TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: Swollen particles (BA) are obtained during homogenous mixing of cross-linked polymer and potassium hydroxide aqueous solution at 25degreesC. The swollen particles with particle diameter of 32-1000 microns is at least 80 wt.% with respect to the total weight of swollen particles (BA). The absorbed quantity of cross-linked polymer after homogenous mixing with 37 wt.% potassium hydroxide aqueous solution for 1 hour, is 20-60 g/g according to teabag method.Preferred Polymer: The cross-linked polymer comprises alkaline hydrolysable cross-linking agent unit (b) and alkaline non-hydrolysable cross-linking agent (c) in weight ratio (b/c) of 0.4-2.5. The cross-linking-agent unit is a compound having ester bond and/or amide bond, or forms a compound having ester bond and/or amide bond. The cross-linking agent unit (c) has 3-10C allyl and 1-5 hydroxyl. The content of metallic element having ionization tendency lower than zinc in the gelatinizer is 15x10-4 wt.% or less. The amount of cross-linking agents (b, c) is 0.05-3 wt.% with respect to weight of (meth)acrylic acid or its salt in the cross-linked polymer.Preferred Process: The gelatinizer is obtained by aqueous solution polymerization or reverse phase suspension polymerization by using allyl ether group cross-linking agent (c) that has 2-10 allyl groups that are decomposed under alkaline conditions, and cross-linking agent (b). EXAMPLE - Trimethylolpropane triacrylate (in g) (0.6), acrylic acid (200) and pentaerythritol triarylether (0.6) were added to beaker (2 l), stirred and cooled to 80degreesC. The obtained aqueous solution of acrylic acid was added to a heat insulated polymerization tank. 0.1 wt.% hydrogen peroxide solution (4), 0.1 wt.% L-ascorbic acid aqueous solution (4) and 10 wt.% 2,2'-azobis(2-amidinopropane)hydrochloride aqueous solution (1) were then added to the polymerization tank and polymerized. The obtained polymer had average polymerization degree of 28000. The cross-linked block-shaped water-containing gel was removed from the polymerization tank. The gel was divided into a size of 3-10 mm diameter. 40 wt.% sodium hydroxide aqueous solution (222) was added and the gel was neutralized. The neutralized gel was laminated on the steel screen having aperture diameter of 850 microns. The gel was treated with hot air, and dried. The dried product was then ground and sieved to a particle size of 32-500 microns. Thus, gelatinizer was obtained. The content of particles with diameter of 32-1000 microns was 95 wt.% and content of particles with diameter of 45-850 microns was 92 microns. The content of metallic element in the gelatinizer was 1.9x10-4 wt.%. The gel viscosity ratio of the gelatinizer was 0.88. The absorbed quantity of the polymer in gelatininzer with respect to 37 wt.% potassium hydroxide aqueous solution was 35 g/g. Alkaline battery excellent in impact strength and long-term retention of discharge characteristics was provided using the obtained gelatinizer.