Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
66 words
An envelope having flexible water-permeable or porous walls and a given maximum non-stretched internal volume and containing a quantity of particulate water-insoluble hydrogel in the closed envelope characterised in that the volume of the quantity of hydrogel when fully swollen at 20°C amounts to at least 66% of the given maximum non-stretched internal volume but is insufficient when fully swollen at 20°C to rupture the envelope.
Claim 2
Dependent Claim
66 words
An envelope having flexible water-permeable or porous walls and a given maximum non-stretched internal volume and containing a quantity of particulate water-insoluble hydrogel in the closed envelope characterised in that the volume of the quantity of hydrogel when fully swollen at 20°C amounts to at least 66% of the given maximum non-stretched internal volume but is insufficient when fully swollen at 20°C to rupture the envelope.
Claim 3
Dependent Claim
30 words
An envelope according to claim 1 characterised in that the quantity of hydrogel when fully swollen at 20°C amounts to at least 100% of the given maximum non-stretched internal volume.
Claim 4
Dependent Claim
18 words
An envelope according to claim 1 or 2 characterised in that the hydrogel is a crosslinked polyethylene glycol.
Claim 5
Dependent Claim
27 words
An envelope according to any one of the preceding claims characterised in that it also comprises a biologically, veterinarily or pharmaceutically active ingredient in sustained release form.
Claim 6
Dependent Claim
25 words
An envelope according to claim 4 characterised in that it contains a mixture of hydrogel particles and particles of active ingredient in sustained release form.
Claim 7
Dependent Claim
22 words
An envelope according to claim 4 characterised in that the active ingredient in sustained release form is contained in the hydrogel particles.
Claim 8
Dependent Claim
10 words
An envelope according to any one of claims 4 to
Claim 9
Dependent Claim
12 words
6 characterised in that it is in the form of a toroid.
Claim 10
Dependent Claim
12 words
6 characterised in that it is in the form of a toroid.
Claim 11
Independent Claim
38 words
A method of removing water from a mixture with a non-aqueous liquid characterised in that the water is absorbed from the mixture by the hydrogel in an envelope as claimed in any one of claims 1 to 3.
Claim 12
Dependent Claim
40 words
A self-erecting three dimensional structure characterised in that it comprises a single envelope according to any one of claims 1 to 3 or it comprises a plurality of envelopes according to any one of claims 1 to 3 joined together.
Claim 13
Independent Claim
60 words
A method of purifying sea-water characterised in that a plurality of envelopes according to any one of claims 1 to 3 are contacted with sea-water to absorb water from the sea, the swollen envelopes are drained of non-absorbed water, the drained envelopes are exposed to sunlight to cause absorbed water to be desorbed and the desorbed water is then condensed.