Two-photon absorbing polymerization method, two-photon absorbing optical recording material and two-photon absorbing optical recording method

1. A two-photon absorbing polymerization method comprising:

a first step of irradiating light on a composition comprising a free radical polymerizable compound capable of a two-photon absorption to form only a latent image; and a second step of exciting the latent image by an application of heat to cause a polymerization,

wherein as a two-photon absorbing compound, a cyanine dye, a merocyanine dye, an oxonol dye, a phthalocyanine dye or a compound represented by the following formula (1) is used:

wherein R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom or a substituent and some of R 1 , R 2 , R 3 and R 4 may combine with each other to form a ring; n and m each independently represents an integer of 0 to 4 and when n and m each is 2 or more, multiple R 1 s, R 2 s, R 3 s or R 4 s may be the same or different, provided that n and m are not 0 at the same time; and X 1 and X 2 each independently represents an aryl group, a heterocyclic group or a group represented by formula (2):

wherein R 5 represents a hydrogen atom or a substituent, R 6 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and Z 1 represents an atomic group for forming a 5- or 6-membered ring.

2. The two-photon absorbing polymerization method as claimed in claim 1 , wherein the cyanine dye is represented by the following formula (3), the merocyanine dye is represented by formula (4) and the oxonol dye is represented by formula (5):

wherein Za 1 , Za 2 and Za 3 each represents an atomic group for forming a 5- or 6-membered nitrogen-containing heterocyclic ring, Za 4 , Za 5 and Za 6 each represents an atomic group for forming a 5- or 6-membered ring, Ra 1 , Ra 2 and Ra 3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, Ma 1 to Ma 14 each independently represents a methine group which may have a substituent or may form a ring together with another methine group, na 1 , na 2 and na 3 each represents 0 or 1, ka 1 and ka 3 each represents an integer of 0 to 3, provided that when ka 1 is 2 or more, multiple Ma 3 s or Ma 4 s may be the same or different and when ka 3 is 2 or more, multiple Ma 12 s or Ma 13 s may be the same or different, ka 2 represents an integer of 0 to 8, provided that when ka 2 is 2 or more, multiple Ma 10 s or Ma 11 s may be the same or different, CI represents an ion for neutralizing the electric charge, and y represents a number necessary for the neutralization of electric charge.

3. A two-photon absorbing polymerization method comprising: a first step of irradiating light on a composition comprising a cationic or anionic polymerizable compound capable of a two-photon absorption to form only a latent image; and a second step of exciting the latent image by an irradiation of light to cause a polymerization,

wherein as a two-photon absorbing compound, a cyanine dye, a merocyanine dye, an oxonol dye, a phthalocyanine dye or a compound represented by the following formula (1) is used:

wherein R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom or a substituent and some of R 1 , R 2 , R 3 and R 4 may combine with each other to form a ring; n and m each independently represents an integer of 0 to 4 and when n and m each is 2 or more, multiple R 1 s, R 2 s, R 3 s or R 4 s may be the same or different, provided that n and m are not 0 at the same time; and X 1 and X 2 each independently represents an aryl group, a heterocyclic group or a group represented by formula (2):

wherein R 5 represents a hydrogen atom or a substituent, R 6 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and Z 1 represents an atomic group for forming a 5- or 6-membered ring.

4. The two-photon absorbing polymerization method as claimed in claim 3 , wherein the cyanine dye is represented by the following formula (3), the merocyanine dye is represented by formula (4) and the oxonol dye is represented by formula (5):

wherein Za 1 , Za 2 and Za 3 each represents an atomic group for forming a 5- or 6-membered nitrogen-containing heterocyclic ring, Za 4 , Za 5 and Za 6 each represents an atomic group for forming a 5- or 6-membered ring, Ra 1 , Ra 2 and Ra 3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, Ma 1 to Ma 14 each independently represents a methine group which may have a substituent or may form a ring together with another methine group, na 1 , na 2 and na 3 each represents 0 or 1, ka 2 and ka 3 each represents an integer of 0 to 3, provided that when ka 1 is 2 or more, multiple Ma 3 s or Ma 4 s may be the same or different and when ka 3 is 2 or more, multiple Ma 12 s or Ma 13 s may be the same or different, ka 2 represents an integer of 0 to 8, provided that when ka 2 is 2 or more, multiple Ma 10 s or Ma 11 s may be the same or different, CI represents an ion for neutralizing the electric charge, and y represents a number necessary for the neutralization of electric charge.

5. A two-photon absorbing optical recording method comprising:

a first step of forming a latent image of a color-forming material comprising a cationic or anionic polymerizable compound by a two-photon absorption; a second step of irradiating light on said latent image of a color-forming material to cause a polymerization based on a linear absorption of the color-forming material; and thereby forming difference in the refractive index to perform a recording,

wherein as a two-photon absorbing compound, a cyanine dye, a merocyanine dye, an oxonol dye, a phthalocyanine dye or a compound represented by the following formula (1) is used:

wherein R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom or a substituent and some of R 1 , R 2 , R 3 and R 4 may combine with each other to form a ring; n and m each independently represents an integer of 0 to 4 and when n and m each is 2 or more, multiple R 1 s, R 1 s, R 3 s or R 4 s may be the same or different, provided that n and m are not 0 at the same time; and X 1 and X 2 each independently represents an aryl group, a heterocyclic group or a group represented by formula (2):

wherein R 5 represents a hydrogen atom or a substituent, R 6 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and Z 1 represents an atomic group for forming a 5- or 6-membered ring.

6. The two-photon absorbing optical recording method as claimed in claim 5 , wherein in said second step, light is irradiated on said latent image of a color-forming material to cause a polymerization while self-sensitizing and self-amplifying based on a linear absorption of the color-forming material and thereby difference in the refractive index is formed to perform a recording.

7. The two-photon absorbing optical recording method as claimed in claim 5 , wherein the cyanine dye is represented by the following formula (3), the merocyanine dye is represented by formula (4) and the oxonol dye is represented by formula (5):

wherein Za 1 , Za 2 and Za 3 each represents an atomic group for forming a 5- or 6-membered nitrogen-containing heterocyclic ring, Za 4 , Za 5 and Za 6 each represents an atomic group for forming a 5- or 6-membered ring, Ra 1 , Ra 2 and Ra 3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, Ma 1 to Ma 14 each independently represents a methine group which may have a substituent or may form a ring together with another methine group, na 1 , na 2 and na 3 each represents 0 or 1, ka 1 and ka 3 each represents an integer of 0 to 3, provided that when ka 1 is 2 or more, multiple Ma 3 s or Ma 4 s may be the same or different and when ka 3 is 2 or more, multiple Ma 12 s or Ma 13 s may be the same or different, ka 2 represents an integer of 0 to 8, provided that when ka 2 is 2 or more, multiple Ma 10 s or Ma 11 s may be the same or different, CI represents an ion for neutralizing the electric charge, and y represents a number necessary for the neutralization of electric charge.

8. A two photon absorbing optical recording and reproduction method comprising: performing a recording by the first and second steps described in claim 5 ; then performing a reproduction by irradiating light on said recorded area and detecting the difference in reflectance attributable to the difference in refractive index.

9. A two-photon absorbing optical recording method comprising: a first step of forming a latent image of a color-forming material containing a cationic or anionic polymerizable compound by a two-photon absorption; a second step of irradiating light on said latent image of a color-forming material to cause a polymerization based on a linear absorption of the color-forming material; and thereby forming difference in the refractive index to perform a recording, wherein the recording is performed by using a two-photon absorbing optical recording material comprising:

1) a two-photon absorbing compound capable of undergoing a two-photon absorption to produce an excited state upon irradiation with light having a wavelength that is longer than the linear absorption band of the compound 1) itself and has a molar absorption coefficient of linear absorption of 10 or less;

2) a dye precursor having an absorption shifted to the longer wavelength side than in the original state by electron or energy transfer from said two-photon absorbing compound 1) in the excited state to become a color-forming material having an absorption in the wavelength region where the molar absorption coefficient of linear absorption in the two-photon absorbing compound 1) is 5,000 or less;

3) a polymerization initiator capable of initiating a polymerization of a polymerizable compound by electron or energy transfer from said two-photon absorbing compound 1) in the excited state;

4) a cationic or anionic polymerizable compound; and

5) a binder,

wherein said two-photon absorbing compound is a cyanine dye, a merocyanine dye, an oxonol dye, a phthalocyanine dye or a compound represented by the following formula (1):

wherein R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom or a substituent and some of R 1 , R 2 , R 3 and R 4 may combine with each other to form a ring; n and m each independently represents an integer of 0 to 4 and when n and m each is 2 or more, multiple R 1 s, R 2 s, R 3 s or R 4 s may be the same or different, provided that n and m are not 0 at the same time; and X 1 and X 2 each independently represents an aryl group, a heterocyclic group or a group represented by formula (2):

wherein R 5 represents a hydrogen atom or a substituent, R 6 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and Z 1 represents an atomic group for forming a 5- or 6-membered ring.

10. The two-photon absorbing optical recording method as claimed in claim 9 , wherein the wavelength of light for performing the formation of a latent image by two-photon absorption in the first step and the wavelength of light for causing a polymerization by the latent image in the second step are the same.

11. The two-photon absorbing optical recording method as claimed in claim 9 , wherein the wavelength of light for causing a polymerization by a latent image in the second step is shorter than the wavelength of light for performing the formation of the latent image by two-photon absorption in the first step, and is present in the wavelength region where the molar absorption coefficient of linear absorption in the two-photon absorbing compound is 5,000 or less.

12. The two-photon absorbing optical recording method as claimed in claim 9 , wherein the polymerizable compound and the binder have a difference in the refractive index, and the compositional ratio of the polymerizable compound and a polymerization reaction product thereof to the binder becomes non-uniform between the recorded area and the unrecorded area to enable a two-photon absorbing optical recording by utilizing a modulation of refractive index.

13. A two photon recording process and reproduction method comprising: performing a recording by using a two-photon absorbing polymerizable composition; then performing a reproduction by irradiating light on said recorded area and detecting the difference in reflectance attributable to the difference in refractive index,

wherein the two-photon absorbing polymerizable composition comprises a two-photon absorbing compound, a polymerization initiator, a cationic or anionic polymerizable compound and a binder, in which the two-photon absorbing polymerizable composition is capable of generating a three-dimensional modulation of refractive index as a result of photo-polymerization caused by non-resonant two-photon absorption, and said two-photon absorbing compound is a methine dye, a cyanine dye, a merocyanine dye, an oxonol dye, or a phthalocyanine dye.

14. The two photon recording process and reproduction method as claimed in claim 13 , wherein the cyanine dye is represented by the following formula (3), the merocyanine dye is represented by formula (4) and the oxonol dye is represented by formula (5):

wherein Za 1 , Za 2 and Za 3 each represents an atomic group for forming a 5- or 6-membered nitrogen-containing heterocyclic ring, Za 4 , Za 5 and Za 6 each represents an atomic group for forming a 5- or 6-membered ring, Ra 1 , Ra 2 and Ra 3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, Ma 1 to Ma 14 each independently represents a methine group which may have a substituent or may form a ring together with another methine group, na 1 , na 2 and na 3 each represents 0 or 1, ka 1 and ka 3 each represents an integer of 0 to 3, provided that when ka 1 is 2 or more, multiple Ma 3 s or Ma 4 s may be the same or different and when ka 3 is 2 or more, multiple Ma 12 s or Ma 13 s may be the same or different, ka 2 represents an integer of 0 to 8, provided that when ka 2 is 2 or more, multiple Ma 10 s or Ma 11 s may be the same or different, CI represents an ion for neutralizing the electric charge, and y represents a number necessary for the neutralization of electric charge.

15. A method for three-dimensionally modulating a refractive index, comprising: irradiating a two-photon absorbing polymerizable composition with laser light at a wavelength being longer than the linear absorption band of the two-photon absorbing compound and having no linear absorption to induce a two-photon absorption; and causing photopolymerization by utilizing the two-photon absorption induced,

wherein the two-photon absorbing polymerizable composition comprises a two-photon absorbing compound, a polymerization initiator, a cationic or anionic polymerizable compound and a binder, in which the two-photon absorbing polymerizable composition is capable of generating a three-dimensional modulation of refractive index as a result of photo-polymerization caused by non-resonant two-photon absorption, and said two-photon absorbing compound is a methine dye, a cyanine dye, a merocyanine dye, an oxonol dye, or a phthalocyanine dye.

16. A three-dimensional optical recording method comprising:

irradiating a two-photon absorbing polymerizable composition with laser light at a wavelength being longer than the linear absorption band of the two-photon absorbing compound and having no linear absorption to induce a two-photon absorption;

causing photopolymerization by utilizing the two-photon absorption induced to cause a non-uniformity of the compositional ratio of the polymerizable compound and a polymerization reaction product thereof to the binder between the laser-focused area and unfocused area; and

performing a recording by using a three-dimensional modulation of refractive index caused by the non-uniformity of the compositional ratio,

wherein the two-photon absorbing polymerizable composition comprises a two-photon absorbing compound, a polymerization initiator, a cationic or anionic polymerizable compound and a binder, in which the two-photon absorbing polymerizable composition is capable of generating a three-dimensional modulation of refractive index as a result of photo-polymerization caused by non-resonant two-photon absorption, and said two-photon absorbing compound is a methine dye, a cyanine dye, a merocyanine dye, an oxonol dye, or a phthalocyanine dye.