Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-03-23
2001-05-15
Sanders, Kriellion (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
Reexamination Certificate
active
06232378
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a process for incorporating an active substance in an object partly or entirely consisting of plastic, by bringing the object into contact with the active substance.
BACKGROUND OF THE INVENTION
Such a process is known from Kirk Othmer, Encyclopedia of Chemical Technology, Vol. 8 (1993), pp. 672-753. Described herein is the dying of plastic fibres in a bath containing a solution of a dye, in which the dye, in this case the active substance, penetrates the fibre.
A drawback of the known process is that the active substance is with difficulty absorbed into the plastic. It is for example not really possible to dye polypropylene fibres because the dye does not, or only with great difficulty, penetrates the polypropylene fibre.
The aim of the invention is to provide a process that does not possess the aforementioned drawback.
SUMMARY AND OBJECTS OF THE INVENTION
Surprisingly, it has now been found that the active substance is very well absorbed if the plastic of the object contains a dendrimer with terminal groups that are compatible with the plastic.
A further advantage is that new combinations of active substances and plastics have become possible, because active substances that are not absorbed into the plastic itself are absorbed into the plastic containing the dendrimer.
The invention creates new, surprising possibilities. It is for example possible for a highly effective active substance that cannot endure the processing of the plastic into the object—for example because the active substance degrades at the temperatures prevailing during the processing—to be incorporated in the plastic after the processing.
DETAILED DESCRIPTION OF THE INVENTION
In the context of the invention ‘dendrimers’ are understood to be three-dimensional, highly branched oligomeric or polymeric molecules. The dendrimers according to the invention may contain a nucleus, a number of generations of branches and terminal groups. A generation of branches consists of structural units ABx, in which x>or=2, which are radially bound to the nucleus or to the structural units of the previous generation and extend outwards. A subsequent generation may form because for example groups A react with groups B of the previous generation.
The structural units may either be the same with each subsequent generation (repeat themselves) or they may differ. Dendrimers can be characterised by a degree of branching. The ‘degree of branching’ of a dendrimer of a particular generation is here understood to be the ratio of the number of branches present and the maximum possible number of branches in a completely branched dendrimer of the same generation.
The branches may occur with varying degrees of regularity. The branches at the outside surface of the dendrimers used in the context of the invention may for example all be of the same generation, but they may also be of different generations. The latter may for example be the case if the synthesis of the dendrimers proceeds in a less controlled manner.
‘Dendrimers’ are according to the invention understood to be completely branched dendrimers, dendrimers with defects in their branched structure, dendrimers with an incomplete degree of branching, asymmetrically branched dendrimers, star polymers, highly branched polymers, highly branched copolymers and/or block copolymers of highly branched and non-highly branched polymers. Preferably the degree of branching is at least 50%, even more preferably at least 75%.
Preferably use is made of completely branched dendrimers, dendrimers with defects in their branched structure, dendrimers with an incomplete degree of branching, or asymmetrically branched dendrimers.
Because of the dendrimer's three-dimensional structure, there are cavities between the branches. The shape and the dimensions of these cavities vary in accordance with the generation, the chemical composition of the structural units and the degree of branching. It is possible to influence the degree of branching and the shape and dimensions of the cavities between the branches during the preparation of the dendrimer. This can be achieved among other ways by varying, for example the chemical composition, the structural units' molecular weight, by increasing or decreasing the degree of branching or by disturbing the regularity in the branches' composition.
It is possible to influence the degree in which and rate at which the active substance is absorbed into the moulded part by varying the cavities' shape and dimensions
The dendrimers' terminal groups consist of the non-reacted groups B of the structural units ABx. The terminal groups B may themselves be compatible with the plastic of the moulded part that is brought into contact with the active substance. If the terminal groups B are themselves not, or insufficiently, compatible with the plastic, the terminal groups B can be modified with the aid of a modifying compound to yield modified terminal groups that are compatible with the plastic.
The fact that the terminal groups are compatible with the plastic means that the dendrimer can be well dispersed in the plastic.
If the plastic of the moulded part is non-polar, a compound that is also non-polar is used as the modifying compound. If the plastic is polar, a compound that is also polar is used.
The type of modifying compound to be used will to a great extent depend on the modifying compound's reactivity with respect to the dendrimer's terminal group B. Preferably a compound is chosen that reacts as completely as possible with the dendrimer's terminal group.
Modifying compounds suitable for appending non-polar groups to the dendrimer's terminal groups are for example aliphatic halogenides, aliphatic alcohols, phenols, aliphatic and aromatic carboxylic acids, fatty acids, esters of aliphatic carboxylic acids and aromatic or aliphatic alcohols, esters of aromatic carboxylic acids and aromatic or aliphatic alcohols, aliphatic or aromatic epoxides, aliphatic or aromatic isocyanates, aliphatic or aromatic amides, aliphatic or aromatic amines, completely or incompletely fluorinated aliphatic compounds, sulphonic acids and derivatives of sulphonic acids, compounds containing phosphorus or compounds containing silicon. Mixtures of such compounds are also suitable. Preferably a compound that modifies the terminal group with an alkyl group is used as a non-polar compound, because this generally results in a very good compatibility with non-polar plastics, such as polyolefines. Examples of modifying compounds that modify the terminal groups with an alkyl group are fatty acids, alcohols derived from a fatty acid, amines derived from a fatty acid, isocyanates corresponding to a fatty acid, epoxides corresponding to a fatty acid and halogenides corresponding to a fatty acid. Examples are stearyl alcohol, dodecyl phenol, 4,4,5,5,5-pentafluoro-n-pentanol-1, stearamide, palmityl isocyanate, palmitoyl chloride, stearyl chloride, pentafluoropropionyl chloride, lauric acid, myristic acid, palmitic acid, stearic acid, perfluorononanoic acid and the mixture of alkane carboxylic acids known as “Montanwachs”. More preferably use is made of a saturated or (mono- or poly)unsaturated fatty acid.
Preferably use is made of a modifying compound that modifies the terminal group with an alkyl group having 6-50 C atoms, more preferably with an alkyl group having 12-30 atoms, even more preferably with an alkyl group having 16-20 atoms.
Other compounds suitable for modifying the terminal groups with non-polar groups are oligomer and/or polymer chains that are compatible with the plastic matrix into which the dendrimer must be mixed.
Compounds suitable for modifying the dendrimer's terminal groups with polar groups are for example polyacrylates, polymethacrylates, polyvinyl alcohols, polyvinyl esters, polyvinyl ethers, polyurethanes, polyurea, polyisocyanates, polyvinyl pyridines, polyvinyl pyrrolidones, polyethylene glycols, polyethylene imines, polycarbonates, polycaprolactones, nylons, styrene-acrylonitrile
de Brabander-van den Berg Ellen M. M.
Froehling Peter E.
Mostert Hubertus A. M.
DSM N.V.
Pillsbury Madison & Sutro Intellectual Property Group
Sanders Kriellion
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