JPS6174891A - Optical recording method - Google Patents

Abstract

PURPOSE:To enhance sensitivity and a S/N ratio and to reduce an error rate by improving a surface layer, in performing optical recording by irradiating writing light to form a pit, by forming the pit as a recessed part in such a state that surface layer is not substantially destructed. CONSTITUTION:A surface layer is formed of a hard film with high m.p. so as not to form a pit by light irradiated for a definite time or less. In providing the surface layer with high m.p., by adjusting the intensity of writing light, a pulse width and a rotary speed, a pit recessed part is formed in such a state that the surface layer is substantially continuous and not substantially destructed. Therefore, the lowering in a S/N ratio based on the scattering of the crushed piece of the surface layer or the rising in an error rate is prevented while high sensitivity is kept.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Background Technical Field of the Invention The present invention relates to an optical recording method, particularly to an optical recording method for a heat mode optical recording medium.

Prior art optical recording media have the characteristic that the writing and reading media are not in contact with each other, so that the recording media do not deteriorate due to wear. For this reason, research and development of various optical recording media are being carried out.

Among such optical recording T2 media, heat mode optical recording media are being actively developed because they do not require development in a dark room.

This heat mode optical recording medium is an optical recording medium that uses recording light as heat. For example, a part of the medium is melted by IW, removed, etc. with recording light such as a laser, and is called a bit. Form a small hole and 1! There is a bit forming type in which information is recorded using the bits, and the bits are detected with readout light and read out.

Most of these types of media, especially those using a semiconductor laser as a light source that allows for miniaturization of the device, have a recording layer made of a Te-based material.

However, in recent years, due to the fact that Te-based materials are harmful, the need for higher sensitivity, and the need to lower manufacturing costs, we have changed to Te-based materials and started using dyes as the main material. An increasing number of proposals and reports are being made regarding media using recording layers made of organic materials.

One row is for He-Ne laser.

Scuvrillium dye [JP-A-56-46221 V.

B.Jipson and C.R.Jones
, J., Vac., Sci.

Technol,, 18 (1) 105 (1,9
81)) and metal phtacocyanine dyes (JP-A-57-
82094, 57-82095), etc.

An example of using metal phthalonanine dyes for semiconductor lasers (Japanese Patent Application Laid-open No. 86795/1983) is also discussed.

All of these have a recording layer formed into a thin film by vapor deposition of a dye, and there is no major difference from the Te type in terms of medium production.

However, the reflectance of the dye-deposited film to the laser is generally small, and the current conventional method of obtaining a readout signal by changing (reducing) the amount of reflected light depending on the bit cannot obtain a large S/N ratio.

In addition, if a transparent substrate carrying a recording layer is integrated with the recording layer facing each other, which is a so-called air sand inch structure, and writing and reading are performed through the substrate, the recording can be recorded without reducing the writing sensitivity. Although it is advantageous in that the layer can be protected and the recording density can be increased, such a recording/reproducing method is also difficult with a dye-deposited film.

This is because a normal transparent resin substrate has a refractive index of a certain value (1.5 for polymethyl methacrylate).
For example, in polymethyl methacrylate, the reflectance through the substrate of the recording layer is 2 for the wavelength of the semiconductor laser.
This is because since the reflectance is about 5% or less, it cannot be detected in a recording layer that exhibits only a low reflectance.

In order to improve the readout S/N ratio of a recording layer made of a dye-deposited film, 1. Usually, A1 is placed between the substrate and the recording layer.
A cross-reflection film such as the following is interposed.

In this case, the vapor-deposited reflective film is intended to increase the reflectance and improve the S/N ratio, and the reflective film is exposed by bit formation and the reflectance increases, but this is not surprising. , recording and reproduction through the substrate is not possible.

Similarly, IR-1
A recording layer consisting of 32 colors>'K (manufactured by Kosikku Co., Ltd.) and polyvinyl acetate.
A recording layer comprising l,1'-diethyl-2,2'-1 lycarbocyanine iotite and nitrocellulose, and furthermore, Y, Law, et al., Appl.
Phys, Lett, 39 (9) 718 (19
81) discloses a medium in which a recording layer made of a dye and a resin is formed by a coating method, such as a recording layer made of 3,3'-diethyl-12-7cetylthiatetracarpocyanine and polyvinyl acetate. ing.

However, these cases also have the same drawback as the dye-deposited film in that a reflective film is required between the substrate and the recording layer, and recording and reproduction cannot be performed from the back side of the substrate.

As described above, in order to realize a medium having an organic material-based recording layer that allows recording and reproduction through the substrate, the organic material itself needs to exhibit a high reflectance.

However, conventionally, there are very few examples of a single layer of organic material exhibiting high reflectance without laminating a reflective layer.

It has been reported that the vapor-deposited film of vanadyl phthalocyanine shows slightly high reflectance (P, K170s, atal, A
ppl, Phys, Part A 2G (2)
+01 (1981), JP-A-55-97033], but the writing sensitivity is low, probably due to the high sublimation temperature.

In addition, cyanine dyes and merocyanine dyes such as thiazole and quinoline dyes have been reported [Yamaki et al., Proceedings of the 77th + Five Rivers Physical Society IP-P-9 (19ao)].
A proposal based on this was made in JP-A No. 58-112730, but these dyes have low solubility in solvents, do not easily crystallize, and are not sensitive to readout light, especially when deposited as a layer. On the other hand, it is extremely unstable and immediately bleaches, making it unsuitable for practical use.

In view of these circumstances, the present inventors first developed an indolenine-based cyanine dye that has high solubility in solvents, little crystallization, is thermally stable, and has high paint film reflectance. It is proposed to use it as a single layer 11g (Japanese Patent Application Nos. 57-134397 and 57-134170).

In addition, in other cyanine dyes such as indolenine, thiazole, quinoline, and selenazole, it is possible to improve solubility and prevent crystallization by introducing long-chain alkyl groups into the molecule. (Japanese Patent Application No. 57-182589, Patent Application No. 57-177778, etc.).

Furthermore, it has improved photostability, especially decolorization by readout light (
We have proposed adding a transition metal compound quencher to cyanine dyes to prevent regeneration and deterioration.
Patent application No. 57-1613832, No. 57-188048
No. etc.).

Furthermore, they have proposed forming an ionic bond between one dye and a quencher, thereby further reducing regeneration deterioration and increasing stability (Japanese Patent Application Nos. 58-14848 and 59-18878). No. 59-19715).

By the way, in an optical recording film made of a dye or a dye composition, bits begin to form from the center of the irradiated light at the same time as the light is irradiated, and in the latter half of the irradiated light pulse, bits are absorbed at the center of the irradiated light where the energy is most concentrated. It disappears. Therefore, the efficiency of energy use is low, which is the reason why the sensitivity cannot be improved beyond a certain value.

Therefore, the present inventors have previously proposed that a film with a high melting point, such as a coating film of a colloidal particle dispersion of a silicon-based condensate, be applied as a surface layer (Japanese Patent Application No. 59-62386). etc).

According to this proposal, bits are not formed by irradiating light for a certain period of time, but the temperature rises during that time, and once the temperature has reached a sufficient temperature, bits are formed all at once, resulting in extremely high sensitivity.

However, since such bit formation is performed, there are disadvantages in that the intensity of the B injected light is higher than the contrast obtained, and the medium running speed must be lowered.

In addition, in such cases, under normal conditions, when forming the bit, new or broken surface layers also occur at the bit part, which scatters to other trunks, lowering the S/N ratio and increasing the error rate. There is an inconvenience in making it larger.

■1 Purpose of the Invention The purpose of the present invention is to improve the surface layer of an optical recording medium having a recording layer made of a dye or a dye composition, thereby achieving high sensitivity and low S/N. The objective is to have a high ratio and a low error rate.

■Disclosure of invention These objects are achieved by the invention described below.

That is, the present invention has a recording layer made of a dye or a dye composition on a substrate, and an optical recording medium having a surface layer on this recording layer is irradiated with harmful light to form bits and generate light. This optical recording method is characterized in that during recording, a bit is formed as four parts in an IE in which the surface layer is not substantially broken.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

A dye is contained in the recording layer of the optical recording medium used in the present invention.

There are no particular restrictions on the dyes to be used, including cyanine, phthalocyanine, naphthalocyanine, tetradehydrocholine or tetradehydrocholor, anthratonone,
Any dye such as azo, triphenylmethane, biryllium or thiapyrylium chlorine can be used.

Under these circumstances, the main effect of the present invention is the first one.
It is a cyanine dye.

Among the cyanine dyes, those represented by the following formula (1) are preferred.

Formula (I) Φ-L=ψ (X-)m In the above formula (I), ! and Φ are an indole ring to which an aromatic ring, for example, a benzene ring, a naphthalene ring, a phenanthrene ring, etc. may be incorporated; Includes naanl ring, oxazole ring, selenazole ring, imidazole ring, pyridine ring, etc.

These Φ and ψ may be the same or different, but 1
They are usually the same, and one variety of substituents may be bonded to these rings.

Note that in Φ, the nitrogen atom in the ring has ten charges.

Heavy is one in which the nitrogen atom in the ring is neutral.

The skeleton rings of these Φ and ψ are represented by the following formula [ΦI]
~ [Φ store] is preferable.

In addition, in the following, the structure is shown in the form of Φ.

(R4) q [Φ■] (R4) Q (Ra) q [Φ”) (R4)
[ΦJun] In these various layers, the group R+ (R
+, R+') is a substituted or unsubstituted alkyl group or aryl group.

Groups R,,R,′ bonded to the nitrogen atom in such a ring
There is no particular restriction on the number of carbon atoms in . In addition, when this group further has a substituent, examples of the substituent include a sulfonic acid group, an alkylcarbonyloxy group, an alkylamido group, an alkylsulfonamide group, an alkoxycarbonyl group, an alkylamino toughness, an alkylcarbamoyl hydroxyl group, It may be a carboxy group, a halogen atom, or the like.

In addition, when m described below is 0, the group R1 bonded to the nitrogen atom in Φ is a substituted alkyl or aryl group,
and - has an electric charge.

Furthermore, if the fences of Φ and ψ are fused or non-fused indole rings (formulas [Φ] to [ΦIV)], the 3
At the position, two substituents R2.

Preferably, R3 is bonded. In this case, the two substituents R2 and R3 bonded to the 3-position are preferably an alkyl group or an aryl group. Among these, unsubstituted alkyl groups having 1 or 2 carbon atoms, particularly 1, are preferred.

On the other hand, at a given position in the ring represented by Φ and ψ,
Furthermore, another substituent R4 may be bonded. Such substituents include alkyl groups, aryl groups, heterocyclic residues, halogen atoms, alkoxy groups, aryloxy groups,
Alkylthio group, arylthio group, alkylcarbonyl group, arylcarbonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylcarbonyloxy group, arylcarbonyloxy group, alkylamide group, arylamido group, alkylcarbamoyl group, carboxylic acid group , an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfonamide group, an arylsulfonamide group, an alkylsulfamoyl group, an arylsulfamoyl group, a cyan group, a nitro group, and the like.

7 and the number of these substituents (p.q.r.

s, t) are usually about 0 or about 1 to 4. In addition, when p, q, r, s, and t are 2 or more, multiple R
4 may be different from each other.

Among these, those having a fused or non-fused indole ring of the formulas [Φ] to [Φ■] are preferred.

These have excellent solubility in solvents, coating properties, and stability, exhibit extremely high reflectance, and have extremely high readout S/N ratios.

On the other hand, L represents a linking group that forms a mono-, cy-, tri- or tetracarbocyanine dye, and in particular, a linking group of the formula (L
Any one of I) to [L■] is preferable.

Formula (LI) CH=CH-CH=CH-C=CH-CH=CH-CH
Formula [Lτ) CH=C-CH Formula CI, IX) C Here, Y represents a hydrogen atom or a monovalent group. In this case, monovalent groups include lower alkyl groups such as methyl groups, lower alkoxy groups such as methoxy groups, dimethylamino groups, diphenylamino groups, methylphenylamino groups, morpholino groups, imigsolidine groups, ethoxycarbonylpiperazine groups, etc. dis-substituted amine groups, alkylthio groups such as fulkylcarbonyloxy groups such as acetoxy groups, cyan groups, nitro groups, Br,
It is dangerous to use a halogen atom such as CJI.

In addition, in these formulas (LI"l~[L■], tricarbocyanine linking groups, especially formula% formula%, Cu04-, BF4-.

CH3<>SO3-, Cl-C>S03-
etc. can be mentioned.

Note that m is O or 1, but when m is O, R1 of Φ usually has one charge and becomes an inner salt.

Next, specific examples of the cyanine dye of the present invention will be given, but the present invention is not limited to these.

Five or so! LL engineering J upper 'shi,
” UDI (ΦI) CH3(H2O
2CΦI) CH3CH2 O3(OI) C2Ha OHCH3O
4(Φ I) ((CH2) 3 SO32 CH3(CH2)3 503 N
a4 D5 (ΦII) CH3CH3O6
(001) (CH2>3503-
CH3' (CH2) 3503- Na'' D7 (9 pieces) CH2CH20HC
H: ID 8 (OIII) (CH2
)20COCH3CH2O9(OIII) (
CH2)2 0COCH3CH3014CΦIII)
CH3CH3O11 [Φ01]
CH3CH3O12(ΦI) C,8Ha7
CH3O13 [ΦI) C4
H9CH3014 (OI) C8H, 80COC
H5CH3O15 [ΦI) C7H,,CH,,O
HCH3FLLL y x
x--(LII) HI-(Lll) HCl04- (
L[[[) HI Br-(L
ll) H- -CLII) HCl04- (L
II) H--(LSI)
HCl0a-(Lll) HBr-(Lm)-N (Cs Hs) 2 1
C9,04-(Lll) 1(0
Sentence 04- (Lm) -N (Cs Hs
) 2 1 0 Sentence 04- (L■)
HI-(Lll) HCl
04- (LI[+) -N(CaHs)2
1 Cu04- (Lm)
H 7 animals 1 bag ahead - 'l'RLLiL'
LL work 1 work LLD18 (ΦII
) C8H170H3-DI7 (Φm)
C8H17CH3-018 [Φm), C7H, CO
O-CH3-C7HI4COOH D19 (OIII) C7H,4COOC2H
5CH3-D20 [9 guns] C4H9CH:t
-021 (OIII) C, 8H3□CH3
-D22 [Φ0]:I C4H9CH3-D23
[ΦI) CHCOOCH3CH3-D24
[ΦI) CHOCOCH3CH3-8l5 D25 (ΦI) C8H, C2H5-D26 [
ΦI) C7H15C2Hs -D27 [Φ
II) CHCOOCH3CH3-D28 [ΦI
l) CHCHOCOCH3CH3D29 [Φ
II) C, □H35CH3-L
Y-and-Goichi (L II)
H0 sentence 04 (L II) H
-[Lm] -N N-COOC2Ha 1[L■
) HBF4 CLIII) -N(C8H5)2 1
Cl04〔L■) H0 sentence 04C
LII) HCl04(L II
) HI(LII+) −
N(C8H5)2 1 I(L II )
Hr(LIT)
Hr (LII) HCCl0aCL]-
N N-COOC2Ha 1 I””]-N
N-COOC2Ha 1 ””1 animal 1 bag first-presentation
1L-1 top' Lw-7=LLD
30 [ΦII) CHCOOCH3C2H5-C
31 (Φ [II] C7H,, to CH20HCH3 C32 (Om) CHCH0COC2H5CH3-
C33C0III) C17H34COOC2H5
CH3-C34(OH) C,H2S
CH3-C35 [ΦIII) C7H15
C2H5-C36 [ΦrV ) CH3CHa
-C37 [Φff] CH3CH3-C
38 [ΦIV] C4Hg
(:)13-C39 [ΦIV]
(CH2)20COCH3CH3-C40 [ΦV]
Cz Hs
4-CH5D41 ((>V) CH3-4
-CHsD42 [Φ■] C2H5--C4
3 [ΦV'l) C2H5-5-CID44
[ΦVT) C2H5-5-0CH3D45 [
Φ■) C2H5-5-OCR3L--Eichi
-l-x- [L■) HC view 04 (L II) HC cross 04 (L II
) H1 (L[([) -N (C8H5)2 1
I(LIV) HI I(L
II ) HI (L II ) HI [L■) HC sentence 04 (Lrl) HC look 04 (L II ) H1 (L H) ) (I (L II) HI (Lll) HBr (LI[I) -N( CaHs)z I
Br〔L■) HCH3C6H,5O
3 (Lll) HBr color 1 scoop I'm sorry! 1L-1 work' LL work 1 work LLL-C46 [ΦVl] C,, H5--(L
IT) C47 [ΦVT) C2H5--(LII)
C48 [Φ■) C2H5--(LI) C49 [Φ
VD C2H5--(L■]--(L'V) C50[ΦVT) C2H5--(LV) C51[Φ■] C2H5--(LVT) C52[Φ'1lT) C2H3D53 (O
VII) CCH)OCOCH3--(Lm)C5
4 [ΦVT) CH2CH20H-5-CI (
LIT) --(Lll) C55[Φ■] C2H5 --(Lll) C56[ΦIX) C2H5 --(Lllll) C57[Φ■] C2H5 --(L[[I) C58[Φ[X] C2H5 -- -(Lll) C53[ΦX] C2H5 --(LII) C60(Φ℃) CH2CH,,OH-E1
fX- -I Br HBr HBr CH3Er 1 (I Br HI Br -I Br -N (Cs H5) 2 1 C83G,
)I,5o3HC)13C6H,5O3 HBr HBr OCH31I)
Yue DSL (Φkari) C2H5--D62
[Φ■) (CH2)30COCH3--D63
[to Φ] C2H5--D64 [ΦXl]
CH2C:H2CH2So3H--D65 [to Φ] C2H5-- D66 [Φm] C2H3 D67 [Φtwin] C2H5-- D68 [ΦVT) C8H, □ -
4-CH5D69 [ΦV'l) C,8H3□
--D70 [Φl C8H
,□ --D71 [ΦW) C
8H, □ -5-C or D72 [Φ■]
Cl8H3□ -5-C intersection D73 [Φ
■) C8H,□ -(=2g3 old D74 (ΦVT) C8H,□
-5-0CH3D75 [Φ■) C8H,
7-5-C View L Earthwork (L II) HI (LII) H, I (LDI) -N (Ca Hs) 2 1
C9,04(LIII)-N (Cal H5)
2 1 1 [LH) HBr (Lll) H, Br (Lll) H, I (Lm) -N(CaHs)z l B
r(LH) HCl0a (LIII:l-N(C8H5)2 1
C intersection 04 (LII) H1 (LII) HI [L■] -l I (LII[) -N (C6H5)2 1
Br Mountain O'l'7-"Eng'shi" Yu Beni D7
6 [ΦVl) c 18 H37S C sentence D7
7 [ΦVl) C8H,. -D7
8 [ΦVl) C8H, □ -D7
9 [ΦVl) C, 8H3□ -5-C love D
80 [Φ■) 'C, 8H37-5-C intersection D81
(Φ■] C8H17-DBP [Φ■]
C8H17-D83 [ΦVl) C8H,
-D84 [Φredacted] C3H1□ -
-D85 [Φ■] C11lH37- D86 [Φ■) C13H2□ -
D87 [Φ■] C13H27-- D88 [Φ■) C8H17-D89 (Φ
■) C8H17-D30 [Φ■)
Cl8H3□ --L Engineering f
LX (Lm) -N (C6Hs) 2 1
B r (to Lll) HI (L II ) HC1 (3C:6)14So
3(L II) HC C3) 14SO3(
LV) Ht T (Lm) HI Br 〔L■〕 − (L[II) −N(C8H5)2 1 ,
BrCL II) H, co3c6n
4so3(LII) HBr (Lll) HBr (Lnl)-N○c o o c 2H51, CI O
4 (LIII) OCH31I (L II) HcH3c6n, so3 mountain LΔ
■) C8H17-- D32 [Φ■] Cl8H3□
--D33 [Φ scale] C3HI7
− −D34 [Φ■) C3H1
□ --D95 [Φ cut]
C8H17--D36 [ΦX1l) CHH27-
5-Cdan D97 [Φ store] C8H, □
-D98 [Φ■) Cl8H3
7--D39 [ΦW) C8H17--Dlo
o (Φ twin) C8H17--DIOI
(Φv) C8H17--0102 (Φ-)
C8H,□ 0103 (to Φ) C8H,□
--D104 (ΦI) CH2CH,
, OCOCH3CH3-0+05 (ΦI) C
H2CH20HCH3-0108 (OtlI) C
H3CH3-L Engineering L Text X (L II) Hctt3c6)I4so3
(Lm) -N (Ca Hs) 2 1CH3C
6H4SO3 (Lll) HBr CL II ) I (I CLII) HI (LIII) -N (COHs)2 1
Br(LIII)-N(C8H5)2 1
Br (LII) HBr (Lll) HBr CLU) HBr (LLI) HBr (LII) HBr (L n) H0 sentence 04 [L ■] HBr (LvI) Br l Cl
O2 mountain L" L engineering "2'shi," upper upper D+0
7 CΦI) CH3CH3-DIQ8
(Φ mouth) CH3c)+3 -D109
(ΦVl) C2H5' -6-
C sentence DIIO (Φl) CaH17” -C exemption +
r+ (Φ fan) C2Hs −
DI12 (ΦVl) (H3CH3-D
I13 (Φ■) CH3(:H3-1--
Knee "2 -X- (LV[[) H-C104 [L■) H-Cl0a (LII[) N(G,)+5)21 0 sentence 04
(LII) H-C intersection 04 [L■) H-Cu04 (Lln) N(C6H5)20 Cu04(L
! r) H-CI O4 Furthermore, the second phthalonanine dye has the greatest effect according to the present invention.

There are no particular restrictions on the phthalocyanine used, and examples of the central atom include Cu, Fe, and Co.

N, In, Ga, AM, In(:Jl, InBr.

InnI, GaCl, GaBr, GaI.

AMCM, AQBr, Ti, TiO, Si.

Ge, H, H2, Pb, Vo, Mn, Sn, etc. have +1 power.

In addition, the Hensen ring of phthalocyanine has -OH, halokea, -COOH,
NH2, -Cocu, -Co○R', -0COR' (
However, R' is various alkyl or aryl), -502C1, -503H, -CONH2, -CN, -
Various substituents such as NO2, -3CN, -5H1-CH2C, etc. may be bonded.

Next, specific examples of the light-absorbing dye of the present invention will be given, but the present invention is not limited to these.

Such dyes can be easily synthesized according to the method described in Nitrogen-Containing Heterocyclic Compounds I, page 432, Dai Organic Chemistry (Breakfast Shoten).

That is, first, the corresponding Φ'-CH3 (Φ' represents the ring corresponding to the above Φ) is heated with excess R, I (R is an alkyl group or an aryl group), and R, becomes Φ' to obtain Φ-CH5r-.
Next, this may be subjected to dehydration condensation with unsaturated dialdehyde, unsaturated and droxyaldehyde, pentadiene diallyl, isophorone, etc. using an alkali catalyst such as piperidine or trialkylamine, or acetic anhydride.

Such a dye can also form a recording layer alone.

Alternatively, a recording layer is formed together with resin.

The resin used is preferably a self-oxidizing resin or a thermoplastic resin.

The self-oxidizing resin contained in the recording layer undergoes liquefied decomposition when the temperature rises, and among these,
Particularly suitable is nitrocellulose.

Further, the thermoplastic resin is softened by increasing the temperature of the dye that has absorbed the recording light, and various known thermoplastic resins can be used as the thermoplastic resin.

Among these, thermoplastic resins that can be particularly preferably used include the following.

1) Polyolefin polyethylene, polypropylene, poly4-methylpentene-1, etc.

White) Polyolefin copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester co-septapolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene -maleic anhydride co-combined,
Ethylene propylene terformer (EFT), etc.

In this case, the polymerization ratio of the comonomers can be arbitrary.

1ii) Vinyl chloride copolymer, such as vinyl acetate-vinyl chloride copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-maleic anhydride copolymer, acrylic ester or methacrylic ester, and 1! Copolymers with vinyl chloride, acrylonitrile-vinyl chloride copolymers, vinyl chloride ether copolymers, ethylene or propylene-vinyl chloride copolymers, ethylene-vinyl acetate copolymers with vinyl chloride grafted
such as combined ones.

In this case, the copolymerization ratio can be arbitrary.

i) Vinylidene chloride copolymer Vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-vinyl chloride-7-crylonitrile copolymer, vinylidene chloride-butadiene-vinyl halide copolymer, etc.

In this case, the copolymerization ratio can be set arbitrarily.

V) Polystyrene vi) Styrene copolymer 4 rows For example, styrene-acrylonitrile copolymer (4(A
S resin), styrene-acrylonitrile-butadiene copolymer (ABS resin), styrene-maleic anhydride copolymer (SMA resin), styrene-acrylic acid ester-
Acrylamide copolymer, styrene-butadiene copolymer (SBR), styrene-vinylidene chloride copolymer, styrene-methyl methacrylate copolymer, etc.

In this case, the copolymerization ratio can be set arbitrarily.

vll) Styrene type polymers such as α-methylstyrene, P-methylstyrene, 2
, 5-diglorstyrene, α.

β-vinylnaphthalene, α-vinylpyridine, acenaphthene, vinylanthracene, etc., or copolymers thereof, such as copolymers of α-methylstyrene and methacrylic acid ester.

viii) Coumarone-indene resin Coumarone-indene-styrene copolymer.

ix) Terpene resin or picolite For example, terpene resin which is a polymer of limonene obtained from α-pinene, or picolite obtained from β-pinene.

X) Acrylic resin Particularly preferred are those containing an atomic group represented by the following formula.

Formula RIn "CH-C-" -0R20 In the above formula, R10 represents a hydrogen atom or an alkyl group, and R20 represents a substituted or unsubstituted alkyl group. In this case, in the above formula, RIfl is a hydrogen atom Alternatively, it is preferably a lower alkyl group having 31 to 4 carbon atoms, particularly a hydrogen atom or a methyl group.

Further, R2[I may be a substituted or unsubstituted alkyl group, but the alkyl group preferably has 1 to 8 carbon atoms, and when R2+] is a substituted alkyl group, The substituent for the alkyl group is preferably a hydroxyl group, a halogen atom, or an amide group (particularly a dialkylamino group).

The atomic group represented by the above formula may form a copolymer with other repeating atomic groups to constitute various acrylic resins, but usually one type of atomic group represented by the above formula is used. Alternatively, an acrylic resin is formed by forming a homopolymer or copolymer having two or more repeating units.

xi) Polyacrylonitrile 111) Acrylonitrile copolymer, for example, acrylonitrile-vinyl acetate copolymer, acrylonitrile-vinyl chloride copolymer, acrylonitrile-styrene copolymer, acrylonitrile-vinylidene chloride copolymer, acrylonitrile-vinylpyridine copolymer , acrylonitrile-methyl methacrylate copolymer,
Acrylonitrile-butadiene copolymer, acrylonitrile butyl diacrylate copolymer, etc.

In this case, the copolymerization ratio can be arbitrary.

xiii) Dia-7ton acrylamide polymer Dia-7ton acrylamide polymer obtained by reacting acrylonitrile with a7ton.

xi) Polyvinyl acetate xv) Vinyl acetate copolymers, such as copolymers with acrylic esters, vinyl ethers, ethylene, vinyl chloride, etc.

The copolymerization ratio may be arbitrary.

2) Polyvinyl ethers such as polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl butyl ether, etc.

! ii) Polyamide In this case, the polyamide includes nylon 6, nylon 6-6, nylon 6-10, nylon 6-12. Nylon9. In addition to regular homonylons such as nylon 11, nylon 12, and nylon 13, nylon 6/6-676-1
0, nylon 6/6-6/12, nylon 6/6-6/
Polymers such as No. 11 or modified nylon may be used as the case may be.

xvi) Polyesters For example, various dibasic acids such as aliphatic dibasic acids such as oxalic acid, succinic acid, maleic acid, adipic acid, and sebastenic acid, or aromatic dibasic acids such as isophthalic acid and terephthalic acid, and ethylene. Condensates and co-condensates with glycols such as glycol, tetramethylene glycol and hexamethylene glycol are suitable.

Among these, condensates of aliphatic dibasic acids and glycols and cocondensates of glycols and aliphatic dibasic acids are particularly suitable.

Furthermore, for example, a modified glybutal resin obtained by esterifying and modifying glybutal resin, which is a condensation product of phthalic anhydride and glycerin, with a fatty acid, a natural resin, etc., is also suitably used.

xix) Polyvinyl acetal resin Both polyvinyl formal and polyvinyl acetic resin obtained by acetalizing polyvinyl alcohol are preferably used.

In this case, the degree of acetalization of the polyvinyl acetal resin can be arbitrary.

xx) Polyurethane resin Thermoplastic polyurethane resin with urethane bonds.

Particularly suitable are polyurethane resins obtained by condensation of glycols and diisocyanates, particularly polyurethane resins obtained by condensation of alkylene glycol and alkali diisocyanate.

zxi) Polyether styrene formalin resins, ring-opening polymers of cyclic acetals, -polyethylene oxides and glycols, polyethylene oxides and glycols, propylene oxide-ethylene oxide copolymers, polyphenylene oxides, etc.

xxii) Cellulose derivatives such as nitrocellulose, acetylcellulose, ethylcellulose, acetylbutylcellulose, and droxyethylcellulose.

Various esters and ethers of cellulose, such as hydroxypropylcellulose, methylcellulose, and ethylhydroxyethylcellulose, or mixtures thereof.

xziii) polycarbonates such as polydioxydiphenylmethane carbonate,
Various polycarbonates such as dioxydiphenylpropane carbonate.

zxima) ionomer Na such as methacrylic acid and acrylic acid.

Li, Zn, Mg salts, etc.

! X Ma) Ketone resin examples Eva, condensates of cyclic ketones such as cyclohexanone and acetophenone and formaldehyde.

! ! m) Xylene resin, for example, a condensate of m-xylene or mesitylene with formalin, or a modified product thereof.

XX) Petroleum resins C5 type, C9 type, C5-Cq, copolymer type, dicyclopentadiene type, or copolymers or modified products thereof.

xxviii) A blend of two or more of the above i) to xrvii), or a blend with other thermoplastic resins.

Note that the self-oxidizing compound or thermoplastic resin may have various molecules ψ, etc.. The auto-oxidizing compound or thermoplastic resin and the above-mentioned dye are usually in a stoichiometric ratio of 1. vs. 0.1-100
The layers will be laid in a wide range of quantity ratios.

Preferably, such a recording layer further contains a quencher.

This reduces reproduction deterioration and improves light resistance.

Various quenchers can be used, but especially when the dye is excited and singlet oxygen is generated,
- It is preferably a singlet oxygen quencher that undergoes electron transfer or energy transfer from stacked oxygen to become excited, returns to the ground state by itself, and - converts stacked oxygen to a triplet state.

Various singlet oxygen quenchers can be used, but transition metal chelate compounds are particularly preferred because they reduce acidic deterioration and have good compatibility with dyes. . In this case, the central metal is Ni, Co, Cu, Mn, Pd, Pt.
etc. are preferred, and the following compounds are particularly preferred.

1) Acetylacetonate chelate Ql-IN
1(II) Acetylacetonate Ql-2Cu(II)
Acetylacetonate Ql-3Mn(III) Acetylacetonate Ql-4Co(II) Acetylacetonate 2) Bisdithio-α-diketone system represented by the following formula, where R-R is a substituted or unsubstituted alkyl group or represents an aryl group, M is Ni
, Co, Cu, Pd, Pt, etc. M represents a transferable atom.

In this case, 1M has a single charge and may form a salt with a cation (Cat) such as a quaternary ammonium ion.

In addition, in the following description, ph is a phenyl group, and φ is 1
．． 4-phenylene group, φ' is 1,2-phenylene group, b
enz represents that adjacent groups on the ring are bonded to each other to form a condensed benzene ring.

R1R2R3 Q2-1 ph Ph
phQ2-2 C83COC)13(1:O
CH3C0Q2-3 φN(C2H5)2ph
φN(C2H5)2Q2-4 φN(C)l )
ph φN(C)13)2Q 2-
5 p h p h
phR4M Cat ph Ni - CH5CONi - ph Ni - ph Ni = ph N iN ” (fll:<83)43
) A bisphenyldithiol system represented by the following formula, where R to R8 are hydrogen, an alkyl group such as a methyl group or an ethyl group, a halogen atom such as CfL, or a 7-mino group such as a dimethylamino group or a diethylamide group. where M represents a metal atom such as Ni, Co, Cu, Pd, or Pt.

Furthermore, M in the above structure has a single charge and may form a salt with a cation (Cat) such as a quaternary ammonium ion, and further, other ligands may be bonded above and below M. .

Examples of this include the following.

R5R8R7R8 Q3-I HHHH Q3-2' HCH3HH Q3-3 HC2C Cross H Q3-4 CH3HHCH3 Q3-5 CH3CH3CH3CH3Q3-6
H0 sentence HH Q3-7 C standing C! ;L 0 sentences
C standing Q3-8 HC crossing C standing
c9゜Q3-9 HHHH Q3-10 HCH3CH3H M Cat Nj N"(C2H5)4 Ni N" (n-C4Hg)4Ni
N÷ (n-CaR9)4N I N” (CR
3) 3C18H33Ni N” (n-C4H
g)4Ni N” (n-C4Hg)4Ni
N” (n-C4Hg)4Ni N÷
(n-CaR9)4Co N” (n-C4H
9) 4Co N” (n-C4R9)4R5R
6R7R8 Q3-11 HCH3CH3H Q3-12 HCH3c) (3H Q3-13 C seen C or 0 sentences C
Sentence Q3-14 H0 sentence C again C standing Q
3-15 HN(CH3) 2 HHQ3-
IS HN(CH3) 2 N(CH3) 2
HQ3-1? HN(CH3) 2 CH
3HQ3-18 HN(C:R3)2HH
Q3-+9 HN(CH3) 2 C look
HQ3-20 HN(CH3)2 HH
M Cat Ni N” (n-C4Hg)4NiN+(c
R3) 3c 16H33Nt N+(c R3)
3c 16H33N iN” (CH3)3Cts
H33Ni N” (n-C4Hg)4N i
N” (n-C7Hts) 4Ni N
◆ (C8H17) (C2H5)3Ni
− Ni N÷ (n-C4H9)4Ni N”
(CH) (CH3)3 In addition, JP-A-50-450
No. 27 and those described in Japanese Patent Application No. 163080/1983.

4) Dithiocal represented by the following formula < mic acid chelate system where R9 and R10 represent an alkyl group.

Further, M represents a transition metal such as Ni, Co, Cu, Pd, or Pt.

5) What is shown by the following formula Here, M represents a transition metal atom.

Ql is and Cat represents a cation.

Sex-λ-Cat Q5-I Ni Ql2 2CHN→
(CH3)3Q 5-2 N i Q 12
2C (04H9) 4N”Q 5-3 COQ 12
2C(C4Ha)4N÷Q 5-4 Cu
Q 12 2C: (C:4H9)4N"Q
5-5 P d Q 12 2C (02
H8) 4N" and others described in Japanese Patent Application No. 125654/1983.

6) Those represented by the following formula, where M represents a transition gold atom, RII and R12 are cN and coR''7c, respectively.
o OR'9c ON R"HE11 or 5O2R1
7, R13 to R17 each represent a hydrogen atom or a substituted or unsubstituted alkyl group or aryl group, and Q2 represents an atomic group necessary to form a 5- or 6-membered ring.

Cat represents a cation; n is 1 or 2.

M A Q 6- I N i 5Q6
-2NiS Q6-4 Ni C(CN)2Q
6-5 NiC(CN) 2a
t 2 (n-C4R9) 4 N 2 (n C16H33(CR33) N)Na 2 ((n-C4R9) 4 N) 2 ((n-
c1oH2, o(cH,,)3)(CH3)3N)2(
n-CH(CH) N) +133333 In addition, those described in Japanese Patent Application No. 127074/1982.

7) Compound represented by the following formula Here, M represents a transition metal atom, Cat represents a cation.

nl is 1 or 2.

M Cat Q 7 1 N + 2 ((n-C4
Hg)3N)Q7-2Ni2(n
-c, 5u3a(cHa)3N) In addition, patent application 1983-
As described in No. 127075.

8) Bisphenylthiol-based Q 8-IN i-bis(octylphenyl)
Sulfide 9) Thiocatechol chelate system represented by the following formula, where M represents a transition metal atom such as Ni, Co, Cu, Pd, P, etc.

Further, M has a single charge and may form a salt with a cation (Cat), and the benzene ring may have a substituent.

M Cat Q9 1 N i N” (C4H9) 4
10) Compound represented by the following formula, where R18 represents a monovalent group, O to 6, M represents a transition metal atom, and Cat represents a cation.

1 day MR father Cat Q lOi N iHO5(n-c4Hq)aQ
to-2N i CH31N(n-C4H9)4
What is described in Japanese Patent Application No. 143531/1983.

11) Compounds represented by the following formulas: In the above formula, R, R, R and R23 each represent a hydrogen atom or a monovalent group, and R, R, R and R27 represent a hydrogen atom or a monovalent group. 24 2
5 2B represents a monovalent group, but R and R, R and R, R26 and R27 2425252B may be bonded to each other to form a 6-membered ring.

Moreover, M represents a transition totally bent atom.

Complete set-1L deceased Qll-1CI) n-CH48Hn -C4H3Q
11-2 (I) C2H5COOC2H5CO
OC2H3COOL Dan 24 Dan 25 Dan 28 Dan 2
7 ￥HHHHHHNi C2H3Coo HHHHNi In addition, those described in Japanese Patent Application No. 145294/1982.

12) A compound represented by the following formula, where 1M represents Pt, Ni or Pd, and X+
, N2, X:l, N4 represent J:0 or S, respectively.

L Each"-X"-Artificial Each"-Q12-1 Ni OOO0 Q12-2 Ni S S S
S In addition, those described in Japanese Patent Application No. 58-145295.

13) A compound represented by the following formula, where 31 is a substituted or unsubstituted alkyl group or aryl group.

R, R, R and R35 represent a hydrogen atom or a monovalent group, but 32 and R33, R33 and R34, and R34 and R35 may be bonded to each other to form a 6-membered ring.

Moreover, M represents a transition metal atom.

RRRRP! M Q13-1 nC4H3HHHHN1HCHHNi Q13-2 C6)15H25 Q13-3 n(:4H9HH, benz X
iOthers are described in Japanese Patent Application No. 58-151928.

14) Compounds R41, R41, R43 and R44 shown in both formulas below each represent a hydrogen atom or a monovalent group, but R and R42, R42 and R43, R43 and R44 are bonded to each other to form a 6-membered ring. may be formed.

Moreover, R45 and R48 represent a hydrogen atom or a monovalent group.

Roughly speaking, M represents a transition metal atom. -B
RRR"R""R"'M Q14-IHHHHH-N1 Q14-2 HHC; HOCOHI (-Ni other,
The one described in Japanese Patent Application No. 151929/1983.

15) Compound represented by the following formula , 51 Here, R, R, R, R, R.

R, R, and R58 are each a hydrogen atom or 1
It represents the base of valence.

R and R, R and R, R and R, R and R, R and R, and R57 and R58 may be bonded to each other to form a 6-membered ring.

X represents halogen.

M represents a transition metal atom.

R51R52R53R54 Q+5-I HnC4H9HH Q15-2 HHnC4H30G0 HE11
R56R57R58R59X MHHHHHHC sentence
N1 HHHHHC text Ni Other items described in Japanese Patent Application No. 153392/1982.

16) Salicylaldehyde oxime system represented by the following formula, where R and R61 represent an alkyl group, and M is Ni, Co, Cu, or Pd.

Represents a transition metal atom such as Pt.

R60R61M Q L 6-1 1-C3H71-C3N7 N
1Q16-2 (OH) OH(C)l) CH
Ni2113 2+13 Q L 6-3 (C[) OH(OH2),,0
H3C.

Q l 6-4 (CH) OH(OH2),,C
N3C0Ql6-5 C6N5 C6N5
N1Q16-8 C6N5 C6N5
C.

Ql 6-7 C6N5 Cs
N5 CuQ 1 6-8 NHCs
H et al. NHC6H5N1Q16-9 0HO
HNi 17) Thiohisferrate chelate system haq represented by the following formula, where 1M is the same as above, and R65 and R66 represent an alkyl group. Further, M has one charge and may form a salt with a cation (Cat).

RM □ □ Cat Q l 7-1 t-CHN i N”N3(C:
4H3)Q 17-2 t-CHCON”N3(04
H9) Ql7-3 t-CHNi - 18) Subphosphonic chelate system represented by the following formula, where M is the same as above, and R71 and R72 represent a substituent such as an alkyl group or a hydroxyl group.

RRxvi Q 18-1 3-t-(: H, 5-j-C: 4H
9,6-OHNi; 3) Flood compound represented by the following formula, where R, R, R and R84 are hydrogen atoms or 1
It represents the base of valence.

R,! -R, R and R, R and R are mutually may be bonded to form a 6d ring.

R and R2O each represent a hydrogen atom or a substituted or unsubstituted alkyl group or aryl group.

R86 represents a hydrogen atom, a hydroxyl group, or a substituted or unsubstituted alkyl group or aryl group.

R87 represents a substituted or unsubstituted alkyl group or 7-aryl group.

Z represents a group of nonmetallic atoms necessary to form a 5- or 6-membered ring.

M represents a transition metal atom.

R818283 RRR” Q19-I HOHHH QI9-2HOHtc4HgH Q18-2 tc4H90HH0HR8588 RZM nc5H1H-N1 nc9H19H-Ni CN3 0 HN i In addition, those described in Japanese Patent Application No. 58-153393.

20) Compound represented by the following formula, where R81 and R92 are each a hydrogen atom,
Substituted or unsubstituted alkyl group, aryl group, acyl group, N-furkylcarpamoyl group, N-7lylcarpamoyl group, N-furkylsulfamoyl group, N-7lylsulfamoyl group, alkoxycarbonyl group, or represents an aryloquine group; M represents a transition metal atom;

Q20-1 nC4R9CH3N 1Q2 (12C
R3 (R30-φ-NHCONi and others, patent application 1982-
As described in No. 155359.

In addition, other quenchers include the following.

21) Benzoate Q211 Existing chemical substance 3-3040 (tinuvin-
120 (manufactured by Ciba Geigy)] 22) Hindered amine Q22-1 Existing chemical substance 5-3732 (SANOL
IS-770 (manufactured by Sankyo Pharmaceutical Co., Ltd.)] Each of these quenchers has a concentration of 0.01 to 1 mole of dye.
It is contained in an amount of about 12 moles, particularly about 0.05 to 1.2 moles.

The maximum absorption wavelength of the quencher is preferably greater than or equal to the maximum absorption wavelength of the dye used.

This results in extremely low regeneration and deterioration.

In this case, the difference between the two is preferably 0 or 350 nm or less.

In order to miniaturize the device, it is preferable to use 750.780.830 as a light source for writing and reading.
nm semiconductor laser or 633 nm He-NE
Since it is preferable to use a laser or the like, the maximum absorption wavelength of the doublet oxygen quencher is 680 nm or more, especially 680 nm or more.
80-1500. Even more preferably, 800 = 1
Preferably it is at 500 nm.

Further, when the absorption coefficients of the dye used (the effective value when two or more types are used) and the -multiplet oxygen quencher at the wavelength of the readout light are εD and εQ, respectively, εD/εQ is preferably 3 or more.

Note that when two or more types of dyes are used in combination, the maximum absorption wavelength of one dye and εD are an arithmetic average effective value depending on the concentration.

With such a value, the excitation of the quencher during irradiation with readout light becomes extremely small, and the deterioration of regeneration due to doublet oxygen becomes extremely small.

Furthermore, the quencher may form an ionic bond with the dye.

As a quencher-dye ion conjugate, patent application No. 59-
Those described in No. 14848 may also be used.

However, what can be used more suitably is the patent application filed in 1983.
It is a conjugate of a cyanine dye cation and a quencher anion described in No. 18878 and No. 59-19715.

The cyanine dye cation used may be any of the cations listed above.

In addition, the quencher anion is 3), 5), and 6) above.
, 7), 9), 10), and 17).

A specific example is given below.

In addition, in the following, D÷ is the corresponding cation of D, and Q- is the corresponding anion of quencher.

D+ Moxibustion Knee- 3DL D"l
Q-3-83D2 D”
l Q-3-15SD3
D"l Q'-3-
153D4 D" 10
Q-3-3SD5 D”
10 Q-3-155D6
D + 17 Q-3
-83D7 D” 21
Q-3-83D8 D”
11 Q-3-8SD9
D ÷ 8 Q-3-8SDI
OD” 8 Q-3-250110
” 9 Q-3-15SDI2
D", 106
Q-3-15SDI3
0"10' Q-3-155
D 14 D + 5
Q-3-15SD15'D+
to Q-3-7S018
, 0”, 22 Q-3-15
SDL? D”
105 Q-3-113S D
18D + 7
Q-3-17SD19D”
20 Q-3-18SD20
D “l Q-3-
ISD21 D ◆ l
-Q-3-2SD22
D”l Q-3-18SD2
3D”l
Q-3-17SD24D”
10 Q-3-7SD25
D" 106 Q-3-
8SD 26D” 108
Q-3-73D27
D” +08 Q-3-2SD2
8D + 1OEi
Q-3-163D2! ]
D ÷ 5 Q-3-83D30
D” 5 Q-3
-25D 31D ÷
5 Q”-3-7SD32
D” 5 Q-3-1[1
SD34 D"l
Q-3-8SD35D”
I Q-3-3SD3S
D” 10
Q-3-LSD37
D” 17 Q-17-ISD
38 D 11 Q-10-l5D39
D” 21 Q-
7-25D40D”
9 Q-10-LS
D41 D", 101
Q-6-l5D42 D, +
5 Q-j-3S 043
D” 42 Q-3-
8SD44D” 109
Q-3-8S D 45
D 1 70 Q″ 3-8S D 48
D” 110 Q-3
-85D 47D “ 70
Q-3-15SD48
D” 42 Q-3-1?S 049
D” 43 Q-3
-7SD50 D “ !31
Q-3-8S D 51
D” 111 Q-3-8SD5
2 D “ 112
Q-3-2SD53 D" 1
13 Q-3-85D54
D + 7QQ-2-3Quenchers with such absorption characteristics can vary depending on the light source and dye used.
It is selected and used as appropriate.

In order to form such a recording layer, it is generally necessary to apply it by coating according to a conventional method.

The thickness of the recording layer is usually about 0.03 to 2 g, m. Alternatively, when forming a recording layer using only a dye and a quencher, vapor deposition, sputtering, etc. may be used.

The thickness of the recording layer is 0.04~0.12 gm, especially 0.0
It is preferable that it is 5-0.08 gm.

Below 0.04 gm, particularly 0.03 pm, the absorption and adsorption reflection is as small as before, making it impossible to obtain large write and playback sensitivities.

If the distance is 0.124 m or more, the pre-group will be buried, making it difficult to obtain a tracking signal. Also,
Bit formation is not easy, and writing sensitivity decreases.

In addition, the Q layer may contain other dyes, other polymers or oligomers, various plasticizers, surfactants, antistatic agents, lubricants, flame retardants, stabilizers, dispersants, and antioxidants. A crosslinking agent, a crosslinking agent, etc. may be contained.

To form such a recording layer, it may be applied onto the substrate using a predetermined solvent and dried.

Examples of solvents used for coating include ketones such as methyl ethyl ketone, methyl imbutyl ketone, and cyclohexanone, esters such as butyl acetate, ethyl acetate, carpitol acetate, and butyl carpitol acetate, and ethers such as methyl cellosolve and methyl cellosolve. or aromatic systems such as toluene and xylene, halogenated alkyl systems such as dichloroethane, alcohol systems, etc. may be used.

The substrate on which such a recording layer is provided is made of resin.

Various materials are possible for the resin.

However, among such resins, acrylic resins are particularly susceptible to the various coating solvents mentioned above, especially ketones, esters, alkyl halides, etc., and the effect of the base layer of the present invention is particularly large. Or polycarbonate resin.

Since these are substantially transparent to writing and reading light, writing and reading can be performed from the back side of the substrate, which is advantageous in terms of sensitivity, S/N ratio, etc., and is also effective against dust. It is also advantageous in terms of implementation.

Furthermore, since the moldability is good, it is easy to form tracking grooves.

Acrylic resins include polymethyl methacrylate, etc.
A copolymer or homopolymer mainly composed of a methacrylic acid ester having a chain or cyclic alkyl group having 1 to 8 carbon atoms is preferred.

Furthermore, as the polycarbonate resin, bisphenol A type is preferred.

When these acrylic resins or polycarbonate resins are formed by injection molding, the effect of the base layer of the present invention becomes even greater.

Note that the number average degree of polymerization of these acrylic resins or bocker carbonate resins is preferably about 800 to 6,000.

The surface layer provided on the recording layer H may be a film having a high melting point and high hardness.

Therefore, the vapor phase deposition of various oxide-based, nitride-based, and carbide-based inorganic substances, such as silicon oxide, titanium oxide, aluminum oxide, magnesium oxide, zirconium oxide, silicon nitride, and silicon carbide Good too.

Alternatively, it may be a hydrolyzed coating film mainly formed from silicon oxide, titanium oxide, acid zirconium, aluminum oxide, etc. formed from a chelate compound known as a so-called crosslinking agent.

However, among these, the most right-handed is the coating film of a colloidal particle dispersion of a silicon-based condensate.

The colloidal particles of the silicon-based condensate are preferably hydrolyzed condensates of silicon halogenide, especially silicon tetrachloride, or realkyl silicic acid, especially tetra-lower alkyl (methyl, ethyl) silicic acid.

And the colloid particle size is 30 to 100, especially 50
~80 people.

Further, as the dispersion medium, an alcohol, particularly one aliphatic alcohol, an alkyl acetate, or a mixed solvent of these and an aromatic hydrocarbon is used.

Moreover, for hydrolysis, a mineral acid is added as necessary.

Then, a stabilizer such as ethylene glycol, a surfactant, etc. are added as necessary.

An example of such a colloidal particle dispersion is silicon tetrachloride (Si0M) described in Japanese Patent Publication No. 31-8533.
4) and a monohydric aliphatic alcohol are dissolved in acetic acid alkyl ester.

Alternatively, 1 to 20 wt% of ethylene glycol may be added to a solution of tetraalkyl silicic acid, monovalent aliphatic alcohol, alkyl acetate, and mineral acid described in Japanese Patent Publication No. 3Ei-4740.

Furthermore, an alcohol solution of tetra-lower alkyl silicic acid described in Japanese Patent Publication No. 45-35435 may also be used.

In such a case, the monohydric aliphatic alcohol used is methyl alcohol, ethyl alcohol, denatured alcohol, isopropyl alcohol, butyl alcohol or a mixture thereof.

As the alkyl acetate, methyl acetate, ethyl acetate, amyl acetate, butyl acetate, or a mixture thereof may be used, and as the mineral acid, an aqueous solution of hydrochloric acid or sulfuric acid, etc., which is commonly used in industry may be used. .

Incidentally, these dispersions may be applied by spinner coating or the like according to a conventional method.

In this case, the diluting solvent includes, for example, a mixed solvent of a hydrocarbon type and an alcohol type.

Then, drying may be performed at 40 to 80°C for about 20 minutes to 2 hours.

The coating film thus formed is a silicon oxide coating film containing hydroxyl groups.

The thickness of the above first surface layer is 0.005 to 0.03 pm.
It is. Particularly preferably 0.008 to 0.012g
It is preferable that it is m.

If the first surface layer is less than 0.003 m, the effect of improving writing and reading sensitivity as an optical recording medium cannot be obtained.

When the first surface layer exceeds 0.03 ILm, the writing/reading sensitivity of the optical recording medium is rather reduced.

In an optical recording film made of a dye composition, bits are formed at the same time as the film is irradiated with light, and the subsequent irradiated light is no longer absorbed at the center where the energy is most concentrated. Therefore, the energy use efficiency is low, which is the reason why the sensitivity cannot be improved beyond a certain value.

The surface layer of the present invention is a hard film with a high melting point, and is designed to prevent the formation of bits when exposed to light that is irradiated for a certain period of time or less.

Even when providing a surface layer with a high melting point, by adjusting the intensity, pulse width, rotation speed, etc. of the writing light,
Four bits are formed with the surface layer being substantially continuous and without substantial breakage.

Therefore, while maintaining high sensitivity, a decrease in the S/N ratio and an increase in the error rate due to the scattering of surface layer fragments can be prevented.

Note that such writing conditions can be easily determined experimentally.

Note that the fact that the surface layer is substantially continuous and does not break means that the occurrence of pinholes that can be ignored with respect to the bit diameter is allowed.

Moreover, such a surface layer may be a composite laminated film.

Furthermore, a polymer film may be laminated as an upper layer on such a surface layer.

The provision of such a polymer film also prevents breakage of one surface layer.

Various polymers can be used, but in particular, the polymer should not invade the above-mentioned surface layer and dissolve the dye, should have good adhesion, good uniformity, good coatability, and low viscosity. For these reasons, it is preferable to use a coating film of a polymer compound that is soluble in water or a water-alcohol mixed solvent and contains hydroxyl groups. may be one that can be dissolved in water or a water-alcohol mixed solvent as described below to an extent of about 1% or more.

Such polymeric compounds may be polysaccharides such as gum arabic, alginic acid, gum tragacanth, etc.
In particular, cellulose derivatives and vinyl alcohol unit-containing resins as shown below are suitable.

1) Cellulose derivatives nitrorelulose, acetylcellulose, ethylcellulose, acetylbutylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylhydroxyethylcellulose, etc.

In this case, it is preferable that one or more hydroxyl groups are contained on average per repeating unit.

2) Completely or partially hydrolyzed resins containing vinyl alcohol units, such as polyvinyl alcohol, polyvinyl acetate, and ethylene-vinyl acetate copolymers.

In this case, the vinyl alcohol unit is 70 mol% or more,
Preferably, the content is 80 mol% or more.

Note that there is no particular restriction on the number average molecular weight of such a polymer compound.

Such a polymer compound is usually dissolved in a water-alcohol mixed solvent and applied as a layer.

In this case, the alcohol is preferably methanol, ethanol, propatool, butanol, etc. alone or in combination. The mixing ratio of water and alcohol is
1: about 0.5 to 3.

Although water can be used alone as the coating solvent, a water-alcohol mixed solvent is superior in terms of coating properties on resin substrates.

When coating such an underlayer, a crosslinking agent may be added to the coating solution to crosslink the polymer compound in the coating film.

At this time, solvent resistance, water resistance, and heat resistance are improved, and the stability of the recording layer is improved.

In this case, surfactants, antifoaming agents, antistatic agents, etc. are added to the coating solution for the base layer in order to prevent the formation of pinholes, completely defoaming, and lower the viscosity. It's okay.

The crosslinking agent used is preferably an organic compound or chelate of titanium, zirconium, or aluminum, or an aldehyde, oxycarboxylic acid, or methylol-containing oligomer.

Such a polymer membrane preferably has a thickness of 0.002 to 0.8 Bm, more preferably 0.005 to 0.5 pm (7).

If it is less than 0.002 pm, there is no effective scattering prevention;
This is because, if it exceeds 8 Bm, the sensitivity decreases.

Furthermore, the recording layer having the surface layer of the present invention may be formed directly on the substrate, or may be provided via an underlayer.

The underlayer may be of various known types, or is preferably prepared in exactly the same manner as the first surface layer or polymer film described above.

The thickness of the base layer is o, oos to 0.05 m.
In particular, it is preferably o, ooa to 0.03 m.

When the thickness of the underlayer is less than 0.005 m, the effect of imparting solvent resistance and heat resistance to the substrate is insufficient.
If it exceeds 0.05 pm, sensitivity decreases.

By providing the underlayer as described above, the sensitivity as an optical recording medium is further increased and the S/N ratio is further improved.

Usually, a recording layer is directly formed on the underlayer, but if necessary, another intermediate layer may be formed between the underlayer and the recording layer.

Similarly, various uppermost protective layers, a half-mirror layer, etc. can be further provided on the surface layer. However, it is preferable not to stack the reflective layer.

The medium of the present invention may have the above recording layer on one side of such a substrate with an underlayer interposed therebetween, or may have recording layers on both sides thereof with an underlayer interposed therebetween. good.

In addition, two recording layers are coated on one surface of the substrate with an underlayer interposed between them, and the recording layers are placed facing each other with a predetermined gap between them. You can also choose not to have one.

Note that it is preferable not to laminate a reflective layer on the recording layer.

In the recording method of the present invention, for the medium.

While it is running or rotating, recording light is irradiated in a pulsed manner.

At this time, due to the heat generated by the dye in the recording layer, the self-oxidizing resin decomposes or the thermoplastic resin and the dye melt, forming pints.

In this case, writing is preferably performed from the gas back side.

In particular, when a tri- or tetracarbocyanine dye is used, extremely good writing can be achieved when a recording semiconductor laser diode with a wavelength of 750.780.830 nm is used.

In addition, when using phthalocyanine dye, 730~
When using a recording semiconductor laser diode with a wavelength of 760 nm, very good writing can be performed.

The bits formed in this way are read out by detecting the reflected or transmitted light, especially the reflected light, of the readout light of the above-mentioned wavelength while the medium is running or rotating.

In this case, it is preferable that the readout light is irradiated from the back side of the substrate and the reflected light is detected.

Note that when a thermoplastic resin is used for the recording layer, the bits once formed on the recording layer can be erased with light or heat and then rewritten.

Further, a He-Ne laser or the like can also be used as the recording or reading light.

In such a case, in order to form a bit without substantially breaking the surface layer according to the present invention, as described above, when forming a normal high melting point surface layer,
Adjust writing conditions. That is, the light intensity may be slightly lowered and the speed at which the irradiated light passes through the recording medium may be increased. At this time, high-speed recording can be performed at the same time.

Furthermore, a polymer film may be formed on the surface layer to prevent the surface layer of the bit portion from breaking.

■Specific Effects of the Invention The present invention uses an optical recording medium having a surface layer with a high melting point in the recording layer made of a dye or a dye composition, and forms bits in such a state that the surface layer does not break. So,
The intensity of the writing light required to obtain the same contrast is reduced, and the medium running speed can be increased.

Then, by setting the polymer film layer and writing conditions,
Since breakage of the surface layer during bit formation and accompanying scattering are prevented by IF, the S/N ratio is improved and the error rate is reduced.

(2) Specific Examples of the Invention The present invention will now be described in more detail by way of Examples.

Example 4.2 parts of tetraethyl hydrochloric acid 43 parts of ethyl alcohol 42 parts of ethyl acetate 5.4 parts of concentrated hydrochloric acid 5.4 parts of ethylene glycol were mixed into a PMMA (MFI = 2) injection molded substrate having a diameter of 30 cm. A colloidal dispersion of 80 people was prepared and diluted with n-propertool to prepare a coating liquid.

This was spin-neat and then treated at 60°C for 30 minutes. The film thickness is 0.01 pm.

Then, dye D-10 and quencher Q3-8 (
A recording layer containing a 1% dye solution (dichloroethane, dichlorohexanone (6:5)) of 5:2) was formed using a spinner.

Furthermore, a surface layer was formed on this recording layer by applying a solution prepared by diluting the colloidal dispersion liquid with n-hexane using a spinner. The film thickness was approximately 0.0 part 6 m.

The above is designated as sample 1.

Sample 1 without a surface layer is designated as sample 2.

Furthermore, in sample 1, polyvinyl alcohol PVA (manufactured by Kuraray Co., Ltd. 205 with a hydrodispersion rate of 88%) was added on the surface layer.
) dissolved in methanol-water (1°1) at a concentration of 1 part was coated and applied to form a layer with a thickness of about 0.8 parts OL.

For the above samples, using an 830 nm semiconductor laser,
Writing was performed from the back side of the substrate at a predetermined medium speed with a condensing part intensity of 8 mW to 10<1>-, a pulse width of 100 ns, and the contrast of the signal was measured.

In addition, the presence or absence of breakage of the surface layer at the bit portion and the presence or absence of scattering of the surface layer were observed using an electron microscope.

The results are shown in Table 1.

From the results shown in Table 1, the effects of the present invention are clear.

Claims (1)

[Claims] (1) An optical recording medium having a recording layer made of a dye or a dye composition on a substrate and a surface layer on this recording layer,
1. An optical recording method characterized in that, in performing optical recording by forming bits by irradiating writing light, the bits or the surface layer are formed as recesses in a state where they are not substantially broken.