JPH0848740A - Polyurethane - Google Patents

Abstract

PURPOSE:To obtain a polyurethane excellent in color fastness and transparency by specifying the constitution of polyol components in a polyurethane that is obtained by reaction the polyol components, an organic diisocyanate component, and a chain-extending agent. CONSTITUTION:In a polyurethane that is obtained by reacting polyol components, an organic diisocyanate component (e.g. diphenylmethane diisocyanate), and a chain-extending agent (e.g. 1,4-buthanediol), the polyol components are made up of a polyether diol containing ether units which are preferably the same (e.g. a polytetramethylene glycol) and a polyether-modified polycarbonate diol (e.g. a modified polycarbonate diol obtained by using, as an aliphatic diol, 1,6-hexanediol and a polytetramethylene glycol) in an amount of 15 to 60% based on the weight of the polyol components.

Description

Detailed Description of the Invention

The present invention relates to a novel polyurethane, and more particularly to a polyurethane excellent in discoloration resistance and transparency.

It is well known that polyurethane is produced by using polyester diol, polyether diol or polycarbonate diol as a polyol component and reacting these with an organic diisocyanate and a chain extender. However, polyurethane using polyester diol as a polyol component has a drawback that it is inferior in water resistance and mold resistance. In addition, polyurethane using adipate-type or lactone-type polyester diol has a high glass transition temperature and poor low temperature recovery property. There is a drawback that. Polyurethanes using polyether diol as a polyol component generally have high crystallinity and are liable to become cloudy. Furthermore, polyurethane using polycarbonate diol as a polyol component has the drawbacks of poor flexibility, low elongation, high glass transition temperature, and poor low-temperature recoverability.

Recently, in order to improve the drawback of polycarbonate diol which gives polyurethane having a high glass transition temperature, a polycarbonate obtained by reacting at least one selected from alkylene carbonate, diaryl carbonate, dialkyl carbonate and the like with an aliphatic diol. It has been proposed to use a polyether-modified polycarbonate diol, which is a diol, in which an aliphatic diol is a mixture of a polyhydric alcohol having 20 or less carbon atoms and a polyether polyol having a molecular weight of 300 to 2000, as a polyol component (Japanese Patent Application Laid-Open No. HEI 2). -255822). Polyurethanes using this polyether-modified polycarbonate diol have good chemical resistance and discoloration resistance, but have a problem of low elongation and lack of practicality.

Therefore, as a result of investigations aimed at eliminating such problems, the present inventors have found that when a polyether diol and a specific amount of a polyether-modified polycarbonate diol are used together as a polyol component, discoloration resistance and The present invention has been completed by finding that polyurethane having excellent transparency and excellent physical properties such as elongation can be obtained.

Thus, the present invention is a polyurethane obtained by the reaction of a polyol component, an organic diisocyanate component and a chain extender, the polyol component being 15 to 15 parts by weight based on the weight of the polyether diol and the polyol component.
A polyurethane comprising 60% by weight of a polyether modified polycarbonate diol.

The polyurethane of the present invention will be described in more detail below.

The polyether diol used as the polyol component in the present invention is a polymer diol containing a plurality of ether bonds (COC) in the chain,
For example, ethylene oxide, propylene oxide,
Polyether diol obtained by ring-opening polymerization of cyclic ether such as tetrahydrofuran; ethylene glycol, propylene glycol, 1,4-butane diol,
1,5-pentanediol, neopentyl glycol,
Polyether diols obtained by polycondensation of glycols such as 1,6-hexanediol and 3-methyl-1,5-pentanediol are included. These polyether diols can generally have a number average molecular weight in the range of 1000 to 5000, preferably 1500 to 3000. Among them, polytetramethylene glycol is preferable.

The polyether-modified polycarbonate diol used in combination with the above-mentioned polyether diol includes, for example, dialkyl carbonate such as dimethyl carbonate and diethyl carbonate; alkylene carbonate such as ethylene carbonate and propylene carbonate; diphenyl carbonate and diphenyl carbonate. A polycarbonate diol obtained by reacting at least one organic carbonate selected from diaryl carbonates such as naphthyl carbonate with an aliphatic diol, wherein the aliphatic diol is ethylene glycol, propylene diol having a carbon number of 20 or less, 1 , 4-butanediol,
1,5-pentanediol, neopentyl glycol,
A mixture of a low-molecular glycol such as 1,6-hexanediol and 3-methyl-1,5-pentanediol and a polyether diol having the above-mentioned polyether diol and having a molecular weight of 300 to 2000, in a weight ratio. Is a low molecular glycol: polyether diol = 2: 8 to 8:
2, preferably a polymeric diol obtained by transesterification at 4: 6 to 6: 4, generally 1000
It can have a number average molecular weight in the range of 5,000, preferably 1500 to 3,000. Such polyether-modified polycarbonate diol can be produced, for example, by the method described in JP-A-2-255822.

In the present invention, in particular, a polyether-modified polycarbonate diol containing the same ether unit, which is produced by using the same polyether diol as the polyether diol used, particularly a polyether in which the ether component is polytetramethylene glycol It is desirable to use a modified polycarbonate diol together.

The above polyether-modified polycarbonate diol has a content of 15-60 based on the weight of the polyol component.
%, Preferably 20 to 50%. The amount of polyether modified polycarbonate diol used is 1
If it is less than 5%, the polymer tends to become cloudy and the discoloration resistance tends to be inferior. On the other hand, if it exceeds 60%, the strength becomes high and the discoloration resistance becomes good, but the yellowness of the polymer increases and the elongation is improved. May be impractical because it becomes smaller.

As the organic diisocyanate component, any organic diisocyanate such as aliphatic, alicyclic, aromatic, and araliphatic compounds usually used in the production of polyurethane can be used. 4,
4'-diphenylmethane diisocyanate, tolylene diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate,
Paraphenylene diisocyanate, 4,4'-cyclohexyl methane diisocyanate, etc. are mentioned, and these can be used individually or in combination of 2 or more types.

As the above-mentioned organic diisocyanate, those having a molecular weight of 500 or less are usually preferable, and among them,
4,4'-Diphenylmethane diisocyanate is preferred.

Further, as the chain extender, a low molecular weight compound having two active hydrogen atoms capable of reacting with an isocyanate group and generally having a molecular weight of 500 or less is used, and specific examples thereof include ethylene glycol and propylene glycol. Aliphatic diols such as 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol and 3-methyl-1,5-pentanediol; paraxylylene glycol, di- Aromatic or alicyclic diols such as β-hydroxyethoxybenzene, spiroglycol and cyclohexylglycol can be used. Among them, the preferred chain extender is 1,4-butanediol. These may be used alone or in combination of two or more.

The production of polyurethane from the above-mentioned polyol component, organic diisocyanate component and chain extender can be carried out by a method known per se. Usually, isocyanate-terminated prepolymer is prepared by reacting the polyol component with the organic diisocyanate. It is preferred to prepare the polymer and then react this prepolymer with a chain extender. At that time, the polyether diol as the polyol component and the polyether modified polycarbonate diol may be mixed in advance, or may be added separately at the time of preparing the prepolymer.

The polyol component, the organic diisocyanate component and the chain extender are used in such a ratio that the molar ratio of NCO group / OH group is 0.9 to 1.2 because of the physical properties and polymerization stability. It is preferable in terms.

Further, when producing the above-mentioned polyurethane, additives such as a stabilizer, a colorant, a lubricant, a catalyst, a flame retardant and a filler may be added, if necessary.

The polyurethane of the present invention produced as described above contains a lot of flexible ether bonds in the polymer structure, and has high flexibility and high strength due to the presence of carbonate group having high polarity. Can be obtained.

Moreover, since it is a polymer having high transparency and high resistance to discoloration, when this polymer is used as a fiber, the knitted fabric surface of the product which has been subjected to the dyeing step can be finished neatly.

When this polymer is used as a fiber, it can be spun by a method known per se, but melt spinning is preferable from the viewpoint of process safety and handling of the stock solution.
When performing melt spinning, pelletizing may be carried out by an extruder, and reaction may be carried out in the extruder for continuous spinning, but in particular, the reaction stability and operability are good, and Continuous spinning with a small heat history applied to is preferred.

Next, the present invention will be described more specifically with reference to examples. "Parts" are parts by weight.

[0021]

【Example】

Example 1 Polytetramethylene glycol having a molecular weight of 2000 (PT
MG) 80 parts polyether modified polycarbonate diol (ECD) having a molecular weight of 2000 (using 1,6-hexanediol and polytetramethylene glycol as an aliphatic diol: Daicel Corp., PLACCEL C
D-221T) (20 parts) and diphenylmethane diisocyanate (MDI) (40 parts) were reacted under a nitrogen stream at 80 ° C. for 70 minutes to obtain a prepolymer.

After defoaming the prepolymer, it was continuously fed to 1,4-butanediol (BDO) at a weight ratio of 100: 6.4 to a reactor and reacted at 230 ° C.

This polymer was continuously supplied to a spinning nozzle with a heater, wound at a spinning speed of 400 m / min, and subjected to physical property measurement as a 40 denier monofilament. The ECD wt% in the polyol is given as the ECD wt% for all polyols used in the polymer synthesis. In this embodiment, it is 20%.

Example 2 In the preparation of the prepolymer of Example 1, a molecular weight of 200
70 parts in place of 80 parts of PTMG of 0 and molecular weight of 200
A monofilament was produced in the same manner as in Example 1 except that 30 parts of ECD of 0 was used instead of 20 parts of ECD to measure the physical properties. The ECD weight% in the polyol is 30%.

Example 3 In the preparation of the prepolymer of Example 1, a molecular weight of 200
50 parts and molecular weight 2000 instead of 80 parts PTMG
A monofilament was produced in the same manner as in Example 1 except that 50 parts of ECD was used instead of 20 parts of ECD, and the monofilament was measured. The ECD weight% in the polyol is 50%.

Comparative Example 1 In the preparation of the prepolymer of Example 1, a monofilament was prepared in the same manner as in Example 1 except that ECD was not used and 80 parts of PTMG having a molecular weight of 2000 was used instead of ECD to measure the physical properties. I served. This thread had a large discoloration.

Comparative Example 2 In the preparation of the prepolymer of Example 1, a molecular weight of 200
90 parts and molecular weight 2000 instead of 80 parts PTMG
A monofilament was produced in the same manner as in Example 1 except that 10 parts of ECD was used instead of 20 parts of ECD, and the monofilament was measured. The ECD weight% in the polymer is 10%.
This thread had a large discoloration.

Comparative Example 3 A monofilament was produced in the same manner as in Example 1 except that PTMG was not used and 100 parts of ECD having a molecular weight of 2000 was used in the preparation of the prepolymer of Example 1, and the monofilament was subjected to measurement of physical properties. Although this yarn has a low discoloration property, the spun yarn has a yellowish tint and has a low elongation and is not practical.

The physical properties of the monofilaments obtained in the above Examples and Comparative Examples were measured by the methods described below.

Breaking strength: measured by a tensile tester (SS-207D-UAD manufactured by Orientec Co., Ltd.) at a temperature of 20 ° C.
It was performed under the condition of a humidity of 65%. The sample length was 2 cm and the tensile speed was 300 mm / min.

Draw-out elongation: The yarn was fed from the cheese at a speed of 5 m / min, the winding speed was increased by 10 m / min, and the winding speed at the time of breaking was measured under the same temperature and humidity conditions as described above. The elongation was calculated according to the following formula.

[0032]

[Equation 1]

Normal- temperature strain: The measurement was carried out under the same conditions with the same device as the breaking strength measurement. The measurement conditions were such that the sample length was 4 cm, the tensile speed was 300 mm / min, and the elongation recovery was performed twice at the maximum elongation rate of 300%, and the residual strain value at the second time was measured.

Ultraviolet treatment: The yarn was wound around a vinyl chloride plate and irradiated with xenon lamp (low temperature cycle weather meter, manufactured by Suga Test Instruments Co., Ltd.) for 40 hours. Then, the color difference (ΔYI) was measured with a color difference meter.

NO _x resistance treatment: The yarn was wound around a vinyl chloride plate and treated for 45 minutes while controlling the NO _x concentration to 650 ppm by the NO _x generator. Then, using a color difference meter,
Was measured.

Chlorine treatment: Wrap a thread around a vinyl chloride plate,
Immerse in an aqueous solution (room temperature) having a chlorine concentration of 30 ppm for 5 hours. After washing and drying, ΔYI was measured by a color difference meter.

Color difference measurement: ND-1 manufactured by Nippon Denshoku Industries Co., Ltd.
It was measured using 001DP.

Each sample was subjected to the above treatment and the color difference (ΔYI) before and after the treatment was measured. PTM in each process
The color difference of the G100% sample (filament of Comparative Example 1) was set to 100, and the color change rate of each sample was calculated by the following formula.
As shown in Table 1, the discoloration rate of the filaments of the examples was small in any of the treatments.

[0039]

[Equation 2]

X: ECD wt% (ΔYI) _o : Color difference of 100% PTMG sample (Comparative Example 1) (ΔYI) _x : Color difference of each sample The results of the above-mentioned measurement of physical properties are shown in Table 1 below.

[0041]

[Table 1]

As is clear from the above results, the polyurethane of the present invention (1) has a carbonate group having high polarity and chemical stability, so that the polymer has high transparency and little discoloration. High flexibility because it contains many flexible ether groups in the polymer structure. (3) Polyether diol as a polyol component and polyether modified polycarbonate diol have good compatibility and are easy to handle. It has an excellent effect.

Claims (4)

[Claims] 1. A polyurethane obtained by reacting a polyol component, an organic diisocyanate component and a chain extender, wherein the polyol component is a polyether diol,
Polyurethane characterized in that it comprises 15-60% of polyether-modified polycarbonate diol based on the weight of the polyol component. 2. The polyurethane according to claim 1, wherein the polyether diol and the polyether modified polycarbonate diol contain the same ether unit. 3. A polyether diol and a polyether-modified polycarbonate diol each containing 1000 to 5
The polyurethane of claim 1 or 2 having a number average molecular weight in the range of 000. 4. A polyurethane elastic fiber comprising the polyurethane according to claim 1.