JPS6375071A - Radiation curable paint - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a radiation-curable coating material, which is used in particular when mixed with magnetic powder to produce magnetic recording media such as magnetic tapes and magnetic disks. The present invention relates to a radiation-curable paint that is suitably used as a magnetic paint.

[Conventional technology]

Generally, a magnetic recording medium has a magnetic layer formed by coating a support such as a polyester film with a magnetic paint consisting of magnetic powder, a polymer, a solvent, and various additives.

In recent years, radiation-curable polymers with acrylic double bonds have been used as the polymers used to prepare the above-mentioned magnetic paints, and radiation-curable magnetic paint coatings made by mixing this with magnetic powder, solvents, etc., have been cured by radiation irradiation. There are known ways to do this. In order to improve the dispersibility of magnetic powder in such radiation-curable paints, radiation-curable paints are known that use resins in which phosphorus-containing compounds are reacted with polymers having acrylic double bonds. Publication No. 77134/1983).

In addition, there is also known a thermosetting coating for producing magnetic recording media that uses polyurethane reacted with a phosphorus-containing compound represented by the formula as a polymer in order to improve the dispersibility of magnetic powder. 59-154634).

[Problem that the invention seeks to solve]

However, the magnetic recording medium manufactured using the radiation-curable paint described in JP-A-61-77134 has a problem in that its actual running durability is insufficient.

Furthermore, a magnetic recording medium manufactured using a magnetic paint containing polyurethane as a component described in JP-A-59-15463 also has the problem of insufficient actual running durability.

An object of the present invention is to provide a radiation-curable coating material that provides a magnetic recording medium that has excellent characteristics such as good dispersibility of radiation-curable magnetic powder and also has high actual running durability.

[Means for solving problems]

The present invention solves the above-mentioned problems by using the following general formula (I): [In the formula, R1 and R1 may be the same or different, and each represents a methyl group, an ethyl group, a butyl group, a hexyl group, an octyl group, C3 to C2O alkyl groups such as dodecyl group, pentadecyl group, eicosyl group, preferably methyl group,
C such as ethyl group, propyl group, hexyl group, octyl group, etc.
It is an alkyl group of I to C2, and R3 is an alkyl group of C2 to C2, such as a methylene group, an ethylene group, a propylene group, a pentamethylene group, etc.
R4 and R% may be the same or different, and are linear or branched alkylene groups such as ethylene group, propylene group, hexamethylene group, octamethylene group, decamethylene group, preferably ethylene group. basis,
It is a C1-C& alkylene group such as a propylene group, a tetramethylene group, a hexamethylene group; n and β may be the same or different, and each is a number from 0 to 19. ] Phosphorus-containing structure represented by and the following general formula (■): [Here, R6 is the same as R1 and R2; R7 and R8 may be the same or different, and are the same as R4 and R5; m and p are the same as n and l.

] At least one type selected from the phosphorus-containing structure represented by 10-7 to 10-'' moles per 1 g of polyurethane,
The present invention also provides a radiation-curable coating material containing a polyurethane having a radiation-polymerizable double bond (hereinafter simply referred to as "polyurethane").

This polyurethane contains at least one type selected from the phosphorus-containing structures represented by formulas (1) and (II) in an amount of 10-7 to 10-3 mol, preferably 10-h to 10-4 mol, per 1 g of polyurethane. Must have. When the phosphorus-containing structure represented by the general formulas (1) and (II) exceeds 10 −3 mol per 1 g of polyurethane, general-purpose solvents commonly used when the radiation-curable paint of the present invention is used as a magnetic paint, for example, The solubility in toluene, methyl ethyl ketone, methyl isobutyl ketone, etc. tends to decrease, and the hygroscopicity of the coating film cured by radiation increases, which tends to cause a decrease in coating strength (If the amount is less than 10-7 mol, magnetic powder It becomes difficult to sufficiently disperse the magnetic paint in the magnetic paint, and the actual running durability also decreases.

Furthermore, it is essential that the polyurethane used in the present invention has a radiation-polymerizable double bond, and such a radiation-polymerizable double bond is, for example, represented by the following general formula (III
) to (V) are included in polyurethane.

C8z = CCOR”−・・・・・・・・・(I[[)
(In the formula, R9 is a hydrogen atom or a methyl group, RIO
represents a C2-C3 alkylene group such as an ethylene group, a propylene group, a hexamethylene group, an octamethylene group,
] [In the formula, R9 is the same as in formula (DI). ] [During the ceremony,
R' is the same as in formula (III). ] The polyurethane used in the present invention has the above-mentioned formula (1) and (I
The phosphorus-containing structure represented by I) and the general formula (III) ~
In addition to the structure having a radiation-polymerizable double bond represented by (V), etc., it has other structures, and the groups represented by general formulas (1) to (V) and other structures are mainly urethane bonds (-N -C-0-), but in some cases an additional urea bond (-N-C-N
-”) may be included.

Typical embodiments of the polyurethane used in the present invention include at least one type selected from the phosphorus-containing structures represented by formulas (1) and (II), and general formulas (III) to
At least one type selected from structures having a radiation double bond represented by (V) and the following general formulas (Vl) to (Xl
At least one selected from the structures represented by l) is a structure containing a urethane bond represented by the following general formula (XI[I), and in some cases further a structure containing a urea bond represented by the following general formula (XIV). Examples include those that are connected via a

+R"0-C-R'"-C-0-)-Rth-...
... (Vl) [wherein R11 is an alkylene group of 02 to C4, preferably 02 to C4, such as an ethylene group, a propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and R12 is CHI CH=CHCH2-9CI=CH-CHI3
-C=C11-.

(Clh)-2-, (CI(z)"-(CH2)"(C
ih) r-, (C) Iz) r-02 to C8 such as C=C-
is a divalent aliphatic group, alicyclic group or aromatic group, and q is a number from 1 to 50. ] → R110 ÷ "R11-...
......(■) [In the formula, R1+ is the general formula (Vl
), and S is a number from 1 to 50. [In the formula, R11 is the same as in general formula (Vl), and t and U may be the same or different, and each is a number from 1 to 20. ] 1 + - + ClI2 light CO ``R33 → OC ÷ C) 12
Treatment → Ma... (IX) [In the formula, R13 is X CH3X -CHl-0-beCIItCHg 0h-CHI-
, C11゜C11x 0-(CIIzCHlCHzCIIzO
+T-CIlt-1CI+3 (In the formula, a is an integer of O to 20, preferably 1 to 10, and X means a fluorine atom, a chlorine atom, or a bromine atom). Add one divalent aliphatic group, alicyclic group or aromatic group of 02 to C2°, preferably 04 to C4%, and add these aliphatic groups, alicyclic groups and aromatic groups as exemplified above. The group group has 10-1- in its structure.
C-0- or -N-0R24 (R14 has a hydrogen atom, a hydroxyl group, or a substituent such as a methyl group, an ethyl group, a propyl group, a butyl group, an acetic acid phenyl group, a benzyl group, a cyclohexyl group, or a cyclopentyl group) Cs may have an aliphatic group, an alicyclic group or an aromatic group. may contain a petero atom, ■ and W may be the same or different, and each number is from 1 to 20.] CtlCIIzOR" C1hCII- [wherein, RI
S is a group represented by -(C)IzCHzO)r-Hs or CH3, X is a number from 1 to 20, and R9
is the same as R' in the general formula (I[[). ]AR"O
hτR'hi ...... (xI) [In the formula, R1 is the same as the general formula (■), and y and 2 may be the same or different (, each is a number from 1 to 30, , n゛ is 1~
5, and M is an alkali metal such as potassium or sodium. [In the formula, R11 is the same as in the general formula (Vl), and S and S' may be the same or different (1 to 50, respectively)
, and R1& is 02 to C4°, preferably C, -C, etc. , particularly preferably a tetravalent aliphatic group, an alicyclic group, or an aromatic group of 02 to CI3. ] (In the formula, R1? is a divalent hydrocarbon group of →C1, C1 to C!, etc.).]HH)IH [In the formula, R17 is the same as the above general formula [■]. ] The polyurethane used in the present invention can be manufactured, for example, by the following manufacturing method.

In the first step, the following general formula (al and (b):
In the formula, R1, R1, R3, R4, RS, n and l are the same as in general formula (1). ].

[wherein R6, R7, R3, m and p are of the general formula CI
It is the same as ] Selected from the phosphorus diol-containing compounds represented by (
and one of the following general formulas (C) to (1): [wherein, R1
1.RI! and q are each the same as in general formula (Vl). ] HO+R"O+r-R"OH..."(di [In the formula, R1 and S are the same as in the general formula (■).]

C) I3 [wherein R1, t and U are the same as in general formula (■). ], [wherein R'3, ■ and W are the same as in general formula (IX). ], [wherein RIS and R1& are the same as in general formula (X). ], [In the formula, R", y% 2% n' and M are the same as in the general formula (XI).], 0O II II [In the formula, R', s, sl and R1 & are the same as in the general formula (XI) (■)
is the same as ] At least one selected from the diol compounds represented by
The species and, if necessary, a diol compound other than the above, are combined into the following general formula (J): OCN R"NGO...0) [wherein, R
1? is the same as general formula (XI). ] is reacted with a diisocyanate compound represented by

In the reaction of this first step, the diisocyanate compound represented by 2〇) is used in stoichiometric excess with respect to the total amount of the above-mentioned phosphorus-containing diol compound and other diol compounds, and The reaction components are combined to produce a polymer having an isocyanate group at the end of the molecule (hereinafter referred to as "polymer A"). In addition, in this first step, aliphatic diamine, alicyclic diamine, aromatic diamine with or without substituents such as methyl group, ethyl group, propyl group, polyether diamine, etc. are used as the chain extender. You can. Specific examples of these chain extenders include ethylene diamine, tetramethylene diamine, hexamethylene diamine, cyclohexyl diamine, paraphenylene diamine, polyoxyethylene diamine, polypropylene diamine, and the like.

Next, in the second step, the polymer A produced in the first step is
, the following general formula (k) ~ ((2): CHz=CCOR
I@OH...(k) [In the formula, R'l and R1
1 is the same as general formula (I[I). ], cut=c (R')-C-0-CHz [wherein, R9 is the same as the general formula (I[I)]. ], [wherein R9 is the same as in general formula (III). By reacting at least one selected from (meth)acrylate compounds having a hydroxyl group represented by The above general formula (nl
It is possible to obtain a polyurethane used in the present invention in which structures having radiation-polymerizable double bonds represented by (V) and the like are bonded via urethane bonds.

Moreover, as the second step, the following method can be used instead of the above method.

First, a (meth)acrylate compound represented by 1 to tm+ etc. in the above general formula + is added to the polymer A produced in the first step.
By reacting the isocyanate groups in a stoichiometrically approximately % equivalent, one of the two terminals of the polymer A molecule is treated with radiation-polymerizable diamides represented by the above -JIQ formulas (ml) to (V), etc. Structures having double bonds are bonded via urethane bonds to produce a polymer (hereinafter referred to as "polymer B") in which an isocyanate group remains at the other end. Next, the following general formula (n) is applied to the polymer B thus obtained.
: [Wherein, Q is a tetravalent organic group. By reacting the tetrahydric alcohol compound represented by ], the remaining isocyanate groups of the polymer B can be bonded to the tetrahydric alcohol compound via a urethane bond, and the polyurethane used in the present invention can also be obtained by this method. be able to.

The reaction in the first step is usually carried out using a catalyst such as copper naphthenate, cobalt naphthenate, zinc naphthenate, n-butyltin laurate, or triethylamine. These catalysts were used in a total amount of 100% of the starting materials used in the first step.
It is preferable that the amount is about 0.01 to 1 part by weight.

The reaction in the second step can be carried out in the presence of the same catalyst as in the first step. The catalyst is preferably used in an amount of 0.01 parts by weight based on 100 parts by weight of the polymer A produced in the first step.
~1 part by weight is used.

The reactions in the first and second steps can be carried out sequentially without isolating the products of each step, and the reaction temperature in either step is preferably 30 to 80°C.

A solvent can be used in the reactions in each of the above steps,
The solvent is not particularly limited as long as it does not inhibit the above reaction, and examples thereof include methyl ethyl ketone, cyclohexanone, tetrahydrofuran, toluene, methyl isobutyl ketone, and dioxane.

I'l used in the above polyurethane manufacturing method
The proportion of the phosphorus diol-containing compound represented by Q formula (a) or (b) is usually 0 to the resulting polyurethane.
．． 01 to 30% by weight, particularly preferably 0.1 to 10% by weight. When the proportion of the phosphorus diol-containing compound represented by the general formula (a) or (b) exceeds 30% by weight based on the polyurethane, the polarity of the resulting polyurethane increases, the solubility in solvents decreases, and radiation This increases the hygroscopicity of the cured coating film, which tends to cause a decrease in coating strength after curing.

On the other hand, if the proportion of the phosphorus diol-containing compound used is less than 0.01% by weight based on polyurethane, the affinity for inorganic compounds will be insufficient, and especially when used as a magnetic paint, the dispersion of magnetic powder will be insufficient. Become.

In addition, the proportion of the total amount of the (meth)acrylate compound expressed by the general formula (k1 ~ (ml, etc.) used in the above polyurethane production method is preferably 0.2 to 40% by weight, based on the polyurethane obtained. Particularly preferably, it is 0.5 to 30% by weight.If the proportion of the (meth)acrylate compound used exceeds 40% by weight, the coating film cured by radiation will lose its flexibility and the mechanical properties of the coating film will be impaired. On the other hand, (meth)acrylate compounds represented by general formulas (k1 to (m), etc.)
．． If the amount is less than 2% by weight, the curing of the coating film by radiation will be insufficient, and when used as a magnetic coating material, its actual running durability will be reduced.

In addition, in the above manufacturing method, -J'G formula (C) ~ (f)
When using compounds represented by, their Lgffi
The amount used is preferably 60 to 95% by weight, particularly preferably 75 to 90% by weight, based on the polyurethane obtained. If the amount used is less than 60%, the flexibility of the coating film cured by radiation properties are lost and the mechanical properties of the coating are impaired. On the other hand, if the compound represented by general formulas (C) to (f) exceeds 95% by weight based on the polyurethane, the content of the compounds represented by general formulas (k) to (m), etc. will decrease, making curing by radiation difficult. It becomes insufficient.

In the above production method, when a compound represented by the formula (gl) is used, its usage ratio is preferably 30 weight% or less, particularly preferably 20 weight% or less, based on the polyurethane obtained. If it exceeds 30% by weight, the flexibility of the coating film cured by radiation will be impaired.

In the above method for producing polyurethane, when the compounds represented by general formulas (h) and (1) are used, the total amount used is preferably 20% by weight or less, particularly preferably 10% by weight or less, based on the polyurethane obtained. If the usage ratio exceeds 20% by weight, the polarity of the resulting polyurethane increases, the solubility in general-purpose solvents such as toluene and methyl ethyl keto decreases, and the moisture absorption of the coating film cured by radiation increases. This tends to lead to a decrease in coating film strength.

Next, specific examples of each reaction component compound used in the above-mentioned method for producing polyurethane will be shown.

-i As a compound represented by the formula (a), for example, the compound represented by the formula Examples include phosphorus-containing diols represented by the following.

For example, compounds represented by the formula %formula% Examples include phosphorus-containing diols represented by the following.

-C Compounds represented by formula (C) include, for example, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1.
6-hexanediol, neopentyl glycol, 1.
Examples include polyester diols obtained by reacting polyhydric alcohols such as 4-cyclohexane dimetatool with polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, and cepatic acid. It will be done.

Examples of the compound represented by the -a formula (d) include polyether diols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

Examples of the compound represented by the -a formula (e) include polyether diols such as ethylene oxide of bisphenol A or alkylene oxide adducts of propylene oxide.

-1 Examples of the compound represented by formula (f) include polycaprolactone diol obtained by a known method such as ring-opening reaction of ε-caprolactone using glycol as an initiator using caprolactone and a corresponding diol. Can be done.

-1 As the compound represented by formula (g), acrylic and methacrylic compounds having a carboxyl group and acrylic and methacrylic compounds having a hydroxyl group are used per mole of a jepoxy compound containing two epoxy groups in one molecule. Examples include diol compounds synthesized by reacting 1 mole or more of at least one type of compound selected from the compounds and performing addition polymerization until the epoxy groups in the entire reaction system disappear. Examples of the jepoxy compound here include glycidyl ether of polyhydric phenol obtained by reacting bisphenol A and epichlorohydrin; Examples include glycidyl ether of polyhydric alcohol obtained by reacting alcohol and epichlorohydrin.

Examples of the compound represented by formula (h) include diol compounds that can be produced by reacting the polyether diol compound represented by the above general formula (dl) with sulfoisophthalic acids. Examples of isophthalic acids include 5-sodium-
Sulfo-isophthalic acid, 5-potassium-sulfo-isophthalic acid, 5-sodium-sulfo-isophthalic anhydride, di-lower alkyl 5-sodium-sulfo-isophthalate such as dimethyl or diethyl, di-5-potassium-sulfo-isophthalate. Mention may be made of lower alkyl such as dimethyl or diethyl.

-C The compound represented by formula (1) is a small amount selected from the polyether diol compounds represented by the above general formula (d) (with respect to 911 mol of one type of compound, 1
Examples include diol compounds that are synthesized by reacting less than a mole of tetracarboxylic dianhydride, esterifying or amidating it, and conducting an addition polymerization reaction until the acid value of the entire system reaches the initial value of 2.

Examples of the compound represented by -m2〇) include 2.
4-) Luene diisocyanate) 2.6-) Luene diisocyanate, 1.3-Xylene diisocyanate, 1.
4-xylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p
-phenylene diisocyanate, 3,3'-dimethyl-
4,4'-diphenylmethane diisocyanate, 4.4
'-Diphenylmethane diisocyanate, 3.3'-'
Methylphenyl diisocyanate, 4,4'-biphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and the like.

Examples of the compound represented by the general formula (k) include 2
-Hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyoctyl (meth)acrylate, and the like.

Examples of the compound represented by the general formula +1) include glycerin di(meth)acrylate.

Examples of the compound represented by the formula -i+ml include pentaerythritol tri(meth)acrylate.

Examples of the tetrahydric alcohol compound represented by the general formula (nl) include pentaerythritol, N, and N.

N',N'-tetrahydroxypropylethylenediamine and the like can be mentioned.

Although the polyurethane used in the present invention can be obtained by the above manufacturing method, the method for manufacturing the polyurethane is not limited thereto.

The molecular weight of the polyurethane used in the present invention is usually 2
．． 000-100,000, preferably 4,000-6
It is 0,000. If this molecular weight is less than 2.000, the strength of the coating film cured by radiation will decrease, and if the molecular weight exceeds 100.000, the viscosity of the solution will increase and it will be difficult to handle when preparing the paint. Moreover, especially when preparing a magnetic paint, a large amount of solvent is required to reduce the viscosity, which is not economical.

The radiation-curable coating material of the present invention is usually prepared by mixing the above-mentioned polyurethane and other ingredients using a suitable organic solvent as a medium. Examples of the organic solvent used include methyl ethyl ketone, cyclohexanone, tetrahydrofuran, toluene, methyl isobutyl ketone, and dioxane.

The radiation-curable coating material of the present invention may optionally contain a polymer having a radiation-polymerizable double bond and/or a monomer compound having a radiation-polymerizable double bond other than the polyurethane used in the present invention. You can also do it.

Furthermore, in addition to the above-mentioned polyurethane, the radiation-curable paint of the present invention may also include polyvinyl butyral, polyvinyl acecool, polyurethane, polyester, polyester having sulfonic acid and/or metal base in the molecule, epoxy resin, epoxy urethane. Resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, hydroxyl group-containing vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer, hydroxyl group-containing vinyl chloride-vinyl propionate copolymer, vinyl chloride - Vinyl acetate-acrylic ester copolymer, hydroxyl group-containing vinyl chloride-vinyl acetate-acrylic ester copolymer, polyvinylidene chloride, maleic acid-containing vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinylidene chloride copolymer , vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-methacrylic acid ester copolymer, phenoxy resin, nitrocellulose, nitrified cotton, ketone resin, acrylic acid or methacrylic acid polymer or copolymer, acrylic acid ester or methacrylic acid ester Polymer or copolymer, polyimide resin, 1°3-pentadiene resin, epoxidized 1,3-pentadiene resin, hydroxylated 1,
3-pentadiene resin, acrylonitrile polymer or copolymer, acrylic ester-acrylonitrile copolymer, methacrylic ester-acrylonitrile copolymer, phenol-formalin resin, phenol-furfural resin, xylene-formalin resin, urea resin, melamine A resin, alkyd resin, acrylonitrile-butadiene styrene copolymer, etc. may be blended.

Note that the viscosity of the radiation-curable paint of the present invention is usually 2,
000 to 40.000 (cps), preferably 4.0
00 to 20,000 (cps), and the solid content concentration is usually 20 to 80% by weight, preferably 30 to 60% by weight.

Examples of the radiation used to cure the radiation-curable paint of the present invention include electron beams, r-rays, neutron beams, β-rays, and X-rays. Among these, electron beams are preferred from the viewpoint of controlling the radiation dose and ease of installing the radiation irradiation device.

The accelerating voltage of the electron beam is preferably 100 to 750 kV,
Particularly preferably, it is 150 to 300 kV, and the irradiation amount is preferably controlled so that the absorbed dose of the coating film is 0.5 to 20 megaland.

When using the radiation-curable paint of the present invention as a magnetic paint, r-FezO1, F
e5Oa, r-FetOs and Fe, 0. iron oxide in the intermediate oxidation state, Co-containing r-FetOs, Co-containing F
e5On, iron oxide in an oxidation state intermediate between Co-containing r-FezO1 and Fe30a, the above iron oxide further containing a metal element such as a reduced metal element, the above iron oxide containing Co oxide or hydroxide. Those with a coating layer mainly formed on them, those with a CrzOs layer formed by reducing the surface of CrO Crag, metals such as F13SCO and Ni, or alloys thereof, or metals such as metal elements or reduction metal elements on these. Magnetic powder, such as one containing elements, is usually added in an amount of 75 to 85% by weight based on the radiation-curable coating material of the present invention.
Arrange and use.

Furthermore, in addition to the above magnetic powder, additives such as lubricants such as soybean oil lecithin and silicone oil may be used.

The radiation-curable coating material of the present invention can be applied particularly as a magnetic coating material to a coated material (substrate: base film), such as polyesters such as polyethylene terephthalate; polyolefins such as polypropylene; cellulose derivatives such as cellulose triacetate and cellulose diacetate; polycarbonate; Vinyl chloride: polyimide; non-magnetic metals such as aluminum and copper; coated on paper, etc., subjected to magnetic field orientation treatment, dried, and then irradiated with radiation as described above to harden the magnetic paint film, resulting in excellent magnetic properties. A recording medium can be produced.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to synthesis examples and examples, but the present invention is not limited to these examples.

In addition, in the following synthesis examples, the molecular weight is the value determined by the osmotic pressure method, and the content of phosphorus-containing groups in the polymer is the value measured by the lymphatomolybdic acid method. The structure of the compound can also be determined by its infrared absorption spectrum and nuclear magnetic resonance (
This is the result of analysis by NMR) spectrum.

Synthesis Example 1 A flask with a capacity of 11 equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel was charged with 70.7 g of dicyclohexylmethane diisocyanate, 0.2 g of n-butyltin laurate, 150 g of methyl ethyl ketone, and 150 g of cyclohexanone. , while keeping warm at 60'C.
From the dropping funnel, 215.8 g of polyester diol (Nipporan 4009 manufactured by Nippon Polyurethane Co., Ltd.) and a phosphorous diol compound represented by the following formula (FC manufactured by Asahi Denka Kogyo Co., Ltd.) were added.
450) was added dropwise. After the dropwise addition was completed, the mixture was stirred at 60°C for 4 hours. Thereafter, 6.3 g of hydroxyethyl acrylate was added, and the mixture was further reacted at 60'C for 4 hours to obtain polyurethane I. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

The molecular weight of polyurethane 1 and the content of the phosphorus-containing structure represented by the general formula (i) in polyurethane 1 were measured.
Shown in the table.

Synthesis Example 2 In Synthesis Example 1, polyether diol (PTMG100O manufactured by Mitsubishi Kasei) was used instead of polyester diol.
Using 9.6 g, the amount of phosphorus diol-containing compound used was 0.
．． 09 g, mainly a compound represented by the following formula (hereinafter referred to as "specific hydroxyl compound")
15.6 g of the mixture was used for dropping,
Also, the amount of hydroxyethyl acrylate used was 6.1g.
Polyurethane 2 was obtained in the same manner as in Synthesis Example 1, except that . In addition, the above-mentioned specific hydroxyl compound can be measured with a thermometer,
In a flask with a capacity of IIl equipped with a stirrer and a reflux condenser, 144 g of acrylic acid and bisphenol A diglycidyl ether (Epicor, manufactured by Yuka Shell Epoxy Co., Ltd.) 82B were added.
) was obtained by adding 336 g and reacting at 60° C. for 6 hours.

Table 1 shows the measurement results of the molecular weight of polyurethane 2 and the content of the phosphorus-containing structure represented by the general formula (i).

Synthesis Example 3 In Synthesis Example 1, the amount of dicyclohexylmethane diisocyanate used was 134.4 g, and 64.1 g of polycaprolactone diol (Plaxel 20, manufactured by Daicel Chemical Industries, Ltd.) was used instead of polyester diol.
Polyurethane 3 was synthesized in the same manner as in Synthesis Example, except that a mixture in which the amount of the phosphorus diol-containing compound used was 86.6 g was used for dropping, and the amount of hydroxyethyl acrylate used was changed to 14.9 g. .

Table 1 shows the measurement results of the molecular weight of polyurethane 3 and the content of the phosphorus-containing structure represented by the general formula (i).

Synthesis Example 4 In Synthesis Example 1, 2,6-toluene diisocyanate 99 was used instead of dicyclohexylmethane diisocyanate.
．． Using 2g of polyether diol (PPG400 manufactured by Mitsui Nisso Urethane) 1 instead of polyester diol
42.6 g was used, the amount of phosphorus diol-containing compound used was 9.6 g, and polyoxyethylene bisphenol A ether (DA-350F manufactured by Nippon Oil JIW) 32
．． Polyurethane 4 was synthesized in the same manner as in Synthesis Example 1, except that the mixture to which 1 g of hydroxyethyl acrylate was added was used for the dropwise addition, and the amount of hydroxyethyl acrylate used was changed to 16.5 g.

Table 1 shows the measurement results of the molecular weight of polyurethane 4 and the content of phosphorus-containing groups represented by the general formula (i).

Synthesis Example 5 66.9 g of 2.6-toluene diisocyanate and 0.2 g of n-butyltin laurate were placed in a 21-capacity flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel.
, 150 g of methyl ethyl ketone and 150 g of cyclohexanone were charged, and while keeping the temperature at 60'C, 150.4 g of polyester diol (Nipporan 4002 manufactured by Nippon Polyurethane) and 150.4 g of polyoxyethylene bisphenol A ether (NOF type D^350) were added.
F) 20.1 g, 30.1 g of the same specific hydroxyl compound as in Synthesis Example 2, and the following formula [wherein R' is a residue of polyethylene glycol (average molecular weight 400) excluding the hydroxyl groups at both ends; , n is 1.1. ] The compound represented by (hereinafter referred to as [specific sulfonic acid compound]
), 10 g of polyethylene glycol (molecular weight 4
00) 4.5g and a phosphorus diol compound represented by the following formula (Mopil chemical type P
A mixture with 9.9 g of EGACOL82) was added dropwise.

After the dropwise addition was completed, the mixture was stirred at 60°C for 4 hours. After that, 7.8g of hydroxyethyl acrylate was added and the temperature was further increased to 60°C.
After reacting for 2 hours, 4.9 g of a tetrahydric alcohol compound (adequodrol manufactured by Asahi Denka) was added and reacted at 60° C. for 4 hours to synthesize polyurethane 5. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

The above specific sulfonic acid compound was prepared by adding 74 ml of 5-sodium-sulfo-isophthalic acid dimethyl ester to a flask with a capacity of 11 equipped with a thermometer, a stirrer, and a reflux condenser.
g1 polyethylene glycol (average molecular weight 40Q) 4
It is obtained by adding QQg and 1.0 g of sodium acetate and reacting at 130°C for 6 hours, and contains 45% by weight of unreacted polyethylene glycol.

The molecular weight of polyurethane 5 and the content of the phosphorus-containing structure represented by general formula (ii): C1+3 C113CH:1 in polyurethane 5 were measured in the first
Shown in the table.

Synthesis Example 6 In a flask with a capacity of 21 equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel, 4. ．． 98.3 g of 4'-diphenylmethane diisocyanate, 0.2 g of n-butyltin laurate, 150 g of methyl ethyl ketone, and 150 g of cyclohexanone were charged, and while keeping the temperature at 60°C, polyether diol (Teracol 650 manufactured by DuPont) 102 was added through the dropping funnel. .2g and polyoxyethylene bisphenol A ether (NOF type DA350
) A mixture of 57.8 g and 1.1 g of the same phosphorus diol-containing compound as in Synthesis Example 5 was added dropwise. After dropping, 60℃
The mixture was stirred for 4 hours. Thereafter, 10.6 g of pentaerythritol triacrylate was added, and the mixture was further reacted at 60° C. for 2 hours with stirring.

Next, the residues of the following formula (% Formula %) (manufactured by Teracol 650) from which the hydroxyl groups at both ends have been removed are mainly shown. ] Add a methyl ethyl keto solution of 29.9 g of a compound consisting of (hereinafter referred to as "specific carboxyl compound"),
Polyurethane 6 was synthesized by reacting at ℃ for 7 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

The above specific carboxyl compound was prepared by adding 43.6 g of pyromellitic dianhydride and 500 g of methyl ethyl ketone to a flask with a capacity of 11 equipped with a thermometer, stirrer, reflux condenser, and dropping funnel, and heating the mixture to 60°C. After dissolving pyromellitic dianhydride, the temperature was raised to 70°C, and then 195 g of polyether diol (Terakol 650 manufactured by DuPont) was slowly added dropwise from the dropping funnel, and after the addition was completed, the temperature was raised to 70°C. It was obtained by reacting for a period of time.

Table 1 shows the results of measuring the molecular weight of polyurethane 6 and the content of the phosphorus-containing structure represented by the general formula (ii) in polyurethane 6.

Synthesis Example 7 In a 121-volume flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel, 60.2 g of 2.4-1-ruene diisocyanate) and 0.2 n-butyltin laurate were added.
g, 150 g of methyl ethyl ketone and 150 g of cyclohexanone were charged, and while keeping the temperature at 60°C, 174.9 g of polyester diol (Nipporan 4009 manufactured by Nippon Polyurethane) and 174.9 g of polyoxyethylene bisphenol A ether (NOF type D^350) were added.
F) 36.2 g, 21.0 g of the same specific hydroxyl compound as in Synthesis Example 2, 5.3 g of the sulfonic acid compound with the same characteristics as in Synthesis Example 5, and 0.5 g of the same phosphorus diol compound as in Synthesis Example 6. The mixture was added dropwise. After dropping, 60℃
The mixture was stirred for 2 hours. Thereafter, 2.0 g of hydroxyethyl acrylate was added, and the mixture was further reacted at 60° C. for 1 hour to synthesize polyurethane 7. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

Table 1 shows the results of measuring the molecular weight of polyurethane 7 and the content of the phosphorus-containing structure represented by the general formula (ii) in polyurethane 7.

Synthesis Example 8 A flask with a capacity of 2β equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel was charged with 78.2 g of dicyclohexylmethane diisocyanate, 0.2 g of n-butyltin laurate, 150 g of methyl ethyl ketone, and 150 g of cyclohexanone. While keeping the temperature at ℃, 149.2 g of polyether diol (pPG1000 manufactured by Mitsui Nisso Urethane) and polycaprolactone diol (Plaxel 205 manufactured by Daicel Chemical Industries, Ltd.) were added through a dropping funnel.
), 14.3 g of the same specific hydroxyl compound as in Synthesis Example 2, and 3.2 g of the phosphorous diol-containing compound as in Synthesis Example 1 was added dropwise.

After the dropwise addition was completed, the mixture was stirred at 60°C for 4 hours. Then, 1.4g of hydroxyethyl acrylate was added and an additional 60g of
Polyurethane 8 was synthesized by reacting at ℃ for 2 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

Table 1 shows the results of measuring the molecular weight of polyurethane 8 and the content of the phosphorus-containing structure represented by the general formula (i) in polyurethane 8.

Synthesis Example 9 Into a 2β flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel, 116.6 g of dicyclohexylmethane diisocyanate and 0 n-butyltin laurate were added.
．． 2g of polyester diol (Nisoporan 4009 manufactured by Nippon Polyurethane) and 74.1g of polyoxyethylene bisphenol A ether (NOF type DA350F) were added through a dropping funnel while keeping the temperature at 60°C.
) and 8.0 g of the same phosphorus diol-containing compound as in Synthesis Example 1 was added dropwise. After dropping, 60℃
The mixture was stirred for 4 hours.

Thereafter, 3.4 g of hydroxyethyl acrylate was added, and the mixture was further reacted at 60° C. for 2 hours to synthesize polyurethane 9. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate M remained in the reaction system.

Table 1 shows the results of measuring the molecular weight of polyurethane 9 and the content of the phosphorus-containing structure represented by the general formula (I) in polyurethane 9.

Synthesis Example 10 In a 21-capacity flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel, 77.8 g of dicyclohexylmethane diisocyanate and 0 n-butyltin laurate were added.
．． 2g of methyl ethyl ketone, 150g of cyclohexanone, and 150g of cyclohexanone.
G100O) 170.0 g and polyoxyethylene bisphenol A ether (NOF type DA350F)
A mixture of 10.0 g of the same specific hydroxyl compound as in Synthesis Example 2, and 11.0 g of the same phosphorous diol compound as in Synthesis Example 6 was added dropwise. After completion of dripping, 60
The mixture was stirred at ℃ for 4 hours. Thereafter, 0.9 g of hydroxyethyl acrylate was added, and the mixture was further reacted at 60° C. for 2 hours to synthesize polyurethane 10.

After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate M remained in the reaction system.

Table 1 shows the results of measuring the molecular weight of polyurethane 10 and the content of the phosphorus-containing structure represented by the general formula (ii) in polyurethane 10.

Synthesis Example 11 A ft2I2 flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel was charged with 107.4 g of dicyclohexylmethane diisocyanate, 0.2 g of n-butyltin laurate, 150 g of methyl ethyl ketone, and 150 g of cyclohexanone. While keeping the temperature at 60°C, 91.1 g of polyester diol (Nipporan 4002 manufactured by Nippon Polyurethane) and polyoxyethylene bisphenol A ether (NOF type 0A) were added through the dropping funnel.
A mixture of 62.9 g of 350F), 21.9 g of the same specific hydroxyl compound as in Synthesis Example 2, and 9.8 g of the same phosphorous diol compound as in Synthesis Example 1 was added dropwise. after that,
After adding 4.2 g of hydroxyethyl acrylate and further reacting at 60°C for 2 hours, 2.7 g of a tetrahydric alcohol compound (Adeka Quadrol manufactured by Asahi Denka) was added and the mixture was heated to 60°C.
The reaction was carried out at ℃ for 4 hours to synthesize polyurethane 11. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the reaction system.

Table 1 shows the results of measuring the molecular weight of Polyushituff 110 and the content of the phosphorus-containing structure represented by the general formula (i) in polyurethane 11.

Preparation 11 and Evaluation Example 1 A magnetic paint having the following composition was prepared in the following manner using the cyclohexanone-methyl ethyl ketone mixed solution of polyurethane 1 obtained in Synthesis Example 1, and it was applied to a substrate and exposed to electrons. It was cured by radiation.

Co-containing r-Fe, 0.80 parts by weight Polyurethane 1 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight of the magnetic powder having the above composition, a mixed solvent of cyclohexanone and metholethyl ketone, and about 20 ml of 3 mm stainless steel pole were placed in a 500 ml aluminum can, and the mixture was shaken for 2 hours using a paint conditioner manufactured by Red Devil, USA. Next, a cyclohexanone-methyl ethyl ketone mixed solution of polyurethane 1 was added, and after further shaking for 4 hours, the stainless steel pole was removed to obtain a magnetic paint. A magnetic paint was applied, immediately subjected to magnetic field orientation treatment, and dried overnight at room temperature. Thereafter, the coating film was cured by irradiating the coating film with an electron beam using an electrocurtain type electron beam accelerator at an acceleration voltage of 160 kilovolts and an absorbed dose of 7 Megaland to obtain a magnetic cured coating film.

Separately, a paint having the same composition as the above magnetic paint composition except for excluding the magnetic powder was coated on a glass plate and a polyester film so that the dry film thickness of polyurethane 1 was 40 to 60 μm, and overnight at room temperature. After drying, the coating film was cured by irradiating the coating film with an electron beam at an accelerating voltage of 160 kilovolts and an absorbed dose of 5 megarads to form a nonmagnetic cured coating film.

In order to evaluate the various properties of the obtained magnetic cured coating film and non-magnetic cured coating film, the following tests (11 to (8)) were conducted. The extraction residue test (7) was conducted using a non-magnetic cured coating formed on the glass film described above, and a bending test (
Test 8) was conducted using a transparent cured thin film coated on a polyester film together with the polyester film, and all other tests +11 to (5) were conducted on the magnetic cured coating.

(1) Gloss: Measure the gloss of the cured magnetic coating film at a reflection angle of 45° using a digital gloss needle (Murakami Color Technology Research Fragment), and when the gloss is 70 to 90, ◎, and 50 to 70. ○, cases of 30 to 50 were evaluated as Δ, and cases of 30 or less were evaluated as ×.

(2) Surface observation: Observe the surface of the cured magnetic coating using a scanning electron microscope. ○ indicates a state in which some aggregation is observed in the crab, Δ indicates a state in which some agglutination is observed in all of the test samples, and Δ indicates a state in which aggregation is observed over the entire surface of all test samples. Rated as ×.

(3) Adhesion test: Adhesive tape is pasted on the surface of the cured magnetic coating, and after adhering uniformly to the entire surface, the condition is observed when the cured magnetic coating is peeled off instantly. The evaluation was rated as × when complete peeling was observed, △ when slight peeling was observed, ◯ when hardly peeled off, and ◎ when no peeling was observed.

(4) Actual running durability: 12,'
A magnetic tape was prepared by cutting it into hmO width. Based on the VHS videotape standard, a 50% gray signal was recorded on a magnetic tape through a VTR, and then the magnetic tape was run for 2 hours under the conditions of 40°C and 80% RH while measuring the playback output. The number of repetitions until the playback output of the tape became less than half of the initial output was measured.

(5) Square ratio (Br/8m): VSM- manufactured by Toei Kogyo KK
Magnetic properties were measured using a type 3 with an external magnetic field of 5.0000 e. (Br = residual magnetic flux density, Bm = maximum residual magnetic flux density) (6) Breaking strength, elongation, initial modulus: A strip-shaped test piece (0.5 cm x 10 cm x
40-60μm) and cut out 50m/llll at room temperature.
Measurements were made at a tensile speed of 1n.

(7) Tetrahydrofuran (THF) extraction residue: The cured coating film was subjected to THF Soxhlet extraction for 24 hours,
The percentage of extraction residue was measured.

(8) Cut the entire polyester film of the substrate into strips with a width of 1 cm, fix both ends and bend from the center, then immediately restore to the original state 20 times per second, and cure transparent at the bent part. It was observed whether the paint film peeled or broke. Those that withstood flexing for 500 hours were rated as excellent, and those that withstood 400 hours of flexing were rated as good.

Examples 2 to 11 In each example, a magnetic cured coating film was obtained in the same manner as in Example 1 except that a magnetic coating material having the following composition was used. Further, a non-magnetic cured coating film was formed on a glass plate in the same manner as in Example 1 using a coating material having the same composition except that it did not contain magnetic powder.

The magnetic properties of the obtained magnetic cured coating film and non-magnetic cured coating film were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Set of stone Ringuruma 2 Magnetic paint of Example 2 containing Co -Fezes 80 parts by weight Polyurethane 2 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone 200 parts by weight Magnetic paint of Example 3 containing CO FezO380 Parts by weight Polyurethane 3 17 parts by weight (solid content equivalent) Pentaerythritol triacrylate 3 parts by weight Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Magnetic paint of Example 4 containing Co r -FezO = 80 parts by weight Polyurethane 4 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Magnetic paint of Example 5 Co-containing r FezO3ao parts by weight Polyurethane 5 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Magnetic paint of Example 6 Co-containing T FezO: + 80 parts by weight Polyurethane 6 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Magnetic paint of Example 7 Co-containing r FezO 180 parts by weight Polyurethane 7 20 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Magnetic paint Co-containing r-F+ of Example 8, 0.80 parts by weight Polyurethane 8 20 parts by weight (in terms of solid content) Solvent for consolidating cyclohexanone and methyl ethyl ketone
200 parts by weight Co-containing magnetic paint of Example 9 T FezOa 80 parts by weight Polyurethane 9 17 parts by weight (in terms of solid content) Pentaerythritol triacrylate 3 parts by weight Mixed solvent of cyclohexanone and methyl ethyl ketone
20O 7iit parts Magnetic paint of Example 10 Co-containing T Feze 38o parts by weight Polyurethane 1020 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Co-containing magnetic paint of Example 11 FezCh 80 parts by weight Polyurethane 1120 parts by weight (in terms of solid content) Mixed solvent of cyclohexanone and methyl ethyl ketone
200 parts by weight Comparative Example 1 In Synthesis Example 1, dicyclohexylmethane diisocyanate was used as 82.9 g, a compound represented by the general formula (iii) was used as the phosphorous diol compound, hydroxyethyl acrylate was changed as 7.3 g, and hydroxyethyl acrylate was added as 7.3 g. Polyurethane 12 was obtained in the same manner as in Synthesis Example 1 except that the reaction time after addition was 2 hours.

The results of measuring the molecular weight of polyurethane 12 and the content of the phosphorus-containing structure represented by the formula in polyurethane 12 are
Shown in the table.

Further, a test was conducted in the same manner as in Example 1 using the obtained polyurethane 12. The results are shown in Table 2.

Table 1 〔Effect of the invention〕 The present invention has the following effects.

(11) When the radiation-curable paint of the present invention is used as a magnetic paint, a magnetic recording medium with excellent actual running durability and electromagnetic conversion characteristics can be obtained.

(2) When the radiation-curable paint of the present invention is used as a magnetic paint, a magnetic recording medium with a high magnetic powder filling rate and excellent surface smoothness can be obtained.

(3) The radiation-curable paint of the present invention has an increased pot life and, when used as a magnetic paint, provides a magnetic recording medium with excellent running durability.

(4) The cured coating film of the radiation-curable paint of the present invention is not only excellent in mechanical properties, but also excellent in adhesiveness to substrates such as magnetic recording media.

(5) The radiation-curable paint of the present invention has excellent cross-linking properties upon radiation irradiation, so that it can be sufficiently cross-linked and cured with a low radiation dose, and a cured coating film with excellent solvent resistance can be obtained. The energy required to cure the film can be reduced.

(6) When the radiation-curable paint of the present invention is used as a magnetic paint, it has extremely good affinity with the magnetic powder blended, and the magnetic powder can be easily dispersed into the paint. The blending ratio of magnetic powder can be significantly improved. Therefore, the radiation-curable coating material of the present invention can be used to prepare a magnetic coating material that can produce a magnetic recording medium with excellent magnetic conversion characteristics.

(7) Even if the coating film of the radiation-curable paint of the present invention improves the crosslinking density by increasing the radiation dose,
A cured coating film with appropriate flexibility and surface hardness can be obtained, and when used as a magnetic coating in the production of magnetic tape, which is a type of magnetic recording medium, it has good contact with the magnetic head. Therefore, it is possible to obtain a highly durable magnetic tape with less magnetic powder falling off and less modulation noise.

Claims (1)

[Claims] The following general formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
(I) [In the formula, R^1 and R^2 may be the same or different, and each is an alkyl group of C_1 to C_2_0;
R^3 is an alkylene group of C_1 to C_6; R^
4 and R^5 may be the same or different and are each an alkylene group of C_2 to C_1_0; n and l
may be the same or different, each being a number from 0 to 19. ] The phosphorus-containing structure represented by and the following general formula (II): ▲Mathematical formulas, chemical formulas, tables, etc. are available▼・・・・・・・・・
(II) [Here, R^6 is the same as R^1 and R^2, R^7 and R^8 are the same as R^4 and R^5; m and p are Same as n and l. ] A radiation-curable paint containing a polyurethane having at least one type selected from the phosphorus-containing structure represented by 10^-^7 to 10^-^3 mol per gram of polyurethane and having a radiation-polymerizable double bond. .