|Title of Invention
"PIGMENT PREPARATION FOR DYING POLYMERS"
|The present invention relates to pigment preparation for dyeing polymers including one or more pigments and a carrier characterized by the fact that the pigment preparation is a chemical compound of between 50% and 90% pigment and between 10 and 50% of the carrier; wherein the carrier includes:- An oligomer, a polymer or a combination of both from the following group: Ethylene acrylic acid wax, or polycaprolactone; and One or more of the following polymer: Acrylic acid methyl ester, Ethylene/acrylate butyl polymer, Ethylene/methacrylate acid polymer, Polypropylene grafted with methyl polymethacrylate (PMMA-grafted PP), Polypropylene with grafted polystyrene (PS-grafted PP) or copolymers in a styrene block.
"PIGMENT PREPARATION FOR DYING POLYMERS"
This includes one or more pigment mixtures and a carrier. The carrier has an oligomer or a combination of low molecular weight polymers from the group including Ethylene acrylic acid polymers and copolymers, Ethylene maleic anhydride polymers and copolymers or Anhydride maleic polypropylene polymers and copolymers. The carrier also has a polymer from the group including Ethylene acrylic ethyl, Ethylene/acrylate butyl, Ethylene/methacrylate acid, polypropylene grafted with methyl polymethacrylate, Polypropylene with grafted polystyrene or copolymers in a styrene block. For organic pigments, the preparation is between 50%-70% pigment and 50-30% carrier. For inorganic pigments it is between 60-90% pigment and 40-10% carrier.
A multipurpose pigment preparation is obtained which can be used to manufacture highly accurate colour concentrates with specific bases.
This invention refers to a pigment preparation used as an intermediary product for dying polymers, the advantages of which has numerous benefits, as detailed in this report.
The invention belongs to the technical area of plastics, in particular dying polymers.
Colour concentrates are normally used to dye polymers, called "masterbatch" in the technique. The advantages of using colour concentrates, with regard to other systems, such as dry dying, are described below.
The process of polymer dry dying is carried out by simply physically mixing pigments with the polymer. The pigment powder particles have a strong tendency to group together and to form strongly cohesive clumps. These are difficult to separate using a transformation process. In consequence it is normal that the dyed material has spots and colour stains. This process cannot be used on thin materials (film, raffia, fibre, laminate...) or where how the material looks is critical.
In the case of colour concentrates, there are pigment dispersions in the form of very fine particles which are included into a plastic medium similar to the resin to be dyed or a medium which is compatible to the same. Highly uniform and high-quality dyes are obtained due to the optimum dispersion of the pigment.
Typical colour concentrates are in the form of granules and the conventional concentration is between 5-30% for organic pigments and 15 - 60% for inorganic pigments. Usage dosage is between 2-4% depending on the transformation system for the resin to be dyed as well as the thickness of the final article. In general, colour concentrates are used in processes which require a prior mixture of the material to be dyed in a spindle such as during the injection,
extrusion, extrusion-blowing etc moulding processes.
Color concentrate production can be carried out using different methods:
1 -From a powder pigment: production is in two
stages. During the first phase the pigments, spreaders,
lubricants, stabilisers and other additives are mixed with
the resin, usually in turbo mixers or by using a gravimetric
analysis. During the second stage the finished product is
obtained by excluding the pre-mixture using a twin spindle
co- rotating extruder.
2 -Using single colour concentrates: in this case
single pigment colour concentrates are obtained using the
method described in the above section during the first
phase. The final colour concentrate is obtained by
extruding the physical mixture with the support polymer
(normally using a single spindle extruder). The pigment
concentration of the single colours is usually between 15-40% for organic pigments and between 40-70% for inorganic pigments. These single colour concentrates are compatible with a very limited family of polymers.
3 -Using pigment preparations: the pigment
preparations have an optimum dispersion of a pigment in an
organic medium. The concentration is typically 40-50% for
organic pigments and 50-80% for inorganic pigments. The
drawback for single colour concentrates is that they have a
limited compatibility. In practice, the use of pigment
preparations is limited to polyolefinic polymers, some
elastomers and with restrictions in polyamide. The final
colour concentrate is usually obtained by extruding a
physical mixture of the pigment preparations and the support
polymer in a co-rotating dual spindle extruder. As opposed
to single colour concentrates, pigment preparations are
physically micro-granules which are obtained from the
pigments in the form of a pressed filter aqueous paste.. This paste is placed in a vacuum mixer. Small amounts of special additives are added to quickly remove water and moisture from the pigment particles by using the organic substrate (oils, waxes, plasticisers, polymers, etc).
If there are universal colour concentrates, which are theoretically compatible with all polymers, their use in practice is restricted to the type of application.
For dying critical articles or during critical applications, the use of specific colour concentrates is required together with the same or chemically very similar support as the resin to be coloured.
It is necessary to find the optimum combination of spreaders, stabilisers, lubricants, etc for each support during the manufacture of colour concentrates with specific bases. This means that the manufacturer of colour concentrates or dying compounds (particularly for technical polymers) must use many formulas and manufacturing processes.
It would be much easier if there were multipurpose pigment preparations which could be used to manufacture colour concentrates with specific and highly accurate bases. The invention proposes multipurpose pigment preparations which, when mixed with any polymer resin and by using an extrusion process (twin spindle co-rotating extruder), allows colour concentrates with specific bases to be obtained.
The pigment preparations in this invention are obtained using a two-stage process: premixing and simple extrusion resulting in 3 mm granules or preferably micro-granules with a diameter of less than 1.2 mm.
More specifically, the single pigment colour concentrates in the invention have the following chemical
50-70% pigment 50-30% carrier
Inorganic pigments: 60-90% pigment 40-10% carrier
The carrier has an oligomer, a polymer or a combination of both from the following group: Ethylene acrylic acid; Ethylene maleic anhydride; Anhydride maleic polypropylene; Polycaprolactone; Their mixtures or combinations.
And preferably one or more of the following polymers:
Ethylene acrylic acid polymer Ethylene/acrylate butyl polymer Ethylene/methacrylate acid polymer Polypropylene grafted with methyl polymethacrylate (PMMA-grafted PP) Polypropylene with grafted polystyrene (PS-grafted PP) ;
Copolymers in a styrene block Their mixtures, combinations or copolymers
The use of the aforementioned pigment preparations considerably simplifies the colour concentrate production process. In order to obtain the pigment preparations just the physical mixing of different pigments with the base polymer is required followed by processing in a twin spindle co-rotating extruder. The premixing process in a turbo mixer is not required using this process and therefore the
complexity of studying and selecting from a recipe of spreaders, stabilisers, lubricants, etc for each polymer is avoided.
By using the invention, it is also possible to simplify the colour equaling process. Premixing pigments, additives, etc is also not required during the production process and the development process of a new colour. In this way, the colour duplication process is simpler and quicker.
Another advantage of the invention is that the same intermediate products are used, due to the preparation phase in the laboratory and the production phase in the factory. The change of scale between laboratory and reduction is thereby avoided.
The high concentration of pigments in the invention allows costs to be -reduced and flexibility in simplifying the production process to be increased. Also the product in the invention is a multipurpose product meaning that it can be used for all polymers (LDPE, LLDPE, HDPE, PP -homo and copolymer -, PVC -rigid and plasticised-, PS, ABS, ASA, SAN, CAB, PA, PC, PET, PBT, etc) .
In this way, the carrier is also multipurpose and is compatible with the majority of commercial polymers with the ability to be mixed with itself or with any other polymer in any proportion with a carrier in order to obtain a highly accurate, specific colour concentrate.
Having sufficiently described how this invention, it is easy understood that any modification to the detail of the mention which is judged to be suitable may be made whenever the essential features of the summarised invention in the following claims are not altered.
1. Pigment preparation for dyeing polymers including one or more pigments and a carrier
characterized by the fact that the pigment preparation is a chemical compound of between
50% and 90% pigment and between 10 and 50% of the carrier; wherein the carrier
a) An oligomer, a polymer or a combination of both from the following group: Ethylene acrylic acid wax, or polycaprolactone; and
b) One or more of the following polymer: Acrylic acid methyl ester, Ethylene/acrylate butyl polymer, Ethylene/methacrylate acid polymer, Polypropylene grafted with methyl polymethacrylate (PMMA-grafted PP), Polypropylene with grafted polystyrene (PS-grafted PP) or copolymers in a styrene block.
2. Pigment preparation as claimed in claim one, wherein the said pigment is an organic pigment with a chemical composition of between 50 and 70% of the aforementioned pigment and between 50 and 30% of the aforementioned carrier.
3. Pigment preparation as claimed in claim one, wherein the aforementioned pigment is an inorganic compound with a chemical composition of between 60 and 90% of the aforementioned pigment and between 40 and 10% of the aforementioned carrier.
4. Pigment preparation as claimed in claim one, wherein the said pigment fraction has organic and/or inorganic pigments with a chemical composition of between 50 and 90% pigment mixture and between 50 and 10% of the aforementioned carrier.
|Indian Patent Application Number
|PG Journal Number
|Date of Filing
|Name of Patentee
|IQAP COLORPOINT, S.A.
|CTRA. DE VIC A OLOT, KM 5, E-08510 MASIES DE RODA,SPAIN
|PCT International Classification Number
|PCT International Application Number
|PCT International Filing date