Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-09-06
2003-01-07
Acquah, Samuel A. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C528S274000, C528S295000, C528S298000, C528S308000, C528S308600, C524S601000, C524S604000, C524S605000, C524S609000, C524S812000
Reexamination Certificate
active
06503982
ABSTRACT:
The subject of the present invention is a process for gelling aqueous media with the aid of copolyester oligomers, the use of copolyester oligomers as gelling agents for aqueous media and of new gelling copolyester oligomers for aqueous media.
A first subject of the invention relates to a process for gelling aqueous media by introducing into the said media an effective quantity of at least one water-soluble or water-dispersible copolyester oligomer comprising essentially dicarboxylate units of formula (I)
[—CO—A—CO—O—X—O] (I)
in which formula
A represents an aromatic or aliphatic divalent hydrocarbon group,
X represents a divalent alkylene, cycloalkylene or polyoxyalkylene group,
at least 35 mol %, preferably at least 40 mol %, most particularly from 40 to 70 mol % of the said units of formula (I) being similar units whose corresponding homopolymer is crystalline,
at least 7 mol %, preferably at least 10 mol %, most particularly 10 to 25 mol % of the said units of formula (I) being units in which the group A is a carrier of hydrophilic functional group(s).
Among the groups A of the units of formula (I), there may be mentioned:
the C
6
-C
14
mono- or polyarylene groups, the C
1
-C
9
alkylene groups, not carrying a hydrophilic functional group, such as the 1,4-phenylene, 1,3-phenylene, 1,6-naphthalene, 1,6-cyclohexylene, ethylene, trimethylene, tetramethylene or hexamethylene groups;
the C
6
-C
14
mono- or polyarylene groups, or C
1
-C
9
alkylene groups, carrying hydrophilic, preferably anionic, functional group(s), in particular sulphonates of alkali metals, most particularly sodium, or sulphonates of mono-, di-, tri- or tetraalkylammonium in which the alkyl radical is a C
1
-C
20
radical, such as sulpho-1,4-phenylene, sulpho-1,3-phenylene, sulpho-1,2-phenylene, sulphonaphthalene, sulphobiphenylene or sulphoethylene groups.
Among the groups X of the units of formula (I), there may be mentioned the
C
2
-C
10
alkylene groups, such as polymethylenes (—CH
2
—)
x
with x ranging from 2 to 10, 2,2-dimethylpropanediyl, 1,6-cyclohexylene,
polyoxyalkylene groups of formula (—Y—O)
y
Y—, Y representing a C
2
-C
4
alkylene, in particular ethylene, group, y ranging from 1 to 5.
Among the units of formula (I) in which the corresponding homopolymer is crystalline, there may be mentioned in particular those in which the corresponding homopolymers are polyterephthalates, polyisophthalates, polynaphthates, polyhexahydro-terephthalates, polysebacates, polyadipates and polyazelates of ethylene glycol, dioxyethylene glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, 2,2-dimethy-1,3-propanediol or 1,6-cyclohexanediol.
Preferably, the said units of formula (I) are chosen from those whose corresponding homopolymer has a melting point greater than the desired temperature for obtaining the gelling of the aqueous medium to be gelled, this desired gelling temperature being most generally close to room temperature, that is to say of the order of 10 to 40° C.
Thus, there may be mentioned most particularly the units of formula (I) whose corresponding homopolymer is one of the following homopolymers, whose melting temperature is given in particular in “Properties of polymers” by D. W. VAN KREVELEN (Elsevier Publishing Company 1972):
polyethylene terephthalate, of melting point tc=284° C.
polydecamethylene terephthalate, of melting point tc=138° C.
polyethylene adipate, of melting point tc=65° C.
polydecamethylene adipate, of melting point tc=85° C.
The chain ends of the copolyester oligomers used for carrying out the process of the invention may be similar or different and chosen from the groups of formulae
—A—CO—O—(X—O)
n
—H (II
1
)
the said groups (II
1
) being optionally at least partially sulphated or phosphated,
in which formulae
A, X and n have the meaning given above,
Z represents a C
2
-C
31
alkyloyl or aryloyl group optionally carrying an anionic, preferably sulphonate, functional group such as sulphobenzoyl MO
3
SC
6
H
4
C(O)— where M is an alkali metal
Z′ represents a polyalkoxysulphonate group, in particular of formula (MO
3
S)(CH
2
)
q
(CH
2
—CH
2
—O)(RO)
r
—, where M is an alkali metal, q is equal to 0 or 1, R is an ethylene or propylene group, r ranges from 0 to 2
X′ represents a C
2
-C
8
alkylene group, Z″ represents a C
1
-C
30
alkyl or aryl group and p ranges from 0 to 6.
Other units may, in addition, be present at the chain ends and in minor quantities, such as groups of formula
—A—CO—OH (II5)
where A has the meaning given above.
Preferably, the weight-average molecular mass of the said copolyester oligomers is less than 20,000, preferably less than 15,000, most particularly from 5000 to 10,000.
The weight-average molecular masses are measured by gel permeation chromatography, in dimethylacetamide containing 10
−2
N LiBr, at 100° C. The results are expressed as polystyrene equivalents.
The said copolyester oligomers can be obtained by the customary processes for preparing polyesters by the molten route, the solvent route or the interfacial route, which processes involve the following reactions:
esterification of diacids and of diols and polycondensation
transesterification of diesters and of diols and polycondensation
autocondensation of hydroxy acids
Schotten-Baumann reaction using diols and acid chlorides and polycondensation
polymerization of lactones by controlling the minimum content of similar units (I) by the initial stoichiometric ratios of the various monomers and by controlling side reactions.
A particularly advantageous mode of preparation is that by transesterification/polycondensation and/or esterification/polycondensation by the molten route with the aid of a transesterification and/or esterification catalyst.
Control of the structure is obtained by controlling the minimum content of similar units (I) by the initial stoichiometric ratios of the different diacid and/or diester and diol monomers and by using an etherification-limiting agent, which limiting agent may be a basic compound such as aliphatic or aromatic amines or a hydroxide or acetate of alkali or alkaline-earth metals.
Control of the molecular mass is obtained in a manner known to persons skilled in the art, by a suitable compromise between pressure, temperature and time, and/or by introducing a monofunctional monomer.
The production of chain ends of formula of the (II
2
), (II
3
) and (II
4
) type can be achieved using monoacid monomers for the chain ends of formula (II
2
), a hydroxypolyalkoxyalkylsulphonate for the chain ends of formula (II
3
), a polyalkylene glycol monoether or a monoalcohol for the chain ends of formula (II
4
).
Terminal groups of formula (I
1
) which are at least partially sulphated or phosphated can be obtained, if desired, by treating the copolyester oligomer prepared, with the aid of sulphuric, sulphamic or phosphoric acid.
One type of water-soluble or water-dispersible copolyester oligomer particularly well suited to the process of the invention consists in water-soluble or water-dispersible copolyester oligomers having dicarboxylate repeating units of formula (I), at least 35 mol %, preferably 40 mol %, most particularly from 40 to 70 mol % of the said units of formula (I) being similar units whose group A represents a 1,4-phenylene, 1,3-phenylene, 1,6-naphthalene, 1,6-cyclohexylene, ethylene, trimethylene, tetramethylene or hexamethylene group and the group X represents a C
2
-C
1
alkylene group, preferably ethylene, tetramethylene, hexamethylene, octamethylene, decamethylene or ethylene oxyethylene and whose corresponding homopolymer is crystalline.
Among the copolyester oligomers which are particularly suitable for carrying out the invention, there may be mentioned the water-soluble or water-dispersible copolyester oligomers comprising essentially dicarboxylate units of formula (I′)
[—CO—A′—CO—O—(CH
2
—CH
2
—O)
n′
—] (I′)
in which formula
A′ represents a 1,4-phenylene, 1,3-phenylen
Fleury Etienne
Ricca Jean-Marc
Acquah Samuel A.
Rhodia Chimie
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