JPH0335054A - Thermoplastic polyurethane composition - Google Patents

Abstract

PURPOSE:To provide a composition having excellent heat resistance, injection moldability, cold resistance and mechanical performance by compounding a specific polyurethane AES resin. CONSTITUTION:A thermoplastic polyurethane composition comprises 92-99wt.% of a thermoplastic polyurethane and 8-1wt.% of a resin prepared by graft- polymerizing an aromatic vinyl compound and a cyanized vinyl compound to ethylene-propylene copolymer rubber, the polyurethane being obtained from (A) a polymer diol having a number-average mol.wt. of 1500-3500, (B) a diisocyanate and (C) a chain extender, the sum of the weight o the components B and C being 23-56% based on the sum of the weights of the components, and the polymer diol being selected from a polyesterdiol prepared from a 4-10C diol and a 6-10C dicarboxylic acid the sum of the carbon numbers of both the monomers being in a range of 10-16, a 6C lactone polyesterdiol and a polycarbonatediol prepared from a 5-10C diol.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is a resin obtained by graft polymerizing a specific thermoplastic polyurethane, a small amount of ethylene-propylene rubber, an aromatic vinyl compound and a cyanide vinyl compound , which is abbreviated as AES resin).

The composition provided by the present invention has excellent heat resistance and injection moldability, as well as excellent heat resistance and mechanical performance.

[Conventional technology]

Conventional thermoplastic polyurethane has many features such as high elastic modulus, excellent abrasion resistance and oil resistance, so it is attracting attention as an alternative material to rubber and plastic. 1 Ordinary plastic molding methods can be applied to it. It has come to be used in large quantities as a molding material in a wide range of applications. Thermoplastic polyurethanes are made from polymeric diols, diincyanates, and chain extenders such as 1,4-butanediol.

Mold release properties (prevention of stickiness) during molding of thermoplastic polyurethane
In order to improve the temperature dependence of melt viscosity,
Attempts have been made to use thermoplastic polytale tough 90-10% by weight and AES resin 1-90% by weight (see Japanese Patent Publication No. 17281/1981 and Japanese Patent Publication No. 34265/1983).

[Problem to be solved by the invention]

Conventional thermoplastic polyurethane has extremely poor heat resistance, long injection molding cycle times, poor productivity, and problems with injection moldability such as sink marks. It is requested.

Since the resin composition made of the above-mentioned thermoplastic polyurethane and AES resin contains a large amount of AES resin,
Although the adhesion of thermoplastic polyurethane is improved, there are problems in that the original characteristics of thermoplastic polyurethane are lost, such as increased hardness, decreased elongation, and decreased bending resistance.

An object of the present invention is to provide a thermoplastic polyurethane composition having excellent heat resistance and injection moldability.

[Means to solve the problem]

According to the present invention, the above objects are achieved by (4) thermoplastic polystyrene resin having a weight of 92 to 99% and a resin obtained by graft polymerizing an aromatic vinyl compound and a vinyl cyanide compound to a homogeneous ethylene-propylene rubber. 8 to 1% by weight, the thermoplastic polyurethane is obtained from (a) a polymeric diol having a number average molecular weight of 1,500 to 3,500, (b) a diincyanate, and (c) a chain extender, and The sum of the weights of components (b) and (c) is component (a)% (b
) and (c), and the polymeric diol has (a-1) 4 to 4 carbon atoms.
10 diol and a dicarboxylic acid having 6 to 10 carbon atoms, and the sum of the carbon numbers of the diol and the dicarboxylic acid is in the range of 10 to 16, (a-2) carbon number A thermoplastic polyurethane characterized by being one or a mixture of two or more selected from the group consisting of lactone-based polyester diols of No. 6 and polycarbonate diols obtained from a-3 diols having 5 to 10 carbon atoms. This is accomplished by providing a composition.

The injection molding cycle speed is fast in the composition of the present invention;
In order to highly exhibit properties such as excellent heat resistance, it is essential that the thermoplastic polyurethane has the above-specified structure. In the case of a thermoplastic polyurethane composition that does not have this specified structure, the effects exhibited by the composition of the present invention are hardly observed.

It is extremely important that the polymeric diol constituting the thermoplastic polyurethane in the present invention has a number average molecular weight in the range of 1,500 to 3,500, determined from the hydroxyl value and acid value. Its number average molecular weight is especially 1.80
It is preferably in the range of 0 to 3,000.

When the number average molecular weight is less than 1,500, there is almost no improvement in injection molding cycle speed, molding strain rate, and heat resistance, and when it exceeds 3,500, there is a large change in melt viscosity during molding. Stable molding becomes difficult.

The above polymeric diol is obtained from (a-X) a diol having 4 to 10 carbon atoms and a dicarboxylic acid having 6 to 10 carbon atoms,
and a polyester diol (a
-2) One or a mixture of two or more selected from the group consisting of lactone-based polyester diols having 6 carbon atoms and (a-3) polycarbonate diols obtained from diols having 5 to 10 carbon atoms.

When two or more diols or dicarboxylic acids constituting the polyester diol (a-1) are used. The sum of the number of carbon atoms in the diol and the number of carbon atoms in the dicarboxylic acid means the number determined as follows. For example, when a diol with 6 carbon atoms and a diol with 10 carbon atoms are used in a molar ratio of 50:50, the number of carbon atoms in the diol is s (6X0,5+
10X0.5). When the sum of the carbon numbers of the diol and the dicarboxylic acid is less than 10, the effect of improving the heat resistance and injection moldability of the composition is small, and when the sum of the carbon numbers exceeds 16, When molding the composition, the melt viscosity changes significantly over time, resulting in poor moldability and a large drop in cold resistance. Polyester diol (!L
-1), examples of diols having 4 to 10 carbon atoms include 1.4-butanediol, 11.5-hentanediol, 1,6-hexanediol, 1.7-hebutanediol, 1.8-octane Examples include diol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, and the like.

Examples of the dicarboxylic acid having 6 to 10 carbon atoms include adipic acid, azelaic acid, and sebacic acid.

Lactone-based polyester diol having 6 carbon atoms (a-2)
is obtained by ring-opening polymerization of a lactone having 6 carbon atoms. The carbon number of the lactone giving the lactone-based polyester diol (a-2) and the polycarbonate diol (jL-3
If the number of carbon atoms in the diol giving ``) is smaller than the above range, the effect of improving the heat resistance and injection moldability of the composition will not be sufficient; When molding the composition, the melt viscosity changes significantly over time, resulting in poor moldability and a large drop in cold resistance.

In the thermoplastic polyurethane of the present invention, the sum of the weights of components (b) and (c), that is, the weight of the hard segment component is 23 to 56% of the sum of the weights of components (a) and (b) and (c). It is important that it be within the excellent range. When the weight of the hard segment component is less than 23%, the effect of improving the injection moldability and heat resistance of the composition is small, and when it exceeds 56%, the change in melt viscosity of the composition over time is This results in poor moldability.

The thermoplastic polyurethane in the present invention is obtained by melt polymerizing a polymeric diol, a diisocyanate, and a chain extender. The diincyanates used include aliphatic compounds containing two incyanate groups in the molecule;
Alicyclic or aromatic diincyanates, such as 4,4'-diphenylmethane diincyanate)% p-
722 diisocyanate, tolylene diisocyanate), 1,5-naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate,
Examples include inphorone diincyanate and 4,4'-dicyclohexylmethane diincyanate.

Among the diisocyanates, 4. ．． 4'-diphenylmethane diisocyanate is preferred. As a chain extender, a commonly used chain grower in the polyurethane industry, that is, a low molecular compound with a molecular weight of 400 or less containing at least two hydrogen atoms capable of reacting with incyanate, such as ethylene glycol, propylene glycol, etc. can be used. , 1,4-butanediol, neopentyl glycol, 1゜6-hexanediol, 3-methyl-1,
Nosiols such as 5-bentanediol, 1,4-cyclohexanediol, 1,4-bis(β-hydroxyethoxy)benzene, bis(β-hydroxyethyl)terephthalate, xylylene glycol; ethylenediamine, propylenediamine, xylylenediamine, in Examples include diamines such as phorondiamine, piperazine, and phenylenediamine (%) V diamine; hydrazine; hydrazides such as adipic acid dihydrazide and inphthalic acid dihydrazide; As a chain extender, 1,4-butanediol (mari) 11,4-bis(β-hydroxyethoxy)
It is most preferable to use benzene. These compounds may be used alone or in combination of two or more.

As the polymerization conditions, conditions employed in known urethane production reactions are applied, but it is preferable to employ a temperature in the range of 200 to 240°C as the polymerization temperature.

By keeping the polymerization temperature at 200°C or higher, a polyurethane with good shapeability and workability can be obtained, and by keeping the polymerization temperature at 240°C or lower, a polyurethane with increased heat resistance can be obtained. can.

As the polymerization method, it is particularly preferable to employ a continuous melt polymerization method using a multi-screw extruder.

In the composition of the present invention, blending the thermoplastic polyurethane having the above specified structure and the AIS resin in a specific ratio is an important requirement in order to achieve the above objects of the present invention. In the present invention, thermoplastic polyester polyester 9
If the blending ratio of 2 to 99% by weight and AES resin resin 8% fat is less than 1%, the effect of the present invention will hardly be exhibited, and if it exceeds 8%, the hardness of the composition will decrease. increases and the elongation decreases. Therefore, A
When comparing a composition having an increased hardness with a blending ratio of gS resin of more than 8% by weight and a composition of the present invention having the same hardness, the former composition has a polyurethane node segment. If the content of the latter composition is lower than that of the latter composition, the heat resistance and bending resistance will be lower than that of the latter composition, and the original characteristics of thermoplastic polyurethane will be impaired, and its applications will be limited. Be what you are.

The AgS resin used in the present invention is a resin obtained by graft polymerizing an aromatic vinyl compound and a vinyl cyanide compound to ethylene-propylene rubber. As the ethylene-propylene rubber, ethylene-propylene copolymer rubber and fluoropylene-diene copolymer rubber are used. The weight ratio of ethylene and propylene is preferably in the range of 9:1 to 2:8. Further, as the diene monomer, norbornenes such as alkenylnorbornene, cyclic dienes such as dicyclopentadiene, aliphatic dienes such as hexadiene, etc. are used. The diene monomers may be used alone or in combination of two or more. Examples of aromatic vinyl compounds used in graft polymerization include styrene,
α-methylstyrene b-nuclear alkyl-substituted styrene, nucleus No. 1
Zero-gen substituted styrene is used. It is particularly preferred to use styrene. Furthermore, examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile. Particular preference is given to using acrylonitrile. The weight ratio of the ethylene-propylene rubber to the vinyl compound used for graft polymerization, such as an aromatic vinyl compound or a vinyl cyanide compound, is 5:95 to 50:
A range of 50 is appropriate. AgS resin can be produced using bulk polymerization method, emulsion polymerization method, solution polymerization method, bulk-suspension polymerization method, F! ! In the turbidity polymerization method, thermoplastic polyurethane and AgS resin are premixed in a predetermined ratio using a vertical or horizontal mixer commonly used for mixing resin materials, and - axial load or It is produced by heating and kneading in a batch or continuous manner using a shaft extruder, mixing roll, Banbury mixer, or the like.

Additives such as stabilizers, plasticizers, montanic acid waxes, lubricants such as aliphatic amide, fillers, antistatic agents, pigments, etc. to further improve light resistance and heat resistance during mixing may be added without impairing the effects of the present invention. It is possible to add in small amounts.

The thermoplastic polyurethane composition of the present invention has particularly excellent molding processability including injection moldability, and heat resistance, and can be used in commonly used injection molding machines, extrusion molding machines, blow molding machines, calendars, etc. It is easily molded. The thermoplastic polyurethane composition of the present invention has high molding dimensional accuracy, and has excellent heat resistance, cold resistance, oil resistance, abrasion resistance,
Due to its toughness and mechanical performance, it can be used in sheets, films, rolls, gears, solid tires, snow tires, snow chains, belts, watch bands, hoses, tubes, backing materials, anti-vibration materials, soles, sports shoes, and various other products. Used as material for laminated products, mechanical parts, automobile parts, sporting goods, elastic fibers, etc. Further, the thermoplastic polyurethane composition of the present invention can be dissolved in a solvent and used for artificial leather, coating agents, fiber treatment agents, adhesives, binder paints, etc.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, in the reference examples, the number average molecular weight was determined according to the following method. In the Examples and Comparative Examples, the injection moldability (molding cycle time), heat resistance, cold resistance, bending resistance, and hardness of the thermoplastic polyurethane compositions were evaluated according to the following methods. The hard segment content of a thermoplastic polyurethane means the weight proportion in the thermoplastic polyurethane of segments based on diisocyanates and chain extenders.

(1) Number average molecular weight: Determined based on the hydroxyl value and acid value of the polymeric diol.

(2) Heat resistance and cold resistance: A dynamic viscoelasticity measuring device [DVE Rheospectra manufactured by Rheology] was applied to a test piece prepared from a polyurethane composition film with a thickness of 500μ obtained by extrusion molding. The storage elastic modulus E(1o o ) (dyne/c!A) at 100° C. was measured using E(100), and the heat resistance was evaluated as E(100). A material with a large value has excellent heat resistance. In addition, regarding test pieces made from polyurethane composition films of the same thickness,
Using the same dynamic viscoelasticity measuring device, pTα(
The peak temperature of 1 lHz) was measured, and the cold resistance was evaluated based on this.

(A) Injection moldability: Injection molding is performed while changing the molding cycle time (injection time + cooling time), and the molding cycle time at which sink marks and deformation do not occur in the obtained molded product is measured.
Injection moldability was evaluated using this method.

(4) Flexibility = 500μ (thickness) x 70mm x 45
The bending resistance of the No. 111 test piece at 20° C. was examined using a bending resistance tester according to the method specified in JIS K-6545. The bending resistance was evaluated by the number of times the test piece was bent until it cracked.

(6) Hardness: Evaluated by Shore hardness A according to the method specified in JIS K-6301.

Reference Example 1 Production of polyester diol A mixture of 1.4-butanediol and 1.6-hexanediol (molar ratio = 50:50) 1.35Of and adipic acid 1.460f (molar ratio of diol/adipic acid = 1) .3/1.0) was charged into a reactor, and while nitrogen gas was passed into the system under normal pressure, the condensed water was distilled out of the system at a temperature of about 220° C. to carry out an esterification reaction. When the acid value of the polyester became 0.3 or less, the degree of vacuum was gradually increased using a vacuum pump to complete the reaction. The polyester diol thus obtained had a hydroxyl value of 56, an acid value of 0.1 (1), and a number average molecular weight of 2,000.

Reference Examples 2 to 7 Manufacture of polyester diol The esterification reaction was carried out in the same manner as in Reference Example 1, except that dicarboxylic acids giving the dicarboxylic acid components and diols giving the diol components shown in Table 1 were used, respectively.
Polyester diols shown in Table 1 were obtained.

Reference Example 8 Production of polycarbonate diol Mixture of 1.6-hexanediol and 1,9-nonanediol (molar ratio = 70:30) 1.41O under nitrogen stream
f and diphenyl carbonate) 2.1402 was charged into a reactor and heated to 200° C., and the raw phenol was distilled out of the system. Gradually increase the temperature to 210-220℃
After raising the temperature to 100.degree. C. and distilling most of the phenol out of the system, the pressure inside the system was reduced to 6 to 10 .mu.Hg, and the remaining phenol was completely distilled out of the system at the same temperature under this reduced pressure. The polycarbonate diol thus obtained has a hydroxyl value of 56.
0, and a number average molecular weight of 2,000.

Reference Examples 9 and 10 The reaction was carried out in the same manner as in Reference Example 8, except that diols giving the diol components shown in Table IK were used, and ethylene carbonate was used instead of diphenyl carbonate, to obtain polycarbonate diols shown in Table 1. .

For the polyester diols obtained in Reference Examples 1 to 7 and the polycarbonate diols obtained in Reference Examples 8 to 10, what are the proportions of the diol component and hiso, the dicarboxylic acid component and its proportion, and the number average molecular weight? The results are summarized in Table 1.

In Table 1, diol components and dicarboxylic acid components are represented by diols and dicarboxylic acids represented by the following abbreviations, respectively.

EG, ethylene glycol BD: 1,4-butanediol HD: 1,6-hexanediol ND: 1,9-nonanediol MPG: 2-mefk-1,3-gua pandio-/I/A
D: Adipic acid Az: 7 Zelaic acid SA: Sebacic acid Table Example 1 Production and performance evaluation of polyurethane composition Polyester diol (A) and 1,4-butanediol (hereinafter referred to as
This is abbreviated as BD) at a molar ratio of 1:4.
℃, and 4,4-diphenylmethane diincyanate (hereinafter referred to as MDI) heated and melted at 50℃ was added to the polyester diol (4) vs. MDI vs. B.
An amount of D having a molar ratio of 1:5:4 was continuously charged into a twin-screw extruder rotating in the same direction using a metering pump, and a continuous melt polymerization reaction was carried out. When the interior of this twin-screw extruder was divided into three zones: a front section, a middle section, and a rear section, the temperature (polymerization temperature) of the middle section, which was the highest temperature, was set at 230°C. The polyurethane produced was continuously extruded into water in the form of a strand, and then formed into pellets using a pelletizer.

100 parts of the obtained polyurethane pellets, 3 parts of KAF:S resin (manufactured by Japan Synthetic Rubber, AES 110) and o and s parts of montanic acid wax (Hoechst wax OP) were added to a 25 mm diameter extruder (cylinder temperature 200°C, die The mixture was mixed and added at a temperature of 180° C.) to form pellets. Next, the pellets of the obtained polyurethane composition were molded using an injection molding machine (manufactured by Mekuseki Resin Kogyo, FS80S12AES, cylinder temperature 175-200°C, nozzle temperature 200°C, mold temperature 30°C, injection pressure 100 kf/dG). ,
Injection molding was performed while changing the molding cycle time (injection time + cooling time) to produce molded products (150 sm x 25 x 6 x 2). The molding cycle time required for the resulting molded product to stop causing deformation and temperature rash was measured. Molding the pellets of the above-mentioned polyurethane composition in accordance with the above-mentioned method,
Heat resistance, cold resistance, bending resistance and hardness were evaluated. The evaluation results are shown in Table 2.

Comparative Example 1 Production and Performance Evaluation of Polyurethane Composition Pellets of polyurethane composition were obtained by the same operation as in Example 1 except that AES resin was not added, and the pellets were injection molded in the same manner to produce a molded product. did. The same evaluation as in Example 1 was performed, and the evaluation results are shown in Table 2.

Examples 2 to 9 and Comparative Examples 2 to 16 Production and performance evaluation of polyurethane composites In Example 1, the polymer diol shown in Table 2 was used instead of polyester diol (4), and the molar ratio shown in Table 2 was used. Cypolyurethane pellets were obtained by carrying out the reaction and operation in the same manner except that the polymer diol, MDI and BD were charged.

These pellets were treated with AE as in Example 1.
Pellets of polyurethane compositions were obtained with or without addition of S resin at a predetermined ratio, and these pellets were injection molded in the same manner to produce molded products. Example 1
We performed the same evaluation as in
Shown below. In the table, PCL means polycaprolactone diol (manufactured by Dainippon Ink & Chemicals) having a number average molecular weight of 2,000.

Example 10 Production and Performance Evaluation of Polyurethane Composition Polyurethane pellets were obtained by carrying out the reaction and operation in the same manner as in Example 1 except that p-phenylene diin cyanate was used instead of MDI. This pellet was subjected to the same operations as in Example 1 to obtain pellets of the polyurethane composition, and the pellets were injection molded in the same manner to produce a molded article. The same evaluation as in the actual test was carried out, and the evaluation results are shown in Table 2.

Example 11 Production and performance evaluation of polyurethane composition In Example 1, 1,4-bis(hydroxyethoxy) was used instead of BD.
Polyurethane pellets were obtained by performing the reaction and operation in the same manner except that benzene was used. A polyurethane composition was obtained using the pellets in the same manner as in Example 1, and the pellets were injection molded in the same manner to produce molded articles. The same evaluation as in Example 1 was performed, and the evaluation results are shown in Table 2.

〔Effect of the invention〕

As is clear from Table 2 above, the thermoplastic polyurethane composition provided by the present invention is excellent in all of heat resistance, injection moldability, cold resistance, bending resistance, and hardness. The composition also has excellent oil resistance, abrasion resistance, toughness, and mechanical performance.

Claims (1)

[Claims] (A) Thermoplastic polyurethane 92-99% by weight and (
B) 8 to 1% by weight of a resin obtained by graft polymerizing an aromatic vinyl compound and a vinyl cyanide compound to ethylene-propylene rubber, and the thermoplastic polyurethane has (a) a number average molecular weight of 1,500 to 3; , 500 polymeric diol, (b) diisocyanate and (c) chain extender, and the sum of the weights of components (b) and (c) is ), and the polymeric diol is in the range of 23 to 56% of the sum of the weights of (
a-1) A polyester diol obtained from a diol having 4 to 10 carbon atoms and a dicarboxylic acid having 6 to 10 carbon atoms, and in which the sum of the number of carbon atoms in the diol and the number of carbon atoms in the dicarboxylic acid is in the range of 10 to 16. , (a-2) lactone polyester diol having 6 carbon atoms and (a-3) 5 to 1 carbon atoms
A thermoplastic polyurethane composition characterized in that it is one type or a mixture of two or more types selected from the group consisting of polycarbonate diols obtained from 0 diols.