Organic material

Abstract

The invention provides a plasticiser composition which comprises: (a) a first plasticiser which is one or more compounds of general formula (I) ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising from seven to twelve carbon atoms; and (b) a second plasticiser which is a citrate ester; a plasticised polymer formulation comprising a polymer and the plasticiser composition; a plastics article comprising the plasticised polymer formulation; and a method for the preparation of the plasticiser composition to provide a plasticised polymeric formulation which can be stored for up to five weeks with an increase of viscosity of less than 300%.

Claims

1. A plasticiser composition which consists of: (a) a first plasticiser which is one or more compounds of general formula (I) ##STR00004## wherein R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising from seven to twelve carbon atoms; and (b) a second plasticiser which is a citrate ester of general formula (II): ##STR00005## wherein R.sup.4 represents an R.sup.5C(O)-moiety, each R.sup.3 independently represents a straight or branched chain alkyl moiety having from four to eight carbon atoms, and R.sup.5 represents a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n-octyl, isooctyl, and/or 2-ethylhexyl alkyl moiety; and optionally (c) a third plasticiser which is dialkyl phthalate, alkyl aralkyl phthalate, dialkyl cyclohexan-1,2-dicarboxylate, dialkyl cyclohexane-1,3-dicarboxylate, dialkyl cyclohexane-1,4-dicarboxylate, dialkyl terephthalate which differs from the compound of general formula (I), trialkyl trimellitate, alkyl benzoate, dibenzoic esters of glycol, hydroxybenzoic ester, ester of saturated monocarboxylic acid, ester of unsaturated monocarboxylic acid, ester of saturated dicarboxylic acid, ester of unsaturated dicarboxylic acid, amide and/or ester of aromatic sulfonic acid, alkylsulfonic ester, glycerol ester, isosorbide ester, phosphoric ester, alkylpyrrolidone derivative, dialkyl 2,5-furan-dicarboxylate, dialkyl 2,5-tetrahydrofurandicarboxylate, and/or a polyester made of an aliphatic and/or aromatic polycarboxylic acid with at least a dihydric alcohol.

2. A plasticiser composition as defined in claim 1 wherein in general formula (I) R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising from seven to nine carbon atoms.

3. A plasticiser composition as defined in claim 1 wherein in general formula (I) R.sup.1 and R.sup.2 both represent 2-ethylhexyl, isononyl, or 2-propylheptyl.

4. A plasticiser composition as defined in claim 1 wherein in general formula (I) R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising eight carbon atoms.

5. A plasticiser composition as defined in claim 1 wherein in general formula (I) R.sup.1 and R.sup.2 each represent a 2-ethylhexyl alkyl moiety.

6. A plasticiser composition as defined in claim 1 wherein the citrate ester is an alkyl ester of citric acid, or an acetyl alkyl citrate ester.

7. A plasticiser composition as defined in claim 1 wherein R.sup.5 represents a straight or branched chain alkyl moiety having from four to eight carbon atoms.

8. A plasticiser composition as defined in claim 7 wherein R.sup.3 and R.sup.5 each independently represent a straight or branched chain alkyl moiety having from six to eight carbon atoms.

9. A plasticiser composition as defined in claim 1 wherein the citrate ester is acetyl tributyl citrate, and/or acetyl trioctyl citrate.

10. A plasticiser composition as defined in claim 1 which comprises more than 50% by weight of a first plasticiser.

11. A plasticiser composition as defined in claim 1 wherein the plasticiser composition comprises from 50% to 80% by weight of a first plasticiser and from 20% to 50% by weight of a second plasticiser.

12. A plasticiser composition as defined in claim 1 wherein the third plasticiser is a dialkyl adipate.

13. A plasticiser composition as defined in claim 1 which comprises from 50% to 70% by weight of a first plasticiser (a), from 20% to 50% by weight of a second plasticiser (b), and from 0 to 10% by weight of a third plasticiser (c).

14. A plasticised polymer formulation which comprises a polymer and a plasticiser composition which consists of: (a) a first plasticiser which is one or more compounds of general formula (I) ##STR00006## wherein R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising from seven to twelve carbon atoms; and (b) a second plasticiser which is a citrate ester of general formula (II): ##STR00007## wherein R.sup.4 represents an R.sup.5C(O)-moiety, each R.sup.3 independently represents a straight or branched chain alkyl moiety having from four to eight carbon atoms, and R.sup.5 represents a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n-octyl, isooctyl, and/or 2-ethylhexyl alkyl moiety; and optionally (c) a third plasticiser which is dialkyl phthalate, alkyl aralkyl phthalate, dialkyl cyclohexan-1,2-dicarboxylate, dialkyl cyclohexane-1,3-dicarboxylate, dialkyl cyclohexane-1,4-dicarboxylate, dialkyl terephthalate which differs from the compound of general formula (I), trialkyl trimellitate, alkyl benzoate, dibenzoic esters of glycol, hydroxybenzoic ester, ester of saturated monocarboxylic acid, ester of unsaturated monocarboxylic acid, ester of saturated dicarboxylic acid, ester of unsaturated dicarboxylic acid, amide and/or ester of aromatic sulfonic acid, alkylsulfonic ester, glycerol ester, isosorbide ester, phosphoric ester, alkylpyrrolidone derivative, dialkyl 2,5-furan-dicarboxylate, dialkyl 2,5-tetrahydrofurandicarboxylate, and/or a polyester made of an aliphatic and/or aromatic polycarboxylic acid with at least a dihydric alcohol.

15. A plasticised polymer formulation as defined in claim 14 wherein the polymer is a thermoplastic polymer.

16. A plasticised polymer formulation as defined in claim 14 wherein the polymer is a polyvinylchloride (PVC), polyvinyl butyral (PVB), a homo- or co-polymer of styrene, polyacrylate, polysulfide, and/or a thermoplastic polyurethane (PU).

17. A plasticised polymer formulation as defined in claim 14 wherein the polymer is PVC.

18. A plasticised polymer formulation as defined in claim 14 which is in the form of a plastisol.

19. A plastics article which is formed from a plasticised polymer formulation as defined in claim 14.

20. A plastics article as defined in claim 19 which is a floor covering, a wall covering, wall paper, a decorative film, a pipe or tubing, a sheet, roofing, a bag, an article of clothing, guttering, and/or a coating.

21. A method of preparing a polymer composition which method comprises a step of mixing a polymer with a plasticiser composition wherein the plasticiser composition consists of: (a) a first plasticiser which is one or more compounds of general formula (I) ##STR00008## wherein R.sup.1 and R.sup.2 each independently represent a straight or branched chain alkyl moiety comprising from seven to twelve carbon atoms; and (b) a second plasticiser which is a citrate ester of general formula (II): ##STR00009## wherein R.sup.4 represents an R.sup.5C(O)-moiety, each R.sup.3 independently represents a straight or branched chain alkyl moiety having from four to eight carbon atoms, and R.sup.5 represents a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n-octyl, isooctyl, and/or 2-ethylhexyl alkyl moiety; and optionally (c) a third plasticiser which is dialkyl phthalate, alkyl aralkyl phthalate, dialkyl cyclohexan-1,2-dicarboxylate, dialkyl cyclohexane-1,3-dicarboxylate, dialkyl cyclohexane-1,4-dicarboxylate, dialkyl terephthalate which differs from the compound of general formula (I), trialkyl trimellitate, alkyl benzoate, dibenzoic esters of glycol, hydroxybenzoic ester, ester of saturated monocarboxylic acid, ester of unsaturated monocarboxylic acid, ester of saturated dicarboxylic acid, ester of unsaturated dicarboxylic acid, amide and/or ester of aromatic sulfonic acid, alkylsulfonic ester, glycerol ester, isosorbide ester, phosphoric ester, alkylpyrrolidone derivative, dialkyl 2,5-furan-dicarboxylate, dialkyl 2,5-tetrahydrofurandicarboxylate, and/or a polyester made of an aliphatic and/or aromatic polycarboxylic acid with at least a dihydric alcohol; wherein the plasticised polymeric formulation can be stored for up to five weeks with an increase of viscosity of less than 300%.

Description

PREPARATION EXAMPLE 1

(1) The plasticiser formulations tested in Examples 2 and 3, and Comparative Examples 4, 5, and 6 were prepared as follows.

(2) The ingredients listed in Table 1 below were weighed in the proportions indicated to a 1 litre steel vessel and mixed by hand using a palette knife until the solid components were fully wetted by the liquids. They were then mixed for a further 6 minutes at 1800 rpm in a PC Labor system LDV1A dispersion mixer. The additional additives included a stabiliser.

(3) TABLE-US-00001 TABLE 1 Amount (parts per hundred parts Ingredient resin) PVC 100 First plasticiser 30 Second plasticiser 10 Mineral Filler 31.5 Additives 2

EXAMPLE 2

(4) A plasticiser formulation comprising PVC, a first plasticiser which is DOTP (marketed as Eastman 168 (registered trademark)), and a second plasticiser which is a mixture of acetyl tributyl citrate ester and acetyl trioctyl citrate ester (marketed as Citrofol D90 (registered Trademark) was prepared and was stored for five weeks at different temperatures, as indicated in Table 2. The viscosity of the formulation was measured using a Brookfield RVT Viscometer (spindle RV5, 5 rpm) and recording in mPa.Math.s at the intervals indicated in Table 2. The viscosity increase in Table 2 is calculated from the viscosity at the recorded time divided by that recorded on the first day.

(5) TABLE-US-00002 TABLE 2 Viscosity increase at specified storage temperature/mPa .Math. s Ambient No. of days temperature 30° C. 10° C. 0 100% 100% 100% 1 169% 117% 194% 2 165% 115% 197% 3 153% 121% 199% 7 180% 150% 289% 14 169% 173% 211% 35 170% 216% 198%

(6) The data surprisingly shows that the formulation according to the invention has a relatively low viscosity increase at low, ambient and high temperatures over a five week period as the viscosity stays within 300% of the original viscosity.

EXAMPLE 3

(7) A plasticiser formulation comprising PVC, a first plasticiser which is DOTP (Eastman 168), and a second plasticiser which is acetyl tributyl citrate ester (which is marketed as Citrofol B2 (registered trademark)) was prepared and was stored for five weeks at different temperatures, as indicated in Table 3. The viscosity of the formulation was measured at the intervals indicated in Table 3.

(8) TABLE-US-00003 TABLE 3 Viscosity increase at specified storage temperature Ambient No. of days temperature 30° C. 10° C. 0 100% 100% 100% 1 150% 111% 242% 2 160% 106% 242% 3 142% 133% 258% 7 176% 163% 259% 14  161% 196% 269% 35  171% 205% 250%

(9) The data shows that the formulation has a relatively low viscosity increase at low, ambient and high temperatures as the viscosity stays within 300% of the original viscosity.

TEST EXAMPLE 4

(10) The gelation speed of the plasticiser formulations according to the invention which are exemplified in Examples 2 and 3 was measured as follows.

(11) The PVC plastisol for each Example was placed in a rheometer (Anton Paar MCR 302, PP25 plate, gap setting 1 mm). The plastisol was heated at a rate of 2° C./min, and its viscosity was measured as the temperature of the plastisol was increased. The gelation speed is determined by the inflection point temperature in the resulting temperature/viscosity curve (calculated using Anton Paar Rheocompass software). Results are given in Table 4 where a lower temperature indicates a faster gelation speed.

(12) TABLE-US-00004 TABLE 4 Example Inflection point (° C.) 2 81.3 3 85.5

(13) The data shows that the formulations according to the invention have an acceptable inflection point of lower than 90° C. such that they are suitable for use in an industrial production line. Experience with formulations commonly used in the production of floor covering shows that below this point a plastisol can be successfully processed without excessive processing temperatures or dwell times for reasons of energy efficiency and optimising production capacity. Formulations based on DINP with a fast-fusing secondary plasticiser have gelation temperatures measured by this method of around 80° C. and values close to this point are desirable.

COMPARATIVE EXAMPLE 5

(14) A first comparative plasticiser formulation comprising PVC, a first plasticiser which is DOTP (Eastman 168), and a second plasticiser which is a propylene glycol dibenzoate ester (marketed as K-Flex PG (registered trademark)) was prepared and was stored for five weeks at different temperatures, as indicated in Table 5. The viscosity of the formulation was measured at the intervals indicated in Table 5.

(15) TABLE-US-00005 TABLE 5 Viscosity increase at specified storage temperature No. Ambient of days temperature 30° C. 10° C. 0 100% 100% 100% 1 168% 178% 288% 2 178% 233% 282% 3 161% 264% 282% 7 181% 355% 270% 14  200% 355% 275% 35  204% 355% 276%

(16) The data shows that the first comparative formulation has a relatively low viscosity increase at low and ambient temperatures as the viscosity stays within 300% of the original viscosity. However, at a high temperature, the viscosity increase is at an unacceptable level over 300% of the original viscosity after seven days which would mean that the formulation would not be suitable for summer use. It is not practical to have different formulations for different times of year due to the unpredictability of the weather and because of the difficulty of matching the properties of different formulations.

COMPARATIVE EXAMPLE 6

(17) A plasticiser formulation comprising PVC, a first plasticiser which is DINCH, and a second plasticiser which is the blend of acetyl trioctyl citrate ester and acetyl tributyl citrate ester

(18) (Citrofol D90) was prepared and was stored for five weeks at different temperatures, as indicated in Table 6. The viscosity of the formulation was measured at the intervals indicated in Table 6.

(19) TABLE-US-00006 TABLE 6 Viscosity increase at specified storage temperature No. Ambient of days temperature 30° C. 10° C. 0 100% 100% 100% 1 134% 166% 182% 2 138% 177% 185% 3 148% 201% 191% 7 168% 280% 194% 14  199% 321% 193% 35  229% 426% 326%

(20) The data shows that the formulation has a relatively low viscosity increase at an ambient temperature but an unacceptably high increase in viscosity at low (10° C.) and high (30° C.) temperatures as the viscosity is over 300% of the original viscosity, even over 400% of the original viscosity.

COMPARATIVE EXAMPLE 7

(21) A plasticiser formulation comprising PVC, a first plasticiser which is DINCH, and a second plasticiser which is acetyl tributyl citrate ester (Citrofol B2) was prepared and was stored for five weeks at different temperatures, as indicated in Table 7. The viscosity of the formulation was measured at the intervals indicated in Table 7.

(22) TABLE-US-00007 TABLE 7 Viscosity increase at specified storage temperature No. Ambient of days temperature 30° C. 10° C. 0 100% 100% 100% 1 136% 281% 194% 2 143% 298% 206% 3 153% 368% 210% 7 161% 490% 208% 14  208% 617% 235% 35  261% 694% 348%

(23) The data shows that the formulation has a relatively low increase in viscosity at an ambient temperature but an unacceptably high increase in viscosity at low (10° C.) and high (30° C.) temperatures as the increase in viscosity is over 300% of the original viscosity, even over 600% of the original viscosity.

COMPARATIVE EXAMPLE 8

(24) A comparative plasticiser formulation comprising PVC, a first plasticiser which is DOTP (Eastman 168), and a second plasticiser which is tert-butylphenyl diphenyl phosphate (marketed as Santicizer S1535 (registered trademark)) was prepared and was stored for five weeks at different temperatures, as indicated in Table 8. The viscosity of the formulation was measured at the intervals indicated in Table 8.

(25) TABLE-US-00008 TABLE 8 Viscosity increase at specified storage temperature No. Ambient of days temperature 30° C. 10° C. 0 100% 100% 100% 1 186% 187% 239% 2 185% 266% 240% 3 190% 306% 240% 7 230% 373% 232% 14  248% 373% 239% 35  295% 373% 244%

(26) The data shows that the first comparative formulation has a relatively low viscosity increase at low and ambient temperatures as the viscosity stays within 300% of the original viscosity. However, at a high temperature, the viscosity increase is at an unacceptable level over 300% of the original viscosity after three days which would mean that the formulation would not be suitable for summer use. It is not practical to have different formulations for different times of year due to the unpredictability of the weather and because of the difficulty of matching the properties of different formulations.

COMPARATIVE EXAMPLE 9

(27) A first comparative plasticiser formulation comprising PVC, a first plasticiser which is DOTP (Eastman 168), and a second plasticiser which is isodecyl diphenyl phosphate (marketed as Santicizer S148 (registered trademark)) was prepared and was stored for five weeks at different temperatures, as indicated in Table 9. The viscosity of the formulation was measured at the intervals indicated in Table 9.

(28) TABLE-US-00009 TABLE 9 Viscosity increase at specified storage temperature No. Ambient of days temperature 30° C. 10° C. 0 100% 100% 100% 1 165% 269% 224% 2 179% 357% 221% 3 183% 374% 225% 7 200% 488% 224% 14  216% 488% 236% 35  291% 488% 240%

(29) The data shows that the first comparative formulation has a relatively low viscosity increase at low and ambient temperatures as the viscosity stays within 300% of the original viscosity. However, at a high temperature, the viscosity increase is at an unacceptable level over 300% of the original viscosity after two days which would mean that the formulation would not be suitable for summer use. It is not practical to have different formulations for different times of year due to the unpredictability of the weather and because of the difficulty of matching the properties of different formulations.

COMPARATIVE TEST EXAMPLE 10

(30) The gelation speed of the comparative plasticiser formulations which are exemplified in Comparative Examples 5 to 9 was measured as described in Test Example 4 and the results are shown in Table 10.

(31) TABLE-US-00010 TABLE 10 Comparative Example Inflection point (° C.) 5 77.44 6 86.52 7 83.33 8 78.74 9 79.81

(32) (c) The data shows that the comparative formulations have an acceptable inflection point of lower than 90° C. such that they are suitable for use in an industrial production line.