JPS63162664A - Urethane group-containing vinyl compound, coating and adhesive composition containing said compound and magnetic recording medium - Google Patents

Abstract

NEW MATERIAL:An urethane group-containing vinyl compound obtained by reacting a hydroxyl-containing compound with a compound expressed by the formula (R is H or methyl). USE:Useful as coating and adhesive compositions and magnetic recording medium. The above-mentioned compound has excellent abrasion resistance and electric characteristics and easy in curing treatment by electron beam, etc., and is excellent in productivity. When the compound is used as coating and adhesive compositions for magnetic recording medium, the composition has large squareness ratio, improved surface roughness and electromagnetic conversion characteristic as well as excellent abrasion resistance. PREPARATION:A hydroxyl group-containing compound such as vinylchloride based copolymer, saturated polyester resin, etc., is reacted with a compound expressed by the formula (R is H or methyl) in a solvent such as methylisobutylketone, etc., to provide the urethane group-containing vinyl compound. The compound expressed by the formula includes e.g. m-isopropenyl-alpha,alpha- dimethylisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a urethane-based vinyl compound that can be cured with an electron beam or the like, and coating and adhesive compositions containing the same.

ri', b xlz, tI+1kl A three-dimensional network is formed through a chemical reaction with a reactive functional group typified by an amino group.

However, the use of such a thermosetting binder has a limit in responding to the remarkable increase in recording density of magnetic recording media and the rationalization and automation of the production process.

Specific problems are listed below: (1) The pot life of the composition is short. In addition, the rate of faeces varies depending on the material in the magnetic paint and the environment, and it can be adjusted by 1 <, the retention of the paint? - Problems such as stability and fluctuations in the surface formation treatment effect of the coating occur. Furthermore, it takes a long time for complete curing, and the surface roughness of the back surface of the substrate that the coating surface comes into contact with during curing aging is likely to change, and the magnetic layer, which is an important property for j-density recording media, is susceptible to changes in surface roughness. This can easily lead to a decrease in surface smoothness.

(2) Since thermal energy is used to promote the curing reaction, the energy efficiency is poor, and the solvent used is h because the polymer is mainly n1.
Since there are many 1s, energy costs and solvent costs are high.

Problems to be Solved by the Invention The present inventors conducted intensive research and found that a compound represented by [wherein R represents hydrogen or a methyl group] was used as an isocyanate compound, and this and a hydroxyl group-containing compound were used. The urethane group-containing vinyl compound obtained by the reaction does not have the above-mentioned drawbacks, has excellent mechanical properties, especially abrasion resistance and electrical properties, and has an easy curing process, and can be used as a coating with excellent productivity. It was discovered that an adhesive composition can be provided, and based on this knowledge, the present invention was completed.

Means for Solving the Problems The present invention provides (1) a urethane group-containing vinyl compound obtained by reacting a hydroxyl group-containing compound with a compound represented by the general formula [wherein R does not represent hydrogen or a methyl group];

2. A coating or adhesive composition containing a urethane group-containing vinyl compound obtained by reacting a hydroxyl group-containing compound with a compound represented by the general formula [wherein R represents hydrogen or a methyl group], and 3. A magnetic recording medium in which a magnetic layer containing a urethane group-containing vinyl compound obtained by reacting a hydroxyl group-containing compound with a compound represented by the general formula [in the formula, no hydrogen or methyl group is shown] as a binder component is subjected to rT. Regarding.

Examples of the hydroxyl group-containing compound used in the present invention include those having a molecular radius of less than 1000 (e.g., ethylene glycol, ethylene glycol, propylene glycol, 1
．． 4-butylene glycol, neopentyl glycol,
1.6-hexane glycol.

Diols such as cyclohegisan dimethanol.

Triols such as glycerin, trimethylolpropane, 1,2,6-hexane glycol, pentaerythritol, α-methyl glycoside, xylitol, sorbitol, sucrose, etc.)6 can be used, but in particular the molecular dish Beyond tooo, such as vinyl chloride yarn copolymer, saturated polyester resin, polyvinyl alcohol resin, epoxy resin, phenoxy resin, fiber T:
Derivatives and the like are preferred.

The above copolymers or resins are specifically shown below.

Examples of vinyl chloride copolymers include vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl alcohol copolymer, vinyl chloride-vinyl alcohol-vinyl propionate Am combination, and vinyl chloride-vinyl acetate-malein. acid copolymer,
Vinyl chloride-vinyl acetate-vinyl alcohol-maleic acid copolymer, vinyl chloride-vinyl acetate-0 terminals
1-1 side chain alkyl group copolymer, such as UCC V
1101-1, VYNC, VYEGXSVER[t,
VYES, VMCA, VAGHIM) [527, MXr
One example is Z528.

Among these, those modified with carboxylic acid, particularly copolymers having maleic acid as a constituent unit, are preferred because they have good affinity with magnetic powder and have excellent dispersibility.

Examples of the saturated polyester resin Rrt include saturated polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, and sebacic acid; 1.2 propylene glycol, 1,3 butanediol, dipropylene glycol, 1.4 butanediol, 1゜6 hexanediol, Benchlistrit, sorbitol, glycerin, neopentyl glycol, 1.4 cyclohexane dimetatool, etc. Saturated polyester resin obtained by ester bonding with polyhydric alcohol or these polyester resins
Examples include resins modified with etc.

Examples of the polyvinyl alcohol resin include polyvinyl alcohol, butyral resin, acetal resin, formal resin, and copolymers of these components. These are preferable because they have good affinity with magnetic powder.

Examples of epoxy resins and phenoxy resins include bisphenol 8 and epichlorohydrin.

Epoxy resin by reaction of methyl epichlorohydrin,
For example, Shell Chemical (Epicoat 152.154.8)
28.1001, 1004.1007), manufactured by Dow Chemical (DEN431.DEn732, DErt511, D
Ert331), Dainippon Ink (Epicron 400.
800), and U which is a high polymerization degree resin of the above epoxy
CC phenoxy resin (PKHA%PK HC,P
K I-11-1), a copolymer of brominated bisphenol 8 and epichlorohydrin, manufactured by Dainippon Ink Chemical Industry Co., Ltd. (Epicron 145.152.153.1120), etc., and those containing carboxylic acid groups. Also included.

Fiber T: Various derivatives are used, but
Examples include nitrified cotton, cellulose acetobutyrate, ethyl cellulose, butyl cellulose, and acedel cellulose. Nitrified cotton containing carboxyl J& (Seltsuba EX-1 manufactured by Asahi Kasei Industries, Ltd.) has a hydrophilic group such as a carboxylic acid group, so it is particularly suitable because it is compatible with magnetic powder.

Other resins include polyfunctional polyester resins, polyether ester resins, polyvinylpyrrolidone resins and derivatives (r'VP olefin copolymers), polyamide resins, polyimide resins, phenol resins, spiroacecool resins, and hydroxyl groups. Acrylic resins containing at least one type of acrylic ester and methacrylic ester as a polymerization component can be used.

The hydroxyl group-containing compound described above is reacted with a compound represented by the general formula [wherein R does not represent hydrogen or a methyl group]. Examples of the compound represented by the above formula include p-isopropenyl-α.

α-dimethylbenzyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, p-
Edilenyl α, α-dimethylbenzyl isocyanate-1
-, ta-ethyleneyl α, α-dimethylbenzyl isocyanate, 11-ethylenyl α.

Examples include α-dimethylbenzyl isocyanate.

Among the above compounds, isopropenyl-α,α-dimethylbenzyl isocyanate (hereinafter abbreviated as m-TMl) is preferred.

The "bipedal reaction" is carried out in such a manner that the compound represented by the "bipedal general formula" reacts with a portion of the ON group of the hydroxyl group-containing compound. It is preferable that about 10 to 80 mol% of the 011 groups react. This reaction is carried out in the presence or absence of an organic solvent.

Examples of organic solvents include aromatic solvents such as toluene, xylene, and benzene; examples include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

Ketone solvents such as cyclohexanone, dichloromethane, 1.1.1-1-lichloroethane, etc.
7 Genated hydrocarbons, such as ethyl acetate, butyl acetate, acetate-based solvents such as isopropyl acetate, butyl acetate, and other N,N-dimethylformamides, N,
N-dimethylacetamide, tetrahydrofuran, di-
Examples include n-butyl ether. The above-mentioned solvent usually has a solid content of about 20 to 80% by weight.

In the above-mentioned reactions, if necessary, for example, sulfur tin dilaurate, sulfur tin dilaurate, etc.

Tertiary amines and other known urethanization catalysts can be used.

As described above, a hydroxyl base n compound was prepared with the general formula [wherein R
does not represent hydrogen or methyl group] is a compound that has a urethane group and a vinyl group derived from the above compound in its molecule.

The urethane group-containing vinyl compound of the present invention may be used alone or, if necessary, in other known solvents which are usually added to coatings, inks, adhesives, and the like.

It can be used as a mixture with pigments, ferrites, fillers, plasticizers, etc. In particular, the urethane group-containing vinyl compound of the present invention is used as a binder component.

However, when producing a magnetic recording medium, the coating material can be used with a low viscosity, and as a result, the dispersibility of the magnetic powder is good. In addition, since it has good fluidity, a magnetic layer with good film properties can be obtained, and as a result, a magnetic recording medium with excellent heat resistance can be manufactured.

When used as a coating or adhesive composition for magnetic recording media, a low-molecular m compound having a vinyl group in the molecule may be added as a reactive diluent to the urethane group-containing vinyl compound. Examples of such reactive diluents include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, 1,6-hexane glycol diacrylate, and 1,6-hexane glycol diacrylate. Recall Dimethacrylate 1・
, N-vinylbi[l-lydone, pentaerythritol tetraacrylate (methacrylate), pentaerythritol triacrylate (methacrylate-1), trimedylolpropane triacrylate, trimethylolpropane trimethacrylate, polyfunctional oligoester acrylate (Aronix M-710) ,M-5400,55
00, 5700 (Tohoku Gosei), urethane elastomers with acrylic modified products of Tuborane 4040), trimethylolpropane diacrylate (methacrylate), phenol ethylene, etc., in which functional groups such as GOOII are introduced into urethane elastomers. Examples include acrylate (methacrylate) of oxide adducts.

These reactive diluents may be used alone or in combination of two or more.

The proportion of reactive diluent is usually on the order of about 5-80% by weight.

Manufacture of magnetic recording media can be carried out according to conventional methods.
For example, on a substrate such as a polyester film, magnetic powder, a urethane group-containing vinyl compound as a binder component,
A magnetic paint containing a solvent and other additives may be applied by any means such as spraying or roll coating, and dried and cured. As the magnetic powder, for example, 7-Fe
to 3. F 13304 + CO-containing 7- F et
o3. Co-containing FasO+, Cr0t, Fe.

Examples include various known magnetic powders such as metals such as Ni and Go.

Means for curing the coating and adhesive composition of the present invention include:
For example, electron beam curing, ultraviolet curing, heat curing, or any other known means can be employed.

When curing the composition of the present invention with ultraviolet light, a photoinitiator as shown below is added. Specific examples include benzophenone, p-methoxybenzophenone, acetophenone, 5ec-butoxyacetophenone, and m-chloroacetophenone.

Propiophenone, α-hydroxyisobutyrophenone, xanthone, benzoin, benzyl, benzaldehyde, naphthoquinone, anthraquinone, etc., and the loss is about 0.1% relative to the urethane group-containing vinyl compound contained in the composition. ~15% by weight is used. At that time, further methylamine, jetanolamine, and N-methyljetanolamine.

Photoactivators such as tributylamine may also be added.

When curing the composition of the invention by heat, known radical polymerization initiators such as hydrogen peroxide and anthene persulfate are used. Benzoyl peroxide.

cumene oxide, cyclohexane peroxide, di[-butyl peroxide, [-butyl hydroperoxide], methyl ethyl ketone peroxide,
Azobisisobutyronitrile and the like can be used.

When curing by electron beam irradiation, addition of a photoinitiator, a radical polymerization initiator, etc. is not particularly required.

Regardless of which of these curing methods is employed, the composition of the present invention provides a cured product with extremely excellent mechanical properties that have not been previously available. It can be advantageously used in base coatings for polyester films, protective coatings after vapor deposition, coatings for magnetic tapes and floppy disks, vehicles for printing inks, adhesives, and the like.

When the composition of the present invention is used for the above purpose, the film thickness is about 0.
Apply to a range of about 1-100μ.

R friend! 1. The urethane group-containing vinyl compound of the present invention can be cured by electron beams or the like, so it has excellent productivity. In addition, when used as a coating for magnetic recording media or as an adhesive composition, it has advantages such as a high squareness ratio, good surface roughness, and therefore good electromagnetic conversion characteristics and excellent wear resistance. There is.

Go to 6E, 1, a? The 20 cardinal system is used, for example, in floppy disks, video tapes, digital audio chips, video floppies, and the like.

EXAMPLES The present invention will be explained in detail with reference to Examples below.

Example! 312 with stirrer, thermometer, reflux condenser and 9 dropping funnels
800 g of toluene and 800 g of methyl isobutyl ketone were placed in a No. 40 flask, and the temperature was raised to 50°C.

This mixed solution was mixed with vinyl chloride-vinyl acetate-vinyl alcohol resin (Union Carbide Co., Ltd. V G11.
Vinyl chloride 89.5 mol%, vinyl acetate 2.2 mol%,
Vinyl alcohol 8.3 mol%, average degree of polymerization 430)2
50g was added and dissolved. Next, 0.01 g of hydroquinone and 0.37 g of dibutyltin dilaurate were added to this solution.
After adding 40.2 g of ra-'rM1, 40.2 g of ra-'rM1 was added dropwise over 1.5 hours. After the dropwise addition was completed, the temperature was raised to 90°C, and stirring was continued for 8 hours. The reaction progresses every hour! !
It was checked by the decrease in the absorption of ν(NGO) at 2270 cm-'. When the absorption of ν(NGO) disappeared, it was cooled to room temperature.

Example 2 300 g of toluene, 100 g of methyl ethyl ketone, 1 liter in a 2Q40 flask equipped with a stirrer, thermometer, and reflux condenser.
16 g of 1-TM 1 was mixed and dissolved. Subsequently, 0.2 g of dibutyltin dilaurate and 0.02 g of [)-methoxyphenol were added, and the temperature was raised to 70°C.

After that, a solution of 25% solid content of nitrified cotton in methyl ethyl ketone (
400 g of Nitrified cotton (1tS L/2) manufactured by Daicel Corporation was added and heated to 75-80° C. with stirring to continue the reaction. The progress and termination of the reaction were carried out in the same manner as in Example 1.

Example 3 200 g of toluene and 200 g of methyl ethyl ketone were placed in a 212/L flask equipped with a stirrer, fA meter, and reflux condenser.
and va-TMI IOg. Further, 0.015 g of p-methoxyphenol and 0.15 g of dibutyltin dilaurate were added to form carboxyl group-containing nitrocellulose (manufactured by Asahi Kasei Industries, Ltd., trade name: Seltsuba EX-1).
300 g of a 25% solids solution was added. Temperature 75-8
Maintained at 0°C, ν(N
The reaction was continued until the absorption attributed to GO) disappeared.

Example 4 Stirrer, thermometer. 272 with reflux condenser and dropping funnel
Charge 200 g of toluene and 200 g of methyl ethyl ketone into a 4 ml flask and raise the temperature to 50°C.

Polyvinyl alcohol resin (manufactured by Mki Kagaku Kogyo Co., Ltd.)
Denka Butyral #2000L, vinyl alcohol composition 18-24% by weight, vinyl acetate composition 3x h1% or less, vinyl butyral composition 73% by weight or less, average degree of polymerization 300
) was added and dissolved while stirring. Subsequently, add 1.0.2 g of Pudil tin dilaure and 0.02 g of paramethoxyphenol, and add 45 g of a-'I"MI to 3
It was added dropwise over 0 minutes. After completion of the dropwise addition, the reaction was continued at 75-80°C [ν of 2270 cra-' in R (NGO
) continued until it disappeared.

Examples 5-8 Ferromagnetic alloy powder 300 weight major axis 0.
5μ, axial ratio 7 11c 1400 eluminate.

Specific surface area 50 m''/g Urethane group-containing vinyl compounds obtained in Examples I to 4 100 parts by weight Trimethylolpropane triacrylate 20 parts by weight Lecithin 3 parts by weight Silicone oil KF-96 (Shin-Etsu Chemical) 6 parts by weight Methyl isobutyl ketone 250 parts by weight toluene
250 parts by weight of the above composition was mixed and dispersed in a ball mill for 48 hours to obtain a magnetic coating composition. This magnetic coating composition was applied to a 15μ thick polyester film (Toshiku Co., Ltd.).
It was coated onto a tIJ Lumirror using a doctor blade to a dry film thickness of 4 μm, subjected to magnetic field orientation treatment, and dried. Then smoothed with a super calender.
No Seven Cos ψ Su Fls m gu r only 1 〒 訳 - h L r ふ 山 - 4 - Rumored Using an electron beam accelerator, magnetism was generated by irradiating an electron beam in a nitrogen gas atmosphere at 175 KV and 5 Mrad. A polymerization curing reaction of the coating film was carried out. The results are shown in Table 1.

Comparative Example 1 300 parts by weight of ferromagnetic alloy powder (same as Examples 1 to 4) 50 parts by weight of vinyl chloride, vinyl propionate-vinyl alcohol copolymer (S-LEC C; manufactured by Sekisui Chemical Co., Ltd.) Tuboran 2304 in polyurethane elastomer: Made of polyurethane) 50 parts by weight lecithin 3 layers! i 1 part Silicone oil Kl''-96 (manufactured by Shin-Etsu Chemical) 6 parts by weight Methyl isobutyl ketone A Q Om lit
500 parts toluene! n part The above composition was cross-dispersed in a ball mill for 48 hours, filtered through a filter, and then 15 times a trifunctional polyisocyanate (Takenate E-30V, manufactured by Takeda Pharmaceutical Co., Ltd.) prepared by adding 3 moles of tolylene diisocyanate to trimedylolpropane was added. 1
part was added and mixed. This magnetic paint was applied onto a polyester film, subsequently subjected to magnetic field orientation treatment, and dried.

Thereafter, it was subjected to supercalender treatment and cured at 60°C for 7 days.

Comparative Example 2 S-LEC C of Comparative Example 1 was nitrified with Daicel RSI/
It was the same as Comparative Example 1 except that it was changed to 2.

Comparative Example 3 This was the same as Comparative Example 1 except that Niraporan 2304 in Comparative Example 1 was replaced with polyurethane elastomer Nisten 5702 manufactured by Gudrich, USA.

The results are shown in Table 1.

Table 1 ■) Surface gloss Surface gloss meter (manufactured by Suga Test Instruments Co., Ltd.)
2) Measurement was performed using a rectangular specific vibration sample type magnetometer (manufactured by Toei Kogyo).

3) Disappearance Length 25cm using Gakushin type friction and wear tester.

A load ff of 150 g was added to a tape cut into 3 cm pieces using No. 1000 sandpaper, shedding was performed 10 times, and wear m was measured from the change in weight before and after shedding.

As is clear from the table, the magnetic tape obtained using the binder of the present invention has a larger squareness ratio than that obtained using the conventional thermosetting binder, has improved electromagnetic properties, and has a lower powder drop m. As a result, wear resistance has improved.

Claims (1)

[Claims] 1. Hydroxyl group-containing compounds include urethane group-containing compounds obtained by reacting compounds represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, R represents hydrogen or a methyl group] vinyl compound. 2. Hydroxyl group-containing compounds include general formulas ▲ mathematical formulas, chemical formulas, tables, etc. Coating and adhesive compositions. 3. Hydroxyl group-containing compounds include general formulas ▲ Numerical formulas, chemical formulas, tables, etc. A magnetic recording medium having a magnetic layer containing .