Hydrocarbon resins, processes for their manufacture and adhesive compositions containing such resins

The invention relates to a hydrogenated hydrocarbon resin of a softening point from 75.degree. to 110.degree. C. having an Mw/Mn of less than 2 as determined by GPC, an aromaticity level of from 15 to 25%, and a melt viscosity in mPa.s at a shear rate of 50 sec.sup.-1 of less than 500 mPa.s, preferably less than 300 mPa.s at 160 .degree. C.

FIELD OF INVENTION 
The invention relates to hydrocarbon resins, processes for their 
manufacture and to adhesive compositions containing such resins. 
In particular, the invention relates to low-colour hydrocarbon resins with 
good compatibility with styrenic block copolymers, such as SIS and SBS, 
and to resin/block copolymer blends having good properties as an adhesive 
composition. These compositions may be used in adhesive label or sanitary 
(diaper) applications. 
BACKGROUND OF INVENTION 
Mixed olefinic/aromatic tackifier resins have been prepared from a wide 
variety of feedstocks including 
(a) Cut piperylene (piperylene concentrate) of which 1,3-pentadiene is a 
main component and C.sub.5 olefins are a minor component. 
(b) Steam cracker olefins: mainly composed of Pentene-2,2-methyl-butenes 
1,2 and cyclopentene. Steam cracker olefins is predominantly 
mono-olefinic. 
(c) Heart cut distillate containing vinyltoluenes and indene as main 
components but also containing styrenics such as styrene and 
alpha-methylstyrene. Some styrenics have a lowering effect on softening 
point. 
(d) Other aromatics (especially Indenics) tend to increase softening point. 
(e) Cyclopentadiene and dicyclopentadiene which have a broadening effect on 
molecular weight distribution and tend to increase the softening point. 
Specific disclosures include: 
Tack/fiefs for SBS with relatively low molecular weights prepared by using 
a Friedel-Crafts catalyst and polymensing a mixture of C.sub.5/ C.sub.6 
(di)olefins and C.sub.8 /C.sub.10 aromatics are disclosed in U.S. Pat. No. 
4,078,132 (Lepert) and EP-A-23456 (Evans). The softening points are low in 
EP-A-23456 (Evans). 
In Lepert Example 12 molecular weights and aromaticity are high. However 
the material does not tackify SBS satisfactorily. Ball tack is 4 to 30 cm 
and so is too high. 
In Evans such high amounts of chain transfer agent (mono-olefins) are used 
that the softening point is very low. The product will not provide a good 
adhesive/cohesive performance in SBS blends. The liquid resin serves to 
substitute the oil in hot melt adhesive (HMA) but cohesive performance is 
reduced. U.S. Pat. No. 3,784,530 (Goodyear) describes a hydrocarbon resin 
tackifier having a softening point of from 60.degree. to 110.degree. C. 
prepared by polymerizing piperylene, 2-methyl-2-butene, dicyclopentadiene 
and alpha-methyl styrene. The polymerization uses Friedel-Crafts catalyst 
systems. At least 15% of 2-methyl-2-butene is used in the feed stream 
which also contains appreciable amounts of piperylene and 
dicyclopentadiene components and an aromatic component in the form of the 
alpha-methyl styrene. 
The resulting resin is not hydrogenated. It is said to be suitable for 
track/lying natural and synthetic rubbers including butadiene-styrene 
copolymers. There is no specific disclosure of block-copolymers. The 
amounts of 2-methyl-2-butene used are high (above 15 wt %) and this adds 
to the cost of the resin. At least 15 wt % must also be used of a costly 
alpha-methylstyrene component to provide the desired aromaticity. The 
amounts of aromatic component added are minor but the feed components have 
to be fairly pure (hence the use of alpha-methylstyrene) if a low Gardner 
colour, rubber-compatible tackifier resin is to be obtained. 
U.S. Pat. No. 3,846,352 is a divisional application from U.S. Pat. No. 
3,784,530 with almost identical disclosure. U.S. Pat. No. 4,037,016 
discloses a resin prepared by Friedel-Crafts polymerisation which is used 
in an adhesive composition including block copolymers,-with end-blocks 
forming from 10 to 50 wt % of the copolymer. The tackifying resin has 
carbon to carbon unsaturation and therefore must be essentially 
non-hydrogenated. The softening point is low from 60.degree. C. to 
80.degree. C. 
The feed stream appears to have a similar composition to that described 
previously but uses higher levels of costly alpha-methyl styrene (over 40 
wt %). Other branched chain mono-olefins are described other than 
2-methyl-2-butene although 2-methyl-2-butene still seems preferred. 
U.S. Pat. No. 4,046,838 describes a block copolymer blend with a resin. The 
block copolymer may be an SBS. The resin has a softening point of a range 
of 60 to 110.degree. C. The composition of the resin feed stream appears 
identical to that of earlier Goodyear documents referred to. The adhesive 
compositions may be used as a pressure sensitive adhesive. 
U.S. Pat. No. 4,104,327 discloses an adhesive composition comprising a 
block copolymer (including SBS) and a hydrocarbon resin. The hydrocarbon 
resin contains from 40 to 95% by weight of a C.sub.5 1,3-pentadiene 
(piperylene) component and from 60 to 5% by weight of an 
alpha-methyl-styrene unit in the polymer chain. 
In the examples 1,3-pentadiene is used exclusively as a diolefin component 
with much smaller amounts of alpha-methyl-styrene. Table 1 summarizes the 
examples. No comparison is made with a resin containing C.sub.5 diolefin 
and C.sub.5 olefin including branched chain mono-olefins and major amounts 
of an aromatic component. 
Relatively costly pure feedstocks are used. The molecular weight 
distribution is not given. 
EP 175,593 (Exxon) uses a hydrocarbon resin derived from a C.sub.5 C.sub.6 
olefin and diolefin feed as well as from 5 to 30 wt % of para-methyl 
styrene. The use of para-methyl styrene as opposed to alpha-methyl styrene 
prevents the decreasing of the softening point. By far the larger amount 
is olefin and diolefin. The olefinic feed stock is a mixed stream obtained 
by the cracking and distillation with from 50 to 14.5 wt % of diolefin, 
from 33.5 to 13 wt % of olefin and from 20 to 35 wt % of aromatics. The 
stream contains from 4.5 to 15.5% of 1,3-pentadiene. It is suggested that 
cyclopentadiene levels have to De kept low. It is suggested on page 7 that 
optionally transfer agents may be used such as branched chain aliphatic 
olefins as disclosed in GB 1538 057 to narrow the molecular weight 
distribution. A wide variety of end-uses is suggested. In the examples, no 
specific transfer agent appears to be used. Aromatic levels in the 
resulting resin are not described. 
U.S. Pat. No. 4,952,639 (Maruzen) discloses a resin and hydrogenation step. 
Adhesive compositions with ethylene-vinylacetate copolymers are prepared. 
The precursor resin is prepared using C.sub.5 diolefins (D), C.sub.5 
monoolefins (O) and aromatic monoolefins where the D/O ratio is from 1/1 
to 4/1. The resin is hydrogenated extensively. This leads to saturation of 
at least 80% of the unsaturated bonds of the olefin components and also at 
least 80% of the aromatic component which is present in an amount of at 
least 10 wt %. Branched chain olefins are not specifically added although 
they may be part of an olefinic or a diolefinic feed stream and may indeed 
be present in a high concentration (13-23 wt %) See Table 8. Both pure 
styrenic streams and mixed streams are proposed as aromatic components. 
WO 9107472 (Exxon) (PCT/GB/001749) discloses an adhesive formulation for 
blending with SBS to make an adhesive formulation including from 40 to 90 
wt % of C.sub.5 olefins and diolefins and from 10 to 50 wt % of a C.sub.8 
-C.sub.10 aromatic component to give an aromaticity of from 13 to 45 wt % 
and an Mw/Mn of less than 1.7. 
It is therefore an object of the invention to provide a hydrocarbon resin 
which can be hydrogenated to provide a low-colour styrenic block copolymer 
compatible resin and a process for making such resin from mixed, low cost 
feed streams. 
It is a further object of this invention to provide an adhesive composition 
containing a block copolymer, particularly one having high levels of 
styrene block elements, which provides good adhesion characteristics and 
which in particular is homogeneous and has a low zippiness, that is to say 
can be pulled away from a substrate under a constant force without 
jerking. 
SUMMARY OF THE INVENTION 
Firstly the invention provides a hydrogenated hydrocarbon resin of a 
softening point from 75.degree. to 110.degree. C. having an Mw/Mn of less 
than 2 as determined by GPC, an aromaticity level of from 15 to 25%, and a 
melt viscosity in mPa.s at a shear rate of 50 sec.sup.-1 of less than 500 
mPa.s, preferably less than 300 mPa.s at 160.degree. C. Preferably the 
resin has a Mw as determined by GPC of from 500 to 5000, preferably 800 to 
3000 and/or a Gardner Color of less than 10, especially less than 8. 
Such low viscosities help to improve the rheological behaviour in block 
copolymer blending to a surprising extent. The provision of a molecular 
structure yielding such low viscosity is facilitated by the process of the 
invention to provide the molecular weight, branchiness and chain 
flexibility desirable. 
Secondly the invention provides a process of preparing a low-colour 
hydrocarbon resin of a softening point of from 75.degree. to 110.degree. 
C. and an Mw/Mn as determined by GPC of less than 2 which includes the 
steps of: 
(1) preparing a resin from a feed containing a piperylene stream and an 
olefinic stream to provide a diolefin/olefin ratio (D/O) of from 1/10 to 
1/1 and a heart cut distillate stream containing C.sub.8 to C.sub.10 
aromatics to provide at least 5 wt % of indenic feed material using 
Friedel-Crafts catalyst to provide a resin having an aromaticity in the 
resin of at least 25%, preferably at least 30% in equivalent wt % styrene; 
and 
(2) hydrogenating the resin to an extent whereby less than 80% of the 
aromatic structures are hydrogenated so as to provide an aromaticity of 
from 15 to 25%. 
The resin preferably has a low molecular weight (number or weight average) 
and narrow molecular weight distribution by using an appropriate balance 
between C.sub.5 olefins and C.sub.8 -C.sub.10 aromatics without the need 
for adding purified branched chain olefins. 
The aromaticity refers to the weight percentage of theoretical styrene 
content as determined by measuring the number of aromatic protons using 
proten NMR in the polymerised resin, as explained later herein. This value 
should not be confused with the % aromatics which is the combined wt % of 
aromatic components in the feedstreams. 
Preferably the feed contains from 5 to 30 wt % preferably from 8 to 20 wt % 
of the piperylene stream; from 30 to 60 wt % of the olefin stream and from 
65 to 10 wt % of the heart cut distillate stream; and optionally no more 
than 15 wt %, preferably 10 wt % of a separate branched chain olefin 
stream, said wt % being calculated on the total weight of feedstream 
excluding an inert solvent. Suitably the hydrogenation is at 180.degree. 
to 200.degree. C. in continuous or batch form. By appropriate control of 
the polymerisation process, a melt viscosity can be obtained at a shear 
rate of 50 sec.sup.-1 of less than 500 mPa.s, preferably less than 300 in 
mPa.s at 160.degree. C. 
The feedstreams used are readily available and are of low cost. Use of 
expensive purified aromatic or branched chain olefin chains can be largely 
or completely avoided. 
It is surprising that a combination of such simple, impure feedstreams and 
selective hydrogenation should yield a high performance tackifier resin 
for styrenic block copolymers. 
The invention thirdly provides an adhesive composition of from 65 to 35 wt 
% of the above described resin and from 12 to 35 wt % of an SBS or SIS 
block copolymer, with a balance of oil, if required, and other 
conventional additives. 
The adhesive compositions may include high styrene block copolymers (from 
20 to 60 wt %, especially from 25 to 50 wt % of styrene derived units) 
which have been difficult to tackify previously. It also believed to be 
beneficial to use block polymer containing no more than 5 wt % of a 
diblock copolymer. 
DETAILED DESCRIPTION OF INVENTION 
This pan of the description will follow the raw material flow which leads 
to the making of the adhesive compositions. 
With reference to the unhydrogenated hydrocarbon resin, the feedstreams 
used in its manufacture are generally obtained from cracked petroleum 
feedstock and a subsequent refining processes. However feedstreams may 
also be obtained from other refining routes whilst having the same 
essential characteristics. 
In the case of a feedstreams obtained by cracking, an early distillation 
step may yield a lighter fraction and a heavy fraction, the latter one of 
which in turn can be fractionated to give a heart cut distillate stream. 
The components of the heart cut distillate stream boil in the region of 
from 140.degree. C. to 220.degree. C., preferably between 160.degree. C. 
and 205.degree. C. 
Heart cut distillate (HCD) contains essentially at least 20 wt % of 
components contributing to aromaticity and preferably at least 15 wt % of 
vinyl toluenes anti at least 15 wt % of indenics (indene and methyl 
indenes). Advantageously it contains at least 50 wt % of polymerisable 
monomers. Suitably HCD contains less than 5 wt %, preferably less than 1 
wt % of dicyclopentadiene or other diolefins. The other components may 
vary and can include non-aromatic polymerisables and/or 
non-polymerisables. 
The above mentioned lighter fraction can be fractionated into a lighter 
olefin and diolefin stream and a heavier fraction which can be selectively 
hydrogenated to produce an olefin rich stream. 
The lighter olefin and diolefin stream contains generally unsaturated 
hydrocarbons usually boiling in the range of 20.degree. C. to 240.degree. 
C., preferably 20.degree. C. to 130.degree. C. It is generally subjected 
to fractionation to remove C2 to C4 light ends. If the feedstock contains 
large amounts of cyclopentadiene it should preferably be subjected to 
thermal soaking at a temperature between 100.degree. C. and 160.degree. 
C., preferably 110.degree. C. to 140.degree. C. The thermal soaking 
preferably takes 0.5 hour to 6 hours, e.g. 0.5 to 3 hours to reduce the 
level of cyclopentadiene or dicyclopentadiene to below 2 wt %. Low 
temperature heat soaking is preferred in order to limit the cyclic diene 
(cyclopentadiene and methylcyclopentadiene) co-dimerisation with C.sub.5 
linear conjugated dienes (isoprene and pentadienes 1,3 cis- and trans-). 
After fractionation and, if carried out, thermal soaking, the feedstock is 
preferably subjected to distillation to remove cyclic conjugated diolefins 
which are gel precursors (cyclopentadiene and methylcyclopentadiene being 
removed as dimers). The piperylene stream or piperylene concentrate stream 
results which essentially contains at least 40 wt % of piperylene, with 
preferably a negligible aromatic content. The stream may contain however 
limited amounts of a branched chain olefin(s) which have a transfer 
activity. Suitably the piperylene concentrate stream contains at least 90 
wt % of copolymerisable monomers with at least 50 wt % of piperylene 
(1,3-pentadiene) not more than 40 wt % of other C.sub.5 olefins, less than 
2% of isoprene and less than 1% of cyclopentadiene--(this term also 
includes dicyclopentadiene and methyl substituted analogues of 
cyclopentadiene and pentadiene). 
As to the heavier fraction, a selective hydrogenation of the C.sub.5 
/C.sub.6 olefinic/diolefinic material yields a mono-olefinic stream 
referred as the olefin or C.sub.5 olefin stream. The olefin stream 
contains essentially 50-90 wt % of polymensable monomers: and a minimum of 
10 wt %, preferably 15, and especially 19 wt % of a branched chain 
olefin(s) (such as 2-Me-butene 1,2) which have a transfer activity. 
This stream contains preferably less than 2 wt % of diolefins. It does 
contain limited amounts of branched olefins which have a chain transfer 
activity. 
Isoprene should preferably be less than 2 wt %, preferably less than 1 wt % 
in the overall feed resulting from the combination of the individual 
streams. 
Whilst essential characteristics of the different streams have been set out 
above as well as preferred levels of monomer contents in such streams, the 
combined effect of these streams in minimising or eliminating the use of 
purified transfer agent depends on an adequate combined presence of 
branched chain olefins and aromatics. Typically the combined minimum of 
aromaticity contributing monomers in the HCD and the C.sub.5 olefins 
should be 140 wt % or some other value to achieve the desired narrow 
molecular weight distribution. 
The following Table summarises the information. 
TABLE 
__________________________________________________________________________ 
Aromaticity 
Total 
Monomers 
C.sub.5 diolefin 
C.sub.5 olefin 
contributing 
polymerisable 
__________________________________________________________________________ 
Stream 
&gt;50% &lt;40% "0% &gt;90% 
Piperylene 
&lt;2% isoprene 
concentrate 
&lt;1% cpd/dcpd 
C.sub.5 olefin 
"0% &gt;58% of which 
"0% A 
&gt;18% branched 
chain olefin 
HCD &lt;1% cpd/dcpd 
"1% &gt;58% B 
TOTAL &gt;50% &gt;98% &gt;58% 
in feed 
piperylene 
__________________________________________________________________________ 
A + B &gt; 120%, preferably at least 140 wt % 
All % are wt % 
cpd = cyclopentadiene 
dcpd = dicyclopentadiene 
The A value represents a lower threshold of concentration of the 
polymerisable components in the C.sub.5 olefin and HCD stream. 
The exact composition depends on the nature of the petroleum feedstock 
which is subjected to steam cracking. These feeds may contain materials 
such as paraffins and aromatics which are not polymerised during the 
process of the invention. More particular, preferred ranges of components 
in the streams are set out in the Examples. 
The feed of the combined streams is then polymerised using any suitable 
Friedel-Crafts catalyst system. Generally these may be based on 
AlCl.sub.3. It may be used in an amount of from 0.25 to 3.0 wt %, 
preferably 0.5 to 1.5 wt % based on the weight of the mixture to be 
polymerised. The optimum concentration depends on the nature of the 
solvent which affects to solubility of the catalyst as well as on the 
stirring efficiency inside the polymerisation reactor. 
Other Friedel Crafts catalysts like titanium tri- or tetrachloride, tin 
tetrachloride, boron trifluoride, boron trifluoride complexes with organic 
ethers, phenols or acids can also be used but they lead to rather low 
resin yields and large quantities of liquid oligomers of low value are 
obtained. Even though these oily oligomers can be upgraded to reactive 
plasticizer or liquid plasticizer, such catalysts are not recommended. 
Other possible catalysts can be acidic clays. 
Usual polymerisation temperatures are between -20.degree. C. and 
100.degree. C., preferably between 30.degree. C. and 80.degree. C. If 
lower temperatures are used, the resin colour is improved although there 
can be a reduction in yield. 
After polymerisation, the residual catalyst may be removed by, for example, 
washing with aqueous solution of alkali, ammonia or sodium carbonate, or 
by the addition of an alcohol such as methanol and subsequent filtration. 
The final resin may be stripped of unreacted hydrocarbons ("raffinate" rich 
in benzene and/or paraffins/unreactive olefins) and low molecular weight 
oligomers by stream stripping or vacuum distillation. The finished resin 
usually has a higher softening point. 
With reference to the hydrogenation, the raw resin prepared as described 
above contain both aromatic and aliphatic unsaturation. The resin is 
hydrogenated according to the invention to remove color whilst 
deliberately reducing the aromatic unsaturation. The hydrogenation may be 
batch or continuous. Typical examples of catalysts include nickel, 
palladium, platinum and molybdenum sulphide Ni--W, Ni--Mo, Co-Mo catalyst 
with a preferred catalyst being a preactivated catalyst on a support such 
as alumina, kieselguhr, activated charcoal, silica, silica alumina and 
titania. 
The hydrogenation step may take place in a solution of the resin in a 
suitable hydrocarbon solvent. The solution is passed with an excess of 
hydrogen or hydrogen rich gas over a catalyst. The hydrogenation may also 
take place in a batch reactor using intensive agitation of a solution and 
slurried catalyst particles. 
After hydrotreating, the mixture from the reactor may be flashed and 
further separated to recover the solvent and hydrogen for recycle and to 
recover the hydrogenated resin. The solution is flashed and/or distilled 
in an oxygen-free or minimum oxygen atmosphere to eliminate the solvent, 
and thereafter, may be steam distilled to eliminate the possible light 
oily polymers of low molecular weight, known in the trade by name of 
"fill", preferably taking care not to raise the temperature of the resin 
above 325.degree. C. to avoid degrading the colour and other properties of 
the finished resin. 
The polymeric resin can be flaked. 
Hydrogenated low colour resins are thus obtained from low cost streams 
avoiding undue amounts of costly purified streams. The resins have a 
narrow molecular weight distribution, optimum aromaticity and desirable 
molecular weight and viscosity characteristics for tackification of 
styrenic block copolymers. 
To prepare the adhesive composition the block polymer and tackifier are 
blended in suitable mixing equipment together with additives. The 
characteristics of the resin permit very homogeneous mixing and good 
compatibility particularly with higher aromatic content block copolymers. 
The blockcopolymers may include hydrogenated SIS and SBS blockcopolymers as 
well as unhydrogenated. The copolymer may be linear, radial, tapered, 
multiblock and multi-arm types. 
Diblock copolymer may be present either added separately or as by-products 
from original tri-block manufacture. The weight molecular weight Mw may 
vary from 50,000 to 200,000.

The invention will now be described by reference to the following examples. 
EXAMPLES 
A reactor feed was mixed from feedstreams and a paraffinic solvent in the 
proportions set out in Table 2. The mixture was then polymerised at 
50.degree. C. using 0.75 wt % AlCl.sub.3 as catalyst. The conditions used 
were as follows: 
The reaction mixture (as described in Table 2) was fed to a 2 liters glass 
reactor which was fitted with a mechanical stirrer a cooler and a catalyst 
injection device. 0.75 wt % of powdered AlCl.sub.3 as catalyst based on 
the total weight of the feed was injected into the reactor which was then 
held at 50.degree. C. for 90 minutes. An ammonia solution was added to 
stop the reaction after the desired reaction time. The resin was then 
obtained after steam-stripping at 250.degree. C. under nitrogen 
atmosphere. The total yield was 40 wt % (it can range from 30 to 45 wt %). 
12 wt % of fill was removed in steam-stripping. 
The piperylene cut stream, the C.sub.5 olefin steamcracker stream and the 
heart cut distillate stream were obtained as explained previously and have 
the compositions set out in Table 1. 
The three streams were combined into a single feed streams in the 
proportions set out in Table 2: 
TABLE 1 
______________________________________ 
Piperylene Steamcracker 
Monomers (wt %) 
Concentrate 
C.sub.4 -C.sub.6 Olefins 
HCD 
______________________________________ 
C.sub.4 Olefins 2-7 
Pentene-1,2 6-9 20-35 
2-Me-Butene-1/2 
6-9 19-25 
Cyclopentene 14-16 6-18 
C6 Olefins 1-9 
Piperylene 57-62 &lt;1 
Isoprene &lt;2 &lt;1 
CPD/DCPD &lt;2 &lt;3 &lt;1 
Styrene 1-2 
%-Me-Styrene 5 
c,t-.beta.-Me-Styrene 6 
Vinyl-Toluenes 21-27 
Indene 22-28 
Me-indenes 0.5-2 
TOTAL Olefins 28-34 58-82 -- 
TOTAL Diolefins 
60-64 &lt;4 &lt;1 
TOTAL Aromatics 
-- -- 58-67 
TOTAL Branched chain 
-- -- -- 
olefins 6-9 19-25 -- 
______________________________________ 
Me = methyl 
SC = steam cracker 
CPD = cyclopentadiene 
DCPD = dicyclopentadiene 
c,t = cis, trans 
HCD = heart cut distillate 
The table gives ranges reflecting common feedstream variations. 
TABLE 2 
__________________________________________________________________________ 
Name Type Characteristics 
WT % 
__________________________________________________________________________ 
Cut Piperylene 
C.sub.5 Diolefin (D) 
D + O = 90-95 wt % 
15 
C.sub.5 Olefins (O) 
D/O = 1.8-2.2 
C.sub.5 Olefins 
C.sub.4 -C.sub.6 Olefins 
58-82 wt % content of olefins 
40 
(ex SC) (36-50) 
HCD C.sub.8 -C.sub.10 Aromatics 
58-67 wt % of total C.sub.8 -C.sub.10 
35 
Indenics/Styrenics* = 0.7-0.9 
(32-39) 
LVN (Light Virgin 
C.sub.5 -C.sub.7 Paraffins 
balance 
Naphtha) (0-18) 
(0-18) 
__________________________________________________________________________ 
##STR1## 
The LVN is a polymerization diluent. The bracketed matter shows ranges 
available. 
The resulting combined feed stream for the Example had the composition set 
out in Table 3: 
TABLE 3 
______________________________________ 
Monomers (wt %) 
______________________________________ 
C.sub.4 Olefins 1 
Pentene-1,2 11.3 
2-Me-Butene- 1/2 10.6 
Cyclopentene 7.5 
C.sub.6 Olefins 3.5 
Piperylene 9.5 
Isoprene 0.2 
CPD/DCPD 0.3 
Styrenics: 4.6 
Styrene 0.5 
%-Me-Styrene 1.9 
C,t-.beta.-Me-Styrene 
2.2 
Vinyl-Toluenes 8.2 
Indenics: 10.2 
Indene 9.6 
Me-Indenes 0.6 
TOTAL Olefins 34.3 
TOTAL Diolefins 10 
TOTAL Aromatics 22.5 
TOTAL Branched olefins 
10.6 
D + O 44 
D/O 0.29 
% Aromatics 22.5 
TOTAL POLYMERIZABLE 66.8 
______________________________________ 
The resulting unhydrogenated raw resin had the following characteristics in 
Table 4: 
TABLE 4 
______________________________________ 
NEAT UNHYDROGENATED PROPERTIES 
______________________________________ 
Softening point (.degree.C.) 
85 
Initial colour (Gardner, HL) 
7 
Colour stability (Gardner) 5 hrs/175.degree. C. 
15 
Aromaticity (wt % styrene) 
33 
Mn 676 
Mw 1160 
Mz 1770 
Mw/Mn 1.7 
______________________________________ 
The resin was hydrogenated as follows: 
The resins prepared as described above contain both aromatic and aliphatic 
unsaturation and may be hydrogenated by any suitable technique which 
removes the aliphatic unsaturation and leads to the required degree of 
hydrogenation of the aromaticity in the resin. 
Before carrying out hydrogenation through a batch process the resin is 
preferably dissolved in a saturated hydrocarbon solvent typical batch 
hydrogenation takes place at a temperature of 100.degree. C. to 
200.degree. C. at a pressure of 10 to 100 bar for a period of 1 to 4 
hours. Typical catalysts are nickel palladium, platinum deposited on an 
inert support line alumina or silica. 
Suitable proportions of catalysts are from 0.5 to 10% in relation to the 
resin. 
By adjusting the above parameters, the batch time which is related to the 
hydrogen consumption and the final color of the resin can be reduced to 
the desired level, whilst at the same time the desired aromaticity content 
in the resin can be reached. 
After filtering off the catalyst, the solvent is removed by distillation 
and recovered for recycling. 
H2 consumption=150 NI/kg (the hydrogen consumption expressed in liters; 
this corresponds to a number to moles by kg of resin) 
T (temperature)=190.degree. C. 
P (pressure)=65 bar 
D (duration )=110 rain duration of batch treatment 
Catalyst concentration=2.5 wt % 
Solution concentration=30 wt % 
The hydrogenated resin 
The resulting polymerized hydrogenated resin according to the invention had 
a composition as set out in Table 5 as calculated from the feed 
composition and conversion ratios for the participating monomers. 
TABLE 5 
______________________________________ 
50% of the structure is aliphatic (linear/branched) 
20% cyclic aliphatics 
30% aromatic 
(wt %) 
______________________________________ 
The hydrogenated resin had the properties set out in Table 6: 
TABLE 6 
______________________________________ 
NEAT HYDROGENATED RESIN PROPERTIES 
______________________________________ 
Softening point, R & B, .degree.C. 
87 
Initial Colour, Saybolt 26 
Colour Stability (Gardner) 5 hrs/175.degree. C. 
7.5 
Mn 730 
Mw 1020 
Mz 1525 
Mw/Mn 1.4 
Viscosity, mPa .multidot. s. at 120.degree. C. 
1110 
150.degree. C. 200 
160.degree. C. 140 
Aromaticity (wt % styrene) 23 
Cloud point, .degree.C. 
Melting point of EVA UL 15028/ECR-385/Microwax 
&lt;85 
86.degree. C. 30/45/25 
Melting point of EVA UL 0453/ECT-385 
&lt;70 
50/50 
ACID number, mg KOH/gr MAX 1 
Volatiles, 5 gr/5 hrs/175.degree. C., wt % 
2.3 
Flash point (.degree.C.) &lt;200 
______________________________________ 
The melt-viscosity versus shear rate is set out in FIG. 1. 
Table 7 shows comparatively the composition of a resin according to the 
invention against one obtained according to Maruzen U.S. Pat. No. 
4,952,639. 
TABLE 7 
______________________________________ 
Average Feed Blend Compositions 
(WT %) MARUZEN Invention 
______________________________________ 
C.sub.5 Diolefins 
25-75 10 
C.sub.5 Olefins 
10-45 25-46 
D/O Ratio 1-4 0.3-0.4 
Aromatics 10-50 18-26 
______________________________________ 
Next the hydrogenated resin was blended with blockcopolymer. 
Table 8 shows the block copolymers used: Stereon and Vector are Registered 
Trade Marks. 
TABLE 8 
__________________________________________________________________________ 
Characteristics of the Block Copolymers used 
Vector 
Vector 
Stereon 
K X Vector 
Vector 
Commercial Name 
4461 D 
4411 D 
840 A 139 S 4211 D 
4261 D 
__________________________________________________________________________ 
Nature SBS SIS SBS SBS SIS SBS 
Composition Triblock 
Triblock 
Multiblock 
Tri/Diblock 
Triblock 
Triblock 
Diblock wt % 0 0 not available 
16 0 0 
type linear 
linear 
tapered and 
linear linear 
linear 
radial 
Typical styrene content, 
43 44 42 40 29 29 
wt % (by NMR) 
Melt flow rate gr/10 min. 
23 40 13 20 13 12 
(ASTM D 1238) 
Hardness Shore A 
87 87 80 84 60 65 
(ASTM D 2240) 
__________________________________________________________________________ 
Blending may be by a Z-blade mixer such as a Winkworth-type at 140.degree. 
C. (usefully in the range of from 120.degree. to 155.degree. C.) from 60 
minutes to 3 hours under a nitrogen atmosphere to reduce degradation. 
Table 9 sets out the blend-ratio's for the different hot melt adhesive 
compositions prepared: 
TABLE 9 
______________________________________ 
In the 
Examples 
(typical) wt % 
______________________________________ 
Block Copolymer 22 
Resin 60 
Oil (paraffinic typically) 
18 
Antioxidant/such as phenolic type, Irganox, a 
0.2-1 
(Registered Trade Mark) 1010 from Ciba-Geigy 
______________________________________ 
Six blends were prepared of varying block copolymer type and using 
different resins 
The performance can be evaluated by reference to FIGS. 2 to 6. 
TABLE 10 
______________________________________ 
Not according to invention 
Blend 1 
C.sub.5 /C.sub.9 /Terpene resin/V 4461 D (Triblock SSS 
(linear)) The resin is made according to EP 132291 
Blend 2 
C.sub.5 /C.sub.9 /Terpene resin/Stereon 840 (Multiblock 
tapered SBS (radial)) 
Blend 3 
C.sub.5 /C.sub.9 /Terpene resin/KX 139 S(Tri/diblock SSS 
((linear)) 
Blend 4 
Terpene-aromatic resin/Resin L (Zonatac Lite)/ 
Stereon 840 A (multiblock tapered SBS(radial)) 
According to invention 
Blend 5 
Resin of Example/V 4461 D (triblock SBS (linear)) 
Blend 6 
Resin of Example/V 4411 D (Triblock SIS (linear)) 
______________________________________ 
In the Examples the softening point was determined by ring and ball (ASTM 
E-28). The GPC related data in the description and claims on Mn, Mw, Mz 
and Mw/Mn were calculated after measurements according to the following 
description. The calibration is set out in FIG. 1. 
GEL PERMEATION CHROMATOGRAPHY METHOD USED 
Resins are run on a GPC 201 Waters instrument equipped with four 
ultrastyragel columns. These columns are filled with a porous gel having 
pore sizes ranging from 10.sup.4 down to 100 Angstroms and a resolving 
power higher than that of microctyragel. 
The set of ultrastyragel columns was calibrated with polystyrene standards 
to obtain the "universal" calibration. With each sample a reference 
(sulfur)is injected to take into account the small variations of flow-rate 
of the pump. Elution time of sulfur is always assumed to be 100 and the 
calibration is expressed in terms of reduced elution time 0=100 t/ts where 
t is the elution time of species M and ts the elution time of sulfur. 
For polystyrene following calibration equation was obtained: 
EQU Ln M=53.4459-1.79226.theta.+0.0254066.theta..sup.2 -0.133993E-3.theta..sup. 
3 
From this relationship, the "universal" calibration equation is deduced: 
##EQU1## 
The calibration for the resins described in this patent was established by 
using 15 reference samples characterized by their number average molecular 
weight and intrinsic viscosity. 
Following calibration equation was thus obtained: 
EQU Ln M=62.6837-2.24478.theta.+0.0323598.theta..sup.2 -0.166704E-3.theta..sup. 
3 
Determination of the aromaticity in the reins 
A solution is made up of a known quantity of the resin (approximately 100 
mg) and of a known quantity of internal standard in carbontetrachloride. 
Of this solution 0.5 ml is taken, deuteroform is added and the 
quantitative .sup.1 H-NMR-spectrum is run. 
The integration of the aromatic region (between 8 and 6,4 ppm) is then 
compared with the integration of the internal standard. 
Based on the number of protons involved in the different areas for the 
aromatic area: 
styrene:5 
alpha-methylstyrene:5 
bisubstituted aromatics:4 
The weights of the compounds, and the molecular weights of the 
monomer-units and the internal standard, the weight percentage of aromatic 
functional groups can be determined. 
Advantages 
High cohesive strengths with SBS and SIS block colopymers can be achieved. 
Good performance hot melt pressure sensitive adhesive systems can be 
obtained using the low viscosity, good heat resistance, thermal stability, 
absence of skinning and good adhesion on olefinic polymer substances. The 
homogeneity obtainable is demonstrated by the absence of jerkiness in FIG. 
2 for the blends of the invention. The resin can provide good creep 
resistance particularly where the block copolymer contains less than 5 wt 
% of a diblock.