Vesiculated polymer particles

٨/

27480ΖΑ

PTZA2003/000140

WO 2004/029116

POLYMER PARTICLES IN THE FORM OF VESICLES

Technical field of invention

This invention relates to vesicular polymer particles and a manner of their production, with particular relevance to their use in paint coating compositions.

The History of Art

The morphology of multi-vesicular cross-linked polyester particles which has been described in the prior art consists mostly of hollow spherical particles with many void spaces in the dry state. These particles reabsorb water in paints and coatings, are difficult to manufacture and control of particle size is limited to process variables such as temperature, agitation speed and reaction time.

Previous art patent wo 81/01711 for the production of vesicular granules. In this process, a first emulsion (EMI) is formed, whereby an aqueous phase having a pigment dispersion therein is emulsified in a mixture of an unsaturated polyester and a co-polymerizable monomer such as a solution of polyester in the monomer. This is an EMI emulsion is then emulsified at high shear in an aqueous phase to form an emulsion 4-0405-1118-4205 water where the oil phase consists of polyester/monomer globules each comprising a number of vesicles of the initial aqueous phase. A polymerization initiator is added to initiate the polyester interlinking under curing conditions to form the desired vesicular granules. Shorter chain monomers (812 and below) which have minimal hydrophobicity are used.

UH لا ٠⁸⁰ا2

27480٨ ٨/ wo 2004/029116 PCT/ZA2OO3/OOO14O

It is an object of this invention to provide cross-linked polyester particles having a largely spherical morphology with multiple void spaces which prevents reentry and reabsorption of water when the cross-linked particles are dry.

It is a further object of this invention to provide a raw material composition conversion reaction which allows control of cross-linked particle size and distribution by process variables such as temperature, the degree of agitation and the reaction time as well as by the concentration of the modifying co-monomer in the raw material composition and by the optimization of the process stage by adding this co-monomer to said composition.

It is yet another object of this invention to provide a vesicular polymer particle which can be used in paint and coating formulations for the beneficial replacement of titanium dioxide pigments, expensive extenders, polymer emulsions, open time modifiers such as glycols and humectants with simultaneous achievement of improvement in opacity, whiteness, scratch resistance, in water resistance and special faux finish effects.

Exhibition of the invention

According to the invention, polymer vesicular particles comprise solid particles and are associated with said surfaces, aliphatic and/or sterically hindered long chain chemical groups, branched chain chemical groups.

In one form of the invention, the chemical groups are hydrophobic and include organic compounds with at least one polymerizable carbon - carbon 4 double bond with linear, branched or cyclic moieties having at least fourteen but not more than twenty-five carbon atoms, including but not limited to:

27480٨ ٨/ wo 2004/029116 ΡΤ/ΖΑ2003/000140 of 10110: lauryl methacrylate; castor oil acrylate; oleic castor acid acrylate: oleic castor acid methacrylate: soybean oil: unsaturated fatty acids, e.g. oleic acid, tallow fatty acid; unsaturated fatty alcohols, e.g. alcohol 0161, pentadeca-12-ene-1-ol. ; oleamide; triglycerides, e.g. talc oil, tung oil: unsaturated ethylenic urethanes; unsaturated acrylic urethanes: air-drying volatile oil alkyds: alkyl and aryl esters of maleic anhydride, alone or in combination.

These monomers are substantially more hydrophobic than the monomers used in the previous art, e.g. methyl methacrylate, ethyl acrylate, acrylonitrile and vinyl toluene.

In this description, the associated term may refer to groups included in the polymer particles or applied to the surface or portions of that surface.

According to a second aspect of the invention, a raw material composition for the production of vesicular particles comprises a functional carboxylic acid, a polymerizable free radical polyester resin, a co-reactive diluent monomer and a modifying co-monomer, the co-monomer comprising at least one polymerizable carbon-carbon double bond with linear, branched or cyclic moieties having at least fourteen but not less than twenty-five carbon atoms, including but not limited to:

lauryl methacrylate: castor oil acrylate: oleic castor acid acrylate; oleic castor acid methacrylate: soybean oil; unsaturated fatty acids, e.g. oleic acid, tallow fatty acid; unsaturated fatty alcohols, [.. oleyl alcohol, 14-12-08-1-0!. ; oleamide : triglycerides, e.g. talc oil, tung oil : unsaturated ethylenic urethanes : unsaturated acrylic urethanes : alkyds ة air-drying volatile oil : alkyl and aryl esters of maleic anhydride, alone or in combination.

27480٨ ٨/

WO 2004/029116 ΡΟΤ/ΖΑ2003/000140

The modifying co-monomer could comprise between 3 and 20% by mass of the added monomer or reactive diluent, and preferably comprise between 5 and 9% by mass of the added monomer diluent. This excludes the monomer diluent present in the polyester resin.

Suitable diluent co-monomers include ethylenic, acrylic and methacrylic functional monomers, for example styrene, butyl acrylate, methyl methacrylate and preferably styrene.

In one form, the composition of the polyester resin includes:

Propylene glycol 30.35% Phthalic anhydride 12996% Maleic anhydride 25.75% Styrene 30.75% Inhibitor (10% solution) 0.18%

TOTAL 100.00

According to a third aspect of the invention, a method of producing vesicular particles comprises steps of pre-dispersing pigmented particles in a polyester: • dissolving the pre-dispersed polyester pigment in a suitable monomer in the presence of a water-soluble base;

forming a stable emulsion of solution droplets of the polyester pigment and the monomer (oil phase) pre-dispersed in water; adding a hydrophobic monomer and polymerizing the polyester and the monomer 0-10111158018 thereby producing granules of opaque, cross-linked vesicular particles as a dispersion in water, the particles comprising hydrophobic groups associated with their surfaces.

27480٨ ٨/ wo 2004/029116 ΡΤ/ΖΑ2003/000140

Delayed addition of the hydrophobic monomer (modifier) ​​to a point where a stable emulsion has been formed, results in maintenance of the particle size of the vesicular particles produced, as a result of mixing during emulsification.

In one form, the base could comprise a polyamide, for example diethylenetriamine.

Particles of various sizes may be made by using different diffusers by mixing with different intensity during emulsification of the polyester in water. In one form of the invention, equipment suitably designed for controlling pressure, temperature, and residence time, for example homogenizers may be used. Chemical control of particle size and particle size distribution is also achieved by the introduction of aliphatic COmonomers ة long chains or sterically hindered, or branched.

Since most of these monomers or macromonomers make the average particle size coarser when incorporated into vesicular polymer particles, it was found preferable to add them later during the emulsification of the organic phase during the water phase. This minimized the effect on particle size. Coarser versions of the particle size can still be used to import into special effects in paintings e.g. texture.

The modified vesicular polymer particles, when incorporated into paint systems, have the effect of improving water resistance, abrasion resistance, whiteness and opacity. The following examples are intended to illustrate the invention, but are not intended to be limitations on the scope of the invention.

27480٨ ٨/ wo 2004/029116 ΡΤ/ΖΑ2003/000140

Example 1

The following vesicular polymer particles were synthesized as according to the prior art.

<td></td><td>Parts by weight</td>

<td>Floor 1 Polyester</td><td> 14,99</td>

<td>Titanium Dioxide</td><td> 0,86</td>

<td>Styrene</td><td> 654</td>

<td>Diethylene Triamine</td><td> 0,21</td>

<td>Floor 2 Polyvinyl alcohol solution (10%)</td><td> 13,28</td>

<td>Hydroxyethylcellulose solution (2.5%)</td><td> 10,45</td>

<td>Water</td><td> 52,92</td>

<td>Diethylene Triamene</td><td> 0,06</td>

<td>Floor 3 Water</td><td> 0,21</td>

<td>Ferrous sulfate</td><td> 0,01</td>

<td>Cumene hydroperoxide</td><td> 0,12</td>

<td>Floor 4 Bactericide</td><td> 0,35</td>

<td></td><td> 100,00</td>

Procedure

1. Titanium Dioxide is dispersed into the polymer at high speed in a high shear mixture.

2. Styrene and Diethylene Triamine are added 1) at reduced speed.

3. Stage 2 is prepared in another vessel at slow speed.

4. Stage 1 (organic phase) is added to stage 2 at high speed over high shear mixing and 1 059012-•• the desired particle size of the organic phase is obtained.

5. Stage 3 is then added at low shear by first pre-mixing the Ferrous Sulfate and then water is added.

6. The mixer is stopped and the product is left to cure quietly overnight.

٨/

27480ΖΑ

WO 2004/029116

ΡΟΊ7ΖΑ2003/000140

7. The vesicular particles are then stirred until homogeneous and a suitable bactericide is added.

A white liquid dispersion of cross-linked polymer particles is obtained in 121 having in dry form a film-free particle formation with the presence of multiple empty air spaces.

The average particle size will vary depending on the intensity of agitation applied at the time of addition of stage 1 to stage 2.

Example 2

For example 1 but 0.1% of Styrene was replaced by Lauryl Methacrylate. The stirring conditions were the same as in example 1.

Example 3

As in example 1 but 3% of the Styrene was replaced by Lauryl Methacrylate. The stirring conditions were the same as in example 1.

Example 4

As in example 1 but 5% of Styrene was replaced by Lauryl Methacrylate.

The agitation conditions being the same as in example 1.

Example 5

As in example 1 but 7% of Styrene was replaced by Lauryl Methacrylate. The stirring conditions were the same as in example 1.

Example 6

As in example 1 but 9% of Styrene was replaced by Lauryl Methacrylate

The agitation conditions being the same as in example 1.

Example 7

As in example 1 but 20% of Styrene was replaced by Methacrylate

Lauryl. The stirring conditions being the same as in example 1

27480٨ ٨/

PCT/ZA2OO3/OOO14O

WO 2004/029116

Example 8

The vesicular particles produced in the above Examples 1 to 7 were examined for the following properties:

L Total solids content using a Mettler HR 73 Halogen Moisture Analyzer

2. Viscosity using a Brookfield LVT viscometer.

3. pH using a Metrohm 744 pH meter.

4. Specific gravity using a Sheen lOOcc “weight per gallon” cup.

5. Opacity using Leneta's opacity map form 2Α and Sheen's micropac reflectometer.

6. Whiteness using spectrophotometer, color view from BYK-Gardner.

7. Average particle size using a cathode ray microscope (Topcon &amp; Scion image analysis software).

Next results:

VESICULAR PARTICLES PRODUCED ON THE MIXER OF

VARIABLE SHEAR COWLES

<td>LMA %</td><td>Solids ٥/٥</td><td>Viscosity, cps</td><td>pH</td><td>SG</td><td>Opacity</td><td>Whiteness</td><td>Average particle size</td>

<td> 0</td><td> 23,50</td><td> 800</td><td> 6,78</td><td> 1,043</td><td> 0,93</td><td> 94,0</td><td> 5,6</td>

<td> 0,1</td><td> 23,80</td><td> 610</td><td> 6,66</td><td> 1,044</td><td> 0,96</td><td> 96,7</td><td> 6,1</td>

<td> 3</td><td> 23,90</td><td> 1200</td><td> 6,50</td><td> 1,044</td><td> 0,96</td><td> 96,1</td><td> 6,9</td>

<td> 5</td><td> 23,63</td><td> 1250)</td><td> 6,55</td><td> 1,046</td><td> 0,95</td><td> 96,4</td><td> 15</td>

<td> 7</td><td> 23,7</td><td> 3720</td><td> 6,74</td><td> 1,042</td><td> 0,96</td><td> 97,0</td><td> 8,3</td>

<td> 9</td><td> 23,46</td><td> 3900</td><td> 6,75</td><td> 1,044</td><td> 0,95</td><td> 95,4</td><td> 16,0</td>

<td> 20</td><td> 23,67</td><td> 14800</td><td> 6,73</td><td> 1,033</td><td> 0,88</td><td> 94,5</td><td> 36,5</td>

The improvement in opacity and whiteness is clearly illustrated as well as the effect of the increase in particle size.

27480٨ ٨/

PCT/ZA2OO3/OOO14O wo 2004/029116

Example 9

The vesicular polymer particles of Examples 1 to 7 were formulated into the following mixture to produce water-based emulsion paint:

<td>RAW MATERIAL</td><td>/PARTS BY WEIGHT</td>

<td>Vesicular Particles Coalescent Acrylic Styrene Polymer Emulsion Ammonia (diluted in water 1:1) Aqueous Dispersion of Titanium Dioxide Thickener</td><td> 115 9,1 1,1 9,7</td>

The paints obtained by the use of vesicular particles of Example 1-7 were tested for resistance to wet friction (abrasion) and the following results were recorded:

1. Painting using Vesicular Particles from Example 1 = 20 cycles

2. Painting using Vesicular Particles from Example 2 - 120 cycles

3. Painting using Vesicular Particles from Example 3 = 500 cycles

4. Painting using Vesicular Particles from Example 4 = 1100 cycles

5. Painting using Vesicular Particles from Example 5 = 1500 cycles

6. Painting using Vesicular Particles from Example 6 = 900 cycles

7. Painting using Vesicular Particles from Example 7 - 600 cycles

Higher wet abrasion cycles indicate improved abrasion and friction resistance in the final paint. The results confirm the improvement in abrasion resistance in water obtained by using compositions of this invention in paints and coatings.

Example 10

Repeat of !^,example 4 but using Octadecene instead of Methacrylate

Lauryl. Agitation conditions as in example 1.

27480٨ ٨/

PCT/ZA2OO3/OOO14O

WO 2004/029116

Example 11

Repeat Example 4 but using Methyl Acrylate Castor Oleate instead of Lauryl Methacrylate. Stirring conditions as in Example 1.

Example 12

Repeat example 4 but using Ricin Oleate Methacrylate instead of

Lauryl methacrylate. Stirring conditions as in Example 1.

Example 13

The vesicular polymer particles of Examples 10, 11 and 12 were measured for properties as illustrated in Example 8.

Here are the results:

VESICULAR PARTICLES PRODUCED ON COWLES VARIABLE SHEAR MIXER

<td>Example</td><td>Solids ٥/٥</td><td>Viscosity, cps.</td><td>pH</td><td>SG</td><td>opacity Whiteness Average particle size, microns</td>

<td> 10</td><td> 23,39</td><td> 10000</td><td> 6,56</td><td> 1,045</td><td> 0,95 95,0 17</td>

<td> 11</td><td></td><td> 1800</td><td> 6,72</td><td></td><td> 0,96 95,4 9</td>

<td> 12</td><td> 23,50</td><td> ,900</td><td> 6,47</td><td> 1,045</td><td> 0,96 95,2 9</td>

Example 14

The vesicular polymer particles of Example 10, 11 and 12 were formulated into water-based paint such as Example 9 and tested for wet friction (abrasion) resistance.

1. Painting using Vesicular Particles from Example 1 = 20 cycles

2. Painting using Vesicular Particles from Example 10 = 500 cycles

3. Painting using Vesicular Particles from Example 1 1 = 1000 cycles

4. Painting using Vesicular Particles from Example 12 = 1200 cycles

The results confirm the improvement in water and friction resistance obtained by using compositions of this invention in paints and coatings.

27480٨ ٨/ wo 2004/029116 PCT/ZA2OO3/ÛOO14O

Example 15

Water resistance and whiteness of the paint containing:

Vesicular particles synthesized using prior art technology (Example 1),

Vesicular particles synthesized using the present patented technology (Example 4).

were compared. The paint is of average quality and can be used indoors or outdoors.

The following results were obtained.

<td>Paint Vesicular particles of</td><td>HAS (Example 1)</td><td>B (Example 4)</td>

<td>Water resistance</td><td></td><td></td>

<td>* Water droplet method¹</td><td>5 min</td><td>10 min</td>

<td>* Wet abrasion resistance 2</td><td>1280 cycles</td><td>2198 cycles</td>

<td>Color D 10° (against Std) 3</td><td></td><td></td>

<td>L</td><td>-0.28 D</td><td>-0.51 D</td>

<td>HAS</td><td>-0.06 G</td><td>-0.10 G</td>

<td>B</td><td>1.09 Y</td><td>0.43 Y</td>

<td>FROM CMC</td><td> 1,41</td><td> 0,63</td>

(1) Water resistance, by this method, is carried out by subjecting a film of paint, which has been dried at room temperature, for 24 hours to water droplets on the surface of the paint. The time taken for the paint to either blister or soften on contact with the water droplets is recorded. The longer the time the better the water resistance. The test is stopped after 10 minutes.

(2) Wet abrasion resistance is carried out by the attached method. The higher the number of cycles, the better the wet abrasion resistance.

(3) The color is measured on a color computer and compared to the paint containing the vesicular particles from Example 1.

The L value, if positive, indicates a difference in lightness and if negative, the difference in darkness. Paint B is slightly darker than Paint A.

27480٨ ٨/ wo 2004/029116 ΡΤ/ΖΑ2003Ο0140

Value A, if positive, indicates a difference in redness and if negative, the difference in greenness. Paint B is a tiny bit greener than Paint A.

Value B, if positive, indicates the difference in yellow tint and if negative, the difference in blue tint. Paint B is less yellow than Paint A and therefore whiter.

The DE CMC is the overall difference in color. Paint B has less color change overall than Paint A.

The vesicular particles (1.. in Example 1 and Example 4) were formulated into the following water-based paints:

Medium quality interior/exterior paint.

Premium quality interior matte paint.

Paintings خ effects

The properties of the paints were evaluated.

Below the paint formulations are recorded along with the test results ٠

Example 17

The vesicular particles were synthesized as in Example 1 and Example 4.

Vesicular particles were applied to a white and black opacity diagram using a 200 mm plotting bar.

Opacity (i.e. obliterating power) was measured on the white and black parts of the opacity diagram by means of a The resulting reflectance measurements above white are divided by the reflectance measurements above black. Here are the results:

27480٨ ٨/ wo 2004/029116 PCT/ZA2OO3/OOO14O

<td>Example 1 Opacity 0.93</td><td>Example 4 0.95</td>

The higher the number, the greater the obliterating power of the vesicular granule.

<td>Interior/Exterior Matte Paint - Premium Quality Painting A Water 28.11 Dispersant 0.24 Titanium Dioxide 7.90 Calcium Carbonate (2 microns) 21.82 Calcium Carbonate (5 microns) 8.11 Propylene Glyco! 1.02 Anionic Sulphating Agent 0.09 Skimmer 0.31 Hydroxyethylcellulose 0.33 Ammonia 0.11 Styrene/Acrylic Emulsion (50% solids) 17.20 Coalescing 1.66 Bactericide 0.21 Vesicular Particles (Example 1) 12.91 Vesicular Particles (Example 2) TOTAL 100.0 RESULTS</td><td>Painting B 28.11 0.24 7.90 21.82 L02 0.09 03 0.11 17.20 1.66 0.21 ,12,91 100.0</td>

<td>Painting A</td><td>Painting B</td>

<td>Water resistance * Water droplet method 8 * Wet abrasion resistance &gt;10,000 Opacity 0.88 Whiteness 1 79.57</td><td> 10 &gt;10,000 0,92 81,06</td>

NOTE: Paint B is more water resistant, higher opacity and whiter than Paint A.

(1) Whiteness is measured on a color computer. The higher the number, the whiter the paint.

27480٨ ٨/

WO 2004/029116

ΡT/ΖΑ2003/000140

Premium Quality Matte Interior Paint

<td colspan="2"></td><td>Painting A</td><td>Painting B</td>

<td> 1.</td><td>Titanium Dioxide Dispersion</td><td> 21.32</td><td> 21.32</td>

<td> 2</td><td>Talc Dispersion</td><td> 19.07</td><td> 19.07</td>

<td> 3.</td><td>Thickness</td><td> 0.29</td><td> 0.29</td>

<td> 4.</td><td>Water</td><td> 2.02</td><td> 2.02</td>

<td> 5.</td><td>Ammonia</td><td> 0.24</td><td> 0.24</td>

<td> 6.</td><td>Propylene Glycol</td><td> 0.1</td><td> 0.77</td>

<td> 7</td><td>Coalescing</td><td> 1.345</td><td> 1.345</td>

<td> 8.</td><td>Skimmer</td><td> 0.25</td><td> 0.25</td>

<td> 9.</td><td>Dispersing</td><td> 0.19</td><td> 0.19</td>

<td> 10.</td><td>Bactericide</td><td> 0.10</td><td> 0.10</td>

<td> 11.</td><td>Pure acrylic emulsion (48% solids)</td><td> 39.55</td><td> 39.55</td>

<td> 12.</td><td>Thickener (for low shear)</td><td> 0.15</td><td> 0.15</td>

<td> 13.</td><td>Thickener (for high shear)</td><td> 0.29</td><td> 0.29</td>

<td> 14.</td><td>Water</td><td> 2.95</td><td> 2.95</td>

<td> 15.</td><td>Vesicular Particles'</td><td> 11.51</td><td>سس</td>

<td> 16</td><td>Vesicular Particles 2</td><td></td><td> 11.51</td>

<td colspan="2">TOTAL</td><td> 100.0</td><td> 100.0</td>

<td colspan="2">RESULTS</td><td></td><td></td>

<td></td><td></td><td>Painting A</td><td>Painting B</td>

<td colspan="2">Resistance at 181]</td><td></td><td></td>

<td></td><td>* Water droplet method</td><td> 8</td><td> 10</td>

<td></td><td>* Resistance to wet abrasion</td><td> &gt; 0,()00</td><td> &gt;10,000</td>

<td></td><td>Opacity</td><td> 92.8</td><td> 95.1</td>

<td></td><td>Whiteness</td><td> 78.23</td><td> 82.14</td>

NOTE: Paint B is more resistant at 110, higher opacity and whiter than Paint A.

(1) Vesicular particles were manufactured to the particle size as in Example 1 and to an average particle size of 25 microns by adjusting the agitation rate.

(2) The vesicular particles were manufactured to the particle size according to Example 4 and to an average particle size of 25 microns.

27480٨ ٨/

WO 2004/029116

ΡT/ΖΑ2003/000140

Paintings ة Effects

<td></td><td>Painting A</td><td>Painting B</td>

<td>Water</td><td> 6.07</td><td> 6.07</td>

<td>2. Propylene Glycol</td><td> 1.79</td><td> 1.79</td>

<td>3. Dispersant</td><td> 0.11</td><td> 0.11</td>

<td>4. Surfactant</td><td> 0.18</td><td> 0.18</td>

<td>5. Skimmer</td><td> 0.09</td><td> 0.09</td>

<td>6. Bactericide</td><td> 0.05</td><td> 0.05</td>

<td>7. Ammonia</td><td> 0.10</td><td> 0.10</td>

<td>8. Hydroxyethylcellulose</td><td> 0.05</td><td> 0.05</td>

<td>9. Pure acrylic emulsion (48%5011٥5ل)</td><td> 47.04</td><td> 47.04</td>

<td>10 Coalescent</td><td> 2.09</td><td> 2.09</td>

<td>11. Vesicular particles'</td><td> 39.16</td><td> -</td>

<td>12. Vesicular particles 2</td><td> ٠</td><td></td>

<td>The thickener</td><td> 1.23</td><td> 1.23</td>

<td>14. Water</td><td>ns?</td><td> 0.82</td>

<td>15. Tint(s) and color</td><td> 1.22</td><td> 1.22</td>

<td>TOTAL</td><td> 100.0</td><td> 100.0</td>

RESULTS

Painting A Painting B

Suede effects³ No Yes (1) The vesicular particles were manufactured to the particle size as per Example 1 and to an average particle size of 25 microns by adjusting the agitation rate.

(2) The vesicular particles were manufactured to the particle size according to Example 4 and to an average particle size of 25 microns.

(3) The Suede effect is an effect transmitted to the paint to give a colored texture effect.

Paint B has a superior Suede Effect to Paint B with the vesicular granules being more prominent on the surface due to lower water absorption.