Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2003-01-29
2004-06-15
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S270100, C430S302000, C430S570000, C430S915000, C430S916000, C430S925000, C430S926000, C522S026000, C522S063000, C522S066000, C522S067000
Reexamination Certificate
active
06749995
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a light sensitive composition, a light sensitive planographic printing plate precursor and an image formation method, and particular to a light sensitive composition, a light sensitive planographic printing plate precursor and an image formation method used in CTP (Computer To Plate), which records digital data employing an infrared laser.
BACKGROUND OF THE INVENTION
A planographic printing plate is obtained by imagewise exposing a planographic printing plate precursor to harden exposed portions, dissolving the non-exposed portions of the exposed precursor with a developer, washing the resulting precursor with water, and finisher gum treating the washed precursor. Recently, a method has been studied in which a planographic printing plate precursor is digitally exposed based on image information employing laser ray, and developed with a developer to form an image with high resolution and high sharpness. As one embodiment, there is a system manufacturing a planographic printing plate in which a light sensitive planographic printing plate precursor is scanning exposed employing a light source modulated with an image signal transmitted by communication line or output signal from an electronic plate making system or an image processing system.
However, a conventional planographic printing plate precursor employing a diazo resin has problem in that spectral sensitization to suit a wavelength of laser ray and obtain high sensitivity is difficult.
Recently, a planographic printing plate precursor comprising a photopolymerizable light sensitive layer containing a photopolymerization initiator has been noted as a printing plate precursor for digital exposure employing a laser light, since it is possible to provide a light sensitive layer highly sensitive to the laser light. A printing plate precursor for CTP recording digital data employing such a laser light is required to be more highly light-sensitive for the purpose of carrying out recording in a short time.
The planographic printing plate precursor is said to be suitable for forming an image with high sensitivity which comprises a photopolymerizable light sensitive layer containing a photopolymerization initiator, since the photopolymerization initiator imagewise generates radicals on imagewise exposure, and the resulting radicals cause radical chain polymerization as radical initiating species.
As a method for adapting a photopolymerizable composition to a laser light in CTP, a technique is known and put into practical use in which a spectral sensitizing dye having sensitivity to a wavelength of the laser light is used in combination with a radical generating agent which is dissociated by energy transfer or electron transfer from the spectral sensitizing dye to generate radicals.
In the conventional CTP system which employs a photopolymerizable composition containing the photopolymerization initiator and the spectral sensitizing dye described above in combination with a visible light source having a longer wavelength such as an Ar laser (488 nm) or an FD-YAG laser (532 nm) as a light source, writing at a higher speed is required for the purpose of increasing productivity of printing plate in the plate making process. However, such a purpose has not yet been attained, since output of the light source is not sufficiently high, or sensitivity of the planographic printing plate precursor is not so high.
In recent years, semiconductor lasers employing, for example, InGaN type material, which can continuously emit light with a wavelength of from 380 to 430 nm, are about to be put into practical use. A scanning exposure system employing light with such a short wavelength as a light source has advantages providing sufficient output and an economical system, since the semiconductor laser can be structurally manufactured at low cost. Further, a planographic printing plate precursor to be applied to the above light source has a spectral sensitivity shorter than that of a planographic printing plate precursor to be applied to a system employing a conventional FD-YAG laser or Ar laser, and therefore, operation under safe light is easy.
Several photopolymerizable compositions are known which can be applied to the semiconductor laser with the short wavelength. The light sensitive compositions are disclosed and proposed in for example, Japanese Patent O.P.I. Publication Nos. 2001-42524, 2000-309724, 2000-258910, 2000-206690, 2000-147763, and 2000-98605.
However, the photopolymerizable compositions proposed above, when applied to a planographic printing plate precursor for CTP, have problems in that sensitivity is insufficient, sensitivity is lowered during a long term storage, and unexposed portions are hardened due to dark reaction, which results in staining during printing. Technique solving the above problems has been required.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above. An object of the invention is to provide a light sensitive composition, a light sensitive planographic printing plate precursor, and image formation method which provide high sensitivity and excellent storage stability.
DETAILED EXPLANATION OF THE INVENTION
[Means for Solving the Problems]
The above objects of the invention can be attained by the followings:
1. A light sensitive composition containing a compound represented by the following formula (1):
wherein R
1
, R
2
and R
3
independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, provided that R
1
and R
2
may combine with each other to form a ring or R
2
and R
3
may combine with each other to form a ring.
2. The light sensitive composition of item 1 above, wherein the formula (1) is represented by the following formula (2):
wherein R
4
represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; R
5
and R
6
represent a radical and combine with each other to form a ring; and X
1
and X
2
independently represent —CR
7
R
8
—, —O—, —S—, or —NR
9
—, in which R
7
, R
8
, and R
9
independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.
3. The light sensitive composition of item 1 above, wherein the light sensitive composition contains a monomer having an addition polymerizable ethylenically unsaturated bond.
4. The light sensitive composition of item 3 above, wherein the light sensitive composition further contains a compound represented by the following formula (3) or (4):
wherein R
10
and R
11
independently represent a substituted or unsubstituted aryl group; and R
12
represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group,
wherein R
13
represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group; R
14
and R
15
independently represent a substituted or unsubstituted alkyl group, provided that R
14
and R
15
may combine with each other to form a ring; R
16
and R
17
independently represent a substituted or unsubstituted alkyl group, provided that R
16
and R
17
may combine with each other to form a ring; X
3
represents ═O, ═NR
18
, or ═S in which R
18
represents a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.
5. The light sensitive composition of item 1 above, wherein the light sensitive composition further contains a tita
Konica Corporation
Muserlian Lucas and Mercanti
Schilling Richard L.
LandOfFree
Light sensitive composition, light sensitive planographic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Light sensitive composition, light sensitive planographic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Light sensitive composition, light sensitive planographic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3347579