Osaka Prefecture University　
SHIRAI Lab.

(Polymer Chemistry Research Group)

　　Address　　　　Staff　　　　Research Interest　　　Themes　　　　Recent Publications　　　Recent Books and Reviews



Address
　　　　Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University,
　　　　1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
　　　　Tel/Fax +81-72-254-9292

Staff　
　　　　Professor： Masamitsu Shirai (mshirai@)
　　　 Assistant Professor：Haruyuki Okamura (okamura@)
　 　　　　　　(please add "chem.osakafu-u.ac.jp" )
　

Research Interest

Our research interest is "Utilization of Light in Polymer Science". 　We are doing basic research to develop the highly functionalized photosensitive polymers. 　Our research includes synthesis of photosensitizers, monomers, and photo-reactive polymers and their applications to microelectronics, UV curing, and photochemical modification of polymer surfaces.

Themes

• Development of UV curing materials with environmentally friendly property.
• Mechanistic study of network formation in UV cured materials.
• Synthesis of photoacid generators and photobase generators and their applications to photosensitive materials.
• Development of EUV resists.
• Mechanistic study of acid diffusion in chemically amplified resist systems.
• Development of novel monomers for UV nanoimprint lithography.
• Photo-functionalization of solid polymer surface.

Recent Publications

"Photo-cross-linking and De-cross-linking of Modified Polystyrenes Having Degradable Linkages"
H. Okamura, E. Yamauchi, M. Shirai
React. Funct. Polym., 71, 480-488 (2011).

"Preparation of Replicated Resin Mold for UV Nanoimprint Using Reworkable Dimethacrylate"
D. Matsukawa, H. Okamura, M. Shirai
J. Photopolym. Sci. Technol., 23(6), 781-787 (2010).
"Novel Photo-cross-linkable Dendrimers Having Thermal De-cross-linking Properties"
H. Okamura, M. Shirai
Polymer, 51, 5087-5094 (2010).
"Chemical Recycling of Networked Polystyrene Derivatives Using Subcritical Water in the Presence of an Aminoalcohol"
K. Suyama, M. Kubota, M. Shirai, H. Yoshida
Polym. Degrad. Stabil., 95, 1588-1592 (2010).
"The Novel Photocurable Network: Urea-tetraacrylate/thiol System"
H. Matsushima, J. Shin, J. W. Chan, M. Shirai, C. E. Hoyle
J. Photopolym. Sci. Technol., 23(1), 121-124 (2010).
"Analysis of Chain Propagation in UV Curing Using Reworkable Resin"
D. Matsukawa, H. Okamura, M. Shirai
J. Photopolym. Sci. Technol., 23(1), 125-128 (2010).
"Photoreactivity of Mono-, Di-, and Trifunctional O-Acyloximes and Their Abilities to Crosslink Poly(glycidyl methacrylate)"
K. Suyama, S. Ogata, T. Inoue, M. Shirai
J. Photopolym. Sci. Technol., 23(3), 439-446(2010).
"Cyclic O-Acyloximes as Novel Photolatent Bases"
K. Suyama, T. Inoue, M. Shirai
Chem. Lett., 39(4), 362-363 (2010).
"Novel reworkable resins: thermo- and photo- curable di(meth) acrylates"
D. Matsukawa, H. Okamura, M. Shirai
Polym Int , 59, 263-268 (2010).

"Photo- and thermal curing of tri-functional methacrylate with degradable property"
H. Okamura, T. Terakawa, M. Shirai
Res. Chem. Intermediate, 35(8-9), 865-878 (2009).

"Non-Chemically Amplified EUV Resist Based on PHS"
M. Shirai, K. Maki, H. Okamura, K. Kaneyama, T. Itani
J. Photopolym. Sci. Technol., 22(1), 111-116 (2009).

"i-Line Sensitive Photoacid Generators Using Thianthrenium Derivatives"
H. Okamura, H. Naito, M. Shirai
J. Photopolym. Sci. Technol., 22(5), 583-586 (2009).

"Photocurable oligo(hemiacetal ester)s having methacrylate side chains"
D. Matsukawa, T. Mukai, H. Okamura, M. Shirai
Eur. Polym. J., 45, 2087-2095(2009).

"A UV curable resin with reworkable properties: application to imprint lithgraphy"
M. Matsukawa, H. Wakayama, K. Mitsukura, H. Okamura, Y. Hirai, M. Shirai
J. Mater. Chem., 19, 4085-4087(2009).

"Novel Resist for Replica Preparation of Mold for Imprint Lithography"
M. Matsukawa, H. Wakayama, K. Mitsukura, H. Okamura, Y. Hirai, M. Shirai
Proc. SPIE, 7273, 72730T1-10 (2009).

"Non-chemically Amplified Negative Resist for EUV Lithography"
M. Shirai, K. Maki, H. Okamura
Proc. SPIE, 7273, 72731N-1-8 (2009).

"Diffusion of Acid and Amine at Resist/BARC Interface"
M. Shirai, M. Majima, H. Okamura
Proc. SPIE, 7273, 727331-1-10 (2009).

"Enhanced Photochemical Generation of Amines from Trifunctional O-acyloxime"
K. Suyama, T. Inoue, M. Shirai
J. Photopolym. Sci. Technol.,21(2), 281-284 (2008).

"I-Line Sensitive Non-ionic Photoacid Generators Having Thianthrene Skeleton"
H. Okamura, H. Naito, M. Shirai
J. Photopolym. Sci. Technol.,21(2), 285-288 (2008).

"Non-Ionic Photoacid Generators for i-Line: Synthesis, Photochemistry, and Applications to Photocrosslinking System"
M. Shirai
Proc. RadTech UV & EB 2008 Technology EXPO & Conference, CDROM (2008).

"EUV Resist Based on Low Molecular Weight PHS"
M. Shirai, A. Kuroshima, H. Okamura, K. Kaneyama, T. Itani
Proc. SPIE, Vol. 6923, 6923441-692344-7, (2008).

"Chain Propagation in UV Curing of Di-(meth) acrylates"
M. Shirai, K. Mitsukura, H. Okamura
Chem. Mater., 20(5), 1971-1976 (2008).

"Chain-Propagation in Photopolymerization of Di-Functional Acrylate and Methacrylate Monomers"
M. Shirai, K. Mitsukura, H. Okamura
Proc. RadTech Europe 07., 1-6 (2007).

"Degradable Network Polymers Based on Di(meth)acrylates"
D. Matsukawa, H. Okamura, M. Shirai
Chem. Lett., 36(10), 1290-1291 (2007).

"Multifunctional epoxides with thermally degradable property - synthesis and photocrosslinking"
H. Okamura, K. Shin, M. Shirai
Proc. RadTech Asia ’07., 284-291(2007).

"Degradation of Crosslinked Unsaturated Polyesters by Using Sub-Critical Water"
K. Suyama, M. Kubota, M. Shirai, H. Yoshida
Polym. Prepri., 48(1), 572-573 (2007).

"Effect of Spacer Unit on Photo-Initiated Thermal Crosslinking of Polymers Having Carbamoyloxyimino Groups in Side-Chains"
K. Suyama, Y. Nakahara, M. Shirai
J. Photopolym. Sci. Technol., 20(6), 829-836 (2007).

"Non-ionic Photoacid Generator Sensitive to 365nm Light -Synthesis and Applications to Photocrosslinking Systems- "
M. Shirai
J. Photopolym. Sci. Technol., 20(5), 615-620 (2007).

"Generation of Amines by Using Photo-Triggred Thermal Deprotection "
T. Ohba, K. Kitamoto, D. Nakai, K. Suyama, M. Shirai
J. Photopolym. Sci. Technol., 20(2), 299-302 (2007).

"Organic Solvent-Free Reworkable Photocrosslinking System"
H. Okamura, Y. Tajima, T. Ohba, K. Suyama, M. Shirai
J. Photopolym. Sci. Technol., 20(2), 303-306 (2007).

"Properties and Lithographic Capability of Sulfonium Salts with Aromatic Cyclic Ketone Group for ArF Chemically Amplified Resist"
K. Maeda, K. Nakano, S. Iwasa, E. Hasegawa, M. Shirai
Jpn. J. Appl. Phys., 46(1), 111-114 (2007).

"Reworkable UV curing materials"
M. Shirai
Progress in Organic Coatings., 58, 158-165 (2007)

."Degradation of crossslinked unsaturated polyesters in sub-critical water "
K. Suyama, M. Kubota, M. Shirai, H. Yoshida
Polym. Degrad. Stabil., 92, 317-322(2007).

"Design and Lithographic Characteristics of Alicylic Fluoropolymer for ArF Chemically Amplified Resists"
K. Maeda, K. Nakano, M. Shirai
Jpn. J. Appl. Phys., 45(46), L1230-L1231 (2006).

"Low-Ea Chemical Amplification Resists for 193nm Lithography"
T. Ogata, S. Furuya, K. Kasai, H. Hada, M. Shirai
Jpn. J. Appl. Phys., 45(6B), 5450-5455 (2006).

"Photochemical formation of ammonium / thiolate complexes from quaternary ammonium thiocyanates and its use in crosslinking of polymers"
K. Suyama, K. Fuke, T. Yamamoto, Y. Kurokawa, M. Tsunooka, M. Shirai
J. Photochem. Photobiol. A: Chem., 179(1-2), 87-94 (2006).

" Quaternary Ammonium Salt as DBU-Generating Photobase Generator"
K. Suyama, H. Araki, M. Shirai
J. Photopolym. Sci. Technol., 19(1), 81-84 (2006).

" Visible Light-Induced Formation of Pendant Basic Groups by Using Triplet Sensitizers"
T. Ohba, K. Suyama, M. Shirai
React. Funct. Polym., 66(10), 1189-1197 (2006).

"Photocrosslinking of Oligomers Bearing Glycidyl Sulfonate Ester Units and Their Redissolution Property "
T. Ohba, K. Suyama, M. Shirai
J. Photopolym. Sci. Technol., 19(6), 709-712 (2006).

"Effect of alcohols on the degradation of crosslinked unsaturated polyester in subcritical water"
K. Suyama, M. Kubota, M. Shirai, H. Yoshida
Polym. Degrad. Stab., 91(4), 983-986 (2006).

"Reworkable Photocrosslinking System Using Multifunctional Epoxides and Photobase Generators"
H. Okamura, T. Terakawa, K. Suyama, M. Shirai
J. Photopolym. Sci. Technol., 19(1), 85-88 (2006).

"Photocrosslinking System Using Multifunctional Epoxy Crosslinkers Having Degradable Properties"
H. Okamura, K. Shin, M. Shirai
Polym. J., 38(12), 1237-1244 (2006).

" Epoxy-containing ArF resists with narrow molecular weight distribution
M.Shirai, M.Manabe, S.Tsuji, T.Itan
J. Vac. Sci. Technol. B 24(6) 3021-3024 (2006)

"Thermolysis of Polymethacrylates for 193 nm Resist"
T.Ogata, K.Kasai, S.Matsumaru, M.Takahashi, H.Hada, M.Shirai
J.Photopolym.Sci.Technol. 19(6), 705-708(2006)

" Design and Characteristics of Acrylate Polymers with Alicyclic Lactone Group for ArF resists
K.Maeda, K.Nakano, M.Shirai
J.Photopolym.Sci.Technol. 19(6), 699-703(2006)

"Thermally Stable Carbamates as Novel Photobase Generators
K. Suyama, S. Nakao, M. Shirai
J. Photopolym. Sci. Technol., 18(1), 141-148 (2005).

" Photocrosslinking and Thermal Degradation of Epoxy-containing Polymers Using Photobase Generators"
T. Ohba, D. Nakai, K. Suyama, M. Shirai
Chem. Lett., 34(6), 818-819 (2005).

" Synthesis and Dissolution Properties of ArF Resist with Well-defined Structure"
M. Shirai, K. Sakai, T. Koyanagi
J. Photopolym. Sci. Technol., 18(3), 389-392 (2005).

"Resist Characteristics of Acryl Polymer with Methyl Acetal Protecting Group for 193nm Lithography"
T. Ogata, S. Matsumaru, R. Takahashi, K. Kasai, Y. Kinoshita, H. Hada, M. Shirai
J. Photopolym. Sci. Technol., 18(3), 393-398 (2005).

"Highly Sensitive Photocrosslinking System Using Fluorene Derivatives Having Vinyl Ether or Epoxy Moiety",
H. Okamura, K. Mitsukura, M. Shirai, T. Fujiki, M. Yamada, S. Kawasaki
J. Photopolym. Sci. Technol., 18(2), 213-220 (2005).

"Polymeric Photobase Generator with a New Architecture: Comparison of Random and Block Copolymers Prepared by RAFT Polymerization Technique"
K. Suyama, D. Nakai, T. Ohba, M. Shirai
J. Photopolym. Sci. Technol., 18(6), 707-710 (2005).

"Highly Sensitive Photocrosslinking System Using Fluorene Derivatives Having Vinyl Ether or Epoxy Moiety"
H. Okamura, K. Mitsukura, M. Shirai, T. Fujiki, T.Yamada, S. Kawasaki
J. Photopolym. Sci. Technol., 18(2), 223-230 (2005).

"Multi-functional Methacrylates Bearing Thermal Degradation Properties - Synthesis, Photo- and Thermal Curing, and Thermolysis"
M. Shirai, K. Mitsukura, H. Okamura, M. Miyasaka
J. Photopolym. Sci. Technol., 18(2), 199-202 (2005).

" Synthesis of Photocrosslinkable Polymers Having Pendant Oxetane Groups and Their Dissolution in Water by Thermolysis"
H. Okamura, Y. Tajima, M. Shirai
J. Photopolym. Sci. Technol., 18(6), 715-718 (2005)

"Crosslinking of Oligomers Bearing Carbamoyloxyimino Groups with Their Photochemical and Thermal Reactions"
K. Suyama, H. Iriyama, M. Tsunooka, M. Shirai
J. Polym. Sci. Part A: Polym. Chem., 42(11), 2612-2620 (2004).

"Photocrosslinking System Using Multifunctional Epoxy Crosslinkers Having Thermally Degradable Properties"
H. Okamura, K. Shin, M. Tsunooka, M. Shirai
J. Polym. Sci. Part A: Polym. Chem., 42(15), 3685-3696 (2004).

"Photo-Crosslinking of Poly(glycidyl methacrylate) Using Di-functional Photobase Generators"
T. Ohba, D.Nakai, K. Suyama, M. Shirai
J. Photopolym. Sci. Technol., 17(1), 11-14 (2004).

" Effect of Anions on Photoreactivity and Stability of Quaternary Ammonium Salts as Photobase Generators"
K. Suyma, K. Fuke, M. Shirai
J. Photopolym. Sci. Technol., 17(1), 15-18 (2004).

"I-Line Sensitive Photoacid Generators Having Thianthrene Skeleton"
H. Okamura, R. Matsumori, M. Shirai
J. Photopolym. Sci. Technol., 17(1), 131-134 (2004).

"Effects of Protecting Group on Resist Characteristics of Acryl Polymers for 193 nm Lithography"
T. Ogata, S. Matsumaru, H. Shimizu, N. Kubota, H. Hada, M. Shirai
J. Photopolym. Sci. Technol., 17(4), 483-488 (2004).

"Acid Components in Outgassing from F2 Resists: A Study Using In-Situ QCM Technique"
M. Shirai, S. Takashiba, Y. Horiguchi, S. Irie, T. Itani
J. Photopolym. Sci. Technol., 17(4), 645-650 (2004).

"Thermally Crosslinkable- Decrosslinkable System Using Diepoxy Crosslinkers containing Sulfonate Ester Moiety"
Y. D. Shin, A. Kawaue, H. Okamura, M. Shirai
React. Funct. Polym., 61(2), 293-302 (2004).

"Thermally Degradable Novel Diepoxy Crosslinkers Containing Sulfonate Ester Groups for Photocrosslinking System"
Y. D. Shin, A. Kawaue, H. Okamura, M. Shirai
Polym. Degrad. Stabil., 86(1), 153-158 (2004).

"Synthesis of Novel Photo-cross-linkable Polymers with Redissolution Property"
M. Shirai, A. Kawaue, H. Okamura, M. Tsunooka
Polymer, 45(22), 7519-7527 (2004).

"Synthesis of novel C60-containing Polymers Based on Poly(vinyl phenol) and Their Photo-transformation Properties"
H. Okamura, T. Takemura, M. Tsunooka, M. Shirai
Polym. Bull, 52(6), 381-391 (2004).

"Positive Resist using Crosslinking and Decrosslinking Properties"
H. Okamura, K. Shin, M. Tsunooka, M. Shirai
J. Photopolym. Sci. Technol., 17(5), 699-706 (2004).

"Crosslinking of Oligomers Utilizing Sensitized Photoreaction at 366 nm and Thermal Decomposition of Pendant Carbamoyloxyimino Groups"
K. Suyama, H. Iriyama, M. Tsunooka, M. Shirai
J. Photopolym. Sci. Technol., 17(5), 707-712 (2004).

"F2 Resist Based on Methacrylonitrile / 2-Trifluoromethylacrylate Copolymers"
M. Shirai, S. Takashiba, M. Tsunooka,
J. Photopolym. Sci. Technol., 16(4), 545-548 (2003).

" Vacuum Ultraviolet (VUV)-Light-Induced Outgassing from Resist Polymers: A Study Using In Situ Quartz Crystal Microbalance (QCM) Technique"
M. Shirai, T Shinozuka, M. Tsunooka, T. Itani
Jpn. J. Appl. Phys., 42(6B), 3900-3904 (2003).

"Photocleavage Processes in an Iminosulfonate Derivative Usable as Photoacid in Resist"
J. Lalevee, X. Allonas, J. P. Fouassier, M. Shirai, M. Tsunooka
Chem. Lett., 32(2), 178-179 (2003).

"Photo-Cross-Linkable Polymers Having Degradable Properties on Heating"
M. Shirai, A. Kawaue, H. Okamura, M. Tsunooka
Chem. Mater., 15, 4075-4081 (2003).

"Base Generation by the Photolysis of an Amineimide with Triplet-sensitizers and Its Use for an Epoxide / Thiol Curing System"
S. Katogi, M. Yusa, M. Shirai, M. Tsunooka
Chem. Lett., 32(5), 418-419 (2003).

"Synthesis of i- and g-Line Sensitive Photoacid Generators and Their Application to Photopolymer Systems"
C. Iwashima, G. Imai, H. Okamura, M. Tsunooka, M. Shirai
J. Photopolym. Sci. Technol., 16(1), 91-96 (2003).

"Visible Light-Induced Cationic Polymerization of Epoxides Sensitized by Benzoquinonylsulfanyl Derivatives"
K. Suyama, W. Qu, M. Shirai, M. Tsunooka
Chem. Lett., 32(1), 92-93 (2003).

"Positive and Negative Tone Protein Patterning on a Photobase Generating Polymer"
J. Wright, E. Ivanova, D. Pham, L. Filipponi, A. Viezzoli, K. Suyama, M. Shirai, M. Tsunooka, D. V. Nicolau
Langmuir, 19(2), 446-452 (2003).

"Photo- and Thermochemical Behavior of Quaternary Ammonium Thiocyanates and Their Use as Crosslinkers"
K. Suyama, K. Fuke, M. Shirai, M. Tsunooka
J. Photopolym. Sci. Technol., 16(1), 83-86 (2003).

"I-Line Sensitive Photoacid Generators and Their Use for Photocrosslinking of Polysilane/diepoxyfluorene Blend"
H. Okamura, K. Sakai, M. Tsunooka, M. Shirai, T. Fujiki, S. Kawasaki, M. Yamada
J. Photopolym. Sci. Technol., 16(1), 87-90 (2003).

"Evaluation of Quantum Yields for Decomposition of i-Line Sensitive Photoacid Generators"
H. Okamura, K. Sakai, M. Tsunooka, M. Shirai
J. Photopolym. Sci. Technol., 16(5), 701-706 (2003).

Recent Books and Reviews

"Basics and Applications of Photopolymerization Reactions"
M. Shirai
Research Signpost, (2009).

"Polymer Degradation and Performance"
ACS Symposium Series 1004,American Chemical Society (2009)

" I-Line Sensitive photoacid generators for UV curing"
Progress in Organic Coatings 64, 175-181(2009)

"Photobase generators: Recent progress and aplication trend n polymer sysyems"
Progress in Polymer Science, 34, 194-209(2009)

"Polymer Durability and Radiation Effects"
ACS Symposium Series 978,American Chemical Society (2008)

"Development of Photoacid and Photobase Generators as the Key Materials for Novel
Photopolymers"
J. Photopolym. Sci. Technol., 19(1), 65-71 (2006).

"Photochemistry and UV Curing: New Trends 2006 "
Research Signpost, Kelela, India (2006)

"Polymers for Microelectronics and Nanoelecronics"
ACS Symposium Series No.874, American Chemical Society(2004)

"Advances in Imaging Materials and Processes"
Society of Plastics Engineers Mid-Hudson Section（2004）

"Photoinitiated Polymerization"
ACS Symposium Series No.847, American Chemical Society（2003）

Shirai. Lab. Top Page

Dept. Applied Chemistry