JPS6215378A - Cleaning of hide and leather - Google Patents

Abstract

Process for cleaning furs and leathers by treating these materials with pieces of open-celled polyurethane foam having a density of from 60 to 120 kg/m<3> which have been treated with halocarbons. A polyurethane foam suitable for this purpose is obtained by reacting mixtures of polyalkylene glycols having an equivalent weight of from 200 to 2000 and polyhydroxy compounds having an equivalent weight of from 30 to 100 with isocyanato-containing precursors of polyisocyanates and polyalkylene glycols having an equivalent weight of from 50 to 500, preferably 300. Polyurethane foams of this kind are very retentive of the solvent, which is released only gradually. This ensures very gentle cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION Garments made of real fur cannot be cleaned in organic solvents without risk of damage due to their too strong degreasing action. For this reason, most fur clothing is manufactured using the so-called Lauterungs-verf method.
ahren). According to this method, worn, dirty fur is moved in a rotating cleaning drum along with debris of hard water impregnated with a solvent. Dirt is removed from the hairs of the fur by their contact with the wood shavings, with mechanical friction helping to remove the dirt. After approximately 20 minutes of cleaning, the fur garments are transferred into vibrating barrels to remove any adhering wood debris.

The vibration time is 20-30 minutes depending on the length of the hair.

Of course, some of the cleaning material remains in the pocket or lining after vibration and must be removed by hand.

In the case of short-haired fur products, such as Belja lamb fur, it is also possible that these furs absorb too much solvent and become soft.
They are also heavily degreased and, because of the increased weight, there is a risk that they will be damaged during vibrations in the rotating drum. Another disadvantage is that the dirty hard water waste is not only no longer usable, but also poses a significant problem of disposal after one treatment. The soiled lining must be rinsed with water or an aqueous surfactant solution before this treatment. If it is heavily soiled, the lining is removed from the garment and laminated with a solvent in a separate laminating machine. Therefore, the cleaning methods described above are time consuming and involve many manual labor and removal problems.

The solution of the present invention'f! The problem is that even in the case of fur clothing, the known cleaning methods (Lλutθrungs −v
The objective was to develop a method that is equally gentle (or better), but still faster and more effective in cleaning.

In 1973, a technical book written by R. Mari and Bockelmann (Leather, Fur, Synthetic Leather and Their Cleaning (Le6er, Pe1ze, Kunstle)
On pages 29 and 30 of R und ihre Reinigung) J.
A cleaning method for somewhat soiled suede leather, developed by the company Xer), is described. Thereafter, the leather garment is packed in a polyurethane sponge (size 10
10 cm). However, there is no description regarding the properties of these sponges, such as solvent absorption, time-dependent solvent retention and abrasion resistance and compressive hardness.

The subject of the invention is fur and leather f: 60 to 120
The method for cleaning fur and leather is characterized in that it is treated with shaped bodies made of open-cellular polyurethane foam having a bulk density of "kg/m", these shaped bodies being impregnated with halogenated hydrocarbons.

Open cellular polyurethane foam is 200 to 20
A mixture of a polyalkylene glycol having an equivalent weight of 0.00 and a polyhydroxy compound having an equivalent weight of 50 to 1000 is mixed with an isocyanate group-containing preadduct of a polyisocyanate and a polyalkylene glycol having an equivalent weight of 50 to 500, preferably 500. Obtained by reaction.

The polyalkylene glycol used according to the invention is
It is prepared in a conventional manner by adding an alkylene oxide to a compound having at least two active hydrogens. Examples are ethylene glycol, 1,2-furopanediol, 1.6-hexanediol, glycerin, trimesololpropane, pentaerythritol or sorbitol. As alkylene oxide, ethylene oxide, propylene oxide or butylene oxide or mixtures thereof are used. In the case of mixtures of alkylene oxides, the polyalkylene glycols can be present as block polymers or the alkylene oxides can be added in a statistical distribution. The molecular weight of the polyalkylene glycol can vary within a wide range, and it is adjusted so that the aforementioned 200 to 2000 D equivalent weight is maintained. Polyalkylene glycols having 300 to 1000 primary hydroxyl groups 2) 50 or more moles are preferred. These polyalkylene glycols are used together with such polyhydroxyl compounds having an equivalent weight of 30 to 100. Typical examples are ethylene glycol, diethylene glycol, 1,
4-butylene glycol, glycerin and trimethylolpropane.

The incyanate component used according to the invention is a diincyanate modified with polyethylene glycol. This polyethylene glycol contains 50 to 500
．． Preferably with an equivalent weight of 30 (ml). Examples of suitable incyanates are toluylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, polyphenylpolymethylene polyisocyanate and mixtures thereof. Preferred incyanates are the isomers thereof Barrel 2,4-form te is 2,6-form,
Alternatively, toluylene diisocyanate can exist as a mixture of both these isomers. A suitable isomer mixture is about 80 t 2,4-isomer and 20 t 2,4-isomer.
6-isomer, other proportions can be used with success as well. The amount of incyanate added is
It should be matched to the remaining O component present in the reaction mixture, so that the incyanate index,
That is, the ratio of incyanato groups to hydroxyl groups present in the mixture is approximately 0.85 l/% L, 1.25, preferably 1.00 to 1.10. Other starting materials such as blowing agents and catalysts used within the scope of the invention are similar to conventional flexible urethane foams. In some cases, foam stabilizers, fire-retardant additives, and other additives are aggressively added.

Examples of blowing agents are water and fluorinated hydrocarbons, such as trichlorofluoromethane and dichlorodifluoromethane. Examples of catalysts are amine compounds such as trimethylamine, dimethylbenzylamine, N-ethylmorpholine, triethylenediamine (and its formate), dimethylpiperidine, 1,2-dimethylimidazole, dimethylaminoethanol, jetanolamine, triethanolamine , diethylaminoethanol, 1,8-diazabicyclo-(5p4po)-kundecene-7 (and their 7-enol salts) and tin compounds such as dibutyltin silacrate and tin octoate. Examples of foam stabilizers are silicones and other surfactants.

In order to produce polyurethane foams from the starting materials mentioned above, no special techniques are required which differ from the known production methods of conventional flexible urethane 7 ohms. The formation of the cells and the density of the corresponding polyurethane foams are controlled by using water and other swelling agents, such as trichlorofluoromethane or methylene chloride, which are added in the usual manner. The starting materials according to the invention are therefore:
In the correct order, the appropriate amounts are mixed together at room temperature or higher temperature, and the resulting mixture is foamed.

Polyurethane foams suitable within the scope of the invention are:
Urethane 7 ohm with a bulk density of 60 to 120 #/m3 is cut into pieces of suitably sized moldings. These molded bodies are preferably spherical or hexahedral in shape and contain 15 to 1000 ILt%, especially 100 to 200
It has a volume of lE10. These compacts, i.e. 7 ohms, are then processed with fluorinated or chlorinated hydrocarbons, such as trichlorofluoromethane, in a conventional cleaning machine with a drum internal capacity of sufficient size. It is immersed in trichloro-1,2,2-trifluoroethane, tetrachloroethane or dichloromethane.

The amount of these solvents is about 100 to 300% based on the polycrethane sponge. The article to be cleaned is then added to the foam impregnated in this way and the article is rotated in a cleaning machine for a sufficient period of time with 7 ohms. Filling rate (4 per item)
I=drum volume) is adjusted depending on the type of article to be cleaned. short-haired fur and semi-smoked fur (
(e.g. European kinks, raccoons) and in the case of furs with a suede-backed or natsupa leather finish.
This filling ratio is approximately 1:20 to 1:30 for thick coats, whole smoked coats and long coats (e.g. Mongolian lambs,
Approximately 1 = 50 in the case of Canada 7 foxes, high-class foxes)
The time is 1:80.

To enhance the cleaning effect, add a strong sponge to the article, and to improve the damage of the article, add a cleaning reinforcing agent, an additive, a brightening agent, a hydrophobic and an oleophobic agent to the solvent. Adjuvants such as insecticides, insect repellents and fatliquors and conditioning agents are added. The article must not absorb more than 5 ats of its inherent weight during the cleaning period. The cleaning time during which the article to be treated is moved in the rotating drum depends on the degree of soiling and the type of material to be cleaned, but experience has shown it to be about 10 to 20 minutes. The article is then centrifuged and the separated cleaning liquid is pumped into a distillation vessel or storage tank. This is followed by drying, during which the solvent is recovered at 15 to 45° C. (measured in the gas chamber at the drum outlet). After completion of drying, the articles and sponges are removed from the drum in a dry and odor-free condition. Before drying the article, it is preferable to suck the sponge from the drum into the container with a special device. Dirty sponges are sometimes cleaned in the solvent bath of a cleaning machine depending on the degree of soiling, so they can be used again.

During this cleaning operation, the sponge having the qualities according to the invention K, even at different degrees of compression, releases only a portion of the absorbed solvent from the article to be cleaned. This amount of solvent is sufficient to dissolve the soil in the article. Soil removal occurs by friction of the article to be cleaned against the surface of the solvent-containing sponge, which absorbs the dissolved soil. By adding surfactants, fatliquors, etc.
Cleaning damage, leather flexibility and fur hair appearance are improved and tendrils.

When cleaning in a drum, fur products are strongly degreased and can be damaged by the special finishing process, even with the addition of fatliquors, when processed in solvent baths. , substances with special affinity for solvents must be added. Such substances ie act as solvent buffers. The polyurethane foam used according to the invention with a defined bulk density does not impart less than 20 inches of absorbed solvent to the article to be coated, thereby increasing the strength of sensitive textile and leather materials. Damage due to over-extraction is avoided.

The cleaning method according to the invention is suitable not only for leather and fur clothing, but also for other types of textile products that are damaged during treatment in solvent baths. This includes, for example, clothing made of soft PVO whose plasticizers are significantly extracted by the solvents used in the cleaning of textiles, making the fabric hard, brittle and cracked. Additionally, this method is overconfident due to degreasing during finishing of fur hides.

Example 1 (comparative example) Glycerin/propylene oxide/ethylene oxide adduct compound (average molecular weight 5500, hydroxyl value 47,
Proportion of primary hydroxyl groups (20 mol%) 100 parts by weight, 2.5 parts by weight of water, 0.8 parts by weight of nine foam stabilizer based on polysiloxane, 33% by weight of triethylenediamine and 6% by weight of dipropylene glycol. A mixture consisting of 0
．． 36 parts by weight of tin octoate (I[lo,ts) and 35 parts by weight of toluylene diisocyanate were intimately mixed and foamed into paper.

A typical soft elastic 7 ohm material with a bulk density of 59 kg 7 m'' is thereby obtained.

Example 2 100 parts by weight of glycerin-propylene oxide-ethylene oxide adduct with a proportion of primary hydroxyl groups of 60 mol% and an average equivalent weight of 450 (hydroxyl number = 125), 8 parts by weight of 1,4-butane-diol, water 0.5 parts by weight, 10 parts by weight of trichlorofluoromethane, foam stabilizer [Goldschmidt A
Tegostab B 41 manufactured by G)
15) 0.5 parts by weight of a 33% solution of triethylenediamine in diglobylene glycol and 0.6 parts by weight of a 33% solution of triethylenediamine in diglobylene glycol and 0.05 parts by weight of dibutylene dilaurate) 80720 72% by weight average molecular weight 600 with 28% by weight of polyethylene glycol and foamed in a pre-prepared paper mold.9. After foaming, the 7 Ohm was cured in the open at 70°C for 15 minutes, cooled and the 97 Ohm was cut into suitable strips. 90 kg 7m'
An open microporous soft elastic foam with bulk density is obtained.

Other 7 ohms according to the invention with different compression hardnesses can be manufactured according to Examples 3 to 6 below. In this case, the procedure was as in Example 2. The nine formulations summarized in Table 1 below are based on the following ingredients: A=TercarolO'I
Product name of a 200 [Manufacturer: Carbohim
chim, B-y 540 T&]01
Branched polyol with a value of 75, B = 1.4-butanediol C = glycerin D = water Z = 33% solution of dipropylene glycol triethylene diamine? = Tegostab' B 4115
[Manufacturer: Goldschmidt Co., Ltd. (Golds-ni =)
lychlorofluoromethane I, =) lylene diisocyanate 80/20 72% by weight and polyethylene glycol 28 with an average molecular weight of 600
Reaction products with weight % Table 1 B 11.5 -
- -c -7,77
,711jDO,50,50,5
0,5I O,60,60,60,
6F 0.5 05
05 generation 5G --0,1
0,IHO,050,05-- K 10 10
10 10 Table 2 below shows the "deformation pressure" for various heights of the sponge according to each recipe,
It shows that deformation values of 10 to 50% can be obtained from compressive hardness measurements. Depending on the type of material to be cleaned, a corresponding foam hardness is selected, the sponge having to be deformed by up to 50% in order to achieve a cleaning effect. In that case, the progressively increasing deformation pressure from 10% to 50% is
It is advantageous in that, on the one hand, the precision or leaning effect is clouded in the case of friction and slight deformations, and, on the other hand, complete total compression (Zusgamme), which leads to an outflow of the solvent from the sponge;
The burden force of the sponge (Br
There is the above-mentioned advantage that laslbarkeit) becomes clear.

In contrast to the foam according to the invention, the conventional polyurethane flexible foam according to Example 1 has little increase in deformation pressure, i.e. *in the load range of 10% deformation where the cleaning action can be initiated by vibrational forces. Deformations of as much as &C50% are also possible, which would promote the outflow of solvent from the sponge and result in damage to the article to be cleaned.

Table 2: 1 at the following deformation rates? /a (D Engineering 155577)
10% 25% 50% 1 3, IS,
5 4.2 (comparison 7 ohms) 2 1.13 2.
7 4.75 1.
6 2,4 4.54
3.6 5,7 11.25
4.6 6.5 11
．． 06 4.8 7,7
14.4 The special capabilities of polyurethane foams with the bulk densities defined in this invention for cleaning fur are illustrated in the following tests. Three different materials were used as solvents, trichlorofluoromethane (Figure 1);
1,1.2-)lichloro-1,2,2-)lifluoroethane (Figure 2) and tetrachloroethane (Figure 5)K
Tested for their affinity for: 1. Cleaning method for fur cleaning (Lau
Sawdust of the quality as used for terungsverfahre V5, 2 typical polyurethane soft 7 ohm produced according to example 1 (comparative example), 5 open cell type produced according to example 2 (7 ohm according to the invention) Polyurethane soft 7 ohm.

The distribution of the solvent between these support substances and the fur is determined by
) was tested in the following manner: the test material was dried by 1/2 in a drying cabinet at 20°C and 1/2 by drying in an oven.
Cool for an hour.

Z Place a pouch containing a piece of Belja lamb skin with dimensions 5X5C11 and 10 steel balls into a screwable Riwatestou cup 5 5 X 2,5 X
f, a sponge with a side length of 5a++ (volume 18.
75crl+l) i or 8c1 of sawdust in a cotton pouch
Impregnate 1s with oil-wetting solvent.

Melon Let the solvent flow for 10 seconds and weigh the sachet containing the sponge or sawdust. For sawdust, dry and moisten and subtract the weight of nine sachets later.

& 10 types of sponges separated according to quality and the sachets are rotated for 10 minutes in a Linitest together with the fur piece and the steel balls in the sachets.

& After 10 minutes, individually remove and weigh the sponge or sawdust sachets and fur pieces.

7. Repeat the test with a treatment time of 20 to 50 minutes.

The numerical values obtained at this time are reproduced in the charts of FIGS. 1-3. The curves S1 and B1 are respectively Example 1
The residual amount of solvent determined in the case of the support material I'UR-form (Sl) according to Example 2 FUR-7 Ohm (S, ) and sawdust (83), expressed as a percentage. Curves Pl e PR and B3 show the corresponding residual amounts in the fur. The closer the corresponding pair of curves of the support material and the fur overlap each other, the more solvent is being exchanged. Thus, in the case of tetrachloroethane there is an undesirable solvent compensation (
Lδsemitte1. auagleich) has occurred, that is, the curves S and P cross each other before 50 minutes have elapsed (see FIG. 3).

In contrast, in the presence of 7 ohms of the present invention according to Example 2, the fur is at most 10% of the total amount of solvent (see Figures 1 and 3) and tetrachloroethane, both in the case of fluorinated hydrocarbons. In most cases, it absorbs only 20% at most (see Figure 3). All three drawings clearly show that the distance between the pair of curves S and Pl is the largest. The amount of solvent exchanged between the polyurethane foam and fur according to Example 1 is intermediate between the values for 7 ohms according to the invention and for sawdust, giving only a small amount of solvent. The pair of curves S and P, in all three diagrams, shows that the fur absorbs more than 20% of the total amount of solvent in the presence of the polyurethane foam according to Example 1. These tests show that polyurethane foams with relatively high bulk densities, such as those used by the present invention, do not impart most of the absorbed solvent to the fur pieces, whereas typical soft foam sponges (according to Example 1) This shows that the amount of solvent retained in sawdust and sawdust is significantly lower.

Two tested 7-ohm quality sponges were tested for abrasion resistance under practical conditions as well as on a laboratory scale. In the practical test, a cube-shaped sponge with -side 50 was cleaned 12 times using an Fff type cleaning machine. Cleaning time was 12 minutes per treatment. In addition to using Fff115 for 10 sponges of 1 quality, the foam according to Example 2 was rocked for 5 hours together with a sachet containing 10 steel balls.The wear resistance of the foam according to Example 2 was as follows. EXAMPLE OF USE OF ROLLING IN FUR CLEANING In a cleaning machine with a drum internal capacity of about 100 OA', a sponge of diameter 5α manufactured according to Example 2 1
5#! After closing the door of the filled container, the solvent was injected into the drum through the nozzle. The weight of the absorbed solvent is about twice the weight of the sponge. Thereafter, the container door was reopened and fur clothing (4oIcg) was charged into the drum from the connected nine drum suction. The filling factor (kg of clothing: 1 drum volume) was 1:25. Cleaning time was 10 to 20 minutes. The fur garment was then centrifuged and the separated cleaning bath was sent to a distillation vessel or storage tank.

This is followed by drying, during which 15 to 45°C
Collect the solvent at a temperature of (measured in the gas chamber at the drum outlet). At the end of drying, the fur garments and sponges were removed from the drum in a dry and odor-free condition.

A diameter 5C manufactured according to Example 2 in a cleaning machine with a drum internal volume of approx. 5001! 1 sponge 8
kg was filled. Next, after closing the container door, inject the solvent into the drum through the nozzle. The weight of solvent absorbed was on the order of about twice the weight of the sponge. Thereafter, the door of the container was opened again and the clothes made of PVC-synthetic leather were charged into the drum through the connected nine-drum suction section. The filling factor (kg clothing: 1 drum capacity) is approximately 1
:25. To enhance the cleaning effect,
A stiff sponge was added along with the article to be treated. The workpiece loses 30% of its inherent weight during the cleaning period.
Do not absorb more than %. It was otherwise operated similarly to the previous example for fur cleaning.

[Brief explanation of drawings]

Figures 1 to 3 are charts showing the relationship between overlapping IJ-coatings and their affinity for solvents in examples according to the invention and comparative examples.

Claims (1)

[Claims] 1. A method for cleaning textiles, fur and leather, and a method for degreasing fur during finishing,
These materials are treated with molded bodies made of open cellular polyurethane foam having a bulk density of 60 to 120 kg/m^3, characterized in that these molded bodies are impregnated with halogenated hydrocarbons. The above method. A mixture of a polyalkylene glycol having an equivalent weight of 2,200 to 2,000 and a polyhydroxy compound having an equivalent weight of 30 to 100 is obtained from a polyisocyanate and a polyalkylene glycol having an equivalent weight of 50 to 500, preferably 300. 2. The method according to claim 1, which uses a molded article made of polyurethane foam obtained by reacting with the isocyanato group-containing intermediate product obtained. 3. The method according to claim 1, in which surfactants, fatliquors or other auxiliaries are additionally used.