JPS61115927A - Thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin excellent in weather resistance, low- temperature flexibility and abrasion resistance, by reacting a hydroxy-terminated polyalkylene phthalate and polytetramethylene glycol with a diisocyanate. CONSTITUTION:A thermoplastic resin obtained by reacting 50-95wt% hydroxyl- terminated polyalkylene phthalate (A) of a number-average MW of 300-3,000 and 50-5wt% polytetramethylene glycol (B) [the sum of (A) and (B) is 100wt%] with a diisocyanate having the structure of the formula. When the number- average MW of the polyalkylene phthalate used is below 300, the resin is lacking in flexibility. When it exceeds 3,000, the resin has an undesirably decreased abrasion resistance. Therefore it is desirable that the number-average MW is 500-2,000. The polytetramethylene glycol contributes to improvement in, especially, low-temperature flexibility.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel thermoplastic resin having excellent weather resistance, flexibility in cold and cold conditions, and abrasion resistance.

Polyurethane resins have long been expected to be used in many applications due to their excellent physical properties such as flexibility and abrasion resistance. Because it is easy to manufacture, it is difficult to mold it by one injection molding, and the actual situation is that it cannot be used sufficiently as a thermoplastic resin, so it has been mainly used as a thermosetting resin.

The present invention provides a new polyester polyurethane thermoplastic resin that overcomes the drawbacks of conventional thermoplastic polyurethane resins, has excellent weather resistance and flexibility especially in cold weather, and can be manufactured by extrusion or injection molding. It is something to do.

That is, the present invention comprises: 30-93% by weight of a hydroxyl group-terminated polyalkylene phthalate having a factor average molecular weight of 300-3000; It is a thermoplastic resin obtained by reacting with a diisocyanate having a structure.

The above-mentioned polyalkylene 7-talates include, for example, terephthalic acid, dimethyl terephthalate, isophthalic acid, 7-thalic anhydride, 7-thalic acids such as orthophthalic acid, phthalic anhydride, or 7-thalic acids such as alcohol esters of 7-thalic acid. system compounds, such as ethylene glycol, fluoropylene gellicol, /, hirobutanediol, /, 3-butanediol,
Neopentyl glycol, /, j-bentanediol, /
, 6-hexanediol, dodecanediol, and other alkylene glycols, and is produced by dehydration condensation or transesterification using conventionally known methods. At this time, the number average molecular weight of the polyalkylene 7-talate is adjusted by making the number of equivalents of the hydroxyl group of the alkylene glycol in excess of the number of equivalents of the carboxyl group (including anhydride and alcohol ester group) of the 7-talic acids. can. Therefore, it is important to complete the above-mentioned dehydration condensation or transesterification reaction as much as possible so that both molecular ends of the polyalkylene terephthalate have hydroxyl groups. At this time, the reaction rate is calculated from the comparison with the theoretical value by measuring the OH number at the end of the reaction, and the reaction rate is controlled so that the reaction rate based on carboxyl (or carboxyalkyl ester) is qS coefficient or higher, preferably qg coefficient or higher. be done. In addition, the number average molecular weight of the above-mentioned polyalkylene 7-talate/phthalate is calculated from the measurement of the OH value, and the weight of the polyalkylene 7-talate is the sum of the number of OH groups and the number of equivalents of unreacted end groups. Twice the divided value is defined as the number average molecular weight.

If the number average molecular weight is less than 300, the flexibility will be insufficient, and if it is more than 300, the abrasion resistance will decrease and it will be unsuitable.
In particular, it is preferable that the number average molecular weight is 300 to 2,000.

Among the above-mentioned 7-thalic acid-based compounds, those having a terephthalic acid skeleton and an isophthalic acid skeleton are preferred), and among the above-mentioned alkylene glycols, ethylene glycol having the target molecular structure, /diol, neopentyl glycol, and /e-hexanediol are particularly preferred.

The above polytetramethylene glycol 0 is a diol having hydroxyl groups at both molecular ends obtained by ring-opening polymerization of tetrahydrofuran, and for the purpose of the present invention, those having a number average molecular weight of ≠OO to 3000 are preferable. Thus, polytetramethylene glycol contributes to improving flexibility, especially during cold resistance.

Diisocyanates with the structure α, α, α′, α′
-tetramethyl metaxylylene diisocyanate and α, Iα, α', α'-tetramethyl para-xylylene diisocyanate.

The above Ω diisocyanate has an equivalent number of isocyanate groups equal to the total number of equivalents of hydroxyl groups of the above non-polyalkylene phthalate and β-polytetramethylene glycol /:0. wo~/:/,/, preferably /:θri5~
/ : i0! The thermoplastic resin of the present invention is obtained by addition condensation at a ratio such that; Also, the ratio of polyalkylene phthalate and 6-polytetramethylene glycol used is: jtO~9jt'l'/C to 1. fB Kaj
O-jT weight '4 C (the sum of AJ and ■ is 100 weight factor), and the prisoner! If the content is less than 93% by weight, the strength will be insufficient, and if the content exceeds 93% by weight, the flexibility in cold weather will decrease, making it impossible to achieve the object of the present invention. In particular, it is preferable that a is ≠o-io weight % with respect to the weight ratio O-de θ.

In the above reaction of polyalkylene phthalate, 0 polytetramethylene glycol and Ω diisocyanate, 6 and q may be reacted at the same time, but either 2 or B may be reacted with an excess amount of diisocyanate. It is preferable to react in advance with ^ or a and then add the remaining ^ or a to complete the reaction.

In addition, conventionally widely used diisocyanates, such as t
In the reaction of tolylene diisocyanate or diphenylmethane diisocyanate, etc. with a polyhydroxy compound, at a temperature where the viscosity of the resulting resin is sufficient to allow mixing and the reaction to proceed uniformly, branching due to allophanate by-product may occur. However, it is difficult to obtain resins that can be easily formed, and it is necessary to proceed with the reaction in a large amount of organic solvent at low temperatures to control side reactions, which requires energy and volumetric efficiency to remove the organic solvent. Productivity is significantly lower in this respect. On the other hand, the diisocyanate with the above ρ does not react slowly with the hydroyacyl group, and is less likely to produce allophanate as a by-product, so it is heated at a temperature where the viscosity is sufficient to allow a uniform reaction, e.g. 100 to 200°O. At temperature,
The thermoplastic resin of the present invention can be produced without using an organic solvent. Of course, this does not preclude the use of inert organic solvents in this reaction process, i.e., the reaction of the above ^alkylene 7-talate and 0 tetramethylene glycol with the above diisocyanate of ρ is
Normally, it can be carried out at /θθ~200°0. Also,
When an organic solvent is used, the reaction temperature may be 100° or less, and a reaction accelerator such as organic tin, organic lead, or tertiary amine may also be used in combination. When an organic solvent is used, the organic solvent is distilled off in vacuo, or the thermoplastic resin of the present invention is poured into a solvent such as hydrocarbons with stirring, coagulated and precipitated, and then dried. The thermoplastic resin of the present invention can be obtained in this manner.

The thermoplastic resin of the present invention preferably has a weight average molecular weight of 20,000 or more from the viewpoint of the strength of the molded product sheet etc. In particular, it is preferably 80,000 to 800,000 from the viewpoint of both moldability and strength. I like it.

The thermoplastic resin of the present invention has excellent weather resistance, flexibility in cold and cold conditions, and abrasion resistance. It can be used for a variety of purposes, such as as a coating for wire rods such as optical fibers, and can be applied to the above uses by ordinary thermoplastic resin processing methods such as extrusion film formation, injection molding, extrusion coating, and press processing. Ru.

In addition, when the thermoplastic resin of the present invention is put into practical use, coloring pigments, extender pigments, fillers such as reinforcing fibers such as glass fibers and metal fibers, antioxidants,
Auxiliary agents such as ultraviolet absorbers, mold release agents, and lubricants can be used depending on the purpose.

It is also possible to use the thermoplastic resin of the present invention in combination with other thermoplastic resins or thermosetting resins. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Reference Example Synthesis of Polyalkylene Phthalate Into a reactor equipped with a stirrer, a condenser, and a thermometer, each of the raw materials (AJ to ■) shown in Table 1 was charged, and heated until the internal temperature reached 150°C. Tetrabutoxytitanium equivalent to 0.1% by weight based on the weight of the raw materials was added as a reaction accelerator, and the internal temperature was raised at a rate of 15°C per hour while distilling off the water or methanol produced, until the final temperature was 210°C. ℃ and allowed to react for the time shown in Table 1 (time from the start of dehydration or demethanolization to the end of the reaction) to obtain each polyalkylene phthalate (D+). From the measurement of the OH value of (D), The obtained reaction rates and number average molecular weights are also listed in Table 1. (1) Synthesis of thermoplastic resin by addition condensation: Polymers with the weights shown in Examples/-6 in Table 2 Tetramethylene glycol and diisocyanate are placed in a reactor having a stirrer, a thermometer, a condenser, a nitrogen inlet and a heatable dropping tank,
The mixture was heated and stirred while flowing nitrogen into the gas phase, and the first stage reaction was carried out at the temperature and time shown in Table 1. Next, each polyalkylene phthalate listed in Table 2 was heated and dissolved in a dropping tank.
It was added into a reactor and a second stage reaction was carried out at the temperature and time listed in Table 2 to obtain the thermoplastic resins of the present invention in Examples/--B. It was confirmed that the reaction of each resin proceeded almost quantitatively from the infrared absorption spectrum of the residual incyanate group. Further, the weight average molecular weight of each resin was measured by the GPC method (polystyrene equivalent value) and is also listed in Table 2.

(2) Evaluation of thermoplastic resin: Each thermoplastic resin of Examples 1 to 6 was tested with a screw diameter of 40
Extruded through a T-die at each temperature listed in Table 8 using a Hida extruder, wound up through a cooling roll at 50°C, and
obtained the film.

The tensile strength and elongation of the obtained film were measured at room temperature and -40℃.
In addition, an abrasion resistance test and a Quesar-Ometer irradiation test were conducted, and the results are listed in Table 8.

Comparative Example 1 Using the same apparatus as that used for the synthesis of thermoplastic resin by addition condensation in Example above, polytetramethylene glycol (
Number average molecular weight 500) 200 parts by weight and α, α, αI
, 866 parts by weight of αl-tetramethyl metaxylylene diisocyanate were heated and mixed at 140'C for 2 hours, and then bishydroquine ethylene terephthalate (molecular weight 254
) 800 parts by weight was added and further heated and mixed at 150° C. for 8 hours, and it was confirmed that the residual inanate group had disappeared from the infrared absorption spectrum, and a thermoplastic resin was obtained. The weight average molecular weight of this resin was 58,000.

Using this resin, a 50μ film was obtained in the same manner as in the Examples, and evaluated in the same manner as in the Examples, and the results are also listed in Table 8.

Comparative Example 2 Dimethyl terephthalate 1164
Parts by weight and 767 parts by weight of 1.6-hequitinediol were charged, and 0.1% by weight of tetrabutoxytitanium was added to the above raw materials as a reaction accelerator, and the reaction was carried out for 24 hours in the same manner as in the example. The amount of methanol distilled out was 768
The reaction rate is 100%, calculated from the hydroxyl value in parts by weight.
The number average molecular weight was 8,094.

140 parts by weight of the above polyalkylene phthalate
While melting at ℃, 104 parts by weight of α, α, α', αI-tetramethyl metaxylylene diisocyanate was added.
After heating for a while, 150 parts by weight of polytetramethylene glycol (number average molecular weight 1000) was added, and the mixture was heated to 150°C.
After reacting for 4 hours, it was confirmed that the residual incyanate groups had disappeared from the infrared absorption spectrum, and a thermoplastic resin was obtained. The weight average molecular weight of this resin was 'Zq million.

Using this resin, a film of Sθμ was obtained in the same manner as in the example, and evaluated in the same manner as in the example, and the results are shown in Table I.
C will also be described.

Comparative Example 3 The polytetramethylene glycol (number average molecular weight SO
Parts by weight of O>μQ and 24.3 parts by weight of α, α, α', α'-tetramethyl metaxylylene diisocyanate were reacted under the same conditions as in Experiment No. (zl), and then the polyalkylene phthalate 60 parts by weight of q was added, and a two-stage reaction of ta was carried out under the same conditions as in Experiment No. (1) to obtain a thermoplastic resin having a weight average molecular weight of ft.i:A million.

Do exactly the same as the example! A film of rθμ was prepared and evaluated. The evaluation results are also listed in Table 3IC.

Comparative Example Hiro's polytetramethylene glycol (number average molecular weight/!
f00)! ! j; -0 parts by weight and α, α, α′, α′-tetramethyl metaxylylene diisocyanate 2AgTL
Amounts were reacted under the same conditions as in Experiment No. (5), and then the polyalkylene 7-talate ρtt,! A second stage reaction was carried out under the same conditions as in Experiment No. (5) to obtain a thermoplastic resin having a weight average molecular weight of 1Aj-10,000.

SOμ films were prepared and evaluated in exactly the same manner as in the examples. The evaluation results are also listed in Table 3.

Comparative example S Polyalkylene phthalate C)ioo listed in Table 1.

Dissolve part by weight with /j O'O, add 3q7 to α.

α,α′,α′-tetramethylmethaxylylene diisocyanate was added dropwise over 7 hours, and further /! A thermoplastic resin of a comparative example was synthesized by heating and mixing at O°O for 2 hours. The weight average molecular weight was /a30,000. Next, a 5'Qμ film was prepared and evaluated in the same manner as in the example. The results are also listed in Table 3.

Claims (1)

[Claims] (1) (A) 50-95% by weight of hydroxyl-terminated polyalkylene phthalate having a number average molecular weight of 300-3000 and (B) 50-5% by weight of polytetramethylene glycol [
The sum of (A) and (B) is 100% by weight] is reacted with (C) a diisocyanate having the structure of general formula ▲ Numerical formula, chemical formula, table, etc. ▼.