Cooling water reuse is frequently limited by a ceilingon the amount of tolerable silica in the recirculationwater. Normally, if silica levels exceed about 180 ppmSiO2, severe scaling can occur on heat transfer sur-faces. Moreover, the scale that forms is frequently dif-ficult or impossible to remove by conventionalmeans. ACUMER 5000 silica control polymer hasnow raised that ceiling to at least 300 ppm SiO2,

proven by exacting pilot studies and field trials,allowing for greater water reuse than ever before.

ACUMER 5000 polymer prevents silica-based scale for-mation by dispersing colloidal silica and by preventingmagnesium silicate scale formation at the heat trans-fer surfaces. The unique features of ACUMER 5000polymer in the treatment of silica limited coolingwater are presented below.

© 2005 Rohm and Haas Company

ACUMER™WATER TREATMENT POLYMERS

ACUMER™ 5000 Multipolymer for Silica and Magnesium Silicate Scale Control

Feature Your Benefit Your Customer's Benefitas a Service Company

Maximum silica Increased cycles of concentration Increased water reuse. Reductiondispersancy and in silica-limited water. Reduced in chemical use. Maintenance ofmagnesium silicate blowdown. Maintenance of clean process efficacy.scale inhibition. heat transfer surfaces.

Superior dispersant Complete fouling control with a Less risk of fouling due to changingfor particulates. single dispersant. Less inventory conditions.

required.

Effective corrosion No special formulating requirements. Longer plant lifetime.control when used with conventionalcorrosion inhibitors.

Chemically and Usable in single-package formulation. Simplified feed and control.thermally stable.

PHYSICAL PROPERTIES

The typical physical properties of ACUMER 5000 poly-mer are listed in Table 1.

TABLE 1

TYPICAL PHYSICAL PROPERTIES(these do not constitute specifications)

Molecular Weight 5000

Total Solids, % 44.5 to 45.5

Active Solids, % 42

pH 2.1 to 2.6

Brookfield Viscosity, cp 700 max.

Specific Gravity 1.2

Bulk Density, lb/gal (g/cc) 10 (1.19)

Lb (Kg) of 100% NaOH toneutralize 1 lb (kg) of polymer 0.131

FORMATION OF SILICA-BASED SCALE

Silica forms particles with different structures depend-ing upon the pH, presence of other ions and processby which the particles are formed. The three mainforms of silica encountered in cooling water are:

• Molybdate-reactive silica: frequently referred to asdissolved silica.

• Colloidal silica: polymerized silica particles of 0.1micron or less.

• Silicate scale: primarily magnesium silicate, butmay also be iron or calcium silicate.

– 2 –

Colloidal silica, which forms when the solubility levelof silica is exceeded, is difficult to measure under fieldconditions, and a total silica mass balance cannot beachieved with a simple field test. The most effectivemethod of determining total silica is described in“Standard Methods for the Examination of Water andWastewater”, 17th edition (Method 4500-SiC). A sim-pler method that converts other forms of silica tomolybdate-reactive silica is described in Rohm andHaas Technical Bulletin FC-267, “ACUMER TST

sm,

Total Silica Test for High-Silica Waters”.

As the colloidal silica passes into the Nernst diffusionlayer at the heat transfer surface, it dissolves andacquires a negative (anionic) charge. Polyvalentcations, especially magnesium, tend to react with theseanionic colloidal particles effectively “gluing” themtogether and ultimately forming a hard, glassy magne-sium silicate scale.

Figure 1 shows how colloidal silica can dissolve toform silicate in the high temperature/high pH envi-ronment near a corroding cathodic surface where dis-solved oxygen is reduced to hydroxide ions. Thesefreshly formed silicate anions, added to the dissolvedsilica already present, can then form magnesium sili-cate scale (MgSiO3). In addition, colloidal silicaalone can coprecipitate with magnesium hydroxide toform a scale of magnesium silicate having non-stoi-chiometric ratios of magnesium to silicate.

Mg

Ca

Mg

Mg

Mg

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

FeFe

MgMg

Ca

Mg Mg

Mg

Mg

MgMg

Mg

Mg

Mg

Mg

Mg

Mg

Mg

CaMg

Mg

MgMgMg

Mg

Mg

Mg

Mg

OH

HO

HO

HO

HO

HO

HO

OH

OH

OH

OH

OH-

OHFe+3

Fe+3

Fe+2

Fe0 Mild Steel Surface

Anodic Area Cathodic Area

Bulk Water pH 8-9

~ 5 - 10 °C Higher Than Bulk

Composite Particle Mg/Ca/Fe/Silica

Nernst Diffusion Layer pH ~ 10

HO SiOSi Si SiO O

SiO

O OSiO

O

OO

OO

SiOSiOSi

OSiSi

SiO

O

O

O

O

OO

OOO

OOH

OHHO

HOSiO

OSi

• • • • • • • • • • • • •

0.1

Mic

ron

Max

imum

MgSiO3 Scale

OH

– 3 –

FIGURE 1. MAGNESIUM SILICATE SCALE FORMATION

– 4 –

Mechanism for Controlling Silica

The remarkable properties of ACUMER 5000 polymerderive in large part from its three distinctive function-alities. The weak acid (carboxylate) group provides ameans of attaching the polymer to metal ions in solu-tion and to the surfaces of particles or crystals. Thisenables the polymer to act as a dispersant to preventagglomeration and deposit formation as well as stabiliz-ing contaminants. The strong acid (sulfonate) con-tributes to this process by increasing the solubility andcharge density of the polymer which enhances electro-static repulsion of particles.

What sets ACUMER 5000 polymer apart, however, is aunique third set of functionalities, based on balancedhydrophilicity and lipophilicity (hydrophobicity)1.Where the other functionalities operate primarilythrough charge-transfer, this so-called HLB functional-ity promotes physical adsorption on the surfaces ofcontaminant particles especially at higher tempera-tures. By promoting adsorption, this third type offunctionality also contributes to the strength of theenergy barrier (or the net repulsive force) created bythe polymer around the silica particle.

ACUMER 5000 polymer adsorbed on the colloid sur-faces provides an energy barrier that prevents precipi-tation and agglomeration. Moreover, even if the silicaparticles precipitate, they are spaced too far apart formagnesium or redissolved silicate anions to bind themtogether. As a result, the scale formed by these parti-cles will be powdery and, thus, easier to remove.

For additional information on these mechanismsplease request the following reprints:

Hann, W. M. and Robertson, S.T. , “Control of Ironand Silica with Polymeric Dispersants”, IWC Paper No.90-29 (1990).

Hann, W. M., Robertson, S.T. and Bardsley, J.H.,“Recent Experience in Controlling Silica andMagnesium Silicate Deposits with PolymericDispersants”, IWC Paper No.93-59 (1993).

1The idea of enhancing adsorption by balancinghydrophilic and lipophilic moieties is borrowed from sur-factant chemists who use the term HLB (hydrophile/lipophile balance) to describe surfactant solubility andadsorption characteristics. Acumer 5000 polymer does notactually have surfacant-like properties, but it behaves in ananalogous way.

MAGNESIUM SILICATE SCALE PREVENTION WITH ACUMER 5000 POLYMER

ACUMER 5000 Polymer Action inRecirculating Water

Photomicrographs using cross-polarized lenses canbe used to study crystal structures. Figure 3 shows thedispersed silica using ACUMER 5000 polymer in therecirculating water versus agglomerated silica parti-cles in Figure 2 without polymer.

FIGURE 2.DRIED FILM OF AGGLOMERATED SILICA PARTICLES WITHOUT POLYMER AT pH 9

FIGURE 3.DRIED FILM OF DISPERSED SILICA PARTICLES WITH ACUMER 5000

POLYMER AT pH 9

Scale has large well-defined crystals typical of those foundon cooler surfaces in cooling towers.

Smaller dispersed “crystals” of colloidal silica.

PERFORMANCE OF ACUMER 5000 POLYMER

Accelerated Pilot Cooling Tower Tests

A series of 3-day pilot cooling tower (PCT) tests wererun to compare the dispersing efficiency ofACUMER 5000 polymer with that of conventionalproducts. The water chemistry and operating para-meters of the PCT in these studies are shown inTables 2 and 3.

The treatment formulation used to evaluate polymerefficacy consisted of 2 ppm tolyltriazole (TTA), 10 ppmactive polymer, and a 1/1 blend of 2-phosphonobu-tane-1,2,4-tricarboxylic acid (PBTC) and 1-hydrox-yethylidene-1,1-diphosphonic acid (HEDP) to give 5 ppm total active phosphonate. At start-up, the for-mulation was fed into the system at three times thenormal strength to compensate for the high concen-trations of silica, calcium and magnesium.

– 5 –

FIGURE 4.DRIED FILM OF MAGNESIUM SILICATE SCALE WITHOUT POLYMER PRESENT

AT pH 10

FIGURE 5.DRIED FILM UNDER SAME CONDITIONS

AS IN FIGURE 4, BUT WITHACUMER 5000 POLYMER PRESENT

Crystals are smaller but more numerous than in Figure 2,probably due to the presence of many small “magnesium sil-icate” particles.

Crystals are very small and sparse due to polymer inhibi-tion of magnesium silicate formation which seeds scale for-mation.

ACUMER 5000 Polymer Action at HeatTransfer Surface

ACUMER 5000 silica control polymer also preventsformation of magnesium silicate under the condi-tions found near a heat transfer surface, as shown inFigures 4 and 5.

TABLE 2 - MAKEUP WATER CHEMISTRY

Si, as SiO2 50 ppm

Ca, as CaCO3 60 ppm

Mg, as CaCO3 90 ppm

M-Alkalinity, as CaCO3 100 ppm

Fe+3, as Fe 0.05 ppm

TABLE 3 - AVERAGE OPERATING CONDITIONS

pH 9.0 ± 0.2

Cycles of Concentration 4.5(start-up)

Cycles of Concentration 6.8 to 7.5( after 3 days)

Heat Flux 31,520 W/m2

Skin Temperature 105-120°F (41-49°C)

Bulk Water Temperature 100°F (38°C)

– 6 –

In these accelerated tests, water passed over a seriesof four heat transfer rods in succession. Scaleformed on all four rods, with each developing morescale than its immediate predecessor. This progres-sive deposition was caused by the water becominghotter as it passed over the rods in succession. As thewater temperature rose, the tendency for deposits toform increased. In repeat tests, the amount of scalefluctuated dramatically when the polymer was anineffective scale inhibitor.

Photographs of the heat transfer rods during trialruns are shown in Figures 6 through 8. Each pictureshows the second heater in the series after two daysof the three-day experiment.

TABLE 4 - ACCELERATED PILOT COOLINGTOWER TEST RESULTS

Dispersant Polymer Scale Formation, mg(total from 4 heat transfer rods)

ACUMER 5000 850

Polymaleic Acid >2,500

Commercial silica control polymer >2,500

ACUMER 5000 polymer shows only a light dusting ofscale (Figure 6), considerably better than the otherpolymers tested (Figures 7 and 8). Within the limits ofexperimental error, the scale compositions obtainedwith all tests were approximately the same, >80% mag-nesium silicate (Table 5).

TABLE 5 - SCALE COMPOSITION (%) ACCELERATED PCT TESTS

Dispersant Polymaleic ACUMER 5000Acid POLYMER

Scale Component

Ca, as CaCO3 7.9 6.8

Mg, as CaCO3 52.2 50.8

Si, as SiO2 34.0 37.2

Fe, Fe2O3 0.4 2.6

P, as phosphonate* 5.5 3.1

Crystalline form amorphous amorphous

*expressed as 1/1 blend of HEDP/PBTC

FIGURE 6. HEATTRANSFER ROD AFTER 2 DAYS—ACUMER 5000 POLYMER

– 7 –

FIGURE 8. HEAT TRANSFER ROD AFTER 2 DAYS—COMMERCIAL SILICA CONTROL POLYMER

FIGURE 7. HEAT TRANSFER ROD AFTER 2 DAYS—POLYMALEIC ACID

Long-Term Pilot Cooling Tests

ACUMER 5000 polymer was compared to the twopolymers from the previous trials in longer tests;1) to determine whether concentrating the water

too rapidly gave an artificial negative effect,

2) to analyze scale that might form in the coolerparts of the PCT, and

3) to measure the impact of the polymer on corrosion.

These products were evaluated in the same waterunder the same conditions employed in the accelerat-ed PCT tests (Tables 2 and 3); only the cycling rate andstart-up conditions were different. In the long-term

trials, the water was started at 3 cycles of concentration(COC), using 2.5 times the normal treatment level,and then maintained at 5.5 COC (275 ppm SiO2) forfour days to allow any silicate salts or silica to form,grow and precipitate. The water was then concentrat-ed further to between 7.2 and 7.5 cycles of concentra-tion over the next nine days of the test to reach a theo-retical concentration of between 360 and 375 ppmSiO2 (50 ppm X 7.5). This quantity is approximatelydouble the recommended maximum for cooling water.The results of these tests are given in Table 6.

– 8 –

TABLE 6 – SCALE AND CORROSION ANALYSES LONG-TERM PILOT COOLING TOWER TESTS

Dispersant Polymaleic Commercial Silica ACUMERAcid Control Polymer 5000 Polymer

Total deposit weight, mg 1578.0 835.0 146.0Corrosion rate, mpy 5.4 5.3 1.1

Approximate scale cold heat cold heat cold heatcomposition, %* side exchanger side exchanger side exchanger

Si 25.1 52.0 0 47.5 0 60.4Ca 6.5 16.1 1.1 16.5 1.5 16.8Fe 47.5 17.9 98.9 27.6 98.5 10.3P 7.4 6.5 0 4.3 0 9.1Zn 0.4 2.8 0 0.3 0 0.4S 10.5 1.0 0 0.9 0 0.3Trace elements 2.6 3.7 0 2.9 0 0.7

*X-Ray fluorescence, excluding magnesiumNote: cold side temperature = 102°F (39°C); heat exchanger temperature = 120°F (49°C)

The results indicate that under the test conditions, ACUMER 5000 silica control polymer yields 10 timesless silica-based scale than conventional polymaleic acid chemistry and 5 to 6 times less scale than thecommercial silica control polymer. Moreover, the corrosion rate with ACUMER 5000 polymer is muchlower than with the two other polymers. The large difference in corrosion rates may be due to under-deposit corrosion occurring with the less effective polymers.

FIELD PERFORMANCE

The benefits of ACUMER 5000 polymer have been substantiated by its performance in four field situ-ations. In each instance, operators of the different facilities faced the problem of processing waterthat contained high silica levels and all overcame their difficulties by using ACUMER 5000 polymerin their cooling water treatment program.

Chiller System Achieves 80% Increase in COC Plus On-Line Cleaning

System Two 250-ton cooling water units with a recirculation rate of 580 gpm were usedDescription: to cool a high school. The units were treated with a chromate program until 1990. In

March of 1990, the chromate treatment was replaced with molybdate/zinc/phosphonate to comply with regulations against chromate. Deposits were con-trolled using 7-8 ppm active ACUMER 2000 copolymer. The pH of the system wasmaintained at 7.5 - 8.5.

Problem: Total hardness of the makeup water was typically about 140 ppm, with a Ca/Mg ratioof about 1/1. The makeup water typically had about 45 ppm SiO2, and the systemcould only achieve about 2.5 cycles of concentration using the molybdate/phospho-nate/zinc copolymer treatment. The condenser was opened in 1991 and found tohave light scale containing about 25% silica with most of the balance being ironoxide.

Solution: In one of the chiller systems, the copolymer was replaced with an equal concentrationof ACUMER 5000 polymer and blowdown was reduced; all other variables remainedthe same. The other chiller system was maintained with the program containingACUMER 2000 copolymer.

– 9 –

Results: The system treated with ACUMER 5000 polymer achieved more than 4.5 cycles of con-centration with no silica drop-out. Early in this trial, the chemical feed was stoppedaccidentally; a subsequent drop in recirculating water SiO2 levels suggests that somescaling probably occurred. When the chemical feed was re-established, SiO2 levelstemporarily increased to higher than expected levels, which leads to the conclusionthat the ACUMER 5000 polymer had removed some of the scale. This also suggeststhat the dispersing action of the polymer, even when underfed, resulted in the forma-tion of a powdery scale rather than the expected glassy magnesium silicate. The pow-dery nature of the scale would explain its apparent on-line removal. Data showed thatover 200 ppm SiO2 had been attained in the recirculating water.

Winery Increases Silica in Cooling Water Past Vintage Levels of 150 ppm SiO2

System A northern California vineyard operates two 560-ton evaporative condensers using Descripion: makeup water1 with high silica levels of 92 ppm SiO2. The cooling water system has a

capacity of 18 gallons per minute with water temperatures ranging between 75°F(24°C) and 85°F (29°C).

Problem: Initially, a stabilized phosphate program containing HEDP, phosphoric acid, tolyltriazoleand an acrylate-type polymer was used. Scale formed on the evaporative condenserswhen silica levels exceeded 150 ppm SiO2 in the recirculating water. This deposit wasfound to contain high levels of silicon and magnesium.

Results: Our customer replaced the existing polymer in his formulation with ACUMER 5000 polymer. This formulation was dosed into the system to maintain 13ppm residual orthophosphate and 10-15 ppm active ACUMER 5000 polymer in therecirculating water. The recirculating water contains 400 ppm M-Alkalinity and had apH between 8.5 and 8.7. The customer was able to increase cooling water cycles from1.6 to 3 COC allowing up to 276 ppm SiO2 in the system.

Thorough visual inspections, after 2 and 5 months, condenser tubes were free of scale.By switching to ACUMER 5000 polymer, this customer was able to cut his chemicalusage by almost half and save 4 million gallons of water per year.

1 Make-up water analysis: pH 7.8, 138 ppm T-Alkalinity, 92 ppm SiO2, 35 ppm Ca as CaCO3, 11 ppm Mg,7.4 ppm SO4, 18 ppm Cl, <0.1 ppm Fe, <0.3 ppm Mn, 270 ppm TDS.

Cooling System Doubles COC in San Joaquin Valley, California

System Two evaporative condenser towers rated at 500 tons were used to cool a large computerDescription: computer facility. One tower was always kept as a backup to ensure continuous opera-

tion. The evaporative condensers consist of rows of tubes on the inside of the tower.The tower water cascades downward to directly contact the condenser tubes leaving ascale deposit if the water significantly exceeds the normal operating levels of about180 ppm SiO2 and about 480 ppm (maximum) M-alkalinity. The original treatmentused HEDP, benzotriazole and polymaleic acid with a supplemental feed of poly-acrylic acid.

Problem: The makeup water typically had 90-110 ppm SiO2, allowing only about 2 cycles of con-centration. Due to severe drought conditions in this area for the previous 5 years,water was not readily available and had to be reused to the maximum extent possible.

Solution: In 1991, the polymaleic acid and polyacrylic acid scale inhibitors used in the old treat-ment were replaced with an equal weight of ACUMER 5000 polymer. The treatmentwas fed to maintain the same levels as before, but the bleedoff was reduced.

Results: With ACUMER 5000 polymer, the system maintained up to about 4 cycles of concen-tration without scale or corrosion. Recirculation water has up to 300 ppm total silicaand about 650 ppm M-alkalinity (maximum). Benefits of the reduction in bleedoffinclude:

• A calculated 30% reduction in water usage under typical conditions.• A calculated 30% reduction in chemical usage.• An increase in holding time which allows the biocide to work more

effectively (since the makeup water has a high organism count).

Scale Problem Eliminated at Ice-Making Plant

System An ice-making plant with a refrigeration capacity of 270 tons had a history of Description: scale problems, especially on the condenser coils. Silica levels in the makeup water

were 46 ppm SiO2. System temperature ranged between 83°F (28°C) and 91°F(33°C).

Problem: The water was treated with an all-organic program which left heavy deposits of silica. Athorough cleaning with ammonium bifluoride and hydrochloric acid was performed inthe summer of 1992 to remove the heavy deposits. Between August and November of1992, the COC were maintained at low levels (less than 2) to prevent silica scale. Underthese conditions, CaCO3 still formed on the condenser coils, with head pressure on thecondenser side measuring approximately 230 psi.

Solution: ACUMER 5000 polymer was added to the system to maintain 15 ppm active polymer inthe recirculationg water, and COC were gradually increased to 6 to 9.

Results: By February of 1993, head pressure had dropped to the lowest level, 215 psi, indicat-ing no scale. Theoretical silica levels approached 400 ppm SiO2. Ten months afterchanging the formulation to one containing ACUMER 5000 polymer, the plant con-tinued to operate without problems.

OTHER APPLICATIONS

BoilersThe superior hydrothermal stability of ACUMER 5000 polymer enables its use for controlling magnesiumsilicate scale in boilers operating up to about 600 psig (42 kg/cm2). Above 600 psig, it is recommendedthat the silica be removed from the feedwater by external treatment such as ion exchange.

Reverse OsmosisThe ability of ACUMER 5000 polymer to disperse colloidal silica as well as other particulates makes it suit-able in formulations for fouling prevention in RO membranes used to treat high-silica water.

– 10 –

Water Analysis: Cycles of (at steady state) Makeup Recirculating Concentration

pH 7.8-8.1 8.9-9.0 —Conductivity, µmho 330-360 1000-1030 2.9M-Alkalinity, as CaCO3 154-180 536-540 3.2Ca, as CaCO3 60-80 236-264 3.6Mg, as CaCO3 56-80 260-268 3.9Silica, as SiO2 60-70 265-300 4.2

– 11 –

TOXICITY

Toxicity data on ACUMER 5000 silica control polymer are presented in Table 7.

SAFE HANDLING INFORMATION

Caution: For Industrial Use Only! Keep Out of Reach of Children! Wear chemical splash goggles and impervious gloves when handling. An approved respirator, suitable for the concentrations encountered, should be worn.

FIRST AID INFORMATIONSkin Contact Wash affected skin area thoroughly with soap and water. Consult a physician if irritation

persists.

Eye Contact Flush eye immediately with plenty of water for at least 15 minutes. Consult a physi-cian if irritation persists.

Inhalation Move victim to fresh air.

Ingestion If victim is conscious, dilute product by giving 2 glasses of water to drink and then call aphysician. If victim is unconscious, call a physician immediately. Never give an uncon-scious person anything to drink.

MATERIAL SAFETY DATA SHEETS

Rohm and Haas Company maintains Material Safety Data Sheets (MSDS) on all of its products.These contain important information that you may need to protect your employees and customersagainst any known health and safety hazards associated with our products. We recommend youobtain copies of MSDS for our products from your local Rohm and Haas technical representative orthe Rohm and Haas Company. In addition, we recommend you obtain copies of MSDS from yoursuppliers of other raw materials used with our product.

Under the OSHA Hazard Communication Standard, workers must have access to and understandMSDS on all hazardous substances to which they are exposed. Thus, it is important that appropriatetraining and information be provided to all employees and that MSDS be available on any hazardousproducts in their workplace.

Rohm and Haas Company sends MSDS on non-OSHA hazardous as well as OSHA-hazardous prod-ucts to both “bill-to” and “ship-to” locations of all our customers upon initial shipment (includingsamples) of all of our products. Updated MSDS are sent upon revision to all customers of record. Inaddition, MSDS are sent annually to all customers of record.

TABLE 7

ANIMAL TOXICITY

Acute Oral (LD50), rats >5 g/kgAcute Dermal (LD50), rabbits >2 g/kg Eye Irritation, rabbits Inconsequential irritationSkin Irritation, rabbits Practically non-irritating

ENVIRONMENTAL TOXICITY

Algae, 72-hour EC50 72.4 mg/lDaphnia magna, 48-hour EC50 1040 mg/lSalmo gairdneri, 96-hour LC50 1100 mg/l(Rainbow trout)

FC-199b(A4) October 2005 Printed in U.S.A.

THE AMERICAS

Corporate HeadquartersRohm and Haas Company100 Independence Mall WestPhiladelphia, PA 19106Phone:1-800-223-3897Fax: 610-437-5212

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ASIA/ PACIFIC

Australia/ New ZealandPhone: 61-3-92724222Fax: 61-3-92724211

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IndiaPhone: 91-11-464 7570 Fax: 91-11- 464 7683

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ACUMER is a trademark of Rohm and Haas Company, or of its subsidiaries or affiliates. The Company's policy is toregister its trademarks where products designated thereby are marketed by the Company, its subsidiaries or affiliates.

These suggestions and data are based on information we believe to be reliable.They are offered in good faith, but without guarantee, as conditionsand methods of use of our products are beyond our control. We recommend that the prospective user determine the suitability of our materials andsuggestions before adopting them on a commercial scale.

Suggestions for use of our products or the inclusion of descriptive material from patents and the citation of specific patents in this publication shouldnot be understood as recommending the use of our products in violation of any patent of the Rohm and Haas Company.

For additional information, a sample, a Material Safety Data Sheet or to have a technical representative call forthe nearest Rohm and Haas Office.

Internet Address:http://www.acumer.com or www.rohmhaas.com