US3189403A - Tanning with a hemiacetal and resorcinol or pyrogallol solution - Google Patents
Tanning with a hemiacetal and resorcinol or pyrogallol solution Download PDFInfo
- Publication number
- US3189403A US3189403A US289144A US28914463A US3189403A US 3189403 A US3189403 A US 3189403A US 289144 A US289144 A US 289144A US 28914463 A US28914463 A US 28914463A US 3189403 A US3189403 A US 3189403A
- Authority
- US
- United States
- Prior art keywords
- tanning
- resorcinol
- integer
- tannage
- aldocryl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- GHMLBKRAJCXXBS-UHFFFAOYSA-N resorcinol Chemical compound OC1=CC=CC(O)=C1 GHMLBKRAJCXXBS-UHFFFAOYSA-N 0.000 title description 34
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 title description 16
- 150000002373 hemiacetals Chemical class 0.000 title description 9
- 229940079877 pyrogallol Drugs 0.000 title description 8
- 238000000034 method Methods 0.000 claims description 23
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 239000010985 leather Substances 0.000 description 17
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 16
- 229910052739 hydrogen Inorganic materials 0.000 description 14
- 239000001257 hydrogen Substances 0.000 description 14
- 239000000243 solution Substances 0.000 description 12
- 239000003795 chemical substances by application Substances 0.000 description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 7
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical compound OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 238000011065 in-situ storage Methods 0.000 description 3
- 150000002989 phenols Chemical class 0.000 description 3
- 235000013311 vegetables Nutrition 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000007859 condensation product Substances 0.000 description 1
- SLGWESQGEUXWJQ-UHFFFAOYSA-N formaldehyde;phenol Chemical class O=C.OC1=CC=CC=C1 SLGWESQGEUXWJQ-UHFFFAOYSA-N 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- -1 resorcinol Chemical class 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000001632 sodium acetate Substances 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 235000018553 tannin Nutrition 0.000 description 1
- 229920001864 tannin Polymers 0.000 description 1
- 239000001648 tannin Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C14—SKINS; HIDES; PELTS; LEATHER
- C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
- C14C3/00—Tanning; Compositions for tanning
- C14C3/02—Chemical tanning
- C14C3/08—Chemical tanning by organic agents
Definitions
- This invention relates to the tanning of skins. More particularly, this invention relates to an in situ polymeric tannage employing Aldocryl and a phenol.
- skins are meant all animal skins, such as cowhide, horsehide, calfskin, goatskin, sheepskin, pigskin, and fur skins, which are tanned commercially.
- Aldocryl is the trade name for a hydroxy-containing hemi-acetal obtained as a condensation product of acrolein and formaldehyde. It is not a single chemical, but is a mixture of compounds represented by the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n. is an integer of at least 2.
- Hemi-acetals are not expected to be effective tanning agents, but Aldocryl tannage produces a firm, fiat white leather.
- the product has a low shrink temperature (T 81-83 C.). This shrink temperature is typical of an organic tannage, being comparable to that of a vegetable (natural organic) tanned leather or of the best synthetic tannin, such as a sulfonated phenol-formaldehyde polymer.
- phenols such as resorcinol
- phenols have no tanning ability per se. When employed as the sole agent in a tanning system they are only weakly bonded to the skin and are readily removed by washing the skin.
- phenolaldehyde tannages give products which are unstable to light and will darken with aging even in the absence of light.
- skins are tanned by a process comprising impregnating the skins with a buffered aqueous solution at pH in the range of about 4.0 to 5.0 containing Aldocryl and a phenol selected from resorcinol and pyrogallol and adjusting the pH of the solution during the tanning process to a pH of about 7.5-8.5.
- the tannage gives an inherently mellow leather. This is presumably because the tanning molecules formed in situ are relatively low in molecular weight.
- the reaction between the Aldocryl and resorcinol is interrupted and terminated by reaction with the protein.
- the present tannage appears to be more eifective than a vegetable tannage in producing a full leather.
- the leather has high thermal stability. Domestic sheep-1 skin can be tanned to give a leather which does not shrink in boiling water in 5 minutes. This degree of tannage is not necessary, but is cited to illustrate the potential of the new combination tannage.
- the high heat resistance obtainable in Aldocryl-resorcinol tanned leather allows the tanned skin to be fat-liquored and finished in normal production manner, whereas vegetable tanned skins require special handling.
- Tannages were performed with various ratios of Aldocryl and phenol, and over a range of total amounts of tanning agent added, and the results compared with aldocryl tannages conducted for control purposes.
- a pickled sheepskin (usually a 100 gm. sample) was placed in a container with 100% water float, 10% by Weight of a 10% solution .of sodium sulfate, and 3%" sodium acetate, all based on pickled weight ofthe skin, and turned for one-half hour at 90 F. to depickle the skin.
- the pH of the solution is about 4.7.
- the tanning agent was added and turning continued one hour.
- the pH of the solution typically about 4.5, was adjusted to pH 7.8-8.0 by adding sodium bicarbonate in 3 feeds. The churn was turned for two hours more with the system at 90-95" F.
- the skin was removed, a sample taken for shrink temperature measurements, the skin was washed for one-half hour in running water, horsed to drain, and acidified with 1% sulfuric acid to about pH 4.04.5 in preparation for fatliquoring and finishing.
- Table 1 are summarized data obtained following the typical procedure and varying the tanning agents.
- Some of the sets of data are selected from two or more tannages conducted under similar conditions to give leather with an identical shrink temperature. Duplicates have been omitted from the table for purposes of clarity in analyzing the data.
- shrink temperature is 88-91 C.
- Example 19 The depickling and tannage followed the typical procedure and varied from Example in that the tanning agents added to a 100 gm. sample of sheepskin were 5.12 gms. Aldocryl and 2.5 gms. pyrogallol, a total of 7.62%, and a 3 to 1 molar ratio of Aldocryl to phenol.
- Example This process was identical with Example 15, except that catechol was substituted for resorcinol.
- the shrink temperature is 83 C. This is the shrink temperatureof an Aldocryl tannage. There is no evidence of a combination'tannage.
- shrink temperature of leather is not per se indicative of the overall properties of a leather, it is generally accepted as an important criteria of degree tannage.
- resorcinol is the preferred phenol
- pyrogallol may also be used in the new in situ tannage. Catechol appears to be unreactive.
- the Aldocryl-resorcinol tannage is particularly effective in providing perspiration resistance to the leather product, as determined by the standard test in Which the leather sample was soaked for 2 hours in a standard, synthetic perspiration solution and then heated in a humid atmosphere at 70 C. for 48 hours.
- Leather products, both from domestic sheepskin and from cabretta skins, tanned with resorcinol and Aldocryl remained flat and flexible and changed very little in shape and area. Tests performed on leather which had been stored for six months or longer indicate that this property may be retained indefinitely.
- a tannin-g process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and a phenol selected from the group consisting of resorcinol and pyrogallol and adjusting the pH of the solution during the tanning process to a pH in the range of about 7.5 to 8.5.
- a tanning process comprising impregnating skins with a buttered aqueous solution at a pH in the range of about 4.0 to 5.0 containing a hcmi-acetal of the formula A OR wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of l to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is aninteger of at least 2 and a phenol selected from the group consisting of resorcinol and pyrogal'lol, said hemi-acetal and said phenol being present in a molar ratio of about from 1-1 to 3-1 hemi-acetal to phenol, and adjusting the pH of the solution during the tanning process to a pH in the range of about 7.5 to 8.5.
- a tanning process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing in the range of about 13.5 to 18%, based on weight of the skin, of a 1 to 1 molar ratio of a hemi-acetal ofthe formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7.5 to 8.5.
- a tanning process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing at least about 5%, based on weight of the skin, of a 2 to 1 molar ratio of a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1'to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7.5 to 8.5.
- a tanning process comprising impregnating skins with a bufiered aqueous solution at a pH in the range of about 4.0 to 5.0 containing about from 5 to 17%, based on weight of skin, of a 3 to 1 molar ratio of a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and a-lkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7 .5 to 8.5.
- a tanning process comprising impregnating skins with a buttered aqueous solution at a pH in the range of about 4.0 to 5.0 containing about 5%, based on weight of skin, of a 3 to 1 molar ratio of a hemi-acetalot the formula (JR K 2i 2]a )yln wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8,
- y is an integer of 1 to 5
- n is an integer of at least 2 and a phenol selected from the group consisting of resor- 6 References Cited by the Examiner UNITED STATES PATENTS 2,321,451 6/43 Bauer 26042 5 2,840,445 6/58 Severn.
Description
United States Patent Ofi ice 3,189,403 Patented June 15, 1965 3,189,403 TANNING WKTH A HEMHACETAL AND RESOR- (IHJGL R PYROGALLUL SOLUTION Wallace Windus, Meadowbrook, and Mary V. Hannigan,
Lafayette Hill, Pa, assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed June 19, 1963, Ser. No. 289,144
12 Claims. (Cl. 8-94.24) (Granted under Title 35, US. Code (1.952), sec. 256) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.
This invention relates to the tanning of skins. More particularly, this invention relates to an in situ polymeric tannage employing Aldocryl and a phenol.
By skins are meant all animal skins, such as cowhide, horsehide, calfskin, goatskin, sheepskin, pigskin, and fur skins, which are tanned commercially.
Aldocryl is the trade name for a hydroxy-containing hemi-acetal obtained as a condensation product of acrolein and formaldehyde. It is not a single chemical, but is a mixture of compounds represented by the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n. is an integer of at least 2.
Hemi-acetals are not expected to be effective tanning agents, but Aldocryl tannage produces a firm, fiat white leather. In addition to lack of fullness the product has a low shrink temperature (T 81-83 C.). This shrink temperature is typical of an organic tannage, being comparable to that of a vegetable (natural organic) tanned leather or of the best synthetic tannin, such as a sulfonated phenol-formaldehyde polymer.
Many phenols, such as resorcinol, have no tanning ability per se. When employed as the sole agent in a tanning system they are only weakly bonded to the skin and are readily removed by washing the skin. Combination tannages with phenols, such as phenols and aldehydes, are not generally applicable. Moreover, phenolaldehyde tannages give products which are unstable to light and will darken with aging even in the absence of light.
We have discovered, however, that the combination tannage of Aldocryl and a phenol such as resorcinol or pyrogallol gives a leather product from a domestic sheepskin which is full, mellow, does not darken in light, has an exceptionally high shrink temperature, and is resistant to shrinkage by perspiration.
According to the present invention skins are tanned by a process comprising impregnating the skins with a buffered aqueous solution at pH in the range of about 4.0 to 5.0 containing Aldocryl and a phenol selected from resorcinol and pyrogallol and adjusting the pH of the solution during the tanning process to a pH of about 7.5-8.5.
The tannage gives an inherently mellow leather. This is presumably because the tanning molecules formed in situ are relatively low in molecular weight. The reaction between the Aldocryl and resorcinol is interrupted and terminated by reaction with the protein.
For any given amount of tanning material, the present tannage appears to be more eifective than a vegetable tannage in producing a full leather.
The leather has high thermal stability. Domestic sheep-1 skin can be tanned to give a leather which does not shrink in boiling water in 5 minutes. This degree of tannage is not necessary, but is cited to illustrate the potential of the new combination tannage. The high heat resistance obtainable in Aldocryl-resorcinol tanned leather allows the tanned skin to be fat-liquored and finished in normal production manner, whereas vegetable tanned skins require special handling.
Tannages were performed with various ratios of Aldocryl and phenol, and over a range of total amounts of tanning agent added, and the results compared with aldocryl tannages conducted for control purposes.
A typical procedure is as follows:
A pickled sheepskin (usually a 100 gm. sample) was placed in a container with 100% water float, 10% by Weight of a 10% solution .of sodium sulfate, and 3%" sodium acetate, all based on pickled weight ofthe skin, and turned for one-half hour at 90 F. to depickle the skin. At this time the pH of the solution is about 4.7. The tanning agent was added and turning continued one hour. The pH of the solution, typically about 4.5, was adjusted to pH 7.8-8.0 by adding sodium bicarbonate in 3 feeds. The churn was turned for two hours more with the system at 90-95" F.
After a total of 4 hours in the tanning solution, the skin was removed, a sample taken for shrink temperature measurements, the skin was washed for one-half hour in running water, horsed to drain, and acidified with 1% sulfuric acid to about pH 4.04.5 in preparation for fatliquoring and finishing.
In Table 1 are summarized data obtained following the typical procedure and varying the tanning agents.
Some of the sets of data are selected from two or more tannages conducted under similar conditions to give leather with an identical shrink temperature. Duplicates have been omitted from the table for purposes of clarity in analyzing the data. t
TABLE I.TANNAGE OF DOMESTIC SHEEPSKIN Tannage 1 Example Ratio ,3 No. A-R 2 C.
Aldocryl, Resore'mol, Total,
percent percent percent 5 5 82 10 10 83 2O 20 82 2 2. 5 4. 5 1-1 -82 6 7. 5 13. 5 1-1 85-86 6. 4 8. 0 14. 4 1-1 88 8 10.0 18.0 1-1 88 12 10 22. (l 1. 5-1 89 3. 04 1. 9 4. 94 2*1 83 6. 24 3. 8 10. 04 2-1 87 12. 0 7. 5 19. 5 2-1 97 5. 0 2. 5 7. 5 2. 5-1 94 10. 0 5. 0 15. 0 2. 5-1 92 3.6 1. 5 5. 1 3-l 92 6. 0 2. 5 8. 5 3-1 94-96 7. 2 3. 0 10. 2 3-1 97 12. 0 5. 0 l7. 0 3-1 100 12. 0 2. 5 17. 5 6-]. 9294 1 Based on wet weight; of sheepskin.
2 Ratio of moles Aldocryl to moles resorcinol.
3 Shrink temperature at completion of tanning. several degrees after acidification.
4 5 minutes boil.
'1 is usually increased shrink temperature is 88-91 C.
Example 19 The depickling and tannage followed the typical procedure and varied from Example in that the tanning agents added to a 100 gm. sample of sheepskin were 5.12 gms. Aldocryl and 2.5 gms. pyrogallol, a total of 7.62%, and a 3 to 1 molar ratio of Aldocryl to phenol. The In general, the leath er had an appearance similar to that of Examples 14 and 15.
Example This process was identical with Example 15, except that catechol Was substituted for resorcinol. The shrink temperature is 83 C. This is the shrink temperatureof an Aldocryl tannage. There is no evidence of a combination'tannage.
Although the shrink temperature of leather is not per se indicative of the overall properties of a leather, it is generally accepted as an important criteria of degree tannage.
The. examples show that for all Aldocryl-resorcinol tannages, from a 11 molar ratio to at least a 3-1 molar ratio combination, the shrink temperature tends to increase with increase in amount of tanning agent employed. 5
This is in contrast to tannage with Aldocryl alone, where, as illustrated in Examples 1 3, there is no improvement in shrink temperature. The optimum combination is indicated to be in the range of about 2.51 to 3-1. This tannage achieves a significant increase in shrink temperature with a small amount of tanning agent. With a 3-1 molar ratio of Aldocryl" to resorcinol a shrink temperature of over 90 C. was obtained with a total of 5% tanning agent. The effectiveness of this tannage makes it possible to vary the process to obtain the desired amount of fullness and mellowness and to have high thermal stability in all the leather products.
Although resorcinol is the preferred phenol, pyrogallol may also be used in the new in situ tannage. Catechol appears to be unreactive.
The Aldocryl-resorcinol tannage is particularly effective in providing perspiration resistance to the leather product, as determined by the standard test in Which the leather sample was soaked for 2 hours in a standard, synthetic perspiration solution and then heated in a humid atmosphere at 70 C. for 48 hours. Leather products, both from domestic sheepskin and from cabretta skins, tanned with resorcinol and Aldocryl remained flat and flexible and changed very little in shape and area. Tests performed on leather which had been stored for six months or longer indicate that this property may be retained indefinitely.
An unusual characteristic of the leather products of this tannage is the reaction to light. instead of darkening, as is typical of a tannage in which a phenol is employed, the exposed samples did not become darker, but remained unchanged or became slightly lighter in color.
We claim: 7
1. A tannin-g process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and a phenol selected from the group consisting of resorcinol and pyrogallol and adjusting the pH of the solution during the tanning process to a pH in the range of about 7.5 to 8.5.
2. The process of claim 1 in which the phenol is resorcinol.
3. The process of claim 1 in which the phenol is pyrogallol.
4. A tanning process comprising impregnating skins with a buttered aqueous solution at a pH in the range of about 4.0 to 5.0 containing a hcmi-acetal of the formula A OR wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of l to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is aninteger of at least 2 and a phenol selected from the group consisting of resorcinol and pyrogal'lol, said hemi-acetal and said phenol being present in a molar ratio of about from 1-1 to 3-1 hemi-acetal to phenol, and adjusting the pH of the solution during the tanning process to a pH in the range of about 7.5 to 8.5.
5. The process of claim 4 in which the phenol is resorcinol.
6. The process of claim 4 in which the phenol is pyrogallol.
7. A tanning process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing in the range of about 13.5 to 18%, based on weight of the skin, of a 1 to 1 molar ratio of a hemi-acetal ofthe formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7.5 to 8.5.
8. A tanning process comprising impregnating skins with a buffered aqueous solution at a pH in the range of about 4.0 to 5.0 containing at least about 5%, based on weight of the skin, of a 2 to 1 molar ratio of a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1'to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7.5 to 8.5.
9. A tanning process comprising impregnating skins with a bufiered aqueous solution at a pH in the range of about 4.0 to 5.0 containing about from 5 to 17%, based on weight of skin, of a 3 to 1 molar ratio of a hemi-acetal of the formula wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and a-lkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8, y is an integer of 1 to 5, and n is an integer of at least 2 and resorcinol and adjusting the pH of the solution during the tanning process to a pH in the range of 7 .5 to 8.5.
10. A tanning process comprising impregnating skins with a buttered aqueous solution at a pH in the range of about 4.0 to 5.0 containing about 5%, based on weight of skin, of a 3 to 1 molar ratio of a hemi-acetalot the formula (JR K 2i 2]a )yln wherein at least one R is hydrogen and the remaining Rs are members of the group consisting of hydrogen and alkyl radicals, x is an integer of 1 to 5, a is an integer of 1 to 8,
y is an integer of 1 to 5, and. n is an integer of at least 2 and a phenol selected from the group consisting of resor- 6 References Cited by the Examiner UNITED STATES PATENTS 2,321,451 6/43 Bauer 26042 5 2,840,445 6/58 Severn.
3,080,281 3/63 Fisher 894.33 XR NCRMAN G. TORCHIN, Primary Examiner.
Claims (1)
1. A TANNING PROCESS COMPRISING IMPREGNATING SKINS WITH A BUFFERED AQUEOUS SOLUTION AT A PH IN THE RANGE OF ABOUT 4.0 TO 5.0 CONTAINING AHEMI-ACETAL OF THE FORMULA
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US289144A US3189403A (en) | 1963-06-19 | 1963-06-19 | Tanning with a hemiacetal and resorcinol or pyrogallol solution |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US289144A US3189403A (en) | 1963-06-19 | 1963-06-19 | Tanning with a hemiacetal and resorcinol or pyrogallol solution |
Publications (1)
Publication Number | Publication Date |
---|---|
US3189403A true US3189403A (en) | 1965-06-15 |
Family
ID=23110235
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US289144A Expired - Lifetime US3189403A (en) | 1963-06-19 | 1963-06-19 | Tanning with a hemiacetal and resorcinol or pyrogallol solution |
Country Status (1)
Country | Link |
---|---|
US (1) | US3189403A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3617186A (en) * | 1970-01-08 | 1971-11-02 | Us Agriculture | Tanning with tris(hydroxymethyl)nitromethane and a polyhydric phenol |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2321451A (en) * | 1938-07-25 | 1943-06-08 | Gen Aniline & Film Corp | Water-soluble condensation product |
US2840445A (en) * | 1954-06-09 | 1958-06-24 | Koppers Co Inc | Process of retaning mineral tanned leather with resorcinol-formaldehyde |
US3080281A (en) * | 1959-07-24 | 1963-03-05 | Shell Oil Co | Hydroxy-containing hemi-acetals, their preparation and use |
-
1963
- 1963-06-19 US US289144A patent/US3189403A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2321451A (en) * | 1938-07-25 | 1943-06-08 | Gen Aniline & Film Corp | Water-soluble condensation product |
US2840445A (en) * | 1954-06-09 | 1958-06-24 | Koppers Co Inc | Process of retaning mineral tanned leather with resorcinol-formaldehyde |
US3080281A (en) * | 1959-07-24 | 1963-03-05 | Shell Oil Co | Hydroxy-containing hemi-acetals, their preparation and use |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3617186A (en) * | 1970-01-08 | 1971-11-02 | Us Agriculture | Tanning with tris(hydroxymethyl)nitromethane and a polyhydric phenol |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2941859A (en) | Tanning with glutaraldehyde | |
WO2013093098A1 (en) | Leather manufacturing process using a soluble oxidized starch-derived polysaccharide and compositions containing it. | |
US2552129A (en) | Tanning with a free aldehyde and a free polyhydric phenol mixture in a molecular ratio of at least 2 to 1 | |
DE102005008034A1 (en) | Acid group-containing condensation products | |
US3104151A (en) | Combination tannage with tetrakis (hydroxy-methyl) phosphonium chloride and a phenol | |
US3189403A (en) | Tanning with a hemiacetal and resorcinol or pyrogallol solution | |
US2516283A (en) | Resin impregnation of a dialdehyde tanned hide | |
US3888625A (en) | Method of chrome-retanning leather | |
WO2000073513A1 (en) | Leather tanning | |
KR101540134B1 (en) | Method for producing leather | |
US2992879A (en) | Tanning with tetrakis (hydroxymethyl) phosphonium chloride and phenol | |
US2809088A (en) | Process of retanning leather with a condensation product of sulfones of monohydric phenols, non-aromatic amines and formaldehyde | |
US3106541A (en) | Cationic aminoplast resins which are formaldehyde dicyandiamide condensates and process for preparing same | |
US3442859A (en) | Condensates of sulfonated formaldehyde-mixed phenols condensates with formaldehyde and a phenol | |
US3934975A (en) | Leather treating process | |
WO2000079011A1 (en) | Leather tanning | |
US2890095A (en) | Process of retanning leather with condensation products of phenols, amines, and formaldehyde | |
US3254937A (en) | Dry chrome pretannage and dry syntan or vegetable tannage | |
US2470450A (en) | Tanning with free formaldehyde and melamine simultaneously | |
US2512709A (en) | Chloral-dihydric phenol polymers | |
US2880053A (en) | Process of tanning hides with polymethoxyaldehyde compounds and optionally vegetable tanning | |
US2552130A (en) | Tanning proteinaceous fibers with a mixture of an aldehyde and a polyhydric phenol in a molecular ratio of at least 2 to 1 | |
US2009255A (en) | Method of tanning leather and the leather produced by said method | |
US2701749A (en) | Process of tanning with borated methylol phenols | |
US3029212A (en) | Synthetic tanning agent and process for preparing same |