In the recent period, many comments have been made on the thermal CTP and the violet CTP. This article focuses on the thermal CTP and the violet CTP using a photosensitive resin, and introduces its technology and future trends.
Basic situation of thermal CTP and violet laser CTP
The photosensitive resin CTP for ultraviolet rays is a double-layered structure in which an oxygen protective layer is attached to the photopolymerizable layer. In contrast, the photosensitive layer of the thermosensitive CTP is a single layer. In addition, since it is a heat-sensitive recording means that generates heat using laser light, it is not easily influenced by light or scattering due to light, and faithful dot reproducibility is easily obtained. Since light reaction is not used, it is also possible under white light. Platemaking.
In addition, because the ultraviolet laser imager uses a small, inexpensive laser for second-generation DVDs, the maintenance cost of the laser setter can be greatly reduced by the maintenance cost of the laser setter. The thermal imager (Thermalsetter) has already been supplied by more than a dozen companies such as CreoScitex, Dainippon Screen, etc. The maintenance service is relatively considerate, and the degree of technical perfection meets various kinds of application and size specifications. In addition, Thermal CTP has been sold by many companies such as Aafa, Fuji Photo Film, KPG, etc., and it has become a mature and practical field. At present, it is being promoted at a double speed every year.
Since last year, the Violet setter has been published successively from seven European companies, all of which use low-output lasers of 5mW. However, there are not many manufacturers that supply the applicable CTP plates. It is estimated that there will be soon. An imaging machine loaded with a 30mW laser was introduced.
Key technologies of thermal CTP and violet laser CTP
Thermal CTP
Thermal CTP was released in 1995. The negative graph type is ahead of the positive graph type development. The negative graph type thermal sensitive CTP is due to the use of a photo-oxygen generating agent to cause a thermal polycondensation reaction, which requires heat after exposure, and thus is easy to image quality. Deviations were created. By 1997, new positive-type thermal CTPs that did not require such heating had finally been released and have now become mainstream.
This type of printing plate incorporates a near-infrared pigment in a binder polymer matrix. This pigment absorbs near-infrared light and undergoes thermal conversion so that the exposed part of the polymer matrix becomes soluble in a basic substance. Make a plate that forms a positive image. It is also possible to complete the laser plate-making work under white light without any photochemical reaction.
If the high-output thermal laser light is converged and then projected onto the CTP, it reaches a high temperature of about 100°C near the surface of the photosensitive layer of about 2 μm thick, but the photosensitive layer near the aluminum substrate having a high thermal conductivity is only about 500. °C, expressed as a relatively low temperature, there is a big gap between the two. For this reason, it is difficult to make development contrast. Thus, a polymer matrix structure with a high density can be formed near the control surface for different temperature distributions, and a physical and chemical method has been developed by Mitsubishi Chemical Corporation, namely, a photosensitive resin layer nanostructure control (Photpolymer Layer Nano). Structure Control (referred to as PNSC technology). Listed on the market since 1998, the development stability, surface strength, print resistance, and image quality are all excellent. Japan's original Thermal CTP "LT-1" was sold in 1998.
Purple Laser CTP
The progress of semiconductor lasers is remarkable. In 1999, Japan’s Nichia Chemical Industry Co., Ltd. released a semiconductor laser for the next-generation DVD that oscillates in the 410-nm region, becoming a hot topic.
Assuming that the sensitivity of the 410 nm photosensitive resin can be improved to 10 μJ/cm2 or less, and for a long-wave visible light sensitivity lower than 450 nm, the work performance under yellow safe light can be obtained while maintaining the maintenance cost. Cheap violet laser CTP. For the corresponding CTP of the inner cylinder type laser imager using a 5 mW ultraviolet laser, the sensitivity of the requirements is estimated using the following exposure conditions of the laser imager. The exposure condition of the laser imager is: 5 mW, and the ultraviolet laser source is The layout output; 0.5mW, CTP area: 1m2, laser scanning density of 2500dpi, rotating mirror rotation speed: 20000rpm, exposure time: the required sensitivity within 5 minutes is 7.5μJ/cm2, however, this Sensitivity has exceeded the theoretical ultimate sensitivity of photopolymer systems.
In the above data, for the photopolymerization system, the thermal decomposition of the radical generating agent slightly occurs at room temperature, and the active radical is captured based on the oxygen passing through the oxygen barrier layer provided on the photopolymerizable layer. Does not trigger dark reaction polymerization of acrylic monomers. On the other hand, in order to polymerize a photopolymerization system, it is necessary to generate free radicals that are required for the polymerization to overcome oxygen. This requires a minimum amount of light energy, based on the ingression of oxygen molecules into the speed; can calculate the lowest energy (ultimate sensitivity) of the initiator polymerization system. For example, free is the thermal decomposition rate of the generating agent at 25°C which is 8.2×10 10 mol ecules/cm 2sec (mol/cm 2 sec.), compared to the oxygen permeable rate of the 2 μm thick polyethylene waking layer. 1×1013 mole/cm2sec. Thus, it was ascertained that this photopolymerization system was stable at room temperature. In order for this system to meet, the required limit light energy, the oxygen transmission rate through the incoming oxygen molecules, can be expressed by the number of photons equivalent to 2.1×10 10 moles/cm 2 , obtaining 13 μJ/cm 2 .
In order to obtain sensitivity beyond this limit sensitivity, a new light-initiating technique has been developed (Double
Photopolymerization initiator of Amplified Photoinitiation (abbreviated as DAP technology).
This initiator is generated by the first and second sensitization mechanisms. That is, the sensitizing dye absorbs laser light extremely efficiently, its light energy is transmitted to the radical generating agent, and the first light sensitization mechanism that increases the decomposition efficiency of the radical generating agent, plus 1 radical occurring by this sensitization decomposition. Additional reactions with acrylic acid grasses lead to the occurrence of acrylic radicals, 2 which attack the sensitized pigments and free radicals by acrylic acid radicals, causing induced decomposition of these initiators, and thus the occurrence of parametric active radicals. 3 These reactive radicals attach to On the acrylic monomer, acrylic radicals reoccurred, and a chain reaction of 1 to 3 resulted in the decomposition of the initiator that greatly exceeded the quantum yield 1 and formed a second chemical sensitization mechanism.
In other words, the DAP is exhibited in a photoinitiator and refers to a sensitization initiation mechanism that utilizes the acceleration mechanisms of the first and second steps described above. Based on this DAP technology, Mitsubishi Chemical Corporation has finally succeeded in developing a violet laser CTP that exceeds a limit sensitivity of 10 μJ/cm2 or less. It was performed on Drupa 2000 using a laser-based photosensitive resin CTP (LV-1). It is impossible to realize the common sense of photosensitive resin CTP with 5mW laser.
Conclusion
Mitsubishi Chemical Corporation in Drupa 1995 has already introduced the laser imaging machine and CTP for the thermal CTP system. At that time, the new technology of laser plate making under the white lamp was noticeable. After 5 years, the laser imaging machine and Both CTPs are improved as the system improves production efficiency. Later, it developed into a printing press (DI printer) equipped with a thermal laser imager. Into the new on-demand printing market. Nowadays, it is the thermal CTP that is using its technical stage and looking forward to new developments.
Mitsubishi Chemical Corporation has also made efforts to develop the LTSC technology for the "LT-1" and recently sold the "LT-2" with a wider development latitude. The major issues of thermal CTP are such as the improvement of the laser imaging machine, including the improvement of the laser output of the laser imaging machine, and the photosensitive resin CTP that can be provided by most manufacturers. These issues must be solved. Caixing. However, it can be assumed that a cheap system can be constructed, especially now that European manufacturers are doing their best and it is estimated that they will soon be promoted from European and American currency markets.
Basic situation of thermal CTP and violet laser CTP
The photosensitive resin CTP for ultraviolet rays is a double-layered structure in which an oxygen protective layer is attached to the photopolymerizable layer. In contrast, the photosensitive layer of the thermosensitive CTP is a single layer. In addition, since it is a heat-sensitive recording means that generates heat using laser light, it is not easily influenced by light or scattering due to light, and faithful dot reproducibility is easily obtained. Since light reaction is not used, it is also possible under white light. Platemaking.
In addition, because the ultraviolet laser imager uses a small, inexpensive laser for second-generation DVDs, the maintenance cost of the laser setter can be greatly reduced by the maintenance cost of the laser setter. The thermal imager (Thermalsetter) has already been supplied by more than a dozen companies such as CreoScitex, Dainippon Screen, etc. The maintenance service is relatively considerate, and the degree of technical perfection meets various kinds of application and size specifications. In addition, Thermal CTP has been sold by many companies such as Aafa, Fuji Photo Film, KPG, etc., and it has become a mature and practical field. At present, it is being promoted at a double speed every year.
Since last year, the Violet setter has been published successively from seven European companies, all of which use low-output lasers of 5mW. However, there are not many manufacturers that supply the applicable CTP plates. It is estimated that there will be soon. An imaging machine loaded with a 30mW laser was introduced.
Key technologies of thermal CTP and violet laser CTP
Thermal CTP
Thermal CTP was released in 1995. The negative graph type is ahead of the positive graph type development. The negative graph type thermal sensitive CTP is due to the use of a photo-oxygen generating agent to cause a thermal polycondensation reaction, which requires heat after exposure, and thus is easy to image quality. Deviations were created. By 1997, new positive-type thermal CTPs that did not require such heating had finally been released and have now become mainstream.
This type of printing plate incorporates a near-infrared pigment in a binder polymer matrix. This pigment absorbs near-infrared light and undergoes thermal conversion so that the exposed part of the polymer matrix becomes soluble in a basic substance. Make a plate that forms a positive image. It is also possible to complete the laser plate-making work under white light without any photochemical reaction.
If the high-output thermal laser light is converged and then projected onto the CTP, it reaches a high temperature of about 100°C near the surface of the photosensitive layer of about 2 μm thick, but the photosensitive layer near the aluminum substrate having a high thermal conductivity is only about 500. °C, expressed as a relatively low temperature, there is a big gap between the two. For this reason, it is difficult to make development contrast. Thus, a polymer matrix structure with a high density can be formed near the control surface for different temperature distributions, and a physical and chemical method has been developed by Mitsubishi Chemical Corporation, namely, a photosensitive resin layer nanostructure control (Photpolymer Layer Nano). Structure Control (referred to as PNSC technology). Listed on the market since 1998, the development stability, surface strength, print resistance, and image quality are all excellent. Japan's original Thermal CTP "LT-1" was sold in 1998.
Purple Laser CTP
The progress of semiconductor lasers is remarkable. In 1999, Japan’s Nichia Chemical Industry Co., Ltd. released a semiconductor laser for the next-generation DVD that oscillates in the 410-nm region, becoming a hot topic.
Assuming that the sensitivity of the 410 nm photosensitive resin can be improved to 10 μJ/cm2 or less, and for a long-wave visible light sensitivity lower than 450 nm, the work performance under yellow safe light can be obtained while maintaining the maintenance cost. Cheap violet laser CTP. For the corresponding CTP of the inner cylinder type laser imager using a 5 mW ultraviolet laser, the sensitivity of the requirements is estimated using the following exposure conditions of the laser imager. The exposure condition of the laser imager is: 5 mW, and the ultraviolet laser source is The layout output; 0.5mW, CTP area: 1m2, laser scanning density of 2500dpi, rotating mirror rotation speed: 20000rpm, exposure time: the required sensitivity within 5 minutes is 7.5μJ/cm2, however, this Sensitivity has exceeded the theoretical ultimate sensitivity of photopolymer systems.
In the above data, for the photopolymerization system, the thermal decomposition of the radical generating agent slightly occurs at room temperature, and the active radical is captured based on the oxygen passing through the oxygen barrier layer provided on the photopolymerizable layer. Does not trigger dark reaction polymerization of acrylic monomers. On the other hand, in order to polymerize a photopolymerization system, it is necessary to generate free radicals that are required for the polymerization to overcome oxygen. This requires a minimum amount of light energy, based on the ingression of oxygen molecules into the speed; can calculate the lowest energy (ultimate sensitivity) of the initiator polymerization system. For example, free is the thermal decomposition rate of the generating agent at 25°C which is 8.2×10 10 mol ecules/cm 2sec (mol/cm 2 sec.), compared to the oxygen permeable rate of the 2 μm thick polyethylene waking layer. 1×1013 mole/cm2sec. Thus, it was ascertained that this photopolymerization system was stable at room temperature. In order for this system to meet, the required limit light energy, the oxygen transmission rate through the incoming oxygen molecules, can be expressed by the number of photons equivalent to 2.1×10 10 moles/cm 2 , obtaining 13 μJ/cm 2 .
In order to obtain sensitivity beyond this limit sensitivity, a new light-initiating technique has been developed (Double
Photopolymerization initiator of Amplified Photoinitiation (abbreviated as DAP technology).
This initiator is generated by the first and second sensitization mechanisms. That is, the sensitizing dye absorbs laser light extremely efficiently, its light energy is transmitted to the radical generating agent, and the first light sensitization mechanism that increases the decomposition efficiency of the radical generating agent, plus 1 radical occurring by this sensitization decomposition. Additional reactions with acrylic acid grasses lead to the occurrence of acrylic radicals, 2 which attack the sensitized pigments and free radicals by acrylic acid radicals, causing induced decomposition of these initiators, and thus the occurrence of parametric active radicals. 3 These reactive radicals attach to On the acrylic monomer, acrylic radicals reoccurred, and a chain reaction of 1 to 3 resulted in the decomposition of the initiator that greatly exceeded the quantum yield 1 and formed a second chemical sensitization mechanism.
In other words, the DAP is exhibited in a photoinitiator and refers to a sensitization initiation mechanism that utilizes the acceleration mechanisms of the first and second steps described above. Based on this DAP technology, Mitsubishi Chemical Corporation has finally succeeded in developing a violet laser CTP that exceeds a limit sensitivity of 10 μJ/cm2 or less. It was performed on Drupa 2000 using a laser-based photosensitive resin CTP (LV-1). It is impossible to realize the common sense of photosensitive resin CTP with 5mW laser.
Conclusion
Mitsubishi Chemical Corporation in Drupa 1995 has already introduced the laser imaging machine and CTP for the thermal CTP system. At that time, the new technology of laser plate making under the white lamp was noticeable. After 5 years, the laser imaging machine and Both CTPs are improved as the system improves production efficiency. Later, it developed into a printing press (DI printer) equipped with a thermal laser imager. Into the new on-demand printing market. Nowadays, it is the thermal CTP that is using its technical stage and looking forward to new developments.
Mitsubishi Chemical Corporation has also made efforts to develop the LTSC technology for the "LT-1" and recently sold the "LT-2" with a wider development latitude. The major issues of thermal CTP are such as the improvement of the laser imaging machine, including the improvement of the laser output of the laser imaging machine, and the photosensitive resin CTP that can be provided by most manufacturers. These issues must be solved. Caixing. However, it can be assumed that a cheap system can be constructed, especially now that European manufacturers are doing their best and it is estimated that they will soon be promoted from European and American currency markets.
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