JPS60166317A - Urethane acrylate, and composition for coating and adhesive use and magnetic recording medium containing same - Google Patents

Abstract

PURPOSE:To produce a urethane acrylate having excellent elongation at break and tensile strength, and exhibiting excellent dispersing property to magnetic powder as a binder, by reacting a polyisocyanate with a specific polyol and a specific hydroxyalkyl acrylate. CONSTITUTION:The objective urethane acrylate can be produced by reacting (A) a polyisocyanate with (B) a polyester polyol having a molecular weight of 500- 3,000, (C) a polyol having a molecular weight of 60-400 and (D) a hydroxyalkyl acrylate containing >=70mol% monohydroxyalkyl acrylate, at an equivalent ratio of NCO/OH of 0.7-1.20, preferably 0.8-1.05. The product is used as a binder component of a magnetic recording medium. The polyisocyanate is preferably aliphatic or cycloaliphatic isocyanate, and the polyester polyol is preferably the one having a molecular weight of about 800-2,300.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a urethane acrylate that is excellent in both elongation at break and tensile strength, and a composition for sewing and adhesives containing the same.

In recent years, many radiation-curable resin compositions have been developed and are beginning to be used in paints, adhesives, pressure-sensitive adhesives, binders for magnetic tapes, etc., and the scope of their use is expected to further expand in the future. Among them, urethane acrylates that can be cured by radiation have been reported in JP-A-53-17694, JP-A-56-127-623, JP-A-57-8219, and JP-A-58-40546. However, all of these compositions give only hard and brittle cured products, and no tough cured products have been obtained.

At present, a radiation-curable urethane-acrylate having both an elongation at break of 100% or more and a tensile strength of 300 to 97 cm2 or more has not yet been developed. Therefore, the present inventors conducted intensive research and found that a polyester polyol with a molecular weight of 500 to 3,000 and a low molecular weight polyol with a molecular weight of 60 to 400 were used together, and a monohydroxyalkyl acrylate with a molecular weight of at least 700 Mol% containing hydroxyl 1 μl acrylate OH
This is used as a component, and this is combined with polyisocyanate and NCO group 10F! It has been found that urethane acrylate obtained by reacting at a group equivalent ratio in the range of -0.7 to 1.20 gives a tough cured product having FSTMER-like properties. It was also discovered that a magnetic recording medium using this urethane acrylate as a binder component has excellent dispersibility of magnetic powder and heat resistance, and based on these findings, the present invention was completed.

That is, the present invention provides (1) yjf liisocyanate;
Polyester polyol-μ with a molecular weight of 500 to 3.000
9 molecules demon contains less polio-μ and monohydroxyalkyl acrylate of 60-400 Tomo 70-11: /
A urethane acrylate obtained by reacting 1μ hydroxyl acrylate containing L/% in an equivalent ratio of NCO groups and 10H groups in the range of 0.7 to 1.20.

(2) a coating containing the above urethane acrylate;
The present invention is a magnetic recording medium having an adhesive composition, and (3) a magnetic layer containing the above-mentioned urethane acrylate as a binder component.

The polyisocyanate used in the present invention may be aromatic, aliphatic, alicyclic, or araliphatic, but aliphatic and alicyclic are particularly preferred. For example, tetofumethylene diisocyanate, hexamethylene diisocyanate, ω, tII-diisocyanate dimethyl/L/
S/chlorohexane, dicyclohekiyμmethane diisocyanate, isophorone diisocyanate, ω, tJ-diisocyanate dimethylbenzene, methylcyclohekylene diisocyanate, lysine diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, etc., or the I inside of these polyisocyanates, For example, ethylene glycol, propylene glycol
, diprobi V glycol, b+V glycol, trimethylo-p propane, hexane trio-, glycerin, tulpitot p.

Pentaerythritol, mustard oil, ethylenediamine,
Hexamethylene diamine, ethano-ρ amine, diethanol μ amine, triethanolamine, water, ammonia,
Polyisocyanates obtained by reacting low-molecular active water-volume compounds such as urea, or high-molecular active hydrogen compounds such as various polyether μ poly-O-μ, polyester poly-μ, and acryμ poly-O-P, or these Biuretsu F
Compounds, allophanates, and the like are suitable.

Examples of the polyester polyol used in the present invention include adipine and succinic acid.

Polybasic acids such as azelaic acid, cepatic acid, futa/I/6, isophthalic acid, terephthalic acid, etc., for example, 1.
4-butanediol, 1,3-butanedio-μ, ethylene glycol/L/l diethylene glycol, propylene glyco-ρ, 1,2-propylene glycol, siglopylene glycol ~, 1,6-hexane glyco-μ, neobenzi μ glycol Those having molecular chains of about 500 to 3,000, preferably about 800 to 2,300 obtained by precondensation with polyhydric alcohols such as p are useful.

Examples of polyol-μ having a molecular range of 60 to 400 used in the present invention include ethylene glyco-μ, diethylene glycol-, propylene glyco-/I/, dipropylene glyco-/I/, and 1,4-gutanediol. /L'
, 1,3-butanediol, 1,4-cyclohexanethiol μ, 1,4-cyclohexanedimethanol-/L/, glycerin, trimethylo-ρpropane, 3-methyA/1.
Examples include 3,5-pentanetriol.

The hydroxyl 1 μl acrylate used in the present invention is, for example, 2-hydroxyethyl methacrylate V-
), 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypentyl methacrylate, etc.
．． Components other than monohydroxyalkyl acrylate include, for example, various compounds represented by the following formula (in which R1, R2 represent hydrogen or a methyl group, Ri alkylene group, etc.). Ethylene glyco-μ diglycidyl ether ρ obtained by adding methacrylic/I' acid or acrylic/I/acid to an epoxy compound
Metaac UivQl adduct (manufactured by Kyoeisha Yushi Kagaku Kogyo 1, epoxyester/l/40EM), propylene glyco-μ diglycidyl ether acrylic/l/acid adduct (epoxyester/I/70PA), glycerin diglycidyl y
Ether acrylic lv acid adduct (epoxyester/I/8
Examples include dihydroxyalkyl acrylates such as 0MrA).

The urethane acrylate of the present invention is a N
CO group 701 (obtained by reacting the equivalent ratio of the groups at a ratio of about 0.7 to 1.20, preferably about 0, s to 1.05; the amount of monohydroxyalkyl acrylate is 70'e)% If it is less than /%, the molecular weight between crosslinking points will be too small, resulting in only a hard and brittle cured product. Further, even when the amount of monohydroxyalkyl acrylate is less than 70 mol%, it is possible to impart elongation by increasing the molecular weight of urethane acrylate and increasing the molecular weight between crosslinking points. However, more than 100% growth and 300k
A cured product having a tensile strength of g/cts2 or more cannot be obtained. Furthermore, since this urethane acrylate has a large molecular weight, its viscosity increases and its solubility in solvents decreases, making it difficult to handle.

The urethane acrylate of the present invention can also be obtained by a method in which the aforementioned polyisocyanate, polyester μ polyol, low molecular weight polyol, and hydroxyalkyl acrylate are reacted in one step in the ratios described above. It can also be obtained by reacting a polyisocyanate with a mixture with a polyol at the ratio described above (particularly preferred is a ratio that allows for excessive NGO capture), and then adding hydroxyalkyl acrylate to this system and causing the reaction. .

The respective proportions of polyester polyol, low molecular weight polyol and hydroxyalkyl acrylate are as follows.

About 0.02 to 50 equivalents of polyol having a molecular weight of 60 to 400, and about 0.05 to 60 equivalents of hydroxyacrylic acrylate, preferably 1 equivalent of polyester polyol fi/1 equivalent to polyester p polyol fi/1 equivalent. About 0.1 to 10 equivalents of polio-p with a molecular weight of 60 to 400,
Hydroxia! The amount of acrylate is about 0.2 to 12 equivalents.

In the above reaction, if necessary, for example, stannath octoate, dibutyltin dilaurate, tertiary amine or other known urethanization catalysts may be used.

The aforementioned reactions, for example, toene and xylene.

Aromatic solvents such as benzene, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, dichloromethane,
1,1,1-) Halogenated hydrogen ash such as dichloromethane, acetic acid ester μ-based solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and other N,N-dimethylphamides, It is also possible to carry out the reaction in an inert solvent such as H,H-dimethylacetamide, detoxhydrofuran, di-n-butyether, and the like. The solid content of the above solvent is usually about 20 to 80% by weight.

In addition, the produced urethane-acrylate Fujika 1 vol.
In order to prevent the ii polymerization, about 0.001 to 0.05% by weight of an Ojika/I' polymerization inhibitor can be added to the system. Examples of such inhibitors include, for example, hydroquinone, hydroquinone monomethyl ether μ, 2,6-di-t-buty/L/-resol μ and other sterically hindered phenols.

The cured product of urethane-acrylate obtained by such a method has an elongation at break of 100% or more and an elongation of 300 kg/Cl.
It has a tensile strength of T12 or more and has elastomeric properties, but this urethane-acrylate also has one or more unsaturated double bonds that can be cured by radiation, which is called a reactive diluent. By blending a compound with a molecular weight of less than 600 in an amount of about 20M and % or less,
A tough cured product with 0% 00% modulus can also be obtained. Examples of such reactive diluents include tato, t
J-j' 2-Ethylhexyl p-acrylate, 2-ethylhexyl methacrylate, 1,6-hexane-buol diacrylate t, l Tsumethylo-μ propanethrinno+, l (z +-,, y' -f L・/ Green: J
Examples include -JV diglycidi ether, as well as acrylic acid or methacrylic acid adducts of various glycol diglycidi ethers.

The urethane-acrylate of the present invention thus obtained! JL
-ts are other known solvents, pigments, ferrites, fillers which are normally added alone or optionally to coatings, inks or adhesives, etc.

It can be used as a mixture with plasticizers etc. In particular, when the urethane acrylate of the present invention is used as a binder component to produce a magnetic recording medium, the urethane acrylate has good solubility in solvents, so it can be used with a low paint viscosity. , 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.

Manufacture of magnetic recording media can be carried out according to conventional methods.
For example, magnetic powder, urethane acrylate as a binder component, solvent and other additives are placed on a polyester film tonneau substrate. !, ,,
, 13...! Ii (,,, just need to be transferred and hardened,
, Magnetism 8)・, ;,・′・For example, rF'e203.
Fe3O4,G.

Hezu eyes? (4, Kawa, , Co-containing Fe3O4,
CrO2, Fe.

As a means to harden the various AI!magnetic powders, such as Ni, L''):1i gold 11 bow, and other known AI! 1-> plating, ultraviolet curing, heat curing or the like...H, 4 bow) '+,
Any of JL's methods can be adopted! When curing the composition of the present invention by extraneous t'-, a photoinitiator as shown below is added. Part 141
st', +, for example, benzophenone, p-meth N-nopenzophenone, acetophenone, sep-butoxyacetophenone, m-chloroacetophenone, propiophenone, α-hydroxyisobunalophenone, xanthone, benzoin, benzyl, penza-I redehyde , naphthoquinone, anthraquinone, etc., and the amount thereof is about 0.1 to 1%, based on the urethane acrylate contained in the composition.・7-1. A, further methylrmin, dieta/-/Pamiy
, N-methyldiethanolamine, tributylamine, and other photoactivating agents may be added.

When curing the composition of the present invention by heat, Ojika/
I/Polymerization initiators such as hydrogen peroxide, ammonium peroxide, benzoyl peroxide, cumene peroxide, hexane peroxide, di-t-
Butyl veroxide, 1-guti μ hydroperoxide, methyl ethyl ketone peroxide, azobisbutyronitrile, and the like can be used.

When curing by electron beam irradiation, there is no particular need to add a photoinitiator, Tsujika/I/claw initiator, or the like.

Regardless of which of these curing methods is adopted, the self-evident composition of the present invention provides a hard material with extremely strong and tough mechanical properties that could not be obtained hitherto. Metal vaporization) Base coating for paper and polyair Tμ film before f4, protective coating after itAm, branching agent for magnetic tape and floppy disk,
It can be advantageously used as a vehicle for printing inks, as an affective agent, etc.

When the composition of the present invention is used for the above purpose, the film thickness is about 0.
It is applied to a range of about 1 to 100 μm.

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

Example 1 A stirrer, a temperature needle, a reflux condenser, and a 3-liter four-bottle flask were filled with nitrogen gas, and 954 g of Tonorenine 120 (1, polyglylene adibate with a molecular weight of 190B) was added. -Ptanji, t-/l
/22.59. Stanus Octo-124 as a catalyst
I prepared 09. The mixture was heated at 65 tEK, 221 g of isophorone diisocyanate was added, and the mixture was heated at 80 C until the amine equivalent weight became about 2,400. At the same time, 2
-Hydroxyethyl methacrylate 72.51F and hydroquinone monomethy-ether as a stabilizer*1z□#
The mixture was stirred at 70° C. until 98% or more of the isocyanate groups had reacted, yielding the urethane-acrylate (A) of the present invention.

Example 2 A mixture of 1,4-butanedio-/L/11.39 and 11.2 f of trimethylolpropane was used instead of 1,4-butanedio-/L/22.5 g in Example 1. Urethane-acrylate (B) of the present invention was synthesized in the same manner as in Example 1.

Example 3 3-Methyl/l'l, 3,5-pentane trio-
The urethane-acrylate (C) of the present invention was synthesized in the same manner as in Example 1, except that /V33.69 was used.

Example 4 Example 10 33.5 g of dipropylene glycol in place of 1.4-butanedio-/'22.59, ω in place of 2219 (isophorone diisocyanate).

Synthesis of urethane-acrylate (D) of the present invention in the same manner as in Example 1 except that 188 g of tit-cyisocyanate dimethybenzene was used L7'C0 Example 5 Example 10 1. 4-Butanediol 22. 33.5 g of dipropylene glycol (in place of 5su), linisine chlorhexy μ in place of isophorone diisonane) 2211F
The urethane-acrylate of the present invention (
E) was synthesized.

Example 6 Dipropylene glycol/l/33.59. The urethane-acrylate of the present invention (F
) was synthesized.

Example 7 2-Hydroxyethyl methacrylate of Example 1) 72
．． 2-hydroxyethyl acrylate in place of 59)
Urethane-acrylic v-) (G) of the present invention was synthesized in the same manner as in Example 1, except that 59.39 was used.

Example 8 A 3-liter four-bottle flask equipped with a stirrer, a thermometer, and a reflux condenser was filled with nitrogen gas, and 1 liter of toluene was added.
1661F, molecular support 1022 d-lip fV:/1 dibate 767g, 3-)flvl, 3.5-pentane trio-IL'679. Nutanus octoea as a catalyst) 233q was charged. heating the mixture to 65°C;
332f of isophorone diisocyanate was added, and the mixture was stirred at 80° C. until the amine equivalent became about 2,400. Next 2
-Hydroxyethyl methacrylate 71. (l and hydroxyl monomethyl ether as stabilizer 1v1201
f and stirred at 70°C until 98% or more of the isocyanate groups reacted.
It was a river.

Example 9 In place of 1,4-butanedio-)V22.5t in Example 1, 1,4-butanedio-/''17.59 and ethyl glycol μ diglycidi p ether methacrylate/I/!!i
l + adduct (Kyoeisha Oil and Fat Chemical Industry (a) > 1 Eboki V
The urethane acrylate (IJ) of the present invention was synthesized in the same manner as in Example 1, except that 19.3 g of the mixture of ester lv+oFiM) was used.

Example 10 A 3-liter 4-room vacuum cleaner equipped with a stirrer, a thermometer, and a rapid flow cooler was filled with hydrogen gas, and 1 liter of toluene was added.
2351F, hydroxy μ value 58.8J = Shinobutylene adipate 9541F, dipropylene glyco-/L'33.59.2-hydroxyethyl p methacrylate 65g, diphenylmethane diisocya *-) 25
(1, Hydroquinone monomethypate A as a stabilizer
'120q is processed until the amine resistance becomes constant (approximately 1
2,000) 7 (l) to obtain the urethane-acrylate (J) of the present invention.

Examples 11 to 29 Urethane-acrylate obtained in Examples 1 to 6)
A composition containing (A) to (E) and a reactive diluent are coated on a polyester film with a 6 mil doctor blade and cured by irradiation with ultraviolet rays or electron beams. 100% modifus of things,
Tensile strength and elongation at break were measured.

In the case of UV curing (try), Darocur 1173 (Merck, Darocur 11) was used as a photoinitiator.
73) and jetanolamine as a photoactivator, and was cured by irradiation with 2 kilowatts of ultraviolet radiation at a height of 12 cm and a width of 10 cm for 3 to 6 seconds.

Further, in the case of electron beam curing (EB), curing was performed with an irradiation dose of 214 rad.

Table 1 shows the 100% modulus strength and elongation at break of these composition formulations and cured products.

Example 30 Urethane-acrylate (J) obtained in Example 10
) 1001F, 1.6-hexanethiolmiacrylate) 2.5f, bency peroxide/l'Log was applied onto a polyester film using a 6 mil doctor blade, and heated at 140°C for 1 hour. After baking in a txt warmer, the 100% 00% modulus shear strength and elongation at break of the cured product were measured.

The final result is shown in -a,1.

()me, lower ijs mortar) 1! Example 31 1- Fe2O2100 Ichiibe Urethane Acrylate (G) 20# 1.6HX-A O,5〃 Vinyl chloride μ-vinyl acetate p-vinyl alcohol copolymer (
Manufactured by WAGHHIJCC) 10 parts 1 Y part lecithin 1
〃Methi-ethyμketone 150'/toluene 150〃 A magnetic paint was prepared with the above composition and applied onto a 16μ thick polyethylene terephthalate base film, dried and calendered. In contrast, the accelerating voltage 17
After irradiating it with an electron beam of 4 Mrad at 5 KV, it was cut into a predetermined width to make a magnetic tape. The squareness ratio of the obtained magnetic tape was Br/Bs-0.81, and the maximum magnetic flux density was Be.
- 1850G, and after applying 1kg of tension to the tape and wrapping it around a glass tube, leaving it for 24 hours at 4SE, SO%RH, and then 24 hours at room temperature, no adhesion was observed when it was unwound. . As is clear from this, the magnetic paint prepared using the urethane acrylate of the present invention as a binder component has good dispersibility of magnetic powder, and as a result, the squareness ratio, Rk large magnetic flux density, and 1lIt thermal property are high. A good magnetic recording medium could be obtained.

Claims (3)

[Claims] (1) Polyisocyanate, molecular weight 500-3.00
0 polyester polyol, polyol-μ having a molecular weight of 60 to 400, and hydroxyacrylic μ acrylate containing at least 707 p% of monohydroxyacrylic acrylate, with an equivalent ratio of NCO groups to 10H groups in the range of 0.7 to L20. Urethane acrylate obtained by reacting with (2) Polyisocyanate, molecular weight 500-3.00
0 polyester μ polyol μ1 having a molecular weight of 60 to 400 and hydroxyl μ μ acrylate containing at least 70 mol % of monohydroxyalkyl acrylate in an equivalent ratio of NCO groups to 10H groups −0.7 to 1.20
A coating or adhesive composition containing urethane acrylate obtained by reacting in the range of . (3) Polyisocyanate, molecular weight 500-3.0
00 Polyeste μ Polyol μ 1 molecule is 60-400
polyol and hydroxyalkyl acrylate containing at least 707 μ% of monohydroxyacrylate in an equivalent ratio of NCO groups of 10 μm to −0.7 to 1.2
A magnetic recording medium having a magnetic layer containing as a binder component urethane acrylate obtained by reacting in a range of 0.