HK1021744A - Directly paintable thermoplastic olefin composition containing maleic anhydride-modified polymers - Google Patents

Description

Directly paintable thermoplastic olefin compositions comprising maleic anhydride modified polymers

The present invention relates to thermoplastic olefin compositions comprising maleic anhydride modified polymers and functionalized polymer additives.

Thermoplastic olefins (TPOs) are uncrosslinked blends of olefin polymers and polyolefin elastomers. They can be prepared by physical mixing in an internal mixer or by polymerization in a reactor. These materials are not paintable or coatable because the paint or coating consists of polar materials such as polyurethane, acrylic polymers, epoxy or melamine that have very poor adhesion to non-polar materials such as polyolefins. Adhesion promoters are typically used as a transition layer between the TPO substrate and the coating. This additional step adds to the cost of the product and the coating is very weak.

European patent application 662,496 discloses a paintable or printable polymer composition consisting of a polyolefin or polyolefin/rubber blend and 0.1 to 10% by weight of at least one polymer additive which is the reaction product of (a) a polyolefin or polyester modified with an unsaturated acid, ester or anhydride and (b) an amine, hydroxy or alkoxy terminated polyoxyethylene, polyoxypropylene or co-polymer of both, such as maleic anhydride modified polypropylene wax and methoxy terminated poly (ethylene oxide) glycol.

European patent application 634,424 discloses a blend of polypropylene and a maleated polypropylene with a polyetheramine reaction product. The above blends exhibit improved paintability, improved impact resistance and excellent molding flow compared to blends of polypropylene and maleated polypropylene reaction products. However, the compositions disclosed in EP662,496 and EP 634,424 are poor in durability.

The composition of the present invention comprises the following components by weight:

(1)100 parts of a thermoplastic olefin comprising the following (a) to (d):

(a) about 10% to about 60% of a propylene homopolymer having an isotactic index greater than 90%, or a propylene homopolymer having a propylene content greater than 85% and an isotactic index greater than 85% comprising ethylene and/or C_4-8Crystalline propylene copolymers of alpha-olefins;

(b) from about 30% to about 60% of an amorphous ethylene-propylene or ethylene-butene copolymer component optionally containing from about 1% to about 10% of a diene, said copolymer component being xylene soluble at room temperature and containing from about 30% to about 70% ethylene;

(c) from about 2% to about 20% of a semi-crystalline ethylene-propylene or ethylene-butene copolymer that is xylene insoluble at room temperature and contains greater than 75% but less than 92% ethylene; and

(d) about 5% to about 20% density of 0.91 to 0.96g/cm³An ethylene polymer having a melt index of 0.1 to 100g/10 min;

(2) a maleic anhydride content of about 2% to about 5% per 100 parts of thermoplastic olefin, molecular weight M_nAbout 2500 to about 25,000 of a maleic anhydride modified propylene homopolymer or an ethylene/propylene random copolymer;

(3) from about 5 parts to about 14 parts per 100 parts of thermoplastic olefin of a maleic anhydride grafted olefin polymer material selected from the group consisting of (a) - (b) having a maleic anhydride content of at least 0.3% but less than 3%:

(a) a maleic anhydride grafted polyolefin rubber comprising ethylene-propylene or ethylene-butene copolymer rubber, optionally containing from about 0.5% to about 10% diene, said copolymer rubber comprising from about 30% to about 70% ethylene, and

(b) a maleic anhydride-grafted propylene polymer material, wherein the propylene polymer material comprises essentially the following components (i) to (iii):

from about 10% to about 50% of a propylene homopolymer having an isotactic index of from about 80% to about 99%, or a copolymer selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene and CH₂= CHR α -olefin, wherein R is C_2-8And (c) propylene and an alpha-olefin as defined above in (i) (b), the copolymer comprising from about 85% to about 99% propylene and having an isotactic index of from about 80% to about 98%;

(ii) from about 3% to about 20% of a semi-crystalline, substantially linear copolymer component having a crystallinity of from about 20% to about 60% as determined by Differential Scanning Calorimetry (DSC), wherein the copolymer is selected from the group consisting of (a) - (c), (a) ethylene and propylene containing greater than 50% ethylene; (b) ethylene comprising from about 1% to about 10% alpha-olefin and from greater than 50% to 98% ethylene and alpha-olefin, propylene and alpha-olefin as defined in (i) (b) above; and (c) ethylene containing from greater than 50% to 98% alpha-olefin and an alpha-olefin as defined in (i) (b) above, said copolymer being insoluble in xylene at room or ambient temperature; and

(iii) from about 40% to about 80% of a copolymer component selected from the group consisting of (a) ethylene and propylene, wherein the copolymer contains from 20% to less than 40% ethylene; (b) ethylene, propylene and an alpha-olefin as defined in (i) (b) above, wherein the amount of alpha-olefin is from about 1% to about 10%, and the amount of ethylene and alpha-olefin is from 20% to less than 45%; and (C) ethylene comprising from 20% to less than 45% alpha-olefin and optionally from about 0.5% to about 10% diene and an alpha-olefin as defined above in (i) (b), the copolymer component (iii) being soluble in xylene at ambient temperature and having an intrinsic viscosity of from about 1.7 to about 3.0 dl/g, wherein the total amount of components (ii) and (iii) is from about 65% to about 80%, the weight ratio of components (ii)/(iii) is from about 0.1 to about 0.3, based on the total weight of the olefin polymer composition, and ethylene or C in components (ii) + (iii)_4-8The total content of alpha-olefins or mixtures thereof is less than 50%;

(4) a functionalized polymer selected from the following (a) - (c), reacted with an anhydride group of (2), (3), and (5) (if present):

(a) from about 2.7 to about 6 parts of an amine terminated polyalkylene glycol per 100 parts of thermoplastic olefin;

(b) from about 2 to about 6 parts per 100 parts of thermoplastic olefin of a hydroxylated polymer selected from the group consisting of (i) to (iii):

a hydroxylated polyethylene (i) a polyethylene (II),

(ii) a hydroxylated polybutene, and

(iii) hydroxylated polybutadiene; and

(c) from about 2 to about 6 parts of a mixture of (a) + (b) per 100 parts of thermoplastic olefin, wherein the ratio of (a) to (b) is from about 0.1 to about 0.9; and optionally

(5) From about 4 parts to about 15 parts of maleic anhydride per 100 parts of thermoplastic olefin, from about 2% to about 13% and a molecular weight M_nAbout 500 to about 3000 of maleic acidAn anhydride-grafted ethylene polymer having a high degree of grafting,

wherein (2) + (3) or (2) + (3) + (5) is at least 16 parts but less than 27 parts per 100 parts of thermoplastic olefin and (3) + (5) is equal to or greater than 10 parts per 100 parts of thermoplastic olefin when maleic anhydride grafted polyethylene is present.

Injection molded parts such as automobile bumpers made from such compositions can be directly coated with a polar paint or coating without the need for an adhesion promoter layer between the thermoplastic olefin surface and the paint.

Component (1) of the composition of the present invention is a thermoplastic olefin comprising the following components (by weight):

(a) from about 10% to about 60%, preferably from about 20% to about 50%, of a propylene homopolymer having an isotactic index greater than 90%, preferably from 95% to 98%, or a propylene homopolymer having a propylene content greater than 85% and an isotactic index greater than 85% comprising ethylene and/or C_4-8Crystalline propylene copolymers of alpha-olefins;

(b) from about 30% to about 60%, preferably from about 30% to about 50%, of an amorphous ethylene-propylene or ethylene-butene copolymer component optionally containing from about 1% to about 10% of a diene, said copolymer component being xylene soluble at room temperature and containing from about 30% to about 70% ethylene;

(c) from about 2% to about 20%, preferably from about 7% to about 15%, of a semi-crystalline ethylene-propylene or ethylene-butene copolymer that is xylene insoluble at room temperature and contains greater than 75% but less than 92% ethylene; and

(d) about 5% to about 20%, preferably about 7% to about 15%, density of 0.91 to 0.96g/cm³Ethylene polymers having a melt index of from 0.1 to 100g/10min, preferably from about 15 to about 50g/10 min. Ethylene homopolymers are preferred. However, copolymers comprising 8% or less of alpha-olefin comonomer may also be used.

Thermoplastic olefins are generally prepared by sequential polymerization in at least three steps. Component (a) can be prepared in a first reactor, components (b) and (c) in a second reactor, and component (d) in a third reactor. Alternatively, component (d) may be prepared in a second reactor, while components (b) and (c) are prepared in a third reactor. Polymerization conditions and polymerization catalysts are described in more detail in U.S. Pat. No. 5,302,454, the contents of which are incorporated herein by reference. Alternatively, the four components may be prepared separately and then blended together. Sequential polymerization is preferred.

C used in preparing thermoplastic olefin_4-8Alpha-olefins include, for example, butene-1; pentene-1; hexene-1; 4-methylpentene-1, and octene-1.

When a diene is present, it is typically butadiene; 1, 4-hexadiene; 1, 5-hexadiene, or ethylidene norbornene.

The amount of the thermoplastic olefin is 100 parts by weight.

Component (2) is a maleic anhydride grafted propylene homopolymer or an ethylene/propylene random copolymer having an ethylene content of from about 0.5% to about 4%, preferably from about 1% to about 3%. Propylene homopolymers are preferred. The polymers have a maleic anhydride content of from about 2% to about 5%, preferably from about 3% to about 4%, and a molecular weight M_nPreferably from about 2500 to about 25,000, and most preferably from about 3000 to about 10,000. The amount of component (2) is from about 8 to about 14 parts, preferably from about 10 to about 12 parts, per 100 parts of thermoplastic olefin.

Component (3) is a maleic anhydride-grafted olefin polymer material selected from the following (a) to (b):

(a) maleic anhydride grafted polyolefin rubbers comprising ethylene/propylene or ethylene/butene copolymer rubbers, optionally containing from about 0.5% to about 10%, preferably from about 2% to about 6%, of dienes, said copolymer rubbers comprising from about 30% to about 70%, preferably from about 40% to about 60%, of ethylene, and

(b) a maleic anhydride-grafted propylene polymer material, wherein the propylene polymer material comprises essentially the following components (i) to (iii):

from about 10% to about 50% of a propylene homopolymer having an isotactic index of from about 80% to about 99%, or a copolymer selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene and CH₂= CHR alpha-olefin(s),wherein R is C_2-8And (c) propylene and an alpha-olefin as defined above in (i) (b), the copolymer comprising from about 85% to about 99% propylene and having an isotactic index of from about 80% to about 98%;

(ii) from about 3% to about 20% of a semi-crystalline, substantially linear copolymer component having a crystallinity of from about 20% to about 60% as determined by Differential Scanning Calorimetry (DSC), wherein the copolymer is selected from the group consisting of (a) - (c), (a) ethylene and propylene containing greater than 50% ethylene; (b) ethylene comprising from about 1% to about 10% alpha-olefin and from greater than 50% to 98% ethylene and alpha-olefin, propylene and alpha-olefin as defined in (i) (b) above; and (c) ethylene containing from greater than 50% to 98% alpha-olefin and an alpha-olefin as defined in (i) (b) above, said copolymer being insoluble in xylene at room or ambient temperature; and

(iii) from about 40% to about 80% of a copolymer component selected from the group consisting of (a) ethylene and propylene, wherein the copolymer contains from 20% to less than 40% ethylene; (b) ethylene, propylene and an alpha-olefin as defined in (i) (b) above, wherein the amount of alpha-olefin is from about 1% to about 10%, and the amount of ethylene and alpha-olefin is from 20% to less than 45%; and (C) ethylene comprising from 20% to less than 45% alpha-olefin and optionally from about 0.5% to about 10% diene and an alpha-olefin as defined above in (i) (b), the copolymer component (iii) being soluble in xylene at ambient temperature and having an intrinsic viscosity of from about 1.7 to about 3.0 dl/g, wherein the total amount of components (ii) and (iii) is from about 65% to about 80%, the weight ratio of components (ii)/(iii) is from about 0.1 to about 0.3, based on the total weight of the olefin polymer composition, and ethylene or C in components (ii) + (iii)_4-8The total content of alpha-olefins or mixtures thereof is less than 50%.

The amount of component (i) is preferably from about 10% to about 40%, more preferably from about 20% to about 35%. When (i) is a propylene homopolymer, the isotactic index is preferably about 85% to about 98%. When (i) is a copolymer, the amount of propylene in the copolymer is preferably from about 90% to about 99%.

The amount of component (ii) is preferably from about 7% to about 15%. The crystallinity, as measured by DSC, is generally from about 20% to about 60%. Typically, the ethylene or alpha-olefin content, or when both are used, the amount of ethylene and alpha-olefin mixture is greater than 55% to 98%, preferably from about 80% to about 95%.

The amount of component (iii) is preferably from about 50% to about 70%. The ethylene or alpha-olefin content or the ethylene and alpha-olefin content of component (iii) is preferably from about 20% to about 38%, most preferably from about 25% to about 38%.

Component (3) (a) may be prepared with a ziegler-natta catalyst, a metallocene catalyst or a mixed catalyst, which may be amorphous or contain a crystallinity of from about 1% to about 10% as measured by DSC.

Component (3) (b) exhibits at least one melting peak at a temperature above 120 ℃ and at least one peak with respect to glass transition at a temperature of-10 ℃ to-35 ℃ as measured by DSC. In addition, these materials have a flexural modulus of less than 150MPa, typically from 20 to 100 MPa; the yield tensile strength is 10-20 MPa; elongation at break is greater than 400%; a tensile set at 75% strain of 20% -50%; a Shore D hardness of 20 to 35; haze value of less than 40%, preferably less than 35%, and no fracture (no brittle impact fracture) at-50 ℃ in Izod impact (Izod impact) test.

Suitable formula CH₂α -olefins of = CHR include, for example, butene-1; pentene-1; 4-methylpentene-1; hexene-1, and octene-1.

When a diene is present in component (3) (a), it is typically 1, 4-hexadiene, ethylidene norbornene or dicyclopentadiene. When a diene is present in component (3) (b), it is typically butadiene; 1, 4-hexadiene; 1, 5-hexadiene or ethylidene norbornene.

Component (3) (b) may be prepared by a polymerisation process comprising at least two steps, wherein in a first step propylene, or propylene and ethylene or an alpha-olefin, or propylene, ethylene and an alpha-olefin are polymerised to form component (i), and in a subsequent step a mixture of ethylene and propylene or an alpha-olefin, or propylene, ethylene and an alpha-olefin and optionally a diene, is polymerised to form components (ii) and (iii).

The polymerization can be carried out in the liquid, gas or gas-liquid phase using separate reactors, all of which can be carried out in batch or continuous mode. For example, it is possible to use liquid propylene as diluent for the polymerization component (i), the gas-phase polymerization components (ii) and (iii), and no intermediate step other than the partial degassing of propylene is required. The preparation of propylene polymer materials is described in more detail in U.S. Pat. No. 5,212,246, the contents of which are incorporated herein by reference.

The amount of the olefin polymer material (3) is about 5 to about 14 parts, preferably about 8 to about 12 parts, per 100 parts of the thermoplastic olefin. The olefin polymer material has a maleic anhydride content of at least 0.3%, but less than 3%, preferably less than 1%, and most preferably less than 0.8%. An amount of maleic anhydride equal to or greater than 3% will give a gel with poor adhesion and durability.

Component (4) is a functionalized polymer reactive with the maleic anhydride groups of components (2), (3) and (5), if present, and is selected from (a) amine-terminated polyalkylene glycols, such as polyethylene glycol, polypropylene glycol, copolymers of polyethylene glycol and polypropylene glycol, poly (1, 2-butanediol) and poly (1, 4-butanediol), and (b) hydroxylated polymers selected from (i) to (iii), (i) hydroxylated polyethylene, (ii) hydroxylated polybutylene, and (iii) hydroxylated polybutadiene. Amine-terminated polyethylene oxides are preferred.

When component (4) (a) is present, it is present in an amount of about 2.7 to about 6 parts, preferably about 2.8 to about 4 parts, per 100 parts of thermoplastic olefin, and when component (4) (b) is present, it is present in an amount of about 2 to about 6 parts, preferably about 3 to about 5 parts, per 100 parts of thermoplastic olefin. The mixture of (a) + (b) is also used in an amount of about 2 to about 6 parts per 100 parts of thermoplastic olefin, with the ratio of (a) to (b) being about 0.1 to about 0.9.

Optional component (5) is a maleic anhydride grafted ethylene polymer having a maleic anhydride content of from about 2% to about 13%, preferably from about 3% to about 6%. Ethylene homopolymers are preferred. However, copolymers containing 10% or less of the alpha-olefin comonomer may also be used. Molecular weight M of ethylene Polymer_nPreferably from about 500 to about 3000, more preferably from about 650 to about 2500; melting point is higherPreferably from about 90 ℃ to about 129 ℃, more preferably from about 92 ℃ to about 126 ℃, and preferably has a viscosity of from about 20 to about 1000, more preferably from about 100 to about 500 SUS (Saybolt Universal seconds) at 149 ℃ (ASTM D-88). When component (5) is used, it is used in an amount of about 4 to about 15 parts, preferably about 5 to about 10 parts, per 100 parts of the thermoplastic olefin, and the amount of (3) + (5) is 10 parts or more per 100 parts of the thermoplastic olefin.

The total amount of (2) + (3) or (2) + (3) + (5) is at least 16 parts but less than 27 parts, preferably from about 18 to about 22 parts, per 100 parts of thermoplastic olefin.

If non-polymeric additives such as conductive carbon black are used, they should be added after the functionalized polymer has reacted with the maleic anhydride grafted polymer. Alternatively, the adduct of the functionalized polymer and the maleic anhydride grafted polyolefin is prepared separately and then blended with the thermoplastic olefin.

The compositions of the present invention may also contain other conventional additives, such as antioxidants; a stabilizer; extender oils such as paraffinic and naphthenic oils; fillers, e.g. CaCO₃Talc and zinc oxide, or a flame retardant.

The components of the composition may be mixed or melt blended in open roll, internal mixers (Banbury or Haake mixers), and single or twin screw extruders.

The maleic anhydride-grafted polymers may optionally be preblended or they may be pre-reacted with component (4) before blending with the thermoplastic olefin. However, the former method is preferable.

In the following examples and comparative examples, the samples used for the tests were prepared by dry blending the components in a twin screw extruder at a temperature of 450 ° F and reaction mixing, and then pelletizing the resulting material. The pellets were injection molded into a pan, which was coated with Du Pont 872 white paint to a coating thickness of about 1.2-2 mils and cured at 250 ° F for 30 minutes. A grid pattern of squares, each approximately 1/4 inches in size, was scribed on the coated disc on the side opposite the gate area of the disc. Adhesive tape (3M 898) was pressed onto the paint and pulled off to test the amount of paint removed or paint adhesion. The% destroyed was recorded as the% of squares removed by tape after one pull. Durability was measured using a Taber abrasion tester with a type C wear head assembly (sizing head assembly) and a 1 pound load. The coated disc was placed in an oven at 70 ℃ for 1 hour, removed, and placed on the platform of an abrasion tester. The wear head is brought into contact with the coated surface and the disk is rotated for a specified number of cycles. The amount of paint removed from the complete circle subtended by the abrasion head is reported as% damage.

One set of criteria for acceptable paint adhesion is less than 10% failure (removed coating) as measured by adhesive tape and less than 20% of the paint removed after 25 cycles and 30% or less of the paint removed after 50 cycles using a Taber abrasion tester.

In this specification, all parts and percentages are by weight unless otherwise indicated.

Examples 1 to 7

Examples 1-7 illustrate the paint adhesion and durability of compositions comprising thermoplastic olefin (TPO), various amounts of maleic anhydride grafted olefin polymer material (MA-g-OPM), maleic anhydride grafted polypropylene (MA-g-PP) and amine terminated polyethylene oxide (atmeo), with or without maleic anhydride grafted polyethylene (MA-g-PE). The results are shown in Table 1.

In this table, the thermoplastic olefin comprises 55% of a propylene homopolymer, 3% of a semi-crystalline ethylene/propylene copolymer having a propylene content of about 10% and being insoluble in xylene at room temperature, 30% of an amorphous ethylene/propylene copolymer rubber having an ethylene content of 50% and being soluble in xylene at room temperature, and 12% of an ethylene homopolymer having a melt index of about 50g/10 min.

MA grafted OPM (1) is Exxelor VA-1803 ethylene/propylene rubber from Exxon chemical Company containing 0.7% grafted maleic anhydride.

MA grafted OPM (2) is a Royaltu 465 ethylene/propylene/non-conjugated diene terpolymer containing 0.4% grafted maleic anhydride, Mooney viscosity (ML 1+4 at 125 ℃) of 60 and an ethylene/propylene ratio of 75/25 available from Uniroyal Chemical Co.Inc.

The MA grafted polypropylene was Epolene E-43 maleic anhydride modified polypropylene wax available from Eastman Chemical Company.

The MA grafted polyethylene is Ceramer 67 maleic anhydride grafted polyethylene wax available from Petrolite Corporation.

ATPEO is an XTJ-418 monoamine-capped polyethylene oxide available from Huntsman Corporation.

The antioxidant is Irganox B225 from Ciba-Geigy, which is 1 part of Irganox 10102, 2-bis [ [3- (3, 5-bis (1, 1-dimethylethyl) -4-hydroxyphenyl- ]]-1-oxopropoxy) methyl]A mixture of 1, 3-propanediyl-3, 5-bis (1, 1-dimethylethyl) -4-hydroxyphenylpropionate stabilizer and 1 part of tris (2, 4-di-tert-butylphenyl) Irgasfos 168 phosphite.

TABLE 1
									Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Example 7
TPO	100	100	100	100	100	100	100
								MA-g-OPM(1)	5	5	10	10	5	10	10
MA-g-OPM(2)	5	5	-	-	-	-	-
								MA-g-PP	10	10	10	10	10	10	10
MA-g-PE	-	5	-	-	10	-	-
								ATPEO	3	3	3	4	3	3	4
Antioxidant agent	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Paint adhesion, failure%	3	0	6	0	0	9	0
								Durability, failure%
25 cycles	10	0	8	15	0	15	15
								50 cycles	20	0	8	20	12	15	25

Examples 1,3,4,6 and 7 show that mixtures of MA grafted polypropylene and MA grafted ethylene/propylene olefin polymer materials give good adhesion and durability. Examples 2 and 5 show that mixing MA grafted polyethylene with MA grafted polypropylene and MA grafted olefin polymer material results in a slight improvement in paint adhesion and improved durability.

Comparative examples 1 to 4

In Table 2, the ungrafted rubber used in comparative example 1 was a Dutral 4038 ethylene/propylene/ethylidene norbornene terpolymer rubber containing 4% ethylidene norbornene available from Enichem America Inc. All other components of the formulation were the same as in examples 1-7.

TABLE 2
						Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4
TPO	100	100	100	100
					Rubber composition	10	-	-	-
MA-g-OPM(1)	-	-	5	-
					MA-g-OPM(2)	-	-	5	-
MA-g-PP	10	20	5	10
					MA-g-PE	-	-	10	10
ATPEO	4	4	3	3
					Antioxidant agent	0.2	0.2	0.2	0.2
					Paint adhesion, failure%	45	0	54	28
Durability, failure%
					25 cycles	28	45	28	0
50 cycles	44	55	50	1

Comparative example 1 shows that poor adhesion and poor durability are obtained with the addition of a rubber that is not grafted with maleic anhydride. Comparative example 2 shows that OPM with higher amounts of MA grafted polypropylene but without MA grafting gives good adhesion but the durability is still poor. Comparative example 3 shows that mixing a small amount of MA grafted polypropylene (5 parts) with MA grafted OPM results in poor adhesion and poor durability. Comparative example 4 shows that mixing MA-grafted polypropylene with MA-grafted polyethylene without adding MA-grafted olefin polymer material results in good durability, but paint adhesion is poor.

Examples 8 to 11

Examples 8-11 demonstrate the paint adhesion and durability of compositions comprising thermoplastic olefin (TPO), maleic anhydride grafted olefin polymer material (MA-g-OPM), maleic anhydride grafted polypropylene (MA-g-PP) and three types of functionalized polymers, namely amine terminated polyethylene oxide (atmeo), Hydroxylated Polyethylene (HPE) and Hydroxylated Polybutylene (HPB). The results are shown in Table 3.

In Table 3, the thermoplastic elastomers, maleic anhydride-grafted olefin polymer materials (1) and (2), maleic anhydride-grafted polypropylene, amine-terminated polyethylene oxide and antioxidant were the same as in examples 1 to 7.

The maleic anhydride grafted OPM (3) is a propylene polymer material comprising (a) 30% of a propylene/ethylene random copolymer having an ethylene content of 3.3%, (b) 6.8% of a semi-crystalline ethylene/propylene copolymer component that is xylene insoluble at room temperature, and (c) 63.2% of an amorphous ethylene/propylene copolymer component that is xylene soluble at room temperature, the maleic anhydride grafted OPM (3) further comprising 1% grafted maleic anhydride.

MA-g-PE is Ceramer 67 maleic anhydride grafted polyethylene wax available from Petrolite Corporation.

HPE is a Unilin 350 hydroxylated polyethylene wax available from Petrolite Corporation.

HPB is a hydroxylated polybutene purchased from HPVM 2202 of Shell Chemical Company.

TABLE 3
						Example 8	Example 9	Example 10	Example 11
TPO	100	100	100	100
					MA-g-OPM(1)	-	-	-	5
MA-g-OPM(2)	-	10	10	-
					MA-g-OPM(3)	10	-	-	-
MA-g-PP	10	10	10	10
					MA-g-PE	-	-	-	10
ATPEO	3	-	-	-
					HPE	-	6	-	-
HPB	-	-	3	3
					Antioxidant agent	0.2	0.2	0.2	0.2
					Paint adhesion, failure%	0	0	0	0
Durability, failure%
					25 cycles	0	18	13	0
50 cycles	0	26	18	0

Comparative examples 5 to 9

In Table 4, the thermoplastic olefin, maleic anhydride-grafted olefin polymer materials (1) and (3), maleic anhydride-grafted polypropylene, amine-terminated polyethylene oxide and antioxidant were the same as in examples 8 to 13. Maleic anhydride grafted OPM (4) is the same as maleic anhydride grafted OPM (3) except that it contains 3% grafted maleic anhydride instead of 1%.

TABLE 4
							Comparative example 5	Comparative example 6	Comparative example 7	Comparative example 8	Comparative example 9
TPO	100	100	100	100	100
						MA-g-OPM(1)	-	10	10	-	-
MA-g-OPM(3)	-	-	-	10	-
						MA-g-OPM(4)	10	-	-	-	10
MA-g-PP	10	10	10	-	-
						ATPEO	3	2.5	7	3	3
Antioxidant agent	0.2	0.2	0.2	0.2	0.2
Paint adhesion, failure%	30	18	30	100	100
						Durability, failure%
25 cycles	45	35	50	100	100
						50 cycles	55	38	75	100	100

These comparative examples show that when MA-g-OPM contains 3% or more of grafted maleic anhydride (comparative examples 5 and 9), too much or too little ATPEO is used (comparative examples 6 and 7) and when MA-g-PP is not included in the composition (comparative examples 8 and 9), both adhesion and durability are unacceptable.

Examples 12 and 13

These examples illustrate the use of a mixture of an amine terminated polyalkylene glycol and a hydroxylated polymer as the functionalized polymer, component (4) of the composition of the invention. The results are shown in Table 5.

In Table 5, the thermoplastic olefin, the maleic anhydride-grafted polypropylene, the maleic anhydride-grafted olefin polymer materials (1) and (2), ATPEO and the antioxidant were the same as those used in examples 1 to 7. HPE and HPB were the same as used in examples 8-11.

TABLE 5
				Example 12	Example 13
TPO	100	100
			MA-g-OPM(1)	5	5
MA-g-OPM(2)	5	5
			MA-g-PP	10	10
ATPEO	3	3
			HPE	3	-
HPB	-	1
			Antioxidant agent	0.2	0.2
			Paint adhesion, failure%	0	0
Durability, failure%
			25 cycles	8	16
50 cycles	20	28

Other features, advantages and embodiments of the invention disclosed herein will be readily apparent to those of ordinary skill in the art upon reading the foregoing description. Thus, while particular embodiments of the present invention have been described in considerable detail, variations and modifications of these embodiments can be effected without departing from the spirit and scope of the invention as described and claimed herein.

Claims (8)

1. A composition comprising, by weight:

(1)100 parts of a thermoplastic olefin comprising the following (a) to (d):

(a) about 10% to about 60% of a propylene homopolymer having an isotactic index greater than 90%, or a propylene homopolymer having a propylene content greater than 85% and an isotactic index greater than 85% comprising ethylene and/or C_4-8Crystalline propylene copolymers of alpha-olefins;

(b) from about 30% to about 60% of an amorphous ethylene-propylene or ethylene-butene copolymer component optionally containing from about 1% to about 10% of a diene, said copolymer component being xylene soluble at room temperature and containing from about 30% to about 70% ethylene;

(c) from about 2% to about 20% of a semi-crystalline ethylene-propylene or ethylene-butene copolymer that is xylene insoluble at room temperature and contains greater than 75% but less than 92% ethylene; and

(d) about 5% to about 20% density of 0.91-0.96/cm³An ethylene polymer having a melt index of 0.1 to 100g/10 min;

(2) a maleic anhydride content of about 2% to about 5% per 100 parts of thermoplastic olefin, molecular weight M_nAbout 2500 to about 25,000 of a maleic anhydride grafted propylene homopolymer or ethylene/propylene random copolymer;

(3) from about 5 parts to about 14 parts per 100 parts of thermoplastic olefin of a maleic anhydride grafted olefin polymer material selected from the group consisting of (a) - (b) having a maleic anhydride content of at least 0.3% but less than 3%:

(a) a maleic anhydride grafted polyolefin rubber comprising an ethylene/propylene or ethylene/butene copolymer rubber, optionally containing from about 0.5% to about 10% diene, said copolymer rubber comprising from about 30% to about 70% ethylene, and

(b) a maleic anhydride-grafted propylene polymer material, wherein the propylene polymer material comprises essentially the following components (i) to (iii):

from about 10% to about 50% of a propylene homopolymer having an isotactic index of from about 80% to about 99%, or a copolymer selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene and CH₂= CHR α -olefin, wherein R is C_2-8A linear or branched alkyl group, and (c) propylene and an alpha-olefin as defined above in (i) (b), the copolymer comprising from about 85% to about 99% propylene and having an isotactic index of from about 80% to about 98%;

(ii) from about 3% to about 20% of a semi-crystalline, substantially linear copolymer component having a crystallinity of from about 20% to about 60% as determined by Differential Scanning Calorimetry (DSC), wherein the copolymer is selected from the group consisting of (a) - (c), (a) ethylene and propylene containing greater than 50% ethylene; (b) ethylene comprising from about 1% to about 10% alpha-olefin and from greater than 50% to 98% ethylene and alpha-olefin, propylene and alpha-olefin as defined in (i) (b) above; and (c) ethylene containing from greater than 50% to 98% alpha-olefin and an alpha-olefin as defined in (i) (b) above, said copolymer being insoluble in xylene at room or ambient temperature; and

(iii) from about 40% to about 80% of a copolymer component selected from the group consisting of (a) ethylene and propylene, wherein the copolymer contains from 20% to less than 40% ethylene; (b) ethylene, propylene and an alpha-olefin as defined in (i) (b) above, wherein the amount of alpha-olefin is from about 1% to about 10%, and the amount of ethylene and alpha-olefin is from 20% to less than 45%; and (C) ethylene comprising from 20% to less than 45% alpha-olefin and optionally from about 0.5% to about 10% diene and an alpha-olefin as defined above in (i) (b), the copolymer component (iii) being soluble in xylene at ambient temperature and having an intrinsic viscosity of from about 1.7 to about 3.0 dl/g, wherein the total amount of components (ii) and (iii) is from about 65% to about 80%, the weight ratio of components (ii)/(iii) is from about 0.1 to about 0.3, based on the total weight of the olefin polymer composition, and ethylene or C in components (ii) + (iii)_4-8The total content of alpha-olefins or mixtures thereof is less than 50%; and

(4) a functionalized polymer selected from the group consisting of the following (a) to (c), reacted with an anhydride group in the graft polymer:

(a) from about 2.7 to about 6 parts of an amine terminated polyalkylene glycol per 100 parts of thermoplastic olefin;

(b) from about 2 to about 6 parts per 100 parts of thermoplastic olefin of a hydroxylated polymer selected from the group consisting of (i) to (iii):

a hydroxylated polyethylene (i) a polyethylene (II),

(ii) a hydroxylated polybutene, and

(iii) hydroxylated polybutadiene; and

(c) from about 2 to about 6 parts of a mixture of (a) + (b) per 100 parts of thermoplastic olefin, wherein the ratio of (a) to (b) is from about 0.1 to about 0.9,

wherein (2) + (3) is at least 16 parts but less than 27 parts per 100 parts of thermoplastic olefin.

2. The composition of claim 1 wherein (4) is an amine terminated polyalkylene glycol.

3. The composition of claim 1 wherein (4) is a mixture of (a) and (b) and the total amount of (a) + (b) is from about 2 to about 6 parts per 100 parts of thermoplastic olefin, and the ratio of (a) to (b) is from about 0.1 to about 0.9.

4. The composition of claim 1 further comprising (5) from about 4 parts to about 15 parts of maleic anhydride per 100 parts of thermoplastic olefin having a maleic anhydride content of from about 2% to about 13% and a molecular weight M_nAbout 500 to about 3000 parts of maleic anhydride grafted ethylene polymer wherein (2) + (3) + (5) is at least 16 parts but less than 27 parts per 100 parts of thermoplastic olefin and (3) + (5) is equal to or greater than 10 parts per 100 parts of thermoplastic olefin.

5. The composition of claim 4 wherein (4) is an amine terminated polyalkylene glycol.

6. The composition of claim 4 wherein (4) is a mixture of (a) and (b) and the total amount of (a) + (b) is from about 2 to about 6 parts per 100 parts of thermoplastic olefin, and the ratio of (a) to (b) is from about 0.1 to about 0.9.

7. An injection molded article comprising the composition of claim 1.

8. An injection molded article comprising the composition of claim 4.