JPH0251441B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an amino group-containing liquid diene polymer, and more particularly to a method for producing an amino group-containing liquid diene polymer useful as a raw material for a polyurethane composition. Conventionally, polyurethane obtained from liquid diene polymers, such as liquid diene polymers with terminal hydroxyl groups, has superior water resistance and electrical properties compared to ordinary polyurethane, and these properties have been utilized to create a variety of products. It is widely used in various industrial fields. However, the cured polyurethane obtained from a liquid diene polymer having a hydroxyl group at the end and an organic polyisocyanate does not have sufficiently satisfactory physical properties such as mechanical strength and elongation. Therefore, it has been necessary to add reinforcing agents such as other polyols. However, the addition of reinforcing agents has the disadvantage that the originally excellent properties of liquid diene polymers such as water resistance, low temperature properties, and electrical properties are reduced. Further, the heat resistance is not sufficient at about 120 to 150°C, and the reaction curing speed is also not fast. These problems have limited the use of conventional polyurethanes made of liquid diene polymers in reaction injection molding (RIM) or reinforced reaction injection molding (R-RIM), which have been rapidly developed in recent years. The inventors of the present invention have conducted intensive research to develop polyurethane that solves the above-mentioned problems. As a result, by reacting a liquid diene polymer having an isocyanate group with a nitro compound having an active hydrogen group and then reducing it, a liquid diene polymer that satisfies the above objectives and can be used as a raw material for polyurethane can be efficiently produced. Based on this finding, the present invention was completed. That is, the present invention provides a liquid diene polymer having an isocyanate group and having a number average molecular weight of
300 to 25,000 with a nitro compound having an active hydrogen group selected from nitro alcohols, nitrophenols, and nitroamines, and then subjected to reduction treatment. The present invention provides a method for manufacturing a combination. Here, the liquid diene polymer having an isocyanate group is a liquid diene polymer having an isocyanate group in the molecule, particularly at the end of the molecule, and various polymers can be considered without particular limitation. Although this liquid diene polymer having an isocyanate group can be produced by various methods, it is usually obtained by reacting a liquid diene polymer having an active hydrogen group with an organic polyisocyanate. The liquid diene polymer having an active hydrogen group used in this case is a liquid diene polymer having an active hydrogen group such as a hydroxyl group, a carboxyl group, an amine group, an imino group, or a mercapto group in the molecule, especially at the end of the molecule. be. Examples of these liquid diene polymers include diene polymers and diene copolymers having a number average molecular weight of 300 to 25,000, preferably 500 to 10,000 and having 4 to 12 carbon atoms, and furthermore, these diene monomers and carbon atoms having 2 to 22 carbon atoms. There are copolymers with α-olefinic addition polymerizable monomers. It also includes those modified by adding unsaturated carboxylic acids such as maleic anhydride or derivatives thereof to these liquid diene polymers. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer, and the like. Among these liquid diene polymers, the viscosity is less than 500 poise (30℃) and the microstructure is 1,
A polymer or copolymer having 4-bonds of 50% or more is preferably used. On the other hand, various organic polyisocyanates can be used to react with the liquid diene polymer having active hydrogen groups, but this polyisocyanate is generally used to introduce isocyanate groups into the diene polymer. Since the molecular weight is relatively low, examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, liquid modified products of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and the like. In order to obtain a liquid diene polymer having an isocyanate group, an organic polyisocyanate may be reacted with the above-mentioned liquid diene polymer having an active hydrogen group, but there is no particular restriction on the proportion used. It may be determined as appropriate. However, usually the ratio of NCO groups to active hydrogen groups (NCO groups/active hydrogen groups) may be determined to be in the range of 2 to 10, preferably in the range of 2 to 5. In addition, various reaction conditions can be selected at this time, and it is possible to simply mix the two at room temperature, but generally the temperature is 40 to 100℃.
The reaction may be carried out at a temperature of about 2 to 6 hours. Next, the nitro compounds having an active hydrogen group used in the present invention include nitro alcohols, nitrophenols, and nitroamines, and specifically include nitrobenzyl alcohol, nitroethanol, nitropropanol, nitrobutanol, nitropentanol, Examples include nitrophenol, nitroaniline, nitroaminotoluene, nitropropylamine, nitrobutylamine, and the like. The production method of the present invention comprises two steps: a step of reacting the liquid diene polymer having an isocyanate group with a nitro compound having an active hydrogen group, and a step of further reducing after the reaction. In the first stage reaction, the liquid diene polymer having an isocyanate group and the nitro compound having an active hydrogen group are mixed in an appropriate ratio, usually an NCO/active hydrogen group (equivalent ratio) of 0.5 to 5, preferably 0.8～
The reaction temperature is 20 to 150°C, preferably 40 to 130°C, and the reaction time is 1 to 12 hours, preferably 1 to 8 hours. Further, during this reaction, p-quinone, BHT, hydroquinone, hydroquinone monomethyl ether, etc. can be added as a stabilizer, and di-n-butyltin dilaurate, stannath octoate, etc. can be added as a reaction accelerator, if necessary. The reaction product obtained in this way is a reaction product of active hydrogen groups and isocyanate groups,
It is a liquid diene polymer containing nitro groups. In the second stage reaction, the nitro group of the reaction product is reduced to an amino group. Various commonly used methods can be used for this reduction reaction. The main methods are methods using metals and acids such as stannous chloride and hydrochloric acid or iron and hydrochloric acid, catalytic reduction methods using Raney nickel or palladium and hydrogen, and metal hydrides such as lithium aluminum hydride or sodium borohydride. methods, and methods using other reducing agents (hydrosulfite, ferrous sulfate and aqueous ammonia, zinc and water, etc.). The amounts of substances, solvents, reaction conditions, etc. required for these reduction reactions vary depending on the method and cannot be unambiguously determined, but they can be carried out using procedures similar to those commonly used. Particularly preferred reduction methods include a method using equimolar or more of stannous chloride and concentrated hydrochloric acid using an alcohol or xylene as a solvent, a method using iron powder and concentrated hydrochloric acid using an alcohol or benzene as a solvent, and a method using Raney nickel using toluene as a solvent. Examples include a method of introducing hydrogen at high pressure in the presence of hydrogen, and a method of using lithium aluminum hydride in a nitrogen atmosphere using ethers as a solvent. As described above, according to the method of the present invention, the desired amino group-containing liquid diene polymer can be obtained efficiently with relatively simple operations. Moreover, since gelation does not occur during this manufacturing process, handling is easy. Furthermore, by reacting this amino group-containing liquid diene polymer with an organic polyisocyanate, a polyurethane composition having excellent mechanical strength, elongation, heat resistance, etc. can be obtained. In producing the above polyurethane composition, an organic polyisocyanate is added to the amino group-containing liquid diene polymer obtained by the method of the present invention, and part or all of it is reacted to form a urethane bond. or urea bond). In addition, at this time, short-chain or long-chain polyols, polyamines, etc. can be used in combination, if desired. These polyols and polyamines include 1,
4-butanediol, trimethylolpropane,
Ethylene glycol, 3 mole ethylene oxide adduct of bisphenol A, ethylenediamine, triethylenediamine, N,N-bis(2-hydroxypropyl)aniline, polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene triol, polyoxypropylene triol and so on. Examples of the organic polyisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, liquid modified product of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate, chlorophenylene diisocyanate, naphthalene-1,
5-diisocyanate, xylylene-2,2'-diisocyanate, isopropylbenzene-2,4
-diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, tris-4-phenyl isocyanate thiophosphate, 3,3',4,4'-diphenylmethane tetraisocyanate, polypropylene glycol or triol and tolylene diisocyanate Examples include an addition reaction product, an addition reaction product of 1 mol of trimethylolpropane and 3 mol of tolylene diisocyanate, and a prepolymer of a diene polymer containing active hydrogen groups and polyisocyanate. The amount of this organic polyisocyanate is
The equivalent ratio (NCO group/active hydrogen group) between the NCO group and the total active hydrogen group of the liquid diene polymer containing an amino group or a polyol or polyamine when used together is in the range of 0.5 to 2.0, preferably 0.6 to 1.5. Just set it so that it falls within the range. This range varies depending on the desired use of the polyurethane composition, and may be set to 0.95 or more in order to obtain a completely cured product, and approximately 0.6 to 0.9 in applications where tackiness, adhesion, etc. are required. Furthermore, in order to produce this polyurethane composition, a urethane catalyst such as di-n-butyltin dilaurate, stannath octoate, triethylenediamine, diethylenediamine, triethylamine, naphthenate metal salt, octylate metal salt, etc. is used as a curing reaction accelerator. It can also be used. In addition, plasticizers such as dioctyl phthalate and dibutyl phthalate; modifiers such as process oils, solvents, bituminous substances, and adhesive resins; antioxidants, anti-aging agents, colorants, and blowing agents are added depending on the purpose of use. It can also be added as appropriate. The polyurethane composition obtained in this way becomes a cured product with excellent mechanical strength and elongation as described above, and has a high curing speed, so it can be suitably used for RIM or R-RIM. . This polyurethane composition can be applied not only to the conventionally used fields of polyester polyurethane and liquid diene polyurethane, but also to completely new fields, and can be used to produce general molded products, injection molded products, etc. using various molding methods. molded products,
It can be foam, fiber, synthetic leather, etc. Also, paints, adhesives, sealants, waterproofing agents,
It can also be used in various fields such as resin mortar. Therefore, the amino group-containing liquid diene polymer obtained by the method of the present invention can be widely used as a curing agent for modifying epoxy resins, as well as the above-mentioned polyurethane compositions. Next, the present invention will be explained in more detail with reference to Examples. Reference example [Production of isocyanate group-containing liquid polybutadiene] Hydrogen group-containing liquid polybutadiene (number average molecular weight
3000, hydroxyl content 0.82meq/g, viscosity 50 poise/
30℃, microstructure trans-1,4:60%, cis-
100 parts by weight of vinyl 1,4:20%, vinyl-1,2:20%) and 16.8 parts by weight of tolylene diisocyanate (NCO/OH=2.35) were charged into a reactor, and the mixture was heated at 60°C for 6 hours with stirring under a nitrogen atmosphere. carry out the reaction,
A liquid polybutadiene having an isocyanate group content of 4% by weight was obtained. Example 1 210 parts by weight of liquid polybutadiene having isocyanate groups obtained in the above reference example, 27.6 parts by weight of m-nitroaniline (NCO/NH ₂ = 1.0), di-n-
Butyltin dilaurate 0.007 parts by weight and p-
0.21 parts by weight of quinone was charged into a reactor, and the reaction was carried out at a reaction temperature of 120° C. and a reaction time of 5 hours while stirring under a nitrogen atmosphere to obtain a viscous nitro group-containing liquid polybutadiene. As a result of measuring the obtained reaction product by infrared absorption spectrum, almost no absorption of isocyanate was observed. Next, 200 parts by weight of the obtained nitro group-containing liquid polybutadiene, 1000 parts by weight of isopropanol, and 100 parts by weight of toluene were charged into a reactor, and a solution of 250 parts by weight of stannous chloride in 300 parts by weight of concentrated hydrochloric acid was added under cooling. was added while stirring vigorously. Thereafter, the temperature inside the reactor was set to 100° C., and the reaction was continued for another 2 hours with stirring. After cooling, 1000 parts by weight of water was added and washed, and the solvent was distilled off using a rotary evaporator to obtain amino group-containing liquid polybutadiene. The amine value of the obtained product was 52.1mgKOH/
g (measured by potentiometric titration using a 1/10N perchloric acid solution), and the viscosity is 230 poise/30°C.
It was hot. Example 2 In place of m-nitroaniline in Example 1, 27.8 parts by weight of p-nitrophenol (NCO/OH
= 1.0), the reaction temperature was 120°C, and the reaction time was 4 hours, but the reaction was carried out in the same manner as in Example 1 to obtain a yellowish brown viscous liquid polybutadiene having nitro groups. Furthermore, a reduction reaction was carried out in the same manner as in Example 1 to obtain polybutadiene having amino groups. The obtained product had an amine value of 52.0 mg·KOH/g (measured in the same manner as in Example 1) and a viscosity of 244 poise/30°C. Example 3 210 parts by weight of liquid polybutadiene having isocyanate groups obtained in the above reference example, 3-nitro-
22 parts by weight of 1-propanol (NCO/OH=0.95),
0.014 parts by weight of di-n-butyltin dilaurate and 0.21 parts by weight of p-quinone were charged into a reactor, and the reaction was carried out at a reaction temperature of 120°C for 2 hours with stirring under a nitrogen atmosphere, resulting in a yellowish brown viscous nitro group. A liquid polybutadiene containing liquid was obtained. Next, 200 parts by weight of the obtained nitro group-containing liquid polybutadiene, 800 parts by weight of isopropanol, and 800 parts by weight of benzene were charged into a reactor, and 100 parts by weight of iron powder moistened with 20 parts by weight of concentrated hydrochloric acid was added.
Next, 100 parts by weight of concentrated hydrochloric acid was added, and the mixture was reacted for 4 hours under refluxing benzene. After cooling, 3000 parts by weight of water was added and the benzene phase was taken out. After that, the obtained benzene phase was washed with water, and then benzene was distilled off using a rotary evaporator to obtain a yellowish brown viscous polybutadiene having amino groups. The amine value of this product was 50.5 mg·KOH/g (measured in the same manner as in Example 1), and the viscosity was 210 poise/30°C. Example 4 210 parts by weight of liquid polybutadiene having isocyanate groups obtained in the above reference example, 32 parts by weight of p-nitrobenzyl alcohol (NCO/OH=0.95),
0.014 parts by weight of di-n-butyltin dilaurate and 0.4 parts by weight of p-quinone were charged into a reactor, and the reaction was carried out at a reaction temperature of 130°C and a reaction time of 3 hours with stirring under a nitrogen atmosphere. A liquid polybutadiene having nitro groups was obtained. Next, 200 parts by weight of the obtained liquid polybutadiene having a nitro group was dissolved in 100 parts by weight of toluene, and the solution was charged into a high-pressure reactor together with 5 g of Raney nickel.
Hydrogen gas pressure was increased by introducing 130Kg/cm ² of hydrogen gas at 25℃.
The reaction was carried out at 120° C. for 6 hours while maintaining 130 Kg/cm ² . After the reaction, the mixture was cooled and filtered through the catalyst, and then the solvent was removed using a rotary evaporator to obtain liquid polybutadiene having amino groups. The obtained product had an amine value of 51 mg·KOH/g (measured in the same manner as in Example 1) and a viscosity of 250 poise/30°C. Application Examples 1 to 4 and Comparative Examples A liquid modified product of 4,4'-diphenylmethane diisocyanate (containing isocyanate groups) was added to the polybutadiene having an amino group obtained in Examples 1 to 4 or the liquid polybutadiene having a hydroxyl group used in the reference example. Amount: 28.3% by weight) of NCO/ _NH2 or
The amount and di-n that make NCO/OH (equivalence ratio) = 1.05
-0.06 parts by weight of butyltin dilaurate was stirred and mixed at 23°C and poured into a 2 x 150 x 300 mm sheet mold. Then, after heating and pressure curing at 120℃ for 1 hour, it was cured at 70℃.
After curing for 12 hours, a cured sheet with a thickness of 2 mm was obtained. Table 1 shows the results of measuring the physical properties of each cured sheet. In addition, the same 4,
The same amount of 4'-diphenylmethane diisocyanate liquid modified product as above was added and the reactivity was measured without adding a catalyst (di-n-butyltin dilaurate). The results are shown in FIG. The reaction was carried out at 23°C, and the reaction rate was calculated from the attenuation rate of isocyanate group absorption at 2260 cm ^-1 from the infrared absorption spectrum. 【table】

[Brief explanation of the drawing]

FIG. 1 is a graph showing the reactivity of a liquid polybutadiene having an amino group obtained by the method of the present invention or a liquid polybutadiene having a hydroxyl group which is a raw material compound. In the figure, A shows the reactivity of the liquid polybutadiene having a hydroxyl group used in the reference example, and B and C are graphs showing the reactivity of the liquid polybutadiene having an amino group obtained in Examples 1 and 4, respectively.

Claims (1)

[Scope of Claims] 1. A liquid diene polymer having an isocyanate group and having a number average molecular weight of 300 to 25,000, containing an active hydrogen group selected from nitroalcohols, nitrophenols, and nitroamines. 1. A method for producing an amino group-containing liquid diene polymer, which comprises reacting a nitro compound and then subjecting it to a reduction treatment. 2. The manufacturing method according to claim 1, wherein the liquid diene polymer having an isocyanate group is obtained by reacting a liquid diene polymer having an active hydrogen group with an organic polyisocyanate.