WO1996014999A2

WO1996014999A2 - Method of applying a patterned coating

Info

Publication number: WO1996014999A2
Application number: PCT/GB1995/002695
Authority: WO
Inventors: Terry Alan Langrish; Lee Stuart Speake
Original assignee: RODEX 5 SYSTEMS Ltd
Current assignee: RODEX 5 SYSTEMS Ltd
Priority date: 1994-11-16
Filing date: 1995-11-16
Publication date: 1996-05-23
Anticipated expiration: 1997-05-16
Also published as: GB9423126D0; AU3875795A; WO1996014999A3

Abstract

A method of laying a coating on a sub base comprising the steps of: (i) applying a mixture of epoxy resin, hardener and particulate material to the rigid sub base; (ii) imprinting a pattern on the mixture by pressing a textured sheet into the mixture. A composition obtained by mixing: a) composition obtained by mixing: (i) glycidyl ether C-13 and C-15 and (ii) 4,41-isopropylinediphenol-epichlorohydrin and bisphenol F-epichlorohydrin copolymer; b) a curing agent and c) particulate matter.

Description

METHOD OF APPLYING A PATTERNED COATING

This invention relates to composite materials for example for use in building. The invention further relates to methods of laying composite material.

Attempts hitherto make a composite material comprising epoxy resin and inorganic particulate material for use in building have generally resulted in a product having a bloom which makes it unsatisfactory.

According to any aspect of the invention there is provided a method of laying a coating on a sub base comprising the steps of: i applying a mixture of epoxy resin, hardener and particulate material to the rigid sub base, ii) imprinting a pattern on the mixture by pressing a textured sheet into the mixture.

Embodiments of the invention will be described by way of non limiting example.

Preferably the invention is applied to a concrete sub base but other rigid solid and clean sub bases may be used.

Where applied to new concrete it is desirable to allow the concrete to age for at least 28 days. Where efflorescence is present longer ageing is desirable to prevent significant reduction in bond strength. Some concrete is treated with wax based curing compounds. These should be removed for example by sand blasting or steam cleaning with strongly alkaline cleaners. If the new concrete has been exposed to contamination other than by foot traffic, cleaning to remove grease oil or paint is recommended. It is particularly preferred that power washing followed by a clean water rinse be adopted.

Old concrete may be a suitable base. Any grease, oil, paint or stain should be removed with a cleaning agent preferably by power washing. It is important that an alkaline film is not left on the surface It may be necessary or desirable to rinse thoroughly with clean water after cleaning Another preferred preparation especially for heavily contaminated concrete is hot compressed air burning of the sub base especially if the tack primer coat to be described hereinafter is applied while the concrete is still warm Sand blasting and vacuum shot blasting each provide especially good preparation since they are dry processes which physically remove the surface of the concrete leaving a clean textured finish

Other materials may be suitable as sub-bases For example asphalt or tarmacadam can be power washed and then sealed for example with a water based sealer Preferably the sub-base is rendered non-porous but this may be difficult to achieve with a tarmacadam or asphalt sub-base -

The prepared sub-base is then coated with tack primer A preferred tack primer as RODEX 5 TACK PRIMER a twin pack product consisting of -resm and hardener components If necessary or desired the base resin pack and base hardener may be thinned with up to 5% of Xylene or Ethoxal The tack primer may be applied by sheepskin roller in relatively small areas of say 5m**- per time

The topcoat is then prepared For example 25kg of kiln dried silica sand is placed into a mixing container 1 3 litres of Bisphenol A diglycidyl ether, Bisphenol F diglycidyl ether resin are placed in a mixing bucket 0 78 kg of hardener comprising cycloaliphatic amine, pigment and diisooctylphthalate plasticiser is stirred into the resin composition The resin/hardener mixture is then stirred into the sand until homogeneous This quantity should be sufficient to coat about 2 5m-** of primed base

Small portions of topcoat are placed on the sub-base about 0 75 m apart The top coat is then spread out to a depth of about 5mm with a smooth, level finish. The top coat is allowed to cure for about 45 minutes at ambient temperature.

A release coat of microfine hydrophobic powered silica is then spread over the partially cured top coat. Alternatively or additionally a release sheet for example of polyethylene or silicone may be used. A flexible mat bearing the patter to be imprinted as projections on the bottom surface is placed on the release coat. The pattern may simulate stone blocks. The maximum depth of the projections should be slightly less than the thickness of the top coat. For example when the top coat is laid 5mm thick the projections should be no more than 4mm. The mat is pressed firmly into the resin for example by foot pressure. Further mats are placed into position in a similar manner. In corners and confined areas a small section of mat may be mounted on a handle and pressed into position. It is not essential for all the top coat to be printed with the same pattern. For example a central area may be imprinted with a riven stone fan pattern and the edges provided with a running bond border.

The mats are generally left in situ until the top coat is cured and then removed.

By using selected resins the tendency for the composite to show a white surface blush is markedly reduced. Thus a preferred resin component comprises a liquid epoxy resin containing glycidylether C-13 and C-15, a modified liquid of Bisphenol A/F Epichlorohydrin resin comprising

4,4'-Isopropylinediphenol-Epichlorohydrin 35-50%

Bisphenol F-Epichlorohydrin Copolymer 35-50%

A preferred hardener comprises a modified cycloaliphatic amine containing benzyl alcohol less than 45% which contains 4,4'-methylenebis(cyclohexanamine) polymer. Thus according to the invention there is also provided a composition obtained by mixing a) A liquid epoxy resin comprising i) glycidyl ether C- 13 and C- 15 and ii) 4,4'-Isopropylinediphenol-epichlorohydrin and Bisphenol F- epichlorohydrin copolymer, b) a curing agent comprising 4,4'-methyIenebis (cyclohexanamine)polymer and optionally benzylalcohol, and c) particulate matter

The relative amounts of resin and particulate material are not absolutely critical. If insufficient resin is present the mixture will not bind together Little extra benefit is gained by using excess resin and if too much is used the natural appearance of the particulate material may be impaired. Preferably the volume ratio of resin to particulate material is in the range of 1 :3 to 1 : 10 more preferably 1 :4 to 1:7.5.

The resin component can be varied: but preferably comprise a reaction product of poiyglycidyl ethers of bisphenol A and/or bisphenol F with elpichlorohydrin. The resin component need not be modified. It may, if desired, be dissolved in a solvent. Optionally the resin component can contain reactive and/or non-reactive diluents. Preferred epoxide equivalent weights for liquid resins are in the range 170 to 250 and for solids 450 to 600 or 2000 to 4000. Epoxide content (in molkg"*) for liquid resins is preferably in the range 3.5 to 6.0 and for solids 1.9 to 2.30.

Preferred hardeners include aliphatic polyamines, cycloaliphatic polyamines, polyaminoamines, polyamino imidazoles and modified aromatic polyamines. the hardeners can be used alone or in combination. Accelerating catalysts may be added.

The particulate material may comprise kiln dried silica sand, aggregate, stone or synthetic granules.

Upto about 35% by volume based on the curing agent and resin of the product of water can be added. Preferred amounts are 5 to 20%

In some embodiments of the invention the sub base comprises a sheet or board on which the composite is laid. The board is then transported to the site.

For example

1.31 of the resin described above is mixed with 0.781 of the hardener described above. The resin and hardener are added to a freefall mixer with 20 kg kiln dried sand, 5 kg filler and 100 g pigment powder.

While the composition is mixing a tack primer is applied to a sub-base for example with a sheepskin roller or by spraying.

The mixer contents are placed onto the prepared board and screed to a depth of about 3mm to 4 mm.

A mixture of powdered colours, hardeners and/or release agents are optionally applied for example by sieving or hand casting.

A release sheet such as of polyethylene or silicone is applied to the surface. A textured mat is pressed into place Almost any texture may be used for example roof tile or slate, stone or brick. The mat and release sheet are removed and the mixture allowed to cure preferably in a temperature controlled room. Once cured any excess powder can be washed of, the product allowed to dry and a sealer coat applied. The board with the cured composition is then transported to the site In modifications of the above process the resin mixture comprised 1 404kg of resin, 0 842kg of hardener and 02251 water This modification was particularly suitable for roof tiles

Another suitable particulate mateπal comprises 18 kg kiln dπed sand 10 kg graded filler and 0 1 kg pigment powder

In other embodiments of the invention the coating is formed and allowed to cure and then applied to a substrate Preferred uses include forming slips of bπck coloured mateπal with say red dye or bπck dust and a surface coat of sand The slips are formed to be about 3 mm thick but of size corresponding to the exposed face of a brick in a wall The bricks can be abraded to remove loose material and the slips can then be adhered to the bricks If desired the joints can then be repomted This allows a bπck wall or part thereof to be refaced without extensive cutting back If desired the slips could be adhered to a surface not of brickwork to simulate brick Other uses include forming tiles or paviours

In a preferred embodiment of the invention a fluorescent dye, such as fiuorescin sodium is incorporated in the composition Slips of this composition can be applied to kerbstones and thus make them more visible Typically application points could be danger areas such as bends or crossings

A kerb edge can be made by mixing a twin pack composition of which part A compπses 1 3 litres resin and 12 5 kg sand and part B 0 78 litre hardener and 12 5 kg sand Either or both pans contain colouring The parts are mixed on site for example using a paddle attachment on an electπc drill until a uniform colour is achieved Tack pπmer is applied to the existing kerb edges A form work is constructed around the kerb and the product trowelled into place The form work can be removed after about an hour and edging sealed When fully mixed the product is used as a conventional rendering

The composition can also be used to make a kitchen work surface Packs

A and B below are mixed until a uniform colour is achieved Pack A Pack B

0 260 kg resin 0 156 cuπng agent

0 300 kg kiln dried sand 0 300 kg kiln dried sand

0 200 kg fine graded filler 0 200 kg fine graded filler

A tack pπmer comprising 15% resin to hardener is applied with a paintbrush or roller

The composition is spread for example at a thickness of 1 to 3 mm onto the tack primer and allowed to cure Once cured sealer or varnish is applied if desired The composition of the invention can be used as a jointing and bedding material or adhesive for example for the slips of the invention

Claims

1. A method of laying a coating on a sub base comprising the steps of: i applying a mixture of epoxy resin, hardener and paniculate material to the rigid sub base, ii imprinting a pattern on the mixture by pressing a textured sheet into the mixture.

2. A method as claimed in Claim 1 wherein the epoxy resin comprises diglycidyl ethers of Bisphenol A and Bisphenol F

3 A method as claimed in Claim 1 or Claim 2 wherein the paniculate material is silica sand.

4. A method as claimed in any one of the preceding claims wherein the hardener is a cycloaliphatic amine.

5. A method as claimed in any one of the preceding claims wherein the textured sheet is flexible.

6 A method as claimed in any one of the preceding claims wherein an epoxy resin/hardener tack coat is applied to the surface prior to application of the mixture a resin hardener and particulate matter.

7 A method as claimed in any one of the preceding claims wherein a release coat is applied to the mixture prior to imprinting.

8. A method of laying a coating on a sub base substantially as described herein.

9. A coating laid by a process as claimed in any one of the preceding claims.

10. A composition obtained by mixing a) a liquid epoxy resin comprising a) A liquid epoxy resin comprising i) glycidyl ether C-13 and C-15 and ii) 4,4'-Isopropylinediphenol-epichlorohydrin and Bisphenol F- epichlorohydrin copolymer, b) a curing agent, and c) paniculate matter, and optionally d) colorant

1 1 A composition as claimed in Claim 10 wherein the curing agent comprises 4,4'-methylenebis(cyclohexanamine)polymer and optionally benzvlalcohol.