JPS6042473A - Binder resin composition for magnetic tape - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has a high curing rate and gives a coating film having a smooth surface, consisting of a specified unsaturated polyester resin and an ethylenically unsaturated monomer. CONSTITUTION:An epoxy group-contg. compd. such as epichlorohydrin is reacted with a bisulfite such as sodium bisulfite at 20-200 deg.C to obtain a polyfunctional monomer contg. a sulfonate salt group. An acid component contg. an unsaturated dicarboxylic acid, a polyhydric alcohol, the above polyfunctional monomer and optionally a polyhydric alcohol allyl ether are subjected to an esterification reaction and then to a condensation reaction. The resulting unsaturated polyester resin, an acrylic monomer and optionally an isocyanate compd. are reacted together to obtain an unsaturated polyester resin (A) wherein the acrylic monomer is bonded at its terminal. 90-20wt% component A is mixed with 10-80wt% ethylenically unsaturated monomer (B) such as styrene.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a binder for magnetic tape using a specific polyester resin as a binder.

Various resins have been reported as binders for magnetic tapes such as cassette tapes and video tapes.

With the spread of home video recorders and audio tape recorders, the demand for video tapes and audio tapes has increased significantly, and their performance has become even higher in terms of image quality, sound quality, etc. Although quality is a matter of concern, the performance of the binder, which plays the role of uniformly and densely filling the magnetic layer coated on the base film of the tape, plays a large role in the performance of the magnetic tape, so aIJl 1117 also has various characteristics. This is something that has been devised.

a1j1 Polyester resins containing metal salts of sulfonic acid have superior dispersibility to magnetic powder and adhesion to base films compared to conventional binders, so the demand for them is increasing significantly. . Especially recently, in order to improve the curing speed after coating on the base film and to perform more efficient work, acrylic-based twoffI#I! Attempts have been made to introduce i-coupling and irradiate it with electron beams or the like.

However, the difference in curing time in units of several seconds is extremely large for magnetic tape! ! Attempts made in the II manufacturing process have not always been sufficient, and a satisfactory curing speed has not yet been achieved. Furthermore, there is room for improvement in the smoothness of the tape surface after coating and drying, and more precise performance is required, and an immediate solution is desired.

However, the inventors of the present invention, as a result of intensive research into the above-mentioned problem, have developed a sulfonate obtained by reacting an epoxy group-containing compound with an acidic sulfite as a component of polyester OJ fat. An unsaturated polyester 0j resin that uses a tin-containing polyfunctional lit polymer and an unsaturated nocarboxylic acid and has an acrylic monomer bonded to the resin terminal, and (b) an ethylene bamboo unsaturated monomer as the main ingredient. The baingoo resin composition for magnetic tape has sufficient MIi performance such as dispersibility and adhesion, and is resistant to V due to radiation, etc.
We found that it hardens much faster than L wood, and has significant effects such as scale reduction. Furthermore, as a component of the unsaturated polyester 43411n, a magnetic tape binder (in the case of a lubricant composition, there is no risk of effect failure even in the air) is used, which is based on an unsaturated polyester resin combined with polyhydric alcohol allyl ether. The present inventors have discovered that they have extremely useful industrial properties, such as being able to easily perform coating operations, and have completed the present invention.

In the present invention, first, a polyfunctional monomer obtained by reacting an epoxy group-containing compound with an acidic sulfite must be used as a component of the unsaturated polyester resin.

The present invention is characterized in that a sulfonic acid group-containing polyhydric alcohol produced by a specific method for peeling is used as a component of the unsaturated polyester resin, and conventionally well-known examples such as sodium sulfoiso7ylate If a magnetic tape is used, the smoothness of the tape surface after manufacturing the magnetic tape is not sufficient, and problems remain. Polyfunctionality in the present invention means that the molecule contains at least +1.2 or more carboxyl groups or hydroxyl groups, and the presence of the functional groups makes it possible for polyester 47111i? can be manufactured. The reaction of acidic sulfite with epoxy groups is conventionally known and is as follows.

MIISO, + -C1l-CIl! →-CB-CI+2-011 Also 1i C11-Cl2
-SO, MSO, M O11 (However, in the formula, the old one indicates an alkali metal) As is clear from the above formula (, one sulfonate and one hydroxyl group are generated for each epoxy group, so The greatest feature of the present invention is to utilize the hydroxyl groups in the condensation reaction of polyester resin.Therefore, if a compound having two or more epoxy groups is reacted with an acidic sulfite, the number of hydroxyl groups is the same as the number of epoxy groups. Although a polyfunctional monomer having a hydroxyl group can be obtained, it is not necessarily limited to compounds having two or more epoxy groups, and even compounds having only one epoxy group can be obtained. , in addition to epoxy, one water rna in the molecule
Or, if it is a compound that has one or more carboxyl groups, or a compound that has a water rg1 group or a group that can become a carboxyl group by hydrolysis etc., it is possible to produce a polyfunctional 111'J monomer, so polyester resins can be used. It can be used as a raw material for

The content of the polyfunctional monomer is 0.05 to 10 mol%, more preferably 0.05 to 10 mol% based on the total acidic content in the unsaturated polyester υ [T, with a molecular weight of 1 mol per SO,N group. It is introduced in a range of 0.05 to 5 mol%. If O,OS is less than mol%, the effect of improving the dispersibility of magnetic powder etc. cannot be obtained,
If the amount is more than 10 mol%, gelation tends to occur during the production of unsaturated polyester II fat, making stable production impossible, which is undesirable.

The reaction between a compound having an epoxy group and an acidic sulfite is usually carried out by charging 1 to 4 moles of the latter to 1 mole of the epoxy group in the former, and at a temperature of 20 to 200°C in the presence or absence of a solvent.
All you have to do is react. If necessary, it is also possible to use catalysts such as amines and imidazole. As a solvent, general-purpose solvents such as IL7J Recol of water, ether, ester, benzene, toluene, xylene, acetone, dioxane, etc., and mixtures of these! Seri is used as appropriate.

Compounds containing such epoxy groups include epichlorohydrin, glycidol, ethylene glycol mono(or) glycidyl ether, noethylene glycol mono(or) glycityl ether, triethylene glycol mono(or) glycityl ether, Polyethylene glycol mo(or di)glycidyl ether, propylene glycol mono(or)) glycidyl ether, polyethylene glycol mo/(or)) glycidyl ether, butylene glycol mo/(or:)) glycidyl ether, polyethylene glycol mo/(or) di)glycidyl ether, neopentyl glycol mono(also di)glycidyl ether.

1,6-hexanediol mono(or di)glycyl ether, bis7er/-l^ type mono(or di)glycyl ether, bisphenol A type ethylene oxide adduct mono(or)) glycycyl ether adduct 7 (or di)glycidyl ether, hydrogenated bis7 ester/Δ type mono(or)) glycytyl ether, hydrogenated bis7 ester/ethyl ethylene oxide adduct mono(or)) glycytyl ether, water Propylene oxide adduct to bis(7) ester (or di)glycidyl ether, oxalic acid mono(or)) glycidyl ester, malonic acid mono(or)) glycinole ester, succinic acid mono(or) )) Glycidyl ester, glutaric acid mono(or)) glycidyl ester, 7nopic acid mono(or) glycidyl ether, pimelic acid mono(or)) glycidyl ester, speric acid mono(or))
or)) glycitul ester, sebacic acid mono(or)
) glycidyl ester, mono(or)) glycidyl ester, mono(or)) glycidyl ester, mono(or)) terephthalate, glycidyl ester, mono(or)) glycidyl ester, O,mrll-hydroxybenzoic acid Tulu ether, Qgmvp-Hydroxyamne Q8 acid glycysol ester, 0tIlrn-Hydroxyamne Q8 acid noglycyl ester ether, 1,3-nobrinnor-5
, 5-nomethylhyguntoin, etc., alicyclic epoxy compounds such as cyclohexanediol mono(or) glycidyl ether, cyclohexanenocarboxylic acid mono(or) glycidyl ester, glycerin, pentaerythritol, trino Typical examples include polyhydric alcohols such as tyrolpropane in which at least one of the hydroxyl groups is a glycityl ether group, and polybasic acids such as trinolinodoic acid and biromellitic acid in which at least one of the carboxyl groups is a glycityl ester. It is mentioned in

Examples of the acidic sulfite to be reacted with the compound having an epoxy group include acidic sodium sulfite, acidic potassium sulfite, etc. Sodium sulfite is more practical.

The next essential component of the unsaturated polyester resin used in the present invention is the use of an unsaturated nocarboxylic acid. Unsaturated nocarboxylic acid is 20 to 100 mol% of the total acid component,
More preferably, it is used in an amount of 30 to 100 mol%. 20 mol%
If it is less than that, the curing speed will be slow. As the unsaturated nocarboxylic acid, maleic acid (anhydride) is most preferred, but unsaturated nocarboxylic acids such as fumaric acid, itaconic acid, and thorafunic acid and lower alkyl esters thereof can also be used.

Another essential component of the unsaturated polyester resin used in the present invention is that an acrylic monomer is bonded to the terminal end of the resin. The acrylic monomer is a compound having a carboxyl group or a hydroxyl group and an ethylenically unsaturated bond, such as acrylic acid, methacrylic acid, crotonic acid, incrotonic acid, or their methyl esters, Alkyl ester such as ethyl ester, 2-hydroxyethyl (meth)acrylate, 2
-Hydroxypropyl (meth)acrylate and polyfunctional (
IB alcohol and epichlorohydrin adduct (meth)
Derivatives such as anti-1δ acrylic acid (for example, epoxy ester manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) are used. An ethylenically unsaturated bond and an unsaturated bond based on an unsaturated carboxylic acid are simultaneously present at the molecular end of the unsaturated polynisple Ijl lff, leading to the formation of binders for magnetic tapes with a fast curing speed as in the present invention. It is possible to do so.

Therefore, the unsaturated polyester resin components other than the sulfonic acid group-containing polyfunctional phosphor, the unsaturated nocarboxylic acid, and the acrylic 1ij m II are acid components and polyhydric alcohol components used in the production of ordinary polyester resins. can be used arbitrarily.

Examples of acidic components include oxalic acid, malonic acid, succinic acid,
Geltar acid, 7 nobic acid, trimethyl r nobic acid, pimelic acid, 2,2-methylglucuric acid, azelaic acid, sebacic acid, 1,3-cyclohexanenocarboxylic acid
'1.1.4-/Clohexanenocarboxylic acid, 7-talic acid, terephthalic acid, isophthalic acid, 2.5-norpornannocarboxylic acid, 1.4-7-talic acid, nophenic acid,
4,4'-oxybenzoic acid, diglycolic acid, thiopropion-4,4'-sulfonylbenzoic acid, 2,5
Saturated carboxylic acids such as -s7tale dicarboxylic acid and lower alkyl esters thereof are optionally used.

Polyhydric alcohol components include ethylene, glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanenomethanol, pentaerythritol, trinotyrolpropane, and glycerin cap. is exemplified.

Furthermore, if necessary, 3-butenate-2-nol, 2-butenate-4-nol, 2,5-noty-3-hexene-2
・Olefinic glycol such as 5-diol, 5- in 1
It is also possible to use unsaturated polyhydric alcohols such as hexanoene-3,4-diol and 2,6-octane-4,5-diol.

In the present invention, it is advantageous to use polyhydric alcohol allyl ether in addition to the above-mentioned essential components in order to further impart air-drying properties to the bangu with improved curing speed, which is another purpose of the pond. The amount of the ether to be charged is not particularly limited, but is usually 0.02 to 40 mol%, more preferably 0.2 to 10% by mole based on the polyhydric alcohol component.
It is mole%.

If it is less than 0.02 mol%, the purpose of imparting air-drying properties cannot be achieved, and if it is more than 40 mol%, the surface hardening of the tape will be completed before the internal hardening, which will easily cause surface scratching, so it should be avoided. It is. Examples of polyhydric alcohol allyl ethers include glycerin moallyl ether, trinotyrol propane mo/allyl ether, trinotyrol propane noallyl ether, trinotyrole ethane monoallyl ether, trinotyrole ethane monoallyl ether, bentaerythritol mo/allyl ether, and benquerythritol. Noallyl ether, pentaerythritol triallyl ether, 1.2.6-hexanetriol diallyl ether, nrubitanmo/allyl ether, sorbitan noallyl ether, etc., but the present invention is not limited to these compounds. isn't it.

In this way, when producing 1 ml of unsaturated polyester IJ, the polyfunctional monomer, unsaturated dicarboxylic acid, acrylic monomer, acid components other than these, polyhydric alcohol, and, if necessary, polyhydric alcohol are added. React allyl ether. In addition, depending on the type of acrylic monomer, it is necessary to use a polyisocyanate-based compound, and examples of the polyisocyanate-based compound include tolylene twin cyanate, diphenylmethane-4,4-diisocyanate, l・5-S7tylene diisocyanate, hexamethylene diinocyanate, inphorone diisocyanate, 2,2,4-trinotylhexamethylene diisocyanate, linone diyne cyanate, xylylene diisocyanate, triphenylmethane -4,4,4'-) reinocyanate, 3,31-vitrylene-4,4'-diisocyanate, 3,3'-methylphenylmethane-4
Examples include -4'-diisocyanate, sulf7onylnoisocyanate, and polyhydric alcohol adducts thereof. Generally, the reaction begins with a polyfunctional monomer, an unsaturated dicarboxylic acid, other acid components, a polyhydric alcohol, and if necessary a polyhydric alcohol allyl ether, and then a combination of 1 chiltin oxide, antimony dioxide, and vinegar.
! 170-280°C in the presence of an esterification catalyst such as zinc
After esterification at a temperature of 0.5
Temperature 240-28 under vacuum of ~300 III g
Perform the synthesis reaction at 0°C. Examples of the integrated catalyst include germanium oxide, antimony dioxide, tetrabutyl titanate, dibutyltin oxide, and the like. The above-mentioned (c) acrylic monomer, or if necessary, a polyincyanate compound is added to the unsaturated polyester 4jI resin obtained in this way, and the reaction is continued to introduce an ethylenically unsaturated bond at the end of the 1j1 resin. .

Another essential requirement for the magnetic tape binder of the present invention is that the unsaturated polyester resin has a
) is to mix an ethylenically unsaturated monomer as an agent.

The blending amount of the JiI style based on the unsaturated polyester resin is 10 to 80% by weight, more preferably 20 to 60% by weight.
Although it is preferable to use 17, the present invention is not limited thereto. Typical examples of such Jiji forms include (meth)acrylic acid and its lower alkyl esters, sunalene, ethylene glycol, noethylene glycol,
Triethylene glycols such as 1,2- and 1,3-propanediol, 1,2- and 1,4-butaneol, hexamethylene glycol and other glycols (meth)7 acrylates, trinotialpropane, pentaerythritol, etc. Public danger (!l:l: Polyhydric alcohol - poly(ivy) acrylate corresponding to each category, fire-resistant l and 7 nobic acid,
One or more types of ester reaction products of polycarboxylic acids such as pimelic acid, 7-gelaic acid, and sebacic acid and glycidyl (ivy) acrylate can be optionally used.

Therefore, when applying the magnetic tape binder of the present invention to a base film, the above mixture is used as it is or after adjusting the concentration as appropriate. Solvents are not required for 9, but commonly used solvents such as acetone, trimethylketone, noethylketone, methylethylketone,
Ketones such as /tiltoisobutylketone, cyclohexane, esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl glycol mo/(or) methyl ether, ethylene glycol mo/(or di) ethyl ether, etc. ethers, aromatic HIR hydrogen compounds such as benzene, toluene, and xylene, and aliphatic hydrocarbons such as hexane and heptane may be used in combination.

In addition, the magnetic metal powder to be dispersed includes n-Fe2J, γ-
Fe. 0, or mixed powder thereof, doped with Kobal 1, CrO, Barium 7 Eft, Fe-Co. Co
-Ni. Fe-Co-[1. Fe-Co Bv Mn
-11i. Mn-81, FeCoV, etc. can be used arbitrarily. Note: The blending ratio of metal powder to unsaturated polyester + 61 fat is not particularly limited, but it is generally 58-90% by weight.

In order to take advantage of the progress of curing, which is a feature of the present invention, curing with electron beams, and in some cases β powder, gamma rays, and neutral RA shade radiation is employed. 0.5-10 for 1tm plate
More preferably 2 = 4 Pll radf than Mrad
), and the irradiation energy (acceleration voltage) is preferably 100 kV or more.

The magnetic tape binder of the present invention may optionally contain +iii ethylenic a; any known crosslinking agents other than saturated monomers, thickeners, plasticizers, lubricants, antistatic agents, wetting agents; Anti-blooming agents can be added. Examples of crosslinking agents include incyanate compounds, epoxy compounds, melamine resins, etc. Examples of crosslinking agents include ordinary polyester resins other than the unsaturated polyester resins mentioned above, ethyl cellulose, nitrocellulose, vinyl chloride-vinyl acetate copolymers, etc. As the plasticizer, butyl 7-crate, triphenyl phosphate, etc. are used.

Substrates include films, tapes, sheets, disks, cards,
Any material such as a drum may be used, and various materials are selected depending on the form. For example, when the substrate is in the form of a film or tape, films or tapes made of acetyl cellulose, polyester, polycarbonate, polyvinyl chloride, polypropylene, polyimide, etc. can be used.

As a means for applying the composition onto the substrate, a doctor knife method, a blade coating method, a reverse roll method, a gravure method, a cast neat method, a spray foot method, a 70-coater method, etc. are all employed.

After the composition is applied onto the substrate directly or via an anchor layer, it is subjected to a magnetic field orientation treatment using a twist/id coil or the like while the coating film is still wet, followed by hardening and drying.

The magnetic recording medium thus obtained is used for applications such as magnetic recording tapes, video tapes, tapes for electronic and measuring instruments, magnetic cards, and magnetic disks.

Next, the magnetic tape binder of the present invention will be explained in more detail by giving examples. However, unless otherwise specified, "parts" or "%" in the examples are based on weight.

Example 1 0.5 mol of cyethylene glycol diglycinol ether and 1.5 mol of acidic sodium sulfite were reacted at a temperature of 100°C for 6 hours using water as a solvent to obtain a sulfonic acid group-containing polyfunctional monomer ( In this case, a dihydric alcohol) was obtained.

Next, 0.7 mol of maleic anhydride, 7 novin fio, :3
mol, 0.5 mol of ethylene glycol, 0.5 mol of l-2-propylene glycol, 0.5 mol of diethylene glycol.
2 mol, 0.0 of the above sulfonic acid group-containing polyfunctional monomer
6 mol was charged, heated at 150-200℃ for about 3 hours, and further reacted at 200℃ for 4 hours to produce 3-5s + 1g of al.
After removing unreacted raw materials, the reaction was carried out until the acid value reached 5 or less.

1 mol of tolylene diisocyanate was reacted per mol of residual hydroxyl groups of this unsaturated polyester resin (3 hours at 60°C), and then 1 mol of 2-hydroxyethylnotacrylate was reacted per mol of residual incyanate groups (at 60°C). for 4 hours), and the desired binder resin was added.

Incidentally, as a result of IR analysis, the amount of residual incyanato groups in this resin was 3.0%.

The performance of the unsaturated polyester 17 (fat) as a binder for magnetic tape was evaluated according to the following.

0 parts of unsaturated polyester 0311iT, 40 BIS, 70 g of trinotyl propane triacrylate, and 100 parts of methyl ethyl ketone were heated in a ball mill for 70 hours, and then filtered and degassed to form a magnetic coating. It's σ.

This magnetic paint was applied by the doctor knife method onto a polyethylene telephoto film (stretched product) with a diameter of 7 mm and a diameter of 25 μ, and then subjected to an orientation treatment in a parallel magnetic field of 1000 oersted, followed by an electron green coating of 150 kV and an irradiation dose of 3 Mrnd. The curing speed, flatness of the tape surface, abrasion resistance, and magnetic properties were measured.

The WF titer method for each measurement type 11 is as follows.

・Curing speed: 150 kV, line speed of '3 Mrad irradiation condition C unit: m/+o i
n, ).

-1 Smoothness: Evaluated by 60°-60° reflection gloss rate.

・Abrasion resistance: Magnetic f! by Tate type abrasion test. 1.
We investigated the number of times it took for the layer to fall off.

-Magnetic properties: The ratio of saturation magnetism Bs to remanent magnetism Dr in the orientation direction, Br/Bs (squareness ratio) was measured.

The above results are shown in table fjs1.

Examples 2 to 8 In place of the sulfonic acid group-containing polyfunctional monomer used in Example 1, a polyfunctional monomer in which anopic acid noglycinole ester and 17 um of acidic sulfite were reacted (Example 2) )
, bisphenol A type/glycidyl ester and acidic sodium sulfite), a polyfunctional monomer made by reacting IJium (Example 3), a polyfunctional monomer made by reacting trinotylolpropane triglycidyl ester and acidic sodium sulfite. Monomer (Example 4), polyfunctional monomer made by reacting succinic acid mo/glycidyl ester with acidic sodium sulfite <yl+
a Example 5), p-Hydroxyamin Ω, polyfunctionality made by reacting fragrant acid monoglycity ester with acidic sodium sulfite!
11 R form (Example 6), 1+J polyfunctional monomer by reacting epichlorohydrin and acidic sodium sulfite and further hydrolyzing this with sodium hydrogen carbonate (Example 7)
), unsaturated polyester fJ (fat) was produced using the polyfunctional monomer (Example 8) obtained by reacting glycidol and sodium sulfite. The amount of preparation for the acidic number is 3 mol% in order
, 3 mol%, 2 mol%, 5 mol%, 5 mol%, 2 mol%
, 0.5 mol%.

Hereinafter, the performance as a magnetic tape binder was investigated according to Example 1. The results are shown in Table 1.

Example 9.10 1,6-hexasonol/acrylate/trimethylolpropane triacrylate (Example 9), 2-hydroxyethyl acrylate/in place of inbutyl acrylate/trimethylolpropane triacrylate used in Example 1 Performance was investigated in the same manner as on the same side except that trimethylolpropane triacrylate (Example 10) was used.

The results are shown in the PfSj table.

Comparative Examples 1 to 3 In Example 1, a saturated polyester resin containing a sulfonic acid group was used without using maleic anhydride and a monomer having an acrylic double bond at the molecular end (Comparative Example 1), maleic anhydride A monomer having an acrylic double bond at the molecular end was bonded to the 11t without using only an acid, and a saturated polyester resin containing a sulfonic acid group was used (Comparative Example 2), and the sulfonic acid in Example 1 was used. The performance as a magnetic tape binder was investigated using 5-sonoosulfoiiso7curic acid (Comparative Example 3) instead of the salt W-containing polyfunctional illumer.

These results are summarized in Table 1.

Example If, +2 In Example 1, 0.4 mol of glycerin monoallyl ether was further added as a glycol component to obtain an unsaturated polyester resin (Example 11), and 0.3 mol of trinotyolpropane monoallyl ether was used. For the product (Example 12), a bindu for magnetic tape was manufactured and its performance was investigated according to Example j.
, (Example 12), smoothness is 99 (Example 11), 98
(Example 12Li4 abrasion resistance is 910 (Example 11L90)
0 (Example 2), magnetic properties are 0.135 (Example 11)
), 0.85 (Example 12), and this binder did not require vacuum even when irradiated with an electron beam and had excellent air drying properties.

(Margin below)

Claims (1)

[Claims] 1. ('a) A polyfunctional monomer containing a sulfonic acid group obtained by reacting an epoxy group-containing compound with an acidic sulfite and an unsaturated nocarboxylic acid are used as one component of the polyester resin. , and an unsaturated polyester resin having an acrylic monomer bonded to the terminal end of the V(b) ethylenically unsaturated monomer for a magnetic tape. 2. (a') A polyfunctional monomer containing a sulfone m base obtained by reacting an epoxy resin-containing compound with an acidic sulfite, an unsaturated nocarboxylic acid, and a polyhydric alcohol 7lyl ether is used as a component of the (a') polyester resin. , and I
A bindu resin composition for a magnetic tape, the main ingredients of which are an unsaturated polyester resin in which an acrylic 1-QtffL body is bonded to an I-fat terminal, and (b) an ethylenically unsaturated monomer.