CA1072507A - Hairsprays - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention is concerned with reducing the respirable fraction of sprays produced from an aerosol hairspray package.
An improvement is obtained by combining in the package a hairspray composition of particular viscosity, a propellant system producing a particular vapour pressure for discharging the hairspray composition through a mechanical break-up actuator with an actuator of which the cross-sectional area of the swirl channels, the diameter of the spray orifice and the diameter of the swirl chamber have a particular relationship.

Description

-~7;~507 ~ his invention relates to hairsprays and in particular to an aerosol hairspray composition in whicb a hairspray resin is dissolved in a liquid vehicle comprising a ~nixture of an ; organic solvent and a propellant liquid, which composition is S packaged within a container fitted with a discharge spray valve comprising a mechanical break-up actuator. When the actuator ol~ the valve is operated the composition is discharged in aerosol form through the outlet or terminal orifice in the actuator, by the pressure within the container. Many marketed aerosol hairsprays are of the above type at the presen-t time.
When a composition is discharged as an aerosol from a pressurised pack, some of the aerosol particles may be inhaled by the user or by other persons in the vicinity. The proportion of the product discharged which is capable of ; 15 reaching and being deposited in the lung and is called herein the "respirable fraction" of the product. Industry is concerned that the user should not be exposed unnecessarily to respirable particles (see the article "Health related hazards of aerosols" by J.J. Sciarra published in Aerosol Age, Dece~ber ; 20 1977, page 4~).
- ~his invention is concerned with providing an improved aerosol hairspray package.
; According to the present invcntion there is provided a package for containing and dispensing a hairspray resin, including in combination a con-tainer having a spray valve provided with a mechanical hreak-up actuator for dispensing a liquid in aerosol ~orm and a composition within the container :'' .,. ~ ~

- 2 _ ' ':

... . .

~la 7Z5~7 comprising a solution of a hairspray resin in a liquid vehicle comprising a mixture of an organic solvent and a liquefied propellant, wherein (A) the viscosity of the composition is 0.80 to .4.00 centistokes, preferably 0.85 to 2.00 centistokes, at 25C;

(B) the pressure within the container is from 20 to 42 psig at 25C; and (C) the mechanical break-up actuator is such -that ~/D1D2has a value up to 0.80 Such as from 0.15 to 0.80 (eg 0.50 to 0.-~0) wbere Z is the sum of the cross-sectional areas of the s~irl channels of the actu~tor;
D1 is the diameter of the spray (terminal) orifice of the actuator; and D2 is the diameter of the swirl chamber of the actuator. ~.

Preferred features of the package of the invention are (D) the diameter of the housing orifice (also known as the body orifi.ce or tail piece orifice) o~ the valve or, in the case where the dip tube of the valve is fitted within the housing orifice, the internal diameter of the dip tube is at least 25 x 10 3 ins, eg 25 to 150 x 10 3 ins; and (E) the valve does no-t have a vapour phase tap.

- 3 - /---. .
' '' ' ''' " ' " '' : .

~C~7Z~i~7 Preferably both of the lat-ter features (D) and (E~ are part of the package of the invention.
For a discussion of the construction of aerosol valves reference is made to chapter 6 of "Principles of Aerosol Technology~ by Paul A. Sanders (1970). ~ typical mechanical - break_up actuator is described in British Patent Specification No.799~68 (The Risdon Manufacturing Company) the drawings of which illustrate a spray valve having four s~irl channels 58 leading to a s~irl chamber 52 from ~YhiGh liquid emerges through the spray orifice 68. Commercially available mechanical ; break-up actuators usually have two, three or four swirl channels and in some forms the channels taper towards the swirl chamber. The value of Z for an actuator with tapering swirl channels is the sum of the mean values of the cross-: --. 15 sectional areas of the channels.
The hairspray resin is preferably included in the composition in an amount of from ~.1 to 7.5% by weight.
The hairspray resin may be any of those known to be suitable for holding the hair in a desired style. Amongst 2~ those that have found ~Yide commercial application are polyvinyl-pyrrolidone; copolymers of from 92.5 to 87.5% vinyl acetate and from 7.5 to 12.5% crotonic acid as described in US Patent No.2~996j~71, eg National Starch Resyn 28-1310; terpolymers of from 7 to 89% vinyl acetate9 6 to 13% crotonic acid and from 2S 5 to 80% of a vinyl ester of an alpha-branched saturated aliphatic monocarboxylic acid having a minimum of five carbon atoms in the carboxylic moiety, said acid having the formula ''' ' ~ ~ ~ /- -~'' '' .
, ~1~7ZSO7 R3C(R1)(R2)COOH where R1 and R2 are alkyl radicals and~R3 is selected from hydrogen, a].kyl7 alkaryl, aralkyl and aryl radicals, such terpolymers being described in British t~ 3l~J0~9~ 4~ ~ 7~
Specification ~o.1,169,862 and US~ pplication Scrial No.~5,~3~, and similar terpolymers being described in US Yatent No.3,5~9~629, a commercially available terpolymer of -this type being that sold under the name National Starch Resyn 2~-2930; copolymers of from 20 to 60~o of N-vinyl pyrrolidone and from ~0 to 8~C/o of vinyl acetate such as those described in US Patent ~o.39171,784, - 10 and which copolymers are commercially available under the designations Luviskol 37E and Luviskol 28I; copolymers of maleic anhydride (1 mole) and an olefin (1 mole) containing 2 .. .. . .... . . . . ....
to 4 carbon atoms9 particularly ethylene, said copolymer having a ~olecular weight of about 25,000 to 70,00~, preferably being esterified to the exten-t of 50 to 70% with a saturated aliphatic alcohol containing from 1 to 4 carbon atoms~ such as are described in US Patent No.29957,838; amphoteric acrylic resins as described in ~S Patent No.3972692~8 and available commercially . under the trade name Amphomer;. and copolymers of methyl vinyl ether and maleic anhydride (rnolar ratio about 1:1) and such ; copolymers esterified with a saturated aliphatic alcohol containing from 1 to 4 carbon atoms9 an example thereof being the resin available commercially under the trade name Gantrez ES ~35.
~owever, those skilled in the art will appreciate that other resins are suitable for use in hairsprays, see for example the section entitled "~air Lacquers or ~air Sprays", commencing on . page 35Z of Volume 2 of "Cosmetics Science and Technology"
: edited by M.S. Balsam and Edward Sagarin (1972~.

'~ ' ' :, ~7Z507 Those copolymers T~hich contain acidic group~ and are water-insoluble are usually used in their neutralised water-soluble formO Suitable neutralising agents which may be included in the hairspray composi-tion are amines, especially aminoalcohols, preferably 2-amino-2-methyl-1,3-propanediol and 2-amino-2-methyl-1-propanol. Other suitable neutralising agents are also given in US Patent No.2,996,471.
Organic solvents for the hairspray resin which are commonly used in formulating hairspray compositions are ethanol9 isopropanol~ methylene chloride, methoxyethanol and 2-ethoxy-ethanol, and mixtures thereof with water.
The propellant gases used in formulating aerosol hairsprays are well known to those skilled in the art. The propellant is usually a halogenated hydrocarbon~ the fluorochlorohydrocarbons i5 of the C1 and C~ alkanes being the most ~ell known, or a liquefiable hydrocarbon. Commonly used propellants are trichlorofluoromethane (propellant 11), dichlorodifluoromethane (propellant 12), butane and propane9 and mixtures thereof.
Other suitable propellants are referred to in US Patents Nos.
20 39026,2509 39145,147 and 299579838, and more general:ly in the section entitled "Propellants" commencing on page 443 of Volume 2 of "Cosme-tics Science and Technology" referred to previously.
The hairspray colnpositions of this invention may contain 2~ adjuvants conventionally used in compositions of this type ~or example plasticisers, perfume.s9 dyestuffs and anti-seborrhoeic agents. Suitable anti-seborrhoeic agents are described in - 6 _ /

~L~7Z5(~7 British Specifications Nos .1 9 296,102 and 1,305,358.
Polydimethylsiloxane-polyoxyalkylene copolymers as described in British Specification No.1,42~,002 may also be included.
The respirable fraction of the particles produced by an 5 aerosol pack was determined in the following experiments using an IIexhlet elutriator (Brit. J. industr. Med.~ 19549 119 28~) which separates particles according -to their falling ~elocities in the air. The aerosol is drawn at a controlled hori~ontal veloci-ty through a parallel plate elutriator; the vertical spacing of the plates is such that particles settling on them during the transit of the aerosol through the elutriator correspond to those which would separate aerodynamically in the upper respiratory tract of man. Thlls the particles passing through the elutriator and collected on a filter represent those which would penetrate to the human lungs. The upper aerodynamic si~e limit for respirable particles collected in the Hexhlet is about 7 microns.
,' The procedure was as follows. A filter, dried and weighed, was loaded into the Hexhlet sampler and the pressurised pack to be tes-ted was weighed. The ,-~acuum was adjusted so that the gauge on the Hexblet showed about 300 mm Hg.
~fter thorough shaking the aerosol was sprayed in-to a cabi~et fitted to the front of the Hexhlet sampler, each spray was of 2 second duration, the sprays being repeated with shaking every 2~ second for a total of 20 sprays. Sampling was continued '-~ for 5 minutes after the last spray. The pack was re-weighed ', - -to gi,ve the weigbt of product di,scharged. The weight collected .

- 7 ~ /.., ,: .
.

~ 725l~)7 ; is expressed in milligrams per 1~ g of product discharged.
This weight is a measure of the respirable material irl an aerosol cloud. In order to be able to compare respirable fractions obtained from products containing different amounts of resin9 it is necessary to allow for the evaporation of the solvents from the droplets in the aQrosol cloud during sampling9 and this is effected by dividing the respirable fraction (mg/100 g) by the percentage weight of the resin in the productg the quotient being referred to herein as the Corrected Respirable Fraction.
The measurement of respirable fraction was carried out at a relative humidity of 50% and a temperature of 20C.
Experiment,s will now be described illustrating the effect of the above parameters on the corrected respirable fraction of an aerosol spray~ Measurements of viscosity and pressure were ~--carried out at 25C unless stated otherwise. In all cases~ -prior to ~illing with propellant all aerosol cans were purged of air: Percentages are by weight.
The effect of can pressure, formulation viscosity and mechanical break-up actuator on the corrected respirable fraction is illustrated in Table I.

. , .

/ - - -~Z5()~

TA~I,E I
___ __ ___ ______ _ Can Pressure Formulation Value of Z_ Corrected (psig) Visco~ity for D D2 Respirable (centistokes) Actuator 1 Fraction ___ ____ _ _ __________ ____ S 3z I _ _0.8Z _ _ L _.6 _ _ 10 _ ~ _ ~ 1.7 ~ 0'7 0.82 0.66 24 0.75 33 ~0 - - 1-.~ -- L o 66 - = -i The compositions employed in the experiments summarised in ~able I had a product to propellant ratio of 40:60. The product consisted of a solution of National Starch Resyn 28-1310 (a copolymer of vinyl acetate (90%) and crotonic acid (1~)) in ethanol. The lower viscosity composition contained 0.8% resin and the higber viscosity one 3~0 resin. The products also co~tained 10% based on the weight o e the resin of amino methyl propanol as a neutralising agent. In each case a blend of Propellants 11 and 12 were used, -the ratios being 70:30 and 50:50 in the case O:e the lower and higher pressure compositions, respectively.

~ 9 ~7Z5~7 :
In these experiments the same valve was llsed. The housi,ng orifice of the valve had a diameter of 80 x 10 3 ins.
The effect of formulation viscosity on tlle corrected respirable fraction is also shown by the data given in Table II
; 5 below. In this case the can pressure (46 psig) was constant and the same valve and actuator were used, the latter having a ,; /D1D2 value of O.i8 The housing orifice of the valve had a ' diameter of 80 x 10 ins.
. .
'' TABLE II --, - 10 ~nount of Resin Fornnulation Viscosity Corrected Respirable ~ (%) (centistokes) Fraction :' _ _ ._ __ _ __ ' 0.2 ~.2~ ~00 O .5 ~. 25 265 1.0 0.3~ 200 ' 1.8 ~.~5 17 ~' 3.0 ~.8~ 75 `................. 4.0 1.35 30 _ _ __ _ : In the experiments whose results are reported in Ta'ble II, the resin employed was National St,arch Resyn 28-2930 (a terpolymer O-r vinyl acetate (75%)7 crotonic acid (10%) and a vinyl ester of a 'branched chain fatty acid (i5%) ) . Amino methyl propanol in an amount oi' 10% 'based on the weight of the resin as a neutralising agent was also present. The 25 formulations had the following composition:

,, - 1 0 - / - -~97%~07 Prodllct Res:in as speci.riecl in Table II
NeutYal:i9illg agent10% Of resin Ethanol to 15 Propellan-t l':ropellant 11 51 Propellant 12 34 Ttle e.f'.t'ect o:t' variation in the value of the ratio Z/D1D2 :ror the actllator of the valve is also shown by the data giver 1l:) in Tabl,e III. , TABLE III
2 Corre _ed Respirable Fraction , 0.36 1~
0.66 28 0.75 38 ().~5 ~6 :l.10 52 The data in Table III were obtained employing a hairspray having the following composition:
2 0 o/o National Starch Resyn 28-1310 2.0 Amino methyl propanol 0.2 ¢thanol 37.8 l'ropellants 1l/12 (ti5:35) 60.0 : -- 11 -/ ., .

~ ~7;~51~7 This composition had a v-iscosity of 0.9~ centistokes and the pressure within the aerosol container was 36 psig. The housing orifice ol the valve had a diameter of 80 x 10 3 ins.
The results of experiments showing the effect of the diameter of the housing orifice on the corrected respirable fraction are summarised in Table nr.
TABLE IV

.
_____ ___ __ ________ .....
~ousing Orifîce Corrected Respirable (thousandths of an inch) Fraction __ _ . _ ___ _____ : 1~) 13 52 ` 80 22 ___ _ _ _ __ In the experiments on which t~e results of Table IV are --based there was used a Formulation containin~ 2yo of National Starch Resyn 28-1310. The remainder of the composition consisted of amino methyl propanol (0.2%) ~ ethanol (37.8%) and a 65:35 blend (60%) o-F propellants 11 and 12. The composition had a viscosity of 0.94 centistokes and the pressure within the aerosol con-tainer was 36 psig. T~le same actuator was used throughout -this experiment and it had a /DlD2 value of 0. 43.
In all the above experiments the valve employed had no vapour phase tap. Use of a vapour phase tap leads to an increase in the respirable fraction. This can be seen from the following Table V ~hich gives values for the corrected respirable fractions for two pairs of packages the individual .

i ~7;2~

packages of each pair differing only in that -the spray valve of one had a vapour phase tap whereas the other did not.
For the second pair a spray valve with a larger housing orifice was employed.
TAB LE
.
. =

Housing Orifice Housing Orifice D i ame-t e r o f D i amet er o f 25 x 10-3 ins ~0 x 1[)~3 ins ___ __ _ . ~ ___ 10 No vapour phase tap 136 64 ~apour phase tap of 204 ~3 L 13 x 10-3 ins L _ The formulation of the aerosol composition was as follows:
0~
National Starch Resyn 28-2930 1.10 Amino methyl propanol O . li Ethanol i3 . 79 Propellant 11 - 51. 00 Propellant 12 34 . 00 This composition had a viscosity ol' 0.32 centis-tokes and the pressure within the aerosol container was 46 psig. Tbe value of the ratio Z/D1D2 for the mechanical break-up actuator was 0.43.
The following Examples illustrata the use of hydrocarbon 25 propellants.
, .

-- 13 -- / . . .
:;

:~
.

~7;2S~7 Composi-tion Example 1 E~ample 2 National Starch Resyn 28-2930 2.30 2.30 A~ino metbyl propanol0.23 0.23 Sucrose octaacetate 0.10 0.08 Perfume 0.20 0.20 Water 10-.`00 Methylene chloride - 25.00 Hydrocarbon propellant16.00 18.00 Industrial methylated spiritto 1~0.00 to 100.00 .
- 10 Viscosity of composition1.51 1.10 (centis-tokes) Pressure within the aerosol 36 25 container (psig) Actuator Z/DlD2 ratio0.36 0.36 Diameter of ~ousing orifice 80 80-(x 10-3 in) Gorrected respirable fraction 8 10 The spray valves employed had no vapour phase tap.
The hydrocarbon propellant was Calor Aerosol Propellant - 20 Grade 30~ a commercial hydrocarbon blend consisting mainly of - a mixture of propane and butanes having a vapour pressure of about 30 psig at 21C.
In all the aerosol products referred to above the aerosol valve was provided with a so-called standard dip tube, ie the dip -tube was fitted over the end of the valve tail piece. Tbe - dip tubes employed had an internal dian~eter in -the range from ~ 80 to 120 x 10- ins. However, it is possible to employ so-~6~7Z507 called capillary dip tubes which fit within the housin~ ori~ice.
In this case it is required that the internal diameter of the dip tube is at least 25 x 10 3 ins. Increasing the diameter of ` the capillary dip tube acts to reduce the va~ue of the corrected respirable ~raction. Capillary dip tubes usually have an internal diameter up to about 60 x 10 3 ins.

:..

.,.', ' , .

- 15 _ **~

. . .
'

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A package for containing and dispensing a hairspray resin, including in combination a container having a spray valve provided with a mechanical break-up actuator for dispensing a liquid in aerosol form and a composition within the container comprising a solution of a hairspray resin in a liquid vehicle comprising a mixture of an organic solvent and a liquefied propellant, wherein (A) the viscosity of the composition is 0.80 to 4.00 centistokes at 25°C;

(B) the pressure within the container is from 20 to 42 psig at 25°C; and (C) the mechanical break-up actuator is such that Z/D1D2 has a value up to 0.80 where Z is the sum of the cross-sectional areas of the swirl channels of the actuator; D1 is the diameter of the spray orifice of the actuator; and D2 is the diameter of the swirl chamber of the actuator.

2. A package as claimed in claim 1, wherein the diameter of the housing orifice of the valve or, in the case where the dip tube of the valve is fitted within the housing orifice, the internal diameter of the dip tube is at least 25 x 10-3 ins.

3. A package as claimed in claim 1, wherein the valve does not have a vapour phase tap.

4. A package as claimed in any of claims 1 to 3, wherein the viscosity of the composition is from 0.85 to 2.00 centistokes at 25°C.

5. A package as claimed in any of claims 1 to 3, wherein Z/D1D2 has a value of from 0.15 to 0.80.