U.S. patent application number 09/835261 was filed with the patent office on 2002-01-17 for elastomer floor covering and method for its manufacture.
Invention is credited to Graab, Gerhard, Heckel, Klaus, Kuhl, Hans-Michael.
Application Number | 20020006499 09/835261 |
Document ID | / |
Family ID | 7873988 |
Filed Date | 2002-01-17 |
United States Patent
Application |
20020006499 |
Kind Code |
A1 |
Kuhl, Hans-Michael ; et
al. |
January 17, 2002 |
Elastomer floor covering and method for its manufacture
Abstract
A homogeneous floor covering composed of elastomer, varicolored
granular particles contains 3 to 20 percent by weight of a
copolymer of ethylene, including at least one comonomer of vinyl
esters of saturated carboxylic acids having up to 4 C-atoms in the
acid group, or including at least one unsaturated mono- or
dicarboxylic acid, or including at least one ester of unsaturated
mono- or dicarboxylic acids having up to 8 C-atoms in the alcohol
portion. In this context, the ethylene content of the copolymer is
40 to 95% percent by weight, the rest is comonomer, and the
melt-flow index of the copolymer must lie between 0.1 and 50. A
corresponding manufacturing process is specified.
Inventors: |
Kuhl, Hans-Michael;
(Hirschberg, DE) ; Graab, Gerhard; (Mannheim,
DE) ; Heckel, Klaus; (Gorxheimertal, DE) |
Correspondence
Address: |
KENYON & KENYON
One Broadway
New York
NY
10004
US
|
Family ID: |
7873988 |
Appl. No.: |
09/835261 |
Filed: |
April 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09835261 |
Apr 12, 2001 |
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09344975 |
Jun 28, 1999 |
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6251321 |
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Current U.S.
Class: |
428/195.1 ;
428/212 |
Current CPC
Class: |
D06N 3/10 20130101; B29C
43/30 20130101; C08L 53/02 20130101; D06N 3/04 20130101; Y10T
428/24802 20150115; C08L 23/0846 20130101; C08L 2666/02 20130101;
Y10T 428/24942 20150115; C08L 53/02 20130101 |
Class at
Publication: |
428/195 ;
428/212 |
International
Class: |
B32B 003/00; B32B
027/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 14, 1998 |
DE |
DE P 19831509.0 |
Claims
What is claimed is:
1. A homogeneous floor covering compromising a cross-linkable,
elastomer material, having a multicolored, directionless pattern,
and a thickness of 1.5 to 3.5 mm, characterized in that the floor
covering, in the case of widths of 1 m to 2 m, has no change in
thickness exceeding +5% over its entire width, that the floor
covering has a minimum elongation of 60% according to DIN 53 504
(tensile test), and that it contains 3 to 20 percent by weight,
with respect to its total weight, of a copolymer of ethylene
including at least one comonomer of vinyl esters of saturated
carboxylic acids having up to 4 C-atoms in the acid group,
unsaturated mono- or dicarboxylic acids, esters of unsaturated
mono- or dicarboxylic acids having up to 8 C-atoms in the alcohol
portion, or .alpha.-olefins having 4 to 10 C-atoms, the ethylene
content of the copolymer being 40 to 95 percent by weight, the
comonomer content 5 to 60 percent by weight, and the melt-flow
index of the copolymer lying between 0.1 and 50.
2. The floor covering according to claim 1, wherein it contains 3
to 10 percent by weight of a copolymer.
3. The floor covering according to claim 1, wherein the granular
particles forming it have a single color in and of themselves.
4. The floor covering according to claim 2, wherein the granular
particles forming it have a single color in and of themselves.
5. The floor covering according to claim 1, wherein the granular
particles forming it have a colored pattern in and of
themselves.
6. The floor covering according to claim 2, wherein the granular
particles forming it have a colored pattern in and of
themselves.
7. A process for manufacturing a homogeneous floor covering of
cross-linkable, elastomer material, having a multicolored,
directionless pattern, a thickness of 1.5 to 3.5 mm and a width of
1 to 2 m, comprising producing granular particles existing in at
least two colors which differ from each other, from correspondingly
varicolored rubber mixtures produced independently of each other,
which are formed into strands using extruding machines, and
subsequently granulated into grain sizes of up to 3.0 mm; further
comprising the subsequent spreading of the granular particles on a
band-shaped, horizontally moving carrier, the compression and
vulcanization in a band molding press appropriate for the width of
the floor covering to be produced, at 160 to 180.degree. C. and at
a pressure of 3 to 10 N/mm.sup.2, and the subsequent polishing of
the surface forming the back side of the resulting web, wherein,
with respect to the total weight of all materials to be processed,
3 to 20 percent by weight of a copolymer of ethylene including at
least one comonomer, are mixed with the unvulcanized rubber
mixtures prior to their processing, the comonomer selected from the
group consisting of vinyl esters of saturated carboxylic acids
having up to 4 C-atoms in the acid group, unsaturated mono- or
dicarboxylic acids, esters of unsaturated mono- or dicarboxylic
acids having up to 8 C-atoms in the alcohol portion, and
.alpha.-olefins having 4 to 10 C-atoms, the ethylene content of the
copolymer being 40 to 95% percent by weight, the comonomer content
5 to 60 percent by weight, and the melt-flow index of the copolymer
lying between 0.1 and 50.
8. The process according to claim 7, wherein the weight percent of
copolymer is from 3 to 10.
9. The process according to claim 7, wherein granular particles
having a single color in and of themselves are produced and
used.
10. The process according to claim 8, wherein granular particles
having a single color in and of themselves are produced and
used.
11. The process according to claim 7, wherein granular particles
having a colored pattern in and of themselves are produced and
used.
12. The process according to claim 8, wherein granular particles
having a colored pattern in and of themselves are produced and
used.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an elastomer floor
covering. In particular, it relates to a homogeneous floor covering
of cross-linkable, elastomer material, having a directionless
pattern. A manufacturing process is also specified.
DESCRIPTION OF RELATED ART
[0002] European Patent A1 0 512 197 describes a floor covering of
the species, which is completely free of trapped air. The
manufacturing process is characterized in that, using a short
screw-type extruding machine including an attached perforated disk,
moldings having a size of 1 to 2 mm are continuously produced from
two or more varicolored, vulcanizable elastomer materials by
knocking off the emerging strands.
[0003] These moldings are passed through the gap of a two-roll
calender under a constant line pressure, the calender having
horizontally arranged rolls capable of being heated and cooled, a
homogeneous band being formed, which is vulcanized to form a
ready-made floor covering. To keep the line of pressure in the roll
nip as narrow as possible, a very low diameter/length ratio of
1:3.5 is preferred.
[0004] Using this process, floor coverings having a thickness of
approximately 2 mm can only be made in a limited width. In the
recommended diameter/length ratio of 1:3.5 for the calender, the
width of 1250 mm specified in the citation already requires a roll
diameter of 370 mm, given a length of 1300 mm. It has been found
that, in the manufacture of a 2 mm thick web, such slim rolls bend
away from each other in the middle of their axial extent by up to 1
mm and more. This effect intensifies considerably in response to an
increasing roll length, or web width, given a constant roll
diameter.
[0005] Consequently, the resulting web has a thickness of over 2.8
mm in its corresponding central surface area, and only the areas
near the edges have the desired calibration thickness of 2 mm.
[0006] An alternative to this line pressing process is to process
the material flat, for example, in a band molding press. European
Patent B1 0 046 526 describes such a process, which has the
advantage of an exactly equal pressing pressure in all surface
areas, and consequently, the possibility of manufacturing webs
having a uniform thickness.
[0007] In the process, a raw material layer of spread-out
thermoplastic particles is continuously compressed flat at
160.degree. C. to 220.degree. C. and welded together, and is
subsequently cooled down and pressed off at an unchanging pressure.
In this context, the web width is dependent only on the width of
the molding press.
[0008] If one tries to apply this method--described for
thermoplastic materials--to vulcanizable, elastomer materials for
floor coverings, webs are produced whose elongation at break,
according to DIN 53 504, has values of only 20 to 30%. Such low
elongations, however, are inadequate for floor coverings since they
must very often be laid on uneven sub-floors and against edge
areas, the floor coverings having to adapt to uneven areas and
imprecise fits through certain elongation properties so as to avoid
destruction.
[0009] However, elastomer materials are always to be given
preference since, in contrast to thermoplastic materials, they
exhibit a resistance to cigarette burns.
SUMMARY OF THE INVENTION
[0010] The object of the present invention is to specify a
homogeneous floor covering of cross-linkable, elastomer material,
having a multicolored, directionless pattern, which
[0011] in the case of widths of 1 m to 2 m, exhibits only an
insignificant change in thickness (maximally 5%) over its entire
surface,
[0012] has a thickness of 1.5 to 3.5 mm,
[0013] minimum elongation of 60% according to DIN 53 504.
[0014] A further object of the present invention is to specify a
continuous manufacturing process, making it possible to produce
such a floor covering economically.
[0015] The property "homogeneous" is defined for floor coverings
according to DIN 16 850: "Homogeneous elastomer coverings, composed
of a layer or a plurality of layers of equal composition. They have
a multicolored, continuous pattern, or a continuous, uniform
color."
[0016] This objective is achieved according to the present
invention by using a homogeneous floor covering of cross-linkable,
elastomer material, having a multicolored, directionless pattern,
and having the properties required by the object of the invention,
the floor covering, with respect to its total weight, containing 3
to 20 percent by weight of a copolymer of ethylene including at
least one comonomer belonging to the group of
[0017] vinyl esters of saturated carboxylic acids having up to 4
C-atoms in the acid group,
[0018] unsaturated mono- or dicarboxylic acids,
[0019] esters of unsaturated mono- or dicarboxylic acids having up
to 8 C-atoms in the alcohol portion,
[0020] .alpha.-olefins having 4 to 10 C-atoms.
[0021] In this context, the ethylene content of the copolymer must
be 40 to 95 percent by weight, the comonomer content 5 to 60
percent by weight. The melt-flow index of the copolymer must lie
between 0.1 and 50.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Copolymer proportions of 3 to 10 percent by weight turned
out to be particularly advantageous, compared to ones having higher
copolymer proportions, since then, due to the slight adhesive
quality, the mixture can be processed more favorably on the rolls.
In addition, the properties of the ready-made floor covering are
not substantially affected; copolymer proportions higher than 10
percent by weight can cause, for example, a worsening of the fire
resistance.
[0023] The floor covering can be essentially in two
embodiments:
[0024] In the one case, the granular particles forming it have a
single color in and of themselves; in the other case, they have a
colored pattern in and of themselves. The visual effect of the
surface is a little quieter in the latter variant while the
alternative conveys a livelier picture of the surface.
[0025] The manufacture of the floor covering according to the
present invention is carried out in a generally known manner in
that, first of all, granular material particles are produced from
unvulcanized elastomer material, the particles differing from each
other in color, and also being able to have non-homogeneous colors
in and of themselves. To this end, corresponding, varicolored
rubber mixtures are produced independently of each other, formed
into strands using extruding machines, and subsequently granulated
into grain sizes of up to 3.0 mm.
[0026] Then, analogously to European Patent B1 0 046 526, at least
two granular materials differing in color are spread on a
band-shaped, horizontally moving carrier. Such carriers can be
composed of release paper, steel band, or polytetrafluoroethylene
band, and must never adhere to the particles.
[0027] The compressing and vulcanization are carried out in a band
molding press appropriate for the width of the floor covering to be
produced, at 160 to 180.degree. C. and at a pressure of 3 to 30
N/mm.sup.2. Subsequently, the reverse side of the resulting web is
polished for the sake of improving the gluing capability.
[0028] Essential to the present invention of this process is that,
with respect to the total weight of the materials to be processed,
3 to 20 percent by weight of a copolymer of ethylene including at
least one comonomer are mixed with the unvulcanized rubber mixtures
prior to their processing.
[0029] Suitable comonomers include
[0030] vinyl esters of saturated carboxylic acids having up to 4
C-atoms in the acid group,
[0031] unsaturated mono- or dicarboxylic acids
[0032] esters of unsaturated mono- or dicarboxylic acids having up
to 8 C-atoms in the alcohol portion,
[0033] .alpha.-olefins having 4 to 10 C-atoms.
[0034] The ethylene content of the copolymer is 40 to 95 percent by
weight, the rest is comonomer, and the melt-flow index of the
copolymer must lie between 0.1 and 50.
[0035] Using copolymer proportions of 3 to 10 percent by weight
reduces the adhesive quality of the material during processing, and
improves the fire resistance and mechanical resilience of the
finished product.
[0036] With regard to the alternatives of creating the floor
covering from granular material particles which have either a
single color in and of themselves or a multicolored pattern in and
of themselves, corresponding procedures are known to a worker
skilled in the art. The making of multicolored patterns is
described, for example, in European Patent A1 0 512 197. During the
extrusion of the material to be reduced to granular particles, care
must be taken that the varicolored strips of vulcanized rubber are
not subjected to an intermixing of colors.
[0037] A suitable device for this is, for example, a conventional
short screw-type extruding machine, which is operated at 60 to
100.degree. C. In a specific embodiment, the resulting strands pass
through a perforated disk having bores of a diameter of 3 to 5 mm;
the strands are knocked off every 1 to 2 mm. Alternatively, for
this purpose, the plasticized mass is permitted to emerge from a
slot nozzle of an extrusion head, and the cooled mass is granulated
using cutting mills.
[0038] The quantity of copolymer contained in the floor covering
according to the present invention, i.e., mixed with the elastomer
mass prior to processing, is usefully given a lower limit of 3
percent by weight, since smaller proportions cannot have any
essential effect on the extensibility [elasticity] any more. The
upper limit is 20 percent by weight since higher values would
change the Shore hardness of the elastomer material too much; the
Shore hardness of the ready-made floor covering should as far as
possible be the same as that of the starting mixture.
EXAMPLE
[0039] Using advantageous embodiments, the achievement of the
object according to the present invention is explained by the
following examples on the basis of comparable measuring results.
All examples start from unvulcanized elastomer material composed as
follows:
1 Styrene-butadiene rubber having a 100 parts styrene content of 23
per cent by weight Styrene-butadiene copolymer 20 parts having a
styrene content of 85 per cent by weight Precipitated silicic acid
40 parts Kaolin 70 parts Precipitated chalk 30 parts
Coumarone-indene resin 15 parts Zinc oxide 5 parts Stearic acid 1.5
parts Sulphuric acid 2.5 parts Polyethylene glycol 3 parts
Cyclohexyl benzothiazole suiphene amide 2.7 parts
Tetramethylthiuramdisulfide 0.5 parts Pigments as desired
[0040] The particle-size distribution of the granular material
is
2 >2.5 mm 1% >2.0 mm 33% >1.4 mm 55% >1.0 mm 25%
>0.71 mm 6%
[0041] The starting mixture has the following parameters:
3TABLE 1 Starting mixture As roll compound As spread layer
Elongation % Shore Hardness Elongation % Shore Hardness 120 92 30
92
[0042] Table 1 reveals how the above characterized elastomer
granular material, after the processing in a two-roll calender
according to the related art, has an excellent elongation of 120%,
while the same material passing through a band molding press as a
spread layer has an elongation of only 30%, which is inadequate to
meet the technical requirements for laying floor coverings.
[0043] Table 2 specifies the variants of processing the starting
mixture via a band molding press. Here, as in Table 1, the
following parameters apply:
4 Width of the band molding press 1500 mm Width of the floor
covering to be produced 1300 mm Pressing pressure 30 N/mm.sup.2
Pressing temperature 180.degree. C. Vulcanization time 4 min
[0044] As Table 2 clearly reveals, different quantities of a
copolymer of ethylene including at least one comonomer (1st column)
were added to the mixture. In the following columns of Table 2, the
comonomer contents are assigned to these copolymer quantities.
[0045] It turns out that the copolymers composed and added
according to the present invention produce minimum elongations of
60% according to DIN 53 504 in the floor covering, while the Shore
hardnesses remain nearly unchanged with respect to the starting
mixture.
5TABLE 2 Copolymer 18% VA EVA 50% VA EEA E-octene addition Shore
28% VA Shore 18% EA 14% octene in kg Elong. % Hardness Elong. %
Shore Hardness Elong. % Hardness Elong. % Shore Hardness Elong. %
Shore Hardness 10 35 93 40 92 60 91 -- -- -- -- 15 -- -- 40 92 --
-- -- -- -- -- 20 55 92 70 91 160 89 45 92 40 92 30 70 91 90 90 --
-- 60 91 60 90
[0046] As Table 2 clearly reveals, different quantities of a
copolymer of ethylene including at least one comonomer (1st column)
were added to the mixture. In the following columns of Table 2, the
comonomer contents are assigned to these copolymer quantities.
[0047] It turns out that the copolymers composed and added
according to the present invention produce minimum elongations of
60% according to DIN 53 504 in the floor covering, while the Shore
hardnesses remain nearly unchanged with respect to the starting
mixture.
[0048] When using copolymers including vinyl acetate as comonomer,
the rule applies that low vinyl acetate contents require a greater
quantity of copolymer to be added to the mixture (over 20 kg, Table
2). Adding these increased quantities, however, does not result in
a noticeable reduction of the Shore-A hardness of the product. Nor
is the mechanical resilience negatively affected in the
process.
[0049] However, if the vinyl acetate content in the copolymer is
increased to, for example, 28 percent by weight, the desired
tensile strength is already reached at a copolymer addition of 20
kg, as shown in Table 2. In the process, the Shore-A hardness is
not disadvantageously reduced.
[0050] In the case of even higher vinyl acetate contents (50
percent by weight), a marked softening of the elastomer mixture can
be detected even when small quantities of copolymer (10 kg) are
added.
[0051] Copolymers behave similarly in conjunction with other
comonomers; examples are an ethylene-ethyl acrylate copolymer
having an ethyl acrylate content of 18 percent by weight as well as
an ethylene-octene copolymer having an octene content of 14 percent
by weight. Both copolymers can be obtained on the market. In the
case of the comparatively low comonomer proportions, copolymer
additions of over 20 kg are necessary to reach the desired minimum
elongation. The achieved Shore-A hardnesses, however, lie within
the range which can still be tolerated, but at its margin.
* * * * *