The present invention relates to a softener composition.
Most of the commercially available softener compositions for fibers are compositions comprising a quaternary ammonium salt containing two long-chain alkyl groups in one molecule and being typified by a di(long-chain alkyl) dimethyl ammonium chloride.
However, the quaternary ammonium salt described above suffers from the problem that, residues formed during treatment are discharged into the environment such as a river, and most of them accumulate without biodegradation.
As an improved product addressing the above-mentioned problem, N-methyl-N,N-bis(long-chain alkanoyl oxyethyl)-N-(2-hydroxyethyl) ammonium methyl sulfate, N,N-dimethyl-N,N-bis(alkanoyloxyethyl) ammonium chloride or the like is commercially available. Although the biodegradability of the product is improved when compared to that of the quaternary ammonium salt described above, the improved product cannot be said to have a sufficient softening effect.
On the other hand, water saving type laundering machines have become popular in recent years. That is, a laundering and softening treatment are carried out with a smaller amount of water than is necessary for conventional machines. In the case of a softening treatment under such a condition, a softener into which the above-described quaternary ammonium salt is blended, as it is, suffers from the problem that the softening effect cannot be sufficiently obtained.
On the other hand, it is desirable from the viewpoint of a resource-, energy- or space-saving that the softener is highly concentrated. However, when the quaternary ammonium salt described above is blended, as it is, at a high concentration, there is the problem of a higher viscosity, gelation or separation during a storage.
As the prior art, JP-A 6-228875 discloses a softener composition comprising a di-long-chain quaternary ammonium salt and a di-long-chain amine in the ratio of from 99/1 to 85/15 and JP-A 5-195432 discloses an ester amide-based quaternary salt or a tertiary amine/alkanol amide neutralized salt. However, the creaky feeling of clothes and so on cannot be removed using any one of the prior art compositions described above.
Accordingly, the object of the present invention is to provide a softener composition which has a favorable softening effect even it is used with a small amount of water, it gives a minimal creaky feeling to fabrics, it has a high biodegradability, and it shows an excellent storage stability even though it is blended at a high concentration.
The present inventors have found that the problem described above can be solved by using a cationic surfactant having at least two selected from long-chain alkyl and alkenyl groups in combination with a specific amine or a salt thereof. And then, the present inventors have completed the present invention.
That is, the present invention provides the softener composition which comprises a component (A) containing an amine represented by the following formula (I), a salt thereof or a mixture of the same and a component (B) containing a compound represented by the following formula (II-2) as the essential component and optionally containing at least one of the compounds represented by the formulae (II-1) and (II-3), wherein the ratio of the component (A) to the component (B), namely (A)/(B), by weight is from 2/8 to 8/2: 
wherein R1 and R2 are the same or different and each of R1 and R2 represents a hydrogen atom, a C1-3 alkyl group, xe2x80x94(CmH2mO)pxe2x80x94H, xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3 or xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3; m, n and q are the same or different and each of m, n and q represents an integer of 1 to 6; p represents a number selected from 1 to 10; R3 represents a linear or branched C5-22 alkyl or alkenyl group; X represents xe2x80x94OCOxe2x80x94 or xe2x80x94COOxe2x80x94; and Y represents xe2x80x94NHCOxe2x80x94, xe2x80x94CONHxe2x80x94, xe2x80x94Oxe2x80x94 or xe2x80x94CH2xe2x80x94; provided that at least one of R1 and R2 is xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3 or xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3; 
wherein R4 represents a C1-3 alkyl group or xe2x80x94(CmH2mO)pxe2x80x94H; R5 represents a C6-22 alkenyl group, xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3 or xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3; each of m, n, p, q, R3, X and Y has the same meaning as defined above; Zxe2x88x92 represents an anion; and one of the plural R4""s and R5""s may be same as or different from another.
In the present invention, it is preferable that the content of the component (B) is 11 to 50% by weight as compared with the softener composition, provided that the component (A) is represented by the following formula (a-1) and excluding case that the component (B) is represented by the following formula (b-1): 
The component (A) in the present invention is preferably an amine represented by the formula (III), a salt thereof or a mixture of the same: 
wherein R1 represents a hydrogen atom, a C1-3 alkyl group, xe2x80x94(CmH2mO)pxe2x80x94H, xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3 or xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3; m, n and q are the same or different and each of m, n and q represents an integer of 1 to 6; p represents a number selected from 1 to 10; R3 represents a linear or branched C5-22 alkyl or alkenyl group; X represents xe2x80x94OCOxe2x80x94 or xe2x80x94COOxe2x80x94; Y represents xe2x80x94NHCOxe2x80x94 or xe2x80x94CONHxe2x80x94; and R2 represents xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3.
The amine represented by the formula (I) or (III) is synthesized by acylation of an amino alcohol or diamino alcohol represented by the formula (IV) with a fatty acid or a lower alkyl ester thereof: 
wherein R1xe2x80x2 and R2xe2x80x2 are the same or different and each of R1xe2x80x2 and R2xe2x80x2, represents a hydrogen atom, a C1-3 alkyl group, xe2x80x94(CmH2mO)pxe2x80x94H or xe2x80x94CqH2qxe2x80x94NH2; each of m, n, p and q has the same meaning as defined above; and at least one of R1xe2x80x2 and R2xe2x80x2 is xe2x80x94(CmH2mO)pxe2x80x94H or xe2x80x94CqH2qNH2. The degree of acylation in total is preferably 1.2 to 2.5 and more preferably 1.5 to 2.3. For example, the amino alcohol represented by the formula (IV) may be triethanolamine, N-methyldiethanolamine, N-methyl-N-(2-hydroxyethyl)propanediamine or N,N-di(2-hydroxyethyl) propanediamine or the like. The number of carbon atoms in an acyl moiety in the fatty acid or the lower alkyl ester thereof for use is preferably 6 to 22 and more preferably 8 to 18. For example, a fatty acid from a coconut, a tallow fatty acid, a hardened (or hydrogenated) tallow fatty acid, stearic acid from a palm, hardened stearic acid from a palm or a lower alkyl ester thereof is particularly preferable. Further, a fat and/or oil such as a coconut oil, a tallow, a hardened tallow, a palm-stearin and a hardened palm-stearin may be also used.
The salt of the amine can be synthesized in a usual manner by neutralization with an inorganic or organic acid such as hydrochloric acid (an aqueous solution of hydrogen chloride), sulfuric acid, phosphoric acid, glycolic acid, lactic acid, tartaric acid, citric acid and succinic acid.
The amine represented by the formula (I) or (III) is preferably represented by the formula (Ia), (Ib), (Ic) or (Id) and more preferably represented by the formula (Ic) or (Id): 
wherein R3 has the same meaning as defined above and R6 represents a methyl or hydroxyethyl group; 
wherein R3 has the same meaning as defined above; 
wherein each of R3 and R6 has the same meaning as defined above and i represents 2 or 3; 
wherein each of R3 and i has the same meaning as defined above.
The cationic surfactant used as the component (B) in the present invention contains a component represented by the formula (II-2) as the essential component and may further contain a component or components represented by the formula (II-1) and/or (II-3). The component (II-2) is preferably represented by the formula (IIa) or (IIb), in particular: 
wherein R4 represents a C1-3 alkyl group or xe2x80x94(CmH2mO)pxe2x80x94H; R5 represents a C6-22 alkyl or alkenyl group, xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3 or xe2x80x94CqH2qxe2x80x94Yxe2x80x94R3; each of m, n, p, R3, X and Y has the same meaning as defined above; Zxe2x88x92 represents an anion; and one of the plural R4""s and R5""s may be same as or different from another; 
wherein R3 has the same meaning as defined above; R7 represents a methyl or hydroxyethyl group; and Z1xe2x88x92 represents a chloride ion or methyl sulfate ion; 
wherein each of R3, R7 and Z1xe2x88x92 has the same meaning as defined above and r represents 2 or 3.
For example, the cationic surfactant represented by the formula (IIa) or (IIb) is synthesized by acylation of an amino alcohol such as triethanolamine, N-methyldiethanolamine, N-methyl-N-(2-hydroxyethyl)propanediamine and N,N-di(2-hydroxyethyl) propanediamine with a fatty acid or a lower alkyl ester thereof and further quaternarization of the resultant product with a quaternarizing agent such as methyl chloride (or chloromethane) and dimethyl sulfate. The degree of acylation in total is preferably 1.1 to 2.8 and more preferably 1.5 to 2.5. The fatty acid or the lower alkyl ester thereof for use is preferably the above-mentioned one.
Preferably, the present invention provides the softener composition wherein the component (B) is a cationic surfactant containing a component represented by the formula (II-5) as the essential component and optionally containing a component represented by the formula (II-4) or (II-6): 
wherein R4 represents a C1-3 alkyl group or xe2x80x94(CmH2mO)pxe2x80x94H; R5xe2x80x2 represents a C6-22 alkyl or alkenyl group or xe2x80x94CnH2nxe2x80x94Xxe2x80x94R3; each of m, n, p, R3 and X has the same meaning as defined above; Zxe2x88x92 represents an anion; and one of the plural R4""s and R5""s may be same as or different from another.
The ratio of the component (A) to the component (B), namely (A)/(B), by weight in the softener composition of the present invention is from 2/8 to 8/2, preferably 3/7 to 7/3 and particularly preferably 4/6 to 6/4. If (A)/(B) is less than 2/8, the softener composition shows an inferior storage stability, while (A)/(B) is more than 8/2, it shows an inferior softening effect.
The components (A) and (B) can be formed into the liquid softener composition of the present invention by dispersing them in a total amount of 3 to 50% by weight in water. In this case, the components (A) and (B) may be mixed and then introduced into water or they may be introduced one after another into water. Alternatively, the respective components may be separately dispersed in water and then mixed.
The softener composition of the present invention has pH value of preferably 1.5 to 6.0 and more preferably 2.0 to 5.0 at 25xc2x0 C. in view of a dispersibility and storage stability of the amine compound.
A higher alcohol or higher fatty acid can be added in order to further improve a softening performance. A lower alcohol such as ethanol and isopropanol, glycol or polyol as well as an ethylene oxide or propylene oxide adduct thereof can be added as a storage stabilizer. Furthermore, a usual nonionic surfactant, an inorganic salt, a pH adjuster, a hydrotropic agent, a perfume, a defoaming agent, a pigment and the like can be added if necessary.