JPS5914065B2 - elastomeric thermoplastic - Google Patents

Description

[Detailed description of the invention] F5 The present invention relates to elastomeric thermoplastics.

Elastomeric thermoplastics are known (U.S. Pat.
No. 758643 and No. 3835201. Such elastomeric thermoplastic blends are used in the production of molded or extruded articles such as decorative and structural parts of automobiles. Such parts can also be painted (see US Pat. No. 3,873,348). In order to provide sufficient melt flow properties for processing, Elas 35 tomeric thermoplastics for molding and extrusion purposes are generally limited to low molecular weight materials.

This can be obtained directly by polymerization or indirectly by cutting the high molecular weight material during processing. The present invention allows the use of high molecular weight elastomeric materials without cutting the polymer by incorporating a plasticizer such as a hydrocarbon oil.

In the present invention, the processability and mechanical properties of the resulting blend were improved by using carbon black with high reinforcement and low agglomerated structure. Surprisingly,
Physical properties such as tensile strength, flexural recovery and stress-strain properties and spiral flow characteristics of elastomeric thermoplastics such as copolymers of ethylene and higher α-olefins of C3 to ClO and crystalline polyolefin resins such as polypropylene. from about 10 to about 121 parts (based on 100 parts of ethylene copolymer), preferably from about 30 to about 8 parts, of carbon black with high strength and low agglomerated structure.
It has been found that improvements can be made by blending 0 parts into the thermoplastic. The blending procedure is such that the carbon black is incorporated primarily into the elastomer phase. Conventionally, good viscosity or melt flow properties have been obtained by using low viscosity polymers obtained by cutting or limiting the molecular weight of polymers, but naphthenic or paraffinic oils are often used in blends of such thermoplastics. It has also been found that such properties can be obtained by incorporating a plasticizer such as. If a plasticizer is used, it is important to blend the plasticizer into the elastomer phase and then blend the plasticizer/elastomer blend with the crystalline polyolefin. Within the scope of the present invention, favorable results have been obtained when the plasticizer is used with carbon black, which has high reinforcing properties and low agglomerated structure.
It can be used simultaneously with any conventional filler. The thermoplastics of this invention are useful in molding and extrusion molding, such as injection molded automotive decorative and structural parts.

The ethylene/higher alpha olefin copolymers and terpolymers may be prepared by any conventional method, and their preparation is not part of this invention.

US Patent No. 3,678,019 (UK Patent No. 135,069)
A method for preparing a copolymer according to No. 9) is described.

A preferred ethylene/higher α-olefin copolymer is ethylene propylene rubber, hereinafter abbreviated as R.

A preferred ethylene/higher α-olefin interpolymer includes ethylene, propylene, and ENB (5-ethylidene-2-norbornene), and the terpolymer is hereinafter abbreviated as EPDM. Such copolymers contain about 20 to about 90 mole percent ethylene, preferably about 30 to about 80 mole percent ethylene, and about 90 to about 20 mole percent, preferably about 80 to about 30 mole percent propylene, while the terpolymer contains about 10 to about 90 mole percent ethylene, about (a) to about 1
0 mole% propylene and up to about 30 mole% ENB
including. Copolymers and terpolymers suitable for use in the present invention have a number average molecular weight as measured by membrane osmometer of from about 25,000 to about 1,000,000, preferably from about 50,000 to about 500,0001. From about 75,000 to about 350,000.

Crystalline polyolefin resins suitable for use in the present invention include ethylene, propylene, butene-1, benzene-1, 4
- It is a high molecular weight resin obtained by polymerizing olefins such as methylbenzene. Polypropylene having less than about 12% by weight of soluble polymer in boiling heptane is preferred. Crystalline polymeric copolymers of ethylene and propylene may also be used. Polyolefin resins also include polyethylene and polypropylene modified with higher α-olefins. Preferred carbon blacks for use in the present invention have high enhancement ability and low agglomerated structure.

High wear furnace blacks (HAF) are preferred, particularly low construction high wear furnace blacks (HAF-LS). Blacks suitable for use in the present invention have a particle size of about 100 to about 600 A1, preferably about 20 A1.
0 to about 450A and a surface area of about 25 to about 150A.
m2/9, preferably about 40 to about 100 m2/9. The high-enhancement blacks used in the practice of this invention generally provide products with improved physical properties over products made using low-enhancement blacks.

That is, physical properties such as extensibility, tensile product, and heat strain are improved by the use of highly reinforcing blacks. The use of low structure blacks is necessary to obtain the blends of this invention with improved processability as determined by spiral flow measurements. It has therefore surprisingly been found that not only the physical properties of the blends of the present invention but also the processability of such blends can be improved by incorporating a highly reinforcing and low structure black such as HAF-LS. did. HAF
- When LS black is incorporated into the blends of the present invention, the bonding rubber is lower than when similar blends are incorporated with the same amount of general purpose furnace black (GPF) or other conventionally used carbon blacks. Another feature of the present invention is that it can be obtained in a large amount.

The higher the amount of bound rubber, the more carbon-polymer interactions, such as carbon-polymer-bonds. This is preferred because it enhances the rubber-like properties, ie, partially crosslinked rubber-like properties. See "RubberAge" by A.M. Gessler, Vol. 101, p. 55 (1969). It has also surprisingly been found that HAF-LS blacks can be more easily blended into the blends of the present invention than other conventional blacks such as GPF blacks.

This is surprising since it is generally recognized by those skilled in the art that it is easy to blend elastomers and carbon blacks when the black particles are large and the black structure is high. Thus HAF-11. ．． It is believed that GPF black can be more easily blended with the blends of the present invention than S black. Regardless of the ethylene propylene copolymer or terpolymer used, HAF-LS black is easier to blend at total black concentrations of 35 parts (for 100 parts of ethylene copolymer) or higher. An important aspect of the blends of this invention is that they can be painted by conventional methods, with or without the use of oil for plasticization.

In general, oils cannot be blended with crystalline polyolefins such as polyethylene and polypropylene because when blended with polyolefins at temperatures above the polyolefin's melting point, the oil will leach onto the recrystallized surface. The present invention provides a product that is oil-free on the surface and can be painted by conventional methods. One suitable method that may be used to coat the elastomeric thermoplastics of the present invention is by wiping with a solvent or by powder cleaning with a 1.5% solution of RidOline 72 followed by several rinses. This is a method of cleaning a molded part of the present invention. A final rinse with deionized water removes all traces of dirt, moisture, oil, fingerprints, mold release agents, plasticizers, etc. The molded part is then dried and treated with Seibert Oxiderm containing chlorinated polyolefin (
Seibert Oxiderm) (APlOO6) or by UV surface treatment to improve the coating adhesion. After this surface treatment, Durethane, Lacquer Primer 32
Prime with a Lutker primer such as 906 or an enamel primer such as Duurethane Enamel Primer 33104 or 33198.

Although these primers are not critical, they are generally used to shade black substrates. The primed surface is baked at approximately 2400F (116C) for approximately 20 minutes and coated with PPG-based (flexible polyurethane) or Dupont Dexra-1 (D
Topcoat with exIar system (flexible acrylic enamel). The top coated surface is then heated to approximately 250'F (121°C).
) for about 30 to 40 minutes. Primer should be at least 0.8 mil thick with 2 coats and 3 coats with top coat.
Preferably, multiple coats are applied to a thickness of at least 1.8 mil. The elastomeric thermoplastics of the present invention have satisfactory volume resistivities and can therefore be coated by conventional electrostatic coloring methods. If the black is 31% based on the total weight of the blend and black, the volume resistivity is 10-7Ω?
It is. This resistivity is a satisfactory value for conventional electrostatic coating methods. It may be desirable to use very high molecular weight ethylene-propylene copolymers or terpolymers in the blends of the present invention.

These high molecular weight EP polymers are useful for exterior surfaces of automotive parts requiring strength, resilience, stiffness, etc.
These properties are usually only obtained through the use of vulcanized rubber. Such high molecular weight polymers have not been satisfactory to date. This is because its viscosity and rheological properties were inadequate to produce the good processability and thermal fluidity necessary for injection molding of such blends. about 5 to about 150 parts of hydrocarbon oil, such as naphthenic and/or paraffinic oil, preferably about 5 parts
from about 100 parts, more preferably from about 10 to about 80 parts (
100 parts of EP copolymer) to high molecular weight EP
It has been found that when incorporated into DM/crystalline polyolefin blends, the blends are easily injection molded due to improved viscosity and rheological properties.

When blending, the bulk of the oil must be uniformly dispersed in the elastomer phase before blending with the crystalline polyolefin. Therefore, the use of oil in the present invention is advantageous in various respects.

The first is that the viscosity limit, which previously existed in order to obtain satisfactory processing behavior of engineered monolithic thermoplastics, has been removed. This allows the use of high molecular weight EP copolymers and/or terpolymers with the required structural properties for various products such as the external surfaces of automobile parts. Another advantage is the use of oil instead of cutting the polymer as a means of adjusting viscosity. Thus, economic advantages were given. The use of crystalline polyolefins and/or terpolymers and oils as described herein provides improved physical properties such as improved rebound and significantly enhanced extensibility regardless of the type of carbon black used. It has been found that an improved product is obtained. However, such properties are maximized when the carbon black is HAF-LS black as mentioned above. When the hydrocarbon oils described above are used in the present invention, the preferred filler is carbon black, and any conventional filler may be used, although carbon black, which has high reinforcing properties and low agglomerated structure, is most preferred.

Examples of non-black fillers suitable for use in the present invention when hydrocarbon oils are used include inorganic inert materials and organic coupling agents.

Examples of such inorganic inert materials are ground precipitated calcium carbonate, calcined hydrated standard kaolin clay, precipitated hydrated silica and silicates, especially calcium and magnesium silicates. Examples of organic coupling agents suitable for use in the present invention include halosilanes, titanates, and the like. Examples of carbon blacks suitable for use in the present invention when hydrocarbon oils are used include channel blacks such as MPC and CC, SRF, HMF, CF, FF, HAF, ISAF.
Furnace black such as l and SAF, MT and F
Includes thermal black like T.

The unvulcanized elastomeric thermoplastics of this invention generally have a
5 to about 30 parts, preferably about 80 to about 50 parts of oil-containing ethylene copolymer and/or terpolymer, about 1
5 to about 70 parts, preferably about 20 to about 50 parts of crystalline polyolefin. The crystalline polyolefin may be a single homopolymer or a mixture of crystalline polyolefins (eg, polypropylene or a 50/50 blend of polypropylene and polyethylene). When incorporated into the blends of the present invention, the appropriate amount of HAF-LS black is preferably about 20 to about 200 parts, more preferably about 30 to about 12 parts per oil-containing ethylene copolymer and/or terpolymer.
0 parts, most preferably about 35 to about 80 parts.

Two-phase elastomeric thermoplastics within the scope of the present invention include ethylene copolymers and/or terpolymers, crystalline polyolefins, and hydrocarbon oils, as described above.

A surprisingly important feature of this two-phase elastomeric thermoplastic is that both phases are continuous and the average distance between phase boundaries is less than about 1 micron. Thermoplastic blends similar to those of the present invention typically consist of two phases, one continuous and one discontinuous, with an average distance between phase boundaries greater than about 1 micron.

By controlling the type of polymer, composition, molecular weight and/or use of plasticizing oil, it is possible to produce two-phase thermoplastics in which both phases are continuous and the average distance between phase boundaries is less than about 1 micron. There was found. The two-phase structure of the blend is determined by injection molding test specimens followed by extraction of the amorphous phase using boiling n-heptane for 24 hours.

This operation removes the soluble elastomer phase and leaves the crystalline polyolefin phase. After drying, the polyolefin phase is ground in liquid nitrogen. The fractured surface is then coated with a thin layer of carbon/carbon and gold by vacuum deposition and observed under a scanning electron microscope. The nature of the polyolefin phase was determined by this method and the distance between phase boundaries was found to be less than about 1 micron. A preferred method of blending the compositions of this invention is to first create a masterbatch of elastomer and filler.

This is done by blending the elastomer and filler in a Banbury mixer. This masterbatch is then fed together with the crystalline polyolefin into a continuous mixer such as an extruder to continuously blend the two. A predetermined amount of masterbatch is blended with a predetermined amount of crystalline polyolefin in a Banbury mixer. It is also within the scope of this invention to first blend a predetermined amount of filler and elastomer in a Banbury mixer, and then introduce a predetermined amount of crystalline polyolefin into said Banbury mixer and blend with the elastomer/black blend. It is within. Here, the blending in the Banbury mixer is carried out at a temperature of about 40 to about 220°C.
Do this for minutes. If a hydrocarbon oil is used, it is preferred to add the oil before blending the elastomer or elastomer/black masterbatch with the crystalline polyolefin. The invention and its advantages are further illustrated by the following examples.

Example 1 Four types of samples were prepared.

Each used a different carbon black. Each sample is mu
[The viscosity is 40 at 100°C, and the viscosity measured with a capillary rheometer is 100f/1>-! and 3.5×1 at 200℃
04 Boaz and contains about 5% by weight of ENB.
60 parts by weight, 40 parts by weight of polypropylene, 45 parts by weight of carbon black, and 0.3 parts by weight of calcium stearate. Each of the four samples was first coated with carbon black and E.
PDM is cooled with a Banbury mixer under conditions (starting temperature 25
-30°C, take-out temperature 110-121°C) and mixed for 3 minutes.

Polypropylene is added to this masterbatch and heating conditions (
Starting temperature 150-160℃, take-out temperature 188-20℃
4° C.) for an additional 3 minutes. Samples were tested. The results are shown in Table 1 below. The surface areas of the black circles in Table 1 are as follows.

It is clear from Table 1 that the mechanical properties of the resulting thermoplastic blend are improved when a relatively strong (small particle size) black is incorporated into the thermoplastic blend.

This becomes clear when comparing the properties of the resulting thermoplastics, such as % bonded rubber, % elongation, tensile product, and heat strain. It can also be seen from Table 1 that the use of HAF-LS black maximizes the spiral flow. Example 2 Four additional samples were prepared according to Example 1, except that instead of blending the black into the EPDM first, all ingredients were blended in the Banbury one at once.

Table 2 shows that it is disadvantageous to blend all components at once. This disadvantage is thought to be due to the fact that the black is not sufficiently dispersed with this mixing method. Example 3 Two elastomeric thermoplastic samples were prepared.

One is formulated with hydrocarbon oil and the other is not. Both samples contained 30 parts polypropylene and had a melt flow of approximately 129/10 minutes (measured by ASTM D1238). The sample containing no oil has an Mn of about 35,000 and a viscosity of 100 seconds1,2.
70 EPDM which is about 3,5 x 104 Boas at 00℃
Contains 1%. Samples containing oil should be weighed in equal amounts of 70
The EPDM containing the oil has an Mn of about 140,0001 and a viscosity of about 1.
It was about 3.6 x 104 boads at 00 sec-1 and 200°C. Blends containing oil have a viscosity of 100 s−1,
The oil-free blend had a viscosity of -100 s - 11200, while the oil-free blend had a viscosity of about 1.6 x 104 boads at 200°C.
It was approximately 4.2 x 104 boads. This example shows that although the initial viscosities of the elastomeric phases are nearly equal, the viscosity of the oil-containing blend is greatly reduced when blended with polypropylene.

Therefore, thermoplastic samples containing oil are more easily processed than those without oil. All Mn measurements were performed using a membrane osmometer, and all viscosity measurements were performed using an Instron capillary viscometer.

Example 4 (a) Mn containing 68 wt% ethylene and 5.1 wt% ENB is about 140,000 (7) EPDM 70
and (b) 30 parts of polypropylene with a melt flow of about 59/10 minutes in a Banbury mixer for 10 minutes.

After blending was completed, the blend had a high viscosity, so it was very difficult to mold it into a mold. The blended material contained large chunks of unmixed EPDM and was not useful as an elastomeric thermoplastic. In this example, if a hydrocarbon process oil is not used, high molecular weight E
Blends of PDM have not been shown to be useful for preparing elastomeric thermoplastic blends. Example 5 75 parts (for 100 parts EPDM) of Flexon (
FlexOn) 876 (hydrocarbon process oil),
A composition was prepared according to Example 4 except that it was first blended with EPDM on a heated battery (start temperature 150-160°C, discharge temperature 188-204°C) and then blended with polypropylene for 3 minutes.

The properties of the obtained thermoplastic are shown in Table 3 below.

This example illustrates the need for hydrocarbon processing oils in the preparation of elastomeric thermoplastics containing high molecular weight EPDM.

Example 6 An elastomeric thermoplastic is prepared using the ingredients shown in Table 4.

The EPDM and filler were first blended on a Banbury unit under cooling conditions as shown in Example 1. As shown in Example 1, polypropylene was added to the resulting masterbatch and blended for an additional 3 minutes under heated mixing conditions. The EPDM used in these experiments had a 'Mn of 140,000 as measured by a membrane osmometer, an ethylene content of 68% by weight, an ENB content of 5.1% by weight, and a proportion of Flexon 876 (a hydrocarbon process oil) per 100 parts of elastomer. ) 75 copies. The melt flow rate of polypropylene is 230℃,
It was 59/10 minutes at 21609. The above table shows the use of non-black fillers in the present invention.

Example 7 A sample was prepared according to the procedure set forth in Example 1 except using the following ingredients.

60 parts by weight of EPDM containing 5% by weight ENB6O with a Mn of about 55000 and ethylene with a Mv of about 70.0.
00 polypropylene, 45 parts by weight of the black shown in Table 5, and 40 parts of Samper 2280 (hydrocarbon process oil) per 100 parts of EPDM.
Department. The resulting elastomeric thermoplastic samples were tested as described above and the results are shown in Table 5 below. The table above also shows the advantage of using hydrocarbon process oils in the present invention. It is also clear from the above table that HAF-LS blacks produce superior results among conventional blacks when using hydrocarbon process oils. Example 8 Two elastomeric thermoplastic compositions were prepared from relatively low molecular weight EPDM.

One contained hydrocarbon processing oil (Sampa 2280) and the other did not. The compositions were prepared in Banbury following the preferred procedure of first blending the black (and optionally oil) with EPDM and then blending with polypropylene. (゛) Outer helmet Rg)
(2) Polypropylene has a melt flow of 59/10 minutes at 230°C and 21609.

It is clear from the above experiments that relatively low molecular weight EPDM is suitable for use in the elastomeric thermoplastics of the present invention.

Example 9 Polypropylene (5% n-heptane soluble, Mv7O,O
OO was prepared by (a) EPDM1 having a Mn of about 190,000, an ethylene content of about 60% by weight, and an ENB content of about 5% by weight;
b) Blended with Sampai 2280.

The weight ratio of the components is 36.9/45.1/18.0 respectively.
It was hot. Blend in a Banbury mixer for 6 minutes.
Blend temperature is 170°C at the end of the blending cycle
The above was carried out. Samples were injection molded at 200°C. The following properties were obtained. The above data indicate that the blend of this example is an elastomeric thermoplastic.

Using standard techniques, samples were primed with a primer (Siebert OxidermO) and coated with a flexible polyurethane enamel (Durethane 100).
) and overcoated white and blue.

The samples were then examined for paint adhesion, paint adhesion after water impregnation, and paint adhesion after salt water impregnation and heat treatment.
There were no cases where adhesion was insufficient. Furthermore, as a result of exposure to a weatherometer, there was no change in the painted surface attributable to the substrate. Example 10 The weight composition of the blend is polypropylene 28.8, HAF
The same ingredients and procedure as in Example 9 were used, except that -LS carbon black was 28.8, ethylene propylene terpolymer was 30.7, and process oil was 12.3.

The following physical properties were obtained. These results indicate that the sample is a thermoplastic elastomer. Samples were painted as in Example 9 and similar results were obtained for adhesion and weatherometer tests. Scanning electron micrographs showed that the crystalline polyolefin phase was free of carbon black.

Example 11 Polypropylene was mixed with 15% by weight process oil in a Banbury unit as in Example 1.

Claims (1)

[Claims] 1(a) A copolymer of ethylene and at least one other C_3 to C_1_0 higher α-olefin, or ethylene and at least one other C_3 to C_1_
(b) about 15 to 70 parts by weight of a crystalline polyolefin from C_2 to C_8, and (c) naphthene. An elastomeric thermoplastic comprising from about 5 to 100 parts per 100 parts of copolymer and/or terpolymer of a hydrocarbon oil selected from the group consisting of oils of the copolymer and/or terpolymer type. 2. The thermoplastic material according to claim 1, wherein the higher α-olefin is propylene. 3. The thermoplastic material according to claim 1 or 2, wherein the non-conjugated diolefin is 5-ethylidene-2-norbornene. 4. The thermoplastic material according to any one of claims 1 to 3, wherein the crystalline polyolefin is polypropylene. 5. About 10 to 120 parts of highly reinforcing carbon black per 100 parts of copolymer and/or terpolymer.
The elastomeric thermoplastic material according to any one of claims 1 to 4, comprising: 6. The thermoplastic material according to claim 5, wherein the carbon black is a low-structure carbon black. 7. The thermoplastic according to claim 5 or 6, wherein the ethylene copolymer or terpolymer has a number average molecular weight of about 120,000 to 160,000. 8. The thermoplastic material according to any one of claims 1 to 7, wherein the thermoplastic material has an average distance of 1 μm.
A thermoplastic consisting of two continuous phases separated from each other by