RU2001046C1 - Butyl acrylate-acrylonitrile-ethylene glycol monomethacrylate copolymer as synthetic adhesive for magnetic tape coatings - Google Patents

Abstract

Butyl acrypate copolymer. acrylonitrile and ethipenglycol monomethacrylate of the general formula NCHS (CH2-i-) n (-CH2-i-) m (-CH2-i-) Ki С 0ONC 0 V-СЧ0-СН -СН -ОН where p - 55 - 72%, m - 20 - 30%. K - 8 - 15%, with a number average mopm of 10,000 - 80,000. As a polymer binder for the working layers of magnetic information carriers, 2 tab.

Description

The invention relates to polymer chemistry and is a copolymer of butyl acrylate, acrylonitrile and ethylene glycol monomethyl acrylate. The copolymer can be used as a polymer binder for the working layers of magnetic media.

A copolymer of ethyl acrylate, acrylonitrile and methacrylic acid is known, taken in a molar ratio of 70: 29: 1. Said aqueous emulsion copolymer is used to render paper resistant to oils, fats, and greases. As a filler, 10-3% hydrophilic inorganic material is introduced into the emulsion.

The closest in structure to the claimed is a copolymer of butyl acrylate, acrylonitrile and methacrylic acid, containing 35 wt. Acrylonitrile, May 60, h. butyl acrylate and 5 m.h. methacrylic acid. The copolymer is used as a binder for impregnation of a skin-like sheet made of polyacrylonitrile fibers. In use, the copolymer is mixed with a water-soluble phenol-formaldehyde resin and cured on smooth rollers at 130 ° C.

The specified copolymer cannot be used as a polymer binder for the working layers of magnetic information carriers, because the number of carboxyl groups is insufficient to form the required number of cross-linking bonds during curing, which provide rigidity, hardness and chemical resistance of the working layer.

The aim of the invention is the synthesis of a ternary copolymer of a certain composition containing a unit of butyl acrylate, acrylonitrile, ethylene glycol monomethacrylate, which can be used as a polymer binder for the working layers of magnetic information carriers - magnetic tapes for household recording, computer tapes, household tapes video recordings.

The goal is achieved by the described copolymer of butyl acrylate, acrylonitrile and monomethacrylate ethylene glycol of the General formula

n i

n

I

SH

Kngs-) and 1-cngs-) t (-сн7-с-) k,

With CNC

vo-c ,, H9Xo-sn2-sn7-he

where n is May 72-55. %; m-May 20-30. %; K-8-15 May.%;

with a number average mol.m. 10000-80000.

The presence of ethylene glycol butyl acrylate, acrylonitrile and monomethacrylate in the copolymer provides high physicochemical and mechanical properties of the polymer film forming the working layer of magnetic tapes.

The synthesis of the ternary copolymer is carried out in solution at a temperature of + 70 ° C under

become the initiators of the radical type.

To prove the structure of the copolymer, IR spectra were recorded.

Infrared (IR) absorption spectra of polymers were obtained on an IR-435 spectrophotometer (Shlmadzu) in the region of 4000-400 cm. To record the spectra, the samples were prepared in the form of films on KRS-5 plates. Films were applied directly from the polymer and from polymer solutions in chloroform, dimethylformamide.

In the IR spectra there are no absorption bands of valence and deformation co

vibrations of groups and CH2 of CH-starting monomers: butyl acrylate, acrylonitrile and ethylene glycol monomete acrylate. This indicates that. that the copolymerization process went through with the opening of the bonds of the above monomers.

The IR spectra of the polymer contain intense absorption bands of 1725, 1260, 1170 (Table 1), characteristic of

acrylate units in polymers, and the presence of medium intensity bands of 835 cm, 935 with a shoulder of 955 cm and 1064 cm shows that the monomer units of butyl acrylate are included in the composition of the copolymer. At the same

the time the presence of absorption at 1385, 1025, 740 cm, as well as a change in the ratio of intensities and complication of the shape of the contours of the absorption bands in the region of stretching vibrations of С-О-С groups of 11001300 cm, allows us to conclude that the structure of the copolymer contains units that are similar in structure to ethyl methacrylic acid ester. Wide absorption at 3500 cm 1 is caused by stretching vibrations of the associated hydroxyl groups; a narrow peak of medium intensity at 2240 cm 1 - by stretching vibrations of C N-rpynn monomer units of acrylonitrile.

Thus, the IR spectra of the polymer in question contain the absorption bands of all three comonomers used in its preparation. Preservation of absorption bands characteristic of each of the comonomers in polymer extracts,

carried out with different solvents confirms that it is a copolymer.

The content of hydroxyl groups in the copolymer was determined by a known method.

EXAMPLE 1 A glass reactor equipped with a jacket for supplying coolant or heating is used for copolymerization. The sanded top cover has openings for a stirrer, thermocouples, a reflux condenser, taps for supplying reaction components and nitrogen blowing. The copolymerization is carried out in an organic solvent at a temperature of -60- + 80 ° С under the influence of radical type catalysts,

The order of loading the components is as follows.

Under stirring, a solvent, monomers, initiator are charged into the reactor under a stream of nitrogen. Set the desired reaction time and temperature. To determine the characteristics of the copolymer, either a polymerizate is used, or a part of the polymer is precipitated from the reaction mixture with ethanol, charged with an antioxidant and dried to constant weight in a vacuum oven at a temperature of 60 ° C and a residual pressure of 10-20 mm Hg.

The polymerization recipe, parts by weight

Butyl acrylate 72

Acrylonitrile 20

Monomel krilat

ethylene glycol 8

Ethyl acetate 150

DAK1.0

Reaction temperature, ° С60

Duration

reaction h20

Conversion Monomer.

wt.% 99.8

The number average molecular weight is 80,000

The content of hydroxyl groups, wt.% 1,6

PRI me R 2. The order of loading and polymerization is similar to example1.

The polymerization recipe, parts by weight

Butyl acrylate55

Acrylonitrile30

These monomethacrylate

langlycol 15

Butyl acetate100

DAK1.0

Reaction temperature. ° C70

The duration of the reaction, h20

Conversion of monomers, wt.% 100 Number average molecular weight

mass60000

The content of hydroxyl groups, wt.% 2,4

Example 3, The procedure for loading and polymerizing is similar to Example 1.

The polymerization recipe, parts by weight Butyl acrylate65

Acrylonitrile, 20

monomethacrylate-ethylene glycol 15

Methyl ethyl ketone 400

Porophore 4A4C, wt.% 3.0

Temperature, ° С80

The duration of the reaction, h18

Monomer conversion, wt.% 99.8 The number average molecular weight of 100,000 Hydroxyl groups, wt.% 2,4 EXAMPLE 4. The loading procedure and polymerization are similar to Example 1.

The polymerization recipe, parts by weight Butyl acrylate 60

Acrylonitrile 30 100

Ethylene glycol monomethacrylate 10 Cyclohexanone 150

Aaopentanol Ts, wt.% 1,0

Reaction temperature, ° C70 Duration of reaction, h 20 Conversion of monomers, wt.% 100.0 Number average molecular weight 80,000 Hydroxyl content, wt.% 2.8 EXAMPLE 5 Order of loading and polymerization as in Example parts by weight

Butyl acrylate 60

Acrylonitrile 30 I 100

Monomethacrylate

ethylene glycol 10

Ethyl acetate / butyl acetate (60:40 vol.%) 150 DAK, wt.% 1,0. Reaction temperature, ° С 70 Reaction time, h 18 Monomer conversion, wt.% 100 Number average molecular weight 31000 Hydrophilic groups, wt.% 2.1 To obtain a polymer film forming the working layer of magnetic tapes and evaluate the quality of the binder polymer the resulting composition (copolymer solution in a solvent of a given concentration) is mixed with a curing agent - hexamethoxymethylmelamine (resin GM-3),

To lower the temperature and cure rate, a dodecylbenzenesulfonic acid catalyst is used.

The reaction mass is thoroughly mixed, incubated for 10 minutes to remove air bubbles, the films are cast and solidified at a temperature of 120 ° C for 2 hours.

Binder film polymers must possess the necessary adhesive properties to a polyethylene terephthalate base, maximum cohesive strength, elasticity, hardness, and stability under extreme climatic conditions.

The test results are presented in table. 2.

(56) U.S. Patent No. 2889299, cl. 260-26.6, 1959.

US patent No. 2970079, CL. 162-164,

1961.

Table 1

The position of the main absorption bands in the IR spectra of the copolymers of butyl acrylate, acrylonitrile, ethylene glycol monomethacrylate and their assignment.

Physico-mechanical properties of polymer films

) Conditions for curing polymer films:

polymer, wt.% 100

hexamethoxymethylmelanin, wt.% 10.0

dodecylbenzenesulfonic acid, wt.% 1,0

temperature, ° С120

cure time, h2.0

) Butyl acrylate copolymer. acrylonitrile and methacrylic acid) Saponified copolymer of vinyl chloride and vinyl acetate in a composition with rubber SKN-40.

Claims (1)

The claims Butyl acrylate copolymer. acrylonite and ethylene glycol monomethacrylate shaved formula H I (-CH - C -) l СООС4Н9 Continued 1 Table 2 N CN SN to (-CHj- (j-) K. СООСН2СН20Н where n - 55 - 72%; with an average mol.m. 10000 - 80,000 in quality m - 20-30%; polymer binder for working layers - 8-15%, magnetic media.