Optical information recording medium, method for producing same, and recording material

Abstract

An optical information recording medium, a method for manufacturing the same, and a recording material. The recording material includes a polymer compound and a photothermal agent. According to the molecular structure of the photo-thermal agent, carbon atoms and metal atoms form a conjugated heterocyclic structure, and an annular conjugated system absorbs optical signals with the wavelength ranging from 400 nm to 480 nm. The p orbits of the carbon atoms and the d orbits of the metal atoms can form a p-d conjugated system, and the p-d conjugated system absorbs optical signals with the wavelength ranging from 400 nm to 480 nm. In other words, the photo-thermal agent has an annular conjugated system and a p-d conjugated system, so that the photo-thermal agent can greatly absorb optical signals with the wavelength of 400-480 nm. Compared with the prior art, the optical information recording medium has the advantages that the optical information recording medium can greatly absorb optical signals with the wavelength ranging from 400 nm to 480 nm, the optical information recording medium can be compatible with a blue light reading system, in addition, the optical information recording medium can adopt the blue light reading system with small power to achieve information recording, and the storage cost of the optical information recording medium is low.

Description

Technical Field

[0001] The present application relates to the field of information storage technology, and in particular to an optical information recording medium and a preparation method and recording material thereof. Background Art

[0002] With the advent of the big data era, it is estimated that 60% of data storage in the future will be "cold data". Compared with other storage media, optical information recording media have become the mainstream cold data storage media due to their long life and low energy consumption.

[0003] The optical information recording medium may include: a substrate and a recording layer. As a key component in the optical information recording medium, the recording layer participates in recording information.

[0004] The material used in the recording layer may include: a polymer compound and a photothermal agent dispersed in the polymer compound. The photothermal agent can convert the absorbed recording light beam into thermal energy, which can cause the temperature of the recording layer to change. During the temperature change, the recording layer deforms to form a recording symbol, thereby realizing the recording of information. The photothermal agent disclosed in the related art has a low light absorption rate for the recording light beam. Summary of the invention

[0005] The present application discloses an optical information recording medium and a preparation method and recording material thereof. The recording material includes: a polymer compound and a photothermal agent. The molecular structure of the photothermal agent includes: a carbon atom and a metal atom form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital. The photothermal agent can produce a large absorption of light signals with a wavelength of 400nm-480nm.

[0006] The first aspect of the present application discloses a recording material, comprising: a polymer compound and a photothermal agent, wherein the molecular structure of the photothermal agent comprises: carbon atoms and metal atoms forming a conjugated heterocyclic structure, and the atomic orbital of the metal atom comprises a d orbital.

[0007] The recording material disclosed in the present implementation method includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure. The carbon atoms and metal atoms in the conjugated heterocyclic structure form a cyclic conjugated system, and the cyclic conjugated system absorbs light signals with a wavelength of 400nm-480nm. The atomic orbitals of carbon atoms include: p orbitals, and the atomic orbitals of metal atoms include d orbitals. The p orbitals of carbon atoms and the d orbitals of metal atoms can form a pd conjugated system, and the pd conjugated system absorbs light signals with a wavelength of 400nm-480nm. That is, the photothermal agent has a cyclic conjugated system and a pd conjugated system, and therefore, the photothermal agent can produce a greater absorption of light signals with a wavelength of 400nm-480nm.

[0008] The optical information recording medium formed by the recording material can produce a large absorption of light signals with a wavelength of 400nm-480nm. The optical information recording medium is compatible with a blue-ray reading system. In addition, the optical information recording medium can use a lower-power blue-ray reading system to achieve information recording, and the storage cost of the optical information recording medium is low.

[0009] In combination with a feasible implementation of the first aspect, the molecular structure of the photothermal agent includes:

[0010] At least one of; wherein, [M] is a unit containing or not containing a ligand centered on a metal atom M.

[0011] The molecular structure of the photothermal agent disclosed in the implementation method has a cyclic conjugated system and a PD conjugated system, and the photothermal agent can produce a large absorption of 400nm-480nm light signals. The optical information recording medium formed by the recording material containing the photothermal agent can be compatible with a blue-ray reading system. In addition, the optical information recording medium can use a blue-ray reading system with lower power to realize information recording, and the storage cost of the optical information recording medium is low.

[0012] In combination with a feasible implementation of the first aspect, the metal atom includes: at least one of a ruthenium atom Ru, a rhodium atom Rh, an osmium atom Os, and an iridium atom Ir.

[0013] In this implementation, the metal atom includes at least one of ruthenium atom Ru, rhodium atom Rh, osmium atom Os, and iridium atom Ir, and the atomic orbitals of the metal atoms have d orbitals. The d orbitals can form a pd conjugated system with the p orbitals of carbon atoms, and the pd conjugated system can further enhance the absorption of the recording material to the optical signal with a wavelength of 400nm-480nm.

[0014] In combination with a feasible implementation of the first aspect, the molar absorption coefficient of the photothermal agent for a light signal with a wavelength of 405 nm is greater than or equal to 1000 L·mol -1 cm -1 .

[0015] In the solution disclosed in the present implementation, the molar absorption coefficient of the photothermal agent to the recording light beam is greater than or equal to 1000 L·mol -1 cm -1 The photothermal agent can produce a large absorption of the recording light beam, that is, the photothermal agent has a high photothermal conversion efficiency. Therefore, the recording material disclosed in this implementation can use a small amount of photothermal agent. The photothermal agent has a small effect on the Tg of the recording material. Therefore, the recording material disclosed in this implementation has a higher Tg, that is, the recording material has a higher thermal stability.

[0016] In combination with a feasible implementation of the first aspect, the mass fraction of the photothermal agent is less than or equal to 20%, and the mass fraction of the photothermal agent is the mass ratio of the photothermal agent to the recording material.

[0017] In the recording material disclosed in the present implementation, the photothermal agent can generate a large absorption of light signals with a wavelength of 400nm-480nm, that is, the photothermal agent has a large photothermal conversion efficiency. The mass fraction of the photothermal agent in the recording material can be less than or equal to 20%, and the heat energy generated by the photothermal agent can still cause the polymer compound to undergo segmental motion.

[0018] The mass fraction of the photothermal agent in the recording material disclosed in this implementation can be less than 20%, and the photothermal agent has little effect on the Tg of the recording material. Therefore, the recording material disclosed in this implementation can have a higher Tg, that is, the recording material has higher thermal stability.

[0019] In combination with a feasible implementation of the first aspect, the melting point of the photothermal agent is greater than or equal to 200°C.

[0020] The melting point of the photothermal agent is higher than the Tg of the polymer compound, which can ensure that the photothermal agent still exists in a solid form during the information storage process, and the risk of diffusion of the photothermal agent is low. In this implementation, the melting point of the photothermal agent can be greater than or equal to 200°C. The photothermal agent has a higher melting point, and the recording material can use a polymer compound with a higher Tg, thereby ensuring that the recording material has a higher Tg.

[0021] In combination with a feasible implementation of the first aspect, the molar absorption coefficient of the photothermal agent for light signals with a wavelength of 650nm-750nm is less than or equal to 200L·mol -1 cm -1 .

[0022] In the recording material disclosed in the present implementation, the molar absorption coefficient of the photothermal agent for the optical signal (servo signal) with a wavelength of 650nm-750nm is less than or equal to 200L·mol -1 cm -1 , the photothermal agent has a small absorption on the servo signal. The optical information recording medium formed by the recording material can be well compatible with the servo system.

[0023] In combination with a feasible implementation of the first aspect, the glass transition temperature of the polymer compound is lower than the melting point of the photothermal agent.

[0024] During the information storage process, the temperature at the focus needs to be higher than the glass transition temperature (Tg) of the polymer compound to form a recording symbol. In this implementation, the melting point of the photothermal agent is higher than the Tg of the polymer compound, thereby ensuring that during the information storage process, the photothermal agent still exists in a solid form. Therefore, the risk of diffusion of the photothermal agent in the recording material disclosed in this implementation is low.

[0025] In combination with a feasible implementation of the first aspect, the glass transition temperature of the polymer compound is greater than or equal to 25°C.

[0026] In the present implementation, the glass transition temperature (Tg) of the polymer compound can be greater than or equal to 25°C, that is, the room temperature (20°C-25°C) is lower than the Tg of the polymer compound, that is, the polymer compound chain segments move very slowly at room temperature, and the polymer compound has greater rigidity at room temperature, thereby ensuring that the recording material containing the polymer compound can have a stable form at room temperature.

[0027] The second aspect of the present application discloses an optical information recording medium, comprising: a substrate and at least one recording layer, wherein the at least one recording layer is stacked on the substrate, and the recording layer adopts the recording material disclosed in the first aspect.

[0028] The optical information recording medium disclosed in the present implementation method includes: a substrate and at least one recording layer. The recording layer adopts a recording material. The recording material includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the cyclic conjugated system absorbs light signals with a wavelength of 400nm-480nm. The atomic orbitals of carbon atoms include: p orbitals, and the atomic orbitals of metal atoms include d orbitals. The p orbitals of carbon atoms and the d orbitals of metal atoms can form a pd conjugated system, and the pd conjugated system absorbs light signals with a wavelength of 400nm-480nm. That is, the photothermal agent has a cyclic conjugated system and a pd conjugated system, so the optical information recording medium can have a large absorption of light signals with a wavelength of 400nm-480nm. The optical information recording medium can use a low-power blue-ray reading system to store information, and the optical information recording medium can have good compatibility with the blue-ray reading system.

[0029] In combination with a feasible implementation of the second aspect, a light signal with a power of 100 mW and a wavelength of 405 nm irradiates the recording layer for 7.5 μs, and a recording symbol with a diameter greater than or equal to 98 nm is formed on the recording layer.

[0030] In the optical information recording medium disclosed in the present implementation, the recording layer can produce a large absorption of the light signal with a wavelength of 400nm-480nm. When the light signal of 100mW and a wavelength of 405nm irradiates the recording layer for 7.5μs, a recording symbol with a diameter greater than or equal to 98nm can be formed in the recording layer, that is, the optical information recording medium can have a faster information storage rate.

[0031] In combination with a feasible implementation of the second aspect, it further includes: an intermediate layer; the intermediate layer is stacked between adjacent recording layers, and the glass transition temperature of the intermediate layer is less than or equal to -50°C.

[0032] As a feasible implementation method, the glass transition temperature of the intermediate layer is less than or equal to -50°C. The room temperature is higher than the Tg of the intermediate layer, and the intermediate layer can undergo segmental motion at room temperature, that is, the intermediate layer has a smaller hardness at room temperature, and the intermediate layer has less resistance to forming recording symbols at room temperature, and the optical information recording medium has a larger information storage rate.

[0033] In combination with a feasible implementation of the second aspect, the recording symbol is set at the interface between the recording layer and the intermediate layer.

[0034] The third aspect of the present application discloses a method for preparing an optical information recording medium, comprising: forming a recording material, using the recording material to form at least one recording layer, and stacking the at least one recording layer on a substrate, wherein the recording material comprises: a polymer compound and a photothermal agent, and the molecular structure of the photothermal agent comprises: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbitals of the metal atoms include d orbitals.

[0035] The preparation method of the optical information recording medium disclosed in the present application adopts a recording material to form a recording layer. The recording material may include: a polymer compound and a photothermal agent. The molecular structure of the photothermal agent includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital. The photothermal agent has a cyclic conjugated system and a pd conjugated system, so the photothermal agent can produce a large absorption of light signals with a wavelength of 400nm-480nm. Correspondingly, the recording layer can produce a large absorption of light signals with a wavelength of 400nm-480nm. Therefore, the optical information recording medium obtained in the present application can use a low-power blue-ray reading system to realize information storage, and the optical information recording medium has a low storage cost.

[0036] In conjunction with a feasible implementation of the third aspect, the step of forming the recording material includes:

[0037] The polymer compound is heated so that the temperature of the polymer compound is higher than the glass transition temperature of the polymer compound; the polymer compound and the photothermal agent are mixed to obtain a recording material.

[0038] The method of forming the recording material disclosed in the present implementation has a simpler process and lower cost, so the preparation cost disclosed in the present implementation is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of an optical information recording medium is disclosed;

[0040] Figure 2 A flow chart of a method for preparing an optical information recording medium is disclosed;

[0041] Figure 3 The ultraviolet-visible absorption spectrum of the photothermal agent CL-1 disclosed in a feasible implementation method;

[0042] Figure 4 These are microscopic images of optical information recording medium I, optical information recording medium II, and optical information recording medium III.

[0043] In the figure:

[0044] 10-optical information recording medium, 11-substrate, 12-reflective layer, 13-recording layer, 14-intermediate layer, 15-cover layer, 16-hard coating layer. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0046] In the following, the terms "first", "second", etc. are used only for descriptive purposes to distinguish between identical or similar items with substantially identical functions and effects, and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0047] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0048] First, the concepts involved in the embodiments of the present application are explained:

[0049] Cold data can be understood as data that is not frequently accessed.

[0050] Blue light reading system is a device that can emit 400nm-480nm light signals.

[0051] Servo system, a device that can emit 600nm-750nm optical signals.

[0052] Blue light can be understood as an optical signal with a wavelength of 400nm-480nm. Blue light has a shorter wavelength and can be used to form recording symbols with smaller sizes inside optical information recording media.

[0053] Specific volume: the volume occupied by unit mass of a substance is called specific volume.

[0054] Glass transition temperature (Tg) refers to the temperature corresponding to the transition from glassy state to highly elastic state.

[0055] Photothermal agent is a substance that can convert light energy into thermal energy.

[0056] A conjugated heterocycle can be understood as a heterocycle with conjugated structural characteristics, and the atoms in the ring form a closed conjugated system.

[0057] Atomic orbitals, also known as orbital functions, are mathematical functions that describe the wave-like behavior of electrons in atoms. According to their shapes, atomic orbitals can be divided into: s orbitals, p orbitals, d orbitals, f orbitals, etc.

[0058] The pd conjugated system, also known as d orbital accepting conjugation, refers to a conjugated structure produced by the overlap of the p orbital of one atom and the d orbital of another atom.

[0059] An effective photothermal response can be understood as a function that enables an optical information recording medium to form a recording symbol.

[0060] The following is an explanation of the solutions involved in the embodiments of the present application:

[0061] With the advent of the big data era, it is estimated that 60% of data storage in the future will be "cold data". Compared with other storage media, optical information recording media have become the mainstream cold data storage media due to their long life and low energy consumption.

[0062] See also Figure 1 , the optical information recording medium 10 may include: a substrate 11 and a recording layer 13. In some feasible implementations, the optical information recording medium 10 may include: a layer of recording layer 13. In some feasible implementations, the optical information recording medium 10 may include: N layers of recording layers 13, wherein N is a positive integer greater than or equal to 2. The N layers of recording layers 13 are stacked on the substrate 11.

[0063] The optical information recording medium 10 may include: In the implementation of N recording layers 13, the optical information recording medium 10 further includes: a reflective layer 12. The reflective layer 12 is disposed between the recording layer 13 and the substrate 11. The reflective layer 12 is used to assist the servo system in positioning the recording layer 13.

[0064] Specific:

[0065] The servo signal (optical signal with a wavelength of 600nm-750nm) emitted by the servo system can reach the reflective layer 12 through the recording layer 13, and is reflected back to the servo system at the reflective layer 12. The servo system can locate the distance between the servo system and the reflective layer 12 based on the received servo signal, locate the predetermined position of the recording layer 13 by considering the distance between the servo system and the reflective layer 12 and the number of recording layers 13, thereby performing focusing control of the recording beam so that the recording beam is focused on a predetermined interface.

[0066] It is worth noting that Figure 1 The structure of the optical information recording medium 10 is merely an exemplary introduction. The structure of the optical information recording medium 10 does not constitute a specific limitation. In some feasible implementations, the optical information recording medium 10 may be Figure 1 The structure shown has more components. In some feasible implementations, the optical information recording medium 10 can be larger than Figure 1 The illustrated structure has fewer components.

[0067] The recording layer 13 is a key component in the optical information recording medium 10 and plays a major role in information recording. Specifically:

[0068] The recording layer 13 contains an absorption factor. The absorption factor is used to absorb the optical signal, so that the recording layer 13 can use the absorbed optical signal to form a recording symbol A related to the optical signal. The process of forming the recording symbol A can be understood as the process of information recording. Information recording can also be called information storage.

[0069] In the embodiment of the present application, the absorption factor can be understood as a substance that can respond to a light signal. The absorption factor can include but is not limited to: a photosensitizer, a photothermal agent, and the like.

[0070] The formation process of the recording symbol A is generally as follows: the light signal incident on the recording layer 13 is focused on the surface of the recording layer 13 or the interface between 13 and 14. The absorption factor near the focus can absorb more light signals, and when the absorbed light signal reaches a certain threshold, the recording symbol A is formed at the focus.

[0071] Please continue reading Figure 1The size of the record symbol A involved in the embodiment of the present application can be understood as the size of the record symbol A on the first plane, and the size of the record symbol A in the embodiment of the present application can also be referred to as the diameter of the record symbol A. The depth / height of the record symbol A involved in the embodiment of the present application can be understood as the depth / height H of the record symbol A in the stacking direction. Please refer to Figure 1 , the first plane is a plane perpendicular to the stacking direction B.

[0072] The depth of the recording symbol A can represent the stability of information recording. Specifically, the greater the depth of the recording symbol A, the better the stability of information recording on the optical information recording medium 10. The smaller the depth of the recording symbol A, the worse the stability of information recording on the optical information recording medium 10.

[0073] In addition, the size of the recording symbol A can represent the capacity of the optical information recording medium 10. Specifically: the larger the size of the recording symbol A, the fewer the number of recording symbols A that can be accommodated by the recording layer 13 per unit area, the smaller the storage density of the recording layer 13, and the smaller the capacity of the corresponding optical information recording medium 10. The smaller the size of the recording symbol A, the more the number of recording symbols A that can be accommodated by the recording layer 13 per unit area, the greater the storage density of the recording layer 13, and the larger the capacity of the corresponding optical information recording medium 10.

[0074] Generally, the size of the recording symbol A is related to the wavelength of the optical signal used in the information recording process. In the embodiment of the present application, the optical signal used in the information recording process can be referred to as a recording beam.

[0075] The size of the recording symbol A is related to the wavelength of the recording light beam. Specifically, the shorter the wavelength of the recording light beam, the smaller the size of the formed recording symbol A. The longer the wavelength of the recording light beam, the larger the size of the formed recording symbol A.

[0076] In order to obtain an optical information recording medium 10 with a larger capacity, a blue-ray reading system is generally used to form a recording symbol A. The blue-ray reading system can emit blue light with a shorter wavelength, and the blue light can form a recording symbol A of a small size in the recording layer 13 .

[0077] With the continuous development of the big data era, higher requirements are put forward for the capacity of the optical information recording medium 10, requiring the optical information recording medium 10 to have a larger capacity. Therefore, it is urgent to explore and develop a new generation of optical information recording media 10 with higher capacity to meet the growing demand for big data storage.

[0078] The capacity of the optical information recording medium 10 is related to two factors: (1) the storage density of a single recording layer 13; and (2) the number of recording layers 13 included in the optical information recording medium 10.

[0079] One way to increase the capacity of the optical information recording medium 10 is to increase the number of recording layers 13 in the optical information recording medium 10. For example, theoretically, by increasing the number of recording layers 13 of the optical information recording medium 10 from a single layer to several hundred layers, the capacity of the optical information recording medium 10 can be increased from 25 GB to 30 TB.

[0080] Generally, multiple recording layers 13 are stacked, which requires each recording layer 13 to have a high transmittance. In this way, during the information recording process, the optical signal can pass through the recording layer 13 near the side of the Blu-ray reading system to reach the recording layer 13 far from the side of the Blu-ray reading system, and form a recording symbol A on the surface of the recording layer 13.

[0081] The blue-ray reading system disclosed in the related art can only record information on the optical information recording medium 10 including 2-3 recording layers 13. One reason is that it is difficult to balance the high transmittance recording layer 13 required for building a multi-layer structure and the absorption factor of the high absorbance number required near the focus. Because the recording layer 13 needs to absorb a sufficient amount of light signal to form a recording symbol A.

[0082] In order to solve the above technical contradictions, the first related technology discloses a method for implementing the formation of recording symbols A by using the multi-photon absorption effect to increase the capacity of the optical information recording medium 10. Specifically:

[0083] The high-energy recording light beam is focused into the recording layer 13. Under the action of the strong light field, multiphoton absorption and avalanche ionization are induced in the recording layer 13, so that the recording layer 13 forms a high-temperature and high-pressure plasma in a relatively short time. Under the secondary action of the plasma, the shock wave and rarefaction wave formed inside the recording layer 13 trigger micro-explosions, and finally form a recording symbol A with a microporous structure inside the recording layer 13.

[0084] The above-mentioned implementation method of forming the recording symbol A by using the multi-photon absorption effect has the advantages of being simple, efficient, and highly universal, and can realize the writing of the recording symbol A in both the organic recording layer 13 and the inorganic recording layer 13. However, this writing method requires the use of a high-power ultra-short pulse laser, and a high-power ultra-short pulse laser (a specific blue-ray reading system) is expensive, making the storage cost per TB capacity of the optical information recording medium 10 relatively high.

[0085] Related technology 2 refers to the multi-layer film technology to prepare a multi-optical information recording medium 10 with a recording layer 13 and an intermediate layer 14 spaced apart. The advantage of this structure is that the recording beam will only respond to the recording layer 13, and the recording beam can directly pass through the intermediate layer, thereby reducing the loss of the recording beam in the intermediate layer 14.

[0086] In addition, in the solution disclosed in the related art 2, the recording layer 13 may include: photosensitizer. By selecting different photosensitizers, different optical recording mechanisms can be realized, the energy required for information recording can be reduced, and the use of expensive femtosecond lasers can be avoided. Specifically:

[0087] You can continue to read Figure 1 By selecting the photosensitizer, the recording layer 134 can respond to the first optical signal, and the recording layer 134 does not respond to the second optical signal. The recording layer 133 can respond to the second optical signal. The wavelength of the first optical signal and the wavelength of the second optical signal can be the same or different.

[0088] In the specific process of information recording: the first light signal can be focused in the recording layer 134, the first light signal excites the photosensitizer in the recording layer 134 to emit fluorescence, and the fluorescence is quenched to form a recording symbol A1.

[0089] The second optical signal may be focused in the recording layer 133 , and the second optical signal excites the photosensitizer in the recording layer 133 to emit fluorescence, and the recording symbol A2 is formed by quenching the fluorescence.

[0090] Since the recording layer 134 does not absorb the second optical signal, more second optical signals can pass through the recording layer 134 and be focused in the recording layer 133. That is, the solution disclosed in the related technology 2 can achieve high throughput and selective optical recording. The optical information recording medium 10 with this structure can form a recording symbol A based on quenching fluorescence under the action of a low-power fluorescence excitation optical path, thereby realizing multi-layer optical storage.

[0091] However, the solution disclosed in Related Art 2 has a drawback, which is that an additional fluorescence excitation light path is required.

[0092] Related Art 1: Forming the recording symbol A inside the recording layer 13 In addition to the method of forming the recording symbol A inside the recording layer 13 , the recording symbol A can also be formed on the interface between the recording layer 13 and the intermediate layer 14 .

[0093] Related technology 3 also discloses an optical information recording medium 10. The structure of the optical information recording medium 10 disclosed in related technology 3 can be further referred to. Figure 1 The optical information recording medium 10 may include: a recording layer 13 and an intermediate layer 14. The recording layer 13 may be made of materials including: a photothermal agent and a polymer compound.

[0094] The photothermal agent can convert the absorbed light signal into heat energy, which can change the temperature of the recording layer 13. During the temperature change of the recording layer 13, a recording symbol A can be formed on the interface between the recording layer 13 and the intermediate layer 14. The temperature change process may include a heating process and a cooling process. The heating process and the cooling process are described below respectively:

[0095] Heating process: When the recording light beam is focused on the interface between the recording layer 13 and the intermediate layer 14, the recording light beam can be absorbed by the photothermal agent in the recording layer 13, and the photothermal agent can convert the absorbed light energy into heat energy, so that the temperature at the focus increases. When the temperature is higher than the Tg of the polymer compound, the polymer compound undergoes segmental motion, the free volume of the polymer compound increases, and the recording layer 13 exhibits thermal expansion properties.

[0096] During the cooling process: after the light signal irradiation ends, the temperature of the recording layer 13 drops rapidly due to heat diffusion. The movement of the polymer chain segments slows down, the recording layer 13 expels free volume, and the specific volume of the recording layer 13 decreases linearly with the decrease in temperature.

[0097] As the temperature decreases, it becomes increasingly difficult for the chain segments to move. When the discharge of free volume “cannot keep up” with the rate of temperature drop, part of the free volume will remain inside the recording layer 13, causing the recording layer 13 to deform. The deformed recording layer 13 will drive the middle layer 14 to form a protruding point (recording symbol A), that is, the recording symbol A is located at the interface between the middle layer 14 and the recording layer 13.

[0098] In the above process, the process in which the photothermal agent converts the absorbed light energy into thermal energy can be called a photothermal response. The thermal energy converted by the photothermal agent can trigger the movement of polymer chain segments, and the response that finally forms the record symbol A can be called an effective photothermal response.

[0099] The optical information recording medium 10 disclosed in the related art 3 uses a light-to-heat conversion method to form a recording symbol A with a smaller size. Therefore, the optical information recording medium 10 of the related art 3 has a larger capacity. Compared with the solution disclosed in the related art 2 which requires an additional fluorescence excitation optical path, the solution disclosed in the related art 3 has better compatibility with the existing blue light reading system.

[0100] Unless otherwise specified, the optical information recording medium 10 involved in the subsequent embodiments refers to an optical information recording medium 10 that can form a recording symbol A by using a light-to-heat conversion method.

[0101] The recording layer 13 is a key component in the optical information recording medium 10 and is involved in recording information. The material used for the recording layer 13 is further described below.

[0102] The material used in the recording layer 13 may be referred to as a recording material in the embodiment of the present application. The recording material may include: a polymer compound and a photothermal agent. The recording material may be prepared by: physical doping and chemical bonding.

[0103] Chemical bonding can be understood as forming a chemical bond between the photothermal agent and the polymer compound through chemical bonding to obtain a recording material with a chemical bonding structure. The chemical bonding between the photothermal agent and the polymer compound can reduce the risk of diffusion of the photothermal agent. However, the process of forming chemical bonds greatly increases the complexity and cost of the recording material preparation process.

[0104] Relatively speaking, the process of forming recording materials by physical doping is simpler and has lower costs.

[0105] Physical doping requires that the photothermal agent have: high thermal stability (i.e. the photothermal agent has a high melting point), high molar absorptivity / absorbance for blue light, and high photothermal conversion efficiency. Specifically:

[0106] (1) The photothermal agent has high thermal stability.

[0107] During the information recording process, the heat energy generated by the photothermal agent needs to raise the temperature of the polymer compound to above the Tg of the polymer compound. In order to avoid the risk of diffusion of the photothermal agent, the photothermal agent should be in solid form, that is, the melting point of the photothermal agent needs to be higher than the Tg of the polymer compound. The above process needs to ensure that the melting point of the photothermal agent is higher than the Tg of the polymer compound.

[0108] Considering that the melting point of the photothermal agent determines the upper limit of the Tg of the polymer compound, the photothermal agent needs to have a higher melting point in order to use a polymer compound with a higher Tg.

[0109] The higher the Tg of the polymer compound, the higher the thermal stability of the recording material containing the polymer compound, and accordingly, the better the thermal stability of the recording layer 13 obtained from the recording material. The recording layer 13 with high thermal stability can achieve long-term storage stability of the recording symbol A.

[0110] (2) Photothermal agents have high photothermal conversion efficiency.

[0111] The photothermal agent can absorb the recording beam (light energy) emitted by the laser and convert the light energy into heat energy, so that the polymer compound can use the heat energy to form a recording symbol A. A necessary condition for forming a recording symbol A is that the photothermal agent generates enough heat energy to trigger the polymer compound to produce segmental motion and finally form a recording symbol A.

[0112] The heat energy generated by the photothermal agent is related to the photothermal conversion efficiency of the photothermal agent and the power of the laser. Specifically: if the photothermal agent has a high photothermal conversion efficiency, a laser with a lower power can be used to trigger the chain segment movement of the polymer compound.

[0113] As mentioned above, using a laser with lower power can reduce the storage cost of the optical information recording medium 10. Therefore, in order to achieve the purpose of reducing the storage cost of the optical information recording medium 10, a photothermal agent with higher photothermal conversion efficiency can be used.

[0114] In addition, the photothermal conversion efficiency of the photothermal agent affects the information storage rate of the optical information recording medium 10 formed by the recording material. Specifically, the higher the photothermal conversion efficiency of the photothermal agent, the greater the information storage rate of the optical information recording medium 10. The lower the photothermal conversion efficiency of the photothermal agent, the lower the information storage rate of the optical information recording medium 10.

[0115] (3) Photothermal agents have a higher molar absorption coefficient for blue light.

[0116] The photothermal conversion efficiency of the photothermal agent is related to the molar absorption coefficient of the photothermal agent to blue light. Specifically: the greater the molar absorption coefficient of the photothermal agent to blue light, the higher the photothermal conversion efficiency of the photothermal agent to blue light, and the lower the storage cost of the optical information recording medium 10 obtained in the end.

[0117] From the descriptions of (1), (2) and (3) above, it can be seen that in order to obtain an optical information recording medium 10 that has low storage cost, high thermal stability and high storage rate, the photothermal agent is usually required to have: high thermal stability, that is, the photothermal agent has a high melting point, a high molar absorption coefficient for blue light and a high photothermal conversion efficiency.

[0118] The related art discloses several recording materials, and the disclosed recording materials are:

[0119] Related technology 4: Benzotriazole derivatives are used as photothermal agents and mixed with polymer compounds to obtain recording materials. Benzotriazole derivatives can convert light energy into heat energy, and under the triggering of the heat energy, the polymer compound can undergo molecular chain segment movement to eventually form a recording symbol A.

[0120] The molar absorption coefficient / absorbance of benzotriazole derivatives at 405 nm is relatively low. In order to form the recording symbol A, generally, a relatively high content of benzotriazole derivatives needs to be doped into the polymer compound so that the recording material can form the recording symbol A by utilizing the absorbed light energy.

[0121] The molecular weight of the photothermal agent is smaller than that of the polymer compound. Usually, the Tg of the photothermal agent is lower than the Tg of the polymer compound. A high content of the photothermal agent doped in the polymer compound will reduce the Tg of the recording material, and the stability of the optical information recording medium 10 formed by the recording material is poor.

[0122] Related art 5 also discloses a recording material obtained by mixing phthalocyanines with polymer compounds. Phthalocyanine compounds have very strong absorption at 600nm-750nm, which results in the optical information recording medium containing phthalocyanines using a traditional semiconductor laser (also called a servo system) for tracking servo.

[0123] In order to solve the above technical problems, the embodiment of the present application discloses a recording material, which is used to form a recording layer of an optical information recording medium 10, and the recording material may include: a polymer compound and a photothermal agent. The molecular structure of the photothermal agent includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital.

[0124] The atoms (carbon atoms and metal atoms) in the conjugated heterocyclic structure form a cyclic conjugated system, which absorbs light signals with a wavelength of 400nm-480nm. The p orbital of the carbon atom and the d orbital of the metal atom can form a pd conjugated system, which absorbs light signals with a wavelength of 400nm-480nm. Visible photothermal agents have a cyclic conjugated system and a pd conjugated system, so they can absorb light signals with a wavelength of 400nm-480nm.

[0125] The optical information recording medium 10 formed by the recording material disclosed in the embodiment of the present application can produce greater absorption of light signals with a wavelength of 400nm-480nm, and the optical information recording medium 10 has a faster information storage rate. The optical information recording medium 10 can be compatible with a blue-ray reading system. In addition, the optical information recording medium 10 can use a blue-ray reading system with lower power to realize information recording, and the storage cost of the optical information recording medium 10 is low.

[0126] The following is a further description of the various components of the recording material;

[0127] The recording material disclosed in the embodiments of the present application includes: a polymer compound.

[0128] One of the functions of the polymer compound is to act as a binder to bind the components in the recording material together. Therefore, the polymer compound can also be called a polymer binder.

[0129] The embodiments of the present application do not specifically limit the types of polymer compounds. For example, the polymer compounds may include: polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), etc.

[0130] As the main component of the recording material, the Tg of the polymer compound has a great influence on the Tg of the recording material. The higher the Tg of the polymer compound, the higher the Tg of the recording material. The lower the Tg of the polymer compound, the lower the Tg of the recording material.

[0131] In order to obtain a recording material with a larger Tg, as a feasible implementation method, a polymer compound with a larger Tg can be used. Exemplarily, the polymer compound may include at least one of polyvinylacetate (PVAc) and polymethyl methacrylate (PMMA). Both PMMA and PVAc have a higher Tg, so that the recording material containing PMMA and PVAc has a higher Tg, that is, the recording material has better thermal stability.

[0132] In order to ensure that the recording layer formed by the recording material can have a self-supporting function at room temperature (20℃-25℃), as a feasible implementation method, the Tg of the polymer compound can be greater than or equal to 25℃, so that the polymer compound can have greater rigidity at room temperature, thereby ensuring that the recording material containing the polymer compound can have a stable form at room temperature.

[0133] In addition, during the information storage process, the temperature at the focus needs to be higher than the Tg of the polymer compound to form the recording symbol A. In this implementation, the melting point of the photothermal agent is higher than the Tg of the polymer compound, thereby ensuring that during the information storage process, the photothermal agent still exists in a solid form. Therefore, the risk of photothermal agent diffusion in the recording material disclosed in this implementation is low.

[0134] The recording material disclosed in the embodiment of the present application further includes: a photothermal agent, which can convert the absorbed recording light beam into thermal energy to trigger the segment movement of the polymer compound around it.

[0135] The molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital. As mentioned above, the photothermal agent has a cyclic conjugated system and a pd conjugated system, so the photothermal agent can produce a large absorption of the recording light beam.

[0136] Exemplarily, the molecular structure of the photothermal agent includes:

[0137] At least one of; wherein, [M] is a unit containing or not containing a ligand centered on a metal atom M.

[0138] The molecular structure of the photothermal agent disclosed in this implementation has a cyclic conjugated system and a pd conjugated system, so the photothermal agent can produce a large absorption of the recording light beam. The optical information recording medium 10 formed by the recording material disclosed in the embodiment of the present application can produce a large absorption of the light signal with a wavelength of 400nm-480nm.

[0139] As a feasible implementation method, the metal atom may include at least one of ruthenium atom Ru, rhodium atom Rh, osmium atom Os, and iridium atom Ir. The atomic orbitals of the above metal atoms have d orbitals. The d orbitals can form a pd conjugated system with the p orbitals of carbon atoms, and the pd conjugated system can further enhance the absorption of the recording material to the light signal with a wavelength of 400nm-480nm.

[0140] The photothermal agent disclosed in the present implementation can produce a large absorption of the recording light beam, that is, the photothermal agent has a large photothermal conversion efficiency. A small amount of photothermal agent can be used in the recording material, and the thermal energy generated by the photothermal agent can still trigger the chain segment movement of the polymer compound.

[0141] As mentioned above, the introduction of photothermal agent will reduce the Tg of the recording material. The recording material disclosed in this implementation can use a small amount of photothermal agent, and the photothermal agent has little effect on the Tg of the recording material. Therefore, the recording material disclosed in this implementation has a higher Tg, that is, the recording material has higher thermal stability.

[0142] As a feasible implementation, the mass fraction of the photothermal agent can be less than or equal to 20%. As mentioned above, the introduction of the photothermal agent will reduce the Tg of the recording material. In the recording material disclosed in this implementation, the mass fraction of the photothermal agent can be less than 20%, and the photothermal agent has little effect on the Tg of the recording material. Therefore, the recording material disclosed in this implementation has a higher Tg, that is, the recording material has a higher thermal stability.

[0143] In order to ensure that the optical information recording medium 10 formed by the recording material can achieve effective photothermal response, as a feasible implementation method, the mass fraction of the photothermal agent can be greater than or equal to 1%. The mass fraction of the photothermal agent involved in the embodiment of the present application can be understood as the mass ratio of the photothermal agent to the recording material.

[0144] As a feasible implementation method, the mass fraction of the photothermal agent can be 1%-20%.

[0145] As a feasible implementation, the melting point of the photothermal agent may be greater than or equal to 200° C. For example, the melting point of the photothermal agent may be 205° C., 210° C., and the like.

[0146] The melting point of the photothermal agent is higher than the Tg of the polymer compound, thereby ensuring that the photothermal agent still exists in a solid form during the information storage process. That is, when the melting point of the photothermal agent is higher than the Tg of the polymer compound, the risk of diffusion of the photothermal agent can be reduced.

[0147] In this implementation, the melting point of the photothermal agent can be greater than or equal to 200° C. The photothermal agent has a relatively high melting point, and the recording material can be a polymer compound with a relatively high Tg, thereby ensuring that the recording material has both a relatively high Tg and a relatively low risk of diffusion of the photothermal agent.

[0148] As a feasible implementation method, the molar absorption coefficient of the photothermal agent for the optical signal (recording light beam) with a wavelength of 400nm-480nm is greater than or equal to 1000L·mol -1 cm -1 For example, the molar absorption coefficient of the photothermal agent to the recording light beam may be: 2000 L·mol -1 cm -1 , 3000L·mol -1 cm -1 wait.

[0149] The recording material disclosed in this implementation method has a molar absorption coefficient of the photothermal agent to the recording light beam greater than or equal to 1000 L·mol -1 cm -1 The photothermal agent can generate a large absorption of the recording light beam, and the photothermal agent has a high photothermal conversion efficiency. Therefore, the recording material disclosed in the present implementation can use a small amount of photothermal agent to trigger the chain segment movement of the polymer compound, so the recording material disclosed in the present implementation can have a high thermal stability.

[0150] As a feasible implementation method, the molar absorption coefficient of the photothermal agent for the optical signal (servo signal) with a wavelength of 600nm-750nm is less than or equal to 200L·mol -1 cm -1 For example, the molar absorption coefficient of the photothermal agent for the servo signal may be: 30 L·mol -1 cm -1 , 50L·mol- 1 cm -1 wait.

[0151] As mentioned above, a necessary condition for the servo system to utilize the servo signal to assist in recording and reading the predetermined position of the recording layer 13 is that the recording layer has a small absorption of the servo signal.

[0152] The molar absorption coefficient of the photothermal agent for the servo signal in the recording material disclosed in the present implementation is less than or equal to 200 L·mol -1 cm-1 , the photothermal agent produces less absorption of the servo signal. The optical information recording medium 10 formed by the recording material can produce less absorption of the servo signal, and the servo signal emitted by the servo system can be used to assist in recording and reading the position of the recording layer 13. It can be seen that the optical information recording medium 10 formed by the recording material disclosed in this implementation can be well compatible with the servo system.

[0153] This completes the description of the recording material.

[0154] Please continue reading Figure 1 The embodiment of the present application also discloses an optical information recording medium 10 including: a substrate 11, at least one recording layer 13. At least one recording layer 13 is stacked on the substrate 11, and the recording layer 13 uses the recording material disclosed in the embodiment of the present application. The recording material may include: a polymer compound and a photothermal agent. The molecular structure of the photothermal agent includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital. The photothermal agent has a cyclic conjugated system and a pd conjugated system, so the photothermal agent can produce a large absorption of optical signals with a wavelength of 400nm-480nm. Correspondingly, the recording layer 13 can produce a large absorption of optical signals with a wavelength of 400nm-480nm. The optical information recording medium 10 can use a blue-ray reading system with low power to realize information storage, and the optical information recording medium 10 has a low storage cost. In addition, the optical information recording medium 10 can have good compatibility with the blue-ray reading system.

[0155] In the optical information recording medium 10 disclosed in the embodiment of the present application, the recording layer 13 can generate a large absorption of the optical signal with a wavelength of 400nm-480nm. It can be inferred that the optical information recording medium 10 can have a faster information storage rate.

[0156] For example, as a feasible implementation method, when a 100mW optical signal with a wavelength of 405nm irradiates the recording layer for 7.5μs, a recording symbol A with a diameter greater than or equal to 98nm can be formed on the recording layer. It can be seen that the optical information recording medium 10 disclosed in the embodiment of the present application can have a faster information storage rate. In addition, the optical information recording medium 10 disclosed in the embodiment of the present application can form a recording symbol A of 98nm, and the size of the recording symbol A is small, the optical information recording medium 10 can have a larger storage density, and the optical information recording medium 10 has a larger capacity.

[0157] The components of the optical information recording medium 10 are described below:

[0158] The substrate 11 is a supporting component for supporting the recording layer 13 and other layers. The present application embodiment does not specifically limit the material used for the substrate. As an example, the material used for the substrate 11 may include: polycarbonate.

[0159] The recording layer 13 is disposed on one side of the substrate 11. The material used for the recording layer 13 includes the recording material disclosed in the embodiment of the present application. The recording material may include: a polymer compound and a photothermal agent. When the recording layer 13 is irradiated with a recording beam, the photothermal agent absorbs the recording beam and generates heat energy, and the polymer compound undergoes segment movement under the action of the heat energy, and the recording layer 13 is deformed to form a recording symbol A.

[0160] The embodiment of the present application does not specifically limit the number of recording layers 13. In some feasible implementations, the number of recording layers 13 may be one. In order to increase the capacity of the optical information recording medium 10, in some feasible implementations, the number of recording layers 13 may be multiple.

[0161] In an implementation in which the optical information recording medium 10 includes N recording layers 13 , in order to achieve the purpose of recording and reading out the bits of a predetermined recording layer 13 , as a feasible implementation, the optical information recording medium 10 may further include a reflective layer 12 .

[0162] The reflective layer 12 is disposed between the substrate 11 and the recording layer 13 and is used to reflect the servo signal incident from one side of the recording layer 13 to the servo system, so that the servo system can locate the position of the recording layer 13 based on the reflected servo signal and N.

[0163] Please continue reading Figure 1 In the implementation of the optical information recording medium 10 including multiple recording layers 13, in order to prevent crosstalk between the multiple recording layers 13 (i.e., the phenomenon that a signal from one recording layer 13 is mixed with a signal from another adjacent recording layer 13), as a feasible implementation, the optical information recording medium 10 may further include: an intermediate layer 14. Please continue to refer to Figure 1 , the intermediate layer 14 can be arranged between adjacent recording layers 13. It is worth noting that the embodiment of the present application is only an exemplary introduction. The optical information recording medium 10 includes 4 recording layers (131, 132, 133, 134) and 4 intermediate layers (141, 142, 143, 144, 145). The number of recording layers 13 and the number of intermediate layers 14 do not constitute a specific limitation. In the actual application process, the number of recording layers 13 and the number of intermediate layers 14 can be set according to the needs.

[0164] In some feasible implementations, the record symbol A is located at the interface between the intermediate layer 14 and the recording layer 13, and the formation process of the record symbol A can be:

[0165] Please continue reading Figure 1 , the recording light beam can be focused on the interface between the recording layer 133 and the intermediate layer 144. The photothermal agent in the recording layer 133 absorbs the recording light beam and generates heat energy, triggering the polymer compound in the recording layer 133 to deform, causing the recording layer 133 to bulge, and the recording layer 133 drives the intermediate layer 144 to bulge, and finally forming a recording symbol A at the interface between the recording layer 133 and the intermediate layer 144.

[0166] In the implementation mode where the recording symbol A is located at the interface between the recording layer 133 and the intermediate layer 144 , during the process of forming the recording symbol A, the recording layer 133 drives the intermediate layer 144 to protrude in a direction away from the substrate 11 to form the recording symbol A.

[0167] The hardness of the intermediate layer 14 will have a certain influence on the formation of the recording symbol A. Specifically, the greater the hardness of the intermediate layer 14, the greater the resistance that needs to be overcome in the process of forming the recording symbol A, the longer the time required to form the recording symbol A, and the lower the information storage rate of the optical information recording medium 10. The lower the hardness of the intermediate layer 14, the smaller the resistance that needs to be overcome in the process of forming the recording symbol A, the longer the time required to form the recording symbol A, and the higher the information storage rate of the optical information recording medium 10.

[0168] In order to obtain an optical information recording medium 10 with a higher information storage rate, as a feasible implementation, the hardness of the intermediate layer 14 can be less than or equal to the hardness of the recording layer 13. In this implementation, the hardness of the intermediate layer 14 can be less than or equal to the hardness of the recording layer 13. The intermediate layer 14 has a smaller hardness, and the intermediate layer 14 has a smaller resistance to the formation of the recording symbol A, and the optical information recording medium 10 has a higher information storage rate.

[0169] As a feasible implementation, the glass transition temperature of the intermediate layer 14 is less than or equal to -50°C. The room temperature is higher than the Tg of the intermediate layer 14. The intermediate layer 14 can undergo segmental motion at room temperature, that is, the intermediate layer 14 has a smaller hardness at room temperature, and the intermediate layer 14 has a smaller resistance to forming the recording symbol A at room temperature, and the optical information recording medium 10 has a larger information storage rate.

[0170] It is considered that the storage cost of the optical information recording medium 10 is related to the recording beam loss of the recording beam. Specifically, the greater the recording beam loss, the higher the storage cost of the optical information recording medium 10; the smaller the recording beam loss, the lower the storage cost of the optical information recording medium 10.

[0171] In addition, the capacity of the optical information recording medium 10 is related to the recording beam loss of the recording beam. Specifically, the greater the recording beam loss, the more recording layers the optical information recording medium 10 can have, and the greater the capacity of the optical information recording medium 10. The smaller the recording beam loss, the fewer recording layers the optical information recording medium 10 can have, and the smaller the capacity of the optical information recording medium 10.

[0172] One source of recording beam loss includes absorption of the recording beam by the intermediate layer 14 .

[0173] In order to reduce the loss of the recording beam, as a feasible implementation method, the intermediate layer 14 is made of a material that does not react with the recording beam, thereby reducing the absorption of the recording beam by the intermediate layer 14 and reducing the loss of the recording beam, so that the optical information recording medium 10 has both a larger capacity and a lower storage cost.

[0174] For example, in some feasible implementations, the intermediate layer 14 may be made of a transparent material. The transparency involved in the embodiment of the present application may be understood as an absorption rate equal to or less than 1%.

[0175] The absorption rate of the intermediate layer 14 of the optical information recording medium 10 disclosed in the present implementation to the recording light beam is equal to or less than 1%, that is, the intermediate layer 14 produces less absorption to the recording light beam, and the recording light beam loss is less, so that the optical information recording medium 10 has both larger capacity and lower storage cost.

[0176] Another source of recording beam loss includes: reflection of the recording beam at the interface between the recording layer 13 and the intermediate layer 14. Specifically:

[0177] If the refractive index of the intermediate layer 14 is different from that of the recording layer 13, when the recording beam is emitted from the intermediate layer 14 to the recording layer 13, it may be reflected at the interface between the intermediate layer 14 and the recording layer 13, so that part of the recording beam returns to the intermediate layer 14 and causes recording beam loss.

[0178] In order to reduce the loss of the recording beam, as a feasible implementation method, the refractive index of the intermediate layer 14 can be adjusted to reduce the reflection of the recording beam at the interface between the recording layer 13 and the intermediate layer 14, so that the optical information recording medium 10 has both a larger capacity and a lower storage cost.

[0179] For example, the material that can be used as the intermediate layer 14 can be adjusted. For example, in the implementation method of using a resin in the intermediate layer 14, the polymerization degree of the resin can be adjusted to adjust the refractive index of the intermediate layer 14.

[0180] For example, a material that can be used as the intermediate layer 14 may be optionally added, or a refractive index matching material (inorganic fine particles, etc.) may be added to adjust the refractive index of the intermediate layer 14 .

[0181] As a feasible implementation method, the refractive index of the intermediate layer 14 can be equal to the refractive index of the recording layer 13. When the recording light beam is emitted from the intermediate layer 14 to the recording layer 13, it may directly pass through the interface between the intermediate layer 14 and the recording layer 13 (that is, no reflection occurs), thereby reducing the loss of the recording light beam, so that the optical information recording medium 10 has both a larger capacity and a lower storage cost.

[0182] As a feasible implementation, the optical information recording medium 10 may further include: a cover layer 15. The cover layer 15 is disposed on the side of the recording layer 13 / intermediate layer 14 away from the substrate 11, and plays a role in protecting the recording layer 13 / intermediate layer 14. The cover layer 15 is made of a material that allows the recording beam and the servo beam to pass through. The thickness of the cover layer 15 can be set according to requirements. For example, the cover layer 15 has an appropriate thickness ranging from tens of micrometers to several millimeters.

[0183] As a feasible implementation, the optical information recording medium 10 may further include: a hard coating layer 16, which may be disposed on the side of the cover layer 15 away from the base, and the hardness of the hard coating layer 16 is greater than the hardness of the cover layer 15, and plays a role in protecting the cover layer 15. The hard coating layer 16 is made of a material that allows the recording beam and the servo beam to pass through. The thickness of the hard coating layer 16 can be set according to requirements, and illustratively, the hard coating layer 16 has an appropriate thickness ranging from tens of microns to several millimeters.

[0184] This completes the description of the optical information recording medium.

[0185] The present application also discloses a method for preparing an optical information recording medium. Figure 2 , the preparation method may include:

[0186] S201: Forming a recording material.

[0187] The recording material may include: a polymer compound and a photothermal agent disclosed in the embodiments of the present application. The present invention does not limit the synthesis of the photothermal agent, and a disclosed method may be used, for example: a method for synthesizing a photothermal agent disclosed in "Study on the olefination of carbon dragon complexes" (Xia Haiping et al., Organic Chemistry, 2017, 37, 1181).

[0188] The embodiment of the present application does not specifically limit the method of forming the recording material. As a feasible method, the recording material can be formed by chemical bonding.

[0189] As a feasible method, the recording material can be formed by physical doping, specifically: heating the polymer compound so that the temperature of the polymer compound is higher than the glass transition temperature of the polymer compound; mixing the polymer compound and the photothermal agent to obtain the recording material. The above-mentioned method for forming the recording material has a simpler process and lower cost. Therefore, the preparation cost of the preparation method disclosed in this implementation method is low.

[0190] S202: Form at least one recording layer using a recording material, and the at least one recording layer is stacked on a substrate.

[0191] The embodiment of the present application does not specifically limit the implementation method of forming the recording layer. For example, at least one recording layer 13 can be prepared by spin coating followed by lamination, or micro-nano multi-layer co-extrusion.

[0192] The preparation method of the optical information recording medium disclosed in the embodiment of the present application adopts a recording material to form a recording layer. The recording material may include: a polymer compound and a photothermal agent. The molecular structure of the photothermal agent includes: a photothermal agent, and the molecular structure of the photothermal agent includes: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom includes a d orbital. The photothermal agent has a cyclic conjugated system and a pd conjugated system, so the photothermal agent can produce a large absorption of light signals with a wavelength of 400nm-480nm. Correspondingly, the recording layer 13 can produce a large absorption of light signals with a wavelength of 400nm-480nm. Therefore, the optical information recording medium 10 obtained in the embodiment of the present application can use a low-power blue-ray reading system to realize information recording, and the optical information recording medium 10 has a low storage cost.

[0193] The scheme disclosed in the embodiment of the present application is further described below in conjunction with specific embodiments:

[0194] Embodiment 1:

[0195] The present application embodiment specifically discloses a recording material I, and the molecular structure of the recording material I is as follows:

[0196]

[0197] It can be seen that the recording material I includes: PVAc and photothermal agent CL-1. The relative molecular weight (MW) of PVAc is 50000-80000. The Tg of PVAc is 33°C-45°C. The mass fraction of photothermal agent CL-1 in the recording material I is 1.14%.

[0198] As mentioned above, the photothermal agent CL-1 has a cyclic conjugated system and a pd conjugated system. Therefore, the photothermal agent can produce a large absorption of light signals with a wavelength of 400nm-480nm.

[0199] For details, please refer to Figure 3 , Figure 3 This is the UV-visible absorption spectrum of the photothermal agent CL-1. Figure 3 The horizontal axis is the wavelength of the recording beam, and the vertical axis is the molar absorption coefficient of the photothermal agent CL-1 to the recording beam. It can be seen that the molar absorption coefficient of the photothermal agent CL-1 to the light signal (recording beam) with a wavelength of 405nm can reach 2992.8L·mol -1 cm -1 Above. From Figure 3 The published results show that the photothermal agent CL-1 can produce a large absorption of light signals with a wavelength of 400nm-480nm.

[0200] The recording material II disclosed in Example 2 has similar components to the recording material I. The difference is that the mass fraction of the photothermal agent CL-1 in the recording material II is 1.75%.

[0201] The recording material III disclosed in Example 3 has similar components to the recording material I. The difference is that the mass fraction of the photothermal agent CL-1 in the recording material III is 2.58%.

[0202] The absorbance at 405nm of recording material I, recording material II and recording material III, the Tg of the polymer compound, the melting point of the photothermal agent, and the test results can be found in Table 1:

[0203] The absorbance of recording material I, recording material II, and recording material III at 405 nm can be tested by using an ultraviolet spectrophotometer.

[0204] The Tg of a polymer compound can be tested by conventional means in the art.

[0205] The melting point of the photothermal agent can be tested by differential scanning calorimetry (DSC). The specific test process is: nitrogen atmosphere, the mass of the photothermal agent is about 5mg-10mg, the nitrogen flow rate is 50ml / min, the heating rate is 15℃ / min, the test temperature range is 20℃-300℃, and the absorption / exothermic curve of the photothermal agent is recorded during the whole process. The melting point of the photothermal agent is obtained according to the absorption / exothermic curve of the photothermal agent.

[0206] Table 1

[0207]

[0208] It can be seen from the data in Table 1 that in Examples 1 to 3, the Tg of the polymer compound is lower than the melting point of the photothermal agent.

[0209] The absorbance of the recording materials disclosed in Example 1, Example 2, and Example 3 to 405nm light signals can reach above 4.99%, that is, recording materials I, II, and III can produce greater absorption to light signals with wavelengths between 400nm and 480nm.

[0210] The following experimental results are shown in Table 2 for information storage on optical information recording medium I formed by recording material I, optical information recording medium II formed by recording material II, and optical information recording medium III formed by recording material III.

[0211] The information storage process is as follows: a 405nm continuous laser (semiconductor continuous laser, objective lens numerical aperture of 0.8) is used to dot-array store the thin film sample. The morphology of the recorded symbol is characterized by an atomic force microscope, using an RTPSE probe, dynamic mode, scanning range of 10μm, and scanning frequency of 1Hz.

[0212] Table 2

[0213]

[0214]

[0215] The present application also collects microscopic images of optical information recording medium I, optical information recording medium II, and optical information recording medium III after information recording. The experimental results can be found in Figure 4 .

[0216] Figure 4 (A) in the figure is the result after the optical information recording medium I is irradiated with a recording beam signal with a pulse width of 50μs and a power of 70mW.

[0217] Figure 4 (ii) in the figure is the result after the optical information recording medium II is irradiated with a recording beam signal with a pulse width of 25μs and a power of 110mW.

[0218] Figure 4 (iii) in the figure is the result after the optical information recording medium I is irradiated with a recording beam signal with a pulse width of 7.5μs and a power of 120mW.

[0219] From Table 1, Table 2 and Figure 4 The published results show that:

[0220] The comparative example could not form the record symbol A.

[0221] The optical information recording medium I, the optical information recording medium II, and the optical information recording medium III can all form recording symbols.

[0222] Comparison of the recording time (pulse width) of Examples 1 to 3 shows that the higher the content of the photothermal agent, the shorter the time required to form a recording symbol and the faster the recording speed. In addition, the higher the content of the photothermal agent, the smaller the diameter of the recording symbol, which is conducive to higher capacity data storage.

[0223] In Example 3, when recording at a power of 100 mW and a pulse width of 7.5 μs, the diameter of the recorded symbol formed can reach 98 nm, and the optical information recording medium has a high storage density and capacity.

[0224] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0225] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A recording material, characterized in that: include: polymer compounds; A photothermal agent, wherein the molecular structure of the photothermal agent comprises: carbon atoms and metal atoms form a conjugated heterocyclic structure, and the atomic orbital of the metal atom comprises a d orbital.

2. The recording material according to claim 1, characterized in that The molecular structure of the photothermal agent includes: At least one of; Here, [M] is a unit centered on a metal atom M and containing or not containing a ligand.

3. The recording material according to claim 1 or 2, characterized in that The metal atom includes at least one of a ruthenium atom Ru, a rhodium atom Rh, an osmium atom Os, and an iridium atom Ir.

4. The recording material according to any one of claims 1 to 3, characterized in that: The molar absorption coefficient of the photothermal agent for the light signal with a wavelength of 405 nm is greater than or equal to 1000 L·mol -1 cm -1 .

5. The recording material according to any one of claims 1 to 4, characterized in that: The mass fraction of the photothermal agent is less than or equal to 20%, and the mass fraction of the photothermal agent is the mass ratio of the photothermal agent to the recording material.

6. The recording material according to any one of claims 1 to 5, characterized in that: The melting point of the photothermal agent is greater than or equal to 200°C.

7. The recording material according to any one of claims 1 to 6, characterized in that: The molar absorption coefficient of the photothermal agent for light signals with a wavelength of 650nm-750nm is less than or equal to 200L·mol -1 cm -1 .

8. The recording material according to any one of claims 1 to 7, characterized in that: The glass transition temperature of the polymer compound is lower than the melting point of the photothermal agent.

9. The recording material according to any one of claims 1 to 8, characterized in that: The glass transition temperature of the polymer compound is greater than or equal to 25°C.

10. An optical information recording medium, characterized in that: include: substrate; At least one recording layer is stacked on the substrate, and the recording layer is made of the recording material according to any one of claims 1 to 9.

11. The optical information recording medium according to claim 10, characterized in that The recording layer is irradiated with an optical signal at 100 mW and a wavelength of 405 nm for 7.5 μs, and a recording symbol having a diameter greater than or equal to 98 nm is formed on the recording layer.

12. The optical information recording medium according to claim 10 or 11, characterized in that: Also includes: Middle layer; The intermediate layer is stacked between the adjacent recording layers, and the glass transition temperature of the intermediate layer is less than or equal to -50°C.

13. The optical information recording medium according to claim 12, characterized in that The recording symbol is provided at the interface between the recording layer and the intermediate layer.

14. A method for preparing an optical information recording medium, characterized in that: include: forming a recording material, the recording material comprising: a polymer compound and a photothermal agent, the molecular structure of the photothermal agent comprising: a conjugated heterocyclic structure formed by carbon atoms and metal atoms, the atomic orbital of the metal atom comprising a d orbital; At least one recording layer is formed using the recording material, and the at least one recording layer is stacked on the substrate.

15. The preparation method according to claim 14, characterized in that: The step of forming the recording material comprises: Heating the polymer compound so that the temperature of the polymer compound is higher than the glass transition temperature of the polymer compound; The polymer compound and the photothermal agent are mixed to obtain a recording material.

Images