Styrene Butadiene LatexSiam Synthetic Latex Co., Ltd.

Discussions:

• What is Latex?• Latex Characterization• SB Latex applications• Health hazard and safe handling information• Q&A

What is Latex?

• LATEX is a white, tacky, aqueous suspension of a hydrocarbon polymer occurring naturally in some species of trees....or made synthetically.

• made by emulsion polymerization techniques from a range of monomers (styrene, butadiene, acrylates, etc).

• low in viscosity, ~ 50% water / 50% polymer, and are easy to pour, mix and pump.

• stabilized by ionic forces of repulsion between the particles, and also by the addition of suitable surfactants.

• Latexes may be destabilized by the following: • Ions (especially multivalent cations Ca2+, Al3+) • Shear (mixing, pumping) • Freeze / Thaw• Heat

Advantages of Latex

• Low viscosity: It is an advantage to have the polymer in a liquid state for processing by the customer.

• Aqueous: Latex may be used directly in aqueous formulations. There is no organic solvent to remove (flammability, toxicity, environmental etc.)

• Unique manufacturing process: Fast reaction, good heat removal due to low viscosity.

• Polymer: A wide range of polymers are available using various combinations of monomers. eg. The dried polymer may be:

– A clear, tough, tough rubbery film, which may act as a binder in filled systems.

– A hard plastic (white powder).

– A sticky (tacky) adhesive.

S/B Latex Compositions

Compositions Function, Contribution

Styrene Hardness, strength, stiffness, good aging, high Tg polymer

Butadiene Softness, flexibility, adhesion, poor aging, low Tg polymer

Water Continuous phase for emulsion polymerizationEnhances heat removal from reaction

Surfactant Improve stability of Latex

Defoamer Control foaming tendency of latex under processing or end use conditions

Antioxidant Increase usage lifetime of product by reducing rate of oxidation (butadiene polymers)

pH control agent Control pH during polymerizationAdjust pH after polymerization to provide stripper stabilityAdjust pH for customer specification

Biocide Control bacteria in latex which feed on organics present

Typical SCG-Dow S/B Latex properties

Solids content 47 - 54 %

Specific gravity 1.01 - 1.06

pH 5 - 10

Viscosity 50 - 600 mPa.s

Surface tension 40 - 65 dynes/cm

Styrene content of polymer 40 - 60 %

Vinyl Acid content of polymer 0 - 6 %

Particle size 0.12 - 0.25 m

Latex Characterization

Solid content The water and other volatile components are evaporated to determine the non-volatile (solid) content of the latex. This 'solids content' reflects the amount of 'active' polymer, additives etc. in the latex.

Filter residue Latex residue is formed from the agglomeration of polymer particles. Latex is passed through a standard sieve, and the dried weight of latex residue per litre of latex is recorded.

Fisheye test The fisheye test is used to measure the film forming properties of the latex for coating applications. Film continuity may be affected by waxes or silicon based defoaming materials.

Particle size (Light scattering)The weighted average particle size is calculated from the measured dissymmetry of light scattering. The dissymmetry is the ratio of the intensity of light scattered at 45 degrees and 135 degrees. The particle size is expressed in angstroms.

Latex Characterization

Particle size (HDC)Hydrodynamic Chromatography (HDC) is a technique used for quantitative determination of particle size and particle size distribution in latex samples. The latex particles are separated via liquid chromatography according to their size.

Latex film propertiesAllows certain predictions as to a latexes behavior and properties in end-use applications.

Latex film properties include:

Tensile strength, Elongation to break, Young's Modulus, Swell index, Gel content, MFFT, Tg, Composition by FTIR.

MFFT Minimum film formation temperatureTemperature at which a latex will form a continuous film. Estimation of the MFFT is critical to ensure that proper processing and drying conditions are chosen for developing a latex film during end-use (eg. during drying on a paper machine).

Latex Characterization

Tg Glass transition temperature The Tg is the temperature at which an amorphous (non-crystalline) material changes from a

brittle, glassy material to a flexible, rubbery state, or vice versa.

Some end-user important properties of polymers which correlate strongly with Tg: Tensile strength, % Elongation, Flexibility ("Hand"), MFFT

VOCs Volatile organic compounds Measuring VOCs is important to ensure specifications are being met.

Determine the level of odiforous components in the latex.

Examples of VOCs that are often measured include: Styrene, 4-VCH, 4-PCH, Alkyl benzenes

Bacteria What does bacteria do to our latex? Gives a foul odor. Causes deterioration of physical

properties. Can cause residue (coagulation).

Bacteria control: Clean storage tank, clean shipping container, fast turnover.

THE DRYING PROCESS

Water evaporation: solids50-60-70%, particles getcloser together and viscosity increases.

Coalescence: solids90-95-100%, particlesforced together andcoalesce.

Film: interdiffusion,decrease in gas permeability.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

STAGE I

STAGE II

STAGE III

S/B Latex applications

• Paper coating• Carpet backing• Construction• Can sealant• Wood adhesive• Etc.

Dow Latex is modified styrene butadiene latex made by emulsion polymerization for variety applications such as paper coating, carpet backing, wood adhesive, can sealant and construction application etc.

Paper Coating: • Used as a binder for pigmented coating of paper

and paperboard for offset printing.• High wet and dry binding power• Good printability• Stiffness• Blister resistance• Fold crack minimization

Carpet backing: • Used for carpet secondary backing applications,

providing excellent adhesion when either wet or dry.

• High tuft bind• Excellent filler acceptance• Excellent mechanical stability• Low odor/Low VOCs• Contain antioxidant

Can sealant: • Used for can sealant and can seaming

compound. For food and beverage can packaging.

• Excellent wet and dry adhesion • Comply with F&DA 175.300.

Cement & Construction: • specifically designed for use in cement mortars. • Improve bonding, tensile and flexural strength• Durability• Improved water resistance• High chloride resistance

Paper Coating

Why is paper coated?

To improve the optical properties (gloss, brightness, opacity) To increase the smoothness of the surface To improve the printability To bind the pigment particles to each other and to paper we say that the binder “spot-welds” the pigment particles

Coated paper prints better

Printed Uncoated Paper Printed Coated Paper

Paper Coating Compositions

Composition Function, Contribution

Pigments: Calcium Carbonate & Clay

Fill voids and contour on the paper, make paper surface smoother, more even ink absorption

Binder (Latex / Starch) Bind pigment with the paper

Dispersant Continuous phase for emulsion polymerizationEnhances heat removal from reaction

Insolubilizer Improves water resistance of the coating (wet pick) for offset printing.

Lubricant Improves runnability, reduces dusting on calender and slitters, sheeters in finishing.

Dye adjust colour of the coated paper

OBA Optical Brightening Agent

Improves brightness of coated paper by adsorbing UV light and re-emitting it as blue light. Makes the paper look brighter and “whiter”

NaOH Adjust pH of coating color to range 8-9

Typical Paper Coating Formulation

• Coating normally produced in the mill in a batch process (kitchen)

• Paper can have 1, 2 or 3 layers of coating

• Dow supplies:– Binder– Hollow Plastic Pigment– Solid Plastic Pigment

Formulation = Coating ColorIngredient PartsCalcium Carbonate 0 – 100Kaolin Clay 0 - 100Plastic Pigments 0 - 8Total Pigments 100

Latex Binder 5 - 25Starch 4Thickeners 0.2 – 1.0Lubricants (stearate) 0.5 – 1.0OBA 0.2 – 1.5Defoamers 0.1 – 0.3Cross-linkers (UF) 0.2 – 0.5------------------------------------------------pH 8 - 9Solids 50-75%Viscosity 500-2000 mPas

Carpet Backing

Carpet Segmentation

Woven Tufted Needlefelt Tiles Auto Mats SyntheticGrass

BathroomMats

Carpet

unitarySB/EVA/PVAC

Full BathSB

One SideTML/SB

PVC/Bitumen

Rubber Crumb /PU Foam SB/PVC/PU

Natural/SyntheticLatex

unitarySB

secondarybacking

SB

FoamHSL

Ecoworx

Gel

Bathroommats

No Gel

Underlay

BACK

ING

TY

PE

PU/rubber/SB

TUFTED CARPETCONSTRUCTION

Yarn

Primarybacking

Latexcompound

Secondarybacking

Tufted carpet latex compound

Objectives:

• Good frothability and froth stability (coat weight control)• Good tuft lock (prevent tufts pulling out)• Penetrate the yarn tufts to bind the individual filaments (prevent ‘pilling’ and ‘fuzzing’)• Good secondary backing adhesion• Prevent edge fraying when the carpet is cut for installation• Good dimensional stability• Add weight• Required stiffness (‘hand’)• By addition of other additives, contribute to ignition resistance and conductivity

Carpet latex compound compositions

Composition Function, Contribution

Binder (S/B Latex) Bind yarns with backing, Handed feeling

Filler (CaCO3) Give bulk to the latex compound and reduce cost

Dispersing agent Offsets the forces of attraction between pigment particles.Reduction of energy necessary to separate pigments into discrete particles

Foaming agent Froth the compound

Foam stabilizer prevents the foam collapsing while in the foam bank

Foam stabilizer adjust colour of the coated paper

Thickener Increase the viscosity of a latex compound to prevent the filler settling. Prevents the compound from penetrating through to the face or back of the carpet.

Tufted carpet compound formulationDIRECT COAT (D/C)

TUFTED CARPETLICK APPLICATOR

Construction

Application of LMC

Deck coverings

AnticorrosiveLinings

Flooring Paving

-Bridge deck overlay-Internal and external ship-decks-Footbridge decks-Rail wagons

-Chemical or machinery plant floors-Septic tanks-Parking structures-Effluent drains

-Commercial and Industrial floors-Toilet floors, garage-Railway platform, Road

Application of LMC

IntegralWaterproofing

Repairingmaterials

Decorativecoatings

-Concrete roof-decks, render wall-Water tanks, Swimming pools-Septic tanks, Silos

-Cement stucco-like coatings-Cement filling compound-Self leveling cements

-Sprayed concrete for repair ofconcrete structures-Protective coatings for corrodedreinforcing bars

LMC Mix Design: 3-6 cm thickLMC Mix Design: 3-6 cm thick(Parts by weight)

Component Conventional concrete LMC

Cement 1.0 1.0

Sand, 2NS (<0.5 cm) 2.6 2.6

Stone, 25N (<1.2 cm) 1.75 1.75

Latex/Cement 0 0.15

Water/Cement 0.45 0.37

Water reducer * none

Air entr. agent * none

Air content 5-8% 3-7%

* vary levels

Typical Formulation of LMC

• Portland cement• Aggregate (0-12 mm)• DL470 (46% solid)• Potable water

• P/C (polymer/cement)• W/C (water/cement)

M3

400 kg1650 kg

130 kg62 kg

= 0.15= 0.33

LMC Model

1. Initial Mixing

2. Latex deposit on cement & aggregate

Unhydrated CementUnhydrated Cement

LatexLatex

AggregatesAggregates

AirAir

LMC Model3. Latex close packs around cement and aggregates, cement partially hydrated

4. Latex film encapsulates fully hydrated cement

Benefits of DL470 to concrete

• Make concrete stronger and more durable– Improve adhesion, flexural strength and tensile

strength with no loss of compressive strength

• Impermeability– Reduce penetration of moisture and corrosive

chemicals

• Abrasion resistance– High traffic area e.g. car park

Benefits of DL470 to concrete (cont’)

• Thinner overlay– Allow less material to be place to assure

protection

• Freeze/Thaw stability – Improve resistance to moisture

penetration and cracking.

• Workability– Reduce w/c ratio, leads to higher

density structure

Affect of Bridge deck corrosion

• Financial Costs• Traffic Delays• Lost Productivity• Increased Emission• Auto accident• Personal Injury

Health hazard and safe handling information

Health hazard information

• Inhalation No adverse effects are anticipated from inhalation.

• Ingestion Single dose oral toxicity is considered to be low. No hazards anticipated from swallowing small amounts incidental to normal handling operations.

• Skin Short single exposure is not likely to cause significant skin irritation. Prolonged or repeated exposure may cause skin irritation. Skin absorption is unlikely due to physical

properties.

• Eye May cause slight transient (temporary) eye irritation. Corneal injury is unlikely.

First aid measures

• Inhalation No adverse effects anticipated by this route of exposure.

• Ingestion No adverse effects anticipated by this route of exposure incidental to proper industrial handling.

• Skin Wash off in flowing water or shower.

• Eye Irrigate immediately with water for at least 5 minutes.

• First Aid Facilities An eye wash fountain and a general washing facility should be available to the work area.

• Other Information Never give fluids or induce vomiting if patient is unconscious or is having convulsions.

Fire fighting measures

• Extinguishing Media– Water fog or fine spray. Carbon dioxide. Foam. Dry chemical.

• Unusual Fire & Explosion Hazards– Will not burn until water is evaporated.

• Flammability– Non-combustible, non-flammable while an emulsion. Dried product will burn

in a similar fashion to wood.

• Hazardous Combustion Products– Upon burning, the dry product generates dense, black smoke.

Spill & Disposal

• Protect people: – Wear adequate personal protective equipment.

• Protect environment: – Keep out of sewers, storm drains, surface waters and soil.

• Clean-up: For small spills: – contain and cover with sand, sawdust or absorbent material.

• Clean-up: For large spills:

– contain and recover for disposal. If entry to drains or sewers has occurred, system may plug. Flush system with large amounts of water.

Q&A

Thank you