EP0510879A2

EP0510879A2 - Liquid softener

Info

Publication number: EP0510879A2
Application number: EP92303461A
Authority: EP
Inventors: Toru Hayase; Kazutaka Shiratsuchi; Junichi Inokoshi; Masaaki Yamamura
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 1991-04-26
Filing date: 1992-04-16
Publication date: 1992-10-28
Also published as: EP0510879A3; MX9201827A

Abstract

A liquid softener capable of imparting excellent softness and resiliency to various fibers and textiles and having an excellent storability which comprises (a) an amine having 1 or 2 ester group(s) and at least two straight-chain or branched, saturated or unsaturated hydrocarbon groups having 11 to 23 carbon atoms in the molecule and neutralized with an inorganic acid or an organic acid, and (b) an alkylamine polyether compound selected from the group consisting of compounds represented by following general formulae (I) to (III) and/or (c) a compound having a long-chain hydrocarbon group, a nitrogen atom and at least one member selected from the group consisting of an ester group, an amide group and an imidazoline skeleton in the molecule :

wherein R₃ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 8 to 24 carbon atoms, p₁+p₂+p₃+p₄ is a number of 0 to 60 and q₁+q₂+q₃+q₄ is a number of 0 to 60 with the proviso that p₁+p₂+p₃+p₄+q₁+q₂+q₃+q₄ ≥ 1.

Description

The present invention relates to a softener. In particular, the present invention relates to a liquid softener for domestic use capable of imparting excellent softeness and spring or resiliency (fluffiness) to various fibers and textiles.
Most domestic softeners now available on the market comprise, as the main ingredient, a quaternary ammonium salt having one or two long chain alkyl group(s) in the molecule, since even a small amount of quaternary ammonium salt displays an excellent softening effect towards various fibers and textiles.
Although the quaternary ammonium salt has a remarkable softening effect on cotton, its effect on synthetic fibers such as acrylic fibers, polyesterfibers and polyamide fibers is inadequate. Therefore the above-described domestic softeners tend to be used on such fibers at a high concentration, and the resiliency and feel of the treated clothes are thus often impaired.
When these softeners are stored for a long time, they tend to thicken orgel, particularly at low temperatures, or they tend to separate into different phases.
Therefore, substances other than the softening component, such as polyoxyethylene nonionic surfactant, an electrolyte and a solvent are required to stabilize the softeners, although their effect is still insufficient.
Softeners comprising the aforementioned quaternary ammonium salt as the main ingredient are available on the market usually in the form of a 4 to 20 wt.% dispersion of the quaternary ammonium salt.
However, the quaternary ammonium salt, having strong hydrophobic properties, is not easily dispersible in water and, as a result, it tends to become deposited unevenly on the clothing being treated. Although the commercially available softeners contain various additives in addition to the quaternary ammonium salt in order to improve their disperisibility in water, their effect is still insufficient.
Liquid softeners containing an amine as the softening ingredient are already known. For example, GB-1,514,276 discloses a composition for softening fibers which comprised a long-chain alkylamine such as a methyl di(hardened tallow alkyl)amine. US-4,446,034 discloses a finishing agent for fibrous materials to impart smoothness and excellent touch to the fibers which comprises an acylated alkanolamine, a water-soluble quaternary ammonium salt and a fatty acid ester. US-4,776,965 discloses a softener having a high disperisibility which comprises a quaternary ammonium compound, a higher fatty acid and a hydroxylated lower alkyl polyamine polyglycol ether. US-4,724,089 discloses a stable aqueous dispersion for treating textiles which comprises a di(higher alkyl) cyclic amine and a Bronsted acid. US-4,913,828 discloses a softening composition comprising a di(long chain alkyl)amine/anoinic surfactant ion pair complex, a non-silicone wax and a liquid carrier. EP-332,270 discloses a conditioning composition for cloth which comprises an amine such as a condensate of a hydroxylated lower alkyl alkylene diamine with a higherfatty acid and an amphoteric conditioning agent for cloth. US-4,869,836 discloses a softener comprising a di(long chain alkyl) amine/polyfunctional carboxylic acid complex and a conditioning composition for imparting antistatic properties to cloth. US-4,045,361 discloses a cloth conditioning composition which comprises an antistatic agent comprising a mono- or di(long chain alkyl)alkylenediamine and a quaternary ammonium softening agent. However, the effects of the softeners containing these amines are still insufficient.
Recently there have been loud cries for for prevention of environmental pollution all over the world. Thus in the field of softeners, it is now desired to use an ingredient having excellent biodegradability.
However, the effects of the aforementioned amine-containing softeners are also insufficient in this respect.
The present invention provides a liquid softener comprising or essentially consisting of (a) an amine having one or two ester group(s) and at least two straight-chain or branched, saturated or unsaturated hydrocarbon groups having 11 to 23 carbon atoms in the molecule and neutralized with an inorganic acid or an organic acid, and 5 to 100% by weight, based on the component (a), of (b) an alkylamine polyester compound selected from compounds represented by the following general formulae (I) to (III) and/or 1 to 150% by weight, based on the component (a), of (c) a compound having a long-chain hydrocarbon group, a nitrogen atom and at least one member selected from an ester group, an amide group and an imidazoline skeleton in the molecule:

wherein R ₃ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 8 to 24 carbon atoms, p ₁ + P ₂ + P ₃ + p ₄is an integer from 0 to 60 and q + + q₂ + q ₃ + q ₄is an integer from 0 to 60 with the proviso that p₁ ⁺ p ₂ ^{+ p} ₃ ⁺P₄ ^{+ q} ₁ ^{+ q} ₂ ^{+ q} ₃ ^{+ q} ₄ >1.
Typical examples of component (a) to be used in the present invention include compounds produced by neutralizing an ester amine with an inorganic acid such as hydrochloric acid and sulfuric acid or an organic acid such as acetic acid, glycolic acid, lactic acid, citric acid, maleic acid, fumaric acid and toluenesulfonic acid, the ester amine being produced by reacting an alkanolamine such as triethanolamine, tripropanolamine, N-methyldiethanolamine, N-methylpropanolamine and an N-(long chain alkyl)diethanolamine with a fatty acid having 12 to 24 carbon atoms or the methyl ester thereof. The fatty acids to be used in this reaction are usually those derived from natural oils and fats such as coconut oil, palm oil, tallow, rapeseed oil and fish oil, and chemically synthesized fatty acids are also usable.
The ester amine compounds which are precursors of component (a) are preferably those having one or two ester groups, particularly preferably those having one or two ester group(s) in the following form:

and/or

wherein R₁ and R_Z each represent a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, and two straight-chain or branched, saturated or unsaturated hydrocarbon groups having 11 to 23 carbon atoms.
The ester amine compound as a precursor of component (a) includes those of the following general formulae (IV) to (VII) as particularly preferably examples thereof.

wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3,
wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m and n each represents 2 or 3,
wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, and
wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3.

Among the above-described ester amine compounds, those of the above formula wherein R₁ and R₂ each represent an alkyl group or an alkenyl group having at least 14 carbon atoms are desirable, and those of the above formula wherein R₁ and R₂ each represent an alkyl group or an alkenyl group having at least 15 carbon atoms are still more desirable.
The component (a) may be used either singly or in the form of a mixture of two or more of them.
The amount of the component (a) is preferably 1 to 30% by weight, more preferably 4 to 30% by weight and particularly preferably 10 to 25% by weight, based on the entire liquid softener of the present invention.
It is a feature of component (a) having an ester group in the molecule to be used in the present invention that it has a high biodegradability and is usable as an ingredient which is harmless to the physical environment.
The alkylamine polyether compound to be used as component (b) of the liquid softener of the present invention is selected from the compounds represented by the aforementioned general formulae (I) to (III).
The alkylamine polyether compounds can be produced by the addition reaction of a corresponding amine with propylene oxide and/or ethylene oxide. Although the order of the addition is not limited, propylene oxide is desirably added at first from the viewpoint of ease of synthesis.
As the component (b), an alkylamine polyether compound which p₁ + p₂ + p₃ + _P4 in the aforementioned general formulae (I) to (III) is an integer from O to 20 and/or q₁ + q₂ + q₃ + q₄ in the aforementioned general formulae (I) to (III) is an integer from 0 to 40 is preferable.
The component (b) may be used either singly or in the form of a mixture of two or more of them.
The amount of the component (b) is 5 to 100% by weight, preferably 6 to 70% by weight and more preferably 20 to 35% by weight, based on the component (a) (from the economic point of view, 20 to 35% by weight is particularly preferred).
The compound to be used as the component (c) in the present invention is a compound having a long-chain hydrocarbon group, a nitrogen atom and at least one member selected from an ester group, an amide group and an imidazoline skeleton in the molecule.
The compounds to be used as the component (c) in the present invention can be easily synthesized from alcohols or amines.
Typical examples of the component (c) include those derived from N-methyldiethanolamine, imidazoline derivatives and aminoethylethanolamine derivatives. Particularly preferred are compounds of the following general formulae (VIII) to (XII):

wherein R₄ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3,
wherein R₄ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m and n each represents 2 or 3,
wherein R₅ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 9 to 23 carbon atoms,
wherein R₅ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 9 to 23 carbon atoms,
wherein R₅ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 9 to 23 carbon atoms, and m represents 2 or 3

Among them, those having an alkyl group or an alkenyl group of a long hydrocarbon chain having at least 12 carbon atoms are preferred.
Component (c) may be used either singly or in the form of a mixture of two or more of them.
The amount of component (c) is 1 to 150% by weight, preferably 5 to 100% by weight and more preferably 10 to 50% by weight, based on the component (a) (from the viewpoint of storability of the liquid softener, 5 to 50% by weight is particularly preferred).
The liquid softener of the present invention can be prepared, for example, by slowly adding a molten amine as component (a) or a solution of the amine having a high concentration to an aqueous solution containing a neutralizing agent, i.e. an inorganic acid or an organic acid, and component (b), component (c), a silicone compound, a solvent, etc., with stirring or shear mixing, and then adding an inorganic electroyte, a colorant and a perfume. The inorganic electroyte may be previously added to the aqueous solution containing a neutralizing agent etc., or the silicone compound may be added after adding component (a). However, the method for the preparation of the liquid softener is not limited thereto but it can be prepared by other methods, also e.g. by adding a previously produced neutralized product (component (a)) or by the post-addition of the neutralized product.
The feel of the clothes softened with the softener of the present invention can be further improved without impairing their water absorption by further incorporating into the softener a silicone compound such as dimethylpolysiloxane itself or dimethyl-polysiloxane partially modified with an amino group or a polyoxyalkylene group, particularly preferably dimethylpolysiloxane partially modified with a polyoxyalkylene group. The amount of the silicone compound to be incorporated is preferably 0.3 to 5% by weight based on compnent (a).
Although the softening effect of the softener of the present invention is equivalent to that of a commonly- used softener comprising hardened tallow alkyldimethylammonium chloride as the main ingredient, it has been suprisingly found that the softener of the present invention imparts to the clothes a high resiliency (fluffiness) in addition to softeness.
When the softener of the present invention is produced in the form of an aqueous liquid softener, it is desirable for it to contain 0.05 to 0.4% by weight, based on the entire liquid softener, of an inorganic electrolyte such as sodium chloride, calcium chloride and magnesium chloride in order to regulate the viscosity.
Although the liquid softener of the present invention has good storage stability for a long period of time, its stability under severe conditions can be further improved by the incorporation of a nonionic surfactant such as a polyoxyethylene(5 to 50 mol)alkyl(C₁₂ to C₂₄)ether and a polyoxyethylene (5 to 50 mol)alkenyl(C₁₂ to C₂₄)ether, a solvent such as ethanol, propylene glycol and ethylene glycol, or urea. A known softener base such as an ester, a nonionic compound, a cationic compound, a long-chain alcohol and a long-chain fatty acid may be contained in the liquid softener of the present Invention.
A pigment or a dye can be used for Improving the appearance of the product and a fluorescent brightener can be used for whitening the finished textile, while a fragrance can be used for improving the appeal during the use of the product and after the finish
The softener of the present invention is capable of imparting sufficient softness and antistatic properties to various fibers and has an excellent biodegradability.
Non-limiting examples of softeners according to the invention will now be given.

Examples

The following Examples will further illustrate the present invention, which by no means limit the present invention.

Examples 1 to 11 and Comparative Examples 1 to 3

The Softeners listed in Table 3 comprising each of component (a) or component (a') for comparison specified in Table 1 and each component (b) specified in Table 2 were evaluated as will be described below

1) Evaluation of storability:

Each softener listed in Table 3 was hermetically closed and kept at -10°C, room temperature or 50°C for 20 days to evaluate the appearance and fluidity thereof under such a condition. The results are given in Table 3.

2) Evaluation of softness and resiliency:

(1) Treatment method:

2 kg of commercially available cotton towels and 1 kg of acrylic jerseys were washed repeatedly 5 times with a commercially available detergent "Attack" (registered trade name of Kao Corporation) in 3.5° DH hard water (30-f volume washing machine) to remove textile treatments. Then 1.5 g [in terms of the active ingredient, i.e. component (a) or (a')] of each composition listed in the Table 3 was added thereto and stirred at 25°C for 1 minute to conduct the treatment.

(2) Evaluation method:

The cloths treated as described above were air-dried indoors and then left to stand in an air-conditioned room at 25°C and 65% RH for 24 hours to evaluate the softness and resiliency of the cloths
The softness and resiliency were evaluated by the paired comparison method wherein cloths treated with 10 ml of a softener comprising 15% by weight of a di(hydrogenated tallow alkyl)dimethylammonium chloride were used as the control. The results of the evaluation were indicated as follows:

+2: softer or more resilient than the control,
+1: slightly softer or slightly more resilient than the control,
0: equivalent to the control,
-1: the control was slightly softer or slightly more resilient than the cloth treated with the softener of the present invention, and
-2: the control was softer or more resilient than the cloth treated with the softener of the present invention.

As apparent from the results, the liquid softeners of the present invention for clothes were substantially unchanged with time and were excellent. The softening effect of the softeners of the present invention were slightly better than or equivalent to that of the control, and the resilient effect of the cloth using the softeners of the present invention was better than or slightly better than that of the control.

Examples 12 to 24 and Comparative Examples 1, 4 and 5

The softeners listed in Table 5 comprising each of component (a) or component (a') for comparison specified in Table 1 and each component (c) specified in Table 4 were evaluated as described in Example 1.
As apparent from the results, the liquid softeners of the present invention for clothes were substantially unchanged with time and were excellent. The softening effect of the softeners of the present invention were slightly better than or equivalent to that of the control, and the resilient effect in the cloth using the softeners of the present invention was better than or slightly better than that of the control.

Example 25

The liquid softener having the fllowing formulation was evaluated as described in Example 1.

[Liquid softener formulation]

This liquid softener gave excellent softness and resilience to a cloth. The storage stability and the dispersibility in water for rinse were also excellent.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A liquid softener comprising (a) an amine having one or two ester group(s) and at least two straight-chain or branched, saturated or unsaturated hydrocarbon groups having 11 to 23 carbon atoms in the molecule and neutralized with an inorganic or organic acid, and 5 to 100% by weight, based on the component (a), of (b) an alkylamine polyether compound selected from compounds represented by the following general formulae (I) to (III) and/or 1 to 150% by weight, based on the component (a), of (c) a compound having a long-chain hydrocarbon group, a nitrogen atom and at least one member selected from an ester group, an amide group and an imidazoline skeleton in the molecule:

wherein R ₃ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 8 to 24 carbon atoms, p 1 + ₂ 2 + _P3 + p ₄ is an integer from 0 to 60 and q 1 + q₂ ⁺ q₃ ⁺ q ₄ is an integer from 0 to 60 with the proviso that p₁ + p₂ + p₃ + p₄ + q₁ + q₂ + q₃ + q₄ ≥ 1.

2. The liquid softener according to Claim 1, wherein the component (a) is an amine having one or two ester group(s) in the following form:

wherein R₁ and R₂ each represent a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms,
and two straight-chain or branched, saturated or unsaturated hydrocarbon groups having 11 to 23 carbon atoms and neutralized with an inorganic acid or an organic acid.

3. The liquid softener according to Claim 1, wherein the component (a) is an amine selected from neutralized compounds of those represented by the following formulae (IV) to (VII):

wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3,

wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m and n each represents 2 or 3,

wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, and

wherein R₁ and R₂ each represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 11 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3.

4. The liquid softener according to Claim 1, wherein the component (c) is a compound selected from the compounds represented by the following general formulae (VIII) to (XII):

wherein R₄ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m represents 2 or 3,

wherein R₄ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group or a hydroxypropyl group, and m and n each represents 2 or 3,

wherein R₅ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 9 to 23 carbon atoms,

wherein R₅ represents a straight-chain or branched, saturated or unsaturated hydrocarbon group having 9 to 23 carbon atoms, and m represents 2 or 3.

5. The liquid softener according to Claim 1, the softener further containing at least one component selected from a silicone compound, an inorganic electrolyte, a nonionic surfactant, defoaming agent, a solvent and urea.

6. The liquid softener according to Claim 1. the softener further containing 0.05 to 0.4% by weight, based on the entire liquid softener, of an inorganic electrolyte.