Sulfoaroyl end-capped ester oligomers suitable as soil-release agents in detergent compositions and fabric-conditioner articles

Claim 2

A composition useful as a soil-release agent in domestic laundry operations comprising oligomeric or polymeric esters preferably having molecular weights from 500 to 20,000, said esters having terminal units and a substantially linear backbone, characterized in that: the terminal units comprise sulphoaroyl end-cap units and the substantially linear backbone comprises: (a) unsymmetrically substituted oxy-1,2-alkyleneoxy units, preferably oxy-1,2-propyleneoxy or oxyethyleneoxy/­oxy-1,2-propyleneoxy mixtures, and (b) - (C₆H₄) - units, preferably terephthaloyl; at a mole ratio of unsymmetrically substituted oxy-1,2-alkyleneoxy units : - (C₆H₄) - units from 2:1 to 1:24.

Claim 3

A composition according to Claim 1, further characterized in that the composition is water-soluble or water-dispersible and comprises from 10% to 100% by weight of said substantially linear, sulphoaroyl end-capped ester.

Claim 4

A composition according to Claim 1 or 2 wherein said substan­tially linear, sulphoaroyl end-capped ester is characterized in that said sulphoaroyl end-capping units are sulphobenzoyl end-­capping units, and in that, per mole, the ester comprises: A) i) from 1 to 2 moles, preferably 2 moles, of sulphobenzoyl end-capping units of the formula (MO₃S)(C₆H₄)C(O)-, preferably in ortho- or meta- form, wherein M is a salt-forming cation, preferably sodium; ii) from 2 to 50 moles of oxy-1,2-propyleneoxy units or oxyethyleneoxy/ oxy-1,2-propyleneoxy -unit mixtures; respecting an oxyethyleneoxy : oxy-1,2-propyleneoxy mole ratio from 10:1 to 0:1; and iii) from 1 to 40 moles of terephthaloyl units; or B) units as specified in A) i)-iii), together with iv) from 0.02 to 30 moles of 5-sulphoisophthaloyl units of the formula -(O)C(C₆H₃)(SO₃M)C(O)- wherein M is a salt-forming cation, preferably sodium; or C) units as specified in A) i)-iii), together with v) from 0.02 to 25 moles of poly(oxyethylene)oxy units of the formula -(OCH₂CH₂) n O- wherein the average degree of ethoxylation, n, ranges from about 2 to about 100; or D) units as specified in A) i)-iii), together with iv) from 0.02 to 30 moles of 5-sulphoisophthaloyl units of the formula -(O)C(C₆H₃)(SO₃M)C(O)- wherein M is a salt-forming cation, preferably sodium and v) from 0.02 to 25 moles of poly(oxyethylene)oxy units of the formula -(OCH₂CH₂) n O- wherein the average degree of ethoxylation, n, ranges from about 2 to about 100; wherein the mole ratio iv):v) is from 29:1 to 1:29.

Claim 5

A composition according to any of Claims 1-3, comprising: A) at least 50% by weight of said substantially linear, sulpho­aroyl end-capped ester, the molecular weight of which is preferably from 600 to 2,000; wherein the substantially linear, sulphoaroyl end-capped ester is further characterized by the empirical formula (CAP) x (EG/PG) y (T z ) wherein (CAP) represents the sodium salt form of said sulphobenzoyl end-­capping units (i); (EG/PG) represents said oxyethyleneoxy/­oxy-1,2-propyleneoxy units (ii), the EG:PG mole ratio preferably being from 1:1 to 7:1; (T) represents said tere­phthaloyl units (iii); x is from 1 to 2 and is preferably 2; y is from 2.25 to 9 and is preferably 8 or less; and z is from 1.25 to 8 and is preferably 7 or less; or B) at least 25% by weight of said substantially linear, sulpho­aroyl end-capped ester, the molecular weight of which is preferably from 800 to 2,000; wherein said composition the substantially linear, sulphoaroyl end-capped ester is further characterized by the empirical formula (CAP) x (EG/PG) y (T z )-­(SIP) q wherein (CAP) represents the sodium salt form of said sulphobenzoyl end-capping units (i); (EG/PG) represents said oxyethyleneoxy/ oxy-1,2-propyleneoxy units (ii), the EG:PG mole ratio preferably being from 0:1 to 7:1; (T) represents said terephthaloyl units (iii); (SIP) represents the sodium salt form of said 5-sulphoisophthaloyl units (iv); x is from 1 to 2 and is preferably 2; y is from 2.25 to 39 and is preferably greater than 3 and is most preferably 14; z is from 1 to 34 and is most preferably 11; and q is from 0.05 to about 18 and is preferably 2 or less; or C) at least 25% by weight of said substantially linear, sulpho­aroyl end-capped ester, the molecular weight of which is preferably from 2,000 to 12,000; wherein said composition the substantially linear, sulphoaroyl end-capped ester is further characterized by the empirical formula (CAP) x (EG/PG) y (T z )-­(E n ) r wherein (CAP) represents the sodium salt form of said sulphobenzoyl end-capping units (i); (EG/PG) represents said oxyethyleneoxy/ oxy-1,2-propyleneoxy units (ii), the EG:PG mole ratio preferably being from 0:1 to 7:1; (T) represents said terephthaloyl units (iii); (E n ) represents said poly­(oxyethylene)oxy units (v), the degree of ethoxylation n being from 2 to 100, preferably 30 to 85, most preferably about 77; x is from 1 to 2 and is preferably 2; y is from 2.25 to 39 and is preferably 17 or less and is most prefer­ably 4 to 8; z is from 1.25 to 34 and is preferably 18 or less and is most preferably 4 to 8; and r is from 0.05 to 10 and is preferably 0.5 to 2 and is most preferably 1; wherein x, y, z, q, and r represent average numbers of moles of the corresponding units per mole of the ester.

Claim 6

A composition according to either of Claims 3 or 4, which is further characterized in that it comprises an analytically detect­able amount of a conventional transesterification catalyst; and wherein said said sulphobenzoyl units are further characterized as units deriving from a sodium salt of sulphobenzoic acid or from a sodium salt of its C₁-C₄ alkyl carboxylate esters; said tere­phthaloyl units are further characterized as units deriving from dimethylterephthalate; said oxy-1,2-alkyleneoxy units are further characterized as units deriving from 1,2-propylene glycol or 1,2-propylene glycol/ethylene glycol mixtures; said sulphoiso­phthalate units, when present, are further characterized as units deriving from a sodium salt of dimethyl-5-sulphoisophthalate; said poly(oxyethylene)oxy units, when present, are further character­ized as units deriving from a polyoxyethylene glycol having an average degree of ethoxylation of from about 30 to about 85.

Claim 7

A process for preparing a composition useful as a soil release agent in domestic laundry operations, said composition being in accordance with any of Claims 1-5, comprising mixing, transesterifying and oligomerising in the molten state, reactants comprising at least one sulphobenzoyl end-capping reactant, at least one glycol reactant and at least one aryldicarboxylate reactant, said process further being characterized in that: a) said transesterification and oligomerization are con­ducted in one or more steps in the presence of a cata­lytic amount of at least one conventional polyester transesterification and oligomerisation catalyst, using conventional vacuum or inert gas sparging techniques to maintain forward reaction; b) said sulphobenzoyl end-capping reactant is selected from the group consisting of sulphobenzoic acid derivatives of the formula (MO₃S)(C₆H₅)C(O)OR wherein M is a salt-­forming cation and R is H or a C₁-C₄ alkyl group; c) said glycol reactant is selected from the group consist­ing of 1,2-propylene glycol and mixtures thereof with ethylene glycol having a 1,2-propylene glycol: ethylene glycol molar ratio ranging from about 1:7 to about 1:0; d) said aryldicarboxylate reactant is selected from the group consisting of dimethyl terephthalate and tere­phthalic acid; and e) said reactants are combined in a molar ratio of glycol reactant to aryldicarboxylate reactant ranging from about 10:1 to about 1.5:1 and of glycol reactant to sulphobenzoyl end-capping reactant ranging from about 40:1 to about 1.5:1; all provided that a homogeneous melt is formed at temperatures ranging from about 150 to about 260°C when a high ratio of ethylene glycol to 1,2-propylene glycol is used or at temperatures ranging from about 150 to about 240°C when ethylene glycol is not used in said process; and provided that said sulpho­benzoyl end-capping, glycol and aryldicarboxylate reactants are selected and reacted subject to the condition that during said process no component of the reaction mixture present, as added or as formed at levels in excess of about 20% by weight, remains unmelted or is subjected to thermal decomposition.

Claim 10

A method according to Claim 8, wherein said conventional detersive ingredients comprise one or more conventional anionic surfactants; said soil release agent is present at a level of from 5 to 30 ppm in said aqueous laundry liquor; and said aqueous laundry liquor has a pH from 7 to 11.

Claim 11

A method according to Claim 9, wherein said fabrics are subjected to two or more cycles comprising the ordered sequence of steps: a) contacting said fabrics with said aqueous laundry liquor in a conventional automatic washing-machine for periods ranging from 5 minutes to 1 hour; b) rinsing said fabrics with water; and c) line- or tumble-drying said fabrics.