JP3373599B2 - Thermoplastic resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which is flexible and has excellent heat resistance. 2. Description of the Related Art Ethylene copolymers containing a considerable amount of a copolymer component are excellent in flexibility, processability and the like, and are used in various fields by utilizing their features. However, since its melting point is so low that its performance is significantly reduced at high temperatures, it cannot be used as it is for parts exposed to high temperatures, such as automotive interior materials. As a means for improving the heat resistance of the ethylene copolymer, there is a method of cross-linking the copolymer. However, in many cases, the workability is impaired, and thus the field of use has been limited. As another method for improving the heat resistance, a method of blending a thermoplastic polymer having a high melting point or a high softening point can be considered. However, in a normal case, if the blending ratio is small, no significant improvement was observed. Although the heat resistance is improved by increasing the blending amount, thermoplastic polymers having a high melting point or softening point are generally hard, and thus sacrificing flexibility, which is a feature of the ethylene copolymer. There were many things. [0003] In view of the above situation, the present inventors have developed a method for effectively improving heat resistance while taking advantage of the excellent processability, flexibility and the like of an ethylene copolymer. Study was carried out. As a result, they have found that a composition having desired physical properties can be obtained when an appropriate amount of a thermoplastic resin having heat resistance is mixed with two specific ethylene copolymers. Accordingly, an object of the present invention is to provide a thermoplastic resin composition having excellent flexibility, processability, and heat resistance. According to the present invention, an ethylene content is 50 to 90% by weight and a (meth) acrylic acid content is 1%.
~ 35 wt%, (meth) acrylate content is 5
４０40% by weight of ethylene / (meth) acrylic acid / (meth) acrylate copolymer or its ionomer (A): 5 to 70 parts by weight;
90% by weight, the content of unsaturated dicarboxylic acid monomer selected from the group consisting of unsaturated dicarboxylic acids, anhydrides and half esters thereof is 0.01 to 10% by weight, and the content of (meth) acrylate is 9%. .99 to 59.99% by weight
Ethylene / unsaturated dicarboxylic acid monomer, (meth) acrylate copolymer (B) ... 5 to 70 parts by weight and thermoplastic resin (C) having a melting point or softening point of 110C or more ... 20-60 parts by weight [however, (A) + (B)
+ (C) is 100 parts by weight]. In the present invention, the component (A) has an ethylene content of 50 to 90% by weight, preferably 55 to 8% by weight.
5% by weight, (meth) acrylic acid content is 1 to 35% by weight, preferably 4 to 20% by weight, (meth) acrylic acid ester content is 5 to 40% by weight, preferably 10 to 35%
% By weight of ethylene / (meth) acrylic acid / (meth) acrylate copolymer or preferably its ionomer. Here, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acrylic ester means acrylic ester or methacrylic ester. More specifically, (meth) acrylates include methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate,
2-ethylhexyl acrylate, methyl methacrylate,
Examples thereof include isobutyl methacrylate. Although the above-mentioned unneutralized copolymer can be used as the component (A), it is preferable to use the ionomer because a composition having better heat resistance can be obtained.
As the ionomer, various metal species can be used. For example, monovalent metals such as lithium, sodium and potassium, and divalent metals such as calcium, magnesium and zinc can be exemplified as typical examples. It is preferred to use ionomers. The degree of neutralization in the ionomer is, for example, 1 to 100 mol%, preferably 10 to 100 mol%.
１００100 mol%. [0007] The (meth) acrylic acid or the metal salt thereof in the component (A) is considered to be an important component exhibiting the combined effect with the component (B).
Acrylic esters play a major role in imparting flexibility. Considering mechanical properties and workability, (A)
As the components, those having a melt flow rate at 190 ° C. and a load of 2160 g of 0.01 to 200 g / 10 min, particularly about 0.1 to 100 g / 10 min are preferably used. (A) Using a radical initiator as a component, ethylene, (meth) acrylic acid and (meth)
A random copolymer obtained by copolymerizing an acrylic acid ester, or an ionomer obtained by reacting the random copolymer with a metal compound can be used. As the component (A), a partially saponified ethylene / (meth) acrylate copolymer obtained by the same high-temperature and high-pressure polymerization can also be used. The component (B) in the present invention has an ethylene content of from 40 to 90% by weight, preferably from 50 to 80% by weight, and an unsaturated dicarboxylic acid, an unsaturated anhydride thereof and a half ester thereof. When the content of the dicarboxylic acid monomer is 0.01 to 10% by weight, preferably 0.1 to 10% by weight.
5 to 5% by weight, the content of (meth) acrylate is 9.99 to 59.99% by weight, preferably 14.5 to 4
9.5% by weight of ethylene / unsaturated dicarboxylic acid monomer
A (meth) acrylate copolymer is used. By having an unsaturated dicarboxylic acid in the above range, (A)
The combined effect with the component appears. Further, the ester content is preferably in the above range for imparting flexibility. The unsaturated dicarboxylic acid monomer is exemplified by fumaric acid, maleic acid, maleic anhydride, itaconic anhydride, norbornene-2,3-dicarboxylic anhydride, monomethyl maleate, monoethyl maleate and the like. be able to. As the (meth) acrylic acid ester, the same ones as those described above as the copolymerization component of the component (A) can be exemplified. As the component (B), a random copolymer obtained by copolymerizing ethylene, an unsaturated dicarboxylic acid monomer and a (meth) acrylate at a high temperature and a high pressure,
Alternatively, ethylene / (meth) acrylate random copolymer obtained by copolymerization under high temperature and high pressure
A graft polymer obtained by graft-polymerizing an unsaturated dicarboxylic acid monomer can be used. These components (B) also include 190 ° C., 216
Melt flow rate at 0 g load is 0.01-20
It is preferable to use one having 0 g / 10 min, especially 0.1 to 100 g / 10 min. Methods for producing these components (A) and (B) are already widely known. In the present invention, in addition to the components (A) and (B), a hard thermoplastic resin (C) having a melting point or softening point of 110 ° C. or higher, preferably 130 to 300 ° C., is used. Here, the melting point is a temperature showing the maximum endothermic peak based on a differential scanning calorimeter (DSC), and can be measured when the thermoplastic resin (C) is a crystalline polymer. on the other hand,
When the thermoplastic resin (C) is an amorphous polymer, since an endothermic peak based on DSC is not observed, ASTM D-
The Vicat softening point in the 1525 test may be in the above range. Examples of the thermoplastic polymer (C) include polyolefins such as polyethylene, polypropylene, poly-1-butene and poly-4-methyl-1-pentene, nylon 6, nylon 66, nylon 11, nylon 12, exemplified by polyamides such as terephthalic acid, isophthalic acid, hexamethylenediamine copolyamide, polyesters such as polyethylene terephthalate, polytetramethylene terephthalate, polyarylate, polycarbonate, polysulfide, polysulfone, polymethyl methacrylate, polyacetal, polyphenylene oxide, etc. can do. The mixing ratio of the components (A), (B) and (C) varies depending on the type thereof.
Parts by weight, preferably 10 to 60 parts by weight of the component (B)
70 parts by weight, preferably 10 to 60 parts by weight, and component (C) is 20 to 60 parts by weight, preferably 25 to 50 parts by weight. By blending the two kinds of flexible components (A) and (B) and the component (C) having excellent heat resistance in a specific ratio as described above,
A resin composition having both unexpected flexibility and heat resistance can be obtained. The thermoplastic resin composition of the present invention comprising (A), (B) and (C) is easily obtained by melt-kneading using a usual kneading apparatus, for example, a screw extruder, a pressure kneader, a Banbury mixer or the like. be able to. Various additives can be added to the thermoplastic resin composition of the present invention, if necessary. Such additives include silica, alumina, titanium oxide, calcium carbonate, talc,
Inorganic fillers such as clay, glass powder, glass fiber, carbon fiber, and carbon black, antioxidants, ultraviolet absorbers, weather stabilizers, antistatic agents, lubricants, various pigments, dyes, flame retardants, and the like can be given. . The thermoplastic resin composition of the present invention is excellent in flexibility, heat resistance and moldability, and can be used for extrusion molding, injection molding, hollow molding, press molding, vacuum molding, air pressure molding and the like. Molded articles of various shapes can be manufactured by the molding method. For example, taking advantage of the above-mentioned features, it can be used for various malls, drainers, gaskets, interior and exterior parts of automobiles such as door materials, sports goods such as golf ball core materials or cover materials, architectural civil engineering products, daily necessities, electric components and the like. it can. EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, the raw materials used for preparing the compositions and the methods for evaluating the performance of the obtained compositions are as follows. (1) Raw material resin (A) component (ethylene / (meth) acrylic acid / (meth)
Acrylic acid ester copolymer) ethylene, methacrylic acid and isobutyl acrylate,
Using a tank reactor, pressure 240-250Mpa, temperature 200-220 ° C
T-butyl peroxyoctoate as a polymerization catalyst
Base polymer resulting ethylene-methacrylic acid-isobutyl acrylate copolymer by using copolymer
And the theoretical amount of Na ₂ CO ₃ (terpolymer ionomer
-,) Or stoichiometric ZnO (terpolymer iono)
The following four types of terpolymer ionomers obtained by neutralizing the following terpolymer at 230 to 250 ° C. in an extruder were used. [Table 1] E: ethylene MA: iBA methacrylate: isobutyl acrylate Component (B) (ethylene / unsaturated dicarboxylic acid monomer /
(Meth) acrylic ester copolymer) The following two types of maleic acid-containing resins were used, and a glycidyl group-containing ethylene copolymer was used for comparison. Note that
Maleic acid containing resin, maleic acid containing resin base
Both polymers and glycidyl group-containing flexible resins
Tylene and each comonomer were put in a tank reactor at a pressure of 240
~ 250Mpa, temperature 200 ~ 220 ° C, t-butyl as polymerization catalyst
Produced by copolymerization with peroxyoctoate
Built. (1) a maleic acid-containing resin of ethylene / methyl acrylate / monoethyl maleate copolymer composition: 64.8 / 31 / 4.2 wt% (2) maleic acid-containing resin of ethylene / ethyl acrylate copolymer (composition: 66 /
34 wt%) 100 parts by weight of maleic anhydride 1.0
Parts by weight , 2,5-dimethyl-2,5-di (t-butylperoxy)
0.1 parts by weight of Hexin-3 (190 ° C, half-life 1 minute)
After mixing with a mixer, the resin temperature is 240
Ethylene produced by extruding at
A maleic anhydride graft polymer of a tyl acrylate copolymer . (3) Glycidyl group-containing flexible resin (hereinafter abbreviated as EnBAGMA) Ethylene / butyl acrylate / glycidyl acrylate copolymer composition: 60.2 / 34.5 / 5.3 wt% Component (C) (high softening point heat) (Plastic resin) (1) Polypropylene Made by Mitsui Petrochemical Co., Ltd .: Hypol J740 (2) Nylon Toray Industries Co., Ltd. Amilan: CM
(2) Evaluation of Performance The physical properties of the composition were measured and evaluated by the following methods. (2-1) 150 × 1 at a resin temperature of 180 ° C. in bending stiffness using a press molding machine.
A 50 × 2 mm press sheet was formed, a test piece was punched out of the square plate, and a test was performed according to ASTM D-747 to measure. (2-2) Melt flow rate (MFR) 190 ° C. or 2 according to ASTM D-1238
The measurement was performed at 30 ° C. and a load of 2160 g. (2-3) At a resin temperature of its own weight deformation of 180 ° C., 150 × 1
A 50 × 3 mm press sheet is formed, and from the square plate, 1
A test piece of 00 × 20 × 3 mm was punched out, one end of the test piece was fixed at a height of 10 cm, and the height of the other end was measured (h
₀ ). Next, the height of the other end after heating at a constant temperature for 2 hours is measured (h), and the amount of its own weight deformation is obtained from the following equation. By its own weight deformation amount = h ₀ -h (mm) [0025] (2-4) Hardness 180 ° C. of resin temperature, at a press molding machine, 0.99 × 1
A 50 × 2 mm press sheet is formed, a test piece is punched from the square plate, and the test piece is formed according to ASTM D-2240.
The eD hardness was measured. (2-5) Heat deformation test 150 ° C. by a press molding machine at a resin temperature of 180 ° C.
A 50 × 3 mm press sheet was formed, an empty can was placed on the square plate in an air oven adjusted to 110 ° C., and the surface of the square plate after standing for 10 minutes was observed. ◎ No trace at all ○ ~ ◎ Intermediate between ○ and ◎ Small traces (fine traces of cans) △ Fine traces (clear traces of cans) × Terrible traces [0027] [ Examples 1 to 5] Using a 30 mmφ twin-screw extruder (manufactured by Ikegai Iron Works Co., Ltd.), a mixture of the components (A) and (B) and polypropylene prepared at the compounding ratio shown in Table 2 was used. The mixture was melt-blended at an extrusion rate of 4.5 kg / hr, and the physical properties of the obtained resin composition were evaluated.
Table 2 shows the results. Example 6 A mixture of the components (A) and (B) and nylon prepared at the compounding ratios shown in Table 2 using a Labo Plastomill kneader manufactured by Toyo Seiki Co., Ltd. at a resin temperature of 25
Melt blending was performed at 0 ° C. for 10 minutes, and the physical properties of the obtained resin composition were evaluated. Table 2 shows the results. In each case, resin compositions excellent in both heat resistance and flexibility were obtained. [Comparative Examples 1 and 2] A sample in which the maleic acid-containing flexible resin used in the examples was not blended and two components consisting of only the terpolymer ionomer and polypropylene were prepared at the blending ratios shown in Table 3 was the same as in Example 1. Melt blend in the method of
The physical properties of the obtained resin composition were evaluated. Table 3 shows the results. In the case of the two-component composition, in the resin composition containing a large amount of polypropylene (Comparative Example 2), the heat resistance is improved by the polypropylene blend, but the flexibility is lost, while the decrease in flexibility is minimized. To keep
The effect of improving the heat resistance was not observed in the blending system in which the blending amount of polypropylene was reduced (Comparative Example 1). Comparative Example 3 A glycidyl group-containing flexible resin was blended in place of the maleic acid-containing flexible resin used in Example 1 at the blending ratio shown in Table 3, and melt-blended in the same manner as in Example 1. Although the obtained resin composition has greatly improved heat resistance as compared with the two-component blend system of polypropylene / terpolymer ionomer (Comparative Example 1), it does not reach the resin composition of the present invention. Table 3 shows the results. Comparative Example 4 A sample prepared by blending the maleic acid-containing resin used in Example 6 with two components of a terpolymer ionomer and nylon at the ratio shown in Table 3 was melted in the same manner as in Example 6. The physical properties of the blended composition obtained were evaluated, but the composition was poor in flexibility and no improvement in heat resistance was observed. Table 3 shows the results. [Table 2] [Table 3]

Claims (1)

(57) [Claim 1] An ethylene content of 50 to 90% by weight,
(Meth) acrylic acid content is 1 to 35% by weight, (meth)
Ethylene / (meth) acrylic acid / (meth) acrylate copolymer having an acrylate content of 5 to 40% by weight or its ionomer (A) 5 to 70 parts by weight, ethylene content of 40 to 90% by weight An unsaturated dicarboxylic acid, an anhydride thereof and a half ester thereof, the unsaturated dicarboxylic acid monomer content selected from the group consisting of 0.01 to
10% by weight, the content of (meth) acrylate is 9.
99 to 59.99% by weight of an ethylene / unsaturated dicarboxylic acid monomer / (meth) acrylate copolymer (B)
5 to 70 parts by weight and 20 to 60 parts by weight of a thermoplastic resin (C) having a melting point or a softening point of 110 ° C. or more [However, (A)
+ (B) + (C) in total of 100 parts by weight].