JPH0284925A - Wiped out article - Google Patents

Abstract

PURPOSE: To enable to clean a dirt surface under existence of water, by constructing a wiper from a first base body and a second base body and retaining a solid surfactant to hold a specific craft temperature between those base bodies. CONSTITUTION: A solid surfactant to form a liquid crystal phase by contact with water under at least up to 30 deg.C above craft temperature and/or having a craft temperature not lower than 20 deg.C is put in between a first base body and a second base body. A possible form of the surfactant is C14 -C16 sulfobetaine which easily forms a hexagonal system liquid crystal phase and is dried into a crystalline solid. A preferable surfactant is mild to skin, which is monoalkyl sulphosuccinate or aliphatic acylisethionate with 8-22, preferably 10-16 alkyl or acyl groups. Sodium cocoilsethionate with 26 deg.C of the craft temperature is especially preferable. The base body layers supply wiping surfaces and gives strength and unity to the wiper.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a wiping article suitable for use in the presence of water to clean soiled surfaces.
rticle). Wiping articles can be used to clean hard surfaces, particularly hard surfaces found in domestic kitchens and bathrooms, and to clean human body surfaces, for example when showering.

For example, D E2325176 (Schickeda
nz), EP66463 (Llnilev
er) and E P 211664 (Uni 1eve
A number of impregnated wiping articles for hard surfaces have been proposed, such as r). Also, E P685
16 (Barbey & Heeken) and U.S.
4303543 (Procter & Ga11ble
), impregnated "cloths" for washing the surfaces of the human body have also been proposed. E P 113191
1 (Unilever) is related to both applications.

For example, in EP 66463 and EP 211664 mentioned above, it is proposed to provide a hard surface wiping article as a sandwich structure having a first and second substrate layer sandwiching a core of concentrated surfactant.

The problem that arises with both Noriharu wiping articles mentioned above is that when used in the presence of large amounts of water, the impregnated soap or detergent active material leaches out prematurely, leaving the article prematurely free of soap or detergent active material. This means that the material is consumed. This is evident, for example, when a hard-surface towel wears out after only one use, or when a towel intended for use under the shower does not last even once.

In E P 161911, the release of the impregnated detergent active compound is delayed by sandwiching the detergent active using a moisture barrier part with the same pattern as the detergent active, thereby slowing the leaching of the detergent active from the rag. is suggesting.

Our EP211664, supra, proposed a wiping article for hard surfaces that entrapped a surfactant within a polymeric matrix material, thereby imparting sustained release properties.

Here, we have discovered that the release of surfactants can be delayed in a more in-depth manner.

According to the invention, (1) the surfactant (i) forms a liquid crystal phase in contact with water at a temperature above the Kraft temperature, up to at least 30°C, and/or (ii) has a Kraft temperature of above 20°C; comprising a first substrate and a second substrate, having the solid surfactant sandwiched therebetween, the contaminated surface is treated with W4 in the presence of water. A substantially dry to the touch wiping article suitable for use for cleaning is provided.

When using a surfactant with a kraft temperature of 20°C or higher (which is a relatively high kraft temperature), the surfactant will have low solubility when contacted with water at temperatures up to the kraft temperature. , it will dissolve slowly. This delays the release of the surfactant when the wiping article is used with cold or lukewarm water.

However, when the surfactant comes into contact with water it exhibits a liquid crystalline phase, in particular cubic or hexagonal (hexaao) phase.
It is preferred to form a most preferably hexagonal liquid crystal phase of na I ). Such a liquid crystalline phase will form at an appropriate point in the concentration gradient between the surfactant in the wipe article and the water that permeates into the article.

The formation of a hexagonal liquid crystal phase when water contacts the solid surfactant is particularly effective in slowing the release of the surfactant from the wiping article. This is because the liquid crystal phase is very viscous and dissolves itself slowly in water,
In addition, there is a temporary retention between the remaining solid surfactant and water.
This is because it forms a film.

Formation of a liquid crystal phase acts to retard dissolution when the wipe article is contacted with water at any temperature where a liquid crystal phase is present. This temperature is preferably from 20°C or the kraft temperature of the surfactant, whichever is higher, to at least 30°C, preferably 35 or 40°C, and more preferably up to 50°C, which is about the highest temperature that the hand can withstand. be. Therefore, in embodiments of the invention in which the liquid crystalline phase retards dissolution, the kraft temperature of the surfactant is less than 20°C, and the liquid crystalline phase is present in a temperature range of at least 20°C to 30°C, or the kraft temperature of the surfactant is is 20°C or higher, and a liquid crystal phase exists over a temperature range of at least 30°C from the Kraft temperature.

It is important that the surfactant forms foam in the water.

This is because the foaming allows the user to visually confirm the presence of the surfactant. For surfactants with fairly high Kraft temperatures, a fairly high critical micelle concentration is desirable for the surfactant to foam. The critical micelle concentration is at least 2 nHo1e/j! , more preferably at least 4 or 5 l1hole/R.

The surfactant needs to be in solid form so that it remains in place within the wipe article when the article is dry.

The surfactant itself is at 20°C, preferably at least 25°C.
Particularly preferred are those which exist as solids at temperatures up to This allows the introduction of a solid, concentrated surfactant between the two layers of the substrate and keeps the surfactant in place during storage of the dry wipe article before use. Solid surfactants are preferably non-sticky and more preferably exist as dry particles at a temperature of 20°C, preferably at least 25°C.

Surfactants are often used in particulate form as particles trapped between two substrate layers.

When the surfactant is used in particulate form, the dissolution rate can be adjusted within a range by selecting the size of the surfactant particles.

The surfactant can be a non-soap detergent and several types are available. One possible form of surfactant is C14
~C16 sulfobetaine. These easily form a hexagonal liquid crystal phase upon contact with water, and become a crystalline solid when dried.

Preferred surfactants of the present invention are those that are invasive to the skin;
Examples are monoalkyl sulfosuccinates or fatty acyl isethionates in which the alkyl or acyl group has 8 to 2211!11 preferably 10 to 16 carbon atoms. This anionic surfactant is a solubilizing cation (so
alkali metal ions are preferred.

In commercially available form, these types of surfactants often contain fatty acids and other impurities, but this does not diminish the usefulness of the present light.

Particularly preferred is sodium cocoyl isethionate having a Kraft temperature of 26°C. Above the Kraft temperature, both hexagonal and lamellar liquid crystal phases are formed in the concentration gradient between surfactant and water. The use of this surfactant has limited solubility in water at temperatures below the Kraft temperature, thus reducing the rate of dissolution. Above the Kraft temperature, the hexagonal liquid crystal phase retards dissolution. A hexagonal liquid crystal phase exists from the Kraft temperature to 50°C or higher.

As mentioned above, a substrate layer is required for the present invention.

The base layer provides a wiping surface and adds strength and integrity to the article.

At least one substrate material must be permeable to water. Preferably, the base layer is a sheet of fibrous material.

Particularly preferred are nonwoven fibrous sheets. Cellulose fibers are particularly preferred because they absorb water quickly when used to clean soiled surfaces.

The substrate layer may also include other fibrous materials such as polyamides, polyesters, and polypropylenes or mixtures of such fibers, which are particularly useful in providing high wet strength articles.

The wet strength of the substrate layer material can also be increased by incorporating a suitable binder such as a styrene butadiene lattice or an acrylic binder or a polyvinyl acetate or polymer emulsion.

The absorbent substrate can be made from paper, where paper generally consists of relatively short lengths of cellulose fibers. Additives such as hydroxyethyl cellulose are used to increase wet strength.

The substrate layers may be the same or different. It may be advantageous to use different substrate layers, for example to choose one substrate material that provides good wet strength and another substrate material that provides good absorption. One preferred substrate material is a nonwoven material comprised of cellulose fibers, such as Hitsubishi T, a 100% copper ammonium spun rayon bonded nonwoven material with the following properties:
CF 408: Nominal basis weight <g/g) 82.5 Thickness <tm>
So.

Dry tensile strength: longitudinal direction of paper (N, /I) 63
5 Dry tensile strength: Paper width direction (N/n) 56
5 Wet tensile strength: machine direction of paper (N/l) 49
8 Wet tensile strength: transverse direction of paper (N/l) 44
7 Absorption Capacity (SF/9) 5 Another substrate material is 5tora+ene 715:50 or 5torale commercially available from Opparberg in Sweden with the following composition:
It is a non-woven material containing cellulose asi such as ne 717:50: % by weight Cellulose fiber (wood pulp) 33 Cotton linter 29 -
Yon
17boryamide 4 binder*17'' 5toralene 715:50&t7')
! J) I/binder t', 5tora+ene
717:50 contains a polyvinyl acetate binder.

5toralene 715:50 and 5toralene
The properties of ne 717:50 are as follows.

5tOralene 715:50 717:50 Nominal basis weight (9/go) so s.

Thickness (μ) 4
00 365 Dry tensile strength: longitudinal direction of paper (N/m
) 600 625 Dry tensile strength: Paper transverse direction (N
#e) 450 330 Wet tensile strength: Machine direction of paper (N/In) 300 205 Wet tensile strength: Horizontal direction of paper (N/1m) 250 95 Absorption capacity (9/
9) 4 Another example of a suitable substrate material is Basic 118211, 5cott P which is a 92% porosity random humidity V/XA* grade web paper.
Old-Loft 3051 commercially available from Aper
It is. This is a bulky porous sheet material with a high wickina rate.

The substrate layer may consist of a laminate of one or more layers, for example a W4 laminate of absorbent material with reinforcing material on the outer surface. Abrasive particles can be used on the outer surface of one or both of the substrate layers. The preferred abrasive particles are polyvinyl chloride granules. The use of granular abrasives on the external surface of wiping articles is described in our published European application E P211664.
It is described in.

Although abrasive materials are used on the outside of both substrate layers, different abrasive materials can be used so that one substrate layer provides a freer polishing surface than the other. However, it is preferred that one substrate layer has an abrasive agent and the other substrate layer has a smooth surface so that it can be polished after initial scrubbing on the abrasive side of the wiping article.

The two substrate layers and the intervening surfactant can be combined in a variety of ways. For example E P 664
63 and EP 112,654, the two layers can be heat-sealed to each other in a regular pattern or grid. or,
British Patent Application No. 8817727 filed at the same time as this application.
Concurrent application E case C326 claiming priority from 4.
It is also possible to apply the substrate layer using sintered polyethylene in the method described in 3].

In these examples, wiping articles were manufactured using standard techniques, with surfactant particles sandwiched between the substrate layers. One substrate layer consisted of the old Tsubishi TCF 408 described above and the other consisted of the old-Loft 3051 described above.

A 30c11 square of each substrate material was used to make the wipe article. Up to 2.5 g of polyethylene beads of 0.3 order were sprinkled onto the surface of one square of each substrate and then heated in an oven to melt the beads sufficiently to bond them to the substrate layer.

Next, the polyethylene coated surface of one substrate layer is
．． A portion of the powdered surfactant was sprinkled on a 5α×27.5 cm area, and then the other substrate layer was placed so that the polyethylene coated surfaces faced each other and sandwiched the surfactant. The assembly was then passed through heated rollers to heat seal the polyethylene layers.

Next, the periphery of the obtained laminate was cut to form a 28α square.

Wipe articles were made in this manner using several surfactant materials and several doses of each surfactant material. The surfactants used in these examples were: Sodium totisyl sulfate
dInterfacial PhenoIlena,
Hilton Rosen, Wiley 1978, Kraft temperature 16°C, critical micelle concentration 8 1lHol
Sodium dodecylsulfonate [in the same reference, Kraft temperature is 38°C, clinical micelle concentration is 10nHole/
11]; Sodium diC6-C8 alkyl sulfosuccinate [Kraft temperature 15-b Sodium cocoyl isethionate (^kzo Chel
Elfan AT 84G by Manufacturer [Craft temperature 26°C]. The critical micelle concentration of the main dodecyl component is approximately 6 mHo1e/j! Parris et al. reported in JAOC349649. This surfactant forms a hexagonal liquid crystal phase when contacted with water above the Kraft temperature. This isethion i
ll salt is ground commercially available noodles of this surfactant,
Different particle sizes obtained by sieving were used.

Articles made as described above using various surfactants were tested in a manner that determined how many times the surfactant could be wetted and squeezed before it was used up. This test was conducted as follows. 25 g of water (French rigid 10° tap water at a temperature of 35-+40°C) was poured over the wiped article and then wrung out.

Approximately half of the water from the article was squeezed out by squeezing. Put the squeezed water into a 100d measuring cylinder,
Shake for 5 seconds. Any surfactant leaching out of the wiping article should cause foaming. Sufficient foaming was considered when the amount of foam was greater than the amount of liquid in the measuring cylinder after 2 minutes in the device. This procedure was repeated until the foaming observed was not sufficient. The number of times of wetting and squeezing until foaming is insufficient is shown in the table below. The table also does not show the surfactant used and its particle size.

Number of times until surfactant is used up Surface per article Surface per article 0.2 g of surfactant per article 0.5 g of activator 1.0 g of activator Dodecyl sulfate average 0.4% Cocoyl isethionate i) 0.18- (), 35M 1i) 0.35-Jo, 5 atr iii) 0.5-1.0 yH +v) 1.0-t7 II *Does not meet the requirements of the present invention, as seen from the insufficient foam table For sodium dodecyl sulfate and dialkyl sulfosuccinate, increasing the amount of surfactant in the wipe article did not significantly increase the number of cycles to depletion, whereas for sodium cocoyl isethionate, increasing the amount of surfactant in the wipe article did not significantly increase the number of cycles to depletion. It was shown that increasing the amount of active agent increased the number of cycles to depletion and decreased the rate of dissolution of the surfactant.

The particle size of the isothionate also played a role. That is, the larger the particles, the more slowly they dissolved. When the isethionate particles were the largest, the rate of dissolution was slow and no adequate fK foam was obtained with 0.2 g of surfactant. Even if I added more of the larger ones, the lather was poor during the first wet and squeeze cycle.

Suitable wiping articles include particles with a particle size of 0.35s or less.
．． 1g and particle size 0.5-1. Om#I particles 0.4-0
．． No. 9 isethionate salt was used.

When the surfactant is sodium dodecyl 171M,
The wiping article seems to lather more than desired, except when the amount of surfactant in the wiping article is low (0.2 g).
I felt like it was a six. This was also demonstrated in wipe articles containing dialkyl sulfosuccinates as surfactants. When sodium cocoyl isethionate was used as the surfactant, this excessive foaming and apparent slimy feel were less evident than with the other two surfactants.

Example 2 A comparison was made between wiping articles made according to the general procedure described above using sodium dodecyl sulfate in one example and sodium dodecyl sulfonate in the other. Prior to article manufacture, both surfactants were screened to ensure that the surfactant particles were no larger than 0.5M.

Surfactant release from the article was measured in the following manner. 2
25 g of water at 5° C. (10° on the French scale of hardness) was poured onto the wiped article. The article was squeezed to squeeze out about half of the water in the article. I collected this water. Wet the item, squeeze it,
The cycle of collecting the squeezed water was repeated. Surfactant temperature in expressed water samples was determined by titration with the cationic surfactant hyamine.

The degree of foaming was also recorded. The results are shown in the table below.

Wet Dodecyl Sulfate Dodecyl Sulfonate The results with borderline poorly foamed sodium dodecyl sulfonate showed some experimental variation, particularly in the concentrations released into the water in the second and eleventh cycles. Changes were observed.

However, the results clearly indicate that sodium dodecyl sulfate, whose craft temperature is lower than the water temperature used in the test and is not present as a liquid crystalline phase at the test temperature, releases too much surfactant initially. in contrast,
Sodium dodecyl sulfonate had a Krafft point above the test temperature, slow surfactant release, no initial over-foaming, and adequate foaming with a significant number of wetting and squeezing cycles.

Example 3 Wipe articles were manufactured using the general procedure described above.

The surfactant used was sodium cocoyl isethionate with a particle size of 0.5-1 ffi#l.

Surfactant release was measured using the procedure of Example 2.

This test was performed twice, once with water at 25°C and once with water at 35°C.
Conducted twice.

The results are shown in the table below.

At 25° C. water, just below the insufficient foaming craft temperature, the surfactant was released regularly, similar to the results with sodium dodecyl sulfonate in Example 2.

Water at 35°C, above the kraft temperature, released the surfactant from the wipe-off article slightly faster than at 25°C.

Since at the test temperature the surfactant forms a liquid crystalline phase, the release is regular but distinct from the rapid release of dodecyl sulfate in Example 2.

Example 4 Wipe articles were made using various particle sizes of sodium cocoyl isethionate as used in Example 1.

Surfactant release upon initial wetting was tested using the procedure of Example 2. Tests were conducted using water at 35°C. The concentration of surfactant in the water squeezed out after initial wetting was measured, and the results are as follows.

0.5-1.0 darkness 0.5g Upper foaming 1.0-1.7m-0.5g Upper foaming 1.0-1.7 rntn 1.0-1.7m-0.5g Foaming on O3 Thus, the use of a large particle size along with a small amount of a small particle size delays the release and at the same time provides good foaming during the first cycle of wetting and squeezing.

Claims (8)

[Claims] (1) The surfactant (i) forms a liquid crystal phase upon contact with water at temperatures above the Kraft temperature and up to at least 30°C, and/or (ii) has a Kraft temperature of 20°C or above. used for cleaning soiled surfaces in the presence of water, characterized in that it consists of a first substrate and a second substrate, with said surfactant in solid form sandwiched between them. A substantially touch-dry wiping article suitable for use. (2) The article of claim 1, wherein the pure surfactant can be present in particulate form dried at 20°C. (3) The article of claim 1 or 2, wherein the surfactant forms a hexagonal or cubic liquid crystal phase upon contact with water at a temperature above its Kraft temperature and up to at least 35°C. 4. The article of claim 3, wherein the surfactant forms a liquid crystal phase at temperatures up to at least 50°C. (5) The article according to any one of claims 1 to 4, wherein the surfactant is a salt of acylisethionic acid, the acyl group contains 8 to 22 carbon atoms, and the salt is formed by a solubilizing cation. (6) Claim 5 wherein the fatty acyl group is coconut acyl.
goods. (7) The critical micelle concentration of the surfactant is at least 2mM.
An article according to any one of claims 1 to 6, which is ole/l. (8) The article of claim 7, wherein the critical micelle concentration is at least 4 mMole/l.