EP1375615A2

Hardcoat compositions and hardcoated articles

Abstract

A hardcoat composition comprising (A) a hydrolytic condensate of a hydrolyzable silicon compound of formula: R1aSiX(4-a) with at least 1 mole of water per mole of hydrolyzable group X, (B) a metal oxide, (C) a siloxane resin of formula: R2bSi(OR3)c(OH)dO(4-b-c-d)/2 and having a Mw of at least 2,000, which is solid at a temperature of not higher than 40°C, and (D) a curing catalyst forms a hardcoat film having satisfactory hardness, transparency and adhesion as well as improved weather resistance and presenting a surface that is repellent to marker ink.

EP1375615A2, drawing sheet 1
Sheet 1 of 1

Term

Term ended

Projected expiry passed 16 June 2023, 3.3 years ago.

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10 claims: 7 independent, 3 dependent

  1. 1
    A hardcoat composition comprising (A) a hydrolytic condensate obtained by hydrolytic condensation of at least one hydrolyzable silicon compound of the general formula (1):R 1 a SiX (4-a)      (1) wherein R 1 is an organic group having 1 to 18 carbon atoms, X is a hydrolyzable group, and "a" is an integer of 0 to 2, with the proviso that a compound of only a=0 and a compound of only a=2 are excluded, with at least 1 mole of water per mole of the hydrolyzable group X, (B) a metal oxide, (C) a siloxane resin represented by the average compositional formula (2):         R 2 b Si(OR 3 ) c (OH) d O (4-b-c-d)/2      (2) wherein R 2 is independently an organic group having 1 to 18 carbon atoms, R 3 is independently an organic group having 1 to 4 carbon atoms, b, c and d are numbers satisfying 0.8 ≤ b ≤ 1.5, 0 ≤ c ≤ 0.3, 0.001 ≤ d ≤ 0.5, and 0.801 ≤ b+c+d < 2, and having a weight average molecular weight of at least 2,000, which is solid at a temperature of not higher than 40°C, and (D) a curing catalyst.
  2. 4
    The hardcoat composition of any one of claims 1 to 3 wherein the metal oxide (B) is an oxide or compound oxide of at least one metal selected from the group consisting of silicon, titanium, zirconium, hafnium, zinc, iron, antimony, tin, cerium, and aluminum.
  3. 5
    The hardcoat composition of any one of claims 1 to 4 wherein the siloxane resin (C) has a softening point of 60 to 90° C.
  4. 6
    The hardcoat composition of any one of claims 1 to 5 wherein at least 70 mol% of siloxane units of which the siloxane resin (C) is constructed are siloxane units of the general formula (3):R 4 SiO 3/2      (3) wherein R 4 is independently an organic group having 1 to 18 carbon atoms, at least 80 mol% of R 4 being an organic group having 1 to 6 carbon atoms.
  5. 7
    The hardcoat composition of any one of claims 1 to 6, further comprising (E) a hydrolyzate or hydrolytic condensate of a reaction product or mixture of a metal alkoxide having the general formula (4):M(OR 5 ) n      (4) wherein M is at least one metal selected from the group consisting of Ti, Zr, Hf, Al, Fe, Zn, In, Cu, Sn, W and Ce, n is the valence of the metal, and R 5 is an organic group having 1 to 6 carbon atoms, with a β-diketone and/or β-ketoester, in an amount of 1 to 30 parts by weight per 100 parts by weight of components (A) and (B) combined.
  6. 9
    An article comprising a substrate and a hardcoat film which is formed on the substrate by applying and curing the hardcoat composition of any one of claims 1 to 8 thereto.
  7. 10
    An article comprising a plastic substrate having a primer layer on a surface and a hardcoat film which is formed on the substrate by applying and curing the hardcoat composition of any one of claims 1 to 8 to the primer layer on the substrate.