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Title:
IMPROVEMENTS TO A BOARD
Document Type and Number:
WIPO Patent Application WO/2018/154287
Kind Code:
A1
Abstract:
A board comprises a rigid plastics foam core, and one or more plastics layers at least partially covering said rigid plastics foam core; said at least one plastics layer incorporating microspheres for reflecting light..

Inventors:
THOMPSON, Steven John (Unit A Castle Court,Bodmin Road, Coventry West Midlands CV2 5DB, CV2 5DB, GB)
Application Number:
GB2018/050439
Publication Date:
August 30, 2018
Filing Date:
February 20, 2018
Export Citation:
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Assignee:
THE MILLBOARD COMPANY LIMITED (Unit A, Castle CourtBodmin Road, Coventry West Midlands CV2 5DB, CV2 5DB, GB)
International Classes:
E04C2/20; E04B1/76; C09D5/33
Foreign References:
US20070289234A12007-12-20
US20120073225A12012-03-29
DE102011009994A12012-08-02
DE202014105390U12015-02-26
US20040068046A12004-04-08
US5534348A1996-07-09
Other References:
DATABASE WPI Week 201555, Derwent World Patents Index; AN 2015-45638C, XP002781156
DATABASE WPI Week 201571, Derwent World Patents Index; AN 2015-62385M, XP002781157
Attorney, Agent or Firm:
IP21 LIMITED (Lakeside 300, Old Chapel WayBroadland Business Park, Norwich Norfolk NR7 0WG, NR7 0WG, GB)
Download PDF:
Claims:
Claims

1. A board comprising a rigid plastics foam core, and one or more plastics layers at least partially covering said rigid plastics foam core; said at least one plastics layer incorporating microspheres for reflecting light, wherein said foam core is a foamed polyurethane and acts as a support beam whilst the or each layer is softer than said core.

2. A board according to claim 1, wherein said microspheres comprise glass. 3. A board according to either claim 1 or claim 2, wherein said microspheres have a mean diameter of 10 to 100 microns.

4. A board according to any of the preceding claims, wherein said at least one plastics layer comprises infrared reflective pigments.

5. A board according to any of the preceding claims, further comprising an outermost layer comprising plastics material and pigment without any microspheres.

6. A board according to any of the preceding claims, wherein said rigid plastics foam core and an adjacent plastics layer are melded together.

7. A board according to any of the preceding claims, wherein each adjacent layer is melded to an adjacent plastics layer. 8. A board according to any of the preceding claims, wherein said foam core incorporates fibres to provide structural reinforcement whilst said at least one layer comprises no fibres.

9. A board according to any of the preceding claims, wherein at least one layer comprises elastomeric polyurethane.

10. A board according to any of the preceding claims, wherein at least one layer incorporates coloured pigments.

1 1. A board according to any of the preceding claims, wherein at least one layer incorporates an additive with flame retardant properties.

12. A board according to any of the preceding claims, wherein at least one layer incorporates an additive with biocidal properties.

13. A board according to any of the preceding claims, wherein at least one layer is moulded to form a relief or pattern. 14. A board according to any of the preceding claims, wherein said foam core comprises by weight of about 30 to about 45% of polyol.

15. A board according to any of the preceding claims, wherein said foam core comprises by weight of about 20 to about 35% of isocyanate.

16. A board according to any of the preceding claims, wherein said foam core comprises by weight of about 50 to about 70% of filler.

17. A board according to any of the preceding claims, wherein said foam core comprises by weight of about 4 to about 10% of fibres.

18. A board according to claim 5, wherein said outermost layer comprises by weight of about 60 to about 80% of polyol. 19. A board according to claim 5, wherein said outermost layer comprises by weight of about 8 to about 15% of isocyanate.

20. A board according to claim 5, wherein said outermost layer comprises by weight of about 5 to about 20% of pigments.

21. A board according to claim 5, wherein said outermost layer comprises by weight of about 25 to about 50% of solvents.

Description:
Improvements to a Board

Field of the Invention

The invention relates to boards. In particular, the invention relates to boards formed primarily from polymeric material.

Background to the Invention

Wood has been used as a building material for thousands of years, both for its ease of use and its structural attributes. However, in recent years, the limitations of wood - such as its cost, weight, need for treatment and its susceptibility to infestation and decay - have resulted in a shift towards using alternative plastics materials. The applicant's own prior patent application published as EP1951971 has comprehensively addressed these issues and constitutes the closest prior art.

The invention provides a number of improvements to this art.

CN104652693A and CN204590404 are acknowledged but don't address the same issues as those tackled by the invention since they are rigid throughout their layers.

CN104652693A discloses a board with a bright film layer and a brilliant layer coated over a reflective layer, on top of a strong outer layer made of thick board, a transition layer and a support layer. The outer bright film layer is a fluorocarbon coating and forms a translucent top coating. Being based on fluorocarbons, the top coating has high rigidity, being harder than the support layer. Furthermore, the strong outer layer is also harder than the support layer. CN204590 O4 discloses a heat envelope structure, with an insulation layer made of polystyrene foam board, a reinforcement layer, and a layer with glass microbeads.

This document does not disclose or suggest the layer being made of plastics, nor a foamed polyurethane. Furthermore, it also does not disclose each outer layer being softer than said the foam core, nor an outermost layer comprising plastics material and pigment without any microspheres. In contrast, the prior art requires an outermost layer which does include microbeads.

Summary of the Invention In a first broad independent aspect the invention provides a board comprising a rigid plastics foam core, and one or more plastics layers at least partially covering said rigid plastics foam core; said at least one plastics layer incorporating microspheres for reflecting light. This is particularly advantageous because the plastics foam core creates the structural support required whilst remaining lightweight. A foamed core also has decreased density which therefore requires less reactants to produce each board, and is therefore efficient to produce. In addition, the microspheres reflect light away from the board and reduce the amount of radiation that the board absorbs when left in direct sunlight. The temperature of a board left in sunlight is directly proportional to the amount of radiation that said board absorbs and therefore, the microspheres help to prevent the board from becoming hot when left in direct sunlight. Thus, ensuring the board is comfortable for the user to touch and optionally walk upon. Preferably, the microspheres comprise glass. This configuration is particularly advantageous due to its enhanced reflectivity when compared to plastics alternatives whilst lending itself to being efficiently melded into the plastics layer which acts as a support matrix for the glass microspheres. Preferably, at least one plastics layer comprises infrared reflective pigments. This is particularly advantageous because the infrared pigments reflect light in the infrared spectrum, helping to prevent the board from absorbing radiation which would heat the board up. Furthermore, the microspheres and the infrared pigments work in a synergistic fashion, reflecting more light in combination then the sum total of their parts in isolation.

Preferably, the board further comprises an outermost layer comprising plastics material and pigment without any microspheres. This is particularly advantageous because additives such as microspheres affect the consistency of a plastics layer and therefore dictate, to an extent, the physical properties of a plastics layer. By not including microspheres, the outermost plastics layer is able to create the soft touch feel to the user that is preferable.

Preferably, the rigid plastics foam core and an adjacent plastics layer are melded together. This is particularly advantageous because it enables the layers to be physically attached to one another without the use of additional adhesives. This also facilitates a thermal setting process suitable for securing one layer to another in a mould.

Preferably, each adjacent layer is melded to an adjacent plastics layer. This provides an advantageously secure and therefore long lasting bond between adjacent layers. Preferably, the foam core acts as a support beam whilst the or each layer is softer than said core. This is particularly advantageous because the rigid foam core provides the structural support and the outer layers, which are softer, provide comfort for the user, which in one embodiment may be suitable for walking upon. Preferably, the foam core incorporates fibres to provide structural reinforcement whilst said at least one layer comprises no fibres. This is particularly advantageous because the fibres increase the structural rigidity of the board and enables the board to provide the same structural support with a decreased density. It also allows the outer layers to encapsulate the layers with fibres which prevent them from being exposed.

Preferably, the foam core is a foamed polyurethane. In addition, the formation of the urethane linkage releases C02 which helps to foam the core decreasing the volume of external blowing agent required. Preferably, at least one layer comprises elastomeric polyurethane. This is particularly advantageous since it allows the microspheres to be secured to the elastomeric polyurethane whilst allowing it to retain sufficient elasticity to be soft to touch. Preferably, the at least one layer incorporates coloured pigments.

Preferably, wherein at least one layer incorporates an additive with flame retardant properties. This is particularly advantageous because it reduces the fire hazard posed by traditional wood planking or plastic boards.

Preferably, the at least one layer incorporates an additive with biocidal properties. This is particularly advantageous because it prevents the growth of moulds or fungus which in wet conditions can become slippery and potentially dangerous for any user walking across the boards.

Preferably, the at least one layer is moulded to form a relief or pattern. This creates a natural feel to the board whilst achieving advantageous multidirectional reflectivity since the microspheres may be provided on all aspects of the formed relief. Optionally, the foam core comprises by weight of about 30 to about 45% of polyol.

Optionally, the foam core comprises by weight of about 20 to about 35% of isocyanate.

Optionally, the foam core comprises by weight of about 50 to about 70% of filler.

Optionally, the foam core comprises by weight of about 4 to about 10% of fibres. The fibres are optionally a form of filler.

Optionally, the outermost layer comprises by weight of about 60 to about 80% of polyol.

Optionally, the outermost layer comprises by weight of about 8 to about 15% of isocyanate. Optionally, the outermost layer comprises by weight of about 5 to about 20% of pigments.

Optionally, the outermost layer comprises by weight of about 25 to about 50% of solvents.

Brief Description of the Figures

Figure 1 shows a board in cross sectional side view.

Detailed Description of the Figures

According to the present embodiment, the board comprises a rigid foamed plastics core with at a least one softer plastics coating on at least the upper surface of the foamed plastics core.

In a preferred embodiment, the board comprises a rigid foamed polyurethane core with a first elastomeric polyurethane coating on at least the upper surface of the core and a second elastomeric polyurethane paint on at least the upper surface of the elastomeric coating.

The polyurethane core provides the structural rigidity to support the weight of the board, and in a preferred embodiment, support the weight of one or more humans walking on the board.

In one embodiment, the covering layers may be elastomeric layers. These may include the elastomeric polyurethane coating and the elastomeric polyurethane paint. These are softer than the core and therefore provide a cushioning effect for the user standing on the boards. In an alternative embodiment, the covering layers may be rigid polymeric layers.

In the elastomeric embodiment, the elastomeric coating or coatings include infrared pigments and glass microspheres which may be embedded therein. These features work in a synergistic way to reflect light and inhibit the absorption of light into the board. As a result, the boards can be placed in direct sunlight without becoming unpleasantly hot, making them ideal for outdoor decking or the like. This also allows the boards to have longer life cycles as they will be less prone to the effects of changes in temperature.

Polyurethane is a polymer composed of organic units joined by carbamate (urethane) links.

Polyurethane foams and polyurethane elastomers are formed by reacting a polyol with an isocyanate, typically in the presence of a catalyst and other additives. The urethane linkage is produced by reacting an isocyanate group with a hydroxyl group on the polyol. Preferably, the isocyanate comprises at least two isocyanate functional groups per molecule and the polyol comprises at least two hydroxyl groups per molecule. There are a wide variety of polyol and isocyanate compounds which can be used in the production of polyurethane. By altering the monomeric building blocks, the relative quantities of each, the reaction conditions and the type and quantity of additives included, it is possible to produce a polyurethane product with vastly different mechanical and physical properties. It should be understood that all values of reaction compounds and conditions within this specification and claim set, are estimations prefixed by the term 'about', and therefore unless otherwise stated should be assumed to be approximations. Furthermore, the relative abundance of each component part is alterable to create the physical properties required for a given purpose and therefore the current invention should not be considered limited by the ranges provided. In further embodiments, the ranges specified may be exact limits should these need to be expressed without the use of the term "about".

The term 'melded' in the context of the current invention refers to the physical attachment of distinct compounds during a thermosetting moulding process, without the use of adhesives.

To provide clarity, the components of the system which are common to different figures have retained identical numerical references throughout all figure descriptions.

Figure 1 shows a first embodiment of a board 10 in cross sectional side view. The structural support of the board 10 is provided by the rigid plastics foam core 12. In a preferred embodiment, the foam core 12 is a rigid foamed polyurethane. In a further preferred embodiment, the foam core comprises by weight; from about 30% to about 45% of polyol, from about 20% to about 35% of isocyanate, from about 50% to about 70% of filler, from about 0.1 % to about 2% of blowing agent. The filler may be a fibre which itself constitutes from about 4% to about 10% of the weight of the foam core. Fillers may be selected from the following or a combination of the following: calcium, barium, carbonates, sulphates, glass fibre, aluminium trihydrate, phosphonate salts, boron salts.

In a preferred embodiment, the polyol may be a poly ether polyol.

In a preferred embodiment, the isocyanate is an aromatic isocyanate.

In a preferred embodiment, the fibre is a glass fibre. In a further preferred embodiment, the glass fibre is an E or S type glass fibre.

In the embodiment of Figure 1, a plastics layer 14 is melded to the foam core 12 at the boundary 13. Preferably, the plastics layer 14 has the physical properties of being softer than the foam core 12 and can provide a cushioning effect on any force that comes into contact with the plastics layer 14. In a preferred embodiment, the plastics layer 14 is an elastomeric plastic. In a further preferred embodiment, the plastics layer 14 is an elastomeric polyurethane.

The plastics layer 14, is preferably 1 mm to 3mm thick and has additives to improve its physical properties. These additives are added to the liquid plastics and mixed to form a homogenous blend which is then thermoset. Microspheres may be added in one embodiment as the sole additive or in other embodiments as part of several other additives which together have a synergistic effect on certain properties of the board. Preferably, the microspheres range from 100 nanometres to 5 millimetres in diameter. Further preferably, the microspheres range from 250μιη to 3mm. In a preferred embodiment, the microspheres range from 10 to 100 microns. Preferably, the

microspheres range from 30 to 60 microns. Preferably, the microspheres have a mean diameter of about 55 microns. Preferably, the glass microspheres are located in the first 1 to 3 mm from the exposed surface of the board and constitute in volume between 5% and 25% of the layer's volume. In a preferred embodiment, the microspheres are glass microspheres. Preferably, the glass microspheres are virgin raw material, however, alternatively they could be from recycled sources. Alternatively, the microspheres could be transparent thermoplastic or any other suitable material. In an embodiment, the microspheres are hollow, further reducing the weight of the board 10.

In a preferred embodiment, the microspheres comprise sodium borosilicate and synthetic silica. Preferably, the microspheres comprise amorphous sodium borosilicate and synthetic amorphous silica. The effective density of the microspheres is preferably less than 0.3, preferably less than 0.25, preferably less than 0.2, and preferably higher than 0.1.

In a preferred embodiment, the effective density is 0.19. Preferably, the effective density is 0.19 +/- 0.03. In a preferred embodiment, the microspheres have a thermal conductivity of less than 0.07 and higher than 0.05 (w/m.K) at 21 degrees Celsius. Preferably, the microspheres have a thermal conductivity of about 0.06. Preferably, the microspheres have a thermal conductivity of 0.056. Preferably, the microspheres have a heat capacity of 1 KJ.Kg degrees Celsius. Preferably, the microspheres have a mean particle size of about 55 microns. Preferably, the microspheres have a mean particle size of between 10 microns and 100 microns. Preferably, the microspheres have a mean particle size of between 50 and 60 microns.

In the current embodiment, the reflective properties of the microspheres help reflect light radiation away from the board 10. In a preferred embodiment, the microspheres have a reflective index of between 1.523 and 1.925. In a further preferred embodiment, the microspheres have a reflective index of 1.55. Light energy absorbed by the board 10 will be converted into heat energy to cause the board 10 to become hot. By reflecting light away from the board 10, the microspheres help to prevent the board from overheating, and to remain cool to the touch. Furthermore, direct light can lead to oxidation reactions occurring within the board 10 which can lead to degradation. Therefore, by reflecting the light, the microspheres help to maintain the quality of the board and prevent degradation.

In addition to the microspheres, the plastics layer 14 includes infrared pigments, which reflect infrared (IR) light. As is the case with the microspheres, by reflecting light from the board 10, the IR pigments help to prevent the board 10 from heating up when left in direct sunlight. Furthermore, the combination of the microspheres and the IR pigments has a synergistic effect on the amount of light energy reflected by the boards 10, reflecting more light energy in combination then the combined total each additive would reflect in isolation.

In a preferred embodiment, the pigments are solar reflective pigments. In a further embodiment, the pigments are non-volatile at 68 to 72%. In a preferred embodiment, the elastomeric polyurethane layer 14 would include one or more additives with flame retardant properties. These compounds could include but are not limited to: ammonium phosphate, molybdenum trioxide, pentabromodiphenyloxide, tricresyl phosphate, 2,3-dibromopropanol or tri(2-chloroethyl) phosphate. Such

compounds reduce the potential of a fire risk. In a preferred embodiment, the elastomeric polyurethane layer 14 is a thermoplastic polyurethane material which is cross linked with MDI (Methylene diphenyl diisocyanate) type isocyanates and/or aliphatic type isocyanates. In a preferred embodiment, the polyurethane layer comprises a polyester and polyether polyols. In a preferred embodiment, the layer further comprises one or more flame retardants, one or more varieties of infrared and solar reflective pigments. In a preferred embodiment, the layer comprises one or more of the following: biocides, one or more additional fillers, surfactants and one or more catalysts. In a further subsidiary aspect, the elastomer comprises one or more of the following: processing aids, wetting agents, rheology modifiers and surfactants. In further embodiments, one or each of the layers comprise a flame retardant package utilising phosphorous and nitrogen compositions. In a preferred embodiment, calcium- based fillers and/or modified aluminium tri hydroxide is envisaged.

Preferably, the or each layer incorporates powder grade biocides in conjunction with the above.

In a preferred embodiment, the elastomeric polyurethane layer 14 would include one or more additives with biocidal properties, including antimicrobial and antifungal properties. This would protect the boards from microbial degradation and coverage with moulds and fungi. Moulds and fungi are common growths on traditional wooden or stone slates when left in the elements such as around a pool or patio area. One by product of such growths is that the boards or slabs become particularly slippery and dangerous to walk across, requiring regular cleaning or maintenance to prevent build up. The inclusion of one or more additives with biocidal properties within the elastomeric polyurethane layer 14 prevents the dangerous build-up of slimes and moulds that would otherwise be time consuming to remove.

In a preferred embodiment, the elastomeric polyurethane layer 14 comprises by weight; from about 50% to about 60% of polyol, from about 4% to about 6% of isocyanate, from about 0.8% to about 1.2% of biocide, from about 30% to about 45% of flame retardant, from about 0.4% to about 2% of pigments.

In a preferred embodiment, the outer surface 15 of the elastomeric polyurethane layer 14 would be ridged and troughed so as to produce a pattern or relief, as seen in figure 1. In a further preferred embodiment, the relief on the surface 15 of the elastomeric polyurethane layer 14 would mimic wood grain, and provide a realistic wood look and feel.

In the embodiment of Figure 1, a plastics paint 16 is melded to the plastics layer 14 at the surface 15. In a preferred embodiment the combination of the layer 16 and layer 14 is of 1 millimetre to 4 millimetres. In a preferred embodiment, the plastics paint 16 is an elastomeric polyurethane paint. In a preferred embodiment, the elastomeric polyurethane paint has a composition by weight; from about 60% to about 80% of polyol, from about 5% to about 20% of pigments, from about 25% to about 50% of solvents.

In a preferred embodiment, the plastics paint 16 contains pigments required to create an authentic look of wood planks. In an embodiment, a UV screener such as

hydroxybenzotriazole is incorporated into the plastics paint 16 to help prevent oxidation reactions within the plastics paint 16 and the plastics layer 15, which would lead to degradation.