JPS59179517A - Epoxy modified polyurethane resin composition - Google Patents

Abstract

PURPOSE:A composition having a great number of OH groups, improved dispersibility of pigment or filler, improved film strength during curing, and heat distortion resistance, obtained by subjecting epoxy group of epoxy modified polyurethane with an amine or carboxylic acid to form OH group. CONSTITUTION:An epoxy compound [e.g., compound shown by the formula I (R<1> and R<2> are H, or CH3; X is H, CH3, Cl, Br, or I; n>=), formula II (Y is S, or SO2; m>=1), etc.] having two or more OH groups in the molecule on average is reacted with a polyol (e.g., polyester polyol having 500-5,000 molecular weight) and an isocyanate compound (e.g., hexamethylene diisocyanate, etc.) to give an epoxy modified polyurethane. The epoxy group of the epoxy modified polyurethane is partially or totally subjected to ring opening with an amine (e.g., diethylamine, etc.) and/or a carboxylic acid (e.g., acetic acid, succinic acid, etc.). USE:Preferably as a binder for magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to epoxy-modified polyurethane resin compositions having a large number of OH groups.

Conventionally, a simple blend of epoxy resin and urethane resin has been known, but it has the disadvantage that the dispersibility of pigments and fillers is poor and the toughness of the coating film is poor when cured. In other words, when an epoxy group is cured, an OH group remains, and when an OH group is crosslinked with an isocyanate compound, an epoxy group remains, so it is necessary to use separate curing methods. Therefore, due to differences in curing speed, etc., the resulting resin is Poor balance in strength, flexibility, and hardness. In addition, since the number of OH groups is small before curing, the dispersibility of pigments and fillers is poor, making it even more likely that variations in properties will occur.

An object of the present invention is to provide an epoxy-modified polyurethane resin composition that provides a cured resin with an excellent balance of strength, flexibility, hardness, etc.

Another object of the present invention is to provide an epoxy-modified polyurethane resin composition that has a large number of OH groups and has excellent dispersibility of pigments and fillers.

In the present invention, a part or all of the epoxy groups of an epoxy-modified polyurethane obtained by reacting an epoxy compound, a polyol, and an isocyanate compound each having two or more OH groups in the molecule on average are opened with amines and/or carboxylic acids. The present invention relates to an epoxy-modified polyurethane resin composition in which OH groups are formed by ring formation.

The composition of the present invention has the characteristics of both the toughness of polyurethane and the hardness and adhesive strength of epoxy resin, and can be cured with an isocyanate compound. In addition, it has excellent dispersibility for pigments, fillers, and other magnetic powders that have a large number of OH groups in their molecules.

The composition of the present invention can be used in various fields, such as paint vehicles, magnetic tape binders, coating agents,
Used as adhesive, etc. It is particularly effective in fields requiring dispersibility and affinity with fillers that require wear resistance, and is especially suitable as a binder for magnetic tapes.

In the present invention, first, an epoxy compound, a polyol, and an isocyanate compound having an average of two or more OR groups in the molecule are reacted to obtain an epoxy-modified polyurethane. In this case it is also optional to use chain extenders.

As the epoxy compound, preferably a bisphenol type epoxy resin is used, and an epoxy resin represented by the following formula is particularly suitable.

(R1 and R2 are each hydrogen or methyl group, X is hydrogen,
(Methyl group, chlorine, bromine or iodine, n is a number of 1 or more) ;H (Y is S or SO2, m is a number of 1 or more) Specific examples of trade names include Epicote 828.838. 10
01.1002.1003.1004.1007.10
09 (hereinafter referred to as shell chemical tank), etc. In addition, other epoxy compounds include epoxy resins containing bromine,
For example, Epicote 1045-B-80, 1046-B-
80゜1050 (manufactured by Yuka Shell Epoxy Co., Ltd.), Sumiepoxy ESB-3'40.400.500.700
．． 715 (manufactured by Sumitomo Chemical Industries), and the like.

In the present invention, the polyol has a molecular weight [250
0 to 5000, various polyester polyols, polyether polyols, and other polyols can be used.

Specific examples of polyester polyols include adihate-based polyols such as polyethylene adipate polyol, polybutylene adipate polyol, and polyethylene propylene adipate polyol, terephthalic acid-based polyols (e.g., Toyobo Co., Ltd., product names Byron RUX, Byron RV-20OL), and polyester polyols. Specific examples of polyether polyols include caprolactone polyol (eg, Daicel Chemical, trade names Plaxel 212, Plaxel 220), and polyoxyethylene glycol, polyoxypropylene polyol, polyoxytetramethylene polyol, and the like.

In addition, other polyols include polycarbonate polyol (e.g., Bayer AG, West Germany, trade name Desumophen 2020E), polybutadiene polyol (e.g.,
Nippon Soda, product name G-1000, G-2000, G-3
000, Idemitsu Petrochemical, trade name Po], y bd R
-45HT), polypentadiene polyol, castor oil polyol, etc., and one type or two or more types can be used.

The isocyanate compound used in the present invention may be any polyisocyanate known in polyurethane chemistry, such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IP
DI), 4,4'-dicyclohexylmethane diisocyanate (HMDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4/- Diphenylmethane diisocyanate (MDI), carposiimide modified M
DI, polymethylene polyphenyl polyisocyanate (
PAPI), orthotoluidine diisocyanate (TO
DI), naphthylene diisocyanate (NDI),
Examples include xylylene diisocyanate (MDI) and lysine diisocyanate (LDI), and one type or two or more types can be used.

Examples of the chain extender include di- to hexafunctional polyols with a molecular weight of 500 or less and diamines having a primary or secondary terminal amino group with a molecular weight of 500 or less. Suitable chain extenders include, for example, (a) ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 2,3-butanediol, 1,3-propylene glycol, 1 , 6-hexanediol, glycerin, trimethylolprohane, hentaerythritol, sorbitol, 1,4-cyclohexanediol, 1,4-cyclohexane dimetatool, metaxylylene glycol, baraxylylene glycol, and other polyols (b)
Diamines such as hydrazine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, and 1,14-cyclohexanediamine (C) Alkanolamines such as ethanolamine, jetanolamine, and triethanolamine (d) Hydroquinone,
Polyols with a molecular weight of 500 or less obtained by adding propylene oxide and/or ethylene oxide to pyrogallol, 4,4'-isopropylidene diphenol, aniline, and the above polyols, diamines, and alkanolamines in any order, etc. Can be mentioned.

Epoxy-modified polyurethane is synthesized using the above-mentioned components, and the NCOIndex is usually about 0.
It is preferable to carry out the reaction in the range of 7 to 1.2, preferably about 0.9 to 1.1.

In the present invention, the epoxy groups of the above-mentioned epoxy-modified polyurethane are further reacted with amines and/or carboxylic acids to open the ring and generate OH groups to obtain the desired epoxy-modified polyurethane resin composition.

The amines are preferably compounds containing secondary amino groups, such as dialkylamines such as diethylamine, dipropylamine, dibutylamine, N-methylethanolamine, N-7:methylethanolamine, jetanolamine, dibrobanol. Alkanolamines such as amines, and carboxylic acids such as acetic acid, propionic acid,
Stearic acid, succinic acid, adipic acid, maleic acid, benzoic acid, phthalic acid, phenylacetic acid, hydroxyacetic acid (glycolic acid), lactic acid, 2,2-dimethylolpropionic acid, 9,10,12.13-tetraoxyoctadecane Examples include acids, acetic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, and the like. These amines and carboxylic acids can be used alone or in combination.

In the above-mentioned ring-opening reaction of the present invention, part or all of the epoxy group can be ring-opened, and the amount of amines and/or carboxylic acids is usually about 1 equivalent or less, preferably about 0.2 times the amount of the epoxy group. It is better to use ~1 equivalent. The reaction is usually carried out at about 20 to 180 °C, preferably about 100 to 15 °C.
It is best to do this at 0°C.

The ring-opened modified polyurethane resin of the present invention has a large number of OH groups in its molecules and has extremely good dispersibility of pigments, magnetic powders, other fillers, and the like. The number of OH groups is usually preferably 3 or more, generally 6 to 30, particularly preferably 10 to 2.
It is preferable to have 0 OH groups.

In the present invention, a polyfunctional isocyanate compound can be further blended with the epoxy-modified polyurethane resin, and when this composition is cured, excellent film strength and heat deformation resistance can be obtained.

As the polyfunctional isocyanate compound in the present invention, a polyisocyanate having two or more functional groups can be used. Preferred specific examples include various isocyanate compounds that can be used in the production of the epoxy-modified polyurethane and a trifunctional isocyanate obtained from trimethylolpropane and TDI (trade name Desmodur L).
, West Germany, Bayer AG), trifunctional isocyanate (trade name: Desmodur N-75), also manufactured by Bayer AG
, R9, H, etc.), polymeric polyisocyanate (
PPI), etc.

EXAMPLES The present invention will be described in detail below with reference to Examples, Comparative Examples, and Test Examples. Note that parts and % simply indicate parts by weight and % by weight.

Example 1 Byron RV-200L was placed in 21 separable flasks equipped with a thermometer, stirrer, nitrogen gas introduction tube, and condenser.
(OH value 56.1) '280g polycaprolactone diol COH value 56.1) 120g Epicote 1001 36 gI
PDI 6
4.0g cyclohexanone 15
2 g was weighed out and reacted for 2 hours at 110'C in a stream of dry nitrogen. Then 192 g of cyclohexanone and 1.6-
Add 7.1 g of hexanediol and further heat at 110°C for 1
After heating for an hour, 0.13 g of dibutyltin dilaurate was added and reacted for 2 hours.

This epoxy-modified polyurethane solution and 8.4 g of jetanolamine were reacted at 130'C for 2 hours, and after the 905σ absorption derived from the epoxy group disappeared in the infrared absorption spectrum, the solution was cooled to 70°C, and methyl ethyl ketone (
Add 429g of MEK).

The resulting solution had a solid content of 40%, a viscosity of 320 mPa' at 25°C, and an OH group concentration of 0.47 meq/g polymer.

Comparative Example 1 Vylon RV-200L 392 g Polycaprolactone Diol 168 g IPDI
78g cyclohexanone 194g The above mixture was heated at 110°C for 2 hours.
Allow time to react. Next, 237 g of cyclohexanone and 9.8 g of 1,6-hexanedio-/l were added.
After heating for 11O'ct'1life, 0.16g of dibutyltin dilaurate was added and reacted for 2 hours. After cooling the obtained polyurethane solution to 70°C, 541 g of MEK was added to give a solid content of 40% and a viscosity of 430 mPa''S/25°C.
(7) A polyurethane solution without OH groups was obtained.

Test Example 1 100 parts of each of the polyurethane solutions of the water resistance test examples and the ratio 1 bite example and Desmodur N-75 (10 parts) were mixed and applied to a thickness of 0.05 mm on an iron plate that had been degreased with toluene. After drying the solvent, it was cured at 110'C for 2 hours. After being left for one week, it was immersed in a constant temperature water bath at 60°C for 1°, and its surface condition was visually observed.

As a result, no blisters were observed in the coating film of Example 1, but some blisters occurred in the coating film of Comparative Example 1.

Test Example 2 100 parts of each polyurethane solution of the dispersibility test example and comparative example and pigment (Pigmotex Yellow H1210
After mixing 20 parts (manufactured by Isumi Shiki Co., Ltd.) in a ball mill for 4 hours, it was spread onto a polyester film of 5 μm using a doctor blade.
After drying, the surface gloss was measured using a gloss meter 5-60 manufactured by Toyo Seiki Co., Ltd.

As a result, Example 1 had a gloss of 95, but Comparative Example 1
So it was 65.

(Above) Patent applicant: Toyo Rubber Industries Co., Ltd. Agent: Iwao Tamura, patent attorney

Claims (4)

[Claims] (1) Part or all of the epoxy groups of the epoxy-modified polyurethane obtained by reacting an epoxy compound, a polyol, and an isocyanate compound each having two or more OH groups in the molecule on average are opened with amines and/or carboxylic acids. An epoxy-modified polyurethane resin composition in which OH groups are formed by ring formation. (2) The epoxy compound has the formula (R1 and R2 are each hydrogen or methyl group, X is hydrogen,
The composition according to claim 1, which is a compound represented by a methyl group, chlorine, bromine, or iodine, where n is a number of 1 or more. (3) The composition according to claim 1, wherein the epoxy compound is a compound represented by the formula (Y is S or SO2, m is a number of 1 or more). (4) The composition according to claim 1, further comprising a polyfunctional isocyanate compound.