seats and as upholstery material. The Patent EP 511 570 discloses improved gels made from polyols and isocyanates low key figures, which consist of mixtures of long-chain and short-chain polyethers getting produced. To manufacture the processing technology cheaper Polyol and polyiscyanate mixtures are preferred as cushioning material in the shoe industry, as requirements to avoid or prevent of injuries, face masks, as padding for horse saddles as well in other applications.

The known polyol and isocyanate mixtures always have the disadvantage of high weight and the associated high heat capacity for the above-mentioned applications. Due to the high weight of approximately 1.0 g / cm ³ , use is restricted to applications in which the weight plays a subordinate role in relation to the excellent pressure-distributing properties. In addition, the high thermal capacity of the polyurethane gel in direct body contact can be perceived as unpleasant, since body heat is clearly perceptible to the body to warm up the respective gel masses.

Various methods and patents are described in patent DE 43 08 445 A1 (EP-B 0 057 839; WO-88/01878; EP 0 453 286) for the production of gel foams with air, nitrogen and carbon dioxide. The reduction of specific weight and associated reduction in heat capacity are achieved to the desired extent, but the gels have the disadvantage that the cells formed under pressure on the inner walls of the cell the very high self-adhesive behavior of the reaction products, which are always cross-linked glue based on polyols and polyisocyanates. Beyond pose the cells represent a weakening of the gel matrix, which negatively affects the mechanical Properties such as elongation at break and tensile strength. Also returns a cellular gel slower to return to its starting position after exercise. Of Furthermore, shrinkage problems can arise, as they arise from the processing of Polyurethane foams are known.

Another disadvantage of the polyurethane gels described is the one-seat behavior. Especially on the first contact, a gel cushion is often felt to be hard, because only with a time delay does the gel reach the desired optimal one Pressure distribution guaranteeing position flows or has flowed.

A gel mass that significantly reduces weight, heat capacity and the comfort of the seat while maintaining the typical gel properties, such as. the absorption of shear forces means a clear one technical improvement.

The gel masses to be used for the gel layer provided according to the invention should avoid the disadvantages mentioned above and the typical advantageous ones Gel properties with a low specific weight overall lower thermal conductivity as well as good durability and permanently the same connect lasting utility model properties. It is therefore advantageous if the gel layer contains elastic hollow microspheres as filler, the hollow microspheres consist of polymeric material, preferably polyolefin and with a cover layer made of an inorganic material, preferably calcium carbonate, are coated.

It is advantageous if the hollow microspheres have a diameter of 10 μm to 150 µm, and if the proportion of micro-spheres in the gel material 0.1-10% by weight.

Overall, the seating comfort can be improved by the fact that the gel mass coarse-grained solid particles are distributed, which consist of cork pieces, cork flour, Pieces of wood, wood shavings, foam flakes, polystyrene, textile fibers or textile pieces, the diameter of which is preferably between 0.1 mm and 15 mm.

According to the invention, the single-seat comfort is due to the overhead polyurethane foam layer significantly improved.

Figur 1 -

im Querschnitt einen Formkörper mit einer unteren Gellage und einer oberen Schaumstofflage;

Figur 2 -

in einer Darstellung gemäß Figur 1 eine mit unteren Ansätzen in Ausdehungskanäle der Gellager eintauchende Schaumstofflage;

Figur 3 -

in einer Darstellung gemäß Figur 2 eine die Gellage seitlich einfassende Schaumstofflage, deren untere Ansätze sich bis auf den Boden der Ausdehnungskanäle erstrecken; und

Figur 4 -

in einer Darstellung gemäß Figur 2 eine untere Gellage mit unterschiedlich gestalteten Ausdehnungskanälen.

Some exemplary embodiments of the invention are shown in the drawing. Show it:

Figure 1 -

in cross section a molded body with a lower gel layer and an upper foam layer;

Figure 2 -

in a representation according to FIG. 1, a foam layer immersed with lower shoulders in expansion channels of the gel bearings;

Figure 3 -

in a representation according to FIG. 2, a foam layer enclosing the gel layer laterally, the lower lugs of which extend to the bottom of the expansion channels; and

Figure 4 -

in a representation according to Figure 2, a lower gel layer with differently shaped expansion channels.

FIG. 1 shows in cross section a molded body which serves in particular as a seat cushion, with a lower, load-bearing, forming a lower bearing surface 1 a gel layer 2 consisting of polyurethane gel, which is integral on its upper side, has supports 3 spaced apart from one another via expansion channels 4 which a polyurethane foam layer 6 rests, the top 5 by a upper edition 7 is covered.

In the modified embodiment shown in FIG. 2, the polyurethane foam layer has 6 on their underside integral approaches 6a, which in the Immerse expansion channels 4 of gel layer 2.

In the embodiment according to FIG. 3, the integral approaches extend 6a of the polyurethane foam layer 6 down to the bottom 8 of the expansion channels and can rely on it. Figure 3 also shows that the polyurethane foam layer 6 completely surrounds the gel layer 2 on the side.

Figure 4 shows a further modified embodiment, the quasi a combination of the embodiments according to Figures 1 and 3. Because here expansion channels 4 are provided on the one hand, which are free of lower approaches the polyurethane foam layer 6, but with integral approaches 6a in Expansion channels of less depth and smaller cross-section immersed, wherein these approaches 6a are supported on the bottom 8 of these expansion channels can.

The gel layer 2 can be removed after pulling off a film produced together with it the polyurethane foam layer 6 may be glued. Alternatively, the polyurethane foam layer could also with an applied adhesive with the supports the gel layer be glued.

In all embodiments, the upper pad 7 is a spacer fabric that consists of two textile surfaces connected by spacer threads.

The main advantages of the molded body according to the invention can be seen in the increased seating comfort with reduced height, the favorable ventilation properties, the good pressure distribution, soft seating and in the reduced weight compared to a pure gel seat.

Claims (24)

Shaped body, in particular for a seat cushion, with a lower, load-bearing a lower contact surface (1), consisting of a polyurethane gel Gel layer (2), which is integral on top of each other Expansion channels (4) spaced supports (3) on which one Polyurethane foam layer (6) rests, the top (5) by a upper support (7) is covered. Shaped body according to claim 1, characterized in that the supports (3) have a closer spacing from one another in the region of the pressure peaks occurring under load. Shaped body according to claim 1 or 2, characterized in that the supports (3) are columnar. Shaped body according to claim 1, 2 or 3, characterized in that the polyurethane foam layer (6) on its underside has integral shoulders (6a) which plunge into the expansion channels (4) of the gel layer (2). Shaped body according to one of the preceding claims, characterized in that the upper support (7) is a spacer fabric, which consists of two textile surfaces which are connected to one another by spacer threads. Shaped body according to one of the preceding claims, characterized in that the polyurethane foam layer (6) completely or partially surrounds the gel layer (2) laterally. Shaped body according to one of the preceding claims, characterized in that the gel layer (2) is glued to the polyurethane foam layer (6) after pulling off a film produced together with it. Shaped body according to one of claims 1 to 6, characterized in that the polyurethane foam layer (6) is glued to the supports (3) of the gel layer (2) by means of an applied adhesive. Shaped body according to one of claims 4 to 8, characterized in that the integral shoulders (6a) of the polyurethane foam layer (6) extend to the bottom (8) of the expansion channels (4). Shaped body according to claim 9, characterized in that the lugs (6a) of the polyurethane foam layer (6) are supported on the bottom (8) of the expansion channels (4). Shaped body according to one of the preceding claims, characterized in that the chemical structure of the polyurethane gel consists of long polymer threads and only a few linkages without the use of added plasticizers. Shaped body according to one of claims 1 to 10, characterized in that a sub-crosslinked polyurethane based on polyols and polyisocyanates or polyethers and polyisocyanates is used for the gel. Shaped body according to claim 12, characterized in that the gel compositions are made with raw materials having an isocyanate functionality of the polyol component of at least 5.2, preferably at least 6.5, in particular at least 7.5. Shaped body according to claim 12 or 13, characterized in that the polyol component for producing the gel from a mixture a) one or more polyols with hydroxyl numbers below 112 and b) there is one or more polyols with hydroxyl numbers in the range from 112 to 600, wherein the weight ratio of component a) to component b) is between 90:10 and 10:90, the isocyanate index of the reaction mixture is in the range from 15 and 60 and the product of isocyanate functionality and functionality of the polyol component is at least 6. Shaped body according to claim 12 or 13, characterized in that the polyol component for the production of the gel consists of one or more polyols with a molecular weight between 1000 and 12000 and an OH number between 20 and 112, the product of the functionalities of the polyurethane-forming components being at least 5 is and the isocyanate index is between 15 and 60. Shaped body according to one of claims 12 to 15, characterized in that the isocyanates used for gel preparation are those of the formula Q (NCO), in which n is 2 to 4 and Q is an aliphatic hydrocarbon radical having 8 to 18 carbon atoms, a cycloaliphatic Hydrocarbon residue with 4 to 15 carbon atoms, an aromatic hydrocarbon residue with 6 to 15 carbon atoms or an araliphatic hydrocarbon residue with 8 to 15 carbon atoms. Shaped body according to one of claims 12 to 16, characterized in that the polyurethane is produced with isocyanates in pure form or with urethanized, allophanized, biurethized or functionally appropriately modified isocyanates. Shaped body according to one of the preceding claims, characterized in that the gel layer (2) contains elastic hollow microspheres as filler. Shaped body according to claim 18, characterized in that the hollow microspheres consist of polymeric material, preferably polyolefin. Shaped body according to claim 18 or 19, characterized in that the hollow microspheres are coated with a cover layer made of an inorganic material, preferably calcium carbonate. Shaped body according to claim 18, 19 or 20, characterized in that the hollow microspheres have a diameter of 10 µm to 150 µm. Shaped body according to one of claims 18 to 21, characterized in that the proportion of hollow microspheres in the gel material is 0.1 to 10% by weight. Shaped body according to one of the preceding claims, characterized in that coarse-grained solid particles are distributed in the gel mass, which consist of cork pieces, cork flour, pieces of wood, wood chips, foam flakes, styrofoam, textile fibers or textile pieces. Shaped body according to claim 23, characterized in that the diameter of the solid particles is between 0.1 and 15 mm.

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