JPH01204973A - Radiation curable paint - Google Patents

Abstract

PURPOSE: To give good dispersibility to magnetic powder and to produce magnetic record medium having good actual running durability under wide use conditions by incorporating a nitrile group and a double bond for radiation polymerization into a polyurethane.

CONSTITUTION: This coating material is prepared by contg. a polyurethane having nitrile group and radiation-polymerisable double bond as a resin component. The polyurethane is prepared by allowing diisocyanate such as 2,4- toluenediisocyanate, etc., to react with as polyester diol obtained from adipic acid and butanediol as a diol component, a acrylic acid adduct to a polyoxyethylene bisphenol A ether or biphenol A propyleneoxide derivative as a hydroxy compd., the reaction product of diethanol-amine and acrylonitrile as a nitrile group addition compd. and 2-hydroxyethylacrylate, etc., as a double bond addition compd.

COPYRIGHT: (C)1989,JPO

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 a coating film of radiation-curable magnetic paints made by mixing this with magnetic powder, solvents, etc., has been cured by radiation irradiation. There are known ways to do this.

In such radiation-curable paints, radiation-curable polyurethane resins containing hydrophilic polar groups such as carboxylic acid groups, sulfonic acid groups, phosphate ester groups, and sulfonium groups are used to improve the dispersion performance of magnetic powder. (Japanese Patent Application Laid-Open No. 57-92421). On the other hand, there is also a magnetic paint comprising a polymer containing a nitrile group, one of which is an acrylonitrile polymer, and a polyurethane resin. Known (Japanese Patent Application Laid-Open No. 51-519
No. 06, JP-A-51-65905, JP-A-5
1-118403, JP-A-58-117263).

[Problems to be Solved by the Invention] However, the magnetic recording medium using the resin described in the above patent has poor actual running durability under temperature cycles (-10°C to 40°C) and high temperature (50°C). C., 90% relative humidity) and low temperatures (-10.degree. C.). Furthermore, the dispersion performance of the magnetic powder is not fully satisfactory.

The purpose of the present invention is to have excellent dispersion performance for magnetic powder, as well as excellent actual running durability at room temperature, as well as under high temperature and high humidity (50°C, 90% relative humidity) and low temperature (-10℃), and further temperature cycle conditions (-
The object of the present invention is to provide a radiation-curable coating material that provides a magnetic recording medium with excellent actual running durability under a wide range of use environments such as temperatures below 10°C to 40°C.

Still another object of the present invention is to provide a magnetic coating with good adhesion and excellent mechanical strength for polyester films that are commonly used as substrate films for magnetic recording media such as magnetic tapes and floppy disks. An object of the present invention is to provide a radiation-curable coating material that provides a magnetic recording medium having a film.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a radiation-curable paint containing a polyurethane having a nitrile group and a radiation-polymerizable double bond. It is something.

The polyurethane used in the present invention contains a nitrile group, and the nitrile group is represented by the following general formula (1).
and (II) / R3 −It<−N−(:lh(:IIcN (I
I) (wherein, R1 is a hydrogen atom or a C1 to C6 alkyl group such as a methyl group, an ethyl group, a propyl group, and R
2, R3 and R4 are each an alkylene group, alkenylene group, arylene group, cyclic hydrocarbon group, heterocyclic group or group -(OClhCIh)-- or -(OCII C112) n-CI+ having 1 to 20 carbon atoms.

(Here, m and n each represent a number from 1 to 2o)] It is included in the polyurethane by at least one type of nitrile-containing structure represented by the following. R of the above nitrile-containing structure
Among 2, R3 and R4, alkylene groups include methylene group, ethylene group, propylene group, tetramethylene group,
Hexamethylene groups, decamethylene groups, pentadecamethylene groups, etc., arylene groups include groups represented by the following formula, alkenylene groups include groups represented by the following formula %, and cyclic hydrocarbon groups include groups represented by the following formula. What is the group represented by the following formula? Examples of the 11-elementary cyclic group include the groups shown below. Further, in the above nitrile-containing structure, R2, R3 and R4 are alkylene groups having 1 to 3 carbon atoms such as methylene group, ethylene group, propylene group, or groups in which m and n are both 15 or less @OC
112C11z'FfK- or →OCIt CIf
The case of t+-f- is preferable.

C11° Such nitrile groups are usually present in an amount of 1×1 O-' to 5×10-' gram equivalents, preferably 1×10-' to 5×10-' Durham equivalents per gram of polyurethane. The content of nitrile groups is 5X10 per gram of polyurethane
-' If the gram equivalent is exceeded, the solubility in general-purpose solvents used when the radiation-curable paint of the present invention is used as a magnetic paint, such as toluene, methyl ethyl ketone, methyl itubel ketone, etc., tends to decrease; The content of nitrile groups is 1' per gram of polyurethane.
If it is less than X10-' Durham equivalent, the dispersibility of the magnetic material will be insufficient when used as a magnetic coating material, and the magnetic recording properties will tend to deteriorate when used as a magnetic recording medium.

The polyurethane used in the present invention can be manufactured, for example, by the following manufacturing method.

First, in the first step, for example, the following general formula % formula % () [where nl, R2 and R3 are the same as in general formula (I)] is used. ) +10 11 II [wherein 1 and R4 are the same as the general formula (1).

[In the formula, I'lI' is an ethylene group, a propylene group, a tetramethylene group, a pentamethylene group , a C2-C6, preferably 62-C4 alkylene group such as a hexamethylene group, and II2 is -CII 2- CII -CIf -CIt 2-
, -G H-If-(:11, -C-CI
I-.

-ICC11,)T-9→CII t h-,→CII
2 h-.

→CII 2 h-, →CI z hr-, -CyoC-
and q is a number of 1 to 50. ]11G(I
I"0)-r-R"-0ff..."
...(d) [wherein R1+ is general formula (c)
, and S is a number from 1 to 50. ) (where Ill is the same as in general formula (c), and t
and U may be the same or different, each from 1 to 20
is the number of ) [In the formula, 113 is R3 C) ■3'-C112-O-4C112CI12-Oh~C11
2-1-C112-〇-((:+1l-CIl-Q)-
7--C112-1C11゜-C11,-0--→C112C112C112CIl
aO+C112-1 (wherein 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); C6°, preferably C4 to C4S divalent aliphatic group1. It means an alicyclic group or an aromatic group, and as exemplified above, these aliphatic groups, alicyclic groups, and aromatic groups are
In its structure, (114 may have a hydrogen atom, a hydroxyl group, or a substituent such as a methyl group, an ethyl group, a propyl group, a butyl group, an acyl group, a phenyl group, a benzyl group, a cyclohexyl group, a cyclopentyl group, etc.) An aliphatic group, alicyclic group, or aromatic group that may have a substituent such as C1 to Ca aliphatic group, alicyclic group, or aromatic group, and does not contain a petro atom. It's okay to stay. (2) and W may be the same or different, and each is a number from 1 to 2o. ] At least one diol selected from diols represented by
If necessary, for example, the following general formulas (g) to (i) (wherein 15 is a group represented by -(CIhCI120)+c-1 or C)13, X is a number from 1 to 2o, , n@
is a hydrogen atom or a methyl group. ) (In the formula, the first item is
It is the same as the general formula (C), y and 2 may be the same or different, each is a number from 1 to 30, n' is a number from 1 to 5, and M is an alkali such as potassium or sodium. It is metal. ) [In the formula, the Rth is the same as in general formula (c), and S and S' may be the same or different, and each has a value of 1 to 50
and R111 is -CII2-CII- to 112-CII C112
-1 etc. C7~C4°, preferably 62~C7
It is a tetravalent aliphatic group, alicyclic group or aromatic group.

[In the formula, 117 is →C1l□] and at least one diol selected from the following general formula (j): It is a C8 to C20 divalent hydrocarbon group such as h-. ) is reacted with a diisocyanate represented by

In this first step reaction, the diisocyanate represented by formula (J) is combined with the nitrile-containing diol represented by general formula (a), -general formula (b), etc. and general formula (C) -
(1) is used in stoichiometric excess with respect to the total amount of diol, and each reaction component is bonded via a urethane bond to form a polymer having an isocyanate group at the molecular end (hereinafter referred to as r-polymer). 1) is generated.

In addition, in this first step, as a chain extender, aliphatic diamine, alicyclic diamine, aromatic diamine, polyether diamine, etc. may be used. Specific examples of these chain extenders include ethylene diamine, tetra Examples include methylene diamine, hexamethylene diamine, cyclohexyl diamine, paraphenylene diamine, polyoxyethylene diamine, and polypropylene diamine.

Next, in the second step, the polymer A is given, for example, the following general formulas (k) to (m), etc. [where n9 is the same as the general formula (g), RIG is an ethylene group, a propylene group, Indicates a C2-C6 alkylene group such as a hexamethylene group or an octamethylene group, ] CI+2-C(R')-H at C-0-.

■ [In the formula, n9 is the same as m(g) in general. ] (In the formula, n9 is the same as general formula (g).) At least one selected from (meth)acrylates having a hydroxyl group represented by By reacting in substantially equivalent amounts, a polyurethane can be obtained in which a structure having a radiation-polymerizable double bond is bonded to the molecular terminal of the polymer A via a urethane bond.

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

First, a (meth)acrylate having a hydroxyl group represented by the above general formulas (k) to (II+) etc. is reacted with the isocyanate group of the polymer A in a stoichiometrically approximately % equivalent amount to form a polymer. A polymer (hereinafter referred to as "polymer B") in which a structure having a radiation-polymerizable double bond is bonded to one of the two ends of the A molecule via a urethane bond, and an isocyanate group remains at the other end. Next, polymer B is given the following general formula (n): [wherein, Q is,
It is a tetravalent organic group. By reacting the tetrahydric alcohol represented by ], the remaining isocyanate groups of the polymer B can be bonded to the tetrahydric alcohol via a urethane bond, and the polyurethane to be used can also be obtained by this method. .

Furthermore, in the polyurethane used in the present invention, as necessary, a part of the (meth)acrylic double bonds in the polymer chain is added to the (meth)acrylic double bonds in the polymer chain as a third step. Numerical formula (0): ” (In the formula, R2 and R3 are the same as in general formula (1).

) A secondary amine represented by can also be added.

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 have a total amount of starting materials used in the first step, too.
It is preferable to use about 0.01 to 1 part by weight per i part.

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 polymer A1001
It is preferably used in an amount of 0.0, 1 to t per part.

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,
Examples include methyl ethyl ketone, cyclohexanone, tetrahydrofuran, toluene, methyl isobutyl ketone, and dioxane.

Furthermore, the polyurethane used in the present invention can also be produced by carrying out these reactions all at once, without carrying out the first and second steps separately as described above.

The general formula used in the above polyurethane manufacturing method (
The ratio of the nitrile-containing diol represented by a), (b), etc. is usually 0. O1～
The amount is 751 to 75% by weight, or 0.01 to 50% by weight.

Further, the proportion of (meth)acrylate having a hydroxyl group represented by general formulas (k) to (m) used in the above polyurethane production method is preferably 0.2 to 40% by weight based on the polyurethane obtained. '%, particularly preferably from 0.5 to 30% by weight. If the amount of (meth)acrylate exceeds 40 TIL, the coating film cured by radiation loses flexibility and the mechanical properties of the coating film are likely to be impaired. On the other hand, if (meth)acrylate is less than 0.21i% of polyurethane, the coating film will not be sufficiently cured by radiation, and its actual running durability may decrease when used as a magnetic paint. .

In addition, in the above production method, when using diols represented by formulas (C) to (f), etc., the proportion of their use is preferably 20 to 9
5% melon amount, particularly preferably 25-90! ! The amount is %.

In the above production method, when using the diol represented by formula (g), the proportion of its use is preferably 30% by weight or less, particularly preferably 20T1% by weight or less, based on the polyurethane obtained. If the proportion exceeds 30% by weight, the flexibility of the coating film cured by radiation will be impaired.

In the above method for producing polyurethane, when diols represented by formulas (h) and (1) are used, the total amount used is preferably 20i% or less, particularly preferably tog%, based on the polyurethane obtained. If the usage ratio exceeds 20% by weight, the polarity of the polyurethane obtained will increase, the solubility in general-purpose solvents such as toluene and methyl ethyl ketone will decrease, and the coating film cured by radiation will deteriorate. Hygroscopicity increases and the strength of the coating film tends to decrease.

In the production of the above polyurethane, when the compound represented by the general formula (0) is used in the third step, the proportion used is 95% equivalent to the (meth)acrylic double bond group contained in the polymer chain. Below, particularly preferably 9
If the proportion used exceeds 95% equivalent, the resulting polyurethane will have insufficient curability.

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

-Nitrile-containing diols represented by formula (a) include monoethanolamine, jetanolamine, diisopropanolamine, 2-amino-2methylpropanol, 5-amino-1-pentanol, etc. Mention may be made of reaction products with acrylonitrile.

Examples of the nitrile-containing diol represented by the general formula (b) include a reaction product of a compound having one hydroxyl group and one primary amino group in the molecule and (meth)acrylonitrile. Examples of such compounds having one hydroxyl group and one primary amino group in the molecule include monoethanolamine, aminopropanol, D,L-alaninol, 2-aminobutyl alcohol, and 2-amino-2methylpropanol. Tool, 5-amino-1-pentanol, 0
-aminophenethyl alcohol, p-amino-phenethyl alcohol, 0-aminophenol, m-aminophenol, p-aminophenol, 3-amino-1-propanol, monobutanolamine, α-ethyl-3-hydroxy-4-methyl Phenethylamine, 3-fluoro-D, L-tyrosine, D, L-homoserine, L-isoleucinol, D(-)-α-phenylglycitur, D
, L-3-phenylserine and the like.

Examples of the diol represented by the general formula (C) include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1.6-hexanediol, neopentyl glycol, and 1.4-cyclohexanediol. Examples include polyester diols obtained by reacting polyhydric alcohols such as metatool with polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, and sepatic acid.

Examples of the diol represented by the general formula (d) include polyether diols such as polyethylene glycol, polypropylene glycol, and polytetralamethylene glycol.

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

Examples of the diol represented by the general formula (f) include polycaprolactone diol obtained by a ring-opening reaction of ε-caprolactone.

As the diol represented by the general formula (g), a (meth)acrylic compound having a carboxyl group and a (meth)acrylic compound having a hydroxyl group are used per mole of a jepoxy compound containing two epoxy groups in one molecule. Examples include diols synthesized by reacting at least one mole of at least one fill of compounds selected from the following.

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 diol represented by the general formula (h) include diols synthesized by reacting the polyether diol represented by the above general formula (d) with sulfoisophthalic acids. Examples of the sulfoisophthalic acids include 5-sodium-sulfo-isophthalic acid, 5-potassium-sulfo-isophthalic acid, 5-sodium-sulfo-isophthalic anhydride, di-lower alkyl 5-sodium-sulfo-isophthalate, Examples include di-lower alkyl 5-potassium-sulfo-isophthalate.

-n2 The diol represented by formula (i) can be esterified or amidated by reacting less than 1 mol of tetracarboxylic dianhydride with 1 mol of polyether diol represented by general formula (d) above. Examples include diols synthesized by

As the diisocyanate represented by general formula (J),
z, 4-toluene diisocyanate, 2.8-toluene diisocyanate, 1.3-xylene diisocyanate, 1.4-xylene diisocyanate, l, 5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3.3' -
Dimethyl-4,4'-diphenylmethane diisocyanate, 4.4'-diphenylmethane diisocyanate, 3.3'-dimethylphenylene diisocyanate, 4.4'-biphenylene diisocyanate, hexamethylene diisocyanate, inlon diisocyanate, dicyclohexylmethane diisocyanate, etc. .

Examples of the (meth)acrylate having a hydroxyl group represented by the general formula (k) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate.

Examples of the (meth)acrylate having a hydroxyl group represented by the general formula (1) include glycerin di(meth)acrylate.

As the (meth)acrylate having a hydroxyl group represented by the general formula (m), pentaerythritol tri(meth)
Examples include acrylate.

- As a tetrahydric alcohol represented by Noshiro (n),
Pentaerythritol, N, N, N', N'-tetrahydroxypropylethylenediamine, ethylenethia
Examples include amine alkylene oxide adducts and diglycerin alkylene oxide adducts.

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 to this.
It is not something that will be done.

The molecular weight of the polyurethane used in the present invention is usually 2
．． OQO~too,ooo, preferably 4.000~
60,000. If this molecular weight is less than 2,000, the strength of the coating film cured by radiation tends to decrease, and if the molecular weight exceeds 0,000, the viscosity of the solution increases and it becomes difficult to handle when preparing the paint. In addition, especially when preparing a magnetic coating, a large amount of solvent is required to reduce the viscosity, which is uneconomical.

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 contain a polymer having a radiation-polymerizable double bond and/or a monomer having a radiation-polymerizable double bond other than the polyurethane used in the present invention, if necessary. can.

Furthermore, in addition to the above-mentioned polyurethane, the radiation-curable coating material of the present invention may optionally include polyvinyl butyral, polyvinyl acetal, other polyurethanes, polyesters, polyesters containing sulfonic acid and/or sulfonic acid metal salts, epoxy resins, and epoxy urethanes. 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 acid 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 Combined, phenoxy resin,
Nitrocellulose, nitrified cotton, ketone resin, (meth)acrylic acid polymer or copolymer, (meth)acrylic acid ester polymer or copolymer, polyimide resin, 1.3-
Pentadiene resin, epoxidized 1,3-pentadiene resin, hydroxylated 1,3-pentadiene resin, (meth)acrylonitrile polymer or copolymer, (meth)acrylic acid ester-acrylonitrile copolymer, phenol-formalin resin, phenol - Furfural resin, xylene-formalin resin, urea resin, melamine 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 1,
000-50,000 (cps), preferably 2.0
00 to 30,000 (cps), and the solid content concentration is usually 20 to 80!1% 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, γ-rays, neutron beams, and β-rays.
- rays, X-rays, etc. Among these, electron beams are preferred from the viewpoint of controlling the radiation dose and ease of installing the radiation irradiation device. The acceleration voltage of the electron beam is preferably 10
It is 0 to 750 kV, particularly preferably 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 megarads.

When using the radiation-curable paint of the present invention as a magnetic paint, the radiation-curable paint of the present invention may include 1'-Fe20i.
% Fe=04.7- Iron oxide with an oxidation state intermediate between Fe2e3 and Fe3O4, containing CO-Fe203, C
OO Fe5O4, Go gold containing y -Fe, O, and Fe
* Iron oxide in an oxidation state intermediate to 04, the iron oxide roughly containing a metal element such as a reduced metal element, and a coating layer mainly composed of Go oxide or hydroxide formed on the iron oxide. (: rO2, CrO2 surface reduced to form a Cr2O3 layer, Fe.

(:o, Metals such as Ni, alloys thereof, metal elements such as metal elements or transition metal elements, and magnetic powders such as barium ferrite are usually added to the radiation-curable paint of the present invention. , 75-85% by weight
Mix and use.

Furthermore, in addition to the magnetic powder described above, a lubricant such as soybean oil lecithin or silicone oil may be used.

The radiation-curable coating material of the present invention can be particularly used as a magnetic coating material (substrate: base film) such as a polyester such as polyethylene terephthalate; a polyolefin such as polypropylene; a cellulose conductor such as cellulose triacetate or cellulose diacetate; polycarbonate; Polyvinyl chloride; Polyimide: Non-magnetic metals such as aluminum and copper; Excellent magnetic recording media made by coating paper, etc., subjecting it to magnetic field orientation treatment, drying it, and then irradiating it with radiation to harden the magnetic paint film. can be created.

[Examples] 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 a value determined by an osmotic pressure method.

Synthesis Example 1 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
110.5 g of 2.4-toluene diisocyanate, 1.2 g of dibutyltin dilaurate, and a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio: 50:
50) After adding 200 g and heating to 60°C, adipic acid and butanediol are reacted while being careful not to raise the temperature of the system through the dropping funnel.
9) (hereinafter referred to as "polyester diol (I)") 123.5 g, polyoxyethylene bisphenol A ether (manufactured by NOF Corporation, D8-350F) 1
15.6 g, acrylic acid adduct of bisphenol A propylene oxide conductor (manufactured by Kyoeisha Yushi Co., Ltd., epoxy ester 3QQ2A: hereinafter referred to as a specific hydroxyl compound (I
), 412.8 g of a reaction product of jetanolamine and acrylonitrile (hereinafter referred to as "specific nitrile compound (■)"), and a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio of 50
: 50) 400g of the mixture was added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours.
- After 2.7 g of hydroxyethyl acrylate was added and the reaction was further carried out at 60° C. for 2 hours, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer obtained in this way was converted into a polymer (
Table 1 shows the molecular weight and nitrile group content of the m-coalescence (A), referred to as A).

Synthesis Example 2 In a flask equipped with a thermometer, a stirrer and a flow condenser, 104.20 2.4-)-luene diisocyanate was added.
After adding 1.2 g of dibutyltin dilaurate and 200 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 40:60) and heating to 60°C, add polyester diol ( 1) 150.30g, polyoxyethylene bisphenol A ether (manufactured by NOF Corporation, D8-350F) 35.0g, specific hydroxyl compound (1) 76.3g, specific nitrile compound (1)
A homogeneous mixture of 31.5 g and 400 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 40:60) was added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours.Next, 2-hydroxyethyl acrylate 2. After the completion of the reaction, in which 7 g was added and the reaction was further carried out at 60° C. for 2 hours, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. Table 1 shows the molecular weight and nitrile group content of the 0 polymer (B), which is the m-combinant thus obtained.

Synthesis Example 3 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
Isophorone diisocyanate 111.0 g 1 dibutyltin dilaurate 1.28 and methyl ethyl ketone 20
After adding 0 g and heating to 60°C, add polytetramethylene glycol (Teratane 650, manufactured by DuPont) 92.
3g, polyoxypropylene bisphenol A ether (manufactured by NOF Corporation, DB-900) 127.8g,
Methacrylic acid adduct of ethylene glycol diglycidyl ether (manufactured by Kyoeisha Yushi Co., Ltd., epoxy ester 40EM
, hereinafter referred to as specific hydroxyl compound (■)) 58.
8g, reaction product of diisopropanolamine and acrylonitrile (hereinafter referred to as [specific nitrile compound (If
) J) and 400 g of methyl ethyl ketone were uniformly mixed, and after the completion of the dropping, 6
7.9 g of 2-hydroxyethyl acrylate (2-hydroxyethyl acrylate) was added to this and reacted for 2 hours at 60°C. After the reaction was completed, infrared absorption spectra showed that there were It was confirmed that there were no remaining. Table 1 shows the molecular weight and nitrile group content of 9 polymers (C) obtained in this way.

Synthesis Example 4 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
82.1 g of isophorone diisocyanate, 1.2 g of dibutyltin dilaurate and 200 g of cyclohexanone
After adding and heating to 60℃, add polytetramethylene glycol (manufactured by Mitsubishi Chemical Industries, Ltd., PTM02000) while being careful not to raise the temperature of the system.
214. Iig, polyoxypropylene bisphenol A ether (DB-400 manufactured by NOF Corporation) 100.2 g
A uniform mixture of 0.2 g of a reaction product of monoethanolamine and acrylonitrile (hereinafter referred to as "specific nitrile compound (ut) J") and 400 g of cyclohexanone was added dropwise, and after the completion of the dropwise addition, the mixture was heated at 60°C. After reacting for 4 hours, 2.9 g of 2-hydroxypropyl methacrylate was added and further reacted at 60°C for 2 hours. After the reaction was completed, infrared absorption spectra showed that no isocyanate groups remained in the system. It was confirmed that the polymer obtained in this way was a hexapolymer (D).
) and the nitrile group content are shown in Table 1.

Synthesis Example 5 In a flask equipped with a thermometer, a stirrer and a reflux condenser,
4.4'-diphenylmethane diisocyanate 140
．． After adding 9 g of dibutyltin dilaurate, 1.2 g of dibutyltin dilaurate, and 200 g of tetrahydrofuran and heating to 60°C, 241. 6 g, a reaction product of monobutanolamine and methacrylate trile (hereinafter referred to as "characteristic nitrile compound (IV) J") 0.02 g, and a homogeneous mixture of 400 g of tetrahydrofuran were added dropwise, and after the completion of the dropwise addition, the mixture was heated at 60°C for 4 hours. This was then reacted with 2-hydroxypropyl methacrylate 11
．． After adding 6 g and reacting at 60°C for 2 hours, 5.9 g of a tetrafunctional alcoholic compound (Adeka Quadrol, manufactured by Asahi Denka Co., Ltd.) was added and reacted at 60°C for 4 hours.
After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system.

The polymer thus obtained is referred to as Polymer (E). Table 1 shows the molecular weight and nitrile group content of the polymer (E).

Synthesis Example 6 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
4.4'-diphenylmethane diisocyanate 128
．． After adding 7 g of dibutyltin dilaurate, 1.2 g of dibutyltin dilaurate, and 200 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:50) and heating to 60°C, add polycaprolactone from the dropping funnel while being careful not to raise the temperature of the system. Diol (manufactured by Daicel Chemical Industries, Ltd., Plaxel 212) 190.7 g, acrylic acid adduct of polypropylene glycol #400 diglycidyl ether (manufactured by Kyoeisha Yushi Co., Ltd., Evolite 400p) (hereinafter referred to as "specific hydroxyl compound (III) J") 29. 9g, specific nitrile compound (IV) 43
．． 78 and 400 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:50) were added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours. 6 Then, 2-hydroxypropyl methacrylate After adding 4.6 g of the mixture and reacting at 60° C. for 2 hours, 2.4 g of tetrafunctional alcoholic product (Adeka Quadrol, manufactured by Asahi Denka Co., Ltd.) was added and reacting at 60° C. for 4 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system.

The polymer thus obtained is referred to as Polymer (F). Table 1 shows the molecular weight and nitrile group content of the polymer (F).

Synthesis Example 7 In a flask equipped with a thermometer, a stirrer and a reflux condenser,
4.4'-dicyclohexylmethane diisocyanate 2
After adding 27.4 g of dibutyltin dilaurate, 1.2 g of dibutyltin dilaurate, and 200 g of cyclohexanone and heating to 60°C, 25.1 g of polyester diol (1), polyoxy Propylene bisphenol A needle (manufactured by NOF Corporation, D-350F) 0.9g, specific hydroxyl compound (1) 20.4g, specific nitrile compound (I
V) A homogeneous mixture of 124.8 g and 400 g of cyclohexanone was added dropwise, and after the dropwise addition was completed, the mixture was heated at 60°C for 4 hours.
1.3 g of 2-hydroxyethyl acrylate was then added to the mixture, and the mixture was further reacted at 60° C. for 2 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system.

Table 1 shows the molecular weight and nitrile group content of In polymer (G), which is the polymer obtained in this way.

Synthesis Example 8 In a flask equipped with a thermometer, a stirrer and a reflux condenser,
4.4'-dicyclohexylmethane diisocyanate 153. Lg, 1.2 g of dibutyltin dilaurate and a mixed solvent of methyl ethyl ketone and cyclohexanone (
After adding 200 g of 70:30 (volume ratio) and heating to 60°C, polyester diol (Japan Polyurethane) obtained by reacting adipic acid and ethylene glycol was added, taking care not to raise the temperature of the system from the dropping funnel. Polyoxypropylene bisphenol A ether (manufactured by NOF Corporation, D
8-400) 169.9g, acrylic acid adduct of propylene glycol diglycidyl ether (manufactured by Kyoeisha Yushi Co., Ltd., referred to as epoxy ester 70P specified hydroxyl compound (+V)) 22.4g, specified nitrile compound (1) 6 ．． :1 g, and a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 70:3
0) A uniform mixture of 400 g was added dropwise, and after the completion of the dropwise addition, the mixture was reacted at 60°C for 4 hours.Next, 1.0 g of 2-hydroxyethyl acrylate was added to this, and further 6
After the reaction was completed at 0° C. for 2 hours, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer obtained in this way is polymer (H).
shall be. Table 1 shows the molecular weight and nitrile group content of the polymer (H).

Synthesis Example 9 In a flask equipped with a thermometer, a stirrer and a reflux condenser,
2.4-) After adding 65.7 g of luene diisocyanate, 1.2 g of dibutyltin dilaurate, and 200 g of cyclohexanone and heating to 60°C, add adipic acid through the dropping funnel while being careful not to raise the temperature of the system. Polyester diol obtained by reacting with ethylene glycol (manufactured by Nippon Polyurethane Co., Ltd., Niraporan 404)
0) 293.4g, specific hydroxyl compound (11)
A uniform mixture of 6.3 g of specific nitrile compound (I), 31.8 g of specific nitrile compound (I), and 400 g of cyclohexanone was poured into the flask, and after completion of the dropwise addition, the mixture was reacted at 60° C. for 4 hours. This was then added with 2.7 g of 2-hydroxyethyl acrylate.
was added and further reacted at 60° C. for 2 hours. After completion of the reaction, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. Table 1 shows the molecular weight and nitrile group content of Polymer Ii 1), which is referred to as Polymer (I).

Synthesis Example 10 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
2.4- After adding 105.5 g of toluene diisocyanate, 1.2 g of dibutyltin dilaurate, and 200 g of tetrahydrofuran and heating to 60°C, add polytetramethylene glycol through the dropping funnel while being careful not to raise the temperature of the system. (Manufactured by Mitsubishi Chemical Industries, PTMG1
00O) 141.2g.

A homogeneous mixture of 99.2 g of specific hydroxyl compound (1), 3.6 g of specific nitrile compound (It), and 400 g of tetrahydrofuran was added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours. Add 30.9g of hydroxyethyl acrylate and add 60g
After reacting at ℃ for 2 hours, a tetrafunctional alcoholic compound (manufactured by Asahi Denka Co., Ltd.) was added.

After the completion of the reaction, 19.6 g of abucafuodrol) was added and the reaction was carried out at 60° C. for 4 hours. After the completion of the reaction, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer thus obtained is referred to as Polymer (J). Table 1 shows the molecular weight and nitrile group content of polymer (J).

Synthesis Example 11 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
2.4- After adding 111.8 g of toluene diisocyanate, 1.2 g of dibutyltin dilaureate and 200 g of cyclohexanone and heating to 60°C, add polyethylene while being careful not to raise the temperature of the system from the dropping funnel. Glycol (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., PEG #400
) 157.6g, polyoxypropylene bisphenol A ether (manufactured by NOF Corporation, D[l-900) 88
．． 6g, specific nitrile compound (111) 1.0°g1
A uniform mixture of 400 g of cyclohexanone and 400 g of cyclohexanone was added dropwise thereto, and after the addition was completed, the mixture was reacted at 60° C. for 4 hours. This was then added with 2-hydroxybupyrmethacrylate 41
．． After the completion of the 0 reaction in which 0 g was added and the reaction was further carried out at 60° C. for 2 hours, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer thus obtained is referred to as Polymer (K). Table 1 shows the molecular weight and nitrile group content of the polymer (K).

Synthesis Example 12 Into a flask equipped with a thermometer, stirrer and reflux condenser, 101.2 g of 2.4-toluene diisocyanate,
1.2 g of dibutyltin dilaurate and a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:
50) After adding 200 g and heating to 60°C, add 145.35 g of polyester diol (1), polyoxyethylene bisphenol A ether (manufactured by NOF Corporation, D
A-350F) 93.0g, specific hydroxyl compound (I) 43.3g, specific nitrile compound (1) 9.
A uniform mixture of 2g and 400g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:50) was added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours.Next, 3.4g of 2-hydroxyethyl acrylate was added to this. was added, and the mixture was further reacted at 60°C for 2 hours, and then 4.68 g of jetanolamine was added, and the mixture was further reacted at 60°C for 2 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer thus obtained is referred to as Polymer (L). Table 1 shows the molecular weight and nitrile group content of the polymer (L).

Synthesis Example 13 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
4.4'-dicyclohexylmethane diisocyanate (103.0 g, dibutyltin dilauret) 1.2
After adding 200 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:50) and heating to 60°C, add 22 g of polyester diol (l) while being careful not to raise the temperature of the system from the dropping funnel.
4.6g, polyoxyethylene bisphenol A ether (manufactured by NOF Corporation, DA-350F) 7.2g, specific hydroxyl compound (1) 40.2g, specific nitrile compound (I) 10.7g, and a mixed solvent of methyl ethyl ketone and cyclohexanone. (Capacity ratio 50:
50) 400g of 2-hydroxyethyl acrylate was added dropwise and reacted for 4 hours at 60°C.
After reacting at 0°C for 2 hours, jetanolamine 11
．． 8 g was added and the reaction was further carried out at 60° C. for 2 hours. After completion of the reaction, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The polymer thus obtained is referred to as Polymer (M). The molecular weight and nitrile group content of the polymer CM) are shown in Table 1.

Synthesis Example 14 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
2.4- 128.7 g of toluene diisocyanate,
1.2 g of dibutyltin dilaurate and a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:
50) After adding 200 g of polytetramethylene glycol (Teratane 65 manufactured by DuPont) and humidifying it to 60°C, take care not to raise the temperature of the system from the dropping funnel.
0) 125.4g, polyoxyethylene bisphenol A ether (manufactured by NOF Corporation, DA-400) 51.
4g, specific hydroxyl compound (1) 38.3g
, specific nitrile compound (I) 50. 8g of 2-hydroxyethyl acrylate and 400g of a mixed solvent of methyl ethyl ketone and cyclohexanone (volume ratio 50:50) were added dropwise, and after the dropwise addition was completed, the mixture was reacted at 60°C for 4 hours. 7 g was added to the colander and reacted at 60°C for 2 hours, then 1.7 g of jetanolamine was added and the reaction was further carried out at 60°C for 2 hours. I confirmed that there are no remaining. The polymer thus obtained is referred to as Polymer (N).

Table 1 shows the molecular weight and nitrile group content of the polymer (N).

Comparative Synthesis Example-1 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
Coronate C-4080 (manufactured by Nippon Polyurethane Co., Ltd.), a prepolymer having an isocyanate group at the end 35
After adding 3.0 g, dibutyltin dilaurate t-1.2 g, and 200 g of hexanone and heating to 60°C, add a compound represented by the following drawing formula while being careful not to raise the temperature of the system from the dropping funnel. A homogeneous mixture of 38.0 g and 400 g of cyclohexanone was added dropwise, and after the addition was completed, the mixture was reacted at 60°C for 4 hours.
g was added thereto, and the mixture was further reacted at 60°C for 2 hours. After the reaction was completed, it was confirmed by infrared absorption spectrum that no isocyanate groups remained in the system. The molecular weight of the polymer (0) obtained in this way is the polymer (0).
Shown in the table.

Table 1 Examples 1 to 14 and Comparative Example 1 Synthesis Examples 1 to 14 and Comparative Synthesis Example! The polymer obtained in (
A) to (0) were used to prepare radiation-curable paints having the proportions shown in the table below.

Each of the above radiation-curable paints was prepared by putting the magnetic powder, solvent, and 3 mm mm DeStainless Steel Pole (150 mu) of the above composition into a 500 m aluminum can, shaking it with a paint conditioner for 2 hours, and then adding a volume of polymer. After further shaking for 4 hours, the stainless steel pole was removed.

Next, the magnetic paint was immediately applied onto a 15 μm thick polyester film to give a dry film thickness of 6 μm, immediately subjected to a magnetic field orientation treatment, and dried overnight at room temperature. After that, using an electro-curtain type electron beam accelerator, the coating film is irradiated with an electron beam at an acceleration voltage of 160 kilovolts and an absorbed dose of 7 megarats to cure the coating film, and the magnetic cured coating film (
I) was obtained.

Further, each of the obtained magnetic paints was immediately applied onto a polyester film having a thickness of 75 μm so that the dry film thickness was 1.5 μm, and was dried overnight at room temperature. Then, using an electron curtain type electron beam accelerator, an acceleration voltage of 16
The coating film is irradiated with an electron beam at an absorbed dose of 0 kilovolts and 7 megarads, and the coating film is cured, creating a magnetic hardening type +1! X (1
1) was obtained.

Separately, in the above IiQ paint composition, a paint with the same composition except for the magnetic powder was used so that the dry film thickness of the paint was 40 to 60 μm on the glass plate, and the paint had a thickness of 1 μm on the glass plate.
40-50μm on 00μm polyester film
After drying overnight at room temperature, 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 paint, magnetic cured coating (I), magnetic cured coating (!■), and non-611 cured coating, the following tests (1) to (9) were conducted. I did it.

The test results are shown in Table 2.

(1) Filtration test: It was observed whether 100% of the 611 paint could be filtered in 1 minute using a filter having an average pore size of 2 μm.

(2) Gloss: Measure the gloss of the magnetic cured coating (I) at a reflection angle of 45° using a digital gloss meter (manufactured by Murakami Color Technology Research Co., Ltd.), and when the gloss is 70-90, ◎, 50- The case of 70 was evaluated as 0130 to 50 as Δ, and the case of 30Ji or less was evaluated as ×.

(3) Surface observation: Observe the surface of the magnetic cured coating (1) using a scanning electronic i-microscope, and confirm that no agglomeration of magnetic powder is observed in all of the multiple test samples. 0 is the state in which some agglutination is observed in some of the test samples; Δ is the state in which some agglutination is observed in all the test samples; The observed condition was evaluated as ×.

(4) Adhesion test: Adhesive tape is pasted on the surface of the magnetic hardening coating (1), and after adhering uniformly to the entire surface, the state is observed when it is instantly peeled off. Di (1) completely from the base! i! 11! The evaluation was rated as ``x'' if it was peeled off, △ if it was slightly peeled off, 0 if it was hardly peeled off, and ◎ if no peeling was observed at all.

(5) Square ratio (Br78m): Toei Kogyo KK VS
Using the M-3 type, the magnetic properties of the magnetic hardening type 11i (I) were measured in an external magnetic field of 5.0000e (Br=
Residual magnetic flux density, Bm = maximum residual magnetic flux density).

(6) Durability test: The magnetic cured coating film (1) was punched out into a mouthpart shape, and the surface was polished to produce a magnetic disk. Load these disks into a floppy disk drive, measure the number of passes until the playback output becomes 50% of the initial output, and if the number of passes is 10 million or more, ◎, 10
The case of 0,000,000 times to 5,000,000 times was evaluated as 0.015 million times or less was evaluated as x. Note that the following four conditions were used as measurement conditions.

■ -10℃ ■ 25℃, 50% relative humidity ■ 50℃, 90% relative humidity ■ -10℃ (30 minutes) to 40℃ (30 minutes) temperature cycle (7) Breaking strength, elongation, initial modulus: Glass A strip-shaped test bead (0.5c
m x 10 cm x 40 to 60 μrn) was cut out and measured at room temperature at a tensile speed of 50 m/win.

(8) Tetrahydrofuran (TIIF) extraction residue The nonmagnetic cured coating film on the glass plate was subjected to TIIF Soxhlet extraction for 24 hours, and the proportion of extraction residue was measured.

(9) Bending test: Cut the non-magnetic cured coating film on the polyester film into strips with a width of 1 cm, fix both ends, bend from the center, and then immediately restore the original state. Do this 20 times per second,
It was observed whether peeling or destruction of the transparent cured coating occurred at the bent portion. Those that withstood flexing for 500 hours were rated as excellent, and those that withstood 400 hours of flexing were rated as good.

The following margins [Effects of the Invention] In addition to having excellent dispersion performance for magnetic powder, the radiation-curable paint of the present invention not only has excellent actual running durability at room temperature, but also has high temperature and high humidity (500 A magnetic recording medium that has excellent actual running durability under a wide range of usage environments, such as under (℃, 90% relative humidity), low temperature (-10℃), and temperature cycle conditions (-10℃ to 40℃). can be given.

Furthermore, the radiation curable coating of the present invention can be applied to magnetic tape,
It is possible to provide a magnetic recording medium that has a magnetic coating film that has excellent adhesion to polyester films that are commonly used as substrate films for magnetic recording media such as floppy disks, and has excellent mechanical strength.

that's all

Claims (1)

[Claims] 1. A radiation-curable paint containing a polyurethane having a nitrile group and a radiation-polymerizable double bond.