Release Coatsby

Jimmy Lampley

April, 08

Definition of Release Coat

What is a “release coat?”…..A

coat/coating that will relieve,

liberate, release, or free (as from

restraint) when desired/ required.

Release Coat Schematic

Release Coat

Substrate: Treated(Corona/chemical/primer)

Roll of tape Adhesive

Types of Adhesive

Hot melt

Natural Rubber

SIS, SBS

Acrylate

Others

Substrates

Films: PE, PP, PET, PVC, Acetate,

Perforated PE, Nonwoven

PET

Paper

Foil

Cloth: Plain, PE coated

Release Coats Types

Silicone

Non-silicone

Non-Silicone

WATER

Polyurethane

Urethane-Acrylic

Fluoro-polymer

PET/acrylic

Vinylacetate/Acrylic

Polysaccharide

SOLVENT

PVODC

PVSC

Polyethylenimine

Octadecyl Carbamate

(PEIODC)

Types of Release Coat

Type Acrylate Carbamate Silicone

Release

Level

1.0-1.5N/c 0.1-0.7N/c 0.01-0.1N/c

9-21 oz/in 1-6.5 oz/in 0.1-1 oz/in

Chemical

Name Fluorochemical PVODC Silicone

Types of Application

Engraved Cylinder (rotogravure)

Meyer Rod

Reverse Doctor Blade

Flexo

Need treatment (corona/chemical/primer)

Curing/Drying

Must dry web of solvent or water

Reach a temperature to remove fully the

solvent or water

Most release coats must also reach a specific

temperature to set, or film form

Web temperature/not air temperature

Assure the drying oven is free of obstructions

Film Forming Temperatures

Release Coat Temp., C Temp., F

Polyurethane 100 212

Ure-Acrylic Dry of water Dry of water

PET/Acrylic 100 212

Vinylacetate/acrylic 145 300

Polysaccharid Dry of water Dry of water

Film Forming Temperatures

Release Coat Temp., C Temp., F

Fluorpolymer, RA-110W 138 280

Fluorpolymer, RA-120W Dry of water Dry of water

PVODC 80-92 176-196

PVSC >80 >176

PEIODC Approx. 90 Approx. 190

General Properties of Release Coats

Liquid vs Powder

Water-blended vs Solvent-blended

A specific level of release, i.e. N/cm or Oz/in

Any FDA requirements

Long shelf life

Aging at elevated temperature & humidity

Chemistries

� PVODC

� PVSC

� PEIODC

Carbamate Release Coat Chemistry

Polyvinyl

Alcohol

Octadecyl

Isocyanate

O

H

Polyvinyl

Octadecyl Carbamate

CH2–CH–CH2–CH n

O–C–N–C18H35

H

+ C18H35N=C=OCH2–CH

OHn

OH

Carbamate Release Coat Chemistry

CH2–CH

OHn

+C18H37N=C=O

Polyvinyl

Alcohol

Octadecyl Isocyanate

Hexadecylisocyanate

CH2–CH–CH2–CH n

O–C–N–C18/16H35

HO

H

Polyvinyl

Stearyl Carbamate

OH

C16H37N=C=O

Carbamate Release Coat Chemistry

[H2N-(CH2–CH2N)x

CH2CH2NH2

+ C18H37N=C=O

Poly-Ethylenimine

Octadecyl IsocyanatePolyethylenimine

Octadecyl Carbamate

-(CH2CH2NH)y]

Pyridine

(C19H37NOC2H5N)X

(CH2-CH2N)n

PV

SC

PV

OD

C

PE

IOD

CSolubility

Melt Point

Anchorage

Film Forming Temp

Per

form

an

ce D

iffe

ren

ces

Per

form

an

ce D

iffe

ren

ces

PV

SC

PV

OD

C

PE

IOD

CSolubility

Melt Point

Anchorage

Film Forming Temp

Cloud Point vs. Solvent

0.3 0.5 0.7 1 1.5

100% Toluene 15% Toluene/85% Heptane

Tem

pera

ture

Release Coat Solution % Solids

% M

ax

imu

mR

elease

0%

20%

40%

60%

80%

100%

0.1 0.2 0.5 1 1.5 2 3

% Solids Release Coat

Proper Film Forming Temperature Reached

Release Coat Weight vs.% Maximum Release

Coat Weight vs. Maximum Release

0

20

40

60

80

100

0.1 0.2 0.5 1 1.5 2 3

Proper Film Forming Temperature NOT Reached

% M

axim

um

Relea

se

% Solids Release Coat

Release Coat Use Questions

Oven Drying Capabilites (What web temp.

can be obtained?)

Recirculation equipment

Temperature requirements

Printable or not (What kinds of inks or with

pencil/pen?)

Foaming issues (with water based)

Water-Based Release Coat

Preferred Emulsion

Polymer system

R

RR

R

R

R

Water-Based Release Coat

Relative Release Values

0

100

200

300

400

500

600

700

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Relative Amount of Release

Pu

ll S

tren

gth

Valu

e

A ll S ilic o ne Vinyla c e ta te / a c rylic Ure tha ne -A c rylic A c rylic

Water-Based Release Coat

Relative Release Values

0

100

200

300

400

500

600

700

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Relative Amount of Release

Pu

ll S

tre

ng

th V

alu

e

Vinyla c e ta te / a c rylic Ure tha ne -A c rylic

Escoat WFX 120

Escoat WPM80

RA-130W