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# United States Patent [191 

# Eian 

# [ 54] PHOTOSENSITIVE SHEET MATERIALS 

[75] Inventor: Gilbert L. Eian, White Bear, Minn. 

(73] Assignee: Minnesota Mining and Manufacturing Company, St. Paul, Minn. 

(22] Filed: July 12, 1973 

(21] Appl. No.: 378,526 

[52] U.S. CI ..................... 96/48 R; 96/88; 96/114.1; 428/425 2 

[51] Int. Cl. .... G03C 5/24: G03C 1/00; G03C 1/02 

[58] Field of Search ...... 96/48 R, 48 HD, 88, 114.1; 117/36.8, 36.9; 428/425 

## [ 5 6] References Cited 

<img src='content_image/936113.jpg'>

## UNITED ST ATES PATENTS 

<img src='content_image/936118.jpg'>

<img src='content_image/936114.jpg'>

Primary Examiner-Mary F. Kelley Attorney, Agent, or Firm-Alexander, Sell, Steldt & DeLaHunt 

## [57] ABSTRACT 

Photosensitive sheet material, containing an acid› cleavable adduct of an image-forming first reactant and a reaction inhibitor together with a photolyzable source of halogen acid, which upon exposure to a light-image liberates said first reactant for reaction with a second reactant to produce a visible image, contains a controlled small amount of an acid accep› tor for reducing backgrounding and increasing con› trast in the resulting print. 

## 13 Claims, 1 Drawing Figure 

# [II] 3,935,012 

# [45] Jan. 27, 1976 

