What are the types of thickeners?

　　There are many kinds of thickeners, including inorganic thickeners, cellulose, polyacrylate and associative polyurethane thickeners. Cellulose thickeners have a long history and many varieties, including methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, etc., which used to be the mainstream of thickeners, among which hydroxyethyl cellulose is the most commonly used. Polyacrylate thickener can be basically divided into two types: one is water-soluble polyacrylate; The other is the homopolymer or copolymer emulsion thickener of acrylic acid and methacrylic acid, which is acidic in itself and needs to be neutralized to pH8~9 with alkali or ammonia water to achieve thickening effect, also known as acrylic acid alkali swelling thickener. Polyurethane thickener is a newly developed associative thickener in recent years. Inorganic thic kener is a kind of thixotropic gel mineral formed by water absorption and swelling. There are mainly bentonite, attapulgite and aluminum silicate, among which bentonite is the most commonly used.

　　Thickeners actually used can be divided into two categories according to the mechanism of action: water-phase thickener and oil-phase thickener. The fo rmer has many varieties, while the latter is quite few.

　　Thickeners have the following categories:

　　(1) Inorganic thickener (fumed silica, sodium bentonite, organobentonite, diatomite, attapulgite, molecular sieve, silica gel).

　　(2) Cellulose ether (methyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose).

　　(3) Natural polymers and their derivatives (starch, gelatin, sodium alginate, casein, guar gum, chitosan, Arabic gum, xanthan gum, soy protein gum, natural rubber, lanolin and agar).

　　(4) Synthetic polymers (polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, modified paraffin resin, carbomer resin, polyacrylic acid, polyacrylate copolymer emulsion, butadiene rubber, styrene-butadiene rubber, polyurethane, modified polyurea and low molecular weight polyethylene wax).

　　(5) Complex organometallic compound (amino alcohol complex titanate).

　　(6) printing thickener includes (dispersed thickener, coating thickener and active thickener).