CA1336626C - Melt adhesive compositions - Google Patents

Abstract

A melt adhesive composition containing an amorphous polypropylene, a selectively hydrogenated monoalkenyl arene/conjugated diene block copolymer and a tackifier.

Description

MELT ADHESIVE COMPOSITIONS
BAc~GRouNn OF TH~ INY~NTION
1. Flel~ of the Inventlon Thls lnventlon relates to melt adheslve composltlons especlally useful ln adherlng polyolefln bodieY to themselves, to other polyolefln bodles and to other non-polyoleflnlc bodleY comprlslng a blend of ~1) an amorphou~ polypropylene (amorphou~ polyalphaolefln~), (2) a selectlvely hydrogenated monoalkenyl arene/conJugated dlene block copolymer of linear or radlal conflguration and (3) a tacklfler.

2. Descrl~tlon of the Prlor Art The preparatlon of adheslves contalnlng amorphous polypropylene and block copolymers contalnlng unYaturated mld block copolymer~, for example, polystyrene-polybutadlene-poly~tyrene (S-B-S) or polystyrene-polylsoprene-polystyrene (S-I-S), tacklfier and a rubber-extendlng oll 19 known, as evldenced, for example, ln U.S. Patent No. 3,862,068 to Russell. Such adhesives have llmlted elevated temperature melt stablllty, llmited reslstance to 2 and UV, but, most important, exhibit llmited performance characterlstlcs on untreated polyolefin surface~ whereln hlgh bond lntegrlty and durablllty are also requlred. U.S. Patent No. 3,686,107 to Rus~ell also dlscl 09e9 ~lmllar compo~ltlon~ havlng slmllarly undeslred characterlstlc~ noted above. St. Clalr et al ln U.S. Patent No. 4,~96,008 prepare~ a ~ealant compo~ltlon contalnlng a ~ 336 62b selectlvely hydrogenated S-B-S and S-I-S b10ck copolymer ln comblnatlon wlth tacklfylng reslns, plastlclzer~ and solvent~. U.S. Patent No. 4,138,378 to Dos~ also dlscloses a sealant formulatlon contalnlng selectlvely hydrogenated block copolymers, a polyalkene plastlclzer, a tacklfylng resln and a flller. St. Clalr et al In U.S. Patent No.
4,286,077 dlsclose the uYe of selectlvely hydrogenated block copolymers In comblnatlon wlth a tacklfler and a plastlclzer to obtaln a pressure sensltlve adheslve. Addltlonal varlants In adheslve preparatlons Involvlng the u~e of hydrogenated block copolymers are descrlbed ln U.S. Patent No. 4,151,057 to St. Clalr et al.
The patents dlscussed above are exemplary of the prior art lnvolvlng the utlllzatlon of varlous types of block copolymers ln the preparatlon of adheslves and sealants.
Obvlously, none of these references dlscloses the u~e of an amorphous polypropylene In comblnatlon wlth selectlvely hydrogenated monoalkenyl arene/conJugated dlene block copolymers and tacklfler~. We have dlscovered that such comblnatlon~ contalnlng an amorphous polypropylene exhiblt excellent adheslvlty to untreated polyoleflns and are useful ln varlous pla~tlc fabrlcatlon and a~semblles Involvln~ ~uch surfaces.

SU~MARY O~ TH~ INY~TION
We have found that when a selectlvely hydrogenated monoalkenyl arene/conJugated dlene block copolymer, such a~
a ~electlvely hydro~enated styrene-butadlene-Ytyrene or ~tyrene-lsoprene-~tyrene copolymer, 1~ comblned wlth an amorphou~ polypropylene and a tack~fler, the reYultant adhe~lve exhlblts an unexpected and ~uperlor adheYlvlty to polyolefln ~urfaceY, Yuch as polyethylene and polyprolpylene.
The~e adheYlves have a speclal utlllty ln the fabrlcatlon of a varlety of artrcleY, for example, ln the preparatlon of packaglng fllms, clo~ure~ of wax-coated paper or paperboard boxes, aYYembly of InJectlon molded obJectY and contalner~, some or all of whlch wlll requlre the necesslty for an adheYive uYe to provide the desired fabricated products for varlou~ artlcleY of commerce. Thu~, lt ls ab~olutely neceY~ary that the adheYlve uYed exhlblt excellent adhe~lvlty to ~uch Yurfaces to hold the a~Yemblle~ together through thelr llfetlme of use. Our present adheslves, moreovcr, have an excellent afflnlty to untreated polyolefln surfaceY. It 1Y well known ln the art that polyoleflnY can be rendered adheslve receptlve only after approprlate ~urface treatment 1Y employed, Yuch as vla the uYe of corona dlYcharge, flame or vla plasma. Such approach wllI
obvlously requlre an addltlonal step to lmpart surface bondablllty to polyolefln~, and, hence, any approach to the 1 3`36 626 de~lgn of an adheslve whlch wlll overcome thl~ addltlonal, and co~tly, step, that 19, exhlblt a dlrect afflnlty to untreated polyolefln ~urfaces, wlll be of much Interest and useful to lnduYtry.
The amorphou~ (atactlc) polypropylene~, Includlng amorphou~ polyalphaolefln~, and combInatlon~ thereof, u~ed hereln to prePare the novel melt adhe~lve compo~ltlon~
clalmed hereln wlll ~how varylng extent of ~olublllty ln hydrocarbon ~olvent~, ~uch as pentane, hexane, etc., have a cry~talllnlty of leYs than about 10 welght per cent, preferably les~ than about flve welght percent and pos~ess a molecular welght In the range of about 300 to about SO,OOO, preferably about IOOO to about 25,000. The method u-~ed In preparlng the amorphou~ polypropylene or amorphous polyalphaoleflns and recoverlng the same, ha~ no effect on ItY utllSzatlon ln the preparatlon of the novel melt adheslve clalmed hereln. Thu~, amorphous polypropylene formed as a byproduct ln mlnor amounts durlng the productlon of crystalllne polypropylene (homo or copolymer re~ln~) by the polymerlzatlon of propylene ln the presence of ~tereo~peclflc cataly~ts by proce~e~ dlsclo~ed, for example, ln U.S. Patent~ No~. 3,679,775 to Hagemeyer et al, 3,529,037 al~o to Hagemeyer et al and 3,900,694 to Jurrens can be u~ed. On the other hand amorphou~ polypropylene (amorphous polyalphaoleflns~ produced dlrectly, that 19, by intent, wlthout the productlon of crystalllne copolymers of ~336626 propylene and lowcr olefln~. a~ dl~clo-Qed, for example, ln U.S. Patent~ No~. 3,923,758 to Carter et al, 3,954,697 to McConnell et al, 4,072,812 to McConnell et al, 4,072,813 to McConnell et al, 4,259,470 to Trottcr et al, 4,309,522 to Dletrlch et al and 4,317,897 to Herrmann et al can also be u~ed. Whlle the amorphou~ polypropylenes ~amorphou~
polyalphaolefln~) used hereln can be homopolymers of Propylene~ lt l~ wlthln the purvlew of our lnventlon to uQe ~ub-Qtantlally amorphou~ products based on propylene copolymerlzed wlth oleflns, ~uch as ethylene, butene, pentene, hexene, nonene, decene, etc., whether Quch productQ
have been obtalned lntentlonally or a~ by-products. The latter copolymer~ are deflned hereln aQ ~amorphouQ
Polyalphaolefln~. In the clalmed lnventlon hereln, the term "amorphou~ polypropyleneU l~ lntended to lnclude the sald ~amorphouQ polyalphaolefln~. Such amorphou~
copolymer-Q can have a melt vlsco-Qlty ln the range of about 200 to about 50,000, or even hlgher, Cp-Q at 375F ~190.5C) ~ASTM D 3236). The~e copolymers will contaln propylene ln an amount ranglng from about 25 to about 99.5, or even hlgher, welght percent, generally from about 50 to about 99.5, or even hlgher, welght percent, wlth the remalnder belng one or more of the other oleflns Identlfled above.
The amorphou-Q polyalphaolefln~ u~eful hereln are further deYcrlbed, for example, ln U.S. Patentq No~. 4,022,728 to Trotter et al, 4,120,916 to Meyer et al, 4,210,570 to _5_ ~336626 Trotter ct al, 4,2~4,756 to Trotter et al and 4,2B8,358 to Trotter et al.
The block coPolymer used hereln to prepare the novel melt adheslve compo~ltlon clalmed hereln can be elther a multlblock copolymer contalnlng the structure A-B, the structure A-8-A1 or the radlal structure (A-B)XY, or comblnatlons thereof, wherein A and Al, the same or different, are alkenyl arene polymer blocks, preferably monoalkenyl arene polymer blocks, B ls a block contalnlng a hydrogenated conJugated dlene polymer, preferably a block con~l~tlng e~sentlally of a hydrogenated conJugated dlene polymer, Y repreYents a resldue of a polyfunctlonal coupllng agent or a polyfunctlonal lnltlator and x 19 a number havlng a value greater than 2, preferably from 3 to 4. The geometrlcal structure of the block copolymer~ u~ed hereln 1 not crltlcal, a~ long as the A, A1 and B components thereof fall wlthln the above deflnltlon, and therefore the structure can be elther llnear ~lncludlng tapered), radlal or branched. Each of the blocks A, A1 and B can be substantlally homopolymer or random copolymer block~, as long as at least about 50 welght percent, preferably at lea~t about 75 welght percent of each block predomlnates ln at least one clas~ of the monomers characterlzlng the block~
and the A and A1 blocks lndlvldually predomlnate ln alkenyl arenes and Block B lndlvldually predomlnates ln a hydrogenated conjugated dlene.

The term ~alkenyl arene~ can be any alkenyl arenc havlng from 8 to 18 carbon atons, preferably from 8 to 9 carbon atom~, and can lnclude ~tyrene lt~elf and lts analogs and homologs, for examplc, alpha methyl ~tyrene and rlng-substltuted styrene, such a~, rlng alkylated styrenes, for example, 3-methY1 styrene, 4-methyl ~tyrene, 4-n-propyl ~tyrene, and other alkenyl arene~, such as 1-vlnyl naphthalene, 2-vlnyl naphthalene and the llke. Styrene and alpha methyl styrene are preferred, wlth ~tyrene belng e~peclally preferred.
The term ~conJugated dlene~ 1~ lntended to lnclude a conjugated dlene havlng from 4 to 8 carbon atoms, preferably from 4 to 6 carbon atom~, such as 1,3-butadlene, lsoprene, 1,3-pentadlene, 2,4-hexadlene, 3-ethyl-1,3-pentadlene and the llke and copolymer~ of ~uch conJugated dlenes, provlded that ~uch copolymer ls characterlzed by such conJugated dlene and ~uch copolymer contaln~ at least about 50 welght percent, preferably at least about 75 welght percent, of such conJugated dlene. When the block copolymers deflned above, A-B-A1, A-B or (A-B)XY, are ~electlvely hydrogenated, for example followlng the procedure deflned ln U.S. Patents No~. 3,595,942 to Wald et al and 3,696,088 to DeVault, block~ A and A1 are ~ubstantially unaffected by the hydrogenatlon but at lea~t about 75 welght percent, generally all, of the conJugated dlene polymer ln block B 19 converted to the corre~pondlng hydrogenated ~pecleY. Thu~, when block B l~ compo~ed of polybutadlene the rc~ultlng block l~, or at lea~t appears to be, a copolymer of ethylene and butene-1 ~EB). When block B l~ compo~ed of l~oprene, the re~ultlng block l~, or at lea~t appear~ to be, a copolymer of ethylene and propropylene ~EP).
Typlcal block copolymers that can be u~ed Include the followlng:
(1) poly~tyrene-hydrogenated polybutadlene-polystyrene, ~2) polystyrene-hydrogenated polyl~oprene-poly~tyrene, (3) poly~alphamethyl~ styrene-hydrogenated polybutadlene-poly~alphamethy~) ~tyrene, (4) poly(alphamethyl) ~tyrene-hydrogenated polyl~oprene-poly~alphamethyl) ~tyrene, ~5) poly~tyrene-hydrogenated polybutadlene, ~6) polystyrene-hydrogenated polyi~oprene, ~7) poly(alphamethyl) ~tyrene-hydrogenated polybutadlene, ~8) poly~alphamethyl) ~tyrene-hydrogenated polylsoprene, (~) polymer~ of the conflguratlon (A-B)xY, whereln A
repre~ent~ poly~tyrene or poly(alphamethyl) ~tyrene -~egment~, B repre~ents a hydrogenated polybutadlene or polylsoprene ~egment, Y repreYents a re~ldue of a polyfunctlonal coupllng agent or a polyfunctlonal lnitlator and x 19 a number havlng a value greater than 2, preferably from 3 to 4, ~10) comblnatlon~ of the above in varlou~ proportlcn~, etc.
The average molecular welght of the lndlvldua~ polymer block~ A, A1 and B can vary over a wide range. The total average molecular welght of the alkenyl arene block~ can be ln the range of about 2000 to about 125,000, but preferably wlll be ln the range of about 5,000 to about 50,000. The 1 3366~6 ~electlvely hydrogenated conJugated dlene polymer block wlll have an average molecular welght ln the range of about 10,000 to about 500,000 but preferably wlll be In the range of about 20,000 to about 300,000. The block copolymer~ u~ed hereln wlll contaln a total from about flve to about 50 welght percent of the alkenyl arene block(~), preferably from about 10 to about 35 welght percent.
Examples of the block copolymer~ that can be used hereln are further deflned ln U.S. Patent~ No~. 4,151,057, 4,286,077 and 4,296,008 to St. Clalr et al, and ln U.S.
Patent No. 4,138,378 to Do~ dlYcu~ed herelnabove.
The thlrd nece~ary component ln preparlng the novel melt adhe~lve compo~ltlon~ clalmed hereln ls a hydrocarbon tacklfler. Sultable for such u~e can be any hydrocarbon tacklfler, or comblnatlon~ thereof, generally u~ed, or sultable for u~e, ln the preparatlon of hot melt adhe~lve~.
A partlcularly ~ultable tacklfler can be obtalned from commerclally avallable hydrocarbon resln~ re~ultlng from the polymerlzatlon of monomer~ con~lstlng of olefln~, cycloolefln~ and dlolefln~, for example, re~ldual byproduct monomers re~ultlng from the manufacture of l~oprene. Such tacklfler~ are de~crlbed, for example, ln U.S. Patent No~.
3,932,330 to Lak~hmanan, 4,022,728 to Trotter et al and 4,072,735 to Ardemagnl. Such petroleum-derlved hydrocarbon resln~ are ~ometlme~ al~o referred to a~ ~ynthetlc terpene re~lns. Other type~ of tacklfler~ also ~ultable for u~e hereln Include product~ obtalned from cyclopentadlene and dlcyclopentadlene polymerlzatlon and subsequent hydrogenatlon, conventlonal terpene reslns and modlfled terpene reslns obtalned as a result of the polymerlzatlon of such terpene-~erlved monomer~, such a~ alpha- and beta-plnene, dlpentene and llmonene, rosln and rosln e~ters, hydrogenated roYln product~ and dlYproportlonated rosln products. Petroleum hydrocarbon reslns that have been post hydrogenated to yleld a more thermally stable resln are especially preferred. The tacklflers uYed to prepare the novel melt adheslve compoYltlons clalmed hereln wlll typlcally exhlblt a rlng and ball softenlnq polnt (ASTM E
28~ ln the range of about 10 to about 150C, preferably about 25 to about 125C.
The three components requlred to obtaln the novel melt adheY5ves clalmed hereln can be present In the amounts defIned below In Table I.
TA~r.~ I
Welqht Percent Preferred BroA~ RAnqe R~nae (1) Amorphous Polypropylene5 - 95 30-90 ~2) Selectlvely Hydrogenated Block Copolymer 2.5 - 40 5-20 ~3) Hydrocarbon Tackifler 2.5 - 55 5-50 In an embodlment hereln our melt adheslves can have also Incorporated thereln lYotactlc polypropylene, ethylene-propylene copolymers, homo and copolymers from ~36626 butene-1, paraffln and mlcrocrystalllne waxes, Flscher-Trop~ch waxes, low molecular welght polybutenc~, polylsobutylene, low molecular welght ~700 to 25,000) polyethylene, conventlonal low denslty polyethylene, proce~
ol 19, etc., in an amount upto about 40 welght percent, generally upto about 25 welght percent, ba~ed on the flnal adhe~lve composltlon.
Slnce hot melt adhe~lve~ tend to experlence varylng degree~ of thermal expo~ure durlng thermal proces~lng and/or durlng appllcatlon to the sub~trate, lt S~ deslrable to lncorporate thereln one or more antloxldants ln small amount~ to lnhlblt thermal and/or thermooxldatlve degradatlon. Several type~ of commerclal products, predomlnantly of the hlndered phenol type~, are avallable for thls purpose to function as prlmary antioxidants. A
~econdary antloxldant belonglng to the general classlflcatlon of thloe~ter~ and phosphltes can also be used ln comblnatlon wlth the hindered phenols. Exemplary of antloxldant~ sultable for use hereln lnclude tetrakl~tmethylene 3-(3',5'-dl-t-butyl-4-hydroxyphenyl) proplonate] methane;
2,2'-ethyldenebi~(4,6-dl-tertlary-butylphenol);
1,1-3-trls~2-methyl-4-hydroxy-5-t-butyl phenyl) butane; and 1,3,5-trlmethyl-2,4,6-trls(3,5-tertlary-butyl-4-hydroxybenzy 1) benzene. Secondary antloxldants, such as dllaurylthlodlproplonate; pentaerythrltol tetrakis(beta-laurylthloproplonate) and various alkyl-, aryl-, di-and polyphosphites and thiophosphites can also be employed in combination with appropriate hindered phenols. Effective amounts of antioxidants that can be used can range from about 0.05 to about five weight percent, preferably from about 0.1 to about 2.5 weight percent, based on the weight of the final adhesive composition.
The preparation of the novel melt adhesive claimed herein is not critical and any suitable method can be employed. In a preferred embodiment a mixing vessel is heated to an elevated temperature, for example in the range of about 350 to about 400 F
(162.8 to 204.5C) and the amorphous polypropylene, tackifier and the antioxidant, if used, are added thereto. The resulting mixture is allowed to soften under slow mixing to homogeneity. At this juncture the block copolymer is added in small quantities to the melt with continued mixing until the entire amount is added.
Following this mixture is further continued with homogeneity of the entire adhesive mass occurs. After this the product is collected in a release line tray. The total mixing time is generally in the range of about two to about four hours.
Accordingly, the invention herein comprises a melt adhesive composition especially useful in adhering polyolefin bodies to themselves, to other polyolefin bodies and to other non-polyolefinic bodies consisting of:
A) from about 60 to 99.95 weight percent of a mixture consisting of an amorphous polypropylene, a selectively hydrogenated block copolymer selected from the group ~, consisting of styrene-ethylene/butene-1 block copolymers and styrene-ethylene/propylene block copolymers and a hydrocarbon tackifier, wherein said amorphous polypropylene has a crystallinity of less than about 10 weight percent and a molecular weight in the range of about 300 to about 50,000 and said hydrocarbon tackifier has a ring and ball softening point in the range of about 10 to about 150C; the above components being present in the following relative amounts:
Weiqht Percent Amorphous Polypropylene 5 - 95 Block Copolymer 2.5 - 40 Hydrocarbon Tackifier 2.5 - 55 (B) from about 0.05 to about 5 weight percent, based on the weight of the final adhesive composition of an antioxidant; and When (A) and (B) comprise less than 100 weight percent of the adhesive composition, (C) a compound or a mixture of compounds selected from the group consisting of an isotactic polypropylene, ethylene-propylene copolymers, paraffin and microcrystalline waxes, Fischer-Tropsch waxes, low molecular weight polybutenes, polyisobutylene, low molecular weight polyethylene, low density polyethylene and process oils of not more than 39.95 weight percent based on the weight of the final adhesive composition.

- 12a -13~6626 D~CRIPTION OF P~F~RR~n ~RO~ IM~T~
The present Inventlon relatlng to the novel hot melt adheslve~ clalmed hereln can further be Illustrated by the followlng. A number of composltlon~ were prepared elther u9 I ng an oll-heated Brabender mlxlng vessel havIng a compoundlng bowl wlth a capaclty of 450 mllllllters or u~lng a ~talnleY~ steel beaker heated wlth a GLAS-COL mantle wlth a capaclty of 500 mllllllter~. Before beglnnlng, the Brabender mlxlng ve~el wa~ heated to a temperature ranglng from 350F (176.7C) to 380F (1~3.3C). The amorphou polypropylene, tacklfler and antloxidant were allowed to ~often and were mlxed at Yuch temperature under ~low mlxlng for 30 mlnute~. When the preparatlon was carrled out ln a ~talnle~s ~teel beaker, ~ufflclent amount of the amorphous polypropylene and tacklfler, along wlth sufflclent antloxldant, were placed ln the contalner and the entlre ma~ wa~ ~lowly heated to the de~lred temperature. At the polnt of fluldlty of the melt, ~low ~tlrrlng commenced to brlng the maYs to homogenelty. In both mlxing approacheY
followlng homogenlzatlon, the block copolymer wa~ ~lowly added ln ~mall quantatle~ under contlnuou~ mlxlng untll the deslred homogenelty of the mlxture wa~ obtalned. Total mlxlng tlme ranged from about two to about four hour~. The mlxed composltlon~ were then collected on a relea~e llne tray.

The thermal ~tabllltles of the adhe~lve composltlons that were prepared were determlned by exposlng 8 to 10 grams quantltles of a sample ln a fIve-lnch x one-Inch te~t tube to a temperature envlronment of 350F (176.7C) for 24 hours. At the end of the 24 hours, the composItIon was vl~ually ob~erved for any ~eparatIon stratlflcatlon and 109 In composltlon homogenelty. The ring and ball softenlng polnts of the composltlons were determlned accordlng to ASTM
Procedure E-28. The melt vlscosltles of the composltlons were determlned accordlng to ASTM Procedure D 3236. The Peel Adhe~lon Fallure Temperature ~PAFT) and Shear Adhe~lon Fallure Temperature ~SAFT) were performed accordlng to TAPPI
Procedure T814-77; and the peel Ytrength values were determlned accordlng to ASTM Procedure D 1876.
A Slautterback ~mlnl~qulrt" hot melt gun applIcator was used to prepare the peel strength, 180 reverse pee~
strength, PAFT and SAFT speclmens to test the hot melt adheslve compo~ltlons of thl-~ lnventlon. To determlne peel strength values of these composltlons, polyethylene lamlnated test speclmens were prepared by applylng the molten hot melt adheslve composltlons at 350F (176.7C) to a 4-mll ~one-lnch by six-lnch) hlgh denslty polyethylene fllm as a contlnuou~ strlp one lnch wlde along the Cllm of 2 1/2-lnch length, and then another 4-mll hlgh denslty polyethylene fllm of the same dlmenslon~ was placed on top of the fllm carrylng the strlp of the hot melt adhesive composltlon. Enough contact pre~sure was applled vla a rubber roller to ~pread the adheslve and to brlng the adheslve ln lntlmate contact wlth the ~urfaces. The lamlnates were then aged for a mlnlmum of 24 hour~ prlor to testlng. Three speclmens for each composltion were prepared and the bond ~trength was mea~ured by peellng at the glue llne by means of a J. J. Lloyd Tenslle Tester at a peel rate of 50 mllllmeter~ per mlnute. The maxlmum force ln gram~
nece~sary to cau~e rupture of the bond wa~ noted. The average of the three such determlnatlons wa~ recorded.
To obtaln the 180 degree~ rever~e peel ~trength value~, three-mll Mylar fllm/180-mll hlgh den~lty polyethylene and three-mll Mylar fl1m/120-mll polypropylene lamlnated test ~peclmen~ were prepared by applylng the molten hot ~elt adhe~lve composltlon at 350F ~176.7C) to elther 180 mil (one-lnch by slx-inch) hlgh denslty polyethylene substrate or 120 mll (one-lnch by ~lx-lnch) polypropylene substrate as a contlnuous strlp one-lnch wlde along the substrate length and then a 3-mll (one-lnch by 12-lnch) ~trlp of Mylar fllm was placed on top of the substrate carrylng the strlp of the hot melt adhe~lve compo~ltlon. Three a~Yemblles of each were prepared for each adheslve valuatlon. Followlng thls procedure enough contact pressure wa~ applled vla a rubber roller to ~pread the adheslve evenly and to brlng the adhe~lve ln lntlmate contact wlth each of the surfaces. The lamlnate~ were then aged for 24 hours prlor to te~tlng.

~336626 Testlng procedure~ were the ~ame aY for the polyethylene speclmens.
To determlne Peel Adheslon Fallure Temperature (PAFT) and Shear Adhe~lon Fallure Temperature (SAFT) value~ of the hot melt adhegIve comPo~ltlons. 78 Pound (one-lnch by slx-lnch~ kraft lamlnated test paper was u~ed by applylng each of the composltion~ to the kraft strlp by means of a Slautterback Umlnlsqulrt~ hot melt appllcator. The hot melt adhe~lve composltlon-~ were applled at 350F (176.7C) to the kraft paper as a contlnuous coating of one-lnch by 2 1/2-lnch area of the kraft ~ub~trate for PAFT performance and of one-lnch by one-lnch areas of the kraft ~ubqtrate~
for SAFT performance. Then another 78 pound kraft paper strlp of the ~ame dlmenslon waY placed on top or positioned longltudlnally on a kraft paper carrylng the coatlng of the hot melt adheslve composltlons. Sufficlent contact pressure was then applled to brlng the adheslve lnto Intlmate contact wlth the ~urface~. The lamlnate~ were then aged for 24 hour~ prlor to testlng. Two or three ~peclmens for each compo~ltlon were prepared. The test was carrled out by exposlng the assemblle~ ln an oven conditloned at 100F
(37.~C). The specimens were su~pended at one end In the oven to a sultable devlce (a paper cllp), whlle to the other end elther a 100-gram load (PAFT te~t) or a 500-gram load (SAFT test) were attached. From thls polnt on, the temperature of the oven wa~ lncreased programmatlcally at ~336626 the rate of 10F ~5.5C~ every 15 mlnutes untll the fallure temperature wa~ reached. The average fallure temperature was then recorded.
The component~ u~ed In the preparatlon of the adhe~lve composltlon~ are ldentifled below ln Table II.

~ 336626 u r~ ~
U- U U~ ~ U rJ U U U
n n - ,, , .3 ......... __~3 ~n~__C~nmr~r-r r r ~ r V V V V ~. V V V V ~, v oooe~o ^O
^5~C~o^ ~ ...........
r ,~ G ~ ^ O ~_ i v v v v ~ v v v v v u _ ~ - r~ . rr n G O G O O O O O O G O
r_ _ ~- ~ ¢ Ir r~ 0 rJr U~ 0 rL rD rJ~ rn rn r~ r~
_ ___________ mmmmGmmmmmm ' ' -' J J J ~ d - .25 ~ d ~ d .25 d ~;
1 ~
C C O D O O r o D ~ r mnr~cr Gr~
N - N n - r~ r r~ rr C rr rr m rr r~ rr n n _ _ o N r~ O O ~ r,~ _ _ _ _ ~t O
o n ~ 0 C~ ~ r~ ~-r _--~_ o rD n ~r rn rlr O C
C n n ~
-- L O O m O r!~ m C~ a nm ~ -v r C ~ ~ r r r . _ _ _ L --O ., 1. -r O O O -- _ -- --J r ~ . v. . ~ . . ~ U u U -a ~ L u L, L ~ . U U U L Lo ~ S
Y `-: Y Y Y Y : L I (L rL rL rL IL IL
y o V
J U ~
_ _ _ _ _ _ _ _ _ _ U UU~ UUrrUUUUUU
E C E U IE
L ,c, c c ~ ~1 U UU' U U ~ - -._ _ _ _ _ _ _ _ _ -- -- _ _ _ _ _ O O U . L L . L L .
3 iD D rD rD m rn m I J U ~ ~ . S ~: .

L L ~ --_ _ ~ C ~r o o ~' ~ r~'; C C ~ I r~
L L r~ r~ _ v L L ~ 0 0 - r I rr ~ ~ . u L I E r U U L W
~ Y Y E - - c C
-- -- O O u u ~ _ ~ _ o O o~ r~ 0 0 _ u . ~ ~
g o~ ~ m ~- . U . ~ rLo ~ c u U O _ ~~
~ Y 2 rr U ' ' ' ^
0 O -- -- rD rn U L l; C . --- -- r~ rll O , V, L ~D rrl ~ ~ __ , E U~ UJ
~ I I o r r.~ U CL u ~ ~ - ,~ _ _ _ i m r~ ~D ro n c~ n rn ~ u m ' ~ c C

TA~LE II(Contd ) Ll-t Of R-w ~-t-r~ Contd ) _ _ _ _ _ _ _ _ _ P-r-f~tn W-~ 6h-11 Ch~mlc-l 5h-11w-~ ~00 ~-lt Polnt 161 F ~0~ 65 C) Amorphou- Polypropylon- LAmorphou- Poly-lph~ol-~ln A~ phou- Polypropyl-n- D~ych-n K-TAC 100 Vlsco-ity D 1~5 F ~190.S C ), 2SC~ cps A-- ~hoo- Polypropyl-n- e~ych-m K-TAC IOOA Vi-coslty D l~S F ~190 S C ), eso cp~
A pho~- Polypropyl-n- Daych-m K-TAC 100~ Vi-co-ity D 17S F (190 S C ), 1401) cp~
~ ~ ph~u- Polypropyl-n- H-ych-m K-TAC IOOD Vl-co-ity D 17S F ~190 S~C ), 2H00 cp -Amorphou- Polypropyl-no 8aych-m ~-TAC 400 Vl-co-lty D 17S f (190 5 C ), 10,000 cp-A~orphou- Polypropyl-nw E--tm-n Ea-tobond ~-SC Vl-co-lty D l~S F (19C~ S C ), l~SO cp-A~orphou- Polypropyl-n- E--tm-n Ea-tobond ~-5H Vl-co-lty a ~S F ~190 5 C ), 200C~ cp~
Amorphou- Poly-lph-ol-~ln El P--o P~oduct- Co R-~tac PlPI~ Vi-co-lty D ~ F ~190. S-C ), 1~00 Cp-Amo-phou- Poly-lph-ol--ln El P--o Product- Co R-~tac H~DlS Vl~co-lty D ~S F ~190 5 C ), ~9 Cl rp~
I Amc~rphou- Poly-lph-olmfln Huls V~-topl-~t SO~ Vluco-lty D ~ F (19f~ S C ), ~HI~H cp~
Amorphou- Poly-lph-ol- ln Hul- V--topl--t ~oe Vl-co-lty D ~75'F (190.5'C ), ~200 ~p~
A~orphou- Poly-lph-ol-~in Hu~- Vn-topl--t ~01 Vl~coslty O S~S F (190 C ) , 2SOO cps Amorphous Poly-lph-ol-~ln Hul- Vcstopl--t V1~41 Vl-co-lty 0 llS F ~190 C ) , ~40~ cps Antio~ld-nt ____________________.____ U~nd-r-d Ph~nol Sch~n-ct-dy Ch-nic-l- I~ono)~ 129 ~-lt Polnt 1~2 C
Dil-u yl thiodiproplon-t- ~DLTDP) Ev-n~ Ch~m-tic- DLTDP ~lt Point 4~ C

1~3 1 3~6626 Data obtalned ln a ~erle~ of run~ are ~et forth below ln Table III.

TAeLE 111 DAgE RUN5 Run d 1 2 ~ 4 ~ h 7 ___________ ____ ________ ____ ____ ____________ PARTS ~Y WEIGHT, ~RA~

APP, K-TAC 100~ 100 00es 00S~ 00S~ 7S 7S 00 - - S(l 00 ~h-llw-~ ,00 - - - - - 47 SO - -Kr-ton ~X-IhS7 -IS 00IS 007 50 7 SO S 00 9 S~
E~cor~ s~eo - -lS OO3e 7S l7 SO 47 50 9n 4e Winqt-ck 10 - - - - - - - SO ~X
l-ono~ 12~ / DLTDP~1~1) 0 hO 0 h O ~0 O bO 0 hO O hO O hO 1~ h~
Tot-l IOO h100 h100 ~100 h100 h ,Inl h 100 h IOO h Propnrtl--V~co-lty, cp~ ~ ~SO F2000IOSOO9~S0~00 4300 41~140n 2,S
R~e,~C IS4 IS~ 1~9 149 IS~ e9 9~ 14-P-r~orm-nc-_ _ _ _ _ _ _ _ _ P--l 5tr-n~th, ~/in, SO mm/min H W E (4 mll~ HDPE ~4 mill9S0104S 4400 31~0Ih~ONo Adh Nn Adh ~311 ~yl-r~ mill/PP ~120 mll)IsnoIhO4090 h240 2eel:,No AdhNc~ Ad~1 ~h~

r~
O~

An lnspectlon of the data ln Table III ~how~ that when amorphous polypropylenc 19 used alone as an adheYlve ln Run No. 1 ~ome level of adhe~lon ls obtalned to hlgh denslty polyethylene (HDPE) and polypropylene (PP) ~urfaces. When amorphous polypropylene wa~ comblned ~olely wlth a selectlvely hydrogenated block copolymer composed of styrene and ethylene butylene polymer blocks ~Kraton GX-1657) ln Run No. 2, no appreclable Improvement ln adhe~lon to a HDPE
surface was achleved and adheslon to polypropylene wa~
slgnlflcantly reduced. When the same -~electlvely hydrogenated block copolymer was comblned solely wlth a tacklfler ln Run No. 7 no adheslon at all was obtalned.
When In Run No. 8 amorphou~ polypropylene was com~blned ~olely wlth a tacklfler, the results were lnferlor to Run No. 1. The u~e of Kraton GX-1657, a wax and a tackifier, but no amorphou-~ polypropylene, ln Run No. 6 resulted ln a compo~ltlon exhlbltlng no adheslv1ty. Note, however, that ln Run~ Nos. ~, 4 and 5, whereln an adheslve contalnlng the selectlvely hydrogenated block copolymer Kraton GX-1657, amorphous polypropylene and a tacklfler was tested, unexpected and dramatlc lmprovements In adheslve performance was obtalned In both HDPE and PP urfaces.
An addltlonal ~erles of runs wa~ made and the data obtalned are set forth below ln Table IV.

Tl~LE I V
E~ ct 0~ Componmnt L-v-l- On Ell~nd P-r~orm~nc-RLIN 1~ 9 10 11 12 1~ 14 ___________ ____ _____ _____ _____ ______ _____ PART5 13Y WE I 13~T, (3RAI~IS
APP, K-rf~C lOOe 40.00hO.10 73.0020.0045,0C1 47,50 Kr--ton OX-lb57 20.01)13.30 9.0040.00IO.C~I:) 5.~-0 E-cor-~ 5~eo 40,1~02h.hO113.00 40.1)1:)4~,n~:~ 47.Sn I-ono)< 129/ DLTDF 1111~ O~hOO.hl) C~.hl) O.hl) o.e":~ O.hm TOe~l 100.~1~)0.~100.~ 100.~-100.
Pr-np--r t i v _ _ _ _ _ _ _ _ _ _ t~ Vl-co-ltv, cp- 11 :~50 F14S00 75004~50e5X~ 3h50 IhS~
R~ C 110 152 131 1241~1414~3 P-r~or m-nc-P~--l 5tr--n~t~ /In., 50mm/mln.
HDPE(4 mil~ DPE(4 mill 5790 397021eO 272~~.200~2~5 ~1yl--r ~1 mll~XPP (120 mll~104~477()2970 ~4mo122~095~0 ~1 C~
r~

The data ln Table IV clearly ~how~ that a hlghly slgnlflcant lncrease ln adheYlon to both HDPE and PP
~urface~ 1~ obtalned even though the amount-~ of amorphou~
polypropylene, selectlvely hydrogenated block copolymer and tacklfler are varled over a wlde range.
Stlll another ~erles of runs wa~ made and the data obtalned are ~et forth below ln Table V.

n c I I I ! I I I I I n ~ ~. g n ~i r ~ n r - ~ ~ 8 ~ ~t _ r o 5 C O -C - m r. ~
.. . . ~_ ~'I -- ~ 8 ~ n ~

t'~ C C 5 C 8 ~ ~- G ~t n ~ n I 1 8 n ~
. . . ^ - ~r m ~ n r c .~ _ a 8 -- O O O ^~ 8 C t~: Q O
~ nc I ! I I I I n I I I ~ . n~ nc t n ~ o g " n $
~ _ ', _ _ _ ~ n cO; ~ I I I I n I I I 1 8 n m n Q
0 r; n ~ 5 0 - n n ._ ~
L 1~_ O oO o o 8 0 r- O O
~ ~ .. . . o al-- o ~t r n r Q O _ _ m 3 > ~ m i^ cC I ~ ~ n I I I I I I ~ . o n n r-0 ~ n ~ O c ~ n ~
c c t_ O O o 0 8 0 t~- O O
~, - n o I I n I I I I I ~ 0 ~ n t~
r n r o o r ~ n n y _ 0 8 ~ I 0 8 3 n ~ ~ ~ _ w n ' n g n I I I I I I I I ~ 8 8 5 ni n O g ~ n r~

n _ c 1~
o C
n wm n x ~L ~
m n n ~ x on ----C a ~ c~-~ t-- C o, _ _ _ --n ~ u~ 0 C~ Q Q ~ u 1~ E
~ t- n 2 i ~ r ~ O u V ~ X n - - . -o o ~ o o o _ _ _ _ . o _ o ~ w ~ u ~ u u u ~ c ~ . u U U U U ~ O' o O . U ~ O

A~ ~ecn from Table V, the adheslon obtalned In each of Runs 15, 17, 18 and 20 to 24 19 stlll extremely hlgh when the amorphous polypropylene and the block copolymer are comblned wlth a varlety of tacklfler~. Although ln Runs No3. 16 and 19, the adheslvlty to HDPE and PP ~urface~ wa~
low, about the same order a~ obtalned ln Runs Nos. 1 and 2, lt ~hould be polnted out that Runs Nos. 16 and 19 should be compared, however, wlth Run No. 8 ln Yhowlng that the presence of all three components, namely, amorphou~
polypropylene, the block copolymer and a tacklfler, mu~t be present to obtaln an lmproved adheslvlty. For example when approxlmately equal amounts of amorphou~ polypropylene and a low ~oftenlng polnt tacklfler alone were used ln the preparatlon of the adheslve ln Run No. 8, adhe~lvlty to both HDPE and PP surfaces was extremely low. When, however, ln Runs 16 and 19, a small amount of the Kraton GX-1657 selectlvely hydrogenated block copolymer was added to approxlmately equal amounts of amorphous polypropylene and a low ~oftenlng polnt tacklfler, slgnlflcantly lmproved adheslon to both HDPE and PP wa~ achleved ln comparl~on to Run No. 8.
Yet another serles of runs was made. The data obtalned are ~et forth below ln Table VI.

r ~ n n --r ~ -- rl rl; o ~ _ ~ o iD
r ~ r I ~ ~C , "t n n ~
o r ~o o ~ ~ ri r, ~ r~ ~

n ~ ~ n n ,0~ t ~ 8 1 1 I n ~ ~ ~
ilt i'- G O '~ -- i m ~ ~ _ w -~ I o n n r ~ ~ o r, o ~t r~ O n n ~

n ~- O iD I ~ O O ' - ~ ~ "
>r~ I inI -- I I I ~ I I I ~1 ~ O O n _ r w ~o o ~ o :i ~ n ~
~ ~I --~ _ r~
iD-- ~r ~ C
,~ ,!I n ~ ~ O, ~ ~ "~ ~0 ~ ,~ rn n O O i~t - n '~
~ ~ _ ,.
o ~ I o o . o ~ oo ~a i~ II n I o I I I I I ,n ~I . n n ~ I ~ _ _ D z U

N ,! ~ _ n,,,,,, ~, $ ~ n n n O i ~ ~ o g N-- --n ~ -- N _ _ -~, n ` 'a m _ c~ s o 3 ~n~ ~ i o c c~
u u _ - _ _ I I _ n ~ i11 . _ ~
I n r~ u ~; iE n o ~t ~ -t 2 -; i~ o ~ U ' --t C ~ ~' 110 ; _ ~ 11 S ~

~3366~Zb The data ln Table VI exempllfy the crltlcal need of comblnlng the amorphous polypropylene and tacklfler wlth a ~electlvely hydrogenated alkenyl arene/conJugated dlene block copolymer to obtaln an adhe~lve havlng Improved adhe~lvlty to HDPE and PP surface~. In each of Runs No~. 25 and 26, whereln the mldblock lsoprene and butadlene polymers were not hydrogenated, poor results were obtalned. However, ln each of Runs No~. 27 to 33, whereln varlous types of selectlvely hydrogenated elastomers of varylng mldblock characterl tlc~, styrene level~ and molecular welght~ were u~ed, excellent adhe~lvltle~ were obtalned.
A further ~erles of run~ wa~ made and the data obtalned are ~et forth below ln Table VII.

TAE~LE V I I
In~lu-nc- Of ApP Typ- On el-nd P--rform-nc-RLIN ~ SS Sh ~7 ~13 S9 40 41 ___________ __________ __________ _____ ._____ .____ _____ PARTS E~Y WE I GHT, GRA~1S

~PP, K-T-c 100 47.SO - - - ~0. 10 - - --APP, K--T--c 100 ~ --47 50 hO. 10 APP, K--T--c IOOD ~ ~ 47-5~ 0. 10 AP~, K-T--c 400 ~ ~ ~ 47-50 hO. 10 vr~ton OX-lh57 ~S.OOS.OO~5.00a.oo ~ ol~.~c) 1~
E~cor--~ sseo 47. 5047. S047. 30 47. 50 2~ ) 2~ C1 2~ 0 2t~. bC
l~ono~- 12Y/ DLTDP ~ I I )O. ~,0O. ~0O. hOO. hOO. hOO. bOO. bC~ O. hl:-Tot--l 100.~lOO.hII:IO.h 100.~100.~IlXO.h lOO.h IC
Pr op--r t 1~
_ _ _ _ _ _ _ _ _ _ Vi~co~lt~,cp-- O 1150 F hOO 1150 2S25S550~000SOOO 9e,7s -`425R 1l- e- c 14S140 14h IS2 1~ 14~1~S2 15 P-r orm-nc-_ _ _ _ _ _ _ _ _ _ _ P----l Str--n~tl~, ~XIn., 150mm/min.
~Df'E ~4 ml 1 ~ X ~DPE ~4 ml I ~59005hHOSh80 ~54444540522054~iO 44~0 r ~,1 r ~ ml I \ X PP~120ml I )~elO 7720E~17C11 I~H~ 499C~ 499C~ ~5220 hYaO

1 ~3k626 Run~ No~. 34 to 41 ln Table VII ~how that excellent result~ are obtalned hereln u~lng amorphou~ polypropylene~
over a wlde molecular welght range, that 19, vlscosity, whlle varylng the amount~ of the components used.
An addltlonal ~erle~ of run~ wa~ made. The data obtalned are set forth below ln Table VIII.

, o ~~ ~ ~ _ .
t r c~ l ~ oo ~ ~ ~
n ~ r c n~ ~ ~0 m; ~ r~
cI c ~t m I ~ I n I ~ n I ~ i - r1 ~-t- n t- ~s c _ a r-t~ ~t t C~
~- I ^c c ~I -m ^ -e t I I I i I I n I I .^ n I ~ . n ~ ~ r~
n ~t ; t- r! r-_ _ ~
~ ~ I G O C O ~1 5 t~ O Q
n I I 1 5 n I a . n ~
tD t~ n r o o ~ ~
m . ~
~_ ~ 3 n I ~ n i l l l 8 n i ~ ~ n - ~ .o tN
n t~ - r~ ~
tL
t I 0 55 0 ~ sn m~
~t I I I 11'~ 1 1 1 1 I G n I ~o . n n t~ o 8 tD-- n o u n I o 5C C~ ~ c~n n~
C ~t I I n I I I I I I c n I ~ . n ~ _ m n t- 5 5 N n --t~ I g l l l l l l l o n I ~ 8 ~ cm r n r ~ 5 n m ~m ~t In --lL
rn ~ ~C~ m g 1` ~ I I n n n o ~ ~ G L ~ -rr-n~o~ u e o . . m~-n-~ ~ . u c_ - n ~ n ~ ~ ~ c ~ ~ u ...... u u c L S . r'- ~ tn- -O 1. _ O -- t C a, C L l -2 ~~ ~ cG u ~ _ ~, _ t~ L~ C ~ ; a r ' ~ ~ r ~ ~662f) Run~ No~. 42 to 50 In Table VIII ~how that excellent result~ are obtalned whcn the adheslve hereln 19 prepared uslng varlou~ amorphous polyalphaoleflns obtalned from thc polymerlzatlon of propylenc wlth varlous other alpha oleflns ln place of amorphous polypropylene.
Obvlously, many modlflcatlons and varlatlons of the lnventlon, as herelnabove ~et forth, can be made wlthout departlng from the ~plrlt and ~cope thereof and therefore only such llmltations should be lmposed as are lndlcated ln the appended clalms.

Claims (18)

1. A melt adhesive composition especially useful in adhering polyolefin bodies to themselves, to other polyolefin bodies and to other non-polyolefinic bodies consisting of:
(A) from about 60 to 99.95 weight percent of a mixture consisting of an amorphous polypropylene, a selectively hydrogenated block copolymer selected from the group consisting of styrene-ethylene/butene-1 block copolymers and styrene-ethylene/propylene block copolymers and a hydrocarbon tackifier, wherein said amorphous polypropylene has a crystallinity of less than about 10 weight percent and a molecular weight in the range of about 300 to about 50,000 and said hydrocarbon tackifier has a ring and ball softening point in the range of about 10° to about 150°C; the above components being present in the following relative amounts:
Weight Percent Amorphous Polypropylene 5 - 95 Block Copolymer 2.5 - 40 Hydrocarbon Tackifier 2.5 - 55 (B) from about 0.05 to about 5 weight percent, based on the weight of the final adhesive composition of an antioxidant; and When (A) and (B) comprise less than 100 weight percent of the adhesive composition, (C) a compound or a mixture of compounds selected from the group consisting of an isotactic polypropylene, ethylene-propylene copolymers, paraffin and microcrystalline waxes, Fischer-Tropsch waxes, low molecular weight polybutenes, polyisobutylene, low molecular weight polyethylene, low density polyethylene and process oils of not more than 39.95 weight percent based on the weight of the final adhesive composition.

2. The melt adhesive composition of claim 1 wherein said amorphous polypropylene is obtained as a byproduct during the production of crystalline polypropylene.

3. The melt adhesive composition of claim 1 wherein said amorphous polypropylene is obtained as a direct product of the polymerization of propylene without the formation of crystalline polypropylene.

4. The melt adhesive composition of claim 1 wherein said amorphous polypropylene has a crystallinity of less than about 5 weight percent and a molecular weight in the range of about 1000 to about 25,000.

5. The melt adhesive of claim 1 wherein the total average molecular weight range of the styrene portion of said block copolymer is in the range of about 2000 to about 125,000.

6. The melt adhesive of claim 1 wherein the total average molecular weight range of the styrene portion of said block copolymer is in the range of about 5,000 to about 50,000.

7. The melt adhesive of claim 1 wherein the average molecular weight range of the ethylene/butane-1 and ethylene/propylene blocks is in the range of about 10,000 to about 500,000.

8. The melt adhesive of claim 1 wherein the average molecular weight range of the ethylene/butane-1 and ethylene/propylene blocks is in the range of about 20,000 to about 300,000.

9. The melt adhesive of claim 1 wherein the total weight of the styrene portion of said block copolymer is in the range of about 5 to about 50 weight percent.

10. The melt adhesive of claim 1 wherein the total weight of the styrene portion of said block copolymer is in the range of about 10 to about 35 weight percent.

11. The melt adhesive of claim 1 wherein the (A) components are present in the following relative amounts:
Weight Percent Amorphous Polypropylene 30 - 90 Block Copolymer 5 - 20 Hydrocarbon Tackifier 5 - 50

12. The melt adhesive of claim 1 wherein said styrene blocks are composed of styrene.

13. The melt adhesive of claim 1 wherein said styrene blocks are composed of alpha methyl styrene.

14. The melt adhesive of claim 1 wherein said styrene blocks are composed of a ring substituted styrene.

15. The melt adhesive of claim 1 wherein said styrene blocks are composed of a ring alkylated styrene.

16. The melt adhesive of claim 1 wherein said composition consists of said amorphous polypropylene, a styrene-ethylene/butane-1 block copolymer and said tackifier.

17. The melt adhesive of claim 1 wherein said composition consists of said amorphous polypropylene, a styrene-ethylene/propylene block copolymer and said tackifier.

18. The melt adhesive composition of claim 1 wherein said hydrocarbon tackifier has a ring and ball softening point in the range of about 25C to about 125C.