Engineered Cellulose Fibers

Adhesive & Sealants

Properly formulated Properly formulated InterfibeInterfibecellulose fibers are one of the cellulose fibers are one of the most most cost effectivecost effective and uniqueand uniquefillers and fillers and thixotropesthixotropes available to available to the Adhesive and Sealant the Adhesive and Sealant industryindustry

GelGel--CelCel W90 in epoxy W90 in epoxy adhesivesadhesives

Dr. Dave Dunn, March 2006Dr. Dave Dunn, March 2006

·· Former VP & Director of R&D and New Business Former VP & Director of R&D and New Business Development, Loctite Corporation Development, Loctite Corporation

·· Managed New Business Development and R&D for all Managed New Business Development and R&D for all LoctiteLoctite’’s automotive and consumer business in the USs automotive and consumer business in the US

·· Member of the Editorial Advisory Board of Adhesives and Member of the Editorial Advisory Board of Adhesives and Sealants Industry Magazine and writes monthly Q&A column Sealants Industry Magazine and writes monthly Q&A column entitled entitled ““Ask Dr. DaveAsk Dr. Dave””

·· Recently acted as historical consultant and onRecently acted as historical consultant and on--screen screen presenter for the History Channel TV program presenter for the History Channel TV program ““Modern Modern Marvels Marvels –– GlueGlue””

Dr. Dave DunnDr. Dave Dunn

Epoxy adhesivesEpoxy adhesives

Epoxy adhesives are widely used in industrial, Epoxy adhesives are widely used in industrial, automotive, construction and consumer automotive, construction and consumer markets.markets.

Consumption of two component epoxies in the Consumption of two component epoxies in the US is over 30 million lbsUS is over 30 million lbs

Epoxy resin for basic properties

MIX

Diluents and Additives for fine-tuning

Hardener for specific properties

ComponentsComponentsof Epoxyof Epoxyadhesiveadhesive

Mix 2 componentsMix 2 components

In practice a typical twoIn practice a typical two--component epoxy component epoxy adhesive often comprises:adhesive often comprises:

ExamplesExamples

Epoxy resinEpoxy resin EponEpon 828, DER 331828, DER 331

HardenerHardener DEH 20, DEH 20, CapcureCapcure 33--800 800

VersamidsVersamids, GPM, GPM--800800

FillersFillers Talc, Ca carbonate,Talc, Ca carbonate,

barytesbarytes

AcceleratorsAccelerators VersaminesVersamines

Reactive diluent Glycidyl ethersReactive diluent Glycidyl ethers

Toughening agents CTBN rubberToughening agents CTBN rubber

ThixotropesThixotropes Usually fumed silicaUsually fumed silica

ComponentsComponentsof Epoxyof Epoxyadhesiveadhesive

Examples Examples –– epoxy adhesivesepoxy adhesives

Five Minute Consumer adhesiveFive Minute Consumer adhesive

ResinResin PercentPercent Mixed 1:1 withMixed 1:1 with HardenerHardener PercentPercent

DER 331 epoxyDER 331 epoxy 7878 PolymercaptanPolymercaptan 9090

DER 732 epoxyDER 732 epoxy 2020 AncamineAncamine KK--6464 88

Fumed silicaFumed silica 22 Fumed silicaFumed silica 2 2

Five Minute Metallic PasteFive Minute Metallic Paste

ResinResin PercentPercent Mixed 1:1 withMixed 1:1 with HardenerHardener PercentPercent

DER 331 epoxyDER 331 epoxy 4545 Polymercaptan Polymercaptan 3535

BarytesBarytes 2020 DEHDEH--2020 88

Ca carbonate Ca carbonate 2020 Weston PTPWeston PTP 22

Iron oxideIron oxide 1414 BarytesBarytes 1010

Fumed silicaFumed silica 11 KaolinKaolin 66

Ca carbonateCa carbonate 3535

TiOTiO22 33

Fumed silicaFumed silica 11

ThixotropesThixotropes for epoxiesfor epoxies

Fumed silicas:Fumed silicas:HydrophilicHydrophilic HydrophobicHydrophobicCabosilCabosil M5M5 CabosilCabosil TSTS--720720AerosilAerosil 200200 AerosilAerosil 202202

ThixatrolThixatrol ––castor oil derivative castor oil derivative -- requires heat and shear for requires heat and shear for activation.activation.

OrganoOrgano clays clays ––require polar require polar additveadditve. Sometimes cause . Sometimes cause crystallizationcrystallization

Kevlar pulp Kevlar pulp –– very expensivevery expensive

Interfibe cellulose fibersInterfibe cellulose fibers

ThixotropesThixotropes for epoxiesfor epoxies

The low cost hydrophilic fumed silicas like The low cost hydrophilic fumed silicas like CabosilCabosil M5 and M5 and AerosilAerosil 200 are rarely used with 200 are rarely used with new epoxy adhesive formulations these days new epoxy adhesive formulations these days because they tend to lose viscosity on aging and because they tend to lose viscosity on aging and most people are using expensive treated most people are using expensive treated hydrophobic silicas like hydrophobic silicas like AerosilAerosil 202 or 202 or CabosilCabosilTSTS--720. 720.

Comments from manufacturersComments from manufacturersWhy do you use Why do you use thixotropesthixotropes in yourin youradhesives?adhesives?

•• ““Need predictable stable viscosityNeed predictable stable viscosity””•• ““Need sag resistance in some industrial Need sag resistance in some industrial

productsproducts””•• ““ We want antiWe want anti--settling in filled productssettling in filled products•• ““We need to get the resin and hardener to We need to get the resin and hardener to

look and feel the same to get the best mixing. look and feel the same to get the best mixing. Also need to have good thixotropy to flow Also need to have good thixotropy to flow well onto the surfaces but then thicken up so well onto the surfaces but then thicken up so we donwe don’’t get squeezet get squeeze--out from the bondout from the bond””

Comments from manufacturersComments from manufacturers

How satisfied are you with the performanceHow satisfied are you with the performanceof your current fumed silica?of your current fumed silica?

Very satisfied Very satisfied 14%14%Somewhat satisfiedSomewhat satisfied 86%86%UnhappyUnhappy 00

Comments from manufacturersComments from manufacturers

Are there any negatives associated withAre there any negatives associated withusing your current fumed silica?using your current fumed silica?

HandleabilityHandleability :: Dust is major problem Dust is major problem –– all all respondents say thisrespondents say this

Cost:Cost: Pay $2Pay $2--3/lb for hydrophilic, $53/lb for hydrophilic, $5--6/lb 6/lb for hydrophobic gradesfor hydrophobic grades

Comments from manufacturersComments from manufacturers

Other comments:Other comments:

““Viscosity sometimes increases over timeViscosity sometimes increases over time””

““M5 is used in old products where we have noM5 is used in old products where we have noproblems. In products or products where there areproblems. In products or products where there areviscosity problems we use TS720 and also for newviscosity problems we use TS720 and also for newproducts.products.””

““M5 doesnM5 doesn’’t maintain viscosity on aging. If you overt maintain viscosity on aging. If you over--shear the shear the fumed silicas into epoxies, it takes a lot of time for viscosityfumed silicas into epoxies, it takes a lot of time for viscosity totostabilize (stabilize (ieie. thicken) so there is a temptation to correct low . thicken) so there is a temptation to correct low viscosity batches by adding more fumed silica but this causesviscosity batches by adding more fumed silica but this causeshigh viscosity problems in the future on shelf aginghigh viscosity problems in the future on shelf aging””

Comments from manufacturersComments from manufacturers

Other comments:Other comments:

““Fumed silica not nearly as good as asbestos butFumed silica not nearly as good as asbestos butnot as dangerous either!not as dangerous either!””

Comparison of W90 and Comparison of W90 and CabosilCabosilTSTS--720 in epoxies720 in epoxies

Two systems studied:Two systems studied:

1.1. In base epoxy resin In base epoxy resin EponEpon 828828

1.1. In filled In filled EponEpon 828 828 –– 30% calcium carbonate30% calcium carbonate

Unfilled systems in Unfilled systems in EponEpon 828828

ThixotropesThixotropes CabosilCabosil TSTS--720 and 720 and InterfibeInterfibeTMTM W90W90were added to base resin and mixed with high were added to base resin and mixed with high shear for 15 minutesshear for 15 minutes

Initial viscosity in Epon 828

57000

84000

20000

33000

124000

56000

0

20000

40000

60000

80000

100000

120000

140000

1 2 3Loading %

Visc

osity

cps

W90

TS-720

Cabosil TS720 room temp in Epon 828

0

10000

20000

30000

40000

50000

60000

initial after 2 weeks after 4 weeks

Visc

osity

cps

1%

3%

5%

4 WEEKS AGING4 WEEKS AGING

W90 room temp in Epon 828

0

50000

100000

150000

200000

250000

300000

initial after 2 weeks after 4 weeks

Visc

osity

cps

1%

3%

5%

4 WEEKS AGING4 WEEKS AGING

Filled systems in Filled systems in EponEpon 828828

ThixotropesThixotropes CabosilCabosil TSTS--720 and 720 and InterfibeInterfibeTMTM W90W90were added to were added to EponEpon 828 and mixed with high shear828 and mixed with high shearfor 20 for 20 mins.Thenmins.Then OmyacarbOmyacarb UF added and mixed forUF added and mixed fora further 40 a further 40 minsmins.).)

Initial viscosity in filled Epon 828

94000

276000

1,600,000

8800066000

222000

56000360000

100000

200000

300000

400000

500000

0% 0.5% 1% 2% 3%

Thixotrope Loading %

Visc

osity

cps

TS720

W90

Cabosil TS720 in filled Epon 828

0

500000

1000000

1500000

2000000

Initial After 4 weeks

Visc

osity

cps

Filler only

0.5%

1%

2%

4 WEEKS AGING4 WEEKS AGING

Cabosil TS720 in filled Epon 828

0

500000

1000000

1500000

2000000

Initial After 4 weeks After 19 weeks

Visc

osity

cps

2%

1%

0.5%

Filler only

19 WEEKS AGING19 WEEKS AGING

Cabosil TS720 in filled Epon 828

0

200000

400000

600000

800000

Initial After 4 weeks After 19 weeks

Visc

osity

cps

1%

0.5%

Filler only

19 WEEKS AGING19 WEEKS AGING

Interfibe W90 in filled Epon 828

0

50000

100000

150000

200000

250000

Initial After 4 weeks

Visc

osity

cps

3%

2%

1%0.5%

Filler only

4 WEEKS AGING4 WEEKS AGING

Interfibe W90 in filled Epon 828

0

50000

100000

150000

200000

250000

300000

Initial After 4 weeks After 19 weeks

Visc

osity

cps

3%

2%

1%0.5%

Filler only

19 WEEKS AGING19 WEEKS AGING

•• CabosilCabosil TSTS--720 is a widely used, but not perfect 720 is a widely used, but not perfect thixotropethixotrope. In unfilled epoxy resin, viscosity . In unfilled epoxy resin, viscosity decreases with timedecreases with time

•• InterfibeInterfibeTMTM W90 is much more effective than W90 is much more effective than hydrophobic fumed silica at thickening unfilled hydrophobic fumed silica at thickening unfilled epoxy resins epoxy resins

ConclusionsConclusions

•• In filled systems, In filled systems, CabosilCabosil TSTS--720 720 is an effective is an effective thickener but viscosity becomes very sensitive to thickener but viscosity becomes very sensitive to loading at loadings over 1%loading at loadings over 1%

•• InterfibeInterfibeTMTM W90 is not as efficient in thickening W90 is not as efficient in thickening filled systems but is much more controllable than filled systems but is much more controllable than fumed silica at loadings over 1%fumed silica at loadings over 1%

•• Both Both thixotropesthixotropes show increases in viscosity on show increases in viscosity on agingaging

•• InterfibeInterfibeTMTM W90 is much easier to handle than W90 is much easier to handle than fumed silica fumed silica ––no dust and incorporates very no dust and incorporates very easilyeasily

ConclusionsConclusions