JPH09209494A - Manufacture of reinforced stone material slab and reinforced stone material slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to reinforce bending resistance by providing a reinforcing material layer which buries a nonstranded glass thread into transparent curing resin resistant to an open air agent, on the front surface of a stone material slab which reinforces the rear surface. SOLUTION: The front surface 14 of a stone material slab 10, whose thickness is thin, such as marble or granite is reinforced with a mat 16 made of a glass thread and an epoxy resin layer 20. In the case when it is necessary to reinforce the rear surface more firmly, a groove or a cavity which houses a glass fiber strand, is provided on the rear surface 14 and filled with epoxy resin. Furthermore, the reinforcing layer provided on the front 12 of the stone material slab is arranged to contain a large number of non-stranded glass threads ranging from about 100 to 800g/cm<2> in the surface area of the slab in the form of a mat. Then, a protective reinforcing resin layer 26, which comprises epoxy resin or the like, is laminated on the front surface 12 where powder of silica rock or quart is filled up in this resin 26. This construction makes it possible to form a slab whose inner surface is reinforced so that resistance properties against bending in both positive and negative directions may be increased.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a reinforced stone slab and a reinforced stone slab obtained by the method. More specifically, the present invention relates to a method for manufacturing a stone slab that is thin and highly resistant to bending in both positive and negative directions, and a reinforced stone slab obtained by the method.

The description of the present specification is based on the priority of the present application, which is the basis of Italian patent application No. TV96A00000.
No. 8 (filed on January 29, 1996) based on the description of the specification of the Italian patent application, and the content of the specification of the Italian patent application is referred to in the present specification by referring to the number of the Italian patent application. Shall form part of

[0003]

BACKGROUND OF THE INVENTION These slabs are typically used for masonry construction, such as, for example, pavement cladding, building exterior cladding, and more generally mechanical properties and unique aesthetic effects. It is used as a covering material in applications where it is necessary to have both. As is well known, in the case of slab-like natural stone, the main goal in producing slabs has always, and still, without unacceptably diminishing their mechanical properties (for obvious reasons). (For) to make it as thin as possible. For thin slabs, an important issue in use is that they must be handled carefully to avoid breakage or breakage. Thus, what is needed is to avoid any situation of holding the slab in a cantilevered state, both during transportation and during handling of the slab, for example during a transfer operation before final installation.
This is because even if the vibration at the exposed end of the slab is small, it is inevitable that the damage will occur due to the vibration.

Marcello Toncel on July 15, 1995
European patent application No. 9520159 filed by Li
No. 0.7 describes a method for manufacturing a thin slab made of a stone material such as marble or granite, the back surface of which is in other words the surface of the invisible side is reinforced. This manufacturing method basically consists of applying a curable resin layer such as an epoxy resin to the above-mentioned back surface, that is, the invisible surface, and the resin layer has no twist. A linear, preferably matt, glass yarn reinforcement is incorporated with the resin to glass yarn mat weight ratio being maintained at a specified percentage.

As a modified example, cavities or grooves are formed on the back surface of the slab, and a linear reinforcing material preferably made of glass fiber in a strand form is put in these grooves and these are embedded with a resin layer. Is also possible.

To know more about how to carry out this method, the technical problems it solves and the properties of the resulting reinforced slabs, it is necessary to refer to the text of the aforementioned patent application.

Of particular note, the bending resistance of the stone slabs reinforced as described above is significantly increased. For example, when a granite slab having a thickness of 10 to 12 mm and a bending resistance of usually 150 kg / cm ² is reinforced with two glass yarn mats and an epoxy resin, the resulting composite slab (always has a total thickness of Of 10 mm) indicates a bending resistance of approximately 1350 kg / cm ² . However, in the case of facades for the exterior walls of buildings, further resistance issues especially related to the effects of outside air factors, especially wind effects, have to be taken into account.

The bending resistance is increased by the method of the aforementioned patent application with respect to its reinforcing side, while
Bending resistance on the visible side is 120 to 180k
It stays at the normal value of g / cm ² (depending on whether the material used is marble, granite or other natural stone).

When a building is exposed to wind of considerable force and velocity, localized decompression in the building's wind flow causes localized decompression that can cause some of the slabs to be destroyed with obvious defects. It acts on slabs that cover surfaces that are not directly exposed, especially on the slabs of the horizontal edge of the building.

On the other hand, regarding the surface forming the external surface of the slab, the means for improving the bending resistance is basically required to have the formal and aesthetic characteristics. , So far, unknown therefore, the only conventional solution for covering buildings installed in areas exposed to high winds is a stone slab of considerable thickness to compensate for the decrease in bending resistance. Was to use.

[0011]

Therefore, the main problems of the present invention are: (a) the thickness is thin, and (b) both sides are reinforced so that the resistance to bending in both positive and negative directions is increased,
(C) To produce a stone slab whose aesthetic properties have not changed for a long time.

[0012]

SUMMARY OF THE INVENTION The method according to the invention for achieving the said object is to strengthen the back surface, ie the non-appearance surface, of a stone slab in accordance with the method forming the subject of the aforementioned European patent application, while at the same time in the open air. Forming a reinforcing material layer on the front surface of the slab, that is, on the appearance surface, by embedding untwisted glass thread in a transparent curable resin that does not yellow by the chemical substance of 1. Is a method characterized by.

The expression "thin" means that the thickness is preferably 10 mm or less, but, of course, is not to be understood only in this limited sense.

[0014]

In a preferred embodiment of the invention, the reinforcement layer is used in such an amount that there is approximately 100 to 800 g, preferably 500 g of mat per surface area of a square meter slab. Other than that, it contains the same untwisted glass thread mat that was used to strengthen the backside.

With respect to the transparent curable resin, the best results are obtained by using an epoxy resin, preferably an aliphatic epoxy resin, and adding an ultraviolet absorber and an ultraviolet remover thereto. Alternatively, an acrylic resin and / or a polyurethane acrylate resin can be used. The weight ratio of mat to resin is the same percentage as the reinforcement used to strengthen the backside of the slab.

According to a practical test using the method of the present invention,
The bending resistance of a slab with a thickness of 10 to 12 mm is 120 to 180 with respect to its front, ie appearance side.
From a value of kg / cm ² (depending on the stone material of which the slab is made) to 400 to a value of 800 kg / cm ² .

After the resin curing step, the outer surface of the obtained slab is subjected to polishing and / or overcoating, and the matte on the other rear surface and the reinforcing layer made of transparent resin are not flattened and / or polished. By this industrial work,
The external surface becomes transparent.

According to a variant, which is also particularly useful when it is desired to increase the resistance of the slab's appearance to cracking and abrasion, the resin is additionally provided with suitable anti-cracking agents and / or glass or The fine quartz powder is filled in an amount that does not impair the transparency of the resin.

The main advantage of the method according to the invention is that in the case of marble or other limestone slabs, the reinforcing layer obtained by the method according to the invention also shows that when such a material is used as a facing material. One of the problems is that it exhibits protective hardening against yellowing and / or discoloration.

Furthermore, marble and limestone are vulnerable to the action of acids and, likewise, the action of so-called acid rain,
The present invention can also substantially solve these special problems and drawbacks.

Similarly, for example, in the case of a porous stone material such as precipitated limestone, the outer surface reinforcement layer, or the layer formed on the front surface of the slab, significantly reduces the amount of water absorbed in the openings in the front surface of the stone material. So improve the slab's resistance to destruction or damage due to changes in hot and cold seasons.

The attached drawings show a schematic view of a slab reinforced on both sides.

In the drawings, and particularly in FIG. 1, reference numeral 10 indicates a stone slab having a thickness of 10 mm or less (this thickness is not a limiting constitution of the present invention) and having a front surface, that is, an outer surface 12 and a back surface 14. The back surface 14 is reinforced by a mat 16 of glass threads 18 and an epoxy resin layer 20 using the method which constitutes the means of the invention described above.

As described above, in the case where the back surface 14 is more firmly and sufficiently strengthened, the back surface 14 is provided with a linear member, for example, a groove or a cavity for containing a glass fiber strand, and is filled with an epoxy resin.

The front surface 12 is provided with a reinforcing layer,
The reinforcing layer comprises a large number of untwisted glass yarns 22, preferably in the form of mats 24, in the surface area of the slab, from about 100 to 800, preferably about 5 per square meter.
An amount equivalent to 00 grams is included.

In FIG. 2, a schematic structure of a part of the mat 24 is exaggeratedly shown. The mat 24 is composed of a transparent glass yarn which is arranged thinner than the glass yarn of the mat for reinforcing the back surface.

Reference numeral 26 indicates a protective reinforced resin layer,
The protective reinforcing layer 26 needs to be transparent and hardenable, and also resistant to the action of external air sources (in particular, the yellowing action often caused by ultraviolet rays on plastic materials).

Epoxy resins, preferably aliphatic epoxy resins, with the addition of UV absorbers and / or so-called UV filters have been found to be particularly useful. Alternatively, an acrylic resin (including both the acrylic resin itself and the methacrylic resin) and a copolymer of the acrylic resin and the methacrylic resin with another monomer, for example, a urethane monomer also satisfy the above-mentioned requirements. After the mat and resin have been applied, the resin is cured and then the finishing operation described above is performed.

As described above, when it is desired to strengthen the surface 12 so as to provide resistance to cracking and abrasion, the resin 26
It is possible by filling silica powder or quartz powder in an amount that does not impair the complete transparency of the reinforcing layer. On resin,
In addition to them, or in addition, a known crack preventing agent may be added.

Further, according to the strengthening method of the present invention,
Similarly, the slab's cosmetic resistance to the action of aggressive chemicals such as acids can be improved.

Although the present invention has been described above with reference to the preferred embodiments, equivalent modifications and changes with respect to objects and configurations are within the scope of the present invention.
It is possible. For example, the back surface of the slab, that is, the non-appearance surface, may be reinforced in a method different from the above method,
Glass material and / or fireproof and / or sound absorbing properties
Or it may be compounded with other materials, such as a composite slab of stone.

[0032]

As described above, according to the present invention,
It is possible to provide a stone slab that is thin and reinforced on both sides so as to have increased resistance to both positive and negative bending, and whose aesthetic properties of the stone have not been changed for a long time.

[Brief description of drawings]

FIG. 1 is a schematic side sectional configuration diagram showing an example of a reinforced stone slab according to the present invention.

FIG. 2 is a schematic plan view showing a part of the mat of the reinforced stone slab according to the present invention.

[Explanation of symbols]

 10 Stone Slab 12 Front Surface (Exterior Surface) 14 Back Surface (Non-External Surface) 16 Glass Yarn Mat 18 Glass Yarn 20 Epoxy Resin Layer 22 Glass Yarn 24 Glass Yarn Mat 26 Protective Reinforcement Resin Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location E04D 3/02 (71) Applicant 597013238 Via Papa Giovanni X XIII, 2 36061 Bassano del Grappa (Vicenza) Italy

Claims (18)

[Claims] 1. A reinforcing material layer formed by embedding non-twisted glass yarns in a transparent curable resin resistant to external air factors on the front surface, ie, the external surface of a stone slab whose rear surface, that is, the non-external surface is reinforced. A method for manufacturing a strengthened stone slab characterized by forming 2. A method according to claim 1, characterized in that the backside of the slab is strengthened by the method forming the subject of European patent application No. 95201590.7. 3. The method of claim 1, wherein the resin is resistant to chemicals. 4. The method of claim 1, wherein the untwisted glass yarn is matte. 5. The method of claim 4 wherein the matte content is about 100 to 800 grams per square meter of slab surface. 6. The method of claim 5, wherein the matte content is about 500 grams per square meter of slab surface. 7. The method of claim 1, wherein the resin is selected from epoxy, acrylic and methacrylic resins, copolymers of these with other monomers having the above properties. 8. The method of claim 7, wherein the resin is an aliphatic epoxy resin. 9. The method according to claim 1, wherein an anti-cracking agent and an anti-wear agent are added to the resin layer. 10. The method according to claim 1, wherein the resin layer is filled with a powder material capable of improving resistance to abrasion or cracking of the finished surface of the slab. 11. The method according to claim 10, wherein the powder material is selected from fine powders of quartz and silica stone. 12. A reinforced stone slab characterized in that a reinforced layer composed of untwisted glass yarn and a transparent curable resin resistant to external air factors is formed on the outer surface thereof. 13. The reinforced stone slab of claim 12 wherein the resin is resistant to chemicals. 14. Reinforced stone according to claim 12, characterized in that the stone is selected from marble, precipitated limestone, granite, porphyry and similar substances, and the untwisted glass threads are matte. Slab. 15. The reinforced stone slab according to claim 12, wherein the resin is selected from an epoxy resin, an acrylic resin and a methacrylic resin, and a copolymer of these with a monomer having the characteristics. 16. The reinforced stone slab according to claim 15, wherein the resin is an aliphatic epoxy resin. 17. The reinforced stone slab according to claim 12, wherein the back surface, that is, the non-appearance surface is reinforced. 18. Reinforced stone slab according to claim 17, characterized in that said back or non-appearance surface is reinforced by the method described in European patent application No. 95201590.7.