Antistatic resin composition
A small account of polyvalent metal compound is added to an antistatic resin composition comprising a hydrophilic thermoplastic polymer. A shaped product of the resin composition retains permanent antistatic property and a beautiful appearance due to not only freeness from attachment of dust, etc., but also suppression of haze or discoloration caused by attachment of a gaseous soiling substance, such as an acidic and a basic gas in the air. The resin composition also provides a shaped container product free from occurrence of attached substance on an electronic part or optical part even when the part is subjected to irradiation with ultraviolet light after storage in the container product.
1 . An antistatic resin composition, comprising:
(a) a hydrophilic polymer: 3-100 wt. parts,
(b) a thermoplastic resin: 0-97 wt. parts (giving a total of 100 wt. parts together with the hydrophilic polymer (a)), and
(c) a polyvalent metal compound: 0.001-0.5 wt. part, said polyvalent metal compound being a polyvalent metal salt selected from the group consisting of magnesium chloride, calcium chloride, magnesium oleate, calcium stearate aluminum chloride and aluminum stearate.
2 . An antistatic resin composition according to claim 1 , wherein the polyvalent metal compound (c) is a polyvalent metal salt selected from the group consisting of calcium chloride, calcium stearate and aluminum stearate.
3 . An antistatic resin composition according to claim 1 , wherein the hydrophilic polymer (a) is a polyalkylene oxide group-containing polymer.
4 . An antistatic resin composition according to claim 3 , wherein the hydrophilic polymer (a) is a graft copolymer obtained by graft polymerizing an ethylenically unsaturated monomer onto a rubber trunk polymer having alkylene oxide groups.
5 . An antistatic resin composition according to claim 3 , wherein the hydrophilic polymer (a) is a graft-copolymer obtained by graft-polymerizing (iv) 5 to 95 wt. parts of at least one species of ethylenically unsaturated monomer onto a rubber trunk polymer in an amount of 5 to 95 wt. parts (giving a total of 100 wt. parts with the ethylenically unsaturated monomer), which rubber trunk polymer in turn is a copolymer of
(i) 50-95 wt. % of at least one monomer selected from conjugated dienes and acrylate esters,
(ii) 5-50 wt. % of at least one species of monomers each having 4 to 500 alkylene oxide groups and an ethylenic unsaturation, and
(iii) 0-40 wt. % of at least one species of ethylenically unsaturated monomer copolymerizable with the conjugated diene or acrylate ester (i).
6 . An antistatic resin composition according to claim 1 , further containing a surfactant (d).
7 . An antistatic resin composition according to claim 6 , wherein the surfactant (d) is at least one species of anionic surfactant selected from the group consisting of alkylbenzenesulfonic acid salts, alkylnaphthaenesulfonic acid salts, perfluoroalkylsulfonic acid salts, trifluoromethanesulfonic acid salts, perfluoroalkylcarboxylic acid salts and aliphatic acid salts.
8 . An antistatic resin composition according to claim 6 , wherein the surfactant (d) is an anionic surfactant comprising a salt of an alkaline metal having an atomic number of 19 (corresponding to potassium) or larger.
9 . An antistatic resin composition according to claim 1 , wherein the thermoplastic resin (b) is an aliphatic resin.
10 . A dispersion liquid obtained by dispersing an antistatic resin composition according to claim 1 in an organic solvent.
11 . A shaped product obtained by shaping an antistatic resin composition according to claim 1 .
12 . A shaped product according to claim 11 , which is resistant to thermal decomposition.
13 . A shaped product according to claim 11 , which is resistant to decomposition by irradiation with ultraviolet light.
14 . A shaped product according to claim 11 , which has a form of container for storing an electronic part or an optical part therein.
15 . A shaped product according to claim 14 , which has a form of container for storing an optical part comprising a photomask or a protective film for a photomask to be illuminative with laser light.
16 . Use of an antistatic resin composition for forming therefrom a container for storing a photomask or a protective film for a photomask to be illuminated with laser light, said antistatic resin composition comprising:
(a) a hydrophilic polymer: 3-100 wt. parts,
(b) a thermoplastic resin: 0-97 wt. parts (giving a total of 100 wt. parts together with the hydrophilic polymer (a)), and
(c) a polyvalent metal compound: 0.001-0.5 wt. part.