By Shrikant Athavale Presentation No : A.012.A Latest Developments in NR Latex PSA

3 5/16/2019

Harrisons Malayalam Ltd. And Prathith Consultants

Background Natural Rubber Natural Rubber is a very important Polymer used in the Manufacture of Specialty Pressure Sensitive Adhesive’s meant for a variety of PSA Tapes PSA Tapes, for specific Applications like Electrical Insulation  Electrical Insulation  Flexo Stereo Mounting  Surface Protection  Repositionable  Cold Storage Packaging  Low or No Noise

solvent borne, solvent borne technology,has lot many concerns / limitations

Natural Rubber The conventional method of producing Natural Rubber Based, Pressure Sensitive Adhesive’s solvent borne, even today is through, solvent borne technology, even today

Some of them are Fire Hazard Fire Hazard Health Hazard Health Hazard Air Pollution / VOC Concerns Air Pollution / VOC Concerns Heavy Energy Cost ( Electricity ) Heavy Energy Cost ( Electricity ) Heavy Installation Cost Heavy Installation Cost ( Plant & Machinery ) ( Plant & Machinery ) Process Limitation Process Limitation

Health Hazard We are all aware of The fact that inhaling of solvent vapors, is how dangerous

Air Pollution / VOC Concerns The solvents vapors Pollute the air to a greatest extent

For producing solvent borne PS Adhesive’s, We need Rubber Mixing Mill or Kneader Sigma Mixer Rubber mill photo sigma photo

Rubber mill photo sigma photo

Heavy Installation Cost ( Plant & Machinery )

Process Limitation For most of the specialty PSA tapes, ( with solvent borne technology) Chemical, priming essential. Chemical, priming, prior to Adhesive coating is essential. Corona Tr cannot be used Mechanical surface modifiers like, Corona Treater, etc, cannot be used online

all these draw backs, prompted us to work on a alternative technology, that will be safe, cost effective And this initiated our Research & Development on, water borne technology, using Natural Rubber latex

These challenges prompted us to think of specialty additives, especially if we had to handle water borne we got in touch with, the manufacturers of many such additives.

WETTING Wetting is the ability of a liquid to mantain contact with a solid surface. Wettability is the degree of wetting Wetting agents = additives necessary to modify the surface tension of a water based product. WETTING AGENT 62 WETTING AGENT 75 WETTING AGENT IF Poor wetting Medium wetting Good wetting

WETTING ISSUES GOOD WETTING Side wetting issue Fish eyes

WETTING ISSUES Mainly caused by insufficient substrate wetting. Reason: the surface tension of the liquid is higher than that of the substrate and no spreading takes place on its surface. Solution: add a wetting agent. Take care not to exceed in its level, otherwise you solve the wetting issue and you cause a FOAM one! An excess of wetting agent will not lead to the resolution of the problem. It must be added under stirring. Coat the product after 24 h from wetting agent addiction

FOAM in WATER BASED PRODUCTS It can be a big issue! Foam can be originated in the production step or during coating The defect can be eliminated with a suitable defoamer. ICHEMCO suggests DEFOAMER FL1 CONC, based on mineral oil and DEFOAMER FL 9, based on organomodified siloxanes.

Using a defoamer Ichemco formulates its water based products with suitable levels of defoamers, to prevent foam formation both in production and in the coating step. The level of defoamer must be well calibrated, because an excess of this additive may cause serious wetting problems. The defoamer must be added under stirring

Testing a defoamer Material: water based product – defoamer – high speed mixer (eg Hamilton Beach stirrer, max speed rpm) – graduated class cylinder Procedure: stir for 1 min at high speed a suitable quantity of water based product + defoamer. Measure the volume of 50 g of stirred product (V1). Check the volume after hours Evaluate the speed at which the foam is absorbed in the product Check the wettability, to evaluate if there is an excess of defoamer

Testing a defoamer Immediately after stirring After 1 hour

THICKENING AGENTS Thickening agents are substances which increase the viscosity of a solution or liquid/solid mixture without substantially modifying its other properties. ICHEMCO offers the following thickeners, to be used in waterborne products: THICKENER SL 6103 THICKENER NL THICKENER PU 3 Details in Technical Data Sheets and in the catalogue

USING A THICKENER Add the product slowly and under stirring. The thickening effect is not immediate, so we recommend to add the thickening agent in small doses. Especially with THICKENER SL 6103, pH should be monitored. The product itself is acidic, viscosity will increase upon neutralization. Attention to lumps!

I must Thank all of you for your valuable time Today.

A Presentation on " A case study of New product Developments "

Water Borne Pressure sensitive adhesive can be compounded with Resin dispersions, a suitable wetting agent, Rheology modifier, Defoamer and a external cross linking agent, to optimize the properties like Peel adhesion, Rolling ball Tack and Shear resistance.

Background A ) WB Adhesive for HvAc Insulation Tapes Formulate a Acrylic Adhesive WB exclusively for products meant for Air Conditioning and Ducting Industry A study of different Resin Dispersion in Water Based PSA To ascertain maximum level of resin dispersion loading To ascertain a right grade of dispersion to achieve a balance of peel adhesion and shear property. To strike a balance of peel and shear properties with help of cross link agent added externally keeping water based acrylic adhesive, a surfactant and a external cross linking agent levels constant Various resin dispersions were compounded at different levels. The formulations were compared in terms of peel and shear strength with help of graphs

Basic Formulation

Resin Dispersions are Low molecular weight tackifier resin particles dispersed in an aqueous medium with the aid of a surfactant Tackifier Resin used are based on Hydrocarbon Resin  C5  C5/C9  Rosin Ester  Hybrid ( Hydrocarbon Resin + Rosin Ester )

Coating Parameters Adhesive Dry wt. : gsm Coating method : Gravure Transfer Curing Temperature : 120 deg C Line Speed : 25 mtrs / min.

Testing For Peel Adhesion Test, Galvanized Steel plates and Aluminum Plates were used The shear strength was also conducted on Galvanized Steel plates and Aluminum Plates The shear strength was conducted at 40 deg c ( Room Temperature ) and at 56 % Relative Humidity.

PSA Products for Thermal Insulation

Water Based PSA Specifications

Surfactant solvent free wetting agent with low foaming tendency specifications

Suitable Curing Agent :

Resin dispersion - A Type : Pentaerythritol Rosin esters Specifications

Resin dispersion – B Type : stabilized rosin ester Specifications

Resin dispersion - C Type : stabilized rosin ester Specifications

Experiment 01

Experiment 02

Experiment 03

Experiment 04

Peel Strength properties for experiment 01

Shear properties for experiment 01

Peel strength properties for experiment 02

Shear properties for experiment 02

Peel strength properties for experiment 03

Shear properties for experiment 03

Peel strength properties for experiment 04

Shear properties for experiment 04

Summery PEEL

Top Side is Release Coated with WB, Release Coat

CARPET PROTECTION FLOOR PROTECTION ACP / METAL PROTECTION Top Side is Release Coated,