JPH034015B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a highly rigid diacetylene group-containing polyurethane molded body useful as precision mechanical parts such as gears and cams.

[Prior art]

Certain diacetylene compounds can be heated in their crystalline state,
It is well known that polymerization is caused by high-energy rays such as gamma rays or ultraviolet rays (topochemical polymerization).

However, although there are some reports on polyurethanes containing diacetylene groups, there are few research examples (Makromo.Chem., 134 , 219-229
(1970), Arm.Khim.Zh., 23(11) , 1004−1009
(1970), USP No. 3709860, etc.). Further, no attempt has been made to obtain a highly rigid molded article by molding a diacetylene group-containing polyurethane.

The present inventors focused on the characteristics of the diacetylene structure, especially its high reactivity, and as a result of intensive research in order to take advantage of the high reactivity, the present inventors developed polyurethane containing a diacetylene structure in a solid state below its melting temperature. By molding under high pressure conditions, it was possible to obtain a highly rigid molded article, and the present invention was achieved.

That is, the present invention relates to a method for producing a highly rigid molded article, which is characterized by molding diacetylene group-containing polyurethane in a solid state under high pressure conditions.

The diacetylene group-containing polyurethane in the present invention is a polymer having a unit represented by the following general formula (1) and having a molecular weight of 1×10 ³ to 1×10 ⁵ .

(In the formula, R is a residue of a diisocyanate having 2 to 20 carbon atoms excluding NCO.) The diacetylene group-containing polyurethane in the present invention is prepared by combining an organic diisocyanate and a diacetylene group-containing diol in accordance with a conventional method. It can be synthesized by an addition reaction with 2,4-hexadiyne-1,6-diol.

Examples of organic diisocyanates include hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), 4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2, 4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), metaxylylene diisocyanate (XDI), 1,5-
Naphthalene diisocyanate, 4,4'-cyclohexylmethane diisocyanate (hydrogenated MDI)
etc. and mixtures thereof can be used. On the other hand, the comonomer 2,4-hexadiyne-
1,6-diol can be synthesized by oxidative coupling of propargyl alcohol in a conventional manner.

Polyurethane can be synthesized by the polyaddition reaction of diisocyanate and diol by a conventional method for producing polyurethane as described in books such as Plastic Materials Course [2] Polyurethane Resin (Nikkan Kogyo Shimbun).

The molecular weight of the diacetylene group-containing polyurethane is not particularly limited, but is generally between 1×10 ³ and 1×10 ⁵ . Further, although there is no limit to the shape of the diacetylene group-containing polyurethane, a powdery shape is preferably used.

The method for producing a highly rigid molded body of diacetylene group-containing polyurethane of the present invention is characterized in that the diacetylene group-containing polyurethane produced by the above method is molded in a solid state under high pressure.

As a method for molding under high pressure, for example, a pressurization method such as a hydrostatic pressurization method can be used. The pressurizing pressure only needs to be 500 atmospheres or more, and there is no particular upper limit. Preferably it is 1000 atm to 8000 atm. Furthermore, when pressurizing, molding is possible by applying pressure under atmospheric pressure, but in order to obtain a molded product without voids, the air in the pressurized container and sample voids must be evacuated during pressurization, and the air must be reduced or vacuumed. It is preferable to form the product into a state and press-mold it.

The temperature during pressure molding is not particularly limited as long as it is below the melting temperature of the diacetylene group-containing polyurethane. Preferably, the temperature range is from room temperature (20°C) to 200°C, more preferably from 50°C to 150°C.
is within the range of The reason for this is that diacetylene group-containing polyurethane undergoes an exothermic reaction at about 160°C to about 200°C, and therefore needs to be molded at a temperature below that temperature.

The diacetylene group-containing polyurethane high-rigidity molded article of the present invention thus obtained is an extremely high-rigidity molded article having a compressive elastic modulus of 3 GPa or more, particularly 6 GPa or more, and has a high density and It is a molded product with excellent properties and high hardness.

The molded product obtained by implementing the present invention has excellent physical properties as described above, and can be machined into any shape by cutting or cutting, so it can be used for precision mechanical parts such as gears and cams. It is useful as a material for parts that require advanced physical properties.

Furthermore, when this diacetylene group-containing polyurethane is molded under high pressure, it is also possible to add inorganic or organic fillers, pigments, ultraviolet absorbers, stabilizers, etc. to the molding process.

Next, the present invention will be illustrated in more detail with reference to Examples. In the text, all parts are expressed in parts by weight. Examples are:
It is not intended to limit the scope of the invention.

Reference Example 1 Production of diacetylene group-containing polyurethane In a 4-necked flask with a capacity of 1 equipped with a stirring device, a dropping funnel, a nitrogen introduction tube, and a thermometer, 2,4-hexadiyne-1,6-diol 33 was added under a nitrogen stream.
(0.3 mol) was dissolved in 300 parts of dry N,N-dimethylformamide, and 0.3 part of di-n-butyltin dilaurate and 0.5 part of triethylamine were added as urethanation catalysts.

Then hexamethylene diisocyanate 50.5
(0.3 mol) into the flask under stirring,
The reaction was allowed to proceed for 1 hour. Then, it is heated by external heating.
The reaction was carried out at 60°C for 3 hours.

After the reaction was completed, the reaction solution was poured into 3000 parts of methanol with vigorous stirring to reprecipitate the diacetylene group-containing polyurethane.

The obtained powdered polyurethane is filtered and further
It was washed with 1000 parts of methanol and dried under reduced pressure for about 100 hours.

The yield of product was 83 parts. this product
Analysis by IR spectrum and NMR spectrum revealed that the target poly(oxycarbonyliminohexamethyleneiminocarbonyloxy2,4-hexadiyne) (hereinafter referred to as Poly(HMDI/2,4-HD))
) was confirmed. Also, GPG
As a result of molecular weight measurement using (gel permeation chromatography), the number average molecular weight was 3.6×10 ⁴
(polystyrene equivalent).

Using the same method, the type of diisocyanate was changed, and diacetylene group-containing polyurethane Poly (IPDI/2,4-
HD), hydrogenated MDI to Poly(hydrogenated MDI/2,4-
HD) Poly from MDI (MDI/2,4HD), Poly from TDI (TDI/2,4-HD), Poly from XDI
(XDI/2,4-HD) was produced.

Reference Example 2 In place of 2,4-hexadiyn-1,6-diol in Reference Example 1, 1,6-hexanediol was used to prepare a polyurethane containing no acetylene group [poly(oxycarbonylimihexamethyleneiminocarbonyloxyhexane)]. Methylene) (Poly
(HMDI/1,6-HDO)] was produced.

Example 1 0.7 parts of the diacetylene group-containing polyurethane (Poly(HMDI/2,4-HD)) produced in Reference Example 1 was packed into the cylinder of the molding machine shown in Figure 1, and the air inside was pumped out using a vacuum pump. Exhausted.

The molding machine was placed on a hydraulic press that had been preheated to 130°C, and the molding machine was preheated for 5 minutes. Subsequently, pressure molding was carried out at a pressure of 7960 Kg/cm ² for a time of 10 minutes. The obtained molded body was in the shape of a dark red disk with a thickness of about 2 mm and a major axis of 20 mm.

The obtained molded body is 14 mm in height, 13 mm in width, and 2 mm in thickness.
Cut out a rectangular parallelepiped, use it as a test piece, and test at a test speed of 0.5
A compression test was conducted using an Autograph DSS-500 model (manufactured by Shimadzu Corporation) under conditions of mm/min. The compressive elastic modulus was 3.9 GPa and the compressive strength was 98 MPa.

Comparative Example 1 Polyurethane (Poly(HMDI/1,6-HDO) containing no acetylene group produced in Reference Example 2)
was molded under the same conditions as in Example 1, and the resulting molded product was subjected to a compression test. The obtained compact had a compressive modulus of elasticity of 1.5 GPa and a strength of 29 MPa, which was a very weak compact.

Example 2 A similar molded article was obtained by changing the molding conditions of Example 1 from 10 minutes to 1 hour, and a compression test was conducted. The compressive elastic modulus of the compact was 3.9 GPa and the compressive strength was 88 MPa.

Example 3 The molding conditions of Example 1 were changed from 10 minutes to 4 hours. Height from the obtained molded body
A test piece of 13 mm, width 10 mm, and thickness 1.8 mm was cut out and subjected to a compression test. The compression modulus of the obtained compact is
The compressive strength was 6.1 GPa and 99 MPa.

Example 4 Poly (MDI/2,4-HD) was used instead of Poly (HMDI/2,4-HD) in Example 1 and molded at a pressure of 7960 Kg/cm ² for 2 hours. A similar molded body was obtained. A compression test of the obtained molded body revealed that the compression modulus was 4.8GPa,
The compressive strength was 120 MPa.

Examples 5 and 6 Poly (IPDI/2,4-HD) and Poly (hydrogenated) were used instead of Poly (HMDI/2,4-HD) in Example 1.
When molding was performed using MDI/2,4-HD), a similar molded product was obtained.

Example 7 The Poly (HMDI/2,4-HD) of Example 1 was molded using a press mold, preheated at 130°C for 5 minutes, and the pressure was 4590°C.
Pressure was applied for 10 minutes at Kg/cm ² to obtain a molded product having a thickness of 4 mm, a width of 12.7 mm, and a length of 60 mm. This molded body was tested at a test speed of 1
When a bending test was performed at mm/min, the bending elastic modulus was
It had a bending strength of 3.3 GPa and a bending strength of 0.99 GPa.

[Brief explanation of the drawing]

FIG. 1 is a half-cutaway sectional view of the molding device. In the figure, 1 is a push rod, 2 is a presser metal fitting, 3 is an outer cylinder, 4
1 is an inner cylinder, 5 is a base, 6 is an air discharge pipe, 7 is a receiving rod, 8 is an O-ring holder, 9 is a bell plate, 10 is above the O-ring, 11 is below the O-ring, and 12 is molded resin powder.

Claims (1)

[Scope of Claims] 1 A diacetylene group-containing polyurethane having a unit represented by the following general formula (1) and having a molecular weight of 1×10 ³ to 1×10 ⁵ is molded under high pressure. A method for producing a highly rigid molded article of acetylene group-containing polyurethane. (In the formula, R is the residue of a diisocyanate having 2 to 20 carbon atoms excluding NCO.) 2 In producing a highly rigid molded product of diacetylene group-containing polyurethane, diacetylene group-containing polyurethane 2. The method for producing a highly rigid molded article according to claim 1, wherein the product is molded in a solid state under high pressure of 500 atmospheres or more and at a temperature of room temperature or higher and 200° C. or lower.