Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2 ~ ~ ~ 3 7 ~ :
~NO gO/14396 PCI'/US90/02948
ADHESIVE CO~OSITIONS CON~CAINING LOI~ MOLECULAR WEIGHT
POLYE~lEYI~ OXIDES
1 This ls a continuation-ln-part of copending U.S. Ser~al No.
2 35~,532, filed May 23, 1989, entitled "Adhes~ve Compos1tion
3 Conta~n~ng Low Molecular Weight Polyphenylene Oxides," now
4 abandoned.
BACKGROUND OF THE INVENTION
l. Field of the Invenff on
The invention relates to the use of low molecular weight
6 polyphenylene ox~des in adhesive blends compr~sing styren~c tr~block
7 copolymers such as polystyrene-poly~soprene-polystyrene (S-I-S) and
8 polystyrene-polybutadiene-polystyrene (S-B-S) to prov~de increases in
g the shear adhesion fa~lure temperatures (SAFT) of the corresponding
lo pressure sensit~ve, hot melt pressure sens~t~ve or hot melt
11 adhesives. ~The SAFT ~ncreases are obtained without sign1f~cant hot
12 melt formulation viscos~ty increases and w~th little ~mpact on the
13 pressure sensitive adhes~ves' tack or peel strength.
2. Description of the Pr~or Art
14 In U.S. Patent 3,660,531, there are disclosed polyblends
15 conta~ning: (A) greatler than 50X of a thermoplastk resin matr1x,
16 said resin matrlx cons~sting of polyphenylene ox~de res~n in
205637~ -
WO gO/14396 PCI/US90/02948
- 2 -
1 combination ~th alkenyl aromatic resins; and (B) less than 50~ of an
2 elastomer selected from a group consisting of poly(butadiene), and ~
3 random, block or graft copolymers of butadiene and styrene. The -;
4 resulting blends exhibit unexpected thermoplast~c properties -
s ~nclud~ng ~m?roved melt processabil~ty and ~mpact resistance without
6 sacrificing the des~rable heat d~stortion temperature and flexural
7 modulus of unmodified polyphenylene oxide resin. The materials in
8 this patent are thermoplastic resins and not adhesives, and the
g degree of polgmerization (DP) of polyphenylene oxide is greater than
10 about 100.
11 Commonly ass~gned U.S. Patents 3,835,200 and 3,994,856
12 disclose respectively, polyphenylene ether and rubber styrene
13 copolymer compos~t~ons containing rigid block copolymers of
14 con~ugated d~enes and vinyl aromatic compounds, and h~gh impact
15 rubber modified polystyrene compos~t~ons contain~ng polyphenylene
16 ether and v~nyl aromaff c block copolymers; however, the compositions
; 17 are thermoplasff cs and the DP of the polyphenylene oxides ~s greater
18 than 50.
19 Hot melt adhesive compos~t~ons are disclosed in Hansen, U.S.
20 Patent 4,104,323. The adhesive composition is prepared by first melt
21 blending a po1yphenylene ether resin and a low molecular weight
22 aromR ff c res1n, and then blending the resulting 0ixture and a
23~monoalkenyl arene/con~ugated d~ene block copolymer, tackifging resin,
24 and opt~onal hydrocarbon process~ng oll. The molecular weight of the
25 polyphenylene ox~de ~n the polyphenylene ox~de alloy ~s between 6,000
26 and 25,000. The glass transition temperature is between 170 and
27 ~205-C. Th~s melt blend avo~ds the use of solvents wh11e also
28 avo~ding ox~daff ve~de,gradaff ~nlof the block copolymer. The resulting;
29 polymer blend possesses a much higher service temperature when used
0 as an adhesive.
3l An adhes~ve compos1tion hav~ng improved high temperature
32 properties ~s also disclosed ~n U.S. Patent 4,141,876. The
compos~tion is prepared by melt blend~ng a polyphenylene ether resin,
a select~vely hydrogenated arene/conjugated diene block copolymer, a
35 tacklfy~ng restn, and optionally, a hydrocarbon processing oil. This
2 ~ 7 4
WO 90/14396 PCI/USgO/02948
1 patent ~s restricted to hydrogenated block copolymers whlch can
2 withstand the extremely high blending temperatures requlred to
3 disperse the polyphenylene oxide res~ns, (230-C to 260-C) and to
4 polyphenylene ox~de resins having a molecular weight (MV1S) between
6,000 and 25,000. The glass transition temperature of the res7n ~s
6 restricted to between 170- and 210-C.
SUMMARY OF THE INVENTION
7 A need ex1sts in the practice of adhes~ve formulat~ng to
8 obta~n adhesive compositions with h19her serv k e temperatures and
g manageable hot melt viscos~tles. The present lnvention descr~bes the
10 use of low molecular weight polyphenylene ox~de res~ns (PPO) in hot
11 melt or pressure sensitive adhesive compositions comprising:
12 (a) lOO phr of a block copolymer having at least two
13 monoalkenyl arene polymer endblocks A and at least one elastomerlc
14 con~ugated-diene midblock B, said blocks A comprising 8-55X by weight
15 of the block copolymer. Illustrative of the blocks are styrenic
16 block copolymers such as polystyrene-polybutadiene-polystyrene
17 (S-B-S), polystyrene-poly1soprene-polystyrene (S-I-S), poly
18 (a-methylstyrene)-polyisoprene-poly (a-methylstyrene), or their
19 selec ff vely hydrogenated derivatives.
~b) about SOL200 phr (part per hundred rubber) of a
; 21 tack1fy1ng resin compatible with the rubbery midblock of the block
22 copolymers and
23 (c) about 5-50 phr of a low molecular weight PPO resin wtth
24 glass transition temperature (Tg) between lOO-C and 165-C,
2S preferably between 140- and 163-C. - -
26 The tackify1ng res~n, which is compatible with the
27 elastomer k m~dblock of the triblock copolymer, ~s used to render the
28 formulation tacky. Preferred tack~fy~ng resins are those derlved
29 from the copolymerization of diolefins and espec~ally of C5
30 diolef1ns such as piperylene with C5 olefins such as
1 2-methyl-2-butene. These resins, such as ESCOREZ 1310LC, ava~lable
32 commerc1ally from Exxon Chemical, have r1ng and ball soften~ng points
33 between 80-C to 115-C. Another useful tackifying res1n, Zonatac lOS
2 ~ 7 ~
W O 9~/14396 P ~ /US90/O~g48
1 Lite, available from Ar~zona Chemicals, ~s prepared by the cat~onic
2 polymer~zat~on of limonene and styrene. Other useful tack~fy~ng
3 resins ~nclude those derived from ros~n esters, terpenes, and terpene
4 phenollc res~ns. Hydrogenated vers~ons of the above are also useful.
Hydrocarbon extend~ng o11s (0-200 phr) can be employed in
6 this appl~cation to modify the formulatlon v~scos~ty and to increase
7 the tack~ness of the adhes1ve. The extending oils, referred to as
8 paraffinic/naphthen~c oils are fractions of refined petroleum
g products hav~ng less than 30~ by we~ght aromatics and v~scos~t~es
lo rang~ng from 100 to 500 SSU at lOO-F. O~ls are commerc~ally
11 ava~lable such as Shellflex 371, a naphthenic o~l manufactured by
12 Shell.
13 The adhes~ve formulations are prepared by dissolving in a
14 solvent such as toluene, and cast~ng over a substrate such as mylar.
15 Optionally, to apply the formulat~on as a hot melt, the components
16 are melt blended in a Brabender mixer. The temperature for melt
17 blend~ng w~ll depend upon the Tg of the PPO. Th~s ~s a s~gnificant
~8 advantage of using PPO of lower Tg than that cla~med ~n U.S.
19 Patents 4,104,323 and 4,141,876.
The invention discovery ~s that polyphenylene ox~de
21 copolymers, hav~ng low molecular weight and high glass transition
22 temperatures~, extend the temperature range of pressure sens~tive and
23 hot melt adhes~ve systems wh kh contain styren~c triblock
24 copolymers. Thls is a consequence of their compat~b~l~t~es with the
25 polystyrene domains of the tr~block copolymers used in these adhesive
26 applications. Because these adhesive formulations are useful up to
27 the glass trans~t10n temperature of the polystyrene domains, blending
28 a high Tg PPO polymcr ~nto the polystyrene doma~ns ~ncreases the
29 Tg-of the glassy doma~ns and consequently ~ncreases the useful
30 temperature range of the adhesive. The glass trans~t~on temperature
31 range for the PPO res~n, 100-165-C, preferably 140-163-C enables hot
32 melt applicat~on of the adheslve formulation. Higher Tg PPO res~ns
33 cannot be hot melt processed unless they are preblended w~th lo~
34 molecular weight aromatic resins such as polystyrene as described in
35 U.S. Patent 4,104,323. Furthermore, the lower Tg PPO's of this
~ ~ S ~ 3 7 L~'
WO 90/14396 PCI/US90/02948
1 invention provld-e superior adhes~ve properties compared w~th the
2 higher Tg PPO's.
3 Accord~ng to the "Glossary of Terms Used 1n the Pressure
4 Sens~tive Tape Industry", a pressure sensitive adhes~ve ~s ~ mater~al
which ls aggressively and permanently tacky, adheres without the need
6 of more than finger pressure, exerts a strong holding force, and has
7 suffic~ent cohes~veness and elast~city that lt can be removed from
8 substrates wlthout leaving a res~due. A hot melt adhes~ve, on the
g other hand, ~s a lOOX nonvolatile thermoplastic material that ~s
10 heated to a melt and applied to the substrate as a 11qu~d~ The hot
11 melt bond forms after the l~qu~d cools and solid~fies. Some pressure
12 sens~tive adhes~ves, such as those based on block copolymers, are
13 appl~ed as hot melts, and are referred to as hot melt-pressure
14 sens~tivs adhes1ves.
Typically, commerc1al PPO's are derived from the
16 2,6-dimethyl phenol monomer. In accordance with this invention there
17 ~s described the use of h~gh Tg, PPO copolymers. One advantage of
18 the use of the copolymers ~s the lower cost of the monomers such as
19 o-cresol as compared wlth the more expens~ve 2,6-d~methyl phenol
20 monomer thereby resulting in a lower cost PPO. Further, the use of
21 comonomers y~elds the low molecular we~ght PPO res~ns whtch are best
22 su~ted for ~these applications. The useful glass trans~t~on
23 temperature range for these PPO resins ranges from 100-165-C,
24 preferably between 140-163-C. Th~s range, less than that descr~bed
25 1n U.S. Patents 4,104,323 and 4,141,876, provides superior adhesive
26 serv~ce temperature ~ncreases wh~le allow~ng hot melt processibility
27 below 200-C.
28 These low molecular we~ght polyphenylene ox~des ~mprove the
29 high temperature performance of styren~c block copolymers ~n pressure
30 sens~t~ve adhesive systems. For example, a 7 parts per one hundred
31 rubber (phr) loading of the PPO ~n a formulat~on prov~des about a
32 32-F ~mprovement in the shear adhes~on fa~lure temperature ~SAFT)
33 w~th 11ttle ~mpact on the pressure senslt~ve adhes~ve's tack.
2~637~1
WO 90/14396 PCI/US90~02948 '
DETAILED DESCRIPTION OF THE INVENTION
1 In the use of low molecular weight polyphenylene oxides to
2 increase the serv~ce temperatures of block copolymer adhes~ve
3 systems, the upper use temperature of these adhes~ves is l~m~ted to
4 the softenlng temperature (Tg) of the polystyrene domains. In
accordance with this invention, a h~gh Tg PP0 w~th good polystyrene
6 thermodynamic compatibility ~ncreases the serv~ce temperature when
7 blended ~nto the adhes~ve formulatlon.
8 Block copolymers employed ~n the ~nvention may have
g geometr~cal structures, however the ~nvent~on does not depend on a
10 part k ular structure, but rather upon the chemical const~tut~on of
11 each of the polymer blocks. Thus, the structures may be l~near,
12 rad1al, or branched so long as each copolymer has at least t~o
13 polymer endblocks and at least one polymer m~dblock. Thus the
14 invent~on contemplates (but is not l~mited to) the use of
configurations such as (A-B-A)n where n var~es from 1 to 20, and
16 preferably from l to 3, most preferably l. Methods for preparat~on
17 of such polymers are well known ~n the art. Although the term
18 tr~block is used throughout ~t is to be understood that where
19 appl~cable the rad~al and branched blocks are ~ncluded.
The invent~on applies espec~ally to the use of polymers
21 having the conf19uration of the follow~ng typ~cal species:
22 polystyrene-polybutadiene-polystyrene (S8S)
23 polystyrene-poly~soprene-polystyrene (SIS3
24 poly(alpha-methylstyrene)-polybutad~ene-poly
talpha-methylstyrene~ hMS-B-oMS)
26 poly(alpha-methylstyrene)-poly~soprene-poly
27 (alpha-methylstyrene) (#MS-I-oMS).
28 It ~s to be understood that both Blocks A and B may be
29 either homopolymer or random copolymer blocks as long as each block
30 predominates ~n at least one class of the monomers character king the
31 blocks as defined. Thus, blocks A may comprise styrene/alpha-
32 methylstyrene copolymer blocks or styrene/butadiene random copolymer
33 blocks as long as the blocks individually predominate in monoalkenyl
34 arenes. The term "monoalkenyl arene" includes styrene and its
` ~ ~3 ~3 ~ ~'7 4
wo 90/14396 PCT/US90/02g48
1 analogs and homologs including alpha-methylstyrene and
2 ring-substituted styrenes, particularly ring-methylated styrenes.
3 The preferred monoalkenyl arenes are styrene and alpha-methylstyrene,
4 and styrene ~s part~cùlarly preferred. The blocks B may compr~se
s homopolymers of bùtad~ene, ~soprene, copolymers of butadiene and
6 ~soprene and copolymers of one of these two d~enes ~th monoalkenyl
7 arene as long as the blocks B predominate in conjugated diene un~ts.
8 The rubbery midblock of these polymers may be hydrogenated, but
g non-hydrogenated midblocks can also be used since excessively high
10 blend~ng temperatures are not generally requ~red to prepare the
11 blends of the present ~nventory. When the monomer employed ~s
12 butad~ene, ~t ~s preferred that between about 35 and about 55 mole
13 percent of the condensed butad~ene un~ts ~n the butad~ene polymer
14 block, have a 1,2 conf~gurat~on.
Polyphenylene ox~des of the ~nvention will have repeat~ng
16 un~ts represented by the formula: -
. Q
~ O_ ~ ';
` l Q J n
17 wherein the oxygen ether atom of one unit ~s connected to the benzene18 nucleus of the next adjoining un~t, n ~s a pos~tive ~nteger of from
19 10 to about 40 thereby prov~d~ng a MW range of about 1000-S000, and ;
20 each Q ~s a monovalent subst~tuent selected from the group cons~st~ng
21 of hydrogen, halog$n, hydrlocarbon rad~cals, hydro!carbonoxy rad~cals,
22 and halohydrocarbonoxy rad~cals hav~ng at least two carbon atoms
23 between the halogen atom and phenyl nucleus. Espec~ally preferred
24 polyphenylene ox~de res~ns for purposes of the present ~nvent~on are
25 those hav~ng alkyl subst~tut~ons ~n the two pos~t~ons ortho to the
z6 oxygen ether atom - ~.e. where each Q is alkyl, most preferably,
27 hav~ng from 1 to 4 carbon atoms.
2~)~6;~7 .~
WO 90/143!~6 PCI~/US90/02948
1 The polyphenylene ox~des employed ln accordance with the
2 invention, prepared from 2,6-xylenol and additional comonomers such
3 as o-cresol, allow the eost of the PPO to be materially reduced.
4 Also, since it ~s necessary to control the extent of polymerization
s to obtain PPO products of low molecular weights, the use of the
6 comonomers and control of the amount of oxygen adm~tted to the
7 reaction allows preparation of the low molecular weights necessary to
8 the invention.
g In general, the low molecular weight polyphenylene ox~des
10 are prepared using a cuprous chloride-pyridine catalyst system in
11 chlorobenzene solution. Magnesium sulfate is used to remove moisture
12 from the reactions. The products are isolated by precipitation with
13 a lOX HCl/methanol solution, and are dissol~ed and reprecipitated to
14 remove any residual traces of catalyst or diphenoquinone side
15 products.
16 PPO yields and glass transition temperatures are controlled
17 by varying the degree of polymerization. This is ach~eved by
18 changing the reaction time and consequently the amount of oxygen. A
19 longer reaction time permits the formation of hlgher molecular weight
20 and high Tg products, which, when precipitated, afford higher
21 recoveries. ~-
22 Further control of the molecular weight ~s prov~ded by the
23 use of o-cresol or other comonomers, whlch give low degrees of
24 polymerization with the present catalyst system.
Polyphenylene oxides of low molecular weight, useful in the
26 invention, also can be prepared accordtng to the Perec article in J.
- 27 of Polymer Science (vol 25, p 2605) from 4 bromo-2,6-dimethylphenol
28 as monomer (see Exam~lç S). ;
.... .. - . . ..
-- EXAMPLE 1
29 Cuprous chloride (lOg) and pyridine (SOml) are stirred for
30 30 minutes in SOO ml chlorobenzene. o-Cresol (48ml) and anhydrous
31 magnesium sulfate (1.59) are added and the reaction is stirred for 28
32 hours at room temperature. The insoluble portion of the reaction is
33 filtered away and the resin is precip~tated with a lOX HCl/methanol
2 ~ 3 ~ ~`
Wo 90/14396 P ~ /USgo/o~s
1 solution. The resin is isolated by filtratlon and washed w~th
2 methanol. The yield ~s 159 (30~) of a pale orange, brlttle solid.
3 The glass trans~tion temperature of the sol~d ~s 103C and H-NMR of
4 the solid shows a l:l ratio of aliphatic to aromatic protons.
EXAMPLE 2
Cuprous chloride (lOg) and pyridine (50ml) are stlrred for
6 30 minutes at room temperature in 500 ml chlorobenzene. o-Cresol
7 ~259), ?,6-xylenol (2$g), and anhydrous magnesium sulfate (1.59) are
8 added and the reaction is st~rred for 28 hours. The ~nsoluble
g port~on of the reactlon m~xture is removed by f~ltrat~on and the
lO resin ~s ~solated by prec~pitation with lO~ HCl/methanol. The resin
11 is ~solated by filtration and redlssolved ~n toluene and prec~p~tated
12 w~th methanol to remove any residual catalyst or dimeric s~de
13 products. The y~eld is 389 (76X) of a pale orange sclid. The glass
14 transltion temperature is 105-C and H-NMR analysis shows a 5:3 ratio
15 of aliphatic to aromatic pratons.
EXAMPLE 3
16 The procedure of Example 2 ~s followed except that 26.59 of
17 2,6-xylenol ard 26.5 9 of o-cresol are used. The reaction is st~rred
18 for 48 hours. A 70X yield of a pale orange solld ls obtained. The
19 glass trans~t~on temperature of the resin is 153-C and H-NMR analys~s
20 shows a 9:5 rat~o of aliphat~c to aromat~e protons.
EXAMPLE 4
21 The procedure of Example l is followed except that 509 of
22 2,6-xylenol is usedi~nstead of the o-cresol. Also, the resin is
23 d~ssolved in toluene and precipitated w~th methanol. A 61X yleld of
24 a yellow solid is obtained. The glass transition temperature of the
25 solid is 154C and H-NMR analysis of the solid shows a 3:1 ratio of
26 aliphat k to aromatic protons.
WO 90~143g6 2 0 ~ 6 3 7 ~ PCr/US90~02948
- .10 --
EXAMPLE S
1 4-Bromo-2,6-dimethylphenol (38g) ~s d~ssolved in 316 ml 6N
2 NaOH. Ammon~um hydrogen sulfate (5.089) and 316 ml toluene are
3 added, and the mixture ~s stirred for 2 3/4 hours, ~hereupon, ~t ~s
4 quenched with d~lute HCl. The toluene phase 1s separated and dried
with magnesium sulfate, and the polymer ~s ~solated by precipitation
6 with methanol (5.59). DSC and ~PC analyses are performed with the
7 following results: Tg.163-C, Mn~2600, MwlMn.1.53.
EXAMPLE 6
8 ~he procedure of Example 3 was followed except that 75g 2,
9 6-xylenol, 50 mol pyr~dine, 900 ml chlorobenzene, and 5g magnesium
lo sulfate were used. The m1xture was stirred for 72 hours. The
11 polymer yield was 43.5g, and the glass transit~on temperature was
12 145-C. ~-
In sum~ ry, the y~elds, glass transition temperatures, and
~ 4 product compos1tions for the~PPO products~ prepared for testing in- 15 adhesi~e formulat~ons are as follows:
-,. ~
GLASS~TRANSITION YI1~ COMPOSIt~ON
TEMPERATUR~
16Example 1 ~ 103-C 30X o-Cresol
17-~Exa~pl~e 2 lO5-C 76~3:4 Xylenol:o-Cresol
18~ Example 3 153-C 70X1:1 Xylenol:o-Cresol
19 Example 4 154-C 61X Xylenol
20;~ Exampie~5 163-C 24~ Xylenol
21 Example 6 145-C i 30X1:1 Xylenol:o-Cresol
22 - PPO product compos~t~ons were~determ1ned us~ng H-NMR
23 spectroscopy. A rat~o of al~phatlc protons (1.5-2.5 ppm) to aromat k
24 protons (6-7.4 ppm) lndlcates the relat~ve amounts of cresol and
25 xylenol present 1n the reslns. An enff rely 2,6-xylenol product
26 conta~ns a 3:1 rat~o of al~phat~c to aromdt~c protons wh11e an
-27 ent~rely o-cresol product contains a 1:1 ratio of aliphatic to
28 aromat k protons.
- .
2 ~ 5 ~
WO gO/143g6 P~r/USgO/02g48
1 1
1 In the follow~ng embod~ments, examples and comparisons,
2 these materials were employed:
3 (1) Kraton 1107; a styrene-isoprene-styrene block copolymer from
4 Shell having block molecular weights of about
s 13,000-160,000-13,000.
6 t2) ESCOREZ 1310LC; a C5 olefln/diolefin tackifying resin from
7 Exxon Chemicals having a ring and ball soften~ng point of
8 95-C.
9 (3) Stereon 840A; a tapered styrene-butad~ene-styrene block
lo copolymer from Firestone hav~ng Mn of 60,000 and 43 wt X
1l styrene.
12 (4) Zonatac 105L; a limonene/styrene tackifying resin from
13 Ar~zona Chemicals having a ring and ball softening point of
14 105-C.
(5) Shellflex 371; a naphthenic extending oil from Shell.
16 (6) Irganox 1010; an ant~oxidant from CIBA-Geigy.
17 (7) Noryl; a PPO ~rom General Electr k having a Tg of 194'C.
ADHESIVE TESTING WITH SIS FORMULATIONS
18 S-I-S formulations with E-1310LC as tacklfier resin were
19 prepared for testing as pressure sensit~ve adhesives. All PPO
products were used at two different levels and the 90- quick stick,
21 180- peel, polyken tack, and shear adhesion failure temperatures were
22 measured for each of the formulations. The formulations were cast
23 from toluene onto mylar, and dried ~n an oven at 80C to give a .0015
24 i n . coating.
~he adhesive tests are those commonly employed by the
26 pressure sens~tive adhesive~ndustry. In the shear adhesion failure
27 temperature test, a l"xl" overlap of tape to a sta~nless steel
28 substrate is made with a 4.5 pound roller. A 1 kg weight is hung
29 from the tape and the assembly is placed in an oven. The temperature
is ~ncreased at 40F/hour and the temperature at which the we~ght
31 drops ~s recorded as the SAFT. In the polyken tack test, a steel
32 probe contacts the adhesive tape with a specified force for a 1
W o 9o/14396 PCT/US90tO2g48
- 12 -
1 second dwell t;me. The force required to break the bond between the
2 adhes~ve and the stainless steel probe ~s measured (9). The 180-
3 peel test ~nvolves placlng a length of tape on a stainless steel
4 plate and laminating it w~th a l-pound roller. ~he force (lb/ln)
required to peel the tape at a 180- angle on an Instron is recorded.
6 The results of the adhes~ve testing are summarized in Table
7 l.
TA~
8 1-~ Control ~ 2 3 4 S-~ S 6 7 8 9
Control
g X~ATON 1107 100 100 100 100 100 100 100 100 100100 100
~-1310LC 150 150 150 150 lS0 150 1S0 ~50 IS0150 150
11 PPO ~x. 1 - 7.31~.7
12 PPO Ex. 2 - - _ 7 1
13 PPO ~x. 3 - - - - _ _ 7 1~
14 PPO ~x . ~ -- -- _ _ _ 7 1 ~ -
PPO ~x. S -- -- -- -- -- -- -- -- -- -- ~
16 ~rganox 1010 . 2 2 2 2 2 2 2 2 2 2 2
17 9o- Oulck
18 Stlek
19 (Ibs/~n) 2.3 2.3 2.9 2.6 2.6 l.S 2.7 1.9 l.S 1.1 - 180- Peel to-
21 SS ~lb~/ln) 6.4 6.2 6.0 S.9 S.6 4.9 S.l 5.6 ~.9 S.3 6.25
22 Polylcen Sack ; ~ ..
.23 ~g) 1000 702 605 737 350 720 603 ~9S 699518 1~80
24 SAF~
~-F) 200 217 220 229 244 204 234 240 237244 232
2 ~ 7 ~
WO 90/14396 PCI`/US90/02948
- 13 -
1 It is apparent from Table 1 that the examples representative
2 of the invention have superior SAFT than those of the comparative
3 examples. ~his indicates that lower Tg PPO resins are also useful
4 in increas~ng the service temperatures of adhesives. Finally, the
tack and peel properties of these adhesives are not adversely
6 affected by the PPO resins as indicated by maintenance of the peel
7 and qu k k stlck values with modest declines ~n polyken tack.
8 F~gure 1 illustrates the adhesive performance findings for
9 use of the PPO product of Example 3 with SIS formulations.
ADHESIVE TESTING WITH S8S FORMULATIONS
Stereon 840 (SBS) formulations with a Zonatac 105 L~te/
11 Shellflex 371 tackifying system were prepared for testing as hot melt
12 adhesives. All four PPO products were used at different levels and
-~ 13 the results of the 180- peel and shear adhesion failure temperatures
14 are compiled in ~able 2.
Figure 2 ~llustrates the superior adhesive performance
16 findihgs for the use of the PPO product of this invention with SBS
17 formulations.
.:
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Wo 90/14396 P~/US90/0294~ '
- 14 -
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WO 9O/14396 ~ ~ 5 ~ PCr/US90/02948
- 15 -
~A~LE 3: FoRMuLA~rIoN VISCOS~Sy PROFILE
1 2 3 4
1 ~raton 1107 4g ~9 _ _
2 Stereon 8~0A - ~ 3~6g 3.6g
3 Escorez 1310LC 6g 6g - -
4 20natac lOSLite - - S.~g 4.3g
PPO Ex.3 - ~.6g - -
6 PPO Ex . 4 - - - 1. Og
7 Shellflex 371 - - 1. 0g 1. 09
8 Ylscos~ty ~P~) .
9 lB0'C 76~ 710 1~6 392
200-C 280 302 ~8 1 73
ll 220-C 120 9~ 57 96
12 The v~scos~ty results indicate that the PPO products of the
13 invention can be formulated into adhesive formulations for hot
14 melts without significantly altering the viscosity profile.
Stereon 840 SSBS) formulat~ons with a Zonatac 105
16 LitelShellflex 371 tackify~ng system were prepared for test~ng as
17 hot melt adhesives and solvnet cast pressure sensitlve adhes~ves.
18 For the purpose of comparison of the PPO's of th~s ~nvention with
19 the PPO's of the prior art, the formulations were prepared with the
20 PPO of Example 6 (Tg.145-C) and NORYL (Tg.194^C). For the hot melt
21 adhesive, viscosity, T-Peel, SAFT and PAFT were evaluated. For the
22 solvent cast pressure sensitive adhesive, 180 peel and SAFT were
23 ~valuated.
24 The T-Peel test was performed according to the procedure
25 of ASTM D01876-7~, for both aluminum and polyethylene. The shear
26 adhesion failure temperature (SAFT) was determined as described
WO gO/14396 2 ~ ~ 6 3 7 ~ PCI-/US90/02948
- 16 -
l above, except that a 500 9 weight was used for a l" x l" overlap of
2 Kraft paper bonded to Kraft paper. The peel adhesion failure
3 temperature (PAF~) utilized the same geometry as the ASTM D-1876-72
4 T-Peel test except with a l" x l" overlap of Kraft paper bonded to
Kraft paper. The PAFT evaluation was conducted in an oven w~th a
6 200 9 we~ght attached. The reported temperature was the
7 temperature at which the bond failed when the oven was ramped at
8 40-Flhour. The 180- peel test was as described above. The results
9 of the,adhesive testing are summarized in Table 4.
Wh'ile the invention has focused on the use of certain
11 part k ular low molecular weight PP0 polymers having a ~9 of about
12 lOO-C to about 165-C to improve the upper temperature performances
13 of styrene block copolymer adhesive systems, it is to be understood
14 that a wide range of these polymers are suitable and that the
compositions can be dictated by economic considerations. For
16 example.; the data show that~cresol copolymers exhibi~ted
17 performances comparable to the more expens~ve xylenol homopolymer.
18 There~ore, many monomer combinations based on cresylic acids and
l9 phenol~ _ thylation products can be used without departing from the
20 ;spir1t and~scope of the use of low molecular weight PP0 polymers
21 for high temperature applicat~ons ~n pressure sensitive and hot
22 mélt adhes~ve systems.
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NO 90/14396 PCr/US90/02948
TABLE 4: PPO T~ COMPARISON
Solvent Cast PSA
Hot Melt ~hesive ( from toluene~
STEREON 840A 100 100 100 100
2 Zonatac 105 Lite120 120 120 120
3 Shellflex 371 38 . 6 38 . 6 38 . 6 38 . 6
4 PPO Ex. 6
(Tg=145-c) 38. 6 -- 38 . 6 --
6 NORYL PPO
7 (Tg=194 C) __ 38. 6 -- 38 . 6
8Brookf ield Viscosity
9180 C 24, 450 cps --*
lQ200-C 11,500 cps --*
11 T-Peel (lb/in. )
12 Al/Al 7.1 --*
13 PE/PE 0.1 --~
14 SAFT ( F)
1" x ~" x 5~0g
16 Rraft/Xraft 2 00 -_*
17 PAFT (-F)
18 1" x ~" x lOOg
19 Kraft/Kraft ~ 212 --*
20 180 Peel (lb/in. )
21 SS 2.5 0.2
22 SAFT ( F)
231" x 1" x lOOOg 213 97
24 *NORYL PPO immiscible up to 220-C
2~3i7~ ~
WO gO/143g6 PCr/US90/029~8 '
1 The most remarkable feature of the data presented in Table 4
2 is that the NORYL (tg.194-C) could not be hot melt blended at
3 temperatures up to 220-C, in contrast to the low Tg (145-C) PPO of
4 example 6. Furthermore, the adhesive properties of the lower Tg PPO
of Example 6 formulations are superior to properties achieved wlth
6 the higher Tg NORYL resin formulations. These data demonstrate a
7 clear advantage in processability and in adhesive performance for the
8 low Tg PPO compositions of this invention versus the higher Tg PPO
g resins taught in the prior art.
