Polymer, process and composition

Abstract

There is described an aqueous urethane acrylate copolymer dispersion comprising a) from 10 to 95 wt-% of a polyurethane copolymer, and b) from 5 to 90 wt-% of a polyvinyl copolymer, where vinyl copolymer (b) comprises from 30 parts to 100 parts by weight of biorenewable monomer(s)such as itaconic acid, itaconate diesters and/or diamides for example dimethyl itaconate (DMI) or dibutyl itaconate (DBI) and where optionally the composition has a residual monomer level of less than 5000 ppm.

Claims

1. An aqueous copolymer composition comprising: a) 10 to 95 wt % of a polyurethane copolymer, and b) 5 to 90 wt % of a polyvinyl copolymer which is a polymerization reaction product of a monomer composition comprising from 30 parts to 100 parts by weight of at least one C.sub.4-6 unsaturated diacid and/or derivative thereof per 100 parts by weight of the monomer composition, wherein the at least one C.sub.4-6 unsaturated diacid and/or derivative thereof comprises an amount of carbon 14 sufficient to produce a decay of at least about 1.5 disintegrations per minute per gram carbon (dpm/gC); and wherein the polyvinyl copolymer has a residual monomer level of less than 5000 ppm as determined by gas chromatography mass spectrometry (GCMS).

2. The composition according to claim 1, wherein the at least one C.sub.4-6 unsaturated diacid and/or derivative thereof comprises at least one mono-ethylenically unsaturated dicarboxylic acid having from 4 to 6 carbon atoms in the acidic moiety and/or a derivative thereof.

3. The composition according to claim 2, wherein the at least one mono-ethylenically unsaturated C.sub.4-6 dicarboxylic acid and/or derivative thereof comprises at least one pentendioic acid and/or derivative thereof.

4. The composition according to claim 3, wherein the at least one pentendioic acid and/or derivative thereof comprises at least one itaconate functional monomer.

5. The composition according to claim 4, wherein the at least one itaconate functional monomer comprises at least one di(C.sub.4-10alkyl) itaconate.

6. The composition according to claim 5, wherein the at least one di(C.sub.4-10 alkyl) itaconate comprises at least one dibutyl itaconate (DBI).

7. The composition according to claim 4, wherein the at least one itaconate functional monomer comprises at least one di(C.sub.1-3alkyl) itaconate.

8. The composition according to claim 7, wherein the at least one di(C.sub.1-3 alkyl) itaconate comprises at least one dimethyl itaconate (DMI).

9. A process for preparing an aqueous polymer composition as claimed in claim 1, the process comprising the steps of: (i) preparing an aqueous dispersion of a polyurethane copolymer; (ii) preparing an aqueous polyvinyl copolymer dispersion, optionally in the presence of the polyurethane obtained from step (i), from a monomer composition, comprising 30 to 100 parts by weight of at least one C.sub.4-6 unsaturated diacid and/or derivative thereof per 100 parts by weight of the monomer composition, wherein at least one C.sub.4-6 unsaturated diacid and/or derivative thereof comprises an amount of carbon 14 sufficient to produce a decay of at least about 1.5 dpm/gC; (iii) optionally mixing the polyurethane (a) obtained from step (i) with the polyvinyl copolymer (b) obtained from step (ii) to form an aqueous urethane acrylate dispersion.

10. A polymer composition obtained by the process according to claim 9.

11. A coating composition comprising the polymer composition according to claim 1.

12. A substrate and/or article having a coating thereon which comprises the coating composition according to claim 11.

13. A method for preparing a coated substrate and/or article comprising the steps of applying a coating which comprises the coating composition according to claim 11 onto the substrate and/or article and optionally curing the coating composition in situ to form a cured coating thereon.

Description

EXAMPLES

Components

(1) Desmodur W dicyclohexylmethane diisocyanate (ex. Bayer) Voranol 2000 Polypropylene glycol diol with molecular weight 2000 (ex. DOW) DMI DiMethyl Itaconate DEI DiEthyl Itaconate DBI DiButyl Itaconate S Styrene MMA Methyl Methacrylate BA Butyl Acrylate DAAM DiAcetone AcrylAmide ADH Adipic DiHydrazide Plex PLEX 6852 (Ex. Evonik) DVB DiVinyl Benzene tBHPO tert-hydroperoxide (used as 70 wt-% solution) FeEDTA Iron Ethylenediaminetetraacetic acid (used as 1 wt-% solution) iAA Iso-ascorbic acid (used as 1 wt-% solution)
Urethane Prepolymer Emulsion I

(2) The urethane prepolymer was prepared in a three neck round bottom flask, equipped with a thermometer, mechanical stirrer and heating mantle. It was made under a nitrogen atmosphere. 0.16 parts of stannous octoate were added to 922.09 parts of Desmodur W, 216.00 parts of DMPA, 301.91 parts of Voranol P2000, and 360.00 parts of NMP. Another 0.15 parts of stannous octoate were added after one hour reaction at a temperature of 90 C. The residual NCO content was 7.72% (theoretical 8.21%). The prepolymer was neutralised with 162.97 parts of triethyl amine at 75 C. The mixture was mixed for half an hour. The neutralised prepolymer was dispersed in 5404.53 parts of demineralised water during 60 minutes. After dispersion, 75.87 parts of hydrazine monohydrate were added to extend the prepolymer. The final polyurethane dispersion had a pH of 7.5, and a solids content of 20%.

(3) Urethane Prepolymer Emulsion II

(4) The urethane prepolymer was prepared in a three neck round bottom flask, equipped with a thermometer, mechanical stirrer and heating mantle. It was made under a nitrogen atmosphere. 0.16 parts of stannous octoate were added to 922.09 parts of Desmodur W, 216.00 parts of DMPA, 301.91 parts of Voranol P2000, and 360.00 parts of NMP. Another 0.15 parts of stannous octoate were added after one hour reaction at a temperature of 90 C. The residual NCO content was 7.72% (theoretical 8.21%). The prepolymer was neutralised with 162.97 parts of triethyl amine at 75 C. The mixture was mixed for half an hour. The neutralised prepolymer was dispersed in 4025.57 parts of demineralised water during 60 minutes. After dispersion, 75.87 parts of hydrazine monohydrate were added to extend the prepolymer. The final polyurethane dispersion had a pH of 7.8, and a solids content of 25%.

Example 1

Preparation of an Aqueous 80/20 Polyurethane/Vinyl Polymer Dispersion According to the Invention

(5) The following process was used to prepare an aqueous polyurethane/acrylic polymer dispersion with a polyurethane/vinyl polymer weight ratio of 20/80.

(6) 3513 parts of the polyurethane prepolymer emulsion I and 252 parts of demineralized water, were charged to a round bottom flask, equipped with a thermometer, mechanical stirrer, condenser and heating mantle. During the preparation of the polyurethane/vinyl polymer dispersion a nitrogen atmosphere was maintained. To all iso-ascorbic acid solutions sufficient ammonia was added to raise pH to a value of between 8 and 8.5. To the polyurethane dispersion were added 326 parts of a monomer feed comprising components in a ratio as depicted in Table 1. The reactor contents were stirred at 60 C. for one hour. Then 3 parts of a t-butyl hydroperoxide solution (70 wt-% in water) and 17 parts of demineralized water were added to this mixture, followed by 0.05 parts of an Fe EDTA solution (1 wt-% in water) and 24 parts of an iso-ascorbic acid solution (1 wt-% in water) which started the reaction. The batch was kept at peak temperature for 15 minutes. After the batch was cooled to 60 C., 435 parts of a second monomer feed comprising components in a ratio as shown in Table 1, and the contents were stirred for one hour. To this mixture 30 parts of an iso-ascorbic acid solution (1 wt-%) were added and the reaction started. The batch was kept at peak temperature for 15 minutes. After the batch was cooled to 60 C., 544 parts of a third monomer feed comprising components in a ratio as shown in Table 1 were added. The contents were mixed for one hour, 38 parts of an iso-ascorbic acid solution (1 wt-%) were added which started the radical polymerisation. After 5 minutes another 38 parts of an iso-ascorbic acid solution (1 wt-%) were added and the batch was kept at peak temperature for 15 minutes. Then the final 38 parts of an iso-ascorbic acid solution were added. The mixture was stirred for half an hour and cooled to room temperature. To emulsions containing DAAM 70 mole-% based on DAAM concentration of ADH was added. The solids content was adjusted to 35% using demineralized water. The resulting polyurethane/acrylic polymer dispersion had a solids content of 35% and a pH of about 8.

(7) TABLE-US-00001 TABLE 1 Ex DMI DEI DBI S MMA BA DAAM* DVB pH 1.1 40 60 7.8 1.2 45 55 7.9 1.3 35 65 7.8 1.4 35 65 7.8 1.5 42 50 8 7.7 1.6 49 50 1 7.8 *Per part of DAAM 0.36 parts of ADH are added to the aqueous emulsion at the end of the production process

Example 2

Preparation of an Aqueous 50/50 Polyurethane/Vinyl Polymer Dispersion According to the Invention

(8) The following process was used to prepare an aqueous polyurethane/acrylic polymer dispersion with a polyurethane/vinyl polymer weight ratio of 50/50.

(9) 3871 parts of the polyurethane prepolymer emulsion II and 101 parts of demineralized water, were charged to a round bottom flask, equipped with a thermometer, mechanical stirrer, condenser and heating mantle. To all iso-ascorbic acid solutions sufficient ammonia was added to raise pH to a value of between 8 and 8.5. During the preparation of the polyurethane/vinyl polymer dispersion a nitrogen atmosphere was maintained. To the polyurethane dispersion were added 484 parts of a monomer feed comprising components in a ratio as depicted in Table 2. The reactor contents were stirred at 60 C. for one hour. Then 9 parts of a t-butyl hydroperoxide solution (70 wt-% in water) and 51 parts of demineralized water were added to this mixture, followed by 0.05 parts of a Fe EDTA solution (1 wt-% in water) and 68 parts of an iso-ascorbic acid solution (1 wt-% in water) which started the reaction. The batch was kept at peak temperature for 15 minutes. Next, a second feed of 484 parts of monomers comprising components in a ratio as shown in Table 2 were added and the batch was stirred at 60 C. for one hour. Next, 68 parts of an iso-ascorbic acid solution (1 wt-%) were added. The batch was kept at peak temperature for 15 minutes, after which 45 parts of an iso-ascorbic acid solution (1 wt-% in water) were added and the mixture was stirred for half an hour and cooled to room temperature. The solids content of the emulsion was adjusted to 35% using demineralized water. The resulting polyurethane/vinyl polymer dispersion had a solids content of 35% and a pH of about 8.

(10) TABLE-US-00002 TABLE 2 DMI DBI S BA Plex pH 2.1 35 65 7.7 2.2 50 50 7.6 2.3 10 30 60 7.6 2.4 45 55 7.7 2.5 35 60 5 7.7

Example 3

Preparation of an Aqueous 50/50 Polyurethane/Vinyl Polymer Dispersion According to the Invention

(11) The following process was used to prepare an aqueous polyurethane/acrylic polymer dispersion with a polyurethane/vinyl polymer weight ratio of 50/50.

(12) 3830 parts of the polyurethane prepolymer emulsion II were charged to a round bottom flask, equipped with a thermometer, mechanical stirrer, condenser and heating mantle. To all iso-ascorbic acid solutions sufficient ammonia was added to raise pH to a value of between 8 and 8.5. During the preparation of the polyurethane/vinyl polymer dispersion a nitrogen atmosphere was maintained. To the polyurethane dispersion were 479 parts of a monomer feed comprising components in a ratio as depicted in Table 3. The reactor contents were stirred at 60 C. for one hour. Then 9 parts of a t-butyl hydroperoxide solution (70 wt-% in water) and 51 parts of demineralized water were added to this mixture, followed by 0.1 parts of an Fe EDTA solution (1 wt-% in water) and 67 parts of an iso-ascorbic acid solution (1 wt-% in water) which started the reaction. The batch was kept at peak temperature for 15 minutes. After the batch was cooled to 60 C., 479 parts of a second monomer feed comprising components in a ratio as shown in Table 3, and the contents were stirred for one hour. To this mixture 89 parts of an iso-ascorbic acid solution (1 wt-% in water) were added and the reaction started. The batch was kept at peak temperature for 15 minutes. Then a final 111 parts of an iso-ascorbic acid solution (1 wt-% in water) were added. The mixture was stirred for half an hour and cooled to room temperature. To emulsions containing DAAM 70 mole-% based on DAAM concentration of ADH was added. The solids content of the emulsion was adjusted to 35% using demineralized water. The resulting polyurethane/vinyl polymer dispersion had a solids content of 35% and a pH of about 8.

(13) TABLE-US-00003 TABLE 3 DMI DBI S DVB BA DAAM* Plex pH 3.1 45 55 7.8 3.2 32 60 8 7.7 3.3 35 57 8 7.7 3.4 35 60 5 7.7 3.5 39 1 60 7.8 *Per part of DAAM 0.36 parts of ADH are added to the aqueous emulsion at the end of the production process
Film Properties

(14) To assess the merits of the invention, film properties were assessed for emulsions from each of the Tables. For this purpose, emulsions were formulated with 10 wt-% of ethyl diglycol, after which the formulated binders were stored at room temperature for Results are listed below in Table 4:

(15) TABLE-US-00004 TABLE 4 Knig Chemical resistance* hardness Water EtOH Andy Coffee Ex MFT ( C.) (s) (16 hrs) (1 hr) (16 hrs) (16 hrs) 1.1 >90 200 5 1 5 5 1.6 >90 200 5 1 5 5 2.2 9 150 5 3 3 5 2.5 <5 118 5 5 2 5 3.2 60 205 5 5 4-5 5 3.4 38 184 5 5 4-5 4