JPS5880335A - Resin composition - Google Patents

Abstract

PURPOSE:A resin composition excellent in low-temperature impact resistance, comprising an ethylene/propylene random copolymer, an ethylene/propylene/ (diene) copolymer rubber and an ethylene/alpha-olefin linear copolymer having short- chain branches. CONSTITUTION:The titled composition is prepared from (A) an ethylene/propylene random copolymer, ethylene content 3-9wt%, stiffness >=10,000kg/cm<2>, MFI 0.1-40g/10min, (B) at least one rubber substance selected from the group consisting of an ethylene/propylene copolymer rubber and an ethylene/propylene/ diene terpolymer, and (C) an ethylene/12 C or lower alpha-olefin linear copolymer having short-chain branches, MFI 0.5-40g/10min, density 0.900-0.950g/cm<3>. The sum of component A and B in this composition is 1-99wt% and component A in the sum of components A and B is 99-50wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION Mark Object of the Invention The present invention relates to a resin composition. For more details Hl(A
l Ethylene propylene random copolymer, (B) (
At least one rubber-like material selected from the group consisting of 1) ethylene-propylene copolymer rubber and (2) ethylene-propylene-diene terpolymer copolymer rubber, and (Cl
The present invention relates to a resin composition comprising a linear copolymer of ethylene and an α-olefin having short chain branches, and its purpose is to provide a resin composition with excellent low-temperature impact resistance.

BACKGROUND OF THE INVENTION For some time, patented fin-based synthetic resins characterized by olefins such as ethylene-based polymers and propylene-based polymers and/or synthetic rubbers have been blended together, and the resulting compositions have been utilized in a wide variety of fields. There is. These compositions have some excellent physical properties such as low-temperature impact resistance, moldability, surface gloss of molded products, heat resistance, tensile strength, surface hardness, and flexibility, but overall they are Judging,
It cannot be said that the composition has satisfactory flexibility.

In addition, in recent years, olefin-based thermoplastic elastomers (T, P, E) have been developed as olefin-based soft resin compositions, but they are not only expensive but also have the problem of poor surface gloss of molded products. .

Furthermore, resin blends of inexpensive ethylene-propylene block copolymers and high-density polyethylene (HDPE) or ethylene-vinyl acetate copolymers (EV, A) have been proposed; The composition suffers from poor impact resistance at fairly low temperatures, such as A60°C.

■ Structure of the Invention Based on the above, the present inventors have conducted various searches to obtain a resin composition that is not only inexpensive but also has excellent low-temperature impact resistance. It has a weight rating of 3 to 9 and a stiffness (measured based on ASTM D'-747) of 10.
．． 000 kg/cnr2 or less, and the melt flow index (based on JISK-6758,
An ethylene/uropyrene random copolymer having a 1MFT (hereinafter referred to as 1MFT) of 01 to 40.9/10 minutes, measured at a temperature of 230°C and a load of 2.16 kg.
(hereinafter referred to as ``propylene copolymer''), (B) (1) ``Ethylene-propylene copolymer rubber'' (
Hereinafter referred to as EPRJ and (2) 1' ethylene.
"Propylene-diene ternary copolymer rubber" (hereinafter referred to as 1'-E
At least one rubber-like material selected from the group consisting of PDMJ) and (C1' melt index (JIS K-676
Measured based on temperature 190 °C and load 2.1
Measured under the condition of 6 kg, hereinafter referred to as "M,■,") is 0
．． 5 to 4o11/1o, and JIS K-6
Density measured based on 760 is 0.900-0.950
11/cm and the number of carbon atoms is at most 12.
A composition consisting of a linear copolymer having short chain branches with α-olefins (hereinafter referred to as "ethylene-based linear copolymer"), the random copolymer occupying in the composition The total sum of the polymer and the rubbery substance is 1 to 99% by weight, and the proportion of the random copolymer in the total of the random copolymer and the rubbery substance is 99 to 50% by weight. The inventors have discovered that a resin composition not only has excellent low-temperature impact resistance but can also be obtained at a relatively low cost, and has thus arrived at the present invention.

(2) Effects of the Invention The composition obtained by the present invention can not only be produced at a relatively low cost, but also has excellent physical properties as described below.

(1) Excellent impact resistance at low temperatures (-60°C).

(2) The surface of the molded product has good gloss and hardness.

(3) Excellent heat resistance and flexibility.

(4) Since moldability is good, molded products having complicated shapes can be manufactured.

(5) Low molding shrinkage and few sink marks. The appearance is also good.

(6) Excellent weather resistance.

The composition obtained by the present invention not only can be produced at a relatively low cost, but also has good physical properties as described above, and is expected to be used in a wide variety of fields. Typical uses are shown below.

(1) Automotive parts such as bumper faces, bumper corners, bumper sight shields and mudguard ducts; (2) Recesses in soft parts such as hoses, tubes and grips. Detailed Description of the Invention (A) Propylene copolymer used in the present invention The propylene copolymer produced is a random copolymer of ethylene and propylene. The content of ethylene in this propylene copolymer is 3 to 9% by weight.
It is preferably 4 to 9% by weight, particularly preferably 6 to 9% by weight. If the ethylene content is less than 3% by weight, the resulting composition will have poor flexibility. On the other hand, even if an attempt is made to produce a propylene copolymer containing more than 9% by weight, so-called 7-auring occurs during production, making it difficult to produce in a satisfactory state. Also, the stiffness is 10.
o 0. Okg 7cm2 or less tear, s, oo.

kg/cm2 or less, especially 5,0OOkf
/crn2 or less is preferable. Stiffness is 10.0
If it exceeds 0 ok/cm2, the flexibility of the resulting molded product will decrease. Furthermore, the MF of this propylene copolymer
I is 0.1 to 40.9/10 minutes, and 0. s~20.
9/10 minutes is preferred, particularly 1.0 to lOg/10 minutes. MFI of propylene copolymer is 0.19
If the heating time is less than 10 minutes, it will be difficult to mix the uniform composition, and the moldability of the composition will be poor. On the other hand, 401/
/ If the time exceeds 10 minutes, impact resistance, especially low temperature impact resistance -
inferior in sex.

(B) Rubber-like material The dome-like material used in the present invention is at least one rubber-like material selected from the group consisting of EPR and EPDM. EPR is a polymer obtained by copolymerizing ethylene and propylene. On the other hand, E
PDM has ethylene and propylene as its main components, and has a molecular weight of 1.4
-pentadiene, 1.5-, coxadiene and 3.3
- diolefins containing two double bonds at the end, such as dimethyl-1,5-hexadiene; Linear or branched diolefins or bicyclo[2,2,
A multicomponent copolymer rubber obtained by copolymerizing a small amount of a monomer having a double bond such as a cyclic diene hydrocarbon such as [l]-hebutene-2 (norbornene) and its derivatives (e.g. ethylidene norbornene). be. The weight ratio of one unit of ethylene monomer to one unit of propylene monomer in this EPR and EPDM is 20/80 to 8.
o/20 is preferred. Further, the copolymerization ratio of the monomer having double bonds in EPDM is at most 10% by weight. These rubbery materials are industrially produced and widely used in catalyst systems containing transition metal compounds and organometallic compounds (generally organoaluminum compounds) as main components.

These rubber-like materials preferably have a Mooney viscosity of 20 to 140, particularly preferably 30 to 120. Also, M, 1. (Measured according to ASTM D-1238, temperature 190"C1 load 2.16ky-)
, is generally 0. It is t~69/lo minutes.

-(C) Ethylene-based linear copolymer The 1,000-ethylene linear copolymer used in the present invention is a copolymer of ethylene and α-olefin. M and I of the ethylene-based linear copolymer are 0°'5 to 4 (1/1
0 minutes, preferably 1.0 to 30.9710 minutes, particularly preferably 4.0 to 201710 minutes. M of the ethylene-based linear copolymer, 1. is less than 0.5g/10 minutes,
Poor moldability (especially injection molding). On the other hand, 4011/10
If the density exceeds 100%, the impact resistance will be low, so the density of the linear ethylene copolymer is preferably 0.900-0.
950.9/tM3, 0.900-0.94
597 cm is desirable, especially 0.905 to 0.90 cm.
94o 97cm" is suitable. Furthermore, 0.910
~0925,! il/crn is optimal.

The density of this ethylene-based linear copolymer is 0.9001/
If it is less than 7 cm, the rigidity is not sufficient. On the other hand, 0,
If it exceeds 9501/cm3, it is unsuitable because it has high rigidity and lacks flexibility.

The α-olefin used in the production of the ethylene-based linear copolymer is an α-olefin having at most 12 carbon atoms, and typical examples include propylene, butene-1, hexene-1,4-methylpentene. -1 and octene-1. The copolymerization ratio of the α-olefin in this copolymer is usually 1.0 to 18% by weight.

What is short chain branching in this ethylene-based linear copolymer?
Refers to a branch that is sufficiently short compared to the main chain, for example, having less than 15 carbon atoms. On the other hand, a long chain branch means a branch having a length sufficiently comparable to that of the main chain, and having, for example, 15 or more carbon atoms.

These block copolymers and ethylene-based linear copolymers are ethylene and propylene or ethylene and the above α
-Olefins are referred to as Qi, Gura-(Ziegle)
r) Obtained by copolymerization using a catalyst or a Phillips catalyst. Ziegler's catalyst is a transition metal compound (e.g., a halogen-containing compound of titanium) or the transition metal compound on a carrier (e.g., a magnesium-containing compound, obtained by treating the magnesium-containing compound with an electron-donating organic compound). It is obtained by supporting a so-called carrier-supported solid catalyst component and an organoaluminum compound. Phillips catalyst is a carrier-supported catalyst obtained by supporting a chromium or molybdenum oxide or a compound of these oxides and zirconium on a carrier (for example, silica, silica-alumina), or a carrier-supported catalyst obtained by supporting the carrier-supported catalyst and an organic metal. It is obtained from a compound.

The above catalysts are merely typical Ziegler catalysts and Phillips catalysts, and other known catalysts may also be used. The method for producing this copolymer is also a well-known method.

(Dl Composition ratio (Content ratio) The composition ratio of the random copolymer and the rubber-like material in the composition obtained by the present invention is 1 as the sum of them.
-99% by weight, preferably 5-90% by weight, particularly preferably 30-80% by weight. If the total composition ratio of the random copolymer and the rubbery material to the composition is less than 1% by weight, the resulting composition will have poor heat resistance.

On the other hand, if it exceeds 99% by weight, low-temperature impact resistance will be low. Further, the proportion of the random copolymer in the total of the random copolymer and the rubbery material is 99 to 50% by weight,
90 to 60% by weight is desirable, particularly 85 to 70% by weight. If the proportion of the random copolymer in the total of the random copolymer and the rubber-like material exceeds 99% by weight, the impact resistance and flexibility at low temperatures will be insufficient, while if it is less than 50% by weight, There are problems such as stickiness and high cost.

(E) Mixing method In producing the composition of the present invention, it can be obtained by uniformly mixing the random copolymer, rubber-like material, and ethylene-based linear copolymer. In this case, all the ingredients may be mixed at the same time, or some of the ingredients may be mixed in advance, and the remaining ingredients may be mixed into the resulting mixture. In addition, depending on the purpose of use of the resulting composition, anti-aging agents commonly used in olefin polymers containing ethylene and/or propylene as main components,
Antioxidants, ultraviolet absorbers, plasticizers, fillers, lubricants,
Additives such as flame retardants, antistatic agents and colorants may be added to the copolymer to the extent that they do not substantially impair the aforementioned properties of the copolymer.

Mixing methods include tri-blending using a mixer such as a Henschel mixer, which is commonly used in the olefin resin industry, and melting using a mixer such as a Banbury mixer, kneader, roll mill, and screw extruder. There is a method of kneading. At this time, a more uniform composition can be obtained by triblending or melt-kneading in advance and further melt-kneading the resulting composition (mixture). Furthermore, among the ethylene-based linear copolymers and propylene-based copolymers that are components of the composition, or these and the above-mentioned additives,
A part of the components may be mixed to produce a masterbatch, and other composition components may be mixed with this masterbatch to produce the composition used to produce the shock absorber of the present invention. In these cases, the mixture is generally melt-kneaded and then molded into pellets, which are then subjected to the molding described later.

(F5 Molding method etc. In order to produce various molded products using the composition of the present invention,
Any molding method commonly used in the field of commonly used ethylene polymers and propylene polymers may be applied. Examples of the molding method include injection molding, blow molding, extrusion molding, and compression molding. In order to produce various molded products using these molding methods, it is necessary to carry out the process at a temperature higher than the melting point of the ethylene-based linear copolymer and propylene-based copolymer used, but these copolymers Of course, it must be carried out at a temperature lower than that at which thermal degradation occurs.

From the above, the molding temperature is 130 to 300°C.

The resin composition of the present invention has high flexibility, and conventionally used polyurethane (RIM molding), T, P
. It is suitable for the above-mentioned uses.

Physically, it has excellent heat resistance and low-temperature impact resistance, and has excellent heat resistance and low-temperature impact resistance.

Compared to E., it has a significantly higher gloss, no flow marks, etc., and has a good appearance. Furthermore, it is characterized by not being sticky like the blends described above and being inexpensive.

EXAMPLES EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be explained in more detail with reference to Examples below.

In addition, in the examples and comparative examples, the tensile test was conducted according to JIS
Measurements were made based on K-6301 at a tensile rate of 200 o+/min. Also, DuPont.

The impact strength was determined by pre-immersing the flat plate (sample) used in the measurement of the molding shrinkage rate described later in a dry ice-methyl alcohol solution (
-60°C), and then immediately measured in the following manner. Steel cylinder (thickness 2III11.dia.
Place the specimen on top of 46
A load weight of 1 kg (tip radius: 1/2 inch) was dropped onto the sample, and the presence or absence of cracking was observed. Furthermore, the surface hardness (Shore D) was measured based on ASTM D-2240. Moreover, the gloss was measured based on JIS Z-8741.

Furthermore, the thermal sagging property was determined by cutting out a specimen with a width of 17'2 inches, a length of 5 inches, and a thickness of 2.0 cm from the molded piece used to measure the molding shrinkage rate, fixing one end, and
The amount of deformation of the tip of the length of No. 111 was measured after 30 minutes at a temperature of 80°C. In addition, the molding shrinkage rate is determined by the injection molding machine (
Using Toshiba Machine Co., Ltd. (trade name: 1S-8OA), the cylinder temperature was 230°C, the injection pressure was 60 to 75 k
y/cm, secondary pressure is 50-55kf/crn2
, the thickness is 2m and 1l10x1 under the conditions of injection time 12 seconds, cooling time 20 seconds and mold temperature 50℃.
Fifty plates were injection molded. M direction and T at this time
The molding shrinkage rate in the direction was measured.

Examples 1 to 10, Comparative Examples 1 to 9 Ethylene content product (A) as propylene copolymer
''), an ethylene-based linear copolymer consisting of essentially linear random copolymerization of ethylene and butene-1 [density Q, 92o, li'/-3, M, I
, 7.0 g/l'O min, hereinafter referred to as "Polymer (B)J"
, a copolymer of essentially linear random copolymerization of ethylene and octene-1 [density 0916II/σ3, M
, I, 151! /10 minutes, hereinafter referred to as "polymer (C)" and a copolymer of essentially linear random copolymerization of ethylene and hexene-1 [density 0.917
g/Cm3, M, 1.10 g/10 min, hereinafter polymer (D
)"] and rubber-like materials such as ethylene-propylene-diene ternary copolymer rubber [diene ethylidene norbornene, ethylene content 70% by weight, Mj, 0.2,! i'/10 minutes, hereinafter referred to as polymer (E)] and ethylene-propylene copolymer rubber [ethylene content 72% by weight, M, I.

0.8 N/10 minutes, hereinafter referred to as "Polymer (F)"] were pre-triblended for 5 minutes using a Henschel mixer at the blending ratios shown in Table 1. Pellets were manufactured by kneading each of the obtained mixtures using an extruder (diameter: 65 mm) set at a temperature of 220°C.

A test piece was prepared from each of the obtained pellets using a 5-ounce injection molding machine. The MFI of each pellet and the physical properties of each test piece were measured. The results are shown in Table 2.

From the results of the above Examples and Comparative Examples, the composition obtained by the present invention not only has good impact resistance even at a fairly low temperature of -60°C, but also has excellent surface hardness and gloss. It is also clear that the heat resistance, flexibility, and tensile properties are good, and furthermore, because the molding shrinkage rate is small, there are few sink marks, and the appearance is good.

In contrast, compositions containing no rubbery substances (Comparative Examples 1 to
3) lacks impact resistance and flexibility at low temperatures, and if a large amount of rubbery material is added (Comparative Examples 4 to 9)
, which is unsuitable because it lowers heat resistance and causes stickiness.

Patent applicant: Showa Denko Co., Ltd. Agent: Patent Attorney Sei Kikuchi

Claims (1)

[Claims] (A) The ethylene content is 3 to 9% by weight, and the stiffness is 10. OOOkf/cm2 or less, and melt flow index is 0.1 to 40#/1
03+ At least one rubber-like material selected from the group consisting of (1) ethylene-propylene copolymer rubber and (2) ethylene-propylene-diene terpolymer rubber. and ((1 melt index is 0.5 to 40g゛/10
minute, and the density is 0900-0.950g/cm
ethylene which is and α- which has at most 12 carbon atoms
A composition consisting of a linear copolymer having short chain branching with an olefin, wherein the total of the random copolymer and the rubbery material in the composition is 1 to 99% by weight, and the random A resin composition characterized in that the proportion of the random copolymer in the total of the copolymer and the rubber-like material is 99 to 50% by weight.