JP3275272B2 - Method for producing thermoplastic polyurethane resin composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a thermoplastic polyurethane resin composite material having improved surface smoothness.

[0002]

2. Description of the Related Art Thermoplastic polyurethane resins have excellent strength, cold resistance, abrasion resistance, chemical resistance and weather resistance, and are used in a wide range of fields. The thermoplastic polyurethane resin composite material to which a reinforcing material is added has particularly high rigidity, good low-temperature impact resistance, and a small coefficient of linear expansion, and is used as a structural material, for example, for housings of automobile parts and electric devices. . However, the use of glass fiber as a reinforcing material in a thermoplastic polyurethane resin composite material significantly deteriorates the surface smoothness, and its use has been limited. As a method for improving the surface smoothness of a thermoplastic polyurethane resin composite material, there is a method using a fine reinforcing material (JP-A-2-8244). As a result, good surface smoothness can be obtained, but the impact resistance at low temperatures is deteriorated, which is not suitable for use. As another method of obtaining good surface smoothness, there is a method of covering the surface of a molded product with another material during molding (EP
259676). According to this, the surface smoothness can be improved without losing the preferable characteristics of the conventional thermoplastic polyurethane resin composite material. However, since the process is complicated, the production cost is increased, and molding defects such as peeling of the coating material on the surface are liable to occur.

[0003]

The present inventors have conducted intensive studies and studies to improve the conventional disadvantages. As a result, the average diameter is 5 μm or more and 50 μm or less, and the average length is 300 μm.
By using the above fibers and fibers having an average diameter of 5 μm or less and an average length of 300 μm or less, or granules or flakes having an average particle diameter of 20 μm or less, a composite material using a reinforcing material has a reciprocity. The present inventors have found that a thermoplastic polyurethane resin composite material having both good surface smoothness and high rigidity, good low-temperature impact resistance, and a small coefficient of linear expansion at the same time can be obtained.

[0004]

That is, the present invention provides (A)
A long-chain dihydroxy compound having a molecular weight of 500 to 10,000,
A thermoplastic polyurethane resin composite material obtained by kneading a thermoplastic polyurethane resin obtained from (B) a short-chain diol having a molecular weight of 500 or less, (C) an organic diisocyanate, and if necessary (D) an additive, and (E) a reinforcing material. Manufacturing method
In (E), (E1) a fiber having an average diameter of 5 μm or more and 50 μm or less and an average length of 300 μm or more, and (E2) an average diameter of 5 μm or less and an average length of 30
Fibers of 0 μm or less, or granules or flakes having an average particle size of 20 μm or less are used in combination, and (E1) is 5 to 50 parts by weight, and (E2) is 100 parts by weight of the thermoplastic polyurethane resin. 5 to 50 parts by weight, (E
The weight ratio (E1) / (E2) of 1) and (E2) is 3/1
A method for producing a thermoplastic polyurethane resin composite material , wherein the thermoplastic polyurethane resin composite material is used in a range of from 1 to 5.

[0005] The thermoplastic polyurethane resin used in the method for producing a thermoplastic polyurethane resin composite material of the present invention includes (A) a long-chain dihydroxy compound having a molecular weight of 500 to 10,000, (B) a short-chain diol having a molecular weight of 500 or less, (C) An organic diisocyanate and, if necessary, (D) an additive, and (A), (B) and (C) are resins satisfying the following relationship. (A) / (B) = 1 / 0.1 to 1/15 (mol ratio) {(A) + (B)} / (C) = 1 / 0.9 to 1 / 1.2 (mol ratio) Here, the long-chain dihydroxy compound (A) having a molecular weight of 500 to 10,000 is one or more long-chain dihydroxy compounds selected from polyester glycol, polyether glycol, polyester ether glycol and polycarbonate diol. .

As the polyester glycol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane glycol, 1,8-octane glycol, neopentyl glycol, 2-methylpropane Diol, 3-methyl-1,5-pentanediol, methyl-1,8-octane glycol, 1,9-nonane glycol, 1,1
Polycondensates of 0-decane glycol or other low molecular weight diol components with glutanic acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, or other low molecular dicarboxylic acids or lactones Examples thereof include polycaprolactone diol, polypropiolactone diol, polyvalerolactone diol, and polymethyl valerolactone diol obtained by ring-opening polycondensation.

[0007] As polyether glycol,
Examples thereof include polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyhexamethylene glycol, and other copolymerized polyoxyalkylene glycols. Particularly, a polyoxyalkylene glycol having an alkylene oxide having 4 or more carbon atoms as a constituent unit is preferable.

Further, as the polycarbonate diol, low molecular weight diols such as 1,4-butanediol,
1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexane glycol, 1,8-
Polycarbonate diols obtained by condensing aliphatic or alicyclic diols such as octane glycol, methyl-1,8-octane glycol, 1,9-nonane glycol, and 1,10-decane glycol with diphenyl carbonate or phosgene to cause condensation. Can be

Short-chain diol having a molecular weight of 500 or less (B)
As aliphatic or alicyclic diols, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane glycol, diethylene glycol, 2-methyl-
1,3-propanediol, 3-methyl-1,5-pentanediol, 1,8-octaneglycol, methyl-
1,8-octane glycol, 1,9-nonane glycol, 1,10-decane glycol, cyclohexane glycol, cyclohexyl dimethanol, 1,4-bishydroxyethoxybenzene, and the like. Can be selected and used.

The organic diisocyanate includes aromatic,
Alicyclic or aliphatic diisocyanates such as 4,4
'-Diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, toluene diisocyanate, 2,2'-dimethyl-4,4'-diphenylmethane diisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) benzene, paraphenylene diisocyanate , Naphthalenediisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 1,4
-Cyclohexyl diisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, and the like.
More than one species can be selected and used. In addition, as additives, antioxidants, ultraviolet absorbers, hydrolysis inhibitors,
Lubricants, pigments and the like can be mentioned, and these can be used as needed.

In producing the thermoplastic polyurethane resin, a known method is employed. For example, a long-chain dihydroxy compound (A) and a short-chain diol (B) may be heated and melted and mixed in a high-viscosity reaction vessel, and the organic diisocyanate (C) may be added thereto and reacted. If a twin screw extruder is used as a reactor, a thermoplastic polyurethane resin can be continuously produced.

The average diameter used in the present invention is 5 μm or more and 5 μm or more.
0 μm or less and an average length of 300 μm or more (E
1) is an inorganic fiber such as a glass fiber, a carbon fiber, a silicon carbide fiber, and an alumina fiber, or a polyamide fiber;
Organic fibers such as polyaramid fiber, polyester fiber and polyoxymethylene fiber. These can be used alone or in combination of two or more. Particularly preferred are glass fibers.

The fibers (E2) having an average diameter of 5 μm or less and an average length of 300 μm or less used in the present invention are as follows.
Mineral fibers or the like composed of metal oxides mainly composed of potassium titanate, calcium silicate, magnesium sulfate and silica, and granular or flakes (E2) having an average particle diameter of 20 μm or less include glass beads, glass flakes , Talc, mica, calcium carbonate and clay powder. These can be used alone or in combination of two or more. Preferred are potassium titanate fibers, mineral fibers composed of silica-based metal oxides, glass flakes and mica, particularly preferred are mica.

Each of (E1) and (E2) is used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the thermoplastic polyurethane resin, and (E1) and (E2) are in a weight ratio of (E1).
1) Used in the range of 3/1 to 1/5 in (E2). When only (E1) is used as the reinforcing material, the obtained composite material has high rigidity, good low-temperature impact resistance, and small coefficient of linear expansion, as in the case of the conventional thermoplastic polyurethane resin composite material, but the surface smoothness is low. Notably inferior. When only (E2) is used as the reinforcing material, the resulting composite material has good surface smoothness, but is significantly inferior in rigidity, low-temperature impact resistance and linear expansion coefficient as compared with the conventional one. (E1) and (E
Even in the case where the combination of 2) is used, if it is out of the above range, any of surface smoothness, rigidity, low-temperature impact resistance, and coefficient of linear expansion are reduced. By using (E1) and (E2) in the above range, the obtained thermoplastic polyurethane resin composite material has good surface smoothness while maintaining high rigidity, good low-temperature impact resistance and small coefficient of linear expansion. It is possible to also have the property. In addition, since the method does not include a step of covering the surface of the molded body with another material for improving the surface properties, the molding can be performed by a simple process using an ordinary injection molding machine as it is. Therefore, the thermoplastic polyurethane resin composite material according to the present invention can provide a molded article having both high rigidity, good low-temperature impact resistance, small linear expansion coefficient and good surface smoothness at low production cost.

The reinforcing material according to the present invention is kneaded with a thermoplastic polyurethane resin using a kneader such as a kneader or a continuous kneader having a single shaft or two or more shafts. In kneading, these reinforcing materials are supplied alone or mixed with each other, or mixed with a thermoplastic polyurethane resin, and supplied from a supply port provided in the kneader. In some cases, a forced supply is used. By supplying the thermoplastic polyurethane resin and the reinforcing material to the kneader using a constant-rate supply device, a homogeneous thermoplastic polyurethane resin composite material can be obtained.

Further, the reinforcing material according to the present invention is mixed with a long-chain dihydroxy compound which is a raw material of a thermoplastic polyurethane resin and then subjected to a urethanization reaction, or these reinforcing materials are added simultaneously with the reaction of the thermoplastic polyurethane resin. By kneading, the thermoplastic polyurethane resin composite material may be produced simultaneously with the reaction of the thermoplastic polyurethane resin. These reinforcing materials may be surface-treated according to a known method by a surface treating agent such as a silane coupling agent or a titanate coupling agent, if necessary, during or before kneading with the thermoplastic polyurethane resin. .

[0017]

The thermoplastic polyurethane resin composite material obtained according to the present invention has high rigidity, good low-temperature impact resistance and a small coefficient of linear expansion, and at the same time has good surface smoothness. In addition, since there is no step of covering the surface of the molded body with another material to improve the surface properties, it is possible to use an ordinary injection molding machine as it is and to perform molding in a simple process, thereby reducing production costs. It is.

[0018]

The following examples are provided to clarify the effects of the present invention, but the present invention is not limited thereto. In each of the examples, the reinforcing materials (E1) and (E2) according to the present invention were kneaded with a thermoplastic polyurethane resin and granulated using a twin-screw extruder. The obtained pellets of the thermoplastic polyurethane resin composite material were molded by an in-line screw injection molding machine, and the flexural modulus, linear expansion coefficient, low-temperature impact resistance, surface sharpness, and average roughness were measured. In the examples and comparative examples, all “parts” indicate parts by weight.

Example 1 Poly (butylene adipate) diol (molecular weight 200
0) 46 parts, 1,4-butanediol 13 parts, 4,4 '
100 parts of a thermoplastic polyurethane resin produced from 41 parts of diphenylmethane diisocyanate is kneaded with 14 parts of surface-treated glass fiber (10 μm diameter, 3 mm length) and 29 parts of mica (average particle size: 3 μm) to form a thermoplastic polyurethane. A resin composite material pellet was obtained.

Example 2 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (diameter 6 μm, length 6 mm).
14 parts and 29 parts of mica (average particle size: 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 3 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (23 μm diameter, 9 mm
Long) and 14 parts of mica (average particle size: 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 4 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 3 mm
Long) and 14 parts of mica (average particle size: 12 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 5 100 parts of the same thermoplastic polyurethane resin as in Example 1 was treated with surface-treated glass fibers (10 μm diameter, 6 mm
Long) and 14 parts of mica (average particle size: 20 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 6 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 0.5 m
29 parts of m (m length) and 14 parts of mica (average particle diameter 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

EXAMPLE 7 A glass fiber (10 μm diameter, 0.35
(mm length) 33 parts and mica (average particle diameter 3 μm) 33 parts were kneaded to obtain a thermoplastic polyurethane resin composite material pellet.

Example 8 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 10 mm
Length) and 27 parts of mica (average particle size: 20 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 9 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 3 mm
Long) 12 parts and mica (average particle size 3 μm) 6 parts were kneaded to obtain a thermoplastic polyurethane resin composite material pellet.

Example 10 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 6 mm
Long) 10 parts and mica (average particle diameter 3 μm) 50 parts were kneaded to obtain a thermoplastic polyurethane resin composite material pellet.

Example 11 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 0.5 m
(m length) and 50 parts of mica (average particle size of 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 12 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 0.35
(mm length) 50 parts and mica (average particle diameter 3 μm) 17 parts were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 13 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 3 mm
Length) 14 parts and mineral fiber (5 μm diameter, 125 μm length) 29
And the mixture was kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 14 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 6 mm
14 parts) and 29 parts of mineral fibers (5 μm diameter, 75 μm length) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 15 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 9 mm
Length) 14 parts and mineral fiber (5 μm diameter, 200 μm length) 29
And the mixture was kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 16 Poly (butylene adipate) diol (molecular weight: 100
0) 44 parts, 1,4-butanediol 12 parts, 4,4 '
To 100 parts of a thermoplastic polyurethane resin produced from 44 parts of diphenylmethane diisocyanate, the same reinforcing material as in Example 1 was kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Example 17 Poly (caprolactone) diol (molecular weight: 2000) 4
6 parts, 13 parts of 1,4-butanediol, and 100 parts of a thermoplastic polyurethane resin produced from 41 parts of 4,4'-diphenylmethane diisocyanate are kneaded with the same reinforcing material as in Example 1 to form a thermoplastic polyurethane resin composite. A pellet of material was obtained.

Example 18 Poly (oxytetramethylene) glycol (molecular weight: 10
00) 44 parts, 1,4-butanediol 12 parts, 4,
A thermoplastic polyurethane resin composite material pellet was obtained by kneading 100 parts of a thermoplastic polyurethane resin produced from 44 parts of 4'-diphenylmethane diisocyanate with the same reinforcing material as in Example 1.

Comparative Example 1 Surface-treated glass fibers (diameter: 10 μm, diameter: 3 mm) were added to 100 parts of the same thermoplastic polyurethane resin as in Example 1.
Long) 14 parts were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Comparative Example 2 29 parts of mica (average particle size: 3 μm) were kneaded with 100 parts of the same thermoplastic polyurethane resin as in Example 1 to obtain a pellet of a thermoplastic polyurethane resin composite material.

Comparative Example 3 100 parts of the same thermoplastic polyurethane resin as in Example 1 were treated with surface-treated glass fibers (10 μm diameter, 6 mm
Long) and 2 parts of mica (average particle size: 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Comparative Example 4 Surface-treated glass fibers (diameter: 10 μm, 3 mm) were added to 100 parts of the same thermoplastic polyurethane resin as in Example 1.
Length) and 4 parts of mica (average particle size: 3 μm) were kneaded to obtain a thermoplastic polyurethane resin composite material pellet.

Comparative Example 5 Surface-treated glass fibers (diameter: 10 μm, 6 mm) were added to 100 parts of the same thermoplastic polyurethane resin as in Example 1.
Length) and 80 parts of mica (average particle size: 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Comparative Example 6 Surface-treated glass fibers (diameter: 10 μm, 0.5 μm) were added to 100 parts of the same thermoplastic polyurethane resin as in Example 1.
(mm length) and 100 parts of mica (average particle size: 3 μm) were kneaded to obtain pellets of a thermoplastic polyurethane resin composite material.

Comparative Example 7 The same thermoplastic polyurethane resin as in Example 16 was mixed with 100 parts of the same reinforcing material as in Comparative Example 1 to obtain pellets of a thermoplastic polyurethane resin composite material.

With respect to the above Examples and Comparative Examples, the evaluation methods of the flexural modulus, coefficient of linear expansion, low-temperature impact resistance, surface sharpness and average roughness are shown below, and the results are shown in Table 1.
In Table 1 (E1), the average fiber length (μm) in the pellets after kneading is shown in parentheses together with the fiber length before kneading.

Evaluation method Flexural modulus: JIS K72
According to 03. Coefficient of linear expansion: 8 test pieces of 200 × 100 × 3 mm
After holding at 0 ° C. and 0 ° C. for 3 hours, the dimension of the resin in the flow direction at the time of molding was measured, and the coefficient was calculated from the change. Low-temperature impact property: According to JIS K7110. The measurement temperature was −30 ° C. Sharpness: The surface of a 200 × 100 × 3 mm test piece was measured using a portable clarity gloss meter manufactured by Tokyo Koden Co., Ltd. Average roughness: The surface of a 200 × 100 × 3 mm test piece was measured using a surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd. Evaluation criteria Linear expansion coefficient (× 10 ^-6 ° C. ^-1 ) Excellent; Less than 10 Good; 10-20 Acceptable; 21-40 Not possible; 41 or more Izod impact (kJ / m ² ) Excellent; 12 or more Good; 10-11 Acceptable 8-9 unacceptable; 7
Less than sharpness value (PGD) excellent; 0.6 or more good; 0.4-0.5 acceptable; 0.3
Not possible; 0.2 or less

[0045]

[Table 1]

Claims (3)

(57) [Claims] 1. A thermoplastic polyurethane obtained from (A) a long-chain dihydroxy compound having a molecular weight of 500 to 10,000, (B) a short-chain diol having a molecular weight of 500 or less, (C) an organic diisocyanate and, if necessary, (D) an additive. Thermoplastic polyurethane resin kneading resin and (E) reinforcing material
In the method for producing a resin composite material, (E) includes (E1) a fiber having an average diameter of 5 μm to 50 μm and an average length of 300 μm or more;
2) Fibers having an average diameter of 5 μm or less and an average length of 300 μm or less, or granules or scales having an average particle diameter of 20 μm or less are used in combination, and based on 100 parts by weight of the thermoplastic polyurethane resin ( E1) from 5 to 5
0 parts by weight, (E2) 5 to 50 parts by weight, (E1) / (E2) weight ratio (E1) / (E2) 3/1 to 1
The method for producing a thermoplastic polyurethane resin composite material , wherein the thermoplastic polyurethane resin composite material is used in the range of / 5. 2. The method for producing a thermoplastic polyurethane resin composite material according to claim 1, wherein glass fiber is used as (E1). 3. The method for producing a thermoplastic polyurethane resin composite material according to claim 1, wherein mineral fiber or mica is used as (E2).