Toyo Boseki Kabushiki Kaisha

Hiroshi Tachika

Hiroshi Fujimoto

Masami Oka

Keiichiro Togawa

Hiroshi Murata

Kuniyuki Doi

Kenji Ohama

Takao Aoki

This invention offers a coating resin composition which exhibits excellent drawing processability, processability and hardness and forms a coat having good processability, hardness, scuff resistance, impact resistance, stain resistance and blocking resistance even in clear or low pigment concentration. Disclosed herein is a coating resin composition containing a polyester resin (A) which has a glass transition point of 10-80.degree. C., reduced viscosity of not less than 0.2 dl/g and specific gravitity of 1.21-1.30 and mainly comprises aromatic dicarboxylic acid including terephthalic acid, 2-methyl-1,3-propanediol and/or 1,3-propanediol and alkylene glycol with 5-10 carbon atoms and/or alicyclic glycol and a hardener (B) which is reactive with said polyester resin (A).

Coating resin composition

A coat resin composition comprising a polyester (A) comprising an acid component comprising an aromatic dicarboxylic acid in a proportion of 50-100% by mole relative to the entire acid component and other carboxylic acid(s) in a proportion of 50-0% by mole relative to the entire acid component, and a glycol component comprising 2-methyl-1,3-propanediol and/or 1,3-propanediol in a proportion of 1-25% by mole relative to the entire glycol component and an alkylene glycol having 5 to 10 carbon atoms in a proportion of 75-99% by mole relative to the entire glycol component, or an alicyclic glycol in a proportion of 20-85% by mole relative to the entire glycol component, an addition product of bisphenol A with alkylene oxide in a proportion of 80-15% by mole relative to the entire glycol component and other glycol(s) in a proportion of 0-50% by mole relative to the entire glycol component, wherein the total of the glycols is 100% by mole, the polyester (A) having a reduced viscosity of not less than 0.2 dl/g; and a curing agent (B) reactive with the polyester (A), in a proportion of (A)/(B)=99/1--50/50 (weight ratio). The present invention provides coating resin compositions capable of forming a coating film having superior processability, hardness, stain resistance, weatherability, resistance to staining by foodstuffs, or superior boiling water resistance, corrosion resistance, acid resistance and scratch property.

Coating resin compositions

A resin composition for coating of the present invention includes a polyester containing an acid component and a polyol component, wherein the polyester is soluble or dispersible in a solvent consisting essentially of at least one solvent selected from the group consisting of cyclohexanone and isophorone; the polyester has a metal sulfonate group in an amount in the range of 0.1 to 5 mol % based on the total moles of the acid component or the polyol component and is slightly soluble in an organic solvent in the case where the content of the metal sulfonate group is 0%; and a specific gravity of the polyester at 30.degree. C. is in the range of 1.265 to 1.340.

Resin composition for coating

An aqueous dispersion comprising (A) a polyester comprising an aromatic dicarboxylic acid, an addition product of bisphenol A with ethylene oxide and/or propylene oxide, and a dicarboxylic acid having a metal base of sulfonic acid and/or a polyol having a metal base of sulfonic acid, (B) a water-soluble organic compound having a boiling temperature of about 60.degree. C. to about 250.degree. C., (C) water and (D) a neutralizer; the amounts of the components A, B, C and D satisfying the following ratios of (1) to (3):

Aqueous polyester dispersion suitable for use as a coating composition

An aqueous dispersion suitable for use as various coatings is provided. The dispersion includes polyester resin (A), a water soluble organic compound (B), water (C), and a neutralizer (D). The polyester resin has an acid number of 50 equivalents/10.sup.6 g or more. The polycarboxylic acid component of the resin contains aromatic dicarboxylic acid having no metal sulfonate groups in an amount in the range of 50 to 99.99 mole percent, and dicarboxylic acid having a metal sulfonate group in an amount in the range of 0.01 to 20 mole percent based on the total moles of the polycarboxylic acid component. The polyol component of the resin contains diol in an amount in the range of 30 to 100 mole percent based on the total moles of the polyol component. The diol has an alkyl group with 1 to 3 carbon atoms on a side chain, and the total number of carbon atoms in the diol is 6 to 25. The water soluble organic compound has a boiling point in the range of 60.degree. to 250.degree. C. The components (A), (B), and (C) are contained in the dispersion in an amount in the range of 1 to 70 percent by weight, 0 to 69 percent by weight, and 9 to 99 percent by weight, respectively. Further, the components (A), (B), (C), and (D) satisfy the following expressions (1) and (2):

Aqueous dispersion

Provided is a coating composition for a two-piece can containing a polyester resin (A) consisting essentially of terephthalic acid and propylene glycol and containing tri- or more functional polycarboxylic acid or polyol comonomer(s) and an alkyl-etherified aminoformaldehyde resin (B); and the coating film (C) to be obtained by reacting these (A) and (B) in the composition has larger tensile strength and elongation than the film made of only (A). The coating composition is coated on at least one surface of a metal sheet to give a coated metal sheet for a two-piece can. The coated metal sheet may be formed into a drawn and ironed can or a drawn and re-drawn can. The adhesiveness of the coated film to the metal sheet is high, and the coated film has excellent resistance to blistering and resistance to whitening and has excellent flavor preservability.

Growing community of inventors

Ohtsu, Japan

Hiroshi Tachika