Low odor reactive resin composition

Abstract

The present invention is a composition comprising a) an acrylic or styrene-acrylic resin having a Tg in the range of from 30 °C to 120 °C; and b) one or more monomers of Formula 1: Formula 1 where R is:; where R1 is C1-C4-alkyl; x is from 1 to 200; and the dashed line is the point of attachment to the oxymethylene group of Formula 1; wherein, based on the weight of the composition, the combined concentrations of the one or more monomers of Formula 1 are in the range of from 50 to 85 weight percent, and the concentration of the resin is in the range of from 5 to 40 weight percent; with the proviso that when the one or more monomers of Formula 1 is solely the monomer of Formula 1b, the composition further comprises from 5 to 15 weight percent of a plasticizer. The composition of the present invention is useful in 2K cold plastic traffic formulations.

Description

[0001] Low Odor Reactive Resin Composition

[0002] Background of the Invention

[0003] The present invention relates to a low odor reactive resin composition. Traffic road markings play an essential part in promoting safe travel for commuters, primarily by indicating which road (or side of the road) to use, and where passing is allowed or not allowed. As roadways are rebuilt and refinished, more durable means for marking roads are being sought. Currently, two-component (2K) cold plastic formulations are primarily being used to mark roads. These formulations are typically prepared with a combination of acrylic resin, reactive acrylic monomers, pigments, and additives; just before this blend is applied to a road, a peroxide is added to the catalyze the polymerization of the acrylic monomers. The advantage of these 2K systems include significant dry-film thickness of the consequent cured film, good adhesion to asphalt and concrete substrates, as well as glass beads and other retroreflective materials, and durability. Furthermore, the formulation can be applied at very cold temperatures, which extends the striping season.

[0004] Nevertheless, state-of-the-art 2K road marking technology suffers from the use of odoriferous, volatile, and often flammable monomers, such as methyl methacrylate and butyl acrylate, which require special care in handling and storing. Moreover, the application of these formulations at relatively high temperatures causes the volatile monomers to evaporate, thereby adversely impacting the composition of the cured material. Accordingly, it would be an advantage in the art of road marking formulations to discover reactive monomers that overcome these shortcomings.

[0005] Summary of the Invention

[0006] The present invention addresses a need in the art by providing a composition comprising a) an acrylic, styrene-acrylic, or urethane- acrylic resin having a Tgin the range of from 30 °C to 120 °C; and b) one or more monomers of Formula 1 :

[0007] Formula 1 where R is:

[0008] Formula la Formula lb Formula 1c where R1is Ci-C4-alkyl; x is from 1 to 200; and the dashed line is the point of attachment to the oxy methylene group of Formula 1; wherein, based on the weight of the composition, the combined concentrations of the one or more monomers of Formula 1 are in the range of from 50 to 85 weight percent, and the concentration of the resin is in the range of from 5 to 40 weight percent; with the proviso that when the one or more monomers of Formula 1 is solely the monomer of Formula lb, the composition further comprises from 5 to 15 weight percent of a plasticizer. The composition of the present invention is useful in 2K cold plastic traffic formulations.

[0009] Detailed Description of the Invention

[0010] The present invention is a composition comprising a) an acrylic, styrene-acrylic, or urethane-acrylic resin having a Tgin the range of from 30 °C to 120 °C ; and b) one or more monomers of Formula 1 :

[0011] Formula la Formula lb Fonnula 1c where R1is Ci-C4-alkyl; x is from 1 to 200; and the dashed line is the point of attachment to the oxymethylene group of Formula 1; wherein, based on the weight of the composition, the combined concentrations of the one or more monomers of Formula 1 are in the range of from 50 to 85 weight percent, and the concentration of the resin is in the range of from 5 to 40 weight percent; with the proviso that when the one or more monomers of Formula 1 is solely the monomer of Formul 1 b, the composition further comprises from 5 to 15 weight percent of a plasticizer.

[0012] The resin has a Tgof from 30 °C or from 40 °C, to 120 °C or to 100 °C, or to 80 °C or to 60 °C, as calculated by the Fox equation. The resin is an acrylic, a styrene-acrylic, or a urethane- acrylic resin, with acrylic resins being preferred. The resin, which is a solvent- free solid, can be prepared by solution polymerization of one or more suitable monomers, followed by solvent removal, by any of several methods well known in the art. Examples of suitable monomers include styrene, acrylate, or methacrylate monomers such as methyl methacrylate, styrene, ethyl acrylate, n-butyl methacrylate, isobutyl methacrylate, / -butyl methacrylate, benzyl methacrylate, and isobomyl methacrylate. Commercial examples of suitable resins include PARALOID™ B-56 Acrylic Polymer, PARALOID™ B-66 Acrylic Polymer, and PARALOID™ B-99N Acrylic Polymer. (PARALOID is a trademark of The Dow Chemical Company or its Affiliates.) The concentration of the resin is preferably in the range of from 5 or from 15 or from 20 or from 24 weight percent, to 40 or to 30 or to 32 weight percent, based on the weight of the composition.

[0013] The concentration of the one or more monomers of Formula 1 is in the range of from 50 or from 55 or from 60 or from 65 weight percent, to 85 or to 80 or to 75 weight percent, based on the weight of the composition. Preferably, R1is Ci-C3-alkyl, and more preferably methyl or ethyl; x is from 1 or from 2 or from 5, to 200 or to 100 or to 50 or to 20 or to 10. The monomers may be used alone or in combination. For example, in a combination of monomers of Formula lb and 1c, the concentration of the monomer of Formula lb is preferably in the range of from 30 to 60 or to 50 weight percent, and the concentration of the monomer of Formula 1c is preferably in the range of from 20 weight percent to 50 or to 40 weight percent, based on the weight of the composition. Similarly in a combination of monomers of Formula la and 1c, the concentration of the monomer of Formula la is preferably in the range of from 30 to 60 or to 50 weight percent, and the concentration of the monomer of Formula 1c is preferably in the range of from 20 weight percent to 50 or to 40 weight percent, based on the weight of the composition. Preferably, the composition comprises less than 10, more preferably less than 5, and most preferably less than 1 weight percent of an ancillary monomer not of Formula 1, more particularly, less than 1 weight percent of tridecyl methacrylate.

[0014] The composition advantageously further comprises an oxidant that promotes the polymerization of the one or more monomers of Formula 1. The concentration of the oxidant is preferably in the range of from 0.2 or from 0.5 or from 0.7 weight percent, to 5 or to 4 or to 2 weight percent, based on the weight of the composition. An example of a class of oxidants suitable for promoting polymerization is a peroxide such as benzoyl peroxide.

[0015] The composition further advantageously comprises a wax that creates a barrier to oxygen, thereby promoting the desired free radical polymerization. The concentration of the wax is preferably in the range of 0.2 or from 0.5 weight percent, to 3 or to 2 weight percent, based on the weight of the composition. The wax is preferably a paraffin wax, for example Hywax 5603 paraffin wax.

[0016] In addition, the composition advantageously further comprises other additives including a crosslinker such as triethylene glycol dimethacrylate; from 0.2 to 4 weight percent, based on the weight of the composition, of an accelerator such as A,2V-bis(2-hydroxypropyl)-p-toluidine, N-(2-hydroxyethyl)-N-methyl-4-toluidine, A-phenyldiethanolamine, A,A-Bis(2-hydroxyethyl)- p-toluidine, or a cobalt salt such as cobalt(II) 2-ethylhexanoate; an inhibitor such as 2,4- dimethyl-6-t-butylphenol; and a plasticizer such as tributyl O-acetyl citrate. The composition of the present invention is a non-volatile, low-odoriferous precursor to a paint formulation suitable for traffic marking. The paint formulation comprises the composition of the present invention and an opacifying pigment such as TiO , a rheology additive, and a filler including CaCCh, glass beads, and silica. Surprisingly, it has been discovered that tack-free coatings from the composition can be formed in less than 30 minutes.

[0017] Examples

[0018] General Procedure for the Preparation of a Peroxide Cured Reactive Resin Formulation

[0019] A. Reactive resins were prepared by adding triethylene glycol dimethacrylate; accelerator (jV,A-bis(2-hydroxypropyl)-p-toluidine); Hywax 5603 Paraffin wax; one or more monomers of Formula 1; 2, 4-di methyl -6- / -butylphenol: and a stir bar to a glass container. Solid PARALOID B-66 Acrylic Resin was slowly added with stirring. The vial was loosely capped and heated to 60 °C until the mixture was completely homogenous. The vial was then cooled to room temperature. B. A portion of the reactive resin was added to a container, followed by addition of benzoyl peroxide (BPO). The mixture was agitated for 60 s, after which time a portion of the resin was applied as a 2-mm thick film to a substrate, and the tack- free time was recorded.

[0020] General Procedure for Peroxide Cured Filled Paint Formulation

[0021] Formulated pigmented paints were made in a Plastic Max 100 tall speed mixer cup using a DAC 150 Speed mixer. The reactive resin formulation of Part A was added along with Byk 410 Liquid Rheology Additive, TEGO Dispers 670 Dispersing Agent, and Bentone 27 Rheology Additive. The contents were mixed for 1 min at 2000 rpm. TiOz, calcium carbonate, and silica were added, and the contents were mixed with a wooden stir stick before being placed in speed mixer for 5 min at 1600 rpm. Paints we allowed to set overnight to observe any thickening or separation. Benzoyl peroxide (BPO) was added to the formulated pigmented paint in a vessel equipped with a temperature probe, thereby generating heat.

[0022] Tack-Free Time Measurements

[0023] Tack- free time is the time elapsed from the addition of the BPO to the reactive resin to formation of a tack-free film, which is a film sufficiently cured so that observable amounts of resin did not transfer to a gloved finger after application of a light touch to the coating. Tack-free times were measured for formulations prepared using one or more monomers of Formula 1 , as shown in Table 1. la refers to the monomer of Formula la; lb refers to the monomer of Formula lb, which is tetrahydrofurfurylmethacrylate; lei refers to Formula 1c, where R1is methyl and x is 1; leg refers to Formula 1c, where R1is methyl and x is 8; lceirefers to Formula 1c, where R1is ethyl and x is 1; TDMA refers to n-lridecy I methacryl ate, which is a comparative monomer; BA refers to n-buty I acrylate; MMA refers to methyl methacrylate; wax refers to Hywax 5603 Paraffin Wax; and BPO% refers to the weight percent of Perkadox GB-50X benzoyl peroxide, 50% active. Monl refers to a first monomer; Mon2 refers to a monomer different from Monl; MonA% and MonB% refer to the weight percents of the monomer A and B, respectively;

[0024] Resin% refers to the weight percent of PARALOID B-56 Acrylic Resin; Wax% refers to the weight percent of the wax. All weight percents are based on the weight of the composition. All examples and comparative examples included triethylene glycol dimethacrylate (1.94-2.10 wt%) and N, Wbis(2-hydroxypropyl)-p-toluidine (1-1.09 wt%). TF(t) refers to the time required for the coatings prepared from the samples to be free of tack. Table 1 - Tack-free Times for Reactive Resins aExample 4 included 10 wt% tributyl O-acetyl citrate;bCEx 2 further included 0.06 wt% Topanol O Inhibitor.

[0025] The results show that non-volatile and low-odoriferous Formula 1 monomers in curable reactive resins provide tack- free coatings in a time frame comparable to reactive resins that contained the odoriferous and volatile monomers MMA and BA. The results also shows that a combination of

[0026] Formula lb and TDMA in a reactive resin, though non-volatile and low in odor, did not give acceptable tack-free times. It has also been discovered that reactive resins prepared using the monomer of Formula lb as the only monomer of Formula 1 require from about 5 to 15 weight percent of a plasticizer to reduce the Shore D hardness of the resin to an acceptable level (< 65). Viscosity Stability Measurements

[0027] Two cold plastic formulation samples were compared for viscosity stability: one containing MMA and BA as monomers A and B (CEx 1); and one containing monomers of Formulas lb and leg as monomers A and B (Ex 2). Each formulation was loaded onto a rheometer equipped with parallel plate geometries and heated to 60 °C. After the samples were equilibrated for 30 s, an initial viscosity (qo) was measured. The samples were then maintained at 60 °C for 5 min, and viscosities (r|f) was measured again. Table 2 illustrates the change in viscosity for incumbent formulation and a formulation of the present invention. Table 2 - Effect of Temperature on Viscosity for Curable Cold Plastics

[0028] The data show a significant increase in viscosity for the incumbent sample, presumably arising from monomer devolatilization; in contrast, the viscosity of the samples made using the monomers of Formula lb and Formula 1c remained unchanged. Accordingly, unlike the incumbent cold plastic formulation, the data support the contention that formulations of the present invention can be applied to a substrate at elevated temperatures without loss of monomer.

Claims

Claims:

1. A composition comprising a) an acrylic, styrene-acrylic, or urethane-acrylic resin having a Tgin the range of from 30 °C to 120 °C; and b) one or more monomers of Formula 1:Formula la Formula lb Formula 1c where R1is Ci-C4-alkyl; x is from 1 to 200; and the dashed line is the point of attachment to the oxymethylene group of Formula 1; wherein, based on the weight of the composition, the combined concentrations of the one or more monomers of Formula 1 are in the range of from 50 to 85 weight percent, and the concentration of the resin is in the range of from 5 to 40 weight percent; with the proviso that when the one or more monomers of Formula 1 is solely the monomer of Formula lb, the composition further comprises from 5 to 15 weight percent of a plasticizer.

2. The composition of Claim 1 which further comprises, based on the weight of the composition, from 0.2 to 3 weight percent of a wax, and from 0.2 to 4 weight percent of an accelerator.

3. The composition of Claim 2 which comprises a combination of the monomers of Formula lb and Formula 1c; wherein x is in the range of from 1 to 50 and R1is Ci-Ci-alkyk wherein, based on the weight of the composition, the combined concentrations of the monomers of Formula lb and Formula 1c are in the range of from 60 to 80 weight percent and the concentration of the resin is in the range of from 15 to 30 weight percent; wherein the wax is a paraffin wax, theaccelerator is jV,jV-bis(2-hydroxypropyl)-p-toluidine, N-(2-hydroxyethyl)-N-methyl-4-toluidine, 7V-phenyldiethanolamine, ,V-Bis(2-hydroxyethyl )- / >-toluidine, or cobalt(II) 2-ethylhexanoate; and the resin is an acrylic resin.

4. The composition of Claim 3 wherein, based on the weight of the composition, the concentration of the monomer of Formula lb is in the range of from 30 to 60 weight percent, and the concentration of the monomer of Formula 1c is in the range of from 20 to 40 weight percent.

5. The composition of Claim 4 wherein, based on the weight of the composition, the concentration of the paraffin wax is in the range of 0.5 to 2 weight percent and the concentration of the peroxide is in the range of from 0.7 to 3 weight percent; wherein the peroxide is benzoyl peroxide; wherein x is in the range of from 1 to 20 and R1is methyl or ethyl.

6. The composition of Claim 2 which comprises a combination of the monomers of Formula la and Formula 1c; wherein x is in the range of from 1 to 50 and R1is Ci-C3-alkyl; wherein, based on the weight of the composition, the combined concentrations of the monomers of Formula 1 a and Formula 1c are in the range of from 60 to 80 weight percent and the concentration of the resin is in the range of from 15 to 30 weight percent; wherein the wax is a paraffin wax, the oxidant is a peroxide, and the resin is an acrylic resin.

7. The composition of Claim 6 wherein, based on the weight of the composition, the concentration of the monomer of Formula la is in the range of from 30 to 60 weight percent, and the concentration of the monomer of Formula 1 c is in the range of from 20 to 40 weight percent.

8. The composition of Claim 7 wherein, based on the weight of the composition, the concentration of the paraffin wax is in the range of 0.5 to 2 weight percent, and the concentration of the peroxide is in the range of from 0.7 to 3 weight percent; wherein the peroxide is benzoyl peroxide; and wherein x is in the range of from 1 to 20 and R1is methyl or ethyl.

9. The composition of Claim 2 which comprises, based on the weight of the composition, from 60 to 80 weight percent of the monomer of Formula la, and 15 to 30 weight percent of the resin; wherein the wax is a paraffin wax and the oxidant is a peroxide.

10. The composition of Claim 2 which comprises, based on the weight of the composition, from 60 to 80 weight percent of the monomer of Formula lb; and 15 to 30 weight percent of the resin; wherein the wax is a paraffin wax and the oxidant is a peroxide.

11. The composition of Claim 10 which comprises a plasticizer which is tributyl O-acetyl citrate.

12. The composition of Claim 11 which comprises less than 1 weight percent of tridecyl methacrylate.

13. The composition of Claim 2 which comprises, based on the weight of the composition, from60 to 80 weight percent of the monomer of Formula 1c; and 15 to 30 weight percent of the resin; wherein the wax is a paraffin wax and the oxidant is a peroxide.

14. The composition of Claim 2 which further comprises a dispersing agent, a rheology additive, an opacifying pigment, a filler, a crosslinker, and an oxidant that promotes the polymerization of the one or more monomers of Formula 1 ; wherein the wax is a paraffin wax, and the oxidant is a peroxide.

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