WO2018206099A1

WO2018206099A1 - A household appliance component made of a glossy material and a process for producing a household appliance component

Info

Publication number: WO2018206099A1
Application number: PCT/EP2017/061165
Authority: WO
Inventors: Orkun KAYMAKCI; Ceren YARGICI
Original assignee: Arcelik Anonim Sirketi
Priority date: 2017-05-10
Filing date: 2017-05-10
Publication date: 2018-11-15
Also published as: TR201805760A2

Abstract

A household appliance component made of a polypropylene based polymeric material having high gloss properties. It is an object of the present invention also a process for producing the above mentioned household appliance component.

Description

A HOUSEHOLD APPLIANCE COMPONENT MADE OF A GLOSSY MATERIAL AND A PROCESS FOR PRODUCING A HOUSEHOLD APPLIANCE COMPONENT

The present invention relates to a household appliance component made of a highly glossy material and to a process for producing such household appliance component. More in detail the present invention refers in particular to a household appliance component made of a polypropylene based polymeric material capable of defining smooth surfaces exhibiting a high light reflectance.

In the state of the art glossy materials are generally used to realize various components of household appliances and in particular components that are visible and that therefore require an appealing appearance and/or components that are aimed to be touched by the user and that therefore require a pleasant surface texture.

Currently such components are generally made of polymeric materials such as acrylonitrile butadiene styrene (ABS), polycarbonate-acrylonitrile butadiene styrene (PC-ABS) or High Impact Polystyrene (HIPS), which combine the desired aesthetic and tactile characteristics with adequate mechanical properties. However, the costs of these materials are significantly higher than the costs of other polymeric materials generally used for manufacturing components of household appliances that do not require peculiar aesthetic and tactile characteristics, such as for instance polypropylene.

The Chinese patent application n. CN102617929 discloses a high gloss modified polypropylene resin suitable to be used for the realization of household appliances components and a method for producing it. The high gloss polypropylene resin comprises, beside polypropylene as a main constituent, the following further constituents: barium sulfate, glass fiber, compatibilizer, toughening agent, nucleating agent, lubricant, weathering agent and antioxidant. The method for producing it comprises the steps of weighing each costituent so as to obtain the desired weight percentages, mixing them in a high mixing machine, placing the obtained mixed components in a hopper of a twin-screw extruder, melting, extruding and granulating the mixture.

An objective of the present invention is to provide a household appliance component made of a glossy material which has an appealing appearance and/or a pleasant surface texture and at the same time adequate mechanical, optical, chemical and physical properties, while requiring a lower production cost with respect to the household appliance components made of the materials currently available on the market to be used for the same purposes.

A further objective of the present invention is to provide a process for producing a household appliance component made of such glossy material which is easy to be executed, cost effective and providing reliable results.

The household appliance component designed to fulfill the object of the present invention, explicated in the first claim and the respective claims thereof, is made of a polypropylene based polymeric material comprising graphene oxide, and preferably a multilayer graphene oxide, which confers to the base material particularly high gloss properties.

In an embodiment, the graphene oxide is present in the polypropylene based polymeric material in a percentage by weight between 0,1% and 10% and preferably between 0,5% and 3% and, more advantageously, between 0,5% and 1%.

The process object of the present invention comprises introducing a dosed amount of graphene oxide in powder form in a selected first amount of a solvent capable of dissolving polypropylene, as for instance xylene, subjecting the first amount of solvent with the graphene oxide to ultrasonic vibration for dispersing the graphene oxide in the solvent, introducing a dosed amount of polypropylene in a selected second amount of the solvent, mixing the first amount of solvent containing the graphene oxide and the second amount of solvent containing polypropylene, obtaining a mixture, evaporating the solvent from the mixture for obtaining a batch of composite material, grinding the composite material for obtaining particles of it, and finally forming the household appliance component starting from the particles of composite material, according to the formation technics traditionally used for this purposes, as for instance injection molding technic.

In a form of realization of the process, by evaporating the solvent from the mixture a masterbatch of composite material containing a higher concentration, for instance around 20% by weight, of graphene oxide than the final desired concentration is obtained and the process further comprises mixing the particles of composite material with a measured amount of particles of polypropylene for obtaining a final batch of composite material having the desired concentration of graphene oxide.

In a further form of realization of the process, the step of mixing the particles of composite material with a measured amount of particles of polypropylene is performed by means of an extruder.

In another form of realization of the process, the second amount of solvent in which the dosed amount of polypropylene is introduced is heated and, in a further version of this form of realization, the first amount of solvent containing the graphene oxide is heated before being mixed with the second amount of solvent containing the dosed amount of polypropylene.

DETAILED DESCRIPTION:

The household appliance component of the present invention is made of a glossy material which is a polypropylene based polymeric material comprising graphene oxide.

It has been in fact verified that, surprisingly, by adding graphene oxide to a polypropylene based polymeric material as the one generally used for the realization of household appliance components, the gloss properties of the final material are significantly increased.

For instance the gloss value of a household appliance component according to the invention, i.e. made of a polypropylene based polymeric material comprising graphene oxide, measured by means of a glossmeter at a specular angle of 60° is greater than 80 GU, reaching values even of 90 GU, while the gloss value of the same polypropylene based polymeric material without the addition of graphene oxide is generally around 70 GU.

Therefore the household appliance components according to the present invention present gloss properties that are comparable to the gloss properties of the household appliance components made of high-glossy materials that are generally used in the same technical field, like for instance HIPS, ABS or PC-ABS as above specified, while ensuring lower production costs and in particular production costs that are comparable with the production costs of the same components made of a polypropylene based polymeric material.

Moreover since the gloss properties pertain to the bulk material and are not derived from a surface treatment of the household appliance component, even upon usage of the component the gloss properties of the latter remain optimal.

With the expression polypropylene based polymeric material it is intended to indicate a polymeric material in which polypropylene is the main constituent, with the possible addition of one or more of other polymers, such as for instance polyethylene for obtaining a polypropylene/polyethylene blend, or with the possible addition of one or more additives, as the ones that are generally introduced in the polypropylene based formulations used for the realization of household appliance components for achieving for instance the desired processability or the desired mechanical, chemical, optical or physical features of the final component.

According to an embodiment of the present invention, the graphene oxide is present in the polypropylene based polymeric material in a percentage by weight between 0,1% and 10% and, preferably, between 0,5% and 3%. It has in fact been verified that the addition of graphene oxide in an amount included in the above specified ranges is sufficient to ensure the desired enhanced gloss properties to the polypropylene based polymeric material, without however significantly altering the remaining properties of such polymeric material. In this manner the desired properties of the final household appliance component, such as for instance durability, corrosion resistance, shocks absorbing capability, impact resistance, resistance to thermal shock or other mechanical and/or chemical properties that are desired on the final household appliance component and for which the polypropylene based polymeric material is designed, are ensured also on the household appliance component made of polypropylene based polymeric material containing graphene oxide in the above mentioned amounts.

In another embodiment, the graphene oxide is a multilayer graphene oxide. It has in fact been verified that the multilayer graphene oxide better contribute to enhancing the gloss properties of the polypropylene based polymeric material with respect to the monolayer graphene oxide, conferring a higher light reflectance to the surfaces of the final household appliance component.

It is an object of the present invention also a process for producing a household appliance component as above specified. The process according to the invention comprises, upon measuring a desired amount of graphene oxide in powder form and a selected first amount of solvent capable of dissolving polypropylene, introducing the dosed amount of graphene oxide in powder form in the selected first amount of solvent.

In a form of realization of the process, the solvent is for instance xylene, which is suitable for dissolving polypropylene.

The process hence comprises subjecting the first amount of solvent containing the graphene oxide to ultrasonic vibration for dispersing the graphene oxide in the solvent obtaining a first amount of solvent with the graphene oxide thoroughly dispersed in it.

The process comprises, upon measuring a desired amount of polypropylene and a selected second amount of solvent, introducing the dosed amount of polypropylene in the selected second amount of the solvent. Preferably, the second amount of solvent in which the dosed amount of polypropylene is introduced is heated in order to favor the polypropylene to be melted and dissolved in the solvent. In particular the solvent is heated at a temperature higher than the room temperature (20°C) and lower than the boiling temperature of the solvent, in order to avoid the evaporation of the solvent. For instance, in the case where the solvent is xylene, as above specified, having a boiling point of 138°C, the solvent could be heated at a temperature between 120°C and 130°C.

The process according to the invention further comprises mixing the first amount of solvent containing the graphene oxide and the second amount of solvent containing polypropylene, obtaining a mixture.

According to a form of realization of the process, the first amount of solvent containing the graphene oxide is also heated before being mixed with the second amount of solvent containing the dosed amount of polypropylene. In particular the first amount of solvent containing the graphene oxide is heated till the same temperature as the temperature of the heated second amount of solvent containing polypropylene, in order not to reduce the overall temperature of the mixture and to avoid disturbing the melting and dissolution of polypropylene in the solvent.

The process further comprises evaporating the solvent from the mixture for obtaining a batch of composite material, that is a batch of polypropylene (i.e. polypropylene based polymeric material) containing graphene oxide, advantageously after pouring the mixture on a container, such as for instanced a tray, in order to increase the evaporating surface and speed up the evaporation of the solvent. In a preferred form of realization of the process the mixture is maintained at a temperature higher than the room temperature in order to shorten the time required for the solvent to be completely evaporated.

Once the solvent is evaporated, the process envisages grinding the composite material for obtaining particles of it. Finally the selected household appliance component is formed starting from the particles of composite material.

Thanks to the process according to the present invention and, in particular, thanks to the steps of mixing together a first amount of solvent containing the graphene oxide and a second amount of solvent containing the dissolved propylene or propylene based polymer material, the graphene oxide particles are covered with polypropylene, preventing them from agglomerate and ensuring that the surface area of the graphene oxide particles is maximized in the polypropylene composite and, hence, the gloss properties of the composite material are enhanced.

In a form of realization of the process, the content of graphene oxide in the mixture of the first amount of solvent containing the graphene oxide and the second amount of solvent containing polypropylene, is higher than the desired content of graphene oxide in the final composite material. In this case, by evaporating the solvent from the mixture, a masterbatch of composite material containing a higher concentration of graphene oxide than the final desired concentration is obtained and the process further comprises mixing the particles of composite material with a measured amount of particles of polypropylene, or of polypropylene base polymer material, for obtaining a final batch of composite material having the desired concentration of graphene oxide. In this manner it is easier to effectively homogeneously disperse the graphene oxide within the mass of polypropylene.

Should other polymers or additives be included in the formulation of the polypropylene based polymeric material, they are added to the polypropylene before introducing the latter in the second amount of solvent and/or they are added together with the measured amount of particles of polypropylene during mixing such particles with the particles of composite material.

In a version of this form of realization of the process, the concentration of graphene oxide in the masterbatch of composite material is around 20% by weight. By subsequently mixing the concentrated composite material with a further selected amount of polypropylene (or polypropylene base polymer material), the concentration of graphene oxide in the final composite material is lowered to the desired values, as above specified.

According to a form of realization of the process, the step of mixing the particles of composite material with a measured amount of particles of polypropylene is performed by means of an extruder. The masterbatch of composite material containing a higher concentration of graphene oxide and polypropylene (or polypropylene base polymer material) particles are introduced in an extruder, such in particular a double-screw extruder, to prepare a polypropylene based composite material having a lower graphene oxide content.

Therefore the process according to the present invention allows to obtain a household appliance component having high gloss properties and therefore an appealing appearance and a pleasant surface texture, while requiring lower production costs with respect to the household appliance components made of other materials traditionally used for the same purpose, as for instance acrylonitrile butadiene styrene (ABS), polycarbonate-acrylonitrile butadiene styrene (PC-ABS) or High Impact Polystyrene (HIPS).

Claims

A household appliance component made of a glossy material, characterized in that the glossy material is a polypropylene based polymeric material comprising graphene oxide.
A household appliance component made of a glossy material as in Claim 1, characterized in that the graphene oxide is present in the polypropylene based polymeric material in a percentage by weight between 0,1% and 10%.
A household appliance component made of a glossy material as in Claim 2, characterized in that the graphene oxide is present in the polypropylene based polymeric material in a percentage by weight between 0,5% and 3%.
A household appliance component made of a glossy material as in any of the preceding claims, characterized in that the graphene oxide is a multilayer graphene oxide.
A process for producing a household appliance component according to any of the above claims, comprising:

- introducing a dosed amount of graphene oxide in powder form in a selected first amount of a solvent capable of dissolving polypropylene;

- subjecting the first amount of solvent containing the graphene oxide to ultrasonic vibration for dispersing the graphene oxide in the solvent;

- introducing a dosed amount of polypropylene in a selected second amount of the solvent;

- mixing the first amount of solvent containing the graphene oxide and the second amount of solvent containing polypropylene, obtaining a mixture;

- evaporating the solvent from the mixture for obtaining a batch of composite material;

- grinding the composite material for obtaining particles of it;

- forming the household appliance component starting from the particles of composite material.
A process for producing a household appliance component as in claim 5, characterized in that by evaporating the solvent from the mixture a masterbatch of composite material containing a higher concentration of graphene oxide than the final desired concentration is obtained and the process further comprises mixing the particles of composite material with a measured amount of particles of polypropylene for obtaining a final batch of composite material having the desired concentration of graphene oxide.
A process for producing a household appliance component as in claim 6, characterized in that the concentration of graphene oxide in the masterbatch of composite material is around 20%.
A process for producing a household appliance component as in claim 6 or 7, characterized in that the step of mixing the particles of composite material with a measured amount of particles of polypropylene is performed by means of an extruder.
A process for producing a household appliance component as in any of the claims 6 to 8, characterized in that the second amount of solvent in which the dosed amount of polypropylene is introduced is heated.
A process for producing a household appliance component as in claim 9, characterized in that the first amount of solvent containing the graphene oxide is heated before being mixed with the second amount of solvent containing the dosed amount of polypropylene.
A process for producing a household appliance component as in any of the claims 6 to 10, characterized in that the solvent is xylene.