COMPOSITION FOR SYNTHETIC STONE AND SYNTHETIC STONE MANUFACTURED THEREOF

Abstract

A composition for a synthetic stone is disclosed, the composition is based on a component A that includes an acrylic resin and a component B including a filler.

Claims

1. Composition for a synthetic stone comprising a component A: 3 to 25 weight-% acrylic resin based on the total weight of the composition, the acrylic resin comprising: i) methyl methacrylate monomer residues in the range of 2 to 28 weight-% based on the total weight of component A, wherein the methacrylate monomer residues have a molecular weight of greater than 10,000 Da; ii) at least one linear or branched mono(alk)acrylate monomer in the range of 60 to 97 weight-% based on the total weight of component A, wherein any mono(alk)acrylate with a boiling point of less than 105° C. is no more than 12 weight-% based on the total weight of the mono(alk)acrylate; iii) a crosslinking agent in the range of 1 to 10 weight-% based on the total weight of component A; and a component B: filler in the range of 75 to 97 weight-% based on the total weight of the composition.

2. Composition according to claim 1, wherein component A further comprises iv) methyl methacrylate monomer in the range of 1 to 12 weight-%.

3. Composition according to claim 1, wherein the component A further comprises other acrylate or vinyl comonomer residues in the range of up to 10 weight-%.

4. Composition according to claim 1, wherein the composition further comprises a component C in the form of a coupling agent.

5. Composition according to claim 1, wherein the component A, the acrylic resin as defined in claim 1 has glass transition temperature Tg of at least 40° C.

6. A kit of parts for forming synthetic stone, the kit of parts comprising: a component A part: 3 to 25 weight-% acrylic resin based on the total weight of the composition, the acrylic resin comprising: i) methyl methacrylate monomer residues in the range of 2 to 28 weight-% based on the total weight of component A, wherein the methacrylate monomer residues have a molecular weight of greater than 10,000 Da; ii) at least one linear or branched mono(alk)acrylate monomer in the range of 60 to 97 weight-% based on the total weight of component A, wherein any mono(alk)acrylate with a boiling point of less than 105° C. is no more than 12 weight-% based on the total weight of the mono(alk)acrylate; iii) a crosslinking agent in the range of 1 to 10 weight-% based on the total weight of component A; and a component B part: filler in the range of 75 to 97 weight-% based on the total weight of the composition.

7. Composition according to claim 1, further comprising a component D: an initiator system.

8. A method of manufacturing synthetic stone from the composition of claim 1, the method comprising the following steps: a) mixing the acrylic resin and the filler; b) adding the mixture to a mold and substantially de-aerating the mixture; and c) curing the mixture by heating.

9. Method according to claim 8, wherein a cured mixture from the curing step is in a further step d) polished.

10. Synthetic stone manufactured by the method according to claim 8.

11. A kit of parts according to claim 6, further comprising a component D: an initiator system.

12. The method according to claim 8, wherein the mixing step further comprises mixing a coupling agent with the acrylic resin and the filler.

13. The method according to claim 8, wherein the mixing step further comprises mixing an initiator system with the acrylic resin and the filler.

14. The method according to claim 8, wherein the mixing step is carried out until a uniform mixture is obtained.

15. The method according to claim 8, wherein the step of adding the mixture to the mold and substantially de-aerating the mixture is conducted with application of vacuum, compaction and/or vibration.

16. The method according to claim 8, wherein the curing step is conducted by heating to a temperature of between 75° C. and 130° C.

17. The method according to claim 8, wherein the curing step is conducted by heating to a temperature of between 85° C. and 125° C.

Description

DETAILED DESCRIPTION

Example 1

[0058] 10% methyl methacrylate, 51.9% iso-butyl methacrylate, 1% 1,4-butanediol dimethacrylate, 13% hydroxyethyl methacrylate, 24% poly(methyl methacrylate) (Diakon LG156) (all w/w %) and 0.14% of a combination of stabilisers were stirred at 50° C. for 2 hours to form a uniform mixture. The stabiliser combination comprises 0.09% 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04% bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.01% 2,6-di-tert-butyl-4-methylphenol (all w/w %). Further, 1 wt-% 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt-% azo-di-isobutyronitrile were added to the cooled resin to activate the same.

[0059] A quartz mix was then prepared using 10.8 w/w % activated resin together with 1.1 w/w % colouring pigment (Chemours Ti-Pure R960), 30.5 w/w % milled silica (particle diameter<45 micron), and 57.6 w/w % crystalline quartz (particle diameter between 0.3-0.8 mm)

[0060] The activated resin and the quartz mix were mixed to form a wet sand and then subjected to vibrations of 3500 rpm for 90 seconds under a vacuum of 12 mbar. The composition was cured at 115° C. for 30 minutes. Subsequently, the slab was cut and polished to produce a tile which was then subjected to mechanical testing. The resulting flexural strength was measured as 65.5±1.8 MPa. The flexural strength measurement was performed in accordance with EN ISO 14617-2.

Example 2

[0061] 63.5% n-butyl methacrylate, 1.8% ethylene glycol dimethacrylate, 13.6% hydroxyethyl methacrylate, 21% poly(methyl methacrylate) (Diakon LG156) (all w/w %) and 0.14% of a combination of stabilisers were stirred at 50° C. for 2 hours to form a uniform mixture. The stabiliser combination comprises 0.08% 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04% bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.01% 2,6-di-tert-butyl-4-methylphenol (all w/w %). Then, 1 wt-% 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt-% azo-di-isobutyronitrile were added to the cooled resin to activate the same.

[0062] A quartz mix was then prepared using 10.8 w/w % activated resin together with 1.1 w/w % colouring pigment (Chemours Ti-Pure R960), 30.5 w/w % milled silica (particle diameter<45 micron), and 57.6 w/w % crystalline quartz (particle diameter between 0.3-0.8 mm)

[0063] The activated resin and the quartz mix were mixed to form a wet sand and then subjected to vibrations of 3500 rpm for 90 seconds under a vacuum of 12 mbar. The composition was cured at 115° C. for 30 minutes. Subsequently, the slab was cut and polished to produce a tile which was then subjected to mechanical testing. The resulting flexural strength was measured as 54.4±1.3 MPa. The flexural strength measurement was performed in accordance with EN ISO 14617-2.

Example 3

[0064] 10% methyl methacrylate, 51.9% n-butyl methacrylate, 1% 1,4-butanediol dimethacrylate, 13% hydroxyethyl methacrylate, 24% poly(methyl methacrylate) (Diakon LG156) (all w/w %) and 0.14% of a combination of stabilisers were stirred at 50° C. for 2 hours to form a uniform mixture. The stabiliser combination comprises 0.09% 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04% bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, and 0.01% 2,6-di-tert-butyl-4-methylphenol (all w/w %). Further, 1 wt-% 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt-% azo-di-isobutyronitrile were added to the cooled resin to activate the resin.

[0065] A quartz mix was then prepared using 10.8 w/w % activated resin together with 1.1 w/w % colouring pigment (Chemours Ti-Pure R960), 30.5 w/w % milled silica (particle diameter<45 micron), and 57.6 w/w % crystalline quartz (particle diameter between 0.3-0.8 mm)

[0066] The activated resin and the quartz mix were mixed to form a wet sand and then subjected to vibrations of 3500 rpm for 90 seconds under a vacuum of 12 mbar. The composition was cured at 115° C. for 30 minutes. Then, the slab was cut and polished to produce a tile which was then subjected to mechanical testing. The resulting flexural strength was measured as 61.2±1.4 MPa. The flexural strength measurement was performed in accordance with EN ISO 14617-2.

Example 4

[0067] 12% methyl methacrylate, 80.86% hydroxyethyl methacrylate, 2% 1,4-butanediol dimethacrylate, 5% poly(methyl methacrylate) (Diakon LG156) (all w/w %) and 0.14% of a combination of stabilisers were stirred at 500° C. for 2 hours to form a uniform mixture. The combination of stabilisers comprises 0.09 w/w % 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04 w/w % Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.01 w/w % 2,6-di-tert-butyl-4-methylphenol. To the cooled resin was added 1 wt % 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt % azo-di-isobutyronitrile to activate the resin.

[0068] A quartz mix was then prepared using 10.5 w/w % activated resin together with 1.1 w/w % inorganic colouring pigment (Chemours Ti-Pure R960), 30.6 w/w % milled silica (particle diameter<45 micron) and 57.8 w/w % crystalline quartz (particle diameter between 0.3-0.8 mm).

[0069] The composition was mixed to form a wet sand then subjected to vibrations of 3500 rpm for 60 seconds under a vacuum of 12 mbar. The composition was cured at 115° C. for 45 minutes. The slab was subsequently cut and polished to produce a tile which was then subjected to mechanical testing. The resulting flexural strength was measured as 59.5±2.2 MPa. The testing of the flexural strength was performed in accordance with EN ISO 14617-2

Example 5

[0070] 12% methyl methacrylate, 80.86% ethyl methacrylate, 2% 1,4-butanediol dimethacrylate, 5% poly(methyl methacrylate) (Diakon LG156) (all w/w %) and 0.14% of a combination of stabilisers (0.09 w/w % 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04 w/w % Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.01 w/w % 2,6-di-tert-butyl-4-methylphenol) were stirred at 500° C. for 2 hours to form a uniform mixture. To the cooled resin was added 1 wt % 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt % azo-di-isobutyronitrile to activate the resin.

[0071] A quartz mix was then prepared using 10.5 w/w % activated resin together with 1.1 w/w % inorganic colouring pigment (Chemours Ti-Pure R960), 30.6 w/w % milled silica (particle diameter<45 micron) and 57.8 w/w % crystalline quartz (particle diameter between 0.3-0.8 mm).

[0072] The composition was mixed to form a wet sand then subjected to vibrations of 3500 rpm for 30 seconds under a vacuum of 12 mbar. It was cured at 115° C. for 45 minutes. Again, the slab was cut and polished to produce a tile which was subjected to mechanical testing. The resulting flexural strength was measured as 59.6±1.2 MPa. Flexural strength measurements were completed in accordance with EN ISO 14617-2.

Comparative Example 1

[0073] 44.2% methyl methacrylate, 5.4% iso-butyl methacrylate, 8.8% n-butyl methacrylate, 0.6% ethylene glycol dimethacrylate, 38% poly(methyl methacrylate) (Elvacite 4071) (all w/w %) and 0.14% of a combination of stabilisers were stirred at 50° C. for 2 hours to form a uniform mixture. The combination of stabilisers comprises 0.09% 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04% bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.01% 2,6-di-tert-butyl-4-methylphenol) (all w/w %).

[0074] A quartz mix was then prepared following the procedure outlined in Example 1. The resulting flexural strength was measured as 57.0±1.3 MPa. Flexural strength measurements were completed in accordance with EN ISO 14617-2.

Comparative Example 2

[0075] 52.8% i-butyl methacrylate, 7.1% 1,4-butanediol dimethacrylate, 7.5% hydroxyethyl methacrylate, 31.5% poly(methyl methacrylate) (Elvacite 4071) (all w/w %) and 0.14% of a combination of stabilisers (0.09 w/w % 2-(2H-benzotriazol-2-yl)-p-cresol, 0.04 w/w % Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 0.1 w/w % 2,6-di-tert-butyl-4-methylphenol) and 1.0 w/w % glycerol triacetate were stirred at 50° C. for 2 hours to form a uniform mixture. To the cooled resin was added 1 wt % 3-methacryloxy-n-propyltrimethoxysilane and 0.15 wt % azo-di-isobutyronitrile to activate the resin.

[0076] An agglomerated slab was made according the same procedure as described in example 1. The resulting slab had a flexural strength of 45.5±1.0 MPa. Flexural strength measurement was tested in accordance with EN ISO 14617-2.

Experimental Results

[0077] The slab of example 3 was compared with an agglomerated slab made using the method of example 1 and the resin composition described in comparative example 2. The slabs of example 3 and comparative example 2 were cut into tiles consisting of a cross-section of 25 mm×13 mm (±1%). The tiles were then heated to different temperatures and their displacement distances before breakage was compared with a three-point bending test using a gap of 100 mm. The results are shown in table 1 below:

TABLE-US-00001 TABLE 1 Temperature 20° C. 65° C. 100° C. Example 3 0.5 mm 5.3 mm 12.0 mm Comparative 0.3 mm 0.6 mm  0.8 mm Example 2

[0078] Despite there being the expected higher internal stresses caused by relatively greater polymerisation shrinkage the displacement distance measured is more for Example 3 in relation to Comparative Example 2. This is of particular utility for heat shaping slabs produced using Example 3 at relatively cool temperatures. For example, the displacement distance of Example 3 is 15 times more at 100° C. than for Comparative Example 2. Even at 65° C. the displacement distance of Example 3 is over 6 times more than that for Comparative Example 4 at 100° C. This allows for higher bending of slabs at comparative temperatures and even at lower temperatures such as 65° C. where handling is safer, less energy demanding and allows for a greater production throughput.

[0079] To simulate and compare VOC (volatile organic compounds) emissions a resin and a quartz mix as described in examples 1 and 2 was mixed and left for 1 hour and the weight loss monitored. As a control a standard unsaturated polyester resin (Synthopan 140-40) was used. For the resin control the formulation of comparative example 1 was used and compared with example 1 and 2. The results are shown in table 2 below:

TABLE-US-00002 TABLE 2 Sample Total weight loss (w/w %) Polyester Control 0.18% Comparative Example 1 0.55% Comparative Example 2 0.04% Example 1 0.23% Example 2 0.15%