Summary Overview of Laminating Adhesive Systems

Business: Dow Performance Plastics

- Adhesives and Functional Materials

Dow Performance Plastics

– Adhesives and Funct i onal Materials sells products into two markets: 1) Flexible Laminating Adh e s i ves for Food and Medical Packaging, and 2) Flexible Industrial
Lamin a tes. There are three basic classes of laminating adhesives in commercial use by Dow
Performance Plastics

– Adhesives and Functional Materials utilizing isocyanate components: 1)
Solvent based two

- part polyurethane systems, 2) Solventless two

- part polyurethane systems, and 3) Water based two

- part adhesive systems.

All the adhesive systems are sold directly to converters which utilize them with traditional coating and laminati ng equipment to prepare two

- ply or multi

- ply laminates. All operations are conducted with the proper personal protective equipment for the operators and with proper/ adequate ventilation defined by the safety requirements for the industry.

The solvent b ased adhesive systems are mixed at the converter by charging the main resin component (polyester or polyester / polyol ) to a compounding tank / reservoir and diluting with Ethyl Acetate to adjust the material for proper application solids (typically 25 to 40% Wt. solids). To the diluted resin is added the isocyanate coreactant and the compounded solution is
mixed. Alternately, the main resin solution that contains the isocyanate is charged to a mixing vessel. Then the appropriate amount of the core actant polyol and solvent are added and mixed.

T he adhesive solution is pumped to the coating line and into the coating tray at the coating station; the solution can be re

- circulated back to the reservoir during and after the adhesive application. The adhesive is applied to the primary film or foil using direct or indirect gravure coating. The solvent is evaporated from the coated substrate by passi ng through heated ovens which are equipped with solvent recovery or incineration units. The coated primary substrate is then laminated to a secondary film by passing through a nip roller and the laminate is taken

- up in
a master roll of laminate stock. Th e laminate stock is cured at ambient or supra

- ambient (ca. 45oC (110oF)) conditions until fully cured.

The solventless adhesive systems are prepared as supplied by utilizing a heated meter mixing station. The isocyanate terminated prepolymer is charged to one tank (Tank A) and the polyester or polyester / polyol resin is charged to another tank (Tank B)

. T he individual components are heated to the desired application temperature ( 30 to 60oC). The individual components are pumped to the coating station o n the coater / laminating equipment with a meter / mix pump system which mixes the two components in a static mixing head at the coating station. The coating station is maintained at the application temperature by heating the application rolls to the

reco mmended application temperature for the specified adhesive. The application r o lls reduce the viscosity and meter the desired amount to be applied. T he mixed adhesive is applied to the film or foil utilizing a direct smooth roll coating technique

. The coated primary film is thenlaminated directly to the secondary film using a nip roll and taken

- up in a master roll of laminate

stock. The laminate stock is cured at ambient or supra

- ambient (ca. 45oC (110oF)) conditions until fully cured. The lami nate stock is cured with a specified tension to the master roll which does not permit the uncured adhesive to flow out of the coated laminate stock; excessive tension on the laminate stock will result in adhesive flowing out the laminate and will result in blocking of the rolls making them unusable

.
For water based adhesives, the primary resin dispersion is mixed to achieve homogeneity, and the isocyanate containing coreactant (usually aliphatic) added slowly with constant mixing. After full addition, the adhesive mixture is further mixed for a minimum of 15 minutes to fully disperse the coreactant. The adhesive is then pumped either to a reservoir or directly to a pan or feed system for gravure application to the substrate. The wet adhesive is then dried in oven(s) to remove the water. The dried adhesive is then nipped to a second su b strate to make the
lamination. The lamination is then wound int o a roll under tension to allow further curing. Usually the curing is done at ambient temperatures , though h igher temperatures may be used

. The conditions of winding and further storage of the laminate are such that no adhesive would ooze out from the edges; once the adhesive is fully cured there is no p otential for oozing or
movement of the adhesive.

The adhesive systems are provided to the converter with the proper documentation for the various components (MSDS for each component) and the mix ratio for the adhesive system , per the Technical Data Sheet ( TDS ) supplied for the adhesive system . The technical data sheet for each product documents the recommended mix ratio for the adhesive and the cure time and conditions to be employed for full cure. For food packaging applications, the adhesive system
need s to be fully cured in order that no adhesive components migrate into the food. The
adhesive materials need to be in compliance with a minimum of FDA compliance of Title 21
CFR 175.105. The degree of cure for our systems will be determined in part by the n umber of days for the laminate to develop full bond strength and performance for the application , as well as disappearance of the isocyanate . In some specific applications such as hot

- fill, pasteurization

, or retort packaging our laminates will be tested for migration of isocyanate species and /or low molecular weight (≤1000 Daltons (atomic mass units, amu)) per the requirements of FDA compliance Title 21 CFR 177.1390 or 177.1395. The flexible industrial laminating adhesives are chemically related to our food packaging adhesive s ystems and thus have comparable cure
characteristics to these systems and as such will have no residual “free” isocyanate monomers present in the fully cured system for use.

For the Isocyanate Terminated Prepolymers the level of isocyanate is specified on the MSDS
for each of these components. We utilize both aromatic and aliphatic based isocyanate materials in our product line and depending upon the specified application and end use specific materials will be employed. The Isoc yanate Terminated Prepolymers which are commercial market by our
business are summarized in Table 1 and lists the type of isocyanate and technology (solventbased , solventless application , or water based ). We have provided a copy of the MSDS for each

of t hese materials.

Table 1: Summary of Isocyanate Terminated Prepolymers

Isocyanate Terminated Prepolymer Isocyanate Type Technology Application

Coreactant F Aromatic Isocyanate Solvent Based
Coreactant CT Aromatic Isocyanate Solvent Based Adcote 518 Aromatic Isocyanate Solvent Based Adcote 522 Aromatic Isocyanate Solvent Based Adcote 527 Aromatic Isocyanate Solvent Based Adcote 331 Aromatic Isocyanate Solvent Based Adcote 530S Aromatic Isocyanate Solvent Based
Adcote 532A Aromatic Isocyanate Solvent Based Adcote 536A Aromatic Isocyanate Solvent Based Adcote 555 Aromatic Isocyanate Solvent Based Adcote 560A Aliphatic Isocyanate Solvent Based Adcote 577 Aromatic Isocyanate Solvent Based Adcote 577A Aromatic Isocyanate Solvent Based
Adcote L76X161 Aromatic Isocyanate Solvent Based
Adcote L76

- 178 Aromatic Isocyanate Solvent Based Adcote L76

- 186 Aromatic Isocyanate Solve n t Based Coreactant 9L10 Aliphatic Isocyanate Solvent Based Adcote 811B Aliphatic Isocyanate Solvent Based
CR 842B Aliphatic Isocyanate Solvent Based
CR 842D Aliphatic Isocyanate Solvent Based
CR 857 Aliphatic Isocyanate Solvent Based
CR 386 Aliphatic Isocyanate Solvent Based
Coreactant 86 Aliphatic Isocyanate Solvent Based Coreactant 9H1H A romatic Isocyanate Solvent Based
Coreactant 9L7 Aliphatic Isocyanate Solvent Based Adcote 76FS93 Aromatic Isocyanate Solvent Based

Mor

- Free ELM 415A Aromatic Isocyanate Solventless
Mor

- Free 400A Aromatic Isocyanate Solventless
Mor

- Free 403A Aromatic Isocyanate Solventless
Mor

- Free 421 Aromatic Isocyanate Solventless
Mor

- Free L75

- 149 Aromatic Isocyanate Solventless
Mor

- Free L75

- 163 Aromatic Isocyanate Solventless
Mor

- Free L75

- 164 Aromatic Isocyanate Solventless
Mor

- Free L75

- 169 Aromatic Isocyanate SolventlessMor

- Free L75

- 176 Aromatic Isocyanate Solventless

Mor

- Free L75

- 274 Aromatic Isocyanate Solventless
Mor

- Free L75

- 275 Aromatic Isocyanate Solventless
Mor

- Free 205A Aliphatic Isocyanate Solventless
Mor

- Free C

- 33 Aliphatic Isocyanate Solventless
CR 833 Aliphatic Isocyanate Solventless

CR 9

- 101 Aliphatic Isocyanate Water Based Robond CR

- 2 Aliphatic Isocyanate Water Based
CR

- 40B Aliphatic Isocyanate Water Based

The polyester, polyester

- urethane, polyester

- polyol , acrylic and latex resins contain no isocyanate components. We have not provided copies of the MSDS for these components at this time; these can be provided upon request.