AU736810B2 - Treatments for protecting animal hair against sunlight damage during growth - Google Patents

Description

2 TREATMENTS FOR PROTECTING ANIMAL HAIR AGAINST SUNLIGHT DAMAGE DURING

GROWTH

The invention relates to a method of treating animal hair, especially sheep wool, so that the damage to the wool caused by subsequent exposure to sunlight is reduced, to prepared reagent mixtures which will prevent such damage, and to improved commercial animal hair and wool products derived therefrom.

Commercial animal hair and wool is damaged by exposure to sunlight during growth. The damage is mainly confined to the outermost tips of fibres on the back of the animal, because the sunlight cannot penetrate to the base of fibres in compact fleeces, especially those from Merino sheep. The damage is apparent as deterioration in the softness of wool tips on the back of the sheep. When wool is scoured the damage is apparent as deterioration in brightness and increase in yellowness of the fibre, especially at the tips of the staples. The damaged tips require more severe conditions during scouring, leading to greater entanglement. Much of the damaged tip is lost from the wool 15 during growth and textile processing. Wool from hotter more northerly parts of Australia, which also have higher amounts of ultraviolet radiation, lose more fibre length during processing to top stage and produce more short fibre waste than equivalent wool grown in a less severe environment.

Dyes are taken up to different extents by wool at the degraded tip and the undamaged base of the fibres, causing an uneven colour in dyed fabrics and a variable depth of colour between fabrics made S 20 from wools with different amounts of sunlight damage. A major factor and expense in wool dyeing is the use of special additives to minimise this variability. Dust generated from the degraded parts of the fibre during processing is a health hazard, and is probably formed in greater amount from wool with a greater amount of weather damage. The changes in appearance and colour of the wool tips are also apparent when the wool is processed in the form of sheepskins or lambskins.

These effects are only evident when sheep are run outdoors in sunshine, and can be overcome by keeping the sheep indoors or by using coats on the sheep. These solutions are expensive and often impracticable.

Accordingly, it is an object of the present invention to overcome, or at least alleviate, one or more of the difficulties or deficiencies related to the prior art.

We have now found that a single application to the wool on the sheep of certain sunscreen compositions, which may also contain antioxidants, causes a significant reduction for a whole growing season in the damage caused to wool by sunlight. Multiple applications at several times during the growing season have been found to further reduce the damage caused to wool by sunlight.

It is preferred that the compositions be applied to sheep within three months of the previous fibre harvest or shearing. For convenience in animal husbandry the treatments may be applied to sheep within the first few days after shearing, but the treatments are more effective when applied at least 2 weeks after shearing.

The sunscreen composition can be applied to the wool by a range of methods known for use in topical treatment of sheep. These include spraying with a hand-held single jet or an assembly of jets up to 30 cm wide. Pumping rates from 20 to 100 ml per second have been found satisfactory. We have found that with some sunscreen compositions it is desirable to either spray the material onto a roller covered with fibre before applying it to the animal, or to use the roller to redistribute the liquor after spraying it onto the back of the animal. Spray or roller devices fixed to a race or enclosure are other means for applying the treatments.

It has generally been found advantageous to treat only that part of the fleece growing on the back and flanks of the sheep in a band 30 to 50 centimetres wide and extending from the rump to the back of the neck, since this comprises the wool most susceptible to sunlight damage. In cases where 15 maximum protection is required the whole fleece can be treated with the sunscreen composition.

Preferably the amount of sunscreen composition applied to the sheep is sufficient to provide in the range of from 1 g to 50 g of screening agent per animal. It is preferred that the total amount of sunscreen composition applied is in the range from 20 to 500 ml per animal.

Microfine particles of materials such as metal oxides, which screen sunlight by reflecting it, are 20 examples of effective screening compounds. Titanium oxide powder of particle size 0.1 to microns, coated with a reagent to make it dispersible in an aqueous carrier, is the preferred reflective reagent. Examples of such materials are Tioxide TR92 and Tioxide R HD2 (Tioxide Australia Pty Ltd). Zinc oxide and aluminium oxide are other suitable materials.

Chemical agents which absorb specific wavelengths in the UVA, UVB and UVC regions of the ultraviolet spectrum are effective screening agents. Compounds showing strong absorption in the region from 280 to 400 nm and particularly from 280 to 350 nm are preferred UV absorbers.

Agents having a slow rate of degradation in sunlight when applied to wool grease in treatment mixtures are preferred UV absorbing agents. Benzotriazoles and triazines are the preferred types of UV absorbing agents and 2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol (Tinuvin 328, Ciba-Geigy Australia Ltd) is the preferred UV absorbing agent. Benzophenones, esters of para amino benzoic acid, cinnamate esters, and salicylates are suitable agents when mixed with reflective agents, benzotriazoles or triazines.

Specific examples of UV absorbing compounds include: 2(2'-Hydroxy-5'-methylphenyl)benzotriazole 2(2'-Hydroxy-5'-t-butylphenyl)benzotriazole2(2'-Hydroxy-4'-octoxyphenyl)benzotriazole 2(2'-Hydroxy-3'5'-di-t-butylphenyl)benzotriazole 2(2'-Hydroxy-3'5'-di-t-amylphenyl)benzotriazole 2(2'-Hydroxy-5'-t-octylphenyl)benzotriazole When added to sunscreening compositions anti-oxidants increase the effectiveness of chemical UV absorbing compounds, such as benzotriazoles, in preventing ultra violet light damage to wool.

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxy phenyl) propionate (Irganox 1076, Ciba-Geigy Pty Ltd) is the preferred anti-oxidant.

Various liquid carriers and additives may be used to adapt the compositions in the invention so as to obtain a suitable distribution of the components in the fleece to prevent weather damage. Water is the preferred carrier for compositions which include reflective particles. Various thickening agents, particularly cellulosic derivatives, and preservatives can be included to improve to improve the 15 efficacy of the compositions. Small amounts of surfactants or detergents may be added to improve the properties of the particulate dispersion, but must not be added in sufficient amounts to remove the grease from treated wool when it is wet by rain. Paraffinic and aromatic petroleum fractions, kerosene, mineral turpentine, hydrocarbons such as heptane, xylene, and toluene, esters including :esters of alkoxylated alcohols, alcohols, ketones, glycols and glycol esters are examples of solvents for use with UV absorber and anti-oxidant compositions. Emulsions in a water based carrier are also suitable for application of UV-absorbers and anti-oxidants.

All treatments rely on the retention of the applied reflecting and UV absorbing compounds in the grease component of the fleece of the sheep. The reduced degradation of the grease component by sunlight because of the applied treatments is an important factor in the durability of the protection imparted by the treatments to the wool component of the fleece. The addition of non-volatile materials of low water solubility, including fractions of wool grease, that are retained in the wool grease of the fleece, has been found to improve the effectiveness of UV absorbing and reflecting compositions for the prevention of weather damage to wool.

The present invention will now be more fully described with reference to the following examples. It should be understood, however, that the following description is illustrative only and should not be taken in any way as a restriction on the generality of the invention specified above.

EXAMPLE 1 This example demonstrates the reduced weathering of the fleece tip of wool from sheep which have been treated in accordance with the method of this invention.

14 weeks after the previous shearing, a single Merino sheep was treated on the back with an aqueous suspension containing 20 grams of a water dispersible titanium oxide product (Tioxide R HD2) in 100 ml of water containing 0.1 ml of an ethoxylated nonylphenol surfactant (Lissapol TN450, ICI Australia).

other untreated sheep were confined with the treated sheep in an open paddock in South Western Victoria.

After a further 30 weeks, samples of wool were taken from 2 separate sites on the backline of each of the sheep. Part of each sample was washed with water at 40*C for several minutes in the absence of any additives to simulate the effect of rain on the treated wool. No pigment was released from the greasy wool.

Another part of each sample was scoured using a conventional 4 stage laboratory scouring method with Lissapol TN450 at temperatures up to 60*C. This was found to completely remove all the pigment from the wool, as well as the dirt and grease. A Tip Weathering Index was determined on the scoured samples using the following test in duplicate.

Method for the Determination of Tip Weathering Index: Wool was treated for 15 minutes at 80°C and pH3 with excess solution containing 4 g Erional NW 20 Liquid (Ciba Geigy) and 0.2 g Ariavit Allura Red (Williams) per litre. The dye solution was rinsed from the wool, which was then air dried. The dye taken up by the wool was determined by extracting a weighed amount of wool with 50% iso-propanol at pH 10, 50°C for 1 hour. The amount of dye was determined by comparing the optical density of the extract at 510 nm with that of a known concentration of dye in a standard solution. A higher dye uptake is indicative of greater weather damage. The dye uptake, in the units mg dye per gram wool, is used as a Tip Weathering Index in this work. A correction was applied to allow for the small amount of dye taken up by greasy wool from the base of the samples.

The wool from the back of the treated sheep had a Tip Weathering Index of 0.7.

The wool from the backs of the untreated sheep had a mean Tip Weathering Index of 1.6.

The lowest value of Tip Weathering Index for any sample from untreated sheep was EXAMPLE 2 This example demonstrates the reduced effect of ultraviolet radiation on greasy sheep wool samples treated so as to provide a model substrate substantially similar to that which would be obtained on treatment of fleece wool in accordance with the method of this invention. It also demonstrates the improved performance that is obtained by adding anti-oxidant compounds to compositions containing UV absorbing compounds such as benzotriazoles.

Staples of greasy wool from a single merino fleece were cut to provide staple lengths of 70 mm of wool from the base part of the staple. The tips were discarded. 2.5 gram lots of the base wool were treated with 5 ml lots of aqueous emulsions containing various materials in 5% toluene, Lissapol TN450, by squeezing the wool and the liquor together between clean glass plates. The actual amounts of the various components in the emulsions, recorded as a percentage of the weight of greasy wool, are shown in the Table. After treatment the wool samples were left to equilibrate in air at room temperature for 3 days.

S Each treated wool sample was placed with all staples lengthwise into an aluminium tube 25 mm in diameter and 50 mm long. The staple ends were trimmed flush with the end of the tube to give a flat surface, with an orientation similar to that found on a merino sheep a few weeks after shearing. The tubes containing the treated samples were irradiated end-on for 22 days in a holder rotating with the samples equidistant from a 500 watt Philips ML lamp. The irradiation box was thermostatted at 0

C.

20 Several aluminium tubes containing untreated greasy wool were also prepared in the same way.

Duplicate samples were irradiated for 2, 7, 14, and 22 days.

After irradiation all samples were scoured and stained using the method outlined in Example 1.

Each stained sample was divided into 2 parts and each part was extracted and the optical density recorded as in Example 1. A correction was applied to all samples to allow for the small amount of dye taken up by unirradiated wool.

The data for the irradiated untreated wool samples were used to construct a curve of stain uptake versus irradiation time. Results for stain uptake for the treated samples were then read off this curve to determine an equivalent irradiation time that would be required for an untreated wool sample to reach the same level of stain uptake. A protection factor for each treatment was determined by dividing this number of days into 22, the actual number of days of irradiation for the treated samples. A higher protection factor indicates a better treatment.

RESULTS

GREASY WOOL TREATMENT PROTECTION FACTOR Tinuvin 328 4% Tinuvin 328 3.2 2% Tinuvin 328 3.3 Tinuvin 328, 10% Irganox 1076 16.8 4% Tinuvin 328, 4% Irganox 1076 9.1 2% Tinuvin 328, 2% Irganox 1076 4.6 Tinuvin 328, 10% Paraffin 5.9 4% Tinuvin 328, 4% Paraffin 2% Tinuvin 328, 2% Paraffin 3.2 All percentage values refer to the percent of that component on the weight of greasy wool.

EXAMPLE 3 This example compares the effectiveness of various types of UV absorbing compounds for reducing 15 the damaging effect of UV radiation on greasy wool.

The treatments, irradiation and analysis of the experiment were conducted as for Example 2, except that all materials were applied to greasy wool as solutions in toluene. Chimmasorb 81 is a benzophenone UV absorber from Ciba Geigy. Neo Heliopan OS is a salicylate based UV absorber, and Neo Heliopans AV and E 1000 are cinnamate based UV absorbers from Haarmann and Reimer.

RESULTS

GREASY WOOL TREATMENT PROTECTION FACTOR 4% Chimmasorb 81 4 S" 4% Chimmasorb 81 2% Irganox 1076 7 Chimmasorb 81 4 25 10% Chimmasorb 81 2% Irganox 1076 7 Neo Heliopan OS 3 Neo Heliopan OS 2% Irganox 1076 Neo Heliopan AV 4 Neo Heliopan AV 2% Irganox 1076 6 10% Neo Heliopan E 1000 3 Neo Heliopan E 1000 2% Irganox 1076 4 4% Tinuvin 328 6 4% Tinuvin 328 1% Irganox 1076 9 4% Tinuvin 328 3% Irganox 1076 11 4% Tinuvin 328 10% Irganox 1076 12 All percentage values refer to the percent of that component on the weight of greasy wool.

EXAMPLE 4 This example demonstrates the reduced effect of ultraviolet radiation on greasy sheep wool samples treated so as to provide a model substrate substantially similar to that which would be obtained on treatment of fleece wool in the method of this invention. In particular it demonstrates the effect of adding a particulate reflecting agent to suspensions of UV absorbing chemicals and an anti-oxidant applied to the wool.

Treatments were applied essentially as for Example 2, except that all materials were applied as suspensions in water containing 0.2% of a nonionic surfactant, Lissapol TN 450.

In the first series of treatments (SERIES A) the treated wools were allowed to dry in air before being placed in the aluminium tubes. In the second series of treatments (SERIES B) the damp wool was placed in the tube and trimmed flush with the end of the tube while still damp. The sample was then allowed to dry for 7 days before irradiation commenced. This second set of treatments might more accurately reflect the situation occurring when such treatments are applied to fleece wool on sheep.

Irradiations, weathering measurements and analysis of the experiment were conducted as for Example 2 GREASY WOOL TREATMENT PROTECTION FACTOR SERIES A SERIES B Tioxide R HD2 2 2 S Tioxide R HD2, 2% Tinuvin 328, 1% Irganox 1076 10 11 5% Tioxide R HD2, 4% Tinuvin 328, 2% Irganox 1076 9 24 Tioxide R HD2 3 2 Tioxide R HD2, 2% Tinuvin 328, 1% Irganox 1076 8 Tioxide R HD2, 4% Tinuvin 328, 2% Irganox 1076 8 Tioxide R HD2 3 3 20% Tioxide R HD2, 2% Tinuvin 328, 1% Irganox 1076 8 11 Tioxide R HD2, 4% Tinuvin 328, 2% Irganox 1076 12 43 All percentage values refer to the percent of that component on the weight of greasy wool.

9 EXAMPLE This example demonstrates the reduced weathering of the fleece tip of wool from the backs of lambs treated in accordance with the method of this invention. The experiment was designed to investigate the effect of the treatments on lambskins for the commercial wool-on skin market, where tip colour associated with weather damage is an important determinant of skin value.

The lambs were treated in South-western Victoria in August at an age of 6-8 weeks at the time of lamb-marking. 20 lambs were treated along the back with 40 ml of an aqueous suspension containing 4 g Tinuvin 328 and 1.6 g Irganox 1076 powder. The treatment was applied using a hand-held drench gun with a single broad jet. These lambs were then run with 20 untreated lambs.

Samples taken from the backs of treated and untreated lambs were measured for weather damage months later

RESULTS

TIP WEATHERING INDEX UNTREATED BACK WOOL 2.8 15 TREATED BACK WOOL 1.5 0.3 Based on the previous examples the decrease in weathering index due to the treatment would be expected to result also in a decrease in wool tip colour, and an improvement in the commercial value of the lambskins.

EXAMPLE 6 This example demonstrates the reduced weathering and the improved colour and brightness of the fleece tip of wool from the backs of sheep treated in accordance with the method of this invention. It also demonstrates that an increase in clean wool yield will be obtained as a result of the treatments.

18 Merino sheep were selected on Property A in Western Victoria and 24 sheep on Property B in Central Victoria. The sheep on each property were randomly selected into groups of 6 sheep. One group on each property was retained as an untreated control group.

GREEN TREATMENT GROUP: 4 weeks after the previous shearing, 6 sheep on each property were each treated with 100 ml of a solution in mineral turpentine of 10 g Tinuvin 328 and 2 g Irganox 1076.

BLUE TREATMENT GROUP: At the same time 6 other sheep on each property were each treated with 150 ml of a suspension of 4 g Tinuvin 328 powder, 1 g Irganox 1076 powder, and 20 g Tioxide R-HD2 in 5% iso-propanol.

RED TREATMENT GROUP: At the same time 6 sheep on property B were treated with 150 ml of an aqueous suspension of 20 g Tioxide R-HD2 in water only.

All treatments were applied with a paint roller as a strip 30 cm wide extending along the backline from the rump to the back of the neck.

All treatments were reapplied to the same sheep after a further 10 weeks. At the same time as the repeat treatments were applied (14 weeks after the previous shearing) a dyeband was applied at the base of the wool staples on 2 sites on the back of all treated and untreated sheep on each property.

36 weeks later wool samples were taken from 2 sites on the backline of each sheep which included the dyebanded staples. Care was taken to cut the samples as close as possible to the skin. 2 sheep were lost from the blue treatment group at property B. 10 of the 44 dyebanded regions on sheep at property B and 3 of the 36 dyebanded regions on sheep at property A could not be found.

The dyebanded staples from each sample were separated from the rest, and cut at the base of the dyeband. The tip and base fractions from each sample were separately scoured, air equilibrated and weighed. The amount of wool in the tip fraction was determined as a percentage of the total amount 15 of scoured wool for each sample. A higher Wool Tip Fraction Percent represents an increase in the amount of scoured wool recoverable as a result of the treatments.

S' All samples were scoured and the Tip Weathering Index was determined as in Example 1. After the scouring step, none of the samples retained more than 0.2% of material that could be removed by rescouring in heptane and alcohol.

Scoured samples from each of the 2 sample sites on the back of each sheep were combined, carded using hand-cards and rescoured. The reflectances of the samples from treated and untreated sheep 'were measured behind glass on a Macbeth Reflectance Spectrophotometer, and the Yellowness (Y-Z) and Brightness of the samples determined for Illuminant C. Lower values for Yellowness (shown by a decrease in and higher values for brightness are considered to be advantageous.

The fleeces from the Blue Treatment Group and the Untreated Group at Property A were collected at shearing and lightly skirted. The skirted wool and that from the backs of the necks was discarded.

The fleeces were then divided into back and non-back regions from each sheep in the approximate ratio 1:2 by weight. 4 lots were formed for processing to card sliver, namely, Untreated Backs, Untreated Non-backs, Treated Backs and Treated Non-backs. Each lot was scoured, dried and carded using identical conditions on the experimental processing line at CSIRO Division of Wool Technology. Tip Weathering Index and colour were measured on the card sliver from each lot.

11 Colour measurement was repeated on each of the sliver samples after rescouring as in Example 1.

Apart from colour, no significant processing differences were obtained between the treated and untreated lots in this experiment.

RESULTS

Results on fleece samples are presented as the mean the standard deviation for each measured wool characteristic and each treatment group. The number of samples in each group is shown in brackets.

Measurements on fleece samples Tip Weathering Index Yellowness (Y-Z) Brightness (Y) Tip Fraction Percent Property A, Western Victori en Treatment Blue Treatment 0 0.18 (12) 0.21 0.12 (12) i 0.2 -0.3 0.5 (6) 0 1.0 65.6 2.2 (6) 5 4.2 (10) 53.1 4.1 (12) a Tip Weathering Index Yellowness (Y-Z) Brightness (Y) Tip Fraction Percent Measurements on pre Property B, Central Victoria Green Treatment Blue Treatment Red Treatment 0.41 0.20 (12) 0.23 0.13 (12) 0.40 0.14 (12) -0.1 0.7 -0.1 0.2 -0.3 0.4 (6) 67.9 0.8 68.3 0.5 68.1 1.0 (6) 41.6 2.1 (10) 41.9 2.9 40.8 2.7 (9) pared sliver samples Property A, Western Untreated Back Untreated Non-back Treated Back 0.72 0.35 0.12 0.7 0.1 -0.9 64.6 67.5 69.3 Untreated 1.27 0.31 (12) 0.4 (6) 52.4 1.9 (6) 48.9 4.8 (11) Untreated 1.25 0.31 (12) 1.8 0.7 (6) 65.0 0.5 (6) 38.2 2.4 (7) Victoria Untreated Non-back 0.17 -0.3 70.3 -1.1 71.7 Tip Weathering Index Yellowness (Y-Z) Brightness (Y) Rescoured: Yellowness (Y-Z) Brightness (Y) -0.5 68.5 -1.0 70.6 -1.7 71.8 EXAMPLE 7 This example demonstrates the reduced weathering and the improved colour and brightness of wool from sheep treated in accordance with the method of this invention.

200 sheep on a property in Western Victoria were treated once only, 4 weeks after shearing with 150 ml of an aqueous suspension containing 30 grams of Tioxide TR 92 pigment. All treatments were applied with a paint roller as a strip 30 cm wide extending along the backline from the rump to the back of the neck. 200 untreated sheep were run with the treated sheep for the full year.

At shearing in the subsequent year the wool from the treated sheep was lightly skirted, formed into a 3-bale lot and sent for presale core and grab sampling and testing in the usual manner including yellowness The wool from the untreated sheep was handled similarly.

Core samples from treated and untreated wools, which provide a representative sample of all the wool in the lot, were also scoured and the Tip Weathering Index determined in quadruplicate as in Example 1. Results are presented as the mean and standard deviation of Tip Weathering Index determinations and the yellowness as determined by the testing house.

RESULTS

Tip Weathering Index Yellowness(Y-Z) UNTREATED WOOL 0.90 0.05 0.2 S* TREATED WOOL 0.72 0.07 -0.7 The treated wool exhibits an improved colour and less weather damage than the untreated wool.

EXAMPLE 8 This example demonstrates that various techniques can be used to apply treatments in accordance with the method of this invention.

130 sheep were each treated 4 weeks after shearing with 150 ml of an aqueous suspension containing grams of Tioxide TR 92 pigment using a Powerdoser applicator from Phillips Industries and a wand with 7 jets as developed for application of Eureka Gold from Young's Animal Health Pty Ltd.

Each dose was applied as a strip 30 cm wide extending along the backline from the rump to the back of the neck and required about 2 seconds for each application.

1000 sheep were each treated 4 weeks after shearing with 150 ml of an aqueous suspension containing 30 grams of Tioxide TR 92 pigment using a the Powerdoser applicator and a paint roller fitted to receive the material from a wand with 7 jets. The material was then rolled onto the back of 13 the sheep to give a strip 30 cm wide extending along the backline from the rump to the back of the neck and required about 20 seconds for each application.

Wool from treated and untreated sheep will be analysed at a later date.

Finally, it is to be understood that various other modifications and/or alterations may be made without departing from the spirit of the present invention as outlined herein.

Claims (9)

1. A method of protecting the hair or wool on the skin of living animals other than humans, comprising the application in a suitable carrier to the backs of said animals of substances that absorb or reflect ultraviolet radiation or act as antioxidants, either alone or in combination, wherein the applied materials are retained at least in part by the natural grease or lanolin on the wool or animal hair until the wool or hair is harvested, so as to provide a protective layer against the ultraviolet wavelengths present in sunlight.

2. The method in claim 1 wherein the applied materials are removable from the wool or hair during scouring by conventional processes used for removing grease, dirt and suint from the wool or hair.

3. The method in claims 1 and 2 wherein the carrier is water, or an aqueous solution of surfactants, or an organic solvent, or a mixture of organic solvents, or of an organic solvent and water. S

4. The method in claims 1 to 3 wherein the ultraviolet radiation absorbing or reflecting substances in a suitable carrier are applied to sheep or other animals by means of a hand-held single jet spray or multiple jet wand or fibre roller or by means of other hand-held or fixed S spray or roller devices known in animal husbandry.

5. The method in claims 1 to 4 wherein the treatment is applied to the animal one or more S times during the year.

6. Commercially more valuable wool with less weather damage and improved colour prepared from sheep treated by the methods in claims 1 to

7. Commercially valuable wool with increased yield after scouring due to treatment of sheep by the methods in claims 1 to

8. Commercially more valuable wool-on sheepskins and lambskins with less weather damage and improved colour due to treatment of sheep and lambs with the methods in claims 1 to

9. Treatments for protecting animal hair against sunlight damage during growth substantially as herein described with reference to the examples. Replacement page 14