Transferable maskants suitable for chemical processing
In one aspect, the present disclosure provides a polymer film with a low glass transition temperature. In one embodiment, when in contact with a metal substrate, the polymer film adheres to the metal substrate under heating and/or mechanical pressure. In one embodiment, the polymer film comprises a butadiene copolymer and a butylene polymer. In another aspect, the present disclosure further provides a method of masking a metal substrate using the polymer film. In yet another aspect, the present disclosure provides a method of chemically or electrochemically processing a metal substrate that is masked with the polymer film.
1 . A polymer film comprising a copolymer comprising a blend of styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene-styrene (SEPS) having a glass transition temperature of about −150° C. to about 150° C. and a butylene polymer having a glass transition temperature of about −90° C. to −40° C., wherein the copolymer and butylene polymer are oriented such that the polymer film has a first microstructure and, upon contacting the polymer film with a metal substrate under elevated temperature and/or mechanical pressure, the polymer film has a second microstructure with increased adhesion to the metal substrate, wherein the polymer film comprises about 75% to about 95% by weight of the copolymer and about 5.0% to about 25.0% by weight of the butylene polymer.
2 . The polymer film of claim 1 , wherein the film is chemically resistant to acids and bases.
3 . The polymer film of claim 1 , wherein the blend of SEBS and SEPS has a w/w ratio of about 7:1 to about 10:1.
4 . The polymer film of claim 1 , wherein the blend of SEBS and SEPS has a first glass transition temperature of about −50° C. to about −20° C. and a second glass transition temperature of about 90° C. to about 115° C.
5 . The polymer film of claim 1 , wherein the butylene polymer is polyisobutylene.
6 . The polymer film of claim 1 , further comprising an aromatic hydrocarbon resin, an inorganic filler, an antioxidant, or a combination thereof.
7 . The polymer film of claim 6 , wherein the aromatic hydrocarbon resin is a C9 resin, the filler is an inorganic mineral oxide or an inorganic carbon, and/or the antioxidant is a hindered phenolic compound or dilauryl thiodipropionate.
8 . The polymer film of claim 7 , wherein the filler is selected from a silicate, talc, a feldspar, a chlorate, alumina, titania, carbon black, nanostructured carbon, and combinations thereof.
9 . A method of making a polymer film, the method comprising:
(i) loading a solution comprising a copolymer comprising a blend of styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene-styrene (SEPS) having a glass transition temperature of about −150° C. to about 150° C. and a butylene polymer having a glass transition temperature of about −90° C. to −40° C. into compounding machinery; and
(ii) extruding the solution from the compounding machinery to form a first polymer film of claim 1 .
10 . A method of making a polymer film, the method comprising:
(i) depositing a solution comprising a copolymer comprising a blend of styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene-styrene (SEPS) having a glass transition temperature of about −150° C. to about 150° C. and a butylene polymer having a glass transition temperature of about −90° C. to −40° C. onto a support; and
(ii) evaporating the solvent to form a first polymer film of claim 1 .
11 . A method of making a polymer film, the method comprising:
(i) loading a solvent-free composition comprising a copolymer comprising a blend of styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene-styrene (SEPS) having a glass transition temperature of about −150° C. to about 150° C. and a butylene polymer having a glass transition temperature of about −90° C. to −40° C. into compounding machinery; and
(ii) extruding the composition from the compounding machinery to form a first polymer film of claim 1 .
12 . A method of masking a metal substrate, the method comprising:
covering a top surface of the metal substrate with a first polymer film of claim 1 such that the first polymer film is in contact with the top surface of the metal substrate; and
heating and/or applying mechanical pressure to the first polymer film, resulting in adhesion of the first polymer film to the top surface of the metal substrate.
13 . A masked metal substrate made by the method of claim 12 .
14 . A method of chemically processing a metal substrate, comprising:
chemical milling, electroless plating, chemical surface treatment, chemical vapor deposition, or evaporative coating a metal substrate masked with the polymer film of claim 1 .
15 . A method of electrochemically processing a metal substrate, comprising:
anodizing, electrochemical polishing, plating, electrostatic coating, or electrofinishing a metal substrate masked with the polymer film of claim 1 .
16 . A metal substrate comprising an adhered maskant, wherein:
the maskant comprises the polymer film of claim 1 .
17 . The polymer film of claim 1 , wherein the polymer film is free-standing.
18 . The polymer film of claim 1 , wherein the tensile strength of the polymer film is about 650 psi to about 750 psi.
19 . The polymer film of claim 1 , wherein the polymer film having the second microstructure has a peel adhesion to the metal substrate of about 2 oz/in to about 35 oz/in.