Rheological Additives in Cosmetics

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					Rheological Additives
in Cosmetics

             pure i n cos m e t i cs
                                  Today’s successful cosmetics products
                                   need the right rheological properties.
                           And the correct choice of rheological additive
                                   enhances the product in production,
                                        storage stability and application.
                            ELEMENTIS Specialties rheological additives
                             for aqueous and non-aqueous formulations
                            are valuable and proven tools for you to use.
                                        Personal care, skin care, sun care

Personal Care                                  and decorative cosmetics;
                                  single-phase, suspension or emulsion;
                                                     all can benefit from
Skin Care                                         ELEMENTIS Specialties
                                                   rheological additives.
Sun Care
Decorative Cosmetics

pu re i n co s m e t ics

Introduction                                  2

Cosmetics and Rheology                        4

ELEMENTIS Specialties Rheological Additives   6

Hectorite - The Benefits                      6

Aqueous-Phase Additives                       7

       •	  BENTONE® Hydrophilic Clays         7

Non-Aqueous-Phase Additives                   9

       •   BENTONE® Organophilic Clays        9

       •   BENTONE GEL®                       10/11

       •   THIXCIN® R Rheological Additive    12

Product Application and Selection             13

Incorporation & Equipment Guideline           14

INCI References                               15

Applications Table                            16/17





are trade names of

ELEMENTIS Specialties
    Cosmetics and Rheology
Strong partners to create the best possible products

            Rheology is the science of flow. Every time a lotion is
              poured, a cream squeezed from a tube or a lipstick
           applied, rheology is involved. Even when products are
                  at rest, it plays an important part in controlling
                                          stability and suspension.

                Understanding a formulation’s rheological needs
                enables you to create the best possible products.

                            The rheology of a system is described
                                           in terms of its viscosity.
                Viscosity is the resistance to flow and defined as:

                Shear stress is the force per unit area applied and
                      shear rate is the resulting velocity gradient.
                        Cosmetics experience shear rates varying
                         from 0.001 s-1, from gravitational forces;
                   to over 20,000 s-1, when a cream is spread or
                         an aerosol antiperspirant sprayed (Fig 1).
The way the viscosity changes at varying shear rates
greatly influences the overall product stability and        The rate of recovery of a system when stress is
performance. A material which maintains a constant          removed is also very important. When a shear
viscosity, regardless of shear rate, has Newtonian flow     thinning system shows delayed viscosity
(Fig.2). Dilatant flow (Fig.2) is a form where viscosity    recovery, it is described as thixotropic (Fig.3).
increases with shear, sometimes encountered in highly       This is one of the most important types of flow in
pigmented/filled systems.                                   cosmetics. Controlling the degree of thixotropy
                                                            enhances the application of a cream, eliminates
Pseudoplastic flow (Fig. 4), also known as shear thinning   dripping of a roll-on antiperspirant or allows
behaviour, and typical of many commercial systems,          brushmarks in a coat of nail lacquer to disappear,
is when viscosity decreases with increasing shear rate.     leaving a smooth film.

Flow may require a specific stress to be initiated. This    Viscosity can be temperature dependent.
particular stress value is known as the yield point.        Correct choice of rheological additive allows you to
A system having both shear thinning flow and a yield        create the ideal flow characteristics (Fig. 1) and
point can be described as having plastic flow.              also achieve thermostable rheology.

ELEMENTIS Specialties
 Rheological Additives
        for Cosmetics
           Improving aqueous, organic and
                 emulsion-based products

   ELEMENTIS Specialties rheological additives can be
  broadly divided between aqueous-phase thickeners
                    and non-aqueous-phase thickeners.
       But it is important to remember the advantages
    of oil-phase viscosity modification that can greatly
                      improve emulsion based products.
     ELEMENTIS Specialties additives for cosmetics are
                  based on naturally occurring materials:
                         highly refined and beneficiated
                   hectorite clay or castor oil derivatives.
Aqueous-Phase Additives

Hectorite - The benefits                                        BENTONE® Hydrophilic Clays

Hectorite is a unique swelling clay offering several           BENTONE® MA, EW, and LT rheological additives
advantages. Hectorite’s special properties, compared           provide thixotropy and suspension control to the
with bentonite, are:                                           aqueous phase.

   lower iron content                                          BENTONE® MA and EW additives form gels by producing

   lighter colour                                              an open, 3-dimensional network of the individual clay

   higher swelling capacity                                    platelets as shown in Figure 5.

   greater gel strength
   no crystalline silica                                       The two products are stable across the range pH 6-11
                                                               and offer good tolerance to electrolytes.
Due to its small size, platelet shape and large surface
area, hectorite is able to form strong, stable viscous gels.   BENTONE® LT forms a similar network,
                                                               but it is strengthened by the presence of a special
                                                               cellulose, greatly enhancing stability and thickening
                                                               characteristics. BENTONE® LT is stable across a
                                                               broader range, pH 3-11, and is also the least
                                                               electrolyte-sensitive product.

                                                               BENTONE® MA and EW are in compliance with ECOCERT;
                                                               The ecological and organic cosmetics standards.

Hectorite is a very effective thickener of water. Because
of this and its other exceptional properties, it forms the
basis of the BENTONE® hydrophilic clays.

     p u r e i n co s m e tics
INCORPORATION Hydrophilic Clays


  Medium to high-shear mixing
  Add clay to water before addition of other

  Disperse at moderate pH

  Low shear (< 10 ms-1)

  = long mixing time (> 30 mins)
  High shear (> 15 ms-1)
  = shorter mixing time (10-15 mins)

  10 minutes hydration before adding other

Water at up to 60°C (140°F) reduces hydration time

It is important to have only unadulterated water
present at the dispersion stage. Surfactants or
electrolytes should not be added until dispersion is

For additional guidance see page 14
Non-Aqueous-Phase Additives

BENTONE® rheological additives are non-abrasive.         BENTONE® Organophilic Clays
The skin feel imparted by BENTONE® hydrophilic clays
is a pleasant silkiness, quite different to that         Hectorite is now reacted with special vegetable
associated with the majority of cellulose, polymer       quaternary ammonium salts to produce organoclays
and polysaccharide-based thickeners.                     able to thicken and gel organic liquids. The correct
                                                         choice of BENTONE® additive is determined largely by
Furthermore, as hectorite itself is insensitive to       the polarity of the system to be thickened.
temperature variations, the BENTONE® products impart
a thermostable viscosity control.
                                                         Additive             Application
Surfactants can influence the rheological behaviour
of hydrophilic clays.
                                                         BENTONE® 27 V     •	 Intermediate to high-polarity
                                                                              organic systems such as esters
                                                                              and triglycerides - for nail lacquers,
Non-ionic surfactants, if they are highly ethoxylated,
                                                                              skin care, antiperspirants and
can adsorb onto the clay surface. This rarely causes
                                                                              lip products
problems either in flow control or activity of the
                                                         BENTONE® 38 V     •	 Low to intermediate-polarity
                                                                              organic systems such as volatile
Anionic surfactants can act as dispersing agents and
                                                                              silicones and mineral oil - for
weaken the gel structure. Alternatives that eliminate
                                                                              antiperspirants, creams, lotions,
or minimise any problems can normally be found.
                                                                              eye products and suntan products
However, cationic surfactants interact strongly and
should be avoided.

Organic and silicone-based liquids used in oil and
wax-based cosmetics, and as the non-aqueous-phase in
emulsions, benefit greatly from ELEMENTIS Specialties
rheological additives. Outstanding rheological
properties are developed using BENTONE® organoclay
rheological additives in their powder form or,
even better, with BENTONE GEL® additives, their
predispersed forms.

The benefits gained are:

    thermostable viscosity control

    thixotropic flow

    suspension control of pigments and actives

    emulsion stabilisation
    silky skin feel

BENTONE® additives need to be efficiently dispersed
using high-shear equipment and then to be activated
with the optimum level of a chemical activator, such
as propylene carbonate.

BENTONE® organoclays form thixotropic gels by
developing hydrogen bond bridges between the
edges of adjacent platelets as shown in Figure 7.

                                                        BENTONE GEL®

                                                       BENTONE GEL® additives are optimally dispersed
                                                       and activated predispersions of ELEMENTIS Specialties

                                                       Benefits include:

                                                       •   optimally dispersed

                                                       •   high-shear dispersion not necessary

                                                       •   no polar activation required

                                                       •   easy to handle and use

                                                       •   can be added at any appropriate and
                                                           convenient stage in manufacture

                                                       A wide range of gels made from various cosmetics oils,
                                                       esters and solvents are available.
                                                       The use of a BENTONE GEL® enables you, the formula-
                                                       tor, to achieve the maximum efficiency from the
                                                        organoclay without the need for careful shearing and
                                                         activation. On the production scale, time is saved
                                                          and the highest degree of reproducibility attained,
                                                            leading to potenial cost savings.

BENTONE GEL® additives can be added at any
convenient suitable stage in the manufacturing cycle.
BENTONE GEL® additives are very high-viscosity, shear
thinning products. To ensure good homogeneous
mixing is achieved, care must be taken to overcome
large viscosity differentials existing between the
BENTONE GEL® and the other lower-viscosity
components. Choice of mixing equipment and the
configuration within the mixing vessels are critical
factors in developing the optimum performance of
the BENTONE GEL® additive. The use of medium- to
high-shear mixing equipment is recommended.

For additional guidance see page 14

Batch Processing

•	 Single-Phase Systems
   Always add the BENTONE GEL®, under shear,
   to a portion of the organic component or solvent
   with which it is most compatible. Mix until
   homogeneous before adding the other ingredients.

•	 Multi-Phase Systems (eg. emulsions)
   As for the single phase, but always ensure the
   BENTONE GEL® additive is thoroughly mixed in
   before the emulsification stage.

Continuous processing

The BENTONE GEL® should be added to the oil phase at
any convenient point that meets the above guidelines
for the batch processing. In multi-manifold systems,
a flowable pre-mix of the BENTONE GEL® with a
compatible oil or solvent should be made in a side pot.

Where only lower-shear mixing equipment is available,
stir the BENTONE GEL® alone, in a small mixing vessel,
if necessary, and then slowly add the most compatible
component by portions, always ensuring the mixture is
homogeneous at each stage.

     THIXCIN® R Rheological Additive

     For the highest degree of thixotropy in aliphatic liquids,   INCORPORATION THIXCIN® R additive
     THIXCIN® R additive is the product to use. In addition to
     its effective rheological properties, it gives water
                                                                  High-shear mixing
     repellency, stabilises emulsions and acts as a stiffening
                                                                  Add THIXCIN® R to oil
     agent in lipsticks and ointments. It can also be used as
                                                                  Disperse to deagglomerate
     a dry binder in pressed powder systems.

     (Where high-temperature resistance is needed,
                                                                  Temperature range 55-60°C (130-140°F)
     BENTONE® or BENTONE GEL® additives are
                                                                  Shear for 20 minutes within this temperature range
     THIXCIN® R is a castor oil derivative. It requires
                                                                  to activate
     temperature-controlled activation within the range
     55-60°C (130-140°F) and high-shear mixing to develop
     its full structure.
                                                                  Maintain shear to below 35°C (95°F) when cooling
     THIXCIN® R is in compliance with ECOCERT; The ecologi-
                                                                  For additional guidance see page 14
     cal and organic cosmetics standards.

                                                                  p ure in cos m etic s
Product Application
and Selection
Choosing the right
rheological additive
Cosmetic products range from pressed
dry powders to suspensions in liquids;
from single-phase solid or liquid
formulations to emulsions. The choice
of rheological additive and level of use
depends on the system and the desired
performance criteria (Table pages 20/21).

The properties imparted by the rheological
additive benefit different cosmetics in different
ways. The advantages of using ELEMENTIS
Specialties rheological additives are
not always only the obvious ones, for instance:

Stick products (lipstick and antiperspirant)

   maintain homogeneity in molten and setting stages

   gain improved pay-out

   increase high-temperature integrity

   eliminate oil migration
   reduce “creasing” around lips and eyes


  improve film-build

  increase water-resistance
  eliminate oil migration

  elevate drop-point temperature

  of water-in-oil creams

  eliminate syneresis

  improve emulsion stability

  enable cold-process emulsification
  create novel viscosity effects

UV Sunscreen

  eliminate ultrafine Ti02 skin-whitening problems

  enhance sun protection factor (SPF)

  optimise use of sunscreen actives
  reduce separation and settlement

Antiperspirant Aerosols

  uniform distribution of active ingredients

  soft and dry skin feel

  significant less whitening
  reduced separation and settlement

          Incorporation & Equipment Guideline

          Shear Development      Low                Low              Medium             Med-high         Med-high           Very high
          Generic Type           Paddle             Propeller        Planetary          Rotor/stator     Impeller           Homogeniser

          BENTONE® MA, BENTONE® EW and BENTONE® LT additives – powders needing high-energy mixing

          Conditions             Suitable only for                   Suitable for BENTONE® MA, EW, LT additive              Suitable for
                                 BENTONE® EW additive                                                                       BENTONE®
                                 Use highest speeds                  Use highest speeds and carefully                       MA, EW, LT
                                 (> 3000 rpm).                       observe optimum mixer/vessel                           additives.

          Order of addition      Clean water and rheological additive only.
                                 Avoid addition of surfactants or electrolytes until dispersion completed.

          Special factors        BENTONE® EW < 5                     BENTONE® MA                 <10%
                                 pH of water neutral.                BENTONE® EW                 < 5%
                                 Sift clay in gradually. Add         BENTONE® LT                 < 4%
                                 defoamers, if needed, only          pH of water neutral.
                                 after dispersion completed.         Sift clay in gradually.

          BENTONE® 27 V and BENTONE® 38 V additives – powders needing high-energy mixing

          Conditions             Unsuitable –                        Suitable for BENTONE® 27 V                              Recommended
                                 insufficient shear.                 and 38 V additives.                                     for
                                                                     Use highest speeds and carefully                        BENTONE® 27 V
                                                                     observe optimum mixer/vessel                            and 38 V
                                                                     configuration.                                          additives.

          Order of addition      N/A                                 Oil or solvent alone.
                                                                     Add organoclay and disperse.
                                                                     Add polar activator and continue dispersing.

          Special factors        N/A                                 Ensure full wetting achieved before activation.
                                                                     Use optimum level of polar activator.
                                                                     Avoid the presence of surfactants until after activation.

          BENTONE GEL® rheological additives – optimally dispersed and activated gels

          Conditions             Use maximum speed                   Use highest speeds and carefully                       Add gel to
                                 and dilute gel stepwise             observe optimum mixer/vessel                           vessel, apply
                                 under shear.                        configuration.                                         shear prior to
                                 Min. 10 mins @ > 1500 rpm.                                                                 adding other
                                                                                                                            by increments.

          Order of addition      Gel first, then oil or solvent      Add gel to portion of oil/solvent                      Add oil to
                                 in ratio 60:40 gel to oil.          under shear. Maintain shear                            gel stepwise.
                                 Mix and add other                   until homogeneous.
                                 components in steps.

          Special factors        Ensure mixture is                   Ensure mixture is homogeneous at each dilution stage.
                                 homogeneous at each                 Particulate materials, such as antiperspirant salts
                                 dilution stage until flowable       will assist in the dispersion in low-viscosity media.
                                 consistency achieved.


INCI References
BENTONE® MA         Hectorite
BENTONE® EW         Hectorite
BENTONE® LT         Hectorite, Hydroxyethylcellulose

BENTONE® 27 V       Stearalkonium Hectorite
BENTONE® 38 V       Disteardimonium Hectorite

THIXCIN® R                 Trihydroxystearin

BENTONE GEL® CAO V         Ricinus Communis, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® SS71 V        Petroleum Distallates, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® DOA V         Dioctyl Adipate, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® EUG V         Octyldodecanol, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® GTCC V        Caprylic/Capric Triglyceride, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® HSO V         Helianthus Annuus (Sunflower) Seed Oil, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® IHD V         lsohexadecane, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® IPM V         lsopropyl Myristate, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® ISD V         lsododecane, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® LOI V         Lanolin Oil, lsopropyl Palmitate, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® MIO V         Mineral Oil, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® OMS V         C11-12 lsoparaffin, Disteardimonium Hectorite, SD Alcohol Denat
BENTONE GEL® OP V          Octyl Palmitate, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® PTIS V        Pentaerythrityl Tetraisostearate, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® PTM V         Phenyl Trimethicone, Disteardimonium Hectorite, Triethyl Citrate
BENTONE GEL® TN V          C12-15 Alkyl Benzoate, Stearalkonium Hectorite, Propylene Carbonate
BENTONE GEL® YVS V         Mineral Oil, Disteardimonium Hectorite, SD Alcohol Denat

BENTONE GEL® VS-5V         Cyclopentasiloxane, Disteardimonium Hectorite, SD Alcohol Denat
BENTONE GEL® VS-5PC V      Cyclopentasiloxane, Disteardimonium Hectorite, Propylene Carbonate
BENTONE GEL® VS-IPM V      Cyclopentasiloxane, lsopropyl Myristate, Disteardimonium Hectorite, SD Alcohol Denat

    Some of the products described within this brochure may not be available in all countries.
    Please check local availability with your ELEMENTIS Specialties sales office or distributor.
    Above list is a product guideline.
    BENTONE® EW, BENTONE® 27 V and BENTONE® 38 V are also available as irradiated grades for controlled mircobial content.
    Tailor-made products are available on request.

                                                                                                                                                                    UV actives enhancement

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            BENTONE GEL® VS-5PC V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    BENTONE GEL® VS/IPM V
                                                                                                                    Thermostable rheology

                                                                                                                                                                                                                                                                                                                                                                          BENTONE GEL® GTCC V
                                                                                                                                            Skin feel improvement

                                                                                                                                                                                                                                                                                     BENTONE GEL® SS71 V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              BENTONE GEL® OMS V
                                                                                                                                                                                                                                                                                                                                BENTONE GEL® DOA V

                                                                                                                                                                                                                                                                                                           BENTONE GEL® CAO V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      BENTONE GEL® VS-5 V
                                                                                                                                                                                                                                                                                                                                                                                                BENTONE GEL® HSO V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             BENTONE GEL® PTM V
                                                                                                                                                                                                                                                                                                                                                     BENTONE GEL® EUG V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       BENTONE GEL® PTIS V
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         BENTONE GEL® MIO V
                                                                                                                                                                                                                                                                                                                                                                                                                                          BENTONE GEL® IPM V
                                                                                                                                                                                                                                                                                                                                                                                                                     BENTONE GEL® IHD V

                                                                                                                                                                                                                                                                                                                                                                                                                                                               BENTONE GEL® ISD V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    BENTONE GEL® LOI V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   BENTONE GEL® OP V

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  BENTONE GEL® TN V
                                                                                                                                                                                                                                        BENTONE® 27 V

                                                                                                                                                                                                                                                        BENTONE® 38 V
                                                                                                                                                                                             BENTONE® MA

                                                                                                                                                                                                           BENTONE® EW
Rheological Additives

                                                                                                                                                                                                                         BENTONE® LT

                                                                                                                                                                                                                                                                        THIXCIN® R
for Cosmetics


 Highly recommended                 Recommended                    Properties imparted by                                                                                                    Aqueous-phase                             Non-aqueous-phase
                                                                   Applications ELEMENTIS Specialties                                                                                        Thickeners                                Thickeners
                                         Applications              products

  Antiperspirant Aerosol

  Deodorant      Roll-on

  Eye Cosmetics Shadow             Solvent-borne
                 Mascara           Solvent-borne

  Lip Products   Lipstick
                 Gloss             Roll-on

  Make-up        Blushers & Foundations

  Pressed Powders

  Skin Care      Creams-O/W
                 Creams-cold process
                 Hand cleansers

  Sun Care       Creams-O/W
                 Covert UV protection
                 Sunblock sticks

  Hair Care      Creams & Dressings

  Nail Polish

Sample formulation guides are available upon request
Before using any of our products please consult our Safety Data Sheets.

The information in this publication is, to the best of our knowledge,
true and accurate, but since the conditions of use are beyond our control,
no warranty is given or to be implied in respect of such information.
In every case, caution must be exercised to avoid violation or infringement
of statutory obligations and any rights belonging to a third party.
We are, at all time, willing to study customers’ specific outlets involving
our products in order to enable their most effective use.

                               Local representative

       ELEMENTIS Specialties
       Consumer Products
EUROPE Pegasuspark
       De Kleetlaan 12 A, bus 3
       B-1831 Diegem, Belgium
       Tel: +32 2 790 76 00
       Fax: +32 2 790 76 60

          Technical Centre
          ELEMENTIS GmbH
          Stolberger Strasse 370
          50933 Cologne
          Tel: +49 (0)221 485 2900
          Fax: +49 (0)221 485 2910

U.S.      P.O. Box 700 - Hightstown
          NJ 08520 - USA
          Tel: +1 609 443 2500 -
          Fax: +1 609 443 2422

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                                                          pu r e i n co sme t i cs