MXPA98003012A - Composition for painting the signs of traffic, resistant to deteri - Google Patents

Abstract

The present invention relates to: Aqueous compositions for painting traffic signs, resistant to deterioration, including an aqueous emulsion polymer having at least two functional groups reactive with isocyanate, an alkoxysilane having at least one functional group reactive with isocyanate, and a polyisocyanate. A method is also provided for producing a road marking, resistant to deterioration, on the surface of a road.

Description

Composition to Paint Traffic Signs, Resistant to Deterioration.

The present invention relates to coating compositions, in particular to compositions for painting traffic signs, resistant to deterioration, and to a method for producing compositions for painting traffic signs, resistant to deterioration. In particular, the present invention relates to aqueous compositions for painting traffic signs, including an aqueous emulsion polymer having at least two isocyanate-reactive functional groups, an alkoxysilane having at least two functional groups reactive with isocyanate, and a polyisocyanate. Paints for painting traffic signs are applied to roads, parking lots and the like, typically on concrete and asphalt surfaces, to instruct users and demarcate traffic lines, parking spaces and the like. While the replacement of paints made of solvent to minimize air pollution continues, aqueous compositions are sought to paint traffic signs, which have a useful level of dry film properties. One of the most important properties of the compositions for painting traffic signs is the resistance to deterioration of the dry coating under conditions of use, that is, the useful lifetime of the composition.

U.S. Patent No. 5,519,089 discloses an aqueous coating composition in two packs, including an acrylic copolymer which disperses in water and which contains alkoxysilane, and a polyisocyanate. The use of the coating composition is developed to form films that excel in strength and physical properties. The alkoxysilane content of the acrylic copolymer is fixed once the polymer is formed. In addition, the reaction of the alkoxysilane prior to film formation produces a pre-agglutinated polymer, which can inhibit effective film formation. The present invention provides a composition for painting traffic signs, resistant to deterioration, and a method for producing traffic paints resistant to deterioration. The composition has the advantage of containing three components that can independently be varied, as required, to provide useful traffic marking. According to a first aspect of the present invention, there is provided an aqueous composition for painting traffic signs, which includes an aqueous emulsion polymer having at least two functional groups reactive with isocyanate, an alkoxysilane having at least one group functional reactive with isocyanate, and a polyisocyanate. According to a second aspect of the present invention, there is provided a method for producing deterioration-resistant traffic paints, including forming an aqueous composition for painting traffic signs, by mixing an aqueous emulsion polymer having at least two functional groups reagents with isocyanate, an alkoxysilane having at least one isocyanate-reactive functional group, and a polyisocyanate; and apply the composition to a substrate. The aqueous emulsion polymer is an addition polymer having at least two functional groups reactive with isocyanate, the polymer is formed by the aqueous emulsion polymerization of the ethylenically unsaturated monomers. The aqueous emulsion polymer composition may be selected and the polymer prepared by conventional techniques known to those of ordinary skill in the art. The polymer may contain one or more of the following ethylenically unsaturated copolymerized monomers such as, for example, branched or linear C-C22 alkyl (meth) acrylate, (meth) acrylate, and / or isobornyl (meth) acrylate alkyl (meth) acrylates. Similar; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate; (met) acrylamide or substituted (meth) acrylamides; styrene or substituted styrenes; butadiene; vinyl acetate or other vinyl ester; (meth) butylaminoethyl acrylate, di (methyl) aminoethyl (meth) acrylate; a monomer containing α-unsaturated or β-unsaturated carbonyl functional groups such as fumarate, maleate, cinnamate and crotonate; and (meth) acrylonitrile. Optionally, a low level of a copolymerized acidic functional monomer such as, for example, 0-10% by weight, based on the dry weight of the acid emulsion polymer can be used. (met) acrylic, itaconic acid, crotonic acid, (meth) phosphoethyl acrylate, fumaric acid, maleic anhydride, monomethyl maleate and maleic acid.

Optionally, a low level of a multi-ethylenically unsaturated monomer such as, for example, 0-5% by weight based on the dry weight of the emulsion polymer can be used. (meth) allyl acrylate, diallyl phthalate, 1,4-butylene glycol-di (meth) acrylate, 1,6-hexanediol-di (meth) acrylate and trimethylolpropane tri (meth) acrylate, subject to maintaining a level sufficiently low of agglutination in such a way that effective film formation is not compromised. Preferred functional groups reactive with isocyanate incorporated in the aqueous emulsion polymer are the hydroxy groups and the 1,3-dicarbonyl groups. The preferred level of monomers containing hydroxy groups such as, for example, (meth) hydroxyethyl acrylate and hydorxypropyl (meth) acrylate, is from 0.1 to 40% by weight, based on the dry weight of the emulsion polymer; more preferred is from 1 to 20% by weight, based on the dry weight of the emulsion polymer; more preferred is from 3 to 8% by weight, based on the dry weight of the emulsion polymer. The preferred level of monomers containing 1,3-dicarbonyl groups such as, for example, acetoacetoxyethyl (meth) acrylate is from 0.1 to 40% by weight, based on the dry weight of the emulsion polymer; more preferred from 1 to 20% by weight, based on the dry weight of the emulsion polymer; more preferred is 8 to 12% by weight, based on the dry weight of the emulsion polymer. For the polyisocyanate, self-emulsifying polyisocyanates or those dispersed in water are preferred. Here "polyisocyanate" is understood to mean a composition carrying at least two isocyanate groups and, optionally, other functional groups. The polyisocyanate can contain aliphatic, cycloaliphatic, araliphatic and / or aromatically bound isocyanate groups. Suitable isocyanates that are dispersed in water and methods for making the aqueous dispersion of isocyanates are described in US Pat. 4,663,337; 5,075,370; 5,185,200; ,200,489 and 5,252,696; and the European patent applications nos. EP 486,881 and EP 516,277. An aqueous dispersion of a polyisocyanate carrying two to four reactive isocyanate groups is preferred. An isocyanate group index of the polyisocyanate to isocyanate-reactive groups of the aqueous emulsion polymer is preferred on a molar basis of from 1:10 to 10: 1, more preferred from 1: 3 to 3: 1, more preferred from 1: 1. to 2: 1. The alkoxysilane having at least one isocyanate-reactive functional group is any compound containing at least one Si-OC group and at least one Si-CX group, wherein X is an isocyanate-reactive group or an organic residue containing a group reagent with isocyanate. The amino, mercapto and hydroxy groups are preferred as isocyanate-reactive groups for the alkoxysilane. Preferred isocyanate-reactive alkoxysilanes include N- (2-aminoethyl) -3-aminopropyl, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropiltritoxisilano, 3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, trimetoxisililpropildietilenotriamina, 3 -aminopropylmethoxydi (trimethylsiloxy) silane, bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Preferred is 0.01 to 10% alkoxysilane by weight, based on the dry weight of the emulsion polymer; more preferred from 0.1 to 5% alkoxysilane by weight, based on the dry weight of the emulsion polymer; more preferred from 1 to 2% alkoxysilane by weight, based on the dry weight of the emulsion polymer. The aqueous composition for painting traffic signs may have no organic solvent or may contain a coalescing solvent. The composition may contain typical coating additives such as binders, fillers, defoamers, binders, catalysts, surfactants, stabilizers, anti-flocculants, dispersions or aqueous or non-aqueous solutions of non-reactive polymer (by "non-reactive polymer" herein understood to mean the polymer substantially free of the isocyanate groups or isocyanate reactants), glues, coalescents, colorants, waxes, anti-oxidants and pigments.

The aqueous composition for painting the traffic signals can be formed by mixing an aqueous emulsion polymer having at least two functional groups reactive with isocyanate, an alkoxysilane having at least one isocyanate-reactive functional group, and a polyisocyanate, using blended conventionally as mechanical stirring, such as, for example, stirring using a stirring blade driven with motor. The polyisocyanate or alkoxysilane can be previously dispersed in an aqueous or non-reactive medium or can be dispersed in the presence of the aqueous polymer dispersion. While the composition is expected to react, that is, to provide a bonded polymeric film, it is advantageous to maintain the composition as a two-pack or two-component system by mixing shortly before use. The life time in the containers is typically from five minutes to four hours at 25 ° C. It is preferred to provide a package that includes the aqueous emulsion polymer, the alkoxysilane, and, optionally, pigment and other coating additives, and a second package containing the isocyanate. The aqueous composition for painting traffic signs can be applied to roads, parking lots and the like, typically to concrete and asphalt surfaces. The composition for painting traffic signs of this invention can be applied by means of methods well known in the art such as air assisted spraying, airless spraying, plural component spraying, with brush, rubber roller and the like. After the binder composition is applied to the substrate, the composition is dried or dried. Drying to produce useful properties can take place on a convenient scale at ambient temperatures such as, for example, 0 ° C. at 35 ° C.

EXAMPLE 1. Preparation of polymer in aqueous emulsion, having at least two functional groups reactive with isocyanate (hydroxyl groups). A 760 gr. of deionized water (DI) under a nitrogen atmosphere at 90 ° C, 7.8 gr. were added with stirring. of ammonium bicarbonate dissolved in 50 gr. of water DI, 5.2 gr. of ammonium persulfate dissolved in 50 gr. of water DI, and 157 gr. of polymer seed latex (solid content of 41.5%) followed by 30 gr. of DI water to form a reaction mixture, to which the following monomer mixture was added for three hours at 81 ° C together with a 2.6 g solution. of ammonium persulfate dissolved in 100 gr. of water DI.

Monomer mixture: in grams (gr.) Water DI 680 sodium lauryl sulfate 8.7 butyl acrylate 993.6 methyl methacrylate 1030.3 hydroxyethyl methacrylate (MAHE) 108.0 methacrylic acid 28.1 At the end of the feeds, 0.1 gr. of FeS04 dissolved in 8.8 gr. of water DI, 0.01 gr. of tetrasodium salt of ethylenediamine tetraacetic acid dissolved in 0.9 gr. of water DI, 1.8 gr. of t-butylhydroperoxide (70% active ingredient) in 20 gr. of water DI and 0.6 gr. of isoascorbic acid in 20 gr. of DI water were added to the reaction product, which was then neutralized with ammonium hydroxide. The final product had a solids content of 53.4%, a Brookfield viscosity of 404 cps (axis from 3 to 60 rpm using a Brookfield viscometer model LVTD), particle size of 193 nm (the particle diameters here were measured using a meter particle Brookhaven model BI-90), and a pH of 10.4.

EXAMPLE 2 Preparation of polymer in aqueous emulsion, having at least two functional groups reactive with isocyanate (hydroxyl groups). Example 2 was prepared according to the method of example 1, except for the following monomer mixture.

Monomer mixture: in grams (gr.) Water DI 680 sodium lauryl sulfate 8.7 butyl acrylate 993.6 methyl methacrylate 1030.3 hydroxyethyl methacrylate (MAHE) 108.0 methacrylic acid 28.1 n-dodecyl mercaptan 27.0 The final product had a solids content of 53.5%, a Brookfield viscosity of 428 cps (axis from 3 to 60 rpm using a Brookfield viscometer model LVTD), particle size of 191 nm, and a pH of 10.4 EXAMPLE 3 Preparation of polymer in aqueous emulsion, having at least two functional groups reactive with isocyanate (hydroxyl groups). Example 3 was prepared according to the method of example 1, except for the following monomer mixture.

Monomer mixture: in grams (gr.) Water DI 680 sodium lauryl sulfate 8.7 butyl acrylate 864.0 methyl methacrylate 835.9 hydroxyethyl methacrylate (MAHE) 432.0 methacrylic acid 28.1 The final product had a solids content of 53.5%, a Brookfield viscosity of 624 cps (axis from 3 to 60 rpm using a Brookfield viscometer model LVTD), a particle size of 211 nm, and a pH of 10.3.

EXAMPLE 4 Preparation of polymer in aqueous emulsion, having at least two functional groups reactive with isocyanate (1,3-dicarbonyl groups) A 841 gr. of deionized water (DI) under a nitrogen atmosphere at 90 ° C was added with stirring 7.6 g. of ammonium bicarbonate dissolved in 50 gr. of water DI, 5.4 gr. of ammonium persulfate dissolved in 50 gr. of water DI and 157 gr. of polymer seed latex (solid content of 41.5%) followed by 30 gr. of DI water to form a reaction mixture, to which the following monomer mixture was added for three hours at 81 ° C together with a 2.2 g solution. of ammonium persulfate dissolved in 100 gr. of water DI.

Monomer mixture: in grams (gr.) Water DI 680 sodium lauryl sulphate 8.7 butyl acrylate 883.4 methyl methacrylate 1075.7 hydroxyethyl methacrylate (MAHE) 172.8 methacrylic acid 28.1 At the end of the feeds, 0.01 gr. of FeS04 dissolved in 9.1 gr. of water DI, 0.5 gr. of tetrasodium salt of ethylenediamine tetraacetic acid dissolved in 10 gr. of water DI, 1.8 gr. of t-butylhydroperoxide (70% active ingredient) in 20 gr. of water DI and 0.6 gr. of isoascorbic acid in 20 gr. of DI water were added to the reaction product, which was then neutralized with ammonium hydroxide. The final product had a solids content of 51.6%, a Brookfield viscosity of 100 cps (axis from 3 to 60 rpm using a Brookfield viscometer model LVTD), a particle size of 189 nm, and a pH of 9.9.

EXAMPLE 5 Preparation of polymer in aqueous emulsion, having at least two functional groups reactive with isocyanate (1,3-dicarbonyl groups). Example 5 was prepared according to the method of Example 4, except for the following.

Monomer mixture: in grams (gr.) Water DI 680 sodium lauryl sulphate 8.7 butyl acrylate 775.4 methyl methacrylate 9245 acetoacetoxyethyl methacrylate (AAEM) 432.0 methacrylic acid 28.1 The final product had a solids content of 50.7%, a Brookfield viscosity of 92 cps (axis from 3 to 60 rpm using a Brookfield viscometer model LVTD), a particle size of 192 nm and a pH of 10.4.

EXAMPLE 6 Preparation of compositions for painting traffic signs,. The compositions for painting the traffic signs, (TMC 1-7) and the comparative samples A-B were prepared according to the following formulations. The ingredients were added in the order given under laboratory mixing with light shear. After the addition of Omyacarb®-5, stirring was continued for 15 minutes before the addition of the remaining ingredients. The ingredients used in the preparation of the intermediate base paints P1-P5 are presented in Table 6.1. The intermediate base paints were then used in the preparation of the compositions for painting the traffic signs, TMC-1 to TMC-7. and the AB comparative samples; The ingredients presented in Table 6.2, were added in the order given under laboratory mixing with light shear.

TABLE 6.1. Ingredients for the intermediate base paint compositions P1-P5, for use in the compositions for painting traffic signs,.

Base paint Pl P2 P3 P4 P5 polymer in 273.4 gr. 136.7 gr. 136.7 gr. 136.7 gr. 136.7 gr. emulsion Example 1 Example 2 Example 3 Example 4 Example 5 (solids as supplied) Functional group 4.85% by weight 4.85% by weight 19.4% by weight 7.77% by weight: 19.4% by weight of polymer MAHE MAHE MAHE AAEM AAEM Victa et® 4.8 2.4 2.4 2.4 2.4 35-B Drew L-493 3.0 1.5 1.5 1.5 1.5 Ti-Puré® 60.0 30.0 30.0 30.0 30.0 R-900 Omyacarb®-5 384.0 192.0 192.0 192.0 192.0 MeOH 6.0 3.0 3.0 3.0 3.0 KP-140 3.0 1.5 1.5 1.5 1.5 Water 54.2 24.0 42.2 55.1 36.0 TABLE 6.2. Ingredients used in the preparation of compositions for painting road signs, TMC-1 to TMC-7 and comparative samples A-B.

TMC- 1 Comp. 2 3 4 5 6 Comp. 7 A B Painting lOOgr. lOOgr. lOOgr. lOOgr. lOOgr. lOOgr. lOOgr. lOOgr. lOOgr. Base Pl Pl Pl P2 P3 P3 P4 P4 P5 A0700 1.04 0 1.04 1.12 2.14 2.14 0.33 0 1.03 * XP-7063 # 2.45 2.45 4.89 2.64 10.06 3.35 2.29 2.29 5.91 * 25% on H20; aminoethylaminopropyl trimethoxysilane # 100% solids as supplied; polyisocyanate Notes: 1) All quantities are in grams unless otherwise specified. 2) Raw material suppliers: Victawet® 35-B Akzo Chemicals Inc., Chemical Division, Chicago, I 60606. A0700 United Chemical Technologies, Inc., Petrarca Silanes and Siloxanes, 2731 Bartram Road, Bristol, PA 19007. Bayhydur® XP-7063 Bayer Corp., 100 Bayer Rd., Pittsburgh, PA 15205 KP-140 FMC Corp., Phosphorous Chemicals Division, 2000 Market St., Philadelphia, PA 19103 EXAMPLE 7. Proof of the resistance to deterioration of the composition for painting traffic signs, applied. The test panels were prepared by spraying coatings of compositions to paint traffic signs, or comparative samples in very soft concrete without exposed aggregate (product from Patio Concrete Co., preconditioned panels with 200K humidity cycles in the deterioration test device Trafficometer before coating) using conventional air spray at a wet film thickness of 0.38 mm. (15 mils.). The coatings were dried at room temperature for 16 hours before the deterioration test. The deterioration test measures the durability or resistance to deterioration of a coating under accelerated conditions by repeatedly contacting the surface with tires that rolled under pressure through a curved path. The panel is subjected to cycles between wet and dry tests; the number of cumulative rotations of the Trafficometer truck in listing for each panel had an index of 1000 rotations. The Trafficometer device is described in the co-pending US provisional patent application no. 60 / 029,973. Data on deterioration are presented in Tables 7.1 and 7.2 in the form: L% W ", where L% is the percent of coating lost in an arc W" wide. The panel is subjected to cycles between the wet and dry test; the number of cumulative rotations of the Trafficometer truck in listing for each panel had an index of 1000 (k) of rotations. The non-entry indicates that no deterioration was observed in the coating.

TABLE 7.1. Results of the deterioration test.

TMC- TMC-1 Comp. A TMC-2 Comp. TMC-3 TMC-4 Pl Works- 5 MAHE 5 MAHE 5 MAHE 5 MAHE 5 MAHE 20 lity of the low MW MAHE emulsion% A0700 VA 0 1JÍ 0 1JÍ 3 NCO stoich 1 ^: 1 V? : l 3fc: l 0: 1 1JÍ: 1 1 * _: 1 humid 1.2k 5%% "3.3k 5% w 80%%" 6.4k 25% "100% W 18.8k 100%%" 30.7k 191k dry 239k wet 653k NCO stoich. = moles NCO: moles MAHE (or AAEM). % A0700 is based on resin solids.

Table 7 .2. Results of the impairment test Painting # TMC-5 TMC-6 Comp. B Comp. P4 TMC-7 Functionality 20 8 AAEM 8 AAEM 8 AAEM 20 emulsion MAHE AAEM % A0700 3 Jí 0 0 VÁ NCO stoich. Jí: l 1JÍ: 1 1JÍ: 1 0: 1 1JÍ: 1 humid 1.2k 70%% "3.3k 100% -%" 6.4k 10% w 18.8k 20% "30.7k u 191k 25% W dry 239k tt wet 653k 30% W NCO stoich. = moles NCO: moles MAHE (or AAEM). % A0700 is based on resin solids.

The TMC-1 to TMC-7 compositions of this invention exhibit superior deterioration resistance to comparatives A, B, Pl and P4.

Claims (8)

Claims

1. An aqueous composition for painting traffic signs, comprising (1) an aqueous emulsion polymer having at least two functional groups reactive with isocyanate, (2) an alkoxysilane having at least one isocyanate-reactive functional group and (3) a polyisocyanate.

2. The aqueous composition for painting the traffic signals, according to claim 1, wherein said emulsion polymer comprises from 0.1% to 40% by weight, based on the dry weight of the emulsion polymer, of ethylenically unsaturated copolymerized monomer , said monomer having at least one isocyanate reactive group.

3. The aqueous composition for painting the traffic signals, according to claim 1, wherein the isocyanate equivalents ratio to equivalents of the isocyanate-reactive functional group is from 1 to 10 to 10 to 1.

4. The aqueous composition for painting the traffic signals, according to claim 1, wherein said alkoxysilane comprises from 0.1% to 10%, the alkoxysilane having at least one hydroxy, mercapto or amino group, by weight based on the dry weight of the emulsion polymer .

A method for producing a road marking resistant to deterioration on the surface of a road, comprising: applying on said road surface a layer of an aqueous composition for painting traffic signs, comprising an aqueous emulsion polymer which has at least two functional groups reactive with isocyanate, an alkoxysilane having at least one isocyanate-reactive functional group, and a polyisocyanate; and drying or allowing said aqueous composition to dry to paint the traffic signs,.

The method according to claim 5, wherein said emulsion polymer comprises from 0.1% to 40% by weight, based on the dry weight of the emulsion polymer, of an ethylenically unsaturated copolymerized monomer, said monomer having at least one reactive group with isocyanate.

7. The method according to claim 5, wherein the isocyanate equivalent index to equivalents of the isocyanate-reactive functional group is from 1 to 10 to 10 to 1. The method according to claim 5, wherein said alkoxysilane comprises from 0.1% to 10% of an alkoxysilane having at least one hydroxy, mercapto or amino group, by weight based on the dry weight of the emulsion polymer.