JPH01146942A - Modified olefin polymer composition - Google Patents

Abstract

PURPOSE:To provide the title composition excellent in heat resistance, mechanical strengths, etc., by mixing an olefin polymer graft-modified with a specified amount of an unsaturated carboxylic acid and having a specified MFR with a polyamide of a specified MFR. CONSTITUTION:40-60wt.% modified olefin polymer (A) (e.g., modified polypropylene) graft-modified with 0.001-0.04mg equivalent/g of an unsaturated carboxylic acid (derivative) (e.g., maleic anhydride) and having an MFR (at 230 deg.C under a load of 2.16kg) <=2g/10min is mixed with 60-40wt.% polyamide (B) (e.g., nylon) of an MFR (at 235 deg.C under a load of 1kg) >=20g/10min to produce a modified olefin polymer composition. This polymer composition is improved in, especially, the mechanical strengths of a weld part, so that it can be suitably used for automobile parts such as cooling fans or connectors.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention has good rigidity, heat resistance, water resistance, and surface gloss, especially during melt molding (for example, injection molding, extrusion molding, ultrasonic welding, vibration welding, etc.) The present invention relates to a modified olefin polymer composition having excellent mechanical strength in the weld portion.

Technical background of the invention and its problems Attempts have been made to improve various physical properties by adding and mixing polyamide or the like to olefin polymers such as polypropylene. However, since olefin polymers and polyamides have no compatibility at all, molded products obtained from their mixtures have extremely low mechanical strength, particularly the strength of the weld portion.

In order to solve these problems, it is sufficient to improve the compatibility between the olefin polymer and the polyamide. However, as a method for improving the compatibility between the olefin polymer such as polypropylene and the polyamide, for example, , A method of using modified polypropylene into which at least one of acid, ester amide, acid anhydride, and epoxy group has been introduced as the olefin polymer when mixing an olefin polymer such as polypropylene with polyamide (Tokuko Showa) 45-309
45) or a method of intervening maleic anhydride and modified polypropylene when blending crystalline polypropylene and polyamide (Kobunshi Kagaku 29.265 (19)
72)) etc. have been proposed. According to these methods, the compatibility between an olefin polymer such as polypropylene and polyamide is improved, and the physical properties of the film are improved, but the mechanical strength of the weld portion is not sufficiently improved.

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above, and aims to improve the compatibility between olefinic polymers such as polypropylene and polyamide, and improve mechanical strength, particularly in the weld area. The object of the present invention is to provide a modified olefin polymer composition that can give molded products with excellent mechanical strength.

The modified olefin polymer composition according to the present invention comprises N) a modified olefin polymer grafted with an unsaturated carboxylic acid or a derivative thereof (A>40 to 60% by weight), and (ii
In a composition consisting of 60 to 40% by weight of polyamide (B), the MFR of the modified olefin polymer (A) is 23
0'C12,16Nff) is 2.0 g/10 minutes or less, and the MFR of polyamide (B) (235°C, 1.0
Kg) is 20 g/10 minutes or more, and the amount of unsaturated carboxylic acid grafted in the modified olefin polymer (A) is in the range of 0.001 to 0.04 mg equivalent/g.

DETAILED DESCRIPTION OF THE INVENTION The modified olefin spinning wheel combined composition according to the present invention will be specifically described below.

Modified olefin polymer (A> In the modified olefin polymer composition according to the present invention, a graft-modified olefin polymer is used as one of the components. Examples of olefin polymers include homopolymers of α-olefins such as polyethylene, polypropylene, polybutene, poly-1-pentene, poly-1-octene, poly-1-decene, and poly-4-methyl-1-pentene; Copolymers of α-olefins such as copolymers of ethylene and other α-olefins, copolymers of propylene and other α-olefins, etc. are used.

In some cases, ethylene-propylene rubber, ethylene/α-olefin/polyene copolymer rubber, etc. may also be used. Among these, a propylene homopolymer which is crystalline and preferably has a density of 0.89 to 0.939/crd or 20 mol% of propylene and
The following block or random copolymers with α-olefins such as ethylene, 1-butene, and 4-methyl-1-benzone are preferred.

MFR of the modified olefin polymer (A>) used in the present invention
(230'C12,16Ky) is 2.0 g/10 minutes or less, preferably in the range of 0.3 to 1.0 y/10 minutes.

The modified olefin polymer (A> used in the present invention is
The olefin polymer as described above is graft-modified with a graft monomer selected from unsaturated carboxylic acids or derivatives thereof.

That is, the modified olefin polymer (Δ) may be a 7J reflex polymer that is entirely modified, or may be a mixture of a modified olefin polymer and an unmodified olefin polymer. In the present invention, when a mixture of a modified olefin polymer and an unmodified olefin polymer is used as the modified olefin polymer (A), it is sufficient that the MFR of the entire mixture falls within the above range, and the individual components That is, it is not necessarily necessary that the modified polypropylene and unmodified polypropylene fall within the above range.

Examples of unsaturated carboxylic acids or derivatives thereof used in graft modification of olefinic polymers include acrylic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid,
Citraconic acid, crotonic acid, isocrotonic acid, nadic acid (endocys-bicyclo(2,2,1)hept-5
-ene-2,3-dicarboxylic acid> or derivatives thereof, such as acid halides, amides, imides, anhydrides, esters, and the like. Specifically, maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate,
Examples include monomethyl maleate, dimethyl maleate, and glycidyl maleate. Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, especially maleic acid and Nazic! (2) or acid anhydrides thereof are preferred.

The grafting ratio of the graft monomer of the modified olefin polymer (A>) used in the present invention is 0.001 to 0.04 m3 equivalent, preferably 0.005 to 0.03 mg, per 1 g of the olefin polymer. Must be in the equivalent range.If the grafting monomer is less than the above range,
Poor compatibility between olefin polymer and polyamide,
This is undesirable because the tensile strength and appearance of the resulting composition are impaired, delamination occurs, and particularly the weld strength is reduced.On the other hand, if an olefin polymer with a grafting ratio exceeding the above range is used, the resulting composition This is not preferable because the weld strength is rather reduced.

The polyamide (B) used in the present invention includes hexamebulene diamine, decamethylene diamine, dodecamethylene diamine, 2,2,4- or 2,4,4-trimethylhexamethylene diamine, 1,3- or 1゜Aliphatic, alicyclic, aromatic diamines such as 4-bis(aminomethyl)cyclohexane, bis(p-aminocyclohexylmethane), m- or p-xylylenediamine, and adipic acid, speric acid, sebacin Polyamides obtained by condensation with acids, dicarboxylic acids such as cyclohexanedicarboxylic acid, prephthalic acid, and isophthalic acid, or polyamides obtained from lactams such as ε-caprolactam and ω-laurolactam, and copolymers made of these components. Examples include polyamides and mixtures of these polyamides.

Specifically, nylon 6, nylon 66, nylon 61
01 Nylon 9, Nylon 11, Nylon 12, Nylon 6/66, Nylon 66/610, Nylon 6/11
Examples include.

In the present invention, the MFR of this polyamide (235°C, 1.
ONg> is 20.0g/10 minutes or more, preferably 25~
50 g/10 minutes is important, and only by using a polyamide within this range can a composition with significantly high mechanical strength of the weld portion, which is the object of the present invention, be obtained.

In the modified olefin polymer composition according to the present invention, the modified olefin polymer <A> is contained in an amount of 40 to 60% by weight, preferably 40 to 55% by weight, and the polyamide (B) is 60-40%, preferably 55-40%
It is contained in an amount of 45% by weight. When the amount of the modified olefin polymer (A> is less than 40% by weight, the olefin polymer polymer phase cannot form a matrix in the resulting modified olefin polymer composition, resulting in a composition with low rigidity in practical use. If the modified olefin polymer (A>ffi exceeds 60% by weight), the resulting modified olefin polymer composition will have low heat-resistant rigidity and extremely poor gasoline resistance. Therefore, it is undesirable.

The modified olefin polymer composition according to the present invention comprising the modified olefin polymer (A) and polyamide (B) as described above has an MFR (235° C1'+, o
Kg> is 15-100g/l 0 min, preferably 20-100g/l
It is desirable that it be 50g/10 minutes.

Production method In order to obtain the modified olefin polymer composition of the present invention, the modified olefin polymer (A>) and polyamide (B) are mixed in the above range using various known methods such as Henschel mixer, ■-blender, ribbon blender, and tumbler. -,
After mixing with a blender or the like, a method of melt-kneading with a screw extruder, twin-screw extruder, kneader, Banbury mixer, etc., and then granulating or pulverizing the mixture can be adopted.

The modified olefin polymer composition according to the present invention may optionally contain a heat stabilizer, a weather stabilizer, an antistatic agent, a lubricant,
A slip agent, a nucleating agent, a flame retardant, a pigment, a dye, etc. may be added to the extent that the object of the present invention is not impaired.

Effects of the Invention In the modified olefin polymer composition according to the present invention, since the specific modified olefin polymer (A) and the specific polyamide (B) are used in a specific ratio, the mechanical strength of the weld portion is improved. A composition with a surprisingly high This is completely unexpected in the prior art. Moreover, since the composition has much less hygroscopicity than polyamide alone, there is little change in physical properties due to moisture absorption.
It also has advantages such as maintaining heat resistance and rigidity.

As described above, the modified olefin polymer composition according to the present invention has excellent heat-resistant rigidity and water resistance, and has improved mechanical strength in the weld area, so it can be used in fields where polyamides have been conventionally used, such as It is suitable for products with welded parts such as cooling fans, connectors, tuners for automobile parts, and electrical parts such as power tool housings, motor fans, connectors, motor covers, etc.

[Examples] Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

In addition, in the following examples, various characteristics were measured as follows.

Tensile properties: ASTM D 638 nit%
Base T: Measured.

MFR: Measured in accordance with ASTM D1238.

The test piece on the right side of the weld part was prepared as follows.

A tensile test piece (ASTM Toy Pe IV>) was prepared by injection molding using a mold that had gates at both ends and caused the resins to collide with each other at the center of the test piece to generate a weld.

Weld test piece forming conditions Forming machine 8 steel JC-150 Cylinder - Set temperature C1/C2/C3/Nozzle tip 230/240/250/250 ('C) Mold temperature
50'C Injection speed Medium speed injection pressure 1000/800=Primary/Secondary (KF
i/ci) Example 1 Polypropylene (hereinafter referred to as PP-1) with a VFR (230° C., 2.16Ks) of 0.5y/10 min (hereinafter referred to as PP-1) with a loss of 42% and anhydrous maleic with a [η1 of 1.66u/9] Modified polypropylene with acid graft ff 13.0% by weight (hereinafter referred to as modified 1) P>1. Modified polypropylene (MFR (230°C, 2.16Kg)) has an O weight% of 0.
5g/10 minutes, and the amount of unsaturated carboxylic acid is 0.01417! g hit/g) and VFR (2
After dry-blending nylon 6 (hereinafter referred to as Ny6-1) with a temperature of 11,0 Kg at 35°C for 35 s/10 minutes (hereinafter referred to as Ny6-1) with a tumble blender of 57 fflff1%,
Pellets were produced by granulation at 240° C. using a φ extruder. After drying this pellet, it was injection molded at 240° C. to prepare a test piece for tensile measurement having a welded portion.

The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that the quantitative ratios of PP-1, NV 6-1, and PP were changed as shown in Table 1.

A modified polypropylene consisting of the above PP-1 and modified PP has an MFR (230'C12,16) of 0.
59/10 minutes, and the amount of unsaturated carboxylic acid grafted is 0.029 m! I got 7 ♀/J.

The results are shown in Table 1.

Comparative Example 1 In Example 1, MFR=11 y instead of PP-1
/10 minute polypropylene (hereinafter referred to as PP-2)
and VFR=259/1 instead of NV6-1
The same procedure as in Example 1 was carried out except that 0 minute nylon 6 was used. In addition, the MFR of modified polypropylene consisting of the above PP-2 and modified PP (3> at 230'C12,16)
was 119/10 minutes, and the amount of unsaturated carboxylic acid was 0.014/i and 0.014/g.

The results are shown in Table 1.

Comparative Example 2 In Example 1, instead of PP-1, MFR=40g/
Except that 10 minute polypropylene (hereinafter referred to as PP-3) and Nylon 6 with VFR = 4.5 g/10 minutes (hereinafter referred to as NV 6-3) were used instead of Ny 6-1.
The same procedure as in Example 1 was carried out. In addition, the VFR (230°C
, 2.16 Ng> was 40 g/10 min, and the amount of unsaturated carboxylic acid grafted was 0.014 mg fA/g.

The results are shown in Table 1.

Table 1 Procedural Amendment ■, Indication of the case 1988 Patent Application No. 308,026-2, Name of the invention Modified olefin polymer composition 3, Person making the amendment ■ Relationship with the case Patent applicant name Title Mitsui Petrochemical Industries Co., Ltd. 4, Agent (zip code 141) N.M. Building 4, Higashigotanda-chome-25-4, Tokyo Parts Ward
[Telephone Tokyo (444) 3151] 8199 Patent Attorney Shun Suzuki - 6th Department -) 7, Contents of amendment (1) In line 11 of page 12 of the specification, r (AST
M Type IV)” is replaced with r (ASTM
Correct as D638 Type IV) J.

Claims (1)

[Claims] In a composition comprising 40 to 60% by weight of a modified olefin polymer (A) graft-modified with an unsaturated carboxylic acid or a derivative thereof and 60 to 40% by weight of polyamide (B), the modified olefin polymer (A) MFR (230℃
, 2.16Kg) is 2.0g/10min or less, and the MFR (235°C, 1.0Kg) of the polyamide (B) is 20g/10min or more, and the The grafting amount of unsaturated carboxylic acid is 0.0
A modified olefin polymer composition characterized in that the amount thereof is in the range of 0.01 to 0.04 mg equivalent/g.