CA2142899A1

CA2142899A1 - Fluoroalkyl siloxane/vinyl copolymer dispersions and pressure-sensitive adhesives having improved solvent resistance prepared therefrom

Info

Publication number: CA2142899A1
Application number: CA002142899A
Authority: CA
Inventors: Ramesh C. Kumar; Albert I. Everaerts; Yvan A. Bogaert
Original assignee: Individual
Current assignee: 3M Co
Priority date: 1992-09-18
Filing date: 1993-09-16
Publication date: 1994-03-31
Also published as: DE69304203T2; EP0660863A1; EP0660863B1; JPH08501586A; US5349004A; WO1994006878A1; US5482991A; DE69304203D1

Abstract

2142899 9406878 PCTABScor01 Novel pressure-sensitive adhesives are described which show significant resistance to solvents and working fluids such as jet fuel, hydraulic fluid, de-icing fluid and the like. Adhesive compositions comprise nonaqueous dispersions of copolymers of acrylic monomers prepared in the presence of a vinyl-substituted fluoroalkyl siloxane having general formula (I) and a macromonomeric stabilizer. The adhesives prepared from the adhesive compositions exhibit excellent adhesion to glass, aluminum, and low surface-energy materials such as fluoroalkyl siloxane elastomers. The fluoroalkyl siloxane has formula (I).

Description

2 1 4 2 ~ 9 9 Pcr/US93/0~767 El~: QALKYL SILO~ElYl~L (: OPOLYME:R DISPERSIQN~
~N~ PR~;SSUR~SE:NSITIVE ~DHE~I~ES HAVING IMPROVED
SOLVENT RESISTANCE PREPARED THEREFROM

Field of the Inven~ion This invention relates to stable, fluoroalkyl siloxane/vinyl copol~n~ disp~r~io~s which provide pressure-sensitiYe adhesil.~es ha~ing improved solvent resistance especially against solvents such as gasoline, jet fuel, hydraulic fluid, and oils. The invention also relates to the solvent resis~s~t pressure-sensitive adhesives (PSAs) prepared thererrom.
: ~ 15 : ,, ' '' Acrylate pressure-sensitive adhesives are well-known. U.S.
Patent No. Re 24,906 (IJlrich), assigned to the assignee of the present casP, discloses alkyl acrylate copolymers which comprise a major amount of alkyl esters of acrylic acid, havin~ from 4 to 1~ carborl atoms and which comprise a ~; minor arnount (i.e. 3 to 12%, preferably 4 to 8%) of a polar, co~lymerizable monomer, such as acrylic acid. Such adhesives are widely popular, as they are readily ava~lablej and provide a good balanc~ of t~ck, shear, and peel properties on a variety of substrates at rela~ively low cost. However, such adhesives can experience poor solvent resistance and poor adhesion to low energy sur~aces, such as polyolefins, silicones, and fluorosili~ones.
It is well-known that the use of tackifiers in acrylic PSA
formulations enhances the adhesion of the PSAs to low ene~gy surraces.
However, this incre~se in adhesion occurs at the expense of interna~ strength.
~ need has existed for acrylic adhesives having impro~ solvent resistance, esp~cially against such fluids as gasolitle, iet fuel, hydraulic fluid, and oils. Two main approaches have been tried to achieve this goal. Qr~e approach imolved ~he modification of the acrylic polymer backbone. The other approach inYolved the combination of two elastomers in a hybrid adhesive composition.
EP 0,075,191 (1981), assigned to Da~lcin Kogyo, descr~bes a solution polymer of pentafluoropropyl acrylates which when coated on polyester yields a tape which experiences less than a 10% adhesion loss when exposed to oil, gasoline, kerosene, and water. This adhesive re~uires expensive WO 9~/06878 PcrtUs93/~8767 89g -2-fluori~at~ acrylate monomers and does not include a second elastomer as part of the composi~ion.
Fluoroelastomers have been incorporated into adhesive ,, compositions in an attempt to yield adhesives having improved solvent resistance. JP 61-31411 (198~), assigned to Suriibondo, describes a radically ;, polymerizable composition comprising (meth)acrylate or oligomer thereof, tl~ fluoroelastomer, and a curing agent. The cured composition which demonstrates improved heat-resistance and oil-resistance can be used as an ~; adhesive and a caulking material. The fluoroelastomers used are vhlylidene fluoride/hexafluoropropylene copolymers and the adhesives are ultraviolet light (UV) or anaerobically cured. No disclosure is made of fluoroalkyl siloxane elas~omers. JP 63-117085 (198%), assigned to Central Glass, discloses a tacky adhesive compnsing ~ copolymer of vinylidene fluoride and hexafluoroacetone cornbined with a copolymer of 2-e~hylhexyl acryla~e and vinyl acetate. The adhesive is purported to be weather and oil resistant. Aga~n, no fluoroalkyl siloxane elastomer was included in the composition. EP 0,390,207 ~1990), ~rl assigned to Daikin Industries, discloses a vibration damping rnaterial obtained ,~ by dissolving an amorphous fluorine-containing polymer into acnrlic monomer and polymerizing the monomer with or withou~ perrnitting the resulting polymer to form an inte~ne~rating polymer network. The composition is reporte~ to ~, ~ provide excellent damping, solvent resistance, oil resistance, and weatheAng resistance, however~ no pressure sensitive adhesive properties are taught.
A ne~d thus exists for an inexpensive pressure s~nsitive adhesive that is resistant to solven~s and adheres well to low energy surfaces, with a ,,'~,.`! 25 balance of tack, adhesion and fluld resistançe. We have disco~ered such a pressure-sensitive adhesive.

~j~ Brief D~scrip~ Q~hQ ~ny~ntion " We have discovered that ~he copolymer~ation of certain acrylic monomers with a sufficient amount of a fluoroalkyl siloxane elastomer in the presellce of a stabilizer results in a pressure sensitive adhesive composition which can be used in forming a PSA having an excellent balance of tack, adhesion, and solvent resistance. An additional benefit is _ood adhesion to unprimed fluoroalkyl siloxane elastomers.

3~ The present invention provides an adhesive composition comprising a novel stable, fluoroalkyl siloxane/vinyl nonaqueous copolymer `~` dispersion which compnses the polymerization product of a mixture comprising the ~ollowing components:
;, ~`
' wo g4/0687~ 2 1 ~ 2 8 9 9 PCI/US93tO8767 (a) about S to about 40 parts by weight of a fluoroalkyl siloxane of the formula Rl. R8 R6 R2ff i~ t S i-- ) X--s i r~5, ( I
R3 E~.9 R4 ~;
1: ~ 10 wherein:
! R9 is independent~y select~d from the group consisting of -C~I2CH2Rf and -R7, R~ is a fluoroalkyl group independently selected from the group 15 consistil~g of C~,F2m.l and C~F~n+l~ qHq~
m is an integer ranging from about 1 to about 20;
n is an integer raslging from about 1 to about 20;
q is an integer ranging from about O to about 2n;
; x is an integer of about 11 or greater;
0 the fluoroalkylsiloxane comprises 10 or greater -CH2CH2Rf grvups;
;`: the fluoroalkylsiloxane comprises at least 1 R7 group;
wherein Rl ~ R3 R4, R5, R6, and R8 are each independently 1 . . . . . .
selected from the group consisting of aL~l groups compnsing about 1 to about ~5 1~ carbon atoms, ~kyl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, and hydrogen; and R' is an organic group comprising at least two carbon atoms wherein at least 1 olefinic moiety is containe~ within R', il wherein the ratio of R' to~-CH2CH2R, is such that ~he mole 1 percenl of the olefinic rnoiety content contributed by R7 of the fluoro~kyl 30 siioxane is bet.ween about 0.1 asld about 4;
~ b3 about 60 to about 95 parts by weight of free radically polymerizable monomer, wherein the free-radically polymerizable monomer compnses: .
(i) about 1 to about 20 percent by weight of &ee 35 radically polymerizable polar monomer; and:

(ii) about 80 to abou~ 99 percent by weight of free radically polymerizable non-polar monomer;
, ~:

~ ,... . .... ...... . .... ..

WO 94~06878 2 l 4 2 g 9 ~ Pcr/U~93/08767 ^4-wherein the weight percentages of ~i) and (ii) are based upon thetotal weight of (i) plus (ii); and wherein the total weight of (a) plus (b) equals 100 parts by weight total;
(c) about 0.1 ~o about 1 part by weight of a free radical 5 initia~os based upon 100 parts by weight total of (a) plus (b);
(d) about 2 to about 10 parts by weight of a stabilizer based upon 100 parts by weight of total of (a) plus (b) wherein the stabilizer has a number average molecular weight ranging from about 8000 to about 25,000 ar d wherein the s~bilizer is sele~ted frurn the group consisting of:
(i) a copolymer comprising (A) about 40 to abou~ 60 parts by weight of monomer selected ~rom the group consisti~g of vinyl esters of C~ to C8 monocarboxylic acids and C, to C,~ alkyl (meth)acrylates, and (B~ about 60 to about 40 pa;~s by weight of monomer selæted from the group consistirlg of N-vinylpyrrolidone, acrylamide, N,N~imethylacrylamide, N-vinylcaprolactarn, and mixtures thereof, wherein the copolymer comprises 100 part~ by weight total of the monomers of (i)(A~ plus (i)(B); and (C) about 0.5 to about 5 weight percent of a chain transfer agent based upon the weight o the mono~.ne~s of (i)(A~ plus (i)(B);
(ii) a macromonoaler compnsing the reaction product of ~0 the copolymer of (d)(i), wherein the chain t~ansfer agent selected proYides the copolymer wi~h a~ least one ~unc~ional group sel~ted from the group consisting .~ of ~ , -COOH, -OH, and combinations ther~f, with an endcapping agent ~: selected from the group consisung of isoeyanatoethyl methacrylate, alpha, alpha~imethyi-meta-isopropenyl benzylisocyanate, pa~a(chloromethyl) styrene.
vinyl a~lactone, glycidyl methacrylate, and mixtures thereof. wherein at least about 95% of the functional group(s) selected from the ~roup consisting of -N~E2, -CO(:)H, ~ , and combinations thereof~ or Ihe copoiymer are reacled wi~h the end~apping agent; and (iii) mixtures thereof; and (e3 about 30 to about 95 perçent by weight of an organic j , , solvent based upon the total weight of (a) plus ~b) plus (c) plus (d) plus (e).
Also provided by the present invention are cornposiholls~ which . upon cure provide adhesives having even ~reater reiistance to jet fuel, engine oil, hydraulic fluid, brake fluid or similar matenals, wherein the compositions comprise the fluoroalkyl siloxane/viny} nonaqueous dispersions and a compatible crosslinker.
The novel fluoroalkyl siloxane/vinyl copolymer compositions of the present invention provide, upon cure, a balance of fluid resistance and !l .

2i~2899 WO 9~/06878 Pcr/US93/08767 j; 5 adhesion to glass, aluminum, polyolefins and/or fluoroalkyl siloxane elastomers.Compared to "all-acrylic" and silicone/acrylic materials known in the art, the ~ adhesives of the present invention demonstrate improved adhesion to fluorosilieone elastomeric matenaIs.
:~ S
Deoj~j~l~e InveneiQn ~ ~ r Fluoroalkyl siloxanes of Forrnula I are useful in the present invention~ R~, RZ, R3, ~, R5, R6, and R8 are each pre~rably independently ,~ selected from the group consisting of alkyl groups comprising about 1 to about ~, 6 carboll atoms, most preferably about } to about 3 carbon atoms. Such fluoroalkyl siloxane~ are preferred in that elastomers made therefrom typically pro~rid~ opumum so!vent and h~t resist~nce and low temperature flexibility?
whereas elastomers made from fluorosilicone gums comprising larger groups, 'j iOe" C4 or higher, may tend to have lower solvent and hea~ resistance and decreased low temperature flexibility. Purthermore, fluorosilicone gums having such larger groups t~pically tend to be more expensive.
` ~ R7 represents an organic group compnsing at least two, typically two to nine carbon atoms, and containing at least one olefinic moiety (i.e., R7 contains at least 1 ethylenically unsaturated functional group sueh as a ~rinyl segrnent). In reference to R', the term "olefinic moiety" refers to carbon a~omsbonded via a double bond(s) and atoms pendan~ therefrom. Exars~ples of monovalent moieties include but are not limi~ed to -CH=CH., -CH=CH-, etc.
`I 25 For exasnple9 if R' comprises -CH2-CH2CH=CH-CH2 CH-CH2 there a~e two olefinic moiedes conta~ned therein: -CHaCH- and -C~=CH2. As another example, when R' cnmprises -CH2-CH~-CH--CH~, the olefinic moiety portion is c~nside~d to be -C~=C~2. As ~nother example, whes~ R' comprises -CH~CO2CH=CH2 the olefinic moiety poriton is considered to be -CH=CH2.
J'`' 30 Preferably, the unsaturated bond is terminally-l~ted since ~erminally-located bonds typically provide for faster cure rates. Whcn R7 compnses more than ~wo car~on atoms, non-~erminally-located bonds within the group may be ~j ethylenical}y-unsaturated. However, such bonds typically tend to be lessreactive due to the relatively sterically-hindered position of such bonds.
Elastomers ~ormed ~y curing compositions containing fluoroalkyl siloxanes wherein the R7 group romprises more than nine carbon atoms may tend to have lower solvent and heat resistance.
~}i `'`1 ' ~t~

WO 94/06B78 ?, ~ 4 ~ 8 9 Pcr/uss3/o8767 The letter x represents an integer of 11 or greater, typically x represgnts an integer of about 11 to about 5500.
In order to form a copolymer useful as a fluid-resistant adhesive a fluoroalkyl siloxane of Formula I should be used wherein the fluoroalkyl S siloxane contcuns 10 or greater -CH2CH2R, groups in order to provide a distinct fluoroalkyl siloxane phase to the copolymer, preferably about 2000 to about 3500 -CH2CH2R, groups, in order to provide adequate fluid-resistance characteristics to the copolymer while improving adhesion to low-energy surfaces (such as silicones, fluoroalkyl-silicones, polyolefins, etc.).
The ratio of R' to -CH2CH2R, }s such that the mole percent of olefinic or vinyl moiety content is between about 0.1 and about 4, preferably between about 1 an~ about 2. Compositions wherein the olefinic or vinyl moiety content of the fluoroallcyl siloxane is substantially lower than these ranges ma ,r phase separate to give a smaller number of grafts resultin~ in a heterogeneous solution. Those compositions wherein the olefinic or vinyl moiety content of the fluoroallcyl siloxane is substantially higher than this range may result in crosslinking of the copolymer.
Fluoro~lkyl siloxanes useful in preparing the compositions of the present invention typically have a weight average moleclllar weight between about 200,000 and about 700,~0, preferably between about 250,000 and about 6501000~ as determined ~y gel permeation chromatography. Elastomers cured from compositions made with fluoroallcvl siloxanes having molerular wei~hts i ~ substantially below these ~anges may tend to have lower tensile strength.
Compositions may be made with fluoroalkvl siloxanes having molecular weights . 25 higher than these ranges. However, such compositions will typically have ~` higher solution viscosities, thereby tending to reduce the ease of processability and application to ~he desired substrate. Such high moie~ular weigh~
fluoroal~1 siloxanes also exhibit red~ced compatiDilily in the present ¦~ ~ formulation. The fluorine content of the fluoroalkyl siloxalles useful in the present invention is typically at least about 20 weight percent, preferably at least about 30 wei~-~t percent based upon the weight of the fluorvalkyl siloxanes. If the fl~.onne content of the fluoroalkyl siloxane is too low the ~: solvent resistance of:the resultant elastomer :may tend to be reduced, for ~:~ ins~ancP the e}astomer may tend to swell to a greater ex~ent.
~: 35 ThP num~er of olefinic moieties contained within the fluoroalkyl siloxane can vary. The weight ratio of the olefinic moieties of the fluoroalkyl siloxane to the total weight of the fluoroalkyl:siloxane typically ranges from 3~ ~

'~' WO 94/0~878 ^ Pcr/uss3/o~767 about 0.5:99.5 to about 3:97. Preferably, the weight ratio ranges from about 0.5:99.5 to about 1:99.
The fluoroalkyl siloxanes useful in the present invention can be prepared by any lalown method including, for example, those described in U.S.
Patent Nos. 4,029,629; 4,041,010; 4,529,752; 4,585,848; and 4,599,374.
Examples of fluoroalkyl siloxares useful in the present invention include but are not limit~d to the following fluoroalkyl siloxanes available from the Dow Corning Company: Silastic~ 2840, LS-2860, LS-2249U, and LS-2332U.
An example of a preferred fluoroall;yl siloxane is trifluoropropyl rnethyl ;' 10 siloxane containing 0.1 to 1.0 mole % vinyl sites (i.e., olefinic moiety content).
~ !
re~-radi~a~ly Polvmerizable Monomers Representative ex~nples of free-radically pGlymerizable nonpolar monomer~ having at least one ethylenically unsaturated polymerizable group include but are not limited to those monomers selected from the group consisting of alkyl acrylatesl preferably monofunctional unsaturated acrylate esters of primaIy or secondary alkyl alcohols, the mole~ules of which comprise from about 1 to about 14 carbon atoms, and mixtures thereof. Exarnples of ;!, sp~cific nonpolar monomers include but are not limi~ed to those selected f~om the group consisdng of isooctyl acrylate, isononyl acrylate, 2-ethylhexyl ~; acrylate, decyl acrylate, dodecyl ac~ylate, n-butyl acrylate. hexyl acryiate, mixtures thereof, and the like. Preferred nonpolar monomers include those ;I selected from the group consisting of isooctyl acrylate, butyl ac~ylate, ;' 2-ethylhexyl acrylate, ard mixtures thereof, which monomers provide the best adhesive properties~
~Rep~esentative examples of free-radically polymerizable polar monomers ha~ring at le~st one ethylenically unsa~urated polymenzable group which re copolymerizable wilh the nonpolar monomers inclu~e s~ongly polar copolymeri7~bl~ monomers including but not limited to those selected from the group consisting of acrylic acid, itaconic acid, hydroxyalkyl acrylates, '. cyanoallyl acrylates, acrylamides, and subs~ituted acrylamides7 and moderately polar copolymenzable monomers including but not limited to those selected from ~he g~up consisdng of N-vinylpyrrolidone, acrylonitrile, mixtures `~; thereof, and the like.
The preferred monomers include those selected from the group consisting of isooctyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, acrylic ~1 acid, itaconic acid, N-vinylpyrrolidone, acrylonitrile, and mixtures ~hereof.

~j . .

WO 9~/~6878 P~r/us93/0~767 Most preferably, the monomers comprise a mixture of isooctyl acrylate7 acrylic acid, and N-vinyl pyrrolidone.
The adhesive composition of the inventionl comprises about S to sl about 40 pa~s by weight fluoroalkyl siloxane and about 60 to about 9S parts by S weight free radically polymerizable monomer, preferably about 10 to about 30parts by weight fluoroalkyl siloxane and about 70 to about 90 parts by weight .I free radically polymeriz~ble monomer, and most ~re~erably about lS to about ~:! 25 parts by weight fluoroalkyl siloxane and about ~S to about 85 parts by weight free radically polymerizable monomer, ~ased upon 100 parts by weight total of fluoroalkyl siloxane and free radically polymerizable monomer.
: The free radically polymerizable monomer typically comprises about 1 to about 20 percen~ by :weight polar monomer and about 80 to about 99 percent by weight nonpol2r monomer, preferably about 5 to about 15 percen~
by weight polar monomer and ~bout ~5 to about 95 percent by weight nonpolar monomer, most preferably about 8 to about 12 percent by weight polar .1 monomer and about 85 to abou~ 92 percent by weight nonpolar monomer, based on the total weight of free radically polymerizable monomer.

'~ 55a~zQ~
A third component is a stabilizer for the nonaqueous dispersion ~i ~ oî ~he invention. The stabilizer ~ comprise a copolymer c~mpnsina a~ about 40 to about 60 parts by weight of monomer se}e~ted from the group consisting of vinyl esters Qf C, ~o C~ monocarboxylic acids and C, to C,2 alkyl `~ ~meth)acrylates, and b) about 60 to about 40 parts by weight of mono~ler selected ~rom the group consisting of N-vinylpyrrolidone, acrylamide, N,N-dimethylacrylamide, N-vinylcaprolactam. and mixtures thereof wherein the stabilIzer comprises 100 parts by weight total o~ monomer, and whereln the stabilizer has a number average molecular weight ranging f~m about 8~0 to about 25,000. Optionally, the random copolymer may be reacted with end-capping monomess (pre~erably an equimolari amount) to for~n a m~cromonomer, the end-capping monomers including but not limited to those selected from the group consisting of isocyanatoethyl methacrylate (IEM) and alpha, alpha-dimethyl^ .~propenyl benzylisocyar~te (TMI), vinyl azla~tone, para(chloromethyl) styrene, glycidyl methacrylate, and mixtures thereof through -OH, -NH~, or -COOH functionality or combinations thereof, which may be in~roduced to the copolymer tbrough a chain transfer agent. At least about 95 %
of the free hydroxyl (-OH), amine (-NH~, carboxyl ~-COOH~ groups, or combinations thereof, pre~erably at least about 98% of the free hydroxyl, .~, WC~ 94/()6878 Pcr/uS93/08767 amine, carboxyl groups, or combinations thereof, and most preferably about 100% of the free hydrnxyl, amine, carboxyl groups, or combinations thereof, of the copolymer are reacted with end-capping agent. End-capping introduces ethylenically-unsaturated free-radically polymerizable functional groups into the 5 random copolymer such that the end-capped macromonomer can be copolymerized with the fluoroal~yl siloxane and the free-radically polymerizable monomers of the present invention as descnbed above.
Preferred stabilizers include those selected from the group consisting of vinyl acetate/N-vinyl pyrrolidone copolymer endcapped with IEA and Yinyl 10 acetate/N-vinyl pyrrolidone copolymer endcapped with TMI, and mixtures thereof. Most preferably, vinyl acetate/N-vinylpyrrolidone copolyfner endcapped with isocyanatoe~hyl me~hacryla~e is selec~ed as the stabilizer due toits ease of synthesis and the facility wiih which it is copolymerized with the fluoroalkyi siioxane ard free-radically polymerizable monomers present in the 15 adhesive composition of the present invention.
The copolymer stabilizer can be prepared by combining the desired monomers, initiator (such as those discussed below), a chain trans~er agent such as -OH, -NH2, or -COOH functional chain tr~nsfer agent selected from the group consisting of chain transfer agents which provide the copolymer ~0 with -C)H functionality (e.g.9 mercaptoethanol), chain transfer agents which provide ~he copo}ymer stabilizer with -COOH funcuonalitv (e.g., mercapto acetic acid), chain transfer agents which provide the copolymer stabilizer with -~2 functionality (e.g., mercaptoamine), and mixtures thereof, and a conventional organic solvent such as e~hyl ace~ate ~and/or those discussed 25 below) in a reaction vessel. In cases where the copolymer stabilizer is not to be reacte~ Yvîth an end-capp}ng agent, a non-func~ional chain transfer agent canbe used such as isooctyl thioglyc~late, carbon te~rabromide, and the like.
Typically about 20 to about 50 pa~ by weight of monomer is used. Typi~ally about 0.5 to about 5 weight % of chain transfer agent is used based on the 30 weight of the monomer charge. Typically about 80 to about 50 parts by weight of solvent is used. PolymeIization is conducted under inert atmosphenc conditions, with agitation, for about 10 to ~ hours.
A macromonomer stabilizer can be prepared by reacting the copolymer with end-capping agent in the presence of a catalyst such as dibutyl 35 tin dilaurate. Typically about 0.03 to about 0. lS weight % of catalyst is used based on the weight of the end-capping agent. Also about 0.01 to about 0.1 weight % of a conventional antioxidant such as Irganox~ 1010 (available from Ciba-Geigy) based on the monomer charge is included. The reaction pre~erably 21428~
WV 94/06878 ~ Pcr/vss3/0~767 ;, is conducted under inert atmospheric conditions with agitation for about 1 to about S hours.
A stable nonaqueous dispersion is obtained only if a stabilizer h~ving a nunnber average molecular weight ranging from about 8,000 to about 5 25,000 is used. If the molecular weight is too high, the nonaqueous dispersioninitially formed becomes uns~ble over time and;is unusable as a coating. If the stabilizer is not added before polymenzation occurs, a separate fluoroalkyl siloxane and a separate acry}ate phase is obta~ined (i.e., a heterogeneous coating so}ution). Therefore, the stabilizer is an essential p~ of the formulation. The '1 10 stabiliær is typically included at about 2 to about 10 par~s by weight, prefe~ably `1 from abou~ 3 to about 6 paIts by weight, most preferably about 4 to about 5 .! paltS by weight, based upon 100 parts by weight total of the free-radically polymeri~able monomer plus fluoroalkyl siloxane.
! j 15 Initi~tors 3 Examples of useful free-radical initiators according to the present invention a~e detailed in Chapters 20 and ~1 of l~,facromole~ules, Vol.2, 2nd Ed., H. G. Elias, Plenum Press, 1984, New York. Useful thermal ini~iators for purposes of the present invention include, but are not limited to, those 20 selected from the group consisting of the following: a~o compounds such as 2,2'-azobis-(isobutyronitrile), dimethyl-2,-2'-azo-bis-isobu~yrate, azo-bis-(diphenyl me~hane), 4,4'-æo-bis-(4-cyanopentanoic acid); peroxides such as benzoyl peroxide, cumyl peroxide, tert-butyl peroxide, cyclohexanone peroxide, glu~ic acid peroxide, lauroyl peroxide, methyl ethyl ke~one peroxide and 25 hydrogen peroxide; hydroperoxides such as tert-bu~yl hydroperoxide and cumene hydroperoxide; pe.~cids such as peracetic acid and Derbenzoic acid.
potassium persulfate; peresters such as diisopropyl perca~onate; and mixmres thereof. Ce~ain of these initiato;s (in par~icular the peroxides, hydroperoxides, peracids, and peresters) can be indueed to decompose by addition of a suitable 30 catalyst rather than thennally; This redox method of initiation is described in ~, Chapter 20.
Useful photochemical initiators include but are not limited to those selected from the group consisting of benzoin ethers such as diethoxyacetophenone, oximino-ketones~ acylphosphine oxides, diaryl ketones 35 such as benzophenone and 2-isopropyl thioxanthone, ben~il and quinone derivates, and 3-ketocumalines as described by S.P. Pappas, J. Rad. Cur., July t ~ ~ 1 9 87, p . 6 .
,, ., ~
,.~ . .
,~2 21i2899 WO 9~/06878 ^ Pcr/us93/08767 Preferably, the initiator used comprises a thermally decomposed azo or peroxide compound for solubility re~sons and in order to control the reaction rate. Most preferably, the initiator used comprises 2,2'-a~obis-(isobutyronitrile) for re~sons of cost and appropriate d~composition5 temperature.
The adhesive composition of the invention comprises about 0.1 to about 1 pare by weight initiator, preferably about 0.2 to about 0.8 part by weight, most preferably about 0.3 to about 0.5 part by weight, based upon 100 parts by weight total of fluoroalkyl siloxane and free radically polymerizable 10 monomer.
.

An organic solvent is utilized in the polyrnerization process of the inven~ion in order to decrease the viscosity during the reaction to allow for 15 efficient stirring and heat transfer. The organic solvent used in the free radical polymerization can be any organic liquid which is essentially inert to the reactants and which will not otherwise adversely affe~t the reaction.
~; Suitable solvents include but are not limited to polar solvents such as those selected ~rom the group consisdng of esters such as ethyl acetate 20 an~ butyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, me~yl propyl ketone9 ace~one; and mixtures thereof.
Othe~ solvent systems are use~ul as well. Aliphatic and arom~tic hydroca~bons can be used, although, sometimes they lead to the precipi~a~ion of the v inyl polyrneric segment from solution. Hydrocarbon solvents may be used ~5 when admixed with other polar solvents which help control the molecular weight of the final copolymer.
The solvent utiliz~d in the fre~ radical polymenzation, may be any substance which is li4uid in a temperature range of about -lOaC to about 110C, does not ineerfere with the energy source or catalyst used to dissociate 30 the initiator~ to form free radicals, is inert to the reactants and product and will not otherwise adversely affect the reac~ion. The organic solvent selected is ;~ capable of dissolving the fluoroalkyl siloxane, monomer, stabilizer, and initiator to form a mixture. The arnount of solvent used is generally about 30 to about 95 percent by weight based on the total weight of the reactants (i.e., fluoroalkyl 35 siloxane, poiar monomer, non-polar monomer, initiator, stabilizer) plus solvent.
Preferably, the amount of solvent utilized ranges from about 40 to about 50 percent by weight, most preferably about 35 to 40 percent by weight based i; upon the tota} weight of the reactants plus solvellt in order to obtain fast .

Wo ~4/06~78 Pcr/uss3/o8767 reaction times and high molecular weight of the polymer at appropr~ate product viscosities.

M~tho~s of Pol~menz~tion S The homolytic decomposition of the initiator used in the present invention to form fsee radicals can be induced by he~t energy (thermolysis)t light engrgy (photolysis), or the ~ddition of a suitable catalyst. The decomposition rate of the initiator dur~ng thermolysis depends upon the chemical nature of the initiator, the reaction tempera~ure, and the solvent used.
The de~omposition rate of the initiator during photolysis depends mainly upon I, the chemical nature of the initiator and the intensity and wavelength of the i ~ radiation utilized.
Light energy can be supplied to induce the homolytic decomposi~ion of the initiator by rneans of visible or ultraviolet sources ;ncluding low in~ensity fluorescent black light lamps, medium pressure mercury arc lamps, and germicidal rnercury lamps. The selection of a prefe~ed light energy sourc~ will depend upon ~he chosen pholoinitator.
The decomposition of the initiator can also be accomplished by using a suitable catalyst. Cat~lyse induced initia~or decomposition involves an ele~tron ~ansfer mechanism resulting in a reduction-oxidation (redox) reaction.
Initiators such as peroxides and hydro~roxides are more s~sc~eihle ~o t~sis kind of decomposition. Catalysts useful in inducing the homolytic decomposition of ~he initiator include, but are not limi~ed to those selected from the group consis~ing of amines and met~l ions used in eombination with peroxide or hydroperoxide initiators and bisulfite or mercapto compounds used in combination with persulphate initia$~rs.
The preferred method of initiation is thermoiysis which can be readily employed ~n st~ndard react~rs. Thermolysis also provides for ease o ~7` control of the reaction rate and exotherm.;1 ! 30 The free~ dically poiymerizable monomers, the initiator, the stabilizer, the fluoroallcyl siloxane, and the solvent employed are charged intoan appropriate reaction vessel in order to form a mixture. If photolysis is conduc~ed to decompose the initiator, the reactants and any solvent employed are charged into an energy source transparent vessel and therein Y 35 subJected to ~he energy source. If the energy source is ultraviolet light radiation, a suitable ultraviolet light-transparent vessel is utilized.
If thermolysis is used to decompose the ini~ator, the reaetants and solvent employed are charged into a sui~able glass or metal reactor, and ~`1 WO 94/06878 2 1 ~ 2 8 9 9 PCI /l~S93/0$767 therein subjected to the thermal energy source. If catalysis is used to decompose the initiator, a glass or metal reactor can also be utilized.
The reaction is preferably conducted in a vessel with agitation to ~;
permit uniform exposure of the reactants to the energy source. ~hile most of S the reac~ions have been conducted by employing a batch process~ it is possibleta utili~e the same technology in a continuous polymerization operation. tl ~eaction times on the order of about 1 to about 40 hours have been found typical, depending upon the amount and type of solvent used1 the amount and type of initia~or used, temp~ratures or phololytic energy supplie~, and the nature of the free radically polymerizable monomers.

9D~Ln~
The adhesive composition of the invention can be blended with on~ or more cc~npa~ible modifiers in o~der to optimize physical proper~ies. For example, it may be desirable to include an additive selected from the group consisting of pigments, extenders, conducting material, various polymeric additives, and mixtures thereof. It is theonzed that the cnpolyrner contained inthe dispersion made in the practice of the present invention can be recovered by~`! standard pr~cedures such as evaporation of solvent, or precipitation after polymerization into water or a suitable organic solvent such as methanol, ~; ~ nexane, etc. It is theorized that s~ndard extraction techniques may also be used if desired. It is also t~eonzed that the co,?olymer may also be ~cen or inverted into a different solvent either by a solvent exchange process, e.g by adding a higher boiting solvent and then distilling out the low boiling solvent or ~; 25 by aæotropic distillation, a teehnique well known in the art.The fluid-resistant pressure-sensiliYe adhesive composi~on of the present invention may compnse the defin~d copolymer dispersion alone or may, ~,~ we ~on~e, comp~ise t}le copolymer dispersion blçnded with a compatible i homopolymer, copolymer, etc. The low percentage of fluoroalkyl siloxane polymeric segment contained in the copoiymer dispersion makes this fluoroalkyl ; siloxanelvinyl copolymer dispersion readily compatible, for purposes of blending, with other polymers whose composition is similar to the vinyl polymeric segment. In addition, there are several pairs of dissirmila~ polymers that yield compatible blends due to specific inte~actions as described by ` ~ 35 S. Krause in Po!Ymer Blends, ~cadernic Press, New York, 1978.The fluoroalkyl siloxane/vinyl copolymer dispersions of the present invention can be used for a variety of ~pplications, such as prepanng ` ~ fluid-resistant adhesives and sealants, form-in-place multipurpose gasketing .:...i 214289~
WO 94/06X78 Pcr/us93/08767 '' compounds, etc. The fluoroalkyl siloxar e/vinyl copolymer stable nonaqueous dispersions are particularly useful for making a fluid-resistant pressure-sensitive adhesive. ' A dispersion composition capable of providing a PSA having S even greater solvent resistance can be prepared by addlng a crosslinker to the dispersion. Thus, a dispersion composition capa~le of forming adhesives having even greater fluid resistance can be made by adding ~rom about 0.1% to about 0.5% by weight of a crosslinker into the stable fluoroalkyl siloxane/vinylcopolymer nonaqueous dispersion, based upon ~he percent solids (i.e., 1~ fluoroalkyl siloxane, free-radically polymenzable monomer, initiator, and stabilizer). Examples of useful crosslinkers include but are not limited to thermally-ac~iva~ed, moisture-activated, and ultraviolet radiation (UV) activated crosslinkers. Examples of thermally-activated crosslinkers include but are not limited to those selected from the group consisting of multifunctional aziridille amides such as N,N'-bis-1,2-propyleneterephthalamide, metal complexes such 'as aluminum acetylacetonate, metal ions such as Zn2+, Zr2+, and Ni2+, which can be provided in the form of soluble metal salts, asld isocyanates such as H-12MDI (4,4'-methylene-bis-[cyclohexylisocyana~e]). Examples of moisture-ac~vated crosslinkers include but are not limited to those selected from the group consisting of silanes such as trimethoxysilylpNpyl methacrylate ~ris), amino silane, epoxy silane, and mixtures ~hereof. Examples of UV-l~ activated crossiinkers include but are not limited to those selected from the group consisting of chromophore-substituted tnazines as described in U.S. Patent No. 4.330t590 (Vesley, 3M) and U.S. Patent No. 4,329,384 2S (Vesley et al., 3M), such`as 2,4-bis(tnchloromethyl)-6-(4-methoxyphenyl)-s-tnazine, 2,4-~is(tnchloromethyl)-6-(3,4-dimethoxyphenyl)-s-triazine, ~,4-bis(trichloromethyl)-6-(3,4,5-tnmethoxyphenyl)-s triazinet , 2,4-bis~tri!chl~rome!hyl)-6-~3,4-methylene~ioxyphenyl)-s-triazzn~, and 2,4-bis(trichlorome~hyl)-6-(4-methQxynaphthyl)-s-triazine, and in U.S. Patent No. 4,181,752 (Martens, 3M), e.g., 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-s-tnazine, and copolymenzable aromatic ketone monomers as desenbed in U.S. Patent No. 4,737,550 and U.S. Patent No. 4,847,137 (Kellen et al., 3M), such as 4-acryloxybenzophenone.
~; The preferred weight ratio of vinyl polymenc segment to fluoroalkyl siloxane polymeric segment of the present copolymer dispersion ranges from about 60:40 to about 95:5, in order to allow ~or a wide range of fluid-resistant performance while still maintaining good adhesion to various substrates.

W(~ 9~/06878 P~r/us93/08767 For improved fluid-resistant properties the copolymer can be crosslinked by standard methods well lcnown in the art, such as radi~tion curing(electron beam or ultraviolet light) or chemical curing.
. The above-described nonaqueous dispersion can be coated onto S subst~ates such as s}licone coated paper linPr9 polyethylene terephthalate film, fluorosilicorle backing, etc., by any conventional coating means such as Meyer rod, gravurc, ruling rnills, etc. The coated substrates are typically dried.and cured by heating to a temperature of about 65C for about lS to about 30 minutes.
Abbreviations and Tradenames ~`1 VAc :Vinyl acetate `~ ~IVP N-vinyl pyrroiidone $ l,PM liter per-minute IEM isocyanato ethyl methacrylate D}3TL Dibutyl dn dilaurate MEK Methyl ethyl ketone IOA Isooctyl acryla~e A Acrylic acid ~: Hrs Hours Alum. Aluminum FSi Fluorosilicone VAZ~64 2,~'-awbis~;so~utyronitrîle) avaiiabre rrom duPont ,,~
Irganox~ l0l0 pentaerythr~tol, tetrakis [3-(3,5-di-tert-butyl~-~:~ hvdroxyphenyl)proprionate] antioxidant, from Ciba Geigy Company LS-2860 A fluoroalkyl silicone elastomer available from Dow Coming Co. (weight average molecular weight of app~oximately 490,000, olefinic moie~y content of awu~ 0.6 mole ~0) Ex. : ~antple ' .
Te~eth~ds M~lç~lar W~i~ht Determjnation The characteriza~ion of the molecular weight distribution of the .~ polymers described herein has been by conventional gel perlr eation .: chromatogr~phy (GPC).
A Hewlett-Pac~ard Model 1084B high performance liquid ch~oma~graph equipped with Styragel~ columns was used. The system was .`;' . .:
' ~:

.
i .

!
i WO ~4/06878 2 ~ 8 ~ 9 PCr/US93/08767 4 calibrate~ using polystyrene standards. All molecular weight averages are polystyrene ~uivalent molecular weights. The molecular weight averages were calculated according to accepted prac~i~es. GPC test methods are further explained in "Modern Size Exclusion Liquid Chromatography", Practice of Gel 5 Permeation~hromatography, John Wiley, New York, 1979.
3 Peel Adhesil~n Jl (Reference: ASIM I:)3330-78 PSTC-1 (11/75)) Pe~,l adhesion is the ~orc~ r~uired to remove a coa;ea rlexibie 10 sheet material from a test panel measured at a specific angle and rate of ,~ removal. In the examples, this force is expressed in Newtons per 100 mm ~N/100 mm3 width of coated sneet. The procedure Iollowe~ is:
1. A 12.5 mm width of the coated sheet is applied to the 3 horizontal su~ace of a clean glass or aluminurn test plate with at least 12.7 15 lineal cm in firm contact. A hard rubber roller is used to apply the stnp.
2. The free end of the coated stnp is doubled back nearly touching itself so the angle of removal will be 180. The ~ree end is attached ~; to the adhesion tester scale.
;`~ 3. The gla;s test plate is clamped in the jaws of a tensile 20 testing machine which is capable of moving the plate away from the scale at a `ii constant rate of ~.3 meters per minute.
~, 4. The scale reading in Newtons is recorded as the tape is led from the glass surface. The data is reported as the range of numbers obserYed during the test.
' ~m~
The following non-limiting examples further illustra~e the present invendon. All parts, percentages, ratios, e~c. in the ex~mples ~nd the rest of the specification are by weight unless otherwise indicated.
~' 30 ; Example 1 $,~he~is of VAc/NVP_~mer Stabilizer ~, .
14.0 g NVP, 10.84 g VAc, 0.8 g mercaptoethanol, û.12 g .~ VA~O~ 64 ard 41.4 g ethyl a~etate were charged into a 130 mlO amber bot~le.
35 The resulting solution was purged with N2 for 2 minutes at the rate of 1 LPM.i~ The bottle was sealed and tumbled in a const~t temperature bath at 65C for ~` 17 hours.

~t, .i WO 9~/068782 1 4 2 8 9 9 PCI/l S93/08767 ~ ~
-17- 1.
Example 2 i~
Cappin~ Q~VAc/NVP Copolvmer with IEM to prepare 't Macromonomer Stabilizer ~
To the polymer solution obtained in Example 1, 1.2 g IEM, 0.25 ~,;
S g DE~TL and approximately 0.13 g of Irganox~ lal0 was added and the resulting solution was purged with N~ for 2 minutes at the rate of 1 LPM. The bottle was sealed ~uld tumbled in a constant temperature bath at 55C for 3 hours. IR analysis showed complete capping.

~
The fluoroalkyl siloxare LS-2860 (available from Dow Cornil1g Cor?oration) was charged at ~0 to 30~c in~o a s~-.es of bott~es con~i~ g ~
and dissulved in order to form thick syrups. To ~he resulting thick syrups were added various ratios of IOA/AA or IOA/~A/NVP monomers. In addiuon.
15 VAc/NVP capped macromonomer or uneapped copolymer stabilizer was added to the syrups. The syrups were then diluted to 40% solids with MEK
containing VAZO~ 64 initiator. The resulting solutions were purged with N2 for 2 ST inutes at the rate of 1 LPM and tumbied for 20-24 hours in a constant temperature bath at 65C. Specifics of these ~ormulations are presented in 20 Table I. Pereentage solids showed 9i-99% conversion.

-- C~nt~l Ex~mp~
The procedure of Examples 3-13 was followea except that st~bilizer was not included. Spe~ifics of the formula~ion are presented in 25 Table I. Percentage solids showed 97-99% conversion.

Control Exan~ple B
The procedure of Examples 3-13 was followed except that fluoroalkyl s~ioxa~e was not included. Specifics of the formulation are 30 presented in Table I. Percentage solids showed 97-99% collversion.

~.
wo 94/06878 ~ g~3 18- Pcr/U~93/08767 ~: :

, Table I

g VA~/NVP
SExam~leLS-2860 ~ cl AA ~P Stabilizer c~ MEK q VAZO-64 Control Ex. A12.0 25.2 2.8 ~ 61.0 0.24 ~ 3 12.0 25.2 2.g ~ 4.o2 61,0 0.~4 i 10 4 12.0 26.0 ~.0 ~~~ 4.o2 60.0 0.~4 12.~ 26.6 1.4 --- 4.0~ 65.0 0.24 ~ 6 6.0 21.6 0.961.44 3,o2 ~6.0 0.18 'I 7 6.0 22.1 0~501.44 3.o2 47,0 0.1~3 Jl ~ 6.0 21.6 1.~40.50 3.0Z ~6.0 O.la i 15 9 6.~ 21.1 1.4~1.44 3.o2 46.0 0.18 , 10 6.0 2~.6 1.440.96 3.o2 45.0 0.18 11 6.0 , 20.6 1.921.63 3.o2 45.0 0.1~
12 6.0 20~2 2.401.44 3.o2 4S.0 0.18 13 ~.0 21.6 1.4~O.g6 3.0~ ~5.0 20 Con~ol Ex. ~ 45.0 3.02.0 --- 70.0 0.24 ~ lUncapped V~/NVP ~o~olymer prepared according to Ex~mple !.
;`i 2Capp~d VAC/WVP macromonomer prepared accor~ing to Ex~mple 2.

.,~ . . ~ .
Control Example A yie}ded phase sep~ted material, and was thus rejected ~r further evaluation.
The purpose of Example 13 was to determine the e~fect o~
uncapped VAc/NVP stabilizer on polymeri~ation. A homo~eneous solution was obtained after the polymerization whether capped or u~cap~ed VAc/NVP
, stabilizer was used.
,,.,i Example 14 The procedure of Examples 3-13 was repeate~. The charges were as ~ollows: fluoroalkyl silicone LS-2860 (5.0 g), n-butyl acrylate ~18.0 g), acrylic a~. (1.2 g), N-vinyl pyrrolidone ~0.8 g), IEM-c~pped vinyl ace~e/N-vinyl pyrrolidone (2.5 g ~ 36.9% solids), Vazon' 64 (0.15 g), and methyl ethyl ke~one (37.5 g). Pereen~age solids showed 97-99% conversion.
. 4a WO 94/0687~ 2 1 ~ 2 8 9 9 PCI/US93/08767 ' ~
-19- ~ ' Example~
The procedure of Examples 3-13 was repeated. The charges were as follows: fluoroal}cyl silicone LS-2860 ~5.0 g), 2-ethylhexyl acrylate (18.0 g), acrylic acid (1.2 g), N-vinyl pyrrolidone ~0.8 g), IEM-capped VAc/NVP (2.5 g 36.9% solids~, Vazo~ 64 (0.15 g) and methyl ethyl ketone (37.5 g). Percentagé solids showed 97-99% conversion.
E~am~
The pr~cedur- of ~c~mples 3-13 was ~epeated. The cl~ges were as follows: fluoroalkyl silicone LS-2860 (5.0 g), ethyl ac~late (18.0 g), acrylic acid (1.2 g), N-vinyl pyrrolidone (0.8 g), IEM-capped VAc/NVP (2.5 g 36.~9'o solids),~Vazo~ ~ ~0.15 g), and methyl e~hyl ketone ~37.5 O).
Percentage solids show~ 97-9950 conversion.

~5 Exam~le 17 The procedure of Examples 3-13 was repeated. The charges were as follows: fluoro~kyl silicone l,S-2860 (5.0 g), isooctyl acrylate (18.0 g), acrylic acid (1.2 g), N-vinyl pyrrolidone (0.8 g), IEh/I-capped VAc/~ (2.5 g 36.9% solids), Va~ 64 (0.15 g) ard rnethyl ethyl ketone (37.5 g)~ Percentage solids showed 97-99æ conversion.

The approximatel~ 40% solids soiu~ions of Exarnples 3-12 and 14-17 we~e coated on corona-trea~ polyethylene terephthalate films after adding 0.3 weignt percent bisamide (N,N'-bis-1,2-propyleneterephthalamide) curing agent to each solution based upon the weight of the solution. The coated films were dried ard cured in an air-~orced oven at 65C for 15 to 2~ mir.utes and stored in a eonstant-temperature and eonstarlt-humidity room for 24 hours.
Results for adhesion to glass, aiuminum and fluorosilicone bacl~ing are snown in Tabl~ II. The data contained in Table II demonstrates that the adhesive of the invention exhibits good to excellent adhesion to glass. aluminum, and fluorosilicone backing rnaterial when compared to Control B (whieh does not contain a fluorosiloxane polymenc segment). Control Example B
(IOA/AA/~VP3 shows adhesion of 9.8 N/dm to fluorosiiicone backing matenaJ, compared to 44 Nidm for the adhesive of Example 17.

WO 9~/0687g f~ 1 4 ~ 8 9 9 Pcr/usg3/og767 Solvent-~si~nce Tç~ts The approximately 40% solids solutions of Examples 9, 10, 14, 15, 17, and Control Example B were coated onto corona-~reated polyethylene terephthalate filrn after adding 0.3 weight percent bisamide curing agent to each 5 solution, based upon the weight of the solution. One-half inch str~ps (1.27 cm) of the PET tapes coated with adhesiv~ were laminated to aluminum plates then aged at conseant temperature ard humidity as above. Adhesion to aluminum was deterrnined as above for half of the sarnples, and the other half were soak~d in various iluids, as nol~ in Tabie III for Ihr~ hours then tested for 10 peel adhesion. Comparative results ~eported in Table III show that the fluorosiloxane-containing adhesives of the present invention reta~n supenor adhesion to aluminum arter soaking in fluids as descri~ed. After soaking in JP^4 jet fuel (available from the Shell Oil Company) for 3 hours, Control Example B showed adhesion loss of more than 80%, while Example 17 showed 15 adhesion loss of only 3%. Tapes soaked in hydraulic fluid or engine oil did not leave any residue on removal from aluminum test panels while tapes soaked in JP-4 jet fuel or deicing fluid left only trace am~unts of residue on removal from the panels.
The deicing fluid used was 02143 TEXACO Aircraft I)e-Icing 20 Fluid WD-30, available from the TEXACO l~ubrican~s Company, Houston, Texas. WD-30 comprises 80 to 95 % 1 ,~-eth~edio} ~nd 4 to l l ~c deionized water. The hydraulic fluid used was 01537 Aircraft Hydraulic Oil 15, av~ilable from Texaco, Inc. The hydrauiic fluid compr~ses 65 to 80% petroleum oil, 20 to 35% methacrylate polymer, less than 1~ tnaryl ph¢sphate. and less than I ~0 25 ditertiarybutyl phenol. The engine oil used was Turbo Oil 2380, which is a synthedc aviation lub~icant, available from EXXON Company, U.S.A. The engine oil compnses L00% polyol esters and proprie~.arv additives. JP~ jet el re~ers ~o 2n ind~s~ry standard ~et fue! which is a~,aila~le co;n.~.ercially from a number of sollrces.

;l ~.

... .
~, ~14~y WO 94~06878 Pcr/us93/n~767 ~ _ Table II
Example Adhesion* ~o Adhesion* to Adhesion~ to Glass Aluminum Fluorosilieone !N/dm) ~N/dm) (N/dm) 3 8.8 61.4 21.6 4 ~5. 1 30.4 40.7 32.6 41.1 36.3 6 56.3 55.9 3~.3 7 36.5 dl . l 30.6 8 58. 1 53.0 36.7 9 55.9 52.4 32.3 56.8 5~.0 41.8 - 41.6 ---12 --- 16.7 ---14 59.4 55.2 5~.2 53.0 49.7 40.3 16 7.5 ~.$ 4.8 :
17 49.0 41.4 44.G
Control ~x. : 70.3 71.'~ 9.8 ~: B

:
', .

W094/~687~ 4~,~,g9 -22- P~/US93/0~7~7- ~

==1~ rr5 5 ~ , 1.
~ o c~ a~ ,, ~ .o54 ~ ~ l ll l lo I e !, ~
¦ r ~ r ¦ S 7 . 1~ ~ ~ B~ ~ 8 ~1 ~ ! ~ ~ ~ ~ ~1 I I I ~ j E
t~l I E~i , _ _ _ ,--~ I ~ '"

¦ 9~ 1 _ e ~ 0 ~ t;~ o~ ~ ~ ~ ~ Ir~ --~ ao ~: ~: ~, o r~ ~.~ u~ _ ___ ___ ___ .~
; .~ ,_ ~.
.'' ~ ~, ~ v~ r ~ ~ o ~
, t~ ~: ~ ~1 ~ ~J G t-- . _ j .
.~: ________ .~ . : .C~
C~ C~ tn' ~ ~ O O o o ~ , ~ ~ A
_*

Claims

What is claimed:

1. An adhesive composition comprising:
a dispersion comprising the polymerization product of a mixture comprising:
(a) about 5 to about 40 parts by weight of a fluoroalkyl siloxane of the formula (I) wherein;
R9 is independently selected from the group consisting of -CH2CH2Rf and -R7, Rf is a fluoroalkyl group independently selected from the group consisting of CmF2m-1 and C?F(2a+1)-qH?, m is an integer ranging from about 1 to about 20;
n is an integer ranging from about 1 to about 20;
q is an integer ranging from about 0 to about 2n;
x is an integer of about 11 or greater;
the fluoroalkylsiloxane comprises 10 or greater -CH2CH2Rf groups;
the fluoroalkylsiloxane comprises at least 1 R7 group;
wherein R1, R2, R3, R4, R5, R6, and R8 are each dependently selected from the group consisting of alkyl groups comprising about 1 to about 12 carbon atoms, aralkyl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, and hydrogen; and R7 is an organic group comprising at least two carbon atoms wherein at least 1 olefinic moiety is contained within R7;
wherein the ratio of R7 to -CH2CH2Rf is such that the mole percent of the olefinic moiety content contributed by R7 of the fluoroalkyl siloxane is between about 0.1 and about 4;
(b) about 60 to about 95 parts by weight of free radically polymerizable monomer, wherein the free-radically polymerizable monomer comprises:
(i) about 1 to about 20 percent by weight of free radically polymerizable polar monomer; and (ii) about 80 to about 99 percent by weight of free radically polymerizable non-polar monomer;
wherein the weight percentages of (i) and (ii) are based upon the total weight of (i) plus (ii); and wherein the total weight of (a) plus (b) equals 100 parts by weight total;
(c) about 0.1 to about 1 part by weight of a free radical initiator based upon 100 parts by wwight total of (a) plus (b);
(d) about 2 to about 10 parts by weight of a stabilizer based upon 100 parts by weight of total of (a) plus (b) wherein said stabilizer has a number average molecular weight ranging from about 8000 to about 25,000 and wherein said stabilizer is selected from group consisting of:
(i) a copolymer comprising (A) about 40 to about 60 parts by weight of monomer selected from the group consisting of vinyl esters of C1 to C8 monocarboxylic acids and C1 to C12 alkyl (meth)acryhtes, and (B) about 60 to about 40 parts by weight of monomer selected from the group consisting of N-vinylpyrrolidone, acrylamide, N,N-dimethylacrylamide, N-vinylcaprolactam, and mixtures thereof wherein said copolymer stabilizer comprises 100 parts by weight total of the monomers of (i)(A) plus (i)(B); and (C) about 0.5 to about 5 weight percent of a chain transfer agent based upon the weight of the monomers of (i)(A) plus (i)(B);
(ii) a macromonomer comprising the reaction product of the copolymer of (d)(i) wherein said chain transfer agent selected provides said copolymer with at least one functional group selected from the group consisting of -NH2, -COOH, -OH, and combinations thereof, with an encapping agent selected from the group consisting of isocyanatoethyl methacrylate, alpha, alpha-dimethyl-meta-isopropenyl benzylisocyanate, vinyl azlactone, para(chloromethyl) styrene, glycidyl methacrylate, and mixtures thereof, wherein at least about 95 % of the functional groups selected from the group consisting of -NH2, -COOH, -OH, and combinations thereof, of the copolymer are reacted with the endcapping agent; and (iii) mixtures thereof; and (e) about 30 to about 95 percent by weight of an organic solvent based upon the total weight of (a) plus (b) plus (c) plus (d) plus (e).

2. The adhesive composition of claim 1 wherein said nonpolar monomer is selected from the group consisting of monofunctional acrylate esters of primary alcohols, the molecules of which comprise from about 1 to about 14 carbon atoms, the monofunctional acrylate esters or secondary alcohols, the molecules of which comprise from about 1 to about 14 carbon atoms, and mixtures thereof.

3. The adhesive composition of claim 1 wherein said polar monomer is selected from the group consisting of acrylic acid, itaconic acid, hydroxy alkyl acrylates, cyanoalkyl acrylates, acrylamides, substituted acrylamides, N-vinyl pyrrolidone, acrylonitrile, and mixtures thereof.

4. The adhesive composition of claim 1 wherein said non-polar monomer is selected from the group consisting of isooctyl arvylate, isononyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, n-butyl acrylate, hexyl acrylate, and mixtures thereof.

5. The adhesive composition of claim 1 wherein said macromonomer is selected from the group consisting of vinyl acetate/N-vinyl pyroiidone copolymer end capped with isocyanatoethyl methacrylate, and vinyl acetate/N-vinyl pyrrolidone copolymer endcapped with alpha, alpha-dimethylisopropenyl benzylisocyanate, and mixtures thereof.

6. An adhesive comprising the cured adhesive composition of claim 1.

7. The composition of claim 1 which further comprises about 0.1 to about 0.5 percent by weight of a crosslinker based upon the weight of (a) plus (b) plus (c) plus (d), wherein said crosslinker is selected from the group consisting of multifunctional aziridine amides, soluble metal salts, metal complexes, silanes, triazines, aromatic ketone monomers, and mixtures thereof.

8. An adhesive comprising the cured adhesive composition of claim 7.

9. An adhesive comprising the polymerization product of:
(a) about 5 to about 40 parts by weight of a fluoroalkyl siloxane of the formula (I) wherein:
R9 is independently selected from the group consisting of -CH2CH2Rf and -R7, Rf is a fluoroalkyl group independently selected from the group consisting of CmF2m-1 and CaF(2a+1)-qHq, m is an integer ranging from about 1 to about 20;
n is an integer ranging from about 1 to about 20;
q is an integer ranging from about 0 to about 2n;
x is an integer of about 11 or greater;
the fluoroalkylsiloxane comprises 10 or greater -CH2CH2Rf groups;
the fluoroalkylsiloxane comprises at least 1 R7 group;
wherein R1, R2, R3, R4, R5, R6, and R8 are each dependently selected from the group consisting of alkyl groups comprising about 1 to about 12 carbon atoms, aralkyl, alkaryl, alkoxy, alkylamino, hydroxyl, fluoroalkyl, and hydrogen; and R7 is an organic group comprising at least two carbon atoms wherein at least 1 olefinic moiety is contained within R7;
wherein the ratio of R7 to -CH2CH2Rf is such that the mole percent of the olefinic moiety content contributed by R7 of the fluoroalkyl siloxane is between about 0.1 and about 4;
(b) about 60 to about 95 parts by weight of free radically polymerizable monomer, wherein the free-radically polymerizable monomer comprises:
(i) about 1 to about 20 percent by weight of free radically polymerizable polar monomer; and (ii) about 80 to about 99 percent by weight of free radically polymerizable non-polar monomer;
wherein the weight percentages of (i) and (ii) are based upon the total weight of (i) plus (ii); and wherein the total weight of (a) plus (b) equals 100 parts by weight total;
(c) about 0.1 to about 1 part by weight of a free radical initiator based upon 100 parts by wwight total of (a) plus (b);

(d) about 2 to about 10 parts by weight of a stabilizer based upon 100 parts by weight of total of (a) plus (b) wherein said stabilizer has a number average molecular weight ranging from about 8000 to about 25,000 and wherein said stabilizer is selected from group consisting of:
(i) a copolymer comprising (A) about 40 to about 60 parts by weight of monomer selected from the group consisting of vinyl esters of C1 to C8 monocarboxylic acids and C1 to C12 alkyl (meth)acryhtes, and (B) about 60 to about 40 parts by weight of monomer selected from the group consisting of N-vinylpyrrolidone, acrylamide, N,N-dimethylacrylamide, N-vinylcaprolactam, and mixtures thereof wherein said copolymer stabilizer comprises 100 parts by weight total of the monomers of (i)(A) plus (i)(B); and (C) about 0.5 to about 5 weight percent of a chain transfer agent based upon the weight of the monomers of (i)(A) plus (i)(B);
(ii) a macromonomer comprising the reaction product of the copolymer of (d)(i) wherein said chain transfer agent selected provides said copolymer with at least one functional group selected from the group consisting of -NH2, -COOH, -OH, and combinations thereof, with an encapping agent selected from the group consisting of isocyanatoethyl methacrylate, alpha, alpha-dimethyl-meta-isopropenyl benzylisocyanate, vinyl azlactone, para(chloromethyl) styrene, glycidyl methacrylate, and mixtures thereof, wherein at least about 95 % of the functional groups selected from the group consisting of -NH2, -COOH, -OH, and combinations thereof, of the copolymer are reacted with the endcapping agent; and (iii) mixtures thereof.

10. The adhesive of claim 9 which further comprises about 0.1 to about 0.5 percent by weight of a crosslinker based upon the weight of (a) plus (b) plus (c) plus (d), wherein said crosslinker is selected from the group consisting of multifunctional aziridine amides, soluble metal salts, metal complexes, silanes, triazines, aromatic ketone monomers, and mixtures thereof.