REACTIVE RESIN SEALING FOR LOW-CONTAMINANT COLD PLASTIC MARKINGS

Abstract

The present invention encompasses a novel soil-repellent reactive resin seal for markings or coating of areas of ground or trafficways, for example roads, based on cold plastic. Compared to established prior art systems, this sealing leads to reduced adhesion of soil, especially in hot and/or dry, dusty environments. Thus, the marking retains better visibility than conventional markings, even in dry, hot regions. Otherwise, the marking sealed in accordance with the invention has comparable mechanical properties to the prior art.

Claims

1: A two-layer road marking or ground coating, comprising: a lower layer which is a cured 2-pack (meth)acrylate-based reactive resin formulation that comprises, prior to curing, in one or both packs, at least 0.3% by weight of crosslinker, at least 4% by weight of (meth)acrylate monomers, at least 2% by weight of prepolymers, and, optionally, a further additive, and a second upper layer, which is a cured reactive resin seal comprising: up to 50% by weight of at least one of a pigment, a filler, and an additive, and at least 50% by weight of a cured (meth)acrylate resin comprising at least 50% by weight of repeat units based on (meth)acrylates and having a glass transition temperature T.sub.g of at least 60° C.

2: The two-layer road marking or ground coating according to claim 1, wherein the second layer comprises at least 80% by weight of the cured (meth)acrylate resin and not more than 20% by weight of at least one of a pigment, a filler, and an additive.

3: The two-layer road marking or ground coating according to claim 1, wherein the cured (meth)acrylate resin in the second layer has a glass transition temperature T.sub.g of at least 70° C.

4: The two-layer road marking or ground coating according to claim 1, wherein the reactive resin seal, prior to curing to give the second layer, comprises: 10% to 35% by weight of at least one of a poly(meth)acrylate and a polyester, 40% to 80% by weight of a monomer, which comprises at least one of a (meth)acrylate and a monomer partly copolymerizable with a (meth)acrylate, 1% to 10% by weight of crosslinker, 0% to 5% by weight of a tertiary aromatic amine, 0% to 25% by weight of at least one of a pigment and a filler, 1% to 10% by weight of at least one additive selected from the group consisting of a plasticizer, a paraffin, a UV absorber, a stabilizer, and a blueing agent, and 0.1% to 5% by weight of one or more initiators, which are combined only shortly before application with the tertiary amine in the mixture, where the poly(meth)acrylate and the polyester have a glass transition temperature Tg of at least 70° C. and the monomer component comprise at most 50% by weight of those monomers which, in the fully polymerized state, have a glass transition temperature of at least 60° C.

5: The two-layer road marking or ground coating according to claim 4, wherein the reactive resin seal, prior to curing, comprises: 15% to 25% by weight of a poly(meth)acrylate, 60% to 75% by weight of a (meth)acrylate having C1-C4-alkyl radicals, 2% to 8% by weight of at least one di- and/or tri(meth)acrylate, 0.4% to 4% by weight of a tertiary aromatic amine, 0% to 10% by weight of at least one of a pigment and a filler, 2% to 8% by weight of an additive, and 0.2% to 4% by weight of at least one of dilauroyl peroxide and dibenzoyl peroxide, where the poly(meth)acrylate and the fully polymerized (meth)acrylate each have a glass transition temperature Tg of at least 70° C.

6: The two-layer road marking or ground coating according to claim 1, wherein the two packs of the reactive resin for production of the first layer together comprise: 0.5% by weight to 30% by weight of crosslinker, 10% by weight to 96.1% by weight of a (meth)acrylate and optionally a component copolymerizable with a (meth)acrylate, 4% by weight to 20% by weight of a urethane (meth)acrylate, 3% by weight to 45% by weight of a prepolymer, 0.1% by weight to 5% by weight of at least one tertiary amine, 1% by weight to 25% by weight of core-shell particles, 0.5% by weight to 10% by weight of at least one initiator, where the initiator(s) and the tertiary amine, prior to mixing, are present in separate packs of the 2-pack system, and optionally further auxiliaries.

7: The two-layer road marking or ground coating according to claim 6, wherein the two packs of the reactive resin of the first layer together comprise: 2% by weight to 20% by weight of at least one of a di-(meth)acrylate, a tri-(meth)acrylate, and a tetra(meth)acrylate, 30% by weight to 80% by weight of a (meth)acrylate and optionally a component copolymerizable with a (meth)acrylate, 0% by weight to 20% by weight of a urethane (meth)acrylate, 15% by weight to 40% by weight of at least one of a poly(meth)acrylate and a polyester, 0.4% by weight to 2.0% by weight of at least one tertiary amine, 0% by weight to 20% by weight of core-shell particles, 1% by weight to 7% by weight of initiator, where the initiator and the tertiary amine are present in separate packs of the 2-pack system, and optionally further auxiliaries.

8: The two-layer road marking or ground coating according to claim 7, wherein the reactive resin of the first layer is halogen-free, and the reactive resin comprises: 3% by weight to 15% by weight of a dimethacrylate, 30% by weight to 40% by weight of a (meth)acrylate and optionally a component copolymerizable with a (meth)acrylate, 0% by weight to 20% by weight of a urethane (meth)acrylate, 20% by weight to 30% by weight of a poly(meth)acrylate, 0.2% to 0.8% by weight of a tertiary amine, 0% by weight to 15% by weight of core-shell particles comprising a polymethacrylate, 1.5% by weight to 5% by weight of at least one of dilauroyl peroxide and dibenzoyl peroxide as initiator and optionally further auxiliaries.

9: The two-layer road marking or ground coating according to claim 1, wherein the first, lower layer comprises: between 15% and 55% by weight of cured reactive resin, 0.15% by weight to 25% by weight of an inorganic pigment, 0% by weight to 5% by weight of at least one of a stabilizer and an additive, and 20% by weight to 80% by weight of at least one of a mineral and a polymeric filler.

10: The two-layer road marking or ground coating according to claim 1, wherein the second layer at 23° C. has a tensile strain at break, measured to DIN 527, of less than 10%, and the (meth)acrylate resin of the second layer, prior to application, has a viscosity at 23° C., measured to DIN 53015, of between 50 and 500 mPas.

11: The two-layer road marking or ground coating according to claim 10, wherein the tensile strain at break is less than 5%, and the viscosity of the (meth)acrylate resin prior to application is between 50 and 250 mPas.

12: The two-layer road marking or ground coating according to claim 1, wherein the second layer has a thickness of not more than 500 μm.

13: The two-layer road marking or ground coating according to claim 12, wherein the second layer has a thickness of not more than 200 μm.

14: A method for laying a heat-resistant and soil-repellent road marking, the method comprising: a) mixing the components of a reactive resin according to claim 6, b) applying the reactive resin to the road surface within the pot life of the reactive resin, c) optionally mixing components for production of the second layer, d) applying the reactive resin from said c) mixing to the first layer within the pot life of the reactive resin, and e) optionally sprinkling with glass beads, wherein said c) mixing can be conducted before, in parallel with or after said a) mixing and said b) applying, said e) optionally sprinkling can be conducted before, in parallel with or after said d) applying, and the components of said c) mixing comprise: 10% to 35% by weight of at least one of a poly(meth)acrylate and a polyester, 40% to 80% by weight of a monomer, which comprises at least one of a (meth)acrylate and a monomer partly copolymerizable with a (meth)acrylate, 1% to 10% by weight of crosslinker, 0% to 5% by weight of a tertiary aromatic amine, 0% to 25% by weight of at least one of a pigment and a filler, 1% to 10% by weight of at least one additive selected from the group consisting of a plasticizer, a paraffin, a UV absorber, a stabilizer, and a blueing agents, and 0.1% to 5% by weight of one or more initiators, which are combined only shortly before application with the tertiary amine in the mixture, where the poly(meth)acrylates and/or polyesters have a glass transition temperature Tg of at least 70° C. and the monomer component comprise at most 50% by weight of those monomers which, in the fully polymerized state, have a glass transition temperature of at least 60° C.

14: The method according to claim 14, wherein said c) mixing is carried out, and the application of the second layer in said d) applying follows performance of said c) mixing and curing of the first, lower layer, with optional sprinkling of sprinkling agents into at least one of the two layers within the respective pot life.

14: The method according to claim 14, wherein the application of the second layer in step said d) applying which does not itself contain any initiator is effected without performance of said c) mixing within the pot life of the first, lower layer, with optional sprinkling of sprinkling agents into at least one of the two layers within the pot life thereof.

16: The method according to claim 16, wherein that the laying is effected by machine or by a vehicle or device, with initial application of the first, lower layer from one or more outlet devices to the road surface or other outer surface according to said b) applying, followed within the pot life of the first layer by spray application of the second layer without initiator by means of one or more outlet devices according to said d) applying to the first, as yet uncured layer, and with optional laying of glass beads from one or more optional outlet devices onto one of the two layers according to said c) optionally sprinkling within the pot life of the layer in question, wherein the three outlet devices are not more than 2 m apart in movement direction and are operated simultaneously.

Description

EXAMPLES

[0098] Preliminary Stage 1 First Layer of the Road Marking

[0099] A 2-pack cold plastic material for a conventional one-layer road marking is formulated as follows on the basis of a 2-pack reactive resin binder DEGAROUTE 465 from Evonik Industries AG. This reactive resin contains between 3% and 15% by weight of crosslinker, between 30% and 40% by weight of MMA, between 15% and 40% by weight of n-butyl acrylate and between 0.5% and 2.0% by weight of a mixture of two tertiary amines:

TABLE-US-00001 TABLE 1 Cold plastic formulation Reactive resin:  20% by weight of DEGAROUTE 465 Dispersing additive: 0.1% by weight of Disperbyk 163 Rheology additive: 0.1% by weight of Disperbyk D 410 Rheology additive: 0.1% by weight of Bentone 27 Pigment:  10% by weight of titanium dioxide Fine filler:  20% by weight of Omyacarb 15GU Coarse filler:  25% by weight of Cristobalite M72 Premix beads:  25% by weight of glass beads (50-250 μm)

[0100] The cold plastic material is mixed with 2% by weight of curing agent powder from Evonik Industries AG (benzoyl peroxide, 50% in phthalate) and applied to a surface at 23° C. by means of a line marker with gap width 2 mm, the pot life being 10 minutes and the curing time 30 minutes.

[0101] When this road marking is used, especially on busy tarmac roads and with persistently dry, hot weather conditions with daytime temperatures above 35° C., this conventional one-layer road marking becomes highly soiled and cannot be cleaned again by water (for example in the form of rain).

Comparative Example 1

Noninventive Two-Layer Road Marking

[0102] First of all, the cold plastic material from Preliminary Stage 1 is applied as described to the surface as the first layer together with 2% by weight of curing agent powder. After this first layer has cured, i.e. after 30 minutes, a noninventive reactive resin seal is applied to the cured first layer as the second layer in the form of a mixture of 4% by weight of curing agent powder and 96% by weight of pure DEGAROUTE 465 2-pack reactive resin in a layer of thickness 200 μm by means of a roller.

[0103] DEGAROUTE 465 is a 2-pack reactive resin having a dynamic viscosity of 200 mPas measured at 23° C. to DIN 53018 by means of Brookfield DV-II with 1/30 rpm spindle, which has the following properties after curing and conditioning for 72 h:

[0104] Glass transition temperature: <30° C. (DIN EN ISO 11357-1)

[0105] Tensile strain at break: 230% (DIN EN ISO 527 at 23° C.)

[0106] Tensile strength: 7 MPa (DIN EN ISO 527 at 23° C.)

[0107] This noninventive two-layer road marking becomes highly soiled under the use conditions specified in Example 1 and cannot be cleaned again by water (for example in the form of rain).

Example 1

Inventive Two-Layer Road Marking and Inventive Reactive Resin Seal

[0108] For production of the inventive reactive resin seal, the polymer component used is a suspension polymer consisting exclusively of methyl methacrylate (MMA) monomer units and having a molar mass of 80 000 g/mol (Mw) (determined by SEC against PMMA standards) and a glass transition temperature T.sub.g of 116° C. (determined to DIN EN ISO 11357-1).

[0109] This polymer component was dissolved in methyl methacrylate, and mixed with the other constituents according to the following composition (see Table 2):

TABLE-US-00002 TABLE 2 Polymer   22% by weight of suspension polymer component: Monomer 63.5% by weight of methyl methacrylate component: Crosslinker:   5% by weight of butane-1,4-diol dimethacrylate Accelerator:   2% by weight of N,N-bis-(2-hydroxypropyl)-p-toluidine Plasticizer:   5% by weight of tributyl O-acetylcitrate Additives:  2.5% by weight

[0110] This mixture, i.e. the liquid reactive resin seal, at 23° C. has a dynamic viscosity of 80 mPas (measured to DIN 53018 by means of Brookfield DV-II with 1/30 rpm spindle).

[0111] By mixing the reactive resin seal with 1% by weight of initiator (benzoyl peroxide, curing agent powder from Evonik Industries AG), curing of the seal is induced at room temperature, with a pot life of 9 minutes and a curing time of 27 minutes, and the cured reactive resin seal after conditioning for 72 h has the following properties:

[0112] Glass transition temperature: 74° C. (DIN EN ISO 11357-1)

[0113] Tensile strain at break: 2% (DIN EN ISO 527 at 23° C.)

[0114] Tensile strength: 40 MPa (DIN EN ISO 527 at 23° C.)

[0115] Tensile modulus of elasticity: 2800 MPa (DIN EN ISO 527 at 23° C.)

[0116] For production of the inventive two-layer road marking, the cold plastic material from Preliminary Stage 1 is applied as described therein to the surface as the first layer together with 2% by weight of curing agent powder. After this first layer has cured, i.e. after 30 minutes, inventive reactive resin seal is applied to the cured first layer as the second layer in the form of a mixture of 1% by weight of curing agent powder and 99% by weight of pure 2-pack reactive resin (composition according to Table 2) in a layer of thickness 150 μm by means of a roller, and cures to give a tack-free surface after about 30 minutes.

[0117] When used on busy tarmac roads and with persistently dry, hot weather conditions with daytime temperatures above 35° C., this inventive two-layer road marking becomes less soiled compared to conventional one-layer markings or the noninventive two-layer marking from Comparative Example 1, and can be cleaned again better by water (for example in the form of rain).

Example 2

Inventive Two-Layer Road Marking

[0118] For production of this inventive two-layer road marking, the cold plastic material from Example 1 is again applied as described therein to the surface as the first layer together with 2% by weight of curing agent powder. Within 2 minutes after the application of the first layer, i.e. before the pot life of the first layer has elapsed, the inventive reactive resin seal according to Example 1 is sprayed onto the still-fresh first layer with a layer thickness of 200 μm as the second layer without addition of initiators in an airless spraying method with a 1-pack spraying machine at pressure 180 bar. The second layer which does not itself contain any initiator is initiated exclusively via the first layer beneath. After 30 minutes, the surface of the two-layer marking has cured to give a tack-free surface.

[0119] In this process, exclusively non-initiated reactive resin seal is stored and processed in the machine, and so it is possible to use conventional 1-pack spraying machines, and the risk of polymerization of the seal in the reservoir vessel in the machine or in the spraying machine itself is avoided.

[0120] The marking produced by this application method features low soil uptake and good cleaning properties, like the marking produced by the application method specified in Example 1.

Example 3

[0121] A conventional 2-pack cold (sprayable) plastic for the lower layer is formulated as follows on the basis of a 2-pack reactive resin binder DEGAROUTE 680 from Evonik Industries AG:

TABLE-US-00003 TABLE 3 Cold sprayable plastic formulation Reactive resin:   35% by weight of DEGAROUTE 680 Dispersing additive:  0.5% by weight of Disperbyk 163 Rheology additive:  0.1% by weight of Disperbyk D 410 Pigment:   10% by weight of titanium dioxide Fine filler: 54.4% by weight of Omyacarb 15GU

[0122] This cold plastic material at 23° C., after 2% by weight of curing agent powder has been mixed in, has a pot life of 1 min and a curing time of 2.5 minutes, and corresponds to a composition as per claims 6 and 7.

[0123] This cold plastic material is mixed automatically in an airless 2-pack spraying machine with 2% by weight of Benox L 40 LV liquid curing agent from United Initiators (benzoyl peroxide 40% dispersion) and sprayed on in an airless method at 120 bar from a first spray nozzle onto the surface as the first layer with a thickness of 600 μm, while moving the machine forward at a speed of 7 kilometres per hour. Mounted on the same spraying machine, viewed counter to the running direction, at a distance of 60 cm after the airless spray nozzle, is an airspray nozzle with which the inventive reactive resin seal from Example 1 is sprayed onto the fresh first layer as the second layer with a thickness of 125 μm without addition of an initiator with atomizer air pressure 3 bar. The second layer is again initiated exclusively via the first layer beneath. The surface of this inventive road marking has cured tack-free within less than 10 minutes.

[0124] The inventive road marking becomes much less soiled on busy tarmac roads and with persistently dry, hot (daytime temperatures above 35° C.) weather conditions compared to conventional one-layer road marking, and can be cleaned again by water (for example in the form of rain).