Summary Overview of Laminating Adhesive Systems

Business: Dow Performance Plastics - Adhesives and Functional Materials

Dow Performance Plastics – Adhesives and Functional Materials sells products into two markets: 

1) Flexible Laminating Adhesives for Food and Medical Packaging, and 2) Flexible Industrial 

Laminates. 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 laminating 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 based 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 coreactant polyol and solvent are added and mixed. 

The 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 passing 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. The 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). The individual components are 

heated to the desired application temperature (30 to 60oC). The individual components are 

pumped to the coating station on 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 

recommended application temperature for the specified adhesive. The application rolls reduce 

the viscosity and meter the desired amount to be applied. The mixed adhesive is applied to the 

film or foil utilizing a direct smooth roll coating technique. The coated primary film is then 
laminated 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 laminate 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 substrate to make the 

lamination. The lamination is then wound into a roll under tension to allow further curing. 

Usually the curing is done at ambient temperatures, though higher 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 potential 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

needs 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 number 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 systems 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 

foreach 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 Isocyanate Terminated Prepolymers which are commercial market by our 

business are summarized in Table 1 and lists the type of isocyanate and technology (solvent 
based, solventless application, or water based). We have provided a copy of the MSDS for each 

of these 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 Solvent 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 Aromatic 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 Solventless
Mor-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.