JPS60149623A - Production of polyurethane elastomer molding - Google Patents

Abstract

PURPOSE:To produce the titled molding excellent in elastic and physical properties, chemical resistance, etc., by molding a polyurethane elastomer formed by reacting an isocyanate group-terminated intermediate polymer with an amino compound and heat-treating the molding. CONSTITUTION:An isocyanato group-terminated intermediate polymer is produced by reacting a polymer diol (e.g., polyoxytetramethylene glycol) having a ratio of a weight-average MW to a number-average MW<=1.8 with an excess molar amount of an organic diisocyanate (e.g., p-phenylene diisocyanate). This intermediate polymer is reacted with a polyamino compound (e.g., propylenediamine) and a monoamino compound (e.g., dimethylamine) to form a polyurethane elastomer. This elastomer is molded and then heat-treated. This polyurethane elastomer shows very good moldability and its MW can be increased extremely efficiently. Therefore, it can be given performances including excellent elastic properties, chemical resistance, physical properties, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyurethane elastomer molded article, and its purpose is to improve the elastic properties, chemical resistance, and strength of the polyurethane elastomer molded article. is to provide.

In general, polyurethane elastomers are produced by reacting polyhydroxy compounds such as polyesters and polyethers having hydroxyl groups at their terminals with organic diisocyanates of 1/l/@ of a supernatant to form linear polyurethane intermediate polymers having substantially incyanate groups at both terminals. After producing a polymer and reacting the intermediate polymer with a diamino compound containing active hydrogen that easily reacts with isocyanate groups in an inert organic solvent, molding 1
Then, by removing the solvent, it is molded into a polyurethane elastomer molded product such as a film or thread having elastic properties. In addition to elastic properties, other important properties of polyurethane elastomers include physical properties such as chemical resistance, 1 strength, and r# abrasion resistance, as well as light resistance. In particular, it is recommended to use a polyurethane elastomer having a high molecular weight in order to provide highly desirable properties such as elastic properties, chemical resistance, and physical properties. Conventionally, as a method for obtaining a high molecular weight polyurethane elastomer, Japanese Patent Publication No. 29-5541, Japanese Patent Publication No. 40-3717, and Japanese Patent Publication No. 41-3715 have been disclosed.

Special Publication No. 41-4468, Special Publication No. 47-14143
As described in the above publications, various methods are known that utilize the reaction between incyanate and active hydrogen at the end of the polymer. However, it has the drawbacks that it is difficult to control the reaction and that it is difficult to obtain a polyurethane elastomer with a desired high molecular weight due to the formation of a three-dimensional structure. Elastic properties of films, threads, etc., chemical resistance,
A method that satisfies all physical properties has not yet been found.

The inventors of the present invention have conducted intensive research to solve the above-mentioned problems and obtain a molded article of high molecular weight polyurethane elastomer.

We have arrived at the present invention. That is, the present invention uses a polymer diol having a ratio of 1 weight average molecular weight to a number average molecular weight of 1.8 or less, an excess 70% organic diisocyanate, and optionally a small amount of water, low molecular weight glyco-μ, etc. This is a method for producing a polyurethane elastomer molded article, which is characterized by producing an intermediate polymer having an isocyanate group, and then heat-treating the intermediate polymer, a polyfunctional amino compound, and a monofunctional amino compound.

According to the present invention, the moldability is good and the molecular weight can be increased very efficiently, and along with this, excellent performances such as elastic properties, chemical resistance, and physical properties can be imparted.

The polymer diol used in the production of the intermediate polymer in the present invention includes polyoxyethylene resin: + +
A/, polyether diols such as polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, polyoxypropylenetetramethylene glycol, adipic acid, sepacic acid, maleic acid, itaconic acid, azelaic acid, malonic acid, etc. one or more dibasic acids and ethylene glycol.

1.2-7"ropylene glycol, 1.3-7"ropylene glycol, 2,2-dimethyl-1,3-propanedio-/l/, 114-butanediol, 2,3-butanediol, hexa Polyester di-μ obtained from one or Ii or two or more glycols such as methylene glycol, diethylene glycol, 1,10-decanediol, 1,3-cyclohexane dimetatool, 1,4-cyclohexane dimetatool, etc. , polylactone diols such as polyε-cablockton, polyvalerolactone, polyesterfuramide diol-/I/, polyether-
Examples include ester diol and polycarbonate diol.

The molecular weight of the polymer diol is usually about 600 to 7,000, preferably 1,000 to 5,000. The polymer diol in the present invention needs to have a molecular weight distribution, that is, a ratio of weight average molecular weight to number average molecular weight of 1.8 or less, preferably 1.5 or less. When the ratio of weight average molecular weight to number average molecular weight exceeds 1.8, the resulting polyurethane elastomer is difficult to increase in molecular weight even by heat treatment, and physical properties such as elastic properties, chemical resistance, strength, and modulus are also improved. It becomes difficult to bud. When the ratio is 1.8 or less, particularly preferably 1.5 or less, the polyurethane elastomer molded article can be efficiently increased in molecular weight by heat treatment and its elastic properties can be improved. Incidentally, the weight average molecular weight and number average molecular weight of the polymer diol referred to in the present invention are values determined from a known gel permeation chromatograph.

As the organic diisocyanate used in the present invention, all aliphatic, alicyclic and aromatic diisocyanates which dissolve or are liquid under the reaction conditions can be used. For example, p-phenylene diisocyanate, bis(
4-incyanatophenyl)methane, bis(3-methy1v-4-isocyanatophenyl)methane, bis(4-
Examples include isocyanatocyclohexy/L/)methane, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, k-xamethylene diisocyanate, etc. The maximum molar ratio with the organic diisocyanate is 1:1.5 in consideration of desirable elastic properties and physical properties.
~1: 2.5, but is not particularly limited.

In addition, polyfunctional amino compounds include ethylenediamine, propylenediamine, trimethylenediamine, hexamethylenediamine, hydrazine, carbodihydrazide,
Adipic acid dihydrazide, sepacic acid dihydrazide,
N, N'bis(γ-aminopropy/I/) -N,,N
- Difunctional aliphatic diamines such as dimethylethylene diamine can be exemplified.

As the monofunctional amino compound used at the same time, for example, 1
Functional secondary amines include dimethylamine, methylethylamine, diethylamine, methyl-n-propylamine, methyl-isopropylamine, diisopropylamine, meth A/-H-butylamine, methyl-isobutylamine, methyl-isoamylamine, etc. can be mentioned.

The proportion of monofunctional amine compounds is 1 to 1 for all amino compounds.
The amount is 30 moles/l/%, preferably 5 to 20 moles. When the horizontal axis is the ratio of the weight average molecular weight to the number average molecular weight of the polymer diol, and the linear axis is the monofunctional amino compound/total amino compound (mo/l'%) during the chain extension reaction, Figure 1 ■ It is necessary that the range is within the range indicated by , and is a particularly preferred range. In addition,
The total amount of the polyfunctional amino compound and the monofunctional amino compound used is at least equimolar to the number of moles of isocyanate groups in the intermediate polymer, preferably in excess molar amount. Even if the resulting polyurethane elastomer is heat-treated outside the scope of the present invention, it has disadvantages in that it has a high molecular weight, has poor elastic properties, and is also poor in physical properties such as chemical resistance and strength and elongation.

However, in the scope of the present invention, it is possible to efficiently increase the molecular weight of a polyurethane elastomer, and it is also possible to significantly improve physical properties such as elastic properties, chemical resistance, strength, and modulus.

The polyurethane elastomer solution of the present invention may optionally further contain gas anti-yellowing agents, stabilizers such as ultraviolet absorbers, barium sulfate, aluminum silicate, magnesium silicate, calcium silicate, ms fine particles such as zinc oxide, calcium stearate, Magnesium stearate, polytetrafluoroethylene.

Anti-tack agents such as organopolysiloxane, antifungal agents, and other compounding agents can be appropriately blended.

The solution thus obtained can be formed into threads, films, etc. by conventional methods, or used as a coating agent, etc., but it is particularly effective when applied to threads and films. After molding, the solvent is usually removed and then heat treated to increase the molecular weight of the polyurethane elastomer and improve its physical properties. In this way, a high molecular weight polyurethane elastomer molded article with excellent moldability and excellent physical properties after molding can be obtained. Note that the intrinsic viscosity of the polymer in the high molecular weight polyurethane elastomer and ldN,N dimethylacegamide as used in the present invention is 1.5 or more, preferably 1.8 to 2.5.

The intrinsic viscosity is given by the formula Jn(η/ηo)/C.

η is the viscosity of a dilute solution of the polymer at 30°C,
ηO is the viscosity of the solvent in the same equipment and at the same temperature;
．． 3, which is the number of grams of polymer contained in solution 10C1+/.

The heat treatment temperature carried out in the present invention is usually 40 to 15
The temperature is 0°C, preferably 60 to 100°C, and the time is usually within 24 hours, although it is not particularly limited as it varies depending on the processing equipment. In particular, the time can be shortened by heating under reduced pressure, etc., but about 2 to 24 hours is preferable. Unlike conventional actively crosslinked polyurethane elastomers, the polyurethane elastomer molded product obtained by the present invention is easy to handle despite its very high molecular weight, and has excellent elastic properties and durability. It has medicinal properties and physical properties. Although the effects of the present invention are surprising as described above, the reason for these effects is not necessarily clear.

The present invention will be explained in more detail with reference to Examples, in which the properties of the films and threads in the Examples were measured by the methods shown below. In addition, the parts in Examples are based on weight. Strength, elongation, and modulus 1 elastic recovery were measured using a tensile tester.

(1) Strength Cf/d) is the cutting strength when elongated at a speed of 1000%/min.

(2) Elongation (%) is the cutting elongation when elongated at a speed of 1000%/min.

(3) Modulus (f) is the elongation stress when elongated to 300 inches at a speed of VilooO%/min.

(4) Elastic recovery rate (%) is 30 at a speed of 1000%/min
This is the (1-(unrecovered rate))xloo% value after the tension was removed after 0-inch stretching and left for 1 minute.

(5) Chemical resistance is the volume ratio of the film before and after immersion in chloroform (room temperature).

(6) Hot water shrinkage rate (ch) is the difference in distance between two points before and after hot water treatment.

(7) Repeated insertion unrecovery rate (%) is 60 cycles/I/
This is the unrecovery rate during repeated elongation (10,000 times) from 100 to 200% at a speed of /min.

In addition, in the following examples, the following abbreviations are used.

Q Polyoxytetramethylene glycol abbreviation PTMG O bis(4-incyanate phenyl) methane DI O propylene diamine PDA O diethylamine DEA O diisopropylamine DPA ON, N dimethylformamide DMFON, N dimethyl acetamide DMAC Parts and parts are by weight unless otherwise specified.

Example 1 PTMG with molecular weight 2.000 (Mw/Mn ratio 2.0)
100 parts of MDI, 219 parts of MDI, and 656 parts of dry DMF were charged and heated at 40° C. for 1 hour to produce an intermediate polymer having terminal inanate groups, and then cooled to room temperature.

Separately, 1900 parts of dry DMF, 4.3 parts of DPA and 2 parts of PDA
178 parts of the above intermediate polymer solution was added to the solution to which 4.8 parts were added.
0 parts was added under vigorous stirring to carry out a chain extension reaction, and then a stabilizer solution was added to obtain a polyurethane elastomer solution.

PTMs shown in Table 1 (1-2, 1-4) in a similar manner
Polyurethane polymer solutions were obtained by polymerization using G.

The resulting viscous solution of polyurethane elastomer had a solids content of over 32 and a viscosity of 2500-2800 poise at 30°C.

Pour each obtained polymer solution onto a glass plate.

A uniform film with a thickness of 50 .mu.m was obtained by drying at 60.degree. C. overnight, and then heat treated at 100.degree. C. for 8 hours. The elastic recovery properties, chemical resistance, and polymer viscosity of the film were measured. The results are shown in Table 2.

Example 2 PTMG with molecular weight 1800 (Mw/Mn ratio 2.6)
1000 copies, MDI 215 copies, dry! ! #DMAC85
4 parts were charged and heated at 40° C. for 1 hour to produce an intermediate having terminal incyanate groups, and then cooled to room temperature. Separately, 420 parts of dry DMACl, 15.9 parts of EDA and DE
1,650 parts of the above intermediate polymer solution was added to a solution containing 6 parts of each of Ao and 6 parts of Ao under vigorous stirring to carry out an elongation reaction. A stabilizer solution was then added to obtain a polyurethane elastomer solution. In the same way, Table 1 (2-2゜2-3.2-4
．． Polymerization was performed using PTMG shown in 2-5). The resulting polyurethane elastomer had a viscosity of 2,000 to 2,400 poise. A film was prepared from the obtained polymer solution in the same manner as in Example 1, and after heat treatment (at 80° C. for 24 hours), the physical properties were measured. The results are shown in Table 2.

Table 1 (1) Number average molecular weight determined from OH value (2) Weight average molecular weight (Mw) determined from group permeation chromatography and number average molecular it (Mn) Table 2 (1) 0°C (2) Polymer solid viscosity was measured at 30°C at a concentration of 0.3f/10011t in N,N dimethylacegamide Experiment No. 1-3.1-4.2-3.2, which is the method of the present invention
-4.2-5 It was a polyurethane elastomer film with excellent elastic properties and chemical resistance, and a high molecular weight. Further, Experiment No. 1-3.2-3 is useful as a coating agent because of its improved chemical resistance.

After defoaming the polymer solution obtained in Example 1.2.

Dry spinning was carried out using a spinneret with five direct (10,15-) orifices, and winding was carried out at a speed of 480F7!/min.
A filament of 0 denier was obtained.

Table 3 (1) Elongation stress at 300% elongation (2) 9°C, 10,000 repeated elongation Example 4 Experiment number 1-1.1-4.2 obtained from Example 1.2
Table 4 shows changes in the intrinsic viscosity (dJ/f) of the polymer when the polyurethane elastomer of -3.2-5 was heat treated.

Table 4 Experiment No. 1-4.2-3.2-5, which is the method of the present invention, was surprisingly a polyurethane elastomer that was very easy to increase in molecular weight.

[Brief explanation of the drawing]

Figure 1 shows the weight-average molecular weight (bias)/number-average compound (MoJ') of polymer diols in the production of polyurethane polymers.
v%), the region indicated by ■ is the present invention, and the region indicated by ■ is a particularly preferable range. Patent applicant: Toyobo Co., Ltd., Figure, V rating average 1 (le) ratio procedural amendment (voluntary). September 11, 1980 Director General of the Patent Office Mr. Manabu Shiga IkuL Case Indication 1982 Patent Application No. 5395 2 Title of Invention Method for Manufacturing Polyurethane Elastic Molded Articles 8 Relationship with the Amendment Person Case Patent Application 288 Dojihama 2-chome, Kita-ku, Osaka "
Corrected to "wear resistance." (3) Delete "Molding" in the 14th line of page 2 of specification i1. (4) Delete “Chemical resistance” in the 18th line of page *kz in the details. (6) Insert "chemical resistance," between "furthermore" and "light resistance j" on page 2, line 19 of the specification. (6) “It can be done.” on page 5, line 12 of the specification.
is corrected to "Although polyoxytetramethylene glycol is particularly preferred in the present invention." (7) "And so on" on page 6, line 19 of the specification is corrected to "and mixtures thereof, etc." (8) Change “such as” in lines 10 to 11 of page 7 of the specification to “
and mixtures thereof, etc.”. (9) "And so on" on page 7, line 19 of the specification is corrected to "and mixtures thereof, etc." 00) Insert "antioxidant," between "further" and "gas yellowing inhibitor" on the last line of page 8 of the specification. Attachment Claim L A polymer diol having a ratio of weight average molecular weight to number average molecular weight of 1.8 or less is reacted with an excess molar amount of organic diisocyanate to produce an intermediate polymer having terminal isocyanate groups, and then the intermediate polymer having terminal isocyanate groups is produced. A method for producing a pyriurethane elastomer molded article, which comprises molding a polyurethane elastomer obtained by reacting an intermediate polymer with a polyfunctional amine compound and a monofunctional 7-mino compound, and then heat-treating the product. ! Is the molar ratio of the polyfunctional amino compound and monofunctional amino compound 7Q:91? The method for producing a polyurethane elastomer molded article according to claim 1, wherein the ratio is 30:1. 1. The method for producing a polyurethane elastic molded product according to claim 1, wherein the polyurethane elastic molded product is a thread or a film.

Claims (1)

[Claims] 1. Producing an intermediate polymer having terminal isocyanate groups by reacting a polymer diol with a ratio of weight average molecular weight to number average molecular weight of 1.8 or less with an excess molar amount of IE' incyanate. 1. A method for producing a polyurethane elastomer molded article, which comprises: 1) molding a polyurethane elastomer obtained by reacting the intermediate polymer with a polyfunctional amino compound and a monofunctional amino compound, and then heat-treating the same. 2. The method for producing a polyurethane elastomer molded article according to claim 1, wherein the molar ratio of the polyfunctional amino compound to the monofunctional amino compound is 70:99 to 30:1. 3. The method for producing a polyurethane elastomer molded article according to claim 1, wherein the polyurethane elastomer molded article is a thread or a film.