Microbial resistant dispersants

Abstract

The present invention relates to a composition comprising water, a carboxylic acid functionalized dispersant and a compound of formula I: wherein R, R1, x and y are as defined herein. The compositions of the present invention are useful as biocide-free additives to pre-coating formulations. # imgabs0 #

Description

Background Art

[0001] The present invention relates to microbial resistant dispersants and, more particularly, to dispersants having preservative properties in the absence of biocides.

[0002] Isothiazolinones are commonly used as preservatives in a variety of consumer products, including architectural coatings. However, isothiazolinones are known skin sensitizers and are under increasing scrutiny from regulatory agencies for use in a variety of consumer products. In 2016, the European Commission issued a directive restricting the use of methylisothiazolinone (MIT) in most consumer products, including house paints. By 2021, the EU has decided that the final formulation of these products will not be allowed to contain more than 15 ppm of MIT. These strict restrictions are a challenge for coating formulators who want to control the amount of biocide in the final product. Therefore, it would be an advance in the field of architectural coatings to find a biocide-free solution for preserving additives used in coating formulations. Summary of the invention

[0003] The present invention solves the need in the art by providing a composition comprising, based on the weight of the composition, a) 50 wt % to 90 wt % water, b) 9 wt % to 45 wt % of a carboxylic acid functionalized dispersant; c) and 0.5 wt % to 10 wt % of a compound of formula I:

[0004]

[0005] wherein each R is independently H, methyl or ethyl;

[0006] R 1 =–R 2 -NR 3 -(CH2CH2O) z -H; or –C6-C 18 -alkyl; or –C(CH3)2R 4 ;

[0007] x is 1 to 40; y is 0 to 39; and z is 0 to 39;

[0008] The premise is that when y is 0, R 1 Yes –C(CH3)2R 4 ; and when y is 1 to 39, R 1 Yes – R 2 -NR 3 -(CH2CH2O) y -H or –C6-C 18 -alkyl;

[0009] R 2is –CH2CH2CH2– or –CH(CH3)CH2– or –CH2CH(CH3)–;

[0010] R 3 Is saturated or partially unsaturated C 10 -C 22 -alkyl;

[0011] R 4 It is C1-C 20 -alkyl; and

[0012] x+y+z=1 to 40;

[0013] wherein at least 80% by weight of the composition comprises water, a dispersant and a compound of Formula I; and wherein the composition has a pH in the range of 8 to 11.

[0014] The compositions of the present invention are useful as biocide-free additives to coating or pre-coating formulations. DETAILED DESCRIPTION

[0015] The present invention is a composition comprising, based on the weight of the composition, a) 50 to 90 wt % of water, b) 9 to 45 wt % of a carboxylic acid functionalized dispersant; c) and 0.5 to 10 wt % of a compound of formula I:

[0016]

[0017] wherein each R is independently H, methyl or ethyl;

[0018] R 1 =–R 2 -NR 3 -(CH2CH2O) z -H; or –C6-C 18 -alkyl; or –C(CH3)2R 4 ;

[0019] x is 1 to 40; y is 0 to 39; and z is 0 to 39;

[0020] The premise is that when y is 0, R 1 Yes –C(CH3)2R 4 ; and when y is 1 to 39, R 1 Yes – R 2 -NR 3 -(CH2CH2O) y -H or –C6-C 18 -alkyl;

[0021] R 2is –CH2CH2CH2– or –CH(CH3)CH2– or –CH2CH(CH3)–;

[0022] R 3 Is saturated or partially unsaturated C 10 -C 22 -alkyl;

[0023] R 4 It is C1-C 20 -alkyl; and

[0024] x+y+z=1 to 40;

[0025] wherein at least 80% by weight of the composition comprises water, a dispersant and a compound of Formula I; and wherein the composition has a pH in the range of 8 to 11.

[0026] The term carboxylic acid functionalized dispersant refers to a dispersant that is functionalized with COO - X + The present invention relates to a polymer functionalized with a group, wherein X is a counterion, such as sodium, potassium or ammonium. Examples of suitable dispersants include acrylic acid (AA) homopolymers, methacrylic acid (MAA) homopolymers, copolymers of AA and MAA, copolymers of AA or MAA with acrylate or methacrylate monomers such as hydroxypropyl acrylate (HPA) or hydroxyethyl methacrylate (HEMA), copolymers of maleic anhydride (MA) and diisobutylene (DIB). Dispersants prepared from maleic anhydride become carboxylic acid functionalized because the maleic anhydride groups are hydrolyzed to carboxylate groups in the presence of a base.

[0027] The concentration of the carboxylic acid functionalized dispersant ranges from 9 wt % or 15 wt % or 18 wt % to 45 wt % or to 42 wt % based on the weight of the composition. The concentration of water ranges from 50 wt % or 55 wt % to 90 wt % or to 85 wt %.

[0028] Based on the weight of the composition, the concentration of the compound of formula I is in the range of 0.5 wt % or 1 wt % or 1.5 wt % or 2 wt % to 10 wt % or to 8 wt % or to 6 wt %. When y is 0, the compound of formula I is represented by formula Ia:

[0029]

[0030] Where R 4 Preferably C6-C 14 -alkyl, and x = 2 to 30 or 10 or to 5. Examples of commercial surfactants within the scope of Formula Ia include TRITON TM RW-20(RW-20, x=2, R 4 = Decyl) surfactant, TRITONTM RW-50(RW-50, x=5, R 4 = Decyl) surfactant and TRITON TM RW-150(RW-150, x=15, R 4 = decyl) surfactant. (TRITON is a trademark of The Dow Chemical Company or its affiliates).

[0031] Yet another subclass of compounds of Formula I is represented by Formula Ib:

[0032]

[0033] Where R 3 Preferably, it is saturated or partially saturated C 14 -C 20 -alkyl, or a saturated or partially saturated C 16 -C 18 -alkyl, and x+y+z=2 to 32. As used herein, "partially unsaturated" means that there are one or two double bonds in the alkyl chain. Examples of commercial surfactants within the scope of Formula Ib include Ethox DT-15 (DT-15, x+y+z=15); and Ethox DT-30 (DT-30, x+y+z=30) tallow diamine.

[0034] Yet another subclass of surfactants of Formula I is illustrated by Formula Ic:

[0035]

[0036] Where R 1 Preferably C 12 -C 18 -alkyl, and x+y=12 to 18. An example of a commercial surfactant within the scope of Formula Ic is Ethox CAM-15 coconut amine (CAM-15, x+y=15).

[0037] The weight-to-weight ratio of dispersant to compound of formula I is typically in the range of 5: 1 to 10: 1. The pH of the composition is in the range of 8 or 8.5 to 11 or to 10 or to 9.5. The desired pH is conveniently achieved by adding a neutralizing agent, preferably an amine, such as 2-amino-2-methyl-1-propanol.

[0038] The composition may also contain auxiliary surfactants such as nonionic ethoxylated and / or propoxylated C6-C 12 Alcohol or C8-C 12Alcohol. The concentration of the co-surfactant (if used) is generally in the range of 1 wt % to 20 wt % based on the weight of the composition. Commercially available co-surfactants are TRITON TM DF-16 nonionic surfactant (DF-16).

[0039] The composition of the present invention can be mixed with a pre-coating additive such as TiO2 to impart corrosion protection properties to the pre-coating.

[0040] Example

[0041] Preparation of composition

[0042] The dispersant solution was placed in a 50-mL conical tube and vortexed with surfactant and sufficient AMP-952-amino-2-methyl-1-propanol neutralizer to achieve a final pH of about 9.5. Table 1 illustrates the relative proportions of dispersants; Surfactant I (RW-20, which is a compound within the scope of Formula I); Surfactant II (DF-16 used only in Example 4). 1124 refers to TAMOL TM 1124 dispersant (copolymer of AA and HPA); 165A refers to TAMOL TM 165A dispersant (copolymer of MA and DIB); and 851 refers to TAMOL TM 851 dispersant (AA homopolymer). Table 1 shows the composition of the dispersant compositions. The weight % of water in each sample is the difference between 100 and the sum of the dispersant and surfactant.

[0043] Table 1 - Dispersant Composition

[0044]

[0045] Preparation of samples for antimicrobial properties of TiO2

[0046] Four samples were prepared by adding each of the dispersant compositions of Examples 1-4 with Kronos 2311 TiO2 slurry to a high speed mixer (Flaktek) and mixing for 2 minutes at 1500 rpm. Comparative dispersant blends were prepared by combining the sample without RW-20 with the TiO2 slurry. Table 2 illustrates the composition of the modified TiO2 slurry composition. Kronos 2311 TiO2 slurry was used as the shading pigment for each study. The composition refers to the dispersant composition of Examples 1-4.

[0047] Table 2 - TiO2 slurry composition

[0048] sample Ex. No. <![CDATA[TiO2(g)]]> Composition (g) Water(g) 1 Ex.1 76.5 0.50 23.0 2 Ex.2 76.5 1.00 22.5 3 Ex.3 76.5 0.80 22.7 4 Ex.4 76.5 0.57 22.9

[0049] The concentration of the dispersant in each sample was 0.2 wt % based on the weight of the sample.

[0050] Use 10 6 -10 7 The dispersant composition and the slurry composition were inoculated with a pool of standard bacteria, yeast and mold (obtained from the American Type Culture Collection (ATCC), which is a common contaminant in coatings) with colony forming units / ml of sample (CFU / mL) for 3 times at 7-day intervals. After inoculation, the samples were stored in a 25°C incubator. The microbial contamination of the test samples was monitored by agar plate inoculation using the standard streak plate method. The samples were inoculated onto tryptic soy agar (TSA) and potato dextrose agar (PDA) plates on the 1st and 7th days after each microbial attack. All agar plates were checked daily until the 7th day after inoculation to determine the number of microorganisms that survived in the test samples. When not checked, the agar plates were stored in an incubator at 30°C for TSA plates and 25°C for PDA plates. The degree of microbial contamination was determined by counting colonies, where the rating score was determined based on the number of microbial colonies observed on the agar plates. The reported results are from the 7th day readings. Results are described by the score for each type of microorganism: B = bacteria, Y = yeast, and M = mold. For example, 3B describes a plate with a score of 3 for bacteria, or Tr Y(1) describes a plate with trace yeast (1 colony on the plate). Table 1 illustrates the rating system used to estimate the level of microbial contamination on the plan line plate. Colony refers to the number of colonies on the plate. Table 3 illustrates the rating system for evaluating microbial contamination.

[0051] Table 3 - Rating system for assessing microbial contamination

[0052] Colony Rating score pollute result none 0 none qualified 1 to 9 Tr Trace qualified 10 to 99 1 Very slight Failure 100 to about 1000 2 slight Failure Approximately 1000 to 10,000 3 Moderate Failure >10,000 4 Severe Failure

[0053] Table 4 illustrates the results of three attack tests (C1-C3) of the dispersant compositions.

[0054] Table 4 - Attack test results of dispersant compositions

[0055] Ex. No. C1(final) C2 (final) C3 (final) 1 qualified qualified qualified 2 qualified qualified qualified 3 qualified qualified qualified 4 qualified qualified qualified

[0056] In contrast, the copolymers of AA and HPA and the homopolymer of AA without the RW-20 amine ethoxylate surfactant failed all three challenge tests.

[0057] Table 5 illustrates three attack tests of TiO2 slurry compositions. Comparative Sample 1 (Comparative Example 1) was prepared without RW-20.

[0058] Table 5 - Attack test results of TiO2 slurry compositions

[0059] sample <![CDATA[TiO2]]> Dispersant Blends C1(final) C2 (final) C3 (final) Comparison 1 Kronos 2311 No RW-20 Failure Failure Failure 1 Kronos 2311 1 qualified qualified qualified 2 Kronos 2311 2 qualified qualified qualified 3 Kronos 2311 3 qualified qualified qualified 4 Kronos 2311 4 qualified qualified qualified

[0060] The results indicate that the efficacy of the dispersant composition extends beyond the corrosion protection of the composition itself. It is believed that the dispersant composition can be used to improve the corrosion protection of other additives used in coating formulations.

Claims

1. A composition comprising, based on the weight of the composition, a) 50 to 90 wt % water, b) 9 to 45 wt % carboxylic acid functionalized dispersant; c) and 0.5 to 10 wt % of a compound of formula I: wherein each R is independently H, methyl or ethyl; R 1 =–R 2 -NR 3 -(CH2CH2O) z -H; or –C6-C 18 -alkyl; or –C(CH3)2R 4 ; x is 1 to 40; y is 0 to 39; and z is 0 to 39; The premise is that when y is 0, R 1 Yes –C(CH3)2R 4 ; and when y is 1 to 39, R 1 Yes – R 2 -NR 3 -(CH2CH2O) y -H or -F-alkyl; R 2 is –CH2CH2CH2– or –CH(CH3)CH2– or –CH2CH(CH3)–; R 3 Is saturated or partially unsaturated C 10 -C 22 -alkyl; R 4 It is C1-C 20 -alkyl; and x+y+z=1 to 40; wherein at least 80% by weight of said composition comprises water, said dispersant and said compound of Formula I; and wherein said composition has a pH in the range of 8 to 11.

2. The composition of claim 1, wherein the composition has a pH in the range of 8.5 to 10, wherein the concentration of water is in the range of 55 wt % to 85 wt % based on the weight of the composition; the concentration of the carboxylic acid functionalized dispersant is in the range of 15 wt % to 45 wt %; and the concentration of the compound of formula I is in the range of 1.5 wt % to 8 wt %.

3. The composition of claim 2, wherein the compound of formula I is represented by: Compound of formula Ia Where R 4 It is C6-C 14 -alkyl, and x=2 to 30; or a compound of formula Ib: Where R 3 Is saturated or partially saturated C 14 -C 20 -alkyl, or a saturated or partially saturated C 16 -C 18 -alkyl, and x+y+z=2 to 32; or a compound of formula Ic: Where R 1 It is C 12 -C 18 -alkyl, and x+y=12 to 18.

4. The composition according to claim 3, wherein the compound of formula I is represented by a compound of formula Ia: Where R 4 is decyl, and x=2 to 10.

5. The composition of any one of claims 3 or 4, wherein the weight ratio of the carboxylic acid functionalized dispersant to the compound of Formula Ia is in the range of 5:1 to 10:1; wherein the composition further comprises 2-amino-2-methyl-1-propanol.

6. The composition of any one of claims 1 to 4, wherein the carboxylic acid functionalized dispersant is selected from homopolymers of acrylic acid, homopolymers of methacrylic acid, copolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid and hydroxypropyl acrylate, copolymers of acrylic acid and hydroxyethyl methacrylate, copolymers of methacrylic acid and hydroxypropyl acrylate, copolymers of methacrylic acid and hydroxyethyl methacrylate, and copolymers of maleic anhydride and diisobutylene; The composition further comprises 2-amino-2-methyl-1-propanol.

7. The composition of claim 6, wherein the carboxylic acid functionalized dispersant is selected from homopolymers of acrylic acid, copolymers of methacrylic acid and hydroxypropyl acrylate, and copolymers of maleic anhydride and diisobutylene.

8. The composition according to any one of claims 1 to 7, further comprising 1% to 20% by weight, based on the weight of the composition, of a nonionic ethoxylated C6-C 12 Alcohol, or nonionic propoxylated C6-C 12 Alcohol or nonionic ethoxylated-propoxylated C6-C 12 alcohol.

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