AU604243B2 - Novel propylene polymers - Google Patents

Description

11111- 11111

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority T1'v- dament COnltaji~ns I made tinder J cdon 49 and is correct for C C, Related Art: ot* I. Vt

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APPLICANT'S REFERENCE: FP-4075 Name(s) of Applicansl -E1-P a-so-P-roduc-ts, Comp an Address(es) of Applicant(s): 2400 South Grandview Avenue, Odessana, Texas, UNITED STATES OF AMERICA.

J 7 Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: NOVEL PROPYLENE POLYNERS Our Ref 57788 POF Code: 734/734 The following statement is a full desciiption of this invention, including the best method of performing it known to applicant(s): 6003q/1 1limits of this invention, while those of Comparative Examples ,1 This application is related to ,-pa di n pQ.l4*i~r-e Fe, 1286which pertains the process employed for the manufacture of the novel polymers of this invention.

BACKGROUND OF THE INVENTION In the manufacture of propylene homopolymers and copolymers, conventional polymerization techniques using unsupported catalyst result in the simultaneous production of substantial quantities of atactic polymer in addition, to the desired product of high crystallinity and isotacticity. Various methods have been employed for the purification and separation of these two polymers. The bycc 't |product, i.e. the atactic polymer of low crystallinity is being I utilized commercially as a component in various adhesive compositions, roofing materials, caulking compounds, etc.

CcC cc Recently, developments have been made of new catalysts which 'Sc Iare highly active and more stereospecific than the afore-mentioned conventional catalysts. The proportion of atactic polymer in the

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c polymers produced employing these catalysts are substantially relduced and therefore the polymer product generally does not require ces Iany purfication for removal of the atactic or low crystalline polymer. Because of trne rapid adaptation of existing polymer j facilities to the use of these new catalysts, there has been generated a serious shortage of low crystalline, atactic polymers.

i i I f/W It is therefo 'e an object of the present invention to provide a novel, substantially amorphous polymer of propylene and ethylene.

It is another object of the present invention to provide a novel amorphous polymer of propylene and ethylene, having improved physical properties.

THE FIGURES Figures 1A and 1B are comparative hot stage micrographs of two different polymers and Figures 2A and 2B are films of the same samples exposed to a)ide angle x-ray diffraction.

THE INVENTION SIn accordance with the present invention there is n provided a substantially amorphous random interpolymer of from about 10 wt to about 30 wt of ethylene, from about 65 to S. about 90 wt of propylene and from about 0 to about 15 wt of a C 4

C

8 alphaolefin, said interpolymer having a tacticity index m/r ranging between about 3 and about 4. When a third monomer is included, the preferred amount is between I about 5 and about 15 wt based on the total polymer weight.

The tacticity iandex m/r- is determined-directlyl 13 ii 1 C Nuclear Magnetic Resonance (NMR). The an i "r" i describe the stereochemistries of pairs o contiguous propylene groups bonded to one or more ylene groups, "m" referring to meso and to rac c. An m/r ratio of describes syndiotactic pol and ar m/r ratio of 2.0 a truly atactic material. A isotactic material theroectically will have a ratio proaching infinity and many by-product atactic polyme have sufficient isotactic content to result in ratios Oa~nd above It- hag heon fninr tha+ t-hp mr.-ati U -2- 2 A- According to a further embodiment of the present application there is provided a substantially amorphous binary random copolymer consisting of from 10 to 30 wt of ethylene and from 70 to 90 wt of propylene, said copolymer having a tacticity index m/r ranging between 3.0 and 4.0 and naving a propylene inversion value of 0.15 and below as 13 determined by 1C NMR Spectra.

The tacticity index m/r is determined directly by 13 C Nuclear Magnetic Resonance (NMR). The and "r" describe the stereochemistries of pairs of contiguous propylene groups bonded to one or more ethylene groups, "m" referring to meso and to racemic. An m/r ratio of describes syndiotactic polymer and an m/r ratio of 2.0 a truly atactic material. An isotactic material 0 000 o oo theroectically will have a ratio approaching infinity and many by-product atactic polymers have sufficient isotactic 0 0 content to result in ratios of 50 and above. It has been 0000 ooo found that the m/r ratio o0 0 00 0000 0*00 000 6 0 S0 0 IC 0 6 t r i i! ?i i:: i, i i i 1 substantially agrees with the number average sequence length n of like groups i.e. meso and racemic groups in case of propylene homopolymer produced under the same conditions as the random copolymer, except for the absence of ethylene in the feed. Thus, it was established that the tacticity is independent of comonomer content in the polymer. Also, the comonomer such as the ethylene is distributed throughout the polymer molecule in the most random fashion. The method used in calculating n for homopolymer is disclosed in J. C.

Randall, J. POLYM. SCI., POLYM. PHYS. ED., 14, 2083 (1976).

C c r The tacticity index m/r is obtained by inverting the r'/m' ratio calculated according to the method devised by H. N.

SCheng, MACROMOLECULES, 17, 1950 (1984).

e c-n The interpolymers of this invention are unique in that although they exhibit a birefringent spherulitic granular structure when examined by hot stage microscopy, they are Ssubstantially amorphous. Usually, truly amorphous materials will show no structure by this method. The formation of these S granules upon cooling implies that there is enough tacticity for short portions of the chain, i.e. ordered arrays of Z monomer without long range order, which would tend to form crastallites. The average length of the granules range between about 15 and about 50 microns, although occasionally larger grain sizes might be observed. The hot stage microscopy method is described in "The Light Microscopy of Synthetic Polymers", D.A. Helmsley, Oxford University Press, Oxford, England, 1984. The determinations are made by heating the samples on glass slides in a hot stage to 170 C and then slowly cooling them by turning off the heaters, while viewing the samples through a crossed polarizer. Photomicrographs -3-

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(400m) made af tho eooled camplzo, and moasuromonts are made of the largest dimension (=the length) of the granules.

Figure 1A shows a hot stage photomicrograph of a typical interpolymer of this invention (Example 3 of Table Figure S1B that of commercially available product (Commercial Sample C of Table 2) believed to be a purified atactic by-product polymer.

The interpolymers exhibit no significant crystallinity under wide angle x-ray diffraction ("X-ray Diffraction Methods In Polymer Science", L. E. Alexander, Krieger Publishing Company, Huntington, New York, 1979). In these tests the samples are placed betwee two thin films of

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Mylar and placed at the exit collimator of the x-ray tube.

A beam stop is used to block out the primary beam and flat C C films record the scattered radiation with a sample-to-film c t e distance of 30mm. The presence of no more than 2 concentric ,s rings on the exposed film indicates the presence of no S significant polymer crystallinity.

Figure 2A shows an exposed film using the same interpolymer of this invention as in Figure 1A, while Figure j o 2B is an exposed film of the same sample as of Figure lB. As seen in Figure 2A, there are no rings present indicating an Samorphous nature of the polymer sample, .i e \in Figure 2B there are 4 clearly defined rings, which indicate a high degree of crystalline order of the sample.

The novel polymer has a very low heat of fusion, typically less than about 0.6 cal/g, as determined by Differential Scanning Calorimetry techniques (DSC), a further oi4 indication of the amorphous nature of the polymer and the lack W of significant crystallinity in the polymer structure.

4A- In a preferred embodiment, the polymers of this invention may be prepared by a c c c c c 0 Cj C (CC

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C CN1 i I The polymers nf -th cinvention- a pb t c tl t C Stl process which comprises polymerizing from about 65 to 90 wt propylene, from about 10 to about 30 wt ethylene and from 0 to about 15 wt of a C 4

C

8 alpha-olefin at a temperature between about 130 and about 1750F in the presence of a particular catalyst composition. When a third monomer is used the preferred amount is between about 5 and about 15 wt based on the total polymer weight. Although the polymerization can be carried out in a batch reactor, it is preferred to utilize a continuous process to achieve the most random incorporation of the comonomer(s).

The pressure should be sufficient to maintain propylene in the liquid phase, usually pressures in the range between about 400 psig and about 550 psig are suitable. The preferred temperature is between about 150 and about 160 F.

Hydrogen is added to the polymerization reactor for control of polymer molecular weight and other properties at concentrations generally about 7 to 10 times the amount conventionally used in the manufacture of isotactic polymer.

Moreover, as the ethylene content of the interpolymer is increased it is necessary to increase the hydrogen concentration in the reactor to maintain a constant melt viscosity. As an exmample, for a 100% increase in ethylene content about a 50 to 150% increase in hydrogen is required.

The concentration of hydrogen in the total feed to the reaction zone generally ranges between about 0.7 and about mol and preferably between about 1.2 and about 2.5 mol mTk rr iF trrr nm nc h, C gtnInAn r n il4- A- -S E)I I EI

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5 A- In the above preferred embodiment, the specific catalyst composition contains a solid, supported catalyst component and an organoaluminum component. The supported catalyst component is comprised of an active C C C CCi CP C

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0 transition metal compound such as titanium tetrahalide mixed with an enhanced support comprised of magnesium halide and aluminum trihalide. The molar ratio of magnesium halide and aluminum trihalide is about 8:0.5-3.0 and preferably about 8:1.0-1.5.

The molar ratio of magnesium halide to titanium tetrahalide is between about 8:0.1-1.0 and preferably about 8:0.4-0.6. A critical feature of the solid supported catalyst component is that no electron donor compounds should be used in any of the catalyst manufacturing steps. Also, the c ec polymerization process using the catalyst should be carried out in the absence of added electron donors. The preferred S halides are chlorine.

Any of the general methods described in U.S. Patents t I No. 4,347,158 and 4,555,496 (hereby incorporated by reference in this application) can be used in preparing the solid oC supported catalyst component except that these methods must be modified to exclude the use of electron donor compounds.

S Briefly, the modified method involves co-comminuting magnesium halide and aluminum trihalide in the absence of an electron donor and then co-comminuting the catalyst support so formed with titanium tetrahalide, also in the absence of an electron donor.

The solid catalyst component is used in conjunction with an organoaluminum co-catalyst, which is a mixture of trialkylaluminum and alkylaluminum halide, wherein each alkyl group contains between 1 and 9 carbon atoms, and wherein the alkylaluminum halide contains at least one halide group. The preferred halide is chloride and the alkyl groups are preferably ethyl groups. The invention will be described FY -6ill hereinafter in connection with the preferred catalyst system.

The triethylaluminum content ranges between about 15 and about mol in the total organoaluminum component. At lower than triethylaluminum concentrations, the polymer productivity is drastically reduced and diethylaluminum chloride alone fails completely to promote polymerization. At higher than mol some of the physical properties of thsi polymer are affected in an undesirable manner. The use of diethylaluminum i chloride is not for the purpose of promoting polymerization but very importantly, to impart to the catalyst system the ability to produce polymer with desirable properties. The l 1 preferred co-catalyst is a mixture containing from about 40 to mol triethylaluminum and about 60 to about 40 mol'% diethylaluminum chloride. The molar ratio of total organoaluminum co-catalyst to titanium-containing catalyst component, i.e. Al/Ti ratio should range between about 50:1 and about 600:1, preferably between about 90:1 and about 300:1.

The polymerization is carried out in a stirred reactor at average residence times between about 1 hour and about 3 hours. Sufficient catalyst quantities are fed to the reactor to result in a polymer content in the reactor slurry of from about 30 wt and aboug 60 wt The reactor effluent is withdrawn from the reactor, and unreacted monomer and hydrogen is flashed from the pioduct polymer.

Various additives can be incorporated into the polymer, such as antioxidants, U.V. stabilizers, pigments, etc.

The compositions of this invention have excellent properties making them useful in a variety of applications, such as for adhesives, caulking and sealing compounds, roofing compositions and others. By varying the comonomer content in FY -7-

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~~~1~U0^51V the polymer and hydrogen addition to the reactor, it is possible to tailor the properties for any desired application. The important product properties include melt viscosity, ring and ball softening point, needle penetration and open time.

The melt viscosity at 375°F is determined by ASTM test method D-3236 using a Brookfield RVT Viscometer and a #27 spindle. Hydrogen is used to control molecular weight and thus melt viscosity. It has been found that at increased ethylene content more hydrogen is required to maintain a certain viscosity level. For hot melt adhesives the desired viscosity range is between about 1000 and 3bout 5000 cps at 375 0 F, while for other applications such as bitumen-modified product, the polymer component should have a viscosity above S5000 cps, preferably in the range between about 10,000 and about 25,000 cps.

The ring and ball softening point determinations are carried out using ASTM E-28 test method. The variables affecting the softening point are ethylene content of the polymer and the triethylaluminum concentration in the organoaluminum co-catalyst used in the polymerization process. A decrease in the ethylene content as well as in diethylaluminum chloride concentration in the co-catalyst both cause an increase in the ring and ball softening point. The preferred range for this property is between about 235°0 and about 270 0 F for the hot melt adhesive application.

Needle penetration is another test which measures the softness of the material, in this case by the resistance to penetration acording to ASTM test method D-1321.

Typically, the penetration values of the interpolymers of this FY -8i invention range between 25 and about 75 dmm (1 dmm=0. 1mm).

The same process variables affect this property as in the case of ring and ball softening point.

Perhaps the most important test of a hot melt adhesive is the open time. This test is an indication of the elapsed time available between adhesive application to kraft paper and bonding of a kraft paper laminate. This is a very important property for the user, as he must know how soon after applying the adhesive he must add the second sheet of paper. In this test, an 8 1/2" x 11" sheet of kraft paper, rough side-up is taped to a drawdown plate. A polymer sample is heated to 375°F along with a Bird drawdown applicator, When at temperature, the applicator is placed at the top of the kraft paper and a small puddle of molten polymer is poured near the edge, The polymer is drawn into a smooth film, and as soon as the bottom of the paper is reached, a stopwatch is started. At 10 second intervals, precut strips of kraft paper (rough side down, transverse machine direction) are placed across the film and pressed into place with a btb ,/hr.

After the last -trip is applied, and a t .ng perod of 5 minutes, the strips are removed in z k ik motion. The open time is defined t<he longest tmva *Ahin 30 l or more of the fiber remains, The open imes should preferable range between 10 and 60 seconds.

An additional benefit of the polyatir of this invention is that they contain extremely small quantltie's catalyst residues because of the very large productviiy fatms of the specific catalyst used in the poly~ 'here is no need to remove these small amounts the polymer, FY -9-

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,n The following examples illustrate the invention.

i EXAMPLES 1 8 Polymers were prepared in large scale continuous pilot plant operations, wherein monomers, hydrogen and catalyst components were separately and continuously charged to a stirred reactor, the total monomer feed rate corresponding to about a 2 hour residence time in the reactor. The organoaluminum compound of the catalyst system was a heptane solution of an equimolar mixture of triethylaluminum (TEA) and diethylaluminum chloride (DEAC).

The solid supported titanium tetrachloride catalyst component and a titanium content of about 2.5 wt and was prepared by a modification of the preferred technique disclosed in U.S.

Patent No. 4,347,158 modified only in that all process S steps were carried out in the absence of any electron donor compounds. The solid catalyst component was punped into the reactor as a 10 wt mixture in a blend of petrolatum and mineral oil in a 50/50 weight ratio. The two catalyst components were added at rates directly proportioned to the polymer production rates and in amounts sufficient to maintain the polymer solids concentration in the reactor slurry at values usually in the range between about 40% and about The catalyst productivity (Ib polymer/lb of Ti-catalyst component) was calculated in each case from the polymer slurry withdrawal rate, solid content in the slurry and tho titanium catalyst addition rate. The product polymer was separated from unreacted monomer, stabilized with IsonoxR 129 and then subjected to testing. Table 1 summarizes the pertinent operating coiiditions and the results of physical testing. The product characteristics of Example 1-6 fall within the claimed FY -9a- L I- limits of this invention, while those of Comparative Examples 7 and 8 reflect the insufficient amount of ethylene groups in the interpolymers, i.e. high softening point, low needle penetration, high heat of fusion.

Table 2 lists the physical properties of Examples 1-8 and also of fifteen atactic polymers (Commercial Examples A-O) obtained from various manufacturers in the United States, Europe and Asia. Commercial Sample A is a terpolymer of ethylene, propylene and a major proportion of butene-l, while the remaining samples are either propylene homopolymers or ethylene-propylene copolymers. Samples B, C, G and H are believed to have been produced in processes under conditions deliberately selected to yield relatively t* k 4 c 4 4.

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-9b- 4_ TABLE 1 EXAMPLE NO. 1 2 3 4 5 6 CCHP 7 CcMP 8 Reactor T"-mp. 157 150 154 154 157 142 155 155 Reactor Press. psig 456 434 466 484 491 495 448 442 Prcpylene lbs/hr ill il i1 ill 102 ill 112 124 Ethylene- lbs/hr 8.8 9.0 12.0 12.0 8.5 12.9 5.0 Hydrogen lbs/hr 0.14 0.05 0.06 0.10 0.06 0.14 0.10 07 AI/Ti mol ratio 311 289 301 299 263 291 299 533 Reactor Solids wt 60.5 47.' 51 51 32 38 61 59 Productivity lbs/lb Catalyst 55,420 34,390 33,520 35,500 23,950 30,260 37,440 20,680 Ethylene Ccntent wt 12.2 13.5 14.3 15.5 17.5 25.7 4.0 0 m/r Ratio or fl) 3.1 3.3 3.8 3.7 3.7 3.5 3.2 3.3 Average Granule Length Microns 15 20 12 18 25 15 38 No. of Rings (Wide angle X-ray) 0 2 0 2 0 0 1 4 AHF cal/g (DSC) 0.50 0.50 0.27 0.33 0.16 0.00 1.79 4.37 Melt Viscosity 3751F cps 3,000 15,000 7,750 3,780 9,210 7,900 2,100 2,800 Open Time sacs 10 20 20 30 20 >60 /(10 0 Ring and Ball Softening Point -F 266 257 252 251 253 237 279 304 Needle Penetration 0.1 mm 37 28 43 45 41 71 17 8 Co 0 a 0 TABLE 2 Ethylene m/r or Granule No of Rings wt% Rf Length X-ray dHF cal/g Melt Visc.

@375 0 F cps Open Tine Secs Soft Pt. Needle Pen.

OF 0.1 mm PRODUCT PROPER

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Example 1 2 3 ODp. 7 CCmp. 8 Commercial Sample A*

B

12.2 13.5 14.3 15.5 17.5 25.7 4.0 0 5.0 8.6 3 22.1 17, 1 0 0 0 0 0 0 0 0 0 3.1 3.3 3.8 3.7 3.7 3.5 3.2 3.3 2.1 2.1 1.6 49.0 99.0 2.7 2.9 2.1 2.0 2.1 2.5 2.7 2.5 1.9 15 20 12 18 25 15 38 50 0 33 45 0 5 18 90 130 98 18 92 148 170 75 40 0.50 0.50 0.27 0.33 0.16 0.00 1.79 4.37 0 .10 0.10 1.04 0.00 0.93 0.75 3.81 0.44 0.00 1.38 1.12 4.21 0.50 0.25 3,000 15,000 7,750 3,780 9,210 7,900 2,100 2,800 22,000 11,000 1,300 250 )500,,000 56,000 2,000 2,400 500 100 3,200 900 4,300 250 350 0 5 0 0 12 Terpolyrmer ethylene/prcpylene/butene 1 large concentrations of atactic polymer in the total polymer product. It is further believed that the atactic portions have subsequently been removed from the isotactic by-product by solvent Streatment. Samples D-F and I-0 are believed to be atactic polypropylene by-products. None of these commercial samples have the physical properties required of the polymer products of this in- .vention.

EXAMPLES 9 and Both experiments were performed in a 1-liter, jacketed autoclave equipped with a magnetically coupled stirrer. The temperature of the autoclave was controlled by the use of a mixture of equal weights of glycol and water as the heat transfer fluid flowo ing through the jacket. The temperature of this fluid was controlled by a microprocessor whose temperature indicator was an 1 iron/constantin thermocouple inside the autoclave. With this e c 4 4 4 t «t 4I C CC C 44 4 4 system, set point temperature could be maintained 0.2 C.

All monomers were polymerization grade, 99.9% pure, and were also passed through molecular sieve beds, as well as beds of copper catalyst for oxygen removal, prior to use. Hydrogen was ultra-high purity, 99.9% and used as is. Aluminum alkyl solutions were purchased as 25% W/W in normal heptane and were used as is. One wt catalyst slurried were prepared in degassed mineral oil using catalysts of the same type as that of in Examples 1-8. Prior to each use, the autoclaves were heated to 90 0 C with a slow nitrogen purge for 30 minutes.

After cooling to 30 0 C, the nitrogen atmosphere was replaced with a propylene purge. Alkyl solutions and catalyst slurries were prepared in septum vials in dry boxes (nitrogen atmosphere), purged with nitrogen upon removal, andpressurized slightly to avoid contamination. Alkyl solutions and catalyst slirries were introduced into the reactors using hypodermic syringes, previously cleaned with de-ionized water, dried at 120 C, and purged with nitrogen prior to use. In Example 9, 0.34 ml TEA, 0.34 ml DEAC (Al 1.77 x 10 3 mol/1), and 0.58 nil of 124 catalyst slurry W/W titanium content) were added .ie autoclave. Hydrogen was added to equal a partial pressure of 70 psig. 0.6 liters of propylene was intorduced tusing a sight guage and nitrogen pressure. The reactor content was heated to 60 C and maintained while stirring at 500 rpm. As soon as the temperature stabilized at (5-10 minutes), ethylene was added to the reactor to maintain a constant overpressure of 50 psig greater than the reactor pressure. After 1 hour, the temperature was lowered and excess propylene vented. The ethylene-propylene copolymer was dried under vacuum at 40°C overnight. Example 10 was FY -13i carried under the conditions of the previous example except that 0.1 liter of butene-1 and 0.5 liter of propylene was charged to the autoclave instead of the 0.6 liters of propylene of Example 9. The resulting terpolymer was dried as before.

Table 3 lists the pertinent physical properties of the products of Examples 9 and TABLE 3 ;i r

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i ii; ii: :i i i h 8' EXAMPLE NO. 9 Ethylene wt 21.1 Butylene wt m/r 3.3 Average Granule Length-microns 22 No. of Rings X-ray 0 S H -cal/g 0.03 Melt Viscosity 375 F cps 2810 Open Time secs 60 Softening Point OF 260 Needle Penetration 0.1 mm 71 Catalyst Efficiency Kg/g 41.2 COMPARATIVE EXAMPLES 11 and 12 These examples were carried out using the described in connection with Example 9 except for co-catalyst addition. In Example 11 0.68 ml TEA exclusively while in Example 12 the same amount of was added. Table 4 lists the pertinent data comparative examples.

23.3 9.2 4.8 0 0.00 3250 237 72 34.6 procedure the alkyl was used DEAC only of these I I TABLE 4 EXAMPLE NO.

Co-Catalyst

TEA

DEAC

Catalyst Efficiency Kg/g Ethylene wt COMP. 11 COMP. 12 100% 40.0 18.1 100% 0.0 m/r 4.2 Melt Viscosity 3750 cps 3700 Open Time secs 60 Softening Point F 275 Needle Penetration 0.1 mm 43 As seen from the above data, the use of 100% TEA instead of a mixture of TEA and DEAC (as in Example 9) S resulted in a higher m/r ratio of the polymer product. Also, S the softening point and needle penetration values were affected in a detrimental way. The use of 100% DEAC as co-catalyst resulted in no formation of polymer.

It is to be understood that many alterations and modifications can be made to the polymers of this invention.

All such departures are considered within the scope of this invention as defined by the specifications and appended claims.

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Claims (15)

1. A substantially amorphous random interpolymer of from wt to 30 wt of ethylene, from 65 to 90 wt of propylene and from 0 to 15 wt of a C 4 C 8 alpha-olefin, said interpolymer having a tacticity index m/r 13 ranging between 3 and 4 as determined by 1C NMR spectra.

2. An interpolymer according to claim 1 of ethylene and propylene only having a tacticity index between 3 and 4.

3. An interpolymer according to claim 1 wherein the alpha-olefin is butene-1.

4. An interpolymer according to any one of claims 1 to 3 exhibiting no significant crystallinity as determined by the presence of no more than 2 rings under wide angle x-ray diffraction. An interpolymer according to any one of claims 1 to 4 having a heat of fusion of less than about 0.5 cal/g.

6. An interpolymer according to any one of claims 1 to having a viscosity in the range between 1000 and 25,000 cps at 375 0 F.

7. An interpolymer according to any one of claims 1 to 6 having a ring and ball softening point between 235 0 F and 270 0 F.

8. An interpolymer according to any one of claims 1 to 7 having a needle penetration in the range between 25 and dmm.

9. An interpolymer according to any one of claims 1 to 8 having an open time between 10 and 60 seconds. A substantially amorphous binary random copolymer consisting of from 10 to 30 wt of ethylene and from 70 to wt of propylene, said copolymer having a tacticity index m/r ranging between 3.0 and 4.0 and having a propylene inversion value of 0.15 and below as determined by 13C NMR Spectra.

11. A copolymer according to claim 10 having a heat of fusion of less than about 0.6 cal/g.

12. A copolymer according to any one of claims 10 or 11 having a viscosity in the range between, abot 1000 and a9e4 25,000 cps at 375 0 F. t3, A copolymer according to any one of claims 10 to 12 17 having a ring and ball softening point between -abeut 235°F and aeut -300°F.

14. A copolymer according to any one of claims 10 to 13 having a needle penetration in the range between -abo and 75 dmm. A copolymer according to any one of claims 10 to 14 having an open time between- abh 10 and a.4ebt 60 seconds.

16. A copolymer according to any one of claims 10 to having a total ash content of less than about 500 ppm.

17. A copolymer according to any one of claims 10 to 16 having a titanium content of no more than about 2 ppm.

18. An interpolymer as claimed in claim 1 substantially as hereinbefore described with reference to any one of the examples other than the comparative examples.

19. A copolymer as claimed in claim 10 substantially as hereinbefore described with reference to any one of the examples other than the comparative examples. DATED: 16 July 1990 PHILLIPS ORMONDE FITZPATRICK Patent Attorneys for: EL PASO PRODUCTS COMPANY