JPH038372B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermosetting polyurethane resin composition, and more specifically to a thermoplastic polyurethane resin having -SO ₃ The object of the present invention is to provide a thermosetting resin comprising a low molecular weight polyisocyanate having the following properties and imparting improved properties such as pigment dispersibility and moist heat resistance. Thermoplastic polyurethane resin has high elasticity, flexibility,
Taking advantage of its excellent properties such as abrasion resistance, cold resistance, and strength, its organic solvent solution is widely used for synthetic leather, paints, adhesives, etc. However, thermoplastic polyurethane resins have the drawback of being inferior in heat resistance, hydrolysis resistance, and moist heat resistance. In recent years, thermoplastic polyurethane resins have been actively developed for use in printing inks, magnetic paints, conductive resins, magnetic rubbers, etc.
During use, the dispersibility of magnetic powder is poor, and due to this, it is currently difficult to obtain products with satisfactory electromagnetic properties. Conventionally, various methods have been proposed to eliminate these drawbacks, but the high elasticity, abrasion resistance, flexibility,
It has been impossible to improve the above drawbacks without impairing properties such as cold resistance and strength. The inventors of the present invention have conducted extensive research on methods for improving the above drawbacks without impairing the excellent properties of thermoplastic polyurethane resins, and have found that -SO ₃ X (where X is an alkali metal atom) and -SO 3 Pigment dispersibility is improved by using a thermoplastic polyurethane resin (A) into which tertiary hydroxyl groups have been introduced, and the moist heat resistance and resistance of the urethane resin after curing are improved by using a low molecular weight polyisocyanate in combination. The present invention was completed by discovering that durability such as abrasion resistance can also be improved. That is, the present invention provides a thermoplastic polyurethane resin (A) containing -SO ₃ A thermosetting polyurethane resin composition comprising B) is provided. Thermoplastic polyurethane resin used in the present invention
(A) particularly has a number average molecular weight of 10,000 to 50,000, more preferably 15,000 to 45,000. In addition, the thermoplastic polyurethane resin → the number of -SO ₃ More preferably, it is about 1 to 20, and X is an alkali metal atom, preferably Na or K. In other words, if the number average molecular weight is less than 10,000, the mechanical properties, abrasion resistance, and moist heat resistance of the polyurethane resin will be inferior, and if it is more than 50,000, the abrasion resistance of the polyurethane resin will be improved, but the pigment dispersibility will be extremely deteriorated, making it difficult to form into a paint. This often leads to situations like this. Also, − in one molecule
If the number _of SO ₃ Furthermore, if the number of tertiary hydroxyl groups in one molecule is 0.2 or less, it is difficult to improve the heat and humidity resistance of the urethane resin after curing. Note that both ends of the thermoplastic polyurethane resin used in the present invention may be an isocyanate group or a hydroxyl group, or one end may be an isocyanate group and the other end may be a hydroxyl group. _The thermoplastic polyurethane resin (A) containing _{-SO 3} Obtained by polymerizing (A ₂ ) alone or a mixture of the diol and a polyol (A ₃ ) containing a tertiary hydroxyl group with a number of hydroxyl groups of 2 or more and not containing a -SO ₃ X group in the molecular chain. and (A ₁ ) and (A ₂ ) polymer and (A ₁ )
The polymers of (A 3 ) and (A ₃ ) may be prepared separately and then polymerized, or they may be used as a mixture. Examples of the organic diisocyanate (A ₁ ) include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, xylene diisocyanate, cyclohexane diisocyanate, toluidine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenyl diisocyanate, enylmethane diisocyanate, p-phenylene diisocyanate,
Mention may be made of m-phenylene diisocyanate, 1,5-naphthylene diisocyanate and mixtures thereof. Among these, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and mixtures thereof are preferred. Diols (A _{2 )} containing -SO ₃ Dibasic acids such as sulfosuccinate - sodium sulfonate or their esters and succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid,
Dibasic acids such as suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid and mixtures of these acid esters and glycols having 2 to 10 carbon atoms. For example, ethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 2,3-butylene glycol, 1,4-butylene glycol,
2,2'-dimethyl 1,3-propanediol, diethylene glycol, 1,5-pentamethylene glycol, 1,6-hexamethylene glycol,
Examples include polyester diols having a molecular weight of 500 to 6,000 obtained by polycondensation with glycols such as cyclohexane-1,4-diol and cyclohexane-1,4-dimethanol alone or with a mixture thereof. Further, a mixture of dialkanol sulfoisophthalate and dialkanol sulfosuccinate and unreacted glycol obtained by transesterification reaction between the ester of sodium sulfonate and excess glycol having 2 to 10 carbon atoms. can be mentioned. -SO ₃ Polyols containing tertiary hydroxyl groups (A ₃ ) that do not contain
~6000 diols may be mixed, or low molecular weight diols having 2 to 10 carbon atoms, triols having 4 to 10 carbon atoms having a tertiary hydroxyl group in the molecular chain, and these triols can be used. Terminal hydroxyl group and at least one tertiary hydroxyl group in the molecular chain
Polyols such as polyether polyols and polyester polyols having a molecular weight of 500 to 6,000 or more may be used alone. Examples of diols having a linear terminal hydroxyl group and having a molecular weight of 500 to 6,000 include polyester polyols and polyether polyols. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. The polyester polyol has 2 to 10 carbon atoms as described above.
with a glycol alone or in a mixture having -
Examples include polyester polyols obtained by polycondensing the aforementioned dibasic acids that do not contain an SO ₃ Examples include polycaprolactone diols subjected to ring-opening addition polymerization in the presence of. As the low molecular weight diols having 2 to 10 carbon atoms, the glycols used in the production of the polyesters may be used alone or in mixtures. Further examples include diols in which 2 to 4 moles of ethylene oxide and propylene oxide are added to bisphenol A, hydroquinone, and the like. Among the above, aliphatic diols are preferred for both diols with a molecular weight of 500 to 6,000 having a linear terminal hydroxyl group and low molecular weight diols having 2 to 10 carbon atoms. 4 to 10 carbon atoms with tertiary hydroxyl group in the molecular chain
As the triol, for example, 1,2,3-hydroxy-2-methyl-propane, 1,2,3-hydroxy-2-ethylpropane, 1,2,4-hydroxy-2-methylbutane, 1,2,5 Monomers or mixtures such as -hydroxy-2-methylpentane, 1,3,5-hydroxy-3-methylpentane, and 1,3,6-hydroxy-3-methylhexane are mentioned. In addition, the molecular weight having the above-mentioned tertiary hydroxyl group is 500~
Examples of polyether polyols include polypropylene ether polyol, polyethylene polyol, and polybutylene polyol, which are obtained by adding propylene oxide, ethylene oxide, or butylene oxide to polyol 6000. Further, there are polyesters obtained by polycondensing a mixture of a triol having a tertiary hydroxyl group and the low molecular weight glycol with the dibasic acid and these acid esters and acid halides. Examples include polycaprolactone polyols obtained by ring-opening addition polymerization of a lactone such as caprolactone in the presence of a mixture of the triol and glycol. It is essential that the hydroxyl group in the molecular chain of the polyol be tertiary. Primary and secondary hydroxyl groups have faster reactivity with isocyanates than tertiary hydroxyl groups, leading to higher molecular weight or reticulation of polyurethane, making it difficult to produce thermoplastic polyurethane resin. This is due to Furthermore, when producing the thermoplastic polyurethane resin used in the present invention, the OH/NCO molar ratio of polyol and organic diisocyanate is set at 0.85 to 0.85, taking into account impurities (moisture, acid, hydrolyzed chlorine, etc.) in each raw material. 1.15/1.00, preferably 0.95 to 1.05/1.0. If it deviates from these ranges, it is not preferable because the excellent performances required by the present invention cannot be obtained. If necessary, a catalyst and various stabilizers can be used in the thus obtained thermoplastic polyurethane having SO ₃ X groups and tertiary hydroxyl groups.
Examples of catalysts include tertiary amines such as triethylamine and triethylenediamine, morpholine, N-
Examples include nitrogen compounds such as methylmorpholine, metal salts such as potassium acetate and zinc stearate, and organometallic compounds such as dibutyltin dilaurate and dibutyltin oxide. The above-mentioned properties of the thermoplastic polyurethane can be significantly stabilized by incorporating stabilizers against ultraviolet light such as substituted benzotriazoles and stabilizers against thermal oxidation such as phenol derivatives. Furthermore, in producing the above-mentioned thermoplastic polyurethane resin, conventionally known methods can be used, and if desired, after sufficiently mixing the reactants in the presence of a catalyst, the reaction mixture is poured into a flat plate or flat plate. A method of pouring it onto a surface, heating it, and then crushing it after flowing it,
A method for injecting the reaction mixture into an extruder and a solution for reacting in an organic solvent of a single or mixed solvent system such as dimethylformamide, toluene, xylene, benzene, dioxane, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, etc. Conventional manufacturing methods such as reaction methods can be used. Among these, when used for magnetic paints, including those for dissolving and diluting solid thermoplastic polyurethane resin, toluene, xylene, benzene, etc., which have low affinity and solubility with water, and cyclohexanone, methyl ethyl ketone, which have excellent solubility, , methyl isobutyl ketone, ethyl acetate, butyl acetate and the like are preferred. In the present invention, it is essential that the thermoplastic polyurethane resin is finally used after being cured with a suitable curing agent, and low molecular weight polyisocyanate is most suitable as the curing agent. Examples of the low molecular weight polyisocyanate (B) having two or more isocyanate groups used in the present invention include organic diisocyanates used in the production of the thermoplastic polyurethane resin and low molecular weight polyisocyanates having two or more isocyanate groups (for example, low molecular weight Examples include compounds in which a polyol is terminally isocyanate grouped with an isocyanate compound, and have a molecular weight of about 150 to 7,000. Examples of low molecular weight polyisocyanates having two or more isocyanate groups include the following compounds. Commercially available products of this type include Burnock D-750,
Crisbon NX (Dainippon Ink & Chemicals Co., Ltd. product),
Desmodeur L (Sumitomo Bayer product), Coronate L (Nippon Polyurethane product), Takenate
Examples include D102 (product of Takeda Pharmaceutical Co., Ltd.). Commercial product Burnock D-950 (Dainippon Ink & Chemicals Co., Ltd. product) Triphenylmethane 4,4',4''-triisocyanate

【formula】 Commercial product Desmodeur R (manufactured by Sumitomo Bayer)

[Formula] Commercial product Desmodeur RF (manufactured by Sumitomo Bayer) The ratio of the thermoplastic polyurethane resin (A) and the low molecular weight polyisocyanate (B) is not particularly limited, but preferably 100 parts of the thermoplastic polyurethane resin. By adding 3 to 40 parts of the above-mentioned low molecular weight polyisocyanate to the resin and curing it, the mechanical strength, abrasion resistance, and
Heat resistance, heat and humidity resistance, solvent resistance, and adhesion to substrates can be greatly improved. In addition, if necessary for the above thermosetting urethane resin composition, commonly used thermoplastic polyurethane resins, vinyl chloride-vinyl acetate copolymers, cellulose resins, vinyl chloride polymers, polyvinyl butyral resins, thermal Commercially available products such as plastic polyester resin, vinyl chloride-vinyl propionate copolymer, epoxy resin, and phenoxy resin can be used in combination to improve the dispersibility of pigments, adjust the hardness of resin, etc. Can be done. The thermosetting polyurethane resin composition obtained according to the present invention has excellent properties such as excellent pigment dispersibility, heat and humidity resistance, abrasion resistance, fluidity, and permanent elongation, so that it can be used for various purposes. For example, it can be used for various printing inks, magnetic rubber, various paints, magnetic recording binders, conductive resins, adhesives, film materials, sheet materials, materials for industrial molded products such as automobile parts, etc. Due to its characteristics, it is especially suitable for magnetic recording media. A thermosetting polyurethane resin composition useful as a binder. Next, the present invention will be explained with reference to examples, but these are only one aspect and the present invention is not limited only by the examples. In addition, all "parts" in the text indicate weight standards. (Synthesis Example of Thermoplastic Polyurethane Resin) Examples 1 to 3 and Comparative Examples 1 to 5 Molecular weight 2000 (adipic acid/5-sodium The molar ratio range of sulfodimethyl isophthalate is shown in Table 1. 1 mol of polyester diol with hydroxyl value 56.1), dibutyl 1,3,5-hydroxy-3-methylpentane (the blending ratio is shown in Table 1) After mixing 0.1 part of tin dilaurate, 4,4'-diphenyl-
Methane diisocyanate NCO/OH=1.00/
They were added at a molar ratio of 1.02. Before mixing these components, the polyol and isocyanate were heated to 80°C and 50°C, respectively. The isocyanate was added to the polyol mixture with mechanical mixing for about 1 minute to ensure intimate contact of the ingredients. Next, this reaction mixture was poured into a vat heated to 120°C for 1 hour.
Further, the mixture was allowed to stand at 100°C for 20 hours to complete the reaction, and a thermoplastic polyurethane resin was prepared. - of the obtained thermoplastic polyurethane resin
Table 1 shows the measurement results of the number of SO ₃ Na groups, the number of tertiary hydroxyl groups, solubility in organic solvents, number average molecular weight, and dispersibility of the magnetic powder.

[Table] The method for measuring the thermoplastic polyurethane resin in Table 1 is described below. (Note 1) Measurement of the number of -SO ₃ groups contained; elemental analysis method The pretreatment was to convert to SO ₄ ^-- by the oxygen flask combustion method, and this group was measured by the ion chromatography (manufactured by Dionik) method. ₃ Converted to Na base number. (Note 2) Calculated based on the charging ratio and the number average molecular weight of the thermoplastic polyurethane resin, assuming that all tertiary hydroxyl groups are unreacted. (Note 3) Solubility measurement in organic solvents Evaluated in the state of cyclohexanone solution with non-volatile content of 20% ◎: Completely dissolved at 50℃ and room temperature (23℃), transparent and stable solution. 〇: Completely dissolved and transparent solution at 50℃, transparent jelly state at room temperature. Separated into solid matter. ×: Suspended state at 50℃, separated into cloudy opaque solution layer and solid layer at room temperature. (Note 4) Measurement of number average molecular weight: Molecular weight was measured in terms of polystyrene by gel permeation analysis. Measuring device (LC-08 type), detector (RI): Japan Analytical Industry Co., Ltd. Measuring column: Showa Denko Co., Ltd. Shodex
-dex) A-806, A-805, A-804, A-
803, A-802 (Note 5) Dispersibility of magnetic powder Thermoplastic polyurethane resin obtained in Examples 1 to 3 or Comparative Examples 1 to 5 150 parts Cyclohexanone 600 parts Methyl ethyl ketone 250 parts γ-Fe ₂ O ₃ Magnetic powder 300 parts The above mixture was milled in a ball mill for 20 hours. The resulting magnetic paint was coated on a polyethylene terephthalate base film with a thickness of 10 μm so that the thickness after drying was 10 μm. 40
The surface condition of the magnetic layer was observed under the following conditions: The evaluation criteria are listed below. ◎: Very good 〇: Excellent △: Average ×: Poor Example 4 1.0 mol of polytetrahydrofuran with a molecular weight of 1000 (hydroxyl value 112), DES (manufactured by Nippon Hydrazine Co., Ltd., 5-
sodium sulfobis β-hydroxyethyl isophthalate/ethylene glycol 35/65 weight ratio)
0.5 mol, dibutyltin dilaurate 0.2 parts, 2,4
-Tolylene diisocyanate/2,6-tolylene diisocyanate (80/20 mixture) NCO/OH=
A thermoplastic polyurethane resin was prepared in the same manner as in Example 1 at a molar ratio of 1.00/1.02. Example 5 1.0 mol of polycaprolactone with a molecular weight of 3000 (hydroxyl value 37.4) using 1,3,5-hydroxy-3-methylpentane as an initiator, 0.8 mol of DES, 0.2 part of dibutyltin dilaurate, 1,6-hexamethylene Diisocyanate NCO/OH molar ratio 1.00/
1.02, a thermoplastic polyurethane resin was prepared in the same manner as in Example 1. However, in both Examples 4 and 5, the isocyanate was reacted at a temperature of 35°C. _-SO3Na group number of thermoplastic polyurethane resins obtained in Examples 4 to 5, solubility in organic solvents,
The number average molecular weight and dispersibility of the magnetic powder were measured using the same methods as described above, and the results are shown in Table 2. Furthermore, Table 3 shows the measurement results of the heat and humidity resistance of the cured films obtained in Examples 1 to 5 and Comparative Examples 2 to 4 using polyisocyanate of the thermoplastic polyurethane resin as a crosslinking agent.

【table】

【table】

[Table] (Note 5) Moisture and heat resistance of cured film A solution consisting of 100 parts of a cyclohexanone solution with a non-volatile content of 20% and 5 parts of Burnock D-750 (low molecular weight polyisocyanate manufactured by Dainippon Ink & Chemicals) was applied onto release paper. and then at 80℃ for 5 minutes.
Physical properties of a film with a thickness of approximately 100μ obtained by drying at 120°C for 10 minutes and further drying at 70°C
The physical properties of the film were measured after two weeks at a relative humidity of 95%. Film properties: Autogra IM-100 Shimadzu Corporation
According to JIS K-6301 manufactured by Co., Ltd. From the results shown in Tables 1 and 2, it was confirmed that the thermoplastic polyurethane resins according to Examples 1 to 5 contributed to improving the dispersibility of the magnetic powder without impairing the solubility in organic solvents. Furthermore, from the results shown in Table 3, it was confirmed that the thermosetting polyurethane resin composition of the present invention has excellent moist heat resistance. <Abrasion resistance test of magnetic tape> Thermoplastic polyurethane resin obtained in Examples 1 to 5 or Comparative Examples 2 to 4 40 parts Vinyrite VAGH (manufactured by Union Carbide, USA,
Vinyl chloride. Vinyl acetate copolymer) 60〃 Cyclohexanone 300〃 Methyl ethyl ketone 300〃 γ-Fe ₂ O ₃ magnetic powder 350〃 Carbon black 12〃 Lubricant 5〃 The above mixture was kneaded in a ball mill for 24 hours, and then milled with Burnock D-750. (Manufactured by Dainippon Ink Chemical Co., Ltd., low molecular weight polyisocyanate) 20 parts were added and kneaded for an additional hour.
A magnetic recording tape was prepared by coating and drying the mixture onto a micron polyethylene terephthalate base film to a dry thickness of 10 microns, and cutting it to a predetermined width. Then, the abrasion resistance was measured. The measurement method was to rub the magnetic surface of each tape with a rotating disk and measure the amount of wear on the coating film. The results are shown in Figure 1. From FIG. 1, it can be seen that the magnetic tapes of Examples 1 to 5 using thermosetting polyurethane resin compositions consisting of thermoplastic polyurethane resin (A) and polyisocyanate (B) exhibit superiority in durability performance. confirmed.

[Brief explanation of the drawing]

Figure 1 shows the amount of wear ( It is a graph showing the relationship between mg) and time (minutes).

Claims (1)

[Scope of Claims] 1 (A) a thermoplastic polyurethane resin having -SO ₃ A thermosetting polyurethane resin composition comprising a low molecular weight polyisocyanate.