CA1328585C

CA1328585C - Polyester film primed with an amino functional silane, and film laminates thereof

Info

Publication number: CA1328585C
Application number: CA000601446A
Authority: CA
Inventors: Howard Wayne Swofford
Original assignee: Hoechst Celanese Corp
Current assignee: CNA Holdings LLC
Priority date: 1988-06-15
Filing date: 1989-06-02
Publication date: 1994-04-19
Anticipated expiration: 2011-04-19
Also published as: NO892475D0; JPH0625273B2; KR930010655B1; IE891916L; CN1038658A; MX169509B; US4898786A; DE68924100T2; KR910000872A; DE346768T1; NO892475L; AU605738B2; EP0346768A2; JPH0238432A; EP0346768B1; AU3593089A; DK290789A; ZA894480B; FI892945A; DE68924100D1

Abstract

ABSTRACT OF THE DISCLOSURE
Oriented polyester films primer coated with a hydrolyzed amino silane are disclosed. These silanes in the unhydrolyzed state have the formula:
XSi(R2)a(R3)b wherein X is a radical selected from the group consisting of H2NR1HNR1 - and H2NR1HNR1HNR1 -; the R1's are the same or different groups selected from the group consisting of C1 to C8 alkyl or phenyl; R2 is a hydrolyzeable group selected from the group consisting of C1 to C8 alkoxy, an acetoxy group or a halide; R3 is a nonreactive, nonhydrolyzeable group selected from the group consisting of C1 to C3 alkyl or phenyl; (a) is an integer ranging from 1 to 3; (b) is an integer ranging from 0 to 2, with the sum of (a) and (b) being 3.
The hydrolyzed aminosilane is applied to the film as an aqueous solution at any suitable stage during manufacture of the film, i.e., before or during the stretching operation, or it may also be applied to the finished film, The resultant primed polyester film is found to exhibit excellent adhesion to other polymeric materials and can be readily laminated to other polymeric films. Adhesive qualities are maintained even at subfreezing temperatures.

Description

1328S8~ 71033-66 POLYESTER FILM PRIMED WITH AN
AMINOFUNCTIONAL SILANE, AND
FILM ~A~INATES THEREOF
The present inventlon relates to orlented polyester fllm coated on one or both sldes wlth a prlmer coatlng composltlon comprlslng a hydrolyzed aminofunctlonal sllane whlch renders the fllm more receptlve to lamlnatlon wlth other polymerlc fllm materlals such as polyvlnylbutyral, polyoleflns and other polymers.
~ACKGROUND OF THE INVENTION
The present appllcatlon ls related to appllcants copendlng Canadlan Patent appllcatlons Serlal No. 583,769, flled November 27, 1988, and appllcatlon Serlal Number 588,2~4, flled January 16, 1989 (DF 1213).
Orlented polyester fllm partlcularly blaxlally orlented fllm composed of polyethylene terphthalate (PET), has been widely used as a packaglng materlal or as a base for ~`! mlcrofllm reprographlc fllms, prooflng fllms and the llke. It has good optlcal clarlty and toughne~s whlch renders lt extremely sultable for such appllcatlons.
- Polyester fllms have recently found expanded appllcatlons as transparent and translucent layers applled to ; solld substrates and partlcularly to transparent substrates.
Thus, such fllms may be applled to wlndows and vlewlng or llghtlng medla to control the transparency thereof. Another more recent appllcatlon for polyester fllm lnvolves lts use as `, an antllaceratlve layer in the constructlon of automotlve ~ glazlng products such as wlndshlelds, rear wlndows, sun roof -; panels and the llke, and ln archltectural safety glass. One of the slmpler automotlve glazlng products may comprlse a flexlble lnterlayer of polyvlnylbutyral sandwlched between glass on one slde and a hlgh modulus fllm, for example polyester fllm, on the opposlte slde.

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1328~85 Polyvlnybutyral layers are used ln sandwich automotive glass constructlon to prevent breaklng of the glass ln the case of lmpact (so called safety glass), whereas the role of the polyester fllm posltloned on the interlor glass surfaces ls to prevent skln lacerations caused by hard impact of the head or body with automotive glass causing the glass to shatter, as a consequence of an automobile accldent.
Constructlons of thls type and technlques for applylng the polyester film to automotive glass surfaces are disclosed ln Canadian copendlng appllcation Serial Number 588,294, filed January 16, 1989 ~DF 1213).
The above referenced copending appllcation teaches the use of a layer of plasticized polyvlnylbutyral (PVB) as an adheslve layer to facllltate adheslon of the polyester fllm to the glass. Whlle PVB adheres very well to glass, the adheslon between lt and polyester ,~ ~

1328~8~

film is not as great, particularly at sub~reezing temperatures Corona di~chargQ treatment and~ flame trea~ment have been used to g~ve adhesion between PVB
sheet and polyester ~ilm a~ di~closed in US Patent No 3,900,673 Coatings o~ gelatin and PvDC and acrylic latex coatings have also gi~en adhesion between polyester fil~ and PVB However, none of these methods of imparting adhesion give adhesion at the 6ub~reezing temperatures to which windows in automobiles and buildings are commonly sub~ected It is believed that any ~mprovement o~ the adhesion of the polyester film to the PVB improv~s th- ~unotion of the polyester ~ilm as an antilacerativ- shield Numerous primer coatings arc known in the prior art for the application to the ~urfac- of polyester film to improve the adhesion or the rilm to various materials Examples of such coating~ include compositions based on vinylidene chloride polymor~ ~US Patent 2,698,240), thermosetting acrylic or methacrylic polymers (US
Patent 3,819,773) and lik- materials Certain water dispersible copolyester- have also been disclo~ed as adhesives for laminating sh-et~ Or polyester film to one another or to she~t- Or nylon rilm, as taught in US r Patents 3,563,942 and 3,779,993 Solvent based polyurethane adhesives have al-o been used to promote adhesion, but with attendant problems o~ solvent emis~ions and sa~ety ~he use o~ silane coupling agent~ to improve the bonding properties Or polyethyl-ne sheet~ and polyester sheets is known For exampl-, polyester sheets and polyethylene sheets primed with either vinyl trimethoxy ¦
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I' 1328~85 silane or chloropropyltrimethoxy silane have been successfully laminated us1ng a hot melt adhesive such ` as an ethyleneJvinylacetate terpolymer or an elastomeric polyester as d~sclosed by E Plueddemann, "Bonding Through Coupling Agents", Plenum Press, New YorX, 1985 In addition, the USQ of N-2-aminoethyl -3-aminopropyltrimethoxy ~ilans (sold under the trademark Z-6020 by Dow Chemical) as a primer coating to enhance the adhesion of an ionomer resin ~salt of a copolymer of ethylene and ~ethacrylic acid) to glass and to polycarbonate sheot~ i- disclosed in US Patent 4,663,228 Related ~ilane~ such as N-3-aminopropyltrialkoxy ~ilane~ are Xnown to enhance the adhesion between polyurethane films and glass substrates, as disclosed in published European~Patent Application 171,917 None of these prior art diwlosure~, however, addresses the problem of the maintenanc- of good adhe~ion between polyester Silm and polyvinylbutyral or other polymer films at ~ub~reezing temp~ratur-s where many primer materials fail Accordingly, it is an ob~-ct oS this invention to provide an oriented, ~elf upporting ~ilm material having enhanc-d adhe~ion when laminated with other polym-r films , , . , - A further ob~oct i~ to provid- a primer coating for , 30 polyester film which enhanc-s adhesion between ! polyester and polyvinylbutyral ~ilm~ and impartsresi~tance to delamination oven at ~ubfreezing l, temperature~ l ,1 .

1328~8~ 1 , SUMMARY ~F THE SNVE~TION

l These and other ob~ects o~ th~ invention may now be 1 achieved by the proYision o~ an oriented polyester film which has ~een primer-coat-d with a hydrolyzed aminofunctional ~ilane The aminofunctional silanes userul as a primer layer for the purposes of this invention are diamino or triamino silanes responding in their unhydrolyzed state to the general formula XSi(R2)~tR )b lS wherein X i~ a rad~cal selected from the group consisting of H2NRlHNRl - and H2NRlHNRlHNRl -; the Rl's are the same or different groups selected from the group consisting or cl to C8 alkyl or phenyl; R2 is a hydrolyzeable group selected ~rom the group consisting of Cl to C8 alkoxy, an acetoxy group or a halide; R3 is a nonreactive, nonhydrolyzeabl- group selected from the group consisting o~ Cl to C3 alkyl or phenyl; (a) is an intogor ranging from 1 to 3S ~b) i8 an integer ranging from 0 to 2, with the ~um Or ~a) ~nd ~b) belng 3 Examples Or u$table ~ilanes include N-t2-aminoethyl)-3-aminopropylmethyl-dimethoxysilane, N-~2-aminoethyl-3-aminopropyl) trimethoxysilane, N-2-am$noethyl-3-aminopropyltri~ ~2-ethylhexoxy) silano, 6-~aminohexylaminopropyl) trimethoxysilane, ~am$noethylaminomethyl) ph-n-thyltrimethoxysilane and N-2-aminoethyl-2-aminoethyl-3-am$nopropyltrimethoxysil-ane 1~2%~3 The more pre~erred nilane~7 ~or the purpo~es of this invention are dia~ino prim~ry Amines having the following formula H2NR NHR ~ ~ b wherein the Rl's are the ~ame or different alkyl radicals having from 1 to 3 carbon 2toms, R2 is a Cl to C3 alkoxy group, ta) is7 3 and (b) is 0 ~he most preferred are silanos O~ the above formula wherein Rl and ~2 are Cl to C3 alkyl radlcals, R3 is a Cl to C3 alkoxy group, ~a) is 3 and tb) is 0 The most preferred ~ilane i~ N-2~aminoethyl-3-aminopropyl) trimethoxy ~ilane having thQ formula ..
H2N(CR2)2NH~CH2)3sitocH3)3 The hydrolyzed aminosilan- i- applied to the film as an agueous ~olution at any uitable stage during manu~acture of the film, i - , before or during the ~tretch$ng op-r~tion, or it may al~o be applied to the ; fini~hed ~ilm, ~he rQsultant pr~med polye~tor ~ilm is found to xhibit xc~ nt ~dh-~ion to other polymeric materials and can be roadily laminat-d to other polymeric ~ilms. Adhesiv- qualitie- are ~aintained evon a,t ub~r-ezing t~mp-r~tur -;' ' .

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1328~8~

; DETAILE~ DESÇRIP~ION OF ~HE INv~NTION

The primer formulation of this invention is prepared by mixing the a~inosilane with water ~t a level within the range of about 0 2 to ~bout 6~ by weight Optionally, a weak acid ~uch a~ acetic acid may be added to facilitate hydrolysi~ At least one of the hydrolyzeable groups of the silane i~ hydrolyzed into a silanol group ~SiOH) It i5 believed that the hydrolysis product of the a~inosilane has a partially hydrolyzed, cyclized structure, with the amino group probably forming ionic bonds to the silcon portion o~
the molecule Thu~, the term hydrolyzed as used herein also may refer to such partially hydrolyzed structures ; Althouqh the preferred xempli~ied film wh$ch may be primer coated in accordanco with the present invention is polyester Silm, the invention i8 egually applicable to other high modulus films including polyamide film i 20 and polycarbonate film The base ~ilm used normally has a higher modulu~ or tiffnes~ than the polymer or sheet to be laminated to it, and a higher melting or softening point The proferr-d oriented polye~ter ~ilm base for the purpo-e- of thi~ inv-ntlon i- made from polyethylene tereph~halate, although th- invention is equally applicable to film ba~ed on a cry~tallizablo polyester resulting from the polycond-nsation Or a glycol such as ethyl-ne glycol or butan- diol ~nd mixtures thereof with terephthalic acid or mixtures o~ terephthalic acid and other dicarboxylic acid~ ~uch as isophthalic acid, diphenic acid and sobacic acid, or their polyester f 1328~85 ~

forminq eguivalent~, which polyesters are made by methods well known in the ~rt The fil~ may be produced by technique~ al~o ~-11 known in the art using well known apparatus For example, the polyester i8 melted and extruded as an amorphous sheet onto a polishea revolving casting drum to form a cast ~heet o~ the polymer Thereafter, the film is axially stretched in one direction, either in the direction of extrusion (longitudinal), or perpendicular to the direction of extrusion (transverse) in th- ca~e of nonoaxially oriented film, and in two directions in th- ca~e of biaxially oriented film, that i~, the fil~ i~ stretched in both the longitudinal and tran~ver-e directions The first stretching, to impart ~trength and toughness to the film, can range from about 3 0 to about 5 0 times The hydrolyzed aminos$1an- primer coating of this invention in the form of an agueous solution may be appll-d in-line at one o~ thre- ~tageQ during the film manufacture; the pr--draw ~t~ge ~t the point between the casting of the amorphou- ~heet and the first str~tch ~uch as di~closed, ~or xamplo, in British Patent No 1,411,564, the int-r-draw stage subseguent to the uniaxial drawing but prior to biaxial drawing such ~8 disclo~ed, ~or -xample, in the U S Patent No 4,21~,03S; or th~ po~t dr~w tag- ~ubsequent to biaxial stretching, but prlor to winding the film Normally, the heat applied to the flln during th- stretching or final condltioning stages i- ~u~ricient to evaporate off the water and other volatiles and dry the primer coating, although a~ ~eparate drying ~tep would ~e !

132~85 reguired if the coating were applied subsequent to such heatin~ steps ~he coating ~ay al80 be appl$ed off-line to fini~hed film ~uch a~ by fir~t subjecting the film surface to a corona dl~charge treatment prior to the coating operation ThQ film surface is then dried to remove the water In one preferred embodiment, the primer coating is applied after the film i8 uniaxially stretched, that is, after the film ~5 ~tr-tched in one direction, but before the ~ilm i8 ~tretched in the orthogonal direction In anoth-r pr~f-rred embodiment, the polyester film i8 first atretched in the longitudinal direction prior to coating In this preferred embodiment, after longitudinal stretching, the film is coated by any of the well known techniques employed in the art For exampl-, coating may be effected by roller coating, ~pray coating, slot coating or immer~ion coating In a prof-rred embodiment, the polyester film is coat-d by mean~ of a gravure cylinder Al~o, tho uniaxially drawn film is preferably subjected to a corona aischarge by a corona discharge apparatu~ prior to coating a- ~ known in the art The discharge treatment docr-ases the hydrophobic character of th- polyestor f~ urfac~, which permits the water based coating to more asily w-t tho ~urfaco and thus improve tho adho~ion of th- coating to th- surface ~he hydrolyzed amino ilan- of th- pr-sent invention is applied to the base film a- an aqueous ~olution at a concentratlon o~ from about 0 2 to about 6% by weight of the hydrolyzod amino~ilan~ A weak acid such as ac-tic, phosphoric or th- llk- 1- th-n added at a l-vel ~ .
.
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lo 13285~5 of from about 0.1 to about 0.5% by we~ght to facilitate hydrolysis. The preferred 1~VQ1 of addition of the acid is about 0.2% by weight. Th~ preferred concentration of the hydroIyzed aminosilane is within the range of about 0.5 to about 2.5% by weight. The preferred concentration is 6uch to yield a final dry primer coating weight of ~roa about 0.10 X lo 6 to about 20 X 10 6 lbs. per sguare foot of film.
Preferably the range i5 from about 0.20 X 10 6 to about l.S X 10 6 lbs. per sguaro foot, with about 0.80 X 10 6 lbs. per square foot being the target weight for coatings applied in-line. Wh-re the coating is applied off-lin~ to flnished film, the target dry coating weight is about 10 X 10 6 lbg~ per square foot.
The coating of this invention may be applied to one or both sides of the fllm, or it may be applied to one ; side and a different coating such as a thermosetting acrylic or methacrylic polymer applied to the opposite side, auch as taught in U.S. Patent Number 4,214,035.
The coating may also in 80me case~ be applied over a difrerent primer coating to which it w~ll adhere and which is already present on the surfacQ of the film, such as a thermosetting acrylic coating as described in U.S. Patent 3,819,773.

An especially signiticant application in the glass field is the utilization of polyQster film coated on one side with the primer coating of thi~ invention and on the opposite side with an abrasion resistant coating such as a radiation curable hydrolyzed vinyl-~unctional silane composition also containing a multifunctional cros~linking agent and an optional photcinitiator, such ll 71033-66 as dlsclosed ln Canadlan appllcatlon Serlal Number 583,769, flled November 22, 1988. Such materlals have shown to lrnprove the abraslon reslstance of the surfaces of a varlety of plastlc fllms, lncludlng polyester fllm maklng the fllms more useful ln appllcatlons where the surface ls llkely to be sub~ected to abraslon. Examples, of sultable vlnyl-functlonal sllanes dlsclosed ln the referenced appllcatlon lnclude vlnyl alkoxy sllanes such as vlnyltrlethoxysllane, vlnyltrlmethoxysllane and vlnyltrls (2-methoxyethoxy) sllane. Preferred crossllnkers are multl functlonal acrylate or methacrylate monomers such as ethoxylated trimethylpropane trlacrylate.
Other sultable abraslon reslstant coatlngs may also be used such as are dlsclosed for example ln US Patents 4,177,315, 4,239,798, 4,310,600 and 4,348,462.
The coatlng composltlon may also contaln other lngredlents 80 long as such lngredlents do not detract from the adheslon promotlng actlon of the hydrolyzed amlnosllane. Such would lnclude mlnor amounts of colloldal slllca, dyes, pH
regulatlng agents, wettlng agents and the llke. The prlmer 20 coatlng ls present on the fllm surface as a contlnuous coatlng, whlch term 1~ also lntended to lnclude cases where the prlmer may form a plurallty of lslands or segregated reglons of coatlng.
Scrap fllm made durlng productlon that 18 coated wlth the prlmer coatlngs of the lnventlon can be ground and f:

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mixed with fresb polye~ter, re-melted and re-extruded to produce orient-d film Such film produced containing ignificant quantltle~ Or primed scrap reclaim, exhibits very little degradation of physical properties due to the presence of the coating impurity and color generation i~ al80 low Thus, the primed film of thi~ $nvention of~er~ commercial advantage to the film manufacturer over many other primed films, such as films pri~ed with vinylidene chloride containing polymers as disclosed in U S Patent Numbers 2,627,088 and 2,698,240 , which tend to degrade and discolor when reclaimed a~ ~et ~orth above .. ..
j As indicated above, the primer coated ~ilm of this invention ~orms xcellent adhesive bonds with other plastic films to which it i8 laminated Examples of such ~ilms include polyvinylbutyral, polycarbonate, polyurethane polyole~ins ~uch as polyethylene or polypropylene, polystyrenQ and similar films Laminates may be madQ by forming a sandwich of the films and heating the ~tructur- to a temperature below the melting point of tho polyoster film but above the meltlng point o$ th- oth-r ~$1m, pre~erably while simultaneously applying ~od-rate pressure to the sandwich structures Pr-rerred heating temperatures generally range from about 12SC to 225C The other plastic $ilms used to form th~ laminates may themselves be primer coated lf de-ir-d An especially ~igni~icant application in the glas~
~ield i~ the utilization o~ poly-ster ~ilm coated on one ~ide with the prim-r coating o~ this invention The primed side o~ the polye-t-r film i~ laminated to a ~' .
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132858~

sheet of polyvinylbutyral that i8 also laminated to a ~heet of glass. For this application the preferred aminosilane i8 N-2-(a~inoethyl)-3-aminopropyl trimethoxysilane (AE- APTMS). Polyester film primed with AE-APTMS has high adhe~ion to polyvinylbutyral at ~ormal temperatur-s and al~o ha~ good adhesion to polyvinylbutyral at ~ubSreezlng temperatures where adhesion fails with other pri~ers and treatments.

The polyester ~ilm of this invention can be sandwiched between two layer~ of PVB and two layers of glass with at least one sidQ of the Silm primed with aminosilane and the other side either being primed with aminosilane ! or having a metal or metal oxide coating for solar control and IR reflection. In another configuration the polyester film is laminated to the interior or inboard sur~ace o~ the gla~s as an anti-lacerative layer with a layer oS PVB between the ~ilm and the gla~s; the slde oS the ril~ primed with aminosilane is laminated to the glas~ and th- other side of the film i5 protected by an abrasion re-istant coating.

The thickness of polyest-r ~ilm suitable ~or use in this invention may generally range Srom about 0.25 to about 10 mil~ or mor-. In multilayer automotive w~ndshield application~ the pr-Serred thickness` is on the o,rdor oS 3 to 4 mil~.

The following axample- ar illustrative oS the inv~ntion.

14 1328~8~ 1 ~~
N-2-(aminoethyl)-3-aminopropyltr~ethoxysilane (AE-APT~S) was dispero-d in ordinary tap water to form a concentration of 1 0~ by weight AE-APTMS Acetic acid wa~ then added at a conc-ntration of 0 2% by weight to facilitate hydrolyoio Polyethylene terephthalate polymer was melted and extruded through a lot die onto a casting drum maintained at a temperatur- of about 20C The melt froze to form a caot ~he-t The cast oheet was longltudinally stretched at a draw ratio of approximately 3 5 to 1 while mainta~ned at a temperature of about 80C Tho longitudinally drawn film was corona treated by a corona dischar~e apparatus and thereafter coated by r-veroe gravure with the ~; solution o~ hydrolyzed amino oilane prepared above The corona treated, longitudinally drawn, coated film was dri-d at a temperature o~ about 100C Thereafter, the film wao stretched in th- transverse direction at a drnw ratio of 3 9 to 1 to produce a biaxially drawn film The biaxially drawn fil~ wa~ then heat oet at a maximum temperature of 230C The dry weight of the coating was about 0 50 X 10 6 lb- per square foot of film The thickne~s of th- ba-- ~ilm wao about 3 mil~
i Primer coated films were prepared exactly as set forth in Example 1 abo~e except that the concentration of !

1328~85 AE-APTMS in the coating ~olution was 1 5~ by weight in Exampl~ 2 2 0% by w-ight in Example 3 and 2 5% by weight in Example 4 S ~;~L~ t In order to perforo comparatl~ tests solutions of N-3-aminopropyltrimsthoxy ilan- ~APTMS) having the formula H2N(CH2)3Si~OCH3)3 were prepared by the same method as in Example 1 Primer coated films were prepared exactly as set forth in Example 1 ~he concentration of APTMS in th- coating solution was 1 0%
by weight in Example S l S% by weight in Example 6 2 0% by weight in Exampl- 7 and 2 5% by weight in Example 8 ~.

Primer coated ~ilms wer~ prepared by the same method as set ~orth in Exampl- 1 Por Example 9 the primer coating was an acrylic latex applied from an aqueous dispersion at a concentration o~ 4~ by weight tThe acrylic coating i8 a copolymeric latex as described in US Patent No 4,S71,363 ) For Example 10, the primer coatlng wa~ an aqueou- disp-rsion o~ a water di~p-r~ible copolye~ter appll-d at a conc~ntration of 4~ by weight t~he wator di~persible copolyester coating i8 describ-d in US Pat-nt No 4,493 872 ) Adhe~ion of ach o~ th- ~ilm- pr-pared above to polyvlnylbutyral wa~ evaluat-d by laminating the film to a polyvinylbutyral ~heet and then testing the peel str-ngth of A 1 lnch wld~ trlp by dolng A ~ 0 peel 16 1328~8~

test in an ~nstron te~ter A 6 X 8 inch sheet of the coated film was laminated to ~Saflex TG" (sold by Monsanto Che~ical Company), a PVB sheet used in I automotive safety glas~, ~nd to gla88 by placing the side coated with a~inosilane in contact with the PVB
and placing the PVB in contact with the qlass A one inch wide ~trip of plain PET ~ilm (0 5 mil thick) was placed between the coat-d ~11~ and the PVB in order to provide a nonadhered leader ~or doinq the peel test A
sheet of "Xapton" (a Dupont trademar~) was placed on top of the polye~ter to -rve a~ a release liner and another piece of glas~ was placed on top of the Xapton This construction wa~ ~andwich-d between two pieces of cardboard, which serve3 to di-tribute pressure evenly, and the assembly was placed ln a hydraulic press that had been preheated to 150C The platens of the press were closed suf~iciently for contact to be made top and bottom between the platens and the cardboard and the construction wa- allowed to pr h-at for five minutes Pre~sur- wa~ then incr-a--d to 1150 p~i, and maintained for 30 minut-~ With th- pre~ur- maintained at 150, p5i tho platen~ wor- cool-d to room t-mperature with circulating water Once the plat-ns had cooled to room temperature tho laminat- wa- r-~oved One inch wide strip~ were cut in the PET ~il~ u~ing a scalpel To te~t tho peol ~trength, the laminated sample, PET/PVB/glass, wa~ plac-d ln an ln~tron te~ter with the gla~/PVB clamped in th- lower ~aw- of the In~tron and the nonadhered leader hanging ~r-e and pointing down toward the ~aw~ A length o~ t610 nScotchn tape ~a 3M
trademark) was doubled over and attached to the nonadh-r-d l-ad-r Th- l-ngth of Scotch tap- was th-n 17 1 3 2 8 ~ 8 ~ i clamped in the upper ~ws o~ the Instron ~he angle between the leader ~nd PVB/gla~ was 180 The peel ~; was done at a rate of 1 inch/min for a length of one inch ~hQ poak ~orc- n--d-d to peel the PET fro~ the PVB was read from thQ strip chart Three la~inated samples were ~adQ ~or ach xample For each 6 X 8 la~inated sample ~hrQe pull~ were done at room temperature (23C) and thre- pull~ were done at -10C
Results are shown in Tabl- 1 :C~

180 ~eel S
F~lm ~ _~

ple 1 15.1~ 8.1 E~ple 2 12.8 11.8 l~plo 3 8.7 ~10.8 E~pl~ 4 16.6 10.0 ple 5 8.3 0.0 EK~plo 6 5.3 0.0 E~pl~ 7 7.5 0.0 EX~pl~ 8 10.0 0.0 25EK~-~plo 9 3.8 0.0 ~pl~ 10 o,o o,o ~ PV~ delaminat-d ~rom tho glas~

As can be s~en ~rom th~ Tabl~ samples primed using the AE-APTMS amino ilano o~ this invention exhibit a marked improvem-nt in peel re~ist~nce in both the roo~ temperature t-~t and al~o when tested after ; , -1328~

conditioning at -10C for 2~ hours when compared with sample~ primed with a ~tandard water dispersible copolyester or nn acrylic lat~x. Film samples primed with APIMS ~how d adh-~ion nt room tQmperature, but essentially no adhe-ion art-r th- 24 hour cond~t~oning at -10C.

N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was coated o~r-lin~ (meaning on a coating line separate from the film production line) onto finished, crystallized, biaxially ori-nted PET film and nip laminated to PVB. The coating wa~ 1.5% Z-6020 (sold by Dow Corning) with 0.2% acetic acid added to promote hydrolysis. The film, running at 100 fpm, was corona treated and then coated using reverse gravure. The coating weight was 14xlO 6 lb-./ft.2. The coated film was then nip laminated to 30 mil sheet of polyv~nylbutyral using a nip roll at 220F and 400 lb./linear inch pre~-ure. Th- PET/PVE3 laminate was laminated to gla~ and tested a~ de~cribed for Examples 1-10. At 23C the pe-l adhe-ion was 12.5 lbs.in. At 16F the peel adhes~on wa- 1.4 lbs./in.

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A polyester fil~ coated on on- ide with AE-APTMS for adhesion to polyvinylbutyral ~ay be coated on the opposite side with a ~uitable anti-abrasion coating as follows:
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lg 132858~

48 0 grams o~ vinyltr~methoxy~ilane are added dropwise ! at room temperature to 72 gram~ of Nalco 1034A, a commercially availabl~ acidic colloidal silica, with gentle ~tirring u-ing a magnotic stirrer The mixture was stirred ~or ~ hours at roo~ temperature in a closed conta~ner and was then heated to 60C in a water bath for 30 minutes while till being tirred 4 8 grams of SARTOMER C-9035, a water-soluble, highly ethoxylated trimethylolpropano triacrylate commercially available from M C0 Specialty Chemicals, was mixed with 4 0 grams of isppropanol~ 0 9 gra~s of IRGACURE 500, a photoinitiator comm~rcially available from Ciba-Geigy, and 0 2 grams of a fluorinat-d urfactant commercially available from 3M under th- trademark Fluoral The resulting mixture was added to 12 grams of the silica/vinyltrimQthoxysilanQ condensate to form the radiatlon curabl- coatlng compo-ition The coating composition i- appli-d, using a ~18 Meyer rod, to a 4 mil thick, acrylic-primed ~ide of polyester film, which wa- primed on th- oth-r side with AE-APTMS
aminosilanQ in accordanco with Example 1 of this invention The coatinq ls ~irst dried in an oven maintain-d at 7SC for on- ~inut- and then crosslinked by W lrradiation by pa--ing the coated polyester ~ilm four tlmos through a RPC Eguipm-nt Co Modol QC 1202 proces-or at 2S fe-t/~inut- u-ing two 200 watt/inch lamps The abovo coating ua- ~ound to signific~ntly improvo th~ abrasion resi-tanc- o~ the coated side of the film ~urfac- rendering th~ ~ilm more useful in automotive vlnd-hl-ld;ppll~tlon-.

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Claims

1. An oriented self-supporting high modulus film having a continuous primer coating composition on one or both sides thereof, said coating composition comprising the dried residue of a hydrolyzed aminosilane compound having the formula in the unhydrolyzed state:
XSi(R2)a(R3)b wherein X is a radical selected from the group consisting of H2NR1HNR1 - and H2NR1HNR1HNR1 -; the R1's are the same of different groups selected from the group consisting of C1 to C8 alkyl or phenyl; R2 is a hydrolyzeable group selected from the group consisting of C1 to C8 alkoxy, an acetoxy group or a halide; R3 is a nonreactive, nonhydrolyzeable group selected from the group consisting of C1 to C3 alkyl or phenyl; (a) is an integer ranging from 1 to 3; (b) is an integer ranging from 0 to 2, with the sum of (a) and (b) being 3, said primer coating composition being present at a weight effective to improve the adhesion of other polymers to said film.

2. The film of claim 1 wherein said aminosilane compound is selected from the group consisting of:
N-(2-aminoethyl)-3-aminopropylmethyl dimethoxysilane, N-(2-aminoethyl-3-aminopropyl) trimethoxysilane, N-2-aminoethyl-3-aminopropyltris (2-ethylhexoxy) silane, 6-(aminohexylaminopropyl) trimethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane and N-2-aminoethyl-2-aminoethyl-3-aminopropyltrimethoxysil-ane.

3. The film of claim 1 wherein said film is polyester.

4. The film of Claim 3 wherein said film is biaxially oriented polyethylene terephthalate film.

5. The film of Claim 4 wherein said amino silane compound has the following formula in the unhydrolyzed state:
H2NR1NHR1Si(R2)a(R3)b wherein the R1's are the same or different alkyl radicals having from 1 to 3 carbon atoms, R2 is a C1 to C3 alkoxy group, (a) is 3 and (b) is 0.

6. The film of Claim 5 wherein said amino silane compound is N-2-(aminoethyl)-3-amino propyltrimethoxysilane.

7. The film of Claim 4 wherein said film is prepared by melt extruding a substantially amorphous polyester film and thereafter orienting the film by stretching it sequentially in two direction and heat setting the film, said primer coating composition being applied to said film as an aqueous solution prior to stretching the film in one direction, or subsequent to stretching in one direction but prior to stretching in a mutually perpendicular direction, or subsequent to stretching in two directions.

8. The film of Claim 7 wherein said film is subjected to a corona discharge treatment prior to the application of said primer coating composition.

9. The film of Claim 7 wherein said primer coating composition is applied subsequent to stretching in one direction but prior to stretching in a mutually perpendicular direction.

10. The film of Claim 7 wherein said amino silane compound is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

11. The film of Claim 7 wherein said primer coating composition is present at a weight within the range of about 0.10 X 10-6 to about 20 X 10-6 lbs. per square foot of film surface on a dry weight basis.

12. The polyester film of Claim 5 having a film of a different polymer adhered to the primer coated surface of said polyester film.

13. The film of Claim 12 wherein said aminosilane compound is N-2-(aminoethyl)-3-aminopropyltrimethoxy silane.

14. The film of Claim 13 wherein said polymer is polyvinylbutyral.

15. The film of Claim 13 wherein said polymer is polyethylene.

16. The film of Claim 13 wherein said polymer is polyurethane.

17. The film of Claim 13 wherein said primer coating composition is present at a weight within the range of about 0.10 X 10-6 to about 20 X 10-6 lbs. per square foot of film surface on a dry weight basis.

18. A laminate structure comprising a glass sheet, a polyvinyl butyral sheet adhering to the glass sheet, and the primer coated surface of the polyester film of Claim 4 adhering to the polyvinylbutyral sheet.

19. The structure of Claim 18 wherein the film is primed with N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

20. The structure of Claim 18 wherein the primer coating is present at a weight within the range of about 0.10 X 10-6 to about 20 X 10-6 lbs. per square foot of film surface on a dry weight basis.

21. A laminated structure comprising a glass sheet, a polyvinylbutyral sheet adhering to the glass sheet, the primed film of Claim 4, a second sheet of polyvinylbutyral adhering to the primed film, and a second sheet of glass adhering to the polyvinylbutyral.

22. The laminated structure of Claim 21 wherein the primed film has a thin metal or metal oxide coating on one side.

23. The structure of Claim 18 wherein the surface opposite the primer coated surface of said polyester film is coated with an abrasion resistant coating.