JPH0431461A - High-rigidity thermoplastic polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in impact resistance and desirable as especially a molding material for engineering plastics by specifying the difference between the contents of high-molecular active hydrogen compound components in the contained components. CONSTITUTION:The title composition comprising at least two thermoplastic polyurethanes each comprising an organic polyisocyanate (desirably an aromatic diisocyanate such as diphenylmethane diisocyanate) and a low-molecular active hydrogen compound (e.g. ethylene glycol, cyclohexanediol or xylene glycol) and a high-molecular active hydrogen compound (e.g. polyether polyol or polyester polyol), wherein the difference between the contents of the active hydrogen compound is 1wt.% or above. The above composition is excellent in impact resistance, highly rigid and desirable as especially a molding material for engineering plastics.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a high-rigidity thermoplastic polyurethane composition with excellent impact resistance, and particularly to a high-rigidity thermoplastic polyurethane composition that is excellent as a molding material for engineering plastics. Regarding the composition.

(Conventional technology) Thermoplastic polyurethane has excellent mechanical strength and abrasion resistance, so it is used in a wide range of applications, including synthetic leather, spandex, adhesives, industrial parts, sporting goods, and daily miscellaneous goods. It is being said. However, these applications are for high elasticity rubber, and conventional high-rigidity polyurethanes have low glass transition points or are too low for engineering plastics.
Also, it is a material with low impact resistance and little value when used alone, so it has been used after being reinforced with glass fiber or the like.

(Problems to be Solved by the Invention) Recently, Japanese Patent Publication No. 61-54325 discloses the glass transition temperature of polyurethane prepared by reacting a polyisocyanate, a polyol, and a chain extender by a one-shot method so that it can be used as an engineering plastic. A high-rigidity polyurethane with high impact resistance is disclosed. However, this was not able to fully meet the demands of the recent increasingly sophisticated market.

(Means for Solving the Problems) In order to obtain a highly rigid thermoplastic polyurethane with further excellent impact resistance that can meet the demands of the recent increasingly sophisticated market, the present inventors have developed a molecular structure of thermoplastic polyurethane, As a result of intensive research into its composition, etc., we have completed the present invention.

That is, the present invention provides (A) an organic polyisocyanate, (B
) a low-molecular active hydrogen compound, and (C) a high-molecular active hydrogen compound; The present invention provides a highly rigid thermoplastic polyurethane composition characterized by the above characteristics. The present invention will be explained in detail below.

(Structure) Examples of the organic polyisocyanate (A) of the present invention include aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and cyclohexane diisocyanate. Aromatic sysocyanates such as alicyclic diisocyanate, toridine isocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, phenylene diisocyanate, tolidine isocyanate, and mixtures thereof can be mentioned. Among these, preferred organic polyisocyanates are aromatic diisocyanates, particularly diphenylmethane diisocyanate, phenylene diisocyanate, and tolydine isocyanate. Diphenylmethane diisocyanate (such as polyaryl polyisocyanate)
Can also be used together. Alternatively, a small amount of modified polyisocyanate, such as liquid diphenylmethane diisocyanate (carbodiimide-modified type, etc.), may also be used in combination.

As the low molecular weight active hydrogen compound (B) of the present invention, 1:! , Example C, ethylene glycol, diethylene glycol, 1
, 2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 23-butanediol, 1,4-butanediol, 1,6-hexanediol, 3-methyl 15-bentanediol, neopentyl glycol , aliphatic glycols such as octanediol, nonanediol, and decanediol; alicyclic diols such as cyclohexane diol and cyclohexane dimetatool; aromatic glycols such as bishydroxyethoxybenzene and xylene glycol; and mixtures thereof. can be mentioned. Other examples include low-molecular active hydrogen compounds such as polyether polyols, polyester polyols, polyether ester polyols, and polyalkylene polyols, which will be described in detail in the next section.

The average number of functional groups of these active hydrogen compounds (B) is preferably 1.9 or more, and the molecular weight is 50 to 400.
belongs to.

Examples of the polymer active hydrogen compound (C) of the present invention include polyether polyols, polyester polyols,
Examples include polyether ester polyols and polyalkylene polyols.

Examples of polyether polyols include compounds having a structure in which alkylene oxide is added using an active hydrogen compound such as an alcohol, phenol, carboxylic acid, or amine compound as an initiator. The above alcohols include ethylene glycol, diethylene glycol, 1
, 2-propylene glycol, 1,3-propylene glycol, 1, 3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 3-methyl 1,5-bentanediol , aliphatic diols such as neopentyl glycol, octanediol, nonanediol, and decanediol; aliphatic triols such as glycerin and trimethylolpropane;
Alicyclic diols such as cyclohexane diol and cyclohexane dimetatool; polyhydric alcohols such as pentaerythritol, sorbitol, and sucrose; aromatic diols such as bishydroxyethoxybenzene, xylene glycol, and bisphenol A; as carboxylic acids; are aliphatic dicarboxylic acids such as succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, cepatic acid, dodecanedicarboxylic acid, dimer acid, phthalic acid,
Aromatic acids or aromatic acid anhydrides such as isophthalic acid, terephthalic acid, and phthalic anhydride; examples of amine compounds include monoamines such as ammonia and butylamine;
Aliphatic polyamines such as ethylene diamine, hexamethylene diamine, and diethyl triamine; alicyclic polyamines such as cyclohexylene diamine and inphorone diamine; polyamines such as phenylene diamine, tolylene diamine, xylene diamine, diphenylmethane diamine, and polyphenyl polyamine. , piperazine, N-aminoethylpiperazine, and alkanolamines such as monoethanolamine, jetanolamine, and triethanolamine. Examples of the alkylene oxide added to the above active hydrogen compound include ethylene oxide-9ide, propylene oxide, butylene oxide, and tetrahydrofuran. The active hydrogen compound and alkylene oxide may be used alone or in combination of two or more. When propylene oxide or butylene oxide is used, from the viewpoint of reactivity, it is preferable to add ethylene oxide, which has a primary OH group at the end, in an amount such that 80% or more of primary 01-1 groups are present.

Examples of polyester polyols or polyether ester polyols include those obtained by reacting low-molecular-weight polyols (or polyether polyols) with dicarboxylic acids (or dicarboxylic anhydrides and alkylene oxides, alkaline carboxylic acids, and dialkyl carbonates). Examples include condensed polyester polyols obtained by ring-opening polymerization of lactones, and polyester polyols obtained by ring-opening polymerization of lactones. Examples of the low molecular weight polyols include ethylene glycol, diethylene glycol, 1, 2-
7” robylene glycol, 1,3-propylene glycol, 1,3-butanediol, 2゜3-butanediol, 1,4-butanediol, 1,6-hebosandiol, 3-methyl l, 5 - Aliphatic diols such as bentanediol, neopentyl glycol, octanediol, nonanediol, and decanediol, aliphatic triols such as glycerin and trimethylolpropane, and alicyclic diols such as cyclohexanediol and cyclohexane dimethatol. , bishydroxyethoxybenzene, and aromatic diols such as xylene glycol.

Further, the dicarboxylic acids include succinic acid, malonic acid,
Glutaric acid, adipic acid, pimelic acid, azelaic acid,
Examples include aliphatic dicarboxylic acids such as cepatic acid, dodecanedicarboxylic acid, and dimer acid, and aromatic acids or aromatic acid anhydrides such as phthalic acid, isophthalic acid, terephthalic acid, and phthalic anhydride.

Examples of lactones include δ-valerolactone, β-
Ethyl-δ-valerolactone, ε-caprolactone, α
-Methyl-ε-caprolactone, β-methyl-ε-caprolactone, γ-methyl-ε-caprolactone, β, δ
-dimethyl-ε-caprolactone, 3.3.5-1 dimethyl-caprolactone, enantlactone (7-hebutanolide), dodecanolactone (12-toticallide D
L).

Examples of polyalkylene polyols include polybutadiene polyols.

The polymeric active hydrogen compound (C) of the present invention may be used alone or in combination of several kinds. The usage ratio in the polyurethane composition requires that the total amount of component (C) in the selected polyurethane raw materials is 1 to 30% by weight, preferably 8 to 20% by weight. More preferably, it is 10 to 15% by weight. If it is less than 1% by weight, the resin will be brittle, and if it exceeds 30% by weight, the glass transition temperature and stiffness will be low, making it unsuitable as a high-rigidity material targeted by the present invention.

In addition, the molecular weight of the component (C) is 500 to 30,000, preferably 700 to i o o o, more preferably 10 in order to have excellent impact resistance and appropriate impact resilience.
00 to 6000, and the average number of functional groups is preferably 1.9 or more. If it is less than 1.9, the molecular weight of the thermoplastic polyurethane produced will be small and sufficient strength will not be obtained. Further, when the average number of functional groups exceeds 2, it is preferable to use one having a sufficiently large molecular weight, since it is difficult to obtain preferable thermoplasticity if the molecular weight is small. Further, if the amount used is too large, it is difficult to obtain desirable thermoplasticity, so it is preferable to reduce the amount used. The desired usage amount and molecular weight vary depending on the composition and the number of functional groups, and are determined as appropriate.

To produce the polyurethane in the composition of the present invention, organic polyisocyanate (A)/low molecular active hydrogen compound (B
) and the polymeric active hydrogen compound (C).
Group/Active hydrogen-containing group (OH2SH, NH,, NH, etc.)
=0.9-1.1 equivalent ratio, preferably 0.95-1.0
The equivalent ratio is set to 8, more preferably 0.98 to 1.05. If the number of functional groups in the active hydrogen compound is 2.0 or less, the desired strength cannot be obtained if the equivalent ratio is set low;
is set to

The manufacturing method can be a normal thermoplastic polyurethane manufacturing method. For example, thermoplastic polyurethane is usually produced by mixing and reacting organic polyisocyanate (A) with active hydrogen compounds (B) and (C) at a temperature ranging from room temperature to 120°C depending on the nature of the raw materials, and then placing it on a container or the like. Transfer and cure by heating at ambient temperature up to 250°C. The cured product is usually pulverized into flakes using a pulverizer or the like, then shaped into pellets or the like using an extruder or the like, and then subjected to a molding process.

The composition of the present invention is produced by heating and mixing, but the mixing method can be carried out simultaneously during the extrusion, pelletizing, etc. steps during production.

The temperature during mixing using an extruder is set according to the thermoplastic polyurethane having a higher melt viscosity.

It is usually set at 180 to 235°C.

The above is an example of a production method using a one-shot method, and the organic polyisocyanate (A) may be reacted with a part of the active hydrogen compound in advance.

The types of polymeric active hydrogen compounds (C) in the thermoplastic polyurethane and tan raw materials for the composition of the present invention do not need to be the same and may be different.

In the polyurethane composition of the present invention, at least two types of polyurethanes are selected so that the difference in the content of the polymer active hydrogen compound (C) component between the polyurethanes is 1% by weight or more. The difference is the difference in the amount of component (C) in each raw material polyurethane mixed into the composition, and the difference between the maximum and minimum amount of component (C) in each polyurethane. The content should be 1% by weight or more. Furthermore, preferably the value is greater than or equal to 2% by weight, most preferably 3-it
% or more of each polyurethane. If it is less than 1% by weight, the effect of improving impact resistance will be slight.

Furthermore, if there is a significant difference in melt viscosity between raw polyurethanes, extrusion becomes difficult, so it is preferable to design them so that they are almost the same. This design can be determined by trial and error by changing the ratio of NCO groups/active hydrogen-containing groups.

If the active hydrogen compound absorbs moisture, the strength of the polyurethane obtained by foaming will decrease, so in that case,
It may be dehydrated under reduced pressure at a temperature of around 0°C.

Although it is not necessary to use a catalyst, there are cases in which using a catalyst gives better results. Catalysts include organic and inorganic compounds such as bismuth, lead, tin, iron, antimony, uranium, cadmium, cobalt, l-lium, aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese, zirconium, and calcium. Examples include, but are not limited to, commonly used urethanization catalysts such as. Preferred catalysts are organometallic compounds, especially dialkyltin compounds.

Representative organotin catalysts and 17 include stannous octoate, stannous oleate, dibutyltin diacetate, dibutyltin dilaure-1, dibutyltin maleate, dibutyltin mercaptopropionate, dibutyltin dodecyl mercaptide, etc. can be mentioned.

The amount of catalyst used depends on the nature of other raw materials, reaction conditions, desired reaction time, etc. Generally, but not limited to, the catalyst is used in an amount ranging from about 0.0001% to about 5% by weight, preferably from about 0.001% to about 2% by weight, based on the total weight of the reaction mixture.

In addition, antioxidants, ultraviolet inhibitors, fillers, reinforcing fibers, and the like may be used as auxiliary materials, if necessary. These auxiliary materials are usually used by being mixed with the active hydrogen compound side.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. In the examples, "parts" means parts by weight.

The method for measuring physical properties is as follows.

(Physical property measurement method) Glass transition temperature: The maximum peak temperature of loss modulus in dynamic viscoelasticity was adopted. It is a measure of a polymer's resistance to thermal deformation.

Measuring equipment: Rheometrics R3A Type II Surface impact resistance: ASTM D 256-56 stiffness
:ASTM D 750 Example 1 Diphenymethane diisocyanate 2520 parts, 1.4
-876 parts of butanediol and 102 parts of PTMG2000 (Mitsubishi Kasei polyoxytetramethylene glycol, molecular weight 1934) (constituent amount 2.9%) were reacted at 100°C, and the resulting thermoplastic polyurethane was heated at 180°C.
After curing for 30 minutes, the mixture was crushed to obtain flaky polyurethane (referred to as polyurethane-A).

Diphenymethane diisocyanate 1965 parts, 1.4
-Butanediol 646 parts, PTMG2000 (Mitsubishi Kasei polyoxytetramethylene glycol, molecule j
l1934) 881 parts (constituent amount 25.2%) at 100°C
The thermoplastic polyurethane obtained was reacted at 180°
After curing for 0.130 minutes, the mixture was pulverized to obtain flaky polyurethane (referred to as polyurethane-B).

Polyurethane-A and polyurethane-B were heated and mixed in an extrusion molding machine at a weight ratio of 53.8746.2 to form pellets, and then injection molded to prepare specimens for measuring physical properties. The test results are shown in Table 1.

Example 2 Diphenymethane diisocyanate 2279 parts, 1.4
- 776 parts of butanediol, 446 parts of PTMG-2000 (polyoxytetramethylene glycol manufactured by Mitsubishi Kasei, molecular weight 1934) (constituent amount 12.7%) at 100°
The thermoplastic polyurethane obtained was reacted with 180
After curing at 130°C for 130 minutes, the mixture was pulverized to obtain flaky polyurethane (referred to as polyurethane-○).

Diphenymethane diisocyanate 2201 parts, 1.4
- 743 parts of butanediol, 55'6 parts of PTMG-2000 (Polyoxytetramethylene glycol manufactured by San1u Kasei, molecular weight 1934) (constituent amount 15.9%), 100 parts
The thermoplastic polyurethane obtained was reacted at 18 °C.
After curing at 0°C for 130 minutes, the mixture was pulverized to obtain flaky polyurethane (referred to as polyurethane-D).

Polyurethane-○ and polyurethane-D were heated and mixed in an extrusion molding machine at a weight ratio of 85.4/14.6 to form a pellet, and then injection molded to prepare a sample for measuring physical properties. The test results are shown in Table 1.

Example 3 Diphenymethane diisocyanate 2245 parts, 1.4
- 762 parts of butanediol, 494 parts of PTMG2000 (Mitsubishi Kasei polyoxytetramethylene glycol, molecular weight 1934) (constituent amount 14.1%) in 100 parts
The thermoplastic polyurethane obtained was reacted at 180 °C.
C. for 30 minutes and then pulverized to obtain flaky polyurethane (referred to as polyurethane-E).

Polyurethane-E and polyurethane-〇 obtained in Example 2 were heated and mixed in an extruder at a weight ratio of 68.3/31.7 to form pellets, and then injection molded to create specimens for measuring physical properties. did. The test results are shown in Table 1.

Comparative Example 1 Phenymethane diisocyanate 2265fM, 1.4
- Butanediol 770 parts and 461 parts (constituent amount 13.2%) of PTMG-2000 (Mitsubishi Kasei polyoxytetramethylene glycol, molecular weight 1934) were reacted at 100°C, and the resulting thermoplastic polyurethane was heated to 180°C.
After curing for 130 minutes, the mixture was pulverized to obtain flaky polyurethane (referred to as polyurethane-F).

Polyurethane-F was extruded into a pellet shape using an extrusion molding machine, and then injection molded to prepare specimens for measuring physical properties.

The test results are shown in Table 1.

Table 1 Content (wt%) of type (C) (C) Difference in (C) component PTMG 13.2 22.3 Force-lass transition temperature (°C) Impact strength* (kg-am/am) Bending Strength (kg/cm") Flexural modulus 18900 (kg/cm") 46.1 Example PTMG 29.4 PTMG 13.2 25.8 Comparative example PTMG 13.2 23.5 *: Isolt) 1/8 inch, notched (effects of the invention) The polyurethane composition of the present invention obtained as described above not only has improved impact resistance, but also has excellent heat distortion temperature and rigidity, as well as excellent dimensional stability. Because it can be easily molded using conventional thermoplastic resin processing methods such as injection, extrusion, and blow molding, it is extremely useful as a molding material for engineering plastics for automobile interior and exterior materials, structural parts, mechanical parts, electrical equipment, etc. Useful.

Claims (1)

[Scope of Claims] 1. Consists of at least two thermoplastic polyurethanes consisting of (A) an organic polyisocyanate, (B) a low-molecular active hydrogen compound, and (C) a high-molecular active hydrogen compound; (C) Difference in polymer active hydrogen compound component content is 1% by weight
Highly rigid thermoplastic polyurethane composition 2 characterized in that the difference in the (C) polymeric active hydrogen compound component is 2% by weight.
The highly rigid thermoplastic polyurethane composition according to claim 1, which is the above.