Solvent-Based Inkjet-Printed Negatives for Making Flexo Plates

1 . A solvent-based inkjet negative, comprising:

a polymeric film compatible with solvent-based ink and having inked areas;

the polymeric film being thin in one dimension, broad in the two other dimensions, a surface in

the two other dimensions to be illuminated by a light having an initial intensity;

a first combination of light filtering substances uniformly spread in the other two dimensions;

the ink comprising a second combination of light filtering substances;

the first and second combinations of light filtering substances preventing polymerization of photopolymers opposite to the surface to be illuminated when light is shone on the surface to be illuminated.

2 . The negative of claim 1 , in which:

said first combination of light filtering substances is taken from the list of:

a. none;

b. at least one layer of fluorescent substance;

c. at least one layer of light-reflecting substance;

d. at least one layer of light absorbing substance;

e. at least one fluorescent substance dispersed within the film;

f. at least one light-reflecting substance dispersed within the film;

g. at least one light absorbing substance dispersed within the film; and

h. any combination of b. through g. above.

3 . The negative of claim 1 , in which:

said second combination of light filtering substances is taken from the list of:

a. none;

b. a fluorescent substance;

c. a light-reflecting substance;

d. a light absorbing substance; and

e. any combination of b. through d. above.

4 . The negative of claim 1 , in which:

said first combination of light filtering substances is taken from the list of:

a. none;

b. at least one layer of fluorescent substance;

c. at least one layer of light-reflecting substance;

d. at least one layer of light absorbing substance;

e. at least one fluorescent substance dispersed within the film;

f. at least one light-reflecting substance dispersed within the film;

g. at least one light absorbing substance dispersed within the film; and

h. any combination of b. through g. above; and

said second combination of light filtering substances is taken from the list of:

i. none;

j. a fluorescent substance;

k. a light-reflecting substance;

l. a light absorbing substance; and

m. any combination of j. through l. above.

5 . The negative of claim 1 , in which:

said first combination of light filtering substances reduces the initial intensity by at least 50%; and

said second combination of light filtering substances reduces the initial intensity by at least an additional 30 percentage points.

6 . A light filtering laminate, comprising:

at least one layer comprising a first substance taken from the list of:

a. at least one substance which absorbs light of a specified wavelength range and fluoresces in a wavelength other than the specified wavelength range;

b. at least one substance that reflects light of a specified wavelength range away from the layer of photoreactive material;

c. at least one substance that absorbs light of a specified wavelength range and converts it to heat; and

d. any combination of a. through c. above; and

at least one layer printed with a negative image comprising a solvent-based ink,

the ink comprising a second substance taken from the list of:

a. at least one substance which absorbs light of a specified wavelength range and fluoresces in a wavelength other than the specified wavelength range;

b. at least one substance that reflects light of a specified wavelength range away from the photoreactive material;

c. at least one substance that absorbs light of a specified wavelength range and converts it to heat; and

d. any combination of a. through c. above.

7 . The light filtering laminate of claim 6 , wherein:

said at least one layer comprising a first substance and said at least one layer printed with a negative image are one and the same.

8 . The light filtering laminate of claim 7 , in which:

said specified wavelength range is about 200 to 400 nanometers.

9 . The light filtering laminate of claim 7 , in which:

said specified wavelength range is about 240 to 360 nanometers.

10 . The light filtering laminate of claim 6 , in which:

the unprinted areas in said light filtering laminate reduce the intensity of light impinging on said filtering laminate by at least 50%; and

said ink reduces the light passing through the unprinted areas by at least an additional 30 percentage points.

11 . A method for making a light filtering laminate, comprising the steps of:

a. adding at least one light filtering substance to at least one layer of light transmitting material;

b. adding at least one light filtering substance to a solvent-based inkjet printing ink;

c. using the ink from step b. to print a negative image on at least one layer of film compatible with solvent-based inkjet ink; and

d. superimposing any resulting plurality of layers.

12 . The method of claim 11 , in which:

said light filtering substance is taken from the list of:

a. at least one substance which absorbs light of a specified wavelength range and fluoresces in a wavelength other than a specified wavelength range;

b. at least one substance that reflects light of a specified wavelength range away from the photo reactive material; and

c. at least one substance that absorbs light of a specified wavelength range and converts it to heat.

13 . The method of claim 12 , in which:

said specified wavelength range is about 200 to 400 nanometers.

14 . The method of claim 12 , in which:

said specified wavelength range is about 240 to 360 nanometers.

15 . The method of claim 11 , in which:

the unprinted areas in said light filtering laminate reduce the intensity of light impinging on said light filtering laminate by at least 50%; and

said ink further reduces the intensity of light passing through the laminate by at least an additional 30 percentage points.