U.S. patent application number 10/715397 was filed with the patent office on 2004-05-27 for shaped body, in particular for a seat cushion.
Invention is credited to Gansen, Peter, Stender, Adolf.
Application Number | 20040098806 10/715397 |
Document ID | / |
Family ID | 32185916 |
Filed Date | 2004-05-27 |
United States Patent
Application |
20040098806 |
Kind Code |
A1 |
Stender, Adolf ; et
al. |
May 27, 2004 |
Shaped body, in particular for a seat cushion
Abstract
The invention relates to a shaped body, in particular for a seat
cushion, having a lower, supporting gel layer (2) which forms a
lower covering surface (1), consists of a polyurethane gel and, on
its upper side, has integral supports (3) which are spaced apart
from one another via expansion channels (4) and on which a
polyurethane foam layer (6) rests, the upper side (5) of which
layer is covered by an upper covering (7).
Inventors: |
Stender, Adolf;
(Duderstatdt, DE) ; Gansen, Peter; (Seeburg,
DE) |
Correspondence
Address: |
Whitham, Curtis & Chistofferson, P.C.
Suite 340
11491 Sunset Hills Road
Reston
VA
20190
US
|
Family ID: |
32185916 |
Appl. No.: |
10/715397 |
Filed: |
November 19, 2003 |
Current U.S.
Class: |
5/654 ; 5/655.9;
5/909 |
Current CPC
Class: |
A47C 27/144 20130101;
A47C 27/085 20130101; A61G 5/1045 20161101; A61G 5/1043 20130101;
A61G 7/05738 20130101; A47C 7/021 20130101; A47C 27/15 20130101;
A47C 27/086 20130101; A47C 31/006 20130101; A47C 27/20 20130101;
A47C 27/18 20130101 |
Class at
Publication: |
005/654 ;
005/909; 005/655.9 |
International
Class: |
A47C 027/14; A47C
027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 22, 2002 |
DE |
102 54 678.9 |
Claims
1. A shaped body, in particular for a seat cushion, having a lower,
supporting gel layer (2) which forms a lower covering surface (1),
consists of a polyurethane gel and, on its upper side, has integral
supports (3) which are spaced apart from one another via expansion
channels (4) and on which a polyurethane foam layer (6) rests, the
upper side (5) of which layer is covered by an upper covering
(7).
2. The shaped body as claimed in claim 1, wherein the supports (3)
are at a narrower distance from one another in the region of the
pressure peaks which occur under load.
3. The shaped body as claimed in claim 1 or 2, wherein the supports
(3) are of columnar design.
4. The shaped body as claimed in claim 1, 2 or 3, wherein the
polyurethane foam layer (6) has, on its lower side, integral
projections (6a) which enter into the expansion channels (4) of the
gel layer (2).
5. The shaped body as claimed in one of the preceding claims,
wherein the upper covering (7) is a spacer knit which consists of
two textile surfaces connected to each other by spacer threads.
6. The shaped body as claimed in one of the preceding claims,
wherein the polyurethane foam layer (6) completely or partially
laterally encloses the gel layer (2).
7. The shaped body as claimed in one of the preceding claims,
wherein the gel layer (2), after a film has been produced together
with it pulled off, is bonded to the polyurethane foam layer
(6).
8. The shaped body as claimed in one of claims 1 to 6, wherein the
polyurethane foam layer (6) is bonded to the supports (3) of the
gel layer (2) by an applied adhesive.
9. The shaped body as claimed in one of claims 4 to 8, wherein the
integral projections (6a) of the polyurethane foam layer (6) extend
as far as the bottom (8) of the expansion channels (4).
10. The shaped body as claimed in claim 9, wherein the projections
(6a) of the polyurethane foam layer (6) are supported on the bottom
(8) of the expansion channels (4).
11. The shaped body as claimed in one of the preceding claims,
wherein the chemical structure of the polyurethane gel consists of
long polymer threads and only a few linkages without added
plasticizers being used.
12. The shaped body as claimed in one of claims 1 to 10, wherein an
undercrosslinked polyurethane based on polyols and polyisocyanates
or polyethers and polyisocyanates is used for the gel.
13. The shaped body as claimed in claim 12, wherein the gel
compounds are produced using starting materials having an
isocyanate functionality of the polyol component of at least 5.2,
preferably of at least 6.5, in particular of at least 7.5.
14. The shaped body as claimed in claim 12 or 13, wherein the
polyol component for producing the gel consists of a mixture of a)
one or more polyols having hydroxyl numbers under 112, and b) one
or more polyols having hydroxyl numbers in the range of from 112 to
600, the weight ratio of component a) to component b) being between
90:10 and 10:90, the characteristic isocyanate number of the
reaction mixture lying in the range of from 15 to 60, and the
product from the isocyanate functionality and functionality of the
polyol component being at least 6.
15. The shaped body as claimed in claim 12 or 13, wherein the
polyol component for producing the gel consists of one or more
polyols having a molecular weight of between 1000 and 12,000 and an
OH number of between 20 and 112, the product of the functionalities
of the polyurethane-forming components being at least 5 and the
characteristic isocyanate number being between 15 and 60.
16. The shaped body as claimed in one of claims 12 to 15, wherein
the isocyanates used for the production of the gels 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 C atoms, a cycloaliphatic
hydrocarbon radical having 4 to 15 C atoms, an aromatic hydrocarbon
radical having 6 to 15 C atoms or an araliphatic hydrocarbon
radical having 8 to 15 C atoms.
17. The shaped body as claimed in one of claims 12 to 16, wherein
the polyurethane is produced with isocyanates in a pure form or
with urethanized, allophanisized, biurethisized or functionally
correspondingly modified isocyanates.
18. The shaped body as claimed in one of the preceding claims,
wherein the gel layer (2) contains elastic hollow microbeads as
filler.
19. The shaped body as claimed in claim 18, wherein the hollow
microbeads consist of polymeric material, preferably
polyolefin.
20. The shaped body as claimed in claim 18 or 19, wherein the
hollow microbeads are coated with a covering layer of an organic
material, preferably calcium carbonate.
21. The shaped body as claimed in claim 18, 19 or 20, wherein the
hollow microbeads have a diameter of 10 .mu.m to 150 .mu.m.
22. The shaped body as claimed in one of claims 18 to 21, wherein
the content of hollow microbeads in the gel material is 0.1 to 10%
by weight.
23. The shaped body as claimed in one of the preceding claims,
wherein coarse-grained solid particles consisting of small pieces
of cork, cork powder, small pieces of wood, wood shavings, foam
flakes, styropor, textile fibers or pieces or textile are
distributed in the gel compound.
24. The shaped body as claimed in claim 23, wherein the diameter of
the solid particles is between 0.1 and 15 mm.
Description
[0001] The invention relates to a shaped body, in particular for a
seat cushion.
[0002] The invention is based on the object of designing a shaped
body of this type in such a manner that it can be used, in
particular, for a seat cushion and results here in high seating
comfort with an overall height which is reduced in comparison to
conventional seat cushions and which can be used in general for the
sphere of seating furniture (armrests, back cushions, neck
cushions) and, in particular, also for the vehicle sector, in which
a reduction in the overall height is particularly advantageous,
since this enables a higher installation space to be provided under
the vehicle seat for technical internal components.
[0003] According to the invention, this object is achieved in its
most general form by a shaped body having the features of claim
1.
[0004] In this case, it is expedient if the supports are at a
narrower distance from one another in the region of the pressure
peaks which occur under load, it preferably being possible for the
supports to be of columnar design.
[0005] For ventilation purposes, it is advantageous if the upper
covering is a spacer knit which consists of two textile surfaces
connected to each other by spacer threads. The spacer knit, which
is known per se, is composed of a fabric base, a fabric side and of
connecting bars connecting them to each other. The properties of a
spacer knit are substantially influenced by the binding structures,
i.e. the binding of the threads into the surface, the mesh density
and the mesh strength. Owing to their 3D structure, spacer knits
provide many technical advantages, such as air permeability, low
weight, good restoring behavior, shock absorption, circulation of
heat, recycleability, purity of quality and good deformability.
[0006] Reference is made to the subject matters of claims 6 to 10
in respect of special embodiments of the polyurethane foam layer
and its connection to the gel layer.
[0007] According to the invention, the gel layer consists of a
polyurethane gel, the chemical structure of which can consist of
long polymer threads and only a few linkages without added
plasticizers being used.
[0008] However, it is possible for an undercrosslinked polyurethane
based on polyols and polyisocyanates or polyethers and
polyisocyanates to be used for the gel.
[0009] According to the invention, it is expedient if the gel
compounds are produced using starting materials having an
isocyanate functionality of the polyol component of at least 5.2,
preferably of at least 6.5, in particular of at least 7.5.
[0010] In this case, it is advantageous if the polyol component for
producing the gel consists of a mixture of
[0011] a) one or more polyols having hydroxyl numbers under 112,
and
[0012] b) one or more polyols having hydroxyl numbers in the range
of from 112 to 600,
[0013] the weight ratio of component a) to component b) being
between 90:10 and 10:90, the characteristic isocyanate number of
the reaction mixture being in the range of 15 to 60, and the
product from the isocyanate functionality and functionality of the
polyol component being at least 6.
[0014] As an alternative solution, it can be provided that the
polyol component for producing the gel consists of one or more
polyols having a molecular weight of between 1000 and 12,000 and an
OH number of between 20 and 112, the product of the functionalities
of the polyurethane-forming components being at least 5 and the
characteristic isocyanate number being between 15 and 60.
[0015] Finally, it is advantageous if the isocyanates used for the
production of the gels 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
C atoms, a cycloaliphatic hydrocarbon radical having 4 to 15 C
atoms, an aromatic hydrocarbon radical having 6 to 15 C atoms or an
araliphatic hydrocarbon radical having 8 to 15 C atoms, and if the
polyurethane is produced with isocyanates in a pure form or with
urethanized, allophanisized, biurethisized or functionally
correspondingly modified isocyanates.
[0016] Patent EP 57 838 claims gels for avoiding decubitus, which
are characterized by a low characteristic number, i.e. by
"undercrosslinking". They are produced by reaction of a
polyisocyanate with long-chain polyols which are to be free of
short-chain components. These dimensionally stable gels from
polyurethane starting materials can be used as mattresses, mattress
inserts, car seats and as padding material. The patent EP 511 570
discloses improved gels consisting of polyols and isocyanates with
low characteristic numbers which are produced from mixtures of
long-chain and short-chain polyethers. The polyol and
polyisocyanate mixtures which can be produced more favorably in
terms of processing technology are preferably used as padding
material in the shoe industry, as coverings for avoiding or
preventing injuries, for face masks, as paddings of horses' saddles
and in other applications.
[0017] For the applications mentioned above by way of example, the
known polyol and isocyanate mixtures consistently have the
disadvantage of the high dead weight and the high heat capacity
which is associated therewith. The high dead weight of
approximately 1.0 g/cm.sup.3 means that the use is restricted to
applications in which the weight plays a secondary role in relation
to the excellent pressure-distributing properties. Moreover, the
high-heat capacity of the polyurethane gel may be perceived as
being unpleasant when in direct body contact, since body heat is
taken from the body in a clearly noticeable manner to heat up the
particular gel compounds.
[0018] Patent DE 43 08 445 A1 mentions various processes and patent
specifications (EP-B 0 057 839; WO-88/01878; EP 0 453 286) for
producing gel foams with air, nitrogen and carbon dioxide. The
reduction in the specific weight and the associated reduction in
the heat capacity are achieved to the desired extent, but the gels
have the disadvantage that the cells which are formed when
subjected to a compressive stress bond to the inner walls of the
cells due to the very high self-adhesive behavior of the reaction
products which are always undercrosslinked and are based on polyols
and polyisocyanates. Moreover, the cells constitute a weakening of
the gel matrix which has a negative effect on the mechanical
properties, such as elongation at break and tensile strength. The
cellular gel also returns more slowly into its starting position
after having been subjected to a load. Furthermore, shrinkage
problems, as are known from processing polyurethane foams, may
occur.
[0019] A further disadvantage of the polyurethane gels described is
the behavior when sat on. A gel cushion is frequently perceived as
being hard, in particular on first contact, because the gel does
not flow or has not flowed into the desired position guaranteeing
optimum distribution of pressure until after a time delay.
[0020] A gel compound which makes possible a significant reduction
in the weight and the heat capacity and a significant improvement
in the comfort when sat on while retaining the typical gel
properties, for example, the absorption of shearing forces,
signifies a significant technical improvement.
[0021] The gel compounds which are to be used for the gel layer
provided according to the invention are intended to avoid the
abovementioned disadvantages and are intended to join the typical
advantageous gel properties with a low specific weight, an overall
lower heat conducting capacity and good durability and properties
concerning the pattern of use which remain uniform over the long
term. It is therefore advantageous if the gel layer contains
elastic hollow microbeads as filler, the hollow microbeads
consisting of polymeric material, preferably polyolefin, and being
coated with a covering layer of an inorganic material, preferably
calcium carbonate.
[0022] It is advantageous if the hollow microbeads have a diameter
of 10 .mu.m to 150 .mu.m, and if the content of hollow microbeads
in the gel material is 0.1 to 10% by weight.
[0023] The seating comfort can be overall further improved by
coarse-grained solid particles which consist of small pieces of
cork, cork powder, small pieces of wood, wood shavings, foam
flakes, styropor, textile fibers or textile pieces, the diameter of
which solid particles is preferably between 0.1 mm and 15 mm, being
distributed in the gel compound.
[0024] According to the invention, the comfort when sat on is
substantially improved by the above polyurethane foam layer.
[0025] The drawing illustrates a number of embodiments of the
invention which are used as examples. In the drawing:
[0026] FIG. 1 shows, in cross section, a shaped body having a lower
gel layer and an upper foam layer;
[0027] FIG. 2 shows, in an illustration according to FIG. 1, a foam
layer which enters with lower projections into expansion channels
of the gel layer;
[0028] FIG. 3 shows, in an illustration according to FIG. 2, a foam
layer which laterally surrounds the gel layer and the lower
projections of which extend as far as the bottom of the expansion
channels; and
[0029] FIG. 4 shows, in an illustration according to FIG. 2, a
lower gel layer having expansion channels of different design.
[0030] FIG. 1 shows, in cross section, a shaped body which is used,
in particular, as a seat cushion and has a lower, supporting gel
layer 2 which forms a lower covering surface 1, consists of a
polyurethane gel and, on its upper side, has integral supports 3
which are spaced apart from one another via expansion channels 4
and on which a polyurethane foam layer 6 rests, the upper side 5 of
which layer is covered by an upper covering 7.
[0031] In the modified embodiment illustrated in FIG. 2, the
polyurethane foam layer 6 has, on its lower side, integral
projections 6a which enter into the expansion channels 4 of the gel
layer 2.
[0032] In the embodiment according to FIG. 3, the integral
projections 6a of the polyurethane foam layer 6 extend as far as
the bottom 8 of the expansion channels and can be supported on the
latter. Furthermore, FIG. 3 shows that the polyurethane foam layer
6 laterally completely surrounds the gel layer 2.
[0033] FIG. 4 shows a further modified embodiment which to a
certain extent constitutes a combination of the embodiments
according to FIGS. 1 and 3. This is because in this case, on the
one hand, expansion channels 4 are provided which are free of lower
projections of the polyurethane foam layer 6, but enter with
integral projections 6a into expansion channels of smaller depth
and smaller cross section, it being possible for these projections
6a to be supported on the bottom 8 of the expansion channels.
[0034] The gel layer 2, after a film produced together with it has
been pulled off, can be bonded to the polyurethane foam layer 6. As
an alternative, the polyurethane foam layer could also be bonded to
the supports of the gel layer by an applied adhesive.
[0035] In all of the embodiments, the upper covering 7 is a spacer
knit which consists of two spacer textile surfaces connected to
each other by spacer threads.
[0036] The essential advantages of the shaped body according to the
invention are to be found in the increased seating comfort with
reduced overall height, the favorable ventilation properties, the
good distribution of pressure, a soft behavior when sat on and in
the reduced weight in comparison with a pure gel seat.
* * * * *