A presentation based on UF resins, which is very common and a few basic concepts on colorants, for which I really tried hard to get some info while preparing this for my academic purpose..So I would like to share this with a hope that atleast one person will benefit from it..

1. UREA FORMALDEHYDE RESIN

2. RESINS
 Resin is a solid or highly viscous substance, which
are typically convertible into polymers.
 They can be plant derived ( e.g. Amber ,Balsam) or
of synthetic origin (e.g. Silicone resins).
 They are often mixtures of organic compounds.

3. AMINO RESINS
 Amino resins are a class of thermosetting synthetic
resins.
 They are formed by the copolymerization of amines
or amides with aldehydes.
 Often used to modify the properties of other
materials.
 These are added during the processing of
automobile tyres to improve the bonding of rubber
to tyre cord, paper to improve the tear strength etc.
 The two important types of amino resins are the
urea-formaldehyde resin and the melamine-
formaldehyde resin ,of urea resin comprises about
80% of the amino resins produced worldwide.

4. UREA-FORMALDEHYDE RESIN
 First synthesized by Hozler in 1884.
 Also known as urea- methanal resin.
 Non-transparent thermosetting resin , made from
urea and formaldehyde heated in the presence of a
base such as ammonia or pyridine.

5. SYNTHESIS
 The synthesis of the urea-formaldehyde resin takes
place in two stages.
 In the first stage, urea is hydroxymethylolated by
the addition of formaldehyde to the amino groups.
 This is a series of reactions which can lead to the
formation of mono-, di-, and trimethylolureas.
 The second stage consists of the condensation of
the methylolureas to low molecular weight
polymers.

7. PROPERTIES
 Very high tensile strength.
 It has the property of flexural modulus.
 It has the capacity of low-water absorption.
 High heat distortion temperature.
 High surface hardness.
 It has high volume resistance.
 It can be elongated at break.
 It possess the property of mould shrinkage.

8. USES
 Proven performance, cost effectiveness and
versatility have made UF resins widely applicable.
 They are used in decorative laminates, textiles,
paper, foundry sand molds, wrinkle resistant
fabrics, cotton blends, rayon etc.
 It is also used to glue wood together.
 Extensively used in the production of electrical
appliances casing
( e.g. Desk lamps ).
 Chosen as an adhesive because of its property of
high reactivity.
 Used in the agricultural field as a controlled release
source of nitrogen fertilizer.

9.  Used in the production of composite panel
products such as medium density fibreboard and
particleboard.
 They are stable, fast curing and highly
customizable making them an excellent choice for
applications such as wet laid fibreglass mat, air
filtration, wood composites, coated and bonded
abrasives etc.

10. UREA-FORMALDEHYDE RESIN
MACHINERY

12. COLORANTS

13. COLORANTS
• A Colorant is something added to something else to
cause a change in color.
• Colorants can be dyes, pigments, inks, paints,
biological pigments, coloured chemicals , food
colourings etc.

15. Why Polymeric Colorants ?
 The search for more readily available sources of
coloration over the last century led to the
development of synthetic pigments and dyes.
 Both dyes and pigments are powerful colourants.
 The basic difference between them is that dyes get
dissolved in the substrate, while pigments tend to
leave residues.
 Polymeric colorants were introduced as an alternative
to these classical methods of coloration since they
possess certain limitations.

16. Limitations Of Classical Colorants
 Dyes possess certain deficiencies associated with
their migration, sublimation, solid nature, price and
toxicity.
 Similarly disadvantages of pigments are their
insolubility, solid nature, abrasiveness and reduced
efficiency of light absorption.
 As an alternative to all these possibilities polymer
colorants were introduced.

17. POLYMERIC COLORANTS
 Possible combinations of a polymeric colorant can be
a pigment - polymer
a dye - polymer
a pigment - polymer-dye combination
a dye - polymer-pigment combination
a dispersant - polymer/pigment/dye
 Polymers containing reactive groups such as
anhydrides, carboxylic acids, sulfonic acids, amines,
alcohols etc are suitable for binding dyes or pigments.
 Examples of such polymers includes maleic
anhydride copolymers, acrylic copolymers,
methacrylic copolymers etc.

18. DYE ATTACHMENT
 A Polymeric colorant can be a dye covalently attached
to a polymer.
 Suitable dyes can have an active group which can be
reacted to form bonds with a particular polymer to
form a polymer-dye colorant.
 Dyes having active groups such as hydroxy, amine,
carboxylic etc can readily form covalent bonds with
suitable polymers. ( e. g. acid dyes, phthalocyanin
dyes etc )
 The reactive and active groups can be present either
in the polymer or in the dye.
 The extent of attachment of dye molecules to polymer
chain vary depending on the reaction coditions, dye
and the polymer.

19.  A polymer can also have more than one type of dye
attached to it.
 It can be done simultaneously with the addition of the
first dye or in subsequent steps.
 It can have a colour similar or different from the first
dye.
 Such additional dyes can be used to affect any
number of properties such as dispersion stability, Ph,
light fastness etc.

20. PIGMENT ATTACHMENT
 Many commonly known pigments can be covalently
attached with polymers to form polymer colorants.
 Various pigments can be functionalized with a suitable
chemical moiety which can be directly attached to the
polymer or can be done with suitable linking groups.
 Common examples of such groups are diazonium salt
reaction products, nucleophilic groups etc.
 Suitable pigments can be black pigments, white
pigments, cyan pigments etc.
 A pigment can also be attached to a polymer-dye
combination thus enhancing the properties of the
polymer colorant.

21. ATTACHMENT OF DISPERSANTS
 A dispersant can be attached directly to a polymer, or
to a pigment/dye.
 The dye can be directly attached to the polymer for
which the reactive groups used for the dye attachment
can be useful.
 Normally a pigment is finally attached to a polymer-
dye combination already having a dispersant.
 Examples of suitable dispersants include polyalkyl
glycols, polyalkyl imines, carbohydrates, acrylates etc.

22. PROPERTIES OF POLYMERIC
COLORANTS
 Solubility, absorption, migration and viscosity of
polymer colorants are tunable.
 Non-abrasive
 They do not sublime.
 They have low toxicity.

23. MILLIKEN COLORANTS
 Milliken has produced polymeric colorants for nearly
35 years.
 Versatint colorants, Reactint colorants, Clear Tint
colorants are the most common polymer colorants
produced by milliken which are used widely.
 Versatint colorants are used to color code textile fibers
during processing .
 Reactint colorants are chromogen-bearing polyols
that covalently bind to polyurethanes to give
permanent colour.

24. 1. REACTINT
 Reactint are reactive polyurethane colorants.
 Poly urethanes are produced via the reaction of an
isocyanate and a polyol.
 Reactint colorants are liquid polyol-bound
chromophores compatible with both polyether and
polyester flexible foam systems.
 The colorants do not settle or seperate.
 They are good lubricants.

25. 2. FUGITIVE TINTS
 Fugitive tints can be modified to incorporate bright
chromogens to produce non-staining colors for marker
inks.
 For this the ink viscosity has to be low, restricting the
molecular weight.
 In lower molecular weight materials the chromogen
represents a high percentage of the polymeric colorant
and affects staining.
 For example Acid blue -9 dye used in marker inks can
be modified by varying moles of ethylene oxide.

26. POLYMERIC COLORANT APPLICATIONS
APPLICATION PERFORMANCE BENEFITS
Non-linear optics, optical data
storage
non-migration, no crystallization
or precipitation,
ease of fabrication
Photography Higher chromogen density,
non-migration. higher water
solubility
Printing Controlled melting point,
non-migration, non-staining,
compatibility with plasticizers
Bulk Coloration of polymer Solubility, low volatility, low
toxicity,
low irritation. non-extraction,
thermal
stability, high chromogen density

27. THANK YOU...