Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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THIS I~VENTION relates to a ~lexible sheet or
~trip which may be used to provide a decorative cladding
on walls, furniture and the like, and to a proce~s for
preparing the flexible sheet or strip.
Decorative cladding materials comprising
thermoset synthetic resin compositions and paper web
materials are known and include, for example, decorative
plastics laminates having a core comprising a plurality
of phenol-formaldehyde resin-impregnated paper sheets and
a decorative ~urface comprising a decorative paper sheet
impregnated with a thermosetting amino-resin (especially
a melamine-formaldehyde resin) with or without a further
thermosetting amino-resin impregnated overlay paper sheet.
$hese laminates (referred to herein as "standard laminate~")
possess many of the properties desired in decorative
cladding materials, Mowever, these "standard" laminates
do not possess sufficient flexibility to be capable of
being bent about small radii without crazing or cracking
and to overcome this disadvantage a further type o*
laminate commonly referred to as a "post-forming" laminate
has been developed and is known in the art. "Post-forming"
laminates are substantially similar to standard laminates
with regard to their production and construction and in the
majority of their properties, but, by suitable variation
o* the components u~ed in their manufacture and/or in the
manufacturing conditions employed, they have the capability
of being deformed about small radii after their manufacture,
by means of suitable treatments,
The decorative cladding materials o* the types
exempli~ied ab~ve are customarily produced by di~continuous
processes utilising elevated temperatures and high pre3sures
in order to cure substantially the resins and consolidate
the assembly,
Decorative cladding materials should posse~s a
number of desirable properties such as to en3ure their
satisfactory use in the variety of cladding purposes to
which they are commonly put. For example, they ~hould -
S a) possess sufficient flexibility to enable them to
be used in applications requiring the material to
be bent about small radii without special treatmcnt~
b) have adeguate abrasion-resistance so that the cla~
surface has satisfactory wear characteristics;
c) have adequate hardness so as to be satis~actorily
resistant to 3cratching and scuffing;
d) be available in forms which enable areas to be clad
with a minimum number of joins in the cladding
material;
e) exhibit satisfactory dimensional stability;
f) be capable of being handled and worked without
suffering damage; and
g) be capable o~ being fixed to the substrate easily and
cheaply
Decorative plastics ~minates, made by discontinuous
high pre~sure processes, have found wide acceptance a~
decorative cladding materials but such laminate~ generally
lack flexibility and commonly possess properties to a
degree in excess of those required for satisfactory
performance in a number of cladding operations Further,
as such laminates are produced by the use of presses, their
sise is necessarily restricted by the maximum size of press-
plate that can be accommodated by the presses.
Flexible decorative cladding materials are also
known and are available in sheet or strip form. Further
such flexible cladding materials are commonly produced,
without the application of high pressure, in a continuous
manner, when the material comprises at~Qrmoplastic re3in~
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, However, such materials are often deficient in properties
such as abrasion- and scuff-resistance.
The invention provides flexible decorative
cladding sheets or strips having a wear surface comprising
a ~lexible thermoset ~ninoplast resin composition, and
produced without using a discontinuous high pressure
consolidation step.
The sheets or strips of the invention axe sheets
or strips capable of being bent about a radiu~ of 3 cm at
20C without cracking or being permanently deformed, and
characterised by comprising a decorative paper web
irr.pregnated with a thermoset aminoplast re~in impreg~ating
com~osition (a~ hereinafter defined)
the we~ having on one surface thereof a coating comprising
a thermoset arnino~last resin coating composition ~as
hereinafter defined).
The process is one for the preparation of a
decorati~e cladding sheet or strip capable o~ being bent
about a radius of 3 cm at 20~C without cracking or bei,ng
per~anently deformed, characterised by
a) impregnating a decorative paper web with a varni~h
comprising a thermosettabl~ aminopla~t r~sin impregn~tiny
composition (as hereinafter defined) and a volatile
solvent;
b) providing on the decorative surface of the impregnated
paper web a coating of a varnish comprising a thermo-
~ettable aminoplast resin coating,composition (a3 herein-
after de~ined) and a volatile solvent;
c) heating the coated web to rernove solvent and any other
3n volatile materials and to conver1- the thermosettable
com~ositions to the thermoset state.
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In a preferred process for preparing the cladding
~heet or strip, the paper web i~ i~pregnated with a
varnish comprising a thermo~ettable aminoplast resin
impregnating composition in a volatile solvent and the
impregnated web is then provided, without intermediate
drying, on one surface with a coating comprising a
thermosettab7e aminopla~t re~in coating compo~ition and
a volatile solvent, Thetreated web is then heated to
remove the solvent and other volatile materials and
convert the thermosettable compositions to the thenmoset
state. In a further preferred proce~, the impregnated web
is dried both before and after the coating step,
The decorative paper web ma~ be any ~uch web
suitable for impregnation and coating with aminoplast resin
composition~. It is preferred to employ those decorative
paper webs known for use a~ the decorative layer in
conventional plastics laminates. ~le web may be printed
with any de~ired pattern or legend or may be plain-coloured
and suitably ha~ a basis weight of 80 to 250, preferably
150 to 210 g/m2.
By the term "thermosettable aminoplast resin
impregnating composition" is meant any thermosettable
aminoplast resin impregnating composition known for use
as an impregnant in a paper web provided that 3uch compositions
can be cured to a thermoset resin which when used as an
impregnant~ constituting from 3~0 to 4~/O by weight o~ the
treated paper, in a decorative paper web having a ba3is
weight of 80 to 250 g/m2, gives an impregnated paper web
that may be bent a~out a radius of 3 cm at 20~C without
exhibiting cracking and/or permanent deformation. The
term "a thermo~et aminoplast resin impregnating composition~
refers to the corresponding thermoset composition
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Suitable compositions are known; examples are
melamine-, urea-, acetoguanamine- and benzoguanamine-
foxmaldehyde resins and mLxtures thereof, optionally in
conjunction with a plasticiser. Melamine-formaldehyde or
melzmine-urea-formaldehyde resin compositions are preferred;
the plasticiser is preferably a polyethylene glycol
composition, suitably used in an amount of 10~ to 35%,
especially about 20~, by weight of the resin solids in the
impregnating composition.
In the preferred proces~, the impregnation of
the paper web with a varnish cornprising a thermosettable
aminoplast resin composition may be carried out in any
suitable manner employing apparatus known for such use.
It i~ preferred to use a varnish comprising the aminoplast
resin composition dissolved or dispersed in an agueous
alcohol solvent
Irrespective of how it is performed, the impreg-
nation is suitably carried out so that after removal of
the solvent and other volatile materials, the r2sin content
of the impregnated web is 2~/o to 5~/0, preferably 30~ to 4~0,
by weight of the dried impregnated web.
By the term "thermosettable aminoplast resin
coatin~ composition" is meant any thermosettable aminoplast
composition known for use a~ a coating provided that such
compositions can be cured to a thermoset resin which will
adhere strongly to, or unite with, the flexible aminoplast
resin impregnated decorative paper web and possesses
adequate flexibility. The flexibility required of the
thermoset resin is such that when the cladding material
is bent around a small radius no cracking of the coating
layer occurs before cracking of the impregnated paper web.
The term "thermoset aminoplast resin coating composition"
refers to the oorresponding thermoset composition
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The preferred aminoplast resin coating composition
comprise tho~e commercially available compositions known
generally as aminoplast stoving finishe~; examples are condensates
of an alkylated urea and/or alkylated melamine and/or alkylated
acetoguanamine and/or alkylated benzoguanamine with formaldehyde in
conjunction with at least one alkyd resin, polyester resin,
epoxy resin or poly (unsaturated monomer) resin. More
preferably, there are used the aminoplast compositions
generally identified as alkyd modified aminoplast compositions
and more especially such compositions w~erein the ~mino-
plast component comprises an alkylated melamine-formaldehyde
and/or an al~lated urea-formaldehyde resin~ Such
compositions are commercially available in forms that in
the cured (stoved) state, exhibit surfaces de-cribed by the
terms "gloss", "se~i-matt" and "matt". Thus for any product
prepared by the invention the composition is so chosen that
the finished surface exhibits tnat degree of gloss desired,
In the preferred p.rocess, the coating of the
~mpregnated paper web may be performed in any suitable
manner, for example spray coating, curtain coating or roller
coating; it is preferred to employ a reverse-roll coating
technique and to apply th~ coatin~ cornpo~ition so as to
provide afte~ drying a coating weight o~ 20 to 60, preferably
25 t~ 50 9 g/m ,
After applying the coating composition, the
treated ~eb is heated by any suitahle means so that the
solvent and other volatile materials present are substantially
completely removed and the aminoplast re3in composition~ are
con~erted to the thermoset state ~e prefer to carry out
this heating by passing t'ne treated we~ through an oven,
operating at such a tem~erature, and the passage therethrough
beiny at such a rate, that the desired evapora~ion and
conversion occur.
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~he coated and impregnated web after the heat
treatment is co~led by any suitable means and is then
collected suitably ky roll take-up means.
Suitable cooling means include, for example,
an air blast or chill rollers If it is desired to
impart a non-planar sur~ace to the product, it i~ preferred
to employ chill-rollers and to pass the hot web emerging
from the heat treatment between chill rollers, at least
one of which ha~ a sur~ace complementary to that to be
provided on the surface of the cladding material.
The invention i5 illustrated by the following
Examples, wherein all parts and percentages are by weight,
EXAMPLE 1
A web (1.2 m. wide) of standard laminate
decorative paper having a basis weight of 150 g/m and
printed with a w~odgrain pattern was passed through an
impregnating bath containing a melamine-~ormaldehyde resin
camposition varnish. The composition of the varnish was:-
i) 10 parts of a thermosettable melamine-
fonmaldehyde resin having a melamine:form-
aldehyde ratio of 2.25 : 1
ii) 10 parts of a ~olvent comprising a water
and industrial methylated spirit mixture in
a ratio of 4
iii) 1 part of polyethylene ylycol plasticiser,
having a molecular weight o~ about 1000.
(The impregnation process was adjusted so that the
impregnated web had a resin content of 3~/o after dryingO)
The impregnated web was then (without
intermediate drying) coated with a colourless commercially
available alkyd-modified melamine-fonmaldehyde resin, by
means of a reverse roll technique, the coating process being
so adjusted a~ to provide a dry coating weight of about 40 g/m2.
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( me resin employed was supplied ~y ICI Limited under the
designation K105/2030 and was mixed with an activator,
K275~77, in accordance with the manufacturerls instruction ,
prior to use),
S The impregnated and coated web was then heated
by passage through a hot air oven at an air temperature
of 135-145C so that the solven~ and volatile material
were driven off and the thermosettable resin compositions
con~erted to the thermoset ~tate. The product emerging
from the oven was cooled ~y an air bla~t and wound upon
a reel,
The product thus produced exhibited sati~factory
abrasion- and scuff-resistance and could be bent about a
radius of less than 3 cm at 20~C without cracking or
permanent deformation.
EXAMPLE 2
A web (1,2 m, wide) of standard laminate plain
white decorative paper having a basi~ weight of 165 g/m2
was passed through an impregnating bath containing a
thermosettable melamine-~ormaldehyde resin composition
varnish. The composition of the varnish wa~:-
i) 10 parts of a thermo~ettable melamine-
~ormaldehyde resin having a melamine:
formaldehyde ratio of 2,0 1
ii) 10 parts of a solvent comprising a water and
indu~trial methylated spirit mixture in a
ratio of ll : 1
(The impregnation process was adjusted ~o that the
impregnated web had a re~inoo~tent of 35~ after drying),
The impregnated web was then (without
intermediate drying) coated with the colourles~ commercially
available alkyd-modified melamine-formaldehyde resin used in
Example 1, by mean~ of a reverse-roll technique, The coating
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proces~ was so adjusted as to provide a dry coating weight
of about 35 g/m2.
The impregnated and coated web was then heated-
by pas~age through a hot air oven at an air temperature
of 135C-145C xo that the qolvent and volatile material
was driven off and the thermosettable resin compo~itions
converted to the thermoset ~tate. The product emerging
from the oven was cooled and embossed by passage between a
pair of chill rollers, the roller in contact with the
coated surface bearing a non-planar pattern whereby a
complementary linen texture finish was imparted to the
product ~hQ cooled embossed material was then wound upon
a reel,
The decorative cladding strip or sheet may be
satisfactorily adhered to substrates using, for example,
techniques and adhe~ives known for cladding such substrates
with standard laminates. For example, a decorative faced
chip~oard may be prepared, by adhering the strip or
sheet to the substrate using a commercial urea-formaldehyde
adhe~ive employing a contact pressure of 3.5 kg/cm2 ~or
5 minutes at 160F.
The strip or sheet also finds utility as an edging
strip; quch edging strips are commonly employed to cover the
side edges of substrates wllose major surfaces have been
clad with sheets of standard laminates or other decorative
cladding materials. The edging strip may be prepared by
impregnating and coating the paper web with a thermo3ettable
aminoplast compo~ition and ~en subsequently ~litting same
to the deqired width either before or a~ter conversion of
the composition to the thermoset state.
If desired thicker products than can conveniently
be prepared from ~ingle paper webs may be produced by laminating
to the paper web, preferably in a continuous manner and
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prior to the application of the coating layer, a second
flexible web of any suitable material. Clearly the nature
of such a second we~ must be such as not to render a
material comprising sæme incapable of being bent about a
radius of 3 cm at 20C, Suitable webs include paper,
glass fibre and textile webs, optionally impregnated
and/or coated with flexible thermoplastic or thermoset
resin~.
If a second paper web is to be laminated to
the decorative paper web then this second web may be
impregnated with a similar resincomposition to that used
for the decorative web. Clearly when a second paper web
i~ en~loyed such i5 not necessarily a decorative paper web.
