WO2024189596A1

WO2024189596A1 - Polypropylene composite composition

Info

Publication number: WO2024189596A1
Application number: PCT/IB2024/052543
Authority: WO
Inventors: Sairam T C N; Sharath PRASAD; Adithya BHARADWAJ; Anjan ROY
Original assignee: Reliance Industries Ltd
Current assignee: Reliance Industries Ltd
Priority date: 2023-03-15
Filing date: 2024-03-15
Publication date: 2024-09-19
Anticipated expiration: 2025-09-15

Abstract

The present disclosure relates to a polypropylene composite composition. The polypropylene composite composition comprises a mixture of polypropylene impact copolymers; and optionally, an additive. The present disclosure also relates an article or component produced by molding the polypropylene composite composition.

Description

POLYPROPYLENE COMPOSITE COMPOSITION

CROSS -REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Indian Patent Application No. 202321013871, filed March 15, 2023, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to a polypropylene composite composition, and more particularly to a polypropylene composite composition for telecom products/devices.

BACKGROUND

Existing telecom products/devices for fixed devices (such as set top boxes and home gateways wherein electronic devices are placed on table-top or mounted to the wall) have materials with higher strength and impact properties that are not required for the intended application. Also, existing materials such as PC (polycarbonate) or PC-ABS or PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene terpolymer) are relatively expensive, and difficult to process. Further, commodity plastic is unsuitable for electronic/telecom enclosures. In addition, some of the existing materials result in unacceptable dissipation factor values if used in telecom devices with antenna for signal transmission/reception.

Therefore, there is a need in the art to provide new materials/composites which may overcome the drawbacks of the prior art. Furthermore, it is imperative that any new materials or composites or composite composites to be introduced to the market maintain or surpass some or all essential properties required for their intended applications. These properties encompass a wide range of characteristics, including mechanical properties such as Tensile Strength at Yield, Elongation at Yield, Elongation at Break, Flexural Strength, Flexural Modulus, Izod Impact Strength (Notched), and HDT (Heat Deflection Temperature), as well as electrical properties such as volume resistivity, dielectric strength, and surface resistivity. Additionally, melt flow index (MFI) and shrinkage are important properties to consider.

SUMMARY

Accordingly, the disclosure herein provides a polypropylene composite composition.

In an aspect, the present disclosure provides a polypropylene composite composition comprising a mixture of polypropylene impact copolymers; and optionally, an additive.

In another aspect, the present disclosure provides a polypropylene composite composition comprising about 60% to about 90% by weight of a mixture of polypropylene impact copolymers; and remaining is optionally additive.

In a further aspect, the present disclosure provides a polypropylene composite composition having high elongation at yield and low MFI.

In yet another aspect, the present disclosure provides an article or component produced by molding the polypropylene composite composition as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present disclosure will become fully apparent from the following description taken in conjunction with the accompanying figures. With the understanding that the figures depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described further through use of the accompanying figures:

Figure 1 illustrates isobaric PVT measurement of the polypropylene composite composition of Example 1. Figure 2 illustrates DSC Thermogram (heat flow as a function of temperature) of the polypropylene composite composition of Example 1.

Figure 3 illustrates DSC Thermogram (specific heat capacity as a function of temperature) the polypropylene composite composition of Example 1.

Figure 4 illustrates housings made with polypropylene pellets in accordance with an embodiment.

DETAILED DESCRIPTION

Before the present disclosure is described in greater detail, it is to be understood that the disclosure is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the present disclosure.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the methods. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the methods, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the methods.

Certain ranges are presented herein with numerical values being preceded by the term “about.” The term “about” is used herein to provide literal support for the exact number that it precedes, as well as a number that is near to or approximately the number that the term precedes. In determining whether a number is near to or approximately a specifically recited number, the near or approximating unrecited number may be a number which, in the context in which it is presented, provides the substantial equivalent of the specifically recited number. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, preferred methods and materials are described. For the purposes of the present disclosure, the following terms are defined below.

The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

As used herein, the term "comprises" or "comprising" is generally used in the sense of include, that is to say permitting the presence of one or more features or components.

In an embodiment, the present disclosure provides a polypropylene composite composition.

In certain embodiments, the present disclosure provides a polypropylene composite composition satisfying the following property requirements: tensile strength of more than about 15 Mpa; flexural modulus of more than about 1500; flexural strength of more than about 25 Mpa; Izod impact (notch) of more than about 200 J/m; dielectric constant of about 2 to about 3 at 5 Hz; dielectric strength of more than about 21.2 kV/mm; heat distortion temperature (HDT) of more than about 90 °C; and flammability (horizontal-burning, HB); and/or color (AE < 1) of Pantone 533C.

In certain embodiments, the polypropylene composite composition comprises a mixture of polypropylene impact copolymers; and optionally, an additive. In further embodiments, the polypropylene composite composition comprises a mixture of polypropylene impact copolymers; a polypropylene homopolymer (PPHP); and optionally, one or more additives. The PPHP may present in from about 5% to about 24% by weight, about 5% to 15% by weight, or about 10% to about 25% by weight. Any PPHP known in the art may be used. The term "homopolymer" refers to a polymer comprising repeating units originating from a single type of monomer. However, it does not preclude the presence of residual quantities of other substances utilized in the production process of the homopolymer. In some embodiments, the PPHP is Repol Hl 10MA.

Polypropylene impact copolymers as used herein refer to impact copolymers which contain a propylene homopolymer containing a co-mixed propylene random copolymer phase which has an ethylene content of about 5-30%.

In certain embodiments, the polypropylene composite composition comprises about 60% to about 90% by weight of a mixture of polypropylene impact copolymers; and remaining is optionally additive.

In certain embodiments, the mixture of polypropylene impact copolymers comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; and about 20% to about 70% by weight of a second polypropylene impact copolymer; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer. In certain embodiments, the mixture comprises about 20% to about 50%, about 25% to about 50%, or about 30% to about 50% by weight of a first polypropylene impact copolymer; and about 25% to about 70%, about 30% to about 70%, about 25% to about 65%, about 25% to about 60%; or about 25% to about 55% by weight of a second polypropylene impact copolymer; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer.

In certain embodiments, the first polypropylene impact copolymer has medium impact strength. In some embodiments, the first polypropylene impact copolymer has medium impact strength of about 150 J/m. Any polypropylene impact copolymer having medium impact strength may be used as the first polypropylene impact copolymer. The first polypropylene impact copolymer may be prepared to satisfy the said-mentioned property requirements using a conventional method known in the art or may be commercially obtained and used. In an exemplary embodiment, Repol C320MN, Repol B650MN, Repol B300MN, and/or Repol D120MA is used as the first polypropylene impact copolymer. To impart high impact strength and higher melt flow, a second polypropylene impact copolymer is added to the composition. Thus, in certain embodiments, the second polypropylene impact copolymer is high crystalline impact copolymer polypropylene. The second polypropylene impact copolymer may be prepared to satisfy the said-mentioned property requirements using a conventional method known in the art or may be commercially obtained and used. In some embodiments, Repol HCPP B300MN is used as the second polypropylene impact copolymer. In an exemplary embodiment, Repol C080MA is used as high impact copolymer polypropylene.

In certain embodiments, the polypropylene in the composition may be a recycled polypropylene. The term “recycled polypropylene” refers to a polypropylene polymer that has been previously utilized and then recycled again. In some embodiments, the recycled polypropylene is post-consumer recycled polypropylene (PCR-PP). The PCR-PP has advantageous in some cases, including: (i) a 20-30% reduction in carbon footprint compared to producing virgin PP; (ii) energy savings of up to 3.5 kWh per pound of recycled PP versus producing new PP; (iii) about 30% decrease in plastic waste sent to landfills; and (iv) about 5% reduction in material costs.

The polypropylene composite composition may further comprise an additive. The additive is selected from a group comprising a stiffener, a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

In certain embodiments, the polypropylene composite composition may comprise a stiffener. The stiffener may present in about 10% to about 30% by weight. In certain embodiments, the stiffener may present in about 10% to about 25% by weight or about 15% to about 25% by weight, or about 10% to about 20% by weight. In some instances, the stiffener may present in about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, or about 30% by weight. Any stiffener known in the art may be used. Examples of stiffener include, but are not limited to, talc (such as micro talc and soapstone, etc.), calcium carbonate, glass and combinations thereof.

In certain embodiments, the polypropylene composite composition may comprise a modifier. The modifier may present in about 1% to about 10% by weight. In certain embodiments, the modifier may present in about 1% to about 8% by weight, or about 2% to about 10% by weight, or about 1% to about 5% by weight, or about 5% to about 10% by weight. In some instances, the modifier may present in about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10% by weight. Any modifier known in the art may be used. Examples of modifier include, but are not limited to, process, optical, tensile, flammability and combinations thereof. In certain embodiments, the modifier is a polyolefin elastomer. Non-limiting examples of polyolefin elastomer include, but are not limited to, ethylene-octene (EO) polyolefin elastomer (POE) and the like.

In certain embodiments, the polypropylene composite composition may comprise a colorant. The colorant may present in about 1% to about 8% by weight, or about 1% to about 7% by weight, or about 2% to about 8% by weight, or about 1% to about 6% by weight, or about 2% to about 8% by weight. In some instances, the colorant may present in about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, or about 8% by weight. Any colorant known in the art may be used. Examples of colorant include, but are not limited to, organic pigments, inorganic pigments and combinations thereof. Any pigment known in the art or commercially available may be used.

In certain embodiments, the polypropylene composite composition may comprise a scratch resistance agent. The scratch resistance agent may present in about 0.1 % to about 2% by weight, or 0.1% to about 1.5% by weight. In some instances, the scratch resistance agent may present in about 0.1%, about 0.15%, about 0.2%, about 0.25%, about 0.3%, about 0.35%, about 0.4%, about 0.45%, about 0.5%, about 0.55%, about 0.6%, about 0.65%, about 0.7%, about 0.75%, about 0.8%, about 0.85%, about 0.9%, about 0.95%, about 1%, about 1.05%, about 1.1%, about 1.15%, about 1.2%, about 1.25%, about 1.3%, about 1.35%, about 1.4%, about 1.45%, about 1.5%, about 1.55%, about 1.6%, about 1.65%, 1.7%, about 1.75%, about 1.8%, about 1.85%, about 1.9%, or about 2% by weight. Any scratch resistance agent known in the art may be used. Examples of scratch resistance agent include, but are not limited to, bio-based fatty acid or silicone or mica based and combinations thereof. In some embodiments, the scratch resistance agent is an organosilicone or oleochemical. Any organosilicone known in the art or commercially available may be used.

In certain embodiments, the polypropylene composite composition may comprise a UV resistance agent. The UV resistance agent may present in about 0.001% to about 3% by weight, or about 0.001% to about 2% by weight, or about 0.01% to about 3% by weight. In some instances, the UV resistance agent may present in about 0.001%, about 0.001%, about 0.002%, about 0.003%, about 0.004%, about 0.005%, about 0.006%, about 0.007%, about 0.008%, about 0.009%, about 0.01%, about 0.02%, about 0.03%, about 0.04%, about 0.05%, about 0.06%, about 0.07%, about 0.08%, about 0.09%, about 0.1%, about 0.15%, about 0.2%, about 0.25%, about 0.3%, about 0.35%, about 0.4%, about 0.45%, about 0.5%, about 0.55%, about 0.6%, about 0.65%, about 0.7%, about 0.75%, about 0.8%, about 0.85%, about 0.9%, about 0.95%, about 1%, about 1.05%, about 1.1%, about 1.15%, about 1.2%, about 1.25%, about 1.3%, about 1.35%, about 1.4%, about 1.45%, about 1.5%, about 1.55%, about 1.6%, about 1.65%, 1.7%, about 1.75%, about 1.8%, about 1.85%, about 1.9%, about 2%, about 2.05%, about 2.1%, about 2.15%, about 2.2%, about 2.25%, about 2.3%, about 2.35%, about 2.4%, about 2.45%, about 2.5%, about 2.55%, about 2.6%, about 2.65%, 2.7%, about 2.75%, about 2.8%, about 2.85%, about 2.9%, about 3%by weight. Any UV resistance agent known in the art may be used. Examples of UV resistance agent include, but are not limited to, silicone based, hindered amine type light stabilizers and combinations thereof. Any hindered amine type light stabilizer known in the art or commercially available may be used.

In certain embodiments, the polypropylene composite composition may comprise an antioxidant. The antioxidant may present in about 0.1% to about 3% by weight, or 0.1% to about 2.5% by weight, or 0.2% to about 3% by weight, or about 0.5% to about 3% by weight. In some instances, the antioxidant may present in about 0.1%, about 0.15%, about 0.2%, about 0.25%, about 0.3%, about 0.35%, about 0.4%, about 0.45%, about 0.5%, about 0.55%, about 0.6%, about 0.65%, about 0.7%, about 0.75%, about 0.8%, about 0.85%, about 0.9%, about 0.95%, about 1%, about 1.05%, about 1.1%, about 1.15%, about 1.2%, about 1.25%, about 1.3%, about 1.35%, about 1.4%, about 1.45%, about 1.5%, about 1.55%, about 1.6%, about 1.65%, 1.7%, about 1.75%, about 1.8%, about 1.85%, about 1.9%, about 2%, about 2.05%, about 2.1%, about 2.15%, about 2.2%, about 2.25%, about 2.3%, about 2.35%, about 2.4%, about 2.45%, about 2.5%, about 2.55%, about 2.6%, about 2.65%, 2.7%, about 2.75%, about 2.8%, about 2.85%, about 2.9%, about 3%by weight. Any antioxidant known in the art may be used. Examples of antioxidant include, but are not limited to, phenolic such as pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate and the like.

In certain embodiments, the polypropylene composite composition may comprise a lubricant. The lubricant may present in about 0.1% to about 2% by weight, or 0.1% to about 1.5% by weight. In some instances, the lubricant may present in about 0.1%, about 0.15%, about 0.2%, about 0.25%, about 0.3%, about 0.35%, about 0.4%, about 0.45%, about 0.5%, about 0.55%, about 0.6%, about 0.65%, about 0.7%, about 0.75%, about 0.8%, about 0.85%, about 0.9%, about 0.95%, about 1%, about 1.05%, about 1.1%, about 1.15%, about 1.2%, about 1.25%, about 1.3%, about 1.35%, about 1.4%, about 1.45%, about 1.5%, about 1.55%, about 1.6%, about 1.65%, 1.7%, about 1.75%, about 1.8%, about 1.85%, about 1.9%, or about 2% by weight. Any lubricant known in the art may be used. Examples of lubricant include, but are not limited to, calcium octadecanoate and the like.

In certain embodiments, the polypropylene composite composition may comprise a stiffener, a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, and a lubricant.

In certain embodiments, the polypropylene composite composition comprises about 60% to about 90% by weight of a mixture of polypropylene impact copolymers; and optionally, remaining is additive; wherein the additive is selected from a group comprising a stiffener, a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof. In certain embodiments, the polypropylene composite composition may further comprise PPHP. The PPHP may present in from about 5% to about 24% by weight, about 5% to 15% by weight, or about 10% to about 25% by weight. In some embodiments, the PPHP is same as defined above.

In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; and optionally, remaining is additive; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer; and the additive is selected from a group comprising a stiffener, a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof. In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; and about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight stiffener; and optionally, remaining is additive; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer; and the additive is selected from a group comprising a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; and optionally, remaining is additive; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer; and the additive is selected from a group comprising colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; about 1% to about 8% by weight of a colorant; and optionally, remaining is additive; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer; and the additive is selected from a group comprising a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; about 1% to about 8% by weight of a colorant; and remaining is additive; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer; and the additive is selected from a group comprising a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

In certain embodiments, the polypropylene composite composition comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; about 1% to about 8% by weight of a colorant; about 0.1 % to about 2% by weight of a scratch resistance agent; about 0.001% to about 3% by weight of a UV resistance agent; in about 0.1% to about 3% by weight of an antioxidant; and about 0.1 % to about 2% by weight of a lubricant; wherein the second polypropylene impact copolymer is different than the first polypropylene impact copolymer.

In certain embodiments, the polypropylene composite provided by the present disclosure has high elongation at yield and low MFI. In further embodiments, the polypropylene composite provided by the present disclosure has high elongation at yield and low MFI while maintaining low shrinkage and/or higher HDT (Heat deflection temperature). In some instances, the polypropylene composite provided by the present disclosure has high elongation at yield and low MFI while maintaining low shrinkage and higher HDT at 0.45MPa.In certain embodiments, the polypropylene composite composition provided by the present disclosure exhibits (i) mold flow index (MFI) of about 21.484 g/10 min; (ii) mold shrinkage of about 0.92 %, and/or (iii) dissipation factor value of about 2.75E-02 at 1 KHz.

The polypropylene composite composition provided herein can be molded into an article or component or part having no flow mark, waviness, and/or voids on the surface. In certain embodiments, the polypropylene composite composition provided herein is suitable for injection molding process to yield the articles or components. In some instances, the polypropylene composite composition is suitable for injection molding process yielding components with mold flow index (MFI) of 21.484 g/lOmin, mold shrinkage of 0.92% having no flow marks, voids, waviness, etc. In some instances, the article is an enclosure for an electronic, an electrical or a telecommunication device.

Thus, in certain embodiments, provided herein a molded article using the polypropylene composite composition provided herein and satisfying the above-described property requirements. In some instances, the molded article is an injection molded article.

The polypropylene composite composition provided herein is well placed between commodity and engineering plastic. Thus, the material is suited for applications for electronic/telecom enclosures which is not suitable with commodity plastic but at the same time not suitable for high-end/mobile/aesthetically superior devices.

In certain embodiments, the polypropylene composite composition provided herein has acceptable dissipation factor values which makes it suitable to be used for telecom devices with antenna for signal transmission/reception. In further embodiments, the polypropylene composite composition provided herein has HB (horizontal-burning) flammability rating as per UL-94 standards. Thus, it is suitable to be used for low DC voltage applications. Thus, in certain embodiments, the polypropylene composite composition provided herein is useful in making plastic housings/enclosures for electronic devices with low DC current carrying capacity.

In certain embodiments, the polypropylene composite composition provided herein is useful in making plastic housings or enclosures for house-hold appliances, loT devices automobiles, and the like. In certain embodiments, the polypropylene composite composition provided herein is of low cost compared to existing material used in fixed devices. For instance, the polypropylene composite composition provided herein costs 35-50% less than PC/PC-ABS or ABS material used in the fixed devices.

The present disclosure also provides a process for preparing a polypropylene composite composition satisfying the composition and content conditions as described above. In certain embodiments, the process for preparing the polypropylene composite composition may be prepared by compounding all the components such as polypropylenes and optionally additive(s) of the composition. The polypropylenes and the additive(s) are the same as described above.

Compounding is a process where all the components are mixed together in different quantities, melted, and blended to yield a composition. The compounding can be done in a compounding machine or device. Any compounding machine may be used in the process.

In certain embodiments, the polypropylene composite composition of the present disclosure is typically produced by compounding all the components in an extruder. All components, the polypropylenes and optionally the additive can be compounded together in an extruder.

In certain embodiments, the compounding is done in an extruder at a predetermined pressure and temperature. In some embodiments, the compounding is done at a temperature of about 200 °C to about 250 °C. In some embodiments, the compounding is done at a temperature of about 205 °C to about 220 °C. In some instances, the compounding is done at a temperature of about 205 °C, about 210 °C, about 215 °C, and/or about 220 °C.

In certain embodiments, the compounding pressure is about 550 to 650 mm/Hg or about 600 mm/Hg.

The present disclosure also provides a closure device such as an electronic or a telecom enclosure. The closure device comprises a polypropylene composite composition, The method of making a closure device according to the present disclosure comprises the steps of providing a polypropylene composite composition as disclosed in the present disclosure; and molding polypropylene composite composition to form the closure device.

The present disclosure is further described with reference to the following examples, which are only illustrative in nature and should not be construed to limit the scope of the present disclosure in any manner.

EXAMPLES

EXAMPLE 1: PREPARATION OF POLYPROPYLENE COMPOSITE COMPOSITION

A polypropylene composite composition was prepared. The details of the composition and process are depicted in Table 1 and Table 2, respectively.

Table 1: Composition

Table 2: Process Conditions

Table 1 contains details of composition for polypropylene composite compounding. During the compounding, the first polypropylene impact copolymer with 30-70% composition was mixed with second polypropylene impact copolymer (high crystalline impact copolymer) with 15-50%. The ratio between the first polypropylene impact copolymer and second polypropylene impact copolymer achieved right target values and balance stiffness and impact properties. The first polypropylene impact copolymer has medium impact strength. To impart high impact strength and higher melt flow, a second polypropylene impact copolymer was added to the composition. Along with this talc was added to the composition to increase stiffness of the end product. This increased the flexure modulus or bending resistance of the material to an applied load. Other property enhancers or additives were added in varying compositions as shown in table 1. These enhancers impart color, improve UV resistance, scratch, and other properties of the material.

The formulation of polypropylene composite was made into pellets, and these were tested for various properties such as rheological properties, thermal properties, physical properties, and electrical properties as shown below.

1. Rheological properties a) PVT isobaric:

During isobaric PVT measurements, the volume was determined at constant pressure as a function of temperature. The material was filled in at melting temperature and heated up to the starting temperature. Then a constant pressure was applied. Cooling was started and controlled to a constant cooling rate. During cooling, the volume was recorded as a function of the temperature. Afterwards, the system heats up again fully automatically and sets the next pressure level. In this way, any number of isobars at different pressures can be measured fully automatically with a single barrel filling. The isobaric measurement process was therefore similar to the actual production process in injection molding and the generated data was especially relevant for the simulation of injection molding processes. Knowledge of the shrinkage behavior is extremely important when designing molds. A PVT measurement also provides a precise description of the cooling process as it takes place in extrusion, for example. The data is shown in figure 1.

Test method: ISO 17744 - 2004 Sample Conditioning: 24 °C for 48 hrs

Measurement: Isobaric cooling @ 5°C / min. b) Melt flow rate:

It was measures by test method: ASTM D 1238 - 2013

c) Mold shrinkage:

It was measured by test method: ASTM D 955

d) Melting point:

• It was measured by test method: ASTM D 3418

• Specimen Preparation method: Injection Molding / Compression Molding

• Sample conditioning: 24 °C for 48 hrs

• Measurement Range: Ambient temperature to 300°C

• DSC Thermogram - Heat flow as a function of temperature is shown in figure 2

2. Thermal properties a. Specific heat capacity: It was measured by test method: ASTM E 1269. The result is shown in figure 3. b. Co-efficient of linear thermal expansion:

• Test method: ASTM D 228

• Specimen Preparation method: Injection Molding

• Sample conditioning: 24 °C for 48 hrs

• Specimen size: 80 mm x 10 mm x 3.2 mm

• Temperature range & difference (AT): 30°C to 90°C & AT = 60 °C

c. Thermal conductivity:

• Test method: ASTM E 1530 - 2016

• Specimen Preparation method: Injection Molding / Compression Molding

• Sample conditioning: 24 °C for 48 hrs

Physical properties a) Density:

Test method: ASTM D 792 • Specimen Preparation method: Injection Molding

• Sample conditioning: 24 °C for 48 hrs

• Test Temperature: 24°C, Relative Humidity (R.H.): 55%

b) Poisson’s ratio: 0.36 c) Other properties: The material was tested for tensile, Flexure and Impact properties. The values are depicted in Table 3 below.

Table 3

4. Electrical properties

Table 4: Electrical values

With a dissipation factor of 0.0275 @50Hz, the polypropylene housing was tested for RF performance and compared with existing housing using PC material. The results showed that there was no issue in antenna performance using polypropylene composite material.

EXAMPLE 2: TRANSFORMATION OF POLYPROPYLENE PELLETS INTO HOUSING

The transformation of polypropylene pellets into housing is shown in figure 4. No major difference observed in Wi-Fi RSSI & TPT performance of 2.4 GHZ and 5 GHZ with existing and new housing on 5 Nos sample trail.

EXAMPLE 3:

The following polypropylene composite compositions shown in Table 5 were prepared using the procedure depicted in Example 1 with appropriate variations in quantities of components in the composition.

Table 5

The composite compositions were further evaluated for material properties, and the results are summarized in Table 6.

Table 6

The properties of compositions of the present disclosure are compared with the marketed product PC-ABS and provided in table 7.

Table 7

Table 7 shows the comparison between PC-ABS material Vs PP. From comparing the results, it is apparent that the composition D (PP) of the present disclosure has low dielectric constant and low dissipation factor which helps to transmit antenna signals with significantly less attenuation. Additionally, the elongation at yield and break is higher for PP than PC-ABS, rendering the PP material more ductile. This property contributes to prevention of cracks in the device upon impact or dropping.

Composite Composition C has improved mechanical properties compared to Composite Composition A. The tensile strength has increased from 19.2 to 21.3 and the Izod impact strength has gone up from 292.35 to 337. This is crucial for its intended application. Additionally, the HDT (heat deflection temperature) has risen from 107.2 °C to 113°C, allowing the use of higher wattage components in electronic devices.

About 50 trials were conducted for PP and 75 trials were performed for color matching. Through the refinement of colorants over these trials, the color difference between the golden/reference sample of PP and the developed grade was maintained below 1 (AE<1).

Although the foregoing disclosure has been described in some detail by way of illustration and examples for purposes of clarity of understanding, it is readily apparent to those of ordinary skill in the art in light of the teachings of this disclosure that certain changes and modifications may be made thereto without departing from the spirit or scope of the present disclosure.

Accordingly, the preceding merely illustrates the principles of the disclosure. It will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventors to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of the present disclosure, therefore, is not intended to be limited to the exemplary embodiments shown and described herein.

Claims

WE CLAIM:

1. A polypropylene composite composition comprising a mixture of polypropylene impact copolymers; wherein the mixture comprises about 10% to about 50% by weight of a first polypropylene impact copolymer; and about 20% to about 70% by weight of a second polypropylene impact copolymer.

2. The polypropylene composite composition as claimed in claim 1, wherein the second polypropylene impact copolymer is different from the first polypropylene impact copolymer.

3. The polypropylene composite composition as claimed in claim 1 or 2, wherein the second polypropylene impact copolymer is high crystalline impact copolymer polypropylene.

4. The polypropylene composite composition as claimed in any of claims 1 to 3, further comprises a polypropylene homopolymer (PPHP).

5. The polypropylene composite composition as claimed in claim 4, wherein PPHP is present in from about 5% to about 24% by weight.

6. The polypropylene composite composition as claimed in any of claims 1 to 5, further comprises an additive selected from a group comprising a stiffener, a modifier, colorant, a scratch resistance agent, UV resistance agent, an antioxidant, a lubricant, and a combination thereof.

7. The polypropylene composite composition as claimed in claim 6, wherein the stiffener is present in about 10% to about 30% by weight.

8. The polypropylene composite composition as claimed in claim 6, wherein the modifier is present in about 1% to about 10% by weight.

9. The polypropylene composite composition as claimed in claim 6, wherein the colorant is present in about 1% to about 8% by weight.

10. The polypropylene composite composition as claimed in claim 6, wherein the scratch resistance agent is present in about 0.1 % to about 2% by weight.

11. The polypropylene composite composition as claimed in claim 6, wherein the UV resistance agent is present in about 0.001% to about 3% by weight.

12. The polypropylene composite composition as claimed in claim 6, wherein the antioxidant is present in about 0.1% to about 3.0% by weight.

13. The polypropylene composite composition as claimed in claim 6, wherein the lubricant is present in about 0.1% to about 2% by weight.

14. The polypropylene composite composition as claimed in any of claims 1 to 13, comprising about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; about 1% to about 8% by weight of a colorant; about 0.1% to about 2% by weight of a scratch resistance agent; about 0.001% to about 3% by weight of a UV resistance agent; in about 0.1% to about 3% by weight of an antioxidant; and about 0.1% to about 2% by weight of a lubricant.

15. The polypropylene composite composition as claimed in any of claims 1 to 14, comprising about 10% to about 50% by weight of a first polypropylene impact copolymer; about 20% to about 70% by weight of a second polypropylene impact copolymer; about 5% to about 24% by weight PPHP; about 10% to about 30% by weight of a stiffener; about 1% to about 10% by weight of modifier; about 1% to about 8% by weight of a colorant; about 0.1% to about 2% by weight of a scratch resistance agent; about 0.001% to about 3% by weight of a UV resistance agent; in about 0.1% to about 3% by weight of an antioxidant; and about 0.1% to about 2% by weight of a lubricant.

16. The polypropylene composite composition as claimed in any of claims 1 to 15, wherein the polypropylene composite composition exhibits (i) mold flow index (MFI) of 21.484 g/10 min, (ii) mold shrinkage of 0.92 %, and/or (iii) dissipation factor value of 2.75E-02 at 1 KHz.

17. An article comprising the polypropylene composite composition as claimed in any of claims 1 to 16.

18. The article as claimed in claim 17, wherein the article is an enclosure for an electronic, an electrical or a telecommunication device.

19. The article as claimed in claim 17 or 18, wherein the article has tensile strength of more than 15 Mpa; flexural modulus of more than about 1500; flexural strength of more than about 25 Mpa; Izod impact (notch) of more than about 200 J/m; dielectric constant of about 2 to about 3 at 5 Hz; dielectric strength of more than about 21.2 kV/mm; heat distortion temperature (HDT) of more than about 90 °C; and flammability (horizontal-burning, HB); and/or color (AE < 1) of Pantone 533C.