US007815827B2
`
`(12) United States Patent
`Cruz
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,815,827 B2
`Oct. 19, 2010
`
`(54) METHOD OF PRODUCING SLABS OF
`ARTIFICIAL STONE AND POLYMERISABLE
`RESN HAVING AVENED EFFECT BY
`MEANS OF VIBRO-COMPRESSION UNDER
`VACUUM
`
`(75) Inventor: Juan Cruz, Macael (ES)
`
`(73) Assignee: Cosentino, S.A., Macael (ES)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.:
`(22) PCT Filed:
`(86). PCT No.:
`
`11/917,548
`Jun. 15, 2005
`PCT/ES2005/000339
`
`S371 (c)(1),
`(2), (4) Date:
`
`Aug. 18, 2008
`
`(87) PCT Pub. No.: WO2006/134179
`PCT Pub. Date: Dec. 21, 2006
`
`(65)
`
`Prior Publication Data
`US 2008/0315448A1
`Dec. 25, 2008
`
`(51) Int. Cl.
`(2006.01)
`B29C 4/22
`(52) U.S. Cl. .............................. 264/77; 264/71; 264/74
`(58) Field of Classification Search ................... 264/71,
`264/74, 77
`See application file for complete search history.
`
`
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`6,773,641 B1
`8/2004 Toncelli....................... 264.71
`
`EP
`EP
`ES
`GB
`
`FOREIGN PATENT DOCUMENTS
`O511545
`11, 1992
`1005967
`6, 2000
`21873.13
`6, 2003
`2233640
`1, 1991
`
`OTHER PUBLICATIONS
`English translation of ES 2187313, Martos, Jun. 1, 2003.*
`* cited by examiner
`Primary Examiner Eric Hug
`Assistant Examiner Jacob Thomas Minskey
`(74) Attorney, Agent, or Firm Sughrue Mion, PLLC
`
`(57)
`
`ABSTRACT
`
`The invention relates to a process for manufacturing artificial
`stone boards with polymerizable resins with a “veined effect”
`by means of the vibro-compaction under vacuum system
`comprising a first grinding phase of the different materials
`forming the filler, a second phase containing a resin with the
`catalyst and optionally a third phase consisting of the mixing
`of the two previous phases until the homogenization of the
`materials with the resin, a fourth phase of moulding and
`compaction of the obtained paste by vibro-compression
`under vacuum, a fifth hardening phase by polymerization of
`the resin by means of heating and a last cooling, cutting and
`polishing phase.
`13 Claims, 1 Drawing Sheet
`
`

`

`U.S. Patent
`
`Oct. 19, 2010
`
`US 7,815,827 B2
`
`FIG.
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`FIGURE A
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`FIGURE B
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`US 7,815,827 B2
`
`1.
`METHOD OF PRODUCING SLABS OF
`ARTIFICIAL STONE AND POLYMERISABLE
`RESIN HAVING AVENED EFFECT BY
`MEANS OF VIBRO-COMPRESSION UNDER
`VACUUM
`
`2
`Subsequently homogenizing the entire filler until a more or
`less uniform colour is obtained. Nevertheless, in many cases
`it is desirable to obtain a board with different colours which
`will form well defined veins imitating natural Stones, i.e. a
`“veined effect.
`Two methods have been described for obtaining the type of
`board mentioned with veins of a colour different from the
`base. The oldest one is described in patent application EP 0
`970 790 (Luca Toncelli, Jan. 12, 2000) and is based on the use
`of a machine, object of said patent, which first produces
`cavities in the surface of the mixture which will form the
`board and subsequently fills said cavities with the desired
`colouring. The most modern method is described in patent
`application WO 03/027042 (Luca Toncelli, Apr. 3, 2003)
`comprising two alternatives depending on whether the bind
`ing product forming the board is of the “cement' type or the
`"polymerizable resin' type, the powdered pigment being
`used in the first case and pigment in liquid form in the second
`case which is the one most closely related to the present
`invention. Once the base mixture formed by a granulated
`material and an aggregate has been made, it is deposited on a
`Support and the solution containing the pigment is sprayed on
`the Surface with a nozzle in a localized and random manner So
`that patches or blotches of another colour are produced with
`out producing pigment agglomerations. Then, the mixture is
`subjected to the compaction phase with vibration under
`vacuum and Subsequently to the hardening, cooling, cutting
`and polishing phase. Another variant of the method consists
`of the surface of the mixture being treated, before or after
`adding the Solution with the pigment, with an instrument Such
`as a rake conveying an undulating movement to the Surface of
`the mixture such that the colouring solution is distributed
`more unequally. The result of this treatment after adding the
`solution with the pigment is that the patches or blotches of
`pigment deposited in the Surface are distributed acquiring the
`desired veined effect.
`However, there is not a continuity in the veined effect in all
`the depth of the board with the mentioned methods, i.e. the
`veining does not reach the lowerface, nor the edges, which is
`noticed when the sides are polished, it being desirable some
`times to obtain aboard in which the veined effect exists in all
`its dimensions so that it is visible both on the upper and lower
`Surfaces and in the sides after cutting and polishing the board,
`Such as for example in its use in decoration or staircases.
`Therefore, the object of the present invention is a process
`for manufacturing artificial stone boards especially Suitable
`for decoration, staircases or situations in which a veined
`effect is needed in the six surfaces, the two upper and lower
`faces and the four sides of said boards, comprising a grinding
`phase of the different materials forming the filler with varied
`granulometry, another phase containing the resin with the
`catalyst and optionally the colouring, the mixing of said
`phases until the homogenization of the materials with the
`resin, a moulding and compaction phase of the obtained paste
`by vibro-compression under vacuum, and a hardening phase
`by polymerization of the resin by means of heating, ending
`with a cooling, cutting and polishing phase, said boards being
`obtained with a veined effect due to the addition of a colour
`ing, either during the mixing phase in upper mixers or inside
`the homogenization ring at the same time that the material
`falls from the upper mixers or onto the belt leading to the
`distributor before falling to the distributor or inside the dis
`tributor before distributing the material in the mould in order
`to pass to the vibro-compression under vacuum phase. Such
`that the veined effect is observed in the final product on all the
`faces of the board even with continuity of the vein in the sides
`thereof.
`
`CROSS-REFERENCE TO RELATED
`APPLICATION
`
`This application is a 371 of PCT/ES2005/000339, filed
`Jun. 15, 2005; the disclosure of which is incorporated hereby
`by reference.
`A process for manufacturing artificial Stone boards with
`polymerizable resin with a veined effect by means of the
`Vibro-compression under vacuum system, similar to marbles,
`granite and other natural stones.
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`FIELD OF THE ART
`
`The present invention relates to a process for manufactur
`ing boards particularly with a veined effect.
`The process is one comprising agrinding phase of different
`materials with varied granulometry forming the filler, another
`phase containing the resin with the catalyst and optionally a
`colouring, the mixing of said phases until the homogenization
`of the materials with the resin, a moulding and compaction
`phase of the obtained paste by Vibro-compression under
`vacuum, and a hardening phase by polymerization of the resin
`by means of heating; ending with a cooling, cutting and
`polishing phase.
`
`STATE OF THE ART
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`The process marketed by Breton S.p.A (Italy) who devel
`oped the technology called “Breton Stone' is described in
`U.S. Pat. No. 4,698,010 (Marcello Toncelli, Oct. 6, 1987) in
`which aggregates of a material of variable particle size are
`mixed with a binder (organic or inorganic), and after said
`mixture has been homogenized it is discharged into a mould
`which, in turn, is transferred to the interior of a press where it
`is subjected to pressure and vibration under vacuum, the
`mixture being hardened and giving as a result blocks that can
`be cut into others of smaller dimensions.
`The product marketed by the authors of the present appli
`cation as SILESTONE, formed by an aggregate of natural
`quartz and pigmented crystal and bound with polyester-type
`resin, based on patent ES2 187313 of Jun. 1, 2003, describes
`a process for manufacturing artificial stone boards formed by
`a mixture of ground materials of different granulometry of
`silica, glass, granite, quartz, ferrosilicon and/or other materi
`als such as plastics, marbles and metals with liquid State
`polyester resins by vibro-compression under vacuum, heat
`ing, cooling and polishing, especially applicable for indoors
`and decoration.
`The present authors have also developed several boards
`similar to those described previously with respect to the filler
`materials but which only use liquid methacrylate resin as
`polymerizable resin (international patent application PCT/
`ES2005/000152 applied for on Mar. 22, 2005) with which
`boards are obtained that are much more resistant to ultraviolet
`light so they can be used in outdoor walls, staircases and
`decoration without the risk of wearing which can be caused
`by the continuous exposure to rays of Sunlight.
`In the mentioned cases, the different appearance of the
`obtained boards is obtained by varying the composition and
`granulometry of the products forming the filler, colouring
`different proportions of said filler with various colours and
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`The vein is based on being added in the areas of the process
`in which a Subsequent mixing is produced so that the vein is
`distributed throughout the entire board.
`
`US 7,815,827 B2
`
`EXPLANATION OF THE INVENTION
`
`The invention is a process for manufacturing artificial
`stone boards with a “veined effect” comprising the following
`steps:
`a) a grinding phase of the different materials of varied
`granulometry forming the filler;
`b) another phase containing the resin with the catalyst, the
`accelerator, the binder and optionally the colouring;
`c) mixing said phases until homogenization of the materi
`als with the resin, divided into two parts, mixing inside
`the upper mixers and mixing in the homogenization ring.
`d) transporting the homogenized mixture by means of a
`belt from which it falls to a distributor;
`e) discharging, from the distributor to the moulds, the
`amount of filler necessary for making a board according
`to the dimensions of the mould:
`f) protecting the mass formed by the boards with a paper
`Such as Kraft paper, or with an elastomer, such as for
`example a rubber layer, in order to pass to
`g) a moulding and pressing phase of the paste in each
`mould carried out by Vibro-compression under vacuum:
`h) a hardening phase by polymerization of the resin by
`means of heating:
`i) ending with a cooling, calibrating, polishing and cutting
`phase.
`The veined effect can be achieved in various ways: the
`colouring (either in solid or liquid form) can be incorporated
`in phase c) during the mixing of materials both in upper
`mixers and in the homogenization ring, d) in the journey of
`the mass towards the distributor or in the distributor itself, or
`also in phase e) when the mass is being distributed in the
`moulds, injecting the colouring in liquid form under pressure
`or in pigment form on the mass in any of the options. Subse
`quently, the pressing by vibro-compression under vacuum
`makes the vein be distributed not only on the surface but in the
`entire depth of the board.
`The invention also includes boards obtained by said pro
`CCSS,
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`DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 represents a veined board A obtained according to a
`process of the state of the art and another veined board B
`obtained according to the process of the present invention.
`
`DETAILED DESCRIPTION AND PREFERRED
`EMBODIMENT OF THE INVENTION
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`In order to obtain the veined boards object of the invention,
`materials of varied granulometry forming part of the filler,
`among others, marble, dolomite, opaque quartz, crystalline
`quartz, silica, glass, mirror, cristobalite, granite, feldspar,
`basalt, ferrosilicon etc. can be used, as long as they are com
`patible with the resin. Other filler materials can also be used,
`in the same granulometry as the materials indicated previ
`ously, Such as coloured plastics, metals, woods, graphite etc.
`The part of the filler used to obtain a specific decorative
`effect can be intimately mixed with the rest of the filler of
`similar granulometry or it can be placed on the Surface after
`wards.
`The mentioned materials form part of the composition with
`the following granulometry:
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`10% to 70% of the filler, of micronized or ground powder,
`with a granulometry comprised between 0.1 mm to 0.75
`mm,
`1% to 80% of the filler, of ground material with a granu
`lometry comprised between 0.76 mm and 1.20 mm; and
`optionally,
`10% to 50% of the filler, of ground material with a granu
`lometry comprised between 1.21 mm and 15 mm.
`The percentage of each granulometry depends on the use of
`the board to be obtained, said percentages varying according
`to the colour and visual effect desired.
`For the process, the starting material is prepared by grind
`ing it until the desired granulometry is obtained, the different
`percentages of each granulometry being mixed and then
`being loaded in the planetary mixers.
`Optionally, this filler can be distributed in different mixers
`Such that a solid colouring or pigment is added to each mixer.
`If the colouring is a liquid it is added to the resin phase.
`The resin phase is also prepared, preferably from unsatur
`ated polyester, although it can also be another type of poly
`merizable and thermosetting resins such as methacrylate,
`epoxy resins etc. The resin forms part of the total mixture in
`a percentage comprised between 6% and 30%. It will gener
`ally incorporate the catalyst, the accelerator, the binder and
`optionally the colouring.
`Method for Carrying Out the Veined Effect in Boards Made
`by Vibro-compression.
`The new method for carrying out the veined effect in
`boards is based on the use of Solid pigments and/or liquid
`colourings, independent of those used in the process of the
`mixers, so that these stand out on the already mixed mass of
`the mixers. These colourings can be inorganic, such as iron
`oxides, organic, phthalocyanines, either the Solid pigment,
`with granulometries less than 0.75 mm, or dissolved (liquids)
`in a carrier compatible with the resin to be used and which
`may be polymerizable, with the catalysts and accelerators of
`the base resin: styrene, methacrylate, Saturated or unsaturated
`resin, etc.
`Various paths can be followed in order to achieve the
`veined effect:
`a) Adding it to the upper mixers.
`b) Adding it to the homogenization ring at the same time
`that the mixed material falls from the upper mixers.
`c) Adding it to the belt leading to the distributor or in the
`distributor itself.
`Adding the colourings to make the veins dissolved in resin
`causes the mixing times in the mixers of the resin with the
`filler to vary considerably so that the mixture is packed as
`much as possible and the resin is well absorbed in the fillers,
`i.e. in normal mixing conditions, this lasts 10 minutes, with
`the new system the mixing time has to be extended to more
`than 15 minutes and even to 20 minutes. Although the mixing
`time is longer, the process is the same, giving as a result a
`homogeneous mixture, preferably between 1000 and 2000
`kg.
`For case a), add it to the upper mixers.
`Once the mixing has been carried out in the mixers and
`before discharging the mass to the homogenization ring, a
`new colouring, eitheras a pigment or as a liquid coloring, will
`be discharged very slowly onto the mass of each mixer and it
`will be stirred very slowly for 15 seconds so that the colour is
`dispersed on the surface of the mixture.
`In order to achieve this, a new system has to be assembled
`for weighing the colouring in the mixers and the conditions of
`the automatic mixing cycle have to be varied so that it con
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`US 7,815,827 B2
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`siders this new process of adding colouring after having
`added the coloured resin as usual.
`Subsequently, the discharging onto the homogenization
`ring will be carried out and the homogenization will be per
`formed by lowering the mixing fingers which are the mixing
`blades included in any mixer of this type.
`Once the movement in the circular mixer has been com
`pleted, the mass will be led to the distribution area and pressed
`in the same conditions mentioned previously.
`The following system for carrying out the veined effect is:
`The mixing conditions in the mixers are varied in the same
`way as indicated previously and instead of introducing the
`new colour in the mixers themselves, it is poured while the
`mass is discharged from the homogenization ring, when it
`falls to the belt feeding the distributor or in the distributor
`itself, before filling the mould, forming the layers of each
`colour; in this way, it is also obtained that the new colour is
`superficially distributed on the surface in which injectors of
`the paint spray gun type are projected on the entire discharged
`mass and it is then homogenized inside the distributor and
`then led towards the pressing area. The way to introduce this
`new colour, in the case of introducing colouring in liquid
`form, is to pump it towards the mass in the form of spray or in
`a continuous swaying jet while the mass falls to the belt
`leading to the distributor or when the mass is mixed inside the
`distributor.
`The colour is sprayed on the material which is being dis
`charged by means of a system similar to spray gun painting
`with compressed air. A bridge is assembled on the belt or on
`the distributor, such that the colouring spray gun can move
`longitudinally on the bridge and cover all the material in its
`spraying process. The bridge moves to distribute the colour
`ing simulating the effect of a hand that would support the gun
`and move it with a swaying motion. The material moves on
`the belt or inside the distributor at the same time as the
`spraying.
`Another system for carrying out the veined effect is:
`The mixing conditions in the mixers are varied in the same
`way as indicated previously and instead of introducing the
`new colour in the mixers themselves, it is poured while the
`mass is discharged in the homogenization ring, when it forms
`the layers of each colour; in this way, it is also obtained that
`the new colour is superficially distributed on the surface in
`which injectors of the paint spray gun type are projected on
`the entire discharged mass and it is then homogenized, low
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`ering the homogenization fingers which are the blades
`included in any normal mixer and which are usually used for
`mixing and is then led towards the distribution and pressing
`area. The way to introduce this new colour, in the case of
`introducing colouring in liquid form, is to pump it towards the
`mass in the form of spray or in a continuous Swaying jet while
`the mixer rotates and the masses of each main mixer are
`discharged.
`The colour is sprayed on the material which is being dis
`charged by means of a system similar to spray gun painting
`with compressed air. A bridge is assembled on the homogeni
`Zation mixer, so that the colouring spray gun can move lon
`gitudinally on the bridge and cover all the material in its
`spraying process. The bridge moves to distribute the colour
`ing simulating the effect of a hand that would support the gun
`and move it with a swaying motion. The material rotates
`inside the homogenization mixer and is being moved by the
`blades of this mixer at the same time as the spraying.
`The solution of the second coloring in liquid form added to
`the gun preferably has the following formulation:
`resin, 20% to 60% of the filler;
`colouring, 30% to 70% of the filler;
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`styrene, 1% to 20% of the filler;
`catalyst, 0.5% to 5% of the weight of the resin:
`accelerator, 0.05 to 0.5% of the weight of the resin; and
`binder, 0.5% to 5% of the weight of the resin.
`In the case of Solid pigment, the latter is introduced by
`weighing it in a suitable container and, by means of vibrating
`sieving, it will be added to the mass while the rotating mixer
`is discharged. In other words, the pigments are sprinkled in
`the rotating movement of the mass in the mixer and mixed
`with the homogenization blades.
`The final veined effect is obtained in the press, i.e. this new
`colour added to the mixture, since it is Superficially aggre
`gated on the colours of the masses (mixtures) made in the
`mixers and introduced in the entire mass, when the boards are
`pressed in the press, and due to the vibro-compression and
`expansion system of the board, the new colour expands
`throughout the entire pressed board, giving a fine and con
`tinuous vein in the entire contour of the board and even a large
`continuity of the vein in the edges.
`This obtained veined effect is independent of the system
`used as a protection of the boards before pressing, i.e. a paper
`or elastomer (rubber) etc. can be used as protection, consid
`erably improving other already patented methods because it
`achieves leading the vein to the ends of the board and through
`out the entire material, therefore, the vein in the board is
`available in all its surfaces and with the same features, favour
`ing two-face polishing and the polishing of the edges.
`The mixture thus obtained is transported by means of a belt
`and is taken to a distributor to make the boards. These are
`formed when the mass falls on the moulds which will have the
`dimensions which are desired for the boards. Generally, the
`boards will be rectangles from 50 cmx50 cm to 140 cmx310
`cm with thicknesses comprised between 0.5 cm and 8 cm, the
`preferred size being those of 140 cmx310 cm and a thickness
`of 2 cm.
`Subsequently, the mould with the load is protected with
`paper or rubber. Having protected and coupled the mixture in
`the mould, it is led to a vibro-compaction under vacuum press
`responsible for compressing the material and compacting it
`for which it first carries out the vacuum by removing the air
`and then presses the material by vibro-compression with a
`power of 6 kg/cm, the whole process lasting 2 to 3 minutes.
`The pressed board is led to an oven at a temperature
`between 80°C. and 110°C. for the polymerization of the resin
`providing the board with hardness. The time that each board
`remains in the oven is 30 to 60 minutes.
`Once it is out of the oven, the board is left to cool for
`approximately 24 hours at room temperature, later giving it
`the treatment which would be given to a conventional stone of
`marble, granite, etc., i.e. it is calibrated, polished and cut.
`This obtained veined effect is independent of the system
`used as a protection of the boards before pressing, paper or
`rubber, improving the obtained board compared to those
`obtained by other methods of the state of the art, because it
`achieves leading the vein to the ends of the board and through
`out the entire material, therefore, the vein in the board is
`visible in all its surfaces and has the same features, favouring
`two-face polishing and the polishing of the edges, unlike the
`other methods in which the colouring is sprayed on the Sur
`face of the mass of the board after the distributor when the
`product is not mixed again, with which once pressed, the paint
`penetrates 2 or 3 mm of the surface but does not reach the
`lower face therefore, the polishing offers different faces
`because the vein has not reached the lower face. The same
`occurs with the edges; since a rake-type device is used to stir
`the blotches of colouring placed in the Surface, this rake does
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`US 7,815,827 B2
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`7
`not reach the edges completely, therefore, they do not show
`the veined effect either when polished.
`These boards with a “veined effect” can be used both
`indoors and outdoors in floors, countertops, facades, stair
`Cases, etc.
`The invention claimed is:
`1. A process for manufacturing artificial stone slabs having
`a veined effect comprising the following steps:
`(a) grinding different materials of varied granulometry so
`as to form a filler;
`(b) obtaining a composition comprising a polymerizable
`and thermosetting resin;
`(c) mixing the filler of step (a) with the composition of step
`(b) So as to obtain a homogeneous mixture;
`(d) transporting the homogeneous mixture of step (c) by
`means of a belt to a distributor;
`(e) discharging, from the distributor to a mould, an amount
`of said mixture necessary for making a slab according to
`the dimensions of the mould;
`(f) protecting the mixture with one of a paper and an elas
`tomer,
`(g) moulding and pressing the mixture in each mould by
`compaction using vibro-compression under vacuum:
`(h) hardening, by polymerizing the resin in the resulting
`molded and pressed mixture of step (g) by means of
`heating in an oven;
`(i) cooling, calibrating, polishing and cutting said slab;
`wherein a coloring agent is incorporated in step (c) during
`mixing; during transporting in Step (d) or in the distribu
`tor itself, or during step (e); and said coloring agent is
`incorporated by injecting in liquid form under pressure,
`such that the obtained slab has veins of said coloring
`agent distributed throughout the slab such that the vein
`would be visible throughout a cross-section of the slab;
`and
`wherein the mixing step (c) is of a duration so as to cause
`the filler to absorb the resin, and further, after incorpo
`ration of the coloring agent and the vibrocompression
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`process, results in the obtained slab having veins of said
`coloring agent distributed throughout the slab Such that
`the vein would be visible throughout a cross-section of
`the slab.
`2. The process according to claim 1, wherein the coloring
`agent is a Solid pigment.
`3. The process according to claim 2, wherein the coloring
`agent is a Solid pigment having a granulometry of less than 0.7
`.
`4. The process according to claim 1, wherein the coloring
`agent is a liquid coloring agent or a dissolved solid pigment
`forming a liquid Solution.
`5. The according to claim 4, wherein the coloring agent is
`incorporated by means of an arm which sprays such onto the
`mixture.
`6. The process according to claim 4, wherein the coloring
`agent is dissolved in the polymerizable and thermosetting
`resin of step (b).
`7. The process according to claim 4, wherein the coloring
`agent is dissolved in a monomer compatible with the poly
`merizable and thermosetting resin of step (b), incorporating
`the accelerator, catalyst and binder as in step (b).
`8. The process according to claim 1, wherein the mixture is
`protected with Kraft paper or a rubber layer before being
`pressed.
`9. A slab obtained by the process according to claim 1,
`wherein said slab has a veined effect in all faces of the slab.
`10. The process according to claim 1, wherein the compo
`sition further comprises at least one of a catalyst, an accel
`erator, a binder and a coloring agent.
`11. The process according to claim 1, wherein the heating
`is performed between 80° C. and 110° C.
`12. The process according to claim 1, wherein mixing step
`(c) has a duration of at least 15 minutes.
`13. The process according to claim 1, wherein the vibro
`compression step presses the material with a power of 6
`kg/cm, for a duration of 2 to 3 minutes.
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